JPH061062A - Manufacture of developer-coated sheet - Google Patents

Abstract

PURPOSE:To provide a developer-coated sheet, in which color developing properties and stain resistance are balanced excellently. CONSTITUTION:In the manufacture of a developer coated sheet, in which a support is coated with the aqueous dispersion of a developer composition and dried, the aqueous dispersion, which has the developer composition mainly comprising the polyvalent metallic salt of nucleus-substituted salicylic acid, sphericity of which shown in sphericity (%)=n/NX100 (n: the number of spherical particles per unit area and N: the number of all particles per the unit area) is 90% or more, and a liquid temperature of which is kept at 0-40 deg.C and B-type viscometer viscosity (60rpm) of which is kept to be 150cps or below is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color developer-coated sheet used for a pressure-sensitive recording material, and more specifically, to provide a color developer-coated sheet having an excellent balance of color developability and stain resistance. .

[0002]

2. Description of the Related Art Novolak-type phenolic resins and polyvalent metal salts of nuclei-substituted salicylic acid are called organic developers, whereas activated clay is called inorganic developers. Widely put to practical use as an agent sheet (Japanese Patent Publication No.
20144, Japanese Examined Patent Publication No. 51-25174). And
All of these organic color developers are usually finely pulverized or finely dispersed in water as a medium to form an aqueous dispersion, and an inorganic pigment, an adhesive and the like are mixed and then coated on a paper surface (Japanese Patent Publication No. 48-1).
6341, JP-A-54-143322).

When a novolac type phenol resin is used as an organic developer in a developer sheet, the coloring property is weaker than that of a polyvalent metal salt of a nucleus-substituted salicylic acid. There is a problem that it will turn yellow due to NOx, SOx, sunlight, heat, etc.
A polyvalent metal salt of nuclear-substituted salicylic acid is preferably used.

As a method for obtaining an aqueous dispersion of a developer composition containing a polyvalent metal salt of nucleus-substituted salicylic acid as a main component, a developer composition containing a polyvalent metal salt of nucleus-substituted salicylic acid as a main component is used. A method of finely pulverizing to a desired particle size with a ball mill, a sand mill, or the like, adding an organic solvent to a developer composition containing a polyvalent metal salt of a nucleus-substituted salicylic acid as a main component to liquefy, and powerfully in water containing a dispersant. By emulsifying and dispersing with a dispersing means, and then heating the dispersion to remove the organic solvent by distillation, a developer composition containing a polyvalent metal salt of a nucleus-substituted salicylic acid of a desired particle size as a main component. (JP-A-63-173680 and JP-A-64-34782)
Etc. are disclosed. As the sphericity of the developer composition,
The former method has 0%, and the latter method has almost 100%.
%.

By the way, it has been desired that the pressure-sensitive recording material has excellent coloring property. However, in general, a color developer sheet having excellent color developability is liable to cause color stains due to involuntary pressure such as rubbing. In order to solve this problem, improvements in microcapsules containing a color-forming agent have been studied, but a sufficient pressure-sensitive recording material has not been obtained yet.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color-developing agent-coated sheet in a pressure-sensitive recording material which is excellent in both color development and stain resistance in good balance.

[0007]

In view of the above situation, the inventors of the present invention have conducted diligent research on a developer-coated sheet, and as a result, previously found that a polyvalent metal salt of a nucleus-substituted salicylic acid was used as a main component of the developer composition. And the sphericity of the developer composition is at least 90
It has been found that a developer coated sheet having a good balance of color developability and stain resistance can be obtained by using an aqueous dispersion of up to 10% (JP-A-3-202388). However, it was found that the desired effect could not be obtained in some cases even using such an aqueous dispersion.

[0008] Therefore, as a result of further intensive studies, coloring was achieved by using an aqueous dispersion having a sphericity of at least 90% within a specific temperature range and at a specific viscosity or less. It has been found that a developer coated sheet having a good balance of stain resistance and stain resistance can be obtained.

The present invention is a method for producing a developer-coated sheet in which an aqueous dispersion of a developer composition is applied to a support and dried, and the sphericity represented by the following formula is 90% or more. A water dispersion having a developer composition containing a polyvalent metal salt of a nucleus-substituted salicylic acid as a main component, a liquid temperature kept at 0 to 40 ° C., and a B-type viscometer viscosity (60 rpm) kept at 150 cps or less. A method for producing a developer-coated sheet, which comprises using a liquid. True sphericity (%) = n / N × 100 n: Number of true spherical particles per unit area N: Number of all particles per unit area

[0010]

The sphericity referred to in the present invention is the number of true spherical particles per unit area observed by observing an aqueous dispersion of a developer composition containing a polyvalent metal salt of nucleus-substituted salicylic acid as a main component with a microscope. The number n and the number N of all particles are counted and calculated by the above formula.

When a developer composition containing a polyvalent metal salt of a nucleus-substituted salicylic acid having a sphericity of less than 90% as a main component is used, the sphericity is lowered and the color developability, especially the weak pressure color developability and the printing are achieved. The connection of is reduced. In order to maintain good color development, the amount of developer composition used must be increased, which is economically negative. The present invention uses a developer composition having a sphericity of 90% or more as a main component. Above all, it is preferable to use a developer composition having a sphericity of 93% or more, particularly 96% or more, as a main component because the color forming property, particularly the weak pressure color forming property and the connection of printing are excellent.

Even in an aqueous dispersion containing such a developer composition, it is necessary to keep the liquid temperature in the range of 0 ° C to 40 ° C. By the way, if the liquid temperature is lower than 0 ° C., the aqueous dispersion will be frozen. The dispersion system of the once-frozen water dispersion is broken, and even if it is thawed and finished as a developer-coated sheet, the color developability is greatly reduced. On the other hand, it is not preferable to use an aqueous dispersion which is kept at a liquid temperature of higher than 40 ° C., because stains are likely to occur. This tendency becomes more remarkable as the holding time exceeds 40 ° C.

Further, even an aqueous dispersion containing a developer composition in which the liquid temperature is maintained in the range of 0 ° C. to 40 ° C. is maintained in a state in which the viscosity of B type viscometer (60 rpm) exceeds 150 cps. When the above-mentioned aqueous dispersion is used, the color-developing agent-coated sheet obtained has both poor color development and stain resistance. This tendency also has a B-type viscometer viscosity (60 rpm) of 150.
This tendency becomes more remarkable as the holding time exceeds cps. The present invention provides a B-type viscometer viscosity (6
0 rpm) is 150 cps or less, preferably 100 cp
It holds the aqueous dispersion containing the developer composition below s.

In the present invention, an aqueous dispersion of a developer composition containing a polyvalent metal salt of a nucleus-substituted salicylic acid having a sphericity of 90% or more as a main component has a liquidity of 0 ° C to 40 ° C. In addition, the viscosity of the B-type viscometer (60 rpm) needs to be maintained at 150 cps or less. In order to maintain such conditions, it is necessary to appropriately adjust temperature conditions, stirring conditions, the amount of dispersant used, and the like. For example, when an aqueous dispersion of a developer composition containing a polyvalent metal salt of a nucleus-substituted salicylic acid having a sphericity of 90% or more as a main component is stored at about 35 ° C. under continuous stirring, the aqueous dispersion B type B is obtained. The viscosity of the viscometer (60 rpm) gradually increases and eventually exceeds 150 cps, so that only a developer coated sheet having poor color development and stain resistance can be obtained.

The stirring may be continuous stirring or discontinuous stirring, and generally known stirring blades such as paddle type, turbine type and propeller type can be used, and the number and size of the stirring blades can be appropriately selected and used. it can. Regarding the stirring speed, the stirring blade to be used, a device such as a tank, and the like, which is performed according to the concentration of the aqueous dispersion, etc., cannot be generally stated, but excessive stirring tends to increase the viscosity, and in view of energy efficiency. The stirring may be adjusted to such an extent that sedimentation does not occur in the aqueous dispersion.

The dispersant is preferably a dispersant having a large protective colloid property because it can maintain the stable dispersion state of the aqueous dispersion for a long time. However, in a dispersion system having a large protective colloidal property, generally, the foaming property is large, and mechanical fine pulverization treatment,
When the organic solvent is removed from the emulsion of the developer containing the organic solvent in the dispersion state as it is, a lot of bubbles are generated and the operation is often impossible. However, an anionic or nonionic water-soluble polymer having an average molecular weight of 300 or more has a large protective colloid property and is suitable because it causes less bubbles.

Anionic or nonionic water-soluble polymer having an average molecular weight of 300 or more is disclosed in JP-A-62-19849.
No. 2, JP-A-63-109084, JP-B-63-17
635, JP-A-2-204083, JP-A-3-22.
No. 7687 and the like, at least acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, itaconic acid, itaconic acid ester, maleic acid, maleic acid ester, acrylamide, isobutylene, α-methylstyrene, sulfone. A copolymer composed of one kind of a monomer such as styrene or naphthalene sulfonic acid may be mentioned. Among them, a copolymer composed of methacrylic acid, an alkyl acrylate or an alkyl methacrylate, a copolymer composed of methacrylic acid, an alkyl methacrylate or acrylamide, and a copolymer composed of acrylamide or acrylic acid are preferable.

Examples of the metal salt of the nucleus-substituted salicylic acid include JP-B-49-10856, JP-B-51-25174, JP-A-49-55410, JP-A-3-227687,
As described in JP-A-3-215084,
3,5-di (α-methylbenzyl) salicylic acid, 3-α
-Benzylated phenylethylsalicylic acid, 3-α-methyl-α-ethylpentyl-5-α, α-dimethylbenzylsalicylic acid, 3-cumyl-5-isooctylsalicylic acid, 3-cumyl-5-tert-butylsalicylic acid , 3-te
rt-Butyl-5-cumylsalicylic acid, 3,5-di-tert
-Butylsalicylic acid, 3,5-di-tert-octylsalicylic acid, 3,5-di-isononylsalicylic acid, 3,5-
Di-isododecylsalicylic acid, 3,5-di (methylcumyl) salicylic acid, 3,5-dicumylsalicylic acid, 3-α
-Methylbenzylated phenylethyl-6-methylsalicylic acid, 3-α-methyl-α-ethylpentyl-6-methylsalicylic acid, 3,5-di (α-benzylated phenylethyl) salicylic acid, 3,5-di (benzyl Benzyl chloride)
Salicylic acid, 3,5-di (α-methylbenzyl) -6-
Methylsalicylic acid, 3-α-tolylethyl-6-methylsalicylic acid, 3,5-di (α, α-dimethylbenzyl)
-6-Methylsalicylic acid, 3,5-di-tert-octyl-6-methylsalicylic acid, 3-α-dimethylphenylethyl-6-methylsalicylic acid, 3-α-ethylphenylethyl-6-methylsalicylic acid, 3-α -Nucleo-substituted polyvalent metal salts of isopropylphenylethyl-6-methylsalicylic acid, 3-α-benzylated benzylphenylethyl-6-methylsalicylic acid, 3-α-methyl-α-ethylpentyl-6-ethylsalicylic acid, etc. Is mentioned. Here, the isononyl group, the isododecyl group, and the isopentadecyl group are collectively defined as the substituents produced by addition of propylene trimer, propylene tetramer or 1-butene trimer and propylene pentamer, respectively. Among these, 3,5-di-substituted salicylic acid is particularly preferable because it has extremely good color developability.

Specific examples of the polyvalent metal include magnesium, calcium, zinc, aluminum, iron, cobalt,
Nickel and the like can be mentioned, but zinc is most preferable. Further, the above-mentioned various kinds of nucleus-substituted salicylic acids may be used not only alone but also as a mixture.

If the softening point is too low among these color developer compositions, the color developer composition is likely to permeate and migrate between the paper fibers during coating and drying on the paper surface, resulting in a color density. May decrease, or the aqueous dispersion of the developer composition may easily coagulate, resulting in lack of storage stability for a long time. Therefore, the softening point of the developer composition containing the polyvalent metal salt of the nucleus-substituted salicylic acid as the main component is preferably 40 ° C. or higher. However, if the softening point is extremely high, it hardly exhibits self-adhesion when it is applied and dried on the paper surface, so a large amount of adhesive must be used to fix it on the paper surface. In some cases, the adhesive forms a film on the developer composition, hinders the transfer of the color-dissolving agent-dissolved oil present in the microcapsules during recording, and the color-developing ability is slightly inferior. Therefore, the softening point of the developer composition containing the polyvalent metal salt of the nucleus-substituted salicylic acid as the main component is more preferably adjusted to about 40 to 85 ° C.

As a method for adjusting the color developer composition to a preferable softening point temperature, a method of mixing a polyvalent metal salt of a nucleus-substituted salicylic acid having a different softening point, or a softening point for lowering the softening point of the color developer Substances that reduce the amount of, for example, metal salts of fatty acids,
A method of adding trialkylphenol, triaralkylphenol, styrene oligomer, or the like, a substance such as polystyrene, poly-α-methylstyrene, or petroleum which increases the softening point to a polyvalent metal salt of a nucleus-substituted salicylic acid having a softening point that is too low. Examples include a method of adding a resin and the like. The mixing ratio is not particularly limited. The softening point referred to in the present invention means a softening temperature in a state in which the developer composition containing a polyvalent metal salt of a nucleus-substituted salicylic acid as a main component contains equilibrium water in water, and usually in a dry state. The value is about 50 ° C lower than the softening point.

To obtain a developer composition containing a polyvalent metal salt of a nucleus-substituted salicylic acid having a sphericity of 90% or more as a main component, a developer containing a polyvalent metal salt of a nucleus-substituted salicylic acid as a main component is used. A method is preferably used in which an organic solvent is added to the composition for liquefaction, emulsified and dispersed in water containing a dispersant by a strong dispersing means, and then the dispersion is heated to remove the organic solvent by distillation. In this method, the developer composition containing a polyvalent metal salt of nucleus-substituted salicylic acid as a main component is emulsified and dispersed in an aqueous medium, so that it is necessary to include a dispersant in the aqueous medium. Examples of the dispersant include anionic surfactants such as alkali salts of alkyl sulfates, alkali salts of alkylbenzene sulfonic acids, alkali salts of alkylnaphthalene sulfonic acids, alkali salts of oleic acid amide sulfonic acids, and alkali salts of dialkyl sulfosuccinic acids. , Nonionic surfactants such as polyoxyethylene alkyl ether and polyoxyethylene fatty acid ester, natural polymeric substances such as gum arabic, sodium alginate, agar and gelatin, carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethylated starch, phosphorylated starch , Semi-synthetic polymer such as sodium lignin sulfonate, methyl vinyl ether / maleic anhydride copolymer, ethylene / maleic anhydride copolymer, styrene / maleic anhydride copolymer, acetic acid Alkali salts of polymers and copolymers such as acid polymers, acrylic acid / methyl methacrylate copolymers, acrylic acid / acrylamide copolymers, vinylbenzene sulfonic acid polymers, polyvinyl alcohol, polyacrylamide, vinylcarboxylic acid Examples thereof include synthetic polymer substances such as ester / acrylamide copolymers. Of these, vinyl carboxylic acid ester / acrylamide copolymers are preferable. Acrylamide having a degree of polymerization of 100 or more and a copolymerization ratio of at least 70 to 96 mol% of acrylamide and 4 to 30 mol% of an alkyl or alkoxyalkyl ester of acrylic acid, methacrylic acid, itaconic acid or maleic acid having 4 or less carbon atoms. The copolymer is particularly preferable because it has a large protective colloid property and a small foaming property.

The amount of these dispersants used is appropriately adjusted according to the size of the target dispersed particles, etc., but is preferably in the proportion of about 1 to 30 parts by weight per 100 parts by weight of the color developer composition. Adjusted. These dispersants may be used alone or in combination of two or more. The emulsification and dispersion may be performed with or without heating.

The developer composition containing the polyvalent metal salt of the nucleus-substituted salicylic acid as the main component thus obtained has a sphericity of 9
When the dispersion treatment is further performed to the extent of not lower than 0%, various sand mill type pulverizers using pulverization media such as ball mills, pebble mills, sand mills (vertical and horizontal types), cobol mills, attritors, dyno mills, three roll mills, High speed grinders such as high speed impeller dispersers, high speed stone mills and high speed impact mills can be used, but sand mill type crushers (vertical type, horizontal type) considering the ease of setting processing conditions and crushing efficiency. It is preferable to use a high-speed impeller disperser, and it is more preferable to use a sand mill type pulverizer (vertical type or horizontal type).

For the coating liquid for forming the developer layer, the aqueous dispersion of the developer composition thus obtained is usually further used as an adhesive, for example, starch, casein, gum arabic, carboxymethyl cellulose, Polyvinyl alcohol, styrene / butadiene copolymer latex, vinyl acetate latex and the like are blended. Further, inorganic pigments such as zinc oxide, magnesium oxide, titanium oxide, aluminum hydroxide, calcium carbonate, magnesium sulfate and calcium sulfate, and various auxiliaries known in the field of the developer coated sheet can be appropriately added.

The thus-prepared coating liquid for the developer layer is used for fine paper, coated paper, synthetic paper by a conventional coating device such as an air knife coater, a blade coater, a roll coater, a size press coater, a curtain coater and a short dwell coater. It is applied onto a support such as paper or film and finished as a developer coated sheet. The coating amount of the developer layer coating liquid on the support is not particularly limited, but is about ² to 8 g / m ^{2 in} dry weight.

The method for producing the color developer coated sheet of the present invention is as follows:
A self-coloring type pressure-sensitive copying paper (so-called self-printing) having a color developer layer and a color developer layer on the same surface of a support or having a mixed coating layer of a color developer coating liquid and a coating liquid containing an encapsulated color developing agent. It can also be applied to the content type). Of course, the color-developing agent-coated sheet thus obtained can be subjected to known processing of the pressure-sensitive recording material, such as providing a color-developing agent layer on the back surface, providing an adhesive layer, and providing a carbon ink layer. Further, it can also be used for a developer sheet of a light and pressure sensitive recording material in which a photocurable microcapsule and a basic dye are combined.

[0028]

EXAMPLES Examples and comparative examples will be described below in order to further clarify the effects of the present invention, but the present invention is not limited to these. Further, "parts" and "%" in the examples represent "parts by weight" and "% by weight", respectively, unless otherwise specified.

Example 1 2000 g of water and 400 g of zinc sulfate (heptahydrate) were placed in a cylindrical stainless steel container having an inner volume of 20000 ml and equipped with a stirrer and a thermometer and dissolved. To this, 8500 g of a 10% aqueous solution of sodium 3,5-di (α-methylbenzyl) salicylate is added with vigorous stirring. Due to the metathesis, the inside of the container immediately becomes a thixotropic drop. Here, 880 g of methyl isobutyl ketone (boiling point: 116 ° C.) containing 150 g of a copolymer of α-methylstyrene and styrene (copolymerization ratio: 40 to 60 mol%, average molecular weight: about 1500) is added within a short time. Since the fluidity of the thixotropic-dropped contents gradually improves, when the contents become easy to flow, the container is heated to bring the temperature of the contents to 75 ° C and allowed to stand. Since the aqueous phase is separated into the upper layer and the oil phase is separated into the lower layer, the whole oil layer is taken out and transferred to a beaker made of hard glass having an internal volume of 5000 ml. This was further added with 600 g of water and sodium carbonate 2.
5 g, polyvinyl alcohol (saponification degree: 98%, degree of polymerization about 1700) 5% aqueous solution 500 g, and copolymer of ethyl acrylate and acrylamide (copolymerization ratio: 13 to 87 mol%, degree of polymerization: about 400) 25% Add 60 g of the aqueous solution, and add 35
A homomixer (Model M, manufactured by Tokushu Kika Kogyo Co., Ltd.) at a temperature of 40 to 40 ° C. is subjected to an emulsification operation for 20 minutes at a rotation speed of 8800 to 9000 rpm to obtain an oil-in-water emulsion. This was transferred to a hard glass three-necked flask with an internal volume of 10,000 ml equipped with a stirrer, a thermometer and a distillation port, 2000 g of water was further added, and the contents were slowly stirred while heating the flask to boil. When methyl isobutyl ketone and a part of water are taken out from the distillation port, the content becomes a dispersion liquid containing no methyl isobutyl ketone and having a total solid content of 38%. The resulting developer composition dispersed particles had a sphericity of 100% and an average particle diameter of 1.2 μm.

Then, the above 38% (solid content) of 3,5-di (α-methylbenzyl) salicylate zinc was placed in a stainless steel vat with a lid having an internal volume of 5 liters (the stir bar was inserted in the center). Add 3 kg of dispersion. Next, attach a stirrer with a blade of 5 cm in length and 1 cm in width to a stainless steel vat, and in a water tank controlled at a temperature of 15 to 20 ° C. with continuous stirring at a speed of 100 rpm. After being immersed for 15 days, the viscosity (60 rpm) of the dispersion liquid for 15 days was measured with a B-type viscometer. Viscosity (6
0 rpm) remained at 100 cps or less.

[Preparation of color developer coating liquid] 27 parts of 38% color developer composition dispersion stored for 15 days as described above,
90 parts of calcium carbonate and 100 parts of water are mixed and dispersed, and further 50 parts of 10% polyvinyl alcohol aqueous solution and 10 parts of 50% carboxy-modified SBR latex (SN-307, manufactured by Sumitomo Nogatak Co.) are mixed and dispersed as a binder. A developer coating solution was prepared.

[Manufacture of Developer Coated Sheet for Pressure Sensitive Copy Paper]
The developer coating solution was applied onto one side of a base paper of 40 g / m ^{2 so} that the dry weight was 4 g / m ^2, and dried to obtain a developer coated sheet for pressure-sensitive copying paper.

Examples 2 to 3 In Example 1, the above 38% (solid content) dispersion of zinc 3,5-di (α-methylbenzyl) salicylate was treated with a sand mill (Igarashi Kikai Co., Ltd.) to prepare a true Sphere rate is 98
% (Example 2), 94% (Example 3), except that the developer-coated sheet for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Example 4 2000 g of water and 400 g of zinc sulfate (heptahydrate) were placed in a cylindrical stainless steel container having an inner volume of 20000 ml and equipped with a stirrer and a thermometer and dissolved. To this, 8500 g of a 10% aqueous solution of sodium 3,5-diisononylsalicylate is added while vigorously stirring the contents. Due to the metathesis, the inside of the container immediately becomes a thixotropic drop. Here, xylene (boiling point: 139) containing 150 g of a copolymer of α-methylstyrene and styrene (copolymerization ratio: 40 to 60 mol%, average molecular weight: about 1500).
C.) 880 g in a short time. Since the fluidity of the thixotropic-dropped contents gradually improves, when the contents become easy to flow, the container is heated to bring the temperature of the contents to 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 a 0 ml hard glass beaker. This was further added with 600 g of water, 2.5 g of sodium carbonate, polyvinyl alcohol (saponification degree: 98%, polymerization degree of about 1700), 5% aqueous solution 50
0 g and 60 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) were added, and a homomixer (model M, special Made by Kika Kogyo Co., Ltd.) 88 per minute
An oil-in-water type emulsion is obtained by performing an emulsification operation for 20 minutes at a rotation speed of 00 to 9000 times. This is an internal volume 100 with a stirrer, thermometer and distillation port.
Transfer to a 00 ml hard glass three-necked flask and add water 2
After adding 000 g, heat the flask to a boil while slowly stirring the contents. When xylene and a part of water are taken out from the distillation port, the content becomes a xylene-free dispersion liquid having a total solid content of 38%. The resulting developer composition dispersed particles have a sphericity of 100% and an average particle size of 1.0 μm.
It was m.

Then, 3 kg of the 38% (solid content) zinc 3,5-diisononylsalicylate dispersion liquid is placed in a stainless steel vat having an internal volume of 5 liters and having a lid (the stirring port is inserted in the central portion). Next, attach a stirrer with a blade of 5 cm in length and 1 cm in width to a stainless steel vat, stir at a speed of 100 rpm for 10 minutes, and stop for 50 minutes, repeating from 30 to 35 ° C. It was immersed in a temperature-controlled water bath for 15 days, and the viscosity (60 rpm) of the dispersion liquid for 15 days was measured with a B-type viscometer. During that time, the viscosity (60 rpm) remained below 100 cps. Thereafter, a color developer-coated sheet for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Example 5 3,5-di (α-methylbenzyl) obtained in Example 1
3 kg of the zinc salicylate dispersion is placed in a stainless steel vat with an internal volume of 5 liters, which has a lid (there is a stirring bar insertion hole in the center). Next, attach a stirrer having a blade of 5 cm in length and 1 cm in width to a stainless steel vat, and stir it with a copolymer of ethyl acrylate and acrylamide (copolymerization ratio; 13:87 mol%, polymerization). Degree; about 4
50 g of 25% aqueous dispersion of 00) is added. And 1 per minute
While continuously stirring at a speed of 00 rotations, the mixture was immersed in a water tank controlled at a temperature of 30 ° C. to 35 ° C. for 15 days, and the dispersion liquid for 15 days had a viscosity (60 rp
m) was measured. The viscosity (60 rpm) in the meantime is 100
It remained below cps. Thereafter, a color developer-coated sheet for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Example 6 3 kg of the dispersion of zinc 3,5-diisononylsalicylate obtained in Example 4 was placed in a stainless steel vat with a lid having an internal volume of 5 liters (the stirring port was inserted in the center). Put in. Next, attach a stirrer having a blade of 5 cm in length and 1 cm in width to a stainless steel vat, and stir it with a copolymer of ethyl acrylate and acrylamide (copolymerization ratio; 15:85 mol%, polymerization). Degree; about 700) 25%
Add 50 g of water dispersion. Then, the mixture was stirred for 10 minutes at a speed of 100 rpm and stopped for 50 minutes, immersed in a water tank controlled at a temperature of 30 ° C to 35 ° C for 15 days, and a dispersion liquid B-type viscometer for 15 days. Viscosity (60 rpm) was measured. Viscosity in the meantime (60 rp
m) remained below 100 cps. Thereafter, a color developer-coated sheet for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Comparative Example 1 38% (solid content) 3,5-obtained in Example 1
Disperse the zinc di (α-methylbenzyl) salicylate dispersion 4
It was immersed in a water bath controlled at a temperature of 5 ° C. to 50 ° C. and continuously stirred at a speed of 100 rpm. The viscosity (60 rpm) of the B-type viscometer increased, and stirring was continued until it exceeded 1000 cps, and then stopped. Thereafter, an aqueous dispersion of the color developer was used to obtain a color developer-coated sheet for pressure-sensitive copying paper in the same manner as in Example 1.

Comparative Example 2 38% (solid content) of 3,5-obtained in Example 1
The dispersion of zinc di (α-methylbenzyl) salicylate was treated with a sand mill (Igarashi Kikai Co., Ltd.) to obtain a sphericity of 8
A developer-coated sheet for pressure-sensitive copying paper was obtained in the same manner as in Example 1 except that the content was changed to 5%.

Comparative Example 3 Water was prepared in the same manner as in Example 6 except that the water tank controlled at a temperature of 30 ° C. to 35 ° C. was replaced with a water tank controlled at a temperature of 45 ° C. to 50 ° C. The dispersion was kept for 3 days. The viscosity (60 rpm) of the B-type viscometer of the aqueous dispersion for 3 days remained below 100 cps. Thereafter, in the same manner as in Example 6, a color developer-coated sheet for pressure-sensitive copying paper was obtained.

Comparative Example 4 In Example 5, the stirring speed of the stirrer was set to 200 per minute.
Immersing in a water bath controlled at a temperature of 30 ° C to 35 ° C with continuous stirring at a speed of 0 revolutions
The stirring was stopped when the viscosity (60 rpm) of the mold viscometer exceeded 1000 cps. Thereafter, an aqueous dispersion of the color developer was used to obtain a color developer-coated sheet for pressure-sensitive copying paper in the same manner as in Example 5.

The following quality evaluation tests were carried out on the above 10 types of pressure-sensitive copying paper color developer coated sheets, and the results are shown in Table 1.
It was shown to. [Preparation of upper paper] Crystal violet lactone was dissolved in alkylated naphthalene, and a capsule coating liquid prepared by microencapsulating this oily liquid was applied to one side of high-quality paper so that the dry weight was 4 g / m ^2, and dried. I got the top paper.

[Low pressure color development test] 25
A drop-type color tester (weight: 25
(g, height: 15 cm), and after allowing to stand for 2 days, the color density was measured with a Macbeth reflection densitometer. [Staining resistance test] The developer-coated sheet and the upper paper are superposed so that the coated surfaces face each other, and rubbed five times with a load of 5 kg / cm ² applied to apply the developer-coated sheet. The degree of color stain on the surface was determined, and the results are shown in Table 1.

Evaluation ◯: Stain is not noticeable and poses no practical problem. X: Stain is noticeable and poses a practical problem.

[0045]

[Table 1]

[0046]

As is apparent from the results shown in Table 1, according to the present invention, a color developer coated sheet having excellent color developability and improved rubbing stains can be obtained.

Claims (2)

[Claims] 1. A support is coated with an aqueous dispersion of a developer composition.
In the method for producing a developer-coated sheet to be dried, a developer composition containing a polyvalent metal salt of a nucleus-substituted salicylic acid having a sphericity represented by the following formula of 90% or more as a main component, Moreover, the liquid temperature is maintained at 0 to 40 ° C., and the viscosity of the B-type viscometer (60 rp
A method for producing a developer-coated sheet, comprising using an aqueous dispersion liquid in which m) is maintained at 150 cps or less. True sphericity (%) = n / N × 100 n: Number of true spherical particles per unit area N: Number of all particles per unit area 2. A polyvalent metal salt of a nucleus-substituted salicylic acid is 3,5
The method for producing a developer-coated sheet according to claim 1, which is a di-substituted zinc salicylate.