JP6075103B2 - Endless belt metal mold and manufacturing method thereof - Google Patents

Description

  The present invention relates to an endless belt-shaped metal mold for producing a fine pattern transfer film by transferring a fine concavo-convex pattern structure onto the surface of a thermoplastic film, and a method for producing the same. This endless belt-shaped metal mold manufactures micropattern transfer films that require micron to nano-sized fine patterns on the surface, such as optical films that have optical functions such as diffusion, light collection, reflection, and transmission. Used in equipment.

  As a method for producing an optical film used for an optical film such as a prism sheet, a light diffusion sheet, or a lens sheet, the film is pressed against the surface of an endless belt-shaped mold having a fine uneven pattern formed on the surface, There is a method for transferring a fine uneven pattern of a mold onto the surface of a film. Furthermore, a method or an apparatus that can be applied to a film made of a long thermoplastic material and that is continuously processed from unwinding through a transfer process to winding is proposed.

  These methods apply a mold made of an endless belt having a fine pattern formed on the surface, press a film made of a thermoplastic resin on a heated mold to form a fine concavo-convex structure on the film surface, This is a method of peeling the film after cooling the mold. The heating and cooling of the mold is performed by bringing the mold made of an endless belt into contact with the heating roll and the cooling roll, and the transfer of the fine pattern to the film is performed. The film is formed by sandwiching a die made of an endless belt and a film between a heating roll and a nip roll facing the heating roll. With this structure, the temperature at the time of transfer and the temperature at the time of peeling can be controlled independently, so even if the mold temperature at the time of transfer is set high, the peelability does not become a problem. A pattern can be transferred (for example, see Patent Document 1).

  As a manufacturing method of the endless belt-shaped mold having such a fine pattern formed on the surface, for example, the end portions of the metal flat plate prepared by electroforming are joined together to form an endless belt (for example, Patent Document 2, refer to), or an electroless plate attached to the surface of an endless belt via an adhesive layer (for example, refer to Patent Document 3, refer to Patent Document 3). And the like (for example, see Patent Document 1).

JP 2012-210760 A JP 2007-268866 A JP 2009-78521 A

  However, in the endless belt-shaped mold manufactured by the method described in Patent Document 2, since the electroformed plates such as nickel are brought together and welded, the welding strength is insufficient. The yield stress of electroformed plates varies depending on the material and formulation, but is about 300 MPa for nickel electroformed plates, which is significantly inferior to 800 to 1,200 MPa for stainless steel generally used as endless belts. In addition, a stainless steel plate is unlikely to have a significant decrease in strength even when butt welding is performed, whereas in nickel electroforming, the strength of the welded portion tends to decrease. For this reason, in particular, in the configuration in which the endless belt is suspended between the heating roll and the cooling roll, the belt is repeatedly bent and stretched, so that the belt is easily broken from the welded portion, and practical durability cannot be obtained. There was a problem.

  Moreover, in the endless belt-shaped metal mold manufactured by the method described in Patent Document 3, there is a problem that the end of the electroformed plate attached is easily peeled off because it is bent and stretched unevenly.

  On the other hand, as described in Patent Document 1, when cutting a metal roll fitted with an endless belt with a lathe, there is no such problem, but the fitting accuracy affects the machining accuracy, for example, Due to the side-by-side fitting, problems such as variations in the thickness of the belt in the circumferential direction are likely to occur. In addition, for shapes suitable for processing on a lathe machine, such as grooves that are continuous in the circumferential direction, shape processing can be performed with high accuracy only by reducing the roll deflection accuracy. It is necessary to synchronize the rotation of the roll and the axial movement of the cutting tool or roll with respect to the groove having the direction of the angle, the meandering groove, etc. Inferior.

  Also, when the groove depth is changing or the groove itself is intermittent, it is necessary to synchronize the rotation of the roll and the movement of the cutting tool in the roll diameter (cutting depth) direction. That is, the machining limit is determined by the indexing accuracy of the spindle.

  In particular, the larger the circumference of the endless belt, the larger the roll diameter to be fitted, and even if the problem of contact accuracy can be solved, it is difficult to obtain the same pattern shape accuracy as when fitted to a small diameter roll. is there. For example, as a general precision lathe machine, the indexing accuracy of the spindle is 0.001 °, the tool axis accuracy is 0.1 μm, and if the endless belt has a circumference of 100 mm, the circumferential positioning accuracy is 0.3 μm. This is because the endless belt with a circumferential length of 1,000 mm has a circumferential positioning accuracy of 2.8 μm, which is greatly inferior to the tool axis accuracy, although it is not significantly inferior to the accuracy of the tool axis. Therefore, in the case of machining that requires a high positioning accuracy of about 1/10 to 1/100 of the groove period in the circumferential direction, such as meandering grooves and discrete grooves, the lathe machine repeats fine uneven patterns. When the cycle is 1 / 3,600 or less of the circumference of the endless belt, there is a problem that high-precision machining cannot be performed.

  In addition, when trying to manufacture an endless belt mold with a larger circumference, for example, a circumference of 2,000 mm or more, the diameter of the roll to be fitted is close to 700 mm, and a high-precision lathe machine that can be practically processed is available. There was a problem that even if it was not, it was very limited.

  An object of the present invention is to eliminate the above-mentioned problem, and is an endless belt-shaped metal mold for transferring and forming a fine pattern by pressing on the surface of a thermoplastic film, which has sufficient strength and high accuracy. An object of the present invention is to provide a method for manufacturing a belt-shaped metal mold having a fine shape with high accuracy and low cost even if the mold has a high degree of freedom in shape and a large circumference.

In order to solve the above problems, the present invention adopts the following configuration.
(1) It is composed of one or more metal flat plates each having a base layer and a plating layer. The base layer is exposed at the end of the metal flat plate, and the base layers exposed at the end are welded together. An endless belt-like metal mold, wherein the plating layer has a fine pattern.
(2) The material of the base layer is stainless steel, the plating layer is a nickel plating layer, the total thickness of the endless belt-shaped metal mold is 0.05 to 0.3 mm, and the nickel plating layer The endless belt-shaped metal mold according to (1), wherein the thickness is 1/2 or less of the total thickness of the endless belt-shaped metal mold.
(3) The fine pattern is periodically formed at least in the circumferential direction of the endless belt-shaped metal mold, and the period P of the fine pattern and the peripheral length L of the endless belt-shaped metal mold. The endless belt-shaped metal mold according to (1) or (2), characterized in that P ≦ L / 3,600.
(4) The endless belt-shaped metal mold according to any one of (1) to (3), wherein a circumference L of the endless belt-shaped metal mold is 2,000 mm or more.

The present invention also provides the following production method.
(5) Applying plating to at least one base layer of one or more metal flat plates except for an end, forming a plating layer, and then cutting the plating layer to form a fine pattern, and then the fine pattern A method for producing an endless belt-shaped metal mold, comprising forming a plating layer having an outer surface as an outer surface, and joining base layers at end portions of the metal flat plate together to form an endless belt.
(6) The first fine pattern formed on the plating layer of the first metal flat plate, wherein the metal flat plate is a plurality of metal flat plates including at least a first metal flat plate and a second metal flat plate. The method for producing an endless belt-shaped metal mold according to (5), wherein the second fine pattern formed on the plating layer of the second metal flat plate is a different pattern.

The present invention also provides the following manufacturing apparatus.
(7) The endless belt-shaped metal mold according to any one of (1) to (4), or the endless belt-shaped metal mold manufactured by the manufacturing method according to (5) or (6); A pressurizing mechanism comprising at least a heating roll for heating the endless belt-shaped metal mold, a nip roll disposed in parallel with the heating roll, and a pressing means using the both rolls; and the endless belt-shaped A cooling roll for cooling the metal mold, a peeling roll for peeling the film adhered to the endless belt-shaped metal mold, and the endless belt-shaped metal by rotating the heating roll and / or the cooling roll. An apparatus for producing a fine pattern transfer film, comprising a conveyance mechanism for conveying a mold.

  According to the present invention, an endless belt-shaped metal mold for transferring and forming a fine pattern by pressing on the surface of a thermoplastic film is subjected to plating on the base layer of one or more metal flat plates except for the end portion. By cutting the plating layer to form a fine pattern, and then producing the plating layer on which the fine pattern is formed as the outer surface, the ends of the metal flat plates are welded together to produce sufficient strength and high strength. It has an accurate fine pattern, has a high degree of freedom in shape, and can be manufactured with high accuracy and low cost without depending on the size of the mold.

It is the schematic which shows the structure of the endless belt-shaped metal metal mold | die in one Embodiment of this invention. It is a section schematic diagram of one embodiment of a manufacturing device of a fine pattern transfer film to which the present invention is applied. In one Embodiment of this invention, it is the schematic which shows the metal flat plate holding | maintenance method at the time of plating a metal flat plate.

  The endless belt-shaped metal mold of the present invention is composed of one or more metal flat plates each having a base layer and a plating layer. At the end of the metal flat plate, the exposed base layers are butt-welded to each other, and the plating layer is finely coated. It has a pattern.

  FIG. 1 shows the structure of an endless belt-shaped metal mold, which is an example of an embodiment of the present invention.

  As shown in FIG. 1, one or a plurality of metal flat plates 33 having a base layer 31 and a plating layer 32 (three in FIG. 1) are used in the endless belt-shaped metal mold of the present invention. The base layer 31 is exposed at the end of the metal flat plate 33, and the base layer is butt welded at the exposed portion 34 to form an endless belt. A fine pattern 35 is formed on the plating layer 32.

[Base layer, plating layer]
That the base layer is exposed means a state in which there is no plating layer formed on the surface of the base layer.

  The material of the base layer is not particularly limited as long as it can maintain the strength to be used as an endless belt. Steel is preferably used. The required strength for using the endless belt is determined by the actual use conditions, the plate thickness, etc., but the yield stress is preferably 300 MPa or more, more preferably 500 MPa or more. The yield stress in these stainless steel welds is about 600 to 1,200 MPa, and it can sufficiently withstand use as an endless belt. However, in such stainless steel, a diamond tool such as a single crystal or polycrystal generally used for forming a fine pattern may be worn due to heat generation when the stainless steel is cut.

  Therefore, in order to increase the shape accuracy and surface roughness accuracy of the fine pattern on the surface of the endless belt-shaped metal mold, it is preferable to form a plated layer with good cutting ability with diamond on the surface of stainless steel. The functions required for the plating layer include fine pattern shape accuracy, surface roughness accuracy, and sufficient strength when using a mold. Amorphous nickel plating and copper plating that enable accurate transfer of tool shapes Is preferable, and nickel plating is particularly preferable.

  On the other hand, for example, a material without a base layer such as a nickel electroformed plate may be difficult to use as an endless belt-shaped metal mold because welding itself is difficult or the strength of the welded portion is insufficient. .

  The thickness of the nickel plating layer is preferably 1/2 or less of the total thickness of the endless belt-shaped metal mold. When the thickness of the nickel plating layer is greater than 1/2 of the total thickness of the belt-shaped metal mold, peeling occurs at the boundary surface between the base layer and the nickel plating layer due to bending at the heating roll and cooling roll. This is because there are cases. Also, since the quality of the nickel plating layer is difficult to stabilize near the boundary surface with the base layer, the thickness of the nickel plating layer is preferably 0.02 mm or more.

  The thickness of the nickel plating layer is arbitrary depending on the above and the fine pattern depth, but is preferably 0.02 to 0.1 mm.

[Endless belt metal mold]
The total thickness of the endless belt-shaped metal mold is preferably in the range of 0.05 to 0.3 mm. This is because, for example, in the apparatus for producing a fine pattern transfer film shown in FIG. 2, the endless belt-shaped metal mold is broken or plasticized by tension when it is suspended from a heating roll and a cooling roll when the thickness is less than 0.05 mm. This is because it may be deformed. On the other hand, when the thickness is larger than 0.3 mm, the bending rigidity of the endless belt-shaped metal mold becomes too large, and it may be suspended on the heating roll and the cooling roll or conveyed while being suspended on these rolls. This is because it may be difficult.

  Here, when there is a fine pattern such as a concave shape in a part of the plating layer, the total thickness means the thickness of the most convex portion of the fine pattern.

  The manufacturing method of the endless belt-shaped metal mold according to the present invention is such that at least one base layer of one or more metal flat plates is plated except for an end portion, and after forming a plating layer, the plating layer is cut to obtain a fine A pattern is formed, and thereafter, a plating layer on which a fine pattern is formed is used as an outer surface, and base layers at end portions of a metal flat plate are butt-welded to form an endless belt.

  As long as the end portions can be welded together, there is no particular limitation on the area where the base layer is exposed.

  Here, butt welding refers to welding materials having the same thickness in the same plane.

  Also, “welding the base layers together” means joining the exposed end portions of the base layers together. From the viewpoint of dimensional accuracy and strength, butt welding by laser welding or microplasma welding in which the base layer ends are brought into close contact with each other and the base layer is melted and integrated by irradiating the contact portion with laser or microplasma is preferable.

[Formation of plating layer]
The plating layer may be formed by any method as long as the flatness of the metal flat plate being plated can be maintained. For example, as shown in FIG. 3, the base layer 31 is bolted to the rigid flat plate 15 or a magnetic stainless steel flat plate. It is preferable to perform plating in a state of being supported by a support member, such as using a magnet to chuck the magnet block.

  However, since there is thermal expansion in the plating bath, it is preferable to match the linear expansion coefficients of the support member and the metal flat plate. For this reason, it is preferable that the material of the support member is the same as that of the metal flat plate. At this time, it is preferable that the welding end of the metal flat plate is masked with a masking tape 16 or the like in preparation for welding in a later step so that plating is not applied. This is intended to prevent this because even if the base layer and the plating layer are both butt-welded at the same time, welding cannot be performed, or even if welding can be performed, the welding strength cannot be maintained. By masking the weld end during plating, the base layer at the end of the metal flat plate is exposed, so that a single base layer with high welding strength can be welded together at the end of the metal flat plate, which is sufficient as an endless belt A good welding strength can be obtained.

  The bolt fixing part and part of the mask part can be removed by cutting the base layer after plating according to the necessity in the subsequent process. However, it is preferable to leave a part of the mask portion with a width of about 1 to 10 mm for butt welding in a later process.

[Fine pattern]
Next, plating is performed, and a fine pattern is formed by cutting the plating layer on the metal flat plate on which the plating layer is formed. Here, since the metal flat plate on which the plating layer is formed is sufficiently flat, it can be subjected to high-precision cutting with a flat plate processing machine.

  Here, the fine pattern is a concave shape having a depth of 10 nm to 100 μm, preferably a depth of 1 μm to 50 μm, and a period of at least 10 nm to 1 mm, preferably a pitch of 1 μm to 100 μm, in the width direction of the endless belt-shaped metal mold. It shows the shape that was repeated automatically. As the dent shape, the belt circumferential direction is the longitudinal direction, and the shape of the cross section perpendicular to the longitudinal direction is triangular, rectangular, semicircular, and semi-elliptical grooves are arranged in multiple stripes Etc. Further, the dents occupy 1/2 or more of the entire area, and a convex shape having a height of 10 nm to 100 μm, preferably a height of 1 μm to 50 μm, at least in the width direction of the endless belt metal mold, a pitch of 10 nm to 1 mm, preferably The shape may be periodically repeated with a pitch of 1 μm to 100 μm.

  The longitudinal direction of the groove does not need to coincide with the circumferential direction of the belt, and may be a groove having a longitudinal direction as a direction having a specific angle in the circumferential direction of the belt. Moreover, the meandering groove | channel from which the position of the width direction of a groove | channel fluctuates may be sufficient in the circumferential direction of a belt.

  The depth of the groove does not need to be constant along the longitudinal direction of the groove, and may be a rocking groove whose groove depth changes or an intermittent groove where the groove is intermittent.

  Two or more grooves may intersect, for example, a groove inclined 45 ° clockwise with respect to the circumferential direction of the belt and a groove inclined 45 ° counterclockwise with respect to the circumferential direction of the belt. .

  In a lathe machine, the grooves may be concentrically arranged grooves that are very difficult to machine, or may be grooved with folds.

  Unlike a lathe machine, a flat plate machine is unlikely to cause problems depending on the machining direction such as runout accuracy, and high-precision machining is easy. In particular, grooves in a direction having a specific angle with respect to the circumferential direction of the belt, serpentine grooves, and the like can be processed with high accuracy. This is because there is no axis that greatly reduces accuracy depending on the workpiece size, especially in shapes that require high positioning accuracy in the circumferential direction of belt-shaped metal molds such as serpentine grooves and discrete grooves, The fine pattern is periodically formed in the circumferential direction of the endless belt-shaped metal mold, and the fine pattern period P is 1 / 3,600 or less of the circumference L of the belt-shaped metal mold. Even if it exists, highly accurate processing is possible.

  Here, when the fine pattern is periodically formed in the circumferential direction of the endless belt-shaped metal mold, the depth of the fine pattern changes in the circumferential direction of the belt, or the fine pattern is intermittent in the circumferential direction. It is formed, or the fine pattern changes such that the fine pattern is continuous in the circumferential direction while meandering in the width direction of the belt, and the change is repeated at least in the circumferential direction of the belt, The period P is a repeated length in the circumferential direction of the belt.

  The peripheral length L of the endless belt-shaped metal mold refers to the shortest length in the circumferential direction of the belt along the inner peripheral surface of the belt.

  In addition, in the present method, when an endless belt-shaped metal mold is manufactured using a plurality of metal flat plates, each metal flat plate is made smaller, and the number of metal flat plates to be used is increased correspondingly, thereby making the endless belt-shaped metal mold. Can be manufactured. In this case, it becomes possible to perform cutting with high precision by a small precision processing machine. In particular, there is no high-precision lathe machine that can be practically processed, and even an endless belt-shaped metal mold with a circumference L of 2,000 mm or more, which could only be processed with low accuracy by the turning method, was divided. By processing using a flat plate processing machine, it is possible to perform processing without deteriorating the processing accuracy of the fine shape. The upper limit of the circumference L is not particularly limited, but 10,000 mm is the upper limit in consideration of productivity.

  When cutting with a flat plate processing machine, the metal plate may be fixed to the support member used at the time of plating, or it may be removed from the support member at the time of plating, and only the metal plate is vacuum adsorbed. Alternatively, processing may be performed by fixing by a known method such as magnet adsorption. It is also possible to perform processing while being fixed to a cutting support member.

[Method of manufacturing endless belt-shaped metal mold]
Thus, the metal flat plate in which the fine pattern is formed on the plating layer is butt-welded with the base layers at the end portions where the plating is not applied to form an endless belt-shaped metal mold. The metal flat plate used for the formation of the endless belt-shaped metal mold may be an endless belt-shaped metal mold by using only one plate and attaching the base layers at both ends thereof. The base layers at the ends of the metal flat plate may be joined together and welded to form an endless belt-shaped metal mold. Further, in order to produce a wide endless belt-shaped metal mold, it is also possible to butt and weld metal flat plates in the width direction of the endless belt-shaped metal mold.

  The endless belt-shaped metal mold can be made by welding together multiple metal flat plates of 1,000 mm x 1,000 mm or less that can be machined with high precision on a flat plate processing machine. It is also preferable from the aspect of flat plate handling.

  Thus, when manufacturing an endless belt-shaped metal mold using a plurality of metal flat plates, the shape of the fine pattern applied to each metal flat plate may be the same, but different patterns may be used. is there.

  Different patterns are different in the shape of the pattern cross section viewed from the cross section perpendicular to the longitudinal direction of the pattern, or the groove repetition period or number in the belt width direction is different, or the groove depth averaged in the belt length direction Is at least one of 1.2 times different.

  In the endless belt-like metal mold according to the present invention, the cross-sectional shape can be different, for example, a V-shaped groove and a semicircular lenticular groove, or the same shape. However, it is possible to make the groove repetition period different in the belt width direction, or make the groove depth different. If such an endless belt metal mold is used, it will be described later. When manufacturing a fine pattern transfer film, products having a plurality of different fine patterns can be produced in parallel.

[Production equipment for fine pattern transfer film]
The endless belt-shaped metal mold manufactured in this way can be suitably used in the manufacturing apparatus 1 for a fine pattern transfer film shown in FIG. The fine pattern transfer film manufacturing apparatus 1 includes an endless belt-shaped metal mold 3, a heating roll 4 on which the endless belt-shaped metal mold is suspended, and a cooling roll 5 for cooling the endless belt-shaped metal mold. Have. Also, a nip roll 6 that is arranged in parallel with the heating roll 4 for heating the endless belt-shaped metal mold and press-molds the forming film 2, and the film after molding is peeled from the endless belt-shaped metal mold 3. A peeling roll 7 is provided. The heating roll 4 and the nip roll 6 arranged in parallel with the heating roll 4 have at least one of the narrow pressure means 14 in order to press the endless belt-shaped metal mold 3 and the forming film 2 with both rolls. And is configured as a pressurizing mechanism. In addition, as a transport mechanism for transporting the endless belt-shaped metal mold 3 suspended on the heating roll 4 and the cooling roll 5 so as to circulate, a driving unit that rotationally drives the heating roll 4 and / or the cooling roll 5 is provided. Yes. In addition, an unwinding roll 9 and a winding roll 10 are provided for unwinding and winding the forming film, and one or a plurality of guide rolls 8 are provided so as to fit the conveying path of the forming film 2. ing.

  A series of molding operations by the fine pattern transfer film manufacturing apparatus 1 is as follows. The forming film 2 unwound from the unwinding roll 9 is supplied onto the endless belt-shaped metal mold 3 heated by the heating roll 4. The forming film 2 laminated with the endless belt-shaped metal mold 3 is pressed against the fine pattern surface 3a of the endless belt-shaped metal mold 3 by the nip roll 6, and the endless belt-shaped metal mold 3 is pressed against the molding surface 2a of the forming film. A shape corresponding to the shape of the surface, that is, a fine pattern opposite to the fine pattern of the endless belt-shaped metal mold 3 is transferred and molded. Thereafter, the forming film 2 is conveyed to the outer surface of the cooling roll 5 in a state where the endless belt-shaped metal mold 3 is in close contact with the forming surface 2a of the forming film. The forming film 2 is cooled by heat conduction through the endless belt-shaped metal mold 3 by the cooling roll 5, peeled off from the endless belt-shaped metal mold 3 by the peeling roll 7, and taken up on the winding roll 10. It is done. The above operation is continuously performed.

  The nip roll 6 has a structure in which the outer surface of the core layer is covered with an elastic layer 11. The core layer is required to have strength and processing accuracy. For example, steel, fiber reinforced resin, ceramics, aluminum alloy or the like is applied. The elastic layer 11 is a layer that is deformed by a pressing force, and a resin layer represented by rubber or an elastomer material is preferably applied. The core layer is rotatably supported by bearings 13 at both ends thereof, and the bearing 13 is connected to a narrow pressure means 14 such as a cylinder. The nip roll 6 is opened and closed by the stroke of the narrow pressure means 14 to pinch or release the molding film 2.

  Further, the nip roll 6 may have a temperature adjustment mechanism in accordance with a desired process and film material. The temperature control mechanism can be heated from the inside of the roll by hollowing out the inside of the roll and embedding a cartridge heater or induction heating device, or by processing a flow path in the inside and flowing a heat medium such as oil, water, or steam. It may be a structure. Further, an infrared heater may be installed near the outer surface of the roll and heated from the outer surface of the roll.

  The heat resistance of the elastic layer 11 of the nip roll 6 is preferably one having a heat resistance temperature of 160 ° C. or higher, more preferably one having a heat resistance temperature of 180 ° C. or higher. Here, the heat resistant temperature means a temperature at which the rate of change in tensile strength when left at that temperature for 24 hours exceeds 10%. The upper limit of the heat resistant temperature is preferably 400 ° C. or less from the viewpoint of durability of the nip roll.

  As the material of the elastic layer 11, for example, when rubber is used, silicone rubber, EDPM (ethylene propylene diene rubber), neoprene, CSM (chlorosulfonated polyethylene rubber), urethane rubber, NBR (nitrile rubber), ebonite, etc. are used. Can be used. For higher elastic modulus and hardness, calender roller resins that are sold by rubber manufacturers using special prescriptions for the above rubbers or hard pressure resistant resins with improved toughness (eg polyester resins) ) Can be used.

  Next, the heating roll 4 facing the nip roll 6 and the endless belt-shaped metal mold 3 will be described. Since the heating roll 4 receives a load at the time of nip, strength and processing accuracy are required, and it is preferable to further include a heating means. Examples of the material include steel, fiber reinforced resin, ceramics, and aluminum alloy. Also, as a heating means, the inside of the roll is heated by hollowing the inside and installing a cartridge heater or an induction heating device, or by processing a flow path inside and flowing a heat medium such as oil, water, or steam. It may be a structure. Further, an infrared heater or induction heating device may be installed near the outer surface of the roll and heated from the outer surface of the roll.

  The surface of the heating roll 4 is preferably subjected to a treatment for forming a hard coating such as hard chrome plating, ceramic spraying, diamond-like carbon coating, or the like. This is because the heating roll 4 is always in contact with the endless belt-shaped metal mold 3 and is subjected to a pressing force by the nip roll 6, so that the surface thereof is very easily worn, and the surface of the heating roll 4 is worn or damaged. This is because problems such as uneven transfer of the film and transfer of the roll surface shape to the film may occur.

  The forming film 2 and the endless belt-shaped metal mold 3 are sandwiched between the heating roll 4 and the nip roll 6 and pressed.

  The cooling roll 5 is preferably cooled, for example, by a water-cooled cooling means that is provided with a water passage inside and continuously circulates water having a constant temperature. Then, the endless belt-shaped metal mold 3 is cooled by heat conduction at the contact surface with the endless belt-shaped metal mold 3.

  The end of each roll is rotatably supported by a rolling bearing or the like. The heating roll 4 is connected to driving means such as a motor, and is rotatable while controlling the speed. The cooling roll 5 is preferably rotated by the driving force of the heating roll 4 through the endless belt-shaped metal mold 3. The conveyance speed is determined in consideration of the balance between the moldability of the fine pattern and the productivity of the molded film. In order to increase the productivity while transferring the fine pattern with high accuracy, the speed is 1 to 30 m / min. It is preferable to be determined from the range. The driving means of the nip roll 6 is connected to the end of the heating roll 4 with a chain or a belt, and can be rotated in conjunction with the heating roll 4 or a motor capable of synchronizing the speed with the heating roll 4 is used. It is preferable to rotate them independently. However, the structure may be rotatable and may be rotated by friction with the forming film 2.

  Both the unwinding roll 9 and the winding roll 10 have a structure capable of fixing a core around which the forming film 2 is wound, and the end portion is connected to a driving means such as a motor and can be rotated while controlling the speed. Yes. Moreover, it is preferable that the tension applied to the molding film 2 can be adjusted by torque control.

  Like the cooling roll 5, the peeling roll 7 has a cooling means, and cools the forming film 2 from the back side, and plays a role of assisting the peeling from the endless belt-shaped metal mold 3. The pressing force of the peeling roll 7 against the molding film 2 is not particularly limited as long as the peripheral surface of the peeling roll 7 is in close contact with the back surface of the molding film 2.

[Production method of fine pattern transfer film]
The manufacturing method of the fine pattern transfer film in which the fine pattern was formed on the surface using said apparatus is demonstrated.

  The method for producing a fine pattern transfer film of the present invention comprises one or more metal flat plates having a base layer and a plating layer, and the exposed base layers are butt-welded to each other at the end of the metal flat plate, so that the plating layer is fine. A mold heating step of using an endless belt-shaped metal mold having a pattern, and heating the endless belt-shaped metal mold while holding the endless belt-shaped metal mold in a heated heating roll; a transfer side surface of the film; and the endless belt-shaped metal mold In a state in which the fine plating surface of the mold is in close contact, a pressure transfer process in which nip pressurization is performed by a pair of rolls including the heating roll, and the endless belt-shaped metal mold after pressurization and the film are in close contact with each other A transporting process for transporting to the cooling zone, and an endless belt-shaped metal with the endless belt-shaped metal mold and the film in close contact in the cooling zone; The fineness formed on the surface of the endless belt-shaped metal mold by including at least a mold cooling process for cooling from the mold side and a peeling process for peeling the film from the endless belt-shaped metal mold after cooling. A fine pattern transfer film is produced by transferring a pattern onto the surface of a heated film.

  An example of an embodiment of the present invention will be described with reference to FIG.

  First, as a preparatory stage, the forming film 2 is pulled out from the unwinding roll 9 and the nip roll 6 is opened, and then along the endless belt-shaped metal mold 3 suspended on the heating roll 4 and the cooling roll 5, the peeling roll 7 is taken up by the take-up roll 10.

  Subsequently, while the molding film 2 is conveyed at a low speed by the driving means, the heating means of the heating roll 4 and the cooling means of the cooling roll 5 are operated, and the surface temperature of the heating roll 4 and the cooling roll 5 becomes a predetermined temperature. Adjust the temperature until. The reason for adjusting the temperature while being transported is that, if not transported, the portion of the molding film 2 located on the heating roll 4 stores heat, and the film may melt and be broken there. The conditions of the surface temperature of the heating roll 4 and the surface temperature of the cooling roll 5 depend on the material of the forming film 2, the shape of the fine pattern of the endless belt-shaped metal mold 3, the aspect ratio, etc., and the surface temperature of the heating roll 4 Is set to 180 to 250 ° C., and the surface temperature of the cooling roll 5 is preferably set to 20 to 80 ° C. Moreover, it is preferable that the conveyance speed during temperature control shall be 0.1-5 m / min, and it is more preferable to set it as 0.1-1 m / min.

  When the surface temperature of the heating roll 4 and the cooling roll 5 is adjusted to the set value, the film is conveyed at the molding speed, and at the same time, the nip roll 6 is closed and the heating roll 4 and the nip roll 6 are used to form the molding film 2 and the endless belt-shaped metal gold. The mold 3 is pressurized, and the shape of the fine pattern surface 3 a of the endless belt-shaped metal mold 3 is transferred to the molding surface 2 a of the molding film 2. As conditions at this time, the film forming speed is preferably 1 to 30 m / min, and the nip pressure is preferably in the range of 80 to 120 MPa.

  The continuous transfer of the film is composed of a mold heating process, a pressure transfer process, a conveying process, a mold cooling process, and a peeling process, when the processes are arranged in accordance with the rotating operation of the endless belt-shaped metal mold 3. The endless belt-shaped metal mold 3 is always heated by heat conduction from the high-temperature heating roll 4 at a portion in contact with the heating roll 4 and is clamped by the heating roll 4 and the nip roll 6 until the endless belt-shaped metal mold 3 is pressed. The temperature of the mold 3 is raised to the surface temperature of the heating roll 4 (mold heating process). The forming film 2 is pressed against the endless belt-shaped metal mold 3 heated in the pressure-carrying portion between the heating roll 4 and the nip roll 6, and the resin constituting the softened film is a fine pattern of the endless belt-shaped metal mold 3. It is filled in the pattern of the surface 3a (pressure transfer process). The film that is narrowly pressed by the endless belt-shaped metal mold 3 is conveyed to the cooling zone while being in close contact with the endless belt-shaped metal mold 3 (conveying step).

  Here, when the endless belt-shaped metal mold of the present invention is used to transfer and form a fine pattern on a forming film, the welded portion on the endless belt is recessed with respect to the surroundings by the thickness of the plating film. Therefore, the softened resin is also filled in the dent portion, and a convex shape is formed on the film. Since the thickness of the plating layer is larger than the height of the fine pattern, this portion becomes a large protrusion on the film, and promotes film adhesion to the endless belt-shaped metal mold from the heating roll to the cooling roll. This is especially true when the height of the fine pattern itself is low or the aspect ratio is small, and the film peels off from the endless belt-shaped metal mold between the heating roll and the cooling roll only by the close contact with the fine pattern itself. In the case where molding defects are likely to occur, it serves to reinforce the adhesion, so that a fine pattern transfer with higher accuracy is possible.

  The cooling zone indicates a range where the endless belt-shaped metal mold 3 and the cooling roll 5 are in contact with each other. In the cooling zone, the film is cooled to the glass transition temperature or less of the resin constituting the film together with the endless belt-shaped metal mold 3 by heat conduction with the cooling roll 5 (cooling step). The cooled film is released from the endless belt-shaped metal mold 3 by the peeling roll 7 so as to be continuously peeled off (peeling step). The film after peeling is wound up on a winding roll 10.

  As the molding film 2 applied to the present invention, a thermoplastic film containing a thermoplastic resin as a main component is used. Specifically, polyethylene terephthalate, polyethylene-2,6-naphthalate, polypropylene terephthalate, polybutylene terephthalate are preferable. Polyester resins such as polyethylene, polystyrene, polypropylene, polyisobutylene, polybutene, polymethylpentene, etc., polyolefin resins, polyamide resins, polyimide resins, polyether resins, polyesteramide resins, polyetherester resins, acrylic Resin, polyurethane resin, polycarbonate resin, or polyvinyl chloride resin. Among these, there are various types of monomers to be copolymerized, and it is particularly easy to adjust the material properties, so that polyester resins, polyolefin resins, polyamide resins, acrylic resins, or mixtures thereof are used. It is preferably formed mainly from a selected thermoplastic resin, and more preferably contains 50% by mass or more of the above-mentioned thermoplastic resin. The upper limit of the content of the thermoplastic resin is not particularly limited, but is preferably 70% by mass or less.

  The molding film 2 may be a film made of the above-mentioned resin alone or a laminate made of a plurality of resin layers. In this case, compared with a single film, surface characteristics such as slipperiness and friction resistance, mechanical strength, and heat resistance can be imparted. Thus, when it is a laminate composed of a plurality of resin layers, it is preferable that the entire film satisfies the requirement that the above-mentioned thermoplastic resin is the main component, but the entire film does not satisfy the requirement, If a layer satisfying at least the above requirements is formed on the surface layer, the surface can be easily formed. In particular, when it is desired to increase the mold temperature in order to improve the moldability of the film, the surface layer is a resin having a low glass transition point and easy to transfer a fine pattern, and the core layer is a resin having a high glass transition point and high strength. By using a film having a configuration, it is possible to improve the moldability of the film while maintaining the flatness of the film.

  Hereinafter, the present invention will be described using examples, but the present invention is not limited to the examples.

Example 1
Using two stainless steel (SUS631) plates of 500mm x 300mm and thickness 0.15mm, mask each 5mm edge along the 300mm side, and plating on the inner part (490 x 300mm) gave. The plating was electroless nickel plating, and the thickness of the plating layer was 0.05 mm. A nickel-plated stainless steel plate was placed on a magnetic chuck on a flat plate machine and fixed, and the nickel-plated layer was grooved with a diamond tool. The groove shape was V-shaped (depth: 12.5 μm) with an apex angle of 90 ° and a pitch of 25 μm.

  The two stainless steel plates were attached to each other at the base layer at the end where the stainless steel was exposed, and welded to form an endless belt-shaped metal mold having a width of 300 mm and a circumferential length of 1,000 mm.

  The accuracy of the fine pattern of the obtained endless belt-shaped metal mold is good with a pitch of 24.7 to 25.2 μm and a depth of 12.3 to 12.6 μm, including errors during measurement. There was no problem in use.

(Examples 2-1 to 2-9)
According to the same processing procedure as in Example 1, an endless belt-shaped metal mold was manufactured with the base layer thickness and plating layer thickness shown in Table 1.

  As shown in Table 1, the roll diameters that can be used differ depending on the total thickness, but any of them could be used as an endless belt-shaped metal mold.

(Example 3)
In accordance with the same processing procedure as in Example 1, the number of stainless steel plates to be used was increased to produce an endless belt-shaped metal mold.

  Except that the number of stainless steel plates was changed to four, plating, grooving and butt welding were performed in the same manner as in Example 1 to obtain an endless belt-shaped metal mold having a width of 300 mm and a circumferential length of 2,000 mm. The accuracy of the fine pattern shape of the obtained belt-shaped metal mold is good with a pitch of 24.6 to 25.1 μm and a depth of 12.2 to 12.6 μm, including measurement errors, and can be used as an endless belt-shaped metal mold. There was no problem.

Example 4
According to the same processing procedure as in Example 1, groove processing was intermittently performed in the longitudinal direction (500 mm direction) of the plated stainless steel plate. The period of the intermittent groove processing was 0.2 mm, and during this time, a groove having a depth of 6 μm was processed so as to have a groove bottom length of 65.7 μm and a groove top length of 143.3 μm. The number of repetitions in the longitudinal direction was 2,449 times, and processing in 4,666 rows was repeated at intervals of 60 μm in the short direction so that the groove positions were arranged in a staggered manner.

  Two stainless steel plates subjected to this processing were welded to produce an endless belt-shaped metal mold having a width of 300 mm and a circumferential length of 1,000 mm as in Example 1.

  In this endless belt-shaped metal mold, the period of the intermittent groove shape corresponds to 1 / 10,000 of the circumference of the endless belt-shaped metal mold, but the groove depth, groove bottom length, groove top length, and repetition period There was no problem and there was no problem in use as an endless belt-shaped metal mold.

(Example 5)
An endless belt-shaped metal mold was prepared in the same manner as in Example 1 except that three stainless steel plates were used and the circumference was changed to 1,500 mm. Using this endless belt-shaped metal mold, the thermal imprint shown in FIG. Imprint molding on a film was performed using an apparatus.

  For film 2, a three-layer laminated film in which polycarbonate resin was used as a core layer and polymethyl methacrylate (PMMA) resin was laminated on both sides as a transfer layer was prepared by coextrusion and used. The total thickness of the film was 200 μm, the lamination ratio (thickness ratio) of each layer was about 1: 8: 1, and the width was 320 mm.

  As the heating roll 4, a cylindrical core material made of carbon steel with hard chrome plating on the surface thereof was used. The outer diameter of the heating roll 4 was 180 mm, and the length in the width direction was 304 mm. An induction heating device provided inside the heating roll was used as the heating means, and the surface temperature of the heating roll 4 was heated to 210 ° C.

  As with the heating roll 4, the cooling roll 5 was made of carbon steel as a core material and hard chrome plated on the surface. The cooling roll 5 was always kept at a surface temperature of 50 ° C. by running water circulating inside.

  As the nip roll 6, a surface of a cylindrical core material made of carbon steel having an outer diameter of 160 mm was coated with a polyester resin (hardness: Shore D80 °) with a thickness of 20 mm as the elastic layer 11.

  The narrow pressure means 14 was loaded with a pressing force of 180 kN on the nip roll 6 using a pneumatic cylinder. At this time, when the contact width B between the nip roll 6 and the molding film 2 was confirmed using a pressure measurement film (Prescale, manufactured by Fuji Film Co., Ltd.), the total width was 6 mm, and the molding film 2 was loaded. The pressure was 100 MPa and was uniform in the width direction.

  When the film conveyance speed was gradually increased from 1 m / min to a maximum of 20 m / min, the endless belt-shaped metal mold was not broken at any speed, and the fine pattern processed into the endless belt-shaped metal mold was It was possible to transfer the film uniformly and continuously. When the V shape transferred onto the film at 20 m / min was measured, the pitch was 24.6 to 25.2 μm and the height was 12.2 to 12.5 μm.

(Comparative Example 1)
The same stainless steel plate as in Example 1 was used, and plating and grooving were performed in the same manner as in Example 1 except that the entire surface (500 mm × 300 mm) was plated without masking both ends during plating. Attempts were made to butt-weld the plate at the end, but the nickel burn-out during the welding became an impurity and the strength did not come out, so that it could not be formed as an endless belt-shaped metal mold.

(Comparative Example 2)
The same four stainless steel plates as in Example 3 were welded together to form a belt-like metal mold with a circumference of 2,000 m, and then the endless belt was placed on a rigid roll having a circumference equal to the circumference of the endless belt-like metal mold. The metal mold was fitted, and 0.1 mm nickel plating was performed in the fitted state, and the plated layer was grooved with a diamond tool. For grooving, there is no high-precision lathe machine with a rigid roll fixed to a lathe machine and a circumference of 2,000 m, that is, a metal mold with an endless belt diameter of 636.620 mm. The V-shaped pitch accuracy was 23.5 to 26 μm, and the depth accuracy was 11 to 13.5 μm. Moreover, the problem that the ridgeline part deform | transformed in a part of groove | channel by the process nonuniformity considered to originate in the shake of a processing machine arose.

1: Fine pattern transfer film manufacturing apparatus 2: Molding film 2a: Molding film molding surface 3: Endless belt-shaped metal mold 3a: Endless belt-shaped metal mold fine pattern surface 4: Heating roll 5: Cooling roll 6: Nip roll 7: Peeling roll 8: Guide roll 9: Unwinding roll 10: Winding roll 11: Elastic layer 13: Bearing 14: Narrow pressure means 15: Rigid flat plate 16: Masking tape 31: Base layer 32: Plating layer 33 : Metal flat plate 34: Base layer exposed portion 35: Fine pattern

Claims (7)

It is composed of one or more metal flat plates each having a base layer and a plating layer made of stainless steel. The base layer is exposed at the end of the metal flat plate, and the base layers exposed at the end are butt-welded. An endless belt-like metal mold, wherein the plating layer has a fine pattern. A front Symbol plating layer is a nickel plating layer, the endless belt-shaped metal mold total thickness of is 0.05 to 0.3 mm, and the total thickness thickness of the endless belt-shaped metal mold of the nickel plating layer The endless belt-shaped metal mold according to claim 1, wherein the metal mold is an endless belt-shaped metal mold.   The fine pattern is periodically formed at least in the circumferential direction of the endless belt-shaped metal mold, and the relationship between the period P of the fine pattern and the peripheral length L of the endless belt-shaped metal mold The endless belt-shaped metal mold according to claim 1, wherein P ≦ L / 3,600.   The endless belt-shaped metal mold according to any one of claims 1 to 3, wherein a circumferential length L of the endless belt-shaped metal mold is 2,000 mm or more. After plating one end of the base layer made of stainless steel, excluding an end, forming a plating layer, and forming one or more metal flat plates having the base layer and the plating layer , the plating layer A fine pattern is formed by cutting, and then the plating layer on which the fine pattern is formed is an outer surface, and the base layers of the end portions of the metal flat plate are attached to each other and welded to form an endless belt. To manufacture an endless belt-shaped metal mold.   The metal flat plate is a plurality of metal flat plates including at least a first metal flat plate and a second metal flat plate, the first fine pattern formed on the plating layer of the first metal flat plate, 6. The method of manufacturing an endless belt-shaped metal mold according to claim 5, wherein the second fine pattern formed on the plating layer of the second metal flat plate is a different pattern.   The endless belt-shaped metal mold according to any one of claims 1 to 4, or the endless belt-shaped metal mold manufactured by the manufacturing method according to claim 5 or 6, and the endless belt-shaped metal mold. A heating roll for heating the heating roll, a nip roll arranged in parallel with the heating roll, and a pressing mechanism comprising at least a clamping means using both rolls, and for cooling the endless belt-shaped metal mold A cooling roll, a peeling roll for peeling a film adhered to the endless belt-shaped metal mold, and a transport mechanism for transporting the endless belt-shaped metal mold by rotating the heating roll and / or the cooling roll. And a fine pattern transfer film manufacturing apparatus.