Abstract: A resin composition containing at least one compound (A) selected from compounds of formulas ##STR1## wherein R.sub.1 and R.sub.2 each denote a hydrogen atom, halogen atom, or alkyl or alkoxy group having 1 to 10 carbon atoms, ##STR2## R.sub.3 denotes a hydrogen atom, alkyl group containing 1 to 10 carbon atoms, naphthyl group or substituent of formula ##STR3## wherein R.sub.4 to R.sub.8, which may be the same or different, each denote a hydrogen atom, halogen atom, nitro group and alkyl or alkoxy group having 1 to 10 carbon atoms.

Abstract: A thermoplastic resin is colored with a carbon black pigment in the presence of a sulfonamide-substituted metal phthalocyanine dyestuff of the general formula ##STR1## wherein MePc is a metal phthalocyanine residue, R.sub.1 is a hydrogen atom or an alkyl group, R.sub.2 is an alkyl group, R.sub.3 is a hydrogen atom or an alkoxyalkyl group, R.sub.4 is an alkoxyalkyl group, m is an integer of 0 to 4, n is an integer of 0 to 4, and m+n is an integer of 1 to 4. The use of the specified metal phthalocyanine dyestuff affords a completely black or bluish black thermoplastic resin free from a reddish hue which is inherent to coloration with carbon black.

Abstract: A method for clear-coloring of linear aromatic polyesters, which comprises mixing at least one pigment selected from the group consisting of a pigment of the formula ##STR1## and pigments of the formula ##STR2## wherein X.sub.1 and X.sub.2 represent a hydrogen atom, a chlorine atom or a methyl group, and X.sub.3 represents a chlorine atom or a methyl group, with a linear aromatic polyester, and heating the mixture to the melting temperature of the polyester to dissolve or substantially dissolve the pigment in the polyester.