Flame-retardant polycarbonate resin composition and formed article

#The present invention relates to a flame-retardant thermoplastic resin composition. Precisely, the invention relates to a flame-retardant thermoplastic resin composition and its moldings, which do not contain halogen but contain minor additives to exhibit good flame retardancy and have good impact resistance and good thermal stability.

#As having the advantages of impact resistance, heat resistance and good electric properties, polycarbonate resins have many applications in various fields of, for example, OA (office automation) appliances, information and communication appliances, other electric and electronic appliances for industrial use and household use, car parts and building materials. As a rule, polycarbonate resins are self-extinguishable. However, some fields of typically OA appliances, information and communication appliances, and other electric and electronic appliances for industrial use and household use require high flame retardancy, for which are used various flame retardants to improve their flame retardancy.

#For improving the flame retardancy of polycarbonate resins, halogen-containing flame retardants such as bisphenol A halides and halogenated polycarbonate oligomers have been used along with a flame retardation promoter such as antimony oxide, as their flame-retarding ability is good. However, with the recent tendency toward safety living and environmental protection from discarded and incinerated wastes, the market requires flame retardation with non-halogen flame retardants. As non-halogen flame retardants, phosphorus-containing organic flame retardants, especially organic phosphate compounds may be added to polycarbonate resin compositions, for which various methods have been proposed. Such flame retardants, organic phosphate compounds serve also as a plasticizer, and polycarbonate resin compositions containing them exhibit excellent flame retardancy.

#The components shown in Table 1 and Table 2 were blended in the ratio indicated therein (the components (A) and (B) are in terms of % by weight, and the other components are in terms of parts by weight relative to 100 parts by weight of the total of (A) and (B) ), fed into a vented double-screw extruder (TEM35 from Toshiba Kikai), melted and kneaded therein at 260° C., and then pelletized. To all compositions of Examples and Comparative Examples, added were 0.2 parts by weight of Irganox 1076 (from Ciba Specialty Chemicals) and 0.1 parts by weight of Adekastab C (from Asahi Denka Industry) both serving as an antioxidant. The resulting pellets were dried at 120° C. for 12 hours, and then molded into test pieces in a mode of injection molding at 260° C. The mold temperature was 80° C. These test pieces were tested for their properties in various test methods, and their data obtained are given in Table 1 and Table 2.

#The materials used for producing the test samples, and the methods for testing the samples are mentioned below.

#[Details of Constituent Components]