JP2003311898A - Sheet for decorative molding and decorative molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent both of dimensional shrinkage due to heat at the time of thermoforming of a sheet and lowering of mirror surface properties forming a sheet surface into satin-like unevenness, in a sheet for decorative molding comprising a first layer formed from a thermoplastic resin sheet and a second layer formed from a polyolefin resin. <P>SOLUTION: In the sheet S for decorative molding having the first layer 1 formed from the transparent thermoplastic resin and the second layer 2 formed from the polyolefinic resin, the second layer is formed as multilayered constitution of at least two or more layers, no filler is added to the side facing to the first layer, and a filler is added to the other layer not facing to the first layer. The second layer of the multilayered constitution may be laminated by a multilayer co-extrusion method. A pattern layer 3 and an adhesive layer 4 may be laminated to the back surface of the first layer in this order by printing or the like. If this sheet for decorative molding is laminated to the surface of the resin composition, the decorative molded product is obtained. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative molding sheet used for surface decoration of various articles and a decorative molded article using the same. In particular, it relates to a decorative forming sheet and a decorative molded product using a polyolefin resin.

[0002]

2. Description of the Related Art Conventionally, a decorative molded product obtained by decorating the surface of a resin molded product has been used for various purposes. For example, in the simultaneous injection molding decoration method disclosed in Japanese Patent Publication No. 50-19132, Japanese Patent Publication No. 43-27488, etc., after a decorative molding sheet is placed between male and female molds for injection molding, a molten resin is formed. By injection-filling the resin into the cavity and solidifying the resin, and at the same time as molding the resin molded product, the decorative molding sheet is adhesively laminated on the surface to obtain an integrated decorative molded product.

Further, as the resin material used for the resin molded product, generally, ABS resin, acrylic resin, polycarbonate resin and the like are often used. Therefore, the decorative molding sheet is on the back surface side which is the resin molded product side. Base material sheet (back side sheet)
In addition, an ABS resin sheet or the like has often been used in consideration of adhesion with these resins. Recently, it has been strongly desired to use an inexpensive polyolefin resin such as polypropylene as a resin material for a resin molded product. Therefore, various decorative molding sheets using a polyolefin resin as a base sheet have been tried. Has been. On the other hand, when a feeling of coating is required as a design of a decorative molded product, a transparent resin sheet using an acrylic resin, which has excellent transparency and also has good moldability, weather resistance, scratch resistance, etc. It is often used for the side base sheet (top sheet). Further, in order to enable high-quality expression, usually, a pattern layer is formed by printing between the top sheet (first layer) and the back sheet (second layer), and the top sheet and the back sheet are Has been laminated with an adhesive.

Therefore, for example, a pattern layer is formed by printing on the back surface of a transparent top sheet (first layer) made of an acrylic resin in order from the front side, and then this is colored with polypropylene or the like via an adhesive layer. A decorative molding sheet or the like is formed by adhesively laminating a polyolefin resin sheet (second layer) colored by addition of an agent.

[0005]

However, as described above, in the decorative molding sheet having a structure in which a single layer polyolefin resin sheet is simply laminated on the back side of the acrylic resin top sheet, the second layer is used. If the polyolefin resin sheet of No. 1 is composed of a resin component and a pigment fraction of a colorant, the dimensional shrinkage of the decorative molding sheet after vacuum molding will be large, and the dimensions will not match the mold during the subsequent injection molding. ,
Since it is forcibly corrected to the shape of the mold by the injection resin, the problem of defective molding such as wrinkles occurs in the decorative molding sheet laminated on the surface of the molded product. This dimensional shrinkage causes the total thickness of the decorative molding sheet to become thick (for example, 0.3 mm or more) in terms of the size of the decorative molded product, and the preforming of the decorative molding sheet is different from the injection molding die. In the simultaneous injection-molding decoration (form of off-line pre-molding) in which the molded sheet is mounted on the injection-molding mold after performing the above-mentioned step, it was particularly severe. For this reason, if the dimensional shrinkage is too large, the decorative molding sheet after preforming may not be mounted in the injection mold. Further, if the dimensional shrinkage is to be prevented by adding a filler such as talc to the polyolefin resin sheet, heat during vacuum forming (usually about 160 to 180 ° C. is added).
Then, the surface of the decorative molding sheet becomes uneven such as an orange skin, and another problem of defective molding occurs that the specularity of the surface of the molded product is lost.

[0006] That is, an object of the present invention is to prevent a molding defect in which the surface of the sheet becomes uneven when a decorative molding sheet using a polyolefin resin sheet is molded on the back side and laminated and decorated. , And to provide a decorative forming sheet that realizes this. Another object of the present invention is to provide a decorative molded product decorated with such a decorative molding sheet.

[0007]

In order to solve the above-mentioned problems, the decorative molding sheet of the present invention comprises, in order from the front side, a first layer made of a transparent thermoplastic resin and a first layer made of a polyolefin resin. In a decorative molding sheet in which two layers are laminated in this order, the second layer has a multi-layered structure of at least two layers, of which the side facing the first layer has no filler added and the other layers A filler is added to the composition.

With this structure, the second layer made of the polyolefin resin has the filler added, but the portion closest to the surface side has no filler added.
First, the filler prevents dimensional shrinkage during sheet molding. For this reason, it is possible to prevent the occurrence of molding defects such as wrinkles in the decorative molding sheet laminated on the surface of the molded product by simultaneous injection molding and decoration. Further, the decorative molding sheet has a large thickness (for example, 0.
3 mm or more or 0.4 mm or more), the pre-formed decoration is performed by simultaneous injection-molding decoration in the form of offline pre-molding, which is pre-molded by a mold different from the injection mold that is the preferred form. It is also possible to prevent molding defects that cannot be fitted to the injection mold because the dimensions of the molding sheet do not match the dimensions of the injection mold. Moreover, it is possible to prevent deterioration of the specularity of the surface of the molded product, which is conventionally caused by the hot molding of the sheet, which is caused by the addition of the filler.

Further, the decorative molding sheet of the present invention has a constitution in which the second layer is further formed by the multi-layer coextrusion method in the decorative molding sheet having the above constitution.

With such a structure, there is no increase in the number of steps of preparing and laminating the second layer of the multilayer structure as a resin sheet for each layer alone, and it is possible to prevent the cost from increasing.
In addition, interlayer adhesion within the second layer can be obtained more reliably.

Further, the decorative molding sheet of the present invention is the decorative molding sheet of any one of the above constitutions, further comprising a pattern layer laminated on the back surface of the first layer.

With such a structure, a high design can be achieved by the pattern layer.

Further, the decorative molding sheet of the present invention is the decorative molding sheet of any one of the above constitutions, further comprising a first layer and a second layer laminated with an adhesive layer interposed therebetween. It was configured.

With such a constitution, the first layer and the second layer can be laminated with good adhesiveness by the adhesive layer.

In the decorative molded product of the present invention, the decorative molded sheet having any one of the above-mentioned constitutions is formed on the surface of the resin molded product made of a polyolefin resin, and the second layer side of the decorative molded sheet is on the resin molded product side. It was configured to be laminated toward.

As described above, the decorative molding sheet having the above-mentioned specific structure is formed on the resin molded product of the polyolefin resin.
Adhesion between the polyolefin resin molded product and the decorative molding sheet is good due to the laminated structure, and wrinkles and deterioration of the specularity of the surface due to defective molding at the decorative molding sheet part. It is possible to enjoy the respective effects obtained by the above-mentioned decorative molding sheet, such as preventing the above. The decorative molding sheet has a large thickness, and is a decorative molded product suitable for simultaneous injection-molding decoration in the offline preforming mode.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

Outline : First, some of the constitutional examples of the decorative molding sheet of the present invention are illustrated in the sectional view of FIG. Figure 1
In the decorative molding sheet S shown in (A), a first layer 1 made of a transparent thermoplastic resin, a pattern layer 3, an adhesive layer 4, and a second layer 2 made of a polyolefin resin are laminated in this order from the front side. Moreover, the second layer 2 has a multi-layered structure including a front layer 2A and a back layer 2B. In the present invention, the surface layer 2A, which is the layer facing the first layer of the second layer, has no filler added, and the other back layer 2B is the layer.
Is a layer with a filler added. The respective layers of the second layer 2 are preferably laminated by a multi-layer (two layers in this case) coextrusion method from the viewpoints of avoiding an increase in the bonding step and the adhesion between the layers. The pattern layer 3 and the adhesive layer 4 may be omitted respectively, but it is preferable to provide them in terms of designability, interlayer adhesion, etc. Usually, both layers are provided.

Next, the decorative molding sheet S shown in FIG. 1 (B) has a surface layer 2A, a center layer 2C, and a center layer 2C as a multilayer structure of the second layer 2 in addition to the structure of FIG. 1 (A). This is an example of a form having a three-layer structure of the back layer 2B. Among these, the layer without a filler is the front layer 2A and the back layer 2B, and the layer with a filler is the central layer 2C.

Next, the structure of the decorative molded product of the present invention is shown in FIG.
The cross-sectional view of FIG. The decorative molded product P shown in FIG. 2 has the same structure as that shown in FIG.
The decorative molded sheet S having the structure as illustrated in the cross-sectional view is a decorative molded product having a structure in which the second layer side is laminated so that the second layer side is the resin molded product side. Although the illustration of the layer structure of the portion of the decorative molding sheet S is omitted in the same drawing, that portion is the same as the decorative molding sheet S illustrated in the cross-sectional view of FIG. 1.

Decorative molding sheet : First, the decorative molding sheet will be described in order from the first layer on the front surface side.

[First Layer] The first layer 1 is composed of a transparent thermoplastic resin. By making the first layer transparent, a feeling of painting,
Alternatively, design characteristics such as surface gloss can be imparted. In addition, moldability (vacuum moldability) can be obtained by using a thermoplastic resin. In addition, although the first layer is transparent, it is usually colorless transparent, but it may be colored transparent by adding a coloring agent as needed. Alternatively, it may be semitransparent. In addition, as the colorant, known ones such as those listed in the later-described pattern layer can be used.

The transparent thermoplastic resin is basically not particularly limited as long as it is a transparent thermoplastic resin.
Further, when the pattern layer is printed on the resin sheet as the first layer, a resin sheet having printability may be used. Examples of such a thermoplastic resin include polymethyl (meth) acrylate, polybutyl (meth) acrylate, methyl (meth) acrylate-butyl (meth) acrylate copolymer, methyl (meth) acrylate-styrene copolymer, etc. , (Meth) acrylate means acrylate or methacrylate. The same applies below. ] Acrylic resin, polyethylene, polypropylene, polymethylpentene, polybutene, ionomer, ethylene-propylene copolymer, ethylene-propylene-butene copolymer, polyolefin resin such as olefin thermoplastic elastomer, polybutylene terephthalate, polyester system Examples thereof include thermoplastic elastomers, polyester resins such as completely amorphous polyester, polycarbonate resins, polystyrene resins, and vinyl chloride resins.

Among them, acrylic resin is one of the preferable resins as the transparent thermoplastic resin. This is because the acrylic resin has excellent transparency, which can impart a high-grade design property such as a coating feeling or surface gloss. Further, the acrylic resin has an advantage that surface properties such as weather resistance and scratch resistance can be improved as compared with the case of using a polyolefin resin or the like.

The first layer is prepared as a resin sheet (top sheet), and usually, after a picture layer is printed on the back side of the resin sheet, an adhesive is used to laminate the second layer with a desired layer to obtain a desired layer. This is a decorative molding sheet. The thickness of the resin sheet (film) as the first layer may be appropriately set from the viewpoints of cost, moldability, printability, designability (painting feeling), etc., but is usually about 30 to 200 μm. good. Above all 1
It is generally around 00 μm.

In the first layer, if necessary, a lubricant such as polyethylene wax or paraffin wax, silica, spherical α-alumina, or scaly is appropriately used in view of the surface side of the decorative molding sheet. Antifriction agent consisting of particles such as α-alumina, filler consisting of particles of calcium carbonate, barium sulfate, aluminum oxide, benzotriazole type,
Various additives such as a benzophenone-based or cerium oxide-based ultraviolet absorber or a light stabilizer such as a hindered amine-based radical scavenger may be added for the purpose of adjusting physical properties. However, it is added within the range in which the first layer does not become opaque.

[Second Layer] The second layer 2 is composed of a polyolefin resin. Moreover, the second layer 2 has a multi-layered structure of at least two layers, in which the filler layer is not added to the layer facing the first layer, that is, the front layer, and the filler is added to the other layers. And In addition, in the other layers, the filler is added to at least one layer (preferably a layer mainly in terms of thickness), but it is not necessary to add the filler to all of the other layers [ See FIG. 1B]. In other words, at least the layer on the front side is a layer with no filler added. As a result, by adding a filler as the entire second layer, it is possible to prevent dimensional shrinkage due to heat at the time of forming a sheet of a decorative forming sheet, and to add to the surface of the sheet after forming the sheet, which is conventionally caused by adding a filler. It is also possible to prevent a decrease in specularity.

As the above-mentioned polyolefin resin, a resin suitable for the application may be selected appropriately. For example, as the polyolefin resin, polyethylene, polypropylene, polymethylpentene, polybutene, ionomer,
An ethylene-propylene copolymer, an ethylene-propylene-butene copolymer, an olefin-based thermoplastic elastomer or the like can be used. Also, elastomers and the like may be mixed in consideration of elongation characteristics and the like.

As the filler to be added to the second layer, known fillers can be appropriately used. Examples of the filler include aluminum oxide,
Calcium carbonate, calcium sulfate, barium sulfate, talc, silica, lithium aluminum silicate, silicone carbide and the like can be used. The addition of the filler has the effect of preventing dimensional shrinkage at the time of forming the sheet, and the effect of widening the appropriate temperature range at the time of forming the sheet and facilitating stable sheet forming.

By the way, the second layer is usually mainly composed of 50% of the total thickness of the decorative molding sheet in view of mechanical strength required for the decorative molding sheet and moldability. Although it is above, it may be less than 50%). Therefore, the thickness of the second layer is a total thickness of the second layer and is usually about 0.1 to 0.5 mm. However, considering the post-processes (sheet forming, sheet lamination), the thickness of 0.3 to 0. It is preferably about 6 mm. In the second layer, the ratio of the thickness of the front layer to which no filler is added is about 1/20 to 3/10 with respect to the total thickness of the second layer, though it depends on the resin and other conditions. Good results were obtained for both dimensional shrinkage and loss of specularity.

In the second layer, the decorative forming sheet is provided with a concealing property for the adherend, a decoration by coloring,
A colorant or the like may be added for producing a background color of the pattern layer. As the colorant, known colorants listed in the later-described pattern layer can be used. For example, in terms of hiding power, in addition to white pigments such as titanium white, zinc white, and diantimony trioxide, black pigments such as carbon black and iron black are used within a range that does not hinder the color development of the picture layer. The colorant may be added at least in the layer facing the first layer, as in the case of the above-mentioned filler, particularly when it is a pigment rather than a dye, but it is usually added. Not doing so is preferable for the same reason as in the case of using the filler. Therefore, for example, when the second layer has a two-layer structure of a front layer and a back layer, the coloring agent and the filler are not added to the front layer, and the coloring agent and the filler are added to the back layer.
In the case of a three-layer structure, for example, a filler is added to the central layer and curl is less likely to occur as a laminated sheet. preferable. In that case, it is preferable that the back layer has the same thickness as the surface layer.

To form the second layer in a multi-layer structure, resin sheets for the respective layers may be laminated, but each layer is formed by a multi-layer coextrusion method such as two layers or three layers. Laminating at the same time is preferable because the adhesion between the layers can be improved and an additional laminating step is unnecessary.

[Picture Layer] The picture layer 3 is a layer for expressing a picture, and even if the picture layer is not provided, appropriate designability (a solid pattern or the like due to the colored resin sheet itself) can be imparted, but more designability is provided. Usually provided to improve. The pattern layer is usually formed by a printing method on the back surface side of the resin sheet as the first layer. The printing may be a known method such as gravure printing, letterpress printing, silk screen printing, offset printing, inkjet printing and the like. In the case of a solid pattern on the entire surface, a known coating method such as roll coating may be used. The ink (or coating liquid) to be used may be appropriately selected depending on the resin of the first layer.

For example, when the resin for the first layer is an acrylic resin, an ink (or a coating liquid) whose binder resin is an acrylic resin is one of the desirable inks. As the binder resin, chlorinated polyethylene,
Chlorinated polyolefin resin such as chlorinated polypropylene,
Thermoplastic resins such as polyester resins, urethane resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, cellulosic resins, etc., or thermosetting resins such as urethane resins, epoxy resins, etc. may be used alone or as a mixture. Used as. In addition, the colorant of the ink is not particularly limited, and examples thereof include titanium white, carbon black, red pattern,
Inorganic pigments such as cobalt blue and yellow lead, organic pigments such as phthalocyanine blue, isoindolinone and quinacridone,
A known pigment such as a metallic pigment such as aluminum powder, a pearlescent pigment such as titanium dioxide-coated mica powder, or a dye can be used. The pattern of the pattern layer may be, for example, a wood pattern, a stone pattern, a grain pattern, a tile pattern, a brickwork pattern, a texture pattern, a leather pattern, letters, symbols, figures, or a geometric pattern, depending on the application. Academic patterns, full-scale solid, etc. are used alone or in combination.

Examples of the acrylic resin include polymethyl (meth) acrylate, polybutyl (meth) acrylate, methyl (meth) acrylate-butyl (meth) acrylate copolymer, methyl (meth) acrylate-styrene copolymer. Such as acrylic resin, or methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, cyclohexyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate,
2-hydroxy-3-phenoxypropyl (meth) acrylate having a hydroxyl group in the molecule (meth)
An acrylic resin such as an acrylic polyol obtained by copolymerizing an acrylic ester is used alone or in combination of two or more. When acrylic polyol is used,
2,4-tolylene diisocyanate, if necessary,
You may crosslink by adding isocyanates, such as 1,6-hexamethylene diisocyanate. The (meth) acrylate means acrylate or methacrylate.

The acrylic resin is also preferably used as a mixed resin with a vinyl chloride-vinyl acetate copolymer in terms of adhesion. The vinyl chloride-vinyl acetate copolymer usually has a vinyl acetate content of about 5 to 20% by mass,
Those having an average degree of polymerization of about 350 to 900 are used. Further, vinyl chloride-vinyl acetate copolymer, if necessary,
Further, those obtained by copolymerizing carboxylic acids such as maleic acid, fumaric acid and (meth) acrylic acid may be used. Further, the mixing ratio of the acrylic resin and the vinyl chloride-vinyl acetate copolymer is as follows: acrylic resin / vinyl chloride-vinyl acetate copolymer =
Used at about 1/9 to 9/1 (mass ratio).

The pattern layer may be a functional layer such as a conductor layer or a magnetic layer, in addition to a layer for decorative purposes such as a grain pattern. For example, in the conductor layer, as a material to be contained in the binder of the specific resin, a conductive powder such as silver powder is dispersed instead of the colorant. In the case of a magnetic layer, iron oxide (γ-Fe ₂ O ₃ ) is used instead of the colorant.
Disperse the magnetic powder consisting of the above. That is, the decoration in the present invention also includes providing a functional layer or a pattern which cannot be visually observed with the pattern layer. In addition,
Examples of invisible patterns include a pattern printed with a fluorescent ink that is transparent to visible light and emits fluorescence when irradiated with ultraviolet rays, a barcode printed with an infrared absorbing ink, and the like.

[Adhesive Layer] The adhesive layer 4 takes into consideration the adhesiveness to the first layer, the second layer, or the pattern layer in contact with the layer,
Depending on the resin or the like used in these layers, a known adhesive may be appropriately selected and used. For example, when the thermoplastic resin of the first layer is an acrylic resin and the polyolefin resin of the second layer is a polypropylene resin, a curable urethane resin such as a polyester urethane resin gives preferable results. In addition, examples of the resin of the adhesive layer include thermoplastic resins such as vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, thermoplastic polyester resin, polyamide resin, ionomer, chlorinated polyolefin resin, and thermoplastic urethane resin. Alternatively, a curable resin such as a phenol resin or an epoxy resin, or a rubber resin is used alone or as a mixture of two or more kinds.

As the curable urethane resin, a two-component curing type urethane resin, a one-component curing type (moisture curing type) urethane resin or the like may be used. In the case of a two-component curing type urethane resin, polyol is used as a main component and polyvalent isocyanate is used as a crosslinking agent. Examples of polyols include acrylic polyols, polyester polyols, polycarbonate polyols, polyether polyols and polyurethane polyols, and examples of polyvalent isocyanates include 2,4-
Aromatic isocyanates such as tolylene diisocyanate, xylene diisocyanate, diphenylmethane-4,4'-diisocyanate, etc. Aliphatic (or alicyclic) such as 1,6-hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate
Isocyanates are used. Alternatively, as the isocyanate, a multimer or an adduct of these isocyanates may be used.

The one-component curing type (moisture curing type) urethane resin is a composition containing a prepolymer having an isocyanate group at the molecular end as an essential component. The prepolymer, by the reaction of the above polyols and isocyanate,
Usually, it is a polyisocyanate prepolymer having one or more isocyanate groups at both ends of the molecule. The isocyanate groups react with each other by the moisture in the air to cause a chain extension reaction, resulting in a reaction product having a urea bond in the molecular chain, and this urea bond is further reacted with the isocyanate group at the molecular end. Then, a biuret bond is generated and branched to cause a crosslinking reaction.

The adhesive layer can be formed by a known printing or coating method such as gravure printing or roll coating, using the ink (or coating liquid) containing the resin as described above. The thickness of the adhesive layer is not particularly limited, but is, for example, 5 to 2
It is about 0 μm. When the second layer is laminated on the surface of the first layer, on which the pattern layer is formed, on the side of the pattern layer simultaneously with the film formation by the multi-layer extrusion method, the second layer is heat-melted. It can also be omitted by adhering by wearing. However, when the resin sheet of the first layer on which the pattern layer is formed and the resin sheet (laminated sheet) preliminarily formed as the second layer are separately prepared, and these are laminated by the dry lamination method, Are adhesively laminated by this adhesive layer.
In this case, the adhesive layer is on the first layer (pattern layer) side, the second layer side, or both. In addition, the surface to be bonded with the adhesive layer may be subjected to an easy adhesion treatment such as corona discharge treatment, plasma treatment, and primer coating, if necessary, in order to enhance the adhesion.

Laminating Method of Decorative Molding Sheet on Adherend: When laminating the decorative molding sheet of the present invention on an adherend, the laminating method is such that the sheet is heat-softened and molded. The method is preferable in that the effects of the present invention can be exhibited and enjoyed. The adherend is preferably a resin molded product made of a polyolefin resin from the viewpoint of the adhesiveness of the sheet. By laminating the decorative molding sheet on the adherend,
A decorative molded product is obtained as a laminate of the adherend and the decorative molding sheet. Specific methods for molding and laminating the decorative molding sheet include, for example, (1) injection molding simultaneous decorating method and (2) vacuum molding laminating method. These will be further described below.

(1) Simultaneous decoration method by injection molding: Japanese Patent Publication No. 50
As described in JP-A-19132, JP-B-43-27488, etc., a decorative molding sheet is placed between male and female molds for injection molding, and then a resin in a fluid state is injection-filled into the molds. It is a method of laminating a decorative molding sheet on the surface of a resin molded product at the same time as molding. The decorative molding sheet is molded by the injection molding die itself or an external molding die. (2) Vacuum forming and laminating method: As described in JP-B-56-45768 (overlay method), JP-B-60-58014 (vacuum pressing method) and the like, a three-dimensional adherend such as a molded product is formed. A method for laminating a decorative molding sheet on the surface of a substrate by facing or placing the decorative molding sheet with an adhesive in between, and molding the decorative molding sheet by a pressure difference due to at least vacuum suction from the adherend side. Is.

Next, among the above, the injection-molding simultaneous decoration method will be described in more detail.

First, in the injection molding simultaneous laminating method, even if the decorative molding sheet is not preheated, the decorative molding sheet is subjected to the heat pressure by the injection resin. Therefore, the injection-molding simultaneous decorating method is suitable whether or not the decorating sheet is preliminarily molded. Further, the decorative molding sheet may or may not be preheated. During the preforming, the decorative forming sheet is usually preheated. Among these, a mode in which the effect of the present invention can be enjoyed is preferable, in which the decorative forming sheet is heated and softened to be preformed (which is also particularly an offline preformed form).
Is.

Of course, if the decorative forming sheet has a large drawing, it is preferable to carry out preforming. On the other hand, when the decorative forming sheet has a small drawing amount, the decorative forming sheet may be formed by the resin pressure and the resin heat of the injected resin in a fluid state. At this time, if the drawing is shallow, the decorative molding sheet may be molded only by the resin pressure and the resin heat of the resin in a fluid state filled in the mold at the same time as the resin injection without preforming. Further, even when the decorative molding sheet is molded by the resin pressure and the resin heat, the decorative molding sheet may be heated only by the resin heat of the injection resin and may not be preheated. Further, the pre-molding of the decorative molding sheet is usually performed by using the injection molding die also as the vacuum molding die, but before the decorative molding sheet is fed between the molds, another molding is performed outside the injection molding die. It is also possible to perform preforming (offline preforming) in which a decorative forming sheet is vacuum formed using a vacuum forming die. However, the preforming is preferably performed by using both the injection molding die and the vacuum molding die in order to efficiently and accurately stack the decorative molding sheets. However, in the case where the preformed decorative forming sheets are collectively manufactured in advance at another place, the preforming is preferably an off-line preforming form. In the description of the present invention, vacuum forming includes vacuum pressure forming.

A method for simultaneously decorating injection molding will be described with reference to the conceptual diagram of FIG. In the form shown in the figure, a vacuum molding die, which is a mold different from the injection molding die, heats and softens the decorative molding sheet to preform it, and then the molded decorative molding sheet is injected into the injection molding die. This is a form of off-line pre-molding in which the resin is injected after being inserted into the mold. Next, the injection-molding simultaneous decoration method in this embodiment will be further described with reference to FIG. Further, this form is preforming of the above-mentioned decorative forming sheet, among various combinations of preheating, when the thickness of the decorative forming sheet is thick, when the drawing of the decorative forming sheet is deep, This is a more preferable form.

First, as shown in FIG. 3A, the suction holes 3 are formed in the mold surface.
Using a vacuum forming mold Mv having a suction means such as 1, a decorative forming sheet softened by heating with the heater 32 is preformed by vacuum forming. The vacuum forming mold Mv is made of metal such as iron or aluminum, or ceramics. Further, the decorative molding sheet S is appropriately frame-shaped sheet clamp 3
Fix at 3. At this time, the second layer side of the decorative molding sheet is oriented toward the injection resin side (upper side of the drawing). Also,
The heating and softening by the heater 32 is, for example, non-contact radiant heating, but conductive heating by contact may be used. Then, in the preforming, the decorative forming sheet is vacuum-formed by suction through the suction holes, and the decorative forming sheet is vacuum-formed along the die surface of the vacuum forming die Mv.
The vacuum forming may be a vacuum pressure forming in which pressure is also used, which is also included.

Next, as shown in FIG. 3 (B), the preformed sheet S for decorative molding is subjected to a pair of injection molding dies Ma and Mb.
Supply between and. Here, the injection mold Ma is a runner and a sprue (gate) that communicate with the injection nozzle.
The injection molding die Mb has a cavity surface having the same or substantially the same shape as the die surface of the preforming die Mv, and serves as a die for fixing the preformed decorative forming sheet. These molds are made of metal such as iron or ceramics. In the mold open state, the decorative molding sheet S is supplied between the two molds Ma and Mb, and the decorative molding sheet S is fixed to the mold Mb by pressing it with a frame-shaped sheet clamp 34. At this time, it goes without saying that the second layer side of the decorative molding sheet is the injection resin side on the right side of the drawing. Next, as shown in FIG. 3 (C), the two molds are clamped, and the cavity formed by both molds is filled with a resin in a fluid state such as a heating and melting state. Then, after the resin is solidified by cooling or the like, the mold is opened and the molded product is taken out. Further, if there is an unnecessary portion of the decorative molding sheet, trimming the trimming portion appropriately allows the decorative molded sheet S to be laminated on the surface of the resin molded product 5 as shown in the sectional view of FIG. This is a decoration method in which a decorative molded product P is obtained.

In the above process, if the dimensional shrinkage of the sheet after preforming is large, the size and shape of the mold match during the subsequent injection molding, and the size is forcibly corrected to the mold shape by the injection resin. Therefore, a defective molding such as wrinkles occurs in the decorative molding sheet after being laminated on the surface of the resin molded product.
Further, in the form of off-line preforming, there may be a forming defect such that the decorative forming sheet after forming the sheet cannot be mounted on the injection mold. However, in the present invention, since the filler is added to the second layer, dimensional shrinkage can be prevented and wrinkles do not occur. Moreover, even if a filler is added, the second layer added has a multilayer structure with no filler added on the first layer side, so irregularities occur on the surface of the decorative molded product and the specularity deteriorates. It also prevents molding defects.

Decorative Molded Product : Next, the decorative molded product according to the present invention is a decorative molded sheet having the above-described structure, such as the decorative molded product P whose one form is illustrated in the sectional view of FIG. S is
It is a molded product having a layered structure such that it is laminated on the surface of a resin molded product 5 made of a polyolefin resin. In the figure,
Although the illustration of the sheet inner layer structure of the decorative molding sheet S is omitted, this portion has a structure as illustrated in the cross-sectional view of FIG. 1, for example, and the second layer 2 side with respect to the first layer 1 The decorative molding sheet S is laminated on the resin molded product 5 so as to face the resin molded product 5 side. The decorative molding sheet S may be laminated on the resin molded product 5 by a vacuum molding lamination method or the like. It is preferable to use a decoration method.

In the polyolefin resin constituting the resin molded product, a resin colored by adding a coloring agent may be used depending on the application. As the colorant, a known colorant as described in the pattern layer may be used. Also,
If necessary, the resin may contain various known additives such as silica, alumina, talc, calcium carbonate, inorganic powder such as aluminum hydroxide, filler such as glass fiber, stabilizer, lubricant, elastomer and the like. . Further, the resin of the resin molded product is mainly a polyolefin resin, but other resins may be mixed within the range of subcomponents.

Incidentally, the shape of the decorative molded product is usually a three-dimensional object in which the laminated surface of the decorative molding sheet is a non-planar surface such as an uneven surface. However, the decorative molded product of the present invention does not exclude a three-dimensional object in which the laminated surface of the decorative molded sheet is a flat surface but the other surface is non-planar, and a plate-shaped object in which the laminated surface is a flat surface. In the process of laminating on a plane, the decorative molding sheet may be heat-molded and stretched. Further, the overall shape of the decorative molded product is arbitrary such as a plate shape (flat plate, curved plate), columnar shape, and three-dimensional solid object.

Applications of decorative molding sheets and decorative molded products :
In addition, the application of the decorative article such as a decorative molded article whose surface is decorated with the above-mentioned decorative molding sheet is arbitrary, for example, an interior material or an exterior material of a vehicle such as an automobile, a skirting board, and a rim. And the like, fittings such as window frames and door frames, interior materials for buildings such as walls, floors, and ceilings, housings and containers for home electric appliances such as TV receivers and air conditioners.

[0055]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples.

[Example 1: Addition of filler other than the surface layer] FIG.
A decorative molding sheet S having a structure as shown in the sectional view of (B) was produced as follows. First, as a non-colored and transparent resin sheet for the first layer 1, a resin sheet having a thickness of 125 μm containing polymethyl methacrylate (PMMA) as a main component was prepared. Then, on the back side of this resin sheet, a mixed resin of an acrylic resin containing butyl methacrylate and a vinyl chloride-vinyl acetate copolymer is used as a binder resin, and quinacridone red, isoindolinone, phthalocyanine blue is used as a colorant. , A pattern layer 3 expressing a wood grain pattern with a colored ink using carbon black
Was formed by a gravure printing method to obtain a printed sheet.

On the other hand, as the second layer 2, a laminated sheet (resin sheet) was separately prepared in which a three-layered structure including a surface layer 2A, a central layer 2C and a back layer 2B was laminated simultaneously with film formation by a three-layer coextrusion method. . For each of the surface layer 2A and the back layer 2B, a polypropylene-based olefinic thermoplastic elastomer (60 parts by weight of polypropylene and 40 parts by weight of an elastomer) (a filler and a coloring pigment were not added) was used. Further, in the central layer 2C, 70 parts by mass of a polypropylene-based olefinic thermoplastic elastomer obtained by mixing 30 parts by mass of an elastomer with 40 parts by mass of a polypropylene resin, 20 parts by mass of talc as a filler, and a colored pigment as a coloring agent. 1
A resin having a color concealing property added with 0 part by mass was used. The thickness of these three layers is as follows: surface layer 2A / center layer 2C / back layer 2B = 30
μm / 290 μm / 30 μm, and the total thickness as a laminated sheet is 350 μm.

Then, 10 g / m ² of a solid adhesive of polyester type curable urethane resin was applied to the surface of the printed sheet on the side of the pattern layer in a solid content, and the surface layer 2A of the laminated sheet was dried by a dry lamination method. I stuck it to the side surface. Then, it was cured at 40 ° C. for 3 days to obtain a desired decorative molding sheet S.

[Comparative Example 1: Filler-added single layer] In Example 1, instead of the laminated sheet to be stuck to the printing sheet, a film formed of the resin used for the center layer 2C had a thickness of 350 μm.
A decorative molding sheet was produced in the same manner as in Example 1 except that the single-layer resin sheet of 1 was used.

[Comparative Example 2: Addition of no filler] In Comparative Example 1, a single-layer resin sheet having a thickness of 350 μm was used instead of the resin sheet to be bonded to the printing sheet, except that the addition of the filler was omitted. A decorative molding sheet was produced in the same manner as in Example 1. The resin blend used in the above resin sheet is a polypropylene-based olefin-based thermoplastic obtained by blending polypropylene by changing 40 parts by mass of resin to 50 parts by mass and elastomer by changing 30 parts by mass to 40 parts by mass. Color pigment 10 to 90 parts by weight of elastomer
A resin added with parts by mass was used.

[Performance Evaluation] With respect to the decorative molding sheets obtained in each of the examples and comparative examples, a decorative molded product was further prepared by the injection molding simultaneous decoration method in which the sheets were softened by heating in preforming. did. Then, evaluation was made based on the presence or absence of shrinkage of sheet size and deterioration of specularity of the surface of the molded product at that time. In addition,
The size of the decorative molded product is a test plate with a length and width of 80 mm × 150 mm and an aperture of 10 mm, and the vacuum forming mold for preforming is 80.8 mm × 151 mm in length and width, and after vacuum forming as in general injection molding simultaneous decoration. A mold larger than the final molded product size was used in consideration of shrinkage.

That is, the injection-molding simultaneous decoration is performed by using the above-mentioned decorative molding sheet by an injection-molding simultaneous decoration method adopting an offline preforming mode as shown in the conceptual explanatory view of FIG. As a decorative molding, a sheet of the decorative molding S is laminated on the resin molded product 5 as shown in the sectional view of FIG. Item P was obtained.

The injection-molding simultaneous decoration is as follows.
As shown in FIG. 3 (A), the vacuum molding die Mv has the same cavity surface as the injection molding female die Mb, but is separate from the female die Mb.
The decorative molding sheet S was heated to a surface temperature of 170 ° C. in a non-contact state to be softened by a heater 32 composed of an infrared radiation type heating plate, and was then punched in a vacuum molding die Mv. Vacuum suction was performed from the suction holes 31, preforming was performed on the cavity surface of the vacuum forming die Mv, and cooling was performed to release the preformed decorative forming sheet. Then, as shown in FIG. 3 (B), the preformed decorative molding sheet S is injection molded by the sheet clamp 34 with the second layer side facing the male mold Ma side for injection molding. 3C, the male and female dies are clamped, and the cavity formed by the male and female dies is injection-filled with the polypropylene resin that has been melted by heating to be cooled and solidified. After forming a decorative molded product integrated with the decorative molding sheet, the male and female molds were opened and the decorative molded product was taken out.

As a result, the surface specularity was good in the case of Example 1 and Comparative Example 2 in which the filler was not added to the second layer at the stage after the preforming by vacuum forming. But,
In the case of Comparative Example 1 which is a second layer of a single layer by adding a filler,
The surface became orange-skin-like unevenness and the specularity deteriorated.

At the injection molding stage after this preforming, in the case of Example 1, the dimensional shrinkage of the preformed decorative molding sheet to the injection molding die was gentle and the mountability was good. The resulting decorative molded product was good with no molding defects such as wrinkles in its appearance. On the other hand, in the case of Comparative Example 2 in which the filler was not added, the dimensional shrinkage after preforming was large, and the injection-molded mold could not be fitted with the molded decorative molding sheet, and was dislocated from the injection mold. In addition, since the decorative molding sheet is easily bent, injection molding has not been achieved. On the other hand, in the case of Comparative Example 1 in which the filler was added but the second layer was a single layer, the surface irregular skin-like unevenness did not disappear even after injection molding, and the decorative molded product had a poor appearance.

[0066]

(1) According to the decorative molding sheet of the present invention, it is possible to prevent dimensional shrinkage at the time of molding the sheet and also prevent deterioration of the specularity of the surface of the molded product. Therefore, when dimensional shrinkage occurs, it is possible to prevent molding defects such as wrinkles generated in the decorative molding sheet laminated on the surface of the molded product by simultaneous injection molding and decoration. Also,
Simultaneous injection molding decoration in the form of preforming with a mold different from the injection mold that is suitable when the thickness of the decorative molding sheet is large (for example, 0.3 mm or more or 0.4 mm or more) Thus, it is possible to prevent a molding defect in which the dimension of the pre-formed decorative molding sheet does not match the size of the injection molding die due to the dimensional shrinkage and cannot be mounted on the injection molding die. Moreover, it is possible to prevent deterioration of the specularity of the surface of the molded product, which is conventionally caused by the hot molding of the sheet, which is caused by the addition of the filler. (2) Further, the second layer of the polyolefin-based resin is formed by the multi-layer coextrusion method, so that the number of steps for preparing the second layer as a resin sheet for each layer and laminating the second layer does not increase, resulting in high cost. Can also be prevented. In addition, interlayer adhesion within the second layer can be obtained more reliably. (3) If a pattern layer is laminated on the back surface of the first layer,
A high design can be achieved by the pattern layer. (4) Further, when the first layer and the second layer are laminated via the adhesive layer, the first layer and the second layer can be laminated with good adhesion. (5) According to the decorative molded product of the present invention, the resin molded product of the polyolefin resin and the decorative molding sheet have good adhesion,
It is possible to enjoy the respective effects obtained by the decorative molding sheet, such as preventing wrinkles and deterioration of the specularity of the surface due to defective molding during sheet molding in the decorative molding sheet portion. And
The decorative molding sheet has a large thickness, and the decorative molded article is suitable for simultaneous injection molding in the offline preforming mode.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating a form example of a decorative molding sheet according to the present invention.

FIG. 2 is a cross-sectional view illustrating one form of a decorative molded product according to the present invention.

FIG. 3 shows an application example of the decorative molding sheet of the present invention.
The conceptual diagram explaining the injection-molding simultaneous decoration method in the one form.

[Explanation of symbols]

1 first layer 2 Second layer 2A surface 2B back layer 2C central layer 3 picture layers 4 Adhesive layer 5 Resin molding 31 suction hole 32 heater 33 seat clamp 34 seat clamp Ma injection mold (male mold) Mb injection mold (female mold) Mv vacuum forming mold P decorative molded products Sheet for decorative molding

Continued front page    F term (reference) 4F100 AC10 AK01A AK03B AK03C                       AK03D AK07 AK15J AK22J                       AK25 AK51G AL01 AL05                       AL09 BA03 BA04 BA07 BA10A                       BA10C BA10D CA23C EC18                       EH20 HB00A JN01A

Claims (5)

[Claims] 1. A decorative molding sheet in which a first layer made of a transparent thermoplastic resin and a second layer made of a polyolefin resin are laminated in this order from the front side, and the second layer is at least 2 A decorative molding sheet having a multi-layered structure including at least one layer, in which a filler is not added to the side facing the first layer and the filler is added to other layers. 2. The decorative molding sheet according to claim 1, wherein the second layer is formed by a multi-layer coextrusion method. 3. The decorative molding sheet according to claim 1, wherein a pattern layer is laminated on the back surface of the first layer. 4. The decorative molding sheet according to claim 1, wherein the first layer and the second layer are laminated via an adhesive layer. 5. The decorative molding sheet according to any one of claims 1 to 4, wherein the second layer side is on the resin molded product side on the surface of the resin molded product made of a polyolefin resin. A decorative molded product that is laminated toward each other.