JPH09290570A - Thermal recording material for infrared laser - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide an infrared absorbing dye having a light color and a high infrared absorbing efficiency, and to provide a heat sensitive recording material for a laser having high heat sensitivity. A heat-sensitive recording material for infrared laser, comprising at least an infrared absorbing dye represented by the general formula [1] on a support. Embedded image (In the general formula [1], R ¹ and R ² may be the same or different from each other and represent an alkyl group, an alkenyl group and an aralkyl group which may have a substituent.
¹ and Y ² may be the same as or different from each other, and at least one of them is a group of non-metal atoms necessary for forming a cyclic hydrocarbon together with the carbon atom at the 3-position of the nitrogen-containing ring. One or more may be substituted with heteroatoms.
Z ¹ and Z ² may be the same or different from each other,
It represents a group of atoms necessary for forming a substituted or unsubstituted benzene ring or naphthalene ring. L ^{1 to} L ³ represent an unsubstituted or substituted methine group, and m is 2 or 3.
X represents an anion, and n represents a number required to adjust the intramolecular charge to zero. )

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material, and more particularly to a heat-sensitive recording material for a laser for converting light energy of a laser into heat energy for recording.

[0002]

2. Description of the Related Art A heat-sensitive recording material generally comprises a support and a heat-sensitive recording layer containing an electron-donating, usually colorless or light-colored dye precursor and an electron-accepting developer as main components.
By heating with a thermal head, a heating pen, a laser beam or the like, the colorless dye precursor and the developer react instantaneously to obtain a recorded image. JP-B-43-4160 and JP-B-4
It is disclosed in JP-A-5-14039.

Such a heat-sensitive recording material is advantageous in that recording can be obtained by a relatively simple apparatus using a thermal head, maintenance is easy, and noise is not generated. It is used in a wide range of fields such as facsimiles, printers, computer terminals, labels, ticket vending machines, etc.

However, when the thermal head is used, it is necessary to closely contact the thermal recording material with the thermal head for scanning, the thermal head is worn, and the components of the thermal recording material become dust on the surface of the thermal head. Since they adhere, defects such as chipped recorded images tend to occur. Also,
Thermal recording using such a thermal head is limited in response to heating and cooling of the heating element and element density due to structural restrictions of the heating element, and high speed recording and high resolution recording. Furthermore, since the thermal head closely scans, a large pressure is applied to the heat-sensitive layer of the recording material, and in order to alleviate this, pigments and lubricants that do not directly contribute to image formation are added, limiting the degree of freedom in designing the heat-sensitive layer. There was a limit to the resolution of the material itself.

When the light energy of laser light is converted into heat energy and used, heat can be applied to the heat-sensitive layer without contacting the heat-sensitive layer directly, and the degree of freedom in designing the heat-sensitive layer increases. At the same time, high-speed recording and high-density recording become possible, and many proposals have been made so far (for example, Japanese Patent Laid-Open Nos. 50-23617 and 54-54).
121140, 57-11090, 58-56
890, 58-94494, 58-13479.
No. 1, 58-145493, 59-89192 and 62-56195). However, since the heat-sensitive layer generally has a small absorption of laser light, an effort has been made to increase the thermal sensitivity by adding a suitable laser light absorbing substance. Conventionally, carbon black has been used as such a substance, but the visible region is strongly colored and can only be used for the transfer system.

When a laser having an oscillation wavelength in the near infrared region is used as a laser and an infrared absorbing dye transparent to visible light is used as a substance that absorbs laser light and converts light energy into heat energy, It is preferable that the recorded image can be used as a reflection image or a transmission image. As such an infrared absorbing dye, cyanine disclosed in JP-A-5-116450, JP-A-5-124338, JP-A-5-124339, JP-A-5-124340 and JP-A-7-32739 is disclosed. Dyes, phthalocyanine dyes, pyrylium / thiapyrylium dyes, azulene dyes, squarylium dyes described in JP-A-7-25153, metal complex salt dyes of Ni, Cr, etc., indophenol dyes, naphthoquinone dyes Examples include dyes, anthraquinone dyes, indophenol dyes, indoaniline dyes, triphenylmethane dyes, triallylmethane dyes, aminium dyes, diimonium dyes, and nitroso compounds. It is the current situation that there is no dye having a small size and a high heat conversion efficiency.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to develop an infrared absorbing dye having a small visible region coloring and a high heat conversion efficiency, and to obtain a heat-sensitive recording material for laser which can be recorded in a non-contact manner.

[0008]

The present inventors have found that a cyanine dye having a spiro ring has a small absorption in the visible region, is light in color, and is excellent in heat conversion efficiency, and has achieved the above object.

That is, the present invention is a heat-sensitive recording material for infrared laser which is characterized by containing at least an infrared absorbing dye represented by the general formula [1] on a support.

[0010]

Embedded image

In the general formula [1], R ¹ and R ² may be the same or different and each represents an alkyl group, an alkenyl group or an aralkyl group. Y ¹ and Y ² may be the same or different from each other, and at least one of them is a group of non-metal atoms necessary for forming a cyclic hydrocarbon together with the carbon atom at the 3-position of the nitrogen-containing ring, and is a carbon atom. One or more of may be substituted with heteroatoms. Z ¹ and Z ² may be the same as or different from each other, and represent an atomic group necessary for forming a substituted or unsubstituted benzene ring or naphthalene ring. L ^{1 to} L ³ represent an unsubstituted or substituted methine group, and m is 2 or 3. X represents an anion, and n represents a number required to adjust the intramolecular charge to zero.

Next, the thermal recording material of the present invention will be described in more detail. In the present invention, the infrared absorbing dye present in the vicinity of the image forming component converts the light energy of laser light into heat energy, and the heat causes the image forming component to develop or decolor to form an image. The infrared absorbing dye may be contained in the same layer as the image forming layer, or a layer provided in the vicinity of the layer containing the image forming component (for example, an adjacent layer)
You may contain in it. Therefore, the image forming component can be applied to all image forming materials used in heat-sensitive recording materials, including known transfer systems.

The infrared absorbing dye used in the present invention is a compound represented by the above general formula [1]. Specifically, in the general formula [1], R ₁ and R ₂ are each an alkyl group which may have a substituent (for example, a methyl group, an ethyl group, n-
Propyl group, isopropyl group, n-butyl group, n-pentyl group etc.) or alkenyl group (eg allyl group, methallyl group etc.) or aralkyl group (eg benzyl group, β-phenylethyl group, α-naphthylmethyl group) etc)
Can be mentioned. Specific examples of the substituent include a sulfonic acid group, a carboxyl group, a phosphonic acid group, a hydroxy group, a halogen atom, an alkoxy group and a cyano group. When the substituent is an acid substituent, N
It may be in the form of an alkali metal salt such as a and K, an alkaline earth metal salt such as Mg and Ca, an ammonium salt, a triethylammonium salt, a tributylammonium salt, and an organic ammonium salt such as a pyridinium salt.

The hydrocarbon rings formed together with the carbon atom at the 3-position of the nitrogen-containing ring represented by Y ¹ and Y ² may be the same or different, and are preferably 4- to 7-membered hydrocarbon rings,
Specific examples of the hydrocarbon ring include a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring and the like. Further, one or more carbon atoms of the hydrocarbon ring may be substituted with a hetero atom, and a specific example thereof is a tetrahydropyran ring.
The hydrocarbon ring of Y ¹ and Y ² may have a substituent, and specific examples of the substituent include a lower alkyl group such as a methyl group and an ethyl group.

Z ¹ and Z ² may be the same or different and each represents an atomic group necessary for forming a benzene ring or a naphthalene ring. Z ¹ and Z ² may have a substituent, and specific examples of the substituent include a sulfonic acid group, a carboxyl group, an alkyl group, an aralkyl group, an aryl group, a halogen atom, a cyano group, a nitro group, an alkoxy group, Examples thereof include a hydroxy group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonamide group and a carboxamide group. When the substituent is an acid substituent, Na,
It may be in the form of an alkali metal salt such as K, an alkaline earth metal salt such as Mg or Ca, an organic ammonium salt such as an ammonium salt, a triethylammonium salt, a tributylammonium salt or a pyridinium salt.

L ^{1 to} L ³ represent an unsubstituted or substituted methine group, and specific examples of the substituent include a halogen atom, a hydroxy group, a carboxyl group, an alkyl group, an aralkyl group, an aryl group, an alkoxy group and an alkoxycarbonyl. Group, carbamoyl group, sulfamoyl group, sulfonamide group, carboxamide group and the like. Further, the substituents may combine with each other to form a 6-membered ring containing three methine groups, such as a 4,4-dimethylcyclohexane ring. Further, m indicating the length of the methine chain is 2 or 3, and more preferably 3.

As the anion represented by X, a halogen ion, a perchlorate ion, an arylsulfonate ion,
Alkyl sulfate ions and the like can be mentioned. here,
n is 1 or 2, and is 1 when the dye forms an inner salt.

Specific examples of the compound represented by the above general formula [1] are shown below, but the present invention is not limited thereto.

[0019]

Embedded image

[0020]

Embedded image

[0021]

Embedded image

[0022]

[Chemical 6]

[0023]

Embedded image

[0024]

Embedded image

[0025]

Embedded image

[0026]

Embedded image

[0027]

Embedded image

[0028]

[Chemical 12]

[0029]

Embedded image

[0030]

Embedded image

[0031]

Embedded image

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

[0035]

Embedded image

[0036]

Embedded image

[0037]

[Chemical 21]

[0038]

Embedded image

[0039]

Embedded image

[0040]

Embedded image

[0041]

Embedded image

[0042]

Embedded image

[0043]

Embedded image

[0044]

Embedded image

[0045]

Embedded image

[0046]

Embedded image

[0047]

Embedded image

The dye compound in the present invention is surprising in its remarkable light-absorbing density as compared with the conventionally known simple polymethinecyanine dyes, and by introducing a spiro ring into the ring, an Indian compound having no spiro ring can be obtained. It will be apparent from the examples described later that the heat conversion performance is superior to that of the cyanine dye, and that the coloring in the visible portion is small and the color is light.

Regarding the method for synthesizing the compounds effective in the present invention, JP-A-2-1877751 and JP-A-2-2239 are available.
No. 44 and Japanese Patent Application Laid-Open No. 3-95548.

The amount of the infrared absorbing dye added is not particularly limited, but the larger the absorption density of the coating layer, the larger the amount of heat that is generally generated. Therefore, the absorption density is 2 or more at the wavelength of the laser light used. Preferably. Naturally, it is preferable that the maximum absorption wavelength (λmax) of the infrared absorbing dye to be used is close to the wavelength of the laser beam because the addition amount can be reduced. Further, in order to efficiently utilize the heat generated, it is preferable that the above-mentioned absorption concentration is achieved in a thin layer as much as possible. The existing form thereof may be any of a dispersion of dye, inclusion in microcapsules, and uniform dissolution in a binder. The content is suitably 0.05 to 1.0 g / m ² .

Next, as a coloring component, in the case of a positive type which develops a color in a heated portion, a coloring reaction between an electron-donating dye precursor and a color developer and a coloring reaction between a photodegradable diazo compound and a coupler are used. And a method utilizing a color reaction of an imino compound and an isocyanate (JP-A-3-150).
No. 190) and the like, and in the case of a negative type which is used by decolorizing the heating part, a method of decoloring by applying a decolorizing agent to the above-mentioned electron-donating dye precursor and the color former or dye of the developer Is available. Here, a heat-sensitive recording material utilizing a color-developing reaction between an electron-donating dye precursor and a color developer will be described as an example.

The electron-donating, usually colorless or light-colored 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, for example, the following, but the present invention is not limited thereto.

Examples of the triarylmethane compound and the indolylphthalide compound are 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone) and 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- (2- Methyl-4-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-ethylcarbazole-3
-Yl) -5-dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) -5-dimethylaminophthalide, 3-p-dimethylaminophenyl-3
-(1-Methylpyrrol-2-yl) -6-dimethylaminophthalide, 3- (1-ethyl-2-methylindol-3-yl) -3- (4-dimethylamino-2-ethoxyphenyl)- 4-azaphthalide, 3- (1-ethyl-2-methylindol-3-yl) -3- (4-dimethylamino-2-ethoxyphenyl) -7-azaphthalide, 3- (1-ethyl-2-methylindole) -3-yl) -3- (4-dimethylamino-2-ethoxyphenyl) -4,7-diazaphthalide, 3,3-bis (4-diethylamino-2-ethoxyphenyl) -4-azaphthalide, 3- (4 -Diethylamino-2-ethoxyphenyl) -3- (4-N-phenyl-N-ethylamino-2
-Ethoxyphenyl) -4-azaphthalide and the like,

As the diphenylmethane compound, 4,
4'-bis (dimethylaminophenyl) benzhydryl benzyl ether, N-chlorophenylleuco auramine, N-2,4,5-trichlorophenyl leuco auramine, etc.

Examples of fluoran compounds and xanthene compounds are 3-diethylamino-6-methyl-7-anilinofluorane and 3-piperidino-6-methyl-7-.
Anilinofluorane, 3-pyrrolidino-6-methyl-7
-Anilinofluoran, 3-diethylamino-6-methyl-7- (4-methylanilino) fluoran, 3-diethylamino-6-methyl-7- (4-n-butylanilino) fluoran, 3-diethylamino-6-methyl- 7
-(4-ethoxyanilino) fluoran, 3-pyrrolidino-6-methyl-7- (4-methylanilino) fluoran, 3-pyrrolidino-6-methyl-7- (4-n-butylanilino) fluoran, 3-pyrrolidino- 6-methyl-7- (4-ethoxyanilino) fluoran, 3-di-
n-propylamino-6-methyl-7-anilinofluoran, 3-di-n-butylamino-6-methyl-7-anilinofluoran, 3-di-n-pentylamino-6-
Methyl-7-anilinofluoran, 3- (N-methyl-
N-n-propyl) amino-6-methyl-7-anilinofluoran, 3- (N-ethyl-Nn-propyl) amino-6-methyl-7-anilinofluoran, 3- (N
-Ethyl-N-isoamyl) amino-6-methyl-7-
Anilinofluorane, 3- (N-ethyl-N-amyl)
Amino-6-methyl-7-anilinofluoran, 3-
(N-ethyl-N-isobutyl) amino-6-methyl-
7-anilinofluorane, 3- (N-methyl-N-cyclohexyl) amino-6-methyl-7-anilinofluorane, 3- (N-methyl-N-tetrahydrofuran-2
-Ylmethyl) amino-6-methyl-7-anilinofluorane, 3- (N-ethyl-N-tetrahydrofurylmethyl) amino-6-methyl-7-anilinofluorane,
3- (N-methyl-N-tetrahydrofuran-2-yl) amino-6-methyl-7-anilinofluorane, 3
-(N-ethyl-N-tetrahydrofuryl) amino-6
-Methyl-7-anilinofluorane, 3-dimethylamino-6-methyl-7-anilinofluorane, 3- (N-
Methyl-N-ethyl) amino-6-methyl-7-anilinofluorane, 3-isopentylamino-6-methyl-
7-anilino fluoran,

3-di-n-butylamino-6-methyl-
7- (2-fluoroanilino) fluoran, 3-dibutylamino-6-methoxy-7-anilinofluoran, 3
-Di-n-butylamino-6-methyl-7- (2,6-
Dimethylanilino) fluoran, 3- (N-ethyl-N
-3-Ethoxypropyl) amino-6-methyl-7-anilinofluorane, 3- (N-methyl-N-3-ethoxypropyl) amino-6-methyl-7-anilinofluorane, 3-diethylamino- 6-methyl-7- (3-trifluoromethylanilino) fluorane, 3-diethylamino-7- (3-trifluoromethylanilino) fluorane, 3-diethylamino-7- (2-chloroanilino) fluorane, 3-diethylamino -7- (3-chloroanilino) fluorane, 3-di-n-butylamino-
7- (3-chloroanilino) fluorane, 3-diethylamino-7- (2-fluoroanilino) fluorane, 3
-Diethylamino-7- (2-methoxyanilino) fluorane, 3-pyrrolidino-7- (2-chloroanilino)
Fluoran, 3-pyrrolidino-7- (3-chloroanilino) fluorane, 3-pyrrolidino-7- (2-methoxyanilino) fluorane, 3-diethylamino-7- (2
-Isopentyloxycarbonylanilino) fluorane, 3- (N-ethyl-Np-tolyl) amino-6-
Methyl-7-anilinofluorane, 3-pyrrolidino-7
-Cyclohexylaminofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-n-octylaminofluorane, 3-diethylamino-7-phenylfluorane, 3-diethylamino-7-chlorofluorane , 3-diethylamino-6-
Chloro-7-methylfluorane, 3-diethylamino-
6-methyl-7-chlorofluorane, 3-di-n-butylamino-6-methyl-7-chlorofluorane, 3-diethylamino-7- (3,4-dichloroanilino) fluorane, 3-ethylamino -6-chlorofluorane, 3
-Cyclohexylamino-6-chlorofluoran, 3-
Diethylamino-7,8-benzofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-di-n-butylamino-7- (2-chlorobenzylamino) fluorane, 3,6-dimethoxyfluorane, Three
6-diethoxyfluorane, rhodamine B anilinolactam, rhodamine B-p-chloroanilinolactam, etc.

Other examples include thiazine compounds such as benzoyl leuco methylene blue and p-nitrobenzoyl leuco methylene blue, 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3,3'-dichlorospirodinaphthopyran, 3-benzylspirodinaphthopyran, 3-methylnaphtho- (3-methoxybenzo)
Spiropyran compounds such as spiropyran and 3-propylspirobenzopyran, and 3 ', 6'-bisdiethylamino-5-diethylaminospiro (isobenzofuran-1,
Compounds having a fluorene skeleton such as 9'-fluoren) -3-one, 3 ', 6'-bisdimethylamino-5-dimethylaminospiro (isobenzofuran-1,9'-fluoren) -3-one, 3-bis- [2- (4-methoxyphenyl) -2- (4-dimethylaminophenyl)
Examples thereof include vinylogous triarylmethane compounds such as ethenyl] -4,5,6,7-tetrachlorophthalide, and these dye precursors can be used alone or in combination of two or more.

The electron-accepting developer is represented by an acidic substance generally used for pressure-sensitive recording paper, heat-sensitive recording paper and the like, but is not particularly limited. For example, polyvalent metal salts such as phenol derivatives, aromatic carboxylic acid derivatives, N, N'-diarylthiourea derivatives, and zinc salts of organic compounds can be used.

As the phenol derivative, specifically,
p-phenylphenol, p-hydroxyacetophenone, 4-hydroxy-4'-methyldiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-4'-benzenesulfonyloxydiphenylsulfone, 1,1- Bis (p-hydroxyphenyl) propane, 1,1-bis (p-hydroxyphenyl) pentane, 1,1-bis (p-hydroxyphenyl) hexane, 1,1-bis (p-hydroxyphenyl) cyclohexane, 2, 2-bis (p-hydroxyphenyl) propane, 2,2-bis (p-hydroxyphenyl) hexane, 1,1-bis (p-hydroxyphenyl) -2-ethylhexane, 2,2-bis (3-chloro) -4-hydroxyphenyl) propane, 1,1-bis (p-hydroxy) Eniru) -1-phenylethane,
1,3-di- [2- (p-hydroxyphenyl) -2-
Propyl] benzene, 1,3-di- [2- (3,4-dihydroxyphenyl) -2-propyl] benzene,
4-di- [2- (p-hydroxyphenyl) -2-propyl] benzene,

4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, 3,
3'-dichloro-4,4'-dihydroxydiphenyl sulfone, 3,3'-diallyl-4,4'-dihydroxydiphenyl sulfone, 3,3'-dichloro-4,4'-
Dihydroxydiphenyl sulfide, 2,2-bis (4
-Hydroxyphenyl) methyl acetate, 2,2-bis (4
-Hydroxyphenyl) butyl acetate, 4,4'-thiobis (2-t-butyl-5-methylphenol), 2,
2'-bis (4-hydroxyphenylthio) diethyl ether, 1,7-di (4-hydroxyphenylthio)-
3,5-Dioxaheptane, benzyl p-hydroxybenzoate, chlorobenzyl p-hydroxybenzoate, 4-
Dimethyl hydroxyphthalate, benzyl gallate, stearyl gallate, 5,5'-benzylidene bis- (1,
3-diethyl-thiobarbituric acid), salicylanilide, 5-chlorosalicylanilide and the like. Two or more kinds of these color developers may be used in combination.

Usually, the coating amount of each component of the heat-sensitive recording layer mainly composed of a colorless or pale color dye precursor and a color developer is 0.1 to 3.0 g / m ² as the dye coating amount. Although suitable, 0.50 to 2.0 g / m ² is particularly preferable because a high color density can be obtained. Further, the amount of the developer developer smeared is appropriately 5 to 400% by weight with respect to the dye precursor, and particularly preferably 20 to 300% by weight.

The heat-sensitive recording material of the present invention may contain a heat-fusible substance, if necessary, in order to improve the heat response of each heat-sensitive recording layer. In this case, 60
Those having a melting point of ℃ to 180 ℃ are preferable, and especially 8
Those having a melting point of 0 ° C to 140 ° C are more preferable.

Specific examples of the heat-fusible substance (sensitizer) for improving the thermal response are N-.
Waxes such as hydroxymethylstearic acid amide, stearic acid amide, palmitic acid amide, oleic acid amide, ethylene bisstearic acid amide, ricinoleic acid amide, paraffin wax, microcrystalline wax, polyethylene wax, rice wax, carnauba wax, Naphthol derivatives such as -benzyloxynaphthalene, p-benzylbiphenyl,
Biphenyl derivatives such as 4-allyloxybiphenyl,
1,2-bis (3-methylphenoxy) ethane, 2,
Polyether compounds such as 2'-bis (4-methoxyphenoxy) diethyl ether and bis (4-methoxyphenyl) ether, diphenyl carbonate, dibenzyl oxalate,
Examples thereof include carbonic acid or oxalic acid diester derivatives such as oxalic acid di (p-chlorobenzyl) ester.

These sensitizers can be used alone or in combination of two or more kinds. Further, in order to obtain sufficient thermal response, 20 to 400% by weight of the colorless dye precursor is used.
Preferably, it is used.

Next, the negative type thermal recording material will be described.
The electron-donating dye precursor and the color developer are melted by heating, dissolved in an organic solvent, or dissolved in an organic solvent and then the solvent is removed to form a color-developing body. Such a coloring material is finely pulverized and dispersed in water together with the binder polymer, or a solution obtained by emulsifying and dispersing a solution dissolved in an organic solvent in water together with a surfactant is applied to the film to form a colored film. be able to. Also, a colored film can be obtained by directly applying a solution dissolved in an organic solvent to the film. This coloring can be thermally eliminated by adding a decoloring agent.

In the present invention, the decoloring agent is not particularly limited as long as it is a compound capable of decoloring a color former formed by the reaction between an electron-donating, usually colorless or pale color dye precursor and an electron-accepting color developing agent. The following compounds can be specifically mentioned. 1,3-dicyclohexyl-2-phenylguanidine, 1,3-dicyclohexyl-2-
Guanidines such as (2,5-dimethylphenyl) guanidine, 1,3-di-orthotolylguanidine, 1,2,3-triphenylguanidine and 1,3-diphenylguanidine, 1,2,3,4-butane Tetrakis tetracarboxylic acid (1,2,2,6,6-pentamethyl-4-piperidyl), Tetrakis 1,2,3,4-butane tetracarboxylic acid (2,2,6,6-tetramethyl-4-piperidyl) ), 1,8-octanedicarboxylic acid bis (1,2 ,,
2,6,6-pentamethyl-4-piperidyl), 1,8
-Piperidines such as bis (2,2,6,6-tetramethyl-4-piperidyl) octanedicarboxylate, tetrakis (1-methyl-4-piperidyl) 1,2,3,4-butanetetracarboxylic acid, N , N'-diphenylformamidine, N, N'-bis (2-methylphenyl) formamidine, N, N'-diphenylbenzamidine, N,
Amidines such as N′-bis (4-methylphenyl) -N′-phenylbenzamidine, N, N′-isophthaloyl-di (N-cyclohexyl-N-methylamide),
Aromatic dicarboxylic acid diamides such as N, N′-terephthaloyl-di (N-phenyl-N-ethylamide), 4,
Morpholines such as 4'-dithiodimorpholine, N, N '
-Piperazines such as distearoyl piperazine.

The decoloring agent may be present in a position capable of decoloring the above-mentioned color developing material, and may be contained in the same layer as the color developing material or in a layer adjacent to the color developing material layer. It can also be encapsulated in microcapsules. The addition amount varies depending on the alkali strength and the existing form of the decoloring agent, and the necessary amount may be appropriately determined experimentally, but is usually about 0.2 to 3 times the weight of the color developing agent.

In the recording layer constituting the heat-sensitive recording material of the present invention, various additives can be used in order to improve the fog resistance of the uncolored portion and the thermal response. For example, N-stearyl-N ′-(2-hydroxyphenyl) urea,
N-stearyl-N '-(3-hydroxyphenyl) urea, N-stearyl-N'-(4-hydroxyphenyl) urea, p-stearoylaminophenol, o-
Stearoylaminophenol, p-lauroylaminophenol, p-butyrylaminophenol, m-acetylaminophenol, o-acetylaminophenol, p-acetylaminophenol, o-butylaminocarbonylphenol, o-stearylaminocarbonylphenol, p -Stearylaminocarbonylphenol, 1,1,3-tris (3-tert.-butyl-)
4-hydroxy-6-methylphenyl) butane, 1,
1,3-tris (3-tert.-butyl-4-hydroxy-6-ethylphenyl) butane, 1,1,3-tris (3,5-di-tert.-butyl-4-hydroxyphenyl) butane, 1,1,3-Tris (3-ter
t. -Butyl-4-hydroxy-6-methylphenyl)
Propane, 1,2,3-tris (3-tert.-butyl-4-hydroxy-6-methylphenyl) butane,
1,1,3-tris (3-phenyl-4-hydroxyphenyl) butane, 1,1,3-tris (3-cyclohexyl-4-hydroxy-5-methylphenyl) butane,
1,1,3-tris (3-cyclohexyl-4-hydroxy-6-methylphenyl) butane, 1,1,3,3-
Tetra (3-phenyl-4-hydroxyphenyl) propane, 1,1,3,3-tetra (3-cyclohexyl-
4-hydroxy-6-methylphenyl) propane, 1,
1-bis (3-tert.-butyl-4-hydroxy-
It is possible to add compounds such as 6-methylphenyl) butane and 1,1-bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) butane.

In addition, a pigment may be used in the heat-sensitive recording layer, if necessary. As the pigment, for example, diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide, aluminum hydroxide, barium sulfate, inorganic pigments such as colloidal silica, also urea-formalin resin, Organic pigments such as polyethylene particles, nylon particles, styrene particles and starch particles can be mentioned. Further, if necessary, a lubricant, an ultraviolet absorber, a surfactant, a fluorescent dye, etc. may be added.

In the heat-sensitive recording layer constituting the heat-sensitive recording material of the present invention, an electron-donating, usually colorless or pale-colored dye precursor,
As a method of incorporating an electron-accepting color developer, a decoloring agent, a laser light absorbing material, or the like, a method of dissolving or emulsifying / dispersing each compound alone in water or an organic solvent,
Obtained by a method in which each compound is mixed and then dissolved or emulsified / dispersed in water or an organic solvent, or a method in which each compound is heated and dissolved to homogenize and then cooled, and then dissolved or emulsified / dispersed in water or an organic solvent. There is a method of mixing each of the obtained solutions or dispersions, printing on a support, and coating and drying. When emulsified and dispersed in water or an organic solvent, it is necessary that the dispersed particles have an average particle size of 10 μm or less, preferably 5 μm or less, more preferably 2 μm or less. If necessary, the microcapsules can be encapsulated individually or in a mixture. Further, the recording layer can be formed by mixing the microcapsules individually encapsulated.

A binder is appropriately added to each of the above-mentioned components used in the heat-sensitive recording material of the present invention, and the binder is coated on the support. As the binder, when the above constituents are dispersed in water to produce a recording material as an aqueous coating liquid, starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, polyvinyl alcohol, modified polyvinyl alcohol, polyacryl. Acid soda, acrylamide / acrylic acid ester copolymer, acrylamide / acrylic acid ester / methacrylic acid terpolymer, alkali salt of styrene / maleic anhydride copolymer, alkali salt of ethylene / maleic anhydride copolymer, etc. And a latex-based water-insoluble binder such as a styrene / butadiene copolymer, an acrylonitrile / butadiene copolymer, or a methyl acrylate / butadiene copolymer can be used. Further, when the electron donating dye precursor and the color developer are dissolved in an organic solvent to form a colored layer, or when the laser light absorbing dye is dissolved in an organic solvent to form a laser light absorbing layer, an organic solvent is used. It is possible to use various organic solvent-soluble polymers such as various binders soluble in water, for example, polyvinyl butyral, polyvinyl acetate, polyacrylic acid ester and the like.

As the support of the heat-sensitive recording material of the present invention,
Paper, coated paper, various non-woven fabrics, woven fabrics, synthetic resin films, synthetic resin laminated papers, synthetic papers, metal foils, glass, etc., or a composite sheet in which these are combined can be arbitrarily used according to the purpose. Further, it may be transparent, semi-transparent or opaque, and is not limited to these. In the case of being transparent or semi-transparent, laser light can be irradiated from the support side, which is more preferable. The thickness of the support is not particularly limited because it depends on the application, but is 20 to 4000 μm, preferably 40 to 3000 μm.
m.

In the heat-sensitive recording material of the present invention, a protective layer is preferably provided on the uppermost heat-sensitive recording layer in order to prevent deterioration of each heat-sensitive recording layer. Further, an intermediate layer may be provided between the heat-sensitive recording layer and the support and / or between the heat-sensitive recording layer and the protective layer. Further, information is electrically, magnetically or optically provided on each or part of the heat-sensitive recording layer and / or on the surface on which the other layer and / or the heat-sensitive recording layer is provided and / or on the opposite surface. A recordable material may be included. In addition, a back coat layer may be provided on the surface opposite to the surface on which the heat-sensitive recording layer is provided for the purpose of preventing curling and electrification, and may be subjected to adhesive processing or the like.

As the material for forming the protective layer used in the heat-sensitive recording material of the present invention, water-soluble polymers, latexes,
There are polymerizable compounds and the like. For example, polyurethane resins, polyester resins, epoxy resins, melamine resins, polyvinyl alcohol, nitrocellulose, methacrylates, acrylic oligomers, acrylic ester oligomers 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 uppermost heat-sensitive recording layer by a means such as bonding. In this case, if necessary, an intermediate layer can be provided between the heat sensitive recording layer and the protective layer.

In order to improve the printability and sensitivity of the heat-sensitive recording material of the present invention, a heat insulating layer may be provided on the support.
It is desired that the heat insulating layer contains air having a large heat insulating effect efficiently and has smoothness. This heat-insulating layer can be obtained, for example, by providing various hollow particles, air capsules containing air therein, inorganic and organic pigments having a large number of pores, a binder and the like as main components on a support. In order to obtain the effect of the heat insulating layer, the smear amount is preferably 0.5 to 30 g / m ² . Below this range, the effect of improving the sensitivity is not sufficient, and above this range, it may be difficult to obtain a uniform smooth surface.

The method for forming each layer constituting the heat-sensitive recording material of the present invention on the support is not particularly limited,
It can be formed by a conventional method. For example, air knife coater, blade coater, bar coater,
A smearing device such as a curtain coater, and various printing machines using a method such as lithographic, letterpress, intaglio, flexo, gravure, screen, and hot melt can be used. 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.

[0077]

EXAMPLES The present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the examples,
All parts and percentages are by weight.

Example 1 The following lower layer coating liquid and upper layer coating liquid were applied to a 100 μ thick transparent polyethylene terephthalate (P
ET) film was sequentially laminated to obtain a heat-sensitive recording material for infrared laser. Lower layer coating liquid 18 0.5 parts Polyvinyl butyral 3% dichloromethane solution 50 parts Upper layer coating liquid The following liquids A and B were separately dispersed in a ball mill for 2 days, and then the ratio of A: B = 1: 2. The mixture was stirred and mixed so as to obtain a coating liquid. Liquid A 3-diethylamino-6-methyl-7-anilinofluorane 1 part 5% aqueous solution of hydroxyethyl cellulose 6 parts Liquid B 4,4'-isopropylidenediphenol 1 part 5% aqueous solution of hydroxyethyl cellulose 6 parts

Comparative Example 1 Similar to Example 1 except that 0.5 part of a commercially available dye IR820B (laser light absorption dye manufactured by Nippon Kayaku Co., Ltd.) was added in place of Exemplified Compound 18 in the undercoating liquid of Example 1. A heat-sensitive recording material for infrared laser was obtained.

Comparative Example 2 Red was prepared in the same manner as in Example 1 except that 0.5 part of the heptamethine cyanine dye of Comparative Infrared Absorption Pigment 32 was added instead of Exemplified Compound 18 of the undercoating liquid of Example 1. A heat-sensitive recording material for outer laser was obtained.

[0081]

Embedded image

When a laser beam having a wavelength of 830 nm was imagewise irradiated from the support side of the thermal recording materials obtained in Example 1 and Comparative Example 1, a black image composed of 20 μ dots was obtained in Example 1. Was given. When the recording energy was calculated from the laser energy on the surface of the recording material, the size of the image dot and the irradiation time, the recording energy was 3
It was found to be 00 mJ / cm ² . In Comparative Example 1 and Comparative Example 2, when the irradiation time was increased 3 times and 5 times, respectively, faint dots were observed. Further, in Comparative Examples 1 and 2, the coloring of the dye was strong, and the coloring of the dye was seen through the non-image area. From this, it was confirmed that by using the dye represented by the general formula [1] of the present invention, a heat-sensitive recording material for infrared laser having small coloring in the visible region and high sensitivity can be obtained.

Example 2 The following lower layer coating liquid and upper layer coating liquid were applied with a 0.5 mm wire bar to a transparent polyethylene terephthalate (P) having a thickness of 100 μm.
ET) film was sequentially laminated and a black thermosensitive recording layer was provided to obtain a negative thermosensitive recording material for infrared laser. Lower layer coating liquid 3-dibutylamino-6-methyl-7-anilinofluorane 1.2 parts 5,5'-benzylidene bis- (1,3-diethyl-thiobarbituric acid) 0.8 part Exemplified compoundization 180 4 parts Polyvinyl butyral 5% methyl ethyl ketone solution 25 parts Toluene 5 parts Upper layer coating liquid 1,3-dicyclohexyl-2- (2,5-dimethylphenyl) guanidine 10 parts 5% polyvinyl alcohol aqueous solution 200 parts Dispersed in a ball mill for 2 days.

Then, when a laser beam was irradiated from the side of the support in the same manner as in Example 1, a negative image having a dot-like transparent decoloring and a very high contrast was obtained. At this time, the recording energy was 500 mJ / cm ² .

Example 3 Except for using Exemplified Compound 9 in place of Exemplified Compound 18 in the lower layer coating liquid of Example 2, black-colored heat-sensitive negative type infrared laser was manufactured in exactly the same manner as in Example 2. A recording material was obtained. Next, when a laser beam having a wavelength of 780 nm was used and the laser beam was irradiated from the side of the support in the same manner as in Example 1, a transparent image was erased in a dot shape, and a negative image with extremely high contrast was obtained. At this time, the recording energy was 400 mJ / cm ² .

[0086]

INDUSTRIAL APPLICABILITY The heat-sensitive recording material for infrared laser of the present invention uses the cyanine dye having a spiro ring represented by the general formula [1] as an infrared absorbing dye, so that it absorbs less visible light and has a light color. Regardless, the efficiency of converting the light energy of laser light into heat energy is high, and recording with a small-sized laser with excellent thermal sensitivity and low output is possible.

Claims (1)

[Claims] 1. A heat-sensitive recording material for infrared laser, comprising at least an infrared absorbing dye represented by the general formula [1] on a support. Embedded image (In the general formula [1], R ¹ and R ² may be the same or different from each other and represent an alkyl group, an alkenyl group and an aralkyl group which may have a substituent.
¹ and Y ² may be the same as or different from each other, and at least one of them is a group of non-metal atoms necessary for forming a cyclic hydrocarbon together with the carbon atom at the 3-position of the nitrogen-containing ring. One or more may be substituted with heteroatoms.
Z ¹ and Z ² may be the same or different from each other,
It represents a group of atoms necessary for forming a substituted or unsubstituted benzene ring or naphthalene ring. L ^{1 to} L ³ represent an unsubstituted or substituted methine group, and m is 2 or 3.
X represents an anion, and n represents a number required to adjust the intramolecular charge to zero. )