GB1086091A - A process for the production of urethane isocyanates - Google Patents

Abstract

Urethane isocyanates in admixture with trimerized monomeric diisocyanates are obtained by reacting one or more hydroxyl compounds which contain at least two hydroxyl groups capable of reacting with NCO groups, with one or more organic diisocyanates, in an excess of NCO groups over OH groups, and then trimerizing the remaining monomeric diisocyanate at a temperature below 150 DEG C. by adding a catalyst capable of polymerizing isocyanate groups and ending the latter reaction by adding a blocking agent for isocyanate polymerization when trimerization is complete. In examples toluylene diisocyanate and hexamethylene-1,6-diisocyanate are reacted with 1,1,1-trimethylolpropane, butane-1,3-diol and polypropylene glycols, and the products containing free diisocyanates are trimerized by adding tri-n-butylphosphine, pentamethyldiethylene triamine, sodium acetate and the lead salt of 2-ethylhexanoic acid as catalysts; the trimerization reactions are terminated by adding benzoyl chloride, p-toluene sulphonic acid methyl ester, ethyl acetate saturated with hydrogen chloride, and sulphuric acid dimethyl ester. Other starting materials, catalysts and blocking agents are mentioned.ALSO:Urethane isocyanates in admixture with trimerized monomeric diisocyanates are obtained by reacting one or more hydroxyl compounds which contain at least two hydroxyl groups capable of reacting with NCO groups, with one or more organic diisocyanates, in an excess of NCO groups over OH groups, and then trimerizing the remaining monomeric diisocyanate at a temperature below 150 DEG C. by adding a catalyst capable of polymerizing isocyanate groups and ending the latter reaction by adding a blocking agent for isocyanate polymerization when trimerization is complete. In examples toluylene diisocyanate and hexamethylene - 1,6 - diisocyanate are reacted with 1,1,1 - trimethylolpropane, butane - 1,3 - diol and polypropylene glycols, and the products containing free diisocyanates are trimerized by adding tri-n-butylphosphine, pentamethyl di-ethylene triamine, sodium acetate and the lead salt of 2-ethylhexanoic acid as catalysts; the trimerization reactions are terminated by adding benzoyl chloride, p-toluene sulphonic acid methyl ester, ethyl acetate saturated with hydrogen chloride, and sulphuric acid dimethyl ester. Other starting materials, catalysts and blocking agents are mentioned.