| 摘要 |
A compsn. for chlorinated polymer (partic. PVC) comprises, as a stabilising compsn.: (a) the non-purified prod. of a condensation reaction between an ester and a ketone in the presence of an alkali prod. comprising 10-95(20-80)% of a beta diketone; and (b) a metallic acetylacetonate complex. The ratio of a:b can vary between 50/50 to 1/99. Also claimed are objects moulded from such stabilised compsns.. Pref. the prod. (a) is the solid residue from recrystallisation comprising 20-40% of beta -diketones. The condensn. reaction is as follows: R1COCHR2H+R3COOR4+ACat = R1COCHR2COR3+R4OH -a Acat = a cation amide or hydride; R1 and R3 = aralkyl or alkenyl max. 24C; 7-10C aralkyl, or aryl or cycloaliphatic (less than 14C); R2 = H or alkyl(max. 4C); R4 = 1-4C alkyl, more pref. Me. More pref. the ester is methyl stearate, the ketone is acetophenone, and the alkali is sodiamide. Constituent (a) is pref. solid and of particle size less than 500 mu m (more pref. 200 mu m), and is obtd. from the crude prod. at 20 degrees C, by solvent pptn., cryogenic milling, or spray drying. The constituent (b) is a Ca or Zn complex, and the ratio of a:b is between 20/80 to 1/99. The compsn. also contains 0.5-10 pts. (more pref. 3-8 pts.) of TiO2(as rutile) of particle size 0.1-5 mu m, and may also contain supplementary stabilisers such as a carbonate and/or sulphate of Al or Mg. |
