JP2023007483A - Ureylene-di(hydroxybenzoate) derivative and thermal recording material employing the same - Google Patents

Abstract

To provide a compound suitable as a developer for a thermal recording material.SOLUTION: The invention relates to a compound represented by the general formula (1) in the figure, where definition of each symbol is as described in the specification. The invention also relates to a thermal recording material and thermal recording paper that employ the compound represented by the general formula (1) as a developer.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ureylene-di(hydroxybenzoic acid ester) derivative and a heat-sensitive recording material using the same.

In general, heat-sensitive recording materials are produced by pulverizing and dispersing a basic dye, which is colorless or light-colored at room temperature, and an organic color developer into fine particles, and then mixing the two together. A thermal recording layer is formed by applying a coating liquid obtained by adding an agent to a support such as paper, plastic film, or processed paper. Color recording is obtained by applying heat. Such thermal recording materials have already been widely put into practical use.

The properties required for the thermal recording material include the whiteness of the unprinted area, the whiteness of the unprinted area under various environmental conditions, the color development density of the printed area, and the storage stability of the printed area. In particular, with respect to the storage stability of the printed portion, resistance to various tests, such as resistance to moist heat, water resistance, light resistance, oil resistance, and plasticizer resistance, is required.

Many color developers have been proposed so far as color developers for heat-sensitive recording materials. For example, 4,4'-isopropylidenediphenol, 4,4'-dihydroxydiphenylsulfone, 4-allyloxy-4'-hydroxy-diphenylsulfone (Patent Document 1), 4-hydroxy-4'-isopropyloxy-diphenylsulfone 4-(p-toluenesulfonylamino)salicylic acid (Patent Document 2), 4-octyloxycarbonylaminosalicylic acid and zinc salt (Patent Document 3), 4-(4-carboxybutyl) Ureidosalicylic acid (Patent Document 4), (phenylureido)benzoic acid (Patent Document 5) and other aminobenzoic acid and aminosalicylic acid-based color developers; N-3-[(p-toluenesulfonyl)oxy]phenyl-N'- (p-toluenesulfonyl)-urea (Patent Document 6), N-(2-(3-phenylureido)phenyl)benzenesulfonamide (Patent Document 7), N-3-[(p-toluenesulfonyl)oxy]phenyl -N'-phenyl-urea (Patent Document 8), N,N'-di{[3-(p-toluenesulfonyl)oxy]phenyl}urea (Patent Document 9), etc. is proposed.

JP-A-2002-052842 JP-A-07-246772 JP-A-09-263058 JP-A-2005-145935 JP-A-08-216526 Japanese Patent Publication No. 2002-532441 WO2014/080615 WO2017/111032 WO2019/044462

Written and edited by Shigeru Ohyo, "Organosulfur Chemistry", Kagaku Dojinsha, September 1982, p349

However, phenol-based color developers, benzoic acid, and aminosalicylic acid-based color developers do not have sufficient storage stability in printed and non-printed areas, and N-3-(p -Toluenesulfonyloxy)phenyl-N'-(p-toluenesulfonyl)-urea (Patent Document 6) has improved color development sensitivity and storage stability, but is not sufficient, and further improvement is desired. . In addition, N-3-(p-toluenesulfonyloxy)phenyl-N'-(p-toluenesulfonyl)-urea is a toluenesulfonylurea group derived from toluenesulfonylisocyanate, and toluenesulfonyl chloride. The aromatic sulfonic acid aryl ester group has two functional groups, and the aromatic sulfonic acid aryl ester group is stable against water (Non-Patent Document 1), while the toluenesulfonylurea group is originally Although it has been used as a protective group for amino groups and the like, it has the drawback of being easily hydrolyzed by water.

On the other hand, N-(2-(3-phenylureido)phenyl)benzenesulfonamide (Patent Document 7) and N-3-[(p-toluenesulfonyl)oxy]phenyl-N'-phenyl-urea (Patent Document 8) ), N,N'-di{[3-(p-toluenesulfonyl)oxy]phenyl}urea (Patent Document 9) still has a problem in the storage stability of the recording part, and the required performance as a heat-sensitive recording material is It is not fully satisfactory, and further improvement is required especially in the storage stability of the printed portion, especially in oil resistance and plasticizer resistance.

Furthermore, in recent years, 4,4'-isopropylidenediphenol, 4,4'-bisphenol sulfone and the like have been pointed out to have environmental hygiene problems such as endocrine disruptors and mutagenicity. A coloring agent is required.

The present invention has been made in view of the above circumstances, and N,N'-ureylene-bis(hydroxy benzoic acid ester) derivative and a heat-sensitive recording material using it as a color developer.

That is, the present invention includes the following aspects.

[1] General formula (1)

(In the formula, two R1 are each independently a linear, branched or alicyclic alkyl group having 1 to 12 carbon atoms; an aralkyl group having 7 to 12 carbon atoms; or 14 aryl groups,
two R2 are each independently a hydrogen atom; or -S(=O) ₂ R3 (R3 is unsubstituted, or an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 8 carbon atoms; a substituted aralkyl group having 7 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms.). )
A compound represented by (hereinafter sometimes referred to as "the compound of the present invention" or "the ureylene-di(hydroxybenzoic acid ester) derivative of the present invention").
[2] The compound of general formula (1) is represented by the following general formula (2)

(R3 has the same meaning as defined in [1] above.)
The compound according to [1] above, which is a compound represented by
[3] The compound of general formula (2) is represented by the following formula (3)

, equation (4)

, equation (5)

, and equation (6)

The compound according to the above [2], which is a compound represented by any one of
[4] A color developer containing the compound according to any one of [1] to [3] above.
[5] A thermal recording paint containing the compound according to any one of [1] to [3].
[6] A thermosensitive recording layer containing the compound according to any one of [1] to [3].
[7] A heat-sensitive recording material obtained by applying the heat-sensitive recording coating composition according to [5] to a support.
[8] A heat-sensitive recording material obtained by applying the heat-sensitive recording coating composition according to [5] above to a support.
[9] The thermosensitive recording material according to [7] above, wherein the support is paper, plastic film, or processed paper.
[10] The heat-sensitive recording material of the above [8], wherein the support is paper, plastic film or processed paper.
[11] A heat-sensitive recording material comprising a support and a heat-sensitive recording layer containing a colorless or light-colored basic dye at room temperature and a developer capable of developing color upon contact with the basic dye when heated. and a heat-sensitive recording material containing the compound according to any one of the above [1] to [3] as the color developer.
[12] Using the compound according to any one of the above [1] to [3] as a color developer in combination with a color developer selected from the group consisting of non-phenolic color developers and phenolic color developers. The thermal recording material according to [11] above, characterized by:

By using the ureylene-di(hydroxybenzoic acid ester) derivative of the present invention as a developer, the whiteness of the non-printed area is high, the color density is good, the storage stability of the printed area is high, and the oil resistance and resistance to It is possible to provide a heat-sensitive recording material with excellent plasticizing properties.

FIG. 4 shows an IR chart of 4,4′-ureylene-di(methyl 2-hydroxybenzoate) (Synthesis Example 1) according to the present invention. An IR chart of 4,4'-ureylene-di[2-(p-toluenesulfonyloxy)methyl benzoate] (Synthesis Example 2) according to the present invention is shown. 1 shows a ¹ H-NMR spectrum of 4,4′-ureylene-di[2-(p-toluenesulfonyloxy)methyl benzoate] (Synthesis Example 2) according to the present invention. FD mass spectrum of 4,4'-ureylene-di[2-(p-toluenesulfonyloxy)methyl benzoate] (Synthesis Example 2) according to the present invention is shown. An IR chart of 4,4'-ureylene-di[2-(1-naphthalenesulfonyloxy)methyl benzoate] (Synthesis Example 3) is shown in the present invention. An IR chart of 4,4'-ureylene-di[2-(O-toluenesulfonyloxy)methyl benzoate] (Synthesis Example 5) according to the present invention is shown. An IR chart of 4,4'-ureylene-di[2-(2-benzenesulfonyloxy)methyl benzoate] (Synthesis Example 6) according to the present invention is shown. An IR chart of 4,4'-ureylene-di[2-(2-naphthalenesulfonyloxy)methyl benzoate] (Synthesis Example 4) according to the present invention is shown.

(Ureylene-di(hydroxybenzoic acid ester) derivative of the present invention)
The ureylene-di(hydroxybenzoic acid ester) derivative of the present invention is represented by the general formulas (1) and (2).

In general formula (1), two R1 are each independently, for example, methyl group, ethyl group, propyl group, isopropyl group, isobutyl group, sec-butyl group, butyl group, hexyl group, cyclohexyl group, lauryl a linear or branched alkyl group having 1 to 12 carbon atoms (C1 to C12 alkyl group) which is a group;

benzyl group, p-methylbenzyl group, p-isopropylbenzyl group, p-tert-butylbenzyl group, p-methoxybenzyl group, m-methoxybenzyl group, m, p-dimethoxybenzyl group, phenethyl group, α-phenethyl group , an aralkyl group having 7 to 12 carbon atoms (C7 to C12) such as a phenylpropyl group;

phenyl group, tolyl group, p-ethylphenyl group, p-xylyl group, m-xylyl group, 1,2,3-trimethylphenyl group, 1,3,5-trimethylphenyl group (mesitylene group), 1,2, Examples thereof include aryl groups having 6 to 14 carbon atoms (C6 to C14) such as 4-trimethylphenyl group (pseudocumene group), 1-naphthyl group, 2-naphthyl group, biphenyl group and dimethylbiphenyl group.

Preferred R1 is a C1-C4 alkyl group.

Two R2 are each independently a hydrogen atom or a group represented by -S(=O) ₂ R3.

Preferred R2 is a group represented by -S(=O) ₂ R3.

R3 is, for example, a benzyl group, p-methylbenzyl group, p-isopropylbenzyl group, p-tert-butylbenzyl group, p-methoxybenzyl group, m-methoxybenzyl group, m,p-dimethoxybenzyl group, phenethyl group; , an α-phenethyl group, a C7-C12 aralkyl group substituted with an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, such as an α-phenethyl group or a phenylpropyl group;

phenyl group, tolyl group, p-ethylphenyl group, p-xylyl group, m-xylyl group, 1,2,3-trimethylphenyl group, 1,3,5-trimethylphenyl group (mesitylene group), 1,2, Unsubstituted such as 4-trimethylphenyl group (pseudocumene group), 1-naphthyl group, 2-naphthyl group, biphenyl group, dimethylbiphenyl group, or an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 8 carbon atoms C6-C14 aryl groups substituted with and the like.

Preferable R3 includes a phenyl group, a tolyl group, a mesitylene group, a 1-naphthyl group, a 2-naphthyl group and the like.

Compounds represented by the general formula (1) of the present invention include compounds represented by the following general formula (2).

(R3 is the same as defined in formula (1) above.)

Specific examples of the ureylene-di(hydroxybenzoic acid ester) derivative of the present invention are shown below, but are not limited thereto.

4,4'-Ureylene-di[2-(p-toluenesulfonyloxy)methyl benzoate], 4,4'-Ureylene-di[2-(benzenesulfonyloxy)methyl benzoate], 4,4'-Ureylene -di[2-(m-toluenesulfonyloxy)methyl benzoate], 4,4'-ureylene-di[2-(o-toluenesulfonyloxy)methyl benzoate], 4,4'-ureylene-di[2 -(xylenesulfonyloxy)methyl benzoate], 4,4'-ureylene-di[2-(mesitylenesulfonyloxy)methyl benzoate], 4,4'-ureylene-di[2-(1-naphthalenesulfonyloxy) methyl benzoate], 4,4′-ureylene-di[2-(2-naphthalenesulfonyloxy)methyl benzoate],

4,4′-Ureylene-di[2-(benzylsulfonyloxy)methyl benzoate], 4,4′-Ureylene-di[2-(p-toluenesulfonyloxy)n-propylbenzoate], 4,4′ -Ureylene-di[2-(1-naphthalenesulfonyloxy)n-propylbenzoate], 4,4'-Ureylene-di[2-(1-naphthalenesulfonyloxy)benzoate i-propyl], 4,4' -Ureylene-di[2-(2-naphthalenesulfonyloxy)n-butyl benzoate], 4,4'-Ureylene-di[2-(benzenesulfonyloxy)phenylbenzoate], 4,4'-Ureylene-di [2-(benzylsulfonyloxy)benzyl benzoate],

2,2'-ureylene-di[5-(p-toluenesulfonyloxy)methyl benzoate], 2,2'-ureylene-di[5-(1-naphthalenesulfonyloxy)methyl benzoate],

3,3′-Ureylene-di[6-(p-toluenesulfonyloxy)methyl benzoate], 3,3′-Ureylene-di[6-(benzenesulfonyloxy)methyl benzoate], 3,3′-Ureylene -di[6-(m-toluenesulfonyloxy)methyl benzoate], 3,3'-ureylene-di[6-(o-toluenesulfonyloxy)methyl benzoate], 3,3'-ureylene-di[6 -(xylenesulfonyloxy)methyl benzoate], 3,3′-ureylene-di[6-(mesitylenesulfonyloxy)methyl benzoate], 3,3′-ureylene-di[6-(1-naphthalenesulfonyloxy) methyl benzoate], 3,3′-ureylene-di[6-(2-naphthalenesulfonyloxy)methyl benzoate], 3,3′-ureylene-di[6-(benzylsulfonyloxy)methyl benzoate],

3,3'-ureylene-di[4-(p-toluenesulfonyloxy)methyl benzoate],

3,3′-Ureylene-di[2-(p-toluenesulfonyloxy)methyl benzoate], 3,3′-Ureylene-di[2-(benzenesulfonyloxy)methyl benzoate], 3,3′-Ureylene -di[2-(m-toluenesulfonyloxy)methyl benzoate], 3,3'-ureylene-di[2-(o-toluenesulfonyloxy)methyl benzoate], 3,3'-ureylene-di[2 -(xylenesulfonyloxy)methyl benzoate], 3,3′-ureylene-di[2-(mesitylenesulfonyloxy)methyl benzoate], 3,3′-ureylene-di[2-(1-naphthalenesulfonyloxy) methyl benzoate], 3,3′-ureylene-di[2-(2-naphthalenesulfonyloxy)methyl benzoate], 3,3′-ureylene-di[2-(benzylsulfonyloxy)methyl benzoate], 3 , 3′-ureylene-di[4-(p-toluenesulfonyloxy)methyl benzoate],

N-(3-hydroxy-4-methoxycarbonyl)phenyl-N′-(3-p-toluenesulfonyloxy-4-methoxycarbonyl)phenyl-urea, N-(3-hydroxy-4-methoxycarbonyl)phenyl-N '-(3-m-toluenesulfonyloxy-4-methoxycarbonyl)phenyl-urea, N-(3-hydroxy-4-methoxycarbonyl)phenyl-N'-(3-o-toluenesulfonyloxy-4-methoxycarbonyl ) phenyl-urea, N-(3-hydroxy-4-methoxycarbonyl)phenyl-N′-(3-benzenesulfonyloxy-4-methoxycarbonyl)phenyl-urea, N-(3-hydroxy-4-methoxycarbonyl) Phenyl-N'-(3-mesitylenesulfonyloxy-4-methoxycarbonyl)phenyl-urea, N-(3-hydroxy-4-methoxycarbonyl)phenyl-N'-[3-(1-naphthalenesulfonyloxy)-4 -methoxycarbonyl]phenyl-urea, N-(3-hydroxy-4-methoxycarbonyl)phenyl-N'-[3-(2-naphthalenesulfonyloxy)-4-methoxycarbonyl]phenyl-urea,

N-(4-hydroxy-5-methoxycarbonyl)phenyl-N′-(4-p-toluenesulfonyloxy-5-methoxycarbonyl)phenyl-urea, N-(4-hydroxy-5-methoxycarbonyl)phenyl-N '-(4-m-toluenesulfonyloxy-5-methoxycarbonyl)phenyl-urea, N-(4-hydroxy-5-methoxycarbonyl)phenyl-N'-(4-o-toluenesulfonyloxy-5-methoxycarbonyl ) phenyl-urea, N-(4-hydroxy-5-methoxycarbonyl)phenyl-N′-(4-benzenesulfonyloxy-5-methoxycarbonyl)phenyl-urea, N-(4-hydroxy-5-methoxycarbonyl) Phenyl-N'-(4-mesitylenesulfonyloxy-5-methoxycarbonyl)phenyl-urea, N-(4-hydroxy-5-methoxycarbonyl)phenyl-N'-[4-(1-naphthalenesulfonyloxy)-5 -methoxycarbonyl]phenyl-urea, N-(4-hydroxy-5-methoxycarbonyl)phenyl-N'-[4-(2-naphthalenesulfonyloxy)-5-methoxycarbonyl]phenyl-urea,

4,4'-Ureylene-di(2-hydroxybenzoate methyl), 4,4'-Ureylene-di(2-hydroxybenzoate ethyl), 4,4'-Ureylene-di(2-hydroxybenzoate n- propyl), 4,4′-ureylene-di(2-hydroxybenzoate i-propyl), 4,4′-ureylene-di(2-hydroxybenzoate butyl), 4,4′-ureylene-di(2- benzyl hydroxybenzoate), 4,4′-ureylene-di(phenethyl 2-hydroxybenzoate), 4,4′-ureylene-di(phenyl 2-hydroxybenzoate), 4,4′-ureylene-di(2 - 2-naphthyl hydroxybenzoate),

3,3'-ureylene-di(methyl 2-hydroxybenzoate), 3,3'-ureylene-di(ethyl 2-hydroxybenzoate),

5,5′-Ureylene-di(2-hydroxybenzoate methyl), 5,5′-Ureylene-di(2-hydroxybenzoate ethyl), 5,5′-Ureylene-di(2-hydroxybenzoate n- propyl), 5,5′-ureylene-di(2-hydroxybenzoate i-propyl), 5,5′-ureylene-di(2-hydroxybenzoate butyl), 5,5′-ureylene-di(2- benzyl hydroxybenzoate), 5,5′-ureylene-di(phenyl 2-hydroxybenzoate), 5,5′-ureylene-di(2-naphthyl 2-hydroxybenzoate),

4,4'-ureylene-di(3-hydroxybenzoate methyl), 4,4'-ureylene-di(3-hydroxybenzoate ethyl) and the like.

(Method for producing ureylene-di(hydroxybenzoic acid ester) derivative of the present invention)
The ureylene-di(hydroxybenzoic acid ester) derivative represented by the general formula (1) of the present invention can be synthesized by various methods. For example, the compound of general formula (8) is added to the amino-substituted hydroxybenzoic acid ester compound of general formula (7) with a urea bond-forming reagent (e.g., urea), as shown in reaction formula (1) below. Alternatively, it can be synthesized by reacting phosgene and phosgene derivatives, specifically triphosgene, carbonylbisimidazole, and N-substituted carbamic acid esters.

(Reaction formula 1)

general formula (7)

(R ₁ has the same definition as above.)

Furthermore, as shown in reaction formula (2), the compound of general formula (2) converts the compound of general formula (8), which is the product of reaction formula (1), into the halogenated compound represented by general formula (9). It can also be easily obtained by reacting a sulfonyl compound in the presence of a base.
(Reaction formula 2)

general formula (8)

( _R1 is the same as above.)

general formula (9)

(R3 has the same definition as above, and X represents a halogen atom such as F, Cl, Br, and I.)

Examples of amino-substituted hydroxybenzoic acid ester compounds represented by general formula (7) include methyl 4-aminosalicylate, ethyl 4-aminosalicylate, propyl 4-aminosalicylate, isopropyl 4-aminosalicylate, 4-amino butyl salicylate, benzyl 4-aminosalicylate, phenyl 4-aminosalicylate, p-cresyl 4-aminosalicylate, m-cresyl 4-aminosalicylate,

methyl 5-aminosalicylate, ethyl 5-aminosalicylate, propyl 5-aminosalicylate, isopropyl 5-aminosalicylate, butyl 5-aminosalicylate, benzyl 5-aminosalicylate, phenyl 5-aminosalicylate, p-cresyl 5-aminosalicylate, m-cresyl 5-aminosalicylate,

methyl 3-hydroxyanthranilate, ethyl 3-hydroxyanthranilate, propyl 3-hydroxyanthranilate, butyl 3-hydroxyanthranilate, benzyl 3-hydroxyanthranilate, phenyl 3-hydroxyanthranilate,

methyl 5-hydroxyanthranilate, ethyl 5-hydroxyanthranilate, propyl 5-hydroxyanthranilate, butyl 5-hydroxyanthranilate, benzyl 5-hydroxyanthranilate, phenyl 5-hydroxyanthranilate,

methyl 3-amino-4-hydroxybenzoate, ethyl 3-amino-4-hydroxybenzoate, propyl 3-amino-4-hydroxybenzoate,
methyl 4-amino-3-hydroxybenzoate, ethyl 4-amino-3-hydroxybenzoate,

Examples include methyl 3-amino-5-hydroxybenzoate and butyl 3-amino-5-hydroxybenzoate.

Sulfonyl halide compounds represented by formula (9) include, for example, benzylsulfonyl chloride, phenethylsulfonyl chloride, 4-methylbenzylsulfonyl chloride, benzenesulfonyl chloride, 4-methoxybenzenesulfonyl chloride, and 3,4-dimethoxybenzenesulfonyl chloride. chloride, p-toluenesulfonyl chloride, m-toluenesulfonyl chloride, o-toluenesulfonyl chloride, p-ethyl-benzenesulfonyl chloride, pt-butylbenzenesulfonyl chloride, mesitylenesulfonyl chloride, p-xylenesulfonyl chloride, 4-biphenyl sulfonyl chloride, 1-naphthalenesulfonyl chloride, 2-naphthalenesulfonyl chloride and the like.

(Thermal recording material of the present invention)
The heat-sensitive recording material of the present invention comprises a support provided with a heat-sensitive recording layer containing a colorless or light-colored basic dye at room temperature and a developer capable of developing color upon contact with the basic dye when heated. A heat-sensitive recording material characterized by containing the compound of the present invention as the color developer. Further, the compound of the present invention may be used in combination with an existing color developer, and when used in combination with an existing color developer, the compound of the present invention is used in an arbitrary ratio with the existing color developer. It can also be used as a preservative improving agent that has a color developing function to compensate for the preserving performance of existing color developers.

Existing color developers include, for example, N-3-[(p-toluenesulfonyloxy)phenyl]-N'-(p-toluenesulfonyl)-urea (PF-201), N-[2-(3-phenyl Ureido)phenyl]-benzenesulfonamide (NKK-1304), N-3-[(p-toluenesulfonyl)oxy]phenyl-N′-phenyl-urea (TGMD), N,N′-di{[3-( p-toluenesulfonyl)oxy]phenyl}urea, N-3-[(p-toluenesulfonyloxy)phenyl]-N'-(phenyl)-urea, di-[3-methyl-N-{5-(phenoxycarbonyl amino)phenyl}ureido]phenylsulfone (UU), N-(m-tolylaminocarbonyl)-methionine, N-(m-tolylaminocarbonyl)-phenylalanine, N-(phenylaminocarbonyl)-phenylalanine, 5-(N - known non-phenolic developers such as 3-methylphenyl-sulfonylamide)-(N',N''-bis-(3-methylphenyl)-isophthalic diamide (PF-425);

4,4'-isopropylidenediphenol (BPA), 4,4'-dihydroxydiphenylsulfone (BPS), 4-allyloxy-4'-hydroxydiphenylsulfone (BPS-MAE), bis(3-allyl-4-hydroxy Phenyl)sulfone (TGSA), 4-hydroxy-4'-isopropoxysulfone (D-8), and other compounds such as phenol-based color developers. By using them in combination with these color developers, it is possible to further improve storage stability, which is a problem of these color developers. Among the preferred existing color developers that can be used in combination are non-phenolic color developers.

In the heat-sensitive recording layer of the heat-sensitive recording material of the present invention, for example, the basic dye and the ureylene-di(hydroxybenzoic acid ester) derivatives represented by the formulas (1) to (6) are pulverized and dispersed into fine particles. Then, binders, sensitizers, fillers, lubricants, and other various additives are added to prepare a coating solution or coating solution (heat-sensitive recording paint), which is used for paper, plastic film, coated paper, etc. The heat-sensitive recording material of the present invention is formed by coating it on the support. As will be described later in the examples, the thermal recording paint to be coated on the support is often a coating liquid obtained by mixing dispersion liquids. It may also be gel or solid ink.

As the heat-sensitive recording material of the present invention, a heat-sensitive recording material obtained by partially coating a film, which is a packaging material, with a thermal ink containing the compound of the present invention can also be used. By applying heat to the partially coated portion with a thermal head or a laser device, high-precision printing can be directly printed on the film.

Examples of basic dyes which are colorless or light-colored at room temperature and which are used in the heat-sensitive recording layer of the heat-sensitive recording material of the present invention include triphenylmethane-based, fluoran-based, diphenylmethane-based, spiro-based, fluorene-based and thiazine-based compounds. It can be selected from known leuco dyes.

Leuco dyes include, for example, 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3,3-bis(p-dimethylaminophenyl)phthalide, 3-(4-diethylamino-2- ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)-4-azaphthalide, 3,3-bis(p-methylaminophenyl)-6-dimethylaminophthalide,

3-diethylamino-7-dibenzylaminobenzo[α]fluorane, 3-(1-ethyl-2-methylindol-3-yl)-3-(4-diethylamino-2-n-hexyloxyphenyl)- 4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(4-diethylamino)-2-methylphenyl-4-azaphthalide, 3-(4-diethylaminophenyl)-3 -(1-ethyl-2-methylindol-3-yl)phthalide, 3-(2-methyl-1-n-octylindol-3-yl)-3-(4-diethylamino-2-ethoxy phenyl)-4-azaphthalide,

3-(N-ethyl-N-isopentylamino)-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7- (o,p-dimethylanilino)fluorane, 3-(N-ethyl-Np-toluidino)-6-methyl 7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3-(N-cyclohexyl-N-methylamino)-6-methyl-7-anilinofluorane, 3-diethylamino-7-(o-chloroanilino ) fluorane, 3-diethylamino-7-(m-trifluoromethylanilino)fluorane, 3-di(n-pentyl)amino-6-methyl-7-anilinofluorane, 3-[N-(3-ethoxy Propyl)-N-ethylamino]6-methyl-7-anilinofluorane, 3-(N,N-hexyl-N-ethylamino)-7-(o-chloroanilino)fluorane, 3-(N-ethyl- N-2-tetrahydrofurfurylamino)-6-methyl-7-anilinofluorane,

2,2-bis{4-[6′-(N-cyclohexyl-N-methylamino)-3′-methylspiro[phthalid-3,9′-xanthene]-2′-ylamino]phenyl}propane, 3-dibutyl Amino-7-(o-chloroanilino)fluorane, 3,6-dimethoxyfluorane, 3-pyrrolidino-6-chlorofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-7-chloro Fluorane, 3-diethylamino-7,8-dibenzofluorane, 3-diethylamino-6,7-dimethylfluorane, 3-(N-methyl-p-toluidino)-7-methylfluorane, 3-(N- methyl-N-isoamylamino)-7,8-benzofluorane, 3,3′-bis(1-n-amyl-2-methylindol-3-yl)phthalide, 3-(N-methyl-N -isoamylamino)-7-phenoxyfluorane, 3,3′-bis(1-n-butyl-2-methylindol-3-yl)phthalide, 3,3′-bis(1-ethyl-2- methylindol-3-yl)phthalide, 3,3′-bis(p-dimethylaminophenyl)phthalide, 3-(N-ethyl-Np-tolylamino)-7-(N-phenyl-N-methyl amino)fluorane, 3-diethylamino-7-anilinofluorane, 3-diethylamino-7-benzylaminofluorane, 3-pyrrolidino-7-dibenzylaminofluorane, etc., and the present invention and may be used alone or in combination of two or more.

In the heat-sensitive recording layer of the heat-sensitive recording material of the present invention, a sensitizer can be used as necessary, and conventionally known sensitizers can be used as the sensitizer.

Examples of sensitizers include fatty acid amides such as stearic acid amide, bis-stearic acid amide and palmitic acid amide, p-toluenesulfonamide, stearic acid, behenic acid, fatty acid metal salts such as calcium, zinc and aluminum such as palmitic acid. , p-benzylbiphenyl, diphenylsulfone, benzyl benzyloxybenzoate, 2-benzyloxynaphthalene, 1,2-bis(p-tolyloxy)ethane, 1,2-bis(phenoxy)ethane, 1,2-bis(3 -methylphenoxy)ethane, 1,3-bis(phenoxy)propane, dibenzyl oxalate, p-methylbenzyl oxalate, m-terphenyl, 1-hydroxy-2-naphthoic acid and the like.

In particular, 1,2-bis(p-tolyloxy)ethane and 1,2-bis(phenoxy)ethane are preferred in terms of sensitivity.

The ureylene-di(hydroxybenzoic acid ester) derivative of the present invention has particularly good oil resistance and plasticizer resistance, and can be used as a storage stabilizer for conventionally known color developers.

Furthermore, conventionally known storage stabilizers can be used together in the heat-sensitive recording layer of the heat-sensitive recording material of the present invention.

Storage stabilizers such as 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 2,2'-ethylidenebis (4,6-di-tert-butylphenol), 4,4'-thiobis(2-methyl-6-tert-butylphenol), 4,4'-butylidenebis(6-tert-butyl m-cresol), 1 , 1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane, 4,4 '-bis [(4-methyl-3-phenoxycarbonylaminophenyl) ureido] diphenyl sulfone, tris (2,6-dimethyl-4-tert-butyl-3-hydroxybenzyl) isocyanurate, 4,4'-thiobis ( 3-methylphenol), 4,4′-dihydroxy-3,3′,5,5′-tetrabromodiphenylsulfone, 4,4′-dihydroxy-3,3′,5,5′-tetramethyldiphenylsulfone, 2 , 2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3,5- dimethylphenyl)propane and other hindered phenol compounds, 1,4-diglycidyloxybenzene, 4,4'-diglycidyloxydiphenylsulfone, 4-benzyloxy-4'-(2-methylglycyloxy)diphenylsulfone, Epoxy compounds such as glycidyl terephthalate, bisphenol A type epoxy resin type, cresol novolak type epoxy resin, phenol novolac type epoxy resin, N,N'-di-2-naphthyl-p-phenylenediamine, 2,2'-methylenebis (4,6-di-tert-butylphenyl) sodium salt or polyvalent metal salt of phosphate, bis(4-ethyleneiminecarbonylaminophenyl)methane, zinc 4-[2-(p-methoxyphenoxy)ethyloxy]salicylate, zinc 4-[3-(p-tolylsulfonyl)propyloxy]salicylate, zinc 5-[2-(p-methoxyphenoxyethoxy)cumyl]salicylate, zinc salt of 4-(n-octyloxycarbonylamino)salicylic acid, Furthermore, a diphenylsulfone crosslinked compound represented by the following general formula (10), etc. mentioned.

In particular 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane, 4,4′-Bis[(4-methyl-3-phenoxycarbonylaminophenyl)ureido]diphenylsulfone and diphenylsulfone crosslinked compounds represented by general formula (10) are suitable for further improving storage stability.

(In the formula, n represents an integer of 1 to 7.)

In addition, in the heat-sensitive recording layer of the heat-sensitive recording material of the present invention, an auxiliary agent can be used as necessary. Dispersants such as sodium and fatty acid metal salts; zinc stearate, calcium stearate, and higher fatty acid metal salts, higher fatty acid amides such as stearic acid amide, lubricants such as paraffin, polyethylene wax, polyethylene oxide wax, castor wax, and ester wax hydrazide compounds such as dihydrazide adipic acid; glyoxal, boric acid, dialdehyde starch, methylol urea, glyoxylate, waterproofing agents such as epoxy compounds; antifoaming agents; coloring dyes; fluorescent dyes; A pigment etc. are mentioned.

Examples of the binder used in the heat-sensitive recording layer of the present invention include starches such as oxidized starch, esterified starch and etherified starch; methylcellulose, carboxymethylcellulose, methoxycellulose, hydroxyethyl. Cellulose such as cellulose; casein, gelatin, completely (or partially) saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, Polyvinyl alcohols such as butyral-modified polyvinyl alcohol; styrene-maleic anhydride copolymer, styrene-butadiene copolymer resin and vinyl acetate resin; urethane resin; acrylamide resin; and copolymer resins thereof; amide resins; silicone resins; petroleum resins; terpene resins; ketone resins; These binders may be used singly or in combination of two or more. They may be dissolved in a solvent and used, or may be used in an emulsified or paste-dispersed state in water or another medium.

Pigments blended in the thermosensitive recording layer include, for example, amorphous silica, amorphous calcium silicate, heavy calcium carbonate, light calcium carbonate, kaolin, calcined kaolin, diatomaceous earth, talc, titanium dioxide, zinc oxide, water Inorganic or organic pigments such as aluminum oxide, magnesium hydroxide, barium sulfate, colloidal silica, polystyrene powder, nylon powder, urea-formalin resin filler, styrene-methacrylic acid copolymer, styrene-butadiene copolymer, hollow plastic pigment, etc. is mentioned.

In the present invention, the types and amounts of additives such as basic dyes, developers, sensitizers, binders, pigments, and other auxiliaries used in the heat-sensitive recording layer are determined according to the quality required for the heat-sensitive recording layer. It can be appropriately determined by those skilled in the art according to the performance.

In the heat-sensitive recording layer of the present invention, the content of the ureylene-di(hydroxybenzoic acid ester) derivative of the present invention as a developer is, from the viewpoint of color density, relative to 1 part by mass of the basic dye of the heat-sensitive recording layer. , preferably 0.3 to 5 parts by mass, and more preferably 0.4 to 3 parts by mass.

In addition, the content of the sensitizer in the thermosensitive recording layer is 0.2 to 4 parts by weight with respect to 1 part by weight of the basic dye (leuco dye), and the binder is 5 to 50% by weight of the total solid content of the thermosensitive recording layer. Appropriate.

Paper, recycled paper, synthetic paper, plastic film, nonwoven fabric, metal foil and the like can be used as the support in the present invention. Composite sheets in which these are combined can also be used. Here, the composite sheet includes, for example, a sheet made of a resin mixture, a laminate film, a sheet made of a plurality of resins such as a resin coating on a resin film, a resin printing on a resin film, a laminated composite substrate, and a conventional tack. Various base materials used as base materials such as paper can be used.

Another embodiment of the support in the present invention may be a card, paperboard, corrugated cardboard, or other thick material, or a rigid substrate such as a wafer. In still another aspect, the support may be composed of flexible thin-layer glass, film, paper, or the like, in order to realize a flexible (bendable) recording medium.

The material of the support in the present invention is not particularly limited, but examples include paper; polyester resin, polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PP), polyvinyl chloride (PVC), styrene-butadiene copolymer ( SBR), resins such as polyacrylic resins, polyurethane resins, and polystyrene resins; Moreover, not only the synthetic resins described above but also natural resins can be used for the plastic film as the support.

Furthermore, an overcoat layer made of a polymeric substance containing an organic pigment may be provided for the purpose of improving storage stability. Further, an undercoat layer containing organic pigments, inorganic pigments, hollow fine particles, foamed particles, etc. may be provided for the purpose of preventing dregs from adhering to the thermal head, improving printing image quality, and improving sensitivity.

Basic dyes, color developers, sensitizers, and optional storage stabilizers and the like used in the heat-sensitive recording layer in the present invention can be prepared, for example, by using water as a dispersion medium and using a ball mill, an attritor, or a sand mill. It is used after being finely dispersed by a stirring pulverizer such as the like so that the average particle size becomes 2 μm or less.

A heat-sensitive recording paint is prepared by mixing and stirring pigments, binders, auxiliaries, and the like, if necessary, into the dispersion thus finely dispersed.

The heat-sensitive recording paint thus obtained has a coating amount after drying of about 1.0 to 20 g/m ² , preferably about 1.5 to 12 g/m ² , more preferably 2.0 to 7.0 g. /m ² , particularly preferably about 3 to 7 g/m ² , is coated on the support and dried to form a heat-sensitive recording material.

A coating method for forming a heat-sensitive recording material is not particularly limited, and examples thereof include air knife coating, burr coating, pure blade coating, rod blade coating, curtain coating, die coating, slide velvet coating, and offset gravure. It can be applied by a suitable coating method such as coating or five-roll coating.

A heat-sensitive recording layer may be laminated on the support by directly coating the heat-sensitive recording coating prepared in this manner on the support, or an undercoat layer may be first formed on the support and then formed. A thermosensitive recording layer may be formed on the undercoat layer. By providing the undercoat layer, it is possible to improve the sensitivity and image quality, and improve the ability to absorb printing residue.
The composition of the undercoat layer may be appropriately selected depending on the purpose, but generally includes a binder, a pigment, and the like.

As the binder used in the undercoat layer, a resin such as that used in the thermosensitive recording layer can be used. Starches such as oxidized starch, esterified starch and etherified starch; cellulose resins such as methyl cellulose, carboxy cellulose, methoxy cellulose, methoxy cellulose and hydroxyethyl cellulose; Polyvinyl alcohols such as modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, butyral-modified polyvinyl alcohol; styrene-maleic anhydride copolymer latex, styrene-butadiene copolymer Polymer-based latexes, vinyl acetate resin-based latexes, urethane resin-based latexes, acrylic resin-based latexes, and the like can be used.

Inorganic pigments contained in the undercoat layer include metal oxides such as aluminum hydroxide, magnesium hydroxide, barium sulfate, aluminum silicate, and calcium carbonate; metal compounds such as metal hydroxides, sulfates, and carbonates; Examples include inorganic white pigments such as silica, calcined kaolin, and talc. Among these, calcined kaolin is particularly preferred because it is excellent in color development sensitivity and lees absorbability. Incidentally, the particle diameter of the inorganic pigment is preferably about 0.5 to 3.0 μm.

Examples of the organic pigment contained in the undercoat layer include spherical resin particles (so-called solid type resin particles), hollow particles, resin particles having through holes, and hollow resin particles obtained by cutting a part of the hollow resin particles with a modified surface. Examples include resins having openings such as those shown in FIG. A hollow resin is preferably used to increase the recording density.

In order to achieve both color development sensitivity and lees adsorption, it is common practice to use inorganic pigments and organic resins together. is preferred, and 70:30 to 50:50 is more preferred.

Furthermore, in order to improve the sensitivity, a foaming resin can also be used.

The undercoat layer generally uses water as a dispersion medium, and an undercoat layer coating obtained by mixing and stirring at least one selected from the group consisting of inorganic pigments and organic pigments and a binder is coated on a support in a coating amount of 1 after drying. It is formed by coating and drying so as to have a weight of up to 20 g/m ² , preferably about 5 to 15 g/m ² . The amount of the binder and pigment used is preferably about 5 to 40% by mass of the binder and about 10 to 95% by mass of the pigment based on the total solid content of the undercoat layer. Furthermore, various auxiliary agents such as lubricants such as zinc stearate, calcium stearate, and paraffin wax, fluorescent dyes, coloring dyes, surfactants, and cross-linking agents may be added to the coating material for the undercoat layer, if necessary. .

The undercoat layer may be one layer, or two or more layers depending on the case.

A protective layer containing a film-forming binder as a main component may be provided on the thermosensitive recording layer. The protective layer coating material is prepared, for example, by mixing and stirring a binder component, a pigment, and, if necessary, an auxiliary agent using water as a medium.

As binders, pigments and auxiliaries used in the protective layer, those used in the above heat-sensitive recording layer are used.

Also, a glossy layer may be provided on the protective layer. As the glossy layer, for example, a method of applying a coating liquid containing an electron beam or an ultraviolet curable compound as a main component, followed by curing by irradiation with an electron beam or ultraviolet rays, a method of using a core-shell type acrylic resin of ultrafine particles, etc. is mentioned. Furthermore, an antistatic layer may be provided on the back side of the support.

The paint for forming the undercoat layer, protective layer, gloss layer, etc., can be applied by an appropriate coating method such as pure blade coating, rod blade coating, curtain coating, offset gravure coating, etc., in the same manner as the thermosensitive recording layer. Each layer is formed by drying.

After forming each layer, various known processing techniques in the field of heat-sensitive recording material production, such as supercalendering, may be appropriately added.

EXAMPLES The present invention will be specifically described below with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited thereto. In the examples, "parts" and "%" represent "mass parts" and "mass%" unless otherwise specified.

(Synthesis Example 1) Synthesis of 4,4'-ureylene-di(methyl 2-hydroxybenzoate)

A four-necked flask equipped with a thermometer and a stirrer was charged with 100.4 g (600 mM) of methyl 4-aminosalicylate, 600 g of butyl acetate, and 49.6 g (306 mM) of carbonyldi(imidazole) and stirred. The reaction was stirred at 70° C. for 4 hours. The reaction liquid dissolves once as the reaction progresses, but crystals precipitate again and become a slurry state. Next, the reaction solution was cooled to 18° C., 200 g of water was added, stirred for 2 hours, and crystals were separated by filtration. The crystals separated by filtration were washed with dilute hydrochloric acid, water, multi-layered water and water in that order and dried to obtain 49.9 g of crystals of 4,4'-ureylene-di(methyl 2-hydroxybenzoate). An IR chart is shown in FIG.

(Synthesis Example 2) Synthesis of 4,4'-ureylene-di[2-(p-toluenesulfonyloxy)methyl benzoate]

7.2 g (20 mM) of 4,4'-ureylene-di(2-hydroxymethyl methyl benzoate) obtained in Synthesis Example 1, 80 g of ethyl acetate, and triethylamine4. 8 g (48 mM) was charged and warmed to 70°C. Next, an ethyl acetate solution in which 8.4 g (44 mM) of p-toluenesulfonyl chloride was dissolved was added dropwise, and the mixture was stirred for 6 hours. After completion of the reaction, the organic layer was washed successively with hydrochloric acid, aqueous sodium bicarbonate, and water. After distilling off the solvent, crystals were obtained by crystallizing with methanol and separating by filtration.

This crystal was confirmed to be 4,4′-ureylene-di[2-(p-toluenesulfonyloxy)methyl benzoate]. FIG. 2 shows an IR chart, FIG. 3 shows a ¹ H-NMR spectrum chart, and FIG. 4 shows a FD mass spectrum chart.

(Synthesis Example 3) Synthesis of 4,4'-ureylene-di[2-(1-naphthalenesulfonyloxy)methyl benzoate]

4,4'-Ureylene-di[2- (1-naphthalenesulfonyloxy)methyl benzoate] was synthesized. An IR chart is shown in FIG.

(Synthesis Example 4) Synthesis of 4,4'-ureylene-di[2-(2-naphthalenesulfonyloxy)methyl benzoate]

4,4'-Ureylene-di[2- (2-Naphthalenesulfonyloxy)methyl benzoate] was synthesized. An IR chart is shown in FIG.

(Synthesis Example 5) Synthesis of 4,4'-ureylene-di[2-(o-toluenesulfonyloxy)methyl benzoate]

4,4'-ureylene-di[2-(o-toluenesulfonyl oxy) methyl benzoate] was synthesized. An IR chart is shown in FIG.

(Synthesis Example 6) Synthesis of 4,4'-ureylene-di[2-(benzenesulfonyloxy)methyl benzoate]

4,4′-Ureylene-di[2-(benzene sulfonyloxy)methyl benzoate] were synthesized. An IR chart is shown in FIG.

[Preparation of undercoat paint]
100 parts of plastic hollow particles (trade name: Lopake SN-1055: hollowness: 55% by volume, solid content: 26.5%), 100 parts of calcined kaolin 50% dispersion, styrene-butadiene latex (trade name: L- 1571 (48% solids), 50 parts of a 10% aqueous solution of oxidized starch, and 20 parts of water were mixed to prepare an undercoat paint.

(Example 1)
[Creation of thermal recording paint]
A solution (preparation of dye dispersion)
3-(N,N-dibutylamino)-6-methyl-7-anilinofluorane
10 parts 10% polyvinyl alcohol aqueous solution 10 parts water 16.7 parts

B solution (preparation of developer dispersion)
4,4'-ureylene-di[2-(1-naphthalenesulfonyloxy)
Methyl benzoate] (Synthesis Example 3) 20 parts 10% polyvinyl alcohol aqueous solution 20 parts Water 33.3 parts

Solution C (preparation of sensitizer dispersion)
1,2-bis(m-tolyloxy)ethane 15 parts 10% polyvinyl alcohol aqueous solution 15 parts water 25 parts

The dispersion liquids of the liquids A, B, and C were pulverized with a sand grinder until the average particle size became 1 μm or less, and the dispersion liquids were mixed at the following ratio to prepare a coating liquid.
Liquid A (dye dispersion) 36.7 parts Liquid B (developer dispersion) 73.3 parts Liquid C (sensitizer dispersion) 55.0 parts

Aluminum hydroxide (trade name: Hygilite H-42) 27 parts, amorphous silica (trade name: Mizukasil P-527) 10 parts, 10% solution of oxidized starch 100 parts, zinc stearate dispersion: (trade name : Hydrin Z-8-36) 19.4 parts and water 50 parts were mixed to prepare a thermal recording paint.

[Preparation of thermal recording material]
As a support, a fine paper having a basis weight of 53 g/m ² is coated with an undercoat paint so that the mass per unit area after drying is 6 g/m ² and dried, and then a heat-sensitive recording paint is applied after drying. It was applied and dried so that the mass per area of the film was 3.8 g/m ² . This sheet was treated with a super calender so that the smoothness (JISP8155: 2010) was 900 to 1200 s to prepare a heat-sensitive recording material, and various tests (heat-sensitive recording test (color development test), moist heat resistance test, heat resistance test , water resistance test (according to two test methods), and plasticizer resistance test were carried out according to the methods described below, and the test results are shown in Table 1.

1. Thermal recording test (color development test)
The thermosensitive recording material thus prepared was applied with an applied energy of 0.38 mJ/dot using a thermosensitive recording paper printing tester (TH-PMD manufactured by Okura Electric Co., Ltd.). The print density of the recorded portion and the unprinted portion were measured with a Macbeth reflection densitometer RD-914. This was used as a pre-test sample (blank).

2. Humidity and heat resistance test In the heat-sensitive recording test, a heat-sensitive recording material recorded with an applied energy of 0.38 mJ/dot was left in an environment of a test temperature of 40 ° C. and 90% RH for 24 hours. Densities were measured with a Macbeth reflection densitometer.

3. Heat resistance test In the heat-sensitive recording test, a heat-sensitive recording material recorded with an applied energy of 0.38 mJ/dot was left in a constant temperature environment at a test temperature of 60°C for 24 hours. Measured with a reflection densitometer.

4. Water Resistance Test A heat-sensitive recording material recorded at an applied energy of 0.38 mJ/dot in a heat-sensitive recording test was immersed in water for 15 hours. .

5. Oil resistance test 1
In the heat-sensitive recording test, the heat-sensitive recording material recorded at an applied energy of 0.38 mJ/dot was immersed in salad oil for 10 minutes, after which the oil was wiped off the test piece, and the image density and the unprinted area were measured with a Macbeth reflection densitometer. .

6. Oil resistance test 2
In a thermal recording test, a thermal recording material recorded at an applied energy of 0.38 mJ/dot was immersed in salad oil for 3 hours, after which the oil was wiped off the test piece, and the image density and unprinted area were measured with a Macbeth reflection densitometer. bottom.

7. Plasticizer resistance test A thermal recording material recorded at an applied energy of 0.38 mJ/dot in a thermal recording test was covered with a wrap film (trade name: Hiwrap (registered trademark) KMA, manufactured by Mitsui Chemicals) on a polycarbonate pipe (48 mmφ). Wrap it three times, place a thermal recording material on it, wrap it three times with a wrap film, leave it for 24 hours in an environment of 20 ° C. and 65% RH, and then measure the image density and the unprinted part with a Macbeth reflection densitometer. measured in

(Example 2)
4,4'-Ureylene-di[2-(1-naphthalenesulfonyloxy) methyl benzoate] of solution B of Example 1 (Synthesis Example 3) was converted to 4,4'-ureylene-di[2-(p-toluene Sulfonyloxy)methyl benzoate] (Synthesis Example 2) was used in the same manner as in Example 1.

(Example 3)
4,4'-Ureylene-di[2-(1-naphthalenesulfonyloxy) methyl benzoate] of solution B of Example 1 (Synthesis Example 3) was converted to 4,4'-ureylene-di[2-(2-naphthalene Sulfonyloxy)methyl benzoate] (Synthesis Example 4) was used in the same manner as in Example 1. Table 1 shows the results of various tests on the heat-sensitive recording material according to this example.

(Example 4)
4,4'-Ureylene-di[2-(1-naphthalenesulfonyloxy)methyl benzoate] (Synthesis Example 3) of solution B of Example 1 was converted to 4,4'-ureylene-di[2-(benzenesulfonyloxy ) methyl benzoate] (Synthesis Example 6), but the same procedure as in Example 1 was performed. Table 1 shows the results of various tests on the heat-sensitive recording material according to this example.

(Example 5)
4,4'-Ureylene-di[2-(1-naphthalenesulfonyloxy) methyl benzoate] of solution B of Example 1 (Synthesis Example 3) was converted to 4,4'-ureylene-di[2-(o-toluene Sulfonyloxy)methyl benzoate] (Synthesis Example 5) was used in the same manner as in Example 1. Table 1 shows the results of various tests on the heat-sensitive recording material according to this example.

(Comparative example 1)
4,4'-Ureylene-di[2-(1-naphthalenesulfonyloxy)methyl benzoate] (Synthesis Example 3) of solution B of Example 1 was converted to N-3-[(p-toluenesulfonyl)oxy]phenyl- The same procedure as in Example 1 was performed, except that N'-(p-toluenesulfonyl)-urea was used. Table 1 shows the results of various tests on the heat-sensitive recording material according to this comparative example.

(Comparative example 2)
4,4'-Ureylene-di[2-(1-naphthalenesulfonyloxy)methyl benzoate] (Synthesis Example 3) of solution B of Example 1 was converted to N-(2-(3-phenylureido)phenyl)benzenesulfone The same operation as in Example 1 was performed except that amide was used. Table 1 shows the results of various tests on the heat-sensitive recording material according to this comparative example.

(Comparative Example 3)
4,4″-Ureylene-di[2-(1-naphthalenesulfonyloxy)methyl benzoate] (Synthesis Example 3) of solution B of Example 1 was converted to N-3-[(p-toluenesulfonyl)oxy]phenyl The same procedure as in Example 1 was performed, except that -N'-phenyl-urea was used. Table 1 shows the results of various tests on the heat-sensitive recording material according to this comparative example.

(Comparative Example 4)
4,4'-Ureylene-di[2-(1-naphthalenesulfonyloxy) methyl benzoate] of solution B of Example 1 (Synthesis Example 3) was converted to N,N'-di-[3-(p-toluenesulfonyl The same procedure as in Example 1 was performed, except that oxy)phenyl]urea was used. Table 1 shows the results of various tests on the heat-sensitive recording material according to this comparative example.

(Comparative Example 5)
The same procedure as in Example 1, except that 4,4'-ureylene-di[2-(1-naphthalenesulfonyloxy)methyl benzoate] (Synthesis Example 3) in Solution B of Example 1 was replaced with bisphenol A. performed. Table 1 shows the results of various tests on the heat-sensitive recording material according to this comparative example.

(Comparative Example 6)
The same procedure as in Example 1, except that 4,4'-ureylene-di[2-(1-naphthalenesulfonyloxy)methyl benzoate] (Synthesis Example 3) in Solution B of Example 1 was replaced with bisphenol S. performed. Table 1 shows the results of various tests on the heat-sensitive recording material according to this comparative example.

The test results of Examples 1-5 and Comparative Examples 1-6 were as shown in Table 1.

As is clear from Examples and Table 1, the heat-sensitive recording material produced from the ureylene-di(hydroxybenzoic acid ester) derivative of the present invention has a high degree of whiteness in the non-printing area and exhibits good color density. It was also good in all the storage tests of wet heat resistance, heat resistance, water resistance, oil resistance, and plasticizer resistance of the printed area, and was particularly excellent in oil resistance and plasticizer resistance.

In the heat-sensitive recording material produced from the ureylene-di(hydroxybenzoic acid ester) derivative of the present invention, the developer used is the ureylene-di(hydroxybenzoic acid ester) derivative represented by the general formula (1). Therefore, the whiteness of the non-printed area is high, the color density is good, and good storability is obtained in all storability tests. Promising.

Claims (10)

General formula (1)

(In the formula, two R1 are each independently a linear, branched or alicyclic alkyl group having 1 to 12 carbon atoms; an aralkyl group having 7 to 12 carbon atoms; or 14 aryl groups,
two R2 are each independently a hydrogen atom; or -S(=O) ₂ R3 (R3 is unsubstituted, or an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 8 carbon atoms; a substituted aralkyl group having 7 to 12 carbon atoms or an aryl group having 6 to 14 carbon atoms.). )
A compound represented by The compound of general formula (1) is represented by the following general formula (2)

(R3 has the same meaning as defined in claim 1.)
2. The compound according to claim 1, which is a compound represented by: The compound of general formula (2) is represented by the following formula (3)

, equation (4)

, equation (5)

, and equation (6)

3. The compound according to claim 2, which is a compound represented by any of A color developer containing the compound according to any one of claims 1 to 3. A heat-sensitive recording paint containing the compound according to any one of claims 1 to 3. A heat-sensitive recording layer containing the compound according to any one of claims 1 to 3. A heat-sensitive recording material obtained by applying the heat-sensitive recording paint according to claim 5 to a support. 8. The thermal recording material according to claim 7, wherein the support is paper, plastic film or processed paper. A heat-sensitive recording material comprising a support provided with a heat-sensitive recording layer containing a colorless or light-colored basic dye at room temperature and a color developer capable of developing color upon contact with the basic dye when heated, the material comprising: A heat-sensitive recording material containing the compound according to any one of claims 1 to 3 as a color developer. The compound according to any one of claims 1 to 3 and a color developer selected from the group consisting of non-phenolic color developers and phenolic color developers are used in combination as color developers. 10. The heat-sensitive recording material according to claim 9.

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