A developer which contains a triphenolic compound (B) being a triphenolic compound (A) of the general formula (1) satisfying the requirements: (a) an OH group is present at one or more of 4- and 4'-positions of the left and right aromatic rings and (b) at least one of the substituents adjacent to at least one OH group on the left or right aromatic rings is hydrogen and which exhibits high sensitivity and image stability of images and less fog in non-image areas; and color forming materials and thermal recording materials made by using the same.
A developer which contains a triphenolic compound (B) being a triphenolic compound (A) of the general formula (1) satisfying the requirements: (a) an OH group is present at one or more of 4- and 4′-positions of the left and right aromatic rings and (b) at least one of the substituents adjacent to at least one OH group on the left or right aromatic rings is hydrogen and which exhibits high sensitivity and image stability of images and less fog in non-image areas; and color forming materials and thermal recording materials made by using the same.
v. Auwers; Saurwein, Chemische Berichte, 1922, vol. 55, p. 2384