JP2001219444A - Synthetic resin molding and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin molding such as a bathtub of a long service life and its production method which is excellent in working environment and low in fraction defective in producing. SOLUTION: The synthetic resin molding comprises an inner surface layer material of a transparent resin sheet and an outer surface layer material which is produced by injecting a colored/decorated molten thermoplastic resin on the back side of the inner surface layer material and compression-molding the resin while being contacted with the inner surface layer material. 1: inner surface layer material, 3: male mold (movable mold) of injection compression molding machine, 4: decorated thermoplastic resin, 5: female mold (fixed mold) of injection compression molding machine, 6: gate of injection compression molding machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a bathtub, a sink,
The present invention relates to a molded article made of a synthetic resin such as a wall, a floor, and a ceiling, and a method for producing the same.

[0002]

2. Description of the Related Art An acrylic resin bathtub will be described as an example of a synthetic resin molded body. Usually, an acrylic resin sheet is heated and softened, and then formed into a desired bathtub shape by vacuum forming, and used as a reinforcing material for a backing. It is manufactured by spraying a glass fiber reinforced plastic (hereinafter referred to as FRP) with a spray gun or forming a layer of such a reinforcing material by a hand lay-up method, smoothing the FRP layer while defoaming, and then curing. I have.

[0003] However, when manufacturing the bathtub,
Workers perform FRP spraying, hand lay-up work, and even smoothing work, which results in poor production efficiency. In addition, not only glass fiber adheres to the worker's clothes, but also glass fiber adheres to the skin. However, there is a problem that the worker absorbs the scattered glass fiber and causes an obstacle.

[0004] Further, since the difference in thermal expansion coefficient between the acrylic resin sheet used in the bathtub and the FRP is large,
During long-term use, the acrylic resin sheet is distorted and deteriorated due to a temperature change, and thus has a problem that its useful life is short.

Further, there is a type in which an acrylic resin sheet molded body is set in a mold and a synthetic resin melted by heating and melted from the back is reinforced by injection molding. This causes problems such as warpage. On the other hand, inject foamable synthetic resin on the back side,
After that, there is also a method of reinforcing by foaming,
Although excellent in heat insulation, the acrylic resin sheet and the synthetic resin are mainly brought into contact with each other by the foaming pressure, so that there is a case where the adhesion is insufficient and peeling occurs or the synthetic resin does not completely reach the mold.

[0006] In addition, there has been a problem that a synthetic resin bathtub is liable to be stained by mold and the like, and a side wall that is difficult to be stained or that can be easily removed even if stained is sought. ing. In addition, above all, in the above-mentioned respective manufacturing methods, when dusts or the like are adhered to the mold surface, the dust directly penetrates into the surface of the molded body, so that the so-called mirror surface of the molded body surface is roughened. For this reason, the manufacturing operation is performed in a clean room, but the manufacturing process is complicated, which inevitably leads to an increase in cost.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has an excellent working environment, has a low occurrence of a defective rate during production, is difficult to adhere dirt, and is easy to remove. An object of the present invention is to provide a synthetic resin molded article such as a bathtub having a long service life and a method for producing the same.

[0008]

A first aspect of the present invention relates to a molded article made of a synthetic resin, which comprises an inner layer material made of a transparent resin sheet and a colored decoration on the back side of the inner layer material. Injected heat-melted thermoplastic resin, and the outer layer material compression-molded while contacting the inner layer material, characterized in that, preferably, the inner layer material has water repellency It is a transparent resin sheet shown.

A second aspect of the present invention is a method of manufacturing a synthetic resin molded body, wherein a transparent resin is formed into a sheet to obtain an inner layer material, and the inner layer material is obtained on the surface side of the synthetic resin molded body. Is set in a mold of an injection compression molding machine so that a thermoplastic resin containing a colorant that has been heated and melted is injected into the mold, and then the heat injected with the inner layer material set is set. A plastic resin is compressed, and the inner layer material and the thermoplastic resin are bonded to form a colored and decorated outer layer material.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The embodiment of the present invention will be described mainly with reference to the second invention. This is a manufacturing method using an injection compression molding method for a thermoplastic resin which is heated and melted, wherein the inner layer material is made of a transparent resin. The sheet is formed by injection-compression molding of a heated and melted thermoplastic resin colored and decorated with respect to a transparent resin sheet to be the surface of the molded article. In this case, the transparent resin sheet and the thermoplastic resin are used. To prevent poor adhesion and separation between resins.It is excellent in production efficiency at the time of molding.It is also easy to use the environment by using a thermoplastic resin. Is less likely to occur, and there is little change over time.

[0011] That is, since there is almost no manual production process by the operator and the molding operation is mainly performed in a mold, the working environment and the safety and hygiene are excellent, and the inner layer material and the injection compression molding side (outer surface). There is no poor adhesion or peeling between the thermoplastic resin on the reinforcement side) and excellent production efficiency. Even in the obtained molded product, the inner surface layer material and the outer reinforcement layer The adhesion with the thermoplastic resin used as the material is ensured, and the difference in the coefficient of thermal expansion is small. Things.

In particular, when the protective sheet is laminated with an adhesive on the surface of the transparent resin sheet, the protective sheet protects the transparent resin sheet from dust and the like existing in a mold at the time of molding, and the mirror surface state of the surface. , Which brings great advantages in production.

For the transparent resin sheet as the inner layer material used in the present invention, for example, acrylic resin, PET resin, AS resin, PVC resin, PP resin, PE resin, AB
A sheet selected from S resin and PS resin is used, and among them, an acrylic resin sheet or a PET resin sheet is preferably used.

The acrylic resin sheet is a glossy and soft material, and is characterized by being resistant to dirt and scratching, and is also advantageous in terms of repair, and is an excellent surface layer material. is there. It is to be noted that it is possible to use the composition as it is with transparency, but it may be a composition containing a coloring agent such as a pigment or an inorganic mineral selected as necessary. It is also possible to improve the design by applying a pattern on the back side of the acrylic resin sheet with, for example, an acrylic paint. The thickness of the transparent resin sheet constituting the inner layer material is appropriately selected, and includes a plate shape, a sheet shape, and a film shape. .

Such an acrylic resin sheet is usually used as an inner layer material of a synthetic resin molded article to be obtained by vacuum forming, and the acrylic resin sheet is formed so as to face the front side. Things. In addition, the vacuum forming method using a female mold is preferable because a molded article having a smooth inner surface is obtained. Of course, it is a matter of course that an unshaped flat plate can be used as the inner layer material. The thickness of the acrylic resin sheet of the present invention is not particularly limited, but is about 1.5 to 20 mm, preferably 5 to 20 mm.
15 mm, more preferably 7 to 12 mm is used.

The acrylic resin sheet is, for example, a cast sheet made of polymethyl methacrylate acrylic resin, which is used without being crosslinked.
A partially crosslinked acrylic resin sheet is excellent in surface hardness and chemical resistance and has excellent properties at the time of molding, and is preferably used in the present invention.

As the inner layer material, a PET resin sheet is also preferably used, which is obtained by condensation polymerization of dimethyl terephthalate and ethylene glycol, and has excellent mechanical strength and excellent abrasion resistance. It is a sheet.

The protective sheet to be laminated on these transparent resin sheets is preferably a sheet that is more flexible than the transparent resin sheet, so that dust or the like in the mold easily deforms and wraps around. It is. A typical example of the protective sheet is a PE resin sheet, but PP, soft PVC, or the like is also used. The protective sheet is coated with an adhesive layer, and is provided for lamination with a transparent resin sheet.

In the present invention, it is preferable that the outermost surface of the inner layer material made of a transparent resin sheet shows water repellency in order to prevent the adhesion of dirt and to easily remove dirt.
The water repellency is preferably such that the contact angle of water is 90 ° or more. Means for imparting water repellency to the surface of the transparent resin sheet include applying a silicone-based compound to the surface of the transparent resin sheet, or using a water-repellent resin sheet containing a silicone-based compound. Achieved by further laminating the sheet, applying a fluorine-based compound on the surface of the transparent resin sheet, or further laminating a water-repellent resin sheet comprising or blended with a fluorine-based compound. Is done.

In order to make the surface of the transparent resin sheet water-repellent, a silicone-based compound having a main chain of a polyorganosiloxane such as polydimethylsiloxane, polyphenylmethylsiloxane and polydiphenylsiloxane is used. Is used. As a method of applying a silicone-based compound to the surface of a transparent resin sheet of PET or acrylic resin, an emulsion or solvent solution of a heat-condensed or heat-added silicone-based compound is applied by a bar coating method or a doctor method. −
It is applied by a blade method, a roll coat method, a flow coat method, etc., and is dried and cross-linked in a hot air oven, or an emulsion of a radiation- or ultraviolet-curable reactive polyorganosiloxane or The solvent solution is applied by a bar coating method,
The polyorganosiloxane is applied by a doctor blade method, a roll coat method, a flow coat method or the like, and irradiated with radiation or ultraviolet rays to crosslink and cure the polyorganosiloxane. Examples of the thermal condensation type include those obtained by reacting silanol-functional dimethylpolysiloxane at both ends with methylhydrogenpolysiloxane or methylmethoxysiloxane in the presence of an organotin-based catalyst. Examples of the heat addition reaction type include those obtained by reacting methylvinylpolysiloxane having a vinyl group at both molecular terminals or both terminals and a side chain with methylhydrogenpolysiloxane in the presence of a platinum-based catalyst. UV curing type is a polyorganosiloxane containing an alkenyl group and a mercapto group plus a photopolymerizing agent,
Examples include (meth) acrylic group-containing polyorganosiloxanes added with a photopolymerizing agent, epoxy group-containing polyorganosiloxanes added with an onium salt photoinitiator, and the like. Examples thereof include a polyorganosiloxane having a functional group.

As a method for further laminating a water-repellent resin sheet in which a silicone-based compound is blended on the surface of a transparent resin sheet of PET or acrylic resin, acrylic resin, P
An acryloyl group on a thermoplastic resin such as ET resin, AS resin, PVC resin, PP resin, PE resin, ABS resin,
Water-repellent films or acrylic silicones to which a polymerizable polyorganosiloxane having a methacryloyl group, a vinyl group, a mercapto group or the like at one or both ends, or a side chain, or a polyfunctional compound as required, are added. Heat-bonding a film made of a silicone-based resin that exhibits water repellency by itself, such as a copolymer, or extruding through an adhesive or an adhesive film, a lamination method, a co-extrusion method, or a dry lamination method. Laminate with If necessary, immobilization is performed by irradiation with an electron beam or the like or irradiation with ultraviolet rays.

To make the surface of the transparent resin sheet water-repellent with a fluorine compound, the surface of the transparent resin sheet is treated with a fluorine compound such as fluoroalkyl acrylate or polyorganosiloxane having a fluoroalkyl group. Or ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, PTFE, FEP, PCTFE, ECTFE,
Extruding a water-repellent resin sheet made of a fluorine-based compound such as PVdF or PVF onto a transparent resin sheet through heat fusion, an adhesive or an adhesive film, a lamination method, a co-extrusion method, and a dry lamination method. Laminate with
If necessary, immobilization is performed by irradiation with an electron beam or the like or irradiation with ultraviolet rays.

The thermoplastic resin used for the injection compression is not particularly limited as long as it can be fused with the inner layer material. Typical examples of such a thermoplastic resin include acrylic resin and PET resin. , AS resin, P
It is selected from VC resin, PP resin, PE resin, ABS resin, PS resin and the like. It is preferable that the thermoplastic resin is mixed with a coloring agent, an inorganic filler, or the like, and subjected to a decorating treatment. Needless to say, it is preferable that the resin is the same as the resin constituting the inner surface layer material, and the two can be thermally welded. If different materials are used, an adhesive or the like may be interposed.

Such a thermoplastic resin undergoes an injection step and a compression step in a mold such as a large unit bath or a storage panel having a complicated shape, so that the melt flow rate is an important factor. Two or more, preferably five or more, more preferably 15 or more are good.

Above all, ABS having good adhesion to the inner layer material, excellent impact resistance, and high rigidity in a high temperature range
Resins are particularly preferred. Needless to say, various additives can be added to the thermoplastic resin in addition to the coloring agent described above. Glass fibers, talc, inorganic fillers such as mica, flame retardants, antibacterial agents such as silver complex antibacterial agents, and the like. There are a fungicide and a foaming agent such as azodicarbonamine. When a foaming agent is blended, the thermoplastic resin layer (outer surface layer material) becomes porous and has excellent heat insulating properties. In addition, it is preferable to add glass fiber because the glass fiber has excellent rigidity. In this case, the glass fiber length and blending amount are arbitrarily selected, but are usually adjusted to be about 1 to 6 mm and about 5 to 30% by weight.

The above-mentioned thermoplastic resin is heated and melted in advance, and the pressure at the time of injection into the mold is set so that the projected area of the mold is large and the inner surface layer material is not damaged. It is preferable to perform injection molding at a pressure as low as possible, and is about 50 to 150 kg / cm ² .

Then, the thermoplastic resin melted by heating and being melted is injected into the mold, and then (or simultaneously) compression is started, but the resin is compressed with the mold in which the inner layer material is set. By this, the resin is spread to every corner of the mold, and is brought into complete contact with the set inner surface layer material, where the two are integrated. The injection molding machine to be used may be either a vertical type or a horizontal type, but a type having a structure in which a vertical type, that is, a mold is relatively opened and closed in a vertical direction is preferably used.

In order to further enhance the adhesive effect between the two, it is natural that an adhesive is used as appropriate. For example, there is a method of applying a two-part urethane-based adhesive as an example of the adhesive. However, the adhesive is appropriately selected depending on the properties of both resins.

In the injection compression molding method, a molten resin is supplied through a gate into a cavity formed by a plurality of molds facing each other, the mold is moved, shaped, pressed and cooled to form a molded body. How to get. Since the resin has a low shear stress at the time of shaping and can be cooled with a substantially uniform pressure after shaping, it has the characteristics that the residual strain is small and the deformation is small. On the other hand, according to the conventional method, since the shearing rate of the resin is increased, the residual strain during molding is large, and the deformation after molding is correspondingly large.

[0030]

The present invention will be described in more detail below. As a specific example, the acrylic resin sheet 1 used had a thickness of 10 mm as shown in a bathtub molding example. Then, the acrylic resin sheet 1 is 180
The inner layer material 10 was obtained by shaping the shape of the bathtub, that is, the inner shape of the bathtub at a temperature of ° C. It should be noted that only one surface (the surface of the final product) of the acrylic resin sheet 1 shows water repellency and its thickness is
It was 0 μm. Then, in order to make one side of the resin sheet water-repellent, a MEK solution of a reaction of silanol-functional dimethylpolysiloxane at both ends and methylhydrogenpolysiloxane in the presence of an organotin-based catalyst is rolled. It was applied by a coating method and dried.

FIG. 1 is a conceptual view of such a process, in which an acrylic resin sheet 1 is set on a vacuum forming machine (not shown) having a vacuum forming die (female die) 2 having a shape corresponding to the inner surface shape of the bathtub. This is heated and softened, and then evacuated to obtain the inner layer material 10 having the inner shape of the bathtub. Needless to say, this step is omitted when obtaining a flat molded body such as a ceiling wall.

Next, a vertical injection compression molding machine (3000)
The pressed inner surface layer material 10 is set in the male side mold 3 of a ton press), and the colored alumina oxide is filled, and the granulated ABS resin 4 is melt-injected into the mold at 250 ° C. Then, the resin 4 is compressed by the male mold 3 and cooled to form an acrylic resin sheet 1 as a surface material.
And a bathtub provided with an ABS resin layer 4 as an outer layer material.
The contact angle of water on the surface of the outer layer material having water repellency is 110.
〓, showing sufficient water repellency, good wiping properties of the magic ink, and sufficient antifouling properties.

FIG. 2 is a conceptual diagram showing the injection / compression step, in which the obtained inner layer material 1 is set so as to be in contact with the surface of the movable side mold (convex side) 3 of the injection mold. The movable mold 3 is moved in the mold closing direction, that is, toward the lower side with the inner layer material 1 being set, and the fixed mold (concave side) 5 and the movable mold 3 are closed.

After the molds 3 and 5 are closed, the thermoplastic resin 4 previously heated and melted is injected from the gate 6 into a mold surrounded by the inner layer material 1 and the fixed mold 5. The pressure at which the heat-melted thermoplastic resin 4 is injected into the mold from the gate 6 is preferably injection-molded at a pressure as low as possible in order to prevent the inner layer material 1 from being damaged. Here, it was 100 kg / cm ² . Also,
The melt flow rate was 20.

Then, the thermoplastic resin 4 in the mold is compressed by sliding the male mold 3 in which the shaped inner layer material 1 is set, and the mold is filled with the thermoplastic resin 4. And is brought into contact with the inner layer material 1 to be integrated therewith. Next, the mold is cooled, the molded product is cooled and the mold is opened, whereby a bath tub whose outer surface is reinforced with a transparent acrylic resin sheet 1 and whose back surface is decorated with a thermoplastic resin 4 is obtained. Was.

Next, regarding the transparent resin sheet, a protective sheet may be laminated on the transparent resin sheet.
It is obtained by laminating a PE resin sheet (100 μ) as a protective sheet on an ET resin sheet (100 μ). A hot melt adhesive was used as the adhesive layer. still,
A backing sheet may be further laminated on the back side of the transparent resin sheet. For example, a urethane adhesive is applied on the back side of the transparent resin sheet, and an ABS resin sheet (100 μm) is applied thereto.
Are used as a backing resin sheet, these are guided to a pair of rolls as shown in FIG. 3, and three persons are laminated, and the laminated material 20 is used according to the above-mentioned molding example. In the figure, 20a is a transparent resin sheet, 20b is a protective sheet, 20c is an adhesive layer coated on the protective resin sheet, 20c is a protective sheet, 20d is an adhesive layer, 20e is a backing resin sheet, and 20f is a pair of rolls. .

At the time of such molding, if dust or the like adheres to the surface of the mold, the transparent resin sheet 20a directly comes into contact and is damaged in a normal case (there is no protective sheet 20b). In the case of the above example, the transparent resin sheet 20a
Without contacting, a soft resin sheet (protective sheet 20b) disposed outside is in contact with this, and a molded body is obtained in a state of absorbing the soft resin sheet. Therefore, a molded body with no scratch on the mirror surface (surface) is obtained. Is obtained. Therefore,
There is an advantage that it is not necessary to perform a manufacturing operation in a clean room. If the allowable size of the dust is about 30% of the thickness of the protective sheet, the dust is absorbed by the protective sheet.

[0038]

According to the molded article of the synthetic resin of the present invention and the method for producing the same, the occurrence of defects in the production process is reduced, and the work environment such as the spraying of FRP as in the prior art is eliminated.
Moreover, complicated work is not required. Also, the synthetic resin molded article of the present invention uses a thermoplastic resin as the outer reinforcing layer instead of the conventionally used FRP. Since the difference in thermal expansion coefficient from the resin is small and the adhesive layer is interposed between the resin and the resin, the durability is also improved. The value of the transparent resin sheet is further increased by imparting antifouling properties.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a method for producing an inner layer material according to the present invention.

FIG. 2 is an explanatory view showing one embodiment of a method for producing a synthetic resin molded article of the present invention.

FIG. 3 is an explanatory view showing one embodiment of a method for producing a laminate material of the present invention.

[Explanation of symbols]

 1) Acrylic resin plate (inner layer material), 2) Vacuum forming mold (female mold), 3) Male mold (moving mold) of injection compression molding machine, 4) Thermoplastic resin, 5) Injection compression molding Female mold (fixed mold) of machine, 6mm gate of injection compression molding machine. 20a laminated material, 20a transparent resin sheet (inner layer material), 20b protective sheet, 20c adhesive layer, 20d adhesive layer, 20e backing resin sheet.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) B29K 27:06 B29K 27:06 33:00 33:00 55:02 55:02 67:00 67:00 105 : 04 105: 04 105: 12 105: 12 105: 16 105: 16 B29L 9:00 B29L 9:00 F term (reference) 2D032 AA00 AB03 2E162 CD04 CD11 4F206 AA04C AA11C AA13C AA15C AA21C AA24C AB02 AB11 AB16 AB25 AD05 AD20 AD27 AG03 AG20 AH49 JA03 JA07 JB12 JB13 JF05 JN33

Claims (27)

[Claims] 1. An inner layer material made of a transparent resin sheet and a heated and melted thermoplastic resin colored and decorated on the back side of the inner layer material are injected, and compression molded while contacting the inner layer material. And an outer layer material. 2. The synthetic resin molded article according to claim 1, wherein the inner layer material is shaped as a surface side of the molded article. 3. The transparent resin sheet is made of acrylic resin, PE
T resin, AS resin, PVC resin, PP resin, PE resin,
The synthetic resin molded article according to claim 1, which is a sheet selected from an ABS resin and a PS resin. 4. The thermoplastic resin forming the outer layer material is an acrylic resin, a PET resin, an AS resin, a PVC resin, a PP resin.
The synthetic resin molded article according to claim 1, wherein the molded article is a resin selected from a resin, a PE resin, an ABS resin, and a PS resin. 5. The synthetic resin molded article according to claim 1, wherein the thermoplastic resin forming the outer layer material has a melt flow rate of 2 or more. 6. The synthetic resin molded article according to claim 1, wherein the thermoplastic resin forming the outer layer material is colored and decorated with an inorganic filler. 7. The synthetic resin molded article according to claim 1, wherein the thermoplastic resin forming the outer layer material has a porous structure. 8. The synthetic resin molded article according to claim 1, wherein the thermoplastic resin forming the outer layer material is reinforced with glass fibers. 9. The synthetic resin molded article according to claim 1, wherein an adhesive layer is interposed between the transparent resin sheet and the thermoplastic resin. 10. The synthetic resin molded article according to claim 1, wherein the surface of the transparent resin sheet exhibits water repellency. 11. A transparent resin sheet exhibiting water repellency, the surface of which is coated with a silicone compound, or a silicone resin.
The molded article made of synthetic resin according to claim 10, wherein the transparent resin sheet containing the compound is further laminated. 12. A transparent resin sheet exhibiting water repellency, the surface of which is coated with a fluorine compound, or the transparent resin sheet containing a fluorine compound is laminated on the surface. Item 11. The synthetic resin molded article according to Item 10. 13. A sheet of transparent resin to obtain an inner layer material, and the inner layer material is set in a mold of an injection compression molding machine so as to be on the surface side of a synthetic resin molded article from which the inner layer material is obtained. A thermoplastic resin in which a coloring agent heated and melted is mixed is injected, and then the injected thermoplastic resin is compressed in a state where the inner layer material is set, and the inner layer material and the thermoplastic resin are bonded. A method for producing a molded article made of synthetic resin, characterized in that a colored and decorated outer layer material is formed by the above method. 14. The method for producing a synthetic resin molded article according to claim 13, wherein the inner layer material is shaped as the surface side of the molded article. 15. The method according to claim 13, wherein a protective sheet is laminated on the transparent resin sheet with an adhesive. 16. The method according to claim 15, wherein the protective sheet is a resin softer than the transparent resin sheet. 17. The protection sheet according to claim 1, wherein the protection sheet is a PE resin.
7. The method for producing a synthetic resin molded article according to 6. 18. The transparent resin sheet is made of acrylic resin, P
The method for producing a synthetic resin molded article according to claim 13, wherein the sheet is a sheet selected from an ET resin, an AS resin, a PVC resin, a PP resin, a PE resin, an ABS resin, and a PS resin. 19. The thermoplastic resin forming the outer surface layer material,
Acrylic resin, PET resin, AS resin, PVC resin, P
The method according to claim 13, wherein the resin is a resin selected from the group consisting of a P resin, a PE resin, an ABS resin, and a PS resin. 20. The thermoplastic resin forming the outer layer material has a melt flow rate of 2 or more.
A method for producing the synthetic resin molded article according to the above. 21. The method for producing a synthetic resin molded article according to claim 13, wherein a foaming agent is blended with the thermoplastic resin forming the outer layer material. 22. The method for producing a synthetic resin molded article according to claim 13, wherein an inorganic filler is blended with the thermoplastic resin forming the outer layer material, and the thermoplastic resin is colored and decorated. 23. The method for producing a synthetic resin molded article according to claim 13, wherein glass fibers are blended with the thermoplastic resin forming the outer layer material. 24. The method according to claim 13, wherein the injection and compression of the thermoplastic resin are performed simultaneously. 25. The method according to claim 13, wherein the transparent resin sheet constituting the inner layer material is uncrosslinked or partially crosslinked. 26. The method according to claim 13, wherein an adhesive layer is interposed between the transparent resin sheet and the thermoplastic resin. 27. The method according to claim 13, wherein the injection molding machine is a vertical type or a horizontal type.