A phenolic resin composition comprising units of formula (I): ##STR1## wherein R1 is a halogen and R2 is a lower alkyl group having 1 to 4 carbon atoms, and said units of formula (I) are made by condensing the corresponding halogen-substituted resorcinol of formula (A): ##STR2## wherein R1 is defined above, with the corresponding para-lower alkyl-substituted 2,6-bis(hydroxymethyl)-phenol of formul