Patent ID: 8598297

Claim:
A prepolymer comprising at least one urethane group, an average of between 1.8 and 6 isocyanate groups per molecule, and a number average molecular weight of from 500 to 8,000, wherein the prepolymer is a liquid at 22° C. and comprises the reaction product of at least one isocyanate and an isocyanate-reactive material containing at least one hydroxymethyl-containing polyester polyol (HMPP) derived from a fatty acid, wherein the HMPP has the following average structure: [H—X] (z-p) —R—[X—Z] p (I) wherein R is the residue of an initiator compound having z hydroxyl and/or primary or secondary amine groups, where z is at least two; each X is independently —O—, —NH— or —NR′— in which R′ is an inertly substituted alkyl, aryl, cycloalkyl, or aralkyl group, p is a number from 1 to z representing the average number of [X—Z] groups per hydroxymethyl-containing polyester polyol molecule, Z is a linear or branched chain containing one or more A groups, provided that the average number of A groups per molecule is ≧1.3 times z, and each A is independently selected from the group consisting of A1, A2, A3, A4 and A5, wherein A1 is: wherein B is H or a covalent bond to a carbonyl carbon atom of another A group; m is a number greater than 3, n is greater than or equal to zero and m+n is from 11 to 19, and wherein A1 is from 20 to 50 mole-% of A; A2 is: wherein B is as before, v is a number greater than 3, r and s are each numbers greater than or equal to zero with v+r+s being from 10 to 18, and wherein A2 is from 1 to 65 mole-% of A; A3 is: wherein B, v, each r and s are as defined before, t is a number greater than or equal to zero, and the sum of v, r, s, and t is from 10 to 18, and wherein A3 is from 0.1 to 10 mole-% of A; A4 is where w is from 10 to 24, and wherein A4 is up to 30 mole-% of A, and A5 is where R′ is a linear or branched alkyl group that is substituted with at least one cyclic ether group and optionally one or more hydroxyl groups or other ether groups, and wherein A5 is from 0 to 5 mole-% of A, wherein (i) the prepolymer is water-dispersable and contains at least one poly(ethylene oxide) block, or (ii) the prepolymer is dissolved in a solvent.