JP2502954B2 - Manufacturing method of electroforming mold - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention is vacuum forming of plastic relates <br/> a porous electroformed mold manufacturing how to use the blow molding or the like, in particular, with the position of the hole can be easily secured For those with high productivity.

[0002]

2. Description of the Related Art First, the structure of a porous electroforming mold of this type and an example of its use will be described with reference to FIG. In FIG. 3, this porous electroforming mold 31 has a large number of through holes 31a, and a grain pattern or the like is formed in a vacuum forming machine 35 in which a vacuum pump 32, a heater 33, and a clamp 34 are arranged. It is equipped with the molding surface 31b facing upward. In the case where the porous electroformed mold 31 is used to vacuum-mold a door trim skin, a crash pad skin, etc. of an automobile interior part,
First, the sheet material 36 is heated and softened by the heater 33, and the sheet material 36 is clamped above the molding die 31.
Fix at 4. Then, by operating the vacuum pump 32, the sheet material 36 and the molding die 31 are passed through the through hole 31a.
The air between the sheet material 36 and the molding die 31 is vacuumed. Then, the sheet material 36 is attracted to the molding die 31 to bring the sheet material 36 into close contact with the molding surface 31 b of the molding die 31, and the sheet material 36 is molded into the same shape as the molding die 31.

By the way, in order to obtain a dense reversibility such as a textured pattern, it is desirable that a large number of small holes 31a of the molding die 31 are opened, and the size thereof is 0.1.
Although it is preferable that the hole diameter is about mm, it is not realistic to form such a small vent hole 31a by machining or electric discharge machining. Therefore, conventionally, a porous molding die has been manufactured by utilizing electroforming as described below.

That is, in the production of a forming die by electroforming, a conductive layer is provided on the surface of an electroformed model, and a metal layer is deposited on this conductive layer by electrolytic plating to form an electroforming die. In the method of manufacturing a porous electroforming mold, when a large number of non-conductive parts are provided in this conductive layer, a metal layer does not precipitate in this non-conductive part. A casting mold is obtained. A specific example of a method for manufacturing such a porous electroforming mold will be described with reference to FIG. 2 (see Japanese Patent Publication No. 2-14434). In FIG. 2, an electroformed model 21 having the same shape as that of the molded product was manufactured, and 30% was added to the surface 21a of the electroformed model 21 in which a paste silver lacquer and butyl acetate were mixed at a ratio of 1: 1. The conductive layer 22 is formed by spraying a spray liquid containing a vinyl chloride lacquer liquid in the following proportions. Then, the vinyl chloride lacquer is scattered on the conductive layer 22 to form minute non-conductive portions 23, and the conductivity of the conductive layer 22 as a whole is lowered, and the electroformed material does not easily deposit on the non-conductive portions 23. Therefore, a minute non-electrodeposition portion 25a is generated. The non-electrodeposited portion 25a grows in the through hole 25 as the electroforming proceeds.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The method of manufacturing a porous electroforming mold described in the prior art is a method in which a non-conductive material, vinyl chloride lacquer, is mixed in a solution form into a spray liquid for forming a conductive layer. As a result, the non-conductive part formed by solidification is dispersed and formed in the conductive layer, which causes the following problems. That is, since the conductivity of the formed conductive layer is lowered as a whole, a current having a high current density has to be passed, and thus electroforming distortion is likely to occur. Further, the size of the formed non-conductive portion is not uniform, and therefore the size of the through hole formed from the non-conductive portion is not uniform. Furthermore, it is difficult to position the non-conductive portion at a desired portion of the electroformed model.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is to make it possible to easily secure the positions of the through holes and to easily manufacture the porous holes. An object of the present invention is to provide a method for manufacturing a sex electroforming mold.

[0007]

In order to solve the above-mentioned problems, in the method of manufacturing an electroforming mold according to the present invention, a conductive layer containing a large number of expandable plastic microspheres by a predetermined treatment is formed on the surface of a model. And a second step in which the plastic microspheres are expanded by a predetermined treatment to break the conductive layer existing on the surface of the spheres, and the model is electroformed to form an electroformed shell. And a fourth step of removing the plastic micro hollow spheres in the electroformed shell with a solvent or the like to obtain a porous electroformed shell.

[0008]

[0009]

According to the above-mentioned structure, after the conductive layer containing a large number of expandable plastic microspheres is formed on the surface of the electroformed model, the plastic microspheres are expanded by a predetermined process and the conductive layer existing on the surface of the spherical body is expanded. The non-conductive portion is formed by rupturing. Then, when this electroformed model is subjected to electroforming treatment, a metal layer is not deposited on the non-conductive portion, and a porous electroformed shell is obtained.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a process diagram showing a method for manufacturing an electroforming mold of the present invention.

In FIG. 1, as shown in FIG.
On the surface of the electroformed model 1 made of epoxy resin or the like, a large number of plastic micro hollow spheres 3 are spray-coated or brush coated with a solution of a plastic micro hollow sphere 3 which expands by heating, a silver paste and a solvent. The conductive layer 2 including is formed. The plastic micro hollow sphere 3
Is a diameter φ5 made of vinylidene chloride or the like in this embodiment.
A hollow sphere having a size of μ to φ40 μ and a gas enclosed in the interior 3a was used. The conductive layer 2 has a thickness of about 5 μm. The plastic micro hollow sphere 3 may be expanded by a vacuum treatment or a chemical action. Further, the inside may be solid depending on the expansion method.

Next, this electroformed model was steam-heated to about 100 ° C. to 150 ° C. in an oven (not shown), and
As shown in (b), the plastic micro hollow spheres 3 contained in the conductive layer 2 are expanded about 4 times in diameter and about 60 times in volume. As a result, the plastic micro hollow sphere 3
The conductive layer 2a existing on the surface of the is broken, and the surface of the plastic micro hollow sphere 3 becomes a non-conductive portion.

Next, this electroformed model is electroplated in an electrolytic plating bath (not shown) by connecting the electroformed model to the negative electrode and the copper or nickel material for plating to the positive electrode.
As shown in FIG. 1C, the metal layer 4 is deposited on the conductive layer 2 to a predetermined thickness to form an electroformed shell. However, at this time, no metal is deposited on the surface of the plastic micro hollow sphere 3 which is the non-conductive portion, and the electroformed shell becomes porous. After that, the plastic micro hollow spheres 3 are eluted with a solvent or the like to form through holes, and a porous electroforming mold is obtained.

In the above-described method of manufacturing the electroforming mold, since the non-conductive portion is the plastic sphere 3, the position of the non-conductive portion on the electroformed model 1, that is, the position of the through hole formed thereon can be easily adjusted. Can be identified and secured. In addition, since the plastic micro hollow sphere 3 which is a non-conductive material is separated from the conductive material in the solid state, the conductivity of the conductive layer 2 as a whole does not decrease, and therefore the current density can be suppressed from increasing, and the electroformed shell can be suppressed. Since the internal stress of can be stopped to the minimum,
There is almost no distortion. Further, since the plastic micro hollow spheres 3 can be mixed with a conductive material in advance and used as a spray liquid or the like, a method similar to the conventional method may be used to form the conductive layer, and no special labor is required. Then, in order to form the non-conductive portion, it suffices to expand the plastic micro hollow spheres 3 by heating or the like, which is easier than, for example, the case of forming the non-conductive portion by corrosion. Therefore, the productivity of the electroforming mold is good.

[0015]

As described above, the method of manufacturing an electroforming mold of the present invention comprises forming a conductive layer containing a large number of expandable plastic microspheres on a surface of an electroformed model by a predetermined treatment.
The plastic microsphere is expanded by a predetermined treatment to rupture the conductive layer present on the surface of the sphere, and thereafter,
This electroformed model is electroformed to form a porous electroformed shell. Therefore, a through hole is formed at the position of the plastic microsphere, and the position of the through hole of the electroforming mold can be easily secured. Further, since the plastic microspheres, which are non-conductive materials, are separated from the conductive material in the solid state, the conductivity of the entire conductive layer does not decrease so much, and the distortion of the electroformed shell is extremely small. Furthermore, the conductive layer may be formed by the same method as the conventional method, and the non-conductive portion may be formed by expanding the plastic microspheres by a predetermined process, so that the productivity of the electroforming mold is good.

[Brief description of drawings]

FIG. 1 is a process drawing showing a method for manufacturing an electroforming mold of the present invention.

FIG. 2 is a diagram showing a conventional method for manufacturing an electroforming mold.

FIG. 3 is a diagram showing a method of using the electroforming mold.

[Explanation of symbols]

1 Electroformed model (model) 2 Conductive layer 2a Conductive layer existing on the surface of plastic micro hollow sphere 3 Plastic micro hollow sphere 4 Metal layer (electroformed shell)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Zhouichi Yokoyama Ninya, Kobe, Hyogo Prefecture Water wheel Shinta character Miyasaka 111-1

Claims (1)

(57) [Claims] 1. A first step of forming a conductive layer containing a large number of plastic microspheres expandable by a predetermined treatment on the surface of a model, and the plastic microspheres are expanded by a predetermined treatment and are present on the surface of the spherical body. The second step of rupturing the conductive layer, the third step of electroforming this model to form an electroformed shell, and the step of removing plastic microspheres in the electroformed shell with a solvent or the like to form a porous layer. 4th of obtaining electroformed shell
The manufacturing method of the electroforming mold characterized by including the process of.