Abstract: Urea derivatives of formula 1 for the hardening of hydroxyl group-containing polymers, wherein each of R1-R7 is a hydrogen atom or a linear or branched C1-C4-alkyl group, preferably methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl, R1-R7 being identical or different, and R8 is a linear or branched C1-C6-alkyl group, preferably methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl. The compounds 1 are prepared by reacting a compound 2 wherein R9 is a member selected from the group consisting of —CHO, —CH(OH)—OR8 and —CH(OH)2 with a urea derivative 3 optionally followed by etherification of the reaction product with an alcohol X—OH, wherein X is a linear or branched C1-C4-alkyl group.

Abstract: Urea derivatives of formula 1 for the hardening of hydroxyl group-containing polymers.

Abstract: A process is described for the production of 3-alkyl-3-hydroxymethyloxetanes of the general formula (1), ##STR1## in which R.sup.1 denotes a linear or branched C.sub.1 -C.sub.12 alkyl group, which process comprises reacting a trimethylolalkane of the general formula (2),(HO--CH.sub.2).sub.3 C--R.sup.1 (2)in which R.sup.1 is defined as above, with a dialkyl carbonate of the general formula (3),R.sup.2 --O--(C.dbd.O)--O--R.sup.2 (3)in which R.sup.2 denotes a linear or branched C.sub.1 -C.sub.4 alkyl group, in the presence of a basic catalyst, wherein in a first stage the reaction mixture is stirred for at least 6 hours with refluxing at a temperature of 90-120.degree. C., in a second stage the alcohol formed R.sub.2 OH is distilled off at the same temperature and in a third stage the product formed is decarboxylated and deoligomerised at a temperature of 125-150.degree. C. and the desired 3-alkyl-3-hydroxymethyloxetane is simultaneously distilled off.