| abstract |
This invention relates to flame retardants for synthetic resin compositions. It is a composition comprising: (A) about 30 to about 70 wt. percent of a synthetic resin which is, (1) about 30 to about 70 wt. percent of a first resin which is polypropylene, polycarbonate, polyphenylene oxide or polystyrene, or copolymers of polystyrene and maleic anhydride, and (2) about 30 to about 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) about 20 to about 45 wt. percent of melamine pyrophosphate, or (2) about 15 to about 30 wt. percent of melamine pyrophosphate and up to about 10 wt. percent charring catalyst; or (3) about 15 to about 30 wt. percent of melamine pyrophosphate, up to about 10 wt. percent charring catalyst, and up to about 10 wt. percent of a char former, or (4) about 20 to about 40 wt. percent melamine pyrophosphate and up to about 5 wt. percent zinc borate, and (C) up to about 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. |