JPH01141014A - Preparation of in-mold molded item having hairline surface - Google Patents

Abstract

PURPOSE:To make it possible to form easily an inmold molded item on which a hairline surface being hardly damaged is formed, by fixing a transfer material wherein a releasing layer, a picture design layer and an adhesive layer are successively formed on a surface of a base sheet on the rear face of which an uneven hairline pattern is formed, at a specified position in a mold and filling a resin for injection molding in the mold. CONSTITUTION:In-mold molding is carried out by using a transfer material 6 wherein an uneven hairline pattern to realize a hairline design is formed on the rear face of a base sheet 1. Pressure of an injection resin is thereby applied on the part where the hairline grooves of the base sheet 1 of the transfer material 6 are formed and the unevenness of the hairline shape formed on the rear face of the base sheet 1 appears on the surface side in such a way that the shape changes from V-shape to U-shape. When the transfer material 6 is thereby transferred, the projected part of the hairline surface formed has roundness oil its each apex and therefore has excellent scratch resistance.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for manufacturing an in-mold molded product having a hairline surface that is hard to be damaged.

[Conventional technology]

Conventionally, a transfer material is fixed in a predetermined position within an injection mold, the mold is closed, and resin is filled into the mold to form a molded product and at the same time the design of the transfer material is applied to the surface of the molded product. There is a so-called in-mold molding method. The transfer material used in the in-mold molding method is placed on the surface of the molded product. Therefore, the scratch resistance of the transfer surface is essential, and improving the scratch resistance, especially in hairline designs where scratches are easily noticeable, will lead to a marked improvement in the aesthetic appearance of the product. Conventionally, as a transfer material capable of expressing a hairline design, there has been a transfer material in which a release layer, a pattern layer, an adhesive layer, etc. are sequentially laminated on the surface of a base sheet on which hairline-shaped unevenness is formed. After forming and transferring a molded product with a hairline surface by in-mold molding using this transfer material, by peeling and removing the base sheet, a pattern opposite to the hairline-shaped unevenness of the base sheet is transferred to the release layer. As a result, hairline-shaped unevenness was formed on the surface of the release layer, that is, on the surface of the in-mold molded product.

[Problems to be solved by the invention]

In-mold molded products with conventional hairline surfaces are
It has a shape that is an inversion of the unevenness of the base sheet of the transfer material, and therefore has an acute-angled mountain shape like the teeth of a saw. As a result, the hairline design obtained did not have sufficient surface strength such as scratch resistance, and therefore the surface irregularities were crushed by scratches with nails, and the scratches were very conspicuous. In particular, because the convex part has an acute angle, it is extremely vulnerable to scratches in the direction perpendicular to the hairline.Normally, the release layer on the surface of the transfer material is mixed with polyethylene wax, Teflon powder, etc. Although the abrasion resistance was improved, scratches were still noticeable. In conventional technology, when a hairline design on the surface of an in-mold molded product is expressed by surface irregularities, as long as the convexities are acute angles, no matter how hard the transfer material is made of resin, its scratch resistance is However, there was a limit to this, and it was necessary to fundamentally change the shape of the unevenness that expresses the hairline. It is an object of the present invention to solve the above-mentioned problems and provide a method for easily forming an in-mold molded product having a scratch-resistant hairline surface.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured such that the protrusions of the hairline-shaped unevenness of the in-mold molded product are rounded. In other words, the method for manufacturing an in-mold molded product having a hairline surface according to the present invention involves sequentially forming a release layer, a pattern layer, and an adhesive layer on the surface of a base sheet on which hairline-shaped unevenness is formed on the back surface of the part where the hairline design is desired. The transferred transfer material is fixed in a predetermined position in the injection mold so that the adhesive layer side of the transfer material is in contact with the injection molding resin, the mold is closed, and the injection molding resin is placed inside the mold. It was designed to be filled with. The present invention will be explained in more detail with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of a transfer material used in the present invention. FIG. 2 is a sectional view showing an embodiment of the method for manufacturing an in-mold molded product having a hairline surface according to the present invention. 1 is a base sheet, 2 is a resin, 3 is a release layer, 4 is a pattern layer, 5 is an adhesive layer, 6 is a transfer material, 7 is a resin for injection molding, and 8 is a mold. First, the transfer material 6 (see FIG. 1) used in this invention will be explained. As the base sheet 1, one having hairline-shaped unevenness on its back surface is used. The unevenness may be provided when the hairline design is not provided, and may be provided on the entire surface or partially. Specifically, the unevenness may be formed on a plastic film such as polyethylene terephthalate, polypropylene, polyethylene, nylon, cellophane, or the like. It is preferable to use a material that has hairline-shaped irregularities formed on the back side of a material used as a base sheet for normal transfer materials, such as a composite film of paper and paper, by a physical processing method such as scratching the surface with sandpaper or nonwoven fabric. For example, in order to provide hairline-shaped unevenness on a desired part of the back surface of the base sheet 1, after forming hairline-shaped unevenness on the entire backside of the base sheet 1, the resin 2 is added to the part where the hairline design is not required, and the hairline design is applied. The resin 2 may be made of materials that have high adhesion to the base sheet 1, such as thermoplastic resins such as acrylic resins and vinyl resins, and thermoplastic resins such as urethane resins and epoxy resins. It is preferable to use a curable resin, an ultraviolet ray or electron beam curable resin such as methyl methacrylate, and the resin 2 may be formed by a normal printing method such as a gravure printing method or a screen printing method. The release layer 3 is provided entirely or partially on the surface of the base sheet 1 opposite to the surface having the unevenness, if necessary. After the transfer, the release layer 3 is peeled off from the base sheet 1, and an uneven pattern opposite to that of the base sheet 1 is formed on the surface of the release layer 3 corresponding to the unevenness of the base sheet 1. In addition, since it becomes the surface of the molded product that is the object to be transferred after the transfer, it also has the function of protecting each layer constituting the transfer material. The release layer 3 is formed by a normal printing method such as a roll coating method, a gravure printing method, or a screen printing method. As the release layer 3,
Thermoplastic resins such as acrylic resins and vinyl resins can also be used, but in order to fully demonstrate their function as a protective layer, thermosetting resins such as urethane resins and epoxy resins, ultraviolet or ultraviolet rays such as methyl methacrylate, etc. An electron beam curable resin may also be used. Further, in order to further improve the peelability, a peeling auxiliary layer made of thermoplastic resin, wax, silicone, or the like may be provided between the base sheet 1 and the peeling layer 3. The pattern layer 4 is formed by a conventional printing method using a colored ink made of a conventional pigment or dye, a binder, an additive, and the like. The pattern layer 4 may be a single layer or may have a multi-layer structure with multiple colors. Further, the pattern layer 4 may include a metal thin film layer of aluminum, nickel, or the like formed by a vacuum deposition method, a sputtering method, an ion blating method, or the like. Further, if necessary, a pre-anchor layer may be provided between the release layer 3 and the metal thin film layer to improve suitability for metal vapor deposition. Also, if necessary, between the metal thin film layer and the adhesive layer 5,
A rear anchor layer may be provided to increase the adhesion between the two. The adhesive layer 5 is for adhering each of the above layers to the object to be transferred. As the adhesive layer 5, a heat-sensitive or pressure-sensitive resin suitable for the surface material of the plastic molded product to be transferred is appropriately used. For example, if the material to be transferred is polystyrene, acrylic or vinyl chloride vinyl acetate resin may be used, and if the object is polypropylene, chlorinated polypropylene resin or ethylene vinyl acetate resin may be used. By configuring as described above, a transfer material 6 capable of forming a hairline design can be obtained. To carry out in-mold molding using the transfer material 6 described above, the transfer material 6 is first fixed at a predetermined position within the injection mold 8. The mold 8 to be fixed may be the fixed mold 8 or the movable mold 8. At this time, the adhesive layer side of the transfer material 6 is fixed so as to be in contact with the side of the injection molding resin 7, which will be described later. The transfer material 6 can be fixed using a film clamp 1flI provided in the mold 8, or by applying reduced pressure through a suction hole provided in the mold 8. It is advisable to adopt the method described below. Further, the transfer material 6 is preformed into the shape of a molded product, if necessary. Preforming methods include methods used in normal in-mold molding, such as vacuum suction into the mold 8, pressing with compressed air against the mold 8, and pressing against the mold 8 with pads, clamps, etc. It is recommended to adopt In addition, these methods may be used in combination, or the transfer material 6 may be heated and softened in advance before injection molding. In this case, it is an effective means for deforming the transfer material 6 into a desired shape, whether or not preforming is performed. Next, the mold 8 is closed, and the molten resin 7 for injection molding is injected into the cavity within the mold 8. (See FIG. 2) Examples of the resin 7 that can be used in the present invention include the following. For example, polysulfone, polyethersulfone, polyetherimide, polyimide, polyacrylic, polystyrene, acrylonitrile butadiene styrene copolymer, polyurethane, polyallyl ether, polyallylsulfone, polyolefin, polybutadiene,
Thermoplastic resins such as polypropylene, nylon, polycarbonate, polyacetal, fluororesin, polyester, polyphenylene sulfide, polyphenylene oxide, polybutylene terephthalate, polyethylene terephthalate, polyether ether kedone, or phenol, unsaturated polyester, epoxy, diallyl phthalate, polyimide It is a thermosetting resin such as. Note that fillers or additives such as glass fiber, talc, titanium oxide, etc. may be added to these resins as appropriate in order to adjust the properties of the material. By injecting the injection molding resin 7 into the mold 8 in this way, the transfer material 6 comes into close contact with the surface of the molded product, and then,
Cooling, opening of the mold 8, and removal of the molded product are performed, and the base sheet is peeled off to obtain an in-mold molded product having a hairline surface.

[Effect]

The method for manufacturing an in-mold molded product having a hairline surface according to the present invention includes a transfer material 6 having hairline-shaped unevenness on the back surface of a base sheet 1 to create a hairline design.
(See Fig. 1) is used for in-mold molding. Therefore, the pressure of the injection resin is applied to the portion of the base sheet 1 of the transfer material 6 where the hairline grooves are formed, and the hairline-shaped unevenness formed on the back side of the base sheet 1 changes its shape to the front side of the base sheet 1. It appears changing from a shape to a U shape (see Figure 2). Therefore, hairline unevenness in which the protrusions are rounded is formed on the release layer 3. Therefore, when this transfer material 6 is transferred, the convex portions formed on the hairline surface have rounded apexes, and have excellent scratch resistance.

【Example】

A 38 μm thick polyester film with a hairline finish on the back surface was coated with polyurethane resin by screen printing to partially fill the recesses. A release layer with a thickness of 2.0 μm was formed on the surface of this base sheet by gravure printing using an ink having composition 1 below, and then by gravure printing using an ink having composition 2 below. A pattern layer with a thickness of 1.0 μm was formed, and then an adhesive layer with a thickness of 2.0 μm was formed by gravure printing using an ink having composition 3 below to obtain a transfer material. Composition 1 (Parts by weight) Methyl methacrylate 30 Polyethylene wax 1.5 Toluene
68.5 Composition 2 Methyl methacrylate 15 Carbon black 20 Extender pigment
5 toluene
30 Methyl ethyl ketone 30 Composition 3 Methyl methacrylate 30 Carbon black 20 Toluene
30 methyl ethyl ketone
30 Next, this transfer material was fixed at a predetermined position within an injection mold. Next, the inside of the mold was pressurized to deform the transfer material until it almost came into contact with the mold surface. Next, after closing the mold, heated and molten ABS resin was injected under the following conditions, and after a predetermined cooling time, the mold was opened, the molded product was taken out, and the base sheet was peeled off. In this way, a beautiful in-mold molded product with a partial hairline design formed on the surface was obtained. The resulting hairline transfer pattern had a hairline-shaped unevenness that was not easily crushed and had excellent abrasion resistance. Injection conditions (using JC150SA made by Japan Steel Works)・Mold temperature 70℃・Cylinder temperature 260℃・Injection pressure 1.190kg/cm”・Holding pressure 850kg/cm2・Screw rotation speed
The injection speed was 55 rpm, which was the maximum speed of this molding machine.

【Effect of the invention】

The method for producing an in-mold molded product having a hairline surface according to the present invention includes sequentially forming a release layer, a pattern layer, and an adhesive layer on the surface of a base sheet, which has hairline-shaped unevenness formed on its back surface in a portion where a hairline design is desired. transfer material,
Fix the transfer material at a predetermined position in the injection mold so that the adhesive layer side is in contact with the injection molding resin, close the mold,
Since the mold is configured to be filled with resin for injection molding, the convex portion of the hairline design obtained by transferring this transfer material has a rounded top, making the hairline resistant to crushing. It is highly scratch resistant.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of a transfer material used in the present invention. FIG. 2 is a sectional view showing an embodiment of the method for manufacturing an in-mold molded product having a hairline surface according to the present invention. DESCRIPTION OF SYMBOLS 1... Base sheet, 2... Resin, 3... Peeling layer,
4... Design layer, 5... Adhesive layer, 6... Transfer material, 7
... Resin for injection molding, 8... Mold. Patent applicant: Nissha Printing Co., Ltd. Figure 2 1...Base sheet 2...Resin 3...Peeling layer 4...Design layer 5...Adhesive layer 6...Transfer material 7...・Resin 8 for injection molding...Mold

Claims (3)

[Claims] (1) A base sheet with hairline-shaped irregularities formed on its back surface in areas where a hairline design is desired. (1) A release layer (3), a pattern layer (4), and an adhesive layer (5) are sequentially formed on the surface. Fix the transfer material (6) at a predetermined position in the injection mold (8) so that the adhesive layer (5) side of the transfer material (6) is in contact with the injection molding resin (7), and A method for producing an in-mold molded product having a hairline surface, which comprises closing a mold (8) and filling the mold (8) with a resin (7) for injection molding. (2) A method for producing an in-mold molded product having a hairline surface according to claim 1, wherein desired portions of the hairline-shaped unevenness of the base sheet (1) of the transfer material are filled with the resin (2). (3) A method for manufacturing an in-mold molded product having a hairline surface according to claim 1, wherein the pattern layer (4) of the transfer material includes a metal thin film layer.