JP2606635B2 - Novel phenolic compound and thermal recording sheet using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel phenolic compound and a heat-sensitive recording sheet using the phenolic compound as a developer.

[0002]

2. Description of the Related Art Generally, a heat-sensitive recording sheet is prepared by grinding and dispersing a colorless or light-colored basic colorless dye and an organic developer such as a phenolic compound into fine particles, and then mixing and mixing the two. A coating solution obtained by adding an agent, a sensitivity enhancer, a lubricant and other auxiliaries is coated on a support such as paper, synthetic paper, film, plastic, etc.
A color record is obtained by an instantaneous chemical reaction caused by heating with a hot stamp, a laser beam or the like.

[0003] These thermosensitive recording sheets have been applied to a wide range of fields such as measuring recorders, computer terminal printers, facsimile machines, automatic ticket vending machines, and bar code labels. Accordingly, the required quality of the heat-sensitive recording sheet has become higher. For example, with the speeding up of recording, it is required that a sharp color image can be obtained at a high density even with a small amount of thermal energy, and on the other hand, a thermosensitive recording excellent in storage stability such as light resistance, weather resistance, oil resistance and water resistance. A sheet is required.

[0004] In order to meet these demands, a technique of using various 4-hydroxydiphenylsulfone derivatives as a color developer has already been disclosed (JP-A-57-210).
886, JP-A-58-82788, JP-A-58-20493, JP-A-58-132593, JP-A-60-13852, JP-A-62-1
19095).

[0005]

On the other hand, as heat-sensitive recording paper has recently become widespread, there have been many occasions of using a felt pen made of oil-based ink after heat-sensitive recording. However,
Since oil-based inks contain various organic solvents,
For example, when an oil-based red ink is used to write on a black coloring thermosensitive recording paper using the above 4-hydroxydiphenylsulfone derivative as a color developer, the original black coloring of the thermosensitive recording paper, which is a color developed by the solvent, is obtained. And the red color of the red ink are mixed, so that pure red writing cannot be obtained. The same applies to other colors as well as red.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel phenolic compound, and to use the phenol compound as a color developer to write a vivid color using a felt pen of an oily ink of any color. The object of the present invention is to provide a high-sensitivity heat-sensitive recording sheet capable of performing the following.

[0007]

The phenolic compound according to the present invention is represented by the following general formula (I ) .

[0008]

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[0009] _{[wherein, R 1, R 2, R} 3 and R ₄ are hydrogen atom; a methyl group, an ethyl group, a propyl group, isopropyl
Phenyl group; an alkyl group selected from the Le-substituted phenyl group (the substituent is a methyl group, a methoxy group, halogen atom
Child, an amino group or a nitro group); or C5 -C6
And may be the same group, at least one of which is a group other than a hydrogen atom . Also, R
Is methyl, ethyl, propyl, isopropyl
An alkyl group selected from a group, a butyl group, an isobutyl group and a pentyl group ; a vinyl group; a phenyl group ;
(A substituent is a methyl group, a methoxy group, a halogen atom or
Is a nitro group); cyclohexyl group;
Xyl group (substituents are methyl group, methoxy group, halogen
Atom or a nitro group); benzyl; or substituted Baie
Benzyl group (substituents are methyl group, methoxy group, halogen
Atom or nitro group) . ]

[0010]

[0011]

[0012]

[0013]

[0014]

The phenolic compound can be obtained, for example, by using a p-alkoxybenzenesulfonyl chloride derivative and an acetoxybenzene derivative as raw materials by the following reaction.

[0016]

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The phenolic compound can also be obtained, for example, by sulfonating a phenol derivative, synthesizing a 4,4'-dihydroxydiphenyl sulfone derivative, and then monoetherifying the derivative.

[0018]

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[0019] (wherein, R _1, R _2, R _3, R ₄ and R of the above with same) Further, the thus compound represented the general formula (I), heat-sensitive coloring layer as the organic color developer Can be contained.

Hereinafter, specific examples of the phenolic compound represented by the general formula (I) of the present invention will be described, but the invention is not necessarily limited thereto.

(1) 4-hydroxy-3-methyl-3 '
-Methyl-4'-methoxydiphenylsulfone (2) 4-hydroxy-3-methyl-4'-methoxydiphenylsulfone (3) 4-hydroxy-3'-methyl-4'-methoxydiphenylsulfone (4) 4-hydroxy -2-methyl-2'-methyl-
4'-methoxydiphenylsulfone (5) 4-hydroxy-2-methyl-4'-methoxydiphenylsulfone (6) 4-hydroxy-2'-methyl-4'-methoxydiphenylsulfone (7) 4-hydroxy-3- Methyl-2'-methyl-
4'-methoxydiphenylsulfone (8) 4-hydroxy-2-methyl-3'-methyl-
4'-methoxydiphenylsulfone (9) 4-hydroxy-3-methyl-3'-methyl-
4'-methoxydiphenylsulfone (10) 4-hydroxy-3-methyl-4'-ethoxydiphenylsulfone (11) 4-hydroxy-3'-methyl-4'-ethoxydiphenylsulfone (12) 4-hydroxy-2- Methyl-2'-methyl-
4'-ethoxydiphenyl sulfone (13) 4-hydroxy-2-methyl-4'-ethoxydiphenyl sulfone (14) 4-hydroxy-2'-methyl-4'-ethoxydiphenyl sulfone (15) 4-hydroxy-3- Methyl-2'-methyl-
4'-ethoxydiphenylsulfone (16) 4-hydroxy-2-methyl-3'-methyl-
4'-ethoxydiphenylsulfone (17) 4-hydroxy-3-methyl-3'-methyl-
4'-propoxydiphenyl sulfone (18) 4-hydroxy-3-methyl-4'-propoxydiphenyl sulfone (19) 4-hydroxy-3'-methyl-4'-propoxydiphenyl sulfone (20) 4-hydroxy-2- Methyl-2'-methyl-
4'-propoxydiphenyl sulfone (21) 4-hydroxy-2-methyl-4'-propoxydiphenyl sulfone (22) 4-hydroxy-2'-methyl-4'-propoxydiphenyl sulfone (23) 4-hydroxy-3- Methyl-2'-methyl-
4'-propoxydiphenyl sulfone (24) 4-hydroxy-2-methyl-3'-methyl-
4'-propoxydiphenyl sulfone (25) 4-hydroxy-3-methyl-3'-methyl-
4'-propoxydiphenyl sulfone (26) 4-hydroxy-3-methyl-4'-benzyloxydiphenyl sulfone (27) 4-hydroxy-3'-methyl-4'-benzyloxydiphenyl sulfone (28) 4-hydroxy- 2-methyl-2'-methyl-
4'-benzyloxydiphenylsulfone (29) 4-hydroxy-2-methyl-4'-benzyloxydiphenylsulfone (30) 4-hydroxy-2'-methyl-4'-benzyloxydiphenylsulfone (31) 4-hydroxy -3-methyl-2'-methyl-
4'-benzyloxydiphenyl sulfone (32) 4-hydroxy-2-methyl-3'-methyl-
4'-benzyloxydiphenylsulfone (33) 4-hydroxy-3-phenyl-4'-vinyloxydiphenylsulfone (34) 4-hydroxy-2'-phenyl-4'-phenoxydiphenylsulfone (35) 4-hydroxy- 3-phenyl-2'-phenyl-4'-p-methylphenoxydiphenylsulfone (36) 4-hydroxy-3-phenyl-3'-phenyl-4'-cyclohexyloxydiphenylsulfone (37) 4-hydroxy-3- Phenyl-4 '-(4-
Methylcyclohexyloxy) diphenyl sulfone (38) 4-hydroxy-2,5-diphenyl-4'-
Benzyloxydiphenylsulfone (39) 4-hydroxy-2 ', 5'-diphenyl-
4'-p-methylbenzyloxydiphenyl sulfone (40) 4-hydroxy-2,5-diphenyl-2'-
Phenyl-4'-butoxydiphenylsulfone (41) 4-hydroxy-3-p-tolyl-4'-vinyloxydiphenylsulfone (42) 4-hydroxy-2'-p-methoxyphenyl-4'-phenoxydiphenylsulfone ( 43) 4-Hydroxy-3-p-chlorophenyl-
2'-phenyl-4'-p-methoxyphenoxydiphenylsulfone (44) 4-hydroxy-3-p-nitrophenyl-
3'-phenyl-4'-cyclohexyloxydiphenylsulfone (45) 4-hydroxy-3-p-aminophenyl-
4 '-(4-methoxycyclohexyloxy) diphenyl sulfone (46) 4-hydroxy-2-m-nitrophenyl-5
-O-chlorophenyl-4'-benzyloxydiphenylsulfone (47) 4-hydroxy-2'-o-chlorophenyl-
5'-p-methoxyphenyl-4'-p-methoxybenzyloxydiphenylsulfone (48) 4-hydroxy-2,5-di-p-tolyl-
2'-p-tolyl-4'-butoxydiphenylsulfone (49) 4-hydroxy-3-cyclohexyl-4'-
Vinyloxydiphenyl sulfone (50) 4-hydroxy-2'-cyclohexyl-4 '
-Phenoxydiphenylsulfone (51) 4-hydroxy-3-cyclohexyl-2'-
Cyclohexyl-4'-p-chlorophenoxydiphenylsulfone (52) 4-hydroxy-3-cyclohexyl-3'-
Cyclohexyl-4'-cyclohexyloxydiphenyl sulfone (53) 4-hydroxy-3-cyclohexyl-4'-
(4-chlorocyclohexyloxy) diphenyl sulfone (54) 4-hydroxy-2,5-dicyclohexyl-
4'-benzyloxydiphenylsulfone (55) 4-hydroxy-2 ', 5'-dicyclohexyl-4'-p-chlorobenzyloxydiphenylsulfone (56) 4-hydroxy-2,5-dicyclohexyl-
2'-cyclohexyl-4'-butoxydiphenylsulfone (57) 4-hydroxy-3-cyclopentyl-4'-
Vinyloxydiphenyl sulfone (58) 4-hydroxy-2'-cyclopentyl-4 '
-Phenoxydiphenylsulfone (59) 4-hydroxy-3-cyclopentyl-2'-
Cyclopentyl-4'-p-nitrophenoxydiphenylsulfone (60) 4-hydroxy-3-cyclopentyl-3'-
Cyclopentyl-4'-cyclohexyloxydiphenyl sulfone (61) 4-hydroxy-3-cyclopentyl-4'-
(4-Nitrocyclohexyloxy) diphenyl sulfone (62) 4-hydroxy-2,5-dicyclopentyl-
4'-benzyloxydiphenylsulfone (63) 4-hydroxy-2 ', 5'-dicyclopentyl-4'-p-nitrobenzyloxydiphenylsulfone (64) 4-hydroxy-2,5-dicyclopentyl-
2'-cyclopentyl-4'-butoxydiphenylsulfone (65) 4-hydroxy-3-ethyl-4'-vinyloxydiphenylsulfone (66) 4-hydroxy-2'-ethyl-4'-phenoxydiphenylsulfone (67) 4-hydroxy-3-ethyl-2'-ethyl-
4'-p-methylphenoxydiphenyl sulfone (68) 4-hydroxy-3-ethyl-3'-ethyl-
4'-cyclohexyloxydiphenyl sulfone (69) 4-hydroxy-3-ethyl-4 '-(4-methylcyclohexyloxy) diphenyl sulfone (70) 4-hydroxy-2,5-diethyl-4'-benzyloxydiphenyl sulfone (71) 4-hydroxy-2 ', 5'-diethyl-4'
-P-methylbenzyloxydiphenylsulfone (72) 4-hydroxy-2,5-diethyl-2'-ethyl-4'-butoxydiphenylsulfone (73) 4-hydroxy-3-propyl-4'-vinyloxydiphenylsulfone (74) 4-hydroxy-2'-propyl-4'-phenoxydiphenylsulfone (75) 4-hydroxy-3-propyl-2'-propyl-4'-p-methoxyphenoxydiphenylsulfone (76) 4-hydroxy- 3-propyl-3'-propyl-4'-cyclohexyloxydiphenylsulfone (77) 4-hydroxy-3-propyl-4 '-(4-
(Methoxycyclohexyloxy) diphenyl sulfone (78) 4-hydroxy-2,5-dipropyl-4'-
Benzyloxydiphenyl sulfone (79) 4-hydroxy-2 ', 5'-dipropyl-
4 '-(4-methoxybenzyloxy) diphenylsulfone (80) 4-hydroxy-2,5-dipropyl-2'-
Propyl-4'-butoxydiphenylsulfone (81) 4-hydroxy-3-ethyl-4'-methoxydiphenylsulfone (82) 4-hydroxy-2'-ethyl-4'-methoxydiphenylsulfone (83) 4-hydroxy- 3-ethyl-2'-ethyl-
4'-methoxydiphenylsulfone (84) 4-hydroxy-3-ethyl-3'-ethyl-
4'-Methoxydiphenyl sulfone (85) 4-hydroxy-3-ethyl-4'-methoxydiphenyl sulfone (86) 4-hydroxy-2,5-diethyl-4'-ethoxydiphenyl sulfone (87) 4-hydroxy-2 ', 5'-diethyl-4'
-Ethoxydiphenylsulfone (88) 4-hydroxy-2,5-diethyl-2'-ethyl-4'-ethoxydiphenylsulfone (89) 4-hydroxy-3-propyl-4'-propoxydiphenylsulfone (90) 4- Hydroxy-2'-propyl-4'-propoxydiphenylsulfone (91) 4-hydroxy-3-propyl-2'-propyl-4'-propoxydiphenylsulfone (92) 4-hydroxy-3-propyl-3'-propyl -4'-propoxydiphenylsulfone (93) 4-hydroxy-3-propyl-4'-butoxydiphenylsulfone (94) 4-hydroxy-2,5-dipropyl-4'-
Butoxydiphenyl sulfone (95) 4-hydroxy-2 ', 5'-dipropyl-
4'-butoxydiphenyl sulfone (96) 4-hydroxy-2,5-dipropyl-2'-
Propyl-4'-butoxydiphenylsulfone (97) 4-hydroxy-3-methyl-4'-propoxydiphenylsulfone (98) 4-hydroxy-3-methyl-3'-methyl-
4'-propoxydiphenyl sulfone (99) 4-hydroxy-3-methyl-3'-methyl-
4'-pentyloxydiphenylsulfone (100) 4-hydroxy-3-methyl-3'-methyl-4'-cyclohexyloxydiphenylsulfone (101) 4-hydroxy-3-methyl-3'-methyl-4'-benzyl Oxydiphenylsulfone (102) 4-hydroxy-3-methyl-3'-methyl-4'-m-methylbenzyloxydiphenylsulfone (103) 4-hydroxy-3-methyl-3'-methyl-4'-butoxydiphenyl Sulfone (104) 4-hydroxy-3-methyl-3'-methyl-4'-isopropoxydiphenylsulfone (105) 4-hydroxy-3-methyl-3'-methyl-4'-isobutoxydiphenylsulfone (106) 4-hydroxy-3-ethyl-4'-ethoxydiphenylsulfone (10 7) 4-hydroxy-3-ethyl-4'-propoxydiphenylsulfone (108) 4-hydroxy-3-isopropylpropyl-4'-
Ethoxydiphenyl sulfone (109) 4-hydroxy-3-isopropylpropyl-4'-
Propoxydiphenyl sulfone (110) 4-hydroxy-3-cyclohexyl-4 '
-Ethoxydiphenyl sulfone

When forming a heat-sensitive recording sheet in the present invention, 1,2-di (3-methylphenoxy) ethane, di (p-methylbenzyl) oxalate, p-
Benzylbiphenyl, β-benzyloxynaphthalene,
By using 4-biphenyl-p-tolyl ether, m-terphenyl, 1,2-diphenoxyethane, dibenzyl oxalate, and di (p-chlorobenzyl) oxalate, the stability to oil-based inks is further improved. Can be done.

The basic colorless dye used in the heat-sensitive recording sheet of the present invention is not particularly limited, but triphenylmethane-based, fluoran-based, and fluorene-based dyes are preferred. Specific examples thereof are shown below.

Triphenylmethane leuco dye 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide [also known as crystal violet lactone].

Fluoran Leuco Dye 3-Diethylamino-6-methyl-7-anilinofluoran 3- (N-ethyl-p-toluidino) -6-methyl-
7-anilinofluoran 3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluoran 3-diethylamino-6-methyl-7- (o, p-dimethylanilino) fluoran 3 -Pyrrolidino-6-methyl-7-anilinofluoran 3-piperidino-6-methyl-7-anilinofluoran 3- (N-cyclohexyl-N-methylamino) -6
Methyl-7-anilinofluoran 3-diethylamino-7- (m-trifluoromethylanilino) fluoran 3-Nn-dibutylamino-6-methyl-7-anilinofluoran 3-Nn-dibutyl Amino-7- (o-chloroanilino) fluoran 3- (N-ethyl-N-tetrahydrofurfurylamino) -6-methyl-7-anilinofluoran 3-dibutylamino-6-methyl-7- (o, p -Dimethylanilino) fluoran 3- (N-methyl-N-propylamino) -6-methyl-7-anilinofluoran 3-dibutylamino-7- (o-chloroanilino) fluoran 3-diethylamino-7- (o -Chloroanilino) fluoran 3-diethylamino-6-methyl-chlorofluoran 3-diethylamino-6-methyl-fluora 3-cyclohexylamino-6-chlorofluorane 3-diethylamino-benzo [a] -fluoran 3-n-dipentylamino-6-methyl-7-anilinofluoran 2- (4-oxa-hexyl) -3- Dimethylamino-
6-methyl-7-anilinofluoran 2- (4-oxa-hexyl) -3-diethylamino-
6-methyl-7-anilinofluoran 2- (4-oxa-hexyl) -3-dipropylamino-6-methyl-7-anilinofluoran

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

These dyes can be used alone or in combination of two or more.

In the present invention, as an image stabilizer, 4,4'-butylidene (6-tert-butyl-3-methylphenol) 2,2'-di-tert-butyl-5,5'-dimethyl-4,
4'-sulfonyldiphenol 1,1,3-tris (2-methyl-4-hydroxy-5
-Cyclohexylphenyl) butane 1,1,3-tris (2-methyl-4-hydroxy-5
(T-butylphenyl) butane and the like can also be added.

As the binder used in the present invention, completely silicified polyvinyl alcohol having a polymerization degree of 200 to 1900, partially saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, butyral-modified polyvinyl alcohol Alcohol, other modified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, styrene-maleic anhydride copolymer, styrene-butadiene copolymer and ethyl cellulose, cellulose derivatives such as acetyl cellulose, polyvinyl chloride, polyvinyl acetate,
Examples include polyacrylamide, polyacrylate, polyacrylamide, polyacrylate, polyvinyl butyral, polystyrene and copolymers thereof, polyamide resin, silicone resin, petroleum resin, terpene resin, ketone resin, and cumarone resin. it can. These polymer substances are used by dissolving them in solvents such as water, alcohols, ketones, esters, and hydrocarbons.Also, they are used in the form of emulsified or dispersed in water or other media in the form of a paste. They can be used together.

The filler used in the present invention includes silica,
Examples include inorganic or organic fillers such as calcium carbonate, kaolin, calcined kaolin, diatomaceous earth, talc, titanium oxide, and aluminum hydroxide.

In addition, a releasing agent such as a fatty acid metal salt, a lubricant such as a wax, a benzophenone-based or triazole-based ultraviolet absorber, a water-proofing agent such as glyoxal, a dispersant, an antifoaming agent and the like can be used. it can.

The amounts of the organic developer and the basic colorless dye used in the heat-sensitive recording sheet 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. However, usually, 1 part of the organic color developer and 1 part of the filler,
0 parts are used, and a suitable amount of the binder is 10 to 25% of the total solid content.

The desired heat-sensitive recording sheet can be obtained by applying a coating solution having the above composition to any support such as paper, synthetic paper, film, plastic and the like.

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.

The above-mentioned organic color developer, basic colorless dye, and optionally added materials are finely divided by a pulverizer such as a ball mill, an attritor, a sand grinder or an appropriate emulsifying device until the particle diameter becomes several microns or less. And a binder and various kinds of additive materials are added according to the purpose to obtain a coating liquid.

Further, 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 color-forming sensitivity.

[0037]

When the novel phenolic compound according to the present invention is used as a developer for a heat-sensitive recording sheet, the reason why the discoloration does not occur even when writing with an oil-based ink is considered as follows. Generally, when writing is performed on a thermosensitive recording sheet with a felt pen made of an oil-based ink, the developer, leuco dye and sensitizer in the thermosensitive coloring layer are dissolved in the organic solvent contained in the ink. Then, as the solvent evaporates, a color forming composition in which the developer, the leuco dye and the sensitizer are integrated is formed in the writing portion. Therefore, for example, when a red ink is used, the red color and the color developed on the heat-sensitive recording sheet are mixed, resulting in a dull written image.

The heat-sensitive recording sheet of the present invention uses a 4-hydroxydiphenylsulfone derivative having a specific substituent on two benzene nuclei adjacent to a sulfone group as a developer, or further uses a specific sensitizer in combination. . Therefore, the solubility of these materials in a solvent is extremely low, and almost no color-forming composition is formed even by evaporation of the solvent, so that it is considered that discoloration by the oil-based ink does not occur.

Further, in the present invention, the melt dissolution and diffusion rate and the saturation solubility of the color developer with respect to the sensitizer used are extremely high, and the melt dissolution and diffusion rate and the saturation solubility of the dye are also large. For this reason, when an organic color developer, a sensitizer, and a leuco dye cause a physicochemical reaction by heating, a color-forming composition is quickly formed, and a high-density color-formed image can be obtained.

[0040]

The present invention will be described below with reference to examples.
In addition, in description, a part shows a weight part.

(Synthesis Example 1) 4-hydroxy-3-methyl-4'-ethoxydiphenyl
Synthesis of Rusulfone This compound was synthesized from ethoxybenzene by a three-step synthesis method described below.

(1) Synthesis of p-ethoxybenzenesulfonyl chloride 100 g of ethoxybenzene was added to 600 ml of chloroform, and 191 g of chlorosulfonic acid was added dropwise at 5 ° C. or less under ice cooling. After the dropwise addition, the mixture was returned to room temperature and stirred for 1 hour to complete the reaction. The reaction solution was poured into ice water, and the organic layer was separated. Thereafter, the solvent was distilled off, and the residue was purified with a silica gel column (eluent composition n-
Hexane / ethyl acetate = 10/1) to obtain 110.9 g of p-ethoxybenzenesulfonyl chloride.

(2) 3-methyl-4-acetoxy-4 '
Synthesis of ethoxydiphenylsulfone To 300 ml of 1,2-dichloroethane was added 68.3 g of orthotolyl acetate, and then 18.0 g of ferric chloride was added. To this solution, 110.3 g of the product of the above (1) dissolved in 200 ml of 1,2-dichloroethane was added dropwise, and after the addition, the mixture was stirred for 4 days to complete the reaction. Pour the reaction solution into water,
After extraction with chloroform and washing with water, the solvent was distilled off, and the residue was purified by a silica gel column (eluent composition: n-hexane / ethyl acetate = 3/1) to give 3-methyl-4-acetoxy-
7.1 g of 4'-ethoxydiphenylsulfone was obtained.

(3) 4-hydroxy-3-methyl-4 '
-Synthesis of ethoxydiphenyl sulfone 7.1 g of the above product (2) was dissolved in 70 ml of ethanol, 0.9 g of sodium hydroxide dissolved in 10 ml of water was added, and the mixture was stirred for 3 hours to complete the reaction. The reaction solution was poured into water, extracted with ethyl acetate, washed with water, and the solvent was distilled off. The residue was purified by a silica gel column (eluent composition: n-hexane / ethyl acetate = 7/3), and the desired 4-hydroxy-3
2.4 g of -methyl-4'-ethoxydiphenyl sulfone (white crystals, melting point: 158 to 159 ° C) were obtained.

(Synthesis Example 2) 4-hydroxy-3'-methyl-4'-ethoxydife
Synthesis of Nyl Sulfone This compound was synthesized from 2-ethoxytoluene as a raw material by the following three-step synthesis method.

(1) Synthesis of 3-methyl-4-ethoxybenzenesulfonyl chloride 2-ethoxytoluene in 230 ml of chloroform
3 under ice cooling at 0 ° C. or less.
g was added dropwise. After the addition, the mixture was returned to room temperature and stirred overnight to complete the reaction. The reaction solution was poured into ice water, and the organic layer was separated. The reaction solution was poured into ice water, the organic layer was separated, and the solvent was distilled off.
Methyl-4-ethoxybenzenesulfonyl chloride 3
1.5 g were obtained.

(2) 4-tosyloxy-3'-methyl-
Synthesis of 4'-ethoxydiphenyl sulfone In 50 ml of 1,2-dichloroethane, 5.8 g of phenol tosylate was added, and then 4.3 g of ferric chloride was added.
5 g of the above product (1) dissolved in 50 ml of 1,2-dichloroethane was added dropwise at 10 ° C., and the mixture was stirred overnight at room temperature to complete the reaction. The reaction solution was poured into the reaction solution, extracted with chloroform, washed with water, and the solvent was distilled off. The residue was purified by a silica gel column (eluent composition: n-hexane / ethyl acetate = 3/1).
Thus, 1.1 g of 4-tosyloxy-3'-methyl-4'-ethoxydiphenylsulfone was obtained.

(3) 4-hydroxy-3'-methyl-
Synthesis of 4'-ethoxydiphenyl sulfone 1.1 g of the above product (2) was dissolved in 10 ml of ethanol, 0.17 g of potassium hydroxide dissolved in 5 ml of water was added, and the solution was stirred at 50 ° C. for 2 hours. The reaction was completed. The reaction solution was poured into water, extracted with ethyl acetate, washed with water, and the solvent was distilled off. 0.7 g of the residue was crystallized from n-hexane to give the desired 4-hydroxy-3'-methyl-4'-ethoxy. Diphenyl sulfone (white crystals, melting point: 158 to 15)
(9 ° C.) 0.1 g was obtained.

(Synthesis Example 3) 4-hydroxy-3-methyl-3'-methyl-4'-prop
Synthesis of ropoxydiphenyl sulfone This compound was synthesized from 2-propoxytoluene as a raw material by the following three-step synthesis method.

(1) Synthesis of 3-methyl-4-propoxybenzenesulfonyl chloride In the same manner as in Synthesis Example 1, except that ethoxybenzene in Synthesis Example 1 (1) was changed to 2-propoxytoluene. 4-Propoxybenzenesulfonyl chloride was synthesized.

(2) 3-methyl-4-acetoxy-3 '
Synthesis of -methyl-4'-propoxydiphenylsulfone 3-Synthesis was performed in the same manner as in Synthesis Example 1 except that p-ethoxybenzenesulfonyl chloride in (2) of Synthesis Example 1 was changed to 3-methyl-4-propoxybenzenesulfonyl chloride. Methyl-4-acetoxy-3'-methyl-
4'-propoxydiphenyl sulfone was synthesized.

(3) 4-hydroxy-3-methyl-3 '
Synthesis of -methyl-4'-propoxydiphenylsulfone 3-methyl-4-acetoxy-4'-ethoxydiphenylsulfone in (3) of Synthesis Example 1 was replaced with 3-methyl-4-acetoxy-3'-methyl-4 '
-Hydroxy-3-methyl-3'-methyl-4'-propoxydiphenylsulfone (white crystals,
137 ° C).

(Synthesis Example 4) 4-hydroxy-3-methyl-3'-methyl-4-methoate
Synthesis of xidiphenylsulfone The present compound was synthesized from 2-methoxytoluene as a raw material by the following three-step synthesis method.

(1) Synthesis of 3-methyl-4-methoxybenzenesulfonyl chloride In the same manner as in Synthesis Example 1 except that ethoxybenzene in Synthesis Example 1 (1) was changed to 2-methoxytoluene.
3-Methyl-4-methoxybenzenesulfonyl chloride was synthesized.

(2) 3-methyl-4-acetoxy-3 '
Synthesis of -methyl-4'-methoxydiphenyl sulfone 3-Synthesis was performed in the same manner as in Synthesis Example 1 except that p-ethoxybenzenesulfonyl chloride in (2) of Synthesis Example 1 was changed to 3-methyl-4-methoxybenzenesulfonyl chloride. Methyl-4-acetoxy-3'-methyl-4 '
-Methoxydiphenyl sulfone was synthesized.

(3) 4-hydroxy-3-methyl-3 '
Synthesis of -methyl-4'-methoxydiphenylsulfone 3-methyl-4-acetoxy-4'-ethoxydiphenylsulfone in (3) of Synthesis Example 1 was converted to 3-methyl-4.
-Hydroxy-3-methyl-3'-methyl-4'-methoxydiphenylsulfone (white crystals, melting point 184) in the same manner as in Synthesis Example 1 except that -acetoxy-3'-methyl-4'-methoxydiphenylsulfone was used. ~ 185 ° C)
Was synthesized.

(Synthesis Example 5) 4-hydroxy-3-methyl-4'-n-propoxydi
Synthesis of phenylsulfone This compound was obtained by using 3.7 g of propoxybenzene as a starting material in a three-step reaction in the same manner as in Synthesis Example 1.
-Hydroxy-3-methyl-4'-n-propoxydiphenyl sulfone was obtained. Melting point 136.5-139.0
° C.

(Synthesis Example 6) This compound is synthesized by synthesizing 3,3'-dimethyl-4,4'-dihydroxydiphenylsulfone from o-cresol according to a known method and then monoetherifying the compound. did. 4-hydroxy-3-methyl-3'-methyl-4'-i
Synthesis of Sopropoxydiphenylsulfone 27.8 g of 3,3'-dimethyl-4,4'-dihydroxydiphenylsulfone and 4.0 g of sodium hydroxide were added to D
After dissolving in MSO, 12.3 g of isopropyl bromide
Was added and reacted at room temperature for 6 hours. After the completion of the reaction, toluene and water were added to this solution, followed by heating and stirring. After separating the aqueous layer, the toluene layer was washed with water several times, and further washed with aqueous sodium bicarbonate. After the toluene layer was neutralized with dilute hydrochloric acid and cooled, crystals precipitated. The crystals were separated by filtration and further recrystallized with toluene to obtain 23.5 g of crystals. 183.0-184.0 ° C.

Synthesis Example 7 4-Hydroxy-3-methyl-3'-methyl-4'-bu
Synthesis of toxicdiphenyl sulfone 12.3 g of isopropyl bromide was added to butyl bromide 1
In the same manner as in Synthesis Example 6 except that 3.7 g was used, 25.4 g of 4-hydroxy-3-methyl-3'-methyl-4'-butoxydiphenylsulfone was obtained. Melting point 152.5-
155.0 ° C.

Synthesis Example 8 4-Hydroxy-3-methyl-3'-methyl-4'-pe
Synthesis of pentyloxydiphenyl sulfone 12.3 g of isopropyl bromide was added to pentyl bromide 1
25.1 g of 4-hydroxy-4-methyl-3'-methyl-4'-pentyloxydiphenylsulfone was obtained in the same manner as in Synthesis Example 6 except that the amount was changed to 5.1 g. Melting point 95.
5-100.0 ° C.

Synthesis Example 9 4-Hydroxy-3-methyl-3'-methyl-4'-cy
Synthesis of clohexyloxydiphenyl sulfone The same method as in Synthesis Example 6 was used except that 12.3 g of isopropyl bromide was replaced with 16.3 g of cyclohexyl bromide.
13.3 g of -hydroxy-4-methyl-3'-methyl-4'-cyclohexyloxydiphenylsulfone were obtained. 143.0-149.0 ° C.

(Synthesis Example 10) 4-Hydroxy-3-methyl-3'-methyl-4'-be
Synthesis of benzyloxydiphenylsulfone 4-hydroxy-3-methyl-3'-methyl-4'-benzyloxydiphenylsulfone 29 in the same manner as in Synthesis Example 6 except that 12.3 g of isopropyl bromide was replaced by 12.6 g of benzyl chloride. .1 g were obtained. Melting point 14
5.5-147.0 ° C.

(Synthesis Example 11) 4-hydroxy-3-methyl-3'-methyl-4'-m
Synthesis of -methyl-benzyloxydiphenyl sulfone 4-Hydroxy-3-methyl-3'-methyl-4 'in the same manner as in Synthesis Example 6 except that 12.3 g of isopropyl bromide was replaced with 14.1 g of m-methylbenzyl chloride.
-M-methylbenzyloxydiphenyl sulfone
9.7 g were obtained. 141.5-144.0 ° C.

Table 1 shows typical examples of the compounds according to the present invention produced in the same manner.

[0065]

[Table 1]

[0066]

[Table 2]

An example of producing a thermosensitive recording sheet using the phenolic compound of the present invention will be described below.

Examples 1 to 6 Liquid A (color developer dispersion) Color developer (see Table 2) 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts Liquid B (dye dispersion) Liquid) 3-N-n-dibutylamino-6-methyl-7-anilinofluoran 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts Water 2.6 parts Each liquid of the above composition is sand-grindered. Milled to an average particle size of 1 micron. Subsequently, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. Liquid A 36.0 parts Liquid B 9.2 parts Kaolin clay (50% dispersion) 12.0 parts Each of the above coating liquids is coated on one side of a 50 g / m ² base paper 6.0.
g / m ² and dried, and this sheet was treated with a super calender so that the smoothness became 500 to 600 seconds to prepare a heat-sensitive recording sheet.

[Comparative Examples 1-4] Liquid E (color developer dispersion) Color developer (see Table 2) 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts Liquid B (dye dispersion) Liquid) 3-N-n-dibutylamino-6-methyl-7-anilinofluoran 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts Water 2.6 parts Each liquid of the above composition is sand-grindered. Milled to an average particle size of 1 micron. Subsequently, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. Liquid E 36.0 parts Liquid B 9.2 parts Kaolin clay (50% dispersion) 12.0 parts A heat-sensitive recording sheet was prepared in the same manner as in Example 1.

[Examples 7 to 18] Liquid A (color developer dispersion) Color developer (see Table 2) 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts Liquid B (dye dispersion) Liquid) 3-Nn-dibutylamino-6-methyl-7-anilinofluoran 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts Water 2.6 parts Liquid C (sensitizer dispersion) Sensitization Agent (see Table 2) 4.0 parts 10% aqueous solution of polyvinyl alcohol 5.0 parts Water 3.0 parts Each liquid of the above composition was ground to an average particle diameter of 1 micron with a sand grinder. Subsequently, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. Liquid A 36.0 parts Liquid B 9.2 parts Liquid C 12.0 parts Kaolin clay (50% dispersion) 12.0 parts A thermosensitive recording sheet was prepared in the same manner as in Example 1.

[Examples 19 to 45] Liquid C (color developer dispersion) Color developer (see Table 3) 6.0 parts 10% aqueous solution of polyvinyl alcohol 18.8 parts Water 11.2 parts Liquid B (dye dispersion) Liquid) 3-N-n-dibutylamino-6-methyl-7-anilinofluoran 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts Water 2.6 parts Each liquid of the above composition is sand-grindered. Milled to an average particle size of 1 micron. Subsequently, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. Liquid C 36.0 parts Liquid B 9.2 parts Kaolin clay (50% dispersion) 12.0 parts Each of the above coating liquids is applied to one side of a 50 g / m ² base paper 6.0.
g / m ² and dried, and this sheet was treated with a super calender so that the smoothness became 500 to 600 seconds to prepare a heat-sensitive recording sheet.

[Examples 46 to 72] Liquid C (color developer dispersion) Color developer (see Table 4) 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts Liquid B (dye dispersion) Liquid) 3-Nn-dibutylamino-6-methyl-7-anilinofluoran 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts Water 2.6 parts Liquid D (sensitizer dispersion) Sensitization Agent (see Table 4) 4.0 parts 10% aqueous solution of polyvinyl alcohol 5.0 parts Water 3.0 parts Each liquid of the above composition was subjected to an average particle diameter of 1 with a sand glider.
Milled to a micron. Subsequently, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. Liquid C 36.0 parts Liquid B 9.2 parts Liquid D 12.0 parts Kaolin clay (50% dispersion) 12.0 parts A heat-sensitive recording sheet was prepared in the same manner as in Example 1.

Tables 2, 3 and 4 collectively show the results of quality tests performed on the heat-sensitive recording papers obtained in the above Examples and Comparative Examples.

[0074]

[Table 3]

[0075]

[Table 4]

[0076]

[Table 5]

[0077]

[Table 6]

[0078]

[Table 7]

[0079]

[Table 8]

[0080]

[Table 9]

[0081]

[Table 10]

[0082]

[Table 11]

[0083]

[Table 12]

[0084]

[Table 13]

Note 1) Static color density: A color obtained by pressing a hot plate heated to 105 ° C. at a pressure of 10 g / cm ² for 5 seconds and developing the color with a Macbeth densitometer (RD-914, using an amber filter; the same applies hereinafter). Measurement.

Note 2) Dynamic color density: Image density recorded with a thermal facsimile UF-1000 manufactured by Matsushita Electric Transmission Co., Ltd. with an applied energy of 0.58 mj / Dot and a pulse width of 0.97 ms was measured with a Macbeth densitometer. .

Note 3) Discoloration due to oil-based ink: Using an oil-based red magic ink No. 500 manufactured by Teranishi Kagaku, writing was performed on a thermal paper sample, and the degree of discoloration with respect to the original red color was visually measured. ◎: No discoloration ○: Almost no discoloration △: Slight discoloration ×: Significant discoloration

[0088]

Advantages of the present invention include the following. (1) Since the heat-sensitive recording sheet using the phenolic compound according to the present invention as a developer does not cause discoloration when writing with an oil-based ink felt-tip pen, the heat-sensitive recording sheet can be freely formed using these writing tools. It became possible to write freely. (2) It is excellent in thermal responsiveness, and high density color recording can be obtained. (3) When the specified sensitizer is used in combination, the effect described in (1) becomes more remarkable.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Umeda 5-21-1, Oji, Kita-ku, Tokyo Jujo Paper Co., Ltd. Central Research Laboratory (72) Inventor Ryoichi Kinishi 345 Naoe Yoshitomicho, Chikugami-gun, Fukuoka Prefecture (72) Inventor Akira Shimada Nakatsu City, Oita Prefecture

Claims (3)

(57) [Claims] [Claim 1] The following general formula: [ Wherein R ₁ , R ₂ , R ₃ and R ₄ are a hydrogen atom;
Selected from the group consisting of methyl, ethyl, propyl and isopropyl
Phenyl group; alkyl groups substituted phenyl group (the substituent
Represents a methyl group, a methoxy group, a halogen atom, an amino group, etc.
Or a nitro group); or a C5 -C6 cycloalkyl group, which may be the same group, but at least one of which is a group other than a hydrogen atom . R is a methyl group,
Ethyl, propyl, isopropyl, butyl, i
An alkyl group selected from a sobutyl group and a pentyl group ;
Le group; a phenyl group; a substituted phenyl group (the substituent is methyl
Group, methoxy group, halogen atom or nitro group.
Cyclohexyl group; substituted cyclohexyl group (substituted
The group is a methyl group, a methoxy group, a halogen atom or a nitro group.
A benzyl group; or a substituted benzyl group (substituted
The group is a methyl group, a methoxy group, a halogen atom or a nitro group.
A) . ] The novel phenolic compound represented by these. 2. A colorless or pale-colored basic base on a support.
Thermosensitive coloring containing color dye and organic developer as main components
In a heat-sensitive recording sheet provided with a layer, the heat-sensitive coloring layer
The phenolic compound according to claim 1 as a color developer.
Thermosensitive recording sheet characterized by containing at least one kind
G. 3. The method according to claim 1, wherein said thermosensitive coloring layer comprises 1,2-
Di (3-methylphenoxy) ethane, oxalic acid di (p-
Methylbenzyl), p-benzylbiphenyl, β-ben
Jiloxynaphthalene, 4-biphenyl-p-tolyl
-Tel, m-terphenyl, 1,2-diphenoxyethane
Emissions, oxalic acid dibenzyl, and oxalic acid di (p- Kurorube
And at least one compound selected from the group consisting of
3. The heat-sensitive recording sheet according to claim 2, wherein
G.