JPS6241967B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flame-retardant non-bleed thermoplastic resin composition. More specifically, the present invention relates to a flame-retardant thermoplastic resin composition that has excellent heat resistance, a flame retardant that does not migrate to the surface of a molded article at high temperatures (referred to as bleed), and high mechanical strength. Terephthalic acid or its ester and carbon number is 2~
Thermoplastic polyesters (hereinafter abbreviated as PEs) formed from glycol 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 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 the electrical and communication fields. do not have. Therefore PEs
For the purpose of imparting flame retardancy to the flame retardant, this can be achieved by adding and mixing organic halogen compounds such as hexabromobenzene and decabromo biphenyl ether, or by using flame retardant aids such as inorganic compounds such as antimony trioxide. was. 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 inventors have completed the present invention as a result of extensive research into a flame-retardant PEs composition that improves the bleed of the flame retardant, has excellent heat resistance, and has high mechanical strength. That is, the present invention uses 100 parts by weight of a polyester consisting of terephthalic acid or its alkyl ester and glycol having 2 to 4 carbon atoms, tetrabromobisphenol A (hereinafter abbreviated as TBA), a polyhydric alcohol, and epichlorohydrin or β-methylepichlorohydrin. Brominated epoxy resin formed by
(a) and a polycarbonate (b) having an average degree of polymerization of up to 20 and having a hydroxyl group synthesized from tetrabromobisphenol A or/and bisphenol A and phosgene in the ratio of epoxy group equivalent of (a)/hydroxyl group of (b). Equivalent ≧
Modified epoxy compound (B) formed by reacting at a ratio of 2 to 3
50 parts by weight, 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). The brominated epoxy resin (a), which is one of the raw material components of the flame retardant, preferably has the following structure. Z; H or CH ₃ R; residue l of polyhydric alcohol excluding the terminal OH group; 1 to 10 m; 1 to 10 Polycarbonate (b), which is the other raw material component, is shown by the structure below. Preferably. P; 1-10 n; 1-4 X; Br or H The above compounds (a) or (b) in which X is Br can each be used alone as a flame retardant, but do not exhibit sufficient effects. In other words, when (a) or (b) is used alone in PEs, a compound with no flame retardant bleed can be obtained, but when exposed to high temperatures of 100°C or higher, the white color changes to yellow or even brown. death,
Not only does it have no practical value in terms of appearance, but also its mechanical strength is significantly lower than when no flame retardant is added. Epoxy resin (a) and polycarbonate (b) of the present invention
It has surprisingly been found that the above drawbacks can be improved by using a flame retardant prepared by reacting epoxy equivalent of (a)/hydroxyl equivalent of (b) ≧2. That is, the flame retardant has significantly improved heat resistance and less thermal discoloration during molding. Furthermore, molded products obtained using the composition of the present invention exhibit very little thermal coloring at high temperatures;
The mechanical strength also shows a very small decrease in toughness compared to those that do not contain flame retardants. Furthermore,
The flame retardant of the present invention has a melting point higher than 100°C, has excellent compounding properties, has a high molecular weight, and has good compatibility with PEs, so it does not bleed onto the surface of molded products. Next, epoxy resin (a) is usually synthesized by the following method. Generally, it can be easily obtained, for example, by heating tetrabromobisphenol A diglycidyl ether, a diglycidyl ether of a polyhydric alcohol, and tetrabromobisphenol A to 80 to 250°C in the presence of a catalyst. Moreover, the polycarbonate (b) used in the present invention is usually synthesized by the following method. For example, in the presence of an inert organic solvent and amines, a halogenated aromatic dihydroxy compound dissolved in an alkaline aqueous solution is reacted with phosgene while adjusting the pH to 10 to 11. It is obtained by hydrolyzing the formate group with aqueous ammonia and aqueous alkaline solution. Further, the reaction between (a) and (b) is usually carried out as follows. For example, tetrabromobisphenol A diglycidether, diglycidether of a polyhydric alcohol, and tetrabromobisphenol A are mixed at 80 to 250°C in a ratio of 1 equivalent of hydroxyl group to 1 equivalent of epoxy group using tetramethylammonium chloride as a catalyst. The reaction is carried out by reacting with (a) to obtain (a), and then adding and reacting with (b) an aromatic polybonate having a low degree of polymerization having hydroxyl groups at both ends. Here, the quantitative ratio of (a) and (b) is the epoxy equivalent of (a) and the hydroxyl equivalent of (b) ≧2, and if the ratio is less than 2, the viscosity of the melt reaction system will become abnormal. The reaction temperature becomes high, making it difficult to continue the reaction, and also having the disadvantage of poor heat coloring resistance. In addition, it is preferable that such a ratio does not exceed 10; if it exceeds 10, the amount of reaction of (a) will be small and the desired effect will not be exhibited, which is not preferable.
More preferably it is 2-7. Polyhydric alcohols used in the present invention include ethylene glycol, 1,2- or 1,3-propylene glycol, 1,2-, 1,3- or 1,4-butanediol, pentanediol, neopentyl Glycol, 1,6-hexane glycol, hepetanediol, octanediol, nonanediol, decanediol, diethylene glycol, dipropylene glycol, triethylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, Glycol compounds such as polyoxytetramethylene glycol and hydrogenated bisphenol A, and polyether polyols are preferred. The amount of the flame retardant of the present invention, that is, the modified epoxy compound (B) is 3 to 100 parts by weight (hereinafter abbreviated as parts) of PEs.
There are 50 copies. If the amount is less than 3 parts, flame retardancy will not be sufficient, and if it exceeds 50 parts, the physical properties of PEs will be significantly reduced. The flame retardant effect depends on the absolute amount of halogen in the flame retardant. Therefore, it is appropriate to use 1 to 30 parts of halogen atoms 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 dl/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 oxyphenylbropane. In addition, PEs can contain up to 40% by weight of polyolefins, polstyrene, 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, saturated polyesters such as polyurethane, and PPO. Furthermore,
Low molecular weight PEs with a hydroxyl group at the end
Polyester polyurethane obtained by increasing the molecular weight of ([η]: 0.15 to 0.5 dl/g) with a polyfunctional isocyanate can also be used. The flame retardant aid in the present invention is preferably an inorganic compound, such as antimony trioxide, antimony tetroxide, antimony pentoxide, sodium 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 retardance will be poor, and if it exceeds 20 parts, the strength of the composition will be reduced. The evaluation of the flammability of the composition in the present invention is determined in accordance with the American Underwriters Laboratories standard Subdigest 94 (UL94). 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. The main component is methane gas as a fire source.
Using 1000 BTU gas, adjust the height of the blue flame without yellow chips to 3/4" using a burner with an internal diameter of 3/8" and a length of 4". The length of the specimen is vertical. Fix it so that the distance between the bottom edge of the specimen and the top edge of the burner is 3/8". Remove the indirect flame from the specimen for 10 seconds and record the subsequent burning time of the specimen (first burning time). Then, as soon as the fire is extinguished, an indirect flame is ignited again for 10 seconds, and the second burning time is recorded after the flame is removed. After the second combustion, record the time during which the specimen emits a red afterglow (afterglow time). Also, observe whether the molten part of the sample falls downward during the flame contact or the subsequent combustion time and afterglow time and ignites the cotton placed 305 mm below. When testing 5 specimens, (A) each burn time is within 10 seconds, (B) the total burn time of 10 times is within 50 seconds, (C) afterglow time is within 30 seconds, and (D ) If all the conditions are met, such as not igniting the cotton, it is called "V-O" flammability. If (A) within 30 seconds, (B) within 250 seconds, (C) within 60 seconds, and (D) the cotton does not catch fire, it is called "V-1".
Also, (A) within 30 seconds, (B) within 250 seconds, (C) within 60 seconds, and
(D) When cotton is ignited, it is called "V-2". 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, glass beads, and glass powder. . 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 0.01-10 mm, preferably 0.05-1 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)
- Aminosilanes such as γ-aminopropyldimethoxymethylsilane; epoxies such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. Silane type 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 (b) 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:
2254, a polycarbonate with an average degree of polymerization of about 3. Reference Example 2 (Synthesis of modified epoxy compound (B) as a flame retardant) 720 parts of diglycidyl ether of tetrabromobisphenol A (epoxy equivalent: 360), diglycidyl ether of 1,6-hexanediol (epoxy equivalent: 150) 300 parts and 544 parts of tetrabromobisphenol A (TBA) were placed in a flask and heated to 150°C.
After heating and dissolving, add 10% aqueous solution of tetramethylene ammonium chloride to 300 ppm based on the total raw materials.
(0.47 parts) and gradually raise the temperature to 170-180℃.
Time reacted. When the acid value of the reactant reached 0.1 or less, 469 parts of the brominated polycarbonate with a polymerization degree of 3 synthesized in Reference Example 1 was added, and the mixture was further heated at 190°C for 5
The time reaction proceeded. When the acid value of the reactant reached 0.1, the product was taken out from the flask, solidified by cooling, and then pulverized. This product (a) had a softening point of 117°C and an epoxy equivalent of 1030. Similarly, flame retardants (B), (C), (D), and (E) shown in Table 1
I got it.

[Table] Example 1 Intrinsic viscosity [η] of 0.8 dl/g (measured at 30°C by dissolving PBT in a 6:4 mixed solvent of phenol and tetrachloroethane), 100 parts, obtained in Reference Example 2. 30 parts of the flame retardant (a) obtained above, 10 parts of antimony trioxide, and 60 parts of chopped strand type glass fiber treated with an aminosilane coupling agent were uniformly premixed. This was heated to 250℃ in advance.
The mixture was supplied to a mmφ vented extruder, plasticized, kneaded, and cooled to obtain pellets. Test pieces were prepared from the pellets using a 3-ounce injection molding machine, and mechanical strength, flammability, heat resistance, and flame retardant bleedability were evaluated. The results are shown in Table 2. Comparative Examples 1-2 In Example 1, decabromo biphenyl ether or a flame retardant (e) was used instead of the flame retardant (a). The results are shown in Table 2. In addition, the decrease in strength is very large compared to that listed in Table 2 that does not contain a flame retardant (Comparative Example 3). Examples 2 to 5 As PEs, PBT, PBT urethane (OHV=
17.5, AN=0.45, 100 parts of low molecular weight PBT with almost all hydroxyl groups at both ends, and 5.6 parts of diphenylmethane-4,4'-diisocyanate were mixed at 250℃ for 5 minutes.
Using the same method as in Example 1, using (a), (b), (c), or (d) obtained in the reference example as a flame retardant, and using the blending ratios shown in Table 2, respectively. Pellets were prepared and their physical properties were evaluated. The results are shown in Table 2.

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【table】

Claims (1)

[Claims] 1 Polyester consisting of terephthalic acid or its alkyl ester and glycol having 2 to 4 carbon atoms
(A) 100 parts by weight, tetrabromobisphenol A,
Polyhydric alcohol and epichlorohydrin or β
- Brominated epoxy resin (a) formed from methyl epichlorohydrin, and polycarbonate (b) having an average degree of polymerization of up to 20 and having hydroxyl groups synthesized from tetrabromobisphenol A or/and bisphenol A and phosgene ( Epoxy group equivalent of a)/
3 to 50 parts by weight of a modified epoxy compound (B) obtained by reacting the hydroxyl equivalent of (b) at a ratio of ≧2, an inorganic flame retardant aid (C)
A non-bleed flame retardant resin composition comprising 0.1 to 20 parts by weight and 0 to 150 parts by weight of a reinforcing filler (D).