Hoechst Aktiengesellschaft

Celanese International Corporation

Clariant Corporation

Celanese Emulsions Gmbh

Ulrich Desor

Martin Jakob

Stephan Krieger

Ivan Cabrera

Matthias Junk

Marc Theodorus Ratering

Thomas Fichtner

Christoph Deller

Argiri Tsami-Schulte

Marc Ratering

A polymer dispersion is produced by polymerization of at least two different ethylenically unsaturated monomers in at least first and second stages. The polymer produced in the first stage comprises 25 to 60% by weight of the total monomer composition and has a uniform glass transition temperature from &#x2212;30&#xb0; C. to 0&#xb0; C. The polymer produced in the second stage comprises 40 to 75% by weight of the total monomer composition and has a variable monomer composition such that the second stage polymer has a non-uniform glass transition temperature which varies between a first value from &#x2212;30&#xb0; to +10&#xb0; C. and second value of at least +70&#xb0; C. Any polymer produced in further polymerization stages comprises no more than 10% by weight of the total monomer composition and the glass transition temperature of the hypothetical uniform copolymer produced by the total monomer composition is in the range from 0&#xb0; C. to 25&#xb0; C.

Polymer dispersions

An aqueous polymer composition is described comprising a homogeneous acrylic polymer dispersion produced by emulsion polymerization of a monomer mixture comprising: (A) from 85 to 99.9 wt % of one or more main monomers selected from C-C-alkyl esters of acrylic acid or C-C-alkyl esters of methacrylic acid, styrene, and vinyl toluene in such a ratio as to produce a polymer having a Tg in the range of &#x2212;20 to +65&#xb0; C.; and (B) from 0.1 to 5 wt % of at least one stabilizing monomer selected from ethylenically unsaturated monocarboxylic acids or amides thereof, ethylenically unsaturated dicarboxylic acids or anhydrides or amides thereof, ethylenically unsaturated sulfonic acids, ethylenically unsaturated phosphoric acids, and ethylenically unsaturated phosphonic acids. The emulsion polymerization is conducted in the presence of 0.05 to 3 wt %, based on the total weight of monomers in the monomer mixture, of a chain transfer agent (C).

Aqueous polymer dispersions

A polymer dispersion having a minimum film-forming temperature in the range from 0 to 40.degree. C., which is useful in coating compositions for substrates, in the form of varnishes or gloss paints, is obtained by stepwise emulsion polymerization, which includes polymerizing, onto a first stage having the monomer composition I comprising: from 50 to 68.5% by weight of soft monomers A whose homopolymers have a glass transition temperature (T.sub.g) below 0.degree. C.; from 30 to 50% by weight of hard monomers B whose homopolymers have a glass transition temperature (T.sub.g) above 65.degree. C.; from 0.5 to 5% by weight of .alpha.,.beta.-unsaturated carboxylic acids and/or carboxamides C which are copolymerizable with A and B; from 1 to 7.5% by weight of ethylenically unsaturated monomers D containing keto groups; and from 0 to 10% by weight of other ethylenically unsaturated monomers E which do not contain a nitrogen atom, where the weight percentages in each case are based on the overall amount of the polymer of the first stage, a second stage having the monomer composition II comprising: from 5 to 45% by weight of soft monomers A whose homopolymers have a glass transition temperature (T.sub.g) below 0.degree. C.; from 65 to 95% by weight of hard monomers B whose homopolymers have a glass transition temperature (T.sub.g) above 65.degree. C.; from 0 to 4% by weight of .alpha.,.beta.-unsaturated carboxylic acids and/or carboxamides C which are copolymerizable with A and B; from 0 to 5% by weight of ethylenically unsaturated monomers D containing keto groups; and from 0 to 10% by weight of other ethylenically unsaturated monomers E which do not contain a nitrogen atom, where the weight percentages in each case are based on the overall amount of the polymer of the second stage, in a weight ratio of the monomer composition I to the monomer composition II of from 50:50 to 75:25.

Aqueous polymer dispersions as binders for elastic, nonblocking and

Aqueous dispersions which comprise an emulsion polymer which is stable with respect to polyvalent zirconium ions, and a water-soluble zirconium compound, prevent the penetration of constituents from substrates which show a tendency to bleeding, and the dispersions are therefore suitable as a primer, especially for woods.

Aqueous dispersions useful for primer coatings

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Idstein, Germany

Ulrich Desor