JP2001138468A - Decorative sheet and method for decorating molding using decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet which imparts a feel of irregularity to a molding and shows a good design attractiveness without being affected by the heat during molding. SOLUTION: A pattern of irregularities is formed on the back of a base sheet 1 formed of a transparent thermoplastic resin by machine cutting, and further, a decorative layer 2 is formed on the pattern of irregularities. Another colored thermoplastic resin sheet may be laminated on the decorative layer 2. In addition, an adhesive layer 3 may be laminated on the decorative layer 2 or the colored thermoplastic resin sheet. Because it is difficult to propagate heat to the pattern of irregularities during heating the decorative sheet S and also a residual stress which could be unleashed by heat is not accumulated in the resin of the pattern of irregularities part on account of the irregularities formed by machine cutting, the possibilities that the irregularities might be levelled during molding are eliminated. Thus, despite the presence of the pattern of irregularities at the internal interface of the decorative sheet S, it is possible to clearly recognize the pattern from outside by light reflection upon the internal interface of the decorative sheet S due to the presence of the decorative layer 2 on the back of the pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a decorating method for providing a picture by laminating a decorative sheet on the surface of a resin molded product.

[0002]

2. Description of the Related Art Conventionally, as a method of decorating a resin molded product by laminating and adhering a decorative sheet on the surface thereof, a decorative sheet is inserted between male and female molds of injection molding, and both molds are engaged with each other. There is known an injection molding simultaneous decoration method in which a molten resin is injected into a cavity after mold clamping, and a decorative sheet is laminated and adhered to the surface of a resin molded product. Further, there is also known a vacuum forming and decorating method in which a decorative sheet is heated and softened, and the decorative sheet is laminated and adhered to the surface of the adhered molded article by vacuum suction at least from the adhered molded article side.

[0003] In these methods, when a molded article is made to have an uneven feeling, a decorative sheet on which a shadow of the unevenness is printed is used. Alternatively, an embossed pattern having an uneven pattern is engraved on the surface of the mold, and the molten resin is injected onto the surface of the mold,
Filling and solidification are also performed. Further, prior to decoration, a decorative sheet made of a thermoplastic resin sheet is previously softened by applying heat with a hot press or the like, and an embossed plate is pressed thereon to form an uneven pattern.

[0004]

However, in the case of using a decorative sheet on which a shade of unevenness is printed, the appearance of the unevenness looks the same even when the incident angle of light from the light source is changed because the unevenness is expressed by printing ink. There is a disadvantage that.
Also, in the method of using a mold engraved with embossed patterns, another mold is required to make a product without uneven patterns, and as many molds as the number of uneven patterns are required. Therefore, there is a problem that not only the cost increases but also a storage space for the mold is required. In the method of embossing an embossed pattern by softening a decorative sheet in advance, the stress in the sheet of the embossed pattern portion tends to restore the original flat surface. There is a problem that the residual stress (restoring force) is released by the heat of the process and the injection molding process, and the previously processed uneven pattern is restored and becomes flat.

[0005] The present invention is intended to solve these problems, and an object of the present invention is to provide a decorative sheet capable of imparting a sense of unevenness to a molded product, which is not affected by heat during molding. It is an object of the present invention to provide a decorative sheet which is not subjected to a decoration and has a good design feeling, and a method for decorating a molded article using the same.

[0006]

In order to achieve the above-mentioned object, the decorative sheet of the present invention has an uneven pattern formed on the back surface of a base sheet made of a transparent thermoplastic resin by mechanical cutting. It is characterized in that a decorative layer is formed thereon. Then, a colored thermoplastic resin sheet may be further laminated on the decorative layer. Further, an adhesive layer may be further laminated on the decorative layer or the colored thermoplastic resin sheet.

In a first decorating method according to the present invention, the decorative sheet is inserted between the male and female molds of the injection molding so that the front side of the decorative sheet faces the female mold, and then the decorative sheets are engaged. After closing together, the molten resin is injected and filled from the male mold into the cavity formed between the two molds, cooled and solidified to form a molded product, and the decorative sheet is laminated on the surface of the molded product. It is characterized by bonding.

[0008] In a second decorating method according to the present invention, the decorative sheet is heated and softened, and the decorative sheet is attached by at least a pressure difference between the front and back of the decorative sheet by vacuum suction from the adhered molded article side. It is characterized by being laminated and adhered to the surface of the molded article.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A transparent thermoplastic resin used for a base sheet of a decorative sheet needs to be heated and softened in a vacuum molding step and an injection molding step, so that it is 100 to 100%.
Those that soften at a temperature of about 150 ° C are preferred. Specifically, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-propylene-
Polyolefin resins such as butene copolymers, olefinic thermoplastic elastomers, polyethylene terephthalate, polybutylene terephthalate, ethylene-terephthalate-isophthalate copolymers, polyester resins such as polyester-based thermoplastic elastomers, polystyrene, acrylonitrile-styrene copolymer A single-layer sheet of a resin such as a styrene-based resin such as acrylonitrile-butadiene-styrene copolymer (ABS), an acrylic resin, polycarbonate, polyvinyl chloride, and nylon, or a laminated sheet of these sheets is exemplified. The base sheet usually has a thickness of about 50 to 300 μm (total thickness in the case of a laminated sheet). Further, an appropriate amount of a coloring agent (transparent coloring), an ultraviolet absorber, a lubricant, a lubricant, an antistatic agent and the like may be added as long as the visibility of the uneven pattern on the back surface is not hindered.

[0010] Of the above resins, when the decorative sheet requires transparency or weather resistance, an acrylic resin is most commonly used. Examples of the material of the acrylic resin sheet include poly (methyl) acrylate, poly (meth) ethyl acrylate, poly (meth) butyl acrylate, methyl (meth) acrylate-butyl (meth) acrylate copolymer, Methyl (meth) acrylate-ethyl (meth) acrylate copolymer, ethyl (meth) acrylate-
An acrylic resin composed of a homo- or copolymer of a (meth) acrylate such as a (meth) butyl acrylate copolymer or a (meth) acrylate-styrene copolymer is used. In addition, (meth) acrylic acid shall mean "acrylic acid or methacrylic acid". The acrylic resin sheet usually has a thickness of about 50 to 300 μm, but is not necessarily limited to this range, and varies depending on the application, molding conditions, required surface properties, and the like. In particular, acrylics are used because they reduce the amount of heating during injection molding or preforming, keep the heating temperature low, shorten the molding cycle time, and facilitate the film formation and handling of sheets. It is preferable to set the glass transition temperature (Tg) of the resin to 80 ° C. or lower. Originally, the lower the Tg, the lower the abrasion resistance. However, this problem can be solved by setting the dynamic friction coefficient to 0.9 or less as described later.

When a decorative sheet using an acrylic resin sheet as a base sheet is laminated and adhered to the surface of a molded article by a simultaneous decoration method for injection molding, among acrylic resin sheets having a dynamic friction coefficient of 0.2 to 0.9. It is preferred to use If the coefficient of kinetic friction exceeds 0.9, stress is concentrated on the acrylic resin sheet when the acrylic resin sheet rubs against another object, and the surface is scratched. Conversely, if it is less than 0.2, the anti-scratch property is good, but when the shear stress due to the injected resin when the resin in the fluid state is injected into the cavity at high pressure acts on the sheet, the sheet slips and the mold When the sheet moves upward, the sheet is displaced, and wrinkles, distortions, tears, and the like occur. Thus, the sheet cannot be held on the mold surface against the drag (shear stress) of the injection resin.

The dynamic friction coefficient of the acrylic resin sheet is measured as follows. First, a target acrylic resin sheet is placed on a glass plate having a flat surface, and further on the acrylic resin sheet, a 10 mm square and a thickness of 1 mm
Place a piece of gauze wrapped on a plate of
Put a weight of g. Next, the weight is moved 1m horizontally.
The force during movement by pulling 10 cm at a speed of / min is measured with a spring and measured with a strain gauge or the like. And 5 of that power
The value obtained by dividing the point average value by the weight of the weight is defined as the dynamic friction coefficient.

The concave and convex pattern on the back surface of the base sheet is formed by shaving off a part of the back side of the base sheet with a metal knife or the like. The shaving process is usually performed at room temperature (about 10 to 30 ° C.), but may be heated or cooled to an appropriate temperature as needed. Actually, it is often cut in the vertical direction and processed into a hairline shape. Of course, in addition to this, the joint grooves of the tiles, the linear grooves, the fine irregularities (texture) of the texture of the fabric, the irregularities of the stone pattern, Alternatively, a relief pattern such as a floral pattern, a geometric pattern, or a character may be used. The concave portions of the formed concavo-convex pattern are filled with a coloring ink by a known wiping method as necessary. Filling with a coloring agent is preferable because the uneven pattern sandwiched between the base sheet and the molded product is easily visible. As the coloring ink, a urethane resin, an acrylic resin, a polyester resin, or another conventional vehicle to which a pigment or a dye is added is selectively used, and a two-liquid curing type having good adhesion and good solvent resistance is preferable. . Wiping may be performed by any of conventionally used wiping methods such as a doctor blade method and a roll coating method. By these methods,
A coloring ink is applied to the entire surface of the uneven pattern, and thereafter, the ink in the convex portion is scraped off to leave the coloring ink in the concave portion.

The decorative layer on the concave / convex pattern is provided on the back surface of the base sheet so that the concave / convex pattern on the back surface which is not directly visible from the front surface can be clearly seen. It is formed as a layer that has a ratio, is colored with a specific hue, lightness, and saturation, or has light reflectivity. Such a decorative layer may be, for example, a gravure print, a silk screen print, a pattern layer on which a pattern or the like is printed by a conventionally known method and material such as offset printing, or a metal such as aluminum, chromium, gold, or silver. A metal thin film layer or the like formed partially or entirely by a vapor deposition method, etc.
Use the one that suits your application. A wood pattern, a stone pattern, a cloth pattern, a tile pattern, a brick pattern, a leather pattern, a character, a geometric pattern, a solid pattern, or the like is used in accordance with the surface irregularities of the adhered molded product. The picture layer ink is composed of a vehicle such as a binder, a coloring agent such as a pigment or a dye, and various additives appropriately added thereto. A single material such as an acrylic resin, a vinyl chloride-vinyl acetate copolymer, a polyester resin, a cellulosic resin, a polyurethane resin, and chlorinated polypropylene, or a mixture containing them is used for the binder. Titanium white,
Inorganic pigments such as carbon black, red iron oxide, graphite and ultramarine blue, and organic pigments such as aniline black, quinacridone, isoindolinone, and phthalocyanine blue are used.

The colored thermoplastic resin sheet is a resin sheet obtained by kneading the above-mentioned transparent thermoplastic resin with the coloring agent described in the decorative layer. Those having a thickness of about 50 to 300 μm are used. The resin may be the same as or different from the base sheet.

The adhesive layer is formed using a heat-sensitive adhesive. As the adhesive, any of a heat fusion type using a thermoplastic resin and a thermosetting type using a thermosetting resin can be used. However, from the viewpoint that the bonding is completed in a short time, a heat fusion type (heat-sensitive fusion type adhesive) is preferable. The adhesive may be diluted with a solvent or without a solvent, or may be a liquid or a solid at room temperature, and may be used as appropriate. In the case of adhesives other than pressure-sensitive adhesives that exhibit tackiness,
The decorative layer can be made of only a single layer of the adhesive layer. If a coloring agent such as a pigment is added to the adhesive layer, it can be said that the entire layer is a decorative layer composed of a solid ink layer. Examples of the heat-sensitive adhesive include polyvinyl acetate, chlorinated polypropylene, vinyl chloride-vinyl acetate copolymer, acrylic resin, thermoplastic polyester resin, thermoplastic urethane resin, polyamide obtained by polycondensation of dimer acid and ethylenediamine. A conventionally known adhesive such as a resin can be used. As the thermosetting adhesive, a phenol resin, a urea resin, a diallyl phthalate resin, a thermosetting urethane resin, an epoxy resin, or the like can be used.

As a method of decorating a molded article, a processing method in which heat and stress are simultaneously applied to the decorative sheet is adopted. Specifically, there are an injection molding simultaneous decoration method and a vacuum molding decoration method, and these methods will be described in detail below.

The injection molding simultaneous decorating method is a well-known technique. In the injection molding, the decorative sheet inserted between the male and female molds is integrated with the injected resin to paint the surface of the molded product. Thus, all layers of the decorative sheet are adhered and integrated with the surface of the molded article to form a decorative layer. In order for the decorative sheet to favorably follow the shape of the molded product, the decorative sheet has the same shape as the internal shape of the female mold for injection molding prior to injection molding,
It is desirable to perform preforming by a vacuum forming method or a vacuum pressure forming method. As a preforming method, there is a method of mounting a decorative sheet preformed in another mold in advance in a female mold for injection molding or a method of preforming a decorative sheet directly with a female mold for injection molding. The latter method is often used. Of course, when the drawing of the molded product (mold) shape is shallow (the step of the unevenness is small), when the curvature of the unevenness is small, or when the formability (thermoplasticity) of the decorative sheet is sufficiently large, this preforming step is performed. The omission may be omitted, and the painting sheet may be formed to follow the mold shape by the heat and pressure of the injection resin.

FIG. 1 shows an example in which the decorative sheet is directly preformed by a female mold for injection molding. In the injection molding machine 10 of this embodiment, the female mold 20 has a structure in which a vacuum suction hole 21 and the like are provided so as to be applicable to vacuum suction molding, and is combined with the male mold 30 and molded by injection molding. A part of the shape of the molded article to be formed is shaped. Male type 3
0 is fixed to the fixed platen 31 and the tie bar 40 (4
Book) is also fixed. On the other hand, the female die 20 is fixed to a movable plate 22, and the movable plate 22 is slidably penetrated by a tie bar 40. When performing this preforming,
The decorative sheet S inserted between the male and female molds is fixed to the female mold 20 mounted on the movable platen 22 with the sheet clamp 50, and the hot platen 6
After the decorative sheet S is softened by heating at 0, the decorative sheet S is suction-contacted to the cavity surface in the female mold 20 through the vacuum suction holes 21 of the female mold 20. The upper end side of the decorative sheet S is nipped by the sheet chuck 70 and cut by the sheet cutter 80. As the sheet cutter 80, a blade, a heating wire, or the like is used. Thereafter, the decorative sheet S is cooled to complete the preliminary forming of the decorative sheet S. (Alternatively, the resin may be injected without waiting for the cooling of the decorative sheet S.) As the hot platen 60, a contact heating type in which the decorative sheet S is brought into close contact with the decorative sheet S and heated by heat conduction, Alternatively, any of radiant heat from a position distant from the decorative sheet and non-contact type heating by dielectric heating may be used.

When the decorative sheet is preliminarily formed by a separate vacuum forming method or vacuum pressure forming method, the decorative sheet is heated and softened with an infrared heater or the like using a mold having the same shape as the female mold for injection molding. The preforming step is completed by forming the inner shape of the mold by vacuum or vacuum pressure forming, releasing the mold, and attaching the formed decorative sheet to a predetermined portion of the female mold.

After the decorative sheet is preformed as shown in FIG. 1, the piston 91 is actuated by a fluid pressure cylinder 90 as shown in FIG. After being combined with the male mold 30 while sliding on the tie bar 40, the molds are clamped.
Is filled with the molded article forming resin P which has been heated and melted into a fluid state through the male gate 32 to perform injection molding. And injection resin P
Is solidified, the decorative sheet S and the resin molded product P 'are laminated, and then the male and female molds 20 and 30 are opened as shown in FIG. Out of the mold. The female mold 20 and the male mold 30 are formed of metal such as iron or ceramics.

The resin in the flow state injected from the male gate is a resin for injection molding, and is actually selected in accordance with required physical properties of the product, cost, and the like. Specifically, acrylonitrile-butadiene-styrene copolymer (ABS),
A resin such as polystyrene resin, acrylonitrile-styrene copolymer, polyvinyl chloride resin, polypropylene, polyethylene, polycarbonate, or acrylic resin, which is heated and melted and injected, and cooled to be solidified; Uncured liquid of two-component reaction-curable resin such as polyurethane resin comprising isocyanate crosslinking agent, epoxy resin using amine as curing agent, unsaturated polyester using isocyanate, organic sulfonate, benzoyl peroxide, etc. as curing agent There is a case where the composition is injected and is appropriately heated to be solidified by a chemical reaction.

The vacuum forming decoration method is also a known technique, in which a decorative sheet is opposed to or placed on the surface of an adhered molded article with an adhesive therebetween, and a pressure difference caused by vacuum suction from the adhered molded article is obtained. In this method, the decorative sheet is laminated and adhered to the surface of the adhered molded article, and all the layers of the decorative sheet are adhered and integrated with the surface of the adhered molded article to form a decorative layer. With this method, if necessary,
In addition to the pressure difference caused by the vacuum suction, air pressure molding or pressing of a rubber-like elastic film from the support side of the decorative sheet may be used together.

FIG. 4 shows an example of a case where decoration is performed using a vacuum press machine. In this apparatus, when the decorative sheet is pressed against the adhered molded article, the compression pressure of the rubber-like elastic body is used in addition to the air pressure, and the decoration sheet is heated through the rubber-like elastic film heated by the heater. It is characterized by uniform heating of the decorative sheet and stronger pressing force.

In the vacuum press 100 shown in FIG. 1, there is an upper chamber 102 which can be moved up and down by means of up and down operation means 101 such as a fluid pressure cylinder. There are 103. An infrared radiation heater 104 is disposed inside the upper chamber 102. The lower opening of the upper chamber 102 is entirely covered with a rubber-like elastic film 105. The rubber-like elastic film 105 is usually made of silicon rubber or the like. The upper surface of the lower chamber 103 is a table 107 having a plurality of exhaust holes 106. In addition, the upper chamber 102 and the lower chamber 103 have air supply ports 10 respectively.
8 and an exhaust port 109 so that the internal pressure of each can be adjusted independently.

The procedure of decoration is as follows. First, in a state where the upper chamber 102 moves upward and is separated from the lower chamber 103,
The adhered molded product B is placed on the mounting table 107, and the decorative sheet S is further arranged from above the adhered molded product B. At this time, the decorative layer side of the decorative sheet S faces the adhered molded article B.
When the adhesive is applied to the outer surface of the decorative sheet S or the adhered molded product B, it is applied at this stage. If the adhesive contains a solvent, it is dried at this stage.

Next, the upper chamber 102 is moved downward and pressed against the lower chamber 103 to seal the upper chamber 102 and the lower chamber 103. FIG. 4 shows this state. Next, lower room 10
3 and the inside of the upper chamber 102 is pressurized. Further, the decorative sheet S is heated and softened through the rubber-like elastic film 105 by using the infrared radiation type heater 104 so that the decorative sheet S can be formed. As a result, the decorative sheet S is the adhered molded product B
Along the outer surface of the upper chamber 102 and the lower chamber 103 due to the pressure difference and the contraction pressure of the rubber-like elastic film 105,
The decorative sheet S comes into close contact with the adhered molded product B.

Finally, the pressure in the lower chamber 103 is released and the pressure in the upper chamber 102 is released to bring both chambers to atmospheric pressure. The upper chamber 102 is moved upward to separate the upper chamber 102 and the lower chamber 103. Then, the molded article B to which the decorative sheet S is laminated and adhered is taken out.

[0029]

(Example 1) In this example, a decorative sheet S having a sectional structure as shown in FIG. 5 was manufactured. First, as the base sheet 1, a 125 μm-thick film obtained by adding an acrylic rubber and an aliphatic alcohol-based lubricant to polymethyl methacrylate
Was prepared. This acrylic resin sheet has a dynamic friction coefficient of 0.45 and a glass transition temperature of 73 ° C. Then, a comb-shaped metal blade was applied to the back surface of the base sheet 1 at room temperature of 20 ° C. to cut off a part thereof, thereby forming a hairline-shaped uneven pattern. The average width of the unevenness was 20 μm and the depth was 3 μm.

Subsequently, the decorative layer 2 having a total thickness of 4 μm was formed on the concave / convex pattern of the base material sheet 1 by gravure printing with two colors of single color silver. In the ink used, a 1: 1 weight ratio mixture of a vinyl chloride-vinyl acetate copolymer and an acrylic resin was used as a resin binder, and an aluminum scaly foil piece having an average particle diameter of 14 μm was used as a pigment. Further, on this decorative layer 2, an adhesive layer 3 made of a vinyl chloride-vinyl acetate copolymer was applied to a thickness of 4 μm.
m to obtain a decorative sheet.

Using the decorative sheet S having the above structure, FIGS.
A vehicle interior panel having a width of 40 mm and a length of 400 mm was molded by an injection molding machine as described in FIG. Specifically, the decorative sheet is inserted into the injection mold so that the adhesive layer side faces the male side, and the female mold cavity periphery of the decorative sheet is shaped like a mouth in plan view. After pressing and fixing on the female parting surface with a sheet clamp that has been made, the closed space surrounded by the female mold cavity and the decorative sheet is sealed from the outside, and heated to a sheet temperature of 110 ° C. with an infrared radiation type heater. Then, a vacuum was drawn from a vacuum suction hole formed in the female mold cavity, and the decorative sheet conformed to the shape of the mold. Thereafter, 240 ° C. heat-resistant ABS resin (95 ° C. heat-resistant temperature) melted at a mold temperature of 70 ° C. was injected into the cavity, filled and cooled and solidified to integrate the decorative sheet and the resin. As a result, it was possible to obtain a molded product having a design in which the hairline processing was performed on the inner surface.

Comparative Example 1 In Comparative Example 1, an acrylic resin sheet similar to that of Example 1 was prepared as a substrate sheet, and this sheet was wound around a metal heating drum having a surface temperature of 150 ° C. and from the front side. Was heated and softened by an infrared radiation heater, and then embossed on a metal embossing plate roll (roll temperature: 20 ° C.) to form an uneven pattern. The concavo-convex pattern at the end of the processing was the same as the decorative sheet of Example 1. Thereafter, a decorative layer and an adhesive layer were formed in the same manner as in Example 1 to produce a decorative sheet.
Then, in the same manner as in Example 1, when decoration was performed simultaneously with molding by an injection molding machine, the uneven surface was returned by the heat of the resin,
The effect of hairline processing hardly remained.

Example 2 In this example, a decorative sheet S having a sectional structure as shown in FIG. 6 was used. In this decorative sheet S, a hairline-shaped uneven pattern is formed in the same manner as the base sheet 1 used in Example 1, and a similar decorative layer 2 is formed on the uneven pattern. It is obtained by laminating colored thermoplastic resin sheets 5. As a colored thermoplastic resin sheet, 20 parts by weight of DOP was added as a plasticizer and 7 parts by weight of titanium white pigment was added.
A sheet of polyvinyl chloride of 0 μm was used. And
Using a two-part curable urethane resin adhesive (a two-part curable urethane resin adhesive obtained by adding 8 parts by weight of 1,6-hexamethylene diisocyanate to 100 parts by weight of acrylic polyol), a coating amount of 10 g / m ² . The base sheet 1 and the colored thermoplastic resin sheet 5 are bonded together to form a decorative sheet S
I got

Then, this decorative sheet S is formed into a plate-like molded product (thickness: 20 mm, length: 200 m) made of MDF (woody medium density fiberboard) by a vacuum press machine as described in FIG.
m, 100 mm wide) to produce a decorative board.
Specifically, an adhesive of a two-component curable urethane resin (an adhesive of a two-component curable urethane resin obtained by adding 8 parts by weight of 1,6-hexamethylene diisocyanate to 100 parts by weight of acrylic polyol) on a molded product. Coating at 35 g / m ² ,
After placing the decorative sheet S on the adhesive-coated surface of the molded article with the colored thermoplastic resin sheet 5 side facing, the decorative sheet S is heated to 110 ° C. with an infrared radiation type heater to soften it, The decorative sheet S was laminated and adhered to the surface of the molded product by vacuum suction from the molded product side.

Comparative Example 2 In Comparative Example 2, an acrylic resin sheet similar to that of Example 1 was prepared as a substrate sheet, and this sheet was wound around a metal heating drum having a surface temperature of 150 ° C., and from the front side. Was heated and softened by an infrared radiation heater, and then embossed on a metal embossing plate roll (roll temperature: 20 ° C.) to form an uneven pattern. The concavo-convex pattern at the end of the processing was the same as the decorative sheet of Example 2. Thereafter, a decorative layer was formed in the same manner as in Example 2, and a colored thermoplastic resin sheet was further laminated to produce a decorative sheet. Then, when vacuum forming decoration was performed in the same manner as in Example 2, the uneven surface was returned by the heat of the infrared radiation type heater, and the effect of the hairline processing hardly remained.

[0036]

Since the present invention is configured as described above, the following effects can be obtained. That is, according to the present invention, since the irregularities are formed on the back surface of the base sheet made of the transparent thermoplastic resin which is the interface with the decorative layer, when the decorative sheet is heated, heat is hardly transmitted to the irregular pattern. In addition, because the mechanical unevenness is mechanically formed by mechanical cutting, the residual stress that can be released by heating is not accumulated in the resin of the uneven pattern part, so that the unevenness returns during molding like the unevenness due to embossing There is no. Further, even if there is an uneven pattern on the internal interface of the decorative sheet, the decorative layer is present on the back surface, so that the uneven pattern can be clearly recognized from the outside by light reflection at the interface.

[Brief description of the drawings]

FIG. 1 is a partially cutaway view showing an initial stage when an injection molding simultaneous decorating method is performed by an injection molding machine.

FIG. 2 is a partially cutaway view showing a stage following FIG. 1;

FIG. 3 is a partially broken view showing a stage following FIG. 2;

FIG. 4 is an explanatory diagram in a case where a vacuum forming decoration method is performed by a vacuum press machine.

FIG. 5 is a sectional view showing a decorative sheet.

FIG. 6 is a sectional view showing another example of a decorative sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base sheet 2 Decorative layer 3 Adhesive layer 4 Adhesive 5 Colored thermoplastic resin sheet 10 Injection molding machine 20 Female mold 21 Suction hole 22 Movable board 30 Male mold 31 Fixed board 32 Gate 40 Tie bar 50 Sheet clamp 60 Heat Board 70 Sheet chuck 80 Sheet cutter 90 Fluid pressure cylinder 91 Piston 100 Vacuum press device 101 Vertical operation means 102 Upper chamber 103 Lower chamber 104 Heater 105 Elastic film 106 Exhaust hole 107 Mounting table 108 Air supply port 109 Exhaust port B Adhered molded product S Decorative sheet C Cavity P Molding resin P 'Resin molding

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B29K 101: 12 B29K 101: 12 B29L 9:00 B29L 9:00 F term (Reference) 4F100 AB10H AH02H AK01A AK01C AK01E AK15 AK15J AK22 AK22J AK25 AK74 AL01 AL05 AN02 AR00B AR00D AT00E BA02 BA03 BA04 BA05 BA07 BA10A BA10C BA10D BA10E CA13 CA19 DE02H EC032 EH362 EJ242 EJ321 EJ422 GB33 HB00B HB00A HB00B HB01B AF03 AG02 AG03 AH25 CA11 CB01 CB13 CB19 CN18 CP06 CQ06 4F206 AA13 AD05 AD09 AD20 AD24 AF01 AF03 AG02 AG03 AH25 JA03 JB14 JB19

Claims (5)

[Claims] 1. A decorative sheet comprising: a substrate sheet made of a transparent thermoplastic resin; a concave and convex pattern formed on the back surface of the substrate sheet by mechanical cutting; and a decorative layer formed on the concave and convex pattern. 2. The decorative sheet according to claim 1, wherein a colored thermoplastic resin sheet is further laminated on the decorative layer. 3. The decorative sheet according to claim 1, wherein an adhesive layer is further laminated on the decorative layer or the colored thermoplastic resin sheet. 4. After the decorative sheet according to claim 1 is inserted between the male and female molds of the injection molding so that the surface side of the decorative sheet faces the female mold, the two molds are engaged and closed. After that, the molten resin is injected and filled from the male mold into the cavity formed between the two molds, cooled and solidified to form a molded product, and the decorative sheet is laminated and adhered to the surface of the molded product. Characteristic method of decorating molded products. 5. The decorative sheet according to claim 1, wherein the decorative sheet is heated and softened, and at least a pressure difference between the front and the back of the decorative sheet by vacuum suction from the side of the molded article is applied to the decorative sheet. A method for decorating a molded article, comprising laminating and bonding to a molded article.