Monoazo colorants for mass-colouring of polymers

A compound of formula

• or a tautomer thereof, wherein
• M1 is H, ½ M2, ⅓ M3 or NR4R5R6R7,
• M2 is an alkaline earth or transition metal in oxidation state II or an oxo-metal in oxidation state IV,
• M3 is Al (III), a transition metal in oxidation state III or an oxo-metal in oxidation state V,
• R8 is a non-ionic substituent, different from hydrogen, having a para Hammett constant σp of from −0.3 to 0.6,
• R9 is H or, independently of R8, a further non-ionic substituent having a para Hammett constant σp of from −0.3 to 0.6,
• R10 is H, C1-C6alkyl, CO—C1-C6alkyl or CO-phenyl, and
• R4, R5, R6 and R7 are each independently of the others H or phenyl, benzyl or C1-C6alkyl, which are unsubstituted or substituted by hydroxy or by halogen and in the case of C3-C6alkyl is uninterrupted or interrupted by O.

A compound of formula

• or a tautomer thereof, wherein
• M4 is ½ M2, ⅓ M3 or NR4R5R6R7,
• M2 is an alkaline earth or transition metal in oxidation state II or an oxo-metal in oxidation state IV,
• M3 is Al (III), a transition metal in oxidation state III or an oxo-metal in oxidation state V,
• R9 is H or, independently of R8, a further non-ionic substituent having a para Hammett constant σp of from −0.3 to 0.6,
• R10 is H, C1-C6alkyl, CO—C1-C6alkyl or CO-phenyl, and
• R4, R5, R6 and R7 are each independently of the others H or phenyl, benzyl or C1-C6alkyl, which are unsubstituted or substituted by hydroxy or by halogen and in the case of C3-C6alkyl is uninterrupted or interrupted by O.