JPH1134247A - Injection molding simultaneous decorating sheet and injection molding simultaneous decorating method using the same - Google Patents

Abstract

(57) [Summary] [Object] A decorative sheet is laminated and integrated on the surface of a molded article simultaneously with injection molding to simultaneously perform surface decoration and antistatic. SOLUTION: A base sheet 1 made of a thermoplastic resin includes:
After the decorative sheet S provided with the decorative layer 3 is disposed between the female mold and the male mold, a resin in a flowing state is injected into the cavity to integrate the decorative sheet with the molded article. A decorative sheet having a configuration in which an antistatic layer 2 made of an ion-conductive amine-modified acrylic resin is provided on at least one of the front and back surfaces of the base sheet in the simultaneous injection-molding decorative sheet used in the simultaneous decoration method. In order to improve durability, adhesiveness, and the like, the ion-conductive amine-modified acrylic resin is preferably a cross-linked cured product with a thermo-crosslinkable monomer such as epoxy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface decorative sheet which is laminated and integrated on the surface of a molded article simultaneously with injection molding. More specifically, the present invention relates to a simultaneous decorative sheet for injection molding which prevents dust from being attached due to charging of the surface of a decorative molded article after molding, and a method for simultaneous decorative injection molding using the same.

[0002]

2. Description of the Related Art Surface-decorated resin molded articles have been widely used as interior materials for buildings, furniture, interior materials for vehicles such as automobiles and trains, containers for kitchens, boxes, and the like. As a method of manufacturing such a surface-decorated molded article, various injection molding simultaneous decoration methods in which a pattern or the like is formed on the outer surface of the molded article at the same time as the molded article are conventionally performed. For example, in Japanese Patent Publication No. 50-19132, a decorative sheet using a thermoplastic resin sheet as a base sheet is vacuum-formed using a female mold provided with air holes for vacuum forming. A method is disclosed in which a mold is closed, a molten thermoplastic resin is injected into a cavity of a mold, and a decorative sheet is laminated and integrated on an outer surface of a molded product. The simultaneous injection molding and decorating method of this embodiment is a method of combining vacuum molding and injection molding and laminating a decorative sheet on the surface of a molded resin, and can decorate a complicated curved surface. Further, as another embodiment, there is a method in which only a base sheet of a decorative sheet is peeled off by using a transfer type decorative sheet, and the transfer layer is transferred to a molding resin surface. Alternatively, there is a mode in which the vacuum molding is performed by another mold different from the injection molding die, or the vacuum molding is not performed.
As described above, the simultaneous injection molding and decorating method of decorating the surface of the resin molded product with the decorating sheet simultaneously with the molding of the resin molded product is excellent in productivity because the surface decoration treatment and the resin formation can be performed at the same time. Can be decorated, and by changing the pattern of the decorative sheet to be used, there is an advantage that various decorations can be handled.

[0003]

However, since the decorative sheet is made of a resin, it is easily charged, and the surface of the obtained decorative molded article is also easily charged during the work. For this reason, as a problem during the operation, if injection molding is performed while holding dirt or dust, it may appear as a foreign substance on the product surface. Further, in the decorative molded product, there is a problem that dirt and dust adhere to the surface to impair the aesthetic appearance, and that the adhered dirt is scratched if rubbed. Further, in an electric product, an electrostatic failure due to surface charging causes a malfunction of an electric circuit.

Accordingly, as an antistatic measure, an antistatic paint, for example, a paint comprising a water-soluble ionic conductive resin and a thermo-crosslinkable monomer disclosed in JP-A-4-220469,
A technique of applying the composition to the surface of a decorative molded article is conceivable. However, in the method using coating, as a problem during the work, the molded product usually has irregularities on its surface, and the coating causes liquid dripping, and the antistatic layer on the surface becomes uneven, and foreign matter such as dust at the time of coating. It is not preferable because of mixing, non-specularity of the coated surface, deformation of the molded product due to heat during drying, and the like. Further, in addition to the injection molding simultaneous decoration step, an antistatic step is required, and the number of steps is increased. In addition, since the antistatic layer of the obtained product is exposed on the surface, in addition to the durability of the antistatic layer itself, there is a problem that the antistatic layer lowers the inherent water resistance and chemical resistance of the resin molded product. is there.

There is also a technique using a decorative sheet having an antistatic property, such as a transfer sheet disclosed in JP-A-6-316024. If the decorating sheet itself has antistatic performance, both the decorating of the molded article surface and the antistatic property can be performed at the same time as molding without the need for a separate step. However, the transfer sheet type decorative sheet disclosed in JP-A-6-316024 has a configuration in which an antistatic layer, a decorative layer, and an adhesive layer are provided in this order on a base sheet. The antistatic layer is exposed on the surface of the molded product, and as in the case of the above-described coating, the performance of the obtained product is evaluated by the durability of the antistatic layer itself and the inherent water resistance and chemical resistance of the resin molded product by the antistatic layer. There is a problem that the properties and the like are reduced, and it is not satisfactory. In particular, the antistatic layer of the same publication is a layer composed of a crosslinking reaction product of a water-soluble ionic conductive resin and a thermally crosslinking monomer as in the above publication, and has a problem of water resistance and chemical resistance. .

The above-mentioned problems of water resistance and chemical resistance can be solved by dispersing carbon black in a resin as an antistatic layer. However, the antistatic layer is colored black and transparency cannot be obtained. Impairs the decorative effect. The problem with this carbon black is that although the transparency is slightly improved by using metal oxide fine particles such as zinc oxide and tin oxide instead of carbon black as the conductive particles, the color is slightly white or blue, Not satisfactory. In addition, since the resin containing the fine particles dispersed therein does not have conductivity, when the decorative sheet is stretched by decorating simultaneously with injection molding, there is also a problem that the intervals between the conductive particles are widened and the conductive performance is reduced. is there. As a transparent conductive layer, for example, a method in which a layer made of indium oxide (In ₂ O ₃ ) is provided as an antistatic layer can be considered. However, a baking step is required, and a resin sheet of a thermoplastic resin is required. Is difficult to provide. In addition, when the decorative sheet is stretched by decorating simultaneously with injection molding, cracks are formed in the antistatic layer, and there is also a problem that the conductive performance is lowered.

[0007]

In order to solve the above-mentioned problems, the injection-molded simultaneous decorative sheet of the present invention is a laminate type decorative sheet formed by applying a decorative layer to a base sheet made of a thermoplastic resin. The decorative sheet, comprising a female mold and a male mold, is disposed between the female mold and the male mold, and then a resin in a fluid state is injected into the cavity to thereby integrate with the molded product. And an antistatic layer made of an ion-conductive amine-modified acrylic resin was provided on at least one of the front and back surfaces. As a result, both the decoration of the surface of the three-dimensional molded article and the prevention of static electricity can be performed at the same time as molding without the need for a separate step such as post-coating. In addition, in the form in which the antistatic layer is provided on the back side of the base material sheet, that is, on the decorative layer side, the antistatic layer is not exposed on the surface of the decorative molded product, and since the surface becomes the base material sheet, it has water resistance. Antistatic performance can be provided without deteriorating chemical resistance or chemical resistance.
The antistatic layer made of the ion-conductive amine-modified acrylic resin is a cross-linked cured product obtained by cross-linking and curing the ion-conductive amine-modified acrylic resin with a heat-crosslinkable monomer, so that the ion-conductive amine-modified acrylic resin can be used. It is possible to improve the water resistance and the like of the resin.

In the simultaneous injection molding and decorating method of the present invention, the above-described simultaneous injection molding and decorating sheet is disposed between a female mold and a male mold, and then a resin in a fluid state is injected into a cavity. And a method of integrating the decorative sheet with a molded product.

Hereinafter, the injection-molded simultaneous decorative sheet of the present invention,
And a method of simultaneous decoration by injection molding using the same will be described in detail.

FIG. 1 is a cross-sectional view illustrating one embodiment of a simultaneous decorative sheet for injection molding according to the present invention. The decorative sheet for simultaneous injection molding S is a transparent substrate. An embodiment in which an antistatic layer 2, a decorative layer 3, and an adhesive layer 4 are laminated in this order on the back side of the sheet 1 is shown. The antistatic layer 2 may be provided on at least one of the front and back surfaces of the base sheet 1. Further, the side on which the decorative layer 3 is applied to the base sheet may be at least one side of the front and back surfaces of the base sheet 1, and may be the front side or both sides in addition to the back side as shown in FIG. In the decorative sheet of the present invention, the antistatic layer 2 is made of an ion-conductive amine-modified acrylic resin. In the configuration in which the antistatic layer is on the surface side of the base sheet, the antistatic layer is exposed to the ion-conductive amine-modified acrylic resin and the heat-crosslinkable monomer in order to be exposed on the surface of the decorated molded article. If it is composed of a crosslinked cured product of the above, the water resistance and durability of the antistatic layer can be improved. The adhesive layer 4 may be omitted when the decorative layer 3 or the antistatic layer 2 has a sufficient adhesive force with the injection resin. The surface side of the base sheet is the side exposed to the outside after the decorative sheet is laminated and bonded to the molded article. The side facing the molded product is called the back side.

(Base Sheet) The base sheet 1 is not particularly limited as long as it is a resin sheet made of a thermoplastic resin. However, when a decorative layer is laminated on the back surface side, it is necessary to have transparency. As the resin used, for example,
Polycarbonate resin, acrylic resin, ABS (acrylonitrile-butadiene-styrene copolymer), polyolefin such as polystyrene and polypropylene, polyamide resin, polyester resin such as polybutylene terephthalate, vinyl chloride resin, and olefin-based thermoplastic elastomer. . The base sheet is made of a resin layer composed of one or a mixture of two or more of these resins.
A single-layer sheet or a sheet in which two or more layers are laminated by coextrusion or the like is used. The base sheet may be colored transparent or colored opaque by kneading a coloring agent such as a pigment into the resin of the base sheet. As pigments, titanium white,
Inorganic pigments such as carbon black, ultramarine blue, red iron oxide, and graphite, and organic pigments or dyes such as quinacridone, isoindolinone, phthalocyanine blue, and aniline black are used. In addition, if necessary, extenders (fillers) such as calcium carbonate, silica (silicon dioxide), alumina (aluminum oxide), and barium sulfate may be added.
The thickness of the base sheet is appropriately selected depending on the application, but is usually about 12 to 500 μm, but is preferably in the range of 20 to 300 μm from the viewpoint of moldability. If the decorative sheet is too thin, it tends to tear or wrinkle when the decorative sheet is stretched. If it is too thick, the formability of the decorative sheet decreases and the cost increases.

In order to improve the light resistance (weather resistance) of the sheet simultaneously decorated with injection molding, an ultraviolet absorber, a light stabilizer and the like can be added to the base sheet. The addition may be made only with an ultraviolet absorber, but it is more effective to use it together with a light stabilizer. As the ultraviolet absorber, in addition to organic ultraviolet absorbers such as benzotriazole, benzophenone, and salicylic acid, inorganic materials such as zinc oxide, cerium oxide, and titanium oxide having a particle size of 0.2 μm or less are also used. be able to. As the light stabilizer, a hindered amine radical scavenger such as bis- (2,2,2,6,6-tetramethyl-4-piperidyl) sebacate can be used. The amount of addition of the ultraviolet absorber and the light stabilizer is usually about 0.5 to 10% by weight based on the total amount of the resin. If the amount is less than this, the effect of improving light resistance is not sufficiently obtained, and if the amount is more than this, coloring or bleeding of the surface particularly in the case of an organic substance is effective, even when a large amount is added. Is not preferred.

(Antistatic layer) The antistatic layer is made of an ion-conductive amine-modified acrylic resin. In order to improve the water resistance, it is composed of a cross-linked cured product obtained by adding a thermo-cross-linkable monomer to this and performing a cross-linking reaction. In particular, the antistatic layer provided on the surface side of the base sheet, to be exposed on the surface,
It is preferable to use a crosslinked cured product of an ion-conductive amine-modified acrylic resin and a thermally crosslinkable monomer. The antistatic layer is provided on at least one of the front and back surfaces of the base sheet. There are three forms of the front and back surfaces, only the front side, and only the back side of the base sheet. The antistatic effect of these forms decreases in the order of front and back surfaces> only the front surface side> only the back surface side. The form provided on the front side (only the front and back sides and the front side) has good effects but is exposed, so it is preferably used for applications where durability, water resistance, and chemical resistance are not so required. The form provided on the back side (only the front and back sides and only the back side) is less effective than the front side but is not exposed, so it is preferably used for applications where durability, water resistance and chemical resistance are not required. In particular, in the case of a laminated type simultaneous injection-molded decorative sheet as in the present invention, the form provided on the back side has an effect which cannot be obtained by the post-coating or transfer sheet described in the prior art. The thickness of this antistatic layer is about 1 to 10 μm.

The ionic conductive amine-modified acrylic resin includes a quaternized amine in the side chain, that is, a compound having a quaternary ammonium group and having a polymerizable vinyl group at a terminal, and a compound having a hydroxyl group in a side chain and a terminal having a hydroxyl group. A compound having a polymerizable vinyl group, and an acrylic resin comprising a copolymer obtained by copolymerizing a vinyl monomer or an oligomer thereof, such as an alkyl acrylate, which can be copolymerized with these compounds. . Examples of the compound having a quaternary ammonium base in the side chain and having a polymerizable vinyl group at the terminal include, for example,
And quaternized dimethylaminoethyl (meth) acrylate. Examples of the compound having a hydroxyl group in a side chain and a polymerizable vinyl group at a terminal include 2-hydroxyethyl (meth) acrylate.

The heat-crosslinkable monomer is a compound capable of crosslinking and curing an ion-conductive amine-modified acrylic resin by heat, and a compound capable of reacting with a hydroxyl group of the ion-conductive amine-modified acrylic resin by heat. Isocyanate compounds and epoxy compounds are exemplified. As these compounds, compounds having two or more isocyanate groups or epoxy groups are used in order to cause a cross-linking curing reaction. Since the isocyanate compound reacts with moisture in the air, the epoxy compound is easier to handle than the isocyanate compound. Examples of the isocyanate compound include polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, and tolylene diisocyanate. Examples of the epoxy compound include polyepoxides such as polyethylene glycol diglycidyl ether.

The heat crosslinkable monomer is preferably used in an amount of 10 to 50 parts by weight based on 100 parts by weight of the ion-conductive amine-modified acrylic resin. If the amount is less than 10 parts by weight, the crosslinking is too small, the adhesion, durability and water resistance are not improved, and the effect of blending the thermally crosslinkable monomer cannot be obtained. On the other hand, when the amount exceeds 50 parts by weight, the proportion of the thermally crosslinkable monomer becomes too large,
The conductivity is reduced, and the desired antistatic effect cannot be obtained. In addition, the crosslinking becomes too strong, and the stretchability of the decorative sheet decreases. Further, if the molding is performed forcibly, cracks will be formed in the antistatic layer and the layer in the vicinity thereof. Of course, in the configuration in which the antistatic layer is provided on the back side of the base sheet, the antistatic layer is not exposed, so that the antistatic layer does not require water resistance, chemical resistance, or durability. The conductive amine-modified acrylic resin does not have to be a crosslinked cured product using a thermally crosslinkable monomer. However, when it is necessary to improve adhesion, it is better to use a thermo-crosslinkable monomer.

(Decoration layer) The decoration layer is formed by a conventionally known method such as gravure printing, silk screen printing, offset printing, etc., a pattern ink layer obtained by printing a pattern or the like with a material, a metal such as aluminum or chromium by a known vacuum evaporation method. And a metal thin film layer formed on a part or the whole surface by a sputtering method or the like.
Patterns by these, such as marble and granite stone pattern, tile pattern, brick pattern, wood pattern, cloth pattern, letters,
It is arbitrary such as a geometric pattern and a solid surface. The ink for the picture ink layer comprises a vehicle such as a binder, a coloring agent such as a pigment or a dye, and various additives appropriately added thereto.
Binders include acrylic resin, chlorinated polyolefin resin, chlorinated polypropylene, vinyl acetate, vinyl chloride-vinyl acetate copolymer, polyester resin, thermoplastic resin such as cellulose resin, polyurethane resin, epoxy resin, etc. at room temperature or heat. A curable resin or the like is used in the form of a simple substance or a mixture of two or more of these resins. As a coloring agent such as a pigment or a dye, metal pigments such as titanium white, carbon black, red iron oxide, cobalt blue, graphite, phthalocyanine blue, isoindolinone, quinacridone, and aluminum powder, and pearlescent (pearl) pigments are used. Can be

(Adhesive Layer) As the adhesive layer, a conventionally known heat-sensitive adhesive can be used. For example, a resin such as a thermoplastic resin, a thermosetting resin, or an ionomer is used. Specific examples of the resin include, for example, ethyl cellulose, cellulose nitrate, cellulose acetate, ethyl hydroxyethyl cellulose, cellulose derivatives such as cellulose acetate propionate, polystyrene, poly α-
Styrene resin or styrene copolymer such as methyl styrene, acrylic resin such as poly (methyl) acrylate, ethyl (poly) methacrylate, butyl poly (meth) acrylate, polyvinyl chloride, polyvinyl acetate, vinyl chloride -Vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, vinyl polymer such as polyvinyl butyral, rosin, rosin modified maleic resin, rosin modified phenol resin, rosin ester resin such as polymerized rosin, polyisoprene rubber, polyisobutyl Rubber, styrene butadiene rubber, butadiene acrylonitrile rubber and other rubber-based resins, cumarone resin, vinyltoluene resin, polyamide resin, polychlorinated olefins, etc., natural or synthetic resins, various ionomers, and / or a mixture of two or more kinds thereof. Used.

[Injection Mold Simultaneous Decorating Method] Next, the injection molding simultaneous decorating method of the present invention using the injection molding simultaneous decorating sheet of the present invention as described above will be described. With this method,
As shown in the cross-sectional view of FIG. 2, a decorative product W having antistatic properties, in which the decorative sheet S is laminated and integrated on the surface of the molded product M, is obtained. The simultaneous injection-molding and decorating method of the present invention is a method using the above-described simultaneous injection-molding and decorating sheet as the decorative sheet, and can be applied to conventionally known various forms of simultaneous injection-molding and decorating methods.

First, in order for the decorative sheet to favorably follow the shape of the molded product, the decorative sheet is formed by vacuum forming (vacuum pressure air) so as to have the same shape as the cavity forming surface of the injection mold prior to injection molding. (Including molding). As a preforming method, a method of preforming a decorative sheet using an injection molding die also serving as a vacuum molding die, or a method of preliminarily preforming with a different molding die different from the injection molding die in advance, There is a method of mounting the decorated sheet on an injection mold. Usually, the former method is frequently used, and a female mold is usually used as an injection mold. Of course, whether the shape of the molded product (mold) is shallow and the unevenness is small,
Or, in the case of a curved shape with small irregularities, or in the case where the formability (thermoplasticity) of the decorative sheet is sufficiently large, this preforming is omitted, and the heat and pressure of the injection resin are used to form the decorative sheet into an injection mold. The molding may be performed by following the shape of the cavity forming surface.

In a mode in which the preforming of the decorative sheet is directly performed by an injection molding die, the injection molding die used has grooves and holes on its cavity forming surface and parting surface so that vacuum molding can be performed. A mold having a structure provided with a suction hole is used. To perform pre-molding by vacuum molding with an injection mold,
For example, after supplying a decorative sheet to an injection mold in an open state, the decorative sheet is heated and softened using a hot plate (heater) or the like, and then decorated through a suction hole provided on a cavity forming surface or the like. The air in the cavity sealed by the sheet is suctioned under vacuum to cause the decorative sheet to follow the cavity forming surface. The heating plate is in contact with the decorative sheet in close contact with it and is heated by heat conduction, or by radiant heat from a heating surface such as an infrared heater from a position away from the decorative sheet, or by dielectric heating Various types of heating means such as a non-contact type for heating are used. The heating and softening of the decorative sheet may be performed after the decorative sheet is supplied between the molds in the opened state, or may be started before the decorative sheet is supplied between the molds.

On the other hand, in the case where the decorative sheet is preliminarily formed by a separate vacuum forming method from a mold different from the injection mold, the cavity of the injection mold along which the decorative sheet is formed is provided in the mold. A vacuum mold having the same shape as the surface (or even a reverse uneven shape is possible) is used. Then, after the decorative sheet is heated and softened by the heating means such as the above-mentioned hot platen, the air in the mold sealed with the decorative sheet is suctioned under vacuum to form the inner shape of the mold, and then removed. The decorated and molded decorative sheet is mounted on a predetermined cavity forming surface of an injection mold.

Hereinafter, the injection molding simultaneous decorating method of the present invention will be described with reference to FIGS. According to these drawings, after inserting the decorative sheet between the injection molding dies composed of a pair of male and female molds in the mold open state so that the front side of the decorative sheet faces the cavity forming surface side, the molds are clamped. Then, a resin in a flowing state is injected and filled into the cavities formed by both molds, and after the resin is solidified, the mold is opened to obtain a molded product in which the decorative sheet is laminated and integrated on the surface of the molded product. The method of decorating simultaneously with injection molding will be described. In the present description, as one mode of the simultaneous injection molding decorating method of the present invention, an injection molding simultaneous decorating method in which a thermoplastic resin is used as an injection resin and the injection mold is also used as a preforming vacuum mold is used. take up.

First, FIG. 3 shows a state in which the decorative sheet S is supplied between the male and female dies in the mold open state. A female die 13 having a concave cavity forming surface is fixed to a die plate (movable platen) 11 that reciprocates in the left-right direction in the drawing.
A male die 14 having an injection hole is fixed to the other die plate (fixing plate) 12.
5 is located. Further, a sheet clamp 16 which is a frame-shaped frame body which presses the decorative sheet against the parting surface at the outer periphery thereof so as to seal the cavity of the female mold 13 is provided facing the parting surface. Seat clamp 16
Is always located between the molds, and is moved forward (to the left in the drawing) toward the female mold 13 by a drive mechanism such as an air cylinder during the period from the preforming of the decorative sheet to the opening of the decorative sheet. It is pressed and fixed on the parting surface of the female mold 13. The die plate 11 reciprocates due to the expansion and contraction of the hydraulic cylinder 17 on the rear surface, and at the time of mold clamping, the female mold 13 and the male mold 14 are brought into pressure contact with each other to unite. Although not shown, a suction hole connected to a vacuum source such as a vacuum pump is formed in the cavity forming surface of the female mold 13. Although not shown, a heating plate for heating and softening the decorative sheet reciprocates between the molds and a retracted position outside the mold.

In order to simultaneously decorate by injection molding using such an apparatus, first, as shown in FIG. 3, the decorative sheet S of the present invention having the above-described structure is placed in the female mold 13 when the mold is opened.
And between the male mold 14. Then, the decorative sheet is pressed against the parting surface of the female mold 13 by the sheet clamp 16.
Secure and seal the cavity. Next, a hot plate (not shown) is inserted between the molds, and the decorative sheet is heated and softened to form a vacuum, and the decorative sheet is preformed. As a result, the decorative sheet S is formed into a shape along the cavity forming surface of the female mold 13. The preforming is performed by suctioning air in a space formed between the cavity forming surface and the decorative sheet S from a suction hole (not shown) provided in the female mold 13, so that the front and back of the decorative sheet S are formed. This is performed by giving an air pressure difference to follow the shape of the cavity forming surface of the female mold 13. In addition,
In the preforming, in addition to the simple vacuum forming by vacuum suction from the suction hole of the female mold 13, a ventilation hole is also provided on the heating surface of the heating plate, and the heating surface and the decorative sheet are provided as a closed space. May be used in combination with the blowing of compressed air. After the hot plate is retracted out of the mold, the hydraulic cylinder 1
7 moves the piston (ram) 18 rightward in the drawing,
The female mold 13 in which the decorative sheet S is kept along the cavity forming surface by preforming is pressed into contact with and engaged with the male mold 14, and is united to perform mold clamping. Then, the resin P heated and melted from the injection nozzle 15 is injected into the cavity formed by the male and female dies through the male gate (gate), filled, and subjected to injection molding. FIG. 4 shows a state in which the resin in the flowing state is being injected into the cavity from the injection nozzle 15 after the mold clamping. Then, after the resin made of the thermoplastic resin is solidified by cooling, the female mold 13 is moved to the left in the drawing, separated from the male mold, opened, and the molded product is taken out of the mold, as shown in FIG. By decorating and integrating such a decorative sheet S on the surface of the molded article M, a decorative molded article W composed of the molded article M whose surface is decorated and which is antistatic can be obtained.

The injection molding simultaneous decorating method of the present invention comprises:
This is a method in which a decorative sheet is laminated on the surface of a molded article at the same time as injection molding of the molded article. A typical injection molding method that can be applied is an injection molding method using a hot-melted thermoplastic resin as a resin in a fluid state. Alternatively, an injection molding method such as a reactive injection molding method (RIM molding method) in which an uncured liquid reaction-curable resin (raw material) is injected and then cured by a chemical reaction may be used. In the reactive injection molding method, a resin in a fluid state is not necessarily a resin melted by heating.

[Molding resin] The resin used in the injection molding is not particularly limited.
Known injection molding resins can be used, for example, polyvinyl chloride, polystyrene, acrylonitrile-styrene copolymer, ABS resin, acrylic resin, polycarbonate,
Thermoplastic resins such as polyethylene and polypropylene can be used. In the case of reaction injection molding, the (reaction-curable) resin is a polyurethane resin using an isocyanate as a curing agent, or a resin liquid such as an unsaturated polyester using an isocyanate, an organic sulfonate, benzoyl peroxide or the like as a curing agent. Can be used.

[Others] The term "decoration" as used in the present invention means not only a pattern, a character, a figure, etc. but also a pattern that is not visible, or a hard coating film. And providing a functional layer such as a conductive layer. As an example of a pattern that is not visible, a pattern printed with a fluorescent ink that is colorless and transparent to visible light and emits fluorescence by irradiation with ultraviolet light, or the like is used. In addition, the term “injection molding” as used in the present invention refers to not only injection of “thermoplastic thermoplastic resin” used in general injection molding, but also “injection of thermosetting or two-component reaction-curing resin in a molten state at room temperature. Injecting a “cured product” is also included. In addition, as a matter of course, the sheet simultaneously decorated with injection molding may be a single sheet or a continuous strip.

[0029]

The present invention will be further described below with reference to examples and comparative examples.

(Example) As a simultaneous decorative sheet for injection molding, on the back side of a transparent acrylic resin sheet having a thickness of 125 μm, ethylene glycol was used as a thermally crosslinkable monomer with respect to 100 parts by weight of an ionic conductive amine-modified acrylic resin. A coating solution containing 25 parts by weight of diglycidyl ether and having a solid content of 20 wt% by dilution with a solvent is gravure-printed, dried by heating, and formed of a crosslinked cured product having an application amount of 1 g / m ² (solid content). An antistatic layer was formed. Next, as a decorative layer on the antistatic layer, a pigment composed of titanium white, red iron oxide, and graphite was added to a binder composed of a mixture of an acrylic resin and a vinyl chloride-vinyl acetate copolymer in a weight ratio of 1: 1. The decorative pattern was formed by gravure printing of the wood pattern with the ink thus obtained. Next, as an adhesive layer on the decorative layer forming surface side, an adhesive made of a vinyl chloride-vinyl acetate copolymer is gravure-printed on the entire surface, and the coated amount after drying is 2 g / m 2.
The adhesive layer of No. ² was formed to obtain a simultaneous decorative sheet for injection molding of the present invention.

The above-mentioned decorative sheet is bonded by using a device as outlined in FIG. 3 and FIG. 4 by a simultaneous softening and decorating method in a form with heat softening of the decorative sheet and preforming by an injection mold. The front side, on which the agent layer was not applied, was inserted between the male and female dies so as to face the cavity forming side of the injection mold, preliminarily molded, and adhered to the surface of the injection molded article simultaneously with the injection molding. Preliminary molding of the decorative sheet was performed by vacuum molding using a female mold for injection molding. The conditions were heating at 150 ° C. for 5 seconds, evacuation was started, and vacuum molding was performed to form a female mold cavity. In addition, ABS resin was used as the injection resin, and molding was performed under the molding conditions of a resin temperature of 230 ° C and a mold temperature of 40 ° C.

(Comparative Example 1) A decorative layer and an adhesive layer were formed in the same manner as in the example except that the antistatic layer was not formed on the base sheet in the example. . Then, a molded product was obtained by the simultaneous injection molding and decorating method under the same conditions as in the example.

(Comparative Example 2) The amount of the thermally crosslinkable monomer used in the antistatic layer was changed from 25 parts by weight to 10
Except that the amount was changed to 0 parts by weight, a decorative layer and an adhesive layer were formed in the same manner as in the example to obtain a simultaneous decorative sheet for injection molding. And
A molded article was obtained by the simultaneous injection molding and decorating method under the same conditions as in the example.

Table 1 shows the performance evaluation results of the decorative resin molded articles obtained in the above Examples and Comparative Examples. Each evaluation item was evaluated as follows. Moldability: Whether or not the decorative sheet at the time of injection molding can be stretched and conformed to the surface shape of the molded article at the time of preforming, and the occurrence of cracks in the decorative layer and the like were evaluated by visually observing the decorative sheet after preforming. . Dust Adhesion: The molded product integrated with the injection-molded simultaneous decorating sheet and the surface of which had been decorated was allowed to stand in a room for one month, and the amount of dust adhered to the surface of the molded product was visually determined. Ash adhesion: Molded product integrated with the injection-molded simultaneous decorative sheet and decorated on the surface is subjected to room temperature (22 ° C.) and humidity of 40% R.
Under the environment of H, after the tobacco ash falls on the surface of the molded article,
The molded product was inverted and the amount of ash remaining on the molded product surface was visually determined.

[0035]

[Table 1]

As shown in Table 1, in the examples, cracks did not occur in the decorative layer at the time of preforming, the moldability was good, and no adhesion of dust or ash was observed. However, in Comparative Example 1, although the moldability was good, dust and ash adhered due to the absence of the antistatic layer, and the appearance of the molded product was remarkably inferior to the examples. In Comparative Example 2, although there was no adhesion of dust and ash, the stretchability of the antistatic layer was poor due to the large mixing ratio of the thermo-crosslinkable monomer in the antistatic layer, and the decorative layer adjacent to the antistatic layer Cracks occurred.

[0037]

According to the decorative sheet for simultaneous injection molding of the present invention, no separate step such as post-coating is required, and simultaneously with molding of the molded article, the decorative sheet is laminated along the uneven shape of the molded article surface. It is possible to perform both surface decoration and antistatic of a three-dimensional molded product at a time. In the case where the antistatic layer is provided on the back side of the base material sheet, the antistatic layer is not exposed on the surface of the decorative molded product, and the surface becomes the base material sheet. Without doing so, antistatic performance can be imparted. In addition, the antistatic layer may be a crosslinked cured product obtained by crosslinking and curing an ion-conductive amine-modified acrylic resin with a thermally crosslinkable monomer, thereby improving the water resistance and the like of the antistatic layer. According to the simultaneous injection molding decorating method of the present invention, it is possible to efficiently produce a surface-decorated and antistatic molded article.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a simultaneous decorative sheet for injection molding of the present invention.

FIG. 2 is a sectional view showing an example of a molded product obtained by the simultaneous injection molding and decorating method of the present invention.

FIG. 3 is a conceptual explanatory view of one embodiment of the simultaneous injection molding decorating method of the present invention: a state in which a decorative sheet is supplied between dies.

FIG. 4: Same: The state during injection of resin after mold clamping.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base sheet 2 Antistatic layer 3 Decorative layer (picture ink layer, metal thin film layer, etc.) 4 Adhesive layer 11 Die plate (movable plate) 12 Die plate (fixed plate) 13 Female type 14 Male type 15 Injection nozzle 16 Sheet Clamp 17 Hydraulic cylinder 18 Piston (ram) M Molded product P Resin S Injection molding simultaneous decorative sheet W Decorated molded product

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B44C 1/165 B44C 1/165 // C09K 3/16 106 C09K 3/16 106E

Claims (3)

[Claims] 1. A decorative sheet formed by applying a decorative layer to a base sheet made of a thermoplastic resin is disposed between a female mold and a male mold, and then a resin in a fluid state is injected into a cavity. In the simultaneous injection-molded decorative sheet in which the decorative sheet is integrated with the molded article, the base sheet is provided with an antistatic layer made of an ion-conductive amine-modified acrylic resin on at least one of the front and back surfaces of the base sheet. Simultaneous decorative sheet. 2. The simultaneous decorative sheet for injection molding according to claim 1, wherein said antistatic layer comprises a cross-linked cured product of an ion-conductive amine-modified acrylic resin and a thermo-crosslinkable monomer. 3. The decorative sheet according to claim 1 or 2, wherein the decorative sheet is placed between a female die and a male die, and then a resin in a fluid state is injected into a cavity. Injection molding simultaneous decoration method that integrates with a molded product.