JPH07149713A - Sulfonyl compound, its production and heat-sensitive recording material using the same - Google Patents

Abstract

PURPOSE:To provide a novel sulfonyl compound useful as a color-developing agent giving heat-sensitive recording materials, high in sensitivity, and excellent in storage stability. CONSTITUTION:A sulfonyl compound is expressed by formula I, namely alpha,alpha'- bis[4-(p-hydroxyphenylsulfonyl)phenoxy]-p-xylene of formula II, alpha,alpha'-bis[4-(p- hydroxyphenylsulfonyl)phenoxy]-m-xylene of formula III, or alpha,alpha'-bis[4-(p- hydroxyphenylsulfonyl)phenoxy]-o-xylene. The compound of formula I is obtained by reacting a compound of formula V (X is Cl, Br) with 4,4'- dihydroxydiphenylsulfone in the presence of a basic substance in water or in an organic solvent containing the water. A recording material obtained from the new compound of formula I is excellent in a color-generating property, water resistance and plasticizer resistance, and is little in the fogging of the colored texture with time.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermal recording material,
More specifically, when used as a color developer, it has high sensitivity and little background fog, and the storability of recorded images, especially water resistance,
The present invention relates to a sulfonyl compound having excellent plasticizer resistance.

[0002]

2. Description of the Related Art Conventionally, heat-sensitive recording materials utilizing a thermal color reaction between a basic dye and a color developer have been well known. Above all, as a developer
2,2'-bis (4-hydroxyphenyl) propane and 4-hydroxy-4'-isopropoxydiphenyl sulfone are well known (for example, Japanese Patent Publication No. 63-4).
No. 6067, Japanese Patent Publication No. 3-54655, etc.). However, the heat-sensitive recording materials using these have storage stability of a color image,
In particular, further improvement is required in water resistance and plasticizer resistance.

[0003]

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted extensive studies in order to find a color developing agent capable of obtaining a thermosensitive recording material having high sensitivity and excellent storage stability. The present invention has been accomplished by discovering the sulfonyl compounds represented.

[0004]

[Chemical 3] That is, the present invention is characterized by using at least one compound represented by the general formula (1) as a color developing agent in a heat-sensitive recording material containing a basic dye, a color developing agent, a sensitizer and the like. The present invention relates to a thermosensitive recording material.

The compounds represented by the general formula (1) according to the present invention include the compounds represented by the formulas (1-a), (1-b), and (1-
It is a compound represented by c).

Α, α'-bis {4- (p-hydroxyphenylsulfonyl) phenoxy} -p-xylene

[0007]

[Chemical 4] α, α′-bis {4- (p-hydroxyphenylsulfonyl) phenoxy} -m-xylene

[0008]

[Chemical 5] α, α'-bis {4- (p-hydroxyphenylsulfonyl) phenoxy} -o-xylene

[0009]

[Chemical 6] Next, a method for producing the compounds represented by the formulas (1-a), (1-b) and (1-c) will be described.

That is, the compound represented by the general formula (2)

[0011]

[Chemical 7] [In Formula (2), X represents a chlorine atom or a bromine atom. ], 4,4′-dihydroxydiphenyl sulfone and a basic substance are reacted in water or an organic solvent containing water to produce the compound.

Examples of the compound of the general formula (2) include α, α '
-Dichloro-p-xylene, α, α'-dibromo-p-
Xylene, α, α′-dichloro-m-xylene, α,
α'-dibromo-m-xylene, α, α'-dichloro-
o-xylene and α, α′-dibromo-o-xylene, and the amount of these used is 0.2 to 0.6 mol, preferably 0.3 to 0, relative to 1 mol of 4,4′-dihydroxydiphenyl sulfone. 0.5 mol.

As the basic substance, sodium hydroxide,
Sodium carbonate, potassium hydroxide, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonia, sodium methylate, triethylamine and the like are preferable, and these are used in an amount of 0.1 mol per mol of 4,4′-dihydroxydiphenyl sulfone. ˜0.8 mol, preferably 0.3 to 0.6 mol.

The reaction solvent used is water or an organic solvent containing water in order to remove the reaction product from the reaction system to prevent polymerization and obtain the compound of the general formula (1) in high purity and high yield. Is preferred. As the organic solvent, hexane, heptane,
Benzene, toluene, xylene, methanol, ethanol, isopropyl alcohol, butanol, N, N'-
Examples thereof include dimethylformaldehyde, N, N'-dimethylacetaldehyde, dimethylsulfoxide, dioxane, tetrahydrofuran, ethyl ether, acetone, sulfolane and the like.

The solvent for dissolving the compound of the general formula (1), for example, N, N'-dimethylacetamide, N, N'-dimethylformamide, sulfolane, dimethylsulfoxide, etc., is reacted under anhydrous condition or in a condition of low water content. When this is done, a large amount of polymerized product is generated, and the general formula (1)
It significantly reduces the purity of the compound. The mixing ratio of water and the organic solvent varies depending on the kind of the organic solvent, but is usually water 1: organic solvent 0 to 15 (parts by weight).

The reaction temperature is from 20 ° C to the boiling point, preferably from 50 ° C to the boiling point, and the reaction time is usually from 1 to
10 hours.

A general method for producing the sulfonyl compound of the present invention will be described below. 4,4'-dihydroxydiphenyl sulfone and 2 to 5 times the amount of water in the reactor,
With respect to 1 mol of 4'-dihydroxydiphenyl sulfone,
Charge 0.3 to 0.6 mol of basic substance, raise the temperature from 50 ° C. to the reflux temperature, and when the reaction system becomes uniform,
With respect to 1 mol of 4'-dihydroxydiphenyl sulfone,
A compound of the formula (2) in an amount of 0.3 to 0.5 mol is slowly added dropwise. After completion of the reaction, water is separated from the reaction product and, if necessary, purified by a recrystallization method to obtain the compound of the general formula (1).

The melting point of the compound of formula (1-a) according to the present production method is 240 to 245 ° C., the melting point of the compound of formula (1-b) is 185 to 190 ° C., and the melting point of the compound of formula (1-c) is 1
It is 55-160 degreeC.

In the heat-sensitive recording material according to the present invention, the amount of the color developer used is 50 parts with respect to 100 parts by weight of the basic dye.
To 600 parts by weight, preferably 100 to 400 parts by weight.

The amount of the sensitizer used is 100 for the basic dye.
50 to 800 parts by weight, preferably 10 parts by weight
0 to 500 parts by weight.

The basic dye used in the present invention includes:
Triarylmethane compounds, diarylmethane compounds, rhodamine-lactam compounds, fluorane compounds, indolylphthalide compounds, pyridine compounds,
Examples include spiro compounds and fluorene compounds. Among them, 3-N, N-di-ethylamino-6-methyl-7-anilinofluorane, 3-N, N-di-butylamino-6-methyl-7-anilinofluorane, 3-
(N-isopentyl-N-ethyl) -6-methyl-7-
Anilinofluorane, 3- (N-cyclohexyl-N-
Methyl) -6-methyl-7-anilinofluorane, 3-
Representative examples include N, N-di-ethyl-6-chloro-7-anilinofluorane and the like.

These basic dyes may be used alone or in admixture of two or more for the purpose of adjusting the color tone of a color image and obtaining a multicolor heat-sensitive recording material.

The heat-sensitive recording material according to the present invention is characterized by using at least one compound represented by the general formula (1) as a developer, and the desired effects of the present invention can be obtained. A developer other than the compound represented by the general formula (1) may be used in combination as long as it does not impair it. Examples of these compounds include phenol-based compounds and salicylic acid-based compounds. 2,2′-bis (4-hydroxyphenyl) propane, 4-hydroxybenzoic acid benzyl ester, 4-hydroxy-4′-isopropoxydiphenyl. Typical examples include sulfone, 3,5-di-tert-butylsalicylic acid (or zinc salt), and 3,5-α-methylbenzylsalicylic acid (or zinc salt).

Further, examples of the sensitizer used in the present invention include nitrogen-containing compounds, ester compounds, hydrocarbon compounds, ether compounds, sulfone compounds and the like, but stearic acid amide, 4-benzyloxybenzoic acid. Benzyl ester, oxalic acid dibenzyl ester, di (4-methylphenyl) carbonate, 4-benzylbiphenyl, m-terphenyl, 1,2-bis (3-methylphenoxy) ethane, 1,2-bis (phenoxy) ethane , Diphenyl sulfone, etc. are exemplified as typical ones. These sensitizers may be used alone or in combination of two or more.

The thermal recording paper according to the present invention can be manufactured by a known method without using a special method. Generally, for example, a basic dye, a color developer, a sensitizer, a pigment, a metal soap, a wax, a surfactant, etc., in an aqueous medium containing a water-soluble binder, by a means such as a ball mill or a sand mill, usually 3 μm Hereinafter, the coating liquid can be adjusted after pulverizing and dispersing to a particle size of preferably 1.5 μm or less.

Examples of such pigments include calcium carbonate, magnesium carbonate, titanium oxide, kaolin, silica and amorphous silica. Examples of the metal soap include zinc stearate and calcium stearate. Examples of the wax include paraffin wax, microcrystalline wax, polyethylene wax and the like. Examples of the surfactant include sulfosuccinic acid-based alkali metal salts and the like.

In the heat-sensitive recording material of the present invention, the method of forming the recording layer is not particularly limited, and the recording layer can be formed according to a conventionally known technique. For example, the coating liquid for the heat-sensitive recording layer is applied on a support with an appropriate coating device such as an air knife coater, a braider coater, a bar coater, a gravure coater, a curtain coater, or a wire bar, and dried to form a recording layer. You can

The coating amount of the coating liquid is not particularly limited, and is generally 1.0 to 10 by dry weight with respect to the surface of the support.
It is in the range of 12 gr / m ² , preferably 2.0 to 8 gr / m ² . As the support, paper, plastic sheet, synthetic paper or the like is used.

[0029]

EXAMPLES The present invention will be described below with reference to examples. (Example 1) 4,4'-in a 1-liter 4-neck reactor
Dihydroxydiphenyl sulfone 100gr, water 500
Gr and 48% aqueous sodium hydroxide solution (33.3 gr) were charged, and the mixture was heated to 80 ° C. under a nitrogen gas atmosphere and dissolved, and then α, α′-dichloro-p-dissolved in 50 g of p-xylene while vigorously stirring the inside of the reactor. 35 gr of xylene was slowly added dropwise.

At the same time as the dropping, a crystalline substance was deposited. After completion of the dropping, an aging reaction was performed at the same temperature for 2 hours. After cooling to room temperature, the crystalline substance was filtered off and purified by recrystallization with n-butanol to obtain white crystalline powder 114gr. Melting point 245 [deg.] C. From the results of IR analysis, H-NMR analysis and elemental analysis of this product, it was confirmed that this product was α, α′-bis {4- (p-hydroxyphenylsulfonyl) phenoxy} -p-xylene.

Elemental analysis value (%) C: H; S; measured value 63.9 4.5 10.5 calculated value 63.8 4.4 10.6 (as C ₃₂ H ₂₆ O ₈ S ₂ ).

Example 2 In Example 1, p-xylene was not used, but α, α'-dichloro-p-xylene was used.
112 g of white crystalline powder were obtained in the same manner except that α, α′-dichloro-m-xylene was used after being melted by heating.
Got Melting point 190 [deg.] C. IR analysis of this product, H-NM
From the results of R analysis and elemental analysis, this product was confirmed to be α, α′-bis {4- (p-hydroxyphenylsulfonyl) phenoxy} -m-xylene.

Elemental analysis value (%) C: H; S; measured value 63.7 4.5 10.5 calculated value 63.8 4.4 10.6 (as C ₃₂ H ₂₆ O ₈ S ₂ ).

(Example 3) In Example 1, α, α'-dichloro-p-xylene was replaced with α, α'-dichloro-o-
When xylene was used and reacted in the same manner as in Example 1, an oily substance was formed at the same time as the dropping. After the completion of dropping, the oily substance was separated and recrystallized and purified with methanol to obtain 105 gr of white crystalline powder. Melting point 160 [deg.] C. IR of this thing
From the results of analysis, H-NMR analysis and elemental analysis, this product
It was confirmed to be α, α′-bis {4- (p-hydroxyphenylsulfonyl) phenoxy} -o-xylene.

Elemental analysis value (%) C: H; S; measured value 63.9 4.3 10.6 calculated value 63.8 4.4 10.6 (as C ₃₂ H ₂₆ O ₈ S ₂ ).

(Comparative Example 1) In Example 1, the solvent was changed to water, 500 g of N, N'-dimethylacetamide was used, and the reaction was carried out in the same manner as in Example 1. After aging, the mixture was poured into 3 liters of water and precipitated. The crystallized product was filtered off and dried.

This product contained a large amount of insoluble matter in n-butanol. P. C. It was confirmed by analysis that, in addition to the compound obtained in Example 1, a large amount of high molecular weight compounds was contained.

Example 4 Preparation of Basic Dye Dispersion Liquid 3-N, N'-di-butylamino-6-methyl-7-anilinofluorane (20 gr) in a concentration of 5% polyvinyl alcohol (trade name, manufactured by Kurera Co., Ltd.) Fine PVA-117) was finely pulverized in 80 gr of an aqueous solution for 20 hours using a ball mill to prepare a basic dye dispersion having an average particle size of 0.6 μm.

Preparation of color developer / sensitizer dispersion 20 gr of the color developer obtained in Example 1 and 20 gr of diphenyl sulfone were mixed with polyvinyl alcohol (PV
A-117) Finely pulverized in an aqueous solution of 60 gr for 20 hours using a ball mill to prepare a developer / sensitizer dispersion having an average particle size of 0.6 μm.

Preparation of Pigment Dispersion Calcium carbonate (trade name: Univer 70), 30 gr, manufactured by Shiraishi Kogyo Co., Ltd., 70 gr of water, and 1 g of 40% sodium hexametaphosphate aqueous solution were stirred for 15 minutes with a homogenizer at a rotation speed of 15,000 rpm to prepare a pigment. A dispersion was prepared.

Preparation of coating solution for heat-sensitive layer : 3 gr of basic dye dispersion, 6 gr of developer / sensitizer dispersion.
And 7 gr of pigment dispersion, and 31% concentration of hydrin Z
-7 (trade name of Chukyo Yushi Co., Ltd.) 1.0 gr and water 1
5 gr was mixed to obtain a heat-sensitive layer coating solution.

Preparation of heat-sensitive recording paper The heat-sensitive layer coating solution was applied onto a paper support using a wire bar so that the dry heat-sensitive layer would be 3 gr / m ^2.
Smoothness is 200 seconds after drying in an oven at ℃ (Beck method)
It was calendered so that

A printing test was conducted on the obtained thermal recording paper under the copy mode conditions of a FUJITSU FAX FF1700RX machine.

(Embodiment 5) In Embodiment 4, Embodiment 1
The same operation as in Example 4 was carried out except that the developer obtained in Example 2 was used instead of the developer obtained in 2 above.

(Embodiment 6) In Embodiment 4, Embodiment 1
The same operation as in Example 4 was repeated except that the developer obtained in Example 3 was used instead of the developer obtained in 3 above.

(Comparative Example 2) In Example 4, in Example 1
The same operation as in Example 4 was carried out except that 2,2′-bis (4-hydroxyphenyl) propane was used instead of the color developing agent obtained in.

Comparative Example 3 In Example 4, Example 1
The same operation as in Example 4 was carried out except that 4-hydroxy-4′-propoxydiphenyl sulfone was used instead of the color developer obtained in (4).

The following performance comparison tests were conducted on the heat-sensitive recording materials obtained in the respective examples and comparative examples.
It was the street.

Performance Comparison (Color Density) It was measured using a Macbeth densitometer.

(Heat resistance) The soiling of the background after standing at 60 ° C. for 24 hours was visually observed.

○ There was no change. △
Slightly colored.

× Significantly colored.

(Water resistance) Immersion in tap water at room temperature for 24 hours was carried out to measure the print density residual rate (%).

[0054]

(Plasticizer resistance) A printing paper is sprinkled on the outer periphery of the glass bottle, and Hilap V-450 (trade name) manufactured by Mitsui Toatsu Co., Ltd. is sprinkled on it five times, and the temperature is 40 ° C. for 2 times.
After leaving for 4 hours, the residual density (%) of print density was measured.

[0056]

[0057]

As is clear from the results shown in Table 1, the recording material of the present invention is excellent in color development, less fog on the background over time, and excellent in water resistance and plasticizer resistance.

[0059]

EFFECTS OF THE INVENTION The present invention provides a heat-sensitive recording material having high sensitivity, little background fog, and excellent storage stability of recorded images, especially water resistance and plasticizer resistance.

[Brief description of drawings]

1 is an infrared absorption spectrogram of the compound obtained in Example 1. FIG. The vertical axis represents the transmittance (%) and the horizontal axis represents the wave number (cm ^-1 ).

2 is an infrared absorption spectrogram of the compound obtained in Example 2. FIG.

3 is an infrared absorption spectrogram of the compound obtained in Example 3. FIG.

Claims (3)

[Claims] 1. A sulfonyl compound represented by the general formula (1). [Chemical 1] 2. A compound represented by the general formula (2), 4,
A method for producing a sulfonyl compound represented by the general formula (1), which comprises reacting 4'-dihydroxydiphenyl sulfone and a basic substance in water or an organic solvent containing water. [Chemical 2] [In the formula (2), X represents a chlorine atom or a bromine atom. ] 3. A thermosensitive recording material comprising a support and a recording layer containing a basic dye, a color developer, a sensitizer and the like, which is a sulfonyl group represented by the general formula (1) as a color developer. A heat-sensitive recording material containing a compound.