JP5832334B2 - Polyester resin composition molded body - Google Patents

Description

  The present invention relates to a molded article of a polyester resin composition, and more specifically, has a unique morphology, excellent electrical properties such as flame retardancy and tracking resistance, and toughness (tensile strength, tensile elongation at break). In addition, the present invention relates to an excellent polyester resin composition molded body.

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 particular, in the field of electrical and electronic equipment, flame retardancy is extremely important to ensure safety against fires, and in order to ensure safety against ignition due to electrical loads, tracking resistance, which is one of the electrical characteristics, is important. It must be excellent.

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 bodies) 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.

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

  An object of this invention is to provide the molded object which consists of a polyester resin composition which is excellent also in electrical characteristics, such as a flame retardance and tracking resistance, and also excellent in mechanical strength, such as toughness.

In order to solve the above-mentioned problems, the present inventor has intensively studied the composition of various polyester resin compositions and the morphology of the molded product, and as a result, the morphology of the resin composition molded product has the effect of exhibiting flame retardancy. And the polyester resin composition containing a specific amount of a brominated flame retardant and an antimony compound, in a polyester resin composition containing a specific amount, found that a molded article having a specific morphology solves the above problems, The present invention has been completed.
That is, according to this invention, the following polyester resin composition molded objects are provided.

[1] From a polyester resin composition containing 3 to 60 parts by mass of a brominated flame retardant (B) and 0.5 to 20 parts by mass of an antimony compound (C) with respect to 100 parts by mass of the thermoplastic polyester resin (A). A molded body comprising
The thermoplastic polyester resin (A) has a continuous phase, the brominated flame retardant (B) forms a dispersed phase, and the antimony compound (C) has a morphology embedded in the brominated flame retardant (B) dispersed phase. A molded body of a polyester resin composition characterized by
[2] The polyester resin composition molded body according to the above [1], wherein the brominated flame retardant (B) dispersed phase embedding the antimony compound (C) is oriented in a beaded manner in the surface layer portion of the molded body.
[3] The polyester resin composition molded article according to the above [1] or [2], wherein the average diameter of the brominated flame retardant (B) dispersed phase in the molded article core is 5 μm or less.

[4] The molded polyester resin composition according to any one of [1] to [3], wherein the main component of the thermoplastic polyester resin (A) is polybutylene terephthalate.
[5] The polyester resin composition molded article according to any one of [1] to [4], wherein the brominated flame retardant (B) is pentabromobenzyl polyacrylate.
[6] The polyester resin composition molded article according to any one of [1] to [5], wherein the antimony compound (C) is antimony trioxide.
[7] Polyester according to any one of [1] to [6] above, wherein the tensile elongation at break (measured with a test piece (Type IV) of 1 mm thickness according to ASTM D638) is 10% or more. Resin composition molded body.
[8] The polyester resin composition molded article according to any one of [1] to [7], wherein a comparative tracking index (measured with a test piece having a thickness of 3 mm based on CTI, UL746A) is 250 V or more. .

The molded article of the polyester resin composition of the present invention exhibits a high flame retardant effect even when a flame retardant is blended in a small amount, and is excellent in mechanical properties such as electrical characteristics and toughness.
For this reason, the polyester resin composition molded body of the present invention is suitably used as an insulating part for electrical and electronic equipment, for example, a casing, a connector, a relay, a switch, a sensor, an actuator, a terminal switch, etc. can do.

4 is a scanning electron micrograph of the core part of the molded body obtained in Example 1. FIG. The photograph which mapped the scanning electron microscope image of the core part of the molded object obtained in Example 1 with the bromine atom. The photograph which mapped the scanning electron microscope image of the core part of the molded object obtained in Example 1 by the antimony atom. 4 is a scanning electron micrograph of the surface layer portion of the molded body obtained in Example 1. FIG. 4 is a scanning electron micrograph of the surface layer portion of the molded body obtained in Example 1. FIG. 4 is a scanning electron micrograph of the core part of the molded body obtained in Example 2. FIG. 4 is a scanning electron micrograph of the surface layer portion of the molded body obtained in Example 2. FIG. 4 is a scanning electron micrograph of the surface layer portion of the molded body obtained in Example 2. FIG. The scanning electron micrograph of the core part of the molded object obtained by the comparative example 1. FIG. The scanning electron micrograph of the surface layer part of the molded object obtained by the comparative example 1. FIG. The scanning electron micrograph of the surface layer part of the molded object obtained by the comparative example 1. FIG.

[1. Summary of the Invention]
The molded product of the polyester resin composition of the present invention is 3 to 60 parts by mass of the brominated flame retardant (B) and 0.5 to 20 parts by mass of the antimony compound (C) with respect to 100 parts by mass of the thermoplastic polyester resin (A). A molded article comprising a polyester resin composition containing a part, wherein the thermoplastic polyester resin (A) forms a continuous phase, the brominated flame retardant (B) forms a dispersed phase, and the antimony compound (C) is a brominated flame retardant. (B) It has the morphology embedded in the dispersed phase.
In the molded article of the polyester resin composition of the present invention, bromine and antimony are present in the vicinity by forming a morphology in which the antimony compound (C) is embedded in the brominated flame retardant (B) dispersed phase. As a result, the reaction rate is increased, a high flame retardant effect is exhibited even with a small amount of blending, and the antimony compound that causes tracking resistance and toughness deterioration is coated with a brominated flame retardant, so that electrical characteristics and toughness are achieved. It is presumed that it has excellent mechanical strength.

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 molded 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. The resulting polyester may be a homopolyester or a 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. The recited, 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. Aliphatic diols, alicyclic diols such as cyclohexane-1,4-dimethanol, etc., and mixtures thereof. If the amount is small, one or more kinds of 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 present invention, the polyester resin composition preferably has a main component of polybutylene terephthalate.
Moreover, what copolymerized polyalkylene glycols, such as isophthalic acid, a dimer acid, polytetramethylene glycol (PTMG), is preferable. These copolymers are those having a copolymerization amount of 1 mol% or more and less than 50 mol% in all segments of polybutylene terephthalate. Among them, the copolymerization amount is preferably 2 to 50 mol%, more preferably 3 to 40 mol%, and particularly preferably 5 to 30 mol%.

  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. When a material having an intrinsic viscosity lower than 0.5 dl / g is used, the resulting resin composition molded product 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)]
In the present invention, as the brominated flame retardant (B) contained in the polyester resin composition, any conventionally known brominated flame retardant used for thermoplastic polyester resins can be used. Examples of such brominated flame retardants include aromatic compounds, and specific examples include brominated epoxy compounds such as tetrabromobisphenol A epoxy oligomers and brominated benzyl poly (pentabenzylbenzyl 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 poly (meth) acrylates such as pentabromobenzyl polyacrylate, brominated epoxy compounds, brominated polystyrene, and brominated imide compounds are preferred from the viewpoint of good thermal stability, and brominated benzyl poly (meth) acrylates. Brominated polystyrene, brominated polycarbonate, and brominated imide compounds are more preferable, brominated polystyrene, brominated polycarbonate, and brominated imide compounds are more preferable, and in particular, bromine is particularly preferable because bromine-based flame retardants easily incorporate antimony compounds. Benzyl poly (meth) acrylate is preferred.

  Brominated benzyl poly (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.
Among these, pentabromobenzyl acrylate is particularly preferable.

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 poly (meth) acrylate, pentabromobenzyl polyacrylate is easy to stably form a specific morphology defined in the present invention, has a high bromine content, and has high tracking resistance. Is particularly preferable.

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 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 (atoms or compounds), Since there is little free bromine (atom or compound) generated during the subsequent heating or molding process, brominated polystyrene by a polymerization method is 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 body, which may deteriorate the appearance of the molded body, 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.

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 general 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 73% by mass, and further 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) measured by the combustion ion chromatography method is preferably 0.5% by mass or less, more preferably 0.45% by mass or less. Preferably, it is 0.4 mass% or less. 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. The resin composition molded article may deteriorate the heat discoloration, color tone, and light discoloration resistance of the resin composition, cause metal corrosion of the mold or mold contamination during molding, and further has a morphological structure defined in the present invention. It tends to be difficult to produce stably. 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 content of free chlorine in the brominated flame retardant (B) measured by the combustion ion chromatography method is preferably 0.3% by mass or less, more preferably 0.2% by mass or less. Preferably, it is 0.15% by mass or less, more preferably 0.08% by mass or less, and particularly preferably 0.03% by mass or less. If the chlorine content in the brominated flame retardant (B) exceeds 0.3% by mass, the chlorine content in the final resin composition will be too large, resulting in tracking resistance, toughness, and metal corrosion resistance. In addition, the mold property and mold resistance are liable to deteriorate, and the morphological structure defined in the present invention tends to be difficult to stably produce.

  Furthermore, the content of free sulfur in the brominated flame retardant (B) measured by the combustion ion chromatography method is preferably 0.1% by mass or less, more preferably 0.05% by mass or less. Preferably, it is 0.02 mass% or less. 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, Mold contamination resistance tends to be poor, and the morphological structure defined in the present invention tends to be difficult to produce stably.

  In addition, the measurement by the combustion ion chromatography method is specifically, using an automatic sample combustion apparatus of “AQF-100 type” manufactured by Mitsubishi Chemical Analytech Co., Ltd. under an argon atmosphere at 270 ° C. for 10 minutes. It can be determined by heating the brominated flame retardant (B) and quantifying the amount of bromine, chlorine and sulfur generated using “ICS-90” manufactured by Nippon Dionex Co., Ltd.

Content of the chlorine compound which is an impurity in a brominated flame retardant (B) is 0.3 mass% or less normally, Preferably it is 0.2 mass% or less, More preferably, it is 0.15 mass% or less, Furthermore, 0.00. It is preferable that the content is not more than 08% by mass, particularly not more than 0.03% by mass. By using such a brominated flame retardant, it becomes easy to stably form the morphological structure defined in the present invention.
Chlorine compounds that are impurities are chlorobenzene, chlorinated styrene, chlorinated bisphenol compounds, etc. For example, when brominated flame retardant (B) is brominated benzyl poly (meth) acrylate, it is chlorobenzene, and chlorobenzene is present in the above amount. Then, it becomes difficult to stably form the morphological structure of the present invention. The chlorine compound content can be quantified as a value in terms of decane by analyzing a gas generated by heating at 270 ° C. for 10 minutes by a gas chromatography method.

  The SP value of the brominated flame retardant (B) is preferably larger than that of the thermoplastic polyester resin (A). The brominated flame retardant (B) is preferably one or more larger than the SP value of the thermoplastic polyester resin (A), more preferably two or more, and particularly preferably 2.5 or more. By using such a brominated flame retardant (B), it becomes easy to stably form the morphological structure defined in the present invention. The SP value is R.D. F. Fedors, Polymer Engineering and Science, February, 1974, Vol. 14, no. 2, 147-154.

  Moreover, as a brominated flame retardant (B), what has a plasticizing effect is also preferable. Specifically, when blended with the thermoplastic polyester resin (A) and the antimony compound (C), the fluidity of the polyester resin composition is higher than the fluidity of the thermoplastic polyester resin (A). .

The brominated flame retardant (B) is present in the molded body in a dispersed state in the thermoplastic polyester resin (A) continuous phase, and the morphology in which the antimony compound (C) is embedded in the dispersed phase. It will have a structure.
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 content 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 8 to 40 parts by mass, and particularly preferably 10 to 30 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). Part.

The most preferable brominated flame retardant (B) is brominated benzyl poly (meth) acrylate, which can easily form the specific morphology described above, has a high bromine content, and has tracking resistance. Is preferable from the viewpoint of high.
As brominated benzyl poly (meth) acrylate, the content of chlorobenzene as an impurity is preferably 0.3% by mass or less, preferably 0.2% by mass or less, and 0.15% by mass or less. Is more preferably 0.08% by mass or less, and particularly preferably 0.03% by mass or less. By using a material having such a chlorobenzene content, the antimony compound (C) is more easily incorporated into the brominated benzyl poly (meth) acrylate, and the insulating properties, toughness, and flame retardancy tend to be improved, which is preferable. . Chlorobenzene can be quantified as a value in terms of decane by analyzing a gas generated by heating at 270 ° C. for 10 minutes by a gas chromatography method.

  The content of brominated benzyl poly (meth) acrylate is 3 to 60 parts by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A), and the preferable content is 100 parts by mass of the thermoplastic polyester resin (A). On the other hand, it is 5-50 mass parts, More preferably, it is 6-40 mass parts, More preferably, it is 7-30 mass parts, Especially 8-20 mass parts, Most preferably, it is 10-15 mass parts.

[4. Antimony compound (C)]
In the present invention, the polyester resin composition contains an antimony compound (C) which is a flame retardant aid. The antimony compound (C) is embedded in a brominated flame retardant (B) dispersed phase that is dispersed in the thermoplastic polyester resin (A) continuous phase of the molded body. .
Examples of the antimony compound (C) include antimony trioxide (Sb ₂ O ₃ ), antimony pentoxide (Sb ₂ O ₅ ), and sodium antimonate. In particular, antimony trioxide is preferable because it is easily incorporated into the brominated flame retardant (B).
Content of an antimony compound (C) is 0.5-20 mass parts with respect to 100 mass parts of thermoplastic polyester resins (A), More preferably, 0.7-18 mass parts, More preferably, 1- 15 parts by mass, in particular 2 to 10 parts by mass, most preferably 3 to 8 parts by mass.

  The mass concentration of the bromine atom derived from the brominated flame retardant (B) and the antimony atom derived from the antimony compound (C) in the polyester resin composition is usually 3 to 25% by mass, and 4 to 22% by mass. %, More preferably 5 to 16% by mass, and even more preferably 6 to 15% by mass. If it is less than 3% by mass, the flame retardancy tends to decrease, and if it exceeds 25% 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.

[5. Morphology of molded resin composition]
In the molded article of the polyester resin composition of the present invention, the thermoplastic polyester resin (A) forms a continuous phase, the brominated flame retardant (B) forms a dispersed phase, and the antimony compound (C) disperses the brominated flame retardant (B). It has a morphology embedded in the phase.
The morphology of the polyester resin composition molded body of the present invention can be measured by observing the cross section of the molded body with an optical microscope, SEM (scanning electron microscope), TEM (transmission electron microscope), and preferably scanning. Observed with a scanning electron microscope (SEM).
Specifically, using a SEM / EDX analyzer, the core portion of the cross section of the molded body (the portion excluding the surface layer portion having a depth of less than 0.2 mm, the central portion of the cross section and the cross section perpendicular to the resin composition flow direction). Are observed with a backscattered electron image with a magnification of 3,000 to 10,000 under an acceleration voltage of 20 kV.

  FIG. 1 shows an example of the morphology, and is a photograph (a magnification of 10,000 times) of a reflected electron image obtained by SEM / EDX analysis of the core portion of the molded body obtained in Example 1 of the present invention. . In FIG. 1, it is the thermoplastic polyester resin (A) that constitutes the continuous phase (matrix phase), and the round islands present in a light color are brominated flame retardants (B) (FIG. 1). 1 is a disperse phase of pentabromobenzyl polyacrylate), and in the round dispersion layer, a slightly whitened portion can be seen, which is an antimony compound (C) (antimony trioxide in FIG. 1) and bromine. It is confirmed that the flame retardant (B) is embedded in the dispersed phase.

Furthermore, that the antimony compound (C) is embedded in the brominated flame retardant (B) dispersed phase is that the image of the reflected electron image in the SEM / EDX mode described above is mapped with a bromine atom (Br) This can also be confirmed by comparing images mapped with antimony atoms (Sb).
2 is an image (magnification 10,000 times) obtained by mapping the image of FIG. 1 with bromine atoms (Br), and FIG. 3 is an image (magnification 10, magnification) obtained by mapping the image of FIG. 1 with antimony atoms (Sb). 000 times) and when both are observed together, antimony is dispersed in the region where bromine exists, and the antimony compound (C) is embedded in the brominated flame retardant (B) dispersed phase. I can confirm.

The average diameter of the dispersed phase in the core part of such a brominated flame retardant (B) is preferably 10 μm or less, more preferably 8 μm or less, further preferably 5 μm or less, and 4 μm or less. It is particularly preferred.
Further, the dispersion average diameter in the core portion of the antimony compound (C) embedded in the brominated flame retardant (B) dispersion layer is preferably 4 μm or less, more preferably 3 μm or less, particularly 2 μm or less. .

The particle size of the brominated flame retardant (B) dispersed phase and antimony compound (C) phase is such that the image obtained by the reflected electron image is enhanced in contrast, light and dark or both are adjusted. Can be read.
The particle diameters of the brominated flame retardant (B) dispersed phase and the antimony compound (C) phase are calculated by measuring 50 or more particle diameters of the dispersed phase and calculating the arithmetic average. When the dispersed phase is not circular, the major axis and minor axis are measured, and the average value is taken as the particle size of the particles.

The polyester resin composition molded body of the present invention preferably has a morphology in which the brominated flame retardant (B) dispersed phase embedding the antimony compound (C) is oriented in a bead shape in the surface layer portion of the molded body. Have Here, the surface layer refers to a portion having a depth of less than 0.2 mm from the surface of the molded body.
This characteristic surface layer morphology is shown, for example, in FIG. FIG. 4 is a photograph (magnification: 5,000 times) of a reflected electron image obtained by SEM / EDX analysis of the surface layer portion of the molded body obtained in Example 1 of the present invention.
In FIG. 4, the flow direction of the resin during molding is from the top to the bottom of FIG. 4, and it is the thermoplastic polyester resin (A) that constitutes the continuous phase (matrix phase). There is a dispersed phase of bromine-based flame retardant (B) that is white and stretches like a thread in the up and down flow direction of FIG. 4 (uses pentabromobenzyl polyacrylate in FIG. 4) and is oriented in a rosary shape. Is confirmed. Also, FIG. 5 is a photograph of the surface layer portion (magnification 10,000 times, resin flow direction from left to right in FIG. 5), and brominated flame retardant (B) dispersed phase (white portion) flows. It extends in a rosary shape in the direction, and an antimony compound (further white portion) is contained therein, and it can be seen that it is embedded in the brominated flame retardant (B).
Thus, the molded product of the present invention has a unique morphology.

[6. Preferred Control Method of Molded Body Morphology]
By having such a morphological structure, the molded article of the present invention is a molded article having excellent flame retardancy, electrical properties such as tracking resistance, and mechanical strength such as toughness.
The polyester resin composition used for the production of the resin composition molded article of the present invention is preferably produced by a melt kneading method using a melt kneader such as an extruder, but the raw materials of the polyester resin composition are mixed. Thus, it is difficult to stably form the morphological structure defined in the present invention simply by kneading, and it is recommended to knead by a special method. Below, the preferable manufacturing method for forming the morphological structure prescribed | regulated by this invention stably is demonstrated.

After mixing thermoplastic polyester resin (A), brominated flame retardant (B), and antimony compound (C) at a predetermined ratio, they are supplied to a single-screw or twin-screw extruder provided with a die nozzle, and then melt-kneaded. The resin composition is extruded from a die nozzle to form a strand, and then cut to produce pellets.
At this time, it is preferable to use a twin screw extruder as the melt kneader. Especially, it is preferable that L / D which is the ratio of the screw length L (mm) to the diameter D (mm) of the screw satisfies the relationship of 10 <(L / D) <100, and 15 <(L / D) It is more preferable to satisfy <70. When the ratio is 10 or less, the antimony compound (C) is hardly included in the brominated flame retardant (B). Conversely, even if the antimony compound (C) exceeds 100, the thermal degradation of the brominated flame retardant (B) is remarkable, and the antimony compound ( C) is not preferred because it tends to be difficult to be embedded.
The shape of the die nozzle is not particularly limited, but a circular nozzle having a diameter of 1 to 10 mm is preferable, and a circular nozzle having a diameter of 2 to 7 mm is more preferable in terms of pellet shape.

  Moreover, it is preferable that it is 200-300 degreeC, and, as for the melting temperature of the resin composition at the time of melt-kneading, it is more preferable that it is 210-295 degreeC. When the melting temperature is less than 200 ° C., melting is insufficient and unmelted gel is likely to occur frequently. On the other hand, when it exceeds 300 ° C., the resin composition is thermally deteriorated and easily colored.

  The screw rotation speed during melt kneading is preferably 30 to 1,000 rpm, and more preferably 50 to 800 rpm. If the screw speed is less than 30 rpm, the antimony compound tends to be less likely to be embedded in the brominated flame retardant, and if it exceeds 1,000 rpm, the antimony compound (C) aggregates and bromine is difficult to embed it. The domain of the flame retardant (B) may be enlarged, which is not preferable. The discharge rate is preferably 5 to 1,500 kg / hr, more preferably 10 to 1,300 kg / hr. When the discharge amount is less than 5 kg / hr, the antimony compound (C) is aggregated, and the brominated flame retardant (B) domain embedding the antimony compound (C) tends to be enlarged, and when it exceeds 1,500 kg / hr. The antimony compound tends to be less likely to be embedded in the brominated flame retardant.

Shear rate of the resin composition in the die nozzle is preferably 10～10,000Sec ^-1, more preferably 50～5,000Sec ^-1, more preferably from 70～1,000Sec ^-1 . When the shear rate exceeds 10,000Sec ^-1 antimony compound (C) does not easily embedded in the brominated flame retardant (B), be less than 10 sec ^-1 Conversely, antimony compound (C) is brominated flame retardant ( B) tends to be difficult to be embedded. Such shear rate is generally determined from the discharge amount of the resin composition and the shape of the cross section of the die nozzle. For example, when the cross section of the die nozzle is circular, it can be calculated by γ = 4Q / πr ^3. it can. Here, γ represents the shear rate (sec ⁻¹ ), Q represents the discharge amount of the resin composition per die nozzle (cc / sec), and r represents the radius (cm) of the die nozzle cross section.

  The resin composition extruded in a strand form from the die nozzle is cut into a pellet shape by a pelletizer or the like. In the present invention, the surface temperature of the strand during cutting is preferably 20 to 120 ° C., more preferably 25 to 115. It is preferable to cool the strands at a temperature of, preferably 30 to 100 ° C., particularly preferably 45 to 100 ° C. Usually, it is cooled by a method such as air cooling or water cooling, but water cooling is preferable in terms of cooling efficiency. In such water cooling, the strand may be cooled in a water tank containing water, and a desired strand surface temperature can be obtained by adjusting the water temperature and the cooling time. The shape of the pellets thus produced is preferably 1 to 8 mm in diameter, more preferably 2 to 6 mm, more preferably 3 to 5 mm, and more preferably 1 to 10 mm in length in the case of a columnar shape. Is 2 to 6 mm, more preferably 3 to 5 mm.

In the present invention, the relationship between the shear rate γ (sec ⁻¹ ) in the die nozzle and the surface temperature T (° C.) of the strand at the time of strand cutting is as follows:
5.1 × 10 ³ <(γ · T) <9.9 × 10 ⁵
By satisfying this relationship, the antimony compound (C) is embedded in the brominated flame retardant (B), which tends to improve electrical insulation, toughness, and flame retardancy. When the value of (γ · T) is 5.1 × 10 ³ or less, the antimony compound (C) is difficult to be embedded in the brominated flame retardant (B), and due to poor dispersion of each component of the resin composition The surface of the molded product tends to cause rough skin, and mechanical properties, flame retardancy, insulation properties, etc. tend to be unstable. Conversely, when it exceeds 9.9 × 10 ⁵ , it becomes difficult for the antimony compound (C) to be embedded in the brominated flame retardant (B), or the antimony compound (C) aggregates to embed it. Since the domain of the brominated flame retardant (B) to be enlarged is enlarged, the toughness may be lowered. The lower limit of (γ · T) is more preferably 6.2 × 10 ³ , and the upper limit is more preferably 8.5 × 10 ⁵ .
In order to adjust the value of (γ · T) within the above range, the shear rate and the surface temperature of the strand may be adjusted.

  In the present invention, a polyester resin composition having a morphological structure defined in the present invention can be produced by applying the above preferable conditions alone or in combination of a plurality thereof. It is effective to adopt production conditions such that the value of) satisfies the above formula.

  By adopting such a method for producing a polyester resin composition, it is possible to stably produce a polyester composition molded article having a morphological structure defined in the present invention. However, the production of the polyester resin composition of the present invention is not limited to such a method, and other methods may be used as long as the morphological structure defined by the present invention is obtained.

In addition, in order to easily form a molded article having a morphological structure according to the present invention, a molded article may be produced using a polyester resin composition to which the following methods and conditions 1) to 4) are applied. preferable.
1) As brominated flame retardant (B), brominated benzyl poly (meth) acrylate, particularly pentabromobenzyl polyacrylate is used. Brominated benzyl poly (meth) acrylate, in particular pentabromobenzyl polyacrylate, is a flame retardant with a pendant structure, with concentrated bromine atoms bonded to the benzene ring and strong electron-withdrawing properties. ) Are easily taken into the brominated flame retardant (B) dispersed phase, and the morphology in which the antimony compound (C) is embedded in the brominated flame retardant (B) dispersed phase is easily formed. The SP value of pentabromobenzyl polyacrylate is 26.0, which is larger than the SP value of 23.4 of the thermoplastic polyester resin (A). Therefore, it is considered that the antimony compound (C) is easily taken into the brominated flame retardant (B) phase.

2) The content of chlorine compounds as impurities in the brominated flame retardant (B) is usually 0.3% by mass or less, preferably 0.2% by mass or less, more preferably 0.15% by mass or less, It is preferably 0.08% by mass or less, particularly 0.03% by mass or less. By controlling in this way, it becomes easy to stably form the morphological structure defined in the present invention.
Chlorine compounds that are impurities are chlorobenzene, chlorinated styrene, chlorinated bisphenol compounds, etc. For example, when brominated flame retardant (B) is brominated benzyl poly (meth) acrylate, it is chlorobenzene, and chlorobenzene is present in the above amount. Then, it becomes difficult to stably form the morphological structure of the present invention. The chlorine compound content can be quantified as a value in terms of decane by analyzing a gas generated by heating at 270 ° C. for 10 minutes by a gas chromatography method.

3) Setting the amount of free bromine, chlorine and sulfur in the polyester resin composition to a specific amount or less is also effective in stably forming a morphological structure. The amount of free bromine is preferably 800 ppm or less, more preferably 700 ppm or less, further preferably 650 ppm or less, and particularly preferably 480 ppm or less. Moreover, since removing the content up to 0 ppm requires purification so as not to be economical, the lower limit is usually 1 ppm, preferably 5 ppm, more preferably 10 ppm.
The amount of free chlorine is preferably 500 ppm or less, more preferably 350 ppm or less, further preferably 200 ppm or less, and particularly preferably 150 ppm or less. In addition, the chlorine content in the resin composition is not limited in what state / form the chlorine was present in the resin composition. Chlorine is mixed in from various environments such as raw materials, additives, catalysts, polymerization atmosphere, resin cooling water, and the like, and therefore the total amount of these is preferably controlled to 500 ppm or less.
The amount of free sulfur is preferably 250 ppm or less, more preferably 200 ppm or less, further preferably 150 ppm or less, and particularly preferably 100 ppm or less. 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 those mixed to 250 ppm 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 was heated under an argon atmosphere at 270 ° C. for 10 minutes, The amount of chlorine and sulfur can be determined by quantitative determination using “ICS-90” manufactured by Nippon Dionex Co., Ltd.

4) Antimony trioxide is used as the antimony compound (C). Since antimony trioxide has higher activity than other antimony compounds, it is easily incorporated into the brominated flame retardant (B) dispersed phase, and the antimony compound (C) is embedded in the brominated flame retardant (B) dispersed phase. It is effective for stable formation of the morphology.

  These methods and conditions 1) to 4) may be applied alone or in combination, and may be applied in combination with the above-described resin composition production conditions.

[7. Stabilizer]
It is preferable that the polyester resin composition further contains a stabilizer because it has effects of improving thermal stability and preventing deterioration of mechanical strength 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
(Wherein R ¹ represents an alkyl group or an aryl group, which may be the same or different. N represents an integer of 0 to 2).
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, octadecyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonyl phenyl 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, geo Chill 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 Stub AX-71” of ADEKA Corporation.

As the organic phosphite compound, preferably, the following general formula:
^{R 2 O-P (OR 3} ) (OR 4)
Wherein 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 at least one of R ² , R ³ and R ⁴ One is an aryl group having 6 to 30 carbon atoms.).

  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 )
(Wherein 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 at least one of R ⁵ , R ⁶ and R ⁷ ) One is an aryl group having 6 to 30 carbon atoms.).

  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'-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3'-biphenylenediphospho 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.

  The content of the stabilizer is preferably 0.001 to 1 part by mass with respect to 100 parts by mass of the thermoplastic polyester resin (A). When the content of the stabilizer 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 during molding are likely to occur. When it exceeds, it will become excess amount and there exists a tendency for generation | occurrence | production of silver and a hue deterioration to occur further easily. The content of the stabilizer is more preferably 0.001 to 0.7 parts by mass, and still more preferably 0.005 to 0.5 parts by mass.

[8. Other flame retardants]
The polyester resin composition can also contain a flame retardant other than the brominated flame retardant (B). Examples of other flame retardants include phosphorus flame retardants and silicone flame retardants, and phosphorus flame retardants are preferred.

  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.

[9. Inorganic filler]
The polyester resin composition can contain an inorganic filler to improve its mechanical properties. Any conventional inorganic 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 this invention, it is preferable to contain an inorganic filler 100 mass parts or less with respect to 100 mass parts of thermoplastic polyester resins (A), especially 20-80 mass parts.

[10. Anti-dripping agent]
It is also preferable that the polyester resin composition contains an anti-dripping agent. As the anti-drip agent, polytetrafluoroethylene (PTFE) is preferable, has a fibril-forming ability, easily disperses in the resin composition, and shows a tendency to form a fibrous material by bonding the resins together. is there. 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 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 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. More preferably, the content rate of a dripping inhibitor is 0.1-10 mass parts with respect to 100 mass parts of thermoplastic polyester resins (A), Preferably it is 0.3-5 mass parts.

[11. Release agent]
The polyester resin composition preferably further contains a release agent. As the mold release agent, known mold release agents usually used for polyester resins can be used. Among them, polyolefin compounds, fatty acid ester compounds, and silicone systems are particularly difficult in that they do not hinder metal film adhesion. One or more mold release agents selected from compounds are preferred.

  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 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 the molding Cloudiness may be seen on the body surface. The content of the release agent is preferably 0.07 to 1.5 parts by mass, more preferably 0.1 to 1 part by mass.

[12. Other ingredients]
The polyester resin composition 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.

  Further, the polyester resin composition may contain a thermoplastic resin other than the thermoplastic polyester resin (A) as long as the effects of the present invention are not impaired. Specific examples of other thermoplastic resins include polycarbonate resin, polyacetal resin, polyamide resin, polyphenylene oxide resin, polystyrene resin, polyphenylene sulfide ethylene resin, polysulfone resin, polyether sulfone resin, polyetherimide resin, Examples include polyether ketone resins and polyolefin resins.

[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 molding method itself of the molded body is not particularly limited, and a molding method generally adopted for the polyester resin composition can be arbitrarily adopted. 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 blow molding methods, and in particular, injection molding methods such as injection molding methods, ultra-high speed injection molding methods, and injection compression molding methods are preferably applied.

  In injection molding, in order to obtain a molded article having a morphological structure defined in the present invention, for example, selection of molding machine conditions such as screw configuration of an injection molding machine, processing of an inner wall of a screw or cylinder, nozzle diameter, mold structure, etc. Various methods such as plasticization, measurement, adjustment of molding conditions during injection, addition of other components to the molding material, and the like can be mentioned. In particular, it is preferable to adjust, for example, cylinder temperature, back pressure, screw rotation speed, injection speed, and the like as conditions during plasticization, measurement, and injection. For example, when adjusting the cylinder temperature, it is preferably set to 230 to 280 ° C, more preferably 240 to 270 ° C. When adjusting the back pressure, it is preferably set to 2 to 15 MPa, more preferably 4 to 10 MPa. When adjusting a screw rotation speed, Preferably it sets to 20-300 rpm, More preferably, it sets to 20-250 rpm. When adjusting the injection speed, it is preferably set to 10 to 500 mm / sec, more preferably 20 to 400 m / sec.

A method of adding other components to the molding material is also effective. For example, a method of adding a lubricant to lower the resin melt viscosity at the time of injection molding or a method of adding a plasticizer to improve the fluidity of the resin composition is effective.
Examples of the lubricant and plasticizer include fatty acid metal salts such as stearic acid metal salts and montanic acid metal salts, aliphatic hydrocarbon compounds, higher alcohols, amide compounds, ester compounds, and the like. It is preferable to add in a range that does not have a great influence. 0.01-5 mass parts is preferable with respect to 100 mass parts of thermoplastic polyester resins (A), and, as for content of this lubricant and a plasticizer, 0.01-2 mass parts is more preferable. The lubricant and plasticizer may be blended during the production of the polyester resin composition pellets, or may be dry blended with the polyester resin composition pellets and used for molding.

The polyester resin composition molded article of the present invention preferably has a tensile elongation at break of 10% or more. Here, the tensile elongation at break is measured with a test piece (Type IV) having a thickness of 1 mm in accordance with ASTM D638.
The polyester resin composition molded article preferably has a comparative tracking index of 250 V or more. Here, the comparative tracking index is measured with a test piece having a thickness of 3 mm in accordance with CTI UL746A.

As described above, the molded article of the present invention is excellent in electrical properties such as flame retardancy and tracking resistance, and is also excellent in mechanical strength such as toughness, so that it can be used for applications that require thin or complicated shapes. It can be widely used, and 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 Examples and Comparative Examples, the components used are as shown in Table 1 below.

(Examples 1 and 2)
Engagement type co-directional twin-screw extruder (“TEX30α” manufactured by Nippon Steel Works Co., Ltd.), screw diameter so that each component described in Table 1 below has the blending ratio (part by mass) described in Table 2. 32 mm, L / D = 54.2) at 40 kg / hr. The barrel set temperature of the extruder is C1 to C15, the die is 250 ° C., the screw rotation speed is 200 rpm, the number of nozzles is 5 holes (circular (φ4 mm), length 1.5 cm), and the shear rate (γ) is 270 sec ⁻¹ . Extruded as a strand below. The strand temperature immediately after extrusion was 280 ° C.
The extruded strand was introduced into a water bath whose temperature was adjusted to 30 to 50 ° C. and cooled. The strand surface temperature (T) is cooled to 75 ° C. at a temperature measured with an infrared thermometer (γ · T = 2.0 × 10 ⁴ ), inserted into a pelletizer and cut, and pellets of the resin composition are obtained. Manufactured.
The obtained pellets were dried by heating at 120 ° C. for 7 hours, and using an injection molding machine (“J85AD” manufactured by Sumitomo Heavy Industries, Ltd.), the cylinder temperature was 250 ° C., the mold temperature was 80 ° C., the injection pressure was 150 MPa, A flat test piece of 60 mm × 60 mm × thickness 3 mm for morphological observation and flame retardancy under the conditions of injection holding time 15 sec, cooling time 15 sec, injection speed 100 mm / sec, back pressure 5 MPa, screw rotation speed 100 rpm Test specimens for evaluation of insulation properties and thin wall toughness were injection molded.

(Comparative Examples 1-4)
Engagement type co-directional twin-screw extruder (“TEX44αII” manufactured by Nippon Steel Works, Ltd.), screw diameter so that each component described in Table 1 below has a blending ratio (part by mass) described in Table 2. 47 mm, L / D = 55.2) at 250 kg / hr. The barrel set temperature of the extruder is C1 to C15, the die is 250 ° C., the screw speed is 230 rpm, the number of nozzles is 10 holes (circular (φ4 mm), length 1.5 cm), and the shear rate (γ) is 844 sec ⁻¹ . Extruded as a strand below. The strand temperature immediately after extrusion was 290 ° C.
The extruded strand was introduced into a water bath whose temperature was adjusted to 30 to 50 ° C. and cooled. The strand surface temperature (T) is cooled to 120 ° C. at a temperature measured with an infrared thermometer (γ · T = 1.0 × 10 ⁵ ), inserted into a pelletizer and cut, and pellets of the resin composition are obtained. Manufactured.
The obtained pellets were heated and dried at 120 ° C. for 7 hours, and using an injection molding machine (“J85AD” manufactured by Sumitomo Heavy Industries, Ltd.), the cylinder temperature was 250 ° C., the mold temperature was 40 ° C., the injection pressure was 150 MPa, A flat test piece of 60 mm × 60 mm × thickness 3 mm for morphological observation and flame retardancy under the conditions of injection holding time 15 sec, cooling time 15 sec, injection speed 80 mm / sec, back pressure 5 MPa, screw rotation speed 100 rpm Test specimens for evaluation of insulation properties and thin wall toughness were injection molded.

(1) Morphological observation:
Using the SEM / EDX analyzer, the core part of the obtained test piece cross section (the cross section perpendicular to the resin composition flow direction in the central part of the cross section in the part other than the surface layer part having a depth of less than 0.2 mm). The observation was made with a backscattered electron image at a magnification of 3,000 to 10,000 under an acceleration voltage of 20 kV to observe whether the antimony compound (C) was embedded in the brominated flame retardant (B) dispersed phase. . Further, the diameter of the brominated flame retardant (B) dispersed phase was calculated by measuring 50 particle diameters of each phase and calculating the arithmetic average. When the dispersed phase was not circular, the major axis and minor axis were measured, and the average value was taken as the diameter.
Moreover, about the surface layer part from the test piece surface to a depth of 0.2 mm, the brominated flame retardant (B) dispersed phase is in the flow direction by the reflected electron image having an acceleration voltage of 20 kV and a magnification of 3,000 to 10,000 times. It was observed whether it was oriented in a beaded manner.

The core part of the molded body of Example 1 is as shown in FIG. 1 (magnification: 10,000 times). As described above, the thermoplastic polyester resin (A) is a continuous phase, brominated flame retardant (B). Formed a dispersed phase, and it was confirmed that the antimony compound (C) had a morphology embedded in the brominated flame retardant (B) dispersed phase.
Further, as described above, it can be confirmed from the mapping images of bromine atoms and antimony atoms in FIGS. 2 and 3 that antimony is dispersed in the region where bromine exists, and the antimony compound (C) is bromine-based. It was judged that the flame retardant (B) was embedded in the dispersed phase.
Furthermore, as described above, in the surface layer portion of the molded body of Example 1, from FIG. 4 (magnification: 5,000 times) and FIG. 5 (magnification: 10,000 times), the brominated flame retardant (B) dispersed phase (white) It was also confirmed that the portion) extended in a rosary shape in the flow direction, and the antimony phase (and the white portion) entered and embedded therein.
Similarly in Example 2, the brominated flame retardant (B) forms a dispersed phase, and the antimony compound (C) is embedded in the brominated flame retardant (B) dispersed phase (see FIG. 6 (core part)). (Magnification: 10,000 times), and in the molded product surface layer portion, from FIG. 7 (magnification: 3,000 times) and FIG. 8 (magnification: 10,000 times), brominated flame retardant (B) dispersed phase (white part) It was confirmed that the antimony compound (C) phase (further white portion) entered and embedded in the beads in the flow direction.

  On the other hand, in the molded body core portions of Comparative Examples 1 to 4, the thermoplastic polyester resin (A) formed a continuous phase and the brominated flame retardant (B) formed a dispersed phase, but the antimony compound (C) was brominated. It was not embedded in the flame retardant (B) dispersed phase (see FIG. 9 (core part), magnification: 10,000 times). Further, in the surface layer of the molded body, the brominated flame retardant (B) dispersed phase does not extend in a bead shape in the flow direction, and the antimony compound (C) is not embedded in the brominated flame retardant (B) dispersed phase. (See FIG. 10 Magnification: 3,000 times and FIG. 11 Magnification: 10,000 times), and it was confirmed that it had a morphology different from Examples 1 and 2.

  Furthermore, the following flame retardancy, insulation properties, and thin-wall toughness evaluation test pieces were similarly subjected to morphology observation. As a result, the test specimens of 60 mm × 60 mm × thickness 3 mm for morphology observation were used. It was confirmed that it was the same morphological observation result.

Evaluation of flame retardancy, insulating properties, thin toughness, etc. was performed as follows.
(2) 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.

(3) Insulation characteristics:
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.
Note that the PLC criteria are: PLC2 is 250V ≦ CTI <400V, and PLC3 is 175V ≦ CTI <250V.

(4) Thin wall toughness (tensile strength, tensile elongation at break)
Based on ASTM D638, the tensile strength and the tensile elongation at break were measured for a test piece having a thickness of 1 mm. Higher tensile rupture elongation means higher toughness.

(5) Free bromine, chlorine, and sulfur content in brominated flame retardants and resin compositions:
Quantification was performed by combustion ion chromatography. Bromine generated by heating a 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 amounts of chlorine and sulfur were measured using “ICS-90” manufactured by Nippon Dionex Co., Ltd.

(6) Chlorine compound content in brominated flame retardants:
About 0.02 g of a brominated flame retardant was weighed and placed in a sample tube, and heat-treated at 270 ° C. for 10 minutes in an air stream of 30 ml / min of helium using TD-20 and column UA1701 manufactured by Shimadzu Corporation, −20 The total amount of generated gas was collected with a cryotrap cooled to ° C.
As conditions, column UA1701 (holding at 50 ° C. × 2 minutes, raising the temperature to 260 ° C. at 10 ° C./10 min, and further raising the temperature to 300 ° C. at 5 ° C./10 min) was used. The collected gas was introduced into the GC, the total ion chromatogram of the generated gas was measured, a detection amount was prepared using n-decane as an internal standard, and the chlorine compound content was quantified.
The above evaluation results are shown in Table 2.

  From Table 2, the following becomes clear. That is, it can be seen that the molded article of the polyester resin composition of the present invention is excellent in all of flame retardancy, insulating properties, and mechanical strength (thin toughness). On the other hand, it can be seen that the molded article of the comparative example which does not have the morphology of the present invention is poor in any of the above characteristics and does not satisfy all the effects of the present invention.

  The polyester resin composition molded body of the present invention is excellent in electrical properties such as flame retardancy and tracking resistance, and is also excellent in mechanical strength such as toughness. Therefore, the molded article of the present invention can be particularly suitably used as a thin molded part in an electric / electronic equipment part or the like. Moreover, since it can be used suitably also for automobile parts, building material parts, etc., industrial applicability is very high.

Claims (8)

A molded article comprising a polyester resin composition containing 3 to 60 parts by mass of a brominated flame retardant (B) and 0.5 to 20 parts by mass of an antimony compound (C) with respect to 100 parts by mass of the thermoplastic polyester resin (A). Because
The thermoplastic polyester resin (A) has a continuous phase, the brominated flame retardant (B) forms a dispersed phase, and the antimony compound (C) has a morphology embedded in the brominated flame retardant (B) dispersed phase. A molded body of a polyester resin composition characterized by   The polyester resin composition molded body according to claim 1, wherein the brominated flame retardant (B) dispersed phase embedding the antimony compound (C) is oriented in a beaded manner in the surface layer portion of the molded body.   The polyester resin composition molded article according to claim 1 or 2, wherein an average diameter of the brominated flame retardant (B) dispersed phase in the molded article core is 5 µm or less.   The polyester resin composition molded article according to any one of claims 1 to 3, wherein the main component of the thermoplastic polyester resin (A) is polybutylene terephthalate.   The polyester resin composition molded article according to any one of claims 1 to 4, wherein the brominated flame retardant (B) is pentabromobenzyl polyacrylate.   The polyester resin composition molded article according to any one of claims 1 to 5, wherein the antimony compound (C) is antimony trioxide.   The polyester resin composition molded article according to any one of claims 1 to 6, which has a tensile elongation at break (measured with a test piece (Type IV) having a thickness of 1 mm in accordance with ASTM D638) of 10% or more.   The polyester resin composition molded article according to any one of claims 1 to 7, wherein a comparative tracking index (measured with a test piece having a thickness of 3 mm based on CTI, UL746A) is 250 V or more.