JPH09111136A - Indolylphthalide compound and recording material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a blue to cyan-colored image having good density and lightfastness by using an indolylphthalide compd. having a specific alkoxylated phenylamino group at the electron-donating colorless dye. SOLUTION: This indolylphthalide compd. is represented by formula I (wherein R<1> is an alkyl or phenyl; R<2> is H or an alkyl; R<3> is an alkoxy, an alkyl, an acylamino, an alkylthio, acetyloxy, phenoxy, or a halogen; R<4> is an alkyl; R<5> is an alkyl or phenyl; R<6> and R<7> are each H, an alkyl, an alkoxy, or a halogen; R<8> is H, an alkyl, an alkoxy, or a halogen; R<9> is H, an alkyl, an alkoxy, or a halogen; and ring A is a group represented by formula II). The amt. of the compd. applied as an electron donating colorless dye is pref. 0.2-1.5g/m<2> , though not specifically limited. The wt. ratio of the dye to an electron-accepting compd. (e.g. a phenol deriv.) in a recording material is pref. (1:5)-(2:3).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel indolylphthalide compound and a recording material using the indolylphthalide compound. The indolyl phthalide compound of the present invention is useful as a recording material using an electron-donating colorless dye and an electron-accepting compound, particularly as an electron-donating colorless dye for recording materials such as pressure-sensitive recording materials and heat-sensitive recording materials. Further, the recording material of the present invention gives a blue-to-cyan image of good density, and has good fastness to light in the image area.

[0002]

2. Description of the Related Art Recording materials using an electron-donating colorless dye and an electron-accepting compound include pressure-sensitive paper, heat-sensitive paper, photosensitive pressure-sensitive paper,
It is already well-known as an energized thermal recording paper, a thermal transfer paper, and the like.

As a recording material, research has recently been earnestly conducted to improve characteristics such as image density, image area fastness and white background fastness.

A triphenylmethanephthalide-based compound as an electron-donating colorless dye that gives a blue to cyan image,
Various compounds such as phenothiazine compounds and indolylphthalide compounds are known.

Among the indolyl phthalide compounds, some examples of so-called indolyl azaphthalide compounds in which the carbon atom of the benzene ring of the phthalide part is replaced with a nitrogen atom are known. Specifically, Japanese Patent Publication No. 61-4856 and Japanese Patent Laid-Open No. 50
-5116, JP-A-60-86166, JP-A-61-1
68664, JP-A-61-291654, Japanese Patent Publication 3-1
6954 and the like. Although some of these give a blue to cyan image of good density, they satisfy all the requirements of color density of the image, good fastness to light in the image area, and little light stain in the white area. The problem is that there is nothing.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides an electron-donating colorless dye which gives a blue to cyan image of good density and has good fastness to light in the image area, and a recording material using the same. That is.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made earnest studies on a compound satisfying the above-mentioned performance with an electron-donating colorless dye which gives a blue to cyan image, and as a result, have a specific alkoxy-substituted phenylamino group. We have found new indolyl phthalide compounds that meet the desired performance.

That is, the above-mentioned problem is solved by the following general formula (I) in a recording material using a novel indolylphthalide compound represented by the following general formula (I) and an electron donating colorless dye and an electron accepting compound. It was achieved by a recording material containing at least one kind of indolyl phthalide compound represented by

[0009]

Embedded image

Where R¹ Is an alkyl group or a phenyl group
Represent. R^Two Represents a hydrogen atom or an alkyl group. R^Three Is
Lucoxy group, alkyl group, acylamino group, alkyl group
O group, acetyloxy group, phenoxy group or halogen
Represents an atom. R^Four Represents an alkyl group. R^Five Is alkyl
Represents a group or a phenyl group. R⁶ , R⁷ Is independently hydrogen
Represents an atom, an alkyl group, an alkoxy group or a halogen atom.
You. Where R¹ And R ⁶And even if they form a ring with each other
Good. R⁸ Is a hydrogen atom, an alkyl group, an alkoxy group or
Represents a halogen atom. R⁹ Represents a hydrogen atom, an alkyl group,
It represents a lucoxy group or a halogen atom. Ring A is below
Represents one of the notations.

[0011]

[Chemical 6]

Further, the recording material of the present invention is a recording material using an electron-donating colorless dye and an electron-accepting compound, and contains at least one or more indolylphthalide compound represented by the above general formula (I). It is characterized by that.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Now, the indolylphthalide compound of the present invention will be described in detail.

The indolylphthalide compound of the present invention is represented by the above general formula (I). In the above general formula (I), R ¹ is preferably an alkyl group having 1 to 16 carbon atoms or a phenyl group, An alkyl group having 1 to 8 carbon atoms is more preferable. These alkyl groups or phenyl groups may be further substituted.

Specific examples of R ¹ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group,
i-butyl group, sec-butyl group, n-pentyl group, i
-Pentyl group, n-hexyl group, n-octyl group, 2-
Ethylhexyl group, n-decyl group, n-dodecyl group, phenyl group, p-tolyl group, p-methoxyphenyl group, p
-Chlorophenyl group and the like are preferable.

R ² is preferably a hydrogen atom or an alkyl group having 1 to 16 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms.

These alkyl groups may be further substituted. Specific examples of R ² include a methyl group, an ethyl group,
n-propyl group, i-propyl group, n-butyl group, i-
A butyl group, sec-butyl group, n-pentyl group, i-pentyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, n-decyl group, n-dodecyl group and the like are preferable.

In the above general formula (I), R ³ is an alkoxy group having 1 to 8 carbon atoms, an alkyl group having 1 to 4 carbon atoms, an acylamino group having 2 to 8 carbon atoms, and 1 to 4 carbon atoms.
Preferred are an alkylthio group having 2 to 8 carbon atoms, an acetyloxy group having 2 to 8 carbon atoms, a phenoxy group, a chlorine atom and a fluorine atom, an alkoxy group having 1 to 4 carbon atoms, an alkyl group having 1 to 3 carbon atoms, and an acylamino having 2 to 5 carbon atoms. A group, an alkylthio group having 1 to 2 carbon atoms, an acetyloxy group having 2 to 5 carbon atoms, a phenoxy group or a chlorine atom is more preferable. Further, among these, the acylamino group may be substituted with a halogen atom, an alkoxy group, an aryloxy group, an N-alkylamino group, an N-arylamino group or the like.

Specific examples of R ³ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group,
i-butyl group, sec-butyl group, methoxy group, ethoxy group, n-butyloxy group, aceryamino group, benzoylamino group, methoxycarbonylamino group, ethoxycarbonylamino group, n-propoxycarbonylamino group, Nn-butyl carbamoyl amino group (n-C ₄ H
_9- NHCONH- group), N-phenylcarbamoylamino group, acyloxy group and the like are preferable.

R ⁴ is preferably an alkyl group having 1 to 4 carbon atoms. Specific examples of R ⁴ include a methyl group, an ethyl group and n-
A propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group and the like are preferable, and a methyl group is more preferable.

In the above general formula (I), R ⁵ is preferably an alkyl group having 1 to 16 carbon atoms or a substitutable phenyl group having 6 to 20 carbon atoms, and the substituent is an alkyl group, an alkoxy group, a halogen atom or the like. In particular, an alkyl group having 1 to 8 carbon atoms or a phenyl group having 6 to 16 carbon atoms which can be substituted is preferable, and the substituent has an alkyl group having 7 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. A group and chlorine atom are preferred.

Specific examples of R ⁵ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group,
i-butyl group, sec-butyl group, n-pentyl group, i
-Pentyl group, n-hexyl group, n-octyl group, 2-
Ethylhexyl group, n-decyl group, n-dodecyl group, cyclopentyl group, cyclohexyl group, benzyl group, 2-
Phenethyl group, 1-phenethyl group, phenyl group, p-tolyl group, formyl group, acetyl group, propionyl group, butyryl group, benzoyl group, chlorine atom and the like are preferable.

R ^{6 to} R ⁹ are each preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a chlorine atom, a fluorine atom or the like, and particularly, an alkyl group having 1 to 4 carbon atoms. A group, an alkoxy group having 1 to 3 carbon atoms, and a chlorine atom are preferable.

Specific examples of R ^{6 to} R ⁹ include hydrogen atom, methyl group, ethyl group, n-propyl group, i-propyl group,
n-butyl group, i-butyl group, sec-butyl group, n-
Pentyl group, i-pentyl group, n-hexyl group, methoxy group, ethoxy group, chlorine atom and the like are preferable.

R ¹ and R ⁶ may form a ring with each other. In the above general formula (I), as the ring A, those represented by the following formulas (A-1), (A-2) and (A-3) are preferable, and particularly, the following formula (A-1) Or what is represented by (A-2) is preferable.

[0026]

Embedded image

Specific examples of the indolylphthalide compound according to the present invention will be shown below, but the present invention is not limited thereto.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

Embedded image

The indolyl phthalide compound of the present invention may be a mixture of isomers produced as a by-product during production. For example, in addition to the phthalide body, a mixture of a 4-azaphthalide body and a 7-azaphthalide body, or a mixture of a 5-azaphthalide body and a 6-azaphthalide body may be used.

The indolyl phthalide compound according to the present invention may be used alone or in combination of two or more kinds. For example, two or more 4-azaphthalide compounds may be used in combination, one phthalide compound and a 4-azaphthalide compound, or 4
-One kind of azaphthalide body and one kind of 6-azaphthalide body may be used in combination.

When the indolylphthalide compound of the present invention is used as an electron-donating colorless dye for a heat-sensitive recording material, conventionally known triphenylmethanephthalide compounds, fluorane compounds, phenothiazine compounds, indolylphthalide compounds. Compounds, leuco auramine compounds, rhodamine lactam compounds, triphenylmethane compounds,
It can be used in combination with various compounds such as triazene compounds, spiropyran compounds and fluorene compounds.
Specific examples of the phthalides include US Reissue Patent Specification No. 23,0.
No. 24, US Pat. Nos. 3,491,111, 3,491,112, 3,491,116 and 3,509,174, and specific examples of fluoranes are US patents. Description No. 3,624,107, No. 3,62
7,787, 3,641,011, and 3,4
No. 62,828, No. 3,681,390, No. 3,
920,510, 3,959,571, and specific examples of spirodipyrans are described in US Pat. No. 3,971,8.
No. 08, pyridine compounds and pyrazine compounds are described in US Pat. Nos. 3,775,424 and 3,853,8.
No. 69, No. 4,246,318 and specific examples of fluorene compounds are described in JP-A-63-94878 and the like.

The coating amount of the electron-donating colorless dye according to the present invention is not particularly limited, but is preferably 0.1 to 2.0 g / m ² , particularly 0.2 to 1.5 g / m ² .

Examples of the electron-accepting compound used in the recording material of the present invention include phenol derivatives, salicylic acid derivatives, metal salts of aromatic carboxylic acids, acid clay, bentonite, novolac resins, metal-treated novolac resins and metal complexes. To be

Examples of these are JP-B-40-9309, JP-B-45-14039, and JP-A-52-140483.
JP-A-48-51510, JP-A-57-2108
86, JP-A-58-87089, and JP-A-59-11.
286, JP-A-60-176795, JP-A-61-176
No. 95988, etc.

The ratio of the electron-donating colorless dye to the electron-accepting compound used is preferably 1:10 to 1: 1 by weight, more preferably 1: 5 to 2: 3.

The indolyl phthalide compound according to the present invention may be used in combination with conventionally known ultraviolet absorbers, fluorescent whitening agents and antioxidants.

Preferred UV absorbers that can be used in combination are benzophenone UV absorbers, benzotriazole UV absorbers, salicylic acid UV absorbers, cyanoacrylate UV absorbers, oxalic acid anilide UV absorbers and the like. Can be mentioned. Examples of these are JP-A-47-10537 and JP-A-58-111942.
No. 58, No. 58-212844, No. 59-19925,
59-46646, 59-109055, 6
3-53544, Japanese Patent Publication No. 36-10466, 42
No. 26187, No. 48-30492, No. 48-31
No. 255, No. 48-41572, No. 48-54965.
No. 50-10726, US Pat. No. 2,719,08
No. 6, No. 3,707,375, No. 3,754,919
No. 4,220,711 and the like.

Preferred examples of the fluorescent whitening agent that can be used in combination include coumarin-based fluorescent whitening agents. Examples of these are described in JP-B-45-4699 and JP-A-54-5324.

Preferred antioxidants that can be used in combination include hindered amine antioxidants, hindered phenol antioxidants, aniline antioxidants, quinoline antioxidants and the like. Examples of these are JP-A-59
-155090, 60-107383, 60-
107384, 61-1377770, 61-13.
No. 9481, 61-160287 and the like.

The amount of the ultraviolet absorber, fluorescent brightening agent, and antioxidant that can be used in combination is 0.05 to 1.0 g / m ² ,
Particularly, 0.1 to 0.4 g / m ² is preferable.

When the recording material of the present invention is used for pressure-sensitive paper, US Pat. Nos. 2,505,470 and 2,505,505.
No. 471, No. 2,505,489, No. 2,548,3
No. 66, No. 2,712,507, No. 2,730,45
No. 6, No. 2,730,457, No. 3,103,404
Various forms can be adopted as described in the prior patents such as No. 3,418,250, and No. 4,010,038. Most commonly it consists of at least one pair of sheets separately containing an electron donating colorless dye and an electron accepting compound.

Regarding the method for producing capsules, a method utilizing coacervation of a hydrophilic colloid sol described in US Pat. Nos. 2,800,457 and 2,800,458, and US Pat. No. 3,287,154. British patent 8
67,797, 950,443, 989,26
No. 4, No. 990,443, No. 1,091,076,
Japanese Examined Patent Publication No. 38-19574, No. 42-446, No. 42
Interfacial polymerization method described in US Pat.
Methods by precipitation of polymers described in U.S. Pat. No. 4,418,250 and U.S. Pat. No. 3,418,2.
A method using the isocyanate polyol wall material described in US Pat. No. 50, a method using the isocyanate wall material described in US Pat. No. 3,914,511, US Pat.
01,140, 4,087,376, 4,08
Urea-formaldehyde system described in No. 9,802,
Method using wall forming material such as melamine-formaldehyde resin and hydroxypropyl cellulose using urea formaldehyde-resorcinol type wall material, JP-B-36
-9168, in-situ method by polymerization of monomers described in JP-A-51-9079, British Patent 95
2,807, 965,074, electrolytic dispersion cooling method, US Pat. No. 3,111,407, British patent 9
There is a spray drying method described in No. 30,422. Although not limited thereto, it is preferable to form a polymer film as a microcapsule wall after emulsifying the core substance.

Generally, an electron-donating colorless dye is mixed with a solvent (alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, alkylated terphenyl, chlorinated paraffin and the like synthetic oil: vegetable oil such as cotton oil and castor oil). : Animal oil: Mineral oil or mixtures thereof)
Dissolve in the microcapsules contained in paper,
A color former sheet is obtained by applying it to high-quality paper, plastic sheet, resin-coated paper, or the like.

Further, the electron-accepting compound and, if necessary, the additives are dispersed alone or in a mixture in a binder such as styrene-butadiene latex or polyvinyl alcohol, and together with the pigment, paper, plastic sheet, resin coated paper, etc. A color developer sheet is obtained by applying it to a support.

As the binder, it is preferable to use a carboxy-modified styrene-butadiene latex in combination with a water-soluble polymer from the viewpoint of light resistance and water resistance. As the pigment, it is preferable to use calcium carbonate having an average particle size of 5.0 μm or less in terms of color developing ability in an amount of 60% by weight or more of the total pigment.

The amount of the electron-donating colorless dye and the electron-accepting compound used depends on the desired coating thickness, the form of the pressure-sensitive recording paper, the capsule manufacturing method, and other conditions, and may be appropriately selected according to the conditions. It is easy for those skilled in the art to determine this amount.

When it is used for thermal paper, it is disclosed in JP-A-62-1.
44,989, JP-A-1-87291, and the like. Specifically, the electron-donating colorless dye and the electron-accepting compound are 10 μm in the dispersion medium.
Hereinafter, it is preferably used by pulverizing and dispersing to a particle size of 3 μm or less. As the dispersion medium, a water-soluble polymer aqueous solution having a concentration of about 0.5 to 10% is generally used, and dispersion is performed by a ball mill,
It is carried out by using a sand mill, a horizontal sand mill, an attritor, a colloidal mill or the like.

At that time, a thermofusible substance may be contained in the thermosensitive coloring layer in order to improve the thermal response. Representative examples of the heat-fusible material include aromatic ethers, thioethers, esters, and / or aliphatic amides or ureides.

Examples of these are disclosed in JP-A-58-57989,
No. 58-87094, No. 61-58789, No. 62
No. -109681, No. 62-132677, No. 63-
151478, 63-235961, JP-A-2-
No. 184489 and No. 2-215585.

These are used at the same time as the electron-donating colorless dye or at the same time as being finely dispersed at the same time as the electron-accepting compound. 20% or more and 30% of the amount of these used and the electron-accepting compound
0% or less by weight, especially 40% or more and 150%
The following is preferred.

Additives are added to the coating solution thus obtained, if necessary, in order to meet various requirements. As an example of the additive, in order to prevent contamination of the recording head at the time of recording, an inorganic pigment, an oil absorbing substance such as polyurea filler is dispersed in a binder,
Furthermore, fatty acids, metal soaps, etc. are added to enhance the releasability of the head. Therefore, in general, in addition to electron-donating colorless dyes and electron-accepting compounds that directly contribute to color development, heat-fusible substances, pigments, waxes, antistatic agents, ultraviolet absorbers, defoamers, conductive agents, fluorescent dyes Then, an additive such as a surfactant is applied on the support to form a recording material. Further, if necessary, a protective layer may be provided on the surface of the heat-sensitive recording layer.

Usually, the electron-donating colorless dye and the electron-accepting compound are dispersed and applied in a binder. Water-soluble binders are generally used, and polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, epichlorohydrin-modified polyamide, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-anhydrous. Examples thereof include maleic salicylic acid copolymer, polyacrylic acid, polyacrylic acid amide, methylol-modified polyacrylamide, starch derivative, casein, gelatin and the like. Further, a water-proofing agent may be added to these binders for the purpose of imparting water resistance, or an emulsion of a hydrophobic polymer, specifically, a styrene-butadiene rubber latex, an acrylic resin emulsion or the like may be added. The amount of these used is preferably 0.4 to 5 g / m ² , more preferably 0.8
˜1.6 g / m ² is preferred.

The obtained heat-sensitive coating liquid is applied to high-quality paper, high-quality paper having an undercoat layer, synthetic paper, plastic film and the like. At this time, it is particularly preferable from the standpoint of dot reproducibility to use a support having a smoothness of 500 seconds or more, particularly 800 seconds or more defined by JIS-P8119.

In the recording material of the present invention, known wax, antistatic agent, defoaming agent, conductive agent,
Various additives such as fluorescent dyes, surfactants, and ultraviolet absorber precursors can be used.

In the recording material of the present invention, a protective layer may be provided on the surface of the recording layer, if necessary. Two or more protective layers may be laminated if necessary. Materials used for the protective layer include polyvinyl alcohol, carboxy-modified polyvinyl alcohol, vinyl acetate-acrylamide copolymer, silicon-modified polyvinyl alcohol, starch, modified starch, methyl cellulose, carboxymethyl cellulose, hydroxymethyl cellulose, gelatins, gum arabic, casein, Styrene-maleic acid copolymer hydrolyzate, styrene-maleic acid copolymer half ester hydrolyzate, isobutylene-maleic anhydride copolymer hydrolyzate, polyacrylamide derivative, polyvinylpyrrolidone, sodium polystyrene sulfonate, sodium alginate Water-soluble polymer compounds such as styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex,
Latexes such as methyl acrylate-butadiene rubber latex and vinyl acetate emulsion are used. The water-soluble polymer compound in the protective layer can be crosslinked to further improve the storage stability, and a known crosslinking agent can be used as the crosslinking agent. Specifically, water-soluble initial condensates such as N-methylol urea, N-methylol melamine, and urea-formalin, dialdehyde compounds such as glyoxal and glutaraldehyde, inorganic cross-linking agents such as boric acid and borax, polyamide epichlorohydrin, etc. Can be mentioned. For the protective layer, known pigments, metal soaps, waxes, surfactants and the like can be further used. The coating amount of the protective layer is preferably 0.2 to 5 g / m ² , more preferably 0.
5 to ² g / m ² is preferable. The film thickness is 0.2 to 5
μm is preferable, and 0.5 to 2 μm is particularly preferable.

When a protective layer is used in the recording material of the present invention, a known UV absorber or its precursor may be contained in the protective layer.

As the support that can be used in the recording material of the present invention, acid paper, neutral paper, coated paper, plastic film laminated paper, synthetic paper, plastic film and the like can be used. Further, these supports may be provided with a known undercoat layer. This undercoat layer can be provided in the same manner as the protective layer.

In order to correct the curl balance of the support or to improve the chemical resistance from the back side, a back coat layer may be provided, and the back side may be combined with a release paper via an adhesive layer to label the label. You may take the form of. This back coat layer can be provided in the same manner as the above protective layer.

The indolyl phthalide compound of the present invention was prepared according to US Pat. Nos. 4,399,209 and 4,551,407.
Issue 4,440,846, Issue 4,536,463
JP-A-63-184738, JP-A-58-88739.
No. 62-143044, JP-A-2-188293.
No. 2, No. 2-188294, No. 3-72358, No. 3-
No. 87827, No. 4-226455, No. 4-2479.
It can be applied to various recording materials described in No. 85, No. 5-124360, No. 5-294063 and the like.

The indolylphthalide compound of the present invention can be used in a heat-sensitive recording material, particularly a multicolor heat-sensitive recording material. Regarding this multicolor heat-sensitive recording material (photosensitive heat-sensitive recording material), JP-A-4-135787 and JP-A-4-1447.
No. 84, No. 4-144785, No. 4-194.
No. 842, No. 4-247447, and No. 4-24.
No. 7448, No. 4-340540, and No. 4-3.
No. 40541 and No. 5-34860. Specifically, it can be obtained by laminating thermosensitive recording layers that develop colors of different colors. The layer structure is not particularly limited, but in particular, a thermosensitive recording layer 2 in which two types of diazonium salt compounds having different photosensitizing wavelengths are combined with respective diazonium salt compounds to combine with a coupler capable of developing a different hue A multicolor heat-sensitive recording material in which a layer and a heat-sensitive recording layer in which an electron-donating colorless dye and an electron-accepting compound are combined are laminated is preferable.

That is, a first heat-sensitive recording layer containing an electron-donating colorless dye and an electron-accepting compound on a support, a diazonium salt compound having a maximum absorption wavelength of 360 nm ± 20 nm, and a reaction with the diazonium salt compound during heat treatment. Second heat-sensitive recording layer containing color coupler, maximum absorption wavelength 400
The third heat-sensitive recording layer contains a diazonium salt compound having a wavelength of ± 20 nm and a coupler that reacts with the diazonium salt compound to produce a color when heated. In this example,
If the coloring hue of each heat-sensitive recording layer is selected to be the three primary colors in subtractive color mixing, yellow, magenta, and cyan,
Full-color image recording is possible.

In the recording method of this multicolor heat-sensitive recording material, first, the third heat-sensitive recording layer is heated to cause the diazonium salt and the coupler contained in the layer to develop color. Next 400 ± 20 nm
Is irradiated to decompose the unreacted diazonium salt compound contained in the third thermosensitive recording layer, and then the second thermosensitive recording layer is provided with sufficient heat to develop a color. The colored diazonium salt compound and the coupler are colored.
At this time, the third thermosensitive recording layer is also heated strongly at the same time,
Since the diazonium salt compound has already been decomposed and the coloring ability has been lost, it does not develop color. Further 360 ± 20 nm
Is irradiated to decompose the diazonium salt compound contained in the second thermosensitive recording layer, and finally, sufficient heat for coloring the first thermosensitive recording layer is applied to cause color development. At this time, the third,
The second thermosensitive recording layer is also heated strongly at the same time, but the diazonium salt compound is already decomposed and the coloring ability is lost, so that no coloring occurs.

When the recording material of the present invention is a multicolor thermosensitive recording material, an intermediate layer may be provided in order to prevent color mixing between the thermosensitive recording layers. This intermediate layer is made of a water-soluble polymer compound such as gelatin, phthalated gelatin, polyvinyl alcohol, and polyvinylpyrrolidone, and may appropriately contain various additives. The coating amount is preferably from 2 to 10 g / m ^2, more preferably 4-5 g / m ^2. The film thickness is preferably 0.5 to 10 μm.

[0067]

[Example 1]

Synthesis of compound 8 of the present invention N-ethyl-4,3'-dimethoxydiphenylamine 2
5.7 g and 2- (1-ethyl-2-methylindole-
3-yl) 3-carboxypyridine (30.8 g) was reacted in a solution of acetic anhydride (30 ml) and acetic acid (30 ml) at 65 ° C for 3 hours. The reaction mixture was poured into ice water, cooled, neutralized with aqueous ammonia, and the precipitated crystals were filtered. The obtained crude crystals were recrystallized from ethyl acetate-ethanol,
34.1 g of the present compound 8 was obtained.

For this compound, ¹ H-NMR is shown below.
The peak data obtained by are shown. The chemical shift data values of the following peaks show the δ value from TMS which is the reference substance, and the number of protons in that peak and the peak shape such as singlet and doublet are shown in parentheses. below
The structure of Compound 8 of the present invention was confirmed by ¹ H-NMR analysis.

¹ H-NMR (CDCl ₃ ) δ (TM
S, ppm) 1.16 (3H, t), 1.30 (3H, t), 2.4
9 (3H, s), 3.19 (3H, s), 3.65 (2
H, qr), 3.79 (3H, s), 4.14 (2H,
qr), 6.05 (1H, d), 6.14 (1H, d
d), 6.88 (2H, d), 6.96-70.3 (2
H, m), 7.05-7.13 (3H, m), 7.23.
(1H, d), 7.31 (1H, dd), 7.88 (1
H, d), 8.14 (1H, dd), 8.73 (1H,
dd) [Example 2] N-ethyl-4,3'-dimethoxydiphenylamine and 2- (1-ethyl-2-methylindol-3-yl) 3-carboxypyridine of Example 1 were mixed with N
-Ethyl-4,3'-dimethoxydiphenylamine and 2
The present compound 9 (Example 2) was synthesized by reacting in the same manner as in Example 1 except that-(1-n-hexyl-2-methylindol-3-yl) 3-carboxypyridine was used. The results of ¹ H-NMR analysis of this compound are shown. From this result, the structure of the compound was confirmed.

Example 2 Compound of the present invention 9 ¹ H-NMR (CDCl ₃ ) δ (TMS, ppm) 0.87 (3H, t), 1.24-1.38 (6H,
m), 1.69 (2H, m), 2.47 (3H, s),
3.21 (6H, s), 3.79 (3H, s), 4.0
6 (2H, t), 6.12 (1H, dd), 6.18
(1H, dd), 6.88 (2H, d), 6.98 (1
H, t), 7.03-7.12 (4H, m), 7.22.
(1H, d), 7.31 (1H, dd), 7.84 (1
H, d), 8.14 (1H, dd), 8.73 (1H,
dd) [Example 3] N-ethyl-4,3'-dimethoxydiphenylamine and 2- (1-ethyl-2-methylindol-3-yl) 3-carboxypyridine of Example 1 were mixed with N
-Ethyl-2,4,3'-trimethoxydiphenylamine and 2- (1-n-pentyl-2-methylindole-
The compound of the present invention 19 (Example 3) was synthesized by reacting in the same manner as in Example 1 except that 3-yl) -3-carboxypyridine was used instead. The results of ¹ H-NMR analysis of this compound are shown. From this result, the structure of the compound was confirmed.

Example 3 Compound of the present invention 19 ¹ H-NMR (CDCl ₃ ) δ (TMS, ppm) 0.98 (3H, t), 1.28-1.37 (4H,
m), 1.70 (2H, m), 2.46 (2H, s),
3.13 (3H, s), 3.20 (3H, s), 3.7
2 (3H, s), 3.79 (3H, s), 4.04 (2
H, t), 5.99 (1H, dd), 6.04 (1H,
dd), 6.43 (1H, dd), 6.51 (1H,
d), 6.96-70.2 (2H, m), 7.04-
7.11 (2H, m), 8.21 (1H, d), 7.2
9 (1H, dd), 7.86 (1H, d), 8.12
(1H, dd), 8.71 (1H, dd) [Example 4] N-ethyl-4,3'-dimethoxydiphenylamine of Example 1 and 2- (1-ethyl-2-methylindol-3-yl) ) 3-carboxypyridine, N
-Ethyl-3,4,5,3'-tetramethoxydiphenylamine and 2- (1-n-pentyl-2-methylindol-3-yl) 3-carboxypyridine were replaced by the same reaction as in Example 1. Then, the compound 22 of the present invention (Example 4) was synthesized. The results of ¹ H-NMR analysis of this compound are shown. From this result, the structure of the compound was confirmed.

Example 4 Compound of the present invention 22 ¹ H-NMR (CDCl ₃ ) δ (TMS, ppm) 0.91 (3H, t), 1.31-1.37 (5H,
m), 1.61 (2H, m), 2.42 (3H, s),
3.24 (6H, s), 3.78 (6H, s), 3.8
3 (3H, s), 4.06 (2H, t), 6.26-
6.31 (2H, m), 6.38 (2H, s), 6.9
8 (1H, t), 7.06-7.13 (sH, m),
7.23 (1H, d), 7.33 (1H, dd), 7.
85 (1H, d), 8.15 (1H, dd), 8.73
(1H, dd) [Example 5] 1) Preparation of an electron-donating colorless dye-containing capsule sheet 5 parts of a partial sodium salt of polyvinylbenzenesulfonic acid (VERSA, TL500 manufactured by National Starch Co., Ltd.) was dissolved in 95 parts of water. To do. An aqueous solution of sodium hydroxide was added thereto to adjust the pH to 4.0. On the other hand, 100 parts of diisopropylnaphthalene in which 6.8 g of the compound 8 of the present invention, which is an electron-donating colorless dye, is emulsified and dispersed in 100 parts of a 5% aqueous solution of a partial sodium salt of polyvinylbenzenesulfonic acid to obtain a diameter of 4. An emulsion with a particle size of 0μ was obtained.

Separately, 6 parts of melamine, 11 parts of 37% by weight formaldehyde aqueous solution and 30 parts of water were heated and stirred at 60 ° C. to obtain a transparent aqueous solution of melamine formaldehyde prepolymer. This aqueous solution was mixed with the above emulsion. While stirring, adjust the pH to 6.0 with phosphoric acid aqueous solution and adjust the liquid temperature to 65
The temperature was raised to ° C and stirring was continued for 6 hours. The capsule solution was cooled to room temperature and adjusted to pH 9.0 with an aqueous sodium hydroxide solution.

To this dispersion, 200 parts of a 10% by weight aqueous polyvinyl alcohol solution and 50 parts of starch particles were added and water was added to prepare a 20% solids concentration solution of the microcapsule dispersion.

This coating solution was applied to a base paper of 50 g / m ² at 5 g / m
The solid content of ² was applied by an air knife coater so as to be dried, and an electron-donating colorless dye-containing capsule sheet was obtained. 2) Preparation of electron-accepting compound sheet 3,5-bis (α-methylbenzyl) salicylate zinc 1
A dispersion liquid consisting of 4 parts, 80 parts of calcium carbonate, 20 parts of zinc oxide, 1 part of sodium hexametaphosphate and 200 parts of water was dispersed by a sand glider so that the average particle diameter was 3 μm. To this dispersion, 100 parts of a 10% PVA aqueous solution and 10 parts of carboxy-modified SBR latex (as solid content) were added, and water was added so that the solid content concentration became 20% to obtain a coating liquid. This coating solution was applied to 50 g / m ² base paper.
An electron-accepting compound sheet was obtained by coating with an air knife coater so that a solid content of 0 g / m ² was coated and drying. 3) Image recording On the surface of the microcapsule sheet containing the electron-donating colorless dye,
It was superposed on the electron-accepting compound sheet and a load of 300 kg / cm ² was applied to develop the color, whereby a blue color image was obtained. 4) Performance evaluation of recording paper (light resistance test of image part) For the obtained image (color image),
Xenon Fade Meter (FAL-25AX-HC
Type, manufactured by Suga Test Instruments) for 4 hours. The image density D after light irradiation and the image density D ₀ before light irradiation were measured with a Macbeth reflection densitometer. The light fastness is shown as a standard with the residual rate of the image after light irradiation = (D / D ₀ ) × 100%. The higher the residual rate, the better the light fastness. [Examples 6 to 8] The electron-donating colorless dye of Example 5 (the present compound 8) was used as the present compound 9 (Example 6), the present compound 19 (Example 7), and the present compound 22 (Example). 8)
A microcapsule sheet was obtained in the same manner as in Example 5, except for changing the above. Image recording and recording paper performance evaluation were performed in the same manner as in Example 5. [Comparative Examples 1 and 2] Except that the electron donating colorless dye of Example 5 (Compound 8 of the invention) was replaced with Comparative Compound B-1 (Comparative Example 1) and Comparative Compound B-2 (Comparative Example 2) below. Example 5
A microcapsule sheet was obtained in the same manner as. Example 5
Image recording and performance evaluation of recording paper were performed in the same manner as in.

[0076]

Embedded image

The results of Examples 5-8 and Comparative Examples 1-2 are shown in Table 4.

[0078]

[Table 4]

As is apparent from Table 4, all the heat-sensitive recording materials using the compound of the present invention had high image light fastness. On the other hand, it was found that the comparative examples using the indolylphthalide compound outside the scope of the present invention had insufficient image light fastness. [Example 9] 1) Preparation of a heat-sensitive recording material in which an electron-donating colorless dye or the like is solid-dispersed A compound of the present invention 8 which is an electron-donating colorless dye, bisphenol A which is an electron-accepting compound, and a heat-fusible compound. 4,4 ', 4 "-trimethoxytriphenylamine, 20 g each, 100 g polyvinyl alcohol (PVA
105, manufactured by Kuraray Co., Ltd.) and dispersed with a 5% aqueous solution in a ball mill overnight to prepare a dispersion liquid. The volume average particle diameter of each compound in the obtained dispersion was 3 μm. On the other hand, 80 g of calcined kaolin (Anisilex-93: manufactured by Engelhardt Co., Ltd.) was mixed with 0.
The mixture was dispersed with 160 g of a 5% solution using a homogenizer.

5 g of the electron-donating colorless dye dispersion liquid and 5 g of the electron-accepting compound dispersion liquid 5 were obtained from the dispersion liquids obtained as described above.
g, 10 g of the heat-fusible compound dispersion and 22 g of the calcined kaolin dispersion, and 4 g of zinc stearate emulsion and 5 g of a 2% aqueous solution of sodium di (2-ethylhexyl) sulfosuccinate were added. A coating liquid was obtained.

This coating solution was applied on a high-quality paper having a basis weight of 50 g / m ^{2 with} a wire bar so that the dry coating amount was 6 g / m ² , and then calendered to obtain a coated paper.

The coated paper obtained as described above was printed using a thermal head KLT-216-8MPD1 (manufactured by Kyocera Corporation), and a blue image was obtained.

With respect to the thermosensitive recording material on which this image was recorded, the performance of the image portion of the recording paper was evaluated in the same manner as in Example 5 except that the light irradiation time was 24 hours. [Examples 10 to 12] The present invention compound example 8 in Example 9 was replaced with the present invention compound 9 (Example 10), the present invention compound 1
9 (Example 11), a thermosensitive recording paper was obtained in the same manner as in Example 5 except that the compound 22 of the present invention (Example 12) was used.
Image recording was performed. The performance of the image portion of the recording paper was evaluated in the same manner as in Example 9 for the thermosensitive recording material on which the obtained image was recorded. [Comparative Examples 3 to 4] The electron-donating colorless dye of Example 9 (inventive compound 8) was changed to Comparative Compound B-1 (Comparative Example 3) and Comparative Compound B-2 (Comparative Example 4). Example 9
In the same manner as above, a thermosensitive recording paper was obtained and an image was recorded. The performance of the image portion of the recording paper was evaluated in the same manner as in Example 9 for the thermosensitive recording material on which the obtained image was recorded.

Table 5 shows the results of Examples 9 to 12 and Comparative Examples 3 to 4.

[0085]

[Table 5]

As is clear from Table 5, the heat-sensitive recording material using the compound of the present invention, even when prepared in a solid dispersion system,
As in the case of encapsulation in a capsule, all had high image light resistance. On the other hand, it was found that the comparative examples using the indolylphthalide compound outside the scope of the present invention had insufficient image light fastness. [Embodiment 13] An example of producing a multi-layered multicolor heat-sensitive recording material according to the present invention capable of independently recording three colors of yellow, magenta and cyan to reproduce a full-color image will be described below. (1) Preparation of Coating Solution for Cyan Thermosensitive Coloring Layer (A Layer) (Preparation of Capsule Solution Containing Electron-donating Colorless Dye) Layer A-1 After dissolving 3 parts of the indolylphthalide compound of Example 1 (invention compound example 8) in 20 parts of ethyl acetate, alkylnaphthalene (20 parts of high boiling point solvent was added and heated) Mix evenly.

To the obtained solution, 20 parts of xylylene diisocyanate / trimethylol propane 1 to 3 adduct (Takenate D-110N: trade name, manufactured by Takeda Pharmaceutical Co., Ltd.) was added and stirred uniformly to obtain an electron. A solution of a donative colorless dye was prepared. 2. A layer-2 A solution prepared by adding 2 parts of an aqueous solution of 2% by weight of sodium dotesylsulfonate to 54 parts of an aqueous solution of 6% of phthalated gelatin was added with the above solution of the electron-donating colorless dye,
The mixture was emulsified and dispersed using a homogenizer to obtain an emulsified dispersion. 68 parts of water was added to the obtained emulsified dispersion, mixed and homogenized, and then heated to 50 ° C. while stirring the mixture,
The encapsulation reaction was performed for 3 hours so that the average particle size of the microcapsules became 1.6 μm, to obtain a capsule liquid. (Preparation of Emulsion Dispersion of Electron-Accepting Compound) Bisphenol P, which is the electron-accepting compound used in Example 1, was added to 150 parts of a 4% aqueous solution of polyvinyl alcohol, and then dispersed by a ball mill for 24 hours to obtain a dispersion. The mixture was added to a solution prepared by mixing 45 parts of an aqueous solution of 15% phthalated gelatin and 5 parts of an aqueous solution of 10% sodium dodecylsulfonate, and the mixture was emulsified for 10 minutes using a homogenizer to obtain an emulsion dispersion. (Preparation of Coating Solution) A coating solution was obtained by mixing a capsule solution containing an electron-donating colorless dye and an emulsified dispersion of an electron-accepting compound in a weight ratio of 1: 4.

(2) Coating for magenta thermosensitive coloring layer (layer B)
Preparation of liquid ( preparation of capsule liquid containing diazo compound) 4-N-
2.0 parts of (2- (2,4-di-tert-amylphenoxy) butyryl) piperazinobenzenediazonium hexafluorophosphate (diazo compound: decomposed with light having a wavelength of 365 nm) was dissolved in 20 parts of ethyl acetate. rear,
Further, 20 parts of alkylnaphthalene was added and heated to uniformly mix. Takenate D-110N was added to the resulting solution.
15 parts of (capsule wall agent) was added and uniformly mixed to obtain a solution of diazo compound. The obtained solution of the diazo compound is added to a solution obtained by mixing 54 parts of a 6% aqueous solution of polyvinyl alcohol (having a degree of polymerization of 1700 and a saponification degree of 88%) with 2 parts of an aqueous solution of 2% sodium dodecylsulfonate, The mixture was emulsified and dispersed using a homogenizer.

68 parts of water was added to the obtained emulsified dispersion liquid and mixed uniformly, and the mixture was heated to 40 ° C. with stirring to carry out an encapsulation reaction for 3 hours so that the average particle size of the capsules would be 1.1 μm. Then, a capsule liquid was obtained. (Preparation of coupler emulsion dispersion) 1-phenyl-3-
(2,5-di-n-octyloxyphenyl) barbituric acid 2 parts, 1,2,3-triphenylguanidine 2
Parts, tricresyl phosphate 0.3 parts and diethyl maleate 0.1 parts were dissolved in ethyl acetate 10 parts.
The obtained solution was put into an aqueous solution obtained by mixing 50 g of an aqueous solution of 6% by weight of gelatin and 2 g of an aqueous solution of 2% of sodium dodecylsulfonate, and then using a homogenizer, 10
It was emulsified for minutes to obtain an emulsified dispersion. (Preparation of coating solution) A capsule solution containing a diazo compound and a coupler emulsified dispersion were mixed at a weight ratio of 2 to 3 to obtain a coating solution.

(3) Coating for yellow thermosensitive coloring layer (C layer)
Preparation of liquid ( preparation of capsule liquid containing diazo compound) 2,5-
After dissolving 3.0 parts of dibutoxy-4-tolylthiobenzenediazonium hexafluorophosphate (diazo compound: decomposed by light having a wavelength of 420 nm) in 20 parts of ethyl acetate, alkylnaphthalene 20 as a high-boiling solvent was added thereto.
Parts were added and heated to mix uniformly. Takenate D-110N as a capsule wall material was added to the obtained solution for 15 minutes.
Were added and mixed uniformly to obtain a solution of a diazo compound.
The obtained solution of the diazo compound was diluted with 6% of phthalated gelatin.
Was added to a mixed solution of 54 parts of an aqueous solution of the above and 2 parts of an aqueous solution of sodium dodecylsulfonate, and emulsified and dispersed using a homogenizer. A solution obtained by adding 68 parts of water to the obtained emulsified dispersion and uniformly mixing the mixture was heated to 40 ° C. with further stirring, and the mixture was adjusted to a particle size of 1.3 μm with an average particle size of 1.3 μm.
The encapsulation reaction was performed for a time to obtain a capsule liquid. (Preparation of coupler emulsified dispersion) 2-chloro-5- (3-
(2,4-Di-tert-pentyl) phenoxypropylamino) acetoacetanilide 2 parts, 1,2,3-triphenylguanidine 1 part, tricresyl phosphate 0.3 part and diethyl maleate 0.1 part are acetic acid. The mixture was dissolved in 10 parts of ethyl, and was added to an aqueous solution in which 50 g of a 6% aqueous solution of gelatin and 2 g of a 2% aqueous solution of sodium dodecylsulfonate were mixed and then emulsified for 10 minutes using a homogenizer to obtain an emulsion dispersion. . (Preparation of Coating Liquid) A capsule liquid containing a diazo compound and a coupler emulsified dispersion were mixed at a weight ratio of 2: 3 to obtain a coating liquid. (4) Preparation of coating solution for intermediate layer In 10 g of 24% aqueous solution of gelatin (# 750: trade name, manufactured by Nitta Gelatin Co., Ltd.), hollow capsules made of acrylic-styrene resin (ROPEK OP-62: trade name, ROHM) 2.4 g (manufactured by And Haas Co.) was added and mixed uniformly to obtain an intermediate layer liquid.

(5) Preparation of coating liquid for protective layer Itaconic acid-modified polyvinyl alcohol (KL-318:
(Trade name, manufactured by Kuraray Co., Ltd.)
To a liquid obtained by mixing 10 g of a 30% dispersion of an epoxy-modified polyamide (FL-71: trade name, manufactured by Toho Chemical Co., Ltd.), a dispersion of 40% zinc stearate (Hydrin Z:
15 g of trade name (manufactured by Chukyo Yushi Co., Ltd.) was added to obtain a protective layer liquid. Coating solution for back layer 1,200 g of a 4% aqueous solution of gelatin was used as a coating solution for the back layer. Preparation of a support provided with an undercoat layer After applying SBR latex to both sides of polyethylene terephthalate having a thickness of 175 μm so as to have a solid content of 0.3 g / m ² , the following coating solution for undercoat layer was applied on one side. A support having an undercoat layer was obtained by applying the composition on both sides such that the weight of the solid content per unit area was 0.1 g / m ² . Preparation of Coating Solution for Undercoat Layer 200 g of a 5% aqueous solution of gelatin (# 810: manufactured by Nitta Gelatin Co., Ltd.), 0.5 g of a gelatin dispersion in which 5% of polymethyl methacrylate resin particles having a particle size of 2 μm are dispersed,
1,3-benzothiazolin-3-one 3% aqueous solution 1.0
g, di (2-ethyl) hexyl sulfonate 2% aqueous solution 1
0 g was mixed to obtain an undercoat layer coating solution. (6) Preparation of multicolor thermosensitive recording material 1.8 g / m ² in solid content on one side of the transparent support provided with an undercoat layer, which has been already prepared (as a thickness after drying, 1
(0 μm) was applied and dried.

Then, on the other surface, using a slide type hopper type bead coating device, a cyan thermosensitive color developing layer solution, an intermediate layer solution, a magenta thermosensitive color developing layer solution, an intermediate layer solution, and a yellow color were sequentially applied on the slide from the support side. A multi-layered multi-layer coating was applied so as to be a thermosensitive color developing layer solution and a protective layer solution, and dried to obtain a multicolor thermosensitive recording material.

[0093] The coating amount in terms of solid content after drying, cyan thermosensitive recording layer is 6.1 g / m ^2, the magenta heat-sensitive recording layer is 7.8 g / m ^2, an intermediate layer (gelatin 1.2 g / m ² ,
Hollow capsules 1.2 g / m ² ) 2.4 g / m ² , yellow thermosensitive recording layer 7.2 g / m ² , and protective layer 2.0 g.
Each coating solution was applied so as to be / m ² . (7) Thermal recording Using the obtained recording material, recording was performed as follows.

An image of the recording heat energy per unit area measured by a Macbeth densitometer using a thermal head KST type (trade name, manufactured by Kyocera Corp.) by adjusting the applied voltage and the pulse width. A yellow image was recorded so that the density of the copy was 0.5.

Then, the yellow thermosensitive coloring layer was photo-fixed by exposing it to an ultraviolet lamp having an emission center wavelength of 420 nm and an output of 40 W for 10 seconds, and then the recording heat energy of the thermal head was adjusted by an applied voltage and a pulse width. A magenta image was recorded so that the density of the image portion measured with a Macbeth densitometer was 0.5.

Next, with an emission center wavelength of 365 nm, output 4
It was exposed to a 0 W ultraviolet lamp for 30 seconds, and the magenta thermosensitive coloring layer was optically fixed. After that, the recording heat energy of the thermal head was adjusted by the applied voltage and the pulse width, and the density of the image part measured by the McBell densitometer was 0.5. A cyan image was recorded so that

As a result, in addition to the yellow, magenta, and cyan color-developed images, the image portion where the yellow and magenta recordings overlap is red, the image portion where the magenta and cyan recordings overlap is blue, and the yellow and cyan images. The overlapping portions of the recordings of # 1 and # 2 were colored green, and the portions of the image where the recordings of yellow, magenta and cyan were overlapped were colored black. [Example 14] A full-color multilayer multicolor heat-sensitive recording material was obtained in the same manner as in Example 13 except that the electron-donating colorless dye of Example 13 (Compound Example 8 of the invention) was replaced with Compound Example 9 of the invention. Then, it is referred to as Example 14. Image recording was performed in the same manner as in Example 13. [Comparative Example 5] A full-color multilayer multicolor heat-sensitive recording material was obtained in the same manner as in Example 13 except that the electron donating colorless dye of Example 13 (Compound Example 8 of the invention) was replaced with Comparative Compound B-2. Comparative Example 5 was obtained. Image recording was performed in the same manner as in Example 13.

The images obtained in Examples 13 to 14 and Comparative Example 5 were irradiated with light by a xenon fade meter for 24 hours in the same manner as in Example 9 to evaluate the light resistance of the images. The results are shown in Table 6 below.

[0099]

[Table 6]

As is clear from Table 6, the indolylphthalide compound of the present invention showed high image light fastness even when used in a full-color multi-layered multicolor heat-sensitive recording material. On the other hand, it was found that the indolyl phthalide compounds of Comparative Examples had insufficient image light fastness.

[0101]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain an electron-donating colorless dye which gives a blue to cyan image of good density and has good fastness to light in the image area, and a recording material using the same.

Claims (2)

[Claims] 1. An indolyl represented by the following general formula (I):
Phthalide compounds. Embedded imageWhere R¹ Represents an alkyl group or a phenyl group. R^Two Is
Represents a hydrogen atom or an alkyl group. R^Three Is an alkoxy group,
Alkyl group, acylamino group, alkylthio group, acetyl
Represents a luoxy group, a phenoxy group or a halogen atom.
R^Four Represents an alkyl group. R^Five Is an alkyl group or phenyl
Represents a hydroxyl group. R⁶ , R⁷ Are each independently a hydrogen atom,
Group, an alkoxy group or a halogen atom. here,
R¹ And R ⁶And may form a ring with each other. R⁸ Is
Hydrogen atom, alkyl group, alkoxy group or halogen atom
Represents R⁹ Is a hydrogen atom, alkyl group, or alkoxy group.
Or represents a halogen atom. Ring A is represented by the following formula
Represents either Embedded image 2. An electron-donating colorless dye and an electron-accepting compound
In the recording material using, represented by the general formula (I)
At least one or more indolyl phthalide compound
A recording material characterized by the following. Embedded imageWhere R¹ Represents an alkyl group or a phenyl group. R^Two Is
Represents a hydrogen atom or an alkyl group. R^Three Is an alkoxy group,
Alkyl group, acylamino group, alkylthio group, acetyl
Represents a luoxy group, a phenoxy group or a halogen atom.
R^Four Represents an alkyl group. R^Five Is an alkyl group or phenyl
Represents a hydroxyl group. R⁶ , R⁷ Are each independently a hydrogen atom,
Group, an alkoxy group or a halogen atom. here,
R¹ And R ⁶And may form a ring with each other. R⁸ Is
Hydrogen atom, alkyl group, alkoxy group or halogen atom
Represents R⁹ Is a hydrogen atom, alkyl group, or alkoxy group.
Or represents a halogen atom. Ring A is represented by the following formula
Represents either Embedded image