Compound, ink, process and use

摘要

A compound of Formula (1) or salt thereof: wherein: A1 and A2 are each independently optionally substituted aryl; Q1 and Q2 are each independently an optionally substituted arylene or polycyclic heteroarylene group each comprising a phenylene ring which is para connected to the -N-N- and the -NR- groups shown in Formula (1); and each R is independently H or a substituent; L is a linking group containing at least one group selected from sulfonic acid, phosphonic acid, carboxylic acid and sulfonamide groups. The compounds have good ozone and light fastness are especially suitable for use in ink jet printing inks.