# Patent

## Title
Novel optically active alcohol

## Abstract

Disclosed herein are novel divinyl compounds represented by the formula (I): ##STR1## and a recording-material prepared by utilizing the divinyl compounds. The divinyl compound is in itself almost colorless, extremely stable in the atmosphere and develops rapidly blackish color by a developer. The color image given by the divinyl compound is excellent in light-resistance and moisture-resistance and the letters developed can be read by an optical letter-reading apparatus or a barcord reading apparatus.

## Background
The present invention relates to a recording-material such as pressure-sensitive recording paper, heat-sensitive recording paper, electro-heat sensitive recording paper, etc. More in detail, the present invention relates to a recording-material prepared by using a divinyl phthalide compound represented by the formula (I): ##STR2## wherein X.sup.1 represents an alkyl group, an alkoxy group or a halogen atom; X.sup.2 represents an alkyl group, an alkoxy group, a halogen atom or a group of R.sup.3 O--; X.sup.3 represents a halogen atom; R.sup.1 represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, a haloalkyl group, an alkyenyl group, an aralkyl group, a cyclohexylmethyl group, a methylcyclohexyl group, a trimethylcyclohexyl group, a furfuryl group, a tetrahydrofuryl group or a tetrahydropyrane-2-yl-methyl group; R.sup.2 represents a cycloalkyl group, a phenyl group or a benzyl group having chlorine atom(s), bromine atom(s) or alkyl group(s) of not more than 4 carbon atoms as the substituent, or optional group R.sup.1 ; R.sup.3 represents a cycloalkyl group, an alkoxyalkyl group, an alkenyl group, a haloalkyl group, an aralkyl group or an aryl group; and m and n represent an integer of 0, 1, 2 or 3, respectively. When m and n are not less than 2, X.sup.1 of (X.sup.1).sub.m, X.sup.2 of (X.sup.2).sub.n or X.sup.3 of (X.sup.3).sub.4 can be same or different. (Hereinafter the same sign means the same meaning).

The divinyl phthalide compounds represented by the formula (I) are the novel compounds synthesized for the first time by the present inventors. The compounds are by themselves almost colorless, extremely stable in the atmosphere, have no subliming property and spontaneously chlomogenic property and dissolve extremely well in organic solvents. They give a blackish color rapidly by a developer and its color image is excellent in light-resistance and moisture-resistance. Furthermore, since the color image has a strong absorption between 700 and 1000 nm in addition of the visible region, the color image has a distinctive feature that it is possible to be read by the optical letter-reading apparatus using the near infrared rays (such as OCR and OMR) and the barcord reading apparatus. Namely, the divinyl phthalide compound of the present invention (hereinafter referred to as the present compound) is an extremely valuable and novel compound which can be used as a chromogenic agent for an ordinary recording-material developing black color, of which demand is rapidly increasing recently, as well as the material readable with OCR, OMR, etc.

The color image due to the black-coloring fluoran compound (A), which has been used as a conventional chromogenic agent for a recording-material, does not have any absorption in the near infrared region and accordingly, the color image could not be read by an optical letter-reading apparatus (refer to FIG. 2): ##STR3## (refer to Japanese Patent Publication No. 56-52759/1981).

On the other hand, as the chromogenic agents having an absorption in the near infrared region, some compounds have been recently proposed in Japanese Patent Publication No. 58-5940/1983, Japanese Patent Application Laid-Open (KOKAI) No. 59-199757/1984 and Japanese Patent Application Laid-Open (KOKAI) No. 60-230890/1985. However, each of the proposed compounds has the following defects and any satisfactory chromogenic agent has not been obtained in the present situation.

Namely, the compound (B) of Japanese Patent Publication No. 58-5940/1983 and the compound (C) of Japanese Patent Application Laid-Open (KOKAI) No. 60-230890/1985 have been themselves strongly colored in yellow and besides, they are strong in the spontaneous coloring. These defects have very had effect on production of the recording materials.

Although the fluorene compound (D) of Japanese Patent Application Laid-Open (KOKAI) No. 59-199757/1984 is colorless, the chromogenic property and the stability of color image are poor.

Furthermore, the hue of each of compounds (B), (C) and (D), when developed color, is green and accordingly, to obtain blackish color, another chromogenic agent giving red or black color must be added in a large amount, and since the chromogenic property and the chromogenic speed of each agent are different from those of compounds (B), (C) and (D) and particularly, the light-resistance of red-chromogenic agent is generally poor, bad influences such as unbalance of color-development and reduction of light-resistance could not be avoided. ##STR4## (refer to Japanese Patent Publication No. 58-5940/1983). ##STR5## (refer to Japanese Patent Application Laid-Open (KOKAI) No. 60-230890/1985). ##STR6## (refer to Japanese Patent Application Laid-Open (KOKAI) No. 59-199757/1984).

As a result of the present inventors earnest studies to improve the defects of the conventional chromogenic agents, the present invention has been attained.

The present invention has been attained by the present inventors who have found out that the divinyl compounds (I) are unexpectedly excellent in several properties such as the solubility, the coloring of the compound itself, the hue of the developed color, the chromogenic property, the absorbancy of near infrared rays and the stability of color image and have studied further the problems, and the present invention provides the compounds represented by the formula (I) and a chromogenic recording materials, which contains the compound (I) as a chromogenic agent.

The object of the present invention lies in offering a novel divinyl compound represented by the following formula (I): ##STR7##

Furthermore, the object of the present invention lies in offering a chromogenic dye-precursor material of blackish color represented by the formula (I).

Still more, the object of the present invention lies in offering a recording-material comprising a material containing the divinyl compound represented by the formula (I) as a chromogenic agent.

Of the attached drawings, FIGS. 1 and 2 are the reflection spectra of a color image of pressure-sensitive and heat-sensitive recording paper prepared with the present compound and the referenced compound, respectively, and

FIG. 3 is the reflection spectra of a texture of heat-sensitive recording paper prepared with the present compound and the referenced compound.

The present compound is a divinyl compound represented by the following formula (I): ##STR8## and as the concrete example thereof, the following compounds may be exemplified. Every compound is an almost colorless or pale yellow solid and develops a blue-black to black color rapidly by the action of activated clay. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7-tet rachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-ethoxyphenyl)-ethenyl]-4,5,6,7-tetr achlorophthalide 3,3-Bis[2-(p-diethylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7-tetr achlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-propoxyphenyl)-ethenyl]-4,5,6,7-tet rachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-isopropoxyphenyl)-ethenyl]-4,5,6,7- tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-butoxyphenyl)-ethenyl]-4,5,6,7-tetr achlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-isobutoxyphenyl)-ethenyl]-4,5,6,7-t etrachlorophthalide 3,3-Bis[2-(p-methylethylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7- tetrachlorophthalide 3,3-Bis[2-(p-methylpropylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7 -tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methylphenyl)-ethenyl]-4,5,6,7-tetr achlorophthalide 3,3-Bis[2-(p-ethylpropylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7- tetrachlorophthalide 3,3-Bis[2-(p-methylisopropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6 ,7-tetrachlorophthalide 3,3-Bis[2-(p-ethylisopropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6, 7-tetrachlorophthalide 3,3-Bis[2-(p-dipropylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7-tet rachlorophthalide 3,3-Bis[2-(p-methylbutylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-t etrachlorophthalide 3,3-Bis[2-(p-ethylbutylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7-t etrachlorophthalide 3,3-Bis[2-(p-diethylaminophenyl)-2-(p-ethoxyphenyl)-ethenyl]-4,5,6,7-tetra chlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m-methyl-p-methoxyphenyl)ethenyl]-4,5 ,6,7-tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-pentyloxyphenyl)-ethenyl]-4,5,6,7-t etrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7-tet rabromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-isopentyloxyphenyl)ethenyl]-4,5,6,7 -tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m,p-dimethoxyphenyl)ethenyl]-4,5,6,7- tetrachlorophthalide 3,3-Bis[2-(p-methylpropylaminophenyl)-2-(p-ethoxyphenyl)-ethenyl]-4,5,6,7- tetrachlorophthalide 3,3-Bis[2-(p-ethylpropylaminophenyl)-2-(p-ethoxyphenyl)-ethenyl]-4,5,6,7-t etrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-ethylphenyl)-ethenyl]-4,5,6,7-tetra chlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrachlorophth alide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-tert-butoxyphenyl)-ethenyl]-4,5,6,7 -tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-sec-butoxyphenyl)-ethenyl]-4,5,6,7- tetrachlorophthalide 3,3-Bis[2-(p-dimethylcyclohexylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4, 5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-5,6-dichlor o-4,7-dibromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m,p-dimethylphenyl)-ethenyl]-4,5,6,7- tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(o-methyl-p-methoxyphenyl)ethenyl]-4,5 ,6,7-tetrachlorophthalide 3,3-Bis[2-(p-dimethylamino-o-methylphenyl)-2-phenylethenyl]-4,5,6,7-tetrac hlorophthalide 3,3-Bis[2-(p-dimethylamino-o-chlorophenyl)-2-(p-methylphenyl)ethenyl]-4,5, 6,7-tetrachlorophthalide 3,3-Bis[2-(p-dimethylamino-m-methylphenyl)-2-(p-methoxyphenyl)ethenyl]-4,5 ,6,7-tetrachlorophthalide 3,3-Bis[2-(p-dimethylamino-o-ethylphenyl)-2-(p-methoxyphenyl)ethenyl]-4,5, 6,7-tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-chlorophenyl)-ethenyl]-4,5,6,7-tetr achlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(o,p-dimethoxyphenyl)-ethenyl]-4,5,6,7 -tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m-methoxyphenyl)-ethenyl]-4,5,6,7-tet rachlorophthalide 3,3-Bis[2-(p-dipropylaminophenyl)-2-(p-methylphenyl)-ethenyl]-4,5,6,7-tetr achlorophthalide 3,3-Bis[2-(p-dibutylamino-o-methylphenyl)-2-(p-methoxyphenyl)ethenyl]-4,5, 6,7-tetrachlorophthalide 3,3-Bis[2-(p-dihexylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrachlorophtha lide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-octylphenyl)-ethenyl]-4,5,6,7-tetra chlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-hexyloxyphenyl)-ethenyl]-4,5,6,7-te trachlorophthalide 3,3-Bis[2-(p-methylcyclohexylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6 ,7-tetrachlorophthalide 3,3-Bis[2-(p-ethylbenzylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7- tetrachlorophthalide 3,3-Bis[2-(p-ethyltolylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrachloroph thalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrabromophtha lide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-fluorophenyl)-ethenyl]-4,5,6,7-tetr abromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-chlorophenyl)-ethenyl]-4,5,6,7-tetr abromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m,p-dimethoxyphenyl)ethenyl]-4,5,6,7- tetrabromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m,p-dimethylphenyl)ethenyl]-4,5,6,7-t etrabromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-5-chloro-4,6,7-tribromo phthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m-methylphenyl)-ethenyl]-5-chloro-4,6 ,7-tribromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-hexyloxyphenyl)-ethenyl]-5-chloro-4 ,6,7-tribromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-6-chloro-4,5,7-tribromo phthalide 3,3-Bis[2-(p-dimethylamino-o-chlorophenyl)-2-(p-methylphenyl)ethenyl]-6-ch loro-4,5,7-tribromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-6-chloro-4, 5,7-tribromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-5,6-dichloro-4,7-dibrom ophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m-methyl-p-methoxyphenyl)ethenyl]-5,6 -dichloro-4,7-dibromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m-methoxyphenyl)-ethenyl]-5,6-dichlor o-4,7-dibromophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-butoxyphenyl)-ethenyl]-4,5,6,7-tetr abromophenylphthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-hexyloxyphenyl)-ethenyl]-4,5,6,7-te trabromophthalide 3,3-Bis[2-(p-dimethylamino-o-methylphenyl)-2-(p-methylphenyl)ethenyl]-4,5, 6,7-tetrabromophthalide 3,3-Bis[2-(p-dimethylamino-m-methylphenyl)-2-(p-methoxyphenyl)ethenyl]-4,5 ,6,7-tetrabromophthalide 3,3-Bis[2-(p-dimethylamino-m-ethoxyphenyl)-2-phenylethenyl]-4,5,6,7-tetrab romophthalide 3,3-Bis[2-(p-diethylaminophenyl)-2-(p-methylphenyl)-ethenyl]-4,5,6,7-tetra bromophthalide 3,3-Bis[2-(p-dipropylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7-tet rabromophthalide 3,3-Bis[2-(p-dibutylaminophenyl)-2-(p-methylphenyl)-ethenyl]-4,5,6,7-tetra bromophthalide 3,3-Bis[2-(p-dihexylaminophenyl)-2-(p-methylphenyl)-ethenyl]-4,5,6,7-tetra bromophthalide 3,3-Bis[2-(p-methylbutylaminophenyl)-2-(p-methylphenyl)-ethenyl]-4,5,6,7-t etrabromophthalide 3,3-Bis[2-(p-methylcyclohexylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5, 6,7-tetrabromophthalide 3,3-Bis[2-(p-ethylbenzylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrabromoph thalide 3,3-Bis[2-(p-ethyltolylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7-t etrabromophthalide 3,3-Bis[2-(p-aminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorop hthalide 3,3-Bis[2-(p-ethylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7-tetrac hlorophthalide 3,3-Bis[2-(p-methylmethoxyethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4, 5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-methylethoxypropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4, 5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-dimethoxyethylaminophenyl)-2-(p-methylphenyl)ethenyl]-5-chlor o-4,6,7-tribromophthalide 3,3-Bis[2-(p-benzylmethoxypropylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4, 5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-cyclohexylethoxyethylaminophenyl)-2-phenylethenyl]-5,6-dichlo ro-4,7-dibromophthalide 3,3-Bis[2-(p-methylmethoxyethylaminophenyl)-2-(p-chlorophenyl)ethenyl]-4,5 ,6,7-tetrachlorophthalide 3,3-Bis[2-(p-ethylmethoxyethylamino-m-methylphenyl)-2-(p-methoxyphenyl)eth enyl]-4,5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-methylethoxypropylamino-m-ethoxyphenyl)-2-(p-methoxyphenyl)et henyl]-4,5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-methylallylaminophenyl)-2-(p-methylphenyl)-ethenyl]-4,5,6,7-t etrachlorophthalide 3,3-Bis[2-(p-diallylaminophenyl)-2-(p-methoxyphenyl)-ethenyl]-4,5,6,7-tetr achlorophthalide 3,3-Bis[2-(p-ethyl-.gamma.-chloropropylaminophenyl)-2-(m,p-dimethoxyphenyl )ethenyl]-4,5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-di-.gamma.-chloropropylaminophenyl)-2-(p-ethoxyphenyl)ethenyl ]-4,5,6,7-tetrabromophthalide 3,3-Bis[2-(p-cyclopentyl-.gamma.-chloropropylaminophenyl)-2-(p-butoxypheny l)ethenyl]-4,5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-methylcyclohexylmethylaminophenyl)-2-(p-methoxy-m-methylpheny l)ethenyl]-4,5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-ethyl-4-methylcyclohexylaminophenyl)-2-phenylethenyl]-4,5,6,7 -tetrafluorophthalide 3,3-Bis[2-(p-methyl-3,3,5-trimethylcyclohexylaminophenyl)-2-(p-butylphenyl )ethenyl]-4,5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-4-methylbenzylmethoxypropylaminophenyl)-2-(m,p-dimethoxypheny l)ethenyl]-4,5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-ethylfurfurylaminophenyl)-2-(m,p-dimethylphenyl)ethenyl]-4,5, 6,7-tetrachlorophthalide 3,3-Bis[2-(p-methyltetrahydrofurfurylaminophenyl)-2-(p-methoxyphenyl)ethen yl]-4,5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-ditetrahydrofurfurylaminophenyl)-2-(m-methyl-p-methoxyphenyl) ethenyl]-4,5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-benzyltetrahydrofurfurylaminophenyl)-2-(p-methoxyphenyl)ethen yl]-5-chloro-4,6,7-tribromophthalide 3,3-Bis[2-(p-methyltetrahydropyrane-2-yl-methylaminophenyl)-2-(p-methoxyph enyl)ethenyl]-4,5,6,7-tetrachlorophthalide 3,3-Bis[2-(p-methylmethoxyethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4, 5,6,7-tetrafluorophthalide 3,3-Bis[2-(p-methylethoxypropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4, 5,6,7-tetrafluorophthalide 3,3-Bis[2-(p-dimethoxyethylaminophenyl)-2-(p-methylphenyl)ethenyl]-5-chlor o-4,6,7-triiodophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methoxyethoxyphenyl)ethenyl]-4,5,6, 7-tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-allyloxyphenyl)-ethenyl]-4,5,6,7-te trachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-chloropropyloxyphenyl)ethenyl]-4,5, 6,7-tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-cyclolpentyloxyphenyl)ethenyl]-4,5, 6,7-tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-cyclohexyloxyphenyl)ethenyl]-4,5,6, 7-tetrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-benzyloxyphenyl)-ethenyl]-4,5,6,7-t etrachlorophthalide 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-phenoxyphenyl)-ethenyl]-4,5,6,7-tet rachlorophthalide 3,3-Bis{2-[p-dimethylaminophenyl]-2-[p-methoxyphenoxy)-phenyl]ethenyl}-4,5 ,6,7-tetrachlorophthalide 3,3-Bis{2-[p-diethylaminophenyl]-2-[p-methoxyphenoxy)-phenyl]ethenyl}-4,5, 6,7-tetrachlorophthalide

The divinylphthalide compounds according to the present invention can be synthesized by the method shown below.

As a first step, an ethylene derivative represented by the formula (2) is synthesized from a ketone by one of the following Grignard reactions a, b and c: ##STR9## wherein X represents a halogen atom.

Then, 2 mols of an ethylene derivative (2) and 1 mol of a phthalic acid derivative (3) are condensated in the presence of a dehydrating agent such as acetic anhydride, sulfuric acid, etc., and by purifying the reaction product, the divinylphthalide compounds represented by the formula (I) are obtained as nearly colorless crystals. ##STR10##

As the concrete examples of the ethylene derivative represented by the formula (2), the following compounds can be exemplified: 1-(m,p-dimethylphenyl)-1-(p-propyl-.gamma.-chloropropylaminophenyl)ethylen e 1-(m,p-dimethoxyphenyl)-1-(p-cyclohexyl-.gamma.-chloropropylaminophenyl)et hylene 1-(p-methoxyphenyl)-1-[p-methyl-(3-methylcyclohexy)-aminophenyl]ethylene 1-(p-ethoxy-m-methylphenyl)-1-[p-ethyl-(3,3,5-trimethylcyclohexyl)aminophe nyl]ethylene 1-(m-methyl-p-ethoxyphenyl)-1-(p-ethyltetrahydropyrane-2-yl-methylaminophe nyl)ethylene 1-(p-methoxyphenyl)-1-(p-ditetrahydropyrane-2-yl-methylaminophenyl)ethylen e

As phthalic acid derivatives represented by the formula (3), for instance, the following compounds can be mentioned:

Tetrachlorophthalic anhydride; 4-chloro-3,5,6-tribromophthalic anhydride; 4,5-dichloro-3,6-dibromophthalic anhydride; 4-bromo-3,5,6-trichlorophthalic anhydride; 4,5-dibromo-3,6-dichlorophthalic anhydride; tetrabromophthalic anhydride; tetrafluorophthalic anhydride; tetraiodophthalic anhydride; 4,5-dichloro-3,6-difluorophthalic anhydride; 4-chloro-3,5,6-triiodophthalic anhydride and 4,5-dichloro-3,6-diiodophthalic anhydride.

In case where a pressure-sensitive recording paper, a heat-sensitive recording paper, etc. is produced with these divinylphthalide compounds, one or more of the compounds, can be used. By mixing not less than two of the compounds, the chromogenic property and the stability in preserving the color image are improved. Moreover, to make the hue and the concentration of developed color, and the stability of color image more complete, various known chromogenic agents which give various hues can be used with the present compound to the extent not to damage the facilities of the present compound.

For instance, the present compound can be used with the chromogenic agent which has the fundamental skeleton such as 3,3-bis(aminophenyl)-6-aminophthalide, 3,3-bis(indolyl)phthalide, 3-aminofluoran, aminobenzofluoran, 2,6-diaminofluoran, 2,6-diamino-3-methylfluoran, spiropyrane, phenothiazine, phenoxazine, leucoauramine, diarylcarbazolylmethane, 3-indolyl-3-(aminophenyl)azaphthalide, triaminofluorenephthalide, tetraaminodivinylphthalide.

When producing a pressure-sensitive recording paper, as a solvent for a chromogenic agent, various solvents of alkylbenzene series, alkylbiphenyl series, alkylnaphthalene series, diarylethane series, hydrogenated terphenyl series and chlorinated paraffin series can be used singly or as a mixture, and for encapsulation, a coacervation method, a interfacial polymerization method or an In-situ method can be applied.

As a developer, clays such as bentonite, activated clay, acid clay, etc.; metal salt of salicyclic acid, salicyclic ester derivatives, salicyclic acid derivatives, etc.; hydroxy compounds such as 2,2-bis(p-hydroxyphenyl)propane (bisphenol A), esters of p-hydroxybenzoic acid, etc.; p-phenylphenol-formaldehyde resin, p-octylphenolformaldehyde resin and metal salt thereof, are used.

When producing a heat-sensitive recording paper, as a binder, polyvinyl alcohol, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, gum arabic, gelatine, caseine, starch, polyvinyl pyrrolidone, copolymer of styrene and maleic anhydride, can be used.

As a developer, one or more of the following hydroxy compounds can be used: p-phenylphenol, p-hydroxydiphenyl ether, methyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, 2,2-bis(p-hydroxyphenyl)-propane, 4,4'-thiodiphenol, bis(4-hydroxy-3-methylphenyl)-sulfide, 4,4'-dihydroxydiphenylsulfone, 4-hydroxy-4'-methyldiphenylsulfone, 4-hydroxy-4'-ethyldiphenylsulfone, 3,4-dihydroxy-4'-methyldiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone, 4,4'-dihydroxy-3,3'-diallyldiphenylsulfone, 1,5-di(4-hydroxyphenylthio)-3-oxapentane, 1,7-di(4-hydroxyphenylthio)-3,5-dioxaheptane, 1,8-di(4-hydroxyphenylthio)-3,6-dioxaoctane, bis(4-hydroxy-3-methylphenyl)sulfide, etc.

As a sensitivity-improving agent, acetoanilide; paraffin wax; carnauba wax; higher fatty acids; esters of a higher fatty acid; amides of a higher fatty acid; phthalic esters; terephthalic esters; benzyl 4-benzyloxybenzoate; naphthol benzyl ether; 1,4-dialkoxynaphthalene; m-terphenyl; p-benzylbiphenyl; dibenzylbenzene; esters of 1-hydroxy-2-naphthoic acid; 1-phenoxy-2-naphthoxy-1-ethane; 1,2-di(3-methylphenoxy)ethane; 1-(2-isopropylphenoxy)-2-naphthoxy-2-ethane; esters of 2-hydroxy-3-naphthoic acid; 4,4'-dialkoxydiphenylsulfone; benzamide; diphenylamine; benzenesulfonamide; benzenesulfonanilide; carbazole; hydroquinone dibenzyl ether; diphenyl carbonate, etc. can be used singly or after mixing together.

Furthermore, in order to improve the light-resistance and the preservability of the color image, it is effective to add an anti-oxidant, an anti-deteriorant or an ultraviolet absorbent, or to overcoat a high polymeric substance.

The present invention will be concretely explained while referring to the Synthetic Examples of the compound represented by the formula (I) and the Production Examples of the chromogenic recording-material with the compound represented by the formula (I) as follow. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetr achlorophthalide

Into 25 ml of acetic anhydride, 13.0 g of 1-(p-methoxyphenyl)-1-(p-dimethylaminophenyl)ethylene and 9.3 g of tetrachlorophthalic anhydride were added and the mixture was stirred for 2 hours at 120.degree. C. After adding the reaction mixture into 200 ml of water and making the mixture alkaline with sodium hydroxide, the alkaline mixture was extracted with 70 ml of toluene. The solid matter obtained by distilling off toluene from the extract was recrystallized from butanol while purifying with activated carbon to obtain 14.3 g of pale yellow crystals melting at 133.degree.-135.degree. C.

By the elementary analysis, the infrared absorption spectrum and the nuclear magnetic resonance spectrum of the crystals obtained, it was confirmed that the crystals was the object compound represented by the following formula: ##STR11##

This compound rapidly colored blue-black by activated clay and the .lambda.max in methanol.multidot.stannic chloride was 890 nm.

The ethylene derivative, 1-(p-methoxyphenyl)-1-(p-dimethylaminophenyl)ethylene, used in the above reaction, was synthesized as follows.

Into 30 ml of ether, 4 g of metallic magnesium were added and then 0.2 ml of methyl iodide was added to the mixture. After stirring the mixture for a while, a solution prepared by dissolving 24.8 g of methyl iodide into 40 ml of ether was added to the mixture taking 2 hours under a reflux condenser while stirring the mixture.

Separately, a solution was prepared by mixing 18.2 g of 4-methoxy-4'-dimethylaminobenzophenone (melting at 126.degree.-127.degree. C.) and 100 ml of tetrahydrofurane, and the solution was slowly added to the liquid reaction mixture and the whole matter was stirred for one hour at a temperature of 40.degree. to 50.degree. C. Then the whole matter was mixed with 400 ml of water and 300 ml of toluene and after making the mixture weakly acidic by dilute hydrochloric acid, the acidified mixture was stirred for a whole at 80.degree. C. and separated into an aqueous layer and an organic layer (toluene layer). After adding activated carbon to the toluene layer and filtering the layer while hot, toluene was distilled off from the filtrate to obtain 17.1 g of 1-(p-methoxyphenyl)-1-(p-dimethylaminophenyl)ethylene of pale yellow in color, melting at 123.degree.-125.degree. C. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetra chlorophthalide

Into a mixture of 25 ml of acetic anhydride and 75 ml of o-dichlorobenzene, 13.4 g of 1-(p-ethoxyphenyl)-1-(p-dimethylaminophenyl)ethylene (melting at 110.degree.-111.degree. C.) and 21.5 g of tetrachlorophthalic anhydride were added and the mixture was stirred for 6 hours at 120.degree. C. After adding the reaction mixture into 200 ml of water and making the mixture alkaline by sodium hydroxide, the alkaline mixture was extracted with 70 ml of toluene. The solid matter obtained by distilling off toluene from the extract was recrystallized from acetone while purifying with activated carbon to obtain 16.2 g of pale yellow crystals in a yield of 80.8%.

The obtained compound melted at 168.degree.-170.degree. C., and from the elementary analysis, the infrared absorption spectrum and the nuclear magnetic resonance spectrum of this compound, it was confirmed that the substance was the object compound represented by the following formula: ##STR12##

This compound rapidly colored blue-black by activated clay and .lambda.max of this compound in methanol.multidot.stannic chloride was 882 nm.

By bringing various ethylene derivatives into reaction with various phthalic acid derivatives in the same manner as in Synthetic Examples 1, 2 and 3, the divinyl compounds shown in Table 1 were synthesized. All the compounds were solid and colorless to pale yellow in color. They were colored rapidly into the hue shown in Table 1.

For preparing a pressure-sensitive recording paper with the divinyl-compound represented by the formula (I), any publicly known method can be used, for instance, the coacervation method disclosed in U.S. Pat. Nos. 2,800,458 and 2,806,457. For preparing the heat-sensitive recording paper, a publicly known method, for instance, the method disclosed in Japanese Patent Publication No. 45-14039/1960, can be used. Compound No. R.sup.1 R.sup.2 X.sup.1 X.sup.2 X.sup.3 Color .lambda.max (nm) M.P. (.degree.C.) 3 C.sub.2 H.sub.5 C.sub.2 H.sub.5 -- p-CH.sub.3 O Cl Blue black 900 95 (m = 0)     (decomposition) 4 CH.sub.3 CH.sub.3 -- p-n-C.sub.3 H.sub.7 O Cl Blue black 888 162-164    (m = 0) 5 CH.sub.3 CH.sub.3 -- p-i-C.sub.3 H.sub.7 O Cl Blue black 883 129-132    (m = 0) 6 CH.sub.3 CH.sub.3 -- p-n-C.sub.4 H.sub.9 O Cl Blue black 885 180-183    (m = 0) 7 CH.sub.3 CH.sub.3 -- p-i-C.sub.4 H.sub.9 O Cl Blue black 885 179-182 (m = 0) 8 CH.sub.3 C.sub.2 H.sub.5 -- p-CH.sub.3 O Cl Blue black 892 120 (m = 0)     (decomposition) 9 CH.sub.3 C.sub.3 H.sub.7 -- p-CH.sub.3 O Cl Blue black 895 Difficult to    (m = 0)     crystallize 10 CH.sub.3 CH.sub.3 -- p-CH.sub.3 Cl Black 900 215-218    (m = 0) 11 C.sub.2 H.sub.5 C.sub.3 H.sub.7 -- p-CH.sub.3 O Cl Blue Black 895 115-118    (m = 0) 12 CH.sub.3 i-C.sub.3 H.sub.7 -- p-CH.sub.3 O Cl Blue black 895 Difficult to    (m = 0)     crystallize 13 C.sub.2 H.sub.5 i-C.sub.3 H.sub.7 -- p-CH.sub.3 O Cl Blue black 895 136-139    (m = 0) 14 C.sub.3 H.sub.7 C.sub.3 H.sub.7 -- p-CH.sub.3 O Cl Blue black 897 Difficult to (m = 0)     crystallize 15 CH.sub.3 C.sub.4 H.sub.9 -- p-CH.sub.3 O Cl Blue black 895 105-108    (m = 0) 16 C.sub.2 H.sub.5 C.sub.4 H.sub.9 -- p-CH.sub.3 O Cl Blue black 892 Difficult to    (m = 0)     crystallize 17 C.sub.2 H.sub.5 C.sub.2 H.sub.5 -- p-C.sub.2 H.sub.5 O Cl Blue black 895 125-128    (m = 0) 18 CH.sub.3 CH.sub.3 -- p-CH.sub.3 O, m-CH.sub.3 Cl Blue black 882 131-135    (m = 0) 19 CH.sub.3 CH.sub.3 -- p-n-C.sub.5 H.sub.11 O Cl Blue black 882 Difficult to    (m = 0)     crystallize 20 CH.sub.3 CH.sub.3 -- p-CH.sub.3 O Br Blue black 900 133-135    (m = 0) 21 CH.sub.3 CH.sub.3 -- p-i-C.sub.5 H.sub.11 O Cl Blue black 880 125-128 (m = 0) 22 CH.sub.3 CH.sub.3 -- p-CH.sub.3 O, m-CH.sub.3 O Cl Blue black 890 208-211    (m = 0) 23 CH.sub.3 C.sub.2 H.sub.5 -- p-C.sub.2 H.sub.5 O Cl Blue black 890 138-141    (m = 0) 24 CH.sub.3 C.sub.3 H.sub.7 -- p-C.sub.2 H.sub.5 O Cl Blue black 890 118-121    (m = 0) 25 CH.sub.3 CH.sub.3 -- p-C.sub.2 H.sub.5 Cl Black 900 185-188    (m = 0) 26 CH.sub.3 CH.sub.3 -- -- Cl Black 905 120-125    (m = 0) (n = 0) 27 CH.sub.3 CH.sub.3 -- p-t-C.sub.4 H.sub.9 O Cl Blue black 885 Difficult to    (m = 0)     crystallize 28 CH.sub.3 CH.sub.3 -- p-s-C.sub.4 H.sub.9 O Cl Blue black 885 165-168    (m = 0) 29 CH.sub.3 ##STR13## --(m = 0) p-CH.sub.3 O Cl Blue black 890 165(decomposition)  30 CH.sub.3 CH.sub.3 -- p-CH.sub.3 O 5,6-Cl.sub.2, 4,7-Br.sub.2 Blue black 884 145-148    (m = 0) 31 CH.sub.3 CH.sub.3 -- p-Cl Cl Black 915 133-135 (m = 0) 32 CH.sub.3 CH.sub.3 -- m-CH.sub.3, p-CH.sub.3 Cl Black 900 150-155    (m = 0) 33 C.sub.2 H.sub.5 C.sub.2 H.sub.5 OCH.sub.3 p-CH.sub.3 Cl Black 900 Difficult to         crystalli ze 34 C.sub.2 H.sub.5 C.sub.2 H.sub.5 OC.sub.3 H.sub.7 O p-CH.sub.3 O Cl Violetish black 820 Difficult to         crystallize 35 C.sub.4 H.sub.9 C.sub.4 H.sub.9 -- p-CH.sub.3 Cl Black 910 135-138    (m = 0) 36 C.sub.2 H.sub.5 C.sub.5 H.sub.11 -- p-CH.sub.3 O Cl Blue black 890 Difficult to (m = 0)     crystallize 37 C.sub.6 H.sub.13 C.sub.6 H.sub.13 -- p-CH.sub.3 Cl Black 910 Difficult to    (m = 0)     crystallize  38 C.sub.2 H.sub.5 ##STR14## --(m = 0) --(n = 0) Cl Black 920 Difficult tocrystallize  39 C.sub.2 H.sub.5 ##STR15## --(m = 0) p-CH.sub.3 Cl Black 910 Difficult tocrystallize  40 CH.sub.3 CH.sub.3 -- p-CH.sub.3 O 5-Cl, (Br).sub.3 Blue black 885 130-135    (m = 0) 41 CH.sub.3 CH.sub.3 -- p-C.sub.4 H.sub.9 O 5,6-(Cl).sub.2, 4,7-(Br).sub.2 Blue black 882 178-181    (m = 0) 42 CH.sub.3 CH.sub.3 -- p-C.sub.6 H.sub.13 O Br Blue black 882 Difficult to (m = 0)     crystallize 43 CH.sub.3 CH.sub.3 -- -- Br Black 910 145-148    (m = 0) (n = 0) 44 CH.sub.3 CH.sub.3 -- p-CH.sub.3 Br Black 890 224-226    (m = 0) 45 CH.sub.3 CH.sub.3 -- p-CH.sub.3 5-Cl, (Br).sub.3 Black 900 218-222    (m = 0) 46 CH.sub.3 CH.sub.3 -- p-t-C.sub.4 H.sub.9 Cl Black 895 198-200    (m = 0) 47 CH.sub.3 CH.sub.3 -- m-CH.sub.3 O, p-CH.sub.3 O Br Blue Black 890 136-140    (m = 0) 48 C.sub.2 H.sub.5 C.sub.2 H.sub.5 -- p-CH.sub.3 O Br Blue black 903 Difficult to    (m = 0) crystallize 49 C.sub.2 H.sub.5 C.sub.2 H.sub.5 -- p-CH.sub.3 Br Black 905 131-135    (m = 0) 50 C.sub.2 H.sub.5 C.sub.2 H.sub.5 m-CH.sub.3 p-CH.sub.3 O Br Blue black 910 Difficult to         crystallize 51 C.sub.4 H.sub.9 C.sub.4 H.sub.9 -- p-C.sub.2 H.sub.5 O Br Blue black 900 Difficult to    (m = 0)     crystallize 52 C.sub.2 H.sub.5 i-C.sub.5 H.sub.11 -- p-t-C.sub.4 H.sub.9 Br Black 905 Difficult to    (m = 0) crystallize  53 C.sub.2 H.sub.5 ##STR16## --(m = 0) p-CH.sub.3 O Br Blue black 900 165-168 54 CH.sub.3 ##STR17## --(m = 0) p-CH.sub.3 O Br Blue black 910 185-188  55 C.sub.2 H.sub.5 ##STR18## m-CH.sub.3 O m-(CH.sub.3), p-(CH.sub.3) 5-Cl, (Br).sub.3 Black 900 Difficult tocrystallize  56 CH.sub.3 CH.sub.3 OC.sub.2 H.sub.4 -- p-CH.sub.3 O Cl Blue black 885 95    (m = 0)     (decomposition) 57 CH.sub.3 CH.sub.2CHCH.sub.2 -- p-CH.sub.3 Cl Reddish black 900 113-115 (m = 0) 58 C.sub.2 H.sub.5 CH.sub.3 OC.sub.3 H.sub.6 -- p-CH.sub.3 O Br Blue black 880 Difficult to    (m = 0)     crystallize 59 CH.sub.3 C.sub.2 H.sub.5 OC.sub.3 H.sub.6 -- p-CH.sub.3 O, m-CH.sub.3 O Cl Blue black 887 112-115 60 CH.sub.3 OC.sub.2 H.sub.4 CH.sub.3 OC.sub.2 H.sub.4 -- p-Cl Cl Reddish black 920 Difficult to    (m = 0)     crystallize 61 CH.sub.3 CH.sub.3 OC.sub.3 H.sub.6 OCH.sub.3 p-CH.sub.3 O Cl Blue black 880 Difficult to         crystallize 62 CH.sub.3 ##STR19## --(m = 0) p-C.sub.2 H.sub.5 O, m-CH.sub.3 Cl Blue black 890 125-129  63 C.sub.2 H.sub.5 ##STR20## --(m = 0) p-t-C.sub.4 H.sub.9 Cl Black 897 Difficult tocrystallize  64 CH.sub.3 CH.sub.2CHCH.sub.2 -- p-CH.sub.3 Br Reddish black 892 116-120 (m = 0) 65 CH.sub.3 CH.sub.2CHCH.sub. 2 -- p-CH.sub.3 5-Cl, (Br).sub.3 Reddish black 893 108-112    (m = 0) 66 CH.sub.3 CH.sub.2CHCH.sub.2 -- p-CH.sub.3 5,6-Cl.sub.2, 4,7-Br.sub.2 Reddish black 895 105-108    (m = 0) 67 CH.sub.3 CH.sub.2CHCH.sub.2 -- p-CH.sub.3 F Reddish black 891 Difficult to    (m = 0)     crystallize 68 H CH.sub.3 -- p-CH.sub.3 O Cl Blue black 870 Difficult to    (m = 0)     crystallize  69 CH.sub.3 CH.sub.3 --(m = 0) ##STR21## Cl Blue black 892 83(decomposition)  70 CH.sub.3 CH.sub.3 -- p-CH.sub.3 OC.sub.2 H.sub.4 O Cl Blue black 890 145-148    (m = 0)  71 CH.sub.3 CH.sub.3 -- (m = 0) ##STR22## Cl Blue black 895 151-154  72 CH.sub.3 CH.sub.3 --(m = 0) ##STR23## Cl Blue black 897 168-171  73 CH.sub.3 CH.sub.3 --(m = 0) ##STR24## Br Blue black 895 Difficult tocrystallize  74 CH.sub.3 CH.sub.3 -- p-(C.sub.8 H.sub.17 O) Cl Blue black 893 Difficult to    (m = 0) crystallize

Production of a pressure-sensitive copying paper.

Into 95 parts by weight of monoisopropylbiphenyl, 5 parts by weight of the compound of Example 2, namely, 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-ethoxyphenyl)-ethenyl]-4,5,6,7-tetr achlorophthalide, were dissolved and a solution of 24 parts by weight of gelatine and 24 parts by weight of gum arabic into 400 parts by weight of water, of which pH was adjusted to 7, was added to the monoisopropylbiphenyl solution and the mixture was emulsified by a homogenizer. Into the emulsion, 100 parts by weight of warm water were added and after stirring the mixture for 30 minutes at 50.degree. C. about one part by weight of an aqueous 10% solution of sodium hydroxide was added and the mixture was further stirred for another 30 minutes at the same temperature.

In the next step, dilute acetic acid was added to the mixture to adjust the pH to 4.5 and after stirring for about one hour at 50.degree. C., the mixture was cooled to 0.degree. to 5.degree. C. and stirred for 30 minutes. Then, 35 parts by weight of an aqueous 4% solution of glutaraldehyde were slowly added to the mixture to harden the resulting capsules and pH of the mixture was adjusted to 6 by adding a dilute aqueous solution of sodium hydroxide to complete the capsulation. During the operations, no coloring was observed.

The capsule suspension obtained was uniformly coated on a sheet of paper by a wire-bar so that the coated weight of capsules after drying became 6 g/m.sup.2 and the sheet was dried to obtain a capsule-coated paper sheet (the upper paper sheet).

On piling the upper paper sheet onto a sheet of paper coated with a phenol-formaldehyde resin as a developer and applying writing pressure by a ball-pen on the sheets of paper, letters of deep black in color rapidly appeared on the piled-up sheets of paper.

The color image appeared were excellent in light-resistance and moisture-resistance and since the image had a strong absorption in the range of 800 to 1000 nm, it was possible to read the letters by OCR. Furthermore, the surface of the paper coated with the capsules had an excellent light-resistance, and its color and chromogenic ability were not reduced by sun light.

In the same manner as in Production Example 1 except for using 5 parts by weight of the compound (D) as the chromogenic agent, a pressure-sensitive copying paper was prepared.

On subjecting the pressure-sensitive copying paper to color-development by a lower paper sheet on which a phenolformaldehyde resin had been applied, a light green image appeared slowly.

As the absorption of near infrared rays by the image was weak, it was difficult to read it by OCR (refer to FIG. 1).

Production of a heat-sensitive recording paper:

(1) Preparation of a liquid dispersion of a chromogenic agent (A-liquid).

A mixture of the following recipe was pulverized by a paintshaker (made by Toyo-Seiki Co., Ltd.) until the mean diameter of the particles of the chromogenic agent bacame 2 .mu.m: 3,3-bis[2-(1-p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-te trachlorophthalide (Synthetic Example 1)

(2) Preparation of a liquid dispersion of a developer and a sensitizer (B-liquid).

A mixture of the following recipe was pulverized by a paintshaker until the mean diameter of the particles of developer and sensitizer became 3 .mu.m:

(3) Preparation and application of a liquid heat-sensitive material.

By mixing 10 parts by weight of A-liquid and 6.5 parts by weight of B-liquid, a liquid heat-sensitive material was obtained. The liquid material was coated on a sheet of paper by a wire-bar uniformly so that the coated weight of solid materials after drying became 6 g/m.sup.2 and the sheet of paper was dried to obtain a heat-sensitive recording paper.

The heat-sensitive recording paper was nearly colorless and did not show any spontaneous coloring (refer to FIG. 3). The heat-sensitive recording paper showed a dark-black color by the heating with a heated pen. The color image obtained was excellent in light-resistance and moisture-resistance and as the color image had a strong absorption in the range of 700 and 1050 nm, it was possible to read the image by OCR.

The same results have been obtained on using the compounds in another Synthetic Examples.

In the same manner as in Production Example 2 except for using 5 parts by weight of the compound (A), a heat-sensitive recording paper was obtained. Although the heat-sensitive recording paper was colored into black by heating with a heated pen, as the color image did not absorb any near infrared rays, it was impossible to read the color image by OCR (refer to FIG. 2).

In the same manner as in Production Example 2 except for using 5 parts by weight of the compound (B), a heat-sensitive recording paper was obtained. The heat-sensitive recording paper showed yellowish green spontaneous coloring. On heating the paper with a heated pen, green color was developed (refer to FIGS. 2 and 3).

From the above Production Examples and Comparative Examples, it has been confirmed that the divinyl compound according to the present invention is the excellent chromogenic agent for the recording materials.

## Claims

1. A divinyl compound represented by the formula (I): ##STR25## wherein X.sup.1 represents an alkyl group, an alkoxy group or a halogen atom; X.sup.2 represents an alkyl group, an alkoxy group, a halogen atom or R.sup.3 O--; X.sup.3 represents a halogen atom; R.sup.1 represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, a haloalkyl group, an alkenyl group, an aralkyl group, a cyclohexylmethyl group, a methylcyclohexyl group, a trimethylcyclohexyl group, a furfuryl group, a tetrahydrofurfuryl group or a tetrahydropyran-2-yl-methyl group; R.sup.2 represents a cycloalkyl group, a phenyl group, a benzyl group, a phenyl or a benzyl group substituted by a chlorine atom, a bromine atom or an alkyl or alkoxy group both of which have not more than four carbon atoms or any one of R.sup.1 ; R.sup.3 represents an aryl group, a cycloalkyl group, an alkoxyalkyl group, an alkenyl group, a haloalkyl group or an aralkyl group and m and n respectively represent an integer of 0, 1, 2 or 3, wherein X.sup.1 of (X.sup.1).sub.m or X.sup.2 of (X.sup.2).sub.n can be same or different when m, n or both are not less than 2 and X.sup.3 of (X.sup.3).sub.4 can be same or different.

2. A divinyl compound according to claim 1, wherein R.sup.1 represents an alkyl group of not more than six carbon atoms, an alkoxyalkyl group of not more than six carbon atoms, a haloalkyl group of not more than six carbon atoms, an alkenyl group of not more than six carbon atoms, a cyclohexyl group, a cyclohexylmethyl group, a methylcyclohexyl group, a trimethylcyclohexyl group, a furfuryl group, a tetrahydrofurfuryl group, a tetrahydropyrane-2-yl-methyl group, a benzyl group or a benzyl group substituted with an alkyl group of not more than four carbon atoms; R.sup.2 represents a phenyl group, a phenyl group substituted with a chlorine atom or an alkyl group of not more than four carbon atoms or any one of R.sup.1 ; X.sup.1 represents a methyl group, a methoxy group or an ethoxy group; X.sup.2 represents a halogen atom, an alkyl group of not more than six carbon atoms, an alkoxy group of not more than six carbon atoms, an alkoxyalkoxy group of not more than six carbon atoms, a cyclohexyloxy group, a benzyloxy group, a phenoxy group or a phenoxy or a benzyloxy group substituted with an alkyl or an alkoxy group both of which have not more than four carbon atoms; m is 0 or 1 and n is 0, 1 or 2.

3. A divinyl compound according to claim 2, wherein R.sup.1 represents an alkyl group of not more than six carbon atoms; R.sup.2 represents an alkyl group of not more than six carbon atoms or a cyclohexyl group; X.sup.2 represents a halogen atom, an alkyl group of not more than six carbon atoms, an alkoxy group of not more than six carbon atoms, and alkoxyalkoxy group of not more than six carbon atoms, a cyclohexyloxy group, a phenoxy group, a benzyloxy group or a phenoxy or benzyloxy group substituted with an alkyl or an alkoxy group both of which have not more than four carbon atoms; X.sup.3 represents a chloride atom, m is 0 and n is 0, 1 or 2.

4. A divinyl compound according to claim 3, wherein R.sup.1 represents a methyl group or an ethyl group; R.sup.2 represents a methyl group, an ethyl group, an n-propyl group or an iso-propyl group; X.sup.2 represents a methyl group, an alkoxy group of not more than five carbon atoms and n is 1 or 2.

5. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-t etrachlorophthalide.

6. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-te trachlorophthalide.

7. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-diethylaminophenyl)-2-(methoxyphenyl)ethenyl]-4,5,6,7-tetr achlorophthalide.

8. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-propoxyphenyl)ethenyl]-4,5,6,7-t etrachlorophthalide.

9. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-iso-propoxyphenyl)ethenyl]-4,5,6 ,7-tetrachlorophthalide.

10. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-butoxyphenyl)ethenyl]-4,5,6,7-tetra chlorophthalide.

11. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-iso-butoxyphenyl)ethenyl]-4,5,6,7-t etrachlorophthalide.

12. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-methylethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-t etrachlorophthalide.

13. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-methylpropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7- tetrachlorophthalide.

14. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetra chlorophthalide.

15. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-ethylpropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-t etrachlorophthalide.

16. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-methyl-iso-propylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5 ,6,7-tetrachlorophthalide.

17. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-ethyl-iso-propylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5, 6,7-tetrachlorophthalide.

18. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dipropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetr achlorophthalide.

19. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-methylbutylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-t etrachlorophthalide.

20. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-ethylbutylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-te trachlorophthalide.

21. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-diethylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetrac hlorophthalide.

22. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(m-methyl-p-methoxyphenyl)ethenyl]-4,5 ,6,7-tetrachlorophthalide.

23. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-pentyloxyphenyl)ethenyl]-4,5,6,7-te trachlorophthalide.

24. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetr abromophthalide.

25. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-iso-pentyloxyphenyl)ethenyl]-4,5,6, 7-tetrachlorophthalide.

26. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(m,p-dimethoxyphenyl)ethenyl]-4,5,6,7- tetrachlorophthalide.

27. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-methylethylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-te trachlorophthalide.

28. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-methylpropylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-t etrachlorophthalide.

29. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-ethylphenyl)ethenyl]-4,5,6,7-tetrac hlorophthalide.

30. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrachlorophth alide.

31. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-tert-butoxyphenyl)ethenyl]-4,5,6,7- tetrachlorophthalide.

32. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-sec-butoxyphenyl)ethenyl]-4,5,6,7-t etrachlorophthalide.

33. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-methylcyclohexylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5, 6,7-tetrachlorophthalide.

34. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-5,6-dichloro -4,7-dibromophthalide.

35. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-methylmethoxyethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4, 5,6,7-tetrachlorophthalide.

36. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis[2-(p-methylallylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-te trachlorophthalide.

37. A divinyl compound according to claim 1, wherein said divinyl compound is 3,3-bis{2-(p-dimethylaminophenyl)-2-[p-methoxyphenoxy)phenyl]ethenyl}-4,5, 6,7-tetrachlorophthalide.