JP3801599B2 - Molded product manufacturing method and transfer sheet used therefor - Google Patents

Description

  The present invention relates to a method for producing a molded article by vacuum forming using a transfer sheet that can be recorded by an oil-based ink jet method, and a transfer sheet used therefor.

  As a method of obtaining a resin molded product having excellent design properties, a method of vacuum forming a resin plate that has been printed in advance is known. (For example, refer to Patent Document 1) As a method for forming those print layers, known printing techniques such as normal gravure printing, offset printing, silk screen printing, and ink jet printing can be used. Among these, ink jet printing is a simple output method. In addition, there are features such as good print quality and low cost when printing in a small lot.

  However, when printing directly on a resin plate before vacuum forming by ink jet, it is necessary to apply an ink jet image receiving layer on the surface of the resin plate, which is not preferable in terms of cost. Further, in this method, the surface of the molded product finally obtained is a printing surface, so the surface durability is inferior. Further, when the printing method is an ink jet method using water-based ink, the surface of the obtained molded product is water resistant. It was inferior to.

There has also been proposed an inkjet recording pressure-sensitive adhesive sheet in which an image-receiving layer capable of recording by a water-based inkjet method is provided on a base sheet, and the recorded image-receiving layer surface has adhesiveness. If the material is vacuum formed, the printed portion of the finally obtained molded product is protected by the base sheet, and a molded product having excellent fastness can be obtained. (For example, see Patent Document 2)
However, the decorative material prepared by this method has a structure in which the volatile solvent contained in the ink-jet ink is sandwiched between a resin plate and a base sheet that are not permeable to air, and therefore remains in the image receiving layer by heating during vacuum forming. In some cases, the solvent contained in the inkjet ink, that is, the organic solvent or water foams at the interface between the resin plate and the base sheet. Furthermore, in the case of using the ink jet method using water-based ink, the sheet may peel off due to moisture permeating from the edge part of the interface between the resin plate and the adhesive sheet of the final molded product, and the water resistance is not sufficient. .

Japanese Examined Patent Publication No. 56-24568 JP 2002-241714 A

  In order to solve the above problems, an object of the present invention is to provide a method for producing a molded product excellent in design and water resistance by vacuum forming using a transfer sheet that can be recorded by an oil-based ink jet method, and a transfer used in the method. To provide a sheet.

In order to achieve the above-mentioned object, the present invention discharges ink according to image information by an oil-based inkjet method onto the surface of an image receiving adhesive layer of a transfer sheet provided on the base sheet so that the image receiving adhesive layer can be peeled off. A step of forming an image, a step of heating the image-formed transfer sheet to transfer the image-receiving adhesive layer to a resin plate, and then peeling off the base sheet to create a cosmetic material; and further vacuum-molding the cosmetic material It was set as the molded product manufacturing method characterized by comprising a process.

  Further, the present invention is a transfer sheet used in the method for producing a molded product, wherein at least an image receiving adhesive layer is provided on a base sheet so as to be peelable, and the image receiving adhesive layer can be printed by an oil-based inkjet method and is a resin plate The transfer sheet is characterized in that it can be thermally bonded to the sheet. Furthermore, the image receiving adhesive layer may have a vinyl chloride-vinyl acetate copolymer as a main component.

  By using the production method and transfer sheet of the present invention, it is possible to produce a small lot, and it is possible to obtain a molded product having excellent printing quality, water resistance and durability.

Embodiments of the present invention will be described below.
The base material sheet used in the present invention is a resin sheet that holds the image receiving adhesive layer in a peelable manner and is peeled off after the image receiving adhesive layer is transferred to a resin plate.

  Various resin sheets can be used as the base sheet, and polyethylene, polypropylene, polybutene, ethylene propylene copolymer, ethylene-vinyl acetate copolymer, polyethylene terephthalate, acrylic, vinyl chloride, polycarbonate, polyamide, etc. can be used. is there. Particularly preferably, it is a base sheet mainly composed of polyethylene terephthalate, and may contain additives for the purpose of improving sheet physical properties.

  The thickness of the base sheet is preferably 20 μm or more in terms of workability and ink jet printing suitability, and is a waste material that is peeled and removed after the image-receiving adhesive layer is transferred. It is not a thing. Moreover, you may give a well-known mold release process, an antistatic process, etc. suitably to a base material sheet as needed.

  The image-receiving adhesive layer is provided on the base sheet so as to be peelable, can be printed by an oil-based ink jet method, and has thermal adhesiveness to a resin plate. Here, as a component of the image receiving adhesive layer, it is desirable to contain 20 to 100% by weight of vinyl chloride-vinyl acetate copolymer. Since the image-receiving adhesive layer has a vinyl chloride-vinyl acetate copolymer as a main component, it is possible to obtain good adhesiveness to various thermoplastic resin materials such as ABS and acrylic, and furthermore, by an ink jet method using oil-based ink. Since printing is possible, it is possible to create a transfer sheet that takes advantage of features such as good print quality and low cost when printing in small lots.

  In addition, the image receiving adhesive layer containing 20 to 100% by weight of vinyl chloride-vinyl acetate copolymer has good thermoformability, and the decorative material obtained by transferring the image receiving adhesive layer to the surface of the resin plate is vacuum molded. Shows excellent moldability without cracking or cracking in the image-receiving adhesive layer. Further, the image receiving adhesive layer needs to substantially not exhibit adhesiveness in a room temperature environment. This is because when the transfer sheet is handled in the ink jet printing process, if the transfer sheet surface is sticky in a room temperature environment, the transfer sheet or the like that comes into contact with the transfer sheet surface may cause problems such as poor conveyance.

The vinyl chloride-vinyl acetate copolymer used for the image-receiving adhesive layer has a glass transition point of so-called Tg of 40 ° C. or higher so that the surface of the image-receiving adhesive layer does not substantially exhibit tackiness at room temperature. Although it is desirable to use it, it is not limited to this.
The vinyl chloride-vinyl acetate polymer composition ratio of the vinyl chloride-vinyl acetate copolymer used for the image-receiving adhesive layer is preferably in the range of 50:50 to 96: 4 of vinyl chloride: vinyl acetate. This is because if the composition ratio of vinyl chloride is higher than the above ratio, the adhesiveness is inferior, and if the composition ratio of vinyl chloride is lower than the above ratio, the recordability in the ink jet system using oil-based ink is inferior.

  In addition to the vinyl chloride-vinyl acetate copolymer, various resin materials, fine particles, ultraviolet ray inhibitors, antistatic agents, lubricants, and the like can be added to the image receiving adhesive layer. Specific examples of resins that can be added include acrylic resins, vinyl chloride resins, vinyl acetate resins, urethane resins, polyester resins, epoxy resins, ethylene-vinyl acetate resins, and polyamide resins, but are not limited thereto. It is not something.

  Examples of additives that can be added include silica, alumina, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum silicate, calcium silicate, zeolite, mica, carbon black, titanium white, and zinc white. , Petal, bitumen, cadmium red, azo pigment, lake pigment, anthraquinone pigment, phthalocyanine pigment, quinacridone pigment, isoindolinone pigment, imidazolone pigment, dioxazine pigment, gold powder, silver powder, copper powder, aluminum powder, fish scale powder, pearl pigment , Fluorescent pigments, luminescent pigments, or a mixture of two or more selected from these pigments can be used.

  The thickness of the image receiving adhesive layer is not particularly limited, but is preferably 2 μm or more in order to ensure adhesion with the resin plate, and is preferably 100 μm or less in consideration of productivity. In addition, since the molded product obtained by the production method of the present invention has a pattern in which the pattern is covered and protected by the image receiving adhesive layer, the thickness of the image receiving adhesive layer is 2 μm or more in order to ensure the durability of the final product. desirable.

  As the resin plate used in the present invention, a resin plate made of a thermoplastic resin that can be molded in a vacuum forming method can be used, and a resin plate made of various resin materials as mentioned in the material of the base sheet is used. Is possible. The thickness of the resin plate can be about 50 to 5000 μm, but is not particularly limited. Also, the resin plate may be subjected to a known easy adhesion treatment or antistatic treatment as in the case of the base sheet.

  A printing layer may be formed on the entire surface or a desired portion between the base sheet and the image receiving adhesive layer by a known printing method such as gravure printing, letterpress printing, offset printing, silk screen printing, transfer printing, or hand-drawing method. The pattern formed by printing is not particularly limited, such as wood grain, stone grain, cloth grain, sand grain, letters, symbols, and the like.

  The printing layer ink is mainly composed of a vehicle comprising a binder, a colorant, and an additive. The binder resin includes ethylene-vinyl acetate copolymer, acrylic resin, polyester resin, vinyl chloride resin, vinyl chloride-vinyl acetate. Copolymers, chlorinated polypropylene, epoxy resins, cellulose, urethane resins and the like can be used.

  Also, known pigments and dyes can be used as the colorant. For example, carbon black, titanium white, zinc white, petal, bitumen, cadmium red, azo pigment, lake pigment, anthraquinone pigment, phthalocyanine pigment, quinacridone pigment, An isoindolinone pigment, imidazolone pigment, dioxazine pigment, gold powder, silver powder, copper powder, aluminum powder, fish scale powder, pearl pigment, fluorescent pigment, luminescent pigment, or a mixture of two or more selected from these can be used.

FIG. 1 is a schematic cross-sectional view showing the form of the transfer sheet of the present invention. The transfer sheet 1 is provided with an image receiving adhesive layer 3 on a base sheet 2 so as to be peelable.
FIG. 2 is a schematic cross-sectional view showing the form of the decorative material of the present invention, and the decorative material 5 is obtained by transferring the image-receiving adhesive layer 3 on which an image has been formed to the resin plate 4.
FIG. 3 is a schematic cross-sectional view showing a state in which the decorative material 5 of the present invention is set in a vacuum forming apparatus. After the decorative material 5 is fixed by the fixing frame 8, it faces the mold 9 surface of the vacuum forming apparatus. It is set to. A heater 6 is installed on the top of the decorative material 5.
FIG. 4 is a schematic cross-sectional view showing a state in which the decorative material 5 is vacuum-formed by the vacuum forming apparatus in FIG. 3. After the decorative material 5 is heated and softened by the heater 6, the pressure is reduced by the vacuum suction hole 7. The material 5 is formed along the surface of the mold 9.

  Hereinafter, the present invention will be further described by examples and comparative examples.

A coating solution prepared by dissolving 20 parts by weight of a vinyl chloride-vinyl acetate copolymer (trade name, VAGH) manufactured by Union Carbide in 80 parts by weight of methyl ethyl ketone in a base sheet made of polyethylene terephthalate having a thickness of 25 μm was used as a Meyer bar coater. The transfer sheet was prepared by laminating the image-receiving adhesive layer by applying and drying to 10 μm when dried. Next, a pattern was formed on the surface of the image-receiving adhesive layer of the obtained transfer sheet by an ink jet method using oil-based ink, and a transfer sheet on which the pattern was formed was created. Furthermore, to face the resin plate surface of 4mm thick image-receiving adhesive layer surface of the transfer sheet obtained in made of polymethyl methacrylate, after transferring the image receiving adhesive layer using two rubber rolls heated to 130 ° C., group The material sheet was peeled off to create a decorative material.
[Example 2]

In Example 1, except that an ABS resin plate having a thickness of 1 mm was used as the resin plate, a base material sheet was peeled off in the same manner as in Example 1 to prepare a decorative material to which the image receiving adhesive layer was transferred.
[Example 3]

As the image-receiving adhesive layer in Example 1, vinyl chloride - vinyl acetate copolymer 20 parts by weight polymethacrylic methacrylate except that the resin 80 parts by weight was used a coating solution obtained by dissolving in methyl ethyl ketone 400 parts by weight similarly groups as in Example 1 The material sheet was peeled off to create a decorative material.
[Example 4]

Example 1 is the same as Example 1 except that a coating solution in which 40 parts by weight of titanium oxide is dispersed in a resin solution in which 60 parts by weight of vinyl chloride-vinyl acetate copolymer is dissolved in 300 parts by weight of methyl ethyl ketone is used as the image receiving adhesive layer. Similarly, the base material sheet was peeled off to prepare a decorative material.
[Example 5]

Similar to Example 1, except that a concealing layer composed of 60 parts by weight of vinyl chloride-vinyl acetate copolymer and 40 parts by weight of titanium oxide was provided between the image-receiving adhesive layer and the base sheet in Example 1 with a thickness of 30 μm. The base material sheet was peeled off to create a decorative material on which a pattern was formed.

  When the decorative material obtained in Examples 1 to 5 was vacuum-formed with a vacuum forming apparatus, the transferred image-receiving adhesive layer and the pattern were free from cracks and cracks, and the obtained molded product had excellent water resistance. Met. In addition, the molded article prepared by vacuum forming the decorative sheet obtained in Examples 1 to 4 with a vacuum forming apparatus has high transparency even when viewed from the base sheet side, and printing is clear and design is particularly good. It was excellent.

[Comparative Example 1] A coating solution in which 50 parts by weight of an acrylic ester resin was dissolved in 400 parts by weight of water was applied to a 75 μm thick acrylic resin base sheet so that it would be 10 μm when dried with a Mayer bar coater. The transfer sheet was prepared by drying. Next, after forming a pattern on the surface of the obtained transfer sheet by an aqueous inkjet method, the image receiving surface of the obtained decorative sheet is made to face the surface of a resin plate made of polymethyl methacrylate and having a thickness of 4 mm, and two rubber rolls are used. A decorative sheet was laminated to make a decorative material in which the base sheet was in close contact .

[Comparative Example 2] A coating solution prepared by dissolving 20 parts by weight of a vinyl chloride-vinyl acetate copolymer in 80 parts by weight of methyl ethyl ketone in an acrylic resin base sheet having a thickness of 75 μm is 10 μm when dried with a Mayer bar coater. A decorative sheet having an image receiving adhesive layer laminated thereon was prepared by coating and drying as described above. Next, after forming a pattern on the surface of the obtained decorative sheet by an oil-based ink jet method, the image receiving surface of the obtained decorative sheet is made to face the surface of a resin plate made of polymethyl methacrylate and having a thickness of 4 mm, and two rubber rolls are used. A decorative sheet was laminated to make a decorative material in which the base sheet was in close contact .

(Evaluation methods)
(Inkjet recording suitability) The suitability of printing when printing on the surface of the image-receiving adhesive layer with an oil-based inkjet printer (trade name: JV-3 / Mimaki Engineering Co., Ltd.) was evaluated. However, Comparative Example 1 evaluated the recording aptitude when printed by an aqueous inkjet printer (trade name: PX-7000 / manufactured by Seiko Epson Corporation).
○: Clear and high image quality.
(Triangle | delta): Although the ink spreads a little, the image quality which is satisfactory practically was obtained.
X: A clear image quality was not obtained.

(Vacuum formability) Formability when formed with a vacuum forming machine was evaluated.
○: Vacuum forming is possible without problems.
Δ: Bubbles may be generated by heating during molding.
X: Many bubbles are generated and there is no practicality.

(Water resistance) After the molded article was immersed in water for 24 hours, the deterioration of the pattern was evaluated.
○: No change in image quality ×: The pattern was completely peeled off.
The above evaluation results are as shown in Table 1 below.

It is a schematic cross section which shows the form of the transfer sheet of this invention. It is a schematic cross section which shows the form of the decorative material of this invention. FIG. 4 is a schematic cross-sectional view showing a state in which the decorative material of the present invention is fixed by a fixing frame 8 and then set so as to face a mold surface of a vacuum forming apparatus. FIG. 4 is a schematic cross-sectional view showing a state in which the decorative material 5 is heated and softened by the heater 6 in FIG. 3 and then decompressed by the vacuum suction hole 7, and the decorative material 5 is vacuum-formed along the surface of the mold 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transfer sheet 2 ... Base material sheet 3 ... Image receiving adhesive layer 4 ... Resin board 5 ... Cosmetic material 6 ... Heater 7 ... Vacuum suction hole 8 ... Fixed frame 9 ... Mold

Claims (3)

A step of forming an image by ejecting ink according to image information by an oil-based ink jet method on the surface of the image receiving adhesive layer of the transfer sheet provided with at least the image receiving adhesive layer on the substrate sheet so as to be peelable; A molded article comprising: a step of heating the transferred sheet and transferring the image-receiving adhesive layer to a resin plate; then , peeling off the base sheet and creating a decorative material; and further vacuum forming the decorative material Production method. It is a transfer sheet used for the molded article manufacturing method of Claim 1, Comprising: At least an image receiving adhesive layer is provided on a base material sheet so that peeling is possible, The said image receiving adhesive layer can be printed by an oil-based inkjet system, and is on a resin board. A transfer sheet that can be thermally bonded to the transfer sheet. 3. The transfer sheet according to claim 2, wherein the image receiving adhesive layer contains a vinyl chloride-vinyl acetate copolymer as a main component.

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