JP2016204591A - Thermoplastic resin composition and molded article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition capable of providing a molded article high in flowability, excellent in shock resistance and coating film smoothness and having suppressed delamination or arising phenomenon.SOLUTION: There is provided a thermoplastic resin composition containing a rubber reinforced styrenic resin (A), a polycarbonate resin (B), a graft copolymer (C) having a copolymer segment (I) consisting of an α-olefin monomer and an acrylic acid alkyl ester monomer and a vinyl polymer segment (II) consisting of a vinyl monomer and an ethylene/(meth)acrylic acid ester/carbon monoxide copolymer (D), with the graft copolymer (C) of 1 to 10 pts.mass and the ethylene/(meth)acrylic acid ester/carbon monoxide copolymer (D) of 0.05 to 1 pts.mass based on total 100 pts.mass of the rubber reinforced styrenic resin (A) and the polycarbonate resin (B).SELECTED DRAWING: None

Description

  The present invention relates to a rubber-reinforced styrene resin (A), a polycarbonate resin (B), a graft copolymer (C), and an ethylene / (meth) acrylic acid ester / carbon monoxide copolymer (D). The present invention relates to a thermoplastic resin composition to be contained.

  Polycarbonate resin / rubber reinforced styrene resin alloy is low cost by using rubber reinforced styrene resin represented by acrylonitrile-butadiene-styrene (ABS) resin together with polycarbonate resin with excellent heat resistance and impact resistance. Since it can achieve improvement in molding processability and thickness dependency in impact resistance, it is used as a molding material for various components in a wide range of fields such as the vehicle field, the home appliance field, and the building material field. For example, in recent years, in the field of vehicles, development has been made for four-wheel interior members and the like for the purpose of heat resistance and countermeasures against sharp edges at the time of material destruction.

  On the other hand, as a demand of the market, there is a strong demand for reduction of coating defects (paint resistance) of molded products. Polycarbonate resin / rubber reinforced styrene resin alloy is a material that is easy to paint because it contains rubber reinforced styrene resin, but it is affected by factors such as resin composition characteristics, molding conditions, coating method, and coating environment. May cause poor painting. Among these poor coatings, a suction phenomenon that occurs when solvent components such as thinner contained in the paint act on the molded product (a phenomenon in which fine irregularities are formed on the coating surface and uneven gloss is observed due to irregular reflection of light. ) And the edge phenomenon (a phenomenon in which small holes in the form of craters are formed on the paint surface) that are particularly common at the edge of injection-molded products are cited as typical painting defects, and the product value of the final product It is a big loss.

  To date, technologies for improving the surface appearance of polycarbonate resin / rubber reinforced styrene resin alloys include, for example, ABS resins, polycarbonate resins, epoxy group-containing olefin polymer segments and vinyl polymer segments. A heat resistant ABS resin composition (for example, see Patent Document 1) in which a structural graft copolymer is blended has been proposed. However, such a resin composition has a problem of low fluidity because the multiphase structure graft copolymer reacts with polycarbonate.

  On the other hand, as a technique for improving the fluidity and paintability of the rubber-reinforced styrene resin composition, for example, styrene containing a styrene polymer, an ethylene / unsaturated ester / carbon monoxide copolymer and a graft copolymer System polymer composition (for example, refer to Patent Document 2), a rubber-reinforced resin, an ethylene / (meth) acrylic acid ester / carbon monoxide copolymer, and a composition containing polytetrafluoroethylene (for example, Patent Document 3), graft copolymer, heat-resistant vinyl copolymer, highly cyanidated vinyl copolymer, vinyl copolymer, and ethylene / (meth) acrylate / carbon monoxide copolymer. A heat-resistant and paint-resistant thermoplastic resin composition (for example, see Patent Document 4) has been proposed. However, the resin compositions described in Patent Documents 2 to 4 have a problem that the impact resistance is insufficient. In addition, the thermoplastic resin compositions described in Patent Documents 3 and 4 improve the coating defects such as the suction phenomenon and the crack phenomenon, but even if these techniques are applied to the polycarbonate resin / rubber reinforced styrene resin alloy. However, there was a problem that the armpit phenomenon was not solved and the fluidity and impact resistance were lowered.

JP 7-18153 A Japanese Patent Laid-Open No. 11-12415 JP 2008-56904 A JP 2012-36384 A

  Further, as a result of the study by the present inventors, in the resin compositions described in Patent Documents 2 to 4, ethylene / (meth) acrylate / carbon monoxide with respect to the polycarbonate resin / rubber reinforced styrene resin alloy composition. When a specific amount or more of the copolymer is blended, a problem that a problem of delamination occurs when the gate portion of the injection molded product is cut has been clarified. In addition, in the resin composition described in Patent Document 2, when a specific amount or more of the graft copolymer is blended with the polycarbonate resin / rubber reinforced styrene resin alloy composition, the coating film smoothness decreases when the molded product is coated. The issues to be solved became clear. Then, this invention makes it a subject to provide the thermoplastic resin composition which can obtain the molded article which was excellent in fluidity | liquidity, was excellent in impact resistance and coating-film smoothness, and was suppressed in the delamination and the cracking phenomenon. .

The present invention mainly has the following configurations (1) to (4).
(1) Copolymer segment (I) comprising a rubber-reinforced styrene resin (A), a polycarbonate resin (B), an α-olefin monomer and an alkyl acrylate monomer, and a vinyl monomer A thermoplastic resin composition comprising a graft copolymer (C) having a vinyl polymer segment (II) and an ethylene / (meth) acrylate / carbon monoxide copolymer (D). , 1 to 10 parts by mass of the graft copolymer (C) and the ethylene / (meth) acrylate ester / 100 parts by mass of the rubber-reinforced styrene resin (A) and the polycarbonate resin (B). A thermoplastic resin composition containing 0.05 to 1 part by mass of a carbon monoxide copolymer (D).
(2) The copolymer segment (I) composed of the α-olefin monomer and the alkyl acrylate monomer is a copolymer segment composed of ethylene and ethyl acrylate, and is composed of the vinyl monomer. The thermoplastic resin composition according to (1), wherein the vinyl polymer segment (II) is a copolymer segment composed of acrylonitrile and styrene.
(3) 20 to 70 parts by mass of rubber-reinforced styrene resin (A) and polycarbonate resin (B) with respect to 100 parts by mass in total of the rubber-reinforced styrene resin (A) and polycarbonate resin (B). The thermoplastic resin composition according to (1) or (2), containing 30 to 80 parts by mass.
(4) A molded article obtained by injection molding the thermoplastic resin composition according to any one of (1) to (3).

  The thermoplastic resin composition of the present invention is excellent in fluidity. According to the thermoplastic resin composition of the present invention, it is possible to obtain a molded article that is excellent in impact resistance and coating film smoothness, and in which delamination and cracking phenomenon are suppressed. It can cope with complexity.

  Hereinafter, the thermoplastic resin composition of the present invention will be specifically described. In the present invention, “(meth) acryl” means acryl or methacryl.

  The thermoplastic resin composition of the present invention comprises a rubber-reinforced styrene resin (A), a polycarbonate resin (B), a copolymer segment (I) comprising an α-olefin monomer and an acrylic acid alkyl ester monomer. ) And a graft copolymer (C) having a vinyl polymer segment (II) comprising a vinyl monomer (hereinafter sometimes referred to as “graft copolymer (C)”), ethylene / (Meth) acrylic acid ester / carbon monoxide copolymer (D) is contained. By containing the rubber-reinforced styrene resin (A), the fluidity of the thermoplastic resin composition can be improved, and by containing the polycarbonate resin (B), the impact resistance of the molded product is improved. be able to. In the thermoplastic resin composition containing the rubber-reinforced styrene resin (A) and the polycarbonate resin (B), the graft copolymer (C) and the ethylene / (meth) acrylate / carbon monoxide copolymer are further added. By containing a specific amount of the coalescence (D), the coating film smoothness of the molded product can be improved, and delamination and cracking can be suppressed. Hereinafter, each component will be described.

  The rubber-reinforced styrene resin (A) contains at least an aromatic vinyl monomer (a2) and a vinyl cyanide monomer (a3) in the presence of the diene rubber polymer (a1). Contains a diene graft copolymer (A1) obtained by graft copolymerization of a vinyl monomer mixture, and at least an aromatic vinyl monomer (a2) and a vinyl cyanide monomer (a3). Those containing a vinyl copolymer (A2) obtained by copolymerizing a vinyl monomer mixture are preferred.

  Examples of the diene rubber polymer (a1) include polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, styrene-butadiene block copolymer, and butyl acrylate-butadiene copolymer. It is done. Two or more of these may be used. Of these, polybutadiene is preferably used.

  The diene rubbery polymer (a1) preferably has a glass transition temperature of 0 ° C. or lower, and can further improve the impact resistance of the molded product. On the other hand, the lower limit of the glass transition temperature is practically about −80 ° C. The glass transition temperature of the diene rubbery polymer (a1) can be determined by DSC (differential scanning calorimetry).

  The diene rubbery polymer (a1) is generally used as a latex dispersed in water with an emulsifier. The particle size distribution of the diene rubbery polymer (a1) in the present invention is not particularly limited, but from the viewpoint of further improving impact resistance, the weight-based particle size frequency distribution has a range of at least 200 to 400 nm. It is preferable to have a maximum value in each range of 450 nm or more. Particles having a particle diameter of 200 to 400 nm can further improve the fluidity of the thermoplastic resin composition. From the viewpoint of further improving the impact resistance of the molded article by taking advantage of the properties of the diene rubber polymer (a1), 300 to 400 nm is more preferable. Moreover, the impact resistance of the molded product can be further improved by particles having a particle diameter of 450 nm or more. 600 nm or more is more preferable. On the other hand, 1200 nm or less is more preferable from the viewpoint of further improving the fluidity of the thermoplastic resin composition. In the present invention, by using the diene rubbery polymer (a1) having a particle size frequency distribution having a maximum value in both of these numerical ranges, the fluidity of the thermoplastic resin composition is maintained, while maintaining the fluidity of the molded product. Impact resistance can be further improved.

  The diene rubbery polymer (a1) having such a particle size frequency distribution includes, for example, a diene rubbery polymer having a weight average particle size of 200 to 400 nm and a diene rubber having a weight average particle size of 450 nm or more. It can be obtained by blending with a polymer. From the viewpoint of improving the fluidity of the thermoplastic resin composition, the blending ratio of the diene rubber polymer having a weight average particle diameter of 200 to 400 nm and the diene rubber polymer having a weight average particle diameter of 450 nm or more. (200 to 400 nm / 450 nm or more) is preferably 9/1 (weight ratio) or less. On the other hand, from the viewpoint of further improving the impact resistance of the molded product, the blending ratio (200 to 400 nm / 450 nm or more) is preferably 5/5 or more, and more preferably 6/4 or more.

  Here, the weight-based particle size frequency distribution and the weight average particle size of the diene rubber polymer (a1) in the present invention are 300 to 500 times that of the latex of the diene rubber polymer (a1) in pure water. And can be measured by a particle size distribution measuring apparatus using a laser diffraction / scattering method.

  The mass fraction of the diene rubber polymer (a1) in the raw material constituting the diene graft copolymer (A1) is 100% by mass in total of the diene rubber polymer (a1) and the vinyl monomer mixture. Among them, 40 to 65% by mass is preferable. When the mass fraction of the diene rubbery polymer (a1) is 40% by mass or more, the impact resistance of the molded product can be further improved. 43 mass% or more is more preferable. On the other hand, if the mass fraction of the diene rubber polymer (a1) is 65% by mass or less, the fluidity of the thermoplastic resin composition can be further improved and the cracking phenomenon of the molded product can be further suppressed. 60 mass% or less is more preferable, and 55 mass% or less is further more preferable.

  The vinyl monomer mixture used as a raw material for the diene graft copolymer (A1) contains an aromatic vinyl monomer (a2) and a vinyl cyanide monomer (a3). Furthermore, you may contain the other copolymerizable vinyl monomer to such an extent that the effect of this invention is not lost.

  Examples of the aromatic vinyl monomer (a2) include styrene, α-methylstyrene, vinyltoluene, o-ethylstyrene, p-methylstyrene, chlorostyrene, and bromostyrene. Two or more of these may be used. Of these, styrene is preferably used.

  Examples of the vinyl cyanide monomer (a3) include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like. Two or more of these may be used. Of these, acrylonitrile is preferably used.

  Examples of other copolymerizable monomers include N-phenylmaleimide, N-methylmaleimide, and methyl methacrylate, and can be selected according to the respective purposes. Two or more of these may be used. In order to improve heat resistance and flame retardancy, N-phenylmaleimide is preferred. Further, methyl methacrylate is preferably used in order to improve hardness and transparency.

  The mass fraction of the vinyl monomer mixture in the raw material constituting the diene graft copolymer (A1) is 35% of the total 100 mass% of the diene rubber polymer (a1) and the vinyl monomer mixture. -60 mass%. If the mass fraction of the vinyl monomer mixture is 35% by weight or more, the fluidity of the thermoplastic resin composition can be further improved, and the cracking phenomenon of the molded product can be further suppressed. 40 mass% or more is more preferable, and 45 mass% or more is further more preferable. On the other hand, if the mass fraction of the vinyl monomer mixture is 60% by mass or less, the impact resistance of the molded product can be further improved. 57 mass% or less is preferable.

  The mass fraction of the aromatic vinyl monomer (a2) and the vinyl cyanide monomer (a3) in the raw material constituting the diene graft copolymer (A1) is determined by the flow of the thermoplastic resin composition. From the viewpoint of further improving the properties, the aromatic vinyl monomer (a2) is preferably 35 to 45% by mass and the vinyl cyanide monomer (a3) is 10 to 20% by mass.

The graft ratio of the diene-based graft copolymer (A1) is not particularly limited, but is preferably 10 to 100% by mass, particularly preferably 20 to 70% by mass, from the viewpoint of improving mechanical strength. . Here, the graft ratio is a value calculated by the following equation.
Graft rate (mass%) = [<amount of vinyl copolymer grafted onto diene copolymer (mass)> / <amount of diene copolymer of graft copolymer (mass)>] × 100.

  The vinyl copolymer (A2) is obtained by copolymerizing a vinyl monomer mixture containing at least an aromatic vinyl monomer (a2) and a vinyl cyanide monomer (a3). It is. Furthermore, the vinyl monomer mixture may contain other copolymerizable monomers to such an extent that the effects of the present invention are not lost.

  Examples of the aromatic vinyl monomer (a2) include those exemplified as the aromatic vinyl monomer (a2) in the diene graft copolymer (A1) described above, and styrene is preferably used.

  Examples of the vinyl cyanide monomer (a3) include those exemplified as the vinyl cyanide monomer (a3) in the diene graft copolymer (A1) described above, and acrylonitrile is preferably used.

  Examples of the other copolymerizable monomer include those exemplified as the other copolymerizable monomer in the diene-based graft copolymer (A1), and methyl methacrylate is preferably used.

  The mass fraction of the aromatic vinyl monomer (a2) in the raw material constituting the vinyl copolymer (A2) is preferably 60% by mass or more in a total of 100% by mass of the vinyl monomer mixture. If the mass fraction of the aromatic vinyl monomer (a2) is 60% by mass or more, the fluidity of the thermoplastic resin composition can be further improved. 70 mass% or more is more preferable. Further, the mass fraction of the vinyl cyanide monomer (a3) is preferably 18% by mass or more. If the mass fraction of the vinyl cyanide monomer (a3) is 18% by mass or more, the chemical resistance of the molded product can be improved and the cracking phenomenon can be further suppressed. 19 mass% or more is more preferable, and 20 mass% or more is further more preferable.

  The intrinsic viscosity of the vinyl copolymer (A2) at 30 ° C. is preferably 0.3 to 0.8 dl / g. When the intrinsic viscosity at 30 ° C. is 0.3 dl / g or more, the impact resistance of the molded product can be further improved. On the other hand, the fluidity | liquidity of a thermoplastic resin composition can be improved more as intrinsic viscosity in 30 degreeC is 0.7 dl / g or less. Here, the intrinsic viscosity of the vinyl copolymer (A2) at 30 ° C. is determined using each of the solutions having a concentration of 0.2 g / dl and 0.4 g / dl obtained by dissolving the vinyl copolymer (A2) in methyl ethyl ketone. The viscosity can be calculated from the viscosity measured with an Ubbelohde viscometer at 30 ° C.

  The ratio of the diene graft copolymer (A1) and the vinyl copolymer (A2) contained in the rubber-reinforced styrene resin (A) is not particularly limited, and can be contained in any ratio.

  There are no particular limitations on the method for producing the graft copolymer (A1) and the vinyl copolymer (A2), and examples thereof include bulk polymerization, suspension polymerization, bulk suspension polymerization, solution polymerization, emulsion polymerization, and precipitation polymerization. A method is mentioned. Two or more of these may be combined. There is no particular restriction on the method of charging the monomer, and it may be added all at once in the initial stage, or in order to add or prevent the composition distribution of the copolymer, and add in several steps step by step. Polymerization may be performed.

  By the above method, the monomer mixture containing the aromatic vinyl monomer (a2) and the vinyl cyanide monomer (a3) is graft copolymerized with the diene rubber polymer (a1). However, all of the monomer mixture may not be graft copolymerized with the diene rubber polymer (a1). Therefore, the diene graft copolymer (A1) in the present invention is composed of the aromatic vinyl monomer (a2) and the vinyl cyanide monomer, which are not graft copolymerized with the diene rubber polymer (a1). The copolymer which consists of a monomer mixture containing a body (a3) may be included.

  In the polymerization of the diene graft copolymer (A1) and the vinyl copolymer (A2), an initiator is preferably added. As the initiator, a peroxide or an azo compound is preferably used.

  Specific examples of the peroxide include, for example, benzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, t-butyl cumyl peroxide, and t-butyl peroxide. Acetate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxide, t-butyl peroctate, 1,1-bis (t-butylperoxy) 3, 3, 5 -Trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, t-butylperoxy-2-ethylhexanoate and the like. Two or more of these may be used. Of these, cumene hydroperoxide and 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane are preferably used.

  Specific examples of the azo compound include, for example, azobisisobutyronitrile, azobis (2,4dimethylvaleronitrile), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2-cyano-2- Propyl azoformamide, 1,1'-azobiscyclohexane-1-carbonitrile, azobis (4-methoxy-2,4-dimethylvaleronitrile), dimethyl 2,2'-azobisisobutyrate, 1-t-butylazo Examples include -1-cyanocyclohexane, 2-t-butylazo-2-cyanobutane, 2-t-butylazo-2-cyano-4-methoxy-4-methylpentane, and the like. Two or more of these may be used. Of these, azobisisobutyronitrile is preferably used.

  In the polymerization of the diene graft copolymer (A1) and the vinyl copolymer (A2), a chain transfer agent such as mercaptan or terpene may be added for the purpose of adjusting the degree of polymerization. Examples of the chain transfer agent include n-octyl mercaptan, t-dodecyl mercaptan, n-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, terpinolene and the like. Two or more of these may be used. Of these, n-octyl mercaptan, t-dodecyl mercaptan, and n-dodecyl mercaptan are preferably used.

  The content of the rubber-reinforced styrene resin (A) in the thermoplastic resin composition of the present invention is 20 to 70 mass with respect to 100 parts by mass in total of the rubber-reinforced styrene resin (A) and the polycarbonate resin (B). Part is preferred. By setting the content of the rubber-reinforced styrene resin (A) to 20 parts by mass or more, the fluidity of the thermoplastic resin composition can be further improved. 30 parts by mass or more is preferable, and 35 parts by mass or more is more preferable. On the other hand, by setting the content of the rubber-reinforced styrene resin (A) to 70 parts by mass or less, the impact resistance of the molded product can be further improved. 60 mass parts or less are preferable.

  The polycarbonate resin (B) is obtained by reacting an aromatic dihydroxy compound such as 4,4'-dihydroxydiphenyl-2,2'-propane (commonly called bisphenol) and a carbonate precursor such as phosgene. For example, as a method for producing a polycarbonate using 4,4′-dihydroxydiphenyl-2,2′-propane, 4,4′-dihydroxydiphenyl-2,2′-propane is added in the presence of a caustic aqueous solution and a solvent. Examples thereof include a method of blowing phosgene and a method of transesterifying 4,4′-dihydroxydiphenyl-2,2′-propane and a carbonic acid diester in the presence of a catalyst.

The melt volume rate of the polycarbonate resin (B) used in the present invention is not particularly limited, but the melt volume rate measured under the conditions of a temperature of 300 ° C. and a load of 1.2 kg in accordance with ISO 1133 is 8 to it is preferably in the range of 13cm ^3/10 minutes.

  The content of the polycarbonate resin (B) in the thermoplastic resin composition of the present invention is 30 to 80 parts by mass with respect to a total of 100 parts by mass of the rubber-reinforced styrene resin (A) and the polycarbonate resin (B). preferable. By setting the content of the polycarbonate resin (B) to 30 parts by mass or more, the impact resistance of the molded product can be further improved. 40 parts by mass or more is preferable. On the other hand, fluidity | liquidity can be improved more by making content of a polycarbonate-type resin (B) 80 mass parts or less. 70 mass parts or less are preferable, and 65 mass parts or less are more preferable.

  In the present invention, the graft copolymer (C) has a copolymer segment (I) and a vinyl polymer segment (II).

  The copolymer segment (I) is a copolymer segment composed of an α-olefin monomer and an acrylic acid alkyl ester monomer. Here, the α-olefin monomer refers to an alkene having a carbon-carbon double bond at the molecular end, and examples thereof include methylene, ethylene, 1-propylene, and 1-butylene. Moreover, the acrylic acid alkyl ester monomer refers to a carboxylic acid ester of acrylic acid and a primary alcohol, and examples thereof include ethyl acrylate, n-propyl acrylate, and n-butyl acrylate. Specific examples of the copolymer segment (I) include a segment composed of an ethylene-ethyl acrylate copolymer, a segment composed of an ethylene-n-butyl acrylate copolymer, and a segment composed of a propylene-ethyl acrylate copolymer. And a segment made of a propylene-n-butyl acrylate copolymer. You may contain 2 or more types of these segments. Among these, a segment made of an ethylene-ethyl acrylate copolymer is preferable. In the present invention, the α-olefin monomer and the acrylic acid alkyl ester monomer have no other functional group such as an epoxy group, and the copolymer segment (I) has an α-olefin. It does not include segments obtained by copolymerizing monomers other than monomers and acrylic acid alkyl ester monomers.

  The vinyl polymer segment (II) is a polymer segment composed of a vinyl monomer, and a segment composed of a polymer harder than the copolymer segment (I) is preferable. For example, a segment made of polystyrene, a segment made of polymethyl methacrylate, a segment made of a styrene-acrylonitrile copolymer, and the like can be mentioned. Two or more of these may be contained. Among these, from the viewpoint of further improving the impact resistance of the molded product, a segment made of a styrene-acrylonitrile copolymer is preferable. In the present invention, the vinyl monomer has no functional group such as an epoxy group, and the vinyl polymer segment (II) is copolymerized with a monomer other than the vinyl monomer. Segment is not included.

  The mass fraction of the copolymer segment (I) and the vinyl polymer segment (II) in the graft copolymer (C) is 100% by mass in total of the copolymer segment (I) and the polymer segment (II). On the other hand, 20-90 mass% of copolymer segments (I) and 10-80 mass% of vinyl polymer segments (II) are preferable. By containing the copolymer segment (I) in an amount of 20% by mass or more and the vinyl polymer segment (II) in an amount of 80% by mass or less, it is possible to further suppress the phenomenon of the molded product. More preferably, the copolymer segment (I) is contained in an amount of 60% by mass or more and the vinyl polymer segment (II) is contained in an amount of 40% by mass or less. On the other hand, by containing 90% by mass or less of the copolymer segment (I) and 10% by mass or more of the vinyl polymer segment (II), it is possible to further suppress delamination of the molded product.

  In the graft copolymer (C), it is preferable that the vinyl polymer segment (II) is grafted to the copolymer segment, and the cracking phenomenon of the molded product can be further suppressed. However, all of the vinyl polymer segment (II) may not be grafted to the copolymer segment (I), and a part thereof may be free.

  Examples of the method for producing a graft copolymer include a radical polymerization initiator represented by benzoyl peroxide and t-butyl in an α-olefin / acrylic acid alkyl ester copolymer constituting the copolymer segment (I). Illustrates a method of impregnating a radically polymerizable organic peroxide such as peroxyacryloyloxyethyl carbonate and a vinyl monomer, polymerizing the vinyl monomer, and then performing graft copolymerization under melting conditions. be able to.

  The content of the graft copolymer (C) in the thermoplastic resin composition of the present invention is 1 to 10 parts by mass with respect to a total of 100 parts by mass of the rubber-reinforced styrene resin (A) and the polycarbonate resin (B). It is. When the content of the graft copolymer (C) is less than 1 part by mass, coating of the molded product tends to occur. 2 parts by mass or more is preferable. On the other hand, when the content of the graft copolymer (C) exceeds 10 parts by mass, the coating film smoothness of the molded article is lowered. 5 parts by mass or less is preferable.

  In the present invention, the ethylene / (meth) acrylic acid ester / carbon monoxide copolymer (D) is a copolymer obtained by copolymerizing at least ethylene, (meth) acrylic acid ester and carbon monoxide. A random copolymer or a block copolymer may be used, but a random copolymer is preferable. You may copolymerize the other monomer copolymerizable with these.

  As (meth) acrylic acid ester, (meth) acrylic acid and C1-C8 alcohol ester are preferable, for example, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid n. -Propyl, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic acid 2 -Ethylhexyl, octyl (meth) acrylate, etc. are mentioned. Two or more of these may be used. Among these, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, (meth) acrylic acid t-Butyl and isobutyl (meth) acrylate are preferred.

  The copolymerization ratio of ethylene / (meth) acrylic acid ester / carbon monoxide copolymer (D) is 10 to 85% by mass of ethylene, 10 to 50% by mass of (meth) acrylic acid ester, and 5 to 40% by mass of carbon monoxide. %, Ethylene 40-80 mass%, (meth) acrylic acid ester 15-40 mass%, and carbon monoxide 5-20 mass% are more preferable.

  The content of ethylene / (meth) acrylic ester / carbon monoxide copolymer (D) in the thermoplastic resin composition of the present invention is a total of 100 of the rubber-reinforced styrene resin (A) and the polycarbonate resin (B). It is 0.05-1 mass part with respect to a mass part. If the content of the ethylene / (meth) acrylic acid ester / carbon monoxide copolymer (D) is less than 0.1 parts by mass, the cracking phenomenon of the molded product tends to occur. 0.5 parts by mass or more is preferable. On the other hand, when the content of the ethylene / (meth) acrylic acid ester / carbon monoxide copolymer (D) exceeds 1 part by mass, delamination of the molded product tends to occur.

  The thermoplastic resin composition of the present invention may further contain an acidic compound as long as the characteristics of the present invention are not impaired. In the thermoplastic resin composition of the present invention, the diene graft copolymer (A1) may exhibit weak alkalinity, but by containing an acidic compound, alkali decomposition or thermal decomposition of the polycarbonate resin (B) can be achieved. Can be suppressed. The acidic compound may be added when the diene graft copolymer (A1) is produced, or may be added when each component is melt-kneaded when producing the thermoplastic resin composition of the present invention.

  The acidic compound is not particularly limited. For example, hydrochloric acid, sulfuric acid, nitric acid, acetic acid, oxalic acid, malonic acid, succinic acid, maleic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic anhydride, succinic anhydride Itaconic acid, benzoic acid, methyl benzoate, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, diphenic acid, phosphoric acid, sodium dihydrogen phosphate and the like. Two or more of these may be contained. Among these, maleic anhydride, succinic anhydride, phosphoric acid, and sodium dihydrogen phosphate are preferable, and maleic anhydride and phosphoric acid are more preferable.

  The thermoplastic resin composition of the present invention may contain a resin other than the above (A) to (D) as long as the characteristics of the present invention are not impaired. Examples of the resins other than (A) to (D) include polyethylene terephthalate, polypropylene terephthalate, polycyclohexylenedimethyleneethylene terephthalate, polyarylate, liquid crystal polyester, polyester such as polylactic acid, polycaprolactone, nylon 6, and nylon 6. , 6, nylon 6,10, nylon 4,6, nylon 6T, nylon 9T, nylon 11 and other polyamides, polyphenylene sulfide, polyacetal, crystalline styrene, polyphenylene ether, and the like. Two or more of these may be contained.

  If necessary, the thermoplastic resin composition of the present invention includes a hindered phenol-based antioxidant, a sulfur-containing compound-based antioxidant, a phosphorus-containing organic compound-based antioxidant, a phenol-based, an acrylate-based thermal oxidation, or the like. Inhibitors, UV absorbers such as benzotriazole, benzophenone, and succinate, decabromobiphenyl ether, tetrabromobisphenol A, chlorinated polyethylene, brominated epoxy oligomer, brominated polycarbonate, antimony trioxide, condensed phosphate, etc. Flame retardants and flame retardant aids, antibacterial agents such as silver antibacterial agents, antifungal agents, carbon black, titanium oxide, mold release agents, lubricants, pigments and dyes.

  The thermoplastic resin composition of the present invention can be obtained, for example, by melt-kneading the constituent components. The melt kneading method is not particularly limited, and examples thereof include a melt kneading method using a monoaxial or biaxial screw in a cylinder having a heating device and a vent. When a biaxial screw is used, the screw may be in the same rotational direction or in a different rotational direction. The heating temperature at the time of melt kneading is usually selected from the range of 210 to 320 ° C. It is also possible to freely set a temperature gradient or the like within a range that does not impair the object of the present invention.

  The thermoplastic resin composition of the present invention can be molded by any molding method. The molding method is not particularly limited, but injection molding is preferable. The injection molding temperature is generally 240 to 300 ° C. The mold temperature at the time of injection molding is generally 30 to 80 ° C.

  The thermoplastic resin composition of the present invention can provide a molded article having excellent fluidity and excellent impact resistance. Moreover, delamination at the time of cutting the gate portion can be suppressed, and coating defects such as suction and cracking can be suppressed even when an injection molded product having an edge of less than 90 ° is applied. Furthermore, it is possible to obtain a molded article having good smoothness of the coating film. For this reason, the thermoplastic resin composition and molded product of the present invention can reduce fluidity, impact resistance, paint resistance, coating film smoothness, and peeling defects, such as automotive interior center clusters, meter clusters, and ventilator cases. It can be suitably used for required applications.

  In order to describe the present invention more specifically, examples are given below, but these examples do not limit the present invention in any way. First, evaluation methods in each reference example, example, and comparative example are described below.

(1) Graft rate 200 ml of acetone was added to a predetermined amount (m; about 1 g) of the diene-based graft copolymer (A1) obtained in Reference Example 1, and the mixture was refluxed in a hot water bath at a temperature of 70 ° C. for 3 hours. This solution was added to 8800 r. p. m. After centrifuging at (10000 G) for 40 minutes, the insoluble matter was filtered. The obtained acetone insoluble matter was dried under reduced pressure at 60 ° C. for 5 hours, and its mass (n) was measured. The graft ratio was calculated from the following formula. Here, L is the rubber content of the graft copolymer.
Graft ratio (mass%) = {[(n) − {(m) × L}] / [(m) × L]} × 100.

(2) Intrinsic viscosity Using a solution of the vinyl copolymer (A2) obtained in Reference Example 1 dissolved in methyl ethyl ketone at a concentration of 0.2 g / dl and 0.4 g / dl at a measurement temperature of 30 ° C., an Ubbelohde The intrinsic viscosity was calculated by measuring the viscosity with a viscometer.

(3) Fluidity For the pellets obtained in each Example and Comparative Example, the melt flow rate was measured at a temperature of 240 ° C. and a 98N load condition in accordance with ISO1133.

(4) Impact resistance Multi-purpose test piece defined in JISK 7139 from pellets obtained in each Example and Comparative Example using an injection molding machine in which the cylinder temperature is set to 250 ° C. and the mold temperature is set to 60 ° C. Type A1 was molded, and Charpy impact strength was measured according to ISO 179 / 1eA using a type B2 test piece cut out.

(5) Laminar peeling From the pellets obtained in each Example and Comparative Example, a molded article having a tunnel gate was injection molded using an injection molding machine in which the cylinder temperature was set to 250 ° C and the mold temperature set to 60 ° C. . The cut surface of the gate part that was automatically cut was visually observed, and the degree of peeling was evaluated in three stages according to the following criteria, and three or more were regarded as acceptable.
3: It is a level which does not stand out even if peeling has generate | occur | produced in the cut surface or there is peeling.
2: Partial peeling occurred on the cut surface.
1: Peeling occurred over a wide area of the cut surface.

  The gate is the narrowest part of the resin flow path just before the cavity of the injection mold, and the part that separates the molded product from the runner. The tunnel gate is the gate part when the mold is opened and closed. It refers to a molded product having a shape that is automatically separated from the runner.

(6) Painted edge of molded product with edge From the pellets obtained in each example and comparative example, using an injection molding machine in which the cylinder temperature was set to 250 ° C. and the mold temperature set to 60 ° C., the edge portion in the longitudinal direction A 70 mm × 240 mm × 2 mm thick square plate having There are two types of edge angles θ, 45 ° and 60 °. Acrylic-urethane two-component paint (Letane PG60 / Hardener, manufactured by Kansai Paint Co., Ltd.) is applied to the square plate, and a coating robot: KE610H manufactured by Kawasaki Heavy Industries, Ltd. After coating, the coating was dried at a drying temperature of 80 ° C. for 30 minutes to obtain a coated molded product. About the obtained coating molded product, both edge parts were observed, and the presence or absence of the coating tool was evaluated according to the following criteria. ◎ and ○ were acceptable levels, and △ and x were unacceptable levels.
A: There is no occurrence of cracks at both edges, and the appearance is good.
◯: There is no occurrence of cracks at the 45 ° edge, and there is cracking at the 60 ° edge, but this is a level that does not cause a problem.
Δ: Wrinkles are conspicuous at both edges, and the appearance is problematic.
X: Waki occurred on both edges.

(7) Coating smoothness (web scan)
By measuring the W1 value and the W4 value using the microwave scan T (Toyo Seiki Seisakusho Co., Ltd.) for the 50 mm × 150 mm flat portion of the coated molded product obtained by the method described in (6) above, The smoothness of the surface of the coated molded product was evaluated. The W1 value is an index for evaluating the waviness of the coating film, and the W4 value is an index for evaluating the glossiness of the coating film. Measurement was performed on three painted molded articles, and the number average value was calculated. It shows that the smoothness of a coating film is so favorable that each value is low. W1: <25 mm and W4: <20 mm were acceptable levels.

Reference Example 1 Preparation of Rubber Reinforced Styrene Resin (A) Preparation Polybutadiene Latex (A mixture of a polybutadiene latex having a weight average particle size of 350 nm and a polybutadiene latex having a weight average of 800 nm in a mass ratio of 8: 2) 45 mass % (Solid content conversion), a monomer mixture composed of 40% by mass of styrene and 15% by mass of acrylonitrile was subjected to emulsion polymerization using potassium stearate to obtain a rubber-reinforced styrene resin latex. This was added and aggregated in a 0.3% by mass dilute sulfuric acid aqueous solution at 90 ° C., and then neutralized with an aqueous sodium hydroxide solution, followed by washing, dehydration and drying steps, and then a diene graft copolymer (A1). ) Was prepared. The graft ratio was 25% by mass. The weight average particle size of polybutadiene in the polybutadiene latex was measured with a particle size distribution measuring apparatus using a laser diffraction / scattering method after diluting the polybutadiene latex 300 to 500 times with pure water. Further, using a continuous bulk polymerization apparatus composed of a preheater and a demonomer, a monomer mixture composed of 72% by mass of styrene and 28% by mass of acrylonitrile was continuously polymerized at 135 kg / hour. In the polymerization reaction mixture, unreacted monomers were collected by evaporation under reduced pressure from a vent port using a single screw extruder type demonomer, while a vinyl copolymer (A2) was obtained from the demonomer. The intrinsic viscosity of the obtained vinyl copolymer was 0.50 dl / g. The average content of the structural units derived from the vinyl cyanide monomer (a3) was 26% by mass. 30 parts by mass of diene graft copolymer (A1) and 70 parts by mass of vinyl copolymer (A2) were mixed to obtain 100 parts by mass of rubber-reinforced styrene resin (A).

In addition, the raw material used for each Example and the comparative example is shown below.
Polycarbonate resin (B-1); trade name "" IUPILON "(registered trademark) S-2000", temperature 300 ° C., a melt volume rate 10 cm ^3/10 min at a load 1.2kg condition, manufactured by Mitsubishi Engineering Plastics Co., Ltd. Graft copolymer (C-1); trade name “Modiper” (registered trademark) A5400, segment (I) ethylene-ethyl acrylate / segment (II) acrylonitrile-styrene copolymer, NOF's graft Copolymer (C-2); trade name "" MODIPER "A5100", segment (I) ethylene-ethyl acrylate copolymer / segment (II) polystyrene, ethylene / (meth) acrylic ester manufactured by NOF Corporation / Carbon monoxide copolymer (D-1); trade name "" Elvalloy "(registered trademark) HP- 051 ", ethylene / n-butyl acrylate / carbon monoxide copolymer, graft copolymer (E-1) containing epoxy group manufactured by Mitsui DuPont Polychemical Co., Ltd .; trade name""MODIPER" A4400 " , A graft copolymer obtained by graft copolymerization of acrylonitrile and styrene with an ethylene / glycidyl methacrylate copolymer, polyethylene (F-1) manufactured by NOF Corporation; trade name "" PETROcene "(registered trademark) 232" , Low density polyethylene, manufactured by Tosoh Corporation.

(Examples 1-8, Comparative Examples 1-8)
The rubber-reinforced styrene resin (A), polycarbonate resin (B), graft copolymer (C), ethylene / (meth) acrylate / carbon monoxide copolymer (D), graft copolymer (E ), Polyethylene (F) are blended in the ratios shown in Tables 1 and 2, and melt-kneaded in a twin-screw extruder (temperature range: 240 to 260 ° C.) rotating in the same direction with a screw diameter of 30 mm, Obtained. A test piece was prepared from the obtained pellet using an injection molding machine (molding temperature 250 ° C., mold temperature 60 ° C.), and evaluated by the method described above. However, the molded product for evaluation of delamination of (5), the square plate for evaluation of coating arm of (6), and the test piece for evaluation of coating film smoothness of (7) are (5), (6) And it produced on the conditions as described in (7). Table 1 shows the results of the examples and Table 2 shows the results of the comparative examples.

  Examples 1 to 8, i.e., the thermoplastic resin compositions of the present invention, all have high fluidity, excellent impact resistance and coating film smoothness, and a molded product with a small amount of peeling during layering and coating is obtained. It is done. On the other hand, from the comparison between Example 1 and Comparative Examples 1 to 3, the content of the graft copolymer (C) and / or ethylene / (meth) acrylic acid ester / carbon monoxide copolymer (D) is defined in the present invention. It can be seen that if the amount is less than the range to be applied, the cracks are likely to occur during painting. Moreover, when the content of the graft copolymer (C) is larger than the range specified in the present invention, it can be seen from the comparison between Example 1 and Comparative Example 4 that the coating film smoothness is lowered. From a comparison between Example 1 and Comparative Example 5, when the content of ethylene / (meth) acrylic acid ester / carbon monoxide copolymer (D) is larger than the range specified in the present invention, delamination is likely to occur. I understand that. From a comparison between Example 1 and Comparative Example 6, it can be seen that when the graft copolymer (E) containing an epoxy group is contained instead of the graft copolymer (C), the fluidity is lowered. From the comparison between Example 1 and Comparative Example 7, it can be seen that when polyethylene (F) is contained instead of ethylene / (meth) acrylic acid ester / carbon monoxide copolymer (D), delamination is likely to occur. . From a comparison between Example 1 and Comparative Example 8, it can be seen that when the polycarbonate resin (B) content is less than the range defined in the present invention, the impact resistance is lowered.

  Since the thermoplastic resin composition of the present invention can provide a molded article having excellent impact resistance and coating film smoothness, and having suppressed delamination and cracking phenomenon, for example, a power window panel which is an automotive interior part, It can be suitably used for applications that require fluidity, impact resistance, and paint resistance (reduction of paint cracking phenomenon) such as center consoles, center clusters, lever controllers, and console boxes.

Claims (4)

  Rubber-reinforced styrene-based resin (A), polycarbonate-based resin (B), copolymer segment (I) composed of α-olefin monomer and acrylic acid alkyl ester monomer, and vinyl composed of vinyl-based monomer A thermoplastic resin composition comprising a graft copolymer (C) having a polymer segment (II) and an ethylene / (meth) acrylic acid ester / carbon monoxide copolymer (D), wherein the rubber 1 to 10 parts by mass of the graft copolymer (C) and the ethylene / (meth) acrylate / carbon monoxide with respect to a total of 100 parts by mass of the reinforced styrene resin (A) and the polycarbonate resin (B). A thermoplastic resin composition containing 0.05 to 1 part by mass of a copolymer (D).   The copolymer segment (I) composed of the α-olefin monomer and the acrylic acid alkyl ester monomer is a copolymer segment composed of ethylene and ethyl acrylate, and the vinyl polymer composed of the vinyl monomer. The thermoplastic resin composition according to claim 1, wherein the coalesced segment (II) is a copolymer segment comprising acrylonitrile and styrene.   20 to 70 parts by mass of rubber reinforced styrene resin (A) and 30 to 80 parts of polycarbonate resin (B) with respect to 100 parts by mass in total of the rubber reinforced styrene resin (A) and the polycarbonate resin (B). The thermoplastic resin composition according to claim 1 or 2, which contains part by mass.   The molded object formed by injection-molding the thermoplastic resin composition in any one of Claims 1-3.