JPWO2020116629A1 - Polybutylene terephthalate resin composition and double molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mold a polybutylene terephthalate resin composition capable of molding a molded product having excellent bonding strength in a double molded product with a polycarbonate resin molded product in addition to alkali resistance, and polycarbonate resin molding using the resin composition. Provided is a double-molded product that is firmly bonded to the product. SOLUTION: (A) 100 parts by mass of polybutylene terephthalate resin, (B) 35 to 65 parts by mass of a polycarbonate resin having a melt viscosity of 0.40 kPa · s or less at 300 ° C., (C) 10 to 30 parts by mass of an olefin elastomer. Includes 1 to 3 parts by mass of (D) a silicone-based compound having a kinematic viscosity at 25 ° C. of 1000 to 10000 cSt, (E) 30 to 80 parts by mass of a filler, and (F) 1 to 5 parts by mass of an epoxy-based compound. , Polybutylene terephthalate resin composition for double molding with a molded product of a polycarbonate resin composition. [Selection diagram] None

Description

The present invention relates to polybutylene terephthalate resin compositions and double molded articles.

Polybutylene terephthalate resin is a crystalline thermoplastic resin with excellent mechanical strength, electrical properties, and various other properties, so it is used as an engineering plastic in a wide range of applications including automobiles, electrical and electronic equipment, etc. Has been done. However, polybutylene terephthalate resin tends to have low long-term durability against alkaline solutions, and its usage environment and applications have been limited. For example, some parts may be used in places where they come into contact with toilet cleaning agents, bathtub cleaning agents, bleaching agents, snow melting agents, and the like. Since these chemicals contain sodium hydroxide, sodium hypochlorite, sodium percarbonate, calcium chloride and the like as their components, the resin molded product is exposed to an alkaline atmosphere. When a resin molded product is exposed to the above-mentioned alkaline atmosphere for a long time in a state where it is excessively distorted by screw tightening, metal press-fitting, caulking, etc., it is affected by both the strain and the alkaline component, so-called environment. This has been a problem because stress cracking occurs and cracks occur in the molded product.
In addition, polybutylene terephthalate resin is often used as an insert molded product into which a metal or an inorganic solid (hereinafter, also referred to as metal) is inserted. In such an insert molded product, there is a so-called weld portion, which is an interface where the resin wraps around the metal or the like and joins during injection molding. The above-mentioned environmental stress cracking generally often occurs in the weld portion of the molded product. Furthermore, since the shrinkage rate and linear expansion coefficient are different between resin and metal, cracks (heat shock failure) due to strain generated in the surrounding resin such as metal in insert molded products used in an environment where temperature rise and fall are repeated. ) Is likely to occur. Therefore, if the insert molded product comes into contact with the alkaline solution as described above and is left in an environment where the temperature rises and falls repeatedly for a long period of time, cracks occur around the weld and the metal, which is a problem. It was.

Measures to add a silicone compound and / or a fluorine compound or a polycarbonate resin are known in order to suppress the occurrence of cracks in the insert molded product that comes into contact with the alkaline solution as described above. Further, in order to minimize the influence of strain due to temperature change, a measure of adding an impact resistance imparting agent such as an elastomer is also known.

For example, Patent Document 1 describes (A) a thermoplastic polyester resin, (B) an impact resistance imparting agent, (C) a silicone-based compound and / or a fluorine-based compound, (D) an inorganic filler, and (E) many. A thermoplastic polyester resin composition in which a predetermined amount of each functional compound is blended is described, and it is disclosed that a molded product having excellent alkali resistance can be obtained by using this thermoplastic polyester resin composition.

Further, Patent Document 2 describes alkali resistance and heat shock resistance, each of which contains a predetermined amount of a polybutylene terephthalate resin, a silicone compound having a kinematic viscosity of 1000 to 10000 cSt at 25 ° C., and an olefin elastomer. A polybutylene terephthalate resin composition having excellent properties is disclosed.

Further, Patent Document 3 describes (A) a polybutylene terephthalate resin having an isophthalic acid component content of 3 to 30 mol% with respect to the total dicarboxylic acid component, (B) a polycarbonate resin, (C) elastoma, and (D). ) A polyester resin composition having excellent alkali resistance and mechanical strength, which comprises a predetermined amount of each of a fibrous reinforcing material and (E) a silicone compound, is disclosed.

International Publication No. 2000/078867 International Publication No. 2018/047662 JP-A-2002-356611

However, the molded product made of these polybutylene terephthalate resin compositions is not only as an insert molded product with a metal or the like, but also as a molded product made of another resin composition, for example, a molded product made of a polycarbonate resin composition. It may be used in combination with a member (optical component, etc.). In such a case, secondary processing such as adhesion or welding is often used for joining the molded products, but from the viewpoint of process simplification, it is preferable that the molded products can be integrated by double molding. Therefore, the polybutylene terephthalate resin composition, which is also excellent in bondability during double molding with a molded product made of a polycarbonate resin composition (hereinafter, also referred to as "polycarbonate resin molded product" or "polycarbonate resin composition molded product"). Things are sought after.

The present invention has been made to solve the above problems, and polybutylene capable of molding a molded product having excellent bonding strength in a double-molded product with a polycarbonate resin molded product in addition to alkali resistance. An object of the present invention is to provide a terephthalate resin composition and a double-molded product firmly bonded to a polycarbonate resin molded product using the resin composition.

The present invention relates to the following matters.
[1] One aspect of the present invention is (A) 100 parts by mass of polybutylene terephthalate resin, (B) 35 to 65 parts by mass of polycarbonate resin, (C) 10 to 30 parts by mass of olefin-based elastoma, and (D) silicone-based compound. It contains 1 to 3 parts by mass, (E) 30 to 80 parts by mass of the filler, and 1 to 5 parts by mass of the (F) epoxy compound, and the melt viscosity of the (B) polycarbonate resin at 300 ° C. and 1000 sec ^-1 is 0. It relates to a polybutylene terephthalate resin composition for double molding with a molded product of a polycarbonate resin composition, which is 40 kPa · s or less and has a kinematic viscosity of the silicone compound (D) at 25 ° C. of 1000 to 10000 cSt.
[2] A further aspect of the present invention relates to the polybutylene terephthalate resin composition according to [1], wherein the silicone-based compound (D) contains dimethylpolysiloxane.
[3] A further aspect of the present invention relates to the polybutylene terephthalate resin composition according to [1] or [2], wherein the (C) olefin-based elastomer contains an ethylene ethyl acrylate copolymer.
[4] A further aspect of the present invention relates to the polybutylene terephthalate resin composition according to any one of [1] to [3], wherein the (E) filler contains a fibrous filler.
[5] A further aspect of the present invention relates to the polybutylene terephthalate resin composition according to any one of [1] to [4], wherein the polycarbonate resin (B) has a viscosity average molecular weight of 18,000 or less.
[6] Another aspect of the present invention is that the polybutylene terephthalate resin composition according to any one of [1] to [5] is double-molded with a molded product made of a polycarbonate resin composition. Regarding double molded products. That is, another aspect of the present invention has a portion containing the polybutylene terephthalate resin composition according to any one of [1] to [5] and a portion containing a polycarbonate resin composition, and is composed of polybutylene. The present invention relates to a double-molded article in which a portion containing a terephthalate resin composition and a portion containing a polycarbonate resin composition are in contact with each other at least in part.
[7] Another aspect of the present invention relates to the double-molded article according to [6], which is an insert-molded article further including an insert member made of a metal and / or an inorganic solid.
[8] Another aspect of the present invention relates to the double-molded article according to [6] or [7], which is used as a part in contact with an alkaline solution.

According to the embodiment of the present invention, a polybutylene terephthalate resin composition capable of molding a molded product having excellent bonding strength in a double-molded product with a polycarbonate resin molded product in addition to alkali resistance, and the resin composition. It is possible to provide a double-molded product that is firmly bonded to a polycarbonate resin molded product using a product.

<Polybutylene terephthalate resin composition>
In the present embodiment, the polybutylene terephthalate resin composition (hereinafter, may be simply referred to as “resin composition”) includes a polybutylene terephthalate resin, a specific amount of polycarbonate resin, and a specific amount of olefin-based epoxy. It is characterized by containing a specific amount of a filler, a specific amount of a silicone-based compound having a kinematic viscosity at 25 ° C. of 1000 to 10000 cSt, and a specific amount of an epoxy-based compound. By using such a resin composition, it is possible to mold a molded product having excellent bonding strength in a double-molded product with a polycarbonate resin molded product in addition to alkali resistance.
In the present specification, the "double-molded product" means a molded product in which another resin layer is injection-molded so as to be in contact with at least a part of the pre-molded resin layer. It is different from a molded product in which molded resin layers are joined or welded together.

Hereinafter, each component used in the resin composition of the present embodiment will be described.

(A) Polybutylene terephthalate resin (A) Polybutylene terephthalate resin (PBT resin) contains at least a dicarboxylic acid component containing terephthalic acid or an ester-forming derivative thereof (C _1-6 alkyl ester, acid halide, etc.). It is a polybutylene terephthalate resin obtained by polycondensation with a glycol component containing at least an alkylene glycol (1,4-butanediol) having 4 carbon atoms or an ester-forming derivative thereof (acetylated product or the like). The polybutylene terephthalate resin (A) is not limited to the homopolybutylene terephthalate resin, and may be a copolymer containing 60 mol% or more (particularly 75 mol% or more and 95 mol% or less) of butylene terephthalate units.

The amount of terminal carboxyl groups of the polybutylene terephthalate resin (A) is not particularly limited as long as the object of the present invention is not impaired. The amount of terminal carboxyl groups of the polybutylene terephthalate resin (A) used in the present embodiment is preferably 5 meq / kg or more and 30 meq / kg or less, and more preferably 10 meq / kg or more and 25 meq / kg or less. By using a polybutylene terephthalate resin having a terminal carbotylsyl group amount in such a range, the obtained polybutylene terephthalate resin composition is less likely to be subjected to a decrease in strength due to hydrolysis in a moist heat environment.

The intrinsic viscosity (IV) of the polybutylene terephthalate resin (A) is preferably 0.60 dL / g or more and 1.20 dL / g or less, more preferably 0.65 dL / g or more and 1.00 dL / g or less. More preferably, it is 0.70 dL / g or more and 0.95 dL / g or less, and particularly preferably 0.75 dL / g or more and 0.90 dL / g or less. When a polybutylene terephthalate resin having an intrinsic viscosity in the range of 0.60 dL / g or more and 1.20 dL / g or less is used, the obtained polybutylene terephthalate resin composition is particularly excellent in moldability and mechanical properties. .. It is also possible to adjust the intrinsic viscosity by blending polybutylene terephthalate resins having different intrinsic viscosities. For example, a polybutylene terephthalate resin having an intrinsic viscosity of 0.85 dL / g can be prepared by blending a polybutylene terephthalate resin having an intrinsic viscosity of 1.0 dL / g and a polybutylene terephthalate resin having an intrinsic viscosity of 0.7 dL / g. Can be done. The intrinsic viscosity (IV) of the polybutylene terephthalate resin (A) can be measured, for example, in o-chlorophenol under the condition of a temperature of 35 ° C.

In the (A) polybutylene terephthalate resin, examples of the dicarboxylic acid component (comonomer component) other than terephthalic acid and its ester-forming derivative include isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4'-. C _8-14 aromatic dicarboxylic acid such as dicarboxydiphenyl ether; C _4-16 alcandicarboxylic acid such as succinic acid, adipic acid, azelaic acid, sebacic acid; C _5-10 cycloalcandicarboxylic acid such as cyclohexanedicarboxylic acid Acids; Examples thereof include ester-forming derivatives of these dicarboxylic acid components (C _1-6 alkyl ester derivatives, acid halides, etc.). These dicarboxylic acid components can be used alone or in combination of two or more.

Among these dicarboxylic acid components, C _8-12 aromatic dicarboxylic acids such as isophthalic acid and C _6-12 alkane dicarboxylic acids such as adipic acid, azelaic acid and sebacic acid are more preferable.

In the (A) polybutylene terephthalate resin, examples of the glycol component (comonomer component) other than 1,4-butanediol include ethylene glycol, propylene glycol, trimethylene glycol, 1,3-butylene glycol, hexamethylene glycol, and neo. C _2-10 alkylene glycols such as pentyl glycols and 1,3-octanediols; polyoxyalkylene glycols such as diethylene glycols, triethylene glycols and dipropylene glycols; alicyclic diols such as cyclohexanedimethanol and hydride bisphenol A; Aromatic diols such as bisphenol A and 4,4'-dihydroxybiphenyl; C _2-4 alkylene oxide adducts of bisphenol A such as ethylene oxide 2 mol adducts of bisphenol A and propylene oxide 3 mol adducts of bisphenol A. ; Or, ester-forming derivatives of these glycols (acetylated products, etc.) can be mentioned. These glycol components can be used alone or in combination of two or more.

Among these glycol components, C _2-6 alkylene glycols such as ethylene glycol and trimethylene glycol, polyoxyalkylene glycols such as diethylene glycol, and alicyclic diols such as cyclohexanedimethanol are more preferable.
Examples of the comonomer component that can be used in addition to the dicarboxylic acid component and the glycol component include 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 4-carboxy-4'-hydroxybiphenyl and the like. Aromatic hydroxycarboxylic acids; aliphatic hydroxycarboxylic acids such as glycolic acid and hydroxycaproic acid; C _3-12 lactones such as propiolactone, butyrolactone, valerolactone, caprolactone (ε-caprolactone, etc.); esters of these comonomer components Examples thereof include formable derivatives (C _1-6 alkyl ester derivatives, acid halides, acetylates, etc.).

Any of the polybutylene terephthalate copolymers copolymerized with the comonomer components described above can be suitably used as the (A) polybutylene terephthalate resin. Further, as the (A) polybutylene terephthalate resin, a homopolybutylene terephthalate polymer and a polybutylene terephthalate copolymer may be used in combination. However, from the viewpoint of alkali resistance, it is preferable to use a homopolybutylene terephthalate polymer that does not contain a copolymerization component.

(B) Polycarbonate Resin The polybutylene terephthalate resin composition of the present embodiment is excellent in a double-molded product with a polycarbonate molded product without impairing alkali resistance by containing the (B) polycarbonate resin having a specific melt viscosity. Has good adhesion.

Examples of the polycarbonate resin (B) include a polymer obtained by reacting a dihydroxy compound with a carbonic acid ester such as phosgene or diphenyl carbonate.

Examples of the dihydroxy compound include alicyclic compounds (for example, alicyclic diols) and bisphenol compounds, and bisphenol compounds are preferable.

Examples of the bisphenol compound include bis (4-hydroxyphenyl) methane, bis (4-hydroxy-3-methylphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, and 1,1-bis (4-hydroxy-). 3-Methylphenyl) ethane, 1,1-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 2,2-bis (4-hydroxy-3-methyl) Phenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3-ethylphenyl) propane, 2,2-bis (4-hydroxy-) 3-t-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-Methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) hexane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2, 2-Bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) dibenzylmethane, 1,1-bis (4-hydroxy) Phenyl) -1-phenylpropane, 2,2,2', 2'-tetrahydro 3,3,3', 3'-tetramethyl-1,1'-spirobi- [1H-inden] -6,6'- Bis (hydroxyaryl) C _1-10 alkanes such as diols, preferably bis (hydroxyaryl) C _1-6 alkanes; 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxy) Bis (hydroxyaryl) C _4-10 cycloalkanes such as phenyl) cyclohexane; dihydroxyaryl ethers such as 4,4'-dihydroxydiphenyl ethers, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ethers; 4,4'. Dihydroxyarylsulfones such as −dihydroxydiphenylsulfone, 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone; 4,4′-dihydroxydiphenylsulfide, 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfide Etc. of dihydroxyarylsulfide; 4,4'-dihydroxydi Dihydroxyarylsulfoxides such as phenylsulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfoxide;4,4'-dihydroxydiphenylketone,4,4'-dihydroxy-3,3' − Examples include dihydroxyarylketones such as dimethyldiphenylketone.

Preferred (B) polycarbonate resin includes bisphenol A type polycarbonate.

The polycarbonate resin (B) may be homopolycarbonate or copolycarbonate. In addition, one type of polycarbonate resin may be used alone, or two or more types may be used in combination.

From the viewpoint of improving alkali resistance, the polycarbonate resin (B) has a melt viscosity of 0.40 kPa · s or less at 300 ° C. and 1000 sec ^-1 in accordance with ISO11443. The melt viscosity of the polycarbonate resin (B) is preferably 0.35 kPa · s or less, and more preferably 0.30 kPa · s or less. The lower limit of the melt viscosity of the polycarbonate resin (B) is not particularly limited, but in double molding with the polycarbonate molded product, when the anchor structure is not provided on the surface of the polycarbonate molded product, the melt viscosity of the polycarbonate resin (B) is high. It is preferably 0.10 kPa · s or more, more preferably 0.15 kPa · s or more, and even more preferably 0.20 kPa · s or more. On the other hand, when the anchor structure is provided on the surface of the polycarbonate molded product, the melt viscosity of the (B) polycarbonate resin is preferably 0.01 kPa · s or more and 0.25 kPa · s or less, preferably 0.05 kPa · s or more. It is more preferably 0.20 kPa · s or less. The melt viscosity can be measured using a capillar graph manufactured by Toyo Seiki Seisakusho, using a 1 mmφ × 20 mm L / flat die as a capillary, a barrel temperature of 300 ° C., and a shear rate of 1000 sec ^-1 .

Further, the polycarbonate resin (B) preferably has a viscosity average molecular weight of 18,000 or less, and more preferably 17,000 or less. The viscosity average molecular weight (Mv) is the value measured by the ultimate viscosity [η] of the methylene chloride solution at 20 ° C. and measured by the Schnell formula ([η] = 1.23 × ^10-5 × Mv ^0.83 ). To do.

The content of the polycarbonate resin (B) is 35 parts by mass or more and 65 parts by mass or less, preferably 40 parts by mass or more and 60 parts by mass or less, and 40 parts by mass or more, based on 100 parts by mass of the polybutylene terephthalate resin composition. It is more preferably 50 parts by mass or less, and further preferably 40 parts by mass or more and 45 parts by mass or less. (B) When the content of the polycarbonate resin is 35 parts by mass or more, the effect of improving the adhesion at the time of double molding with the polycarbonate molded product can be obtained, and when it is 65 parts by mass or less, excellent alkali resistance is obtained. Can be obtained.

(C) Olefin-based elastomer The polybutylene terephthalate resin composition according to the present embodiment contains 10 parts by mass or more and 30 parts by mass or less of an olefin-based elastomer with respect to 100 parts by mass of the polybutylene terephthalate resin composition.

The content of the olefin-based elastomer (C) is preferably 12 parts by mass or more, more preferably 15 parts by mass or more, and 15.5 parts by mass or more with respect to 100 parts by mass of the polybutylene terephthalate resin composition. It is more preferable to have. The upper limit value is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and further preferably 18 parts by mass or less. (C) When the content of the olefin elastomer is 10 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the polybutylene terephthalate resin composition, the alkali resistance and the adhesion between the polycarbonate resin molded product and the molded product during double molding are improved. It can be improved in a well-balanced manner.

As the (C) olefin-based elastomer, a conventionally known olefin-based elastomer can be used. The conventionally known olefin-based elastoma is selected from, for example, an ethylene-propylene copolymer (EP copolymer), an ethylene-propylene-diene copolymer (EPD copolymer), an EP copolymer, and an EPD copolymer. A copolymer containing at least one of the above-mentioned units, a copolymer of an olefin and a (meth) acrylic monomer, and the like are included. Preferred olefin-based elastomers include EP copolymers, EPD copolymers, and copolymers of olefins and (meth) acrylic monomers. Of these, a copolymer of an olefin and a (meth) acrylic monomer is preferable. Among the copolymers of the olefin and the (meth) acrylic monomer, the EEA copolymer (ethylene ethyl acrylate copolymer) is particularly preferable.

The EEA copolymer is a copolymer containing ethylene and ethyl acrylate as copolymerization components. The copolymerization type is not particularly limited, and may be a random, block, or graft copolymer, for example, partially having two or more structures of a random structure, a block structure, and a graft structure. Good.
The ratio of ethylene to ethyl acrylate in the copolymer is not particularly limited, but the melting point of the EEA copolymer is 85 ° C. or higher from the viewpoint of ensuring compatibility with the PBT resin and suppressing blocking during production. It is preferably 88 ° C. or higher, and particularly preferably 90 ° C. or higher.

In the present embodiment, it is preferable to use an EEA copolymer that does not substantially contain a comonomer component other than ethylene and ethyl acrylate, but other comonomer components may be partially contained as long as the effects of the present embodiment are not impaired. It may be included. Specifically, the amount of comonomer other than ethylene and ethyl acrylate is preferably 10% by mass or less in the copolymerized monomer. Examples of other comonomer include maleic anhydride, butyl acrylate, (meth) acrylic acid ester such as methyl methacrylate, and the like, and it is a comonomer that does not contain a highly reactive functional group such as a glycidyl group. preferable.

The EEA copolymer can be produced by any method. For example, an EEA copolymer can be obtained by mixing a predetermined amount of ethylene and ethyl acrylate (and other comonomer components) and performing radical polymerization by a conventional method using a radical initiator.

One type of olefin elastomer may be used alone, or two or more types may be used in combination.

(D) Silicone-based compound The polybutylene terephthalate resin composition of the present embodiment has high alkali resistance by containing the (D) silicone-based compound.

Preferred silicone-based compounds are pure silicone resins such as dimethylpolysiloxane, methylphenylpolysiloxane, and diphenylpolysiloxane, which are generally known as silicone oils, and pure silicone resins as alkyd resins, polyester resins, acrylic resins, and epoxy resins. Examples thereof include modified silicone obtained by reacting with a modifying resin such as, but the present invention is not limited to this.

Further, a cured silicone powder that has absorbed silicone oil can also be used. The silicone oil absorption-curing silicone powder used here is obtained by preliminarily blending 0.5 to 80% by weight of silicone oil into a fine powder-like cured silicone, absorbing it, and powdering it by an arbitrary method. is there.
As the silicone that absorbs the silicone oil to form the cured silicone powder, for example, a conventionally known silicone rubber or silicone gel can be used.

As the silicone oil, for example, the following general formula (1)
R ₃ SiO [R ₂ SiO] nSiR ₃ (1)
(In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group or hydroxyl group, and n is an integer.).
In the above formula, R is a substituted or unsubstituted monovalent hydrocarbon group or hydroxyl group, and examples of the substituted or unsubstituted monovalent hydrocarbon group include alkyl groups such as methyl group, ethyl group and propyl group. Group; Alkenyl group such as vinyl group and allyl group; Aralkyl group such as cycloalkyl group and β-phenylethyl group; 3,3,3-trifluoropropyl group, 3-mercaptopropyl group, 3-aminopropyl group, 3 -Glysidoxypropyl group and the like. All Rs may be the same or different.

The silicone-based compound (D) according to the present embodiment has a kinematic viscosity of 1000 to 10000 cSt (10 to 100 cm ² / s) at 25 ° C., and is preferably 2000 to 8000 cSt, particularly 3000 to 0, from the viewpoint of further enhancing alkali resistance. It is preferably in the range of 6000 cSt. For the kinematic viscosity, 10 ml of a silicone compound kept at 25 ° C. is set in an Ostwald viscometer (capillary viscometer), and the time t at which the upper surface of the measuring solution passes a certain distance is measured. Assuming that the viscosity of the reference liquid is η0, the density is ρ0, and the flow time is t0, the kinematic viscosity is
Kinematic viscosity (cSt) = (η0 / ρ0) × (t / t0)
Can be calculated by Further, for the kinematic viscosity, the catalog value of the silicone compound manufacturer can be used.

(D) One type of silicone compound may be used alone, or two or more types may be used in combination.

The content of the silicone-based compound (D) is 1 part by mass or more and 3 parts by mass or less, preferably 1.5 parts by mass or more and 3 parts by mass or less, based on 100 parts by mass of the polybutylene terephthalate resin composition. It may be 5 parts by mass or more and 2.5 parts by mass or less. When the content of the silicone compound (D) is 1 part by mass or more, the effect of improving alkali resistance can be obtained, and when it is 3 parts by mass or less, the adhesion to the polycarbonate resin molded product at the time of double molding is obtained. It is preferable because it does not impair.

(E) Filler The polybutylene terephthalate resin composition of the present embodiment contains (E) a filler. By containing the (E) filler, the mechanical properties can be improved. Further, since the ratio of the resin component in the total composition is lowered, it is advantageous in terms of alkali resistance. Further, the molding shrinkage rate and the linear expansion coefficient of the polybutylene terephthalate resin composition can be reduced, and improvement in heat shock resistance can be expected.

Examples of the filler (E) include fibrous fillers [for example, glass fiber, asbestos fiber, carbon fiber, silica fiber, alumina fiber, silica / alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber. , Inorganic fibers such as potassium titanate fiber, silicon carbide fiber, whisker (whisker such as silicon carbide, alumina, silicon nitride), organic fiber formed of polyamide, fluororesin, etc.], Plate-like filler [for example, Talk, mica, glass flakes, graphite, etc.], powder fillers [eg, glass beads, glass powder, milled fiber (milled fiber such as glass), wollastonite, etc.]. Among these fillers, glass-based fillers (glass fiber, glass flakes, glass beads, etc.), talc, mica, wollastonite, etc. are preferable, and glass fiber is particularly preferable in terms of availability, strength, and rigidity. Can be used for. Further, the plate-shaped or powder-shaped filler can be preferably used from the viewpoint of suppressing the anisotropy of the molding shrinkage rate and the linear expansion coefficient of the polyalkylene terephthalate resin composition. In using these fillers, known surface treatment agents can be used if necessary.

(E) When a fibrous filler is used as the filler, its shape is not particularly limited, but for example, the average length is about 100 μm to 5 mm, more preferably about 500 μm to 3 mm, and the average diameter is, for example, 1 to 50 μm. It is preferably about 3 to 30 μm. When a plate-shaped filler or a powder-shaped filler is used, the average particle size thereof is not particularly limited, but is, for example, 0.1 to 100 μm, more preferably 0.1 to 50 μm. These (E) fillers can be used alone or in combination of two or more. For the "average length" and "average diameter", the length of several tens (for example, 50) fiber pieces and the longest linear distance of the cross section are measured using a scanning electron microscope and image processing software. , The average value. The "average particle size" means a median diameter of 50% of the integrated value in the particle size distribution measured by the laser diffraction / scattering method.

The amount of the filler (E) added is 30 parts by mass or more and 80 parts by mass or less, preferably 30 parts by mass or more and 70 parts by mass or less, and more preferably 40 parts by mass with respect to 100 parts by mass of the polybutylene terephthalate resin composition. It is by mass or more and 70 parts by mass or less, and more preferably 50 parts by mass or more and 60 parts by mass or less. By setting the amount of the filler added to 30 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the polybutylene terephthalate resin composition, alkali resistance is not impaired during double molding with a polycarbonate resin molded product. And heat shock resistance can be improved.

(F) Epoxy-based compound The polybutylene terephthalate resin composition of the present embodiment has excellent alkali resistance due to the inclusion of (F) epoxy-based compound and excellent adhesion in a double-molded product with a polycarbonate molded product. ..

(F) As the epoxy compound, one having one or more epoxy groups in one molecule and having an epoxy equivalent of 500 g / eq or more and 2000 g / eq or less is used. When the epoxy equivalent is within this range, the effect of improving the alkali resistance can be obtained without causing problems such as thickening and foreign matter of the polybutylene terephthalate resin composition. The epoxy equivalent (g / eq) is more preferably 650 or more and 700 or more in this order, while it is further preferably 1200 or less, 1100 or less, and 1000 or less in this order.

The epoxy compound (F) is not particularly limited as long as it has the above epoxy equivalent, but it is preferable to use an aromatic epoxy compound from the viewpoint of enhancing thermal stability and hydrolysis resistance. Examples of aromatic epoxy compounds include biphenyl type epoxy compounds, bisphenol A type epoxy compounds, phenol novolac type epoxy compounds, cresol novolac type epoxy compounds, and the like, and two or more of these are used in combination. You may.

The polybutylene terephthalate resin composition according to the present embodiment contains the above-mentioned (A) polybutylene terephthalate resin, (B) polycarbonate resin, (C) olefin-based epoxy, and (D) silicone-based compound, depending on the purpose. Ingredients other than E) filler and (F) epoxy compound may be optionally contained. Other components include antioxidants, stabilizers, molecular weight modifiers, UV absorbers, antistatic agents, colorants, lubricants, mold release agents, crystallization accelerators, crystal nucleating agents, infrared absorbers, flame retardants. , Flame retardant aid, hydrolysis resistance improver, fluidity improver and the like, but are not limited thereto. The stabilizer added to the polybutylene terephthalate resin composition according to the present embodiment is a phosphorus-based stabilizer in order to suppress transesterification between the (A) polybutylene terephthalate resin and the (B) polycarbonate resin. It is preferable to add (such as a metal phosphate such as primary calcium phosphate).

In the polybutylene terephthalate resin composition according to the present embodiment, the total content of the components (A) to (F) is preferably 70% by mass or more, preferably 80% by mass or more in the total composition. Is more preferable, and 90% by mass or more is further preferable. The upper limit is not particularly limited and may be 100% by mass. By setting the total content of the components (A) to (F) within the above range, it is possible to obtain a resin composition having better alkali resistance and adhesion in double molding with a polycarbonate molded product.

<Double molded product>
A double-molded product obtained by double-molding the polybutylene terephthalate resin composition according to the present embodiment with a polycarbonate molded product will be described.

One aspect of the present invention relates to a molded product formed by using the above-mentioned polybutylene terephthalate resin composition, which is obtained by double molding a molded product made of a polycarbonate resin composition. That is, one aspect of the present invention relates to a double-molded article obtained by injection molding the above-mentioned polybutylene terephthalate resin composition so as to be in contact with at least a part of the preformed polycarbonate resin composition molded article. The double-molded article has a portion containing the above-mentioned polybutylene terephthalate resin composition and a portion containing a polycarbonate resin composition, and includes a portion containing the polybutylene terephthalate resin composition and a portion containing the polycarbonate resin composition. Is in contact with at least part of it. The double-molded product may be formed, for example, so that at least one side of the plate-shaped polybutylene terephthalate resin composition molded product is in contact with at least one side of the plate-shaped polycarbonate resin composition molded product, or polybutylene. The portion containing the terephthalate resin composition may be formed so as to cover the entire portion containing the polycarbonate resin composition. Since the polybutylene terephthalate resin composition is as described above, the description thereof is omitted here.
The polycarbonate resin composition contains a polycarbonate resin as a main component. Examples of the polycarbonate resin include a polymer obtained by reacting a dihydroxy compound with a carbonic acid ester such as phosgene or diphenyl carbonate. The dihydroxy compound is not particularly limited, and for example, it can be selected and used from those described in the above-mentioned (B) polycarbonate resin.
The polycarbonate resin may have the same composition as the (B) polycarbonate resin, or may have a different composition. The viscosity average molecular weight and the melt viscosity (the melt viscosity at 300 ° C. and 1000 sec ^-1 according to ISO11443) of the polycarbonate resin constituting the polycarbonate molded product are not particularly limited.
The polycarbonate resin composition may contain an inorganic filler and an elastoma, if necessary, and further, an antioxidant, a stabilizer, a molecular weight modifier, an ultraviolet absorber, an antistatic agent, a colorant, a lubricant, and a release agent. Additives such as a mold agent, a crystallization accelerator, a crystal nucleating agent, an ultraviolet absorber, a flame retardant, a flame retardant aid, a hydrolysis resistance improver, and a fluidity improver may be contained. Examples of the inorganic filler, elastomer and other additives include the same inorganic filler, elastomer and other additives that can be contained in the polybutylene terephthalate resin composition described above.
The method for obtaining the double-molded article according to the present embodiment is not particularly limited, and a known method can be adopted. For example, a molded product (polycarbonate molded product) obtained by injection molding a polycarbonate resin composition in advance is placed in a mold cavity, and a polybutylene terephthalate resin composition is injection molded onto the polycarbonate molded product. A molded product can be obtained. Here, as the polycarbonate resin composition used for the polycarbonate molded product, 50% by mass or more of the resin components in the total composition is a polycarbonate resin. The ratio of the polycarbonate resin in the resin component of the polycarbonate resin composition is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and 90% by mass. The above is particularly preferable, and 95% by mass or more is most preferable.

The double-molded product according to the present embodiment may be an insert-molded product obtained by injection molding together with an insert member made of a metal (alloy) and / or an inorganic solid. The material of the metal (alloy) and / or the inorganic solid is not limited.
The manufacturing method of the insert molded product is not particularly limited. For example, a molded product (polycarbonate molded product) obtained by injection molding a polycarbonate resin composition in advance is placed in a mold cavity together with an insert member made of a metal and / or an inorganic solid, and the polycarbonate molded product and the insert are placed. A double-molded product can be obtained by injection molding a polybutylene terephthalate resin composition onto a member.
Further, when the polycarbonate molded product is injection-molded, an insert member made of metal and / or an inorganic solid is placed in the mold and the polycarbonate resin is injection-molded on the insert member to obtain a polycarbonate molded product having the insert member. After obtaining the product, a double-molded product can also be obtained by injection-molding the polybutylene terephthalate resin composition in a state where the polycarbonate molded product having the insert member is placed in the mold cavity.
Since the molded product according to this embodiment has excellent heat shock resistance in addition to alkali resistance and adhesion to the polycarbonate molded product, it is a double-molded product (or insert-molded product) particularly used as a part in contact with an alkaline solution. Can be suitably applied as. The term "in contact with an alkaline solution" includes not only a state of constant contact with an alkaline solution but also a state of temporary contact with an alkaline solution. Examples of the alkaline solution include detergents, bleaching agents, snow melting agents and the like. Applications of the double-molded product include, for example, automobile parts, electric parts, water parts, and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[Examples 1 to 6, Comparative Examples 1 to 16]
The components shown in Table 1 are mixed at the ratio (parts by mass) shown in the same table, and then melt-kneaded and extruded at a cylinder temperature of 270 ° C. using a twin-screw extruder (TEX44αII manufactured by Japan Steel Works) to extrude a polybutylene terephthalate resin. Pellets of the composition were obtained.

Details of each component used in Examples and Comparative Examples are shown below.
-PBT resin: Polybutylene terephthalate resin with intrinsic viscosity (IV) = 0.85 dL / g manufactured by Wintech Polymer Co., Ltd.-PC resin 1: Polycarbonate resin with melt viscosity 0.42 kPa · s (viscosity average molecular weight 22500) -PC Resin 2: Polycarbonate resin having a melt viscosity of 0.29 kPa · s (viscosity average molecular weight 19500)
-PC resin 3: Polycarbonate resin with a melt viscosity of 0.09 kPa · s (viscosity average molecular weight 16000)
Elastomer 1: Ethylene ethyl acrylate copolymer (ethylene content 75% by mass, melting point 91 ° C)
-Elastomer 2: Acrylic core-shell polymer (manufactured by Rohm and Haas Japan, Pararoid EXL2311)
-Elastomer 3: Acrylic core-shell polymer (manufactured by Rohm and Haas Japan, Pararoid EXL2314)
Silicone compound 1: Dimethylpolysiloxane with a kinematic viscosity of 60,000 cSt at 25 ° C. Silicone compound 2: Didimethylpolysiloxane with a kinematic viscosity of 5000 cSt at 25 ° C. Silicone compound 3: Didimethylpolysiloxane with a kinematic viscosity of 300 cSt at 25 ° C. Filling. Agent: Glass fiber (ECS03T-127 manufactured by Nippon Electric Glass Co., Ltd., average fiber diameter 13 μm, average fiber length 3 mm)
-Epoxy compound: Epoxy resin: Mitsubishi Chemical Corporation Epicoat JER1004K
-Stabilizer: Daihei Kagaku Sangyo Co., Ltd. First calcium phosphate-Anti-oxidant: BASF Japan Co., Ltd. Irganox1010
-Colorant (carbon black): Colombian Carbon Japan Co., Ltd. Raven UV Ultra

<Evaluation>
(1) Alkali resistance The pellets of the obtained polybutylene terephthalate resin composition were dried at 140 ° C. for 3 hours and then injection molded at a cylinder temperature of 250 ° C. and a mold temperature of 70 ° C. to have a thickness of 1 mmt and a side of 120 mm. A molded piece having a welded portion was produced in the form of a flat plate. Next, a test piece was prepared by cutting this molded piece into a strip shape having a width of 10 mm and a length of 100 mm so that a substantially central portion in the longitudinal direction became a weld portion. This test piece was fixed to a jig in a bent state so that 1.0% bending strain was always applied to the weld portion. In this state, the jig was immersed in a 10 mass% sodium hydroxide aqueous solution, allowed to stand at an ambient temperature of 23 ° C., and the test piece after immersion for 60 hours was observed to see if cracks were generated. The evaluation was performed using three test pieces for each of the pellets of Examples and Comparative Examples, and the case where no cracks were generated in any of the three test pieces was excellent, and only one of the three test pieces was evaluated. The case where a crack occurred was evaluated as good, and the case where a crack occurred in all three test pieces was evaluated as a defect. The results are shown in Table 1.

(2) Bond strength 1 of double-molded product (double moldability 1)
As a primary molded product, after drying the above-mentioned PC resin 2 at 120 ° C. for 5 hours, an Izod test piece (63.5 mm ×) conforming to ASTM D256 at a cylinder temperature of 280 ° C., a mold temperature of 100 ° C., and a holding pressure of 98 MPa. 12.7 mm x 6.4 mm) was injection molded and left to stand at 23 ° C. and 50% RH for 24 hours, and this was prepared as a cavity (127 mm x 127 mm x) for forming a bending test piece according to ASTM D790. It was installed in 12.7 mm × 6.4 mm) so as to be in contact with one end surface of the mold. Next, the polybutylene terephthalate resin composition of each example dried at 140 ° C. for 3 hours was subjected to the rest of the cavity of the bending test piece molding mold at a cylinder temperature of 270 ° C., a mold temperature of 70 ° C., and a holding pressure of 78 MPa. One end surface of the molded product of PC resin 2 and one end surface of the molded product made of the polybutylene terephthalate resin composition of each example are formed by injection molding in the space (63.5 mm × 12.7 mm × 6.4 mm). A double-molded product of 127 mm × 12.7 mm × 6.4 mm in a joined state was obtained. Using the obtained double-molded product, a tensile test was performed according to ISO527-1 and 2, the joint strength was measured, and the double moldability was evaluated as 1. The evaluation criteria were excellent when the bonding strength was 20 MPa or more, good when it was 10 MPa or more and less than 20 MPa, and defective when it was less than 10 MPa. The results are shown in Table 1.

(3) Bond strength 2 of double-molded product (double moldability 2)
In the above evaluation of the double moldability 1, for the primary molded product made of the PC resin 2, the end face (12.7 mm × 6.4 mm) bonded to the polybutylene terephthalate resin composition was formed on a smooth mold transfer surface. Although it was double-molded in this state, 4 grooves having a length of 12.7 mm, a width of 0.8 mm, and a depth of 0.8 mm were formed so as to form a striped shape parallel to the side of 12.7 mm with respect to the end face to be joined. It was formed by cutting so that the distance between the book and the groove was 0.8 mm, and double molding was performed with this as a primary molded product installed in the mold cavity. When the polybutylene terephthalate resin composition is joined in the groove formed on the end face, the joining strength is expected to be further improved by the physical anchor effect. The joint strength of the double-molded product was evaluated in the same manner as in the double moldability 1, and the case where the joint strength was 30 MPa or more was evaluated as excellent, and the case where the joint strength was 20 MPa or more and less than 30 MPa was evaluated as good. The results are shown in Table 1.

As shown in Table 1, it can be seen that the polybutylene terephthalate resin compositions of Examples 1 to 6 are excellent in alkali resistance and have high bonding strength when made into a double-molded product with a polycarbonate molded product.

According to the present invention, it is possible to obtain a polybutylene terephthalate resin composition capable of molding a molded product having excellent bonding strength in a double-molded product with a polycarbonate resin molded product in addition to alkali resistance. -It can be suitably used in a wide range of fields such as electronics, automobiles, and general miscellaneous goods, especially in applications in contact with alkaline solutions.

Claims (8)

(A) 100 parts by mass of polybutylene terephthalate resin,
(B) Polycarbonate resin 35 to 65 parts by mass,
(C) 10 to 30 parts by mass of an olefin elastomer,
(D) 1 to 3 parts by mass of silicone compound,
(E) 30 to 80 parts by mass of the filler and (F) 1 to 5 parts by mass of the epoxy compound.
The melt viscosity of the polycarbonate resin (B) at 300 ° C. and 1000 sec ^-1 is 0.40 kPa · s or less.
The kinematic viscosity of the silicone compound (D) at 25 ° C. is 1000 to 10000 cSt.
A polybutylene terephthalate resin composition for double molding with a molded product of a polycarbonate resin composition. The polybutylene terephthalate resin composition according to claim 1, wherein the silicone-based compound (D) contains dimethylpolysiloxane. The polybutylene terephthalate resin composition according to claim 1 or 2, wherein the (C) olefin-based elastomer comprises an ethylene ethyl acrylate copolymer. The polybutylene terephthalate resin composition according to any one of claims 1 to 3, wherein the filler (E) contains a fibrous filler. The polybutylene terephthalate resin composition according to any one of claims 1 to 4, wherein the polycarbonate resin (B) has a viscosity average molecular weight of 18,000 or less. It has a portion containing the polybutylene terephthalate resin composition according to any one of claims 1 to 5 and a portion containing a polycarbonate resin composition.
A double-molded article in which a portion containing a polybutylene terephthalate resin composition and a portion containing a polycarbonate resin composition are in contact with each other at least in part. The double-molded product according to claim 6, further comprising an insert member made of a metal and / or an inorganic solid. The double-molded article according to claim 6 or 7, which is used as a part in contact with an alkaline solution.