Reversible thermosensitive coloring recording medium, recording method, and image display apparatus using the recording medium

A reversible thermosensitive coloring recording method of reversibly forming a colored image or decolorizing the same in a reversible thermosensitive coloring recording medium comprising a support and a reversible thermosensitive coloring recording layer formed thereon, said reversible thermosensitive coloring recording layer comprising a reversible thermosensitive coloring composition consisting essentially of (i) an electron-donor coloring compound and (ii) an electron-acceptor compound selected from the group consisting of an organic phosphoric acid compound, an .alpha.-hydroxycarboxylic acid, and a phenolic compound, each having a straight chain or branched chain alkyl group or alkenyl group having 12 or more carbon atoms, said electron-donor coloring compound and said electron-acceptor compound being capable of reacting to induce color formation in said reversible thermosensitive coloring composition at the eutectic temperature thereof, and said electron-donor coloring compound and said electron-acceptor compound, when fused and colored in a mixed state, with application of heat thereto, followed by rapidly cooling said fused mixture, exhibiting an exothermic peak in a temperature elevation process in a differential scanning calorific analysis or in a differential thermal analysis, comprising the steps of:

• applying heat to the surface of said reversible thermosensitive coloring recording medium to a coloring temperature above said eutectic temperature of said electron-donor coloring compound and said electron-acceptor compound to obtain a colored state;
• and
• applying heat to the surface of said reversible thermosensitive coloring recording medium to a decolorizing temperature which is lower than said coloring temperature to obtain a decolorized state.

A reversible thermosensitive coloring display method of reversibly forming a colored image or decolorizing the same in a reversible thermosensitive coloring display medium comprising a support and a reversible thermosensitive coloring recording layer formed thereon, said reversible thermosensitive coloring recording layer comprising a reversible thermosensitive coloring composition consisting essentially of (i) an electron-donor coloring compound and (ii) an electron-acceptor compound selected from the group consisting of an organic phosphoric acid compound, an .alpha.-hydroxycarboxylic acid, and a phenolic compound, each having a straight chain or branched chain alkyl group or alkenyl group having 12 or more carbon atoms, said electron-donor coloring compound and said electron-acceptor compound being capable of reacting to induce color formation in said reversible thermosensitive coloring composition, and said electron-donor coloring compound and said electron-acceptor compound at the eutectic temperature thereof, when fused and colored in a mixed state, with application of heat thereto, followed by rapidly cooling said fused mixture, exhibiting an exothermic peak in a temperature elevation process in a differential scanning calorific analysis or in a differential thermal analysis, comprising the steps of:

• applying heat to the surface of said reversible thermosensitive coloring recording medium to a coloring temperature above said eutectic temperature of said electron-donor coloring compound and said electron-acceptor compound to obtain a colored state;
• and
• applying heat to the surface of said reversible thermosensitive coloring recording medium to a decolorizing temperature which is lower than said coloring temperature to obtain a decolorized state.

A reversible thermosensitive coloring recording method of reversibly forming a colored image or decolorizing the same in a reversible thermosensitive coloring recording medium comprising a support and a reversible thermosensitive coloring recording layer formed thereon, said reversible thermosensitive coloring recording layer comprising a reversible thermosensitive coloring composition consisting essentially of (i) an electron-donor coloring compound and (ii) an electron-acceptor organophosphoric acid compound having a straight chain or branched chain alkyl group or alkenyl group having 12 or more carbon atoms, said electron-donor coloring compound and said electron-acceptor compound being capable of reacting to induce color formation in said reversible thermosensitive coloring composition at the eutectic temperature thereof, and said electron-donor coloring compound and said electron-acceptor compound, when fused and colored in a mixed state, with application of heat thereto, followed by rapidly cooling said fused mixture, exhibiting an exothermic peak in a temperature elevation process in a differential scanning calorific analysis or in a differential thermal analysis, comprising the steps of:

• applying heat to the surface of said reversible thermosensitive coloring recording medium to a coloring temperature above said eutectic temperature of said electron-donor coloring compound and said electron-acceptor compound to obtain a colored state;
• and
• applying heat to the surface of said reversible thermosensitive coloring recording medium to a decolorizing temperature which is lower than said coloring temperature to obtain a decolorized state.

A reversible thermosensitive coloring display method of reversibly forming a colored image or decolorizing the same in a reversible thermosensitive coloring recording medium comprising a support and a reversible thermosensitive coloring recording layer formed thereon, said reversible thermosensitive coloring recording layer comprising a reversible thermosensitive coloring composition consisting essentially of (i) an electron-donor coloring compound and (ii) an electron-acceptor organophosphoric acid compound having a straight chain or branched chain alkyl group of alkenyl group having 12 or more carbon atoms, said electron-donor coloring compound and said electron-acceptor compound being capable of reacting to induce color formation in said reversible thermosensitive coloring composition, and said electron-donor coloring compound and said electron-acceptor compound at the eutectic temperature thereof, when fused and colored in a mixed state, with application of heat thereto, followed by rapidly cooling said fused mixture, exhibiting an exothermic peak in a temperature elevation process in a differential scanning calorific analysis or in a differential thermal analysis, comprising the steps of:

• applying heat to the surface of said reversible thermosensitive coloring display medium to a coloring temperature above said eutectic temperature of said electron-donor coloring compound and said electron-acceptor compound to obtain a colored state;
• and
• applying heat to the surface of said reversible thermosensitive coloring recording medium to a decolorizing temperature which is lower than said coloring temperature to obtain a decolorized state.