WO2022024971A1 - Heat-sensitive recording material - Google Patents

Abstract

[Problem] To provide a heat-sensitive recording material which is excellent in terms of printing runnability among various properties required for heat-sensitive recording materials.　[Solution] A heat-sensitive recording material which is obtained by arranging, on a support, a heat-sensitive recording layer that contains a colorless or pale-colored electron-donating leuco dye and an electron-accepting developer, wherein: the heat-sensitive recording layer contains, as the electron-accepting developer, a urea compound represented by general formula (1) and a urea urethane compound represented by general formula (2); and the content (solid content) of the urea urethane compound in the heat-sensitive recording layer is 4 parts by weight or less relative to 1 part by weight of the urea compound. (In the formulae, each of R¹ to R⁵ represents a hydrogen atom, an alkyl group or the like; and m represents an integer from 0 to 2.)

Description

Thermal recording body

The present invention utilizes a color-developing reaction between a colorless or light-colored electron-donating leuco dye (hereinafter, also referred to as “leuco dye”) and an electron-accepting color developer (hereinafter, also referred to as “color developer”). The present invention relates to a heat-sensitive recorder which is a heat-sensitive recorder and has excellent printability.

In general, a heat-sensitive recorder is obtained by applying a coating liquid containing a leuco dye and a color developer, which are usually colorless or light-colored, to a support such as paper, synthetic paper, film, or plastic, and is used for a thermal head or hot. A recorded image is obtained by developing a color by an instant chemical reaction by heating with a stamp, a heat pen, a laser beam, or the like. Thermal recorders are widely used as recording media such as facsimiles, computer terminal printers, automatic ticket vending machines, measurement recorders, and receipts in supermarkets and convenience stores.
In recent years, heat-sensitive recorders have been expanded to various applications such as various tickets, receipts, labels, bank ATMs, gas and electric meter readings, and gold tickets such as car betting tickets. Therefore, they are water resistant. Various performances such as plasticizer resistance of the image part, heat resistance of the blank part, oil resistance, and storage stability of the image part and the blank part under harsh conditions have been required.
In response to such demands, by using a specific urea urethane compound as a color developer or a combination of this urea urethane compound and another color developer, color development performance, plasticizer resistance of an image portion, and a blank sheet portion are used. By using a heat-sensitive recorder (Patent Documents 1 to 3) with improved heat resistance, a specific urethane compound as a color developer, and a combination of this urethane compound and another color developer, water resistance can be achieved. A heat-sensitive recorder (Patent Documents 4 to 6) having improved heat resistance, moisture resistance, and the like is disclosed.

Japanese Patent Application Laid-Open No. 2000-143611 JP-A-2002-178645 JP-A-2004-223871 International release WO2017 / 111032 JP-A-2020-04287 JP-A-2020-04286

Therefore, an object of the present invention is to provide a heat-sensitive recording body having excellent printability among various performances required for the heat-sensitive recording body.

As a result of diligent studies, the present inventors have found that the above-mentioned problems can be solved by containing at least two kinds of specific color-developing agents in the heat-sensitive recording layer, and have completed the present invention.
That is, the present invention is a heat-sensitive recording body provided with a heat-sensitive recording layer containing a colorless or light-colored electron-donating leuco dye and an electron-accepting color developer on a support, and the heat-sensitive recording layer is an electron. As the accepting color developer, the urea compound represented by the following general formula (Chemical formula 1) and the urea urethane-based compound represented by the following general formula (Chemical formula 2) are contained, and the urea urethane-based compound in the heat-sensitive recording layer is contained. It is a thermal recording body in which the content (solid content) of the compound is 4 parts by weight or less with respect to 1 part by weight of the urea compound.

(In the formula, R ¹ to R ⁵ may be the same or different, respectively, and may be the same or different, hydrogen atom, halogen atom, nitro group, amino group, alkyl group, alkoxy group, aryloxy group, alkylcarbonyloxy group, aryl. It represents a carbonyloxy group, an alkylcarbonylamino group, an arylcarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, a monoalkylamino group, a dialkylamino group, or an arylamino group, and m represents an integer of 0 to 2. )

According to the present invention, it is possible to provide a heat-sensitive recording body having excellent color-developing performance and excellent printing runnability. Further, in this heat-sensitive recording body, the printed portion has excellent water resistance and the background is heat-resistant. Shows high stability. Then, in addition to the urea compound represented by the general formula (Chemical formula 1) and the urea urethane-based compound represented by the following general formula (Chemical formula 2), the heat-sensitive recording layer has a general formula (Chemical formula 1) as an electron-accepting color developer. By containing the urea compound represented by Chemical formula 8), more excellent color development performance and plasticizer resistance can be obtained.

The heat-sensitive recording material of the present invention is a heat-sensitive recording material provided with a heat-sensitive recording layer containing a colorless or light-colored leuco dye and a color developer on a support, and the heat-sensitive recording layer is a specific urea compound as a color developer. And contains certain urea urethane compounds.

The urea compound used in the present invention is represented by the following formula (formulation 1).

In the general formula (Chemical formula 1), R ¹ to R ⁵ may be the same or different, respectively, and may be the same or different, hydrogen atom, halogen atom, nitro group, amino group, alkyl group, alkoxy group, aryloxy group, alkylcarbonyl. Represents an oxy group, an arylcarbonyloxy group, an alkylcarbonylamino group, an arylcarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, a monoalkylamino group, a dialkylamino group, or an arylamino group, preferably a hydrogen atom or an alkyl. Group, alkoxy group.
In particular, R ¹ , R ² , R ⁴ , and R ⁵ are preferably hydrogen atoms, and R ³ is preferably hydrogen atoms or alkyl groups. As R3 ^, an alkyl group is particularly preferable.
The alkyl group (including those contained in an alkylcarbonyloxy group, an alkylcarbonylamino group, an alkylsulfonylamino group, a monoalkylamino group, and a dialkylamino group) may be, for example, linear, branched, or alicyclic. It is an alkyl group and preferably has 1 to 12 carbon atoms.
The alkyl group includes methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, cyclopentyl group, hexyl group, cyclohexyl group and 2-ethyl. Examples thereof include a xyl group and a lauryl group.

The aryl group (including those contained in an aryloxy group, an arylcarbonyloxy group, an arylcarbonylamino group, an arylsulfonylamino group, and an arylamino group) preferably has 6 to 12 carbon atoms.
The aryl group includes a phenyl group, a p-tolyl group, an m-tolyl group, an o-tolyl group, a 2,5-dimethylphenyl group, a 2,4-dimethylphenyl group, a 3,5-dimethylphenyl group, and 2, 3-Dimethylphenyl group, 3,4-dimethylphenyl group, mesitylene group, p-ethylphenyl group, pi-propylphenyl group, pt-butylphenyl group, p-methoxyphenyl group, 3,4-dimethoxy Unsubstituted or alkyl group such as phenyl group, p-ethoxyphenyl group, p-chlorophenyl group, 1-naphthyl group, 2-naphthyl group, t-butylated naphthyl group, alkoxy group, aralkyl group, aryl group or halogen atom. Examples include substituted aryl groups.

The alkoxy group is, for example, a linear, branched or alicyclic alkoxy group, and the number of carbon atoms is preferably 1 to 12.
When these are substituted, the substituent is preferably an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom.
The position of the -O- (CONH) _m -SO2 _- substituted phenyl group in the benzene ring of the general formula (Chemical formula 1) is preferably a 3-position, 4-position or 5-position (the following general formula (Chemical formula 3)). And the same applies to the general formula (Chemical formula 4)).
In the general formula (formula 1), m represents an integer of 0 to 2, preferably 0 to 1.

As the urea compound of the present invention, a urea compound represented by the following general formula (Chemical Formula 3) or the following general formula (Chemical Formula 4) is preferable.

The urea urethane compound used in the present invention is represented by the following general formula (Chemical Formula 2).

The urea urethane compounds used as the color developer in the present invention are specifically three types represented by the following formulas (Chemical formula 5) to (Chemical formula 7), and these are used alone or in combination of two or more. May

A mixture of three types of urea urethane compounds represented by the above chemical formulas (Chemical formulas 5) to (Chemical formula 7) (4,5'-bis (3- (phenoxycarbonylamino) methylphenylureido) diphenyl sulfone) is manufactured by Fine Ace Co., Ltd. It is available under the product name UU.

Further, it is preferable that the heat-sensitive recording layer of the present invention further contains a urea compound represented by the following general formula (Chemical Formula 8) as an electron-accepting color developer.

In the general formula (Chemical formula 8), R ⁶ is an alkyl group or an alkoxy group, preferably an alkyl group, and n represents an integer of 0 to 3, preferably 0 to 2, and more preferably 0 to 1. The number of carbon atoms of this alkyl group is, for example, 1 to 12, preferably 1 to 8, and more preferably 1 to 4.
The position of R ⁶ in the benzene ring of the general formula (Chemical formula 8) may be the same or different, and is preferably a 3-position, 4-position or 5-position, preferably 4-position.

Examples of the urea compound represented by the general formula (Chemical formula 8) include N, N'-di- [3- (benzenesulfonyloxy) phenyl] urea and N, N'-di- [3- (benzenesulfonyloxy). -4-Methyl-phenyl] urea, N, N'-di- [3- (benzenesulfonyloxy) -4-ethyl-phenyl] urea, N, N'-di- [3- (benzenesulfonyloxy) -5 -Methyl-phenyl] urea, N, N'-di- [3- (benzenesulfonyloxy) -4-propyl-phenyl] urea, N, N'-di- [3- (o-toluenesulfonyloxy) phenyl] Urea, N, N'-di- [3- (m-toluenesulfonyloxy) phenyl] urea, N, N'-di- [3- (p-toluenesulfonyloxy) phenyl] urea, N, N'-di -[3- (p-Toluenesulfonyloxy) -4-methyl-phenyl] urea, N, N'-di- [3- (p-xylenesulfonyloxy) phenyl] urea, N, N'-di- [3 -(M-Xylenesulfonyloxy) phenyl] urea, N, N'-di- [3- (methicylenesulfonyloxy) phenyl] urea, N, N'-di- [3- (p-ethylbenzenesulfonyloxy) phenyl] Urea, N, N'-di- [3- (p-propylbenzenesulfonyloxy) phenyl] urea, N, N'-di- [3- (p-isopropylbenzenesulfonyloxy) phenyl] urea, N, N' -Di- [3- (pt-butylbenzenesulfonyloxy) phenyl] urea, N, N'-di- [3- (p-methoxybenzenesulfonyloxy) phenyl] urea, N, N'-di- [ 3- (m-methoxybenzenesulfonyloxy) phenyl] urea, N, N'-di- [3- (o-methoxybenzenesulfonyloxy) phenyl] urea, N, N'-di- [3- (m, p) -Dimethoxybenzenesulfonyloxy) phenyl] urea, N, N'-di- [3- (p-ethoxybenzenesulfonyloxy) phenyl] urea, N, N'-di- [3- (p-propoxybenzenesulfonyloxy) Phenyl] urea, N, N'-di- [3- (p-butoxybenzenesulfonyloxy) phenyl] urea, N, N'-di- [4- (benzenesulfonyloxy) phenyl] urea, N, N'- Examples thereof include, but are not limited to, di- [4- (p-toluenesulfonyloxy) phenyl] urea.

The content (solid content) of the urea compound represented by the general formula (formulation 1) in the heat-sensitive recording layer of the present invention is preferably 5 to 50% by weight, more preferably 5 to 40% by weight, still more preferably. It is 8 to 30% by weight.
The content (solid content) of the urea compound represented by the general formula (Chemical Formula 8) in the heat-sensitive recording layer of the present invention is preferably 1 to 50% by weight, more preferably 1 to 40% by weight, still more preferably. Is 1 to 30% by weight.
Further, the content of the urea urethane compound in the heat-sensitive recording layer of the present invention is the same as that of the urea compound (the urea compound represented by the general formula (Chemical formula 1) and the urea compound represented by the general formula (Chemical formula 8). Total) 4 parts by weight or less, preferably 0.01 to 3 parts by weight, relative to 1 part by weight. It is more preferably 0.04 to 2 parts by weight, still more preferably 0.07 to 1 part by weight. By setting the contents of these urea compounds and urea urethane compounds in these ranges, heat resistance is particularly good in addition to printability.

The heat-sensitive recording layer of the present invention comprises the urea compound (total of the urea compound represented by the general formula (Chemical formula 1) and the urea compound represented by the general formula (Chemical formula 8)) and the urea urethane-based compound other than the above. Coloring agents may be used, and as such coloring agents, for example, inorganic acidic substances such as active white clay, attapulsite, colloidal silica, aluminum silicate, 4,4'-isopropridendiphenol, 1,1-bis. (4-Hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 4,4'-dihydroxydiphenylsulfide, hydroquinone monobenzyl ether, benzyl 4-hydroxybenzoate, 4,4' -Dihydroxydiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4-hydroxy-4'-n-propoxydiphenyl sulfone, bis (3-allyl-4-hydroxyphenyl) Sulfone, 4-hydroxy-4'-methyldiphenyl sulfone, 4-hydroxyphenyl-4'-benzyloxyphenyl sulfone, 3,4-dihydroxyphenyl-4'-methylphenyl sulfone, 1- [4- (4-hydroxyphenyl) Sulfonyl) phenoxy] -4- [4- (4-isopropoxyphenylsulfonyl) phenoxy] butane, N- [2- (3-phenylureido) phenyl] benzene sulfone amide, phenol condensation described in JP-A-2003-154760. Composition, aminobenzene sulfone amide derivative described in JP-A-8-59603, bis (4-hydroxyphenylthioethoxy) methane, 1,5-di (4-hydroxyphenylthio) -3-oxapentane, bis (p). -Hydroxyphenyl) butyl acetate, bis (p-hydroxyphenyl) methyl acetate, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,4-bis [α-methyl-α- (4'-) Hydroxyphenyl) ethyl] benzene, 1,3-bis [α-methyl-α- (4'-hydroxyphenyl) ethyl] benzene, di (4-hydroxy-3-methylphenyl) sulfide, 2,2'-thiobis ( 3-tert-octylphenol), 2,2'-thiobis (4-tert-octylphenol), WO02 / 081229 or the compound described in JP-A-2002-301873, and N, N'-di-m-chlorophenylthi. Thiourea compounds such as Aurea, p-chlorobenzoic acid, stearyl eosinate, bis [4- (n-octyloxycarbonylamino) zinc salicylate] dihydrate, 4- [2- (p-methoxyphenoxy) ethyloxy] Salicylic acid, 4- [3- (p-tolylsulfonyl) propyloxy] salicylic acid, 5- [p- (2-p-methoxyphenoxyethoxy) cumill] aromatic carboxylic acid of salicylic acid, and zinc of these aromatic carboxylic acids. , Salts with polyvalent metal salts such as magnesium, aluminum, calcium, titanium, manganese, tin, nickel, as well as antipyrine complexes of zinc thiosianate, complex zinc salts of terephthalaldehyde acid and other aromatic carboxylic acids, etc. Can be mentioned. These color developeres may be used alone or in combination of two or more. 1- [4- (4-Hydroxyphenylsulfonyl) phenoxy] -4- [4- (4-isopropoxyphenylsulfonyl) phenoxy] butane is available, for example, under the trade name JKY-214 manufactured by AP Corporation. The phenol condensation composition described in JP-A-2003-154760 is available, for example, under the trade name JKY-224 manufactured by API Corporation. Further, the compound described in WO02 / 081229 etc. is available under the trade names NKK-395 and D-100 manufactured by Nippon Soda Co., Ltd. In addition, a metal chelate-type color-developing component such as a higher fatty acid metal double salt or a polyvalent hydroxy aromatic compound described in JP-A No. 10-258577 can also be contained.

When the heat-sensitive recording layer of the present invention contains a developer other than the urea compound and the urea urethane-based compound, the total color-developing agent (the urea compound and the urea urethane-based compound) contained in the heat-sensitive recording layer may be used. The total content (solid content) of the urea compound and the urea urethane compound with respect to (including) is preferably 50% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more.

Hereinafter, various other materials used in the heat-sensitive recording layer of the heat-sensitive recording body of the present invention will be exemplified, but binders, cross-linking agents, pigments and the like are provided as necessary within a range that does not impair the desired effect on the above-mentioned problems. It can also be used for each coating layer that has been applied.

As the leuco dye used in the present invention, all conventional leuco dyes known in the field of pressure-sensitive or thermal recording paper can be used, and are not particularly limited, but are triphenylmethane-based compounds, fluorene-based compounds, and fluorene. System compounds, divinyl compounds and the like are preferable. Specific examples of typical colorless or light-colored dyes (dye precursors) are shown below. Further, 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-benzylaminofluorane , 3-diethylamino-6-methyl-7-dibenzylaminofluorane, 3-diethylamino-6-chloro-7-methylfluorine, 3-diethylamino-6-chloro-7-anilinofluorane, 3-diethylamino- 6-Chloro-7-p-methylanilinofluorane, 3-diethylamino-6-ethoxyethyl-7-anilinofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7-chlorofluorine, 3-diethylamino-7- (m-trifluoromethylanilino) fluorane, 3-diethylamino-7- (o-chloroanilino) fluorane, 3-diethylamino-7- (p-chloroanilino) fluorane, 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- Anilinofluolane, 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-fluoroanilino) fluorane, 3-dibutylamino-6-methyl-7- (m-trifluoromethyl) Anilino) Fluoran, 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-trifluoro) Methylanilino) Fluoran, 3-di-n-pentylamino-6-chloro-7-anilinofluorane, 3-di-n-pentylamino-7- (p-chloroanilino) fluorane, 3-pyrrolidino-6- Methyl-7-anilinofluolane, 3-piperidino-6-methyl-7-anilinofluoran, 3- (N-methyl-N-propylamino) -6-methyl-7-anilinofluolane, 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-isobutylamino) -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-anilino Fluoran, 2- (4-oxahexyl) -3-diethylamino-6-methyl-7-anilinofluoran, 2- (4-oxahexyl) -3-dipropylamino-6-methyl-7-anilino Fluoran, 2-methyl-6-p- (p-dimethylaminophenyl) aminoanilinofluoran, 2-methoxy-6-p -(P-Dimethylaminophenyl) Aminoanilinofluolane, 2-Chloro-3-methyl-6-p- (p-Phenylaminophenyl) Aminoanilinofluolane, 2-Chloro-6-p- (p-) Dimethylaminophenyl) Aminoanilinofluolane, 2-nitro-6-p- (p-diethylaminophenyl) aminoanilinofluolane, 2-amino-6-p- (p-diethylaminophenyl) aminoanilinofluorane, 2-diethylamino-6-p- (p-diethylaminophenyl) aminoanilinofluolane, 2-phenyl-6-methyl-6-p- (p-phenylaminophenyl) aminoanilinofluorane, 2-benzyl-6 -P- (p-Phenylaminophenyl) aminoanilinofluorane, 2-hydroxy-6-p- (p-phenylaminophenyl) aminoanilinofluorane, 3-methyl-6-p- (p-dimethylamino) Phenyl) Aminoanilinofluolane, 3-diethylamino-6-p- (p-diethylaminophenyl) aminoanilinofluolane, 3-diethylamino-6-p- (p-dibutylaminophenyl) aminoanilinofluolane, 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- Il] -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-methylindole-3-yl) -4-azaphthalide, 3- (4-cyclohexylethylamino-2-methoxyphenyl) -3- (1-ethyl-2-methylindole-3-yl)- 4-Azaphthalide, 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide, 3,6-bis (diethylamino) fluoran-γ- (3'-nitro) anilinolactam, 3,6 -Bis (diethylamino) fluorane-γ- (4'-nitro) anilinolactam, 1,1-bis- [2', 2', 2'', 2''-tetrakis- (p-dimethylaminophenyl)- Ethenyl] -2,2-dinitrile ethane, 1,1-bis- [2', 2', 2'', 2''-tetrakis- (p-dimethylaminophenyl) -ethenyl] -2-β-naphthylethane , 1,1-bis- [2', 2', 2'', 2''-tetrakis- (p-dimethylaminophenyl) -ethenyl] -2,2-diacetylethane, bis- [2,2,2 ', 2'-Tetrakiss- (p-dimethylaminophenyl) -ethenyl] -methylmalonic acid dimethyl ester

As the sensitizer used in the present invention, a conventionally known sensitizer can be used. Examples of such sensitizers include fatty acid amides such as stearate amides and palmitic acid amides, ethylene bisamides, montanic acid waxes, polyethylene waxes, 1,2-bis- (3-methylphenoxy) ethane, p-benzylbiphenyl and β-. Benzyloxynaphthalene, 4-biphenyl-p-tolyl ether, m-terphenyl, 1,2-diphenoxyetane, dibenzyl sulphate, di (p-chlorobenzyl) sulphonate, di (p-methylbenzyl) sulphonate, Dibenzyl terephthalate, benzyl p-benzyloxybenzoate, di-p-tolyl carbonate, phenyl-α-naphthyl carbonate, 1,4-diethoxynaphthalene, 1-hydroxy-2-naphthoic acid phenyl ester, o-xylene-bis -(Phenyl ether), 4- (m-methylphenoxymethyl) biphenyl, 4,4'-ethylenedioxy-bis-benzoic acid dibenzyl ester, dibenzoyloxymethane, 1,2-di (3-methylphenoxy) Examples thereof include ethylene, bis [2- (4-methoxy-phenoxy) ethyl] ether, methyl p-nitrobenzoate, phenyl p-toluenesulfonate, o-toluenesulfonamide, p-toluenesulfonamide and the like. These sensitizers may be used alone or in combination of two or more, but it is preferable to mix two or more of them because the storage stability (particularly, the plasticizer resistance) is good.

Examples of the pigment used in the present invention include kaolin, calcined kaolin, calcium carbonate, aluminum oxide, titanium oxide, magnesium carbonate, aluminum silicate, magnesium silicate, calcium silicate, aluminum hydroxide, silica and the like, depending on the required quality. It can also be used together.

The binder used in the present invention includes fully saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, acetoacetylated polyvinyl alcohol, carboxy-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, butyral-modified polyvinyl alcohol, and olefin-modified. Polyvinyl alcohol, nitrile-modified polyvinyl alcohol, pyrrolidone-modified polyvinyl alcohol, silicone-modified polyvinyl alcohol, other modified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, styrene-maleic anhydride copolymer, styrene-butadiene copolymer, and Ethyl cellulose, cellulose derivatives such as acetyl cellulose, casein, arabia rubber, oxidized starch, etherified starch, dialdehyde starch, esterified starch, polyvinyl chloride, polyvinyl acetate, polyacrylamide, polyacrylic acid ester, polyvinyl butyral, polystyrose And their copolymers, polyamide resin, silicone resin, petroleum resin, terpene resin, ketone resin, kumaron resin and the like can be exemplified. These polymer substances are used by dissolving them in solvents such as water, alcohols, ketones, esters, and hydrocarbons, and are also used in a state of being emulsified or dispersed in a paste in water or other media to achieve the required quality. It can also be used together depending on the situation.

Further, in the present invention, a cross-linking agent can also be used in combination. Examples of the cross-linking agent include epichlorohydrin-based resins such as polyamine epichlorohydrin resin and polyamide epichlorohydrin resin, polyamide urea-based resins, polyalkylene polyamine resins, polyalkylene polyamide resins, polyamine polyurea-based resins, and modified polyamines. Polyamine / polyamide resin such as resin, modified polyamide resin, polyalkylene polyamine urea formalin resin, or polyalkylene polyamine polyamide polyurea resin, glioxal, methylol melamine, melamine formaldehyde resin, melamine urea resin, potassium persulfate, ammonium persulfate, excess Examples thereof include sodium sulfate, ferric chloride, magnesium chloride, borosand, boric acid, myoban, and ammonium chloride.

In the present invention, it is preferable to contain a carboxyl group-containing resin as a binder and an epichlorohydrin-based resin and a polyamine / polyamide-based resin as a cross-linking agent in the heat-sensitive recording layer because the water resistance is particularly good.
In the present invention, the reason why the water resistance is particularly good when the heat-sensitive recording layer contains a carboxyl group-containing resin as a binder and epichlorohydrin-based resin and a polyamine / polyamide-based resin as a cross-linking agent is as follows. Is guessed as.

A cross-linking reaction (first water resistance) occurs between the carboxyl group of the carboxyl group-containing resin and the amine portion or amide portion of the epichlorohydrin-based resin which is a cross-linking agent. Next, since the hydrophilic cross-linking site formed by the carboxyl group-containing resin and the epichlorohydrin-based resin and the hydrophilic site of the polyamine / polyamide-based resin attract each other, this cross-linking site is the hydrophobic group of the polyamine / polyamide-based resin. It is in a state of being wrapped with the surface facing outward, that is, a state in which the hydrophilic cross-linking site is protected from water by a hydrophobic group (second water resistance). Therefore, it is presumed that extremely high hydrophobicity is imparted to the reaction site between the carboxyl group-containing resin and the cross-linking agent, and the water resistance is particularly good.

The carboxyl group-containing resin used in the heat-sensitive recording layer of the present invention may be any one as long as it mainly has a carboxyl group, and is methacrylic acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylamino methacrylate. Examples thereof include acrylic resins containing monofunctional acrylic monomers having a carboxyl group such as ethyl, glycidyl methacrylate, and tetrahydrofrifuryl methacrylate, oxidized starch, carboxylmethylcellulose, and carboxy-modified polyvinyl alcohol in which a carboxyl group is introduced into polyvinyl alcohol. It is possible.
In particular, when the carboxyl group-containing resin is carboxy-modified polyvinyl alcohol, the plasticizer resistance of the image portion and the heat resistance of the blank portion are further improved, which is preferable. It is presumed that this is because, in addition to the above-mentioned cross-linking reaction, the cationic moiety of the polyamine / polyamide resin further cross-links with the carboxyl group of the carboxy-modified polyvinyl alcohol.

The carboxy-modified polyvinyl alcohol used in the heat-sensitive recording layer of the present invention is a reaction product of polyvinyl alcohol with a polyvalent carboxylic acid such as fumaric acid, phthalic acid anhydride, melitric acid anhydride, itaconic acid anhydride, or an ester of these reactants. It is obtained as a saponified product of vinyl acetate and a copolymer of maleic acid, fumaric acid, itaconic acid, crotonic acid, acrylic acid, methacrylic acid and other ethylenically unsaturated dicarboxylic acids. Specific examples thereof include the production method exemplified in Examples 1 or 4 of JP-A-53-91995. The degree of saponification of the carboxy-modified polyvinyl alcohol is preferably 72 to 100 mol%, the degree of polymerization is preferably 500 to 2400, and more preferably 1000 to 2000.

The epichlorohydrin-based resin used in the heat-sensitive recording layer of the present invention is a resin characterized by containing an epoxy group in the molecule, and is the above-mentioned polyamide epichlorohydrin resin and polyamine epichlorohydrin. Resin and the like can be mentioned.
As the amine present in the main chain of the epichlorohydrin-based resin, primary to quaternary amines can be used, and there is no particular limitation. Further, since the degree of cationization and the molecular weight have good water resistance, the degree of cationization is preferably 5 meq / g · Solid or less (measured value at pH 7), and the molecular weight is preferably 500,000 or more. These epichlorohydrin-based resins can be used alone or in combination of two or more.
Specific examples of the epichlorohydrin-based resin used in the heat-sensitive recording layer of the present invention include violet resin 650 (30), violet resin 675A, violet resin 6615 (all manufactured by Sumitomo Chemical Corporation), WS4002, and WS4020. , WS4024, WS4030, WS4046, WS4010, CP8970 (all manufactured by Seiko PMC) and the like.

The polyamine / polyamide resin used in the heat-sensitive recording layer of the present invention is a resin characterized by having no epoxy group in the molecule, and is the above-mentioned polyamide urea resin, polyalkylene polyamine resin, polyalkylene polyamide resin. , Polyamine polyurea resin, modified polyamine resin, modified polyamide resin, polyalkylene polyamine urea formalin resin, polyalkylene polyamine polyamide polyurea resin and the like.
Among these polyamine / polyamide resins, polyamine resins (polyalkylene polyamine resin, polyamine polyurea resin, modified polyamine resin, polyalkylene polyamine urea formalin resin, polyalkylene polyamine polyamide polyurea) are particularly good in water resistance. Trees, etc.) are preferably used. These polyamine / polyamide resins can be used alone or in combination of two or more.
Specific examples of the polyamine / polyamide resin used in the heat-sensitive recording layer of the present invention include violets resin 302 (manufactured by Sumitomo Chemical Co., Ltd .: polyamine polyurea resin) and violets resin 712 (manufactured by Sumitomo Chemical Co., Ltd .: polyamine polyurea resin). ), Sumire's Resin 703 (Sumitomo Chemical Co., Ltd .: Polyamine Polyurea Resin), Sumire's Resin 636 (Sumitomo Chemical Co., Ltd .: Polyamide Polyurea Resin), Sumitomo Chemical Co., Ltd .: Modified Polyamine Resin) , Sumire's Resin SPI-102A (Sumitomo Chemical Co., Ltd .: Modified Polyamine Resin), Sumitomo Chemical Co., Ltd .: Modified Polyamide Resin), Sumitomo Chemical Co., Ltd .: Modified Polyamide Resin), Sumitomo Chemical Co., Ltd. , Sumirase Resin SPI-198 (manufactured by Sumitomo Chemical Co., Ltd.), Printive A-700 (manufactured by Asahi Kasei Co., Ltd.), Printive A-600 (manufactured by Asahi Kasei Co., Ltd.), PA6500, PA6504, PA6634, PA6638, PA6640, PA6644, PA6646, Examples thereof include PA6654, PA6702, and PA6704 (all manufactured by Seikou PMC: polyalkylene polyamine polyamide polyurea resin).

Examples of the lubricant used in the present invention include fatty acid metal salts such as zinc stearate and calcium stearate, waxes, and silicone resins.

In the present invention, 4,4'-butylidene (6-t-butyl-3-methylphenol), 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. In addition, benzophenone-based and triazole-based ultraviolet absorbers, dispersants, antifoaming agents, antioxidants, fluorescent dyes and the like can be used.

The types and amounts of the leuco dye, the color developer, the sensitizer, and various other components used in the heat-sensitive recording layer of the present invention are determined according to the required performance and recording suitability, and are not particularly limited. Usually, 0.5 to 10 parts by weight of a developer, 0.1 to 10 parts by weight of a sensitizer, 0.5 to 20 parts by weight of a pigment, and 0.01 to 10 parts by weight of a stabilizer are used with respect to 1 part by weight of leuco dye. Use about 0.01 to 10 parts by weight of parts and other components. The binder is preferably about 5 to 25% by weight in the solid content of the heat-sensitive recording layer.

In the present invention, the leuco dye, the color developer, and the material to be added as needed are atomized by a crusher such as a ball mill, an attritor, a sand glider, or a suitable emulsifying device to a particle size of several microns or less, and the binder is used. And various additive materials are added according to the purpose to make a coating liquid. Water, alcohol, or the like can be used as the solvent used in this coating liquid, and the solid content thereof is about 20 to 40% by weight.

In the heat-sensitive recording body of the present invention, a protective layer may be further provided on the heat-sensitive recording layer. The protective layer usually contains a pigment and a resin as main components, and binders, pigments, cross-linking agents and the like exemplified as materials that can be used for the heat-sensitive recording layer can be used.
As the binder, a binder that can be used for the above-mentioned heat-sensitive recording layer can be appropriately used, but carboxy-modified polyvinyl alcohol and a non-core shell type acrylic resin are preferable. These binders may be used alone or in combination of two or more.
As the cross-linking agent, a cross-linking agent that can be used for the above-mentioned heat-sensitive recording layer can be appropriately used, but epichlorohydrin-based resins and polyamine / polyamide-based resins (included in the epichlorohydrin-based resin) are used. Excludes) is preferable.
It is more preferable that the protective layer contains an epichlorohydrin-based resin and a polyamine / polyamide-based resin together with carboxy-modified polyvinyl alcohol, whereby the color development performance is further improved.

This carboxy-modified polyvinyl alcohol is, for example, a reaction product of polyvinyl alcohol with a polyvalent carboxylic acid such as fumaric acid, phthalic acid anhydride, melitric acid anhydride, itaconic acid anhydride, an esterified product of these reactants, and vinyl acetate. It is obtained as a saponified product of a copolymer with an ethylenically unsaturated dicarboxylic acid such as maleic acid, fumaric acid, itaconic acid, crotonic acid, acrylic acid and methacrylic acid. As a specific manufacturing method, for example, the method exemplified in JP-A-53-91995 can be mentioned. The degree of saponification of the carboxy-modified polyvinyl alcohol is preferably 72 to 100 mol%, and the degree of polymerization is preferably 500 to 2400, more preferably 1000 to 2000.

The glass transition point (Tg) of this non-core shell type acrylic resin is preferably 95 ° C. or lower, and more preferably higher than 50 ° C. This Tg is measured by differential scanning calorimetry (DSC).
This non-core shell type acrylic resin contains (meth) acrylic acid and a monomer component copolymerizable with (meth) acrylic acid, and the (meth) acrylic acid is 1 in 100 parts by weight of the non-core shell type acrylic resin. It is preferably about 10 parts by weight. (Meta) acrylic acid is alkali-soluble and has the property of turning a non-core-shell acrylic resin into a water-soluble resin by adding a neutralizing agent. By changing the non-core shell type acrylic resin to a water-soluble resin, the bondability to the pigment is remarkably improved, especially when the pigment is contained in the protective layer, and the protective layer has excellent strength even when a large amount of pigment is contained. Can be formed. Examples of the components copolymerizable with (meth) acrylic acid include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, butyl (meth) acrylic acid, and isobutyl (meth) acrylic acid. By alkyl acrylate resins such as pentyl (meth) acrylate, hexyl (meth) acrylate, -2-ethylhexyl (meth) acrylate, octyl (meth) acrylate and epoxy resins, silicone resins, styrenes or derivatives thereof. Modified alkyl acrylate resins such as the modified alkyl acrylate resin, (meth) acrylonitrile, acrylic acid ester, hydroxyalkyl acrylate ester can be exemplified, and in particular, (meth) acrylonitrile and / or methyl methacrylate may be blended. Is preferable. It is preferable to add 15 to 70 parts of (meth) acrylonitrile out of 100 parts of a non-core shell type acrylic resin. Further, it is preferable to contain 20 to 80 parts of methyl methacrylate in 100 parts of the non-core shell type acrylic resin. When (meth) acrylonitrile and methyl methacrylate are contained, 15 to 18 parts of (meth) acrylonitrile are blended in 100 parts of a non-core shell acrylic resin, and 20 to 80 parts of methyl methacrylate are blended in 100 parts of a non-core shell acrylic resin. Is preferable.

This epichlorohydrin-based resin is a resin characterized by containing an epoxy group in the molecule, and examples thereof include polyamide epichlorohydrin resin and polyamine epichlorohydrin resin. These can be used alone or in combination. Further, as the amine present in the main chain of the epichlorohydrin-based resin, primary to quaternary amines can be used, and there is no particular limitation. Further, since the water resistance is good, the cationization degree and the molecular weight are preferably 5 meq / g · Solid or less (measured value at pH 7) and the molecular weight is 500,000 or more. Specific examples of the epichlorohydrin-based resin include violet resin 650 (30), violet resin 675A, violet resin 6615 (all manufactured by Sumitomo Chemical Corporation), WS4002, WS4020, WS4024, WS4030, WS4046, WS4010, CP8970 (all manufactured by Seiko PMC) and the like can be mentioned.

This polyamine / polyamide resin does not have an epoxy group in the molecule, for example, polyamide urea resin, polyalkylene polyamine resin, polyalkylene polyamide resin, polyamine polyurea resin, modified polyamine resin, modified polyamide resin, polyalkylene polyamine. Examples thereof include urea formalin resin, polyalkylene polyamine polyamide polyurea resin, and the like, and these can be used alone or in combination. Specific examples of the polyamine / polyamide resin include violet resin 302 (manufactured by Sumitomo Chemical Co., Ltd .: polyamine polyurea resin), violet resin 712 (manufactured by Sumitomo Chemical Co., Ltd .: polyamine polyurea resin), and violet resin 703 (Sumitomo Chemical Co., Ltd.). Company: Polyamine Polyurea Resin), Sumire's Resin 636 (Sumitomo Chemical Co., Ltd .: Polyamine Polyurea Resin), Sumire's Resin SPI-100 (Sumitomo Chemical Co., Ltd .: Modified Polyamine Resin), Sumire's Resin SPI-102A (Sumitomo) Chemical company: modified polyamine resin), violet resin SPI-106N (Sumitomo chemical company: modified polyamide resin), violet resin SPI-203 (50) (Sumitomo chemical company), violet resin SPI-198 (Sumitomo) Chemical Co., Ltd.), Printive A-700, Printive A-600 (above, manufactured by Asahi Kasei), PA6500, PA6504, PA6634, PA6638, PA6640, PA6644, PA6664, PA6654, PA6702, PA6704 (above, manufactured by Seikou PMC). : Polyalkylene polyamine polyamide polyurea resin), CP8994 (manufactured by Starlight PMC: polyethyleneimine resin) and the like. Although there is no particular limitation, polyamine-based resins (polyalkylene polyamine resin, polyamine polyamine resin, modified polyamine resin, polyalkylene polyamine urea formalin resin, polyalkylene polyamine polyamide polyurea resin) are used because the print density is good. Is preferable.

When the epichlorohydrin-based resin and the polyamine / polyamide-based resin are used together with the carboxy-modified polyvinyl alcohol for the protective layer, the content is preferably 1 to 100 parts by weight with respect to 100 parts by weight of the carboxy-modified polyvinyl alcohol. It is more preferably 5 to 50 parts by weight, further preferably 10 to 40 parts by weight.

As the pigment used for the protective layer, the pigment that can be used for the above-mentioned heat-sensitive recording layer can be appropriately used, but kaolin, calcined kaolin, aluminum hydroxide, and silica are preferable. These pigments may be used alone or in combination of two or more.
The content (solid content) of the binder in the protective layer is preferably 20% by weight or more, more preferably about 20 to 80% by weight, and when the protective layer contains a pigment, the content of the pigment and the binder is 100 parts by weight of the pigment. On the other hand, the binder preferably has a solid content of about 30 to 300 parts by weight.
The coating liquid of the protective layer may contain, if necessary, a cross-linking agent, a lubricant, a stabilizer, an ultraviolet absorber, a dispersant, an antifoaming agent, an antioxidant, a fluorescent dye, etc. that can be used for the above-mentioned heat-sensitive recording layer. Various auxiliary agents may be appropriately blended.

The heat-sensitive recording body of the present invention has a heat-sensitive recording layer on the support, but an undercoat layer may be provided between the support and the heat-sensitive recording layer.

This undercoat layer mainly consists of a binder and a pigment.
As the binder used for the undercoat layer, a commonly used emulsion of a water-soluble polymer or a hydrophobic polymer can be appropriately used. Specific examples include polyvinyl alcohol, polyvinyl acetal, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, and other cellulose derivatives, starch and its derivatives, sodium polyacrylic acid, polyvinylpyrrolidone, acrylic acid amide / acrylic acid ester copolymer, and acrylic acid. Water-soluble polymers such as amide / acrylic acid ester / methacrylic acid copolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, etc. Polyvinyl acetate, polyurethane, styrene / butadiene copolymer, polyacrylic acid, polyacrylic acid ester, vinyl chloride / vinyl acetate copolymer, polybutyl methacrylate, ethylene / vinyl acetate copolymer, styrene / butadiene / acrylic An emulsion of a hydrophobic polymer such as a polymer can be used. These binders may be used alone or in combination of two or more.

Examples of the pigment used for the undercoat layer include known pigments generally used in the past, and specific examples thereof include calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, magnesium hydroxide, calcined kaolin, clay, and talc. Inorganic pigments, hollow particles of plastic, etc. can be used. These pigments may be used alone or in combination of two or more. The plastic hollow particles are fine hollow particles having a thermoplastic resin as a shell and containing air or other gas inside, and are already in a foamed state. Examples of the thermoplastic resin include polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic acid ester, polyacrylonitrile, polybutadiene, and copolymers thereof. In particular, styrene resins such as polystyrene, acrylic resins such as polyacrylic acid esters and polyacrylic nitriles, copolymers thereof, and copolymer resins mainly composed of polyvinylidene chloride and polyacrylonitrile are preferable. Such organic hollow particles are available as SX8782 manufactured by JSR Corporation, MH5055 and MH8108A manufactured by Zeon Corporation, Rohm & Hearth Japan Co., Ltd. Low Pake HP-91, and Microsphere manufactured by Matsumoto Oil & Fat Co., Ltd.
The volume hollow ratio of the plastic hollow particles used in the present invention is preferably about 40 to 95%. By setting the volume hollow ratio to 40% or more, the heat insulating property can be improved and the color development performance can be further improved. On the other hand, when the content is 95% or less, the strength of the shell of the hollow particles is increased to effectively maintain the hollow state, and it becomes easy to obtain an undercoat layer having good surface strength. Here, the volume hollow ratio is a value obtained by (d3 / D3) × 100. In the formula, d indicates the inner diameter of the organic hollow particles, and D indicates the outer diameter of the organic hollow particles.

The pigment in the undercoat layer is usually 50 to 95 parts by weight, preferably 70 to 90 parts by weight, based on 100 parts by weight of the total solid content. The content of the plastic hollow particles in the undercoat layer is usually 20% by weight or more, preferably 25 to 80% by weight, and more preferably 30 to 70% by weight with respect to the pigment (solid content) in the undercoat layer. If necessary, various auxiliaries such as dispersants, plasticizers, pH regulators, defoamers, water retention agents, preservatives, coloring dyes, and UV protection agents may be added to the coating liquid of the undercoat layer. good.

In the present invention, the means for coating the coating layer other than the heat-sensitive recording layer and the heat-sensitive recording layer, that is, the protective layer, the undercoat layer, and the like is not particularly limited, and the coating layer can be applied according to a well-known conventional technique. For example, an off-machine coating machine or an on-machine coating machine equipped with various coaters such as an air knife coater, a rod blade coater, a bent blade coater, a bevel blade coater, a roll coater, and a curtain coater is appropriately selected and used.
The amount of coating of the coating layer other than the heat-sensitive recording layer and the heat-sensitive recording layer is determined according to the required performance and recording suitability, and is not particularly limited, but the general coating amount of the heat-sensitive recording layer is solid. The amount of the protective layer applied is preferably about 2 to 12 g / m ² per minute, and the amount of the protective layer applied is preferably 0.5 to 5.0 g / m ² in terms of solid content.
Further, various known techniques in the field of heat-sensitive recording materials can be added as necessary, such as performing a smoothing treatment such as super calendar hanging after coating each coating layer.

Hereinafter, the present invention will be illustrated in Examples, but the present invention is not intended to be limited. In each Example and Comparative Example, "parts" indicates "parts by weight" and "%" indicates "% by weight" unless otherwise specified.

Each dispersion and coating liquid were prepared as follows.
A coating liquid for an undercoat layer was prepared by stirring and dispersing a formulation consisting of the following formulations.
<Coating liquid for undercoat layer 1>
Baked kaolin (manufactured by BASF, trade name: Ansilex 90)
100.0 parts Styrene-butadiene copolymer latex (manufactured by Nippon Zeon Corporation,
Product name: ST5526, solid content 48%) 10.0 parts Water 50.0 parts

<Coating liquid for undercoat layer 2>
Calcined kaolin (Ancilex 90) 20.0 parts Plastic hollow particles (manufactured by Zeon Corporation, trade name: Nipol)
MH8108A, hollowness 50%, solid content 27%) 296.3 parts Styrene-butadiene copolymer latex (ST5526,
Solid content 48%) 10.0 parts <Coating liquid for undercoat layer 3>
Calcined kaolin (Ancilex 90) 40.0 parts Plastic hollow particles (Nipol MH8108A) 222.2 parts Styrene-butadiene copolymer latex (ST5526) 10.0 parts <Coating liquid 4 for undercoat layer>
Calcined kaolin (Ancilex 90) 70.0 parts Plastic hollow particles (Nipol MH8108A) 111.1 parts Styrene-butadiene copolymer latex (ST5526) 10.0 parts

The developer dispersion liquid (A1 to A6 liquid), leuco dye dispersion liquid (B liquid), and sensitizer dispersion liquid (C1 to C2 liquid) having the following formulations are separately prepared with a sand grinder to an average particle size of 0.5 μm. It was prepared by wet grinding until it became.

Color developer dispersion liquid (A1 liquid)
6.0 parts of urea compound (A1) represented by the following chemical formula (Chemical formula 3)

Completely saponified polyvinyl alcohol aqueous solution (manufactured by Kuraray, trade name:
PVA117, solid content 10%) 5.0 parts Water 1.5 parts

Color developer dispersion liquid (A2 liquid)
6.0 parts of urea compound (A2) represented by the following chemical formula (Chemical formula 4)

Completely saponified polyvinyl alcohol aqueous solution (PVA117) 5.0 parts Water 1.5 parts

Color developer dispersion liquid (A3 liquid)
4,4'-Bis (3- (phenoxycarbonylamino) methylphenyl ureido) diphenyl sulfone (manufactured by Fine Ace, trade name: UU)
6.0 parts Completely saponified polyvinyl alcohol aqueous solution (PVA117) 5.0 parts Water 1.5 parts
Color developer dispersion liquid (A4 liquid)
N, N'-di- [3- (p-toluenesulfonyloxy) phenyl] urea (hereinafter referred to as "urea compound (A4)") 6.0 parts Completely saponified polyvinyl alcohol aqueous solution (PVA117) 5.0 parts 1.5 parts of water

Color developer dispersion liquid (A5 liquid)
4,4'-Dihydroxydiphenyl sulfone (manufactured by NICCA CHEMICAL CO., LTD., Product name:
44BPS) 6.0 parts Completely saponified polyvinyl alcohol aqueous solution (PVA117) 5.0 parts Water 1.5 parts
Color developer dispersion liquid (A6 liquid)
Phenolic compound represented by the chemical formula (Chemical formula 9) (manufactured by Nippon Soda Co., Ltd.,
Product name: D90) 6.0 copies

Completely saponified polyvinyl alcohol aqueous solution (PVA117) 5.0 parts Water 1.5 parts

Leuco dye dispersion liquid (B liquid)
3-Dibutylamino-6-Methyl-7-anilinofluoran (manufactured by Yamamoto Chemicals, Inc., trade name: ODB-2) 6.0 parts Completely saponified polyvinyl alcohol aqueous solution (PVA117) 5.0 parts Water 1. 5 copies

Sensitizer dispersion liquid (C1 liquid)
Diphenyl sulfone (manufactured by Fine Ace, trade name: DPS) 6.0 parts Completely saponified polyvinyl alcohol aqueous solution (PVA117) 5.0 parts Water 1.5 parts
Sensitizer dispersion liquid (C2 liquid)
Stearic acid amide (manufactured by Nihon Kasei Co., Ltd., trade name: AP1) 6.0 parts Completely saponified polyvinyl alcohol aqueous solution (PVA117) 5.0 parts Water 1.5 parts

Then, each dispersion was mixed at the following ratio to prepare a coating liquid for a heat-sensitive recording layer.
<Coating liquid for heat-sensitive recording layer>
Color developer dispersion (A1 liquid) 5.0 parts Color developer dispersion (A3 liquid) 1.0 part Leuco dye dispersion (B liquid) 3.0 parts Sensitizer dispersion (C1 liquid) 6.0 Part sensitizer dispersion liquid (C2 liquid) 6.0 parts Completely saponified polyvinyl alcohol aqueous solution (PVA117) 25.0 parts

[Example 1]
After applying the coating liquid for the undercoat layer to one side of the support (high-quality paper with a basis weight of 47 g / m ² ) by the vent blade method so that the coating amount is 10.0 g / m ² in terms of solid content. After drying, an undercoat layer coated paper was obtained.
On the undercoat layer of this undercoat layer coating paper, the coating liquid for the thermal recording layer is applied by the rod blade method so that the coating amount is 6.0 g / m ² in terms of solid content, and then dried. A heat-sensitive recorder was prepared by processing with a super calendar so that the smoothness was 100 to 500 seconds.
[Example 2]
In the coating liquid for the heat-sensitive recording layer, a heat-sensitive recording body was produced in the same manner as in Example 1 except that the color-developing agent dispersion liquid (A2 liquid) was used instead of the color-developing agent dispersion liquid (A1 liquid).

[Example 3]
In the coating liquid for the heat-sensitive recording layer, the blending amount of the color developer dispersion liquid (A1 liquid) was changed from 5.0 parts to 4.0 parts, and the blending amount of the color developer dispersion liquid (A3 liquid) was 1. A heat-sensitive recorder was produced in the same manner as in Example 1 except that the number of parts was changed from 0 to 2.0.
[Example 4]
In the coating liquid for the heat-sensitive recording layer, the blending amount of the color developer dispersion liquid (A1 liquid) was changed from 5.0 parts to 3.0 parts, and the blending amount of the color developer dispersion liquid (A3 liquid) was 1. A heat-sensitive recorder was produced in the same manner as in Example 1 except that the number of parts was changed from 0 to 3.0.

[Example 5]
In the coating liquid for the heat-sensitive recording layer, the blending amount of the color developer dispersion liquid (A1 liquid) was changed from 5.0 parts to 3.0 parts, and the blending amount of the color developer dispersion liquid (A3 liquid) was 1. The amount of the sensitizer dispersion (C1 solution) was changed from 6.0 to 12.0 without adding the sensitizer dispersion (C2). A heat-sensitive recording body was produced in the same manner as in Example 1 except for the above.
[Example 6]
In the coating liquid for the heat-sensitive recording layer, the blending amount of the color developer dispersion liquid (A1 liquid) was changed from 5.0 parts to 3.0 parts, and the blending amount of the color developer dispersion liquid (A3 liquid) was 1. The amount of the sensitizer dispersion (C2 solution) was changed from 6.0 to 12.0 without adding the sensitizer dispersion (C1). A heat-sensitive recording body was produced in the same manner as in Example 1 except for the above.

[Example 7]
In the coating liquid for the heat-sensitive recording layer, the blending amount of the developer dispersion liquid (A1 liquid) was changed from 5.0 parts to 4.0 parts, and 1.0 part of the color developer dispersion liquid (A4 liquid) was blended. A heat-sensitive recording body was produced in the same manner as in Example 1.
[Example 8]
A heat-sensitive recording body was produced in the same manner as in Example 1 except that the undercoat layer coating liquid 2 was used instead of the undercoat layer coating liquid 1.
[Example 9]
A heat-sensitive recording body was produced in the same manner as in Example 1 except that the undercoat layer coating liquid 3 was used instead of the undercoat layer coating liquid 1.
[Example 10]
A heat-sensitive recording body was produced in the same manner as in Example 1 except that the undercoat layer coating liquid 4 was used instead of the undercoat layer coating liquid 1.

[Comparative Example 1]
In the coating liquid for the heat-sensitive recording layer, except that the color developer dispersion liquid (A3 liquid) was not blended and the blending amount of the color developer dispersion liquid (A1 liquid) was changed from 5.0 parts to 6.0 parts. , A heat-sensitive recorder was produced in the same manner as in Example 1.
[Comparative Example 2]
In the coating liquid for the heat-sensitive recording layer, except that the color developer dispersion liquid (A1 liquid) was not blended and the blending amount of the color developer dispersion liquid (A3 liquid) was changed from 1.0 part to 6.0 parts. , A heat-sensitive recorder was produced in the same manner as in Example 1.
[Comparative Example 3]
In the coating liquid for the heat-sensitive recording layer, the same as in Example 1 except that the color developer dispersion liquid (A1 liquid) was not blended and 5.0 parts of the color developer dispersion liquid (A5 liquid) was added and blended. A heat-sensitive recorder was prepared.
[Comparative Example 4]
Same as Example 1 except that the coating liquid for the heat-sensitive recording layer was not mixed with the color developer dispersion liquid (A3 liquid), but was mixed with 1.0 part of the color developer dispersion liquid (A6 liquid). A heat-sensitive recorder was prepared.
[Comparative Example 5]
In the coating liquid for the heat-sensitive recording layer, the blending amount of the color developer dispersion liquid (A1 liquid) was changed from 5.0 parts to 1.0 part, and the blending amount of the color developer dispersion liquid (A3 liquid) was 1. A heat-sensitive recorder was produced in the same manner as in Example 1 except that the number of parts was changed from 0 to 5.0.

The prepared heat-sensitive recorder was evaluated as follows.
<Color development performance (print density)>
For the manufactured heat-sensitive recorder, TH-PMD manufactured by Okura Electric Co., Ltd. (with a thermal recording paper printing tester and a thermal head manufactured by Kyocera) was used, and the printing speed was 50 mm / sec and the applied energy was 0.41 mJ / dot. The pattern was printed. The print density of the print unit was measured with a Macbeth densitometer (RD-914, using an amber filter), and the color development performance (print density) was evaluated.

<Printing runnability (head residue resistance)>
The manufactured heat-sensitive recorder is printed with a grid of 30 cm in length using a SATO label printer (Resprit R-8), and the residue (head residue) adhering to the thermal head after printing is visually evaluated according to the following criteria. did.
Yu: Almost no head residue was observed.
Possible: Although some head residue was observed, there was no omission or blurring of the formed image, and there was no problem in practical use.
Impossible: Many head scraps were attached, and the formed image was missing or blurred.

<Heat resistance>
The manufactured heat-sensitive recorder uses TH-PMD manufactured by Okura Electric Co., Ltd. (with a thermal recording paper printing tester and a thermal head manufactured by Kyocera), and has a checkered pattern with an applied energy of 0.41 mJ / dot and a printing speed of 50 mm / sec. Was printed. After the printed heat-sensitive recorder was left to stand in a 60 ° C. dry environment for 24 hours, the print density of the printed part was measured with a Macbeth densitometer (RD-914, using an amber filter), and the residual rate was calculated from the values before and after processing. Then, the heat resistance was evaluated.
Residual rate (%) = (print density of the printed part after processing / print density of the print part before processing) × 100
Excellent: Residual rate of 80% or more Possible: Residual rate of 50% or more, less than 80% Impossible: Residual rate of less than 50%

<Water resistance>
The manufactured heat-sensitive recorder uses TH-PMD manufactured by Okura Electric Co., Ltd. (with a thermal recording paper printing tester and a thermal head manufactured by Kyocera), and has a checkered pattern with an applied energy of 0.41 mJ / dot and a printing speed of 50 mm / sec. Was printed. The printed thermal recorder was immersed in tap water at 23 ° C. under 50% RH environmental conditions for 24 hours. The print density of the printed portion was measured with a Macbeth densitometer (RD-914, using an amber filter), and the residual ratio was calculated from the values before and after the treatment to evaluate the water resistance.
Residual rate (%) = (print density of the printed part after processing / print density of the print part before processing) × 100
Excellent: Residual rate of 80% or more Possible: Residual rate of 60% or more, less than 80% Impossible: Residual rate of less than 60%

<Heat-resistant ground color>
The manufactured heat-sensitive recorder uses TH-PMD manufactured by Okura Electric Co., Ltd. (with a thermal recording paper printing tester and a thermal head manufactured by Kyocera), and has a checkered pattern with an applied energy of 0.41 mJ / dot and a printing speed of 50 mm / sec. Was printed. After the printed heat-sensitive recorder was left at 80 ° C. or 90 ° C. for 24 hours in a dry environment, the density of the non-printed portion (blank paper portion) was measured with a Macbeth densitometer (RD-914, using an amber filter) to determine discoloration. evaluated.
Excellent: Skin concentration is less than 0.1 Possible: Skin concentration is less than 0.4 Impossible: Skin concentration is 0.4 or more

<Moisture and heat resistance>
The manufactured heat-sensitive recorder uses TH-PMD manufactured by Okura Electric Co., Ltd. (with a thermal recording paper printing tester and a thermal head manufactured by Kyocera), and has a checkered pattern with an applied energy of 0.41 mJ / dot and a printing speed of 50 mm / sec. Was printed. After the printed heat-sensitive recorder was left at 40 ° C. and 50% RH environment for 24 hours, the print density of the printed part was measured with a Macbeth densitometer (RD-914, using amber filter), and the residual rate was measured from the values before and after processing. Was calculated and the moisture and heat resistance was evaluated.
Residual rate (%) = (print density of the printed part after processing / print density of the print part before processing) × 100
Excellent: Residual rate of 90% or more Possible: Residual rate of 70% or more, less than 90% Impossible: Residual rate of less than 70%

<Plasticizer resistance>
The manufactured heat-sensitive recorder uses TH-PMD manufactured by Okura Electric Co., Ltd. (with a thermal recording paper printing tester and a thermal head manufactured by Kyocera), and has a checkered pattern with an applied energy of 0.41 mJ / dot and a printing speed of 50 mm / sec. Was printed.
The printed heat-sensitive recorder is attached to a paper tube with PVC wrap (Mitsui Chemicals High Wrap KMA) wrapped once, and then wrapped with PVC wrap three times, at 23 ° C, 50% RH environmental conditions. It was allowed to stand underneath for 24 hours.
The print density of the printed portion was measured with a Macbeth densitometer (RD-914, using an amber filter), and the residual ratio was calculated from the values before and after the treatment to evaluate the plasticizer resistance.
Residual rate (%) = (print density of the printed part after processing / print density of the print part before processing) × 100
Excellent: Residual rate of 70% or more Possible: Residual rate of 50% or more, less than 70% Impossible: Residual rate of less than 50%

The results are shown in the table below. The numerical values of the developer and the like in the table indicate the number of copies.

Claims (8)

1. A heat-sensitive recording material provided with a heat-sensitive recording layer containing a colorless or light-colored electron-donating leuco dye and an electron-accepting color developer on a support, wherein the heat-sensitive recording layer serves as an electron-accepting color developer. , The urea compound represented by the following general formula (Chemical formula 1) and the urea urethane-based compound represented by the following general formula (Chemical formula 2) are contained, and the content (solid) of the urea urethane-based compound in the heat-sensitive recording layer. Minutes) is 4 parts by weight or less with respect to 1 part by weight of the urea compound, which is a thermal recording body.
   

   

   (In the formula, R ¹ to R ⁵ may be the same or different, respectively, and may be the same or different, hydrogen atom, halogen atom, nitro group, amino group, alkyl group, alkoxy group, aryloxy group, alkylcarbonyloxy group, aryl. It represents a carbonyloxy group, an alkylcarbonylamino group, an arylcarbonylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, a monoalkylamino group, a dialkylamino group, or an arylamino group, and m represents an integer of 0 to 2. )
   

   
2. The heat-sensitive recorder according to claim 1, wherein the urea compound is represented by the following general formula (Chemical formula 3) or the following general formula (Chemical formula 4).
   

   

   
3. The heat-sensitive recording body according to claim 1 or 2, wherein the content (solid content) of the urea compound represented by the general formula (formulation 1) in the heat-sensitive recording layer is 5 to 50% by weight.
4. The heat-sensitive recording material according to any one of claims 1 to 3, wherein the heat-sensitive recording layer further contains a urea compound represented by the following general formula (Chemical Formula 8) as an electron-accepting color developer.
   

   

   (In the formula, R ⁶ represents an alkyl group or an alkoxy group, and n represents an integer of 0 to 3.)
5. The heat-sensitive recording material according to claim 4, wherein the urea compound represented by the general formula (formulation 8) in the heat-sensitive recording layer has the same content (solid content) of 1 to 50% by weight.
6. The content (solid content) of the urea urethane compound in the heat-sensitive recording layer is that of the urea compound (the urea compound represented by the general formula (Chemical formula 1) and the urea compound represented by the general formula (Chemical formula 8). The heat-sensitive recorder according to any one of claims 1 to 5, wherein the total amount is 0.01 to 3 parts by weight with respect to 1 part by weight.
7. The heat-sensitive recording layer contains a developing agent other than the urea compound and the urea urethane-based compound, and the sum of the urea compound and the urea urethane-based compound with respect to all the developing agents contained in the heat-sensitive recording layer. The heat-sensitive recorder according to any one of claims 1 to 6, wherein the content (solid content) is 90% by weight or more.
8. The heat-sensitive recording body according to any one of claims 1 to 7, further comprising a protective layer on the heat-sensitive recording layer in the previous term.