JPH07101145A - Coupling sheet for carbonless copy paper and production thereof - Google Patents

Abstract

PURPOSE:To more inexpensively obtain a coupling sheet for carbonless copy paper showing color forming properties comparable to those of a conventional one. CONSTITUTION:Coupling ink is applied to form a coupling layer. At this time, in order to increase coating thickness to obtain the objective thickness (5mum or more) of a dry film by one printing, mesh or grinding processing is applied to the surface of a plate material (rubber plate, resin plate) used by a type printing, dry offset or flexographic system to increase the transfer amt. of ink. In a general printing plate, film thickness can be obtained by two-time or more overlap printing. In order to obtain a porous dry film, the ratio of pigment in ink is increased and pigment having a large average particle size is selected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prints a color-developing ink using a printing method such as letterpress, dry offset, offset, flexo, gravure and screen, and increases the film thickness of a coating film, and a capsule. The present invention relates to a color-developing sheet for carbon-free copying paper having a color developability equivalent to that of a commercially available (conventional) carbon-free copying paper by improving oil permeability and a method for producing the same.

[0002]

2. Description of the Related Art Conventional copying paper includes carbon copying paper obtained by dispersing a coloring dye and printing it, or microcapsules containing a coloring dye applied to the surface of the paper and containing a coloring dye. There is known a so-called carbonless copying paper obtained by coating the back surface of the. With the above carbon copy paper, it is possible to print only on the parts required for copying by spot printing, but since there is also color in itself, it will stain your hands and aesthetic points of the product. There is also a problem.

For this reason, carbonless copy paper is being used in large amounts as copy paper today. However, in the case of conventional carbonless copy paper, since the color-forming capsule and the color developer are applied to the entire surface, it is necessary to print the desensitizing ink on the areas where you do not want to copy to prevent color development. Also, since the capsule is destroyed by cutting, the cutting surface of the bound copy book turns blue,
There is an inconvenience that spoils the aesthetics of the product.

In order to solve all of these problems, a method of spot-printing with a color-developing ink only on the portion of the carbonless copying paper where copying is required has been considered and is used in some products. . As the developer ink, ink using clay (activated clay) is known, and in order to further improve the developer performance, phenol resin, aromatic carboxylic acid or their anhydrides, metal compounds and alkaline substances are used. It has been reported that the improved color developing inks (Japanese Patent Publication No. 49-27134).

[0005]

However, in such conventional printing methods, particularly letterpress, dry offset, and flexo methods, it is usual that the thickness of the printed coating film is printed to about 1 to 3 μm. The constitution of the color layer is incomplete, the color developing ability is not sufficient, and it is not possible to obtain the same color developability as that of commercial carbon copy paper. This is because the ink contains a large amount of vehicle components (resin varnish) and the printed coating film is less likely to be porous, so the penetrability of the capsule oil is poor, the coloring dye does not react 100% efficiently, and the surface layer of the coating surface Only the color is developed. As a result, the print density is low, and because the capsule oil does not fully penetrate, thickening of the lines and back wandering (back phenomenon) to the capsule coated surface side occur.

On the other hand, with commercially available carbonless copying paper, about 3
% Of a colorless dye (eg, triphenylmethane / phthalide-based or fluorane-based compound) dissolved in a capsule oil (eg, alkylnaphthalene, diallyl-alkane, alkylated biphenyl, hydrogenated terphenyl, etc.) 3 ~ 6μ size capsules are coated. When the capsule is broken due to type pressure or the like, the oil and dye in the capsule flow out, and the developer layer that reacts with the oil has a porous film thickness of about 6 μm so that the capsule oil can easily penetrate. ing. Therefore, the reaction from the upper layer to the lower layer of the color developing layer is in a state of efficiently reacting, and thus, a sufficient print density can be obtained, but on the other hand, the color developing layer is coated over the entire surface. Since it is applied by the technique, there are many unnecessary developer layers that are not used for developer, which causes a cost disadvantage.

The present invention has been made in view of such conventional problems, and a color-developing sheet for a carbon-free copy paper which exhibits a color developing property equivalent to that of the above-mentioned commercially available carbon-less copy paper at a lower cost, and the same. It is intended to provide a manufacturing method.

[0008]

In order to solve the above problems, in the present invention, a color-developing ink is printed to form a color-developing layer. At this time, a target dry coating film thickness is obtained by printing once. Sa (5μ
In order to increase the film thickness, the surface of the plate material (rubber plate, resin plate) used in letterpress, dry offset, flexographic method, etc. is meshed or polished to increase the film thickness.
Improve the transfer amount of ink. Further, in a general printing plate, the desired film thickness can be obtained by performing overprinting twice or more. Further, the gist of the present invention is to increase the ratio of the pigment in the ink and select a pigment having a large average particle size in order to obtain a porous dry coating film.

[0009]

In the above structure, the color-developing sheet created is
When the thickness of the dry coating film is 5 μm or more, the required color developability (equivalent to the commercially available carbonless copy paper) can be obtained, as will be supported by the examples described later. Further, the composition of the color developing ink used in the present invention is appropriately selected from materials generally used as printing inks, and the manufacturing method thereof is not limited at all, but as a preferable material, the color developing agent is phenol-based. Resins and salicylic acid derivatives are used, and oil components such as letterpress inks include alkylnaphthalene, diarylalkanes, oils such as hydrogenated terphenyl, glycol solvents, and water-based inks such as water and ethanol. For gravure and flexo ink, toluene, xylene, ethyl acetate, ethanol, MEK, MIBK, etc. are selected according to the printing method.

As the pigment, clays such as titanium oxide, zinc oxide, calcium oxide, calcium carbonate, magnesium carbonate, kaolin, and vinegar clay are used, and pigment particles having a particle diameter of 1 μm or more are preferable.

These ink compositions are printed on a substrate in a letterpress,
Dry offset, offset, gravure, flexo,
Printing is performed by a printing method such as screen printing as needed. In particular, calcium carbonate having a particle size of 1 μm to 2 μm and having an appropriate tack and fluidity has excellent ink transfer properties and a printed matter having a thicker film can be obtained.

[0012]

EXAMPLES The present invention will be described in detail below with reference to examples.

[Example 1] << Preparation of letterpress color development ink >> 4 parts of salicylic acid derivative metal salt SAS296 (Nisseki / diallylethane) dissolved in 4 parts by heating, light calcium carbonate (Takehara chemistry, average particle size 2 μ) and 20 parts were added to form an ink with a three-roll mill.

This color-developed ink is used in a letterpress system to obtain high-quality paper (50
g / m ² ) Spot printing is performed only on the required part, and
The film thickness was adjusted to about 10 μm by using a diaphragm of a printing machine and a mesh resin plate to obtain a color developing sheet having each coating film thickness. The printed matter was dried by applying hot air of about 80 ° C. on the line of the printing machine immediately after printing. Furthermore, overlaying with commercially available carbonless paper (40 g / m ² ),
The color density was investigated using a 2P set copy slip. In addition, commercially available carbonless copy paper, top paper, top paper (40 g
/ M ² ), a lower sheet (40 g / m ² ) was used as a 2P set, and the color density was investigated. The results are shown in Table 1 below.

[0015]

[Table 1] Here, as for the printing color development type property, the same character was struck from above the 2P set with low pressure and high pressure of Olivetti electric typewriter, and the color density was visually determined.

The spot printing density was expressed as an average value at three central portions of a colored circular pattern obtained by dropping a weight having a diameter of 6 mm and a load of 50 g from a height of 35 cm from the 2P set. For the spot printing density, a digital meter (manufactured by Abesetkei) is used. The higher the value, the darker the density. [Example 2] << Preparation of letterpress developer ink >> Alkylphenol novolac type resin 3 parts Polyethylene wax 0.6 part Titanium oxide 2 parts Light calcium carbonate 6 parts Glycol-based solvent 8 parts Fine paper (5
Table 2 below shows the results of investigating the film thickness and color developability in the same manner as in Example 1 by spot printing at 0 g / m ² ).

[0017]

[Table 2] That is, as supported by Tables 1 and 2,
If the film thickness of the color developing layer formed by the color developing ink is 5 μm or more, the same type of color development and spot printing density (1 minute after printing and 60 minutes after printing) as with commercial carbon copying paper can be obtained. It has been found.

[0018]

As described above, according to the present invention, it is possible to provide a color-developing sheet having a porous coating film having a thickness of 5 μm or more. It can be improved to the level of carbonless copy paper coated with color-developing ink. In addition, since spot printing is used to print only the necessary portion, it is not only widely used in copy books and slips, but also at a lower cost, it is possible to secure the same color developability as conventional ones.

Claims (7)

[Claims] 1. A spot-printing method wherein a color-developing ink is printed on a required portion of a substrate to form a color-developing layer, and a coating film of the color-developing layer has a thickness of 5 μm or more. Color developing sheet for carbon copy paper. 2. 0.4 g / m in the dry coating film of the color developing layer.
^The color developing sheet for carbonless copying paper according to claim 1, which contains ^two or more color developing agents. 3. The color ratio of the developer and the resin component in the developer ink to the pigment component including the extender pigment is 1: 2.5 to 1: 1.
7. The color-developing sheet for carbonless copy paper according to claim 1, wherein the range is 7. 4. A color-developing color for carbonless copying paper, characterized in that a color-developing ink is printed on a required portion of a substrate by spot printing to form a color-developing layer having a coating film thickness of 5 μm or more. Sheet manufacturing method. 5. The dry coating film of the color developing layer has 0.4 g / m.
5. The composition according to claim 4, which contains ^two or more developers.
A method for producing a color-developing sheet for carbonless copying paper as described above. 6. The weight ratio of the color developer and the resin component in the color developing ink to the pigment component including the extender pigment is 1: 2.5 to 1: 1.
7. The method for producing a color developing sheet for carbonless copying paper according to claim 4, wherein the range is 7. 7. The printing method used for the spot printing, wherein the surface of a rubber or resin plate used as a plate material is mesh-processed or polished-processed. Method for producing color developing sheet for carbon copy paper.