| 摘要 |
<p>A composition comprises a high molecular weight oxymethylene polymer and a stabilizing system comprising a first compound which is either an ester of formula S(-R-COOR1)2 where R is an alkylene radical and R1 an alkyl radical, or a metal dialkyldithio phosphate of formula <FORM:1031709/C3/1> where R11 is alkyl, M metal and x a whole number equal to the valency of M and a second compound from the group consisting of (i) 2 - hydroxy - benzophenone or substituted derivatives thereof, (ii) aromatic esters of hydroxy aromatic acids, and (iii) 2-(21-hydroxyaryl) benzotriazole or substituted derivatives thereof. Specified first compounds are zinc dinonyl dithiophosphate, and dilauryl thiodipropionate while other compounds specified are 2 - hydroxy - 41 - n - octyloxy benzophenone, 2 - (21 - hydroxy - 51 - alkyl - phenyl) benzotriazole and p-octylphenyl salicylate.</p> |
