. . "omatic carbocyclic radicals, and at least one of X, Y, and Z is substituted by ahydroxy group ortho to the point of attachment to the triazine ring, and at least one of R1 to R9 is an alkoxy radical of the formula, -O-(mixed alkyl) substituted at a point para to the point of attachment to the triazine ring, and the remainder of R1to R9 are selected from the group consisting of hydrogen, hydroxy, a" . .