Abstract: Biologically degradable aqueous dispersions of vinyl ester polymers are provided which have a solids content of 20 to 70% by weight, based on the total weight of the dispersions, and have been prepared by free radical polymerization by the emulsion polymerization process, wherein, in the presence of10 to 50% by weight, based on the monomer phase, of biologically degradable plasticizer and 0.5 to 15.0% by weight, based on the monomer phase, of biologically degradable emulsifier and/or biologically degradable protective colloid,a monomer phase comprisinga) 50 to 100 parts by weight of one or more vinyl esters from the group comprising vinyl esters of unbranched or branched alkylcarboxylic acids having 1 to 15 C atoms,b) 0 to 30 parts by weight of ethylene and/or an ester of (meth)acrylic acid or ethylenically unsaturated dicarboxylic acids from alcohols having 1 to 10 atoms andc) 0 to 20 parts by weight of other mono- or poly-ethylenically unsaturated compounds, is polymerized.

Abstract: The invention relates to a process for the preparation of microencapsulated flakes or powders by drying aqueous mixtures containing (a) one or more water-emulsifiable, non-thermoplastic compounds which have a higher boiling point than water and (b) at least one water-soluble, film-forming polymer, in which the content of component (a) is up to about 95% by weight, based on the dry weight of components (a) and (b), with the proviso that the water-soluble, film-forming polymer has a flocculation point of from 20.degree. to 98.degree. C. or the flocculation point is adjusted to from 20.degree. to 98.degree. C. with the aid of additives, and drying is carried out by thin-layer drying in a temperature range above the flocculation point.

Abstract: The invention relates to water-dispersible or water-soluble polymer powder compositions which can be crosslinked or condensed by acid and comprisesI) one or more pulverulent water-dispersible or water-soluble copolymers which can be crosslinked or condensed by acid,II) one or more pulverulent water-dispersible or water-soluble compounds from the group consisting of alkali metal or ammonium peroxo acid salts, andIII) one or more pulverulent water-dispersible or water-soluble reducing agents.

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: The invention relates to a process for preparing ketene acetals by dehydrohalogenation of 2-haloaldehyde acetals. If the 2-haloaldehyde acetal is open chain, the dehydrohalogenation is carried out in the presence of an alkali metal hydroxide or alkaline earth metal hydroxide and a phase transfer catalyst and/or a secondary or tertiary alcohol or a secondary or tertiary diol. If the 2-haloaldehyde acetals is cyclic, the dehydrohalogenation is carried out in the presence of an alkali metal hydroxide or alkaline earth metal hydroxide and a phase transfer catalyst and with or without a secondary or tertiary alcohol or a secondary or tertiary diol, or carried out in the presence of an alkali metal hydroxide or alkaline earth metal hydroxide and a secondary or tertiary diol. The ketene acetals which can be prepared by the process of the invention serve as intermediates in organic synthesis and are suitable as monomers or comonomers in free radical polymerization for the production of biodegradable plastics.

Abstract: The present invention provides compositions which are based on diorganopolysiloxanes that crosslink to give elastomers containing no toxic curing catalysts, e.g., tin catalysts. These elastomers have a high tensile strength and are suitable for use as coatings.

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: The invention relates to a process for strengthening the adhesion of polymeric substances which contain organic groups or are made up of such groups, or substances containing organic groups which can be crosslinked to form polymers, to surfaces containing an inorganic carbonate, preferably alkaline earth metal carbonates, which comprises applying a solution of a phosphorus compound to the surface containing an inorganic carbonate, in which the phosphorus compound is a phosphorus acid or a phosphorus-containing organosilicon compound having at least one group of the formulaRSiOP.dbd.O,in which R is an SiC-bonded, monovalent, substituted or unsubstituted hydrocarbon radical, and the solvent is an aprotic organic solvent, removing the solvent and thereafter applying the polymeric substance or substance which can be crosslinked to form a polymer to the surface containing the inorganic carbonate.

Abstract: The invention relates to modified poly(organo-organosiloxanes) with comb and/or block structures, which consist of a substantially linear diorganopolysiloxane base with organic polymers based on acrylates arranged in terminal positions and/or along the chain. These block polymers can be prepared by a two-step process. In a first process step, alkenyl trialkylsilylacetates are added to polyorgano-H-siloxanes in the presence of, for example, platinum catalysts and in a second process step, polar compounds, such as acrylates or methacrylates are graft copolymerized onto the polyorganosiloxanes modified with trialkylsilylacetoxyalkyl groups obtained above, in the presence of, for example, nucleophilic catalysts according to the principle of the group-transfer method.

Abstract: The invention relates to an improved process for the polymerization of polar compounds which have a C.dbd.C double bond in the .alpha.-position to a carbonyl, nitrile, sulfone, phosphone or nitro group, such as, for example, acrylic acid derivatives, .alpha.-nitroolefins, vinyl sulfone derivatives and vinyl phosphonic acid esters. The quasi-ionic polymerization is initiated by organometallic compounds of silicon, germanium and tin as initiators together with nucleophilic or electrophilic catalysts, and is carried out at temperatures in the range of from -100.degree. C. to +100.degree. C., in which the initiators are selected from silanes, germanes, stannanes, siloxanes, germoxanes or stannoxanes having at least one metal-bonded allyl or propargyl group, which may be substituted by hydrocarbon groups, per metal atom.

Abstract: Linear low-molecular-weight organo(poly)siloxanes which are monofunctional or difunctional and in which, if difunctional, the two functionalities are present in siloxane units which are chemically different from each other are prepared by reacting an octaorganocyclotetrasiloxane with lithium silanolate in a molar ratio of 0.9:1 to 1.1:1 in an electron-donating, aprotic solvent at a temperature below 50.degree. C., in the absence of water, and thereafter reacting the resultant lithium siloxanolate thus obtained with an organohalosilane.

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: The present invention relates to gypsum powders containing a hydrophobic agent and to water-repellent articles which are prepared from gypsum containing powered hydrophobic agents, in which the hydropohobic agents are prepared by spray-drying a mixture containing at least water, an organopolysiloxane having Si-bonded hydrogen and a water-soluble, film-forming polymer having a turbidity point of from 35.degree. to 98.degree. C.

Abstract: Aqueous redispersible powders which contain a water-soluble polymer and at least one organic silicon compound, in which at least 50 percent by weight of the organic silicon compound(s) used to prepare these powders are liquid or solid at room temperature at 1,020 hPa (abs.), have a boiling point of at least 150.degree. C. at 1,020 hPa (abs.), and contain an average of not more than 1.8 SiC-bonded organic radicals per silicon atom, and have at least one hydrogen atom bonded directly to silicon per molecule, or at least one hydroxy group bonded to silicon per molecule, or at least one hydrocarbon radical bonded to silicon via oxygen per molecule which may be substituted by an alkoxy group, or a mixture of at least two such condensable substituents in which the organic silicon compound(s) are used in an amount of at least 30 percent by weight, based on the total weight of the powder (calculated as anhydrous powder).

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.

Abstract: A process for the preparation of aqueous polymer dispersions comprising polymerizing compounds with unsaturated ethylenic bonds at a temperature of 10.degree. to 100.degree. C. in the presence of an at least partially water-soluble free-radical initiator and at least one starch and/or starch derivative and optionally present conventional adjuvants with the starting mixture containing not more than one third of the total monomers and the remaining monomer being added during the polymerization, the initiators being at least one member of the group consisting of hydrogen peroxide, ketone peroxides and organic hydroperoxides in an amount of at least 30 mmol per kg of total monomer mixture and optionally present water-soluble reducing agents and the starch is water-soluble or gells in water and contains not more than 30% by weight of amylose and the starch derivative is hydrolyzed starch in an amount of at least 0.6% by weight based on the total monomer weight.

Abstract: A process for the preparation of aqueous polymer dispersions comprising polymerizing compounds with unsaturated ethylenic bonds at a temperature of 10.degree. to 100.degree. C. in the presence of an at least partially water-soluble free-radical initiator and at least one water-soluble protein and optionally present conventional adjuvants with the starting mixture containing not more than 40% of the total monomers and the remaining monomer being added by metering during the polymerization, the initiators being at least one member of the group consisting of ketone peroxides and organic hydroperoxides in an amount of at least 30 mmol per kg of total monomer mixture and optionally present water-soluble reducing agents and the amount of protein being at least 3% by weight based on the total monomer weight and at least 30% by weight is added during the polymerization and the isoelectric point of the protein is not reached or exceeded during polymerization.

Abstract: A process for the preparation of aqueous polymer dispersions comprising polymerizing vinyl esters and up to 50% by weight of the total monomer of compounds with unsaturated ethylenic bonds at a temperature of 10.degree. to 100.degree. C. in the presence of an at least partially water-soluble free-radical initiator and at least one starch member of the group consisting of cyanalkylated starch, hydroxyalkylated starch and carboxyalkylated starch and optionally present conventional adjuvants with the starting mixture containing not more than one-third of the total monomers and the remaining monomers being added by metering during the polymerization, the initiators being at least one member of the group consisting of hydrogen peroxide and organic hydroperoxides in an amount of at least 30 mmol per kg of total monomer mixture and optionally present water-soluble reducing agent and the amount of starch being at least 1% by weight based on the total monomer weight.

Abstract: A process for the preparation of aqueous dispersions, also emulsion (co)polymerization of vinyl halides and/or vinyl esters and, if needed, additional monomers in the absence of emulsifying agents are described. Protective colloid is added after the initiation of the polymerization to stabilize the forming dispersion. The dispersions are characterized by low viscosity, even with high solids contents, and low structural viscosity, and they are suitable a.o. especially for the preparation of redispersible powders.