JPH07290658A - Styrenic resin multilayered sheet molded article - Google Patents

Abstract

PURPOSE:To provide a styrenic resin multilayered sheet molded article excellent in fire retardancy, light fastness and cost performance. CONSTITUTION:A multilayered sheet molded article is obtained by laminating a methacrylic resin film with a thickness of 10-300mum to a laminate obtained by the co-extrusion of a polystyrenic resin and at least one layer of an adhesive resin.

Description

Detailed Description of the Invention

[0001]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a styrenic resin multilayer sheet molded article which is excellent in flame retardancy, light resistance and cost performance.

[0003]

2. Description of the Related Art At present, polyvinyl chloride resin, polycarbonate resin and methacrylic resin are used for indicator lamps and lighting covers. Polyvinyl chloride resin is used in various fields because it has an excellent balance of physical properties such as chemical resistance, light resistance, mechanical strength, and transparency, is easy to mold, and is inexpensive. When particularly high light resistance is required, a methacrylic resin film is laminated on both sides or one side of a single sheet of polyvinyl chloride resin so as to have almost the same light resistance as the methacrylic resin. I can do things. However, in recent years, polyvinyl chloride has been sought after in the world due to environmental problems, and various alternative materials for polyvinyl chloride resin have been studied. Methacrylic resin is particularly excellent in transparency and light resistance, but has the drawbacks of low mechanical strength (impact strength) and higher cost than polyvinyl chloride resin. Polycarbonate resin is excellent in mechanical strength (impact strength), and in terms of light resistance, a methacrylic resin film is used on both sides or one side of a single sheet of polycarbonate resin as with polyvinyl chloride resin. By laminating the resin, it is possible to provide the same light resistance as the methacrylic resin. However, the polycarbonate resin, like the methacrylic resin, has the disadvantage that it is more expensive than the polyvinyl chloride resin.

[0004]

As described above, polyvinyl chloride resin, polycarbonate resin and methacrylic resin are used for indicator lights and lighting covers. With the call for de-vinyl chloride, various alternative materials for polyvinyl chloride resin are being investigated.

Although methacrylic resin is excellent in transparency and light resistance, it has disadvantages that it has low mechanical strength (impact strength) and its cost is higher than that of polyvinyl chloride resin. Therefore, in terms of cost and strength, methacrylic resin cannot be a complete substitute for polyvinyl chloride resin. Polycarbonate resins also have no problems in physical properties, but they are more expensive than polyvinyl chloride resins and cannot be completely replaced with polyvinyl chloride resins. Polycarbonate resin and methacrylic resin have no problem in light resistance, but cannot be used as a substitute material for polyvinyl chloride resin in terms of cost.

Candidates for alternative materials to polyvinyl chloride resin are
From the viewpoint of cost, it is narrowed down to polyethylene resin, polypropylene resin, and polystyrene resin, which are called general-purpose resins. Among these resins, the resin having the most suitable physical properties for indicator lights and lighting covers is polystyrene. Polystyrene resin has excellent moldability and cost is low, but
There is a problem with light resistance. Although there is a method of adding an ultraviolet absorber or a hindered phenol type light stabilizer, it is not possible to obtain sufficient light resistance equivalent to that of a methacrylic resin only by adding such a stabilizer. Further, the improvement of the light resistance of the methacrylic resin film by laminating, in the case of polystyrene resin, has a problem in the adhesiveness with the methacrylic resin film, and polystyrene resin is also insufficient as a material for indicator lights and lighting covers. It was In addition, a multilayer sheet molded product obtained by laminating an acrylic film on a blend of a styrene resin and a styrene-methyl methacrylate copolymer resin has a light resistance equivalent to that of a methacrylic resin, and therefore has a methacrylic resin or a polycarbonate. There is a possibility that it can be an alternative material of polyvinyl chloride resin, which is cheaper than the binder resin. However, in this method, unless the styrene-methyl methacrylate copolymer resin is used in an amount of 10 parts by weight or more with respect to 90 parts by weight of the styrene resin, the adhesiveness is poor and the cost is still high. Therefore, as an alternative material of polyvinyl chloride resin,
Materials that are inexpensive and have excellent light resistance are required.

[0007]

DISCLOSURE OF THE INVENTION As a result of earnest research on materials for indicator lights and lighting covers, the present inventor has found that a laminate obtained by coextruding a polystyrene resin and at least one kind of adhesive resin In addition, the multilayer sheet molded product obtained by laminating the methacrylic resin film has moldability,
The present invention has been completed by discovering that it is optimal as a material for indicator lamps and lighting covers in view of light resistance and cost.

That is, the present invention is a multilayer obtained by laminating a methacrylic resin film having a thickness of 10 to 300 μm on a laminate obtained by coextruding a polystyrene resin and at least one or more adhesive resins. It is to provide a sheet molded product.

The polystyrene resin used in the present invention means a styrene homopolymer (GPPS), a polybutadiene rubber and / or a styrene-butadiene copolymer graft polymer (HIP).
S) and mixtures thereof. Also, if necessary, SB
S (styrene-butadiene-styrene block copolymer), SEBS (styrene-butylene-ethylene-styrene block copolymer) or SIS (styrene-isoprene-styrene block copolymer) may be added.

The methacrylic resin used in the present invention is a polymer or copolymer containing various esters of methacrylic acid as a main component, and specifically, methyl methacrylate, ethyl methacrylate, butyl methacrylate, etc. Are homopolymers and copolymers of various methacrylic acid esters, and copolymers of these methacrylic acid esters with various acrylic acid esters, acrylic acid, styrene, α-methylstyrene and the like. The methacrylic resin film is manufactured by a known manufacturing method, for example, the T-die method,
It can be manufactured by extrusion molding such as the inflation method. The thickness of the film is 10 to 300 μm, and if it is less than 10 μm, the workability during extrusion molding or laminating is poor, and if it exceeds 300 μm, the cost is increased, which is not preferable. By laminating a methacrylic resin film on a styrene resin, the light resistance is greatly improved. Further, in order to improve the light resistance, an ultraviolet absorber or a hindered amine light stabilizer may be added. Examples of the ultraviolet absorber used in the present invention include benzotriazole compounds, benzophenone compounds, and phenyl salicylate compounds.

The adhesive resin used in the present invention is to increase the adhesive strength between the polystyrene resin which is the base material of the multilayer sheet molding and the methacrylic resin film which is the laminate material. It is a resin that has a role of adhesion, such as styrene-methyl methacrylate copolymer resin (MS resin) or a blend of polystyrene resin and / or methacrylic resin and styrene-methyl methacrylate copolymer resin (MS resin). is there. When the adhesive resin is a single layer, the adhesive resin contains styrene units of 95 to 40.
By weight, the methyl methacrylate unit is composed of 5 to 60 parts by weight, preferably the styrene unit is composed of 95 to 70 parts by weight, and the methyl methacrylate unit is composed of 5 to 30 parts by weight. When the styrene unit is less than 40 parts by weight, the adhesiveness between the polystyrene resin and the adhesive resin is lowered during coextrusion, and sufficient adhesive strength cannot be obtained, which is not preferable. On the other hand, when the styrene unit exceeds 95 parts by weight, the adhesiveness between the methacrylic resin film and the adhesive resin is deteriorated when laminating, and sufficient adhesive strength cannot be obtained, which is not preferable.
If one layer of adhesive resin does not provide sufficient adhesive strength, co-extrude two or more layers of adhesive resin on polystyrene resin to increase the adhesive strength between polystyrene resin and methacrylic resin film and adhesive resin. , One layer of adhesive resin from the polystyrene resin side, two layers, ..., N
1 part by weight of styrene units in the layer and coextruded adhesive resin
The second layer, the third layer, and so on have the largest number of layers, and the weight part of the styrene unit in the adhesive resin decreases as the layers increase. When the resin film is laminated, the adhesive resin of each layer is blended so as to have sufficient adhesive strength and to obtain sufficient adhesive strength between the adhesive resin layers. At this time, the adhesive resin on the polystyrene resin side contained 99 to 40 parts by weight of styrene units and 1 unit of methyl methacrylate units.
To 60 parts by weight, preferably 99 to 70 parts by weight of styrene units and 1 to 3 of methyl methacrylate units.
0 to 20 parts by weight, more preferably 99 to 80 parts by weight of styrene unit and 1 to 1 of methyl methacrylate unit.
It is composed of 20 parts by weight. When the styrene unit in the adhesive resin is less than 40 parts by weight, the adhesiveness between the polystyrene-based resin and the adhesive resin decreases during coextrusion, and sufficient adhesive strength cannot be obtained, which is not preferable. The adhesive resin on the methacrylic resin film side is composed of 95 to 1 parts by weight of styrene units and 5 to 99 parts by weight of methyl methacrylate units, preferably 90 to 1 parts by weight of styrene units and methyl methacrylate units. Is composed of 10 to 99 parts by weight, more preferably 80 to 1 parts by weight of styrene unit and 20 to 99 parts by weight of methyl methacrylate unit. The methyl methacrylate unit in the adhesive resin is 5
When the amount is less than the weight part, the adhesiveness between the methacrylic resin film and the adhesive resin is deteriorated when laminating, and sufficient adhesive strength cannot be obtained, which is not preferable. The laminate obtained by co-extruding the polystyrene resin and at least one or more adhesive resins is composed of 50 to 99 parts by weight of styrene units and 50 to 1 parts by weight of methyl methacrylate units.
When the methyl methacrylate unit in the coextrusion laminate exceeds 50 parts by weight, the cost becomes high and it is not preferable as a substitute for the polyvinyl chloride resin. The methyl methacrylate unit in the laminate is preferably 30 parts by weight or less, more preferably 10 parts by weight or less. The thickness of each layer of the coextrusion laminate is preferably 10 microns or more. When the layer thickness is less than 10 microns, workability during coextrusion becomes poor,
Not preferable. The coextruded laminate obtained by coextrusion in this way has a sufficiently high adhesive strength between the respective layers, and has sufficient adhesiveness with the methacrylic resin film which is a laminating material, so that it can be laminated to a laminate. The obtained multi-layered sheet molded article has excellent light resistance and is inexpensive, and thus is sufficiently useful as a substitute for the polyvinyl chloride resin.

The halogen-based flame retardant used in the present invention is an organic compound containing halogen, such as tetrabromobisphenol A, TBA carbonate oligomer, brominated bisphenol A type epoxy polymer, decabromodiphenyl ether, bis (tribromophenoxy). ) Ethane, perchlorochloropentadecane, hexabromocyclododecane, tris (tribromoneopentyl) phosphate, etc., and 1 to 2 of these are added to the styrene resin, or a mixture of 2 or more thereof is added to the styrene resin.
0 parts by weight, particularly 1 to 10 parts by weight is preferred. Addition amount is 20
If it exceeds the weight part, the light transmittance decreases, and it is difficult to obtain a desired light diffusing performance for a lighting cover or an indicator light. As the flame retardant, hexabromocyclododecane, which is particularly effective in a small amount, is desirable.

If necessary, 0 to 5 parts by weight of antimony trioxide can be added as a flame retardant aid. Also with respect to antimony trioxide, if the amount added exceeds 5 parts by weight, the light transmittance decreases, and it is difficult to obtain the desired light diffusion performance for a lighting cover or a display lamp.

The light diffusing agent used in the present invention is
Glass, silica, barium carbonate, barium sulfate, quartz,
Examples of fine particles of aluminum hydroxide, calcium carbonate, zinc oxide, titanium oxide and the like, and various organic polymers include crosslinked polymers.

The amount of the light diffusing agent added is 100% styrene resin.
0 to 1 part by weight is preferable with respect to parts by weight, and if it exceeds 1 part by weight, the light transmittance decreases, which is not preferable.

If desired, an antioxidant, a heat stabilizer, a dye and a pigment may be added. The multilayer sheet molded product of the present invention is a laminate in which an adhesive resin is coextruded on one side of a polystyrene resin. Not only a multilayer sheet molded article obtained by laminating a methacrylic resin film having a thickness of 10 to 300 μm on the adhesive resin side of a product, but also a laminate obtained by co-extruding an adhesive resin on both sides of a polystyrene resin. A multi-layer sheet obtained by laminating a methacrylic resin film having a thickness of 10 to 300 μm on both sides of the sheet.
Also includes molded products.

Coextrusion and laminating can be carried out by known methods. That is, multi-maniphone
A co-extrusion is carried out by a soldering method, a feed block method or a multi-slot method, and an acrylic resin film is laminated on the laminate obtained by the co-extrusion. The laminate is preferably a method using extrusion laminate.

[0018]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Examples 1 to 2 Polystyrene resin (90 parts by weight of GPPS and 10 parts by weight of HIPS) and adhesive resin (GPP)
A blend of 30 parts by weight of S and 70 parts by weight of a styrene-methyl methacrylate copolymer resin having 30% of methyl methacrylate units and 70% of styrene units, or 20% of methyl methacrylate units and 80% of styrene units. A styrene-methyl methacrylate copolymer resin) with a multi-slot method to form a polystyrene resin layer of 2 mm,
The co-extruded laminated sheet was molded so that the adhesive resin layer had a thickness of 0.2 mm, and this laminated sheet was subjected to the first cooling roll.
A 50-micron-thick methacrylic resin film (Acryprene HBS, manufactured by Mitsubishi Rayon Co., Ltd.) was laminated on one side of the sheet to obtain a multilayer sheet molded product. However, melting temperature 220 ° C, adapter temperature 220 ° C, die temperature 2
Coextrusion and laminating were performed under the conditions of 25 ° C and a roll temperature of 90 ° C. The light resistance and the adhesiveness between the methacrylic resin film and the adhesive resin or between the polystyrene resin and the adhesive resin were evaluated by a cross-cut test. The evaluation results are shown in Table 1.

Example 3 Polystyrene resin (90 parts by weight of GPPS and 10 parts by weight of HIPS) was used as a UV absorber.
Blended by adding 0.2 parts by weight of TINUVIN 327 manufactured by the company, melted and kneaded by an extruder and pelletized), and adhesive resin (30 parts by weight of GPPS and 30% of methyl methacrylate unit, styrene unit) Of 70% by weight of a styrene-methyl methacrylate copolymer resin (70% by weight) by a multi-slot method so that the polystyrene resin layer has a thickness of 2 mm and the adhesive resin layer has a thickness of 0.2 mm. An extruded laminated sheet was formed, and a methacrylic resin film (Acryprene HBS, manufactured by Mitsubishi Rayon Co., Ltd.) having a thickness of 50 μm was laminated on one side of the laminated sheet with the first cooling roll. A multilayer sheet molded product was obtained. However, melting temperature 220 ℃, adapter-temperature 2
Coextrusion and laminating were performed under the conditions of 20 ° C, die temperature of 225 ° C, and roll temperature of 90 ° C. The light resistance of this multilayer sheet molded article and the adhesiveness between the methacrylic resin film and the adhesive resin or the polystyrene resin and the adhesive resin were evaluated in the same manner as in Examples 1 and 2. . The evaluation results are shown in Table 1.

Comparative Example 1 Polystyrene resin (a blend of 90 parts by weight of GPPS and 10 parts by weight of HIPS) was extruded into a sheet having a thickness of 2 mm, and this single-layer sheet was extruded with an initial cooling roll. Laminate a 50-micron thick methacrylic resin film (Acryprene HBS, manufactured by Mitsubishi Rayon Co., Ltd.) on one side.
To obtain a multilayer sheet molded product. However, the melting temperature 22
0 ℃, adapter-temperature 220 ℃, die temperature 225 ℃,
Co-extrusion and lamination were carried out under the conditions of a roll temperature of 90 ° C. At this time, the adhesion between the polystyrene resin and the methacrylic resin film was evaluated by the same method as shown in Examples 1-2. The evaluation results are shown in Table 1.

Comparative Example 2 The light resistance of a single layer sheet obtained by extruding a polystyrene resin (90 parts by weight of GPPS and 10 parts by weight of HIPS) to a thickness of 2 mm is shown in Examples 1 and 2. It evaluated by the same method. However, melting temperature 220 ° C, adapter temperature 220 ° C, die temperature 225 ° C, roll temperature 9
Co-extrusion and lamination were carried out at 0 ° C.

Comparative Example 3 Polystyrene resin (a blend of 90 parts by weight of GPPS and 10 parts by weight of HIPS) and an adhesive resin (GPP)
A blend of 30 parts by weight of S and 70 parts by weight of a styrene-methyl methacrylate copolymer resin having 30% of methyl methacrylate units and 70% of styrene units, or 20% of methyl methacrylate units and 80% of styrene units. A styrene-methyl methacrylate copolymer resin) with a multi-slot method to form a polystyrene resin layer of 2 mm,
A coextrusion laminated sheet was molded so that the adhesive resin layer had a thickness of 0.2 mm. However, coextrusion was performed under the conditions of a melting temperature of 220 ° C, an adapter temperature of 220 ° C, a die temperature of 225 ° C, and a roll temperature of 90 ° C. This co-extrusion sheet
The light resistance of the molded product was evaluated by the same method as shown in Examples 1-2. The evaluation results are shown in Table 1.

[0024]

[Table 1]

[0025]

EFFECTS OF THE INVENTION By co-extruding an acrylic resin film with a polystyrene resin via an adhesive resin and simultaneously laminating it, a multilayer sheet molded product having good adhesiveness and good light resistance can be obtained. It is useful.

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Claims (7)

[Claims] 1. A laminate obtained by co-extruding a polystyrene-based resin and at least one or more adhesive resins,
A multilayer sheet molded product obtained by laminating a methacrylic resin film having a thickness of 300 microns. 2. The multilayer sheet according to claim 1, wherein the thickness of each layer of the laminate obtained by coextruding the polystyrene resin and at least one or more adhesive resins is 10 μm or more.
Molded product. 3. The polystyrene resin is GPPS (homopolystyrene) or HIPS (rubber reinforced polystyrene).
Alternatively, it is a blend of GPPS and HIPS, and the adhesive resin is styrene-methyl methacrylate copolymer resin (MS resin), or polystyrene resin and / or methacrylic resin and styrene-methyl methacrylate copolymer resin (MS resin). The multilayer sheet molded product according to claim 1 or 2, which is a blend with 4. The adhesive resin contains 50 to 99 styrene units.
By weight, the methyl methacrylate unit is composed of 50 to 1 part by weight, and the thickness of the polystyrene resin layer is 0.5 to
The multi-layered sheet molded product according to claim 1, 2 or 3, which has a size of 5 mm. 5. A polystyrene resin comprising 1 to 20 parts by weight of a halogen flame retardant and 0.01 to 1 parts by weight of a light diffusing agent, relative to 100 parts by weight of a polystyrene resin. The multi-layered sheet molded article according to claim 2 or claim 3 or claim 4. 6. The multilayer sheet molded article according to claim 5, wherein the halogen-based flame retardant is hexabromocyclododecane. 7. The total light transmittance at a thickness of 1 mm is 30 to 70%.
The multilayer sheet molded article according to claim 1, 2 or 3, 3 or 4 or 5 or 6.