GB1097129A - Polypropylene compositions - Google Patents

Abstract

Propylene polymer compositions comprise crystalline polymer consisting predominantly of polypropylene and 0.001 to 1.0 per cent by weight of the polymer of at least one aromatic mono-sulphonic acid salt of formula (Ar-SO3)n M where Ar is an unsubstituted or alkyl, alkoxy or hydroxy substituted aromatic residue, M is a metal of Group Ia, IIa or IIb of the Periodic Table and n is the valency of the metal. The polymer may be an isotactic polypropylene, crystalline copolymer, block copolymer or graft copolymer with a minor proportion of other olefin, or a mixture of said polypropylene with a minor proportion of polyethylene and/or synthetic rubber. Specified salts are sodium, calcium, barium, zinc and cadmium benzene-sulphonates; potassium, sodium and zinc p-toluenesulphonates; magnesium m-phenol-sulphonate; lithium and calcium p-phenol-sulphonates; sodium naphthalene-2-sulphonate, sodium-2-naphthol-6-sulphonate; sodium 1-naphthol - 4 - sulphonate sodium 2-naphthol- 8 - sulphonate; sodium anthracene - 2 - sulphonate; sodium - 9, 10 - anthraquinone - 1 - sulphonate and sodium 9, 10-anthraquinone-2-sulphonate. The compositions may also comprise stabilizers and pigments, and may be melt moulded into shaped articles, the salt being said to increase the rate of crystallization. Examples describe compositions comprising polypropylene and (1) 2,6-di-t-butyl-p-cresol, dilauryl thiodipropionate and sodium anthracene - 2 - sulphonate, (2) sodium 9,10 - anthraquinone - 2 - sulphonate and (3) 2,6 - di-t-butyl - p - cresol and sodium, cadmium, barium or calcium benzene sulphonate, zinc p-toluene sulphonate, sodium 2-naphthol-6-sulphonate or sodium 9,10-anthraquinone-1-sulphonate; and comprising a polypropylene/ethylene graft polymer and (4) di-t-butyl-p-cresol and sodium benzenesulphonate.