Stable aq elastomer latices

摘要

Stable aqueous elastomer dispersions in which >80% of the dispersed particles are smaller than 1.2 mu, are made by emulsifying in water an organic solvent solution of the elastomer in a solvent system consisting of a solvent for the elastomer and 7-75 wt. % of a non-solvent, using a volume ratio of elastomer soln.: water of 0.5:1 to 2:1, with about 0.5-2.5 g emulsifier per 100 ml polymer cement, followed by removal of the solvent-non-solvent system. Latices can be made of elastomers which cannot normally be made by emulsion polymerisation, such as poly(epichlorhydrin), polydienes, butyl rubber, ethylene-propylene copolymers, ethylene-propylenediene terpolymers and polurethanes. Generally a polymer cement is made contg. 5-25% solids, with a viscosity of 500-2000 cPs. and this is emulsified with water using an emulsifier such as dodecylbenzene sulphonate in an appts. such as an Eppenbach rotary homogeniser. The solvent system is removed e.g. under vacuum in a Rince Evaporator. The resulting latices are useful as binders for paper, non-woven fabrics and textiles.