GB2288606A - Phenylimine derivatives of benzoyl aromatic compounds and recording material comprising the same - Google Patents

Abstract

A phenylimine compound of formula (1> <IMAGE> [wherein R is a lower alkyl, a lower alkoxy or a dialkylamino group; R<1> is a lower alkyl or a lower alkoxy group; n and m are 0, 1 or 2; and Y is a group of formula (2), (3) or (4): <IMAGE> wherein R<2> and R<3> are independantly a lower alkyl group, a benzyl group or a phenyl group which may be substituted, or R<2> and R<3> together with the nitrogen atom to which they are bound form a pyrrolidine ring; R<4> is hydrogen, or a lower alkyl or a lower alkoxy group; R<5> is hydrogen or a lower alkyl group; R<6> is hydrogen, or a lower alkyl or a phenyl group; and R<7> is hydrogen or a lower alkyl group], and a recording material which contains it as a color developable compound, are disclosed. The above phenylimine compound is useful as a color coupler of yellow/orange system.

Description

Phenylimine Compound and Recording Material comprising the Same [Field of the Invention] The present invention relates to a novel phenylimine compound which forms yellow to orange color when contacted with an electron accepting color developer such as an organic acid, an inorganic acid, a phenolic compound, an aromatic carboxylate metal salt, a salicylate metal salt and an electron accepting clay mineral or with an oxidizing agent such as a substituted parabenzoquinone.

[Prior Arts] Pressure sensitive recording materials, thermal recording materials, photosensitive recording materials, electro-thermo recording materials and thermal transfer recording materials are well known as recording materials in which a colored image is obtained by the reaction of an electron donating pigment with an electron accepting color developer. For example, these materials are fully disclosed in British Patent No. 2,140,449, U.S. Patent No. 4,480,052, U.S. Patent No. 4,436,920, JP-B-8523992, JP-A-57-179836, JP-A-60-123556 and JP-A-60-123557.

Color couplers of various structures have been proposed especially for use in pressure sensitive and thermal recording materials, with various colored hues such as yellow, orange, red, blue, blue green and black.

Typical examples of such color couplers include fluoran compounds and phthalide compounds, each of which being required to have the following conditions: (1) it itself is colorless or of a pale color, (2) it has a high color developing rate, a high coloring density and a good light resistance, (3) it itself does not cause the color development with time, and (4) its colored image is excellent in resistances to chemicals and plasticizers.

In general, each of these color couplers is rarely used alone, and the hue of interest is obtained by blending it with a plurality of pigment having different hues.

In the case of the pressure sensitive and thermal recording materials, the pigment of yellow/orange system has been studied extensively, because such a pigment is essential especially when black color is required.

Typical examples of the color coupler of yellow/orange system include dialkoxyfluoran (JP-B-70-4698, JP-B-71-16053), monoalkylaminofluoran (JP-B-71-22650, JP-B-73-4051), chromenopyrazole compound (JP-B-71-23513), aminophthalide compound (JP-B-79-111528), acyloxy tetrachlorophthalide (JP-B70-25654), spiropyran compound (JP-B-71-10075, JP-B-71-11113), styrylquinoline derivative (JP-B-66-21033, JP-B-76-27169, JP-B84-152891), pyridine derivative (JP-B-78-9127), monomethine compound (JP-B-77-23406, JP-B-74-5929) and benzopyran compound (JP-B-71-19274).

These compounds are roughly classified into two groups depending on the presence or absence of a lactone ring. Lactone ring-containing compounds hardly cause spontaneous color development of solution on paper and are highly soluble in solvent in general, but have disadvantages in terms of low color density and inferior light resistance.

On the other hand, compounds having no lactone ring are generally high in color density and excellent in light resistance, but have disadvantages in terms of poor solubility in solvent, frequent spontaneous color development of solution on paper and poor sublimation.

[Summary of the Invention] An object of the present invention is to solve the abovementioned problems involved in the prior art color couplers of yellow/orange system.

Accordingly, the present invention relates to a phenylimine compound represented by the following general formula (1) and to a recording material which contains the above compound as a color coupler.

In the above formula, R represents a lower alkyl group, a lower alkoxy group or a dialkylamino group, R1 represents a lower alkyl group or a lower alkoxy group, each of n and m is an integer of 0, 1 or 2 and Y is a group represented by any one of the following formulae (2), (3) and (4):

wherein each of R2 and R3 independently represents a lower alkyl group, a benzyl group or a phenyl group which may be substituted, or R2 and R3 together with the nitrogen atom to which they are attached form a pyrrolidine ring, R4 represents a hydrogen atom, a lower alkyl group or a lower alkoxy group, R5 represents a hydrogen atom or a lower alkyl group, R6 represents a hydrogen atom, a lower alkyl group or a phenyl group and R7 represents a hydrogen atom or a lower alkyl group.

Illustrative examples of the compound represented by the general formula (1) include 4,4' -bis-dimethylaminobenzophenone-phenylimine, 4,4'-bis-diethylaminobenzophenone-phenylimine, 4,4'-bis-dipropylaminobenzophenone-phenylimine, 4,4 '-bis-dibutylaminobenzophenone-phenylimine, 4,4 '-bis-dimethylaminobenzophenone-p-tolylimine, 4,4'-bis-diethylaminobenzophenone-p-tolylimine, 4,4 '-bis-dipropylaminobenzophenone-p-tolylimine, 4,4.' -bis-dibutylaminobenzophenone-p-tolylimine, 4,4'-bis-dimethylaminobenzophenone-p-methoxyphenylimine, 4,4 '-bis-diethylaminobenzophenone-p-methoxyphenylimine, 4,4 '-bis-dipropylaminobenzophenone-p-methoxyphenylimine, 4,4 '-bis-dibutylaminobenzophenone-p-methoxyphenylimine, 4,4'-bis-dimethylaminobenzophenone-2",4"-dimethylphenylimine, 4,4'-bis-diethylaminobenzophenone-2",4"-dimethylphenylimine, 4,4 '-bis-dipropylaminobenzophenone-2", 4 '1-dimethylphenylimine, 4,4'-bis-dibutylaminobenzophenone-2",4"-dimethylphenylimine, 4-dimethylaminobenzophenone-phenylimine, 4-diethylaminobenzophenone-phenylimine, 4-dipropylaminobenzophenone-phenylimine, 4-dibutylaminobenzophenone-phenylimine, 4 -dimethylaminobenzophenone-p-tolylimine, 4-diethylaminobenzophenone-p-tolylimine, 4 -dipropylaminobenzophenone-p-tolylimine, 4-dibutylaminobenzophenone-p-tolylimine, 4-dimethylaminobenzophenone-p-methoxyphenylimine, 4-diethylaminobenzophenone-p-methoxyphenylimine, 4 -dipropylaminobenzophenone-p-methoxyphenylimine, 4 -dibutylaminobenzophenone-p-methoxyphenylimine, 4 -dimethylaminobenzophenone-2", 4" -dimethylphenylimine, 4-diethylaminobenzophenone-2",4"-dimethylphenylimine, 4-dipropylaminobenzophenone-2",4"-dimethylphenylimine, 4-bis-dibutylaminobenzophenone-2", 4 "-dimethylphenylimine, 4-N-methyl-N-phenylbenzophenone-phenylimine, 4-N-ethyl-N-phenylbenzophenone-phenylimine, 4-N-propyl-N-phenylbenzophenone-phenylimine, 4-N-butyl-N-phenylbenzophenone-phenylimine, 4-N-methyl-N-p-tolylbenzophenone-phenylimine, 4-N-ethyl-N-p-tolylbenzophenone-phenylimine, 4-N-propyl-N-p-tolylbenzophenone-phenylimine, 4-N-butyl-N-p-tolylbenzophenone-phenylimine, 4-N-methyl-N-p-methoxyphenylbenzophenone-phenylimine, 4 -N-ethyl-N-p-methoxyphenylbenzophenone-phenylimine, 4-N-propyl-N-p-methoxyphenylbenzophenone-phenylimine, 4-N-butyl-N-p-methoxyphenylbenzophenone-phenylimine, 4-N-methyl-N-p-benzyloxyphenylbenzophenone-phenylimine, 4-N-ethyl-N-p-benzyloxyphenylbenzophenone-phenylimine, 4-N-propyl-N-p-benzyloxyphenylbenzophenone-phenylimine, 4-N-butyl-N-p-benzyloxyphenylbenzophenone-phenylimine, 4-N-methyl-N-phenylbenzophenone-p-tolylimine, 4-N-ethyl-N-phenylbenzophenone-p-tolylimine, 4 -N-propyl-N-phenylbenzophenone-p-tolylimine, 4 -N-butyl -N-phenylbenzophenone-p-tolyl imine, 4 -N-methyl-N-p-tolylbenzophenone-p-methoxyphenylimine, 4-N-ethyl-N-p-tolylbenzophenone-p-methoxyphenylimine, 4 -N-propyl-N-p-tolylbenzophenone-p-methoxyphenylimine, 4-N-butyl-N-p-tolylbenzophenone-p-methoxyphenylimine, 4 -N-methyl-N-p-methoxyphenylbenzophenone-2", 4" - dimethylphenylimine, 4-N-ethyl-N-p-methoxyphenylbenzophenone-2",4"- dimethylphenylimine, 4-N-propyl-N-p-methoxyphenylbenzophenone-2",4"- dimethylphenylimine, 4-N-butyl-N-p-methoxyphenylbenzophenone-2",4"- dimethylphenyl imine, 4-N-methyl-N-p-benzyloxyphenylbenzophenone-2",4",6"trimethylphenylimine, 4-N-ethyl-N-p-benzyloxyphenylbenzophenone-2",4",6"- trimethylphenylimine, 4-N-propyl-N-p-benzyloxyphenylbenzophenone-2", 4", 6"- trimethylphenylimine, 4-N-butyl-N-p-benzyloxyphenylbenzophenone-2",4",6"- trimethylphenylimine, N-methyl-2-methyl-3-benzoylindole-phenylimine, N-ethyl-2-methyl-3-benzoylindole-phenylimine, N-propyl-2-methyl-3-benzoylindole-phenylimine, N-butyl-2-methyl-3-benzoylindole-phenylimine, N-methyl-2-ethyl-3-benzoylindole-phenylimine, N-ethyl-2-propyl-3-benzoylindole-phenylimine, N-propyl-2-butyl-3-benzoylindole-phenylimine, N-butyl-2-phenyl-3-benzoylindole-phenylimine, N-methyl-2-ethyl-3-benzoylindole-p-tolylimine, N-ethyl-2-propyl-3-benzoylindole-p-tolylimine, N-propyl-2-butyl-3-benzoylindole-p-tolylimine, N-butyl-2-phenyl-3-benzoylindole-p-tolylimine, N-methyl-2-ethyl-3-benzoylindole-p-methoxyphenylimine, N-ethyl-2-propyl-3-benzoylindole-p-methoxyphenylimine, N-propyl-2-butyl-3-benzoylindole-p-methoxyphenylimine, N-butyl-2-phenyl-3-benzoylindole-p-methoxyphenylimine, N-methyl-2-ethyl-3-benzoylindole-2",4"-dimethylphenylimine, N-ethyl-2-propyl-3-benzoylindole-2",4"-dimethylphenylimine, N-propyl-2-butyl-3-benzoylindole-2",4"-dimethylphenylimine, N-butyl-2-phenyl-3-benzoylindole-2",4 "-dimethylphenylimine, N-methyl-3-benzoylcarbazole-phenylimine, N-ethyl-3-benzoylcarbazole-phenylimine, N-propyl-3-benzoylcarbazole-phenylimine, N-butyl-3-benzoylcarbazole-phenylimine, N-methyl-3-benzoylcarbazole-p-methylphenylimine, N-ethyl-3-benzoylcarbazole-p-methylphenylimine, N-propyl-3-benzoylcarbazole-p-methylphenylimine, N-butyl-3-benzoylcarbazole-p-methylphenylimine, N-methyl-3-benzoylcarbazole-p-methoxyphenylimine, N-ethyl-3 -benzoylcarbazole-p-methoxyphenylimine, N-propyl-3-benzoylcarbazole-p-methoxyphenylimine, N-butyl-3-benzoylcarbazole-p-methoxyphenylimine, N-methyl-3- (p-methylbenzoyl) carbazole-phenylimine, N-ethyl-3- (p-methylbenzoyl) carbazole-phenylimine, N-propyl-3- (p-methylbenzoyl) carbazole-phenylimine, N-butyl-3- (p-methylbenzoyl) carbazole-phenylimine, N-methyl-3-(p-methoxybenzoyl)carbazole-p-methylphenylimine, N-ethyl-3- (p-methoxybenzoyl) carbazole-p-methylphenylimine, N-propyl-3- (p-methoxybenzoyl) carbazole-p-methylphenylimine and N-butyl-3- (p-methoxybenzoyl) carbazole-p-methylphenylimine.

The compound represented by the general formula (1) can be synthesized in accordance with the following scheme 1 or 2.

Scheme 1

Scheme 2

In scheme 1, corresponding compound (9), (10) or (11) of the present invention can be obtained by condensing a benzanilide derivative (5) with a substituted aniline derivative (6), a substituted indole derivative (7) or a substituted carbazole derivative (8) at a temperature of from 50 to 1500C, in the presence of an acidic condensing agent such as sulfuric acid, hydrochloric acid, nitric acid, formic acid, acetic acid, acetic anhydride, p-toluenesulfonic acid, methanesulfonic acid, perchloric acid, phosphorus oxychloride, phosphorus trichloride or phosphorus pentachloride, optionally in a solvent such as benzene, toluene, o-dichlorobenzene, chlorobenzene, chloroform, tetrachloroethylene, methanol, ethanol, i-propylalcohol or ethyl cellosolve.

In scheme 2, corresponding compound (16), (17) or (18) of the present invention can be obtained by condensing a benzophenone derivative (13), (14) or (15) with a substituted aniline derivative (12) at a temperature of from 50 to 1500C, in the presence of an acidic condensing agent such as sulfuric acid, hydrochloric acid, nitric acid, formic acid, acetic acid, acetic anhydride, p-toluenesulfonic acid, methanesulfonic acid, perchloric acid, phosphorus oxychloride, phosphorus trichloride or phosphorus pentachloride, optionally in a solvent such as benzene, toluene, o-dichlorobenzene, chlorobenzene, chloroform, tetrachloroethylene, methanol, ethanol, i-propylalcohol or ethyl cellosolve.

Production of the pressure sensitive recording material making use of the phenylimine compound represented by the general formula (1) as the color coupler can be made according to a known method disclosed for example in U.S. Patent No.

2,800,458 or U.S. Patent No. 2,800,457.

Examples of the color developer to be used include clays such as clay, bentonite, activated clay and acid clay, metal salts of salicylic acid derivatives, p-phenylphenolformalin resin, p-octylphenolformalin resin and metal salts thereof. Of these compounds, metal salts of salicylic acid derivatives are preferred from the viewpoint of color developing density and colored image stability.

Illustrative examples of the salicylic acid derivatives include salicylic acid, 3-methyl-5-tert-butylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 3-cyclohexylsalicylic acid, 5cyclohexylsalicylic acid, cresotinic acid, 5-nonylsalicylic acid, 5-cumylsalicylic acid, 3-phenylsalicylic acid, 2,5dihydroxysalicylic acid, naphthoic acid, hydroxynaphthoic acid, 3-tert-butyl-5-a-methylbenzylsalicylic acid and 3,5-di(amethylbenzyl)salicylic acid. Illustrative examples of polyvalent metals which form salts with these derivatives include zinc, magnesium, calcium, aluminium, nickel and copper, of which zinc, magnesium and calcium are preferred and zinc is particularly preferred.

Examples of binders to be used in the production of the pressure sensitive recording material include polyvinyl alcohol, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, gum arabic, gelatin, casein, starch, polyvinyl pyrrolidone and styrene-maleic anhydride copolymer. Examples of organic solvents in which the color coupler is dissolved include alkylbenzenes, alkylnaphthalenes, alkyldiphenyls, diarylethanes, hydrogenated terphenyls and chlorinated paraffins which may be used alone or as a mixture of two or more. Microcapsules can be prepared by employing a coacervation method, an interfacial polymerization method or an in-situ method.

If necessary, various antioxidants, ultraviolet ray absorbing agents and surface active agents may be used.

Production of the thermal recording material can be made according to a known method disclosed for example in JP-B-7014039.

Examples of binders to be used in the production of the thermal recording material include polyvinyl alcohol, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, gum arabic, gelatin, casein, starch, polyvinyl pyrrolidone and styrene-maleic anhydride copolymer which are commonly used in the thermal recording materials.

Illustrative examples of color developers to be used in this case include those which are known in the art, such as methyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, 2,2-bis(phydroxyphenyl)propane (bisphenol A), 3,4'isopropylidenediphenol, 2,2-bis(p-hydroxyphenyl)-4methylpentane, 2,2-bis(4-hydroxy-3-allylphenyl)propane, bis(4hydroxyphenyl)acetic acid, butyl 1,1-bis(4 hydroxyphenyl) acetate, 4,4'-cyclohexylidenediphenol, 4,4'thiodiphenol, bis-(4-hydroxy-3-methylphenyl) sulfide, bis(4hydroxy-3-tert-butyl-6-methylphenyl) sulfide, 4,4' dihydroxydiphenyl sulfone, 4-hydroxy-4'-methyldiphenyl sulfone, 3,4-dihydroxy-4'-methyldiphenyl sulfone, 4-hydroxy-4'isopropoxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone, 4,4'-dihydroxy-3,3'-diallyldiphenyl sulfone, dimethyl 4-hydroxyphthalate, bis[2-(4-hydroxyphenylthio)ethyl] ether, 4,41 -methylenebis (oxyethylenethio) diphenol, 1-benzyl-2-naphthol, 1,1 '-methylene-di-2-naphthol, p-hydroxyphenylsalicylamide, 1,3diphenyl thiourea, 1,3-ditolyl thiourea and 1,3-dichlorophenyl thiourea which may be used alone or as a mixture of two or more.

Illustrative examples of the sensitivity improving agent (sensitizer) include paraffin wax, carnauba wax, higher fatty acid ester, higher fatty acid amide, dibenzyl oxalate, di-pmethylbenzyl oxalate, di-p-chlorobenzyl oxalate, phthalic acid ester, terephthalic acid ester, benzyl 4-benzyloxybenzoate, naphtholbenzyl ether, 1,4-dialkoxynaphthalene, 1,5dialkoxynaphthalene, m-terphenyl, p-benzylbiphenyl, dibenzylbenzene, l-hydroxy-2-naphthoic acid ester, 1-phenoxy-2naphthoxy(l)ethane, 1,2-diphenoxyethane, 1,2-di(3methylphenoxy)ethane, 1- (2-isopropylphenoxy) -2- naphthoxy(2)ethane, bis(p-methoxyphenoxyethyl) ether, 2-hydroxy3-naphthoic acid ester, 4,4'-dialkoxydiphenylsulfone, benzamide, diphenylamine, benzenesulfonamide, benzenesulfonanilide, 1,4dibenzyloxybenzene, 1,4-di(vinyloxyethoxy)benzene, 1,3di(vinyloxyethoxy)benzene and diphenylcarbonate which may be used alone or as a mixture of two or more.

In order to improve the light resistance and shelf life of colored images, various antioxidants, anti-degradation agents, and UV absorbing agents may be used in addition to these sensitivity improving agents. Alternatively, the thermal recording paper may be over-coated with a high molecular compound.

When the compound of the present invention is used in the aforementioned recording materials such as the pressure sensitive recording material and the thermal recording paper, the inventive compound may be used together with other color couplers in order to improve shelf life or to obtain various color tones.

[Examples] The following examples are provided to illustrate the present invention.

Example 1 39.7 Grams of benzanilide and 36.6 g of Nmethyldiphenylamine were dissolved in 50 cc of o-dichlorobenzene at 900C. At the same temperature, to this was added dropwise 61.2 g of phosphorus oxychloride over 30 minutes. Next, the temperature was increased to 1200C to carry out the reaction for 8 hours. After completion of the reaction, the reaction mixture was poured into 500 cc of ice water containing 150 g of 48% sodium hydroxide followed by removing o-dichlorobenzene by steam distillation. The resulting tarry residue was extracted with 200 cc of toluene. The toluene layer was collected and treated with carbon, and toluene was then removed by evaporation. The resulting tarry residue was dissolved in 200 cc of ethanol and subjected to crystallization to obtain 32.5 g of ashy white crystals with a yield of 44.9%.

The thus-obtained compound represented by the following formula (1-1) showed a melting point of 1420C. When the crystals were dissolved in toluene and spotted on a piece of clay paper, bright orange color was formed. The thus-formed colored image showed its absorption maximum at 470 nm.

IR: VC=N 1590 cm-l, VC-H 2850 cm'l MS (m/e): 362 (M+)

Example 2 19.7 Grams of benzanilide and 30.6 g of phosphorus oxychloride were added to 30 g of diethylaniline, and the mixture was slowly warmed up to 1100C over 30 minutes to carry out the reaction at the same temperature for 3 hours. After completion of the reaction, 150 cc of toluene was added. Next, while keeping the water layer at a weak alkaline pH value, 80 g of 48%sodium hydroxide and the reaction mixture were alternately poured dropwise into ice water. After completion of the addition, the mixture was stirred at 600C for 1 hour, and the toluene layer was collected. The toluene layer was treated with carbon, and toluene was then removed by evaporation. The resulting tarry residue was crystallized from 100 cc of methanol to obtain 16.3 g of ashy white crystals with a yield of 49.7%.

The thus-obtained compound represented by the following formula (1-2) showed a melting point of 1170C. When the crystals were dissolved in toluene and spotted on a piece of clay paper, bright orange color was formed. The thus-formed colored image showed its Xmax at 470 nm.

IR: VC=N 1590 cam~1, VC-H 2900 cm'l MS (m/e): 328 (M+) 1H-NMR (CDCl3/TMS, 3, ppm): 1.2 (t, 6 H), 3.4 (q, 4 H), 7.1 (m, 14 H)

Example3 25.5 Grams of 4-methoxy-4'-dimethylaminobenzophenone, 18.5 g of p-anisidine and 30.6 g of phosphorus oxychloride were added to 50 cc of toluene, and the temperature of the mixture was increased to 1000C over 30 minutes. Subsequently, the reaction was carried out at the same temperature for 6 hours.

After completion of the reaction, the reaction mixture was mixed with 100 cc of toluene and poured dropwise into ice water containing 80 g of 48% sodium hydroxide. After 1 hour of stirring at 600C, the toluene layer was collected, treated with carbon and then evaporated. The resulting tarry residue was dissolved in 100 cc of ethanol and subjected to crystallization to obtain 23.5 g of light yellow crystals with a yield of 65.2%.

The thus-obtained compound represented by the following formula (1-3) showed a melting point of 129.50C. When the crystals were dissolved in toluene and spotted on a piece of clay paper, bright orange color was formed. The thus-formed colored image showed its absorption maximum at 470 nm.

IR: VC=N 1590 cam~1, VC-H 2850 cm'l MS (m/e): 360 (M+)

Example 4 42.2 Grams of N,N-ethyl-benzylaniline, 19.7 g of benzanilide and 30.6 g of phosphorus oxychloride were mixed, and theėmperature of the mixture was increased to 1100C over 30 minutes. Subsequently, the reaction was carried out at the same temperature for 4 hours. After completion of the reaction, the reaction mixture was mixed with 150 cc of toluene and poured dropwise into 500 cc of ice water containing 80 g of 48% sodium hydroxide. After 1 hour of stirring at 600C, the toluene layer was collected, treated with carbon and then evaporated. The resulting tarry residue was dissolved in ethanol and allowed to stand for several days to effect precipitation of crystals.

In this way, 18.9 g of crystals were obtained with a yield of 48.5%.

The thus-obtained compound represented by the following formula (1-4) showed a melting point of 1020C. When the crystals were dissolved in toluene and spotted on a piece of clay paper, bright orange color was formed. The thus-formed colored image showed its absorption maximum at 470 nm.

IR: VC=N 1590 cam~1, VC-H 2900 cm'l MS (m/e) : 390 (M+)

Example 5 20.7 Grams of N-methyl-2-phenylindole, 29.5 g of benzanilide and 30.6 g of phosphorus oxychloride were added to 50 cc of toluene, and the temperature of the mixture was increased to 1050C over 30 minutes. Subsequently, the reaction was carried out at the same temperature for 4.5 hours. After completion of the reaction, the reaction mixture was mixed with 100 cc of toluene and poured slowly into alkaline ice water.

After 1 hour of stirring at 600C, the toluene layer was collected, treated with carbon and then evaporated. The resulting tarry residue was dissolved in 125 cc of ethanol and subjected to crystallization to obtain 30.2 g of light yellow crystals with a yield of 78.2%.

The thus-obtained compound represented by the following formula (1-5) showed a melting point of 143.50C. When the crystals were dissolved in toluene and spotted on a piece of clay paper, bright yellow color was formed. The thus-formed colored image showed its absorption maximum at 430 nm.

IR: VC=N 1590 cm'l, VC-H 2920 cm'l MS (m/e): 386 (M+) 1H-NMR (CDC13/TMS, 3, ppm): 3.5 (s, 3 H), 7.1 (m, 19 H)

Example 6 29.6 Grams of benzanilide, 25.9 g of N-benzyldiphenylamine and 30.6 g of phosphorus oxychloride were added to 30 cc of toluene, and the temperature of the mixture was increased to 1100C over 30 minutes. Subsequently, the reaction was carried out at the same temperature for 4 hours. After completion of the reaction, the reaction mixture was mixed with 100 cc of toluene and poured slowly into alkaline ice water. After 30 minutes of stirring at 600C, the toluene layer was collected, treated with carbon and then evaporated. The resulting tarry residue was dissolved in 150 cc of ethanol and subjected to crystallization to obtain 22.8 g of white crystals with a yield of 52.1%.

The thus-obtained compound represented by the following formula (1-6) showed a melting point of 1450C. When the crystals were dissolved in toluene and spotted on a piece of clay paper, bright orange color was formed. The thus-formed colored image showed its absorption maximum at 470 nm.

IR: VC=N 1590 cm'l, VC-H 2910 cm-l MS (m/e): 438 (M+) 1H-NMR (CDC13/TMS, 6, ppm): 5.0 (s, 2 H), 7.1 (m, 24 H)

Example7 19.5 Grams of N-ethylcarbazole and 34.1 g of 4methoxybenzanilide were added to 60 cc of toluene, to which was added dropwise 30.7 g of phosphorus oxychloride, and the temperature of the resulting mixture was increased to 1000C over 30 minutes. Subsequently, the reaction was carried out at 100 to 1050C for 4 hours. After completion of the reaction, the reaction mixture was mixed with 50 cc of toluene and poured into 500 cc of ice water. After 30 minutes of stirring at 700C, this was treated with carbon and then evaporated. The resulting tarry residue was dissolved in 100 cc of methanol and subjected to crystallization to obtain 26.6 g of white crystals with a yield of 65.8%.

The thus-obtained compound represented by the following formula (1-7) showed a melting point of 1770C. When this compound was dissolved in toluene and spotted on a piece of clay paper, bright yellow color was formed. The thus-formed colored image showed its absorption maximum at 440 nm.

IR: VC=N 1595 cam~1, VC-H 2890 cm'l MS (m/e) : 404 (M+)

Example 8 A compound represented by the following formula (1-8) was obtained by repeating the procedure of Example 7 except that 4methoxybenzanilide of Example 7 was replaced by benzanilide.

This compound showed a melting point of 1320C. When this compound was dissolved in toluene and spotted on a piece of clay paper, bright yellow color was formed. The thus-formed colored image showed its absorption maximum at 430 nm.

Examples 9 to 40 Compounds (1-9) to (1-40) shown in the following tables were obtained in accordance with the aforementioned examples.

Melting points (M.P.), hues of colors developed on silica gel or clay (silica gel unless otherwise noted) and xmax on silica gel of these compounds are also shown in the table.

Table 1

Comp. Symbols in qeneral formula (1) M.P. Xmax (nm) No. (R)n R1 m R2 R3 R4 ( C) hue 1- 9 n = 0 m = 0 -C4H9 phenyl -H oil 440 orange 1-10 n=0 m=0 -C2H5 p-methyl -OC2H5 oil 430 phenyl orange 1-11 n= 0 m= 0 -CH3 p-methoxy -H 138 440 phenyl orange (clay) 1-12 n = 0 m = 0 -C2H5 p-ethoxy -H 129 445 phenyl orange (clav) 1-13 n = 0 m = 0 -C2H5 p-benzyl -H 154 445 oxyphenyl orange (clay) 1-14 4-OCH3 m = O -CH3 p-methoxy -H oil 450 phenyl orange ( clay 1-15 4-CH3 m = 0 -OH3 p-methoxy -H 117 440 phenyl orange (clav) 1-16 n = 0 m = 0 benzyl benzyl -H oil 435 orange 1-17 n = 0 4-CH3 -CH3 p-methoxy -H oil 440 phenyl orange 1-18 n = 0 4-OCH3 -CH3 p-methoxy -H oil 450 phenyl orange 1-19 -OCH3 4-CH3 form pyrrolidine -H 142 445 ring with orange adjacent N atom Table 1 (continued)

Comp. Symbols in general formula (1) M.P. #max (nm) No. (R)n (R)m R R R4 ( C) hue orange 1-21 n = 0 m = 0 -C2H5 -C2H5 -oC2H5 oil 420 orange 1-22 n = 0 m = 0 -C2H5 -C2H5 -CH3 oil 460 orange 1-23 n = 0 4-OCH3 benzyl phenyl -H 100 440 orange 1-24 n = 0 4-CH3 benzyl phenyl -H 129 440 orange 1-25 n = 0 2,4- benzyl phenyl -H oil 440 CH3 oranqe 1-26 4-OCH3 m = 0 benzyl phenyl -H 114 440 oranqe 1-27 4-CH3 m = 0 benzyl phenyl -H 97 450 orange 1-28 n = 0 m = 0 -C8H17 phenyl -H oil 430 orange 1-29 4-OCH3 m = 0 -CH3 phenyl -H oil 430 orange 1-30 n = 0 m = 0 -C2H5 p-methyl -OC4H9 oil 430 phenyl orange 1-31 4-OCH3 m = 0 -C2H5 p-methyl -OC2H5 oil 430 1-32 4-CH3 m = O -CH3 phenyl -H oil 430 orange Table 1 (continued)

Comp. S mbols in general formula (1) M.P. #max (nm) No. (R)n R1 m R2 R3 R4 0C hue 1-33 n = 0 2,6- -C2H5 benzyl -H 133 420 CH3 oranqe 1-34 n = 0 2,6- benzyl phenyl -H oil 420 CH3 orange 1-35 n = 0 2,6- -C2H5 benzyl -H oil 420 C2H5 orange 1-36 n = 0 4-tert -C2H5 benzyl -H oil 430 -C4Hg oranqe 1-37 n = 0 2, 6- -C2H5 p-ethoxy -H 98 420 CH3 phenyl orange 1-38 n = 0 2-CH3 -C2H5 p-ethoxy -H 83 420 phenyl oranqe 1-39 n = 0 2,6- -C2H5 p-ethoxy -H 107 420 C2H5 phenyl orange 1-40 n = 0 2,6- -CH3 p-methoxy -H 101 420 C2H hen 1 orange Example 41 (Production of pressure sensitive recording paper) 10.0 Parts (the term "parts" as used herein means weight parts) of the compound (1-1) obtained in Example 1 was dissolved in 90 parts of KMC-113 (an alkylnaphthalene base solvent for pressure sensitive copy paper, manufactured by Kureha Chemical Industry), to which was added a solution prepared by dissolving 24 parts of gelatin and 24 parts of gum arabic in 400 parts of water and adjusting the pH value to 7. The resulting mixture was emulsified using a homogenizer, mixed with 1,000 parts of hot water, stirred at 500C for 30 minutes, mixed with about 1 part of 10% sodium hydroxide solution and again stirred at 500C for 30 minutes. After adjusting to pH 4.5 by gradual addition of dilute acetic acid, the mixture was stirred at 500C for about 1 hour, cooled to 0 to 50C and then stirred for 30 minutes.

Next, to this was gradually added 35 parts of 4% glutaraldehyde aqueous solution to harden capsules, followed by the adjustment of its pH value to 6 with sodium hydroxide aqueous solution and subsequent several hours of stirring at room temperature to complete capsulation. The thus-prepared capsule solution was uniformly coated on a sheet of paper using a wire bar and then dried to obtain coated paper (upper paper).

When this was superposed upon a sheet of paper (lower paper) coated with zinc 3,5-di(a-methylbenzyl)salicylate as a color developer, and a pressure of a ball-point pen or an impact of a typewriter was added to the laminate, an image of dense orange color was immediately formed on the lower paper.

When this colored image was exposed to sunlight for 5 hours, it showed markedly strong light resistance.

Example 42 An image of orange color was obtained by repeating the procedure of Example 41, except that the compound (1-2) obtained in Example 2 was used instead of the compound (1-1) obtained in Example 1.

Example 43 An image of orange color was obtained by repeating the procedure of Example 41, except that the compound (1-4) obtained in Example 4 was used instead of the compound (1-1) obtained in Example 1.

Example 44 An image of orange color was obtained by repeating the procedure of Example 41, except that the compound (1-11) was used instead of the compound (1-1) obtained in Example 1.

Comparative Example 1 A colored image was obtained by repeating the procedure of Example 41, except that a compound (2-1) of the following formula was used instead of the compound (1-1) obtained in Example 1.

Comparative Example 2 ..A colored image was obtained by repeating the procedure of Example 41, except that a compound (2-2) of the following formula was used instead of the compound (1-1) obtained in Example 1.

Comparative Example 3 A colored image was obtained by repeating the procedure of Example 41, except that a compound (2-3) of the following formula was used instead of the compound (1-1) obtained in Example 1.

Initial density and residual ratio of each of the colored images developed on pressure sensitive recording paper obtained in Examples 41 to 44 and Comparative Examples 1 to 3 were measured, with the results shown in the following table.

The residual ratio of image was expressed by the ratio (%) of its density after 5 hours of exposure to a UV lamp to the initial density. The image density was measured using Macbeth RD-514 (manufactured by Macbeth).

Table 2

Initial density Residual ratio (%) Inventive Example 41 0.70 99 Inventive Example 42 0.81 99 Inventive Example 43 0.67 104 Inventive Example 44 0.72 98 Comparative Example 1 0.61 74 Comparative Example 2 0.74 64 Comparative Example 3 0.52 62 As is evident from the above table, the compound of the present invention is excellent both in initial density and light resistance.

Example 45 (Production of thermal recording paper) 1) Preparation of color coupler dispersion (A) compound (1-1) of Example 1 5 parts kaolin 15 parts 10% polyvinyl alcohol aqueous solution 100 parts water 85 parts These components were mixed and pulverized using a paint shaker until average particle size of the coupler became 2 microns.

2) Preparation of color developer dispersion (B) bisphenol A 15 parts zinc stearate 10 parts 10% polyvinyl alcohol aqueous solution 150 parts These components were mixed and pulverized using a paint shaker until average particle size became 3 microns.

3) Preparation of thermal coating solution and coating A thermal coating solution was obtained by mixing and stirring 10 parts of the dispersion A and 6.5 parts of the dispersion B. The thus-prepared coating solution was uniformly applied to a sheet of paper using a wire bar in such an amount that the coat layer contained 8 g/m2 when dried, thereby obtaining a sheet of thermal recording paper.

This thermal recording paper caused no surface fogging, was almost colorless and quickly developed a dense orange image by thermal head printing. The thus-formed colored image was excellent in light resistance and moisture resistance. The coated surface was also excellent in light resistance and did not cause coloring or reduction of color developing ability when exposed to daylight.

[Effect of the Invention] The present invention provides a novel phenylimine compound which is useful as a color coupler of yellow/orange system.

Claims (3)

Claims

1. A phenylimine compound represented by the following general formula (1)

wherein R represents a lower alkyl group, a lower alkoxy group or a dialkylamino group, R1 represents a lower alkyl group or a lower alkoxy group, each of n and m is an integer of 0, 1 or 2 and Y is a group represented by any one of the following formulae (2), (3) and (4):

wherein each of R2 and R3 independently represents a lower alkyl group, a benzyl group or a phenyl group which may be substituted, or R2 and R3 together with the nitrogen atom to which they are attached form a pyrrolidine ring, R4 represents a hydrogen atom, a lower alkyl group or a lower alkoxy group, R5 represents a hydrogen atom or a lower alkyl group, R6 represents a hydrogen atom, a lower alkyl group or a phenyl group and R7 represents a hydrogen atom or a lower alkyl group.

2. A phenylimine compound as claimed in claim 1 substantially as hereinbefore described.

3. A recording material comprising a phenylimine compound as claimed in claim 1 or 2 as a color coupler.