JPH06287790A - Production of porous electroform body - Google Patents

Abstract

PURPOSE:To surely form fine porous through-holes in production of a perforated metallic mold to be used at the time of executing vacuum forming, etc., of for example, a resin product. CONSTITUTION:Crystal nuclei P consisting of fine powder of copper are stuck on the surface of a model M. This model M is immersed into an electroless plating liquid A contg. copper sulfate, by which copper ions are precipitated on the crystal nuclei P and are epitaxilly grown and an acicular epitaxy crystal Q is formed. The surface of this model M is provided with an electrical conductivity by subjecting the surface of a silver mirror treatment and thereafter, nickel Ni of the thickness within the length of the crystal Q is electrodeposited on the part exclusive of the crystal Q part by electroforming of nickel, by which an electroforming shell K is formed. This electroforming shell K is immersed in a ferric oxide soln. C to elute the crystal Q. The eluting parts are constituted as the through-holes h.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for producing a porous mold used for vacuum forming resin products.

[0002]

2. Description of the Related Art Conventionally, a pattern such as a leather grain pattern may be transferred to a resin product such as an instrument panel which is an automobile interior part. A method of vacuum forming using a mold is known. In order to manufacture such a mold by electroforming, a technique such as Japanese Patent Publication No. 2-14434 is known. In this case, a paste-like silver lacquer is formed on the surface of a model made of a non-conductive member. It sprays a mixed solution of vinyl chloride lacquer and vinyl chloride lacquer to form a conductive layer with minute non-conductive parts on the model surface. Then, electroforming is performed on the surface of this model to generate a non-electrodeposition part in the non-conductive part, and this non-electrodeposition part is grown to form a large number of through holes.

[0003]

However, in the case of the above technique, even if a non-electro-deposited portion is initially generated in the non-conductive portion, the non-electro-deposited portion may be crushed and the hole may be closed as the electroforming grows. However, there is a problem that it is difficult to control the formation of through holes. In addition, there are some places where non-conductive parts are generated, and there is also a drawback that the generation rate of through holes is not constant depending on the part of the mold.

[0004]

In order to solve such a problem, the present invention attaches a large number of crystal nuclei on the surface of a model, and after epitaxially growing the same kind of element on the crystal nuclei to form an epitaxy crystal, The surface of this model was subjected to electroconductivity treatment and electroforming treatment. Then, a metal having a thickness within the length of the crystal is electrodeposited on a portion other than the crystal part to form an electroformed shell, and the crystal is removed from the electroformed shell to form a large number of fine through holes in the electroformed shell. I did it.

[0005]

Function: The through hole is formed by using the epitaxy crystal whose crystal axes are aligned in one direction. That is, around the epitaxy crystal grown in the shape of a needle, to form an electroformed shell by electrodepositing a metal having a thickness within the length of the crystal, and then removing the epitaxy crystal to form a through hole, The through hole is surely formed without being crushed. Moreover, the hole diameter of the through hole can be freely controlled by the size of the crystal nucleus, and moreover, the crystal nucleus is surely attached to an arbitrary place by the adhesive,
The position of the through hole can be easily controlled.

[0006]

EXAMPLE An example of the method for producing a porous electroformed product of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a flow chart of the manufacturing process of the porous electroformed body of the present invention, and FIG. 2 is an explanatory view of the growth of crystal nuclei and the subsequent process.

[0007] For example, when forming a leather grain pattern on the surface of an instrument panel component of an automobile, there is known a method of vacuum forming using a die having a large number of through holes.

At this time, for example, a sheet-like skin which has been softened by heating is sucked from a large number of through holes of the mold and closely adhered to the mold, and when the through holes are large, a sheet material having good transferability is obtained. In this case, since the holes are transferred together and the surface becomes rough, it is necessary to prevent the holes from being transferred by forming as fine through holes as possible.

Therefore, the method for producing a porous electroformed body of the present invention is intended to surely form fine through holes that do not affect the appearance surface of the product, and grow the needle-like column shape. The through holes are formed using the epitaxy crystal.

As shown in FIG. 1A, at the first stage of the manufacturing process of the present invention, a thin adhesive S is applied to the surface of the washed model M (mandrel). And this adhesive S is for planting the crystal nucleus P described below.

Further, the model M is made of a non-conductive material such as epoxy resin and has an inverted shape obtained by inverting the actual mold.

Next, the crystal nucleus P is sprayed and planted on the model M coated with the adhesive S as shown in (b). The crystal nucleus P has a particle size of 10 μm to several 1
It is a fine powder that becomes the core of an epitaxy crystal of 00 μm, and in the examples, copper, which is a fine metal powder other than nickel, is used because the electroforming process is nickel electroforming as described later. Of course, this crystal nucleus P is made of, for example, Si, Ge, Ga,
It may be a fine powder such as SiC or Sn.

Next, the model M in which the crystal nuclei P are planted is (c)
As shown in (3), it is immersed in the electroless plating solution A, and copper ions are reduced and precipitated centering on the crystal nucleus P to grow crystals.

In the case of the embodiment, this electroless plating solution A contains copper sulfate as a metal salt, formaldehyde as a reducing agent, sodium hydroxide as a PH adjusting agent, and an alkanolamine complexing agent as a complexing agent. It consists of agents and other stabilizers.

That is, when the model M is dipped in the electroless plating solution A, the copper ions reduced and precipitated on the surface of the crystal nucleus P of the copper powder shown in FIG. Then, as shown in (2) of the same figure, it grows as an epitaxy crystal Q.

Next, as shown in FIG. 1D, the surface of the model M on which the epitaxy crystal Q is formed is subjected to a silver mirror treatment to impart conductivity. That is, for example, a plating bath G made of a mixed solution of a silver salt and a reducing agent is spray-coated on the surface of the model M to form a silver coating on the surface.

Then, the model M subjected to this silver mirror treatment is shown in FIG.
Nickel electroforming is performed by immersing in electrolytic solution B as shown in (e). That is, the electrolytic solution B is, for example, a nickel sulfamate bath that is said to be capable of high-speed processing and has a small internal stress. When the normal electroforming process is performed with the model M side as the cathode, FIG. As shown, nickel Ni is electrodeposited so as to wrap around the epitaxy crystal Q to form an electroformed shell K.

Further, as shown in the same figure, the thickness of the electroformed shell K is made shorter than the length of the epitaxy crystal Q so that the tip of the needle-shaped epitaxy crystal Q projects from the surface of the electroformed shell K. There is.

Next, when the electroformed shell K is demolded as shown in FIG. 1F, the electroformed shell K composed of an integral body of the epitaxy crystal Q and nickel Ni is removed from the model M.

Therefore, in order to remove the epitaxial crystal Q from the electroformed shell K, the electroformed shell K is immersed in the crystal solution C as shown in FIG. And such a crystal solution C
If the epitaxy crystal Q is copper as in the example, it is, for example, a ferric chloride solution, and by immersing it in this solution, only the fine epitaxy crystal Q is eluted, and as shown in FIG. The eluted portion becomes a porous through hole h.

When a large number of minute through holes h are formed in this way, as shown in FIG. 1C, a mold D and a breathable backup E are attached to form a vacuum forming mold. In such a mold, since the hole diameter of the through hole h can be controlled by the grain size of the crystal nucleus P, the product can be molded without the trace of the through hole h being transferred to the product.

Further, since the position where the crystal nuclei P are planted is surely made by the adhesive S, the position where the through hole h is formed can be surely and easily selected.

[0023]

As described above, according to the method for producing a porous electroformed product of the present invention, an epitaxy crystal is grown in the shape of a needle, an electroformed shell is formed around the crystal part, and then the crystal is removed. Since the holes are used, it is possible to surely form fine porous through holes. Moreover, since the hole diameter and position of this through hole can be freely controlled, it is easy to prevent the influence of the porous hole from appearing in the product.

[Brief description of drawings]

FIG. 1 is a flow chart of a manufacturing process of a porous electroformed body of the present invention.

FIG. 2 is an explanatory diagram illustrating the growth of crystal nuclei and the subsequent steps.

[Explanation of symbols]

 K Electroformed shell M Model P Crystal nucleus Q Epitaxy crystal h Through hole

Claims (1)

[Claims] 1. A step of depositing a large number of crystal nuclei on the surface of a model, a step of epitaxially growing an element of the same kind on the crystal nuclei to form an epitaxy crystal, and a step of conducting a conductive treatment on the surface of the model. , A step of electroforming a model subjected to a conductive treatment to form an electroformed shell by electrodepositing a metal having a thickness within the length of the crystal in a portion excluding a crystal part, and the crystal from the electroformed shell A method for producing a porous electroformed body, which comprises a step of removing and forming a large number of fine through holes in an electroformed shell.