JP2010143995A - Polyester resin composition and molded article thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin composition excellent in mechanical strength and elastic modulus and maintaining toughness, and to provide a molded article thereof. <P>SOLUTION: The composition is obtained by compounding, based on (A) 100 pts.wt. of a polybutylene terephthalate resin, (B) 5-100 pts.wt. of a polylactic acid resin having melting point of 130-150°C and crystal melting heat of 0-10 J/g, and (C) 0-5 pts.wt. of a hydrolysis resistance modifier. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polyester resin composition having excellent mechanical strength and elastic modulus and retaining toughness, and a molded article thereof.

  Polybutylene terephthalate resin has excellent mechanical properties, electrical properties, heat resistance, weather resistance, water resistance, chemical resistance, and solvent resistance, so it can be used as an engineering plastic for automotive parts, electrical / electronic parts, etc. It is widely used for applications.

  On the other hand, in recent years, as environmental and resource issues, socially demanded countermeasures to increase greenhouse gases such as carbon dioxide and the depletion of fossil resources in the future, biobased plastics such as polylactic acid resin have been studied. It is becoming active. In addition, for plastics based on fossil raw materials, studies on blending bio-based plastics are widely conducted.

With respect to polybutylene terephthalate resin, studies on blending bio-based plastics from the same viewpoint are being conducted. For example, Patent Document 1 proposes a polybutylene terephthalate resin composition containing a polybutylene terephthalate resin and a polylactic acid resin, and the content of the polylactic acid resin is 5 to 50% by mass based on the total amount of the composition. ing. Patent Document 2 proposes a polybutylene terephthalate resin composition containing 100 parts by weight of a polybutylene terephthalate resin having a predetermined terminal carboxyl group concentration and 1 to 99 parts by weight of a polylactic acid-based resin. However, any of the preceding examples has been insufficiently studied for achieving both mechanical strength / elastic modulus and toughness, particularly for improving tensile elongation (fracture strain).
JP 2006-008868 A (Claims) JP 2006-063199 A (Claims)

  An object of the present invention is to provide a polyester resin composition having excellent mechanical strength and elastic modulus and retaining toughness, and a molded product thereof.

  As a result of intensive studies to solve the above problems, the present inventors have obtained a polyester resin composition that can achieve the above object and a molded product thereof by combining a polybutylene terephthalate resin and a specific polylactic acid resin. As a result, the present invention has been completed.

  That is, the present invention relates to (A) 100 parts by weight of a polybutylene terephthalate resin, (B) 5 to 100 parts by weight of a polylactic acid resin having a melting point of 130 to 150 ° C. and a crystal melting heat of 0 to 10 J / g, A polyester resin composition comprising 0 to 5 parts by weight of a hydrolyzability improving agent and a molded product thereof.

  The polyester resin composition of the present invention is excellent in mechanical strength and elastic modulus and excellent in toughness. The polyester resin composition of the present invention is suitable for injection molded articles related to automobile parts, electrical / electronic parts, sundries, stationery and the like.

(A) Polybutylene terephthalate resin Polybutylene terephthalate resin (PBT resin) is terephthalic acid (terephthalic acid or its ester-forming derivative), C4 alkylene glycol (1,4-butanediol) and / or its ester. It is a thermoplastic resin having a forming derivative as at least a polymerization component.

  Examples of the polybutylene terephthalate resin include a homopolyester (polybutylene terephthalate) and / or a copolyester (a butylene terephthalate copolymer, a polybutylene terephthalate copolyester, or a modified PBT resin) containing butylene terephthalate as a main component. .

  Examples of the copolymerizable monomer in the copolyester (hereinafter sometimes simply referred to as a copolymerizable monomer) include dicarboxylic acid components excluding terephthalic acid, diols excluding 1,4-butanediol, oxycarboxylic acid components, and lactones. Ingredients and the like. The copolymerizable monomers can be used alone or in combination of two or more.

  Dicarboxylic acids (or dicarboxylic acid components or dicarboxylic acids) include aliphatic dicarboxylic acids (eg, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, C4-40 dicarboxylic acid such as hexadecane dicarboxylic acid and dimer acid, preferably C4-14 dicarboxylic acid), alicyclic dicarboxylic acid component (for example, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, highmic acid, etc.) C8-12 dicarboxylic acid), aromatic dicarboxylic acid components excluding terephthalic acid (for example, naphthalenedicarboxylic acid such as phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 4, 4'-Diphenoki Ether dicarboxylic acids, 4,4′-diphenyl ether dicarboxylic acids, 4,8′-diphenylmethane dicarboxylic acids, C8-16 dicarboxylic acids such as 4,4′-diphenyl ketone dicarboxylic acids), or reactive derivatives thereof (for example, lower Alkyl esters (phthalic acids such as dimethylphthalic acid and dimethylisophthalic acid or C1-4 alkyl esters of isophthalic acid), derivatives such as acid chlorides and acid anhydrides that can form esters), and the like. Furthermore, if necessary, a polyvalent carboxylic acid such as trimellitic acid or pyromellitic acid or an ester-forming derivative thereof (such as an alcohol ester) may be used in combination. When such a polyfunctional compound is used in combination, a branched polybutylene terephthalate resin can also be obtained.

  Diols (or diol components or diols) include, for example, aliphatic alkanediols other than 1,4-butanediol [for example, alkanediols (for example, ethylene glycol, trimethylene glycol, propylene glycol, neopentyl glycol, hexanediol ( 1,6-hexanediol, etc.), octanediol (1,3-octanediol, 1,8-octanediol, etc.), lower alkanediols such as decanediol, preferably linear or branched C2-12 alkanediols More preferably linear or branched C2-10 alkanediols, etc.); (poly) oxyalkylene glycols (e.g. glycols having a plurality of oxy C2-4 alkylene units, e.g. diethylene glycol, dipropylene Glycol, ditetramethylene glycol, triethylene glycol, tripropylene glycol, polytetramethylene glycol, etc.)], alicyclic diols (eg 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol) A), aromatic diols [for example, dihydroxy C6-14 arenes such as hydroquinone, resorcinol, naphthalenediol; biphenols (such as 4,4′-dihydroxybiphenyl); bisphenols; xylylene glycol, etc.], and these And reactive derivatives (for example, ester-forming derivatives such as alkyl, alkoxy or halogen-substituted products). Furthermore, if necessary, a polyol such as glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, or an ester-forming derivative thereof may be used in combination. When such a polyfunctional compound is used in combination, a branched polybutylene terephthalate resin can also be obtained.

  Examples of the bisphenols include bis (4-hydroxyphenyl) methane (bisphenol F), 1,1-bis (4-hydroxyphenyl) ethane (bisphenol AD), 1,1-bis (4-hydroxyphenyl) propane, , 2-bis (4-hydroxyphenyl) propane (bisphenol A), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2- Bis (hydroxyaryl) C1 such as bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) hexane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane 6 alkanes, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-H Bis (hydroxyaryl) C4-10cycloalkane such as loxyphenyl) cyclohexane, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenyl Examples thereof include ketones and alkylene oxide adducts thereof. Examples of the alkylene oxide adduct include C2-3 alkylene oxide adducts of bisphenols (eg, bisphenol A, bisphenol AD, bisphenol F), such as 2,2-bis [4- (2-hydroxyethoxy) phenyl] propane, Examples include diethoxylated bisphenol A, 2,2-bis [4- (2-hydroxypropoxy) phenyl] propane, and dipropoxylated bisphenol A. The added mole number of alkylene oxide (C2-3 alkylene oxide such as ethylene oxide and propylene oxide) is about 1 to 10 moles, preferably about 1 to 5 moles with respect to each hydroxy group.

  Examples of oxycarboxylic acids (or oxycarboxylic acid components or oxycarboxylic acids) include oxycarboxylic acids such as oxybenzoic acid, oxynaphthoic acid, hydroxyphenylacetic acid, glycolic acid, and oxycaproic acid, or derivatives thereof. . Lactones include C3-12 lactones such as propiolactone, butyrolactone, valerolactone, caprolactone (eg, ε-caprolactone, etc.), and the like.

  Of these copolymerizable monomers, diols [C2-6 alkylene glycol (such as linear or branched alkylene glycol such as ethylene glycol, trimethylene glycol, propylene glycol, hexanediol), preferably 2 are preferable. Polyoxy C2-4 alkylene glycol having about -4 oxyalkylene units (such as diethylene glycol), bisphenols (such as bisphenols or alkylene oxide adducts thereof)], dicarboxylic acids [C6-12 aliphatic dicarboxylic acids (adipic acid, pimelin) Acid, suberic acid, azelaic acid, sebacic acid, etc.), asymmetric aromatic dicarboxylic acids in which the carboxyl group is substituted at the asymmetric position of the arene ring, 1,4-cyclohexanedimethanol, etc.].

  Among these compounds, aromatic compounds such as alkylene oxide adducts of bisphenols (particularly bisphenol A), and asymmetric aromatic dicarboxylic acids [phthalic acid, isophthalic acid and reactive derivatives thereof (lower alkyl such as dimethylisophthalic acid) Ester) and the like.

  The polybutylene terephthalate resin is preferably a homopolyester (polybutylene terephthalate) and / or a copolymer (polybutylene terephthalate copolyester). The polybutylene terephthalate resin usually has a proportion (modification amount) of a copolymerizable monomer. It may be 0-30 mol%, preferably 0-25 mol% of a homo or copolyester (particularly a homopolyester).

  In addition, when a homopolyester (polybutylene terephthalate) and a copolymer (copolyester) are used in combination, the proportion of the homopolyester and the copolyester is such that the proportion of the copolymerizable monomer is relative to the total monomers. The range is about 0.1 to 30 mol% (preferably 1 to 25 mol%, more preferably 5 to 25 mol%). Usually, the former / the latter = 99/1 to 1/99 (weight ratio), Preferably, it can be selected from a range of about 95/5 to 5/95 (weight ratio), more preferably about 90/10 to 10/90 (weight ratio).

  The intrinsic viscosity (IV) of the polybutylene terephthalate resin is preferably 1.4 dL / g or less, and more preferably 1.2 dL / g or less. Further, polybutylene terephthalate resins having different intrinsic viscosities may be blended. The intrinsic viscosity (IV) can be measured, for example, in o-chlorophenol at a temperature of 35 ° C. When a polybutylene terephthalate resin having an intrinsic viscosity in such a range is used, it is easy to efficiently achieve sufficient toughness and a reduced melt viscosity. If the intrinsic viscosity is too large, the melt viscosity at the time of molding becomes high, and in some cases, there is a possibility of causing poor resin flow and poor filling in the molding die.

As the polybutylene terephthalate resin, a commercially available product may be used, and terephthalic acid or a reactive derivative thereof and 1,4-butanediol and a monomer that can be copolymerized if necessary are used in a conventional manner, for example, transesterification, You may use what was manufactured by copolymerization (polycondensation) by the direct esterification method etc. Further, the production may be performed in any state of a molten state, a solid phase state, and a solution state.
(B) Polylactic acid resin The polylactic acid resin used in the present invention is a polymer mainly composed of L-lactic acid and / or D-lactic acid, and a conventionally known polymerization method can be used as a production method. Examples thereof include a direct polymerization method from lactic acid and a ring-opening polymerization method via lactide.

  The polylactic acid resin used in the present invention may contain a copolymerization component other than lactic acid. Other monomer units include ethylene glycol, propylene glycol, butanediol, heptanediol, hexanediol, octanediol, nonanediol, decanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, glycerin, pentane. Glycol compounds such as erythritol, polyethylene glycol, polypropylene glycol and polytetramethylene glycol, oxalic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, malonic acid, glutaric acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalate Acid, naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, 4,4'-diphenyl ether dicarboxylic acid, 5-sodium sulfoisophthalic acid, 5- Dicarboxylic acids such as trabutylphosphonium isophthalic acid, glycolic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxybenzoic acid and other hydroxycarboxylic acids, and caprolactone, valerolactone, propiolactone, undecalactone And lactones such as 1,5-oxepan-2-one. These copolymer components are preferably 0 to 30 mol%, particularly preferably 0 to 10 mol%, based on all monomers of the polylactic acid resin.

  The polylactic acid resin used in the present invention is a kind selected from polyglycolic acid, polycaprolactone, polybutylene succinate, polyethylene succinate, polybutylene adipate terephthalate, polybutylene succinate terephthalate and the like as a part of its components. Alternatively, a mixture of two or more resins with polylactic acid may be used.

  In addition, the intrinsic viscosity (IV) of the polylactic acid resin used for this invention is not specifically limited, It can use in a conventionally well-known range.

  The polylactic acid resin used in the present invention needs to have thermal characteristics such that the melting point (peak temperature) of differential scanning calorimetry (DSC measurement) is 130 to 150 ° C. and the heat of crystal melting is 0 to 10 J / g. Here, the melting point and the heat of crystal fusion were measured by sealing a sample cut out from the polylactic acid resin in an aluminum pan, holding at 200 ° C. for 1 minute, cooling to −10 ° C./min to room temperature, and subsequently 10 ° C. It is a value calculated from the crystal melting peak detected when the temperature is raised at / min. When the melting point of the polylactic acid resin used in the present invention is lower than 130 ° C., the characteristics of the polybutylene terephthalate resin may be impaired. When the melting point is higher than 150 ° C., the toughness represented by tensile elongation (fracture strain) is present. Since it falls, neither is preferable. In particular, the melting point of the polylactic acid resin is preferably 135 to 150 ° C. In addition, when the heat of crystal fusion of the polylactic acid resin exceeds 10 J / g, the toughness typified by tensile elongation (fracture strain) decreases, which is not preferable. In particular, the heat of crystal melting of the polylactic acid resin is preferably 0 to 5 J / g.

  Furthermore, the polylactic acid resin used in the present invention preferably has a crystallization heat amount of 0 to 2 J / g and a cold crystallization heat amount of 0 to 5 J / g as measured by DSC. The amount of crystallization heat is calculated from the crystallization peak detected when the sample cut from the polylactic acid resin is sealed in an aluminum pan, kept at 200 ° C. for 1 minute, and then cooled to room temperature at −10 ° C./min. To do. Further, the cold crystallization heat quantity is calculated from the cold crystallization peak detected when the temperature is subsequently raised at 10 ° C./min. When the crystallization heat amount of the polylactic acid resin exceeds 2 J / g and the cold crystallization heat amount exceeds 5 J / g, the toughness represented by tensile elongation (fracture strain) decreases, which is not preferable.

  In the present invention, the proportion of (B) polylactic acid resin is 5 to 100 parts by weight, preferably 10 to 80 parts by weight, particularly preferably 20 to 70 parts by weight, based on 100 parts by weight of (A) polybutylene terephthalate resin. is there. If the amount is less than 5 parts by weight, sufficient mechanical strength may not be improved. If the amount exceeds 100 parts by weight, the properties of the polybutylene terephthalate resin may be impaired.

As a particularly preferable polylactic acid resin used in the present invention, a commercially available product can be used, and REVODE (registered trademark) manufactured by Zhejiang Haisei Biological Materials can be mentioned.
(C) Hydrolysis resistance improver In the present invention, a hydrolysis resistance improver can be used in combination. Examples of the hydrolysis resistance improver include one or more selected from conventionally known compounds such as carbodiimide compounds and epoxy compounds.

  A carbodiimide compound is a compound having a carbodiimide group (—N═C═N—) in the molecule. As the carbodiimide compound, any of an aliphatic carbodiimide compound having an aliphatic main chain, an alicyclic carbodiimide compound having an alicyclic main chain, and an aromatic carbodiimide compound having an aromatic main chain can be used. A carbodiimide compound can be used individually or in combination of 2 or more types.

  The aliphatic and alicyclic carbodiimide compounds are compounds having a carbodiimide bond in the molecule (polymer main chain), and are obtained by reacting any aliphatic and alicyclic isocyanate compounds. Examples of the starting isocyanate include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, polyfunctional aliphatic isocyanate, block polyfunctional aliphatic isocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and water of aromatic isocyanate. An additive etc. are mentioned, These 1 type (s) or 2 or more types can be used preferably. Specific examples include diisopropylcarbodiimide, dioctyldecylcarbodiimide, dicyclohexylcarbodiimide, and the like.

Examples of aromatic carbodiimide compounds include diphenylcarbodiimide, di-2,6-dimethylphenylcarbodiimide, N-triyl-N′-phenylcarbodiimide, di-p-nitrophenylcarbodiimide, di-p-aminophenylcarbodiimide, and di-p-. Hydroxyphenylcarbodiimide, di-p-chlorophenylcarbodiimide, di-p-methoxyphenylcarbodiimide, di-3,4-dichlorophenylcarbodiimide, di-2,5-dichlorophenylcarbodiimide, di-o-chlorophenylcarbodiimide, p-phenylene-bis-di-o-triylcarbodiimide, p-phenylene-bis-dicyclohexylcarbodiimide, p-phenylene-bis-di-p-chlorophenylcarbodiimide, ethylene-bis-diphenyl carbonate Mono or dicarbodiimide compounds such as rubodiimide and poly (4,4′-diphenylmethanecarbodiimide), poly (3,5′-dimethyl-4,4′-biphenylmethanecarbodiimide), poly (p-phenylenecarbodiimide), poly (m -Phenylenecarbodiimide), poly (3,5'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly (naphthylenecarbodiimide), poly (1,3-diisopropylphenylenecarbodiimide), poly (1-methyl-3,5 Examples include polycarbodiimide compounds such as -diisopropylphenylenecarbodiimide), poly (1,3,5-triethylphenylenecarbodiimide), and poly (triisopropylphenylenecarbodiimide), and these can be used in combination of two or more. Of these, di-2,6-dimethylphenylcarbodiimide, poly (4,4′-diphenylmethanecarbodiimide), poly (phenylenecarbodiimide), poly (triisopropylphenylenecarbodiimide) and the like are particularly preferably used.

  Examples of the epoxy compound include polyfunctional epoxy compounds such as an epoxy resin and a vinyl copolymer having a glycidyl group. An epoxy compound can be used individually or in combination of 2 or more types.

  Examples of the epoxy resin include glycidyl ether type epoxy resin, glycidyl ester type epoxy resin (diglycidyl phthalate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, dimethyl glycidyl phthalate, dimethyl glycidyl hexahydrophthalate, dimer acid glycidyl ester, aroma Tic diglycidyl ester, cycloaliphatic diglycidyl ester, etc.), glycidyl amine type epoxy resin (tetraglycidyl diaminodiphenylmethane, triglycidyl-paraaminophenol, triglycidyl-metaaminophenol, diglycidyl toluidine, tetraglycidyl metaxylylenediamine, Diglycidyl tribromoaniline, tetraglycidyl bisaminomethylcyclo Xanthine), heterocyclic epoxy resins (triglycidyl isocyanurate, hydantoin type epoxy resins, etc.), cyclic aliphatic epoxy resins (vinylcyclohexene dioxide, dicyclopentadiene oxide, alicyclic diepoxy acetals, alicyclic dice) Epoxy adipate, alicyclic diepoxycarboxylate, etc.), epoxidized polybutadiene and the like.

  Examples of glycidyl ether type epoxy resins include glycidyl ethers of polyhydroxy compounds [bisphenol type epoxy resins (for example, bisphenol A type, bisphenol AD type, or bisphenol F type epoxy resins), and aromatic polyhydroxy compounds such as resorcinol type epoxy resins. Glycidyl ethers; aliphatic epoxy resins (such as glycidyl ethers of alkylene glycols and polyoxyalkylene glycols), novolak type epoxy resins (such as phenol nopolac type and cresol novolac type epoxy resins), and the like.

  Particularly preferred epoxy resins are aromatic epoxy resins (bisphenol type epoxy resins, resorcin type epoxy resins, novolac type epoxy resins, etc.) and cycloaliphatic epoxy resins. Among them, glycidyl ether type aromatic epoxy resins, for example, bisphenol type epoxy resins, novolak type epoxy resins and the like can be mentioned.

  A vinyl copolymer having a glycidyl group is composed of a copolymer of a polymerizable monomer having a glycidyl group (such as a vinyl monomer having a glycidyl group) and another copolymerizable monomer. The

  The polymerizable monomer having a glycidyl group has at least one polymerizable group (such as an ethylenically unsaturated bond (such as a vinyl group) or an acetylene bond) together with the glycidyl group. Examples of such monomers include glycidyl ethers such as allyl glycidyl ether, vinyl glycidyl ether, chalcone glycidyl ether, and 2-cyclohexene-1-glycidyl ether; glycidyl (meth) acrylate, glycidyl maleate, glycidyl itaconate, vinyl benzoate Acid glycidyl ester, allylbenzoic acid glycidyl ester, cinnamic acid glycidyl ester, cinnamylidene acetic acid glycidyl ester, dimer acid glycidyl ester, epoxidized stearyl alcohol and acrylic acid or methacrylic acid ester, cycloaliphatic glycidyl ester (cyclohexene-4, Glycidyl or epoxy esters (especially glycidyl esters of α, β-unsaturated carboxylic acids) such as 5-diglycidyl carboxylate) Epoxidized unsaturated linear or cyclic olefins such as epoxy hexene and limonene oxide; N- [4- (2,3-epoxypropoxy) -3,5-dimethylbenzyl] acrylamide and the like. Of these monomers, vinyl monomers having a glycidyl group, for example, glycidyl esters of α, β-unsaturated carboxylic acids are preferred. These glycidyl group-containing polymerizable monomers can be used alone or in combination of two or more.

  Examples of the other copolymerizable monomer that can be copolymerized with a polymerizable monomer having a glycidyl group include olefin monomers (such as α-olefins such as ethylene, propylene, butene, and hexene), and diene monomers. Polymers (conjugated dienes such as butadiene and isoprene), aromatic vinyl monomers (styrene monomers such as styrene, α-methylstyrene, vinyltoluene), acrylic monomers ((meth) acrylic) (Meth) acrylic acid alkyl esters such as acid and methyl methacrylate, acrylonitrile, etc.), vinyl esters (vinyl acetate, vinyl propionate, etc.), vinyl ethers and the like. The copolymerizable monomer is preferably a monomer having an α, β-unsaturated double bond. These copolymerizable monomers can be used alone or in combination of two or more. Of the copolymerizable monomers, olefin monomers and acrylic monomers (such as (meth) acrylic acid and (meth) acrylic acid ester) are preferable.

  In the present invention, the proportion of (C) hydrolysis resistance improver is 0 to 5 parts by weight, preferably 0 to 4 parts by weight, per 100 parts by weight of (A) polybutylene terephthalate resin. If it exceeds 5 parts by weight, the properties of the polybutylene terephthalate resin may be impaired.

  In addition, the polyester resin composition of this invention may contain other resin (thermoplastic resin etc.) and various additives and fillers in the range which does not impair the effect of this invention as needed. Examples of other resins include polyester resins other than polybutylene terephthalate resins and polylactic acid resins, polyolefin resins, polystyrene resins, polyamide resins, polyacetals, polyarylene oxides, polyarylene sulfides, and fluororesins. Further, copolymers such as acrylonitrile-styrene resin, acrylonitrile-butadiene-styrene resin, and ethylene-ethyl acrylate resin are also exemplified. These other resins may be used alone or in combination of two or more.

  As additives and fillers, conventionally known inorganic fillers, organic fillers, stabilizers (antioxidants, ultraviolet absorbers, heat stabilizers, etc.), antistatic agents, flame retardants, flame retardant aids Examples thereof include thermoplastic elastomers, colorants (such as dyes and pigments), lubricants, plasticizers, lubricants, mold release agents, crystal nucleating agents, anti-dripping agents (anti-dripping agents), and the like. These additives can be used alone or in combination of two or more. In addition, mixing a part of the resin component as a fine powder with other components and adding it is a preferable method for uniformly blending these components.

  The polyester resin composition of the present invention can be easily obtained by a conventional molding method such as injection molding, extrusion molding, compression molding, blow molding, vacuum molding, rotational molding, gas injection molding, film molding (inflation method, T-die method). It can be molded and a molded product can be obtained efficiently. Of these, injection molding is particularly preferred.

  A molded product (or molded product) can be produced by molding the resin composition composed of each component by a conventional method. For example, in the molded product of the present invention, i) a method in which each component is mixed and then kneaded and extruded by an extruder (uniaxial or biaxial extruder) to prepare pellets, and then molded, ii) pellets having a different composition once (Master batch) is prepared, and the pellets are mixed (diluted) in a predetermined amount and subjected to molding, and after molding, a molded product having the desired composition is obtained. Iii) One or more of each component is directly charged into a molding machine Any method can be used. Moreover, it is preferable to pre-dry before melt-kneading and molding.

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

Examples 1-7, Comparative Examples 1-3
Each resin composition was dry blended at the mixing ratio shown in Tables 1 and 2, and melt-kneaded at 250 ° C. using a twin-screw extruder (manufactured by Nippon Steel Co., Ltd.) having a 30 mmφ screw, then pelletized and tested. A piece was made and each evaluation was performed. The results are shown in Tables 1 and 2.

In addition, the detail of the used component and the measuring method of physical property evaluation are as follows.
(A) Polybutylene terephthalate resin (A-1) Polybutylene terephthalate (Intrinsic viscosity IV = 1.14 dL / g, manufactured by Wintech Polymer Co., Ltd.)
(A-2) Polybutylene terephthalate (Intrinsic viscosity IV = 0.875 dL / g, manufactured by Wintech Polymer Co., Ltd.)
(B) Polylactic acid resin (B-1) REVODE 101-B (manufactured by Zhejiang Haisei Biomaterials Co., Ltd.) Melting point 144.0 ° C., heat of crystal fusion 3.9 J / g, heat of crystallization 0.0 J / g (detection Not), cold crystallization heat amount 0.0J / g (not detected)
(B-2) U'z S-12 (manufactured by Toyota Motor Corporation) Melting point: 175.9 ° C., heat of crystal melting: 27.7 J / g, heat of crystallization: 3.5 J / g (crystallization temperature: 103.0 ° C. ), Heat of cold crystallization 9.7 J / g (cold crystallization temperature 113.0 ° C.)
(B-3) U'z S-32 (manufactured by Toyota Motor Corporation) Melting point 174.9 ° C., heat of crystal melting 29.4 J / g, heat of crystallization 3.2 J / g (crystallization temperature 100.6 ° C. ), Heat of cold crystallization 9.4 J / g (cold crystallization temperature 113.2 ° C.)
The melting point, the heat of crystal fusion, the heat of crystallization, and the heat of cold crystallization are all values obtained by DSC measurement described later.
(C) Hydrolysis resistance improver (C-1) Carbodiimide compound (“Carbodilite LA-1” manufactured by Nisshinbo Industries, Inc.)
(C-2) Carbodiimide compound (Rhein Chemie Japan Co., Ltd. “STABAKZOL P”)
(C-3) Glycidyl methacrylate homopolymer, average molecular weight 12000 (“Marproof G-01100” manufactured by NOF Corporation)
(C-4) Glycidyl methacrylate / acryl = 1/1 copolymer, average molecular weight 10,000 (“Marproof G-0150M” manufactured by NOF Corporation)
-(D) Others As a mold release agent, (D-1) montanic acid ester wax ("Ricolb WE-1" manufactured by Clariant Japan Co., Ltd.) is added to all Examples and Comparative Examples.
<Melting point, heat of crystal melting (DSC measurement)>
The sample cut out from the pellet (polylactic acid resin) was sealed in an aluminum pan, held at 200 ° C. for 1 minute using a DSC device (DSC7 manufactured by PerkinElmer), and then cooled to −10 ° C./min to room temperature. Subsequently, the melting point (peak temperature) and the heat of crystal melting were calculated from the crystal melting peak detected when the temperature was raised at 10 ° C./min.

<Crystalization heat, cold crystallization heat (DSC measurement)>
The sample cut out from the pellet (polylactic acid resin) was sealed in an aluminum pan, and kept at 200 ° C. for 1 minute using a DSC device (Perkin Elmer DSC7), and then cooled to −10 ° C./min to room temperature. The amount of heat of crystallization was calculated from the crystallization peak detected at the time, and then the amount of heat of cold crystallization was calculated from the cold crystallization peak detected when the temperature was raised at 10 ° C./min.
<Tensile strength, tensile elongation (fracture strain)>
The obtained pellets (polyester resin composition) were dried at 140 ° C. for 3 hours, and then a tensile test piece was prepared by injection molding at a molding temperature of 250 ° C. and a mold temperature of 80 ° C., as defined in ISO527-1,2. It was evaluated according to the evaluation criteria.
<Bending strength, flexural modulus>
The obtained pellet (polyester resin composition) was dried at 140 ° C. for 3 hours, then injection molded at a molding temperature of 250 ° C. and a mold temperature of 80 ° C. to produce a bending test piece, and the evaluation criteria defined in ISO178 It evaluated according to.

  From the results shown in Tables 1 and 2, the polyester resin composition of the present invention using (B) a polylactic acid resin having a melting point of 130 to 150 ° C. and a crystal melting heat of 0 to 10 J / g has a tensile strength, a bending strength and a bending strength. The elastic modulus is higher than that of the conventional polybutylene terephthalate resin (Comparative Example 3), and the tensile elongation (fracture strain) is less reduced than that of other polyester resin compositions (Comparative Examples 1 and 2). Recognize.

Claims (4)

(A) with respect to 100 parts by weight of polybutylene terephthalate resin, (B) 5 to 100 parts by weight of polylactic acid resin having a melting point of 130 to 150 ° C. and a heat of crystal fusion of 0 to 10 J / g, (C) hydrolysis resistance improver A polyester resin composition comprising 0 to 5 parts by weight. (B) The polyester resin composition according to claim 1, wherein the polylactic acid resin has a heat of crystallization of 0 to 2 J / g and a heat of cold crystallization of 0 to 5 J / g. (C) The polyester resin composition according to claim 1 or 2, wherein the hydrolysis resistance improver is one or more selected from a carbodiimide compound and an epoxy compound. The molded article formed by injection-molding the polyester resin composition of any one of Claims 1-3.