Abstract: An improved two component coating system based upon crosslinkable hydroxy containing polymers and a polyisocyanate crosslinker. The improvement resides in the utilization of a water-borne hydroxy-terminated polyurethane prepolymer/acrylate hybrid, preferably a hydroxy acrylate hybrid, in combination with a water-dispersible polyisocyanate.

Abstract: This invention relates to improved crosslinking systems for polymeric dispersions and solutions having suitability for coatings, adhesives and use in many other applications. These systems are based upon crosslinkable polymers having a plurality of activated keto methylene groups, e.g., a beta diketone such as an acetoacetate or a keto cyano methylene functional groups and a crosslinkable component comprising an aldimine. A sufficient amount of the aldimine curing agent is used to effect reaction with the polymer containing the activated keto methylene groups and cure thereof. The improvement in the crosslinking system resides in the utilization of a monoaldimine having only one aldimine group and no other methylene reactive group as a crosslinking agent. Another improvement variation to that previously suggested comprises a redispersible polymer(s) containing activated methylene functionality and combined with the monoaldimine and the use of heterocyclic aldimine.

Abstract: The invention consists of a composition containing a chemically blocked trimerization catalyst and a polyurethane prepolymer resin or resins with reactive isocyanate groups. In the absence of heat, the catalyst is not active and the solution of catalyst in the resin undergoes no appreciable reaction for periods ranging from hours to weeks depending upon the composition and concentration of the catalysts and the structure and concentration of the isocyanate groups. When heat is applied to the mixture a trimerization reaction occurs which produces a crosslinked polyurethane network with utility as an elastomer or as an adhesive.

Abstract: This invention relates to polyurethane coatings formed from prepolymers made by reacting polyisocyanates with long chain polyols having an average functionality of greater than 2. The resulting prepolymers have equivalent weights greater than about 250 grams per equivalent and preferably greater than about 350 grams per equivalent. An excess of polyisocyanate is reacted with the polyol component at an equivalent ratio of greater than 4:1 equivalents isocyanate per equivalent of polyol. Excess polyisocyanate is then removed from the prepolymer.The resulting polyurethane prepolymers are chain extended with compounds having active hydrogen atoms such as water, amines or short chain polyhydroxy compounds, e.g., diols to form the resulting coatings.

Abstract: A suspension process is described for the preparation of an essentially linear polyurethane-urea granule comprising the steps of:A. adding to an aqueous solution of from about 2% to about 20% by weight of a water-soluble inert suspension agent1. a non-aqueous solution comprising a hydrocarbon solvent, andA. an organic polyisocyanate,B. a water immiscible polyol, andC. a catalyst,Wherein the mole fraction of said organic polyisocyanate, with respect to said organic isocyanate and diol is from about 0.5 to 1.00;B. heating the reaction mixture of step (a) to a temperature of from about 50.degree. to 150.degree. C. with stirring sufficient to form a suspension and distilling a constant boiling distillate of said hydrocarbon solvent and water;C. terminating the distillation of step (b) when substantially no hydrocarbon solvent remains in said distillate and substantially no unreacted isocyanate remains in the reaction mixture; andD. separating the solid polyurethane-urea granule formed in step (b).