JP2001150453A - Method of manufacturing transfer mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a transfer mold capable of forming a suitable transfer mold free from burr and excellent in practicality and productivity. SOLUTION: In a method of manufacturing a transfer mold for manufacturing a member having a fine shape such as a prism sheet, Flesnel lens or a light guide plate by transfer, transfer is repeated from a matrix 2 having a fine shape formed thereon to form a burr recessed mold wherein a burr shape is positioned at a recessed place and becomes concave and, succeedingly, the burr recessed mold is coated with a resin solution low in viscosity to fill the burr shape to use the burr recessed mold wherein the burr shape is filled as a transfer mold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer mold manufacturing method.

[0002]

2. Description of the Related Art As a method of forming a transfer mold for manufacturing a lens member having periodicity or quasi-periodicity such as a prism sheet, a Fresnel lens, a light guide plate, etc. by transfer, a general method is used. Then, a metal mold having good machinability, such as oxygen-free copper, brass, phosphor bronze, or the like, is cut with a cutting tool to form a desired fine shape. A method has been proposed in which a mold is formed, and subsequently, a resin transfer mold (symbol 10 in FIG. 1 (c) in FIG. 1) is formed from the electroforming mold. The lens member is mass-produced using the resin transfer mold (hereinafter, referred to as a conventional transfer mold manufacturing method).

In this conventional transfer mold manufacturing method, a high cutting accuracy is required for a lens member such as a prism sheet. Therefore, a diamond chip made of diamond single crystal is used as a cutting tool in order to cut and form the matrix. In addition, the diamond tip is extremely expensive, and in consideration of the durability of the diamond tip, the matrix is made of the metal material having good machinability.

However, since these soft members are all sticky materials, burrs are easily generated during cutting.

This burr remains as it is on the electroforming mold as a recess and further as a protrusion on the resin transfer mold. Therefore, for example, when the product is a prism sheet (a sheet on which prism-shaped protrusions are juxtaposed), the protrusion is formed. Appears between the strips as the convex negative type concave.

The burrs have a property that they are more easily formed as the cutting speed is lower or the engraving depth is deeper. Therefore, as a method of solving this burr problem, a method of preventing burr generation, and
There is a method of removing the formed burrs.

[0007] As a method of preventing the generation of burrs, there is a method of reducing the engraving amount at the time of cutting and increasing the cutting speed. In this method, cutting is performed in order to obtain a desired fine shape. It is necessary to repeat the cutting, the cutting has a long time, and when electric cutting is performed, there is a problem that the amount of cutting becomes non-uniform due to fluctuations in voltage, and a high-accuracy mother die cannot be manufactured.

As a method for removing the formed burrs, there is a jet cleaning means for spraying a liquid onto a matrix. However, this method cannot spray the liquid only on fine burrs. Excessive cleaning may damage parts other than burrs, making it difficult to remove burrs evenly, and drying to remove liquid remaining on the finely shaped surface after cleaning. A step is required, and this drying step also needs to be able to prevent the occurrence of rust and the occurrence of uneven drying, which is problematic in that the production is troublesome and the cost is high.

The present invention solves the above problems,
Rather than removing the burrs formed on the mother mold, the burrs are filled in the transfer process, so that a suitable transfer mold without burrs can be formed. To provide.

[0010]

The gist of the present invention will be described with reference to the accompanying drawings.

A method of manufacturing a transfer mold for manufacturing a member having a fine shape such as a prism sheet, a Fresnel lens, a light guide plate, etc. by transfer, wherein the transfer is repeated from the mother die 2 on which the fine shape is formed, and the burr shape is depressed. Forming a depressed burr shape in which the burr shape is located at a place and then coating the burr shape with a low-viscosity resin solution to fill the burr shape and transfer the burr shape filled with the burr shape The present invention relates to a method for manufacturing a transfer die, which is characterized in that it is a die.

Further, in the method of manufacturing a transfer die according to the first aspect, the fine shape formed on the mother die 2 is formed by cutting.

In the method for manufacturing a transfer die according to any one of claims 1 and 2, the fine shape is a fine shape having periodicity or quasi-periodicity formed on a prism sheet, a Fresnel lens, a light guide plate, or the like. The present invention relates to a method for manufacturing a transfer die, which is characterized in that the transfer die has a shape.

Further, in the method for producing a transfer mold according to any one of claims 1 to 3, a resin solution having a viscosity at the time of coating of 5 mPa · s or less is used as the resin solution having a low viscosity. The present invention relates to a transfer mold manufacturing method.

Further, a prism sheet, a Fresnel lens,
A method of manufacturing a transfer mold for manufacturing a lens member provided with a fine shape having periodicity or quasi-periodicity such as a light guide plate by transfer. Is located in the recess and forms an electroforming mold or a resin transfer mold so that the burr shape is concave,
The electroforming mold or the resin transfer mold is coated with a low-viscosity resin solution, and subsequently, a drying process is performed to fill the burr shape with the resin 11, and the burr shape in which the burr shape is embedded is used as a transfer mold. And a method for manufacturing a transfer mold.

A mother member having a fine shape in which a metal member having good machinability, such as oxygen-free copper, brass or phosphor bronze, is cut by a cutting tool such as a diamond chip, and ridges 3 are juxtaposed from the member. The mold 2 is formed, and then an electroforming material such as nickel is provided on the matrix 2 to form an electroforming mold 6 based on the electroforming method in which the negative ridge 5 of the ridge 3 is transferred. ,
Subsequently, a silicone resin is poured onto the electroforming mold 6 to form the first silicone resin mold 8 on which the negative ridges 7 of the concave stripes 5 are transferred. A resin is poured to form an epoxy resin mold 10 to which the concave stripe 9 which is a negative type of the convex stripe 7 is transferred.
A low-viscosity resin solution is dip-coated on the fine-shaped surface of the epoxy resin mold 10, and then the low-viscosity resin solution is dried to fill the burr shape at the bottom of the concave streak 9 with the resin 11. Then, a silicone resin is poured onto the epoxy resin mold 10 to form a second silicone resin mold 13 on which the negative ridge 12 of the concave stripe 9 is transferred. A method of manufacturing a transfer die, comprising forming a transfer die 15 made of epoxy resin for forming the lens member onto which a concave groove 14 which is a negative type of the convex stripe 7 is transferred by pouring a resin. It is.

[0017]

Operation and effect of the present invention For example, a burr 4 formed in a fine shape of a matrix 2 having a fine shape formed by cutting or the like.
In the process of forming a transfer mold by repeating transfer from the matrix 2, a burr recess is provided in which the burr shape is located in the recess and the burr shape is concave, and a resin solution having a low viscosity is provided in the burr recess. Is applied, the recess is filled with the resin 11, and the burr is not filled in the product such as a lens member or the like formed from the recessed burr-filled mold, that is, the transfer mold.

Since the present invention is as described above, it is possible to easily form a suitable transfer mold without burrs.
It becomes a production method of a transfer type excellent in productivity.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate one embodiment of the present invention and will be described below.

The present embodiment relates to a method for manufacturing a transfer die for manufacturing a lens member provided with a periodic or quasi-periodic fine shape, such as a prism sheet, a Fresnel lens, and a light guide plate, by transfer. The transfer is repeated from the mother die 2 on which the burr shape is located in the concave portion and the burr shape is formed to be concave, so that an electroforming mold or a resin transfer mold is formed. Is coated with a low-viscosity resin solution, followed by a drying treatment to fill the burr shape with the resin 11, and to use the burr concave shape in which the burr shape is buried as a transfer type.

Hereinafter, specific steps will be described in detail.

First, a metal member having good machinability such as oxygen-free copper, brass or phosphor bronze is cut by a cutting tool such as a diamond chip, and a matrix 2 having a fine shape (positive type) formed from the member. Is formed (see FIG. 1A).

The illustrated fine shape (positive type) has periodicity in which the ridges 3 having a prism shape in a sectional view are arranged side by side, but the same applies to other fine shapes. A burr 4 is formed at the tip of the ridge 3 during the cutting.

Subsequently, an electroforming material such as nickel is provided on the matrix 2 to form an electroforming mold 6 based on an electroforming method in which the negative ridge 5 of the ridge 3 is transferred. In this electroforming mold 6, the burr 4 is transferred as a recess at the bottom position of the concave streak 5 (see FIG. 1B). It should be noted that only a few electroforming molds 6 can be formed from the matrix 2 due to the problem of mold release.

Subsequently, a silicone resin is poured onto the electroforming mold 6 to form a silicone resin mold 8 on which the negative ridges 7 of the concave stripes 5 are transferred. In the silicone resin mold 8, the burr shape is transferred as a protrusion to the tip position of the ridge 7 (see FIG. 1C). Since the silicone resin 8 is a soft material, the silicone resin mold 8 can be easily removed from the mold and can be formed in large numbers from the electroforming mold 6.

Subsequently, an epoxy resin is poured onto the silicone resin mold 8 to form an epoxy resin mold 10 to which the concave ridges 9 which are the negative type of the ridges 7 are transferred. In the epoxy resin mold 10, the burr shape is transferred as a recess at the bottom position of the concave streak 9 (see FIG. 1D). In addition, epoxy resin type
In 10, since the silicone resin mold 8, which is the mother mold, is a soft material, the mold can be easily removed, and a large number can be formed from the silicone resin mold 8.

Subsequently, a low-viscosity resin solution is dip-coated on the fine-shaped surface of the epoxy resin mold 10, and the low-viscosity resin solution is dried, and the low-viscosity resin solution adhered to the epoxy resin mold 10 is dried. Of the solution components are evaporated
Eleven components remain (see FIG. 1 (e)).

At this time, the resin solution having a low viscosity is coated on the entire surface of the fine shape of the epoxy resin mold 10 by a dip coating process. The drying speed is slow at the bottom position of the ridge 9 due to the liquid depth of the solution and the capillary condensation phenomenon, and therefore, the resin 11 in the resin solution having a low viscosity in the bottom position of the ridge 9 and the concave at the bottom position. The component (solid content) is selectively accumulated, the resin 11 is dried and solidified at the position, and the recesses on which the burrs are transferred are filled.

The resin solution having a low viscosity may be, for example, a mold (an epoxy resin mold 10 in this embodiment, a depressed burr mold in the claims).
If the material is epoxy resin, and the fine shape is a shape in which convexes having a pitch of about 50 μm and an apex angle of about 60 to 90 ° are juxtaposed, it is preferable to use a resin solution having a viscosity of 5 mPa · s (millipascal second) or less. . As the resin solution having a viscosity of 5 mPa · s or less, a mixture of a fluorine-containing copolymer, tertiary butanol, and MIBK may be employed (in this case, the fluorine-containing copolymer is tertiary butanol and By diluting about 1 / 1,000 with MIBK, the solid content becomes 1% and the viscosity becomes about 5 mPa · s.) Further, a resin solution having a viscosity of about 2 mPa · s is more preferable. In addition, a resin solution having a low viscosity is
The use of a solution component having volatility is preferred because of its excellent drying properties. In addition, a resin solution having a low viscosity is preferably dip-coated so as to have a height difference of about 1/50 of a fine shape. The pulling speed when pulling up the epoxy resin mold 10 after the dip coating is set to 400 m so that the low-viscosity resin solution uniformly adheres to the finely-shaped surface.
It is good to be about m / s.

Depending on the size of the fine shape and the shape of the details, it is conceivable to use a high-viscosity resin solution for the coating treatment. However, in the case of the concave stripe in this case, the capillary condensation phenomenon does not occur. This makes it difficult to selectively attach the resin 11 to the recesses to which the burr shape has been transferred, thereby increasing the possibility of a burr processing failure and adversely affecting the optical characteristics of the optical member finally formed. . In addition, since a resin solution having a high viscosity has poor leveling properties, uneven adhesion occurs to a finely-shaped surface, and the optical characteristics of an optical member finally formed are adversely affected as described above. Therefore, as described above, a resin solution having a small surface tension, that is, a resin solution having a low viscosity must be used as the resin solution used for the dip coating treatment. Further, a coating process other than the dip coating, for example, a coating process may be employed.

Even when the resin solution having a low viscosity is dip-coated as in this embodiment, the bottom of the concave stripe 9 is rounded, and a product slightly different from the expected optical characteristics can be obtained. A slight rounding does not have a significant effect on the optical properties of the product. As a result of the experiment, no problem occurred in the optical characteristics of the product when the resin solution having a viscosity of 5 mPa · s was dip-coated.

After the dip coating step and the drying step, if a burr shape still remains in the epoxy resin mold 10, the burr shape is completely filled by repeating the dip coating step and the drying step.

Subsequently, a silicone resin is poured onto the epoxy resin mold 10 to form a second silicone resin mold 13 to which the negative ridge 12 of the concave stripe 9 is transferred. In the second silicone resin mold 13, there is no portion corresponding to the burr shape, and the top side of the ridge 12 is formed into a micro-rounded ridge 12 (see FIG. 1 (f)). . The second silicone resin mold 13 can be formed in large numbers from the epoxy resin mold 10 because the silicone resin is a soft material.

Subsequently, the epoxy resin on the second silicone resin mold 13 is poured, and the concave ridges 14 which are the negative type of the ridges 7 are formed.
Is transferred to form a transfer mold 15 made of epoxy resin (see FIG. 1 (g)). This transfer die 15 becomes the transfer die 15 for forming the lens member. The transfer mold 15 can be formed in large numbers from the second silicone resin mold 13 because the second silicone resin mold 13 as the mother mold is a soft material.

As described above, according to this embodiment, it is possible to mass-produce the lens member transfer mold 15 with no risk of forming burrs on the product at low cost.

In this embodiment, as described above, since the formed burrs 4 are not removed and the filling process is performed so that the burrs 4 are not transferred to the product, the portions other than the burrs 4 are not damaged and the burrs 4 are not damaged. This makes it possible to form a suitable transfer mold without any problem, and to provide a transfer mold manufacturing method excellent in practicality and productivity.

Further, since this burr treatment can be performed by incorporating it into the step of forming the transfer mold 15 for mass-producing products such as lens members, practicality, productivity, and cost can be easily modified. It is an excellent method of manufacturing a transfer mold.

Further, since this burr treatment is performed not on the expensive matrix 2 and the electroforming mold 4 but on the inexpensive resin-made epoxy resin mold 10, the expensive matrix 2 and the electroforming mold 4 are not used. This is a method of manufacturing a transfer mold excellent in practicality and productivity without the risk of wasting the mold 4.

Further, a resin solution having a low viscosity of 5 m
Since a resin solution of Pa · s or less is used and each part of the fine shape is selectively filled by utilizing the capillary condensation phenomenon, this resin has excellent practicality in which the optical characteristics of the lens member are not adversely affected. A transfer mold manufacturing method.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the present embodiment.

FIG. 2 is an explanatory diagram in a case where a high-viscosity resin solution 21 is dip-coated on an epoxy resin mold 10;

[Explanation of symbols]

 2 mother die 3 convex stripe 4 burr 5 concave stripe 6 electroforming mold 7 convex stripe 8 first silicone resin die 9 concave stripe 10 epoxy resin die 11 resin 12 convex stripe 13 second silicone resin die 14 concave stripe 15 transfer die

Claims (6)

[Claims] 1. A method of manufacturing a transfer die for manufacturing a member having a fine shape such as a prism sheet, a Fresnel lens, and a light guide plate by transfer, wherein a burr shape is formed by repeating transfer from a master having the fine shape formed thereon. A burr recessed mold is formed in which the burr shape is located in the recess and the burr shape is concave. Subsequently, the burr recessed mold is coated with a low-viscosity resin solution to fill the burr shape and fill the burr shape. A method for producing a transfer die, which is a transfer die. 2. The method for manufacturing a transfer die according to claim 1, wherein the fine shape formed on the mother die is formed by cutting. 3. The method for manufacturing a transfer die according to claim 1, wherein the fine shape is a prism sheet,
A method for producing a transfer die, characterized in that it has a fine shape having periodicity or quasi-periodicity formed on a Fresnel lens, a light guide plate or the like. 4. The method for producing a transfer mold according to claim 1, wherein the resin solution having a low viscosity has a viscosity of 5 mPa · s or less when coated. Transfer mold manufacturing method. 5. A method for manufacturing a transfer die for manufacturing a lens member provided with a fine shape having periodicity or quasi-periodicity, such as a prism sheet, a Fresnel lens, and a light guide plate, by transfer, wherein the fine shape is formed. The transfer is repeated from the master mold to form an electroforming mold or a resin transfer mold so that the burr shape is located in the recess and the burr shape is concave, and then the electroforming mold or the resin transfer mold has a low viscosity. A method of manufacturing a transfer die, comprising coating a resin solution and subsequently performing a drying treatment to fill the burr shape with the resin and to use a burr concave shape in which the burr shape is embedded as a transfer mold. 6. A matrix having a fine shape in which a metal member having good machinability, such as oxygen-free copper, brass or phosphor bronze, is cut by a cutting tool such as a diamond chip and ridges are juxtaposed from the member. Then, an electroforming material such as nickel is provided on the matrix to form an electroforming method based on the electroforming method in which the concave stripes, which are the negative types of the convex stripes, are transferred. A first silicone resin mold is formed by pouring a silicone resin onto the concave ridge, which is a concave ridge, and then an epoxy resin is poured onto the first silicone resin mold to form a ridge. An epoxy resin mold to which a certain concave stripe is transferred is formed, subsequently, a low-viscosity resin solution is dip-coated on a fine-shaped surface of the epoxy resin mold, and then the low-viscosity resin solution is dried to form the concave portion. The burr shape at the bottom of the strip is Filling, subsequently, a silicone resin is poured onto an epoxy resin mold to form a second silicone resin mold on which the ridges, which are the negative type of the concave stripes, are transferred. Subsequently, the epoxy resin is poured on the second silicone resin mold. A method of manufacturing a transfer die, comprising: forming a transfer die made of an epoxy resin for forming the lens member to which the negative-shaped concave stripe of the convex stripe is transferred.