Photodegradable polyolefin compsns. esp. for mulch film

摘要

A compsn. comprising at least one polyolefin and, per 100 pts.wt. of the polyolein, (a) 0.001 - 0.02 pts.wt. Fe in the form of at least one ionic salt of Fe, (b) 0.001 - 0.1 pts.wt. S in the form of sulphur and/or at least one dialkyl sulphide, of at least one silicate, opt. together with (e) 0.2 - 2 pts.wt. of at least one Cu phthalocyanine cpd. The polyolefin is eg. a homopolymer of ethylene, propylene or 1-butene, a copolymer of these olefins, or copolymers of one of the olefins with copolymerisable monomers such as vinyl monomers, acrylic monomers, CO and SO2, and copolymers of propylene and ethylene contg. a high proportion of propylene units. (a) is eg. ferric naphthenate, ferric stearates, ferric salts of 2-22C fatty acids or ferric salicylate. (b) is eg. flowers of sulphur or a prod. of formula R-An-R' in which R and R' (same or different) = 1-20C hydrocarbon radicals and n = 4-10. (c) ispref. Fe2O3 which is essentially anhydrous and in the gamma-crystalloagraphic form. (d) is eg. talc, kaolinite, wollastonite or ultramarine blue. The silicate pref. has a particle size of 1-5 micrometres.