Bayer Aktiengesellschaft

Klaus Hoehne

Diez Heine

Rolf Baatz

Johann Jelen

Josef Pedain

Klaus Nachtkamp

Klaus Noll

Franz Weider

This invention relates to a new process for the preparation of storage stable aqueous dispersions or solutions of cross-linkable polyurethane polyureas containing heat activated cross-linking agents, in which mixtures of hydrophilically modified prepolymers containing isocyanate groups, hydrophobic polyisocyanates which contain blocked isocyanate groups and are neither soluble nor dispersible in water, and compounds containing at the most one free aminic or hydrazinic primary or secondary amino group and at least one blocked group which under the influence of water forms a free aminic or hydrazinic primary or secondary amino group and a total of at least two such amino groups are prepared in the absence of water and then mixed with water, and it also relates to the aqueous dispersions or solutions obtained by this process and to their use for the production of coatings on heat-resistant substrates.

Process for the preparation of aqueous dispersions or solutions of

A process for the preparation of chlorinated aliphatic polymers wherein chlorine-free polymers are chlorinated by using gaseous chlorine in chlorinated hydrocarbons as solvents and the chlorinated aliphatic polymers are recovered from the chlorinating solution by steam distillation in which process from 15 to 50% by weight of a lacquer resin is added to the chlorinating solution before steam distillation. The chlorinated polymers contain less residual solvent.

Process for the preparation of chlorinated polymers

A process for the preparation of a chlorinated aliphatic polymer which comprises chlorinating a chlorine-free aliphatic polymer in a chlorinated hydrocarbon solvent using gaseous chlorine as the chlorinating agent; adding from 2 to 25% by weight, based on the chlorinated polymer, of at least one plasticizer and/or at least one lacquer resin, to the chlorination solution; and isolating the chlorinated aliphatic polymer from the chlorination solution by steam distillation.

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Leverkusen, Germany

Klaus Hoehne