JP2005263736A - Method for producing reversibly thermal recording developer and electron-accepting compound, and reversibly thermal recording medium and reversibly thermal recording member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple method for efficiently producing an electron-accepting compound in a short time, affording a phenolic developer in high yield with few production steps, particularly through cutting a refining step using a large amount of an organic solvent or the like. <P>SOLUTION: The method for producing the electron-accepting compound comprises the step of synthesizing a phenolic compound of the structural formula(1)( wherein, m is an integer of 2-11; and n is an integer of 6-21 ) by reacting a long-chain alkyl isocyanate compound and an aminoalkylcarboxylic acid compound with a condensation agent, an activator and an aminophenol in succession in the identical solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention utilizes a color reaction between an electron-donating color-forming compound and an electron-accepting compound, and can control the formation of a color image by controlling thermal energy. The present invention relates to a reversible thermosensitive recording developer and a method for producing an electron-accepting compound, a reversible thermosensitive recording medium, and a reversible thermosensitive recording member.

  Conventionally, between an electron donating color developing compound (hereinafter also referred to as “color former” or “leuco dye”) and an electron accepting compound (hereinafter also referred to as “developer”). The heat-sensitive recording medium using the color development reaction is widely known, and is used in printers such as facsimiles, word processors, and scientific measuring instruments. However, any of these conventional thermal recording media in practical use has an irreversible color development and cannot be used repeatedly after erasing an image once recorded.

  On the other hand, various reversible recording media capable of reversibly developing and erasing colors have been proposed. For example, those using a combination of gallic acid and phloroglucinol as a developer (see Patent Document 1), those using a compound such as phenolphthalein or thymolphthalein as a developer (see Patent Document 2), color development Containing a homogeneous solution of an agent, a developer and a carboxylic acid ester in the heat-sensitive layer (see Patent Document 3, Patent Document 4 and Patent Document 5), and using an ascorbic acid derivative as the developer (see Patent Document 6) ), A developer using a salt of bis (hydroxyphenyl) acetic acid or gallic acid and a higher aliphatic amine as a developer (see Patent Document 7 and Patent Document 8).

  Further, by using an organic phosphate compound, an aliphatic carboxylic acid compound or a phenol compound having a long-chain aliphatic hydrocarbon group as a developer and combining the developer with a leuco dye as a color developer, color development and extinction are achieved. A reversible thermosensitive coloring composition that makes it easy to change the color under heating and cooling conditions, can maintain its coloring and decoloring states stably at room temperature, and can repeat coloring and decoloring. And a reversible thermosensitive recording medium using the same have been proposed (see Patent Document 9). Moreover, what has a specific structure is proposed about the phenolic compound which has a long-chain aliphatic hydrocarbon group as a developing agent (refer patent document 10).

  Among these, in particular, a reversible thermosensitive recording using a compound having a phenol skeleton and a long-chain alkyl group represented by the following structural formula (1) as a developer, and an amide group and a urea group as hydrogen bonding association groups. It is known that the medium has a high color density, is excellent in high-speed erasability and image storage, and has high practicality.

However, in said structural formula (1), m represents the integer of 2-11 and n represents the integer of 6-21.

A conventional method for producing a phenol developer having an amide group and a urea group is described in Patent Document 11 and is a synthesis method comprising two steps as shown in the following reaction formula.
First, as the first step, after condensing a long-chain alkyl isocyanate and an aminoalkyl carboxylic acid, the product is taken out from the reaction solution and purified to synthesize an intermediate of alkyl-urea-alkylene-carboxylic acid.
Next, as the second step, the intermediate obtained in the first step is reacted with an aminophenol together with an activator and a condensing agent, and then taken out from the reaction solution and purified. A phenol compound represented by the formula can be synthesized.

In the above reaction formula, MEK represents methyl ethyl ketone, THF represents tetrahydrofuran, HOBt represents 1-hydroxybenzotriazole, and DIPC represents N, N′-diisopropylcarbodiimide. m represents an integer of 2 to 11, and n represents an integer of 6 to 21.

  Although the phenol-based developer obtained by the synthesis method as described above can obtain the excellent characteristics as described above, the production process takes a long time, and in particular, there are many purification processes. There is a problem that a large amount of organic solvent is used, and the current situation is that improvement is desired.

Japanese Patent Laid-Open No. 60-193691 Japanese Patent Laid-Open No. Sho 61-237684 JP-A-62-138556 JP-A-62-138568 JP-A-62-140881 Japanese Patent Laid-Open No. 63-173684 JP-A-2-188293 JP-A-2-188294 JP-A-5-124360 Japanese Patent Laid-Open No. 6-210954 JP-A-10-67726

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, the present invention provides an electron-accepting compound that can be synthesized in a high yield with a small number of production processes, and that can produce an electron-accepting compound efficiently in a short time by reducing the number of purification processes that use a large amount of organic solvent. It is an object to provide a production method, a reversible thermosensitive recording medium and a reversible thermosensitive recording member using the electron-accepting compound.

Means for solving the problems are as follows.
<1> A synthesis step of synthesizing a phenol compound represented by the following structural formula (1) by sequentially reacting a long-chain alkyl isocyanate compound and an aminoalkylcarboxylic acid compound with a condensing agent, an activator, and aminophenol in the same solvent. It is a manufacturing method of the electron-accepting compound characterized by including.
However, in said structural formula (1), m represents the integer of 2-11 and n represents the integer of 6-21.
<2> The method for producing an electron-accepting compound according to <1>, wherein the condensing agent is any one of N, N′-dicyclohexylcarbodiimide and N, N′-diisopropylcarbodiimide.
<3> The method for producing an electron-accepting compound according to any one of <1> to <2>, wherein the activator is 1-hydroxybenzotriazole.
<4> The method for producing an electron-accepting compound according to any one of <1> to <3>, wherein the solvent is N, N′-dimethylformamide (DMF).
<5> The method for producing an electron-accepting compound according to any one of <1> to <4>, wherein the reaction temperature is 40 to 90 ° C.
<6> Mixed mass ratio of long-chain alkyl isocyanate compound, aminoalkyl carboxylic acid compound, condensing agent, activator, and aminophenol (long-chain alkyl isocyanate compound: aminoalkyl carboxylic acid compound: condensing agent: activator: amino Any one of <1> to <5>, wherein (phenol) is 1: 1.0 to 1.1: 0.8 to 1.2: 0.2 to 1.2: 1.0 to 1.5 The method for producing an electron-accepting compound described in 1.
In the method for producing an electron-accepting compound of the present invention according to any one of <1> to <6>, a phenol developer is obtained in a high yield with a small number of production steps, and particularly a large amount of an organic solvent. By reducing the number of purification steps using the above, an electron-accepting compound can be easily produced in a short time.

<7> The method for producing an electron-accepting compound according to any one of <1> to <6>, wherein the yield of the electron-accepting compound is 90% or more.
<8> A reversible color developer for heat-sensitive recording, comprising the electron-accepting compound produced by the method for producing an electron-accepting compound according to any one of <1> to <7>.
<9> A support and at least a heat-sensitive layer whose color tone reversibly changes depending on temperature on the support, and the heat-sensitive layer has a reversible thermosensitive recording developer according to claim 8 and A reversible thermosensitive recording medium comprising an electron donating color-forming compound.
<10> The reversible thermosensitive recording medium according to <9>, wherein the reversible thermosensitive recording medium is processed into a card shape, a label shape, or a sheet shape.

<11> A reversible thermosensitive recording comprising an information storage unit and a reversible display unit, wherein the reversible display unit includes the reversible thermosensitive recording medium according to any one of <9> to <10>. It is a member.
<12> The reversible thermosensitive recording member according to <11>, wherein the information recording unit is selected from a magnetic thermosensitive layer, a magnetic stripe, an IC memory, an optical memory, an RF-ID tag card, a disk, a disk cartridge, and a tape cassette. is there.
The thermoreversible recording member of the present invention has an information storage unit and a reversible display unit, and the reversible display unit is the thermoreversible recording medium of the present invention. In the thermoreversible recording member, in the reversible display portion, the thermosensitive layer contains the reversible thermosensitive recording developer of the present invention and an electron donating color developing compound. As a result, an image excellent in contrast, visibility and the like is formed. On the other hand, in the information recording unit, character information, image information, music, etc. are recorded by a recording method according to the type of magnetic thermosensitive layer, magnetic stripe, IC memory, optical memory, RF-ID tag card, disk, disk cartridge, tape cassette, etc. Desired information such as information and video information is recorded and erased.

  According to the present invention, various problems in the prior art can be solved, and a phenol-based developer can be obtained in a high yield by a small number of manufacturing processes, and in particular, by reducing the purification process using a large amount of organic solvent, etc. A reversible thermosensitive recording developer can be produced efficiently in a short time.

(Method for producing electron-accepting compound and developer for reversible thermosensitive recording)
The method for producing an electron-accepting compound of the present invention is represented by the following structural formula (1) by sequentially reacting a long-chain alkyl isocyanate compound and an aminoalkylcarboxylic acid compound with a condensing agent, an activator and an aminophenol in the same solvent. A synthesis step of synthesizing the phenol compound to be synthesized, and further comprising other steps as necessary.

However, in said structural formula (1), m represents the integer of 2-11 and n represents the integer of 6-21.
The reversible thermosensitive recording developer of the present invention is produced by the method for producing an electron-accepting compound of the present invention.
Hereinafter, the details of the reversible thermosensitive recording developer of the present invention will be clarified through the description of the method for producing the electron-accepting compound of the present invention.

  The method for producing an electron-accepting compound of the present invention is a one-step continuous synthesis in which a long-chain alkyl isocyanate compound and an aminoalkylcarboxylic acid compound are reacted with a condensing agent, an activator and an aminophenol in a solvent. The refining process using a large amount of an organic solvent or the like can be reduced by a fewer production process than the method, and a reversible thermosensitive recording developer can be produced in a high yield efficiently in a short time.

The long-chain alkyl isocyanate is not particularly limited and may be appropriately selected depending on the intended purpose.For example, octyl isocyanate, nonyl isocyanate, decyl isocyanate, undecyl isocyanate, dodecyl isocyanate, tridecyl isocyanate, tetradecyl isocyanate, Examples include pentadecyl isocyanate, hexadecyl isocyanate, and octadecyl isocyanate.
The chain length of the carbon chain in the long-chain alkyl isocyanate is different depending on the structure of the developer used in combination, and cannot be defined unconditionally, but is preferably 6 to 22, for example.

The aminoalkyl carboxylic acid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include β-alanine, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminocaproic acid, and ω-aminocapryl. Acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, and the like.
The chain length of the carbon chain in the aminoalkyl carboxylic acid varies depending on the structure of the developer used in combination and cannot be defined unconditionally, but is preferably 2 to 11, for example.

The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include ethyl acetate, dichloromethane, tetrahydrofuran (THF), N, N′-dimethylformamide (DMF), and the like. Among these, N, N′-dimethylformamide (DMF) is particularly preferably used.
The condensing agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, N, N′-dicyclohexylcarbodiimide (DCC), N, N′-diisopropylcarbodiimide (DIPC), N-ethyl- N′-3-dimethylaminopropylcarbodiimide, or a hydrochloride thereof, benzotriazol-1-yl-tris (dimethylamino) phosphonium hexafluorophosphide salt, diphenylphosphoryl azide, and the like. Among these, N, N '-Dicyclohexylcarbodiimide (DCC) and N, N'-diisopropylcarbodiimide (DIPC) are preferably used.
The activator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 1-hydroxybenzotriazole (HOBt), N-hydroxysuccinimide, 3-hydroxy-4-oxo-3,4 -Dihydro-1,2,3-benzotriazine, etc. are mentioned, and among these, 1-hydroxybenzotriazole (HOBt) is preferably used.
As said aminophenol, P-aminophenol is preferable, for example.

  Mixed mass ratio of the long-chain alkyl isocyanate compound, aminoalkyl carboxylic acid compound, condensing agent, activator, and aminophenol (long-chain alkyl isocyanate compound: aminoalkyl carboxylic acid compound: condensing agent: activator: aminophenol) Is preferably 1: 1.0 to 1.1: 0.8 to 1.2: 0.2 to 1.2: 1.0 to 1.5.

  The reaction temperature is preferably 40 to 90 ° C, more preferably 60 to 90 ° C. When the reaction temperature is less than 40 ° C., the progress of the condensation reaction may be delayed, and when it exceeds 90 ° C., there may be a problem such as danger when the raw materials are charged.

Here, for example, the electron-accepting compound represented by the structural formula (1) can be synthesized as follows, for example. First, as shown in the following reaction formula, 10.0 g of ε-aminocaproic acid and 900 ml of N, N′-dimethylformamide (DMF) (dried) were charged in a reaction vessel in a nitrogen stream, and 22.53 g of octadecyl isocyanate was added dropwise. did. Next, after stirring and reacting at 90 ° C. for 3 hours, 10.3 g of 1-hydroxybenztriazole and 9.62 g of diisopropylcarbodiimide were added, and the mixture was heated and stirred for 30 minutes. Thereafter, 8.32 g of p-aminophenol was added, and the mixture was heated and stirred at 80 ° C. for 3 hours.
After cooling to room temperature, the crystals are collected by filtration and washed with methanol to synthesize the desired N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide. it can.

In the reaction formula, HOBt represents 1-hydroxybenzotriazole, and DIPC represents N, N′-diisopropylcarbodiimide.

  The reversible thermosensitive recording developer produced by the method for producing an electron-accepting compound of the present invention can efficiently produce a phenol developer in a high yield (90% or more) by a small production process. It can be particularly suitably used as a developer for a reversible thermosensitive recording medium.

(Reversible thermosensitive recording medium)
The reversible thermosensitive recording medium of the present invention has at least a support and a thermosensitive layer whose color tone reversibly changes depending on temperature on the support, and the thermosensitive layer is the reversible thermosensitive recording of the present invention. A developer and an electron-donating color-forming compound (color-developing agent), and, if necessary, other components.

  The reversible thermosensitive recording medium can form a relatively colored state and a decolored state depending on the heating temperature and / or the cooling rate after heating. The basic coloring / decoloring phenomenon of the composition comprising the color former and developer used in the present invention will be described.

  FIG. 1 shows the relationship between the color density and temperature of this recording medium. When the temperature of the recording medium initially in the decolored state (A) is raised, color development occurs at a temperature T1 at which melting starts, and the leuco dye and the developer become a molten color state (B). When rapidly cooled from the melt color state (B), the color state can be lowered to room temperature and a solid color state (C) is obtained. Whether or not this color development state is obtained depends on the rate of temperature decrease from the molten state, and in slow cooling, the color disappears during the temperature decrease, and the same color disappearance state (A) or rapid color development state (C ) A relatively low concentration state is formed. On the other hand, when the temperature of the rapid color development state (C) is raised again, decoloration occurs at a temperature T2 lower than the color development temperature (D to E), and when the temperature is lowered from here, the same color disappearance state (A) is restored. The actual color developing temperature and color erasing temperature vary depending on the combination of the developer and color former used, and can be selected according to the purpose. Further, the density of the melt coloring state and the coloring density when rapidly cooled are not necessarily the same and may be different.

  In this reversible thermosensitive recording medium, the colored state (C) obtained by quenching from the molten state is a state in which the developer and the color former are mixed in a state where they can be contacted with each other, and this is a solid state. Often formed. This state is a state where the developer and the color former are aggregated to maintain the color development, and it is considered that the color development is stabilized by the formation of this aggregated structure. On the other hand, the decolored state is a state in which both phases are separated. This state is a state in which molecules of at least one compound aggregate to form a domain or crystallize, and the color former and developer are separated and stabilized by aggregation or crystallization. It is done. In many cases, in the present invention, more complete color erasure occurs due to phase separation of the two and crystallization of the developer. In both the decolorization by slow cooling from the melted state shown in FIG. 1 and the decoloration by heating from the colored state, the aggregation structure changes at this temperature, and phase separation and crystallization of the developer occur.

  The color image can be formed by heating to a temperature at which it is once melt-mixed by a thermal head or the like and then rapidly cooling. Further, decolorization is two methods, a method of slowly cooling from a heated state and a method of heating to a temperature slightly lower than the coloring temperature. However, they are the same in the sense that they are phase-separated or at least temporarily held at a temperature at which one crystallizes. The reason for rapid cooling in the formation of the colored state is to prevent the temperature from being maintained at this phase separation temperature or crystallization temperature. The rapid cooling and slow cooling here are relative to one composition, and the boundary thereof changes depending on the combination of the color former and the developer.

  As described above, the thermosensitive layer can be erased by controlling at least one of the heating temperature and the cooling rate after heating. Printing with this heat sensitive layer provides high image quality with high contrast.

-Electron donating color compound-
Conventionally known leuco dyes are used as the electron donating coloring compound (color former).

  As the leuco dye, a fluorane compound and an azaphthalide compound are suitable. For example, 2-anilino-3-methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-di (n-butylamino) fluorane 2-anilino-3-methyl-6- (Nn-propyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (N-isopropyl-N-methylamino) fluorane, 2-anilino -3-methyl-6- (N-isobutyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (Nn-amyl-N-methylamino) fluorane, 2-anilino-3-methyl -6- (N-sec-butyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (Nn-amyl-N-ethylamino) Luolan, 2-anilino-3-methyl-6- (N-iso-amyl-N-ethylamino) fluorane, 2-anilino-3-methyl-6- (Nn-propyl-N-isopropylamino) fluorane, 2-anilino-3-methyl-6- (N-cyclohexyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (N-ethyl-p-toluidino) fluorane, 2-anilino-3-methyl -6- (N-methyl-p-toluidino) fluorane, 2- (m-trichloromethylanilino) -3-methyl-6-diethylaminofluorane, 2- (m-trifluoromethylanilino) -3-methyl -6-diethylaminofluorane, 2- (m-trichloromethylanilino) -3-methyl-6- (N-cyclohexyl-N-methylamino) fluor Lan, 2- (2,4-dimethylanilino) -3-methyl-6-diethylaminofluorane, 2- (N-ethyl-p-toluidino) -3-methyl-6- (N-ethylanilino) fluorane, 2 -(N-ethyl-p-toluidino) -3-methyl-6- (N-propyl-p-toluidino) fluorane, 2-anilino-6- (Nn-hexyl-N-ethylamino) fluorane, 2- (O-chloroanilino) -6-diethylaminofluorane, 2- (o-chloroanilino) -6-dibutylaminofluorane, 2- (m-trifluoromethylanilino) -6-diethylaminofluorane, 2,3-dimethyl -6-dimethylaminofluorane, 3-methyl-6- (N-ethyl-p-toluidino) fluorane, 2-chloro-6-diethylaminofluorane, 2 -Bromo-6-diethylaminofluorane, 2-chloro-6-dipropylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 3-bromo-6-cyclohexylaminofluorane, 2-chloro-6- ( N-ethyl-N-isoamylamino) fluorane, 2-chloro-3-methyl-6-diethylaminofluorane, 2-anilino-3-chloro-6-diethylaminofluorane, 2- (o-chloroanilino) -3-chloro -6-cyclohexylaminofluorane, 2- (m-trifluoromethylanilino) -3-chloro-6-diethylaminofluorane, 2- (2,3-dichloroanilino) -3-chloro-6-diethylaminofluor Oran, 1,2-benzo-6-diethylaminofluorane, 3-diethylamino-6- (m-tri (Loromethylanilino) fluorane, 3- (1-ethyl-2-methylindol-3-yl) -3- (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl-2-) Methylindol-3-yl) -3- (2-ethoxy-4-diethylaminophenyl) -7-azaphthalide, 3- (1-octyl-2-methylindol-3-yl) -3- (2-ethoxy-4) -Diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl-2-methylindol-3-yl) -3- (2-methyl-4-diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl- 2-Methylindol-3-yl) -3- (2-methyl-4-diethylaminophenyl) -7-azaphthalide, 3- (1-ethyl-2-methylindo) Ru-3-yl) -3- (4-diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl-2-methylindol-3-yl) -3- (4-Nn-amyl-N- Methylaminophenyl) -4-azaphthalide, 3- (1-methyl-2-methylindol-3-yl) -3- (2-hexyloxy-4-diethylaminophenyl) -4-azaphthalide, 3,3-bis ( 2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3,3-bis (2-ethoxy-4-diethylaminophenyl) -7-azaphthalide, and the like.

In addition to the fluorane compound and the azaphthalide compound, conventionally known leuco dyes can be used as the color former. For example, 2- (p-acetylanilino) -6- (Nn- Amyl-Nn-butylamino) fluorane, 2-benzylamino-6- (N-ethyl-p-toluidino) fluorane, 2-benzylamino-6- (N-methyl-2,4-dimethylanilino) fluorane 2-benzylamino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-benzylamino-6- (N-methyl-p-toluidino) fluorane, 2-benzylamino-6- (N -Ethyl-p-toluidino) fluorane, 2- (di-p-methylbenzylamino) -6- (N-ethyl-p-toluidino) fluorane, 2- (α-phenyl ether) Ruamino) -6- (N-ethyl-p-toluidino) fluorane, 2-methylamino-6- (N-methylanilino) fluorane, 2-methylamino-6- (N-ethylanilino) fluorane, 2-methylamino-6 -(N-propylanilino) fluorane, 2-ethylamino-6- (N-methyl-p-toluidino) fluorane, 2-methylamino-6- (N-methyl-2,4-dimethylanilino) fluorane, 2-ethylamino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-dimethylamino-6- (N-methylanilino) fluorane, 2-dimethylamino-6- (N-ethylanilino) fluorane, 2-diethylamino-6- (N-methyl-p-toluidino) fluorane, 2-diethylamino-6- (N-ethyl-p-to) Louisino) fluorane, 2-dipropylamino-6- (N-methylanilino) fluorane, 2-dipropylamino-6- (N-ethylanilino) fluorane, 2-amino-6- (N-methylanilino) fluorane, 2-amino -6- (N-ethylanilino) fluorane, 2-amino-6- (N-propylanilino) fluorane, 2-amino-6- (N-methyl-p-toluidino) fluorane, 2-amino-6- (N -Ethyl-p-toluidino) fluorane, 2-amino-6- (N-propyl-p-toluidino) fluorane, 2-amino-6- (N-methyl-p-ethylanilino) fluorane, 2-amino-6- ( N-ethyl-p-ethylanilino) fluorane, 2-amino-6- (N-propyl-p-ethylanilino) fluorane, 2-amino -6- (N-methyl-2,4-dimethylanilino) fluorane, 2-amino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-amino-6- (N-propyl- 2,4-dimethylanilino) fluorane, 2-amino-6- (N-methyl-p-chloroanilino) fluorane, 2-amino-6- (N-ethyl-p-chloroanilino) fluorane, 2-amino-6- (N-propyl-p-chloroanilino) fluorane, 1,2-benzo-6- (N-ethyl-N-isoamylamino) fluorane, 1,2-benzo-6-dibutylaminofluorane, 1,2-benzo- 6- (N-methyl-N-cyclohexylamino) fluorane, 1,2-benzo-6- (N-ethyl-N-toluidino) fluorane, and the like.
These may be used alone or mixed, and can be multicolored or full-colored by laminating layers that develop colors having different colors.

  In the reversible thermosensitive recording medium, the mixing ratio of the reversible thermosensitive recording developer of the present invention and the electron-donating color-forming compound (color former) varies depending on the combination of the compounds used, and is generally different. However, the developer is preferably in the range of 0.1 to 20 and more preferably in the range of 0.2 to 10 with respect to the color former 1 in terms of molar ratio. If the amount of the developer for reversible thermosensitive recording of the present invention is less or greater than this range, the density of the colored state is lowered and may not be practical.

-Support-
The support is not particularly limited in its shape, structure, size and the like, and can be appropriately selected according to the purpose. Examples of the shape include a flat plate shape, May be a single layer structure or a laminated structure, and the size can be appropriately selected according to the size of the reversible thermosensitive recording medium.

Examples of the material for the support include inorganic materials and organic materials. Examples of the inorganic material include glass, quartz, silicon, silicon oxide, aluminum oxide, SiO ₂ , metal, and the like. Examples of the organic material include paper, cellulose derivatives such as cellulose triacetate, synthetic paper, polyethylene terephthalate, polycarbonate, polystyrene, polymethyl methacrylate, and the like. These may be used individually by 1 type and may use 2 or more types together.

The support is preferably surface-modified by corona discharge treatment, oxidation reaction treatment (chromic acid, etc.), etching treatment, easy adhesion treatment, antistatic treatment, etc. for the purpose of improving the adhesion of the coating layer. . Moreover, it is preferable to add a white pigment such as titanium oxide to the support to make it white.
There is no restriction | limiting in particular as thickness of the said support body, According to the objective, it can select suitably, 50-2,000 micrometers is preferable and 100-1,000 micrometers is more preferable.

  The support may have a magnetic heat sensitive layer on at least one of the same surface and the opposite surface as the heat sensitive layer. The reversible thermosensitive recording medium of the present invention may be attached to another medium via an adhesive layer or the like. Alternatively, a back coat layer is provided on one side of a support such as a PET film, the release layer used for the thermal transfer ribbon on the opposite side of the back coat layer, the heat-sensitive layer of the present invention on the release layer, and paper on the surface, A resin layer that can be transferred to a resin film, a PET film, or the like may be provided and transferred using a thermal transfer printer.

  The heat-sensitive layer may be any material as long as the electron-accepting compound (developer) and the electron-donating color-forming compound (color former) are present. A state in which the color former and the compound of the present invention are finely and uniformly dispersed is used. The color former and the compound of the present invention may individually form particles, but more preferably form a dispersed state as composite particles. This can be achieved by once melting and dissolving the color former and the compound of the present invention. Such a heat-sensitive layer is formed by applying a solution obtained by dispersing and dissolving each material in a solvent, or mixing and dispersing or dissolving each material in a solvent on a support and drying. Is done by. The color former and the compound of the present invention can be used by encapsulating them in microcapsules.

  Examples of the binder resin used for forming the heat-sensitive layer include polyvinyl chloride, polyvinyl acetate, vinyl chloride vinyl acetate copolymer, ethyl cellulose, polystyrene, styrene copolymer, phenoxy resin, polyester, aromatic polyester, Examples include polyurethane, polycarbonate, polyacrylic acid ester, polymethacrylic acid ester, acrylic acid copolymer, maleic acid copolymer, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, and starches. The role of these binder resins is to keep the materials of the composition uniformly dispersed without being displaced by the application of heat for recording and erasing. Therefore, it is preferable to use a resin having high heat resistance as the binder resin, and it is particularly preferable to use a thermosetting resin.

  The curable resin is, for example, a combination of a crosslinking agent and a resin having an active group that reacts with the crosslinking agent, and is a resin that can be crosslinked and cured by heat, electron beam, ultraviolet rays, or the like. Resins used in thermosetting include, for example, resins having groups that react with a crosslinking agent such as hydroxyl groups and carboxyl groups, such as phenoxy resins, polyvinyl butyral resins, cellulose acetate propionate, and cellulose acetate butyrate, or hydroxyl groups and carboxyl groups. There are resins obtained by copolymerizing monomers with other monomers. Examples of the copolymer resin include vinyl chloride, acrylic, and styrene resins. Specifically, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-hydroxypropyl acrylate copolymer. And vinyl chloride-vinyl acetate-maleic anhydride copolymer.

Examples of the crosslinking agent for thermal crosslinking include isocyanates, amines, phenols, and epoxy compounds. Examples of the isocyanates include polyisocyanate compounds having a plurality of isocyanate groups. Specifically, hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), xylylene diisocyanate (XDI), and trimethylolpropane thereof. And adduct type, burette type, isocyanurate type and blocked isocyanates.
As for the addition amount with respect to the resin of the said crosslinking agent, ratio of the functional group of a crosslinking agent with respect to the number of the active groups contained in resin has 0.01-2.0. If it is less than this, the heat strength is insufficient, and if it is added more than this, the coloring / decoloring properties may be adversely affected.

  In the reversible thermosensitive recording medium, an additive for improving or controlling the coating characteristics and coloring / decoloring characteristics of the thermosensitive layer can be further used as necessary. Examples of these additives include dispersants, surfactants, conductive agents, fillers, lubricants, antioxidants, light stabilizers, ultraviolet absorbers, color stabilizers, decolorization accelerators, and the like. It is done.

  The reversible thermosensitive recording medium of the present invention is an intermediate layer, a protective layer, a back layer, an undercoat layer, a photothermal conversion layer, a colored layer, an air layer, a light, as appropriate, in addition to the thermosensitive layer. You may have other layers, such as a reflection layer, an adhesive layer, a protective layer, an adhesive bond layer, and an adhesion layer. Each of these layers may have a single layer structure or a laminated structure.

  The reversible thermosensitive recording medium of the present invention can be processed into a desired shape according to the application, for example, processed into a card shape, a sheet shape, a roll shape, or the like. As for the processed card, it can be applied to prepaid cards, point cards, and credit cards. If the sheet size is larger than the card size, the printing range is widened, so it can be used for general documents, process management instructions, and the like.

(Reversible thermosensitive recording material)
In the reversible thermosensitive recording member of the present invention, the thermosensitive layer capable of reversible display and the information storage unit are provided (integrated) on the same card, and a part of the stored information of the information storage unit is displayed on the thermosensitive layer. By doing so, the cardholder can check the information just by looking at the card without a special device, which is excellent in convenience. In addition, when the contents of the information storage unit are rewritten, the reversible thermosensitive recording medium can be repeatedly used by rewriting the display of the thermoreversible recording unit.

  There is no restriction | limiting in particular as said information storage part, According to the objective, it can select suitably, For example, a magnetic thermosensitive layer, a magnetic stripe, IC memory, an optical memory, RF-ID tag etc. are suitable. In particular, in a sheet medium having a size larger than the card size, an IC memory and an RF-ID tag are preferably used. The RF-ID tag includes an IC chip and an antenna connected to the IC chip.

  As the magnetic heat-sensitive layer, commonly used iron oxide, barium ferrite, etc. and vinyl chloride-based, urethane-based resin, nylon-based resin, etc. are used, and are formed on a support by a method such as vapor deposition / sputtering. It is formed without using a resin. The magnetic heat-sensitive layer may be provided on the surface of the support opposite to the heat-sensitive layer, or may be provided between the support and the heat-sensitive layer and on a part of the heat-sensitive layer. Further, a reversible thermosensitive material used for display may be used in the storage unit by a barcode, a two-dimensional code, or the like. Of these, magnetic recording and IC are more preferable.

  More specifically, it can be particularly suitably used for the following reversible thermosensitive recording label and reversible thermosensitive recording member of the present invention.

The reversible thermosensitive recording member of the present invention has the thermosensitive layer capable of reversible display and an information storage unit, and a suitable example of the information storage unit is an RF-ID tag. FIG. 2 shows a schematic diagram of the RF-ID tag 85. The RF-ID tag 85 includes an IC chip 81 and an antenna 82 connected to the IC chip. The IC chip 81 is divided into four parts: a storage unit, a power supply adjustment unit, a transmission unit, and a reception unit. In the communication, the RF-ID tag and the reader / writer antenna communicate with each other by radio waves to exchange data. Specifically, an RF-ID antenna receives a radio wave from a reader / writer, and an electromotive force is generated by electromagnetic induction or the like by a resonance action. This activates the IC chip in the RF-ID tag, converts the information in the chip into a signal, and then transmits a signal from the RF-ID tag. This information is received by the antenna on the reader / writer side and recognized by the data processing device, and data processing is performed on the software side.
The RF-ID tag is processed into a label or a card, and the RF-ID tag 85 can be attached to the reversible thermosensitive recording medium of the present invention as shown in FIG. The RF-ID tag 85 can be attached to the heat-sensitive layer surface or the back layer surface, but is preferably attached to the back layer surface. A known adhesive or pressure-sensitive adhesive can be used to bond the RF-ID tag and the reversible thermosensitive recording medium.

FIG. 4 shows an example in which the reversible thermosensitive recording medium is applied to an industrial rewritable sheet (reversible thermosensitive recording member) 90. As shown in FIG. 4A, a rewritable display section is provided on the thermosensitive layer side. An RF-ID tag may be attached to the back surface (back layer) as shown in FIG. 4B, or an RF-ID tag may be attached as shown in FIG. However, those having an RF-ID tag are preferable in terms of convenience.
FIG. 5 shows an example of how to use an industrial rewritable sheet in which the reversible thermosensitive recording medium (rewritable sheet) of the present invention is combined with an RF-ID tag. First, information such as an article name and quantity is recorded on a sheet and an RF-ID tag with respect to delivered raw materials, and attached to a returnable box or the like for inspection. In the next process, a processing instruction is given to the delivered raw material, information is recorded on the rewritable sheet and the RF-ID tag, and a processing instruction document is obtained, and the process proceeds to the processing process. Next, the processed product is attached with a rewritable sheet on which ordering information is recorded as an ordering instruction and an RF-ID tag. After the product is shipped, the rewritable sheet is collected, the shipping information is read, and used again as an invoice.

  The reversible thermosensitive recording label of the present invention comprises a surface opposite to the image-forming surface of the reversible thermosensitive recording medium of the present invention (if the thermosensitive layer is provided on a support, The surface opposite to the surface on which the heat-sensitive layer is formed has at least one of an adhesive layer and a pressure-sensitive adhesive layer, and further has other layers appropriately selected as necessary.

The shape, structure, size and the like of the adhesive layer to the pressure-sensitive adhesive layer are not particularly limited and can be appropriately selected according to the purpose. For example, the shape includes a sheet shape, a film shape, and the like. The structure may be a single-layer structure or a laminated structure, and the size may be larger or smaller than the heat-sensitive layer.
The material of the adhesive layer to the pressure-sensitive adhesive layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, urea resin, melamine resin, phenol resin, epoxy resin, vinyl acetate resin, acetic acid Vinyl-acrylic copolymer, ethylene-vinyl acetate copolymer, acrylic resin, polyvinyl ether resin, vinyl chloride-vinyl acetate copolymer, polystyrene resin, polyester resin, polyurethane resin, polyamide resin Chlorinated polyolefin resins, polyvinyl butyral resins, acrylic ester copolymers, methacrylic ester copolymers, natural rubber, cyanoacrylate resins, silicone resins, and the like. These may be used individually by 1 type, may use 2 or more types together, may be a hot-melt type, may use a release paper, and may be a non-release paper type.

When the reversible thermosensitive recording label has at least one of the adhesive layer and the pressure-sensitive adhesive layer, the entire surface of a thick substrate such as a card made of vinyl chloride with a magnetic stripe, which is difficult to apply the thermosensitive layer, or the like. A part of information stored in the magnetism can be displayed.
The reversible thermosensitive recording label can be used as a substitute for a display label on a disk cartridge containing a rewritable disk such as a flexible disk (FD), MD, or DVD-RAM.

FIG. 6 shows an example in which the reversible thermosensitive recording label 10 of the present invention is affixed onto an MD disk cartridge 70. In this case, it is possible to apply to uses such as automatically changing the display contents in accordance with the change of the contents stored in the MD. In the case of a disc that does not use a disc cartridge such as a CD-RW, the reversible thermosensitive recording label of the present invention may be directly attached to the disc.
FIG. 7 shows an example in which the reversible thermosensitive recording label 10 of the present invention is affixed on the CD-RW 71. In this case, the reversible thermosensitive recording label can be pasted on a write-once disc such as CR-R instead of CD-RW, and a part of the stored information added to the CD-R can be rewritten and displayed. It is.

  FIG. 8 shows an example in which the reversible thermosensitive recording label of the present invention is pasted on an optical information recording medium (CD-RW) using an AgInSbTe phase change memory material. The basic configuration of this CD-RW is that a first dielectric layer 110, an optical information storage layer 109, a second dielectric layer 108, a reflective heat dissipation layer 107, and an intermediate layer 106 are formed on a base 111 having a guide groove. The hard coat layer 112 is provided on the back surface of the substrate 111 in order. The reversible thermosensitive recording label 10 of the present invention is affixed on the CD-RW intermediate layer 106. The reversible thermosensitive recording label 10 includes an adhesive layer or an adhesive layer 105, a back layer 104, a support 103, a reversible thermosensitive layer 102, and a protective layer 101 in this order. The dielectric layer is not necessarily provided on both sides of the optical information storage layer, but the first dielectric layer 110 may be provided when the substrate is made of a material having low heat resistance such as polycarbonate resin. desirable.

  FIG. 9 shows an example in which the reversible thermosensitive recording label 10 of the present invention is stuck on the video cassette 72. In this case, the display content can be automatically changed in accordance with the change in the content stored in the video tape cassette.

  As a method of providing the reversible thermosensitive recording function on a card, a disk, a disk cartridge, and a tape cassette, in addition to a method of applying the reversible thermosensitive recording label, a method of directly applying the thermosensitive layer on them, Examples include a method in which the heat-sensitive layer is formed on another support in advance and the heat-sensitive layer is transferred onto the card, the disk, the disk cartridge, and the tape cassette. In the case of the method for transferring the heat-sensitive layer, the adhesive layer such as a hot-melt type or the pressure-sensitive adhesive layer may be provided on the heat-sensitive layer. When the reversible thermosensitive recording label is affixed on a rigid object such as the card, the disc, the disc cartridge, and the tape cassette, or when the thermosensitive layer is provided, the contact with the thermal head is improved. In order to form an image uniformly, it is preferable that a layer or sheet serving as a cushion is provided between a rigid substrate and a label or the heat-sensitive layer.

In the reversible thermosensitive recording medium of the present invention, for example, as shown in FIG. 10, a reversible thermosensitive layer 13, an intermediate layer 14, and a protective layer 15 are provided on a support 11, and a back layer is provided on the back surface of the support 11. 11, a film in which a reversible thermosensitive layer 13 and a protective layer 15 are provided on a support 11, and a back layer 16 is provided on the back surface of the support 11, as shown in FIG. Embodiments can be taken.
The film (reversible thermosensitive recording medium) of each aspect can be suitably used for, for example, various sheet-like industrial rewritable sheets provided with the RF-ID tag 85 shown in FIG. Further, for example, as shown in FIG. 12A, it can be used as a form processed into a reversible thermosensitive recording card 21 having a print display unit 23. As shown in FIG. 12B, a magnetic recording portion is formed on the back side of the card, and a back layer 24 is formed on the magnetic recording portion.

  In addition, the reversible thermosensitive recording member (card) shown in FIG. 13A is formed on the support by processing a film provided with a thermosensitive layer and a protective layer into a card shape to form a depression 25 for accommodating an IC chip, It is processed into a card shape. In FIG. 13A, the rewrite recording unit 26 is labeled on a card-like reversible thermosensitive recording medium, and an IC chip embedding recess 25 is formed at a predetermined position on the back side of the cart. As shown in FIG. 13B, the wafer 231 is assembled and fixed in the recess 25. In the wafer 231, an integrated circuit 233 is provided on a wafer substrate 232, and a plurality of contact terminals 234 that are electrically connected to the integrated circuit 233 are provided on the wafer substrate 232. The contact terminal 234 is exposed on the back side of the wafer substrate 232 and is configured such that a dedicated printer (reader / writer) can electrically contact the contact terminal 234 to read or rewrite predetermined information. Yes.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Example 1)
Synthesis of N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide
As shown in the following reaction formula, 10.0 g of ε-aminocaproic acid and 900 ml of N, N′-dimethylformamide (DMF) (dry) were charged in a reaction vessel in a nitrogen stream, and 22.53 g of octadecyl isocyanate was added dropwise. Next, after stirring and reacting at 90 ° C. for 3 hours, 10.3 g of 1-hydroxybenztriazole and 9.62 g of diisopropylcarbodiimide were added, and the mixture was heated and stirred for 30 minutes. Thereafter, 8.32 g of p-aminophenol was added, and the mixture was heated and stirred at 80 ° C. for 3 hours. After cooling to room temperature, the crystals were collected by filtration and washed with methanol to synthesize the target compound.

In the reaction formula, HOBt represents 1-hydroxybenzotriazole, and DIPC represents N, N′-diisopropylcarbodiimide.

  Table 1 shows the yield, melting point, and elemental analysis results for the obtained compound. In addition, FIG. 14 shows an infrared absorption spectrum measured with a Fourier transform infrared spectrophotometer FT-720 (manufactured by Horiba, Ltd.). From these results, it was confirmed that the target product was N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide.

(Example 2)
Synthesis of N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide
In Example 1, except that the reaction temperature and time of ε-aminocaproic acid and octadecyl isocyanate were 2 hours at 80 ° C., and the reaction temperature and time after addition of aminophenol were 2 hours at 70 ° C. The target compound was synthesized in the same manner as described above.
The obtained target product N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide had a melting point of 182 ° C. and a yield of 91.5%.

(Example 3)
Synthesis of N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide
In Example 1, except that dicyclohexylcarbodiimide was used instead of diisopropylcarbodiimide, the compound of interest was synthesized in the same manner as in Example 1.
The obtained target product N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide had a melting point of 181 ° C. and a yield of 91.3%.

Example 4
Synthesis of N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide
The compound of interest was synthesized in the same manner as in Example 1 except that the octadecyl isocyanate was changed to 23.66 g and the p-aminophenol was changed to 8.73 g.
The obtained target product N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide had a melting point of 182 ° C. and a yield of 93.1%.

(Comparative Example 1)
Synthesis of N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide
As shown in the following reaction formula, 18.4 g of ε-aminocaproic acid sodium salt, 35.5 g of octadecyl isocyanate, and 900 ml of 2-butanone were charged in a reaction vessel and stirred for 6 hours under reflux. Next, the precipitated crystals were separated by filtration, washed with water, poured into an acetic acid aqueous solution, stirred for 3 hours, and then filtered off again. The obtained crystals were washed with water, dried and recrystallized from toluene. The obtained crystals were suspended in 1200 ml of tetrahydrofuran and heated to 65 ° C. While stirring the suspension, 16.2 g of 1-hydroxybenztriazole, 15.1 g of diisopropylcarbodiimide, and 13.1 g of p-aminophenol were added and reacted under reflux for 2 hours. After completion of the reaction, the reaction solution was cooled to room temperature, filtered off, washed with water, and recrystallized from ethanol to synthesize the desired product.

In the above reaction formula, MEK represents methyl ethyl ketone, THF represents tetrahydrofuran, HOBt represents 1-hydroxybenzotriazole, and DIPC represents N, N′-diisopropylcarbodiimide.

  Table 2 shows the yield, melting point, and elemental analysis results for the obtained compound. Further, FIG. 15 shows an infrared absorption spectrum measured with a Fourier transform infrared spectrophotometer FT-720 (manufactured by Horiba, Ltd.). From these results, it was confirmed that the target product was N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide.

As apparent from the above results, according to the production method of the present invention, a phenol developer useful for a reversible thermosensitive recording medium can be efficiently produced with a small production process and a high yield.
(Example 5)
-Production of reversible thermosensitive recording medium-
(1) Support As a support, a 188 μm thick cloudy polyester film (Teijin DuPont, Tetron film U2L98W) was used.
(2) Formation of thermosensitive layer N- (4-hydroxyphenyl) -6-[(Nn-octadecylcarbamoyl) amino] hexanamide 4 synthesized in Example 1 represented by the following structural formula as a developer A composition consisting of 9 parts by mass, 9 parts by mass of an acrylic polyol resin (manufactured by Mitsubishi Rayon Co., Ltd., LR503, solid content concentration 50% by mass) and 70 parts by mass of methyl ethyl ketone is pulverized using a ball mill until the particle size becomes 1 to 4 μm. Distributed.

To the obtained dispersion, 1 part by mass of 2-anilino-3-methyl-6-diethylaminofluorane and 2 parts by mass of an adduct type hexamethylene diisocyanate 75% by mass ethyl acetate solution (Nihon Polyurethane Co., Ltd., Colonnade HL) were added. The mixture was stirred well to prepare a heat-sensitive layer coating solution.
The obtained heat-sensitive layer coating solution was applied to the support using a wire bar, dried at 100 ° C. for 2 minutes, and then heated at 60 ° C. for 24 hours to form a heat-sensitive layer having a thickness of about 8.0 μm. Provided.

(3) Formation of the intermediate layer 100 parts by mass of a 10% by weight methyl ethyl ketone (MEK) solution of polyester polyol resin (Takeda Pharmaceutical Co., Ltd., Takelac U-21), zinc oxide fine particles (ZS-303, manufactured by Sumitomo Osaka Cement Co., Ltd.) ) 10 parts by mass and 15 parts by mass of Coronate HL (manufactured by Nippon Polyurethane Co., Ltd.) were mixed to prepare an intermediate layer coating solution.
The obtained intermediate layer coating solution was applied onto the heat sensitive layer using a wire bar, dried at 90 ° C. for 1 minute, and then heated at 60 ° C. for 2 hours to form an intermediate layer having a thickness of about 2.0 μm. Was provided.

(4) Formation of protective layer 10 parts by mass of urethane acrylate ultraviolet curable resin (C7-157, manufactured by Dainippon Ink Co., Ltd.), 1.5 parts by mass of silica (P-527, manufactured by Mizusawa Chemical Co., Ltd.), and acetic acid 90 parts by mass of ethyl was mixed to prepare a protective layer coating solution.
After coating the obtained protective layer coating solution on the intermediate layer using a wire bar, it is passed under an ultraviolet lamp with an irradiation energy of 80 W / cm at a conveying speed of 12 m / min and cured to protect the film to a thickness of 3 μm. A layer was provided.
Thus, a reversible thermosensitive recording medium of Example 5 was produced.

The obtained reversible thermosensitive recording medium of Example 5 was applied with an 8 dot / mm thermal head under conditions of an applied voltage of 13.3 V and an applied pulse width of 1.2 milliseconds. When the optical density of the printed part and the background part was measured using a Macbeth densitometer RD-914, the printed density was 1.16 and the background density was 0.10. Next, when erasing was performed at 150 ° C. for 0.5 seconds using a hot stamp, the erasing density was 0.10. Further, when the above-mentioned printing / erasing was repeated 50 times, the printing density was hardly lowered and the erasing density was hardly raised, and there was no dent. Further, when the print sample was irradiated with a fluorescent lamp 5500 lux for 100 hours, discoloration and unerased residue at the time of erasing were not recognized in both the printed portion and the background portion, and the state was good.
From the above results, the reversible thermosensitive recording medium of the present invention was evaluated to have good characteristics when evaluated for color density, decoloration density, and image area storage stability.

According to the method for producing an electron-accepting compound of the present invention, it is possible to provide a phenol-based electron-accepting compound (developer) that has a small number of steps and a high yield and is useful for producing a reversible thermosensitive recording medium.
The electron-accepting compound of the present invention is used as a developer, and is suitably used for producing a reversible thermosensitive recording medium in combination with a color former.
The reversible thermosensitive recording medium of the present invention can reversibly develop and decolor, has a high color density, and is excellent in high-speed erasability, image storage, etc., prepaid card, point card, credit card, It can be used widely for recording labels, general documents and process control sheets.

FIG. 1 is a diagram showing the color development / decoloration characteristics (color development / decoloration phenomenon) of the reversible thermosensitive recording medium of the present invention. FIG. 2 is a schematic diagram illustrating an example of an RF-ID tag. FIG. 3 is a schematic view showing a state in which an RF-ID tag is bonded to the back layer surface side of the reversible thermosensitive recording medium. FIG. 4 is a schematic view showing an example of an industrial rewritable sheet (reversible thermosensitive recording medium). FIG. 5 is a schematic view showing a method of using an industrial rewritable sheet (reversible thermosensitive recording medium). FIG. 6 is a schematic view showing an example of a state in which the reversible thermosensitive recording medium label of the present invention is stuck on an MD disk cartridge. FIG. 7 is a schematic view showing an example of a state in which the reversible thermosensitive recording medium label of the present invention is stuck on a CD-RW. FIG. 8 is a schematic cross-sectional view showing an example of a state in which the reversible thermosensitive recording medium label of the present invention is stuck on an optical information recording medium (CD-RW). FIG. 9 is a schematic view showing an example of a state in which the reversible thermosensitive recording medium label of the present invention is attached to a video cassette. FIG. 10 is a schematic sectional view showing an example of the layer structure of the reversible thermosensitive recording medium of the present invention. FIG. 11 is a schematic sectional view showing another example of the layer structure of the reversible thermosensitive recording medium of the present invention. FIG. 12A is a schematic view of the surface side of an example of the reversible thermosensitive recording medium of the present invention processed into a card shape. FIG. 12B is a schematic diagram of the back side of FIG. 12A. FIG. 13A is a schematic view of an example in which an example of the reversible thermosensitive recording medium of the present invention is processed into another card shape. FIG. 13B is a schematic view of an IC chip embedded in the IC chip recess of FIG. 13A. 14 is a chart of an infrared absorption spectrum of the compound synthesized in Example 1. FIG. FIG. 15 is a chart of an infrared absorption spectrum of the compound synthesized in Comparative Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reversible thermosensitive recording medium 10 Reversible thermosensitive recording label 11 Support body 13 Heat sensitive layer 14 Intermediate layer 15 Protective layer 16 Back layer 22 Rewrite recording part 23 Print display part 24 Back layer 25 Recessed part 26 Rewrite recording part 70 MD disk cartridge 71 CD-RW
72 Video cassette 81 IC chip 82 Antenna 85 RF-ID tag 90 Industrial rewritable sheet (reversible thermosensitive recording member)
DESCRIPTION OF SYMBOLS 101 Protective layer 102 Heat sensitive layer 103 Support body 104 Back layer 105 Adhesive layer or adhesive layer 106 Intermediate layer 107 Reflection heat dissipation layer 108 Second dielectric layer 109 Optical information storage layer 110 First dielectric layer 111 Base body 112 Hard coat layer 231 Wafer 232 Wafer substrate 233 Integrated circuit 234 Contact terminal

Claims (12)

Including a synthesis step of sequentially reacting a long-chain alkyl isocyanate compound and an aminoalkylcarboxylic acid compound with a condensing agent, an activator, and an aminophenol in the same solvent to synthesize a phenol compound represented by the following structural formula (1). A method for producing an electron-accepting compound.
However, in said structural formula (1), m represents the integer of 2-11 and n represents the integer of 6-21.   The method for producing an electron-accepting compound according to claim 1, wherein the condensing agent is any one of N, N'-dicyclohexylcarbodiimide and N, N'-diisopropylcarbodiimide.   The method for producing an electron-accepting compound according to claim 1, wherein the activator is 1-hydroxybenzotriazole.   The method for producing an electron-accepting compound according to any one of claims 1 to 3, wherein the solvent is N, N'-dimethylformamide (DMF).   The method for producing an electron-accepting compound according to any one of claims 1 to 4, wherein the reaction temperature is 40 to 90 ° C.   Mixing mass ratio of long-chain alkyl isocyanate compound, aminoalkyl carboxylic acid compound, condensing agent, activator, and aminophenol (long-chain alkyl isocyanate compound: aminoalkyl carboxylic acid compound: condensing agent: activator: aminophenol) 1: 1.0 to 1.1: 0.8 to 1.2: 0.2 to 1.2: 1.0 to 1.5 Electron acceptability according to any one of claims 1 to 5 Compound production method.   The method for producing an electron-accepting compound according to any one of claims 1 to 6, wherein the yield of the electron-accepting compound is 90% or more.   A developer for reversible thermosensitive recording, comprising the electron-accepting compound produced by the method for producing an electron-accepting compound according to any one of claims 1 to 7.   9. A reversible thermosensitive recording developer and electron donating property according to claim 8, comprising at least a support and a thermosensitive layer whose color tone reversibly changes depending on temperature on the support. A reversible thermosensitive recording medium comprising a color developing compound.   The reversible thermosensitive recording medium according to claim 9, wherein the reversible thermosensitive recording medium is processed into a card shape, a label shape, or a sheet shape.   A reversible thermosensitive recording member comprising an information storage unit and a reversible display unit, wherein the reversible display unit includes the reversible thermosensitive recording medium according to claim 9. The reversible thermosensitive recording member according to claim 11, wherein the information recording unit is selected from a magnetic thermosensitive layer, a magnetic stripe, an IC memory, an optical memory, an RF-ID tag card, a disk, a disk cartridge, and a tape cassette.