JPH09254545A - Reversible thermal recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reversible thermal recording material utilizing the reaction of a color former such as a fluorane compd. and a coupler allowing the color former to generate a reversible hue change by heating, having good image contrast, capable of forming and erasing an image, reduced in damage even if repeatedly used in color development and color erasure and having high water resistance. SOLUTION: This reversible thermal recording material is constituted by providing a reversible thermal recording layer containing a usually colorless or light-colored electron donating dye precursor and a reversible coupler allowing the dye precursor to develop a color by heating and erasing the color by reheating the developed color dye precursor on at least the single surface of a support. In this case, a polyvinyl acetal resin is added to the reversible thermal recording layer. Further, the reversible thermal recording layer is crosslinked by isocyanate. As a solvent, a mixed solvent of water and alcohol is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reversible thermosensitive recording material capable of forming and erasing an image by heating. The reversible thermosensitive recording material is less damaged by repeated use of coloring and decoloring, and has strong water resistance. A heat recording material is provided.

[0002]

2. Description of the Related Art A thermosensitive recording material generally comprises a support having thereon a thermosensitive recording layer mainly composed of an electron-donating, usually colorless or pale-colored dye precursor and an electron-accepting developer. By heating with a thermal head, a hot pen, a laser beam, or the like, the dye precursor and the developer react instantaneously to obtain a recorded image. Japanese Patent Publication No. 43-4160, Japanese Patent Publication No. Sho 4
It is disclosed in JP-A-5-14039.

In general, such a heat-sensitive recording material cannot erase the portion of the image once formed and return to the state before the image is formed. Therefore, when further information is recorded, the image is not recorded. There was no choice but to add to the formation part. For this reason, when the area of the heat-sensitive recording portion is limited, there has been a problem that the recordable information is limited and all necessary information cannot be recorded.

In recent years, a reversible thermosensitive recording material has been devised which can be repeatedly used for image formation and image erasure in order to deal with such a problem. For example, JP-A-54-11937.
7, JP-A-63-39377, JP-A-63
No. 41186 discloses a heat-sensitive recording material composed of a resin base material and organic low-molecules dispersed in the resin base material. However, since this method reversibly changes the transparency of the heat-sensitive recording material by heat energy, the contrast between the image-formed area and the image-unformed area is insufficient.

Further, in the methods described in JP-A-50-81157 and JP-A-50-105555, since the image to be formed changes according to the ambient temperature, the image forming state and the erasing state. The holding temperatures are different, and these two states cannot be held for an arbitrary period at room temperature.

Further, in Japanese Patent Laid-Open No. 59-120492, the hysteresis characteristic of the color-developing component is utilized to keep the recording material in the hysteresis temperature range, thereby forming an image.
Although a method of maintaining the erased state is described, this method requires a heating source and a cooling source for image formation and erasure, and the temperature range in which the image formation state and the erased state can be maintained is limited to the hysteresis temperature region. However, it is still insufficient for use in the temperature environment of daily life.

On the other hand, JP-A-2-188293, JP-A-2-188294, and International Publication No. WO90 /
No. 11898 describes a reversible thermosensitive recording medium composed of a leuco dye and a color-developing and decoloring agent for coloring and decoloring the leuco dye by heating. The color-developing agent is an amphoteric compound having an acidic group for coloring the leuco dye and a basic group for decolorizing the colored leuco dye, and has a coloring effect by an acidic group or a decolorizing effect by a basic group by controlling thermal energy. One is preferentially generated to perform color development and decoloration. However, in this method, it is impossible to completely switch the color development reaction and the color removal reaction only by controlling the thermal energy, and since both reactions occur at a certain ratio at the same time, sufficient color development density cannot be obtained, and the color removal Can not be done completely. Therefore, sufficient image contrast cannot be obtained. Also,
Since the decoloring action of the basic group also acts on the color development part at room temperature,
The phenomenon that the density of the color-developed portion decreases with time cannot be avoided.

Further, JP-A-5-124360 discloses a reversible thermosensitive recording medium which develops and decolorizes a leuco dye by heating, and an organic phosphoric acid compound and α-hydroxy aliphatic compound as an electron-accepting compound. Specific phenol compounds such as carboxylic acids, fatty acid dicarboxylic acids, and alkylthiophenols having an aliphatic group having 12 or more carbon atoms, alkyloxyphenols, alkylcarbamoylphenols, and gallic acid alkylesters are exemplified. However, even with this recording medium, the two problems of low color density or incomplete decolorization cannot be solved at the same time, and the temporal stability of the image is not satisfactory in practice.

As described above, the conventional technique has good image contrast, enables formation and erasing of an image, and has no practical change in color density even when color development and decoloration are repeated many times. No thermosensitive recording material was known.

The present applicant has found a novel reversible color developer capable of forming and erasing an image with good contrast and maintaining a stable image over time in an environment of daily life. It was previously proposed in Japanese Patent Application No. 4-347032. However, in the reversible thermosensitive recording material obtained by this method, if coloring and erasing are repeated at the same location, the recording layer deteriorates and the printing density decreases, and the water resistance of the recording layer is insufficient. However, there is a problem that the recording layer swells or peels off when it is immersed in water for a long time. In contrast,
Japanese Patent Application Laid-Open No. 6-8626 proposes a curing reaction product of polyvinyl butyral and an isocyanate compound in the protective layer, but when the number of repetitions increases, there are problems such as print density reduction and insufficient water resistance. Still there.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reversible thermosensitive recording material which is capable of forming an image and erasing the image, has little damage by repeated use of coloring and decoloring, and has high water resistance. To provide.

[0012]

Means for Solving the Problems The present inventor has conducted a study to solve this problem. As a result, at least one surface of the support is usually provided with a colorless or pale-color electron-donating dye precursor,
A reversible thermosensitive recording material is provided with a reversible thermosensitive recording layer containing a reversible color developer that develops color of the dye precursor by heating and reheats the dye precursor to produce a polyvinyl chloride in the reversible thermosensitive recording layer. This problem has been solved by using a reversible thermosensitive recording material characterized by containing an acetal resin.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present applicant has developed a novel reversible color developing device capable of forming and erasing an image with good contrast and maintaining a stable image over time in an environment of daily life. An agent has been found and previously proposed in JP-A-6-210954. However, in the reversible thermosensitive recording material obtained by this method, when coloring and erasing are repeated at the same location, deterioration or cracking of the recording layer due to pressurization and heating of the thermal head occurs, or the reversible thermosensitive layer is formed. There was a problem of peeling. There is also a problem that the water resistance of the recording layer is insufficient, especially when the recording layer is immersed in water for a long time, the recording layer swells or peels off.

The inventors of the present invention have solved the above problems and studied electron donor dye precursors, reversible color developers and their dispersants and adhesives. As a result, polyvinyl chloride in the reversible thermosensitive recording layer has been found. By using acetal resin,
We have succeeded in obtaining a reversible thermosensitive recording layer which has good adhesiveness without impairing color development and has sufficient dispersibility. Since polyvinyl acetal resin has relatively high heat resistance, it is excellent in durability against repeated coloring and decoloring by a thermal head, and polyvinyl acetal resin has good water resistance because most of the hydroxyl groups of polyvinyl alcohol are acetalized. Have sex. However, recently, reversible thermosensitive recording materials are often used for high-value-added media such as prepaid cards and stored fair cards, and even when immersed in water for a long time, the reversible layer does not swell or peel off. Is required. In such a case, it is desirable to use an isocyanate compound in the reversible thermosensitive layer to crosslink the residual hydroxyl groups of the polyvinyl acetal. Using an isocyanate compound contributes not only to water resistance but also to heat resistance and adhesiveness.

The polyvinyl acetal resin used in the present invention is obtained by acetalizing polyvinyl alcohol or modified polyvinyl alcohol with aldehydes. Examples of the modified polyvinyl alcohol include those modified with a carboxyl group, a sulfone group, or the like. Examples of acetalizing aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, amylaldehyde,
Hexyl aldehyde, 2-ethylhexyl aldehyde,
Examples thereof include cyclohexyl aldehyde, furfural, glyoxal, and glutaraldehyde, and these aldehydes may be used alone or in combination of two or more. In particular, a polyvinyl acetal resin acetalized with acetaldehyde or butyraldehyde is particularly preferable, and as the chemical structural formula, those in which the hydroxyl group of polyvinyl alcohol is acetalized and the remaining hydroxyl group and the unsaponified portion of polyvinyl alcohol are included. A resin having an acetyl group, presumed to be the following chemical formula 1.
In addition, the degree of acetalization is 3 to 3 in total degree of acetalization.
A range of 81 mol% is preferred.

[0016]

Embedded image

When the above polyvinyl acetal resin is used, it is necessary to prepare a resin solution and disperse and mix the electron donating dye precursor and the reversible developer. The solubility of such a polyvinyl acetal resin is mainly determined by the type of aldehyde to be acetalized and its degree of acetalization. When the polyvinyl acetal resin is water-soluble and the reversible thermosensitive recording layer is produced in an aqueous medium, not only when the water resistance is insufficient, but also the viscosity of the dispersion is high, or bubbles are easily generated during stirring and mixing. Have the problem of. The solvent used is particularly preferably a mixture of water and alcohol, and the alcohol content in the solvent is 20 to 100%.
Is preferred. A solution of such a polyvinyl acetal resin is excellent in the dispersibility of the reversible color developer and the dye precursor, and it is possible to easily obtain uniform fine particles. A reversible thermosensitive recording material having a coating film is obtained. The amount of the polyvinyl acetal resin used is 1 in total of the reversible developer and the electron-donating dye precursor.
The amount is preferably 5 to 500 parts, more preferably 10 to 100 parts, relative to 00 parts.

It is also advantageous to crosslink the polyvinyl acetal resin in the reversible thermosensitive layer with a di- or tri- or more isocyanate compound, if necessary. The addition amount of the isocyanate compound used is preferably about 0.8 to 1.2 equivalents of isocyanate groups with respect to 1 equivalent of hydroxyl groups in the polyvinyl acetal resin.
In the present invention, the crosslinking reaction is carried out in the reversible thermosensitive layer, but the reaction temperature may be 50 to 160 ° C. and the reaction time may be 0.1 to 100 hours. Needless to say, a long reaction time is required when the reaction temperature is low, and a short time is required when the reaction temperature is high. Specific examples of the isocyanate compound used in the present invention include 2,4-tolylene diisocyanate, p-phenylene diisocyanate, hexamethylene diisocyanate, triphenylmethane triisocyanate and 4,4.
Examples include di- or triisocyanates such as'-biphenylene diisocyanate.

The electron-donating dye precursor used in the present invention is typified by those generally used for pressure-sensitive recording paper and heat-sensitive recording paper, but is not particularly limited.
Specific examples include the following,
The present invention is not limited to this. (1) Triarylmethane compound 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-phenylindole-
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-phenylindol-3-yl) -5 -Dimethylaminophthalide, 3-p
-Dimethylaminophenyl-3- (1-methylpyrrol-2-yl) -6-dimethylaminophthalide and the like,

(2) Diphenylmethane compound 4,4'-bis (dimethylaminophenyl) benzhydryl benzyl ether, N-chlorophenyl leuco auramine, N-2,4,5-trichlorophenyl leuco auramine, etc.

(3) Xanthene compounds rhodamine B anilinolactam, rhodamine Bp-chloroanilinolactam, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-7-octylaminofluoran, 3- Diethylamino-7-phenylfluoran, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-chloro-7-methylfluoran, 3-diethylamino-7- (3,4-dichloroanilino) fluoran, 3 -Diethylamino-7
-(2-chloroanilino) fluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3- (N
-Ethyl) tolylamino-6-methyl-7-anilinofluoran, 3-piperidino-6-methyl-7-anilinofluoran, 3- (N-ethyl) tolylamino-6-methyl-7-phenethylfluoran, 3-diethylamino-7- (4-nitroanilino) fluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3-
(N-Methyl) propylamino-6-methyl-7-anilinofluorane, 3- (N-ethyl) isoamylamino-6-methyl-7-anilinofluorane, 3- (N-methyl) cyclohexylamino- 6-methyl-7-anilinofluorane, 3- (N-ethyl) tetrahydrofurylamino-6-methyl-7-anilinofluorane and the like,

(4) Thiazine compounds Benzoyl leucomethylene blue, p-nitrobenzoyl leucomethylene blue, etc.

(5) Spiro compounds 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3,3'-dichlorospirodinaphthopyran, 3-benzylspirodinaphthopyran, 3-methylnaphtho- (3 -Methoxybenzo) spiropyran, 3-propylspirobenzopyran and the like.

The above-mentioned usually colorless to light-colored electron-donating dye precursors may be used either individually or in combination of two or more.

The reversible color developer used in the present invention includes, for example, those represented by the general formula 2, but is not limited thereto, and a reversible change in color tone is caused to the dye precursor by heating. The compound is not particularly limited as long as it is a compound capable of generating, but the following compounds including a reversible color developing agent composed of a phenolic compound proposed by JP-A-6-210954 by the present applicant in view of image contrast, durability against repetition, etc. The electron-accepting compound represented by 2 is preferably used.

[0026]

Embedded image

In Formula 2, n represents 1, 2 or 3. m represents 0, 1 or 2. Q represents an aliphatic hydrocarbon group, an alkoxy group, or a halogen atom. The ring represented by A is an aromatic ring. X is a divalent group bonded to the aromatic ring represented by A via a nitrogen atom, a divalent group containing two or more hetero atoms, a nitrogen atom-containing aromatic ring represented by A, It represents a divalent group bonded by the above hydrocarbon group, or a divalent group containing an unsaturated bond or an aromatic ring. R represents an aliphatic hydrocarbon group. The total number of the atoms included in X and R excluding the hydrogen atoms and the atoms constituting the aromatic ring is 8 or more. Specific examples of the substituent represented by Q include a methyl group,
Ethyl group, propyl group, isopropyl group, n-butyl group, t-butyl group, t-pentyl group, 2-ethylhexyl group, cyclohexyl group, aliphatic hydrocarbon group such as allyl group, methoxy group, ethoxy group, n- Propyloxy group,
Examples thereof include alkoxy groups such as i-propyloxy group, n-butyloxy group and n-octyloxy group, and halogen atoms such as fluorine, chlorine, bromine and iodine.

Examples of the divalent group in which X is bonded to the aromatic ring represented by A via a nitrogen atom include -NHCO-,-
NH-, -NHCONH-, -NHCONHNH-,-
N = CH -, - N = N -, - NHSO 2 -, - NHCO
_{(P-C 6 H 4)} NHCO -, - NHCO (p-C 6 H 4)
NHCONH -, - NHCO (p- C 6 H 4) NHCOC
ONH -, - NHCO (p- C 6 H 4) CONH -, - N
_{HCO (p-C 6 H 4} ) CONHNHCO -, - NHCO
_{(P-C 6 H 4)} OCONH -, - NHCO (p-C
₆ H ₄ ) NHCOO-, -NHCOCH ₂ (m-C ₆ H ₄ ).
_{NHCO -, - NHCOCH 2 (p} -C 6 H 4) NHCO
_{-, - NHCOCH 2 (p-} C 6 H 4) NHCONH-,
_{-NHCOCH 2 (p-C 6 H} 4) NHCOCONH-,
_{-NHCOCH 2 (p-C 6 H} 4) CONH -, - NHC
_{OCH 2 (p-C 6 H} 4) CONHNHCO -, - NHC
_{OCH 2 (p-C 6 H} 4) CONHNHCONH -, - N
HCOCH ₂ (p-C ₆ H ₄ ) CONNHNHCOO-,-
_{NHCOCH 2 (p-C 6 H} 4) OCONH -, - NHC
_{OCH 2 (p-C 6 H} 4) NHCOO -, - NHCOCH 2
_{CH 2 (p-C 6 H} 4) NHCO -, - NHCOCH 2 CH
_{2 (p-C 6 H 4} ) NHCONH -, - NHCOCH 2 CH
_{2 (m-C 6 H 4} ) NHCOO -, - NHCOCH 2 CH 2
_{(P-C 6 H 4)} NHCOCONH -, - NHCOCH 2
_{CH 2 (p-C 6 H} 4) CONH -, - NHCOCH 2 CH
_{2 (p-C 6 H 4} ) CONHNHCO -, - NHCOCH 2
_{CH 2 (p-C 6 H} 4) CONHNHCONH- the like. When a hydrogen atom is bonded to the nitrogen atom, the hydrogen atom may be substituted with an aliphatic hydrocarbon group such as a methyl group or a cyclohexyl group. Of these, the urea bond is more preferable in terms of decoloring property and image density. Interestingly, when X is -CONH-, -COO-, -S-
Either the decoloring property or the image density becomes unsatisfactory.

X is a divalent group containing two or more heteroatoms
As an example of_TwoNH-, -SS-, -CON
HNH-, -CONHNHCO-, -CONHCH_TwoC
O-, -CONHNHCOO-, -CONHCH_TwoCO
O-, -CONHNHCONH-, -CONHCH_TwoC
ONH-, -CONHNHCONHNH-, -CONH
CH_TwoCONHNH-, -CH_TwoNHCONH-, -CH
_TwoCH_TwoNHCONH-, -CH_TwoCH_TwoCH_TwoNHCON
H-, -CH_TwoCH_TwoCH_TwoNHCONH-, -SCH_TwoC
ONH-, -SCH_TwoCH_TwoCONH-, -S (CH_Two)_Five
CONH-, -S (CH_Two)_TenCONH-, -S (p-
C₆H_Four) CONH-, -SCH_TwoNHCO-, -SCH_Two
CH_TwoNHCO-, -S (CH_Two)₆NHCO-, -S
(P-C₆H_Four) NHCO-, -SCH_TwoNHCONH
-, -SCH_TwoCH_TwoNHCONH-, -S (CH_Two)₆N
HCONH-, -S (p-C₆H_Four) NHCONH-,-
S (CH _Two)_TenNHCONH-, -SCH_TwoCH_TwoNHC
OO-, -S (CH_Two)₆NHCOO-, -S (p-C₆
H_Four) NHCOO-, -S (CH_Two)₆OCONH-,-
S (p-C₆H_Four) OCONH-, -S (CH_Two)₁₁OC
ONH-, -SCH_TwoCH_TwoCONH-, -S (CH_Two)_Five
CONH-, -SCH_TwoCH_TwoNHCO (p-C₆H_Four)
-, -SCH_TwoCONHNHCO-, -SCH_TwoCH_TwoC
ONHNHCO-, -S (CH_Two)₆CONHNHCO
-, -S (CH_Two)₆CONHNHCO (p-C₆H_Four)
-, -S (CH_Two)_TenCONHNHCO-, -S (p-
C₆H_Four) CONHNHCO-, -SCH_Two(P-C
₆H_Four) CONHNHCO-, -SCH_TwoCH_TwoNHCOC
ONH-, -SCH_TwoCH_TwoCH_TwoNHCOCONH-,
-S (CH_Two)₁₁NHCOCONH-, -S (p-C₆H
_Four) NHCOCONH-, -SCH_TwoCONHCONH
-, -SCH_TwoCH_TwoCONHCONH-, -S (p-C
₆H_Four) CONHCONH-, -SCH_TwoCH_TwoNHCON
HCO-, -S (p-C₆H_Four) NHCONHCO-,-
SCH_TwoCH_TwoCONHNHCONH-, -S (CH_Two)
_TenCONHNHCONH-, -SCH_TwoCH_TwoNHNHC
ONH-, -S (p-C₆H_Four) NHNHCONH-,-
SCH_TwoCH_TwoNHCONHNH-, -S (p-C₆H_Four)
NHCONHNH-, -SCH_TwoCONHCONHNH
-, -SCH_TwoCH_TwoCONHCONHNH-, -S (C
H_Two)_{1 0}CONHCONHNH-, -S (p-C₆H_Four)
CONHNHCONH-, -S (p-C₆H_Four) CONH
CONHNH-, -SCH_TwoCONHCONHNHCO
-, -SCH_TwoCH_TwoCONHCONHNHCO-, -S
(CH_Two)_TenCONHCONHNHCO-, -S (p-
C₆H_Four) CONHNHCONHCO-, -S (p-C₆
H_Four) CONHCONHNHCO-, -SCH_TwoCONH
(CH_Two) NHCO-, -SCH_TwoCH_TwoCONH (C
H_Two) NHCO-, -S (p-C₆H_Four) CONH (C
H_Two) NHCO-, -S (CH_Two)_TenCONH (CH_Two)
NHCO-, -SCH_TwoCON (CH_Two) NHCONH
-, -SCH_TwoCH_TwoCON (CH_Two) NHCONH-,
-S (CH_Two)_TenCONHCONH (CH_Two) NHCO
-, -S (p-C₆H_Four) CONH (CH_Two) NHCO
-, -SCH_TwoCH_TwoNHCONH (CH_Two) NHCO
-, -SCH_TwoCH_TwoNHCOCH_TwoCONH-, -S
(P-C₆H_Four) NHCONH (CH_Two) NHCO-,-
S (p-C₆H_Four) NHCOCH_TwoCONH- and the like
It is. Specific examples of the hetero atom include oxygen atom and nitrogen atom.
Child, sulfur atom, phosphorus atom, boron atom, silicon atom, selenium
Atom, fluorine atom, chlorine atom, bromine atom, iodine atom, tin
An atom etc. are mentioned.

X is an unsaturated bond or an aromatic ring containing 2
Examples of the valent group include -CH = CH-, -CH = N-,
—SO ₂ —, a phenylene group, a group containing a carbon-carbon triple bond and the like, a group obtained by combining them, and further, on one or both sides thereof, —NHCO
-, -NH-, -NHCONH-, -NHCSNH-,
-N = CH -, - N = N -, - NHSO 2 -, - SO 2 N
A group in which one or two or more linking groups such as H and -S-S- are combined is exemplified. In this case, in addition to the linking group, -CONH-, -O-, -S-, -COO-, -O.
Divalent groups such as CO—, —OCOO, —CO—, and —SO ₂ — are also included.

Examples of the divalent group in which X contains a nitrogen atom and is bonded to the aromatic ring represented by A by a hydrocarbon group having 1 or more carbon atoms include -CH ₂ CONH- and -CH ₂ CH ₂ CO
_{NH -, - CH 2 NHCO -} , - CH 2 CH 2 NHCO
_{-, - CH 2 CH 2 CH} 2 NHCO -, - CH 2 CH 2 NH
_{COO -, - (CH 2)} 6 NHCOO -, - (p-C
_{6 H 4) NHCOO -, -} CH 2 CH 2 OCONH -, -
_{(CH 2) 11 OCONH -,} - (p-C 6 H 4) OCON
_{H -, - CH 2 CH 2} CONHCO -, - (CH 2) 5 CO
_{NHCO -, - CH 2 CH 2} CONHCO (p-C 6 H 4)
_{-, - CH 2 CONHNHCO -,} - CH 2 CH 2 CON
_{HNHCO -, - (CH 2)} 5 CONHNHCO -, -
_{(CH 2) 5 CONHNHCO (p} -C 6 H 4) -, - (C
_{H 2) 10 CONHNHCO -, -} (p-C 6 H 4) CON
_{HNHCO -, - CH 2 (p} -C 6 H 4) CONHNHC
_{O -, - CH 2 CH 2} NHCOCONH -, - CH 2 CH 2
_{CH 2 NHCOCONH -, - (CH} 2) 10 NHCOCO
NH -, - (p-C 6 H 4) NHCOCONH -, - CH
_{2 CONHCONH -, - CH 2 CH} 2 CONHCONH
_{-, - (p-C 6} H 4) CONHCONH -, - CH 2 C
_{H 2 NHCONHCO -, - (p} -C 6 H 4) NHCON
_{HCO -, - CH 2 CH 2} NHCONHNH -, - (p-
_{C 6 H 4) NHCONHNH -,} - CH 2 CH 2 NHNHC
ONH -, - (p-C 6 H 4) NHNHCONH -, - C
_{H 2 CONHNHCONH -, - CH 2} CH 2 CONHN
_{HCONH -, - (CH 2)} 10 CONHNHCONH
_{-, - (p-C 6} H 4) NHNHCO -, - CH 2 CON
_{HCH 2 NHCO -, - CH 2} CH 2 CONHCH 2 NHC
_{O -, - (CH 2)} 10 CONHCH 2 NHCO -, - (p
_{-C 6 H 4) CONHCH 2 NHCO} -, - CH 2 CONH
_{CH 2 NHCONH -, - CH 2} CH 2 CONHCH 2 NH
_{CONH -, - (CH 2)} 10 CONHCH 2 NHCONH
_{-, - (p-C 6} H 4) CONHCH 2 NHCONH-,
_{-CH 2 CH 2 NHCONHCH 2 NHCO -} , - (p-
_{C 6 H 4) NHCONHCH 2 NHCO} -, - CH 2 CH 2
_{NHCOCH 2 CONH -, - (p} -C 6 H 4) NHCO
CH ₂ CONH— and the like.

As the aliphatic hydrocarbon group represented by R,
Hexyl, octyl, nonyl, cyclohexyl, decyl, undecyl, dodecyl, cyclododecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, 16-methylheptadecyl, octadecyl, 9-octadecenyl group, nonadecyl group, eicosyl group, henicosyl group,
Examples thereof include docosyl group, tricosyl group, tetracosyl group, 2-norbornyl group, 7,7-dimethylnorbornyl group, 1-adamantyl group, cholesteryl group and 5-phenylpentyl group. These may be branched, may be polycyclic, and may contain an unsaturated bond. However, it is necessary for the decoloring property that the total number of the atoms included in X and R excluding the hydrogen atom and the atoms constituting the aromatic ring is 8 or more, particularly 14 or more.

Next, specific examples of the reversible developer preferably used in the present invention will be described, but the present invention is not limited thereto.

4'-hydroxyheptaneanilide, 4 '
-Hydroxy-3-methyloctaneanilide, 4'-hydroxynonadecaneanilide, 3'-hydroxynonadecaneanilide, 4'-hydroxy-10-octadeceneanilide, 15-cyclohexyl-4'-hydroxypentadecaneanilide, 4'- Hydroxy-5-tetradeceneanilide, 3'-cyclohexyl-4'-hydroxyheptadecaneanilide, 3'-allyl-4'-hydroxypentadecaneanilide, 3'-chloro-4'-hydroxyoctadecananilide, 3'-hydroxydodecane Anilide, 2 ', 4'-dihydroxyheptadecane anilide,

4'-hydroxy-4-hexylbenzanilide, 4'-hydroxy-4-octadecylbenzanilide, 4'-hydroxy-4-pentadecylaminocarbonylbenzanilide, 4'-hydroxy-4-hexylcarbonylaminobenz Anilide, 4'-hydroxy-4- (heptylthio) benzanilide, 4'-hydroxy-4-octadecyloxybenzanilide, 4 '
-Hydroxy-4-dodecylsulfonylbenzanilide, 4'-hydroxy-4-nonylsulfonyloxybenzanilide, 4'-hydroxy-4-dodecyloxysulfonylbenzanilide, 4'-hydroxy-4-pentadecylaminosulfonylbenzanilide, 4'-hydroxy-4- (N-heptadecylideneamino) benzanilide,

4'-hydroxy-3,4-dioctyloxybenzanilide, 4'-hydroxy-3-octyl-4- (octylthio) benzanilide, 4'-hydroxy-3- (heptadecylthio) -5-pentadecyloxybenz Anilide, 4'-hydroxy-3-heptadecylcarbonylamino-5-dodecylbenzanilide,
4'-hydroxy-3-octadecylaminocarbonyl-5-tetradecylaminocarbonylbenzanilide,
4'-hydroxy-3-octadecylsulfonylamino-5-octadecyloxybenzanilide, 4'-hydroxy-3-heptadecyloxysulfonyl-5-tetradecyloxysulfonylbenzanilide, 4'-hydroxy-3,5-bis ( N-docosylideneamino) benzanilide;

4'-hydroxy-4-octadecylcarbonylaminobenzanilide, 4'-hydroxy-3-
Octadecylcarbonylamino-5-octadecyloxybenzanilide, 3'-allyl-4'-hydroxy-
4-pentadecylbenzanilide, 4'-hydroxy-
3'-methyl-4-nonyloxybenzanilide, 4 '
-Hydroxy-3'-propyl-4-nonadecylcarbonyloxybenzanilide, 3'-butyl-4'-hydroxy-4-octadecyloxycarbonylbenzanilide, 3'-hydroxy-4-pentadecylcarbonyloxybenzanilide, '-Hydroxy-4-nonadecylsulfonylbenzanilide, 3', 4 ', 5'-trihydroxy-4-tetracosylaminosulfonylbenzanilide, 3', 5'-dihydroxy-4-pentacosylaminocarbonylbenz Anilide, 3'-hydroxy-4- (N-dodecylideneamino) benzanilide,
N- [4- (3-hydroxyphenylaminocarbonyl) benzylidene] pentadecylamine;

N-cyclohexyl-4-hydroxybenzhydrazide, N-cyclohexylmethyl-4-hydroxybenzhydrazide, N-cyclohexyl-4-hydroxybenzamide, N-cyclohexylmethyl-4-
Hydroxybenzamide, N-methyl-N-octadecyl-4-hydroxybenzamide, N- (3-methylhexyl) -4-hydroxybenzamide, N-octadecyl-4-hydroxybenzhydrazide, N- (8-octadecenyl) -4- Hydroxybenzamide,

4-hydroxy-4'-dodecylbenzanilide, N-methyl-4-hydroxy-4'-octadecylbenzanilide, 4-hydroxy-4'-octadecyloxybenzanilide, 4-hydroxy-4'-
(Octadecylthio) benzanilide, 4-hydroxy-4'-hexadecylcarbonylbenzanilide, 4-
Hydroxy-4′-heptadecyloxycarbonyloxybenzanilide, 4-hydroxy-4′-dodecyloxycarbonylbenzanilide, 4-hydroxy-4 ′
-Heptadecyl carbonyloxybenzanilide, 4-
Hydroxy-4'-cyclohexylaminobenzanilide, 4-hydroxy-4'-octadecylaminobenzanilide,

4-hydroxy-4'-heptadecylcarbonylaminobenzanilide, 4-hydroxy-4'-
Octadecylaminocarbonylbenzanilide, 4-hydroxy-4'-dodecylsulfonylbenzanilide, 4-hydroxy-4'-octadecyloxysulfonylbenzanilide, 4-hydroxy-4'-dodecylsulfonyloxybenzanilide, N-4-hydroxybenzoyl -N'-octadecylidene-1,4-phenylenediamine, N-4- (4-hydroxyphenylcarbonylamino) benzylidenedecylamine, 4-
Hydroxy-4'-tetradecyloxycarbonylaminobenzanilide, 4-hydroxy-4'-octadecylureylenebenzanilide,

3-hydroxy-4'-dodecyloxybenzanilide, N-methyl-4-hydroxy-3'-octadecyloxybenzanilide, 3-hydroxy-
4'-tetradecylbenzanilide, N-methyl-3-
Hydroxy-4'-octadecylbenzanilide, N-
Dodecyl-4-hydroxy-3-methylbenzamide,
3-methoxy-4-hydroxy-4'-octadecyloxybenzanilide, 3-chloro-4-hydroxy-
4'-octadecylbenzanilide, N-octadecyl-4-hydroxy-2,5-dimethylbenzamide, 4
-Hydroxy-4'-octadecyloxy-3'-chlorobenzanilide, 4-hydroxy-3 ', 4'-didecyloxybenzanilide, 4-hydroxy-3'-octadecylamino-4'-octadecyloxybenzanilide, 4-hydroxy-2'-chloro-3 ', 5'-
Didecyloxybenzanilide, 4-hydroxy-
3 ', 4'-dioctadecyloxybenzanilide, 4
-Hydroxy-4'-octyl-3'-methylbenzanilide, 3-hydroxy-4-methyl-4'-tetradecylbenzanilide, N-methyl-4-hydroxy-
3'-octadecylbenzanilide,

4- (N-octadecylsulfonylamino) phenol, 4- (N-methyl-N-octadecylsulfonylamino) phenol, 4- (N-3-methylhexylsulfonylamino) phenol, 4'-hydroxy-4- Cyclohexylbenzenesulfonanilide,
4'-hydroxy-4-octadecyloxybenzenesulfonanilide, 4'-hydroxy-4- (dodecylthio) benzenesulfonanilide, 4'-hydroxy-4
-Hexylcarbonylbenzenesulfonanilide, 4 '
-Hydroxy-4- (8-heptadecenyl) carbonylbenzenesulfonanilide, 4'-hydroxy-4-octyloxycarbonyloxybenzenesulfonanilide, 4'-hydroxy-4-dodecylcarbonyloxybenzenesulfonanilide, 4'-hydroxy-4 -Octadecylaminobenzenesulfoneanilide,

4'-hydroxy-4-heptadecylcarbonylaminobenzenesulfonanilide, 4'-hydroxy-4-dodecylaminocarbonylbenzenesulfonanilide, 4'-hydroxy-4-dodecylsulfonylbenzenesulfonanilide, 4'-hydroxy- 4-octadecyloxysulfonylbenzenesulfonanilide, 4'-hydroxy-4-dodecylsulfonyloxybenzenesulfonanilide, N-dodecylidene-4-
(4-hydroxyphenyl) aminosulfonylaniline, N-4- (4-hydroxyphenylaminosulfonyl) benzylideneoctadecylamine, 4'-hydroxy-4-octyloxycarbonylaminobenzenesulfonanilide, 4'-hydroxy-4-octadecyloxy Carbonylaminobenzenesulfonanilide, 4 '
-Hydroxy-4-octadecylureylenebenzenesulfonanilide,

N-methyl-4'-hydroxy-3-octadecyloxybenzenesulfonanilide, 3'-hydroxy-4-dodecylbenzenesulfonanilide, 3-
Methyl-4- (N-dodecylsulfonamino) phenol, 3'-methoxy-4'-hydroxy-4-octadecyloxybenzenesulfonanilide, 3'-chloro-
4'-hydroxy-4-octadecylbenzenesulfonanilide, 4'-hydroxy-2,5-dimethyl-4-
Octadecylbenzenesulfonanilide, 3-methyl-
4- (N-octadecylsulfonamino) phenol,
4'-hydroxy-3,4-dioctadecyloxybenzenesulfonanilide,

1- (4-hydroxyphenyldithio) octadecane, 1- (4-hydroxyphenyldithio)-
9-octadecene, 1- (2-fluoro-4-hydroxyphenyldithio) octadecane, 1- (2-ethoxy-4-hydroxyphenyldithio) octadecane, 1-
(3-chloro-4-hydroxyphenyldithio) octadecane,

4'-hydroxy-4-tetradecyldiphenyl sulfide, 4'-hydroxy-4-octadecyldiphenyl sulfide, 4'-hydroxy-4-octadecylcarbonylaminodiphenyl sulfide, 4 '
-Hydroxy-4-octadecyloxydiphenyl sulfide, 4'-hydroxy-4-octadecyloxysulfonyl diphenyl sulfide, 4'-hydroxy-4
-Octadecylsulfonylaminodiphenyl sulfide,

4'-hydroxy-3,4-didecyloxydiphenyl sulfide, 4'-hydroxy-3,4-
Dioctadecyloxydiphenyl sulfide, 4- (1
5-cyclohexylpentadecyl) -4'-hydroxydiphenyl sulfide, 4'-hydroxy-4- (5-
Tetradecenyl) diphenyl sulfide,

3'-chloro-4'-hydroxy-4-octadecyldiphenyl sulfide, 3'-hydroxy-
4-dodecyldiphenyl sulfide, 3'-hydroxy-4-octadecyldiphenyl sulfide, 3'-hydroxy-4-dodecyloxycarbonyldiphenyl sulfide,

N- (4-hydroxyphenyl) -N'-
Hexylurea, N- (4-hydroxyphenyl) -N '
-Dodecyl urea, N- (4-hydroxyphenyl)-
N'-hexadecyl urea, N- (4-hydroxyphenyl) -N'-octadecyl urea, N- (4-hydroxyphenyl) -N'-icosyl urea, N- (4-hydroxyphenyl) -N'-cyclododecyl Urea, N- (4
-Hydroxyphenyl) -N'-docosylurea, N-
(4-hydroxyphenyl) -N'-cholesteryl urea, N- (4-hydroxyphenyl) -N '-(2-heptyloctyl) urea, N- (4-hydroxyphenyl) -N'-(9-octadecenyl) urea,

N- (3-allyl-4-hydroxyphenyl) -N'-octadecylurea, N- (2-hydroxyphenyl) -N'-octylurea, N- (3-hydroxyphenyl) -N'-octadecyl Urea, N- (3,4
-Dihydroxyphenyl) -N'-octadecylurea,
N- (3,4,5-trihydroxyphenyl) -N'-
Tricosyl urea, N- (4-hydroxyphenyl)-
N '-(4-tetradecylphenyl) urea, N- (4-
(Hydroxyphenyl) -N′-hexadecylthiourea,
N- (4-hydroxyphenyl) -N'-octadecylthiourea;

4-undecanoylamino-1- (4-hydroxyphenylaminocarbonyl) benzene, 4-octadecanoylamino-1- (4-hydroxyphenylaminocarbonyl) benzene, 4- (octadecylaminocarbonyl) amino- 1- (4-hydroxyphenylaminocarbonyl) benzene, 4-octadecylamino-1- (4-hydroxyphenylamino) carbonylmethylbenzene, N-octadecyl-N'-p- (4-hydroxyphenylcarbamoyl) phenyl oxamide,
4- (octadecylaminocarbonyl) amino-1-
(4-hydroxyphenylcarbamoyl) methylbenzene, 4- (octadecylamino) carbonyl-1- (4
-Hydroxyphenylcarbamoyl) methylbenzene,
N-octadecanoyl-N'-p- (p-hydroxyphenylcarbamoylmethyl) benzoylhydrazine, N
-Dodecanoyl-N'-p- [2- (p-hydroxyphenylcarbamoyl) ethyl] benzoylhydrazine,

N- (4-hydroxyphenylmethyl)-
N'-n-tetradecyl urea, N- (4-hydroxyphenylmethyl) -N'-n-octadecyl urea, N-
[2- (4-hydroxyphenyl) ethyl] -N'-n
-Tetradecyl urea, N- [2- (4-hydroxyphenyl) ethyl] -N'-n-octadecyl urea, N-
[3- (4-hydroxyphenyl) propyl] -N'-
n-dodecyl urea, N- [3- (4-hydroxyphenyl) propyl] -N'-n-octadecyl urea, N-
[6- (4-hydroxyphenyl) hexyl] -N'-
n-dodecyl urea, N- [2- (3-hydroxyphenyl) ethyl] -N'-n-octadecyl urea, N- [2
-(3,4-dihydroxyphenyl) ethyl] -N'-
n-octadecyl urea,

Nn-octadecyl- (4-hydroxyphenyl) acetamide, Nn-dodecyl-3- (4
-Hydroxyphenyl) propanamide, Nn-octadecyl-3- (4-hydroxyphenyl) propanamide, N- (4-hydroxyphenylmethyl) octadecane amide, N- [2- (4-hydroxyphenyl) ethyl] octadecane Amide, N- [3- (4-hydroxyphenyl) propyl] octadecanamide, N- [3
-(3-hydroxyphenyl) propyl] octadecanamide, N- [3- (3,4-dihydroxyphenyl)
Propyl] octadecanamide,

N- (4-hydroxybenzoyl) -N '
-N-octanoylhydrazine, N- (4-hydroxybenzoyl) -N'-n-tetradecanoylhydrazine, N- (4-hydroxybenzoyl) -N'-n-octadecanoylhydrazine, N- (2, 4-dihydroxybenzoyl) -N'-n-octanoylhydrazine,
N- (2,4-dihydroxybenzoyl) -N'-n-
Octadecanoylhydrazine, N- (4-hydroxybenzoyl) -N'-n-tetradecylaminocarbonylhydrazine, N- (4-hydroxybenzoyl) -N '
-N-octadecylaminocarbonylhydrazine, N-
(2,4-dihydroxybenzoyl) -N'-n-tetradecylaminocarbonylhydrazine, N- (2,4-
Dihydroxybenzoyl) -N'-n-octadecylaminocarbonylhydrazine, N- (4-hydroxybenzoyl) -N'-n-octyloxycarbonylhydrazine, N- (4-hydroxybenzoyl) -N'-n-
Dodecyloxycarbonylhydrazine, N- (2,4-
Dihydroxybenzoyl) -N'-n-tetradecyloxycarbonylhydrazine, N- (2,4-dihydroxybenzoyl) -N'-n-octadecyloxycarbonylhydrazine, N- (4-hydroxybenzoyl)-
N'-n-tetradecylhydrazinocarbonylhydrazine, N- (4-hydroxybenzoyl) -N'-n-octadecylhydrazinocarbonylhydrazine, N-
(2,4-dihydroxybenzoyl) -N'-n-tetradecylhydrazinocarbonylhydrazine, N- (2
4-dihydroxybenzoyl) -N'-n-octadecylhydrazinocarbonylhydrazine;

N- (4-hydroxybenzoyl) -N '
-N-octanoylmethylenediamine, N- (4-hydroxybenzoyl) -N'-n-tetradecanoylmethylenediamine, N- (4-hydroxybenzoyl)-
N'-n-octadecanoyl methylenediamine, N-
(2,4-dihydroxybenzoyl) -N'-n-tetradecanoylmethylenediamine, N- (2,4-dihydroxybenzoyl) -N'-n-octadecanoylmethylenediamine, N- (4-hydroxybenzoyl) −
N'-n-octylaminocarbonylmethylenediamine, N- (4-hydroxybenzoyl) -N'-n-dodecylaminocarbonylmethylenediamine, N- (4-
(Hydroxybenzoyl) -N'-n-tetradecylaminocarbonylmethylenediamine, N- (4-hydroxybenzoyl) -N'-n-octadecylaminocarbonylmethylenediamine, N- (2,4-dihydroxybenzoyl) -N'- n-octadecylaminocarbonylmethylenediamine, N- (4-hydroxybenzoyl)-
N'-n-tetradecyloxycarbonylmethylenediamine, N- (4-hydroxybenzoyl) -N'-n-
Octadecyloxycarbonylmethylenediamine, N-
(2,4-dihydroxybenzoyl) -N'-n-tetradecyloxycarbonylmethylenediamine, N-
(2,4-dihydroxybenzoyl) -N'-n-octadecyloxycarbonylmethylenediamine, N- (4
-Hydroxybenzoyl) -N'-n-octylhydrazinocarbonylmethylenediamine, N- (4-hydroxybenzoyl) -N'-n-dodecylhydrazinocarbonylmethylenediamine, N- (2,4-dihydroxybenzoyl) -N '-N-tetradecylhydrazinocarbonylmethylenediamine, N- (2,4-dihydroxybenzoyl) -N'-n-octadecylhydrazinocarbonylmethylenediamine,

Nn-octadecyl-2- (p-hydroxyphenylthio) acetamide, Nn-octadecyl-3- (p-hydroxyphenylthio) propanamide, Nn-decyl-11- (p-hydroxy Phenylthio) undecaneamide, N- (pn-octylphenyl) -6- (p-hydroxyphenylthio) hexanamide, Nn-octadecyl-p- (p-hydroxyphenylthio) benzamide, N- [2 -(P-hydroxyphenylthio) ethyl] -n-octadecanamide, N- [p- (p-hydroxyphenylthio) phenyl] -n-octadecanamide, N- (p-hydroxyphenylthio) methyl-N'- n-octadecyl urea,
N- [2- (p-hydroxyphenylthio) ethyl]-
N'-n-tetradecyl urea, N- [2- (p-hydroxyphenylthio) ethyl] -N'-n-octadecyl urea, N- [2- (3,4-dihydroxyphenylthio) ethyl] -N ' -N-octadecyl urea, N- [p
-(P-hydroxyphenylthio) phenyl] -N'-
n-octadecyl urea, N- [10- (p-hydroxyphenylthio) decyl] -N'-n-decyl urea, N-
[2- (p-hydroxyphenylthio) ethyl] -n-octadecylcarbamate, N- [p- (p-hydroxyphenylthio) phenyl] -n-dodecylcarbamate, Nn-octadecylcarbamic acid- [2 − (P−
Hydroxyphenylthio) ethyl], N- [3- (p-
(Hydroxyphenylthio) propionyl] -NN-octadecanoylamine, N- [2- (p-hydroxyphenylthio) aceto] -N'-n-octadecanohydrazide, N- [3- (p-hydroxy Phenylthio) propiono] -N'-n-octadecanohydrazide, N-
[3- (3,4-dihydroxyphenylthio) propiono] -N'-n-octadecanohydrazide, N- [6-
(P-Hydroxyphenylthio) hexano] -N'-n
-Tetradecanohydrazide, N- [6- (p-hydroxyphenylthio) hexano] -N'-n-octadecanohydrazide, N- [6- (p-hydroxyphenylthio) hexano] -N '-( pn-octylbenzo) hydrazide, N- [11- (p-hydroxyphenylthio) undecano-N'-n-decanohydrazide, N-
[11- (p-hydroxyphenylthio) undecano-
N'-n-tetradecanohydrazide, N- [11- (p
-Hydroxyphenylthio) undecano-N'-n-octadecanohydrazide, N- [11- (p-hydroxyphenylthio) undecano-N '-(6-phenyl) hexanohydrazide, N- [11- (3 , 4,5-Trihydroxyphenylthio) undecano] -N'-n-octadecanohydrazide, N- [p- (p-hydroxyphenylthio) benzo] -N'-n-octadecanohydrazide, N- [P- (p-hydroxyphenylthiomethyl)
Benzo] -N'-n-octadecanohydrazide, N-
[3- (p-hydroxyphenylthio) propyl] -N
'-N-octadecyloxamide, N- [3- (3,4
-Dihydroxyphenylthio) propyl] -N'-n-
Octadecyl oxamide, N- [11- (p-hydroxyphenylthio) undecyl] -N'-n-decyl oxamide, N- [p- (p-hydroxyphenylthio) phenyl] -N'-n-octadecyl oxamide, N-
[2- (p-hydroxyphenylthio) acetyl] -N
'-N-octadecyl urea, N- [3- (p-hydroxyphenylthio) propionyl] -N'-n-octadecyl urea, N- [2- (p-hydroxyphenylthio)
Ethyl] -N'-n-octadecanoyl urea, N- [p
-(P-hydroxyphenylthio) phenyl] -N'-
n-octadecanoyl urea, 3- [3- (p-hydroxyphenylthio) propionyl] carbazic acid-n-octadecyl, 4- [2- (p-hydroxyphenylthio) ethyl] -1-n-octadecyl semicarbazide,
1- [2- (p-hydroxyphenylthio) ethyl]-
4-n-octadecyl semicarbazide, 1- [p- (p
-Hydroxyphenylthio) phenyl] -4-n-tetradecylsemicarbazide, 1- [3- (p-hydroxyphenylthio) propionyl] -4-n-octadecylsemicarbazide, 1- [p- (p-hydroxyphenylthio) Benzoyl] -4-n-octadecyl semicarbazide, 4- [2- (p-hydroxyphenylthio) ethyl] -1-n-tetradecanoyl semicarbazide, 4-
[P- (p-hydroxyphenylthio) phenyl] -1
-N-octadecanoyl semicarbazide, 1- [2-
(P-Hydroxyphenylthio) acetamide] -1-
n-octadecanoylaminomethane, 1- [11- (p
-Hydroxyphenylthio) undecaneamide] -N '
-N-decanoylaminomethane, 1- [p- (p-hydroxyphenylthio) benzamide] -1-n-octadecanoylaminomethane, 1- [3- (p-hydroxyphenylthio) propanamide] -1 -(N'-n-octadecylureido) methane, 1- [11- (p-hydroxyphenylthio) undecanamido] -N '-(N
'-N-decylureido) methane, 1- {N'-[2-
(P-Hydroxyphenylthio) ethyl] ureido｝-
1-n-octadecanoylaminomethane, N- [2-
(P-hydroxyphenylthio) ethyl] -N'-n-
Octadecyl malonamide,

N- [2- (p-hydroxyphenyl) ethyl] -n-octadecylcarbamate, Nn-octadecylcarbamate- [2- (p-hydroxyphenyl) ethyl], N- [3- (p -Hydroxyphenyl)
Propionyl] -Nn-octadecanoylamine, N
-[6- (p-hydroxyphenyl) hexanoyl]-
N-n-octadecanoylamine, N- [3- (p-hydroxyphenyl) propionyl] -N- (pn-octylbenzoyl) amine, N- [2- (p-hydroxyphenyl) aceto] -N '-N-dodecanohydrazide, N- [2- (p-hydroxyphenyl) aceto]-
N'-n-octadecanohydrazide, N- [3- (p-
Hydroxyphenyl) propiono] -N'-n-octadecanohydrazide, N- [3- (p-hydroxyphenyl) propiono] -N'-n-docosanohydrazide, N
-[6- (p-hydroxyphenyl) hexano] -N '
-N-tetradecanohydrazide, N- [6- (p-hydroxyphenyl) hexano] -N'-n-octadecanohydrazide, N- [6- (p-hydroxyphenyl) hexano] -N '-( pn-octylbenzo) hydrazide, N- [11- (p-hydroxyphenyl) undecano-N'-n-decanohydrazide, N- [11- (p-
(Hydroxyphenyl) undecano-N′-n-octadecanohydrazide, N- (p-hydroxybenzo) -N ′
-N-octadecanohydrazide, N- [p- (p-hydroxyphenyl) benzo] -N'-n-octadecanohydrazide, N- [p- (p-hydroxyphenylmethyl) benzo] -N'- n-octadecanohydrazide, N
-[3- (p-hydroxyphenyl) propyl] -N '
-N-octadecyloxamide, N- [3- (3,4-
Dihydroxyphenyl) propyl] -N'-n-octadecyl oxamide, N- [p- (p-hydroxyphenyl) phenyl] -N'-n-octadecyl oxamide,
N- [2- (p-hydroxyphenyl) acetyl] -N
'-N-octadecyl urea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n-octadecyl urea,
N- [3- (p-hydroxyphenyl) propionyl]
-N'-n-octadecyl urea, N- [p- (p-hydroxyphenyl) benzoyl] -N'-n-octadecyl urea, N- [2- (p-hydroxyphenyl) ethyl] -N'-n- Octadecanoyl urea, 4- [2-
(P-hydroxyphenyl) ethyl] -1-n-octadecylsemicarbazide, 1- [2- (p-hydroxyphenyl) ethyl] -4-n-tetradecylsemicarbazide, 1- [2- (p-hydroxyphenyl) ethyl ]-
4-n-octadecyl semicarbazide, 1- [2- (p
-Hydroxyphenyl) acetyl] -4-n-tetradecyl semicarbazide, 1- [3- (p-hydroxyphenyl) propionyl] -4-n-octadecyl semicarbazide, 1- [11- (p-hydroxyphenyl) undecanoyl]- 4-n-decyl semicarbazide, 4-
[2- (p-hydroxyphenyl) ethyl] -1-n-
Octadedecanoyl semicarbazide, 4- [p- (p-
Hydroxyphenyl) phenyl] -1-n-octadecanoyl semicarbazide, 1- [2- (p-hydroxyphenyl) acetamido] -1-n-octadecanoylaminomethane, 1- [3- (p-hydroxyphenyl) Propanamide] -1-n-octadecanoylaminomethane, 1- [2- (p-hydroxyphenyl) acetamide] -1- (3-n-octadecylureido) methane,
1- [3- (p-hydroxyphenyl) propanamide] -1- (3-n-octadecylureido) methane,
1- [11- (p-hydroxyphenyl) undecanamido] -1- (3-n-decylureido) methane, 1-
{3- [2- (p-hydroxyphenyl) ethyl] ureide} -1-n-octadecanoylaminomethane, N-
[2- (p-hydroxyphenyl) ethyl] -N'-n
-Octadecylmalonamide,

4-n-octadecylaminophenol,
4- (1-octadecynyl) phenol, 4- (1,3
-Octadecadinyl) phenol and the like.

These may be used alone or in admixture of two or more, and usually 5 to 5000% by weight, preferably 10 to 3000% by weight, based on the colorless or light-colored electron-donating dye precursor. Used.

It is also possible to further use a binder for the purpose of improving the strength of the reversible thermosensitive recording layer. Specific examples of the binder include starches, hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, gelatin, casein, polyvinyl alcohol, modified polyvinyl alcohol, sodium polyacrylate, acrylamide / acrylate copolymer, acrylamide / acryl. Water-soluble polymers such as acid ester / methacrylic acid terpolymer, alkali salt of styrene / maleic anhydride copolymer, alkali salt of ethylene / maleic anhydride copolymer, polyvinyl acetate, polyurethane, polyacrylic acid Latexes such as esters, styrene / butadiene copolymers, acrylonitrile / butadiene copolymers, methyl acrylate / butadiene copolymers, ethylene / vinyl acetate copolymers, and the like, but are not limited thereto. No.

A heat-fusible substance can be contained in the reversible thermosensitive recording layer as an additive for adjusting the color development sensitivity and the decoloring temperature of the reversible thermosensitive recording layer. 60 ° C
Those having a melting point of ~ 200 ° C are preferable, and especially 80 ° C.
Those having a melting point of -180 ° C are preferred. A sensitizer used in general thermosensitive recording paper can also be used. For example, waxes such as N-hydroxymethylstearic acid amide, stearic acid amide and palmitic acid amide, naphthol derivatives such as 2-benzyloxynaphthalene, biphenyl derivatives such as p-benzylbiphenyl and 4-allyloxybiphenyl, 1,2. -Bis (3-
Polyether compounds such as methylphenoxy) ethane, 2,2'-bis (4-methoxyphenoxy) diethyl ether, bis (4-methoxyphenyl) ether, diphenyl carbonate, dibenzyl oxalate, bis (p-methylbenzyl) oxalate Carbonic acid or oxalic acid diester derivatives such as esters can be added in combination, but are not limited thereto.

The reversible thermosensitive recording material of the present invention repeatedly writes and erases an image by heating.
In order to prevent deterioration of the reversible thermosensitive recording layer, it is preferable to provide a protective layer on the reversible thermosensitive recording layer. As the material for forming the protective layer, water-soluble polymers, latexes,
There are polymerizable compounds and the like. For example, polyurethane resin, polyester resin, epoxy resin, melamine resin, polyvinyl alcohol, nitrocellulose, methacrylate, acrylate oligomer, acrylate oligomer and the like can be mentioned. If necessary, a crosslinking agent such as an epoxy compound, a urea derivative, or a vinyl compound, and a curing agent such as a phosphoric acid type, a sulfonic acid type, a polyamide type, and an amine type can be added. It is also possible to form a transparent film such as polyethylene or polyethylene terephthalate in advance, and form a protective layer on the reversible thermosensitive recording layer by a means such as bonding. In this case, an intermediate layer may be provided between the reversible thermosensitive recording layer and the protective layer if necessary. In this case, the protective layer or the intermediate layer may be composed of a plurality of layers of 2 layers or 3 layers or more. In addition, the reversible thermosensitive recording layer, protective layer or intermediate layer may include diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide, aluminum hydroxide, urea-formalin resin, etc. Other pigments, higher fatty acid metal salts such as zinc stearate and calcium stearate, paraffin,
Waxes such as oxidized paraffin, polyethylene, oxidized polyethylene, stearic acid amide, and castor wax may be added, and a dispersant such as sodium dioctylsulfosuccinate, a surfactant, and a fluorescent dye may be added.

As the support used in the reversible thermosensitive recording material of the present invention, paper, coated paper, various nonwoven fabrics, woven fabric, synthetic resin film, synthetic resin laminated paper, synthetic paper, metal foil, glass, etc. A composite sheet combining these can be used arbitrarily according to the purpose, and may be transparent, translucent, or opaque, but is not limited thereto. The thickness of the support is
The range is not particularly limited as long as it can withstand repeated use, but is 20 to 1300 μm, preferably 40 to 1000 μm.
m.

The constitution of the reversible thermosensitive recording material of the present invention is such that the reversible thermosensitive recording layer, another layer, the surface on which the reversible thermosensitive recording layer is provided or the surface on the opposite side are electrically and magnetically. Alternatively, a material capable of optically recording information may be included. Further, a back coat layer may be provided on the surface opposite to the surface on which the reversible thermosensitive recording layer is provided for the purpose of preventing curling and electrification, and may be further subjected to an adhesive process or the like.

The method for forming each layer constituting the reversible thermosensitive recording material of the present invention on a support is not particularly limited, and it can be formed by a conventional method. For example, a smearing device such as an air knife coater, a blade coater, a bar coater, and a carten coater, a planographic printing plate, a relief printing plate,
It is possible to use various printing machines using intaglio, flexo, gravure, screen, hot melt and the like. Furthermore, in addition to the usual drying process, each layer can be held by UV irradiation / EB irradiation. By these methods, smearing and printing can be performed one layer at a time or simultaneously at multiple layers.

In the reversible heat-sensitive recording material of the present invention, rapid cooling may be performed following heating to form a color-recorded image, and the cooling rate after heating may be reduced in order to erase the recorded image. Good if it is late. For example, after heating by an appropriate method, by rapidly cooling by pressing a low-temperature metal block or the like, a colored state can be developed. In addition, when a thermal head, a laser beam or the like is used for heating for an extremely short period of time, it is cooled immediately after the heating is completed, so that the coloring state can be maintained. On the other hand, when heated with an appropriate heat source (thermal head, laser light, heat roll, heat stamp, high frequency heating, radiant heat from a light source such as a tungsten lamp or halogen lamp, hot air, etc.) for a relatively long time, recording Since not only the layer but also the support and the like are heated, even if the heat source is removed, the cooling speed is slow and the state is decolorized. Therefore, even if the same heating temperature and / or the same heat source is used, the colored state and the decolored state can be arbitrarily expressed by controlling the cooling rate.

[0067]

The present invention will be described in more detail with reference to the following examples. Example 1 (A) Preparation of reversible heat-sensitive coating liquid 40 parts of 3-di-n-butylamino-6-methyl-7-anilinofluorane as a dye precursor and N- (4 as a reversible developer. -Hydroxyphenyl) -N'-octadecyl urea 100 parts by ball mill together with 910 parts of isopropyl alcohol solution of 8% polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd., BL-1, acetalization degree 63 mol%).
It was pulverized for an hour to prepare a reversible heat-sensitive coating liquid.

(B) Coating of reversible heat-sensitive recording layer The reversible heat-sensitive coating solution prepared in (A) was applied to a polyethylene terephthalate (PET) sheet as a support so that the solid content was 4 g / m ² . After being smeared, dried, and treated with a super calendar, a coated sheet was obtained.

(C) Coating of protective layer On the reversible thermosensitive layer of the coated sheet obtained in (B), 90 parts of Aronix M8030 (manufactured by Toagosei Chemical Industry Co., Ltd.), 5 parts of N-vinyl-2-pyrrolidone, Irgacure 500 (manufactured by Nippon Ciba Geigy) 5 parts and 10 parts of Nipseal E220A (manufactured by Nihon Silica) were added and stirred to prepare a coating liquid for the protective layer.
After coating so as to be 1 g / m ² , it was cured by an ultraviolet irradiation device to obtain a reversible thermosensitive recording material having a protective layer.

Example 2 In the preparation of the reversible heat-sensitive coating liquid (A) of Example 1, N-
(4-Hydroxyphenyl) -N'-octadecylurea was added to N- [2- (p-hydroxyphenyl) ethyl] -N.
Example 1 except for changing to'-n-octadecyl urea.
Same as.

Example 3 In the preparation of the reversible heat-sensitive coating liquid (A) of Example 1, N-
The same procedure as in Example 1 was carried out except that (4-hydroxyphenyl) -N'-octadecylurea was changed to N- (p-hydroxybenzo) -N'-n-octadecanohydrazide.

Example 4 In the preparation of the reversible heat-sensitive coating liquid (A) of Example 1, N-
As in Example 1, except that (4-hydroxyphenyl) -N'-n-octadecylurea was changed to N- [3- (p-hydroxyphenyl) propiono] -N'-n-octadecanohydrazide. did.

Example 5 In the preparation of the reversible heat-sensitive coating liquid (A) in Example 1, Coronate L (manufactured by Nippon Polyurethane Co., Ltd.) 29 was further added to the obtained reversible heat-sensitive coating liquid as an isocyanate compound.
Same as Example 1 except that parts were added.

Example 6 In the preparation of the reversible heat-sensitive coating liquid (A) of Example 1, 8% was used.
910 parts of an isopropyl alcohol solution of polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd., BL-1, acetalization degree: 63 mol%) and 600 parts of 8% polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd., KX-1, acetalization degree: 8 mol%) ,
Same as Example 1 except that 217 parts of water and 93 parts of isopropyl alcohol were used.

Example 7 In the preparation of the reversible heat-sensitive coating liquid (A) of Example 1, 8% was used.
910 parts of a polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd., BL-1, acetalization degree: 63 mol%) in isopropyl alcohol was used as a polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd.,
KS-1, acetalization degree of 70 mol% or more) 73 parts, ethanol 410 parts, toluene 427 parts, and Takenate D110N (manufactured by Takeda Pharmaceutical Co., Ltd.) as an isocyanate compound 14 parts were changed to the same as Example 1. .

Example 8 In the preparation of the reversible heat-sensitive coating liquid (A) of Example 1, 8%
910 parts of an isopropyl alcohol solution of polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd., BL-1, acetalization degree: 63 mol%) is an 18% aqueous polyvinyl acetal solution (manufactured by Sekisui Chemical Co., Ltd., KW-1, acetalization degree: 9 mol% or more).
Same as Example 1 except that 404 parts and 506 parts of methanol were changed.

Comparative Example 1 In the preparation of the reversible heat-sensitive coating liquid (A) of Example 1, 8%
910 parts of isopropyl alcohol solution of polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd., BL-1, acetalization degree: 63 mol%) is converted into 8% polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., NM-11, completely saponified type, polymerization degree: 1000 to
1500) 910 parts were changed to the same as Example 1.

Comparative Example 2 In the preparation of the reversible heat-sensitive coating liquid (A) of Example 1, 8%
910 parts of isopropyl alcohol solution of polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd., BL-1, acetalization degree: 63 mol%) was converted into 8% polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry, GL-05, partially saponified type, polymerization degree of 1000 or less). ) 910 parts, and (C) the coating of the protective layer, polyvinyl acetal (manufactured by Sekisui Chemical Co., Ltd., BM
-S, acetalization degree 70 mol% or more) 5 parts and Takenate D110N (manufactured by Takeda Pharmaceutical Co., Ltd.) as an isocyanate compound 1.5 parts, mono-n-dodecyl sodium phosphate monophosphate (lubricant) 1 part, toluene 45 parts, methyl ethyl ketone The same procedure as in Example 1 was carried out except that 50 parts of the mixture was mixed to form a coating liquid for the protective layer, and the coating amount of the solid content was 1 g / m ² .

The following evaluation tests were carried out on the reversible thermosensitive recording material produced as described above. Test method The reversible thermosensitive recording materials obtained in Examples and Comparative Examples were applied with an application pulse of 1.1 msec using a thermal facsimile printing tester TH-PMD manufactured by Okura Electric Co. with a print head KJT-256-8MGF1 manufactured by Kyocera. Printed under the condition of voltage of 26 V, and the obtained color image is densitometer Macbeth RD918
Was measured as a color density. The obtained colored image portion was heated at 120 ° C. for 1 second using a heat stamp to erase the color, and then the density was measured in the same manner to obtain the erased density.

Further, the above-mentioned color development and decolorization were repeated 100 times, and the color development density and decolorization density at the 100th time were measured, and the surface of the recording surface was observed and evaluated according to the following criteria. ：: good, no damage on the recording surface. ：: Slight print flaws are observed on the recording surface, but there is no practical problem. ×: Destruction of the recording surface print layer is observed.

After immersing the obtained reversible thermosensitive recording material in water for 100 hours, the recording surface was immediately rubbed with a finger, and the surface was observed. The water resistance was evaluated according to the following criteria. ：: No damage on the recording surface was observed, and it was good. ×: Destruction of the recording surface print layer is observed.

[0082]

[Table 1]

From Table 1, Example 1 in which the reversible color developer was changed
Nos. 4 to 4 show good color development and decolorization even after repeated use, high durability, and sufficient water resistance, indicating that the present invention is not affected by the type of reversible developer. In addition, Examples 5 and 7 using an isocyanate compound in the reversible thermosensitive recording layer are particularly resistant to repeated use, and no reduction in print density is observed, so it can be understood that they are very excellent. Similarly, Examples 6 and 8 show good coloring and decoloring,
It was possible to repeatedly perform color development and decolorization, and the water resistance was sufficient. In Comparative Examples 1 and 2, a sufficient color density was obtained. However, when color development and color erasing were repeated, a decrease in color density and an increase in erase density were observed, and the image contrast was significantly reduced. Regarding the water resistance, peeling of the recording layer on the printed surface was observed after immersion in water, and not only the protective layer but also the reversible thermosensitive recording layer needs to have sufficient water resistance. From this, a clear difference is observed between the example and the comparative example, and it is confirmed that the present invention has a great effect.

[0084]

INDUSTRIAL APPLICABILITY The reversible thermosensitive recording material of the present invention can be colored by heat energy of a thermal head or the like, and can be changed to a decolored state by heating the composition in the colored state again. Further, such coloring and erasing can be repeated, and the coloring and erasing states can be maintained at room temperature. Further, in the reversible thermosensitive recording material of the present invention, by containing the polyvinyl acetal resin in the reversible thermosensitive recording layer, there is little damage even by repeated use of coloring and decoloring, and moreover, it is satisfactory in practical use with strong water resistance. It can be used as a reversible heat-sensitive recording material capable of producing.

Claims (3)

[Claims] 1. A support comprising, on at least one surface of a support, an usually colorless to light-colored electron-donating dye precursor and a reversible developer that develops the dye precursor by heating and reheats it to decolorize it. A reversible heat-sensitive recording material having a reversible heat-sensitive recording layer, wherein the reversible heat-sensitive recording layer contains a polyvinyl acetal resin. 2. The reversible thermosensitive recording material according to claim 1, wherein the polyvinyl acetal resin in the reversible thermosensitive recording layer is crosslinked with a di- or tri- or more isocyanate compound. 3. The reversible color developer is dispersed and pulverized in a mixed medium of water and alcohol.
The reversible thermosensitive recording material as described above.