JPH07156197A - Production of insert sheet to be preformed and insert moldings - Google Patents

Abstract

PURPOSE:To obtain an insert molding having a high surface hardness by a method wherein a substrate sheet is made of a laminate of a high-hardness resin layer and a low-hardness resin layer, and at least a pattern layer is laminated on the low-hardness resin layer of the substrate. CONSTITUTION:An insert sheet 1 to be preformed and a pair of injection molds 4 forming a cavity 40 are prepared. By closing the molds 4, a molding of a required shape can be obtained. The insert sheet 1 is heated and preformed along the surface shape of the required molding. The insert sheet 1 is set in the injection molds 4. After the injection molds 4 are closed, a molten resin 5 is injected into the cavity 40. The insert sheet 1 is set in the injection molds 4 so that the molten resin 5 can be injected on the pattern layer side of the insert sheet 1. Lastly, the injection molds 4 are opened after the molten resin is cooled and set, and an insert molding having a surface covered with the insert sheet 1 is removed from the injection molds 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preform insert sheet formed on the surface of a molded product used for a front panel of an AV device, an instrument panel of an automobile, various buttons and the like, and a method for manufacturing an insert molded product.

[0002]

2. Description of the Related Art Conventionally, a preform insert sheet in which at least a picture layer is formed of ink and a cavity capable of obtaining a molded article having a desired shape by closing a mold are formed on a base sheet. Using a pair of injection molding dies, first, the insert sheet is heated and preformed so as to follow the surface shape of the desired molded product, and the insert sheet is injected so that the molten resin is injected into the pattern layer side of the insert sheet. Installed in the injection mold,
There is a so-called insert molding method in which the injection molding die is closed, the molten resin is injected into the cavity, the molten resin is cooled and solidified, and then the insert molded article is taken out from the injection molding die.

As a conventional insert sheet for preform used in this insert method, there is one in which a picture layer and an adhesive layer are formed by printing ink on a base sheet made of a low hardness resin such as acrylic rubber.

[0004]

The substrate sheet is made of a resin having a low hardness because it needs to be flexible because it is wound up on a roll and used. However, a base sheet made of a low hardness resin is soft and easily scratched. Therefore, the insert-molded product obtained by insert-molding using the insert sheet using such a base material sheet also has low surface hardness and is easily scratched, and does not have durability of the decorative effect of the product. there were.

It is also conceivable to use a high hardness resin having a hardness that does not easily scratch, for example, a methylmethacrylate resin as the base sheet of the insert sheet. However, in order to mold the resin into a sheet or film, that is, in a state of several μm to several hundreds of μm in thickness,
This is done by slowly pulling the resin that has been softened by heating, but a high-hardness resin with a pencil hardness of 2H or higher has high hardness and almost no flexibility, so it cannot absorb the pulling force and is broken. Therefore, it is impossible to use the high hardness resin as a base material sheet of the insert sheet, and it is impossible to use the high hardness resin for the base material sheet of the insert sheet.

An object of the present invention is to provide a preform insert sheet for obtaining an insert-molded product having a high surface hardness and a method for manufacturing the insert-molded product.

[0007]

In order to achieve the above object, the insert sheet for preform of the present invention comprises:
An insert sheet preheated to fit the surface shape of the desired molded product is mounted in the injection mold,
A preform used in the insert molding method in which the molten resin is injected into the cavity formed by closing the injection mold, the molten resin is cooled and solidified, and then the insert molded product is taken out from the injection mold. The insert sheet for use has a structure in which at least a pattern layer is laminated on the low hardness resin layer of the base material sheet which is a laminate of the high hardness resin layer and the low hardness resin layer.

The method for producing an insert-molded article of the present invention is also the insert sheet for a preform of the present invention, and a pair of injections forming a cavity capable of obtaining a molded article of a desired shape by closing the mold. Using the molding die, first, the insert sheet is heated and preformed so as to follow the surface shape of the desired molded product, and the insert sheet is injection-molded so that the molten resin is injected into the pattern layer side of the insert sheet. It is mounted inside, the injection mold is closed, the molten resin is injected into the cavity, and after the molten resin is cooled and solidified, the insert molded product is taken out from the injection mold.

Further, in the method of manufacturing the insert-molded article of the present invention, the heating preform may be constructed so as to be carried out in an injection molding die.

The present invention will be described below in detail with reference to the drawings. The insert sheet 1 of the present invention uses a laminate of a high hardness resin layer 10 and a low hardness resin layer 11 as a base sheet, and a pattern layer 12 and an adhesive layer 13 are sequentially formed on the low hardness resin layer 11. (See Figure 1). Picture layer 12
Is adhesive, the adhesive layer 13 is not necessary. The pattern layer 12 and the adhesive layer 13 are formed by a printing method or a coating method.

The high hardness resin layer 10 is made of a resin having a hardness that cannot be molded into a sheet or a film. The high-hardness resin layer 10 is formed by a co-extrusion method together with a low-hardness resin layer 11 described later, using a resin having a pencil hardness of H or higher, such as methylmethacrylate resin. Specifically, at the same time when the low hardness resin layer 11 is formed into a film or sheet, the high hardness resin layer 10 may be formed into a film or sheet on the surface of the low hardness resin layer 11.

The low-hardness resin layer 11 is easily formed into a sheet or a film. The low-hardness resin includes polycarbonate resin, acrylic rubber, styrene resin, vinyl chloride resin, polyethylene resin, polypropylene resin, nylon resin, ABS resin and the like, and generally has a pencil hardness of about HB or less.

Next, a method of manufacturing the insert molded product will be described.

First, the above-mentioned insert sheet 1 for preform and a pair of injection molding dies 4 for forming a cavity 40 by which a mold having a desired shape can be obtained by closing the dies are prepared (see FIG. 2).

The injection mold 4 may be one in which minute irregularities 41 are formed on the surface forming the cavity 40. The minute concavities and convexities 41 are irregularities represented by a grain formed on the surface of the injection molding die by engraving or the like.

Then, the insert sheet 1 for preform is heated and preformed so as to follow the desired surface shape of the molded product. For heating preforming, a heating press molding apparatus using a press die including a core mold having a convex portion and a cavity mold having a concave portion to be fitted with the convex portion, a heating vacuum forming device, a heating pressure air forming It is advisable to use a heating preform means for molding a normal resin sheet into a desired three-dimensional shape, such as an apparatus. The concave portion of the cavity mold is an injection mold 4 for injection molding a desired molded product described later.
The inner surface shape is exactly the same as the concave portion. Insert sheet 1
The shape of the preform is such that it closely fits the inner surface shape of the recess of the injection molding die described later. The heating temperature is
Depending on the material of the base sheet of the insert sheet 1, 15
0 to 180 ° C is suitable. The heating preform may be performed in the injection mold 4.

Next, if necessary, unnecessary portions are cut and removed. In order to cut and remove unnecessary portions of the insert sheet 1, a press cutting device having a knife or a cutting blade, a sliding cutting die for cutting with a peripheral edge of a convex portion of one die and a peripheral edge of a concave portion of the other die. A normal resin sheet cutting means such as a mold, a heating cutting device, or a laser cutting device may be used.

Either the heating preform or the cutting removal of the insert sheet 1 may be performed first. Alternatively, by using a preform press die with a cutting blade, it is possible to carry out simultaneously.

Next, the insert sheet 1 is mounted in the injection molding die 4 (see FIG. 3), the injection molding die 4 is closed, and the molten resin 5 is injected into the cavity 40 (see FIG. 4). . Molten resin 5 on the pattern layer 13 side of the insert sheet 1
The insert sheet 1 is mounted in the injection molding die 4 so that is injected.

The molten resin 5 includes acrylonitrile styrene resin, acrylonitrile butadiene styrene resin, polycarbonate resin, polystyrene resin, acrylic resin, polyester resin and the like.

When the injection molding die 4 having minute irregularities 41 is used, if the height difference of the irregularities of the minute irregularities 41 of the injection molding die 4 is small, only the high hardness resin layer 10 is injected into the injection molding die 4. It is thermally deformed along the minute irregularities 41. If the height difference of the unevenness of the minute unevenness 41 is large, the high hardness resin layer 10 and the low hardness resin layer 11 are thermally deformed along the minute unevenness 41 of the injection molding die 4.

Finally, after the molten resin is cooled and solidified, the injection molding die 4 is opened, and the insert molded article whose surface is covered with the insert sheet 1 is injected into the injection molding die 4.
Take out more (see FIG. 5).

[0023]

In the insert sheet for a preform of the present invention, the high hardness resin layer covers the low hardness resin layer, so that the insert molded article obtained has a high surface hardness.
Since the insert sheet for preform of the present invention is a base material sheet in which a low hardness resin layer and a high hardness resin layer are laminated, a high hardness resin can be used as the base material sheet.

[0024]

[Example] A base material obtained by laminating a methyl methacrylate resin film having a thickness of 50 μm and a pencil hardness of 2H as a high hardness resin layer and a polycarbonate resin film having a thickness of 100 μm and a pencil hardness of HB as a low hardness resin layer by a co-extrusion method. As a sheet, a pattern layer and an adhesive layer were formed on a polycarbonate resin film by silk screen printing to obtain an insert sheet for preform. This insert sheet for preform was heated and preformed while sucking at 150 to 180 ° C., then mounted on an injection molding die, and a molten resin composed of acrylonitrile styrene was injected to obtain an insert molded article. The obtained insert-molded product also had high surface hardness and strong scratch resistance.

[0025]

The insert sheet for preforms of the present invention has a high surface hardness, and the method for producing an insert-molded product using this insert sheet has a high surface hardness and is less likely to be scratched, and has a decorative effect on the product. A durable product is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an insert sheet for preform of the present invention.

FIG. 2 is a cross-sectional view showing a step in one embodiment of the method for manufacturing an insert-molded product of the present invention.

FIG. 3 is a cross-sectional view showing a step in one embodiment of the method for manufacturing an insert-molded product of the present invention.

FIG. 4 is a cross-sectional view showing a step in one embodiment of the method for manufacturing an insert-molded product of the present invention.

FIG. 5 is a cross-sectional view showing an insert-molded product obtained by the method for manufacturing an insert-molded product of the present invention.

[Explanation of symbols]

 1 Preform Insert Sheet 10 High-Hardness Resin Layer 11 Low-Hardness Resin Layer 12 Picture Layer 13 Adhesion Layer 4 Injection Mold 40 Cavity 41 Micro Asperity 5 Molten Resin 50 Molded Product

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[Procedure amendment]

[Submission date] June 14, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

The high hardness resin layer 10 is made of a resin having a hardness that cannot be molded into a sheet or a film. The high-hardness resin layer 10 is, for example, a methyl methacrylate resin.
Methacrylic acid such as fat and polymethylmethacrylate resin
Acrylic resin made of ester resin, or acrylic
Pencil hardness H such as acrylic resin made of acid ester resin
The resin is formed by coextrusion together with the low-hardness resin layer 11 described below. Specifically, at the same time when the low hardness resin layer 11 is formed into a film or sheet, the high hardness resin layer 10 may be formed into a film or sheet on the surface of the low hardness resin layer 11.

Claims (3)

[Claims] 1. An insert sheet, which has been preformed by heating so as to follow the surface shape of a desired molded article, is mounted in an injection molding die and melted in a cavity formed by closing the injection molding die. In the insert sheet for preform used in the insert molding method in which the resin is injected and the molten resin is cooled and solidified, the insert molded product is taken out of the injection mold, and a laminate of a high hardness resin layer and a low hardness resin layer An insert sheet for preform, characterized in that at least a picture layer is laminated on a low-hardness resin layer of a base sheet composed of a body. 2. A preform insert sheet according to claim 1, and a pair of injection molding dies that form a cavity by which a mold having a desired shape can be obtained by closing the dies. The insert sheet is heated and preformed so as to follow the surface shape of the desired molded product, and the insert sheet is mounted in the injection molding die so that the molten resin is injected into the picture layer side of the insert sheet, and the injection molding die Close the mold, inject the molten resin into the cavity,
A method for manufacturing an insert-molded product, which comprises removing the insert-molded product from an injection mold after cooling and solidifying the molten resin. 3. The method for producing an insert-molded article according to claim 2, wherein the heating preform is performed in an injection molding die.