JP2824310B2 - Method for producing aqueous developer and pressure-sensitive copying paper - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an aqueous developer dispersion and a pressure-sensitive copying paper obtained by applying a coating liquid containing the same and having excellent light fastness.

[Background Art] A pressure-sensitive copying paper is provided with a color former capsule composition mainly composed of microcapsules containing an oily substance in which an electron-donating organic color former (hereinafter simply referred to as a color former) is dissolved. An upper paper coated on one side and a developer composition mainly composed of an electron-accepting color developer (hereinafter simply referred to as a color developer) that forms a color when contacted with the color former on one side of the support. There are various sheets such as middle paper coated with the color former capsule composition on the opposite side, and lower paper coated only with the developer composition on one side of the support. Generally, upper paper-lower paper, or upper paper It is practically used as a copy set by combining paper-medium paper-lower paper in this order. In addition, a self-coloring type pressure-sensitive copying paper in which a color developing agent and a color developing agent are applied on the same surface of a support to enable pressure-sensitive copying with one sheet is also known as one form thereof.

As the color developer, clays such as acid clay, activated clay, attapulgite, zeolite and bentonite, and phenol polymers such as phenol-aldehyde polymers and phenol-acetylene polymers are known. However, when the above-mentioned clays are used as a color developer, the clays adsorb substances in the air during the long-term storage, and the color-forming ability is significantly reduced. It has the disadvantage of discoloration or fading, and has the disadvantage that the print density is extremely reduced when it is exposed to water. On the other hand, the phenolic polymer has the drawbacks of poor light fastness of printing and yellowing of the color developer layer caused by exposure treatment. For this reason, substituted salicylates having excellent performances in various aspects have been attracting attention instead of the acidic substances as described above.

That is, the pressure-sensitive copying paper using the substituted salicylate hardly deteriorates in coloration ability even after long-term storage. Colored prints are relatively unlikely to be discolored or faded even after the date and time. When a substituted salicylate which is hardly soluble in water is used, the print density hardly decreases even if it is exposed to water. The developer layer has an advantage that yellowing hardly occurs even after exposure treatment. Further, the coloring ability is very high. It has excellent performance in various aspects, such as little change in print density and coloration ability even when treated for several hours at 100 ° C. or higher.

Thus, the performance of pressure-sensitive copying paper was greatly improved by using a substituted salicylate as a color developer instead of the color developer.

However, even in pressure-sensitive copying paper using a substituted salicylate, a phenomenon in which the copied image is faded when the printing paper after printing is exposed to direct sunlight is observed, and further improvement in light resistance is desired. It is the current situation.

"Problems to be Solved by the Invention" It is an object of the present invention to solve the above problems and to provide a pressure-sensitive copying paper having excellent light fastness.

"Means for Solving the Problems" The present invention provides a compound represented by the general formula [I]: [In the formula [I], R ₁ , R ₂ , R ₃ , and R ₄ may be the same or different, and may be a hydrogen atom, a halogen atom, a carbon atom having 1 to 15 carbon atoms.
Or alkyl, cycloalkyl, phenyl, nucleus-substituted phenyl, aralkyl or nucleus-substituted aralkyl groups, and _one of R ₁ , R ₂ , R ₃ , and R ₄ Two may combine to form a ring. n is a number of 1 or more, and M is magnesium, calcium, zinc, aluminum, iron, cobalt, nickel or a basic ion thereof. And a developer represented by the formula (II) and / or the compound represented by the general formula (III), which comprises a nucleus-substituted salicylate as a main component, dissolved in an organic solvent. This is a process for producing an aqueous color developer dispersion obtained by emulsifying and dispersing under heating or non-heating, and then heating this dispersion to remove an organic solvent by distillation.

(In the formula (II), R ₅ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a phenyl group, a nucleus-substituted phenyl group, an aralkyl group, or a nucleus-substituted aralkyl group. .

R ₆ is an alkyl group, an alkyl group having a substituent, a cycloalkyl group, an aryl group, a monoester residue of a diol having 12 or less carbon atoms, a monoester residue of a polyethylene glycol which may have a substituent, a substituent A monoester residue of polypropylene glycol which may have a substituent or a monoester residue of polybutylene glycol which may have a substituent. ] [In formula [III], R ₇ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a phenyl group, a nucleus-substituted phenyl group, an aralkyl group, or a nucleus-substituted aralkyl group.

R ₈ is an alkylene group which may have a substituent, a diester residue of polyethylene glycol which may have a substituent,
It represents a diester residue of polypropylene glycol which may have a substituent or a diester residue of polybutylene glycol which may have a substituent. The present invention is also a method for producing an aqueous color developer dispersion in which the volume average particle diameter of the color developer in the aqueous color developer dispersion is 5 μm or less.

Further, the present invention is a pressure-sensitive copying paper obtained by applying a coating liquid containing the above-described aqueous developer dispersion to a support.

"Action" Although the reason why pressure-sensitive copying paper having excellent light fastness can be obtained in the present invention is not necessarily clear, the general formulas (II) and (III)
It is considered that one of the causes of the compound represented by is that it has a function as an ultraviolet absorber. However, simply adding the compound represented by the general formula [II] and / or [III] to the developer-containing layer cannot provide a sufficient effect, and the developer dispersion is prepared by the above-described production method. Since an extremely excellent effect is obtained when the composition is applied to a support, it is considered that the use of an organic solvent in the process of preparing a dispersion plays an important role.

Each of the substituted salicylates represented by the general formula [I] has excellent color developing ability, and typical examples thereof include 3-methyl-5- (iso) nonyl salicylic acid and 3-methyl-5-
(Iso) dodecyl salicylic acid, 3-methyl-5- (iso) pentadecyl salicylic acid, 3-methyl-5- (α-
Methylbenzyl) salicylic acid, 3-methyl-5- (α,
α-dimethylbenzyl) salicylic acid, 3,5-disecondary butylsalicylic acid, 3,5-ditert-butyl-6-
Methylsalicylic acid, 3-tert-butyl-5-phenylsalicylic acid, 3,5-ditertiaryamylsalicylic acid,
3-cyclohexyl-5- (iso) nonylsalicylic acid,
3-phenyl-5- (iso) nonylsalicylic acid, 3-
(Α-methylbenzyl) -5- (iso) nonylsalicylic acid, 3-isopropyl-5- (iso) nonylsalicylic acid, 3- (iso) nonylsalicylic acid, 3- (iso) nonyl-5-methylsalicylic acid, 3- ( Iso) nonyl-5-
Cyclohexylsalicylic acid, 3- (iso) nonyl-5-
Phenylsalicylic acid, 3- (iso) nonyl-5- (α-
Methylbenzyl) salicylic acid, 3- (iso) nonyl-5
-(4, α-dimethylbenzyl) salicylic acid, 3- (iso) nonyl-5- (α, α-dimethylbenzyl) salicylic acid, 3- (α, α-dimethylbenzyl) -5- (iso) nonylsalicylic acid, 5 -(Iso) nonylsalicylic acid, 3- (iso) nonyl-6-methylsalicylic acid, 3-
Tert-butyl-5- (iso) nonylsalicylic acid, 3,
5-di (iso) nonylsalicylic acid, 3- (iso) dodecylsalicylic acid, 3- (iso) dodecyl-5-methylsalicylic acid, 3- (iso) dodecyl-6-methylsalicylic acid, 3-isopropyl-5- (iso) Dodecylsalicylic acid, 3- (iso) dodecyl-5-ethylsalicylic acid, 5
-(Iso) dodecyl salicylic acid, 3- (iso) pentadecyl salicylic acid, 3- (iso) pentadecyl-5-methyl salicylic acid, 3- (iso) pentadecyl-6-methyl salicylic acid, 5- (iso) pentadecyl salicylic acid, 3 ,
5-dicyclohexylsalicylic acid, 3-cyclohexyl-5- (α-methylbenzyl) salicylic acid, 3-phenyl-5- (α-methylbenzyl) salicylic acid, 3-phenyl-5- (α, α-dimethylbenzyl) salicylic acid,
3- (α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl) -5-methylsalicylic acid, 3- (α-methylbenzyl) -6-methylsalicylic acid, 3- (α-methylbenzyl) -5-phenyl Salicylic acid, 3,5-di (α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl) -5- (α, α-dimethylbenzyl) salicylic acid, 3- (α-methylbenzyl) -5-bromosalicylic acid, 3- (α, 4-dimethylbenzyl) -5-methylsalicylic acid, 3,5-di (α, 4-dimethylbenzyl) salicylic acid, 3- (α, α-dimethylbenzyl) -5-methylsalicylic acid, 3- ( α, α-dimethylbenzyl) -6
Methyl salicylic acid, 3,5-di (α, α-dimethylbenzyl) salicylic acid, 5- (4-mesitylmethylbenzyl)
Such as salicylic acid, benzylated styrenated salicylic acid, 2-hydroxy-3- (α, α-dimethylbenzyl) -1-naphthoic acid or 3-hydroxy-7- (α, α-dimethylbenzyl) -2-naphthoic acid. Valent metal salts. Specific examples of the polyvalent metal include magnesium, calcium, zinc, aluminum, iron, cobalt, nickel and the like. These may be used alone or as a mixture.

In addition, (iso) alkyl shows isoalkyl or normal alkyl. Further, the isononyl group, the isododecyl group and the isopentadecyl group are defined as substituents generated by addition of propylene trimer, propylene tetramer or 1-butene trimer and propylene pentamer, respectively.

Some of these substituted salicylates are crystalline by themselves, and their softening points also vary. In order to prepare a non-crystalline developer having a preferable softening point, the developer is appropriately mixed and adjusted to obtain desired physical properties.

If the softening point of the developer is too low, the developer applied and dried on the paper surface penetrates and transfers between the paper fibers to lower the color density, and the aqueous dispersion of the developer is also easily coagulated, and the Lack of storage stability over time.

On the other hand, if the softening point of the color developer is extremely high, it hardly exhibits self-adhesion when coated and dried on the paper surface, so a large amount of adhesive must be used to fix it to the paper surface. In such a case, the adhesive may form a film to prevent the transfer of the dye-dissolving oil present in the microcapsules, and the color developing ability may be slightly inferior.

For these reasons, the softening point of the developer is preferably 20 ° C. or higher, more preferably about 30 ° C. to 85 ° C.

As a method of adjusting the softening point of the developer to a preferable temperature, first, a developer having a different softening point is mixed, and in order to lower the softening point of the developer, the softening point is adjusted. Adding a reducing substance, such as a metal salt of a fatty acid, a trialkylphenol, a trialkylalkylphenol or a styrene oligomer, and thirdly, a substance that increases the softening point of a developer having a softening point that is too low, such as polystyrene , Poly-α-methylstyrene or petroleum resin. The mixing ratio is not particularly limited.

In addition, the softening point in the present invention means a softening temperature in a state where a color developer contains equilibrium moisture in water. Usually, it is about 50 ° C. lower than the softening point in a dry state.

Among the compounds represented by the general formula (II), although not particularly limited, the general formula (I) in which R ₆ is a monoester residue of polyethylene glycol which may have a substituent.
V] is preferred.

(In the formula (IV), R ₉ and R ₁₀ may be the same or different, and include a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a phenyl group, a phenyl group having a nucleus, and an aralkyl group. And a nucleus-substituted aralkyl group. m represents an integer of 1 or more. M is not particularly limited, but is usually from 1
An integer of about 100 is desirable. Specific examples of the compound represented by the general formula [IV] include compounds in which R ₉ and R ₁₀ are shown in Table 1.

When R ₆ is an alkyl group among the compounds represented by the general formula [II], those having 18 or less carbon atoms are preferable. R ₆
Examples of the monoester residue of a diol having 12 or less carbon atoms include a 5-hydroxypentyl group and an 8-hydroxyoctyl group, and examples of the alkyl group having a substituent include a phenoxyethyl group.

Although not particularly limited among the compounds represented by the general formula (III), a general formula (v) in which R ₈ is a diester residue of polyethylene glycol which may have a substituent
The compound represented by is preferred.

[(V) In the formula, R ₁₁ and R ₁₂ may be the same or different, and represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a phenyl group,
The nucleus-substituted phenyl group, aralkyl group, or nucleus-substituted aralkyl group is shown. p represents an integer of 1 or more. However, p is not particularly limited, but is usually from 1
An integer of about 100 is desirable.

Specific examples of the compound represented by the general formula [v] include R ₁₁ and R
Compounds of which ₁₂ is shown in Table 2 are listed.

When R ₈ is an alkylene group which may have a substituent among the compounds represented by the general formula [III], an alkylene group having 12 or less carbon atoms is preferable.

The combination ratio of the compound represented by the general formula [II] and / or the general formula [III] is variously selected depending on the purpose of use of the color developer, and is not particularly limited. 100 parts by weight of the substituted salicylate represented by the general formula [I] is preferable in terms of dry weight, since the resulting coloring paper for pressure-sensitive copying paper may cause a decrease in the color developing performance or yellowing of the colorant-containing layer. 0.05 to 20 parts by weight, more preferably about 0.1 to 10 parts by weight, of the compound represented by the general formula [II] and / or the general formula [III] is contained in the coating solution for coloring paper.

In the present invention, the organic solvent dissolving the color developer and the compound represented by the general formula [II] and / or the general formula [III] has relatively low solubility in water and good solubility of the color developer. And various properties such as a low boiling point and a difficulty in undergoing a chemical change during the preparation of the dispersion.

Specific examples of this include benzene, toluene, xylene, chloroform, carbon tetrachloride, trichloroethane,
Examples thereof include chlorobenzene, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, butanol, amyl alcohol, and methyl tert-butyl ether.

The amount of the organic solvent used is appropriately adjusted depending on the size of the target dispersed particles, and the amount is 5 to 100 parts by weight of the developer.
It is desirable to adjust the amount within a range of about 00 parts by weight or less.

When the organic solvent solution thus obtained is emulsified and dispersed in an aqueous medium with or without heating, it is preferable that the aqueous medium contains an emulsifier. As emulsifiers, alkali salts of polyvinyl alcohol or alkyl sulfate,
Low molecular weight anionic surfactants such as alkali salts of alkyl benzene sulfonic acid, anionic natural polymers such as gum arabic, acrylic acid polymer, vinyl benzene sulfonic acid polymer, acrylic acid / acrylamide copolymer, ethylene / anhydride An alkaline salt of an anionic polymer such as a maleic acid copolymer may be used. These may be used in combination of two or more.

The aqueous dispersion of the color developer thus prepared is subjected to heat treatment to remove the organic solvent by distillation to prepare a color developer aqueous dispersion composed of spherical particles.

The obtained aqueous developer dispersion may be subjected to a wet pulverization treatment, if necessary. Examples of the fine pulverizer include various types of sand mill type pulverizers using a pulverizing medium such as a ball mill, a pebble mill, a sand grinder, a cobol mill, an attritor, a dyno mill, and a three-roll mill.
High-speed impeller disperser, high-speed stone mill, high-speed grinding machine such as high-speed impact mill, etc., and the like, but in consideration of ease of processing condition setting, crushing efficiency, etc., a sand mill-type crusher and a high-speed impeller disperser are preferable. Among them, a sand mill type pulverizer is more preferable.

If the volume average particle size of the developer particles in the dispersion exceeds 5 microns, the distribution on the paper surface becomes uneven during coating, causing a lack of a recorded image, or the speed of developing a recorded image in a cold region. And the initial coloring may be poor. On the other hand, if the average particle diameter is smaller than 0.3 μm, the particles easily penetrate between the paper fibers, causing a loss of the color developing effect. Even if the particles are made finer than that, there is no advantage. Therefore, the preferred range of the average particle size of the developer particles is 0.3 to 5
Microns, a more preferred range is 0.6 to 3 microns. In general, the concentration of the developer in the aqueous dispersion is usually as high as 10% or more, and a preferable upper limit is about 55%. Such a high concentration not only reduces the transportation cost, but also makes it possible to prepare a high-concentration coating liquid, thereby increasing the drying efficiency in the coating process and improving the quality of the obtained color paper for pressure-sensitive copying paper. Can also be expected.

In the coating solution for forming the color developer layer of the pressure-sensitive copying paper, the thus obtained dispersion is usually further added as an adhesive, for example, starch, casein, gum arabic, carboxymethylcellulose, polyvinyl alcohol, styrene. Butadiene copolymer latex, vinyl acetate-based latex, etc. are blended. In addition, inorganic pigments such as zinc oxide, magnesium oxide, titanium oxide, aluminum hydroxide, calcium carbonate, magnesium sulfate, calcium sulfate, and pressure-sensitive copying paper are manufactured. Various auxiliaries known in the field can be appropriately added.

The amount of the developer layer coating solution applied to the support is not particularly limited, but is about ² to 8 g / m ² in terms of dry weight. The thus-prepared coating solution for the developer layer is applied to a high quality paper, a coated paper, a synthetic paper, a film by a usual coating apparatus such as an air knife coater, a blade coater, a roll coater, a size press coater, a curtain coater, a short dwell coater, and the like. Etc., and finished as a color paper for pressure-sensitive copying paper.

In addition, the method of the present invention is a self-coloring method having a developer layer and a color former layer on the same surface of a support, or having a mixed coating layer of a developer coating liquid and a coating liquid containing an encapsulated color former. Of course, the present invention can also be applied to a type pressure-sensitive copying paper (so-called self-contained type).

"Examples" Examples and comparative examples are described below to further clarify the effects of the present invention, but the present invention is not limited to these. In the examples, "parts" and "%" represent "parts by weight" and "% by weight", respectively, unless otherwise specified.

Example 1 2000 g of water and 400 g of zinc sulfate (heptahydrate) are placed in a 20,000 ml stainless steel cylindrical container equipped with a stirrer and a thermometer and dissolved therein. To this is added 8500 g of a 10% aqueous solution of sodium 3,5-di (α-methylbenzyl) salicylate while stirring the contents vigorously. By the double decomposition, the inside of the container immediately becomes a thixotropic liquid. Here, a mixture of 150 g of a copolymer of α-methylstyrene and styrene (copolymerization ratio; 40 to 60 mol%, average molecular weight: about 1500) and compounds 1-1 and 2-1 (see Tables 1 and 2) , Mixing ratio 50:50) 800 g of methyl isobutyl ketone solution containing 25 g are added in a short time. Since the fluidity of the thixotropic-dropped contents gradually improves, when the contents easily flow, the container is heated to a temperature of 75 ° C. and allowed to stand. The aqueous phase is separated into the upper layer and the oil phase is separated into the lower layer.
Transfer to 5000ml hard glass beaker. This further
600 g of water, 2.5 g of sodium carbonate, 500 g of a 5% aqueous solution of polyvinyl alcohol (degree of saponification; 98%, degree of polymerization: about 1700) and a copolymer of ethyl acrylate and acrylamide (copolymerization ratio: 13 to 87 mol%, degree of polymerization About 400) 25% aqueous solution
Add 60 g and homomixer (Model M, manufactured by Tokushu Kika Kogyo Co., Ltd.) in the range of 35 ° C to 40 ° C, 8800 to 9000 per minute
An oil-in-water type emulsion is obtained by performing an emulsification operation at a number of rotations of 20 minutes. This is transferred to a 10,000 ml hard glass three-necked flask equipped with a stirrer, a thermometer, and a distillation port, and 1100 g of water is further added. The flask is heated and boiled while slowly stirring the contents. About 640 g of methyl isobutyl ketone and about water from the distillation port
Upon removal of 640 g, the contents are an emulsion of 39% total solids containing little methyl isobutyl ketone. The average particle diameter of the obtained developer-dispersed particles was 1.9 μm. The softening point of the dispersed phase is 75 ° C.

(Preparation of developer coating solution)

18 parts of the 39% developer dispersion obtained by the above treatment, 93 parts of calcium carbonate and 100 parts of water were mixed and dispersed, and 50 parts of a 10% aqueous solution of polyvinyl alcohol as a binder were further added.
% Of carboxy-modified SBR latex (SN-307, manufactured by Sumitomo Nogatack Co., Ltd.) was mixed and dispersed to prepare a developer coating solution.

[Manufacture of color-developed paper for pressure-sensitive copying paper]

5 g of dry weight of the above developer coating solution on one side of 40 g / m ² base paper
/ m ² and dried to obtain a color-developed paper for pressure-sensitive copying paper.

Example 2 In Example 1, compounds 1-2 and 2-2 (see Tables 1 and 2) were used instead of compounds 1-1 and 2-1 (see Tables 1 and 2). A developer aqueous dispersion was prepared in the same manner as in Example 1 except that the above procedure was repeated.

The average particle diameter of the obtained developer-dispersed particles was 2.0 μm.

Next, this aqueous dispersion was treated with a sand grinder (Igarashi Kikai Co., Ltd., MODEL NO, OSG-8G) under the condition of 2 kg per minute to prepare a developer dispersion having an average particle size of 1.9 μm. Thereafter, a color-developed paper for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Example 3 In Example 1, compounds 1-3 and 2-3 (see Tables 1 and 2) were used instead of compounds 1-1 and 2-1 (see Tables 1 and 2). A developer aqueous dispersion was prepared in the same manner as in Example 1 except that the above procedure was repeated. The average particle diameter of the obtained developer-dispersed particles was 1.6 μm.

Thereafter, a color-developed paper for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Example 4 In Example 1, compounds 1-4 and 2-4 (see Tables 1 and 2) were used instead of compounds 1-1 and 2-1 (see Tables 1 and 2). A developer aqueous dispersion was prepared in the same manner as in Example 1 except that the above procedure was repeated.

The average particle diameter of the obtained developer-dispersed particles was 1.9 μm.

Thereafter, a color-developed paper for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Example 5 In Example 2, compounds 1-5 and 2-5 (see Tables 1 and 2) were used instead of compounds 1-2 and 2-2 (see Tables 1 and 2). A developer aqueous dispersion was prepared in the same manner as in Example 2 except that the procedure was repeated. The average particle size of the obtained developer-dispersed particles was 1.7 μm.

Thereafter, a color-developed paper for pressure-sensitive copying paper was obtained in the same manner as in Example 2.

Example 6 200 g of zinc 3-isododecylsalicylate (softening point 43 ° C.)
And 295 g of zinc 3,5-di (α-methylbenzyl) salicylate
Is dissolved in 400 g of toluene at 50 ° C. to prepare a toluene solution. To this toluene solution, 13 g of a mixture of compounds 1-1 and 2-1 (see Tables 1 and 2; mixing ratio 50:50) is added and dissolved.

Separately, in a 3000 ml stainless steel beaker, 600 g of water, 2.5 g of sodium carbonate, 100 g of a 25% aqueous solution of a copolymer of ethyl acrylate and acrylamide (copolymerization ratio: 13 to 87 mol%, degree of polymerization: about 400) 35 ℃
Homomixer (Model M, manufactured by Tokushu Kika Kogyo Co., Ltd.) at a speed of 8800 to 9000 rpm
By performing the emulsification operation for 20 minutes, an oil-in-water emulsion is obtained. This is transferred to a 10,000 ml hard glass three-necked flask equipped with a stirrer, a thermometer, and a distillation port, and 1000 g of water is further added. Then, the flask is heated to boiling while slowly stirring the contents. When about 320 g of toluene and about 340 g of water are taken out from the distillation port, the content becomes an emulsion having a total solid content of 39% containing little toluene. The average particle size of the obtained developer-dispersed particles was 2.1 μm.

Thereafter, a color-developed paper for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Comparative Example 1 In Example 1, instead of compounds 1-1 and 2-1 (see Tables 1 and 2), 2- (3,5-di-tert-butyl-2-) which is an ultraviolet absorber was used. A developer aqueous dispersion was prepared in the same manner as in Example 1 except that 25 g of (hydroxyphenyl) benzotriazole (trade name: TINUVIN 320, manufactured by CIBA-GEIGY) was used.

The average particle diameter of the obtained developer-dispersed particles was 1.9 μm.

Thereafter, a color-developed paper for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Comparative Example 2 In Example 1, an ultraviolet absorbent 2- (3,5-di-t-) was used instead of the compounds 1-1 and 2-1 (see Tables 1 and 2).
Butyl-2-hydroxyphenyl) -5-chlorobenzotrial (trade name: TINUVIN 327, manufactured by CIBA-GEIGY) 25 g
A developer aqueous dispersion was prepared in the same manner as in Example 1 except that

The average particle diameter of the obtained developer-dispersed particles was 1.9 μm.

Thereafter, a color-developed paper for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Comparative Example 3 Instead of compounds 1-2 and 2-2 (see Tables 1 and 2) in Example 2, 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2- n-butylmalonic acid-bis (1,
2,2,6,6-pentamethyl-4-piperidyl) (trade name TIN
A developer aqueous dispersion was prepared in the same manner as in Example 2 except that 50 g of UVIN 144 (manufactured by CIBA-GEIGY) was used.

The average particle diameter of the obtained developer-dispersed particles was 3.2 μm.

Thereafter, a color-developed paper for pressure-sensitive copying paper was obtained in the same manner as in Example 2.

Comparative Example 4 Compounds 1-1 and 2-1 (see Tables 1 and 2) in Example 1 were not dissolved in methyl isobutyl ketone, but dispersed in a 2% aqueous polyvinyl alcohol solution, and pulverized and dispersed by a sand grinder. In the same manner as above, a color developing paper for pressure-sensitive copying paper was obtained except that the resultant was added to a color developer dispersion.

The following 9 quality evaluation tests were conducted on the thus obtained 9 types of color-developed paper for pressure-sensitive copying paper, and the results are shown in Table 3.

[Preparation of upper paper]

Crystal violet lactone is dissolved in alkylated naphthalene, and a capsule coating solution prepared by microencapsulating this oily liquid is coated on one side of high-quality paper with a dry weight of 4 g / m ^2.
And dried to obtain upper paper.

[Preparation of Middle Paper] The same capsule coating solution as the upper paper was applied to the base paper surface of the color-developed paper for pressure-sensitive copying paper so as to have a dry weight of 4 g / m ^2, and dried to obtain a middle paper.

Initial color development test The color developing paper and the upper paper were left in an atmosphere of 5 ° C for 10 hours.
Next, the coated surfaces of the colored paper and the upper paper are opposed to each other, and the color is developed by a dropping type color tester (weight: 150 g, height: 20 cm) in an atmosphere of 5 ° C. Seconds later,
One day later, the color density was measured.

Coated faces the light resistance test developing colored paper and the upper paper was is overlaid so as to face, 120 kg / cm ² of a load to form a color image, D ₀ the value measured color density by a Macbeth color densitometer And Next, the the value of the color density was measured after addressed 10Hrs sunlight was D _1.

The light fastness is defined by the following equation. The closer the value is to 100, the better the light fastness.

"Effects" As is clear from the results in Table 3, the developed paper for pressure-sensitive copying paper obtained in the examples of the present invention had excellent properties in both initial color development and light fastness.

Continued on the front page (72) Inventor Shigeru Oda 1-10-24, Itokaichi, Ibaraki-shi, Osaka Inside the Sanko Development Research Institute (72) Inventor Toranosuke Saito 1-10-24, Itokaichi, Ibaraki-shi, Osaka (56) References JP-A-3-57690 (JP, A) JP-A-3-57687 (JP, A) JP-A-57-191087 (JP, A) JP-A-64-34782 (JP, A) JP-A-63-98483 (JP, A) JP-A-3-215084 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41M 5/124

Claims (3)

(57) [Claims] 1. A compound of the formula [I] [In the formula [I], R ₁ , R ₂ , R ₃ and R ₄ may be the same or different, and may be a hydrogen atom, a halogen atom, an alkyl group having 1 to 15 carbon atoms, a cycloalkyl group, a phenyl group, It is a nucleus-substituted phenyl group, an aralkyl group or a nucleus-substituted aralkyl group, and _two adjacent groups out of R ₁ , R ₂ , R ₃ and R ₄ may combine to form a ring. n is a number of 1 or more, and M is magnesium, calcium, zinc, aluminum, iron, cobalt, nickel or a basic ion thereof. And a developer represented by the formula (II) and / or the compound represented by the general formula (III), which comprises a nucleus-substituted salicylate as a main component, dissolved in an organic solvent. A process for producing an aqueous color developer dispersion obtained by emulsifying and dispersing under heating or non-heating, followed by heating the dispersion and distilling off the organic solvent. (In the formula (II), R ₅ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a phenyl group, a nucleus-substituted phenyl group, an aralkyl group, or a nucleus-substituted aralkyl group. . R ₆ is an alkyl group, an alkyl group having a substituent, a cycloalkyl group, an aryl group, a monoester residue of a diol having 12 or less carbon atoms, a monoester residue of a polyethylene glycol which may have a substituent, a substituent A monoester residue of polypropylene glycol which may have a substituent or a monoester residue of polybutylene glycol which may have a substituent. ] [In formula [III], R ₇ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a phenyl group, a nucleus-substituted phenyl group, an aralkyl group, or a nucleus-substituted aralkyl group. R ₈ has an alkylene group which may have a substituent, a diester residue of polyethylene glycol which may have a substituent, a diester residue of polypropylene glycol which may have a substituent, or has a substituent. Represents a diester residue of polybutylene glycol which may be substituted. ] 2. A process for producing an aqueous developer dispersion wherein the volume average particle diameter of the developer in the aqueous developer dispersion is 5 μm or less. 3. A pressure-sensitive copying paper obtained by applying a coating liquid containing the aqueous developer dispersion according to claim 1 to a support.