DIVINYL COMPOUNDS AND CHROMOGENIC RECORDING-MATERIAL PREPARED BY USE THEREOF

Abstract: Divinyl compounds represented by the formula (I) wherein X¹ represents an alkyl group, an alkoxy group or a halogen atom; X² represents an alkyl group, an alkoxy group, a halogen atom or R³O-; X³ represents a halogen atom; R¹ 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; R² 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 that four carbon atoms or any one of R¹; R₃ represents an aryl group, a cycloalkyl group, an alkoxyalkyl group, an alkenyl group, a haloalkyl group or an aralkyl group; and m and n each represents 0, l, 2 or 3; wherein each X¹ or each X² is the same or different when m or n respectively is 2 or 3 and each X³ is the same or different; are chromogenic agents useful for recording materials such as pressure-and heat-sensitive papers.

Description: The present invention relates to a divinyl compound suitable for use as a chromogenic agent in a recording material such as a pressure-sensitive recording paper, heat-sensitive recording paper or electro-heat sensitive recording paper, to a process for the preparation of such a compound and to a recording material incorporating such a compound. DE-A-2,218,895 describes a chromogenic tetrachlorophthalide of formula: wherein each R' is an alkyl, phenyl, phenylalkyl or alkoxy substituted or unsubstituted p-aminophenyl₁ pyrrol-2-yl or indol-3-yl group, wherein the alkyl groups contain from 1 to 4 carbon atoms. EP-A-62,544 describes a chromogenic phthalide derivative of formula: wherein R'₁ is hydrogen or at least one of halogen, alkyl, alkoxy, nitro, amino and substituted amino; R'₂ is hydrogen or alkyl; each R'₃, R'₄, R'₅ and R'₆ is hydrogen, alkyl, aralkyl, substituted aralkyl, aryl or substituted aryl, or one or both of R'₃ and R'₄, together with the adjacent nitrogen, may form a heterocyclic ring and one or both of R'₅ and R'₆, together with the adjacent nitrogen, may form a heterocyclic ring; each X'₁ and Y'₁ is hydrogen, alkyl or alkoxy; and A ' may be various phenyl or diphenylvinyl groups. Chemical Abstracts 102:195296f describes a chromogenic phthalide derivative of formula: wherein: R" is hydrogen or alkyl; R₁" and R₂" are alkyl, an aliphatic cyclic moiety, aryl or aralkyl or form heterocyclic rings with each other or by bonding with the carbon atoms in the benzene ring; R₃" is hydrogen, alkyl, alkoxy or acyloxy; and A" is a benzene ring or a 6-membered heterocyclic aromatic ring containing 1 or 2 nitrogen atoms. Chemical Abstracts 107:49640a discloses a pressure-sensitive recording paper comprising a combination of a FE(III) or a V compound and a compound of formula (I') or (II'): wherein, in formula (I'), R₁''' and R₂''' are alkyl or aryl or, together or in conjunction with an adjoining benzene ring, form a heterocycle; R₃''' is hydrogen, alkyl, alkoxy or aryloxy; R₄''' is hydrogen or alkyl; and a,b,c and d are carbon or nitrogen or a-b, b-c or c-d form another aromatic ring; and, in formula (II'), R₁₋₆''' are C₁₋₄ alkyl. Chemical Abstracts 102:229544c discloses a leuco pigment of formula (I") or (III"): wherein, in formula (I"), R"" is hydrogen, halogen, alkyl, alkoxy, NR₉"" R₁₀"" or (II); R₁"" is hydrogen, halogen, alkyl or alkylamino; R₂"" is hydrogen or alkyl; R₃"" and R₄"" are hydrogen, alkyl or alkoxy; R₅₋₈"" are alkyl or cycloalkyl or R₅"" and R₆"" or R₇"" and R₈"" form a heterocycle with an adjacent N; m is 1 to 4, R₉"" and R₁₀"" are alkyl or cycloalkyl, n and p are at least one with the proviso that n + p is at least 4; and X"" is 5,0 or CH₂; and, in formula (III'''), R"", R₁₋₃"" and R₁₁₋₁₄"" are alkyl or cycloalkyl or R"" and R₁"", R₂"" and R₃"", R₁₁"" and R₁₂"" or R₁₃"" and R₁₄"" form a heterocycle with an adjacent N; R₄"", R₅"", R₉"" and R₁₀"" are hydrogen, alkyl or alkoxy; R₆"" and R₈"" are hydrogen or alkyl; R₇"" is hydrogen, halogen, alkyl or alkylamino and m is 1 to 4. The color image provided by the following 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. Accordingly the color image cannot be read by an optical letter-reading apparatus (refer to Figure 2): (refer to JP-B-56-52759/1981). Chromogenic agents having an absorption in the near infrared region have been recently proposed in JP-B-58-5940/1983, JP-A-59-199757/1984 and JP-A-60-230890/1985. However, each of the proposed compounds has the following defects and a satisfactory chromogenic agent has not yet been obtained. Compound (B) (see below) of JP-B-58-5940/1983 and compound (C) (see below) of JP-A-60-230890/1985 are themselves strongly colored yellow and besides spontaneously color. These defects have a very bad effect on the production of recording materials. Although the fluorene compound (D) (see below) of JP-A-59-199757/1984 is colorless, its chromogenic property and the stability of color image produced are poor. Furthermore, the hue of each of compounds (B), (C) and (D) when developed is green. Accordingly, to obtain a blackish color, another chromogenic agent giving a red or black color must be added in a large amount. Since the chromogenic property and the chromogenic speed of such an agent are different from those of compounds (B), (C) and (D) and, particularly, the light-resistance of red-chromogenic agents is generally poor, adverse influences such as unbalance of color-development and reduction of light-resistance cannot be avoided. (refer to JP-B-58-5940/1983). (refer to JP-A-60-230890/1985). (refer to JP-A-59-199757/1984). The present inventors have sought to improve the defects of the conventional chromogenic agents. The present invention provides a divinyl compound represented by the formula (I): wherein X¹ represents an alkyl group, an alkoxy group or a halogen atom; X² represents an alkyl group, an alkoxy group, a halogen atom or R³0-; X³ represents a halogen atom; R¹ 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 tetrahydropyrane-2-yl-methyl group; R² represents any group defined by R¹ above, a cycloalkyl group, a phenyl group, a benzyl group, a phenyl or a benzyl group substituted by chlorine atom(s), bromine atom(s) or alkyl group(s) which have not more than four carbon atoms or by an alkoxy group which has not more than four carbon atoms; R³ represents a cycloalkyl group, an alkoxyalkyl group, an alkenyl group, a haloalkyl group or an aralkyl group; and m and n each represents 0, 1, 2 or 3; wherein each X¹ or each X² is the same or different when m or n respectively is 2 or 3 and each X³ is the same or different. (Hereinafter the same sign means the same meaning). The divinyl compounds represented by the formula (I) are by themselves almost colorless, extremely stable in the atmosphere, have no subliming property and spontaneously chromogenic property and dissolve extremely well in organic solvents. They give a blackish color rapidly with a developer and the color image produced has excellent light-resistance and moisture-resistance. Furthermore, since the color image has a strong absorption between 700 and 1000 nm in addition to the visible region, the color image has the distinctive feature that it is possible to be read by optical letter-reading apparatus using near infrared rays (such as OCR and OMR) and by barcode reading apparatus. Thus the divinyl compounds of the present invention (hereinafter sometimes referred to as the present compounds) are extremely valuable and can be used as chromogenic agents for ordinary recording-material requiring a black color, for which demand is rapidly increasing recently, as well as material readable by, for example, OCR or OMR. Preferred compounds of the present invention are those wherein R¹ represents an alkyl group having not more than six carbon atoms, an alkoxyalkyl group having not more than six carbon atoms, a haloalkyl group having not more than six carbon atoms, an alkenyl group having 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 having not more than four carbon atoms; R² represents any group defined by R¹ above, a phenyl group, a phenyl group substituted with a chlorine atom or an alkyl group having not more than four carbon atoms; X¹ represents a methyl group, a methoxy group or an ethoxy group; X² represents a halogen atom, an alkyl group having not more than six carbon atoms, an alkoxy group having not more than six carbon atoms, an alkoxyalkoxy group having 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. More preferred compounds of the present invention are those wherein R¹ represents an alkyl group having not more than six carbon atoms; R² represents an alkyl group having not more than six carbon atoms or a cyclohexyl group; X² represents a halogen atom, an alkyl group having not more than six carbon atoms, an alkoxy group having not more than six carbon atoms, an alkoxyalkoxy group having 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; X³ represents a chlorine atom, m is 0 and n is 0, 1 or 2. Even more preferred compounds of the present invention are those wherein R¹ represents a methyl group or an ethyl group; R² represents a methyl group, an ethyl group, an n-propyl group or an iso-propyl group; X² represents a methyl group, an alkoxy group having not more than five carbon atoms and n is 1 or 2. The divinyl compounds represented by the formula (I) have unexpectedly excellent properties such as solubility, the color of the compound itself, the hue of the developed color, the chromogenic property, the absorbancy of near infrared rays and the stability of the color image produced. Of the attached drawings, Figures 1 and 2 are the reflection spectra of a color image of a pressure-sensitive and heat-sensitive recording paper incorporating the present compound and a comparison compound, respectively, and Figure 3 is the reflection spectra of a texture of a heat-sensitive recording paper incorporating the present compound and the comparison compound. Examples of the present compounds are given below. 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. 1. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 2. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 3. 3,3-Bis(2-(p-diethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 4. 3,3-Bis(2-(p-dimethylaminophenyl)-2-(p-propoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 5. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-isopropoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 6. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-butoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 7. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-isobutoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 8. 3,3-Bis[2-(p-methylethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 9. 3,3-Bis[2-(p-methylpropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l0. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide ll. 3,3-Bis[2-(p-ethylpropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l2. 3,3-Bis[2-(p-methylisopropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l3. 3,3-Bis[2-(p-ethylisopropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l4. 3,3-Bis[2-(p-dipropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l5. 3,3-Bis[2-(p-methylbutylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l6. 3,3-Bis[2-(p-ethylbutylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l7. 3,3-Bis[2-(p-diethylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l8. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m-methyl-p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l9. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-pentyloxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 20. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 2l. 3,3-Bis[2-(p-dimethylaminophenyl}-2-(p-isopentyloxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 22. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m,p-dimethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 23. 3,3-Bis[2-(p-methylpropylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 24. 3,3-Bis[2-(p-ethylpropylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 25. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-ethylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 26. 3,3-Bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrachlorophthalide 27. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-tert-butoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 28. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-sec-butoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 29. 3,3-Bis[2-(p-methylcyclohexylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 30. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-5,6-dichloro-4,7-dibromophthalide 3l. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m,p-dimethylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 32. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(o-methyl-p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 33. 3,3-Bis[2-(p-dimethylamino-o-methylphenyl)-2-phenylethenyl]-4,5,6,7-tetrachlorophthalide 34. 3,3-Bis[2-(p-dimethylamino-o-chlorophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 35. 3,3-Bis[2-(p-dimethylamino-m-methylphenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 36. 3,3-Bis[2-(p-dimethylamino-o-ethylphenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 37. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-chlorophenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 38. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(o,p-dimethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 39. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 40. 3,3-Bis[2-(p-dipropylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 4l. 3,3-Bis[2-(p-dibutylamino-o-methylphenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 42. 3,3-Bis[2-(p-dihexylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrachlorophthalide 43. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-octylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 44. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-hexyloxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 45. 3,3-Bis[2-(p-methylcyclohexylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 46. 3,3-Bis[2-(p-ethylbenzylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 47. 3,3-Bis[2-(p-ethyltolylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrachlorophthalide 48. 3,3-Bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrabromophthalide 49. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-fluorophenyl)ethenyl]-4,5,6,7-tetrabromophthalide 50. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-chlorophenyl)ethenyl]-4,5,6,7-tetrabromophthalide 5l. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m,p-dimethoxyphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 52. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m,p-dimethylphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 53. 3,3-Bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-5-chloro-4,6,7-tribromophthalide 54. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m-methylphenyl)ethenyl]-5-chloro-4,6,7-tribromophthalide 55. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-hexyloxyphenyl)ethenyl]-5-chloro-4,6,7-tribromophthalide 56. 3,3-Bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-6-chloro-4,5,7-tribromophthalide 57. 3,3-Bis[2-(p-dimethylamino-o-chlorophenyl)-2-(p-methylphenyl)ethenyl]-6-chloro-4,5,7-tribromophthalide 58. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-6-chloro-4,5,7-tribromophthalide 59. 3,3-Bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-5,6-dichloro-4,7-dibromophthalide 60. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m-methyl-p-methoxyphenyl)ethenyl]-5,6-dichloro-4,7-dibromophthalide 6l. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(m-methoxyphenyl)ethenyl]-5,6-dichloro-4,7-dibromophthalide 62. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-butoxyphenyl)ethenyl]-4,5,6,7-tetrabromophenylphthalide 63. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-hexyloxyphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 64. 3,3-Bis[2-(p-dimethylamino-o-methylphenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 65. 3,3-Bis[2-(p-dimethylamino-m-methylphenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 66. 3,3-Bis[2-(p-dimethylamino-m-ethoxyphenyl)-2-phenylethenyl]-4,5,6,7-tetrabromophthalide 67. 3,3-Bis[2-(p-diethylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 68. 3,3-Bis[2-(p-dipropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 69. 3,3-Bis[2-(p-dibutylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 70. 3,3-Bis[2-(p-dihexylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 7l. 3,3-Bis[2-(p-methylbutylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 72. 3,3-Bis[2-(p-methylcyclohexylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 73. 3,3-Bis[2-(p-ethylbenzylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrabromophthalide 74. 3,3-Bis[2-(p-ethyltolylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 75. 3,3-Bis[2-(p-aminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 76. 3,3-Bis[2-(p-ethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 77. 3,3-Bis[2-(p-methylmethoxyethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 78. 3,3-Bis[2-(p-methylethoxypropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 79. 3,3-Bis[2-(p-dimethoxyethylaminophenyl)-2-(p-methylphenyl)ethenyl]-5-chloro-4,6,7-tribromophthalide 80. 3,3-Bis[2-(p-benzylmethoxypropylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 8l. 3,3-Bis[2-(p-cyclohexylethoxyethylaminophenyl)-2-phenylethenyl]-5,6-dichloro-4,7-dibromophthalide 82. 3,3-Bis[2-(p-methylmethoxyethylaminophenyl)-2-(p-chlorophenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 83. 3,3-Bis[2-(p-ethylmethoxyethylamino-m-methylphenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 84. 3,3-Bis[2-(p-methylethoxypropylamino-m-ethoxyphenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 85. 3,3-Bis[2-(p-methylallylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 86. 3,3-Bis[2-(p-diallylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 87. 3,3-Bis[2-(p-ethyl-γ-chloropropylaminophenyl)-2-(m,p-dimethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 88. 3,3-Bis[2-(p-di-γ-chloropropylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetrabromophthalide 89. 3,3-Bis[2-(p-cyclopentyl-γ-chloropropylaminophenyl)-2-(p-butoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 90. 3,3-Bis[2-(p-methylcyclohexylmethylaminophenyl)-2-(p-methoxy-m-methylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 9l. 3,3-Bis[2-(p-ethyl-4-methylcyclohexylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrafluorophthalide 92. 3,3-Bis[2-(p-methyl-3,3,5-trimethylcyclohexylaminophenyl)-2-(p-butylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 93. 3,3-Bis[2-(p-4-methylbenzylmethoxypropylaminophenyl)-2-(m,p-dimethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 94. 3,3-Bis[2-(p-ethylfurfurylaminophenyl)-2-(m,p-dimethylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 95. 3,3-Bis[2-(p-methyltetrahydrofurfurylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 96. 3,3-Bis[2-(p-ditetrahydrofurfurylaminophenyl)-2-(m-methyl-p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 97. 3,3-Bis[2-(p-benzyltetrahydrofurfurylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-5-chloro-4,6,7-tribromophthalide 98. 3,3-Bis[2-(p-methyltetrahydropyrane-2-yl-methylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 99. 3,3-Bis[2-(p-methylmethoxyethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrafluorophthalide l00. 3,3-Bis[2-(p-methylethoxypropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrafluorophthalide l0l. 3,3-Bis[2-(p-dimethoxyethylaminophenyl)-2-(p-methylphenyl)ethenyl]-5-chloro-4,6,7-triiodophthalide l02. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-methoxyethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l03. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-allyloxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l04. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-chloropropyloxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide l05. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-cyclopentyloxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 106. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-cyclohexyloxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 107. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-benzyloxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 108. 3,3-Bis[2-(p-dimethylaminophenyl)-2-(p-phenoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 109. 3,3-Bis(2-[p-dimethylaminophenyl]-2-[p-(p-methoxyphenoxy)phenyl]ethenyl}-4,5,6,7-tetrachlorophthalide 110. 3,3-Bis{2-[p-diethylaminophenyl]-2-[p-(p-methoxyphenoxy)phenyl]ethenyl}-4,5,6,7-tetrachlorophthalide The divinyl 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: wherein R¹, R², X¹, X², m and n are as defined above and X represents a halogen atom. The ethylene derivative of formula (2) and a phthalic acid derivative of Formula (3) (see below) are condensed in a molar ratio of 2:1 and in the presence of a dehydrating agent such as acetic anhydride or sulfuric acid, and by purifying the reaction product, the divinyl compounds represented by the formula (I) are obtained as nearly colorless crystals. wherein X³ is as defined above. Examples of the ethylene derivative represented by the formula (2) are: 1. 1-phenyl-1-(p-dimethylaminophenyl)ethylene 2. 1-(p-methylphenyl)-1-(p-dimethylaminophenyl)ethylene 3. 1-(m,p-dimethylphenyl)-1-(p-dimethylaminophenyl)ethylene 4. 1-(p-methoxyphenyl)-1-(p-dimethylaminophenyl)ethylene 5. 1-(p-ethoxyphenyl)-1-(p-dimethylaminophenyl)ethylene 6. l-(p-methylphenyl)-l-(p-dimethylamino-o-methylphenyl)ethylene 7. l-(p-methylphenyl)-l-(p-dimethylamino-o-ethoxyphenyl)ethylene 8. l-(p-methoxyphenyl)-l-(p-dimethylamino-o-methylphenyl)ethylene 9. l-phenyl-l-(p-dimethylamino-m-methylphenyl)ethylene l0. l-(p-methoxy-o-methylphenyl)-l-(p-dimethylaminophenyl)ethylene ll. l-(p-chlorophenyl)-l-(p-dimethylaminophenyl)ethylene l2. l-(p-methoxyphenyl)-l-(p-dimethylamino-o-chlorophenyl)ethylene l3. l-(p-butoxyphenyl)-l-(p-dimethylaminophenyl)ethylene l4. l-(p-methoxyphenyl)-l-(p-diethylaminophenyl)ethylene l5. l-(p-methylphenyl)-l-(p-dipropylamino-o-ethoxyphenyl)ethylene l6. l-(p-ethoxyphenyl)-l-(p-dipentylaminophenyl)ethylene l7. l-phenyl-l-(p-dioctylaminophenyl)ethylene l8. l-(p-methylphenyl)-l-(p-methylbutylaminophenyl)ethylene l9. l-(p-methoxyphenyl)-l-(p-methylcyclohexylaminophenyl)ethylene 20. l-(p-methylphenyl)-l-[p-ethyl-(p-methylbenzyl)aminophenyl]ethylene 2l. l-phenyl-l-[p-ethyl-(p-tolyl)aminophenyl]ethylene 22. l-(p-methoxyphenyl)-l-(p-methylaminophenyl)ethylene 23. l-(p-methoxyphenyl)-l-(p-methylmethoxyethylaminophenyl)ethylene 24. l-(p-chlorophenyl)-l-(p-ethylethoxypropylamino-m-methylphenyl)ethylene 25. l-(p-methoxyphenyl)-l-(p-diethoxyethylaminophenyl)ethylene 26. l-(m,p-dimethylphenyl)-l-(p-propyl-γ-chloropropylaminophenyl)ethylene 27. l-(p-methoxyphenyl)-l-(p-di-γ-chloropropylaminophenyl)ethylene 28. l-(m,p-dimethoxyphenyl)-l-(p-cyclohexyl-γ-chloropropylaminophenyl)ethylene 29. l-(p-ethoxyphenyl)-l-(p-ethylallylaminophenyl)ethylene 30. l-(p-isopropoxyphenyl)-l-(p-diallylaminophenyl)ethylene 3l. l-(p-methoxyphenyl)-l-(p-ethylcyclohexylmethylaminophenyl)ethylene 32. l-(p-methoxyphenyl)-l-(p-dicyclohexylmethylaminophenyl)ethylene 33. l-(p-methoxyphenyl)-l-[p-methyl-(3-methylcyclohexyl)aminophenyl]ethylene 34. l-(p-ethoxy-m-methylphenyl)-l-[p-ethyl-(3,3,5-trimethylcyclohexyl)aminophenyl]ethylene 35. l-(p-methoxyphenyl)-l-(p-methylfurfurylaminophenyl)ethylene 36. l-(p-methoxyphenyl)-l-(p-ethyltetrahydrofurfurylaminophenyl)ethylene 37. l-(m-methyl-p-ethoxyphenyl)-l-(p-ethyltetrahydropyrane-2-yl-methylaminophenyl)ethylene 38. 1-(p-methoxyphenyl)-1-(p-ditetrahydropyrane-2-yl-methylaminophenyl)ethylene 39. 1-phenyl-1-(p-aminophenyl)ethylene 40. 1-(m,p-dimethoxyphenyl)-1-(p-dimethylaminophenyl)ethylene 41. 1-(p-bromophenyl)-1-(p-dimethylaminophenyl)ethylene Examples of the phthalic acid derivatives represented by the formula (3) are: 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. The present invention also provides a recording material incorporating, as a chromogenic agent, a divinyl compound represented by the formula (I) as defined above or which has been prepared by a process as defined above. In case where a pressure-sensitive recording paper or a heat-sensitive recording paper, for example, is produced with these divinyl compounds, one or more of the compounds can be used. By mixing not less than two of the compounds, the chromogenic property and the image stability are improved. Moreover, to improve the hue and the concentration of developed color, and the stability of the color image, various known chromogenic agents which give various hues can be used with the present compounds to the extent that they do not damage the facilities of the present compounds. For instance, the present compounds can be used with a chromogenic agent which has a fundamental skeleton of 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 or tetraaminodivinylphthalide. When producing a pressure-sensitive recording paper, various solvents for the chromogenic agent can be used, such as those of the alkylbenzene series, alkylbiphenyl series, alkylnaphthalene series, diarylethane series, hydrogenated terphenyl series and chlorinated paraffin series. These can be used singly or as a mixture. For encapsulation, a coacervation method, a interfacial polymerization method or an in-situ method can be used. As a developer, clays such as bentonite, activated clay or acid clay; metal salts of salicyclic acid, salicyclic ester derivatives or salicyclic acid derivatives,; hydroxy compounds such as 2,2-bis(p-hydroxyphenyl)propane (bisphenol A) or esters of p-hydroxybenzoic acid,; p-phenylphenol-formaldehyde resin, p-octylphenolformaldehyde resin and metal salts thereof are for example used. As a developer, one or more of the following hydroxy compounds can, for example, 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 and bis(4-hydroxy-3-methylphenyl)sulfide. When producing a heat-sensitive recording paper, polyvinyl alcohol, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, gum arabic, gelatine, caseine, starch, polyvinyl pyrrolidone, copolymer of styrene and maleic anhydride, can, for example, be used as a binder. Examples of sensitivity-improving agents are 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-bensyloxybenzoate; 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; and diphenyl carbonate. These can be used singly or after mixing together. 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 use a coating of a high polymeric substance. The present invention also provides the use as a chromogenic agent of a divinyl compound represented by the formula (I) as defined above or which has been prepared by a process as defined above. The present invention is further described in the following Examples. The Synthetic Examples illustrate the preparation of compounds represented by the formula (I). The Production Examples illustrate the preparation of chromogenic recording-materials incorporating the compound represented by the formula (I). SYNTHETIC EXAMPLE 1: Synthesis of 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 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°C. After adding the reaction mixture to 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 the toluene from the extract was recrystallised from butanol while purifying with activated carbon to obtain 14.3 g of pale yellow crystals melting at 133-135°C. By elementary analysis and by the infrared absorption spectrum and the nuclear magnetic resonance spectrum of the crystals obtained, it was confirmed that the crystals were of a compound represented by the following formula: This compound was rapidly colored blue-black by activated clay. The λmax in methanol·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 in 40 ml of ether was added to the mixture over 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 126-127°C) and 100 ml of tetrahydrofurane, and the solution was slowly added to the liquid reaction mixture. The mixture was stirred for one hour at a temperature of 40 to 50°C and then mixed with 400 ml of water and 300 ml of toluene. After making the mixture weakly acidic by dilute hydrochloric acid, the acidified mixture was stirred at 80°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, the toluene was distilled off from the filtrate to obtain 17.1 g of 1-(p-methoxyphenyl)-1-(p-dimethylaminophenyl)ethylene which was pale yellow in color and melted at 123-125°C. SYNTHETIC EXAMPLE 2: Synthesis of 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide 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 - 111°C) and 21.5 g of tetrachlorophthalic anhydride were added and the mixture was stirred for 6 hours at 120°C. After adding the reaction mixture to 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 the 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 - 170°C, and from elementary analysis, the infrared absorption spectrum and the nuclear magnetic resonance spectrum, it was confirmed that the compound was one represented by the following formula: This compound was rapidly colored blue-black by activated clay. The λmax of this compound in methanol·stannic chloride was 882 nm. SYNTHETIC EXAMPLES 3 - 74: By reacting various ethylene derivatives with various phthalic acid derivatives in the same manner as in Synthetic Examples 1 and 2, 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 compounds represented by the formula (I), any known method can be used, for instance, the coacervation method disclosed in US-A-2,800,458 and US-A-2,806,457. For preparing the heat-sensitive recording paper, a known method, for instance the method disclosed in JP-B-45-14039/1960, can be used. PRODUCTION EXAMPLE 1: 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-tetrachlorophthalide, were dissolved. A solution of 24 parts by weight of gelatine and 24 parts by weight of gum arabic in 400 parts by weight of water, of which the 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°C about one part by weight of an aqueous 10% solution of sodium hydroxide was added. 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°C the mixture was cooled to 0 to 5°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 in an amount such that the coated weight of capsules after drying was 6 g/m². The sheet was dried to obtain a capsule-coated paper sheet (the upper paper sheet). On placing the upper paper sheet on 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, deep black letters rapidly appeared on the sheets. The color image had excellent 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 excellent light-resistance, and its color and chromogenic ability were not reduced by sunlight. COMPARATIVE EXAMPLE 1: 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 Figure 1). PRODUCTION EXAMPLE 2: Production of a heat-sensitive recording paper: 1) Preparation of a liquid dispersion of a chromogenic agent (A-liquid). A mixture of the following composition was pulverized by a paintshaker (made by TOYO-SEIKI Co., Ltd.) until the mean diameter of the particles of the chromogenic agent became 2 µm: 5 parts by weight of 3,3-bis[2-(1-p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5₁6,7-tetrachlorophthalide (Synthetic Example 1) 15 parts by weight of kaolin, 100 parts by weight of an aqueous 10% solution of polyvinyl alcohol and 85 parts by weight of water 2) Preparation of a liquid dispersion of a developer and a sensitizer (B-liquid). A mixture of the following composition was pulverised by a paintshaker until the mean diameter of the particles of developer and sensitizer became 3 µm: 15 parts by weight of bisphenol A, 10 parts by weight of zinc stearate, 15 parts by weight of stearic amide and 150 parts by weight of an aqueous 10% solution of polyvinyl alcohol. 3) Preparation and application of a liquid heat-sensitive material. By mixing together 10 parts by weight of the A-liquid and 6.5 parts by weight of the B-liquid, a liquid heat-sensitive material was obtained. The liquid material was coated on a sheet of paper by a wire-bar uniformly in an amount such that the coated weight of solid materials after drying became 6 g/m². 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 Figure 3). The heat-sensitive recording paper showed a dark-black color after heating with a heated pen. The color image obtained had excellent light-resistance and moisture-resistance and as the color image had a strong absorption in the range of 700 to 1050 nm, it was possible to read the image by OCR. The same results have been obtained using the compounds in other Synthetic Examples. COMPARATIVE EXAMPLE 2: 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 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 Figure 2). COMPARATIVE EXAMPLE 3: 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, a green color developed (refer to Figures 2 and 3). From the above Production Examples and Comparative Examples, it is confirmed that the divinyl compound according to the present invention is an excellent chromogenic agent for recording materials.

Claims: A divinyl compound represented by the formula (I): wherein X¹ represents an alkyl group, an alkoxy group or a halogen atom; X² represents an alkyl group, an alkoxy group, a halogen atom or R³O-; X³ represents a halogen atom; R¹ 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; R² represents any group defined by R¹ above, a cycloalkyl group, a phenyl group, a benzyl group or a phenyl or a benzyl group substituted by chlorine atom(s), bromine atom(s) or alkyl group(s) which have not more than four carbon atoms or by an alkoxy group which has not more than four carbon atoms; R³ represents an aryl group, a cycloalkyl group, an alkoxyalkyl group, an alkenyl group, a haloalkyl group or an aralkyl group; and m and n each represents 0, 1, 2 or 3; wherein each X¹ or each X² is the same or different when m or n respectively is 2 or 3 and each X³ is the same or different. A divinyl compound according to claim 1, wherein R¹ represents an alkyl group having not more than six carbon atoms, an alkoxyalkyl group having not more than six carbon atoms, a haloalkyl group having not more than six carbon atoms, an alkenyl group having 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 having not more than four carbon atoms; R² represents any group defined by R¹ above, a phenyl group, a phenyl group substituted with a chlorine atom or an alkyl group having not more than four carbon atoms; X¹ represents a methyl group, a methoxy group or an ethoxy group; X² represents a halogen atom, an alkyl group having not more than six carbon atoms, an alkoxy group having not more than six carbon atoms, an alkoxyalkoxy group having 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. A divinyl compound according to claim 2, wherein R¹ represents an alkyl group having not more than six carbon atoms; R² represents an alkyl group having not more than six carbon atoms or a cyclohexyl group; X² represents a halogen atom, an alkyl group having not more than six carbon atoms, an alkoxy group having not more than six carbon atoms, an alkoxyalkoxy group having 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; X³ represents a chlorine atom, m is 0 and n is 0, 1 or 2. A divinyl compound according to claim 3, wherein R¹ represents a methyl group or an ethyl group; R² represents a methyl group, an ethyl group, an n-propyl group or an iso-propyl group; X² represents a methyl group, an alkoxy group having not more than five carbon atoms and n is 1 or 2. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-diethylaminophenyl)-2-(methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-propoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-iso-propoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-butoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-iso-butoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 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-tetrachlorophthalide. 3,3-bis[2-(p-ethylpropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-methyl-isopropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-ethyl-isopropylaminophenyl)-2- (p-methoxyphenyl)ethenyl] -4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-dipropylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-methylbutylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-ethylbutylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-diethylaminophenyl)-2-(p-ethoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 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-tetrachorophthalide. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrabromophthalide. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-iso-pentyloxyphenyl)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-methylethylaminophenyl)-2-(p-ethoxyphenyl)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-dimethylaminophenyl)-2-(p-ethylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-dimethylaminophenyl)-2-phenylethenyl]-4,5,6,7-tetrachlorophthalide. 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-methylcyclohexylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-5,6-dichloro-4,7-dibromophthalide. 3,3-bis[2-(p-methylmethoxyethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-methylallylaminophenyl)-2-(p-methylphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide. 3,3-bis[2-(p-dimethylamino-phenyl)-2-[p-(p-methoxyphenoxy)phenyl] ethenyl]-4,5,6,7-tetrachlorophthalide. A process for the preparation of a divinyl compound represented by the formula (I) as defined in any one of the preceding claims, which process comprises condensing an ethylene derivative of formula (2): wherein R¹, R², X¹, X², m and n are as defined in claim 1, with a phthalic acid derivative of formula (3) wherein X³ is as defined in claim 1, in a molar ratio of 2:1 and in the presence of a dehydrating agent. A process according to claim 38, wherein the ethylene derivative of formula (2) has been prepared by means of a Grignard reaction between the compounds CH₃MgX and wherein X represents a halogen atom and R¹, R², X¹, X², m and n are as defined in claim 38. A process according to claim 38, wherein the ethylene derivative of formula (2) has been prepared by means of a Grignard reaction between the compounds and wherein X represents a halogen atom and R¹, R², X¹, X², m and n are as defined in claim 38. A process according to claim 38, wherein the ethylene derivative of formula (2) has been prepared by means of a Grignard reaction between the compounds and wherein X represents a halogen atom and R¹, R², X¹, X², m and n are as defined in claim 38. A recording material incorporating, as a chromogenic agent, a divinyl compound represented by the formula (I) as claimed in any one of claims 1 to 37 or which has been prepared by a process as claimed in any one of claims 38 to 41. A recording material according to claim 42, which is a pressure-sensitive recording paper wherein the divinyl compound is encapsulated in solution within microcapsules present on a face of a paper sheet and an opposing face of another paper sheet is coated with a developer. A recording material according to claim 42, which is a heat-sensitive recording paper wherein a mixture comprising the divinyl compound, a binder and a developer coats a face of a paper sheet. Use as a chromogenic agent of a divinyl compound represented by the formula (I) as claimed in any one of claims 1 to 37 or which has been prepared by a process as claimed in any one of claims 38 to 41. A recording material according to any one of claims 42 to 44 incorporating at least two said divinyl compounds. A recording material according to any one of claims 42 to 44 or 46, further comprising an additional chromogenic agent having the fundamental skeleton of 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, triamino-fluorenephthalide or tetraaminodivinylphthalide.

Inventors: FUJINO, YOSHIHARU, GENDAI, KAZUHIKO 6-1-1106 MUKAIJIMA-DANCHI, KAWAI, HAJIME, NIEDA, SEIICHI 205 RUMIERU-NISHIKYOGOKU, SHIMIZU, YOUJI, TSUNEMITSU, KATSUHIKO
Applicants: YAMADA CHEMICAL CO., LTD.
Application year: 1987
Main classification: C07D307
IPC codes: C07D405, B41M5, C07D455, C07D307