Abstract: A resin-like product having a degree of hydrolysis of 50 to 70 mole percent is obtained by selective alcoholysis of a vinyl ester copolymer, if desired in the form of a mixture with a vinyl ester homopolymer. The starting material employed is preferably a vinyl acetate/crotonic acid copolymer. The resin is suitable for use as a hot-melt adhesive which forms coherent films capable of being activated by water or water vapor.

Abstract: A label essentially comprises a top layer which can be printed and/or inscribed and a water-soluble adhesive layer. The adhesive layer can also be protected by a covering layer. The top layer is formed from polyvinyl alcohol which is preferably insoluble in cold water but soluble in hot water. The adhesive layer comprises a synthetic adhesive which is soluble in water and represents, in particular, a contact adhesive or permanent adhesive. The label is resistant to the action of cold water but is soluble in hot water, and is suitable for labeling containers with a smooth surface.

Abstract: When polyvinyl alcohol and vinyl acetate/ethylene copolymers are acetalized in an acid aqueous medium in the presence of a wetting agent, an open-pore solid foam is formed, if the reaction mixture contains gas bubbles. These gas bubbles are produced, in particular, by stirring in air. The molded articles obtained are porous, and the pores are uniformly distributed. The dried molded article absorbs many times its weight of water. It is employed as a sponge for household use and in industry.

Abstract: With polybasic inorganic acids, for example boric acid, polyvinyl alcohol forms complex compounds, which, in the form of a gel, are suitable as adhesives. PVAL complex compounds are prepared in simple manner by subjecting to alcoholysis a polyvinyl ester in the presence of an organic boric acid derivative complexing agent. The reaction is carried out in alcoholic solution and the complexing agent should be soluble in alcohol. As starting material polyvinyl acetate is preferred, and methanol is preferred as alcohol. The PVAL complex compounds prepared in this way are used, inter alia, as binders and thickening agents for coating substances.

Abstract: The acetalization of polyvinyl alcohol in an acidic aqueous medium in the presence of a wetting agent yields an open-cell, solid foam when the reaction medium contains gas bubbles which are preferably produced by stirring air into the reaction mixture. By carrying out the acetalization in the presence of a nucleic acid a porous shaped article is obtained in which the cells are uniformly distributed. The dried shaped article absorbs a multiple of its weight of water. It can be used for household and industrial purposes.