Sakura Color Products Corporation

Masaaki Sumii

Yasuyuki Yoshimura

Fumiko Sakai

A thermochromic composition which comprises

Thermochromic composition

This invention provides the following production process. A microencapsulation process comprising encapsulating a hydrophobic core material with a melamine-formaldehyde polycondensate resin in the presence of an anionic macromolecular electrolyte system, characterized in that, as said anionic macromolecular electrolyte system,

Microencapsulation process

The invention provides the following dyeing method: A method of dyeing a cellulosic textile article characterized by immersing the article in an aqueous dispersion containing a cation-treated coloring agent in the first place and, then, immersing it in an aqueous solution or dispersion of an anionic compound.

Dyeing method

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.

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 diphenylamine derivatives of-the following formulas: ##STR1## wherein R.sup.1 and R.sup.2 each independently is H, an alkyl group containing 1 to 22 carbon atoms, ##STR2## (in which R.sup.3 and R.sup.4 each independently is H, an alkyl group containing 1 to 4 carbon atoms). 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 diphenylamine 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.

The invention relates to double-walled microcapsules each having a core of a hydrophobic substance, and a primary wall and a secondary wall formed therearound, the microcapsules being characterized in that the primary wall is composed of an amino resin prepared by polycondensation reaction of at least one member selected from the group consisting of:

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Sakai, Japan

Masaaki Sumii