JPS647105B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flame-retardant thermoplastic polyester composition that is flame-retardant, has excellent properties such as mechanical strength, and has excellent heat resistance in which the flame retardant does not migrate (bleed) to the surface of molded products at high temperatures. be. Terephthalic acid polyesters, such as polyethylene terephthalate (hereinafter abbreviated as PET) and polybutylene terephthalate (hereinafter abbreviated as PBT), generally have good mechanical properties, heat resistance, electrical properties, physical properties, chemical resistance, and dimensional stability. It is used in a wide variety of ways as a molding material because of its excellent properties in terms of properties and moldability. These polyesters mixed with reinforcing fillers such as glass fiber have dramatically improved mechanical strength and heat resistance, and have been put into practical use as effective materials for functional parts. However, once such polyester is ignited, it does not extinguish even if the fire source is removed and burns gradually, so it is considered a fatal defect from a fire safety perspective and is no longer used, especially in applications in the electrical and communication fields. Not suitable. A common method for making polyester flame retardant is to add organic halogen compounds, but if the amount added is increased solely for the purpose of imparting flame retardancy, the mechanical strength will decrease, so in reality, it is difficult to make polyester flame retardant. It is important to find unique combinations of flame retardant agents. Until now, methods for making polyester flame retardant include adding and mixing aromatic halogen compounds such as hexabromobenzene, decabromodiphenyl ether, brominated diphenyl, brominated phthalic anhydride, and brominated bisphenol A; It has been proposed to use a flame retardant aid such as antimony oxide, but in combination with such a halogen compound, the flame retardant itself bleeds onto the surface of the molded product at high temperatures, resulting in poor appearance and easy molding. In addition to causing a decrease in flame retardant efficiency due to sublimation, decabromodiphenyl ether, which is considered to be the most superior of these, has extremely poor dispersibility in polyester, making it difficult to form polymer compositions with sufficient mechanical strength. It was difficult. On the other hand, various flame-retardant polyesters using halogen-containing monomers are known for the purpose of uniformly dispersing flame retardants, improving physical properties, and reducing sublimation. , JP-A-49-78735, and JP-A-50-133253 propose a bromine-containing polyester made from a brominated aromatic dicarboxylic acid or its lower alkyl ester and an alkylene glycol; 49
-54494 publication describes halogen-containing aromatic diols,
Halogen-containing polyester copolymers from aliphatic diols and aromatic dicarboxylic acids have been proposed.
However, in the halogen-containing polyester obtained in this way, since the reactivity of the halogen-containing monomer is usually lower than that of a monomer that does not contain halogen, increasing the halogen-containing monomer in an attempt to increase the halogen content is not sufficient. It is not possible to obtain a polymer with a high molecular weight, and on the other hand, when trying to increase the molecular weight, the halogen-containing monomer must be reduced, resulting in a polymer with a considerably lower halogen content compared to ordinary additive flame retardants, and as a result, the base polymer becomes flame retardant. Even if it is blended in a large amount to form a base polymer or used itself as a base polymer, it has not been possible to obtain a material with sufficiently excellent mechanical strength and heat resistance. The present inventors focused on the uniform dispersibility and low sublimation of halogen-containing polyester in terephthalic acid polyester, and conducted intensive research to develop a non-bleeding flame retardant with excellent mechanical properties and heat resistance. As a result of stacking, it was found that by using a block copolymer of a specific halogen-containing polyester copolymer and a specific halogen-containing bisphenol A-type carbonate oligomer as an additive flame retardant, the halogen content and molecular weight of the halogen-containing polyester flame retardant can be improved. Furthermore, by combining this with an inorganic flame retardant additive, the amount of flame retardant added can be further reduced, resulting in a non-bleed flame retardant polyester with significantly higher mechanical strength retention than conventional polyesters. They succeeded in producing the composition and completed the present invention. That is, the present invention provides terephthalic acid polyester,
Or, to a polyester polyurethane obtained by reacting a low molecular weight polyalkylene terephthalate having a hydroxyl group at the end with a polyfunctional isocyanate, (a) terephthalic acid and/or its ester-forming derivative, alkylene glycol and the general formula [] (In the formula, R ₁ and R ₂ are alkylene groups; X is a chlorine or bromine atom; l ₁ and l ₂ are integers of 1 to 4; p and q
represents an integer from 1 to 10) A copolymerized polyester having a terminal hydroxyl group obtained by copolymerizing a halogen-containing aromatic diol represented by the general formula [] (In the formula, R ₃ and R ₄ are an alkoxy group or an aryloxy group; X is a chlorine or bromine atom; m ₁ and m ₂ are 1 to
An integer of 4; n represents an integer of 2 to 20. A flame-retardant thermoplastic resin composition comprising a block copolymer obtained by reacting a halogen-containing bisphenol A type carbonate oligomer represented by (b) and an inorganic flame retardant aid, the composition comprising: Based on the acidic polyester, (a) the effective halogen element of the block copolymer is 2 to 30% by weight, and (b) the inorganic flame retardant aid is 0.5 to 30% by weight.
The present invention provides a flame-retardant thermoplastic resin composition containing 20% by weight and further containing a reinforcing agent and/or an anti-dripping agent as required. The terephthalic acid polyester used in the present invention includes ester-forming derivatives such as terephthalic acid and/or lower alkyl terephthalic acid esters, alkylene glycols such as ethylene glycol, propylene glycol, butanediol,
A polyester consisting of pentanediol, neopentyl glycol, hexanediol, octanediol, decanediol, diethylene glycol, cyclohexanedimethanol, etc., usually phenol/tetrachloroethane = 6/4 (weight ratio)
The intrinsic viscosity [η] measured at 30℃ in a mixed solvent of
0.3 to 1.5 dl/g is used. This terephthalic acid polyester contains other polybasic acids such as isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, etc. in an amount of 40 mol% or less of the total acid components. α,β-bis(4-carboxyphenoxy)ethane, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, dimer acid, cyclohexanedicarboxylic acid, etc. and hydroxycarboxylic acids such as glycolic acid, hydroxybutyric acid, hydroxycaproic acid , hydroxybenzoic acid, hydroxyphenylacetic acid, naphthylglycolic acid, etc., and lactone compounds such as propiolactone, butyrolactone, valerolactone, caprolactone, etc., or polymers thereof. On the other hand, in addition to the above-mentioned glycol components, polyalkylene ether glycols such as polyethylene glycol and polytetramethylene ether glycol, aliphatic polyester oligomers having hydroxyl groups at both ends, in an amount of 40 mol% or less of the total glycol components, 2,2 --[4-(2-hydroxyethoxy)phenyl]propane, 1,4-bis(2-hydroxyethoxy)benzene and other aromatic-containing diols may be included. It may also contain polyfunctional ester-forming components such as trimethylolpropane, glycerin, pentaerythritol, trimellitic acid, trimesic acid, pyromellitic acid, etc. within a range that can maintain thermoplasticity. In addition, low molecular weight polyalkylene terephthalate having a hydroxyl group at the end ([η] = 0.1 to 0.5 dl/g)
A polyester polyurethane obtained by increasing the molecular weight with a polyfunctional isocyanate can also be used as the terephthalic acid polyester of the present invention. The block copolymers used as flame retardants in the present invention include terephthalic acid and/or its ester-forming derivatives, alkylene glycols, and the general formula [] A copolymerized polyester having a terminal hydroxyl group (hereinafter referred to as copolyester) obtained by copolymerizing a halogen-containing aromatic diol represented by (the symbols in the formula are as described above) and the general formula [] It is a block copolymer with a halogen-containing bisphenol A type carbonate oligomer represented by (the symbols in the formula are as described above). As the acid component of the copolymerized polyester used at this time, terephthalic acid is used in consideration of compatibility with the terephthalic acid polyester, but in addition to terephthalic acid, the various polybasic acids mentioned above, in an amount of 40 mol% or less, In addition to hydroxycarboxylic acids and lactone compounds, halogen-containing acids such as tetrabromophthalic acid and its anhydride, tetrabromoterephthalic acid,
It may also contain dibromoterephthalic acid and the like. The alkylene glycol used as a raw material for the copolymerized polyester includes the various alkylene glycols mentioned above as the glycol component of the terephthalic acid polyester, as well as other alkylene glycols.
The various diols mentioned above may be used in combination in an amount of 40 mol% or less. Further, the above-mentioned polyfunctional ester-forming component that can be used in the terephthalic acid polyester may be used in a small proportion. The halogen-containing aromatic diol, which is the essential third component of the copolyester, has the general formula [] ((In the formula, R ₁ and R ₂ are alkylene groups; X is a chlorine or bromine atom; l ₁ and l ₂ are integers of 1 to 4; p and q
represents an integer from 1 to 10. ). These halogen-containing aromatic diols can be prepared, for example, by adding a suitable alkylene oxide such as ethylene oxide or propylene oxide to halogenated bisphenol A, or by reacting an alkylene halohydrin such as ethylene chlorohydrin. However, R ₁ , R ₂ , p, q may vary depending on the type of raw materials used, molar ratio, and reaction conditions.
is decided. Particularly preferred are those in which R ₁ and R ₂ are ethylene or propylene groups; p and q are 2 to 4; and X is a bromine atom. Specific examples include 2,2-bis[4-(2-hydroxyethoxy)3,5-dibromophenyl]propane, 2,2-bis[4-
(2-hydroxyethoxy)3,5-dichlorophenyl]propane, 2,2-bis[4-(2-hydroxypropoxy)3,5-dibromophenyl]propane, 2,2-bis[4-(2 -hydroxypropoxy)3,5-dichlorophenyl]propane, 2,2-bis[4-(3-hydroxypropoxy)3,5-dibromophenyl]propane, 2,2-bis[4-(3-hydroxy) propoxy)3,5-dichlorophenyl]propane,
2,2-bis[4-(2-hydroxyethoxy)
3-bromophenyl]propane, 2,2-bis[4-(2-hydroxyethoxy)2,3,5,
Examples include 6-tetrabromophenyl]propane. Conventionally known methods can be used to copolymerize these three essential components to produce a copolymerized polyester. For example, a method in which the above three components are charged and a transesterification reaction or an esterification reaction is performed, followed by a polycondensation reaction if necessary, or a method in which terephthalic acid or terephthalic acid ester is reacted with an alkylene glycol in advance to form bis(hydroxyalkyl)terephthalate or After producing the oligomer, it can be produced by a method in which a halogen-containing aromatic diol represented by the general formula [] is added to perform a polycondensation reaction. The amount of the halogen-containing aromatic diol is selected from a range such that the halogen content in the copolymerized polyester obtained is usually 10 to 43% by weight, preferably 25 to 43% by weight. Further, the average molecular weight of the copolymerized polyester used is usually 1,000 to 20,000, preferably 1,500 to 15,000. On the other hand, the other component of the block copolymer, the halogen-containing bisphenol A-type carbonate oligomer, has the general formula [] (In the formula, R ₃ and R ₄ are an alkoxy group or an aryloxy group; X is a chlorine or bromine atom; m ₁ and m ₂ are 1
An integer of ~4; n represents an integer of 2-20. ). The halogen-containing bisphenol A type carbonate oligomer represented by the general formula [] can be prepared by a commonly known method. For example, a method of reacting halogenated bisphenol A, a chain terminator, and phosgene, carbonate, or chloroformate may be mentioned. The degree of polymerization of the oligomer can be controlled by the molar ratio of halogenated bisphenol A and chain terminator, and the chain terminators include methyl alcohol,
Monofunctional compounds such as ethyl alcohol, isopropyl alcohol, phenols, alkylphenols, monohydroxy compounds such as halogenated phenols, and monocarboxylic acids such as acetic acid, propionic acid, and benzoic acid are used. In addition, as another production method, after preparing a halogenated polycarbonate oligomer having a phenolic hydroxyl group at the terminal from halogenated bisphenol A and phosgene,
acetyl chloride, propionyl chloride,
Also included is a method of reacting with an acylating agent such as benzoyl chloride and acetic anhydride, or a carbonate such as dialkyl carbonate and diphenyl carbonate. Specific examples of halogen-containing bisphenol A type carbonate oligomers represented by the general formula [] include tetrabromobisphenol A, tetrabromo bisphenol A, and tetrabromobisphenol A having a terminal group such as methyl, ethyl, isopropyl, phenyl, acetyl, propionyl, benzoyl, etc. It is a carbonate oligomer of chlorobisphenol A, dibromobisphenol, and dichlorobisphenol A, and a portion of halogenated bisphenol A may be substituted with bisphenol A. The degree of polymerization n of these halogenated bisphenol A type carbonate oligomers is 2 to
20, preferably in the range of 2 to 10; if n is less than 2, low molecular weight substances that were not copolymerized may bleed onto the surface of the molded product if the block polymerization with the copolyester is incomplete. Moreover, when n exceeds 20, the melting point of the carbonate oligomer becomes high, resulting in poor dispersibility and reactivity, resulting in a decrease in physical properties, which is not preferable. A block copolymer of a halogen-containing aromatic diol copolymerized polyester and a halogenated bisphenol A-type carbonate oligomer is produced by melt-mixing both of them above their melting points and polymerizing them under known polyester polycondensation reaction conditions, that is, with dealcoholization. It can be obtained by For example, it can be obtained by adding an organotin compound, an organotitanium compound, an antimony compound, a germanium compound, etc. as a catalyst, and polycondensing the mixture at 200° C. to 300° C. under reduced pressure of 1 mmHg or less while melting and stirring. In addition, after uniformly melting and mixing the catalyst in both, the catalyst is taken out, solidified and pulverized, and then heated at a temperature 10 to 50 degrees Celsius lower than their melting points under an inert air stream or under a reduced pressure of 1 mm or less to form the so-called solid phase. A block copolymer can also be obtained by polymerization. The ratio of the polyester copolymer to the carbonate oligomer in the block copolymer is preferably 90 to 20 to 10 to 80 (weight ratio), in order to maintain good compatibility of the block copolymer flame retardant with the terephthalic acid polyester. The polyester copolymer component in the block copolymer is 20% by weight.
The above is necessary. In addition, the content of the halogen element in the block copolymer (flame retardant) is usually 25 to 55% by weight, preferably 30 to 55% by weight, and if the halogen content is low, the amount of flame retardant relative to the terephthalic acid polyester will inevitably increase. This is undesirable because it causes a decrease in the mechanical properties of the resulting composition. The appropriate amount of the halogen-containing block copolymer of the present invention is such that the amount of halogen element in the block copolymer is in the range of 2 to 30% by weight based on the terephthalic acid polyester. If the amount of halogen element in the block copolymer relative to the terephthalic acid polyester is less than 2% by weight, the flame retardance of the composition will not be sufficient, and if it exceeds 30% by weight, the amount of the block copolymer will be insufficient. If the amount increases, the physical properties of the terephthalic acid polyester will deteriorate significantly. The composition of the present invention contains an inorganic flame retardant aid, and by using this flame retardant aid in combination, the amount of flame retardant used can be reduced, thereby making it possible to further reduce the deterioration of the mechanical properties of the composition. Examples of such inorganic flame retardant aids include antimony trioxide, antimony tetroxide, antimony pentoxide, antimony trisulfide, sodium antimonate, sodium pyroantimonate, tin dioxide, barium metaborate, zinc borate, and hydroxide. Examples include aluminum, zirconium oxide, and molybdenum oxide. In addition, the amount of inorganic flame retardant aid is 0.5 to 20 per terephthalic acid polyester.
Amounts in the range of % by weight are preferred. The amount
If it is less than 0.5% by weight, the effect as a flame retardant aid will be small, and if it exceeds 20% by weight, the mechanical strength will be significantly reduced. Particularly preferably, the amount of the inorganic flame retardant aid is 1 to 1, based on the terephthalic acid polyester.
It is 10% by weight. The composition of the present invention may contain inorganic compounds such as glass fibers, carbon fibers, glass beads, mica, and talc as reinforcing agents. The reinforcing agent that can be used is preferably one treated with a silane coupling agent such as vinyl silane, aminosilane, or epoxy silane or a titanium coupling agent, and the shape may be roving, chopped strand, bead, flake, powder, etc. Can be supplied. The amount of such reinforcing agent used is preferably 5 to 60% by weight in the composition, but if the amount is less than 5% by weight, the reinforcing effect will be small, and if it exceeds 60% by weight, the composition will not be processed properly. This is not preferable because it results in poor properties. The composition of the present invention may optionally contain asbestos or/and ethylene-vinyl acetate copolymer as a melt dripping preventive agent, and these compounds are usually 1 to 10% by weight of the total composition, preferably is 1
It is blended at ~5% by weight. The ethylene vinyl acetate copolymer preferably has a vinyl acetate content of 50% by weight or more. These compounds are preferred because they provide the effect of preventing dripping of the melt during combustion of the composition. Further, the composition of the present invention can be used in combination with other organic polymers, such as polyolefin, polystyrene, AS, etc.
Resin, ABS resin, MBS resin, ASA resin, acrylic resin, vinyl acetate resin, polyacetal, polycarbonate, polyester, polyurethane,
Examples include polymers such as polyamide, modified PPO resin, and ionomer, and elastomers and rubbers such as acrylic rubber graftomer, styrene-butadiene rubber, ethylene-propylene rubber, and polyester ether elastomer. The amount of such other organic polymers is suitably 40% by weight or less in total with the terephthalic acid polyester or the polyester polyurethane reacted with a low molecular weight polyalkylene terephthalate polyfunctional isocyanate having a hydroxyl group at the end. The copolymerized polyester, which is a constituent component of the block copolymer in the present invention, not only has the effect of improving compatibility with the terephthalic acid polyester, but also has the effect of improving the compatibility with the terephthalic acid polyester. Since it partially undergoes transesterification with the acidic polyester, it is preferred because it is effective in improving the physical properties of the resulting composition and preventing bleeding of the flame retardant. Any method can be adopted to produce the composition of the present invention, for example, a block copolymer is added and mixed during the polycondensation reaction of terephthalic acid polyester or after the reaction is completed, and then an inorganic flame retardant aid is added, if necessary. According to the method, a reinforcing agent and an anti-dripping agent are added and mixed, and the molten terephthalic acid polyester and the block copolymer are uniformly melt-mixed, then cooled and solidified, and pulverized. A method of mixing a reinforcing agent and an anti-dripping agent depending on the situation, or a method of mixing a terephthalic acid-based polyester pellet, block copolymer granules, an inorganic flame retardant aid, and a reinforcing agent and an anti-dripping agent as necessary. etc. When kneading the composition of the present invention, it is preferable to use a continuous kneader such as an extruder, and suitable conditions are a heating temperature of 180 to 300°C and a kneading time of 0.2 to 30 minutes. If the temperature is too high or the kneading time is too long, the block copolymer is likely to decompose, so care must be taken. The mechanical properties and hydrolysis resistance of the composition of the present invention can be improved by further using a compound containing two or more epoxy groups depending on the purpose.
Furthermore, heat resistance, light resistance, moldability, etc. can be improved by using carboxylic acid metal salts and waxes together. The composition of the present invention may further contain crystal nucleating agents, fillers, plasticizers, lubricants, mold release agents, matting agents, heat stabilizers, antioxidants, ultraviolet absorbers, coupling agents, blowing agents, and other additives. A flame retardant or the like may be added. The flame-retardant thermoplastic polyester resin composition obtained in this way has excellent flame retardancy, and also has excellent mechanical, physical, electrical, thermal, chemical, etc. properties, and has no flame retardant. Because it does not bleed onto the surface of the molded product, its industrial value is extremely high, and it can be used for mechanical parts, electrical and electronic parts, automobile parts, building material parts,
It can be used not only for molding miscellaneous goods, but also for fibers, films, adhesives, etc. EXAMPLES Hereinafter, examples will be given to explain the present invention more specifically, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Note that parts and % in the examples indicate parts by weight and % by weight, respectively. Reference Example 1 (Synthesis of tetrabromobisphenol A type carbonate oligomer) 500 parts of methylene chloride and 340 parts of a 7% aqueous sodium hydroxide solution were placed in two flasks equipped with a stirrer, thermometer, PH electrode, phosgene blowing tube, and reflux condenser tube. Department,
163 parts of tetrabromobisphenol A, 8 parts of phenol, and 0.7 parts of triethylamine were charged, stirred and dissolved, and phosgene was added while maintaining the liquid temperature at 20°C.
38 parts were infused over 60 minutes. After the blowing was completed, stirring was continued for 15 minutes, and after the reaction was completed, the methylene chloride layer was neutralized and washed with water, and the solvent was evaporated to obtain a white powdery product. Add 150 parts of this product to methylene chloride.
Dissolved in 500 parts of 3% sodium hydroxide aqueous solution 500 parts
1 part and 30 parts of 28% aqueous ammonia were added, and the mixture was stirred at room temperature for 60 minutes. While continuing to stir, neutralize with phosphoric acid until the aqueous layer becomes acidic, separate the aqueous layer, and evaporate the solvent to obtain a white powdery carbonate oligomer (A).
I got it. The main product of this product was a carbonate oligomer having the following structure, a number average molecular weight of 4150, and a degree of polymerization of about 6. Similarly, a methoxy-terminated carbonate oligomer (B) having a number average molecular weight of 2850 and a degree of polymerization of about 4 was synthesized using methanol instead of phenol as a terminal capping agent. Reference Example 2 (Synthesis of halogen-containing block copolymer flame retardant) 388 g of dimethyl terephthalate was placed in two flasks equipped with a stirrer, a thermometer, an N ₂ inlet tube, and a cooling tube.
126g of 1,4-butanediol, 1011g of 2,2-bis[4-(2-hydroxyethoxy)3,5-dibromophenyl]propane and 0.76g of tetraisopropyl titanate were charged, and the mixture was heated at 200°C to approx.
The transesterification reaction was carried out for an hour. The amount of distillate (mixture of methanol, 1,4-butanediol, tetrahydrofuran, and water) was 164 g. Next, 600 g of this copolymerized polyester, 400 g of the oligocarbonate (A) of Reference Example 1, and 0.6 g of tetraisopropyl titanate were charged into a reaction vessel equipped with a stirrer for reducing pressure, and the mixture was heated at 250°C and under reduced pressure of 0.5 mmHg.
A polycondensation reaction was carried out for 2.5 hours to obtain a block copolymer flame retardant (a) having a relative viscosity (solvent: phenol/tetrachloroethane = 6/4, measured at 30°C) of 1.60 and a bromine content of 45.8%. Similarly, block copolymer flame retardants (B) (C) (D) (E)
was synthesized.

[Table] Example 1 Transesterification and polycondensation of dimethyl terephthalate and 1,4-butanediol were carried out by a known method, and the obtained intrinsic viscosity [η] = 0.8 dl/g
Before taking out 100 parts of PBT from the polycondensation kettle, 35 parts of the block copolymer (a) synthesized in Reference Example was added, and after mixing at 245°C for 20 minutes under normal pressure, the mixture was taken out from the kettle, cooled, solidified, and granulated. To this mixture, 5 parts of antimony trioxide and 60 parts of chopped strand type glass fiber treated with an epoxy silane coupling agent were premixed uniformly. The premix was supplied to a full-flight vented 65 mm extruder heated to 250°C, and after plasticization and kneading, the mixture was cooled to obtain pellets. A test piece was made from this pellet using an injection molding machine, and its physical properties were measured. US UL (=
Flammability tests based on the Underwriters' Laboratories (Underwriters' Laboratories) standards were conducted on 1/16 inch thick specimens. Heat resistance was qualitatively evaluated by thermal coloring after the molded specimen was kept in a dryer at 200°C for 2 hours. These results are summarized in Table 2. Examples 2 and 3 In Example 1, the flame retardants (B) and (C) shown in Table 1 were used instead of the block copolymer flame retardant (A), and the other conditions were the same as in Example 1. Obtain a molded product for testing,
The evaluation results are shown in Table 2. Comparative Example 1 A test molded article was obtained in the same manner as in Example 1 except that 22 parts of decabromodiphenyl ether was used instead of the block copolymer flame retardant (a), and the evaluation results are as follows. are shown in Table 2. Comparative Example 2 In Example 1, instead of the block copolymer flame retardant (a), 21 parts of the copolymerized polyester (relative viscosity 1.25, acid value 0.8, bromine content 39%) which is a component of (a) and A test molded article was obtained in the same manner as in Example 1 except that 14 parts of the bromine-containing carbonate oligomer (A) was used, and the evaluation results are shown in Table 2. Comparative Example 3 A molded article was obtained in the same manner as in Example 1 except that the block copolymer flame retardant was not added, and its physical properties were evaluated. The results are shown in Table 2.

[Table] As is clear from the evaluation results in Table 2, the composition of the present invention had excellent performance in all physical properties, exhibited little discoloration in a high-temperature atmosphere, and no bleeding was observed. On the other hand, when decabromodiphenyl ether was used as in Comparative Example 1, the mechanical properties deteriorated and bleeding was severe, making it practically useless. Further, in Comparative Example 2, which used the constituent components before block copolymerization, the mechanical properties were considerably deteriorated, and discoloration and bleeding were observed in a high-temperature atmosphere. Examples 4 to 8 PBT, PET as polyester, and polyester urethane obtained by reaction of PBT and isocyanate, antimony trioxide, sodium pyrophosphate, and stannic oxide as flame retardant additives in the proportions shown in Table 3 Pellets were obtained in the same manner as in the examples, and then test molded products were prepared and their physical properties were tested. The results are summarized in Table 3.

[Table] As is clear from the results in Table 3, the molded products of Examples 4 to 8 of the present invention all have excellent mechanical properties and flame retardancy, and are resistant to discoloration in high-temperature atmospheres. There was no evidence of bleeding.

Claims (1)

[Claims] 1. Forming (a) terephthalic acid and/or its ester in a polyester polyurethane obtained by reacting a terephthalic acid-based polyester or a low molecular weight polyalkylene terephthalate having a hydroxyl group at the end with a polyfunctional isocyanate. sexual derivatives, alkylene glycol and general formula [] (In the formula, R ₁ and R ₂ are alkylene groups; X is a chlorine or bromine atom; l ₁ and l ₂ are integers of 1 to 4; p and q
represents an integer from 1 to 10. ) A copolymerized polyester having a terminal hydroxyl group obtained by copolymerizing a halogen-containing aromatic diol represented by the general formula [] (In the formula, R ₃ and R ₄ are an alkoxy group or an aryloxy group; X is a chlorine or bromine atom; m ₁ and m ₂ are 1 to
An integer of 4; n represents an integer of 2 to 20. ) and (b) an inorganic flame retardant aid, and (a)
The effective halogen element of the block copolymer is 2 to 30% by weight based on the terephthalic acid polyester or polyester polyurethane, and (b) the inorganic flame retardant aid is 0.5 to 20% by weight based on the terephthalic acid based polyester or polyester polyurethane. A flame-retardant thermoplastic resin composition characterized by: