| 摘要 |
Saturated and soluble solid ethylene polymerization products, e.g. the surface of films and coatings, are cured by incorporating therewith a curing agent by subjecting the polymerization product or articles prepared therefrom to the action of a solution of the curing agent in a non-solvent for the polymerization product at the temperature employed, and then heating above 40 DEG C., preferably between 70 DEG and 250 DEG C. Specified ethylene polymerization products are polyethylene and interpolymers of ethylene with at least one other organic compound containing polymer-producing unsaturation, e.g. carbon monoxide, acrylic acid esters and nitrile, alkacrylic acids, esters and nitriles, vinyl acetate, propionate and chloride, vinylidene halides and maleic and fumaric acids and derivatives thereof. The curing agents are capable of generating free radicals below 200 DEG C. when heated, specified are benzoyl, lauroyl, diethyl, ditertiary butyl and diisopropyl peroxides, hydroxy-methyl, tertiary butyl and ethyl hydroperoxides, oxygen, aceto-, benzo-, phthalic and succinic mono-peracids, ethyl percamphorate and perbenzoate, tert.-butyl perbenzoate, chloramines B and T, dichloramine T, lead tetraethyl, lead diethyl dibromide, triethylamine oxide, hydrazine hydrate, hydrochloride and sebacate, dibenzoyl hydrazine, diphenyl ketazine and aldazines. The preferred solvents have a swelling action on the polymer at their boiling points or lower temperatures, suitable solvents are given in the Trans. Faraday Soc., v. XLII, parts 1 and 2, 1946, p. 22, xylene being preferred. The polymerization products may contain fillers, pigments and plasticizers, e.g. calcium carbonate, iron oxide and crown clay. Preferably, the heating step is carried out under superatmospheric pressure and by contact with a hot metal surface, e.g. a mould or press. The invention may be applied to the curing of preformed articles, e.g. mouldings, coatings, e.g. extruded on wires, films and fibres. Specification 597,833 is referred to.
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