Wacker-chemie Gmbh

Wacker Chemie Ag

Gerald Fleischmann

Herbert Eck

Hermann Petersen

Alfred Prasse

Benno Krueger

Heinrich Hopf

Ernst Innertsberger

Jakob Schmidlkofer

Kunigunde Kolbig

Johann Schuster

Konrad Alfons Wierer

Andreas Bockholt

Helmut Weber

Ekkehard Patrick

Frank Betschinger

Siegfried Pflaum

Stefan Neumann

Petra Wenzeler

Hohl Horst

Wolfgang Döring

Walter Goblmeier

Wolfgang Doering

Klaus Käppler

Manfred Böck

Benno Krüger

A method for converting organosilanes by reacting at least one silane (1) of the general formulaRSiCl  (I)with at least one further silane (2) of the general formulaRSiCl  (II)wherein silane (2) is identical or different from silane (1), optionally with additional use of silanes (3) which contain Si-bonded hydrogen and have the formulaRHSiCl  (III)in the presence of aluminum salts, preferably aluminum halides, as catalysts and in the presence of cocatalysts, to obtain at least one silane (4) which differs from silanes (1) and (2) and has the general formulaRSiCl  (IV).

Process for converting organosilanes

The invention relates to a process for preparing chloroacetaldehyde acetals of monohydric, dihydric or higher-functionality aliphatic alcohols, in which the chloroacetaldehyde acetal is obtained from an aqueous chloroacetaldehyde solution in the presence of the alcohol to be acetalized and an acid catalyst by azeotropic removal of water with the aid of a solvent, wherein the solvent is a halogenated solvent.

Process for preparing chloroacetaldehyde acetals

The invention relates to a safely handleable and transportable composition including an alpha-cyclodextrin-chlorine dioxide complex and an inert substance, and also a method for production thereof.

Composition comprising an alpha-cyclodextrin-chlorine dioxide complex and  an inert substance, and also method for production thereof

A process for preparing hydroxytyrosol, wherein a compound where X is CHOH or CHOM (M=Li, Na, K, Mg, Ca), Rand Rare identical or different and are C1-C8 alkyl radical, benzyl radical, alkyl- or halogen-substituted benzyl radical or arylalkyl radical, where Rand Rcan also be linked via to give a ring, R, R, Rand Rare identical or different and are hydrogen or C1-C6 alkyl radical, aryl radical, alkyl-substituted aryl radical, where Rand Rcan also be linked via &#x2014;(CH)&#x2014;, &#x2014;(CH)&#x2014; or &#x2014;(CH)&#x2014; to give a ring, is reacted with an aluminum compound AlRRR(2), where R, Rand Rare identical or different and are H or C1-C8 alkyl radical, and then an aqueous solution of a hydroxycarboxylic acid is added to form a clear homogeneous acidic solution with a pH&#x3c;3, and hydroxytyrosol is extracted therefrom.

Process for the preparation of hydroxytyrosol

The invention relates to a process for the preparation of microcapsulated flakes or powders by drying aqueous mixtures containing (a) one or more water-emulsifiable, non-thermoplastic compounds which have a higher boiling point than waterand (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.

Process for the microencapsulation of water-emulsifiable

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 of 10 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 comprising

Process for the preparation of biologically degradable aqueous

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.

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&gt;50,000.

Biodegradable vinyl ester copolymers

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.

Process for preparing ketene acetals

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.

Organopolysiloxane compositions which cross-link to give elastomers

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. The initiators used in the quasi-ionic polymerization are selected from group (I) consisting of cyclic silazanes, polymeric silazanes which contain more than two silazanyl groups per molecule, cyclic siloxanes and polymeric siloxanes which contain more than two siloxanyl groups per molecule and at least one Si-bonded hydrogen atom and silanes having at least one Si-bonded N atom in the form of secondary or tertiary amido groups or at least one Si-bonded carbon atom in the form of alkynyl or cyclodienyl groups for each Si atom, or group (II) consisting of silanes having at least three silyl groups per molecule, germanes, stannanes or siloxanes, germoxanes or stannoxanes, in which at least one metal-bonded hydrocarbyloxy group is present for each metal atom.

Process for polymerizing polar compounds

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 formula

Process for strengthening the adhesion of polymeric substances to

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. In a similar process, the polar compounds can be polymerized by the group-transfer method with alkenyl trialkylsilylacetates and the polymeric acrylic compounds modified with terminal acetoxyalkenyl groups thus obtained can be added to the polyorgano-H-siloxanes.

Modified poly(organo-organosiloxanes) with comb or block structures and

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.

Process for the polymerization of polar compounds

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.

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Burghausen, Germany

Gerald Fleischmann