JPS6228175B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a reinforced, fire-resistant polybutylene terephthalate resin composition that has reduced melt-dripping properties during combustion. In recent years, reinforced polybutylene terephthalate has been used in a wide range of fields such as electrical parts, automobile parts, and mechanical parts due to its excellent moldability and excellent mechanical and electrical performance. However, since the reinforced polybutylene terephthalate resin is flame retardant, various attempts have been made to make it flame retardant in response to flame retardant regulations that have recently become stricter. A typical example is shown in Japanese Patent Publication No. 48-12413, but if a flame-retardant composition is determined by focusing only on flammability, it will not be possible to prevent the resin from melting and dripping during combustion. In most cases, there is no. Several methods have already been proposed to improve the drawbacks of molten dripping.
JP-A No. 47-11281 describes a method of using an auxiliary reinforcing agent in addition to the main reinforcing agent such as glass fiber, and JP-A No. 47-42942 describes a method of using tetrafluoroethylene powder in addition to glass fiber. JP-A No. 48-32949 describes a method of adding fumed colloidal silica to glass fibers, but in both cases, fibrous inorganic compounds and fine particles are not added. This physical interaction prevents melt dripping. On the other hand, as another method, JP-A-50-61448 discloses a combination system of a cellulose compound and a polyphosphorus compound, but the minimum combined addition rate for flame retardant effect is 20
% by weight or more, requiring a fairly high concentration of addition, and the flame retardant effect can only be achieved when the thickness at which the flame retardant effect is as thick as 1/8" is achieved. As a result of intensive studies on preventing liquid droplets during combustion, we found that a reinforced flame-retardant polybutylene terephthalate resin obtained by combining a brominated aromatic compound with a chlorinated alicyclic compound and antimony trioxide is capable of preventing molten droplets during combustion. It has been found that the formation of polybutylene terephthalate resin is significantly reduced.That is, the present invention has been developed by combining the bromine atom in the brominated aromatic compound, the chlorine atom in the chlorinated alicyclic compound, and the antimony atom in the antimony trioxide into polybutylene terephthalate resin. Weight ratio 0.7~1.3:0.4~
2.0:1, containing these three flame retardants in a total amount of 14% by weight or more, and further containing 10 to 50% by weight of a reinforcing agent, which suppresses the formation of molten droplets during combustion. The present invention relates to a polybutylene terephthalate resin composition. Here, the polybutylene terephthalate resin includes a polybutylene terephthalate homopolymer, a polybutylene terephthalate copolymer mainly consisting of tetramethylene terephthalate and having less than 40 mol% of copolymerized units. The copolymerization components of the copolymer include ethylene glycol, propylene glycol, decamethylene glycol, neopentyl glycol, and diol components.
There are aliphatic, aromatic, and alicyclic glycols such as γ-xylene glycol, cyclohexanediol, and cyclohexane methanol, and dicarboxylic acid components include isophthalic acid, phthalic acid, terephthalic acid, p-oxybenzoic acid, and m-oxybenzoic acid. , aromatic, aliphatic, and alicyclic dicarboxylic acids such as naphthalene dicarboxylic acid, oxalic acid, adipic acid, sebacic acid, and cyclohexane dicarboxylic acid. Furthermore, blends of polybutylene terephthalate and 40% by weight or less of other thermoplastic polymers can also be applied. Examples of the thermoplastic polymer as a blend component include the above copolymers, polyethylene terephthalate, polycarbonate, nylon 6, nylon 66, nylon 12, nylon 11, polymethylene oxide, polypropylene, polyethylene, polystyrene, ABS resin, and the like. As the brominated aromatic compound, the general formula (),
There are compounds shown by () and (). where R ₁ is oxygen, sulfur, sulfur dioxide, alkylene, oxyalkylene or phosphonate group, R ₂ is hydrogen, methyl or acetate group, and X is hydrogen, bromine group, and at least one, preferably Everything is bromine. Examples of these compounds include decabrom diphenyl ether, decabrom diphenyl sulfide,
Examples include decabromidiphenyl sulfoxide, decabromidiphenyl, and tetrabromobisphenol A. As the chlorinated alicyclic compound, the general formula (),
There is a compound shown by Examples of these compounds include perchloropentacyclodecane. Further reinforcing agents that can be used include glass fiber,
Examples include carbon fiber, wollastonite (CaSiO ₃ ), kaolin (Al ₂ O ₃ .2SiO ₂ .2H ₂ O), calcium carbonate (CaCO ₃ ), and glass fiber is particularly preferred. In addition to these reinforcing agents, various pigments, lubricants, stabilizers, mold release agents, etc. can be appropriately blended. Hereinafter, the present invention will be specifically explained with reference to Examples. Example 1 Additives were blended with the composition shown in Table 1 to polybutylene terephthalate having a melting point of 225°C and an intrinsic viscosity (phenol/tetrachloroethane = 6/4, 30°C) of 0.80, and the mixture was extruded and pelletized using an extruder. Next, the obtained pellets are dried under reduced pressure and then processed into UL using an injection molding machine.
−94 combustion test pieces and tensile test pieces were formed, respectively.
The results of the UL-94 combustion test and ASTM D-638 tensile test are shown.

[Table] The combination of decabromodiphenyl ether and antimony trioxide or the combination of perchloropentacyclodecane and antimony trioxide has poor flammability. Of course, if the addition rate of these two types of flame retardants is increased, the flammability will decrease. By using the three in combination: decabromodiphenyl ether, perchlorpentacyclodecane, and antimony trioxide, there is a composition range in which not only the flammability but also the melting and dripping of the resin during combustion can be significantly reduced, as shown in the examples. The mechanical performance in terms of tensile strength is also that of ordinary glass-reinforced polybutylene terephthalate (1200Kg/
^cm2 ) and no color loss. Example 2 Additives were blended with the composition shown in Table 2 to polybutylene terephthalate having a melting point of 225°C and an intrinsic viscosity (phenol/tetrachloroethane = 6/4, 30°C) of 0.80, and the mixture was extruded and pelletized using an extruder. Next, the obtained pellets are dried under reduced pressure and then processed into UL using an injection molding machine.
-94 combustion test pieces and tensile test pieces were molded and tested in the same manner as in Example 1.

[Table] When the addition rate of decabromodiphenyl increases, the melt dripping during combustion increases, and when the addition rate of perchloropentacyclodecane increases, the dripping during combustion decreases, but the mechanical strength decreases. It can be seen that the appropriate composition of decabromodiphenyl, perchloropentacyclodecane and antimony trioxide is within the scope of the claims. Example 3 Additives were blended with the composition shown in Table 3 to polybutylene terephthalate with a melting point of 225°C and an intrinsic viscosity (phenol/tetrachloroethane = 6/4, 30°C) of 0.80, and the mixture was extruded and pelletized using an extruder. After drying the pellets under reduced pressure, a UL-94 combustion test piece was molded using an injection molding machine, and a UL-94 combustion test was conducted.

[Table] From Example 3 and Comparative Example 3, it was found that the resin composition had remarkable flame retardancy only when a brominated aromatic compound, a chlorinated alicyclic compound, and antimony trioxide were used together. I understand.

Claims (1)

[Claims] 1 The weight ratio of the bromine atom in the bromine-based aromatic compound, the chlorine atom in the chlorine-based alicyclic compound, and the antimony atom in the antimony trioxide is set to 0.7 to 1.3:0.4 to 2.0:1 in the polybutylene terephthalate resin, It is characterized by containing these three flame retardants in a total amount of 14% by weight or more, and further containing 10 to 50% by weight of a reinforcing agent, and the chlorinated alicyclic compound is perchloropentacyclodecane or A reinforced flame-retardant polybutylene terephthalate resin composition characterized by being a modified product thereof.