GB924081A - Method of treating expanded sponge material to render it hydrophilic and product thereof - Google Patents

Abstract

Sponges, particularly those of polyurethane, cellulose, rubber, polyvinyl chloride or polyvinyl formal, having improved hydrophilic properties are obtained by soaking the sponge in an aqueous dispersion containing at least 0,1%, preferably 1-2%, by weight of a generally water insoluble or only slightly water soluble non-ionic or cationic surface active agent at 20-85 DEG C. for a time sufficient for the sponge to absorb at least 1%, preferably 5-20%, by weight of the agent, calculated on a dry basis. On removal from the treatment bath, the sponge is wrung out and dried, for example at 130 DEG F. The dispersion of the surface active agent may be facilitated by the use of such solvents as low molecular weight ketones, aliphatic alcohols and aliphatic ethers, a suitable bath comprising 40-95% water and 5-60% methanol. Where the bath comprises such a dispersing solution the sponge is usually treated at the lower part of the temperature range quoted; when only water is present, the upper part of the temperature range is preferred. Suitable surface active agents are fatty alkanolanides, various oxazolines, and ethylene oxide condensates with alkylphenols and fatty alcohols. U.S.A. Specifications 2,085,052, 2,386,995, 2,444,546, 2,444,869 and 2,609,347 are referred to.