Patent ID: 7381684
Filing Date: 2008-06-03
Classification: B41M,G09F,Y10T

Abstract:
1. A method for using a rewritable thermal label of a non-contact type which comprises recording and erasing information repeatedly in accordance with a non-contact method on a rewritable thermal label which remains attached to an adherend, said label comprising: (a) an anchor coat layer comprising a crosslinked resin having a degree of crosslinking expressed as a gel fraction of 30% or more, said resin being selected from the group consisting of an acrylic resin, a polyester resin, a polyurethane resin and an ethylene-vinyl acetate copolymer which is crosslinked and said anchor coat layer being formed by using a coating fluid selected from the group consisting of a coating fluid without solvent, a coating fluid of an aqueous solution and an aqueous dispersion; (b) a heat-sensitive color development layer comprising a dye precursor and a reversible color developing agent, said heat-sensitive color development layer being formed using a coating fluid which is obtained by dissolving or dispersing said dye precursor and said reversible color developing agent in an organic solvent, said dye precursor being at least one compound selected from the group consisting of: (i) a triarylmethane compound selected from the group consisting of 3, 3-bis (4-dimethylaminophenyl)-6- dimethylaminophthalide, 3- (4-dimethylaminophenyl) -3- (1, 2-dimethylindol-3-yl) phthalide and 3- (4- diethylamino-2-ethoxyphenyl) -3- (1-ethyl- 2-methylindol-3-yl) 4-azaphthalide; (ii) a xanthene compound selected from the group consisting of Rhodamine B anilinolactam and 3-(N-ethyl-N-tolyl)amino-6- methyl-7-anilinofluorane; (iii) a diphenylmethane compound selected from the group consisting of 4, 4′-bis(dimethylaminophenyl) benzohydrylbenzyl ether and N-chlorophenylleukoauramine; (iv) a spiro compound selected from the group consisting of 3-methylspirodinaphthopyran and 3-ethylspirodinaphthopyran; and (v) a thiazine compound selected from the group consisting of benzoylleukomethylene blue and p-nitrobenzoylleukomethylene blue; said reversible color developing agent being at least one compound selected from the group consisting of 4- (N-methyl-octadecylsulfonylamino) phenol, N- (4-hydroxyphenyl) -N′-n-octadecylthiourea, N- ( 4-hydroxyphenyl) -N′-n-octadecylurea, N- (4-hydroxyphenyl) -N′-n-octadecylthioamide, N- 3- (4-hydroxyphenyl) -propionol-N′-octadecanohydrazide and 4′-hydroxy-4-octadecylbenzanilide; and wherein said reversible color developing agent is contained in an amount of 50 to 700 parts by weight per 100 parts by weight of the dye precursor; and (c) a light absorption and photo-thermal conversion layer comprising (i) at least one light absorbing agent selected from the group consisting of a cyanine coloring matter, a phthalocyanine coloring matter, an anthraquinone coloring matter, an azulene coloring matter, a squalylium coloring matter, a metal complex coloring matter, a triphenylmethane coloring matter and an indolenin coloring matter, and (ii) a binder curable by an ionizing radiation selected from the group consisting of ultraviolet light and an electron beam, said layer (c) being cured by said radiation; said layers (a), (b) and (c) being laminated on a first face of a substrate successively, said layer (a) being placed next to the substrate, and said layer (c) being an outermost layer; and (d) an adhesive layer placed on a second face of the substrate, said substrate being a film selected from the group consisting of a polystyrene film, an ABS resin film and a polvcarbonate film, and said substrate having a thickness of 10 to 500 μm.