Abstract: The invention provides biodegradable vinyl ester copolymers of one or more monomers selected from the group of vinyl esters of unbranched or branched alkylcarboxylic acids having from 1 to 18 carbon atoms, which contain from 0.1 to 40% by weight, based on the total weight of the copolymer, of one or more cyclic ketene acetals selected from the group consisting of 2-methylene-1,3-dioxepane, 2-methylene-1,3-dioxolane, 2-methylene-1,3-dioxane and have a molecular weight>50,000.

Abstract: A process for polymerizing polar compounds which have a C.dbd.C double bond in an .alpha.-position relative to a carbonyl or nitrile group, such as acrylic acid derivatives, which comprises polymerizing the polar compounds in the presence of organometallic compounds of silicon, germanium or tin as initiators together with a nucleophilic or electrophilic catalyst at temperatures in the range of from -100.degree. C. to +100.degree. C.

Abstract: A process for improving the adhesion of polymeric substances containing organic groups or composed of such groups to the surfaces of alkaline earth metal carbonates, which comprises applying an organic aprotic solvent solution containing at least one organosilicon compound having fluorine bonded directly to silicon and an average of not more than 1.8 SiC-bonded organic radicals per silicon atom to the surface of alkaline earth metal carbonates and removing the solvent before a polymeric substance containing organic groups is applied to the pretreated alkaline earth metal carbonate surface.

Abstract: Organosilicon compounds containing SiC-bonded biuret groups are prepared by (I) adding a silane containing 1 or 2 silicon atoms per molecule and an SiC-bonded organic radical having at least one basic ##STR1## group and at least one SiOC-bonded aliphatic radical per molecule to a monoisocyanate or a diisocycanate at a temperature up to 125.degree. C. and (II) maintaining the temperature at 110.degree. C. to 125.degree. C. for at least two minutes. In an alternate procedure the silane and mono- or diisocyanate may be heated to a temperature in the range of from 110.degree. C. up to 200.degree. C. for at least two minutes, after or while adding additional monoisocyanate or diisocyanate.The resultant silicon compounds are used in the preparation of polyurethanes and as additives to lacquers.

Abstract: Organosilicon compounds containing SiC-bonded biuret groups are prepared by (I) adding a silane containing 1 or 2 silicon atoms per molecule and an SiC-bonded organic radical having at least one basic ##STR1## group and at least one SiOC-bonded aliphatic radical per molecule to a monoisocyanate or a diisocyanate at a temperature up to 125.degree. C. and (II) maintaining the temperature at 110.degree. C. to 125.degree. C. for at least two minutes. In an alternate procedure the silane and mono- or diisocyanate may be heated to a temperature in the range of from 110.degree. C. up to 200.degree. C. for at least two minutes, after or while adding additional monoisocyanate or diisocyanate.The resultant silicon compounds are used in the preparation of polyurethanes and as additives to lacquers.