JP2013047288A - Black resin composition and molding obtained by molding the resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a black resin composition which is excellent in mechanical strength and impact resistance, also is excellent in black appearance, and is broadly available for various products, in an alloy-based resin composition using a polylactic acid resin.SOLUTION: The black resin composition is a resin composition containing a polylactic acid resin (A), a polycarbonate resin (B), an acrylonitrile-styrene-butadiene copolymer resin (C), an acryl/styrene copolymer (D), and a black colorant (E), wherein the content of the polylactic acid resin (A) is 20-50 mass%, the content of the polycarbonate resin (B) is 30-60 mass%, the content of the acrylonitrile-styrene-butadiene copolymer resin (C) is 2-20 mass%, the content of the acryl/styrene copolymer (D) is 0.5-10 mass%, and the content of the black colorant (E) is 0.1-5 mass%.

Description

  The present invention relates to a black resin composition and a molded body formed by molding the resin composition.

  In recent years, biomass raw material resins such as polylactic acid resins have attracted attention from the viewpoint of environmental conservation. Among the resins derived from biomass, polylactic acid resin is one of highly useful resins because it has high heat resistance and can be mass-produced, so the cost is low.

  Furthermore, since polylactic acid resin can be produced using plants such as corn and sweet potato as raw materials, it can contribute to saving of depleted resources such as petroleum. Moreover, since the polylactic acid resin is a plant-derived resin, the carbon in the raw material is obtained by immobilizing carbon in the atmosphere. Therefore, since underground carbon is not brought into the ground like oil, the problem of global warming due to an increase in carbon dioxide emissions can be prevented.

  Polylactic acid resin has high heat resistance among biomass-derived resins. However, heat resistance may not always be sufficient when compared with general-purpose resins such as polypropylene resin (PP), acrylonitrile-styrene-butadiene copolymer resin, and polycarbonate resin. In addition, polylactic acid resin has low mechanical properties, especially impact strength, and sufficiently satisfies the required performance when used for automotive parts and home appliance housings that use general-purpose resins as described above. There is a problem of not doing.

  In order to compensate for the drawbacks of such polylactic acid resins, alloy resins of polylactic acid resins and resins other than polylactic acid resins have been studied. In particular, alloy resin of polylactic acid resin and aromatic polycarbonate resin excellent in heat resistance and impact resistance, and alloy resin of polylactic acid resin and rubber reinforced styrene resin such as acrylonitrile-styrene-butadiene copolymer resin, etc. Proposed. Such an alloy resin has an effect of reducing environmental burdens such as saving of petroleum resources and reduction of carbon dioxide emission as compared with a resin obtained from only petroleum-derived raw materials.

  However, such an alloy resin has a property that the appearance has a pearly luster. When mixing a colorant directly with such an alloy resin having pearly luster, there is no problem if a white colorant is mixed, but when a black colorant is blended, the resulting resin composition is molded. When it was made into a body, it had a slightly whitish appearance, and there was a problem that a good appearance with a jet black feeling could not be obtained.

  As a method for obtaining a molded product having a jet black feeling and a good appearance, after obtaining the molded product from the resin composition, a method of painting the surface of the molded product in black, or a black coloring added to the alloy resin And a method of increasing the amount of the agent. However, when these methods are adopted, there are problems that the environmental load increases, the cost increases, and the impact resistance decreases.

  Therefore, in order to reduce the pearly luster of such a resin composition, it has been studied to improve the compatibility and dispersibility of the alloy resin. For example, Patent Document 1 describes a flame retardant resin composition comprising a polylactic acid resin, an aromatic polycarbonate resin, an acrylic resin or a polymer compound containing a styrene resin unit by grafting, and a flame retardant. .

  Patent Document 2 describes an impact-resistant thermoplastic resin composition comprising a polylactic acid-based polymer, a thermoplastic resin such as a polyvinyl chloride-based resin, and a graft copolymer.

  Furthermore, Patent Document 3 describes a resin composition comprising a polylactic acid resin, an aromatic polycarbonate resin, and at least one selected from an oxazoline compound, an oxazine compound and a carbodiimide compound.

  In any of the methods of Patent Documents 1 to 3, the appearance is improved and the physical properties are improved. However, when the resin compositions of Patent Documents 1 to 3 are colored with a black colorant, a large amount of black colorant needs to be added in order to obtain a high-quality jetness. Therefore, the balance between physical properties such as impact resistance and cost has not been satisfactory.

JP 2007-56247 A JP 2005-320409 A JP 2007-56246 A

  Accordingly, an object of the present invention is to solve the above problems, and in a resin composition using a polylactic acid resin, it is excellent in mechanical strength and impact resistance, and has a black appearance with a jet black feeling. An object of the present invention is to provide a black resin composition that can be widely used in products.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors contain a polylactic acid resin, a polycarbonate resin, an acrylonitrile-styrene-butadiene copolymer resin, an acrylic / styrene copolymer, and a black pigment in a specific ratio. It has been found that a black resin composition capable of solving the above problems has reached the present invention.

That is, the present invention has the following contents.
(1) Resin composition containing polylactic acid resin (A), polycarbonate resin (B), acrylonitrile-styrene-butadiene copolymer resin (C), acrylic / styrene copolymer (D) and black colorant (E) The content of the polylactic acid resin (A) in the resin composition is 20 to 50% by mass, the content of the polycarbonate resin (B) is 30 to 60% by mass, and the acrylonitrile-styrene-butadiene copolymer resin. The content of (C) is 2 to 20% by mass, the content of the acrylic / styrene copolymer (D) is 0.5 to 10% by mass, and the content of the black colorant (E) is 0.1 to 5%. A black resin composition characterized by being in mass%.
(2) The black resin composition according to (1), further comprising 1 to 15% by mass of a core-shell type acrylic polymer (F).
(3) The black resin composition according to (1) or (2), wherein the black colorant (E) is carbon black and / or nigrosine.
(4) The black resin composition according to any one of (1) to (3), further comprising 0.1 to 5% by mass of a carbodiimide compound (G).
(5) A molded article obtained by molding the black resin composition of any one of (1) to (4).

  According to the black resin composition of the present invention, while using a polylactic acid resin, it has excellent mechanical strength and impact resistance, and is an alloy resin mixed with other resins, but has a high quality. It becomes possible to obtain a molded body having a jet black appearance. Furthermore, a molded body can be obtained by subjecting the black resin composition of the present invention to injection molding or the like, and the molded body can be used in various applications such as mechanical mechanism parts, electrical / electronic parts, building members, automobile parts, and daily necessities. Can be used effectively. Furthermore, since the black resin composition of the present invention uses a resin derived from a natural product, it can contribute to saving resources such as petroleum and reducing carbon dioxide emissions. Extremely high.

Hereinafter, the present invention will be described in detail.
The black resin composition of the present invention (hereinafter sometimes referred to as “resin composition”) comprises a polylactic acid resin (A), a polycarbonate resin (B), an acrylonitrile-styrene-butadiene copolymer resin (hereinafter referred to as “ABS”). Resin (which may be abbreviated as “resin”), an acrylic / styrene copolymer (D) and a black colorant (E).

  First, the polylactic acid resin (A) will be described. Examples of the polylactic acid resin (A) include poly (L-lactic acid), poly (D-lactic acid), and mixtures or copolymers thereof.

  In the polylactic acid resin (A) in the present invention, the D-lactic acid content is preferably 1.0 mol% or less, or the D-lactic acid content is preferably 99.0 mol% or more. When the D-lactic acid content is within this range, the crystallinity is excellent, so that the obtained resin composition has excellent moldability (that is, the molding cycle is shortened), and from the resin composition The obtained molded body has improved heat resistance.

  In the present invention, the D-lactic acid content of the polylactic acid resin (A) is the ratio (mol%) occupied by the D-lactic acid units in the total lactic acid units constituting the polylactic acid resin (A). Therefore, for example, in the case of a polylactic acid resin (A) having a D-lactic acid content of 1.0 mol%, this polylactic acid resin (A) has a ratio of D-lactic acid units of 1.0 mol%, The proportion of L-lactic acid units is 99.0 mol%.

  The melt flow rate (hereinafter sometimes abbreviated as “MFR”) of the polylactic acid resin (A) by the measurement method described later is preferably from 0.1 to 50 g / 10 minutes, and from 0.2 to 20 g / 10 minutes. More preferred is 0.5 to 15 g / 10 min. If the MFR exceeds 50 g / 10 min, the melt viscosity is too low and the mechanical properties and heat resistance of the molded product may be inferior. On the other hand, if the MFR is less than 0.1 g / 10 minutes, the load during the molding process increases, and the operability may decrease.

  The polylactic acid resin (A) is produced by a known melt polymerization method or, if necessary, further using a solid phase polymerization method.

  The content of the polylactic acid resin (A) in the black resin composition of the present invention needs to be 20 to 50% by mass, and preferably 25 to 40% by mass. When the content of the polylactic acid resin (A) is less than 20% by mass, the environmental load cannot be sufficiently reduced. On the other hand, when the content exceeds 50% by mass, the content of other resins is reduced, so that the resin composition is inferior in mechanical strength and impact resistance.

Next, the polycarbonate resin (B) will be described.
The polycarbonate resin (B) used in the present invention refers to a resin composed of bisphenol residues and carbonate residues.

  Examples of bisphenols include 2,2-bis (4-hydroxyphenyl) propane (hereinafter abbreviated as bisphenol A), 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (hereinafter referred to as “bisphenol A”). , Abbreviated as bisphenol TMC), 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1 -Bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) decane, 1,3-bis (4- Hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclododecane, 4,4'-dihydroxydiphe Ether, 4,4'-dithio-diphenol, 4,4'-dihydroxy-3,3'-dichloro-diphenyl ether, 4,4'-dihydroxy-2,5-dihydroxydiphenyl ether, and the like. Among these, bisphenol A and bisphenol TMC are preferable from the viewpoint of versatility. These may be used alone or in combination of two or more.

  The polycarbonate resin (B) can be produced by a known method. For example, a method of reacting bisphenols with phosgene or bisphenols with diphenyl carbonate can be mentioned.

  The intrinsic viscosity of the polycarbonate resin (B) is preferably in the range of 0.35 to 0.64. When the intrinsic viscosity of the polycarbonate resin (B) is less than 0.35, the impact strength of the obtained molded product may be insufficient. On the other hand, when the intrinsic viscosity of the polycarbonate resin (B) exceeds 0.64, the resin The melt viscosity of the composition becomes high, and kneading extrusion and injection molding may be difficult.

  The content of the polycarbonate resin (B) in the black resin composition of the present invention needs to be 30 to 60% by mass, and preferably 35 to 55% by mass. When the content of the polycarbonate resin (B) is less than 30% by mass, the resin composition is inferior in mechanical strength, impact resistance, and heat resistance. On the other hand, when the content exceeds 60% by mass, the content of the polylactic acid resin (A) in the resin composition is decreased, so that the environmental load cannot be sufficiently reduced.

Next, the ABS resin (C) will be described.
Examples of the ABS resin in the present invention include a terpolymer obtained by emulsion polymerization of acrylonitrile, butadiene and styrene, a mixture of acrylonitrile-styrene resin and nitrile rubber (acrylonitrile-butadiene rubber), and a graft copolymer of styrene to nitrile rubber. A well-known thing can be used. Among these, a terpolymer obtained by emulsion polymerization is preferably used. The copolymer composition of the ABS resin (C) is 15 to 80% by mass of the butadiene component, 85 to 20% by mass of the total of the acrylonitrile component and the styrene component, and the mass ratio of the acrylonitrile component to the styrene component is 5/95 to 50%. A ratio of / 50 is appropriate.

  The ABS resin (C) may contain a small amount of copolymer components such as isoprene, phenylmaleimide, methyl acrylate and methyl methacrylate in addition to these three components.

  The content of the ABS resin (C) in the black resin composition of the present invention is required to be 2 to 20% by mass, and preferably 5 to 18% by mass. When the content of the ABS resin (C) is less than 2% by mass, the resin composition is inferior in mechanical strength and impact resistance. On the other hand, if the content exceeds 20% by mass, the content of the polylactic acid resin (A) in the resin composition decreases, so that the environmental load cannot be sufficiently reduced, and the heat resistance is inferior. It becomes.

Next, the acrylic / styrene copolymer (D) will be described.
The acrylic / styrene copolymer (D) used in the present invention is a copolymer of a styrene monomer and a meta (acrylic acid) ester monomer that can be copolymerized with the styrene monomer. In the black resin composition of the present invention, when a predetermined amount of the acrylic / styrene copolymer (D) is contained, the dispersibility of the black colorant (E) in the resin composition becomes good, and the above-mentioned The compatibility of the components (A) to (C) can also be improved. Therefore, without adding a large amount of the black colorant (E), a sufficiently black resin composition can be obtained, and a high-quality resin composition can be obtained. And since compatibility of a resin composition can also be improved, there exists an effect which improves mechanical strength and impact resistance. Even if a dispersant other than the acrylic / styrene copolymer (D) is used, the dispersibility of the black colorant (E) cannot be sufficiently improved.

  Examples of styrenic monomers include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, vinylxylene, ethylstyrene, dimethylstyrene, p-tert-butylstyrene, vinylnaphthalene, methoxystyrene, Examples thereof include styrene derivatives such as monobromostyrene, dibromostyrene, fluorostyrene, and tribromostyrene. Of these, styrene and α-methylstyrene are preferable. These may be used alone or in combination of two or more.

  (Meth) acrylic acid ester monomers copolymerized with styrene monomers include aryl esters of (meth) acrylic acid such as phenyl acrylate and benzyl acrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl Examples include (meth) acrylic acid alkyl esters such as acrylate, 2-ethylhexyl acrylate, octyl acrylate, cyclohexyl acrylate, and dodecyl acrylate, and epoxy group-containing methacrylic acid esters such as methyl methacrylate and glycidyl methacrylate. These may be used independently and may use 2 or more types together.

  As the (meth) acrylic acid ester monomer to be copolymerized with the styrene monomer, a monomer containing glycidyl methacrylate is preferable. By containing glycidyl methacrylate, not only the black appearance is improved, but also the heat resistance of the resin composition is improved.

  Such acrylic / styrene copolymer (D) may be a commercially available product. Specific examples thereof include “ARUFON UG-4035”, “UG-4040”, “UG-” manufactured by Toa Gosei Co., Ltd. 4070 series ".

  Moreover, as a copolymerization ratio of the styrene monomer and the (meth) acrylic acid ester monomer, the ratio of the (meth) acrylic acid ester monomer-derived portion in the acrylic / styrene copolymer (D) is 60% by mass or more. It is preferable that By using such a copolymer as the acrylic / styrene copolymer (D), there is an advantage that the effect of improving the black appearance is further enhanced. As such a copolymer, a commercially available product can be suitably used. Specific examples thereof include “Acryloy KT-80” manufactured by Denki Kagaku Kogyo Co., Ltd.

  In the acrylic / styrene copolymer (D), maleimide, maleic acid, maleic anhydride and the like are copolymerized as components other than the above as long as the performance and effects of the black resin composition of the present invention are not impaired. Also good.

  The content of the acrylic / styrene copolymer (D) in the black resin composition of the present invention is required to be 0.5 to 10% by mass, particularly 0.5 to 6% by mass. Is preferred. When the content of the acrylic / styrene copolymer (D) is less than 0.5% by mass, the effect of sufficiently dispersing the black colorant as described above is insufficient, and a molded article having a high-quality jetness is obtained. It becomes difficult. On the other hand, when the content of the acrylic / styrene copolymer (D) exceeds 10% by mass, impact resistance and mechanical strength of the resulting resin composition are lowered.

The black colorant (E) will be described.
As the black colorant (E), both pigments and dyes can be used. Examples of the pigment system include carbon black, iron black, and titanium black pigment. Examples of the dye system include nigrosine, which is an azine compound condensed with aniline and nitrobenzene. Among these, carbon black and nigrosine are preferable from the viewpoint of physical properties and a good black appearance. A plurality of these colorants may be used in combination.

  The content of the black colorant (E) in the black resin composition of the present invention needs to be 0.1 to 5% by mass, and preferably 0.5 to 3% by mass. . When the content of the black colorant (E) is less than 0.1% by mass, it cannot be sufficiently colored black, and a molded product having a jet black feeling cannot be obtained. On the other hand, when the content of the black colorant (E) exceeds 5% by mass, the impact resistance and mechanical strength of the resulting resin composition are lowered.

  In the black resin composition of the present invention, in addition to the components (A) to (E) described above, it is preferable to further contain a core-shell type acrylic polymer (F). By containing the core-shell type acrylic polymer (F), the impact resistance of the resin composition can be further improved.

  The core-shell type acrylic polymer is composed of a layer having a rubber layer as an inner layer and a (meth) acrylic resin as an outer layer. As an example of the structure of the core-shell type acrylic polymer, the core (inner layer) is composed of a rubber obtained by polymerizing an acrylic component, a silicone component, a styrene component, a nitrile component, a conjugated diene component, a urethane component or an ethylene propylene component. And a shell (outer layer) is composed of a methyl methacrylate polymer or the like.

  As the core-shell type acrylic polymer (F), commercially available products can be suitably used. For example, “Metablene” manufactured by Mitsubishi Rayon Co., “Kaneace” manufactured by Kaneka Chemical Co., Ltd., “Paraloid” manufactured by Kureha Chemical Co., Ltd. "Acryloid" manufactured by Rohm and Haas, "Staffyroid" manufactured by Takeda Pharmaceutical Co., Ltd., "Parapet SA" manufactured by Kuraray. These may be used alone or in combination of two or more.

  The content of the core-shell type acrylic polymer resin (F) in the black resin composition of the present invention needs to be 1 to 15% by mass, and preferably 3 to 12% by mass. When the content of the core-shell type acrylic polymer resin (F) is less than 1% by mass, the effect of improving impact resistance is poor. On the other hand, when content exceeds 15 mass%, the heat resistance in a resin composition will fall.

  The black resin composition of the present invention preferably further contains a carbodiimide compound (G) in order to improve the wet heat durability of the polylactic acid resin.

  The carbodiimide compound (G) refers to a compound having a carbodiimide group represented by (—N═C═N—) in the molecule. A compound having one carbodiimide group in the molecule is referred to as a monocarbodiimide compound, and a compound having two or more carbodiimide groups in the molecule is referred to as a polyvalent carbodiimide compound.

  As the carbodiimide compound (G), it is preferable to use a monocarbodiimide compound and a polyvalent carbodiimide compound in combination.

  By using a monocarbodiimide compound and a polyvalent carbodiimide compound in combination, wet heat durability is improved as compared with the case where each is used alone. The reason is not clear, but can be estimated as follows.

  It is known that hydrolysis of polylactic acid molecules is promoted by carboxylic acid end groups. The monocarbodiimide compound has a small molecular weight and is easy to move, so it has excellent dispersibility and quickly reacts with the carboxylic acid end of the polylactic acid molecule to block the end of the polylactic acid molecule. On the other hand, when polylactic acid is hydrolyzed and a carboxylic acid terminal is newly generated, the polyvalent carbodiimide compound reacts with the generated carboxylic acid terminal to extend the chain and increase the molecular weight, thereby suppressing a decrease in molecular weight. For this reason, it is estimated that wet heat durability improves drastically.

  In the case where a monocarbodiimide compound and a polyvalent carbodiimide compound are used in combination as the carbodiimide compound (G), the mass ratio between the content of the monocarbodiimide compound and the content of the polyvalent carbodiimide compound is in the range of 10/90 to 90/10. It is preferable that the range is 30/70 to 70/30. When the mass ratio between the monocarbodiimide compound and the polyvalent carbodiimide compound is within this range, an effect that extremely excellent wet heat durability is obtained is exhibited.

  As monocarbodiimide compounds, N, N′-di-p-chlorophenylcarbodiimide, N, N′-di-o-chlorophenylcarbodiimide, N, N′-di-3,4-dichlorophenylcarbodiimide, N, N'-di-2,5-dichlorophenylcarbodiimide, p-phenylene-bis-o-toluylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, p-phenylene-bis-di-p-chlorophenylcarbodiimide, hexamethylene -Bis-cyclohexylcarbodiimide, ethylene-bis-diphenylcarbodiimide, ethylene-bis-di-cyclohexylcarbodiimide, N, N'-di-o-triylcarbodiimide, N, N'-diphenylcarbodiimide, N, N'-dioctyldecyl Carbodiimide, N, '-Di-2,6-dimethylphenylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N, N'-di-2,6-diisopropylphenylcarbodiimide, N, N'-di-2,6-di- tert-butylphenylcarbodiimide, N-toluyl-N′-phenylcarbodiimide, N, N′-di-p-nitrophenylcarbodiimide, N, N′-di-p-aminophenylcarbodiimide, N, N′-di-p -Hydroxyphenylcarbodiimide, N, N'-di-cyclohexylcarbodiimide, N, N'-di-p-toluylcarbodiimide, N, N'-benzylcarbodiimide, N-octadecyl-N'-phenylcarbodiimide, N-benzyl-N '-Phenylcarbodiimide, N-octadecyl-N'-tolylcarbodiimide N-cyclohexyl-N'-tolylcarbodiimide, N-phenyl-N'-tolylcarbodiimide, N-benzyl-N'-tolylcarbodiimide, N, N'-di-o-ethylphenylcarbodiimide, N, N'-di- p-ethylphenylcarbodiimide, N, N'-di-o-isopropylphenylcarbodiimide, N, N'-di-p-isopropylphenylcarbodiimide, N, N'-di-o-isobutylphenylcarbodiimide, N, N'- Di-p-isobutylphenylcarbodiimide, N, N'-di-2,6-diethylphenylcarbodiimide, N, N'-di-2-ethyl-6-isopropylphenylcarbodiimide, N, N'-di-2-isobutyl -6-Isopropylphenylcarbodiimide, N, N'-di-2,4,6-trimethyl Phenyl carbodiimide, N, N'-di-2,4,6-triisopropyl phenyl carbodiimide, N, N'-di-2,4,6-isobutylphenyl carbodiimide and the like. Among these, N, N′-di-2,6-diisopropylphenylcarbodiimide is preferable from the viewpoint of wet heat durability.

  Examples of the polyvalent carbodiimide compound include poly (1,6-hexamethylenecarbodiimide), poly (4,4′-methylenebiscyclohexylcarbodiimide), poly (1,3-cyclohexylenecarbodiimide), and poly (1,4-cyclohexylene). Carbodiimide), poly (4,4′-diphenylmethanecarbodiimide), poly (3,3′-dimethyl-4,4′-diphenylmethanecarbodiimide), poly (naphthylenecarbodiimide), poly (p-phenylenecarbodiimide), poly (m -Phenylenecarbodiimide), poly (tolylcarbodiimide), poly (diisopropylcarbodiimide), poly (methyl-diisopropylphenylenecarbodiimide), poly (triethylphenylenecarbodiimide), poly (triisopropylphenylene) Carbodiimide), poly (1,3,5-triisopropylbenzene) carbodiimide, poly (1,5-diisopropylbenzene) carbodiimide, and the like. Of these, poly (4,4′-methylenebiscyclohexylcarbodiimide), poly (1,3,5-triisopropylbenzene) carbodiimide, and poly (1,5-diisopropylbenzene) carbodiimide are preferable.

  The carbodiimide compound (G) can be produced by a known method. For example, the method of manufacturing by the carbon dioxide removal reaction of a diisocyanate compound is mentioned. In the present invention, an isocyanate group may remain at the terminal of the carbodiimide compound (G).

  The content of the carbodiimide compound (G) in the black resin composition of the present invention is preferably 0.1 to 5% by mass, and more preferably 0.5 to 3% by mass. If content of a carbodiimide compound (G) is less than 0.1 mass%, the effect which improves wet heat durability may be scarce. On the other hand, when the content exceeds 5% by mass, heat resistance and impact resistance may be lowered.

  Further, in the resin composition of the present invention, the polylactic acid resin (A), polycarbonate resin (B), acrylonitrile-styrene-butadiene copolymer resin (C), acrylic / styrene copolymer (D) as described above. Other thermoplastic resins can be blended within a range that does not impair the effects of the present invention. Specific examples of such thermoplastic resins include polyester resins, phenoxy resins, cellulose ester resins, polyamide resins, polyetherimide resins, ionomer resins, polyphenylene ether resins, polyphenyl sulfide resins, and phenol resins.

  The resin composition of the present invention may contain an inorganic filler such as glass fiber for the purpose of improving mechanical strength and heat resistance. The content is usually about 1 to 50 parts by mass with respect to 100 parts by mass of the finally obtained resin composition.

  Any conventionally known glass fiber can be used as the glass fiber. Moreover, in order to improve adhesiveness with resin, you may process to the surface of glass fiber. As a method for incorporating the glass fiber into the resin composition of the present invention, the glass fiber can be added from the hopper or in the middle of the kneading using the side feeder in an extruder. Moreover, it can also use by diluting with a base resin at the time of shaping | molding by carrying out a masterbatch process of glass fiber.

  The resin composition of the present invention can be blended with a flame retardant for the purpose of imparting flame retardancy. Examples of the flame retardant include phosphorus-based flame retardants such as phosphoric acid esters and phosphinic acid metal salts, silicone-based flame retardants, and inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide. Two or more of these flame retardants can be used in combination.

  It is preferable that content of a flame retardant is 5-30 mass parts with respect to 100 mass parts of resin compositions of this invention finally obtained. If the content of the flame retardant is less than 5 parts by mass, the flame retardancy of the resin composition may be insufficient. On the other hand, when content of a flame retardant exceeds 30 mass parts, there exists a tendency for the intensity | strength of a resin composition to fall.

  The resin composition of the present invention includes a pigment, a heat stabilizer, an antioxidant, a weathering agent, a light-proofing agent, a plasticizer, a lubricant, a release agent, an antistatic agent, and a filler, as long as the effects of the present invention are not impaired. Materials, crystal nucleating agents, etc. can be added.

  Examples of heat stabilizers and antioxidants include hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, alkali metal halides, and vitamin E.

  Examples of the filler include inorganic fillers and organic fillers. Inorganic fillers other than glass fiber include talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon , Carbon black, zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate, boron nitride, graphite, carbon fiber and the like.

  Examples of the organic filler include naturally occurring polymers such as starch, cellulose fine particles, wood flour, okara, fir shell, bran, and modified products thereof.

  Examples of the crystal nucleating agent include inorganic crystal nucleating agents and organic crystal nucleating agents. Examples of the inorganic crystal core material include talc and kaolin.

  Examples of the organic crystal nucleus material include sorbitol compounds, benzoic acid and metal salts thereof, phosphoric acid ester metal salts, rosin compounds, fatty acid amide compounds, aromatic amide compounds, phenylphosphonic acid metal salts, sulfonic acid metal salts, and the like. It is done.

  In addition, the method of mixing these various flame retardants with the resin composition of this invention is not specifically limited, Arbitrary methods can be used.

  Next, the manufacturing method of the resin composition of this invention is demonstrated. The method of blending each raw material is not particularly limited as long as each component is uniformly dispersed in the resin composition. Specifically, when the carbodiimide compound (G) is not contained, the polylactic acid resin (A), the polycarbonate resin (B), the acrylonitrile-styrene-butadiene copolymer resin (C), and acrylic / styrene are used in the order of melt kneading. The copolymer (D) and the black colorant (E), and, if necessary, the core-shell type acrylic polymer (F) and other additives are uniformly blended using a tumbler or Henschel mixer. Then, the method of melt-kneading and pelletizing is mentioned.

  When the carbodiimide compound (G) is contained, the polylactic acid resin (A), the polycarbonate resin (B), the acrylonitrile-styrene-butadiene copolymer resin (C), and the acrylic / styrene copolymer are used in the order of melt kneading. (D) and the black colorant (E), and further, if necessary, after melt-kneading the core-shell type acrylic polymer (F) and other additives, the carbodiimide compound (G) is melt-kneaded, The physical properties and durability of the resin composition are likely to be improved.

  In the method for producing the resin composition of the present invention, as a method of blending each raw material, a method is obtained by mixing each raw material with an arbitrary organic solvent to obtain a solution, and then removing the solvent from the solution. be able to.

  The resin composition of the present invention can be formed into various molded products by a molding method such as injection molding, blow molding, extrusion molding, inflation molding, and vacuum molding, pressure molding, vacuum pressure molding, etc. after sheet processing. In particular, an injection molding method is preferable, and in addition to a general injection molding method, gas injection molding, injection press molding, or the like can be employed.

  The injection molding conditions suitable for the resin composition of the present invention are not particularly limited as long as there is no problem in molding and performance, but the cylinder temperature is in the range of 180 to 260 ° C, more preferably 190 to 250 ° C. Is appropriate. The mold temperature is preferably 100 ° C. or lower. If the molding temperature is too low, the operability becomes unstable, for example, a short circuit occurs in the molded body, or it tends to be overloaded. On the other hand, if the molding temperature is too high, the resin composition may be decomposed to cause problems such as a decrease in strength of the resulting molded product or occurrence of coloring.

  The heat resistance of the resin composition of the present invention can be enhanced by promoting crystallization. As a method of promoting crystallization, for example, there is a method of promoting crystallization by cooling in a mold during injection molding. In that case, it is desirable to cool the mold temperature for a predetermined time at the crystallization temperature of the resin composition ± 20 ° C. In consideration of releasability, the mold temperature may be further lowered to below the glass transition temperature of the resin composition, and then the mold may be opened to take out the molded product.

  As a method for promoting crystallization after molding, it is preferable to heat-treat the obtained molded body again at a crystallization temperature of ± 20 ° C. When there are a plurality of glass transition temperatures, a glass transition temperature that does not cause a problem in molding may be selected.

  Examples of the molded article of the present invention obtained from the resin composition of the present invention include injection molded articles, extruded molded articles, blow molded articles, films, fibers and sheets. In particular, it can be suitably used as an injection-molded product, particularly a thin-walled injection-molded product. Further, these molded articles can be used for various applications such as electric / electronic parts, mechanical parts, optical equipment, building members, automobile parts, and daily necessities.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

1. Evaluation item (1) Melt flow rate (MFR)
According to JIS standard K-7210 (test condition 4), the measurement was performed at 190 ° C., a load of 21.2 N or 220 ° C., and a load of 98 N. In the present invention, the MFR at 220 ° C. and a load of 98 N is preferably 10 g / min or more from the viewpoint of molding processability.

(2) Intrinsic viscosity The intrinsic viscosity was measured under the conditions of a concentration of 1 g / dl and a temperature of 25 ° C. using 1,1,2,2-tetrachloroethane as a measurement solvent.

(3) Thermal deformation temperature (DTUL)
Using the obtained test piece (10 × 4 mm), the heat deformation temperature under a load of 1.8 MPa was measured according to ISO standards 75-1 and 75-2. At a load of 1.8 MPa, 60 ° C. or higher is desirable.

(4) Bending strength Using the obtained test piece (10 × 4 mm), in accordance with ISO standard 178, a load was applied at a deformation rate of 1 mm / min, and the bending strength was measured.

(5) Impact strength (Charpy impact strength)
Charpy impact strength was measured according to ISO standard 179-1eA using the obtained test piece with a notch (V-shaped cut). In the present invention, the Charpy impact strength is preferably 9 kJ / m ² or more from the viewpoint of actual use.

(6) Black appearance About the obtained test piece (10x4mm), the sharpness glossiness of the molded object was measured using the portable sharpness glossiness meter (made by Nippon Color Research Institute, "PGD"). . In addition, the value of sharpness and glossiness is a number from 2.0 to 0.1, and the larger the number, the better. In this invention, it is judged that it is what is excellent in a black external appearance (jet black feeling) that the value of a definition glossiness is 1.0 or more.

(7) Moisture and heat resistance The obtained test piece (10 × 4 mm) was treated for 1500 hours in an environment of a temperature of 60 ° C. and a humidity of 95% RH, and then the bending strength was measured in the same manner as in (4). And the intensity | strength retention with respect to the value of the bending strength of an untreated goods was computed by the following formula.
Strength retention ratio (%) = [(Bending strength of test specimen after treatment) / (Bending strength of untreated specimen)] × 100

2. Raw material (1) Polylactic acid resin “NatureWorks 3001DK” manufactured by Nature Works (MFR: 10 g / 10 min, melting point: 168 ° C.)

(2) Polycarbonate resin “200-13” manufactured by Sumitomo Dow (Intrinsic viscosity: 0.49)

(3) “ABS150” manufactured by ABS resin Technopolymer Co., Ltd.

(4) Acrylic / styrene copolymer / copolymer of methyl methacrylate and styrene (methyl methacrylate / styrene (molar ratio) = 90/10, “KT-80” manufactured by Denki Kagaku Kogyo Co., Ltd.)
・ Methyl methacrylate, copolymer of glycidyl methacrylate and styrene (methyl methacrylate / glycidyl methacrylate / styrene (molar ratio) = 24/7/69 “ARUFON UG-4040” manufactured by Toa Gosei Co., Ltd.)

(5) Black colorant, carbon black (Mitsubishi Chemical Corporation, “# 45B”)
・ Nigrosine (Orient Chemical Co., Ltd., “PC-0850”)

(6) Core-shell type acrylic polymer Core-shell type polymer having a rubber layer as an inner layer and having an acrylic polymer grafted on an outer layer ("Metbrene C-223A" manufactured by Mitsubishi Rayon Co., Ltd.)

(7) Monocarbodiimide compound N, N′-di-2,6-diisopropylphenylcarbodiimide (Rhein Chemie, “Stavaxol I”)

(8) “LA-1” (polyisocyanate group content: 1 to 3%) manufactured by Nisshinbo Co., Ltd.

<Examples 1 to 17>
Each raw material was supplied to a twin screw extruder (“TEM-37BS” manufactured by Toshiba Machine Co., Ltd.) at the ratio shown in Table 1, and melt kneading extrusion was performed at a processing temperature of 260 ° C. The raw materials were all mixed in advance and supplied to the hopper of the extruder. Then, the discharged resin composition was cut into pellets.

  Furthermore, after drying the obtained resin composition (in the form of pellets) at 80 ° C. for 5 hours using a hot air dryer, an injection molding machine (“IS-80G type” manufactured by Toshiba Machine Co., Ltd.) is used. The test piece of the size suitable for various performance evaluation was obtained. When obtaining any of the test pieces, it was melted at a cylinder set temperature (injection temperature) of 230 ° C., filled in a mold of 60 ° C. (mold temperature) with an injection pressure of 120 MPa and an injection time of 15 seconds, and for 30 seconds. After holding, it was taken out.

<Comparative Examples 1-8>
Except that each raw material was supplied to a twin screw extruder (“TEM-37BS” manufactured by Toshiba Machine Co., Ltd.) at the ratio shown in Table 2, and melt kneading extrusion was performed at a processing temperature of 260 ° C., as in Example 1. Thus, a resin composition was obtained. And various test pieces were obtained like Example 1 using the obtained resin composition.

  Tables 1 and 2 collectively show the results of various physical property evaluations on the resin compositions and molded bodies obtained in Examples and Comparative Examples.

  The resin compositions obtained in Examples 1 to 17 were excellent in heat resistance, impact resistance and molding processability, and remarkably excellent in jet black feeling.

  The resin composition obtained in Example 2 did not contain a core-shell type acrylic polymer, and therefore left room for improvement in impact resistance, but was sufficiently durable for practical use. .

  The resin compositions obtained in Examples 10 to 15 in which the carbodiimide compound was blended had excellent strength retention even after 1000 h of wet heat treatment, and were excellent in wet heat resistance. Moreover, from the comparison between Example 12 and Example 13, when the total amount of the carbodiimide compound is compared in the same composition, the combination of monocarbodiimide and polyvalent carbodiimide at a predetermined ratio is more than when each is used alone. It is clear that the heat and heat resistance is excellent.

  The resin composition obtained in Example 10 had a room for improvement in impact resistance and heat resistance because the content of the polycarbonate resin was less than the preferred range of the present invention. Could withstand.

  The resin composition obtained in Example 16 had room for improvement in impact resistance because the content of the acrylonitrile-styrene-butadiene copolymer was less than the preferred range. Could withstand.

  The resin composition obtained in Example 17 had a room for improvement in heat resistance because the content of the acrylonitrile-styrene-butadiene copolymer was larger than the preferred range, but was sufficiently practically used. It was tolerable.

  The resin composition obtained in Comparative Example 1 had an excessive amount of polycarbonate resin and an excessive content of polylactic acid resin. Therefore, it was inferior to heat resistance and impact resistance.

  The resin composition obtained in Comparative Example 2 contained too little polylactic acid resin and too much polycarbonate resin. Therefore, it has no effect of reducing the environmental load, and the MFR value is low.

  The resin composition obtained in Comparative Example 3 had an insufficient acrylic / styrene copolymer content. Therefore, compared with Example 1 where the content of the black colorant is the same, the black appearance was significantly inferior. Thereby, in this invention, in order to obtain the resin composition which has the outstanding jet black feeling, without adding a large amount of black colorants, it is possible to use an acrylic / styrene copolymer and a black colorant in combination. Obviously it is essential.

  The resin composition obtained in Comparative Example 4 had an excessive content of acrylic / styrene copolymer. As a result, the impact resistance was significantly inferior.

  The resin composition obtained in Comparative Example 5 was inferior in impact resistance because the content of acrylonitrile-styrene-butadiene copolymer was too small.

  The resin composition obtained in Comparative Example 6 had an excessive content of polycarbonate resin and an excessive content of acrylonitrile-styrene-butadiene copolymer. Therefore, it became inferior to impact resistance and heat resistance.

  The resin composition obtained in Comparative Example 7 was significantly inferior in black appearance because the content of the black colorant was excessive.

  The resin composition obtained in Comparative Example 8 was inferior in impact resistance because the content of the black colorant was excessive.

Claims (5)

  A resin composition containing a polylactic acid resin (A), a polycarbonate resin (B), an acrylonitrile-styrene-butadiene copolymer resin (C), an acrylic / styrene copolymer (D), and a black colorant (E). The content of the polylactic acid resin (A) in the resin composition is 20 to 50% by mass, the content of the polycarbonate resin (B) is 30 to 60% by mass, and the acrylonitrile-styrene-butadiene copolymer resin (C). Is 2 to 20 mass%, the acrylic / styrene copolymer (D) is 0.5 to 10 mass%, and the black colorant (E) is 0.1 to 5 mass%. A black resin composition characterized by being.   Furthermore, 1-15 mass% core-shell type acrylic polymer (F) is contained, The black-type resin composition of Claim 1 characterized by the above-mentioned.   The black resin composition according to claim 1 or 2, wherein the black colorant (E) is carbon black and / or nigrosine.   Furthermore, 0.1-5 mass% carbodiimide compound (G) is contained, The black-type resin composition in any one of Claims 1-3 characterized by the above-mentioned.   The molded object formed by shape | molding the black resin composition in any one of Claims 1-4.