NEW MATERIAL: A dihydroxy compd. contg. bonded ester groups and represented by the formula (wherein R is a 2-20C linear or branched alkylene group, an optionally substd. 5-10C cycloalkylene group, or a polyoxyalkylene group comprising 2-50 oxyalkylene units arranged in block or randomly. each unit having 2-4 carbon atoms).

USE: Useful esp. for producing a polyisocyanate mixture which is liq. at room temp., has urethane groups, and is produced from 4,4'-diphenylmethane diisocyanate and other diphenylmethane diisocyanate isomers and/or polyphenyl- polymethylene-polyisocyanate.

PROCESS: For instance, a (1-3C)-alkyl hydroxypivalate is subjected to transesterification with a 2-20C alkanediol and a 5-10C cycloalkanediol to give a compd. represented by the formula.