Abstract: The present invention relates to isocyante prepolymers containing ether and ester groups, having an isocyanate content of 1.9% to 25% by weight and based on the reaction product ofA) a polyisocyanate component containing at least one organic polyisocyanate having an average molecular weight of 168 to 1000,B) an organic polyhydroxyl component containing at least one polyhydroxyl compound containing ether and ester groups, having an average hydroxyl functionality of 2 to 3 and an average hydroxyl number of 40 to 90 and based on the esterification products ofi) polyether polyols having an average hydroxyl number of 200 to 600 withii) from 25 to 67 equivalent-%, based on the hydroxyl groups of component (i) and the carboxyl groups of component (ii), of an organic carboxylic acid component containing at least one organic monocarboxylic acid or a mixture of at least one organic monocarboxylic acid with up to 20 carboxyl equivalent-%, based on all the carboxylic acids, of polybasic organic carboxylic acids.

Abstract: This present invention relates to a process for the preparation of O-silylated aliphatic hydroxyl, compounds by the reaction of aliphatic hydroxyl compounds with triorganochlorosilanes and removal of the resulting gaseous hydrogen chloride from the reaction mixture, characterized in that the reaction is carried out in the presence of phase transfer catalysts in the absence of solvent.The invention also relates to the use of the O-silylated hydroxyl compounds obtained by this process as starting materials for the preparation of isocyanates containing ester groups by a reaction with isocyanato carboxylic acid chlorides.

Abstract: The present invention relates to polyisocyanates which contain ester groups and havea) a content of aliphatically bound isocyanate groups of 18 to 33% by weight,b) an average NCO functionality of 4.1 to 10, preferably from 4.5 to 10, andc) a viscosity of 200 to 2,5000 mPa.s at 22.degree. C.The present invention also relates to preferred polyisocyanates which contain ester groups and havea) a content of aliphatically bound isocyanate groups of 20 to 33% by weight,b) an average NCO functionality of 5 to 8 andc) a viscosity of 500 to 1,000 mPa.s at 22.degree. C.The present invention further relates to a process for the preparation of these preferred polyisocyanates by reacting isocyanatocarboxylic acid chlorides with O-silylated, polyhydric alcohols at a temperature of about 50.degree. to 150.degree. C. Finally, the present invention relates to the use of the polyisocyanates as the isocyanate component for two-component polyurethane coating compositions.

Abstract: The present invention relates to a coating composition which may be cured at elevated temperature and is based onA) a polyisocyanate component containing at least one organic polyisocyanate having reversibly blocked isocyanate groups and a molecular weight of 398 to 25,000, excluding the weight of the blocking agent, the isocyanate groups being reversibly blocked with a secondary monoamine andB) an isocyanate reactive component containing at least one organic polyamine having a molecular weight of 60 to 499 and at least two primary amino groups.The present invention also relates to the use of these coating compositions for the formation of coatings on heat resistant substrates.