JPH0250880A - Color developing paper for pressure-sensitive copying paper - Google Patents

Abstract

PURPOSE:To obtain color developing paper for pressure-sensitive copying forming a color image superior in light resistance, water resistance, and stability with time and having a smooth sliding property on a coated surface and a superior printability by containing a specific kaolin and a calcium carbonate as a pigment in a color developing layer respectively in a specific ratio to the total weight of an organic color developer and the pigment. CONSTITUTION:In a color developing layer containing an organic color developer and a pigment, 50wt.% calcium carbonate as the pigment is contained and 5-30wt.% kaolin having an average aspect ratio (a diameter/thickness ratio of a surface of planar particle : diameter/thickness) of 13-23 is contained per the total weight of the organic color developer and the pigment. The use of the organic color developer produces a pressure-sensitive recording color developing paper forming an image superior in light resistance, water resistance, and stability with time. In addition, the aforesaid weight of the calcium carbonate contained in the color developing layer enhances ink set properties. Furthermore, the above ratio of the kaolin with the aforesaid average aspect ratio contained in the color developing layer eliminates the roughness of a coated surface caused by the compounded calcium carbonate, enhances a sliding property, and realizes a superior printability.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a colored paper for pressure-sensitive copying paper using an organic coloring agent, and in particular to a colored paper for pressure-sensitive copying paper with improved slipperiness and printability. It is related to.

``Prior Art'' Pressure-sensitive copying paper uses a microcapsule composition mainly composed of microcapsules containing oil droplets in which an electron-donating organic coloring agent (hereinafter simply referred to as coloring agent) is dissolved, on one side of a support. A coloring agent composition containing an electron-accepting coloring agent (hereinafter simply referred to as coloring agent) as a main component that changes color when it comes into contact with the coloring agent is applied to the coated clay paper and one side of the support. , an inner paper coated with a microcapsule composition on the opposite side, and a lower paper coated with a coloring agent composition on one side of the support. It has been put into practical use as a copy cent by combining the paper and the bottom paper in that order. Also, self-coloring pressure-sensitive copying paper, in which a coloring agent and a coloring agent are coated on the same side of a support to enable pressure-sensitive recording on a single sheet, is also well known as a form of pressure-sensitive copying paper.

Coloring agents for such pressure-sensitive copying paper include inorganic coloring agents such as acid clay, activated clay, acpulgite, zeolite, hentonite, silica, aluminum silicate, and phenol.
Phenol polymers such as aldehyde polymers and phenol-acetylene polymers, and organic coloring agents such as aromatic carboxylic acids or polyvalent metal salts thereof are known.

Among these, organic coloring agents have a higher coloring ability than inorganic coloring agents, and have the advantage that the resulting colored image does not suffer from a decrease in recorded density due to moisture adhesion or normal file storage. Further, by incorporating calcium carbonate as a pigment stopper in the coloring layer using an organic coloring agent, the above-mentioned performance is further improved and the inkescent property is improved.

However, when calcium carbonate is used as a pigment,
The resulting colored paper for pressure-sensitive copying paper has poor slip properties, is difficult to handle, and has poor printing workability. In order to solve this problem, a method has been proposed in which Kurji is used as a part of the pigment (Japanese Patent Application Laid-Open No. 63-47191), but this method has a new problem of reducing the coloring properties of colored paper. Due to the accompanying drawbacks, the current situation is that satisfactory results are not always obtained.

"Problems to be Solved by the Invention" The present invention solves the above problems and provides a colored image with excellent light fastness, water resistance, and stability over time, as well as good slippage on the coated surface and excellent handling and printability. The object of the present invention is to provide a colored paper for pressure-sensitive copying paper.

"Means for Solving the Problem" The present invention provides a coloring paper for pressure-sensitive copying paper provided with a coloring layer containing an organic coloring agent and a pigment, in which calcium carbonate is used as the pigment, the organic coloring agent and the pigment are Kaolin containing 50% by weight or more based on the total weight of the kaolin and having an average aspect ratio (ratio of the plane diameter and thickness of the plate-like particles: diameter/thickness) of 13 to 23.
This is a colored paper for pressure-sensitive copying paper, characterized in that it contains ~30% by weight.

"Function" In the present invention, by using an organic coloring agent, a coloring paper for pressure-sensitive recording paper with excellent light fastness, water resistance, and stability over time of colored images can be obtained. By containing calcium carbonate in the coloring layer in an amount of 50% by weight or more based on the total weight of the coloring layer, the inkescent property is improved.

In addition, by including kaolin with an average aspect ratio of 13 to 23 in 5 to 30% by weight based on the total weight of the organic coloring agent and pigment, the roughness of the painted surface caused by the combination of carbonic acid russoum can be eliminated. , a colored paper for pressure-sensitive copying paper with good slip properties and excellent printability has been realized.

When kaolin is contained in the coloring layer, a powder falling phenomenon is likely to occur due to the weak bonding force between crystals in the plate-like particles. However, by using kaolin having an average aspect ratio of 13 to 23, more preferably 15 to 20, this phenomenon can be prevented and the slipperiness can be improved.

If the average aspect ratio of kaolin is less than 13, ink adhesion will be poor, and if it exceeds 23, it will be necessary to increase the amount of binder to sufficiently adhere the kaolin, resulting in poor ink adhesion. bring about harm.

Such thin plate-shaped kaolin having an aspect ratio of 13 or more is produced by subjecting kaolin to a peeling treatment.

Note that two or more types of kaolin having different aspect ratios, whiteness, etc. may be used in combination.

The amount of kaolin used is 5 to 30% by weight, preferably 10 to 25% by weight, based on the total weight of the organic coloring agent and pigment.

If it is less than 5% by weight, the effect of improving slipperiness will be insufficient, while if it is used in an amount exceeding 30% by weight, a decrease in whiteness and color density will occur.

Usually, the pigment in the coloring layer is 50% by weight or more of the total solid content of the coloring layer.
95% by weight, an organic coloring agent of 1% to 20% by weight, and a binder of 1% to 40% by weight.

Examples of the organic coloring agent used in the present invention include:
Special Publication No. 49-10856, Special Publication No. 5125174,
Benzoic acid, p-tert-butyl-benzoic acid, 4-methyl-3-nitrobenzoic acid, salicylic acid, 3-phenylsalicylic acid, 3-cyclohexyl as described in JP-A-41-55410 etc. salicylic acid, 3-ter
tert-butyl-5-methylsalicylic acid, 3.5-diter
t-Butylsalicylic acid, 3-methyl-5-undylsalicylic acid, 3-phenyl-5-(α α-dimethylhensyl)salicylic acid, 3-cyclohexyl-5-(α,
α-dimethylhensyl)salicylic acid, 3-(α,αdimethylhensyl)-5-methylsalicylic acid, 35-seisochlorohexylsalicylic acid, 3,5-di(α-methylpencyl)salicylic acid, 35-di(α,α- dimethylhensyl) salicylic acid, 3-(α-methylhensyl)-5-(
α, αdimethylpencil) salicylic acid, 4-methyl 5-
Cyclohexylsalicylic acid, 2-hydroxy 1-benzyl-3-naphthoic acid, 1-hencyyl-2-hydroxy-3-naphthoic acid, 3-hydroxy-5-cyclohexyl-2-naphthoic acid, 2-hydroxy-4- [Aromatic carboxylic acids such as (4-carboxy-5-hydroxy)phenylcy-1-naphthoic acid and salts of these with polyvalent metals such as zinc, aluminum, magnesium, calcium, and cobalt; Japanese Patent Publication No. 40-9309, Special Public Service 1977-2
6,6'-methylenebis(4-chloro-m-
Phenol compounds such as (cresol); Phenol-aldehyde resins such as p-phenylphenol-formaldehyde resin, phenol-acetylene resins such as p-tert-butylphenol-acetylene resin, and polyvalent metal salts thereof: maleic acid- Acidic polymers such as rosin resins, styrene, ethylene or copolymers of vinyl methyl ether and maleic anhydride: Japanese Patent Publication No. 4
No. 8-8215, Special Publication No. 488216, Special Publication No. 52-
Examples include polymers of aromatic carboxylic acids and aldehydes or acetylenes as described in No. 1326, and polyvalent metal salts thereof.

Among these organic coloring agents, aromatic carboxylic acids and their polyvalent metal salts, phenolic resins and their polyvalent metal salts, copolymers of aromatic carboxylic acids and aldehydes or acetylene, and their polyvalent metal salts are particularly useful. Preferably used.

More than one type of these coloring agents may be used in combination.

The coating solution may also contain binders (adhesives) such as starch, casein, gum arabic, carboxymethyl cellulose, polyvinyl alcohol, styrene-butadiene co-'M combination latex, vinyl acetate latex, etc., if necessary.

In addition, inorganic pigments such as zinc oxide, magnesium oxide, titanium oxide, aluminum hydroxide, magnesium sulfate, calcium sulfate, etc. may be used in combination within the range that does not impede the effects of the present invention, and various auxiliaries known in the field of colored paper manufacturing may be used as appropriate. It can also be added.

The method for preparing the coating liquid for forming the colored layer is not particularly limited, and may be prepared as appropriate. For example, a method in which a coating liquid obtained by mechanically dispersing an organic coloring agent in water together with an inorganic pigment, a binder, a dispersant, and other additives is applied to a support;
Alternatively, a coating liquid obtained by dissolving a coloring agent in an organic solvent and emulsifying it in water and adding an inorganic pigment, a binder, and other additives is applied to the support, or a coating liquid obtained by mixing the two. A method of coating on a support is used. As the organic solvent for the coloring agent, aliphatic or aromatic esters,
Examples include biphenyl derivatives, naphthalene derivatives, biphenylalkanes, and the like.

Specifically, methyl amyl acetate) (1,3 dimethyl butyl acetate), 2-ethyl butyl acetate,
2-ethylhexyl acetate, amyl propylate, 1so-butyl-1so-butyrate, 2.2.4-
1-trimethyl-1,3-bentanediol monoisobutyrate, 2,2.4 trimethyl-1,3-bentanediol monoisobutyrate, 2.2. '41 remethyl-1
, 3bentanediol diisobutyrate, 2,4 dimethyl-2,4-bentanediol diacetate, 2,2-
dimethyl-1,3-butanediol diisobutyrate,
2-Methyl-2,4-bentanediol dipropionate, 2,3,3,4-tetramethyl-2,4-bentanediol monoacetate, amyl lactate, 2-methylbiphenyl, 3-methylbiphenyl, 3.3- Dimethylbiphenyl, 24-dimethylbiphenyl, 2,6
-dimethylbiphenyl, 2. ．． 4.6 Trimethylbiphenyl, cyclohexylbenzene, bicyclohexylbenzene, monoisopropylbiphenyl, monoisopropylnaphthalene, diisopropylnaphthalene, 1-isopropylphenyl-2-phenylethane, 1-isopropylphenyl-1-phenylethane, 1.1 -ditolylethane, 1-ethylphenyl-1-phenylethane,
Examples include 1-phenyl-1-xylylethane. A poor solvent such as a petroleum distillate having a boiling point of 150° C. to 310° C. can also be used in combination with these solvents as a diluent.

The coloring layer coating solution thus prepared is applied to a support such as paper, synthetic paper, or film using a conventional coating device such as an air knife coater, plate coater, roll coater, size press coater, curtain coater, or short dwell coater. It is coated and finished as colored paper for pressure-sensitive copying paper.

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

Example 1 [Preparation of coloring layer coating solution] 20 parts of a 25% aqueous dispersion of 3,5-di(α-methylbenzyl)zinc salicylate atomized by a sand mill, 70 parts of calcium carbonate, 10 parts of zinc oxide, average Mix and disperse 15 parts of kaolin with an aspect ratio of 18 and 100 parts of water, and then add 10% aqueous solution of 10% polyvinyl alcohol (trade name: PVA110, manufactured by Kuraray ■) as a binder.
0 parts and carboxy-modified SBR latex (product name:
5N-307, manufactured by Sumitomo Naugatac) 10 parts, water 20
0 parts were mixed to obtain a dispersion.

[Manufacture of colored paper for pressure-sensitive copying paper]

The above coloring layer coating solution was applied to one side of a 40 g/% base paper using an air knife coater so that the dry weight was 6.0 g/rn', and was dried to obtain a coloring paper for pressure-sensitive copying paper.

Example 2 [Preparation of coloring layer coating solution] 5 parts of 3.5-di(α-methylhensyl)zinc salicylate was mixed with 20 parts of 1-isopropylphenyl-1-phenyl ethane.
The mixture was heated and dissolved at 90°C.

Add this to 1% polyvinyl alcohol (product name: PVA
210, manufactured by Kuraray ■) into 100 parts of an aqueous solution, and further added 0.0% of 1.0% sodium lauryl sulfate as a surfactant.
Add 1 part and use a homomixer until the average diameter of the emulsion is 2.0μ.
An emulsion was prepared so that the amount of

Next, 70 parts of calcium carbonate, 10 parts of aluminum hydroxide, 15 parts of kaolin with an average aspect ratio of 18, and 100 parts of water.
After mixing and dispersing the above emulsion, 100 parts of a 10% polyvinyl alcohol (product name: PVA 105, Kuraray Co., Ltd.) aqueous solution as a binder and 100 parts of a 20% aqueous solution of oxidized modified starch were mixed. A dispersion liquid was obtained.

[Manufacture of colored paper for pressure-sensitive copying paper]

The coloring layer coating solution was coated on one side of a 40 g/m base paper using a blade coater to give a dry weight of 7.0 g/m and dried to obtain a coloring paper for pressure-sensitive copying paper.

Example 3 A colored paper for pressure-sensitive copying paper was obtained in the same manner as in Example 1 except that kaolin with an average aspect ratio of 14 was used instead of kaolin with an average aspect ratio of 18.

Example 4 In Example 2, instead of using 15 parts of kaolin with an average aspect ratio of 18, 25 parts of the same kaolin (23,
A colored paper for pressure-sensitive copying paper was obtained in the same manner as in Example 2, except that 6% by weight was used.

Example 5 Example 2 except that instead of using 15 parts of kaolin with an average aspect ratio of 8, 7.5 parts of kaolin with an average aspect ratio of 15 and 7.5 parts of kaolin with an average aspect ratio of 20 were used. A colored paper for pressure-sensitive copying paper was obtained in the same manner as in Example 2.

Example 6 Example 1 except that instead of using 15 parts of kaolin with an average aspect ratio of 18, 7.5 parts of kaolin with an average aspect ratio of 15 and 7.5 parts of kaolin with an average aspect ratio of 20 were used. A colored paper for pressure-sensitive copying paper was obtained in the same manner as in Example 1.

Example 7 Example 1 except that instead of using 15 parts of kaolin with an average aspect ratio of 18 in Example 1, 35 parts of kaolin with an average aspect ratio of 18 (corresponding to 29.2% by weight) was used. A colored paper for pressure-sensitive copying paper was obtained in the same manner as above.

Comparative Example 1 A colored paper for pressure-sensitive copying paper was obtained in the same manner as in Example 1 except that kaolin with an average aspect ratio of 10 was used instead of kaolin with an average aspect ratio of 18.

Comparative Example 2 In Example 1, instead of using 15 parts of kaolin with an average aspect ratio of 18, 50 parts (37 parts) of the same kaolin was used.
A colored paper for pressure-sensitive copying paper was obtained in the same manner as in Example 1, except that 4% by weight was used.

Comparative Example 3 A colored paper for pressure-sensitive copying paper was obtained in the same manner as in Example 2, except that instead of using 15 parts of kaolin with an average aspect ratio of 18, 15 parts of calcium carbonate was further added. .

Regarding the 10 types of colored paper for pressure-sensitive copying paper obtained as described above, the color development, abrasion resistance (staining due to roughness of the coated surface), slipperiness, and ink receptivity (misdots) were evaluated as follows. The results are shown in Table 1.

[Color development]

The colored paper and the top paper were stacked so that the coated surfaces faced each other, and the paper was passed through a super calendar to develop color. After 1 hour, the color density was measured using a Maches densitometer (the higher the value, the better the color development).

[Abrasion resistance]

The colored paper and the top paper were placed one on top of the other so that the coated surfaces faced each other, and rubbed together five times under a load of 4 kg/n (4 kg/n), and the degree of colored staining on the coated surface of the colored paper was visually determined.

[Slip property]

Layer the colored paper and top paper so that the coated surfaces are facing each other, and measure the friction coefficient between them using MODE manufactured by KAYENESS.
Thread load 200g with LD-1055 measuring machine,
Measurements were made at a speed of 0.5 feet/min. Due to handling suitability,
The static friction coefficient is preferably 0.65 or less.

[Ink receptivity]

J, TAPPI Paper Pulp Test Method, Na, 2dmr Paper Gravure Printing Suitability Test Method (Printing Bureau Type)" The printed matter was evaluated visually and by enlarged photography.

Table 1 [Evaluation] ○: Excellent ×: Inferior "Effect" As is clear from the results in Table 1, the colored paper of the present invention has excellent abrasion resistance, slipperiness, ink receptivity, It can be seen that it has excellent color development.

Claims (1)

[Claims] A coloring paper for pressure-sensitive copying paper provided with a coloring layer containing an organic coloring agent and a pigment, containing calcium carbonate as the pigment in an amount of 50% by weight or more based on the total weight of the organic coloring agent and the pigment,
and 5 to 30% by weight of kaolin having an average aspect ratio (ratio of diameter and thickness of the plane of plate-like particles: diameter/thickness) of 13 to 23.
A colored paper for pressure-sensitive copying paper comprising: