JPS6127420B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a dye solution, and more particularly to a method for extremely efficiently producing a hydrophobic organic solvent solution in which a specific diallylmethane derivative is dissolved, which is effective for use in various recording systems such as pressure-sensitive copying paper. Conventionally, general formula [] (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , A, and B are each as described in claim 1.) The diallylmethane derivative represented by the formula Reaction with sulfuric acid in acidic aqueous solution (Beilstein Organische
Chemie Vol. 13, p. 704), Reaction of auramine and sulfinic acid in an acidic aqueous solution (Japanese Unexamined Patent Publication No. 1983-95420)
It is synthesized by reaction in an aqueous medium.
In these synthesis methods in an aqueous medium, co-reactants of sulfuric acid as a raw material are limited to diphenyl carbinol and auramine as mentioned above, and therefore there is a technical problem that the range of raw material sources is narrow. Moreover, in order to obtain a hydrophobic organic solvent solution in which such a diallylmethane derivative is dissolved, a step of once isolating and purifying the synthesized diallylmethane derivative from an aqueous medium is required. In such isolation and purification steps, a decrease in the yield of the synthesized diallylmethane derivative is unavoidable, and there is also the possibility that the diallylmethane derivative may be partially denatured during isolation and purification. The main object of the present invention is to provide a method for efficiently producing a hydrophobic organic solvent solution in which a diallylmethane derivative represented by the general formula [] is dissolved very efficiently and is effectively used in various recording systems such as pressure-sensitive copying paper. The object of the present invention is to provide a highly efficient method for producing a dye solution that is particularly effective as a microcapsule core material for pressure-sensitive copying paper. Such an object of the invention is that the general formula Acidic water containing sulfinic acid and a hydrophilic protective colloid substance represented by the general formula R ₅ −SO ₂ H ……[] is brought into contact with a hydrophobic organic solvent in which the compound represented by the formula R 5 −SO 2 H ………[] By reacting the compound with the sulfuric acid of the general formula [], the compound of the general formula This is achieved by dissolving a diallylmethane derivative represented by the formula in such a hydrophobic organic solvent. (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , A, B, and R ₅ are each as described in claim 1.) The hydrophobic organic solvent used in the present invention is
The solvent must be capable of dissolving the diallylmethane derivative represented by the above general formula [], and it must be a solvent that can dissolve the diallylmethane derivative represented by the above general formula [] or [], and more preferably both compounds. It is more desirable if the solvent can dissolve the . Such organic solvents are appropriately selected depending on the type of diallylmethane derivative to be synthesized and the purpose of use of the obtained dye solution, and include benzene, toluene, xylene, chlorobenzene, anisole, nitrobenzene, alkyl-substituted naphthalene,
Aromatic organic solvents such as diphenylalkane, alkyl-substituted diphenylalkane, alkyl-substituted biphenyl, hydrogenated biphenyl, hydrogenated terphenyl, phthalate, salicylate, and benzoate are preferably used. In particular, aromatic organic solvents having ester groups such as phthalate esters such as dimethyl phthalate and dibutyl phthalate, and salicylate esters such as methyl salicylate, ethyl salicylate, and hexyl salicylate, have a good yield of diallylmethane derivatives, and also produce side reaction products. It is more preferably used because it produces less. The compound used as a starting material in the present invention is a compound represented by the following general formula []. In the formula, A and B each represent a 1,4-arylene group or a substituted 1,4-arylene group. 1,
Examples of the 4-arylene group include 1,4-phenylene group and 1,4-naphthylene group, and 1,4-phenylene group is particularly preferably used.
Further, examples of substituents for the 1,4-arylene group include halogen, alkyl group, alkoxy group, cyano group, substituted amino group, and nitro group. _R1 ,
R ₂ , R ₃ , and R ₄ each represent an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group, an aralkyl group, a substituted aralkyl group, an allyl group, or a substituted allyl group, especially an alkyl group; halogen, alkoxy or a cyano group; aralkyl group; halogen, alkyl group, alkoxy group, aralkyl group, allyl group, cyano group, aralkyl group substituted with a substituted amino group or nitro group; allyl group; halogen, alkyl An allyl group substituted with a group, an alkoxy group, an aralkyl group, an allyl group, a cyano group, a substituted amino group or a nitro group is preferably used. Further, R ₁ and R ₂ and R ₃ and R ₄ may be cyclized with each other to form a heterocycle, and a saturated 5-membered or 6-membered heterocycle is particularly preferably used. Q represents a substituent represented by the general formula -O-X, -S-Y or N< ^Z1 _Z2 , where X, Y, _Z1 , _Z2 each have hydrogen or one or more heteroatoms; Indicates an optionally substituted hydrocarbon group or a substituted hydrocarbon group. Among the substituents represented by X, Y, Z ₁ and Z ₂ , hydrogen; alkyl group; halogen, alkoxy group,
Alkyl group substituted with cyano group or substituted amino group; Aralkyl group; Halogen, alkyl group, alkoxy group, aralkyl group, allyl group, cyano group,
Aralkyl group substituted with substituted amino group or nitro group; Allyl group; Allyl group substituted with halogen, alkyl group, alkoxy group, aralkyl group, allyl group, cyano group, substituted amino group or nitro group is particularly preferably used. , furthermore, Z ₁ and Z ₂ may be cyclized with each other to form a heterocycle, especially the hetero5
Substituents forming a membered ring or a 6-membered ring are preferably used. Specific compounds represented by the above general formula [] include, for example, 4,4'-bis-dimethylamino-benzhydrol, 4,4'-bis-diethylamino-benzhydrol, and 4,4'-bis-dimethylamino-benzhydrol. -dibutylamino-benzhydrol, 4,4'-bis-
Didodecylamino-benzhydrol, 4,4'-
bis-dibenzylamino-benzhydrol,
4,4'-bis-(N-ethyl-Nbenzyl)amino-benzhydrol, 4,4'-bis-dimethylamino-3-methyl-benzhydrol, 4,
4'-bis-dimethylamino-2,2'-dichloro-
Benzhydrol, 4,4'-bis-dimethylamino-3,3'-dimethyl-benzhydrol, 4,
4'-bis-dimethylamino-2,2'-dimethoxy-benzhydrol, 4,4'-bis-dimethylamino-2-acetamino-benzhydrol,
4,4'-bis-dimethylamino-3-benzamino-benzhydrol, 4,4'-bis-dimethylamino-3-nitro-benzhydrol, 2,
4,4'-tris-diethylamino-3-methyl-
Benzhydrol, 4,4'-bis-di(cyanoethyl)amino-benzhydrol, 4,4'-bis-(N-methyl-N-0-chlorobenzyl)amino-benzhydrol, 4,4' -bis-di(p-
methylbenzyl)amino-benzhydrol,
4,4'-bis-(N-ethyl-Nm-nitrobenzyl)amino-benzhydrol, 4,4'-bis-(N-ethyl-N-p-dimethylaminobenzyl)amino-benzhydrol , 4,4'-bis-dimethylamino-benzhydrol-methyl ether, 4,4'-bis-dimethylamino-benzhydrol-ethyl ether, 4,4'-bis-dimethylamino-benzhydrol-isopropyl Ether, 4,4'-bis-dimethylamino-benzhydrol-n-octyl ether, 4,4'-
Bis-dimethylamino-benzhydrol-benzyl ether, 4,4'-bis-dimethylamino-
Benzhydrol-phenethyl ether, 4,
4'-bis-dimethylamino-benzhydrol-
p-Methoxybenzyl ether, 4,4'-bis-
Dimethylamino-benzhydrol-phenyl ether, 4,4'-bis-dimethylamino-benzhydrol-tolyl ether, 4,4'-bis-dimethylamino-benzhydrol-naphthyl ether, 4,4'- Bis-dimethylamine-benzhydrol-biphenyl ether, 4,4'-bis-
Dimethylamino-benzhydrol-cyclohexyl ether, 4,4'-bis-dimethylamino-
Benzhydrol-pyridyl ether, 4,4'-
Bis-dimethylamino-benzhydrol-quinolyl ether, 4,4'-bis-dimethylamino-
Benzhydrol-acetophenone oxime ether, 4,4'-bis-dimethylamino-benzhydrol-4-chloroacetophenone oxime ether, bis-(4,4'-dimethylamino-benzhydryl) ether, bis- (4,4'-bis-
dimethylamino-benzhydryl) ether, bis-(4-piperidinophenyl) carbinol methyl ether, bis-(N-methyl-6-tetrahydroquinolyl) carbinol methyl ether,
bis-(2-methylcarboxy-4-dimethylaminophenyl)carbinol ethyl ether,
4,4'-bis-(N-methyl-N-4-methylcyclohexyl)aminobenzhydrol methyl ether, 4,4'-bis-(N-methyl-N-chloroethyl)aminobenzhydrol benzyl ether, bis -(4,4'-dimethylamino-benzhydryl)-sulfide, bis-(4,4'-dimethylamino-benzhydryl)-disulfide,
4,4'-dimethylamino-benzhydrylamine, 4,4'-diethylamino-benzhydrylamine, N-phenyl-leucoolamine, N-
(2-nitro-phenyl)-leucoolamine, N
-p-tolyl-leucoauramine, N-(2,
4-dimethyl-phenyl)-leucoolamine,
N-α-naphthyl-leucoauramine, carbonyldileucoauramine, p-phenylenedileucoauramine, N-(3-dimethylamino-4-methyl-phenyl)-leucoauramine, [di-phenylene-( 4,4′)]-di-leucoauramine, bis-(4,4′-bis-dimethylamino-benzhydryl)-amine, [3,3′-dimethyl-diphenylene-(4,4′)]-di -Leucoauramine, morpholino-leucoauramine, piperidino-leucoauramine, (N-butyl-N-2,5-dichlorophenyl)-leucoauramine, N-bis-(p
-dimethylaminophenyl)-methyl-octadecylamine, N-bis-(p-dimethylaminophenyl)-methyl-N'-methyl-piperazine,
3,3'-dichloro-4,4'-[N,N'-bis-(tetramethyl-p,p'-diaminodiphenylmethyl)]-diaminodiphenylmethane, N-[bis-
(p-dimethylaminophenyl)-methyl]-bicyclo(2,2,1)-5-heptene-2,3-dicarboximide, N,N'-bis-[bis-
(4,4′-dimethylaminophenyl)-methyl]-
1,6-hexamethylene diamine, [bis-(4,
4'-dimethylaminophenyl)-methyl)-β-octylamine, N-bis-(4-dimethylaminophenyl)-methyl-glycine ethyl ester,
N-bis-(p-dimethylaminophenyl)-methyl-2-chloro-5-trifluoromethylaniline, N-[bis-(p-dimethylaminophenyl)
-Methyl]-2-amino-6-ethoxybenzothiazole, bis-[bis-(p-dimethylaminophenyl)-methyl]-benzotriazole, N,
Examples include N'-bis-[bis-(p-dimethylaminophenyl)-methyl]-1,5-naphthylenediamine. Such compounds are appropriately selected and used depending on the intended use of the obtained dye solution, but in particular, when the substituents A and B in the general formula [] are 1,4-
It is a phenylene group, and R ₁ , R ₂ , R ₃ , and R ₄ are each a C ₁ to C ₄ alkyl group; a benzyl group or a benzyl group substituted with a halogen, a methyl group, a halogenated methyl group, or a nitro group. The compound is particularly preferably selected for use in such applications because it has excellent color development and color recording stability when the resulting dye solution is used in pressure-sensitive copying paper. In the present invention, the sulfinic acid constituting the other coreactant is represented by the following general formula []. R ₅ −SO ₂ H …[] In the formula, R ₅ represents an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group, an aralkyl group, a substituted aralkyl group, an allyl group, or a substituted allyl group. Specific examples of the sulfinic acid represented by the above general formula [] include ethylsulfinic acid,
Butylsulfinic acid, dodecanesulfinic acid, benzylsulfinic acid, benzenesulfinic acid, p
-Chlorbenzenesulfinic acid, p-toluenesulfinic acid, p-dodecanylbenzenesulfinic acid, p-methoxybenzenesulfinic acid, p-ethoxybenzenesulfinic acid, O-cyanobenzenesulfinic acid, p-acetate Aminobenzenesulfinic acid, 3-chloro-4-methylbenzenesulfinic acid, 2,5-dichlorobenzenesulfinic acid, 3,4-dichlorobenzenesulfinic acid,
2,4-dimethylbenzenesulfinic acid, 3,4
-dimethylbenzenesulfinic acid, 2-methyl-
5-isopropylbenzenesulfinic acid, 2-methoxy-5-methylbenzenesulfinic acid, 3-
Nitro-4-methylbenzenesulfinic acid, 2-
Cyano-5-methylbenzenesulfinic acid, 2-
Cyano-3-methyl-5-chlorobenzenesulfinic acid, α-naphthylsulfinic acid, β-naphthylsulfinic acid, 8-nitronaphthalenesulfinic acid, 4-chlornaphthalenesulfinic acid, anthracenesulfinic acid, β-anthraquinone sulfinic acid, p-biphenyl sulfinic acid, 1,
Examples include 2,3,4-tetrahydronaphthalenesulfinic acid. Among the sulfinic acids represented by the above general formula [], sulfinic acids in which the substituent R ₅ is an allyl group or an allyl group substituted with a halogen, an alkyl group, an alkoxy group, a substituted amino group, or a nitro group are more preferable. Preferably used, especially substituent R ₅ is a phenyl group;
Sulfinic acid, which is a phenyl or naphthyl group substituted with a halogen, a _C1 - _C4 alkyl group, a _C1 - _C2 alkoxy group, or a nitro group, is most preferably used in the present invention. In the present invention, acidic water containing sulfinic acid refers to an aqueous medium in which free sulfinic acid exists, and such acidic water refers to sulfinic acid represented by the general formula [] or its alkali in the aqueous medium. By supplying a salt such as a salt, an alkaline earth salt, an ammonium salt or an amine salt, and maintaining the pH of the aqueous medium in the range of 7 or less, preferably in the range of 1 to 6, more preferably in the range of 2 to 5.5. It is prepared by The method of the present invention involves contacting acidic water containing sulfuric acid represented by the general formula [] with a hydrophobic organic solvent in which the compound represented by the general formula [] as described above is dissolved; The present invention relates to a method for obtaining a dye solution in which a diallylmethane derivative represented by the general formula [] is dissolved by reacting the sulfuric acid with a sulfuric acid represented by the general formula [], and in particular, it relates to a method for obtaining a dye solution in which a diallylmethane derivative represented by the general formula [] is dissolved. It has an extremely important feature in that it is included. That is, by containing a hydrophilic protective colloid substance in acidic water, not only the stability of the acidic water containing sulfinic acid is improved, but also, in the reaction between the compound of general formula [] and sulfinic acid, The completely unexpected effect that side reactions are extremely significantly suppressed and the diallylmethane derivative represented by the general formula [] can be obtained efficiently in an extremely short period of time is also obtained. As the hydrophilic protective colloid substance used in the present invention, various conventionally known hydrophilic protective colloid substances can be appropriately used as long as they can be stably dissolved in the above-mentioned acidic water containing sulfinic acid. Anionic colloidal substances are most preferably used because their effects are particularly remarkable. Specific examples of such anionic colloid substances include natural polymers such as gum arabic, pectic acid, gum tragacanth, almond gum, sodium alginate, carrageenan, and agar, carboxymethyl cellulose, sulfated cellulose, sulfated methyl cellulose, and carboxylic acid. Semi-synthetic polymers such as methylated starch and phosphorylated starch, maleic anhydride (including hydrolyzed) copolymers, acrylic acid polymers and copolymers, methacrylic acid polymers and copolymers, itaconic acid polymers and copolymers, crotonic acid polymers and copolymers, vinylbenzenesulfonic acid polymers and copolymers,
Examples include synthetic polymers such as carboxy-modified polyvinyl alcohol and phosphoric acid polyvinyl alcohol. The above-mentioned effects of the hydrophilic protective colloid can be achieved by adding 0.01% by weight or more of the hydrophilic protective colloid in acidic water, more preferably
It is noticeable when the content is 0.1% by weight or more. The upper limit of the amount to be used is appropriately determined in consideration of the type of colloid substance used, the conditions of the reaction system, economic efficiency, etc., but it is particularly preferably used in the range of approximately 0.5 to 5% by weight. In the reaction system of the present invention consisting of a hydrophobic organic solvent and an aqueous medium, the amount of sulfinic acid represented by the general formula It is desirable that the amount is 1 mole or more per mole of the compound represented by the general formula []. However, considering economic efficiency, it is better to avoid mixing more than 5 moles, and 1 to 3 moles, more preferably 1 to 3 moles.
Contains 1.5 mol. In addition, in the method of the present invention, it is desirable that the contact between the hydrophobic organic solvent and the above-mentioned specific acidic water be carried out efficiently, for example, by introducing an apparatus such as a blender, homomixer, ball mill, sand mill, attritor, etc. Increasing the contact area is a preferred embodiment in terms of promoting reaction and increasing efficiency. Furthermore, the temperature of the reaction system is adjusted appropriately depending on the reaction efficiency, etc., but in general, reactions at temperatures above 100°C increase side reactions and lead to a decrease in yield. It is desirable to adjust within a range. Thus, according to the method of the present invention, the general formula []
A dye solution in which the diallylmethane derivative represented by is dissolved extremely efficiently can be obtained efficiently. It is of course possible to isolate and purify the produced diallylmethane derivative by conventional methods such as recrystallization, but it is also possible to select a solution according to the use of the dye solution, which can obtain a hydrophobic organic solvent for the reaction system. By doing so, the resulting dye solution can be applied directly to its intended use, eliminating not only the cost of isolation and purification, but also the loss of product efficiency and loss associated with the isolation and purification process. The disadvantages of conventional methods such as deterioration are also avoided. In particular, the diallylmethane derivative represented by the general formula [] is used as an electron-accepting basic chromogen compound that develops color when it comes into contact with an electron-accepting acidic substance, and is mainly used in various recording systems such as pressure-sensitive copying paper. Ori,
Moreover, in such applications, the chromogen compound is often used in a solution state, so the dye solution obtained by the method of the present invention can be used as it is as a core material for microcapsules.
In particular, the aqueous medium in the method of the present invention can be used as it is as an aqueous medium in the production of microcapsules, and the method of the present invention has the effect of streamlining various complicated steps at once. Furthermore, hydrophilic protective colloid substances blended into the aqueous medium not only improve the yield of the dye solution, but also contribute to the encapsulation process itself; for example, maleic anhydride copolymers, carboxy-modified Certain anionic colloidal substances such as polyvinyl alcohol can be encapsulated using urea/formaldehyde resin, melamine/formaldehyde resin, etc. as a wall film (Japanese Patent Application Laid-Open No. 51-9079, JP-A No. 53-84881, patent application). Polyvinyl alcohol, gum arabic, etc. can be used as a system modifier for polyvinyl alcohol, gum arabic, etc. using an encapsulation method using isocyanate resin as a wall film (Japanese Patent Publication No. 42-771, Japanese Patent Publication No. 140805, etc.).
13508 etc.), and can act more effectively when applied to such encapsulation methods. The present invention will be explained in more detail with reference to Examples below, but it is of course not limited thereto. In addition, unless otherwise specified, parts and percentages in examples
indicate weight parts and weight %, respectively. Example 1 A four-necked flask equipped with a stirrer, a thermometer, and a cooling tube Ethylene/maleic anhydride copolymer (trade name)
Hydrolyzate 1 of EMA-31 (manufactured by Monsanto)
% aqueous solution was added, and 0.10 mol of sodium p-toluenesulfinate was dissolved therein. Next, add 20% caustic soda solution dropwise to adjust the pH to 3.5.
Acidic water containing sulfinic acid was prepared.
While stirring the system, separately prepared 4,4'-bis-
A solution of 0.10 mol of dimethylamino-benzhydrol dissolved in 1 part of dibutyl phthalate was added dropwise. The pH of the aqueous system during the reaction changes in the range of 3.5 to 4.0, and since sulfinic acid is efficiently supplied to the reaction system, the reaction progresses quickly. As confirmed by E (silica gel), a dibutyl phthalate solution of p-toluenesulfinic acid-4,4'-bis-dimethylamino-benzhydrol was obtained, which contained almost no unreacted benzhydrol. For reference, the product obtained from the thus obtained dye solution was isolated and the flocculent crystals obtained by recrystallizing from benzene had a melting point of 18 to 4°C and were red. The target p-
It was toluenesulfinic acid-4,4'-bis-dimethylamino-benzhydrol. Also, the yield is 90
It was %. Example 2 In a ball mill, a solution of 0.10 mol of 4,4'-bis-diethylamino-benzhydrol-methyl ether in 1 part of dibutyl phthalate, pH
1% aqueous solution of a hydrolyzate of ethylene/maleic anhydride copolymer (trade name EMA-31) adjusted to 4.0 and 0.11 mol of benzenesulfinic acid were added, and the mixture was rotated for 30 minutes to react. When the dibutyl phthalate solution obtained in the same manner as in Example 1 was checked, it was confirmed that it was a dye solution in which benzenesulfinic acid-4,4'-bis-diethylamino-benzhydrol was dissolved with high purity. The yield was 92%. Examples 3 to 9 The same procedure as Example 2 was carried out except that the compound represented by the general formula [], sulfinic acid, and hydrophobic organic solvent were changed as shown in Table 1. In all cases, the desired dye was obtained. A solution was obtained efficiently. Furthermore, the yield and melting point of the product isolated and purified in the same manner as in Example 1 are also listed in Table 1.

【table】

【table】

[Table] Examples 10 to 19 The same procedure as in Example 1 was carried out except that the compound represented by the general formula [] was changed as shown in Table 2. In each case, the desired dye solution was efficiently obtained. It was done. Furthermore, the yield and melting point of the product isolated and purified in the same manner as in Example 1 are also listed in Table 2.

【table】

【table】

【table】

[Performance test]

1. Color development The upper and lower sheets are stacked so that the coated surfaces are facing each other, and a load of 100 kg/ ^cm2 is applied for 30 seconds to develop color.The color density on the lower sheet is measured using a spectrophotometer. using magnesium oxide as standard.
Measured at 600 nm and expressed as reflectance. 2 Preservability of color recording As in 1, the upper and lower sheets were stacked, the print was recorded using a typewriter, and the change in print density after processing under the following conditions was visually determined. (a) Light resistance...direct sunlight, 3 hours (b) Heat resistance...100℃, 5 hours (c) Moisture resistance...50℃, 90% RH, 5 hours Example 20 In a stirring mixing container equipped with a heating device, vinyl methyl ether and anhydrous Maleic acid copolymer (trade name)
Gantrez AM−169, manufactured by GAF) hydrolyzate
Add 50 parts of a 10% aqueous solution, 5 parts of urea, 90 parts of water, and 1 part of sodium p-toluenesulfinate, mix and dissolve uniformly, and then adjust the pH to 3.3 with a 20% aqueous sodium hydroxide solution to prepare an aqueous medium for capsule production. . Separately, a solution was prepared by dissolving 1 part of 4,4'-bis-dimethylamino-benzhydrol in 50 parts of dibutyl phthalate, and this solution was added as a capsule core material to the above aqueous medium for capsule manufacturing. It was emulsified and dispersed so that it had a diameter of 4μ. For reference, a portion of the emulsion was taken, the oil was extracted with benzene, and the oil was confirmed using thin layer chromatography.
4,4'-bis-dimethylamino-benzhydrol was obtained with good purity. Next, add 37% formaldehyde aqueous solution to this system.
Add 12.5 parts and heat at 55℃ with gentle stirring.
After heating for an hour, 5 parts of a 10% aqueous solution of resorcinol was added dropwise. The mixture was further maintained at 55°C for 2 hours and then allowed to cool to obtain a capsule dispersion. Pressure-sensitive copying paper was prepared in the same manner as in Examples 1 to 6, except that the capsule dispersion thus obtained was used, and performance tests were conducted in the same manner, and the results are also listed in Table 3. Example 21 In a stirring mixing container equipped with a heating device, 5 parts of anion-modified polyvinyl alcohol (trade name Gosenal T-350, manufactured by Nippon Gosei Kagaku Co., Ltd.), 1 part of p-toluenesulfinic acid, and 140 parts of water were added and mixed uniformly. After dissolving in the solution, the pH of the system was adjusted to 2.0 with 10% hydrochloric acid to prepare an aqueous medium for capsule production. The same dibutyl phthalate solution used in Example 10 was used as a capsule core material and was emulsified and dispersed in this aqueous medium for capsule production so that the average particle size was 4 μm. Separately, a prepolymer aqueous solution was prepared by heating and reacting 50 parts of a 37% formaldehyde aqueous solution adjusted to pH 8.0 with caustic soda and 25 parts of urea at 70°C for 1 hour.
Add 15 parts to the above emulsified dispersion, warm to 60°C with gentle stirring, and add 10%
After dropping 5 parts of resorcinol aqueous solution, the mixture was kept warm for 3 hours. A similar performance test was conducted on the capsule dispersion obtained by cooling, and the results are also listed in Table 3. Furthermore, it was confirmed by thin layer chromatography that the internal phase of the obtained capsule had become the desired dye solution. Example 22 150 parts of a 5% aqueous solution of partially saponified polyvinyl alcohol (trade name PVA-217, manufactured by Kuraray Co., Ltd.) was placed in a stirring mixing container equipped with a heating device, and further,
Dissolve 1 part of sodium p-toluenesulfinate,
It was used as an aqueous medium for manufacturing capsules. Separately, 30 parts of alkylnaphthalene (trade name: KMC Oil, manufactured by Kureha Chemical Co., Ltd.) and dibutyl phthalate.
1 part of 4,4'-bis-dimethylamino-benzhydrol-methyl ether in an oil solution mixed with 10 parts of
A solution of 10 parts of dibutyl phthalate and 7.5 parts of polyvalent isocyanate (trade name: Coronate L, manufactured by Nippon Polyurethane Industries, Ltd.) was prepared and mixed. It was emulsified and dispersed in the medium so that the average particle size was 9 μm. In addition, the aqueous medium during the emulsification process was always adjusted to pH 4 to 5 with hydrochloric acid. Next, the thread was heated at 60° C. for 3 hours and then allowed to cool to obtain a capsule dispersion. The performance test results of the obtained capsule dispersion are also listed in Table 3. Furthermore, thin layer chromatography revealed that the internal phase of the obtained capsule was a dye solution in which the target p-toluenesulfinic acid-4,4'-bis-dimethylamino-benzhydrol was dissolved with high purity. It was later confirmed. As is clear from the results in Table 3, all the pressure-sensitive copying papers obtained by using the dye solutions obtained in the examples of the present invention as capsule core materials had good performance.

【table】

Claims (1)

[Claims] 1. General formula Acidic water containing sulfinic acid and a hydrophilic protective colloid substance represented by the general formula R ₅ −SO ₂ H ……[] is brought into contact with a hydrophobic organic solvent in which the compound represented by the formula R 5 −SO 2 H ………[] By reacting the compound with the sulfuric acid of the general formula [], the compound of the general formula 1. A method for producing a dye solution, which comprises obtaining a solution in which a diallylmethane derivative represented by the following formula is dissolved. [In the formula, A and B each represent a 1,4-arylene group or a substituted 1,4-arylene group, and R ₁ ,
R ₂ , R ₃ , and R ₄ each represent an alkyl group, a substituted alkyl group, a cycloalkyl group, a reactive cycloalkyl group, an aralkyl group, a substituted aralkyl group, an allyl group, or a substituted allyl group. Note that R ₁ and R ₂ and R ₃ and R ₄ can also be cyclized with each other to form a heterocycle. Q represents a substituent represented by the general formula -O-X, -S-Y or [Formula]. (X, Y, Z ₁ and Z ₂ each represent hydrogen or a hydrocarbon group or substituted hydrocarbon group which may have one or more heteroatoms. In addition, Z ₁ and Z ₂ are cyclized with each other. (It is also possible to form a heterocycle.) R ₅ represents an alkyl group, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group, an aralkyl group, a substituted aralkyl group, an allyl group, or a substituted allyl group. 2. The manufacturing method according to claim 1, wherein the hydrophilic protective colloid substance is an anionic colloid substance. 3. The manufacturing method according to claim 1, wherein the hydrophobic organic solvent is an aromatic organic solvent. 4. The manufacturing method according to claim 1, 2 or 3, wherein the dye solution is a dye solution used in microcapsules for pressure-sensitive copying paper.