JP2005053086A - Decorative sheet and laminated decorative material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decorative sheet not causing trouble such that the residual solvent of an adhesive layer is evaporated to foam when the decorative sheet is molded and laminated on an adherend using hot pressing like a vacuum forming lamination method and the in-mold decoration method of an injection molding in-mold lamination method, and a laminated decorative material. <P>SOLUTION: In the decorative sheet obtained by successively laminating a printing layer and an adhesive layer on a base material sheet comprising a through resin, 10-60 wt.% of fine particles with a mean particle size of 0.1 μm or below is added to the adhesive layer of the dcecorative sheet. The surface of the adhesive layer of this decorative sheet is bonded and laminated to the surface of the adherend comprising the thermoplastic resin to obtain the laminated decorative material and the adhesive layer or this laminated decorative material contains 10-60 wt.% of fine particles with a mean particle size of 0.1 μm or below. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a decorative sheet and a laminate decorative material particularly suitable for a molded simultaneous decorative sheet that is molded by hot pressure of a vacuum molding lamination method or an injection molding lamination method and laminated on an adherend.

Conventionally, a vacuum molding lamination method (Patent Document 1), an injection molding lamination method (Patent Document 2), and the like are known as methods for forming and laminating a decorative sheet by heat and pressure on an adherend of a resin molded product. . As one of typical examples, an adhesive layer surface of a decorative sheet formed by sequentially laminating a printing layer and an adhesive layer on a base material sheet made of a thermoplastic resin is adhesively laminated on the surface of an adherend made of a thermoplastic resin. There is a laminated cosmetic material. It is known that by using such a configuration, surface properties, a feeling of painting, and the like are imparted to the adherend, and adhesion to the adherend, handleability, and the like are imparted by the base sheet. As a method for laminating a laminate decorative material, a laminating method has been used in which an adhesive layer is applied and dried on the surface of a base material sheet provided with a printing layer, and is then adhered and laminated on an adherend by hot pressing. In this method, both the front and back surfaces of the adhesive layer are sandwiched between non-breathable resins. At this time, the adhesive is usually dried after drying the solvent so that the residual solvent does not remain as much as possible. Depending on the amount, the dry state, and the lamination conditions, the solvent cannot be sufficiently dried at the time of coating the adhesive layer, and the solvent remains in the adhesive layer to some extent. When the laminated decorative material obtained by this lamination is used for simultaneous molding decoration such as a vacuum molding lamination method or an injection molding simultaneous lamination method, there may be a problem that the residual solvent in the adhesive layer evaporates and foams. If such foaming occurs, not only the designability is lowered, but also the surface hardness of the product is lowered.

  In the past, after applying and drying the pattern layer and adhesive layer, the decorative sheet is heat-dried in a later process, and the residual solvent contained in the decorative sheet is defined by regulating the weight change rate before and after the heat-drying of the decorative sheet to a certain amount or less. There is a proposal (Patent Document 3) that manages the amount and eliminates the problems caused by foaming. However, in this method, the thermal drying process for controlling the weight change rate of the decorative sheet to a certain amount or less and the management of the weight change rate of the decorative sheet It was something that required extra cost and time.

Japanese Examined Patent Publication No. 56-45768 Japanese Patent Publication No. 45-1758 JP 2002-273830 A

  The object of the present invention is to form a decorative sheet on an adherend by using hot pressure as in the vacuum molding / laminating method and the simultaneous molding / molding method of the injection molding simultaneous lamination method. Thus, it is an object of the present invention to provide a decorative sheet and a laminate decorative material that do not cause a problem that the residual solvent in the adhesive layer is vaporized and foamed without special treatment such as heat drying.

In order to solve the above problems, the decorative sheet of the present invention is a decorative sheet comprising an adhesive layer on a base material sheet made of a thermoplastic resin, and the adhesive layer contains 10 to 60 fine particles having an average particle diameter of 0.1 μm or less. It was set as the structure containing weight%.
The laminated decorative material of the second invention is obtained by adhering and laminating an adhesive layer surface of a decorative sheet obtained by sequentially laminating a printing layer and an adhesive layer on a base material sheet made of a thermoplastic resin on a surface of an adherend made of a thermoplastic resin. The laminated decorative material, wherein the adhesive layer contains 10 to 60% by weight of fine particles having an average particle size of 0.1 μm or less.

By adopting the decorative sheet configuration of the present invention, the laminate decorative material in which the decorative sheet is bonded to the adherend (sheet) is less susceptible to a decrease in adhesive force due to melting, softening, etc. of the adhesive layer even when heated. It is possible to suppress a problem that the residual solvent is vaporized and foamed between sheets. Therefore, a decorative sheet suitable for a simultaneous molding decoration method such as a vacuum molding lamination method or an injection molding simultaneous lamination method in which a decorative sheet is heated is used.

Embodiments of the present invention will be described below.
As the base sheet, a sheet made of a thermoplastic resin that can be molded by a vacuum molding lamination method or an injection molding simultaneous lamination method is used. As the thermoplastic resin constituting the base sheet, for example, polyethylene, polypropylene, polybutene, ethylene propylene copolymer, ethylene-vinyl acetate copolymer, polyethylene terephthalate, acrylic, vinyl chloride, polycarbonate, polyamide, etc. can be used. is there. Particularly preferred is a resin mainly composed of a methacrylic acid ester such as methyl methacrylate, and it may contain a colorant or an additive for the purpose of coloring or improving sheet physical properties. Further, the thickness of the base sheet is desirably 20 μm to 300 μm in terms of workability and proper printing.

  Examples of the colorant include carbon black, titanium white, 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 pigment, luminescent pigment, or a mixture of two or more selected from these can be used.

  Further, the front and back surfaces of the substrate sheet may be appropriately subjected to a known easy adhesion treatment, that is, an adhesion enhancing treatment such as corona discharge treatment, plasma treatment, ozone treatment, primer layer coating, etc., as necessary.

  Since the printed layer is located between the base sheet and the adherend, the printed layer is protected from the front and back surfaces with a resin, and is excellent in durability at the manufacturing stage and in the final product state. For example, in the case of the injection molding simultaneous lamination method, it is possible to prevent the resin injected by hot pressure from contacting the substrate sheet surface, and the printed layer from flowing out or being damaged.

  In addition, when a FRP reinforcing layer is provided on the base sheet side of the decorative sheet by laminating the decorative sheet on the adherend, by using the hand lay-up method or spray-up method, the printed layer is prevented from being dissolved or washed away by the reinforcing layer resin. I can do it.

  The printing layer is formed on the entire surface or a desired portion by a known printing method such as gravure printing, letterpress printing, offset printing, silk screen printing, transfer printing, ink jet printing, and hand drawing. 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 ink for the printing layer consists of a vehicle consisting of a binder, a colorant, and an additive. The binder resin is an ethylene-vinyl acetate copolymer, an acrylic resin, a polyester resin, a vinyl chloride resin, a vinyl chloride-vinyl acetate copolymer, Chlorinated polypropylene, epoxy resin, cellulose, urethane resin, etc. can be used. Moreover, a well-known pigment and dye can be used for a coloring agent, for example, the coloring agent enumerated by description of the base material sheet mentioned above can be used.

  An easy-adhesion layer may be provided on the surface opposite to the adhesive layer of the base sheet to ensure adhesion with the injection molding resin or the FRP reinforcing layer. For example, ethylene-vinyl acetate copolymer, acrylic resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, chlorinated polypropylene, epoxy resin, cellulose, urethane resin, polyester resin and the like can be used.

  The adhesive layer is a layer for bonding the base sheet provided with the printing layer to the adherend. The adhesive layer is basically not limited as long as it is a resin capable of bonding the base sheet and the adherend, and various thermoplastic resin materials can be used. Specifically, acrylic resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate resin, urethane resin, polyester resin, epoxy resin, ethylene-vinyl acetate resin, polyamide resin, etc. can be used, but are not limited to this. Is not to be done. Note that an adhesive layer made of a two-component curable resin such as a urethane resin or an epoxy resin has good heat resistance and can further suppress foaming during heating, which is suitable for the use of the present invention. The thickness of the adhesive layer is not particularly limited, but is desirably in the range of 0.1 μm to 20 μm so that the solvent hardly remains.

  In the present invention, the glass transition point (Tg) of the binder of the adhesive layer is desirably 50 ° C. to 110 ° C. When the Tg of the adhesive layer is less than 50 ° C., the adhesive force between the decorative sheet and the adherend decreases due to melting and softening of the adhesive layer during high-temperature heating, and the residual solvent in the adhesive layer evaporates and foams between the sheets. This is not preferable because defects are likely to occur. Further, when the Tg of the binder of the adhesive layer exceeds 110 ° C., it is not preferable because it is difficult to thermally bond the decorative sheet and the adherend.

  The solvent for the adhesive layer is preferably selected in consideration of the solubility of the adhesive resin, the affinity with the sheet material, the volatilization rate, etc., and the one having as little residual solvent as possible. For example, esters such as ethyl acetate and butyl acetate , Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, hydrocarbons such as pentane, hexane, heptane, toluene, xylene, alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, ethylene glycol, ethyl ether, One or a mixture of two or more of ethers such as methyl ether and water can be used.

  The substrate sheet and the adherend are bonded by a dry laminating method in which the solvent of the applied adhesive layer is dried and then bonded. At that time, it is desirable that the adhesive layer be sufficiently dried so that the solvent does not remain as much as possible.

The fine particles added to the adhesive layer are added to prevent the adhesive layer from lowering the adhesive force due to melting and softening of the adhesive layer when heating the decorative sheet, and to reduce the problem that the residual solvent in the adhesive layer evaporates and foams between the sheets. To do. Addition of fine particles with an average particle size of 0.1 μm or less to the adhesive layer suppresses melting and softening of the adhesive layer during high-temperature heating, and a high adhesive force is obtained, so the residual solvent in the adhesive layer evaporates and foams between the sheets Defects can be reduced. Here, when the average particle diameter exceeds 0.1 μm, the effect of the present invention is reduced because the effect of suppressing the decrease in adhesive force due to melting and softening of the adhesive layer during the high-temperature heating is low. In addition, if the average particle diameter exceeds 0.1 μm, the coated surface of the adhesive layer becomes rough, so when adhering the decorative sheet to the adherend, air is mixed in the vicinity of the particles when the decorative sheet is heated. Since the air thermally expands, the adhesive strength between the decorative sheet and the adherend is reduced, and the design is not preferable.
In addition, if the average particle size is 0.1 μm or less, the adhesive layer is highly transparent, and the printed layer is not concealed, so that high designability is obtained. The average particle size is measured using a so-called BET method in which molecules with a known adsorption area are adsorbed on the particle surface at the temperature of liquid nitrogen, and the specific surface area of the sample is calculated from the amount to calculate the particle size. .

  If the amount of particles added to the adhesive layer is less than 10%, it is difficult to obtain the effects of the present invention, so it is necessary to add 10% or more to the adhesive layer. Further, the maximum amount of addition is required to be 60% or less in order to secure the adhesion performance with the adherend.

  Various inorganic and organic fine particles can be used as the fine particle material added to the adhesive layer. For example, silica, alumina, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum silicate, calcium silicate, Zeolite, mica, carbon black, titanium white, zinc white, dial, 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 pigment, luminescent pigment, or a mixture of two or more selected from these can be used. In addition, since the adhesive layer needs to have transparency that does not cover the printing layer, substantially transparent fine particles such as silica, alumina, calcium carbonate, and zinc oxide are preferable. In particular, when a silica sol having an average particle size of 0.1 μm or less is added to the adhesive layer, the adhesive layer is extremely transparent and suitable for the use of the present invention because high printability is obtained because the printed layer is not concealed. .

As the adherend, a sheet made of a thermoplastic resin that can be molded by a vacuum molding lamination method or an injection molding simultaneous lamination method is used. As the thermoplastic resin constituting the adherend, the various resins listed in the base sheet can be used, but since it is located on the outermost surface of the product, it is substantially transparent and has excellent surface hardness and weather resistance. Acrylic resin or the like is preferable. In addition, the thickness of the adherend is usually not limited to about 50 to 5000 μm. Also, the adherend may be subjected to a known easy adhesion treatment, similarly to the base sheet.
The method for laminating the decorative sheet on the adherend will be described below.

  (1) Vacuum forming and laminating method: As described in Japanese Patent Publication No. 56-45768, the surface of a three-dimensional adherend such as a molded article is opposed to the decorative sheet via an adhesive layer, and the adherend side A method of laminating a decorative sheet on an adherend by a pressure difference due to vacuum suction from the substrate.

  (2) Simultaneous injection molding method: After placing a decorative sheet between both male and female molds for injection molding as described in JP-B-50-19132, the resin in a fluid state is injected and filled into the mold. There is an injection molding simultaneous decorating method in which a decorative sheet is integrally formed on the surface of a resin molded product at the same time. When the decorative sheet is deeply drawn, it is desirable to preform the decorative sheet by vacuum forming.

  (3) A method of laminating a reinforcing member after vacuum forming; after a decorative sheet is vacuum-formed as described in JP-A-5-237924, a glass fiber reinforced unsaturated polyester resin (hereinafter referred to as a glass fiber reinforced unsaturated polyester resin) A method of laminating reinforcing members such as FRP) is known.

FIG. 1 is a schematic cross-sectional view showing the form of the decorative sheet of the present invention.
FIG. 2 is a schematic cross-sectional view showing the form of the laminated decorative material of the present invention in which a decorative sheet and an adherend are bonded together.
FIG. 3 is a diagram in which the laminated decorative material of the present invention is set in a vacuum forming apparatus.
FIG. 4 is a view showing a state in which the laminated decorative material is heated and softened by the heater 7 in FIG. 3 and then decompressed by the vacuum suction hole 8 to form the laminated decorative material along the surface of the mold 10.
FIG. 5 is a diagram showing foaming generated in the adhesive layer when the particles of the present invention are not contained in the adhesive layer of the laminated decorative material in the vacuum forming step of FIGS. 3 to 4.
Hereinafter, the present invention will be further described by examples and comparative examples.

On a transparent substrate sheet made of acrylic resin and having a thickness of 75 μm, a stone-like printing layer was formed at a printing speed of 80 m / min by gravure printing using urethane resin printing ink for building materials. Next, a coating solution prepared by dissolving a vinyl chloride-vinyl acetate copolymer and a silica sol having an average particle size of 15 nm in MEK in a solid weight ratio of 80 parts by weight and 20 parts by weight is dried with a gravure roll coater. A decorative sheet was prepared by laminating and drying on the printed layer so as to be 2 μm. Next, lamination was performed by using two rubber rolls heated to 130 ° C. so that the adhesive layer surface of the base sheet faced the surface of the adherend having a thickness of 5 mm made of an acrylic resin, thereby producing a laminate decorative material.

A laminated decorative material was prepared in the same manner as in Example 1 except that the particles in the adhesive layer in Example 1 were changed to silica having an average particle size of 0.1 μm.

A laminated decorative material was prepared in the same manner as in Example 1 except that the particles of the adhesive layer in Example 1 were changed to zinc oxide having an average particle size of 10 nm.

A laminated decorative material was prepared in the same manner as in Example 1 except that the binder of the adhesive layer in Example 1 was changed to polymethacryl methacrylate resin.

A laminated decorative material was prepared in the same manner as in Example 1 except that the vinyl chloride-vinyl acetate copolymer and silica sol in the adhesive layer were changed to 90 parts by weight and 10 parts by weight in the solid content.

A laminate decorative material was prepared in the same manner as in Example 1 except that the vinyl chloride-vinyl acetate copolymer and silica sol in the adhesive layer were changed to 40 parts by weight and 60 parts by weight in solid content in Example 1.

A laminated decorative material was prepared in the same manner as in Example 1 except that the film thickness of the adhesive layer in Example 1 was changed to 10 μm.

When the laminated decorative material obtained in Examples 1 to 7 was vacuum-formed with a vacuum forming apparatus and the occurrence of problems due to foaming of the laminated decorative material was confirmed, no problems that would cause a practical problem occurred. Further, when the laminated decorative material obtained in Example 1 is viewed from the adherend side, the transparency of the adhesive layer is higher than that of the laminated decorative material of Examples 2 and 3, the printed layer is clear, and the design property is particularly high. It was excellent.
Comparative Example 1

A laminated decorative material was prepared in the same manner as in Example 1 except that silica having an average particle diameter of 0.5 μm was used for the adhesive layer particles in Example 1. The obtained laminated decorative material was vacuum-formed with a vacuum forming apparatus, and it was impossible to use due to frequent occurrence of foaming as a result of confirming the occurrence of defects due to foaming of the laminated decorative material.
Comparative Example 2

A laminated decorative material was prepared in the same manner as in Example 1 except that melamine particles having an average particle diameter of 3 μm were used for the adhesive layer in Example 1. The obtained laminated decorative material was vacuum-formed with a vacuum forming apparatus, and it was impossible to use due to frequent occurrence of foaming as a result of confirming the occurrence of defects due to foaming of the laminated decorative material.
Comparative Example 3

A laminated decorative material was prepared in the same manner as in Example 1 except that the adhesive layer was composed only of vinyl chloride-vinyl acetate copolymer in Example 1. The obtained laminated decorative material was vacuum-formed with a vacuum forming apparatus, and it was confirmed that a failure occurred due to foaming of the laminated decorative material.

The present invention can be used for surface decoration of plastic products such as automobile interior and exterior products, home appliances, mobile phones, and building materials, and can be used not only for decorating flat supports but also for vacuum forming on uneven surfaces. It can be used as a decorative sheet.

It is a schematic cross section which shows the form of the decorative sheet of this invention. It is a schematic cross section which shows the form of the laminated decorative material of this invention. It is the figure which set the laminated decorative material of this invention to the vacuum forming apparatus. FIG. 4 is a view showing a state in which the laminated decorative material is heated and softened by the heater 7 in FIG. 3, and then the pressure is reduced by the vacuum suction hole 8, and the laminated decorative material is molded along the surface of the mold 10. FIG. 5 is a diagram showing foaming that occurs in the adhesive layer when the particles of the present invention are not contained in the adhesive layer of the laminated decorative material in the vacuum forming step of FIGS. 3 to 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cosmetic sheet 2 ... Base material sheet 3 ... Printing layer 4 ... Adhesive layer 5 ... Adhering body 6 ... Laminate cosmetic material 7 ... Heater 8 ... Vacuum suction Hole 9 ... Clamp 10 ... Die 11 ... Bubble

Claims (2)

A decorative sheet obtained by sequentially laminating a printing layer and an adhesive layer on a base material sheet made of a thermoplastic resin, wherein the adhesive layer contains 10 to 60% by weight of fine particles having an average particle diameter of 0.1 μm or less. Makeup sheet. A laminate decorative material formed by adhering and laminating an adhesive layer surface of a decorative sheet formed by sequentially laminating a printing layer and an adhesive layer on a base material sheet made of a thermoplastic resin on a surface of an adherend made of a thermoplastic resin, A laminate decorative material, wherein the adhesive layer contains 10 to 60% by weight of fine particles having an average particle size of 0.1 μm or less.

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