JPS6241257B2 - - 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 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 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, in the present invention, tetrabromobisphenol A (hereinafter referred to as "part") is added to 100 parts by weight (hereinafter referred to as parts) of polyester (i) consisting of terephthalic acid or its alkyl ester and glycol having 2 to 4 carbon atoms.
(abbreviated as TBA), polyhydric alcohol and epichlorohydrin, and contains as well as 3 to 50 parts of addition polymer (ii) having 1 to 10 of each as a flame retardant, metal oxide (iii) 0.1 to 20 parts as a flame retardant aid, and reinforcing material (iv) 0 to 150 parts. A flame retardant resin composition is provided. The flame retardant used in the present invention is a block or random addition polymer consisting of TBA, polyhydric alcohol and epichlorohydrin, (hereinafter referred to as TBA/EP combination) and (hereinafter referred to as alcohol/EP bonds) each having 1 to 10. Examples include those of the following general formula, but are not particularly limited. (However, Z; H or CH ₃ R; residue of polyhydric alcohol excluding the terminal OH group l; 1 to 10 m; 1 to 10) A flame-retardant glass fiber reinforced resin composition consisting of antimony trioxide and antimony trioxide has been reported. However, this
TBA type epoxy resin itself is brittle, so compositions containing it are brittle and lack flexibility and toughness.
Not practical. Furthermore, when a composition containing such a flame retardant is exposed to a high temperature of, for example, 180° C., it becomes colored brown, and its strength is also observed to be lowered, making it inferior in heat resistance. The present inventors have improved these drawbacks and have newly discovered a composition in which the flame retardant does not bleed. This is a flame retardant copolymerized with aliphatic glycol that gives TBA-based epoxy resin flexibility.
That is, it is a polymer obtained by addition polymerization using TBA, polyhydric alcohol, and epichlorohydrin. Since the flame retardant itself is flexible and has a low viscosity when melted, it can be made into a polymer with a fairly high molecular weight and toughness. Therefore, the composition of the present invention using the flame retardant It has excellent mechanical strength without brittleness. Furthermore, the flame retardant copolymerized with a polyhydric alcohol is less likely to eliminate bromine at high temperatures than TBA-based epoxy resins, so it has higher thermal stability. Therefore, the composition of the present invention is recognized to have the advantage that under high temperatures, discoloration yellowing, decrease in strength, etc. are extremely small. The polyhydric alcohol used in the present invention includes:
Ethylene glycol, 1,2- or 1,3-propylene glycol, 1,2-, 1,3- or 1,4-butanediol, pentanediol, neopentyl glycol, 1,6-hexane glycol, Glycol compounds such as heptanediol, octanediol, nonanediol, decanediol, diethylene glycol, dipropylene glycol, triethylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol; Polyether polyols are preferred. The amount of flame retardant used is 3 to 50 parts per 100 parts of PEs. If the amount is less than 3 parts, flame retardancy will not be sufficient, and if it exceeds 50 parts, the physical properties of the composition will be significantly reduced. Since the flame retardant effect depends on the absolute amount of bromine in the flame retardant, the most preferred amount is usually 1 to 25 parts of bromine atoms per 100 parts of PEs. The flame retardant can be synthesized, for example, by the following method. The diglycidyl ether of TBA and a polyhydric alcohol, and if necessary, the diglycidyl ether of TBA, can be easily synthesized by heating to 150 to 180°C in the presence of a catalyst such as tetramethylammonium chloride. The PEs used in the present invention are synthesized from terephthalic acid or its ester, represented by PET and PBT, and glycols having 2 to 4 carbon atoms, and have an intrinsic viscosity [η] (phenol and ethane tetrachloride). (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 as an acid component, such as 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, polyurethane, other saturated polyesters, and PPO. In addition, low molecular weight PEs with a hydroxyl group at the end
Polyester polyurethane obtained by increasing the molecular weight of PEs ([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 a metal oxide, such as antimony trioxide, antimony tetroxide, antimony pentoxide, tin dioxide, zirconium oxide, molybdenum oxide, and the like.
Furthermore, it is also possible to use sodium pyroantimonate and zinc borate in combination. The amount of flame retardant aid used is
0.1 to 20 parts, preferably 1 to 15 parts per 100 parts of PEs
If it is less than 0.1 part, 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 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. 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. In addition, when testing 5 specimens, the evaluation according to the above standards is as follows: (A) Burning time is all within 10 seconds, (B) Total burning time of 10 times is within 50 seconds, (C) Afterglow time is 30 seconds. flammability within seconds and (D) does not ignite the cotton. Also, (A)
Within 30 seconds, (B) within 250 seconds, (C) within 60 seconds, and
When (D) does not ignite cotton, it is called "V-1". Furthermore, when (A) ignites within 30 seconds, (B) within 250 seconds, (C) within 60 seconds, and (D) ignites cotton, it is referred to as "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. For example, 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)-
Aminosilanes such as γ-aminopropyldimethoxymethylsilane; epoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. system 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 Examples 1 to 3 (Synthesis of flame retardant) TBA, diglycidyl ether of polyhydric alcohol, and diglycidyl ether of TBA were placed in a flask according to the compounding ratios shown in Table 1, and after heating and dissolving at 150°C, 10% of tetramethylammonium chloride was added.
Add 300ppm of % aqueous solution to the total raw materials, 170-180
The reaction was carried out at ℃ for 3 to 4 hours, and when the acid value of the reactant became 0.1 or less, the reaction was stopped by cooling. The product was pulverized into fine particles using a pulverizer to obtain flame retardants (A), (B), and (C). The numbers of TBA/EP bonds and alcohol/EP bonds in the molecules of each flame retardant were as follows.

【table】

[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 1. 29 parts of a flame retardant, 6 parts of antimony trioxide, and 58 parts of chopped strand type glass fiber treated with an aminosilane coupling agent were uniformly premixed. This was supplied to a 90 mmφ vented extruder which had been preheated to 230 to 250°C, and after being plasticized and kneaded, it was cooled to obtain pellets. Test specimens were prepared from the pellets using a 3-ounce injection molding machine, and mechanical strength, flammability, thermal stability, and flame retardant bleedability were evaluated. The results are shown in Table 2. Comparative Examples 1-2 In Example 1, the flame retardant (A) was replaced with (D) or decabromo biphenyl ether. The results are shown in Table 2. 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°C.
Using (A), (B), or (C) obtained in the reference example as a flame retardant, pellets were prepared in the same manner as in Example 1 at the mixing ratios shown in Table 2. The physical properties were evaluated. The results are shown in Table 2.

【table】

【table】

Claims (1)

[Claims] 1. Polyester consisting of terephthalic acid or its alkyl ester and glycol having 2 to 4 carbon atoms
(i) 100 parts by weight of tetrabromobisphenol A, polyhydric alcohol, and epichlorohydrin; as well as 3 to 50 parts by weight of an addition polymer (ii) having 1 to 10 of each as a flame retardant, 0.1 to 20 parts by weight of a metal oxide (iii) as a flame retardant aid, and further reinforcing agent (iv) 0 to 50 parts by weight. A flame-retardant resin composition containing 150 parts by weight.