JP6018049B2 - Inorganic filler reinforced polybutylene terephthalate resin composition and injection molded product formed by molding the resin composition - Google Patents

Description

  The present invention relates to an inorganic filler-reinforced polybutylene terephthalate resin composition and an injection molded product formed by molding the resin composition.

  Polybutylene terephthalate resin is excellent in mechanical properties, electrical properties, heat resistance, chemical resistance, and solvent resistance, so it is widely used as an engineering plastic for various applications such as automotive parts and electrical / electronic parts. ing.

  In recent years, resin materials for automobile parts and mobile electrical / electronic devices have been desired to be reduced in weight from the viewpoint of resource saving and low environmental load. When polybutylene terephthalate resin is used in these applications, weight reduction is also demanded along with improvement of physical properties such as impact strength and peelability.

  It is possible to reduce the weight of the resin material by melting and kneading a lower density polyolefin-based resin or the like into polybutylene terephthalate resin. May cause problems such as easy peeling of the surface layer.

  Conventionally, weight reduction of resin molded products and improvement in impact strength have been achieved while improving compatibility by melting and kneading polyolefin resins, modified polyolefin resins, compatibilizing agents, and the like with polyester resins (Patent Document 1). ~ 4).

  By the way, since polybutylene terephthalate resin has an ester group in a molecule | numerator, it has the fault that a physical property falls because molecular weight falls by hydrolysis. For this reason, it is also important to suppress this hydrolysis in the technology relating to the polybutylene terephthalate resin.

  According to the above Patent Documents 1 to 4, it is said that weight reduction of the product and improvement of the product performance can be realized. However, in the above Patent Documents 1 to 4, sufficient examination is made regarding improvement of hydrolysis resistance. Is not done.

  Polybutylene terephthalate resins are often used after being reinforced with an inorganic filler. However, in Patent Documents 1 to 4 above, sufficient studies on physical properties and the like are made regarding the resin material reinforced with an inorganic filler. Not.

JP-A-6-80867 Japanese Patent Laid-Open No. 6-295561 JP 2002-309069 A Japanese Patent Application Laid-Open No. 8-127777

  The present invention has been made in order to solve the above problems, and its purpose is to obtain a resin molded product having excellent hydrolysis resistance, light weight, and excellent physical properties such as impact strength. An object of the present invention is to provide an inorganic filler-reinforced polybutylene terephthalate resin composition, which is a raw material, and an injection-molded product obtained by injection-molding the resin composition.

  The present inventors have intensively studied to solve the above problems. As a result, an inorganic filler-reinforced polybutylene terephthalate resin composition capable of achieving the above object by combining a specific amount of a polybutylene terephthalate resin, a specific polyethylene resin, a specific reactive polymer, and a glass-based inorganic filler. Has been found, and the present invention has been completed. More specifically, the present invention provides the following.

(1) (A) Based on ISO 11443, with respect to 100 parts by mass of a polybutylene terephthalate resin having a melt viscosity of 30 Pa · s or more and 70 Pa · s or less measured at a temperature of 260 ° C. and a shear rate of 1216 s ⁻¹ . (B) In accordance with ISO11443, a polyethylene resin having a melt viscosity of 50 Pa · s or more and 220 Pa · s or less measured at a temperature of 260 ° C. and a shear rate of 1216 s ⁻¹ is 10 parts by mass or more and 100 parts by mass or less (C ) 2% by weight to 15% by weight of the monomer having a glycidyl group, 60% by weight to 98% by weight of the ethylene monomer, and 0% by weight to 30% by weight of the methacrylic acid alkyl ester monomer. 1 to 1 part by mass of a reactive copolymer composed of 0 to 30% by mass of an alkyl acrylate monomer. (D) glass-based inorganic filler is composed of 20 parts by mass or more and 50 parts by mass or less, and the amount of terminal carboxyl groups per kg of the (A) polybutylene terephthalate resin is α (meq / kg), (C) An inorganic filler-reinforced polybutylene terephthalate resin composition that satisfies the following inequality (1) when the epoxy equivalent of the reactive copolymer is γ (g / eq).
0.1 ≦ γ ⁻¹ × 10 ⁶ × w _γ / (α × w _α ) ≦ 5 (1)
[Where w _α is the content of (A) polybutylene terephthalate resin (100 parts by mass), w _γ is the content of (C) reactive copolymer (based on 100 parts by mass of (A) polybutylene terephthalate resin Content). ]

  (2) The inorganic filler-reinforced polybutylene terephthalate resin composition according to (1), wherein the epoxy equivalent of the (C) reactive copolymer is 1000 g / eq or more and 5000 g / eq or less.

  (3) The inorganic filler reinforcement according to any one of (1) and (2), wherein the (C) reactive copolymer is a copolymer composed of glycidyl methacrylate and an ethylene monomer. Polybutylene terephthalate resin composition.

(4) The inorganic filling according to any one of (1) to (3), wherein the polyethylene resin (B) is a linear low-density polyethylene having a density of 0.90 g / cm ³ or more and 0.93 g / cm ³ or less. Material-reinforced polybutylene terephthalate resin composition.

  (5) The inorganic filler-reinforced polybutylene terephthalate resin according to any one of (1) to (4), wherein the polyethylene resin (B) is a polyethylene resin obtained by polymerizing ethylene obtained by dehydrating bioethanol. Composition.

  (6) (F) The inorganic filler reinforcement according to any one of (1) to (5), wherein the glass-based inorganic filler is a glass fiber surface-treated with a silane coupling agent or a titanate coupling agent. Polybutylene terephthalate resin composition.

  (7) An injection molded product obtained by injection molding the inorganic filler-reinforced polybutylene terephthalate resin composition according to any one of (1) to (6).

  (8) The injection-molded article according to (7), wherein a mold temperature during the injection molding is 20 ° C. or higher and 100 ° C. or lower.

  According to the inorganic filler-reinforced polybutylene terephthalate resin composition of the present invention, it is possible to obtain a resin molded product having excellent hydrolysis resistance, light weight, and excellent physical properties such as impact strength.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment.

  The inorganic filler-reinforced polybutylene terephthalate resin composition of the present invention includes (A) a polybutylene terephthalate resin, (B) a polyethylene resin, (C) a reactive copolymer, and (D) a glass-based inorganic filler.

<(A) Polybutylene terephthalate resin>
(A) As polybutylene terephthalate resin, homopolyester (polybutylene terephthalate) and / or copolyester (butylene terephthalate copolymer, polybutylene terephthalate copolyester, or modified PBT resin) containing butylene terephthalate as a main component Is mentioned.

  As copolymerizable monomers in the copolyester (hereinafter sometimes simply referred to as copolymerizable monomers), dicarboxylic acid components other than terephthalic acid, diols other than 1,4-butanediol, oxycarboxylic acid components, and lactone components Etc. The copolymerizable monomers can be used alone or in combination of two or more.

Dicarboxylic acids (sometimes referred to as dicarboxylic acid components or dicarboxylic acids) include aliphatic dicarboxylic acids (for example, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecane dicarboxylic acid, dodecane dicarboxylic acid, hexamethylene decanedicarboxylic acid, C ₄ -C ₄₀ dicarboxylic acids such as dimer acid, preferably C ₄ -C ₁₄ dicarboxylic acids), alicyclic dicarboxylic acid component (e.g., hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, C ₈ -C ₁₂ dicarboxylic acids such as hymic acid), an aromatic dicarboxylic acid component other than terephthalic acid (e.g., phthalic acid, isophthalic acid, naphthalene dicarboxylic acid and 2,6-naphthalene dicarboxylic acid, 4 , 4′-Diphenyldicarboxylic acid, 4,4 '- di-phenoxy ether dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid, 4,4'-diphenyl ketone _C 8 _{-C 16} dicarboxylic acids such as dicarboxylic acids), or their reaction sex derivatives (e.g., lower alkyl esters (dimethyl phthalate, C ₁ -C ₄ alkyl esters of phthalic acid or isophthalic acid, such as dimethyl isophthalate, etc.), acid chloride, ester formable derivatives such as acid anhydrides) and the like Can be mentioned. Furthermore, you may use together polyvalent carboxylic acids, such as trimellitic acid and a pyromellitic acid, or its ester formation derivative (alcohol ester etc.) etc. as needed. When such a polyfunctional compound is used in combination, a branched polybutylene terephthalate resin can also be obtained.

Diols (sometimes referred to as diol components or diols) include, for example, aliphatic alkanediols excluding 1,4-butanediol [for example, alkanediols (eg, ethylene glycol, trimethylene glycol, propylene glycol, neopentyl glycol, Lower alkanediols such as hexanediol (1,6-hexanediol, etc.), octanediol (1,3-octanediol, 1,8-octanediol, etc.), decanediol, etc., preferably linear or branched C ₂ -C ₁₂ alkane diols, more preferably a straight chain or branched chain _C 2 _{-C 10} alkane diol); glycols having a (poly) oxyalkylene glycol (e.g., a plurality of _oxy-C 2 -C ₄ alkylene units, e.g. , Diethylene glycol, Propylene glycol, ditetramethylene glycol, triethylene glycol, tripropylene glycol, polytetramethylene glycol, etc.)], alicyclic diols (for example, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydrogenated bisphenol) a etc.), aromatic diols [e.g., hydroquinone, resorcinol, Jihidokishi _C 6 _{-C 14} arene naphthalene diol; biphenol (4,4'-hydrate carboxymethyl biphenyl); bisphenols; xylylene glycol], and These reactive derivatives (for example, ester-forming derivatives such as alkyl, alkoxy or halogen-substituted products) and the like can be mentioned. 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 bisphenols as examples of the diol include bis (4-hydroxyphenyl) methane (bisphenol F), 1,1-bis (4-hydroxyphenyl) ethane (bisphenol AD), 1,1-bis (4-hydroxy). Phenyl) propane, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane Bis (2,2-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) hexane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, etc. Hydroxyaryl) C1-6 alkane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1 1,1-bis (4-hydroxyphenyl) bis _{(hydroxyaryl)} such as cyclohexane C 4 _{-C 10} cycloalkane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide 4,4'-dihydroxydiphenyl ketone, and these alkylene oxide adducts. Examples of the alkylene oxide adduct include C _{2 to} C ₃ alkylene oxide adducts of bisphenols (eg, bisphenol A, bisphenol AD, bisphenol F), such as 2,2-bis [4- (2-hydroxyethoxy) phenyl]. Examples include propane, diethoxylated bisphenol A, 2,2-bis [4- (2-hydroxypropoxy) phenyl] propane, dipropoxylated bisphenol A, and the like. Alkylene oxide addition mole number of (ethylene oxide, _C 2 -C ₃ alkylene oxide such as propylene oxide) is 1 to 10 mol relative to each hydroxyl group, preferably about 1 to 5 mol.

Examples of the oxycarboxylic acid (or oxycarboxylic acid component or oxycarboxylic acid) include oxycarboxylic acids such as oxybenzoic acid, oxynaphthoic acid, hydroxyphenylacetic acid, glycolic acid, oxycaproic acid, and derivatives thereof. . Lactones include C ₃ -C ₁₂ lactones such as propiolactone, butyrolactone, valerolactone, caprolactone (eg, ε-caprolactone, etc.), and the like.

Of these copolymerizable monomers, diols [C ₂ -C ₆ alkylene glycol (linear or branched alkylene glycol such as ethylene glycol, trimethylene glycol, propylene glycol, hexane diol, etc.), repeat number, preferably Having about 2 to 4 oxyalkylene units, such as polyoxy C _{2 to} C ₄ alkylene glycol (diethylene glycol, etc.), bisphenols (bisphenols or alkylene oxide adducts thereof)], dicarboxylic acids [C ₆ -C ₁₂ aliphatic dicarboxylic acid Acid (adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, etc.), asymmetric aromatic dicarboxylic acid 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] are preferred.

  As the (A) polybutylene terephthalate resin, a homopolyester (polybutylene terephthalate) and / or a copolymer (polybutylene terephthalate copolyester) is preferable, and the (A) polybutylene terephthalate resin is a proportion of a copolymerizable monomer (modified). Homo or copolyester (especially homopolyester) of 0 mol% or more and 30 mol% or less, preferably 0 mol% or more and 25 mol% or less.

  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. It is in the range of about 0.1 mol% or more and 30 mol% or less (preferably 1 mol% or more and 25 mol% or less, more preferably 5 mol% or more and 25 mol% or less). Homopolyester / copolyester as mass ratio = 1/99 or more and 99/1 or less (mass ratio), preferably 5/95 or more and 95/5 or less (mass ratio), more preferably 10/90 or more and 90/10 or less ( It can be selected from a range of about (mass ratio).

  The (A) polybutylene terephthalate resin may be a commercially available product, and terephthalic acid or a reactive derivative thereof and 1,4-butanediol and, if necessary, a monomer copolymerizable with a conventional method, for example, You may use what was manufactured by copolymerization (polycondensation) by transesterification, 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.

(A) Polybutylene terephthalate resin has a melt viscosity (MV) measured at a temperature of 260 ° C. and a shear rate of 1216 s ⁻¹ in accordance with ISO 11443 of 30 Pa · s to 70 Pa · s. If the melt viscosity is less than 30 Pa · s, the tensile strength of the resin molded product obtained by molding the resin composition of the present invention may be reduced, and if it exceeds 70 Pa · s, the surface of the resin molded product is peeled off. In some cases, neither is preferable.

  A polybutylene terephthalate resin having a melt viscosity within the above range can be produced by appropriately adjusting the production conditions in a conventionally known resin production method. Alternatively, polybutylene terephthalate resins having different melt viscosities may be blended to adjust the melt viscosity to the above range.

  The amount of terminal carboxyl groups of the (A) polybutylene terephthalate resin used in the present invention is preferably 1 meq / kg or more and 30 meq / kg or less. When the (A) polybutylene terephthalate resin having a terminal carboxyl group content in such a range is used, the resin composition of the present invention is less susceptible to strength reduction due to hydrolysis in a moist heat environment.

<(B) Polyethylene resin>
Examples of the polyethylene resin (B) used in the present invention include high-density polyethylene, low-density polyethylene, and linear low-density polyethylene, and linear low-density polyethylene is particularly preferable from the viewpoint of impact strength. In addition, the method for producing the (B) polyethylene resin is not particularly limited, and for example, conventionally known various catalysts such as a Ziegler catalyst and a metallocene catalyst in linear low density polyethylene can be used. Further, (B) the amount of the catalyst contained in the polyethylene resin and the amount of unreacted unsaturated bonds are not limited. Further, it may be one that has once been made to have a low molecular weight by thermally decomposing the polyethylene.

  (B) As the polyethylene resin, a polyethylene resin polymerized using a bio-derived raw material may be used, and in particular, a polyethylene resin polymerized using ethylene obtained by dehydrating bioethanol may be used. By using such a polyethylene resin, it is possible to reduce the amount of petroleum resources that are expected to be depleted in the future. Further, it is possible to reduce the carbon dioxide emission amount based on the concept of carbon neutral considering the carbon dioxide emission amount of the material throughout the life cycle, assuming that the plant as a raw material absorbs carbon dioxide by photosynthesis.

(B) the density of the polyethylene resin is preferably from 0.90 g / cm ³ or more 0.97 g / cm ³ or less, particularly preferably 0.90 g / cm ³ or more 0.93 g / cm ³ or less. When the density exceeds 0.97 g / cm ³ , the effect of improving the impact strength of the resin molded product obtained by molding the resin composition of the present invention may not be seen, and the density is smaller than 0.90 g / cm ^3. Since the rigidity of the resin molded product may be lowered, both are not preferable.

(B) The polyethylene resin has a melt viscosity (MV) measured at a temperature of 260 ° C. and a shear rate of 1216 s ⁻¹ in accordance with ISO 11443 of 50 Pa · s to 220 Pa · s. If it is less than 50 Pa · s, the rigidity of the resin molded product obtained by molding the resin composition of the present invention may decrease, and if it exceeds 220 Pa · s, the moldability of the resin composition of the present invention may deteriorate. Yes, neither is preferred.

  The content of (B) polyethylene resin is 10 parts by mass or more and 100 parts by mass or less per 100 parts by mass of (A) polybutylene terephthalate resin. If the amount is less than 10 parts by mass, the effect of improving the impact strength of the resin molded product obtained by molding the resin composition of the present invention is not observed. If the amount exceeds 100 parts by mass, the surface of the resin molded product may be peeled off. This is not preferable because it may cause a decrease in strength and heat resistance of the resin molded product.

<(C) Reactive copolymer>
In the present invention, (C) a reactive copolymer is used as a compatibilizer between a polyester resin and a polyethylene resin. The (C) reactive copolymer used in the present invention is a (C) reactive copolymer composed of a monomer having a glycidyl group and an ethylene monomer. In addition to this, a (C) reactive copolymer composed of three or more types of monomers including an alkyl methacrylate ester monomer and an alkyl alkyl ester monomer may be used.

(C) When the epoxy equivalent of the reactive copolymer is γ (g / eq) and (A) the amount of terminal carboxyl groups per kg of the polybutylene terephthalate resin is α (meq / kg), The ratio to the equivalent of the terminal carboxyl group (expressed as γ ⁻¹ × 10 ⁶ × w _γ / (α × w _α ), hereinafter may be referred to as “epoxy / resin equivalent ratio”) is 0.1 or more and 5 It is as follows. If the epoxy / resin equivalent ratio is less than 0.1, the resin molded product obtained by molding the resin composition of the present invention is not excellent in hydrolysis resistance, and if it exceeds 5, the fluidity of the resin composition is lowered. In some cases, the moldability may be deteriorated due to the above. Here, w _α is the content of (A) polybutylene terephthalate resin (100 parts by mass), and w _γ is the content of (C) reactive copolymer ((A) with respect to 100 parts by mass of polybutylene terephthalate resin (C ) Reactive copolymer content).

  (C) The reactive copolymer comprises a monomer having a glycidyl group in an amount of 2% by mass to 15% by mass, an ethylene monomer of 60% by mass to 98% by mass, and a methacrylic acid alkyl ester monomer. Is composed of 0 mass% to 30 mass%, and the acrylic acid alkyl ester monomer is composed of 0 mass% to 30 mass%. A preferable (C) reactive copolymer has an epoxy equivalent of 1000 g / eq or more and 5000 g / eq or less. Further, (C) the reactive copolymer is more preferably a copolymer of glycidyl methacrylate and an ethylene monomer.

  (C) Content of a reactive copolymer is 1 to 15 mass parts per 100 mass parts of (A) polybutylene terephthalate resin. When the amount is less than 1 part by mass, the improvement in hydrolysis resistance of the resin molded product obtained by molding the resin composition of the present invention is hardly observed, or peeling may occur on the surface of the resin molded product. If it exceeds 15 parts by mass, the moldability may be deteriorated due to a decrease in fluidity when the resin composition of the present invention is melted.

<(D) Glass-based inorganic filler>
(D) Glass-based inorganic filler used in the present invention is filled with fiber (glass fiber), granular (glass bead), powder (milled glass fiber), and plate (glass flake) depending on the purpose. A material, a hollow shape (glass balloon) or a mixture thereof is used, and among them, a fibrous glass fiber is particularly preferable.

  Moreover, it is preferable to use the inorganic filler processed by surface treatment agents, such as a silane type or a titanate type coupling agent, as a glass-type inorganic filler of these (D) components.

  Examples of the silane coupling agent include vinyl alkoxy silane, epoxy alkoxy silane, amino alkoxy silane, mercapto alkoxy silane, and allyl alkoxy silane.

  Examples of the vinylalkoxysilane include vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (β-methoxyethoxy) silane, and the like.

  Examples of the epoxyalkoxysilane include γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and the like.

  Examples of the aminoalkoxysilane include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, and N-phenyl-γ-aminopropyltrimethoxy. Silane etc. are mentioned.

  Examples of mercaptoalkoxysilanes include γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.

  Examples of allylalkoxysilane include γ-diallylaminopropyltrimethoxysilane, γ-allylaminopropyltrimethoxysilane, γ-allylthiopropyltrimethoxysilane, and the like.

  Examples of titanate-based surface treatment agents include titanium-i-propoxyoctylene glycolate, tetra-n-butoxy titanium, tetrakis (2-ethylhexoxy) titanium, and the like. Moreover, in glass fiber, what uses a polymer binder, an adhesion promoter, another adjuvant, etc. as a sizing agent is used suitably. As the polymer binder, generally known materials such as organic materials such as water-dispersible / water-soluble polyvinyl acetate, polyester, epoxide, polyurethane, polyacrylate or polyolefin resin, and mixtures thereof are preferably used.

  In this invention, the usage-amount of (D) glass-type inorganic filler is 20 to 50 mass parts with respect to 100 mass parts of (A) polybutylene terephthalate resin. When the amount is more than 50 parts by mass, the fluidity at the time of melting of the resin composition of the present invention may be impaired, which is not preferable. When the amount is less than 20 parts by weight, it may be difficult to use in a field where high rigidity is required for a resin molded product formed by molding the resin composition of the present invention.

<Other ingredients>
The inorganic filler-reinforced polybutylene terephthalate resin composition of the present invention includes other resins (thermoplastic resins, etc.), various additives and fillers, as long as they do not impair the effects of the present invention. For example, an antioxidant may be included.

<Preparation method and use of resin composition>
The specific embodiment of the method for preparing the resin composition of the present invention is not particularly limited. In general, the resin composition can be prepared by equipment and methods known as methods for preparing a synthetic resin composition or a molded product thereof. . That is, necessary components can be mixed and kneaded using a single or twin screw extruder or other melt kneader to prepare a pellet for molding. A plurality of extruders or other melt kneaders may be used. The kneading temperature (cylinder temperature) of the resin composition is preferably 225 ° C. or higher and 275 ° C. or lower, more preferably 235 ° C. or higher and 265 ° C. or lower. When the kneading temperature is higher than 275 ° C, the decomposition of the resin tends to proceed during the kneading, and when it is lower than 225 ° C, the resulting polybutylene terephthalate resin composition may not be excellent in hydrolysis resistance, which is not preferable.

  As shown in the examples, the resin molded product obtained by molding the resin composition of the present invention has a tensile strength retention of 70% or more when exposed to moisture and heat conditions of 121 ° C. and 100% RH for 72 hours. Excellent hydrolyzability. In addition, the weight is lighter than when an inorganic filler is added to the polybutylene terephthalate resin alone. The specific gravity is preferably less than 1.4.

  Using the resin composition of the present invention as a raw material, various conventionally known molding methods (for example, injection molding, extrusion molding, compression molding, blow molding, vacuum molding, foam molding, rotational molding, gas injection molding, etc.) A molded product can be formed. Among them, it is particularly suitable for injection molding and can be molded under a mold temperature of 20 ° C. or more and 100 ° C. or less.

  These molded products include automotive parts (interior parts, electrical system parts, in-vehicle electrical / electronic parts, mechanical parts, parts in contact with metal, etc.), electrical / electronic parts (audio equipment, OA equipment chassis, levers, etc.) ), Miscellaneous goods, stationery, etc.

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

Details of the components used and measurement methods for evaluating physical properties are as follows.
(A) Polybutylene terephthalate resin (A-1) Polybutylene terephthalate (manufactured by Wintech Polymer Co., Ltd., melt viscosity 62 Pa · s, terminal carboxyl group amount 24 meq / kg)
(A-2) Polybutylene terephthalate (Wintech Polymer Co., Ltd., melt viscosity 173 Pa · s, terminal carboxyl group content 15 meq / kg)
(B) Polyethylene resin (B-1) Linear low-density polyethylene: LL-318 (manufactured by Braskem, density 0.918 g / cm ³ , melt viscosity 205 Pa · s)
(B-2) High density polyethylene: HA7260 (manufactured by Braskem, density 0.955 g / cm ³ , melt viscosity 67 Pa · s)
(B-3) Linear low-density biopolyethylene: SLL-318 (manufactured by Braskem, density 0.918 g / cm ³ , melt viscosity 210 Pa · s)
(B-4) High-density biopolyethylene: SHA7260 (manufactured by Braskem, density 0.955 g / cm ³ , melt viscosity 73 Pa · s)
(B-5) High-density biopolyethylene: SHC7260 (manufactured by Braskem, density 0.958 g / cm ³ , melt viscosity 140 Pa · s)
(B-6) High density biopolyethylene: SGE7252 (manufactured by Braskem, density 0.950 g / cm ³ , melt viscosity 177 Pa · s)
(C) Reactive copolymer having glycidyl group (C-1) Glycidyl methacrylate / ethylene copolymer: Bondfast E (manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent of about 1180 g / eq, glycidyl methacrylate 12% by weight) )
(C-2) Glycidyl methacrylate / methyl acrylate / ethylene Copolymer: Bondfast 7M (manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent of about 2370 g / eq, glycidyl methacrylate 6 mass%, methyl acrylate 27 mass%)
(D) Glass-based inorganic filler Glass fiber (E-glass): ECS03T-187 (manufactured by Nippon Electric Glass Co., Ltd.)
(E) Antioxidant: Tetrakis [methylene 3 (3,5-di-tert-butyl 4-hydroxyphenyl) propionate] methane (manufactured by BASF)

<Measurement of melt viscosity of component (A) and component (B)>
Measured according to ISO11443. After drying (A) polybutylene terephthalate resin at 140 ° C. for 3 hours and (B) polyethylene resin at 105 ° C. for 4 hours using an air blow dryer, respectively, Capillograph 1B (capillary rheometer manufactured by Toyo Seiki Co., Ltd.) The melt viscosity was measured for each resin under the conditions of a temperature of 260 ° C., a shear rate of 1216 s ⁻¹ , and a capillary L / D = 20/1. The measurement results are shown in parentheses in detail for the components (A-1) to (A-3) and (B-1) to (B-6).

<Examples 1-9, Comparative Examples 1-6>
Ingredients other than the inorganic filler shown in Tables 1 and 2 were each dry blended and supplied from a hopper port to a twin-screw extruder having a 30 mmφ screw (Tex-30α manufactured by Nippon Steel Works), and An inorganic filler was supplied from the side port in the middle of the kneading part and melt-kneaded under the following melt-kneading conditions to obtain a pellet-shaped resin composition. Subsequently, molding and evaluation were performed using the obtained resin composition. In addition, the unit of the number showing the usage-amount of each component in Table 1 is a mass part.

<Melting and kneading conditions>
Extruder screw: L / D = 38.5
Discharge rate: 15kg / h
Screw rotation speed: 129rpm
Barrel temperature: C2 = 220 ° C., C3 to C11, die head = 250 ° C.
Here, C2 to C11 indicate the temperature of the heater in order from the supply port side.

<Molding conditions of test piece for evaluating mechanical properties>
The obtained pellets were dried at 140 ° C. for 3 hours, and then a test piece was injection molded under the following conditions.
Molding machine: ROBOSHOT S2000i100B manufactured by FANUC
Cylinder temperature: 250 ° C
Mold temperature: 80 ° C (water temperature control)
Injection speed: 26mm / s
Holding pressure: 60MPa x 20s

<Tensile strength, tensile elongation (fracture strain)>
Using test pieces for evaluating mechanical properties, tensile strength and tensile elongation were evaluated according to the evaluation standards defined in ISO527-1,2.

<Impact strength>
Charpy impact strength was evaluated according to an evaluation standard defined in ISO-179 (test piece thickness: 4 mm) using a test piece for evaluating mechanical properties.

<Evaluation of hydrolysis resistance>
A tensile test piece (ISO527-1, 2 compliant) was produced in the same manner as the test piece for evaluating mechanical properties, and this test piece was placed in a thermo-hygrostat at 121 ° C. and 100% RH for 72 hours. Exposure treatment. Thereafter, a tensile test was performed, the tensile strength was measured, and the retention rate with respect to the value of the untreated tensile strength was obtained.

<Epoxy / resin equivalent ratio>
(A) The amount of terminal carboxyl groups per kg of the polybutylene terephthalate resin is α (meq / kg), and the epoxy equivalent of the (C) reactive copolymer is γ (g / eq). γ ⁻¹ × 10 ⁶ × w _γ / (α × w _α ) was calculated. Here, w _α is the content of (A) polybutylene terephthalate resin (100 parts by mass), w _γ is the content of (C) reactive copolymer (the content of polybutylene terephthalate resin is 100 parts by mass) Represents the content of the reactive copolymer). The amount of terminal carboxyl groups of the polybutylene terephthalate resin was determined by titration by acid-alkali neutralization method (titration measurement) using methyl red as an indicator.

<Peelability>
100 squares of 1 mm square were provided with a cutter knife in the 1 cm square of the central portion of the chuck portion of the tensile test piece (ISO527-1, 2 compliant), and a cellophane tape was once applied thereto, and then peeled off. Of 100 squares, the number of squares whose surface was peeled off by this operation was visually measured. Evaluation was performed according to the following criteria.
(Evaluation criteria)
No peeling: ○
1 to 5 sheets peeled: △
5 or more peeling: ×

<Specific gravity>
The weight in air and the weight in water of the test piece for evaluating mechanical properties produced by the above method at 23 ° C. were measured to determine the specific gravity.

<Measurement of melt viscosity of resin composition>
The melt viscosity of the resin composition was measured according to ISO11443. Specifically, after the resin compositions of Examples and Comparative Examples were previously dried at 140 ° C. for 3 hours using a blow dryer, the temperature was 260 using a Capillograph 1B (capillary rheometer) manufactured by Toyo Seiki Co., Ltd. The melt viscosity was measured under the conditions of ° C., shear rate 1216 s ⁻¹ , and capillary L / D = 20/1. The measurement results are shown in Tables 1 and 2.

  From the examples and comparative examples, it can be confirmed that there is a correlation between the epoxy / resin equivalent ratio and the hydrolysis resistance. Specifically, the lower the epoxy / resin equivalent ratio, the less the hydrolysis resistance, and the higher the epoxy / resin equivalent ratio, the better the hydrolysis resistance.

  From the comparison between Example 1 and Example 3 and the comparison between Example 8 and Examples 5-7, if linear low density polyethylene is used as the polyethylene resin, the impact strength of the resin molded product is further increased. It was confirmed.

  From Examples 5 to 9, it was confirmed that even when plant-derived polyethylene was used, the resin molded product was excellent in hydrolysis resistance, lightweight, and excellent in physical properties such as impact strength.

  From the comparison between Example and Comparative Example 7, it was confirmed that when a polybutylene terephthalate resin having a melt viscosity in an appropriate range was used as the polybutylene terephthalate resin, the resulting resin composition was excellent in fluidity.

  From the comparison between Example and Comparative Example 8, it was confirmed that when the epoxy / resin equivalent ratio was in an appropriate range, the resulting resin composition was excellent in fluidity.

Claims (8)

(A) Based on ISO 11443, with respect to 100 parts by mass of a polybutylene terephthalate resin having a melt viscosity of 30 Pa · s or more and 70 Pa · s or less measured at a temperature of 260 ° C. and a shear rate of 1216 s ⁻¹ .
(B) 46.6 parts by mass or more and 100 parts by mass or less of a polyethylene resin having a melt viscosity of 50 Pa · s or more and 220 Pa · s or less measured at a temperature of 260 ° C. and a shear rate of 1216 s ⁻¹ in accordance with ISO11443.
(C) 2% by mass to 15% by mass of a monomer having a glycidyl group, 60% by mass to 98% by mass of an ethylene monomer, and 0% by mass to 30% by mass of a methacrylic acid alkyl ester monomer. % Or less, 1 to 15 parts by mass of a reactive copolymer composed of 0 to 30% by mass of an alkyl acrylate monomer.
(D) a glass inorganic filler 20 parts by mass or more 50 parts by weight, it consists,
When the terminal carboxyl group amount per kg of the (A) polybutylene terephthalate resin is α (meq / kg) and the epoxy equivalent of the (C) reactive copolymer is γ (g / eq), the following inequality (1 An inorganic filler reinforced polybutylene terephthalate resin composition satisfying
0.1 ≦ γ ⁻¹ × 10 ⁶ × w _γ / (α × w _α ) ≦ 5 (1)
[Where w _α is the content of (A) polybutylene terephthalate resin (100 parts by mass), w _γ is the content of (C) reactive copolymer (based on 100 parts by mass of (A) polybutylene terephthalate resin Content). ]   The inorganic filler-reinforced polybutylene terephthalate resin composition according to claim 1, wherein the epoxy equivalent of the (C) reactive copolymer is 1000 g / eq or more and 5000 g / eq or less.   The inorganic filler-reinforced polybutylene terephthalate resin composition according to claim 1 or 2, wherein the (C) reactive copolymer is a copolymer composed of glycidyl methacrylate and an ethylene monomer. object. The inorganic filler-reinforced polybutylene terephthalate according to any one of claims 1 to 3, wherein the polyethylene resin (B) is a linear low-density polyethylene having a density of 0.90 g / cm ³ or more and 0.93 g / cm ³ or less. Resin composition. A method for producing an inorganic filler-reinforced polybutylene terephthalate resin composition according to any one of claims 1 to 4,
At least kneading the (A) polybutylene terephthalate resin, the (B) polyethylene resin, the (C) reactive copolymer, and the (D) glass-based inorganic filler,
Wherein the (B) polyethylene resins, Ru polyethylene resin der obtained by polymerizing ethylene obtained by dehydration of bioethanol
Method for producing a non-machine filler reinforced polybutylene terephthalate resin composition. (D) method for producing a glass inorganic filler, a silane coupling agent or a titanate coupling according to claim 5 Symbol mounting of the inorganic filler is glass fiber surface-treated with agents strengthening polybutylene terephthalate resin composition. Method for manufacturing an injection-molded article injection molding according inorganic filler reinforcement of items 1 4 any one of claims polybutylene terephthalate resin composition. The method for producing an injection-molded article according to claim 7, wherein a mold temperature at the time of the injection molding is 20 ° C or higher and 100 ° C or lower.