JP2003246145A - Reversible heat-sensitive recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reversible heat-sensitive recording material capable of stably repeatedly forming and erasing an image having a clear contrast 1,000 times or more with high sensitivity. <P>SOLUTION: The reversible heat-sensitive recording material contains the normally colorless or pale leuco dye, a reversible developer for color developing the leuco dye by heating and reheating to achromatize the leuco dye, and a phthalocyanine compound having a vanadyl group. <P>COPYRIGHT: (C)2003,JPO

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 whose color tone changes reversibly by controlling thermal energy.

[0002]

2. Description of the Related Art In recent years, reversible thermosensitive recording materials have been attracting attention because they can form temporary images and can erase the images when they are no longer needed. Typical examples thereof are Japanese Patent Laid-Open No. 6-210954 and Japanese Patent Laid-Open No. 6-210954.
No. 171225, JP-A-7-68933, JP-A-7-68934 and the like, which are usually colorless or light-colored leuco dye, and this leuco dye is colored by heating, and this is reheated. A reversible thermosensitive recording material using a reversible color developing agent for decoloring is known.

However, in such a conventional reversible thermosensitive recording material, when recording and erasing of an image by heating are repeated,
In particular, when a thermal head is used, the surface is rubbed while being heated, so that the surface of the recording layer is scratched, and if it becomes severe, a uniform image cannot be recorded. On the other hand, in JP-A-6-344673 and JP-A-8-156410, a protective layer is provided on the surface of such a reversible thermosensitive recording material to reduce scratches on the surface of the recording layer when a thermal head is used. Is proposed. However, if the conventional reversible thermosensitive recording material is provided with a protective layer, it may be difficult to say that the scratch resistance is sufficient when the number of recording and erasing increases. In addition, when recording and erasing are repeated by a method in which heat and pressure are applied to the reversible thermosensitive recording layer at the same time as in a thermal head, the reversible thermosensitive recording layer is subjected to temperature and pressure to elute the reversible thermochromic composition. However, there was a problem that the layer was destroyed and the recording density was lowered.

As a method for reducing the deterioration due to such a thermal head, Japanese Patent Laid-Open Nos. 57-82088 and 64-14077 disclose resin base materials such as vinyl chloride-vinyl acetate copolymer. In a reversible heat-sensitive recording material in which an organic low-molecular substance such as a higher fatty acid is dispersed, a method of incorporating carbon black or an infrared absorbing dye and recording with a laser beam is disclosed.
According to this method, non-contact printing is possible, but since the image is a so-called cloudy type formed by light scattering,
The contrast was low and the visibility was poor.

On the other hand, in JP-A-5-8537 and JP-A-11-151856, various photothermal conversion materials using a leuco dye and a reversible developer as a reversible thermosensitive recording material are disclosed. A system for recording with a near-infrared laser beam in combination with the above has been proposed. This system certainly gives a clear image contrast,
The formation and erasing of a highly sensitive image and the repeatability of 1000 times or more, which are important problems in practical use, have not been verified. In fact, according to an additional test by the present inventors, when a metal vapor deposition film such as Cr is used as a photothermal conversion material, it is not possible to selectively give a high absorbance in accordance with the wavelength of the near infrared laser light. Therefore, the recording sensitivity is low. In addition, JP-A-11-151
The layer structure disclosed in Japanese Patent No. 856 is not sufficient in terms of recording sensitivity. In the example of the publication, after the printing and the erasing are repeated 100 times, the recording surface is observed and there is no unevenness in the recording state and the erasing state. The above repeatability has not been verified or guaranteed at all. In the first place, the technology that uses a photothermal conversion dye to convert the energy of near-infrared laser light into heat for recording is the CD-R
Studies have been concentrated on write-once type recording materials such as those described above, and recordings for rewriting many times rely mainly on inorganic materials. Under the present circumstances, no technical guideline is given at all for enabling the photothermal conversion dye to be repeated a large number of times, such as 1000 times or more, by a near infrared laser beam.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to obtain an image having clear contrast with high sensitivity and 1000
An object of the present invention is to provide a reversible thermosensitive recording material which can be repeatedly formed and erased repeatedly over a number of times.

[0007]

Means for Solving the Problems As a result of studies to solve these problems, the present inventors have found that normally a colorless or light-colored leuco dye, which is colored by heating and then reheated to be erased. It has been found that a reversible thermosensitive recording material containing a reversible color developer and a phthalocyanine compound having a vanadyl group can solve the above problems.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, there is provided a reversible thermosensitive recording material capable of stably forming and erasing an image having a clear contrast with high sensitivity and over a large number of times of 1000 times or more. Provided.

A reversible heat-sensitive recording material which records and erases an image by repeating 1000 times or more with a near infrared laser beam using a photothermal conversion dye is required to have high heat resistance and laser light resistance. The present inventors have examined the heat resistance and laser light resistance characteristics of the constituent elements of the present recording material, and as a result, the laser light resistance characteristics of the photothermal conversion dye are the most important factors for recording and erasing many times. I found that. If the laser light resistance of the photothermal conversion dye is low, the dye deteriorates at a small number of repetitions, the efficiency of converting the laser light into heat decreases, and it becomes impossible to record or erase an image. Such properties of photothermal conversion dyes have never been measured previously. Light resistance to sunlight and fluorescent lamps involves the reaction of dyes in the excited state with triplet oxygen and the generation and reaction of singlet oxygen, so it is reasonable to use it as data to predict laser light resistance characteristics. Lack sex. Therefore, the present inventors have diligently studied a technique for enabling a large number of repetitions of 1000 times or more with a near-infrared laser beam using a photothermal conversion dye, and as a result, have a vanadyl group as a photothermal conversion dye. It was found that the problem of the present invention can be solved by containing a phthalocyanine compound. Further, it has been found that the leuco dye, the reversible color developer, and the phthalocyanine compound having a vanadyl group are present in the same layer, whereby good contrast can be obtained with high sensitivity.

The phthalocyanine compound having a vanadyl group according to the present invention also includes naphthalocyanine. The phthalocyanine compound may have a substituent on the aromatic ring for the purpose of adjusting the absorption wavelength, improving the solubility in a solvent, improving the light resistance and the like. As the substituent, an alkyl group, an acyl group,
Acyloxy group, aryl group, alkylamino group, arylamino group, arylcarbonylamino group, alkyl ether group, alkylthioether group, arylether group, arylthioether group, amide group, amino group,
Alkyl ester group, aryl ester group, chlorine atom,
Examples thereof include a fluorine atom, a cyano group, a nitro group, a sulfonyl group, a sulfonic acid group, a pyridyl group and an aminocarbonyl group. When the aromatic ring has two or more substituents, they may be the same or different, and the substituents may be bonded to each other to form a ring.

Particularly, when the near-infrared absorbing dye is contained in the same layer as the leuco dye and the reversible developer, solubility or dispersibility in an organic solvent is desired, and therefore, an alkyl group, an alkyl ether group, an alkyl thioether. Group, an aryl ether group, or an aryl thioether group, which is 4 kinds of substituents.
Phthalocyanine compounds having three or more are preferred. As the alkyl group, a linear or branched alkyl group having 4 to 12 carbon atoms is preferable. Further, by having an amide group, an amino group, a nitro group, a chlorine atom, a fluorine atom or the like as a substituent, it is possible to adjust the absorption wavelength and improve light resistance.

Specific examples of the phthalocyanine compound having a vanadyl group include vanadyl phthalocyanine and vanadyl 2,9,16,23-tetra-t-butyl-29.
H, 31H-phthalocyanine, vanadyl 2,9,16,
23-tetraacetyl-29H, 31H-phthalocyanine, vanadyl 2,9,16,23-tetrachloro-29
H, 31H-phthalocyanine, vanadyl 2,9,16,
23-Tetrafluoro-29H, 31H-phthalocyanine, vanadyl 2,9,16,23-tetranitro-29
H, 31H-phthalocyanine, vanadyl 2,9,16,
23-Tetraphenoxy-29H, 31H-phthalocyanine, vanadyl 2,9,16,23-tetraphenoxycarbonyl-29H, 31H-phthalocyanine, vanadyl 2,9,16,23-acetyloxy-29H, 31
H-phthalocyanine, vanadyl 2,9,16,23-acetylamino-29H, 31H-phthalocyanine, vanadyl 2,9,16,23-tetraphenylthio-29
H, 31H-phthalocyanine, vanadyl 2,9,16,
23- (4-pyridylmethoxy) -29H, 31H-phthalocyanine, vanadyl 2,3,9,10,16,1
7,23,24-Octakis (octyloxy) -29
H, 31H-phthalocyanine, vanadyl 2,11,2
0,29-tetra-t-butyl-2,3-naphthalocyanine, vanadyl 3,10,17,24-tetra-t-butyl-1,8,15,22-tetrakis (dimethylamino) -29H, 31H- Phthalocyanine, vanadyl 5,
14,23,32-Tetraphenyl-2,3-naphthalocyanine, vanadyl 5,9,14,18,23,27,
32,36-octabutoxy-2,3-naphthalocyanine, vanadyl 5,9,14,18,23,27,32,
36-octabutylthio-2,3-naphthalocyanine,
Vanadyl phthalocyanine tetrasulfonic acid tetrasodium salt, vanadyl tetrakis (4-cumylphenoxy)
Examples thereof include phthalocyanine, but are not limited thereto.

If the amount of the photothermal conversion dye having a slight absorption in the visible region is used too much, the contrast is lowered. Therefore, it is preferable to set the amount of the photothermal conversion dye used so that an average transmittance of 400 nm to 700 nm of 60% or more can be secured. Further, two or more kinds of photothermal conversion dyes can be mixed and used.

The photothermal conversion dye is preferably contained in at least one of the same layer and an adjacent layer with respect to the layer containing the leuco dye and the reversible developer, and it is contained in the same layer. Is more preferable for obtaining good sensitivity.

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

3-diethylamino-7-o-chlorophenylaminofluorane, 3-diethylamino-7-m-
Chlorophenylaminofluorane, 3-diethylamino-7-p-chlorophenylaminofluorane, 3-diethylamino-7-o-fluorophenylaminofluorane, 3-diethylamino-7-m-fluorophenylaminofluorane, 3-diethylamino- 7-p-fluorophenylaminofluorane, 3-di-n-butylamino-7-m-chlorophenylaminofluorane, 3-di-n-butylamino-7-p-chlorophenylaminofluorane, 3-di- n-butylamino-7-o-fluorophenylaminofluorane, 3-di-n-butylamino-7-m-fluorophenylaminofluorane, 3-
Di-n-butylamino-7-p-fluorophenylaminofluorane,

3-diethylamino-6-methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-o-chlorophenylaminofluorane, 3-
Diethylamino-6-methyl-7-m-chlorophenylaminofluorane, 3-diethylamino-6-methyl-
7-p-chlorophenylaminofluorane, 3-diethylamino-6-methyl-7-o-fluorophenylaminofluorane, 3-diethylamino-6-methyl-7-
o-Tolylaminofluorane, 3-diethylamino-6
-Methyl-7-m-tolylaminofluorane, 3-diethylamino-6-methyl-7-p-tolylaminofluorane, 3-diethylamino-6-methyl-7-o-trifluoromethylphenylaminofluorane, 3 -Diethylamino-6-methyl-7-m-trifluoromethylphenylaminofluorane, 3-diethylamino-6-methyl-7-p-acetylphenylaminofluorane, 3
-Diethylamino-6-methoxy-7-phenylaminofluorane, 3-diethylamino-6-ethoxy-7-
Phenylaminofluorane,

3-di-n-butylamino-6-methyl-
7-phenylaminofluorane, 3-di-n-butylamino-6-methyl-7-o-tolylaminofluorane,
3-di-n-butylamino-6-methyl-7-m-tolylaminofluorane, 3-di-n-butylamino-6-
Methyl-7-p-tolylaminofluorane, 3-di-n
-Butylamino-6-methyl-7-o-chlorophenylaminofluorane, 3-di-n-butylamino-6-methyl-7-m-chlorophenylaminofluorane, 3-
Di-n-butylamino-6-methyl-7-p-chlorophenylaminofluorane, 3-di-n-butylamino-
6-methyl-7-o-fluorophenylaminofluorane, 3-di-n-butylamino-6-methyl-7-m-
Fluorophenylaminofluorane, 3-di-n-butylamino-6-methyl-7-p-fluorophenylaminofluorane, 3-di-n-butylamino-6-methyl-7-o-trifluoromethylphenyl Aminofluorane, 3-di-n-butylamino-6-methyl-7-m-
Trifluoromethylphenylaminofluorane, 3-di-n-butylamino-6-methyl-7-p-trifluoromethylphenylaminofluorane, 3-di-n-butylamino-6-methoxy-7-phenylamino Fluorane, 3-di-n-butylamino-6-ethoxy-7-phenylaminofluorane,

3-di-n-pentylamino-6-methyl-7-phenylaminofluorane, 3-di-n-pentylamino-6-methyl-7-m-trifluoromethylphenylaminofluorane, 3- Pyrrolidyl-6-methyl-7-phenylaminofluorane, 3-piperidyl-6
-Methyl-7-phenylaminofluorane, 3-N-methyl-N-isopentylamino-6-methyl-7-phenylaminofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7- Phenylaminofluorane, 3-N-methyl-N-n-butylamino-6-methyl-7-phenylaminofluorane, 3-N-methyl-N-n-propylamino-6-methyl-7-phenylamino Fluorane, 3-N-ethyl-N-isopentylamino-6-methyl-7-phenylaminofluorane,
3-N-ethyl-N-isopentylamino-6-methyl-7-o-chlorophenylaminofluorane, 3-N-
Ethyl-N-p-tolylamino-6-methyl-7-phenylaminofluorane, 3-N-ethyl-N- (4-ethoxybutyl) amino-6-methyl-7-phenylaminofluorane, 3-diethylamino- 7-dibenzylaminofluorane, 3-diethylamino-7-octylaminofluorane, 3-diethylamino-7-phenylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-chloro-7-methyl Fluorane, 3-diethylamino-7- (3,4-dichloroanilino) fluorane, 3-diethylamino-7- (2
-Chloroanilino) fluoran,

3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), 3,3-bis (p-dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) ) -3- (1,2-Dimethylindol-3-yl)
Phthalide, 3- (p-dimethylaminophenyl) -3-
(2-Methylindol-3-yl) phthalide, 3-
(P-Dimethylaminophenyl) -3- (2-phenylindol-3-yl) phthalide, 3,3-bis (1,
2-Dimethylindol-3-yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindol-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,

3- (2-Ethoxy-4-aminophenyl) -3- (1-ethyl-2-methylindole-3-
Yl) -4-azaphthalide, 3- (2-ethoxy-4-)
Methylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3-
(2-Ethoxy-4-ethylaminophenyl) -3-
(1-Ethyl-2-methylindol-3-yl) -4
-Azaphthalide, 3- (2-ethoxy-4-propylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-hexylaminophenyl) ) -3- (1-Ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-dimethylaminophenyl) -3- (1-ethyl-2-methylindole-3) −
Yl) -4-azaphthalide, 3- (2-ethoxy-4-)
Diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3-
(2-Ethoxy-4-dipropylaminophenyl) -3
-(1-Ethyl-2-methylindol-3-yl)-
4-azaphthalide, 3- (2-ethoxy-4-dihexylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-
Ethoxy-4-phenylaminophenyl) -3- (1-
Ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-pyridylphenyl) -3- (1-ethyl-2-methylindol-3-
Yl) -4-azaphthalide, 3- (3-ethoxy-4-)
Diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide,

3- (2-methyl-4-diethylaminophenyl) -3- (1-ethyl-2-methylindole-
3-yl) -4-azaphthalide, 3- (2-ethyl-4)
-Diethylaminophenyl) -3- (1-ethyl-2-
Methylindol-3-yl) -4-azaphthalide, 3
-(2-propyl-4-diethylaminophenyl) -3
-(1-Ethyl-2-methylindol-3-yl)-
4-Azaphthalide, 3- (2-butyl-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-pentyl-4-diethylaminophenyl) -3- (1-Ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-hexyl-4-diethylaminophenyl) -3- (1-ethyl-2-methylindole-3-
Yl) -4-azaphthalide, 3- (2-cyclohexyl-4-diethylaminophenyl) -3- (1-ethyl-
2-Methylindol-3-yl) -4-azaphthalide, 3- (2-cyano-4-diethylaminophenyl)
-3- (1-Ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-nitro-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) ) -4-Azaphthalide, 3- (2
-Chloro-4-diethylaminophenyl) -3- (1-
Ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-bromo-4-diethylaminophenyl) -3- (1-ethyl-2-methylindole-3
-Yl) -4-azaphthalide, 3- (2-methyl-4-)
Diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3-
(2-Ethoxy-4-diethylaminophenyl) -3-
(2-Methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-methyl-2-methylindol-3-
Yl) -4-azaphthalide, 3- (2-ethoxy-4-)
Diethylaminophenyl) -3- (1-propyl-2-
Methylindol-3-yl) -4-azaphthalide, 3
-(2-Ethoxy-4-diethylaminophenyl) -3
-(1-Butyl-2-methylindol-3-yl)-
4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-pentyl-2-methylindol-3-yl) -4-azaphthalide,

3- (2-Ethoxy-4-diethylaminophenyl) -3- (1-hexyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl)- 3- (1-heptyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-octyl-2-methylindole-3
-Yl) -4-azaphthalide, 3- (2-ethoxy-4)
-Diethylaminophenyl) -3- (1-nonyl-2-
Methylindol-3-yl) -4-azaphthalide, 3
-(2-Ethoxy-4-diethylaminophenyl) -3
-(1-Isopropyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-isobutyl-2-
Methylindol-3-yl) -4-azaphthalide, 3
-(2-Ethoxy-4-diethylaminophenyl) -3
-(1-Isopentyl-2-methylindol-3-yl) -4-azaphthalide,

3- (2-Ethoxy-4-diethylaminophenyl) -3- (1-methyl-2-ethylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl)- 3- (1-ethyl-
2-Propylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-butylindol-3-
Yl) -4-azaphthalide, 3- (2-ethoxy-4-)
Diethylaminophenyl) -3- (1-ethyl-2-pentylindol-3-yl) -4-azaphthalide, 3
-(2-Ethoxy-4-diethylaminophenyl) -3
-(1-Ethyl-2-hexylindol-3-yl)
-4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-isopropylindol-3-yl) -4-azaphthalide, 3-
(2-Ethoxy-4-diethylaminophenyl) -3-
(1-Ethyl-2-isobutylindol-3-yl)
-4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4-azaphthalide,

4,4'-bis (dimethylaminophenyl) benzhydryl benzyl ether, N-chlorophenyl leuco auramine, N-2,4,5-trichlorophenyl leuco auramine, benzoyl leuco methylene blue, p-nitrobenzoyl leuco Methylene blue, 3
-Methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3,3'-dichlorospirodinaphthopyran, 3-benzylspirodinaphthopyran, 3-methylnaphtho- (3-methoxybenzo) spiropyran, 3-propylspiro Examples thereof include benzopyran.

The above leuco dyes may be used either individually or in combination of two or more. In addition, toning can be performed by mixing a leuco dye that develops another hue.

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

[0028]

[Chemical 1]

In the compound represented by the general formula (1), X ¹ and X ² may be the same or different and each does not contain an oxygen atom, a sulfur atom or a hydrocarbon group at both ends. -Represents a divalent group having a bond as a minimum structural unit. R ¹ represents a single bond or a divalent hydrocarbon group having 1 to 12 carbon atoms. R ² represents a divalent hydrocarbon group having 1 to 18 carbon atoms. Preferred is a divalent hydrocarbon group having 1 to 4 carbon atoms. R ³ represents a monovalent hydrocarbon group having 1 to 24 carbon atoms, preferably a hydrocarbon group having 6 to 24 carbon atoms, and more preferably a hydrocarbon group having 8 to 24 carbon atoms. Furthermore, the sum of carbon numbers of R ¹ , R ² and R ³ is 11 or more and 3
The case of 5 or less is particularly preferable. R ¹ , R ² and R ³ mainly represent an alkylene group and an alkyl group, respectively. R
^In the case of ¹ , it may contain an aromatic ring. f is 0 to 4
R ² and X ^{2 which} are repeated when f is 2 or more may be the same or different.

X ¹ and X ² in the general formula (1) include a divalent group having a minimum constitutional unit of -CONH- bond which does not contain a hydrocarbon atom group at both ends. Diacylamine (-CONHCO-), diacylhydrazine (-CONHNHCO-), oxalic acid diamide (-NH
COCONH-), acyl urea (-CONHCONH
-, -NHCONHCO-), semicarbazide (-NH
CONHNH-, -NHNHCONH-), acyl semicarbazide (-CONHNHCONH-, -NHCON)
HNHCO-), diacylaminomethane (-CONHC
H ₂ NHCO -), 1- acylamino-1- Ureidometan (-CONHCH ₂ NHCONH -, - NHCON
HCH ₂ NHCO-), malonamide (-NHCOCH
₂ CONH-), 3-acylcarbazic acid ester (-
Examples thereof include groups such as CONHNHCOO- and -OCONHNHCO-, but diacylhydrazine, oxalic acid diamide, and acyl semicarbazide are preferable.

Specific examples of the reversible color developer according to the present invention include the following structural formulas (1-1) to (1-1)
However, the present invention is not limited to this.

[0032]

[Chemical 2]

[0033]

[Chemical 3]

The reversible color developer according to the present invention is 1
One kind or a mixture of two or more kinds may be used, and the amount used is usually 5 to 5,000 with respect to a colorless or pale leuco dye.
It is mass%, preferably 10 to 3000 mass%.

Next, a specific method for producing the reversible thermosensitive recording material of the present invention will be described, but the present invention is not limited thereto.

As a specific example of the method for producing the reversible thermosensitive recording material of the present invention, a colorless or light-colored leuco dye, a reversible developer and a photothermal conversion dye are usually used as main components, and these are coated on a support or Examples thereof include a method of printing to form a reversible thermosensitive recording layer.

Usually, a colorless or light-colored leuco dye, a reversible developer, and a photothermal conversion dye are contained in the reversible thermosensitive recording layer by dissolving each compound alone in a solvent or dispersing it in a dispersion medium. A method of mixing, a method of dissolving each compound in a solvent or dispersing in a dispersion medium, mixing each compound by heating to dissolve and homogenize, and then cooling.
A layer can be formed by preparing a mixed solution by a method of dissolving it in a solvent or dispersing it in a dispersion medium, and coating or printing it on a support and then drying it.

When the photothermal conversion dye is contained in a layer different from the leuco dye and the reversible developer, the photothermal conversion dye is dispersed singly or together with a binder in a layer adjacent to the layer containing the reversible developer. It is preferable to contain

Further, a binder may be added to the reversible thermosensitive recording layer for the purpose of improving the strength of the reversible thermosensitive recording layer. Specific examples of the binder include starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, polyvinyl alcohol, modified polyvinyl alcohol, sodium polyacrylate, acrylic acid amide / acrylic acid ester copolymer, acrylic acid amide / acrylic. Acid ester / methacrylic acid terpolymer, alkali salt of styrene / maleic anhydride copolymer, alkali salt of ethylene / maleic anhydride copolymer, polyvinyl acetate, polyurethane, polyacrylic ester, styrene / butadiene copolymer Polymer, acrylonitrile / butadiene copolymer,
Methyl acrylate / butadiene copolymer, ethylene / vinyl acetate copolymer, ethylene / vinyl chloride copolymer, polyvinyl chloride, ethylene / vinylidene chloride copolymer, polyvinylidene chloride, polycarbonate, polyvinyl butyral and the like can be mentioned. The role of these binders is
The purpose is to keep each material of the composition uniformly dispersed by applying heat for printing and erasing without deviation. Therefore, it is preferable to use a resin having high heat resistance as the binder resin. Recently, high value-added reversible thermosensitive recording materials such as prepaid cards and stored cards are often used, and along with this, high durability products such as heat resistance, water resistance, and adhesiveness are required. Is becoming. Curable resins are particularly preferable for such requirements.

Examples of the curable resin include a thermosetting resin, an electron beam curing resin, an ultraviolet curing resin and the like.
As the thermosetting resin, for example, phenoxy resin, polyvinyl butyral resin, cellulose acetate propionate resin and the like, which are cured by reacting a hydroxyl group and a carboxyl group with a crosslinking agent, can be mentioned. Examples of the crosslinking agent at this time include isocyanates, amines, phenols, epoxies and the like.

Monomers used for electron beam and ultraviolet ray curable resins include monofunctional monomers, difunctional monomers and polyfunctional monomers typified by acrylic resins, and especially photopolymerization initiation in the case of ultraviolet ray crosslinking. Agents and photopolymerization accelerators are used.

For the purpose of preventing aging of the reversible thermosensitive recording material, an antioxidant used in rubber products and the like can be added. Further, an antioxidant may be contained in the upper layer or the lower layer of the reversible thermosensitive recording layer. For the purpose of preventing the deterioration of the photothermal conversion dye due to ultraviolet rays, an antiaging agent may be contained in the layer containing the photothermal conversion dye or the upper layer of the layer containing the photothermal conversion dye. Antiaging agents include p, p'-diaminodiphenylmethane, aldol-α-naphthylamine, N, N'-diphenyl-
Examples thereof include amine compounds such as p-phenylenediamine, hydroquinone monobenzyl ether, phenol compounds such as 1,1-bis (p-hydroxyphenyl) cyclohexane, benzotriazole compounds, triazine compounds, benzophenone compounds and benzoate compounds. Other examples include o-phenylene thiourea, zinc salt of 2-aminobenzimidazole, nickel dibutylthiocarbamate, zinc oxide, paraffin and the like. Further, a polymer containing such a monomer having an antioxidant structure as one component of polymerization, or a polymer having a polymer main chain grafted with an antioxidant structure can also be used. It is also possible to use two or more anti-aging agents in combination.

A heat-fusible substance may be contained in the reversible thermosensitive recording layer as an additive for controlling the color developing 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. It is also possible to use a sensitizer which is used for general thermal recording paper. 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, and the like. -Polyether compounds such as -bis (3-methylphenoxy) ethane, 2,2'-bis (4-methoxyphenoxy) diethyl ether, bis (4-methoxyphenyl) ether, diphenyl carbonate, dibenzyl oxalate, bis (oxalate) Carbonic acid such as p-methylbenzyl) ester or an oxalic acid diester derivative or the like can be added in combination.

The support used in the reversible thermosensitive recording material of the present invention is paper, various non-woven fabrics, woven fabrics, synthetic resin films, synthetic resin laminated papers, synthetic papers, metal foils, glass, or a combination thereof. The composite sheet can be arbitrarily used according to the purpose, and may be transparent, translucent or opaque. Moreover, it is not limited to these.

The layer constitution of the reversible thermosensitive recording material of the present invention is as follows:
An intermediate layer may be provided between the reversible thermosensitive recording layer and the support. In this case, the protective layer and the intermediate layer may be composed of a plurality of layers of 2 layers or 3 layers or more. Further, in the reversible thermosensitive recording layer, a material capable of electrically, magnetically and optically recording information may be contained in another layer, a surface on which the reversible thermosensitive recording layer is provided or an opposite surface. . Also, curling is prevented on the surface opposite to the surface on which the reversible thermosensitive recording layer is provided,
A back coat layer may be provided for the purpose of antistatic.

For the reversible thermosensitive recording layer, protective layer and intermediate layer, diatomaceous earth, talc, kaolin, calcined kaolin,
Pigments such as calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide, aluminum hydroxide, and urea-formalin resin, as well as higher fatty acid metal salts such as zinc stearate and calcium stearate, paraffin, paraffin oxide, polyethylene, Waxes such as oxidized polyethylene, stearic acid amide, and castor wax, dispersants such as sodium dioctylsulfosuccinate, surfactants, fluorescent dyes, and the like can be included.

[0047]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition, the number of copies in the examples is based on mass.

Example 1 3-Diethylamino-6-methyl-7-m-trifluoromethylphenylaminofluorane (Yamada Chemical Co., Ltd.)
Manufactured by BLACK 100) 20 parts, N- [3- (p-hydroxyphenyl) propiono] -N'-n-docosanohydrazide 100 parts, polyester polyol (Dainippon Ink and Chemicals, Inc., Vernock D-293). -7
0) 50 parts, curing agent (Nippon Polyurethane Co., Ltd., Coronate HL) 50 parts, methyl ethyl ketone 300 parts, toluene 300 parts vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine 1 part (manufactured by Aldrich) was added, and the mixture was pulverized with glass beads for 5 hours on a paint shaker to obtain a dispersion liquid. A polyethylene terephthalate (PET) sheet was coated with the above dispersion so that the solid content was 7 g / m ^2, and dried to obtain a reversible thermosensitive recording material.

[Print Erasing Test] The reversible thermosensitive recording material of Example 1 was subjected to color development using a semiconductor laser having a wavelength of 830 nm under a temperature condition of 25 ° C. ± 1 ° C., and the density of the color development part was measured by Macbeth RD918. I asked.
Next, the color-developed portion is irradiated with laser light having the energy to erase the color-developed portion, and the density of the color-developed portion is changed to Macbeth
918, and the unerased portion and the coloring (erasing fog) caused by a laser at the time of erasing were visually confirmed at the erasing portion. The difference between the coloring density and the erasing density (first contrast) was 0.55. Coloring and erasing were repeated by the same operation, and the contrasts at the 200th and 1000th times were determined to be 0.53 and 0.52, respectively.

Example 2 Vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was converted to vanadyl 3,10,17,24-tetra-t-butyl-1. , 8,
15,22-tetrakis (dimethylamino) -29H,
A reversible thermosensitive recording material of Example 2 was obtained in the same manner as in Example 1 except that 31H-phthalocyanine was used.

Example 3 The vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was converted to vanadyl 2,9,26,23-tetraphenoxy-29H, 31.
A reversible thermosensitive recording material of Example 3 was obtained in the same manner as in Example 1 except that H-phthalocyanine was used.

Example 4 The vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was converted to vanadyl 5,14,23,32-tetraphenyl-2,3-. A reversible thermosensitive recording material of Example 4 was obtained in the same manner as in Example 1 except that naphthalocyanine was used.

Example 5 The vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was converted to vanadyl 5,9,14,18,23,27,32,36. A reversible thermosensitive recording material of Example 5 was obtained in the same manner as in Example 1 except that it was changed to octabutoxy-2,3-naphthalocyanine.

Example 6 Vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was converted to vanadyl 2,11,20,29-tetra-t-amylthio-2. ，
A reversible thermosensitive recording material of Example 6 was obtained in the same manner as in Example 1 except that 3-naphthalocyanine was used.

Example 7 The vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was converted to vanadyl 2,11,20,29-tetranitro-5,9,14. ，
18,23,27,32,36-octabutoxy-2,
A reversible thermosensitive recording material of Example 7 was obtained in the same manner as in Example 1 except that 3-naphthalocyanine was used.

Comparative Example 1 Vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was converted to tin (I
I) A reversible thermosensitive recording material of Comparative Example 1 was obtained in the same manner as in Example 1 except that 2,3-naphthalocyanine dichloride was used.

Comparative Example 2 The vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was changed to silicon 2,3-naphthalocyanine-bis (trihexylsiloxide). Comparative Example 2 as in Example 1 except that
A reversible thermosensitive recording material of was obtained.

Comparative Example 3 Vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was changed to silicon 2,3-naphthalocyanine-di-octyl oxide. In the same manner as in Example 1, a reversible thermosensitive recording material of Comparative Example 3 was obtained.

Comparative Example 4 Vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was converted to zinc 2,11,20,29-tetra-t-butyl-2. , 3-
A reversible thermosensitive recording material of Comparative Example 4 was obtained in the same manner as in Example 1 except that naphthalocyanine was used.

Comparative Example 5 Vanadyl 2,11,20,29-tetra-t-butyl-2,3-naphthalocyanine used in Example 1 was replaced with cobalt 2,11,20,29-tetra-t-butyl-2. , 3-
A reversible thermosensitive recording material of Comparative Example 5 was obtained in the same manner as in Example 1 except that naphthalocyanine was used.

[Evaluation] With respect to Examples 2 to 7 and Comparative Examples 1 to 5, repeated tests were carried out in the same manner as in Example 1, and the visual evaluation of the erased portion was as follows: complete erasure was ○, unerased residue was Δ, and erase fog was observed. It was set to x. Regarding the value of contrast, 0.6 or more is ⊚, 0.4 or more and less than 0.6 is ◯, 0.3 or more and less than 0.4 is Δ, and less than 0.3 is x. It shows in Table 1.

[0062]

[Table 1]

As is clear from the results shown in Table 1, the samples of Examples containing the phthalocyanine compound having a vanadyl group showed clear contrast even after printing was repeated 1000 times.

[0064]

INDUSTRIAL APPLICABILITY According to the present invention, a reversible thermosensitive recording material can be obtained which is capable of forming and erasing an image having a clear contrast stably and repeatedly over 1000 times or more. .

Claims (3)

[Claims] 1. A colorless or pale leuco dye, a reversible developer that develops the leuco dye by heating and reheats it to decolorize it, and a phthalocyanine compound having a vanadyl group. Reversible thermosensitive recording material. 2. A leuco dye, a reversible color developer, and a phthalocyanine compound having a vanadyl group are in the same layer.
The reversible thermosensitive recording material according to claim 1. 3. The phthalocyanine compound having a vanadyl group is at least any one of an alkyl group, a substituent having an ether bond and a substituent having a thioether bond.
The reversible thermosensitive recording material according to claim 1, which has at least four kinds of substituents.