Ketone-aldehyde Resins, Especially Cyclohexanone-formaldehyde Resins with Low Water Content and High Thermal Stability and Yellowing Resistance, a Process for Preparing Them and Their Use

摘要

A ketone-aldehyde resin (I) having a water content of less than 0.4 wt.% is prepared by condensation of at least one ketone and at least one aldehyde in the presence of at least one alkali compound (A) and at least one phase transfer catalyst (B), optionally in a water-miscible organic solvent whereby an initial addition of the aldehyde is carried out at the beginning of the condensation with at least one further partial addition. A ketone-aldehyde resin (I) having a water content of less than 0.4 wt.% is prepared by condensation of at least one ketone and at least one aldehyde in the presence of at least one alkali compound (A) and at least one phase transfer catalyst (B), optionally in a water-miscible organic solvent whereby the addition of the aldehyde is carried out by an initial addition at the beginning of the condensation with at least one further partial addition following initiation of the condensation.