JP2015003996A - Thermoplastic resin composition for extrusion molding and extruded molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition for extrusion molding which is excellent in not only weather resistance but also moldability and low whitening properties.SOLUTION: A thermoplastic resin composition comprises a graft copolymer (A) and a copolymer (B). The graft copolymer (A) is obtained by graft polymerization of a vinyl cyanide monomer and an aromatic vinyl monomer in the presence of an acrylic rubber-like polymer. The copolymer (B) is obtained by polymerization of an aromatic vinyl monomer and a vinyl cyanide monomer. In the acrylic rubber-like polymer existing in the thermoplastic resin composition, particles having a circle-equivalent particle diameter of 250 nm or more are contained in an amount of 10 wt.% or less based on the acrylic rubber-like polymer. The thermoplastic resin composition has a die swell ratio of 1.10 or more as measured at a shear rate of 100 (1/s) and at 200°C.

Description

  The present invention relates to a thermoplastic resin composition for extrusion which is excellent not only in weather resistance but also in molding processability, and further in low whitening property, and an extrusion molded body using the resin composition.

  ABS resin is a resin having an excellent balance between impact resistance and workability, and is used in a wide range of fields such as interior and exterior products for vehicles such as automobiles, housings for various home appliances and OA equipment, and other miscellaneous goods fields. That is, it is used not only for injection molding but also for extrusion molding as represented by sheet extrusion. However, the ABS resin has a disadvantage that it is inferior in weather resistance because the diene rubber polymer used as its rubber component is easily decomposed by ultraviolet rays or the like. However, weather resistance can be improved by using an acrylic material. Improved resin compositions are known (Patent Documents 1 and 2). However, although such a resin composition is excellent in weather resistance, there is a problem that molding processability is not sufficient.

JP 2000-212377 A

JP2007-291327A

  An object of the present invention is to provide a thermoplastic resin composition for extrusion molding which is excellent not only in weather resistance but also in molding processability and further in low whitening property.

  As a result of intensive studies to solve the problems of the prior art, the present inventors have found that the weight of particles having an equivalent-circle particle diameter of 250 nm or more with respect to the acrylic rubber-like polymer present in the thermoplastic resin composition. It has been found that the above object can be achieved when the ratio is not more than a specific amount and the thermoplastic resin composition has a specific die swell ratio, and the present invention has been achieved.

  That is, the present invention relates to a thermoplastic resin composition (graft copolymer (A) and copolymer (B) containing 20 to 90 parts by weight of graft copolymer (A) and 10 to 80 parts by weight of copolymer (B). ) And the graft copolymer (A) is in the presence of 10 to 80 parts by weight of an acrylic rubber-like polymer in the presence of a vinyl cyanide monomer and an aromatic vinyl monomer. And a graft copolymer (A) obtained by graft polymerization of 20 to 90 parts by weight of at least one monomer selected from the above and other vinyl monomers copolymerizable therewith, (B) is a copolymer (B) obtained by polymerizing an aromatic vinyl monomer and a vinyl cyanide monomer and, if necessary, other vinyl monomers that can be copolymerized. Related to the acrylic rubber-like polymer present in the thermoplastic resin composition. A die having a circle equivalent particle diameter of 250 nm or more is 10% by weight or less with respect to the acrylic rubber-like polymer, and measured at 200 ° C. and a shear rate of 100 (1 / sec) of the thermoplastic resin composition. The present invention relates to a thermoplastic resin composition for extrusion molding, wherein the well ratio is 1.10 or more.

  According to the present invention, it is possible to provide a thermoplastic resin composition for extrusion molding which is excellent not only in weather resistance but also in molding processability and further in whitening property, and an extrusion molded body obtained from the thermoplastic resin composition.

The present invention will be described in detail below.
The present invention relates to a thermoplastic resin composition for extrusion molding comprising 20 to 90 parts by weight of a graft copolymer (A) and 10 to 80 parts by weight of a copolymer (B) (graft copolymer (A) and copolymer ( The sum of B) is 100 parts by weight).

  The graft copolymer (A) used in the present invention comprises an aromatic vinyl monomer, a vinyl cyanide monomer and other vinyls copolymerizable with these in the presence of an acrylic rubber-like polymer. It is a graft copolymer obtained by graft polymerization of at least one monomer selected from system monomers.

  The acrylic rubbery polymer used in the present invention polymerizes a monomer (mixture) containing a (meth) acrylic acid ester monomer having an alkyl group having 1 to 16 carbon atoms in the presence of a crosslinking agent. Obtained. Examples of the (meth) acrylic acid ester monomer having 1 to 16 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and the like. The

  Examples of the crosslinking agent used in the acrylic rubbery polymer include divinylbenzene, allyl (meth) acrylate, ethylene glycol di (meth) acrylate, diallyl phthalate, dicyclopentadiene di (meth) acrylate, trimethylolpropane tri (meth) ) Acrylate, pentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, triallyl cyanurate, triallyl isocyanurate and the like.

  The acrylic rubber-like polymer is a copolymer having a C1-C16 (meth) acrylic acid ester monomer and other copolymerizable monomers, for example, conjugated diene, as long as the object of the present invention is not impaired. Examples thereof include monomers, aromatic vinyl monomers, and vinyl cyanide monomers.

  Conjugated diene monomers include 1,3-butadiene, isoprene, 2-chloro-1,3-butadiene, chloroprene, 2-methyl-1,3-butadiene, and 2,3-dimethyl-1,3-butadiene. Etc.

  Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, paramethylstyrene, bromostyrene, and the like, and one or two or more types can be used. In particular, styrene and α-methylstyrene are preferable.

  Examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile and the like, and one or more of them can be used. Particularly preferred is acrylonitrile.

  The structure of the acrylic rubber-like polymer is not particularly limited, and may be, for example, a so-called composite rubber having a core layer and a shell layer, or may be a multilayer structure having three or more layers. The composite rubber includes a composite rubber obtained by polymerizing a (meth) acrylate monomer on a core layer obtained by polymerizing a monomer (mixture) containing an aromatic vinyl monomer, and a conjugated diene. Examples include a composite rubber having a shell layer obtained by polymerizing a (meth) acrylate monomer on a core layer obtained by polymerizing a monomer (mixture) containing a rubber-based polymer.

  There is no particular limitation on the weight average particle diameter of the acrylic rubber-like polymer used for the polymerization of the graft co-aggregate (A), but for the acrylic rubber-like polymer in the thermoplastic resin composition for extrusion molding, it is equivalent to a circle. It is necessary to control the particle size so that the particle size is 250 nm or more with respect to the acrylic rubber-like polymer. As a method for controlling the particle diameter of the acrylic rubbery polymer, any method may be used. For example, the type and amount of the emulsifier, the type and amount of the polymerization initiator, the addition rate of the monomer, etc. The method of changing is mentioned.

  Polymerization initiators used for polymerizing acrylic rubbery polymers include water-soluble polymerization initiators such as potassium persulfate, sodium persulfate, and ammonium persulfate, cumene hydroperoxide, benzoyl peroxide, and t-butyl hydro gen. Examples thereof include oil-soluble polymerization initiators such as peroxide, acetyl peroxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide. A reducing agent is used as necessary. Specific examples of the reducing agent include ferrous sulfate heptahydrate, sulfite, bisulfite, pyrosulfite, nitrite, nithionate, thio Sulfates, formaldehyde sulfonates, benzaldehyde sulfonates, carboxylic acids such as L-ascorbic acid, tartaric acid, citric acid, and reducing sugars such as lactose, dextrose, saccharose, dimethylaniline, triethanolamine, etc. Of these amines. Furthermore, examples of the chelating agent include tetrasodium pyrophosphate and sodium ethylenediaminetetraacetate.

  Examples of the emulsifier used in the polymerization include carboxylate, sulfate ester salt, sulfonate salt and the like. Specific examples of emulsifiers preferably used include potassium oleate, dipotassium alkenyl succinate, sodium rosinate, sodium dodecylbenzenesulfonate, and the like.

  The gel content in the toluene solvent of the acrylic rubbery polymer is not particularly limited, but from the viewpoint of balance of physical properties, the gel content of the acrylic rubbery polymer is preferably 75% or more, and 80% or more. It is more preferable that

  The graft copolymer (A) of the present invention comprises an aromatic vinyl monomer, a vinyl cyanide monomer, and other vinyls copolymerizable therewith in the presence of the acrylic rubber-like polymer described above. It is a graft copolymer obtained by graft polymerization of at least one monomer selected from the system monomers.

  Examples of the aromatic vinyl monomer constituting the graft copolymer (A) include styrene, α-methylstyrene, paramethylstyrene, bromostyrene, and the like, and one or more of them can be used. In particular, styrene and α-methylstyrene are preferable.

  Examples of the vinyl cyanide monomer constituting the graft copolymer (A) include acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile and the like, and one or more of them can be used. Particularly preferred is acrylonitrile.

  Examples of other copolymerizable vinyl monomers constituting the graft copolymer (A) include (meth) acrylic acid ester monomers, maleimide monomers, amide monomers, and the like. 1 type, or 2 or more types can be used. (Meth) acrylic acid ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl acrylate, (meth) acrylic Examples include phenyl acid, 4-t-butylphenyl (meth) acrylate, (di) bromophenyl (meth) acrylic acid, chlorophenyl (meth) acrylate, and the maleimide monomer includes N-phenylmaleimide, N-cyclohexylmaleimide and the like can be exemplified, and examples of the amide monomer include acrylamide and methacrylamide.

  The graft copolymer (A) used in the present invention needs to contain 10 to 90 parts by weight of an acrylic rubber-like polymer in 100 parts by weight of the graft copolymer. If the acrylic rubber-like polymer is less than 10 parts by weight or exceeds 90 parts by weight, the moldability is inferior. The content of the acrylic rubbery polymer is preferably 30 to 80 parts by weight, and more preferably 40 to 70 parts by weight.

  There is no particular limitation on the composition ratio of the above-mentioned monomer that is graft-polymerized with the acrylic rubber-like polymer, but the aromatic vinyl monomer is 60 to 90% by weight, the vinyl cyanide monomer is 10 to 40% by weight. %, And a composition ratio of 0 to 30% by weight of other copolymerizable vinyl monomers, 30 to 80% by weight of aromatic vinyl monomers, and 20 to 70% by weight of (meth) acrylic acid ester monomers And a composition ratio of 0 to 50% by weight of another copolymerizable vinyl monomer, 20 to 70% by weight of an aromatic vinyl monomer, 20 to 70% by weight of a (meth) acrylate monomer, The composition ratio is preferably 10 to 60% by weight of a vinyl cyanide monomer and 0 to 30% by weight of another copolymerizable vinyl monomer.

  There is no restriction | limiting in particular in the method for superposing | polymerizing a graft copolymer (A), Well-known polymerization methods, such as an emulsion polymerization method, suspension polymerization method, and block polymerization method, can be used. When the emulsion polymerization method is used, a latex of the graft copolymer (A) can be obtained by graft polymerization of the above-mentioned monomer to the above-mentioned acrylic rubber-like polymer. The latex of the graft copolymer (A) is coagulated by a known method, and the powder of the graft copolymer (A) can be obtained through washing, dehydration, and drying steps.

  Graft ratio of the graft copolymer (A) (determined from the acetone-soluble and insoluble amounts of the graft copolymer and the weight of the acrylic rubber-like polymer in the graft copolymer), and the reduction of the acetone-soluble component. Viscosity (0.4 g / 100 cc, measured as N, N dimethylformamide solution at 30 ° C.) is not particularly limited, and any structure can be used depending on the required performance. From the viewpoint of balance of physical properties, the graft ratio Is preferably 5 to 150%, and the reduced viscosity is preferably 0.2 to 2.0 dl / g.

  The copolymer (B) used in the present invention is obtained by polymerizing an aromatic vinyl monomer and a vinyl cyanide monomer and, if necessary, other vinyl monomers that can be copolymerized. The resulting copolymer.

  As the aromatic vinyl monomer, vinyl cyanide monomer and other copolymerizable monomers constituting the copolymer (B), monomers used in the graft copolymer (A) The same can be used.

  The copolymer (B) used in the present invention can be polymerized by a conventionally known polymerization technique such as an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method or a solution polymerization method. The polymers obtained by the respective polymerization methods may be combined, or one or two or more types of copolymers having different polymerization methods and composition ratios may be combined.

  Although there is no restriction | limiting in particular in the ratio of each monomer which comprises a copolymer (B), When a total amount of the monomer which comprises a copolymer (B) is 100 weight part, it is a viewpoint of a physical-property balance. From 50 to 85 parts by weight of the aromatic vinyl monomer, from 15 to 50 parts by weight of the vinyl cyanide monomer, and from 0 to 35 parts by weight of the other copolymerizable monomer.

  The copolymer (B) used in the present invention is related to the molding processability when extruding the thermoplastic resin composition for extrusion molding, and the acrylic rubbery heavy in the thermoplastic resin composition for extrusion molding. It has a role of controlling the content of coalesce and die swell.

  With respect to the thermoplastic resin composition for extrusion molding of the present invention, the die swell ratio measured at 200 ° C. and a shear rate of 100 (1 / sec) needs to be 1.10 or more. When the die swell ratio is less than 1.10, the moldability during extrusion molding is inferior. The die swell ratio is preferably 1.15 or more, and more preferably 1.20 or more.

  As a method for adjusting the die swell ratio of the thermoplastic resin composition for extrusion molding, a method for adjusting the use ratio of the graft copolymer (A) and the copolymer (B), or a weight as the copolymer (B). Examples thereof include a method using two or more types of copolymers having different average molecular weights.

  The thermoplastic resin composition for extrusion molding of the present invention is 10% by weight or less of particles having an equivalent-circle particle diameter of 250 nm or more with respect to the acrylic rubber-like polymer with respect to the acrylic rubber-like polymer in the resin composition. It is necessary to be. When there are more particles than 10% by weight, the resulting resin composition has poor whitening properties. The particles are preferably 8% by weight or less, and more preferably 5% by weight or less. Further, even when two or more kinds of graft copolymers (A) having different weight average particle diameters of the acrylic rubber-like polymer are used, particles having an equivalent circle particle diameter of 250 nm or more are acrylic rubber-like. If it is 10 weight% or less with respect to a polymer, the resin composition excellent in the whitening property will be obtained.

  The thermoplastic resin composition for extrusion molding of the present invention has 20 to 90 parts by weight of the graft copolymer (A) when the total of the graft copolymer (A) and the copolymer (B) is 100 parts by weight. It is necessary that the copolymer (B) is used in an amount of 10 to 80 parts by weight. If the graft copolymer (A) is less than 20 parts by weight or exceeds 90 parts by weight, the moldability is inferior. The graft copolymer (A) is preferably 30 to 80 parts by weight, and the copolymer (B) is preferably 20 to 70 parts by weight. The graft copolymer (A) is preferably 40 to 70 parts by weight, More preferably, B) is 30 to 60 parts by weight.

  The thermoplastic resin composition for extrusion molding of the present invention comprises hindered amine-based light stabilizers, hindered phenol-based, sulfur-containing organic compound-based, phosphorus-containing organic compound-based antioxidants, phenol-based, acrylate as necessary. Heat stabilizers such as benzoate, benzotriazole, benzophenone, salicylate UV absorbers, organic nickel, lubricants such as higher fatty acid amides, plasticizers such as phosphate esters, polybromophenyl ether, Tetrabromobisphenol-A, brominated epoxy oligomers, halogenated compounds such as brominated compounds, phosphorus compounds, flame retardants and flame retardants such as antimony trioxide, odor masking agents, carbon black, titanium oxide, pigments, and Dye etc. can also be added. Furthermore, reinforcing agents and fillers such as talc, calcium carbonate, aluminum hydroxide, glass fiber, glass flake, glass bead, carbon fiber, and metal fiber can be added.

  The thermoplastic resin composition for extrusion molding can be used by mixing with other thermoplastic resins as necessary. Examples of such other thermoplastic resins that can be used include acrylic resins such as polymethyl methacrylate, polycarbonate resins, polybutylene terephthalate resins, polyethylene terephthalate resins, polyamide resins, and polylactic acid resins.

  The thermoplastic resin composition for extrusion molding of the present invention can be obtained by mixing the above-described components. In order to mix, well-known kneading apparatuses, such as an extruder, a roll, a Banbury mixer, a kneader, can be used, for example. Furthermore, various extruded products can be produced by a known extrusion method.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” and “%” are based on weight.

Production of butyl acrylate rubber latex (a-1) In a nitrogen-replaced glass reactor, 180 parts by weight of deionized water, 15 parts by weight of butyl acrylate, 0.1 parts by weight of allyl methacrylate, 0.36 parts by weight of dipotassium alkenyl succinate (Solid content conversion) 0.15 parts by weight of potassium persulfate was charged and reacted at 65 ° C. for 1 hour. Thereafter, an emulsifier aqueous solution in which 0.64 parts by weight of dipotassium alkenyl succinate (in terms of solid content) was dissolved in 85 parts by weight of butyl acrylate and 0.53 parts by weight of allyl methacrylate and 20 parts by weight of deionized water was added for 3 hours. Over time. After dropping, the mixture was held for 3 hours to obtain butyl acrylate rubber latex (a-1). Here, Latemulu ASK manufactured by Kao Corporation was used as dipotassium alkenyl succinate.

The ratio of the equivalent-circle particle diameter of the obtained butyl acrylate rubber latex (a-1) was calculated by the method described below. Graft polymerization was performed using 15 parts of the obtained butyl acrylate rubber latex (a-1) (in terms of solid content), 64 parts of styrene, and 21 parts of acrylonitrile, to obtain a graft copolymer. The graft copolymer powder was melt-kneaded to obtain pellets. From the obtained pellet, an ultrathin section was cut out at −85 ° C. using a cryomicrotome, stained with ruthenium tetroxide (RuO ₄ ), and photographed with a transmission electron microscope (JEM-1400: manufactured by JEOL Ltd.). I took a picture. The result of calculating the weight ratio of rubber particles of 250 nm or more by measuring the area of 1000 rubber particles using an image analyzer (Asahi Kasei IP-1000PC) and determining the equivalent circle diameter and the weight of the rubber particles. The acrylic rubber particles of 250 nm or more were 2% by weight. Moreover, the weight average particle diameter was 120 nm.

Production of butyl acrylate rubber latex (a-2) In a nitrogen-replaced glass reactor, 180 parts by weight of deionized water, 15 parts by weight of butyl acrylate, 0.1 parts by weight of allyl methacrylate, 0.12 parts by weight of dipotassium alkenyl succinate (Solid content conversion) 0.15 parts by weight of potassium persulfate was charged and reacted at 65 ° C. for 1 hour. Then, an emulsifier aqueous solution in which 0.88 parts by weight of dipotassium alkenyl succinate (in terms of solid content) was dissolved in 85 parts by weight of butyl acrylate and 0.53 parts by weight of allyl methacrylate and 20 parts by weight of deionized water for 3 hours. Over time. After dropping, the mixture was held for 3 hours to obtain butyl acrylate rubber latex (a-2).

  As a result of calculating the weight ratio and weight average particle diameter of the rubber particles of 250 nm or more of the obtained butyl acrylate rubber latex (a-2) by the above-mentioned method, the rubber particles of 250 nm or more are 70% by weight, and the weight average particles The diameter was 280 nm.

Production of acrylic composite rubber latex (a-3) In a nitrogen-replaced glass reactor, 270 parts by weight of deionized water, 2 parts by weight of styrene, 1 part by weight of butyl acrylate, 1 part by weight of dipotassium alkenyl succinate (in terms of solid content) And 0.2 part by weight of potassium persulfate was charged and polymerized at 65 ° C. for 1 hour. Thereafter, 4 parts each of 30 parts by weight of an aqueous emulsifier solution containing 78 parts by weight of styrene, 19 parts by weight of butyl acrylate, and 0.5 parts by weight of allyl methacrylate and 2 parts by weight of dipotassium alkenyl succinate (in terms of solid content). The polymerization was continuously added over time, and then the polymerization was continued for 2 hours. The polymerization was terminated to obtain an aromatic vinyl polymer. Next, in a glass reactor substituted with nitrogen, 150 parts by weight of deionized water, 10 parts by weight of the obtained aromatic vinyl polymer latex in terms of solid content, 5 parts by weight of butyl acrylate, 0.05 parts by weight of allyl methacrylate Parts, 0.05 parts by weight of dipotassium alkenyl succinate (in terms of solid content) and 0.3 parts by weight of potassium persulfate were added and reacted at 65 ° C. for 1 hour. Then, an emulsifier aqueous solution in which 0.45 parts by weight of dipotassium alkenyl succinate (in terms of solid content) was dissolved in 85 parts by weight of butyl acrylate and 0.45 parts by weight of allyl methacrylate and 20 parts of deionized water over 4 hours. Continuously added. Then, superposition | polymerization was continued at 65 degreeC for 3 hours, superposition | polymerization was complete | finished, and acrylic type composite rubber polymer latex (a-3) was obtained.

  As a result of calculating the weight ratio and weight average particle diameter of the rubber particles of 250 nm or more of the obtained acrylic composite rubber polymer latex (a-3) by the above method, the rubber particles of 250 nm or more are 6% by weight, The weight average particle diameter was 180 nm.

Production of Graft Copolymer (A-1) Into a glass reactor, 40 parts by weight (in terms of solid content) of butyl acrylate rubber latex (a-1) was charged to perform nitrogen substitution. After nitrogen substitution, when the temperature inside the tank reached 60 ° C., 0.2 part by weight of glucose, 0.1 part by weight of anhydrous sodium pyrophosphate and 0.005 part by weight of ferrous sulfate were added by 10 parts by weight of deionized water. An aqueous solution dissolved in was added. After reaching 65 ° C., a mixture of 12 parts by weight of acrylonitrile, 28 parts by weight of styrene, 0.1 part by weight of tertiary decyl mercaptan, 0.3 part by weight of cumene hydroperoxide and 20 parts by weight of deionized water was mixed with potassium oleate. An aqueous emulsifier solution in which 0 part by weight was dissolved was continuously added dropwise over 5 hours. After dripping, it was kept for 3 hours to obtain a graft copolymer latex. Thereafter, salting out, dehydration, and drying were performed to obtain a powder of the graft copolymer (A-1).

Production of Graft Copolymers (A-2) to (A-5) According to Table 1, butyl acrylate rubber latex (a-1) is changed from 40 parts by weight to 60 parts by weight, and butyl acrylate rubber latex (a-1) is acrylic. Produced in the same manner as the graft copolymer (A-1) except that the acid butyl rubber latex (a-2) or the acrylic composite rubber latex (a-3) was changed, and the graft copolymer latex (A-2) to (A-5) was obtained. Thereafter, salting out, dehydration and drying were performed to obtain powders of graft polymers (A-2) to (A-5).

Production of Copolymer (B-1) By a known emulsion polymerization method, a copolymer (B-1) comprising 75% by weight of styrene, 25% by weight of acrylonitrile and having a weight average molecular weight of 100,000 was obtained.

Production of copolymer (B-2) By a known emulsion polymerization method, a copolymer (B-2) comprising 75% by weight of styrene, 25% by weight of acrylonitrile and having a weight average molecular weight of 400,000 was obtained.

Production of copolymer (B-3) By a known emulsion polymerization method, a copolymer (B-3) comprising 75% by weight of styrene, 25% by weight of acrylonitrile and having a weight average molecular weight of 4.5 million was obtained.

Additive (C)
C-1 (ultraviolet absorber): Trade name “Sumisorb 200” (manufactured by Sumitomo Chemical Co., Ltd.)
C-2 (light stabilizer): trade name “ADK STAB LA77Y” (manufactured by ADEKA Corporation)

<Examples 1-7 and Comparative Examples 1-7>
After mixing the graft copolymer (A), copolymer (B), and additive (C) shown in Table 2, the temperature was set to 220 ° C. using a 40 mm single screw extruder (manufactured by Tanabe Plastics Machinery Co., Ltd.). The mixture was melt kneaded to obtain pellets. Various molded products were molded from the obtained pellets and evaluated for physical properties. The evaluation results are shown in Table 2. In addition, each evaluation method is shown below.

Die Swell Ratio The die swell ratio of the pellets obtained in each Example and Comparative Example was measured by the following method.
Using a capillary rheometer made by MALNVERN, measure the strand diameter extruded with a caliper at 200 ° C., shear rate 100 (1 / sec) and orifice diameter 2.0 mm, and divide the strand diameter by the orifice diameter. It was.

Using the pellets obtained in each of the examples of whitening and the comparative example, a 40 mm sheet extruder (manufactured by Tanabe Plastics Machine Co., Ltd.) was used to prepare a sheet having a thickness of 1 mm under a molding temperature of 200 ° C. The presence or absence of whitening when the sheet was bent by 90 ° was visually determined.
◎: No whitening ○: Slightly whitening ×: Remarkably whitening

Weather resistance Molded product (90 mm) molded with an injection molding machine (Yamagi Seiki Seisakusho SAV-30-30 cylinder temperature: 220 ° C. mold temperature: 60 ° C.) using the pellets obtained in each Example and Comparative Example Using a Sunshine Super Long Life Weather Meter (WEL-SUN-HCH-B) manufactured by Suga Test Instruments Co., Ltd., and accelerating for 1500 hours under conditions of 63 ° C. and rain An exposure test was conducted. Thereafter, the color difference (ΔE) before and after exposure was measured using a colorimeter.
◎: Slight hue change ΔE = less than 3 ○: Slight hue change ΔE = 3 or more, less than 5 ×: Unacceptable hue change ΔE = 5 or more

Molding workability It was visually determined whether or not both end portions of the 1 mm thick sheet were formed in a die shape.
A: Accurately formed according to the shape of the die ○: Slightly rounded but formed according to the shape of the die ×: Rounded and not formed according to the shape of the die

  As shown in Table 2, when the thermoplastic resin composition for extrusion molding of the present invention was used, not only the weather resistance but also the low whitening property and molding processability were excellent. When the ratio of the number of particles was sufficiently small, not only the whitening property but also the weather resistance was particularly excellent, and when the die swell ratio sufficiently exceeded 1.10, the molding processability was particularly excellent.

  As shown in Comparative Examples 1, 2, 4 to 7 in Table 2, when the number of particles of the acrylic rubber-like polymer exceeded 10%, the result was inferior in the whitening property. In Comparative Examples 2 and 3 having a die swell ratio of less than 1.10, the molding processability was inferior.

  Since the thermoplastic resin composition for extrusion molding of the present invention is excellent not only in weather resistance but also in molding processability and whitening property, it is highly useful for indoor and outdoor products used for housing building materials.

Claims (2)

  A thermoplastic resin composition containing 20 to 90 parts by weight of the graft copolymer (A) and 10 to 80 parts by weight of the copolymer (B) (the total of the graft copolymer (A) and the copolymer (B) is 100 In the presence of 10 to 80 parts by weight of an acrylic rubbery polymer, the graft copolymer (A) is a vinyl cyanide monomer, an aromatic vinyl monomer and a copolymer thereof. It is a graft copolymer (A) obtained by graft polymerization of 20 to 90 parts by weight of at least one monomer selected from other polymerizable vinyl monomers, and the copolymer (B) is aromatic. Is a copolymer (B) obtained by polymerizing an aromatic vinyl monomer, a vinyl cyanide monomer, and other vinyl monomers that can be copolymerized if necessary, and is thermoplastic. For the acrylic rubber-like polymer present in the resin composition, the equivalent circle particle diameter Particles that are 250 nm or more are 10% by weight or less based on the acrylic rubber-like polymer, and the die swell ratio of the thermoplastic resin composition measured at 200 ° C. and a shear rate of 100 (1 / sec) is 1.10 or more. A thermoplastic resin composition for extrusion molding, characterized in that   An extruded product obtained by extrusion molding of the thermoplastic resin composition for extrusion molding according to claim 1.