JP5848556B2 - Polyester resin composition and molded body - Google Patents

Description

  The present invention relates to a polyester resin composition and a molded body. More specifically, the present invention is excellent in flame retardancy and color tone, excellent in electrical characteristics such as light discoloration resistance, heat discoloration resistance, tracking resistance, and the like. The present invention relates to a polyester resin composition excellent in metal corrosion resistance and mold stain resistance, and a molded body formed by molding the same.

  Thermoplastic polyester resins represented by polybutylene terephthalate and polyethylene terephthalate are excellent in mechanical strength, chemical resistance, electrical insulation, etc., and have excellent heat resistance, moldability, and recyclability. Therefore, it is widely used for electrical and electronic equipment parts, automobile parts, other electrical parts, machine parts and the like.

In the field of electrical and electronic equipment, flame retardancy is extremely important to ensure safety against fire, and it has excellent tracking resistance, which is one of the electrical characteristics, to ensure safety against ignition due to electrical loads. It is necessary to be.
And in recent years, electrical and electronic equipment parts and electrical parts have been made thinner and smaller due to the trend toward miniaturization of the equipment itself. As a result, the insulation distance is reduced, and the tracking resistance of these parts (molded products) is reduced. Requirement specifications are becoming more sophisticated. Since the insulating material is dried and charged by heat generated from the apparatus during energization, dust tends to adhere to the surface of the insulating material. For this reason, the parts formed from the insulating material tend to have dust on the surface when the equipment is stopped. The dust absorbs moisture in the air, and the absorbed moisture reduces the surface resistance of the material, causing leakage. The current increases. In general, electrical components are more or less exposed to such a situation, and the tracking resistance characteristics of insulating materials are regarded as important.
Electrical and electronic equipment components must meet the requirements of UL94 standard flame retardancy and comparative tracking index (CTI) of Underwriters Laboratories, USA, and V-0 at 0.75 mm thickness It is desirable that the above flame retardancy and CTI satisfy the PLC (Performance Level Category) 2 level (250 V ≦ CTI <400 V) or more.

  In order to make a thermoplastic polyester resin flame retardant, a halogen-based flame retardant or an inorganic flame retardant is usually blended, but these tend to deteriorate electrical characteristics such as tracking resistance of the thermoplastic polyester resin. .

For example, Patent Document 1 discloses a resin composition containing a thermoplastic polyester resin and an olefin-based copolymer composed of an α-olefin and a glycidyl ester of an α, β-unsaturated acid. It is described that a conventional flame retardant, fillers such as talc, kaolin and silica, and fibrous fillers such as glass fibers may be added as necessary. No. 2 describes a resin composition comprising polybutylene terephthalate, bromine-based flame retardant, antimony-based flame retardant aid, fluorinated ethylene-based polymer, polyolefin, metal silicate filler, and glass fiber.
Patent Document 3 discloses a resin composition comprising a thermoplastic polyester resin, compressed fine powder talc, and a halogenated benzyl (meth) acrylate flame retardant. If necessary, a fibrous reinforcing agent is added. It is described that it may be.
However, none of these resin compositions are always satisfactory in terms of flame retardancy, tracking resistance and mechanical strength.

  Furthermore, Patent Document 4 describes a resin composition in which a compressed fine powder talc and brominated polystyrene are blended with a thermoplastic polyester resin. However, although this resin composition achieves PLC2 of CTI, metal corrosion occurs on molds, etc., or when it is used as electrical and electronic equipment parts having metal contacts and terminals, There is a problem that the metal contacts and terminals are easily corroded by the gas, and the metal corrosion resistance is poor. Furthermore, it has a defect that the light discoloration resistance and heat discoloration resistance are poor.

JP-A-7-196859 JP-A-10-67925 JP-A-10-158486 JP 2000-109657 A

  The object of the present invention is a polyester resin excellent in flame retardancy and color tone, excellent in electrical properties such as light discoloration resistance, heat discoloration resistance and tracking resistance, and also excellent in metal corrosion resistance and mold stain resistance To provide materials.

The inventor of the present invention provides a polyester resin composition containing a specific amount of a brominated flame retardant in a thermoplastic polyester resin, wherein the amount of free bromine is a specific amount or less, and the yellow index of the resin composition is 23 or less. The inventors have found that the problems can be solved and have completed the present invention.
That is, according to this invention, the following polyester resin compositions and a molded object using the same are provided.

[1] A resin composition containing 3 to 60 parts by mass of a brominated flame retardant (B) with respect to 100 parts by mass of the thermoplastic polyester resin (A),
Brominated flame retardant (B) is a polymer of brominated styrene,
A polyester resin composition, wherein the content of free bromine in the resin composition is 800 ppm by mass or less, and the yellow index (YI) of the resin composition is 23 or less.
[2] The polyester resin composition as described in [1] above, wherein the chlorine content in the resin composition is 500 mass ppm or less.
[3] The polyester resin composition as described in [1] or [2] above, wherein the sulfur content in the resin composition is 250 ppm by mass or less.
[ 4 ] The polyester resin composition according to any one of [1] to [ 3 ], wherein the brominated flame retardant (B) has a mass average molecular weight (Mw) of 10,000 to 70,000. .
[ 5 ] The polyester resin composition according to any one of [1] to [ 4 ] above, wherein the main component of the thermoplastic polyester resin (A) is polybutylene terephthalate.
[ 6 ] A molded article obtained by molding the polyester resin composition according to any one of [1] to [ 5 ].
[7] molded article, molded article according to [6], characterized in that the electric and electronic equipment parts.
[ 8 ] The molded body according to the above [ 6 ] or [ 7 ], wherein the molded body is selected from the group consisting of a housing of a connector, a relay, a switch, and an electric / electronic device component.

The polyester resin composition of the present invention is excellent in flame retardancy and color tone, and is also excellent in electrical properties such as light discoloration resistance, heat discoloration resistance, tracking resistance, etc., mold contamination resistance, and metal corrosion resistance.
For this reason, the polyester resin composition of the present invention is preferably used as an insulating part for electrical and electronic equipment, for example, for housings, connectors, relays, switches, sensors, actuators, terminal switches, etc. of electronic and electrical equipment parts. Can do.

[1. Summary of the Invention]
The polyester resin composition of the present invention is a resin composition containing 3 to 60 parts by mass of a brominated flame retardant (B) with respect to 100 parts by mass of the thermoplastic polyester resin (A),
Brominated flame retardant (B) is a polymer of brominated styrene,
The amount of free bromine in the resin composition is 800 ppm by mass or less, and the yellow index (YI) of the resin composition is 23 or less.

Hereinafter, the contents of the present invention will be described in detail.
The description of each constituent element described below may be made based on typical embodiments and specific examples of the present invention, but the present invention is interpreted to be limited to such embodiments and specific examples. It is not a thing. In the present specification, “to” is used to mean that the numerical values described before and after it are used as the lower limit and the upper limit, and “ppm” means “mass ppm”.

[2. Thermoplastic polyester resin (A)]
The thermoplastic polyester resin (A) which is the main component of the polyester resin composition of the present invention is obtained by polycondensation of a dicarboxylic acid compound and a dihydroxy compound, polycondensation of an oxycarboxylic acid compound or polycondensation of these compounds. Polyester, which may be homopolyester or copolyester.

As the dicarboxylic acid compound constituting the thermoplastic polyester resin (A), an aromatic dicarboxylic acid or an ester-forming derivative thereof is preferably used.
Aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl-2, 2′-dicarboxylic acid, Biphenyl-3, 3'-dicarboxylic acid, biphenyl-4, 4'-dicarboxylic acid, diphenyl ether-4, 4'-dicarboxylic acid, diphenylmethane-4, 4'-dicarboxylic acid, diphenylsulfone-4, 4'-dicarboxylic acid , Diphenylisopropylidene-4,4′-dicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4′-dicarboxylic acid, anthracene-2,5-dicarboxylic acid, anthracene-2,6-dicarboxylic acid, p -Terphenylene-4,4'-dicarboxylic acid, pyridine-2,5-dicarboxylic acid, etc. Terephthalic acid can be preferably used.

These aromatic dicarboxylic acids may be used as a mixture of two or more. As is well known, these can be used in polycondensation reactions as ester-forming derivatives such as dimethyl esters in addition to free acids.
If the amount is small, together with these aromatic dicarboxylic acids, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid, sebacic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and 1 One or more alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid can be mixed and used.

Examples of the dihydroxy compound constituting the thermoplastic polyester resin (A) include ethylene glycol, propylene glycol, butanediol, hexylene glycol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol, and triethylene glycol. Examples thereof include aliphatic diols, alicyclic diols such as cyclohexane-1,4-dimethanol, and mixtures thereof. If the amount is small, one or more long-chain diols having a molecular weight of 400 to 6,000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, and the like may be copolymerized.
In addition, aromatic diols such as hydroquinone, resorcin, naphthalenediol, dihydroxydiphenyl ether, and 2,2-bis (4-hydroxyphenyl) propane can also be used.

  In addition to the above-mentioned bifunctional monomers, trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane are introduced to introduce a branched structure, and fatty acids are used for molecular weight control. A small amount of a monofunctional compound can be used in combination.

  As the thermoplastic polyester resin (A), usually, a resin mainly composed of polycondensation of a dicarboxylic acid and a diol, that is, a resin comprising 50% by mass, preferably 70% by mass or more of the entire resin, is composed of this polycondensate. The dicarboxylic acid is preferably an aromatic carboxylic acid, and the diol is preferably an aliphatic diol.

Of these, polyalkylene terephthalate, in which 95 mol% or more of the acidic component is terephthalic acid and 95 mass% or more of the alcohol component is an aliphatic diol, is preferred. Typical examples are polybutylene terephthalate and polyethylene terephthalate. These are preferably close to homopolyester, that is, 95% by mass or more of the total resin is composed of a terephthalic acid component and a 1.4-butanediol or ethylene glycol component.
In the polyester resin composition of the present invention, the main component is preferably polybutylene terephthalate.

  The intrinsic viscosity of the thermoplastic polyester resin (A) is preferably 0.5 to 2 dl / g. From the viewpoint of moldability and mechanical properties, those having an intrinsic viscosity in the range of 0.6 to 1.5 dl / g are preferred. If the intrinsic viscosity is lower than 0.5 dl / g, the resulting resin composition tends to have a low mechanical strength. On the other hand, if it is higher than 2 dl / g, the fluidity of the resin composition may deteriorate and the moldability may deteriorate. The intrinsic viscosity of the thermoplastic polyester resin is measured at 30 ° C. in a 1: 1 (mass ratio) mixed solvent of tetrachloroethane and phenol.

[3. Brominated flame retardant (B)]
As the brominated flame retardant (B) contained in the polyester resin composition of the present invention, any conventionally known brominated flame retardant used in thermoplastic polyester resins can be used. Examples of such brominated flame retardants include aromatic compounds. Specifically, for example, brominated epoxy compounds such as tetrabromobisphenol A epoxy oligomers, brominated benzyls such as pentabromobenzyl polyacrylate ( Brominated imide compounds such as (meth) acrylate, brominated polyphenylene ether, brominated polystyrene, N, N'-ethylenebis (tetrabromophthalimide) (EBTPI), brominated polycarbonate, brominated phenoxy resin, brominated bisphenol A, glycidyl Examples thereof include brominated bisphenol A. Of these, brominated benzyl (meth) acrylates such as poly (pentabromobenzyl acrylate), brominated epoxy compounds, brominated polystyrenes, and brominated imide compounds are preferred from the viewpoint of good thermal stability. ) Acrylate, brominated polystyrene, brominated polycarbonate and brominated imide compound are more preferable, brominated polystyrene, brominated polycarbonate and brominated imide compound are more preferable, and brominated polystyrene is particularly preferable.

  Brominated benzyl (meth) acrylate is a polymer obtained by polymerizing benzyl (meth) acrylate containing a bromine atom alone, copolymerizing two or more kinds, or copolymerizing with other vinyl monomers. The bromine atom is preferably added to a benzene ring, and the number of addition is preferably 1 to 5, more preferably 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. Examples of the benzyl methacrylate containing a bromine atom include methacrylates corresponding to the acrylates described above.

  Specific examples of other vinyl monomers used for copolymerization with benzyl (meth) acrylates containing bromine atoms include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and benzyl acrylate. Acrylic acid esters, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacrylic acid esters such as benzyl methacrylate, unsaturated carboxylic acids such as styrene, acrylonitrile, fumaric acid, maleic acid or anhydrides thereof, vinyl acetate And vinyl chloride.

  These are usually preferably used in an equimolar amount or less, particularly 0.5 times the molar amount or less with respect to benzyl (meth) acrylate containing a bromine atom.

  In addition, xylene diacrylate, xylene dimethacrylate, tetrabromoxylene diacrylate, tetrabromoxylene dimethacrylate, butadiene, isoprene, divinylbenzene, etc. can be used as vinyl monomers, and these usually contain bromine atoms. The benzyl acrylate or benzyl methacrylate can be used at a molar amount of 0.5 times or less.

  As brominated benzyl (meth) acrylate, pentabromobenzyl polyacrylate is preferred because of its high bromine content and high tracking resistance.

（式（１）中、ｔは１〜５の整数であり、ｎは繰り返し単位の数である。） The brominated polystyrene preferably includes brominated polystyrene containing a repeating unit represented by the following general formula (1).

(In formula (1), t is an integer of 1 to 5, and n is the number of repeating units.)

  In the general formula (1), the CH group to which brominated benzene is bonded may be substituted with a methyl group. The brominated polystyrene may be a copolymer obtained by copolymerizing another vinyl monomer. Examples of the vinyl monomer in this case include styrene, α-methylstyrene, acrylonitrile, methyl acrylate, butadiene, and vinyl acetate. Moreover, brominated polystyrene may be used as a single substance or a mixture of two or more different structures, and may contain units derived from styrene monomers having different numbers of bromines in a single molecular chain.

  Specific examples of brominated polystyrene include, for example, poly (4-bromostyrene), poly (2-bromostyrene), poly (3-bromostyrene), poly (2,4-dibromostyrene), poly (2,6 -Dibromostyrene), poly (2,5-dibromostyrene), poly (3,5-dibromostyrene), poly (2,4,6-tribromostyrene), poly (2,4,5-tribromostyrene) , Poly (2,3,5-tribromostyrene), poly (4-bromo-α-methylstyrene), poly (2,4-dibromo-α-methylstyrene), poly (2,5-dibromo-α- Methyl (styrene), poly (2,4,6-tribromo-α-methylstyrene), poly (2,4,5-tribromo-α-methylstyrene) and the like, and poly (2,4,6-tribromostyrene). And poly (2,4,5-tribromostyrene) and polydibromostyrene and polytribromostyrene containing an average of 2 to 3 bromine groups in the benzene ring are particularly preferably used.

Brominated polystyrene is usually produced by brominating polystyrene. For example, it is produced by reacting bromine or bromine chloride with polystyrene in a chlorinated hydrocarbon solvent (for example, methylene chloride, dichloroethane, etc.) in the presence of a Lewis basic acid catalyst.
On the other hand, brominated styrene monomers (for example, 2,4-dibromostyrene, 2,6-dibromostyrene, 2,5-dibromostyrene, 3,5-dibromostyrene, 2,4,6-tribromostyrene, 2 , 4,5-tribromostyrene, 2,3,5-tribromostyrene, etc.).
The brominated polystyrene in the present invention may be any of the above bromination reaction or polymerization method, but there is a problem of bromination reaction other than the aromatic ring and the content of free bromine (atom or compound). Less bromine polystyrene (atomic or compound) generated in the subsequent heating and molding process is preferred, and brominated polystyrene by polymerization is more preferred.

In the brominated polystyrene, the number n (average polymerization degree) of the repeating units in the general formula (1) is preferably 30 to 1,500, more preferably 150 to 1,000, particularly 300 to 800. Is preferred. If the average degree of polymerization is less than 30, blooming tends to occur. On the other hand, if it exceeds 1,500, poor dispersion tends to occur and the mechanical properties tend to deteriorate. The mass average molecular weight (Mw) of brominated polystyrene is preferably about 10,000 to 200,000, more preferably 10,000 to 100,000, and still more preferably 10,000 to 70,000. It is.
In particular, in the case of the brominated product of polystyrene described above, the mass average molecular weight (Mw) is preferably 50,000 to 70,000, and in the case of brominated polystyrene by a polymerization method, the mass average molecular weight (Mw) is 10 It is preferable that it is about 3,000-30,000. In addition, a mass average molecular weight (Mw) can be calculated | required as a value of standard polystyrene conversion by GPC measurement.

  The brominated polycarbonate is preferably a brominated polycarbonate obtained from brominated bisphenol A, particularly tetrabromobisphenol A. Examples of the terminal structure include a 4-t-butylphenyl group and a 2,4,6-tribromophenyl group, and those having a 2,4,6-tribromophenyl group in the terminal group structure are particularly preferable.

  The average number of carbonate repeating units in the brominated polycarbonate may be appropriately selected and determined, but is usually 2 to 30. If the average number of carbonate repeating units is small, the molecular weight of the polyester resin may be lowered during melting. On the other hand, if it is too large, the melt viscosity of the polycarbonate becomes high, causing a dispersion failure in the molded product, which may deteriorate the appearance of the molded product, particularly the glossiness. Therefore, the average number of repeating units is preferably 3 to 15, particularly 3 to 10.

  The brominated polycarbonate obtained from the brominated bisphenol A can be obtained, for example, by an ordinary method in which brominated bisphenol and phosgene are reacted. Examples of the end-capping agent include aromatic monohydroxy compounds, which may be substituted with a halogen or an organic group.

（式（２）中、ｉは１〜４の整数である。）
中でも、上記式（２）におけるｉが４である、Ｎ，Ｎ’−エチレンビス（テトラブロモフタルイミド）が好ましい。 As a brominated imide compound, Preferably, the compound shown by following General formula (2) is mentioned.

(In formula (2), i is an integer of 1 to 4.)
Among these, N, N′-ethylenebis (tetrabromophthalimide) in which i in the above formula (2) is 4 is preferable.

  The mass average molecular weight (Mw) of the brominated flame retardant (B) is preferably about 10,000 to 200,000, more preferably 10,000 to 100,000, still more preferably 10,000 to 70, 000. In addition, a mass average molecular weight (Mw) can be calculated | required as a value of standard polystyrene conversion by GPC measurement.

  The brominated flame retardant (B) preferably has a bromine concentration of 52 to 75% by mass, more preferably 56 to 70% by mass, and even more preferably 57 to 70% by mass. By setting the bromine concentration in such a range, it is easy to keep good flame retardancy.

  Further, the content of free bromine in the brominated flame retardant (B) is preferably 0.5% by mass or less, more preferably 0.45% by mass or less, and 0.4% by mass or less. More preferably it is. When the content of free bromine exceeds 0.5% by mass, the amount of free bromine in the resin composition finally obtained increases, and is desorbed when the resin composition is at a high temperature during processing or molding. In some cases, the heat discoloration resistance, color tone, and light discoloration resistance of the resin composition may be deteriorated, or metal corrosion or mold contamination of the mold may occur during molding. Also, removing the free bromine content up to 0% by mass requires purification so as not to be economical, so the lower limit of the content is usually 0.001% by mass and 0.005% by mass. %, And more preferably 0.01% by mass.

  Further, the chlorine content in the brominated flame retardant (B) is preferably 0.2% by mass or less, more preferably 0.15% by mass or less, and 0.08% by mass or less. More preferably, it is especially preferable that it is 0.03 mass% or less. If the chlorine content in the brominated flame retardant (B) exceeds 0.2% by mass, the chlorine content in the finally obtained resin composition will increase too much, resulting in tracking resistance, toughness, and metal corrosion resistance. And mold contamination resistance tend to deteriorate.

  Furthermore, the content of sulfur in the brominated flame retardant (B) is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, and 0.02% by mass or less. More preferably. When the sulfur content in the brominated flame retardant (B) exceeds 0.1% by mass, the sulfur content in the finally obtained resin composition becomes too large, and tracking resistance, metal corrosion resistance, There is a tendency for the mold-resistant contamination to deteriorate.

  The content of free bromine, chlorine and sulfur in the brominated flame retardant (B) can be measured by a combustion ion chromatography method. Specifically, the bromine flame retardant (B) was heated by using an automatic sample combustion apparatus of “AQF-100 type” manufactured by Mitsubishi Chemical Analytech Co., Ltd. in an argon atmosphere at 270 ° C. for 10 minutes, and generated bromine. The amount of chlorine and sulfur can be determined by quantitative determination using “ICS-90” manufactured by Nippon Dionex.

  Content of a brominated flame retardant (B) is 3-60 mass parts with respect to 100 mass parts of thermoplastic polyester resins (A). When the blending amount is less than 3 parts by mass, a sufficient flame retarding effect cannot be obtained, and when it exceeds 60 parts by mass, the mechanical strength is lowered. The preferable content of the brominated flame retardant (B) is 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, and particularly preferably 15 to 30 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). Part.

[4. Content of free bromine in resin composition]
In the present invention, the content of free bromine in the polyester resin composition needs to be 800 ppm by mass or less. Free bromine is considered to be derived from the brominated flame retardant (B) or the raw material for its production, but in what state and form the free bromine specified in the present invention was present in the resin composition. It is not limited.
It is considered that the free bromine contained in the brominated flame retardant (B) is desorbed when the temperature is high during the treatment or molding of the resin composition, and the content of free bromine in the resin composition is 800 If the mass exceeds ppm, the thermoplastic polyester resin (A) is adversely affected, the heat discoloration resistance, color tone and light discoloration resistance of the resin composition are deteriorated, and the metal corrosion resistance and mold contamination resistance are reduced. It is.
The upper limit with preferable this content is 700 mass ppm, More preferably, it is 650 mass ppm, More preferably, it is 600 mass ppm, Especially preferably, it is 480 mass ppm. Moreover, since removing the content up to 0 mass ppm requires purification so as not to be economical, the lower limit is usually 1 mass ppm, preferably 5 mass ppm, more Preferably it is 10 mass ppm.

In the polyester resin composition of the present invention, the chlorine content in the resin composition is preferably 500 ppm by mass or less. When the chlorine content in the resin composition exceeds 500 mass ppm, the tracking resistance, toughness, metal corrosion resistance, and mold contamination resistance tend to deteriorate. The upper limit with preferable content is 350 mass ppm, More preferably, it is 200 mass ppm, More preferably, it is 150 mass ppm, Most preferably, it is 100 mass ppm.
In addition, the chlorine content in the resin composition is not limited in what state / form the chlorine was present in the resin composition. Since chlorine is mixed from various environments such as raw materials, additives, catalysts, polymerization atmosphere, resin cooling water, etc., it is preferable to control the total amount of mixing to 500 ppm by mass or less.

Furthermore, in the polyester resin composition of the present invention, the sulfur content in the resin composition is preferably 250 mass ppm or less. When the sulfur content in the resin composition exceeds 250 ppm by mass, the tracking resistance, the metal corrosion resistance and the mold contamination resistance tend to deteriorate. The upper limit with preferable content is 200 mass ppm, More preferably, it is 150 mass ppm, More preferably, it is 100 ppm, Especially preferably, it is 50 mass ppm.
In addition, the sulfur content in the resin composition is not limited in what state and form sulfur is present in the resin composition. Since sulfur is mixed in from various environments such as raw materials, additives, catalysts, polymerization atmospheres, etc., it is preferable to control the total amount of mixing to 250 ppm by mass or less.

  The content of free bromine, chlorine and sulfur in the polyester resin composition can be measured by a combustion ion chromatography method. Specifically, using an automatic sample combustion apparatus of “AQF-100 type” manufactured by Mitsubishi Chemical Analytech Co., Ltd., the resin composition is heated under an argon atmosphere at 270 ° C. for 10 minutes, and the generated bromine, chlorine, The amount of sulfur can be determined by quantifying using “ICS-90” manufactured by Nippon Dionex.

[5. Resin Composition Yellow Index (YI)]
The polyester resin composition of the present invention is required to have a yellow index (YI) of 23 or less at a thickness of 3 mm. When YI exceeds 23, the color tone of the obtained molded article is poor, and the light discoloration resistance and metal corrosion resistance are reduced. YI is preferably 18 or less, more preferably 15 or less, still more preferably 13 or less, and particularly preferably 10 or less.

[6. Stabilizer (C)]
It is preferable that the polyester resin composition of the present invention further contains a stabilizer (C) in that it has effects of improving thermal stability and preventing deterioration of mechanical strength, transparency and hue. As the stabilizer, a phosphorus stabilizer and a phenol stabilizer are preferable.
In particular, when a phosphorus-based stabilizer is contained, the mutual compatibility between the thermoplastic polyester resin (A) and the brominated flame retardant (B) can be remarkably improved. Can exhibit excellent elongation.

  Examples of the phosphorus-based stabilizer include phosphorous acid, phosphoric acid, phosphite ester, and phosphate ester. Among them, organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds are preferable.

The organic phosphate compound is preferably the following general formula:
(R ¹ O) _3-n P (═O) OH _n (2)
(In Formula (2), R ¹ is an alkyl group or an aryl group, and may be the same or different. N represents an integer of 0 to 2.)
It is a compound represented by these. More preferably, R ¹ is a long-chain alkyl acid phosphate compound having 8 to 30 carbon atoms. Specific examples of the alkyl group having 8 to 30 carbon atoms include octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, A hexadecyl group, an octadecyl group, an eicosyl group, a triacontyl group, etc. are mentioned.

Examples of the long-chain alkyl acid phosphate include octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, lauryl acid phosphate, stearyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonyl phenyl cyclo acid phosphate Acid phosphate, phenoxyethyl acid phosphate, alkoxy polyethylene glycol acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl Le acid phosphate, di-2-ethylhexyl acid phosphate, dioctyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, and a bis-nonylphenyl acid phosphate, or the like.
Among these, octadecyl acid phosphate is preferable, and this is marketed under the trade name “ADEKA STAB AX-71” of ADEKA.

As the organic phosphite compound, preferably, the following general formula:
^{R 2 O-P (OR 3} ) (OR 4) ··· (3)
(In the formula (3), R ² , R ³ and R ⁴ are each a hydrogen atom, an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, and R ² , R ³ and R ⁴ are At least one of them is an aryl group having 6 to 30 carbon atoms.)
The compound represented by these is mentioned.

  Examples of the organic phosphite compound include triphenyl phosphite, tris (nonylphenyl) phosphite, dilauryl hydrogen phosphite, triethyl phosphite, tridecyl phosphite, tris (2-ethylhexyl) phosphite, and tris (tridecyl). ) Phosphite, tristearyl phosphite, diphenyl monodecyl phosphite, monophenyl didecyl phosphite, diphenyl mono (tridecyl) phosphite, tetraphenyldipropylene glycol diphosphite, tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite Hydrogenated bisphenol A phenol phosphite polymer, diphenyl hydrogen phosphite, 4,4′-butylidene-bis (3-methyl-6-t rt-butylphenyldi (tridecyl) phosphite), tetra (tridecyl) 4,4′-isopropylidenediphenyldiphosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, di Lauryl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tris (4-tert-butylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, hydrogenated bisphenol A pentaerythritol phosphite Phytopolymer, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite Phosphite, 2,2'-methylenebis (4,6-di -tert- butylphenyl) octyl phosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite and the like.

The organic phosphonite compound is preferably the following general formula:
R ⁵ -P (OR ⁶ ) (OR ⁷ ) (4)
(In the formula (4), R ⁵ , R ⁶ and R ⁷ are each a hydrogen atom, an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, and R ⁵ , R ⁶ and R ⁷ are At least one of them is an aryl group having 6 to 30 carbon atoms.)
The compound represented by these is mentioned.

  Examples of the organic phosphonite compound include tetrakis (2,4-di-iso-propylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-n-butylphenyl) -4,4′-biphenyl. Range phosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,4'-biphenylene diphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3'-biphenylene diphospho Knight, tetrakis (2,4-di-tert-butylphenyl) -3,3'-biphenylenediphosphonite, tetrakis (2,6-di-iso-propylphenyl) -4,4'-biphenylenediphosphonite, Tetrakis (2,6-di-n-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2, -Di-tert-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,3'-biphenylenediphosphonite, and tetrakis (2,6- And di-tert-butylphenyl) -3,3′-biphenylenediphosphonite.

One type of phosphorous stabilizer may be contained, or two or more types may be contained in any combination and ratio.
As described above, octadecyl acid phosphate that exhibits excellent compatibility and dramatically improves elongation and thin-wall toughness is particularly preferable as the phosphorus stabilizer.

  Examples of the phenol-based stabilizer include pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-tert-butyl-4) -Hydroxyphenyl) propionate, thiodiethylenebis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), pentaerythritol tetrakis (3- (3,5-di-neopentyl-4-hydroxyphenyl) ) Propionate) and the like. 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.

  Content of a stabilizer (C) is 0.001-1 mass part with respect to 100 mass parts of thermoplastic polyester resins (A). When the content of the stabilizer (C) is less than 0.001 part by mass, it is difficult to expect an improvement in the thermal stability and compatibility of the resin composition, and a decrease in molecular weight and a deterioration in hue are likely to occur. When it exceeds the mass part, it becomes an excessive amount, and there is a tendency that silver generation and hue deterioration are more likely to occur. The content of the phosphorus stabilizer (C) is more preferably 0.001 to 0.7 parts by mass, and still more preferably 0.005 to 0.5 parts by mass.

[7. Other flame retardants (D) and flame retardant aids (E)]
The polyester resin composition of the present invention can also contain a flame retardant (D) other than the brominated flame retardant (B).

  Examples of the phosphorus-based flame retardant include (di) phosphinic acid metal salts such as aluminum ethylphosphinate, aluminum diethylphosphinate, aluminum ethylmethylphosphinate, zinc diethylphosphinate, and melamine and phosphorus represented by melamine polyphosphate. Reaction products with acids, phosphate esters, phosphazenes, etc. are mentioned. Among them, phosphazenes such as metal salts of diethylphosphinic acid, melamine polyphosphate, cyclic phenoxyphosphazene, chain phenoxyphosphazene, and crosslinked phenoxyphosphazene are excellent in thermal stability. It is preferable from the point.

Furthermore, the polyester resin composition of the present invention preferably contains a flame retardant aid (E). Examples of the flame retardant aid (E) include copper oxide, magnesium oxide, zinc oxide, molybdenum oxide, zirconium oxide, tin oxide, iron oxide, titanium oxide, aluminum oxide, antimony compound, and zinc borate. Two or more species may be used in combination. Among these, an antimony compound and zinc borate are preferable from the viewpoint of more excellent flame retardancy.
Examples of the antimony compound include antimony trioxide (Sb ₂ O ₃ ), antimony pentoxide (Sb ₂ O ₅ ), and sodium antimonate. In particular, it is preferable to use antimony trioxide in combination from the synergistic effect with the brominated flame retardant (B).

  When the antimony compound is used in combination, the bromine atom derived from the brominated flame retardant in the polyester resin composition and the mass concentration of the antimony atom derived from the antimony compound are preferably 5 to 16% by mass in total. It is more preferable that it is 6-15 mass%. If it is less than 5% by mass, the flame retardancy tends to decrease, and if it exceeds 16% by mass, the mechanical strength and tracking resistance may decrease. The mass ratio (Br / Sb) of bromine atoms and antimony atoms is preferably 0.3 to 5, and more preferably 0.3 to 4.

  The content of the flame retardant aid (E) is preferably 0.5 to 20 parts by mass, more preferably 0.7 to 18 parts by mass, and still more preferably 100 parts by mass of the thermoplastic polyester resin (A). 1 to 15 parts by mass.

In the present invention, in particular, the antimony compound and zinc borate described above may be used in combination as the flame retardant aid (E). Zinc borate has the effect of improving the flame retardance as well as the antimony compound, and further improving the comparative tracking index (CTI) and improving the insulation.
The content when zinc borate is used is preferably 0.3 to 1 (mass ratio) of zinc borate with respect to the brominated flame retardant (B), and a ratio of 0.4 to 0.8. More preferably, it is used.

[8. Inorganic filler (F)]
The polyester resin composition of the present invention can contain an inorganic filler (F) to improve its mechanical properties. As the inorganic filler (F), any conventional filler can be used. Specific examples include fibrous inorganic fillers such as glass fibers, carbon fibers, and mineral fibers. Among these, glass fibers are preferably used. In the present invention, the inorganic filler (F) is preferably 100 parts by mass or less, more preferably 20 to 80 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A).

[9. Anti-dripping agent (G)]
It is also preferable for the polyester resin composition of the present invention to contain an anti-dripping agent (G). As the anti-dripping agent (G), polytetrafluoroethylene (PTFE) is preferable, has a fibril forming ability, easily disperses in the resin composition, and binds the resins to form a fibrous material. It is shown. As specific examples of polytetrafluoroethylene, for example, “Teflon (registered trademark) 6J” or “Teflon (registered trademark) 30J” marketed by Mitsui DuPont Fluorochemical Co., Ltd., Daikin Chemical Industries, Ltd. Examples of such products include “Polyflon”, which is commercially available, and “Fullon”, which is commercially available from Asahi Glass Co., Ltd.
The content ratio of the dripping inhibitor (G) is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). If the anti-dripping agent (G) is less than 0.1 parts by mass, the flame retardancy tends to be insufficient, and if it exceeds 20 parts by mass, the appearance tends to deteriorate. The content ratio of the anti-dripping agent (G) is more preferably 0.1 to 10 parts by mass, preferably 0.3 to 5 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). .

[10. Release agent (H)]
The polyester resin composition of the present invention preferably further contains a release agent (H). As the release agent (H), known release agents that are usually used for polyester resins can be used. Among them, polyolefin compounds and fatty acid ester compounds are particularly difficult in inhibiting metal film adhesion. And one or more mold release agents selected from silicone compounds.

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

  Examples of the fatty acid ester compounds include fatty acid esters such as glycerin fatty acid esters and sorbitan fatty acid esters, and partially saponified products thereof. Among them, the fatty acid ester compounds are composed of fatty acids having 11 to 28 carbon atoms, preferably 17 to 21 carbon atoms. Preferred are mono- or di-fatty acid esters. Specifically, glycerol monostearate, glycerol monobehenate, glycerol dibehenate, glycerol-12-hydroxy monostearate, sorbitan monobehenate, etc. are mentioned.

  Moreover, as a silicone type compound, the compound modified | denatured from points, such as compatibility with a polyester resin, is preferable. Examples of the modified silicone oil include silicone oil in which an organic group is introduced into the side chain of polysiloxane, silicone oil in which an organic group is introduced into both ends and / or one end of polysiloxane, and the like. Examples of the organic group to be introduced include an epoxy group, an amino group, a carboxyl group, a carbinol group, a methacryl group, a mercapto group, and a phenol group, and preferably an epoxy group. As the modified silicone oil, a silicone oil in which an epoxy group is introduced into the side chain of polysiloxane is particularly preferable.

  It is preferable that content of a mold release agent (H) is 0.05-2 mass parts with respect to 100 mass parts of thermoplastic polyester resins (A). If the amount is less than 0.05 parts by mass, the surface property tends to decrease due to defective mold release at the time of melt molding. On the other hand, if it exceeds 2 parts by mass, the kneading workability of the resin composition decreases, and molding is also performed. The surface of the product may be cloudy. The content of the release agent (H) is preferably 0.07 to 1.5 parts by mass, and more preferably 0.1 to 1.0 parts by mass.

[11. Other ingredients]
The polyester resin composition of the present invention may further contain various additives as long as the effects of the present invention are not impaired. Examples of such additives include ultraviolet absorbers, dyes and pigments, fluorescent whitening agents, antistatic agents, antifogging agents, lubricants, antiblocking agents, fluidity improvers, plasticizers, dispersants, antibacterial agents, and the like. It is done.

  Moreover, the polyester resin composition in this invention can contain thermoplastic resins other than a thermoplastic polyester resin (A) in the range which does not impair the effect of this invention. Specific examples of other thermoplastic resins include polyacetal resins, polyamide resins, polyphenylene oxide resins, polystyrene resins, polyphenylene sulfide ethylene resins, polysulfone resins, polyether sulfone resins, polyetherimide resins, polyether ketones. Examples thereof include resins and polyolefin resins.

[12. Method for producing resin composition]
As a manufacturing method of the polyester resin composition of this invention, it can carry out in accordance with the conventional method of resin composition preparation. Usually, the components and various additives added as desired are mixed together and then melt-kneaded in a single-screw or twin-screw extruder. Also, the resin composition of the present invention can be prepared by mixing each component in advance or by mixing only a part of the components in advance and supplying them to an extruder using a feeder and melt-kneading them. Further, a master batch is prepared by melting and kneading a part of a polyester resin and a part of other components, and then the remaining polyester resin and other ingredients are blended and melt kneaded. Good.
In addition, when using fibrous things, such as glass fiber, as an inorganic filler, it is also preferable to supply from the side feeder in the middle of the cylinder of an extruder.

  The heating temperature at the time of melt kneading can be appropriately selected from the range of usually 220 to 300 ° C. If the temperature is too high, decomposition gas is likely to be generated, which may cause opacity. Therefore, it is desirable to select a screw configuration in consideration of shear heat generation. In order to suppress decomposition during kneading or molding in the subsequent process, it is desirable to use an antioxidant or a heat stabilizer.

[13. Molded body]
The polyester resin composition of the present invention is usually formed into an arbitrary shape and used as a molded body. There is no restriction | limiting in the shape, pattern, color, dimension, etc. of this molded object, What is necessary is just to set arbitrarily according to the use of the molded object.
The manufacturing method of a molded object is not specifically limited, The molding method generally employ | adopted about the polyester resin composition can be employ | adopted arbitrarily. For example, injection molding method, ultra-high speed injection molding method, injection compression molding method, two-color molding method, hollow molding method such as gas assist, molding method using heat insulating mold, rapid heating mold were used. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermoforming method, rotational molding method, laminate molding method, press molding method, Examples thereof include a blow molding method.

The polyester resin composition of the present invention is a polyester resin material that has excellent electrical properties, flame retardancy, mechanical properties, and fluidity, and therefore can be widely used in applications that require thin walls or complex shapes. It is particularly suitable as an electrical device, an electronic device, or an insulating part thereof.
Insulating parts can be used in combination with metal contacts, copper plates, etc., for contact electrical and electronic equipment parts such as relays, switches, connectors, terminal switches, sensors, actuators, microswitches, microsensors and microactuators, and electrical and electronic equipment. It can be preferably used as a housing.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not construed as being limited to the following examples.
In the following description, “parts” means “parts by mass” based on mass standards unless otherwise specified.

In the following Examples and Comparative Examples, the components used are as shown in Table 1 below.

(Examples 1 to 3 , Comparative Examples 1 to 10 )
Each component described in Table 2 below is blended so as to have a blending ratio (parts by mass) described in Tables 2 and 3, and using a twin screw extruder (screw diameter 35 mm), barrel set temperature 250 ° C., rotation Extrusion was performed at several 200 rpm to produce pellets of the resin composition. The characteristics of the obtained pellets were evaluated for test pieces that were injection molded at a cylinder temperature of 255 ° C. using an injection molding machine (Nestal SG75-SYCAP-M3A, manufactured by Sumitomo Heavy Industries, Ltd.). The evaluation results are shown in Table 2. In molding, the resin composition was dried at 120 ° C. for 6 to 8 hours until immediately before the molding.

<Evaluation method>
Each evaluation method is as follows.
(1) Free bromine, chlorine and sulfur content in brominated flame retardant and resin composition:
Quantification was performed by combustion ion chromatography. Bromine flame retardant or polyester resin composition is heated by heating the brominated flame retardant or polyester resin composition under conditions of 270 ° C. and 10 minutes in an argon atmosphere using an automatic sample combustion device of “AQF-100 type” manufactured by Mitsubishi Chemical Analytech Co., Ltd. The amount of sulfur was measured using “ICS-90” manufactured by Nippon Dionex.

(2) Yellow index (YI):
The yellow index (YI) was measured using a spectroscopic color meter SE-2000 manufactured by Nippon Denshoku Industries Co., Ltd., using a test piece of 60 × 60 × 3 mm thickness. The larger the YI value, the more colored it is.

(3) Flame retardancy (UL94):
In accordance with the method of Subject 94 (UL94) of Underwriters Laboratories, flame retardancy was tested using five test pieces (thickness: 0.75 mm). Flame retardancy was classified into V-0, V-1, and V-2 according to the evaluation method described in UL94. V-0 has the highest flame retardancy.

(4) Insulation characteristics: (Applicable standard: UL746A, paragraph 23, tracking resistance test method conforms to ASTM D3638)
Using a test piece of a disc having a thickness of 3.0 mm and a diameter of 50φ, the tracking resistance test method defined in the test method UL946A item 23 was measured in accordance with ASTM D3638. An electrolytic solution (0.1% aqueous solution of ammonium chloride, resistivity 385 Ω · cm at 23 ° C.) is dropped from the nozzle of the device at intervals of 30 seconds, and a voltage of 600 V or less (25 V step) is applied between the platinum electrodes, and tracking is performed. The number of electrolyzed droplets until the occurrence of was measured, and the voltage at which the average value of 5 times was less than 50 droplets was determined. In addition, it means that tracking resistance is so favorable that a numerical value is high.
PLC (Performance Level Category) determination criteria are: PLC2 is 250V ≦ CTI <400V, PLC3 is 175V ≦ CTI <250V.

(5) Light discoloration resistance:
A test piece having a size of 5 × 5 cm and a thickness of 3 mm was cut out from a flat test piece having a size of 10 × 10 cm and a thickness of 3 mm, and a black panel was obtained using a xenon arc weather tester (wavelength 340 nm, irradiation energy 1200 kJ / m ² ). Irradiation was performed for 200 hours at a temperature of 63 ° C. and no rain. The color difference of the test piece before and after the test was measured by the following method.
Using a spectrocolorimetric color difference meter (“CM-3600d” manufactured by Konica Minolta), the color difference (ΔE ^* ) before and after the light resistance test was evaluated by the following equation.
ΔE ^* = ((ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ) ^1/2
It can be said that the smaller the ΔE ^* , the smaller the color change and the better the light discoloration resistance.

(6) Heat discoloration:
A test piece having a size of 5 × 5 cm and a thickness of 3 mm was cut out from a flat test piece having a size of 10 × 10 cm and a thickness of 3 mm, and was treated in a hot air oven at 150 ° C. for 300 hours. The color difference of the test piece before and after the test was measured by the same method as in (5) above.
It can be said that the smaller the ΔE ^* , the smaller the color change and the better the heat discoloration.

(7) Metal corrosion resistance:
A 1 cm square silver plate (manufactured by Niraco) was placed on the test piece for evaluating flame retardancy (3) and allowed to stand in a hot air oven at 150 ° C. The test piece and the silver plate were taken out after 200 hours and 400 hours, and the corrosion state of the silver plate was visually observed. “○” indicates that there is no corrosion, and “X” indicates that there is corrosion, discoloration, or gloss change. In addition, with respect to the thing of the evaluation result of "x", the component detected from a corrosion part was identified by SEM-EDX measurement.

(8) Resistant to mold contamination:
The test piece for (3) flammability test was injection-molded continuously for 100 shots, and the mold surface was stained after 100 shots. Injection molding was performed using an injection molding machine (“J75ED” manufactured by Nippon Steel Co., Ltd.) under the conditions of a cylinder temperature of 240 to 270 ° C., a mold temperature of 80 ° C., an injection speed of 10 mm / second, and a molding cycle of 35 seconds. In addition, “A” indicates that there is no contamination, “O” indicates that there is a slight amount of contamination but there is no problem with normal continuous molding, “Δ” indicates that there is contamination, and “×” indicates that the contamination is severe and cannot be continuously formed.
The above evaluation results are shown in Table 2 and Table 3 below.

  From Table 2 and Table 3, the following becomes clear. That is, it can be seen that the polyester resin composition of the present invention is excellent in all of flame retardancy, insulation, color tone, light discoloration resistance, heat discoloration resistance, metal corrosion resistance and mold contamination resistance. On the other hand, it can be seen that the resin composition of the comparative example has any of the above-mentioned characteristics that are not satisfactory and does not satisfy all the effects of the present invention.

  The polyester resin composition of the present invention is excellent in flame retardancy and color tone, and further excellent in electrical properties such as light discoloration resistance, heat discoloration resistance, tracking resistance, and metal corrosion resistance and mold contamination resistance. Also excellent. Therefore, the polyester resin composition of the present invention can be particularly suitably applied to thin molded parts in electrical and electronic equipment parts. Moreover, since it can be suitably applied to automobile parts, building material parts, etc., industrial applicability is very high.

Claims (7)

A resin composition containing 3 to 60 parts by mass of a brominated flame retardant (B) with respect to 100 parts by mass of a thermoplastic polyester resin (A) mainly composed of polybutylene terephthalate ,
Brominated flame retardant (B) is a polymer of brominated styrene,
A polyester resin composition, wherein the content of free bromine in the resin composition is 480 mass ppm or less, and the yellow index (YI) of the resin composition is 23 or less.   The polyester resin composition according to claim 1, wherein the chlorine content in the resin composition is 500 mass ppm or less.   3. The polyester resin composition according to claim 1, wherein a sulfur content in the resin composition is 250 ppm by mass or less.   The polyester resin composition according to any one of claims 1 to 3, wherein the brominated flame retardant (B) has a mass average molecular weight (Mw) of 10,000 to 70,000. The molded object formed by shape | molding the polyester resin composition of any one of Claims 1-4 . The molded body according to claim 5 , wherein the molded body is an electric / electronic equipment component. The molded body according to claim 5 or 6 , wherein the molded body is selected from the group consisting of a connector, a relay, a switch, and a housing for parts of electric and electronic equipment.