| abstract |
The present invention relates to a process for the "in situ" preparation of stable dispersions of polyisocyanate polyaddition products in hydroxyl containing compounds as dispersing agents which comprises reacting 1. organic polyisocyanates with 2. compounds having primary and/or secondary amino groups and/or primary hydroxyl groups in 3. compounds having at least one hydroxyl group, compounds 3 having secondary hydroxyl groups if compounds 2 have primary hydroxyl groups and at least one of the components 1 or 2 having ionic groups and/or groups capable of salt formation, in the presence of from 2 to 50% by weight of water, based on the total quantity of reaction mixture, the improvement which comprises carrying out the polyisocyanate polyaddition reaction in the presence of a polymer latex or the solution of an ionic polyurethane. The invention also relates to the use of the stable dispersions made by the above process in making polyurethane resins. |