WO2020116629A1

WO2020116629A1 - Polybutylene terephthalate resin composition and double-molded article

Info

Publication number: WO2020116629A1
Application number: PCT/JP2019/047874
Authority: WO
Inventors: 耕一坂田
Original assignee: ポリプラスチックス株式会社
Priority date: 2018-12-07
Filing date: 2019-12-06
Publication date: 2020-06-11
Also published as: JP6836695B2; CN113165236B; CN113165236A; JPWO2020116629A1

Abstract

[Problem] To provide: a polybutylene terephthalate resin composition that can be used to form a molded product having excellent alkali resistance, and in addition, excellent bonding strength in a double-molded article with a polycarbonate resin molded article; and a double-molded article firmly bonded to a polycarbonate resin molded article using the resin composition. [Solution] This polybutylene terephthalate resin composition is for double-molding with respect to a molded article of a polycarbonate resin composition, and contains (A) 100 parts by mass of a polybutylene terephthalate resin, (B) 35-65 parts by mass of a polycarbonate resin having a melt viscosity of 0.40 kPa·s or less at 300°C, (C) 10-30 parts by mass of an olefin elastomer, (D) 1-3 parts by mass of a silicone compound having a kinematic viscosity of 1000-10000 cSt at 25°C, (E) 30-80 parts by mass of a filler, and (F) 1-5 parts by mass of an epoxy compound.

Description

Polybutylene terephthalate resin composition and double molded article

The present invention relates to a polybutylene terephthalate resin composition and a double molded product.

Polybutylene terephthalate resin is a crystalline thermoplastic resin that has excellent mechanical strength, electrical properties, and other various characteristics. Therefore, it is used as a engineering plastic in a wide range of applications including automobiles, electric and electronic devices, etc. Has been done. However, the polybutylene terephthalate resin tends to have low long-term durability against an alkaline solution, and its use environment and applications have been limited. For example, some parts are used in places where they come into contact with toilet cleaners, bath cleaners, bleaches, snow melting agents, and the like. Since these agents contain sodium hydroxide, sodium hypochlorite, sodium percarbonate, calcium chloride, etc. as their components, the resin molded product is exposed to an alkaline atmosphere. If the resin molded product is exposed to excessive strain due to screw tightening, metal press fitting, caulking, etc. for a long time and is exposed to the alkaline atmosphere as described above, it will be affected by both strain and alkaline components and This has been a problem because stress cracking occurs and cracks occur in the molded product.
In addition, the polybutylene terephthalate resin is often used as an insert molded product into which a metal or an inorganic solid (hereinafter, also referred to as a 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 a metal or the like and merges during injection molding. Generally, the above-mentioned environmental stress cracking often occurs in the weld portion of a molded product. Furthermore, since resin and metal have different shrinkage rates and linear expansion coefficients, insert-molded products that are used in environments where temperature rises and falls are repeated can cause cracks (heat shock damage) due to strain in the resin surrounding metal and other materials. ) Is easy to occur. Therefore, when the insert-molded product is contacted with the alkaline solution as described above, and is placed in an environment where the temperature is raised or lowered repeatedly for a long period of time, cracks are generated around the weld portion or the metal, which causes a problem. Was becoming.

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

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

Further, in Patent Document 2, a polybutylene terephthalate resin, a silicone compound having a kinematic viscosity at 25° C. of 1000 to 10000 cSt, and an olefin elastomer are mixed in predetermined amounts, respectively, and alkali resistance and heat shock resistance. An excellent polybutylene terephthalate resin composition is disclosed.

Further, in Patent Document 3, (A) a polybutylene terephthalate-based resin having an isophthalic acid component content of 3 to 30 mol% with respect to all dicarboxylic acid components, (B) a polycarbonate resin, (C) an elastomer, (D). ) Disclosed is a polyester resin composition which comprises a fibrous reinforcing material and a silicone compound (E) in predetermined amounts, and is excellent in alkali resistance and mechanical strength.

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

However, molded articles made of these polybutylene terephthalate resin compositions are not only insert molded articles made of metal or the like, but also molded articles made of other resin compositions, such as molded articles made of a polycarbonate resin composition. It may be used in combination with a member (such as an optical component). In such a case, a secondary process such as adhesion or welding is often used for joining the molded products, but it is preferable that they can be integrated by double molding from the viewpoint of process simplification. Therefore, a polybutylene terephthalate resin composition which is also excellent in bondability at the time of double molding with a molded article made of a polycarbonate resin composition (hereinafter, also referred to as “polycarbonate resin molded article” or “polycarbonate resin composition molded article”). Things are needed.

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

The present invention relates to the following items.
[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 elastomer, and (D) silicone compound. 1 to 3 parts by mass, (E) 30 to 80 parts by mass of the filler, and (F) 1 to 5 parts by mass of the epoxy compound, and the melt viscosity of the (B) polycarbonate resin at 300° C. and 1000 sec ⁻¹ is 0. The present invention relates to a polybutylene terephthalate resin composition for double molding with a molded article of a polycarbonate resin composition, in which the kinematic viscosity of the silicone compound (D) at 25° C. is 1,000 to 10,000 cSt.
[2] A further aspect of the present invention relates to the polybutylene terephthalate resin composition according to [1], wherein the silicone 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 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 (B) polycarbonate resin has a viscosity average molecular weight of 18,000 or less.
[6] In another aspect of the present invention, the polybutylene terephthalate resin composition according to any one of [1] to [5] is double molded with a molded article 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 the polycarbonate resin composition, and 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 that comes into contact with an alkaline solution.

According to the embodiment of the present invention, in addition to alkali resistance, 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, and the resin composition It is possible to provide a double molded product that is firmly bonded to the polycarbonate resin molded product by using the product.

<Polybutylene terephthalate resin composition>
In the present embodiment, the polybutylene terephthalate resin composition (hereinafter, also simply referred to as “resin composition”) includes a polybutylene terephthalate resin, a specific amount of a polycarbonate resin, and a specific amount of an olefinic elastomer. A specific amount of a filler, a specific amount of a silicone compound having a kinematic viscosity at 25° C. of 1000 to 10,000 cSt, and a specific amount of an epoxy compound are contained. By using such a resin composition, it is possible to mold a molded article which is excellent in not only the alkali resistance but also the joint strength in the double molded article with the polycarbonate resin molded article.
In the present specification, the "double-molded article" means a molded article in which another resin layer is injection-molded so as to come into 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.

Each component used in the resin composition of this embodiment will be described below.

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

The amount of terminal carboxyl groups of the (A) polybutylene terephthalate resin is not particularly limited as long as the object of the present invention is not impaired. The amount of terminal carboxyl groups of the (A) polybutylene terephthalate resin used in this 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 an amount of terminal carboxylsyl groups within such a range, the resulting polybutylene terephthalate resin composition is less likely to undergo strength reduction due to hydrolysis in a wet heat environment.

The intrinsic viscosity (IV) of the (A) polybutylene terephthalate resin 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, It is more preferably 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 becomes particularly excellent in moldability and mechanical properties. .. Also, the intrinsic viscosity can be adjusted by blending polybutylene terephthalate resins having different intrinsic viscosities. For example, a polybutylene terephthalate resin having an intrinsic viscosity of 0.85 dL/g is 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. You can The intrinsic viscosity (IV) of the (A) polybutylene terephthalate resin can be measured, for example, in o-chlorophenol at a temperature of 35°C.

In the polybutylene terephthalate resin (A), examples of the dicarboxylic acid component (comonomer component) other than terephthalic acid and its ester-forming derivative include, for example, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′- C _8-14 aromatic dicarboxylic acid such as dicarboxydiphenyl ether; C _4-16 alkanedicarboxylic acid such as succinic acid, adipic acid, azelaic acid, sebacic acid; C _5-10 cycloalkanedicarboxylic acid such as cyclohexanedicarboxylic acid Acids; examples thereof include ester-forming derivatives of 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 polybutylene terephthalate resin (A), 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 glycol and 1,3-octanediol; polyoxyalkylene glycols such as diethylene glycol, triethylene glycol and dipropylene glycol; alicyclic diols such as cyclohexanedimethanol and hydrogenated 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 adduct of bisphenol A and propylene oxide 3 mol adduct of bisphenol A Or an ester-forming derivative of these glycols (acetylated product, etc.). 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 comonomer components that can be used in addition to the dicarboxylic acid component and the glycol component include, for example, 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 Formable derivatives (C _1-6 alkyl ester derivatives, acid halides, acetylated compounds, etc.) can be mentioned.

Any of the polybutylene terephthalate copolymers obtained by copolymerizing the comonomer components described above can be suitably used as the (A) polybutylene terephthalate resin. 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 containing no copolymerization component.

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

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

Examples of dihydroxy compounds include alicyclic compounds (eg, alicyclic diols) and bisphenol compounds, with bisphenol compounds being preferred.

Examples of the bisphenol compound include bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3-methylphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 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-indene]-6,6'- Bis(hydroxyaryl)C _1-10 alkane such as diol, preferably bis(hydroxyaryl)C _1-6 alkane; 1,1-bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxy) Phenyl)cyclohexane and other bis(hydroxyaryl)C _4-10 cycloalkanes; 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether and other dihydroxyaryl ethers; 4,4′ -Dihydroxyarylsulfones such as dihydroxydiphenylsulfone and 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone;4,4'-dihydroxydiphenylsulfide,4,4'-dihydroxy-3,3'-dimethyldiphenylsulfide And other dihydroxyaryl sulfides; 4,4'-dihydroxydisulfide Dihydroxyaryl sulfoxides such as phenyl sulfoxide and 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfoxide; 4,4′-dihydroxydiphenyl ketone and 4,4′-dihydroxy-3,3′ -Dihydroxy aryl ketones such as dimethyl diphenyl ketone.

As a preferable (B) polycarbonate resin, bisphenol A type polycarbonate can be mentioned.

The (B) polycarbonate resin may be a homopolycarbonate or a copolycarbonate. Further, the polycarbonate resins may be used alone or in combination of two or more.

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 according to ISO11443. The melt viscosity of the (B) polycarbonate resin 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 (B) polycarbonate resin is not particularly limited, but in the 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 (B) polycarbonate resin is It is preferably 0.10 kPa·s or more, more preferably 0.15 kPa·s or more, and further preferably 0.20 kPa·s or more. On the other hand, when an 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, and 0.05 kPa·s or more. It is more preferably 0.20 kPa·s or less. The melt viscosity can be measured by using a Capillograph manufactured by Toyo Seiki Seisaku-sho, using a 1 mmφ×20 mmL/flat die as a capillary at a barrel temperature of 300° C. and a shear rate of 1000 sec ⁻¹ .

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

The content of the (B) polycarbonate resin 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 with respect to 100 parts by mass of the polybutylene terephthalate resin composition. The amount is more preferably 50 parts by mass or less, 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 is obtained, and when it is 65 parts by mass or less, excellent alkali resistance. 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 the olefinic elastomer with respect to 100 parts by mass of the polybutylene terephthalate resin composition.

The content of the olefinic 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. More preferably, 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. When the content of the (C) olefinic 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 at the time of double molding with the polycarbonate resin molded article are improved. It can be improved in a well-balanced manner.

As the (C) olefin elastomer, a conventionally known olefin elastomer can be used. The conventionally known olefin elastomer is, for example, selected from ethylene-propylene copolymer (EP copolymer), ethylene-propylene-diene copolymer (EPD copolymer), EP copolymer and EPD copolymer. And a copolymer of at least one unit, a copolymer of an olefin and a (meth)acrylic monomer, and the like. Preferred olefinic 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 olefin and (meth)acrylic monomer, EEA copolymer (ethylene ethyl acrylate copolymer) is particularly preferable.

The EEA copolymer is a copolymer containing ethylene and ethyl acrylate as a copolymerization component. The copolymerization form 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 and ethyl acrylate in the copolymer is not particularly limited, but from the viewpoint of ensuring compatibility with the PBT resin and suppressing blocking during production, the melting point of the EEA copolymer is 85°C or higher. It is preferable that the temperature is 88°C or higher, more preferably 88°C or higher, 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 within a range that does not impair the effects of the present embodiment. May be included. Specifically, the amount of the comonomer other than ethylene and ethyl acrylate is preferably 10% by mass or less in the copolymerization monomer. Examples of the other comonomer include maleic anhydride, butyl acrylate, (meth)acrylic acid ester such as methyl methacrylate, and the like, and the comonomer 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.

Olefin elastomers may be used alone or in combination of two or more.

(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 as the silicone compound are pure silicone resins such as dimethylpolysiloxane, methylphenylpolysiloxane, and diphenylpolysiloxane, which are generally known as silicone oils, pure silicone resins are alkyd resins, polyester resins, acrylic resins, epoxy resins. Examples include, but are not limited to, modified silicones that have been reacted with a modifying resin such as

Further, a cured silicone powder in which silicone oil is absorbed can also be used. The silicone oil absorption cured silicone powder used here is obtained by mixing 0.5 to 80% by weight of silicone oil in advance with finely powdered cured silicone, absorbing it, and powdering it by an arbitrary method. is there.
As the silicone that absorbs silicone oil to form a cured silicone powder, for example, 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 a hydroxyl group, and n is an integer.).
In the above formula, R is a substituted or unsubstituted monovalent hydrocarbon group or a hydroxyl group, and examples of the substituted or unsubstituted monovalent hydrocarbon group include, for example, an alkyl group such as a methyl group, an ethyl group and a 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 -Glycidoxypropyl group and the like. All R may be the same or different from each other.

The (D) silicone compound according to the present embodiment has a kinematic viscosity at 25° C. of 1000 to 10000 cSt (10 to 100 cm ² /s), and preferably 2000 to 8000 cSt, and particularly 3000 to 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 measurement liquid passes a certain distance is measured. When the viscosity of the reference liquid is η0, the density is ρ0, and the flow-down time is t0, the kinematic viscosity is
Kinematic viscosity (cSt)=(η0/ρ0)×(t/t0)
Can be calculated by Further, as the kinematic viscosity, a catalog value of a silicone compound manufacturer can be used.

The (D) silicone compound may be used alone or in combination of two or more.

The content of the silicone 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, and 100 parts by mass of the polybutylene terephthalate resin composition. The amount can be 5 parts by mass or more and 2.5 parts by mass or less. If the content of the (D) silicone compound is 1 part by mass or more, the effect of improving the alkali resistance is obtained, and if it is 3 parts by mass or less, the adhesion to the polycarbonate resin molded article at the time of double molding 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 filler (E), mechanical properties can be improved. Further, since the ratio of the resin component in the whole composition is lowered, it is advantageous in terms of alkali resistance. Furthermore, the molding shrinkage and 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]. , Potassium titanate fibers, silicon carbide fibers, inorganic fibers such as whiskers (whiskers such as silicon carbide, alumina, and silicon nitride), organic fibers formed of polyamide, fluororesin, and the like], plate-like filler [for example, Talc, mica, glass flakes, graphite, etc.] and powdery 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 among them, glass fiber is preferable from the viewpoint of availability, strength and rigidity. Can be used for Further, the plate-like or powdery filler can be preferably used from the viewpoint of suppressing the anisotropy of the molding shrinkage ratio and the linear expansion coefficient of the polyalkylene terephthalate resin composition. In using these fillers, a known surface treatment agent can be used, if necessary.

When a fibrous filler is used as the (E) filler, its shape is not particularly limited, but its average length is, for example, 100 μm to 5 mm, more preferably 500 μm to 3 mm, and its average diameter is, for example, 1 to 50 μm. It is preferably about 3 to 30 μm. When a plate-like filler or powdery filler is used, the average particle size is not particularly limited, but is, for example, 0.1 to 100 μm, more preferably about 0.1 to 50 μm. These (E) fillers can be used alone or in combination of two or more. The "average length" and "average diameter" are measured using a scanning electron microscope and image processing software to measure the length of several tens of fiber pieces (for example, 50) and the longest linear distance of the cross section. , And its average value. The “average particle diameter” means a median diameter with an integrated value of 50% in a particle size distribution measured by a 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. The amount is not less than 70 parts by mass and more preferably not less than 50 parts by mass and not more than 60 parts by mass. By adding the filler in an amount of 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 maintained without impairing adhesion during double molding with a polycarbonate resin molded product. And heat shock resistance can be improved.

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

As the (F) epoxy compound, one having one or more epoxy groups in one molecule and an epoxy equivalent of 500 g/eq or more and 2000 g/eq or less is used. When the epoxy equivalent is in this range, the effect of improving alkali resistance can be obtained without causing problems such as thickening and foreign matters 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 more preferably 1200 or less, 1100 or less, 1000 or less in this order.

The (F) epoxy compound is not particularly limited as long as it has the above-mentioned 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. May be.

The polybutylene terephthalate resin composition according to the present embodiment is, depending on the purpose, the above-mentioned (A) polybutylene terephthalate resin, (B) polycarbonate resin, (C) olefin elastomer, and (D) silicone compound, ( Components other than the E) filler and the (F) epoxy compound may be optionally contained. Other components include antioxidants, stabilizers, molecular weight regulators, ultraviolet absorbers, antistatic agents, colorants, lubricants, release agents, crystallization accelerators, crystal nucleating agents, infrared absorbers, flame retardants. , Flame retardant aids, hydrolysis resistance improvers, fluidity improvers 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 for suppressing transesterification between (A) polybutylene terephthalate resin and (B) polycarbonate resin. It is preferable to add (a metal phosphate such as monocalcium 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, and 80% by mass or more based on 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 more excellent alkali resistance and adhesiveness in double molding with a polycarbonate molded article.

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

One aspect of the present invention relates to a double molded product that is molded by using the above polybutylene terephthalate resin composition and 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 contact at least a part of a pre-molded polycarbonate resin composition molded article. The double molded article has a portion containing the above polybutylene terephthalate resin composition and a portion containing the polycarbonate resin composition, and a portion containing the polybutylene terephthalate resin composition and a portion containing the polycarbonate resin composition, Are touching at least in part. 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 is omitted here.
The polycarbonate resin composition contains a polycarbonate resin as a main component. Examples of the polycarbonate resin include polymers obtained by the reaction of a dihydroxy compound and 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 (B) polycarbonate resin.
The polycarbonate resin may have the same composition as the (B) polycarbonate resin or a different composition. The viscosity average molecular weight and melt viscosity (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 elastomer, if necessary, and further includes an antioxidant, a stabilizer, a molecular weight modifier, an ultraviolet absorber, an antistatic agent, a colorant, a lubricant, and a release agent. You may contain additives, such as a mold agent, a crystallization accelerator, a crystal nucleating agent, an infrared absorber, a flame retardant, a flame retardant auxiliary, a hydrolysis resistance improver, and a fluidity improver. Examples of the inorganic filler, elastomer and other additives include the same inorganic fillers, elastomers 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 this embodiment is not particularly limited, and a known method can be adopted. For example, a polybutylene terephthalate resin composition is injection-molded on a polycarbonate molded article obtained by injection-molding the polycarbonate resin composition in advance (polycarbonate molded article) placed in a mold cavity. A molded product can be obtained. Here, as the polycarbonate resin composition used for the polycarbonate molded article, 50% by mass or more of the resin component in the entire composition is a polycarbonate resin. The proportion 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. It is particularly preferable that the amount is not less than 95%, and most preferable that the amount is 95% by mass or more.

The double-molded product according to the present embodiment may be an insert-molded product obtained by injection molding 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 method for producing the insert-molded product is not particularly limited. For example, a molded product (polycarbonate molded product) obtained by previously injection-molding a polycarbonate resin composition 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 The polybutylene terephthalate resin composition can be injection-molded on the member to obtain a double molded product.
Further, when a polycarbonate molded product is injection-molded, an insert member made of a metal and/or an inorganic solid is placed in a mold, and a polycarbonate resin is injection-molded on the insert member to obtain a polycarbonate molded product having the insert member. It is also possible to obtain a double molded product by injection-molding the polybutylene terephthalate resin composition after the polycarbonate molded product having the insert member is placed in the mold cavity after the preparation.
In addition to the alkali resistance and the adhesion between the polycarbonate molded article and the molded article according to the present embodiment, the molded article is excellent in heat shock resistance, so that the molded article is a double molded article (or insert molded article) used as a component in contact with an alkaline solution. Can be suitably applied as. “Contacting with an alkaline solution” includes not only a state of being in constant contact with an alkaline solution but also a state of being in temporary contact with an alkaline solution. Examples of the alkaline solution include a detergent, a bleaching agent, a snow melting agent and the like. Applications of the double-molded article include, for example, automobile parts, electric appliance parts, and water parts.

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

[Examples 1 to 6, Comparative Examples 1 to 16]
After mixing the components shown in Table 1 in the proportions (parts by mass) shown in the same table, using a twin-screw extruder (TEX44αII manufactured by Japan Steel Works), melt-kneading at a cylinder temperature of 270° C. and extruding the polybutylene terephthalate resin. A pellet of the composition was obtained.

Details of each component used in Examples and Comparative Examples are shown below.
-PBT resin: manufactured by Wintech Polymer Co., Ltd. Polybutylene terephthalate resin with intrinsic viscosity (IV) = 0.85 dL/g-PC resin 1: Polycarbonate resin with melt viscosity 0.42 kPa-s (viscosity average molecular weight 22500)-PC Resin 2: Polycarbonate resin having melt viscosity of 0.29 kPa·s (viscosity average molecular weight 19500)
-PC resin 3: Polycarbonate resin having 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 (Rohm and Haas Japan, Paraloid EXL2311)
Elastomer 3: Acrylic core-shell polymer (Rohm and Haas Japan Co., Paraloid EXL2314)
-Silicone compound 1: dimethylpolysiloxane having a kinematic viscosity of 60,000 cSt at 25°C-Silicone compound 2: dimethylpolysiloxane having a kinematic viscosity of 5000 cSt at 25°C-Silicone compound 3: dimethylpolysiloxane having 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 Co., Ltd. Epicoat JER1004K
-Stabilizer: Taihei Chemical Industry Co., Ltd. monocalcium phosphate-Antioxidant: BASF Japan Co., Ltd. Irganox1010
Colorant (carbon black): Raven UV Ultra manufactured by Colombian Carbon Japan Co., Ltd.

<Evaluation>
(1) Alkali resistance The obtained polybutylene terephthalate resin composition pellets 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 flat plate-shaped molded piece having a weld portion was prepared. Next, this molded piece was cut 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 to prepare a test piece. The test piece was fixed to a jig in a flexed state so that a bending strain of 1.0% was always applied to the weld portion. In this state, the jig was immersed in a 10 mass% sodium hydroxide aqueous solution and allowed to stand at an ambient temperature of 23° C., and it was observed whether or not cracks were generated in the test piece after the immersion for 60 hours. The evaluation was performed using three test pieces for each of the pellets of each of the examples and comparative examples, and it was excellent when no crack was generated in any of the three test pieces, and only one of the three test pieces was evaluated. The case where cracks were generated was evaluated as good, and the case where cracks were generated in all three test pieces was evaluated as defective. The results are shown in Table 1.

(2) Bonding strength of double molded product 1 (double moldability 1)
As a primary molded product, the above-mentioned PC resin 2 was dried at 120° C. for 5 hours, and then at a cylinder temperature of 280° C., a mold temperature of 100° C., a holding pressure of 98 MPa, an Izod test piece (63.5 mm×63.5 mm×63.5 mm× 12.7 mm x 6.4 mm) was injection-molded and left standing at 23°C and 50% RH for 24 hours to prepare a cavity for a bending test piece molding die (127 mm x 127 mm) conforming to ASTM D790. (12.7 mm x 6.4 mm), and was installed so as to contact one end surface of the mold. Then, the polybutylene terephthalate resin composition of each example dried at 140° C. for 3 hours was treated with a cylinder temperature of 270° C., a mold temperature of 70° C., a holding pressure of 78 MPa, and the rest of the cavity of the bending test piece molding mold. By injection molding in a space (63.5 mm×12.7 mm×6.4 mm), and one end face of the molded product of PC resin 2 and one end face of the molded product made of the polybutylene terephthalate resin composition of each example. 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 carried out according to ISO527-1 and 2, the bonding strength was measured, and double moldability 1 was evaluated. As an evaluation standard, a case where the bonding strength was 20 MPa or more was excellent, a case where the bonding strength was 10 MPa or more and less than 20 MPa was good, and a case where the bonding strength was less than 10 MPa was poor. The results are shown in Table 1.

(3) Bonding strength 2 of double molded product (double moldability 2)
In the evaluation of the double moldability 1, the end surface (12.7 mm×6.4 mm) of the primary molded product made of the PC resin 2 to be joined with the polybutylene terephthalate resin composition was treated as a smooth mold transfer surface. Although double-molded in the state, four grooves each having a length of 12.7 mm, a width of 0.8 mm, and a depth of 0.8 mm were formed on the end faces to be joined so as to form a stripe shape parallel to a side of 12.7 mm. This book was formed by cutting so that the distance between the grooves was 0.8 mm, and this was double-molded in a state where it was installed as a primary molded product in the mold cavity. When the polybutylene terephthalate resin composition enters the groove formed on the end face and is joined, the joint 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 joint strength of 30 MPa or more was evaluated as excellent and the joint strength of 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 have excellent alkali resistance and high joint strength when formed 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 article having excellent bonding strength in a double molded article with a polycarbonate resin molded article in addition to alkali resistance -It can be suitably used for a wide range of fields such as electronics, automobiles, general sundries, etc., especially for applications in contact with alkaline solutions.

Claims

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