Patent ID: 7034185

Claim:
A colorant precursor compound of the formula wherein R is an alkyl group, an aryl group, an arylalkyl group, or an alkylaryl group, and wherein R can be joined to the phenyl moiety to form a ring, each R′, independently of the others, is a halogen atom, an alkyl group, an alkoxy group, a nitrile group, a nitro group, an amide group, or a sulfonamide group, z is an integer of 0, 1, 2, 3, or 4, n is an integer representing the number of carbon atoms in each repeat alkylene oxide unit, and x is an integer representing the number of repeat alkylene oxide units and is at least 10, wherein said colorant precursor has no more than one —OH, —SH, or primary or secondary amino group per molecule.