JPS6191259A - Fluoran compound and its preparation - Google Patents

Abstract

NEW MATERIAL:A fluoran compound of formula I (wherein R<1> is a secondary alkyl of 7-13C attached to a N atom; R2 is a 1-4C primary alkyl; R<3> and R<4> each are H, Cl or methyl; R<5> is methyl, ethyl, H or Cl). USE:A color former. Most of the fluoran derivatives of formula I are colorless white crystals themselves, and are color formers with excellent light resistance and water resistance, which will form a black color when brought into close contact with an electron-accepting substance. It has adaptability especially to high-speed facsimile. PREPARATION:A benzoylbenzoic acid derivative of formula II is allowed to undergo condensation with a hydroxydiphenylamine derivative to give an objective compound. As a condensation agent used in the synthesis of a compound of formula I, sulfuric acid in a concentration of 85-100% is used to advantage.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of industrial application The present invention relates to a novel fluoran compound and a method for producing the same.

(In the formula, -R1 is the number of carbon atoms bonded to nitrogen, which is 7.
-13 secondary alkyl group, R2 is a primary alkyl group having 1 to 4 carbon atoms, R'', and R4 are hydrogen.

chlorine or methyl group, R5 is methyl group, ethyl group,
This is a fluoran compound represented by ), which represents hydrogen or chlorine, and a method for producing the same.

Pressure-sensitive recording paper and heat-sensitive recording paper that apply a color-forming reaction caused by contact between an electron-donating color former and an electron-accepting color developer have already been widely put into practical use. A fluoran compound represented by the general formula (I) which is a color former and a method for producing the same.

(b) Conventional technology The black coloring agent used in pressure-sensitive recording paper or heat-sensitive recording paper is still only a single black coloring agent.

At present, no product has been found that satisfies all aspects such as self-color development (background fogging), fastness, and cost. Furthermore, recently there has been an increasing demand for faster speeds in facsimile machines that use thermal recording paper, and there are great expectations for coloring agents that can quickly change clear black images.

(c) Problems to be Solved by the Invention At present, black coloring agents for heat-sensitive recording paper and pressure-sensitive recording paper include, for example, 2-anilino-3-methyl-6-dinithylaminofluorane, 2- Anilino-3-methyl-6-
(N-Methyl-cyclohexylamino)-fluorane.

A typical example is 2-anilino-3-methyl-6-(N-ethyl-p-toluidino)-fluoran, but these coloring agents do not have sufficient performance especially for use in high-speed facsimiles.

The present inventor has discovered that most of the fluorane derivatives represented by the general formula (1) are colorless white crystals, and that they have light resistance and water resistance that develop a black tone when brought into close contact with a child-accepting substance. It is a coloring agent with extremely excellent properties, and when applied to heat-sensitive recording paper or pressure-sensitive recording paper, it has excellent self-coloring properties and fastness, and is a useful pigment particularly suitable for high-speed facsimile. I found that.

(d) Means for Solving the Problem The fluoranated metal compound of the present invention represented by the general formula CI) is a novel compound that has not yet been described in the literature.

In general formula (I), RX represents a secondary alkyl group having 7 to 13 carbon atoms with respect to the carbon bonded to nitrogen p-
Examples of 1 are 1-propylbutyl, 1-propyl-2
-Methylpropyl, 1-ethylpentyl, 1-methylhexyl, ], 4-dimethylpentyl, 1,3,3-trimethylbutyl, 1,3-dimethylpentyl, l-ethyl-3-methylbutyl, 1. Methylheptyl, 1-ethylhexyl, 1-ethyl-3-methylpentyl, 1,5-
dimethylhexyl, 1-methyl-3-ethylpentyl,
1-ethyl-4-methylpentyl, 1-brobylpentyl, 1-propyl-3-methylbutyl, 1-methyloctyl, 1-butylpentyl, 1-inbutyl-3-methylbutyl, 1,3-dimethylheptyl, 1- Ethylhbutyl, 1,3-diethylpentyl, 1-butyl-3-methylbutyl, 1-methylnonyl, 1-ethyloctyl,
1-propylheptyl, 1-methyldecyl.

Examples include 1-pentylhexyl, 1-methylundecyl, 1-methyldodecyl, 1-hexylheptyl and the like.

R2 represents a primary alkyl group having 1 to 4 carbon atoms with respect to the carbon bonded to nitrogen, and examples of R2 include methyl, ethyl, propyl, butyl, and 2-methylpropyl groups.

R'', R' represent hydrogen, chlorine or a methyl group, R1 represents a methyl group, ethyl group, hydrogen or chlorine, and in the compound represented by the general formula (III), R represents hydrogen or a group having 1 to 4 carbon atoms. Since it represents an alkyl group, the general formula (
Examples of the compound represented by m) include the following.

2-Methyl-4-methoxydiphenylamine, 2-ethyl-4-methoxydiphenylamine, 2,3'-dimethyl-4-ethoxydifninylamine, 2,4'-dimethyl-4-hydroxydifninylamine, 2-methyl-
4'-chloro-4-methoxydiphenylamine, 2-chloro-4-methoxydiphenylamine, 2-chloro-4
-methoxy-4'-methyldiphenylamine, 2'-chloro-4-methoxydiphenylamine, 4-methoxydiphenylamine, etc.

The fluoran compound of the present invention can be produced, for example, as follows.

A compound represented by the general formula (b) (wherein R" and R" have the above-mentioned meanings) and a compound represented by the general formula (m) (wherein, R represents hydrogen or an alkyl group having 1 to 4 carbon atoms. where R', R' and R' have the meanings given above.

) in the presence of a condensing agent,
React for several hours to several tens of hours at around ℃.

Next, it is poured into water and the precipitate that forms is filtered.

After washing with water, the cake is heated in an alkaline aqueous solution or heated in an organic solvent at high temperature to obtain slightly colored white crystals.

When this is filtered, dried, and recrystallized, the above general formula (T) is obtained.
The fluoran compound represented by is obtained as white crystals.

Here, the compound represented by the general formula (■) and the general formula (m
) As the condensing agent used when synthesizing the compound of general formula (1) from the compound of formula (1), sulfuric acid, phosphoric acid, polyphosphoric acid, etc. are used, but preferably sulfuric acid with a concentration of 85% to 100% is used. . Further, during this condensation reaction, solvents such as halogenated aliphatic hydrocarbons, halogenated aromatic hydrocarbons, acetic acid, and dioxane may be used, and these solvents may be removed at an appropriate time during the synthesis.

After the condensation reaction, the fluoran compound can be separated from the alkaline aqueous solution by filtration as described above, or by extraction using an organic solvent that is immiscible with the water added during the alkali treatment.

The purity of the fluoran compound treated with an alkali by such a method can be further increased by using an organic solvent. Examples of organic solvents for high temperature treatment or recrystallization include orthodichlorobenzene, anisole, 1,
2.4- Trimethylbenzene.

Ortho-xylene, isopropylbenzene, diisopropylbenzene, paracymene, 2-ethylhexanol,
Cyclohexanol, benzyl alcohol, furfuryl alcohol, ethylene glycol, 2-butoxyshetanol, decane, dimethylformamide, toluene, chlorobenzene, methyl isobutyl ketone, isobutanol, impropatol, methanol, acetone, n-hexane, etc. used.

Heat-sensitive or pressure-sensitive recording paper can be produced by a conventional method using one or more of the color formers thus obtained, or in combination with other color formers. Examples of color developers commonly used at this time include bisphenol A,
Bisphenols such as cyclohexylidene bisphenol, phenylphenol, alkylphenols, P
-oxybenzoic acid benzyl ester, etc.
Fragrant acid.

Esters of oxynaphthoic acid, formalin novolac resin of phenol ° alkylphenol.

Examples include sulfur chloride condensates of alkylphenols, salicylic acid salts, Ishifunesuka L Shiriki J lesium spots, iodine clays, clays, aromatic carboxylic acids and sulfonic acids, and their metal salts.

In addition to the glue, light stabilizer, and lubricant normally used in the production of recording paper, there is also a flux in thermal paper.

It is generally well known that a capsule material and a capsule solvent are used in pressure-sensitive paper.

The benzoylbenzoic acid derivative represented by the general formula (II), which is the starting material for producing the fluoran compound of the present invention, is obtained by catalytic reduction alkylation of 1m-aminophenol with a ketone compound to obtain an N-monosubstituted m-aminophenol derivative ( IV) (wherein R1 has the above meaning)
and further N-alkylated with an alkylating agent to obtain N,N-disubstituted m-aminophenol derivative (V) (
In the formula, R1 and RZ have the above meanings. ), then
It was synthesized by condensation with phthalic anhydride.

(e) Actions and Effects The fluoran compound represented by the general formula (1) of the present invention is a new compound that has not been described in any literature, and the pressure-sensitive or heat-sensitive recording paper produced in combination with the color developer has the following properties: Storage stability 1: Particularly excellent in color development, light resistance, and water resistance. That is, recording paper using five color formers was treated with 2-anilino-3-methyl-6-(2-anilino-3-methyl-6-(
N-diethylamino)fluoran, 2-anilino-3-
Compared to those using methyl-6-(N-cyclohexyl-N-methylamino)fluoran and fluoran, capsule-coated paper has less discoloration due to light in pressure-sensitive paper, and the light fastness and moisture fastness of colored images are improved. Excellent light for background and colored images on thermal paper.

It has excellent stability against heat and humidity, and is suitable for high-speed facsimile.

(f) Example Next, the present invention will be explained in more detail with reference to Examples.

Example 1 2-(4-N-1'-isobutyl-
3'-Methylbutyl-N-methylamino-2-hydroxybenzoyl)benzoic acid (melting point 171-172°C)3.
Dissolve 98g of 2-methyl-4 at 10-15°C.
-Dissolve 2.13 g of methoxydiphenylamine and stir at the same temperature for 24 hours.

After pouring into 100 g of ice water, the precipitate was filtered and washed with water, the cake was poured into 50 cc of water, and 2. Add dragonfly and 20 g of toluene and stir at 85°C for 3 hours. Separate the toluene layer, wash twice with 30 cc of hot water, separate the layers, distill off the toluene, add 10 g of methanol, heat, and cool.
The crystals were filtered and washed with methanol.

This was prepared with 10 g of 80% acetone and dried. 2-anilino-3-methyl-5-(N-1'-isobutyl-3'-methylbutyl-
N-methylamino)-fluorane4. Og was obtained as white crystals. It develops a black color with silica gel, benzyl P-oxybenzoate, and bisphenol.

Example 2 3.7 g of 2-(4-N-1'-propylbutyl-N-methylamino-2-hydroxybenzoyl)benzoic acid (melting point 144.5-146°C) was dissolved in 25 g of 96% sulfuric acid, and then 2.13 g of 2-methyl-4-methoxydiphenylamine is dissolved at 10-15°C and stirred at the same temperature for 24 hours. Ice water 80. filter the precipitate, wash with water,
Put the cake in 50 cc of water, add 2.5 g of caustic soda and 15 g of toluene, and stir at 85° C. for 2 hours. After separating the toluene layer and washing with water, the toluene was distilled off and 8 g of acetone was added.
Add and heat to dissolve, add 2g of wood and cool. The crystals were filtered, washed with 15 cc of 80% acetone, and dried. This was heated with 5 g of isopropanol, cooled, and the crystals were filtered, washed with inpropatool and dried. Melting point 146-1
2-anilino-3-methyl-6-(N-1'-
Propylbutyl-N-methylamino)fluorane 2.8
5 g was obtained as white crystals. It develops a black color due to silica gel and bisphenol A.

Example 3 2-(4-N-1'-isobutyl-
1.99 g of 3'-methylbutyl-N-methylamino-2-hydroxybenzoyl)°benzoic acid and 1.07 g of 2,4'-dimethyl-4-hydroxydiphenylamine are dissolved and stirred at 10-15°C for 24 hours. 80g ice water
and filter the precipitate.

After washing with water, the cake was placed in water, made alkaline with caustic soda, heated, filtered, washed with water, and dried. This was purified with 90% methanol and isopropanol and dried. Melting point 1
2-(4'-methylanilino)-3- at 76-178°C
1.55 g of methyl-6-(N-1'-isobutyl-3'-methylbutyl-N-methylamino)-fluorane was obtained as white crystals. Silica gel produces a black color, and bisphenol A produces a green-black color.

Example 4 As a benzoylbenzoic acid derivative, 2-(4-N-1
The procedure was as in Example 3 using 1.85 g of '-propylbutyl-N-methylamino-2-hydroxybenzoyl)benzoic acid. 2-(
4'-methylanilino)-3-methyl-6-(N-1'
-Propylbutyl-N-methylamino)fluorane 16
5 g was obtained as white crystals. Silica gel produces a black color, and bisphenol A produces a green-black color.

Example 5 15 g of 96% sulfuric acid, 2-(4-N-1'-propylbutyl-N-methylamino-2-hydroxybenzoyl)
85 g of benzoic acid 1 and 99 g of 4-methoxydiphenylamine 1 are used and stirred for 24 hours at 10-15°C. Pour into 80g of ice water, filter, wash with water, put the cake in water and make alkaline with soda carbonate, filter, wash with water,
Dry.

This was heated with 5 g of ethylene glycol to 165°C for 5 minutes, filtered with 5 g of cold methanol, and washed with methanol. Purified with impropat tool, melting point 163-164
2-anilino-6-(N-1'-propylbutyl-
1.3 g of N-methylamino)fluorane was obtained as white crystals. It develops a dark green color due to silica gel and bisphenol A.

Example 6 15 g of 96% sulfuric acid, 99 g of 2-(4-N-1'-isobutyl-3'-methylbutyl-N, methylamino-2-hydroxybenzoyl)benzoic acid and 2''-chloro,4-methoxydiphenylamine 1.17g for 10~
The mixture was reacted at 15° C. for 24 hours, poured into ice water, and the resulting precipitate was filtered and washed with water. Place the cake in a 50 cc wooden container, add 2.5 g of caustic soda and 10 g of toluene, and stir at 85° C. for 2 hours. After the toluene layer was separated and washed with water, the toluene was distilled off, and recrystallization was repeated from 90% inproper tool. 2- (2'-
Chloranilino)-6-(N-1'-isobutyl-3''
-Methylbutyl-N-methylamino)fluorane 1.6
g was obtained as white crystals. Purple-black due to silica gel,
It develops a black color due to bisphenol A.

Example 7 As benzoylbenzoin W & derivative, 2-(4-N-
1'-propylbutyl-N-methylamino-2-hydroxybenzoyl) benzoin fi1. The same procedure as in Example 6 was carried out using 115 g of 115 g. The crude product obtained by distilling off the toluene was recrystallized from Impropatol and 90% Impropatul to obtain 2-(2'-chloroanilino)-6-(N-1'-propylbutyl) with a melting point of 80-82°C. -N
2.0 g of -methylamino)fluorane was obtained as white crystals. Silica gel produces a purple-black color, and bisphenol A produces a black color.

Example 8 The same procedure as in Example 6 was carried out using 1.17 g of 2-chloro-4-methoxydiphenylamine as the hydroxydiphenylamine derivative. The crude product obtained by distilling off the toluene was repeatedly purified using 80% methanol. 2-anilino-3-chloro6 with a melting point of 90-92°C
-(N-1'-isobutyl-3'-methylbutyl-N-
1.5 g of methylamino)fluorane was obtained as white crystals. It develops a black color due to silica gel and bisphenol A.

Claims (2)

[Claims] (1) General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R^1 is a secondary alkyl group with 7 to 13 carbon atoms regarding the carbon bonded to nitrogen, R^ 2 represents a primary alkyl group having 1 to 4 carbon atoms, R^3 and R^4 represent hydrogen, chlorine or methyl group, and R^5 represents methyl group, ethyl group, hydrogen or chlorine). Compound. (2) General formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) (In the formula, R^1 is a secondary alkyl group having 7 to 13 carbon atoms with respect to the carbon bonded to nitrogen, R^ 2 represents a primary alkyl group with 1 to 4 carbon atoms.) The benzoylbenzoic acid derivative represented by the general formula (III) ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ (III) (wherein, R is hydrogen or An alkyl group having 1 to 4 carbon atoms,
R^3 and R^4 are hydrogen, chlorine or methyl group, R^
5 represents a methyl group, an ethyl group, hydrogen or chlorine. ) General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc. are available▼(I) A method for producing a fluoran compound, characterized by condensation with a hydroxydiphenylamine derivative represented by (I).