Delayed action/enhanced curing catalysis in polyurethane systems

In a method for the preparation of a polyurethane product by the reaction of a polyisocyanate with a polyester or polyether polyol in the presence of a tertiary amine catalyst, the improvement which comprises employing a catalytically effective amount of a composition consisting essentially of a tertiary amine of the following general formula:

• ##STR7## where R.sub.5, R.sub.6 and R.sub.7 are independently alkyl or hydroxyalkyl groups of 1 to 20 carbon atoms, or cycloalkyl groups of 3 to 8 carbon atoms, aralkyl, aryl, alkenyl of 2 to 20 carbon atoms or alkynyl 2 to 6 carbon atoms, or
• R.sub.5, R.sub.6 and R.sub.7 together with the nitrogen atom form an N-substituted heterocyclic 5 to 7 atom ring,
• and 1 to 35 wt%, based on tertiary amine, of an organic acid salt of a quaternary ammonium compound of the general formula:
• ##STR8## where R, R.sub.1 and R.sub.2 are independently alkyl or hydroxyalkyl groups of 1 to 4 carbon atoms, or together with the nitrogen atom form an N-substituted heterocyclic 5-7 atom ring structure,
• R.sub.3 is hydrogen or methyl and R.sub.8 is hydrogen, an alkyl group of 1 to 18 carbon atoms, an alkenyl group of 2 to 15 carbon atoms, benzyl or --CH.sub.2 CN.

A catalyst composition for the catalysis of the isocyanate/polyol reaction consisting essentially of a tertiary amine and 1 to 35 weight percent, based on the tertiary amine, of an organic acid salt of a quaternary ammonium compound of the formula:

• ##STR9## where a is 0 or 1,
• R, R.sub.1 and R.sub.2 are independently alkyl or hydroxyalky groups of 1 to 20 carbon atoms, or cycloalkyl groups of 3 to 8 carbon atoms, aralkyl (e.g. benzyl), aryl (e.g. phenyl), alkenyl of 2 to 20 carbon atoms, or alkynyl of 2 to 6 carbon atoms, or
• R, R.sub.1 and R.sub.2 together with the nitrogen atom form an N-substituted heterocyclic 5-7 atom ring structure;
• R.sub.3 is hydrogen, phenyl, an alkyl group of 1 to 15 carbon atoms, an alkenyl group of 2 to 15 carbon atoms, an alkynyl group of 2 to 6 carbon atoms, a hydroxyalkyl group of 1 to 9 carbon atoms, a ketoalkyl group having a total of 3 to 15 carbon atoms, or an alkoxy alkyl group having a total of 2 to 20 carbon atoms;
• Y is hydrogen, an alkyl group of 1 to 20 carbon atoms, an alkenyl group of 2 to 15 carbon atoms, a cycloalkyl group of 3 to 6 carbon atoms, phenyl, an alkylphenyl having 1 to 9 carbon atoms in the alkyl group or groups attached to the phenyl ring, benzyl, an alkylbenzyl having 1 to 9 carbon atoms in the alkyl group or groups attached to the benzene ring, or a
• CH.sub.(3-b) Z.sub.(b) group
• wherein
• b is 1 to 3 and Z is --OH, --CN, --Cl, an alkoxy group of 1 to 5 carbon atoms, a phenyl group or methoxyphenyl group, or
• Z is (CH.sub.2).sub.d COOR.sub.4 wherein d is equal to 0 to 4 and R.sub.4 is hydrogen or an alkyl group of up to 20 carbon atoms.