JPS60264213A - Manufacture of molded article having uneven surface - Google Patents

Abstract

PURPOSE:To manufacture high-quality molded article efficiently, by a method wherein a transfer foil possessing a peel ply, an opacifying ply and an adhesive bond on the upper surface of a holding material in this order and possessing a protuberant printed layer on the back is held on the inner wall surface of the inside of a mold, and thermoplastic resin is injected from an adhesive bond side of the transfer foil. CONSTITUTION:A transfer foil 8 having a peel ply 4, opacifying ply 6 and an adhesive bond 7 in this order on the upper surface of a holding material 1 possessing heat resistance and possessing a protuberant printed layer 2 on the back is held on a smooth inner wall surface of a mold so that a side of the adhesive bond is faced toward an injection side and a side of the protuberant printed layer is confronted with a core wall surface, and molded article to the surface of which the transfer foil 8 is stuck, that is, the peel ply 4, opacifying ply 6 and the adhesive bond 7 are transferred through heat and pressure at the time of molding is obtained by injecting thermoplastic resin 11 softened through heating from the adhesive bond 7 side of the transfer foil. As the transference is performed simultaneously with injection molding by holding the transfer foil having the protuberant printed layer on the back of the holding material within an injection molding die like this, an uneven molded article superior in performance can be produced efficiently without having a matter that a hollow part is inferior in adhesion properties to the molded article.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing thermoplastic resin molded articles, and in particular, to efficiently manufacture molded articles having patterns, etc. that match or harmonize with the precisely uneven surface. That is.

[Conventional technology]

A conventional method for producing molded products with a concave-convex pattern is to engrave a concave-convex pattern on the inner wall of the mold in advance, but this method only increases the cost of the mold. However, it was not easy to match or harmonize the uneven patterns obtained in this way with the designs applied later. Another method is to use a transfer foil with a raised printing layer and transfer it to a normal molded product with a smooth surface by heating and pressing with a transfer rubber roll, but this method does not apply enough transfer pressure to the recessed parts. There was a practical problem in that the degree of adhesion of the ink layer in the recessed portions to the transfer surface was insufficient, resulting in peeling and falling over time.

[Problem that the invention seeks to solve]

The present invention is intended to solve the above-mentioned problems, and provides a method for efficiently manufacturing a high-quality molded product having layers of solid transferred patterns that are synchronized or harmonized with a finely uneven surface. It is.

(Means for Solving the Problems) The method for manufacturing a high-quality molded product having an uneven surface according to the present invention will be described in detail below with reference to the drawings.

That is, a heat-resistant support (1
) A transfer foil (8) having at least a release layer (4), a concealing layer (6) and an adhesive layer (7) in this order on the upper surface and a raised printing layer (2) on the back surface, with the adhesive layer side The transfer foil is held so that it faces the index side and the raised print layer side faces the core wall surface, and heat-softened thermoplastic resin (11) is injected from the side of the transfer foil adhesive layer (7) to apply the transfer foil ( After obtaining a molded product in which the attached release layer (4), concealing layer (6), adhesive layer (7), etc. of 8) were transferred by heat and pressure during molding, the adhesion to the surface of the molded product was then completed. The transfer foil support (1) and the raised print layer (2) are peeled off and removed as one body to obtain a thermoplastic resin molded product having a recessed portion on the surface corresponding to the raised ink portion of the raised print layer. This is a method for manufacturing a molded product having an uneven surface, and if necessary, a raised printing layer (2) on the back side is used as a transfer foil between the release layer (4) and the concealing layer (6), and a pattern layer that is in tune or harmonious with the pattern. (5) This is a method for manufacturing a molded article having an uneven surface.

If we describe the transfer foil (8) that is characteristic of the present invention, it consists of a raised printing layer (2), a support (1),
Release layer (3), release layer (4), pattern layer (5), hiding layer (
6) and adhesive layer (7), and this raised printing layer provided on the back side of the support contains a large amount of inorganic extender pigment using thermosetting resin (melamine resin, urethane resin, etc.) as a binder. It consists of a build-up ink with a high solid content, and when applied on a support, it exhibits sufficient adhesion to the support, and is suitable for gravure printing,
Dry ink film thickness 2 to 50μ by screen printing method etc.
The support is made of thermoplastic polyethylene terephthalate having a thickness of about 12 to 38 μm. It is made of a heat-resistant material such as (PET) film, and a release layer is applied to the surface of the support as necessary, and is in close contact with the support to improve releasability with the release layer. It is omitted if the release layer and the release layer exhibit good releasability to each other as is.The release layer not only has releasability to the support or mold release layer, but also has a layer that improves the surface properties of the molded product. The pattern layer is often transparent, and the pattern layer may or may not be aligned with the raised print layer on the back side, and this may be omitted in the case of plain color. Also, the hiding layer is an opaque ink layer applied on top of the pattern layer, and is used to hide unevenness, streaks, etc. in the molding resin.Finally, speaking of the adhesive layer, this layer covers the entire transfer layer to the molding resin. It has the role of adhesion, and may penetrate part or all of the transfer layer to achieve its purpose.

Next, regarding the molding process, the transfer foil is sandwiched between the cavity (9) and the core (10) so that the adhesive layer side faces the injection side and the raised printing layer side faces the core wall surface. All you have to do is inject the heat-softened thermoplastic resin from the side. At this time, the transfer foil may be sandwiched between the cavity (9) and the core (10), or it may be cut out in advance and placed in the mold. After the injection is completed,
When the molded product is cooled and taken out from the mold, the transfer layer is completely transferred to the surface of the molded product due to the strong heat pressure during injection, resulting in a molded product with four parts corresponding to the raised printed parts on the back side. At this time, the transfer layer (15) consisting of a release layer, a pattern layer, a concealing layer, and an adhesive layer is extremely firmly adhered to the surface of the molded article.

When the support of the transfer foil, the mold release layer, and the raised print layer are peeled off and removed as one body, a molded product is obtained that reflects the surface conditions of the support and the mold release layer.

[Effect]

In the present invention, since the transfer foil having the above-mentioned structure is used, when the heat-softened thermoplastic resin is injected from the side of the transfer foil adhesive layer, the transfer foil attached to the surface, that is, the peeling layer, the hiding layer, and the adhesive layer, are removed during molding. A molded product can be obtained by applying heat and pressure to the molded product, and when the support of the transfer foil and the embossed printing layer attached to the surface of the molded product are peeled off and removed as a whole, the embossed ink portion of the embossed printing layer appears on the surface. It is possible to efficiently obtain a thermoplastic resin molded product having a recess corresponding to the shape of the molded article.

〔Example〕

・Example 1 On the surface of a PET film with a thickness of 25 μm, a release layer having releasability to the PET film and mainly composed of acrylic resin, for example, was printed, and on top of that, a grain pattern ink layer,
A concealing solid ink layer and an adhesive ink layer are sequentially formed, and then a grain pattern is created on the back side of this PET film using a gravure plate with a depth of 90μ, and a build-up ink containing polyester resin, melamine resin, and extender pigment as the main components is applied. A transfer foil was obtained by printing using the gravure printing method. The thickness of this raised printed layer after drying was about 10 microns. While holding this transfer foil inside a mold with a smooth inner surface so that the adhesive layer side faces the injection side and the raised printing layer side faces the core wall surface, heat-softened polystyrene resin is applied from the adhesive ink layer side. A molded product was obtained by injection. When the support of the transfer foil and the raised ink layer adhering to the surface were removed together, a molded article with a sandy pattern on the surface was obtained.

The surface transfer layer adhered extremely firmly to the molded article, and there was no problem with the adhesion of the recessed portions.

・Example 2 A melamine resin-based release layer was provided on the entire surface of a 38μ thick PET film by gravure printing, and after baking and drying, an acrylic resin-based release layer was provided on it,
Furthermore, a concealing layer and an adhesive layer are sequentially provided, and then a cloth grain pattern is created on the back side of this PET film using a screen printing ink with a solid content of approximately 70%, the main components of which are melamine resin and extender pigments. Transfer foil was obtained by printing an abstract pattern. The thickness of this raised printed layer after drying was about 30 microns. When injection molding was performed using this transfer foil in the same manner as in Example 1, a plain colored molded product with large irregularities on the surface was obtained. In this example, since the mold release layer was provided on the entire surface, the mold release property was extremely good.

[Effects] The present invention relates to a method for forming a finely uneven surface and simultaneously imparting a solid pattern that matches or harmonizes with the surface, by holding a transfer foil having a raised printing layer on the back side of a support in an injection mold. Because the transfer is performed at the same time as injection molding, it is extremely efficient to produce concave-convex molded products with superior performance patterns, without the drawback of inferior adhesion of the concave parts to the molded product, compared to the conventional post-transfer method. It is possible.

[Brief explanation of the drawing]

Fig. 1 shows a cross-sectional explanatory diagram of one embodiment of the transfer foil used in the present invention, and Fig. 2 shows a process explanatory diagram when manufacturing a molded article based on the present invention. Yes, 3rd
The figure shows an explanatory cross-sectional view of a molded article obtained by the method of the present invention. 1... Support 2... Embossed printing layer 3... Release layer 4... Peeling layer 5... Pattern layer 6... Hiding layer 7... Adhesive layer 8... Transfer foil 9... Capity 10... Core 11... Thermoplastic resin 12... Concave portion 13... Convex portion 14... Molded product 15... Transfer layer

Claims (1)

[Claims] 1. A transfer foil having at least a release layer, a concealing layer, and an adhesive layer in this order on the upper surface of a heat-resistant support, and a raised printing layer on the back surface, on the smooth inner wall surface of the mold. A molded product in which a thermoplastic resin that has been softened by heat is injected from the side of the transfer foil adhesive layer, and the transfer foil is attached to the surface, that is, the release layer, hiding layer, adhesive layer, etc. are transferred by heat and pressure during molding. After that, the transfer foil support and the raised print layer attached to the surface of the molded article are peeled off and removed as a whole, thereby producing a thermoplastic resin having recesses corresponding to the raised ink portions of the raised print layer on the surface. Method for producing a molded product with an uneven surface, characterized by obtaining a molded product 2 Patent for using a transfer foil with a pattern layer that matches or harmonizes with the raised printing layer on the back side between the release layer and the concealing layer A method for manufacturing a molded product having an uneven surface according to claim 1.