JP5504548B2 - Styrenic resin composition - Google Patents

Description

The present invention comprises a styrene resin, a graft polymer, and an aliphatic polyester, and greatly reduces CO ₂ emissions during production without deteriorating the excellent impact resistance, heat resistance and molding processability of the styrene resin. The present invention relates to a styrenic resin composition having a low environmental load that can be reduced to a low level and having permanent antistatic properties.

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, since styrene-based resins are made from petroleum resources, CO ₂ emissions into the atmosphere during production and the environmental burden at the time of disposal have been regarded as problems in recent years, and materials containing non-petroleum resources are required as environmentally low-load materials. ing.

  Therefore, recently, from the viewpoint of global environmental conservation, biodegradable polymers that are decomposed in the natural environment by the action of microorganisms existing in soil and water have attracted attention, 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. In addition, a polylactic acid resin composition containing polylactic acid in an amount of 50% by weight or more based on the total weight of the resin composition, and a general-purpose resin composition in which a polylactic acid resin is blended with the styrene resin of the present invention has a design concept Different.

  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.

Moreover, although the semipermanent antistatic resin composition (patent document 5) which mixed the ABS resin and the polyamide elastomer is disclosed, this resin composition does not contain an aliphatic polyester resin and can be obtained. The resin composition could not be an environmentally low load that can significantly reduce CO ₂ emission during production.
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) Japanese Patent Application Laid-Open No. Sho 62-116652 (Page 2)

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 is to provide excellent impact resistance, heat resistance and molding processability of the styrene resin. An object of the present invention is to provide a styrene resin composition that is an environmentally low-load styrene resin composition that can significantly reduce the amount of CO ₂ emission during production and that has permanent antistatic properties.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have made a styrene resin, a graft polymer, polylactic acid , and a resin composition containing a polymer having a volume resistivity of 10 ¹³ Ωcm or less as described above. It turns out that the problem can be solved.

That is, the present invention
(1) (A) Styrenic resin (not including rubber polymer obtained by graft polymerization of aromatic vinyl unit) , (B) graft polymer, (C) polylactic acid, and (D) volume resistivity A resin composition composed of a polymer having a value of 10 ¹³ Ωcm or less, with respect to the total amount of (A) a styrene resin, (B) a graft polymer, and (C) a polylactic acid thermoplastic resin, (D) A styrenic resin composition characterized in that the polymer having a volume resistivity of 10 ¹³ Ωcm or less is in the range of 1 to 30% by weight,
(B) The graft polymer has a graft ratio of 20 to 80% by weight,
(R) 10 to 80% by weight of diene rubber, (a) 20 to 90% by weight of unsaturated carboxylic acid alkyl ester unit, (b) 0 to 70% by weight of aromatic vinyl unit, (c) vinyl cyanide A styrene resin composition which is a graft polymer obtained by graft polymerization of 0 to 50% by weight of system units and (d) 0 to 70% by weight of other vinyl units copolymerizable therewith.
(2) (D) A polymer having a volume resistivity of 10 ¹³ Ωcm or less is selected from alkylene oxide residues, quaternary ammonium salt residues, and alkali metal ionomer residues having an average number molecular weight of 100 to 10,000. A styrenic resin composition as described in (1) above, which is a polymer containing a group,
(3) (D) The polymer having a volume resistivity value of 10 ¹³ Ωcm or less is polyether amide, polyether ester or polyether ester amide, wherein the polymer is a polyether amide, (1) or (2) Styrenic resin composition of
(4) (C) Polylactic acid is less than 50% by weight based on the total amount of (A) styrene resin, (B) graft polymer, and (C) polylactic acid thermoplastic resin. The styrenic resin composition according to any one of (1) to (3),
(5) In any one of the above (1) to (4), the area ratio of the (B) graft polymer in the (C) polylactic acid is in the range of 10 to 90%. The styrenic resin composition according to the description,
(6) (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. It is a styrene resin composition of any one of said (1)-(5) characterized by the above-mentioned.

In the styrene resin composition of the present invention, a resin comprising (A) a styrene resin, (B) a graft polymer, (C) polylactic acid , and (D) a polymer having a volume resistivity of 10 ¹³ Ωcm or less. It is a composition, (D) Volume specific resistance value is 10 ¹³ Ωcm or less with respect to the total amount of (A) styrene resin, (B) graft polymer, and (C) polylactic acid thermoplastic resin. By setting the polymer to be in the range of 1 to 30% by weight, an environmentally low-load styrene resin composition having excellent impact resistance, heat resistance, and molding processability and having permanent antistatic properties is obtained. can get.

  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 (b) 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 monomers, 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 a carboxyl anhydride group, acrylic acid 2 -Hydroxyethyl, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydride methacrylate Xylpropyl, 2,3,4,5,6-pentahydroxyhexyl acrylate, 2,3,4,5,6-pentahydroxyhexyl methacrylate, 2,3,4,5-tetrahydroxypentyl acrylate, methacrylic acid 2,3,4,5-tetrahydroxypentyl, 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2-butene, trans-4-hydroxy-2-butene, 3- Vinyl monomers having a hydroxyl group such as hydroxy-2-methyl-1-propene, cis-5-hydroxy-2-pentene, trans-5-hydroxy-2-pentene, 4,4-dihydroxy-2-butene Glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, allyl glycidyl Vinyl monomers having an epoxy group such as ether, styrene-p-glycidyl ether and p-glycidyl styrene, acrylamide, methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propylmethacrylamide, aminoethyl acrylate, Propylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, N-vinyldiethylamine, N-acetylvinylamine, allylamine, methallylamine, N-methylallylamine , Vinyl monomers having amino groups such as p-aminostyrene and derivatives thereof, 2-isopropenyl-oxazoline, 2-vinyl-oxazoline , Vinyl monomers having an oxazoline group such as 2-acryloyl-oxazoline and 2-styryl-oxazoline, and the like can be used alone or in combination of two or more.

  (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.

  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.

As the (r) rubber polymer are preferable glass transition temperature is 0 ℃ below, using a diene rubber. Specific examples of these diene rubbers, polybutadiene, styrene - butadiene copolymer, styrene - butadiene block copolymer, acrylonitrile - butadiene copolymer, butyl acrylate - butadiene copolymer, blanking Tajien - methyl methacrylate copolymers, blanking Tajien - ethyl acrylate copolymer, et styrene - propylene - etc. diene copolymer. Among these diene rubbers , 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 or two are used. It can be used in a mixture of seeds 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.

  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.

  The (a) unsaturated carboxylic acid alkyl ester monomer used in the graft polymer (B) in the present invention is not particularly limited, but an acrylic acid 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 (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, acrylic 2-hydroxyethyl acid, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-methacrylic acid Droxypropyl, 2,3,4,5,6-pentahydroxyhexyl acrylate, 2,3,4,5,6-pentahydroxyhexyl methacrylate, 2,3,4,5-tetrahydroxypentyl acrylate, 2,3,4,5-tetrahydroxypentyl methacrylate, 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2-butene, trans-4-hydroxy-2-butene, Vinyl-based monomers having a hydroxyl group such as 3-hydroxy-2-methyl-1-propene, cis-5-hydroxy-2-pentene, trans-5-hydroxy-2-pentene, 4,4-dihydroxy-2-butene Glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, allyl glyceride Vinyl monomers having an epoxy group such as dil ether, styrene-p-glycidyl ether and p-glycidyl styrene, acrylamide, methacrylamide, N-methyl acrylamide, butoxymethyl acrylamide, N-propyl methacrylamide, aminoethyl acrylate Propylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, N-vinyldiethylamine, N-acetylvinylamine, allylamine, methallylamine, N-methyl Vinyl monomers having amino groups and derivatives thereof such as allylamine and p-aminostyrene, 2-isopropenyl-oxazoline, 2-vinyl-oxazo Examples thereof include vinyl monomers having an oxazoline group such as phosphorus, 2-acryloyl-oxazoline and 2-styryl-oxazoline, and these can be used alone or in combination of two or more.

  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. Graft ratio of the graft polymer, in order to obtain excellent resin composition balanced impact resistance and gloss, area by der 2 0-80 wt%. 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) a polylactic acid of the present invention, rather than limited to a particular polymer for the hydroxycarboxylic acid as a main component is used good Mashiku.

  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.

As a method for producing (C) a polylactic acid, Ki out using known polymerization methods can be employed direct polymerization method, ring-opening polymerization method through lactide and from lactate.

(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.

The styrenic resin composition of the present invention must contain (D) a polymer having a volume resistivity of 10 ¹³ Ωcm or less.

As the polymer (D) having a volume resistivity of 10 ¹³ Ωcm or less (hereinafter abbreviated as an antistatic polymer), an alkylene oxide residue having a number average molecular weight of 100 to 10,000, preferably 4 Examples include polymers containing a quaternary ammonium salt residue, a sulfonate residue, an ionomer residue, and the like. (1) Poly (alkylene oxide) glycol having a number average molecular weight of 1,000 to 10,000, (2) Polyether amide, polyether ester, or polyether ester amide containing alkylene oxide residues having a number average molecular weight of 200 to 10,000, (3) Vinyl containing alkylene oxide residues having a number average molecular weight of 100 to 10,000 Polymers, (4) vinyl polymers containing quaternary ammonium salt residues, (5) alkali metal ions Examples thereof include a polymer containing a nomer residue, and (6) a vinyl polymer containing an alkali metal salt residue of sulfonic acid.

  Specifically (1) Poly (alkylene oxide) glycol includes polyethylene glycol, polypropylene oxide glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, block or random copolymer of ethylene oxide and propylene oxide And a block or random copolymer of ethylene oxide and tetrahydrofuran.

  (2) Polyether amide, polyether ester, and polyether ester amide containing an alkylene oxide residue having a number average molecular weight of 200 to 10,000 include (2-a1) polyamide-forming component or (2-a2) polyester It is a block or graft copolymer obtained from a reaction between a forming component and (2-b) a diol containing an alkylene oxide residue having a number average molecular weight of 200 to 10,000.

  (2-a1) The polyamide-forming component is an aminocarboxylic acid having 6 or more carbon atoms, or a lactam or a diamine and dicarboxylic acid salt having 6 or more carbon atoms, such as ω-aminocaproic acid, ω-aminoenanthic acid, ω- Aminocaprylic acid, ω-aminopergonic acid, ω-aminocapric acid and 11-aminoundecanoic acid, aminocarboxylic acids such as 2-aminododecanoic acid, or lactols such as caprolactam, enanthractam, capryllactam and laurolactam and hexamethylenediamine Examples include salts of diamine-dicarboxylic acids such as adipate, hexamethylenediamine-sebacate and hexamethylenediamine-isophthalate, with caprolactam, 12-aminododecanoic acid, and hexamethylenediamine-adipate being particularly preferred. It is used well.

  In addition, (2-a2) polyester forming component includes dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4′-dicarboxylic acid. Acids, aromatic dicarboxylic acids such as diphenoxyethanedicarboxylic acid and sodium 3-sulfoisophthalate, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3- Alicyclic dicarboxylic acids such as dicarboxymethylcyclohexyl, 1,4-dicarboxymethylcyclohexyl and dicyclohexyl-4,4′-dicarboxylic acid and aliphatic such as succinic acid, oxalic acid, adipic acid, sebacic acid and decanedicarboxylic acid Dicarboxylic acids and aliphatic geo Ethylene glycol, 1,2- or 1,3-propylene glycol, 1,2-, 1,3-, 2,3-, or 1,4-butanediol, neopentyl glycol, 1,6-hexanediol In particular, dicarboxylic acids include terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, sebacic acid, and decanedicarboxylic acid and aliphatic diol as ethylene glycol, 1,2- or 1,3-propylene glycol. 1,4-butanediol is preferably used in view of polymerizability, color tone and physical properties.

  (2-b) Diols containing alkylene oxide residues having a number average molecular weight of 200 to 10,000 are poly (ethylene oxide) glycol, poly (1,2-propylene oxide) glycol, poly (1,3-propylene oxide) Examples thereof include glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, a block or random copolymer of ethylene oxide and propylene oxide, and a block or random copolymer of ethylene oxide and tetrahydrofuran. Among these, poly (ethylene oxide) glycol is particularly preferably used in terms of excellent antistatic properties.

  Examples of the diol containing an alkylene oxide residue having a number average molecular weight of 200 to 10,000 include those added to both ends such as hydroquinone, bisphenol A, and naphthalene.

  (2-b) The number average molecular weight of the diol containing an alkylene oxide residue is preferably in the range of 100 to 10,000, preferably 400 to 6,000 in terms of polymerizability and antistatic properties.

  The reaction between the (2-a1) polyamide-forming component or the (2-a2) polyester-forming component and the (2-b) diol containing an alkylene oxide residue results in (b) the terminal group of the diol containing an alkylene oxide residue. Depending on the reaction, ester reactions or amide reactions are conceivable.

  A third component such as dicarboxylic acid or diamine can be used depending on the above reaction.

  In this case, as the dicarboxylic acid component, terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, diphenoxyethanedicarboxylic acid And cycloaliphatic dicarboxylic acids typified by aromatic dicarboxylic acid represented by sodium 3-sulfoisophthalate, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid and dicyclohexyl-4,4′-dicarboxylic acid And aliphatic dicarboxylic acids typified by succinic acid, oxalic acid, adipic acid, sebacic acid and decanedicarboxylic acid, and particularly terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, sebacic acid, adipic acid and Decanedicarboxylic acid is polymerizable, color and resin Preferably used physical properties of the formed product.

  Moreover, tricarboxylic acid anhydrides, such as trimellitic acid anhydride, can also be used as needed.

  Examples of the diamine component include aromatic, alicyclic, and aliphatic diamines. Among them, the aliphatic diamine hexamethylenediamine is preferably used for economical reasons.

  (2) The content of the diol containing an alkylene oxide residue is 30 to 90% by weight, preferably 40 to 80% by weight, as structural units of polyether amide, polyether ester, and polyether ester amide.

  Further, (2) the degree of polymerization of polyetheramide, polyetherester, and polyetheresteramide is not particularly limited, but the relative viscosity (ηr) measured at 25 ° C. in a 0.5% concentration of orthochlorophenol solution Is preferably in the range of 1.1 to 4.0, preferably 1.5 to 2.5, because the final resin composition obtained has excellent mechanical properties and moldability.

  (3) Examples of the vinyl polymer containing an alkylene oxide residue having a number average molecular weight of 100 to 10,000 include polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate and the like, ethylene, propylene, 1-butene and the like. At least one selected from olefins, aromatic vinyl monomers such as styrene, hinyltoluene and α-methylstyrene, maleimide monomers such as maleimide and N-phenylmaleimide, and vinyl cyanide monomers such as acrylonitrile A copolymer containing at least one monomer selected from polyethylene glycol (meth) acrylate and methoxypolyethylene glycol (meth) acrylate in the above-mentioned (r) rubbery polymer. Graft copolymer obtained by polymerizing the body Coalescence and the like.

  The proportion of the monomer containing an alkylene oxide residue is preferably in the range of 5 to 40% by weight in terms of a vinyl polymer unit containing a poly (alkylene oxide) glycol residue.

  (4) As a vinyl polymer containing a quaternary ammonium salt residue, a monomer containing a quaternary ammonium base and an olefin monomer such as ethylene, propylene, 1-butene, styrene, hinyltoluene, α -Aromatic vinyl monomers such as methylstyrene, (meth) acrylic acid ester monomers such as methyl (meth) acrylate and butyl (meth) acrylate, maleimide monomers such as maleimide and N-phenylmaleimide And a copolymer with at least one monomer selected from vinyl cyanide monomers such as acrylonitrile. For example, “ROLEX” SA-70 and AS-170 manufactured by Daiichi Kogyo Seiyaku Co., Ltd. are commercially available.

  The proportion of the monomer containing a quaternary ammonium base is preferably in the range of 10 to 80% by weight in terms of a vinyl polymer unit containing a quaternary ammonium salt residue.

  (5) The polymer containing an alkali metal ionomer residue is selected from lithium, sodium, and potassium as a copolymer of an olefin monomer such as ethylene, propylene, 1-butene, and (meth) acrylic acid. In addition, a resin ionized with at least one kind of metal can be used.

  A polymer containing an ionomer residue having a metal ion concentration of 1.5 mol / kg or more is preferred.

  (6) As a vinyl polymer containing an alkali metal salt residue of sulfonic acid, a monomer having an alkali metal base of sulfonic acid, such as potassium styrenesulfonate, sodium styrenesulfonate, lithium styrenesulfonate and ethylene, Olefinic monomers such as poropylene and 1-butene, aromatic vinyl monomers such as styrene, hinyltoluene and α-methylstyrene, (meth) acrylic acid esters such as methyl (meth) acrylate and butyl (meth) acrylate And a copolymer with at least one vinyl monomer selected from maleimide monomers such as maleimide monomers, maleimide monomers such as N-phenylmaleimide, and vinyl cyanide monomers such as acrylonitrile. The proportion of the monomer having an alkali metal base of sulfonic acid is It is preferably in the range of 10 to 80 wt% in the vinyl polymer unit containing the alkali metal salt groups.

(D) The volume resistivity value of the antistatic polymer is 10 ¹³ Ωcm or less, preferably 5 × 10 ¹¹ Ωcm or less, and the lower limit is not limited, but 10 ⁵ Ωcm or more, particularly 10 ⁶ Ωcm or more is economical. preferable.

(D) If the volume resistivity value of the antistatic polymer exceeds 10 ¹³ Ωcm, the final resin composition obtained is insufficient in antistatic properties, which is not preferable.

  (D) The volume specific resistance value of the antistatic polymer is measured according to ASTM D257. When measuring from the resin composition, a molded product obtained by compression molding, injection molding or the like of the antistatic polymer separated from the resin composition is measured. As a simple method, the content and volume of conductor units such as poly (alkylene oxide) glycol residues, quaternary ammonium salt residues, sulfonate residues, ionomer residues, etc. in the antistatic polymer according to ASTM D257. It is possible to obtain a volume resistivity value of the polymer by creating a benchmark for the resistivity value and then analyzing the conductor unit content in any antistatic polymer.

The mixing ratio of the styrene resin composition of the present invention to (A) a styrene resin, (B) a graft polymer, (C), polylactic acid, and (D) a polymer having a volume resistivity of 10 ¹³ Ωcm or less. Is (A) styrene-based resin with respect to the total amount of (A) styrene-based resin, (B) graft polymer, and (C) polylactic acid , preferably 10% by weight or more, preferably 25 to 70% by weight, More preferably, it is 30 to 60% by 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, (C) the addition amount of polylactic acid is less than 85% by weight, preferably 65 to 10% by weight, more preferably 50 to 10% by weight, so that sufficient impact resistance and heat resistance can be obtained. Can be obtained. Furthermore, (D) the addition amount of the polymer having a volume resistivity of 10 ¹³ Ωcm or less is 1 with respect to the total amount of (A) styrene resin, (B) graft polymer, and (C) polylactic acid. Sufficient permanent antistatic properties can be obtained by adjusting the content to -30 wt%, preferably 5-20 wt%.

The styrene resin composition of the present invention has the above composition (A) styrene resin, (B) graft polymer, (C) polylactic acid , and (D) volume resistivity of 10 ¹³ Ωcm or less. It can be obtained by mixing a polymer. In the obtained styrene resin, (a) the unsaturated carboxylic acid alkyl ester unit is 1 to 90% by weight, preferably 10 to 80% by weight, based on the resin component. (B) 0.1 to 80% by weight of aromatic vinyl units, preferably 1 to 70% by weight, (c) 0 to 45% by weight of vinyl cyanide units, preferably 0 to 40% by weight, (d) Sufficient impact resistance and heat resistance can be obtained by setting the content in the range of 0 to 85% by weight, preferably 0 to 80% by weight, of other vinyl units copolymerizable with these.

The features of the styrene resin composition in the present invention are (A) styrene resin, (C) polylactic acid , (D) a polymer matrix having a volume resistivity of 10 ¹³ Ωcm or less, and dispersion in this matrix (B) the graft polymer domain, and at this time the domain (B) graft polymer (C) is present in the polylactic acid in an area ratio of 10 to 90%. Is preferred.

  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 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 (C) polylactic acid .

  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 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, and a carbodiimide compound, and among them, an epoxy compound and / or a carbodiimide compound are preferable. .

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 a natural organic filler.

  In the present invention, stabilizers (antioxidants, ultraviolet absorbers, weathering agents, etc.), lubricants, mold release agents, flame retardants, colorants including dyes or pigments, foaming agents, and the like are included within the scope of the present invention. Can be added.

  Examples of such antioxidants include phenolic antioxidants, phosphorus antioxidants, and thioether antioxidants. Of these, phenolic antioxidants are preferred.

  Specific examples of the phenolic antioxidant include 2,6-di-tert-butylphenol, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, NN′hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamide), 2,2'methylenebis (4-methyl-6-t-butylphenol), 4,4'methylenebis (2,6-di-t -Butylphenol), 4,4′butylidenebis (3-methyl-6-tert-butylphenol), 2,6-bis (2′-hydroxy-3′-tert-butyl-5′-methylbenzyl) 4-methylphenol, 1,1,3-tris (2′-methyl-5′-t-butyl-4′-hydroxyphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3′-5 ′ Di-t-butyl-4′-hydroxybenzyl) benzene, triethylene glycol bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], pentaerythrityltetrakis [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate], 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, etc. be able to. The general addition amount of these phenolic antioxidants is about 0.01 to 3% by weight and is used alone or in combination.

  In the present invention, other thermoplastic resins (for example, polyamide resin, aliphatic polycarbonate, aromatic polyester, polyethylene, polypropylene, polyvinyl chloride, polyphenylene sulfide resin, polyether ether ketone resin, as long as the object of the present invention is not impaired. , Polysulfone resin, polyethersulfone resin, polyarylate resin, polyphenylene oxide resin, polyacetal resin, polyimide resin, polyetherimide resin, chlorinated polyethylene resin, chlorinated polypropylene resin, aromatic and aliphatic polyketone resin, fluororesin, poly Vinylidene chloride resin, vinyl ester resin, polyurethane resin, cellulose acetate resin, polyvinyl alcohol resin, etc.) or thermosetting resin (eg phenol resin, melamine resin, Ester resin, silicone resin, epoxy resin, etc.) or soft thermoplastic resin (eg, ethylene / glycidyl methacrylate copolymer, polyester elastomer, polyamide elastomer, ethylene / propylene terpolymer, ethylene / butene-1 copolymer, etc.) One or more kinds may be further contained. By blending these resins, a molded product having excellent characteristics can be obtained.

  These additives can be blended at any stage for producing the styrenic resin composition of the present invention. For example, a method of simultaneously adding at least two components of a resin, or two components in advance. There are a method of adding the resin after melt kneading, and a method of adding the resin to one resin first and then melt-kneading and then blending the remaining resin.

The method for producing the styrene resin composition of the present invention is not particularly limited. For example, (A) styrene resin, (B) graft polymer, (C) polylactic acid , (D) volume resistivity value. A polymer exhibiting 10 ¹³ Ωcm or less and, if necessary, a crystal nucleating agent, a filler, a plasticizer, and other additives are blended in advance, and then uniformly melt-kneaded with a single-screw or twin-screw extruder above the melting point. And a method of removing the solvent after mixing in a solution is preferably used.

  In the present invention, the obtained styrenic 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. it can. 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. 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 part by weight 2,2′-azobisisobutyronitrile 0.4 part by weight After raising the reaction temperature to 65 ° C. over 30 minutes, 120 minutes The temperature was raised to 100 ° C. 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.

[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 temperature was raised to ° C. 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.

  <B-5> In the presence of 75 parts (converted to solid content) of polybutadiene latex (average rubber particle diameter 0.09 μm), 2 parts of MAA-BA copolymer is added as solid content and stirred at room temperature for 30 minutes. Thereafter, 1.5 parts of potassium oleate and 0.6 parts of sodium formaldehyde sulfoxylate were charged into the flask, the internal temperature was maintained at 70 ° C., and 13 parts of methyl methacrylate and 2 parts of n-butyl acrylate Then, a mixture of 0.03 part of cumene hydroxyperoxide was added dropwise over 1 hour and held for 1 hour. Thereafter, in the presence of the polymer obtained in the previous stage, as a second stage, a mixture of 17 parts of styrene and 0.034 parts of cumene hydroxyperoxide was added dropwise over 1 hour and then held for 3 hours. Thereafter, in the presence of the polymer obtained in the first stage and the second stage, as a third stage, a mixture of 3 parts of methyl methacrylate and 0.003 part of cumene hydroxyperoxide was added over 0.5 hours. After dropping, the polymerization was terminated after holding for 1 hour. After adding 0.5 part of butylated hydroxytoluene to the obtained graft copolymer latex, it was coagulated with sulfuric acid, washed and dried to obtain a powder. The graft ratio of the obtained graft copolymer was 26%, and the intrinsic viscosity of methyl ethyl ketone-soluble component was 0.26 dl / g.

(C) Polylactic acid <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.

[Reference Example 3] (D) Antistatic polymer <D-1> 40 parts of caprolactam, 56.3 parts of polyethylene glycol having a number average molecular weight of 2000, and 4.8 parts of terephthalic acid were added to an antioxidant (Irganox 1098). A transparent homogeneous solution was prepared by charging a reaction vessel equipped with a helical ribbon stirring blade together with 0.2 parts by weight and 0.1 part by weight of antimony trioxide, replacing the nitrogen and heating and stirring for 50 minutes while flowing a small amount of nitrogen at 260 ° C. Then, polymerization was carried out for 3 hours under the conditions of 260 ° C. and 0.5 mmHg or less to obtain a transparent polymer. The polymer was discharged onto a cooling belt in a gut shape and pelletized to prepare a polyether ether amide <D-1> in the form of pellets.

The obtained polyetheresteramide has a relative viscosity (ηr) of 2.01 measured at 25 ° C. in a 0.5% strength orthochlorophenol solution and a volume resistivity of 1 × 10 ⁹ Ωcm.

  <D-2> 90 parts of caprolactam, 9.4 parts of polyethylene glycol having a number average molecular weight of 2000, 0.8 parts of terephthalic acid, 0.2 parts by weight of an antioxidant (Irganox 1098) and 0.05 weight of antimony trioxide After charging into a reaction vessel equipped with a helical ribbon stirring blade together with the part, polyether ester amide <D-2> was prepared according to Reference Example <D-1>.

The obtained polyetheresteramide has a relative viscosity (ηr) of 2.11 measured at 25 ° C. in a 0.5% concentration of orthochlorophenol solution and a volume resistivity of 3 × 10 ¹³ Ωcm.

  <D-3> Caprolactam was pressure-polymerized to prepare polyamide <D-3>.

The obtained polyamide has a relative viscosity (ηr) of 2.10 measured at 25 ° C. in a 0.5% strength orthochlorophenol solution and a volume resistivity of 5 × 10 ¹⁴ Ωcm.

Crystal nucleating agent <E-1> “LMS300” (talc; inorganic crystal nucleating agent) manufactured by Fuji Talc Kogyo was used.

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

Filler <F-1> “CS3J948” (glass fiber) manufactured by Nittobo was used.

[Examples 1 to 3 , 5 to 14 , Comparative Examples 1 to 5 ]
After dry blending the raw materials having the compositions shown in Tables 1 and 2, melt mixing pelletizing was performed using a twin screw extruder (PCM-30 manufactured by Ikegai Kogyo Co., Ltd.) set at an extrusion temperature of 220 ° C.

The pellets obtained in Examples 1 to 10 and Comparative Examples 1 to 5 were obtained by injection molding 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, each characteristic was evaluated with the following measuring methods. The pellets obtained in Examples 11 to 14 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.

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

  [Heat resistance]: The heat distortion temperature was measured according to ASTM D648 (load: 1.82 MPa).

[Antistatic property] Surface specific resistance value: Measured under the following conditions using a disc of 2 mmt x 40 mmφ. For the measurement, a super insulation resistance meter SM-10 manufactured by Toa Denpa Kogyo Co., Ltd. was used.
(1) Immediately after molding, after washing with an aqueous solution of the detergent “Mama Royal” (manufactured by Lion Corporation), followed by thorough washing with distilled water, the surface moisture was removed, and the room temperature was 23 ° C. and the humidity was 50% RH. Measured below.
(2) After molding, leave it at 23 ° C. and 50% RH for 100 days, and then wash with an aqueous solution of detergent “Mama Royal” (manufactured by Lion Corporation), and then thoroughly wash with distilled water. Then, the measurement was performed at room temperature of 23 ° C. and humidity of 50% RH.

  [Area ratio]: For a molded product obtained by injection molding, a sample obtained by dyeing a styrene resin and a graft polymer by an osmium block dyeing method and then cutting out an ultrathin section is 6000 times with a transmission electron microscope. The cross section was enlarged and observed. Further expanded by a factor of 4, (C) the area (X) of the dispersed graft polymer in the aliphatic polyester and (A) the area (Y) of the dispersed graft polymer in the styrene resin were cut out from the photograph and weighted. The area ratio was determined according to the formula (X) / ((X) + (Y)).

  Tables 1 and 2 show the measurement results of the impact resistance, heat resistance, antistatic property, and area ratio of the graft polymer present in the aliphatic polyester for each sample, respectively.

From Examples 1 to 9 , the styrene-based resin composition of the present invention significantly improves impact resistance by adding a styrene-based resin and a graft polymer to polylactic acid alone (Comparative Example 2). In addition, it has a practical heat-resistant temperature, a low surface resistivity, and the surface resistivity does not change even when the molded product is cleaned or changes over time. It can be demonstrated.

In particular, Examples 1 to 3 and Comparative Example 5 indicate that the impact resistance can be improved as the proportion of the graft polymer present in the polylactic acid increases.

  On the other hand, it can be seen from Comparative Examples 3 and 4 that when the styrenic resin is out of the scope of the present invention, the impact resistance can be greatly improved, but the heat resistance is low, so that it is not practical.

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

Claims (6)

(A) a styrene resin (not including those which are obtained by grafting polymerization of aromatic vinyl units of the rubbery polymer), (B) graft polymer, polylactic acid, and (D) volume resistivity (C) A resin composition comprising a polymer exhibiting 10 ¹³ Ωcm or less, with respect to the total amount of (A) styrene resin, (B) graft polymer, and (C) polylactic acid thermoplastic resin (D ) A styrenic resin composition characterized in that the polymer having a volume resistivity of 10 ¹³ Ωcm or less is in the range of 1 to 30% by weight,
(B) The graft polymer has a graft ratio of 20 to 80% by weight,
(R) 10 to 80% by weight of diene rubber, (a) 20 to 90% by weight of unsaturated carboxylic acid alkyl ester unit, (b) 0 to 70% by weight of aromatic vinyl unit, (c) vinyl cyanide A styrene resin composition which is a graft polymer obtained by graft polymerization of 0 to 50% by weight of system units and (d) 0 to 70% by weight of other vinyl units copolymerizable therewith. (D) A polymer having a volume resistivity of 10 ¹³ Ωcm or less contains a residue selected from alkylene oxide residues, quaternary ammonium salt residues, and alkali metal ionomer residues having an average number molecular weight of 100 to 10,000. The styrenic resin composition according to claim 1, wherein the styrenic resin composition is a polymer. (D) The styrenic resin composition according to claim 1 or 2, wherein the polymer having a volume resistivity of 10 ¹³ Ωcm or less is a polyether amide, a polyether ester, or a polyether ester amide. . The (C) polylactic acid is less than 50% by weight based on the total amount of the thermoplastic resin of (A) styrenic resin, (B) graft polymer, and (C) polylactic acid. The styrenic resin composition according to any one of 1 to 3. The styrene-based resin composition according to any one of claims 1 to 4, wherein the area ratio of (B) the graft polymer in (C) polylactic acid is in the range of 10 to 90%. object. (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 6. The styrenic resin according to claim 1, wherein the styrenic resin is copolymerized by weight% and (d) 0 to 99% by weight of other vinyl units copolymerizable therewith. Styrenic resin composition.