JP2007191695A - Resin composition and molded article comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a resin composition having low environmental burden, having excellent strength, impact resistance, heat resistance and moldability and processability and capable of reducing CO<SB>2</SB>discharge amount during production. <P>SOLUTION: The resin composition comprises (A) a styrene-based resin, (B) a graft polymer, (C) an aliphatic polyester and (D) an impact resistance-improving agent. The resin composition comprises, preferably, 30-60 wt.% styrene-based resin (A), 10-50 wt.% graft polymer (B), 60-10 wt.% aliphatic polyester (C) and 2-20 wt.% impact resistance-improving agent (D) based on total amount of components (A), (B), (C) and (D). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resin composition that is excellent in strength, impact resistance, heat resistance, and molding processability and has a low environmental load, and a molded article comprising the same.

Styrenic resins are used in a wide range of fields such as electrical and electronic parts, automobiles, general merchandise, and various applications due to their excellent mechanical properties, moldability, and appearance. However, styrene-based resins are made from petroleum resources, and CO ₂ emissions into the atmosphere during production and environmental impacts during disposal have been viewed as problems in recent years, and materials containing non-petroleum resources are required as environmentally low-load materials. ing.

  Recently, biodegradable polymers that are decomposed in the natural environment by the action of microorganisms existing in the soil and water have attracted attention from the viewpoint of global environmental conservation, and various biodegradable polymers have been developed. Among them, polylactic acid is relatively inexpensive and has a high melting point of about 170 ° C., and is expected as a biodegradable polymer that can be melt-molded. In addition, lactic acid, which is a monomer, has recently been manufactured at low cost by fermentation using microorganisms, and it has become possible to produce polylactic acid at a much lower cost, so that not only as a biodegradable polymer, Use as a general-purpose polymer has also been studied. However, on the other hand, it has physical defects such as low impact resistance and low flexibility, and an improvement is desired.

  Therefore, a method of mixing polylactic acid and a thermoplastic resin such as polystyrene, polyethylene, polyethylene terephthalate, or polypropylene as an environmentally low load material (Patent Document 1) is disclosed. When mixed by this method, it becomes an environmentally low load material, but in order to use any of them as a general-purpose resin, it was necessary to improve mechanical properties. Although this article mentions a rubber component as an impact modifier, preferred embodiments and examples are not exemplified, and the addition of the styrenic resin of the present invention improves the heat resistance, and further the graft polymer. There is no disclosure of improving impact resistance by addition.

  Furthermore, a biodegradable resin composition (Patent Document 2) containing polylactic acid and an amorphous resin having a glass transition temperature higher than the glass transition temperature of polylactic acid has been disclosed. Further improvements were needed in terms of improving both.

In addition, an aliphatic polyester resin composition containing an aliphatic polyester and a multilayer structure polymer (Patent Document 3), and a graft obtained by graft polymerization of a vinyl monomer to a polylactic acid polymer and a rubber polymer Although a resin composition (Patent Document 4) made of a copolymer is disclosed, these resin compositions do not contain a styrenic resin, and the resulting resin composition is heat resistant. There was a problem, and further improvement was required when used as a general-purpose polymer.
JP-T 6-504799 (page 53) Japanese Patent Laying-Open No. 2005-60637 (second page) JP 2003-286396 A (page 2) JP 2004-285258 A (2nd page)

The present invention has been achieved as a result of studying the solution of the above-described problems in the prior art as an object, and the object thereof is to have excellent strength, impact resistance, heat resistance and moldability. Another object of the present invention is to provide an environmentally low load resin composition capable of greatly reducing CO ₂ emission during production and a molded product comprising the same.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a resin composition containing a styrene resin, a graft polymer, an aliphatic polyester, and an impact resistance improver. .

That is, the present invention
(1) (A) a styrene resin, (B) a graft polymer, (C) an aliphatic polyester, (D) a resin composition comprising an impact resistance improver,
(2) (A) Styrenic resin, (B) Graft polymer, (C) Aliphatic polyester, and (D) Impact resistance modifier is 30 to 30 60% by weight, (B) the added amount of the graft polymer is 10 to 50% by weight, (C) the added amount of the aliphatic polyester is 60 to 10% by weight, and (D) the added amount of the impact modifier is 2 to 20%. The resin composition according to (1), wherein the resin composition is wt%,
(3) (A) Styrenic resin is (a) 0 to 99% by weight of unsaturated carboxylic acid alkyl ester unit, (b) 1 to 100% by weight of aromatic vinyl unit, (c) vinyl cyanide unit Any one of (1) to (2), characterized in that 0 to 50% by weight and (d) 0 to 99% by weight of other vinyl units copolymerizable therewith are copolymerized styrene resins The resin composition according to
(4) (B) Graft polymer is (r) 10 to 80% by weight of rubbery polymer, (a) 20 to 90% by weight of unsaturated carboxylic acid alkyl ester unit, (b) aromatic vinyl unit 0 to 70% by weight, (c) 0 to 50% by weight of vinyl cyanide units, and (d) 0 to 70% by weight of other vinyl units copolymerizable with these are graft polymers. The resin composition according to any one of (1) to (3),
(5) The resin composition according to any one of (1) to (4), wherein (C) the aliphatic polyester has polylactic acid as a main component,
(6) (D) The impact modifier is at least one selected from a polymer containing an acrylic unit, a polymer containing a unit having an acid anhydride group and / or a glycidyl group, and polyurethane rubber. The resin composition according to any one of (1) to (5),
(7) (B) Graft copolymer is (r) 10-80% by weight of butadiene-based polymer, (a) 20-90% by weight of unsaturated carboxylic acid alkyl ester unit, (b) aromatic vinyl-based A graft polymer in which 0 to 70% by weight of units, (c) 0 to 50% by weight of vinyl cyanide units, and (d) 0 to 70% by weight of other vinyl units copolymerizable therewith are graft-polymerized. And (D) the impact modifier is at least one selected from a polymer containing an acrylic acid unit, a polymer containing a unit having an acid anhydride group and / or a glycidyl group, and polyurethane rubber. The resin composition according to any one of (1) to (6),
(8) The resin composition according to any one of (1) to (7), further comprising (E1) a polyvalent carboxylic acid anhydride and (E2) at least one selected from polyvalent carboxylic acids.
(9) (E1) The resin composition according to (8), wherein the polyvalent carboxylic acid anhydride is either maleic acid anhydride or succinic acid anhydride,
It is. further,
(10) A molded product obtained by molding the resin composition according to any one of (1) to (9),
It is.

  The resin composition of the present invention and its molded product are preferably a resin composition comprising (A) a styrene resin, (B) a graft polymer, (C) an aliphatic polyester, and (D) an impact resistance improver. In an aspect, a resin composition comprising at least one selected from a polyvalent carboxylic acid anhydride or a polyvalent carboxylic acid, having excellent strength, impact resistance, heat resistance, and moldability A resin composition having a low environmental load is obtained.

  The resin composition of the present invention will be specifically described below.

  (A) Styrenic resin used in the present invention includes styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, pt-butylstyrene, and the like. (B) It can be obtained by subjecting an aromatic vinyl monomer and a monomer copolymerizable therewith to known bulk polymerization, bulk suspension polymerization, solution polymerization, precipitation polymerization or emulsion polymerization.

  The (A) styrene resin in the present invention does not include (r) a rubbery polymer obtained by graft polymerization of (b) an aromatic vinyl unit or the like. (R) A rubber polymer obtained by graft polymerization of (b) an aromatic vinyl unit or the like is included in (B) the graft polymer described later.

  Specifically, (b) 0 to 99% by weight of unsaturated carboxylic acid alkyl ester unit, (c) 0 to 50% by weight of vinyl cyanide unit, based on 1 to 100% by weight of aromatic vinyl unit. %, And (d) a vinyl copolymer obtained by copolymerizing 0 to 99% by weight of other vinyl units copolymerizable therewith.

  The (a) unsaturated carboxylic acid alkyl ester monomer used for the (A) styrene resin in the present invention is not particularly limited, but an acrylic ester having a C 1-6 alkyl group or substituted alkyl group and Methacrylic acid esters are preferred.

  Specific examples of (a) unsaturated carboxylic acid alkyl ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and n-butyl (meth) acrylate. T-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2- (meth) acrylic acid 2- Hydroxyethyl, 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate and 2,3,4,5-tetrahydroxypentyl (meth) acrylate Among them, methyl methacrylate is most preferably used. These can be used alone or in combination of two or more thereof.

  The (c) vinyl cyanide monomer used in the (A) styrene resin in the present invention is not particularly limited, and specific examples include acrylonitrile, methacrylonitrile, ethacrylonitrile, etc., among which acrylonitrile. Is preferably used. These can use 1 type (s) or 2 or more types.

  Examples of other vinyl monomers copolymerizable with (A) styrene resins in the present invention include (a) unsaturated carboxylic acid alkyl ester monomers, and (b) aromatic vinyls. There is no particular limitation as long as it is copolymerizable with a monomer based on (c) vinyl cyanide, and specific examples include N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, etc. Maleimide monomer, acrylic acid, methacrylic acid, maleic acid, maleic acid monoethyl ester, maleic anhydride, phthalic acid, itaconic acid and other vinyl monomers having a carboxyl group or an anhydrous carboxyl group, 3-hydroxy -1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2-butene, trans-4-hydroxy-2 Vinyl having a hydroxyl group such as butene, 3-hydroxy-2-methyl-1-propene, cis-5-hydroxy-2-pentene, trans-5-hydroxy-2-pentene, 4,4-dihydroxy-2-butene Monomers, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, allyl glycidyl ether, vinyl monomers having an epoxy group such as styrene-p-glycidyl ether and p-glycidyl styrene, acrylamide, Methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propylmethacrylamide, aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, Vinyl-based monomer having amino groups and derivatives thereof such as phenylaminoethyl acrylate, cyclohexylaminoethyl methacrylate, N-vinyldiethylamine, N-acetylvinylamine, allylamine, methallylamine, N-methylallylamine, p-aminostyrene , Vinyl monomers having an oxazoline group such as 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acryloyl-oxazoline and 2-styryl-oxazoline, etc., and these are one or more Can be used.

  In the present invention, as the (A) styrenic resin, one or more kinds can be used, and in terms of excellent impact resistance, heat resistance, surface appearance, and colorability, for example, It is preferable to use together a styrene resin copolymerized with methyl methacrylate and a styrene resin not copolymerized with methyl methacrylate.

  (A) Although there is no restriction | limiting in the characteristic of a styrene resin, The thing whose intrinsic viscosity [(eta)] measured at 30 degreeC using the methyl ethyl ketone solvent is 0.20-2.00 dl / g is preferable, and 0 More preferable is a range of 25 to 1.50 dl / g, and particularly preferable is a range of 0.26 to 0.50 because a resin composition having excellent impact resistance and molding processability can be obtained. .

  (A) Although there is no restriction | limiting in the molecular weight of a styrene resin, The weight average molecular weights measured by the gel permeation chromatography (GPC) using the tetrahydrofuran solvent are the range of 10,000-400,000, especially 50,000-15. Those in the range of 10,000 are preferable because a resin composition having excellent impact resistance and molding processability can be obtained.

  The (B) graft polymer used in the present invention is a monomer mixture obtained by adding a vinyl monomer and a monomer copolymerizable therewith in the presence of (r) a rubbery polymer. It is obtained by subjecting to bulk polymerization, bulk suspension polymerization, solution polymerization, precipitation polymerization or emulsion polymerization.

  The (B) graft polymer is a copolymer having a structure in which a copolymer containing a vinyl monomer is grafted to (r) a rubbery polymer, and a copolymer containing a vinyl monomer. (R) includes a structure in which the rubbery polymer is not grafted.

  Specifically, (r) in the presence of 10 to 80% by weight of rubbery polymer, (a) 20 to 90% by weight of unsaturated carboxylic acid alkyl ester monomer, (b) aromatic vinyl unit 0 Vinyl graft copolymer obtained by copolymerizing ˜70 wt%, (c) 0 to 50 wt% of vinyl cyanide units, and (d) 0 to 70 wt% of other vinyl units copolymerizable therewith. Polymers are preferred.

  The (r) rubbery polymer is not particularly limited, but those having a glass transition temperature of 0 ° C. or lower are suitable, and diene rubber, acrylic rubber, ethylene rubber, and the like can be used. Specific examples of these rubbery polymers include polybutadiene, styrene-butadiene copolymer, block copolymer of styrene-butadiene, acrylonitrile-butadiene copolymer, butyl acrylate-butadiene copolymer, polyisoprene, butadiene- Methyl methacrylate copolymer, butyl acrylate-methyl methacrylate copolymer, butadiene-ethyl acrylate copolymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-isoprene copolymer And ethylene-methyl acrylate copolymer. Among these rubbery polymers, polybutadiene, styrene-butadiene copolymer, block copolymer of styrene-butadiene and acrylonitrile-butadiene copolymer are particularly preferably used from the viewpoint of impact resistance, and one kind or It can be used in a mixture of two or more.

  The weight average particle diameter of the (r) rubbery polymer constituting the (B) graft polymer in the present invention is not particularly limited, but is in the range of 0.05 to 1.0 μm, particularly 0.1 to 0.5 μm. It is preferable that By setting the weight average particle diameter of the rubbery polymer in the range of 0.05 μm to 1.0 μm, excellent impact resistance can be exhibited. Further, as the rubbery polymer, one or more kinds can be used, and it is preferable to use two or more kinds of rubbery polymers having different weight average particle diameters in terms of impact resistance and fluidity. For example, a so-called bimodal rubber using a rubber polymer having a small weight average particle diameter and a rubber polymer having a large weight average particle diameter may be used.

  In addition, the weight average particle diameter of (r) rubber-like polymer is sodium alginate as described in "Rubber Age, Vol. 88, p.484-490, (1960), by E. Schmidt, PH Biddison". Method, that is, by using the fact that the polybutadiene particle size to be creamed differs depending on the concentration of sodium alginate, the particle size of 50% cumulative weight fraction is obtained from the weight proportion of cream and the cumulative weight fraction of sodium alginate concentration. Can be measured.

  (R) The gel content of the rubbery polymer is not particularly limited, but is preferably 40 to 99% by weight and more preferably 60 to 95% by weight in terms of impact resistance and heat resistance. 72 to 88% by weight is particularly preferable. Here, the gel content can be measured by a method in which toluene is extracted at room temperature for 24 hours to obtain the insoluble content.

  The (a) unsaturated carboxylic acid alkyl ester monomer used in the graft polymer (B) in the present invention is not particularly limited, but an acrylate ester having an alkyl group having 1 to 6 carbon atoms or a substituted alkyl group and Methacrylic acid esters are preferred.

  Specific examples of (a) unsaturated carboxylic acid alkyl ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and n-butyl (meth) acrylate. T-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2- (meth) acrylic acid 2- Hydroxyethyl, 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate and 2,3,4,5-tetrahydroxypentyl (meth) acrylate Among them, methyl methacrylate is most preferably used. These can be used alone or in combination of two or more thereof.

  The (b) aromatic vinyl monomer used in the graft polymer (B) in the present invention is not particularly limited, and specific examples include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene. , O-ethyl styrene, p-ethyl styrene, pt-butyl styrene and the like, among which styrene and α-methyl styrene are preferably used. These can use 1 type (s) or 2 or more types.

  The (c) vinyl cyanide monomer used in the graft polymer (B) in the present invention is not particularly limited, and specific examples include acrylonitrile, methacrylonitrile, ethacrylonitrile, etc., among which acrylonitrile. Is preferably used. These can use 1 type (s) or 2 or more types.

  (D) Other vinyl monomers copolymerizable with these used in the graft polymer (B) in the present invention include (a) unsaturated carboxylic acid alkyl ester monomers, and (b) aromatic vinyl. There is no particular limitation as long as it can be copolymerized with a monomer based on (c) vinyl cyanide, but specific examples include N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, and N-phenyl. Maleimide monomers such as maleimide, vinyl monomers having a carboxyl group or an anhydride carboxyl group such as acrylic acid, methacrylic acid, maleic acid, maleic acid monoethyl ester, maleic anhydride, phthalic acid and itaconic acid, 3 -Hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2-butene, trans-4-hydroxy Hydroxyl groups such as 2-butene, 3-hydroxy-2-methyl-1-propene, cis-5-hydroxy-2-pentene, trans-5-hydroxy-2-pentene, and 4,4-dihydroxy-2-butene; Vinyl monomers having glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, allyl glycidyl ether, vinyl monomers having an epoxy group such as styrene-p-glycidyl ether and p-glycidyl styrene, Acrylamide, methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propyl methacrylamide, aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate Vinyl-based monomer having amino groups and derivatives thereof such as phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, N-vinyldiethylamine, N-acetylvinylamine, allylamine, methallylamine, N-methylallylamine, p-aminostyrene , Vinyl monomers having an oxazoline group such as 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acryloyl-oxazoline and 2-styryl-oxazoline, etc., and these are one or more Can be used.

  In the present invention, (B) the graft polymer comprises (r) an unsaturated carboxylic acid alkyl ester monomer in the presence of (r) 10 to 80% by weight, more preferably 30 to 70% by weight of a rubbery polymer. Is 20 to 90% by weight, more preferably 30 to 70% by weight, (b) aromatic vinyl monomer is 0 to 70% by weight, more preferably 0 to 50% by weight, and (c) vinyl cyanide monomer. 0 to 50% by weight of the monomer, more preferably 0 to 30% by weight, (d) 0 to 70% by weight of other vinyl monomers copolymerizable with these, more preferably 0 to 50% by weight. Obtained by copolymerization. Even if the ratio of the rubbery polymer is less than the above range or exceeds the above range, the impact strength and the surface appearance may be deteriorated.

The (B) graft polymer contained an ungrafted copolymer in addition to the graft copolymer having a structure in which a monomer or a monomer mixture was grafted to the (r) rubbery polymer. Is. The graft ratio of the graft polymer is not particularly limited, but in order to obtain a resin composition having excellent balance between impact resistance and gloss, it is in the range of 10 to 100% by weight, particularly 20 to 80% by weight. Is preferred. Here, the graft ratio is a value calculated by the following equation.
Graft rate (%) = [<Amount of vinyl copolymer graft-polymerized to rubbery polymer> / <Rubber content of graft copolymer>] × 100

  The characteristics of the ungrafted copolymer are not particularly limited, but the intrinsic viscosity [η] (measured at 30 ° C.) of the methyl ethyl ketone-soluble component is 0.10 to 1.00 dl / g, particularly 0.20 to 0.00. A range of 80 dl / g is a preferable condition for obtaining a resin composition having excellent impact resistance.

  (B) The graft polymer can be obtained by a known polymerization method. For example, it can be obtained by a method of emulsion polymerization by continuously supplying a mixture of a monomer and a chain transfer agent and a solution of a radical generator dissolved in an emulsifier to a polymerization vessel in the presence of a rubbery polymer latex. .

  The (C) aliphatic polyester of the present invention is not particularly limited, and is a polymer mainly composed of an aliphatic hydroxycarboxylic acid, and mainly composed of an aliphatic polycarboxylic acid and an aliphatic polyhydric alcohol. And the like. Specifically, polymers having aliphatic hydroxycarboxylic acid as a main component include polyglycolic acid, polylactic acid, poly-3-hydroxybutyric acid, poly-4-hydroxybutyric acid, poly-4-hydroxyvaleric acid, poly-3- Hydroxyhexanoic acid or polycaprolactone, etc., and examples of the polymer mainly composed of aliphatic polycarboxylic acid and aliphatic polyhydric alcohol include polyethylene adipate, polyethylene succinate, polybutylene adipate, or polybutylene succinate. Is mentioned. These aliphatic polyesters can be used alone or in combination of two or more. Among these aliphatic polyesters, a polymer containing hydroxycarboxylic acid as a main constituent is preferable, and polylactic acid is particularly preferably used.

  The polylactic acid is a polymer mainly composed of L-lactic acid and / or D-lactic acid, but may contain other copolymer components other than lactic acid as long as the object of the present invention is not impaired. .

  Examples of such other copolymer component units include polyvalent carboxylic acids, polyhydric alcohols, hydroxycarboxylic acids, lactones, and the like. Specifically, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid , Azelaic acid, sebacic acid, dodecanedioic acid, fumaric acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium sulfoisophthalic acid Polyhydric carboxylic acids such as ethylene glycol, propylene glycol, butanediol, heptanediol, hexanediol, octanediol, nonanediol, decanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, glycerin, trimethyl Propanediol, pentaerythritol, bisphenol A, aromatic polyhydric alcohols obtained by addition reaction of ethylene oxide with bisphenol, polyhydric alcohols such as diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, glycolic acid, Hydroxycarboxylic acids such as 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid, hydroxybenzoic acid, glycolide, ε-caprolactone glycolide, ε-caprolactone, β-propiolactone, δ- Lactones such as butyrolactone, β- or γ-butyrolactone, pivalolactone, and δ-valerolactone can be used. These copolymer components can be used alone or in combination of two or more.

  In order to obtain high heat resistance with polylactic acid, it is preferable that the optical purity of the lactic acid component is high. Among the total lactic acid components, L-form or D-form is preferably contained at 80 mol% or more, and more preferably 90 mol%. It is preferably contained in an amount of 95 mol% or more.

  Moreover, as (C) aliphatic polyester of this invention, it is preferable to use a polylactic acid stereocomplex from the point of heat resistance and a moldability. As a method of forming a polylactic acid stereocomplex, for example, L-form is 90 mol% or more, preferably 95 mol% or more, more preferably 98 mol% or more poly-L-lactic acid and D-form is 90 mol% or more, Preferably, 95 mol% or more, more preferably 98 mol% or more of poly-D-lactic acid is mixed by melt kneading or solution kneading. Another method is a method in which poly-L-lactic acid and poly-D-lactic acid are used as a block copolymer, so that a polylactic acid stereocomplex can be easily formed. A method using L-lactic acid and poly-D-lactic acid as a block copolymer is preferred.

  When the (C) aliphatic polyester used in the present invention is a polylactic acid resin, the polylactic acid resin may be used alone. For example, poly-L-lactic acid or poly-D- having a high L-form or D-form content. A block copolymer of poly-L-lactic acid and poly-D-lactic acid forming lactic acid and a polylactic acid stereocomplex can also be used in combination.

  (C) As a manufacturing method of aliphatic polyester, a known polymerization method can be used. In particular, for polylactic acid, a direct polymerization method from lactic acid, a ring-opening polymerization method via lactide, or the like can be employed.

  (C) The molecular weight or molecular weight distribution of the aliphatic polyester is not particularly limited as long as it can be substantially molded, and the weight average molecular weight is preferably 10,000 or more, more preferably 40,000 or more. More preferably, it is 80,000 or more, and particularly preferably 160,000 or more. The weight average molecular weight herein is a weight average molecular weight in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography (GPC) using hexafluoroisopropanol as a solvent.

  (C) Melting | fusing point of aliphatic polyester is not specifically limited, It is preferable that it is 90 degreeC or more, and it is more preferable that it is 150 degreeC or more.

  In the present invention, the melt viscosity ratio ((A) / (C)) of (A) styrene resin and (C) aliphatic polyester is 0.1 to 0.1 in that a resin composition having excellent heat resistance is obtained. A range of 10 is preferable.

  In the present invention, when any one of (A) a styrenic resin and (C) an aliphatic polyester forms a phase structure that forms a dispersed phase, a resin composition having excellent impact resistance and heat resistance can be obtained. The average particle size of the dispersed phase is preferably in the range of 10 nm to 100 μm, more preferably in the range of 50 nm to 10 μm, and still more preferably in the range of 100 nm to 1000 nm. The average particle diameter here is the number average value obtained by measuring the longest particle system of each dispersed phase in the phase structure when the cross section of the resin composition of the present invention is observed with an electron microscope. Average particle size.

  The (D) impact resistance improver used in the present invention is not particularly limited as long as it can be used to improve the impact resistance of a thermoplastic resin, but is a polymer that exhibits rubber elasticity at room temperature. ) A polymer other than a graft polymer.

  That is, specific examples of the impact modifier include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-nonconjugated diene copolymer, ethylene-butene-1 copolymer, various acrylic rubbers, ethylene- Acrylic acid copolymer and its alkali metal salt (so-called ionomer), ethylene-glycidyl (meth) acrylate copolymer, ethylene-alkyl acrylate copolymer (for example, ethylene-ethyl acrylate copolymer, ethylene-acrylic) Acid butyl copolymer), acid-modified ethylene-propylene copolymer, diene rubber (eg polybutadiene, polyisoprene, polychloroprene), copolymer of diene and vinyl monomer (eg styrene-butadiene random copolymer, styrene) -Butadiene block Polymer, styrene-butadiene-styrene block copolymer, styrene-isoprene random copolymer, styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer), polyisobutylene, isobutylene and butadiene or isoprene. Examples thereof include copolymers, natural rubber, thiocol rubber, polysulfide rubber, acrylic rubber, silicone rubber, polyurethane rubber, polyether rubber, epichlorohydrin rubber, polyester elastomer, and polyamide elastomer.

  Furthermore, those having various degrees of crosslinking, those having various microstructures, for example, those having a cis structure, a trans structure, etc., those having a vinyl group, or those having various average particle diameters (in the resin composition) Alternatively, a so-called core-shell type multi-layered polymer composed of a core layer and one or more shell layers covering the core layer, and the adjacent layers composed of different types of polymers can also be used.

  As the impact resistance improver, a polymer containing an acrylic unit and a polymer containing a unit having an acid anhydride group and / or a glycidyl group are preferable. Preferable examples of the acrylic unit here include methyl methacrylate unit, methyl acrylate unit, ethyl acrylate unit and butyl acrylate unit, methacrylic acid unit, acrylic acid unit, and metal salt unit of acrylic acid. Preferable examples of the unit having an acid anhydride group or glycidyl group include a maleic anhydride unit and a glycidyl methacrylate unit.

  Another preferred impact modifier is polyurethane rubber. Here, the polyurethane rubber is a general term for all elastic bodies having a urethane bond, and includes a thermoplastic polyurethane elastomer and a crosslinked polyurethane rubber obtained by crosslinking it. Of these, thermoplastic polyurethane elastomers are preferred. The thermoplastic polyurethane elastomer has at least a hard segment composed of a diisocyanate and a short chain polyol and a soft segment composed of a diisocyanate and a long chain polyol. As the diisocyanate compound constituting the thermoplastic polyurethane elastomer, diphenylmethane diisocyanate, 2,4- and 2,6-tolylene diisocyanate, m- and p-phenylene diisocyanate, hexamethylene diisocyanate and the like are preferably used. As the short-chain polyol component, 1,2-ethanediol, 1,2-propanediol, 1,4-butanediol, butenediol, 1,6-hexanediol, 1,10-decamethylenediol and the like are preferably used. . As the long-chain polyol as the soft segment, polyalkylene adipate, polyalkylene ether and the like are preferable, and polyethylene-butylene adipate, polybutylene adipate, polynonanediol adipate, polytetramethylene glycol and the like are more preferable. Each component can be suitably used as a mixture of one kind or two or more kinds.

  The glass transition temperature of the impact resistance improver is preferably −20 ° C. or lower, and more preferably −30 ° C. or lower.

  In the present invention, it is preferable to blend at least one selected from (E1) a polyvalent carboxylic acid anhydride and (E2) a polyvalent carboxylic acid. (E1) The polycarboxylic acid anhydride is a dicarboxylic acid anhydride. (E2) The polycarboxylic acid (E2) is more preferably a dicarboxylic acid.

  In the present invention, (E1) dicarboxylic acid anhydride is a compound having a structure in which water molecules are eliminated in the molecule from dicarboxylic acid. For example, maleic acid anhydride, itaconic acid anhydride, citraconic acid Anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, 1-cyclohexene-1,2-dicarboxylic acid anhydride, cis-4-cyclohexene-1,2-dicarboxylic acid anhydride, succinic acid anhydride, adipine Acid anhydrides, cyclohexanedicarboxylic acid anhydrides, phthalic acid anhydrides, etc. are mentioned, and in terms of impact resistance, heat resistance, and moldability, either maleic acid anhydride or succinic acid anhydride is preferable. In terms of impact resistance and heat resistance, maleic anhydride is more preferable. In the resin composition of the present invention, (E1) dicarboxylic acid anhydride may exist alone as a compound, and (A) a styrene resin, (B) a graft polymer, (C) a fat. It reacts with any one or more of the group polyester and (D) acrylic resin, and may exist without retaining the structure of the dicarboxylic acid anhydride. In the present invention, by adding (E1) dicarboxylic acid anhydride, the phase structure of (A) styrene resin, (B) graft polymer, (C) aliphatic polyester and (D) acrylic resin is affected. Therefore, it is considered that characteristics such as strength, impact resistance, heat resistance and molding processability are greatly improved.

  In the present invention, (E2) dicarboxylic acid is a compound having two carboxylic acids in the molecule. For example, maleic acid, itaconic acid, citraconic acid, 5-norbornene-2,3-dicarboxylic acid, 1-cyclohexene -1,2-dicarboxylic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, succinic acid, adipic acid, cyclohexanedicarboxylic acid, phthalic acid, etc., impact resistance, heat resistance, molding processability In this case, either maleic acid or succinic acid is preferable, and maleic acid is more preferable in terms of impact resistance and heat resistance. In the resin composition of the present invention, (E2) dicarboxylic acid may exist alone as a compound, and (A) a styrene resin, (B) a graft polymer, (C) an aliphatic polyester. And (D) may react with any one or more of the acrylic resins and may exist without retaining the structure of the dicarboxylic acid. In the present invention, by blending (E2) dicarboxylic acid, the phase structure of (A) styrene resin, (B) graft polymer, (C) aliphatic polyester and (D) acrylic resin is affected. Properties such as strength, impact resistance, heat resistance, and moldability are considered to be greatly improved.

  In the present invention, (E1) dicarboxylic acid anhydride and (E2) dicarboxylic acid may be used alone or in combination of two or more. In the present invention, (D) impact modifier is added to (A) styrene resin, (B) graft polymer, and (C) aliphatic polyester to further improve strength, heat resistance, and impact resistance. As a more preferred embodiment, unexpectedly high strength, heat resistance, impact resistance and heat and humidity resistance can be obtained by adding a small amount of at least one selected from (E1) dicarboxylic acid anhydride and (E2) dicarboxylic acid. Can be improved.

  The mixing ratio of (A) styrenic resin, (B) graft polymer, (C) aliphatic polyester, (D) impact modifier of the resin composition of the present invention is (A) styrenic resin, (B (A) Styrenic resin is preferably 10% by weight or more, more preferably 25 to 70% by weight, particularly preferably based on the total amount of the graft polymer, (C) aliphatic polyester and (D) impact modifier. Is 30 to 60% by weight. The amount of (B) graft polymer added is preferably 5 to 50% by weight, more preferably 7 to 50% by weight, and particularly preferably 10 to 50% by weight. Further, the amount of (C) aliphatic polyester added is preferably less than 85% by weight, more preferably 65 to 10% by weight, and particularly preferably 60 to 10% by weight. (D) The addition amount of the impact resistance improver is preferably 1 to 35% by weight, more preferably 2 to 25% by weight, and particularly preferably 2 to 20% by weight.

  In the present invention, the blending amounts of (E1) dicarboxylic acid anhydride and (E2) dicarboxylic acid are (A) styrene resin, (B) graft polymer, (C) aliphatic polyester, and (D) impact modifier. 0 to 5 parts by weight with respect to 100 parts by weight of the total amount, and preferably 0.05 to 2 parts by weight, more preferably 0.1 to 1 part by weight in terms of impact resistance and heat resistance. More preferably, it is 0.1 to 0.5 part by weight.

  The resin composition of the present invention can be obtained by mixing (A) a styrene resin, (B) a graft polymer, (C) an aliphatic polyester, and (D) an impact resistance improver with the above composition. In the obtained styrene-based resin, (a) an unsaturated carboxylic acid alkyl ester unit is 1 to 90% by weight, preferably 10 to 80% by weight, and (b) an aromatic vinyl unit 0 to the resin component. 0.1 to 80% by weight, preferably 1 to 70% by weight, (c) 0 to 45% by weight of vinyl cyanide units, preferably 0 to 40% by weight, (d) other vinyl systems copolymerizable with these Sufficient impact resistance and heat resistance can be obtained by adjusting the unit to a range of 0 to 85% by weight, preferably 0 to 80% by weight.

  The resin composition according to the present invention is characterized by (A) a styrenic resin, (C) a matrix composed of an aliphatic polyester, (B) a graft polymer dispersed in the matrix, and (D) an impact resistance improver. The (B) graft polymer and (D) impact modifier, which are domains at this time, are present in the range of 10 to 90% of the area ratio present in the (C) aliphatic polyester. It is preferable.

  For example, for a molded product obtained by injection molding, after dying (A) a styrene resin, (B) a graft polymer, and (D) an impact resistance improver by an osmium block dyeing method, an ultrathin section was cut out. By observing the cross section of the sample with a transmission electron microscope at a magnification of 6000, the dispersion form of (B) the graft polymer and (D) the impact resistance improving agent can be confirmed.

  Furthermore, the dispersion form of the (B) graft polymer can be changed by changing the composition of the monomer mixture that is graft-copolymerized to the (r) rubber polymer of the (B) graft polymer. For example, if (a) the unsaturated carboxylic acid alkyl ester in the monomer mixture is increased, the (B) graft polymer is more dispersed in the (C) aliphatic polyester phase, and (a) the unsaturated carboxylic acid alkyl ester. When the ester is reduced, it can be confirmed that (B) the graft polymer has less dispersion in the (C) aliphatic polyester phase and (A) dispersion in the styrene resin phase.

  Here, the area ratio in the cross-sectional photograph in which the (B) graft polymer is present in the (C) aliphatic polyester is in the range of 10 to 90%, preferably 20 to 85%, more preferably 30 to 80%. Range. When the area ratio is not in the range of 10 to 90%, the impact resistance is remarkably lowered, which is not preferable.

  (B) Graft polymer and (D) Impact resistance improver (C) As a method for measuring the area ratio present in the aliphatic polyester, the cross section of the molded product is measured with a transmission electron microscope in the same manner as described above. Was taken. Further expanded by 4 times, (C) the area (X) of the dispersion graft polymer and impact modifier in the aliphatic polyester and (A) the area of the dispersion graft polymer and impact modifier in the styrene resin ( Y) is cut out from the photograph and determined by the weight method, and is determined according to the formula of (X) / ((X) + (Y)).

  In the present invention, it is preferable to further contain a crystal nucleating agent from the viewpoint of improving heat resistance.

  As the crystal nucleating agent used in the present invention, those generally used as polymer crystal nucleating agents can be used without particular limitation, and any of inorganic crystal nucleating agents and organic crystal nucleating agents can be used. .

  Specific examples of inorganic crystal nucleating agents include talc, kaolinite, montmorillonite, mica, synthetic mica, clay, zeolite, silica, graphite, carbon black, zinc oxide, magnesium oxide, calcium oxide, titanium oxide, calcium sulfide, and nitriding. Examples thereof include metal salts of boron, magnesium carbonate, calcium carbonate, barium sulfate, aluminum oxide, neodymium oxide, and phenylphosphonate, and talc, kaolinite, montmorillonite, and synthetic mica are preferable from the viewpoint of a large effect of improving heat resistance. . These may be used alone or in combination of two or more. These inorganic crystal nucleating agents are preferably modified with an organic substance in order to enhance dispersibility in the composition.

  The content of the inorganic crystal nucleating agent is preferably 0.01 to 100 parts by weight, more preferably 0.05 to 50 parts by weight, and more preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the (C) aliphatic polyester. Part is more preferable.

  Specific examples of organic crystal nucleating agents include sodium benzoate, potassium benzoate, lithium benzoate, calcium benzoate, magnesium benzoate, barium benzoate, lithium terephthalate, sodium terephthalate, potassium terephthalate, Calcium oxide, sodium laurate, potassium laurate, sodium myristate, potassium myristate, calcium myristate, sodium octacosanoate, calcium octacosanoate, sodium stearate, potassium stearate, lithium stearate, calcium stearate, magnesium stearate, Barium stearate, sodium montanate, calcium montanate, sodium toluate, sodium salicylate, potassium salicylate, salicylic acid , Metal salts of organic carboxylic acids such as aluminum dibenzoate, potassium dibenzoate, lithium dibenzoate, sodium β-naphthalate, sodium cyclohexanecarboxylate, organic sulfonates such as sodium p-toluenesulfonate, sodium sulfoisophthalate, stearic acid Amide, ethylenebislauric acid amide, palmitic acid amide, hydroxystearic acid amide, erucic acid amide, carboxylic acid amides such as trimesic acid tris (t-butylamide), low density polyethylene, high density polyethylene, polypropylene, polyisopropylene, polybutene Polymers such as poly-4-methylpentene, poly-3-methylbutene-1, polyvinylcycloalkane, polyvinyltrialkylsilane, and high melting point polylactic acid, Sodium salt or potassium salt of a polymer having a carboxyl group such as sodium salt of ethylene-acrylic acid or methacrylic acid copolymer, sodium salt of styrene-maleic anhydride copolymer (so-called ionomer), benzylidene sorbitol and its derivatives, sodium-2, Phosphorus compound metal salts such as 2'-methylenebis (4,6-di-t-butylphenyl) phosphate and sodium 2,2-methylbis (4,6-di-t-butylphenyl) From the viewpoint that the effect of improving the resistance is large, organic carboxylic acid metal salts and carboxylic acid amides are preferred. These may be used alone or in combination of two or more.

  The content of the organic crystal nucleating agent is preferably 0.01 to 30 parts by weight, more preferably 0.05 to 10 parts by weight, and 0.1 to 5 parts by weight with respect to 100 parts by weight of the (C) aliphatic polyester. Part is more preferable.

  In this invention, it is preferable to contain fillers other than an inorganic crystal nucleating agent from a viewpoint that heat resistance improves.

  As fillers other than the inorganic crystal nucleating agent used in the present invention, fibrous, plate-like, granular, and powdery materials that are usually used for reinforcing thermoplastic resins can be used. Specifically, glass fiber, asbestos fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whisker, aluminum borate whisker, magnesium whisker, silicon whisker, wollastonite, sepiolite, asbestos, slag fiber, zonolite , Elastadite, gypsum fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber and boron fiber, etc., inorganic fiber filler, polyester fiber, nylon fiber, acrylic fiber, regenerated cellulose fiber, acetate fiber Organic fiber fillers such as kenaf, ramie, cotton, jute, hemp, sisal, flax, linen, silk, manila hemp, sugar cane, wood pulp, paper waste, waste paper and wool, glass flakes, graphite, metal foil, ceramic beads Sericite, bentonite, dolomite, fine silicic acid, feldspar powder, potassium titanate, shirasu balloon, aluminum silicate, silicon oxide, gypsum, novaculite, include plate-like or particulate filler, such as such as dawsonite and white clay. Among these fillers, inorganic fibrous fillers are preferable, and glass fibers and wollastonite are particularly preferable. Moreover, use of an organic fibrous filler is also preferable, and natural fiber and regenerated fiber are more preferable from the viewpoint of taking advantage of biodegradability of the aliphatic polyester resin. Further, the aspect ratio (average fiber length / average fiber diameter) of the fibrous filler used for blending is preferably 5 or more, more preferably 10 or more, and further preferably 20 or more.

  The filler may be coated or focused with a thermoplastic resin such as an ethylene / vinyl acetate copolymer or a thermosetting resin such as an epoxy resin, or may be a coupling agent such as aminosilane or epoxysilane. It may be processed.

  The content of the filler is preferably 0.1 to 200 parts by weight, more preferably 0.5 to 100 parts by weight with respect to 100 parts by weight of the (C) aliphatic polyester.

  In the present invention, it is preferable to further contain a plasticizer from the viewpoint of improving heat resistance.

  As the plasticizer used in the present invention, those generally used as polymer plasticizers can be used without particular limitation. For example, polyester plasticizer, glycerin plasticizer, polyvalent carboxylic ester plasticizer, polyalkylene Examples include glycol plasticizers and epoxy plasticizers.

  Specific examples of the polyester plasticizer include acid components such as adipic acid, sebacic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, propylene glycol, 1,3-butanediol, 1,4-butane. Examples thereof include polyesters composed of diol components such as diol, 1,6-hexanediol, ethylene glycol and diethylene glycol, and polyesters composed of hydroxycarboxylic acid such as polycaprolactone. These polyesters may be end-capped with a monofunctional carboxylic acid or monofunctional alcohol, or may be end-capped with an epoxy compound or the like.

  Specific examples of the glycerin plasticizer include glycerin monoacetomonolaurate, glycerin diacetomonolaurate, glycerin monoacetomonostearate, glycerin diacetomonooleate, and glycerin monoacetomonomontanate.

  Specific examples of polycarboxylic acid plasticizers include phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, diheptyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, and trimellitic acid. Trimellitic acid esters such as tributyl, trioctyl trimellitic acid, trihexyl trimellitic acid, sebacic acid esters such as diisodecyl adipate, n-octyl-n-decyl adipate adipate, triethyl acetylcitrate, tributyl acetylcitrate, etc. Citrate esters, azelaic acid esters such as di-2-ethylhexyl azelate, sebacic acid esters such as dibutyl sebacate, and di-2-ethylhexyl sebacate.

  Specific examples of the polyalkylene glycol plasticizer include polyethylene glycol, polypropylene glycol, poly (ethylene oxide / propylene oxide) block and / or random copolymer, polytetramethylene glycol, ethylene oxide addition polymer of bisphenols, bisphenols Polyalkylene glycols such as propylene oxide addition polymers, tetrahydrofuran addition polymers of bisphenols, or end-capped compounds such as terminal epoxy-modified compounds, terminal ester-modified compounds, and terminal ether-modified compounds.

  The epoxy plasticizer generally refers to an epoxy triglyceride composed of an alkyl epoxy stearate and soybean oil, but there are also so-called epoxy resins mainly made of bisphenol A and epichlorohydrin. Can be used.

  Specific examples of other plasticizers include benzoic acid esters of aliphatic polyols such as neopentyl glycol dibenzoate, diethylene glycol dibenzoate, triethylene glycol di-2-ethylbutyrate, fatty acid amides such as stearamide, oleic acid Examples thereof include aliphatic carboxylic acid esters such as butyl, oxyacid esters such as methyl acetylricinoleate and butyl acetylricinoleate, pentaerythritol, various sorbitols, polyacrylic acid esters, silicone oils, and paraffins.

  Among the plasticizers used in the present invention, at least one selected from polyester plasticizers and polyalkylene glycol plasticizers is particularly preferable. The plasticizer used in the present invention may be used alone or in combination of two or more.

  Moreover, the range of 0.01-30 weight part is preferable with respect to 100 weight part of (C) aliphatic polyester, and, as for content of a plasticizer, the range of 0.1-20 weight part is more preferable, 0.5 The range of 10 to 10 parts by weight is more preferable.

  In the present invention, each of the crystal nucleating agent and the plasticizer may be used alone, but it is preferable to use both in combination.

  In the present invention, it is preferable to further contain a carboxyl group-reactive end-blocking agent from the viewpoint of improving heat resistance and durability by inhibiting hydrolysis.

  The carboxyl group-reactive end-blocking agent used in the present invention is not particularly limited as long as it is a compound that can block the carboxyl end group of the polymer, and those used as the carboxyl-terminal blocking agent of the polymer are used. be able to. In the present invention, the carboxyl group-reactive end-blocking agent (C) not only blocks the end of the aliphatic polyester, but also includes carboxyl groups of acidic low-molecular compounds such as lactic acid and formic acid generated by thermal decomposition or hydrolysis. Can be blocked. Further, the end-capping agent is more preferably a compound that can also block the hydroxyl end where an acidic low molecular weight compound is generated by thermal decomposition.

  As such a carboxyl group-reactive end-blocking agent, it is preferable to use at least one compound selected from an epoxy compound, an oxazoline compound, an oxazine compound, a carbodiimide compound, and an isocyanate compound, and in particular, an epoxy compound and / or a carbodiimide. Compounds are preferred.

  The content of the carboxyl group-reactive end-blocking agent is preferably in the range of 0.01 to 10 parts by weight and more preferably in the range of 0.05 to 5 parts by weight with respect to 100 parts by weight of the (C) aliphatic polyester.

  The addition time of the carboxyl group-reactive end-blocking agent is not particularly limited, but it can be improved not only in heat resistance but also in mechanical properties and durability. It is preferable to knead with other materials.

  In the present invention, stabilizers (antioxidants, ultraviolet absorbers, weathering agents, etc.), lubricants, mold release agents, flame retardants, colorants including dyes or pigments, antistatic agents, as long as the object of the present invention is not impaired. A foaming agent or the like can be added.

  In the present invention, other thermoplastic resins (for example, acrylic resins, polyamide resins, polyphenylene sulfide resins, polyether ether ketone resins, polyester resins other than aliphatic polyesters, polysulfone resins, Ether sulfone resin, aromatic and aliphatic polycarbonate resin, polyarylate resin, polyphenylene oxide resin, polyacetal resin, polyimide resin, polyetherimide resin, aromatic and aliphatic polyketone resin, fluororesin, polyvinyl chloride resin, polychlorinated resin Vinylidene resin, vinyl ester resin, cellulose acetate resin, polyvinyl alcohol resin, etc.) or thermosetting resin (for example, phenol resin, melamine resin, polyester resin, silicone resin, epoxy resin) Resin) can further contain at least one or more of such. By blending these resins, a molded product having excellent characteristics can be obtained.

  These additives can be blended at any stage of producing the resin composition of the present invention. For example, when blending the components (A), (B), (C), and (D) The method of adding simultaneously and the method of adding after melt-kneading at least 2 component resin beforehand are mentioned.

  The method for producing the resin composition of the present invention is not particularly limited. For example, (A) a styrene resin, (B) a graft polymer, (C) an aliphatic polyester, (D) an impact resistance improver, and If necessary, after blending crystal nucleating agent, filler, plasticizer, and other additives in advance, at a melting point or higher, using a single- or twin-screw extruder, uniformly melt-kneading or mixing in solution A method of removing is preferably used.

  In the present invention, the obtained resin composition can be molded by any method such as generally known injection molding, extrusion molding, inflation molding, blow molding, etc., and can be widely used as a molded product of any shape. Molded products include films, sheets, fibers / clothes, non-woven fabrics, injection molded products, extrusion molded products, vacuum / pressure molded products, blow molded products, or composites with other materials. Automobile materials such as parts, TV, air conditioner, VTR, audio, vacuum cleaner, refrigerator, telephone, fax machine, binoculars, camera, watch, computer, personal computer, printer, copier, etc. , Horticulture materials, fishery materials, toilet parts such as toilets, civil engineering and construction materials such as kitchens and bathrooms, stationery, medical supplies, miscellaneous goods, daily necessities, food containers, containers for medical products, and other uses be able to. The molded product can also be used after being painted, plated or the like.

  In order to describe the present invention more specifically, examples and comparative examples will be described below, but the present invention is not limited to these examples. In the examples, parts and% indicate parts by weight and% by weight, respectively.

[Reference Example 1] (A) Styrenic Resin A method for preparing a styrene resin is shown below. The polymer obtained was dried under reduced pressure at 70 ° C. for 5 hours, and then a methyl ethyl ketone solution having a concentration of 0.4 g / 100 ml was prepared, and the intrinsic viscosity was measured using an Ubbelohde viscometer at 30 ° C.

  <A-1> PS Japan "HF77" (polystyrene: standard grade) was used. The intrinsic viscosity of the soluble part of methyl ethyl ketone was 0.50 dl / g.

<A-2> A 20-liter capacity stainless steel autoclave equipped with baffles and foudra-type stirring blades, and 0.05 parts by weight of methyl methacrylate / acrylamide copolymer (described in Japanese Patent Publication No. 45-24151) are ion-exchanged. A solution dissolved in 165 parts by weight of water was added and stirred at 400 rpm, and the system was replaced with nitrogen gas. Next, the following mixed substances were added with stirring in the reaction system, and the temperature was raised to 60 ° C. to initiate polymerization.
Styrene 70 parts by weight Acrylonitrile 30 parts by weight t-dodecyl mercaptan 0.2 parts by weight 2,2′-azobisisobutyronitrile 0.4 parts by weight

  After raising the reaction temperature to 65 ° C. over 30 minutes, the temperature was raised to 100 ° C. over 120 minutes. Thereafter, the reaction system was cooled, the polymer was separated, washed, and dried according to the usual method to obtain a bead-shaped polymer. The intrinsic viscosity of the methyl ethyl ketone soluble part of the obtained styrene-based resin was 0.53 dl / g.

  <A-3> Suspension polymerization was similarly performed except that 70 parts by weight of styrene and 30 parts by weight of acrylonitrile in the above <A-2> were changed to 70 parts by weight of methyl methacrylate, 25 parts by weight of styrene, and 5 parts by weight of acrylonitrile. went. The intrinsic viscosity of the methyl ethyl ketone soluble part of the obtained styrene resin was 0.35 dl / g.

  <A-4> “576H” (polystyrene: high impact grade) manufactured by BASF Japan was used.

  <A-5> "Stylac 121" (ABS: standard grade) manufactured by Asahi Kasei Chemical was used.

<A-6>
Suspension polymerization was performed in the same manner except that the amount of t-dodecyl mercaptan of <A-2> was changed to 0.35 parts by weight. The intrinsic viscosity of the methyl ethyl ketone soluble part of the obtained styrene resin was 0.41 dl / g.

[Reference Example 2] (B) Graft Polymer A method for preparing a graft copolymer is shown below. The graft ratio was determined by the following method. Acetone was added to a predetermined amount (m) of the graft copolymer and refluxed for 4 hours. This solution was centrifuged at 8000 rpm (centrifugal force 10,000 G (about 100 × 10 ³ m / s ² )) for 30 minutes, and the insoluble matter was filtered off. This insoluble matter was dried under reduced pressure at 70 ° C. for 5 hours, and the weight (n) was measured.
Graft ratio = [(n) − (m) × L] / [(m) × L] × 100
Here, L means the rubber content of the graft copolymer.

  The filtrate of the acetone solution was concentrated with a rotary evaporator to obtain a precipitate (acetone soluble matter). The soluble matter was dried under reduced pressure at 70 ° C. for 5 hours, a 0.4 g / 100 ml concentration methyl ethyl ketone solution was prepared, and the intrinsic viscosity was measured using an Ubbelohde viscometer under a temperature condition of 30 ° C.

<B-1>
Polybutadiene (weight average particle size 0.35 μm) 50 parts by weight (Nipol LX111K, manufactured by Nippon Zeon Co., Ltd.) (solid content conversion)
Potassium oleate 0.5 parts by weight Glucose 0.5 parts by weight Sodium pyrophosphate 0.5 parts by weight Ferrous sulfate 0.005 parts by weight Deionized water 120 parts by weight.

  The above substances were charged into a polymerization vessel and heated to 65 ° C. with stirring. The polymerization was started when the internal temperature reached 65 ° C., and 35 parts by weight of methyl methacrylate, 12.5 parts by weight of styrene, 2.5 parts by weight of acrylonitrile, and 0.3 parts by weight of t-dodecyl mercaptan were taken over 5 hours. Continuous dripping. In parallel, an aqueous solution consisting of 0.25 parts by weight of cumene hydroperoxide, 2.5 parts by weight of potassium oleate and 25 parts by weight of pure water was continuously added dropwise over 7 hours to complete the reaction. The obtained graft copolymer latex was coagulated with sulfuric acid, neutralized with caustic soda, washed, filtered and dried to obtain a powder. The graft ratio of the obtained graft copolymer was 40%, and the intrinsic viscosity of methyl ethyl ketone-soluble component was 0.30 dl / g.

  <B-2> 35 parts by weight of methyl methacrylate, 12.5 parts by weight of styrene, and 2.5 parts by weight of acrylonitrile are changed to 42.5 parts by weight of methyl methacrylate and 7.5 parts by weight of styrene. Except that, emulsion polymerization was carried out in the same manner. The graft ratio of the obtained graft copolymer was 42%, and the intrinsic viscosity of the methyl ethyl ketone-soluble component was 0.28 dl / g.

  <B-3> Emulsion polymerization is carried out in the same manner except that 35 parts by weight of methyl methacrylate, 12.5 parts by weight of styrene and 2.5 parts by weight of acrylonitrile are changed to 50 parts of methyl methacrylate. It was. The graft ratio of the obtained graft copolymer was 43%, and the intrinsic viscosity of methyl ethyl ketone-soluble component was 0.27 dl / g.

  <B-4> The same as above except that 35 parts by weight of methyl methacrylate, 12.5 parts by weight of styrene and 2.5 parts by weight of acrylonitrile are changed to 35 parts by weight of styrene and 15 parts by weight of acrylonitrile. Emulsion polymerization was performed. The graft ratio of the obtained graft copolymer was 38%, and the intrinsic viscosity of methyl ethyl ketone-soluble component was 0.33 dl / g.

[Reference Example 3] (C) Aliphatic polyester <C-1> Poly-L-lactic acid having a weight average molecular weight of 200,000, a D-lactic acid unit of 1%, and a melting point of 175 ° C. was used.

  <C-2> Poly-L-lactic acid having a weight average molecular weight of 210,000 and a D-lactic acid unit of 4% was used.

  <C-3> Poly-L-lactic acid having a weight average molecular weight of 150,000 and a D-lactic acid unit of 0.5% was used.

[Reference Example 4] (D) Impact resistance improver <D-1> Ethylene / glycidyl methacrylate / methyl acrylate copolymer (Sumitomo Chemical "Bond First" 7M)

  <D-2> Ethylene / methyl methacrylate copolymer (Sumitomo Chemical "Aklift" WK402)

  <D-3> Ethylene / methacrylic acid copolymer ionomer (“High Milan” 1855 manufactured by Mitsui DuPont Polychemical)

  <D-4> Maleic anhydride-modified SEBS (Asahi Kasei Chemical "Tuftec" M1913)

  <D-5> Thermoplastic polyurethane elastomer ("Milactolan" E380, manufactured by Nihon Milactolan)

[Reference Example 5] (E1) Multivalent carboxylic acid anhydride <E1-1> Maleic acid anhydride manufactured by Tokyo Chemical Industry was used.

  <E1-2> A succinic anhydride manufactured by Tokyo Chemical Industry was used.

[Reference Example 6] (E2) Polyvalent carboxylic acid <E2-1> Maleic acid manufactured by Tokyo Chemical Industry was used.

[Reference Example 7] Crystal nucleating agent <F-1>"LMS300"(talc; inorganic crystal nucleating agent) manufactured by Fuji Talc Kogyo was used.

  <F-2> Nippon Kasei's “Slipax L” (ethylenebislauric acid amide; organic crystal nucleating agent) was used.

[Reference Example 8] Plasticizer <G-1>"PEG4000" (polyethylene glycol) manufactured by Sanyo Kasei was used.

[Reference Example 9] Carboxyl terminal blocking agent <H-1> “Carbodilite” HMV-8CA (carbodiimide) manufactured by Nisshinbo was used.

[Examples 1 to 34, Comparative Examples 1 to 7]
After dry blending the raw materials having the compositions described in Tables 1, 2, and 3, melt mixing pelletizing was performed using a twin screw extruder (Nippon Steel Works TEX-30) set at an extrusion temperature of 220 ° C.

  Tests obtained by injection molding the pellets obtained in Examples 1 to 24 and Comparative Examples 1 to 7 using a Toshiba Machine IS55EPN injection molding machine at a molding temperature of 230 ° C. and a mold temperature of 40 ° C. About the piece, each characteristic was evaluated with the following measuring methods. The pellets obtained in Examples 25 to 34 were all molded and evaluated in the same manner except that the conditions were changed to a molding temperature of 230 ° C and a mold temperature of 80 ° C.

  [Flowability]: Flowability was evaluated from the molding lower limit pressure (gauge pressure) during injection molding. The smaller the minimum filling pressure, the better the fluidity.

  [Tensile Properties]: Tensile properties were evaluated according to ASTM D638.

  [Impact Resistance]: Impact resistance was evaluated according to ASTM D256-56A.

  [Heat resistance]: The heat distortion temperature was measured according to ASTM D648 (load: 0.46 MPa).

  [Area ratio]: For a molded product obtained by injection molding, after dyeing (A) a styrene resin, (B) a graft polymer and (D) an impact resistance improver by an osmium block dyeing method, an ultrathin section About the sample which cut out, it expanded and magnified 6000 time with the transmission electron microscope, and observed and image | photographed the cross section. Further expanded to 4 times, (C) the area (X) of (B) and (D) dispersed in the aliphatic polyester, and (A) (B) and (D) dispersed in the styrene resin. ) Was determined from the photograph using the weight method, and the area ratio was determined according to the formula (X) / ((X) + (Y)).

  The results are shown in Table 1, Table 2, Table 3, and Table 4, respectively.

  From Examples 1-34 and Comparative Examples 1-7, it turns out that the resin composition of this invention is excellent in fluidity | liquidity, a tensile characteristic, impact resistance, and heat resistance.

  Automotive materials, electrical / electronic equipment materials, agricultural materials, horticultural materials, fishery materials, toilet parts such as toilets, civil engineering / building materials, stationery, medical supplies, miscellaneous goods, daily necessities, food, medical products, etc. Useful as a container or other application.

Claims (10)

A resin composition comprising (A) a styrenic resin, (B) a graft polymer, (C) an aliphatic polyester, and (D) an impact resistance improver. The amount of (A) styrene resin added is 30 to 60% by weight based on the total amount of (A) styrene resin, (B) graft polymer, (C) aliphatic polyester and (D) impact modifier. (B) The addition amount of the graft polymer is 10 to 50% by weight, (C) the addition amount of the aliphatic polyester is 60 to 10% by weight, and (D) the addition amount of the impact resistance improver is 2 to 20% by weight. The resin composition according to claim 1, wherein the resin composition is present. (A) Styrenic resin is (a) 0 to 99% by weight of unsaturated carboxylic acid alkyl ester unit, (b) 1 to 100% by weight of aromatic vinyl unit, (c) vinyl cyanide unit 0 to 50 3. The styrenic resin according to claim 1, wherein the styrene-based resin is copolymerized in an amount of 0% by weight and (d) 0 to 99% by weight of other vinyl units copolymerizable therewith. Resin composition. (B) Graft polymer is (r) 10 to 80% by weight of rubbery polymer, (a) 20 to 90% by weight of unsaturated carboxylic acid alkyl ester unit, and (b) aromatic vinyl unit 0 to 70%. A graft polymer in which 0% by weight, (c) 0 to 50% by weight of vinyl cyanide units, and (d) 0 to 70% by weight of other vinyl units copolymerizable therewith are graft polymers. The resin composition according to any one of claims 1 to 3. (C) Aliphatic polyester has polylactic acid as a main component, The resin composition of any one of Claims 1-4 characterized by the above-mentioned. (D) The impact resistance improver is at least one selected from a polymer containing an acrylic unit, a polymer containing a unit having an acid anhydride group and / or a glycidyl group, and polyurethane rubber. The resin composition according to any one of 1 to 5. (B) The graft copolymer is (r) 10 to 80% by weight of a butadiene polymer, (a) 20 to 90% by weight of an unsaturated carboxylic acid alkyl ester unit, and (b) an aromatic vinyl unit 0 to 70% by weight, (c) 0 to 50% by weight of vinyl cyanide units, and (d) a graft polymer in which 0 to 70% by weight of other vinyl units copolymerizable therewith are graft-polymerized, D) The impact modifier is at least one selected from a polymer containing an acrylic acid unit, a polymer containing a unit having an acid anhydride group and / or a glycidyl group, and polyurethane rubber. The resin composition according to any one of 1 to 6. Furthermore, the resin composition of any one of Claims 1-7 formed by mix | blending at least 1 sort (s) chosen from (E1) polyhydric carboxylic acid anhydride and (E2) polyhydric carboxylic acid. (E1) The resin composition according to claim 8, wherein the polyvalent carboxylic acid anhydride is either maleic acid anhydride or succinic acid anhydride. The molded product formed by shape | molding the resin composition of any one of Claims 1-9.