JPH0542927B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a resin molded product having an uneven pattern on its surface, such as a texture pattern, a wood grain pattern, a satin pattern, a leaf vein pattern, a scale pattern, a marble pattern, etc. This invention relates to a method for molding an uneven pattern onto a resin molding mold used for manufacturing.

More specifically, a pattern forming layer that defines the planar position of a predetermined uneven pattern to be formed on the processed surface is formed on the processed surface, and recesses are formed on the processed surface through the pattern forming layer. The depth of the recess can be varied depending on the removal position due to dissolution or swelling of the pattern-forming layer, the removal time, and the difference in processing time caused by the difference in the passage time of the etching liquid to the pattern-forming layer. The present invention relates to a method for forming an uneven pattern by etching, sandblasting, etc., which enables the formation of uneven patterns.

[Conventional technology]

In the above-mentioned uneven pattern forming method, conventionally, the uneven surface of the pattern forming layer is formed simultaneously with the formation of the pattern forming layer by applying a viscous pattern forming layer constituent agent with a brush or a brush. (For example, see Japanese Patent Publication No. 51-20178).

[Problem to be solved by the invention]

However, the conventional method described above has the following problems.

First, the formation of the uneven surface on the surface of the pattern forming layer, which is carried out simultaneously with the formation of the pattern forming layer, is carried out by means of coating, which is a repeated operation, which is time-consuming and has poor working efficiency.

Moreover, since the uneven surface is applied manually by means of coating, it is difficult to faithfully reproduce uneven patterns that exist in nature, such as wood grain patterns and leaf vein patterns, on the uneven surface.

In view of the above-mentioned circumstances, an object of the present invention is to provide a method for forming a concavo-convex pattern with good workability and high reproducibility of a concavo-convex surface.

[Means to solve the problem]

In order to achieve the above object, in the method for forming an uneven pattern on a mold surface according to the present invention, a predetermined planar position of a predetermined uneven pattern to be formed on the processed surface that constitutes the mold surface for molding is provided. A pattern-forming layer is provided to define the pattern-forming layer, and the layer thickness of this pattern-forming layer is made to correspond to the depth of the recesses of the uneven pattern to be formed on the workpiece surface, so that the shallower the recesses, the greater the layer thickness changes. The present invention is characterized in that an uneven surface is formed on the surface of the pattern forming layer by molding so as to cause depressions and depressions to be formed on the surface to be processed through the pattern forming layer.

[Effect]

The effects of the above configuration are as follows.

That is, in the case of the present invention, for example, a pattern-forming layer constituting agent is placed on the workpiece surface to a predetermined thickness, and a master on which an uneven surface has been formed in advance is pressed onto the pattern-forming layer constituting agent. It is possible to form uneven surfaces of various depths in the pattern forming layer all at once.

In addition, when creating the above-mentioned master that will serve as the mold for molding, this master can be used by pressing uncured master material onto the surface of the actual tree skin or leaf and making a mold. It becomes possible to make the uneven surface of the pattern-forming layer formed by this process faithfully reproduce the above-mentioned actual pattern.

〔Effect of the invention〕

As a result, the uneven surface of the pattern forming layer can be created all at once by molding, which improves workability.
By making the mold for molding from the actual pattern, we have created an excellent method for forming a concave-convex pattern that enables faithful reproduction of the pattern.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

The method for forming an uneven pattern according to the present invention is particularly applicable to the mold surface of a resin molding die used for producing a resin molded product having various uneven patterns such as a wood grain pattern, a leaf vein pattern, or a satin finish pattern on its surface. A method suitable for forming such a structure, for example, a method using etching processing, which is one example thereof, consists of the following steps.

<> Pattern forming layer 2 on the processed surface 1 of metal etc.
A process of forming the surface 2a into a concavo-convex surface corresponding to the concavo-convex surface to be formed on the surface to be processed 1 (the state at the end of this process is shown in FIG. 1A).

Note that the word "corresponding" mentioned above refers to the case where the uneven surface of the pattern forming layer 2 is formed exactly the same as the uneven surface of the processed surface 1, and the reproduction of the uneven surface during processing as described later. This also includes cases where it is formed in anticipation of deterioration.

<> After a predetermined period of time has elapsed after forming the pattern forming layer 2, depending on the material of the surface to be processed 1, for example,
A step in which a corrosive solution such as ferric chloride for copper and nitric acid for zinc is made to flow over the entire surface of the pattern forming layer 2 (see FIG. 1B).

In this step, the etching liquid uniformly dissolves the surface of the pattern forming layer 2. As a result, the skin of the surface to be processed 1 is sequentially exposed from the thin layer portion of the pattern forming layer 2, and this exposed skin portion is corroded by the corrosive liquid to form a recess. Then, as the surface of the surface to be processed 1 is exposed, the dissolution gradually spreads to the thicker portion of the pattern forming layer 2, and the exposed portion of the surface of the surface to be processed 1 becomes larger. At this time,
Corrosion progresses in the bare surface of the processed surface 1, which is exposed for the first time, and the recesses become deeper.

Therefore, when the pattern-forming layer 2 is completely dissolved, an uneven surface is formed on the surface 1 to be processed, with the etching depth changing from deeper in the thinner portions of the pattern-forming layer 2 to shallower in the thicker portions. (See Figure 1, c).

The above-mentioned step <>, that is, the formation of the pattern forming layer 2 is performed by molding. Next, some of the methods are listed.

<a> As shown in FIG. 2A, a pattern forming layer constituent material 2' is applied to a predetermined thickness on the surface 1 to be processed, and when this pattern forming layer constituent material 2' is in a deformable state, it becomes a mold. By pressing the master 3 onto the pattern forming layer constituent material 2' and using heating or other means as necessary, the master 3 is applied to the surface of the material 2'.
A method of forming a pattern forming layer 2 having an uneven surface in which the uneven surface is reversed, and fixing this pattern forming layer 2 to the processed surface 1.

<b> As shown in FIG. does not need to be smoothed),
The pattern-forming layer constituent material 2' is fixed to the workpiece surface 1 by pressing the master against the workpiece surface 1 while the pattern-forming layer constituent material 2' is unsolidified, and using heating or other means as necessary. A method of forming the pattern forming layer 2 by

<c> As shown in Figure 2 C, the above <b
> Similarly, the pattern forming layer constituent material 2' is placed on the surface of the master 3, the surface is smoothed and solidified, the solidified pattern forming layer constituent material 2' is peeled off from the master 3, and then the adhesive is applied. A method of forming the pattern forming layer 2 by adhering it to the surface to be processed.

The master 3 used in the methods <a> to <c> described above may be made of a hard material such as synthetic resin or metal, or a flexible material such as resin.

The latter flexible master 3 is roughly divided into [1] those that deform elastically and [2] those that deform plastically. Rubbers such as rubber, styrene-butadiene rubber and nitrile rubber, [1-2] Elastomers such as polyurethane, [1-3] Flexible resins such as vinyl chloride, and [2] those that undergo plastic deformation include: , [2-1] In the process of complete reaction or complete polymerization, [2-2] In the state in which completely reacted or completely polymerized parts coexist with unreacted or unpolymerized parts. .

In addition, as specific examples of the above [2-1], [2-1-1] polyester resin, filler, thickener,
A compound mixed with an appropriate colorant and curing agent, or a mold release agent, thickened at 40 to 50℃ for one day, [2-1-2] Ethyl silicate, colloidal silica, silicate [2-1-3] Gypsum is mixed with water, a setting rate regulator, an accelerator (magnesium oxide, etc.), a slowing agent (carbonate, etc.) There is a paste-like plaster material that has been adjusted with (soda, etc.).

Further, as a specific example of [2-2], there is one in which an epoxy resin and a filler are mixed with a curing agent in an amount smaller than the appropriate curing ratio.

When using a flexible master 3, even if the processed surface 1 has a complex shape such as a three-dimensional curved surface, it can be made to conform to the complex shape by deforming it such as elongation or contraction. .

Further, the master 3 described above can be manufactured by various methods, but in particular, when the master is manufactured using a material that hardens by means such as heating or pressure, it is possible to manufacture the master 3 using a material that hardens by means such as heating or pressure. Alternatively, by pressing the material against the surface of an actually existing object such as natural stone and making a mold, the uneven surface of the pattern forming layer 2 obtained from the master 3 can be made to be faithful to the actual uneven pattern. Similarly, the uneven surface of the processed surface after corrosion processing can be reproduced faithfully to the actual uneven pattern.

Pattern forming layer 2 obtained in the above step <>
The pattern-forming layer constituting material 2' is, for example, [a] Mixed flour or asphalt powder and precipitated calcium carbonate in a predetermined ratio, added a certain amount of water and stirred, and then bonded with vinyl acetate resin. [b] Various resins such as thermosetting resins, thermoplastic resins, and ultraviolet curing resins; [c] Various types of resins. Metals, [d] Various ceramics, [e] Natural polymers such as gum arabic, glue, or polypeptite, semi-synthetic polymers such as dextrin and carboxymethyl cellulose, synthetic polymers such as polyvinyl alcohol and polyacrylic acid, etc. Water-soluble resin or water-absorbing resin (as a base material or binder), [f] 2 or 3 of the above [b] to [e]
[g] Mixture of resin, metal, or ceramic particles, fibers, or whiskers with soluble or insoluble resin such as epoxy, urethane, acrylic, polyester, PVC, or water glass. Dispersed in a binder consisting of, etc.

No matter which of the pattern forming layer constituent materials 2' described in [a] to [g] above is employed, the pattern forming layer constituent material 2' must be etched at approximately the same etching speed as the surface to be processed 1. Alternatively, it is desirable to configure the etching process to be performed at a slightly slower speed.

By mixing powder and granules into the etching liquid used in the above-mentioned step <> and spraying this etching liquid in the etching direction, the directionality of etching by this etching liquid is enhanced, and the etching process surface 1 is improved after etching. It is also preferable to prevent the uneven surface from becoming rougher than the uneven surface of the surface of the pattern forming layer 2. In addition, in the pattern forming layer 2, powder grains, small pieces, etc. soluble in the corrosive liquid,
For the same reason, it is also preferable to improve the directionality of etching by including fibers or the like with orientation in the etching direction.

In addition, in anticipation of the deterioration in reproduction of the uneven surface described above due to isotropic etching, after forming an uneven surface on the surface of the pattern forming layer 2, the edges are etched to make the unevenness of the uneven surface stand out. It is also preferable to perform processing. Furthermore, an uneven surface may be formed in the master 3 by performing correction in advance to account for deterioration in reproduction of the uneven surface.

Pattern-forming layer constituent material 2' forming the pattern-forming layer 2
In addition to being removed by being dissolved by a corrosive solution as described above, it may also be removed by crushing or swelling. In addition, the pattern forming layer 2 is formed from a pattern forming layer constituent material 2' having permeability to the etching liquid, and the etching on the surface 1 to be processed is achieved by the difference in passage time of the etching liquid depending on the thickness of the pattern forming layer 2. It may be possible to make the depths different.

Furthermore, the uneven surface forming method according to the present invention includes methods such as sandblasting, polishing, etc., in addition to the above-mentioned etching process.
It can be applied to methods of forming an uneven surface by various processing.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the method for forming an uneven pattern on a mold surface according to the present invention, and FIG. 1A to C are cross-sectional views showing the steps, and FIGS. It is. 1... Processed surface, 2... Pattern forming layer.

Claims (1)

[Scope of Claims] 1. A method for forming an uneven pattern on a mold surface, in which a pattern on a processed surface 1 constituting a mold surface for molding is formed by unevenness provided on the surface of the processed surface 1. , a pattern forming layer 2 is provided on the processed surface 1 for defining the planar position of a predetermined uneven pattern formed on the processed surface 1, and the layer thickness of this pattern forming layer 2 is set according to the thickness of the pattern forming layer 2. Machining surface 1
Corresponding to the depth of the concave part of the uneven pattern to be formed,
A mold surface that forms an uneven surface by molding on the surface of the pattern forming layer 2 so that the shallower the recess is, the greater the change in layer thickness, and forming the recess on the processed surface 1 through the pattern forming layer 2. A method for forming a concavo-convex pattern. 2. The method for forming an uneven pattern on a mold surface according to claim 1, wherein the formation of the recesses is performed by etching.