JP2007185834A - Thermal recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal recording material which enables formation of an image having a clear contrast, without being affected by the quality of an adherend, enables maintenance of the image being stable with time in an every-day environment and further excels in recyclability. <P>SOLUTION: The thermal recording material has at least one thermal recording layer provided on one side of a support base and at least one micro suction cup layer on the other side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat-sensitive recording material capable of forming an image by controlling thermal energy.

  In general, a heat-sensitive recording material is provided with a heat-sensitive recording layer mainly comprising an electron-donating usually colorless or light-colored dye precursor and an electron-donating developer on a support. By heating with a pen, laser light or the like, the dye precursor and the developer react instantaneously to obtain a recorded image (see, for example, Patent Document 1).

  Further, as a heat-sensitive recording material capable of repeatedly recording and erasing an image, an electron-accepting compound that causes a reversible color change, that is, color development and decoloring, by heating a generally colorless to light-colored electron-donating dye precursor ( A reversible thermosensitive recording material capable of forming and erasing an image by controlling heat energy using a reversible developer is known (see, for example, Patent Document 2). According to this recording material, a high-contrast and high-sensitivity recorded image can be formed and erased many times, and is widely used for the purpose of visualizing information in the card in IC cards and magnetic cards. I came. However, since the lifetime of the visible information recording part of the thermal recording material and the invisible information recording part such as IC do not always match, even if one function can not be used due to damage or the like, the other function can be used sufficiently, Had to be discarded. In order to solve such problems, a card in which a heat-sensitive recording material is bonded to an invisible information recording material such as an IC card using a water-soluble adhesive has been put into practical use. However, since the adhesive remains on the invisible information recording material after the heat sensitive recording material is peeled off when the heat sensitive recording material is damaged or cannot be additionally recorded, sufficient cleaning is required.

  In addition, when pasted on a card with a normal adhesive, a reversible thermosensitive recording system that can be repeatedly erased due to the sticking of the adhesive when heated by a thermal head or the effect of deterioration due to heat. It was not suitable for the card and write-once type thermal card.

  On the other hand, recycling of molded products made of plastic resin is strongly desired under the increasingly serious environmental problems. In this recycling, polystyrene-based plastics such as polystyrene and ABS are very suitable in terms of physical properties. However, at the time of recycling, it is necessary to remove the label based on paper or polyester film in order to maintain the physical properties and appearance of the plastic. However, the work of removing the label from the plastic molded product is inefficient and has been a problem in promoting recycling. Then, the label which can be used for a reproduction | regeneration process is proposed, without adhering without removing from the to-be-adhered body, without impairing the physical property of the molded article after recycling (for example, refer patent documents 3-5).

Such a conventional label cannot be rewritten once the display content is printed. For example, if the resin molded product is a container, the display content of the label may display the content information together with the container information. In this case, the container can be used again after the contents have been replaced. However, since the information on the contents has changed, it has been necessary to recycle or replace the label only after being used once. Therefore, a recycling label that can record and erase information while being attached to a container and can be melted and recycled together with the container when recycling is proposed (for example, see Patent Document 6). However, if the adherend was broken first or deteriorated, it was necessary to recycle together even if the recycling label was sufficiently usable. Therefore, there has been a demand for a recyclable recording material that can be easily peeled off when it needs to be replaced without being easily peeled off by impact or friction once it is pasted.
Japanese Patent Publication No.43-4160 Japanese Patent Laid-Open No. 6-210954 JP-A-9-244534 Japanese Patent Laid-Open No. 10-105063 Japanese Patent Laid-Open No. 11-2374840 JP 2002-32843 A

  The problem of the present invention is that it is possible to form an image having a clear contrast without being affected by the thermal conductivity of the adherend, and to maintain a stable image over time in an environment of daily life. An object of the present invention is to provide a heat-sensitive recording material that retains adhesive force even when it is repeatedly applied to and peeled off from the body, and is excellent in recyclability without deposits on the adherend when peeled off.

  As a result of studying to solve these problems, the present inventors have found that the above-described problems can be solved by the following invention.

  A thermosensitive recording material, wherein at least one thermosensitive recording layer is provided on one side of a supporting substrate, and a micro sucker layer is provided on the other side.

  Alternatively, the heat-sensitive recording material is characterized in that at least one heat-sensitive recording layer is provided on a transparent support, and at least one micro suction layer is provided on the heat-sensitive recording layer.

  The heat-sensitive recording layer is preferably a reversible heat-sensitive recording layer.

  An object of the present invention is to enable formation of an image having a clear contrast without being affected by the thermal conductivity of the adherend, and to maintain an image that is stable over time in an environment of daily life. There is no sticking out of the adhesive or misalignment with the adherend due to multiple additions to the adherend, and the adhesive strength is maintained even after repeated pasting and peeling to the adherend, and the adherend when further peeled off It is to provide a heat-sensitive recording material excellent in recyclability with no deposits on the surface.

  The constituent elements of the present invention mainly comprise a support, a heat-sensitive recording layer, and a micro sucker layer. Furthermore, an undercoat layer such as a heat insulating layer or an anchor layer may be provided between the support and the heat-sensitive recording layer, and it is more preferable that these layers contain an ultraviolet absorber. On the heat-sensitive recording layer, it is preferable to provide a protective layer containing an ultraviolet absorber and a protective layer made of a curable resin. Moreover, you may bond a transparent film as a protective layer. When laminating a transparent film as a protective layer, an adhesive layer such as an adhesive or a pressure-sensitive adhesive may be used. The micro sucker layer is preferably provided on the side opposite to the thermosensitive recording layer, and a release paper may be provided thereon. Further, an adhesive layer may be provided between the support and the micro sucker layer. When the support is transparent, a micro suction layer can be provided on the uppermost layer on the same surface as the thermosensitive recording layer. In that case, it can adsorb | suck to the adherend with high smoothness, and can record from the surface of a transparent support body using a laser etc. Since the adherend to which the micro sucker layer adsorbs adheres by the action of a number of recessed suckers opened on the surface of the micro sucker layer, the adherend can be strongly bonded as the smoothness increases. Therefore, a preferable adherend is preferably a smooth resin, metal, surface-treated wood, laminated paper, coated paper, synthetic paper, or other highly smooth paper. If the surface of the adherend is not smooth, the surface of the heat-sensitive recording material can be adsorbed by creating a smooth surface by attaching a smooth material to the adherend with an adhesive or an adhesive. .

  The micro sucker layer according to the present invention is a synthetic resin foam having a large number of micro holes of several hundreds μm opened on the surface, and the surface opening becomes a micro sucker and adsorbs to the adherend. It is preferable to have a large number of independent bubbles inside, and the internal bubbles also improve the adhesion to the adherend and improve the adhesive strength. If the resin is hard, there is a cavity inside, and even if it has a micro opening on the surface, adhesive strength as a micro suction cup cannot be obtained. Preferred synthetic resin foams include foams such as acrylic resin, urethane resin, polyolefin resin, butadiene synthetic rubber, and mixtures thereof, and foams having self-adhesive strength. Foam mainly composed of acrylic resin. The body is preferable in terms of flexibility and adsorptivity. The size of the bubbles is preferably 200 μm or less, and even the largest bubble is preferably 300 μm or less. Moreover, it is preferable that each bubble is independent.

  The micro sucker layer is obtained by applying a foamed emulsion liquid containing fine bubbles mechanically to a synthetic resin on a base material using a foaming machine or the like, and drying the substrate. You may add a thickener, a foam stabilizer, a foaming agent, a crosslinking agent, etc. as needed.

  The micro sucker layer has no stickiness like ordinary adhesives and adhesives, has high adhesion stability, high chemical stability of the layer itself, and very little deterioration over time. . Furthermore, since the heat insulation effect is high compared to ordinary pressure-sensitive adhesives and adhesives, the color development sensitivity is improved and the sensitivity is not easily affected by the thermal conductivity of the adherend. Even when the material of the adherend is different, recording can be performed under the same energy condition while being attached to the adherend. Further, when used in an IC card, the micro sucker layer acts as a heat insulating and cushioning, and has an effect of reducing IC damage due to printing, and durability is improved.

  The thickness of the micro suction layer is preferably 30 μm to 1000 μm, more preferably 50 μm to 500 μm, and still more preferably 100 μm to 300 μm. When the thickness of the layer is 30 μm or less, the application may be limited without obtaining sufficient adsorption force. Further, since the layer is thin, the recording characteristics are easily affected by the thermal conductivity of the adherend. On the other hand, when the thickness of the film is 1000 μm or more, not only the improvement in adsorption performance and recording characteristics due to the increase in thickness can be expected, but also the weight of the recording material becomes heavy and can be caught by increasing the thickness of the entire recording material. It becomes easy to peel off, and the application is limited.

  For the heat-sensitive recording layer according to the present invention, a material whose color tone or transparency changes with heat can be used. For example, a heat-sensitive recording material capable of forming an image by controlling the thermal energy using a developer that usually changes color tone by heating a colorless or light leuco dye, and can record and erase images repeatedly. As a heat-sensitive recording material, a reversible heat-sensitive recording material that can form and erase images by controlling heat energy using a reversible developer that gives a reversible color change by heating to a leuco dye, or a resin matrix Examples of the material include low-molecular organic substances dispersed in a material, and a cloudy reversible heat-sensitive material that gives a transparent state and a cloudy state by heat. In addition, these heat-sensitive recording layers may be stacked with a plurality of heat-sensitive recording layers having different color tones.

  The heat-sensitive recording layer utilizing the color tone change of the leuco dye is composed mainly of a leuco dye, a developer (reversible developer), and a binder. Specific examples of the leuco dye include the following, but the present invention is not limited to this.

  3-diethylamino-7-o-chlorophenylaminofluorane, 3-diethylamino-7-m-chlorophenylaminofluorane, 3-diethylamino-7-p-chlorophenylaminofluorane, 3-diethylamino-7-o-fluorophenylamino Fluorane, 3-diethylamino-7-m-fluorophenylaminofluorane, 3-diethylamino-7-p-fluorophenylaminofluorane, 3-di-n-butylamino-7-m-chlorophenylaminofluorane, 3 -Di-n-butylamino-7-p-chlorophenylaminofluorane, 3-di-n-butylamino-7-o-fluorophenylaminofluorane, 3-di-n-butylamino-7-m-fluoro Phenylaminofluorane, 3-di-n-butylamino-7-p Fluorophenyl aminofluoran,

  3-diethylamino-6-methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-o-chlorophenylaminofluorane, 3-diethylamino-6-methyl-7-m-chlorophenylaminofluorane, 3 -Diethylamino-6-methyl-7-p-chlorophenylaminofluorane, 3-diethylamino-6-methyl-7-o-fluorophenylaminofluorane, 3-diethylamino-6-methyl-7-o-tolylaminofluorane 3-diethylamino-6-methyl-7-m-tolylaminofluorane, 3-diethylamino-6-methyl-7-p-tolylaminofluorane, 3-diethylamino-6-methyl-7-o-trifluoromethyl Phenylaminofluorane, 3-diethylamino-6-methyl-7-m Trifluoromethylphenylaminofluorane, 3-diethylamino-6-methyl-7-p-acetylphenylaminofluorane, 3-diethylamino-6-methoxy-7-phenylaminofluorane, 3-diethylamino-6-ethoxy-7 -Phenylaminofluorane,

  3-di-n-butylamino-6-methyl-7-phenylaminofluorane, 3-di-n-butylamino-6-methyl-7-o-tolylaminofluorane, 3-di-n-butylamino -6-methyl-7-m-tolylaminofluorane, 3-di-n-butylamino-6-methyl-7-p-tolylaminofluorane, 3-di-n-butylamino-6-methyl-7 -O-chlorophenylaminofluorane, 3-di-n-butylamino-6-methyl-7-m-chlorophenylaminofluorane, 3-di-n-butylamino-6-methyl-7-p-chlorophenylaminofluor Oran, 3-di-n-butylamino-6-methyl-7-o-fluorophenylaminofluorane, 3-di-n-butylamino-6-methyl-7-m-fluorophenylaminofluorane 3-di-n-butylamino-6-methyl-7-p-fluorophenylaminofluorane, 3-di-n-butylamino-6-methyl-7-o-trifluoromethylphenylaminofluorane, 3-di-n-butylamino-6-methyl-7-m-trifluoromethylphenylaminofluorane, 3-di-n-butylamino-6-methyl-7-p-trifluoromethylphenylaminofluorane, 3-di-n-butylamino-6-methoxy-7-phenylaminofluorane, 3-di-n-butylamino-6-ethoxy-7-phenylaminofluorane,

  3-di-n-pentylamino-6-methyl-7-phenylaminofluorane, 3-di-n-pentylamino-6-methyl-7-m-trifluoromethylphenylaminofluorane, 3-pyrrolidyl-6 -Methyl-7-phenylaminofluorane, 3-piperidyl-6-methyl-7-phenylaminofluorane, 3-N-methyl-N-isopentylamino-6-methyl-7-phenylaminofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-phenylaminofluorane, 3-N-methyl-Nn-butylamino-6-methyl-7-phenylaminofluorane, 3-N- Methyl-Nn-propylamino-6-methyl-7-phenylaminofluorane, 3-N-ethyl-N-isopentylamino-6-methyl-7-phen Ruaminofluorane, 3-N-ethyl-N-isopentylamino-6-methyl-7-o-chlorophenylaminofluorane, 3-N-ethyl-Np-tolylamino-6-methyl-7-phenylamino Fluorane, 3-N-ethyl-N- (4-ethoxybutyl) amino-6-methyl-7-phenylaminofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-octylamino Fluorane, 3-diethylamino-7-phenylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-chloro-7-methylfluorane, 3-diethylamino-7- (3,4-dichloroani Lino) fluorane, 3-diethylamino-7- (2-chloroanilino) fluorane,

  3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), 3,3-bis (p-dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3 -(1,2-dimethylindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3 -(2-Phenylindol-3-yl) phthalide, 3,3-bis (1,2-dimethylindol-3-yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindole) -3-yl) -6-dimethylaminophthalide, 3,3-bis (9-ethylcarbazol-3-yl) -5-dimethylaminophthalide, 3,3 Bis (2-phenylindole-3-yl) -5-dimethylaminophthalide, 3-p-dimethylaminophenyl-3- (1-methylpyrrole-2-yl) -6-dimethylaminophthalide,

  3- (2-Ethoxy-4-aminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-methylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-ethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl)- 4-Azaphthalide, 3- (2-ethoxy-4-propylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-hexylamino) Phenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-dimethylaminophenyl) -3- (1-ethyl-2-methyl) Ndol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2- Ethoxy-4-dipropylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-dihexylaminophenyl) -3- (1- Ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-phenylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide , 3- (2-Ethoxy-4-pyridylphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (3-ethoxy-4-di Chill aminophenyl) -3- (1-ethyl-2-methylindole-3-yl) -4-azaphthalide,

  3- (2-Methyl-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethyl-4-diethylaminophenyl) -3- ( 1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-propyl-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4- Azaphthalide, 3- (2-butyl-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-pentyl-4-diethylaminophenyl) -3 -(1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-hexyl-4-diethylaminophenyl) -3- (1-ethyl-2- Tilindole-3-yl) -4-azaphthalide, 3- (2-cyclohexyl-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2 -Cyano-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-nitro-4-diethylaminophenyl) -3- (1-ethyl- 2-methylindol-3-yl) -4-azaphthalide, 3- (2-chloro-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-Bromo-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-methyl-4 Diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (2-methylindol-3-yl) -4-Azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-methyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) ) -3- (1-propyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-butyl-2-methylindole-3- Yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-pentyl-2-methylindol-3-yl) ) -4-azaphthalide,

  3- (2-Ethoxy-4-diethylaminophenyl) -3- (1-hexyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- ( 1-heptyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-octyl-2-methylindol-3-yl) -4- Azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-nonyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3 -(1-Isopropyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- 1-isobutyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-isopentyl-2-methylindol-3-yl) -4- Azaphthalide,

  3- (2-Ethoxy-4-diethylaminophenyl) -3- (1-methyl-2-ethylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- ( 1-ethyl-2-propylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-butylindol-3-yl) -4- Azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-pentylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3 -(1-Ethyl-2-hexylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1- Til-2-isopropylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-isobutylindol-3-yl) -4-azaphthalide, 3- (2-Ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4-azaphthalide, 3,3-bis- (4-diethylamino-2-ethoxyphenyl) -4-azaphthalide,

  4,4'-bis (dimethylaminophenyl) benzhydrylbenzyl ether, N-chlorophenyl leucooramine, N-2,4,5-trichlorophenyl leucooramine, benzoyl leucomethylene blue, p-nitrobenzoyl leucomethylene blue, 3 -Methylspirodinaphthopyrans, 3-ethylspirodinaphthopyrans, 3,3'-dichlorospirodinaphthopyrans, 3-benzylspirodinaphthopyrans, 3-methylnaphthyl (3-methoxybenzo) spiropyrans, 3-propylspiros Examples include benzopyran.

  Specific examples of the dye precursor that forms a recorded image having absorption in the near infrared region of 700 to 1200 nm are given below.

  3,6-bis (dimethylamino) fluorene-9-spiro-3 '-(6'-dimethylamino) phthalide, 3,6-bis (diethylamino) fluorene-9-spiro-3'-(6'-diethylamino) Fluorene compounds such as phthalide, 3,3-bis [2 '-(p-dimethylaminophenyl) -2'-(p-methoxyphenyl) vinyl] -4,5,6,7-tetrachlorophthalide, 3 , 3-bis [2 '-(p-dimethylaminophenyl) -2'-(p-methoxyphenyl) vinyl] -4,5,6,7-tetrabromophthalide, 3,3-bis [2'- (P-methoxyphenyl) -2 '-(p-pyrrolidinophenyl) vinyl] -4,5,6,7-tetrachlorophthalide, bis (p-dimethylaminostyryl) -p-toluenesulfonylmethane, bi (P-diethylaminostyryl) -p-toluenesulfonylmethane, bis (p-dimethylaminostyryl) -benzenesulfonylmethane, 1,1-bis [2 ', 2'-(p-dimethylaminophenyl) vinyl] -2, Divinyl compounds such as 2-dinitrileethane;

2-methyl-6-p- (p-dimethylaminophenyl) aminoanilinofluorane, 2-methoxy-6-p- (p-dimethylaminophenyl) aminoanilinofluorane, 2-chloro-6-p- (P-dimethylaminophenyl) aminoanilinofluorane, 2-diethylamino-6-p- (p-diethylaminophenyl) aminoanilinofluorane, 2-phenyl-6-p- (p-phenylaminophenyl) aminoani Linofluorane, 2-benzyl-6-p- (p-phenylaminophenyl) aminoanilinofluorane, 3-diethylamino-6-p- (p-diethylaminophenyl) aminoanilinofluorane, 2-chloro-3 -Methyl-6-p- (p-phenylaminophenyl) aminoanilinofluorane and the like.

  The above leuco dyes may be used alone or in combination of two or more in one layer. Toning can also be performed by mixing leuco dyes that develop colors in other hues.

  Examples of the developer used in the present invention include those listed below, but the present invention is not limited thereto.

  p-phenylphenol, p-hydroxyacetophenone, 4-hydroxy-4'-methyldiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-4'-benzenesulfonyloxydiphenylsulfone, 1,1- Bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydroxyphenyl) hexane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1, 1-bis (4-hydroxyphenyl) cyclododecane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) hexane, 2,2-bis (4-hydroxyphenyl) octane 1,1-bis (4-hydroxyphenyl) -2-e Ruhexane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,3-bis (2- (4-hydroxyphenyl) -2-propyl) benzene, 1,3-bis (2- (3,4-dihydroxyphenyl) -2-propyl) benzene, 1,4-bis (2- (4-hydroxyphenyl) -2-propyl) benzene 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylsulfone, 2,4'-dihydroxydiphenylsulfone, 3,3'-dichloro-4,4'-dihydroxydiphenylsulfone, 3,3'-diallyl- 4,4'-dihydroxydiphenylsulfone, 3,3'-dichloro-4,4'-dihydroxydiphenylsulfide, 2 2-bis (4-hydroxyphenyl) acetate methyl, 2,2-bis (4-hydroxyphenyl) acetate butyl, 4,4'-thiobis (2-t-butyl-5-methylphenol), p-hydroxybenzoic acid Examples include benzyl, dimethyl 4-hydroxyphthalate, benzyl gallate, stearyl gallate, salicylanilide, 5-chlorosalicylanilide and the like. These can be used alone or in admixture of two or more.

  The reversible developer used in the present invention is preferably a compound represented by the following general formula (1), but the present invention is not limited thereto.

In the compound represented by the general formula (1), X ¹ and X ² may be the same or different from each other, and an oxygen atom, a sulfur atom, or a —CONH— bond that does not contain a hydrocarbon group at both ends Represents a divalent group as the smallest structural unit. R ¹ represents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms. R ² represents a divalent hydrocarbon group having 1 to 18 carbon atoms. A divalent hydrocarbon group having 1 to 4 carbon atoms is preferred. R ³ represents a monovalent hydrocarbon group having 1 to 24 carbon atoms, preferably a hydrocarbon group having 6 to 24 carbon atoms, and more preferably a hydrocarbon group having 8 to 24 carbon atoms. Furthermore, the case where the sum of the carbon numbers of R ¹ , R ² and R ³ is 11 or more and 35 or less is particularly preferable. R ¹ , R ² and R ³ mainly represent an alkylene group and an alkyl group, respectively. In the case of R ¹ , it may contain an aromatic ring. f represents an integer of 0 to 4, and when f is 2 or more, R ² and X ^{2 that} are repeated may be the same or different.

X ¹ and X ² in the general formula (1) include a divalent group having a minimum structural unit of a —CONH— bond that does not include a hydrocarbon atom group at both ends. Specific examples thereof include diacylamine ( -CONHCO-), diacylhydrazine (-CONHNHCO-), oxalic acid diamide (-NHCONCONH-), urea (-NHCONH-), acylurea (-CONHCONH-, -NHCONHCO-), semicarbazide (-NHCONHNH-, -NHNHCONH- ), Acyl semicarbazide (—CONHNHCONH—, —NHCONHNHCO—), diacylaminomethane (—CONHCH ₂ NHCO—), 1-acylamino-1-ureidomethane (—CONHCH ₂ NHCONH—, —NHCONHCH ₂ NHCO—), malonamide (— NHCOC ₂ CONH -), 3- acyl carba Jin ester (-CONHNHCOO -, - OCONHNHCO-) although groups such like, preferably a diacyl hydrazine, oxalic acid diamide, acyl semicarbazide.

  Specific examples of the reversible developer used in the present invention include the following structural formulas (1-1) to (1-16), but the present invention is not limited thereto.

  Each of the reversible developers used in the present invention may be used alone or in combination of two or more. The amount used is usually 5 to 5000% by mass, preferably 10 to 10%, based on a colorless or light leuco dye. 3000% by mass.

  Examples of the support according to the present invention include paper, non-woven fabric, plastic film, synthetic paper, metal plate, metal stay, and glass. The plastic film used in the present invention includes polyester film, polyolefin film, polyvinyl alcohol film, polyvinyl chloride film, nylon film, polystyrene film, polyvinylidene chloride film, ethylene vinyl acetate copolymer film, and ethylene vinyl alcohol copolymer. A film, a fluororesin film, a polyimide film, an aromatic polyamide film, an acrylic resin film, and the like can be mentioned. A polyester film is preferable in terms of mechanical strength, smoothness, water resistance, solvent resistance, and heat resistance. These synthetic resin materials may be used alone or in a blend, and may have cavities inside the resin to the extent that the mechanical strength is not impaired. Further, a pigment can be kneaded into these synthetic resins and used, for example, like a white plastic sheet. A composite sheet combining paper, various non-woven fabrics, woven fabric, synthetic resin film, synthetic resin laminated paper, synthetic paper, metal foil, glass and the like can be arbitrarily used depending on the purpose. In particular, when using a substrate whose surface is not sufficiently smooth, such as paper or nonwoven fabric, it is preferable to use it laminated with a synthetic resin. Further, it may be transparent, translucent or opaque.

  Examples of the polyester film include polyethylene terephthalate (PET), polybutylene terephthalate, poly-1,4-cyclohexanedimethylene terephthalate, polyxylylene terephthalate, polyethylene isophthalate, and polyethylene-2,6-naphthalate (PEN). It is done. Preferred polyester films include PET films or PEN films that are excellent in toughness, heat resistance, chemical resistance, dimensional stability, transparency, and electrical insulation.

  Next, although the specific manufacturing method of the thermosensitive recording material of this invention is described, this invention is not limited to this.

  As a specific example of the method for producing the heat-sensitive recording layer used in the present invention, a method of forming a heat-sensitive recording layer by usually coating a colorless or light leuco dye or a developer as a main component and applying or printing these on a support. Is mentioned.

  As a method of adding a colorless or light leuco dye or developer (reversible developer) to the heat-sensitive recording layer, a method in which each compound is dissolved in a solvent alone or dispersed in a dispersion medium and then mixed, Each compound is mixed and then dissolved in a solvent or dispersed in a dispersion medium, each compound is dissolved by heating, homogenized, cooled, and dissolved in a solvent or dispersed in a dispersion medium. A layer can be formed by drying after coating or printing on a support.

  It is also possible to add a binder to the thermal recording layer for the purpose of improving the strength of the thermal recording layer. Specific examples of the binder include starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, polyvinyl alcohol, modified polyvinyl alcohol, sodium polyacrylate, acrylic acid amide / acrylic acid ester copolymer, acrylic acid amide / acrylic. Acid ester / methacrylic acid terpolymer, alkali salt of styrene / maleic anhydride copolymer, alkali salt of ethylene / maleic anhydride copolymer, polyvinyl acetate, polyurethane, polyacrylic ester, styrene / butadiene copolymer Polymer, acrylonitrile / butadiene copolymer, methyl acrylate / butadiene copolymer, ethylene / vinyl acetate copolymer, ethylene / vinyl chloride copolymer, polyvinyl chloride, ethylene / vinylidene chloride Polymers, polyvinylidene chloride, polycarbonates, polyvinyl butyral, and the like. The role of these binders is to keep the materials of the composition uniformly dispersed without being displaced by the application of heat for printing and erasing. Therefore, it is preferable to use a resin having high heat resistance for the binder. Recently, high value-added reversible thermosensitive recording materials such as prepaid cards and stored cards are often used, and accordingly, highly durable products such as heat resistance, water resistance, and adhesiveness are required. It is becoming. For such a requirement, a curable resin is particularly preferable.

  Examples of the curable resin include a thermosetting resin, an electron beam curable resin, and an ultraviolet curable resin. Examples of the thermosetting resin include those that are cured by reacting a hydroxyl group or a carboxyl group with a crosslinking agent, such as phenoxy resin, polyvinyl butyral resin, and cellulose acetate propionate resin. Examples of the crosslinking agent at this time include isocyanates, amines, phenols, epoxies, and the like.

  Monomers used for electron beams and ultraviolet curable resins include monofunctional monomers, bifunctional monomers, polyfunctional monomers, and the like typified by acrylics. A polymerization accelerator is used.

  When laminating each layer, it is preferable that the uppermost layer at the coating stage is hardly soluble in the solvent of the layer to be applied next. For this purpose, when a curable resin is used, it is preferable to stack the next layer after sufficiently curing. In particular, when the uppermost layer in the coating step is a layer containing a leuco dye and has no solvent resistance, it is more preferable to provide a layer (intermediate layer) that prevents the leuco dye from migrating to the next layer. In that case, the intermediate layer is preferably transparent.

  In order to prevent aging of the heat-sensitive recording material, an anti-aging agent that is also used in rubber products and the like can be added. Moreover, an anti-aging agent can be contained in the upper layer or the lower layer of the heat-sensitive recording layer.

  Antiaging agents include amine compounds such as p, p'-diaminodiphenylmethane, aldol-α-naphthylamine, N, N'-diphenyl-p-phenylenediamine, hydroquinone monobenzyl ether, 1,1-bis (p-hydroxy Phenolic compounds such as phenyl) cyclohexane, benzotriazole compounds such as 2,2′-methylenebis [6- (2H-benzotriazol-2-yl) -4- (2-hydroxymethyl) phenol], triazine compounds, benzophenone compounds, Examples include benzoic acid esters. In addition, o-phenylenethiourea, zinc salt of 2-aminobenzimidazole, nickel dibutylthiocarbamate, zinc oxide, paraffin and the like can be mentioned. In addition, a polymer containing these monomers having an anti-aging structure as a component of polymerization, and a polymer main chain grafted with an anti-aging structure can also be used. Two or more types of anti-aging agents can be used in combination.

  In addition, a heat-fusible substance can be contained in the heat-sensitive recording layer as an additive for adjusting the color development sensitivity of the heat-sensitive recording layer. Those having a melting point of 60 ° C. to 200 ° C. are preferred, and those having a melting point of 80 ° C. to 180 ° C. are particularly preferred. Sensitizers used for general heat-sensitive recording paper can also be used. For example, waxes such as N-hydroxymethyl stearamide, stearamide, and palmitic acid amide, naphthol derivatives such as 2-benzyloxynaphthalene, biphenyl derivatives such as p-benzylbiphenyl and 4-allyloxybiphenyl, 1,2 -Polyether compounds such as bis (3-methylphenoxy) ethane, 2,2'-bis (4-methoxyphenoxy) diethyl ether, bis (4-methoxyphenyl) ether, diphenyl carbonate, dibenzyl oxalate, bis (oxalate) ( Carbonic acid or oxalic acid diester derivatives such as p-methylbenzyl ester can be used in combination.

  When recording and erasing images using a laser such as a semiconductor laser or YAG laser, or a light source such as a tungsten lamp or a halogen lamp, the sensitivity is improved by including a photothermal conversion material in the thermal recording layer or in a nearby layer. be able to.

  Specific examples of the photothermal conversion dye used in the present invention include phthalocyanine compounds, metal complex compounds, polymethine compounds, naphthoquinone compounds, and the like, which can be contained in the thermal recording layer in a dispersed state or in a molecular state. . Preferable photothermal conversion dyes include phthalocyanine compounds and metal complex compounds in terms of photothermal conversion efficiency, solubility in solvents, dispersibility in resins, and light resistance to ultraviolet light, and phthalocyanine compounds are particularly preferable. When the photothermal conversion layer is provided close to the thermosensitive recording layer, a photothermal conversion layer made of a metal film such as a copper thin film or ITO can also be used.

  Examples of phthalocyanine compounds include naphthalocyanine compounds, metal-free phthalocyanine compounds, iron phthalocyanine compounds, copper phthalocyanine compounds, zinc phthalocyanine compounds, nickel phthalocyanine compounds, vanadyl phthalocyanine compounds, indium chloride phthalocyanine compounds, tin phthalocyanine compounds, and more preferably. Are vanadyl phthalocyanine compounds, zinc phthalocyanine compounds, and tin phthalocyanine compounds. The phthalocyanine compound used in the present invention may have a substituent on the aromatic ring for the purpose of adjusting the absorption wavelength, improving the solubility in a solvent, improving light resistance, and the like. Examples of the substituent include an alkyl ether group, an alkyl thioether group, an aryl ether group, an aryl thioether group, an amide group, an amino group, an alkyl ester group, an aryl ester group, a chlorine atom, and a fluorine atom. When the aromatic ring has two or more substituents, they may be the same or different, and the substituents may be bonded to form a ring.

  The amount of the photothermal conversion dye used is preferably set so that the absorbance at the oscillation wavelength of the light source used is 0.2 or more. If it is less than this amount, sufficient heat generation cannot be obtained, and the recording sensitivity is lowered. On the other hand, the photothermal conversion dye has some absorption in the visible region, and if the amount used is too large, the contrast is lowered. It is preferable to set an upper limit for the amount of photothermal conversion dye used so that an average transmittance of 400 nm to 700 nm can be secured by 60% or more. Two or more kinds of photothermal conversion dyes can be mixed and used.

  The photothermal conversion pigment is preferably contained in at least one of the same layer or adjacent layers with respect to the layer containing the leuco dye and the developer (reversible developer), and is contained in the same layer. It is more preferable to obtain good sensitivity.

  In the case of using a photothermal conversion dye, it is preferable to provide a protective layer containing an ultraviolet absorber, and it is preferable to provide it so that the light strikes before the reversible thermosensitive recording layer and the layer containing the photothermal conversion dye. Furthermore, a hard coat layer such as an ultraviolet curable resin may be provided on the protective layer containing the ultraviolet absorber.

  Examples of the ultraviolet absorber include benzotriazole compounds, triazine compounds, benzophenone compounds, benzoic acid esters and the like. In addition, o-phenylene thiourea, zinc salt of 2-aminobenzimidazole, nickel dibutylthiocarbamate, zinc oxide and the like can be mentioned. Preferred ultraviolet absorbers include benzotriazole compounds and zinc oxide. Further, it is more preferable to use a polymer containing a monomer having the structure of the ultraviolet absorber as a component of polymerization, or a polymer obtained by grafting the structure of the ultraviolet absorber on the polymer main chain. Two or more kinds of ultraviolet absorbers can also be used in combination.

  Specific examples of the benzotriazole compound include 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole, 5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl) ) -2H-Benzotriazole, 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4- (2-hydroxymethyl) phenol].

  In the heat-sensitive recording layer according to the present invention, the other layer, the surface on which the heat-sensitive recording layer is provided, the opposite surface, or the like may contain a material capable of recording information electrically, magnetically, or optically. Further, the support may be formed of a plurality of layers, and an IC chip may be sandwiched therebetween. Further, an antistatic layer can be provided on the surface of the layer or between the layers for the purpose of preventing the charge.

  When the IC chip is encapsulated between the layers of the heat-sensitive recording material, it can be encapsulated between the layers of the plastic film or between the paper substrate and the plastic film. It is preferable from the viewpoint of print quality that sealing is performed between layers away from the heat-sensitive recording layer.

  When a non-contact IC chip is encapsulated, it can be encapsulated with an antenna. A cushion layer can be provided for the purpose of preventing the IC chip from being damaged by the pressure during encapsulation. When the thickness of the cushion layer is less than 10 μm, the cushioning property is insufficient, and therefore, the thickness is preferably 10 μm or more. When the area is small, the pressure applied to the IC chip increases. preferable. The cushion layer can be provided on one side or both sides. More preferably, cushion layers are provided on both sides. As the cushion layer, a thermoplastic resin is preferable. Foamed resin has better cushioning properties and can prevent damage to the IC chip.

  In addition, the thermal recording layer, protective layer, and undercoat layer include diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide, aluminum hydroxide, urea-formalin resin, etc. Pigments, other higher fatty acid metal salts such as zinc stearate and calcium stearate, waxes such as paraffin, oxidized paraffin, polyethylene, polyethylene oxide, stearamide, and castor wax, dispersants such as sodium dioctylsulfosuccinate, surface activity An agent, a fluorescent dye, and the like can also be included.

  In the heat-sensitive recording material of the present invention, an appropriate heat source (thermal head, laser light, heat roll, heat stamp, high-frequency heating, electric heater, light source such as a tungsten lamp or a halogen lamp, etc.) is used to form a color recording image. Radiant heat, hot air, etc.) to a temperature at which the dye and developer melt, and then cooled to room temperature.

  In addition, as a method of recording an image of a reversible heat-sensitive material that gives a transparent state and a white turbid state by heat, the above-mentioned heat source is used, and after heating to a temperature range in which a small organic molecule dissolves and becomes transparent By cooling to room temperature, a transparent image is formed, and after applying heat in a temperature region or more that becomes transparent, a cloudy image can be obtained by cooling.

  Also, in the case of a reversible thermosensitive recording material using a leuco dye, rapid cooling must occur subsequent to heating to form a color recording image, and cooling after heating is necessary to erase the recorded image. It only needs to be slow. For example, after heating by an appropriate method, a colored state can be developed by rapidly cooling by pressing a low-temperature metal block or the like. Further, when heating is performed for a very short time using a thermal head, laser light, or the like, it is cooled immediately after the heating is completed, so that the colored state can be maintained. On the other hand, if it is heated for a relatively long time with an appropriate heat source (thermal head, laser beam, heat roll, heat stamp, high-frequency heating, electric heater, radiant heat from a light source such as a tungsten lamp or a halogen lamp, hot air, etc.) Since not only the recording layer but also the support or the like is heated, even if the heat source is removed, the cooling rate is slow, and the color is lost. Therefore, even when the same heating temperature and / or the same heat source are used, the coloring state and the decoloring state can be arbitrarily expressed by controlling the cooling rate.

  In the present invention, preferred examples of lasers used for image recording and erasing include semiconductor lasers, YAG lasers, carbon dioxide lasers, and the like. In the case of erasing an image, it is more preferable to use a laser beam having a wavelength of 800 nm or more for the purpose of reducing the deterioration of the leuco dye because the leuco dye that is colored is irradiated with the laser beam.

  Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to these examples. In addition, the number of parts in an Example is a mass reference | standard.

Example 1
[Preparation of thermal recording material]
Blue coloring leuco dye (Yamamoto Kasei Co., Ltd., BL-63) 20 parts, N- [3- (p-hydroxyphenyl) propiono] -N'-n-docosanohydrazide 100 parts, N- [1- ( 4-methyl) piperazinyl] -N'-octadecylurea 10 parts, polyester polyol (Dainippon Ink Chemical Co., Ltd., Vernock D-293-70), curing agent (Nippon Polyurethane Industry Co., Ltd., Coronate) HL) 40 parts, a curing agent (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L), 300 parts of methyl ethyl ketone, and 300 parts of toluene were added and pulverized with a glass bead for 5 hours with a paint shaker to obtain dispersion A It was. The above dispersion was applied to a 75 μm transparent polyethylene terephthalate film (transparent PET film) to a dry film thickness of 6 μm and dried to provide a thermosensitive recording layer.

  Next, 2,2'-methylenebis [6- (2H-benzotriazol-2-yl) -4- (2-hydroxymethyl) phenol] 10 parts, polyester polyol (Dainippon Ink & Chemicals, Burnock) 50 parts of D-293-70), 50 parts of a curing agent (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate HL), 300 parts of methyl ethyl ketone, and 300 parts of toluene together with glass beads for 5 hours with a paint shaker to disperse the UV absorber Liquid B was obtained. This liquid was applied on the heat-sensitive recording layer so as to have a dry film thickness of 1 μm, whereby a protective layer 1 was obtained.

  Furthermore, a 20% isopropyl alcohol solution of an acrylate-based ultraviolet curable resin was applied so that the film thickness after drying and curing was 2 μm, and cured with ultraviolet rays to provide a protective layer 2 to obtain a thermal recording sheet A.

  Next, a pressure sensitive adhesive (A Toyo Ink Manufacturing Co., Ltd., BPS5762, a hardener BXX5627 manufactured by Toyo Ink Co., Ltd.) was provided on the other pet surface so as to have a thickness of 20 μm to obtain a thermal recording pressure sensitive adhesive sheet A.

  Furthermore, the synthetic paper surface of the micro sucker sheet film (Diamic Co., Ltd., Diafit MQ-024: polyethylene release film, 100 μm micro sucker layer, 115 μm synthetic paper laminated in this order) and the thermal recording adhesive. The pressure-sensitive adhesive layer of sheet A was bonded to obtain the heat-sensitive recording material of Example 1. After the obtained sheet was cut into 80 mm × 50 mm, the release paper was peeled off and bonded to a 500 μm JIS card size vinyl chloride card (vinyl chloride card) to obtain a card of Example 1.

Example 2
Instead of the micro sucker sheet film of Example 1, a micro sucker sheet film having a 180 μm micro sucker layer (manufactured by Diamic Co., Ltd., Diafit MQ-010: polypropylene release film, 180 μm micro sucker layer, 125 μm Example 2 is the same as Example 1 except that a white PET film, a sheet laminated in the order of 5 μm coating layer) is used, and the surface of the coating layer and the adhesive layer of the thermosensitive recording adhesive sheet A are bonded together. A heat-sensitive recording material was obtained. The obtained sheet was cut into 80 mm × 50 mm, and then the release paper was peeled off and bonded to a 400 μm JIS card size PVC card to obtain a card of Example 2.

Example 3
A micro sucker sheet film having a 220 μm micro sucker layer instead of the micro sucker sheet film of Example 1 (Diamic Co., Ltd., Diafit MQ-021: 127 μm release paper, 220 μm micro sucker layer, 100 μm synthetic paper The heat-sensitive recording material of Example 3 was obtained in the same manner as in Example 1 except that the sheet was laminated with the adhesive layer of the synthetic paper surface and the heat-sensitive recording adhesive sheet A. The obtained sheet was cut into 80 mm × 50 mm, and then the release paper was peeled off and bonded to a 400 μm JIS card size PVC card to obtain a card of Example 3.

Example 4
A micro sucker sheet film having a 300 μm micro sucker layer instead of the micro sucker sheet film of Example 1 (Diamic Co., Ltd., Diafit MQ-005: 127 μm release paper, 300 μm micro sucker layer, 50 μm PET film The heat-sensitive recording material of Example 4 was obtained in the same manner as in Example 1 except that the PET film surface and the adhesive layer of the heat-sensitive recording adhesive sheet A were bonded together. The obtained sheet was cut into 80 mm × 50 mm, and then the release paper was peeled off and bonded to a 400 μm JIS card size PVC card to obtain a card of Example 4.

Example 5
A heat-sensitive recording material of Example 5 was obtained in the same manner as in Example 4 except that 0.2 parts of photothermal conversion dye (YKR3070 manufactured by Yamamoto Kasei) was added to the heat-sensitive recording layer dispersion A before dispersion. The obtained sheet was cut into 80 mm × 50 mm, and then the release paper was peeled off and bonded to a 400 μm JIS card size PVC card to obtain a card of Example 5.

Example 6
Example similar to thermal recording sheet A of Example 1 except that a thermal recording layer was provided on the PET surface of a micro sucker sheet film (Diamic Co., Ltd., Diafit MQ-005) instead of transparent PET. 6 was obtained. The obtained sheet was cut into 80 mm × 50 mm, and then the release paper was peeled off and bonded to a 500 μm JIS card size PVC card to obtain a card of Example 6.

Example 7
A heat-sensitive recording sheet of Example 7 was prepared in the same manner as heat-sensitive recording sheet A of Example 1 except that 1 part of photothermal conversion dye (YKR3070, manufactured by Yamamoto Kasei) was added to heat-sensitive recording layer dispersion A. The heat-sensitive recording material of Example 7 was obtained by providing the agent on the protective layer 2 and bonding the protective layer 2 and the PET film surface of the micro-adsorption sheet film through an adhesive.

Example 8
[Preparation of thermal recording material]
6 parts of stearic acid, 4 parts of eicosane diacid, 2 parts of diisodecyl phthalate, 20 parts of vinyl chloride / vinyl acetate / phosphorus ester copolymer (manufactured by Denki Kagaku Kogyo Co., Ltd., Denkavidil # 1000P), 150 parts of tetrahydrofuran, toluene 15 The coating solution to which each part was added was applied to the PET surface of a micro sucker sheet film (Diamic Co., Ltd., Diafit MQ-005) to a dry film thickness of 15 μm, and dried to provide a thermosensitive recording layer. It was.

  Next, using a solution consisting of 5 parts of polyamide resin (CM8000, manufactured by Toray Industries, Inc.) and 90 parts of methyl alcohol, it was applied on the heat-sensitive recording layer to a dry film thickness of 0.3 μm, and protective layer A was applied. Provided. Further, a 20% butyl acetate solution of a urethane acrylate UV curable resin was coated thereon so that the film thickness after drying and curing was 3 μm, and cured with UV to obtain a heat-sensitive recording material of Example 8. . After the obtained sheet was cut into 80 mm × 50 mm, the release paper was peeled off and bonded to a 500 μm JIS card size PVC card to obtain a card of Example 8.

Comparative Example 1
The heat-sensitive recording material of Comparative Example 1 was obtained by laminating the PET surface of the heat-sensitive recording sheet A of Example 1 with a weak adhesive double-sided tape (manufactured by Nichiban Co., Ltd., Nystack Rimka) so that there was no gap. The obtained sheet was cut into 80 mm × 50 mm, and then the release paper was peeled off and bonded to a 700 μm JIS card size PVC card to obtain a card of Comparative Example 1.

Comparative Example 2
A heat-sensitive recording material of Comparative Example 2 was obtained in the same manner as in Example 5 except that a weak adhesive double-sided tape (manufactured by Nichiban Co., Ltd., Nystack Rimka) and a protective layer surface were bonded together instead of the micro-sucker sheet film.

[Print erasure test 1]
The cards of Examples 1 to 6 and 8 and Comparative Example 1 were erased 10 times with the standard energy of the card reader / writer (manufactured by Panasonic Communications Co., Ltd.), and the pattern printing erasure was repeated 10 times, and the thermal recording material was peeled off once and then pasted. Repaired. Similarly, the operation of erasing and pasting and peeling off was repeated 30 times. In Examples 1 to 6 and 8, there was almost no decrease in print density, and good color development and erasure could be repeated. Moreover, the operation of peeling and sticking could be performed easily, there was no decrease in the adsorption power, and there was no deposit on the PVC card. On the other hand, although Comparative Example 1 was able to erase the printing without any problem, the adhesive force gradually decreased, and the amount of the adhesive to the PVC card increased each time the printing was repeated.

[Print erase test with laser]
The heat-sensitive recording materials of Examples 5 and 7 and Comparative Example 2 were attached to a 250 μm PET film, and letters from A to F were printed with a line of about 60 μm at an energy of about ² J / cm ² using a semiconductor laser having a wavelength of 800 nm. And then erased with an energy of 0.8 J / cm ² . As a result, any sample could be printed and erased. Next, these heat-sensitive recording materials were attached to a 1 mm thick stainless steel plate, and the same operation was performed. As a result, Examples 5 and 7 were able to be printed and erased in the same manner as when pasted on a PET film. On the other hand, Comparative Example 2 could not sufficiently develop the color, and furthermore, the erasure was insufficient. The stainless steel plate has higher thermal conductivity than the PET film, but Examples 5 and 7 have a highly heat-insulating micro sucker layer, so printing and erasing are hardly affected by the adherend. Was able to do. On the other hand, compared with Examples 5 and 7, Comparative Example 2 was not sufficiently heat-insulating, resulting in a strong difference in the thermal conductivity of the adherend.

Example 9
(1) Preparation of coating liquid Dispersions C to F were prepared by the following method.

<C liquid preparation>
30 parts of 4,4′-bisphenolsulfone was dispersed in a mixture of 20 parts of a 10% sulfone group-modified polyvinyl alcohol aqueous solution and 50 parts of water, and pulverized with a bead mill until the average particle size became 0.7 μm.

<D liquid preparation>
10 parts of an isocyanate compound (Takenate WD-725, manufactured by Mitsui Takeda Chemical Co., Ltd.) was dispersed in 90 parts of water, and dispersed with a Pomo mixer at 4000 rpm for 15 minutes.

<E liquid preparation>
20 parts of 2,2'-methylenebis [6- (2H-1,2,3-benzotriazol-2-yl) -4-n-octylphenol] is mixed with 20 parts of a 10% sulfone group-modified polyvinyl alcohol aqueous solution and 60 parts of water. The mixture was dispersed in the mixture and pulverized with a bead mill until the average particle size became 0.7 μm.

<F liquid preparation>
A mixture of 10 parts of 3-diethylamino-6-methyl-7-anilinofluorane, which is a black-colored electron-donating dye precursor, dissolved in 20 parts of methyl methacrylate and 70 parts of a 5% aqueous solution of polyvinyl alcohol is mixed. Dispersion with a mixer gave a dye precursor dispersion. The particle size of the dispersion was measured with a MICROTRAC particle size analyzer (Series 9200 FRA; manufactured by Leeds & Northrup Instruments) and found to have a volume average particle size of 2.5 μm. Next, this dispersion was transferred to a polymerization vessel, and 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator was added thereto, and the temperature was raised to 70 ° C. with stirring, followed by polymerization for 6 hours. I let you. Next, this was cooled to room temperature to obtain a dispersion of electron-donating dye precursor particles having a color adjusting layer on the surface.

Next, a heat-sensitive layer recording coating solution B and a protective layer coating solution B were prepared.
<Thermosensitive recording layer coating solution B>
10 parts of F liquid as a dye, 7 parts of C liquid as a developer, 10 parts of polyurethane resin (Takelac W-6061, manufactured by Mitsui Takeda Chemical Co.) as a binder resin, and 6 parts of D liquid in which an isocyanate compound is dispersed Water was added so as to have a concentration of 15%, followed by stirring to obtain a heat-sensitive layer recording coating solution B.

<Protective recording layer coating solution B>
10 parts of E solution as UV absorber, 100 parts of silicon-modified acrylic resin (Watersol WSA-910, manufactured by Dainippon Ink and Chemicals) as binder resin, potassium zirconium carbonate (Zirmel 1000, manufactured by Nippon Light Metal Co., Ltd.) as a film forming aid ) 10 parts were mixed, and water was added so that the coating solution concentration was 15%, followed by stirring to obtain a protective layer coating solution B.

(2) Production of heat-sensitive recording material The produced heat-sensitive layer coating solution was applied to the polyester surface of a micro sucker sheet film (Diamic Co., Ltd., Diafit MQ-005) so as to have a solid content of 10 μm, and 3 at 70 ° C. The film was dried for 4 minutes, and then heated at 50 ° C. for 48 hours to produce a heat-sensitive recording layer. Thereafter, the protective layer coating solution was applied so as to have a solid content of 3.0 μm, and then dried at 80 ° C. for 3 minutes to prepare a heat-sensitive recording material of Example 9. The obtained sheet was cut into 80 mm × 50 mm, and then the release paper was peeled off and bonded to a 500 μm JIS card size PVC card to obtain a card of Example 9.

Comparative Example 3
Example 9 except that the heat-sensitive layer coating solution was applied to a 250 μm PET film instead of the micro-sucker sheet film, and a weak adhesive double-sided tape (Nichiban Rimuka Co., Ltd., manufactured by Nichiban Co., Ltd.) was attached on the back surface so that there was no gap. In the same manner as above, a heat-sensitive recording material of Comparative Example 3 was obtained. The obtained sheet was cut into 80 mm × 50 mm, and then the release paper was peeled off and bonded to a 500 μm JIS card size PVC card to obtain a card of Comparative Example 3.

[Print erasure test 2]
The pattern of “■” was printed on the card of Example 9 and Comparative Example 3 with the standard printing energy of the card reader / writer (manufactured by Panasonic Communications Co., Ltd.), and the thermal recording material was peeled off from the card and re-stretched. The printing was repeated 30 times while changing. Both could be printed without any problems. In addition, Example 9 could be easily reapplied and there was no decrease in adhesive strength. Moreover, there was no deposit on the PVC card. However, in Comparative Example 3, the adhesive force gradually decreased, and the amount of adhesive to the PVC card increased each time the number of printings was repeated.

  The reversible thermosensitive recording medium of the present invention is a price card, product label, poster, bulletin board, guidance display, etc., in combination with magnetic recording and IC, point card, transportation ticket, prepaid card, process management label, logistics label, It can be used as a process instruction label.

Claims (3)

  A heat-sensitive recording material, wherein at least one heat-sensitive recording layer is provided on one surface of a support, and a micro suction layer is provided on the other surface.   A heat-sensitive recording material comprising a transparent support provided with at least one heat-sensitive recording layer, and a micro-suction layer provided on the heat-sensitive recording layer.   The thermosensitive recording material according to claim 1 or 2, wherein the thermosensitive recording layer is a reversible thermosensitive recording layer.