JP2005035099A - Manufacturing method of embossing roll and manufacturing method of transrfer sheet using the embossing roll - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an embossing roll little in the effect of a joint and having a fine uneven pattern on its surface, and a manufacturing method of a transfer sheet excellent in productivity and economical efficiency using the embossing roll. <P>SOLUTION: The embossing roll having the fine uneven pattern on its surface is manufactured using a flat plate having the fine uneven pattern formed on its surface. This manufacturing method has a process for processing the flat plate into a cylindrical shape and a process for fitting a support roll 20 to the inner peripheral part of the processed cylindrical body 18 in a cooled state. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an embossing roll and a method for producing a transfer sheet using the embossing roll, and in particular, to a method for producing an embossing roll in which a regular fine uneven pattern is formed on the outer peripheral surface of the roll, and using the embossing roll. The present invention relates to a method for producing a transfer sheet suitable for producing a sheet-like material such as an optical sheet.
[0002]
[Prior art]
Conventionally, optical lenses such as flat lenses such as lenticular lenses and fly-eye lenses, light diffusion sheets for use in electronic displays, antireflection sheets, brightness enhancement sheets, and optical waveguide sheets have been used. Production of such a sheet-like product is roughly classified into one by press molding using a flat plate mold and one by roll molding using an embossing roll.
[0003]
Of these, the production of those having a fine concavo-convex pattern on the surface is generally performed by press molding. The reason is that if it is flat, it is easy to finely process the press mold (for example, photoetching). On the other hand, press molding also has the disadvantage of being inferior in productivity. That is, a raw sheet and a press die are stacked, set in a hot press, and heated and pressure-molded. The cycle time of one batch is long (for example, about 1 hour), and multistage hot Even if a press is used, productivity is poor.
[0004]
On the other hand, according to roll forming, continuous processing is easy and productivity is excellent. On the other hand, there is a problem that it is difficult to finely process the embossing roll used for roll forming. As a proposal to cope with this problem, there is a configuration in which a roll stamper is manufactured using a flexible exposure mask (see Patent Document 1).
[0005]
Moreover, the structure which winds the metal plate-shaped metal mold | die which has a fine uneven | corrugated pattern on the surface around the outer periphery of a support roll, and manufactures an embossing roll is also considered. Such a thin flat plate winding technique is widely used in the field of printing, and various methods have been proposed (for example, see Non-Patent Document 1).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2-110841
[Non-Patent Document 1]
New printing technology introduction, pages 72, 73, published by the Japan Society for Printing Science, October 2001 (by Kazuhito Izumi)
[0008]
[Problems to be solved by the invention]
However, as in the conventional proposal (Patent Document 1), in a configuration in which fine processing is performed using an exposure mask, an endless (seamless) pattern cannot be formed on the roll surface. That is, the finer the pattern, the more difficult it is to form the seam continuously, and the use of an exposure mask having the property of adapting to the roll does not solve this point.
[0009]
In addition, when a thin plate-shaped mold having a fine uneven pattern on the surface is manufactured and this is wound around the outer periphery of a support roll to produce an emboss roll, it is inevitable that a seam will be generated. It is also difficult to improve the roundness of the. Furthermore, there is a problem that stress concentration is likely to occur in the wound portion and the structure becomes unstable.
[0010]
The present invention has been made in view of such circumstances, and has little influence on the seam, and a method for producing an embossing roll having a fine concavo-convex pattern on the surface, and productivity and economy using the embossing roll. It aims at providing the manufacturing method of the outstanding transfer sheet.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a method for producing an embossing roll, wherein a flat plate having a fine unevenness pattern formed on the surface thereof is used to produce an embossing roll having the fine unevenness pattern on the roll surface. There is provided a method for producing an embossing roll, comprising: a step of processing a flat plate into a cylindrical shape; and a step of cooling and fitting a support roll to an inner peripheral portion of the cylindrical object.
[0012]
According to the present invention, first, a flat plate having a fine uneven pattern formed on the surface is processed into a cylindrical shape. At this time, processing can be performed so that the influence of the joint of the flat plate is minimized. Then, a support roll is cooled and fitted inside the cylindrical object. Thereby, the roundness of an embossing roll can be made favorable.
[0013]
Here, the “cooling fit” is an operation performed based on the same technical idea as shrink fitting. “Shrink fit” means to fit a hole and shaft that do not fit at room temperature in a state where the hole is heated and expanded, and then shrink at room temperature to be firmly fixed. Say. On the other hand, “cooling fit” here refers to a cylindrical object and a support roll that do not fit in at room temperature, and are inserted in a state in which the support roll is cooled and contracted, and then expand at room temperature. It means to be fixed firmly.
[0014]
In this invention, it is preferable that the quantity of the said cooling fitting is 0.1 mm or more in the operating temperature of an embossing roll. This is because such an amount of cooling fit can practically endure the use of the embossing roll, and the cooling fit can be surely performed.
[0015]
Moreover, in this invention, it is preferable to supply a fluid to the clearance gap between the inner periphery of the said cylindrical object, and the outer periphery of the said support roll in the process of carrying out the cooling fitting. Thus, if a fluid is supplied to the gap between the cylindrical object and the support roll, this fluid exhibits the effect of lubrication and the fitting operation can be performed smoothly. The fluid can be gas or liquid.
[0016]
Moreover, in this invention, it is preferable that the said flat plate is a metal plate transcribe | transferred from the original disk in which the fine uneven | corrugated pattern was formed in the surface. When used as an embossing roll, the roll surface is usually required to have a predetermined hardness or higher, a modulus of elasticity in elasticity (Young's modulus), etc., but a metal plate will satisfy these requirements. Further, even if the fine uneven pattern cannot be directly formed on the metal plate, the fine uneven pattern can be formed on the surface of a master disk made of a suitable material and transferred to the metal plate by electroforming or the like. For example, a nickel alloy by electroforming can satisfy the transfer shape and mechanical performance (hardness, etc.).
[0017]
Moreover, this invention provides the manufacturing method of the transfer sheet | seat characterized by forming a fine uneven | corrugated pattern in the surface of a sheet-like material using said embossing roll. According to the present invention, since continuous forming with a roll can be performed, quality stability and productivity are greatly improved as compared with batch processing by hot pressing, and cost can be greatly reduced.
[0018]
In addition, as a formation method of the fine concavo-convex pattern using an embossing roll, not only embossing by a roll (with heating and pressurization), but also a molding process using UV resin and ultraviolet rays, a molding process using an EB solution, and a roll Various processing methods such as casting processing, extrusion molding processing, solution casting method and the like can be adopted.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a method for producing an embossing roll and a method for producing a transfer sheet using the embossing roll according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view illustrating a manufacturing flow of a pattern plate which is a flat plate having a fine uneven pattern formed on the surface.
[0020]
A 150 mm square silicon substrate was prepared as the substrate 12 used as a raw material for the pattern plate 10. A resist 14 was applied to the surface of the substrate 12 to a predetermined thickness and pre-baked (the state shown in FIG. 1A). In order to improve the adhesion between the substrate 12 and the resist 14, a base treatment such as coating of a coupling agent, formation of a metal oxide film, or the like can be employed.
[0021]
A photomask (not shown) is placed on the surface of the resist 14 layer, and exposure and development processes are performed, so that the state shown in FIG. 1B is obtained, and predetermined openings 14a, 14a,. The
[0022]
By performing etching after post-baking, the state shown in FIG. 1C is obtained, and when the resist 14 is further peeled, the state shown in FIG. 1D is obtained and a fine uneven pattern is formed on the surface of the substrate 12. It becomes. The fine concavo-convex pattern has a groove shape, a pitch of 1.5 μm, a width of 1.0 μm, and a depth of 0.06 μm. This fine concavo-convex pattern is formed on substantially the entire surface of the substrate 12. This substrate 12 becomes a master.
[0023]
Next, electroless plating is performed on the surface of the substrate 12 to form a contact layer, and then an electroforming process is performed to form this inverted mold (the state shown in FIG. 1E). As the metal material used for the electroforming process, for example, a material mainly composed of nickel can be preferably used. The inverted mold obtained by the electroforming process is used as the mother mold 16 hereinafter. FIG. 1 (f) shows a state where the mother die 16 is peeled off from the substrate 12 as a master.
[0024]
Using this matrix 16, a pattern plate 10 having the same surface shape as that of the master is formed by electroforming. FIG. 1G shows a process for forming the pattern plate 10. At this time, a matrix 16 having a size of 150 mm square was arranged in a row, and a pattern plate 10 having a planar size of 200 × 629 mm and a thickness of 200 μm was obtained. In addition, the space | interval of each matrix 16 was 10 mm.
[0025]
Next, this pattern board 10 is processed into a cylindrical shape. FIG. 2 is a schematic view for explaining a method of forming this cylindrical object. In order to form the cylindrical object 18, it is necessary to join both ends of the pattern plate 10. As this joining method, various means can be employed, but laser welding, EB welding (electron beam welding), etc., which can reduce the joint portion 18a, can be preferably employed. When the joining portion 18a rises to the outer peripheral side, it is preferable to correct it by performing polishing or the like as needed. The cylindrical object 18 shown in FIG. 2 was processed so that the inner diameter was 200 mm.
[0026]
In the conventional method of directly attaching a plate on which a pattern is formed to a roll, a large gap is formed in the joint portion or it is difficult to correct the joint portion. By forming as 18, it becomes easy to correct the joint portion 18a.
[0027]
Next, the embossing roll 22 is formed by cooling the support roll 20 on the inner peripheral portion of the cylindrical object 18. FIG. 3 is a schematic view for explaining a method for forming the embossing roll 22. As the support roll 20, an S45C roll having an outer diameter of 200.15 mm and an effective length of 200 mm was used. The cylindrical object 18 was maintained at room temperature, while the support roll 20 was cooled with dry ice until the outer diameter became 199.85 mm, and then the support roll 20 was fitted into the cylindrical object 18. FIGS. 3A and 3B show this process.
[0028]
In this invention, this amount of fitting is important, and it is preferable that the amount of cooling fitting is 0.1 mm or more in the use temperature of an embossing roll, and it is more preferable that it is 0.3 mm or more. The amount of the cooling fit is not particularly limited as long as it is within the breaking strength of the cylindrical object 18, but when the amount of the cooling fit is set excessively, the operation of the cooling fit is difficult.
[0029]
The processing temperature at the time of manufacturing a transfer sheet using this embossing roll is around 150 degrees C. Although the thermal expansion coefficient of nickel of the cylindrical object 18 is larger than the thermal expansion coefficient of S45C of the support roll 20, a cooling fit amount of 0.1 mm or more can be secured within this processing temperature range. Never become.
[0030]
In addition, when the processing temperature at the time of manufacturing a transfer sheet using an embossing roll is higher, it is necessary to enlarge the outer diameter of the support roll 20 and to further increase the amount of cooling fit.
[0031]
If the material of the support roll 20 is stainless steel having a coefficient of thermal expansion larger than that of nickel, the higher the processing temperature at the time of manufacturing the transfer sheet, the stronger the fit, which is preferable. There is also a restriction that the processing pressure cannot be increased too much.
[0032]
In the present embodiment, it is based on the viewpoint of the heat capacity of the member that a cooling fit is used instead of the conventional shrinkage fit. That is, the cylindrical object 18 has a small plate thickness (in this example, 200 μm), a small heat capacity, and can easily return to room temperature in a short time even when heated. On the other hand, the support roll 20 is formed from a thick cylindrical member or a columnar material made of a bulk material and has a large heat capacity from the viewpoint of ensuring strength during use. Therefore, even after cooling, it is difficult to return to room temperature in a short time, and workability is good.
[0033]
At this time, compressed air was supplied to the gap between the inner periphery of the cylindrical object 18 and the outer periphery of the support roll 20 in the cooling fitting process. Thereby, the cooling fit was facilitated by the action of the air cushion (this compressed air exerts a lubricating effect). The fluid supplied at this time is not limited to compressed air, but may be other gas (for example, nitrogen gas) or liquid (for example, water, lubricant).
[0034]
As a method of supplying compressed air to the gap between the inner periphery of the cylindrical object 18 and the outer periphery of the support roll 20, for example, a large number of fine gas ejection holes are formed on the outer periphery of the support roll 20. A configuration may be adopted in which compressed air is supplied from the shaft end via the inside of the support roll 20.
[0035]
As described above, the method of fitting the support roll 20 into the cylindrical object 18 while supplying compressed air to the gap between the inner periphery of the cylindrical object 18 and the outer periphery of the support roll 20 is another technical field (for example, non- Although it can be seen in Patent Document 1), there has been no example of the transfer sheet manufacturing method employed so far. The present invention relates to a technique for forming a cylindrical object 18 from the pattern plate 10, cooling fitting between the support roll 20 and the cylindrical object 18, and supplying a fluid to a gap between the cylindrical object 18 and the support roll 20. The combination provides an embossing roll manufacturing method with good accuracy.
[0036]
Note that the pressure of the fluid to be supplied is preferably 980 MPa (10 kg / cm ² ) or more. By setting the pressure of such a fluid, the cylindrical object 18 is expanded in the radial direction, and the fitting operation can be performed smoothly.
[0037]
When the cooling fit between the support roll 20 and the cylindrical object 18 is finished and the formed embossing roll 22 returns to normal temperature, the support roll 20 expands and forms a fitted state with the cylindrical object 18. The embossing roll 22 is integrated.
[0038]
Next, the process of forming a fine concavo-convex pattern on the surface of the sheet-like material using the embossing roll 22 will be described. FIG. 4 is a schematic view for explaining a transfer sheet forming method.
[0039]
In FIG. 4, a raw material sheet (sheet-like material) W fed out from a raw roll 24 at a predetermined speed is preheated to a predetermined temperature by a preheating device 26 from both sides. The raw material sheet W is sandwiched between the embossing roll 22 and the nip roll 28 maintained at the processing temperature, and is subjected to embossing processing by being heated and pressurized. Next, the raw material sheet W is peeled off from the embossing roll 22 by being wound around the guide roll 30, cooled by the cooling device 32 from both sides, and then wound around the winding roll 36 as the transfer sheet 34.
[0040]
As the material of the raw material sheet (sheet-like material) W, various resin materials can be used. For example, polyvinyl chloride (PVC), polypropylene (PP), polyethylene, polyester, ethylene vinyl acetate (EVA), etc. are preferable. Can be used. Moreover, the sheet-like material which comprised the some resin material in 2 layers or 3 layers can also be used.
[0041]
When the use of the transfer sheet 34 is a flat lens such as a lenticular lens, or a transparent body such as a light diffusion sheet for electronic display, a transparent resin material or the like can be used for the raw material sheet W. On the other hand, when the application of the transfer sheet 34 is a reflector such as an antireflection sheet for use in electronic displays, the raw material sheet W is, for example, a laminate sheet having a three-layer structure in which an intermediate layer is provided with an aluminum film. it can.
[0042]
In the illustrated example, the preheating device 26 employs radiant heating by a heater, but the preheating device 26 is not limited to this, and various methods can be employed.
[0043]
Examples of the heating means for the embossing roll 22 and the nip roll 28 include a configuration in which a heat medium is circulated in the roll via a rotary joint, a configuration in which a sheath heater is disposed in the roll, and a configuration in which a heating means is provided in the vicinity of the surface of the roll. Can be adopted. The processing temperature and processing pressure can be appropriately selected depending on the pattern shape on the surface of the embossing roll 22, the material of the raw material sheet W, the traveling speed of the raw material sheet W, and the like.
[0044]
In the illustrated example, the cooling device 32 employs a cooling method using air blow, but is not limited thereto, and various methods can be employed.
[0045]
In addition, as a formation method of the fine uneven | corrugated pattern using an embossing roll, not only the embossing by a roll as shown in FIG. 4 but the shaping | molding process using UV resin and an ultraviolet-ray, the shaping | molding process using an EB solution, and a roll Various processing methods such as casting processing (used as a casting roll), extrusion molding processing, solution film forming method (used as a seamless belt / casting roll) can be employed. Since these are known techniques, detailed description thereof is omitted.
[0046]
For example, in the case of a molding process using UV resin and ultraviolet rays, a UV resin (ultraviolet curable resin) having a predetermined thickness is formed on a web for transportation (band-like flexible support), and the embossing roll 22 converts the UV resin into the UV resin. Immediately after the embossing process, UV rays are irradiated to cure the UV resin.
[0047]
As mentioned above, although the example of embodiment of the manufacturing method of the embossing roll which concerns on this invention, and the manufacturing method of the transfer sheet using this embossing roll was demonstrated, this invention is not limited to the example of the said embodiment, Various aspects Can be taken.
[0048]
For example, in the present embodiment, the mother die 16 and the pattern plate 10 are formed by electroforming. However, when the electroforming is difficult, the substrate 12 as a master can be directly processed into the pattern plate 10. . At this time, a portion of the pattern plate 10 on which the substrate 12 is arranged is cut out in advance, and after the substrate 12 is fitted, the pattern plate 10 and the substrate 12 are fixed by welding or the like.
[0049]
Moreover, in this embodiment, although the fine uneven | corrugated pattern formation of the board | substrate 12 used for the raw material of the pattern board 10 was made | formed by photoetching, various other well-known methods, for example, laser processing, ultrasonic processing, etc. Processing methods can be adopted.
[0050]
【The invention's effect】
As described above, according to the present invention, first, a flat plate having a fine uneven pattern formed on the surface is processed into a cylindrical shape. At this time, processing can be performed so that the influence of the joint of the flat plate is minimized. Then, a support roll is cooled and fitted inside the cylindrical object. Thereby, the roundness of an embossing roll can be made favorable.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a manufacturing flow of a pattern plate. FIG. 2 is a schematic diagram illustrating a method for forming a cylindrical object. FIG. 3 is a schematic diagram illustrating a method for forming an embossing roll. Schematic explaining the formation method 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 10 ... Pattern board, 12 ... Board | substrate, 14 ... Resist, 16 ... Master mold, 18 ... Cylindrical thing, 20 ... Support roll, 22 ... Embossing roll, 24 ... Original fabric roll, 26 ... Preheating apparatus, 28 ... Nip roll, 30 ... guide roll, 32 ... cooling device, 34 ... transfer sheet, 36 ... winding roll, W ... raw material sheet (sheet-like material)

Claims (5)

Using a flat plate having a fine concavo-convex pattern formed on the surface, an embossing roll manufacturing method for producing an embossing roll having the fine concavo-convex pattern on the roll surface,
Processing the flat plate into a cylindrical shape;
Cooling and fitting a support roll to the inner peripheral portion of the cylindrical object;
A process for producing an embossing roll, comprising: The manufacturing method of the embossing roll of Claim 1 whose quantity of the said cooling fitting is 0.1 mm or more in the operating temperature of an embossing roll. The manufacturing method of the embossing roll of any one of Claim 1 or 2 which supplies a fluid to the clearance gap between the inner periphery of the said cylindrical object, and the outer periphery of the said support roll in the said cooling fitting process. The method for producing an embossing roll according to any one of claims 1, 2, and 3, wherein the flat plate is a metal plate transferred from a master having a fine uneven pattern formed on a surface thereof. A method for producing a transfer sheet, wherein a fine uneven pattern is formed on the surface of a sheet-like material using the embossing roll according to claim 1.

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