Polymer/polyisocyanates

In a polymer/polyisocyanate composition which is convertible by reaction with a poly(active hydrogen) organic compound having two or more active hydrogens to a polyurethane product wherein the polyisocyanate of said composition is normally liquid at the temperature at which said composition is convertible to said polyurethane product and the polymer of said composition is formed in situ in said polyisocyanate thereof from a polymerizable ethylenically unsaturated monomer and is essentially insoluble therein, the improvement providing more stable dispersions of small particles of said polymer in the polyisocyanate, comprising, an improved dispersion of said polymer prepared by the in situ polymerization of a major amount of acrylonitrile and a minor amount of one or more ethylenically unsaturated monomer(s) polymerizable with acrylonitrile in a liquid organic polyisocyanate material having a free NCO content of at least 10 wt.% and comprising at least about 20 wt. % of (1) polymeric diphenylmethylene diisocyanate having the formula:

• ##STR12## in which x is a number having an average of 1.1 to 5, (2) a mixture of diphenylmethylene diisocyanate, its carbodiimide having the formula:
• OCNR"N.dbd.C.dbd.NR"NCO, and its trifunctional trimeric cycloadduct having the formula:
• ##STR13## wherein R" is a ##STR14## or (3) mixtures of polyisocyanates (1) and (2) above, convertible by reaction with poly(active hydrogen) organic compound to a polyurethane product, said ethylenically unsaturated monomer(s) in an effective amount improving the affinity of the resulting polymer particles for said polyisocyanate and restricting agglomeration of said polymer particles in said polyisocyanate to provide a dispersion which forms films containing less than 10% seeds, the remaining area being glossy, or 5% seeds, the remaining area being semi-glossy, said percentages being on an area basis.

In a process for producing a liquid polymer/polyisocyanate composition which is convertible by reaction with a poly(active hydrogen) organic compound to a polyurethane product wherein the polyisocyanate of said composition is normally liquid at the temperature at which said composition is converted to said polyurethane product and said polymer is formed in situ in said polyisocyanate from one or more polymerizable ethylenically unsaturated monomers and is essentially insoluble therein, the improvement utilizing acrylonitrile or major amounts of acrylonitrile and minor amounts of one or more polymerizable ethylenically unsaturated monomer copolymerizable therewith and providing more stable dispersions of small particles of said polymer in said polyisocyanate, comprising, polymerizing acrylonitrile or major amounts of acrylonitrile and minor amounts of one or more polymerizable ethylenically unsaturated monomers copolymerizable therewith in a liquid polyisocyanate material having a free NCO content of at least 10 wt.% and consisting essentially of (1) polymeric forms of a diarylalkylene diisocyanate having the formula ##STR19## in which R is a trivalent aromatic group and x is a number having an average value of 1.1 to 5, (2) mixtures of a diarylalkylene diisocyanate, a carbodiimide of the formula:

• OCNR'N.dbd.C.dbd.NR'NCO, and a diarylalkylene diisocyanate trifunctional trimeric cycloadduct of the formula:
• ##STR20## wherein R' is a divalent arylenealkylenearylene group, or (3) mixtures of polyisocyanates (1) and (2) above, in an amount of about 10 to about 40 wt.% of acrylonitrile or acrylonitrile and said monomer(s) based on the total weight of acrylonitrile, said monomer(s) and said polyisocyanate in the presence of about one half to about 6 wt.% of a free radical catalyst on the same weight basis at a temperature ranging from about 25.degree. C. to about 200.degree. C. to form said composition in which said polymer is formed in situ from acrylonitrile and said monomer or monomers and is dispersed in said polyisocyanate, said ethylenically unsaturated monomer(s) in an effective amount improving the affinity of the resulting polymer particles for said polyisocyanate and restricting agglomeration of said polymer particles in said polyisocyanate to provide a dispersion which forms films containing less than 10% seeds, the remaining area being glossy, or 5% seeds, the remaining area being semi-glossy, said percentages being on an area basis.