| 摘要 |
An additive reducing the yellowing of vinyl chloride polymers, from which As, Cd, Pb, Hg and Th are excluded, to make them environmentally acceptable, consists of (A) >=1 basic inorg. cpd. of Li, Na, K, Mg, Ca, Sr, Ba, Zn, Ti, Al, Zr, or Sn, and (B) for each pt. wt. of (A) 0.01-1 pt. wt. of a diketone deriv. of formula M R-C(=O)-CR'-C(=O)R2 n, (where R is 1-18C hydrocarbon, opt. substd. by Hal, alkoxy or alkylenedioxy; R' is H or R3-C(=O)-; R3 is 1-18C hydrocarbon; R2 is H or R; M is hydrocarbon or Li, Na, K, Mg, Ca, Sr, Ba, Zn, Al or Sb; and n=1-3 and depends on the valency of M). The additives stabilise homopolymers of vinyl chloride and copolymers of vinyl chloride with propylene, ethylene 1-hexene, vinyl acetate, diethyl maleate and diethyl fumerate. They may be applied together with known stabiliser other than those contg. Pb or Ca, used at 0.1-10 pts. wt /100 pts. wt. polymer, including 1,2-epoxides, organotin derivs., organic phosphites, salts of phenols substd. with organic radicals and/or 6-30C monocarboxylic acid salts free from N. The additives are used at 0.02-20 pts. wt. /100 pts. wt. polymer. The additives do not lead to problems of environmental contamination. |
