JP5140988B2 - Resin composition and molded article comprising the same - Google Patents

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, polylactic acid, and a methacrylic resin at a specific ratio. It was.

That is, the present invention
(1) A resin composition comprising (A) a styrene resin, (B) a graft polymer, (C) polylactic acid, and (D) a methacrylic resin, (A) a styrene resin, (B) (A) Styrenic resin 10% by weight or more, (B) 0-50% by weight of graft polymer, (C) polylactic acid, based on the total amount of graft polymer, (C) polylactic acid and (D) methacrylic resin Less than 85 wt%, and (D) 1-30 wt% methacrylic resin,
(A) The mixing ratio of the styrene resin and the (D) methacrylic resin is 100% by weight of the total amount of the (A) styrene resin and the (D) methacrylic resin. And
(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 And (d) a resin composition which is a styrene resin in which 0 to 99% by weight of other vinyl units copolymerizable with these are copolymerized,
(2) (A) 20 to 58% by weight of styrene resin, (B) based on the total amount of (A) styrene resin, (B) graft polymer, (C) polylactic acid and (D) methacrylic resin The resin composition according to (1), wherein the graft polymer is 0 to 30% by weight, (C) polylactic acid 30 to 60% by weight, and (D) methacrylic resin 2 to 15% by weight,
(3) (A) the styrene resin is (a) an unsaturated carboxylic acid alkyl ester unit of 0 to 70% by weight, (b) an aromatic vinyl unit of 25 to 100% by weight, and (c) a vinyl cyanide type. The resin composition according to any one of (1) to (2), wherein the unit is 0 to 30% by weight of a copolymerized styrene resin,
(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 A graft polymer in which 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 therewith are graft-polymerized. The resin composition according to any one of (1) to (3),
(5) (B) Graft copolymer is (r) butadiene-based polymer 10 to 80% by weight, (a) unsaturated carboxylic acid alkyl ester unit 20 to 90% by weight, (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. The resin composition according to any one of (1) to (4) ,
(6) The resin composition according to any one of (1) to (5) , wherein (C) polylactic acid contains 80 mol% or more of L-form or D-form among the total lactic acid components,
(7) (D) The resin composition according to any one of (1) to (6) , wherein the methacrylic resin has a syndiotacticity of 40% or more,
(8) A molded product obtained by molding the resin composition according to any one of (1) to (7) ,
It is.

In the resin composition of the present invention and its molded article, it is a resin composition comprising (A) a styrene resin, (C) polylactic acid, and (D) a methacrylic resin , and in a preferred embodiment, a dicarboxylic acid anhydride or dicarboxylic acid A resin composition comprising at least one selected from acids, and in a more preferred embodiment, (B) a resin composition comprising a graft polymer, which has excellent strength and impact resistance. A low environmental load resin composition having heat resistance and molding processability 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-type resin, The intrinsic viscosity [(eta)] measured at 30 degreeC using the methyl ethyl ketone solvent is 0.20-2.00 dl / g, Especially 0.25-1. The range of 50 dl / g is preferable 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 (r) a graft copolymer having a structure in which a monomer or a monomer mixture was grafted to a rubbery polymer. Is. The graft ratio of the graft polymer is not particularly limited, but is 10 to 100% by weight, particularly 20 to 80% by weight, in order to obtain a resin composition having a good balance between impact resistance and gloss. 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. .

In the present invention, is used is (C) polylactic acid.

  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) polylactic acid 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.

As a method for producing (C) a polylactic acid, can be used known polymerization methods can be employed direct polymerization method from lactic, ring-opening polymerization via lactide or the like.

(C) The molecular weight and molecular weight distribution of polylactic acid are 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, Particularly preferred is 80,000 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 polylactic acid 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) polylactic acid is 0.1 to 10 in that a resin composition having excellent heat resistance is obtained. It is preferable that it exists in the range.

In the present invention, when any one of (A) styrenic resin and (C) polylactic acid 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) methacrylic resin used in the present invention is a polymer of alkyl (meth) acrylate.

  Examples of alkyl (meth) acrylate include methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, cyclohexyl methacrylate, hydroxyethyl methacrylate, glycidyl methacrylate, allyl methacrylate, Aminoethyl acrylate, propylaminoethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, butanediol diacrylate, diacryl Acid nonanediol, polyethylene glycol diacrylate, methyl 2- (hydroxymethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, methacrylic acid, methacrylate Ethyl acetate, butyl methacrylate, cyclohexyl methacrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate Glycidyl methacrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentanyl methacrylate, pentamethylpiperidyl methacrylate, tetramethylpiperidyl methacrylate, benzyl methacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, dimethacrylate Acid polyethylene glycol etc. are mentioned, These 1 type (s) or 2 or more types can be used.

In the present invention, the (D) methacrylic resin preferably has a weight average molecular weight of 1,000 to 450,000, more preferably 10,000 to 200,000, and still more preferably 30,000 to 150,000. The weight average molecular weight here is a weight average molecular weight in terms of polymethyl methacrylate (PMMA) measured by GPC using hexafluoroisopropanol as a solvent.

In the present invention, in terms of heat resistance, the glass transition temperature of (D) methacrylic resin is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, further preferably 80 ° C. or higher, particularly preferably 90 ° C. or higher, 100 ° C. The above is most preferable. Although an upper limit is not specifically limited, 150 degreeC or less is preferable at the point of a moldability. The glass transition temperature here is a value of the glass transition temperature obtained by differential scanning calorimeter (DSC) measurement, and is a temperature at which the specific heat capacity change in the glass transition temperature region becomes a half value.

In the present invention, the syndiotacticity of the methacrylic resin is preferably 20% or more, more preferably 30% or more, and further preferably 40% or more. Although an upper limit is not specifically limited, 90% or less is preferable at the point of a moldability. In terms of heat resistance, the heterotacticity is preferably 50% or less, more preferably 40% or less, and further preferably 30% or less. In terms of heat resistance, isotacticity is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less. Syndiotacticity, heterotacticity, and isotacticity as used herein are values calculated from the integrated intensity ratio of linearly branched methyl groups by 1H-NMR measurement using deuterated chloroform as a solvent.

(D) As a manufacturing method of a methacryl resin , well-known polymerization methods, such as block polymerization, solution polymerization, suspension polymerization, and emulsion polymerization, can be used.

  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, by adding a small amount of (D) methacrylic resin to (A) styrenic resin and (C) polylactic acid, the strength, heat resistance, and impact resistance can be specifically improved. As a preferred embodiment, by adding a small amount of at least one selected from (E1) dicarboxylic acid anhydride and (E2) dicarboxylic acid, the strength, heat resistance, and impact resistance can be unexpectedly improved, and more preferable. As an embodiment, a small amount of (D) methacrylic resin is added to (A) styrene resin, (B) graft polymer, and (C) polylactic acid, and further selected from (E1) dicarboxylic acid anhydride and (E2) dicarboxylic acid By adding a small amount of at least one selected from the above, strength, heat resistance, and impact resistance can be dramatically improved unexpectedly.

The mixing ratio of (A) styrene resin, (C) polylactic acid, and (D) methacrylic resin in the resin composition of the present invention is such that (A) styrene resin, (C) polylactic acid, and (D) methacrylic resin are mixed. (A) Styrenic resin is 10 weight% or more with respect to a total amount, Preferably it is 25-70 weight%, More preferably, it is 30-60 weight%, Most preferably, it is 35-60 weight%. Moreover, the addition amount of (C) polylactic acid is less than 85 weight%, Preferably it is 65 to 10 weight%, More preferably, it is the range of 60 to 10 weight%. (D) The addition amount of the methacrylic resin is 1 to 30% by weight, preferably 2 to 20% by weight, more preferably 2 to 15% by weight, still more preferably 2 to 9% by weight, and particularly preferably 2 to 8.5%. % By weight, most preferably 2 to 7.4% by weight.

  In the present invention, the blending amount of (E1) dicarboxylic acid anhydride and (E2) dicarboxylic acid is based on 100 parts by weight of the total amount of (A) styrene resin, (C) aliphatic polyester and (D) acrylic resin. 0 to 5 parts by weight, preferably in terms of impact resistance and heat resistance, preferably 0.05 to 2 parts by weight, more preferably 0.1 to 1 part by weight, still more preferably 0.1 -0.5 parts by weight.

The mixing ratio of (A) styrene resin, (B) graft polymer, (C) polylactic acid, (D) methacrylic resin of the resin composition of the present invention is as follows: (A) styrene resin, (B) graft weight (A) Styrenic resin is 10% by weight or more, preferably 25 to 70% by weight, more preferably 30 to 60% by weight, based on the total amount of coalescence, (C) polylactic acid and (D) methacrylic resin , Most preferably, it is 35-60 weight%. The amount of (B) graft polymer added is 5 to 50% by weight, preferably 7 to 50% by weight, and more preferably 10 to 50% by weight. Furthermore, the addition amount of (C) polylactic acid is less than 85% by weight, preferably 65 to 10% by weight, more preferably 60 to 10% by weight. (D) The addition amount of the methacrylic resin is 1 to 30% by weight, preferably 2 to 20% by weight, more preferably 2 to 15% by weight, still more preferably 2 to 9% by weight, and particularly preferably 2 to 8.5%. % By weight, most preferably 2 to 7.4% by weight.

  When the resin composition of the present invention is a resin composition obtained by blending (B) a graft polymer, the blending amount of (E1) dicarboxylic acid anhydride and (E2) dicarboxylic acid is (A) styrene. It is 0 to 5 parts by weight with respect to 100 parts by weight of the total amount of the resin, (B) graft polymer, (C) aliphatic polyester and (D) acrylic resin, in terms of impact resistance and heat resistance. The amount is preferably 0.05 to 2 parts by weight, more preferably 0.1 to 1 part by weight, and still more preferably 0.1 to 0.5 part by weight.

Further, in the present invention, (A) mixing ratio of the styrene-based resin and (D) a methacrylic resin, the total amount of 100 wt% of (A) a styrenic resin and (D) a methacrylic resin, is (D) a methacrylic resin 1 2.5% by weight or less , more preferably 1 to 12.5% by weight, particularly preferably 3.2 to 12.5% by weight, when both excellent impact resistance and heat resistance are achieved. Can be expressed.

The resin composition of the present invention is a mixture of (A) a styrene resin, (C) polylactic acid, and (D) a methacrylic resin in the composition as described above. It can be obtained by mixing (B) graft polymer, (C) polylactic acid, and (D) methacrylic resin . In the obtained styrene resin, (a) unsaturated carboxylic acid alkyl ester unit is a resin component. 1 to 90% by weight, preferably 10 to 80% by weight, (b) 0.1 to 80% by weight, preferably 1 to 70% by weight, (c) vinyl cyanide unit 0 -45% by weight, preferably 0-40% by weight, (d) by making the other vinyl units copolymerizable with these 0-85% by weight, preferably 0-80% by weight, Get sufficient impact and heat resistance Door can be.

When the resin composition of the present invention is a resin composition obtained by blending (B) a graft polymer, in the resin composition of the present invention, (A) a styrene resin, (C) polylactic acid And a (B) graft polymer domain dispersed in the matrix, wherein the (B) graft polymer, which is a domain, has an area ratio existing in (C) polylactic acid. It is preferable that it exists in 10 to 90% of range.

  For example, for a molded product obtained by injection molding, a sample obtained by staining an ultrathin section after staining (A) a styrene resin and (B) a graft polymer by an osmium block staining method is applied to a transmission electron microscope. By observing the cross section at a magnification of 6000, the dispersion form of the (B) graft polymer 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 will be dispersed in the (C) polylactic acid phase, and (a) the unsaturated carboxylic acid alkyl ester. It can be confirmed that (B) the graft polymer is less dispersed in the (C) polylactic acid phase and (A) is dispersed in the styrene resin phase.

Here, the area ratio in the cross-sectional photograph in which (B) the graft polymer is present in (C) polylactic acid is in the range of 10 to 90%, preferably 20 to 85%, more preferably 30 to 80%. It is a 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) As a method for measuring the area ratio in which the graft polymer is present in (C) polylactic acid , a cross section of the molded product was photographed with a transmission electron microscope in the same manner as described above. Further expanded to 4 times, (C) the area (X) of the dispersion graft polymer in polylactic acid and (A) the area (Y) of the dispersion graft polymer in styrene resin were cut out from the photograph and used the weight method. And obtained 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 0.1 to 30 parts by weight with respect to 100 parts by weight of (C) polylactic acid. 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 (C) polylactic acid. Is more preferable.

  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.

The plasticizer content is preferably in the range of 0.01 to 30 parts by weight, more preferably in the range of 0.1 to 20 parts by weight, with respect to 100 parts by weight of (C) polylactic acid , and 0.5 to The range of 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 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 fibers and regenerated fibers are more preferable from the viewpoint of taking advantage of the biodegradability of the polylactic acid 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 (C) polylactic acid .

  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 not only blocks the end of (C) polylactic acid but also has a low acidity such as lactic acid and formic acid generated by thermal decomposition or hydrolysis of naturally-occurring organic fillers. The carboxyl group of the molecular compound can also 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 (C) polylactic acid .

Addition timing of the carboxyl group reactive end capping agent is not particularly limited, not only to improve the heat resistance, in that it can improve the mechanical properties and durability, after melt-kneading (C) and the polylactic acid, It is preferable to knead with others.

  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, polyamide resins, polyphenylene sulfide resins, polyether ether ketone resins, polyester resins other than aliphatic polyesters, polysulfone resins, polyether sulfone resins, as long as the object of the present invention is not impaired. , Aromatic and aliphatic polycarbonate resins, polyarylate resins, polyphenylene oxide resins, polyacetal resins, polyimide resins, polyetherimide resins, aromatic and aliphatic polyketone resins, fluorine resins, polyvinyl chloride resins, polyvinylidene chloride resins, Vinyl ester resin, cellulose acetate resin, polyvinyl alcohol resin, etc.) or thermosetting resin (eg phenol resin, melamine resin, polyester resin, silicone resin, epoxy resin, etc.). Furthermore it is possible to contain at least one more. 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) polylactic acid, (D) a methacrylic resin, and as necessary. Crystal nucleating agent, plasticizer, filler, and other additives are blended in advance and then melted and kneaded uniformly with a single or twin screw extruder above the melting point, or the solvent is removed after mixing in solution Etc. are 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 are 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. It is useful for electronic equipment materials, agricultural materials, horticultural materials, fishery materials, civil engineering / building materials, stationery, medical supplies, toilet seats, miscellaneous goods, or other uses. 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.

<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> 50 parts by weight of styrene, 10 parts by weight of acrylonitrile, 40 parts by weight of N-phenylmaleimide, 0.2 part by weight of t-dodecyl mercaptan, 0.4 part by weight of 2,2′-azobisisobutyronitrile Was solution polymerized in cyclohexanone solvent. Thereafter, the polymer was obtained by cooling the reaction system, reprecipitation with a methanol solution, washing, drying, and pulverization according to a usual method. The intrinsic viscosity of the methyl ethyl ketone soluble part of the obtained styrene resin was 0.33 dl / g.

<A-5>
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.

  <A-6> “576H” (polystyrene: high impact grade) manufactured by BASF Japan was used.

  <A-7> "Stylac 121" (ABS: standard grade) manufactured by Asahi Kasei Chemical was used.

[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 part by weight Glucose 0.5 part by weight Sodium pyrophosphate 0.5 part by weight Ferrous sulfate 0.005 part by weight Deionized water 120 part 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) Polylactic acid <C-1> Poly-L-lactic acid having a weight average molecular weight of 160,000 and a D-lactic acid unit of 1.2% 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 200,000 and a D-lactic acid unit of 1% was used.

[Reference Example 4] (D) Methacrylic Resin <D-1> Methacrylic Resin (Sumitomo Chemical “Sumipex LG21” Tg 105 ° C., Syndiotacticity 41%, Mw 80,000, MFR 21 g / 10 min (230 ° C., 37.2 N) )

  <D-2> Methacrylic resin (Kuraray “Parapet” HR-L, Tg 117 ° C., syndiotacticity 56%, Mw 90,000, MFR 2 g / 10 min (230 ° C., 37.2 N))

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

  <E1-2> Tokyo Chemical Industry's succinic anhydride was used.

[Reference Example 6] (E2) Dicarboxylic 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 Chemical Industries was used.

[Reference Example 9] Filler <H-1> “CS3J948” (glass fiber) manufactured by Nittobo was used.

[Reference Example 10] Carboxyl terminal blocking agent <I-1> “Carbodilite” LA-1 (carbodiimide) manufactured by Nisshinbo was used.

[Examples 1 , 2 , 5 to 7, Comparative Examples 1 to 6 , 14, 15 ]
After dry blending the raw materials having the composition shown in Table 1, melt mixing pelletizing was performed using a twin screw extruder (TEX-30 manufactured by Nippon Steel Works) set at an extrusion temperature of 220 ° C.

The pellets obtained in Examples 1 , 2, 5 to 7 and Comparative Examples 1 to 6 , 14 , and 15 were injected under conditions of a molding temperature of 230 ° C. and a mold temperature of 40 ° C. using an IS55EPN injection molding machine manufactured by Toshiba Machine. About the test piece obtained by shape | molding, each characteristic was evaluated with the following measuring methods.

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

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

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

  [TEM Observation]: Using a transmission electron microscope (HITACHI, ELECTRON MICROSCOPE H-700), a cross-section of the obtained resin composition was observed for morphology, and a photograph with a magnification of 1000 times (1 cm on the photograph corresponds to 10 μm) The longest particle diameter of any 30 dispersed individual spherical dispersed phases taken on the photograph was measured, and the number averaged value was taken as the average particle diameter.

  Table 1 shows the measurement results of tensile properties, impact resistance, heat resistance, and TEM observation of each sample.

From Examples 1 , 2 , 5 to 7 and Comparative Examples 1 to 6 , 14, and 15 , it can be seen that the resin composition of the present invention is excellent in tensile properties, impact resistance, and heat resistance.

[Examples 8-19 , 21-23 , Comparative Examples 7-13 , 16-21 ]
After dry blending the raw materials composed of the compositions shown in Tables 2, 3, and 4, melt mixing pelletizing was performed using a twin screw extruder (TEX-30 manufactured by Nippon Steel Works) set at an extrusion temperature of 220 ° C.

The pellets obtained in Examples 8 to 19 , 21 to 23 , and Comparative Examples 7 to 13 and 16 to 21 were used under the conditions of a molding temperature of 230 ° C. and a mold temperature of 40 ° C. using an IS55EPN injection molding machine manufactured by Toshiba Machine. About the test piece obtained by carrying out injection molding, each characteristic was evaluated with the following measuring methods. The pellets obtained in Comparative Examples 17 to 21 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 85 ° 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]: The 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 article obtained by injection molding, a sample obtained by cutting out an ultrathin section after dyeing (A) a styrene resin and (B) a graft polymer by an osmium block dyeing method. The cross section was observed and photographed at an magnification of 6000 with an electron microscope. Further expanded to 4 times, (C) the area (X) of (B) dispersed in the aliphatic polyester and (A) the area (Y) of (B) dispersed in the styrene resin The area ratio was calculated according to the formula (X) / ((X) + (Y)).

  Tables 2, 3, and 4 show the measurement results of the fluidity, tensile properties, impact resistance, heat resistance, and area ratio of each sample, respectively.

  In Example 17, the TEM observation was performed in the same manner as in Example 1. As a result, the average particle size of the aliphatic polyester was 200 nm.

From Examples 8 to 19 , 21 to 23 , and Comparative Examples 7 to 13 and 16 to 21 , it can be seen that the resin composition of the present invention is excellent in fluidity, tensile properties, impact resistance, and heat resistance.

  It can be used as materials for automobiles, materials for electric / electronic devices, materials for agriculture, materials for horticulture, materials for fisheries, materials for civil engineering / building, stationery, medical supplies, toilet seats, miscellaneous goods, or other various uses.

Claims (8)

(A) Styrenic resin, (B) graft polymer, (C) polylactic acid, and (D) a methacrylic resin composition, (A) styrene resin, (B) graft polymer , (C) polylactic acid and (D) methacrylic resin, based on the total amount of (A) styrene resin 10% by weight or more, (B) 0-50% by weight of graft polymer, (C) 85% by weight of polylactic acid And (D) methacrylic resin 1 to 30% by weight,
(A) The mixing ratio of the styrene resin and the (D) methacrylic resin is 100% by weight of the total amount of the (A) styrene resin and the (D) methacrylic resin. And
(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 And (d) a resin composition which is a styrene resin copolymerized with 0 to 99% by weight of other vinyl units copolymerizable therewith. (A) 20-58 wt% styrene resin, (B) graft polymer, based on the total amount of (A) styrene resin, (B) graft polymer, (C) polylactic acid and (D) methacrylic resin 2. The resin composition according to claim 1, comprising 0 to 30% by weight, (C) 30 to 60% by weight of polylactic acid, and (D) 2 to 15% by weight of methacrylic resin. (A) Styrenic resin comprises (a) unsaturated carboxylic acid alkyl ester unit 0 to 70% by weight, (b) aromatic vinyl unit 25 to 100% by weight, and (c) vinyl cyanide unit 0 to The resin composition according to any one of claims 1 to 2, wherein 30% by weight is a copolymerized styrene resin. (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. (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) 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 4 , wherein the resin composition is characterized in that (C) Polylactic acid contains 80 mol% or more of L-form or D-form among the total lactic acid components, The resin composition of any one of Claims 1-5 characterized by the above-mentioned. (D) The resin composition according to any one of claims 1 to 6 , wherein the methacrylic resin has a syndiotacticity of 40% or more. A molded article formed by molding the resin composition according to any one of claims 1 to 7 .