JP2002178622A - Method for gravure printing using aqueous gravure ink and printed matter printed thereby - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for printing by using an aqueous gravure ink and a desired hue in a printed matter printed by the same. SOLUTION: The method for gravure printing by using the aqueous gravure ink comprises the steps of arbitrarily applying (lap printing) six primary color inks of yellow, red, blue, orange, green and purple by using plates selecting halftone percentage, so that eight colors o the six primary colors of the yellow, red, blue, orange, green and purple by adding two colors of white and black are used as fundamental material ink, while the number of lines of meshes is 200 to 400 lines, a depth of the plate is 10 to 17 μm, and the plate selecting the halftone percentage is used so that object hues are obtained at the respective colors. Thus, since the desired hues are obtained, a problem of a residual ink such as a special color is eliminated, and a printing cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gravure printing method using an aqueous gravure ink and a printed matter printed by the printing method. More specifically, the present invention relates to a method for replacing a conventional organic solvent type (oil-based) gravure ink. The present invention relates to a gravure printing method using an aqueous gravure ink and a printed matter printed by the printing method.

[0002]

2. Description of the Related Art In conventional organic solvent type (oil-based) gravure printing, the following printing method is used to reproduce hue. The first method uses five colors, which are the sum of the three primary colors of yellow, red, and blue, and two colors of black and white, as basic inks, while the plate used is exclusively low-mesh (around 175 lines),
A desired color is printed by multiplying (overprinting) a deep plate (depth of 18 to 30 μm) using a plate in which the dot percentage is selected so that each color has the desired hue. The method is basic, but in this method, in the case of orange (yellow and red), green (yellow and blue) and purple (red and blue), it becomes cloudy, There is a problem that a clear hue (color rendering property) that meets customer requirements cannot be obtained. In addition, the oil-based gravure ink has a problem that the halftone dot of the printed matter becomes unclear due to the fast drying property as a characteristic, and the hue varies.

As a second method, instead of the above-mentioned multiplying method, there is a method in which the above-mentioned raw material inks are previously kneaded to form a special color and then printed using a low-mesh deep plate. In the case of purple, the problem of cloudiness remains the same.

Therefore, as a third method, instead of the above-described raw material inks, eight basic colors, that is, six primary colors of yellow, red, blue, orange, green, and purple and two colors of black and white, are used as basic raw material inks. There is a method of printing using the first method, but the problem that the halftone dots of the printed matter are unclear and the hue varies due to the quick drying of the oil-based gravure ink remains unchanged.

[0005] Eventually, as a fourth method, yellow, red, blue,
Eight colors, including the six primary colors of orange, green, and purple, and two colors of black and white, are used as basic inks. According to the hue required by the customer, for example, orange is orange and yellow or red, and green is Green and yellow or blue,
In the purple system, a method of selectively mixing purple and red or blue to create a special color and printing it using a low-mesh deep plate is now customary. However, in this method, the cost is greatly increased due to the problem of increasing the number of special colors and the number of plates, the problem of changing ink before printing, the time required for changing the plate, and the problem of increasing the residual color ink after printing. There is a problem and it is the biggest economic bottleneck.

On the other hand, recently, attention has been paid to a printing method using an aqueous gravure ink that does not use an organic solvent due to environmental problems in a printing factory, and it is considered that the printing method will move in this direction in the future. However, in the current aqueous gravure printing method, as long as the above oil-based gravure printing methods 1 to 4 are inherited, not only the same problem as described above occurs but also the essential drawbacks of the aqueous gravure ink. There is a new problem.

That is, even if the ink is made water-based, the conventional plate (low mesh having about 175 lines, plate depth of 18 to 3) can be used.
0 μ), not only the printing speed is reduced due to poor drying properties of the aqueous ink, but also the halftone dots of the printed matter are blurred and the desired hue cannot be obtained. Plate jam due to poor resolubility in solvent,
Plate cylinder stains, doctor lines, plate fog, etc. occur, and the desired hue cannot be obtained.

In addition, in the second and fourth methods of the conventional oil-based gravure printing, the printing method based on kneading (special color) of the raw material inks, the water-based ink has the same poor re-solubility, so that the printing after printing is difficult. There is a fatal problem in terms of cost that it is difficult to reuse the residual ink of the special color. Thus, a gravure printing method using an aqueous gravure ink has not yet been established.

Therefore, the present inventors have proposed a new proposal (Japanese Patent Application No.
No. 211532), but it is still necessary to improve the hue reproducibility of orange, green, and purple.

[0010]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above points, and a gravure printing method using an aqueous gravure ink and a method for producing a special color ink in a printed matter printed by this method. It is an object of the present invention to provide a water-based gravure printing method capable of obtaining a hue (color rendering property) that meets a customer's request without any problems and a printed matter printed by this method.

[0011]

According to a first aspect of the present invention, there is provided a gravure printing method using an aqueous gravure ink.
Eight colors, including the six primary colors of blue, orange, green, and purple, and two colors of black and white, are used as the basic raw material inks. On the other hand, a plate having 200 to 400 mesh lines and a plate depth of 10 to 17 μm And printing a desired hue by arbitrarily multiplying (overprinting) these primary color inks using a plate in which a halftone percentage is selected so that each color has a desired hue. It is.

Further, in the invention according to claim 2,
In the gravure printing method performed using the water-based gravure ink, to give a reddish orange, multiply the orange with red, and to give a yellowish orange, multiply the orange with yellow, If you want a bluish green color,
Multiply blue with green and give yellowish green, multiply yellow with green, and get reddish purple, multiply red with purple and blueish. In the case of producing purple, it is characterized in that purple and blue are multiplied.

Further, in the invention according to claim 3,
In a gravure print using an aqueous gravure ink, the six primary colors of yellow, red, blue, orange, green, and purple, and two colors of black and white
8 colors are used as the basic raw material inks,
200 to 400 mesh lines, plate depth 10 to 17
Aqueous gravure printed in a desired hue by arbitrarily multiplying (overprinting) the primary color inks using a plate in which the halftone percent is selected such that the desired hue is obtained for each color on the μ plate. A water-based gravure print printed using ink.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a gravure printing method using an aqueous gravure ink, a technique that can obtain a hue (color rendering property) required by a customer without producing a special color ink as in the conventional oil-based gravure printing method is important. is there. Therefore, one of the constituent requirements of the present invention is that the primary colors of the aqueous gravure ink used as the basic raw material ink are 6 colors of yellow, red, blue, orange, green and purple.
That is to say, eight colors are obtained by adding two colors of primary color, ink and white. The reason is that, as mentioned above, yellow, red, yellow, blue, and red are used to obtain the orange, green, and purple hues of the three primary colors of yellow, red, and blue, and black and white, respectively. Although blue is used, the color becomes cloudy, and the hue (color rendering properties) required by the customer cannot be obtained. On the other hand, in the present invention, in order to obtain orange, green, and purple hues, orange and yellow or red, green and yellow or blue, and purple and red or blue are selectively used in combination. In this case, a clear hue required by the customer is obtained without becoming cloudy.

The second requirement is that plate making technology is important. That is, even if the above-mentioned water-based ink is used, as described above, in the conventional plate, the halftone dot of the printed matter is blurred (the dot reproducibility is poor) due to poor drying property as an essential disadvantage of the water-based ink, and the desired hue Are not obtained, and furthermore, the printing ink becomes defective due to poor resolubility in water or a water / alcohol solvent, plate cylinder stains, doctor lines, plate fogging, etc. occur, and a desired printed matter cannot be obtained. .

However, when the number of lines is 200 to
400 lines, preferably 350 lines, plate depth shallow plate 10
The use of a plate made at ~ 17μ, preferably 12-13μ eliminates all of the problems associated with the conventional plate described above. This is the same for all types. When the number of lines is less than 200 lines, halftone dots of the printing ink coating film are blurred due to poor drying properties of the aqueous ink, and a desired hue cannot be obtained.

On the other hand, when the number of lines is more than 400, the bank surrounding the cells of the gravure plate (intaglio) is cut off, and printing cannot be performed because halftone dots of the printing ink coating film are not formed. Alternatively, since the halftone dots become small, the color tone width becomes narrow, and a desired hue cannot be obtained.

On the other hand, when the plate depth is greater than 17 μm, plate jams, plate cylinder stains, doctor lines, plate fog, etc. occur due to poor resolubility of the aqueous ink in the water solvent. Furthermore, due to poor drying properties of the water-based ink, not only the printing speed is reduced, but also the halftone dots of the printed matter are blurred and a desired hue cannot be obtained. Further, the cost increases because the amount of ink used increases. On the other hand, when the plate depth is smaller than 10 μm, unevenness occurs in the plate making, so that the printing color tone varies. Alternatively, color density cannot be obtained because the printed coating film is thin.

Next, the third requirement is to use the above-mentioned plate, select a dot percentage for each color, and print with the above-mentioned raw material ink in order to obtain a desired hue. The larger the numerical value of the halftone dot percentage of the used plate, the more the color is emphasized. The reason is that, as described above, the oil-based gravure ink has a problem that the halftone dot of the printed matter becomes unclear and the hue varies due to the quick drying property of the ink. Therefore, in oil-based gravure printing, it has become customary to make and print a special color ink.

On the other hand, in this requirement, the combination of the water-based ink and the new plate for the water-based ink makes the dot reproducibility of the printed matter much better than that of the oil-based one. Hue management tailored to the customer's requirements can be achieved for the first time by this method.

In other words, as a hue management technique using a gravure plate (intaglio), a value obtained by measuring the ratio of the area of a cell surrounded by a bank to a fixed area of the plate by a dot meter is called a dot percentage, and for each primary color ink, In water-based gravure prints printed using plates with varying dot percentages, the dot size (area) of the ink that matches the dot percentage of the plate can be obtained with much higher reproducibility than in the case of oiliness. I understand.

Accordingly, in order to obtain the hue required by the customer, it is necessary to obtain orange and yellow or red plates for orange, green and yellow or blue plates for green, and purple and red for purple. Alternatively, if a blue plate is selectively superimposed and printed by using a plate in which the dot percentage is changed, the printed material is visually desired as an aggregate of dots for each primary color ink used. Is obtained. For example, if the hue requested by the customer is reddish orange, a color chart unique to each company prepared in advance (a version in which halftone dots of the orange primary color are divided into ten to ten percents from 100% to 3% and the same as the red primary color) Select the halftone dot percentage of orange and the halftone dot percentage corresponding to the redness (for example, 100% orange and 50% red) from among the color swatches that were overprinted using the color plate, and set them as plate making materials. The desired hue can be reproduced by performing overprinting using the prepared plate.

As described above, the requirement of the present invention is that the three requirements are combined organically as one requirement, so that an aqueous gravure ink can be used as an optimal printing method (a method that does not increase the number of special color inks). For the first time, it was possible to find industrial value.

[0024]

Example 1 A biaxially stretched polypropylene film (20 μm) was used, and a commercially available aqueous ink and a diluent of 50/30/20% of water / ethanol / isopropyl alcohol were used. Printing ink, yellow, red, blue, orange, green, purple 6 primary colors and black ink, 2 colors were added to make 8 colors. On the other hand, as the printing plate, 350 lines by laser method, plate depth A plate of 13 μm was made and gravure printing of eight colors and eight plates was performed.

[0025]

COMPARATIVE EXAMPLE 1 A conventional oil-based gravure plate was produced by using a laser type plate having a line number of 175 lines and a plate depth of 18 μm, and printing was performed in the same manner as described above. As a result, in Comparative Example 1 using the conventional plate, not only the printing speed is reduced (70 m / min) due to poor drying property, which is an essential drawback of the aqueous ink, but also the halftone dots of the printed matter are blurred. Plate jam due to poor re-solubility of water-based ink which is an essential disadvantage, plate cylinder stain, doctor line,
In contrast to the occurrence of plate fogging and the like, the desired printed matter was not obtained, the method of the present embodiment not only solved all the above-mentioned problems when the conventional plate was used, but also, in particular, The point reproducibility was much better than that of the oil-based ink.

[0026]

Example 2 The basic color of the aqueous gravure ink was yellow,
Red, blue, orange, green, purple 6 primary colors and sum of black and white 8
Color (Toyo Ink Co., Ltd. Akwa Ecole JW220)
Is used as a raw material ink, and water / ethanol / isopropyl alcohol = 50/30/20 (AQ602F manufactured by Toyo Ink Co., Ltd.) is mixed with each as a diluting solvent to prepare a printing ink having a desired viscosity. On the other hand, aqueous gravure printing As a printing plate, a printing plate was prepared in which the number of halftone dots was changed from 100% to 3% in small increments at a plate depth of 13μ with a line number of 350 lines by a laser plate making method. Is orange and red and orange and yellow, green is green and yellow and green and blue, purple is purple and red and purple and blue,
Printed material by each combination (color chart)
Was prepared.

[0027]

[Comparative Example 2] Using the conventional method (the first method in the text),
Color charts are made from five basic colors of water-based gravure ink, three primary colors of yellow, red, and blue, and two colors of black and white, and red and blue for orange, yellow and blue, and purple for green. Was prepared by crossing each of red and blue.

Then, a clear hue required by the customer was selected from the color chart of Example 2 as a combination of the basic color of the ink and the dot percentage, and compared with the hue selected from the color chart of Comparative Example 2. As a result, in all of the orange, green, and purple colors, Comparative Example 2 was all turbid, and the desired clear hue was obtained by the method of Example 2.

Table 1 summarizes examples of the conventional example (Comparative Example 2) for the customer requested colors 1 to 6 and the primary color combination examples of Example 2 according to the present invention, and the obtained hue evaluations.

[0030]

[Table 1]

[0031]

As described above, the present invention provides a gravure printing method using an aqueous gravure ink and a printed material printed by this printing method, as basic inks of yellow, red, blue, orange, green, and violet. Eight colors, which are the sum of the six primary colors and two colors of black and white, are used.
A halftone dot is not blurred by arbitrarily multiplying the primary color inks using a plate having a depth of 10 to 17 μm and a halftone percentage selected so that each color has a desired hue. (Good dot reproducibility), the obtained hue does not become cloudy (clear), and a desired printed matter free of plate cylinder stains, doctor lines and plate fogging during printing can be obtained.

As a result, the problem of residual ink such as a special color is eliminated, and the printing cost can be reduced. Further, since the problem of ink change and plate change is eliminated, work efficiency is improved, and in this respect, printing cost can be reduced.

Claims (3)

[Claims] 1. A gravure printing method using an aqueous gravure ink, wherein eight basic colors of yellow, red, blue, orange, green, and violet and two colors of black and white are used as basic raw material inks. On the other hand, these primary color inks are arbitrarily applied using a plate having a mesh number of 200 to 400 lines, a plate depth of 10 to 17 μ, and a halftone percent selected so that each color has a desired hue. A gravure printing method using an aqueous gravure ink, wherein a desired hue is printed by combining (overprinting). 2. To produce a reddish orange color, multiply the orange color by a red color, and to produce a yellowish orange color, multiply the orange color by a yellow color, and add a bluish green color. If you want to emit green, add blue to green, if you want yellowish green, multiply green with yellow, if you want reddish purple, multiply purple with red, The gravure printing method using the aqueous gravure ink according to claim 1, wherein in the case of producing a bluish purple, the aqueous gravure ink according to claim 1 is used by applying blue to blue. 3. In a gravure print using an aqueous gravure ink, eight basic colors of six primary colors of yellow, red, blue, orange, green and purple and two colors of black and white are used as basic raw material inks. On the other hand, the primary color ink is arbitrarily selected using a plate having a mesh line number of 200 to 400 lines, a plate depth of 10 to 17 μ, and a halftone dot percentage selected so that each color has a desired hue. Aqueous gravure printed using an aqueous gravure ink printed in a desired hue by multiplying (overprinting).