CN111989618A - Polyester film for dry film resist - Google Patents

Abstract

A polyester film for dry film resist which has excellent flatness and transparency, has excellent sliding properties, can be wound in a roll shape with little variation in thickness in the film width direction, and can prevent air from being trapped between the films, and is a novel polyester film for DFR characterized in that it comprises a polyester film for dry film resist having a particle-containing surface layer on at least one side of a base polyester film having an intrinsic viscosity of 0.65dl/g or more, the base polyester film comprises particles having an average particle diameter of 0.030 to 0.200 [ mu ] m in a mass ratio of 10 to 7000ppm, and is a single layer formed of a polyester layer (referred to as "A layer") substantially not containing particles having an average particle diameter of 0.300 [ mu ] m or more or a multi-layer film having the A layer on the surface thereof, and the particle-containing surface layer comprises particles having an average particle diameter of 0.005 to 0.150 [ mu ] m.

Description

Polyester film for dry film resist

technical field

The present invention relates to a polyester film used for formation of a dry film resist (hereinafter, abbreviated as "DFR" in some cases), particularly a polyester film that can be suitably used as a support film constituting the dry film resist.

Background technique

A dry film resist (DFR) is widely used as a resist layer for forming wiring patterns of electronic circuit boards.

Dry film resist (DFR) is usually a lamination of a support film (also called a "carrier film") / a photoresist layer made of a photosensitive resin material / a protective film (also called a "cover film") 3 layers.

As a method of manufacturing an electronic circuit board using such DFR, for example, first, a protective film is peeled off from the DFR to expose a photoresist layer, and the above-mentioned photoresist layer is superimposed on the surface of the copper layer of an epoxy resin substrate on which, for example, a copper layer is laminated. After the resist layer and DFR are attached, a support film is stacked on the glass plate on which the circuit is printed, the DFR is brought into close contact, and light is irradiated from the glass plate side.

The light is transmitted through the transparent portion and the supporting film layer in the image of the circuit printed on the glass plate, and then irradiated to the photoresist layer, and the irradiated position of the photoresist layer is cured by the light.

Next, after removing the glass plate and the support film, the uncured portion of the photoresist layer is removed and etched using acid or the like.

At this time, the copper layer at the corresponding position is exposed by removing the uncured portion of the photoresist layer, the exposed copper layer is removed from the epoxy resin substrate by etching, and a circuit is formed on the epoxy resin substrate.

Then, by removing the cured photoresist layer, an electronic circuit board can be produced.

As the support film used for the formation of DFR, polyester films are mainly used because they are excellent in mechanical properties, optical properties, chemical resistance, heat resistance, dimensional stability, flatness, and the like.

Regarding such a polyester film, for example, Patent Document 1 discloses a biaxially oriented laminated polyester film in which particles having an average particle diameter of 0.01 to 3.0 μm are contained in the outermost layer on at least one side, and the centerline of the outermost layer is 0.01 to 3.0 μm. The average roughness Ra is 0.005 μm or more, the maximum height Rt is less than 1.5 μm, and the haze value is set to 1.5% or less.

Patent Document 2 discloses the following laminated polyester film for dry film resist as a laminated polyester film for dry film resist which is excellent in windability, can more reliably prevent the occurrence of circuit defects, and further improves resolution Film: it comprises at least two polyester layers, the number of metal-containing aggregates with a major diameter of 10 μm or more is 5 pieces/10 cm ² or less, and at least one outermost layer contains particles with an average particle diameter of 0.01 to 3.0 μm , the centerline average roughness Ra of the surface is 0.002 to 0.030 μm, and the maximum height Rt is 0.05 to 1.0 μm.

Patent Document 3 discloses a biaxially oriented polyester film for a dry film resist support, wherein the number of pit defects with a depth of 0.5 μm or more is 5 pieces/m ² or less, and the F-5 value in the longitudinal direction is 70 ～150MPa, F-5 value in width direction is 80～160MPa, haze value is 1% or less, thermal shrinkage at 150°C for 30 minutes is 1.5～3.5% in longitudinal direction and 0.5～2.5 in width direction %.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application Laid-Open No. 7-333853

Patent Document 2: Japanese Patent Laid-Open No. 2005-77646

Patent Document 3: Japanese Patent Laid-Open No. 2008-239743

SUMMARY OF THE INVENTION

Invention to solve problem

In recent years, circuits formed by miniaturization of electronic devices are extremely complex, lines are thin, and spaces between them are narrow, and DFR is required to improve image formation reproducibility and resolution.

In DFR, since light is irradiated to the photoresist layer through the support film for exposure, if the transparency of the support film is low, the photoresist layer will not be sufficiently exposed, and if the haze value of the film is If it is high or the surface is rough, problems such as resolution deterioration may occur due to scattering of light on the surface and inside of the film.

Therefore, the support film constituting the DFR is required to have a flatter surface and higher transparency.

However, when the flatness of the film is increased, the sliding property of the film is deteriorated, and the handling property is deteriorated, and it may become difficult to wind up in a roll shape.

Furthermore, when the flatness is improved, when thickness unevenness occurs in the width direction of the film, air tends to accumulate, which also causes wrinkles.

In order to make the handleability and winding characteristics of such a film good, it is conceivable to include particles in the polyester film to form fine protrusions on the surface.

However, when the protrusions are formed by particle addition, the scattering of ultraviolet rays by the protrusions and the generation of depressions on the surface of the resist layer are likely to cause a reduction in resolution, defects, or defects in the circuit formation of ultrafine lines. The transparency of the film is reduced.

As described above, a method for obtaining a film for DFR satisfying all of transparency, flatness, sliding property, and further thickness uniformity in the width direction has not yet been found.

Therefore, the present invention relates to a polyester film used in the formation of DFR, particularly a polyester film suitable for use as a support film, and an object of the present invention is to provide a novel polyester film for dry film resist which can not only achieve high flatness The film has good slidability, good transparency and film, has little thickness variation in the width direction of the film, can be wound into a roll, and at this time, air can be prevented from being trapped between the films.

solution to the problem

The present invention provides a polyester film for dry film resist, which is a dry film resist having a particle-containing surface layer on at least one side of a base polyester film having an intrinsic viscosity of 0.65 dl/g or more Etching polyester film,

The aforementioned base polyester film contains particles with an average particle diameter of 0.030 to 0.200 μm in a mass ratio of 10 to 7000 ppm, and is a polyester layer (also referred to as “A layer”) that does not substantially contain particles with a particle diameter of 0.300 μm or more. ”) or a multilayer film having the A layer on the surface, wherein the particle-containing surface layer contains particles with an average particle diameter of 0.005 to 0.150 μm.

effect of invention

Since the polyester film for dry film resist proposed by the present invention has a high intrinsic viscosity of the base polyester film, the stretching ratio, especially the stretching ratio in the width direction can be increased, and the thickness unevenness in the width direction of the film can be reduced. .

As a result, the thickness of the film can be made uniform, and the generation of wrinkles can be reduced by preventing the accumulation of air when the film is wound into a roll shape.

Furthermore, the polyester film for dry film resist proposed by the present invention includes a polyester layer (layer A) containing particles having an average particle diameter of 0.030 to 0.200 μm at a mass ratio of 10 to 7000 ppm, and has a The particle-containing surface layer of particles of 0.005 to 0.150 μm can not only achieve high flatness and transparency, but also improve the slipperiness of the film, so that it can be wound into a roll shape.

In addition, scratches on the film can be reduced, and when used as a support film constituting a dry film resist, the problem of inhibiting curing of the resist can be eliminated.

Detailed ways

Next, the present invention will be described based on an embodiment example. However, the present invention is not limited to the embodiments described below.

[this polyester film]

The polyester film for dry film resists (referred to as "this polyester film") as an example of an embodiment of the present invention is a polyester film provided with a particle-containing surface layer on at least one side of a base polyester film.

<This base polyester film>

The base polyester film constituting the present polyester film (referred to as "the present base polyester film") preferably contains polyester as a main component resin, and preferably contains an average particle diameter of 0.030 to 0.030 ppm in a mass ratio of 10 to 7000 ppm. Particles of 0.200 μm, a single layer formed of a polyester layer (layer A) substantially free of particles having a particle diameter of 0.300 μm or more, or a multilayer having the layer A on the surface, specifically two or three layers , 4-layer or more multi-layered film.

When the base polyester film is a multi-layered film having an A layer on the surface, it is preferable that the main component resin of each layer in the layers other than the A layer is polyester, and among them, a polymer resin with the main component resin of the A layer is particularly preferable. The same polyester as the ester. The polyester will be described later.

In this case, "main component resin" means the resin with the highest content among the resins constituting each layer, and specifically means that the content of the resin in each layer is 50 mass % or more, more preferably 80 mass % or more, and particularly preferably 90 mass % %above.

When the base polyester film is a multi-layered film including a layer A on the surface, specific examples include A layer/B layer including a polyester layer (also referred to as a "B layer") as a main layer, A layer/B layer/A layer, etc. A layer/B layer/C layer, A layer/B layer/C layer/A layer etc. which are further provided with different polyester layers (it is also called "C layer") are also mentioned. However, it is not limited to these.

(A floor)

The layer A contains the polyester described later as a main component resin, and contains particles having a particle diameter of 0.030 to 0.200 μm at a mass ratio of 10 to 7000 ppm, and is a polyester layer substantially free of particles having a particle diameter of 0.300 μm or more.

When the A layer of the polyester film of the present base material constituting a single layer, or the A layer of the single surface layer or the two surface layers of the polyester film of the present base material does not contain such particles, the handleability is deteriorated. Not only that, the production of polyester film. During the film process it is possible to introduce multiple scratches on the film surface.

As described above, light is irradiated on the resist layer through the support film for exposure. Therefore, when foreign matter or scratches are present in the support film of DFR, the portion is not exposed and a circuit defect occurs.

Therefore, when considering the use of the present polyester film as a support film for DFR, it is particularly preferable that the A layer forming the surface of the present base polyester film contains particles.

The average particle diameter of the particles contained in the A layer is preferably in the range of 0.030 μm to 0.200 μm.

If the average particle diameter of the particles is 0.200 μm or less, the transparency of the film will not be hindered. On the other hand, if the average particle diameter of the particles is 0.030 μm or more, the surface of the film can be appropriately roughened, and the handleability is not only improved. It is good, and the introduction of scratches on the film surface can be suppressed in the film forming process of the polyester film of the present base material.

From this viewpoint, the average particle diameter of the particles contained in the A layer is preferably 0.030 μm to 0.200 μm, and particularly preferably within a range of 0.040 μm or more or 0.150 μm or less, particularly preferably within a range of 0.050 μm or more or 0.100 μm or less.

Therefore, the average particle diameter of the particles contained in the A layer is preferably 0.030 μm to 0.150 μm or 0.030 μm to 0.100 μm, more preferably 0.040 μm to 0.200 μm, 0.040 μm to 0.150 μm, or 0.040 μm to 0.100 μm, and particularly preferred among them It is 0.050 μm to 0.200 μm, 0.050 μm to 0.150 μm, or 0.050 μm to 0.100 μm.

In addition, the average particle diameter of the particle|grains in each layer can be calculated|required as the average value by measuring the diameter of 10 or more particles with a scanning electron microscope (SEM). At this time, in the case of non-spherical particles, the average value of the longest diameter and the shortest diameter can be measured as the diameter of each particle.

Furthermore, it is preferable that the A layer does not substantially contain particles having a particle diameter of 0.300 μm or more, from the viewpoints of maintaining light transmittance during exposure, eliminating circuit defects after exposure, and the like.

In this case, "substantially not containing" means not containing intentionally, and specifically means that the content (mass) of the particles is 200 ppm or less, more preferably 150 ppm or less.

Furthermore, it is preferable that the A layer contains particles having an average particle diameter of 0.030 μm to 0.200 μm as described above in a mass ratio (also referred to as “concentration”) of 10 to 7000 ppm.

In the layer A, when the content (particle concentration) of particles having an average particle diameter of 0.030 μm to 0.200 μm is 7000 ppm or less, the transparency of the film can be improved. On the other hand, when the content of particles having an average particle diameter of 0.030 μm to 0.200 μm When the (particle concentration) is 10 ppm or more, the film surface can be appropriately roughened, and not only the handleability is improved, but also scratches can be suppressed from being introduced on the film surface during the film forming process of the polyester film of the present base material.

From this viewpoint, the A layer preferably contains particles with an average particle diameter of 0.030 μm to 0.200 μm in a mass ratio of 10 to 7000 ppm, and more preferably 100 ppm or more or 6000 ppm or less, especially 500 ppm or more or 5000 ppm or less, especially 1000 ppm or more or 4000 ppm. the following.

Therefore, the A layer preferably contains particles with an average particle diameter of 0.030 μm to 0.200 μm in a mass ratio of 10 to 6000 ppm, 10 to 5000 ppm, or 10 to 4000 ppm, and more preferably 100 to 7000 ppm, 100 to 6000 ppm, and 100 to 5000 ppm. or 100 to 4000 ppm by mass, more preferably 500 to 7000 ppm, 500 to 6000 ppm, 500 to 5000 ppm or 500 to 4000 ppm by mass, particularly preferably 1000 to 7000 ppm, 1000 to 6000 ppm, 1000 to 5000 ppm Or 1000-4000 ppm mass ratio is included.

The material of the particles contained in the layer A is not particularly limited as long as the particles have an average particle diameter of 0.030 to 0.200 μm. For example, inorganic particles such as calcium carbonate, calcium phosphate, silica, kaolin, talc, titanium dioxide, alumina, barium sulfate, calcium fluoride, lithium fluoride, zeolite, and molybdenum sulfide, ion exchange resins, and cross-linked polymers can be mentioned. , organic particles such as calcium oxalate, and precipitation particles generated during polyester polymerization.

The particles contained in the layer A may be one type or two or more types, and the same type of particles and particles having different particle diameters and particle shapes may be used together.

In addition, the shape of the above-mentioned particles may be any of a spherical shape, a block shape, a rod shape, a flat shape, and other shapes.

From the viewpoint of transparency and the like, the thickness of the A layer is preferably 0.1 to 20.0 μm, more preferably 0.3 μm or more or 10.0 μm or less, especially 0.5 μm or more or 5.0 μm or less.

In addition, from the viewpoint of flatness, the ratio of the layer thickness (μm) of the A layer to the average particle diameter (μm) of the particles contained in the A layer is preferably 0.5 to 400, preferably 5 or more or 100 or less, and further It is preferably 10 or more or 50 or less.

(layer B)

The polyester film of the base material preferably includes a polyester layer (layer B) as a main layer in addition to the above-mentioned layer A. In this case, in order to suppress cost and improve transparency, layer B is preferably substantially free of particles or at least in a ratio of Layer A contains particles at a low concentration.

In this case, the "main layer" refers to the layer with the largest thickness among them when the base polyester film includes other layers than the A layer.

In addition, the above-mentioned "substantially not containing" means not containing intentionally, and specifically means that the content of particles (particle mass concentration) is 200 ppm or less, more preferably 150 ppm or less.

The polyester used as the main component resin of the B layer is preferably the same polyester as the polyester used as the main component resin of the A layer.

When the B layer contains particles, the average particle diameter of the particles contained in the B layer is preferably smaller than the average particle diameter of the particles contained in the A layer, more preferably 0.010 μm to 0.200 μm, in order to reduce the cost and improve the transparency as described above. It is preferably 0.012 μm or more or 0.100 μm or less, particularly 0.015 μm or more or 0.080 μm or less.

In addition, from the viewpoints of maintaining light transmittance during exposure, eliminating circuit defects after exposure, and the like, it is also preferable that the B layer, like the A layer, does not substantially contain particles having a particle diameter of 0.300 μm or more.

Furthermore, as described above, in order to suppress cost and improve transparency, the particle concentration in the B layer is preferably at least lower than the particle concentration in the A layer. In particular, it is 1000 ppm or less, especially 500 ppm or less, and most preferably 100 ppm or less.

In addition, the kind, shape, etc. of the particles contained in the B layer are the same as those in the A layer.

The thickness of the layer B is preferably 0.1 to 40.0%, more preferably 1.0% or more or 20.0% or less, especially 3.0%, with respect to the thickness of the B layer, from the viewpoints of improving transparency and reducing costs, etc. above or below 10.0%.

(layer C)

As described above, when the base polyester film includes the C layer in addition to the A layer and the B layer, the C layer preferably includes polyester as a main component resin, and preferably contains particles at a concentration lower than that of the A layer. Alternatively, it may be a layer containing particles in the same manner as the A layer and having a different thickness from the A layer.

In addition, the kind and particle shape of the particles in the C layer are the same as those in the A layer.

The thickness of the C layer is preferably 1 to 300% of the thickness of the A layer from the viewpoints of improving transparency and reducing cost, and more preferably 10% or more or 200% or less, especially 20% or more. or below 150%.

(polyester)

The polyester that forms the main component resin of each layer of the polyester film of the present substrate is not particularly limited as long as it is a polyester obtained from an aromatic dicarboxylic acid or its ester and diol as main starting materials. Among them, polyesters having 60% or more of repeating structural units having ethylene terephthalate units or 2,6-naphthalenedicarboxylate units are preferred.

Moreover, this polyester may contain the 3rd component other than ethylene terephthalate unit and 2, 6- ethylene naphthalate unit as a copolymerization component or a mixed component. For example, a resin compatible with polyester-based resins such as polycarbonate can be mixed.

Examples of the above-mentioned aromatic dicarboxylic acid components include terephthalic acid, dimethyl terephthalate, 2,6-naphthalenedicarboxylic acid, isophthalic acid, phthalic acid, and adipic acid. , sebacic acid, etc. Particular preference is given to terephthalic acid or dimethyl terephthalate.

As an example of the said glycol component, 1 type or 2 or more types, such as ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, are mentioned, for example. Ethylene glycol is particularly preferred.

When the said polyester is a copolyester, as the dicarboxylic acid component, for example, 1 of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, and sebacic acid can be mentioned. One or two or more kinds, and as the diol component, for example, one or more of ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, etc. can be mentioned. 2 or more.

(This base polyester film)

It is preferable that the intrinsic viscosity of this base polyester film is 0.65 dl/g or more.

If the intrinsic viscosity of the polyester film of the present base material is 0.65 dl/g or more, the stretching can be performed even if the stretching ratio, especially the stretching ratio in the width direction (lateral direction), is increased to 4.0 times or more, as described later. Since no breakage occurs, the thickness unevenness of the film in the width direction can be reduced, and the generation of wrinkles can be reduced by suppressing the accumulation of air when the film is wound into a roll shape.

From this viewpoint, the intrinsic viscosity of the polyester film of the present base material is preferably 0.65 dl/g or more, more preferably 0.65 dl/g or more or 0.90 dl/g or less, particularly 0.66 dl/g or more or 0.80 dl/g. the following.

The intrinsic viscosity of the base polyester film can be adjusted by appropriately changing the polymerization conditions of the polyester as the main component resin. For example, if the polymerization time is prolonged or the molecular weight is increased by solid phase polymerization, the intrinsic viscosity can be increased.

In addition, when this base material polyester film is laminated|stacked, the said intrinsic viscosity means the intrinsic viscosity of all layers of a film.

The polyester film of the base material may be a non-stretched film (sheet) or a stretched film. Among them, a stretched film is preferable, and a biaxially stretched film is more preferable.

When the laminated polyester film is a biaxially stretched film, it may be a successive biaxially stretched film or a simultaneous biaxially stretched film.

From the viewpoint of handleability and economy, the thickness of the base polyester film is preferably 6 μm to 63 μm, more preferably 9 μm or more or 38 μm or less, especially 12 μm or more or 25 μm or less.

<Particle-containing surface layer>

This polyester film may have a structure in which a particle-containing surface layer is laminated on only one side of a base polyester film, or a structure in which particle-containing surface layers are laminated on both sides of the base polyester film.

Furthermore, another layer may be laminated between the base polyester film and the particle-containing surface layer, or on the surface of the particle-containing surface layer.

In addition, when the base polyester film is composed of two layers, the A layer and the B layer, when the particle-containing surface layer is formed on only one side of the base polyester film, it is preferable to form the B layer on the opposite side of the A layer. The layer side forms a particle-containing surface layer.

The particle-containing surface layer preferably contains particles having an average particle diameter of 0.005 to 0.150 μm.

When the average particle diameter of the particles contained in the particle-containing surface layer is 0.005 μm or more, the sliding properties and winding properties of the film can be maintained appropriately, and when the average particle diameter is 0.150 μm or less, it becomes difficult for the particles to escape from the particle-containing surface layer. It is preferable that the particle-containing surface layer is not easily ground.

From this viewpoint, the particle-containing surface layer preferably contains particles having an average particle diameter of 0.005 to 0.150 μm, and preferably contains particles of 0.010 μm or more or 0.120 μm or less, particularly 0.030 μm or more or 0.100 μm or less.

Therefore, the particle-containing surface layer preferably contains particles of 0.005 to 0.120 μm or 0.005 to 0.100 μm, more preferably contains particles of 0.010 to 0.150 μm, 0.010 to 0.120 μm or 0.010 to 0.100 μm, and particularly preferably contains particles of 0.030 to 0.150 μm, Particles of 0.030 to 0.120 μm or 0.030 to 0.100 μm.

It should be noted that if the average particle diameter of the particles contained in the particle-containing surface layer is within the above range, the particle-containing surface layer may contain particles with a particle size smaller than 0.005 μm or particles with a particle size larger than 0.150 μm.

The ratio of the average particle diameter of the particles contained in the particle-containing surface layer to the average particle diameter of the particles contained in the A layer is preferably 0.02 to 10, among them, 0.1 or more or 5 or less, especially 0.3 or more or 3 or less, and the particle-containing layer is further preferably The average particle diameter of the particles contained in the surface layer is larger than the average particle diameter of the particles contained in the A layer.

By making the said ratio satisfy the predetermined range, the flatness of the A layer and the slipperiness of the particle-containing surface layer can be satisfied at the same time, and a more suitable film for DFR can be obtained.

The average particle diameter of the particles in the particle-containing surface layer can be obtained by measuring the diameters of 10 or more particles with a scanning electron microscope (SEM) and obtaining the average value thereof. At this time, in the case of non-spherical particles, the average value of the longest diameter and the shortest diameter can be measured as the diameter of each particle.

The particle concentration in the particle-containing surface layer is preferably 1 to 10% by mass.

When the particle concentration in the particle-containing surface layer is 1 mass % or more, the effect of improving slipperiness and coiling can be imparted. On the other hand, when it is 10 mass % or less, the particles become less likely to aggregate and fall off from the particles can be reduced. The resulting grinding of the particle-containing surface layer is not easy to hinder the light transmission of the DFR film, and it is not easy to generate circuit defects.

From this viewpoint, the particle concentration in the particle-containing surface layer is preferably 1 to 10 mass %, and more preferably 2 mass % or more or 7 mass % or less, especially 2 mass % or more or 5 mass % or less.

The ratio of the particle concentration (mass %) in the particle-containing surface layer to the particle concentration (mass %) in the A layer is preferably 1 to 10,000, preferably 5 or more or 1,000 or less, especially 10 or more or 100 or less.

By making the said ratio satisfy the predetermined range, the flatness of the A layer, the scratch resistance, and the slipperiness of the particle-containing surface layer can be simultaneously satisfied, and a more suitable film for DFR can be obtained.

The types and shapes of the particles in the particle-containing surface layer are the same as those described for the particles contained in the A layer. Among them, inorganic particles, especially silica particles, are preferred.

(Antistatic agent)

The particle-containing surface layer preferably further contains an antistatic agent.

When the support film laminated on the photoresist layer is peeled off, due to static electricity generated by the peeling electrification, foreign substances such as dirt and dust are attracted to the photoresist layer and adhere to the photoresist layer, and the pattern of the circuit may be irregular. Therefore, it is preferable to provide a support. Antistatic properties when the film is peeled off.

By containing an antistatic agent in the particle-containing surface layer, the polyester film can be made into a dry film resist for high resolution with high flatness, releasability and antistatic properties on the surface in contact with the photoresist layer. Agent support film.

Examples of the antistatic agent used in the particle-containing surface layer include ion-conductive polymer compounds such as ammonium group-containing compounds, polyether compounds, sulfonic acid compounds, and betaine compounds, polyacetylene, polyphenylene, polyaniline, and polypyrrole. , Polyisothianaphthene (poly(isothianaphthene)), polythiophene and other π-electron conjugated polymer compounds. In addition, a polyether compound is an antistatic agent, and also corresponds to the synthetic wax which is the said mold release agent.

Among these, ion-conductive polymer compounds are preferred, and ammonium group-containing compounds are particularly preferred. The particle-containing surface layer formed from a coating liquid containing a π-conjugated conductive polymer such as polythiophene and polyaniline is usually strongly colored. The thin film for DF preferably has high transparency (low haze), and therefore, the π-conjugated conductive polymer may not be suitable.

In addition, since the π-conjugated conductive polymer paint is generally more expensive than the ion-conductive paint, an ion-conductive antistatic agent can also be suitably used from the viewpoint of production cost.

As the above-mentioned ammonium group-containing compound, a polymer compound having an ammonium group is preferable. For example, a polymer containing a monomer having an ammonium group and an unsaturated double bond as a component can be used.

As a specific example of the said polymer, the polymer which has the structural element represented by following formula (1) as a repeating unit is mentioned, for example. It can be a homopolymer or a copolymer obtained by copolymerizing other various components.

In the above formula (1), R ¹ and R ² are each independently a hydrogen atom, an alkyl group, a phenyl group, or the like, and these alkyl groups and phenyl groups may be substituted with the groups shown below.

Substitutable groups are, for example, hydroxyl, amide, ester, alkoxy, phenoxy, naphthyloxy, thioalkoxy, thiophenoxy, cycloalkyl, trialkylammonium alkyl, cyano, halogen, etc. In addition, R ¹ and R ² may be chemically bonded, and examples thereof include -(CH ₂ ) _m - (m=an integer of 2 to 5), -CH(CH ₃ )CH(CH ₃ )-, and -CH=CH -CH=CH-, -CH=CH-CH=N-, -CH=CH-N=C-, -CH ₂ OCH ₂ -, -(CH ₂ ) ₂ O(CH ₂ ) ₂ - and the like.

In the case of a polymer having the constituent element represented by the above formula (1) as a repeating unit, from the viewpoint of improving the compatibility with other materials, improving the transparency of the obtained coating film, and further improving the releasability, It is preferably copolymerized with other repeating units. Examples of other repeating units include alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. Alkyl methacrylates such as esters, and acrylamides such as N-methylol acrylamide.

X ^- in the said formula (1) can be suitably selected in the range which does not impair the gist of this invention. For example, a halogen ion, a sulfonate group, a phosphate group, a nitrate group, an alkylsulfonate group, a carboxylate group, etc. are mentioned.

In addition, since the structure becomes soft and a particle-containing surface layer excellent in uniformity can be obtained during in-line coating, it is preferable to combine the component represented by the formula (1) with a polyethylene glycol-containing (meth)acrylate copolymerized polymer.

The number average molecular weight of the antistatic agent contained in the particle-containing surface layer is preferably 1,000 to 500,000, more preferably 2,000 or more or 350,000 or less, especially 5,000 or more or 200,000 or less.

When the number average molecular weight of the antistatic agent is 1,000 or more, the strength of the coating film can be maintained, the heat resistance stability can also be maintained, and sufficient antistatic properties can be provided. In addition, when the molecular weight is 500,000 or less, the viscosity of the coating liquid can be prevented from increasing, the handleability and coating properties can be maintained well, and it is suitable as a film for DFR.

(wax)

The particle-containing surface layer preferably contains wax in order to improve the slipperiness of the film.

In this case, it may be contained together with the above-mentioned antistatic agent, or the wax may be contained without the above-mentioned antistatic agent.

Examples of waxes that the particle-containing surface layer may contain include natural waxes such as vegetable waxes, animal waxes, mineral waxes, and petroleum waxes, synthetic hydrocarbons, synthetic waxes such as modified waxes, and hydrogenated waxes.

Among them, polyolefin-based compounds are preferred. Specifically, for example, a compound having a polymer containing an unsaturated hydrocarbon such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene, or a compound such as a polyolefin-based compound of a copolymer as a basic skeleton is dissolved Or dispersed and used, polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, propylene-1 can be exemplified. -Butene copolymer, etc. More specifically, it is preferable to use a polyolefin having an acid value of 10 to 50 having an active hydrogen group at the terminal, and further oxidized polyethylene or oxidized polypropylene.

When a polymer-type wax is used, the number average molecular weight is preferably 2,000 to 20,000, and more preferably 3,000 to 15,000. Within such a range, film forming properties and mold releasability can be maintained.

In addition, the softening point is preferably 70 to 170°C, and among them, 90°C or higher or 150°C or lower is more preferable. Within such a range, film-forming properties and mold releasability can be maintained.

(crosslinking agent)

The particle-containing surface layer preferably further contains a crosslinking agent in order to improve the coating film strength of the particle-containing surface layer and impart abrasion resistance to the film.

As a crosslinking agent, a melamine compound, an oxazoline compound, an epoxy compound, an isocyanate type compound, a carbodiimide type compound etc. are mentioned, for example. Among these crosslinking agents, melamine compounds are preferred from the viewpoint of good coating film strength and excellent releasability of the particle-containing surface layer.

Moreover, these crosslinking agents can be used in combination of 2 or more types.

The above-mentioned melamine compound is a compound having a melamine skeleton in the compound, for example, an alkylolated melamine derivative, a compound partially or completely etherified by reacting an alcohol with an alkylolated melamine derivative, and a mixture thereof can be used. As the alcohol used for etherification, methanol, ethanol, isopropanol, n-butanol, isobutanol, etc. can be suitably used.

In addition, as the melamine compound, any of monomers, dimers or more may be used, or a mixture of these may be used.

Furthermore, what co-condensed urea etc. with a part of melamine can also be used, and a catalyst can also be used in order to improve the reactivity of a melamine compound.

As the above-mentioned oxazoline compound, an oxazoline group-containing polymer is particularly preferable, and it can be produced by polymerization of an addition polymerizable oxazoline group-containing monomer alone or with other monomers. Examples of the addition polymerizable oxazoline group-containing monomer include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl yl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2- An oxazoline etc. can use these 1 type or a mixture of 2 or more types.

The other monomer is not limited as long as it can be copolymerized with the addition polymerizable oxazoline group-containing monomer, and examples thereof include alkyl (meth)acrylate (as the alkyl group, methyl, ethyl, (meth)acrylates such as n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, cyclohexyl); acrylic acid, methacrylic acid, itaconic acid, maleic acid Unsaturated carboxylic acids such as acid, fumaric acid, crotonic acid, styrene sulfonic acid and its salts (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile ; (meth)acrylamide, N-alkyl (meth)acrylamide, N,N-dialkyl (meth)acrylamide (as alkyl, methyl, ethyl, n-propyl, isopropyl , n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, cyclohexyl, etc.) and other unsaturated amides; vinyl acetate, vinyl propionate and other vinyl esters; methyl vinyl ether, ethyl acetate Vinyl ethers such as vinyl ether; α-olefins such as ethylene and propylene; halogen-containing α,β-unsaturated monomers such as vinyl chloride and vinylidene chloride; α-olefins such as styrene and α-methylstyrene , β-unsaturated aromatic monomers, etc., one or more of these monomers can be used.

Examples of the above epoxy compound include condensates of epichlorohydrin with hydroxyl groups and amino groups such as ethylene glycol, polyethylene glycol, glycerin, polyglycerol, and bisphenol A, and examples include polyepoxy compounds, diepoxy compounds, mono Epoxy compounds, glycidylamine compounds, etc.

As said polyepoxy compound, sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglyceryl polyglycidyl ether, triglycidyl tris(2-hydroxyethyl ether) are mentioned, for example ) isocyanate, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, and examples of diepoxy compounds include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, Resorcinol Diglycidyl Ether, Ethylene Glycol Diglycidyl Ether, Polyethylene Glycol Diglycidyl Ether, Propylene Glycol Diglycidyl Ether, Polypropylene Glycol Diglycidyl Ether, Polytetramethylene Glycol Diglycidyl Ether , as the monoepoxy compound, for example, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and as the glycidylamine compound, N,N,N',N '-Tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylamino)cyclohexane, etc.

It should be noted that the cross-linking agent is preferably used in the drying process and the film-forming process so as to react to improve the performance of the particle-containing surface layer. It is presumed that unreacted products of these crosslinking agents, reacted compounds, or mixtures thereof are present in the finished particle-containing surface layer.

(binder)

The particle-containing surface layer may contain thermoplastics such as polyesters, polyurethanes, acrylic resins, polyvinyl resins, polyolefins, etc. Resins and/or thermosetting acrylic resins, melamine resins, thermosetting resins such as epoxy resins, and the like.

(content ratio)

The mass ratio of the particles contained in the particle-containing surface layer to the antistatic agent, wax, binder, and crosslinking agent that may be further contained in the particle-containing surface layer is preferably appropriately adjusted according to the compound selected, and the criteria are as follows.

The content of particles in the particle-containing surface layer (particle concentration) is preferably 1 mass % or more, and more preferably 2 mass % or more or 10 mass % or less.

When the content (particle concentration) of the particles in the particle-containing surface layer is 1 mass % or more, it becomes easy to obtain the effect of improving slippage and winding of the film for DFR, and when it is 10 mass % or less, the particles become It is not easy to aggregate, and can reduce the grinding of the particle-containing surface layer caused by the falling off of the particles, and it is difficult to hinder the light transmission of the film for DFR, and it becomes difficult to generate circuit defects.

The content of the antistatic agent in the particle-containing surface layer is preferably 5% by mass or more, and more preferably 10% by mass or more or 90% by mass or less.

When the antistatic agent is a polymer of a compound having an ionic functional group, it is preferably 15 to 90% by mass, and more preferably 20% by mass or more or 90% by mass or less.

By making content of an antistatic agent into the said range, sufficient surface resistivity can be achieved, and the film for DFR becomes difficult to electrostatically adhere.

The content of the wax in the particle-containing surface layer is preferably 1% by mass or more, and more preferably 2% by mass or more or 10% by mass or less. By making content of wax into the said range, it becomes easy to achieve a sufficient slippery effect, and it becomes difficult to inhibit the adhesiveness with a polyester film base material.

The content of the crosslinking agent in the particle-containing surface layer forming composition constituting the particle-containing surface layer is preferably 1% by mass or more, and more preferably 2% by mass or more or 50% by mass or less.

When the content of the crosslinking agent is 1 mass % or more, the effects of easy slippage and winding improvement of the DFR film are easily obtained, and when the content is 50 mass % or less, light transmission of the DFR film is less likely to be inhibited, and circuit defects are less likely to occur.

The content of the binder in the particle-containing surface layer is preferably 1% by mass or more, and more preferably 2% by mass or more or 60% by mass or less. Adhesion with a polyester film base material can fully be acquired by making content of a binder into the said range.

(other ingredients)

For the particle-containing surface layer, antifoaming agents, coatability improvers, thickeners, organic lubricants, antistatic agents, ultraviolet absorbers, antioxidants, foaming agents, dyes, pigments, etc. may be used in combination as necessary.

Analysis of the composition of the particle-containing surface layer can be performed by, for example, TOF-SIMS, X-ray photoelectron spectroscopy (XPS), fluorescent X-ray analysis, and the like.

(film thickness of particle-containing surface layer)

The film thickness of the particle-containing surface layer is preferably 0.001 μm to 0.5 μm, more preferably 0.005 μm or more or 0.3 μm or less, especially 0.01 μm or more or 0.2 μm or less.

When the film thickness of the particle-containing surface layer is 0.5 μm or less, the appearance of the coating film and the cured state of the coating film can be maintained, and when the film thickness is 0.001 μm or more, sufficient releasability can be obtained.

In addition, if the film thickness of the particle-containing surface layer is 0.001 to 0.5 μm, the surface roughness of the laminated polyester film will not be affected.

That is, the surface roughness of the film for dry film resist and the surface roughness of the laminated polyester film can be regarded as the same.

The ratio of the film thickness (μm) of the particle-containing surface layer to the average particle diameter (μm) of the particles contained in the particle-containing surface layer is preferably 0.005 to 100.

When the ratio is 0.005 or more, the particles can be prevented from falling off, and on the other hand, when it is 100 or less, the surface protrusions caused by the particles can be maintained, so that the sliding property can be further improved, and the windability and the like can be improved.

From this viewpoint, the ratio is preferably 0.005 to 100, among them, 0.01 or more or 10 or less, and more preferably 0.1 or more or 1 or less.

In addition, the ratio of the film thickness (μm) of the particle-containing surface layer to the layer thickness (μm) of the A layer is preferably 0.00005 to 5, preferably 0.001 or more or 1 or less, and more preferably 0.01 or more or 0.1 or less.

<The manufacturing method of this polyester film>

(Manufacturing method of the present base polyester film)

First, the manufacturing method of this base material polyester film is demonstrated.

For example, raw materials such as polyester resin are melted with an extruder, all layers of a die (for example, a T-die, etc.) are co-melt extruded from a nozzle onto a rotating cooling drum, quenched to produce an unstretched laminated film, and then an unstretched laminated film is produced. The unstretched laminated film can be produced by stretching in the longitudinal direction and the transverse direction, and heat-fixing as necessary.

At this time, the stretching ratio in the transverse direction, in other words, in the width direction, is preferably 4.0 times or more, and more preferably, the stretching ratio in the longitudinal direction is 2.5 times or more, if necessary.

The intrinsic viscosity of the polyester film of the present base material is 0.65 dl/g or more. Therefore, such high-magnification stretching, especially transverse stretching, can be performed without breakage, thickness unevenness can be reduced, and thickness can be made uniform. The generation of wrinkles can be suppressed by preventing the accumulation of air when it is wound into a roll shape.

An example of the manufacturing method of the polyester film of the present base material including three layers of A layer/B layer/A layer will be described. The same applies to the case of other laminated structures.

First, the polyester forming the A layer and the polyester forming the B layer are supplied to respective extruders, heated to a temperature equal to or higher than the melting point of each polyester, and melted respectively. Next, each polyester is extruded from the T-die in the form of a sheet so that each polyester is laminated in the order of A/B/A.

Next, the sheet was quenched on a rotating cooling drum below the glass transition temperature to obtain an amorphous unstretched film. In this case, in order to improve the flatness of the unstretched film, the adhesiveness between the unstretched film and the rotating cooling drum can be improved by electrostatic application method, liquid coating adhesion method, or the like.

Next, using a roll stretching machine, the unstretched film is stretched in the longitudinal direction (longitudinal stretching) to obtain a uniaxially stretched film. In this case, the stretching temperature is equal to or higher than the glass transition temperature of the polyester, preferably 70 to 150°C, and more preferably 75 to 130°C. In addition, the longitudinal stretching ratio is 2.5 times or more, more preferably 2.8 times or more or 4.0 times or less, especially 3.0 times or more or 3.5 times or less. At this time, the longitudinal stretching may be carried out in only one stage, or may be carried out in two or more stages.

Next, using a tenter stretching machine, the uniaxially stretched film is stretched in the width direction (laterally stretched) to obtain a biaxially stretched film. At this time, the stretching temperature is preferably 75 to 150°C, and more preferably 80 to 140°C. The lateral stretch ratio is 4.0 times or more, preferably 4.2 times or more or 6.0 times or less, particularly 4.4 times or more or 5.5 times or less, and more preferably 4.5 times or more or 5.0 times or less. At this time, lateral stretching may be performed in only one stage, or may be divided into two or more stages.

Next, the biaxially stretched film is heat-treated at a temperature of, for example, 150 to 250° C., thereby producing a laminated film.

When heat-treating the biaxially stretched film, the biaxially stretched film may be relaxed within 30% or the like.

Then, it can be rolled up into a roll shape as needed.

(formation of particle-containing surface layer)

The particle-containing surface layer can be formed by "on-line coating" in which the film surface is treated in the production process of the polyester film of the base material, or it can be formed on the polyester film of the base material temporarily produced outside the system. It is formed by performing "offline coating" of coating.

In-line coating is a method of coating in the production process of the polyester film of the present base material, and specifically, it is performed at any stage from the start of melt extrusion of polyester to after stretching and then heat-fixing and winding up method of coating.

Usually, it is applied to any of an unstretched sheet obtained by melting and quenching, a uniaxially stretched film after stretching, a biaxially stretched film before heat setting, and a film after heat setting and before rolling.

For example, in successive biaxial stretching, the method of applying to a uniaxially stretched film stretched in the longitudinal direction (longitudinal direction) and then stretching in the transverse direction is particularly excellent.

According to the method, film formation and particle-containing surface layer formation can be simultaneously performed, and therefore, there is an advantage in manufacturing cost.

In addition, since the stretching is performed after the coating, the film thickness of the particle-containing surface layer can be changed according to the stretching ratio, and the coating can be made into a thin film more easily than off-line coating.

In addition, by providing the particle-containing surface layer on the base polyester film before stretching, the particle-containing surface layer can be stretched together with the base polyester film. Thereby, the particle-containing surface layer can be firmly adhered to the polyester film of the present base material.

Furthermore, in the production of biaxially stretched polyester film, the film can be restrained in the longitudinal direction and the transverse direction by holding and stretching the end of the film with a clip or the like, and the flatness can be maintained in the heat setting process without introducing High temperature is applied in a wrinkled state.

Therefore, the heat treatment applied after coating can be set to a high temperature that cannot be achieved by other methods, so that the film-forming property of the particle-containing surface layer is improved, and the particle-containing surface layer and the base film can be adhered more firmly.

Furthermore, a firm particle-containing surface layer can be formed, and the performance and durability of the particle-containing surface layer can be improved. Therefore, as a method of forming a particle-containing surface layer on at least one side of a polyester film, a production method in which the coating liquid is applied to the polyester film and then stretched in at least one direction is preferred.

As a method for forming the particle-containing surface layer, for example, the particles and the antistatic agent, wax, binder, cross-linking agent and the like which may be contained in the particle-containing surface layer are dispersed or dissolved in a solvent to prepare a solution for the particle-containing surface layer. , and it can be formed by applying it to one side of the base polyester film.

The solution for the particle-containing surface layer is preferably formed by coating it on one side of the base polyester film as an aqueous coating solution (water-soluble resin or water-dispersible resin using water as a medium).

However, it can also be formed by applying an aqueous coating liquid containing a small amount of an organic solvent.

Examples of the organic solvent include alcohols such as ethanol, isopropanol, ethylene glycol, and glycerin, ethyl cellosolve, t-butyl cellosolve, ethers such as propylene glycol monomethyl ether and tetrahydrofuran, ketones such as acetone and methyl ethyl ketone, Esters such as ethyl acetate, amines such as dimethylethanolamine, etc. These can be used alone or in combination. In the aqueous coating liquid, these organic solvents are appropriately selected and contained as necessary, and can contribute to the stability of the coating liquid, coatability, or coating film properties.

As a coating method for applying the solution for the particle-containing surface layer to the polyester film of the base material, for example, a reverse roll coater, a gravure, as shown in "Coating Method" by Yuji Harazaki, Maki Shoten, published in 1979 can be used. A coater, a bar coater, an air doctor coater, or a coating device other than these.

In this polyester film, the drying and curing conditions for forming the particle-containing surface layer on the polyester film, for example, when the particle-containing surface layer is formed by off-line coating, are usually at 80 to 200° C. for 3 to 40 seconds, preferably at It is preferable to perform heat treatment at 100 to 180° C. for 3 to 40 seconds as a standard.

On the other hand, when the particle-containing surface layer is provided by in-line coating, it is generally preferable to perform heat treatment at 70 to 270° C. for 3 to 200 seconds.

In addition, regardless of off-line coating or in-line coating, active energy ray irradiation such as heat treatment and ultraviolet irradiation may be used in combination as necessary. Surface treatments such as corona treatment and plasma treatment may be performed in advance on the surface of the laminated polyester film constituting the present polyester film.

<this polyester film>

Next, the characteristic which this polyester film can have is demonstrated.

(Surface roughness)

The average surface roughness (Ra) of the surface of the polyester film is preferably in the range of 0.001 to 0.020 μm, more preferably 0.002 μm or more and 0.010 μm or less, especially 0.002 μm or more or 0.005 μm or less.

By making the surface roughness (Ra) of the present polyester film within the above-mentioned range, the transparency of the present polyester film is not impaired, and light scattering at the unevenness of the film surface is less likely to increase, so that exposure to ultraviolet (UV) rays can be suppressed. The reduction of the amount, the resolution is not easy to reduce.

It should be noted that, when the particle-containing surface layer is formed only on one side, it is preferably formed on the side opposite to the side where the photoresist layer is formed on the polyester film of the base material. Therefore, the surface of the polyester film of the base material is preferably formed. That is, the A layer has the above-mentioned average surface roughness (Ra).

Next, the same applies to Rt described below.

The average surface roughness (Rt) of the surface of the polyester film is preferably in the range of 0.010 to 0.400 μm, and more preferably 0.015 μm or more or 0.300 μm or less, especially 0.020 μm or more or 0.200 μm or less, especially 0.025 μm or more or within the range of 0.100 μm or less.

When the maximum surface roughness (Rt) of the surface of the polyester film is 0.400 μm or less, unevenness transfer to the photoresist layer can be prevented, and the problem of circuit breakage during fine-pitch circuit formation can be eliminated. On the other hand, if the maximum surface roughness (Rt) is 0.001 μm or more, or the maximum surface roughness (Rt) is 0.010 μm or more, it is suitable for the production process, especially in the film forming process. scars. Furthermore, it is preferable that the scratch transfer and exposure scattering to the photoresist layer due to the scratch are unlikely to occur, and the fine-pitch circuit pattern is unlikely to be affected.

(Haze)

The haze of the polyester film is preferably 1.0% from the viewpoint that the amount of exposure to ultraviolet rays is less likely to become insufficient, the desired circuit defect is unlikely to be caused, and the reduction in resolution can be suppressed when used for high-resolution DFR. Hereinafter, among them, it is more preferably 0.1% or more or 0.7% or less, especially 0.2% or more or 0.5% or less.

(Antistatic property)

The surface resistivity of the polyester film is preferably 2.0×10 ¹³ Ω/□ or less, and more preferably 1.0×10 ⁷ Ω/□ or more or 1.0×10 ¹² Ω/□ or less.

By setting the value of the surface resistivity of the polyester film to be 2.0×10 ¹³ Ω/□ or less, it is easy to control peeling electrification even when the DFR is wound into a roll shape.

Therefore, it is difficult to electrify, and spark discharge caused by peeling electrification can be suppressed. In addition, in the step of forming the photoresist layer, adhesion of dirt and dust due to electrification can be prevented, and formation defects of the photoresist layer and foreign matter defects after UV exposure can be prevented. In particular, in DFR requiring high resolution, there is a fear that even a small amount of foreign matter may become a defect in the circuit. Therefore, this problem can be suppressed.

By forming the particle-containing surface layer, the slipperiness can be improved, and by containing an antistatic agent in the particle-containing surface layer, the antistatic property can be further improved.

<How to use this polyester film>

This polyester film can be suitably used as a support film for a dry film resist. For example, a photosensitive laminate (for example, DFR) can be formed by laminating a photoresist layer on at least one side of the present polyester film as a support film, and by laminating with a protective film if necessary.

Therefore, the photosensitive laminated body (for example, DFR) which is an example of embodiment of this invention has the structure which laminated|stacked the photoresist layer on at least one side of this polyester film.

In this case, when the particle-containing surface layer is formed only on one side of the polyester film of the present base material, in order to form the DFR, the particle-containing surface layer is located on the side opposite to the surface where the photoresist layer is formed. The surface layer of the particle surface layer is the surface of the polyester film of the base material on the opposite side, that is, the layer A is in close contact with the photoresist layer, and it is preferable to laminate the present polyester film on the photoresist layer.

A photosensitive laminate (for example, DFR) generally has a laminated structure of a support film/photoresist layer/protective film. When the DFR is wound into a roll shape, the lower surface of the DFR, that is, the support film, is in contact with the protective film on the upper surface side.

Therefore, when the particle-containing surface layer exists on the surface in contact with the protective film, the effect of easy slippage becomes remarkable. In addition, since the particle-containing surface layer does not exist on the resist surface, the adhesion between the resist layer and the support film is less likely to change, and peeling failure is less likely to occur when the support film is removed from the resist layer.

The photoresist layer constituting the dry film resist is formed of a photosensitive resin material, and is cured by reacting with light such as ultraviolet rays.

Specific examples of the photosensitive resin material include alkali-soluble polymers such as carboxylic acid-containing vinyl copolymers, and ethylenically unsaturated addition polymerizable monomers such as 2-hydroxy-3-phenoxypropyl acrylate. , photopolymerization initiators such as benzil dimethyl ketal, etc.

The protective film constituting the photosensitive laminate (for example, DFR) is formed of polyolefin such as polyethylene and polypropylene, polyester, etc., and is laminated on the surface on the opposite side of the laminated film in the photoresist layer, thereby protecting the dry film resist.

<Description of statement, etc.>

"Sheet" generally refers to a flat article as defined in JIS, which is thin and whose thickness is small compared with length and width, and generally "film" is a thin film whose thickness is very small compared with length and width and whose maximum thickness is arbitrarily defined. And flat products, usually refers to the supply in the form of rolls (Japanese Industrial Standard JISK6900). However, the boundary between a sheet and a film is not defined, and there is no need to distinguish between the two in terms of language in the present invention. Therefore, in the present invention, the term "film" also includes "sheet", and the term "sheet" also includes "film". .

In addition, when expressed as a "panel" like an image display panel, a protection panel, etc., a board body, a sheet|seat, and a film are included.

In this specification, when it is described as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, it also includes "preferably more than X" or "preferably more than X" together with the meaning of "more than X and less than or equal to Y". less than Y" meaning.

In addition, when described as "more than X" (X is an arbitrary number), unless otherwise specified, the meaning of "preferably larger than X" is included, and when described as "Y or less" (Y is an arbitrary number), unless otherwise specified In the description, the meaning of "preferably smaller than Y" is also included.

Example

Hereinafter, the present invention will be described in further detail by way of examples. However, the present invention is not limited to the following examples as long as the gist is not exceeded.

<Material for forming base polyester>

In Examples and Comparative Examples, the following polyesters were used to prepare base polyesters (layers A and B).

(polyester resin I)

Using 100 parts by mass of dimethyl terephthalate and 60 parts by mass of ethylene glycol as starting materials, tetra-n-butyl titanate was added so that the content in terms of titanium atoms became 10 ppm mass concentration, and the reaction vessel was taken into the reactor. The reaction start temperature was set to 150°C, methanol was distilled off, the reaction temperature was gradually raised, and reached 230°C after 3 hours. After 4 hours, the transesterification reaction was substantially completed. The reaction mixture was transferred to a polycondensation tank, and a polycondensation reaction was carried out for 4 hours. Under nitrogen pressure, the polymer was discharged in the form of strands, cooled and pelletized to obtain polyester pellets, and then the polyester pellets were subjected to vacuum for 220 ℃. Solid-phase polymerization was performed at °C to obtain polyester resin I.

The intrinsic viscosity of the polyester resin I was 0.70 dl/g.

(polyester resin II)

100 parts by mass of dimethyl terephthalate, 60 parts by mass of ethylene glycol, and 0.09 parts by mass of magnesium acetate tetrahydrate were taken into a reactor, heated and elevated, and methanol was distilled off to perform a transesterification reaction. Here, the temperature was raised to 230° C. over 4 hours from the start of the reaction, and the transesterification reaction was substantially completed.

Next, spherical alumina particles are added and added as a ethylene glycol slurry. After adding the slurry, 0.03 parts by mass of phosphoric acid was further added, and antimony trioxide was added so that the content in terms of antimony atoms was 330 ppm by mass concentration, and a polycondensation reaction was performed to obtain polyester resin II. The intrinsic viscosity of the polyester resin II was 0.61 dl/g.

At this time, particles having a particle diameter of 0.300 μm or more were not included in the spherical alumina particles, and the content of the spherical alumina particles was 1.5% by mass relative to the entire polyester resin II.

(polyester resin III)

In the preparation of the polyester resin II, the polyester resin III was obtained in the same manner as the above-mentioned polyester resin II, except that instead of adding the spherical alumina particles, the amorphous fine silica particles were added. The intrinsic viscosity of the polyester resin III was 0.61 dl/g.

At this time, particles having a particle diameter of 0.300 μm or more were not included in the amorphous fine silica particles, and the content of the amorphous fine silica particles was 0.3% by mass relative to the entire polyester resin III.

(polyester resin IV)

In the preparation of the polyester resin II, the polyester resin IV was obtained in the same manner as the above-mentioned polyester resin II, except that instead of adding the spherical alumina particles, the addition of the ion exchange resin particles was changed. The intrinsic viscosity of polyester resin IV was 0.61 dl/g.

In this case, the ion exchange resin particles contain particles having a particle diameter of 0.300 μm or more, and the content of the ion exchange resin particles is 0.5% by mass relative to the entire polyester resin IV.

(polyester resin V)

In the preparation of polyester resin II, polyester was obtained in the same manner as the above polyester resin II, except that the spherical alumina particles were not added, and the antimony trioxide was changed so that the content in terms of antimony atoms was 240 ppm by mass. Resin V. The intrinsic viscosity of the polyester resin V was 0.63 dl/g.

<Particle-containing surface layer forming composition>

The following raw materials were used, and in the following Examples and Comparative Examples, these raw materials were blended in the mass ratios shown in the table to prepare a coating liquid as a particle-containing surface layer forming composition.

·Antistatic agent (A1)

Polydiallyldimethylammonium chloride (number average molecular weight: about 30000)

·Wax (B1)

300 g of oxidized polyethylene wax having a melting point (softening point) of 105°C, an acid value of 16 mgKOH/g, a density of 0.93 g/mL, a number average molecular weight of 5,000, and a 650 g of ion-exchanged water, 50 g of decaglycerol monooleate surfactant, and 10 g of 48% potassium hydroxide aqueous solution were replaced with nitrogen, sealed, stirred at Pass through a homogenizer at 400 air pressure and cool to a wax emulsion of 40°C.

Particles (C1): silica particles with an average particle diameter of 0.05 μm

Particles (C2): silica particles with an average particle diameter of 0.08 μm

In addition, the average particle diameter of particle (C1) - particle (C2) was calculated|required using the transmission electron microscope (Hitachi High-Tech Corporation H7650, acceleration voltage 100kV).

·Aqueous dispersion (D1)

Aqueous acrylic resin dispersion having a glass transition temperature of 40°C polymerized according to the following composition

Emulsified polymer of ethyl acrylate/n-butyl acrylate/methyl methacrylate/N-methylol acrylamide/acrylic acid=65/21/10/2/2 (mass %) (emulsifier: anionic surface active agent)

·Crosslinking agent (E1): Hexamethoxymethylol melamine

<Example 1>

As the A layer containing particles, polyester resin I and polyester resin II were blended in a mass ratio of 85:15, melted with an extruder, and supplied to the A layer of the lamination die. Out of the machine, the polyester resin I was melted and supplied to the layer B of the lamination die. The two types of three-layer laminated polyester resins having the structure of A layer/B layer/A layer were coextruded in a film form, and cast on a cooling roll at 35°C to prepare a quenched and solidified unstretched film.

Next, after preheating the unstretched film with a heating roll at 75°C, an infrared heater and a heating roll were used in combination to stretch 3.2 times in the longitudinal direction between the rolls at 85°C. One-sided in-line coating of the coating liquid prepared with the formulation shown in the following Table 1 as the particle-containing surface layer forming composition, then, the film end was held with a clip and introduced into a tenter, at a temperature of 95°C. It was heated and stretched 4.5 times in the transverse direction, and was heat-treated at 225° C. for 10 seconds to produce a 16.0 μm thick (A layer/B layer/A layer=1.0 μm/14.0 μm/1.0 μm) and a width of 1580 mm. and a polyester film (sample) with a particle-containing surface layer having a thickness of 0.030 μm on the surface of the base polyester film.

<Examples 2, 3, Comparative Examples 1, 2, 3, 4>

A polyester film (sample) was produced in the same manner as in Example 1, except that the raw material of the base polyester film was changed as shown in Tables 1 and 2.

<Comparative Example 5>

A polyester film (sample) was produced in the same manner as in Example 1, except that the particle-containing surface layer was not formed.

<Measurement method and evaluation method>

The measurement method and evaluation method of each physical property value of the material used in the said Example and the comparative example, a base polyester, and a polyester film (sample) are as follows.

(1) Thickness of polyester film (μm)

The thickness of the polyester film (sample) was measured using a micrometer.

(2) The thickness of each layer (layer A and layer B) of the base polyester film, and the thickness of the particle-containing surface layer

The thickness of each layer (layer A and layer B) of the base polyester film and the thickness of the particle-containing surface layer were measured by observation of the cross section of the film with a transmission electron microscope (TEM).

Specifically, first, a small piece of a thin film sample was embedded in a resin in which a curing agent and an accelerator were mixed with an epoxy resin, and a slice having a thickness of 200 nm was prepared with an ultramicrotome as a sample for observation.

The obtained sample was observed with a transmission electron microscope (H-9000) manufactured by Hitachi High-Tech Corporation. In the observed cross section, the interface between the A layer and the B layer and the interface between the surface of the base polyester film and the particle-containing surface layer were observed through light and shade almost parallel to the base polyester film.

For 50 transmission electron microscope photographs, the distance from the interface to the film surface was measured, 10 points from the larger measurement value and 10 points from the smaller measurement value were deleted, and the 30 points were averaged as the measurement value. The thickness of each layer and the thickness of the particle-containing surface layer were obtained from the average value.

However, in the transmission electron microscope, the acceleration voltage is set to 300 kV, and the magnification is set in the range of 1 to 100,000 times according to the thickness of the surface layer.

(3) Average surface roughness (Ra) of the film surface

The average surface roughness (Ra) of the film surface on the opposite side to the particle-containing surface layer was determined as follows using a surface roughness measuring device (SE-3F) manufactured by Kosaka Laboratory Co., Ltd.

That is, from the film cross-sectional curve obtained by the measurement, a portion of the reference length L (2.5 mm) is extracted in the direction of the center line, and the center line of the extracted portion is taken as the x-axis, the direction of the vertical magnification is taken as the y-axis, and the When the roughness curve y=f(x) is represented, the value given by the following formula is represented by [µm].

For the average roughness of the center line, 10 cross-sectional curves were obtained from the surface of the sample film, and the average value of the average roughness of the center line of the extracted portion obtained from these cross-sectional curves was expressed. In addition, the tip radius of the stylus was set to 2 μm, the load was set to 30 mg, and the cutoff value was set to 0.08 mm.

(4) Maximum height of film surface (Rt)

The maximum height (Rt) of the film surface on the opposite side to the particle-containing surface layer was measured as follows.

For the extracted part of the cross-sectional curve obtained during Ra measurement, when the extracted part is sandwiched by two straight lines parallel to the mean line, the interval between the two straight lines is measured in the direction of the vertical magnification of the cross-sectional curve, and the distance between the two straight lines is measured with a micrometer ( This value expressed in units of μm) was taken as the maximum height (Rt) of the extracted part.

For the maximum height, 10 cross-sectional curves were obtained from the surface of the sample film, and the average value of the maximum heights of the extracted portions obtained from these cross-sectional curves was expressed.

(5) Average particle size (μm)

The average particle diameter of the particles in each layer is measured by observing 10 or more particles with a scanning electron microscope (SEM), measuring the diameter of the particles, and obtaining the average value. At this time, in the case of non-spherical particles, the average value of the longest diameter and the shortest diameter was measured as the diameter of each particle.

(6) Particle concentration of the base polyester film

In the polyester film (sample), a sample is cut from the layer where the particle concentration is to be measured, and a solvent in which polyester is dissolved but the particles are not dissolved is selected for dissolution treatment, and the particles are centrifuged from the solution to measure the total mass relative to the particles. The mass ratio (ppm) as the particle concentration.

(7) Intrinsic viscosity

About 0.25 g of the freeze-pulverized base polyester film was dissolved in about 25 mL of a mixed solvent of phenol/1,1,2,2-tetrachloroethane (mass ratio 1/1) at 120° C. for 30 minutes, so that After the concentration was 1.00 g/dL, it was cooled to 30°C, and at 30°C, using an automatic solution viscometer (manufactured by SENTECH, "DT553"), the drop seconds of the sample solution and the solvent alone were measured, and the following formula (1 ) to calculate the intrinsic viscosity.

Intrinsic viscosity=((1+4K _H η _sp ) ^0.5 -1)/(2K _H C)... Formula (1)

Here, η _sp =η/η ₀ -1, η is the number of seconds of falling of the sample solution, η ₀ is the number of seconds of falling of the solvent only, C is the concentration of the sample solution (g/dL), and K _H is the Huggins constant. K _H was adopted as 0.33.

(8) Haze of the film

According to JIS K 7105:1981, the haze of the polyester film (sample) was measured with an integrating sphere turbidimeter NDH-20D manufactured by Nippon Denshoku Kogyo Co., Ltd.

(9) Coefficient of static friction and coefficient of dynamic friction

According to ASTM-D1894 (1999), two polyester films (samples) were prepared, and the static friction coefficient and the dynamic friction coefficient of the upper surface and the lower surface of the polyester film (sample) were measured.

(10) Antistatic properties

The polyester film (sample) was sufficiently conditioned in a measurement atmosphere of 23° C. and 50% RH, and the polyester film (sample) after being applied with an applied voltage of 100 V for 1 minute was used a high-resistance product manufactured by Hewlett-Packard Company in Japan. Measuring device: HP4339B and measuring electrode: HP16008B, measure the surface resistivity value of the particle-containing surface layer of the substrate film. Based on this surface resistivity value, the antistatic property was evaluated according to the following criteria.

○ (good): the surface resistivity value is 1×10 ¹² Ω/□ or less

△ (general): The surface resistivity value is greater than 1×10 ¹² Ω/□ and less than 2×10 ¹³ Ω/□

× (poor): the surface resistivity value is greater than 2×10 ¹³ Ω/□

(11) Scratch on the surface of the substrate film

Separately, a base film without a particle-containing surface layer was produced, and the surface of the base film was visually inspected and evaluated according to the following criteria.

○ (good): No flaws were observed in the inspection range.

× (poor): Many scratches were observed within the inspection range.

(12) Grinding property of particle-containing surface layer

An aluminum plate with a width of 10 mm and a length of 50 mm was brought into contact with the particle-containing surface layer surface of the polyester film (sample). Both ends of the surface of the particle-containing surface layer on which the aluminum plate was advanced were observed with a microscope, and were determined according to the following criteria.

○ (good): Grinding of the particle-containing surface layer was hardly observed.

× (poor): The particle-containing surface layer was ground, and a lot of white powder was observed.

(13) Coilability

Using a polyester film (sample), it was made into a roll shape of 1000 mm wide x 6000 m long, and the roll was wound up at a speed of 100 m/min using a winder. The appearance of the roll after being rolled up was visually inspected and evaluated according to the following criteria.

○ (good): The polyester film (sample) has no wrinkles, and the roll end faces are beautifully aligned.

Δ (fair): The roll ends are aligned, but the polyester film (sample) has small wrinkles.

× (poor): The polyester film (sample) meanders or a large wrinkle is introduced into the polyester film (sample) in the middle of the winding of the roll.

(14) Productivity

When continuously producing a polyester film (sample) stretched by 4.5 times or more in the transverse direction, the number of occurrences of breakage (film breakage) was determined according to the following criteria.

○ (good): On average less than once a day

△ (General): On average more than once a day and less than 3

× (poor): 3 times or more per day on average

(15) Evaluation of uneven thickness

A polyester film (sample) was cut out from a 1000 mm wide roll, 5 films were stacked, and the thickness was measured using a micrometer at 20 equal 1000 mm wide positions. The thickness of each position was divided by the number of overlapping sheets, and the difference between the thicknesses of adjacent positions was determined as thickness unevenness according to the following criteria.

○ (good): The difference in thickness is less than 0.50 μm

△ (general): The difference in thickness is 0.50 μm or more and less than 1.00 μm

× (poor): The difference in thickness is 1.00 μm or more

[Table 1]

[Table 2]

From the results of the above-mentioned Examples and Comparative Examples, as well as the test results conducted by the present inventors so far, it can be seen that by setting the intrinsic viscosity of the base polyester film to 0.65 dl/g or more, even if the stretching ratio, especially the width When the stretching ratio in the direction is set to 4.5 times or more, it can be stretched without breakage, the thickness unevenness in the width direction of the film can be reduced, the thickness of the film can be made uniform, and air accumulation can be prevented when it is wound into a roll. to reduce wrinkles.

In addition, it can be seen that by setting the average particle diameter of the particles contained in the A layer forming the surface layer of the base polyester film to 0.030 to 0.200 μm and the mass concentration of the particles to 10 to 7000 ppm, the particles containing the average particle diameter are formed at the same time. The particle-containing surface layer with particles of 0.005 to 0.150 μm can further improve the flatness and transparency of the film, but still can improve the sliding property of the film, so that not only can it be wound into a roll shape, but scratches can be reduced .

Claims (5)

1. A polyester film for dry film resist, characterized in that it is a dry film resist having a particle-containing surface layer on at least one side of a base polyester film having an intrinsic viscosity of 0.65 dl/g or more agent polyester film, The base polyester film contains particles with an average particle diameter of 0.030 to 0.200 μm in a mass ratio of 10 to 7000 ppm, and is a single layer formed by a polyester layer that does not substantially contain particles with a particle diameter of 0.300 μm or more, that is, the A layer. layer or a multilayer film having the A layer on the surface, The particle-containing surface layer contains particles having an average particle diameter of 0.005 to 0.150 μm. 2 . The polyester film for a dry film resist according to claim 1 , wherein the particle-containing surface layer further contains any one or both of an antistatic agent and a wax. 3 . 3. The polyester film for dry film resist according to claim 1 or 2, wherein the base polyester film is provided with the A layer only on one side, and the base polyester film is provided with the A layer on the side opposite to the A layer. particle surface layer. 4 . A method for producing a polyester film for a dry film resist, wherein the method for producing a polyester film for a dry film resist according to claim 1 , wherein: 5 . The base polyester film is stretched in the width direction at a stretching ratio of 4.0 times or more. The photosensitive laminated body which laminated|stacked the photoresist layer on at least one side of the polyester film for dry film resists in any one of Claims 1-3.