Wacker-chemie Gmbh

Reiner Figge

Hans-Peter Weitzel

Herbert Eck

Peter Ball

Rudolf Weissgerber

Reinhard Haerzschel

Richard Weidner

Herbert Barthel

Klaus Kohlhammer

Manfred Selig

Harald Zeh

Peter Tschirner

Robert Braunsperger

Joachim Schulze

Bernd Schilling

Wolfgang Haas

Wolfgang Roth-Greiner

Doris Bauer

Redispersible polymer powders are prepared by emulsion polymerization of ethylenical, unsaturated monomers in the presence of a protective colloidal stabilizer containing 20 to 95 weight percent of polymerized monomers containing sulfonic acid or sulfonate groups, 5 to 80 weight percent of polymerized monomers containing amide groups or hydroxylalkyl groups, and up to 5 weight percent of polymerized monomers which are hydrophobic, water-insoluble ethylenically unsaturated compounds. The redispersible polymers are suitable for use in construction materials and coatings, and exhibit higher water resistance than similar polymers stabilized with polyvinyl alcohol as a colloidal stabilizer.

Process for preparing aqueous polymer dispersions

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.

Protective-colloid-stabilized polymer compositions

The invention provides a redispersible polymer powder based on a mixture of water-insoluble polymer and a water-soluble atomized protective colloid which can be de-activated through a pH change. In addition, the invention concerns aqueous dispersions that can be prepared with the polymer powder and the use of the polymer powder or its aqueous dispersions as a bonding agent in adhesives, plasters or paints.

Re-dispersible polymer powder and aqueous polymer dispersions obtainable therefrom

The invention relates to a method of producing protective colloid free, aqueous dispersions of vinyl ester co-polymers by radical emulsion polymerization of 40 to 99.5 weight percent vinyl acetate, 0 to 40 weight percent of one or several alkenes, 0 to 40 weight percent of one or several monomers from the group consisting of vinyl esters of C,to C,alkyl carboxylic acids, and of (meth)acrylic-acid esters of alcohols with 1 to 12 C atoms and optionally, additional copolymerizable mono- or poly-ethylenically unsaturated monomers. Said method is characterized in that 0.1 to 5 weight percent of one or several emulsifiers are polymerized with a persulfate initiator in the presence of 0.5 to 20 weight percent mono- or poly-ethylenically unsaturated carboxylic acid amides or derivatives thereof. The invention also relates to a method for producing protective colloid-free dispersion powders by spray drying or freeze drying said dispersions.

Method for producing protective colloid-free dispersions and dispersion powders

Crosslinkable powder composition which is redispersible in water

Redispersible tackifier powders

Redispersible, dispersion-powder composition

Process for treating mineral coating agent and binder compositions with

Process for preparing water-redispersible powder compositions comprising

Wood glue powder

The invention is a ready-to-use, water-redispersible powder composition useful for preparing photographic recording materials or inkjet recording materials, which comprises a mixture containing polymers made from ethylenically unsaturated monomers and gelatin, wherein the polymers are prepared by emulsion polymerization in the presence of at least one emulsifier selected from emulsifiers with ionic and nonionic groups and if exclusively ionic emulsifiers are used, the copolymerization is carried out in the presence of comonomers which contain one or more groups selected from --COOH, --OH, SO.sub.3.sup.-, NCH.sub.2 OH and --C.dbd.O.

Redispersible powder compositions for preparing photographic recording

Redispersible polymer powder composition comprising cyclodextrins or

The invention provides a redispersibte dispersion powder composition comprising a) a base polymer selected from the group consisting of vinyl ester polymers, styrene polymres, acrylate polymers and vinyl chloride polymers, b) from 2 to 15% by weight, based on the weight of the base polymer, of polyvinyl alcohol having a degree of hydrolysis of from 85 to 95 mol % and a Hoppler viscosity of from 2 to 25 mPa.s, c) from 3 to 30% by weight, based on the total weight of polymeric components, of fine antiblocking agent, and d) from 1 to 15% by weight, based on the weight of the base polymer, of an aminofunctional polyvinyl alcohol soluble in cold water and having a Hoppler viscosity of from 1 to 20 mPa.s and a saponification number of from 0 to 250, which comprises residues of aminofunctional vinyl units of the formula CH.sub.2 .dbd.CH--(CH.sub.2).sub.x --NH.sub.2, wherein x is a number of from 0 to 4. The dispersion powder compositoin of the invention is particularly suitable for use in building materials, in particular, dry mortars comprising Portland cement as inorganic binder, and leads in these to increased adhesive strength of the mortar.

Redispersible dispersion powder composition

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Ampfing, Germany

Reiner Figge