JPH0725193B2 - Color-developing sheet for pressure-sensitive copying paper - Google Patents

Description

TECHNICAL FIELD The present invention relates to a color developer sheet for pressure-sensitive copying paper, and more particularly to a color developer sheet for pressure-sensitive copying with improved slipperiness and printing workability.

[Conventional technology]

Conventionally, a color former, which is a substance that donates electrons or accepts protons such as acids to develop color, and a developer, which is a substance that accepts electrons or donates protons, such as acid clay and activated clay. 、 Attaparjiite 、
Clay materials such as zeolite, bentonite, kaolin,
Pressure-sensitive recording materials utilizing a coloring reaction with an organic acid such as salicylic acid, tannic acid, gallic acid, or a phenol compound, or a metal salt thereof, or an acidic polymer such as a phenol-formaldehyde resin are well known. , U.S. Patents 2,505,470, 2,505,489, 2,550,471, 2,5
48,366, 2,712,507, 2,730,456, 2,730,45
7, 3,418,250, JP-A-49-28,41, JP-A-50-4.
It is described in No. 4,009.

The color-developing layer of pressure-sensitive copying paper is prepared by dissolving the color-developing agent in a solvent and dispersing it in a binder or by incorporating it in a microcapsule, and then a support such as paper, plastic film, resin-coated paper, etc. It is obtained by applying to.
On the other hand, the developer layer is obtained by dissolving or dispersing the developer together with a binder in a medium such as water and applying the solution on a support.

As the layers to be applied, the color-developing layer and the color-developing layer are coated on the same side of one support, or on the opposite sides of different supports.

Then, the color developing agent in the microcapsules is released by the writing pressure or the pressing pressure, and the color is developed in contact with the color developing agent, and the recording according to the pressure is obtained.

As mentioned above, various materials are known as developers used in pressure-sensitive recording materials, but when clay, which is widely used as a developer at present, such as activated clay and acid clay, is used, the coloring It has drawbacks such as poor light resistance or water resistance of the body and poor stability over time.

An organic developer is known as a developer that does not have these drawbacks. As a method for producing a developer sheet using an organic developer, a developer is prepared by using an inorganic pigment, a binder, a dispersant,
A method in which a coating liquid (A) obtained by mechanically dispersing in water together with other additives is applied to a support, or a developer is dissolved in an organic solvent and emulsified in water, an inorganic pigment, a binder,
A method of applying a coating liquid (B) obtained by adding other additives to a support or a method of applying a coating liquid containing (A) and (B) to a support is generally used. .

[Problems to be solved by the invention]

However, the color developer sheet obtained by these methods is
Although it has various excellent performances, it has been found that it has the drawback of poor handleability and printing workability due to poor slipperiness of the coating surface during printing work, etc. It has become necessary.

An object of the present invention is to provide a color developer sheet for pressure-sensitive copying paper, which is excellent in light resistance, water resistance, and stability over time of a color developing material, and has a good coating surface slipperiness and improved printing workability. is there.

[Means for solving problems]

The inventors of the present invention have earnestly studied this problem, and have reached the present invention. That is, in the present invention, in a color developer sheet for pressure-sensitive copying paper using an organic color developer, calcium carbonate is used as a pigment in an amount of 50% or more of all pigments, and an average particle size of 2.0 μm to 5.0 μm.
A developer sheet for pressure-sensitive copying paper, characterized in that it contains 1 to 10% by weight of all pigments of talc of m.

The present invention exhibits excellent light resistance, water resistance, and temporal stability of a color developing body by using an organic developer in a developer sheet for pressure-sensitive copying paper, and also uses calcium carbonate as a pigment. By using it, the above performance is further remarkably improved, and the ink settability is improved.

However, when using calcium carbonate as a pigment,
The slipperiness becomes poor, and it becomes a pressure-sensitive copy sheet with poor handling and printing workability. Although there is a method of using talc as a part of the pigment in order to catch this defect, talc has a weak bonding force between crystals, so that a phenomenon of powder falling occurs, so that only a part of the whole pigment can be used. However, it has been found that the use of talc having an average particle size of 5.0 μm or less reduces powder loss. Furthermore, as a result of experiments, in order to maintain the improvement point of calcium carbonate, calcium carbonate was added in an amount of 50% by weight or more of the total pigment and talc.
It was found that the favorable characteristics of both pigments can be realized at the same time if the content is 10% by weight or less.

The organic developer used in the present invention is preferably an aromatic carboxylic acid, a metal salt thereof, or a phenol resin.

Examples of these aromatic carboxylic acids and metal salts thereof include those described in JP-B-49-10856.

Specific examples of these aromatic carboxylic acids include benzoic acid, chlorobenzoic acid (o, m and p), nitrobenzoic acid (o, m and p), toluic acid (o, m and p), 4- Methyl-3
-Nitrobenzoic acid, 2-chloro-4-nitrobenzoic acid, 2,3
-Dichlorobenzoic acid, 2,4-dichlorobenzoic acid, p-isopropylbenzoic acid, 2,5-dinitrobenzoic acid, p-tert-butylbenzoic acid, N-phenylanthranilic acid, 4-methyl-3
-Nitrobenzoic acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 3,5-dinitrosalicylic acid, 5
-Tert-butylsalicylic acid, 3-phenylsalicylic acid, 3-
Methyl-5-tert-butylsalicylic acid, 3,5-di-tert-
Butyl salicylic acid, 3,5-di-tert-amyl salicylic acid, 3
-Cyclohexylsalicylic acid, 5-cyclohexylsalicylic acid, 3-methyl-5-isoamylsalicylic acid, 5-isoamylsalicylic acid, 3,5-di-sec-butylsalicylic acid, 5-
Nonylsalicylic acid, 2-hydroxy-3-methylbenzoic acid, 2-hydroxy-5-tert-butylbenzoic acid, 2,4-cresotinic acid, 5,5-methylenedisalicylic acid, acetaminobenzoic acid (o, m, p) , 2,4-Dihydroxybenzoic acid, 2,5-
Dihydroxybenzoic acid, anacardic acid, 1-naphthoic acid,
3,5-di-α, α-dimethylbenzyl salicylic acid, 3,5-
Di-α-methylbenzylisalicylic acid, 2-naphthoic acid, 1-
Examples thereof include hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic acid, 2-hydroxy-1-naphthoic acid, thiosalicylic acid, and 2-carboxybenzaldehyde.

Also, as a metal that forms a metal salt with the aromatic carboxylic acid,
Copper, lead, magnesium, calcium, zinc, aluminum, tin, nickel etc. are mentioned.

Further, as the phenolic resins, those known as so-called novolak type phenolic resins shown in JP-B No. 42-20144 are used, and phenol formaldehyde resin, phenol acetaldehyde resin, and phenol acetylene resin are used. For example, p-cresol, p-
P-Alkylphenols such as ethylphenol, p-butylphenol, p-cyclohexylphenol, p-octylphenol, p-nonylphenol, allylphenols such as p-phenylphenol, α-naphthylphenol, β- Polycondensation resins of aralkylphenols such as naphthylphenol, cumylphenol, benzylphenol, halogenated phenols such as p-chlorophenol and formaldehyde or acetaldehyde, and so-called metals modified with zinc or manganese Examples thereof include salt-modified phenol resin.
Two or more kinds of these color developers can be used.

The developer is mechanically dispersed together with an inorganic pigment, a binder, a dispersant and other additives in a water system by a ball mill, an attritor, a sand mill or the like to form a coating liquid (A).

At this time, by adding an inorganic pigment together, desirable effects such as improvement of dispersion efficiency and color developing ability can be obtained.

Further, the developer is dissolved in an organic solvent and emulsified in water, and an inorganic pigment, a binder and other additives are added to form a coating liquid (B).

In this case, if an ionic or nonionic surfactant or a water-soluble polymer is added as another additive, there is an advantage that a stable emulsion can be prepared in a short time.

Further, by using an inorganic pigment in combination in adjusting the coating solution, desired effects such as improvement of coating suitability and hiding power and improvement of color developing ability can be obtained.

Examples of the organic solvent used in the present invention include aliphatic or aromatic esters, biphenyl derivatives, naphthalene derivatives, biphenyl alkanes, and the like. Specifically, methyl amyl acetate (1,3-dimethylbutyl acetate), 2-ethylbutyl acetate, 2
-Ethylhexyl acetate, amyl propitrate, i
so-butyl-iso-butyrate, 2,2,4-trimethyl-1,3
-Pentanediol monoisobutyrate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, 2,4-
Dimethyl-2,4-pentanediol diacetate, 2,2-
Dimethyl-1,3-butanediol diisobutyrate, 2-
Methyl-2,4-pentanediol dipropionate, 2,3,
3,4-Tetramethyl-2,4-pentanediol monoacetate, amyl lactate, 2-methylbiphenyl, 3-methylbiphenyl, 3,3-dimethylbiphenyl, 2,4-dimethylbiphenyl , 2,6-Dimethylbiphenyl, 2,4,6
-Trimethyl biphenyl, cyclohexylbenzene,
Bicyclohexylbenzene, monoisopropylbiphenyl, monoisopropylnaphthalene, diisopropylnaphthalene, 1-isopropiophenyl-2-phenylethane, 1-isopropylphenyl-1-phenylethane, 1,1
-Ditolylethane, 1-ethylphenyl-1-phenylethane, 1-phenyl-1-xylylethane and the like.

A poor solvent such as a petroleum fraction having a boiling point of 150 ° C. to 310 ° C. can be used as a diluent together with these solvents.

Examples of inorganic pigments include oxides, hydroxides, carbonates, silicates of polyvalent metals such as magnesium, aluminum, calcium, titanium, manganese, nickel, zinc, zirconium, molybdenum, tin, antimony and lead (for example, Examples thereof include zinc oxide, calcium oxide, titanium oxide, zinc hydroxide, magnesium hydroxide, magnesium carbonate, calcium carbonate, aluminum silicate), kaolin, talc and activated clay.

In the present invention, calcium carbonate is used as a pigment in an amount of 50% or more of all pigments, and the average particle size is 2.0 μm to 5.0 μm, preferably 2.
It is characterized in that talc of 5 μm to 4.0 μm is contained in an amount of 1 to 10% by weight, preferably 3 to 7% by weight of the total pigment. In this case, other pigments may be used in combination.

At this time, if the average particle size of talc is 2.0 μm or less, the effect of improving the slipperiness is insufficient, and the amount of the necessary binder is increased, resulting in the deterioration of the ink setting property. or
With talc having a particle size of 5.0 μm or more, the coated surface becomes rough and powder drops. The one having a large degree of roughness has a drawback that the printing ink does not adhere well. Regarding the amount of talc used, if the amount of talc is less than 1% by weight of the total pigment, the effect of improving the slipperiness is insufficient.

The coating liquid (A) and the coating liquid (B) are used individually or in a mixture and are added with a binder to be applied to a support. As the binder used for these, those generally known in the art such as styrene are used. -Latexes such as butadiene copolymer latex, polyvinyl alcohol, maleic anhydride-isobutylene copolymer, starch, casein, gum arabic, gelatin, carboxymethyl cellulose,
Synthetic or natural polymer substances such as methyl cellulose can be used.

The final amount of organic developer applied to the support is 0.1 g / m ²
Preferably, 0.2 g / m ^{2 to} 1.0 g / m ² is suitable.

[Action]

The present invention exhibits excellent light resistance, water resistance, and temporal stability of a color developing body by using an organic developer in a developer sheet for pressure-sensitive copying paper, and also uses calcium carbonate as a pigment. By using it, the above performance is further remarkably improved and the ink settability is improved. Further, talc is used as a part of the pigment in order to compensate for the poor slipperiness when calcium carbonate is used as the pigment. Furthermore, in order to reduce the powder falling phenomenon of talc, the average particle size of talc is 2.0 μm
5.0 μm is used, 50% by weight or more of calcium carbonate is used as a pigment, and the average particle size is 2.0 μm
By incorporating 5.0 μm of talc in 1 to 10% of all pigments, the favorable characteristics of both pigments were realized at the same time.

〔Example〕

Hereinafter, the developer sheet for pressure-sensitive copying paper of the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 1 part of 10 parts of zinc 3,5-di-α-methylbenzyl salicylate
-Isopropylphenyl-2-phenylethane (20 parts) was added, and the mixture was heated and dissolved at 90 ° C. This was added to 50 parts of a 2% polyvinyl alcohol (PVA-205 Kuraray) water solution, and a 10% sodium sulfosuccinate aqueous solution was further added as a surfactant.
1 part was added and the emulsion was adjusted with a homogenizer so that the average diameter of the emulsion was 3 μm.

Next, prepare a dispersion of 20% by weight of zinc oxide, 5% by weight of talc having an average particle size of 4 μm sodium hexametaphosphate and 100 parts of water using a Keddy mill, and further add calcium carbonate to 75% by weight of all pigments in water. A mixture of 100 parts of sodium hexametaphosphate and 1 part of hexametaphosphate dispersed with a sand glizer to an average particle size of 4.0 μm, and the above emulsion was mixed, and then 10% PVA-110 (manufactured by Kuraray) as a binder. 100 parts of aqueous solution and carboxy modified SBR latex (SN
-307 Sumitomo Nogatax Co., Ltd.) (10 parts as solid content) was added and water was added to adjust the solid content concentration to 20% to obtain a coating liquid (A).

Next, zinc 3,5-di-α-methylbenzyl salicylate 10
Parts, zinc oxide, 20% by weight of the total pigment, 1 part of sodium hexametaphosphate and 100 parts of water were uniformly dispersed by a sand glider to have an average particle size of 3 μm.

Calcium carbonate and talc having an average particle size of 4 μm were added to the resulting dispersion, and 75% by weight and 5% by weight of all pigments were added to 100 parts of water and 1 part of sodium hexametaphosphate to obtain an average particle size of 4.0 μm.
The product dispersed by using a sand glider was added to obtain m, and 100 parts of a 10% PVA-110 (manufactured by Kuraray) aqueous solution and a carboxy-modified SBR latex (SN-
307, manufactured by Sumitomo Nogatax Co., Ltd.) (10 parts) (as solid content) was added and water was adjusted to a solid content concentration of 20% to obtain a coating liquid (B).

The coating liquid (A) and the coating liquid (B) were mixed at A / B = 50/50 in terms of zinc 3,5-di-α-methylbenzylsalicylate to obtain a coating liquid (C).

The coating liquid (C) thus obtained was applied to an original paper of 50 g / m ² by an air knife coater so that a solid content of 5.0 g / m ² was applied and dried to obtain a color developing sheet.

Example 2 A color developer sheet for pressure-sensitive copying paper was prepared in the same manner as in Example 1 except that talc having an average particle size of 3.5 μm was used instead of talc having an average particle size of 4.0 μm. did.

Example 3 A color developer sheet for pressure-sensitive copying paper was prepared in the same manner as in Example 1 except that talc having an average particle size of 2.5 μm was used instead of talc having an average particle size of 4.0 μm. did.

Example 4 Instead of using calcium carbonate and talc having an average particle size of 4 μm in 75% and 5% of the total pigment in Example 1, 78% by weight of calcium carbonate and 2% by weight of talc having an average particle size of 4 μm were used. A color developer sheet for pressure-sensitive copying paper was prepared in the same manner as in Example 1 except for the above.

Example 5 Example 1 was repeated except that talc having a particle size of 2.0 μm was used instead of talc having an average particle size of 4.0 μm in Example 1.
A color developer sheet for pressure-sensitive copying paper was prepared in the same manner as in.

Comparative Example 1 A developer sheet for pressure-sensitive copying paper was prepared in the same manner as in Example 1 except that talc having an average particle size of 7.5 μm was used instead of talc having an average particle size of 4.0 μm. did.

Comparative Example 2 A developer sheet for pressure-sensitive copying paper was prepared in the same manner as in Example 1 except that talc having an average particle size of 1.0 μm was used instead of talc having an average particle size of 4.0 μm. did.

Comparative Example 3 Pressure-sensitive copying was performed in the same manner as in Example 1 except that calcium carbonate was dispersed to have an average particle size of 2.0 μm instead of using talc having an average particle size of 4.0 μm in Example 1. A developer sheet for paper was prepared.

(Performance comparison) (1) Sliding property Fix with the coated surface A facing upward. Further, the other coated surface B is faced downward and fixed to a 500 g weight having an area of 8 cm × 8 cm. The coated surfaces A and B were overlapped, the weight was pulled up, and the force required to start moving was measured with a U-gauge (manufactured by Shinkoh Co.) to obtain a static mass coefficient. The smaller the value, the more slippery.

It is necessary to be 0.75 or less for practical use.

(2) Ink settability Ink (Toyo Ink, Bright Ultramarine) is applied to the coating surface A with an RI tester so that it will be 2.0 g / m ² , facing the other coating surface B, and onto a 150 g / cm ² mount. 30 seconds after setting, 1 minute after, 2
After a minute, the RI tester again passed through the rolls. The ink settability was examined by observing the stain on the coated surface B with the ink.

The judgment criteria are as shown below, but from a practical point of view, it is desirable that it is C or higher.

A. Almost no dirt is observed.

B. Staining is visible 30 seconds after ink application.

C. Contamination is recognized even 1 minute after ink application.

D. Significant stain is observed even 2 minutes after ink application.

(3) Roughness of coated surface Rubbing of the coated surface with a fingertip is indicated by x, and smooth one is indicated by o.

As shown in Table 1, it can be seen that all of the examples of the present invention have good ink-set and slip properties. In addition, there is no roughness on the coated surface, and the paste of printing ink is good.

〔The invention's effect〕

The present invention, by using an organic developer, exhibits excellent performance in light resistance, water resistance, and stability over time of a color-developing material. The ink set contains 50% by weight or more of calcium carbonate as a pigment. To improve roughness and roughness of coated surface, and also to have poor sliding property which is a defect due to calcium carbonate. 2 to 5 μm talc is 1 to 10% by weight of all pigments.
This has been solved by embedding it, and we have realized a color developer sheet for pressure-sensitive copying paper that has excellent light resistance, water resistance, and temporal stability of the color developing material, and has good coating workability and excellent printing workability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kei Satoshi Kei Satoshi 200 Onanakazato, Fujinomiya-shi, Shizuoka Fuji Photo Film Co., Ltd. (56) Reference JP-A-58-155992 (JP, A)

Claims (1)

[Claims] 1. A developer sheet for pressure-sensitive copying paper using an organic developer, wherein calcium carbonate is used as a pigment.
A color-developing sheet for pressure-sensitive copying paper, which contains 50% by weight or more of talc having an average particle size of 2.0 μm to 5.0 μm and contains 1 to 10% by weight of all pigments.