Isocyanate-functional polymers containing a terminal monosulfide group

Claim 1

An isocyanate-functional polymer of at least 10% by weight of isocyanatoalkyl acrylate or isocyanatoalkyl methacrylate, polymerized alone or with a polymerizable comonomer, any polymerizable comonomer being at least one member of the group consisting of alkyl acrylates and methacrylates; styrene; ethylene; vinyl acetate; and vinyl chloride, in the presence of 1-20% by weight, based on the weight of the polymer, of a mercaptan chain-transfer agent, wherein at least 10% by number of the polymer molecules have the following structure: ##STR5## where RS is the residue of a mercaptan chain-transfer agent, R-- being C 4 -C 12 alkyl, phenyl, benzyl or ##STR6## where R 3 -- is C 4 -C 12 alkyl, phenyl or benzyl and m is 0-8; R 1 is hydrogen or methyl; X is COO--A--NCO or a mixture of COO--A--NCO and at least one of ##STR7## where A is an alkylene group having 2-6 carbon atoms, and R 2 is an alkyl group having 1-12 carbon atoms; and n is 2-400 so that the polymer has a number average molecular weight, determined by gel permeation chromatography, utilizing polystyrene standards of polydispersity less than 1.1, of 500-10,000.