CN100537147C - Polishing pad, manufacturing method thereof, and buffer layer for polishing pad - Google Patents

Abstract

A polishing pad capable of flattening materials requiring high surface flatness, such as silicon wafers for semiconductor devices, memory disks, magnetic disks, and optical lenses, at a stable and high polishing rate. The present invention provides a polishing pad that is easy to produce such as thin plate, surface processing of grooves, etc., has excellent thickness accuracy, high polishing speed, and can obtain a uniform polishing speed; and there is no quality deviation due to individual differences, and the processing pattern can be easily changed. Fine machining, a polishing pad that does not have burrs when forming unevenness; and can correspond to various materials to be ground, and can mix abrasive grains to an extremely high concentration, and even if the abrasive grains are dispersed, there are few scratches caused by the aggregation of abrasive grains abrasive pad. A polishing pad is formed in which the polishing layer is formed of a curable composition cured by energy rays, and the surface of the polishing layer has irregularities formed by photolithography. The grinding layer resin in which the abrasive grains are dispersed is a grinding pad of a resin having 20 to 1500 eq/ton ion groups.

Description

Polishing pad, manufacturing method thereof, and buffer layer for polishing pad

This application is a divisional application of the invention patent application with the application number 200510054379.5, the application date being November 28, 2001, and the invention name is grinding pad and its manufacturing method and buffer layer for grinding pad.

technical field

The present invention relates to a polishing pad which can be used as a polishing pad which is characterized in that it is easy to perform fine surface processing in industry, and can be used as a stable and high polishing speed for silicon wafers, memory disks, and magnetic disks used as semiconductor devices. Optical materials such as optical lenses and mirrors, glass plates, metals, and other materials that require a high degree of surface flatness are used as polishing pads for flattening processing. The polishing pad of the present invention is particularly suitable for use in a step of planarizing a silicon wafer and a device (multilayer substrate) on which an oxide layer, a metal layer, etc. are formed, before laminating and forming these layers.

The present invention also relates to the manufacturing method of the above-mentioned polishing pad and the buffer layer of the polishing pad.

Background technique

A typical example of a material requiring a high degree of surface flatness is a disk of single crystal silicon called a silicon wafer for manufacturing semiconductor integrated circuits (IC, LSI). Silicon wafers are required to be processed flat with high precision in each thin film manufacturing process in order to form reliable semiconductor junctions of various thin films used in the production of circuits such as ICs and LSIs.

Generally, a polishing pad is fixed to a rotatable support disk called a platen, and a semiconductor wafer is fixed to a disk called a polishing head capable of self-revolving motion. Through the rotational movement of both sides, a relative velocity is generated between the grinding plate and the grinding head, and fine particles (abrasive grains) such as silica or cerium oxide suspended in an alkaline solution or an acidic solution are dispersed. Polishing and planarization are performed while a solution (slurry) of the polishing material flows between the polishing pad and the wafer. At this time, when the polishing pad moves on the wafer surface, abrasive grains are pressed against the wafer surface at the point of contact. Therefore, through the sliding dynamic friction between the wafer surface and the abrasive grains, the processed surface is ground to reduce the level difference or surface roughness of the ground material. Such grinding processing is generally called CMP processing.

<(I) Polishing Pad>

As the pad used for the mirror surface polishing of the semiconductor wafer in the above-mentioned polishing process, a polyurethane foam type polishing pad, a polishing cloth type polishing pad impregnated with a polyurethane resin in a polyester nonwoven fabric, and two of these are known. A laminated polishing pad in which two pads are bonded together.

As such a polyurethane foam type polishing pad, a polyurethane foam sheet having a cavitation rate of about 30 to 35% is generally used. In addition, the technique of dispersing a polishing pad such as hollow microparticles or water-soluble polymer powder in a matrix resin such as polyurethane described in JP-A-8-500622 is also known.

In addition, among these polishing pads, for the purpose of improving the flow of the slurry and retaining the slurry, a polishing pad in which irregularities such as grooves and through holes are formed on the surface of the polishing layer is also known. As a known technique for forming concavities and convexities on the polishing layer of a polishing pad, in JP-A-11-48129, JP-11-58219 or JP-11-70462, etc., it is disclosed that an operator uses a knife, a carving knife, a diamond rotary The technique performed by appliances such as plates.

The above-mentioned known polyurethane foam sheet with a cavitation rate of about 30 to 35% has excellent local flattening ability, but its compressibility is relatively small at about 0.5 to 1.0%. Uniform pressure is applied across the entire wafer face. Therefore, usually, a soft buffer layer is separately provided on the back surface of the polyurethane foam sheet, and the grinding process is performed.

A polyurethane foam type polishing pad or a polishing pad described in Japanese Patent Application Publication No. 8-500622 constitutes a polishing layer, and when the polishing surface is worn away, the new surface constitutes the polishing layer. That is, since the entire polishing pad has uniform elastic characteristics, there are problems in the polishing speed or the uniformity or step characteristics of the object to be polished. That is, when there is a difference in hardness between the raw materials constituting the surface of the object to be ground, the soft side will be shaved more, and the flatness cannot be obtained from a microscopic point of view. In addition, when polishing, it is necessary to provide a buffer layer impregnated with polyurethane resin in a polyester non-woven fabric on the back side, that is, on the side where the platen is installed. In addition to the polishing pad manufacturing process, there must be a process of bonding the buffer layer. Therefore, it is difficult to meet the demand for cost reduction.

During the grinding process, these grinding pads accumulate abrasive grains and chips in the slurry in the holes on the surface of the grinding layer, which reduces the grinding speed. The finishing process of grinding the surface to create a new surface, because the holes in the polishing pad are not uniformly dispersed, the size and shape of the holes are inconsistent, etc., even if the finishing process is performed, the renewed surface will not become the same surface, so there is Problems with different grinding characteristics. In addition, grinding cannot be performed in the correction process, which causes a decrease in production efficiency. In addition, there is a problem that the pad is consumed in addition to polishing the object to be polished when the pad is shaved in the correcting process.

In addition, grooves, concentric circles, holes, and other roughness processing are performed on the polishing surface in order to make the slurry used in polishing flow and hold it. As this processing method, methods such as cutting with a carving knife or a cutting machine, and pressing with a designated metal mold are used. The first two methods exist, and it is difficult to prevent quality deviations caused by individual differences among operators; it is difficult to change Processing patterns; there are limitations in micromachining; burrs are generated during cutting; scratches are generated on the grinding surface of the material to be ground, and the cost of making metal molds increases in the latter method; the physical properties of the processing peripheral part change due to pressure, etc. The problem.

As a method for solving the above-mentioned latter problem, it is proposed to use a photosensitive composition described in WO9830356, to cure the irradiated part with ultraviolet rays or laser light to remove the unexposed part, to apply a liquid photosensitive resin on the support, and to use Polished surface processing by photolithography.

When coating with the above-mentioned liquid photosensitive resin, if a spacer with a certain thickness is to be produced, the liquid resin spreads after a certain period of time, and there is a problem in thickness accuracy. In order to improve this problem, if a pad is introduced into production, it will lead to a decrease in efficiency. In addition, since it is in a liquid state before exposure, product management (temperature control, etc.) before exposure and solidification is difficult, and product storage is also difficult, which is a factor that reduces work efficiency. In addition, the problem of periodically introducing dressing steps during the grinding process cannot be solved.

Contents of the invention

It is an object of the present invention to provide a polishing pad which is easy to produce such as thinning, surface processing of grooves, etc., has excellent thickness accuracy, has a high polishing speed, and can obtain a uniform polishing speed.

In addition, in the laminated polishing pad with laminated buffer layers, in order to make the difference in the elastic characteristics between the polishing layer and improve the polishing characteristics, as described in JP-A No. 11-48131, the processing of the segmented intermediate layer is carried out. At this time, the same problem as above also exists. Thus, in polishing pads, in order to improve the polishing properties, various roughness processes are performed on the polishing layer or other layers, but none of the above-mentioned problems can be solved.

Another object of the present invention is to solve the problems described above, to provide an inhomogeneity in quality without individual differences, and to easily change the processing pattern, to perform fine processing, and to correspond to various materials to be polished, and A polishing pad free from burrs when forming unevenness and a method for producing the same.

Still another object of the present invention is to provide a polishing pad that has a high polishing speed, excellent uniformity and step characteristics of the object to be polished, and does not require a buffer layer on the mounting surface of the platen.

The above-mentioned foam type polishing pad, because it is a pad with low elastic modulus and softer, as shown in Figure 6, during the polishing process, the polishing layer 31 itself will become deflected with the state of the circuit diagram 32 in the semiconductor wafer, and the pattern 33 will be deformed. The insulating film 34 between them is excessively polished, and there is a problem in the planarization property of the object to be polished from a microscopic point of view. In addition, foam-type polishing pads have limitations in improving the modulus of elasticity of the polishing layer, and there are limitations in improving flattening properties.

Conventionally, as physical properties of the polishing layer, polishing pads having improved elastic modulus include the following. ① A polishing pad whose hydraulic modulus is 250 psi for a compressive force of 1 psi when a compressive force of 4 to 20 psi is applied to the abrasive layer (JP-A-6-21028). ② Use a polishing pad with a polishing layer having a tensile elastic modulus of 1 MPa to 500 MPa (JP-A-2000-202763). ③ A polishing pad with a bending elastic rate of 3500-4000kg/cm ² (JP-A-2001-105300). However, although the polishing pads described above have improved planarization properties to some extent, it cannot be said that sufficient planarization properties have been obtained.

Another object of the present invention is to provide a polishing pad excellent in flattening properties of an object to be polished.

Conventional polishing pads using a polyurethane sheet and having a cushion layer have the following problems.

(1) As a buffer layer, a nonwoven fabric impregnated with a resin having continuous voids is widely used, but there are problems such as dispersion of the nonwoven fabric and changes in compression characteristics due to water immersion of the slurry solution.

(2) Although foamable polyurethane foams having independent cavities have been used, it is difficult to stabilize the foamed state during production, and the residual deformation to repeated loads is large due to the cavities.

Still another object of the present invention is to provide a buffer layer that has less dispersion in compressive properties, less change in compressive properties due to immersion of slurry, and can reduce the influence of residual deformation of the abrasive layer on repeated loads.

<(II) Polishing pad without slurry>

The following techniques are also known as polishing pads used in CMP.

①The elastic polyurethane layer is laminated with a synthetic leather layer as an abrasive layer (US Patent No. 3,504,457).

② It is composed of non-woven fabric impregnated with polyurethane on the foamed polyurethane layer (JP-A-6-21028)

③ It is characterized in that a grinding surface is provided, a rigid part of selected thickness and rigidity is provided next to said grinding surface, and a resilient part is provided next to said rigid part in order to impart substantially the same force to said rigid part. member, the rigid member and the elastic member impart an elastic bending force to the grinding surface to induce a controlled curvature in the grinding surface, and the bending is suitable for the overall shape of the surface of the workpiece and for the workpiece The local shape of the surface maintains controlled rigidity (JP-A-06-077185).

④ It is characterized in that it has a surface layer A with a large longitudinal elastic coefficient EA and a lower layer B with a small longitudinal elastic coefficient EB, and the grinding of the middle layer M with a larger longitudinal elastic coefficient than the B layer at least is arranged between the two layers A and B Cloth (Kaiping No. 11-156724 bulletin).

⑤ A pad consisting of an abrasive layer, an intermediate layer with higher elasticity than the abrasive layer, and a soft bottom layer, and the intermediate layer is divided (JP-A-11-48131).

The various polishing pads described in the above ① to ⑤ have the following problems.

①In this method, regarding the overall uniformity, the elastic polyurethane layer plays the role of uniformizing the load applied to the wafer. Since soft synthetic leather is used on the outermost grinding layer, there are no problems such as scratches, but there are Problems with poor planarization characteristics in minute areas.

② In the lamination of polyurethane and nonwoven fabric, the nonwoven fabric plays the same role as the elastic polyurethane layer of ① above, and uniformity is obtained. In addition, since the polishing layer also has a hard foamed polyurethane layer, it is superior to synthetic leather in flattening properties, but it does not meet the level of improvement in flattening properties required for micro-areas in recent years or the level required for polishing metal films. . In addition, attempts to improve planarization characteristics by further increasing the hardness of the hard polyurethane layer were not practical because many scratches were generated in this case.

③ The abrasive layer, rigid layer, and elastic layer structure is such that the abrasive layer on the surface layer has an appropriate hardness so as not to cause scratches, and the planarization characteristics that deteriorate without increasing the hardness are improved in the rigid layer of the second layer. This will solve the problem of the above method ②, but in this case, the thickness of the abrasive layer is specified to be 0.003 inches or less, and when this thickness is used in practice, the abrasive layer is chipped off, which has the disadvantage of shortening the product life.

④The basic idea of this method is the same as the above method ③, and the elastic modulus range of each layer is limited to obtain a more efficient range. However, in this method, there are not many ways to realize it, and it is difficult to manufacture a polishing pad.

⑤ The basic idea of this method is also the same as the above method ③. In order to further improve the uniformity in the wafer plane, the intermediate rigid layer is divided into predetermined sizes. However, this dividing step is costly, and an inexpensive polishing pad cannot be supplied.

In addition, the polishing pads of ① to ⑤ need to flow an expensive slurry during the polishing process, which involves an increase in manufacturing cost. Therefore, a so-called fixed abrasive type polishing pad containing abrasive grains in a polishing layer has been developed. Such a fixed-abrasive polishing pad does not need to flow expensive slurry in the polishing process like a free-grain polishing pad.

As a fixed abrasive type polishing pad, for example, a polishing pad having a structure in which cerium oxide fine particles are mixed with foamed polyurethane resin is disclosed (JP-A-2000-354950 and JP-A-2000-354950). However, this polishing pad has a problem in that the concentration of abrasive grains in the polishing layer is too high, and the slurry has to be used together in order to increase the polishing speed.

In addition, ⑦, an abrasive disc having a structure in which abrasive grains are dispersed in a binder solution dissolved in a solvent and coated on a film is disclosed (JP-A-2000-190235). However, in this polishing pad, resin and abrasive grains are only mixed together in a solvent, so there is a problem that aggregation of fine grains occurs and scratches are likely to be generated.

In addition, it discloses ⑧ granulated fine particles of 1 to 30 μm in which primary abrasive grains of 0.5 μm or less are agglomerated twice as an abrasive on a base material with a binder resin so as not to contain a binder resin. A polishing pad with such a structure (JP-A-2000-237962). However, this polishing pad positively agglomerates the abrasive grains because the abrasive grains are effectively added to the resin, but there is a problem that the aggregates are likely to cause scratches.

In addition, disclose a kind of ⑨ the abrasive grain that the average particle diameter of solid below 50 μ m is mixed with the abrasive grain of maximum particle diameter at normal temperature, then fill it into the grinding pad of pressurization heating forming in the metal mold (patent open 2000-190232 Bulletin). However, this polishing pad has the problem that it is difficult to mix the fat powder and abrasive powder uniformly at the initial stage, and if the concentration of abrasive grains in the polishing pad is increased, the resin as a binder is reduced and molded.

As explained above, the current situation is that there is no fixed abrasive pad to meet the requirements.

Another object of the present invention is to provide a polishing pad suitable for use as a semiconductor wafer polishing pad in the process of forming a fine pattern on a semiconductor wafer and flattening the micro unevenness of the pattern. A slurry-free polishing pad with good polishing properties and less scratches.

Another object of the present invention is to provide a kind of adaptable non-slurry, which can mix the abrasive grains into A pad for polishing a semiconductor wafer with an extremely high concentration and with little scratches caused by agglomeration of abrasive grains even though the abrasive grains are dispersed at a high concentration.

<(I) Polishing Pad>

The present invention is a polishing pad having a polishing layer, wherein the polishing layer is formed using a curable composition cured by energy rays, and the polishing layer has unevenness formed on the surface by photolithography.

The above-mentioned polishing pad is easy to produce such as thinning and surface processing such as grooves, has excellent thickness accuracy, and has a high polishing speed and can obtain a uniform polishing speed.

The abrasive layer preferably has a static friction coefficient of 1.49 or less and a dynamic friction coefficient of 1.27 or less between glasses under a load of 4400 gf.

In the polishing pad, the curable composition preferably contains a solid polymer compound.

In the above-mentioned polishing pad, the polishing layer may be directly used as a polishing pad, or a buffer layer may be laminated on the back side (the opposite side of the polishing surface) as a polishing pad.

In the polishing pad having a polishing layer, it is preferable that the polishing layer has no voids and has a storage modulus of 200 MPa or more, and the storage modulus of the buffer layer is lower than that of the polishing layer.

Conventionally, the elastic modulus of the polishing layer is the same as the above, and is an elastic modulus measured under arbitrary static conditions such as hydraulic modulus, tensile elastic modulus, and bending elastic modulus. However, during actual polishing, the semiconductor wafer as the object to be polished and the polishing pad rotate, and the polishing pad is repeatedly pressed and released periodically. Therefore, in the present invention, the difference in the amount of deformation of the surface of the polishing layer of the polishing pad is studied focusing on the storage elastic modulus which is considered to correspond to the elastic modulus under dynamic conditions. As a result, it has been found that by using a material with a high storage modulus of elasticity than the conventional polishing layer, that is, a material with a high storage modulus of elasticity of more than 200 Mpa, the problems caused by the conventional low storage modulus of the polishing layer polishing pad can be solved. , The problem concerning the planarization characteristic of the object to be polished.

The storage elastic modulus in the present invention is a value corresponding to the elastic term of dynamic viscoelasticity, and represents the rigidity of the material when dynamic vibration or deformation is applied. Such a pad with a high storage modulus, as shown in FIG. 5 , has a small amount of deformation of the polishing pad 31 against periodic deformation, and the flatness of the insulating film 34 between the patterns 33 of the circuit pattern 32 in the semiconductor wafer is good.

The storage elastic modulus of the abrasive layer is ideal above 2000Mpa, and the upper limit of the storage elastic modulus of the abrasive layer is not particularly limited, but if the storage elastic modulus is too high, it is easy to produce scratches (scratches) on the semiconductor wafer, so storage The modulus of elasticity is preferably 2 GPa or less, more preferably 1.5 GPa or less, particularly preferably 1 GPa or less. It is particularly desirable that the storage elastic modulus is 200Mpa-2Gpa, and more preferably 200Mpa-1Gpa. In addition, it is desirable that the polishing layer is a layer without voids. In order to make the storage elastic modulus of the polishing layer 200 MPa or more, it is desirable to form the polishing layer with a layer containing no voids such as a foam.

It is desirable to have a buffer layer having a storage elastic modulus lower than that of the abrasive layer, in addition to the abrasive layer having a storage elastic modulus of 200 MPa or more. When the abrasive layer has a high storage elastic modulus, although the bending and warpage of the object to be polished as a whole becomes high, by providing a buffer layer, the following property between the highly rigid abrasive layer and the object to be polished becomes good. Eliminates undulations and bending of the entire object to be polished. Therefore, even if a polishing layer having a high storage elastic modulus is used, the uniformity (flattening property) of the polished surface of the object to be polished will not be impaired. The storage elastic modulus of the buffer layer is not particularly limited as long as it is lower than the storage elastic modulus of the abrasive layer. It is preferably about 0.1 to 100 MPa, more preferably 0.1 to 50 MPa, and particularly preferably 0.1 to 30 MPa. good.

In the polishing pad of the present invention, it is desirable that the polishing layer is composed of a polishing surface layer and a back layer, the back layer is formed using a curable composition cured by energy rays, and the back layer is formed on the surface It has unevenness formed by photolithography.

The polishing pad having the above-mentioned structure has the following effects: that is, there is no unevenness in quality caused by individual differences, the processing pattern can be easily changed, fine processing is possible, and it can be adapted to various materials to be polished, and no unevenness occurs when forming unevenness. Raw edges.

In the above polishing pad, more preferably, the back layer is formed using a curable composition cured by energy rays, and the back layer has unevenness formed by photolithography.

The pressure on the polishing surface can be relieved without additionally laminating a buffer layer, and it has the function of improving the polishing characteristics. In addition, since the step of laminating the cushion layer is not required, the cost is low, and the polishing pad has a cushion layer that is strongly bonded to the polishing layer and integrated therewith.

In the polishing pad of the present invention, the polishing layer is composed of a polishing surface layer and a back layer, the hardness of the polishing surface layer is higher than that of the back layer, and the difference in hardness is 3 or more in Shore D hardness.

With such a configuration, it is possible to obtain a polishing pad having a high polishing speed, excellent uniformity and step characteristics of the object to be polished, and no need to attach a buffer layer made of a different material to the platen mounting surface. That is, by forming a back layer with low hardness on the polishing pad itself from the surface of the polishing layer toward the mounting surface of the platen, it becomes unnecessary to provide a buffer layer between the polishing pad and the platen. When the difference in hardness is less than 3, the polishing pad must be laminated with a cushion layer formed of another material similar to conventional ones.

The back layer may be formed such that the hardness decreases continuously from the abrasive layer to the plate mounting surface side, or may be a multilayer structure in which the hardness of the surface portion of the back layer on the plate mounting surface side is higher than that of the middle portion, or may be It is a two-layer structure in which the hardness of the surface part and the middle part of the back layer are the same, that is, the back layer forms a uniform hardness. The difference in hardness is the difference between the lowest hardness parts of the back layer. In the case of a multilayer structure, the hardness of the polishing surface and the surface of the back layer of the polishing pad may be approximately the same, and in this case, it is not necessary to distinguish the front and back of the polishing pad, and they may be used as the polishing surface. In addition, when the hardness of the outermost layer and the outermost layer are approximately equal and the hardness of the intermediate layer is lower than these, the difference in hardness is the difference in hardness between the outermost layer or the outermost layer and the intermediate layer.

The above-mentioned polishing pad, the polishing layer and the back layer are formed by loading at least one of energy rays and heat on a sheet formed of a curable composition to form the hardness difference, because it is possible to easily form a surface having a predetermined hardness difference. Abrasive pads, so ideal.

Loading refers to heating or irradiating energy rays so that unreacted curable composition sheets form predetermined hardness differences for each part and are cured. The formation of hardness difference is carried out by controlling the load. The control of the load is carried out by controlling the temperature, time, etc. during heating; in the case of energy rays, it is through the control of irradiation conditions such as the intensity of the energy rays and the irradiation time or through the permeability of the curable composition. , photoinitiator and other components or the adjustment of the amount of addition.

In the polishing pad of the present invention, it is desirable that the polishing layer and the back layer are continuously integrally formed using the same curable composition.

Therefore, the polishing pad can be manufactured more simply, and the polishing layer and the buffer layer are integrated.

The compressibility of the polishing layer of the polishing pad is preferably 0.5% or more in consideration of cushioning properties. More preferably, it is 1.5% or more. The compression recovery rate of the polished layer after processing is preferably 50% or more in consideration of the cushioning properties of the polished layer.

In order to increase the elastic modulus of the abrasive layer, foaming may be performed by mechanical foaming or chemical foaming.

Ideally, the unevenness formed on the surface of the polishing layer is a groove through which the slurry used during polishing flows.

Ideally, the unevenness formed on the surface of the polishing layer is a groove for storing slurry used during polishing.

The polishing pad of the present invention is preferably used when the object to be polished is a semiconductor wafer or a glass substrate for precision equipment.

The present invention is a method for producing a polishing pad having a polishing layer, characterized in that the polishing layer is produced by the following photolithography method.

(1) A sheet-forming step of forming a sheet-shaped molded article from a curable composition containing at least an initiator and an energy-ray-reactive compound and cured by energy rays;

(2) an exposure step of changing the solubility of the thin plate-shaped molded body to a solvent by irradiating the thin plate-shaped molded body with energy rays to induce modification;

(3) A developing step of forming a pattern of concavo-convex portions on at least one surface of the sheet-shaped molded article irradiated with energy rays by removing part of the curable composition with a solvent.

The manufacturing method is photolithography, by which it is possible to manufacture, there is no unevenness in quality caused by individual differences, it is easy to change the processing pattern, it can be microfabricated, it can be adapted to various materials to be ground, and A polishing pad that does not generate burrs when forming unevenness.

The abrasive layer and the back layer are continuously integrally formed using a curable resin composition cured by energy rays, and are characterized in that: a thinning step of thinning the curable resin composition into a thin plate; An exposure step in which the mask material is irradiated with energy rays; and a development step in which the uncured curable composition is dissolved and removed to form unevenness.

According to the method having the above configuration, the unevenness on the surface of the polishing layer and the back layer having the cushioning portion can be produced in one step, and a low-cost polishing pad can be obtained.

The step of exposing the polishing layer and the step of exposing the back layer may be performed independently or simultaneously from both sides.

The grinding pad is equipped with a grinding layer and a back layer formed continuously, the hardness of the grinding layer is higher than the hardness of the back layer, and the hardness difference is 3 or more in the production of a grinding pad with Shore hardness, ideal The difference in hardness is formed by loading at least one of energy rays and heat on the thin plate-shaped molded body of the curable composition.

The polishing pad of the present invention may be used alone without a cushion layer, or may be laminated with a film, nonwoven fabric, woven fabric, etc. having different compressive properties from the polishing layer.

In addition, the present invention is a polishing pad comprising at least a polishing layer and a cushioning layer, characterized in that the polishing layer has no voids and has a storage modulus of 200 MPa or more, and the storage modulus of the cushioning layer is lower than that of the polishing layer.

In the above-mentioned polishing pad, grooves through which the slurry used during polishing are formed on the surface of the polishing layer are ideal. In addition, in the polishing pad, a groove for storing a slurry used in polishing is formed on the surface of the polishing layer, which is an ideal form. As the object to be polished of the polishing pad, a semiconductor wafer or a glass substrate for precision equipment may, for example, be desirable.

Another invention of the present application is a polishing pad comprising a polishing layer and a back layer, wherein the hardness of the polishing layer is higher than that of the back layer, and the difference in hardness is 3 or more in Shore D hardness.

In the polishing pad, it is desirable that grooves for flowing the slurry used for polishing are formed on the surface of the polishing layer.

In such a polishing pad, it is desirable that grooves for storing slurry used during polishing are formed on the surface of the polishing layer.

In the polishing pad, the object to be polished is preferably a semiconductor wafer or a glass substrate for precision equipment.

<(I) Cushion layer for polishing pad>

The cushion layer for a polishing pad of the present invention is a cushion layer for a polishing pad composed of a polishing layer and a cushion layer, and is characterized in that the compression recovery rate is 90% or more.

The buffer layer has less variation in compressibility, less change in compressibility due to immersion of the slurry, and can reduce the influence of residual deformation due to repeated loads on the polishing layer.

The cushion layer for polishing pads preferably contains a compound having rubber elasticity.

In addition, it is desirable to roughen the surface of the cushion layer for the polishing pad (the side to which the platen is bonded).

The surface area of the plate can be reduced by embossing the side of the plate to which it is to be bonded, such as grooves or protrusions. Thereby, the applied stress increases, the amount of compressive deformation is increased, and the compressibility can be increased.

The unevenness is preferably a groove structure or a network structure.

On the polishing surface side of the pad, if the Shore hardness is less than 50, the hardness is too low, and if the compressibility is 2.0% or more, the flattening accuracy may be lowered. When the compression recovery rate is less than 50%, compaction may be caused, which is not preferable.

In addition, by increasing the rigidity of the polished surface side, the flattening accuracy is improved, but the in-plane uniformity is lowered. Therefore, it is required to provide a buffer layer to increase the compressibility and compression recovery rate of the entire gasket.

The cushion layer for polishing pads of the present invention preferably has a compression recovery rate of 90% or more.

<(II) Polishing pad without slurry>

The slurry-free polishing pad of the present invention is as follows.

A polishing pad having a polishing layer in which abrasive grains are dispersed in a resin, wherein the resin is a resin containing ionic groups in a range of 20 to 1500 eq/ton. The resin forming the polishing layer of the above-mentioned polishing pad of the present invention has an ion group content of 20 to 1500eq/ton, and can contain abrasive grains in a stable dispersed state for composite formation. Scratches caused by agglomeration of abrasive particles. In addition, the ionic group of the resin has water solubility or water dispersibility, and the affinity between the ground object and the ground object is improved by the water supplied in the grinding process, so that the grinding speed is increased, and the grinding process with excellent flatness and uniformity is shown. characteristic. From this point of view, the ionic group contained in the resin is preferably 20 eq/ton or more, more preferably 100 eq/ton or more, and particularly preferably 200 eq/ton or more. In addition, if there are too many ionic groups, the water solubility or water dispersibility becomes too strong, so the ionic groups that the resin has are preferably 1500 eq/ton or less, more preferably 1200 eq/ton or less, especially The ideal is below 1100eq/ton.

In the polishing pad, the resin forming the polishing layer is preferably polyester resin, and the ratio of aromatic dicarboxylic acid is preferably 40 mol % or more in the total carboxylic acid components constituting the polyester resin.

The resin forming the polishing layer is not particularly limited and various resins can be used, but polyester resin is preferable because it can easily introduce ionic groups. In addition, considering the abrasiveness of the surface of the abrasive layer, the glass transition temperature of the resin forming the abrasive layer is preferably 10°C or higher, more preferably 20 to 90°C. For example, by setting the ratio of the aromatic dicarboxylic acid in the total carboxylic acid components constituting the polyester resin to 40 mol % or more, the glass transition temperature can be made within the above range. More preferably, the moisture content of the aromatic dicarboxylic acid is 60 mol % or more.

In addition, the polishing pad of the present invention is a polishing pad having a polishing layer in which abrasive grains are dispersed in a resin, wherein the main chain of the resin contains 60 mol% or more of aromatic compounds in the total carboxylic acid components. It is a polyester of a family dicarboxylic acid, and the side chain of the resin is a polymer of a radically polymerizable monomer containing a hydrophilic functional group.

In addition, the polishing pad of the present invention is a polishing pad having a polishing layer in which abrasive grains are dispersed in a resin, and is characterized in that the main chain of the resin is composed of aromatic compounds containing 60 mol% or more of the total carboxylic acid components. Polyester polyurethane having a polyester of a family dicarboxylic acid as a main component, and the side chain of the resin is a polymer of a radically polymerizable monomer containing a hydrophilic functional group.

In the above-mentioned polishing pad, it is preferable that the resin forming the polishing layer has a specific gravity in the range of 1.05 to 1.35 and a glass transition temperature of 10° C. or higher.

The specific gravity of the resin forming the polishing layer is ideally in the range of 1.05 to 1.35. When the glass transition temperature is 10° C. or higher, when the polishing layer is produced, stickiness is generated on the polishing surface and polishing is performed well, so it is ideal.

In the polishing pad, the resin forming the polishing layer is preferably a mixture of a resin having a glass transition temperature of 60° C. or higher and a resin of 30° C. or lower.

The resin for dispersing the abrasive grains used in the present invention preferably has a structure in which two or more resins having a glass transition temperature of 60°C or higher and resins of 30°C or lower are mixed. Only resins with a glass transition temperature of 60° C. or higher may cause shrinkage of the coating film during coating and drying, and the coating film may not withstand the stress, causing wrinkles on the surface. In addition, if only a resin with a glass transition temperature of 30° C. or less is used for coating, the coating film surface is good, but it becomes a sticky surface, and the frictional resistance during polishing significantly increases, making stable polishing impossible. Therefore, it is necessary to mix two or more types of resins having different glass transition temperatures and to search for a balance thereof.

The glass transition temperature of the resin is desirably above 50°C, and the other is desirably below 20°C. If only a resin having a glass transition temperature of 50° C. or higher is used to form the abrasive layer, cracks will occur on the coated surface during drying, and a good coating film cannot be obtained.

In the polishing pad, the abrasive grains preferably have an average particle diameter of 5 to 1000 nm.

The abrasive grains are ideally microparticle abrasive grains with an average particle diameter of 5 to 1000 nm. If the average particle diameter of the abrasive grains becomes smaller, the dispersibility to the resin having the ionic group becomes poor, and it is easy to make it difficult to mix, so it is desirable that the average particle diameter of the abrasive grains be 5 nm or more, more preferably 10 nm or more, particularly preferably 20 nm or more. In addition, when grinding with an abrasive layer containing abrasive grains with a large average particle diameter, it may cause great damage to the object to be ground, so it is desirable that the average particle diameter of the abrasive grains be below 1000nm, more preferably 500nm Below, particularly preferably below 100 nm.

In the polishing pad, the abrasive grains are preferably at least one selected from the group consisting of silicon oxide, cerium oxide, aluminum oxide, zirconia, ferrous oxide, chromium oxide, and diamond.

In the polishing pad, the content of the abrasive grains in the polishing layer is desirably 20 to 95% by weight.

Because if the content of the abrasive grain contained in the grinding layer becomes less, sufficient grinding speed cannot be obtained, so in order to increase the grinding speed, it is desirable that the content of the abrasive grain is more than 20% by weight, more preferably more than 40% by weight, Especially preferably, it is 60 weight% or more. In addition, if the content of abrasive grains increases, the formability of the abrasive layer may be impaired, so the content of abrasive grains is preferably 95% by weight or less, more preferably 90% by weight or less, and particularly preferably 85% by weight. %the following.

In the polishing pad, it is desirable to have air cells in the polishing layer. In addition, the average particle diameter of the bubbles is preferably 10 to 100 μm.

A polishing pad with air bubbles in the polishing layer can achieve a more stable high polishing speed. The bubble diameter (average diameter) is not particularly limited, but in order to obtain a stable polishing rate, the bubble diameter is preferably 10 μm or more, more preferably 20 μm or more. In addition, if the bubble diameter becomes larger, the actual area in contact with the object to be polished tends to decrease. In order to obtain a high polishing rate, the bubble diameter is preferably 100 μm or less, more preferably 50 μm or less. The proportion of air bubbles in the polishing layer can be appropriately determined depending on the object to be polished, and is usually about 5 to 40% of the volume of the polishing layer, preferably 10 to 30%.

In the polishing pad of the present invention, it is preferable that the polishing layer is formed on a polymer substrate.

The polymer substrate is preferably a polyester sheet, an acrylic sheet, an ABS resin substrate, a polycarbonate sheet, or a vinyl chloride resin sheet. Particularly preferably, the polymer substrate is a polyester sheet.

Among the polishing pads, those having a polishing layer formed on a polymer substrate can be used. The polymer substrate is not particularly limited, and those exemplified above are ideal, but a polyester sheet is particularly preferable from the viewpoint of adhesiveness, strength, environmental load, and the like.

In the polishing pad, it is desirable that the thickness of the polishing layer is 10 to 500 μm.

In addition, the polishing pad of the present invention is characterized in that it has a structure in which a buffer layer made of a material softer than the polishing layer is laminated on a polymer substrate on which the polishing layer is formed.

In the polishing pad, it is desirable that the buffer layer has an Asker C (Asker C) hardness of 60 or less.

In the polishing pad, it is desirable that the laminated buffer layer is made of polyester fiber non-woven fabric, polyurethane resin impregnated in the non-woven fabric, polyurethane resin foam, or polyethylene resin foam .

In the present invention, the uniformity of polishing rate over the entire surface of a polished silicon wafer is improved by laminating a polymer substrate supporting a resin layer (polishing layer) in which abrasive grains are dispersed and a softer buffer layer. The buffer layer used in the present invention preferably has an Ascar C hardness of 60 or less in order to ensure uniformity of the wafer. In addition, the buffer layer of the present invention preferably uses a non-woven fabric made of polyester fibers and impregnates the polyurethane resin into the non-woven fabric in order to achieve an Ascar C hardness of 60 or less. It is particularly desirable to use a polyurethane resin foam or a polyethylene resin foam. The thickness of the buffer layer is preferably in the range of 0.5 mm to 2 mm so as not to affect the uniformity of polishing during polishing.

In the polishing pad, it is desirable that the thickness of the polishing layer is 250 μm to 2 mm.

The polishing pad preferably has a residual number of 90 or more in the adhesive strength between the polishing layer and the polymer substrate in a cross-cut test.

As for the polishing pad, it is desirable to bond the polymer substrate and the buffer layer together with an adhesive or a double-sided tape.

The abrasive layer preferably has an adhesive strength of 600 g/cm or more in a 180-degree peel test between the polymer substrate and the buffer layer.

The polishing pad of the present invention preferably has grooves formed in the polishing layer.

Ideally, the grooves are latticed. In addition, the groove pitch of the grooves is preferably 10 mm or less. In addition, it is desirable that the grooves are concentric. In addition, the depth of the groove is preferably 300 μm or more.

Grooving can be performed on the polishing layer of the polishing pad of the present invention. When there are no grooves in the polishing layer, when the wafer is polished, the wafer is attached to the polishing layer to generate a great frictional force, so that the wafer cannot be held and the polishing cannot be performed. The processing shape of the groove of the present invention can be any shape. For example, perforated shape, radial groove shape, grid shape, concentric circle shape, spiral shape, arc shape, etc., ideally grid shape or concentric shape round shape. The depth of the grooves in the present invention is preferably 300 μm or more from the viewpoint of water drainage, grinding slag discharge, and the like. In addition, in the case of forming grid-like grooves in the present invention, it is desirable that the pitch of the grooves is at least 10 mm or less. If the groove pitch is larger than 10 mm, the groove formation effect becomes poor, and the above-mentioned sticking of the wafer occurs. The manufacturing method of the groove of the present invention is not particularly limited, and as one example thereof, a method of forming a groove by grinding with an abrasive tool; a method of forming a groove by cutting with a metal cutting blade; Such as laser, the method of forming grooves; the method of pressing the resin layer mixed with abrasive grains before coating and drying to form grooves; the method of forming groove-shaped grooves by pressing after the coating layer is completely formed, etc. .

Description of drawings

FIG. 1 is a cross-sectional view showing the structure of a polishing pad.

FIG. 2 is a view showing a state in which a mask material is placed on a thin plate-shaped molded body of a curable composition and exposed to form a polishing layer having recesses penetrating in the thickness direction.

FIG. 3 is a view showing a state in which a polishing layer having unevenness is formed by placing a mask material on a thin plate-shaped molded body of a curable composition and exposing it.

Fig. 4 is a diagram showing a step of forming concavities and convexities on both surfaces of a sheet-shaped molded body of a curable resin composition having a single-layer structure to form a polishing pad.

Fig. 5 is a conceptual diagram showing polishing of an object to be polished using the polishing pad of the present invention.

FIG. 6 is a conceptual diagram showing polishing of an object to be polished using a conventional polishing pad.

Detailed ways

<(I) Polishing Pad>

The structure of the polishing pad is shown in FIG. 1 .

FIG. 1( a ) is a diagram showing a polishing pad 41 having a general structure composed of a polishing layer 42 and a buffer layer 45 . Fig. 1(b) is a diagram showing a polishing layer 42 formed with a polishing surface layer 43 and a backside layer 44 using a thin plate-shaped molded body of a curable composition cured by irradiation of energy rays, and the backside layer 44 has properties as a buffer layer , can be used directly as a grinding pad. FIG. 1( c ) is an example of a polishing pad in which a buffer layer 45 is further laminated on the back layer 44 side of the polishing layer 42 shown in FIG. 1( b ).

In the present invention, when an energy ray reactive composition is used to form a polishing layer or a polishing pad, the energy ray reactive composition includes an initiator and an energy ray reactive compound. The energy ray reactive compound may be a solid energy ray reactive high molecular compound or a liquid energy ray reactive high molecular compound, but in the case of a liquid energy ray reactive high molecular compound, preferably Contains solid polymer compound (polymer resin). In addition, in the case where the energy ray becomes insoluble in the solvent, it is desirable to use both a solid energy ray reactive high molecular compound and a liquid energy ray reactive high molecular compound as the energy ray reactive compound in order to use The reaction by the energy ray proceeds rapidly (hereinafter, the energy ray reactive compound may be referred to as a photocurable compound).

The solid in the present invention refers to a substance that does not have fluidity at 25° C., and the fluidity refers to a substance that can be seen spreading after a period of time when the substance is placed on a flat surface. Rubbery or viscoelastic substances are included in the scope of the solids of the present invention because they cannot be seen to spread over time.

The solid energy ray curable composition of the present invention refers to a composition that undergoes a chemical reaction, especially a polymerization reaction, by energy rays and has no fluidity in a room. The energy rays mentioned here refer to visible rays, ultraviolet rays, electron rays, ArF lasers, KrF lasers, and the like.

As the energy ray curable compound, especially the photocurable compound, any compound can be used without limitation as long as it undergoes photopolymerization and crosslinking reaction, and monomers, oligomers, polymers, or mixtures thereof can be used . As related compounds, (meth)acrylates (acrylates and/or methacrylates, epoxy (meth)acrylates, (meth)acrylates having a benzene ring in the molecule can be exemplified. , (meth)acrylate of polyoxyalkylene polyol, these may be used individually or in combination of 2 or more types. As each (meth)acrylate, the following compound is mentioned specifically.

Acrylates or methacrylates of polyhydric alcohols include diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, hexapropylene glycol diacrylate, trimethylolpropane triacrylate, and pentaerythritol triacrylate. , 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, dipentaerythritol pentaacrylate, trimethylol propane trimethacrylate, low butadiene diol diacrylate, lauryl Methacrylate, polyethylene glycol diacrylate, N, N-dimethylaminopropyl methacrylamide, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, etc.

Examples of epoxy acrylates include 2,2-bis(4-methacryloyloxyphenyl)propane, 2,2-bis(4-acryloyloxyphenyl)propane, trimethylolpropane monohydric Glyceryl ether or diglycidyl ether acrylate or methacrylate, bisphenol A/epichlorohydrin-based epoxy resin (bisphenol-based epoxy resin) hydroxyl group with acrylic acid or methacrylated derivatives, etc. .

Moreover, as a (meth)acrylic acid ester which has a benzene ring in a molecule|numerator, the low molecular weight unsaturated polyester etc., such as the condensate of phthalic anhydride-pentaerythyl glycol-acrylic acid, etc. are mentioned.

Examples of (meth)acrylates of polyoxyalkylene polyols include methoxypolyethylene glycol acrylate, phenoxypolypropylene glycol acrylate, methoxypolypropylene glycol methacrylate, phenoxypolyethylene glycol acrylate, and methoxypolyethylene glycol acrylate. Glycol Acrylate, Phenoxy Polypropylene Glycol Methacrylate, Phenoxy Polypropylene Glycol Acrylate, Methoxy Polypropylene Glycol Methacrylate, Nonylphenoxy Polyethylene Glycol Acrylate, Nonylphenoxy Polyethylene glycol methacrylate, nonylphenoxy polypropylene glycol acrylate, nonylphenoxy polypropylene glycol methacrylate, etc.

It is also preferable to use a urethane-based curable compound instead of the above-mentioned (meth)acrylate or together with the (meth)acrylate, especially a urethane-based (meth)acrylate compound. The urethane curable compound is obtained by reacting a polyfunctional active hydrogen compound, a polyisocyanate compound, and an ethylene polymerizable compound having an active hydrogen group.

As the polyisocyanate compound constituting the urethane-based curable compound, compounds known in the field of polyurethane can be used without limitation. Specifically, aromatic diisocyanates such as 2,4-toluene diisocyanate (TDI) and 4,4'-diphenylmethane diisocyanate (MDI); fatty acids such as hexamethylene diisocyanate and isophorone diisocyanate; family or cycloaliphatic diisocyanates; xylylene diisocyanate, etc.

Specific examples of vinyl polymerizable compounds having active hydrogen groups constituting urethane-based curable compounds include those having hydroxyl groups and ethylenically unsaturated groups such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate. compound.

As the polyfunctional active hydrogen compound constituting the curable urethane compound, low molecular weight polyols such as ethylene glycol or propylene glycol, polyoxypropylene polyols with a molecular weight of 400 to 8000, polyethylene glycol, poly Oxidized tetramethylene polyols such as ethylene oxide, propylene oxide, tetrahydrofuran and other cyclic ether polyols ring-opened; adipic acid, azelaic acid, phthalic acid and other dicarboxylic acids and ethyl Polyester polyols composed of diols; or polyester polyols which are ring-opening polymers of lactones such as ε-caprolactone; polycarbonate polyols, and the like. Among these polyol compounds, it is preferable to use a polyether-based polyol because it is highly effective in improving compression properties. These urethane-based curable compounds may be used alone or in combination of two or more.

The urethane-based curable compound can be produced, for example, by the following method.

(1) Ethylene glycol and a diisocyanate compound as a polyfunctional active hydrogen compound react with an equivalent ratio (NCO/OH) of an isocyanate group and an active hydrogen group of 2 as an NCO terminal prepolymer, and then make a compound having a hydroxyl group and The ethylenically unsaturated compound reacts with the NCO-terminated prepolymer at NCO/OH=1.

(2) A compound having a hydroxyl group and an ethylenically unsaturated group is reacted with a diisocyanate compound at NCO/OH=2 as a compound having an NCO group and an ethylenically unsaturated group, and then the compound and a polyol compound are reacted at NCO/OH=2. OH=1 to react.

UA-306H, UA-306T, UA-101H, Actilane 167, Actilane 270, Actilane 200 (AKCROSCHEMIALS, Inc.) etc. are commercially available as a urethane type curable compound, and can be used suitably.

Any liquid photoreactive compound can be used without limitation as long as it chemically reacts with light, but it is desirable to use one with a high photosensitive group weight concentration per unit molecule in order to improve sensitivity. The photosensitive group weight concentration is preferably 30% by weight or more. Specifically, alkyl glycol dimethacrylate having C7 or less, trimethylolpropane trimethacrylate, dipentaerythritol hexaacrylate, etc. may be mentioned, but not limited thereto. These liquid photoreactive compounds can be used in combination with solid polymer compounds. As a solid polymer compound, a solid photoreactive polymer compound is desirable.

The solid photoreactive polymer compound used as a constituent material of the curable composition is not limited as long as it undergoes a chemical reaction with light, specifically

①Introducing active vinyl-containing compounds or aromatic polycyclic compounds into the main chain or side chain of the polymer;

Unsaturated polyester polycondensed with polyvinyl cinnamate, p-phenylene diacrylic acid and ethylene glycol; esterified cinnamylidene acetic acid in polyvinyl alcohol; introduced cinnamon aldehyde into the main chain or side chain of the polymer group, cinnamylidene group, phenylstyrene residue, isocoumarin residue, 2,5-dimethoxystilbene residue, styrylpyridinium residue, thymine residue, α-phenylmaleic residue Anhydride imide, anthracene residue, 2-coumarin and other photosensitive groups;

②Introducing a diazo or azido group into the main chain or side chain of the polymer;

Paraformaldehyde condensate of p-diazodiphenylamine, paraformaldehyde condensate of phenyldiazo-4-(anilino)-phosphate, salt addition of methoxybenzenediazo-4-(anilino) Formaldehyde condensates, polyethylene-p-benzyl azide resin, azide acrylate, etc.

③Introduction of polymers with phenol esters on the main chain or side chain;

Polymers with unsaturated carbon-carbon double bonds introduced with (meth)acryloyl groups, unsaturated polyesters, unsaturated polyurethanes, unsaturated polyamides, unsaturated carbon-carbon double bonds introduced with ester bonds on the side chains Polyacrylic acid, epoxy acrylate, novolac acrylate, etc.

In addition, various photosensitive polyimides, photosensitive polyamic acids, photosensitive polyamideimides, etc., and phenol resins can be used in combination with an azide compound. In addition, an epoxy resin or a polyamide introduced into a chemical crosslinking type site may be used in combination with a photocationic polymerization initiator. It is also possible to use natural rubber, synthetic rubber, cyclized rubber in combination with a bis-azide-based compound.

When using a curable composition to manufacture the polishing pad of the present invention, it is an ideal form to add a photoinitiator to the curable composition. As the initiator, any known compound can be used without limitation, as long as it is a known compound that absorbs energy by irradiation of energy rays to cause cracks or the like, generates polymerization active species, and initiates a polymerization reaction. For example, a substance that initiates photocrosslinking, a substance that initiates photopolymerization (radical polymerization, cationic polymerization, anionic polymerization), a substance that changes its structure by light to change its dissolution characteristics, and a substance that generates an acid by light, etc.

As the photoradical polymerization initiator, for example, when using ultraviolet rays near the i line (365nm) as a light source, aromatic ketones, benzoin, benzyl derivatives, imidazoles, acridine derivatives, N - Phenyl amino acids, bis-azide compounds, etc. Specifically, the following compounds may be mentioned.

Aromatic ketones: benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4-methoxy- 4'-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butane-1-one, 2-ethylanthraquinone, phenanthrene quinone, etc.

Benzoin: methyl benzoin, ethyl benzoin, etc.

Benzyl derivatives: benzyl dimethyl ketal, etc.

Imidazoles: 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer; 2-(o-chlorophenyl)-4,5-bis(m-methoxyphenyl)imidazole Dimer; 2-(o-fluorophenyl)-4,5-phenylimidazole dimer; 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer; 2 -(p-methoxyphenyl)-4,5-diphenylimidazole dimer; 2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer, etc.

Acridine derivatives: 9-phenylacridine, 1,7-bis(9,9'-acridyl)heptane, etc.

The said photoinitiator can be used individually or in combination of 2 or more types. The addition amount of these photoinitiators is preferably about 0.001 to 20% by weight relative to the curable composition.

As a photocationic polymerization initiator, the thing which generate|occur|produces an acid by light is mentioned. Specifically, there are aryldiazonium salts, diaryliodonium salts, triarylsulfonium salts, triarylstrontium salts, dialkylphenacylsulfonium salts, dialkyl-4-hydroxyphenylsulfonium salts, Sulfonate esters, iron-aromatic compounds, silanol-aluminum complexes, etc.

In the present invention, as the solid polymer constituting the curable composition, in order to improve the mechanical properties of the polishing pad such as elastic modulus (Young's modulus), volume hardness, compressibility, compression recovery rate or in order to reduce the aging time of the polishing pad before photoreaction Thickness changes and can be added. Polyolefins such as poly(meth)acrylate, polyvinyl alcohol, polyester, polyamide, polyurethane, polyimide, polyamideimide, polycarbonate, polyethylene, or polypropylene, or their composites can be exemplified. Substances, mixtures, and the like are not limited as long as they are solid polymers that can achieve the above-mentioned purpose.

As the curable composition, a commercially available one can be used, and as the photosensitive sheet, a curable composition sold in a sheet form can be used.

A method for producing a polishing layer having unevenness on the surface by photolithography using the energy ray-curable composition of the present invention will be described with reference to the drawings.

FIG. 2 shows a situation where the polishing layer in the polishing pad has unevenness. A thin plate-shaped molded article 1 using a curable composition is formed between a base film 5 and a protective film 3 . The abrasive material M is placed on the protective film 3 side, and a predetermined amount of light L is irradiated. On the mask, the masking portion MS and the light transmitting portion MP are arranged to form concavities and convexities of a predetermined pattern, and the exposed portion 1S and the unexposed portion 1H are formed by irradiation of light. If the curable composition is a negative type, when the unexposed portion 1H is removed with a solvent or the like (developing step), the polishing layer 1 having unevenness in a desired pattern is formed from a thin plate-shaped molded body.

When the polishing pad of the present invention is non-foamed, an adsorption phenomenon occurs between materials to be polished such as wafers or glass plates. For example, during the polishing process of the wafer, the wafer sometimes falls out of its fixing table. If the polishing pad is a foam, the adsorption phenomenon between the polishing pad and the material to be polished is less likely to become a major problem. It is considered that this is because, when the polishing pad is a foam, there are a lot of micropores on the surface of the polishing layer, which is in the state of fluff from a microscopic view, so the friction with the material to be polished is reduced, and the adsorption does not become a big problem. question.

According to the above phenomenon, the results of investigating the friction coefficient between glass and polishing pad under a certain load, set the pattern of the polishing surface so that the static friction coefficient is 1.49 or less, and the dynamic friction coefficient is 1.27, even if the polishing pad is not foamed. , It is also possible to prevent the adsorption phenomenon between the abrasive materials such as wafers and glass plates.

The concavo-convex effect of the grinding surface is also applicable to the situation where the finishing process is removed from the grinding process. The dressing process means that during the grinding process, the abrasive grains and grinding debris in the slurry are accumulated in the pores of the grinding surface, which reduces the grinding speed. Surface, and the process of creating a new grinding surface. Even when the above-mentioned dressing step is omitted and the polishing pad of the present invention is used as an undressed polishing pad, the above-mentioned effect of the coefficient of friction can be maintained.

However, the above-mentioned dressing process does not include dressing in which dressing is performed at the start of polishing in order to improve the flatness of the polishing pad.

A polishing pad can be obtained by laminating a back layer as a buffer layer on the polishing layer 1 .

In the example shown in FIG. 2, the concavo-convex recesses penetrate through the abrasive layer, and are suitable for hole processing, for example. FIG. 3 exemplifies a method of forming unevenness that is also suitable for grooving. The thin plate-shaped molded body 11 is the same as in FIG. 2, and is formed between the base film 13 and the protective film 17. The mask material M is placed on the concave-convex side, and the base film surface 13 side is exposed without the mask material. The fully exposed cured layer 15 is formed on the base film surface 13 side, the unexposed portion 11H and the exposed portion 11S are formed on the protective film 17 side, and a polishing layer 11 having concave portions 11S and convex portions 11H is formed through a developing process. The light irradiated on the base film surface 13 side is adjusted so that the cured layer 15 with a predetermined thickness is formed.

The thickness of the concavo-convex recesses can be appropriately set according to the application, material, etc., and is not limited. The depth of the recesses is preferably adjusted to be 100 μm (0.1 mm) or more and within 2/3 of the thickness of the spacer. The depth of the concave portion can also be adjusted by development.

In the above example, the example of manufacturing the polishing layer was described, but the unevenness of the back layer as the buffer layer can also be formed in the same way.

In the manufacturing method of FIG. 2, if a well-known filler material is used instead of the base film 5, it will become the polishing pad provided with a cushion layer. In addition, a known polishing pad can be used instead of the base film 5, and a material suitable for forming a cushion layer can be used as a curable composition to form a polishing pad.

The polishing layer 1 and the back layer may be formed separately via an intermediate layer. The intermediate layer may be used by curing the curable composition used in the present invention, or other materials may be used. It is also possible to produce the abrasive layer by the method shown in FIG. 3, and after peeling off the base film, use it instead of the base film in FIG.

In FIG. 4 , an example in which the abrasive layer is composed of an abrasive surface layer and a back layer is illustrated. In this example, an example of manufacturing a polishing pad in which unevenness is formed on the surface and the back surface, and the polishing surface layer and the back surface layer are continuously integrally formed is illustrated. A thin plate-shaped molded body 25 as a polishing pad is composed of a layer as a polishing surface layer 21 and a layer as a back layer 23 , and both surfaces of the thin plate-shaped molded body are covered with protective films 26 and 28 . On the protective film 26 of the grinding surface layer 21 and the protective film 28 of the back layer 23 formation surface, respectively put the mask material M1 suitable for the concavo-convex pattern of the grinding surface and the mask material suitable for the concavo-convex pattern of the surface of the back layer 23. M2 performs an exposure process with light L through the mask materials M1 and M2, and then performs a development process to manufacture a polishing pad.

In the present invention, energy rays are irradiated to a solid thin plate-shaped molded body, and then dissolved in a solvent to form concavo-convex shapes.

When irradiating energy rays, there are methods of irradiating laser light or throttling energy rays directly according to the desired concave-convex shape, or laminating a film with a transmissive part and a non-transmissive part corresponding to the concave-convex shape on one side. A method of irradiating the film surface with energy rays. In addition, at this time, in order to increase the degree of adhesion between the film and the sheet-like structure, it may be irradiated under vacuum.

In addition, in the irradiation of energy rays, photocuring may be performed by irradiating energy rays from the surface constituting the pattern and the surface on the opposite side until the thickness does not affect the depth of the pattern.

In addition, by adjusting the irradiation intensity from the back surface and the irradiation intensity from the surface, it is possible to produce a polishing pad with hardness distribution in the thickness direction of the pad and an optimal balance in the thickness direction.

In the present invention, due to the chemical reaction of the energy ray, the solubility of the energy ray permeable portion and the non-permeable portion to the solvent is different, and is selectively removed with an appropriate solvent. The solvent is not particularly limited, and can be appropriately selected according to the raw material used. Depending on the situation, in order to increase the removal efficiency, the removal solvent may be used after being heated to a certain temperature.

The pattern on the surface of the pad may, for example, be cylindrical, conical, linear grooves, orthogonal grooves, pyramids, holes, or complexes thereof. The hardness or elastic properties of the material to be polished, the size, shape, or hardness of the abrasive grains of the slurry used, and when laminating, select the most suitable concave-convex shape for each condition according to the hardness, elastic properties, etc. of layers other than the abrasive layer.

In addition, when the polishing pad of the present invention is non-foamed, it is adsorbed to objects to be polished such as wafers or glass plates, and the wafer may detach from the wafer fixing table during the polishing process. In the case of a foamed body, there are many micropores on the surface of the polishing layer, and it is microscopically fuzzy, the friction with the object to be polished is reduced, and the adsorption with the wafer is less likely to become a major problem. Therefore, in the present invention, as a result of investigation based on the coefficient of friction of glass and polishing pad under a certain load, when using a surface pattern whose dynamic coefficient of friction is 1.27 or less and the static friction coefficient is 1.49 or less, the above-mentioned problems are solved. for the ideal.

In addition, the above results are also applicable to the case of canceling the dressing process in the grinding process. The dressing process refers to the case of foam, because during the grinding process, the abrasive grains and grinding debris in the slurry are accumulated in the pores of the grinding surface, which reduces the grinding speed. The process of grinding the head of the grain, modifying the grinding surface, and creating a new grinding surface. The above-mentioned coefficient of friction is also effective when the above-mentioned dressing step is omitted and the polishing pad of the present invention is used as a non-dressed polishing pad.

However, the above-mentioned dressing step does not include dressing performed at the start of polishing in order to improve the flatness of the polishing pad.

In addition, in the grinding process, it is also possible to reduce clogging in the unevenness by washing with a brush, washing with high-pressure water, etc. without scraping the surface of the liner.

The polishing pad of the present invention preferably has a transmittance of 1% or more at the wavelength of energy rays used. If it is less than 1%, the irradiation energy of light will be insufficient and the reaction will not proceed efficiently.

In the polishing pad of the present invention, as a method for manufacturing a polishing layer having a hardness difference between the surface portion or the middle portion constituting the polishing layer and the back layer or the polishing layer of the polishing pad, a curable composition, such as an energy ray-containing The composition of the curable composition or the thermosetting composition is formed into a thin plate-shaped molded body, and then at least one of energy rays and heat is applied to the molded body. Specifically, the polishing pad of the present invention is manufactured by controlling energy rays or heat for inducing reaction and curing of these curable compositions.

The method of producing a difference in hardness between the polishing layer and the back layer by using a composition containing an energy ray-curable compound, for example, can control the transmission of the curable composition by controlling the intensity of energy rays such as irradiated light, the irradiation time, and other irradiation conditions. Rate etc. at least one method implementation. According to the method of controlling the permeability, the irradiated energy rays are absorbed little by little in the layer, and the irradiation intensity decreases from the energy ray irradiation part along the direction reaching the inside of the thin plate-shaped molded body, and the abrasive layer and the Differences in crosslinking reactions occur between back layers, resulting in differences in mechanical properties such as hardness.

In addition, by controlling the addition of the above-mentioned additives or the refractive index of each component of the composition, the transmittance of the curable composition can be controlled, and by changing the light energy in the layer, the difference in the crosslinking reaction in the layer is caused, and The mechanical properties such as hardness and compression properties in the abrasive layer are different. Therefore, a polishing pad capable of forming both a polishing layer and a cushioning layer on a single sheet has the necessary surface hardness and cushioning properties, and can improve the flatness and uniformity of the object to be polished.

The thin-plate-shaped molded body when manufacturing the above-mentioned polishing pad or the polishing layer constituting the polishing pad can be obtained by mixing the composition, forming a thin-plate-shaped molded body by a conventional thin-plate molding method, and then using an energy ray source such as ultraviolet light to cure it. . In addition, it can also be obtained by the method of coating a composition on a base material.

When the solvent is used as one component of the curable composition, after mixing, the solvent is removed under reduced pressure to form a thin plate-shaped molded body. Alternatively, after forming a thin plate-shaped molded body, it may be dried and removed before or after curing.

The thickness of the polishing pad is appropriately set according to the purpose of use, and is not particularly limited, and is used, for example, within a range of 0.1 to 10 mm. The thickness of the polishing pad is more preferably 0.2 to 5 mm, particularly preferably 0.3 to 5 mm. When the back layer is laminated separately, the thickness of the abrasive layer is preferably 0.1 to 5 mm, more preferably 0.2 to 3 mm, and particularly preferably 0.3 to 2 mm.

The polishing layer is preferably formed into a thin plate-shaped molded body formed by foaming a curable composition by mechanical foaming or chemical foaming, and then subjected to an exposure step and a development step to form a foamed layer.

For the protective film or the support, a thin film of a material that does not prevent light exposure and is permeable to energy rays is used. The protective film and the base film may be the same or different. The support may be thin such as a base film or thick such as a plastic plate. As the film or support, known resin films such as PET films, polyamide films, polyimide films, aramid resin films, polypropylene films, etc. can be used, and release treatment is performed as necessary. Both surfaces of the sheet-shaped molded article may be covered with a film.

In the case where the sheet-shaped molded article has no adhesiveness and there is no problem of adhesion or contamination of the mask material when it is directly placed on the mask material, the protective film or the base film may not be required.

As the protective film, it is preferable to use a protective film coated with an antistatic agent to prevent static electricity at the time of peeling, since it is difficult for dust and the like to enter. There are no restrictions on the shape, width, pitch, depth, etc. of the concavo-convex, depending on the hardness or elastic properties of the material to be ground, the size or shape or hardness of the abrasive grains of the slurry used, and in the case of lamination, according to the thickness of the layer other than the abrasive layer. Choose the most suitable concavo-convex shape for each condition, such as hardness and elastic properties.

By forming irregularities on the surface of the polishing layer, it is possible to obtain the effect of improving the fluidity of the slurry, improving the retention of the slurry, or improving the elastic properties of the surface of the polishing layer. When unevenness is formed on the back layer, cushioning properties suitable for the back layer can be imparted.

The polishing layer in the polishing pad of the present invention can be formed using a curable composition containing a thermosetting compound that reacts and cures with heat. As a method of using the thermosetting composition to create a difference in hardness between the surface and the middle of the polishing layer and the back layer, for example, it can be implemented by controlling the amount of heat applied to the composition. A difference in crosslinking reaction occurs between the high-temperature portion, that is, the portion that receives a large amount of heat, and the low-temperature portion, thereby causing a difference in mechanical properties such as hardness.

As the thermosetting resin, any compound that undergoes a curing reaction with heat can be used without limitation. Specifically, bisphenol A type epoxy resin; bisphenol F type epoxy resin; bisphenol novolak type epoxy resin; cresol novolak type epoxy resin; ester epoxy resin; ether epoxy resin; Ester-modified epoxy resins; alicyclic epoxy resins with skeletons such as cyclohexane, dicyclopentadiene, and fluorene; hindered phenolic epoxy resins; epoxy resins such as amino epoxy resins; Maleic anhydride imide resin; compounds containing isocyanate group; melamine resin; phenol resin, acrylic resin, etc. These can be used individually or in combination of 2 or more types. In addition, it is also desirable to add a curing agent to these thermosetting resins and use them as curable compositions.

As the curing agent, bis(4-aminophenyl)sulfone, bis(4-aminophenone)methane, 1,5-diaminonaphthalene, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 2,6-dichloro-1,4-phenylenediamine, 1,3-bis(p-aminophenyl)propane, m-xylylenediamine and other aromatic amine compounds; ethylenediamine, diethylene Triamine, tetraethylenepentamine, diethylaminopropylamine, 1,6-hexanediamine, menthenediamine, isophoronediamine, bis(4-amino-3-methyldicyclohexyl)methane , polymethylene diamine, polyether diamine and other aliphatic amine compounds; polyamine amide compounds, lauryl succinic anhydride, poly adipic anhydride, poly azelaic anhydride and other aliphatic anhydrides; hexahydrophthalic anhydride Cycloaliphatic acid anhydrides such as formic anhydride and methylhexahydrophthalic anhydride; phthalic anhydride, trimellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bis-trimellitate, glycerol trimide Aromatic acid anhydrides such as trimellitate; phenol resins; amino resins; urea-formaldehyde resins; melamine resins; dicyandiamide and dihydrazine compounds; imidazole compounds; alcohol compounds; isocyanate and blocked isocyanate compounds, etc., but not limited to these. These curing agents and their compounding amounts are appropriately selected and used according to the thermosetting resin to be used.

In addition, in the present invention, abrasive grains or other various additives may be added as necessary to the curable composition cured by heat or energy rays in order to improve abrasiveness, mechanical properties, processability, and the like. For example, antioxidants, ultraviolet absorbers, antistatic agents, pigments, fillers, non-photocurable or thermosetting polymer resins, tackifiers, thermal polymerization inhibitors, and the like can be mentioned. As the abrasive grains, there are no particular limitations depending on the object to be polished, and examples include silicon oxide (silicon dioxide), aluminum oxide (aluminum oxide), cerium oxide (cerium oxide) composed of particles of several micrometers or less. )wait.

In addition, when it is desirable that the abrasive layer has no voids, the bubbles added to the abrasive layer are preferably bubbles with a solid center.

In the present invention described above, the sheet-shaped molded article is produced by a usual coating method or sheet forming method. As a usual coating method, coating methods such as heating or dissolving in a solvent, doctor blade coating, spin coating, etc. can be employed. As the thin plate forming method, known thin plate forming methods such as using a press machine, press rolls, etc. after heating, extrusion molding from a die, or calendering can be used.

In the present invention, the thin plate-shaped molded article can be used in various forms. For example, sheet shape, round shape, ribbon shape, roll shape, ribbon shape, etc. It is best to choose according to the grinding method.

When coating and forming a sheet-shaped molded article using a curable composition that is cured by energy rays, especially by light, it may also include dissolving a photoinitiator or a photoreactive compound in a solvent depending on the equipment and mechanical conditions used. It is a process of kneading in middle and then removing the solvent before or after forming.

In addition, the polishing pad of the present invention can be laminated with other thin plates. Examples of other laminated materials include cushioning materials having a higher compressibility than the polishing pad, materials having a higher elastic modulus than the polishing pad and imparting rigidity to the polishing pad, and the like.

As a cushioning material with a higher compressibility than the polishing pad, resin foams such as foamed polyurethane, foamed polyethylene, and foamed rubber can be used; non-foamed polymer materials such as rubber and gel; non-woven Cloth; non-woven fabric impregnated with resin, napped cloth, etc. When these cushioning materials are stacked, the uniformity of the polishing rate partially seen microscopically is improved.

The elastic modulus is higher than the elastic modulus of the polishing pad and the object that imparts rigidity to the polishing pad can be exemplified by polyethylene terephthalate, nylon, polycarbonate, polypropylene, polyvinyl chloride, polyvinylidene chloride, Resin film or plate of polyacrylate, etc.; metal foil of aluminum, copper, stainless steel, etc.; etc. By stacking these rigid materials, the polishing flatness is improved in the case of excessive shaving of the peripheral portion of the polishing object or the polishing object in which a plurality of raw materials are exposed.

In order to improve the flatness and ensure the uniformity of the polishing rate, it is desirable to laminate a rigidity-imparting layer between the cushioning object and the polishing pad of the present invention.

Moreover, as a lamination method, arbitrary methods, such as an adhesive agent, a double-sided tape, and thermal fusion, can be used.

The polishing layer of the polishing pad of the present invention is not particularly limited in terms of its forming material as long as the storage elastic modulus is 200 MPa or more. For example, a polyester resin, a polyurethane resin, a polyether resin, an acrylic resin, an ABS resin, a polycarbonate resin, or a blend of these resins, a photosensitive resin, etc. are mentioned. Among them, polyester resins, polyurethane resins, or photosensitive resins are desirable.

(polyester resin)

The polyester resin is composed of one or more polyvalent carboxylic acids selected from dicarboxylic acids and their ester-forming derivatives and one or more polyvalent carboxylic acids selected from ethylene glycol. Alcohols; or hydroxycarboxylic acids and their ester-forming derivatives; or cyclic esters; polyester resins are obtained by polycondensation of them.

Examples of dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decane dicarboxylic acid, Alkane dicarboxylic acid, tetradecane dicarboxylic acid, hexadecane dicarboxylic acid, 1,3-cyclobutane dicarboxylic acid, 1,3-cyclopentane dicarboxylic acid, 1,2-cyclohexane dicarboxylic acid Saturated aliphatic dicarboxylic acids or their ester-forming derivatives; unsaturated aliphatic dicarboxylic acids or their ester-forming derivatives such as fumaric acid, maleic acid, itaconic acid, etc.; terephthalic acid, isophthalic acid, Terephthalic acid, 5-(alkali metal) thioisophthalic acid, biphenylnic acid, 1,3-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, 4,4'-biphenylsulfodicarboxylic acid, 4,4'-biphenyl ether Aromatic dicarboxylic acids such as dicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, pamoic acid, anthracene dicarboxylic acid, etc., or their ester-forming derivatives thing. Among these dicarboxylic acids, terephthalic acid and naphthalene dicarboxylic acid are preferable, and 2,6-naphthalene dicarboxylic acid is particularly preferable.

Examples of polyvalent carboxylic acids other than these dicarboxylic acids include ethanetricarboxylic acid, propanetricarboxylic acid, butane tetracarboxylic acid, pyromellitic acid, trimellitic acid, trimellitic acid, 3, 4 , 3', 4'-biphenyl tetracarboxylic acid, and their ester-forming derivatives.

Examples of diols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, triethylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3- Cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediethanol, Aliphatic alcohols such as 1,10-decanediol, 1,12-dodecanediol, polyethylene glycol, polytrimethylene glycol, and polytetramethylene glycol; hydroquinone, 4,4 '-Dihydroxybisphenol, 1,4-bis(β-hydroxyethoxy)benzene, 1,4-bis(β-hydroxyethoxyphenyl)sulfone, bis(p-hydroxyphenyl)ether, bis(p-hydroxyphenyl) Hydroxyphenyl) sulfone, bis(p-hydroxyphenyl)methane, 1,2-bis(p-hydroxyphenyl)ethane, bisphenol A, bisphenol C, 2,5-naphthalene diol, addition of these alcohols Ethylene oxide alcohols are examples of aromatic alcohols. Among these alcohols, ethylene glycol and 1,4-butanediol are preferable.

Examples of polyhydric alcohols other than these alcohols include trimethylolmethane, trimethylolethane, trimethylolpropane, pentaerythritol, glycerol, hexanetriol and the like.

Examples of hydroxycarboxylic acids include lactic acid, citric acid, malic acid, tartaric acid, glycolic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and 4-hydroxycyclohexane Carboxylic acids, or their ester-forming derivatives, etc.

Examples of cyclic esters include ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide, and lactide.

(Polyurethane resin)

Polyurethane resin is obtained by reacting polyisocyanate, polyol and chain extender as needed. These polyurethane resins can be obtained by reacting the above-mentioned components collectively, or by preparing an isocyanate-terminated urethane prepolymer from polyisocyanate and polyol, and then reacting a chain extender. As the polyurethane resin, one obtained by reacting an isocyanate-terminated urethane prepolymer with a chain extender is desirable.

Examples of polyisocyanates are 2,4- and/or 2,6-diisocyanate toluene, 2,2'-, 2,4'- and/or 4,4'-diisocyanate diphenylmethane, 1,5 - naphthalene diisocyanate, p- and m-phenylene diisocyanate, dimellyl diisocyanate, xylylene diisocyanate, diphenyl-4,4'-diisocyanate, 1,3- and 1,4-tetramethylbenzene diisocyanate Methylene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecylene diisocyanate, cyclohexane-1,3- and 1,4-diisocyanate, 1-isocyanato- 3-isocyanatomethyl-3,5,5-trimethylcyclohexane diisocyanate (=isocyanate diisocyanate), bis-(4-isocyanatocyclohexyl)methane (=hydrogenated MDI) , 2- and 4-isocyanatocyclohexyl-2-isocyanatocyclohexylmethane, 1,3- and 1,4-bis-(isocyanatomethyl)-cyclohexane, bis(4-isocyanate-3- Methylcyclohexyl)methane, etc. The polyisocyanate is appropriately selected according to the pot life required for injection molding, and since the isocyanate-terminated urethane prepolymer needs to have a low melt viscosity, it is used alone or in a mixture of two or more.

As the polyol, high molecular polyols and low molecular polyols may be exemplified. As the polyol, a polymer polyol is generally used. Examples of the polymer polyol include hydroxyl-terminated polyesters, polyethers, polycarbonates, polyester carbonates, polyether carbonates, and polyester amides.

Examples of hydroxyl-terminated polyesters include reaction products of dihydric alcohols and dibasic carboxylic acids, but in order to improve hydrolysis resistance, the distance between ester bonds is preferable, and a combination of all long-chain components is desirable. As diols, there are no particular limitations, such as ethylene glycol, 1,3- and 1,2-propanediol, 1,4- and 1,3- and 2,3-butanediol, 1,6-hexanediol Alcohol, 1,8-octanediol, octapentanediol, cyclohexanedimethanol, 1,4-bis(hydroxymethyl)-cyclohexane, 2-methyl-1,3-propanediol, 3-methyl Base-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, dibutylene glycol, etc.

As dibasic carboxylic acids, there are aliphatic, alicyclic, aromatic and/or heterocyclic, in order to make the isocyanate-terminated urethane prepolymer liquid or low melt viscosity, aliphatic or alicyclic Dibasic carboxylic acids are ideal, and when aromatics are used, it is desirable to use them in combination with aliphatic or alicyclic. These carboxylic acids are not limited, and examples thereof include succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, Cyclohexanedicarboxylic acid (ortho, meta, para), oleic acid and other dimerized fatty acids, etc.

As hydroxyl-terminated polyesters, there may be carboxy-terminated - moieties. For example, polyesters of lactones such as ε-caprolactone and hydroxycarboxylic acids such as ε-hydroxycaproic acid can be used.

As hydroxyl-terminated polyethers, there may be exemplified starting compounds having reactive hydrogen atoms and alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, tetrahydrofuran, epichlorohydrin, or The reaction product of these alkylene oxide mixtures. As a raw material compound having a reactive hydrogen atom, water, bisphenol A, or the above-mentioned diols used for the production of hydroxyl-terminated polyesters may be exemplified.

As hydroxyl-terminated polycarbonate, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol and/or polytetramethylene glycol can be exemplified. A reaction product of a diol such as a diol with phosgene, a diaryl carbonate (for example, diphenyl carbonate) or a cyclic carbonate (propylene carbonate).

Examples of the low-molecular-weight polyol include diols used in the production of the above-mentioned hydroxyl-terminated polyester.

Chain extenders are compounds having at least 2 active hydrogens at the ends. Such a compound may, for example, be an organic diamine compound or the low-molecular polyhydric alcohols exemplified above. Among them, organic diamine compounds are desirable. The organic diamine compound is not particularly limited, and examples include 3,3'-dichloro-4,4'-diamine diphenylmethane, chloroaniline-modified dichlorodiamine diphenylmethane, 1,2 - Bis(2-aminophenylthio)ethane, 1,3-propylene glycol-di-p-aminobenzoate, 3,5-bis(methylthio)-2,6-toluenediamine, etc.

The polishing pad of the present invention has a buffer layer in addition to the polishing layer. The buffer layer is stacked on the opposite side of the polishing surface of the polishing layer. The cushioning layer has a lower storage modulus than the abrasive layer. The cushion layer is not particularly limited as long as it has a storage elastic modulus lower than that of the abrasive layer. For example, resin-impregnated non-woven fabrics such as non-woven fabrics or polyester non-woven fabrics impregnated with polyurethane, polymer resin foams such as polyurethane foam and polyethylene foam; rubber properties such as butadiene rubber and isoprene rubber. Resin; photosensitive resin, etc. The buffer layer is appropriately selected according to the type of the object to be polished or the polishing conditions to exhibit the characteristics of the buffer layer.

The formation of the polishing layer and buffer layer is not particularly limited, and various methods can be used. For example, each forming material is coated on a substrate, and then dried. The substrate is not particularly limited, and examples thereof include polyester-based, polyamide-based, polyimide-based, polyamide-imide-based, acrylic-based, cellulose-based, polyethylene-based, polypropylene-based, polyolefin-based, Polymer substrates made of polyvinyl chloride-based, polycarbonate-based, phenol-based, and polyurethane-based resins. Among them, a polyester film made of a polyester resin as a raw material is particularly preferable from the viewpoint of adhesiveness, strength, environmental load, and the like. The thickness of the substrate is usually about 50 to 250 μm. The coating method is not particularly limited, and dip coating, brush coating, roll coating, spraying, and other various printing methods can be applied. In addition, each layer can be formed by casting into a predetermined metal mold or the like, or thinning using a calender, extruder, or press.

In the above case, the thickness of the polishing layer and cushioning layer varies with the rigidity required for the polishing pad and the purpose of use, and is not limited. Usually, the polishing layer is about 0.5-2 mm, and the buffer layer is about 0.5-2 mm.

The grinding layer and buffer layer are usually bonded together with double-sided tape. When laminating the polishing layer and buffer layer, the substrate on which each layer is formed can be removed or used as it is. In addition, when laminating the polishing layer and the buffer layer, other layers such as an intermediate layer may be laminated. Adhesive tape for attaching to the platen can be attached to the buffer layer.

In addition, the polishing layer of the polishing pad of the present invention ideally has no voids, so compared with a polishing pad with a foamed polishing layer, it is more important that when the object to be polished is polished, the gap between the polishing layer and the polishing layer is more important. Slurry is kept between objects to be ground. In order to keep the slurry between the grinding layer and the object to be ground, and in order to effectively remove and accumulate the debris generated during grinding, it is ideal to make a groove for the flow of the slurry on the grinding surface of the grinding layer or for the retention of the slurry. pulp part. They can be combined. For example, lattice groove, perforation, concentric circular groove, cylindrical shape, conical shape, linear groove, orthogonal groove, pyramid type, their complexes, etc. There are no restrictions on the concave-convex shape, width, pitch, depth, etc., and the most suitable concave-convex shape for each condition is selected according to the hardness or elastic properties of the material to be polished, the size, shape or hardness of the slurry abrasive grains used, and the grinding conditions. . The processing of the surface shape can be carried out by photolithography in the case of using a photosensitive resin polishing pad for the polishing layer. When using a material other than photosensitive resin, it can be done by using mechanical cutting or laser methods, using grooves, unevenness, etc. Shaped metal mold method and so on.

In addition, the compressibility of the polishing layer of the polishing pad of the present invention is preferably 0.5 to 10%. When the compressibility is less than 0.5%, it becomes difficult to follow the curvature of the object to be polished, and the in-plane uniformity tends to decrease. On the other hand, if the compressibility exceeds 10%, a phenomenon in which the flatness of the local level difference may be lowered in a patterned wafer or the like may occur.

In the present invention, the compressibility and compression recovery rate of the abrasive layer, buffer layer, etc. are measured at 25°C by using a cylindrical indenter with a diameter of 5mm on the processed abrasive layer with TMA manufactured by Maxais. T1 and T2 are obtained according to the following formula.

Compression ratio (%)=100(T1—T2)/T1

Compression recovery rate (%)=100(T3—T2)/T1

T1: Thickness of the sheet when subjected to a stress of 30Kpa (300g/cm ² ) for 60 seconds from the no-load state

T2: Thickness of the sheet when subjected to a load of 180Kpa stress for 60 seconds from the T1 state

T3: Thickness of the thin plate when left in a no-load state for 60 seconds from the state of T2, and then loaded with a stress of 30 Kpa for 30 seconds.

<(I) Cushion layer for polishing pad>

The cushion layer for polishing pads of the present invention may be any of energy ray curable resin, thermosetting resin, and thermoplastic resin, but in consideration of processing such as grooves, energy ray curable resin is ideal, particularly ideal is photocurable resin. As the energy ray curable resin, the same material as that used for the polishing layer constituent material can be used.

In addition, as the composition of the buffer layer for the polishing pad of the present invention, the compound having rubber elasticity can be any resin with low hysteresis and high compressibility similar to rubber, such as butadiene polymer, isoprene ethylene polymer, styrene-butadiene polymer, styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block polymer, styrene-ethylene-butadiene —Styrene block copolymer, acrylonitrile-butadiene copolymer, polyurethane rubber, epichlorohydrin rubber, chlorinated polyethylene, silicone rubber, polyester-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, polyurethane-based Thermoplastic elastomers, fluorine-based thermoplastic elastomers, etc.

When a plasticizer is mixed with the above cushion layer constituent material, the compressibility can be further increased. The plasticizer used is not particularly limited, such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, dioctyl phthalate , Bis-2-ethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate, tricosyl phthalate, butylbenzyl phthalate phthalate, dicyclohexyl phthalate, tetrahydrophthalate and other phthalates; di-2-ethylhexyl adipate, dioctyl adipate, di Isononyl adipate, diisodecyl adipate, bis(butylene glycol) adipate, di-n-alkyl adipate, di-2-ethylhexyl azelate, dibutyl sebacate , dioctyl sebacate, di-2-ethylhexyl sebacate, dibutyl maleate, bis-2-ethylhexyl maleate, dibutyl fumarate and other aliphatic binary Ester; triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, and other phosphates; chlorinated alkanes, acetyl tributyl citrate, Epoxy plasticizers, polyester plasticizers, etc.

Next, the case where a photocurable resin is used in the manufacturing method of the cushion layer for polishing pads of this invention is demonstrated as an example. In the case of using other resins, the buffer layer can also be produced by the method according to this method.

In the present invention, firstly, a mixture of a polymer, a monomer, and a plasticizer to which additives such as the photoinitiator and the like are added is prepared by melt-mixing, and then molded into a thin plate shape. The melt-mixing method is not particularly limited, and a method in which the temperature is raised to a temperature equal to or higher than Tg (glass transition temperature) of the polymer in a twin-screw extruder to perform melt-mixing can be employed. In addition, the processing method of the thin plate is not necessarily limited, and conventionally known methods can be applied. For example, methods such as roll coating, knife coating, doctor blade coating, blade coating, gravure coating, die coating, inversion coating, spin coating, curtain coating, and spray coating can be used. Alternatively, mold molding may be performed by pouring into a designated mold or the like.

When it is necessary to further increase the compressibility of the thin plate produced by the above method, a pattern is formed by using a conventionally known photolithography method with a light wavelength suitable for the composition, and a desired shape portion is photocured on the thin plate. The uncured part is washed away with a solvent, thereby forming a concavo-convex shape.

When a load is applied to the buffer layer obtained in this way, stress concentrates on the bases of the convex portions of the concave-convex portions formed during patterning. If the protrusions are formed so as to be uniformly dispersed in the surface of the pad, the protrusions will similarly sink in and exhibit a cushioning effect.

Example

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the following examples.

<Evaluation method>

(evaluation of liquidity)

Place a sample of predetermined size, shape, and thickness (a circle with a radius of 5 cm and a thickness of 2 mm) on a horizontal platform, and place it in an environment with a temperature of 20° C. and a humidity of 65%. The diameter of the circle is measured at regular intervals to evaluate the movement of the sample.

(Determination of static friction coefficient and dynamic friction coefficient)

Measurements were performed in accordance with ASTM-D-1894. Specifically, a sample of 50 mm x 80 mm was used, and a commercially available soda glass (transparent plate glass) was used as a target material, and the measurement was performed under the conditions of a load of 4.4 kgf and a tensile speed of 20 cm/min.

(hardness)

(a) When the polishing layer is a single layer

The Shore D hardness was measured according to JIS K6253.

(b) When the polishing layer is composed of a polishing surface layer and a back layer

The abrasive layer after processing was divided equally in the thickness direction with a slicer, and the cut surface and the opposite surface were used as measurement surfaces, and the Shore hardness of the abrasive layer (front surface) and the mounting surface (back surface) were respectively measured according to JIS K6253. The hardness of the surface and the hardness of the back are approximately equal, and the hardness of the intermediate layer (the hardness of the cut portion is lower than that of the cut portion measured at this time) is measured to obtain the hardness difference with the surface layer.

When measuring the hardness difference, change the measurement position to obtain the hardness of 5 points, and obtain the average value of these hardnesses. Then repeat the measurement of the same multiple objects to confirm whether the measured value is accurate. If the measured value is wrong, repeat the measurement of the same object until there is no difference in hardness.

(storage elastic rate)

A portion cut out in a small block (thickness: optional) of 3 mm×40 mm was used as a sample for dynamic viscoelasticity measurement. The correct width and thickness of each cut sheet was measured with a micrometer. In the measurement, a dynamic viscoelasticity spectrometer (manufactured by Iwamoto Seisakusho, now aieis Giken) was used to measure the storage elastic modulus E. The measurement conditions at this time are shown below. The measurement conditions are measurement temperature: 40° C., applied strain: 0.03%, initial load: 20 g, and frequency: 1 Hz. Table 1 shows the storage elastic modulus.

(compression rate, compression recovery rate)

Using a cylindrical indenter with a diameter of 5 mm, T1 to T3 of the polished layer after processing were measured at 25° C. with TMA manufactured by maxsayieis, and obtained from the following formula.

Compression ratio (%)=100(T1—T2)/T1

Compression recovery rate (%)=100(T3—T2)/(T1—T2)

T1: The thickness of the sheet when the stress load of 30Kpa (300g/cm ² ) is maintained for 60 seconds from the no-load state

T2: The thickness of the sheet when the stress load of 180Kpa is maintained for 60 seconds from the state of T1

T3: The thickness of the thin plate when it is placed in a no-load state for 60 seconds from the state of T2, and then maintained for 60 seconds under a 30Kpa stress load.

(Grinding evaluation A)

(grinding speed)

A wafer on which a 500 nm (5000 angstrom) SiO ₂ film was formed on the surface of a silicon single crystal was used as a processing material for evaluation, and the polishing evaluation was performed under the following conditions.

As the polishing device, lapmaster/LM15 (corresponding to Φ4 inches) which is generally used as a test polishing device was used. As the abrasive slurry, cerium oxide (Ce0 ₂ ) sol (manufactured by Nissan Chemical Co., Ltd.) was used. On the grinding head, keep the wafer as the processed material under the adsorption water/standard pad (backing) material (NF200), the grinding pad sample is pasted on the grinding plate (grinding pad support body) and fixed, at a grinding pressure of 20kPa ( 200 g/cm ² ), the relative speed between the grinding head and the grinding plate is 30 m/min, and the grinding slurry supply speed is 110 cm ³ /min, and the grinding operation is carried out for 2 minutes, and the grinding speed is measured.

When evaluating the relationship between the grinding time and the grinding speed, the dressing process by the grinding machine with vapor-deposited diamond abrasive grains was not inserted during the grinding process, and the substances remaining on the surface irregularities of the grinding layer were washed in situ with a brush. , while grinding for a given time, measure the grinding speed.

(uniformity evaluation)

Rmax and Rmin were measured with a stylus meter on 25 polished surfaces of a wafer having a diameter of 101.6 mm (Φ4 inches) after polishing. The value (%) calculated by the formula 100×(Rmax−Rmin)/(Rmax+Rmin) was used as an index for evaluating the uniformity of the entire wafer.

(reproducibility evaluation)

The processed pattern portion was observed with an optical microscope.

(Grinding evaluation B)

As a polishing apparatus, SPP600S (manufactured by Okamoto Industrial Co., Ltd.) was used, and the following polishing characteristics were evaluated. As grinding conditions, a silica slurry (SS12, manufactured by Kaibao Tetsu Co., Ltd.) was added as a slurry at a flow rate of 150 ml/min during the grinding process. The grinding load was 350 g/cm ² , the rotation speed of the grinding base plate was 35 rpm, and the rotation speed of the wafer was 30 rpm.

(grinding speed)

Grind an object with a 1 μm thermal oxide film on an 8-inch silicon wafer under the above-mentioned conditions to about 0.5 μm, and calculate the grinding speed (Angstrom/minute) of the silicon thermal oxide film from the grinding time. The thickness measurement of the oxide film used an interferometric film thickness measurement device (manufactured by Taitaku Electronics Co., Ltd.).

(planarization characteristics)

After depositing a thermal oxide film of 0.5 μm on an 8-inch silicon wafer, a predetermined pattern is formed, and then a 1 μm oxide film is deposited with p-TEOS to produce a patterned wafer with an initial step difference of 0.5 μm. Polishing was carried out under the above-mentioned conditions, and each level difference was measured after polishing to evaluate planarization characteristics. Two steps were measured as planarization characteristics. One of them is a local level difference, which is a level difference in a pattern in which lines having a width of 270 μm are arranged at a pitch of 30 μm, and the level difference after 1 minute is measured. The other is the amount of cutting. In the pattern of lines with a width of 270 μm arranged at a pitch of 30 μm and the pattern of lines with a width of 30 μm arranged at a pitch of 270 μm, the step difference at the upper part of the lines of the above two patterns is measured to be 2000 angstroms or less Cutting amount at a distance of 270μm. A low value of the local level difference indicates that the unevenness of the oxide film generated by the pattern on the wafer is fast in a certain period of time to become flat. In addition, if the cutting amount of the space is small, it means that the cutting amount of the part that is not desired to be cut is small, and the flatness is high.

(Grinding evaluation C)

Wafers in which a 5000 angstrom SiO ₂ film was formed on the surface of single crystal silicon were used as processing materials for evaluation, and the polishing evaluation was performed under the following conditions.

As a polishing apparatus, nanofactor/NF-300 (corresponding to Φ3 inches), which is generally used as a test polishing apparatus, was used. As the polishing slurry, a silica (SiO ₂ ) slurry (manufactured by Fujimi Corporation) was used. On the grinding head, under the condition of absorbing water/standard pad (backing) material (S=R301), the wafer as the processed material is kept, and the grinding pad sample is pasted on the grinding plate (grinding pad support body) to fix it. The grinding operation was performed for 2 minutes under the conditions of a pressure of 20kPa (200g/cm ² ), a relative speed between the grinding head and the grinding plate of 50m/min, and a supply speed of the grinding slurry of 25cc/min, and the grinding speed was measured.

(uniformity evaluation)

Rmax and Rmin were measured with a stylus meter on 14 polished surfaces of a wafer having a diameter of 7.62 cm (Φ3 inches) after polishing. The value (%) calculated by the formula 100×(Rmax−Rmin)/(Rmax+Rmin) was used as an index for evaluating the uniformity of the entire wafer.

(Example 1)

(Embodiment 1-1)

125 g of epoxy acrylate (EX5000 produced by Kyoeisha Chemical Co., Ltd., butanone solvent, solid content 80%), 1 g of benzyl dimethylacetacetal, and 0.1 g of hydroquinone methyl ether were mixed with a kneader, and the mixture was reduced. The solvent was removed under pressure to obtain a solid photocurable composition. This composition was sandwiched between films and extruded with a press at 100° C. and 10 atmospheres to obtain a thin plate-shaped molded body with a thickness of 2 mm. The sheet-shaped molded article is irradiated with ultraviolet rays, and then a film on which a desired pattern is drawn is placed on the opposite side, irradiated with ultraviolet rays, the film is peeled off, rubbed with a brush in a toluene solvent, and developed. The seed was dried at 60° C. for 30 minutes to obtain a polishing pad.

About this polishing pad, polishing evaluation was performed according to the polishing evaluation A method.

(Embodiment 1-2)

Using a kneader, 200 g of polyurethane resin (bylonUR-1400 manufactured by Toyobo Co., Ltd., toluene/butanone (1/1 weight) solvent, solid content 30%), 40 g of trimethylolpropane trimethacrylate, 1 g of benzyldimethylacetophenone and 0.1 g of hydroquinone methyl ether were removed, and a solid photocurable composition was obtained. This composition was sandwiched between films and extruded with a press at 100° C. and 10 atmospheres to obtain a thin plate-shaped molded body with a thickness of 2 mm. The sheet-shaped molded article is irradiated with ultraviolet rays, and then a film on which a desired pattern is drawn is placed on the opposite side, irradiated with ultraviolet rays, and the film is peeled off for development. The seed was dried at 60° C. for 30 minutes to obtain a polishing pad. The following evaluations were performed in the same manner as in Example 1.

(Embodiment 1-3)

145 g of urethane acrylate (UF503LN, produced by Kyoeisha Chemical Co., Ltd., butanone solvent, solid content 70%), 1 g of benzyl dimethylacetacetal, and 0.1 g of hydroquinone methyl ether were stirred and mixed with a kneader, and removed. solvent to obtain a solid photocurable composition. This composition was sandwiched between films and extruded with a press at 100° C. and 10 atmospheres to obtain a thin plate-shaped molded body with a thickness of 2 mm. The sheet-shaped molded article is irradiated with ultraviolet rays for a certain period of time, and then a film on which a desired pattern is drawn is placed on the opposite side, irradiated with ultraviolet rays, and the film is peeled off for development. The seed was dried at 60° C. for 30 minutes to obtain a polishing pad. The following evaluations were performed in the same manner as in Example 1.

(Embodiment 1-4)

258 g of polyurethane resin (bylonUR-8400 manufactured by Toyobo Co., Ltd., toluene/butanone (1/1 weight) solvent, 30% of solid content) and 22.5 g of 1,6-hexanediol diacrylate were stirred and mixed with a kneader. , 1 g of benzyldimethylacetophenone and 0.1 g of hydroquinone methyl ether, and the solvent was removed under reduced pressure to obtain a solid photocurable composition. This composition was sandwiched between films and extruded with a press at 100° C. and 10 atmospheres to obtain a thin plate-shaped molded body with a thickness of 2 mm. Ultraviolet rays are irradiated to this sheet-shaped molded body, and then a film on which a desired pattern is drawn is placed on the opposite side, irradiated with ultraviolet rays, and the film is peeled off for development. The seed was dried at 60° C. for 30 minutes to obtain a polishing pad. The following evaluations were performed in the same manner as in Example 1-1.

(Comparative example 1-1)

100 g of liquid urethane acrylate and 1 g of benzyldimethylacetophenone were stirred and mixed to obtain a liquid photocurable composition. This composition is poured into a mold of a predetermined size and shape to obtain a sheet-shaped molded body of a predetermined thickness. Ultraviolet rays are irradiated to this sheet-shaped molded body, and then a film on which a desired pattern is drawn is placed on the opposite side, irradiated with ultraviolet rays, and the film is peeled off for development. The seed was dried at 60° C. for 30 minutes to obtain a polishing pad.

(Comparative example 1-2)

As the polishing pad, IC1000 A21 (manufactured by Rodieru Co., Ltd.), which is a foamed polyurethane polishing pad, was used. The polishing rate was evaluated under the same apparatus and polishing conditions as in Example 1-1. And the grinding rate was measured. For the evaluation of the grinding time and the grinding speed, add the correction process carried out by the grinding machine carried out by evaporation of diamond abrasive grains in the grinding and do not add under the situation of the correction process, carry out respectively, grind the predetermined time respectively, and measure the grinding speed.

Table 1-1 shows the results of investigation of the fluidity of each sample before light irradiation. From the results, it can be seen that the solid thin-plate molded article has no fluidity. From this, it can be seen that the film thickness change with time decreases.

Table 1-1

After 1 hour After 3 hours Example 1-1 no change no change Embodiment 1-2 no change no change Embodiment 1-3 no change no change Comparative example 1-1 10.5cm 11.9cm

The following shows the relationship between various surface patterns prepared according to Example 1-1 and the coefficient of friction.

Table 1-2

surface pattern Wafer detachment Static friction coefficient dynamic friction coefficient no pattern have 1.49 1.27 perforation none 1.37 1.23 XY grid none 1.14 1.01 concentric circles none 1.10 0.98 cylinder none 0.88 0.72 Combination of cylinder and perforation none 0.51 0.34

Perforation: hole diameter 1.6mm, number of holes 4/cm ²

XY grid: groove width 2.0mm, groove depth: 0.6mm, groove spacing 15.0mm

Concentric circles: groove width 0.3mm, groove depth: 0.4mm, groove spacing 1.5mm

Cylinder: diameter 0.5mm, height 5mm

The results of the polishing speed of each sample are shown below. The measurement was carried out according to grinding evaluation method A.

Table 1-3

Grinding speed (Angstrom/min) Example 1-1 1160 Embodiment 1-2 1210 Embodiment 1-3 1290 Comparative example 1-1 1000

The surface patterns of Examples 1-1 to 1-3 used a composite type of cylinders and concentric circles.

Tables 1-4 show the relationship between the polishing speed and the polishing time when no dressing step is added to the polishing for Example 1-1 (the surface pattern is a composite type of cylinders and concentric circles).

Table 1-4

From the above results, it can be seen that the grinding speed of the present invention is stable without the trimming process, and maintains a stable grinding speed compared with the case of adding the dressing process in Comparative Example 1-2.

(Embodiment 1-4)

On the non-concave-convex surface of the polishing pad used in Example 1-1 (the surface pattern is concentric circles), a double-sided adhesive tape with a thickness of 50 μm polyethylene terephthalate as a core material was laminated and impregnated with amino A nonwoven fabric of ethyl formate (SUBA400 manufactured by Rodeirnita Co., Ltd.). As a result of observing the interference light on the surface with the naked eye, compared with Example 1-1, partial polishing unevenness of the wafer was further improved, and almost no polishing unevenness was observed. In addition, as a result of measuring surface irregularities with a stylus type surface roughness measuring instrument, the flatness is further improved compared with Example 1-1.

(Example 2)

(Manufacture of polishing pad sample 2-1)

Utilize a homogenizer to stir 1,9-nonanediol dimethacrylate (1,9-NDH produced by Kyoeisha Chemical Co., Ltd.), 30 parts by weight, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer ( A mixture of 70 parts by weight of UA-306H manufactured by Kyoeisha Chemical Co., Ltd. and 1 part by weight of benzyl dimethylacetophenone (irugakyua651 manufactured by Tsibagayigi Co., Ltd.) was applied by a coater for 10 minutes and allowed to It is sandwiched between PET films coated with a release agent to produce a thin plate-shaped molded body. Irradiate a certain amount of ultraviolet light to the opposite side of the grinding surface, place a mask material with a grid-like pattern with a groove width of 2 mm and a pitch width of 1.5 cm on the thin plate, on the opposite surface to the above, and irradiate ultraviolet light to cure and cure. Afterwards, the PET film was peeled off in a developing step in which the unexposed portion was removed with a developing solution, followed by drying to obtain a polishing pad sample 1-1. On the polishing pad, the unevenness is faithfully reproduced in the pattern, and the operability is greatly shortened.

(Preparation of polishing pad samples 2-2 to 2-1)

Polishing pads 2-2 to 2-12 were prepared in the same manner as polishing pad sample 2-1. The curable composition and uneven pattern used are shown in Table 2-1. The ratio is expressed by weight ratio. The raw materials used are as follows.

1,6-Hexanediol diacrylate: 1,6-HX (Kyoto Chemical)

Glycerin dimethacrylate hexamethylene diisocyanate prepolymer: UA-101H (Kyoto Chemical)

Aliphatic urethane acrylate: Actilane 270 (ACROS CHEMICALS)

Aromatic urethane acrylate: Actilane 167 (ACROS CHEMICALS)

Low-butadiene acrylate: BAC-45 (Osaka Organic Chemicals).

(Preparation of grinding pad samples 2-13~2-15)

Using a kneader, 125 g of epoxy acrylate EX5000 (manufactured by Kyoeisha Chemical Co., Ltd., butanone solvent, solid content 80%), 1 g of benzyl dimethylacetacetal, and 0.1 g of hydroquinone methyl ether were mixed and stirred, and The solvent was removed under pressure to obtain a solid photocurable composition. This composition was sandwiched between films and extruded with a press at 100° C. and 10 atmospheres to obtain a thin plate-shaped molded body with a thickness of 2 mm. Ultraviolet rays are irradiated to this thin plate-shaped molded body; then, a mask film with an XY grid pattern drawn on the opposite side is placed, and ultraviolet rays are irradiated from the back side to peel off the film, rub with a brush in toluene solvent, and develop. The samples were dried at 60° C. for 30 minutes to obtain polishing pad samples 2-13 having concavities and convexities in an XY grid pattern on the surface.

By changing the pattern of the mask, polishing pad sample 2-14 (concentric circle pattern) and polishing pad sample 2-15 (network pattern) were obtained. The groove width, pitch width, diameter, and depth of each pattern are the same as those of sample liners 2-1 to 2-3.

(Manufacturing of grinding pad samples 2-16 to 2-18)

Urethane resin bayilon UR-1400 (manufactured by Toyobo Co., Ltd., toluene/butanone (1/1 weight ratio) solution, solid content 30%) 200 g, trimethylolpropane trimethacrylate 40 g, benzyl diformaldehyde 1 g of acetoacetate and 0.1 g of hydroquinone methyl ether were exactly the same as the polishing pad samples 2-13 to 2-15 to obtain a polishing pad sample 2-16 having concavo-convex patterns with XY lattice patterns on the surface, and a concentric circle pattern The embossed polishing pad sample 2-17, and the embossed polishing pad sample 2-18 with a network pattern.

(Manufacturing of polishing pad samples 2-19 to 2-21)

Urethane resin bayilonUR-8400- (manufactured by Toyobo Co., Ltd., toluene/butanone (1/1 weight ratio) solution, solid content 30%) 258 g, 1,6-hexanediol diacrylate 22.5 g, benzyl Diformaldehyde ketone ketone 1g and hydroquinone methyl ether 0.1g are exactly the same as polishing pad samples 2-13 to 2-15 to obtain polishing pad sample 19 with XY grid-shaped pattern concavities and convexities on the surface, and concentric circle pattern concavo-convexes. The polishing pad sample 2-20, and the polishing pad sample 2-21 with network-like pattern concavo-convex.

(Manufacture of polishing pad sample 2-22)

Use a carving knife to carve a grid-like pattern with a groove width of 2mm, a spacing width of 1.5cm, and a depth of 0.6mm on the surface of the foamed polyurethane resin, as the polishing pad sample 2-22, which will require a lot of operating time. The deviation is also large.

(Manufacturing of polishing pad samples 2-23)

Polishing pad sample 2-23 was produced using the same sheet-shaped molded body as in polishing pad samples 2-13 to 2-15, without forming a concavo-convex pattern.

(evaluate)

According to the evaluation method A, polishing evaluation was performed on the polishing pad samples 2-1 to 2-22, and the results are shown in Table 2-2 and Table 2-3. In Table 2-2 and Table 2-3, the compression rate of the polishing pad, the measurement results of the compression recovery rate, and the workability of forming unevenness and the reproducibility of the pattern are shown together.

Table 2-4 shows the results of measuring the coefficient of static friction and the coefficient of dynamic friction of the polishing pads of the polishing pad samples 2-13 to 2-15, and the polishing pad sample 2-23 without the concave-convex pattern.

Table 2-1

Polishing Pad Sample Composition of curable composition Embossed pattern 1 1,9-nonanediol dimethacrylate 30 parts pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer 70 parts benzyl dimethyl ketal ketone 1 part Groove width 2mm pitch width 1.5cm depth 0.6mmXY lattice groove 2 ditto Groove width 0.3mm spacing width 1.5mm depth 0.4mm concentric circular groove 3 ditto Diameter: 500μm groove width 900μm depth 0.4mm network convex part 4 1,9-nonanediol dimethacrylate 30 parts aliphatic urethane acrylate 70 parts benzyl dimethyl ketal ketone 1 part Groove width 2mm pitch width 1.5cm depth 0.4mmXY lattice groove 5 ditto Groove width 0.3mm spacing width 1.5mm depth 0.4mm concentric circular groove 6 ditto Groove width 500μm pitch width 900μm depth 0.4mm network convex part 7 1,9-nonanediol dimethacrylate 40 parts of aromatic urethane acrylate 60 parts of benzyl dimethyl ketal ketone 1 part Groove width 2mm pitch width 1.5cm depth 0.4mmXY lattice groove 8 ditto Groove width 0.3mm spacing width 1.5mm depth 0.4mm concentric circular groove 9 ditto Groove width 500μm pitch width 900μm depth 0.4mm network convex part 10 1,9-Nanediol Dimethacrylate 10 parts Low Butadiene Diacrylate 10 parts Aromatic Urethane Acrylate 80 parts Benzyl Diformaldehyde Ketoketone 1 part Groove width 2mm pitch width 1.5cm depth 0.4mmXY lattice groove 11 ditto Groove width 0.3mm spacing width 1.5mm depth 0.4mm concentric circular groove 12 ditto Groove width 500μm pitch width 900μm depth 0.4mm network convex part

The results in Table 2-2 and Table 2-3 show that the polishing pad of the present invention has good reproducibility, so the unevenness of the quality caused by the individual in the concave-convex processing is not small, the pattern is easy to change, the operability is excellent, and the uniformity in polishing is excellent. excellent. And there will be no problem of detachment during the grinding process.

Table 2-4

Polishing Pad Sample pattern Static friction coefficient dynamic friction coefficient Wafer detachment 2-13 X Y 1.14 1.01 none 2-14 concentric circles 1.10 0.98 none 2-15 network 0.88 0.72 none 2-23 none 1.49 1.27 have

[Example 3]

[Making of polishing pad]

(grinding pad sample 3-1)

Utilize homogenizer to stir 60 weights of low-butadiene diol diacrylate (BAC-45 manufactured by Osaka Organic Chemical Co., Ltd.) and 1,9-nonanediol dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) A mixture of 40 parts by weight of 1,9-NDH) and 1 part by weight of benzyl dimethylacetophenone (irugakyua651 manufactured by Tsibagayigi Co., Ltd.) was applied for 10 minutes by using a coater to sandwich the coating release agent A non-crosslinked sheet with a thickness of 2 mm was prepared from a PET film. This sample was cured by irradiating ultraviolet light from the surface opposite to the polished surface by a conventional method. After curing, the PET film was peeled off to obtain a polishing pad sample 3-1.

(grinding pad sample 3-2)

40 parts by weight of 1,9-nonanediol dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.), 40 parts by weight of aliphatic urethane acrylate (manufactured by ACROS CHEMICALS, Actilane270) and 60 parts by weight were stirred using a homogenizer. A mixture of parts by weight and 1 part by weight of benzyldimethylacetacetate (irugakyua651 manufactured by Tsibagayigi Co., Ltd.) was applied by a coater for 10 minutes, and sandwiched between PET films coated with a release agent. Uncrosslinked sheet with a thickness of 2 mm. This sample was cured by irradiating ultraviolet light in the same manner as polishing pad 3-1. After curing, the PET film was peeled off to obtain a polishing pad sample 3-2.

(grinding pad sample 3-3)

Stir 50 parts by weight of bisphenol A epoxy resin (cipicoto 154 manufactured by Yukasiel Epoxy Resin Co., Ltd.) and bisphenol A epoxy resin (eipicoto 871 manufactured by Yukasiel Epoxy Resin Co., Ltd.) with a homogenizer A mixture of 60 parts by weight and 1 part by weight of 2-methylimidazole was coated for 10 minutes with a coater so that it was sandwiched between PET films coated with a release agent to obtain a non-crosslinked sheet with a thickness of 2 mm. The sample was cured by applying heat at 150° C. to the upper portion and 90° C. to the lower portion. After curing, the PET film was peeled off to obtain polishing pad sample 3-3.

(grinding pad samples 3-4)

Utilize a homogenizer to stir 60 parts by weight of low-butadiene diol diacrylate (BAC-45 manufactured by Osaka Organic Chemicals Co., Ltd.) and 1,9-nonanediol dimethacrylate (Kyoeisha Chemical Co., Ltd. Prepare a mixture of 40 parts by weight of 1,9-NDH) and 1 part by weight of benzyl dimethylacetophenone (irugakyua651 manufactured by Tsibagayigi Co., Ltd.) for 10 minutes, and then apply it with a coater, and sandwich it between the coating Release agent for PET film. The exposed surface is irradiated with ultraviolet light from the opposite side of the polished surface of the sample, and then a negative-type film with a diameter of 50 μm is placed on the polished surface side, irradiated with ultraviolet light and cured, and after curing, the PET film is peeled off, developed with toluene, and dried. , to obtain polishing pad samples 3-4 in which cylinders with a diameter of 50 μm are arranged on the polishing surface.

(grinding pad samples 3-5)

Utilize a homogenizer to stir 60 parts by weight of low-butadiene diol diacrylate (BAC-45 manufactured by Osaka Organic Chemicals Co., Ltd.) and 1,9-nonanediol dimethacrylate (Kyoeisha Chemical Co., Ltd. Prepare a mixture of 40 parts by weight of 1,9-NDH) and 1 part by weight of benzyldimethylacetophenone (irugakyua651 manufactured by Tsibagayigi Co., Ltd.) for 10 minutes, apply it with a coater, and make it sandwiched between the coating and peel off. molded PET film. The exposed surface is irradiated with ultraviolet light from the opposite side of the polished surface of the sample, and then a negative film representing an XY groove is placed on the polished surface side, irradiated with ultraviolet light to cure, and after curing, the PET film is peeled off, developed with toluene, and dried to obtain a polished surface. Pad samples 3-5 with XY grooves on the face.

(grinding pad samples 3-6, 7)

A mixture of 100 parts by weight of Actilane 200 (manufactured by AKROS CHEMICALS) and 1 part by weight of benzyl dimethylacetophenone (irugakyua651 manufactured by Tsibagayigi Co., Ltd.) was stirred with a homogenizer for 10 minutes, and coated with a coater to make it A non-crosslinked sheet having a thickness of 2 mm was produced by sandwiching a release agent-coated PET film.

The non-crosslinked thin plate sample was cured by irradiating ultraviolet light from the surface side of the polishing layer by a conventional method. After curing, the PET film was peeled off to obtain polishing pad samples 3-6.

And from the surface opposite to the grinding surface of the uncrosslinked thin plate sample, ultraviolet light is irradiated to the exposure surface, and then a negative film with circles with a diameter of 50 μm is placed on the grinding surface side, irradiated with ultraviolet light to cure, and after curing The PET film was peeled off, developed with toluene, and dried to obtain polishing pad samples 3-7 in which columns with a diameter of 50 μm were arranged on the polishing surface.

(grinding pad samples 3-8)

200 g of polyurethane resin bylonUR-8400 (manufactured by Toyobo Co., Ltd., toluene/butanone (1/1 weight ratio) solution, solid content 30%) and 40 g of trimethylolpropane trimethacrylate were stirred and mixed with a kneader. , 1 g of benzyldimethylacetophenone and 0.1 g of hydroquinone methyl ether, and the solvent was removed to obtain a solid photocurable composition. This composition was sandwiched between films and pressed using a press at 100° C. and 10 atmospheres to obtain a thin plate-shaped molded body with a thickness of 2 mm. Ultraviolet light is irradiated from the exposed surface of the thin plate-shaped sample opposite to the grinding surface, and then a negative film with a diameter of 50 μm is placed on the grinding surface side, irradiated with ultraviolet light and cured, and the PET film is peeled off after curing. Toluene was used for development and drying to obtain polishing pad samples 3-8 in which columns with a diameter of 50 μm were arranged on the polishing surface.

(grinding pad samples 3-9)

Using a kneader, 258 g of polyurethane resin bylonUR-8400 (manufactured by Toyobo Co., Ltd., toluene/butanone (1/1 weight ratio) solution, solid content 30%), 1,6-hexanediol dimethyl 22.5 g of acrylate, 1 g of benzyldimethylacetophenone, and 0.1 g of hydroquinone methyl ether were removed, and a solid photocurable composition was obtained. This composition was sandwiched between films and pressed using a press at 100° C. and 10 atmospheres to obtain a thin plate-shaped molded body with a thickness of 2 mm. Ultraviolet light was irradiated from the exposed surface of the thin plate-shaped sample opposite to the polished surface, and then a negative film showing XY grooves was placed on the polished surface side, and cured by irradiation with ultraviolet light. After curing, the PET film was peeled off, developed with toluene, and dried to obtain polishing pad samples 3-9 with XY grooves on the polishing surface.

(grinding pad samples 3-10)

IC-1000A21, which is a commercially available polyurethane polishing pad, was used as polishing pad sample 3-10.

Table 3 shows the evaluation results of these pads. The evaluation of the polishing characteristics was performed according to the polishing evaluation method A.

[Example 4]

(Embodiment 4-1)

(grinding layer)

As a polishing layer forming material, a photosensitive resin produced as follows was used. 258 g of polyurethane resin (bylonUR-8400 manufactured by Toyobo Co., Ltd., toluene/butanone (1/1 weight ratio), solid content 30% by weight) and 1,6-hexanediol dimethacrylic acid were stirred and mixed with a kneader. 22.5 g of ester, 1 g of benzyldimethylacetophenone, and 0.1 g of hydroquinone methyl ether were removed, and a solid photocurable composition was obtained. This composition was sandwiched between films and pressed using a press at 100° C. and 10 atmospheres to obtain a thin plate-shaped molded body with a thickness of 1.27 mm. The sheet-shaped molded article is irradiated with ultraviolet rays for a certain period of time, and then a film on which a desired pattern is drawn is placed on the opposite side, irradiated with ultraviolet rays, and the film is peeled off for development. It dried at 60 degreeC for 30 minutes, and produced the polishing layer (non-cavity). A pattern film having XY grid grooves (groove width: 2.0 mm, groove depth: 0.6 mm, groove pitch: 15.0 mm) was used as the surface shape of the polished surface of the polishing layer. A 60 cm diameter circle was cut out of it for use in the abrasive layer. The storage elastic modulus of the obtained polishing layer was 350 Mpa, and the tensile elastic modulus was 860 Mpa.

(The buffer layer)

I use polyethylene foam (ドレイビフィフ made by Torei Corporation) (thickness 1.27mm, storage modulus of elasticity 7.9Mpa) which performed surface polishing, corona treatment.

(grinding pad)

Attach a double-sided tape (double tack tape, manufactured by Sekisui Chemical Co., Ltd., manufactured by Sekisui Chemical Co., Ltd.) to the surface of the abrasive layer opposite to the abrasive surface, and then attach the buffer layer. Furthermore, a double-sided adhesive tape was attached to the surface of the buffer layer opposite to the polishing layer to obtain a polishing pad.

(Embodiment 4-2)

In Example 4-1 (abrasive layer), in addition to being used as an abrasive layer forming material, a polyurethane resin (bylonUR-8300 produced by Toyobo Co., Ltd., solvent: toluene/butanone (1/1 wt. Photocuring of a solid with solvent removed (ratio) solution, 258 g of solid content 30%), 22.5 g of trimethylolpropane trimethacrylate, 1 g of benzyl dimethylacetophenone, and 0.1 g of hydroquinone methyl ether A polishing pad was produced in the same manner as in Example 4-1 except for the abrasive composition. The storage elastic modulus of the obtained polishing layer was 200 Mpa, and the tensile elastic modulus was 690 Mpa.

(Embodiment 4-3)

In Example 4-1 (abrasive layer), in addition to being used as a abrasive layer forming material, a polyurethane sheet (polyether-based urethane prepolymer (made by uniloyiyaru, ajipuran L-325)) and a curing agent ( 4,4'-methylene-bis[2-chloroaniline])) to make the grinding layer (non-cavity) (thickness of the grinding layer is 1.27mm), and use an external tool to make the surface of the grinding surface side of the grinding layer Shaped into XY grid grooves (groove width: 2.0mm, groove depth: 0.6mm, groove pitch: 15.0mm) and cut into circles with a diameter of 60cm, a polishing pad was produced in the same manner as in Example 4-1. . The storage elastic modulus of the obtained abrasive layer was 700 Mpa, and the tensile elastic modulus was 1050 Mpa.

(Embodiment 4-4)

In Example 4-1 (abrasive layer), in addition to being used as an abrasive layer forming material, a polyester sheet (polyethylene terephthalate) formed by sheet molding was used to make an abrasive layer (non-cavity) (abrasive layer thickness 1.27mm), and use an external tool to make the surface shape of the abrasive side of the abrasive layer into an XY grid groove (groove width: 2.0mm, groove depth: 0.6mm, groove pitch: 15.0mm), and cut it into diameter A polishing pad was produced in the same manner as in Example 4-1 except that the circle was 60 cm. The storage elastic modulus of the obtained abrasive layer was 795 Mpa, and the tensile elastic modulus was 1200 Mpa.

(Comparative example 4-1)

In the (polishing layer) of Example 4-1, in addition to using foamed polyurethane (IC1000, manufactured by Rodriru Co., Ltd.) Tool processing makes the surface shape of the grinding surface side of the grinding layer into an XY grid groove (groove width: 2.0mm, groove depth: 0.6mm, groove pitch: 15.0mm), and cut it out of a circle with a diameter of 60cm, and implement Example 4-1 produced a polishing pad in the same manner. The storage elastic modulus of the obtained abrasive layer was 190 Mpa, and the tensile elastic modulus was 200 Mpa.

For the polishing pads obtained in Examples and Comparative Examples, the polishing speed and planarization characteristics were evaluated according to the polishing evaluation method (B). The results are shown in Table 4.

Table 4

Storage elastic modulus of grinding layer (Mpa) Grinding speed (Angstrom/min) Local step difference (Angstrom) 270μm pitch cutting amount (Angstrom) Embodiment 4-1 350 1580 1100 500 Embodiment 4-2 200 2190 400 1500 Embodiment 4-3 700 1800 800 1400 Embodiment 4-4 795 1350 1100 1300 Comparative example 4-1 190 2200 1300 4600

From the results shown in Table 4-1, it can be seen that in the polishing pad with the polishing layer and the cushioning layer, the storage elastic modulus of the polishing layer is 200Mpa, and the use of a polishing pad with a storage elastic modulus of the cushioning layer lower than that of the polishing layer can improve its flatness. characteristics.

(Sample 6-1)

Mix 84 parts by weight of styrene-butadiene copolymer (manufactured by JSR, SBR1507) as a polymer, 10 parts by weight of dodecyl methacrylate as a monomer, and benzyl dimethylformaldehyde acetal as a photoinitiator 1 part by weight of acetone and 5 parts by weight of liquid isoprene as a plasticizer were melt-mixed with a twin-screw extruder, and then extruded through a T-die. The sheet was sandwiched between a PET film with a thickness of 100 μm, pressed with a roll to a total thickness of 2 mm, and formed into an uncured buffer sheet.

Both sides of this uncured buffer sheet were irradiated with ultraviolet rays to cure the entire surface, and then the PET film was peeled off to obtain sample 6-1.

(Sample 6-2)

UV light was irradiated from one side of the uncured buffer sheet obtained in the production process of sample 6-1, and then the PET on the other side was peeled off, and a screened negative film (negative) (diameter of light transmission part 0.6 mm, center pitch of dots) was placed on it. 1.2mm), UV rays are irradiated from the negative side. Immerse the irradiated buffer sheet in a mixed solvent of toluene/butanone (1/1 weight), and rub it with a nylon brush to wash away the uncured part. The obtained uneven buffer sheet was dried in an oven at 60° C., and cured by irradiating ultraviolet rays to the uneven surface.

The PET sheet on the back was peeled off to obtain sample 6-2. The depth of the concave portion of Sample 6-2 was 0.6 mm.

(Sample 6-3)

A commercially available nonwoven fabric type cushioning layer, SUBA400 (manufactured by Rodieru), was used as sample 6-3.

The characteristic values of the samples are shown below.

Table 6-1

Shore A Compression ratio(%) Compression recovery rate (%) Sample 6-1 17 20.4 92.9 Sample 6-2 18 26.8 90.2 Sample 6-3 52 8.0 88.0

IC-1000 (manufactured by Rodieru Co., Ltd.), which is a commercially available polyurethane polishing pad, was laminated on each sample, and polishing characteristics were evaluated according to polishing evaluation method C. The following table shows the results.

Table 6-2

The buffer layer Grinding speed (Angstrom/min) in-plane uniformity Sample 6-1 sample 192 2.2 Sample 6-2 sample 188 2.0 Sample 6-3 sample 100 3.5

<(II) Slurry-free polishing pad>

Examples of the slurry-free polishing pad of the present invention will be described below.

As the resin forming the polishing layer of the present invention, for example, one having an ion group content in the range of 20 to 1500 eq/ton can be used without particular limitation. The resin may be linear or branched, and may have a structure in which side chains are added to the main chain. The ionic group may exist in either the main chain or the side chain as long as it is contained in the resin.

The ionic groups that the resin has include carboxyl groups, sulfonic acid groups, sulfate ester groups, phosphoric acid groups, or anionic groups such as groups of their salts (hydrogen salts, metal salts, ammonium salts), and/or primary groups. A cationic group such as an amine or tertiary amino group. Among these ionic groups, it is desirable to use a carboxyl group, an ammonium carboxylate group, a sulfonic acid group, an alkali metal sulfonic acid group, or the like.

As the aforementioned resin, polyester-based resins, polyurethane-based resins, acrylic resins, polyester-urethane resins, and the like are preferable. Among them, polyester-based resins are particularly preferable. The polyester-based resin may be modified with urethane, acrylic acid, or the like.

Hereinafter, polyester-based resins will be described as representative examples of resins having ionic groups in the above-mentioned range.

(polyester resin)

Polyester resins are basically obtained by polycondensation of polybasic acids and polyhydric alcohols.

Polycarboxylic acids are mainly composed of dicarboxylic acids and their anhydrides. Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 1,5-naphthalene dicarboxylic acid, and bisphenyl dicarboxylic acid. The usage-amount of an aromatic dicarboxylic acid is 40 mol% or more of polyhydric carboxylic acid components, More preferably, it is 60 mol% or more. Among the aromatic dicarboxylic acids, terephthalic acid and phthalic acid are preferable, and the content of these in the aromatic dicarboxylic acid is preferably 50 mol % or more.

Examples of dicarboxylic acids other than aromatic dicarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid; 1,4-cyclohexane Alicyclic dicarboxylic acids such as dicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, dimer acid, trimer acid, tetramer acid, and the like.

In addition, examples of dicarboxylic acids include fumaric acid, maleic acid, itaconic acid, citraconic acid, hexahydrophthalic acid, tetrahydrophthalic acid, 2,5-norbornane dicarboxylic acid, Aliphatic or alicyclic dicarboxylic acids containing unsaturated double bonds, such as carboxylic acids or their anhydrides.

As the polyvalent carboxylic acid component, tricarboxylic acids such as trimellitic acid, trimellitic acid, and pyromellitic acid, tetracarboxylic acids, and the like can be used as needed.

Examples of the polyol component in the present invention include ethylene glycol, propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, Diol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, spirocyclodiol, 1,4-phenylene Ethylene glycol, ethylene oxide adduct of 1,4-phenylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, tricyclodecane dimethanol, dimer glycol, hydrogenation Diols such as dimer glycol, ethylene oxide adducts and propylene oxide adducts of bisphenol A, etc., ethylene oxide adducts and propylene oxide adducts of hydrogenated bisphenol A, etc. Glycols.

In addition, as the polyhydric alcohol, trihydric alcohols such as trimethylolethane, trimethylolpropane, and glycerin, and tetrahydric alcohols such as pentaerythritol may be mentioned as necessary.

As the polyol, a polyol component containing an unsaturated double bond such as glycerin monoallyl ether, trimethylolpropane-allyl ether, pentaerythritol-allyl ether, or the like can be used.

Aromatic hydroxydicarboxylic acids such as p-hydroxybenzoic acid and p-(hydroxyethoxy)benzoic acid can be used for the polyester resin in addition to the above-mentioned polyvalent carboxylic acids and polyhydric alcohols.

The number average molecular weight of the polyester resin is 3,000 to 100,000, more preferably 4,000 to 30,000.

(Introduction of ion groups)

The method for introducing ionic groups into the resin is not particularly limited. The method of introducing an ionic group into a polyester resin may, for example, be a method of using a polyvalent carboxylic acid and/or a polyhydric alcohol having an ionic group that does not react with a carboxyl group or a hydroxyl group when polycondensing a polyester. Such components include, for example, sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5[ Sulfonic acid group-containing polycarboxylic acid compounds such as 4-sulfophenoxy]isophthalic acid, and metal salts thereof. In addition, monocarboxylic acid compounds containing sulfonic acid groups such as sulfobenzoic acid and metal salts thereof can be used, whereby ionic groups can be introduced into polymer terminals.

When introducing an ionic group into a polyester resin, the polyester obtained by condensation of a polycarboxylic acid and a polyhydric alcohol may be used as a main skeleton, and a side chain having an ionic group may be introduced into the skeleton. The method of introducing a side chain having an ionic group can be, for example, using polycarboxylic acid and/or polyhydric alcohol containing a polymerizable unsaturated double bond, introducing a double bond into polyester, and graft-polymerizing a side chain having an ionic group on it. A method of radically polymerizing monomers. As the radically polymerizable monomer, those having the illustrated ionic groups can be used without particular limitation. The radically polymerizable monomer is not limited to a substance having the above-mentioned ionic group, and a nonionic substance may be used in combination. In addition, the ratio of the main chain and side chains of the polyester resin is not particularly limited, but it is desirable that the main chain/branch chain is in the range of 40/60 to 95/5 in terms of weight ratio.

In addition to the above-mentioned method, by adjusting the carboxyl group remaining at the terminal of the polyester resin, a polyester resin having an ionic group content in the above-mentioned range can be prepared. For example, at the end of the polymerization of polyester resin, trimellitic anhydride, pyromellitic dianhydride, phthalic anhydride and other polyvalent carboxylic anhydrides of more than 3 yuan are added to introduce many carboxyl groups to the end of the resin, and the above-mentioned ionic groups can be produced. resin.

Anionic groups such as carboxyl groups and sulfonic acid groups introduced into polyester resins can be used as ionic groups after being neutralized with ammonia, alkali metals, amines, etc. after post-treatment. Examples of metal salts include salts such as Li, Na, K, Mg, Ca, Cu, and Fe, and K salts are particularly preferable.

The resin having the ionic group of the present invention may be used alone or in combination of two or more as necessary. In addition, the resin of the present invention may be used in combination with a resin serving as a curing agent in a molten state or a solution state. For example, a polyester-based resin may be mixed with an amine resin, an epoxy resin, an isocyanate compound, or the like, and may be partially reacted with these.

(Preparation method of water dispersion)

The resin having ionic groups of the present invention has ionic groups in the range of 20 to 1000 eq/ton, so it has water dispersibility, and can be made into a microscopic water dispersion by self-emulsification. The above-mentioned ionic groups are necessary to exhibit the solubility and water dispersibility of the resin. The particle diameter of the microdispersion is ideally 0.01-1 μm.

As a specific method of self-emulsification, in the case of a resin (polyester resin) having a carboxyl group, a sulfonic acid group, a sulfate group, or a phosphoric acid group as an ionic group, (1) dissolving the resin in a water-soluble organic compound , (2) add neutralized cations, (3) add water, (4) use azeotropy, dialysis, etc. to remove the order of water-soluble organic compounds.

Resins (polyester-based resins) having anionic groups such as carboxyl groups, sulfonic acid groups, sulfate ester groups, phosphate groups (metal salts, ammonium salts) or cationic groups such as primary or tertiary amino groups as ionic groups In the case of resin), the order of (1) dissolving the resin in the water-soluble organic compound, (2) adding water, and (3) removing the water-soluble organic compound by azeotropy, dialysis, etc. can be used. When self-emulsifying these, an emulsifier, surfactant, etc. may be added together.

As the water-soluble organic compound, a water-soluble solvent having a relatively low boiling point such as methanol, ethanol, propanol, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, butyl cellosolve, and ethyl cellosolve can be preferably used.

As the cation supply source for neutralization, alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, ammonia, triethylamine, monoethanolamine, diethanolamine, triethanolamine, dimethyl Amines such as base ethanolamine, diethylethanolamine, monomethyldiethanolamine, monomethylethanolamine, isophorone, amine alcohols, cyclic amines, etc.

As the resin that forms the abrasive layer of the present invention, for example, a polyester whose main chain is the content of aromatic dicarboxylic acid in the total carboxylic acid component is 60 mol% or more, or the polyester component can be used as the main The constituent is polyester polyurethane, and the side chain is a polymer of radically polymerizable monomers containing hydrophilic functional groups.

As the conditions for the above-mentioned side chains, polymers of radical polymerizable monomers whose side chains satisfy the following main conditions (1) to (2) are desirable.

i.e. the sidechain is

(1) In the polymer of the radical polymerizable monomer constituting the side chain, the weight sum of the electron-accepting monomer having an e value of 0.9 or more and the electron-donating monomer having an e value of -0.6 or less in the Q-e value is at least Accounting for 50% by weight of the total radically polymerizable monomers.

(2) In the polymer of the radically polymerizable monomer constituting the side chain, the aromatic radically polymerizable monomer accounts for at least 10% by weight of the total radically polymerizable monomers.

The composition of the radically polymerizable monomers used in the above-mentioned side chains is mainly composed of the following monomers as the necessary radically polymerizable monomers, that is, the e value of the Q-e value proposed by Alfrey-Price is 0.9 or more, preferably 1.0 or more, more preferably 1.5 or more radically polymerizable monomers, and e-values of -0.6 or less, preferably -0.7 or less, more preferably -0.8 or less monomers.

When the e value is a large negative value, it indicates a substituent having a strong electron-donating property, and because electrons irrelevant to the bond existing in the unsaturated bond part exist in excess, it indicates the charge of the double bond and the free radical generated therefrom biased toward negative. Conversely, when the e value is a large positive value, it indicates a substituent having a strong charge-absorbing property, and because electrons not interfering with the bond are insufficient, it indicates that the charge of the double bond and the radical generated therefrom tends to be positive. When copolymerizing a radically polymerizable monomer, if a radically polymerizable monomer having an electron-donating substituent, that is, a monomer having a large negative e value and a radically polymerizable monomer having an electron-withdrawing substituent are combined That is, monomers with a very large positive value such as monomers with opposite electronic states, monomers that are easy to add to any free radicals generated during the polymerization process, are all monomers with opposite positive and negative e values, and This tendency becomes remarkable when the difference in e-value is large. As described above, by utilizing the fact that monomers with greatly different e values are actually prone to copolymerization, block copolymerization does not occur, but random copolymerization occurs more smoothly, and the composition of the actually obtained side chain can be improved. close to the added composition.

In addition, the unsaturated bond in the modified resin is derived from unsaturated dicarboxylic acids such as maleic acid and itaconic acid, or allyl compounds with hydroxyl or carboxyl groups such as glycerol monoallyl ether, and the e value, because maleic acid, itaconic acid, etc. have an electron-withdrawing carboxyl group as a substituent in the unsaturated bond, the e value is 1.0 to 3.0 (1.0 to 2.0 in the case of a diester), which is extremely high. A large positive value means that the charge in the unsaturated bond tends to be positive; in the case of an allyl compound, due to the resonance of the allyl group, it is a very large negative value of -1.0 to 2.0, and the unsaturated bond tends to be negative. When performing grafting, by using a radically polymerizable monomer with high copolymerizability (that is, the positive and negative values of e are opposite and the difference in e value is large) with respect to the unsaturated bond in the resin to be modified, it is possible to suppress complete grafting. Homopolymerization occurs without reacting with the resin to be modified. That is, the modified resin of maleic acid whose e value is very large and positive is easily combined with monomers with an e value of 0.9 or more and monomers below -0.6, which are necessary for the present invention. The negative value is very large The monomer is copolymerized, so that the grafting efficiency is improved, and the modified resin with an allyl group with a large negative e value is easy to copolymerize with a monomer with a large positive value, so the grafting efficiency is also improved at this time , In any case, the amount of the homopolymer of the radically polymerizable monomer that does not react with the resin to be modified can be reduced. In addition, the present invention is characterized in that gelation is suppressed by a combination ratio of a monomer having an e value of 0.9 or more and a monomer of -0.6 or less. In the past, in the modification of unsaturated bond-containing resins by radical polymerizable monomers, when the amount of unsaturated bonds in the modified resin was small, grafting could not be performed sufficiently, resulting in radical polymerizable resins. Homopolymers of monomers, in addition, when the amount of unsaturated bonds in the modified resin is large, gelation occurs due to the combination between the grafted side chains, which makes the actual unsaturated bonds in the modified resin The range of bonds is extremely narrow, but in the present invention, gelation can be suppressed even when the amount of unsaturated bonds is very large by the combination ratio of a monomer having an e value of 0.9 or more and a monomer of -0.6 or less. In the case of combining monomers having an e value not in the above-mentioned range, the above-mentioned effect is low.

In addition, the side chain used here is, as described above, the side chain component of which is a combination of a radical polymerizable monomer having an e value of 0.9 or more in the Q-e value in radical polymerization and a monomer having an e value of -0.6 or less. It is constituted as an essential mixture, and an aromatic radical polymerizable monomer is included in this component. The inventors of the present invention have repeatedly investigated the reasons for the reduction of various physical properties, especially mechanical properties, water resistance, etc., due to modification, and found that the modified resin is aromatic polyester and polyester polyurethane resin (hereinafter referred to as the basis) resin), the mechanical properties change according to the composition of the side chain, especially when an aromatic radically polymerizable monomer is used as a component of the side chain to improve the compatibility between the main chain and the side chain, a large Amplitude inhibits the decline of mechanical properties. When an aromatic radically polymerizable monomer is not used as a side chain at all, it is observed that the compatibility between the main chain and the side chain is low, and that among various physical properties, especially the elongation of the coating film is significantly reduced.

(polyester resin)

The polyester resin refers to the polyester whose aromatic dicarboxylic acid component accounts for more than 60 mol% of the total acid component, and its ideal composition is: dicarboxylic acid or/and ethylene glycol with polymerizable unsaturated double bonds, 0.5 to 20 mol% of polyester is copolymerized with respect to the total dicarboxylic acid component or the total ethylene glycol component. Aliphatic and/or alicyclic dicarboxylic acid is 0 to 40 mol%. The aromatic dicarboxylic acid may, for example, be terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid or bisphenyl dicarboxylic acid.

As the aliphatic dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, dimer acid, etc. can be exemplified; as the alicyclic dicarboxylic acid, 1, 4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid and its anhydride, etc.

Examples of dicarboxylic acids having polymerizable unsaturated double bonds include α, β-unsaturated dicarboxylic acids, fumaric acid, maleic acid, maleic anhydride, itaconic acid, and citraconic acid. Alicyclic dicarboxylic acids with saturated double bonds include 2,5-norbornane dicarboxylic anhydride and tetrahydrophthalic anhydride. The most desirable ones are fumaric acid, maleic acid, itaconic acid, and 2,5-norbornane dicarboxylic anhydride.

In addition, hydroxycarboxylic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, or hydroxytrimethylacetic acid, γ-butyrolactone, and ε-caprolactone can be used as needed.

In addition, the ethylene glycol component is composed of aliphatic ethylene glycol having 2 to 10 carbon atoms and/or alicyclic ethylene glycol having 6 to 12 carbon atoms and/or ethylene glycol containing an ether bond. Aliphatic ethylene glycol having 2 to 10 atoms, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, Diol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol, hydroxytrimethylacetic acid Pentaerythroxylate, dimethylol heptane, etc. Examples of the alicyclic ethylene glycol having 6 to 12 carbon atoms include 1,4-cyclohexanedimethanol and tricyclodecanetrimethylol.

Examples of ethylene glycol containing an ether bond include adding 1 to several moles of ethylene oxide or propylene oxide to each of the two phenolic hydroxyl groups of diethylene glycol, triethylene glycol, dipropylene glycol, and bisphenols. The obtained glycols are, for example, 2,2-bis(4-hydroxyethoxyphenyl)propane and the like. Polyethylene glycol, polypropylene glycol, and polytetramethylene glycol can also be used as needed.

In the polyester resin used in the present invention, when a dicarboxylic acid having a polymerizable unsaturated double bond is used as the dicarboxylic acid component in an amount of 0.5 to 20 mol % relative to the total acid component, the aromatic dicarboxylic acid is 60 to 99.5 mol%, preferably 70 to 99 mol%, and the aliphatic dicarboxylic acid and/or alicyclic dicarboxylic acid is 0 to 40 mol%, preferably 0 to 30 mol%. If the aromatic dicarboxylic acid is less than 60 mol%, the processability of the coating film and the expansion resistance and blister resistance of the coating film after retort treatment will decrease. In addition, if the aliphatic dicarboxylic acid and/or the alicyclic dicarboxylic acid exceeds 40 mol%, not only the hardness, stain resistance, and elbow resistance will decrease, but also because the aliphatic ester bond is more resistant to water than the aromatic ester bond. Therefore, problems such as a decrease in the degree of polymerization of polyester may occur during storage.

The dicarboxylic acid having a polymerizable unsaturated double bond is 0.5 to 20 mol%, preferably 1 to 12 mol%, more preferably 1 to 9 mol%. When the dicarboxylic acid having a polymerizable unsaturated double bond is less than 0.5% by mole, the effective grafting of the acrylic monomer composition to the polyester resin cannot be carried out, and the main product is composed only of the free radical polymerizable monomer composition. The homopolymer of the target modified resin cannot be obtained.

When the dicarboxylic acid having a polymerizable unsaturated double bond exceeds 20 mol %, various physical properties decrease greatly, and in the late stage of the grafting reaction, the viscosity rises excessively, entangles the mixer, and hinders the uniform progress of the reaction. , so it is not ideal.

Glycerin monoallyl ether, trimethylpropane monoallyl ether, pentaerythritol monoallyl ether, etc. are mentioned as ethylene glycol which has a polymerizable unsaturated double bond.

When ethylene glycol containing a polymerizable unsaturated double bond is used, the ratio may be 0.5 to 20 mol%, preferably 1 to 2 mol%, more preferably 1 to 9 mol%, based on the total ethylene glycol component . When the total amount of ethylene glycol and dicarboxylic acid having polymerizable unsaturated double bonds is less than 0.5 mol %, the effective grafting of the free radical polymerizable monomer composition of polyester resin cannot be carried out, and only free A homopolymer composed of a polymer-based monomer composition cannot obtain the target modified resin.

When introducing polymerizable unsaturated bonds into polyester, use dicarboxylic acid or/and ethylene glycol, but the total amount of ethylene glycol and dicarboxylic acid having polymerizable unsaturated double bonds can be up to 20 mol%, if more than 20 If the mole % is too low, various physical properties will drop greatly, and in the late stage of the grafting reaction, the viscosity will rise too much, and it will be entangled in the mixer to hinder the uniform progress of the reaction, so it is not preferable.

In the above-mentioned polyester resin, 0 to 5 mol% of polycarboxylic acid and/or polyhydric alcohol with more than three functions are copolymerized. As polycarboxylic acid with more than three functions, (anhydrous) trimellitic acid, (anhydrous ) pyromellitic acid, (anhydrous) benzophenone tetracarboxylic acid, trimellitic acid, ethylene glycol bis(trimellitate), glycerol tri(trimellitate), etc. On the other hand, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, etc. can be used as a trifunctional or more polyhydric alcohol. Polyacids and/or polyhydric alcohols with more than three functions are ideally 0 to 5 mol% relative to the total acid component or total glycerin component, and can be copolymerized in the range of 0.5 to 3 mol%, but if it exceeds 5 mol%, it cannot Provide sufficient workability.

The weight average molecular weight of the polyester resin is in the range of 5,000 to 100,000, preferably in the range of 7,000 to 70,000, more preferably in the range of 10,000 to 50,000. If the weight-average molecular weight is less than 5,000, various physical properties will decrease, and if the weight-average molecular weight is more than 100,000, the viscosity will increase during the progress of the grafting reaction, hindering the uniform progress of the reaction.

(Polyurethane resin)

The polyurethane resin of the present invention is composed of polyester polyol (a), organic diisocyanate compound (b) and chain extender (c) having an active hydrogen group if necessary, and has a weight average molecular weight of 5,000 to 100,000. Urethane The bond content is 500 to 4000 equivalents/10 ⁶ g, and the polymerizable double bond content per chain is 1.5 to 30 on average. The polyester polyol (a) used in the present invention is produced using the compounds already exemplified in the section of polyester as dicarboxylic acid components and ethylene glycol components, and it is desirable that both terminal groups are hydroxyl groups and the weight average molecular weight is 500-10000 polyester polyol. As in the case of polyester, the aromatic dicarboxylic acid component in the polyester polyol used in the present invention is at least 60 mol % or more, preferably 70 mol % or more.

Aliphatic polyester polyols widely used in polyurethane resins, such as polyurethane resins using adipate esters of ethylene glycol or pentaerythyl glycol, have extremely low water resistance. As an example, the reduced viscosity retention rate after soaking in warm water at 70°C for 20 days is low at 20 to 30%. Alcohol resins have a reduction viscosity retention rate of 80-90% under the same conditions, which is relatively high. Therefore, in order to achieve high water resistance of the coating film, it is necessary to use a polyester polyol mainly composed of an aromatic dicarboxylic acid. Moreover, polyester polyol, polycarbonate diol, polyolefin polyol, etc. can also be used together with these polyester polyols as needed.

As the organic isocyanate compound (b) used in the present invention, hexamethylene diisocyanate, tetramethylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, p- Xylylene diisocyanate, m-xylylene diisocyanate, 1,3-diisocyanate methylcyclohexane, 4,4'-diisocyanate dicyclohexane, 4,4'-diisocyanate cyclohexane, Isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, 2,4-naphthalene diisocyanate Isocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 4,4'-diisocyanate diphenyl ether, 1,5-naphthalene diisocyanate, etc.

The chain extender (c) having an active hydrogen group used as required, for example, ethylene glycol, propylene glycol, pentaerythiol, 2,2-dimethyl-1,3-propanediol, diethylene glycol, Glycols such as spiroethylene glycol and polyethylene glycol, and amines such as 1,6-hexanediamine, propylene diamine, and 1,6-hexanediamine.

Described polyurethane resin, needs it to be a kind of polyester polyol (a), organic diisocyanate (b), and will have the chain extender (c) of active hydrogen group as required, make (a)+(c) The mixing ratio of the active hydrogen group/isocyanate group is 0.4 to 1.3 (equivalent ratio), and the polyurethane resin obtained by the reaction is carried out.

When the active hydrogen group/isocyanate group ratio of (a)+(c) exceeds this range, the polyurethane resin cannot be sufficiently increased in molecular weight, and desired coating film physical properties cannot be obtained. The polyurethane resin used in the present invention is produced by a known method in a solvent at a reaction temperature of 20 to 150° C. in the presence or absence of a catalyst. Examples of the solvent used at this time include ketones such as butanone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; and esters such as ethyl acetate and butyl acetate. As a catalyst for promoting the reaction, amines, organotin compounds, and the like can be used.

The polyurethane resin used in the present invention contains an average of 1.5 to 30 polymerizable double bonds in each urethane chain in order to improve the grafting reaction efficiency of free radical polymerizable monomers, preferably 2 to 20, more preferably It is ideal to contain 3 to 15 pieces.

There are the following three methods for introducing the polymerizable double bond.

1) Polyester polyol contains unsaturated dicarboxylic acids such as maleic acid, itaconic acid, and norbornane dicarboxylic acid.

2) The polyester polyol contains ethylene glycol containing allyl ether.

3) As a chain extender, ethylene glycol containing allyl ether is used.

These can be used alone or in combination. The polymerizable double bond in the main chain introduced in 1) has a strong electron-accepting property with an e value of 0.9 or more, and the polymerizable double bond introduced in 2) and 3) has a strong electron-donating property with an e value of -0.6 or less .

In this way, the size and amount of the electron-accepting or electron-donating properties of the polymerizable double bond introduced into the base resin are considered, and in view of this, the electron-donating and electron-accepting monomers are also considered for the radically polymerizable monomers. Combination methods, quantitative ratios, and provision for grafting reactions are the key points of the present invention.

The conventional theory for the formation of graft or block polymers is that the number of polymerizable double bonds on each main chain is one in the main chain or at the end. In fact, in the previous several patent methods, the number of polymeric double bonds introduced into the main chain is actually in a statistical distribution, so the ratio of chain components with 0 on each main chain is increased, thus connecting Branch efficiency is reduced. However, if the amount of double bonds is increased, gelation occurs and the suitable range is extremely narrowed. On the other hand, the method of the present invention based on the principle of the alternation of reactions between radically polymerizable chemical species has the advantage of having a wide range of applications to meet the two requirements of grafting efficiency and avoidance of gelation.

(radical polymerizable monomer)

In general, in radical copolymerization, the e value of the Q-e value proposed by Alfrey-Price is a value that empirically represents the electronic state of the unsaturated bond part of the radical monomer. When the Q value does not have a large difference, it is beneficial to To explain the copolymerization reaction, these values are described in Polymer Handbook 3rd ed. John Wiley and Sons. et al.

As a radically polymerizable monomer having an e value of 0.9 or more in the Q-e value that must be used in the present invention, it is a monomer having an electron-withdrawing substituent in the unsaturated bond portion, and fumaric acid, fumaric acid, and fumaric acid can be used. Monoethyl fumarate, diethyl fumarate, dibutyl fumarate and other fumaric acid monoesters and fumaric acid diesters, maleic acid and its anhydride; monoethyl maleate, diethyl maleate Maleic acid monoester and maleic acid diester such as dibutyl maleate; itaconic acid, itaconic monoester and itaconic acid diester; A mixture of at least one selected from imine, acrylonitrile, etc., most preferably maleic anhydride and its esters, fumaric acid and its esters.

A radically polymerizable monomer having an e value of -0.6 or less as the Q-e value that must be used in the present invention is a monomer having an electron-donating substituent on an unsaturated bond, or a conjugated monomer , Vinyl radically polymerizable monomers such as styrene, α-methylstyrene, tert-butylstyrene, N-vinylpyrrolidone, etc.; vinyl esters such as vinyl acetate; vinyl butyl ether, vinyl isobutyl ether, etc. Vinyl ether; allylic radically polymerizable monomers such as allyl alcohol, glycerol monoallyl ether, pentaerythritol monoallyl ether, trimethylolpropane allyl ether; at least one or more selected from butadiene, etc. The most ideal is a vinyl radical polymerizable monomer such as styrene.

In the present invention, a combination of a radical polymerizable monomer having an e value of 0.9 or more and a radical polymerizable monomer having an e value of -0.6 or less is required, and the combination occupies at least 50% by weight or more, more preferably 60% by weight or more. In addition, regarding the unsaturated bond contained in the resin to be modified, among the above two radically polymerizable monomers, the radically polymerizable monomer with high copolymerizability (that is, the unsaturated bond in the resin to be modified) It is desirable that the content of the total radical polymerizable monomer is more than 20% by weight, while the content of the radically polymerizable monomer with low copolymerizability (with the monomer in the modified resin It is desirable that the content of the monomer having a small difference in the e value of the unsaturated bond) is 20% by weight or more in the total radical polymerizable monomers. When the former is less than 20 parts by weight, sufficient grafting efficiency to the main chain cannot be obtained, and the radical polymerizable monomer undergoes homopolymerization. If the latter is less than 20% by weight, gelation will occur during the grafting reaction and grafting will not proceed smoothly.

In addition, as other radically polymerizable monomers copolymerizable with the above-mentioned essential components as needed, radically polymerizable monomers having an e value of -0.6 to 0.9 can be used. For example, acrylic acid, methacrylic acid, and ethyl acrylate, ethyl methacrylate, etc. as their esters; as free radical polymerizable monomers containing nitrogen atoms, acrylamide, methacrylonitrile, etc. One or more monomers containing one radically polymerizable double bond per molecule are selected and used. Thereby, Tg of the side chain and compatibility with the main chain can be adjusted, and arbitrary functional groups can be introduced.

As the aromatic radically polymerizable monomer essential in the side chain component, a radically polymerizable monomer having an aromatic ring can be exemplified, and styrene, such as styrene, α-methylstyrene, and chloromethylstyrene, can be used. Derivatives; phenoxyethyl acrylate, phenoxyethyl methacrylate, benzyl acrylate, benzyl methacrylate, etc. -2-hydroxyethyl acrylate (HEA) and methacrylic acid-2- Hydroxyethyl ester (HEMA) and reactants of aromatic compounds; phthalic acid derivatives such as 2-acryloyl hydroxyethyl hydrogen phthalate and esters of HEA and HEMA; and acrylic acid, methacrylic acid and benzene Reactants such as glycidyl ether, that is, 2-hydroxy-3-phenoxypropane (meth)acrylate, etc., introduce an aromatic ring into the side chain. In the present invention, the proportion of the aromatic radically polymerizable monomer is at least 10% by weight relative to the total radically polymerizable monomer, preferably 20% by weight or more, and most preferably 30% by weight. % by weight or more.

(grafting reaction)

The graft polymer in the present invention is obtained by graft-copolymerizing a radically polymerizable monomer with a polymerizable unsaturated double bond in the above-mentioned base resin. In the present invention, the graft polymerization reaction is carried out by reacting a mixture of a radical initiator and a radical polymerizable monomer in a state where a base resin containing a polymerizable double bond is dissolved in an organic solvent. The reaction product after the grafting reaction is usually composed of a base resin not grafted and a monomer polymer not grafted to the base resin except for the graft polymer. Generally, when the ratio of grafted polymer in the reaction product is low, and the ratio of non-grafted base resin and non-grafted individual polymer is high, the effect of modification is low, and it is observed that the coating film due to non-grafted homopolymer Harmful effects such as bleaching. Therefore, it is important to select reaction conditions in which the ratio of graft copolymer formation is high.

When the base resin is subjected to the grafting reaction of the radical polymerizable monomer, the radical polymerizable monomer mixture and the radical initiator can be added at the same time to the base resin dissolved in the solvent under heating, or can be added dropwise After a certain period of time, stir for a certain period of time and continue to heat to carry out the reaction. In addition, one of the ideal embodiments of the present invention is to preliminarily add a radically polymerizable monomer having a small difference from the e value of the polymerizable double bond of the base resin, and then add the e value of the polymerizable double bond of the base resin over a certain period of time. The radically polymerizable monomers and initiators whose values differ greatly are reacted by heating under stirring for a certain period of time.

Before the reaction, add the base resin and solvent into the reactor, and dissolve the resin by raising the temperature while stirring. It is ideal that the weight ratio of the base resin and the solvent is in the range of 70/30 to 30/70. At this time, the reactivity of the base resin and the radically polymerizable monomer and the solubility of the solvent are considered, and the weight ratio is adjusted to a weight ratio that enables uniform reaction in the polymerization step. The temperature of the grafting reaction is ideal at 50-120°C. The weight ratio of the ideal base resin and radical polymerizable monomer adapted to the purpose of the present invention is based on the base resin/side chain part, and is in the range of 25/75 to 99/1, most preferably 50/50 to 95/1 5 range. If the weight ratio of the base resin is less than 25% by weight, the excellent properties of the base resin described above, namely, high processability, excellent water resistance, and adhesion to various substrates cannot be fully exhibited. When the weight ratio of the base resin is above 99% by weight, the proportion of the ungrafted base resin in the polyester or polyester polyurethane resin is almost the same, and the modification effect is low, which is not ideal.

The weight average molecular weight of the graft chain portion in the present invention is 1,000 to 100,000. When graft polymerization is carried out by graft reaction, it is generally difficult to control the weight average molecular weight of the grafted chain portion to 1000 or less, the grafting efficiency is lowered, and it is not possible to sufficiently impart functional groups to the base resin, which is not preferable. In addition, when the weight-average molecular weight of the graft chain portion is 100,000 or more, the viscosity of the polymerization reaction increases significantly, and the intended polymerization reaction in a homogeneous system cannot proceed. The control of the molecular weight described here can be performed by appropriately combining the amount of the initiator, the time of dropping the monomer, the time of polymerization, the reaction solvent, the composition of the monomer, or if necessary, a chain transfer agent or a polymerization inhibitor.

(free radical initiator)

As the radical polymerization initiator used in the present invention, well-known organic peroxides or organic azo compounds can be utilized. That is, examples of organic peroxides include benzoyl peroxide and tert-butylperoxytrimethylethyl ester, and examples of organic azo compounds include 2,2'-azobisisobutyronitrile, 2 , 2'-azo (2,4-dimethylvaleronitrile), etc.

When selecting a free radical initiator compound, it is necessary to consider the free radical generation rate of the compound at the reaction temperature, that is, the half-life (Half-Life). Usually, the free radical initiator is selected so that the half-life value at this temperature is in the range of 1 minute to 2 hours. The amount of the radical initiator used for the grafting reaction is at least 0.2% by weight or more, preferably 0.5% by weight or more, based on the radically polymerizable monomer.

To adjust the length of the grafted chains, chain transfer agents such as n-octyl mercaptan, dodecyl mercaptan, mercaptoethanol are used as required. In this case, it is desirable to be in the range of 0 to 20% by weight relative to the radical polymerizable monomer.

(reaction solvent)

As the reaction solvent, for example, ketones such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate, and other widely used solvents can be used. However, the selection of the reaction solvent used in the grafting reaction is extremely important. The conditions required for an ideal reaction solvent are 1) solubility, 2) suitability as a radical polymerization solvent, 3) boiling point of the solvent, and 4) solubility of the solvent in water. 1) It is important to dissolve or disperse the base resin while dissolving the branched portion of the graft copolymer composed of the unsaturated monomer mixture and the non-grafted homopolymer as well as possible. 2), it is important that the solvent itself decomposes the radical initiator (induced decomposition) or that the combination between the specific organic peroxide and the specific ketone solvent does not lead to explosive hazards as reported, and as free radicals The polymerization reaction solvent has a suitably small chain transfer constant. In 3), since the graft addition reaction of the radically polymerizable monomer is generally an exothermic reaction, in order to maintain a constant temperature, it is desirable to perform it under the condition of circulation of the solvent. 4) It cannot be said that it is an essential and necessary condition for the grafting reaction itself. When the modification introduces a hydrophilic functional group into the base resin and disperses the modified resin in water for the purpose, from the viewpoint of industrialization, the ideal is The solvent selected under the requirements of 1) to 3) is an organic solvent that can freely dissolve in water, or has a high mutual solubility between water and an organic solvent. When the above-mentioned fourth requirement is satisfied, the grafting reaction product containing the solvent is directly neutralized with a basic compound under heating, and then water is added to form an aqueous dispersion. More preferably, the boiling point of the freely soluble or highly mutually soluble organic solvent is lower than that of water. At this time, from the aqueous dispersion formed as described above, the organic solvent is discharged out of the system by simple distillation.

The solvent for the grafting reaction of the present invention may be a single solvent or a mixed solvent. Solvents with a boiling point higher than 250°C have too slow an evaporation rate and cannot be fully discharged even through high-temperature baking of the coating film. When a solvent having a boiling point of 50° C. or lower is used as a solvent for the grafting reaction, an initiator that cracks into radicals at a temperature of 50° C. or lower must be used, which increases the risk in handling and is not preferable.

When the resulting polyester or polyester polyurethane resin is dispersed in water, it can be used in the reaction solvent of the grafting reaction to dissolve or disperse the base resin and to mix the free radical polymerizable monomer mixture and its polymer. The ideal solvent for dissolving can be exemplified by ketones such as butanone, methyl isobutyl ketone, cyclohexanone; cyclic ethers such as tetrahydrofuran, dioxane; glycol ethers such as propylene glycol methyl ether, propylene glycol propyl ether, Ethylene glycol ether, ethylene glycol butyl ether; carbitols such as methyl carbitol, ethyl carbitol, butyl carbitol; glycols or lower esters of glycol ethers such as ethylene glycol Alcohol diacetate, ethylene glycol ether acetate; ketone alcohols such as diacetone alcohol; N-substituted amines such as N, N-dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. .

When carrying out the grafting reaction in a single solvent, one can be selected from organic solvents that dissolve the base resin well. In addition, when carrying out in a mixed solvent, or only select a variety of organic solvents from the above-mentioned organic solvents to react, or sometimes select at least one organic solvent that dissolves the above-mentioned base resin well, and then add a low-grade solvent that hardly dissolves the base resin. The reaction may be performed in at least one of organic solvents such as alcohols, lower carboxylic acids, and lower amines, and may be performed in any solvent.

(Preparation method of water-dispersed polyester or polyester polyurethane resin)

The grafting reaction product of the present invention can be water-dispersed by neutralizing the hydrophilic functional group introduced by grafting with a basic compound or the like. The ratio of the radical polymerizable monomer containing a hydrophilic functional group to the radical polymerizable monomer not containing a hydrophilic functional group in the radical polymerizable monomer mixture depends on the type of monomer selected, the supply connection The weight ratio of the base resin/side chain part of the branching reaction is related. The acid value of the graft body is ideally 200-4000 equivalents/10 ¹ g, more ideally 500-4000 equivalents/10 ⁴ g. The basic compound is preferably a compound that volatilizes when a coating film is formed or when a curing agent is mixed and baked for curing, preferably ammonia, organic amines, or the like. As an ideal compound, triethylamine, N,N-diethylethanolamine, N,N-dimethylethanolamine, aminoethanolamine, N-methyl-N,N-diethanolamine, isopropylamine, imino Dipropylamine, ethylamine, diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, tert-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminodipropylamine, 3-methoxy Propylamine, monoethanolamine, diethanolamine, triethanolamine, etc. The basic compound is used so that the pH of the aqueous dispersion is preferably in the range of 5.0 to 9.0 by at least partial neutralization or complete neutralization depending on the carboxyl group content contained in the grafting reaction product.

In the case of water dispersion, the grafting reaction product may be obtained by removing the solvent contained in the grafting reaction product in advance with an extruder under reduced pressure to obtain a molten or solid (granule, powder), Throw it into water containing basic compounds, stir under heating to make water dispersions, but it is best to add basic compounds and water immediately after the grafting reaction ends, and continue heating and stirring to obtain water dispersions (one pot). In the latter case, part or all of the solvent that is miscible with water used in the grafting reaction may be distilled off or co-distilled with water as needed.

The crosslinking agent may, for example, be a phenolic resin, an amine resin, a polyfunctional epoxy resin, a polyfunctional isocyanate compound, various blocked isocyanate compounds thereof, or a polyfunctional aziridine compound. Examples of the phenol resin include formaldehyde condensates of alkylated phenols and cresols. Specifically alkylated (methyl, ethyl, propyl, isopropyl, butyl) phenol, p-tert-amylphenol, 4,4'-secondary phenolic butane, p-tert-butylphenol, ortho, or p-cresol, p-cyclohexylphenol, 4,4'-isopropylidene phenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenol-o-cresol, p-phenylphenol , xylenol and other formaldehyde condensates.

Examples of the amine resin include formaldehyde condensates such as urea, melamine, and benzoguanamine, and alkyl ether compounds of these alcohols having 1 to 6 carbon atoms. Specifically, methoxylated methylol urea, methoxylated methylol N, N-ethylene urea, methoxylated methylol dicyanodiamide, methoxylated methylol melamine , Methoxylated hydroxymethyl benzoguanamine, butoxylated hydroxymethyl melamine and butoxylated hydroxymethyl benzoguanamine, etc. Preferably, methoxylated methylolmelamine, butoxylated methylolmelamine, and methylolated benzoguanamine can be used alone or in combination.

Examples of epoxy compounds include diglycidyl ether of bisphenol A and its oligomers, diglycidyl ether of hydrogenated bisphenol A and its oligomers, diglycidyl phthalate, m-phenyl Diglycidyl Diformate, Diglycidyl Terephthalate, Diglycidyl p-Hydroxybenzoate, Diglycidyl Tetrahydrophthalate, Diglycidyl Hexahydrophthalate, Disuccinate Glycidyl ether, adipate diglycidyl ether, sebacate diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6- Hexylene glycol diglycidyl ether and polyalkylene glycol diglycidyl ethers, triglycidyl trimellitate, triglycidyl isocyanate, 1,4-diglycidyloxybenzene, diglycidyl Propylene urea, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl ether, triglycidyl ether of glycerol alkenyl oxide adduct, and the like.

As the isocyanate compound, there are aromatic and aliphatic diisocyanates; trivalent or higher polyisocyanates; low-molecular-weight compounds and high-molecular-weight compounds may be used. For example, tetramethylene diisocyanate; hexamethylene diisocyanate; toluene diisocyanate; diphenylmethane diisocyanate; hydrogenated diphenylmethane diisocyanate; xylylene diisocyanate; Isocyanate or trimers of these isocyanate compounds; and excess of these isocyanate compounds and, for example, ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, di Low-molecular-weight active hydrogen compounds such as ethanolamine and triethanolamine, or high-molecular-weight active hydrogen compounds of various polyester polyols, polyether polyols, and polyamines, etc., are obtained by reacting compounds with isocyanate groups at their terminals.

As the isocyanate compound, blocked isocyanate may also be used. Examples of isocyanate blocking agents include phenols such as phenol, thiophenol, methylthiophenol, cresol, xylenol, resorcinol, nitrophenol, and chlorinated phenol; acetone oxime, methyl ethyl ketoxime , cyclohexanone oxime and other oximes; methanol, ethanol, propanol, butanol and other alcohols; chlorine-substituted alcohols such as chloroethanol and 1,3-dichloro-2-propanol; tert-butanol and tert-amyl alcohol ε-caprolactone, δ-valerolactam, γ-butyrolactone, β-propiolactone and other lactones; other aromatic amines, imides, acetylacetone, acetyl Active methylene compounds such as ethyl acetate and ethyl malonate; mercaptans, imines, ureas, diaryl compounds, sodium sulfite, etc. The blocked isocyanate is obtained by addition-reacting the above-mentioned isocyanate compound and an isocyanate blocking agent by a conventionally known method.

A curing agent or an accelerator may be used in combination with these crosslinking agents. As the compounding method of the crosslinking agent, the method of mixing in the base resin can be exemplified, and there is also a method of dissolving polyester and polyester polyurethane resin in an organic solvent solution in advance, and then dispersing the mixed solution in water. The type of agent can be selected arbitrarily. The curing reaction is usually 5-40 parts of curing resin (solid content) mixed with 100 parts (solid content) of polyester and polyester polyurethane resin of the present invention, depending on the type of curing agent, at a temperature of 60-250 ° C The range is performed by heating for about 1 to 60 minutes. A reaction catalyst or accelerator may be used in combination if necessary.

(micronization method)

Resin dispersions having the above-mentioned ionic groups, and aqueous dispersions of polyester or polyester polyurethane resins can be made into larger particle sizes by slowly coagulating. As a method for achieving slow aggregation, it is effective to add an ionic compound such as an electrolyte to the aqueous dispersion to increase the ionic strength in the system. In addition, methods such as (1) cutting off ionic groups by photolysis, thermal decomposition, or hydrolysis, etc. (2) controlling the degree of dissociation of ionic groups by scanning temperature, pH, etc. (3) capping ionic groups by counter ions, etc. .

In the present invention, as a method of slowly coagulating, an ester compound of amino alcohol and carboxylic acid is added to the system, and amino alcohol and carboxylic acid produced by hydrolysis of the ester compound are generated in the system to increase the ionic strength. According to this method, since the ionic strength is increased without causing local concentration unevenness in the system, good resin fine particles with uniform ionic diameters can be obtained.

(abrasive)

As the abrasive grains used in the present invention, abrasive abrasive grains can be used without particular limitation. Preferable examples are silicon oxide, cerium oxide, aluminum oxide, zirconium oxide, ferrous oxide, chromium oxide, diamond, and the like. These abrasive grains can be appropriately selected according to the grinding object. It is particularly desirable that silicon oxide, cerium oxide, aluminum oxide, and these abrasive grains have excellent abrasive properties on silicon wafers themselves, silicon oxide films deposited on silicon wafers, metal wiring materials such as aluminum and copper, and glass substrates. Suitable abrasive grains can be appropriately selected in its grinding. In addition, these abrasive grains are fine-particle abrasive grains with an average particle diameter of 5 to 1000 nm, as described above.

In the present invention, the content of the abrasive grains contained in the polishing layer is preferably 20 to 95% by weight, particularly preferably 60 to 85% by weight. If the content of the abrasive grains is less than 20 parts by weight, the volume content of the abrasive grains decreases, and when a polishing pad is produced, the polishing speed may decrease or there may be no polishing speed. When the abrasive grains exceed 90% by weight, the viscosity of the mixed solution becomes very high when the resin forming the abrasive layer and the abrasive grains are mixed and molded, and processing suitability is lost. In addition, the strength of the coating film obtained by coating is insufficient, and peeling of the coating film occurs during polishing, which causes scratches.

(Preparation of grinding layer forming material: compounding)

The abrasive layer is formed by abrasive layer forming resin (polyester resin) or polyester or polyester urethane resin having the above-mentioned ionic group and abrasive fine particles, and these abrasive layer forming materials are dissolved and dispersed in a solvent as a solution or as a A solution obtained by mixing the above resin aqueous dispersion and abrasive grains is used.

When preparing these abrasive layer forming materials, resin (polyester resin) particles having ionic groups and abrasive particles can be composited. As a compounding method, a so-called hetero-aggregation method can be used.

Hereinafter, the case where a sodium sulfonate group is introduced into a polyester resin will be described. The surface of polyester resin microparticles into which sodium sulfonate groups have been introduced is generally negatively charged. It is known that inorganic particles generally change their polarity with pH. Particles such as silicon dioxide are negatively charged in the neutral region but positively charged at lower pH. If the water dispersion of polyester resin particles adjusted to be around neutral and the water dispersion of silica particles also adjusted to be near the neutral region are mixed, because the surfaces of both are negatively charged, they will interact with each other. Repulsion, maintaining a stable dispersed state. If acid is dropped into the system to slowly lower the pH, the surface charge of the silica particles changes from a certain point, and composite particles in which the surfaces of polyester resin particles are fully coated with silica particles can be obtained.

(grinding layer)

The method of forming the abrasive layer is not particularly limited, and the abrasive layer forming resin and the abrasive layer forming material (solution) containing abrasive grains are coated, for example, and then dried. The coating method is not particularly limited, and tape coating, brush coating, roll coating, spraying, and other various printing methods can be applied.

The resulting abrasive layer contained air bubbles. The method is not particularly limited as long as bubbles are formed in the polishing layer. The size of the bubbles is preferably 10 to 100 μm. As a method containing air bubbles, there may be exemplified

1) A method of forming a polishing layer by mixing a mixture of hollow resin fine particles having an internal cell diameter of 10 to 100 μm with a polishing layer forming material (solution).

2) A polishing layer forming method in which a polishing layer forming material (solution) is mixed with a liquid insoluble in a resin having an ionic group, and dried after coating to partially form air bubbles.

3) A method in which a polishing layer is formed by mixing a material (solution) for forming the polishing layer with a mixture of a substance that generates gas by thermal or photodecomposition, such as an azide compound, and then irradiating light or heating to generate bubbles after coating.

4) A method in which a polishing layer forming material (solution) is sheared at high speed by a stirring blade, and air bubbles are mechanically mixed to form a polishing layer and introduce air bubbles.

(grinding pad)

The polishing pad of the present invention is a polishing base having a polishing layer in which abrasive grains are dispersed in the above-mentioned polishing layer forming resin. Abrasive layers are usually obtained as thin plates by coating on a substrate. The thickness of the polishing layer is usually about 10 to 500 μm. Ideally, it is 50 to 500 μm. When the thickness of the abrasive layer is less than 10 μm, the life as an abrasive layer becomes remarkably short. On the other hand, when the thickness exceeds 500 μm, after the polishing layer is formed, curling becomes very severe, which hinders good polishing.

In addition, in the polishing pad of the present invention, the resin in which the abrasive grains are dispersed may be in the shape of a boat or a thin plate, but a polishing pad having a structure in which a polymer substrate is coated is ideal.

The polymer substrate is not particularly limited, and examples thereof include polyester-based, polyamide-based, polyimide-based, polyamideimide-based, acrylic-based, cellulose-based, polyethylene-based, polypropylene-based, polyester-based Polymer substrates made of materials such as olefin-based, polyvinyl chloride-based, polycarbonate, phenol-based, and urethane-based resins, among which polyester resins or polycarbonate resins are particularly preferable from the viewpoint of adhesiveness, strength, and environmental load. Ester resin, acrylic resin, ABS resin. The thickness of the polymer substrate is usually about 50 to 250 μm.

In the present invention, the bonding strength between the polishing layer and the polymer substrate is preferably 90 or more, particularly preferably 100, using a cross-cut test. A film having a value of less than 90 has weak adhesive force, and peeling of the coating film occurs during polishing, causing scratches.

In the polishing pad of the present invention, a buffer layer made of a material softer than the polishing layer may be laminated between the polishing layer and the polymer substrate in order to improve the uniformity of the object to be polished, and other layers may be laminated as required. The material of the buffer layer may, for example, be a nonwoven fabric, a resin-impregnated nonwoven fabric, various foamed resins (foamed polyurethane, foamed polyethylene), or the like. In addition, grooves may be suitably formed on the surface of the abrasive layer.

Adhesives or double-sided tapes are ideal for laminating the polymer substrate and buffer layer. In this case, the adhesive or the double-sided tape is not particularly limited, but is preferably an acrylic resin type, a styrene butadiene rubber type, or the like. In addition, the adhesive strength of this layer is preferably 600 g/cm or more in a 180-degree peel test. When the adhesive strength is less than 600 g/cm, peeling may occur between the polymer substrate and the buffer layer during polishing.

When the buffer layer is provided, the thickness of the polishing layer is preferably 250 μm to 2 mm, particularly preferably 300 μm to 1 mm or less. If the thickness of the polishing layer is less than 250 μm, the polishing layer will be less worn off during actual polishing, and the life of the polishing pad will be shortened, so it is not practical. In addition, if the thickness of the abrasive layer exceeds 2 mm, large cracks will be formed on the surface during drying after coating, and a beautiful coating film cannot be obtained. In this case, the thickness of the polymer substrate is preferably 0.25 to 1 mm.

Example

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the following examples.

Manufacturing example 1

In an autoclave equipped with a thermometer and a stirrer, add

Dimethyl terephthalate 96 parts by weight

Dimethyl isophthalate 94 parts by weight

5-sodium sulfur dimethyl isophthalate 6 parts by weight

Dimethylol tricyclodecane 40 parts by weight

Ethylene glycol 60 parts by weight

Pentaerythritol 91 parts by weight

Tetrabutoxy titanate 0.1 parts by weight

Heating at 180-230° C. for 120 minutes for transesterification. Then, the temperature of the reaction system was raised to 250° C., the system pressure was 0.13 to 1.3 Pa, and the reaction was continued for 60 minutes to obtain a copolyester resin (A1). Table 5 shows the composition, the number average molecular weight, and the amount of ionic groups of the copolyester resin (A1) measured by NMR or the like. The amount of the sodium sulfonate ion group is a value obtained by calculating the amount of ionic elements by the fluorescent X-ray analysis method, and then converting it.

Production examples 2 to 6

In addition to changing the type and composition ratio of polycarboxylic acid and polyhydric alcohol in Production Example 1, so that the composition, number average molecular weight and ion group amount of the obtained polyester resin are the values shown in Table 5-1, the same as Production Example 1 was polymerized in the same manner to obtain polyester resins (A2) to (A6).

In addition, in Table 5-1

TPA: Terephthalic acid

IPA: Isophthalic acid

SA: sebacic acid

CHDA Cyclohexanedicarboxylic acid

SIP 5-sodium sulfur dimethylisophthalate

F Fumaric Acid

EG Ethylene glycol

NPG Pentaerythritol

TCD Tricyclodecanedimethanol

CHDM Cyclohexanedimethanol

PG Propylene Glycol

MPD 3-methyl-1,5-pentanediol

Example 5

(manufacture of aqueous dispersion)

Dissolve 100 parts by weight of the copolyester resin (A1) obtained above at 70°C, 66 parts by weight of methyl ethyl ketone, and 33 parts by weight of tetrahydrofuran, and then add 200 parts of water at 68°C to obtain a copolymer with a particle diameter of about 0.1 μm. Aqueous system microdispersion of polyester resin. The obtained water-based microdispersion was charged into a distillation flask, distilled until the fraction temperature reached 100° C., and water was added after cooling to obtain a solvent-free copolyester water-based dispersion with a solid content concentration of 30%. About copolyester resin (A2)-(A4), it carried out similarly to the above, and obtained the aqueous dispersion. The particle diameters of the respective aqueous dispersions are shown in Table 5-2.

Table 5-2

copolyester (A1) (A2) (A3) (A4) Average particle size (μm) 0.1 0.08 0.05 0.04

(Manufacture of resin particles)

Add 1000 parts by weight of copolyester aqueous dispersion (A1) and 8.0 parts by weight of dimethylaminoethyl methacrylate in 3 liters of separable flasks of four mouths that are provided with thermometer, capacitor, stirring paddle, while stirring from The room temperature was raised to 80° C. over 30 minutes and kept at 80° C. for 5 hours. During this period, the pH value in the system dropped from 10.5 to 6.2, and the conductivity increased from 1.8mS to 9.0mS. This would suggest that dimethylaminoethanol produced by hydrolysis of dimethylaminoethyl methacrylate and the carboxyl group of methacrylic acid in methacrylic acid neutralize the amine and form a salt to increase the ionic strength.

At this time, it was confirmed by an optical microscope that the fine particles of about 0.1 μm present in the copolyester aqueous dispersion grew into composite fine particles through slow aggregation.

The separable flask was cooled in ice water until room temperature, and the particle size distribution of the grown polyester resin particles was measured. As a result, when the average particle size was 3.5 μm and the diameter was D, the particle size of the particles in the range of 0.5D to 2D was Occupancy rate is 92wt%.

The obtained polyester resin fine particles were dehydrated and washed with filter paper, and then dispersed in water to obtain an aqueous dispersion (B1) of polyester resin fine particles having a solid content concentration of 20% by weight.

For copolyester resins (A2) to (A4), aqueous dispersions of polyester resin microparticles (B2) to (B4) were obtained in the same manner as above. The average particle diameters are shown in Table 5-3.

Table 5-3

copolyester microparticles (B1) (B2) (B3) (B4) copolyester (A1) (A2) (A3) (A4) Average particle size (μm) 3.5 8.5 2.9 5.1

(Preparation of abrasive composite coating film)

Add 750 parts by weight of the water dispersion of the obtained polyester resin (A1) to a three-necked separable flask with a stirring paddle, then slowly add colloidal silicon dioxide (snodeik ST- XL) 844 parts by weight. The obtained mixed solution was a uniform dispersion without coagulation. Then, the dispersion was coated on a polyester film (cosmosyaying A4100 manufactured by Toyobo Co., Ltd.) using an applicator with a gap of 100 μm, and dried at 120° C. for 30 minutes to obtain a polished film (F1). In the obtained film, a polyester resin layer containing 60 wt % of silica abrasive grains was formed in a thickness of about 30 μm. In addition, as a result of observing the cross-section of the obtained coating with a scanning electron microscope, abrasive grains were dispersed in the polyester resin very beautifully without agglomeration.

Similarly, polishing films (F2) to (F4) were produced using the resins (A2) to (A4). As a result, the abrasive grains can be well dispersed in all the thin films, and a beautiful coating film can be formed.

(Production of Abrasive Agglomerated Particles)

In a 3-liter separable flask with a thermometer, a capacitor, and a stirring paddle, add 1000 parts by weight of a 20 wt % aqueous dispersion of the polyester resin particles (B1) obtained, and stir gently after confirming that the pH is 6.8 , while slowly adding a colloidal silica aqueous dispersion (snodeik ST-XL manufactured by Nissan Chemical Industries, Ltd.), polyester/silica = 30/70 (weight ratio).

The pH immediately after the addition was 6.5. Next, with the temperature kept at room temperature, 0.1 regulated hydrochloric acid was added dropwise to lower the pH to 1.8. Thereafter, the temperature was raised to 80° C. over 30 minutes, kept at 80° C. for 15 minutes, and then cooled to room temperature in ice water.

The resulting dispersion was dehydrated and washed with filter paper, and this operation was repeated until the pH of the washing water became 6 or higher, thereby obtaining composite fine particles (C1) of polyester resin and silica. As a result of observing the obtained composite fine particles (C1) with a scanning electron microscope, it was confirmed that the silica fine particles were attached to the surface of the polyester resin fine particles.

Similarly, composite fine particles (C1) to (C4) were obtained using polyester fine particles (B2) to (B4). Then, the obtained composite particles (C1) to (C4) are tightly filled into containers coated with or coated with a release agent, heated to a temperature above the Tg of each resin for about 1 hour, and formed into a circle with a thickness of 10 mm and a diameter of 60 cm. Disc (P1) ~ (P4).

Embodiment 6-1

(Preparation of Abrasive Composite Mixture)

Add 750 parts by weight of the aqueous dispersion of polyester resin (A1) obtained in a three-necked 3-liter separable flask with a stirring paddle, and then slowly add colloidal silicon dioxide (manufactured by Nissan Chemical Industry Co., Ltd.) as abrasive grains while stirring. snodeikST-XL) 844 parts by weight. The obtained mixed liquid was a uniform dispersion liquid without coagulation. Then, 8 parts by weight of hollow fine particles (eikus panseru 551DE manufactured by Fueirayido, Japan) were added as bubbles to the dispersion liquid while stirring slowly, to prepare an abrasive grain composite mixed liquid.

(Making of polishing pad)

The abrasive composite mixture was coated with a polyester film (cosmosyaying A4100 manufactured by Toyobo Co., Ltd.) using a coater with a gap of 100 μm, and then dried at 120° C. for 30 minutes to obtain an abrasive layer: abrasive film (F1). The obtained film had a polyester resin coating (abrasive layer) having a thickness of about 30 μm, containing 60% by weight of silica abrasive grains, and bubbles (30% by volume) having a diameter of about 30 μm. In addition, when the cross-section of the obtained abrasive layer was observed with a scanning electron microscope, the abrasive grains were dispersed in the polyester resin very beautifully without agglomeration.

Embodiment 6-2～4

In Example 5, except that the aqueous dispersion of the copolyester resin (A1) was changed to an aqueous dispersion of the copolyester resins (A2) to (A4), the abrasive grain composite mixed liquid was prepared in the same manner as in Example 5, Next, polishing pads: polishing films (F2) to (F4) were produced. Abrasive grains were well dispersed in the obtained polishing films (F2) to (F4), and a beautiful polishing layer could be formed.

(Embodiment 6-5)

(Preparation of Abrasive Composite Mixture)

Add 750 parts by weight of the aqueous dispersion of polyester resin (A1) obtained in a three-necked 3-liter separable flask with a stirring paddle, and then slowly add colloidal silicon dioxide (manufactured by Nissan Chemical Industry Co., Ltd.) as abrasive grains while stirring. snodeikST-ZL) 844 parts by weight. The obtained mixed liquid was a uniform dispersion liquid without coagulation. Then, the dispersion liquid was sheared at a high speed by a stirring blade, and air bubbles were sufficiently mixed to prepare an abrasive grain composite liquid mixture.

(Making of polishing pad)

The abrasive composite mixture was coated on a polyester film (cosmosyaying A4100 manufactured by Toyobo Co., Ltd.) using a coater with a gap of 100 μm, and dried at 120° C. for 30 minutes to obtain a polishing layer: polishing film (F5). The obtained film had a polyester resin coating (abrasive layer) containing 60% by weight of silica abrasive grains and bubbles (30% by volume) with a diameter of about 10 to 30 μm in a thickness of about 40 μm. In addition, as a result of observing the cross-section of the obtained abrasive layer with a scanning electron microscope, the abrasive grains were dispersed in the polyester resin very beautifully without agglomeration.

Example 7

(manufacture of aqueous dispersion)

Dissolve 100 parts by weight of copolyester resin (A1), 66 parts by weight of butanone, and 33 parts by weight of tetrahydrofuran at 70° C., and then add 200 parts of water at 68° C. to obtain a water solution of copolyester resin with a particle diameter of about 0.1 μm. System microdispersion. The obtained water-based microdispersion was charged into a distillation flask, distilled until the fraction temperature reached 100° C., and water was added after cooling to obtain a solvent-free copolyester water-based dispersion with a solid content concentration of 30%.

For polyester resin (A5), (A6), add polyester resin (A5) 60 weight parts, methyl ethyl ketone 70 weight parts, Virahol 20 parts by weight, 6.4 parts by weight of maleic anhydride, and 5.6 parts by weight of diethyl fumarate were heated and stirred to dissolve the resin in a state of circulation. After the resin was completely dissolved, drop into the polyester solution a mixture of 8 parts by weight of styrene and 1 part by weight of n-octyl mercaptan and dissolve 1.2 parts by weight of azobisisobutyronitrile in 25 parts by weight of butanone, isopropyl ketone, and A solution in a mixed solution of 5 parts by weight of alcohol was reacted for 3 hours to obtain a graft (B2) solution. 20 parts of ethanol was added to the graft solution, and after reacting with the maleic anhydride in the side chain of the graft in the state of circulation for 30 minutes, it was cooled to room temperature. Next, 10 parts by weight of triethylamine was added for neutralization, and then 160 parts of ion-exchanged water was added, followed by stirring for 30 minutes. Then, the solvent remaining in the medium is removed by heating to obtain the final aqueous dispersion (C2). The resulting aqueous dispersion was milky white, with an average particle size of 80 nm and a Type B viscosity of 50 cps at 25°C. The grafting efficiency of the graft body was 60%. The molecular weight of the side chain of the obtained graft was 8000.

Similarly, resin (A6) was grafted with the composition shown in Table 5-4 and Table 5-5, and various aqueous dispersions (C2) (C3) were produced. The results of composition analysis measured by NMR and the like are shown in the table. Each component in the table is represented by mol%. The average particle diameters of the aqueous dispersions are shown in Tables 5-6.

Table 5-4

In Table 5-4, St Styrene

                                                              

                                          

        Manh  Maleic Anhydride

      AIBN   Azobisisobutyronitrile

Table 5-5

water dispersion C2 C3 Graft B2 100 0 Graft B3 0 100 TEA 5 5 ion exchange water 80 80

TEA in Table 5-5 means triethylamine.

Table 5-6

water dispersion (C1) (C2) (C3) Basic polyepoxy resin (A1) (B2) (B3) Average particle size (μm) 0.1 0.08 0.05

Example 7-1

Add 350 parts by weight of the water dispersion of the obtained polyester resin (A1) and 350 parts by weight of the water dispersion (C3) in a three-necked separable flask with a stirring paddle, then slowly add colloidal silicon dioxide as abrasive grains while stirring (Snodeik ST-ZL manufactured by Nissan Chemical Industry Co., Ltd.) 844 parts by weight. The obtained mixed liquid was a uniform dispersion liquid without coagulation. Then, the dispersion was coated on a polyester film (cosmosyaying A4100 manufactured by Toyobo Co., Ltd.) using an applicator with a gap of 100 μm, and dried at 120° C. for 30 minutes to obtain a polished film (F1). The resulting film was formed with a polyester resin layer containing 60% by weight of silica abrasive grains to a thickness of about 30 µm. In addition, as a result of observing the cross-section of the obtained coating with a scanning electron microscope, the abrasive grains were not aggregated, but were very beautifully dispersed in the polyester resin.

Embodiment 7-2

Aqueous dispersions (C2) and (C3) were mixed in the same manner as in Example 7-1 to prepare a polished film (F2). This coating film can also disperse abrasive grains well, and can form a beautiful coating film.

Example 8

(Production example of polyester resin)

Add 466 parts of dimethyl terephthalate, 466 parts of dimethyl isophthalate, and 401 parts of pentaerythyl glycol into a stainless steel autoclave equipped with a stirrer, a thermometer and a partial circulation cooler , 443 parts of ethylene glycol, and 0.52 parts of tetra-n-butyl titanate were subjected to a transesterification reaction at 160° C. to 220° C. for 4 hours. Next, 23 parts of fumaric acid were added, and the temperature was raised from 200° C. to 220° C. over 1 hour to conduct an esterification reaction. Then, the temperature was raised to 255° C., and the reaction system was slowly decompressed, and then reacted for 1 hour and 30 minutes under a reduced pressure condition of 0.26 Pa to obtain a copolyester resin (A1). The obtained polyester (A1) was transparent light yellow. The composition measured by NMR etc. is as follows.

Dicarboxylic acid component: 47 mol% of terephthalate, 48 mol% of isophthalate, 5 mol% of fumaric acid

Glycol component: 50 mol% of pentaerythiol, 50 mol% of ethylene glycol

Polyesters (A2, A5, A6) shown in Tables 5-7 were produced in the same manner. The molecular weights of the respective polyesters and the results of composition analysis measured by NMR are shown in Tables 5-7. Each component in the table shows mol%.

Table 5-7

In Table 5-7,

TPA: Terephthalic acid

IPA: Isophthalic acid

SA: sebacic acid

F: fumaric acid

EG: Ethylene glycol

NPG: pentaerythiol

MPD: 3-methyl-1,5-pentanediol

(Manufacturing example of polyester polyurethane resin)

Add 466 parts of dimethyl terephthalate, 466 parts of dimethyl isophthalate, and 401 parts of pentaerythyl glycol into a stainless steel autoclave equipped with a stirrer, a thermometer and a partial circulation cooler , 443 parts of ethylene glycol, and 0.52 parts of tetra-n-butyl titanate were subjected to a transesterification reaction at 160° C. to 220° C. for 4 hours. Next, 23 parts of fumaric acid were added, and the temperature was raised from 200° C. to 220° C. over 1 hour to conduct an esterification reaction. Then, the temperature was raised to 255° C., and the reaction system was slowly decompressed, and then reacted for 1 hour under a reduced pressure condition of 0.39 Pa to obtain a polyester resin (A5). The obtained polyester (A5) was transparent light yellow. The composition measured by NMR etc. is as follows.

Dicarboxylic acid component: 47 mol% of terephthalate, 48 mol% of isophthalate, 5 mol% of fumaric acid

Glycol component: 50 mol% of pentaerythiol, 50 mol% of ethylene glycol

Add 100 parts of the polyester polyol, 100 parts of methyl ethyl ketone in a reactor equipped with a stirrer, a thermometer and a partial circulation cooler, and then add 3 parts of pentaerythiol, 15 parts of diphenylmethane diisocyanate, and two 0.02 part of butyltin lauric acid ester was reacted at 60°C to 70°C for 6 hours. Next, 1 part of dibutylamine was added, and the reaction system was cooled to room temperature to complete the reaction. The reduced viscosity of the obtained polyurethane resin (A3) was 0.52.

Polyester polyurethane (A4) was produced in the same manner. Table 5-7 shows the molecular weight of each polyester and the result of composition analysis measured by NMR, etc.; Table 5-8 shows the molecular weight of each polyester polyurethane and the result of composition analysis measured by NMR or the like.

Table 5-8

polyester polyurethane A3 A4 Polyester polyol (A5) 100 0 Polyester polyol (A6) 0 100 GMAE 0 3 NPG 3 0 MDI 20 0 IPDI 0 20 reduced viscosity 0.52 0.55

Table 5-8

GMAE Glycerin Monoallyl Ether

NPG pentaerythroxylate

MDI: Dimethylmethane diisocyanate

IPDI: Isophorone Diisocyanate

(manufacture of aqueous dispersion)

Add 60 parts of polyester resin (A1), 70 parts of butanone, 20 parts of isopropanol, 6.4 parts of maleic anhydride, fumaric acid di 5.6 parts of ethyl ester, heat and stir, and dissolve the resin under the state of circulation. After the resin is completely dissolved, drop a mixture of 8 parts of styrene and 1 part by weight of n-octyl mercaptan into the polyester solution and dissolve 1.2 parts of azobisisobutyronitrile in 25 parts of methyl ethyl ketone, 5 parts of isopropanol, etc. Parts of the solution in the mixed solution, and then reacted for 3 hours to obtain a graft (B1) solution. 20 parts of ethanol was added to the graft solution, and after reacting with the maleic anhydride in the side chain of the graft in the state of circulation for 30 minutes, it was cooled to room temperature. Next, 10 parts of triethylamine was added for neutralization, and then 160 parts of ion-exchanged water was added, followed by stirring for 30 minutes. Then, the solvent remaining in the solvent is removed by heating to obtain the final aqueous dispersion (C1). The resulting aqueous dispersion was milky white, with an average particle size of 80 nm and a Type B viscosity of 50 cps at 25°C. The grafting efficiency of the graft body was 60%. The molecular weight of the side chain of the obtained graft was 8000.

Similarly, resins (A2 to A4) were grafted at the compositions shown in Table 5-9 to produce various aqueous dispersions (C2 to C4) (Table 5-10). Compositional analysis results measured by NMR or the like. Each component in the table is represented by mol%.

Table 5-9

In Table 5-9,

St Styrene

EA Acrylic

MMA Methacrylic acid

BZA benzyl acrylate

DEF diethyl fumarate

Manh maleic anhydride

AIBN Azoisobutyronitrile

Table 5-10

water dispersion C1 C2 C3 C4 Graft B1 100 0 0 0 Graft B2 0 100 0 0 Graft B3 0 0 100 0 Graft B4 0 0 0 100 TEA 5 5 5 5 ion exchange water 80 80 80 80

In Table 5-10, TEA means triethylamine.

(Preparation of abrasive composite coating film)

The solid content of the water dispersion (C1) that adds the obtained water dispersion (C1) in 3 liters of separable flasks with stirring paddles is 23 parts by weight of 30 weight percent, then add 8.5 parts by weight of pure water and melamine crosslinking agent (mesh 325) 1.2 parts by weight for stirring. Then, 67 parts by weight of cerium oxide (sibelheiguna nano-order ceria) having an average particle diameter of 0.3 μm was slowly added as abrasive grains while stirring. The obtained mixed liquid was a uniform dispersion liquid without coagulation. Then, the dispersion liquid was coated on a polyester film (cosmosyaying A4100 manufactured by Toyobo Co., Ltd.) using an applicator with a gap of 100 μm, and dried at 120° C. for 30 minutes to obtain a polished film (F1). The obtained film was formed with a polyester layer containing 89% by weight of cerium oxide abrasive grains to a thickness of about 75 µm. In addition, as a result of observing the cross section of the obtained coating with a scanning electron microscope, the abrasive grains were dispersed in the polyester resin very beautifully without agglomeration.

Similarly, polishing films (F2) to (F4) were produced using aqueous dispersions (C2) to (C4). As a result, the abrasive grains were well dispersed and a beautiful coating film could be formed.

Comparative example 5-1

Attempt to mix 600 parts by weight of thermoplastic polyester resin (bayilon RV200 manufactured by Toyobo Co., Ltd., 0 eq/ton of ionic basis) and 400 parts by weight of silica powder with a diameter of 0.5 μm at a temperature above the Tg (68° C.) of the resin Melt mixed but could not be mixed due to very high viscosity.

Comparative example 5-2

Melt 800 parts by weight of thermoplastic polyester resin (bayilon RV200 manufactured by Toyobo Co., Ltd., 0 eq/ton of ionic groups) and 200 parts by weight of silica powder with a diameter of 0.5 μm at a temperature higher than Tg (68° C.) of the resin mix. The mixed solution was poured into a container for coating or coating with a release agent to obtain a disc-shaped polishing layer (polishing pad) with a thickness of 10 mm and a diameter of 60 cm. As a result of observing the cross-section of the obtained polishing pad with a scanning electron microscope, silica ions aggregated to form lumps of several micrometers.

Comparative example 5-3

3000 parts by weight of a polyether-based urethane prepolymer (adiplan L-325 manufactured by uniroyaru, 0 eq/ton of ion groups), a surfactant (dimethyl polysiloxane polyoxane polymer, Dong reidawokoning silicon company SH192) 19 parts by weight and cerium oxide (sibelheiguna nanoscale ceria) 5000 parts by weight, then exchange the stirrer, add curing agent (4,4'-methylene-bis(2- Chloroaniline)) 770 parts by weight, tried to stir at 400rpm, but the viscosity increased sharply, making it impossible to stir.

Comparative example 5-4

3000 parts by weight of a polyether-based urethane prepolymer (adiplan L-325 manufactured by uniroyaru, 0 eq/ton of ion groups), a surfactant (dimethyl polysiloxane polyoxane polymer, Dong Reidawokoning silicon company SH192) 19 parts by weight and 600 parts by weight of cerium oxide (sibelheiguna nano-scale ceria), stirred with a stirrer at 400 rpm to make a mixed solution, then exchanged the stirrer, and added the curing agent (4, 4'-methylene-bis(2-chloroaniline)) 770 parts by weight. After stirring for about 1 minute, the mixed solution was added to the disc-shaped open mold, and secondary hardening was carried out in an oven at 110° C. to obtain a foamed polyurethane block. The obtained foamed polyurethane had a Shore D hardness of 65, a compressibility of 0.5%, a specific gravity of 0.95, and an average cell diameter of 35 μm. As a result of observing the cross-section of the obtained polishing pad with a scanning electron microscope, silica ions aggregated to form lumps of several micrometers.

Tables 5-11 show the results of the following evaluations of the polishing pads and polishing films obtained in the above Examples and Comparative Examples.

(Evaluation of grinding properties)

As a polishing device, SPP600S manufactured by Okamoto Industrial Machinery Co., Ltd. was used, and the polishing characteristics were evaluated. The polishing rate was calculated from the time required to polish a 6-inch silicon wafer having a thermally oxidized film of 1 μm to about 0.5 μm. An interferometric film thickness measuring device manufactured by Taitaku Electronics Co., Ltd. was used for the measurement of the oxide film thickness. Regarding the grinding conditions, as the chemical solution, a solution that was added to ultrapure water at a flow rate of 150 ml/min to make pH 11 by adding KOH during the grinding process was used. The polishing load was 350 g/cm ² , the polishing fixed plate rotation speed was 35 rpm, and the wafer rotation speed was 30 rpm. Table 5-11 shows the polishing rate of the thermally oxidized silica film when polishing is performed under such conditions. The polishing films and polishing pads of the examples shown in Tables 5-11 all obtained a polishing speed of 1000 angstroms/minute. The grinding speed of 1200 Angstrom/minute or more is the most ideal.

(planarization characteristics)

A thermal oxide film of 0.5 μm was deposited on a 6-inch silicon dioxide wafer, and after predetermined patterning was performed, an oxide film of 1 μm was deposited with p-TEOS to obtain a patterned wafer with an initial step difference of 0.5 μm. The wafer was polished under the above-mentioned conditions, and after polishing, each level difference was measured to evaluate planarization characteristics. As planarization characteristics, two steps were evaluated. One is the local level difference, which is the level difference in a pattern in which lines with a width of 500 μm are arranged at a distance of 50 μm, and the other is the cutting amount of the recessed part of the investigation distance among lines and distances at equal intervals of 100 μm. The results are shown in Tables 5-11.

(scratch evaluation)

Using a wafer surface inspection device WM2500 manufactured by Topcon Corporation, the number of scratches of 0.2 μm or more on the oxide film surface of the polished 6-inch silicon wafer was evaluated. The results are shown in Tables 5-11.

Table 5-11

The polishing layer (polishing film) of the present invention has a high polishing rate, excellent flatness and uniformity, and less scratches.

Example 9-1

In a flask with a stirring paddle, 30 parts by weight of water dispersion polyester resin TAD1000 (manufactured by Toyobo Co., Ltd. with a glass transition temperature of 65° C., an ion base content of 816 eq/ton, and a solid content concentration of 30% by weight), and water Polyester resin TAD3000 (manufactured by Toyobo Co., Ltd. with a glass transition temperature of 30° C., an ion group content of 815 eq/ton, and a solid content concentration of 30% by weight) 40 parts by weight of the dispersion, and a crosslinking agent mesh of 325 (manufactured by Mitsui Sayiteik Co., Ltd.) After stirring and mixing 3 parts by weight and 0.7 parts by weight of antifoaming agent safuyinol DF75 (manufactured by Nissin Chemical Industry Co., Ltd.), 100 parts by weight of cerium oxide powder (manufactured by Bayikowuski Co., Ltd., with an average particle diameter of 0.2 μm) was sequentially added and stirred uniformly. The obtained coating solution was in the form of a paste, and was coated on a polycarbonate plate (manufactured by Mitsubishi Engineering Plastics) having a thickness of 0.4 mm using a plate-shaped diecoater to a thickness of about 400 μm. The obtained resin plate was dried in a hot air drying oven at 110° C. for about 20 minutes, cooled slowly, and then taken out. The obtained coating film had a thickness of about 350 μm on the polycarbonate substrate, and it was confirmed that cerium oxide fine particles were uniformly dispersed without agglomeration as a result of observing its cross section with a scanning electron microscope. In addition, as a result of peeling off the cross-cut tape of the obtained coating film, the number of remaining was 100, and no peeling was observed.

Next, the coated substrate was applied with a surface load of 1 kg/cm using polyethylene foam (Ascar C hardness 52 manufactured by Toray Co., Ltd.) and double-sided tape #5782 (manufactured by Sekisui Chemical Industry Co., Ltd.) with a thickness of 1 mm. ^2. The edge fits together to form a grinding pad. As a result of a 180-degree peel test on the adhesive strength between the coated film substrate and the polyethylene foam using a tensile tester, the adhesive strength was 1000 g/cm or more.

The polishing properties of the obtained polishing pads are shown in Tables 5-12. It was confirmed that the obtained polishing pad had a high polishing rate, extremely excellent planarization properties, and good uniformity.

Embodiment 9-2

In the same manner as in Example 9-1, except that instead of the water-dispersible polyester resin TAD3000, TAD2000 (manufactured by Toyobo Co., Ltd. with a glass transition temperature of 20° C., an ion base content of 1020 eq/ton, and a solid content concentration of 30% by weight) was used, and the A polishing pad was produced in the same manner as in Example 9-1 except that the coating material was changed from polycarbonate to ABS resin. The results are also shown together in Tables 5-12, and it was confirmed that the polishing rate was high, the planarization characteristics were extremely excellent, and the uniformity was also good.

Embodiment 9-3

In the same manner as in Example 9-1, except that instead of the water-dispersible polyester resin TAD1000, TAD2000 (manufactured by Toyobo Co., Ltd. with a glass transition temperature of 67° C., an ion base content of 300 eq/ton, and a solid content concentration of 34% by weight) was used, and the A polishing pad was produced in the same manner as in Example 9-1, except that the coating material was changed from polycarbonate to acrylic resin, and the drying temperature was changed to 80° C. and the drying time was changed to 40 minutes. The results are also shown together in Tables 5-12, and it was confirmed that the polishing rate was high, the planarization characteristics were extremely excellent, and the uniformity was also good.

Embodiment 9-4

In the same manner as in Example 9-1, production was carried out in the same manner as in Example 9-1, except that the coated surface was coated with a thickness of about 400 μm after coating the carbonate substrate. The thickness of the obtained coating film was about 700 μm, and after the cross-cut tape peeling test, the number of remaining pieces was 100, and the coating film did not change. As a result of polishing using this polishing pad, it was confirmed that the polishing speed was high, the planarization characteristics were extremely excellent, and the uniformity was also good.

Embodiment 9-5

In Example 9-1, except that the resin substrate and buffer layer bonded together are changed from polyethylene foam to polyester foam (Ascar C hardness 55), the same as Example 9-1 Produce in the same way. As a result of polishing using this polishing pad, it was confirmed that the polishing rate was high, the planarization characteristics were extremely excellent, and the uniformity was also good.

Reference example 1-1

Example 9-1 was produced in the same manner as in Example 9-1 except that the water-dispersed polyester resin TAD3000 was not mixed. As a result, the surface of the polished layer after drying had large cracks. As a result of polishing with such a polishing pad, a part of the coating film peeled off, and many scratches were observed on the polished wafer.

Reference example 1-2

In Example 9-1, except that the water-dispersible polyester resin TAD1000 was not mixed, a polishing pad was produced in the same manner as in Example 9-1. As a result, a good coating film was obtained, but the surface was slightly sticky. As a result of polishing with such a polishing pad, the wafer sticks to the surface of the polishing pad and vibrates strongly, and eventually the wafer is detached from the wafer holder.

Reference example 1-3

In Example 9-1, a resin substrate and a polyethylene foam were laminated together with almost no surface load applied to produce a polishing pad. As a result of measuring the adhesive force between the resin substrate of the polishing pad and the polyethylene foam by a 180-degree peel test, the adhesive force was only 400 g/cm. As a result of polishing with such a polishing pad, peeling occurs between the resin substrate coated with abrasive particles and the polyethylene foam layer during the polishing process, and polishing cannot be performed.

Reference example 1-4

In Example 9-1, a polishing pad was produced in the same manner as in Example 9-1 except that the cerium oxide powder (average particle diameter of 1.5 μm manufactured by Bayikowski Co., Ltd.) was changed to 500 parts by weight. The adhesion and film strength of the obtained polishing layer were extremely weak, and the coating film would be peeled off if the substrate material or the like was bent, and the polyethylene foam layer could not be laminated.

Example 10-1

In a flask with a stirring blade, 35 parts by weight of water dispersion polyester resin TAD1000 (manufactured by Toyobo Co., Ltd. with a glass transition temperature of 65° C., an ion base content of 816 eq/ton, and a solid content concentration of 30% by weight), and water Polyester resin TAD300 (manufactured by Toyobo Co., Ltd. with a glass transition temperature of 30° C., an ion group content of 815 eq/ton, and a solid content concentration of 30% by weight) 45 parts by weight of the dispersion, and a crosslinking agent mesh of 325 (manufactured by Mitsui Sayiteik Co., Ltd.) After stirring and mixing 3.5 parts by weight and 0.7 parts by weight of antifoaming agent safuyinol DF75 (manufactured by Nissin Chemical Industry Co., Ltd.), 95 parts by weight of cerium oxide powder (average particle diameter: 0.2 μm, manufactured by Bayikowski Co., Ltd.) were sequentially added and uniformly stirred. The obtained coating solution was in the form of a paste, and was coated on a polycarbonate plate (manufactured by Mitsubishi Engineering Plastics) having a thickness of 0.4 mm using a plate-shaped die coater to a thickness of about 400 μm. The obtained resin plate was dried in a hot air drying oven at 110° C. for about 20 minutes, cooled slowly, and then taken out. The obtained coating film had a thickness of about 350 μm on the polycarbonate substrate, and it was confirmed that cerium oxide fine particles were uniformly dispersed without agglomeration as a result of observing its cross section with a scanning electron microscope. In addition, when the obtained coating film was peeled across the tape, the remaining number was 100, and no peeling was observed.

Next, a polyethylene foam (Ascar C hardness 52 manufactured by Toray Co., Ltd.) and double-sided tape #5782 (manufactured by Sekisui Chemical Co., Ltd.) with a thickness of 1 mm was used to apply a surface load of 1 kg/cm ² to the coated substrate. While laminating, a surface load of 1 kg/cm ² was applied to the opposite side of the polyethylene foam to form a polishing pad while laminating. As a result of a 180-degree peel test on the adhesive strength between the coated film substrate and the polyethylene foam using a tensile tester, the adhesive strength was 1000 g/cm or more. The surface of the polishing pad was ground with a rotary grindstone to form grid-like grooves with a groove width of 1 mm, a groove pitch of 6.2 mm, and a depth of 400 μm.

The polishing properties of the obtained polishing pads are shown in Tables 5-12. It was confirmed that the obtained polishing pad had a high polishing rate, extremely excellent planarization properties, and good uniformity.

Example 10-2

In the same manner as in Example 10-1, except that instead of the water-dispersed polyester resin TAD3000, TAD2000 (manufactured by Toyobo Co., Ltd. with a glass transition temperature of 20° C., an ion base content of 1020 eq/ton, and a solid content concentration of 30% by weight) was used, and the coated The material of the layer was changed from polycarbonate to ABS resin, and a polishing pad was produced in the same manner as in Example 10-1. The obtained polishing pad was ground with a super high cutter to form grid-shaped grooves with a groove width of 2 mm, a groove pitch of 10 mm, and a depth of 0.5 mm. The results are also shown in Table 5-12, and it was confirmed that the obtained polishing pad had a high polishing rate, was extremely excellent in planarization characteristics, and had good uniformity.

Example 10-3

In the same manner as in Example 10-1, except that instead of the water-dispersible polyester resin TAD1000, TAD1200 (manufactured by Toyobo Co., Ltd. with a glass transition temperature of 67° C., an ion base content of 300 eq/ton, and a solid content concentration of 34% by weight) was used, and the The material of the coating is changed from polycarbonate to acrylic resin, so that the drying temperature is 80 ° C and the drying time is 5 minutes. A mold with a groove width of 1.5 mm, a groove spacing of 8 mm, and a depth of 300 μm is made with polytetrafluoroethylene resin. The pressure of 5 kg/cm ² was pressed against the sample, and after the groove was made, it was dried at a drying temperature of 80°C for 5 minutes, and a polishing pad was produced in the same manner as in Example 10-1. The results are also shown in Table 1, and it was confirmed that the obtained polishing pad had a high polishing rate, extremely excellent planarization characteristics, and good uniformity.

Example 10-4

In the same manner as in Example 10-1, the same operation was performed except that the polycarbonate substrate was coated with a thickness of about 400 μm on the coated surface. The thickness of the obtained coating film was about 700 μm, and the surface of the polishing pad was ground with a rotary grindstone to form grid-shaped grooves with a groove width of 1 mm, a groove pitch of 6.2 mm, and a depth of 700 μm. As a result of the cross-cut strip test of the obtained coating film, the number of remaining was 100, and the coating film did not change. As a result of polishing using this polishing pad, it was confirmed that the obtained polishing pad had a high polishing rate, extremely excellent planarization properties, and good uniformity.

Example 10-5

In Example 10-1, except that the buffer layer bonded to the resin substrate was changed from a polyethylene foam to a polyurethane foam (Ascar C hardness 55), it was the same as in Example 10-1. make. Concentric grooves with a width of 0.3mm, a depth of 0.3mm, and a pitch of 3mm were formed on the polished surface with a carbon dioxide gas laser. As a result of polishing using this polishing pad, it was confirmed that the polishing speed of the obtained polishing pad was high and flattened. The characteristics are extremely excellent, and the uniformity is also good.

Reference example 2-1

A polishing pad was produced in exactly the same manner as in Example 10-1 except that the groove forming operation was omitted. As a result of polishing the polishing pad obtained in this way, it was confirmed that the polishing was good in the first few minutes, but the vibration of the wafer gradually became severe, and eventually the wafer did not keep coming off.

Reference example 2-2

In Example 10-1, a polishing pad was produced in the same manner as in Example 10-1 except that the water-dispersed polyester resin TAD3000 was not mixed and grooves were not formed at the end. As a result, large cracks appeared on the surface of the polishing layer after drying. As a result of polishing the polishing pad thus obtained, a part of the coating film was peeled off, and many scratches were observed on the wafer.

Reference example 2-3

In Example 10-1, a polishing pad was produced in the same manner as in Example 10-1 except that the water-dispersed polyester resin TAD1000 was not mixed and grooves were not formed at the end. As a result, a good coating film was obtained, but the surface was slightly sticky. As a result of polishing with such a polishing pad, the wafer sticks to the surface of the polishing pad and vibrates strongly, and eventually the wafer is detached from the wafer holder.

Reference example 2-4

In Example 10-1, a resin substrate and a polyethylene foam were bonded together with almost no surface load to produce a polishing pad, and a polishing pad was produced in the same manner as in Example 10-1, except that grooves were not formed at the end. . As a result of measuring the adhesive force between the resin substrate of the produced polishing pad and the polyethylene foam by a 180-degree peel test, the adhesive force was only 400 g/cm. As a result of polishing with such a polishing pad, peeling occurred between the resin substrate coated with abrasive particles and the polyethylene foam layer during the polishing process when several wafers were processed, and polishing could not be performed.

Reference example 2-5

In Example 10-1, a polishing pad was produced in the same manner as in Example 10-1, except that 500 parts by weight of cerium oxide powder (average particle diameter 1.5 μm manufactured by Bayikowski Co., Ltd.) was used and grooves were not formed at the end. The adhesive force and film strength of the obtained abrasive layer were extremely weak, and if the substrate material etc. were bent, the coating film would be peeled off, and the polyethylene foam layer could not be laminated.

Table 5-12 shows the results of the following evaluations on the polishing pads obtained in Examples 9-10, Reference Examples 1-2, and Comparative Examples 1-4.

(Evaluation of grinding properties)

As a polishing device, SPP600S manufactured by Okamoto Industrial Machinery Co., Ltd. was used, and the polishing characteristics were evaluated. An interferometric film thickness measuring device manufactured by Taitaku Electronics Co., Ltd. was used for the measurement of the oxide film thickness. Regarding the grinding conditions, as the liquid medicine, use a solution that is added to ultrapure water at a flow rate of 150ml/min and added KOH to make the pH 11 during the grinding process. Slurry—SemiSperse-12. The polishing load was 350 g/cm ² , the polishing fixed plate rotation speed was 35 rpm, and the wafer rotation speed was 30 rpm.

(Evaluation of Polishing Rate Characteristics)

A thermal oxide film of 0.5 μm was deposited on an 8-inch silicon dioxide wafer, and after predetermined patterning was performed, an oxide film of 1 μm was deposited with p-TEOS to obtain a patterned wafer with an initial step difference of 0.5 μm. The wafer was polished under the above-mentioned conditions, and after polishing, each level difference was measured to evaluate planarization characteristics. As planarization characteristics, two steps were evaluated. One is the local level difference, which is the level difference of a pattern in which lines with a width of 270 μm are arranged at a distance of 30 μm, and the other is the amount of cutting from the bottom portion of a pattern in which lines with a width of 30 μm are arranged at a distance of 270 μm. In addition, the average value of the said 270-micrometer line part and the 30-micrometer line part was made into the average polishing rate.

(scratch evaluation)

Using a wafer surface inspection device WM2500 manufactured by Topcon Corporation, the number of scratches of 0.2 μm or more on the oxide film surface of the polished 6-inch silicon wafer was evaluated.

Table 5-12

The polishing pad of the present invention can be used as an optical material for semiconductor devices such as silicon wafers, storage disks, magnetic disks, optical lenses, or reflectors, glass plates, and metals that require a high degree of surface flatness at a stable and high polishing rate. The material is used as a polishing pad for planarization processing. The polishing pad of the present invention is particularly suitable for use in a step of planarizing silicon wafers and devices (multilayer substrates) on which oxide layers, metal layers, etc. are formed, before lamination and formation of these layers. The cushion layer of the present invention can be used as a cushion layer of the above-mentioned polishing pad. Furthermore, since the polishing pad of the present invention contains abrasive grains in the polishing pad, it is not necessary to use expensive slurry for polishing, and low-cost processing can be provided. In addition, the abrasive grains in the pad do not aggregate, making scratches less likely to occur. Thus, according to the present invention, a polishing pad having a high polishing rate and excellent flatness and uniformity of polishing properties can be obtained.

Claims (24)

1, a kind of grinding pad, has the grinding layer that in resin, is dispersed with abrasive particle, it is characterized in that, the main chain of described resin is the polyester that contains 60 moles of above aromatic dicarboxylic acids of % in total carboxylic acid composition, and the side chain of described resin is the polymer that contains hydrophily functional group's free radical polymerization monomer.

2, a kind of grinding pad, has the grinding layer that in resin, is dispersed with abrasive particle, it is characterized in that, the main chain of described resin is with the polyester that contains 60 moles of above aromatic dicarboxylic acids of % in the total carboxylic acid composition polyester-polyurethane as main constituent, and the side chain of described resin is the polymer that contains hydrophily functional group's free radical polymerization monomer.

3, grinding pad according to claim 1 and 2 is characterized in that, the proportion that forms the resin of grinding layer is 1.05～1.35 scopes, and glass transition temperature is more than 10 ℃.

4, grinding pad according to claim 1 and 2 is characterized in that, the resin that forms grinding layer is to be that resin and the mixed with resin below 30 ℃ more than 60 ℃ forms with glass transition temperature.

5, grinding pad according to claim 1 and 2 is characterized in that, the average grain diameter of abrasive particle is 5～1000nm.

6, grinding pad according to claim 1 and 2 is characterized in that, abrasive particle is at least a kind that is selected from silica, cerium oxide, aluminium oxide, zirconia, iron oxide, chromium oxide and the diamond.

7, grinding pad according to claim 1 and 2 is characterized in that, the abrasive particle content in the grinding layer is 20～95 weight %.

8, grinding pad according to claim 1 and 2 is characterized in that, contains bubble in the grinding layer.

9, grinding pad according to claim 8 is characterized in that, the average diameter of bubble is 10～100 μ m.

10, grinding pad according to claim 1 and 2 is characterized in that, described grinding layer is formed on the polymeric substrate.

11, grinding pad according to claim 10 is characterized in that, described polymeric substrate is polyester thin plate, acrylic sheet, ABS resin thin plate, Merlon or vinyl chloride resin thin plate.

12. grinding pad according to claim 1 and 2 is characterized in that, the thickness of described grinding layer is 10～500 μ m.

13, grinding pad according to claim 10 is characterized in that, has, in the structure that is formed with the cushion that is laminated with the material softer than grinding layer on the polymeric substrate of grinding layer.

14, grinding pad according to claim 13 is characterized in that, cushion is below 60 with A Si card C hardness.

15, according to claim 13 or 14 described grinding pads, it is characterized in that stacked cushion is the nonwoven of polyester fiber, polyester non-woven fabric, polyurethane resin foaming body or the polyethylene resin foaming body of dipping polyurethane resin in this nonwoven.

According to claim 13 or 14 described grinding pads, it is characterized in that 16, the thickness of grinding layer is 250 μ m～2mm.

17, grinding pad according to claim 10 is characterized in that, the bonding strength between grinding layer and the polymeric substrate is when carrying out the crosscut test, and extant number is more than 90.

18, according to claim 13 or 14 described grinding pads, it is characterized in that polymeric substrate and cushion fit together with bonding agent or two-sided tape.

According to claim 13 or 14 described grinding pads, it is characterized in that 19, the adhesive strength of polymeric substrate and cushion has the intensity more than the 600g/cm in 180 degree disbonded tests.

20, grinding pad according to claim 1 and 2 is characterized in that, is formed with groove at grinding layer.

21, grinding pad according to claim 20 is characterized in that, groove is a clathrate.

22, grinding pad according to claim 20 is characterized in that, the separation of groove is below the 10mm.

23, grinding pad according to claim 20 is characterized in that, groove is a concentric circles.

24, grinding pad according to claim 20 is characterized in that, the degree of depth of groove is more than the 300 μ m.

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