Patent ID: 6417317
Filing Date: 2002-07-09
Classification: G03F

Abstract:
A process of producing a novolak resin comprising the step of condensing a novolak resin precursor and a trifunctional phenolic compound in the presence of an aldehyde or a ketone, wherein in said trifunctional phenolic compound, all of the o- and p-positions relative to the hydroxy group are hydrogen atoms;wherein said novolak resin precursor has a weight average molecular weight of 300 to 10,000, obtained by reacting at least one compound shown by the following formula (I): wherein each of R1 and R3 may be independently H, an alkyl group or alkenyl group each having from 1 to 3 carbon atoms; each of R2 and R4 is respectively an alkyl group or alkenyl group each having from 1 to 3 carbon atoms; each of R5 and R6 may be independently H, an alkyl group or alkenyl group each having from 1 to 3 carbon atoms; each of R7, R8, R9 and R10 may be independently H, OH, an alkyl group or alkenyl group each having from 1 to 3 carbon atoms, provided that when any one of R7, R8 or R10 is OH, R9 is not H, and when R9 is OH, none of R7, R8 or R10 is H; n denotes an integer from 0 to 3; and the letter â€œaâ€  denotes 0 or 1,with at least one compound shown by the following formula (II): wherein R11 is an alkyl or alkenyl group each having from 1 to 3 carbon atoms, each of R12 and R13 may be independently H, an alkyl group or alkenyl group each having from 1 to 3 carbon atoms; and the letter â€œaâ€  denotes 0 or 1.