Product and process trimerization of organic isocyanates
AssigneeThe Upjohn Company
InventorEdward A. Barsa
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Abstract
Disclosed is a method for the trimerization of organic isocyanates comprising thermally activating, in the presence of said isocyanates, a catalyst comprising a carboxylic acid salt selected from the alkali metal salts or quaternary ammonium salts of particular substituted malonic acids or half-esters thereof, particular carbamyl substituted aliphatic acids, or triaryl acetic acids. Mixtures of the catalysts with isocyanates have surprisingly long periods of stability at ambient temperatures (about 20.degree. C.) which makes the present method particularly suitable to systems for molding polyiso-cyanurates wherein long open times are required of a resin pre-mix prior to the actual curing step.
Claims13
A method for the trimerization of an organic isocyanate comprising thermally activating at a temperature of from about 50.degree. C. to about 200.degree. C. in the presence of said isocyanate a catalyst otherwise having an induction period greater than one hour for initiating said trimerization at about 20.degree. C. said catalyst consisting essentially of a compound selected from the group consisting of the following formulae ##STR9## wherein R.sup.1 in (I) is alkyl having 2 to 8 carbon atoms, inclusive, and each R.sup.1 in (II) is independently selected from alkyl having 2 to 8 carbon atoms, inclusive, R.sup.2 is a highly branched alkyl having 3 to 8 carbon atoms, inclusive, R.sup.3 is selected from the group consisting of hydrogen, alkyl, and aryl, R.sup.4 is selected from the group consisting of alkyl, aryl, aralkyl, and cycloalkyl, each R.sup.5 is independently selected from aryl, and M.sup..sym. is a cation selected from the group consisting of alkali metal cations and quaternary ammonium cations having the formula .sup..sym. N(R.sup.6).sub.4 wherein each of the four R.sup.6 radicals is independently selected from the group consisting of alkyl, aralkyl, cycloalkyl, and radicals having the formula ##STR10## wherein R.sup.7 is selected from the group consisting of hydrogen and methyl and n is a number of from 1 to 4 provided that no more than one R.sup.6 radical has the formula (IV).
Dependencies are inferred from the claim text.