is a --COOH group, a --COH=NOH group, --CONHNH2 group, a --CONH2 group or a --CH=NOH group, salicyclic acid dreivatives represented by the formula: ##STR5## wherein each of R3 to R5 is a hydrogen atom or a C1-8 alkyl group, R6 is a hydrogen atom or a C1-8 hydrocarbon group having a valency of n, and n is an integer of from 1 to 4, and benzotriazolecarboxylic acid hydrazides represented by the for