Polyols based on modified amino resins, process for their preparation and their use

A process for preparing a polyol (A) based on modified amino resins, for use in a thermally curable composition, comprising reacting:

• an amino resin (B) comprising three acetalized or etherified N-methylol groups of the general formula I:
• >N—CHR—OR1 (I),
• wherein R is a hydrogen atom, an alkyl group of 1 to 6 carbon atoms or an aryl group of 6 to 10 carbon atoms and R1 is an alkyl group of 1 to 6 carbon atoms;
• with
• a polyol (C) of the general formula II:
• R2(—OH)n (II),
• wherein n is 2 and R2 is a divalent organic radical wherein polyol (C) is selected from the group consisting of positionally isomeric diethyloctanes containing a linear C8 carbon chain and functionalized with two hydroxy groups;
• wherein an equivalent ratio of the acetalized or etherified N-methylol groups to the polyol (C) is 0.5:1 to 1.2:1;
• with elimination of at least 50 mol % of a monoalcohol (D) of the general formula Ia:
• R1—OH (Ia),
• wherein R1 is as defined above, from the amino resin (B);
• and
• wherein the polyol (A) is capable of use in preparing a thermally curable coating material.

A thermally curable material comprising a polyol (A) based on modified amino resins and a polyisocyanate, wherein the polyol (A) is prepared by reacting:

• an amino resin (B) comprising three acetalized or etherified N-methylol groups of the general formula I:
• >N—CHR—OR1 (I),
• wherein R is a hydrogen atom, an alkyl group of 1 to 6 carbon atoms or an aryl group of 6 to 10 carbon atoms and R1 is an alkyl group of 1 to 6 carbon atoms;
• with a polyol (C), wherein polyol (C) is 2,4-diethyloctane-1,5-diol;
• wherein an equivalent ratio of the acetalized or etherified N-methylol groups to the polyol (C) is 0.5:1 to 1.2:1;
• with elimination of at least 50 mol % of a monoalcohol (D) of the general formula Ia:
• R1—OH (Ia),
• wherein R1 is as defined above, from the amino resin (B).