Resin composition, method of producing the same, and molded product using the same

Abstract

Objects of the present invention are to provide a resin composition having good impact resistance, surface smoothness, color developability, and appearance of the molded product, and a method of producing it. Main objects are to provide a resin composition, and a production method for obtaining the resin composition, the resin composition containing a graft copolymer (A) obtained by graft copolymerization of a monomer mixture (a) containing at least an aromatic vinyl monomer (a1) and a vinyl cyanide monomer (a2) in the presence of an acrylic rubber-like polymer (R) obtained by copolymerization of an acrylic acid alkyl ester monomer (r1) and a polyfunctional monomer (r2); and a vinyl copolymer (B) obtained by copolymerization of a monomer mixture (b) containing at least an aromatic vinyl monomer (b1) and a vinyl cyanide monomer (b2), in which the ratio of the total mass of anionic surfactants contained in the resin composition to the total mass of the resin composition is 5,000 ppm (mass / mass) or less; and the ratio of the total of a sulfosuccinic acid compound (E) represented by the following chemical formula [1] and disproportionated rosin (F) contained in the resin composition to the total mass of the resin composition is 2,000 ppm (mass / mass) or less; and the mass ratio of the sulfosuccinic acid compound (E) to the disproportionated rosin (F) is 10:90 to 30:70 (sulfosuccinic acid compound (E): disproportionated rosin (F)): [chem 1] in which R is a C8-22 alkyl or alkenyl group; AO is a C2 or C3 oxyalkylene group; n is an integer from 0 to 20; M and N each independently represent hydrogen, an alkali metal, or an alkaline earth metal; p is 1 when M is hydrogen or an alkali metal, or is 1 / 2 when M is an alkaline earth metal; and q is 1 when N is hydrogen or an alkali metal, 81 or is 1 / 2 when N is an alkaline earth metal.

Description

DESCRIPTIONTitle of Invention: RESIN COMPOSITION, METHOD OF PRODUCING THE SAME, AND MOLDED PRODUCT USING THE SAMETechnical Field

[0001] The present invention relates to a resin composition useful for resin molded products used in home appliances, telecommunication equipment, general merchandise, and automotive materials, as well as to a method of producing the resin composition.Background Art

[0002] ABS resins, obtained by polymerizing diene rubbery polymers, aromatic vinyl monomers, vinyl cyanide monomers, methacrylate ester monomers, or the like, are excellent in impact resistance, moldability, and appearance, and thus are widely used in various applications, such as OA equipment, home appliances, and sundries. However, since ABS resins have many chemically unstable double bonds in the main chain of the polymer, they are easily deteriorated by UV rays or the like, i.e., have poor weather resistance, and thus has had difficulty in using them outdoors. Accordingly, methods using saturated rubber polymers that do not have any double bond in their main chains have been suggested. As representatives thereof, many ASA resins using acrylic rubbers are known, which are excellent in weather resistance and widely used mainly for vehicle applications.

[0003] Patent Document 1 suggests a resin composition which is excellent in impactresistance, and in which an organic silicone oil was added to a composition using a specific acrylic rubber and / or silicone rubber as a technique to improve the color developability, weather resistance, stiffness, heat resistance, and processability.

[0004] On the other hand, styrene -based thermoplastic resin compositions containing heat-resistant vinyl copolymers exhibit good heat resistance as molded products, and thus are widely used in applications and the field of automotive materials, especially in lamp housing applications. Lamp housings are usually subjected to secondary processes such as painting, metal deposition, and plating to increase the brightness of vehicle lamps. To achieve beautiful appearance after painting, metal deposition, plating, or other secondary process, the surface of the molded product before the secondary process is required to have excellent smoothness. To smooth the surface of the molded product to be subjected to a secondary process, undercoating is usually performed. Molded products with smoothness would not need formation of an undercoat layer and thus allow a metal layer to be directly formed, leading to reduction of costs of the products. As methods for forming a metal layer with the formation of an undercoat layer omitted, so-called “direct deposition methods” are commonly used in recent years. Thus, resin compositions used for formation of lamp housing or the like are required to provide molded products with excellent smoothness.

[0005] Patent Document 2 suggests an acrylic rubber-reinforced copolymer resin obtained by polymerizing vinyl monomers comprising an aromatic vinyl compound and vinyl cyanide compound in the presence of an acrylic rubber-like polymer obtained by emulsion polymerization using emulsifiers comprising an alkyl sulfonic acid salt and a rosin acid salt, as a technique to improve the vibration welding, hotplate welding properties, and the lamp brightness after deposition.

[0006] However, all of these techniques have resulted in resin compositions with insufficient balance of impact resistance, surface smoothness, color developability, and appearance of the molded product (due to effects of volatile components on appearance), and thus their application to a wide range of applications may be restricted.Citation ListPatent Literature

[0007] Patent Literature 1 JP 2001-031830 APatent Literature 2 JP 2006- 131677 ASummary of InventionTechnical Problem

[0008] The present invention aims to solve the problems in the conventional art as described above, i.e., to provide a resin composition having good impact resistance, surface smoothness, color developability, and appearance of the molded product, and a method of producing the resin composition.Solution to Problem

[0009] In order to solve the above problems, the present inventors have intensively studied to find that a resin composition comprising a vinyl copolymer obtained by copolymerizing a vinyl monomer mixture and a graft copolymer containing an acrylic rubber-like polymer, and preferably comprising a heat-resistant vinyl copolymer, wherein the resin composition is obtained by a production method using a specific emulsifier in a specific amount range, can exhibit excellent impact resistance, as wellas good surface smoothness, color develop ability, and appearance of the molded product, thereby completing the present invention.

[0010] That is, an aspect of the present invention is as follows:(1) A method of producing a resin composition, comprising the following steps: step 1 of performing the following steps 1-A to 1-C in this order to obtain a graft copolymer (A): step 1-A of copolymerizing 100 parts by mass of a monomer mixture (r) composed of 97-99.5 parts by mass of an acrylic acid alkyl ester monomer (rl) and 0.5-3 parts by mass of a polyfunctional monomer (r2) in the presence of 0.15-0.45 parts by mass of a sulfosuccinic acid compound (E) represented by the following chemical formula [1] and 1.5-3 parts by mass of disproportionated rosin (F), the sulfosuccinic acid compound (E) and the disproportionated rosin (F) serving as emulsifiers, to obtain a rubber-like polymer (R) latex;

[0011] [chem 1]

[0012] whereinR is a Cs-22 alkyl or alkenyl group;AO is a C2 or C3 oxy alkylene group; n is an integer from 0 to 20;M and N each independently represent hydrogen, an alkali metal, or an alkaline earth metal; p is 1 when M is hydrogen or an alkali metal, or is 1 / 2 when M is analkaline earth metal; and q is 1 when N is hydrogen or an alkali metal, or is 1 / 2 when N is an alkaline earth metal; step 1-B of graft copolymerizing a monomer mixture (a) comprising at least an aromatic vinyl monomer (al) and a vinyl cyanide monomer (a2) with the rubber-like polymer (R) in the presence of the rubber-like polymer (R) latex to obtain a graft copolymer (A) latex; and step 1-C of contacting the graft copolymer (A) latex with an acid, which is then neutralized with an alkali, washed with water, and dried to obtain a graft copolymer (A); step 2 of copolymerizing a monomer mixture (b) comprising at least an aromatic vinyl monomer (bl) and a vinyl cyanide monomer (b2) to obtain a vinyl copolymer (B); and step 3 of mixing the graft copolymer (A) obtained in the step 1 and the vinyl copolymer (B) obtained in the step 2, wherein the ratio of the total mass of anionic surfactants contained in the resin composition to the total mass of the resin composition is 5,000 ppm (mass / mass) or less; and wherein the ratio of the total of the sulfosuccinic acid compound (E) represented by the chemical formula [1] and disproportionated rosin (F) contained in the resin composition to the total mass of the resin composition is 2,000 ppm (mass / mass) or less;(2) The method of producing a resin composition of (1), further comprising: performing the following step 4 to obtain a heat-resistant vinyl copolymer (C); and mixing the resulting heat-resistant vinyl copolymer (C) with the graft copolymer (A) and the vinyl copolymer (B) in the step 3 to obtain a resin composition:step 4 of copolymerizing a monomer mixture (c) comprising at least an aromatic vinyl monomer (cl) and a maleimide monomer (c2) to obtain a heat-resistant vinyl copolymer (C);(3) The method of producing a resin composition of (1) or (2), wherein the sulfosuccinic acid compound (E) and disproportionated rosin (F) are used in the step 1-A in a mass ratio of 9:91 to 30:70 (sulfosuccinic acid compound (E): disproportionated rosin (F));(4) A resin composition, comprising: a graft copolymer (A) obtained by graft copolymerization of a monomer mixture (a) comprising at least an aromatic vinyl monomer (al) and a vinyl cyanide monomer (a2) in the presence of an acrylic rubber-like polymer (R) obtained by copolymerization of an acrylic acid alkyl ester monomer (rl) and a polyfunctional monomer (r2); and a vinyl copolymer (B) obtained by copolymerization of a monomer mixture (b) comprising at least an aromatic vinyl monomer (bl) and a vinyl cyanide monomer (b2), wherein the ratio of the total mass of anionic surfactants contained in the resin composition to the total mass of the resin composition is 5,000 ppm (mass / mass) or less; and wherein the ratio of the total of a sulfosuccinic acid compound (E) represented by the following chemical formula [1] and disproportionated rosin (F) contained in the resin composition to the total mass of the resin composition is 2,000 ppm (mass / mass) or less; and wherein the mass ratio of the sulfosuccinic acid compound (E) to the disproportionated rosin (F) is 10:90 to 30:70 (sulfosuccinic acid compound (E): disproportionated rosin (F)):

[0013] [chem 2]

[0014] whereinR is a Cs-22 alkyl or alkenyl group;AO is a C2 or C3 oxy alkylene group; n is an integer from 0 to 20;M and N each independently represent hydrogen, an alkali metal, or an alkaline earth metal; p is 1 when M is hydrogen or an alkali metal, or is 1 / 2 when M is an alkaline earth metal; and q is 1 when N is hydrogen or an alkali metal, or is 1 / 2 when N is an alkaline earth metal;(5) The resin composition of (4), further comprising a heat-resistant vinyl copolymer (C) obtained by copolymerizing a monomer mixture (c) comprising at least an aromatic vinyl monomer (cl) and a maleimide monomer (c2);(6) A molded product obtained by molding a resin composition obtained by the method of producing a resin composition of any one of (1) to (3), or by molding the resin composition of (4) or (5).Advantageous Effects of Invention

[0015] According to the present invention, a resin composition having good impact resistance, surface smoothness, color developability, and appearance of the molded product, and a method of producing the resin composition.Brief Description of Drawings

[0016] Fig. 1 is a transmission electron microscopic (TEM) image of a resin composition produced by the method described in Comparative Example 2.Description of Embodiments

[0017] A resin composition of the present invention contains at least the following components:Component 1 : a graft copolymer (A) obtained by graft copolymerization of a monomer mixture (a) comprising at least an aromatic vinyl monomer (al) and a vinyl cyanide monomer (a2) in the presence of an acrylic rubber-like polymer (R) obtained by copolymerization of an acrylic acid alkyl ester monomer (rl) and a polyfunctional monomer (r2);Component 2: a vinyl copolymer (B) obtained by copolymerization of a monomer mixture (b) comprising at least an aromatic vinyl monomer (bl) and a vinyl cyanide monomer (b2);Component 3: a sulfosuccinic acid compound (E) represented by the following chemical formula [1]:

[0018] [chem 3]

[0019] whereinR is a Cs-22 alkyl or alkenyl group;AO is a C2 or C3 oxy alkylene group;n is an integer from 0 to 20;M and N each independently represent hydrogen, an alkali metal, or an alkaline earth metal; p is 1 when M is hydrogen or an alkali metal, or is 1 / 2 when M is an alkaline earth metal; and q is 1 when N is hydrogen or an alkali metal, or is 1 / 2 when N is an alkaline earth metal; andComponent 4: disproportionated rosin (F).

[0020] As described later, the resin composition of the present invention can comprise other components, as necessary. Preferably, the resin composition of the present invention can also comprise a heat-resistant vinyl copolymer (C) obtained by copolymerizing a monomer mixture (c) comprising at least an aromatic vinyl monomer (cl) and a maleimide monomer (c2).

[0021] Actions of the components in the resin composition of the present invention are not necessarily clear, but the present inventors understand them as described below. That is, the graft copolymer (A) can improve the moldability of the resin composition, improve the impact resistance, surface smoothness, and color developability of the molded product, and enhance the appearance of the molded product. The vinyl copolymer (B) can improve the flowability of the resin composition, improve the color developability of the molded product, and enhance the appearance of the molded product. The sulfosuccinic acid compound (E) can the surface smoothness and color developability of the molded product, and enhance the appearance of the molded product. The disproportionated rosin (F) can improve the impact resistance of the molded product. The heat-resistant vinyl copolymer (C) can impart heat resistance to the molded product.

[0022] Methods of obtaining the components will be described below in more detail with reference to specific examples.

[0023] A graft copolymer (A) used in the present invention (Component 1) can be produced by performing the steps 1-A to 1-C described below in this order.

[0024] (Step 1-A) A step of copolymerizing 100 parts by mass of a monomer mixture (r) composed of 97-99.5 parts by mass of an acrylic acid alkyl ester monomer (rl) and 0.5-3 parts by mass of a polyfunctional monomer (r2) in the presence of 0.15-0.45 parts by mass of a sulfosuccinic acid compound (E) represented by the above chemical formula [1] and 1.5-3 parts by mass of disproportionated rosin (F), the sulfosuccinic acid compound (E) and the disproportionated rosin (F) serving as emulsifiers, to obtain a rubber-like polymer (R) latex.An acrylic acid alkyl ester monomer (rl) for obtaining a rubber- like polymer (R) may preferably have a Ci-io alkyl group, and examples thereof include methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, and octyl acrylate. Two or more of them may be used. Especially, n-butyl acrylate is preferably used.

[0025] A polyfunctional monomer (r2) for obtaining a rubber-like polymer (R) may be any capable of polymerization with the acrylic acid alkyl ester monomer (rl) and having two or more functional groups, and examples of the functional groups include groups having a carbon-carbon double bond, such as allyl and (meth)acryloyl groups. Examples of the polyfunctional monomer (r2) include allyl compounds such as allyl acrylate, allyl methacrylate, diallyl maleate, triallyl cyanurate, and triallyl isocyanurate; and di(meth) acrylic ester compounds such as divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and propylene glycoldimethacrylate. Two or more of them may be used. Especially, allyl methacrylate is preferable.

[0026] A rubber-like polymer (R) used in the present invention is obtained by copolymerization of 100 parts by mass of a monomer mixture (r) composed of 97-99.5 parts by mass of an acrylic ester monomer (rl) and 0.5-3 parts by mass of a polyfunctional monomer (r2). In cases where the acrylic ester monomer (rl) amount is less than 97 parts by mass, or the polyfunctional monomer (r2) amount is more than 3 parts by mass relative to 100 parts by mass of a monomer mixture (r), the rubberlike polymer (R) has increased degree of crosslinking, resulting in hardening of the rubber-like polymer (R), concentration of stress on portions having smaller molecular weight between crosslinking points when stress is applied, and breakage of the molecular chain, which thus reduces the impact resistance of the molded product. The monomer mixture (r) preferably contains 98 parts by mass or more of the acrylic ester monomer (rl) and 2 parts by mass or less of the polyfunctional monomer (r2), and more preferably contains more than 98.5 parts by mass of the acrylic ester monomer (rl) and less than 1.5 parts by mass of the polyfunctional monomer (r2). The monomer mixture (r) is a mixture of an acrylic ester monomer (rl) and a polyfunctional monomer (r2), but this does not preclude other components from being used together during polymerization as long as they do not impair the object of the present invention.

[0027] On the other hand, in cases where the acrylic ester monomer (rl) amount is more than 99.5 parts by mass, or the polyfunctional monomer (r2) amount is less than 0.5 parts by mass relative to 100 parts by mass of the monomer mixture (r), the rubberlike polymer has increased degree of swelling. As a result, the graft copolymer (A) particles are more likely to take aggregated structures, and uncross-linked molecularchains are eluted in the resin composition, so that the surface smoothness and color developability of the molded product are reduced. The monomer mixture (r) preferably contains 99.4 parts by mass or less of the acrylic ester monomer (rl), and more preferably 99.2 parts by mass or less. The monomer mixture (r) preferably contains 0.6 parts by mass or more of the polyfunctional monomer (r2), and more preferably 0.8 parts by mass or more.

[0028] In the present invention, the volume mean particle diameter of the rubber-like polymer (R) is not particularly limited, and is preferably in a range from 0.05 to 1 pm from the viewpoint of the impact resistance, surface smoothness, and color developability of the molded product comprising a graft copolymer (A) obtained using a rubber- like polymer (R), and a vinyl copolymer (B). The volume mean particle diameter is more preferably in a range from 0.05 to 0.5 pm, still more preferably in a range from 0.05 to 0.2 pm, and most preferably in a range from 0.05 to 0.15 pm.

[0029] In the present invention, the standard deviation of the volume mean particle diameter of the rubber-like polymer (R) is not particularly limited, and preferably, from the viewpoint of the surface smoothness and color developability of the molded product comprising a graft copolymer (A) obtained using a rubber-like polymer (R), and a vinyl copolymer (B), is 0.05 pm or less, more preferably 0.03 pm or less, and still more preferably 0.01 pm or less.

[0030] The volume mean particle diameter of the rubber-like polymer (R) can be adjusted into a desired range by changing, for example, the amounts of water, emulsifiers, polymerization initiators used in the polymerization. The volume mean particle diameter may be adjusted into a desired range by means of enlargement caused by addition of an aqueous acid solution, e.g. acetic acid, phosphoric acid and sulfuricacid or addition of acid group-containing latex, within the preferred range of the volume mean particle diameter of the rubber-like polymer (R) and its standard deviation described above. As used herein, the acid group-containing latex is a latex formed with an unsaturated acid monomer and an unsaturated alkyl carbonate ester monomer.

[0031] The volume mean particle diameter of the rubber-like polymer (R) and its standard deviation can be determined with the rubber-like polymer (R) latex dispersed in water, using a laser scattering diffraction particle size distribution analyzer.

[0032] The rubber-like polymer (R) preferably contains acetone-soluble matter having a weight average molecular weight, in terms of styrene, from 30,000 to 60,000. The acetone-soluble matter in the rubber-like polymer (R) mainly comprises uncrosslinked linear polymer of acrylic acid alkyl ester monomer, which is considered to indirectly represent the length of the molecular chains constituting the rubber-like polymer (R). In cases where the weight average molecular weight, in terms of styrene, of acetone-soluble matter in the rubber-like polymer (R) is 30,000 or more, the molded product can have further improved impact resistance while keeping the surface smoothness. In addition, because this linear polymer may cause impairment of the surface smoothness of the molded product as described above, and because this is more pronounced in cases where the linear polymer is long-chain, the molded product can have further improved surface smoothness while keeping the impact resistance in cases where the weight average molecular weight in terms of styrene of the acetone- soluble matter in the rubber-like polymer (R) is 60,000 or less.

[0033] Here, the weight average molecular weight in terms of styrene of the acetonesoluble matter in the rubber-like polymer (R) can be determined by the followingmethod.

[0034] That is, about 80 ml of acetone is added to about 1 g of a rubber-like polymer (R) for impregnation for about 12 hours. Next, the dispersion of the rubber-like polymer (R) in acetone is filtered, and the filtrate is concentrated with a rotary evaporator to obtain acetone-soluble matter in the rubber-like polymer (R). About 0.02 g of the obtained acetone- soluble matter is dissolved in about 8 g of tetrahydrofuran (THF) to prepare a solution of the acetone-soluble matter in THF. Conversion using polystyrene as standard from the GPC chromatogram measured using this solution can give the weight average molecular weight. The GPC measurement can be performed under the following conditions:Analyzer: Waters 2695Column temperature: 40°CDetector: RI2414 (differential refractometer)Carrier eluent flow rate: 0.3 ml / min (solvent: tetrahydrofuran)Column: TSKgel SuperHZM-M (6.0 mm I.D. x 15 cm) and TSKgel SuperHZM-N (6.0 mm I.D. x 15 cm) in tandem (both produced by Tosoh Corporation).

[0035] In cases where a rubber-like polymer (R) is obtained from a rubber-like polymer (R) latex, 10 ml of a rubber-like polymer (R) latex is added to 150 ml of methanol to obtain a dispersion in methanol. Then, 20 ml of an aqueous calcium chloride solution, adjusted to 10% by mass, is added to the methanol dispersion in methanol, dehydrated, washed, and dried in vacuum, so that a rubber-like polymer (R) can be obtained.

[0036] The polymerization method used for the rubber-like polymer (R) is the emulsion polymerization method from the viewpoint of adjusting the degree ofcrosslinking and particle size distribution of the rubber-like polymer (R) into desired ranges via the balance among oily monomer droplets, the aqueous phase, and polymer particles.

[0037] The initiator used for polymerization is not particularly restricted, and for example, peroxide, an azo compound, or persulfate is used.

[0038] Specific examples of the peroxide include benzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butyl isopropyl carbonate, di-t-butyl peroxide, t-butyl peroctoate, l,l-bis(t-butylperoxy)3,3,5- trimethylcyclohexane, l,l-bis(t-butylperoxy)cyclohexane, and t-butyl peroxy-2- ethylhexanoate.

[0039] Specific examples of the azo compound include azobisisobutyronitrile, azobis(2,4-dimethylvaleronitrile), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2-cyano-2-propylazoformamide, 1, l’-azobiscyclohexane-l -carbonitrile, azobis(4- methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2’-azobisisobutyrate, l-t-butylazo-2- cyanobutane, and 2-t-butylazo-2-cyano-4-methoxy-4-methylpentane.

[0040] Specific examples of the persulfate include potassium persulfate, sodium persulfate, and ammonium persulfate.

[0041] Two or more of these initiators may be used. In the emulsion polymerization method, for example, potassium persulfate or cumene hydroperoxide is preferably used. A redox initiator may also be used.

[0042] In the present invention, emulsifiers used in the emulsion polymerization method for rubber- like polymer (R) are a sulfosuccinic acid compound (E) represented by the following chemical formula [1] and disproportionated rosin (F).

[0043] The sulfosuccinic acid compound (E) used in the present invention is a compound represented by the following chemical formula [1]:

[0044] [chem 4]

[0045] whereinR is a Cs-22 alkyl or alkenyl group;AO is a C2 or C3 oxy alkylene group; n is an integer from 0 to 20;M and N each independently represent hydrogen, an alkali metal, or an alkaline earth metal; p is 1 when M is hydrogen or an alkali metal, or is 1 / 2 when M is an alkaline earth metal; and q is 1 when N is hydrogen or an alkali metal, or is 1 / 2 when N is an alkaline earth metal.

[0046] In the chemical formula [1], R represents a Cs-22 alkyl or alkenyl group. The alkyl group may be linear or branched, and may have a ring structure, such as a cycloalkyl structure. The carbon number of the alkyl group is preferably 12 or more, and is more preferably 16 or less. Specifically, R is preferably a n-dodecyl group, ann-tridecyl group, an n-tetradecyl group, or an isotridecyl group.

[0047] AO represents a C2 or C3 oxy alkylene group. The oxy alkylene group may be linear or branched. Specifically, the oxyalkylene group is an oxyethylene group or an oxypropylene group.

[0048] M and N each independently represent hydrogen, an alkali metal, or an alkaline earth metal. Examples of the alkali metal include sodium, potassium, lithium, rubidium, or cesium. Examples of the alkaline earth metal include calcium, barium, magnesium, and strontium. Especially, any of hydrogen, sodium, potassium, calcium, and magnesium are preferable as M and N, and sodium and potassium are more preferable.

[0049] n is an integer from 0 to 20, and is preferably an integer of 3 or more and is preferably an integer of 10 or less.

[0050] As the sulfosuccinic acid compound (E) represented by the chemical formula [1], mono-n-dodecyl sulfosuccinic acid, mono-n-dodecyl monooxy ethylene sulfosuccinic acid, mono-n-dodecyl dioxyethylene sulfosuccinic acid, or an alkali metal salt thereof or an alkaline earth metal salt thereof is preferably used. More preferably, the sulfosuccinic acid compound (E) is an alkali metal salt of mono-n- dodecyl sulfosuccinic acid, mono-n-dodecyl monooxyethylene sulfosuccinic acid, or mono-n-dodecyl dioxyethylene sulfosuccinic acid.

[0051] These sulfosuccinic acid compounds (E) may be used alone or in combination of two or more thereof.

[0052] A product containing a sulfosuccinic acid compound (E) represented by the chemical formula [1] may be, for example, KOHACOOL L-300 produced by TOHO Chemical Industry Co., Ltd.

[0053] In the step 1-A, the amount of the sulfosuccinic acid compound (E) represented by the chemical formula [1] contained relative to 100 parts by mass of a monomer mixture (r) composed of 97-99.5 parts by mass of an acrylic acid alkyl ester monomer (rl) and 0.5-3 parts by mass of a polyfunctional monomer (r2) is from 0.15 parts by mass to 0.45 parts by mass. In cases where the amount of the sulfosuccinic acid compound (E) contained is less than 0.15 parts by mass, rubber with large particle diameters of more than 1 pm as shown in Fig. 1 is produced during emulsion polymerization, causing reduction of the surface smoothness and color developability of the molded product. On the other hand, in cases where the amount of the sulfosuccinic acid compound (E) contained is more than 0.45 parts by mass, the impact resistance of the molded product and appearance of the molded product are reduced.

[0054] Disproportionated rosin (F) is disproportionated rosin acid obtained from rosin, which refers to a monobasic acid having a cyclic diterpene structure, by mixing it with a catalyst, followed by heat melting for proton transfer, or an alkali metal salt thereof or an alkaline earth metal salt thereof. For example, natural rosins such as gum rosin, tall oil rosin, and wood rosin contain abietic acid as a main component, as well as, for example, neoabietic acid, palustric acid, dehydroabietic acid, pimaric acid, and isopimaric acid. Disproportionation of such unrefined rosin can give disproportionated rosin acid. In usual, this disproportionated rosin acid is preferably saponified with, for example, potassium hydroxide and used as an alkali metal salt.

[0055] Examples of products containing disproportionated rosin (F) includeDIPROSIN A- 100 and DIPROSIN K-25 produced by TOHO Chemical Industry Co.,Ltd.

[0056] In the step 1-A, the amount of the disproportionated rosin (F) contained relative to 100 parts by mass of a monomer mixture (r) composed of 97-99.5 parts by mass of an acrylic acid alkyl ester monomer (rl) and 0.5-3 parts by mass of a polyfunctional monomer (r2) is from 1.5-3 parts by mass. In cases where the amount of disproportionated rosin (F) contained is less than 1.5 parts by mass, the impact resistance of the molded product is reduced, and the appearance of the molded product is reduced. On the other hand, in cases where the amount of disproportionated rosin (F) contained is more than 3 parts by mass, the surface smoothness and color developability of the molded product are reduced.

[0057] In the step 1-A, the ratio of the sulfosuccinic acid compound (E) to the disproportionated rosin (F) (sulfosuccinic acid compound (E): disproportionated rosin (F)) is preferably from 9:91 to 30:70. More preferably, the ratio is from 9:91 to 20:80. In cases where the sulfosuccinic acid compound (E) is contained at a ratio below 9:91, rubber with large particle diameters of more than 1 pm as shown in Fig. 1 may be produced during emulsion polymerization, which can cause reduction of the surface smoothness and color developability of the molded product, and thus such cases are undesirable. On the other hand, in cases where the sulfosuccinic acid compound (E) is contained at a ratio over 30:70, the impact resistance of the molded product can be reduced, and the appearance of the molded product can also be reduced, and thus such cases are undesirable.

[0058] (Step 1-B) A step of graft copolymerizing a monomer mixture (a) comprising at leastan aromatic vinyl monomer (al) and a vinyl cyanide monomer (a2) with the rubberlike polymer (R) in the presence of the rubber-like polymer (R) latex to obtain a graft copolymer (A) latex.In the present invention, graft copolymer (A) refers to the generic name of polymers produced during the step for obtaining a graft copolymer (A), including polymers produced by graft polymerization with a rubber- like polymer (R), as well as polymer components produced without graft polymerization with a rubber-like polymer (R).

[0059] The amount of the rubber-like polymer (R) contained in the graft copolymer (A) is preferably from 20% by mass to 80% by mass relative to the total amount of graft copolymer (A). In cases where the amount of the rubber-like polymer (R) contained relative to the total amount of the graft copolymer (A) is 20% by mass or more, the impact resistance of the molded product can be further improved. The amount of the rubber-like polymer (R) contained relative to the total amount of the graft copolymer (A) is more preferably 35% by mass or more. On the other hand, in cases where the amount of the rubber-like polymer (R) contained relative to the total amount of the graft copolymer (A) is 80% by mass or less, the flowability of the final resin composition, and the impact resistance, surface smoothness, color developability, and appearance of the molded product can be further improved. The amount of the rubber-like polymer (R) contained relative to the total amount of the graft copolymer (A) is more preferably 60% by mass or less.

[0060] Examples of the aromatic vinyl monomer (al) in the monomer mixture (a) include styrene, alpha-methylstyrene, p-methylstyrene, m-methylstyrene, o- methylstyrene, vinyltoluene, and t-butylstyrene. Two or more of them may be used as aromatic vinyl monomers (al). Among those aromatic vinyl monomers (al),styrene is preferable from the viewpoint of further improving the flowability of the final resin composition and the stiffness of the molded product.

[0061] The amount of the aromatic vinyl monomer (al) contained in the monomer mixture (a) is preferably 60% by mass or more, more preferably 65% by mass or more, and still more preferably 70% by mass or more relative to 100% by mass in total of the monomer mixture (a) from the viewpoint of further improving the flowability of the final resin composition and the stiffness of the molded product. On the other hand, the amount of the aromatic vinyl monomer (al) contained in the monomer mixture (a) is preferably 85% by mass or less, more preferably 80% by mass or less, and still more preferably 75% by mass or less from the viewpoint of improving the impact resistance of the molded product.

[0062] Examples of the vinyl cyanide monomer (a2) in the monomer mixture (a) include acrylonitrile, methacrylonitrile, and ethacrylonitrile. Two or more of them may be contained as vinyl cyanide monomers (a2). Among those vinyl cyanide monomers (a2), acrylonitrile is preferable from the viewpoint of further improving the impact resistance of the molded product.

[0063] The amount of the vinyl cyanide monomer (a2) contained in the monomer mixture (a) is preferably 20% by mass or more, more preferably 25% by mass or more, and still more preferably 30% by mass or more relative to 100% by mass in total of the monomer mixture (a) from the viewpoint of improving the impact resistance of the molded product. On the other hand, the amount of the vinyl cyanide monomer (a2) contained in the monomer mixture (a) is preferably 40% by mass or less, and more preferably 35% by mass or less from the viewpoint of improving the flowability of the final resin composition and the color tone of the molded product.

[0064] The monomer mixture (a) may further contain other monomers that are capable of being copolymerized with the aromatic vinyl monomer (al) and the vinyl cyanide monomer (a2).

[0065] The other monomers that are capable of being copolymerized with the aromatic vinyl monomer (al) and the vinyl cyanide monomer (a2) described above are not particularly restricted, as long as they are vinyl monomers other than the aromatic vinyl monomer (al) and vinyl cyanide monomer (a2) described above, which do not impair the effect of the present invention. Specific examples of the other monomers include (meth)acrylic ester monomers (a3), unsaturated fatty acids, acrylamide monomers, and maleimide monomers, two or more of which may be used.

[0066] A (meth)acrylic ester monomer (a3) that may be contained in the monomer mixture (a) may be, for example, an ester of a Ci-6 alcohol and acrylic acid or methacrylic acid. The ester of a Ci-6 alcohol and acrylic acid or methacrylic acid may further have a substituent such as a hydroxy group or a halogen group. Examples of the ester of a Ci-6 alcohol and acrylic acid or methacrylic acid include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth) acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, chloromethyl (meth) acrylate, 3-hydroxypropyl (meth)acrylate, 2, 3, 4,5,6- pentahydroxyhexyl (meth)acrylate, and 2,3,4,5-tetrahydroxypentyl (meth) acrylate. Two or more of them may be contained as (meth)acrylic ester monomers (a3). Among those (meth)acrylic ester monomers (a3), methyl (meth) acrylate is preferable from the viewpoint of further improving the color developability of the molded product. As used herein, the term “(meth)acrylic acid” means both acrylic acid and methacrylic acid. For example, methyl (meth)acrylate means both methyl methacrylate andmethyl acrylate.

[0067] In cases where a (meth)acrylic ester monomer (a3) is used, the amount of the (meth)acrylic ester monomer (a3) contained in the monomer mixture (a) is preferably 30% by mass or more, more preferably 50% by mass or more, and still more preferably 70% by mass or more relative to 100% by mass in total of the monomer mixture (a) from the viewpoint of further improving the color developability of the molded product. On the other hand, the amount of the (meth)acrylic ester monomer (a3) contained in the monomer mixture (a) is preferably 90% by mass or less, more preferably 85% by mass or less, and still more preferably 80% by mass or less from the viewpoint of further improving the impact resistance of the molded product.

[0068] Examples of the unsaturated fatty acid include itaconic acid, maleic acid, fumaric acid, butenoic acid, acrylic acid, and methacrylic acid. Examples of the acrylamide monomer include acrylamide, methacrylamide, and N-methylacrylamide. Examples of the maleimide monomer include N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide, N-octylmaleimide, N- dodecylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide.

[0069] The weight average molecular weight of the acetonitrile-soluble matter of the graft copolymer (A) is not particularly restricted, and is preferably 50,000 or more, and more preferably 60,000 or more. In cases where the weight average molecular weight of the acetonitrile- soluble matter of the graft copolymer (A) is 50,000 or more, the impact resistance of the molded product can be further improved. On the other hand, the weight average molecular weight of the acetonitrile-soluble matter of the graft copolymer (A) is preferably 120,000 or less, and more preferably 100,000 or less. In cases where the weight average molecular weight of the acetonitrile-soluble matterof the graft copolymer (A) is 120,000 or less, the flowability of the final resin composition can be further improved.

[0070] For the weight average molecular weight of the acetonitrile-soluble matter of the graft copolymer (A), acetonitrile-insoluble matter is filtered off from the graft copolymer (A), and the filtrate is concentrated using a rotary evaporator to obtain acetonitrile-soluble matter, about 0.03 g of which is then dissolved in about 15 g of tetrahydrofuran to prepare an about 0.2% by mass solution. Conversion using polystyrene as standard from the GPC chromatogram measured using this solution can give the weight average molecular weight (note that, in cases where a (meth)acrylic ester monomer (a3) is used in the monomer mixture (a), polymethyl methacrylate is used as a standard). The GPC measurement can be performed under the following conditions:Analyzer: Waters 2695Column temperature: 40°CDetector: RI2414 (differential refractometer)Carrier eluent flow rate: 0.3 ml / min (solvent: tetrahydrofuran)Column: TSKgel SuperHZM-M (6.0 mm I.D. x 15 cm) and TSKgel SuperHZM-N (6.0 mm I.D. x 15 cm) in tandem (both produced by Tosoh Corporation).

[0071] The graft ratio of the graft copolymer (A) is not particularly restricted, and is preferably from 10% to 100% from the viewpoint of improving the impact resistance, surface smoothness, and color developability of the molded product. More preferably, the graft ratio is from 30% to 60%.

[0072] Here, the graft ratio of the graft copolymer (A) can be determined by the following method. First, 80 ml of acetonitrile is added to about 1 g of graftcopolymer (A), and refluxed in hot water bath at 70°C for 3 hours. This solution is centrifuged at 8,000 r.p.m (10,000 G) for 40 minutes, and then filtered to remove insoluble matter and obtain acetonitrile-insoluble matter. The resulting acetonitrile- insoluble matter is dried under reduced pressure at 80°C for 5 hours, followed by measurement of its mass (n (in “gram”) in the following equation), and calculation of the graft ratio from the following equation. Here, m is the mass of the graft copolymer (A) used as a sample (in “gram”), and X is the amount of the rubber-like polymer (R) contained in the graft copolymer (A) (% by mass).Graft ratio (%) = { [(n) - ((m) x X / 100)] / [(m) x X / 100] } x 100.

[0073] In the step 1-B, in graft copolymerizing the monomer mixture (a) with the rubber-like polymer (R) latex, the emulsion polymerization method is preferably used because of easy temperature control during polymerization.

[0074] In the step 1-B, various anionic surfactants shown below can be used as emulsifiers used in this graft copolymerization. Anionic surfactants, as used herein, refer to surfactants having an anionic hydrophilic group. As the anionic surfactants, for example, carboxylic acid type, sulfate ester type, sulfonic acid type, sulfosuccinic acid type, and phosphate ester salt type anionic surfactants can be used. Two or more of them may be used. However, some of the emulsifiers described above are incoagulable when contacted with an acid in (Step 1-C) as described below, and thus these emulsifiers will be used to the extent that they can be coagulated with an acid. Among them, carboxylic acid type and sulfosuccinic acid type anionic surfactants are more preferably used, and carboxylic acid type anionic surfactants are still more preferably used, because of their ease of coagulation when contacted with an acid in (Step 1-C).

[0075] Examples of the carboxylic acid type anionic surfactants include fatty acid compounds (G) and disproportionated rosin (F). Among those carboxylic acid type anionic surfactants, fatty acid compounds (G) are most preferably used from the viewpoint of the color tone of the molded product.

[0076] As used herein, the fatty acid compounds (G) are monovalent carboxylic acids having a carboxy group on its hydrocarbon chain, or alkali metal salts thereof or alkaline earth metal salts thereof. Examples include caprylic acid, capric acid, lauric acid, myristic acid, myristoyleic acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, arachidic acid, and pentadecylic acid, and alkali metal salts thereof and alkaline earth metal salts thereof.

[0077] Examples of the sulfate ester type anionic surfactants include castor oil sulfate ester, lauryl alcohol sulfate ester, polyoxyethylene lauryl sulfate, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkylphenyl ether sulfate, and alkali metal salts thereof and alkaline earth metal salts thereof.

[0078] Examples of the sulfonic acid type anionic surfactants include dodecylbenzenesulfonic acid, alkylnaphthalenesulfonic acid, alkyldiphenyl ether disulfonic acid, and naphthalene sulfonic acid condensate, and alkali metal salts thereof and alkaline earth metal salts thereof.

[0079] In cases where a fatty acid compound (G) is used as an emulsifier used in graft copolymerization, a product containing a fatty acid compound (G) may be, for example, hardened tallow fatty acid 45°HFA produced by NOF Corporation, which is preferably used as an alkali metal salt via saponification with potassium hydroxide or the like.

[0080] In the step 1-B, in cases where an anionic surfactant is used, the emulsification stability of the graft copolymer (A) latex during graft copolymerization can be improved.

[0081] In the step 1-B, in cases where a fatty acid compound (G) is used as an emulsifier used in graft copolymerization, the amount of the fatty acid compound (G) added is preferably 1-5 parts by mass, and more preferably 1-3 parts by mass relative to 100 parts by mass of the rubber- like polymer (R) and the monomer mixture (a). In cases where the amount of the fatty acid compound (G) added is less than 1 part by mass relative to 100 parts by mass of the rubber-like polymer (R) and the monomer mixture (a), the emulsification stability may be lowered during graft copolymerization, and thus the cases are undesirable. On the other hand, in cases where the amount of the fatty acid compound (G) added is more than 5 parts by mass relative to 100 parts by mass of the rubber-like polymer (R) and the monomer mixture (a), the color tone of the molded product and the appearance of the molded product may be deteriorated, and thus the cases are undesirable.

[0082] Polymerization initiators used in the graft copolymerization can be the same as illustrated above as initiators used for polymerization of the rubber- like polymer (R).

[0083] In order to adjust the weight average molecular weight and graft ratio of acetonitrile-soluble matter of the graft copolymer (A), a chain transfer agent can also be used. Specific examples of the chain transfer agent include mercaptans, such as n-octyl mercaptan, t-dodecyl mercaptan, n-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan; and terpenes, such as terpinolene. Two or more of them may be used. Especially, n-octyl mercaptan and t-dodecyl mercaptan are preferably used.

[0084] From the viewpoint of adjusting the weight average molecular weight and the graft ratio of acetonitrile- soluble matter of the graft copolymer (A) into the preferred ranges described above, 0.05-0.5 parts by mass of a chain transfer agent, and 0.1-0.5 parts by mass of an initiator are preferably used in graft copolymerization relative to 100 parts by mass in total of the rubber-like polymer (R) and the monomer mixture (a).

[0085] (Step 1 -C) A step of contacting the graft copolymer (A) latex with an acid, which is then neutralized with an alkali, washed with water, and dried to obtain a graft copolymer (A).In this step 1-C, the graft copolymer (A) latex obtained in the step 1-B is contacted with an acid. This acid acts as a coagulating agent. Examples of the acid used as a coagulating agent include sulfuric acid, hydrochloric acid, phosphoric acid, and acetic acid. Two or more of them may be used in combination.

[0086] To remove excess emulsifier, the contact with an acid is followed by neutralization with alkali, washing with water, and drying to obtain a graft copolymer (A). Examples of alkali that can be used for such a treatment to improve the appearance of the molded product include sodium hydroxide.

[0087] In a specific and preferred embodiment, an aqueous solution of an acid adjusted to have a concentration after addition of the graft copolymer (A) latex of about 0.2-2% by mass may be heated to about 50-95°C. To the aqueous solution may be added gradually the graft copolymer (A) latex to allow the graft copolymer (A) latex to contact with the acid so that the concentration of the graft copolymer (A) in the aqueous solution is 8-15% by mass. Then, the resulting mixture may be neutralized with alkali, washed with water, and dried to obtain a graft copolymer (A).

[0088] In the present invention, in cases where the rubber-like polymer (R) latex is obtained by using a sulfosuccinic acid compound (E) and disproportionated rosin (F) at a specific mass ratio as described in the step 1-A section, the ratio of the total mass of anionic surfactants contained in the final resin composition to the total mass of the resin composition can be 5,000 ppm (mass / mass) or less, and a ratio of the total of the sulfosuccinic acid compound (E) represented by the chemical formula [1] and disproportionated rosin (F) contained in the resin composition to the total mass of the resin composition can be 2,000 ppm (mass / mass) or less, by normal water washing operation as described above. This is found to result in successfully obtaining a resin composition having good impact resistance, surface smoothness, color developability, and appearance of the molded product. However, needless to say, water washing operation should be performed to an extent needed. It is noted that, in cases where the rubber-like polymer (R) latex is obtained without use of a sulfosuccinic acid compound (E) and disproportionated rosin (F) at a specific mass ratio, the amount of the emulsifier contained in the resin composition will be excessive.

[0089] The amount of the sulfosuccinic acid compound (E) contained in the graft copolymer (A) is preferably 0.015-0.035% by mass relative to 100% by mass of the graft copolymer (A). In cases where the amount is less than 0.015% by mass, the surface smoothness and color developability of the molded product may be reduced, and thus the cases are undesirable. On the other hand, in cases where the amount of the sulfo succinic acid compound (E) contained in the graft copolymer (A) is more than 0.035% by mass, the impact resistance of the molded product and the appearance of the molded product may be reduced, and thus the cases are undesirable.

[0090] The amount of the disproportionated rosin (F) contained in the graft copolymer(A) is preferably 0.09-0.2% by mass relative to 100% by mass of the graft copolymer(A). In cases where the amount of the disproportionated rosin (F) contained in the graft copolymer (A) is less than 0.09% by mass, the impact resistance of the molded product may be reduced, and thus the cases are undesirable. On the other hand, in cases where the amount of the disproportionated rosin (F) contained in the graft copolymer (A) is more than 0.2% by mass, the surface smoothness, color developability, and appearance of the molded product may be reduced, and thus the cases are undesirable.

[0091] The ratio of the sulfosuccinic acid compound (E) to the disproportionated rosin (F) contained in the graft copolymer (A) by mass is preferably from 10:90 to 30:70 (sulfosuccinic acid compound (E): disproportionated rosin (F)). In cases where the ratio of the sulfosuccinic acid compound (E) to the disproportionated rosin (F) contained in the graft copolymer (A) by mass is from 10:90 to 30:70, the ratio by mass of the sulfosuccinic acid (E) to the disproportionated rosin (F) in the resin composition described later can be easily adjusted into 10:90 to 30:70.

[0092] A vinyl copolymer (B) (Component 2) used in the present invention can be produced by the step 2 described below.

[0093] (Step 2) A step of copolymerizing a monomer mixture (b) comprising at least an aromatic vinyl monomer (bl) and a vinyl cyanide monomer (b2) to obtain a vinyl copolymer (B).A vinyl copolymer (B) used in the resin composition of the present invention is obtained by copolymerization of a monomer mixture (b) comprising at least an aromatic vinyl monomer (bl) and a vinyl cyanide monomer (b2). The monomer mixture (b) may further contain other monomers that are capable of being copolymerized with the aromatic vinyl monomer (bl) and the vinyl cyanide monomer(b2). It is noted that maleimide monomer is not included in the monomer mixture(b).

[0094] Examples of the aromatic vinyl monomer (bl) in the monomer mixture (b) include those illustrated as the aromatic vinyl monomer (al), and styrene is preferable.

[0095] The amount of the aromatic vinyl monomer (bl) contained in the monomer mixture (b) is preferably 60% by mass or more, more preferably 65% by mass or more, and still more preferably 70% by mass or more relative to 100% by mass in total of the monomer mixture (b) from the viewpoint of further improving the flowability of the final resin composition and the stiffness of the molded product. On the other hand, the amount of the aromatic vinyl monomer (bl) contained in the monomer mixture (b) is preferably 85% by mass or less, more preferably 80% by mass or less, and still more preferably 75% by mass or less relative to 100% by mass in total of the monomer mixture (b) from the viewpoint of improving the impact resistance of the molded product.

[0096] Examples of the vinyl cyanide monomer (b2) in the monomer mixture (b) include those illustrated as the vinyl cyanide monomer (a2), and acrylonitrile is preferable.

[0097] The amount of the vinyl cyanide monomer (b2) contained in the monomer mixture (b) is preferably 20% by mass or more, more preferably 25% by mass or more, and still more preferably 30% by mass or more relative to 100% by mass in total of the monomer mixture (b) from the viewpoint of improving the impact resistance of the molded product. On the other hand, the amount of the vinyl cyanide monomer (b2) contained in the monomer mixture (b) is preferably 40% by mass or less, and morepreferably 35% by mass or less relative to 100% by mass in total of the monomer mixture (b) from the viewpoint of improving the flowability of the final resin composition and the color tone of the molded product.

[0098] The other monomers that are capable of being copolymerized with the aromatic vinyl monomer (bl) and the vinyl cyanide monomer (b2) described above are not particularly restricted, as long as they are vinyl monomers other than the aromatic vinyl monomer (bl) and vinyl cyanide monomer (b2) described above, which do not impair the effect of the present invention. Specific examples of the other monomers include (meth)acrylic ester monomers (b3), unsaturated fatty acids, and acrylamide monomers, two or more of which may be used. The (meth)acrylic ester monomer (b3) may be the same as that described for the (meth)acrylic ester monomer (a3) described above. Examples of the unsaturated fatty acid include itaconic acid, maleic acid, fumaric acid, butenoic acid, acrylic acid, and methacrylic acid. Examples of the acrylamide monomer include acrylamide, methacrylamide, and N-methylacrylamide.

[0099] The weight average molecular weight of the vinyl copolymer (B) is preferably 70,000 or more, and more preferably 80,000 or more. In cases where the weight average molecular weight of the vinyl copolymer (B) is 70,000 or more, the impact resistance of the molded product can be further improved. On the other hand, the weight average molecular weight of the vinyl copolymer (B) is preferably 200,000 or less, and more preferably 150,000 or less. In cases where the weight average molecular weight of the vinyl copolymer (B) is 200,000 or less, the flowability of the final resin composition can be further improved. A vinyl copolymer (B) with a weight average molecular weight ranging from 70,000 to 200,000 can be easily produced, for example, by using an initiator or a chain transfer agent described below, or setting the polymerization temperature to be within the preferred range describedbelow.

[0100] Here, the weight average molecular weight of the vinyl copolymer (B) can be determined as follows. About 0.03 g of the vinyl copolymer (B) is dissolved in about 15 g of tetrahydrofuran to obtain about 0.2% by mass solution. Conversion using polystyrene as standard from the GPC chromatogram measured using this solution can give the weight average molecular weight (note that, in cases where a (meth)acrylic ester monomer (b3) is used in the monomer mixture (b), polymethyl methacrylate is used as a standard). The GPC measurement can be performed under the following conditions:Analyzer: Waters 2695Column temperature: 40°CDetector: RI2414 (differential refractometer)Carrier eluent flow rate: 0.3 ml / min (solvent: tetrahydrofuran)Column: TSKgel SuperHZM-M (6.0 mm I.D. x 15 cm) and TSKgel SuperHZM-N (6.0 mm I.D. x 15 cm) in tandem (both produced by Tosoh Corporation).

[0101] The method for producing the vinyl copolymer (B) is not particularly restricted, and the continuous bulk polymerization or continuous solution polymerization method is preferably used from the viewpoint of the moldability of the resulting final resin composition and the color tone of the molded product. Here, the continuous bulk polymerization method is a method in which a monomer mixture (b) is continuously fed over time, and a bulk polymerized vinyl copolymer (B) is continuously discharged over time. The continuous solution polymerization method is a method in which a monomer mixture (b) and a solvent are continuously added fed over time, and a solution composed of a solution polymerized vinyl copolymer (B) and the solvent is continuously discharged over time.

[0102] An arbitrary method can be used to produce a vinyl copolymer (B) by the continuous bulk polymerization method or continuous solution polymerization method, including, for example, those comprising polymerizing a monomer mixture (b) in a polymerization tank, and then removing monomers (removal of solvent and devolatilization).

[0103] Examples of the polymerization tank that can be used include mixing-type polymerization tanks having an agitating blade such as a paddle blade, turbine blade, propeller blade, brumargin blade, multistage blade, anchor blade, MAXBLEND blade, or double-helical blade; and various column type reactors. In addition, a multitube reactor, kneader type reactor, a twin screw extruder, or the like can be used as a polymerization reactor (for example, see “Assessment of Impact- resistant Polystyrene,” Assessment of Polymer Production Process 10, The Society of Polymer Science, Japan (Jan. 26, 1989)).

[0104] In production of a vinyl copolymer (B), two or more polymerization tanks or polymerization reactors described above may be used, and, as necessary, two or more types of polymerization tanks or polymerization reactors may be combined. From the viewpoint of reducing the molecular weight distribution of a vinyl copolymer (B), the number of the polymerization tanks or polymerization reactors is preferably two or less, and a single-tank complete mixing polymerization tank is more preferable.

[0105] A reaction mixture obtained by polymerization in such a polymerization tank or polymerization reactor is then usually subjected to a monomer removal step, in which monomers, solvents, and other volatile components will be removed. Examples of the method for removing monomer include a method in which a singlescrew or twin screw extruder having a vent is used to remove a volatile component through the vent hole under heating, under normal or reduced pressure; a method in which an evaporator having a plate-fin heater, such as a centrifugal type, built in a drum is used to remove a volatile component; a method in which a thin-film evaporator, such as a centrifugal type, is used to remove a volatile component; and a method in which the reaction mixture is preheated and foamed using a multipipe heat exchanger, and then flushed into a vacuum chamber to remove a volatile component. Among the methods of removing monomer, a method in which a single screw or twin screw extruder having a vent is used to remove a volatile component is particularly preferably used.

[0106] In cases where a vinyl copolymer (B) is produced, an initiator or a chain transfer agent may be used appropriately. Examples of the initiator and chain transfer agent include the same as those illustrated in the method of producing a graft copolymer (A).

[0107] The added amount of the initiator used to produce the vinyl copolymer (B) is not particularly restricted, and is preferably from 0.01 parts by mass to 0.03 parts by mass relative to 100 parts by mass in total of the monomer mixture (b) from the viewpoint of ease of adjusting the weight average molecular weight of the vinyl copolymer (B) into the range as described above.

[0108] The added amount of the chain transfer agent used to produce the vinyl copolymer (B) is not particularly restricted, and is preferably from 0.05 parts by mass to 0.40 parts by mass relative to 100 parts by mass in total of the monomer mixture (b) from the viewpoint of ease of adjusting the weight average molecular weight of the vinyl copolymer (B) into the range as described above.

[0109] In cases where the vinyl copolymer (B) is produced by the continuous bulk polymerization method or continuous solution polymerization method, the polymerization temperature is not particularly restricted, and is preferably from 120°C to 140°C from the viewpoint of ease of adjusting the weight average molecular weight of the vinyl copolymer (B) into the range as described above.

[0110] In cases where the vinyl copolymer (B) is produced by the continuous solution polymerization method, the amount of the solvent in the polymer solution is preferably 30% by mass or less, and more preferably 20% by mass or less, from the viewpoint of productivity. The solvent used is preferably ethylbenzene or methyl ethyl ketone, and especially preferably ethylbenzene, from the viewpoint of polymerization stability

[0111] The heat-resistant vinyl copolymer (C) used in the present invention can be produced by the step 4 described below.

[0112] (Step 4) A step of copolymerizing a monomer mixture (c) comprising at least an aromatic vinyl monomer (cl) and a maleimide monomer (c2) to obtain a heat-resistant vinyl copolymer (C).The resin composition of the present invention can optionally comprise a heat- resistant vinyl copolymer (C) obtained by copolymerizing a monomer mixture (c) comprising at least an aromatic vinyl monomer (cl) and a maleimide monomer (c2). Inclusion of a heat-resistant vinyl copolymer (C) can impart heat resistance to the final resin composition.

[0113] Examples of the aromatic vinyl monomer (cl) in the monomer mixture (c) include those illustrated as the aromatic vinyl monomer (al), and styrene is preferable.

[0114] Examples of the maleimide monomer (c2) in the monomer mixture (c) include N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide, N-octylmaleimide, N-dodecylmaleimide, N-cyclohexylmaleimide, and N- phenylmaleimide, and corresponding maleic acids and maleic anhydrides (in cases where maleic acid or maleic anhydride is used, imidization with an amine compound is performed before or after copolymerization of the monomer mixture (c)). Two or more of them may be contained as maleimide monomers (c2). Among those maleimide monomers (c2), N-phenylmaleimide is preferable from the viewpoint of improving the heat resistance of the final resin composition.

[0115] Other monomers than the aromatic vinyl monomer (cl) or maleimide monomer (c2) described above may also be contained in the monomer mixture (c) as long as they do not impair the object of the present invention. Specific examples of such other monomers include vinyl cyanide monomers (c3), unsaturated fatty acids, and acrylamide monomers, two or more of which may be used.

[0116] Examples of the vinyl cyanide monomer (c3) in the monomer mixture (c) include those illustrated as the vinyl cyanide monomer (a2), and acrylonitrile is preferable.

[0117] The composition ratio of the monomers in the monomer mixture (c) used in the heat-resistant vinyl copolymer (C) is not particularly restricted, and is preferably as follows: 36-65% by mass of the aromatic vinyl monomer (cl), 35-52% by mass, preferably 37-50% by mass, of the maleimide monomer (c2), and 0-12% by mass of the vinyl cyanide monomer (c3), when considering the total amount of the monomer mixture (c) as 100% by mass. In particular, in cases where the maleimide monomer(c2) content is less than 35% by mass, the final resin composition has less effect of improving the heat resistance, while in cases of more than 52% by mass, the final resin composition may have impaired moldability.

[0118] The reduced viscosity of a 0.4 g / dl solution of the heat-resistant vinyl copolymer (C) in dimethyl sulfoxide at 30°C as measured by Ubbelohde viscometer is preferably from 0.3 to 0.7 dl / g, and more preferably from 0.4 to 0.6 dl / g. In cases where the reduced viscosity of the heat-resistant vinyl copolymer (C) is less than 0.3 dl / g, the impact resistance of the molded product may be reduced, while in cases of more than 0.7 dl / g, the final resin composition may exhibit reduced flowability and moldability.

[0119] The final resin composition of the present invention can be produced by the step 3 described below. The final resin composition in the step 3 will contain a sulfosuccinic acid compound (E) (Component 3) and disproportionated rosin (F) (Component 4).

[0120] (Step 3) A step of mixing the graft copolymer (A) and vinyl copolymer (B) obtained in the steps 1 and 2, and the heat-resistant vinyl copolymer (C) obtained in the step 4 (here, the heat-resistant vinyl copolymer (C) is an optional component).For the step of mixing the graft copolymer (A), vinyl copolymer (B), and heat- resistant vinyl copolymer (C) (here, the heat-resistant vinyl copolymer (C) is an optional component), the melt kneading method is not particularly restricted, and for example, methods can be used in which melting and kneading are performed by using a single or twin screw in a cylinder with a heater and a vent. The heating temperature for melt kneading is usually selected from a range of 210-320°C, and for example, the temperature gradient during melt kneading can also be arbitrarily set as long as theydo not impair the object of the present invention. In cases where twin screws are used, the rotation directions may be the same or different.

[0121] The resin composition of the present invention preferably contains and is formed with 10 parts by mass or more and 60 parts by mass or less of the graft copolymer (A) and 40 parts by mass or more and 90 parts by mass or less of the vinyl copolymer (B) relative to 100 parts by mass of the total of the graft copolymer (A) and the vinyl copolymer (B). By containing 10 parts by mass or more of the graft copolymer (A) content and 90 parts by mass or less of the vinyl copolymer (B), the reduction of the impact resistance of the molded product can be prevented. Inclusion of 20 parts by mass or more of the graft copolymer (A) and 80 parts by mass or less of the vinyl copolymer (B) relative to 100 parts by mass of the total of the graft copolymer(A) and the vinyl copolymer (B) is more preferable. Inclusion of 60 parts by mass or less of the graft copolymer (A) and 40 parts by mass or more of the vinyl copolymer(B) can prevent the melt viscosity of the final resin composition from being increased, while preventing the reduction of the flowability, as well as of the surface smoothness, color developability, and appearance of the molded product. Inclusion of 50 parts by mass or less of the graft copolymer (A) and 50 parts by mass or more of the vinyl copolymer (B) relative to 100 parts by mass of the total of the graft copolymer (A) and the vinyl copolymer (B) is more preferably contained. For the graft copolymer (A), two or more graft copolymers (A) may be contained, e.g., use of graft copolymers (A) using different rubber-like polymers (R). Similarly, for the vinyl copolymer (B), two or more vinyl copolymers (B) may be contained.

[0122] The amount of the rubber-like polymer (R) contained in the resin composition of the present invention is preferably from 10 to 35% by mass, more preferably from 15 to 30% by mass, and still more preferably from 15 to 25% by mass, relative to 100%by mass of the total of all resin components. In cases where the amount of the rubberlike polymer (R) contained is 10% by mass or more relative to 100% by mass in total of all resin components, the impact resistance of the molded product can be further improved. On the other hand, in cases where the amount of the rubber-like polymer (R) contained relative to 100% by mass in total of all resin components is 35% by mass or less, the flowability of the final resin composition, and the surface smoothness, color developability, and appearance of the molded product can be further improved.

[0123] In cases where the resin composition of the present invention contains a heat- resistant vinyl copolymer (C), the amount is preferably from 10 to 38% by mass, more preferably from 12 to 36% by mass, and still more preferably from 15 to 35% by mass relative to 100% by mass in total of all resin components. In cases where the amount is within such ranges, the effect of improving the heat resistance of the molded product is further enhanced, and the improvement of the impact resistance of the molded product and of the flowability of the final resin composition is also still further prominent.

[0124] In the resin composition of the present invention, the ratio of the total amount of anionic surfactants to the total amount of the resin composition is 5,000 ppm (mass / mass) or less, and more preferably 3,500 ppm (mass / mass) or less. Anionic surfactants are surfactants whose hydrophilic group moiety will be a negative ion in water. In cases where the ratio of the total amount of anionic surfactants to the total amount of the resin composition is more than 5,000 ppm (mass / mass), the appearance of the molded product is significantly reduced.

[0125] In the resin composition of the present invention, the ratio of the total amount of the sulfosuccinic acid compound (E) and disproportionated rosin (F) to the totalamount of the resin composition is 2,000 ppm (mass / mass) or less, and more preferably 1,500 ppm (mass / mass) or less. In cases where the ratio of the total amount of the sulfosuccinic acid compound (E) and disproportionated rosin (F) to the total amount of the resin composition is more than 2,000 ppm (mass / mass), the appearance of the molded product is significantly reduced.

[0126] In the resin composition of the present invention, the ratio of the sulfosuccinic acid compound (E) to the disproportionated rosin (F) by mass is from 10:90 to 30:70 (sulfosuccinic acid compound (E): disproportionated rosin (F)), and more preferably from 10:90 to 20:80 by mass. In cases where the sulfosuccinic acid compound (E) is contained in a mass ratio of less than 10:90 relative to 100% by mass of the total amount of the sulfo succinic acid compound (E) and disproportionated rosin (F), the surface smoothness and color developability of the molded product is reduced. On the other hand, in cases where the sulfosuccinic acid compound (E) is contained in a mass ratio of more than 30:70 relative to 100% by mass of the total amount of the sulfosuccinic acid compound (E) and disproportionated rosin (F), the impact resistance of the molded product is reduced, and in addition the appearance of the molded product is reduced.

[0127] The resin composition of the present invention can contain, without impairing the object of the present invention, for example, inorganic fillers, such as glass fiber, glass powder, glass bead, glass flake, alumina, alumina fiber, carbon fiber, graphite fiber, stainless fiber, whisker, potassium titanate fiber, wollastonite, asbestos, hard clay, calcined clay, talc, kaolin, mica, calcium carbonate, magnesium carbonate, aluminum oxide, and minerals; impact modifiers, such as silicone compounds; antioxidants, such as hindered phenol compounds, sulfur-containing compounds, and phosphorus -containing organic compounds; heat stabilizers, such as phenol andacrylate heat stabilizers; ultraviolet absorbers, such as benzotriazole, benzophenone, and salicylates; hindered amine light stabilizers; lubricants and plasticizers, such as higher fatty acids, acid esters, acid amides, and higher alcohols; mold release agents, such as montanoic acid, and salts, esters, and half esters thereof, stearyl alcohol, stearamide, and ethylene wax; various flame retardants; flame retardant promoters; coloring inhibitors, such as phosphites and hypophosphites; neutralizers, such as phosphoric acid, sodium phosphate, monobasic, maleic anhydride, and succinic anhydride; nucleating agents; antistatic agents, such as amine, sulfonic acid, and polyether antistatic agents; colorants, such as carbon black, pigments, and dyes; and blueing agents.

[0128] The resin composition of the present invention can be molded by an arbitrary molding method to obtain a molded product. Examples of the molding method include injection molding, extrusion molding, inflation molding, blow molding, vacuum molding, compression molding, and gas-assisted molding, and preferably injection molding is used. The temperature of the cylinder during injection molding is preferably from 210°C to 320°C, and the temperature of the mold is preferably from 30°C to 80°C.

[0129] The resin composition of the present invention can be broadly used as a molded product with an arbitrary shape. Examples of the molded product include films, sheets, fibers, cloths, nonwoven fabrics, injection-molded products, extrusion molded products, vacuum / compressed air molded products, blow molded products, and composites with other materials.

[0130] The resin composition of the present invention can provide a resin composition with good impact resistance, surface smoothness, color developability, and appearanceof the molded product, and thus is useful for applications such as home appliances, communication-related equipment, sundries, and automotive materials. A resin composition containing a heat-resistant vinyl copolymer imparted with heat resistance has both flowability and impact resistance suitable for large molded products, and is excellent in the appearance of the molded product, and thus can be particularly suitably used, for example, for rear spoilers, hubcaps, door mirrors, radiator grilles, and lamp housings for automotive exteriors; and power window panels, center consoles, center clusters, lever controllers, and console boxes for automotive interiors.Examples

[0131] The present invention will be described in more detail below with reference to examples, but should not be construed as limited to them. First, the evaluation methods will be described.

[0132] (1) Volume Mean Particle Diameter of Rubber-like Polymer (R)A rubber-like polymer (R) latex was diluted with and dispersed in an aqueous medium, and then the particle size distribution was measured with a laser scattering diffraction particle size distribution analyzer “LS 13 320XR” (Beckman Coulter, Inc.). Based on the particle size distribution, the volume mean particle diameter of the rubber-like polymer (R) was determined.

[0133] (2) Graft Ratio of Graft Copolymer (A)To about 1 g of graft copolymer (A) was added 80 ml of acetonitrile, and the mixture was refluxed in hot water bath at 70°C for 3 hours. This solution was centrifuged at 8,000 r.p.m (10,000 G) for 40 minutes, and then filtered to remove insoluble matter and obtain acetonitrile-insoluble matter. The resulting acetonitrile-insoluble matter was dried under reduced pressure at 80°C for 5 hours, followed by measurement of its mass (n (in “gram”) in the following equation), and calculation of the graft ratio from the following equation. Here, m is the mass of the graft copolymer (A) used as a sample (in “gram”), and X is the amount of the rubber-like polymer contained in the graft copolymer (A) (% by mass).Graft ratio (%) = { [(n) - ((m) x X / 100)] / [(m) x X / 100] } x 100.

[0134] (3) Amounts of Sulfosuccinic Acid Compound (E), Disproportionated Rosin (F), and Other Anionic Surfactants (e.g., Fatty Acid Compound (G)) Contained in Resin CompositionTo 0.1 g of resin compositions were added 10 ml of chloroform, followed by incubation for 12 hours. Thereafter, ultrasonication was performed for 1 hour. Then, 0.1 mF of the prepared solutions were collected in micro test tubes. To the prepared solutions, were added 0.9 mF of methanol containing 1 vol% formic acid for 1:10 dilution, followed by vigorous stirring. Thereafter, the resulting mixtures were centrifuged (15,000 G) for 15 minutes, and the supernatants were used to prepare sample solutions.

[0135] EC / MS analysis was performed under the following conditions. The top two molecular species to be measured with the highest content are selected as monitor ions. Using pre-prepared calibration curves for standard solutions of the surfactants for the monitor ions, the amounts of the sulfosuccinic acid compound (E), disproportionated rosin (F), and other anionic surfactants (e.g., fatty acid compound (G)) contained in the resin composition were determined. For the amounts of the sulfosuccinic acid compound (E), disproportionated rosin (F), and other anionic surfactants (e.g., fatty acid compound (G)) contained in the resin composition, the higher value of the amounts determined for the two monitor ions was employed. Measurementconditions for sulfosuccinic acid compound (E):HPLC: LC-20A [manufactured by Shimadzu Corporation]Mass spectrometer: API5000 [manufactured by SCIEX]Column: ODS columnMobile phase:A. 10 mmol / L aqueous ammonium acetate solutionB. acetonitrileGradient conditionsInjection amount: 3 pLIonization: APCIDetection: Negative ion detectionMeasurement mode: SRM (Selected reaction monitoring)Monitor ions: n-dodecylsulfosuccinic acid *(Q1 m / z 365.2, Q3 m / z 81.0) monopolyoxyethylene-n-dodecylsulfosuccinic acid *(Q1 m / z 409.2, Q3 m / z 81.0)*[M-H]“ was set as a monitor ionMeasurement conditions for disproportionated rosin (F):HPLC: LC-20A [manufactured by Shimadzu Corporation]Mass spectrometer: API5000 [manufactured by AB Sciex Pte. Ltd.]Column: ODS columnMobile phase:A. 10 mmol / L aqueous ammonium acetate solutionB. acetonitrileGradient conditionsInjection amount: 3 pLIonization: APCIDetection: negative ion detectionMeasurement mode: SRM (Selected reaction monitoring)Monitor ion dehydroabietic acid *(Q1 m / z 299.2, Q3 m / z 299.2) dihydroabietic acid *(Q1 m / z 303.2, Q3 m / z 303.2)*[M-H]“ was set as a monitor ionMeasurement conditions for other anionic surfactants (fatty acid compound (G)) used in Examples and Comparative Examples:HPLC: LC-20A [manufactured by Shimadzu Corporation]Mass spectrometer: API5000 [manufactured by AB Sciex Pte. Ltd.]Column: ODS columnMobile phase:A. 5 mmol / L aqueous ammonium acetate solutionB. methanol-tetrahydrofuran (1:1)Gradient conditionsInjection amount: 5 pLIonization: APCIDetection: negative ion detectionMeasurement mode: SRM (Selected reaction monitoring)Monitor ion: oleic acid *(Q1 m / z 281.2, Q3 m / z 281.2) palmitic acid *(Q1 m / z 255.2, Q3 m / z 255.2)*[M-H]“ was set as a monitor ion

[0136] In cases where other anionic surfactants than the fatty acid compound (G) used in Examples and Comparative Examples, the top two molecular species to be measured with the highest content contained in the other anionic surfactants are selected asmonitor ions as described above, and the other anionic surfactants content is determined in the same manner as described above.

[0137] (4) Evaluation of Impact Resistance (Charpy Impact Strength)Resin composition pellets as samples were dried in a hot-air drier at 80°C for 3 hours, supplied into a molding machine, SE-50DU, manufactured by Sumitomo Heavy Industries, Ltd. with the cylinder temperature set at 230°C, and molded into dumbbell specimens having a thickness of 4 mm at a mold temperature of 60°C and a molding cycle of 30 seconds. The Charpy impact strength of the resulting 5 dumbbell specimens was measured by a method according to ISO 179, and the number average value was calculated.

[0138] (5) Evaluation of Surface Smoothness (Glossiness)Resin composition pellets as samples were dried in a hot-air drier at 80°C for 3 hours, supplied into a molding machine, SE-50DU, manufactured by Sumitomo Heavy Industries, Ltd. with the cylinder temperature set at 250°C, and molded into rectangular plate molded products (90 mm long, 50 mm wide, 2.5 mm thick) at an injection rate of 50 mm / s, a mold temperature of 60°C, and a molding cycle of 20 seconds. The glossiness at 20° of the resulting 5 rectangular plate molded products was measured according to JISZ8741 (established in 1997), and the number average value was calculated.

[0139] (6) Evaluation of Color Developability (L value)Resin composition pellets as samples were dried in a hot-air drier at 80°C for 3 hours, supplied into a molding machine, SE-50DU, manufactured by Sumitomo Heavy Industries, Ltd. with the cylinder temperature set at 250°C, and molded into rectangular plate molded products (90 mm long, 50 mm wide, 2.5 mm thick) at aninjection rate of 50 mm / s, a mold temperature of 60°C, and a molding cycle of 20 seconds. The L values of the resulting 5 rectangular plate molded products were measured according to JIS K7103 (established in 1971), and the number average value was calculated. It is noted that lower L values represent better results.

[0140] (7) Evaluation of Appearance of Molded Product (Mold Fouling Properties)Resin composition pellets as samples were dried in a hot-air drier at 80°C for 3 hours, supplied into a molding machine, PS-60E, manufactured by Nissei Plastic Industrial Co., Ltd. with the cylinder temperature set at 280°C, and injection molded into 1,000 shots of rectangular plate molded products (100 mm long, 120 mm wide, 3 mm thick) at a mold temperature of 60°C and a molding cycle of 30 seconds, followed by evaluation of the mold fouling properties according to the following criteria. It is noted that A is the best result.No change in the mold surface: ACloudy mold surface: BFouled mold surface and poor appearance of the molded product: C

[0141] (8) Evaluation of Heat ResistanceResin composition pellets as samples were dried in a hot-air drier at 80°C for 3 hours, supplied into a molding machine, SE-50DU, manufactured by Sumitomo Heavy Industries, Ltd. with the cylinder temperature set at 230°C, and molded into dumbbell specimens having a thickness of 4 mm at a mold temperature of 60°C and a molding cycle of 30 seconds. The heat distortion temperatures of the resulting 3 dumbbell specimens were measured according to ISO75-2 (established in 2004, loading condition: 1.8 MPa), and the number average value was calculated.

[0142] (9) Evaluation of MorphologyResin composition pellets as samples were dried in a hot-air drier at 80°C for 3 hours, supplied into a molding machine, SE-50DU, manufactured by Sumitomo Heavy Industries, Ltd. with the cylinder temperature set at 230°C, and molded into dumbbell specimens having a thickness of 4 mm at a mold temperature of 60°C and a molding cycle of 30 seconds. The resulting dumbbell specimens, prepared by osmic acid staining, were observed for morphology at 2500x using a transmission electron microscope (TEM), HT7700, manufactured by Hitachi High-Tech Corporation, and observed for the presence of rubber, that is the rubber-like polymer (R), with large particle diameters of more than 1 pm. It is noted that the black areas in the TEM image represent the rubber-like polymer (R). The other white areas represent components other than the rubber- like polymer (R).

[0143] The surfactants used in Examples and Comparative Examples are as follows. Sulfosuccinic acid compound (E):•Aqueous solution of KOHACOOL L-300 produced by TOHO Chemical Industry Co., Ltd. (solid content concentration: 30% by mass) (E-l)Disproportionated rosin (F):•Aqueous solution of DIPROSIN K-25 produced by TOHO Chemical Industry Co., Ltd. (solid content concentration: 25% by mass) (F-l)Other anionic surfactants:(Fatty acid compound (G))•In a 30-L reactor equipped with a stirrer, 3.2 parts by mass of potassium hydroxide was dissolved in 81 parts by mass of pure water, and the aqueous solution was heated to 80°C. Then, 15.7 parts by mass of hardened tallow fatty acid 45° produced by NOF Corporation was added for 30 minutes, and then the mixture was stirred for 2 hours to obtain an aqueous fatty acid compound solution (solid content concentration: 18% by mass) (G-l) as “other anionic surfactant.”(Other anionic surfactant (H) than fatty acid compound (G)):•Aqueous solution of ALSCOAP TH-33OK produced by TOHO Chemical Industry Co., Ltd. (generic name: sodium polyoxyethylene lauryl ether sulfate) (solid content concentration: 27% by mass) (H-l)•Aqueous solution of ALSCOAP LS-30 produced by TOHO Chemical Industry Co., Ltd. (generic name: sodium lauryl sulfate) (solid content concentration: 30% by mass) (H-2)•Paste of NEOPELEX G-65 produced by Kao Corporation (generic name: sodium dodecylbenzenesulfonate) (solid content concentration: 65% by mass) (H-3).

[0144] (Production Example 1) Rubber- like Polymer (R-l) and Graft Copolymer (A-l)To a 20-m3reactor equipped with a stirrer were fed 140 parts by mass of pure water (including water contained in the emulsifiers), 0.2 parts by mass based on the solid content, i.e., (0.2 x (1 / 0.3)) parts by mass as an aqueous solution, of an aqueous KOHACOOL L-300 solution (E-l) and 0.7 parts by mass based on the solid content of an aqueous DIPROSIN K-25 solution (F-l) as emulsifiers, and 0.1 parts by mass of sodium hydroxide, followed by replacement by nitrogen inside the reactor. Thereafter, the temperature was raised to 62°C, and a mixture of 14.9 parts by mass of n-butyl acrylate and 0.1 parts by mass of allyl methacrylate was added for 30 minutes at a constant rate under stirring. Then, 0.2 parts by mass (based on the solid content) of a 2% by mass aqueous potassium persulfate solution was added for 4.75 hours at a constant rate to initiate polymerization. After 1.75 hours from the start of addition of the aqueous potassium persulfate solution, a mixture of 42.3 parts by mass of n-butyl acrylate and 0.2 parts by mass of allyl methacrylate was added for 1.25 hours at a constant rate, and then additionally a mixture of 41.6 parts by mass of n-butyl acrylate and 0.9 parts by mass of allyl methacrylate was added for 1.25 hours at a constant rate. In addition, after 3 hours from the start of addition of the potassium persulfate solution,0.8 parts by mass based on the solid content of an aqueous DIPROSIN K-25 solution (F-l) was added for 1.75 hours at a constant rate. During the period, the temperature was raised to 65°C 2.25 hours after the start of addition of the aqueous potassium persulfate solution, raised to 68°C 3 hours after the start of addition of the aqueous potassium persulfate solution, and raised to 70°C 4 hours after the start of addition of the aqueous potassium persulfate solution. After completion of addition of the aqueous potassium persulfate solution and retention for 0.5 hours, a rubber-like polymer (R-l) latex was obtained.

[0145] Thereafter, to 50 parts by mass based on the solid content of the rubber-like polymer (R-l) latex, a mixture of 0.48 parts by mass of anhydrous dextrose, 0.26 parts by mass of sodium pyrophosphate, and 0.01 parts by mass of ferrous sulfate, 0.7 parts by mass based on the solid content of an aqueous fatty acid compound solution (G-l) as an emulsifier, and 115 parts by mass of pure water (including water contained in the rubber- like polymer (R-l) latex and the emulsifier) were fed in the reactor. After replacement by nitrogen and cooling to 60°C, a mixture of 6.6 parts by mass of styrene, 2.4 parts by mass of acrylonitrile, and 0.043 parts by mass of t-dodecylmercaptan was added for 30 minutes under stirring.

[0146] Next, an initiator mixture of 0.17 parts by mass of cumene hydroperoxide, 1.0 part by mass (based on the solid content) of an aqueous fatty acid compound (G-l) solution as an emulsifier, and 8 parts by mass of pure water (including water contained in the aqueous fatty acid compound solution (G-l) as an emulsifier) was added dropwise for 3.5 hours. Then, an initiator mixture of 0.17 parts by mass of cumene hydroperoxide, 0.2 parts by mass (based on the solid content) of an aqueous fatty acid compound solution (G-l) as an emulsifier, and 3.5 parts by mass of pure water (including water contained in the aqueous fatty acid compound solution (G-l) as anemulsifier) was added for 1.5 hours. The dropwise addition was performed for 5 hours in total. Starting at the same time as and progressing in parallel with this dropwise addition, a mixture of 29.9 parts by mass of styrene, 11.1 parts by mass of acrylonitrile, and 0.20 parts by mass of t-dodecylmercaptan was added dropwise for 3.5 hours. During the period, the temperature was raised to 62 °C at the same time as the start of addition of the initiator mixture, and raised to 65 °C 3.5 hours after the start of addition of the initiator mixture. At the point of completion of dropwise addition of the initiator mixture, the polymerization was completed. After the completion of polymerization, the product was cooled to 40°C with stirring, and 0.75 parts by mass of phenol, 4-methyl-, reaction products with dicyclopentadiene and isobutylene (in other words, butylated reaction product of p-cresol and dicyclopentadiene (CAS Reg. No. 68610-51-5)) and 0.2 parts by mass of PHOSPHANOL SC-6103L produced by TOHO Chemical Industry Co., Ltd. (main component: polyoxyethylene alkyl ether phosphoric acid calcium salt) were added to obtain a graft copolymer (A-l) latex. Thereafter, the resulting graft copolymer (A-l) latex was poured into dilute sulfuric acid at 60°C with stirring with the concentration after addition of the graft copolymer (A-l) latex adjusted to 0.38% by mass. After the addition and temperature rise to 93 °C for coagulation, the mixture was neutralized with 3.5 parts by mass based on the solid content of a 20% by mass aqueous sodium hydroxide solution, washed with water, centrifuged, and dried to obtain a graft copolymer (A-l). The volume mean particle diameter of the resulting rubber-like polymer (R-l) was 0.125 pm. The graft ratio of the graft copolymer (A-l) was 38%.

[0147] (Production Example 2) Rubber-like Polymer (R-2) and Graft Copolymer (A-2)A rubber-like polymer (R-2) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) basedon the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 1.2 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-2) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-2) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A-2) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber- like polymer (R-2) was 0.13 pm. The graft ratio of the graft copolymer (A-2) was 36%.

[0148] (Production Example 3) Rubber-like Polymer (R-3) and Graft Copolymer (A-3)A rubber-like polymer (R-3) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 2.2 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-3) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-3) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A-3) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber-like polymer (R-3) was 0.145 pm. The graft ratio of the graft copolymer (A-3) was 34%.

[0149] (Production Example 4) Rubber-like Polymer (R-4) and Graft Copolymer (A-4)A rubber-like polymer (R-4) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.3 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-4) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-4) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A-4) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber- like polymer (R-4) was 0.105 pm. The graft ratio of the graft copolymer (A-4) was 41%.

[0150] (Production Example 5) Rubber-like Polymer (R-5) and Graft Copolymer (A-5)A rubber-like polymer (R-5) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.3 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 1.2 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-5) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-5) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A-5) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber-like polymer (R-5) was 0.11 pm. The graft ratio of the graftcopolymer (A-5) was 39%.

[0151] (Production Example 6) Rubber-like Polymer (R-6) and Graft Copolymer (A-6)A rubber-like polymer (R-6) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.3 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 2.2 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-6) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-6) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A-6) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber-like polymer (R-6) was 0.125 pm. The graft ratio of the graft copolymer (A-6) was 37%.

[0152] (Production Example 7) Rubber-like Polymer (R-7) and Graft Copolymer (A-7)A rubber-like polymer (R-7) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.4 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-7) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-7) latex was used instead of therubber- like polymer (R-l) latex. Then, a graft copolymer (A-7) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber- like polymer (R-7) was 0.1 pm. The graft ratio of the graft copolymer (A-7) was 43%.

[0153] (Production Example 8) Rubber-like Polymer (R-8) and Graft Copolymer (A-8)A rubber-like polymer (R-8) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.4 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 2.2 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-8) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-8) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A-8) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber- like polymer (R-8) was 0.105 pm. The graft ratio of the graft copolymer (A-8) was 42%.

[0154] (Production Example 9) Rubber-like Polymer (R-9) and Graft Copolymer (A-9)A rubber-like polymer (R-9) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 1.7 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and that the emulsifieradded 3 hours after the start of addition of an aqueous potassium persulfate solution (0.8 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) was changed to 0.8 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content. Thereafter, a graft copolymer (A-9) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-9) latex was used instead of the rubber-like polymer (R-l) latex. Then, a graft copolymer (A-9) was obtained in the same manner as in Production Example 1 except that the graft copolymer (A-9) latex was used instead of the graft copolymer (A-l) latex, and an aqueous calcium chloride solution with the concentration after addition of the latex adjusted to 0.3% by mass was used instead of dilute sulfuric acid with the concentration after addition of the latex adjusted to 0.38% by mass. The volume mean particle diameter of the resulting rubber-like polymer (R-9) was 0.09 pm. The graft ratio of the graft copolymer (A-9) was 45%. The use of an aqueous calcium chloride solution was due to failure of coagulation with dilute sulfuric acid.

[0155] (Production Example 10) Rubber- like Polymer (R-10) and Graft Copolymer (A- 10)A rubber-like polymer (R-10) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 1.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A- 10) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-10) latex was used instead of the rubber-like polymer (R-l) latex. Then, a graft copolymer (A-10) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber- like polymer (R-10) was 0.16 pm. The graft ratio of the graftcopolymer (A- 10) was 25%.

[0156] (Production Example 11) Rubber- like Polymer (R-l 1) and Graft Copolymer (A- 11)A rubber-like polymer (R-l 1) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.1 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 0.4 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-l l) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-l l) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A-l l) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber-like polymer (R-l l) was 0.165 pm. The graft ratio of the graft copolymer (A-l l) was 27%.

[0157] (Production Example 12) Rubber- like Polymer (R-12) and Graft Copolymer (A- 12)A rubber-like polymer (R-12) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.1 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 1.2 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A- 12) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-12) latex was used instead of therubber-like polymer (R-l) latex. Then, a graft copolymer (A-12) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber-like polymer (R-12) was 0.145 pm. The graft ratio of the graft copolymer (A-12) was 44%.

[0158] (Production Example 13) Rubber- like Polymer (R-l 3) and Graft Copolymer (A- 13)A rubber-like polymer (R-13) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.5 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 1.2 parts by mass (solid content equivalent) of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-13) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-13) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A- 13) was obtained in the same manner as in Production Example 1 except that the graft copolymer (A-13) latex was used instead of the graft copolymer (A-l) latex, and an aqueous calcium chloride solution with the concentration after addition of the latex adjusted to 0.3% by mass was used instead of dilute sulfuric acid with the concentration after addition of the latex adjusted to 0.38% by mass. The volume mean particle diameter of the resulting rubber-like polymer (R-13) was 0.125 pm. The graft ratio of the graft copolymer (A-13) was 44%. The use of an aqueous calcium chloride solution was due to failure of coagulation with dilute sulfuric acid.

[0159] (Production Example 14) Rubber- like Polymer (R-14) and Graft Copolymer (A- 14)A rubber-like polymer (R-14) latex was obtained in the same manner as inProduction Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.3 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 0.2 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A- 14) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-14) latex was used instead of the rubber-like polymer (R-l) latex. Then, a graft copolymer (A-14) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber- like polymer (R-14) was 0.115 pm. The graft ratio of the graft copolymer (A-14) was 39%.

[0160] (Production Example 15) Rubber-like Polymer (R-15) and Graft Copolymer (A-15)A rubber-like polymer (R-15) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.3 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content and 2.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-15) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-15) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A-15) was obtained in the same manner as in Production Example 1. The volume mean particle diameter of the resulting rubber-like polymer (R-15) was 0.14 pm. The graft ratio of the graft copolymer (A-15) was 35%.(Production Example 16) Rubber- like Polymer (R-16) and Graft Copolymer (A- 16)A rubber-like polymer (R-16) latex was obtained in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.3 parts by mass of an aqueous ALSCOAP TH-33OK solution (H-l) based on the solid content and 1.2 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A- 16) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-16) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A- 16) was obtained in the same manner as in Production Example 1 except that the graft copolymer (A- 16) latex was used instead of the graft copolymer (A-l) latex, and an aqueous calcium chloride solution with the concentration after addition of the latex adjusted to 0.3% by mass was used instead of dilute sulfuric acid with the concentration after addition of the latex adjusted to 0.38% by mass. The volume mean particle diameter of the resulting rubber- like polymer (R-16) was 0.1 pm. The graft ratio of the graft copolymer (A- 16) was 37%. The use of an aqueous calcium chloride solution was due to failure of coagulation with dilute sulfuric acid.

[0162] (Production Example 17) Rubber- like Polymer (R-17) and Graft Copolymer (A- 17)A rubber-like polymer (R-17) latex was obtained in the same manner as in Production Example 1 in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content)were changed to 0.3 parts by mass of an aqueous ALSCOAP LS-30 solution (H-2) based on the solid content and 1.2 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A-17) latex was obtained in the same manner as in Production Example 1 except that the rubberlike polymer (R-17) latex was used instead of the rubber-like polymer (R-l) latex. Then, a graft copolymer (A-17) was obtained in the same manner as in Production Example 1 except that the graft copolymer (A-17) latex was used instead of the graft copolymer (A-l) latex, and an aqueous calcium chloride solution with the concentration after addition of the latex adjusted to 0.3% by mass was used instead of dilute sulfuric acid with the concentration after addition of the latex adjusted to 0.38% by mass. The volume mean particle diameter of the resulting rubber-like polymer (R-17) was 0.09 pm. The graft ratio of the graft copolymer (A-17) was 35%. The use of an aqueous calcium chloride solution was due to failure of coagulation with dilute sulfuric acid.

[0163] (Production Example 18) Rubber- like Polymer (R-l 8) and Graft Copolymer (A- 18)A rubber-like polymer (R-l 8) latex was obtained in the same manner as in Production Example 1 in the same manner as in Production Example 1 except that the emulsifiers first added to a reactor (in Production Example 1, 0.2 parts by mass of an aqueous KOHACOOL L-300 solution (E-l) based on the solid content, and 0.7 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content) were changed to 0.3 parts by mass of NEOPELEX G-65 paste (H-3) based on the solid content and 1.2 parts by mass of an aqueous DIPROSIN K-25 solution (F-l) based on the solid content. Thereafter, a graft copolymer (A- 18) latex was obtained in the same manner as in Production Example 1 except that the rubber-like polymer (R-l 8) latex was used instead of the rubber- like polymer (R-l) latex. Then, a graft copolymer (A- 18) was obtained in the same manner as in Production Example 1 exceptthat the graft copolymer (A- 18) latex was used instead of the graft copolymer (A-l) latex, and an aqueous calcium chloride solution with the concentration after addition of the latex adjusted to 0.3% by mass was used instead of dilute sulfuric acid with the concentration after addition of the latex adjusted to 0.38% by mass. The volume mean particle diameter of the resulting rubber-like polymer (R- 18) was 0.08 pm. The graft ratio of the graft copolymer (A- 18) was 33%. The use of an aqueous calcium chloride solution was due to failure of coagulation with dilute sulfuric acid.

[0164] The amounts of the sulfosuccinic acid compound (E), disproportionated rosin (F), and other anionic surfactants added relative to 100 parts by mass of the monomer mixture (r), and the ratio of the amount of the sulfosuccinic acid compound (E) to the amount of the disproportionated rosin (F) based on the mass in the step 1-A; the amount of the anionic surfactant (fatty acid compound (G)) added relative to 100 parts by mass in total of the solid content of the rubber-like polymer (R) latex and the monomer mixture (a) in the step 1-B; and the types of the coagulating agents used in the step 1-C were shown in Tables 1 and 2.

[0165] [Table 1]

[0166] [Table 2]

[0167] (Production Example 19) Vinyl Copolymer (B-l)Production of vinyl copolymer (B-l) was performed using a continuous bulk polymerization apparatus comprising a 2-m3complete mixing polymerization tank having a capacitor for evaporation and dry distillation of monomer vapor and a helical ribbon impeller, a single screw extruder-type preheater, and a twin screw extrudertype monomer remover, according to the following method.

[0168] First, a mixture composed of 72 parts by mass of styrene, 28 parts by mass of acrylonitrile, 0.2 parts by mass of n-octylmercaptan, and 0.015 parts by mass of 1,1- bis(t-butylperoxy)cyclohexane were continuously fed to a complete mixing polymerization tank at 150 kg / h, with the polymerization temperature kept at 130°C and the inner tank pressure at 0.08 MPa, for continuous bulk polymerization. The polymerization rate of the polymerization reaction mixture at the outlet of the complete mixing polymerization tank was controlled to 65+3%.

[0169] Next, the polymerization reaction mixture was preheated by the single screw extruder-type preheater, and then supplied to the twin screw extruder-type monomer remover, with unreacted monomers collected by evaporation under reduced pressure from vent holes of the twin screw extruder-type monomer remover. The collected unreacted monomers were continuously flowed back to the complete mixing polymerization tank. When the apparent polymerization rate of styrene / acrylonitrile copolymer was 99% or more, the copolymer was melt kneaded at 150 kg / h. The melt kneaded product was discharged in strands, cut by a cutter to obtain a vinyl copolymer with a length of 3 mm (B-l) (copolymerization ratio: 72% by mass of a styrene monomer-derived unit to 28% by mass of an acrylonitrile monomer-derived unit). The weight average molecular weight of the resulting vinyl copolymer (B-l) was128,000.

[0170] (Production Example 20) Heat-resistant Vinyl Copolymer (C- 1 )To a 30-L autoclave equipped with a stirrer, 65 parts by mass of styrene, 7 parts by mass of maleic anhydride, 0.3 parts by mass of 2,4-diphenyl-4-methyl-l -pentene, and 25 parts by mass of methyl ethyl ketone were fed. After replacement by nitrogen gas in the system and heating to 92°C, a solution of 28 parts by mass of maleic anhydride and 0.18 parts by mass of t-butylperoxy-2-ethylhexanoate dissolved in 100 parts by mass of methyl ethyl ketone was continuously added for 7 hours. After the addition, 0.03 parts by mass of t-butylperoxy-2-ethylhexanoate was further added, heated to 120°C, and allowed to react for additional 1 hour to obtain a polymer solution of styrene-maleic anhydride copolymer. Then, 32 parts by mass of aniline and 0.6 parts by mass of triethylamine were added to the polymer solution and allowed to react at 140°C for 7 hours. The polymer solution after the imidization reaction was supplied to a vent screw-type extruder, and volatile components were removed to obtain a pellet-shaped heat-resistant vinyl copolymer (C- 1) (copolymerize ratio: 51% by mass of a styrene monomer-derived unit, 48% by mass of an N-phenylmaleimide monomer-derived unit, and 1% by mass of a maleic anhydride monomer-derived unit). The reduced viscosity (r|sp / c) of the resulting heat-resistant vinyl copolymer (C-l) was 0.46 dl / g.

[0171] (Examples 1 to 8 and Comparative Examples 1 to 10)A graft copolymer (A) and vinyl copolymer (B) were mixed at a rate described in Table 3 or 4. In addition, 100 parts by mass of the mixture was mixed with 1.5 parts by mass of carbon black, 1 part by mass of ethylenebis( stearic acid amide), 0.3 parts by mass of bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate, 0.3 parts by mass of phenol, 2-(2H-benzotriazole-2-yl)-4-methyl, and 0.15 parts by mass of octadecyl-3-(3,5-di-tetrabutyl-4-hydroxyphenyl)propionate. The resulting mixture was melt kneaded in a twin screw extruder with a screw diameter of 30 mm with the same rotation direction (temperature range: 240-260°C) to obtain a pellet.

[0172] (Examples 9 and Comparative Examples 11 to 13)A graft copolymer (A), vinyl copolymer (B), and heat-resistant vinyl copolymer (C) were mixed at a rate described in Table 3 or 4. In addition, 100 parts by mass of the mixture was mixed with 1.5 parts by mass of carbon black, 1 part by mass of ethylenebis(stearic acid amide), 0.3 parts by mass of bis(2,2,6,6-tetramethyl- 4-piperidinyl)sebacate, 0.3 parts by mass of phenol, 2-(2H-benzotriazole-2-yl)-4- methyl, and 0.15 parts by mass of octadecyl-3 -(3, 5-di-tetrabutyl-4- hydroxyphenyl)propionate. The resulting mixture was melt kneaded in a twin screw extruder with a screw diameter of 30 mm with the same rotation direction (temperature range: 240-260°C) to obtain a pellet.

[0173] [Table 3]

[0174] [Table 4]

[0175] The resin compositions of Examples 1 to 8 exhibited Charpy impact strength of 7 kJ / m2or more, glossiness of 80% or more, L values of 7.5 or less, and mold fouling properties of B rating or higher, and thus were excellent in impact resistance, surface smoothness, color developability, and appearance of the molded product.

[0176] In comparison, Comparative Example 1, which was not mixed with disproportionated rosin (F) in the step 1-A, exhibited inferior impact resistance and appearance of the molded product; Comparative Example 2, which was not mixed with a sulfosuccinic acid compound (E) in the step 1-A, exhibited inferior surface smoothness and color developability; Comparative Example 3, which was mixed with insufficient amounts of a sulfosuccinic acid compound (E) and disproportionated rosin (F) in the step 1-A, exhibited inferior surface smoothness and color developability; Comparative Example 4, which was mixed with an insufficient amount of a sulfosuccinic acid compound (E) in the step 1-A, exhibited inferior surface smoothness and color developability; Comparative Example 5, which was mixed with an excess amount of a sulfosuccinic acid compound (E) in the step 1-A, exhibited inferior impact resistance and appearance of the molded product; Comparative Example 6, which was mixed with an insufficient amount of disproportionated rosin (F) in the step 1-A, exhibited inferior impact resistance; Comparative Example 7, which was mixed with an excess amount of disproportionated rosin (F), exhibited inferior surface smoothness and color develop ability; Comparative Example 8, which was mixed with an aqueous sodium polyoxyethylene lauryl ether sulfate solution (H-l) as another anionic surfactant instead of with a sulfosuccinic acid compound (E) in the step 1-A, exhibited inferior impact resistance and appearance of the molded product; Comparative Example 9, which was mixed with an aqueous sodium lauryl sulfate solution (H-2) as another anionic surfactant instead of with a sulfosuccinic acid compound (E) in thestep 1-A, exhibited inferior impact resistance and appearance of the molded product; and Comparative Example 10, which was mixed with an aqueous solution of sodium dodecylbenzenesulfonate paste (H-3) as another anionic surfactant instead of with a sulfosuccinic acid compound (E) in the step 1-A, exhibited inferior impact resistance and appearance of the molded product.

[0177] The resin compositions of Example 9 exhibited reduced impact resistance, but can be imparted with heat resistance, and exhibited Charpy impact strength of 5 kJ / m2or more, glossiness of 80% or more, an L value of 7.5 or less, mold fouling properties of B rating or higher, and a heat distortion temperature of 90°C or higher, and thus was excellent in impact resistance, surface smoothness, color developability, appearance of the molded product, and heat resistance.

[0178] In comparison, Comparative Example 11, which was not mixed with disproportionated rosin (F) in the step 1-A, exhibited inferior impact resistance and appearance of the molded product similarly as Comparative Example 1 ; Comparative Example 12, which was not mixed with a sulfosuccinic acid compound (E) in the step 1-A, exhibited inferior surface smoothness and color developability similarly as Comparative Example 2; and Comparative Example 13, which was mixed with an excess amount of disproportionated rosin (F), exhibited inferior surface smoothness and color developability similarly as Comparative Example 7.

[0179] In morphology observation of the resin composition, large particle size rubbers with particle diameters of over 1 pm were observed in Comparative Example 2 as shown in Fig. 1. Similar large particle size rubbers with particle diameters of over 1 pm were also observed in Comparative Examples 3, 4, and 9.Reference Signs List

[0180] 1: large particle size rubber with a particle diameter of over 1 pm

Claims

CLAIMS

1. A method of producing a resin composition, comprising the following steps: step 1 of performing the following steps 1-A to 1-C in this order to obtain a graft copolymer (A): step 1-A of copolymerizing 100 parts by mass of a monomer mixture (r) composed of 97-99.5 parts by mass of an acrylic acid alkyl ester monomer (rl) and 0.5-3 parts by mass of a polyfunctional monomer (r2) in the presence of 0.15-0.45 parts by mass of a sulfosuccinic acid compound (E) represented by the following chemical formula [1] and 1.5-3 parts by mass of disproportionated rosin (F), the sulfosuccinic acid compound (E) and the disproportionated rosin (F) serving as emulsifiers, to obtain a rubber-like polymer (R) latex;[chem 1]wherein,R is a Cs-22 alkyl or alkenyl group;AO is a C2 or C3 oxy alkylene group; n is an integer from 0 to 20;M and N each independently represent hydrogen, an alkali metal, or an alkaline earth metal; p is 1 when M is hydrogen or an alkali metal, or is 1 / 2 when M is an alkaline earth metal; and q is 1 when N is hydrogen or an alkali metal, or is 1 / 2 when N is an alkaline earth metal; step 1-B of graft copolymerizing a monomer mixture (a) comprising atleast an aromatic vinyl monomer (al) and a vinyl cyanide monomer (a2) with the rubber-like polymer (R) in the presence of the rubber-like polymer (R) latex to obtain a graft copolymer (A) latex; and step 1-C of contacting the graft copolymer (A) latex with an acid, which is then neutralized with an alkali, washed with water, and dried to obtain a graft copolymer (A); step 2 of copolymerizing a monomer mixture (b) comprising at least an aromatic vinyl monomer (bl) and a vinyl cyanide monomer (b2) to obtain a vinyl copolymer (B); and step 3 of mixing the graft copolymer (A) obtained in the step 1 and the vinyl copolymer (B) obtained in the step 2, wherein the ratio of the total mass of anionic surfactants contained in the resin composition to the total mass of the resin composition is 5,000 ppm (mass / mass) or less; and wherein the ratio of the total of the sulfosuccinic acid compound (E) represented by the chemical formula [1] and disproportionated rosin (F) contained in the resin composition to the total mass of the resin composition is 2,000 ppm (mass / mass) or less.

2. The method of producing a resin composition of claim 1, further comprising: performing the following step 4 to obtain a heat-resistant vinyl copolymer (C); and mixing the resulting heat-resistant vinyl copolymer (C) with the graft copolymer (A) and the vinyl copolymer (B) in the step 3 to obtain a resin composition: step 4 of copolymerizing a monomer mixture (c) comprising at least an aromatic vinyl monomer (cl) and a maleimide monomer (c2) to obtain a heat-resistant vinyl copolymer (C);

3. The method of producing a resin composition of claim 1 or 2, wherein the sulfosuccinic acid compound (E) and disproportionated rosin (F) are used in the step 1-A in a mass ratio of 9:91 to 30:70 (sulfosuccinic acid compound (E): disproportionated rosin (F)).

4. A resin composition, comprising: a graft copolymer (A) obtained by graft copolymerization of a monomer mixture (a) comprising at least an aromatic vinyl monomer (al) and a vinyl cyanide monomer (a2) in the presence of an acrylic rubber-like polymer (R) obtained by copolymerization of an acrylic acid alkyl ester monomer (rl) and a polyfunctional monomer (r2); and a vinyl copolymer (B) obtained by copolymerization of a monomer mixture (b) comprising at least an aromatic vinyl monomer (bl) and a vinyl cyanide monomer (b2), wherein the ratio of the total mass of anionic surfactants contained in the resin composition to the total mass of the resin composition is 5,000 ppm (mass / mass) or less; and wherein the ratio of the total of a sulfosuccinic acid compound (E) represented by the following chemical formula [1] and disproportionated rosin (F) contained in the resin composition to the total mass of the resin composition is 2,000 ppm (mass / mass) or less; and wherein the mass ratio of the sulfosuccinic acid compound (E) to the disproportionated rosin (F) is 10:90 to 30:70 (sulfosuccinic acid compound (E): disproportionated rosin (F)): [chem 2]wherein,R is a Cs-22 alkyl or alkenyl group;AO is a C2 or C3 oxy alkylene group; n is an integer from 0 to 20;M and N each independently represent hydrogen, an alkali metal, or an alkaline earth metal; p is 1 when M is hydrogen or an alkali metal, or is 1 / 2 when M is an alkaline earth metal; and q is 1 when N is hydrogen or an alkali metal, or is 1 / 2 when N is an alkaline earth metal.

5. The resin composition of claim 4, further comprising a heat-resistant vinyl copolymer (C) obtained by copolymerizing a monomer mixture (c) comprising at least an aromatic vinyl monomer (cl) and a maleimide monomer (c2).

6. A molded product obtained by molding a resin composition obtained by the method of producing a resin composition of any one of claims 1 to 3, or by molding the resin composition of claim 4 or 5.

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