JPS6146494B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to flame-retardant thermoplastic polyester resin compositions. More specifically, the present invention relates to a flame-retardant thermoplastic polyester that has excellent heat resistance, does not transfer flame retardant to the surface of molded products at high temperatures (referred to as bleed), and has high mechanical strength. Terephthalic acid or its ester and carbon number is 2~
Thermoplastic polyesters (hereinafter abbreviated as PEs) formed from glycols No. 4, such as polyethylene terephthalate (hereinafter abbreviated as PET) and polybutylene terephthalate (hereinafter abbreviated as PBT), generally have good mechanical properties and heat resistance. It is widely used as a molding material because of its excellent properties such as properties, electrical properties, physical properties, chemical resistance, dimensional stability, and moldability. These PEs 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 PEs 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 not suitable for use, especially in electrical and communications fields. do not have. Accordingly
In order to impart flame retardancy to PEs, this can be achieved by adding and mixing organic halogen compounds such as hexapromobenzene and decabromo biphenyl ether, or by using flame retardant aids such as inorganic compounds such as antimony trioxide. It had been. However, products containing these organic halogen compounds have poor appearance because the organic halogen compounds on the surface of the molded product bleed at high temperatures, and have poor moldability due to poor heat resistance. It also has the disadvantage of yellowing and discoloration. The present invention is the result of extensive research and discovery of a flame-retardant PEs composition that improves the bleeding of flame retardants, has excellent heat resistance, and has high mechanical strength. That is, the present invention uses 100 parts by weight (hereinafter referred to as parts) of PEs (A) synthesized from terephthalic acid or its ester and a glycol having 2 to 4 carbon atoms, halogenated bisphenol A or/and bisphenol A, a polycarbonate (a) with a polymerization degree of 2 to 10 having a hydroxyl group at the end synthesized from phosgene, halogenated bisphenol A or/and bisphenol A, and epichlorohydrin or β-methylepichlorohydrin. The epoxy resin (b) with a degree of 5 or less and the epoxy group equivalent of (b) / (a)
A flame retardant compound consisting of 3 to 50 parts of an epoxy compound (B), 0.1 to 20 parts of an inorganic flame retardant aid (C), and 0 to 150 parts of an inorganic filler (D), which are obtained by reacting in a proportion of hydroxyl equivalents of ≧2. A resin composition is provided. Polycarbonate (a), which is one of the raw materials for flame retardants, has the structure shown below. In addition, the other raw material component, epoxy resin (b)
has the following structure. Each of the above compounds (a) or (b) is used alone as a flame retardant. However, for example, when a composition similar to the present invention is obtained using only (a), the mechanical strength of the molded product is low, and when the molded product is left at a high temperature of, for example, 150°C, the white color turns brown. The color changes to such an extent that it becomes of no practical value in terms of appearance. On the other hand,
When a composition similar to the present invention is obtained using only (b) as a flame retardant, if (b) has a melting point of 100°C or less such as l+m≦1.5, when compounding this composition with an extruder, (b) melts and the raw material slips, making it difficult to feed the extruder, making compounding impossible. Furthermore, in this case, since the molecular weight of (b) is low, the mechanical strength of the composition is also very low. In addition, if (b) has a high molecular weight of l+m>1.5 or more, the melting point will be over 100℃, so compounding will be smooth, but it will lead to heat coloring during molding, and molded products under high temperatures will not be able to be used. Thermal coloring occurs and the mechanical strength of the molded product becomes low. Polycarbonate (a) and epoxy resin (b) of the present invention
It has surprisingly been found that the above-mentioned drawbacks can be improved by using a flame retardant prepared by reacting epoxy equivalent of (b)/hydroxyl equivalent of (a)≧2. In other words, the heat resistance of the flame retardant is significantly improved, there is little heat discoloration during molding, there is very little heat discoloration of the molded product at high temperatures, and the mechanical strength is also lower than that of products that do not contain flame retardants. was very small. Furthermore, the flame retardant of the present invention has a high melting point of 100°C or higher, has excellent compounding properties, and has a high molecular weight.
Because it has good compatibility with PEs, it does not bleed onto the surface of molded products. Polycarbonate (a) used herein in the present invention
is usually synthesized by the following method. for example,
Terminal chloroformate of low polymerization degree halogenated aromatic polycarbonate obtained by reacting a halogenated aromatic dihydroxy compound dissolved in an alkaline aqueous solution in the presence of an inert organic solvent and amines with phosgene while adjusting the pH to 10 to 11. It is obtained by hydrolyzing the group with aqueous ammonia and aqueous alkaline solution. Next, the epoxy resin (b) is usually synthesized by the following method. Generally, it is obtained by condensation of halogenated bisphenol A or a mixture of this and bisphenol A with epichlorohydrin. , easily obtained by heating to 80-250°C. Furthermore, the reaction between (a) and (b) is usually carried out as follows. For example, (b) is obtained by reacting tetrabromobisphenol A diglycidyl ether and tetrabromobisphenol A at a ratio of 1 equivalent of hydroxyl group or less to 1 equivalent of epoxy group at 80 to 250°C using tetramethylammonium chloride as a catalyst. Gain,
Next, a low degree of polymerization aromatic polycarbonate (a) having hydroxyl groups at both ends is added and reacted. Here, the quantitative ratio of (a) and (b) is (b)
Epoxy equivalent of / hydroxyl equivalent of (a) ≧2,
If the ratio is less than 2, the viscosity of the melt reaction system becomes abnormally high, making it difficult to continue the reaction, and also having the disadvantage of poor heat coloring resistance. Furthermore, this ratio is
It is preferable that the number does not exceed 10, and if it exceeds 10, the desired effect will not be exhibited because the amount of reaction (a) will be small, which is not preferable, and the number is more preferably 2 to 7. or,
For the purpose of preventing abnormal thickening, etc., monofunctional compounds such as monophenols, monoalcohols, monoepoxies, etc. may be used in combination to the extent that the effects of the present invention are not impaired. The amount of the flame retardant of the present invention, that is, the epoxy compound (B) is
It is 3 to 50 parts per 100 copies of PEs. If the amount is less than 3 parts, flame retardancy is not sufficient, and if it exceeds 50 parts, PE
The physical properties of the material deteriorate significantly. The flame retardant effect depends on the absolute amount of halogen in the flame retardant. Therefore,
A suitable amount of halogen atoms is 1 to 30 parts per 100 parts of PEs. The PEs used in the present invention are synthesized from terephthalic acid or its esters represented by PET and PBT and glycols having 2 to 4 carbon atoms, and have an intrinsic viscosity [η] (phenol and tetrachloroethane). (Measured at 30℃ in a mixed solvent with a weight ratio of 6:4)
0.5 to 1.5 d/g is usually used. An amount of 40 mol% or less of each of the acid component or alcohol component, for example, as an acid component, an aliphatic dicarboxylic acid such as adipic acid or sebacic acid, an alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid, or an aromatic dicarboxylic acid such as isophthalic acid; Alcohol components include ethylene glycol, 1,2-butanediol,
Aliphatic glycols such as 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, alicyclic glycols such as 1,4-cyclohexanedimethanol, 4,4'-hydroxyethyl-
Examples include aromatic glycols such as oxyphenylpropane. In addition, PEs can contain up to 40% by weight of polyolefins, polystyrene, AS,
It can be used in place of thermoplastic resins such as ABS, acrylic resin, vinyl acetate resin, polyacetal, polycarbonate, polysulfone, polyphenylene sulfide, various nylons, and polyurethane. Furthermore, low molecular weight PEs ([η]: 0.15-0.5d/g) with a hydroxyl group at the end are used as PEs.
It is also possible to use polyester polyurethane obtained by increasing the molecular weight with a polyfunctional isocyanate. The flame retardant aid in the present invention is preferably an inorganic compound, such as antimony trioxide, antimony tetroxide, antimony pentoxide, sozo pyroantimonate, tin dioxide, barium metaborate, zinc borate, aluminum hydroxide, zirconium oxide,
Examples include molybdenum oxide. The amount of flame retardant aid used is 0.1 to 20 per 100 parts of PEs.
parts, preferably 1 to 15 parts; if it is less than 0.1 parts, the flame retardancy will be poor, and if it exceeds 20 parts, the strength of the composition will be reduced. The evaluation of the flame retardancy of the composition in the present invention is determined according to Subdivision 94 (UL94) of the American Underwriters Laboratories standard. Specifically, first, a test piece was made into a length using an injection molding method.
A size of 5" x width 1/2" x thickness 1/16" or 1/32" is prepared and used. Use 1000 BTU of gas mainly composed of methane gas as the fire source, and use a 3/8″ inner diameter,
Adjust the height of the blue flame without yellow tips to 3/4" using a 4" long burner. Fix the specimen so that its length is vertical, and set it so that the distance between the bottom edge of the specimen and the top of the burner is 3/8". Remove the indirect flame from the specimen for 10 seconds, and then The time during which the sample is heated (first burning time)
Record. Then, as soon as the fire is extinguished, 10
Flame for seconds and record the second burn time after removing the flame. After the second combustion, record the time during which the specimen emits a red afterglow (afterglow time).
In addition, it is observed whether the molten part of the specimen falls downward and ignites the installed cotton during the time of contact with the flame or the subsequent combustion time and afterglow time. Examples of the reinforcing filler in the present invention include glass fiber, carbon fiber, calcium carbonate, calcium silicate, magnesium silicate, asbestos, calcium sulfate, barium sulfate, iron oxide, mica, aramid fiber, glass beads, glass powder, Examples include graphite. In particular, the use of glass fiber exhibits a number of features such as significantly improved mechanical properties and heat resistance, and reduced mold shrinkage. Examples of glass fibers include:
Those treated with vinyl silane, amino silane, and epoxy silane coupling agents are used.
It can be supplied in the form of roving glass, chopped strand glass or milled glass. The amount of glass fiber used is preferably 5 to 150 parts, preferably 10 to 100 parts, per 100 parts of PEs. Also, the diameter of glass fiber is 0.005~0.02mm,
Its length is preferably 0.01 to 10 mm, preferably 0.05 to 1 mm. If the length of the glass fiber is too short, the reinforcing effect will not be sufficient, and if it is too long, the surface finish of the molded product will be poor and the molding processability will be poor.
Further, if the amount of glass fiber exceeds 150 parts, the molding processability of the composition becomes poor, which is not preferable. The glass fiber coupling agent is a major factor in determining the strength of the composition. Such coupling agents include in particular γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N-β-(aminoethyl)-γ
- Aminosilanes such as aminopropyldimethoxymethylsilane; Epoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. is preferred. The composition of the present invention may contain other additives such as crystal nucleating agents, pigments, dyes, plasticizers, mold release agents, lubricants, heat stabilizers, antioxidants, ultraviolet absorbers, blowing agents, coupling agents, etc. It may be used in combination with other flame retardants. Next, Examples will be given to explain the present invention in more detail. In the examples, % is clearly indicated as weight %.
shall represent. Reference Example 1 (Synthesis of low polymerization degree polycarbonate (a) having a hydroxyl group at the end) 163 parts of tetrabromobisphenol A dissolved in 500 parts of methylene chloride and 340 parts of a 7% aqueous sodium hydroxide solution and 0.73 parts of triethylamine were charged into a flask. , keep the liquid temperature at 20℃, and keep the pH around 11.
To adjust the temperature, 25 parts of phosgene was blown in over 60 minutes while dropping a 7% aqueous sodium hydroxide solution.
After blowing, continue stirring for 15 minutes. After the reaction was completed, the methylene chloride layer was neutralized, washed with water, and the solvent was evaporated to obtain a white powdery product. Dissolve 150 parts of this product in 500 parts of methylene chloride and
% aqueous sodium hydroxide solution and 30 parts of 28% aqueous ammonia were added, and the mixture was stirred at room temperature for 60 minutes. Further, while stirring was continued, the aqueous layer was neutralized with phosphoric acid until it became acidic, and after separating the aqueous layer, the solvent was evaporated to obtain a white powdery low degree of polymerization polycarbonate. This product has a number average molecular weight in which the main product has the following structure:
2820, a polycarbonate with a degree of polymerization of about 4. Reference Example 2 (Synthesis of halogenated epoxy resin (b)) 720 parts of tetrabromobisphenol A diglycidyl ether (epoxy equivalent: 360) and 109 parts of tetrabromobisphenol A were placed in a flask and heated at 150°C.
After heating and dissolving the mixture, 0.27 part of a 10% aqueous solution of tetramethylene ammonium chloride was added, the temperature was gradually raised to 170°C after 1 hour, and the mixture was further stirred at 170°C for 2 hours. After the reaction was completed, it was cooled and solidified. The product is a melting point 67℃ epoxy equivalent whose main component has the following structure:
680 halogenated epoxy resin. Reference Example 3 (Synthesis of flame retardant, i.e., epoxy compound (B)) 859 parts of the polycarbonate (a) obtained in Reference Example 1 was added to the reaction product (b) of Reference Example 2 (epoxy equivalent/hydroxyl group equivalent = 2) /1), 0.17 parts of a 10% aqueous solution of tetramethylene ammonium chloride was added, and the temperature was raised to 225°C and held for 3 hours. After the reaction was completed, the solidified product was crushed to obtain yellow granules. This item (A) has a melting point of 170℃ and an epoxy equivalent of 2900
It was confirmed by IR spectrum that the main product had the following structure. Similarly, the flame retardants (b), (c), (d) shown in Table-1,
I got (e).

[Table] Example 1 100 parts of PBT with an intrinsic viscosity [η] of 0.8 d/g, 36 parts of the flame retardant (A) obtained in Reference Example 3, 4 parts of antimony trioxide, and a carbon fiber treated with an aminosilane coupling agent. Tangled strand type glass fiber 60
parts were uniformly premixed. heated to 230-250℃
The premix was supplied to an extruder with a 40 mm diameter vent, and after being plasticized and kneaded, it was cooled to obtain pellets. Test molded products were made from the pellets using a 3-ounce injection molding machine, and mechanical properties, flammability, and thermal stability were evaluated. The results are shown in Table-2. Comparative Examples 1 to 3 Tests were conducted in the same manner as in Example 1 except that flame retardants (i), (g), and (li) shown in Table 1 were used instead of flame retardant (a) in Example 1. A molded article was obtained, and the evaluation results are shown in Table 2. Comparative Example 4 A test molded article was obtained in the same manner as in Example 1 except that 22 parts of decabromo biphenyl ether was used instead of the flame retardant (a) in Example 1, and the evaluation results were It is shown in Table-2.

【table】

[Table] As is clear from the evaluation results in Table 2, the composition of the present invention was found to have excellent performance in all physical properties and was less likely to be colored in a high-temperature atmosphere. On the other hand, when the flame retardant (A) was used as in Comparative Example 1, the mechanical properties were significantly lowered and significant coloring occurred in a high temperature atmosphere, making it of no practical value. When flame retardant (B) was used as in Comparative Example 2, a decrease in mechanical properties and coloration were observed in a high temperature atmosphere. When a flame retardant (B) having a melting point of 100° C. or lower was used as in Comparative Example 3, it was difficult to feed the flame retardant to the extruder, and the mechanical properties were significantly deteriorated. Further, when decabromo biphenyl ether was used as in Comparative Example 4, the mechanical properties deteriorated and bleeding was severe, making it practically useless. Thus, by using the reaction mixture of polycarbonate and halogenated epoxy resin as a flame retardant in the composition of the present invention, a composition with excellent mechanical properties, flame retardant, and thermal stability can be obtained. Examples 2 to 9 PBT, PET, or a polyester urethane obtained by the reaction of PBT and isocyanate as the polyester, and sodium pyroantimonate or tin oxide as the flame retardant additive were used in the proportions shown in Table 3, Pellets were obtained in the same manner as in Example 1, and then test molded products were prepared and their physical properties were tested. The results are shown in Table-3. Comparative Example 5 Test molded product obtained by carrying out the same procedure as in Example 1 using the flame retardant (d) obtained in the same manner as in Reference Example 3 and having a molar ratio of (a)/(b) of 5/1. The results are shown in Table 3.

[Table] As is clear from the results in Table 3, the molded products of Examples 2 to 9 according to the present invention all exhibit excellent mechanical properties, flame retardance, and thermal stability, but in the case of Comparative Example 5, , Coloring of the test molded product was observed, and the coloration was significant in the high temperature atmosphere.

Claims (1)

[Claims] 1 Terephthalic acid or its ester and carbon number is 2
100 parts by weight of a thermoplastic polyester (A) synthesized from glycol of ~4, halogenated bisphenol A or/and a polymerization degree of 2 having a hydroxyl group at the terminal synthesized from bisphenol A and phosgene.
~10 polycarbonate (a) and an epoxy resin (b) with a degree of polymerization of 5 or less synthesized from halogenated bisphenol A or/and bisphenol A and epichlorohydrin or β-methylepichlorohydrin, with the epoxy group of (b) Equivalent/(a) hydroxyl group equivalent≧
Epoxy compound (B) formed by reacting at a ratio of 2 to 50
A flame-retardant resin composition comprising 0.1 to 20 parts by weight of an inorganic flame retardant aid (C) and 0 to 150 parts by weight of a reinforcing filler (D).