Thermochromic composition

Abstract

A thermochromic composition which comprises (1) an electron-donating chromogenic organic compound, (2) an electron-accepting compound, and (3) at least one desensitizer selected from among carbazole derivatives of the following formulas: ##STR1## wherein R is an alkyl group containing 1 to 22 carbon atoms, a phenyl group or a benzyl group and X is a hydrogen atom, a halogen atom, --NH.sub.2, --NO.sub.2 or --CHO; ##STR2## wherein R is an alkyl group containing 1 to 22 carbon atoms and X is a hydrogen atom, a halogen atom, --NH.sub.2, --NO.sub.2 or --CHO. A thermochromic composition which comprises (1) an electron-donating chromogenic organic compound, (2) an electron-accepting compound, (3) at least one desensitizer selected from among carbazole derivatives mentioned above, and (4) a thermochromic transition temperature modifier. A thermochromic composition which comprises one of the thermochromic compositions mentioned above as enclosed in microcapsule.

Dependencies are inferred from the claim text.