JP2008230170A - Reversible thermosensitive recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reversible thermosensitive recording material with high color developing property excellent in skin whiteness and performance of erasing images, without erasure blushings, in particular a reversible thermosensitive recording material with high color developing concentration when printing under high temperature and high humidity, without erasure fogs. <P>SOLUTION: In the reversible thermosensitive recording material constituted by arranging a thermosensitive recording layer including a usually colorless or light-colored dye precursor and a reversible color developing agent generating reversible color tone change in the dye precursor due to the difference of the cooling speed after heating on at least one face of a support, the thermosensitive recording layer contains at least a polyol compound and a binder component formed by the cross-linking of an araliphatic polyisocyanate compound and an aromatic polyisocyanate compound, and a compounding ration (the mass ratio of nonvolatile components) of the aralipahtic polyisocyanate compound and the aromatic polyisocyanate compound is 70/30 to 95/5. It is preferable that the OH value of the polyol compound is equal to or more than 500 mg KOH/g and equal to or less than 600 mg KOH/g. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a reversible thermosensitive recording material capable of repeatedly forming and erasing an image many times by controlling thermal energy.

  In recent years, a reversible thermosensitive recording material that can form a temporary image and can erase the image when it is no longer needed has attracted attention. As a reversible thermosensitive recording material, a thermosensitive recording material using a colorless or light-colored dye precursor and a reversible color developer that develops color by heating the dye precursor and then re-heats it to erase the color. (See, for example, Patent Documents 1 to 3), a thermal recording material in which organic low-molecular substances such as higher alcohols and higher fatty acids are dispersed in a resin such as polyester, a thermal recording material in which two or more polymers having different refractive indexes are mixed, and the like. It has been known. In particular, a reversible thermosensitive recording material composed of a dye precursor and a reversible developer can form and erase recorded images with high contrast and high sensitivity many times. Have been widely used for the purpose of visualizing information in the card.

  In a reversible thermosensitive recording material composed of a dye precursor and a reversible developer, an organic phosphonic acid compound, an α-hydroxy aliphatic carboxylic acid, a fatty acid dicarboxylic acid and an aliphatic group having 12 or more carbon atoms as a reversible developer. Specific phenolic compounds such as alkylthiophenols having groups, alkyloxyphenols, alkylcarbamoylphenols, alkyl esters of gallic acid are exemplified. However, this recording medium cannot solve the two problems of low color density or incomplete erasing at the same time, and the stability over time of the image is not satisfactory in practice. .

  Further, as an erasing accelerator for improving the erasability of the reversible thermosensitive recording medium, fatty acid, wax, higher alcohol, phosphoric acid, benzoic acid, esters of various acids such as phthalic acid, silicone oil, liquid crystalline compound, interface Activators and fatty acid saturated hydrocarbons having 10 or more carbon atoms have been proposed. However, since the effect is small, the image density at the time of erasure is high and cannot be said to be practical.

  On the other hand, a phenol compound having a long-chain alkyl group has been found to be effective as a reversible developer, and has been proposed as a highly practical reversible thermosensitive recording material (see, for example, Patent Documents 4 and 5). . According to such a recording material, a high-contrast and high-sensitivity recorded image can be formed and erased many times, and widely used for the purpose of visualizing information in the card in a medium such as an IC card or a magnetic card. It has come to be. Even in such a reversible thermosensitive recording material, there is room for improvement in color density. In particular, when printing is performed in a high-temperature and high-humidity environment such as in summer, the color density decreases significantly, which is a practical problem. Even with the use of a dye precursor having high color developability, there is a limit to the improvement of the color density under high temperature and high humidity. In addition, the use of a highly color-forming dye precursor causes problems such as a decrease in background whiteness of unused recording materials, an occurrence of erasure fog, and a decrease in appearance. In a printer for reversible thermosensitive recording material, when erasing an image, a heating medium such as an erasing roll or an erasing bar is brought into full contact with the surface of the reversible thermosensitive recording material without distinguishing between a printed portion and an unprinted portion. Generally done. Erase fog refers to a phenomenon in which color develops when an unprinted portion comes into contact with such a heating medium. The heating medium may not contact the end face of the reversible recording material due to the design of the printer. When the erasure fog occurs, the periphery around the erasure fog appears to be edged with a white end face portion where no erasure fog occurs, and the appearance deteriorates. In particular, when printing / erasing is performed in a high-temperature and high-humidity environment, the erasure fog becomes prominent.

A reversible thermosensitive recording material containing a polyol resin, an aliphatic isocyanate compound, and an aromatic isocyanate compound as a binder component of the thermosensitive recording layer and cross-linked to lower the background density and increase the color density (for example, patent documents) 6) A reversible thermosensitive recording material containing a polyol compound and a xylylene diisocyanate compound and cross-linking, and having an acid value of the polyol compound equal to or less than a certain value (for example, Patent Document 7) has been proposed. The former discloses that the above properties can be balanced by using an aromatic isocyanate compound such as tolylene diisocyanate and an aliphatic isocyanate compound such as hexamethylene diisocyanate in combination. The latter discloses that the xylylene diisocyanate compound can be used to improve the color density and the background whiteness. With these binder components, the decrease in color density and the erasing fog when printing under high temperature and high humidity cannot be suppressed.
Japanese Patent Laid-Open No. 6-210954 JP-A-6-210955 JP-A-7-125428 Japanese Patent Laid-Open No. 7-179043 JP 2000-33776 A JP 2004-276338 A JP 2005-178004 A

  The problem of the present invention is that the background whiteness, the erasability of the image are good, there is no erasure fog, and the reversible thermosensitive recording material has high color development, especially the color density when printed under high temperature and high humidity, the erasure fog. It is an object of the present invention to provide a reversible thermosensitive recording material free from any problem.

  As a result of examining the binder component constituting the thermosensitive recording layer of the reversible thermosensitive recording material in order to solve these problems, the present inventor has found that the above-described problems can be solved by the following invention.

  A heat-sensitive material comprising, on at least one side of a support, usually a colorless or light-colored dye precursor and a reversible developer that causes a reversible color change in the dye precursor due to a difference in cooling rate after heating. In a reversible thermosensitive recording material provided with a recording layer, the thermosensitive recording layer contains at least a polyol compound, an araliphatic polyisocyanate compound and an aromatic polyisocyanate compound, and a binder component formed by crosslinking. The invention relates to a reversible thermosensitive recording material characterized in that the blend ratio of polyisocyanate compound / aromatic polyisocyanate compound (mass ratio of non-volatile content) is 70/30 to 95/5.

  The aromatic polyisocyanate compound is preferably a compound represented by the following general formula 1.

In General Formula 1, R ¹ represents a methyl group or an ethyl group. The position of the methyl group bonded to each benzene ring is one of the 2, 4, 5, and 6 positions, and the location is not limited.

  The aromatic aliphatic polyisocyanate compound is preferably a compound represented by the following general formula 2.

In the general formula 2, R ² represents a methyl group or an ethyl group.

  The OH value of the polyol compound is preferably 500 mgKOH / g or more and 600 mgKOH / g or less.

  When the dye precursor is a compound having a maximum absorbance at 400 to 700 nm of 1.5 or more of an absorption spectrum of a solution having an active ingredient ratio (mass ratio) of dye precursor / acetic acid / acetone of 2/6/92 preferable.

  According to the present invention, the background whiteness, the erasability of the image are good, there is no erasure fog, and the color reversible heat-sensitive recording material has high color development, especially when the color is printed under high temperature and high humidity, and there is no erasure fog. A reversible thermosensitive recording material can be obtained.

  The reversible thermosensitive recording material of the present invention will be described in detail below. The reversible thermosensitive recording material of the present invention has a reversible color change which causes a reversible color change in the dye precursor due to the difference in cooling rate after heating, usually from a colorless or light dye precursor, on at least one side of the support. In a reversible thermosensitive recording material provided with a thermosensitive recording layer comprising a developer, the thermosensitive recording layer is formed by crosslinking at least a polyol compound, an araliphatic polyisocyanate compound and an aromatic polyisocyanate compound. It contains a binder component, and the blending ratio of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound (mass ratio of nonvolatile content) is 70/30 to 95/5. According to the present invention, the background whiteness, the erasability of the image are good, there is no erasure fog, and the color reversible thermosensitive recording material has high color development, especially when the color is printed under high temperature and high humidity, and there is no erasure fog. A reversible thermosensitive recording material can be obtained.

  When the binder component of the heat-sensitive recording layer is formed by cross-linking of a polyol compound and an araliphatic polyisocyanate compound alone, the background density is low, and the color developability when printed in an environment of about 23 ° C. and 50% RH is good It is. On the other hand, when printing is performed under high temperature and high humidity such as 35 ° C. and 80% RH, the color density is remarkably lowered, and there is a problem of improving the color density under high temperature and high humidity. As a result of intensive investigations focusing on the binder component of the heat-sensitive recording layer, the inventors have found that, when an aromatic polyisocyanate compound is used, the background density increases and erasure fog occurs, but color development under high temperature and high humidity It was found that the concentration did not decrease easily. Furthermore, as a result of studying the polyisocyanate compound constituting the binder component of the heat-sensitive recording layer, the blending ratio (mass ratio of non-volatile content) of araliphatic polyisocyanate compound / aromatic polyisocyanate compound was 70/30 to 95/5. Thus, it has been found that it is possible to balance the background whiteness, suppression of erasure fog, and color density under high temperature and high humidity. When the blending ratio is less than 70/30, the background whiteness is lowered and erasure fog is generated. When it is more than 95/5, the color density at the time of printing at high temperature and high humidity is lowered.

  The aromatic polyisocyanate compound according to the present invention refers to a compound in which two or more isocyanate groups are directly bonded to carbon atoms constituting an aromatic ring such as a benzene ring or a naphthalene ring. Examples of the aromatic polyisocyanate compound include 2,4- or 2,6-toluene diisocyanate (TDI) or a mixture thereof, phenylene diisocyanate (PDI) such as 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and 4,4. Diphenylmethane diisocyanate (MDI) such as' -diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylene diisocyanate, 1,5-naphthalene diisocyanate (NDI), tolidine diisocyanate (TODI), 4,4'-diphenyl diisocyanate, 4,4'-diphenyl ether diisocyanate, various dianisidine diisocyanates Aromatic diisocyanate compounds, 1,3,5-triisocyanate benzene, 2,4,6-triisocyanate toluene, 2,4,6-triisocyanate diphenyl ether, 4,4 ', 4 "-triphenylmethane triisocyanate, Aromatic triisocyanate compounds such as various tri (isocyanatephenyl) thiophosphites, tetrafunctional or higher functional aromatic isocyanate compounds such as 4,4′-dimethyldiphenylmethane-2,2 ′, 5,5′-tetraisocyanate, and the like; and Among the above compounds, biuret type polyisocyanate compound derived from 3 mol of diisocyanate compound and 1 mol of water, isocyanurate type polyisocyanate compound formed by trimerization of diisocyanate compound, glycols, triols or Trifunctionals such as adduct-type polyisocyanate compounds obtained by adding the above-mentioned polyisocyanate compounds to ester polyols, polyether polyols, and the like, and polymethylene polyphenyl polyisocyanate compounds by-produced in the production of 4,4'-diphenylmethane diisocyanate In addition to the above polyisocyanate compounds, various oligomers and polymers containing isocyanates, etc. These aromatic polyisocyanate compounds are used alone or in combination of two or more. Adduct type aromatic polyisocyanate compounds are preferred from the standpoints of degree, suppression of erasure fog, and color developability under high temperature and high humidity, and particularly preferred are adduct type toluene diisocyanate compounds represented by the following general formula 1.

In General Formula 1, R ¹ represents a methyl group or an ethyl group. The position of the methyl group bonded to each benzene ring is one of the 2, 4, 5, and 6 positions, and the location is not limited.

  The araliphatic polyisocyanate compound according to the present invention refers to a compound in which an aromatic ring and an isocyanate group are bonded via a divalent hydrocarbon group such as a methylene group or an ethylene group, and such a bond has two or more positions. . Examples of the araliphatic polyisocyanate compound include 1,3- or 1,4-xylylene diisocyanate (XDI) or a mixture thereof, 1,3- or 1,4-bis (1-isocyanate-1-methylethyl) benzene ( TMXDI) or a mixture thereof, an araliphatic diisocyanate compound such as ω, ω′-diisocyanate-1,4-diethylbenzene, an araliphatic triisocyanate compound such as 1,3,5-triisocyanatomethylbenzene, and an aromatic poly Examples of the biuret type, isocyanurate type, and adduct type triisocyanate polyisocyanate compounds described above for the isocyanate compound, and various oligomers and polymers containing isocyanate. These araliphatic polyisocyanate compounds are used alone or in admixture of two or more. Among these, adduct-type araliphatic polyisocyanate compounds are preferable in terms of background whiteness, suppression of erasure fog, and color developability, and particularly preferably an adduct-type 1,3-type represented by the following general formula 2. It is a xylylene diisocyanate compound.

In the general formula 2, R ² represents a methyl group or an ethyl group.

  In the heat-sensitive recording layer according to the present invention, a polyisocyanate compound other than an araliphatic polyisocyanate compound and an aromatic polyisocyanate compound can be blended within a range that does not interfere with the object of the present invention. The total blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound and the aromatic polyisocyanate compound with respect to all the polyisocyanate compounds constituting the heat-sensitive recording layer needs to be 80% by mass or more, preferably 90%. It is at least 95% by mass, more preferably at least 95% by mass.

  Examples of polyisocyanate compounds other than aromatic aliphatic polyisocyanate compounds and aromatic polyisocyanate compounds include trimethylene diisocyanate, pentamethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, and 1,2-propylene. Diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate (TMDI), 2,6-diisocyanate methyl Aliphatic diisocyanate compounds such as caproate and lysine diisocyanate, 1,4,8-triisocyanate octane, 1,6,11-triiso Anatoundecane, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-triisocyanate hexane, 2,5,7-trimethyl-1,8-diisocyanate-5-isocyanate methyloctane, various lysine ester tris Aliphatic polyisocyanate compounds such as aliphatic triisocyanate compounds such as isocyanate; hydrogenated TDI, hydrogenated XDI, hydrogenated MDI, hydrogenated XDI, dimer acid diisocyanate (DDI), isophorone diisocyanate (IPDI), 1,3-cyclo Pentane diisocyanate, 1,3- or 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 3,3'-dimethyldicyclohexyl meta -4,4'-diisocyanate, alicyclic diisocyanate compounds such as 1,5-tetrahydronaphthalene diisocyanate, 1,3,5-triisocyanatecyclohexane, 2- (3-isocyanatopropyl) -2,5-di (isocyanate methyl) ) -Bicyclo [2.2.1] heptane, 2- (3-isocyanatopropyl) -2,6-di (isocyanatomethyl) -bicyclo [2.2.1] heptane, 3- (3-isocyanatopropyl)- 2,5-di (isocyanatomethyl) -bicyclo [2.2.1] heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) -bicyclo [2.2.1 ] Heptane, 6- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3- Isocyanatopropyl) -bicyclo [2.2.1] heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyanatopropyl) -bicyclo [2.2.1] heptane, 6- ( Alicyclic polyisocyanate compounds such as alicyclic triisocyanate compounds such as 2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyanatepropyl) -bicyclo [2.2.1] heptane; and aromatic poly Examples of the biuret type, isocyanurate type, and adduct type triisocyanate polyisocyanate compounds described above for the isocyanate compound, and various oligomers and polymers containing isocyanate.

  The heat-sensitive recording layer according to the present invention contains a polyol compound, and the polyol compound crosslinks with the above-described araliphatic polyisocyanate compound / aromatic polyisocyanate compound to function as a binder. When the polyol compound has an OH value of 80 mgKOH / g or more, the binder formed by crosslinking of the polyol compound and the polyisocyanate compound has a high crosslinking density, and the durability of the heat-sensitive recording layer when repeatedly printing and erasing is achieved. Since it improves, it is preferable. More preferably, it is 200 mgKOH / g or more and 600 mgKOH / g or less, More preferably, it is 300 mgKOH / g or more and 600 mgKOH / g or less, Most preferably, it is 500 mgKOH / g or more and 600 mgKOH / g or less. When the OH value is 500 mgKOH / g or more and 600 mgKOH / g or less, color development is improved in an environment of about 23 ° C. and 50% RH and in a high temperature and high humidity environment of 35 ° C. and 80% RH, which is a preferred embodiment. . On the other hand, if the OH value exceeds 600 mgKOH / g, the repeated durability may decrease. Here, the OH value represents a free hydroxyl group contained in 1 g of resin in terms of mg of potassium hydroxide equivalent to this.

  The reversible thermosensitive recording material utilizing the reaction between the dye precursor and the reversible developer as in the present invention, the dye precursor reacts and develops color with free fatty acids in the polyol compound, and the background whiteness is increased. Since there exists a possibility of making it fall, it is desirable for the acid value of a polyol compound to be low. The acid value of the polyol compound is preferably 5 or less, more preferably 3 or less, still more preferably 1 or less, and particularly preferably 0.5 or less. Here, the acid value represents a free fatty acid contained in 1 g of the resin in terms of mg of potassium hydroxide equivalent to this.

  Examples of the polyol compound according to the present invention include low molecular weight polyhydric alcohol, polyether polyol, poly (meth) acrylic polyol, polyester polyol, polycarbonate polyol, polyester polycarbonate polyol, alkyd polyol, caprolactone polyol, and silicone polyol. These polyol compounds can be used alone or in admixture of two or more.

  Examples of the low molecular weight polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, dipropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 1,8-octanediol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, di- Glycerol, pentaerythritol, dipentaerythritol, diacetone glycol, hexanetriol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-dihydroxybenzene, bisphenol A, bisphenol Aliphatic, such as F, alicyclic, aromatic polyhydric alcohols or polyhydric phenols or their condensation products thereof.

  The polyether polyol is a polymer having a main chain composed of an ether bond, and includes polyethylene glycol, polypropylene glycol, polybutylene glycol, and these branched esters. Examples of polyether polyols include ethylene oxide and / or propylene oxide adducts of polyhydric alcohols, polytetramethylene glycol, and the like.

  Poly (meth) acrylic polyols and polyester polyols are those obtained by transesterification of the polyhydric alcohol and the carboxylic acid in an amount less than the stoichiometry of the polyhydric alcohol or its ester, anhydride, halide, etc. Can be mentioned. That is, poly (meth) acrylic polyol is a copolymer of acrylic acid, methacrylic acid and esters thereof, which includes a hydroxyl group, and a copolymer component containing a hydroxyl group includes 2-hydroxy acrylate. Ethyl, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxy-1-methylethyl acrylate, 2-hydroxy-1-methylethyl methacrylate, acrylic acid 3-chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, allyl alcohol and the like are used. Examples of copolymer components other than acrylic acid, methacrylic acid, and esters thereof include styrene, α-methylstyrene, vinyltoluene, acrylamide, methacrylamide and derivatives thereof, vinyl acetate, and maleic anhydride.

  Polyester polyol means what has a hydroxyl group among the condensates of a polybasic acid and a polyhydric alcohol. Polybasic acids used in these include aromatic polybasic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, naphthalenedicarboxylic acid, oxalic acid, malonic acid, succinic acid, glutar Acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, 2-methylsuccinic acid, 2-methyladipic acid, 3-methyladipic acid, 3-methylpentanedioic acid, 2-methyloctane There are aliphatic polybasic acids such as diacid, 3,7-dimethyldecanedioic acid, 3,8-dimethyldecanedioic acid, and dimer acid, and acid anhydrides obtained from these polybasic acids are also used. As the polyhydric alcohol, the low molecular weight polyhydric alcohols exemplified above can be used.

  Instead of the polybasic acid or polyhydric alcohol constituting the polyester polyol, an acid component such as hydroxycarboxylic acid and an alcohol component in one molecule, or an acid component in the same molecule such as a cyclic lactone compound thereof A compound obtained by dehydrating and condensing the alcohol component can also be used. Examples of cyclic lactone compounds include β-propiolactone, dimethylpropiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, δ-caprolactone, ε-caprolactone, γ-caprolactone, γ -Laurolactone, γ-palmilactone, γ-stearolactone, crotolactone, α-angelica lactone, β-angelica lactone, macrocyclic lactones having 7 or more carbon atoms constituting the ring, lactone rings such as coumarin are benzene Examples thereof include compounds condensed with a ring and the like. Further, alkyd polyols obtained by condensing three kinds of higher fatty acids in addition to polybasic acids and polyhydric alcohols are also included.

  Examples of the silicone polyol include silicone oils having a siloxane bond in the molecule and a terminal hydroxyl group. In addition, fluorine-containing polyols such as hydroxyl-containing fluoroolefin, polyol hydroxyl-terminated polybutadiene, polyisoprene, hydrogenated polybutadiene, hydrogenated polyisoprene, polyurethane and the like can be used.

  As the polyol compound according to the present invention, the polyester polyol, which is a condensate of a cyclic lactone compound and a polyhydric alcohol, has a low acid value, good background whiteness, and durability of the thermal recording layer when repeatedly printed and erased. Since it is excellent also in a property, it is preferable. In particular, polycaprolactone diol and polycaprolactone triol, which are condensates of ε-caprolactone and polyhydric alcohol, are preferably used.

  The blending ratio of the polyol compound and the total polyisocyanate compound according to the present invention is preferably 1:20 to 5: 1, more preferably 1:10 to 2 in terms of the equivalent ratio of the hydroxyl group of the polyol compound to the isocyanate group of the total polyisocyanate compound. : 1. When the equivalent ratio is less than 1:20, the coating strength of the heat-sensitive recording layer tends to be weak. When the ratio is more than 5: 1, the binder is not sufficiently cross-linked, and repeated durability is likely to deteriorate due to insufficient heat resistance. Moreover, the usage-amount of the binder component formed by bridge | crosslinking of the polyol compound which concerns on this invention, and all the polyisocyanate compounds needs to be 80 mass% or more by the dry solid content ratio with respect to all the binders, More preferably, it is 90 masses. % Or more, particularly preferably 95% by mass or more.

  In the heat-sensitive recording layer according to the present invention, a binder component can be added in addition to the binder formed by crosslinking of the polyol compound and the polyisocyanate compound as long as the object of the present invention is not hindered. Specific examples of the binder include starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, polyacrylic acid soda, acrylic acid amide / acrylic acid ester copolymer, acrylic acid amide / acrylic acid ester / methacrylic acid ternary Copolymer, water-soluble polymer such as alkali salt of styrene / maleic anhydride copolymer, alkali salt of ethylene / maleic anhydride copolymer, polyvinyl acetate, polyacrylate ester, styrene / butadiene copolymer, Latex such as acrylonitrile / butadiene copolymer, methyl acrylate / butadiene copolymer, ethylene / vinyl acetate copolymer, ethylene / vinyl chloride copolymer, polyvinyl chloride, ethylene / vinylidene chloride copolymer, polyvinylidene chloride Kind, Thermosetting resins, electron beam curable resins, which are cured by reaction with a crosslinking agent such as amines, phenols, epoxies, etc. Examples include ultraviolet curable resins.

  As oligomers and monomers used for electron beams and ultraviolet curable resins, there are many types of acrylic oligomers and monomers with excellent radiation curing properties, polyene-thiol oligomers and monomers, and photo cationic polymerization type epoxy oligomers and monomers. Etc. Examples of the acrylic monomer include a monofunctional monomer, a bifunctional monomer, and a polyfunctional monomer. In particular, a photopolymerization initiator and a photopolymerization accelerator are used at the time of ultraviolet crosslinking.

  Examples of the acrylic oligomer / monomer include polyester acrylate, polyether acrylate, epoxy acrylate, polyurethane acrylate, silicone acrylate, melamine acrylate, polybutadiene acrylate, and the like.

  Further, the amount of all binders used in the heat-sensitive recording layer is preferably in the range of 35% by mass or more and 65% by mass or less in terms of the dry solid content ratio relative to the whole heat-sensitive recording layer. If it is larger than this range, the color density may be significantly reduced. Conversely, if it is smaller than this range, the heat resistance and mechanical strength of the heat-sensitive recording layer may be reduced, and the layer may be deformed or the color density may be reduced. . More preferably, it is 40 to 60 mass%, Most preferably, it is 45 to 55 mass%.

  The mixture of the polyol compound and the polyisocyanate compound may be used as it is when they are in liquid form, but can also be used after being diluted with various polyisocyanate compounds and non-reactive solvents. As the solvent that can be used, a solvent that dissolves the polyol compound and the polyisocyanate compound and disperses and dissolves the dye precursor and the reversible developer is preferable. Specifically, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone, and tetrahydrofuran, esters such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isopropyl acetate, ethyl lactate, and glycol acetate monoethyl ether , Ethers such as diethyl ether, glycol dimethyl ether, glycol diethyl ether, dioxane, aromatic compounds such as benzene, toluene, xylene, cresol, chlorobenzene, styrene, methylene chloride, ethylene chloride, carbon tetrachloride, chloroform, ethylene chlorohydrin , Chlorinated hydrocarbons such as dichlorobenzene, N, N-dimethylformaldehyde, pentane, hexane, etc. can be used, and polyisocyanate compounds It is preferable to use an organic solvent having no active hydrogen with a refractory. Moreover, what is necessary is just to perform the crosslinking reaction of the said polyol compound and various polyisocyanate compounds at reaction temperature 50-160 degreeC, and reaction time 0.1-100 hours. Needless to say, it takes a long time when the reaction temperature is low, and a short time at a high temperature.

  Specific examples of the dye precursor according to the present invention include the following, for example, but the present invention is not limited thereto.

  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-diethylamino-6-methyl-7- (2 ', 4'-xylylamino) fluorane,

  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'-tetrahydropyrrolyl-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-N- n-butylamino-6-methyl-7-phenylaminofluorane, 3-N-methyl-Nn-propylamino-6-methyl-7-phenylamino Fluorane, 3-N-ethyl-N-isopentylamino-6-methyl-7-phenylaminofluorane, 3-N-ethyl-N-cyclohexylamino-6-methyl-7-phenylaminofluorane, 3- N-ethyl-N-isopentylamino-6-methyl-7-o-chlorophenylaminofluorane, 3-N-ethyl-Np-tolylamino-6-methyl-7-phenylaminofluorane, 3-N- Ethyl-N- (3'-ethoxypropyl) amino-6-methyl-7-phenylaminofluorane, 3-N-ethyl-N- (4'-ethoxybutyl) amino-6-methyl-7-phenylaminofluor Oran, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-octylaminofluorane, 3-diethylamino-7 Phenylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-chloro-7-methylfluorane, 3-diethylamino-7- (3,4-dichloroanilino) 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,

  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.

  The dye precursors may be used alone or in combination of two or more. Toning can also be performed by mixing dye precursors that develop colors in other hues.

  The dye precursor according to the present invention has a maximum absorbance at 400 to 700 nm of 1.5 or more of an absorption spectrum of a solution having an active ingredient ratio (mass ratio) of dye precursor / acetic acid / acetone of 2/6/92. A compound is preferred because it is excellent in color developability under high temperature and high humidity. More preferably, it is 2.0 or more. Usually, when such a high color-forming dye precursor is used, the background density becomes high and erasure fog is generated, but by specifying the ratio of various polyisocyanate compounds used in the heat-sensitive recording layer as in the present invention. Further, it is possible to obtain high color developability without causing deterioration in background whiteness and erasability and without causing erasure fog. On the other hand, if the maximum absorbance is too high, the color density is improved, but the background density is increased, and the erasability is deteriorated and erasure fog is likely to occur. Therefore, the maximum absorbance is preferably 2.5 or less. Examples of the dye precursor satisfying the above conditions include 3-diethylamino-6-methyl-7- (2 ′, 4′-xylylamino) fluorane (maximum absorbance 2.7 / 584 nm), 3-diethylamino-6-methyl- 7-m-tolylaminofluorane (maximum absorbance 2.2 / 450 nm, 590 nm), 3-N′-tetrahydropyrrolyl-6-methyl-7-phenylaminofluorane (maximum absorbance 2.1 / 582 nm), 3 -Diethylamino-6-methyl-7-p-tolylaminofluorane (maximum absorbance 2.0 / 450 nm), 3-diethylamino-6-methyl-7-phenylaminofluorane (maximum absorbance 2.0 / 449 nm, 585 nm) 3-N-ethyl-N- (3′-ethoxypropyl) amino-6-methyl-7-phenylaminofluorane ( Large absorbance 1.7,586 nm), 3-N-methyl-N-cyclohexylamino-6-methyl-7-phenylaminofluorane (maximum absorbance 1.6,568 nm), 3-di-n-pentylamino- 6-methyl-7-phenylaminofluorane (maximum absorbance 1.5, 587 nm) and the like.

  The reversible developer according to the present invention is a developer that takes into consideration not only the image formation by heating but also the erasure of the recorded image, and the thermosensitive recording layer using the reversible developer rewrites the display contents repeatedly. It is possible. Of course, it can also be used for applications in which image formation is performed only once, as is the case with ordinary heat-sensitive recording materials. As the reversible developer, compounds represented by the following general formulas 3, 5, and 6 are preferable. Particularly, the compound represented by the general formula 3 is preferable because it is excellent in image coloring and erasing properties. Of the general formula 3, the compound represented by the general formula 4 is preferable as a compound that satisfies a wide range of temperature conditions that can be erased and meets the demand for high-speed erasing and printing. On the other hand, the compound represented by the general formula 4 has a problem that the color density is lowered and the erasing fog is remarkably generated under high temperature and high humidity. In the present invention, when the compound represented by the general formula 4 is used as the reversible developer, color development under high temperature and high humidity is greatly improved, and this is a particularly preferred embodiment. The reversible developer according to the present invention is not limited to this. Each of the reversible developers may be used alone or in combination of two or more.

In General Formula 3, X ¹ and X ² may be the same or different, and at least one of —O—, —S—, —CO—, —NH—, —SO— or —SO ₂ — may be used. Represents a divalent group containing no hydrocarbon group at the end. At least one of X ¹ and X ² is preferably a divalent group having a —CONH— bond that does not contain a hydrocarbon group at the terminal as the minimum structural unit. R ³ represents a single bond or a divalent hydrocarbon group having 1 to 36 carbon atoms. R ⁴ represents a divalent hydrocarbon group having 1 to 36 carbon atoms. R ³ and R ⁴ preferably have 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to ⁴ carbon atoms. R ⁵ represents a monovalent hydrocarbon group having 1 to 50 carbon atoms, preferably a hydrocarbon group having 4 to 36 carbon atoms, more preferably 6 to 24 carbon atoms, and particularly preferably 8 to 24 carbon atoms. R ³ and R ⁴ mainly represent an alkylene group, and R ⁵ mainly represents an alkyl group or an alkenyl group. In the case of R ³ and R ⁴ , an aromatic ring may be included. f represents an integer of 0 to ^4, and when f is 2 or more, R ⁴ and X ^{2 that} are repeated may be the same or different.

Specific examples of the divalent group having a —CONH— bond that does not include a hydrocarbon group at the terminal as the minimum structural unit in X ¹ and X ² in the general formula 3 include —CONH—, —NHCO—, and —NHCOO. -, - OCONH -, - CONHCO -, - NHCONH -, - CONHNHCO -, - NHCOCONH -, - CONHCONH -, - NHCONHCO -, - NHCONHNH -, - NHNHCONH -, - NHSO 2 NHCO -, - CONHSO 2 NH-, -CONHNHCONH-, -NHCONHNHCO-, -CONHNHCOO-, -OCONHNHCO- and the like. X ¹ and X ² are preferably —CONH—, —NHCO—, —NHCONH—, —CONHNHCO—, and —NHCOCONH—.

  Examples of the compound represented by the general formula 3 include compounds represented by the following chemical formula. In the following chemical formula, r represents an integer of 0 to 36, and t represents an integer of 1 to 36. r and t are preferably integers of 1 to 18, more preferably 1 to 12, and particularly preferably 1 to 4. s represents an integer of 0 to 49. Preferably it is 3-35, More preferably, it is 5-23, Most preferably, it is an integer of 7-23. u represents an integer of 0 to 30. Preferably it is 0-12, More preferably, it is an integer of 0-6. In the following exemplified compounds, the terminal hydrocarbon group is an alkyl group, but an alkenyl group having an unsaturated bond can also be used.

  In the general formula 3, a compound represented by the following general formula 4 in which f is 0 is particularly preferable.

X ³ in the general formula 4 represents —O—, —S—, or a divalent group having a —CONH— bond that does not include a hydrocarbon group at the terminal as a minimum structural unit. In X ³ , specific examples of the divalent group having a —CONH— bond that does not contain a hydrocarbon group at the terminal as the minimum constitutional unit include the divalent groups exemplified for X ¹ and X ^2. . R ⁶ represents a single bond or a divalent hydrocarbon group having 1 to 36 carbon atoms, preferably 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably a divalent carbon atom having 1 to 4 carbon atoms. It is a hydrogen group. R ⁶ specifically represents an alkylene group, but may contain an aromatic ring. R ⁶ is preferably a simple divalent hydrocarbon group not containing vinylene and 1,4-phenylene. R ⁷ represents a monovalent hydrocarbon group having 1 to 50 carbon atoms, preferably a hydrocarbon group having 4 to 36 carbon atoms, more preferably 6 to 24 carbon atoms, and particularly preferably 8 to 24 carbon atoms. . R ⁷ represents mainly an alkyl group or an alkenyl group.

  Specific examples of the compound represented by General Formula 4 include the compounds represented by the above (1-1) to (1-20). Among these, the compounds represented by (1-1) to (1-12) are preferable, and (1-3) to (1-11) are more preferable.

  Specific compounds represented by formula 4 are listed below. N- [3- (p-hydroxyphenyl) propionyl] -Nn-octadecanoylamine, N- [3- (p-hydroxyphenyl) propionyl] -Nn-icosanoylamine, N- [3 -(P-hydroxyphenyl) propionyl] -Nn-docosanoylamine, N- [3- (p-hydroxyphenyl) propionyl] -Nn-tetracosanoylamine, N- [3- (p-hydroxy) Phenyl) propionyl] -Nn-hexacosanoylamine, N- [3- (p-hydroxyphenyl) propionyl] -Nn-octacosanoylamine, N- [3- (p-hydroxyphenyl) propionyl] -Nn-triacontanoylamine, N- [3- (p-hydroxyphenyl) propionyl] -Nn-dotriacontanoylamine N- [3- (p-hydroxyphenyl) propionyl] -Nn-tetratriacontanoylamine, N- [3- (p-hydroxyphenyl) propionyl] -Nn-hexatriacontanoylamine, N -[3- (p-hydroxyphenyl) propionyl] -Nn-tetracontanoylamine, N- [3- (p-hydroxyphenyl) propionyl] -Nn-tetratetracontanoylamine, N- [3 -(P-hydroxyphenyl) propionyl] -Nn-pentacontanoylamine; N- [6- (p-hydroxyphenyl) hexanoyl] -Nn-octadecanoylamine, N- [6- (p-hydroxy) Phenyl) hexanoyl] -Nn-icosanoylamine, N- [6- (p-hydroxyphenyl) hexanoyl] Nn-docosanoylamine, N- [6- (p-hydroxyphenyl) hexanoyl] -Nn-tetracosanoylamine, N- [6- (p-hydroxyphenyl) hexanoyl] -Nn-hexa Cosanoylamine, N- [6- (p-hydroxyphenyl) hexanoyl] -Nn-octacosanoylamine, N- [6- (p-hydroxyphenyl) hexanoyl] -Nn-triacontanoylamine, N- [6- (p-hydroxyphenyl) hexanoyl] -Nn-dotriacontanoylamine, N- [6- (p-hydroxyphenyl) hexanoyl] -Nn-tetratriacontanoylamine, N- [6- (p-hydroxyphenyl) hexanoyl] -Nn-hexatricontanoylamine, N- [6- (p-hydroxyphenyl) Phenyl) hexanoyl] -Nn-tetracontanoylamine, N- [6- (p-hydroxyphenyl) hexanoyl] -Nn-tetratetracontanoylamine, N- [6- (p-hydroxyphenyl) hexanoyl ] -Nn-pentacontanoylamine;

  N- [2- (p-hydroxyphenyl) aceto] -N'-n-dodecanohydrazide, N- [2- (p-hydroxyphenyl) aceto] -N'-n-octadecanohydrazide, N- [ 2- (p-hydroxyphenyl) aceto] -N'-n-icosanohydrazide, N- [2- (p-hydroxyphenyl) aceto] -N'-n-docosanohydrazide, N- [2- (p -Hydroxyphenyl) aceto] -N'-n-tetracosanohydrazide, N- [2- (p-hydroxyphenyl) aceto] -N'-n-hexacosanohydrazide, N- [2- (p-hydroxy) Phenyl) aceto] -N'-n-octacosanohydrazide, N- [2- (p-hydroxyphenyl) acet] -N'-n-triacontanohydrazide, N- [2- (p-hydroxyphenyl) Cet] -N'-n-dotriacontanohydrazide, N- [2- (p-hydroxyphenyl) acet] -N'-n-tetratriacontanohydrazide, N- [2- (p-hydroxyphenyl) Aceto] -N'-n-hexatriacontanohydrazide, N- [2- (p-hydroxyphenyl) aceto] -N'-n-tetracontanohydrazide, N- [2- (p-hydroxyphenyl) acetate ] -N'-n-tetratetracontanohydrazide, N- [2- (p-hydroxyphenyl) aceto] -N'-n-pentacontanohydrazide; N- [3- (p-hydroxyphenyl) propiono]- N'-n-octadecanohydrazide, N- [3- (p-hydroxyphenyl) propiono] -N'-n-icosanohydrazide, N- [3- (p-hydroxy Nyl [propiono] -N'-n-docosanohydrazide, N- [3- (p-hydroxyphenyl) propiono] -N'-n-tetracosanohydrazide, N- [3- (p-hydroxyphenyl) propiono ] -N'-n-hexacosanohydrazide, N- [3- (p-hydroxyphenyl) propiono] -N'-n-octacosanohydrazide, N- [3- (p-hydroxyphenyl) propiono]- N'-n-triacontanohydrazide, N- [3- (p-hydroxyphenyl) propiono] -N'-n-dotriacontanohydrazide, N- [3- (p-hydroxyphenyl) propiono] -N '-N-tetratriacontanohydrazide, N- [3- (p-hydroxyphenyl) propiono] -N'-n-hexatriacontanohydrazide, N- [3- (p-hydroxyphenyl) propiono] -N′-n-tetracontanohydrazide, N- [3- (p-hydroxyphenyl) propiono] -N′-n-tetratetracontanohydrazide, N- [ 3- (p-hydroxyphenyl) propiono] -N′-n-pentacontanohydrazide;

  N- [6- (p-hydroxyphenyl) hexano] -N'-n-tetradecanohydrazide, N- [6- (p-hydroxyphenyl) hexano] -N'-n-octadecanohydrazide, N- [6- (p-hydroxyphenyl) hexano] -N′-n-docosanohydrazide, N- [6- (p-hydroxyphenyl) hexano] -N′-n-hexacosanohydrazide, N- [6- (P-Hydroxyphenyl) hexano] -N′-n-triacontanohydrazide, N- [6- (p-hydroxyphenyl) hexano] -N′-n-hexatriacontanohydrazide, N- [6- ( p-hydroxyphenyl) hexano] -N'-n-tetracontanohydrazide, N- [6- (p-hydroxyphenyl) hexano] -N'-n-pentacontanohydrazide; -[11- (p-hydroxyphenyl) undecano-N'-n-decanohydrazide, N- [11- (p-hydroxyphenyl) undecano-N'-n-tetradecanohydrazide, N- [11- ( p-hydroxyphenyl) undecano-N'-n-octadecanohydrazide, N- [11- (p-hydroxyphenyl) undecano-N'-n-docosanohydrazide, N- [11- (p-hydroxyphenyl) Undecano-N'-n-hexacosanohydrazide, N- [11- (p-hydroxyphenyl) undecano-N'-n-triacontanohydrazide, N- [11- (p-hydroxyphenyl) undecano-N ' -N-hexatriacontanohydrazide, N- [11- (p-hydroxyphenyl) undecano-N'-n-tetracontanohydride Nido [N- [11- (p-hydroxyphenyl) undecano-N'-n-pentacontanohydrazide; N- [p- (p-hydroxyphenyl) benzo] -N'-n-octadecanohydrazide, N- [P- (p-hydroxyphenyl) benzo] -N'-n-docosanohydrazide, N- [p- (p-hydroxyphenyl) benzo] -N'-n-hexacosanohydrazide, N- [p- (P-Hydroxyphenyl) benzo] -N'-n-triacontanohydrazide, N- [p- (p-hydroxyphenyl) benzo] -N'-n-hexatriacontanohydrazide, N- [p- ( p-hydroxyphenyl) benzo] -N'-n-tetracontanohydrazide, N- [p- (p-hydroxyphenyl) benzo] -N'-n-pentacontanohydrazide; N- [P- (p-hydroxyphenylmethyl) benzo] -N'-n-octadecanohydrazide, N- [p- (p-hydroxyphenylmethyl) benzo] -N'-n-docosanohydrazide, N- [ p- (p-hydroxyphenylmethyl) benzo] -N'-n-hexacosanohydrazide, N- [p- (p-hydroxyphenylmethyl) benzo] -N'-n-triacontanohydrazide, N- [ p- (p-hydroxyphenylmethyl) benzo] -N'-n-hexatriacontanohydrazide, N- [p- (p-hydroxyphenylmethyl) benzo] -N'-n-tetracontanohydrazide, N- [P- (p-hydroxyphenylmethyl) benzo] -N′-n-pentacontanohydrazide;

  N- [2- (p-hydroxyphenyl) ethyl] -N'-n-tetradecyloxamide, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-octadecyloxamide, N- [ 2- (p-hydroxyphenyl) ethyl] -N'-n-docosyloxamide, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-hexacosyloxamide, N- [2 -(P-hydroxyphenyl) ethyl] -N'-n-triacontyloxamide, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-hexatriacontyloxamide, N- [ 2- (p-hydroxyphenyl) ethyl] -N′-n-tetracontyloxamide, N- [2- (p-hydroxyphenyl) ethyl] -N′-n-pentacontyloxamide; N- [3 -(P- Droxyphenyl) propyl] -N'-n-octadecyloxamide, N- [3- (p-hydroxyphenyl) propyl] -N'-n-docosyloxamide, N- [3- (p-hydroxyphenyl) ) Propyl] -N'-n-hexacosyl oxamide, N- [3- (p-hydroxyphenyl) propyl] -N'-n-triacontyl oxamide, N- [3- (p-hydroxyphenyl) ) Propyl] -N'-n-hexatriacontyl oxamide, N- [3- (p-hydroxyphenyl) propyl] -N'-n-tetracontyl oxamide, N- [3- (p-hydroxy) Phenyl) propyl] -N'-n-pentacontyloxamide;

  N- [11- (p-hydroxyphenyl) undecanyl] -N'-n-decyloxamide, N- [11- (p-hydroxyphenyl) undecanyl] -N'-n-tetradecyloxamide, N- [11- (P-hydroxyphenyl) undecanyl] -N′-n-octadecyloxamide, N- [11- (p-hydroxyphenyl) undecanyl] -N′-n-docosyloxamide, N- [11- (p- Hydroxyphenyl) undecanyl] -N′-n-hexacosyl oxamide, N- [11- (p-hydroxyphenyl) undecanyl] -N′-n-triacontyl oxamide, N- [11- (p- Hydroxyphenyl) undecanyl] -N'-n-hexatriacontyloxamide, N- [11- (p-hydroxyphenyl) undecanyl -N'-n-tetracontyloxamide, N- [11- (p-hydroxyphenyl) undecanyl] -N'-n-pentacontyloxamide; N- [p- (p-hydroxyphenyl) phenyl]- N'-n-octadecyloxamide, N- [p- (p-hydroxyphenyl) phenyl] -N'-n-docosyloxamide, N- [p- (p-hydroxyphenyl) phenyl] -N'- n-hexacosyl oxamide, N- [p- (p-hydroxyphenyl) phenyl] -N'-n-triacontyl oxamide, N- [p- (p-hydroxyphenyl) phenyl] -N'- n-hexatriacontyl oxamide, N- [p- (p-hydroxyphenyl) phenyl] -N'-n-tetracontyl oxamide, N- [p- (p-hydroxyphenyl) Eniru]-N'-n-penta con chill oxamide;

  N- [2- (p-hydroxyphenyl) acetyl] -N'-n-dodecylurea, N- [2- (p-hydroxyphenyl) acetyl] -N'-n-octadecylurea, N- [2- ( p-hydroxyphenyl) acetyl] -N'-n-docosylurea, N- [2- (p-hydroxyphenyl) acetyl] -N'-n-hexacosylurea, N- [2- (p-hydroxyphenyl) acetyl ] -N'-n-triacontylurea, N- [2- (p-hydroxyphenyl) acetyl] -N'-n-hexatriacontylurea, N- [2- (p-hydroxyphenyl) acetyl] -N '-N-tetracontylurea, N- [2- (p-hydroxyphenyl) acetyl] -N'-n-pentacontylurea; N- [3- (p-hydroxyphenyl) propionyl]- '-N-octadecylurea, N- [3- (p-hydroxyphenyl) propionyl] -N'-n-docosylurea, N- [3- (p-hydroxyphenyl) propionyl] -N'-n-hexacosylurea N- [3- (p-hydroxyphenyl) propionyl] -N'-n-triacontylurea, N- [3- (p-hydroxyphenyl) propionyl] -N'-n-hexatriacontylurea, N- [3- (p-hydroxyphenyl) propionyl] -N′-n-tetracontylurea, N- [3- (p-hydroxyphenyl) propionyl] -N′-n-pentacontylurea; N- [p- (p -Hydroxyphenyl) benzoyl] -N'-n-octadecylurea, N- [p- (p-hydroxyphenyl) benzoyl] -N'-n-docosylurine N- [p- (p-hydroxyphenyl) benzoyl] -N'-n-hexacosylurea, N- [p- (p-hydroxyphenyl) benzoyl] -N'-n-triacontylurea, N- [ p- (p-hydroxyphenyl) benzoyl] -N'-n-hexatriacontylurea, N- [p- (p-hydroxyphenyl) benzoyl] -N'-n-tetracontylurea, N- [p- ( p-hydroxyphenyl) benzoyl] -N'-n-pentacontylurea;

  N- [2- (p-hydroxyphenyl) ethyl] -N'-n-dodecanoyl urea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-octadecanoyl urea, N- [2 -(P-hydroxyphenyl) ethyl] -N'-n-docosanoyl urea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-hexacosanoyl urea, N- [2- (p-hydroxyphenyl) ) Ethyl] -N'-n-triacontanoylurea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-hexatriacontanoylurea, N- [2- (p-hydroxyphenyl) Ethyl] -N'-n-tetracontanoylurea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-pentacontanoylurea; N- [p- (p-hydroxyphenyl) Nenyl] -N'-n-octadecanoyl urea, N- [p- (p-hydroxyphenyl) phenyl] -N'-n-docosanoyl urea, N- [p- (p-hydroxyphenyl) phenyl] -N '-N-hexacosanoyl urea, N- [p- (p-hydroxyphenyl) phenyl] -N'-n-triacontanoyl urea, N- [p- (p-hydroxyphenyl) phenyl] -N'-n- Hexatriacontanoyl urea, N- [p- (p-hydroxyphenyl) phenyl] -N'-n-tetracontanoylurea, N- [p- (p-hydroxyphenyl) phenyl] -N'-n-pentacon Tanoylurea; 4- [2- (p-hydroxyphenyl) ethyl] -1-n-tetradecylsemicarbazide, 4- [2- (p-hydroxyphenyl) ethyl] -1- -Octadecyl semicarbazide, 4- [2- (p-hydroxyphenyl) ethyl] -1-n-docosyl semicarbazide, 4- [2- (p-hydroxyphenyl) ethyl] -1-n-hexacosyl semicarbazide, 4 -[2- (p-hydroxyphenyl) ethyl] -1-n-triacontyl semicarbazide, 4- [2- (p-hydroxyphenyl) ethyl] -1-n-hexatriacontyl semicarbazide, 4- [2 -(P-hydroxyphenyl) ethyl] -1-n-hexacontyl semicarbazide, 4- [2- (p-hydroxyphenyl) ethyl] -1-n-pentacontyl semicarbazide;

  4- [p- (p-hydroxyphenyl) phenyl] -1-n-tetradecyl semicarbazide, 4- [p- (p-hydroxyphenyl) phenyl] -1-n-octadecyl semicarbazide, 4- [p- (p -Hydroxyphenyl) phenyl] -1-n-docosyl semicarbazide, 4- [p- (p-hydroxyphenyl) phenyl] -1-n-hexacosyl semicarbazide, 4- [p- (p-hydroxyphenyl) phenyl ] -1-n-triacontyl semicarbazide, 4- [p- (p-hydroxyphenyl) phenyl] -1-n-hexatriacontyl semicarbazide, 4- [p- (p-hydroxyphenyl) phenyl] -1 -N-tetracontyl semicarbazide, 4- [p- (p-hydroxyphenyl) phenyl] -1-n-pentacontyl Micarbazide; 1- [2- (p-hydroxyphenyl) ethyl] -4-n-tetradecyl semicarbazide, 1- [2- (p-hydroxyphenyl) ethyl] -4-n-octadecyl semicarbazide, 1- [2- (P-hydroxyphenyl) ethyl] -4-n-docosyl semicarbazide, 1- [2- (p-hydroxyphenyl) ethyl] -4-n-hexacosyl semicarbazide, 1- [2- (p-hydroxyphenyl) ) Ethyl] -4-n-triacontyl semicarbazide, 1- [2- (p-hydroxyphenyl) ethyl] -4-n-hexatriacontyl semicarbazide, 1- [2- (p-hydroxyphenyl) ethyl] -4-n-tetracontyl semicarbazide, 1- [2- (p-hydroxyphenyl) ethyl] -4-n-pentacontyl Mikarubajido;

  1- [p- (p-hydroxyphenyl) phenyl] -4-n-tetradecyl semicarbazide, 1- [p- (p-hydroxyphenyl) phenyl] -4-n-octadecyl semicarbazide, 1- [p- (p -Hydroxyphenyl) phenyl] -4-n-docosyl semicarbazide, 1- [p- (p-hydroxyphenyl) phenyl] -4-n-hexacosyl semicarbazide, 1- [p- (p-hydroxyphenyl) phenyl ] -4-n-triacontyl semicarbazide, 1- [p- (p-hydroxyphenyl) phenyl] -4-n-hexatriacontyl semicarbazide, 1- [p- (p-hydroxyphenyl) phenyl] -4 -N-tetracontyl semicarbazide, 1- [p- (p-hydroxyphenyl) phenyl] -4-n-pentacontyl Micarbazide; 1- [2- (p-hydroxyphenyl) acetyl] -4-n-tetradecyl semicarbazide, 1- [2- (p-hydroxyphenyl) acetyl] -4-n-octadecyl semicarbazide, 1- [2- (P-hydroxyphenyl) acetyl] -4-n-docosyl semicarbazide, 1- [2- (p-hydroxyphenyl) acetyl] -4-n-hexacosyl semicarbazide, 1- [2- (p-hydroxyphenyl) ) Acetyl] -4-n-triacontyl semicarbazide, 1- [2- (p-hydroxyphenyl) acetyl] -4-n-hexatriacontyl semicarbazide, 1- [2- (p-hydroxyphenyl) acetyl] -4-n-tetracontyl semicarbazide, 1- [2- (p-hydroxyphenyl) acetyl] -4-n Pentacontyl semicarbazide; 1- [3- (p-hydroxyphenyl) propionyl] -4-n-octadecyl semicarbazide, 1- [3- (p-hydroxyphenyl) propionyl] -4-n-docosyl semicarbazide, 1- [ 3- (p-hydroxyphenyl) propionyl] -4-n-hexacosyl semicarbazide, 1- [3- (p-hydroxyphenyl) propionyl] -4-n-triacontyl semicarbazide, 1- [3- (p -Hydroxyphenyl) propionyl] -4-n-hexatriacontyl semicarbazide, 1- [3- (p-hydroxyphenyl) propionyl] -4-n-tetracontyl semicarbazide, 1- [3- (p-hydroxyphenyl) ) Propionyl] -4-n-pentacontyl semicarbazide;

  1- [11- (p-hydroxyphenyl) undecanoyl] -4-n-decyl semicarbazide, 1- [11- (p-hydroxyphenyl) undecanoyl] -4-n-tetradecyl semicarbazide, 1- [11- (p -Hydroxyphenyl) undecanoyl] -4-n-octadecylsemicarbazide, 1- [11- (p-hydroxyphenyl) undecanoyl] -4-n-docosylsemicarbazide, 1- [11- (p-hydroxyphenyl) undecanoyl]- 4-n-hexacosyl semicarbazide, 1- [11- (p-hydroxyphenyl) undecanoyl] -4-n-triacontyl semicarbazide, 1- [11- (p-hydroxyphenyl) undecanoyl] -4-n- Hexatriacontyl semicarbazide, 1- [11- (p-hydride Xylphenyl) undecanoyl] -4-n-tetracontyldecyl semicarbazide, 1- [11- (p-hydroxyphenyl) undecanoyl] -4-n-pentacontyl semicarbazide; 1- [p- (p-hydroxyphenyl) benzoyl] -4-n-octadecyl semicarbazide, 1- [p- (p-hydroxyphenyl) benzoyl] -4-n-docosyl semicarbazide, 1- [p- (p-hydroxyphenyl) benzoyl] -4-n-hexakoshi Rusemicarbazide, 1- [p- (p-hydroxyphenyl) benzoyl] -4-n-triacontyl semicarbazide, 1- [p- (p-hydroxyphenyl) benzoyl] -4-n-hexatriacontyl semicarbazide, 1- [p- (p-hydroxyphenyl) benzoyl] -4-n- Tracontyl semicarbazide, 1- [p- (p-hydroxyphenyl) benzoyl] -4-n-pentacontyl semicarbazide; 4- [2- (p-hydroxyphenyl) ethyl] -1-n-tetradecanoyl semicarbazide, 4 -[2- (p-hydroxyphenyl) ethyl] -1-n-octadecanoyl semicarbazide, 4- [2- (p-hydroxyphenyl) ethyl] -1-n-docosanoyl semicarbazide, 4- [2- ( p-hydroxyphenyl) ethyl] -1-n-hexacosanoyl semicarbazide, 4- [2- (p-hydroxyphenyl) ethyl] -1-n-triacontanoyl semicarbazide, 4- [2- (p-hydroxyphenyl) ) Ethyl] -1-n-hexatriacontanoyl semicarbazide, 4- [2- (p-hydroxyl) Enyl) ethyl] -1-n-tetracontanoyl semicarbazide, 4- [2- (p-hydroxyphenyl) ethyl] -1-n-pentacontanoyl semicarbazide;

  4- [p- (p-hydroxyphenyl) phenyl] -1-n-octadecanoyl semicarbazide, 4- [p- (p-hydroxyphenyl) phenyl] -1-n-docosanoyl semicarbazide, 4- [p- (P-hydroxyphenyl) phenyl] -1-n-hexacosanoyl semicarbazide, 4- [p- (p-hydroxyphenyl) phenyl] -1-n-triacontanoyl semicarbazide, 4- [p- (p-hydroxy) Phenyl) phenyl] -1-n-hexatriacontanoyl semicarbazide, 4- [p- (p-hydroxyphenyl) phenyl] -1-n-tetracontanoyl semicarbazide, 4- [p- (p-hydroxyphenyl) phenyl ] -1-n-pentacontanoyl semicarbazide; pn-octadecanoylaminomethylphenol , Pn-docosanoylaminomethylphenol, pn-hexacosanoylaminomethylphenol, pn-triacontanoylaminomethylphenol, pn-hexatricontanoylaminomethylphenol, pn -Tetracontanoylaminomethylphenol, pn-pentacontanoylaminomethylphenol; pn-octadecanoylaminoethylphenol, pn-docosanoylaminoethylphenol, pn-hexacosanoylaminoethylphenol , Pn-triacontanoylaminoethylphenol, pn-hexatricontanoylaminoethylphenol, pn-tetracontanoylaminoethylphenol, pn-pentacontanoylaminoethylphenol;

  N- (p-hydroxyphenyl) methyl-N'-n-dodecylurea, N- (p-hydroxyphenyl) methyl-N'-n-octadecylurea, N- (p-hydroxyphenyl) methyl-N'-n -Docosylurea, N- (p-hydroxyphenyl) methyl-N'-n-hexacosylurea, N- (p-hydroxyphenyl) methyl-N'-n-triacontylurea, N- (p-hydroxyphenyl) methyl- N'-n-hexatriacontylurea, N- (p-hydroxyphenyl) methyl-N'-n-tetracontylurea, N- (p-hydroxyphenyl) methyl-N'-n-pentacontylurea; N- [2- (p-hydroxyphenyl) ethyl] -N'-n-dodecylurea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-octa Silurea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-docosylurea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-hexacosylurea, N- [ 2- (p-hydroxyphenyl) ethyl] -N'-n-triacontylurea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-hexatriacontylurea, N- [2- ( p-hydroxyphenyl) ethyl] -N'-n-tetracontylurea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-pentacontylurea; pn-octadecyloxycarbonylaminomethylphenol, pn-docosyloxycarbonylaminomethylphenol, pn-hexacosyloxycarbonylaminomethylphenol, pn-triacontylthio Aryloxycarbonyl amino methyl phenol, p-n-hexa triacontyl butyloxycarbonylamino-methylphenol, p-n-tetra-con chill butyloxycarbonylamino-methylphenol, p-n-penta con chill butyloxycarbonylamino-methyl phenol; and the like.

  As the reversible developer according to the present invention, compounds represented by the following general formulas 5 and 6 can also be used.

In general formula 5, a represents an integer of 0 or 1. T ¹ and T ² each independently represent a member selected from a hydrogen atom, a methyl group and a phenyl group, and T ³ represents a member selected from a hydrogen atom, a methyl group, a phenyl group and a trifluoromethyl group. . T ⁴ and T ⁵ each independently represent a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms, and T ⁶ represents a monovalent linear aliphatic group having 8 to 50 carbon atoms. Y ¹ and Y ² each independently represent a single bond or a member selected from divalent groups represented by the following (2-1) to (2-23), and Y ¹ and Y ² are simultaneously selected. Does not include those that are single bonds. In addition, when the divalent groups represented by (2-1) to (2-23) are not bilaterally symmetric, these groups are bonded to the groups adjacent to the compound represented by Formula 5 in the same direction. It may be bonded to the groups on both sides in a horizontally reversed manner.

In General Formula 6, b represents an integer of 1 or 2, and c represents an integer of 1 to 3. T ⁷ and T ⁸ each independently represent a member selected from a hydrogen atom, a methyl group and a phenyl group, and T ⁹ and T ¹⁰ each independently represent a single bond or a divalent hydrocarbon having 1 to 20 carbon atoms. T ¹¹ represents a hydrogen atom or a monovalent linear aliphatic group having 1 to 50 carbon atoms. Y ³ and Y ⁴ each independently represent a single bond or a member selected from divalent groups represented by the following (2-1) to (2-23), and Y ³ and Y ⁴ are simultaneously Does not include those that are single bonds. In addition, when the divalent groups represented by (2-1) to (2-23) are not bilaterally symmetric, these groups are bonded to the groups adjacent to the compound represented by Formula 6 in the same direction. It may be bonded to the groups on both sides in a horizontally reversed manner.

In Y ¹ and Y ³ , preferred divalent groups include (2-18) to (2-23), and (2-18) and (2-21) are particularly preferred.

  The amount of the reversible developer used in the present invention is usually 5 to 5000% by mass, preferably 10 to 3000% by mass, based on a colorless or light-colored dye precursor. 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 according to the present invention is formed by applying a heat-sensitive recording layer coating solution containing at least a dye precursor, a reversible developer, a polyol compound, and various polyisocyanate compounds on at least one surface of a support. It is formed by filming. As a method for including the dye precursor and the reversible developer in the heat-sensitive recording layer coating solution, each compound is dissolved in a solvent alone or dispersed in a dispersion medium, and then mixed. A method of dissolving in a solvent or dispersing in a dispersion medium after combining, a method in which each compound is heated and dissolved, homogenized and then cooled, dissolved in a solvent or dispersed in a dispersion medium, etc. Absent. If necessary, a dispersing agent may be used during dispersion. As a dispersion medium, the compound illustrated as a dilution solvent of the said polyol compound and various polyisocyanate compounds can be used. Among these, it is preferable to use an organic solvent that does not have an active hydrogen group such as a hydroxyl group, an amino group, or a carboxyl group.

  In the reversible heat-sensitive recording material of the present invention, the heat-sensitive recording layer has an accelerating erasure in order to cope with high-speed erasure printing required for reversible heat-sensitive recording materials, or to improve background whiteness and suppress erasure fog. An agent can be added. The erasing accelerator can be used alone or in combination of two or more. Examples of the erasure accelerator include compounds represented by the following general formulas 7 to 10. The use amount of the erasure accelerator is 0.05 to 1000 parts by mass, preferably 0.05 to 500 parts by mass, and more preferably 0.1 to 200 parts by mass with respect to 100 parts by mass of the dye precursor. If there are too few erasure accelerators with respect to the dye precursor, the erasability (erase accelerating properties) tends to deteriorate, and conversely, if there are too many erasing accelerators, the color density tends to decrease due to the dilution effect.

In the general formula 7, R ⁸ represents a monovalent hydrocarbon group having 6 to 50 carbon atoms. R ⁸ preferably has 14 to 42 carbon atoms, more preferably 18 to 38 carbon atoms. R ⁹ represents a divalent hydrocarbon group having 1 to 36 carbon atoms. R ⁹ preferably has 1 to 22 carbon atoms, more preferably 1 to 12 carbon atoms. X ⁴ represents a divalent group containing an oxygen atom, a sulfur atom, SO, SO ₂ , CH═N, N═CH, NR ′, CS, NH or CO. R ′ represents a monovalent hydrocarbon group having 1 to 50 carbon atoms. X ⁵ represents a monovalent group containing an oxygen atom, a sulfur atom, SO ₂ , NH or CO. X ⁵ is preferably —CONH ₂ or —CONHNH ₂ . n ₁ represents an integer of 0 to 3. When n ₁ is 2 or 3, the repeated X ⁴ and R ⁹ may be the same or different.

In General Formula 8, R ¹⁰ and R ¹² each independently represent a monovalent hydrocarbon group having 1 to 50 carbon atoms. R ¹⁰ and R ¹² preferably have 14 to 42 carbon atoms, more preferably 18 to 38 carbon atoms. R ¹¹ represents a C1-C36 divalent hydrocarbon group. R ¹¹ preferably has 1 to 22 carbon atoms, more preferably 1 to 12 carbon atoms. X ⁶ and X ⁷ each represents a divalent group having at least one of —O—, —S—, —SO—, —SO ₂ —, —NH— or —CO—. n ₂ represents an integer of 0 to 4, and when n ₂ is an integer of 2 or more, R ¹¹ and X ^{7 that} are repeated may be the same or different.

In General Formula 9, A ¹ represents a monovalent group consisting of a substituted or unsubstituted heterocycle having at least one nitrogen atom, or an acyclic monovalent amino group excluding an —NH ₂ group. R ¹³ and R ¹⁴ each independently represents a divalent hydrocarbon group having 1 to 36 carbon atoms. R ¹⁵ represents a monovalent hydrocarbon group having 1 to 50 carbon atoms. X ⁸ and X ⁹ each independently represents a divalent group having at least one of —O—, —S—, —CO—, —NH—, —SO— or —SO ₂ —. n ₃ represents 0 or 1. n ₄ represents an integer of 0-4. When n ₄ is 2 or more, the repeated X ⁸ and R ¹⁴ may be the same or different. Provided that n ₃ = n ₄ = 0, X ⁹ is a —CO— group, and the nitrogen atom in A ¹ is directly bonded to X ⁹ , or n ₃ = 0, n ₄ = 1 to 4, A ^The compound in which X ⁸ bonded to ¹ is a —CO— group and the nitrogen atom in A ¹ is directly bonded to X ⁸ is excluded.

In the general formula 10, R ¹⁶ represents a monovalent hydrocarbon group having 1 to 50 carbon atoms. R ¹⁷ represents a divalent hydrocarbon group having 1 to 36 carbon atoms. R ¹⁸ and R ¹⁹ each independently represents a saturated or unsaturated hydrocarbon group which may have a substituent having 1 to 50 carbon atoms. R ¹⁸ and R ¹⁹ may form a ring, and the formed ring may be via a nitrogen atom, an oxygen atom or a sulfur atom. The ring may be a heterocyclic ring. X ¹⁰ represents a divalent group having at least one group of any of —NHCO—, —NHCS—, and —NHSO ₂ —. n ₅ represents an integer of 1-4. When n ₅ is 2 or more, the repeated X ¹⁰ and R ¹⁷ may be the same or different.

  A preferable use amount of the erasing accelerator is 0.1% by mass or more and 1000% by mass or less, and more preferably 0.5% by mass or more and 200% by mass or less with respect to the reversible developer. Furthermore, if considering the heat-resistant storage stability of the printed image, 1% by mass or more and 100% by mass or less is particularly preferable. The erasing accelerator can be used alone or in combination of two or more.

  In order to adjust the color development sensitivity and decoloring temperature of the heat-sensitive recording layer, a heat-fusible substance can be contained in 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 in general heat-sensitive recording materials 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) ( and carbonic acid or oxalic acid diester derivatives such as p-methylbenzyl) ester. These compounds can also be added in combination.

  For the purpose of preventing aging of the heat-sensitive recording layer, 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. Anti-aging 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, triazine compounds, benzophenone compounds, benzoates and the like. 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.

  A pigment or the like can be added to the heat-sensitive recording layer according to the present invention as long as the object of the present invention is not hindered. For example, inorganic pigments containing carbonates such as aluminum, zinc, calcium, magnesium, barium, titanium, oxides, hydroxides, sulfates, and clays such as zeolite, silica, kaolin, calcined kaolin, talc, Starch, styrene resin, polyolefin resin, urea-formalin resin, melamine resin, acrylic resin, paraffin, natural wax, synthetic wax and the like can be used. Further, higher fatty acid metal salts such as zinc stearate and calcium stearate can be used as a lubricant.

  The film thickness of the heat-sensitive recording layer according to the present invention is determined by the composition of the heat-sensitive recording layer and the desired color density, and specifically, the range of 0.5 to 20 μm is preferable, and 3 to 15 μm is more preferable. .

  In the present invention, it is preferable to provide a protective layer on the surface opposite to the support of the heat-sensitive recording layer for the purpose of enhancing durability during repeated use. The protective layer is preferably composed of a curable resin such as a thermosetting resin, an electron beam curable resin, or an ultraviolet curable resin, and particularly preferably an electron beam curable resin or an ultraviolet curable resin. As the curable resin, the compounds exemplified as the binder usable in the heat-sensitive recording layer can be used. Further, for the purpose of further improving the durability or adjusting the glossiness, a pigment may be blended, or a higher fatty acid metal salt may be blended as a lubricant. As the pigment and the higher fatty acid metal salt, the compounds exemplified in the heat-sensitive recording layer can be used.

  The thickness of the protective layer is preferably in the range of 0.1 to 10 μm, more preferably 0.5 to 5 μm. When the film thickness exceeds 10 μm, not only the effect is saturated, but also the sensitivity of the thermosensitive recording layer tends to decrease. When the film thickness is smaller than 0.1 μm, it is difficult to obtain the expected coating layer strength, and the coating layer is easily damaged.

  As the support used in the reversible thermosensitive recording material of the present invention, paper, coated paper, various nonwoven fabrics, woven fabrics, synthetic resin films such as polyethylene terephthalate and polypropylene, paper laminated with synthetic resins such as polyethylene and polypropylene, Synthetic paper, metal foil, glass, etc., or a composite sheet combining them can be used arbitrarily depending on the purpose, but is not limited to these, and these are either opaque, translucent or transparent. May be. In order to make the background appear white or other specific colors, a white pigment, a colored dye pigment, or air bubbles may be included in the support or on the surface. In addition, surface treatment by corona discharge or the like may be applied to films or the like, or easy adhesion treatment such as application of water-soluble polymers exemplified as a binder to the support surface may be performed. Further, once the heat-sensitive recording layer according to the present invention is provided on a support, it may be transferred to another support via an adhesive layer in some cases. The thickness of the support according to the present invention is not particularly limited as long as it can withstand repeated use, but is 20 to 1300 μm, preferably 40 to 1000 μm.

  In the present invention, an intermediate layer composed of an ultraviolet absorber, an antioxidant, or the like is provided between the heat-sensitive recording layer and the protective layer for the purpose of improving weather resistance or the like. A coat layer may be provided. In addition, a backcoat layer may be provided on the surface opposite to the surface on which the heat-sensitive recording layer is provided for the purpose of preventing curling or charging, or a layer capable of magnetically recording information may be provided. For example, a material that can be electrically and optically recorded with information may be included between another substrate and another substrate. Further, printing with UV ink or the like may be performed on an arbitrary layer and / or support in the reversible thermosensitive recording material.

  In the present invention, an optional layer provided on the support may be provided with a leveling agent, a dispersant, a surfactant, a hardener, an antiseptic, a dye, a fluorescent dye, and an ultraviolet absorber as necessary in addition to the above components. Various additives such as antioxidants, anti-aging agents, pH adjusters, and antifoaming agents can be added. In the present invention, the arbitrary layer provided on the support may be a multilayer of two or more layers by containing each component one by one or changing the blending ratio for each layer.

  In the reversible thermosensitive recording material of the present invention, a photothermal conversion material can be contained in any layer and / or support in the reversible thermosensitive recording material in order to perform printing / erasing with a laser beam.

  The method for laminating each layer in the present invention on a support to form a reversible thermosensitive recording material is not particularly limited, and can be formed by a conventional method. For example, air knife coater, blade coater, bar coater, curtain coater, gravure roll and transfer roll coater, roll coater, comma coater, smoothing coater, micro gravure coater, reverse roll coater, 4 roll roll coater, dip coater, Various coating machines such as a rod coater, a kiss coater, a gate roll coater, a squeeze coater, a slide coater, a die coater, and other smearing apparatuses, a lithographic plate, a relief plate, an intaglio plate, a flexo, a gravure, a screen, and a hot melt can be used. Furthermore, each layer can be held by ultraviolet irradiation or electron beam irradiation in addition to a normal drying process. By these methods, it is possible to apply and print one layer at a time or multiple layers simultaneously.

  In the reversible thermosensitive recording material of the present invention, rapid cooling is required following heating to form a color-recorded recording image, and a slow cooling rate after heating is sufficient to erase the recorded image. 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. In addition, if the heating is performed for a very short time using a thermal head, laser light, or the like, the cooling is performed immediately after the heating is completed, so that the colored state can be maintained. On the other hand, when heated for a relatively long time with a suitable heat source (thermal head, laser light, 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 and the like are 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 the same heat source are used, the coloring state and the decoloring state can be arbitrarily expressed by controlling the cooling rate.

  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.

(1) Preparation of thermal recording layer coating solution 3-Diethylamino-6-methyl-7-p-tolylaminofluorane (dye precursor / acetic acid / acetone active ingredient ratio (mass ratio) 2/6 as a dye precursor 20 parts of the maximum absorbance (hereinafter simply referred to as maximum absorbance) 2.0 / 450 nm) of the absorption spectrum of the solution designated as / 92, 100 parts of the following compound (3-1) as a reversible developer, caprolactone A mixture of 50 parts of polyol (trade name “TONE0301”, nonvolatile content 100% by mass, acid value 0.2, OH value 560 mg KOH / g, manufactured by Dow Chemical Co., Ltd.) and 980 parts of methyl ethyl ketone as a solvent together with glass beads in a paint shaker 24 A dispersion was obtained by time dispersion. In the dispersion thus obtained, as an araliphatic polyisocyanate compound, a compound in which R ² = ethyl group in the above general formula 2 (trade name “Takenate D-110N”, non-volatile content 75% by mass, Mitsui Chemicals Polyurethane Industry Co., Ltd.) 170 parts, as an aromatic polyisocyanate compound, 30 parts of the following compound (4-1) (trade name “Coronate L”, non-volatile content: 75% by mass, manufactured by Nippon Polyurethane Industry Co., Ltd.) are added and mixed well, and heat sensitive. A recording layer coating solution was prepared. The blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

(2) Preparation of intermediate layer coating solution 50 parts of UV absorber (trade name “Tinubin 328”, manufactured by Ciba Specialty Chemicals), polyester polyol (trade name “Bernock 11-408”, nonvolatile content 70% by mass) A mixture of 100 parts of Dainippon Ink Chemical Co., Ltd. and 800 parts of methyl ethyl ketone was dispersed with glass beads for 5 hours with a paint shaker to obtain a dispersion. To the dispersion thus obtained, 140 parts of an isocyanate compound (trade name “Takenate D-110N”, non-volatile content 75 mass%, manufactured by Mitsui Chemicals Polyurethane Industry Co., Ltd.) and 50 parts of methyl ethyl ketone were added and mixed well. Prepared.

(3) Preparation of coating solution for protective layer 100 parts of urethane acrylate UV curable resin (trade name “Unidic V-4205”, manufactured by Dainippon Ink & Chemicals, Inc.), silica particles having an average particle size of 1.2 μm ( A product name “Nip Seal SS-50F” (manufactured by Tosoh Silica Co., Ltd.) 10 parts and 90 parts of isopropyl alcohol were mixed well to prepare a protective layer coating solution.

(4) Preparation of adhesive layer coating solution 30 parts of saturated polyester resin (trade name “PES-355S30”, manufactured by Toagosei Co., Ltd.), 56 parts of toluene, 14 parts of methyl ethyl ketone, and polyhydric alcohol fatty acid ester (trade name “SL” 02 ", manufactured by Riken Vitamin Co., Ltd.) was mixed well to prepare an adhesive layer coating solution.

(5) Production of reversible thermosensitive recording material The thermosensitive recording layer coating solution obtained in (1) was applied to a white polyethylene terephthalate (PET) sheet having a thickness of 188 μm so that the dry film thickness was 8 μm, and 120 ° C. And dried at 50 ° C. for 48 hours to form a thermosensitive recording layer. On the heat-sensitive recording layer, the intermediate layer coating solution obtained in (2) was applied so that the dry film thickness was 1 μm, dried at 120 ° C. for 1 minute, and further heated at 50 ° C. for 48 hours. A layer was formed. After coating the protective layer coating solution obtained in (3) on the intermediate layer, it is cured by passing it under a UV lamp with an irradiation energy of 80 W / cm at a conveyance speed of 9 m / min, and the film thickness after dry curing is 3 μm. The protective layer was provided. Further, the adhesive layer coating liquid obtained in (4) was applied to the non-coated surface of the support so that the dry film thickness was 10 μm, and dried at 80 ° C. for 3 minutes, whereby the reversible thermosensitive recording material of the present invention. Got.

  Example 1 (1) In the preparation of the heat-sensitive recording layer coating solution, the reversible thermosensitive property of the present invention was changed by changing the blended part of the araliphatic polyisocyanate compound to 150 parts and the blended part of the aromatic polyisocyanate compound to 50 parts. A recording material was obtained. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 75/25.

  Example 1 (1) In the preparation of the heat-sensitive recording layer coating solution, the reversible thermosensitive property of the present invention was changed by changing the blending part of the araliphatic polyisocyanate compound to 186 parts and the blending part of the aromatic polyisocyanate compound to 14 parts. A recording material was obtained. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 93/7.

  Example 1 (1) In the preparation of a heat-sensitive recording layer coating solution, an isocyanurate type polyisocyanate compound (trade name “Sumijoule FL-3”, nonvolatile content 51 formed by trimming an aromatic polyisocyanate compound with toluene diisocyanate. %, Manufactured by Sumika Bayer Urethane Co., Ltd.) 44 parts, to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

Example 1 (1) In the preparation of the heat-sensitive recording layer coating liquid, the araliphatic polyisocyanate compound was changed to a compound (nonvolatile content 75% by mass) in which R ² = methyl group in the general formula 2 above. A reversible thermosensitive recording material was obtained. The blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  Example 1 (1) In the preparation of the thermal recording layer coating solution, the araliphatic polyisocyanate compound was changed to the above compound (4-2) (nonvolatile content: 75% by mass), and the reversible thermosensitive recording material of the present invention was used. Obtained. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  Example 1 (1) In the preparation of the thermal recording layer coating solution, caprolactone polyol was changed to 45 parts of polyether polyol (trade name “Polyol 4640”, nonvolatile content 100 mass%, OH number 630 mg KOH / g, manufactured by Perstorp). Thus, a reversible thermosensitive recording material of the present invention was obtained. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  Example 1 (1) In the preparation of the heat-sensitive recording layer coating solution, caprolactone polyol was changed to 80 parts of polyester polyol (non-volatile content 70% by mass, acid value <5.0, OH value 480 mgKOH / g), and the reversible of the present invention. A heat-sensitive recording material was obtained. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  Example 1 (1) In the preparation of a heat-sensitive recording layer coating solution, caprolactone polyol was changed to polyester polyol (trade name “Takelac U-21”, nonvolatile content 70% by mass, acid value <4.2, OH value 350 mgKOH / g, Mitsui The product was changed to 110 parts by Chemical Polyurethane Co., Ltd. to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  Example 1 (1) In the preparation of the thermal recording layer coating solution, the dye precursor was changed to 3-diethylamino-6-methyl-7- (2 ', 4'-xylylamino) fluorane (maximum absorbance 2.7 / 584 nm) Thus, a reversible thermosensitive recording material of the present invention was obtained. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  Example 1 (1) In the preparation of the thermal recording layer coating solution, the dye precursor was 3-N-ethyl-N- (3'-ethoxypropyl) amino-6-methyl-7-phenylaminofluorane (maximum absorbance 1). , 586 nm) to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  Example 1 (1) In the preparation of the thermal recording layer coating solution, the dye precursor was changed to 3-diethylamino-7- (3′-trifluoromethylphenylamino) fluorane (maximum absorbance 0.5, 580 nm). The reversible thermosensitive recording material of the invention was obtained. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  Example 1 (1) In the preparation of the thermal recording layer coating solution, 5 parts of behenamide was added as an erasure accelerator during the preparation of the dispersion to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  Example 1 (1) In the preparation of the thermosensitive recording layer coating solution, 5 parts of the following compound was added as an erasing accelerator during the preparation of the dispersion to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  In Example 1, the compound (3-1) was changed to the compound (3-2) as a reversible developer to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  In Example 1, the compound (3-1) was changed to the compound (3-3) as a reversible developer to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  In Example 1, the compound (3-1) was changed to the compound (3-4) as a reversible developer to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  In Example 1, the compound (3-1) was changed to the compound (3-5) as a reversible developer to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  In Example 1, the compound (3-1) was changed to the compound (3-6) as a reversible developer to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

  In Example 1, the compound (3-1) was changed to the compound (3-7) as a reversible developer to obtain a reversible thermosensitive recording material of the present invention. The blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 85/15.

Comparative Example 1
Example 1 (1) In the preparation of the heat-sensitive recording layer coating solution, the reversible thermosensitive recording material was prepared by changing the blended part of the araliphatic polyisocyanate compound to 196 parts and the blended part of the aromatic polyisocyanate compound to 4 parts. Obtained. The blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 98/2.

Comparative Example 2
Example 1 (1) In the preparation of the thermosensitive recording layer coating solution, the reversible thermosensitive recording material was prepared by changing the blended part of the araliphatic polyisocyanate compound to 130 parts and the blended part of the aromatic polyisocyanate compound to 70 parts. Obtained. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 65/35.

Comparative Example 3
Example 1 (1) In the preparation of the thermal recording layer coating solution, a reversible thermosensitive recording material was obtained without using an araliphatic polyisocyanate compound and changing the blending number of the aromatic polyisocyanate compound to 200 parts. . The blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 0/100.

Comparative Example 4
Example 1 (1) In the preparation of the heat-sensitive recording layer coating liquid, instead of the araliphatic polyisocyanate compound and the aromatic polyisocyanate compound, an aliphatic polyisocyanate compound (trade name “Duranate P-301-75E”, adduct type A reversible thermosensitive recording material was obtained using 200 parts of a hexamethylene diisocyanate compound (non-volatile content: 75% by mass, manufactured by Asahi Kasei Chemicals Corporation).

Comparative Example 5
Example 1 (1) In the preparation of the heat-sensitive recording layer coating solution, an alicyclic aliphatic polyisocyanate compound (trade name “Takenate D-120N”, adduct-type hydrogenated xylylene diisocyanate was used instead of the araliphatic polyisocyanate compound. A reversible thermosensitive recording material was obtained using a compound, a non-volatile content of 75% by mass, manufactured by Mitsui Chemicals Polyurethane Industry Co., Ltd. The blending ratio of alicyclic aliphatic polyisocyanate compound / aromatic polyisocyanate compound (mass ratio of nonvolatile content) is 85/15.

Comparative Example 6
Example 1 (1) In the preparation of the heat-sensitive recording layer coating liquid, instead of the araliphatic polyisocyanate compound, an aliphatic polyisocyanate compound (trade name “Duranate P-301-75E”, an adduct-type hexamethylene diisocyanate compound, Using a non-volatile content of 75% by mass, manufactured by Asahi Kasei Chemicals Corporation, a reversible thermosensitive recording material was obtained. The blending ratio of aliphatic polyisocyanate compound / aromatic polyisocyanate compound (mass ratio of nonvolatile content) is 85/15.

Comparative Example 7
Example 1 (1) In the preparation of the heat-sensitive recording layer coating solution, an aliphatic polyisocyanate compound (trade name “Duranate P-301-75E”, adduct-type hexamethylene diisocyanate compound, non-volatile content 75% by mass as the polyisocyanate compound. 170 parts of Asahi Kasei Chemicals Corporation, aromatic polyisocyanate compound (trade name “Sumijour FL-3”, isocyanurate type polyisocyanate compound formed by trimerization of toluene diisocyanate, non-volatile content 51%, Reversible thermosensitive recording material was obtained using 44 parts of Kabayer Urethane Co., Ltd. The blending ratio of aliphatic polyisocyanate compound / aromatic polyisocyanate compound (mass ratio of nonvolatile content) is 85/15.

Comparative Example 8
Example 1 (1) In the preparation of the heat-sensitive recording layer coating solution, an aliphatic polyisocyanate compound (trade name “Duranate P-301-75E”, adduct-type hexamethylene diisocyanate compound, non-volatile was used instead of the aromatic polyisocyanate compound. A reversible thermosensitive recording material was obtained using 75% by mass of Asahi Kasei Chemicals Corporation. The blending ratio (mass ratio of nonvolatile content) of the araliphatic polyisocyanate compound / aliphatic polyisocyanate compound is 85/15.

Comparative Example 9
Example 1 (1) In the preparation of a thermal recording layer coating solution, the dye precursor was changed to 3-diethylamino-6-methyl-7- (2 ', 4'-xylylamino) fluorane (maximum absorbance 2.7 / 584 nm) Then, the blending part number of the araliphatic polyisocyanate compound was changed to 130 parts and the blending part number of the aromatic polyisocyanate compound was changed to 70 parts to obtain a reversible thermosensitive recording material. The blending ratio (mass ratio of non-volatile content) of the araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 65/35.

Test 1 (background density = background whiteness)
The density of the reversible thermosensitive recording layer surface of the reversible thermosensitive recording materials obtained in Examples 1 to 20 and Comparative Examples 1 to 9 was measured using a densitometer Macbeth RD918. The results are shown in Table 1. If the background density is 0.100 or less, the background whiteness is high and good, and if it is 0.150 or less, there is no practical problem.

Test 2 (color density = thermal response)
For the reversible thermosensitive recording materials obtained in Examples 1 to 20 and Comparative Examples 1 to 9, one sheet made of a transparent polyvinyl chloride resin having a thickness of 100 μm and a white polycrystal having a thickness of 200 μm are formed on the adhesive layer side on the support. Two sheets of vinyl chloride resin were overlapped in this order, sandwiched between two stainless steel mirror plates, and thermocompression bonded at 130 ° C. and a pressure of 1.5 MPa for 20 minutes to complete a reversible thermosensitive recording material laminate. . The laminate thus obtained was finished to a card size using a punching machine. This laminate is stored for 24 hours in an environment of 23 ° C. and 50% RH and 35 ° C. and 80% RH. Under each environment, a standard card reader / writer (model name: KU-R28111L) manufactured by Panasonic Communications Co., Ltd. is used. Printing was performed under the conditions, and the density of the obtained color image was measured in the same manner as in Test 1. The results are shown in Table 1. If the color density is 1.00 or higher, it is good, and if it is 0.70 or higher, there is no practical problem.

Test 3 (image erasability)
The card-size reversible thermosensitive recording material laminate produced in Test 2 is stored in a 35 ° C. 80% RH environment for 24 hours, and then the card reader / writer manufactured by Panasonic Communications Co., Ltd. (model name: KU- R28111L) was used for printing and erasing under standard conditions, and the density of the erased part was measured in the same manner as in Test 1. The results are shown in Table 1. If the erased portion concentration is 0.100 or less, it is good, and if it is 0.150 or less, it is at a level that causes no practical problem. Further, it is preferable that the difference between the erased portion density and the background density measured in Test 1 is small. The difference value is 0.010 or less, and the difference is 0.020 or less. It is.

Test 4 (erasing fogging)
For the reversible thermosensitive recording material laminate printed and erased in Test 3, the density of the unprinted portion in contact with the erase bar was measured in the same manner as in Test 1. The results are shown in Table 1. If the background density after erasure is 0.100 or less, it is good, and if it is 0.150 or less, it is at a level that causes no practical problems. Further, it is preferable that the difference between the background density after erasure and the background density measured in Test 1 and the difference between the background density after erasure and the erased part density measured in Test 3 are smaller, and the difference values are respectively If it is 0.010 or less, it is satisfactory, and if it is 0.020 or less, it is a level that causes no practical problem.

Test 5 (Repeated durability)
The card-size reversible thermosensitive recording material laminate produced in Test 2 was stored in an environment of 23 ° C. and 50% RH for 24 hours. Under the same environment, printing was performed under standard conditions using a card reader / writer (model name: KU-R28111L) manufactured by Panasonic Communications Co., Ltd., and then erased 100 times at intervals of 2 minutes. The state of the printed portion at the 100th time was visually observed and judged according to the following criteria. The results are shown in Table 1.
(Double-circle): The printed part is not damaged at all, and a beautiful image is formed.
○: A clear image is formed, but the area around the thermal head is slightly visible.
Δ: Printed, but scratched.
X: The printed part is scratched and the scratched part is not printed.

  As is apparent from Examples 1 to 20, the thermosensitive recording layer contains at least a polyol compound, an araliphatic polyisocyanate compound, and a binder component formed by crosslinking of the aromatic polyisocyanate compound, and the araliphatic poly By setting the blending ratio of the isocyanate compound / aromatic polyisocyanate compound (mass ratio of non-volatile content) to 70/30 to 95/5, the background whiteness is high, the image erasability is good, and the erasing fogging at the time of erasing is performed. Therefore, it becomes possible to obtain a reversible thermosensitive recording material having a good color density when printed under high temperature and high humidity.

  From a comparison between Examples 1 and 4, Example 1 in which the aromatic polyisocyanate compound is a compound represented by the general formula 1 is excellent in whiteness of the background, erasability of images, erasure fog hardly occurs, and high temperature. It is excellent in color density when printed under high humidity, which is preferable. From comparison of Examples 1, 5, and 6, Examples 1 and 5 in which the araliphatic polyisocyanate compound is a compound represented by Formula 2 are preferable in terms of background whiteness, erasure fog suppression, and color developability. .

  From the comparison of Examples 1 and 7 to 9, Example 1 in which the OH value of the polyol compound is 500 mgKOH / g or more and 600 mgKOH / g or less is excellent in both the color density and the repeated durability characteristics in each environment. It is preferable. From comparison of Examples 1 and 10 to 12, the maximum absorbance at 400 to 700 nm of the absorption spectrum of the solution having the active ingredient ratio (mass ratio) of dye precursor / acetic acid / acetone as 2/6/92 as the dye precursor. Examples 1, 10, and 11 using a compound having an A of 1.5 or more are preferable because the color density in each environment increases. From the comparison of Examples 1, 13, and 14, it is also possible to improve the background whiteness, the erasability of the image, and to suppress the erasing fog by using the erasing accelerator together.

  On the other hand, in Comparative Example 1 in which the blending ratio of araliphatic polyisocyanate compound / aromatic polyisocyanate compound is 98/2, color developability is poor when printing is performed under high temperature and high humidity. Comparative Examples 2 and 9 in which the blending ratio of the aromatic aliphatic polyisocyanate compound / aromatic polyisocyanate compound is 65/35, and Comparative Example 3 using only the aromatic polyisocyanate compound are background whiteness, image erasability, Erasure fog is inferior. In particular, Comparative Example 9 using a highly color-forming dye precursor having a maximum absorbance of 2.7 compared to Comparative Example 2 using a dye precursor having a maximum absorbance of 2.0, The erasing fogging is getting worse. Comparative Example 4 using only aliphatic polyisocyanate compound, Comparative Example 5 using alicyclic aliphatic polyisocyanate compound / aromatic polyisocyanate compound, Comparative Example 6 using aliphatic polyisocyanate compound / aromatic polyisocyanate compound together No. 7 is inferior in color density and repeated durability when printed under high temperature and high humidity. The comparative example 8 which used together the araliphatic polyisocyanate compound / aliphatic polyisocyanate compound is inferior to the color developability at the time of printing under high temperature and high humidity.

Claims (5)

  A heat-sensitive material comprising at least one surface of a support, usually a colorless or light dye precursor, and a reversible developer that causes a reversible color change in the dye precursor due to a difference in cooling rate after heating. In a reversible thermosensitive recording material provided with a recording layer, the thermosensitive recording layer contains at least a polyol compound, an araliphatic polyisocyanate compound and an aromatic polyisocyanate compound, and a binder component formed by crosslinking. A reversible thermosensitive recording material, wherein the blending ratio of polyisocyanate compound / aromatic polyisocyanate compound (mass ratio of nonvolatile content) is 70/30 to 95/5. The reversible thermosensitive recording material according to claim 1, wherein the aromatic polyisocyanate compound is a compound represented by the following general formula 1.

(In General Formula 1, R ¹ represents a methyl group or an ethyl group. The position of the methyl group bonded to each benzene ring is one of the 2, 4, 5, and 6 positions, and the location is not limited. ) The reversible thermosensitive recording material according to claim 1, wherein the araliphatic polyisocyanate compound is a compound represented by the following general formula 2.

(In General Formula 2, R ² represents a methyl group or an ethyl group.)   The reversible thermosensitive recording material according to claim 1, wherein the polyol compound has an OH value of 500 mgKOH / g or more and 600 mgKOH / g or less.   The dye precursor is a compound having a maximum absorbance at 400 to 700 nm of 1.5 or more of an absorption spectrum of a solution in which an active ingredient ratio (mass ratio) of dye precursor / acetic acid / acetone is 2/6/92. Item 10. A reversible thermosensitive recording material according to Item 1.