Abstract: Polyvinyl acetals are obtained in a cost-effective and environmentally advantageous manner by employing as at least a portion of the aqueous acetalization medium, the mother liquor from a previous acetalization reaction.

Abstract: The invention relates to a process for preparing solid polyvinyl ester resins using a bulk or solution polymerization process in the presence of a chain transfer agent, wherein one or more vinyl esters of unbranched or branched alkyl carboxylic acids having 1 to 15 carbon atoms are polymerized in the presence of a compound selected from the group consisting of monovalent aliphatic alcohols having 1 to 6 carbon atoms, esters of aliphatic monocarboxylic acids and aliphatic alcohols each having 1 to 4 carbon atoms, or aliphatic ketones having 3 to 6 carbon atoms.

Abstract: The invention relates to a method for producing polyvinylacetals that can be obtained by saponifying a vinylester polymer and subsequently acetalizing the polyvinyl alcohol, which is obtained therewith, with one or more aldehydes selected from the group consisting of aliphatic and aromatic aldehydes having 1 to 15 C atoms, whereby: a) the polyvinyl alcohol is present in an aqueous medium; b) a pH value of <1 is set optionally by adding acid; c) the acetalization is initiated by adding the aldehyde constituent, and; d) the precipitated polyvinylacetal is separated from the filtrate by filtration. The inventive method is characterized in that 10 to 100% by weight of the aqueous medium consists of the filtrate of a previous preparation, and the filtrate produced in d) is optionally reused in another preparation.

Abstract: Low molecular weight polyvinyl acetals have a solution viscosity of from 2 to 12 mPas and a degree of polymerization Pw less than 200, and are obtained by hydrolyzing a vinyl ester polymer having a solution viscosity of from 1.0 to 1.6 mPas until the content of vinyl alcohol units is ?50 mol %, to produce a polyvinyl alcohol whose solution viscosity is from 1.0 to 2.0 mPas, and then acetalizing the resultant polyvinyl alcohol. The products may be used as binders and films of increased adhesion to substrates.

Abstract: Polyvinylacetal-grafted polymers in the form of their aqueous dispersions or water-redispersible powders, and based on emulsion or suspension polymerized base polymers of one or more monomers from the group consisting of vinyl esters, (meth)acrylates, vinylaromatics, olefins, 1,3-dienes and vinyl halides, and optionally, further monomers copolymerizable therewith, the base polymers grafted with polyvinylacetals having from 0 to 5.0 mol % of vinyl acetate units, from 75 to 95 mol % of vinyl alcohol units and from 0.1 to 20 mol % of acetal units which are derived from aldehydes having 3 to 7 C atoms, are useful as additives in construction compositions, as binders, and as adhesives, and may be dried to form readily water-redispersible polymer powders.

Abstract: The invention relates to a process for preparing solid polyvinyl ester resins using a bulk or solution polymerization process in the presence of a chain transfer agent, wherein one or more vinyl esters of unbranched or branched alkyl carboxylic acids having 1 to 15 carbon atoms are polymerized in the presence of a compound selected from the group consisting of monovalent aliphatic alcohols having 1 to 6 carbon atoms, esters of aliphatic monocarboxylic acids and aliphatic alcohols each having 1 to 4 carbon atoms, or aliphatic ketones having 3 to 6 carbon atoms.

Abstract: The invention provides functionalized copolymers in the form of their aqueous dispersions or water-redispersible powders, based on a) one or more monomers from the group consisting of vinyl esters of unbranched or branched alkylcarboxylic acids having 1 to 15 carbon atoms, methacrylic esters and acrylic esters of alcohols having 1 to 15 carbon atoms, vinyl aromatics, olefins, dienes, and vinyl halides, b) from 0.05 to 5.0% by weight of one or more hydrolyzable silane monomers from the group consisting of ethylenically unsaturated, hydrolyzable silicon compounds and hydrolyzable silicon compounds from the group consisting of epoxysilanes, aminosilanes, and mercaptosilanes, c) from 0.05 to 5.0% by weight of one or more monomers from the group consisting of ethylenically unsaturated epoxide compounds, d) from 0 to 2.

Abstract: A process for preparing polyvinyl alcohol by means of catalytic transesterification of an alcoholic polyvinyl ester solution and subsequent workup by means of isolation of the polyvinyl alcohol formed includes adding, prior to the transesterification of the polyvinyl ester solution, the acetic ester of the alcohol used as solvent, in an amount of from 5 to 70% by weight, based on the overall amount of alcoholic solvent and its acetic ester, and recycling the liquid phase obtained after isolation of the polyvinyl alcohol product to a further polyvinyl ester transesterification.

Abstract: Low molecular weight polyvinyl acetals have a solution viscosity of from 2 to 12 mPas and a degree of polymerization Pw less than 200, and are obtained by hydrolyzing a vinyl ester polymer having a solution viscosity of from 1.0 to 1.6 mPas until the content of vinyl alcohol units is ≧50 mol %, to produce a polyvinyl alcohol whose solution viscosity is from 1.0 to 2.0 mPas, and then acetalizing the resultant polyvinyl alcohol. The products may be used as binders and films of increased adhesion to substrates.

Abstract: A process for preparing polyvinyl alcohol by means of catalytic transesterification of an alcoholic polyvinyl ester solution and subsequent workup by means of isolation of the polyvinyl alcohol formed includes adding, prior to the transesterification of the polyvinyl ester solution, the acetic ester of the alcohol used as solvent, in an amount of from 5 to 70% by weight, based on the overall amount of alcoholic solvent and its acetic ester, and recycling the liquid phase obtained after isolation of the polyvinyl alcohol product to a further polyvinyl ester transesterification.

Abstract: Polyvinylacetal-grafted polymers in the form of their aqueous dispersions or water-redispersible powders, and based on emulsion or suspension polymerized base polymers of one or more monomers from the group consisting of vinyl esters, (meth)acrylates, vinylaromatics, olefins, 1,3-dienes and vinyl halides, and optionally, further monomers copolymerizable therewith, the base polymers grafted with polyvinylacetals having from 0 to 5.0 mol % of vinyl acetate units, from 75 to 95 mol % of vinyl alcohol units and from 0.1 to 20 mol % of acetal units which are derived from aldehydes having 3 to 7 C atoms, are useful as additives in construction compositions, as binders, and as adhesives, and may be dried to form readily water-redispersible polymer powders.

Abstract: The invention provides functionalized copolymers in the form of their aqueous dispersions or water-redispersible powders, based on

Abstract: The invention relates to protective-colloid-stabilized polymer compositions in the form of their aqueous polymer dispersions or water-redispersible polymer powders, which comprise at least one film-forming base polymer and a protective colloid, wherein the protective colloid is a sulfonated condensation product made from unsaturated di- or polycarboxylic acids and from at least one compound selected from the class encompassing diols, polyols, diamines and polyamines.

Abstract: Modified polyvinyl acetals are prepared by saponification of 1-alkylvinyl acetate-vinyl acetate copolymers, which contain 1-alkylvinyl acetate/vinyl acetate in a weight ratio of 1/99-40/60 and subsequent acetalization the saponification products containing at least 80% units of vinyl alcohol and 1-alkyl vinyl alcohol with one or more aliphatic aldehydes with 1-6 C atoms under acid catalysis in an aqueous and/or organic medium; as well as to a method for the manufacture and the use thereof, especially in printing inks.

Abstract: Fusible vinyl acetate copolymer fibers based on vinyl acetate copolymers are provided and contain (a) at least 40.0% by weight of vinyl acetate units; (b) 15.0 to 50.0% by weight of monomer units that consist of one or several chlorine-free, ethylenically unsaturated monomer units that consist of one or several ethylenically unsaturated monomers whose homopolymers have a glass transition temperature Tg from -100.degree. to 0.degree. C.

Abstract: The invention provides a coating composition for coating aluminum which is based on vinyl ester copolymers and an organic solvent, the vinyl ester copolymer comprisinga) 20 to 90 parts by weight of a vinyl ester of saturated aliphatic monocarboxylic acids having 1 to 5 C atoms,b) 0 to 70 parts by weight of a vinyl ester of saturated aliphatic monocarboxylic acids which have 9 to 10 C atoms and a quaternary C atom in the .alpha.-position relative to the carboxyl group,c) 0.05 to 10 parts by weight of one or more ethylenically unsaturated mono- or dicarboxylic acids having 3 to 10 C atoms or anhydrides thereof andd) 0 to 50 parts by weight of one or more ethylenically unsaturated monomers, the homopolymers of which have a glass transition temperature above 30.degree. C.The coating composition is free of chlorine-containing polymers and also avoids the necessity for using a chlorine-containing primer.

Abstract: An ultrasonic fluid-flow measuring device in which a measuring tube having a rectangular cross section and a measuring tube wall lying opposite a pair of ultrasonic transformers is provided. The device utilizes three flat surface elements angled with respect to each other to reflect an ultrasonic beam so as to guide its passage through the fluid. Such structure provides a device in which the flow of the fluid is not impaired at any place in the measuring tube, and in which the inner walls of the measuring tube are free of niches which might promote the deposition of particles located in the fluid.

Abstract: A brushless d-c motor having an electric commutation circuit in which the motor and circuit are inter-connected by a mating connector is disclosed. The mating parts of the connector may be connected in two configurations. In one configuration, the motor rotates in one direction and in the other configuration, the motor rotates in the opposite direction. The mating connector is disclosed as a plug connector having a plug and a mating jack in which the connection of the motor and circuit to the pin connectors of the plug and to the jack connectors of the jack, and the arrangement of the pin connectors and jack connectors is such that the motor rotates in opposite directions in the two configurations.