Stabilization of pyrrolopyrrole pigments

Claim 1

A light-stabilised pigment composition comprising a) at least one pyrrolo[3,4-c]pyrrole pigment of the formula ##STR129## in which A and B, independently of one another, are isocyclic or heterocyclic aromatic radicals; and D is an oxygen or sulfur atom; and b) from 1 to 100% by weight, based on the pigment, of a nitroxyl compound of the formula ##STR130## in which R 12 is C 1 -C 18 alkyl or C 1 -C 18 alkoxy; G is a divalent group of the formula --CR 13 ═CH-- or --CHR 13 --CH 2 --; R 13 is C 1 -C 18 alkyl; Q is a group of the formula ##STR131## in which the bond denoted by * is the bond leading to T; T is a direct bond or a group of the formula ##STR132## in which R 14 is hydrogen, halogen or C 1 -C 4 alkyl, is --(CH 2 ) r --, in which r is 1 or 2; m is the number 1, 2, 3, 4 or 6; X, if m=1, is hydrogen, C 1 -C 18 alkyl, phenyl which is unsubstituted or substituted by C 1 -C 4 alkyl, C 1 -C 4 alkoxy, phenyl or halogen, or, under the condition that T, if bonded to a nitrogen atom, is not a direct bond, is a group of the formula --OCO--NR 15 R 16 , --OSO 2 --NR 15 R 16 , --OCO--R 16 , --COOR 16 ,--CONR 15 R 16 , --NR 15 --COR 16 , --NR 15 --CONR 15 R 16 , --OR 16 , --NR 15 R 16 , ##STR133## in which R 15 is hydrogen or C 1 -C 18 alkyl, R 16 is C 1 -C 18 alkyl, C 2 -C 12 alkenyl, C 5 -C 12 cycloalkyl, phenyl or naphthyl which is unsubstituted or substituted by C 1 -C 4 alkyl, C 1 -C 4 alkoxy, halogen, phenyl or nitro, or a --(CH 2 ) s --CHR 17 R 18 group where s is zero, 1, 2 or 3, R 17 is hydrogen, methyl or phenyl, and R 18 is --OH, halogen, --COOCH 3 or --COOC 2 H 5 ; X, if m=2, is a group of the formula --(CH 2 ) p or, under the condition that T, if bonded to a nitrogen atom, is not a direct bond, a group of the formula --O--(CH 2 ) o --O--, --NR 15 --(CH 2 ) p --NR 15 --, --OCO--M--COO--, --NR 15 --CO--M--CO--NR 15 --, --OCO--NH--M--NH--COO-- or --NR 15 --CONH--M--NHCO--NR 15 --, in which M is --(CH 2 ) p --, ##STR134## and p is a number between 2 and 10; X, if m=3, is a ##STR135## X, if m=4, is a ##STR136## X, if m=6, is a ##STR137## group; X 2 is C 8 -C 18 alkyl: n is the number 1 or 2; V, if n=1, is C 2 -C 8 alkylene, hydroxyalkylene or C 4 -C 22 acyloxyalkylene; or V, if n=2, is the (--CH 2 ) 2 C(CH 2 --) 2 or ##STR138## group; Z is a group of the formula ##STR139## in which the bond denoted by * is the bond leading to W; W, if n=1, is a --OCOR 19 group, in which R 19 is C 1 -C 18 alkyl, or phenyl or naphthyl which is unsubstituted or substituted by C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen; or W, if n=2, is a group of the formula --OCO--(CH 2 ) p --COO-- or ##STR140## and Y is O•.