A
ketone aldehyde resin having a water
content of less than 0.4% by weight, obtained by condensing at least one ketone with at least one
aldehyde in the presence of at least one alkali metal compound and at least one phase transfer
catalyst in the absence of solvent or in a water-miscible organic solvent, wherein the aldehyde
is added (1) in an initial charge at the beginning of the condensation; and (2) in at least one
further substep following initiation of condensation in (1), wherein the ketone is selected from
the group consisting of 4-tert-amylcyclohexanone, 2-sec-butylcyclohexanone,
2-tert-butylcyclohexanone, 4-tert-butylcyclohexanone, 2-methylcyclohexanone,
3,3,5-trimethylcyclohexanone, and mixtures thereof.