JP2963083B2 - Method for producing patterned foam molded article and patterned foam molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a patterned foam molded article and a patterned foam molded article obtained by the production method.

[0002]

2. Description of the Related Art Conventionally, foamed moldings having a surface such as marble or a three-dimensional pattern such as wood grain or embossing on the surface are lightweight, excellent in heat resistance, and excellent in design. It is used in various fields as a substitute for metal plates and stones. This type of patterned foam molded article is
It is manufactured by continuously extruding and foaming a composition in which a foaming agent is blended with a base resin such as polyvinyl chloride, and then performing painting, printing, sheet sticking or embossing on the surface. However, in such a conventional method, not only additional processing is required after molding, but also when the patterned surface layer is used as a building material, etc., due to the implementation work and outdoor exposure after the implementation. There is a problem of weather resistance and water resistance such as discoloration, fading, deterioration, peeling, and disappearing due to light, temperature change, moisture, etc., and it is not suitable for use outdoors, around water, long-term use, etc. is there. In addition, there is also a method in which a pattern is made by processing into a molding die, but only the same pattern is made to appear, and a dedicated mold is required, and the pattern is formed by unevenness on the surface. In addition, patterns tend to disappear.

In recent years, a method of three-dimensionally giving a grain or marble pattern to the surface of a low-foaming molded article by adopting a special structure at the tip of an extruder screw or a die head has been adopted. However, not only does it require a foam molding device with a special structure, but it also forms patterns such as simple curves and straight lines due to the unevenness of the surface. It is difficult to make various patterns appear.

[0004] Relatively recently, a resin composition for decorating / surface layer containing flaky powder and a resin composition for inner layer containing foaming agent are combined in a molten state using separate extruders, respectively . coextruded into a sizing die, provides low foaming molded within said sizing die, but also a method of producing a patterned foamed molded have been developed,
The surface of the foamed molded article obtained by this method has no gloss and its use is limited due to poor appearance. Furthermore, recently, it has become clear that the use of polyvinyl chloride as a material is not preferable because dioxin and the like are generated at the time of disposal of the product.
However, the above-mentioned patterned foamed moldings, which are lightweight, heat-insulating and excellent in design, are coming to the interior and exterior fields, as well as home appliances and sundries in various fields. What is excellent in weather resistance is required.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has excellent robustness, water resistance, chemical resistance, and weather resistance, and has complex and various patterns. It is another object of the present invention to provide a patterned foamed molded product having a beautiful glossy surface layer.

[0006]

SUMMARY OF THE INVENTION The present invention provides a transparent resin for a surface layer containing a thermoplastic resin, a resin composition for a decorative / middle layer containing a flaky powder and a thermoplastic resin, and an inner layer containing a foaming agent. The thermoplastic resin compositions are joined together in a molten state using separate extruders and sizing
The present invention provides a method for producing a patterned foam molded article, which is co-extruded into a die and performs low foam integral molding in the sizing die , and a patterned foam molded article obtained by the production method.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermoplastic resin contained in the resin for the surface layer used in the present invention includes polycarbonate,
ABS resin, AS resin, acrylic resin such as AAS resin or polystyrene resin, etc., and the gloss, transparency, strength, weather resistance, water resistance, chemical resistance,
Acrylic resin is particularly preferred from the viewpoint of easy handling. Examples of the acrylic resin used in the present invention include polymethyl methacrylate, methyl methacrylate-butyl acrylate copolymer, and methacrylic acid ester polymers and copolymers such as methyl methacrylate-styrene copolymer. Specifically, Sebian MAS10, MAS20, MAS3, which is a methyl methacrylate-styrene resin manufactured by Daicel Chemical Industries, Ltd.
0, Sumipec LG, MG, MH, methacrylic resin manufactured by Sumitomo Chemical Co., Ltd., GP10, GP20, GP31, polystyrene manufactured by Daicel Chemical Industries, Ltd.
And the like. The above thermoplastic resins can be used alone or in combination of two or more. By using these resins, the patterned foam molded article of the present invention obtained has a transparent surface, excellent gloss, no discoloration or deterioration, and excellent fastness, water resistance and chemical resistance. And weather resistance.

The flaky powder contained in the decorative / middle layer resin composition used in the present invention is, for example, calcium carbonate, calcium silicate, clay, kaolin, talc, silica, diatomaceous earth. Flaky inorganic powder such as mica, asbestos, barium sulfate, aluminum sulfate, calcium sulfate, magnesium carbonate, molybdenum disulfide, glass fiber, glass sphere, shirasu balloon, graphite, flaky metal powder such as alumina, copper, etc. Flaky hard-to-melt synthetic resin powders such as thermosetting resins (epoxy resins, unsaturated polyester resins, etc.) are exemplified. By changing the type of flaky powder contained in the decorative / middle layer resin composition, various patterns can be exhibited in the decorative / middle layer portion. For example, to produce patterns such as granite or marble, colored inorganic powder or flake-like or fibrous hard-to-melt synthetic resin materials can be used. It can show a typical pattern. The flaky powder can be used alone or as a mixture of two or more.

The particle size (weight average particle size) of the flaky powder is usually 50 to 1,800 μm, preferably 150 to 1,7 μm.
When the thickness is less than 50 μm, the pattern does not sufficiently appear on the surface of the foamed molded product, and on the other hand, 1,800 μm
Exceeding the limit causes clogging of the extrusion slit, resulting in ejection failure.

The compounding amount of the flaky powder is usually from 0.05 to 4% by weight, preferably from 0.1 to 3% by weight, and preferably less than 0.05% by weight in the decorative / middle layer resin composition. In the case of, it is difficult to obtain a desired pattern on the surface of the decorative / middle layer.
When the content is more than 10% by weight, not only the decorative / middle layer portion is easily peeled off from the inner layer foam, but also it becomes difficult to pelletize the decorative / middle layer resin composition.

The thermoplastic resin contained in the decorative / middle layer resin composition by mixing the above flaky powder includes ABS resin, AS resin, AAS resin, polystyrene, styrene-methyl methacrylate copolymer, and styrene. -Styrene polymers such as butadiene copolymers and polystyrene resins such as copolymers, polymethyl methacrylate,
Examples include methacrylic acid ester polymers such as methyl methacrylate-butyl acrylate copolymers and acrylic resins such as copolymers. Preferably, the melt index (200 ° C., 5 kg load) 2 to 30 g /
A polystyrene resin for 10 minutes or an acrylic resin having a melt index of 1 to 10 g / 10 minutes, particularly preferably a polystyrene resin or methyl methacrylate-
GP10, GP20, GP, which are styrene resins, for example, polystyrene manufactured by Daicel Chemical Industries, Ltd.
31 and Sebian MAS 10, MAS 20, MAS which are methyl methacrylate-styrene resins manufactured by the company
30 and the like. The above thermoplastic resins can be used alone or in combination of two or more. By using these resins, the patterned foamed molded article exhibits excellent robustness, water resistance, chemical resistance, and weather resistance without undergoing discoloration or deterioration.

Further, examples of the thermoplastic resin contained in the thermoplastic resin composition for the inner layer include polystyrene resins such as polycarbonate, acrylic resin, ABS resin, AS resin, and AAS resin. Resin. As polystyrene resin,
Examples include ABS resins, AS resins, AAS resins, and the like, and polymers and copolymers of styrene such as polystyrene, styrene-methyl methacrylate copolymer, and styrene-butadiene copolymer. The above thermoplastic resins can be used alone or in combination of two or more. Examples of the foaming agent contained in the thermoplastic resin composition for the inner layer include solid foaming agents such as sodium bicarbonate, ammonium carbonate, azodicarbonamide, and benzenesulfonyl hydrazide.
The above foaming agents can be used alone or
Mixtures of more than one species can be used. The compounding ratio of the foaming agent is usually 0.1 to 1 in the thermoplastic resin composition for the inner layer.
0% by weight, preferably 0.2 to 5% by weight. 0.1
If the amount is less than 10% by weight, the foaming is insufficient.
When the ratio exceeds, the expansion ratio is too high, and problems such as defoaming and surface roughening occur.

The above-mentioned resin for the surface layer, the resin composition for the decorating / middle layer containing the flaky powder, and the thermoplastic resin composition for the inner layer containing the foaming agent include a known lubricant, softener and inorganic filler, respectively. Colorants, heat stabilizers, antistatic agents, weathering stabilizers, antioxidants, antibacterial agents, fungicides, cellulosic substances such as wood flour, etc. can be added and mixed as appropriate. The above surface layer resin, decorative / middle layer resin composition, and inner layer thermoplastic resin composition are usually formed into pellets in advance, and then subjected to the following coextrusion processing.

As the co-extrusion apparatus, any one conventionally used for producing a co-extrusion molding of plastic can be used. Particularly preferred devices include a single extruder for extruding a surface layer resin, a single extruder for extruding a decorative / middle layer resin composition, and a single extruder for extruding an inner layer thermoplastic resin composition. Cerca process deformed extrusion mold,
That is, a die and a sizing die .

The extrusion temperature is selected depending on the type and composition of the composition to be extruded.
0-300 ° C. The thermoplastic resin composition for the inner layer extruded in a molten state from the extruder is simultaneously discharged to the die , and heat-fused with the resin composition for a decorating / middle layer extruded in a molten state from another extruder, Further decoration
The resin composition for the middle layer is heat-sealed with the resin for the surface layer extruded in a molten state from another extruder, and is integrally molded into a desired form.

In this case, the thickness of the surface layer, the decorative / middle layer, and the inner layer is not particularly limited.
It is preferable that the thickness of the decorative / middle layer is about 0.2 to 2 mm, and the thickness of the inner layer is about 3 to 50 mm. The extrusion amount and the take-off speed are not particularly limited, but are usually 5 to 100 kg / hour and 0.3 to 3 m / minute, respectively. The expansion ratio of the inner layer is usually about 1.2 to 4 times.

As described above, a patterned foam molded article having a three-layer structure of the surface layer resin, the decorative / middle layer resin composition, and the inner layer thermoplastic resin composition can be obtained.
The foamed molded article of the present invention has a transparent and glossy surface, is robust, is water-resistant, has excellent chemical and weather resistance, and is therefore excellent in various interior / exterior fields, particularly in the building materials field, sanitary field, furniture and tableware, and the like. It can be used as various components in the field of furniture, home appliances and miscellaneous goods.

[0018]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples (and comparative examples), but the present invention is not limited thereto. In Examples and Comparative Examples,
Various measurement items followed the following.

Surface appearance of molded article The surface condition of the molded article was visually evaluated according to the following evaluation criteria. ；: Smooth, transparent, good appearance ×: Irregular or opaque, poor appearance hardness test Pencil hardness was measured based on JIS K5400.

Water was dropped on the surface of the water- resistant molded article, and after standing for 5 days, the surface condition was visually evaluated according to the following evaluation criteria. ；: No change in surface, good appearance ×: surface swells to form wrinkles, poor appearance 5% hydrochloric acid was dropped on the surface of the chemically resistant molded article, and the surface condition after standing for 24 hours was evaluated according to the following evaluation criteria. Was visually evaluated according to the following. ○: no change in surface, good appearance ×: surface swells to form wrinkles, poor appearance, weather resistance Sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd.)
, A weather resistance test was conducted under conditions of a black panel temperature of 63 ° C. and rainfall, and the surface state of the molded article after 100 hours was visually evaluated according to the following evaluation criteria. ；: Very good appearance without surface change ×: Irregular appearance, discoloration, opacity, etc. on the surface, resulting in poor appearance

Example 1 An acrylic resin (Sebian MAS20, manufactured by Daicel Chemical Industries, Ltd.) was used as a resin for the surface layer. A resin composition in which 1 g of colored alumina oxide as a flaky powder was uniformly dispersed in 100 g of a polystyrene resin (GP31, manufactured by Daicel Chemical Industries, Ltd.) as a decorative / middle layer resin composition was extruded into a pellet form. Was used.
As the thermoplastic resin composition for the inner layer, 0.7% by weight of azodicarbonamide was dry-blended with a polystyrene resin (GP31, manufactured by Daicel Chemical Industries, Ltd.) to prepare a pellet-shaped resin composition. As co-extrusion molding equipment, for the surface layer, decorative / middle layer, and inner layer, a single extruder is used for each of the CELCA process profile extrusion machine ,
A die and a sizing die were used. Acrylic resin for surface layer, pellet-shaped decoration
The resin composition for the middle layer and the thermoplastic resin composition for the inner layer in the form of pellets were respectively supplied, and co-extrusion was carried out according to a conventional method to produce a flat foamed molded article having a three-layer structure. The molded article surface appearance, hardness, water resistance, and chemical resistance were evaluated by the above evaluation methods. Table 1 shows the conditions of the coextrusion molding and the evaluation results of the obtained foamed molded product.

Example 2 The same operation as in Example 1 was carried out except that an acrylic resin (Sebian MAS20, manufactured by Daicel Chemical Industries, Ltd.) was used as the resin composition for the decorating / middle layer, and the resin composition had a three-layer structure. A flat foam molded article was produced. The surface appearance, hardness, water resistance and chemical resistance of the molded product were evaluated in the same manner as in Example 1. Table 1 shows the conditions of the coextrusion molding and the evaluation results of the obtained foamed molded product.

Comparative Example 1 An acrylic resin (Sebian MAS20, manufactured by Daicel Chemical Industries, Ltd.) 100 was used as a decorative / surface layer resin composition.
A resin composition in which 1 g of colored alumina oxide was uniformly dispersed as flaky powder and extruded into a pellet form was used. As the thermoplastic resin composition for the inner layer, a polystyrene resin (available from Daicel Chemical Industries, Ltd., GP
31) Azodicarbonamide was dry-blended with 0.7% by weight to prepare a pellet-shaped resin composition. The co-extrusion apparatus, decorative-surface layer, using the inner-layer co single extruder, Cerca process variant extruder (da
Chairs and sizing dies ). The above-mentioned pellet-shaped acrylic resin for decorating and surface layer and the thermoplastic resin composition for the pellet-shaped inner layer are supplied to each single extruder, and co-extrusion molding is performed according to a conventional method to obtain a two-layer flat plate foam molding. Body manufactured. The molded article surface appearance, hardness, water resistance, and chemical resistance were evaluated by the above evaluation methods. Table 1 shows the conditions of the coextrusion molding and the evaluation results of the obtained foamed molded product.

[0024]

[Table 1]

[0025]

The foamed molded article obtained by the present invention has a complex three-layered structure in which the surface layer, the decorative / middle layer, and the low-foaming inner layer are integrated by heat fusion. Due to its structure, the surface is transparent, glossy, robust, and excellent in water resistance, chemical resistance, and weather resistance.
In particular, it can be used as various materials in the fields of building materials, sanitary, furniture and tableware, as well as in the field of home appliances and sundries.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 B29C 47/00-47/96 B29C 67/20-67/24

Claims (2)

(57) [Claims] 1. A resin for a transparent surface layer containing a thermoplastic resin, a resin composition for a decorative / middle layer containing a flaky powder and a thermoplastic resin, and a thermoplastic resin composition for an inner layer containing a foaming agent, respectively. A method for producing a patterned foam molded article, comprising: merging in a molten state using separate extruders, coextruding into a sizing die , and performing low-foam integral molding in the sizing die . 2. A patterned foam molded article obtained by the method according to claim 1.