GB1263484A - Novel elastomers and adhesive compositions containing them - Google Patents

Abstract

1,263,484. Chlorinated olefin/acid copolymers; adhesive compositions. E. I. DU PONT DE NEMOURS & CO. 19 June, 1969 [25 June, 1968], No. 31121/69. Heading C3P. Solvent-soluble elastomers comprise a chlorinated copolymer of an α-olefin and acrylic acid or an α-alkyl derivative thereof having up to 8 carbon atoms, which has a chlorine content of from 15-45% by weight (but excluding chlorinated ethylene-acrylic acid copolymers), the base polymer (i.e. non-chlorinated form) containing from 0À15-0À85 mole per cent of the acid monomer units and having a melt index of 0À1-20. Ethylene is preferred as the α-olefin component; propylene is also useful. The substituted acrylic acid may be α-ethylacrylic or α-propylacrylic acid but methacrylic acid is preferred. The elastomers can be prepared by chlorinating the base polymer, or by copolymerizing the acid monomer with a chloro-olefin such as vinyl chloride. In the example an ethylene-methacrylic acid copolymer is reacted with chlorine in carbon tetrachloride/chloroform using azodiisobutyronitrile as a catalyst for the reaction. The elastomers can be used to form adhesive compositions by dissolving the elastomer in an organic solvent therefor together with sufficient water and an alcohol (C 1 -C 4 ) to prevent a large increase in viscosity. A basic adjuvant (e.g. an amine or metal oxide, hydroxide or salt) capable of reacting with the carboxyl groups of the elastomer may optionally be present; magnesium oxide is a preferred adjuvant. Suitable solvents for the elastomers include hexane, heptane, octane, benzene, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl acetate, methyl acetate and mixtures thereof.