JPH0140737B2 - - Google Patents

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.

[Prior art] A conventional method for producing molded products with a concave-convex pattern is a method in which the concave-convex pattern is carved on the inner wall of the mold in advance, but this method requires high mold costs. Not only did this result in a rough pattern, but it was also difficult to match or harmonize the uneven pattern obtained in this way with the designs applied later. Also,
There is also a method of using a transfer foil with a raised printing layer and transferring it to a regular molded product with a smooth surface by heating and pressing using a transfer rubber roll, etc. However, with this method, the transfer pressure on the recessed parts is insufficient, so the recessed parts are There was a practical problem in that the degree of adhesion of the ink layer 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 problems]

The method for producing 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 transfer foil 8 comprising at least a raised printing layer 2, a peeling layer 4, a concealing layer 6, and an adhesive layer 7 provided in this order on a heat-resistant support 1 having a smooth inner wall surface of the mold is placed on the back surface of the support. The transfer foil is held so as to face the wall surface of the core, and heat-softened thermoplastic resin 11 is injected from the side of the transfer foil adhesive layer, and the transfer layer 15 is attached to the surface, that is, the release layer 4, the concealing layer 6, the adhesive layer 7, etc. After obtaining a molded product 14 which has been transferred by heat and pressure during molding, the support 1 of the transfer foil and the raised print layer 2 attached to the surface of the molded product are then peeled off and removed as one body, thereby creating a raised surface on the surface. Concave portion 1 corresponding to the raised ink portion of printing layer 2
2 is a method for producing a molded article having an uneven surface, which is characterized by obtaining a thermoplastic resin molded article having an uneven surface, and if necessary, a support 1 and an embossed printing layer are provided on or below the embossed printing layer 2 as a transfer foil. 2 and a mold release layer 3 with good adhesion is used, and if necessary, a pattern layer 5 that is in tune with or harmonizes with the pattern of the raised printing layer 2 is used as a transfer foil between the release layer 4 and the concealing layer 6. This is a method of manufacturing a molded article having an uneven surface using a molded article.

If we describe the transfer foil 8 that is characteristic of the present invention, it consists of the following layers: the support 1, the raised print layer 2, the release layer 3, the peeling layer 4, the pattern layer 5, the hiding layer 6, and the adhesive layer 7. This support is made of a heat-resistant material such as a polyethylene terephthalate (PET) film with a thickness of about 12 to 38 μm, and the raised printing layer is made of a thermosetting resin (melamine resin, urethane resin, etc.) as a binder. It consists of a build-up ink with a high solid content containing a large amount of inorganic extender pigment, and when applied on a support, it shows sufficient adhesion to the support and can be dried by gravure printing, screen printing, etc. The ink film is applied to a thickness of approximately 2 to 50μ, and is characterized by being less deformed by heat and pressure during molding.A mold release layer is also applied to the surface of the support as necessary. This is to improve the releasability of the support and the release layer that is applied on top of it (it is omitted if the support and release layer exhibit good releasability with each other as they are). ), In addition, when a mold release layer is applied to the support and then a raised printing layer is provided on it, the concavities and convexities of the final molded product can be improved by providing a difference in gloss between the mold release layer and the raised printing layer. The difference in gloss can be easily adjusted, and it may or may not be reflected in the pattern of the raised printing layer, and this is often omitted in the case of plain colors. In addition, the release layer not only has releasability to the support or mold release layer, but also has transparency in many cases because it improves the surface properties of the molded product. may or may not be aligned with the raised printing layer, and is omitted in the case of a plain color.Also, the concealing layer is an opaque ink layer applied on the pattern layer, and it prevents unevenness of the molding resin. , to hide streaks, etc. Finally, speaking of the adhesive layer, it has the role of adhering the entire transfer layer to the molding resin, and it penetrates into part or all of the transfer layer. Sometimes it serves its purpose.

In the present invention, a support, a release layer, or a raised printing layer, and a release layer applied thereon are laminated together by heating and pressure, and then peeled from each other to effectively change the surface condition of the peeled surface at that time. Make use of it.

Next, regarding the molding process, place the transfer foil into the cavity 9 with the adhesive layer side facing the injection side.
It is only necessary to insert the heated and softened thermoplastic resin between the core 10 and the cavity side and inject the heated and softened thermoplastic resin from the cavity 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 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 recesses in the areas corresponding to the raised printed areas. can get. 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 release layer, and the raised print layer are peeled off and removed as one unit, a molded product is obtained in which the convex portions have the same gloss as the release layer and the recesses have the same gloss as the raised print layer.

[Effect]

In the present invention, in order to use the transfer foil having the above-mentioned configuration,
When the heat-softened thermoplastic resin is injected from the side of the transfer foil adhesive layer, it is possible to obtain a molded product with the transfer foil attached to the surface, that is, the release layer, hiding layer, and adhesive layer are transferred by the heat and pressure during molding. Then, by peeling and removing the transfer foil support and the embossed printing layer attached to the surface of the molded product, a thermoplastic resin molded product having a recess corresponding to the embossed ink portion of the embossed printing layer on the surface can be efficiently produced. It is possible to obtain the desired results.

〔Example〕

Example 1 A grain pattern was printed on the surface of a PET film with a thickness of 25 μm using a gravure plate with a depth of 90 μm using a build-up ink containing polyester resin, melamine resin, and extender pigment as main components. The thickness of this raised printed layer after drying was about 10 μm.

Next, a release layer made of acrylic resin, which has release properties for both the PET film and the raised print layer, is printed, and then a grain pattern ink layer, a concealing solid ink layer, and an adhesive ink layer are sequentially formed on top of that. A transfer foil was obtained. While this transfer foil was held inside a mold with a smooth inner surface so that the back surface of the support faced the core wall surface, heat-softened polystyrene resin was injected from the adhesive ink layer side to obtain a molded product. When the support of the transfer foil and the raised ink layer adhering to the surface were removed together, a molded article with a grain pattern having a grain pattern on the surface was obtained. The surface transfer layer adhered extremely firmly to the molded article, and there were no problems with the adhesion of the recesses.

Example 2 After providing a release layer consisting of a melamine resin and a matting agent on the surface of a 25μ thick PET film for the purpose of releasing properties and adjusting gloss, each layer was applied thereon in the same order as in Example 1. A transfer foil was obtained. In this example, a matting agent was used to give the release layer a semi-glossy gloss and the raised print layer a matte gloss. While holding this transfer foil inside an injection mold with a smooth inner surface so that the back surface of the support faces the core wall surface, heat-softened acrylonitrile-butadiene-styrene copolymer (ABS resin) is injected from the adhesive layer side. A molded product was obtained. When the support of the transfer foil attached to the surface was peeled and removed together with the release layer and the raised printing layer, a molded article with unevenness on the surface was obtained.

The concave portions of the molded product were matte, and the convex portions were semi-glossy, and were completely in sync with each other, giving it an extremely high design quality.

Example 3 A cloth-grain abstract pattern was printed on the surface of a 38 μm thick PET film by screen printing using a screen printing ink containing melamine resin and extender pigment as main components and having a solid content of approximately 70%. The thickness of this raised printed layer after drying was approximately 30 μm.

Next, a melamine resin-based release layer is applied over the entire surface by gravure printing, and after baking and drying, an acrylic resin-based release layer, a concealing layer,
A transfer foil was obtained by sequentially providing adhesive layers. When injection molding was carried out in the same manner using this transfer foil, 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.

〔effect〕

The present invention relates to a method of forming a finely textured surface and at the same time imparting a solid pattern that matches or harmonizes with the surface, a transfer foil having a raised printing layer is held in an injection mold and the transfer is performed simultaneously with the injection molding. Therefore, compared to the conventional post-transfer method, it is possible to extremely efficiently produce a concave-convex molded product with an excellent pattern, etc., without the disadvantage that the adhesion of the concave portion to the molded product is poor.

[Brief explanation of drawings]

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. 3 is a cross-sectional explanatory diagram of a molded article obtained by the method of the present invention. DESCRIPTION OF SYMBOLS 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...Cavity, 10...Core, 11...Thermoplastic resin, 1
2... Concave portion, 13... Convex portion, 14... Molded product, 1
5...Transfer layer.

Claims (1)

[Claims] 1. A transfer foil comprising at least a raised printing layer, a peeling layer, a concealing layer, and an adhesive layer provided in this order on a heat-resistant support is held on a smooth inner wall surface of a mold, and the transfer foil is After injecting heat-softened thermoplastic resin from the side of the foil adhesive layer to obtain a molded product with the transfer foil attached to the surface, that is, the peeling layer, hiding layer, and adhesive layer have been transferred by heat and pressure during molding. By peeling and removing the transfer foil support and the embossed printing layer that have adhered to the surface of the molded product, a thermoplastic resin molded product having a recessed portion corresponding to the embossed ink portion of the embossed printing layer on the surface can be obtained. A method for manufacturing a molded product having a characteristic uneven surface. 2. A molded product having an uneven surface according to claim 1, which uses a transfer foil having a support and a release layer that has good adhesion to the raised print layer on or below the raised print layer. Production method. 3. A method for manufacturing a molded article having an uneven surface according to claim 1, which uses a transfer foil having a pattern layer that is synchronized or harmonized with the raised printing layer between the release layer and the concealing layer.