JP2002211141A - Thermal recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal recording medium which shows high stability to a plasticizer, fats and oils and the like and also a significantly enhanced recording sensitivity. SOLUTION: This thermal recording medium is characterized in that its thermal color developing layer contains at least one kind of a diphenylsulfone crosslinking compound represented by the described formula (1) as an organic developer, a diphenylsulfone derivative represented by the described formula (2) and a di(p-methylbenzyl) or a 1,2-bis(phenoxymethyl) benzene oxalate. [In the formulae (1) and (2), X and Y are 1-12C saturated or unsaturated or ether- linkage hydrocarbon groups which may be different from each other or may have a straight chain or a branched chain or (R is a methylene group or an ethylene group; and T is a hydrogen atom and a 1-4C alkyl group)].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive recording medium utilizing a color development reaction between a basic colorless dye and an organic color developer.

[0002]

2. Description of the Related Art In general, a heat-sensitive recording material having a heat-sensitive coloring layer mainly composed of a colorless or pale-colored dye precursor and a color developing agent which reacts with the dye precursor when heated to form a color is disclosed in JP-B-45-140.
No. 39, which is widely used. In order to perform recording on this thermosensitive recording medium, a thermal printer or the like having a built-in thermal head is used.However, such a thermosensitive recording method has less noise at the time of recording as compared with other recording methods that have been practically used conventionally. With no development and fixing, maintenance-free, relatively inexpensive and compact equipment, and very clear color development, the facsimile and computer fields Widely used for various measuring instruments and labels. With the diversification and high performance of these recording apparatuses, the required quality of the thermosensitive recording medium has become higher. As for the color sensitivity, as the size of the apparatus is reduced and the recording speed is increased, it is required that a clear color image with high density can be obtained even with a small amount of thermal energy. In order to satisfy these requirements, for example, JP-A-56-169087 discloses a method of increasing the color-forming sensitivity by adding a heat-soluble substance to a heat-sensitive layer, and JP-A-56-144193 discloses a method of improving the color developing ability. Although a method of increasing the color development sensitivity by using a high novel developer is described, the heat-resistant ground color is deteriorated, and dusting over time, and printing after long-term storage of the uncolored portion is described. Since it has drawbacks such as lowering of the color density (reprintability), it cannot be said that the quality is sufficient. In general, a method in which an appropriate sensitizer is further used in combination with a dye and a developer is known. For example, when the developer is a phenolic compound represented by bisphenol A, p-benzylbiphenyl (special) is used. Japanese Patent Application Laid-Open No. 60-82382), benzyl p-benzyloxybenzoate (JP-A-57-201691), benzylnaphthyl ether (JP-A-58-87094) and the like are used as suitable sensitizers. When a sensitizer is used, the sensitizer is first melted when heated, and the dye and the developer dissolve into each other at the molecular level to induce a color-forming reaction. It is important to consider dyes and color developers. In particular, when the recording sensitivity is improved with a sensitizer or the like, the storage stability of the recorded image often cannot be maintained. Specifically, defects such as remarkable decrease in image density and decoloration still occur when sebum components adhere or come into contact with a plasticizer (DOP, DOA, etc.) contained in a wrap film such as a PVC film. Was. In recent years, with increasing use in fields such as labels where reliability is required for recorded images, high storage stability against plasticizers, fats and oils contained in packaging materials and the like has been achieved. There is a need for the recording materials shown.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermosensitive recording medium which has high stability against plasticizers and fats and oils and has greatly improved recording sensitivity.

[0004]

SUMMARY OF THE INVENTION As a result of the present inventors' earnest studies, the present inventors have found that a thermosensitive recording layer provided with a thermosensitive coloring layer containing a colorless or pale-colored basic colorless dye and a developer as main components. In the body, the thermosensitive coloring layer contains at least one diphenylsulfone cross-linkable compound represented by the following general formula (1) as an organic developer, and further contains a diphenylsulfone derivative represented by the following general formula (2) And di (p-methylbenzyl) oxalate or 1,
Achieved by containing 2-bis (phenoxymethyl) benzene.

[0005]

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[Wherein, X and Y may be different from each other, may be linear or branched, and may have 1 to 12 carbon atoms;
Represents a hydrocarbon group which may have an unsaturated or ether bond, or

[0007]

Embedded image Or

[0008]

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(R represents a methylene group or an ethylene group, T represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms)
Represents R _{1 to} R ₆ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group. Also, m,
n, p, q, r, and t represent an integer from 0 to 4, and when 2 or more, R _{1 to} R ₆ may be different from each other. a represents an integer of 0 to 10. ]

[0010]

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(R _{7 to} R ₁₂ are a hydrogen atom, an alkyl group,
Represents a halogen atom, a nitro group, an alkoxy group, a cyano group, or an allyloxy group. )

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to obtain a thermosensitive recording medium of the present invention,
For example, a dye, a compound represented by formula (1) or (2), and a compound represented by di (p-methylbenzyl) oxalate or 1,2-bis (phenoxymethyl) benzene are dispersed together with a binder. The heat-sensitive recording medium of the present invention is prepared by mixing the dispersion liquid, adding a filler and other necessary additives to prepare a thermosensitive coloring layer coating solution, and coating and drying the base material to form a thermosensitive coloring layer. Can be manufactured. The diphenylsulfone bridged compound represented by the general formula (1) is described in JP-A-10-29969. Specific examples of the groups represented by X and Y in the diphenylsulfone bridged compound of the general formula (1) include the following. Methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, methylmethylene group, dimethylmethylene Group, methylethylene group, methyleneethylene group, ethylethylene group, 1,2-dimethylethylene group, 1-methyltrimethylene group, 1-methyltetramethylene group, 1,3-dimethyltrimethylene group, 1-ethyl-4 -Methyl-tetramethylene group, vinylene group, propenylene group, 2-butenylene group, ethynylene group,
-Butynylene group, 1-vinylethylene group, ethyleneoxyethylene group, tetramethyleneoxytetramethylene group, ethyleneoxyethyleneoxyethylene group, ethyleneoxymethyleneoxyethylene group, 1,3-dioxane-5,5-bismethylene group, 1 , 2-xylyl group,
1,3-xylyl group, 1,4-xylyl group, 2-hydroxytrimethylene group, 2-hydroxy-2-methyltrimethylene group, 2-hydroxy-2-ethyltrimethylene group, 2-hydroxy-2-propyl Trimethylene group, 2
-Hydroxy-2-isopropyltrimethylene group, 2-
And a hydroxy-2-butyltrimethylene group.

The alkyl group or alkenyl group of R _{1 to} R ₆ is a C1 to C6 alkyl group or a C1 to C6 alkenyl group, and specific examples include a methyl group, an ethyl group and an n-propyl group. Group, isopropyl group, n-butyl group,
sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, n-hexyl group, isohexyl group, 1-methylpentyl group, 2-methylpentyl group, vinyl group Allyl group, isopropenyl group, 1-propenyl group, 2-butenyl group, 3-butenyl group, 1,3-butanedienyl group, 2
-Methyl-2-propenyl group and the like. Further, the halogen atom represents chlorine, bromine, fluorine or iodine. In the present invention, the diphenylsulfone cross-linked compound represented by the general formula (1) can be used by mixing several kinds having different numbers of substituents and / or a, and the content ratio thereof is arbitrary. There is no particular limitation on the method of mixing, such as a method of mixing with a powder, a method of mixing in a state of a dispersion liquid dispersed in water or the like, and a method of simultaneously producing and containing a plurality of types of diphenylsulfone crosslinked compounds depending on production conditions. Specific examples of the compound represented by the general formula (1) are given below. (1-1) 4,4'-bis [4- [4- (4-hydroxyphenylsulfonyl) phenoxy] -2-trans-
Butenyloxy] diphenylsulfone (1-2) 4,4'-bis [4- (4-hydroxyphenylsulfonyl) phenoxy-4-butyloxy] diphenylsulfone (1-3) 4,4'-bis [4- (4- (Hydroxyphenylsulfonyl) phenoxy-3-propyloxy] diphenylsulfone (1-4) 4,4'-bis [4- (4-hydroxyphenylsulfonyl) phenoxy-2-ethyloxy] diphenylsulfone (1-5) 4- [ 4- (4-hydroxyphenylsulfonyl) phenoxy-4-butyloxy] -4 '-[4-
(4-hydroxyphenylsulfonyl) phenoxy-
3-propyloxy] diphenyl sulfone

(1-6) 4- [4- (4-hydroxyphenylsulfonyl) phenoxy-4-butyloxy]-
4 '-[4- (4-hydroxyphenylsulfonyl)
Phenoxy-2-ethyloxy] diphenylsulfone (1-7) 4- [4- (4-hydroxyphenylsulfonyl) phenoxy-3-propyloxy] -4 '-[4
-(4-hydroxyphenylsulfonyl) phenoxy-2-ethyloxy] diphenylsulfone (1-8) 4,4'-bis [4- (4-hydroxyphenylsulfonyl) phenoxy-5-pentyloxy] diphenylsulfone (1-9 ) 4,4'-Bis [4- (4-hydroxyphenylsulfonyl) phenoxy-6-hexyloxy] diphenylsulfone (1-10) 4- [4- [4- (4-hydroxyphenylsulfonyl) phenoxy] -2 -Trans-butenyloxy] -4 '-[4- (4-hydroxyphenylsulfonyl) phenoxy-4-butyloxy] diphenylsulfone (1-11) 4- [4- (4-hydroxyphenylsulfonyl) phenoxy-2-trans- Butenyloxy)
-4 '-[4- (4-hydroxyphenylsulfonyl)
Phenoxy-3-propyloxy] diphenylsulfone (1-12) 4- [4- [4- (4-hydroxyphenylsulfonyl) phenoxy] -2-trans-butenyloxy] -4 '-[4- (4-hydroxyphenyl Sulfonyl) phenoxy-2-ethyloxy] diphenylsulfone (1-13) 1,4-bis [4- [4- [4- (4-hydroxyphenylsulfonyl) phenoxy-2-trans-butenyloxy] phenylsulfonyl] phenoxy]- Cis-2-butene (1-14) 1,4-bis [4- [4- [4- (4-hydroxyphenylsulfonyl) phenoxy-2-trans-butenyloxy] phenylsulfonyl] phenoxy] -trans-2-butene (1-15) 4,4'-bis [4- [4- (2-hydroxyphenyls) Ruphonyl) phenoxy] butyloxy]
Diphenyl sulfone (1-16) 4,4'-bis [4- [2- (4-hydroxyphenylsulfonyl) phenoxy] butyloxy]
Diphenyl sulfone

(1-17) 4,4'-bis [4- (4-
(Hydroxyphenylsulfonyl) phenoxy-2-ethyleneoxyethoxy] diphenylsulfone (1-18) 4,4'-bis [4- (4-hydroxyphenylsulfonyl) phenyl-1,4-phenylenebismethyleneoxy] diphenylsulfone (1 -19) 4,4'-bis [4- (4-hydroxyphenylsulfonyl) phenyl-1,3-phenylenebismethyleneoxy] diphenylsulfone (1-20) 4,4'-bis [4- (4-hydroxy Phenylsulfonyl) phenyl-1,2-phenylenebismethyleneoxy] diphenylsulfone (1-21) 2,2′-bis [4- [4- [4- (4-
(Hydroxyphenylsulfonyl) phenoxy-2-ethyleneoxyethoxy] phenylsulfonyl] phenoxy] diethyl ether (1-22) α, α'-bis [4- [4- [4- (4-
(Hydroxyphenylsulfonyl) phenyl-1,4-phenylenebismethyleneoxy] phenylsulfonyl] phenoxy] -p-xylene (1-23) α, α'-bis [4- [4- [4- (4-
(Hydroxyphenylsulfonyl) phenyl-1,3-phenylenebismethyleneoxy] phenylsulfonyl] phenoxy] -m-xylene (1-24) α, α'-bis [4- [4- [4- (4-
(Hydroxyphenylsulfonyl) phenyl-1,2-phenylenebismethyleneoxy] phenylsulfonyl] phenoxy] -o-xylene (1-25) 2,4′-bis [2- (4-hydroxyphenylsulfonyl) phenoxy-2-ethylene Oxyethoxy] diphenylsulfone (1-26) 2,4'-bis [4- (2-hydroxyphenylsulfonyl) phenoxy-2-ethyleneoxyethoxy] diphenylsulfone (1-27) 4,4'-bis [3 5-dimethyl-4-
(3,5-dimethyl-4-hydroxyphenylsulfonyl) phenoxy-2-ethyleneoxyethoxy] diphenylsulfone (1-28) 4,4'-bis [3-allyl-4- (3-
Allyl-4-hydroxyphenylsulfonyl) phenoxy-2-ethyleneoxyethoxy] diphenylsulfone (1-29) 4,4'-bis [3,5-dimethyl-4-
(3,5-dimethyl-4-hydroxyphenylsulfonyl) phenyl-1,4-phenylenebismethyleneoxy] diphenylsulfone (1-30) 4,4'-bis [3,5-dimethyl-4-
(3,5-dimethyl-4-hydroxyphenylsulfonyl) phenyl-1,3-phenylenebismethyleneoxy] diphenylsulfone (1-31) 4,4'-bis [3,5-dimethyl-4-
(3,5-dimethyl-4-hydroxyphenylsulfonyl) phenyl-1,2-phenylenebismethyleneoxy] diphenylsulfone (1-32) 4,4'-bis [3-allyl-4- (3-
Allyl-4-hydroxyphenylsulfonyl) 1,4-
Phenylenebismethyleneoxy] diphenylsulfone (1-33) 4,4'-bis [3-allyl-4- (3-
Allyl-4-hydroxyphenylsulfonyl) 1,3-
Phenylenebismethyleneoxy] diphenylsulfone (1-34) 4,4'-bis [3-allyl-4- (3-
Allyl-4-hydroxyphenylsulfonyl) 1,2-
Phenylenebismethyleneoxy] diphenylsulfone (1-35) 4,4'-bis [4- (4-hydroxyphenylsulfonyl) phenoxy-2-hydroxypropyloxy] diphenylsulfone (1-36) 1,3-bis [4 -[4- [4- (4-hydroxyphenylsulfonyl) phenoxy-2-hydroxypropyloxy] phenylsulfonyl] phenoxy] -2-hydroxypropane

When a mixture of several kinds of diphenylsulfone cross-linkable compounds represented by the general formula (1) is used in combination, the composition is preferably only the value of a of the compound represented by the following general formula (3). Contains two or more different types. With such a compound, the production method is also simple, and compounds having different values of a can be synthesized at once with an arbitrary content ratio by changing the reaction ratio of the raw materials.

[0017]

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(Wherein X, Y, R ₁ , m, and a are the same as those described above) In the general formula (3), particularly, the compound represented by a = 0 is disclosed in JP-A-7-149713, International Publication WO93 / 0
6074, WO95 / 33714, typically 1,3-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] -2-hydroxypropane 1,1-bis [4- (4 -Hydroxyphenylsulfonyl) phenoxy] methane 1,2-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] ethane 1,3-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] propane 1,4-bis [ 4- (4-hydroxyphenylsulfonyl) phenoxy] butane 1,5-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] pentane 1,6-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] hexane α, α'-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] p-xylene α, α'-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] -m-xylene α, α'-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] -o-xylene 2,2 '-Bis [4- (4-hydroxyphenylsulfonyl) phenoxy] diethyl ether 4,4'-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] dibutyl ether 1,2-bis [4- (4-hydroxyphenyl) Sulfonyl) phenoxy] ethylene 1,4-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] -2-butene.

The compound represented by the general formula (1) is
According to the method described in WO 97/16420,
Hydroxydiphenylsulfone derivative or 2,4 '
-Basic compounds such as dihydroxydiphenyl sulfone derivatives
It is obtained by reacting in the presence of a substance. Used in the present invention
The compound may be used alone or synthesized by such means.
Contains two or more diphenylsulfone bridged compounds
An example of a synthesis example is shown below. (Synthesis Example 1) Sodium hydroxide 1 in 21.2 g of water
After adding 6.0 g (0.4 mol) and dissolving, BPS 50.
0 g (0.2 mol) were added. Next, at 105 ° C,
14.2-g (2-chloroethyl) ether (0.10
Mol) and reacted at 110 ° C. to 115 ° C. for 5 hours.
Was. After completion of the reaction, 375 ml of water was added to the reaction solution, and 90
Stirred at C for 1 hour. After cooling to room temperature,
The precipitate was separated by filtration to obtain 39.3 g of white crystals.
88% yield from bis (2-chloroethyl) ether
Met. By high performance liquid chromatography:
Composition. However, the column is Mightysil
RP-18 (Kanto Chemical), mobile phase is CH _ThreeCN: H
_TwoO: 1% H_ThreePO_Four = 700: 300: 5, UV wavelength is
260 nm.

[0020]

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A = 0: retention time 1.9 minutes: area% 3
2.9 a = 1: Retention time 2.3 minutes: Area% 21.7 a = 2: Retention time 2.7 minutes: Area% 12.8 a = 3: Retention time 3.4 minutes: Area% 8. 8 a = 4: Retention time 4.2 min: Area% 5.8 a = 5: Retention time 5.4 min: Area% 3.5 a = 6: Retention time 7.0 min: Area% 2.2 a = 7: retention time 9.0 minutes: area% 1.7 a = 8: retention time 11.8 minutes: area% 1.3 a = 9: retention time 15.4 minutes: area% 1.3

(Synthesis Examples 2 to 4)
Ratio of BPS to bis (2-chloroethyl) ether
Is 1.5: 1, 2.5: 1, 3.0: 1,
Such a composition could be obtained. When 1.5: 1, a = 0 20.8, a = 1.
0, a = 2 14.2, a = 3 7.9, a = 4 3.
When 9 2.5: 1, a = 0 49.6, a = 125.
9, a = 2 11.4, a = 3 5.3, a = 4
4 When 3.0: 1, a = 0 56.9, a = 1 24.
9, a = 2 9.6, a = 3 3.7, a = 4
3 (Synthesis Example 5) 48% aqueous sodium hydroxide solution 10.0
g and N, N'-dimethylacetamide (155 g)
30.0 g (0.12 mol) of BPS was added to the combined solution.
I got it. Dissolved in xylene after heating to 80 ° C and dissolving in 15g
Α, α'-dichloro-p-xylene 10.5 g
(0.06 mol) was slowly added dropwise. After dropping,
A thermal aging reaction was performed at a temperature for 2 hours. 900ml after aging
And the precipitated crystal was separated by filtration. This crude crystal
Was washed with methanol, filtered and dried.
g was obtained. Measure purity by high performance liquid chromatography
The main composition was as follows. α, α'-bis [4- (4-hydroxyphenylsulfo
Nyl) phenoxy] -p-xylene 59.1% 4,4'-bis [4- (4-hydroxyphenylsulfo
Nyl) phenyl-1,4-phenylenebismethyleneoxy
C] diphenylsulfone 23.1% α, α'-bis [4- [4- [4- (4-hydroxyf
Enylsulfonyl) phenyl-1,4-phenylenebis
[Methyleneoxy] phenylsulfonyl] phenoxy]-
p-Xylene 11.1% In the present invention, the desired effect on the above problem is inhibited.
Colorless or light-colored basic dyes
Conventionally known color developers can be used in combination. However,
It is desirable to add a very small amount, which is represented by the general formula (1).
Conventionally known developer for the compound is about 0.01 to 1 part.
is there. Examples of such a developer include, for example, JP-A-3-207.
No. 688, Japanese Patent Application Laid-Open No. 5-24366.
Enols A, 4-hydroxybenzoic acid esters, 4
-Hydroxyphthalic acid diesters, phthalic acid monoes
Ters, bis- (hydroxyphenyl) sulfides,
4-hydroxyphenylaryl sulfones, 4-hydrido
Roxyphenylarylsulfonate, 1,3-di
[2-di (hydroxyphenyl) -2-propyl] -b
Benzenes, 4-hydroxybenzoyloxybenzoic acid
Stels, bisphenol sulfones, JP-A-8-59
The aminobenzenesulfonamide derivative described in No. 603 is
Is exemplified. In the present invention, the diphth represented by the general formula (2)
Contains a phenylsulfone derivative. (Note that this compound
May be referred to as sensitizer 1. ) Content is organic developer
Good sensitivity when used in a ratio of 0.1 to 2 parts per part
preferable. In the general formula (2), R ₇~ R₁₂Impedes the sensitizing effect
Any substituent that does not harm may be used.
Are hydrogen, alkyl, halogen, nitro
Groups, alkoxy groups, cyano groups, allyloxy groups and the like.
It is. Particularly preferred are a hydrogen atom, C₁~ C₆The alkyl of
Group, C₁~ C₆Alkoxy, halogen, nitro
It is. Specific examples of the compound represented by the general formula (2)
When shown, 2-1 to 2-46 shown below are exemplified,
It is not limited to these. In addition, these compounds
The substances may be used alone or as a mixture of two or more.

[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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[0029]

Embedded image The present invention further contains di (p-methylbenzyl) oxalate or 1,2-bis (phenoxymethyl) benzene. (This compound is sometimes referred to as “sensitizer 2”.) The content is arbitrary, but is usually about 0.1 to 2 parts with respect to 1 part of the organic developer of the general formula (1). preferable.

As the leuco-developing basic leuco dye used in the present invention, any of those known in the field of conventional pressure-sensitive or heat-sensitive recording paper can be used, and there is no particular limitation. Compounds, fluorane compounds, fluorene compounds, divinyl compounds and the like are preferred. Specific examples of typical colorless or pale color dyes (dye precursors) are shown below. These dye precursors may be used alone or in combination of two or more. <Triphenylmethane leuco dye> 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide [also known as crystal violet lactone] 3,3-bis (p-dimethylaminophenyl) phthalide [also known as malachite green] Lactone] <Fluoran leuco dye> 3-Diethylamino-6-methylfluoran 3-Diethylamino-6-methyl-7-anilinofluoran 3-Diethylamino-6-methyl-7- (o, p-dimethylanilino) Fluoran 3-diethylamino-6-methyl-7-chlorofluoran 3-diethylamino-6-methyl-7- (m-trifluoromethylanilino) fluoran 3-diethylamino-6-methyl-7- (o-chloroanilino) fluoran 3-diethylamino-6-methyl-7- ( -Chloroanilino) fluoran 3-diethylamino-6-methyl-7- (o-fluoroanilino) fluoran 3-diethylamino-6-methyl-7- (m-methylanilino) fluoran 3-diethylamino-6-methyl-7-n- Octylanilinofluoran 3-diethylamino-6-methyl-7-n-octylaminofluoran 3-diethylamino-6-methyl-7-benzylanilinofluoran 3-diethylamino-6-methyl-7-dibenzylanilino Fluoran 3-diethylamino-6-chloro-7-methylfluoran 3-diethylamino-6-chloro-7-anilinofluoran 3-diethylamino-6-chloro-7-p-methylanilinofluoran 3-diethylamino- 6-ethoxyethyl-7-anilinofluoran 3- Diethylamino-7-methylfluorane 3-diethylamino-7-chlorofluorane 3-diethylamino-7- (m-trifluoromethylanilino) fluoran 3-diethylamino-7- (o-chloroanilino) fluoran 3-diethylamino-7- (P-chloroanilino) fluoran 3-diethylamino-7- (o-fluoroanilino) fluoran

3-diethylamino-benzo [a] fluoran 3-diethylamino-benzo [c] fluoran 3-dibutylamino-6-methyl-fluoran 3-dibutylamino-6-methyl-7-anilinofluoran 3-dibutylamino -6-methyl-7- (o, p-dimethylanilino) fluoran 3-dibutylamino-6-methyl-7- (o-chloroanilino) fluoran 3-dibutylamino-6-methyl-7- (p-chloroanilino) Fluoran 3-dibutylamino-6-methyl-7- (o-fluoroanilino) fluoran 3-dibutylamino-6-methyl-7- (m-trifluoromethylanilino) fluoran 3-dibutylamino-6-methyl- Chlorofluorane 3-dibutylamino-6-ethoxyethyl-7-anilinofluora 3-dibutylamino-6-chloro-7-anilinofluoran 3-dibutylamino-6-methyl-7-p-methylanilinofluoran 3-dibutylamino-7- (o-chloroanilino) fluoran 3-dibutyl Amino-7- (o-fluoroanilino) fluoran 3-di-n-pentylamino-6-methyl-7-anilinofluoran 3-di-n-pentylamino-6-methyl-7- (p-
Chloroanilino) fluorane 3-di-n-pentylamino-7- (m-trifluoromethylanilino) fluoran 3-di-n-pentylamino-6-chloro-7-anilinofluoran 3-di-n-pentyl Amino-7- (p-chloroanilino) fluoran 3-pyrrolidino-6-methyl-7-anilinofluoran 3-piperidino-6-methyl-7-anilinofluoran 3- (N-methyl-N-propylamino) -6-methyl-7-anilinofluoran

3- (N-methyl-N-cyclohexylamino) -6-methyl-7-anilinofluoran 3- (N-ethyl-N-cyclohexylamino) -6
Methyl-7-anilinofluoran 3- (N-ethyl-N-xylamino) -6-methyl-
7- (p-chloroanilino) fluoran 3- (N-ethyl-p-toluidino) -6-methyl-
7-anilinofluoran 3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluoran 3- (N-ethyl-N-isoamylamino) -6-chloro-7-anilino Fluoran 3- (N-ethyl-N-tetrahydrofurfurylamino) -6-methyl-7-anilinofluoran 3- (N-ethyl-N-isobutylamino) -6-methyl-7-anilinofluoran 3- (N-ethyl-N-ethoxypropylamino) -6
-Methyl-7-anilinofluoran 3-cyclohexylamino-6-chlorofluoran 2- (4-oxahexyl) -3-dimethylamino-6
-Methyl-7-anilinofluoran 2- (4-oxahexyl) -3-diethylamino-6
-Methyl-7-anilinofluoran 2- (4-oxahexyl) -3-dipropylamino-
6-methyl-7-anilinofluoran 2-methyl-6-p- (p-dimethylaminophenyl)
Aminoanilinofluoran 2-methoxy-6-p- (p-dimethylaminophenyl) aminoanilinofluoran

2-Chloro-3-methyl-6-p- (p-
Phenylaminophenyl) aminoanilinofluoran 2-chloro-6-p- (p-dimethylaminophenyl)
Aminoanilinofluoran 2-nitro-6-p- (p-diethylaminophenyl)
Aminoanilinofluoran 2-amino-6-p- (p-diethylaminophenyl)
Aminoanilinofluoran 2-diethylamino-6-p- (p-diethylaminophenyl) aminoanilinofluoran 2-phenyl-6-methyl-6-p- (p-phenylaminophenyl) aminoanilinofluoran 2- Benzyl-6-p- (p-phenylaminophenyl) aminoanilinofluoran 2-hydroxy-6-p- (p-phenylaminophenyl) aminoanilinofluoran 3-methyl-6-p- (p-dimethyl Aminophenyl)
Aminoanilinofluoran 3-diethylamino-6-p- (p-diethylaminophenyl) aminoanilinofluoran 3-diethylamino-6-p- (p-dibutylaminophenyl) aminoanilinofluoran 2,4-dimethyl- 6-[(4-Dimethylamino) anilino] -fluorane <Fluorene leuco dye> 3,6,6′-tris (dimethylamino) spiro [fluorene-9,3′-phthalide] 3,6,6′-tris (Diethylamino) spiro [fluorene-9,3'-phthalide] <Divinyl leuco dye> 3,3-bis- [2- (p-dimethylaminophenyl)
-2- (p-methoxyphenyl) ethenyl] -4,5
6,7-tetrabromophthalide 3,3-bis- [2- (p-dimethylaminophenyl)
-2- (p-methoxyphenyl) ethenyl] -4,5
6,7-tetrachlorophthalide 3,3-bis- [1,1-bis (4-pyrrolidinophenyl) ethylene-2-yl] -4,5,6,7-tetrabromophthalide 3,3- Bis- [1- (4-methoxyphenyl) -1-
(4-pyrrolidinophenyl) ethylene-2-yl]-
4,5,6,7-tetrachlorophthalide

<Others> 3- (4-Diethylamino-2-ethoxyphenyl)-
3- (1-ethyl-2-methylindol-3-yl)
-4-azaphthalide 3- (4-diethylamino-2-ethoxyphenyl)-
3- (1-octyl-2-methylindol-3-yl) -4-azaphthalide 3- (4-cyclohexylethylamino-2-methoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) ) -4-Azaphthalide 3,3-bis (1-ethyl-2-methylindole-3
-Yl) phthalide 3,6-bis (diethylamino) fluoran-γ- (3
'-Nitro) anilinolactam 3,6-bis (diethylamino) fluoran-γ- (4
'-Nitro) anilinolactam 1,1-bis- [2', 2 ', 2 ", 2" -tetrakis- (p-dimethylaminophenyl) -ethenyl] -2,
2-dinitrileethane 1,1-bis- [2 ', 2', 2 ", 2" -tetrakis- (p-dimethylaminophenyl) -ethenyl] -2-
β-naphthoylethane 1,1-bis- [2 ′, 2 ′, 2 ″, 2 ″ -tetrakis- (p-dimethylaminophenyl) -ethenyl] -2,
2-Diacetylethane bis- [2,2,2 ', 2'-tetrakis- (p-dimethylaminophenyl) -ethenyl] -methylmalonic acid dimethyl ester In the present invention, a range in which the desired effect on the above-mentioned problem is not impaired A conventionally known sensitizer can be used. Such sensitizers include ethylene bisamide, montanic acid wax, polyethylene wax, 1,2-di-
(3-methylphenoxy) ethane, p-benzylbiphenyl, β-benzyloxynaphthalene, 4-biphenyl-p-tolyl ether, m-terphenyl, 1,2-diphenoxyethane, 4,4′-ethylenedioxy- Bis-benzoic acid dibenzyl ester, dibenzoyloxymethane, 1,2-di (3-methylphenoxy) ethylene,
1,2-diphenoxyethylene, bis [2- (4-methoxy-phenoxy) ethyl] ether, methyl p-nitrobenzoate, dibenzyl oxalate, di (p-chlorobenzyl) oxalate, dibenzyl terephthalate, p- Benzyl benzyloxybenzoate, di-p-tolyl carbonate, phenyl-α-naphthyl carbonate, 1,4-diethoxynaphthalene, 1-hydroxy-2-naphthoic acid phenyl ester, 4- (m-methylphenoxymethyl) biphenyl Examples can be given, but the invention is not particularly limited thereto. These sensitizers may be used alone or in combination of two or more.

As the binder used in the present invention, completely saponified polyvinyl alcohol having a degree of polymerization of 200 to 1900, partially saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, butyral-modified polyvinyl alcohol Alcohol, other modified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, ethyl cellulose, cellulose derivatives such as acetyl cellulose,
Styrene-maleic anhydride copolymer, styrene-butadiene copolymer, polyvinyl chloride, polyvinyl acetate, polyacrylamide, polyacrylate, polyvinyl butyl laral, polystyrene and their copolymers,
Examples thereof include polyamide resin, silicone resin, petroleum resin, terpene resin, ketone resin, and cumaro resin.
These high-molecular substances are used by dissolving them in solvents such as water, alcohols, ketones, esters, and hydrocarbons. They can be used together. Further, in the present invention, 4,4′-butylidene (6-t-butyl-3-) is used as an image stabilizer that exhibits an oil resistance effect of a recorded image within a range that does not impair the desired effect on the above-mentioned problem.
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-butylphenylbutane, 4-benzyloxy-4 '-(2,3-epoxy-2-methylpropoxy) Diphenyl sulfone,
Epoxy resin or the like can also be added. As the filler used in the present invention, silica, calcium carbonate, kaolin, calcined kaolin, diatomaceous earth, talc, titanium oxide,
Examples include inorganic or organic fillers such as aluminum hydroxide. In addition, lubricants such as waxes, benzophenone-based and triazole-based ultraviolet absorbers, waterproofing agents such as glyoxal, dispersants, defoamers, antioxidants,
A fluorescent dye or the like can be used. The amounts of the developer and dye used in the thermosensitive recording medium of the present invention, and the types and amounts of other various components are determined according to the required performance and recording suitability, and are not particularly limited. For 1 part of the developer represented by (1), 0.1 to 2 parts of a basic colorless dye and 0.5 to 4 parts of a filler are used. It is. The desired heat-sensitive recording sheet can be obtained by applying the coating solution having the above composition to any support such as paper, recycled paper, synthetic paper, film, plastic film, foamed plastic film, and nonwoven fabric. Further, a composite sheet obtained by combining these may be used as the support.

Further, an overcoat layer of a polymer substance or the like can be provided on the thermosensitive coloring layer for the purpose of enhancing the storage stability. In addition, an undercoat layer of a polymer material containing a filler or the like can be provided below the heat-sensitive layer for the purpose of increasing the coloring sensitivity. The aforementioned organic developer, basic colorless dye and optionally added materials are pulverized to a particle size of several microns or less by a pulverizer such as a ball mill, an attritor, a sand glider or an appropriate emulsifier, and a binder. And various additive materials are added according to the purpose to form a coating liquid. Means for applying is not particularly limited,
Coating can be carried out according to well-known conventional techniques. 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 bill blade coater, and a roll coater is appropriately selected and used.

[0037]

EXAMPLES The thermosensitive recording medium of the present invention will be described below with reference to examples. In the description, parts and% represent parts by weight and% by weight, respectively, unless otherwise specified. Example 1 In Example 1, a compound (1-1) was used as a color developer and 3-dibutylamino-6-methyl-7-anilinofluoran (ODB) as a colorless basic dye. -2), Compound (2-2) and 1, as sensitizers
This is an example using 2-di (phenoxymethyl) benzene (hereinafter abbreviated as DPMB). A developer dispersion having the following composition, a basic colorless dye dispersion, and sensitizer dispersions 1 and 2 were separately wet-ground by a sand grinder until the average particle diameter became 1 μm. Developer Dispersion Developer [(1-1) compound] 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts Basic colorless dye dispersion 3-dibutylamino-6-methyl-7 -Anilinofluoran (ODB-2) 2.0 parts 10% aqueous solution of polyvinyl alcohol 4.6 parts Water 2.6 parts Sensitizer dispersion 1 Compound (2-2) 4.0 parts 10% aqueous solution of polyvinyl alcohol 18 8.8 parts water 11.2 parts Sensitizer dispersion liquid 2,1,2-di (phenoxymethyl) benzene 4.0 parts 10% aqueous solution of polyvinyl alcohol 8.8 parts water 11.2 parts After mixing and stirring, a coating solution was prepared. Developer dispersion 36.0 parts Basic colorless dye [ODB-2] dispersion 9.2 parts Sensitizer dispersion 1 34.0 parts Sensitizer dispersion 2 34.0 parts Kaolin clay (50% dispersion) Liquid) 12.0 parts After applying the above coating liquid on one side of 50 g / m ² base paper,
After drying, the sheet is treated with a super calender so that the smoothness is 500 to 600 seconds, and the coating amount is 6.0.
g / m ² was obtained.

[Examples 2 to 5] Compound (1-1) in the developer dispersion of Example 1 was replaced with compound (1-1) (Example 2) and compound (1-2) ( Example 3), compound (1
-13) (Example 4) and Compound (1-17) (Example 5), and 1,2-di (phenoxymethyl) benzene in the sensitizer dispersion was replaced with (p-methylbenzyl oxalate) ) (Hereinafter abbreviated as PMBO) (Examples 2 to 5), except that a thermosensitive recording medium was obtained in the same manner as in Example 1. Examples 6 and 7 A thermosensitive recording medium was prepared in the same manner as in Examples 1 and 2, except that the compound (1-1) in the developer dispersion of Examples 1 and 2 was changed to the compound of Synthesis Example 1. Obtained. Examples 8 and 9 A thermosensitive recording medium was prepared in the same manner as in Examples 1 and 2, except that the compound (1-1) in the developer dispersions of Examples 1 and 2 was changed to the compound of Synthesis Example 2. Obtained. [Examples 10 and 11] A thermosensitive recording medium was prepared in the same manner as in Examples 1 and 2, except that the compound (1-1) in the developer dispersion of Examples 1 and 2 was changed to the compound of Synthesis Example 3. Obtained. [Examples 12 and 13] A thermosensitive recording medium was prepared in the same manner as in Examples 1 and 2, except that the compound (1-1) in the developer dispersion of Examples 1 and 2 was changed to the compound of Synthesis Example 4. Obtained. [Examples 14 and 15] A thermosensitive recording medium was prepared in the same manner as in Examples 1 and 2, except that the compound (1-1) in the developer dispersion of Examples 1 and 2 was changed to the compound of Synthesis Example 5. Obtained.

[Examples 16 to 18] ODB-2 in the basic colorless dye dispersion of Example 7 was replaced with 3-diethylamino-6-methyl-7-anilinofluoran (ODB) (Example 16). -(N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluoran (S-205) (Example 17) 3-Diethylamino-7- (m-trifluoromethylanilino) fluoran (Black-100) A thermosensitive recording medium was obtained in the same manner as in Example 7, except that Example 18 was changed. [Examples 19 and 20] Compound (2-1) in sensitizer dispersion 1 of Example 7 was replaced with compound (2-8) (Example 19) and compound (2-9) (Example 20), respectively. ) To obtain a thermosensitive recording medium in the same manner as in Example 7. [Example 21] The amount of the basic colorless dye dispersion using ODB-2 of Example 7 was changed, and the basic colorless dye dispersion using S-205 was further added to obtain the following formula. A heat-sensitive recording material was obtained in the same manner as in Example 7 except for the above. Developer dispersion 36.0 parts Basic colorless dye [ODB-2] dispersion 4.6 parts Basic colorless dye [S-205] dispersion 4.6 parts Sensitizer dispersion 1 34.0 parts Increase Sensitizer dispersion 2 34.0 parts Kaolin clay (50% dispersion) 12.0 parts

Comparative Example 1 Sensitizer dispersion liquid 2 in Example 7
Was obtained in the same manner as in Example 7 except that was not blended. Comparative Example 2 A thermosensitive recording medium was obtained in the same manner as in Example 6, except that the sensitizer dispersion 1 in Example 6 was not used. Comparative Example 3 A thermosensitive recording medium was obtained in the same manner as in Example 7, except that the sensitizer dispersion 1 in Example 7 was not used. [Comparative Example 4] The compound of Synthesis Example 1 in the developer dispersion liquid of Example 6 was replaced with 4,4'-isopropylidenediphenol (BP
A heat-sensitive recording material was obtained in the same manner as in Example 6 except that A) was changed. [Comparative Example 5] The compound of Synthesis Example 1 in the developer dispersion of Example 7 was replaced with 4,4'-isopropylidenediphenol (BP
A heat-sensitive recording material was obtained in the same manner as in Example 7 except that A) was changed.

<Evaluation of thermal recording medium> The prepared thermal recording medium was measured using a TH-PMD (a thermal recording paper printing tester manufactured by Okura Electric Co., Ltd. with a thermal head manufactured by Kyocera Corporation).
Printing was performed at an applied energy of 0.30 and 0.38 mj / dot. The recording density of the recording unit was measured using a Macbeth densitometer (RD-
914, using an amber filter) (see Tables 1 and 2). <Evaluation of plasticizer resistance> A vinyl chloride wrap (Hi-wrap KMA manufactured by Mitsui Toatsu) was wrapped around a paper tube in a single layer, and the thermosensitive recording medium recorded by the printer (0.38 mj / dot) was adhered thereon, and After a triple wrap of PVC wrap was left at 40 ° C. for 24 hours, the Macbeth densities of the image area and the ground color area were measured (see Tables 1 and 2).

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

According to the present invention, while maintaining image stability such as plasticizer characteristic, which is a characteristic of the compound represented by the general formula (1), high color sensitivity and good recorded image can be obtained. ing. Therefore, a clear image can be obtained with high sensitivity even with a small amount of energy.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Daisuke Imai 5-2-1-1, Oji, Kita-ku, Tokyo Nippon Paper Industries Co., Ltd. (72) Inventor Yoshihide Kimura 5-2-1-1, Oji, Kita-ku, Tokyo F-term (reference) in Nippon Paper Industries Co., Ltd. 2H026 AA07 BB30 DD02 DD19 DD45 DD53

Claims (1)

[Claims] 1. A thermosensitive recording medium comprising a support having thereon a heat-sensitive coloring layer containing a colorless or light-colored basic colorless dye and an organic color developing agent as main components, wherein said heat-sensitive color developing layer comprises an organic color developing agent. Contains at least one diphenylsulfone cross-linked compound represented by the following general formula (1), further contains a diphenylsulfone derivative represented by the following general formula (2), and di (p-methylbenzyl) oxalate Alternatively, a heat-sensitive recording medium containing 1,2-bis (phenoxymethyl) benzene. Embedded image [In the formula, X and Y each represent a hydrocarbon group which may be different from each other and may have a straight or branched chain and may have a saturated, unsaturated or ether bond having 1 to 12 carbon atoms; Or Or (R represents a methylene group or an ethylene group, and T represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). R ₁ ~
R ₆ each independently represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group. M, n, p, q,
r, t represents an integer of 0 to 4, is 2 or more when R ₁
To R ₆ may be different from each other. a is 0 to 10
Represents an integer. [Formula 4] (R _{7 to} R ₁₂ represent a hydrogen atom, an alkyl group, a halogen atom, a nitro group, an alkoxy group, a cyano group, or an allyloxy group.)