Patent ID: 7635662

Claim:
A color-producing composition comprising a developer and a colorless or light-colored dye precursor, wherein the colorless or light-colored dye precursor is a leuco dye and develops color upon contact with said developer, wherein said developer is a urea-urethane composition obtained by reacting a polyisocyanate compound with a hydroxy compound and an amino compound, which is characterized by comprising 50 wt % or more of a urea-urethane compound having at least one urea group and at least one urethane group in a total number of 2 to 10 in the molecular structure and having a molecular weight of 5,000 or less, or wherein said developer is a urea-urethane composition obtained by reacting a polyisocyanate compound with a phenol compound and an amino compound, which is characterized by comprising 50 wt % or more of a urea-urethane compound having at least one urea group and at least one urethane group in a total number of 2 to 10 in the molecular structure and having a molecular weight of 5,000 or less, or wherein said developer is a urea-urethane composition obtained by reacting a polyisocyanate compound with an alcohol compound and an amino compound, which is characterized by comprising 50 wt % or more of a urea-urethane compound having at least one urea group and at least one urethane group in a total number of 2 to 10 in the molecular structure and having a molecular weight of 5,000 or less.