JPH05294978A - Organosilicon compound and heat-sensitive recording material using the same - Google Patents

Abstract

PURPOSE:To provide the subject new compound capable of giving heat-sensitive recording materials excellent in picture image preservability. CONSTITUTION:The objective compound of the formula (t denotes tertiary; Bu denotes butyl; Me denotes methyl), which can be obtained by reaction between a phenolic compound [e.g. 4,4'-bis(4-hydroxyphenyl)sulfone] and a silylating agent (e.g. t-butyldimethylsilyl chloride) through agitation a whole day and night in the presence of a base such as triethylamine in a solvent such as ethyl acetate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel organic silicon compound and a heat-sensitive recording material using the same, which is excellent in image storability.

[0002]

2. Description of the Related Art A heat-sensitive recording material generally comprises a support and a heat-sensitive recording layer containing an electron-donating, usually colorless or light-colored dye precursor and an electron-accepting developer as main components. By heating with a head, hot pen, laser light, etc.,
A dye precursor and a developer react instantaneously to obtain a recorded image. JP-B-43-4160 and JP-B-45-140.
No. 39, etc. Such heat-sensitive recording materials have the advantages that they can be recorded with a relatively simple device, are easy to maintain, and do not generate noise.Measurement recorders, facsimiles, printers, computer terminals, labels, etc. , Is used in a wide range of fields such as ticket vending machines. Particularly in the field of facsimiles, the demand for the heat-sensitive system has greatly increased, and along with this, there has been an attempt to increase the speed for reducing the transmission cost, downsize the device, and reduce the price. As a result, the amount of applied energy for image printing has been decreasing in recent years. Therefore, a high-sensitivity heat-sensitive recording material having a high thermal response capable of coping with speeding up and energy saving of such a facsimile has been developed.
However, in high-speed recording, the minute thermal energy released from the thermal head in an extremely short time (usually 1 millisecond or less) is efficiently used for the color development reaction, while the result that the image storability deteriorates. Invited. To solve this problem, a glycidyl compound disclosed in JP-A-62-164579, a phosphorus compound disclosed in JP-A-62-90284,
Many image storability improvers such as hindered phenols disclosed in JP-A-62-35878 have been proposed. However, none of them has a problem that they are not suitable for the industrial production of thermal papers because of their insufficient storability improving effect or because of the safety of the compounds themselves and the difficulty of industrial production. Therefore, thermal paper with satisfactory image storability could not be industrially manufactured so far.

In addition, sensitizers are used in high-sensitivity papers for fax machines at present, and they also cause deterioration of image storability. For example, JP-A-57-64593 and JP-A-58-87094 disclose naphthol derivatives, JP-A-57-64592, JP-A-57-185187, and JP-A-57-191809.
JP-A-58-110289, JP-A-59-153
No. 93 discloses a naphthoic acid derivative, which is disclosed in JP-A-58-72.
499, JP-A-58-87088, JP-A-58.
-87094 and British Published Patent No. 2165953
It is proposed in the specification to use ether and ester derivatives of phenolic compounds. The current high-sensitivity thermal papers are manufactured using these, but there is a limit to the improvement of storage stability by blending.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to obtain a heat sensitive recording material having excellent image storability.

[0005]

A thermosensitive recording material containing a colorless or light-colored dye precursor and an electron-accepting compound (developing agent) which reacts with heating to form a color on the dye precursor is described above. By containing the organosilicon compound represented by 2, a heat-sensitive recording material excellent in image storability could be obtained.

In Chemical Formula 2, Z represents an alkyl group, an aralkyl group, an aryl group or a hydrogen atom. The substituents represented by Z may be different from each other, but the number of hydrogen atoms is 1 or less. X is a single bond, carbonyl, sulfoxide, sulfone, sulfide, alkylene, cycloalkylene,
It represents an oxygen atom or a linking group having 2 or more carbon atoms in the main chain. R
Represents a lower alkyl group having 4 or less carbon atoms or a halogen atom. R'is a lower alkyl group having 4 or less carbon atoms, a lower alkoxy group having 4 or less carbon atoms, a halogen atom or OSiZ ' ₃
Represents. Z ′ represents the same meaning as Z. m represents an integer of 0 or more and 4 or less. n represents an integer of 0 or more and 5 or less. When m is 2 or more, the substituents represented by R may be different from each other. When n is 2 or more, the substituents represented by R'may be different from each other.

As a specific example of the substituent represented by SiZ ₃ or SiZ ' ₃ in the general formula of Chemical formula 2, a trimethylsilyl group,
Tertiary butyldimethylsilyl group, dimethylsilyl group, phenyldimethylsilyl group, phenylmethylsilyl group, benzyldimethylsilyl group, triethylsilyl group,
Examples include octadecyldimethylsilyl group and octyldimethylsilyl group. Among the linking groups represented by X, the alkylene group includes 2,2'-propylidene, 2,2'-butylidene, 1,1'-ethylidene, methylene, benzylidene, etc., and the cycloalkylene group is 1,1'-cyclohexylidene. There are den and the like, and specific examples of the linking group having 2 or more carbon atoms in the main chain include 1,2-ethylenedioxy, 1,
2-ethanedicarbonyloxy and the like can be mentioned. Specific examples of R include tertiary butyl, methyl, isopropyl, chlorine, bromine, and fluorine. R'is OSiZ ' ₃
Specific examples other than the above include butyloxy, isopropyloxy, methoxy, and ethoxy in addition to the substituents described in the specific examples of R.

The compound represented by Chemical formula 2 can be easily synthesized by a known method using corresponding phenols and silylating agents as raw materials. Of the compounds of Chemical formula 2, the compound of Chemical formula 1 is novel. In the formula below, Me is methyl, Pr
Means propyl and Bu means butyl. Further, i means iso and t means tertiary. Specific examples of the compound of the present invention other than Chemical formula 1 are shown below.

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[Chemical 3]

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[Chemical 9]

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[0020]

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[0021]

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[0022]

[Chemical 16]

Next, a specific method for producing the heat-sensitive recording material according to the present invention will be described. The heat-sensitive recording material according to the present invention generally comprises, on a support, an electron-donating, usually colorless or light-colored dye precursor and an electron-accepting compound as main components, and these are dispersed and coated in a binder to form a heat-sensitive recording layer. By heating with a thermal head, a heating pen, a laser beam or the like, a dye precursor and an electron-accepting compound react instantaneously to obtain a recorded image. JP-B-43-4160 and JP-B-45-
No. 14039 is disclosed. A pigment, a sensitizer, an anti-sticking agent and the like are added to the heat-sensitive recording layer as needed. An existing storability improver may be used in combination.

The dye precursor used in the heat-sensitive recording material of the present invention is not particularly limited as long as it is generally used for pressure-sensitive recording paper or heat-sensitive recording paper.

Specific examples are (1) triarylmethane compounds 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), 3,3-bis (p) -Dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3-
(1,2-dimethylindol-3-yl) phthalide,
3- (p-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-phenylindole-
3-yl) phthalide, 3,3-bis (1,2-dimethylindol-3-yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindole-3-)
Yl) -6-Dimethylaminophthalide, 3,3-bis (9-ethylcarbazol-3-yl) -5-dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) -5 -Dimethylaminophthalide, 3-p
-Dimethylaminophenyl-3- (1-methylpyrrol-2-yl) -6-dimethylaminophthalide and the like,

(2) Diphenylmethane compound 4,4'-bis (dimethylaminophenyl) benzhydryl benzyl ether, N-chlorophenyl leuco auramine, N-2,4,5-trichlorophenyl leuco auramine, etc.

(3) Xanthene compound Rhodamine B anilinolactam, rhodamine B-p-chloroanilinolactam, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-octylaminofluorane, 3- Diethylamino-7-phenylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-chloro-7-methylfluorane, 3-diethylamino-7- (3,4-dichloroanilino) fluorane, 3 -Diethylamino-7
-(2-chloroanilino) fluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3- (N
-Ethyl-N-tolyl) amino-6-methyl-7-anilinofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 3- (N-ethyl-N-tolyl) amino-6- Methyl-7-phenethylfluorane, 3-diethylamino-7- (4-nitroanilino) fluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3- (N-methyl-N-propyl) amino-
6-Methyl-7-anilinofluorane, 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluorane, 3- (N-methyl-N-cyclohexyl) amino-6- Methyl-7-anilinofluorane, 3
-(N-ethyl-N-tetrahydrofuryl) amino-6
-Methyl-7-anilinofluorane, etc.,

(4) Thiazine-based compounds benzoyl leuco methylene blue, p-nitrobenzoyl leuco methylene blue, etc.

(5) Spiro compounds 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3,3'-dichlorospirodinaphthopyran, 3-benzylspirodinaphthopyran, 3-methylnaphtho- (3 -Methoxybenzo) spiropyran, 3-propylspirobenzopyran and the like can be mentioned, and these can be used alone or in combination of two or more.

The color developer is not particularly limited as long as it is an acidic substance generally used in thermal paper. For example, a polyvalent metal salt such as a phenol derivative, an aromatic carboxylic acid derivative, an N, N'-diarylthiourea derivative, or a zinc salt of an organic compound can be used. Particularly preferred are phenol derivatives, specifically p-phenylphenol, p-hydroxyacetophenone and 4-hydroxy-.
4'-methyldiphenyl sulfone, 4-hydroxy-
4'-isopropoxydiphenyl sulfone, 4-hydroxy-4'-benzenesulfonyloxydiphenyl sulfone, 1,1-bis (p-hydroxyphenyl) propane, 1,1-bis (p-hydroxyphenyl) pentane, 1,1 -Bis (p-hydroxyphenyl) hexane, 1,1-bis (p-hydroxyphenyl) cyclohexane, 2,2-bis (p-hydroxyphenyl) propane, 2,2-bis (p-hydroxyphenyl) hexane, 1 , 1-bis (p-hydroxyphenyl) -2-ethylhexane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 1,1-bis (p-hydroxyphenyl) -1-phenylethane, 1,3-di- [2
-(P-Hydroxyphenyl) -2-propyl] benzene, 1,3-di- [2- (3,4-dihydroxyphenyl) -2-propyl] benzene, 1,4-di- [2-
(P-Hydroxyphenyl) -2-propyl] benzene, 4,4'-dihydroxydiphenyl ether, 4,
4'-dihydroxydiphenyl sulfone, 3,3'-dichloro-4,4'-dihydroxydiphenyl sulfone,
3,3'-diallyl-4,4'-dihydroxydiphenyl sulfone, 3,3'-dichloro-4,4'-dihydroxydiphenyl sulfide, methyl 2,2-bis (4-hydroxyphenyl) acetate, 2,2- Butyl bis (4-hydroxyphenyl) acetate, 4,4'-thiobis (2-
t-butyl-5-methylphenol), benzyl p-hydroxybenzoate, chlorobenzyl p-hydroxybenzoate, dimethyl 4-hydroxyphthalate, benzyl gallate, stearyl gallate, salicylanilide, 5-chlorosalicylanilide and the like. is there.

As the binder used in the heat-sensitive recording material, starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, polyvinyl alcohol, modified polyvinyl alcohol, polyacrylic acid soda, acrylic acid amide / acrylic acid ester copolymer. , Acrylic acid amide / acrylic acid ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, ethylene /
Water-soluble adhesive such as alkali salt or ammonium salt of maleic anhydride copolymer, polyvinyl acetate, polyurethane,
Examples thereof include latex such as polyacrylic acid ester, styrene / butadiene copolymer, acrylonitrile / butadiene copolymer, methyl acrylate / butadiene copolymer, ethylene / vinyl acetate copolymer and the like.

As a sensitizer for improving the sensitivity, waxes such as N-hydroxymethylstearic acid amide, stearic acid amide and palmitic acid amide,
Naphthol derivatives such as 2-benzyloxynaphthalene,
Biphenyl derivatives such as p-benzylbiphenyl and 4-allyloxybiphenyl, 1,2-bis (3-methylphenoxy) ethane, 2,2'-bis (4-methoxyphenoxy) diethyl ether, bis (4-methoxyphenyl) A polyether compound such as ether, carbonic acid such as diphenyl carbonate, dibenzyl oxalate, bis (p-methylbenzyl) oxalate, or an oxalate diester derivative can be added in combination.

Examples of the pigment include diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide, aluminum hydroxide and urea-formalin resin.

In addition, for the purpose of preventing head wear and sticking, higher fatty acid metal salts such as zinc stearate and calcium stearate, waxes such as paraffin, oxidized paraffin, polyethylene, oxidized polyethylene, stearic acid amide, and castor wax, , Dispersants such as sodium dioctyl sulfosuccinate, UV absorbers such as benzophenone-based and benzotriazole-based,
Furthermore, a surfactant, a fluorescent dye, etc. are added as needed.

Paper is mainly used as the support used in the present invention, but non-woven fabric, plastic film, synthetic paper, metal foil or the like or a composite sheet in which these are combined can be optionally used. In addition, an overcoat layer may be provided to protect the thermosensitive recording layer, or an undercoat layer composed of a single layer or a plurality of layers of pigments or resins may be provided between the thermosensitive recording layer and the support to produce a thermosensitive recording material. Various known techniques in the art can be used.

The smear amount of the heat-sensitive recording layer is determined by the amounts of the dye precursor which is the color-forming component and the color developer, and usually the dye smear amount of 0.
1 to 1.0 g / m ² is suitable.

The amount of the developer is 5 with respect to the dye precursor.
~ 400% by weight, especially 20-300% by weight
Is the preferable addition amount. When a sensitizer is used, 100 to 300% by weight based on the color developer is a preferable addition amount.

It should be noted that the compound of the present invention was added to the color developing agent in an amount of 5
~ 300% by weight, especially 10-200% by weight
Is the preferable addition amount.

[0039]

EXAMPLES Next, the present invention will be described in more detail by way of examples. All parts and% shown below are based on weight.

Example 1 Synthesis of Compound of Formula 1 4,4'-Bis (4-hydroxyphenyl) sulfone 1
0.0 g and triethylamine 20 g were mixed with ethyl acetate 10
Added to 0 ml. While stirring this system, a solution prepared by dissolving 12.9 g of tertiary butyldimethylsilyl chloride in ethyl acetate was added dropwise. After stirring for a whole day and night, water and ethyl acetate were added and the layers were separated. The organic layer was washed with an aqueous sodium hydrogen carbonate solution and dried over anhydrous potassium carbonate. The solvent was distilled off and the residue was dissolved in toluene to remove the insoluble matter. Toluene was distilled off and the residue was treated with hexane to give 10.1 g of the desired crystal.
Got The yield was 53%. This was recrystallized with hexane to obtain a pure product. The melting point was 119.5-121.5 degrees Celsius.

Example 2 Preparation of heat-sensitive recording material (A) Preparation of heat-sensitive coating liquid Dye precursor 3-dibutylamino-6-methyl-7
30 parts of anilinofluorane were ground with a paint conditioner together with 70 parts of a 2.5% aqueous polyvinyl alcohol solution to give a dye dispersion. Then 2,2-bis (p-
40 parts of hydroxyphenyl) propane was pulverized with a paint conditioner together with 160 parts of a 2.5% polyvinyl alcohol aqueous solution to obtain a developer dispersion. 50 parts of 2-benzyloxynaphthalene was ground with a paint conditioner together with 120 parts of a 2.5% aqueous polyvinyl alcohol solution to obtain a sensitizer dispersion. 10 parts of the compound of Chemical formula 1
It was pulverized with a paint conditioner together with 40 parts of a 5% polyvinyl alcohol aqueous solution to obtain a dispersion liquid of the compound of the present invention. Analysis of the dispersion by thin layer chromatography revealed that the compound of Chemical formula 1 was hardly hydrolyzed.

After mixing the above four kinds of dispersion liquids, the following components were added with stirring and mixed well to prepare a heat-sensitive coating liquid. Calcium carbonate 50% dispersion 60 parts Zinc stearate 40% dispersion 25 parts 10% Polyvinyl alcohol aqueous solution 160 parts Water 140 parts

(B) Preparation of heat-sensitive coated paper A coating solution having the following composition was smeared on a base paper having a basis weight of 40 g / m ^{2 so} as to have a solid content of 9 g / m ² , dried, and heat-sensitive coated. I made a paper. Calcined kaolin 100 parts Styrene-butadiene latex 50% aqueous dispersion 24 parts Water 200 parts

(C) Preparation of heat-sensitive recording material The heat-sensitive coating solution prepared in (A) was smeared onto the surface of the heat-sensitive coated paper prepared in (B) so that the solid content was 3 g / m ² . A thermosensitive recording material was prepared by drying.

Comparative Example A thermal recording material was prepared in the same manner as in Example 2 except that the dispersion liquid of the compound of Chemical formula 1 in Example 2 was omitted.

Evaluation The thermal recording papers obtained in Example 2 and Comparative Example were calendered so that the Bekk smoothness was 400 to 500 seconds.

<Evaluation of Image Preservability> A printing test was conducted using a facsimile tester TH-PMD manufactured by Okura Electric. Using a thermal head with a dot density of 8 dots / mm and a head resistance of 185Ω, head voltage 12V, pulse width 1.0
Printing was performed by energizing for milliseconds, and the optical density of the image and the background was measured with a Macbeth RD-918 type reflection densitometer. Next, this image and the background were processed for 24 hours under the condition of 60 degrees Celsius, and the optical density of the processed image and the background was measured.

Regarding the background, in both Example 2 and Comparative Example, the optical density after the treatment was about 0.10, and no fog was observed. On the other hand, when the optical density of the image portion after processing is divided by that before processing to obtain the image residual ratio, it is 91 in the second embodiment.
%, Which was a satisfactory image residual rate. On the other hand, in the comparative example, a clear density decrease of 75% was observed.

[0049]

As is clear from the examples, by incorporating the compound of the present invention, a heat-sensitive recording material excellent in image storability can be obtained.

Claims (2)

[Claims] 1. An organosilicon compound represented by the following chemical formula 1 2. A heat-sensitive recording material containing a normally colorless or light-colored dye precursor and an electron-accepting compound that reacts when heated to develop the color of the dye precursor, containing an organosilicon compound represented by the following chemical formula 2. A heat-sensitive recording material characterized by: [Chemical 2] (However, Z represents an alkyl group, an aralkyl group, an aryl group or a hydrogen atom. The substituents represented by Z may be different from each other, but the number of hydrogen atoms is 1 or less. X is a single bond or carbonyl. , Sulfoxide, sulfone, sulfide, alkylene, cycloalkylene, an oxygen atom or a linking group having 2 or more carbon atoms in the main chain, R represents a lower alkyl group having 4 or less carbon atoms or a halogen atom, and R ′ represents a carbon number. Represents a lower alkyl group having 4 or less, a lower alkoxy group having 4 or less carbon atoms, a halogen atom or OSiZ ' _3. Z'is Z
Has the same meaning as. m represents an integer of 0 or more and 4 or less.
n represents an integer of 0 or more and 5 or less. When m is 2 or more, R
The substituents represented by may be different from each other. n is 2
In the above cases, the substituents represented by R'may be different from each other. )