GB645088A - Emulsions of ethylene polymers and interpolymers - Google Patents

Abstract

Aqueous emulsions of ethylene polymers are prepared by polymerizing ethylene, alone or with interpolymerizing constituents, at a temperature between 50 DEG and 1400 DEG C., and a pressure above 200 atmospheres, in the presence of water, a water-soluble salt of a carboxylic acid polymer of molecular weight above 300, and an organic sulphonic acid or derivative thereof, preferably sodium oleo-p-anisidide sulphonate. The water-soluble salt of a carboxylic acid polymer may be an ammonium salt of polymethacrylic acid, a sodium or ammonium salt of a saponified ethylene/maleic anhydride interpolymer or an alkalimetal salt of a glycollic acid ether of cellulose or of polyvinyl alcohol. The reaction may be carried out continuously by introducing the reactants into a reaction vessel maintained at the required temperature and pressure and continuously withdrawing the emulsion and unconverted ethylene. Interpolymerizing constituents mentioned are vinyl acetate, vinylidene chloride, carbon monoxide and formaldehyde. The process may be carried out in the presence of hydrogen which modifies the properties of the polymer. An ethylene polymerization catalyst such as oxygen, a peroxy compound, particularly an alkyl peroxide, or an azo compound may be utilized, and there may also be present an inorganic salt such as sodium sulphate or a small proportion of an inert organic solvent such as benzene. The emulsions obtained may be used for coating or as adhesives for fabrics or for making powdered ethylene polymers and interpolymers by precipitation.