Wacker-Chemie Gmbh

Hartmut Brabetz

Herbert Eck

Heinrich Hopf

Reinhard Jira

Dieter Gorzel

Hubert Wiest

Christof Kemenater

Wilhelm Kaiser

Heinz Schafer

Franz Six

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.

Aqueous polymer dispersions preparation

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.

Polymerization process for aqueous polymer dispersions of vinyl esters

A non-woven material containing from 2% to 25% by dry weight of an alkali-soluble, water-resistant in neutral to weakly acidic solutions, binder for non-woven materials based on an aqueous vinyl acetate copolymer containing protective colloids and optionally emulsifiers and having the following monomer units

Alkai-soluble, water-resistant binders for non-woven materials

An aqueous copolymer adhesive dispersion having a long pot life and giving highly waterproof bonds, comprising an acid hardener of water-soluble acids having pKs of under 0 and an aqueous dispersion of a pre-crosslinked polyvinyl ester grafted onto polyvinyl alcohol, said polyvinyl ester being an ester of an acid of 1 to 12 carbon atoms and said pre-crosslinking caused by the presence of small amounts of poly-ethylenically-unsaturated compounds in the monomer mixture, as well as the aqueous dispersion and the method for its production.

Adhesive aqueous dispersions of polyvinyl alcohol graft polymers with

Ester copolymers cross-linkable under acid, alkaline and heated conditions consisting essentially of a copolymerizate with from 75% to 99% by weight of vinyl and/or acrylic ester monomer units, from 0.2% to 15% by weight of olefinically-unsaturated halotriazine monomer units, from 0.2% to 10% by weight of mono-olefinically unsaturated monomer units containing free or protected N-methylol groups and, optionally, up to 10% by weight of other monomer units copolymerizable with ester monomer units.

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Burghausen, Germany

Hartmut Brabetz