JPS62155252A - Novel triphenyl compound - Google Patents

Abstract

NEW MATERIAL:p-Benzyloxy-(p'-methylbenzylmercapto)benzene of the formula. USE:It is used as a sensitivity increaser in thermally sensitive recording material utilizing color-developing reaction between a lueco dye and its coupler. It is suitable for high-speed recording, because of its satisfactory color intensity and sensitivity, high whiteness and high storage stability. PREPARATION:The reaction of monothiohydroquinone with a halogenated xylene under alkaline conditions is followed by reaction of the product with a halogenated benzyl to give the objective triphenyl compound.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a compound useful as a sensitivity improver in a heat-sensitive recording material that utilizes a color-forming reaction between a leuco dye and its color developer.

[Prior art]

General heat-sensitive recording materials are coated on a support such as paper or film, and contain a colorless or light-colored dye such as a leuco dye as a color former, and a phenolic compound (particularly bisphenol A) as a color developer to make the color develop when heated. A heat-sensitive coloring layer in which a binder, a filler, a sensitivity improver, a lubricant, and other auxiliary agents are further dispersed in a coloring system made of an acidic substance such as an organic acid is provided. Kosho 45-14
No. 039 and Japanese Patent Application Laid-Open No. 48-27736, it has been widely put into practical use. This type of thermal recording sheet produces a colored image through an instantaneous chemical reaction between a coloring agent and a color developer during heating (a thermal printer or facsimile machine with a built-in thermal head is used for heating). because there is,
Compared to other recording materials, records can be obtained in a short time using relatively simple equipment without complicated processing such as development and fixing, there is less noise generation and environmental pollution, and the cost is low. Due to the advantages of
It is useful as a recording material for various information and measuring instruments such as medical measuring instruments.

On the other hand, in recent years, along with the development of society, the demand for higher speed and higher density recording has increased. For this reason, there is a strong desire not only to increase the speed of the recording apparatus itself, but also to develop recording materials that can handle this. The first method is to lower the melting point of the electron-accepting compound used as a color developer to a practically acceptable level (for example, 80 to 120
C) Lowering the melting start temperature with L and leuco dye to increase the melting speed. However, it is difficult to adjust the melting point of phenolic compounds, which are color developers that are currently widely used in the field of heat-sensitive recording materials, and the phenolic compounds themselves are expensive, making them impractical. . As a second method, for example, JP-A-53-39
No. 139, JP-A-53-26139, JP-A-53-5
As described in No. 636, JP-A No. 53-11036, etc., various waxes, fatty acid amides, alkylated biphenyls, substituted biphenylalkanes, coumarins, diphenylamines, etc. with low melting points are used in the heat-sensitive coloring layer. There is a method of adding a melting substance as a sensitizer (or melting point depressant). However, it is fair to say that the heat-sensitive recording materials produced based on these methods are still satisfactory in terms of color density, color sensitivity, background whiteness, etc.

〔the purpose〕

An object of the present invention is to provide a novel compound that has sufficient color density and color development sensitivity, is suitable for high-speed recording, and has high background whiteness and is highly practical as a sensitivity improver for heat-sensitive recording materials.

〔composition〕

As a result of various studies aimed at achieving the above object, the present inventors discovered that the triphenyl compound represented by formula 1 is suitable for the purpose, and completed the present invention.

The triphenyl compound represented by the above formula of the present invention can be easily produced in high yield and by reacting monothiohydroquinone and halogenated xylene under alkaline conditions, and further reacting halogenated benzyl under the same conditions. It can be synthesized with high purity and at relatively low cost.

The triphenyl compound of the present invention can be used as an excellent sensitivity improver for heat sensitivity and high-speed recording, and furthermore, the heat-sensitive recording material obtained using the same has excellent stability in the background area and colored area and high speed recording. It also has excellent color development. In addition, heat-sensitive recording materials that use low-melting substances such as various waxes, fatty acid amides, alkylated biphenyls, substituted biphenylalkanes, coumarins, and diphenylamines, which are conventionally known as sensitizers (or melting point depressants), are color-forming. However, the triphenyl compound of the present invention is an excellent sensitivity enhancer that does not have these drawbacks. can.

When producing a heat-sensitive recording material using the triphenyl compound of the present invention as a sensitivity improver, the triphenyl compound of the present invention may be used in combination with a coloring system consisting of a conventionally known leuco dye and a color developer. In this case, the leuco dye may be applied singly or in a mixture of two or more, and any leuco dye that has been applied to this type of heat-sensitive material may be used, for example, triphenylmethane. Preferably used are leuco compounds of dyes such as dyes based on dyes such as dyes based on dyes such as dyes based on dyes such as dyes based on dyes such as dyes based on dyes such as dyes based on dyes based on dyes such as dyes based on dyes such as dyes based on dyes based on dyes such as dyes based on dyes based on dyes such as dyes based on leuco dyes, fluoran dyes, phenothiazine dyes, auramine dyes, spiropyran dyes, spiropyran dyes, and indolinophthalide dyes. Specific examples of such leuco dyes include those shown below.

3.3-bis(P-dimethylaminophenyl)-phthalide, 3.3-his(ρ-dimethylaminophenyl)-6-dimethylaminophthalide (also known as crystal violet lactone), 3.3-bis(p- dimethylaminophenyl)-6-dibutylaminophenyl, 3.3-bis(p-dimethylaminophenyl)-6-chlorophthalide, 3.3-bis(p-dibutylaminophenyl)phthalide, 3-cyclohexylamino-6- Chlorfluorane, 3-dimethylamino-5,7-dimethylfluorane, 3
-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6
-Methyl-7-chlorofluorane, 3-(N-ρ-toly-N-ethylamino)-6-methyl-7-anilinofluorane.

3-pyrrolidino-6-methyl-7-anilinofluorane, 2-(N-(3'-trifluoromethylphenyl)
amino)-6-dinithylaminofluorane, 2-(3
, 6-bis(diethylamino)-9-(o-chloroanilino)xantylbenzoic acid lactam).

3-diethylamino-6-methyl-7-(m-trichloromethylanilino)fluoran, 3-diethylamino-7-(o-chloroanilino)fluoran, 3-dibutylamino-7-(o-chloroanilino)fluoran.

3-N-methyl-N-amylamino-6-methyl-7-
Anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane.

3-diethylamino-6-methyl-7-anilinofluorane, 3-(N,N-diethylamino)-5-methyl-7-(
N.

N-dibenzylamino)fluoran, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrylospirane, 6'-bromo-3'-methoxy-benzoindolino-
Pyrillospiran, 3-(2'-hydroxy-4'-dimethylaminophenyl)-3-(2'-methoxy-5'-chlorphenyl)phthalide, 3-(2'-hydroxy-4'-dimethylaminophenyl)- 3-(2'-methoxy-5'-nitrophenyl)phthalide, 3-(2'-hydroxy-4'-diethylaminophenyl)-3-(2'-methoxy-5'-methylphenyl)phthalide, 3T- (2'-methoxy-4'-dimethylaminophenyl)-3-(2'-hydroxy-4'-chloro-5
'-Methylphenyl)phthalide, 3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7- (N-benzyl-trifluoromethylanilino)fluoran, 3-pyrrolidino-7-(di-ρ-chlorophenyl)methylaminofluorane, 3-diethylamino-5-chloro-7-(α-phenylethylamino)fluoran, 3-(N-ethyl-P-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(o-methoxycarbonylphenylamino)fluoran, 3-diethylamino-5-methyl-7-( α-phenylethylamino)fluoran, 3-diethylamino-7-piperidinofluorane.

2-chloro-3-(N-methyl 1-luidino)-7-(
p-n-butylanilino)fluorane, 3-(N-benzyl-N-cyclohexylamino)-5
．． 6-Penzo 7-α-naphthylamino-4'-bromofluorane.

3-diethylamino-6-chloro-7-anilinofluorane, 3-N-ethyl-N-(2-ethoxypropyl)amino-6-methyl-7-anilinofluorane.

3-N-ethyl-N-tetrahydrofurfurylamino-
6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-mesitidino 4', 5'-benzofluorane and the like.

Further, as the color developer used when producing a heat-sensitive recording material using the triphenyl compound of the present invention as a sensitivity improver, there are various electron-accepting compounds such as phenolic compounds, thiophenolic compounds, Thiourea derivatives, organic acids, metal salts thereof, and the like are preferably used, and specific examples thereof are shown below.

4.4'-isopropylidene bisphenol, 4.4
′ -isopropylidene bis(0-methylphenol)
, 4.4'-Secondary-butylidene bisphenol,
4.4'-isopropylidene bis(2-tertiary-
butylphenol).

4.4'-cyclohexylidene diphenol, 4.4'
-isopropylidene bis(2-chlorophenol).

2.2'-methylenebis(4-methyl-6-tert-butylphenol), 2.2'-methylenebis(4-ethyl-6-tert-butylphenol), 4.4'-butylidenebis(6-tart, butyl-
2-methyl)phenol, 4,4'-thiobis(6-tert,butyl-2-methyl)phenol, 4,4'-diphenolsulfone.

4.4'-Diphenol sulfoxide, isopropyl P-hydroxybenzoate, benzyl P-hydroxybenzoate.

benzyl protocatechuate, stearyl gallate, Lauryl gallate.

Octyl gallate, 1,7-bis(4-hydroxyphenylthio)-3,5
-Dioxahebutane, 1.5-bis(4-hydroxyphenylthio)-3-oxapentane, 1.3-bis(4-hydroxyphenylthio)-propane, 1.3-bis(4-hydroxyphenylthio) -2-hydroxypropane, N,N'-diphenylthiourea, N,N'-di(m-chlorophenyl)thiourea, salicylanilide, 5-chloro-salicylanilide, 2-hydroxy-3-naphthoic acid, 2- Hydroxy-1-naphthoic acid.

1-hydroxy-2-naphthoic acid, metal salts of hydroxynaphthoic acid such as zinc, aluminum, calcium, etc.

In order to produce a heat-sensitive recording material using the triphenyl compound of the present invention, the triphenylated compound of the present invention, the leuco dye, the color developer, and auxiliary components may be bonded and supported on a support. As the binder in this case, various commonly used binders can be used as appropriate. For example, polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose. , sodium polyacrylate, polyvinylpyrrolidone, acrylic amide/acrylic ester copolymer, acrylic amide/acrylic ester/methacrylic acid ternary copolymer, styrene/maleic anhydride copolymer alkali salt, isobutylene/anhydride Maleic acid copolymer alkali salt, polyacrylamide, sodium alginate,
In addition to water-soluble polymers such as gelatin and casein, polyvinyl acetate, polyurethane, styrene/butadiene copolymers,
Polyacrylic acid, polyacrylic ester, vinyl chloride/vinyl acetate copolymer, polybutyl methacrylate-1-,
Latex such as ethylene/vinyl acetate copolymer, styrene/butadiene/acrylic copolymer, etc. can be used.

In addition to the above-mentioned triphenyl compound, the above-mentioned leuco dye and color developer, 1 auxiliary additive components commonly used in this type of heat-sensitive recording material may also be added, for example, fillers, surfactants, thermofusible substances (or lubricant) etc. can be used in combination. In this case, fillers include, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, and surface-treated inorganic fine powders such as calcium and silica. , urea-formalin resin, styrene/methacrylic acid copolymer, polystyrene resin, and other organic fine powders.

In the heat-sensitive recording material using the triphenyl compound of the present invention, the amounts of the leuco dye, the color developer, and the triphenyl compound of the above formula are 5 to 40% by weight, 20 to 60% by weight, and 20 to 60% by weight, respectively. % is appropriate.

〔effect〕

The heat-sensitive recording material using the triphenyl compound of the present invention as a sensitivity enhancer has improved sensitivity, is suitable for high-speed recording, has high background whiteness, has excellent storage stability, and is extremely practical. It is something.

〔Example〕

Examples of the present invention are shown below. Note that parts and percentages shown below are parts by weight and percentages by weight, respectively.

Example 1 7.5 g of sodium hydroxide is dissolved in 100 g of methanol, and 23.6 g of P-hydroxybenzenethiol is added. This mixture was then added with α-chloro-ρ-xylene 2
5.0 g was added dropwise at room temperature, and after the dropwise addition was completed, the mixture was heated and reacted under methanol reflux conditions for 4 hours. After the heating reaction is completed, the mixture is cooled and filtered. After methanol was distilled off under reduced pressure from the filtered mother liquor, 2Q of water was added to the residue, and the precipitated crystals were collected by filtration and washed thoroughly with water.

After drying, recrystallize from toluene-hexane solvent to obtain 4-(P
-Methylbenzyl)mercaptophenol white crystals 1
9.9g was obtained. Furthermore, this is added to a solution of 3.8 g of sodium hydroxide in 80 g of methanol. Next, 12.0 g of benzyl chloride was added dropwise to this mixture at room temperature, and after the dropwise addition was completed, the mixture was heated and reacted under methanol reflux conditions for 4 hours. After the reaction was completed, the mixture was cooled, and the precipitated crystals were collected by filtration and thoroughly washed with methanol and water. After drying, it was recrystallized with a mixed solvent of hexane-1 and toluene to obtain 18.6 g of white crystals of ρ-benzyloxy(p-methylbenzylmercapto)benzene. Melting point 95-93°C
0 Elemental analysis results Carbon Hydrogen Yellowing theoretical value 78.71% 6.29% 10.00%Synthetic product 78.55% 6.23% 9.91%Application example 1 Mixtures of the following formulations were each mixed in a magnetic ball mill. The mixture was pulverized and dispersed for several days to prepare liquids A, B and C.

[Liquid A prescription]

3-(N-methyl-N-cyclohexylamino)-6-
Methyl-7-anirite fluorane 20 parts 10% aqueous solution of hydroxyethyl cellulose 20 parts Water
60 parts [Liquid B formulation] Bisphenol A 20 parts 10% aqueous solution of hydroxyethyl cellulose 20 parts Water
60 [Liquid C formulation] P-benzyloxy-(p-methylbenzylmercaptobenzene (melting point 78-79°C)) 20 parts 5% aqueous solution of methylcellulose 20 Water
6 Qtt [Liquid D formulation] Calcium carbonate 20 parts Methyl cellulose 5% aqueous solution 20 Il water
60!
! Next, part Ag2O, 30 parts of liquid B, 30 parts of liquid C, 20 parts of liquid D.
part and 20% of isobutylene-maleic anhydride copolymer
10 parts of an alkaline aqueous solution were mixed to form a thermosensitive coloring layer forming solution, and this was coated onto high-quality paper with a tsubo fit of 50g/m to a dry adhesion amount of 4 to 5 g/n (after coating and drying to form a thermosensitive coloring layer, Furthermore, the layer surface was calendered to obtain a heat-sensitive recording material (,
l) was created.

Application Example 2 Heat-sensitive recording material (b) was prepared in the same manner as Application Example 1 except that the following liquid (E) was used instead of the CB) liquid in Application Example 1.
It was created.

[E liquid prescription]

p-hydroxybenzoic acid benzyl ester 20 parts 10% aqueous solution of hydroxyethyl cellulose 20! ! water
60! ! Application Example 3 Heat-sensitive recording material (c) was prepared in the same manner as Application Example 1 except that the following CF) liquid was used instead of [B) liquid in Application Example 1.
It was created.

[F liquid prescription]

1,7-bis(4-hydroxyphenylthio)-3,5
-Dioxahebutane 20 parts 10% aqueous solution of hydroxyethyl cellulose 20 parts Water
6oIl Comparative Example 1 Application Example 1 except that water was used instead of liquid [c] in Application Example 1.
A thermosensitive recording material (d) was prepared in the same manner as above.

Ratio 1 Example 2 A thermosensitive recording material (c) was prepared in the same manner as in Application Example 2 except that water was used instead of the liquid (C) in Application Example 2.

Comparative Example 3 A heat-sensitive recording material (f) was prepared in the same manner as in Application Example 3 except that water was used instead of liquid (C) in Application Example 3.

Comparative Example 4 A heat-sensitive recording material (g) was prepared in the same manner as in Application Example 1, except that the following liquid [G] was used instead of liquid (c) in Application Example 1.

[Liquid G formulation] Stearic acid amide 20 parts 5% aqueous solution of methylcellulose 20" water
60//Comparative Example 5 A thermosensitive recording material (h) was prepared in the same manner as in Application Example 2 except that the liquid (G) was used instead of the liquid (C) in Application Example 2.

Comparative Example 6 A heat-sensitive recording material (i) was obtained in the same manner as in Application Example 3, except that the liquid [G] was used instead of liquid [C] in Application Example 3.

Thermosensitive recording materials (a) to (i) obtained as described above.

The head power was 0.45111/dot 1 ~. using a thermal printing experimental device with a thin film head made by Matsushita Electronics. The pulse width was 1.6.2.0.2.4 under the conditions of 1 line recording time of 20 m5ec/Q and scanning line density of 8 x 3.85 dots/mm.
(msec), and the print density was measured using a Macbeth densitometer 11D-514 (Filterly 106).

The results are shown in Table-1.

Table 1 Next, heat-sensitive recording materials (a) to (i) were subjected to a 24-hour storage test under dry conditions at 60° C., and changes in skin density were examined. The results are shown in Table-2.

Table 2 As is clear from Tables 1 and 2, the heat-sensitive recording material formed using the triphenyl compound of the present invention as a sensitivity improver has excellent color development during high-speed recording, and has excellent storage stability in the background area. It can be seen that it is an extremely excellent heat-sensitive recording material.

Claims (1)

[Claims] (1) Formula ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ A triphenyl compound represented by