JP2005125733A - Heat sensitive recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat sensitive recording material having an ink jet recording suitability on a rear surface side of a support and to particularly provide a heat sensitive recording material having an ink jet recording surface which has a heat sensitive coloring layer including a high recording sensitivity and excellent light fastness and including an excellent coloring nature and ink absorbency. <P>SOLUTION: The heat sensitive recording material includes a heat sensitive coloring layer containing a colorless or pale basic colorless dye and an organic developer as main components on one surface of the support, and an ink jet recording layer on the other surface. The heat sensitive recording material having a Cobb water absorbing capacity on a front surface of the support of the side having the ink jet recording layer of 30 g/m<SP>2</SP>or more is used. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat-sensitive recording material excellent in ink jet recording suitability on the back surface.

In general, a heat-sensitive recording material having a heat-sensitive coloring layer mainly composed of a colorless or light-colored dye precursor and a color developer that reacts with the dye precursor when heated is widely put into practical use. A thermal printer with a built-in thermal head is used for recording on this thermal recording medium, but such a thermal recording method has no noise during recording as compared with other recording methods that have been put to practical use. With the development of the information industry, with the development of the information industry, development and fixing are not necessary, maintenance is free, the equipment is relatively inexpensive and compact, and the resulting color development is very clear. Widely used for various measuring instruments and labels.
With the diversification and high performance of these recording apparatuses, the required quality for thermal recording media has become higher. With respect to the color development sensitivity, it is required that a clear color image with a high density can be obtained even with a small amount of heat energy as the apparatus is miniaturized and the recording speed is increased. In addition, thermal recording media have storage stability of color images against natural environments such as heat, water, humidity, and light as well as body fats or oils, plasticizers, solvents, etc. In addition, a good ground color is required. Among these required qualities, it is particularly difficult to impart image stability to light to a thermal recording material.
Various improvements have been made to the color image resistance, and it can be used for long-term storage and in severe storage conditions (for example, stability over time, temperature and humidity resistance, water resistance, chemical resistance, and abrasion resistance). What can be tolerated has been put into practical use. As a result, the method of use is not limited to the mere information recording area, and the image resistance is improved, so that information can be held, and the recording body itself can be used as a cash voucher.

When such heat-sensitive recording media are used for voucher applications, plastics for synthetic leather used in human hand oils and wallets are often in contact with each other, and the color-development image is significantly discolored. Moreover, since the color image needs to be clear even after long-term storage, the thermal response is good and the storage stability of the color image is also desired. However, in conventional heat-sensitive recording media, it is particularly difficult to impart image stability to light, and sufficient quality with a good balance of color development sensitivity and image storage stability is not obtained.
In addition, when applying thermal recording media to gold vouchers such as tickets, voting tickets, securities, receipt documents, etc., it is required to input a lot of information or to check the authenticity of issued tickets easily. ing. For example, in the case of a lottery ticket such as a lottery ticket, variable information such as a serial number is printed in advance in the ticket processing process in order to prevent forgery and falsification. In recent years, ink jet recording methods have begun to spread as printing means for such information, and there is an increasing demand for a thermal recording material having ink jet recording suitability. For example, Patent Documents 1 and 2 describe a thermal recording material having ink jet recording suitability on the back surface.
JP 2000-203163 A JP 2000-318319 A

However, since these are inherently heat-sensitive recording media, they may be exposed to rain outdoors or used under high humidity, causing the phenomenon that the ink image in the printing section bleeds (feathering), and the ink image density is low. In addition, problems such as ink flowing out when wet are likely to occur, and water resistance that can withstand this is required. Recording media used in the ink jet recording method are roughly classified into a plain paper type whose texture is similar to a so-called high-quality paper and a coated paper type having an ink jet recording layer (ink receiving layer). Of these, the plain paper type inkjet recording medium is not provided with an ink receiving layer or very little if provided, and is suitable for general writing such as an electrophotographic recording method, a pencil, a pen, etc., and is also inexpensive in terms of cost. It is.
However, since the plain paper type ink jet recording medium does not have an ink receiving layer, the fibers on the paper surface are exposed, and thus feathering is likely to occur. In order to prevent the occurrence of feathering, it is conceivable to increase the size of the paper and suppress the spread of the ink, or to increase the smoothness of the paper surface by containing a high amount of filler, but the former absorbs the ink. There is a problem of contamination due to contact with the recording device, other media, hands, etc., or bleeding (bleeding) at the boundary between different colors in multi-color printing. In addition, there is a problem that the transportability is lowered with the smoothing.

  An object of the present invention is to provide a thermosensitive recording medium having ink jet recording suitability on the back side of a support. In particular, it is an object of the present invention to provide a heat-sensitive recording material in which a heat-sensitive color developing layer has a high recording sensitivity and excellent light resistance, and has an ink jet recording surface excellent in color developing properties and ink absorbability on the back surface.

As a result of intensive studies by the present inventors, the above-described problem has a thermosensitive coloring layer containing a colorless or pale basic colorless dye and a developer as main components on one side of the substrate, and the substrate is thermally colored. It is found that an ink jet recording layer containing a pigment and a binder is provided on the opposite surface of the layer, and that the Cobb water absorption of the surface on which the ink jet recording layer is applied is 30 g / m ² or more. The present invention has been reached.
That is, the gist of the present invention is to provide a thermosensitive coloring layer containing a colorless or pale basic colorless dye and an organic developer as main components on one surface of a support, and an ink jet recording layer on the other surface. In the provided thermal recording medium, the Cobb water absorption of the support surface on the side where the inkjet recording layer is provided is 30 g / m ² or more. And it is preferable that a thermosensitive coloring layer contains the compound represented by following General formula (1) and / or General formula (2) as an organic color developer.

[Wherein, R _a and R _b each independently represent a hydrogen atom or a C1 to C6 alkyl group, A represents an integer of 1 to 6, B represents 0, 1 or 2, m ₁ and m < ₂ > represents the integer of 0 or 1-3 each independently. However, m ₁ and m ₂ are not 0 at the same time. R _c and R _d each independently represents a nitro group, a carboxyl group, a halogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl group, and m ₃ and m ₄ are each independently 0, 1 Or an integer of 2 and when m ₃ and m ₄ are each 2, R _c and R _d may be different from each other, and M is CO or NR _e CO (wherein R _e is a hydrogen atom or C 1 Represents a C6 alkyl group. However, when M is CO, m ₁ is 1, and when m ₁ is 0 and M is NR _e CO, B is not 0. ]

〔式中、Ｘ、Ｙは各々相異なってもよく直鎖または分枝を有してもよい炭素数１〜１２の飽和、不飽和あるいはエーテル結合を有してもよい炭化水素基を表す、または、

[In the formula, X and Y each represent a hydrocarbon group which may have a saturated, unsaturated or ether bond having 1 to 12 carbon atoms which may be different from each other and may have a straight chain or a branch; Or

もしくは、

Or

（Ｒはメチレン基またはエチレン基を表し、Ｔは水素原子、Ｃ_１〜Ｃ_４のアルキル基を表す）を表す。
Ｒ_１〜Ｒ_６はそれぞれ独立にハロゲン原子、Ｃ_１〜Ｃ_６のアルキル基、アルケニル基を示す。またｍ、ｎ、ｐ、ｑ、ｒ、ｔは０〜４までの整数を表し、２以上の時、Ｒ_１〜Ｒ_６は、それぞれ異なっていてもよい。ａは０〜１０の整数を表す。〕

(R represents a methylene group or an ethylene group, T is hydrogen _atom, an alkyl group of C 1 -C ₄₎ represents a.
R _{1 to} R ₆ each independently represent a halogen atom, a C _{1 to} C ₆ alkyl group or an alkenyl group. M, n, p, q, r, and t represent integers from 0 to 4, and when 2 or more, R _{1 to} R ₆ may be different from each other. a represents an integer of 0 to 10. ]

  The thermosensitive coloring layer is a metal chelate type of a higher fatty acid metal double salt having 16 to 35 carbon atoms as an electron acceptor and a polyvalent hydroxyaromatic compound represented by the following general formula (2) as an electron donor. It is preferable to contain a coloring component.

ただし、式中，ＲはＣ_１８〜Ｃ_３５のアルキル基、

However, in the formula, R is an alkyl group of _C 18 _{-C 35,}

のいずれかを表す。（Ｒ_１はＣ_１８〜Ｃ_３５のアルキル基を示す。）
ｎは２または３の整数、−Ｘ−は

Represents one of the following. (R ₁ represents a C ₁₈ -C ₃₅ alkyl group.)
n is an integer of 2 or 3, -X- is

のいずれかを表す。（Ｒ’はＣ_１８〜Ｃ_３５のアルキル基を示す。）

Represents one of the following. (R ′ represents a C ₁₈ -C ₃₅ alkyl group.)

  The reason why an excellent effect is obtained in the thermosensitive coloring layer of the present invention has not been clearly elucidated, but the developer represented by the general formula (1) and / or the general formula (2) defined in the present invention is used. When used, it is considered that the stability of the charge transfer complex, which is a reaction product of the dye and the developer, to light increases. In the present invention, the heat-sensitive color developing layer contains a leuco-type color component and a chelate-type color component at the same time, so that the basic leuco dye can be an organic developer and an electron donor depending on the applied energy. It reacts with the higher fatty acid metal double salt which is a compound, and these four kinds of compounds form a molten complex, thereby forming a very stable recorded image that is unlikely to dissociate even when contacted with oil or plasticizer. it is conceivable that.

  As is apparent from the above explanation, the thermosensitive coloring layer of the present invention has excellent color developing sensitivity and extremely excellent light resistance, and the ink jet recording layer on the back surface has excellent color developing properties and ink absorbability. Play.

As the support used in the present invention, uncoated paper (base paper) made of wood cellulose fibers is mainly used, and this paper is mainly composed of papermaking pulp. Examples of the papermaking pulp include chemical pulps such as LBKP and NBKP, mechanical pulps such as GP and TMP, and used paper pulp. However, the present invention is not particularly limited to these, and these are used as necessary. It can be used alone or in combination. Furthermore, if necessary, other vegetable fibers, synthetic fibers, or inorganic fibers can be blended.
Fillers to be added to the base paper include heavy calcium carbonate, light calcium carbonate, magnesium carbonate, calcium / magnesium carbonate, kaolin, calcined clay, bentonite, sericite, zeolite, talc and other natural silicates, synthetic aluminum silicate Synthetic silicates such as synthetic calcium silicate, silicic acid such as diatomaceous earth and synthetic silica, aluminum hydrates such as aluminum hydroxide and pseudoboehmite, and known fillers such as calcium sulfate, titanium dioxide, and zinc oxide can be used. Of these, talc, kaolin, calcium carbonate, titanium dioxide and the like are usually used.
In addition, various internal additives such as a sizing agent and a paper strength enhancer are not particularly limited, and can be appropriately selected from known internal additives. Further, if necessary, an antifoaming agent, a pH adjusting agent, a surfactant, a dye or colored pigment for adjusting the hue, a fluorescent dye for improving visual whiteness, or the like can be internally added.

  The ink jet recording layer of the present invention contains a pigment and a binder. Synthetic silica is generally used as the pigment, but in addition, alumina, alumina hydrate (alumina sol, colloidal alumina, pseudoboehmite, etc.), aluminum silicate, magnesium silicate, magnesium carbonate, light calcium carbonate, heavy calcium carbonate, In addition to inorganic pigments such as kaolin, talc, calcium sulfate, titanium dioxide, zinc oxide, zinc carbonate, calcium silicate, and aluminum hydroxide, organic pigments such as plastic pigments and urea resins can also be used.

In the ink jet recording layer, a binder is used in order to maintain the properties as a coating film. Examples of such a binder include polyvinyl alcohol and modified products thereof, vinyl acetate, oxidized starch, etherified starch, casein, gelatin, soy protein, carboxymethyl cellulose, SB latex, NB latex, acrylic latex, ethylene vinyl acetate type Latex, polyurethane, unsaturated polyester resin and the like can be used. In this invention, although at least 1 sort (s) of these binders can be used, it is preferable that the compounding part number is 5-60 weight part with respect to 100 weight part of above-described pigments. When the number of blended parts of the binder is small, the surface strength is insufficient, and when it is too large, the ink absorbability is insufficient. The ink jet recording layer is constituted by applying a coating liquid containing the above pigment and binder.
In the present invention, two or more ink jet recording layers may be provided. It is preferable to provide two or more ink jet recording layers because glossiness can be easily adjusted. If the coating amount of the ink jet recording layer is too small, the ink solvent is not sufficiently absorbed, so that bleeding is noticeable particularly in an image in a mixed color system. In addition, if the coating amount of the ink jet recording layer is too large, the coated layer may fall into a powder form from the support or be rubbed on the printed part when making a flat plate of the wound one or making a small judgment. Since the surface strength becomes insufficient, such as the coating layer falling off, it is not preferable. The coating amount of the inkjet recording layer can be appropriately set according to the purpose, but the preferable coating amount per layer of the inkjet recording layer is 3 to 20 g / m ² , and the particularly preferable coating amount is 5 to 15 g / m ^2. It is.

The ink jet recording layer of the present invention further includes a pigment dispersant, a thickener, an antifoaming agent, an antifoaming agent, a release agent, a foaming agent, a coloring dye, a coloring pigment, a fluorescent dye, an ultraviolet absorber, and an antioxidant. An agent, an antiseptic, a water resistant agent, a surfactant, a wet paper strength enhancer, and the like can be appropriately added as long as the effects of the present invention are not impaired.
In order to provide an inkjet recording layer on the surface of the support, various types of coating machines such as blade coaters, roll coaters, air knife coaters, bar coaters, gate roll coaters, curtain coaters, short dwell coaters, gravure coaters, flexographic gravure Various devices such as coaters and size presses can be used on-machine or off-machine.
In the present invention, the surface of the support or the ink jet recording layer can be surface-treated with a calendar device such as a machine calendar, a super calendar, or a soft calendar within a range that does not impair the effects of the present invention. The water absorption on the surface of the ink jet recording layer is 30 g / m ² or more. When the water absorption of the cup is 30 g / m ² or more, sufficient color developability and ink absorbency can be obtained even when high-speed printing is performed on the ink jet recording layer provided on the surface using a multicolor ink with an ink jet recording printer. On the other hand, if it is less than 30 g / m ² , the ink cannot be sufficiently absorbed into the support, and the heat-sensitive color-developing layer on the opposite surface side may be adversely affected or bleeding may occur at the boundary of each color ink. .

    The heat-sensitive color developing layer of the present invention has, for example, a basic colorless dye (dye precursor), a compound (developer) represented by the general formula (1) and / or (2), or a carbon number of 16 as an electron acceptor. It contains a metal chelate color-developing component of a higher fatty acid double salt of ˜35 and a polyvalent hydroxyaromatic compound represented by the above general formula (3) as an electron donor. 4) a compound (sensitizer) represented by general formula (5) to (7) or a copolymer of glycidyl methacrylate and a vinyl monomer (average molecular weight 9000 to 11000, epoxy equivalent 300 to 600, melting point 110 ° C. 1) (Image stabilizer) among the compounds represented by the following) are mixed with a dispersion in which each is dispersed together with a binder, and other necessary additives such as fillers are added to prepare a heat-sensitive color developing layer coating solution. By forming a thermosensitive coloring layer by coating and drying on a substrate, it is possible to produce a heat-sensitive recording material of the present invention.

In the present invention, a leuco-colored basic colorless dye is used as a colorless or light-colored basic colorless dye (dye precursor). As the leuco color-forming basic colorless dye, all known ones in the field of conventional pressure-sensitive or heat-sensitive recording paper can be used and are not particularly limited, but include triphenylmethane compounds, fluoran compounds, Fluorene-based and divinyl-based compounds are preferable. Specific examples of typical ones are shown below. These dye precursors may be used alone or in combination of two or more.
<Triphenylmethane leuco dye>
3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone)
3,3-bis (p-dimethylaminophenyl) phthalide (also known as malachite green lactone)

<Fluoran leuco dye>
3-diethylamino-6-methylfluorane 3-diethylamino-6-methyl-7-anilinofluorane 3-diethylamino-6-methyl-7- (o, p-dimethylanilino) fluorane 3-diethylamino-6-methyl -7-chlorofluorane 3-diethylamino-6-methyl-7- (m-trifluoromethylanilino) fluorane 3-diethylamino-6-methyl-7- (o-chloroanilino) fluorane 3-diethylamino-6-methyl- 7- (p-chloroanilino) fluorane 3-diethylamino-6-methyl-7- (o-fluoroanilino) fluorane 3-diethylamino-6-methyl-7- (m-methylanilino) fluorane 3-diethylamino-6-methyl- 7-n-octylanilinofluorane 3-diethylamino- 6-methyl-7-n-octylaminofluorane 3-diethylamino-6-methyl-7-benzylanilinofluorane 3-diethylamino-6-methyl-7-dibenzylanilinofluorane 3-diethylamino-6-chloro -7-methylfluorane 3-diethylamino-6-chloro-7-anilinofluorane 3-diethylamino-6-chloro-7-p-methylanilinofluorane 3-diethylamino-6-ethoxyethyl-7-anilino Fluorane 3-diethylamino-7-methylfluorane 3-diethylamino-7-chlorofluorane 3-diethylamino-7- (m-trifluoromethylanilino) fluorane 3-diethylamino-7- (o-chloroanilino) fluorane 3- Diethylamino-7- (p-chloroanilino) fluor 3-diethylamino-7- (o-fluoroanilino) fluorane 3-diethylamino-benzo [a] fluorane 3-diethylamino-benzo [c] fluorane 3-dibutylamino-6-methyl-fluorane 3-dibutylamino-6 Methyl-7-anilinofluorane 3-dibutylamino-6-methyl-7- (o, p-dimethylanilino) fluorane

3-dibutylamino-6-methyl-7- (o-chloroanilino) fluorane 3-dibutylamino-6-methyl-7- (p-chloroanilino) fluorane 3-dibutylamino-6-methyl-7- (o-fluoroani) Lino) fluorane 3-dibutylamino-6-methyl-7- (m-trifluoromethylanilino) fluorane 3-dibutylamino-6-methyl-7-chlorofluorane 3-dibutylamino-6-ethoxyethyl-7- Anilinofluorane 3-dibutylamino-6-chloro-7-anilinofluorane 3-dibutylamino-6-methyl-7-p-methylanilinofluorane 3-dibutylamino-7- (o-chloroanilino) fluorane 3-dibutylamino-7- (o-fluoroanilino) fluorane 3-di-n-pentylamino- 6-Methyl-7-anilinofluorane 3-di-n-pentylamino-6-methyl-7- (p-chloroanilino) fluorane 3-di-n-pentylamino-7- (m-trifluoromethylanilino ) Fluorane 3-di-n-pentylamino-6-chloro-7-anilinofluorane 3-di-n-pentylamino-7- (p-chloroanilino) fluorane 3-pyrrolidino-6-methyl-7-anilino Fluorane 3-piperidino-6-methyl-7-anilinofluorane

3- (N-methyl-N-propylamino) -6-methyl-7-anilinofluorane 3- (N-methyl-N-cyclohexylamino) -6-methyl-7-anilinofluorane 3- (N -Ethyl-N-cyclohexylamino) -6-methyl-7-anilinofluorane 3- (N-ethyl-N-xylamino) -6-methyl-7- (p-chloroanilino) fluorane 3- (N-ethyl- p-Toluidino) -6-methyl-7-anilinofluorane 3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluorane 3- (N-ethyl-N-isoamylamino) -6-chloro-7-anilinofluorane 3- (N-ethyl-N-tetrahydrofurfurylamino) -6-methyl-7-anilinofluorane 3- (N-ethyl-N-isobutane) Ruamino) -6-methyl-7-anilinofluorane 3- (N-ethyl-N-ethoxypropylamino) -6-methyl-7-anilinofluorane 3-cyclohexylamino-6-chlorofluorane 2- ( 4-oxahexyl) -3-dimethylamino-6-methyl-7-anilinofluorane 2- (4-oxahexyl) -3-diethylamino-6-methyl-7-anilinofluorane 2- (4-oxa (Hexyl) -3-dipropylamino-6-methyl-7-anilinofluorane 2-methyl-6-p- (p-dimethylaminophenyl) aminoanilinofluorane 2-methoxy-6-p- (p- Dimethylaminophenyl) aminoanilinofluorane 2-chloro-3-methyl-6-p- (p-phenylaminophenyl) aminoanilinofluorane 2 -Chloro-6-p- (p-dimethylaminophenyl) aminoanilinofluorane

2-nitro-6-p- (p-diethylaminophenyl) aminoanilinofluorane 2-amino-6-p- (p-diethylaminophenyl) aminoanilinofluorane 2-diethylamino-6-p- (p-diethylamino) Phenyl) aminoanilinofluoran 2-phenyl-6-methyl-6-p- (p-phenylaminophenyl) aminoanilinofluoran 2-benzyl-6-p- (p-phenylaminophenyl) aminoanilinofluor Oran 2-hydroxy-6-p- (p-phenylaminophenyl) aminoanilinofluorane 3-methyl-6-p- (p-dimethylaminophenyl) aminoanilinofluorane 3-diethylamino-6-p- ( p-diethylaminophenyl) aminoanilinofluorane 3-diethylamino-6-p- (p Dibutyl aminophenyl) amino-anilinofluoran 2,4-dimethyl-6 - [(4-dimethylamino) anilino] - fluoran

<Fluorene leuco dye>
3,6,6'-tris (dimethylamino) spiro [fluorene-9,3'-phthalide] 3,6,6'-tris (diethylamino) spiro [fluorene-9,3'-phthalide]

<Divinyl leuco dye>
3,3-bis- [2- (p-dimethylaminophenyl) -2- (p-methoxyphenyl) ethenyl] -4,5,6,7-tetrabromophthalide 3,3-bis- [2- ( p-dimethylaminophenyl) -2- (p-methoxyphenyl) ethenyl] -4,5,6,7-tetrachlorophthalide 3,3-bis- [1,1-bis (4-pyrrolidinophenyl) ethylene -2-yl] -4,5,6,7-tetrabromophthalide 3,3-bis- [1- (4-methoxyphenyl) -1- (4-pyrrolidinophenyl) ethylene-2-yl]- 4,5,6,7-tetrachlorophthalide

<Others>
3- (4-Diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide 3- (4-diethylamino-2-ethoxyphenyl) -3- (1 -Octyl-2-methylindol-3-yl) -4-azaphthalide 3- (4-cyclohexylethylamino-2-methoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4- Azaphthalide 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide 3,6-bis (diethylamino) fluorane-γ- (3'-nitro) anilinolactam 3,6-bis (diethylamino) Fluorane-γ- (4′-nitro) anilinolactam 1,1-bis- [2 ′, 2 ′, 2 ″, 2 ″ -tetrakis- (p-dimethylaminopheny L) -ethenyl] -2,2-dinitrileethane 1,1-bis- [2 ′, 2 ′, 2 ″, 2 ″ -tetrakis- (p-dimethylaminophenyl) -ethenyl] -2-β -Naphthoylethane 1,1-bis- [2 ', 2', 2 ", 2" -tetrakis- (p-dimethylaminophenyl) -ethenyl] -2,2-diacetylethane bis- [2,2,2 ', 2'-tetrakis- (p-dimethylaminophenyl) -ethenyl] -methylmalonic acid dimethyl ester

  As the organic developer used in the heat-sensitive recording material of the present invention, a conventionally known developer that develops a colorless or pale basic colorless dye can be used. Examples of the color developer include bisphenol A, 4-hydroxybenzoic acid esters, 4-hydroxyphthalic acid diesters, and phthalic acid monoesters described in JP-A-3-207688 and JP-A-5-24366. Esters, bis- (hydroxyphenyl) sulfides, 4-hydroxyphenylaryl sulfones, 4-hydroxyphenylaryl sulfonates, 1,3-di [2- (hydroxyphenyl) -2-propyl] -benzenes, Examples include 4-hydroxybenzoyloxybenzoate, bisphenol sulfones and the like, but are not limited thereto.

In the present invention, it is particularly preferable to use the compound represented by the general formula (1) and / or the general formula (2) as a developer. Among these, in general formula (1), a compound in which M is NR _e CO is preferable, and a compound in which M is NHCO is more preferable. Examples of the compound represented by the general formula (1) include compounds described in International Publication WO 02/081229 or JP-A No. 2002-301873.
Examples of such compounds include N- (2′-hydroxyphenylthio) acetyl-2-hydroxyaniline, N- (2′-hydroxyphenylthio) acetyl-3-hydroxyaniline, N- (2′-hydroxyphenylthio). ) Acetyl-4-hydroxyaniline, N- (3′-hydroxyphenylthio) acetyl-2-hydroxyaniline, N- (3′-hydroxyphenylthio) acetyl-3-hydroxyaniline, N- (3′-hydroxyphenyl) Thio) acetyl-4-hydroxyaniline, N- (4′-hydroxyphenylthio) acetyl-2-hydroxyaniline, N- (4′-hydroxyphenylthio) acetyl-3-hydroxyaniline, N- (4′-hydroxy) Phenylthio) acetyl-4-hydroxyaniline and the like. The present invention is not limited to, et al. Moreover, the compound represented by General formula (1) can also be used 1 type or in mixture of 2 or more types.

  In particular, N- (4′-hydroxyphenylthio) acetyl-4-hydroxyaniline represented by the following formula (1-1) and N- (4′-hydroxyphenylthio) represented by (1-2) Acetyl-2-hydroxyaniline is preferably used, and a 1: 1 mixture of these is more preferred. Such a mixture is available as, for example, Nippon Soda Co., Ltd. trade name D-100.

In the present invention, it is also preferable to use a diphenylsulfone type compound represented by the general formula (2) as a developer.
The compound represented by the general formula (2) is described in JP-A-10-29969. Specific examples of the group represented by X and Y in the diphenylsulfone type compound represented by the general formula (2) include the following. Methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, methylmethylene group, dimethylmethylene Group, methylethylene group, methyleneethylene group, ethylethylene group, 1,2-dimethylethylene group, 1-methyltrimethylene group, 1-methyltetramethylene group, 1,3-dimethyltrimethylene group, 1-ethyl-4 -Methyl-tetramethylene group, vinylene group, propenylene group, 2-butenylene group, ethynylene group, 2-butynylene group, 1-vinylethylene group, ethyleneoxyethylene group, tetramethyleneoxytetramethylene group, ethyleneoxyethyleneoxyethylene Group, ethyleneo Simethyleneoxyethylene group, 1,3-dioxane-5,5-bismethylene group, 1,2-xylyl group, 1,3-xylyl group, 1,4-xylyl group, 2-hydroxytrimethylene group, 2-hydroxy 2-methyltrimethylene group, 2-hydroxy-2-ethyltrimethylene group, 2-hydroxy-2-propyltrimethylene group, 2-hydroxy-2-isopropyltrimethylene group, 2-hydroxy-2-butyltrimethylene group Groups and the like.
The alkyl group or alkenyl group of R _{1 to} R ₆ is a C1 to C6 alkyl group or a C1 to C6 alkenyl group. Specific examples include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, n-hexyl group, isohexyl group, 1-methylpentyl group, 2 -Methylpentyl group, vinyl group, allyl group, isopropenyl group, 1-propenyl group, 2-butenyl group, 3-butenyl group, 1,3-butanedienyl group, 2-methyl-2-propenyl group and the like can be mentioned.
In the present invention, the diphenylsulfone type compound represented by the general formula (2) can be used by mixing several kinds of substituents and / or different numbers of a, and the content ratio is arbitrary. The mixing method is not particularly limited, such as mixing in powder, mixing in the state of a dispersion dispersed in water or the like, and a method of simultaneously producing and containing a plurality of types of diphenylsulfone cross-linking compounds depending on production conditions.
The compound represented by the general formula (2) is a diphenylsulfone cross-linking compound described in International Publication WO 97/16420, and is a 4,4′-dihydroxydiphenylsulfone derivative, a 2,4′-dihydroxydiphenylsulfone derivative, etc. Can be obtained by reacting in the presence of a basic substance. The compound used in the present invention contains one or two or more diphenylsulfone cross-linked compounds synthesized by such means. For example, a condensate of 4,4′-dihydroxydiphenylsulfone and diethylene glycol ( Nippon Soda Co., Ltd. product name: D-90 product).

In the heat-sensitive recording material of the present invention, among the metal chelate-type color forming components used in the heat-sensitive color forming layer, the higher fatty acid metal double salt contained as an electron acceptor has a saturated or unsaturated aliphatic group having 16 to 35 carbon atoms. Means a double salt having at least two or more metal atoms as a higher fatty acid metal in the molecule. Compared with the so-called “single salt” higher fatty acid metal salt that contains only one type of metal atom in the molecule, which is conventionally used in metal chelate type thermal recording materials, it is a “double salt”. There is a clear difference in the properties.
The higher fatty acid metal double salt is synthesized by using two or more inorganic metal salts in combination when the alkali metal salt or ammonium salt of the higher fatty acid is reacted with the inorganic metal salt. Therefore, the types of metal atoms in the double salt and the mixing ratio thereof can be freely controlled during the synthesis. For example, by reacting an aqueous solution of sodium behenate with a mixed aqueous solution of ferric chloride and zinc chloride having a molar ratio of 2 to 1, iron and zinc behenate containing zinc and iron in a ratio of 2 to 1 can be obtained. .

Examples of the metal of the higher fatty acid metal double salt include polyvalent metals other than alkali metals, such as iron, zinc, calcium, magnesium, aluminum, barium, lead, manganese, tin, nickel, cobalt, copper, silver, and mercury. . Preference is given to iron, zinc, calcium, aluminum, magnesium and silver.
Examples of typical higher fatty acid metal double salts used in the present invention include the following, but are not limited thereto. These higher fatty acid metal double salts can of course be used alone, but a plurality of them may be used simultaneously.
Iron / zinc stearate, iron / zinc montanate, iron / zinc acid wax, iron / zinc behenate, iron / calcium behenate, iron / aluminum behenate, iron / magnesium behenate, silver / calcium behenate, behenic acid Silver / aluminum, silver / magnesium behenate, calcium / aluminum behenate.

In the heat-sensitive recording material of the present invention, a polyvalent hydroxyaromatic compound contained as an electron donor in the heat-sensitive color developing layer, in other words, a polyhydric phenol derivative, is dispersed in an aqueous or solvent-based binder to form a coating solution. In preparation, it is necessary to avoid reaction with the electron acceptor, and to improve solvent resistance and dispersion stability. Therefore, it is desirable to increase the number of carbon atoms of the substituents other than the color forming functional group to 18 to 35. The number of hydroxyl groups is preferably 2 or 3, and the hydroxyl groups are preferably adjacent to each other. Specific examples include the following, but are not limited thereto. Moreover, these polyhydric phenols can be used alone or in combination of two or more as required. In the formula, R and R ′ represent a C ₁₈ -C ₃₅ alkyl group.

  Furthermore, in the present invention, preferably, the thermosensitive coloring layer contains a compound represented by the following general formula (4) as a sensitizer, and general formulas (5) to (7), glycidyl methacrylate and a vinyl monomer as image stabilizers. It is preferable to contain at least one of these copolymers (average molecular weight 9000 to 11000, epoxy equivalent 300 to 600, melting point 110 ° C. or lower). This is presumably because these sensitizers and image stabilizers have good compatibility with organic developers, particularly the compounds represented by the general formula (1).

(In the formula, R ₁ represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxyl group.)

In the present invention, when the compound of the general formula (4) is used as a sensitizer, the blending amount thereof is preferably 0.01 to 10.0 parts by weight with respect to 1 part by weight of the developer. . In particular, 0.16 parts by weight or more is more preferable because high recording sensitivity can be obtained. The reason for this is that if the amount of the compound of the general formula (4) is too small, the effect of improving the recording sensitivity is difficult to appear. If the amount is too large, the heat resistance tends to decrease or the printing residue tends to increase.
The amount of the image stabilizer added is preferably 0.01 to 10.0 parts by weight with respect to 1 part by weight of the developer. More preferably, it is 0.01-5.0 weight part. If the amount is too small, the effect does not appear. If the amount is too large, the color development sensitivity tends to decrease. In the present invention, the compound represented by the general formula (2) can also be used as an image stabilizer. In this case, the amount of the compound represented by the general formula (2) is the same as that for other image stabilizers.

  In this invention, a conventionally well-known sensitizer can be used in the range which does not inhibit the desired effect with respect to the said subject. Such sensitizers include saturated fatty acid monoamide, ethylene bisamide, montanic acid wax, polyethylene wax, 1,2-di- (3-methylphenoxy) ethane, p-benzylbiphenyl, 4-biphenyl-p-tolyl ether, m -Terphenyl, 1,2-diphenoxyethane, 4,4'-ethylenedioxy-bis-benzoic acid dibenzyl ester, dibenzoyloxymethane, 1,2-di (3-methylphenoxy) ethylene, 1,2 -Diphenoxyethylene, bis [2- (4-methoxy-phenoxy) ethyl] ether, methyl p-nitrobenzoate, benzyl p-benzyloxybenzoate, di-p-tolyl carbonate, phenyl-α-naphthyl carbonate, 1 , 4-Diethoxynaphthalene, 1-hydroxy-2-naphthoic acid pheny Ester, 4-(m-methyl phenoxymethyl) can be exemplified by biphenyl, but is not particularly limited thereto.

  Further, in the present invention, 4,4′-butylidene (6-tert-butyl-3-methylphenol) is used as an image stabilizer exhibiting the oil resistance effect of a recorded image within a range that does not inhibit the desired effect on the above problems. ), 2,2'-di-t-butyl-5,5'-dimethyl-4,4'-sulfonyldiphenol, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) Butane, 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane and the like can also be added.

  As the binder used in the present invention, fully saponified polyvinyl alcohol having a polymerization degree of 200 to 1900, partially saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, butyral-modified polyvinyl alcohol, and others Modified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, styrene-maleic anhydride copolymer, styrene-butadiene copolymer and cellulose derivatives such as ethyl cellulose and acetyl cellulose, polyvinyl chloride, polyvinyl acetate, poly Acrylamide, polyacrylic ester, polyvinyl butyllar, polystyrose and their copolymers, polyamide resin, silico Resins, petroleum resins, terpene resins, ketone resins, and the Khumalo resin. These polymer substances are used by dissolving in water, alcohol, ketones, esters, hydrocarbons and other solvents, and are used in the form of emulsification or paste dispersion in water or other media. It can also be used in combination.

Examples of the filler used in the present invention include inorganic or organic fillers such as silica, calcium carbonate, kaolin, calcined kaolin, diatomaceous earth, talc, titanium oxide, and aluminum hydroxide. In addition, lubricants such as waxes, benzophenone and triazole ultraviolet absorbers, water resistance agents such as glyoxal, dispersants, antifoaming agents, antioxidants, fluorescent dyes, and the like can be used.
The amount of developer and dye used in the heat-sensitive recording material of the present invention, and the type and amount of other various components are determined according to the required performance and recording suitability, and are not particularly limited. 1 to 8 parts of developer and 1 to 20 parts of filler are used, and 5 to 25% of the total solid content of the binder is appropriate. Moreover, when it contains an electron acceptor and an electron donor, it is used about 1 to 8 parts for 1 part of the developer.

The coating liquid having the above composition is applied to an arbitrary support such as paper, recycled paper, synthetic paper, film, plastic film, foamed plastic film, and non-woven fabric, and then imparts ink jet recording suitability or ink jet recording suitability. The desired heat-sensitive recording material can be obtained by coating on an arbitrary support such as paper, recycled paper, synthetic paper, film, plastic film, foamed plastic film, and nonwoven fabric. Moreover, you may use the composite sheet which combined these as a support body.
Furthermore, an overcoat layer such as a polymer substance can be provided on the thermosensitive coloring layer for the purpose of enhancing the storage stability. In addition, an undercoat layer such as a polymer material containing a filler can be provided under the heat-sensitive color developing layer for the purpose of increasing the color developing sensitivity.
The aforementioned organic developer, basic colorless dye, and materials to be added as necessary are finely pulverized to a particle size of several microns or less with a pulverizer such as a ball mill, an attritor or a sand grinder or an appropriate emulsifier. Depending on the purpose, various additive materials are added to obtain a coating solution. The application means is not particularly limited, and can be applied according to well-known conventional techniques. For example, an off-machine coating having various coaters such as an air knife coater, a rod blade coater, a bill blade coater, a roll coater, and a curtain coater. A machine or an on-machine coating machine is appropriately selected and used.
〔Example〕

Hereinafter, the present invention will be described by way of examples. In the description, parts indicate parts by weight.
[Example 1]
(Preparation of base paper)
Neutral rosin for 50 parts of pulp slurry consisting of hardwood bleached kraft pulp (freeness 350 ml C.S.F) and 50 parts of pulp slurry made of waste paper pulp (350 ml C.S.F) Twin wire with 0.16 parts of sizing agent, 0.3 parts of sulfate band, 0.7 parts of cationized starch, 13 parts of calcium carbonate, 6.5 parts of kaolin and 0.015 part of yield improver as filler A base paper having a basis weight of 80 g / m ² was prepared by paper making and drying using a type paper machine.
(Preparation of thermosensitive coloring layer)
For each material of the dye and developer, a dispersion having the following composition was prepared in advance, and wet grinding was performed with a sand grinder until the average particle size became 0.5 microns.
<Developer dispersion>
A 1: 1 mixture of N- (4′-hydroxyphenylthio) acetyl-4-hydroxyaniline and N- (4′-hydroxyphenylthio) acetyl-2-hydroxyaniline (manufactured by Nippon Soda Co., Ltd .: trade name D -100) 6.0 parts 10% polyvinyl alcohol aqueous solution 18.8 parts water 11.2 parts <dye dispersion>
3-di-n-butylamino-6-methyl-7-anilinofluorane (ODB2) 3.0 parts 10% aqueous polyvinyl alcohol solution 6.9 parts water 3.9 parts <sensitizer dispersion>
Succinic acid di (p-chlorobenzyl ester) 6.0 parts (Dainippon Ink, trade name: HS3519)
10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts

The following compositions were mixed to obtain a heat-sensitive layer coating solution. The surface of this coating solution on a base paper having a basis weight of 80 g / m ² prepared above, coating amount after drying was dried so that the 6 g / m ^2, the Bekk smoothness is 200 to 600 seconds supercalendered Thus, a heat-sensitive recording material was obtained.
Developer dispersion 36.0 parts Dye dispersion (ODB2) 13.8 parts Sensitizer dispersion 36.0 parts Kaolin clay 50% dispersion 26.0 parts Zinc stearate 30% dispersion 6.7 parts

(Preparation of inkjet recording layer)
Synthetic amorphous silica (fine seal X-37B: manufactured by Tokuyama Co., Ltd.) 40 parts as a pigment and synthetic amorphous silica (thyroid 621: manufactured by Grace Devison Co., Ltd.) 60 parts, polyvinyl alcohol ( 25 parts of PVA-117: manufactured by Kuraray Co., Ltd., 4 parts of ethylene vinyl acetate emulsion (Sumikaflex 7400: manufactured by Sumitomo Chemical Co., Ltd.) and 4 parts of styrene butadiene latex (Lx438C: manufactured by Nippon Zeon Co., Ltd.) were mixed. . Further, 2 parts of a styrene acrylic resin (Polymaron 360: manufactured by Arakawa Chemical Co., Ltd.) was added as a surface sizing agent, and 8 parts of a polyamine dye fixing agent (PAS-H-10L: manufactured by Nitto Boseki Co., Ltd.). And a dilution water was further added to prepare a color having a solid content of 20%.
Apply the above coating liquid on the surface opposite to the heat-sensitive layer coated surface on the base paper with a bar blade coater so that the coating amount is 12 g / m ² in terms of dry solids, and dry it to finish the machine calendar. Thus, a heat-sensitive recording material of Example 1 was obtained. The cup water absorption on the surface of the base paper on the side where the ink jet recording layer is provided was 55 g / m ² .

[Example 2]
In the heat-sensitive recording material of the present invention produced in Example 1, Example 1 except that oxalic acid di (p-chlorobenzyl ester) in the heat-sensitive layer sensitizer dispersion was changed to benzyloxynaphthalene (BON). Similarly, a heat-sensitive recording material of Example 2 was obtained.

[Example 3]
The stabilizer dispersion was prepared according to Example 1 as follows.
<Stabilizer dispersion>
3-{[(Phenylamino) carbonyl] amino} benzenesulfonamide (AP Corporation: trade name SU727) 1.0 part 10% aqueous polyvinyl alcohol solution 2.3 parts water 1.3 parts According to Example 1, the following formulation A heat-sensitive layer paint was prepared.
Developer dispersion 36.0 parts Dye dispersion (ODB2) 13.8 parts Sensitizer dispersion 36.0 parts Stabilizer dispersion 4.6 parts Kaolin clay 50% dispersion 26.0 parts Zinc stearate 30 % Dispersion 6.7 parts A heat-sensitive recording material of Example 3 was obtained in the same manner as in Example 1 using the above-mentioned paint.

[Example 4]
An underlayer paint was prepared as follows.
Firing kaolin (Angelex manufactured by Engelhard) 50.0 parts Styrene-butadiene copolymer latex (solid content 50%) 50.0 parts Water 50.0 parts A mixture of the above composition was mixed and stirred to obtain. The undercoating was applied to the surface of the base paper of Example 1 so that the dry coating amount was 5 g / m ^2, and the heat-sensitive layer coating material of Example 3 was applied thereon so that the dry coating amount was 5 g / m ^2. did.
Next, an overlayer paint was prepared as follows.
Aluminum hydroxide 30.0 parts Polyvinyl alcohol 10% aqueous solution 30.0 parts Water 40.0 parts The mixture having the above composition was mixed and stirred, and the resulting overcoat paint was dried onto the heat-sensitive layer in an amount of 2 g / m. ² so as to be applied, otherwise in the same manner as in example 3, to obtain a heat-sensitive recording material of example 4.

[Example 5]
In the thermosensitive recording material of the present invention prepared in Example 1, N- (4′-hydroxyphenylthio) acetyl-4-hydroxyaniline and N- (4′-hydroxy) in the developer dispersion of the thermosensitive coloring layer Except that the 1: 1 mixture of phenylthio) acetyl-2-hydroxyaniline was changed to a condensate of 4,4′-dihydroxydiphenylsulfone and diethylene glycol (manufactured by Nippon Soda Co., Ltd .: trade name D-90). A heat-sensitive recording material was obtained in the same manner as in Example 1.

[Example 6]
In the recording medium of the present invention prepared in Example 1, when preparing the thermosensitive coloring layer coating solution, chelate dispersions (1) and (2) having the following composition were prepared and the average particle size was 0.5 microns using a sand grinder. A heat-sensitive recording material was obtained in the same manner as in Example 1 except that wet pulverization was carried out until each was added.
<Chelate dispersion (1)>
Stearyl gallate 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts <Chelate dispersion (2)>
Iron / zinc behenate (2: 1) double salt 6.0 parts 10% polyvinyl alcohol aqueous solution 18.8 parts Water 11.2 parts <Composition of thermosensitive coloring layer coating solution>
Developer dispersion 36.0 parts Dye dispersion (ODB2) 13.8 parts Sensitizer dispersion 36.0 parts Chelate dispersion (1) 36.0 parts Chelate dispersion (2) 36.0 parts Kaolin clay 50% dispersion 26.0 parts Zinc stearate 30% dispersion 6.7 parts

[Comparative Example 1]
In the heat-sensitive color developing layer of Example 1, D-100 (trade name, manufactured by Nippon Soda Co., Ltd.) in the developer dispersion was changed to 4,4′-dihydroxydiphenyl sulfone (bisphenol S: BPS), and heat sensitive. A heat-sensitive recording material of Comparative Example 1 was obtained in the same manner as in Example 1 except that nothing was applied to the surface opposite to the surface having the coloring layer.

[Comparative Example 2]
On the surface opposite to the surface having the thermosensitive coloring layer of Example 1, polyvinyl alcohol (Kuraray Co., Ltd., PVA117) was coated and dried so that the coating amount was 1.5 g / m ² in terms of dry solid content. A heat-sensitive recording medium of Comparative Example 2 was obtained in the same manner as in Example 1 except that machine calendar finishing was performed.

[Comparative Example 3]
In the thermosensitive coloring layer of Comparative Example 2, except that 4,4′-dihydroxydiphenylsulfone (bisphenol S: BPS) in the developer dispersion was changed to 4,4′-isopropylidenediphenol (bisphenol A: BPA). Obtained the heat-sensitive recording material of Comparative Example 3 in the same manner as Comparative Example 2.

[Thermal recording aptitude evaluation]
The performance of the thermosensitive layers of the thermosensitive recording materials obtained in the above Examples and Comparative Examples was evaluated by the following method.
(Color development sensitivity)
Using TH-PMD manufactured by Okura Electric Co., Ltd., printing was performed on the produced thermal recording medium with an applied energy of 0.34 mJ / dot. The image density after printing was measured with a Macbeth densitometer (using an amber filter).
(Light resistance test)
Using a TH-PMD manufactured by Okura Electric Co., Ltd., a sample printed at an applied energy of 0.34 mJ / dot was processed for 24 hours at an output of 66 W / m ² using a Ci3000F type xenon fade meter manufactured by Atlas. After processing, the Macbeth density (using an amber filter) of the printed part was measured.

[Inkjet recording suitability evaluation]
The performance of the thermal recording materials obtained in the above Examples and Comparative Examples was evaluated for the backside inkjet recording suitability by the following method. In each item, if the evaluation is Δ or more, it can be put into practical use.
In addition, regarding evaluation of inkjet recording suitability, a commercially available dye ink type inkjet printer PM-950C (manufactured by Seiko Epson) was used.

(1) Cobb water absorbency Cobb water absorbency was measured by a method based on JIS P 8140 paper and paperboard-water absorption test method-Cobb method. This method is a method for testing the water absorption when one side of non-water-absorbing paper and paperboard is in contact with water for a certain period of time. In the present invention, the contact time between water and the test piece was set to 30 seconds, and the initial moisture conditioning weight of the test piece was subtracted from the weight after absorption to measure the absorbed weight (g / m ² ) per unit area. In the Cobb water absorption method, the higher the water absorption resistance (absorption resistance resistance), the smaller the absorption weight, and conversely, the lower the absorption resistance, the larger the absorption weight.
(2) Color developability Each solid image was printed for black, cyan, magenta, and yellow and allowed to stand for one day, and then the print density of each image area was measured using a reflection densitometer (MACHBETH RD914). The larger the density value of the four colors, the better the color developability.
○: The density value of the total of four colors is 6.60 or more. Δ: The density value of the total of four colors is 6.40 or more and less than 6.60. X: The density value of the total of four colors is less than 6.40 (3) Ink absorbability Each solid image of red and green was printed next to each other, and the degree of bleeding at the boundary portion was evaluated.
○: The boundary is clear and no bleeding is observed Δ: The boundary is slightly blurred but no bleeding is observed ×: The boundary is unclear and bleeding is observed

  As is apparent from the table, the heat-sensitive layers of Examples 1 to 4 of the present invention are excellent in color development sensitivity and image light resistance, and the ink jet recording layer is excellent in color development and ink absorption. On the other hand, for Comparative Example 1 using a developer other than that defined in the present invention, good quality of the thermosensitive coloring layer cannot be obtained, and Comparative Example having an ink jet recording surface other than the conditions specified in the present invention. For 1-3, good quality of the inkjet recording surface is not obtained.

Claims (5)

In the thermosensitive recording medium, a thermosensitive coloring layer containing a colorless or light-colored basic colorless dye and an organic developer as main components is provided on one side of the support, and an ink jet recording layer is provided on the other side. A heat-sensitive recording material, wherein the surface of the support on the side where the ink jet recording layer is provided has a Cobb water absorption of 30 g / m ² or more. The heat-sensitive recording material according to claim 1, wherein the ink jet recording layer contains a pigment and a binder. The thermal recording material according to claim 1 or 2, wherein the coating amount of the ink jet recording layer is 20 g / m ² or less. The said heat-sensitive coloring layer contains the compound represented by following General formula (1) and / or General formula (2) as an organic color developer, The claim in any one of Claim 1, 2, or 3 characterized by the above-mentioned. Thermal recording material.

[Wherein, R _a and R _b each independently represent a hydrogen atom or a C1 to C6 alkyl group, A represents an integer of 1 to 6, B represents 0, 1 or 2, m ₁ and m < ₂ > represents the integer of 0 or 1-3 each independently. However, m ₁ and m ₂ are not 0 at the same time. R _c and R _d each independently represents a nitro group, a carboxyl group, a halogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl group, and m ₃ and m ₄ are each independently 0, 1 Or an integer of 2 and when m ₃ and m ₄ are each 2, R _c and R _d may be different from each other, and M is CO or NR _e CO (wherein R _e is a hydrogen atom or C 1 Represents a C6 alkyl group. However, when M is CO, m ₁ is 1, and when m ₁ is 0 and M is NR _e CO, B is not 0. ]

[In the formula, X and Y each represent a hydrocarbon group which may have a saturated, unsaturated or ether bond having 1 to 12 carbon atoms which may be different from each other and may have a straight chain or a branch; Or

Or

(R represents a methylene group or an ethylene group, T is hydrogen _atom, an alkyl group of C 1 -C ₄₎ represents a.
R _{1 to} R ₆ each independently represent a halogen atom, a C _{1 to} C ₆ alkyl group or an alkenyl group. M, n, p, q, r, and t represent integers from 0 to 4, and when 2 or more, R _{1 to} R ₆ may be different from each other. a represents an integer of 0 to 10. ] The thermosensitive coloring layer further comprises a metal chelate type of a higher fatty acid metal double salt having 16 to 35 carbon atoms as an electron acceptor and a polyvalent hydroxyaromatic compound represented by the following general formula (3) as an electron donor. The heat-sensitive recording material according to claim 1, 2, 3, or 4, further comprising a coloring component.

However, in the formula, R is an alkyl group of _C 18 _{-C 35,}

Represents one of the following. (R ₁ represents a C ₁₈ -C ₃₅ alkyl group.)
n is an integer of 2 or 3, -X- is

Represents one of the following. (R ′ represents a C ₁₈ -C ₃₅ alkyl group.)