JP3608351B2 - Embossing roll mold and its manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an embossing roll mold used for press molding, and more particularly to an embossing roll mold having high mold surface hardness and excellent chemical resistance, and a method for producing the same.
[0002]
[Prior art]
Examples of molded products using an embossing roll mold include prism sheets, lenticular sheets, and Fresnel sheets used for LCD backlights, rear projection screens, and the like.
Conventionally, as a method of molding these lens sheets, copper plating is performed on an iron core, and an embossing roll mold is created by cutting this plating layer with a diamond bite, and the following molding method has been taken. .
[0003]
(1) At the time of melt extrusion molding using an extruder, the resin surface extruded in a molten state is embossed using an emboss roll die.
(2) Applying ultraviolet ray or electron beam curable resin to the molding surface of the embossing roll mold, supplying a transparent base material to the embossing roll mold, and irradiating with ultraviolet rays or ionizing radiation through the transparent base material The resin is cured, and at the same time, the resin molding is polymerized and bonded to the transparent substrate.
Etc. (Hereinafter, these moldings are collectively referred to as “press molding”)
[0004]
When lens sheets as optical parts are molded by the above press molding, the reproducibility of the shape of the molded product and the durability of the mold greatly affect the optical characteristics and the cost of the product. Therefore, there is a need for an embossing roll mold that can reproduce a stable shape without deformation or corrosion of the embossing roll mold by repeated press molding over a long period of time.
[0005]
Conventionally, when an embossing roll mold is put to practical use, plating such as chromium or nickel has been applied to the molding surface for the following reasons.
(B) Poor durability (mechanical strength) during press molding.
(B) The surface is easily oxidized and the smoothness (glossiness) of the molding surface is likely to be lowered.
[0006]
Therefore, by applying chromium plating with a thickness of about 2 to 4 μm to the molding surface, the hardness can be improved (Vickers hardness about 400) and the durability can be improved, but there are still the following drawbacks.
(A) Since leveling (thickness uniformity of the plating layer) is poor and the shape of the molding surface is strictly different from the shape after cutting, the objective is when the molded product is a lens sheet. The optical characteristics cannot be accurately reflected.
(B) The chromium plating layer has micro cracks on the surface, and deteriorates the optical characteristics of the surface of the molded product.
[0007]
When nickel plating (electrolytic nickel plating) is applied instead of chromium plating, the smoothness of the molding surface is good, but on the other hand, the hardness decreases (Vickers hardness of about 300) and the durability decreases. However, the above-mentioned drawback (a) still remains.
[0008]
In order to improve the surface resistance of the embossing roll mold for the reason described above, JP-A-8-133306 is known as a proposal by the present applicant,
The embossing roll metal mold | die of the structure by which the nickel plating layer, the copper plating layer, and the TiN layer are formed in this order on the cylinder roll surface is proposed.
[0009]
The above proposal aims to improve the durability by improving the smoothness of the molding surface of the embossing roll mold and increasing the hardness of the plating surface. When the layer was provided, there was a problem that rust was easily generated.
[0010]
[Problems to be solved by the invention]
The present invention solves the above-mentioned drawbacks of the prior art, and is a molded product obtained not only by mechanical durability but also by chemical embossing that does not generate rust and smoothness of the molding surface. The present invention provides an embossing roll mold capable of well reproducing the surface shape of the mold and a method for producing the same.
[0011]
[Means for Solving the Problems]
The above problem can be solved by the following means.
That is, the present invention is characterized by being an embossing roll mold having a structure in which a copper plating layer, a nickel plating layer, and a TiN layer are formed in this order on the surface of a cylinder roll.
The embossing roll mold manufacturing method includes forming a copper plating layer on the surface of the cylinder roll, forming a pattern on the surface by cutting, providing a nickel plating layer, and further forming ion plating on the surface. A TiN layer is formed by a method.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, as shown in FIG. 3, a cylinder (32) having a diameter of 250 mm and a surface length of 800 mm is ground by grinding, washed with water, activated with dilute sulfuric acid, and then a copper plating layer (31) is formed on the surface. did. The thickness of the plating layer is preferably in the range of 500 to 700 μm. The copper sulfate plating bath used was one having a composition of 200 to 250 g / L of copper sulfate, 80 to 100 g / L of sulfuric acid, an appropriate amount of brightener, and a plating temperature of 30 to 35 ° C.
[0013]
After finishing the copper plating, the plating layer thickness varies, so in order to obtain a uniform plating thickness, set it on a dedicated lathe and adjust the surface roughness to 3 μm or less using a carbide tool. Further, the base was cut using a diamond tool so that the surface roughness was 1 μm or less.
[0014]
Next, a groove having a desired shape was cut by cutting the copper plating layer using a diamond tool (33).
[0015]
Remove the embossing roll from the dedicated lathe, perform alkaline degreasing (40 degrees Celsius) for 15 minutes or more, rinse with water, immerse in dilute hydrochloric acid for 3 to 5 minutes, rinse again with water, and electrolytic degreasing (room temperature) at 2 to 6 After performing for a minute and washing with water, an electrolytic nickel plating layer was formed. The thickness of the plating layer is preferably in the range of 1 to 2 μm. After plating, it was washed with water and hot water and dried. The nickel plating bath used was a composition of nickel sulfamate 300-450 g / L, boric acid 30-40 g / L, nickel chloride 10-20 g / L, brightener appropriate amount, pH 4.0-4.5. The nickel plating layer may be electrolytic nickel plating or electroless nickel plating, and any plating method can be selected as appropriate.
[0016]
Next, after the embossing roll was immersed in an organic solvent solution, the embossing roll was pulled up and completely blown off the solvent on the roll surface using a nitrogen gun so that no liquid residue remained. The solvent may be any of toluene, xylene, acetone and the like. Subsequently, a TiN film was formed by ion plating on the degreased roll surface. As shown in FIG. 4, the embossing roll (40) subjected to the degreasing treatment is heated to 200 to 400 ° C. in advance, and then a voltage of 60 to 80 V is applied to the embossing roll to make it negative. Charge. On the other hand, the entire TiN processing chamber (50) is charged positively by applying a voltage. At this time, plasma-like titanium is generated from the titanium target (51) disposed in the chamber, and TiN charged positively with the nitrogen gas introduced at a flow rate of about 100 sccm into the TiN processing chamber (50) becomes negative. An embossing roll having a TiN film formed on the surface thereof is obtained by being attracted to the charged embossing roll (40).
[0017]
Thus, the embossing roll metal mold | die (20) of the structure by which the copper plating layer, the nickel plating layer, and the TiN layer were formed in this order on the cylinder surface was obtained.
[0018]
【The invention's effect】
As described above, according to the present invention, the surface hardness is high, the smoothness and mechanical durability of the molding surface are good, and the nickel plating is provided in the lower layer of the TiN layer, so that the generation of rust is complete. Therefore, it is possible to provide an embossing roll mold having excellent chemical durability.
Therefore, in press molding using the embossing roll mold of the present invention, when molding lens sheets as optical parts, excellent reproducibility of the shape of the molded product, so good optical performance as optical parts A product having is obtained. In addition, since the mold has excellent durability, the embossing roll mold is not deformed or corroded even in the long-term repeated press molding. The mold life is long, and as a result, the cost of the product can be reduced.
[0019]
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a cross section of a conventional embossing roll mold.
FIG. 2 is an explanatory view showing a cross section of an embossing roll mold according to the present invention.
FIG. 3 is an explanatory view showing a manufacturing process of an embossing roll mold.
FIG. 4 is an explanatory diagram showing TiN treatment by ion plating.
[Explanation of symbols]
10, 20 ... Embossing roll molds 13, 24, 32 ... Cylinders 12, 23, 31 ... Copper plating layers 11, 21 ... TiN layer 22 ... Nickel plating layer 40 ... Embossing roll 50 ... TiN treatment Chamber 51 ... Ti target 52 ... Nitrogen gas inlet 53 ... Exhaust port

Claims (5)

The embossing roll metal mold | die of the structure by which the copper plating layer, the nickel plating layer, and the TiN layer are formed in this order on the cylinder roll surface. The embossing roll metal mold | die of Claim 1 in which the pattern which consists of a groove shape by cutting is formed in the copper plating layer surface. The embossing roll mold according to claim 2, wherein the pattern is any one of a V-shaped groove shape, a U-shaped groove shape, a spherical groove shape, and an aspherical groove shape. The embossing roll metal mold | die in any one of Claims 1 thru | or 3 of the structure by which the nickel plating layer and the TiN layer are formed in this order on the said pattern surface. (1) forming a copper plating layer on the cylinder roll surface;
(2) a step of forming a pattern on the surface of the copper plating layer by cutting by a threading method using a cutting tool having a predetermined shape;
(3) forming a nickel plating layer on the pattern surface by a method of either electrolytic nickel plating or electroless nickel plating;
(4) A method for producing an embossing roll mold comprising the step of forming a TiN layer on the surface of the nickel plating layer by an ion plating method.

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