A process for production of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane
which comprises reacting phenol with 3,3,5-trimethylcyclohexanone in the presence
of an acid catalyst, separating the resulting phenol adduct crystals of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane
from the resulting reaction mixture, and removing the phenol from the phenol adduct
crystals, wherein the phenol adduct crystals are dissolved in a crystallization
solvent comprising an aromatic hydrocarbon solvent and water, crystallizing the
crystals of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane out of the crystallization
solvent, and collecting the crystals by filtration at a temperature of 40-60 C.