JP2706751B2 - Developer for pressure-sensitive recording paper and developer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color developer for a pressure-sensitive recording paper and a color developing sheet mainly comprising a polyvalent metal salt of a salicylic acid derivative.

[0002]

2. Description of the Related Art Hitherto, polyvalent metal salts of salicylic acid derivatives have been known as color developers for pressure-sensitive recording paper. In addition, since this developer is generally dispersed in water and applied to the paper surface, it is an aqueous dispersion with excellent handleability at high concentrations and excellent storage stability. It is desirable that the material be excellent in stability, without causing the occurrence of blemishes. Various attempts have been made to cope with this, for example, a composition in which an alkyl-modified polyvinyl alcohol is blended in an organic solvent solution of the salicylic acid derivative polyvalent metal salt (Japanese Patent Laid-Open No. 4-118278). Modified polyvinyl alcohol obtained by copolymerizing alkyl vinyl ether and vinyl acetate in an organic solvent solution of the salicylic acid derivative polyvalent metal salt.
A polyvinyl alcohol having a polymerization degree of 500 or more and a saponification degree of 70% or more is added to an organic solvent solution of the salicylic acid derivative polyvalent metal salt or the like (JP-A-4-164683). Compounded (Japanese Unexamined Patent Publication No.
No. 202388).

[0003]

However, these conventional aqueous developer dispersions are not sufficiently satisfactory in storage stability at a high concentration and stability during preparation of a coating solution.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention.
That is, the present invention comprises a polyvalent metal salt of a salicylic acid derivative (A) and a sulfonic acid group-modified polyvinyl alcohol (B), wherein the salicylic acid derivative in (A) is the total of the following (a), (b) and (c) Based on (a) 5
60% by weight, (b) 15-70% by weight and (c) 10
A developer for a pressure-sensitive recording paper, characterized in that the developer comprises about 40% by weight, and a layer containing the developer is formed on a sheet.

(A): a salicylic acid derivative obtained by reacting 1 mol of styrene with 1 mol of salicylic acid; (b): a salicylic acid derivative obtained by reacting 2 mol of styrene with 1 mol of salicylic acid; A salicylic acid derivative obtained by reacting 3 moles of styrenes.

The salicylic acid derivative (a) in the present invention includes 3- (α-methylbenzyl) salicylic acid,
(Α-methylbenzyl) salicylic acid, 3- (α-, α-dimethylbenzyl) salicylic acid, 5- (α, α-dimethylbenzyl) salicylic acid, 3- (4′-methyl-α-methylbenzyl) salicylic acid, 5- ( 4′-methyl-α-methylbenzyl) salicylic acid, 3- (3′-methyl-α-
Methylbenzyl) salicylic acid, 5- (3′-methyl-α
-Methylbenzyl) salicylic acid, 3- (4'-hydroxy-α-methylbenzyl) salicylic acid, 5- (4'-hydroxy-α-methylbenzyl) salicylic acid, 3-
(4′-chloro-α-methylbenzyl) salicylic acid, 5
-(4'-bromo-α-methylbenzyl) salicylic acid and the like.

The salicylic acid derivatives (b) include 3,5
-Di (α-methylbenzyl) salicylic acid, 3,5-di (α, α-dimethylbenzyl) salicylic acid, 3,5-di (4′-methyl-α-methylbenzyl) salicylic acid,
3,5-di (3′-methyl-α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl) -5- (α, α-
Dimethylbenzyl) salicylic acid, 5- [4 ′-(α′-methylbenzyl) -α-methylbenzyl] salicylic acid, 3-
[4 ′-(α′-methylbenzyl) -α-methylbenzyl] salicylic acid, 3- (1 ′, 3′-diphenylbutyl) salicylic acid, 5- (1 ′, 3′-diphenylbutyl) salicylic acid and the like. .

The salicylic acid derivative (c) includes 3-
(Α-methylbenzyl) -5- [4 ′-(α′-methylbenzyl) -α-methylbenzyl] salicylic acid, 3-
[4 ′-(α′-methylbenzyl) -α-methylbenzyl] -5- (α-methylbenzyl) salicylic acid, 3-
(4′-methyl-α-methylbenzyl) -5- [4′-
(Α′-methylbenzyl) -α-methylbenzyl] salicylic acid, 3- (α, α-dimethylbenzyl) -5
[4 ′-(α′-methylbenzyl) -α-methylbenzyl] salicylic acid, 3- [4 ′-(α′-methylbenzyl) -α-methylbenzyl] -5- (α-methylbenzyl) salicylic acid, 3 -(Α-methylbenzyl) -5-
(1 ′, 3′-diphenylbutyl) salicylic acid, 3-
(1 ′, 3′-diphenylbutyl) -5- (α-methylbenzyl) salicylic acid.

The salicylic acid derivative in the present invention is
(A) 5 to 6 with respect to the sum of (a), (b) and (c)
0% by weight, preferably 10-45% by weight, (b) 15-7%
0% by weight, preferably 30 to 60% by weight, (c) 10 to 4%
0% by weight, preferably 12 to 30% by weight. (A)
However, when the content is less than 5% by weight, the saturation color density becomes low.
If it exceeds 60% by weight, the color development speed decreases and the saturation color density also decreases. When (b) is less than 15% by weight,
Depending on the ratio of (a) and (c), the coloring speed is low or the saturated coloring density is low. If it exceeds 70% by weight, yellowing due to nitric oxide gas is large. (C) is 1
If the amount is less than 0% by weight, yellowing due to nitric oxide gas is large, or the coloring speed is low. If it exceeds 40% by weight, the saturated color density becomes low.

The salicylic acid derivative is usually (a)
It can be obtained by mixing the (b) and (c) alone in a desired ratio or by reacting salicylic acids and styrenes in a desired ratio in the presence of a specific catalyst. . Preferred is a method in which manufacturing complexity is low.

The salicylic acids in the present invention include salicylic acid, alkyl-substituted salicylic acid such as 3-ethylsalicylic acid, 5-ethylsalicylic acid and 3-tert-butylsalicylic acid; salicylic acid having an alicyclic group such as 5-cyclohexylsalicylic acid; Halogen-containing salicylic acids such as salicylic acid and mixtures thereof. Of these, salicylic acid is preferred.

The styrenes include styrene, α-methylstyrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, p-chlorostyrene, 2,4
-Dimethylstyrene, p-vinylphenol, vinylnaphthalene and the like. These may be used in combination of two or more. Of these, styrene is preferred.

In the above method, the salicylic acid derivatives (a), (b) and (c) are prepared by reacting phenols and styrenes by a known method, and separating the respective precursors by distillation under reduced pressure. After that, it can be obtained by a method described in Japanese Patent Publication No. 51-21174 in which CO2 is reacted under pressure. A salicylic acid derivative alone can also be obtained by reacting salicylic acids and styrenes in the presence of an acidic catalyst and separating the reaction product by preparative column chromatography.

In the above method, the catalyst for reacting salicylic acids and styrenes is preferably a polyvalent metal salt of an organic carboxylic acid. Examples of the organic carboxylic acids include aliphatic carboxylic acids such as formic acid, acetic acid, propionic acid, palmitic acid, stearic acid, and oxalic acid; benzoic acid, salicylic acid, 3-benzylsalicylic acid, 5-benzylsalicylic acid,
3- (α-methylbenzyl) salicylic acid, 5- (α-methylbenzyl) salicylic acid, 3- (α, α-dimethylbenzyl) salicylic acid, 5- (α, α-dimethylbenzyl) salicylic acid, 3- (4′- Hydroxy-α-methylbenzyl) salicylic acid, 5- (4′-hydroxy-α-
Methylbenzyl) salicylic acid, 5- (4′-bromo-α
-Methylbenzyl) salicylic acid, 3,5-di (α-methylbenzyl) salicylic acid, 3,5-di (α, α-dimethylbenzyl) salicylic acid, 3- (α-methylbenzyl)
-5- (α, α-dimethylbenzyl) salicylic acid, 3,
5-dibenzylsalicylic acid, 3-benzyl-5- (α,
α-dimethylbenzyl) salicylic acid, 3-benzyl-5
-(Α-methylbenzyl) salicylic acid, 5- [4′-
α′-methylbenzyl) -α-methylbenzyl] salicylic acid, 3- [4 ′-(α′-methylbenzyl) -α-methylbenzyl] salicylic acid, 3- (α-methylbenzyl)
-5- [4 '-(α'-methylbenzyl) -α-methylbenzyl] salicylic acid, 3- [4'-(α'-methylbenzyl) -α-methylbenzyl] -5- (α-methylbenzyl) Salicylic acid, 3- (α, α-dimethylbenzyl) -5- [4 ′-(α′-methylbenzyl) -α-methylbenzyl] salicylic acid, 3- [4 ′-(α′-methylbenzyl) -α- Methylbenzyl] -5- (α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl)
-5- (1 ′, 3′-diphenylbutyl) salicylic acid,
Aromatic carboxylic acids such as 3- (1 ′, 3′-diphenylbutyl) -5- (α-methylbenzyl) salicylic acid, 3,5-di (tert-butyl) salicylic acid, and 3,5-dicyclohexylsalicylic acid. . Among these, the salicylic acid derivative in (A) is preferred.

The metal constituting the polyvalent metal salt of the organic carboxylic acid may be the same as the metal constituting the polyvalent metal salt of salicylic acid, and zinc is preferred. The amount of the organic carboxylic acid polyvalent metal salt to be added is 1 to 100 parts by weight, preferably 5 to 60 parts by weight, per 100 parts by weight of salicylic acids.

If necessary, a conventionally known acidic catalyst may be used in combination with the polyvalent metal salt of the organic carboxylic acid, if necessary. For example, alkylsulfonic acids such as methylsulfonic acid, ethylsulfonic acid, and propylsulfonic acid; acrylamido-2-methylpropanesulfonic acid;
Vinyl (alkenyl) sulfonic acid such as vinylsulfonic acid; aromatic sulfonic acid such as p-toluenesulfonic acid, benzenesulfonic acid, xylenesulfonic acid; mineral acid such as hydrochloric acid, sulfuric acid, phosphoric acid; zinc carbonate, zinc chloride, chloride Examples of such a catalyst include a Friedel-Crafts catalyst such as aluminum, boron trifluoride, and activated clay. The amount of the acidic catalyst used is usually 10% by weight or less based on the polyvalent metal salt of the organic carboxylic acid.

The reaction between salicylic acids and styrenes is carried out in the presence of the above polyvalent metal salt of an organic carboxylic acid, by mixing them, usually at 80 to 180 ° C, preferably 100 to 150 ° C.
Done in The amount of styrene used is usually at least 1.0 mol, preferably 1.5 to 3.0 mol, per 1 mol of salicylic acids. Outside this range, when used as a color developer, the color density is reduced. The reaction time varies depending on the reaction temperature, but is usually 30 minutes to 10 hours, preferably 1 to 5 hours.

The reaction of salicylic acids and styrenes is carried out by mixing salicylic acids and a polyvalent metal salt of an organic carboxylic acid, heating and melting, and then adding styrenes, or a part of styrenes and salicylic acids. After mixing and heating and melting a polyvalent metal salt of an organic carboxylic acid, a method of adding styrenes, salicylic acids and styrenes are mixed once, and the mixture is placed in a reaction vessel in the presence of a polyvalent metal salt of an organic carboxylic acid. There is a method of heating while adding the mixture. Preferred is the method of

In the above reaction, if necessary, an appropriate organic solvent can be used. Examples of the organic solvent include aliphatic hydrocarbon solvents such as pentane, hexane, and cyclohexane; aromatic hydrocarbon solvents such as toluene, benzene, and xylene; chlorinated hydrocarbon solvents such as ethylene dichloride, tetrachloroethylene, and methylene chloride; acetone, methyl ethyl ketone, and the like. Ketones; and esters such as acetates and propionates. The addition amount of the organic solvent is usually 50% by weight or less based on salicylic acids.

The method for producing the salicylic acid derivative will be specifically described below. A mixture of salicylic acids and a polyvalent metal salt of an organic carboxylic acid is heated to 100 to 150 [deg.] C. with stirring to form a liquid that can flow. If necessary, a part of styrenes and / or the above organic solvent is added.
Further, styrenes are added little by little over 30 minutes to 5 hours. After the addition, the salicylic acid derivative is obtained by further maintaining the temperature at 120 to 150 ° C. until the styrene disappears to complete the reaction. Usually 0.5-2
Complete in time.

The polyvalent metal salt of a salicylic acid derivative of the present invention is prepared by mixing the salicylic acid derivative with a polyvalent metal compound in the presence of an organic solvent or water, if necessary, usually at a temperature of 50 to 180 ° C. It is obtained by doing. The polyvalent metal salt of the salicylic acid derivative is obtained by obtaining an alkali metal salt (sodium salt, potassium salt, etc.) or an ammonium salt of the salicylic acid derivative, and then adding a polyvalent metal salt of an inorganic acid to water or methanol or ethanol. The reaction can also be carried out in an aqueous solvent such as

Examples of such polyvalent metal compounds include oxides, carbonates and hydroxides of the above-mentioned polyvalent metals.
Specifically, zinc oxide, zinc chloride, zinc sulfate, zinc carbonate,
Zinc hydroxide, aluminum sulfate, nickel sulfate, tin chloride and zirconium oxychloride. For the purpose of promoting the reaction between the salicylic acid derivative and the polyvalent metal compound, ammonium carbonate, ammonium bicarbonate, ammonium acetate,
Ammonium salts such as ammonium formate and ammonium benzoate and ammonia may be added.

The organic solvent used if necessary includes aliphatic hydrocarbon solvents such as pentane, hexane and cyclohexane, aromatic hydrocarbon solvents such as toluene, benzene and xylene, and chlorinated hydrocarbons such as ethylene dichloride, tetrachloroethylene and methylene chloride. Solvents, ketones such as methyl ethyl ketone and acetone, esters such as acetate and propionate, methyl alcohol
And alcohols such as ethyl alcohol and isopropyl alcohol. One or more of these can be used. Preferred are toluene, methyl ethyl ketone, acetone, ethyl acetate, methyl alcohol, and ethyl alcohol. The amount added is usually 60% by weight or less based on the salicylic acid derivative.

The amount of the polyvalent metal compound used is usually 0.5 to 2 equivalents, preferably 0.8 equivalent, per equivalent of salicylic acids.
~ 1.2 equivalents. The reaction time depends on the melting temperature, the kind and amount of the polyvalent metal compound, the presence or absence and kind of the organic solvent, but is usually 1 to 5 hours.

As the polyvalent metal constituting (A), 2
Trivalent or tetravalent metals such as zinc, calcium, magnesium, barium, lead, aluminum, zirconium, vanadium and tin. Among these, zinc, aluminum and tin are preferred, and zinc is particularly preferred.

The sulfonic acid group-modified polyvinyl alcohol of the present invention can be usually obtained by the following method.

It can be obtained by polymerizing a vinyl monomer having a sulfonic acid group (H), vinyl acetate and, if necessary, other anionic vinyl monomer (J), and saponifying it.

Vinyl monomer having sulfonic acid group (H)
Examples include the following monomers. Aromatic hydrocarbon vinyl sulfonic acid: p- and o-styrene sulfonic acid,
Styrene disulfonic acid, α-methylstyrenesulfonic acid, vinylphenylmethanesulfonic acid, etc .; sulfonic acid group-containing (meth) acrylamide: 2- (meth) acrylamide-2-methylpropanesulfonic acid, 3- (meth)
Acrylamidopropane-1-sulfonic acid, 2- (meth) acrylamidoethyl-1-sulfonic acid, 3- (meth) acrylamido-2-hydroxypropanesulfonic acid, p- (meth) acrylamidomethylbenzenesulfonic acid, etc .; Hydrogen vinyl sulfonic acid: vinyl sulfonic acid, (meth) allyl sulfonic acid and the like.

These vinyl monomers having a sulfonic acid group can be used as a water-soluble salt, if necessary.
These salts include alkali metal salts (salts such as sodium, potassium and lithium), alkaline earth metal salts (salts such as calcium and magnesium), ammonium salts,
And alkylamine salts (salts such as methylamine and trimethylamine) and alkanolamine salts (salts such as triethanolamine and diethanolamine).
Preferred are the sodium and potassium salts.

As (J), a vinyl monomer having a carboxyl group, for example, an unsaturated mono- or polycarboxylic acid [(meth) acrylic acid, crotonic acid, maleic acid,
Itaconic acid, cinnamic acid, etc.] and their anhydrides (maleic anhydride, etc.). The vinyl monomer having a carboxyl group is used as a water-soluble salt if necessary, and examples of these salts include the same salts as those described for the vinyl monomer having a sulfonic acid group.

The polymerization method may be a conventionally known method, for example, a method of polymerizing an aqueous solution or aqueous dispersion of the above-mentioned monomer using a radical polymerization initiator, a method of reverse phase suspension using an organic solvent. Examples thereof include a method by polymerization and a usual method of irradiating radiation, electron beam, ultraviolet light, and the like. Further, after the polymerization, if necessary, an alkali compound may be added to saponify or neutralize or partially neutralize the acid group to obtain an alkali base.

Examples of the alkali compound include alkali metal hydroxides (such as sodium hydroxide, potassium hydroxide and lithium hydroxide), alkali metal carbonates (such as sodium carbonate and sodium bicarbonate), amine compounds, ammonium compounds and the like. Species or more. Of these, preferred are sodium hydroxide and potassium hydroxide.

The content of the sulfonic acid group in (B) is from 0.1 to
It is 30 mol%, preferably 0.5 to 10 mol%. If the sulfonic acid group content is less than 0.1 mol%, the stability of the coating liquid is poor, and if it exceeds 30 mol%, the compatibility with (A) is poor.

The degree of saponification of (B) is usually from 60 to 98 mol%. If the saponification degree is less than 60 mol%, the stability of the aqueous dispersion is poor, and if it exceeds 98 mol%, the compatibility with (A) is poor.

The polymerization degree of (B) is usually from 100 to 2,000.
0. If the degree of polymerization is less than 100, the storage stability of the aqueous dispersion is poor, and if it exceeds 2,000, the viscosity of the aqueous dispersion becomes high and handling is difficult.

In the present invention, the amount of (B) is usually 0.5 to 30% by weight, preferably 1 to 2% by weight based on the weight of (A).
0% by weight. If (B) is less than 0.5% by weight, the stability of the coating liquid is poor, and if it exceeds 30% by weight, the color development speed is reduced.

The developer in the present invention is usually used by dispersing it in water. The method of dispersing in water is not particularly limited. For example, a method of pulverizing and dispersing a developer into fine particles having a particle size of 2 μm or less in water by a pulverizer such as a ball mill, an attritor or a sand grinder, and dissolving the developer in toluene , Methyl ethyl ketone, ethyl acetate, dissolved in an organic solvent such as ethylene dichloride, if necessary, methyl alcohol, ethyl alcohol, acetone,
A water-soluble solvent such as dioxane is added to the solution, and if necessary, the mixture is forcibly stirred with a homomixer, a high-pressure homogenizer or the like in the presence of a dispersant such as a water-soluble polymer.
After the particles are reduced to about 1 to 2 μm, the organic solvent is distilled off.

The method of mixing (A) and (B) of the present invention is not particularly limited. For example, (A) and (B) are dissolved and mixed in an appropriate organic solvent to obtain an aqueous dispersion. A method in which only the organic solvent solution of (A) is made into an aqueous dispersion, a method in which (B) is mixed and the organic solvent is distilled off, and a method in which the organic solvent is removed from the aqueous dispersion of the organic solvent solution in (A). After the distillation, a method of mixing (B) and the like can be mentioned.

The aqueous dispersion of the color developing agent for pressure-sensitive recording paper of the present invention may be blended with an auxiliary agent such as a binder, a pigment, an antifoaming agent and a thickener, if necessary, and then applied to a base material such as paper. Will be constructed. If necessary, a known developer (for example, an inorganic solid acid such as activated clay and bentonite; a phenol-based condensate such as a substituted phenol-formaldehyde resin and a bisphenol A-formaldehyde resin) can be used in combination. .

Examples of the binder include starch and derivatives thereof, cellulose derivatives such as carboxymethylcellulose; carboxyl group-containing (co) polymers such as sodium polyacrylate; and water-soluble polymers such as polyvinyl alcohol. A rubber latex such as a styrene / butadiene copolymer can also be used.

As the pigment, kaolin, clay, talc, calcium carbonate, titanium oxide, silica, zinc oxide,
Examples include inorganic pigments such as aluminum hydroxide and barium sulfate, and organic fine powders such as urea-formalin resin and polystyrene.

The color developing sheet of the present invention can be obtained by applying the above coating liquid on a sheet-like support and drying it.

Examples of the support include paper, synthetic paper, synthetic resin film, etc., and particularly preferred is paper.

The method for forming the coating layer on the sheet of the developer coating solution is not particularly limited, and a conventionally known technique can be used. For example, the above-mentioned coating solution is applied to a support by an air knife coater, a blade coater, a roll coater, or the like, and usually at 20 to 120 ° C.
To form a coating layer. The coating amount on the support is not particularly limited, but is usually 0.5 to 20 g / m ² , preferably ² to 10 g / m ² . The concentration of the salicylic acid derivative polyvalent metal salt in the coating layer is usually 3 to 30% by weight.

[0045]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. Parts and% in Examples are parts by weight and% by weight, respectively. The test methods in the examples are shown below.

(Test Method) (1) Composition of Salicylic Acid Derivative The weight ratio of the composition of the salicylic acid derivative in the present invention was determined by high performance liquid chromatography (column: s) manufactured by Shimadzu Corporation.
Hi-pack PREP-ODS (H) KIT). Detection conditions UV: 240 nm

(2) Average Particle Diameter of Developer-Containing Dispersion The average particle diameter of a dispersion of a polyvalent metal salt of a salicylic acid derivative is measured by a laser diffraction / scattering particle size distribution analyzer LA-70.
It was measured with a type 0 (manufactured by Horiba, Ltd.). Normally, the smaller the particle size, the better the color density when pressure-sensitive paper is used.

(3) Coloring Speed and Saturated Coloring Density Measured in a constant temperature and humidity room at 20 ° C. and 65% RH. Using commercially available blue-colored upper paper using crystal violet lactone as a color-developing dye, the coated surface (lower paper) coated with a coating solution containing a color developer is superimposed on both sides so as to face each other. After passing through the roll calender, the color development density was measured at 15 seconds, 60 seconds and 1 hour afterward with a Macbeth densitometer. Since the color density after 1 hour hardly changes even after 24 hours, the saturation color density was used. The larger the value, the higher the color density.

[Production of polyvalent metal salt of salicylic acid derivative] Production Example 1 Salicylic acid 13 was placed in a 1 L SUS container equipped with a stirrer.
8 parts, 5.5 parts of zinc acetate and 52 parts of styrene were added and heated to 145 ° C. while stirring and mixing. The mixture generates heat,
Melts. Then, 156 parts of styrene were added at a temperature of 145 ° C.
It was dropped over time. A pale yellow-brown homogeneous transparent liquid was obtained. Further, the temperature was maintained at 145 ° C. for 1 hour. Residual styrene in the reaction product was 0.1% or less. When the components contained in the liquid are analyzed by liquid chromatography, 5- (α-methylbenzyl) salicylic acid and 3- (α-methylbenzyl) salicylic acid in component (a) of the present invention; component (b) of the present invention 3,5-di (α-methylbenzyl) salicylic acid corresponding to (3); 3- (α-methylbenzyl) -5 corresponding to component (c) in the present invention
-(1 ', 3'-diphenylbutyl) salicylic acid, 3-
(1 ′, 3′-diphenylbutyl) -5- (α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl)-
A mixture of salicylic acid derivatives containing 5- [4 ′-(α′-methylbenzyl) -α-methylbenzyl] salicylic acid and 3- [4 ′-(α-methylbenzyl) -5-α-methylbenzylsalicylic acid. The weight ratio of (a), (b) and (c) was 38:40:22 Then, 205 parts of toluene and 48 parts of basic zinc carbonate (zinc content 58%) were added to the liquid. Then, the mixture was stirred under reflux for 2 hours to obtain a toluene solution of a zinc salt of a salicylic acid derivative of the present invention having a solid content of 65%.

Production Example 2 Salicylic acid 13 was placed in a 1 L SUS container equipped with a stirrer.
Eight parts, 50 parts of a toluene solution of a zinc salt of a salicylic acid derivative according to the present invention prepared in Example 1 and 52 parts of styrene are added, and the mixture is heated to 145 ° C. while stirring and mixing to melt. Next, 156 parts of styrene were added dropwise at a temperature of 145 ° C. over 2 hours. A pale yellow uniform transparent liquid was obtained. The temperature was further maintained at 145 ° C. for 1 hour. Residual styrene in the reaction product was 0.1% or less. When measured by liquid chromatography, the 5- (a) component corresponding to the component (a) in the present invention is used.
(Α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl) salicylic acid; 3,5-di (α-methylbenzyl) salicylic acid corresponding to the component (b) in the present invention;
3- (α-methylbenzyl) -5- (1 ′, 3′-diphenylbutyl) salicylic acid and 3- (1 ′, 3′-diphenylbutyl) -5 corresponding to the component (c) in the present invention.
-(Α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl)
-5- [4 '-(α'-methylbenzyl) -α-methylbenzyl] salicylic acid, 3- [4'-(α'-methylbenzyl) -α-methylbenzyl] -5- (α-methylbenzyl) It was a salicylic acid derivative mixture containing salicylic acid. The weight ratio of (a), (b) and (c) is 2
7:46:27. Next, 205 parts of toluene and 53 parts of basic zinc carbonate (a zinc content of 58%) are added, and the mixture is stirred under reflux for 2 hours so as to obtain a toluene solution of a zinc salt of a salicylic acid derivative of the present invention having a solid content of 65%. Obtained.

Production Example 3 Salicylic acid 13 was placed in a 1 L SUS container equipped with a stirrer.
8 parts, 3.5 parts of zinc zinc salt of 3.5-di (α-methylbenzyl) salicylate, and 52 parts of styrene were added and heated to 145 ° C. while stirring and mixing. The mixture exotherms and melts. Next, 208 parts of styrene were added dropwise at a temperature of 145 ° C. over 2 hours. A pale yellow-brown homogeneous transparent liquid was obtained. In addition, 14
Maintained at 5 ° C. for 1 hour. The residual styrene in the reaction product is
It was 0.1% or less. When measured by liquid chromatography, 5- (α) corresponding to the component (a) in the present invention
-Methylbenzyl) salicylic acid, 3- (α-methylbenzyl) salicylic acid; 3,5-di (α-methylbenzyl) salicylic acid corresponding to the component (b) in the present invention; 3 corresponding to the component (c) in the present invention -(Α-methylbenzyl) -5- (1 ′, 3′-diphenylbutyl) salicylic acid, 3- (1,3′-diphenylbutyl) -5- (α
-Methylbenzyl) salicylic acid, 3- (α-methylbenzyl) -5- [4 ′-(α′-methylbenzyl) -α-
Methylbenzyl] salicylic acid and a mixture of salicylic acid derivatives containing 3- [4 ′-(α′-methylbenzyl) -α-methylbenzyl] -5- (α-methylbenzyl) salicylic acid as a main component. The weight ratio of (a), (b) and (c) was 11:58:31. Next, 53 parts of toluene and basic zinc carbonate (zinc content 58%) were added,
The mixture was stirred under reflux for 2 hours so that the solid content of the present invention was 6%.
A 5% toluene solution of a zinc composition of a salicylic acid derivative was obtained.

Examples 1 to 3 Using the toluene solutions of the zinc salts of salicylic acid derivatives produced in Production Examples 1 to 3, aqueous dispersions of the respective zinc salts of salicylic acid derivatives were prepared in the following manner. In 100 parts of water, a sulfonic acid group-modified polyvinyl alcohol: Go-Seran L3266
4 parts (manufactured by Nippon Synthetic Chemical Co., Ltd.) were dissolved. While stirring this aqueous solution with a homomixer (manufactured by Tokushu Kika) at 10,000 rpm, the toluene solutions of Production Examples 1 to 3 were
100 parts of each was added to obtain a toluene solution dispersion having an average particle diameter of 0.5 μm. While heating this aqueous dispersion, toluene was distilled off to obtain an aqueous dispersion having a solid content of about 50%.

Comparative Examples 1 to 3 Using the toluene solutions of the zinc salts of salicylic acid derivatives produced in Production Examples 1 to 3, aqueous dispersions of the zinc salts of salicylic acid derivatives were prepared by the following methods. In 100 parts of water, 4 parts of polyvinyl alcohol: Kuraray Poval PVA205 (manufactured by Kuraray Co., Ltd.) was dissolved. The aqueous solution was rotated at 10,000 rpm.
While stirring with a 0 rpm homomixer (manufactured by Tokushu Kika), 100 parts of each of the toluene solutions of Examples 1 to 3 was added to obtain a toluene solution dispersion having an average particle diameter of 0.5 μm. While heating this aqueous dispersion, toluene was distilled off to obtain an aqueous dispersion having a solid content of about 50%.

Comparative Examples 4 to 6 (Comparative Example 4); zinc 3,5-di (α-methylbenzyl) salicylate, (Comparative Example 5); zinc 3- (α-methylbenzyl) salicylate, 5- (α- (Methylbenzyl) zinc salicylate in a weight ratio of 50:50 (Comparative Example 6); 3,5-di (α-methylbenzyl) zinc salicylate, 3-((α-methylbenzyl) -5- (1 ',
3'-diphenylbutyl) zinc salicylate and 3-
Weight ratio of 80:10: zinc (1 ′, 3′-diphenylbutyl) -5- (α-methylbenzyl) salicylate
Comparative Example 1 using a toluene solution composed of 10 mixtures
In the same manner as in Examples 3 to 3, an aqueous dispersion having a solid content of about 50% was obtained.

Examples 4 to 6, Comparative Examples 7 to 12 The aqueous dispersions of the zinc salt of the salicylic acid derivative produced in Examples 1 to 3 and Comparative Examples 1 to 6 were mixed with various auxiliaries with the following compositions, and coated. A working liquid was obtained. Next, the coating solution was sealed in a glass bottle, and allowed to stand at 40 ° C. for one day, and then the amount of aggregates was confirmed with a microscope. The results are shown in Table 1 below.

[0056] The above coating solution on high quality paper of bone dry weight 50 g / m ^2, dried solid content 5 g / m ² and so as to co - were coated with coating rod and dried at 60 ° C. Arawashokushi - DOO Was prepared. A color test was performed on the coated surface. The results are shown in Table 1 below.
Shown in

"Composition of coating liquid" Aqueous dispersion of zinc salt of salicylic acid derivative 4 parts Calcium carbonate 20 parts Sodium hexametaphosphate 0.1 part Kuraray Poval PVA117 (10% aqueous solution) 20 parts Water 55.9 parts

[0058]

[Table 1]

[0059]

The color developer of the present invention is a stable aqueous dispersion with little coagulation during preparation of a coating liquid, and has excellent color development speed and saturated color development density.

Claims (11)

(57) [Claims] 1. A polyvalent metal salt of a salicylic acid derivative (A)
And a sulfonic acid group-modified polyvinyl alcohol (B), wherein the salicylic acid derivative in (A) is the following (a):
Pressure-sensitive recording paper comprising (a) 5 to 60% by weight, (b) 15 to 70% by weight and (c) 10 to 40% by weight based on the sum of (b) and (c). Developer. (A): a salicylic acid derivative obtained by reacting 1 mol of salicylic acid with 1 mol of styrene; (b): a salicylic acid derivative obtained by reacting 2 mol of styrene with 1 mol of salicylic acid; (c): styrenes obtained by 1 mol of salicylic acid Salicylic acid derivative reacted by 3 moles. 2. The developer according to claim 1, wherein the salicylic acid derivative in (A) is obtained by reacting salicylic acids and styrenes in the presence of a polyvalent metal salt of an organic carboxylic acid. 3. The developer according to claim 2, wherein the polyvalent metal salt of an organic carboxylic acid is (A). 4. The developer according to claim 1, wherein (A) is a zinc salt of a salicylic acid derivative. 5. The developer according to claim 2, wherein the organic carboxylic acid is salicylic acid or nucleus-substituted salicylic acid. 6. The sulfonic acid group content in (B) is 0.1%.
The color developer according to any one of claims 1 to 5, wherein the content of the color developer is from 30 to 30 mol%. 7. The developer according to claim 1, wherein the degree of saponification of (B) is from 60 to 98 mol%. 8. The developer according to claim 1, wherein the polymerization degree of (B) is from 100 to 2,000. 9. The developer according to claim 1, wherein the amount of (B) is 0.5 to 30% by weight based on the weight of (A). 10. The developer according to claim 1, wherein (A) and (B) are dispersed in water. 11. A color developing sheet comprising a layer containing the color developing agent according to claim 1 formed on a sheet.