JPH06155173A - Manufacture of metal mold for flat plate-shaped molded object - Google Patents

Abstract

PURPOSE:To provide a metal mold for manufacturing a flat plate-shaped molded object, having linear grooves of fine pitch, easily in high dimensional accuracy by cutting work in a short time. CONSTITUTION:A cut metal layer 10 is formed on a roll 1, to cut grooves in the cut metal layer 10 while rotating it with an axis of the roll serving as the center of rotation, and then the cut metal layer 10 is removed from the roll and formed into a flat plate shape, to manufacture a metal mold for a flat plate-shaped molded object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a die for a flat plate shaped article. More specifically, the present invention relates to a method of manufacturing a mold that enables a flat-shaped molded product having fine-pitch linear grooves such as a lenticular lens sheet to be obtained with high dimensional accuracy.

[0002]

2. Description of the Related Art Generally, a linear groove is formed on a lenticular lens sheet. As a method of manufacturing a flat plate-shaped molded product having such a linear groove, a predetermined mold is conventionally used. A roll extrusion molding method of extruding a molding target from between two rolls, a pressing method using a die manufactured by a surface grinder, a 2P method, and the like are used.
Further, it is also known that an inverted mold is obtained by an electroforming method using a product manufactured by some method as a mother mold, and an electroformed product similar to the mother mold is manufactured by using the reversed mold.

[0003]

However, when it is necessary to form linear grooves in the lenticular lens sheet at a fine pitch of 1 mm or less, further 0.5 mm or less, depending on the application. However, the conventional method has a problem that it is not possible to manufacture fine pitch grooves with high precision and in a short time as described below.

That is, in the roll extrusion method, when the shape of the roll has a fine pitch, the shape cannot be accurately transferred to the molded product and extruded.

In the pressing method and the 2P method, the relative movement (main movement) direction between the cutting tool and the surface to be cut becomes a straight line when the die to be used is manufactured by the surface grinder. Since vibration occurs in the movement, it is not possible to cut linear fine pitch grooves with high dimensional accuracy. For example, depth 3μ
When it is attempted to accurately cut a groove having a circular cross-sectional shape of m and a pitch of 0.1 mm over a length of 1 m, variations in depth and pitch become large. Further, in this case, the feed motion of the object to be cut becomes intermittent, and continuous cutting cannot be performed, so that it takes a long time for cutting. Furthermore, it is difficult to make the cutting surface clean because burrs are easily generated by cutting.On the other hand, in order to prevent burrs, it is sufficient to reduce the depth of cutting in each depth direction. If the cutting amount is reduced, it takes a longer time for the whole cutting.

The present invention is intended to solve the problems of the prior art as described above, and to make it possible to obtain a die for producing a flat plate-shaped molded article with high dimensional accuracy, in particular, a fine pitch straight line. Aims to achieve the desired dimensional accuracy even when forming a groove in the shape of a groove, and to easily obtain a mold with such a high dimensional accuracy by cutting in a short time. .

[0007]

SUMMARY OF THE INVENTION In order to obtain a molded article having a fine pitch linear groove with high dimensional accuracy, the inventors of the present invention use a flat die to perform a pressing method or a 2P method.
It is preferable to mold by a method, and as a method for producing such a plate-shaped mold with high dimensional accuracy, a metal layer to be the mold is placed on a roll instead of cutting the mold with a surface grinder. Found that it is effective to perform cutting while rotating the metal layer around the axis of the roll, remove the metal layer from the roll after cutting, and form a flat plate, and completed the present invention. It was

That is, according to the present invention, a metal layer to be cut is formed on a roll, the metal layer to be cut is cut while rotating the metal layer to be cut around the axis of the roll, and then the metal to be cut is cut. Disclosed is a method for producing a mold for a flat plate-shaped molded product, which comprises removing a layer from a roll to form a flat plate.

The manufacturing method of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a schematic perspective view of a cutting device that can be used for implementing the present invention. In this cutting device, an object to be cut is attached to the outer periphery of the roll 1, and the object to be cut is cut with a cutting blade 2 while rotating the roll 1 in the direction of the arrow with the roll shaft 1a as the center of rotation. In this case, the cutting tool 2
Is to be attached to the tool rest 4 on the carriage 3, and the cutting depth of the cutting groove is adjusted by adjusting the position thereof in the x-axis direction, and the position of the cutting tool is adjusted in the z-axis direction. This allows the pitch of the cutting groove to be adjusted. As such a cutting device, a lathe generally used for roll outer circumference cutting can be used.

In the manufacturing method of the present invention, first, a metal layer to be cut is formed on the roll 1 of such a cutting device.
The method for forming such a metal layer to be cut is not particularly limited, and a suitable metal layer to be cut can be formed by plating, for example. In this case, the plating thickness is 0.
It is preferably 5 mm to 1.5 mm.

When forming the metal layer to be cut, FIG.
As in (a), the metal layer 10 to be cut is formed directly on the roll 1 via the release layer 5 without being directly formed on the roll 1, and the metal layer 10 to be cut is easily removed from the roll 1 after cutting. It is preferable to be able to peel it off. As such a peeling layer 5, for example, a metal oxide film layer, an organic material layer such as grease, or the like can be formed.

A metal layer such as copper formed by plating or thermal spraying can be formed between the roll 1 and the peeling layer 5 as the protective layer 6 of the roll 1.

In the present invention, the cutting of the metal layer to be cut formed on the roll can be performed in the same manner as a known cutting method using a lathe.

After cutting, the metal layer to be cut is cut open,
The roll 1 is removed to form a flat plate-shaped mold as shown in FIG. In this case, as a method for cutting open the metal layer to be cut after cutting, for example, it is preferable to attach an air sander to the tool post of the lathe and cut in the axial direction. It is preferable to fix the mold end to the flat frame.

When the strength of the obtained plate-shaped die on the machined surface is not sufficient and is easily scratched, a metal layer harder than the metal layer to be cut is formed on the machined surface of the plane-shaped mold. Preferably. The method of forming such a reinforcing metal layer is not particularly limited, and for example, a metal layer of Ni, Cr or the like can be formed by plating. In addition, the plating thickness in this case is appropriately determined in consideration of the strength required for the flat plate mold, the shape change due to plating, etc. Make the thickness sufficiently thin with respect to the depth.

If it is difficult to form a desired linear groove by the above-described method for manufacturing a flat mold, a mold is manufactured by the above-described manufacturing method, and the mold is further processed. As the mold, an inverted mold may be produced by electroforming or resin molding. Electroforming and resin molding in this case can be carried out by conventional methods.

When a large number of molds having the same shape as the mold obtained by the above-described manufacturing method are duplicated, electroforming or resin molding may be performed by a conventional method.

The mold obtained by the manufacturing method of the present invention can be used in a pressing method, a 2P method, a casting method, etc., whereby even a flat plate-shaped molded product having fine-pitch grooves can be dimensioned. It is possible to mold with high accuracy.

[0020]

According to the method of manufacturing a die of the present invention, when forming a groove in the die, a metal layer to be cut which is a die is formed on a roll, and the metal layer to be cut is cut using a lathe. Since cutting is performed while rotating as in the case of processing, it is possible to form grooves in the die with high dimensional accuracy. Particularly, even when linear grooves are formed at a fine pitch in the mold, the grooves can be formed with high dimensional accuracy and in a short time.

Further, according to the present invention, after the metal layer to be cut is machined, the metal layer to be cut is removed from the roll to form a flat plate, so that the obtained mold is a usual pressing method, 2P method, casting method or the like. It becomes a flat mold that can be used in. Therefore,
By using this mold, it is possible to obtain a molded product having a desired groove shape with high accuracy by a pressing method, a 2P method, a casting method, or the like.

[0022]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 A lenticular lens 31 formed on the opposite lens surface of the Fresnel lens 30 shown in FIG.
As shown in (b), a lenticular lens 31 (having a radius of curvature of 0.2 m) composed of a large number of cylindrical lenses.
m, pitch 0.08 mm) was produced as follows.

That is, an iron roll (diameter 400 mm) was plated with 2 mm of copper as a roll protective layer. This copper layer is N
After surface finishing with a C lathe and immersion degreasing in a 4 wt% sodium hydroxide aqueous solution, AC electrolysis is performed in a 10 wt% sodium hydroxide aqueous solution to form a copper oxide film, and then
Copper was 0.8 mm plated as the metal layer to be cut.

This was mounted on a cutting device as shown in FIG. 2 and rotated, and first, a surface-finishing tool was attached to a tool rest to surface-finish the metal layer to be cut, and its thickness was made uniform.
Next, a cutting tool was attached to the tool rest, and a mold for forming the lenticular lens shown in FIG. 3B was cut on the surface of the metal layer to be cut.

After the cutting process, the metal layer to be cut was cut open using an air sander, removed from the roll and flattened to obtain a flat plate-shaped mold.

Using the plate-shaped mold thus obtained, polymethylmethacrylate resin was added at a temperature of 160 ° C. and a pressure of 100 Kg.
When pressed at f / cm ² , a lenticular lens with desired accuracy could be formed.

Example 2 In order to enhance the strength of the cutting surface of the flat die manufactured in Example 1, nickel was plated to a thickness of 0.3 μm on the cutting surface.

A lenticular lens was molded in the same manner as in Example 1 using the plate-shaped mold thus obtained. As a result, a lenticular lens with desired accuracy could be obtained.

Example 3 A reverse mold of the flat plate-shaped mold manufactured in Example 1 was manufactured as follows by electroforming. That is, first, the flat plate-shaped mold produced in Example 1 was immersed in a dichromate 5 g / l aqueous solution for 10 seconds, and this was nickel-plated (thickness: 2.5 mm) in a sulfamic acid bath. In this case, the sulfamic acid bath composition is 400 g / l nickel sulfamate, 15 g / l nickel chloride, 30 g / l boric acid, and 0.5 g / surfactant.
It was set to l. Also, bath temperature 45 ° C, pH 4, current density 2A /
dm ² . Next, surface finish by milling,
The flat metal mold prepared in Example 1 was released to prepare a nickel electroforming mold. The obtained nickel electroforming mold also had the desired dimensional accuracy.

Example 4 A nickel mold having the same shape as the flat plate mold prepared in Example 1 was reproduced as follows.

That is, first, an acrylic resin plate (thickness: 3 mm) heated to 180 ° C. in the flat plate mold manufactured in Example 1
Was cold-pressed and released to prepare a resin mold.

Next, a nickel mold similar to the flat plate mold manufactured in Example 1 was duplicated by electroforming using this resin mold as a master mold. The nickel plating conditions during electroforming were the same as in Example 3, and the nickel thickness was 2.5 mm.
Then, the surface was finished by milling, heated to 60 ° C. and released from the resin mold to prepare a nickel electroforming mold. Further, the copper on the surface was removed by dipping it in a hydrogen peroxide solution. The nickel die thus obtained also had the desired dimensional accuracy, like the flat die produced in Example 1.

[0034]

According to the present invention, it is possible to easily obtain a die for producing a flat plate-shaped molded product having fine pitch linear grooves with high dimensional accuracy and in a short cutting time. .

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a mold manufacturing method of the present invention.

FIG. 2 is a schematic perspective view of a cutting device used for cutting the mold of the present invention.

FIG. 3 is a perspective view of the combination lens of the Fresnel lens and the lenticular lens (FIG. 3A) and a front view of the lenticular lens (FIG. 3B).

[Explanation of symbols]

 1 roll 1a roll shaft 5 peeling layer 6 protective layer 10 metal layer to be cut

Front Page Continuation (72) Inventor Takao Kibushi 2-28 Kurashiki-cho, Nakajo-cho, Kitakanbara-gun, Niigata Prefecture Kuraray Co., Ltd.

Claims (4)

[Claims] 1. A metal layer to be cut is formed on a roll, the metal layer to be cut is cut while rotating the metal layer to be cut around the axis of the roll as a rotation center, and then the metal layer to be cut is removed from the roll. A method for producing a plate-shaped molded product die, which comprises removing and forming a flat plate shape. 2. The method for producing a mold for a flat-shaped molded article according to claim 1, wherein the metal layer to be cut is formed on the roll with a release layer interposed therebetween. 3. The flat plate according to claim 1, wherein after cutting, the metal layer to be cut is made into a flat plate shape, and then a metal layer harder than the metal to be cut is formed on the cut surface of the metal layer to be cut. For manufacturing a die for a molded article. 4. A flat molded article for producing a mold by the method according to any one of claims 1 to 3, and using the mold as a mother die to produce an inverted mold by electroforming or resin molding. Mold manufacturing method.