Abstract: The invention relates to the use of a polymer network comprising a poly(meth) acrylate which is linked by means of oligomer chains which contain chemically bound ethylene oxide units as hydratable groups, the ethylene oxide units being present in the form of oligomer blocks containing 5/14 200 ethylene oxide units, for coating and/or impregnating a substrate or for manufacturing products such as eye lenses and matrices for immobilizing and/or the regulated release of active substances. The polymer network has improved mechanical properties and a desirable permeability to water or water vapour.

Abstract: A solid substrate, which contains or consists of a biologically or chemically active substance, is coated with coating material containing at least one polymerizable crosslinkable polyfunctional acrylic or methacrylic compound whereafter the coating material is subjected to polymerization substantially in the absence of non-polymerizable components to form a network coating of polymer on the surface of the solid substrate. This coating permits either the controlled release of active substance from the coated substrate or the controlled access of material reacting with said active substance into the coated substrate and the controlled release of the resulting reaction products from the coated substrate.

Abstract: A process is described for the removal of halogen residues from a reaction mixture containing 3,5-xylenol and halogen residues, produced via the heating of isophorone at a temperature of about 450.degree. C. to about 650.degree. C. in the presence of a homogeneous halogen-containing catalyst, said removal being accomplished by contacting the reaction mixture with a metal selected from the group consisting of zinc, iron, magnesium, cadmium, cobalt and nickel.