Thermal recording material
AssigneeMitsubishi Paper Mills Limited
InventorShoji Hizatate
Life of this patent
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Abstract
Provided is a thermal recording material that is excellent in thermal response and retainability of an image portion and which generates fewer residues adhering to the thermal head of a thermal printer. The thermal recording material having a thermal recording layer comprising a generally colorless or light-colored electron-donating dye precursor and an electron-accepting developer that reacts under heat to cause said dye precursor to form a color, said thermal recording layer containing a specific diphenylsulfone derivative, a specific amide derivative and a specific fluorane derivative, wherein the weight ratio of the specific diphenylsulfone derivative above and the specific amide derivative above is 2/1 to 1/2.
Claims6
A thermal recording material having a thermal recording layer comprising a generally colorless or light-colored electron-donating dye precursor and an electron-accepting developer that reacts under heat to cause said dye precursor to form a color, said thermal recording layer comprising:
- 4,4′-dihydroxydiphenylsulfone (1),
- an amide derivative of the general formula (2),
- wherein A is an alkyl group, an alkenyl group or an alkylamino group, each of R3 and R4 may be the same as, or different from, other and is a hydrogen atom, an alkyl group, an alkenyl group, an aralkyl group or an aryl group, and
- a fluorane derivative of the general formula (3),
- wherein each R5 and R6 may be the same as, or different from, other and is an alkyl group having 1 to 5 carbon atoms, a cyclohexyl group or an aryl group, R7 is a hydrogen atom, methyl, trifluoromethyl or a halogen atom and R8 is a hydrogen atom, methyl or a halogen atom,
- wherein the weight ratio of the 4,4′-dihydroxydiphenylsulfone (1) and the amide derivative of the general formula (2) (compound (1)/compound (2)) is 2/1 to 1/2, and
- wherein said thermal recording layer comprises at least one compound selected from the group consisting of a compound of the general formula (4), a compound of the general formula (5), and a compound of the general formula (7), wherein the compound of the general formula (4) is
- wherein each of R9, R10 and R11 may be the same as, or different from, each other and is a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkali metal, an alkaline earth metal, a transition metal or an amine, and any two substituents of R9, R10 and R11 may bond to each other and form a ring,
- wherein the compound of the general formula (5) is
- wherein R12 is a group of the general formula (6),
- in which R15 is cyclohexyl, phenyl or tert-butyl and R16 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, cyclohexyl, phenyl or tert-butyl,
- R13 is a covalent bond or an alkylene group having 1 to 3 carbon atoms and
- R14 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or any group represented by R12, and
- wherein the compound of the general formula (7) is
- wherein R17 is a covalent bond, an alkylene group having 1 to 8 carbon atoms or a group of the general formula (8).
- in which R20 is 2,2,6,6-tetramethyl-4-piperidyl or 1,2,2,6,6-pentamethyl-4-piperidyl,
- and each of R18 and R19 may be the same as, or different from, each other and is 2,2,6,6-tetramethyl-4-piperidyl or 1,2,2,6,6-pentamethyl-4-piperidyl.
Dependencies are inferred from the claim text.