Two-component mixes for the preparation of polyurethane resins are well known. As a matter of fact, in an elemental sense, the first polyurethane resins were made by mixing two components, which is to say, by reacting together a polyol as one component and a diisocyanate as the other. This concept has become greatly refined and improved upon during the subsequent growth of the polyurethane resin industry. As a result, various two-component mixes have been reported. Two-component mixes are described, for example, in U.S. Pat. Nos. 4,410,597 and 4,101,473. Polyurethane coatings are known for use in the auto industry; see UK patent Application No. 2,147,910A, published May 22, 1985; and U.S. Pat. Nos. 4,554,188, 4,400,497, and 4,525,570. The use of dibutyl tin dilaurate and triethylene diamine catalysts is well known in the polyurethane art. See, e.g., U.S. Pat. No. 4,124,573.
Castor oil is known as a polyol reactant with diisocyanates to form polyurethanes. Ency. Pol. Sci. and Techn. 3, 25 (1965). An updated technical brochure entitled "Desmophen", available from Mobay Chemical Co., describes "Desmophen".RTM. as a "branched polyalcohol with ether and ester groups". The brochure discloses that Desmophen.RTM. can be reacted with isocyanates (not defined) to make polyurethane coatings for various applications. Our analyses indicate that "Desmophen" as currently available contains castor oil, cyclohexanone formaldehyde condensate, and a small amount of toluene.
U.K. Patent No. 1,182,884, Gruber and Fehlbier (1970) describes treatment of castor oil with cyclohexanone formaldehyde condensate, thereby providing modified castor oil as used in this invention. Reaction of the modified castor oil with MDI to make a polyurethane resin is also disclosed.