GB1049288A - Polyurethanes - Google Patents

Abstract

A polyether of OH No. 343 is prepared by reacting tris (di-b -hydroxyethylamino) 1:3:5 triazine with propylene oxide, the latter being added in two stages.ALSO:Polyurethanes are prepared by reacting an organic polyisocyanate and a hydroxyl ended polyether of formula <FORM:1049288/C3/1> wherein R, R1, R11, R111, RIV and RV each stand for a hydrogen atom, an alkyl group or a hydroxyl ended polyether chain, at least two of the groups R being hydroxyl ended polyether chains. The hydroxyl ended polyether may have a M.W. of 300-10,000 and may be the oxyalkylation product of a hydroxy alkyl derivative of melamine. In the preparation of foams, surface coatings and adhesives the hydroxy ended polyether preferably contains at least three isocyanate reactive groupings. In an example a polyether of OH No. 343 was prepared from tris(di-b -hydroxyethylamino)-1:3:5-triazine and propylene oxide, the latter being added in two stages. The polyether was mixed with water, butylated urea formaldehyde, cyclohexanone, methyl isobutyl ketone and a solution of a phosgenated crude diaminodiphenylmethane to obtain a coating solution.ALSO:Substrates e.g. wood, rubber, metals, glass and fabrics are coated with a polyurethane coating composition obtained by reacting an organic polyisocyanate with a polyether of formula <FORM:1049288/B1-B2/1> where the groups R each stand for hydrogen, alkyl or a hydroxyl ended polyether chain, at least two of the groups R being hydroxyl ended polyether chains. In an example a polyurethane obtained from propoxylated tris (di-b hydroxyethylamino) - 1 : 3 : 5 triazine by reaction with a phosgenated crude diamino diphenylmethane in admixture with water, xylene, cyclhexanone, methyl isobutyl ketone, and butylated urea formaldehyde was applied by spinning to steel panels or by dipping to steel rods and dried.