Self-compatibilizing phthalate-based polyester polyols

Claim 1

A process for preparing a high aromatic content low acid number self-compatibilized phthalate polyester polyol blend comprising the steps of: (1) heating at a temperature ranging from about 180° to 240° C. a starting mixture which comprises on a 100 mole percent total basis: (A) from about 15 to 40 mole percent of at least one phthalic acidic material selected from the group consisting of phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid, and mixtures thereof, (B) from about 40 to 75 mole percent of at least one aliphatic diol of the formula: HO--R.sup.1 --OH Where: R 1 is a divalent radical selected from the group consisting of: (a) alkylene radicals each containing from 2 through 6 carbon atoms (b) radicals of the formula: --(R.sup.3 O).sub.n --R.sup.3 -- where: R 3 is an alkylene radical containing from 2 through 3 carbon atoms, and n is an integer of from 1 through 3, and (C) from about 0.4 to 28.0 mole percent of at least one hydrophobic compound which is characterized by: (a) having an equivalent weight of from about 130 to 900, (b) containing from about 8 to 60 carbon atoms per molecule, and (c) containing at least one and not more than four radicals per molecule, which are each selected from the group consisting of carboxyl, hydroxyl, and mixtures thereof, said heating being continued until a liquid reaction product is produced which is characterized by having: (A) an hydroxyl number ranging from about 200 to 500, (B) an acid number ranging from about 0.1 to 7, (C) a saponification value ranging from about 215 to 300, and (D) a viscosity ranging from about 200 to 50,000 centipoises at 25° C. measuring using a Brookfield viscometer, and thereafter (2) admixing with said liquid reaction product from greater than 0 to about 30 weight percent of at least one nonionic propoxylate ethoxylate compound having a molecular weight ranging from about 1200 to 13,000.