JP7411148B2 - Polybutylene terephthalate resin composition and molded article - Google Patents

Description

The present invention relates to a polybutylene terephthalate resin composition and a molded article, and more particularly to a polybutylene terephthalate resin composition and its molded article that have excellent impact resistance, toughness, flame retardancy, fluidity, surface appearance, and hydrolysis resistance. Regarding molded objects.

Polybutylene terephthalate resin has properties suitable for engineering plastics, such as excellent heat resistance, moldability, chemical resistance, and electrical insulation properties, so it is used in electrical and electronic parts, automobile parts, other electrical parts, mechanical parts, etc. It is suitably used for.

Because polybutylene terephthalate resin has excellent crystal properties, it has the problem of insufficient toughness, as represented by impact strength.In order to solve this problem, research on polymer alloys has been conducted for a long time. Various proposals have also been made regarding flame retardant formulations.
For example, Patent Document 1 discloses a flame-retardant polyester resin composition containing a polybutylene terephthalate resin, a polycarbonate resin, a halogen flame retardant, a flame retardant aid, and a transesterification inhibitor; discloses a flame-retardant polyester resin composition comprising a polybutylene terephthalate resin, a polycarbonate resin, an elastomer, a flame retardant, and a flame retardant aid. Further, Patent Document 3 discloses a polyester resin composition comprising a polyester resin, polystyrene rubber, and a flame retardant.

In addition, polybutylene terephthalate resin is easily hydrolyzed by water and steam at high temperatures, and in order to be used as an industrial material such as electrical parts, electronic parts, automobile parts, and mechanical parts, it must be subjected to general chemical and physical In addition to a good balance of properties, it is required to have excellent hydrolysis resistance.
In addition, in recent years, the physical properties required in the electrical and electronic equipment field have become increasingly sophisticated, and materials with excellent impact resistance, toughness, flame retardance, fluidity, surface appearance, and hydrolysis resistance are required. ing. Furthermore, there is a growing need for impact resistance in low temperature environments such as -30°C.

Japanese Patent Application Publication No. 2007-314664 Japanese Unexamined Patent Publication No. 6-100713 Japanese Patent Application Publication No. 2005-112994

The problem (object) of the present invention is to solve the above-mentioned problems and provide a polybutylene terephthalate resin composition and a molded product thereof that have excellent impact resistance, toughness, flame retardancy, fluidity, surface appearance, and hydrolysis resistance. Our goal is to provide the following.

As a result of extensive studies to solve the above problems, the present inventors have found that by blending a specific amount of a fluoropolymer-elastomer composite into an alloy made of polybutylene terephthalate resin and polycarbonate resin, impact resistance and It was discovered that toughness, flame retardancy, fluidity, surface appearance, and hydrolysis resistance are improved, and the present invention was achieved.
The present invention relates to the following polybutylene terephthalate resin composition and molded article.

[1] (A) polybutylene terephthalate resin and (B) polycarbonate resin, based on a total of 100 parts by mass of (A) and (B), 50 to 80 parts by mass of (A) and 20 to 50 parts by mass of (B). A polybutylene terephthalate resin composition containing 3 to 30 parts by mass of (C) a fluoropolymer-elastomer composite based on a total of 100 parts by mass of (A) and (B). thing.
[2] The polybutylene terephthalate resin composition according to the above [1], wherein the elastomer of the fluoropolymer-elastomer composite (C) is an acrylic elastomer.
[3] The above [1], wherein the acrylic elastomer does not contain an epoxy group-containing component or a component derived therefrom, or if it does, the content thereof is 0 to 10% by mass in component (C); or The polybutylene terephthalate resin composition according to [2].
[4] The polybutylene terephthalate resin composition according to [2] above, wherein the acrylic elastomer is a graft copolymer of an acrylic ester and a polyorganosiloxane.
[5] Any of the above [1] to [4], further containing a flame retardant (D) from 3 to 30 parts by mass based on a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) polycarbonate resin. A polybutylene terephthalate resin composition according to claim 1.
[6] The polybutylene terephthalate resin composition according to the above [5], wherein the flame retardant (D) is a brominated polycarbonate.
[7] The above [1] to [6] further contains titanium oxide (E) in an amount of 0.05 to 10 parts by mass based on a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) polycarbonate resin. The polybutylene terephthalate resin composition according to any one of the above.
[8] A molded article comprising the polybutylene terephthalate resin composition according to any one of [1] to [7] above.
[9] The molded article according to [8] above, which is a casing.

The polybutylene terephthalate resin composition of the present invention has extremely high Charpy impact values, including impact values at extremely low temperatures such as -30°C, and has excellent toughness, as well as excellent fluidity, surface appearance, and resistance. Hydrolyzable and flame retardant.

The content of the present invention will be explained in detail below. In addition, in this specification, "~" is used to include the numerical values described before and after it as a lower limit value and an upper limit value.

The polybutylene terephthalate resin composition of the present invention includes (A) polybutylene terephthalate resin and (B) polycarbonate resin, based on a total of 100 parts by mass of (A) and (B), and 50 to 80 parts by mass of (A). , (B), and further contains 3 to 30 parts by mass of (C) fluoropolymer-elastomer composite based on a total of 100 parts by mass of (A) and (B). Features.

[(A) Polybutylene terephthalate resin]
The polybutylene terephthalate resin composition of the present invention contains (A) a polybutylene terephthalate resin.
(A) Polybutylene terephthalate resin is a polyester resin having a structure in which terephthalic acid units and 1,4-butanediol units are ester-bonded, and in addition to polybutylene terephthalate resin (homopolymer), terephthalic acid units and 1,4-butanediol units are , 4-butanediol units, and a mixture of a homopolymer and the copolymer.

(A) The polybutylene terephthalate resin may contain dicarboxylic acid units other than terephthalic acid, and specific examples of other dicarboxylic acids include isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalene dicarboxylic acid, and -Naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, biphenyl-2,2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, bis(4,4'- Aromatic dicarboxylic acids such as (carboxyphenyl)methane, anthracene dicarboxylic acid, and 4,4'-diphenyl ether dicarboxylic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexane dicarboxylic acid and 4,4'-dicyclohexyl dicarboxylic acid; and aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, and dimer acid.

The diol unit may contain other diol units in addition to 1,4-butanediol, and specific examples of other diol units include aliphatic or alicyclic diols having 2 to 20 carbon atoms. , bisphenol derivatives, and the like. Specific examples include ethylene glycol, propylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, cyclohexanedimethanol, 4,4'-dicyclohexylhydroxymethane, 4,4 '-dicyclohexylhydroxypropane, ethylene oxide-added diol of bisphenol A, and the like. In addition to the bifunctional monomers mentioned above, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane can be used to introduce branched structures, and fatty acids and the like can be used to adjust the molecular weight. Small amounts of monofunctional compounds can also be used in combination.

As described above, the polybutylene terephthalate resin (A) is preferably a polybutylene terephthalate homopolymer obtained by polycondensing terephthalic acid and 1,4-butanediol. It may be a polybutylene terephthalate copolymer containing one or more dicarboxylic acids and/or one or more diols other than 1,4-butanediol as the diol unit, and (A) the polybutylene terephthalate resin is In the case of polybutylene terephthalate resin modified by polymerization, specific preferred copolymers include polyester ether resin copolymerized with polyalkylene glycols, particularly polytetramethylene glycol, and dimer acid copolymerized polybutylene terephthalate. resin, isophthalic acid copolymerized polybutylene terephthalate resin. Among these, it is preferable to use a polyester ether resin copolymerized with polytetramethylene glycol.
Note that these copolymers have a copolymerization amount of 1 mol % or more and less than 50 mol % of the total segment of the polybutylene terephthalate resin. Among these, the amount of copolymerization is preferably 2 mol% or more and less than 50 mol%, more preferably 3 to 40 mol%, particularly preferably 5 to 20 mol%. Such a copolymerization ratio tends to improve fluidity, toughness, and tracking resistance, which is preferable.

(A) The polybutylene terephthalate resin preferably has an intrinsic viscosity of 0.5 to 2 dl/g. If a polybutylene terephthalate resin material having an intrinsic viscosity lower than 0.5 dl/g is used, the resulting polybutylene terephthalate resin material tends to have low mechanical strength. Moreover, if it is higher than 2 dl/g, the fluidity of the polybutylene terephthalate resin material may deteriorate and the moldability may deteriorate. The intrinsic viscosity is more preferably 0.8 dl/g or more, and preferably 1.8 dl/g or less.
Note that the intrinsic viscosity is measured at 30° C. in a mixed solvent of tetrachloroethane and phenol at a ratio of 1:1 (mass ratio).

(A) The amount of terminal carboxyl groups in the polybutylene terephthalate resin may be selected and determined as appropriate, but is usually 60 eq/ton or less, preferably 50 eq/ton or less, and 30 eq/ton or less. It is even more preferable. If it exceeds 60 eq/ton, alkali resistance and hydrolysis resistance will decrease, and gas will be likely to be generated during melt molding of the resin composition. Although the lower limit of the amount of terminal carboxyl groups is not particularly determined, it is usually 10 eq/ton in consideration of productivity in producing polybutylene terephthalate resin.

In addition, the amount of terminal carboxyl groups of polybutylene terephthalate resin is a value measured by dissolving 0.5 g of polyalkylene terephthalate resin in 25 mL of benzyl alcohol and titrating using a 0.01 mol/l benzyl alcohol solution of sodium hydroxide. be. The amount of terminal carboxyl groups can be adjusted by any conventionally known method, such as adjusting polymerization conditions such as raw material charging ratio, polymerization temperature, and pressure reduction method during polymerization, or reacting with a terminal blocking agent. That's fine.

(A) Polybutylene terephthalate resin is produced by melt polymerizing a dicarboxylic acid component whose main component is terephthalic acid or an ester derivative thereof and a diol component whose main component is 1,4-butanediol in a batch or continuous manner. It can be manufactured using Further, after producing a low molecular weight polybutylene terectate resin by melt polymerization, the degree of polymerization (or molecular weight) can be increased to a desired value by further performing solid phase polymerization under a nitrogen stream or under reduced pressure.
(A) Polybutylene terephthalate resin is obtained by a manufacturing method in which a dicarboxylic acid component whose main component is terephthalic acid and a diol component whose main component is 1,4-butanediol are continuously melt-polycondensed. is preferred.

The catalyst used in carrying out the esterification reaction may be any conventionally known catalyst, and examples thereof include titanium compounds, tin compounds, magnesium compounds, calcium compounds, and the like. Particularly preferred among these are titanium compounds. Specific examples of the titanium compound as an esterification catalyst include titanium alcoholates such as tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate, and titanium phenolates such as tetraphenyl titanate.

[(B) Polycarbonate resin]
The polybutylene terephthalate resin composition of the present invention contains (A) a polybutylene terephthalate resin and (B) a polycarbonate resin.
Polycarbonate resins are optionally branched thermoplastic polymers or copolymers obtained by reacting dihydroxy compounds or small amounts of polyhydroxy compounds with phosgene or carbonic acid diesters. The method for producing polycarbonate resin is not particularly limited, and those produced by the conventionally known phosgene method (interfacial polymerization method) or melting method (ester exchange method) can be used.

The dihydroxy compound as a raw material is substantially free of bromine atoms, and is preferably an aromatic dihydroxy compound. Specifically, 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), tetramethylbisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4- Examples include dihydroxydiphenyl, and preferably bisphenol A. Further, it is also possible to use a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the above-mentioned aromatic dihydroxy compound.

Among the polycarbonate resins mentioned above, aromatic polycarbonate resins derived from 2,2-bis(4-hydroxyphenyl)propane, or 2,2-bis(4-hydroxyphenyl)propane and other aromatic dihydroxy An aromatic polycarbonate copolymer derived from the compound is preferred. Alternatively, a copolymer mainly composed of an aromatic polycarbonate resin, such as a copolymer with a polymer or oligomer having a siloxane structure, may be used. Furthermore, two or more of the above-mentioned polycarbonate resins may be used in combination.

To adjust the molecular weight of polycarbonate resins, monovalent aromatic hydroxy compounds may be used, such as m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, p-long chain Examples include alkyl-substituted phenols.

The viscosity average molecular weight (Mv) of the polycarbonate resin is preferably 15,000 or more, more preferably 20,000 or more, still more preferably 23,000 or more, particularly preferably 25,000 or more, most preferably more than 28,000. preferable. If a resin having a viscosity average molecular weight lower than 20,000 is used, the resulting resin composition tends to have low mechanical strength such as impact resistance. Moreover, Mv is preferably 60,000 or less, more preferably 40,000 or less, and even more preferably 35,000 or less. If it is higher than 60,000, the fluidity of the resin composition may become poor and moldability may deteriorate.

In the present invention, the viscosity average molecular weight (Mv) of the polycarbonate resin is determined by measuring the viscosity of a methylene chloride solution of the polycarbonate resin at 25°C using an Ubbelohde viscometer, and determining the intrinsic viscosity ([η]). The value calculated from the following Schnell's viscosity formula is shown.
[η]=1.23×10 ⁻⁴ Mv ^0.83

The method for producing polycarbonate resin is not particularly limited, and polycarbonate resin produced by either the phosgene method (interfacial polymerization method) or the melting method (ester exchange method) can be used. It is also preferable to use a polycarbonate resin produced by a melting method and subjected to a post-treatment to adjust the amount of terminal OH groups.

The content of (B) polycarbonate resin is 20 to 50 parts by mass, preferably 25 parts by mass, based on the total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) polycarbonate resin. As mentioned above, the amount is more preferably 30 parts by weight or more, preferably less than 50 parts by weight, more preferably 48 parts by weight or less, still more preferably 46 parts by weight or less, particularly preferably 45 parts by weight or less. If it is less than the above lower limit, the effect of improving the impact resistance and toughness of the polybutylene terephthalate resin composition of the present invention will be small, and furthermore, the dimensional stability will decrease. Moreover, when the above upper limit is exceeded, fluidity deteriorates and moldability deteriorates.
The content of (A) polybutylene terephthalate resin is 50 to 80 parts by mass, preferably 75 parts by mass or less, more preferably is 70 parts by mass or less, preferably more than 50 parts by mass, more preferably 52 parts by mass or more, still more preferably 54 parts by mass or more, particularly preferably 55 parts by mass or more.

[(C) Fluoropolymer-elastomer composite]
The polybutylene terephthalate resin composition of the present invention contains (C) a fluoropolymer-elastomer composite. (B) The fluoropolymer-elastomer composite contains a fluoropolymer and an elastomer, and its form is preferably a mixture or a grafted product of these, but the form is not limited.
In the present invention, by containing (C) a fluoropolymer-elastomer composite, the impact resistance of the resin composition can be improved.

The elastomer used in the (C) fluoropolymer-elastomer composite used in the present invention is preferably a graft copolymer obtained by graft copolymerizing a rubber component with a monomer component copolymerizable with the rubber component. The method for producing the graft copolymer may be any method such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization, and the copolymerization method may be single-stage grafting or multi-stage grafting.

The glass transition temperature of the rubber component is usually 0°C or lower, preferably -20°C or lower, and more preferably -30°C or lower. Specific examples of rubber components include polybutadiene rubber, polyisoprene rubber, polybutyl acrylate, poly(2-ethylhexyl acrylate), polyalkyl acrylate rubber such as butyl acrylate/2-ethylhexyl acrylate copolymer, and polyorganosiloxane rubber. Silicone rubber, butadiene-acrylic composite rubber, IPN (Interpenetrating Polymer Network) type composite rubber consisting of polyorganosiloxane rubber and polyalkyl acrylate rubber, styrene-butadiene rubber, ethylene-propylene rubber, ethylene-butene rubber, ethylene-octene rubber, etc. Examples include ethylene-α-olefin rubber, ethylene-acrylic rubber, and fluororubber. These may be used alone or in combination of two or more. Among these, polybutadiene rubber, polyalkyl acrylate rubber, polyorganosiloxane rubber, IPN type composite rubber consisting of polyorganosiloxane rubber and polyalkyl acrylate rubber, and styrene-butadiene rubber are preferred from the viewpoint of mechanical properties and surface appearance. .

Specific examples of monomer components that can be graft copolymerized with the rubber component include aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylic acid ester compounds, (meth)acrylic acid compounds, glycidyl (meth)acrylate, etc. Epoxy group-containing (meth)acrylic acid ester compounds; maleimide compounds such as maleimide, N-methylmaleimide, and N-phenylmaleimide; α,β-unsaturated carboxylic acid compounds such as maleic acid, phthalic acid, and itaconic acid, and their anhydrides (eg, maleic anhydride, etc.). These monomer components may be used alone or in combination of two or more. Among these, from the viewpoint of mechanical properties and surface appearance, aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylic acid ester compounds, and (meth)acrylic acid compounds are preferable, and (meth)acrylic acid esters are more preferable. It is a compound. Specific examples of (meth)acrylate compounds include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, etc. be able to.

The graft copolymer obtained by copolymerizing the rubber component is preferably a core/shell graft copolymer type from the viewpoint of impact resistance and surface appearance. Among them, at least one rubber component selected from polybutadiene-containing rubber, polybutyl acrylate-containing rubber, polyorganosiloxane rubber, and IPN type composite rubber consisting of polyorganosiloxane rubber and polyalkyl acrylate rubber is used as a core layer, and around the A core/shell type graft copolymer consisting of a shell layer formed by copolymerizing (meth)acrylic acid ester is particularly preferred. In the above-mentioned core/shell type graft copolymer, one containing a rubber component in an amount of 40% by mass or more is preferable, and one containing a rubber component in an amount of 60% by weight or more is more preferable. Moreover, it is preferable that (meth)acrylic acid is contained in an amount of 10% by mass or more. In addition, the core/shell type in the present invention does not necessarily have to have a clearly distinguishable core layer and shell layer, and is meant to broadly include compounds obtained by graft polymerizing a rubber component around a core portion. It is.

Preferred specific examples of these core/shell type graft copolymers include methyl methacrylate-butadiene-styrene copolymer (MBS), methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS), and methyl methacrylate-butadiene copolymer. combination (MB), methyl methacrylate-acrylic rubber copolymer (MA), methyl methacrylate-acrylic rubber-styrene copolymer (MAS), methyl methacrylate-acrylic-butadiene rubber copolymer, methyl methacrylate-acrylic-butadiene rubber- Examples include styrene copolymer, methyl methacrylate-(acrylic silicone IPN rubber) copolymer, and the like. Such rubbery polymers may be used alone or in combination of two or more.

(B) The elastomer of the fluoropolymer-elastomer composite is preferably an elastomer containing an acrylic component, and preferably an acrylic rubber polymer copolymerized with an acrylic component. Among these, an acrylic core/shell type acrylic elastomer in which both the core and shell are acrylic esters is preferred from the viewpoint of impact resistance.

The content of the acrylic component in the core/shell type graft copolymer is preferably 50 to 95% by mass, more preferably 60 to 90% by mass, and even more preferably 70 to 85% by mass. If the content of the acrylic component is less than 50% by mass, impact resistance tends to be poor, and if it exceeds 95% by mass, hydrolysis resistance tends to deteriorate, which is not preferable.

The acrylic elastomer preferably does not contain an epoxy group-containing component or a component derived therefrom, or if it does, the content thereof is preferably 0 to 10% by mass in component (C). In particular, it is preferable not to contain an epoxy group. By not containing an epoxy group, the acrylic elastomer is selectively positioned in the polycarbonate resin phase rather than the polybutylene terephthalate resin phase, and the polycarbonate resin phase becomes enlarged, which tends to improve impact strength, which is preferable. Further, when containing an epoxy group, glycidyl methacrylate is particularly preferred as the epoxy group-containing vinyl monomer.

In addition, as the elastomer for the fluoropolymer-elastomer composite (B), a graft copolymer of acrylic acid ester and polyorganosiloxane is preferable from the viewpoint of impact resistance at low temperatures such as -30°C, and in particular, butyl acrylate is used as the core. A core/shell type graft copolymer containing an acrylic component consisting of (meth)alkyl acrylate such as polyorganosiloxane and a shell composed of an acrylate component such as poly(meth)alkyl acrylate is also preferably used. can.

(C) As the fluoropolymer of the fluoropolymer-elastomer composite, a fluoroolefin resin is preferable. Fluoroolefin resin is usually a polymer or copolymer containing a fluoroethylene structure, and specific examples include difluoroethylene resin, tetrafluoroethylene resin, tetrafluoroethylene/hexafluoropropylene copolymer resin, etc. Among these, tetrafluoroethylene resin is preferred.
Furthermore, the fluoropolymer preferably has a fibril-forming ability, and specifically includes a fluoroolefin resin having a fibril-forming ability. By having fibril-forming ability, the dispersion can easily permeate widely into the resin composition, and the hydrolysis resistance can be further improved, and the impact resistance can also be improved.

Further, as the fluoropolymer, an organic polymer-coated fluoroolefin resin can also be suitably used. The organic polymer that coats the fluoroolefin resin is not particularly limited, and specific examples of monomers for producing such an organic polymer include aromatic vinyl monomers such as styrene. (meth)acrylic acid ester monomers such as methyl acrylate and methyl methacrylate; vinyl cyanide monomers such as acrylonitrile; α,β-unsaturated carboxylic acids such as maleic anhydride; N- Maleimide monomers such as phenylmaleimide; glycidyl group-containing monomers such as glycidyl methacrylate; vinyl carboxylate monomers such as vinyl acetate; olefin monomers such as ethylene and propylene; diene monomers such as butadiene. Examples include mercury, etc. In addition, these monomers can be used individually or in mixture of 2 or more types.

The fluoropolymer-elastomer composite (C) used in the present invention consists of the above-described fluoropolymer and elastomer. (B) Various methods can be adopted to produce the fluoropolymer-elastomer composite, but a fluoropolymer aqueous dispersion and an organic polymer aqueous dispersion (latex) are mixed and coagulated or spray-dried. or after emulsion polymerization of a monomer having an ethylenically unsaturated bond in a dispersion mixture of an aqueous fluoropolymer dispersion and an aqueous organic polymer dispersion (latex). Preferred examples include a method of manufacturing by powdering by coagulation or spray drying.

(C) The content of the fluoropolymer in the fluoropolymer-elastomer composite is preferably 0.1 to 90% by mass, more preferably 0.1 to 50% by mass, and even more preferably 0.5 to 30% by mass. %, particularly preferably from 0.8 to 25% by weight, most preferably from 1.0 to 20% by weight.

The content of the (C) fluoropolymer-elastomer composite in the polybutylene terephthalate resin composition of the present invention is 3 to 30 parts by mass based on a total of 100 parts by mass of the (A) polybutylene terephthalate resin and (B) polycarbonate resin. It is. When the content is within this range, impact resistance, toughness, hydrolysis resistance, and retention heat stability can be made excellent. The content is preferably 5 parts by mass or more, more preferably 7 parts by mass or more, even more preferably 9 parts by mass or more, and preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass. It is as follows.

[Flame retardant (D)]
The polybutylene terephthalate resin composition of the present invention preferably contains a flame retardant (D).
As the flame retardant, known flame retardants for plastics can be used. Specifically, halogen-based flame retardants, phosphorus-based flame retardants (melamine polyphosphate, etc.), nitrogen-based flame retardants (melamine cyanurate, etc.), metal It is a hydroxide (such as magnesium hydroxide).
As the halogen flame retardant, bromine flame retardants are more preferred.

As the brominated flame retardant, any conventionally known brominated flame retardant used for thermoplastic resins can be used. Examples of such brominated flame retardants include aromatic compounds, such as polybrominated benzyl (meth)acrylates such as pentabromobenzyl polyacrylate, polybromophenylene ether, brominated polystyrene, Examples include brominated epoxy compounds such as epoxy oligomer of tetrabromobisphenol A, brominated imide compounds such as N,N'-ethylenebis(tetrabromophthalimide) (EBTPI), and brominated polycarbonates.

Among them, from the standpoint of good thermal stability, polybrominated benzyl (meth)acrylates such as pentabromobenzyl polyacrylate, brominated epoxy compounds such as epoxy oligomers of tetrabromobisphenol A, brominated polystyrene, and brominated polycarbonates are particularly preferred. Brominated polycarbonate is preferred from the viewpoint of impact resistance and flame retardancy.

Specifically, the brominated polycarbonate flame retardant is preferably a brominated polycarbonate obtained from brominated bisphenol A, particularly tetrabromobisphenol A, for example. Examples of the terminal structure include phenyl group, 4-t-butylphenyl group, 2,4,6-tribromophenyl group, etc. Especially those having 2,4,6-tribromophenyl group in the terminal structure. is preferred.

The average number of carbonate repeating units in the brominated polycarbonate flame retardant may be selected and determined as appropriate, but is usually 2 to 30. If the average number of carbonate repeating units is small, the molecular weight of the polybutylene terephthalate resin (A) may decrease during melting. On the other hand, if it is too large, the melt viscosity of the polycarbonate resin (B) will increase, resulting in poor dispersion within the molded product, which may reduce the appearance of the molded product, especially the glossiness. Therefore, the average number of repeating units is preferably 3 to 15, particularly 3 to 10.

The molecular weight of the brominated polycarbonate flame retardant is arbitrary and may be selected and determined as appropriate, but the viscosity average molecular weight is preferably 1,000 to 20,000, particularly preferably 2,000 to 10,000. The viscosity average molecular weight of the brominated polycarbonate flame retardant can be determined in the same manner as the measurement of the viscosity average molecular weight of the polycarbonate resin (B).

The brominated polycarbonate flame retardant obtained from the above-mentioned brominated bisphenol A can be obtained, for example, by a conventional method of reacting brominated bisphenol and phosgene. Terminal capping agents include aromatic monohydroxy compounds, which may be substituted with halogen or organic groups.

Polybrominated benzyl (meth)acrylates include polymers obtained by polymerizing benzyl (meth)acrylates containing bromine atoms alone, copolymerizing two or more types, or copolymerizing them with other vinyl monomers. The bromine atom is preferably added to a benzene ring, and the number of bromine atoms added is preferably 1 to 5, particularly 4 to 5 per benzene ring.

Examples of the benzyl acrylate containing a bromine atom include pentabromobenzyl acrylate, tetrabromobenzyl acrylate, tribromobenzyl acrylate, and mixtures thereof. Furthermore, examples of the benzyl methacrylate containing a bromine atom include methacrylates corresponding to the above-mentioned acrylates.

Examples of other vinyl monomers used for copolymerization with benzyl (meth)acrylate containing a bromine atom include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and benzyl acrylate. Acrylic acid esters; Methacrylic acid esters such as methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and benzyl methacrylate; Unsaturated carboxylic acids or their anhydrides such as styrene, acrylonitrile, fumaric acid, and maleic acid; Vinyl acetate , vinyl chloride, etc.

These are usually used in an amount equal to or less than 0.5 times the molar amount of benzyl (meth)acrylate containing a bromine atom, preferably 0.5 times or less.

Furthermore, as the vinyl monomer, xylene diacrylate, xylene dimethacrylate, tetrabromoxylene diacrylate, tetrabromoxylene dimethacrylate, butadiene, isoprene, divinylbenzene, etc. can also be used, and these usually contain a bromine atom. It can be used in an amount of not more than 0.5 times the molar amount of benzyl acrylate or benzyl methacrylate.

As the polybrominated benzyl (meth)acrylate, pentabromobenzyl polyacrylate is preferred from the viewpoints of high bromine content and high electrical insulation properties (anti-tracking properties).

Specific examples of the brominated epoxy compound include bisphenol A-type brominated epoxy compounds represented by tetrabromobisphenol A epoxy compounds.

The molecular weight of the brominated epoxy compound is arbitrary and may be selected and determined as appropriate, but it is preferably 3,000 to 100,000 in mass average molecular weight (Mw), with higher molecular weights being more preferable; specifically, Mw The molecular weight is preferably 15,000 to 80,000, especially 18,000 to 78,000 (Mw), more preferably 20,000 to 75,000 (Mw), particularly 22,000 to 70,000, and even within this range, those with a high molecular weight are preferable.
The epoxy equivalent of the brominated epoxy compound is preferably 3,000 to 40,000 g/eq, particularly preferably 4,000 to 35,000 g/eq, and particularly preferably 10,000 to 30,000 g/eq.

Moreover, a brominated epoxy oligomer can also be used together as a brominated epoxy compound flame retardant. At this time, for example, by using about 0 to 50% by mass of an oligomer having a Mw of 5000 or less, flame retardancy, mold releasability, and fluidity can be adjusted as appropriate. The bromine atom content in the brominated epoxy compound is arbitrary, but in order to impart sufficient flame retardancy, it is usually 10% by mass or more, preferably 20% by mass or more, particularly 30% by mass or more; The upper limit is preferably 60% by mass, especially 55% by mass or less.

The content of the flame retardant is preferably 3 to 30 parts by mass, more preferably 7 parts by mass or more, and Preferably it is 10 parts by mass or more, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, particularly preferably 20 parts by mass or less. If the content of the flame retardant is too low, the flame retardancy of the resin composition used in the present invention will be insufficient, and if the content is too high, problems such as deterioration of mechanical properties and mold releasability and bleed-out of the flame retardant will occur. .

[Antimony compound]
It is also preferable that the polybutylene terephthalate resin composition of the present invention contains an antimony compound as a flame retardant auxiliary agent.
Preferred examples of the antimony compound include antimony trioxide (Sb ₂ O ₃ ), antimony pentoxide (Sb ₂ O ₅ ), and sodium antimonate. Among these, antimony trioxide is preferred from the viewpoint of impact resistance.

The antimony compound is preferably blended as a masterbatch with (A) polybutylene terephthalate resin. This makes it easier for the antimony compound to exist in the (A) polybutylene terephthalate resin phase, thereby suppressing the adverse effects on the (B) polycarbonate resin, and tending to suppress a decrease in impact resistance.
The content of the antimony compound in the masterbatch is preferably 20 to 90% by mass. When the antimony compound content is less than 20% by mass, the proportion of the antimony compound in the flame retardant masterbatch is small, and the effect of improving the flame retardancy of the polybutylene terephthalate resin in which it is blended is small. On the other hand, if the antimony compound exceeds 90% by mass, the dispersibility of the antimony compound tends to decrease, and if this is blended into polybutylene terephthalate resin, the flame retardancy of the resin composition will become unstable, and the flame retardant master batch Workability during production is also significantly reduced. For example, when producing using an extruder, problems such as unstable strands and easy breakage tend to occur, which is undesirable.
The content of the antimony compound in the masterbatch is preferably 30 to 85% by mass, more preferably 40 to 80% by mass, and still more preferably 50 to 75% by mass.

The content of the antimony compound is preferably 1 to 15 parts by mass, more preferably 2 parts by mass or more, and even more preferably 2 parts by mass, based on a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) polycarbonate resin. .5 parts by weight or more, more preferably 10 parts by weight or less, still more preferably 7 parts by weight or less, especially 6 parts by weight or less, particularly preferably 5 parts by weight or less. If it is below the above lower limit, flame retardancy tends to decrease, and if it exceeds the above upper limit, the crystallization temperature decreases, deteriorating mold release properties, or decreasing mechanical properties such as impact resistance.

[Pigment]
It is also preferable that the polybutylene terephthalate resin composition of the present invention further contains a pigment in order to improve colorability and weather resistance. Examples of pigments include black pigments such as inorganic pigments (carbon black, such as acetylene black, lamp black, thermal black, furnace black, channel black, Ketjen black, etc.), white pigments such as titanium oxide, iron oxide red, etc. Examples include red pigments, orange pigments such as molybdate orange, organic pigments (yellow pigments, orange pigments, red pigments, blue pigments, green pigments, etc.). Among these, carbon black is preferred from the viewpoint of colorability and weather resistance, and titanium oxide is preferably blended from the viewpoint of impact resistance, flame retardance, and hydrolysis resistance.
By containing titanium oxide, crystallization of the polybutylene terephthalate resin (A) is appropriately delayed, higher impact resistance can be achieved, and flame retardancy is further improved.

The titanium oxide used is not particularly limited in terms of manufacturing method, crystal form, average particle size, etc. There are two methods for producing titanium oxide: the sulfuric acid method and the chlorine method. However, titanium oxide produced by the sulfuric acid method tends to have poor whiteness in compositions to which it is added. To achieve this, those produced by the chlorine method are preferred.

Further, the crystal forms of titanium oxide include rutile type and anatase type, and from the viewpoint of light resistance, rutile type crystal form is preferable. The average particle diameter of titanium oxide is preferably 0.01 to 3 μm, more preferably 0.05 to 1 μm, even more preferably 0.1 to 0.7 μm, and particularly preferably 0.05 to 1 μm. It is 1 to 0.4 μm. If the average particle diameter is less than 0.01 μm, the workability during production of the resin composition is poor, and if it exceeds 3 μm, the surface of the molded product is likely to become rough and the mechanical strength of the molded product is likely to decrease. Note that two or more types of titanium oxide having different average particle diameters may be used in combination.

Titanium oxide is preferably surface-treated with an organosiloxane-based surface treatment agent.

The content of the pigment is preferably 0.05 to 10 parts by mass based on a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) polycarbonate resin. If it is less than 0.05 parts by mass, the desired color may not be obtained or the effect of improving weather resistance may not be sufficient, and if it exceeds 10 parts by mass, mechanical properties may deteriorate. The pigment content is more preferably 0.05 to 7 parts by weight, and even more preferably 0.1 to 5 parts by weight.
The preferred content of titanium oxide is 0.05 to 10 parts by mass, more preferably 0.05 to 7 parts by mass, based on 100 parts by mass of the total of (A) polybutylene terephthalate resin and (B) polycarbonate resin. More preferably, it is 0.1 to 5 parts by mass.

[Stabilizer]
It is preferable that the polybutylene terephthalate resin composition of the present invention contains a stabilizer, since this has the effect of improving thermal stability and preventing deterioration of mechanical strength, transparency, and hue. One type of stabilizer may be contained, or two or more types may be contained in any combination and ratio.

The content of the stabilizer is preferably 0.001 to 2 parts by mass based on a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) polycarbonate resin. If the content of the stabilizer is less than 0.001 part by mass, it is difficult to expect improvement in the thermal stability and compatibility of the resin composition, and a decrease in molecular weight and deterioration of hue during molding are likely to occur. If it exceeds the amount, there is a tendency that the amount becomes excessive and silver formation and hue deterioration are more likely to occur. The content of the stabilizer is more preferably 0.001 to 1.5 parts by weight, and even more preferably 0.005 to 1.0 parts by weight.

As the stabilizer, phosphorus stabilizers and phenol stabilizers are preferred. In particular, it is preferable to use both in combination because mechanical properties such as impact resistance tend to be good.

Examples of the phosphorus stabilizer include phosphorous acid, phosphoric acid, phosphorous acid ester, phosphoric acid ester, etc. Among them, organic phosphoric acid ester compounds are preferred.

The organic phosphate compound has a partial structure in which 1 to 3 alkoxy groups or aryloxy groups are bonded to a phosphorus atom. In addition, a substituent may be further bonded to these alkoxy groups and aryloxy groups. Preferably, an organic phosphoric acid ester compound represented by any of the following general formulas (1) to (5) is used. Two or more organic phosphate compounds may be used in combination.

In general formula (1), R ¹ to R ⁴ each independently represent an alkyl group or an aryl group. M represents an alkaline earth metal or zinc.

In general formula (2), R ⁵ represents an alkyl group or an aryl group, and M represents an alkaline earth metal or zinc.

In general formula (3), R ⁶ to R ¹¹ each independently represent an alkyl group or an aryl group. M' represents a metal atom that becomes a trivalent metal ion.

In general formula (4), R ¹² to R ¹⁴ each independently represent an alkyl group or an aryl group. M' represents a metal atom that becomes a trivalent metal ion, and the two M's may be the same or different.

In general formula (5), R ¹⁵ represents an alkyl group or an aryl group. n represents an integer from 0 to 2. Note that when n is 0, three R ^15s may be the same or different, and when n is 1, two R ^15s may be the same or different.

In the general formulas (1) to (5), R ¹ to R ¹⁵ are usually an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms. From the viewpoint of retention heat stability, chemical resistance, moist heat resistance, etc., an alkyl group having 2 to 25 carbon atoms is preferred, and most preferably an alkyl group having 6 to 23 carbon atoms. Examples of the alkyl group include octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, hexadecyl group, octadecyl group, and the like. Further, M in general formulas (1) and (2) is preferably zinc, and M' in general formulas (3) and (4) is preferably aluminum.

Preferred specific examples of the organic phosphoric acid ester compounds include bis(distearyl acid phosphate) zinc salt for the compound of general formula (1), monostearyl acid phosphate zinc salt for the compound of general formula (2), and zinc salt of general formula (3). ) as a compound of tris(distearyl acid phosphate) aluminum salt, as a compound of general formula (4), a salt of one monostearyl acid phosphate and two monostearyl acid phosphate aluminum salts, general formula (4) Examples of the compound (5) include monostearyl acid phosphate and distearyl acid phosphate. These may be used alone or as a mixture.

As an organic phosphate ester compound, it has a very high effect of suppressing transesterification, has good thermal stability during molding processing, and has excellent moldability, making it possible to set the temperature of the measuring section of an injection molding machine at a higher temperature. Bis(distearyl acid phosphate) zinc, which is a zinc salt of an organic phosphoric acid ester compound represented by the general formula (1), is used from the viewpoint of stable molding and excellent hydrolysis resistance and impact resistance. It is preferable to use a zinc salt of stearyl acid phosphate such as a monostearyl acid phosphate zinc salt which is a zinc salt of an organic phosphate compound represented by the general formula (2). Commercially available products include "JP-518Zn" manufactured by Johoku Kagaku Kogyo.

The content of the organic phosphoric acid ester compound is preferably 0.001 to 1 part by weight based on a total of 100 parts by weight of (A) polybutylene terephthalate resin and (B) polycarbonate resin. When the content is less than 0.001 parts by mass, it is difficult to expect improvement in the thermal stability and compatibility of the resin composition, and a decrease in molecular weight and deterioration of hue during molding are likely to occur, and when the content exceeds 1 part by mass, If the amount is excessive, silver formation and hue deterioration tend to occur more easily. The content of the organic phosphate compound is more preferably 0.01 to 0.8 parts by mass, still more preferably 0.05 to 0.7 parts by mass, and particularly preferably 0.1 to 0.5 parts by mass. Department.

Examples of the phenolic stabilizer include pentaerythritol tetrakis (3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), octadecyl-3-(3,5-di-tert-butyl-4 -hydroxyphenyl)propionate, thiodiethylene bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), pentaerythritol tetrakis(3-(3,5-di-neopentyl-4-hydroxyphenyl) ) propionate), etc. Among these, pentaerythritol tetrakis (3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate is preferred.

The content of the phenolic stabilizer is preferably 0.001 to 1 part by mass based on a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) polycarbonate resin. When the content is less than 0.001 parts by mass, it is difficult to expect improvement in the thermal stability and compatibility of the resin composition, and a decrease in molecular weight and deterioration of hue during molding are likely to occur, and when the content exceeds 1 part by mass, If the amount is excessive, silver formation and hue deterioration tend to occur more easily. The content of the phenolic stabilizer is more preferably 0.001 to 0.7 parts by mass, and still more preferably 0.005 to 0.5 parts by mass.

[Release agent]
The polybutylene terephthalate resin composition of the present invention preferably contains a mold release agent. As the mold release agent, known mold release agents commonly used for polyester resins can be used, but among them, polyolefin compounds and fatty acid ester compounds are preferable because of their good alkali resistance.In particular, polyolefin compounds and fatty acid ester compounds are preferred. Compounds are preferred.

Examples of the polyolefin compound include compounds selected from paraffin wax and polyethylene wax, and among them, those having a weight average molecular weight of 700 to 10,000, more preferably 900 to 8,000.

Examples of fatty acid ester compounds include fatty acid esters such as saturated or unsaturated monovalent or divalent aliphatic carboxylic acid esters, glycerin fatty acid esters, sorbitan fatty acid esters, and partially saponified products thereof. Among these, mono- or di-fatty acid esters composed of a fatty acid having 11 to 28 carbon atoms, preferably 17 to 21 carbon atoms, and alcohol are preferred.

Examples of fatty acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melisic acid, tetraliacontanoic acid, montanic acid, adipic acid, azelaic acid, etc. It will be done. Furthermore, the fatty acid may be alicyclic.

Alcohols include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, monohydric or polyhydric saturated alcohols having 30 or less carbon atoms are preferred, and aliphatic saturated monohydric or polyhydric alcohols having 30 or less carbon atoms are more preferred. Here, aliphatic also includes alicyclic compounds.
Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, and the like. can be mentioned.

Note that the above ester compound may contain an aliphatic carboxylic acid and/or an alcohol as an impurity, or may be a mixture of a plurality of compounds.

Specific examples of fatty acid ester compounds include glycerin monostearate, glycerin monobehenate, glycerin dibehenate, glycerin-12-hydroxy monostearate, sorbitan monobehenate, pentaerythritol monostearate, and pentaerythritol distear. ester, stearyl stearate, ethylene glycol montanate, and the like.

The content of the mold release agent is preferably 0.1 to 3 parts by mass, but 0.2 to 2.5 parts by mass, based on a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) polycarbonate resin. It is more preferably 0.5 to 2 parts by weight, and even more preferably 0.5 to 2 parts by weight. If it is less than 0.1 part by mass, the surface properties tend to decrease due to poor mold release during melt molding, while if it exceeds 3 parts by mass, the kneading workability of the resin composition tends to decrease, and the molded product The appearance is likely to deteriorate.

[Other ingredients]
The polybutylene terephthalate resin composition of the present invention may also contain other resin additives other than those described above, if necessary, within a range that does not impede the effects of the present invention. Other resin additives include reinforcing fillers, anti-dripping agents, ultraviolet absorbers, weathering stabilizers, lubricants, catalyst deactivators, antistatic agents, blowing agents, plasticizers, crystal nucleating agents, crystallization promoters, etc. can be mentioned.

The polybutylene terephthalate resin composition of the present invention may contain other thermoplastic resins, thermosetting resins, etc. other than the above-mentioned essential component resins, if necessary, within a range that does not impede the effects of the present invention. be able to. Other thermoplastic resins include polyamide resin, polyacetal resin, polyphenylene oxide resin, polyphenylene sulfide resin, liquid crystal polyester resin, acrylic resin, etc., and thermosetting resins include phenol resin, melamine resin, silicone resin, Examples include epoxy resin. These may be one type or two or more types.

However, when containing other resins other than the above-mentioned essential component resins, the content is preferably 40 parts by mass or less based on a total of 100 parts by mass of the polybutylene terephthalate resin and (B) polycarbonate resin. , more preferably 30 parts by mass or less, further preferably 20 parts by mass or less, most preferably 10 parts by mass or less, particularly 5 parts by mass or less, and most preferably 2 parts by mass or less.

The method for producing the polybutylene terephthalate resin composition is not limited to a specific method, but includes (A) polybutylene terephthalate resin, (B) polycarbonate resin, and (C) fluoropolymer-elastomer composite, and the necessary An example of this method is to mix other components according to the composition, and then melt and knead the mixture.

The melting/kneading method includes, for example, uniformly mixing the above-mentioned essential components and other components blended as necessary using a Henschel mixer, ribbon blender, V-type blender, tumbler, etc. Examples include a method of melting and kneading using a kneading extruder, roll, Banbury mixer, Laboplast Mill (Brabender), and the like. If necessary, other components such as reinforcing fillers can also be fed from a side feeder of the kneading extruder. The temperature and kneading time during melting and kneading can be selected depending on the type of components constituting the resin component, the ratio of the components, the type of melting and kneading machine, etc., but the temperature during melting and kneading is 200 to 300. A range of 0.degree. C. is preferred. If the temperature exceeds 300°C, thermal deterioration of each component becomes a problem, and the physical properties of the molded article may deteriorate or the appearance may deteriorate.

The method for producing the desired molded article from the polybutylene terephthalate resin composition of the present invention is not particularly limited, and may be a molding method conventionally employed for thermoplastic resins, such as an injection molding method or an insert molding method. , a blow molding method, an extrusion molding method, a compression molding method, etc., among which injection molding method is preferable.

The molded product can be used as electrical/electronic parts, automobile parts and other electrical parts, mechanical parts, parts of home appliances such as cooking utensils, etc., for example, electric vehicle charger connectors, battery capacitor holders, battery capacitor casings, or electrical parts. Can be suitably used for car charging stand casings, electronic and electrical equipment parts casings, connectors, relays, switches, sensors, actuators, terminal switches, rice cooker related parts, grill cooking equipment parts, etc., especially for electric vehicle charging. It can be suitably used as a device connector, a battery capacitor holder, a battery capacitor casing, or an electric vehicle charging stand casing.
The shape, size, thickness, etc. of these molded bodies are arbitrary.

Hereinafter, the present invention will be explained in more detail based on Examples and Comparative Examples, but the present invention should not be interpreted as being limited to the following examples.
The raw material components used in the Examples and Comparative Examples are shown in Table 1 below.

The elastomer (CX1) in Table 1 above was produced according to Production Example 1 below, and the fluoropolymer-elastomer composites (C1 to C5) were produced according to Production Examples 2 to 6 below.

(Production Example 1) Production of Acrylic Elastomer (CX1) 99 parts by mass of 2-ethylhexyl acrylate and 1 part by mass of allyl methacrylate were mixed to obtain 100 parts by mass of a (meth)acrylate monomer mixture. 100 parts by mass of the above (meth)acrylate monomer mixture was added to 300 parts by mass of distilled water in which 1 part by mass of dipotassium alkenyl succinate was dissolved, and after preliminarily stirring at 10,000 rpm with a homogenizer, 300 kg/ml was added with a homogenizer. Emulsification and dispersion were performed at a pressure of cm ² to obtain a (meth)acrylate emulsion. This mixed solution was transferred to a separable flask equipped with a condenser and stirring blades, heated with nitrogen purging and stirring, and when the temperature reached 70°C, 1 part by mass of potassium persulfate dissolved in a small amount of water was added. The mixture was left at 70° C. for 5 hours to complete polymerization and obtain a latex (ALx-1) of acrylic rubber (A-1).
The polymerization rate of the latex (ALx-1) of the obtained acrylic rubber (A-1) was 98.5%, and the average particle diameter was 0.19 μm. Further, this latex was coagulated and dried with ethanol to obtain a solid, which was extracted with toluene at 90° C. for 12 hours, and the gel content was measured and found to be 91.4% by mass.

Collect 120 parts by mass of the latex (ALx-1) of the above acrylic rubber (A-1), put it in a separable flask equipped with a stirrer, add 205 parts by mass of distilled water, replace it with nitrogen, and heat it to 50°C. The temperature was raised, a mixed solution of 53.9 parts by mass of n-butyl acrylate, 1.1 parts by mass of allyl methacrylate and 0.22 parts by mass of tert-butyl hydroperoxide was charged and stirred for 30 minutes. A-1) latex (ALx-1) particles were infiltrated. Next, a mixture of 0.002 parts by mass of ferrous sulfate, 0.006 parts by mass of ethylenediaminetetraacetic acid disodium salt, 0.26 parts by mass of Rongalit and 5 parts by mass of distilled water was charged to start radical polymerization, and then the internal temperature was lowered. The polymerization was completed by holding at 70° C. for 2 hours to obtain a latex (ABLx-1) of polyalkyl (meth)acrylate rubber (AB-1). A portion of this latex was sampled and the average particle diameter of the polyalkyl (meth)acrylate rubber was measured and found to be 0.24 μm. Further, this latex was dried to obtain a solid substance, extracted with toluene at 90°C for 12 hours, and the gel content was measured and found to be 97.3% by mass.

(GMA denaturation)
A mixed solution of 0.06 parts by mass of tert-butyl hydroperoxide, 12 parts by mass of methyl methacrylate, and 3 parts by mass of glycidyl methacrylate (GMA) was added dropwise to this polyalkyl (meth)acrylate rubber latex at 70°C for 15 minutes. The mixture was then held at 70°C for 4 hours to complete graft polymerization to polyalkyl (meth)acrylate rubber. The polymerization rate of methyl methacrylate was 96.4%.
The obtained GMA-modified graft copolymer latex was dropped into 200 parts by mass of hot water containing 8% by mass of calcium acetate, coagulated, separated, washed, and then dried at 75°C for 16 hours to form a powdered acrylic elastomer (CX1). ) was obtained in an amount of 98.9 parts by mass.

(Production Example 2) Production of fluoropolymer-elastomer composite (C1) The GMA-modified graft copolymer latex obtained in Production Example 1 was added with a polytetrafluoroethylene aqueous dispersion (manufactured by AGC, "Fluon AD939E") 4 GMA-modified acrylic elastomer (fluoropolymer-elastomer composite C1) containing 2.5% by mass of powdered fluoropolymer was prepared in the same manner as in Production Example 1 except that .17 parts by mass was added and mixed in the stirring frame. 100.9 parts by mass were obtained.

(Production Example 3) Production of fluoropolymer-elastomer composite (C2) 2.08 parts by mass of a polytetrafluoroethylene aqueous dispersion ("Fluon AD939E") was added to the GMA-modified graft copolymer latex obtained in Production Example 1. 99.8 mass of GMA-modified acrylic elastomer (fluoropolymer-elastomer composite C2) containing 1.3 mass% of powdered fluoropolymer was prepared in the same manner as in Production Example 1 except for adding and mixing in a stirring frame. I got it.

(Production Example 4) Production of fluoropolymer-elastomer composite (C3) Production Example 2 except that the monomer component added dropwise to the polyalkyl (meth)acrylate rubber latex (ABLx-1) was 15 parts by mass of methyl methacrylate. In the same manner as above, 101.0 parts by mass of a GMA unmodified acrylic elastomer (fluoropolymer-elastomer composite C3) containing 2.5% by mass of powdered fluoropolymer was obtained.

(Production Example 5) Production of fluoropolymer-elastomer composite (C4) Latex containing 100 parts by mass of methyl methacrylate/butyl acrylate/dimethylsiloxane copolymer with Si content of 9.5% by mass and number average particle diameter of 200 nm. A polytetrafluoroethylene aqueous dispersion "Fluon AD939E" manufactured by AGC Corporation containing 2.5 parts by mass of polytetrafluoroethylene was mixed with stirring, and the mixed latex was dropped into 200 parts of hot water containing 8% by mass of calcium acetate. After coagulation, separation and washing, the mixture was dried at 75° C. for 16 hours to obtain a powdered fluoropolymer-elastomer composite (C4).

(Production Example 6) Production of fluoropolymer-elastomer composite (C5) Latex containing 100 parts by mass of methyl methacrylate/butyl acrylate/dimethylsiloxane copolymer with Si content of 10.1% by mass and number average particle diameter of 200 nm. A polytetrafluoroethylene aqueous dispersion "Fluon AD939E" manufactured by AGC Corporation containing 2.5 parts by mass of polytetrafluoroethylene was mixed with stirring, and the mixed latex was dropped into 200 parts of hot water containing 8% by mass of calcium acetate. The mixture was coagulated, separated, washed, and then dried at 75° C. for 16 hours to obtain a powdered fluoropolymer-elastomer composite (C5).

[Examples 1 to 7 and Comparative Examples 1 to 4]
<Production of polybutylene terephthalate resin composition>
The components listed in Table 1 are blended in the proportions (all parts by mass) shown in Table 2 below, and the blend is carried out using a 30 mm bent type twin screw extruder (manufactured by Japan Steel Works, twin screw extruder TEX30α). ) at a barrel temperature of 270°C, extruded into strands, and pelletized using a strand cutter to obtain pellets of a polybutylene terephthalate resin composition.

<Measurement evaluation method>
Measurement and evaluation of various physical properties and performances in Examples and Comparative Examples were carried out by the following methods.

(a) Impact resistance Notched Charpy impact strength (unit: kJ/m ² ):
After drying the obtained pellets at 120°C for 6 hours, they were molded using an injection molding machine "NEX80-9E" manufactured by Nissei Jushi Kogyo Co., Ltd. under the conditions of a cylinder temperature of 250°C and a mold temperature of 80°C for Charpy impact strength measurement. An ISO test piece was molded, and the notched Charpy impact strength was measured at a room temperature of 23°C and a low temperature of -30°C in accordance with ISO179.

(b) Flammability UL94 (1.5mmt):
The obtained pellets were molded into combustion test pieces of 12.5 mm x 125 mm x 1.5 mm thick using an injection molding machine (NEX80 manufactured by Nissei Jushi Kogyo Co., Ltd.) at a cylinder temperature of 250°C and a mold temperature of 80°C. was injection molded.
Flame retardancy was evaluated as follows.
According to the method of Subject 94 (UL94) of Underwriters Laboratories, the flammability was tested using the five flammability test pieces (thickness 1.5 mm) obtained above, and the results were as follows: V-0, V-1, Classified as V-2 and non-conforming.

(c) Liquidity:
(c-1) MVR (unit: cm ³ /10min):
The MVR (melt volume rate) of the pellets of the obtained polybutylene terephthalate resin composition was measured at a temperature of 250° C. and a load of 5 kgf in accordance with JIS K7210.
(c-2) ISO test piece forming peak pressure (unit: MPa):
For the Charpy impact strength measurement described above, the molding peak pressure was measured when the ISO test piece was injection molded.

(d) Surface appearance evaluation:
Using an injection molding machine "NEX80-9E" manufactured by Nissei Jushi Kogyo Co., Ltd., a flat plate of 100 mm long x 100 mm wide x 3 mm thick was molded at a cylinder temperature of 250°C and a mold temperature of 80°C, and the surface appearance was visually evaluated. It was divided as follows.
A: Good B: Slightly bad C: Significantly bad

(e) Hydrolysis resistance evaluation:
Using an injection molding machine "NEX80-9E" manufactured by Nissei Jushi Kogyo Co., Ltd., an ISO test piece was prepared at a cylinder temperature of 250°C and a mold temperature of 80°C, and a tensile test was conducted in accordance with ISO527.
Furthermore, the above-mentioned ISO test piece was subjected to moist heat treatment (PCT treatment) in saturated steam at a temperature of 121° C. and a pressure of 2 atm for 50 hours and 75 hours. The tensile strength and nominal tensile strain of the ISO test pieces before and after PCT treatment were measured in accordance with ISO527.
The tensile strength retention rate (unit: %) was determined from the following formula.
Tensile strength retention rate (%) = (Tensile strength after PCT/Tensile strength before PCT) x 100

(f) Comprehensive evaluation Based on the above results, a comprehensive evaluation was performed according to the following criteria.
Comprehensive evaluation A: All three of the following are satisfied. Comprehensive evaluation B: Two of the following three are satisfied. Comprehensive evaluation C: One or all of the following three are satisfied. Charpy impact strength at 23℃ 60 kJ/m ² or more Charpy impact strength at -30°C is 10 kJ/m ² or more Strength retention after 75 hours of PCT is 30% or more The results are shown in Tables 2 and 3 below.

The polybutylene terephthalate resin composition of the present invention has excellent impact resistance, toughness, fluidity, surface appearance, hydrolysis resistance, and flame retardancy, so it can be used in various electrical and electronic equipment parts, automobile parts, and other electrical equipment. For home appliances such as parts, machine parts, and cooking utensils, especially for electric vehicle charger connectors, battery capacitor holders, battery capacitor casings, and electric vehicle charging stand casings, these are particularly suitable for use at -30°C. It is also suitable for use in such low-temperature environments, and has very high industrial applicability.

Claims (9)

Contains (A) polybutylene terephthalate resin and (B) polycarbonate resin, based on a total of 100 parts by mass of (A) and (B), containing 50 to 80 parts by mass of (A) and 20 to 50 parts by mass of (B). A polybutylene terephthalate resin composition, further comprising (C) 3 to 30 parts by mass of a fluoropolymer-elastomer composite based on a total of 100 parts by mass of (A) and (B). The polybutylene terephthalate resin composition according to claim 1, wherein the elastomer of the fluoropolymer-elastomer composite (C) is an acrylic elastomer. The polybutylene according to claim 2 , wherein the acrylic elastomer does not contain an epoxy group-containing component or a component derived therefrom, or if it does, the content thereof is 0 to 10% by mass in component (C). Terephthalate resin composition. The polybutylene terephthalate resin composition according to claim 2, wherein the acrylic elastomer is a graft copolymer of an acrylic ester and a polyorganosiloxane. The polybutylene according to any one of claims 1 to 4, further comprising 3 to 30 parts by mass of a flame retardant (D) based on a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) polycarbonate resin. Terephthalate resin composition. The polybutylene terephthalate resin composition according to claim 5, wherein the flame retardant (D) is a brominated polycarbonate. The polybutylene terephthalate according to any one of claims 1 to 6, further comprising 0.05 to 10 parts by mass of titanium oxide based on a total of 100 parts by mass of (A) polybutylene terephthalate resin and (B) polycarbonate resin. Resin composition. A molded article comprising the polybutylene terephthalate resin composition according to any one of claims 1 to 7. The molded article according to claim 8, which is a casing.