| abstract |
This invention relates to flame retardants for synthetic resin compositions. It is a composition comprising: (A) 30 to 70 wt. percent of a synthetic resin which is, (1) 30 to 70 wt. percent of a first resin which is polypropylene, polycarbonate, polyphenylene oxide or polystyrene, or copolymers of polystyrene and maleic anhydride, and (2) 30 to 70 wt. percent of a second resin which is polyethylene terephthalate, or nylon 6,6, or blends or mixtures thereof, wherein the wt. percentages of (A)(1) and (A)(2) total 100 % as between (A)(1) and (A)(2); (B) a flame retardant selected from the group consisting of (1) 20 to 45 wt. percent of melamine pyrophosphate, or (2) 15 to 30 wt. percent of melamine pyrophosphate and up to 10 wt. percent charring catalyst; or (3) 15 to 30 wt. percent of melamine pyrophosphate, up to 10 wt. percent charring catalyst, and up to 10 wt. percent of a char former, or (4) 20 to 40 wt. percent melamine pyrophosphate and up to 5 wt. percent zinc borate, and (C) up to 40 wt. percent reinforcing agent; wherein all percents by wt. are based on the total wt. of (A)+(B)+(C) except for the relationship between (A)(1) and (A)(2) which is set forth above. |