JP2008255174A - Lithographic ink printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing method which uses process four colors capable of widening a color rendering range (gamut) more than the case in which a Japan color standard ink of the ISO standard is printed, and by which the color range boundlessly nearer to the color reproduction range of RGB is expressed by carrying out the printing with five-color ink by further adding purple ink. <P>SOLUTION: The lithographic ink printing method uses inks selected from five color inks by combining a combination of four color lithographic inks of yellow, rouge, indigo and black, with an ink containing a pigment having a specific purple hue in the lithographic ink printing method using inks selected from the yellow, rouge, indigo and black inks. With respect to three colors excluding black, the yellow ink contains a disazo yellow-based compound as a coloring component, the rouge ink contains a metal lake compound of a rhodamine-based dye as a coloring component, and the indigo ink contains a phthalocyanine-based compound as a coloring component. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a lithographic ink printing method consisting of five colors obtained by adding one violet ink to a lithographic ink printing method consisting of four processes of yellow, red, indigo and black, which are excellent in color reproduction with high saturation. The present invention relates to a lithographic printing method that enables a wider color reproduction region.

  The IT revolution that began in the 1990s has rapidly led the environment surrounding the printing field in the direction of digitization. The workflow of the conventional printing method is composed of a large number of processes such as photographing, positive, scanning, data, design, EPS (Encapsu Lated Post Script), imposition, film, printing plate, and printing. On the other hand, the workflow of a digitized printing method includes processes such as photographing with a digital camera, DTP (Desk Top PubLishing), CTP (Computer Top Plate), and printing. Through digitalization, we succeeded in dramatically shortening the printing workflow compared to conventional printing methods. In addition, with digitalization, “RGB” conversion of submitted data is becoming a standard, and the data to be handled is changing to a wider color reproduction region. In such an environment, “standardization” of the environment surrounding the printing site is an important point, and “Japan Color” is also attracting attention as one means of standardization.

  However, at present, lithographic offset printing using Japan color standard ink, which is the mainstream of printing, uses yellow, red, indigo, and black ink process four-color (CMYK) inks. Therefore, in order to perform lithographic offset printing, data submitted as “RGB” must be color-converted (color separation) into “CMYK”. In the lithographic offset printed material using process four-color ink, the hue is expressed by subtractive color mixing, so the hue becomes cloudy each time the color is overlaid, and the color reproduction area is necessarily narrower than that of “RGB”. . Further, depending on the selection of the standard for the “RGB” color space at the shooting stage, or depending on the color conversion method from “RGB” to “CMYK”, color reproduction may not be successful. Thus, the difference in color reproducibility between “RGB” digital data and printed matter using process four-color (CMYK) ink is a problem.

  In general, in order to widen the color reproduction region, it is necessary to approximate the ideal spectral reflectance curve of each color.

  That is, the wavelength range in which a person recognizes color is 400 nm to 700 nm light (this wavelength is referred to as visible light). In yellow ink, the reflectance in the wavelength range of 500 nm to 700 nm is 100%, and the wavelength range of 400 nm to 500 nm. The red ink has a reflectance of 0%, and the red ink has a reflectance of 100% in the wavelength region of 400 nm to 500 nm and 600 nm to 700 nm, and a reflectance of 0% in the wavelength region of 500 nm to 600 nm. Therefore, it is said that it is ideal that the reflectance in the wavelength region of 400 nm to 600 nm is 100% and the reflectance in the wavelength region of 600 nm to 700 nm is 0% (the spectral reflectance of the ideal process ink) Curves are shown in Table 17).

However, the reflection spectrum of the ink composition for offset printing of yellow, red, indigo, and black, which is currently used in four process colors, is far from the ideal reflection spectrum. Since there is unnecessary absorption in the part that must be completely reflected, a turbid component of the ink exists, and the color reproducibility is narrowed.

  Especially in the purple (blue violet, RGB “B”) area expressed by two colors of red and indigo inks, both red and indigo inks have many unnecessary absorption components, so there are two colors. The saturation and brightness are inferior to the case where the hue obtained by multiplying the colors is expressed by the ink of the purple pigment alone. For this reason, it has been difficult to reproduce the “B” area of the “RGB” submission data using process four-color (YMCK) ink.

  In particular, if yellow ink printed as the final color is generally opaque, yellow fogging occurs, which has a large effect on each color of the underprint, which also reproduces the RGB submission data. It is difficult. Accordingly, it is desirable that the yellow ink is as transparent as possible, and can produce a secondary color and a tertiary color with no turbidity when printed with other colors.

  As means for solving these problems, Patent Document 1 discloses a printing method using an ink set of 5 to 7 colors as a printing method for obtaining a printed matter with high saturation. In this printing method, as an ink set, an ink set consisting of 6 colors (hexachrome printing) with orange and green added to the process 4 colors, and 7 colors (high-fidelity printing with orange, green and purple added to the process 4 colors) An ink set made up of or the like is used.

In hexachrome printing, not only primary colors but also secondary and tertiary colors can be prevented from becoming cloudy and the color reproduction area can be expanded by adding fluorescent pigments to some color inks. It has been. However, when this method is used, the printability is deteriorated (transfer failure, gloss reduction, etc.) and the printed matter is faded due to insufficient light resistance.
In high-fidelity printing, in order to compensate for the three hues of orange, green, and purple that cannot be reproduced with the conventional four colors of processes, a total of seven color printing methods are used in which these three colors of ink are added. However, these methods require an expensive multicolor printing machine in which the number of ink colors used is 6 or 7 and the number of cylinders of the printing machine is 6 or more, and more than 6 plates or more. Requires a color-separated version. Therefore, in order to newly start these methods, a large amount of capital investment, advanced color separation technology, complicated color tone management (print density, management of registration accuracy), etc. are required. The use is stopped.

In Non-Patent Documents 1 to 3, a method of printing at a higher print density than the conventional one is examined for the purpose of expanding the color reproduction region. By printing at a high density, it is possible to obtain a voluminous and sharp feeling like a photograph even in a lithographic printing product. Hue changes occur at an early stage. In particular, red pigments used in conventional inks contain a slightly yellowish component, and indigo pigments contain a slightly reddish component. The hue changes to reddish.
JP 2001-260516 A Yasuhiro Kinoshita: International Printing University Research Report [5], 2-6 (2005) Yasuhiro Kinoshita: Noma Prize Award Lecture, 12-21 (2003) Yoshiyuki Hashizume: Printed magazine, 79 [9], 15-18 (1996)

  The present invention has been made to solve any of the problems in the conventional technology. That is, the object of the present invention is to add purple ink to a printing method using four process inks that can widen the color rendering area (gamut) than when printing ISO standard Japan color standard ink. It is to provide a printing method that can reproduce a color region that is closer to the color reproduction region of “RGB” by printing with five color inks than a printed product using Japan color standard ink. . Still another object of the present invention is to provide an ink set and ink that can be preferably used in these printing methods, and to provide a printed matter printed by these printing methods.

  In a lithographic printing method using an ink selected from yellow, red, indigo and black ink, yellow, red, indigo, yellow ink contains a disazo yellow compound as a coloring component, and red ink is colored Containing a metal lake compound of rhodamine-based dye as a component, and indigo ink comprising a combination of lithographic inks characterized by containing a phthalocyanine-based compound as a coloring component. Lithographic printing using an ink selected from five color inks in combination with an ink containing a pigment having a purple hue typified by methyl violet lake compound, dioxazine violet compound, or naphthol violet compound It is about the method.

  In the present invention, CI pigment yellow 12 or CI pigment yellow 13 is contained as a disazo yellow compound in an amount of 5 to 15% by weight based on the total weight of the ink, and is applied to black ink having a density value of 1.85 to 1.90. The present invention relates to the above lithographic printing method using a yellow ink having an L * value of 17 or less when overprinted in a density range of 1.40 to 2.10.

  Further, the present invention uses a red ink containing CI Pigment Red 81, CI Pigment Violet 1 or CI Pigment Red 169 in an amount of 15 to 30% by weight based on the total weight of the ink as a metal lake compound of a rhodamine dye. The present invention relates to the lithographic printing method described above.

  The present invention also relates to the lithographic printing method as described above, wherein the indigo ink containing 10 to 25% by weight of CI pigment blue 15: 3 or CI pigment blue 15: 4 based on the total weight of the ink is used as the phthalocyanine compound. Is.

Furthermore, the present invention relates to indigo ink wherein the specific surface area of CI Pigment Blue 15: 3 or CI Pigment Blue 15: 4 described above is 74 m 2 / g or more.
Furthermore, CI. Pigment Green 7 or CI. The present invention relates to the above-described indigo ink containing Pigment Green 36 in an amount of 0.5 to 2.0% by weight based on the total weight of the ink.

  Further, the present invention contains CI Pigment Violet 3, CI Pigment Violet 3: 1, CI Pigment Violet 3: 3, and CI Pigment Violet 27 as methyl violet lake compounds in an amount of 10 to 30% by weight based on the total weight of the ink. The present invention relates to the above-described planographic printing method using purple ink.

  The present invention also relates to the lithographic printing method as described above, wherein purple ink containing 10 to 30% by weight of CI pigment violet 23 and CI pigment violet 37 is used as the dioxazine violet compound. is there.

  The present invention also relates to the lithographic printing method as described above, wherein a purple ink containing 10 to 30% by weight of CI pigment violet 25 and CI pigment violet 50 based on the total weight of the ink is used as the naphthol violet compound. .

  The present invention also relates to the lithographic printing method described above, wherein the reflectance of (a) yellow, (b) red, and (c) indigo is as follows.

(A) In the wavelength region of 400 nm to 700 nm, when the maximum reflectance is 100%, the wavelength region of 400 nm to 480 nm is 1 to 20%, and the reflectance in the wavelength region of 540 nm to 700 nm is 90 to 100%. A yellow ink containing 5 to 15% by weight of a coloring component having a reflection spectrum based on the total weight of the ink.

(B) In the wavelength region of 400 nm to 700 nm, when the maximum reflectance is 100%, the maximum reflectance in the wavelength region of 400 nm to 500 nm is 50% to 100%, 500 nm.
The reflectance in the wavelength region of ˜560 nm is 1 to 20%, and the reflectance of 640 nm to 700 nm is 9%.
A red ink containing 15 to 30% by weight, based on the total weight of the ink, of a coloring component having a reflection spectrum of 0% to 100%.

  (C) In the wavelength region of 400 nm to 700 nm, when the maximum reflectance is 100%, the reflectance of the wavelength region of 420 nm to 530 nm is 50 to 100%, and the reflectance of 600 nm to 700 nm is 1 to 20%. An indigo ink containing 10 to 25% by weight of a coloring component having a spectrum based on the total weight of the ink.

  Furthermore, the present invention relates to an ink set used for the lithographic printing method described above.

  Furthermore, the present invention relates to a printed matter printed using the lithographic printing method described above.

  By using the lithographic ink composition provided by the present invention, conventionally, in addition to the Japanese color standard ink yellow, red, indigo and black ink process, 6 colors and 7 colors printing are added, such as orange, green, purple, etc. The color reproduction area of RGB expressed in (4) can be made as close as possible with four colors of yellow, red, indigo, and black and purple, which have a wider color rendering area than Japan color standard ink.

  Further, in the present invention, since a fluorescent pigment is not used as a means for improving the color reproduction region of the printed material, a highly saturated printed material can be obtained without deteriorating printability, fading with time of the printed material, and the like.

  Next, the present invention will be described more specifically with reference to preferred embodiments.

The present invention comprises a pigment, a vehicle component obtained by heating and dissolving a synthetic resin, a vegetable oil, and a petroleum solvent together with a gelling agent such as aluminum stearate and aluminum chelate as necessary, and an auxiliary agent such as an antifriction agent. A lithographic ink comprising five colors of yellow, red, indigo, black, and purple is used, and the ink of the present invention can be produced by a conventionally known method.

  The ink used in the present invention is printed on ISO standard Japan color standard paper, for example, “Tokuhishi art double sided paper size / 110 kg” manufactured by Mitsubishi Paper Co., Ltd., and each color of yellow, red, indigo and black is Gretag Macbeth Concentration value when measured with a company-made SpectroEye (light source D50, 2 degree field of view, measuring optics 45 ° / 0 °, density group DIN16536, no polarizing filter, absolute blank standard), yellow is 1.30 to 2.00 When solid printing is performed independently in the range of 1.40 to 2.00 for red, 1.40 to 2.05 for indigo, and 1.60 to 2.05 for black, SpectroEye made by Gretag Macbeth (light source) L * a * b * value measured with D50, 2-degree field of view, measuring optics 45 ° / 0 °, no polarizing filter, absolute blank paper standard) is yellow ink, L *: 87-95, preferably 88- 93, a *: −4 to −12, preferably −5 to −10, b *: 90 to 110, red ink, L *: 47 to 5, preferably 48 to 54, a *: 75 to 83, preferably 76 to 82, b *: -14 to -20, preferably -15 to -19, indigo ink, L *: 50 to 58, preferably Is 51 to 57, a *: −40 to −46, preferably −41 to −44, b *: −45 to −53, preferably −46 to −52, black ink, L *: 7 to 15, Preferably it is in the range of 8 to 15, a *: -1.5 to 1.5, preferably -1 to 1, b *: -1.5 to 1.5, preferably -1 to 1. Features.

In addition, L * a * b * value of each color when two types selected from yellow, red and indigo ink are overprinted, and L when three colors of yellow, red and indigo ink are overprinted * a * b * values are L *: 49-56, a *: 63-70, b *: 52-68, red ink x yellow ink, L *: indigo ink x yellow ink, L *: 45 to 53, a *: -74 to -84, b *: 23 to 33, indigo ink x red ink, L *: 19 to 31, a *: 25 to 40, b *:- 60 to -70, and solid overprint of indigo ink x red ink x yellow ink L *: 17 to 27, preferably 18 to 26, a *: -3 to -14, preferably -4 ~ -11, b *: -5 to 5, preferably -3 to 3.
In addition, the purple ink generally has no standard density value, but in the present invention, the density value measured with a SpectroEye densitometer manufactured by Gretag Macbeth is 1.40 to 2.20 as the indigo density. The L * a * b * value of the monochromatic solid part when it is in the range of L *: 9-40, preferably 10-36, a *: 40-80, preferably 45-76, more preferably 46- 73, b *: −50 to −80, preferably −55 to −80.

  Next, Japan Color is a standard color for printing established by the ISO / TC130 National Committee. In Japan Color Reproduction Printing 2001, colorimetric values (L * a * b * values) of ISO12642 patterns (928 colors, also referred to as IT8) are shown as data. As printing conditions for reproducing this Japan color reproduction reproduction 2001, standard conditions of the international standard ISO12647-2 regarding commercial offset printing are used. As ink and printing paper, ink and printing paper that are normally used in Japan are used (four kinds of paper are determined in Japan Color 2001).

  The solid standard colorimetric value established by Japan Color is precisely “JAPAN COLOR SOLID VALUE”, which represents a solid color standard. This is a measure of solid patch colorimetric values for measuring the internal standard density of 21 representative printing companies in cooperation with the Japan Printing Industry Federation. Paper is used by each printing company. The art paper used is used. This average measured value (CIELAB value) is obtained, and the value is considered as the average solid color of Japanese printed matter. The sample printed using Japan Color Standard Ink and Japan Color Standard Paper has a color difference ( A colorimetric value that minimizes ΔE) is determined as JAPAN COLOR SOLID VALUE, which is a colorimetric value for eight colors of yellow, red, indigo, black, blue, green, red, and white (blank). Is decided. At present, the third edition of “Japan Color 2000 Solid Color Standard Colorimetric Value”, which was revised in 2000, is standard, and the yellow values are L *: 87.9 and a *: −7. 5, b *: 91.5, red is L *: 46, 6, a *: 75.1, b *: -4.4, indigo is L *: 53.9, a *: -37. 0, b *: -50.1, black is L *: 13.2, a *: 1.3, b *: 1.9, blue is L *: 21.0, a *: 20.0 , B *: −51.0, green is L *: 49.0, a *: −73.5, b *: 25.0, red is L *: 46.5, a *: 68.5 , B *: 48.0, white is defined as L *: 93.0, a *: 0.5, b *: 0.4. The measurement conditions are based on the light source D50, 2-degree field of view, measurement optics 45 ° / 0 °, black baking (ISO 13655), and the ΔE value is determined to be 6 or less as the allowable color difference range.

  In the present invention, the art paper to be used is “Japanese special color double-sided paper / 110 kg” manufactured by Mitsubishi Paper Industries, Ltd., which is a Japan color standard paper of the ISO standard, and color measurement is performed.

  General Japan color standard ink (for example, “Toyo Ink Manufacturing Co., Ltd.“ TK High Unity each color ”) and Japan color standard paper (for example,“ Mr. The L * a * b * values of the monochrome solid portions of yellow, red, indigo, and black when printed on and the C value calculated from them are L *: 86, a *: −7, b *: 92, C: about 92, for red ink, L *: 45, a *: 72, b *: -5, C: about 72, for indigo ink, L *: 54, a * : -36, b *: -49, C: about 61, and for black ink, L *: 15.0, a *: 1.5, b *: 2.0, C: about 2.5 is there.

  The Japan color standard paper is a Japanese standard paper determined as follows. First, the average optical characteristic value of art paper surfaces of six domestic paper manufacturers was defined as “standard characteristic value of Japan Paper”. Two companies' art papers having characteristics close to the standard characteristic values were defined as Japan color standard paper. Currently, Japan Color Standard Paper has the following optical properties: whiteness: 80 ± 5 (%), glossiness: 75 ± 2 (%), L *: 93.0 ± 3, a *: 0.5 ± 2, b *: 0.4 ± 2. The Japan color standard paper is equivalent to ISO standard paper type 1 which defines offset printing process management.

  “Japan Color Reproduction Printing 2001” uses four types of paper, art paper, coated paper, matte coated paper, and high-quality paper, which are domestic ISO standard products. Examples of the art paper include “OK Kanfuji N” manufactured by Oji Paper Co., Ltd., “NPI Special Art” manufactured by Nippon Paper Industries Co., Ltd., and “Tokuhishi Art Both Sides N” manufactured by Mitsubishi Paper Industries Co., Ltd. Examples of the coated paper include Oji Paper Co., Ltd. “OK Top Coat N”, Nippon Paper Industries Co., Ltd. “NPI Coat”, and Mitsubishi Paper Industries Co., Ltd. “Pearl Coat”. Examples of the mat coated paper include “OK Top Coat Mat” manufactured by Oji Paper Co., Ltd., “Ulite” manufactured by Nippon Paper Industries Co., Ltd., and “New V Mat” manufactured by Mitsubishi Paper Industries Co., Ltd. Examples of the quality paper include “OK Prince Quality” manufactured by Oji Paper Co., Ltd., “New NPO Quality” manufactured by Nippon Paper Industries Co., Ltd., and “Kinryo” manufactured by Mitsubishi Paper Industries Co., Ltd.

  In the present invention, when evaluating ink characteristics such as density and L * a * b * value, ISO standard Japan color standard paper (for example, “Special” manufactured by Mitsubishi Paper Industries Co., Ltd.) is used as paper for printing ink. Rhizo Art Double Sided 46th Edition / 110 kg ") can be used. In addition, the paper used when actually performing lithographic printing using the method of the present invention or the ink set of the present invention is not limited to Japan color standard paper. Any paper such as the above-mentioned art paper, coated paper, matte coated paper, and high-quality paper can be used. Art paper is preferable.

  In the present invention, “density value” refers to ISO standard Japan color standard paper (for example, “Special Rhibo Art Double Sided Plates / 110 kg” manufactured by Mitsubishi Paper Industries Co., Ltd.), yellow, red, indigo and black ink. Are solid prints, and each density of yellow, red, indigo and black is measured by Gretag Macbeth SpectroEye (manufactured by Gretag Macbeth).

  As a method for expressing the color reproduction area, an XYZ color system (CIE 1931 color system), an X10Y10Z10 color system (CIE 1964 color system), an L * a * b * color system (CIE 1976), a Hunter Lab color system, Munsell color system, L * u * v * color system (CIE1976), and the like.

  In the L * a * b * color system, “lightness” is expressed in L * as the degree of brightness that can be compared regardless of hue, and indicates that the color becomes brighter as L * increases and becomes darker as it decreases. . In addition, “hue” that differs for each color is indicated by a * and b * values, a * indicates red (+) to green (−) direction, and b * indicates yellow (+) to blue (−) direction, In each direction, the color becomes brighter as the absolute value increases, and the color becomes dull as it approaches 0. This makes it possible to digitize one color using L *, a *, and b *. When L *, a *, and b * approach 0 as much as possible, the color becomes neutral and dark, that is, ideal black. In addition to “lightness” and “hue”, there is “saturation (C)” as a method for digitizing the degree of vividness, which can be obtained by the following calculation formula.

Cに関しても同様に、絶対値が大きくなるに従って色鮮やかになり、値が小さくなるにつれてくすんだ色になることを示している。
更に、L*a*b*表色系で表された個々の色が持つ数値を利用して、微妙な色の違い（色差）も数値で表すことが可能になる。２つの色の色差（「△Ｅ」と表現）は、以下の計算式にて求めることができる。

Similarly, C shows that the color becomes brighter as the absolute value increases, and the color becomes dull as the value decreases.
Furthermore, subtle color differences (color differences) can be expressed numerically using numerical values of individual colors expressed in the L * a * b * color system. The color difference (expressed as “ΔE”) between the two colors can be obtained by the following calculation formula.

△Ｅの絶対値が小さいほど２つの色が近似しており、△Ｅの絶対値が大きいほど２つの色が異なっている。

As the absolute value of ΔE is smaller, the two colors are closer to each other, and as the absolute value of ΔE is larger, the two colors are different.

  In order to obtain a color rendering area (gamut) using the L * a * b * color system, first, a color chart such as ISO 12642 chart (IT8 chart) using yellow, red, indigo, black and other inks. Is printed, and the L * a * b * value of each color of the chart (928 color in the case of ISO12642 chart) is measured using a spectrophotometer (Spectro Lino manufactured by Gretag Macbeth) (measuring condition: light source D50, 2-degree field of view) , Measurement optics 45 ° / 0 °, absolute blank paper conditions), and an ICC profile is created from the measurement result using ProfiLeMaker of GretagMacbeth. As the paper on which the ink is printed, ISO standard Japan color standard paper (for example, “Tokuhishi Art Double Sided 46th Edition / 110 kg” manufactured by Mitsubishi Paper Industries Co., Ltd.) can be used.

  Next, using the ICC profile created, Adobe's Photoshop displays the color reproducible area of the RGB image on the screen, or 3D gamut diagram (L * a * b) using CHROMIX CoLorThink. * Color system) can be created.

All color reproduction areas that can be expressed in a single printed matter (including color spaces other than printed matter) are called color rendering regions (gamut). The simplest way to represent gamut is to use a * as the horizontal axis and b * vertical axis. In the two-dimensional space, the solid color part (yellow, red, indigo) and the solid color overprinting part (yellow x red, red x indigo, indigo x yellow) total of a * vs. b * values, It can be expressed by the plotted hexagonal area. The larger the gamut area, the wider the color reproduction area.

  As a printing method used in the present invention, a conventionally known lithographic printing method is used. Examples include offset sheet-fed printing, offset rotary printing, waterless offset printing, and dry offset printing.

  As the ink set used in the present invention, a conventionally known lithographic printing ink is used. For example, an oxidation polymerization type ink, a heat set type ink, a penetrating dry type ink and the like can be mentioned.

  A conventionally known plate making technique is also used for the plate used for printing. Examples thereof include a plate formed by an amplitude modulation screening (AM screening) method, a plate formed by a frequency modulation screening (FM screening) method, and the like.

Regarding the yellow ink used in the present invention, the L * value when overprinted in the density range of 1.40 to 2.10 on the black ink printed within the density value range of 1.85 to 1.90 is If the transparency does not exceed 17, there is little influence on the underprinting ink when the secondary and tertiary colors are overprinted, and a good color reproduction region can be obtained. Further, CI Pigment Yellow 83 can be used as a complementary color by adding 0.5 to 10% by weight, preferably 2 to 5% by weight, based on the total weight of the yellow pigment.

  As the yellow pigment used in the present invention, C.I. Pigment Yellow 12 or C.I Pigment Yellow 13 is preferably used in an amount of 5 to 15% by weight based on the total weight of the ink.

  Examples of the red pigment used in the present invention include, but are not limited to, rhodamine dyes such as rhodamine B, rhodamine 3G and rhodamine 6G, molybdenum, tungsten metal lake compounds, copper iron complex lake compounds, and the like. . CI Pigment Red 81, CI Pigment Red 81: 1, CI Pigment Red 81: 2, CI Pigment Red 81: 3, CI Pigment Red 81: 4, CI Pigment Violet 1 or CI Pigment Red 169 to the total weight of the ink The content is preferably 15 to 30% by weight. These may be used alone or in combination of two or more.

The copper phthalocyanine compound, which is a cyan pigment used in the present invention, is a substance exhibiting a crystal polymorphism (homogeneous heterocrystal), and α, β, γ, ε, π, τ, ρ, χ depending on the crystal structure. is classified into such R-type, crystalline stability, it is preferred to use the β-type dispersion is excellent, even a specific surface area of 74m ² / g~100m ² / g fine β form copper phthalocyanine It is preferable that If it is less than 74 m ² / g, good color reproduction cannot be achieved. On the other hand, if it exceeds 100 m ² / g, the pigment tends to aggregate and dispersibility becomes difficult.

  In the present invention, the halogenated copper phthalocyanine compound in which the hydrogen atom on the benzene ring of the phthalocyanine molecule is substituted with a halogen compound as a complementary color with respect to the total weight of the copper phthalocyanine compound is preferably 5 to 15% by weight, more preferably 8 to 11% by weight. % Can be used, and this makes it possible to widen the color reproduction area of green and purple when overprinted with yellow and red ink without impairing the color reproduction area of indigo ink single color. .

  Specifically, CI Pigment Blue 15: 3 or CI Pigment Blue 15: 4 is preferably contained in an amount of 10 to 25% by weight based on the total weight of the ink, and CI Pigment Green 7 or CI, Pigment is used as a complementary color. It is also possible to use the green 36 by adding 0.5 to 2.0% by weight based on the total weight of the ink.

  Examples of the green pigment used in the present invention include halogenated phthalocyanine compounds. The most commonly used is chlorinated copper phthalocyanine, and others include bromine instead of chlorine, chlorine and bromine, and copper-free metal-free phthalocyanine blue. . These may be used alone or in combination of two or more.

  Examples of the purple pigment used in the present invention include CI pigment violet 2, CI pigment violet 2: 2, CI pigment violet 3, CI pigment violet 3: 1, CI pigment violet 3: 3, CI pigment violet 5, and CI pigment. Violet 5: 1, CI Pigment Violet 19, CI Pigment Violet 23, CI Pigment Violet 25, CI Pigment Violet 27, CI Pigment Violet 32, CI Pigment Violet 37, CI Pigment Violet 39, CI Pigment Violet 50, etc. It is preferable to contain 10 to 30% by weight, preferably 12 to 27% by weight, and more preferably 14 to 25% by weight with respect to the total weight. These may be used alone or in combination of two or more.

  In the present invention, cyan pigments such as CI pigment blue 15: 3 and CI pigment blue 15: 4 are added as complementary colors to the above-described purple pigment within a range of 1 to 10% by weight based on the total weight of the ink. It is also possible to use it.

  As a black pigment, carbon black such as C.I. I. Pigment black 7 and the like. The characteristics of carbon black include physicochemical properties such as particle diameter, nitrogen adsorption specific surface area, coloring power, DBP oil absorption, volatile matter, pH value, PVC blackness, etc. Carbon black having a larger nitrogen adsorption specific surface area, that is, a smaller particle diameter and smaller DBP oil absorption, is said to obtain a higher concentration and higher gloss ink. Conversely, carbon with a large particle size and large DBP oil absorption can reproduce a high printing density on low-quality paper and newsprint with low surface smoothness, but with coated paper such as art paper and coated paper, Deterioration is remarkable.

The carbon black used in the conventional lithographic printing ink (excluding ink for lower paper), nitrogen adsorption specific surface area of 80 m ² / g or more, about 30nm or less in particle diameter, DBP oil absorption following 100 cm ^3/100 g carbon Is used.

  Examples of the carbon black used in the present invention include C.I. I. Pigment Black 7 is preferably contained in an amount of 10 to 30% by weight, preferably 15 to 25% by weight, more preferably 16 to 20% by weight, based on the total weight of the ink. When the content exceeds 30% by weight, dispersibility and fluidity are remarkably deteriorated, and when it is 10% by weight or less, a sufficient density for printing cannot be obtained.

  In the present invention, as a method for producing blackness of the black ink, 4 to 10% by weight of an alkali blue lake compound is contained as a complementary color to the combination of the carbon blacks with respect to the total weight of the ink. Examples of alkaline blue lake compounds include C.I. I. Pigment blue 18, C.I. I. Pigment blue 19, C.I. I. Pigment blue 56, C.I. I. Pigment blue 57, C.I. I. Pigment blue 61 etc. are mentioned, These may be used independently and can also be used in combination of 2 or more types. If it is 4% by weight or less, sufficient blackness cannot be obtained, and if it exceeds 10% by weight, the hue becomes blue and the color tone is not sufficient as a black color.

  In addition, the coloring components (dyes and pigments) exemplified in the present invention may be used alone or in combination with two or more inks.

Examples of the synthetic resin used in the present invention include rosin-modified phenol resin, petroleum resin, alkyd resin, rosin-modified alkyd resin, petroleum resin-modified alkyd resin, and rosin ester. Preferably, a rosin modified phenolic resin is used. The rosin-modified phenol resin is not particularly limited, but it is preferable to use a resin having a weight average molecular weight of 10,000 to 300,000. When the molecular weight is 10,000 or less, the viscoelasticity of the ink is lowered, and when it is 400,000 or more, the fluidity as the ink becomes insufficient.

  Examples of vegetable oils include those derived from vegetable oils such as coconut oil, cottonseed oil, peanut oil, palm oil, corn oil, olive oil, linseed oil, soybean oil, safflower oil, tung oil, and their thermal polymerized oil and oxygen. Blow polymerization oil can also be used. Moreover, in this invention, these vegetable oils may be used independently and can also be used in combination of 2 or more type.

The petroleum solvent used in the ink has an aromatic hydrocarbon content of 1% or less, an aniline point of 75 to 95 ° C, preferably 80 to 95 ° C, and a boiling point of 260 to 350 ° C, preferably 280 to 350. It is a petroleum solvent in the range of ° C. If the aniline point is below 75 ° C,
Since the ability to dissolve the resin is too high, the setting property of the ink becomes slow, which is not preferable.
When the temperature exceeds 5 ° C., the resin is poorly soluble, so that the gloss and the inking are deteriorated.
When the boiling point is less than 260 ° C., the evaporation of the ink solvent on the printing press increases, and the transferability of the ink to a roller, a blanket, a plate, or the like deteriorates due to the deterioration of the fluidity of the ink. Moreover, when it exceeds 350 degreeC, since drying of heat set type ink is inferior, it is unpreferable.

Further, the lithographic ink composition of the present invention includes a gelling agent, a pigment dispersant, a metal dryer, a drying inhibitor, an antioxidant, an anti-friction agent, an anti-set-off agent, and a nonionic surfactant as required. Additives such as agents and polyhydric alcohols can be used as appropriate.

EXAMPLES Next, although an Example demonstrates this invention further in detail, the scope of the present invention is not limited to these description Example. In addition, the part of the following description represents a weight part and% represents weight%.

(Example of production of rosin-modified phenolic resin)
P-octylphenol 1000 parts, 35% formalin 850 parts, 93% sodium hydroxide 60 parts and toluene 1000 parts were added to a four-necked flask equipped with a stirrer, cooler and thermometer, and reacted at 90 ° C. for 6 hours. It was. Then, 125 parts of 6N hydrochloric acid and 1000 parts of tap water were added, stirred and allowed to stand, and the upper layer part was taken out to obtain 2000 parts of a toluene solution of a resole type phenol resin having a nonvolatile content of 49%. It was.

  A four-necked flask equipped with a stirrer, a condenser with a water separator, and a thermometer was charged with 1000 parts of gum rosin, dissolved at 200 ° C. while blowing nitrogen gas, and 1800 parts of the resole solution produced above was added. After reacting at 230 ° C. for 4 hours while removing toluene, 110 parts of glycerin was added and reacted at 250 ° C. for 10 hours to give an acid value of 20 or less, a weight average molecular weight of 50000, Shin Nippon Petrochemical Co., Ltd., AF Solvent 6 A rosin-modified phenol resin having a cloudiness temperature of 88 ° C. was obtained.

(Example of varnish production)
190 parts of rosin modified phenolic resin 42 parts, soybean oil 33 parts, AF solvent 6 (Shin Nippon Petrochemical Co., Ltd. solvent) 24 parts, ALCH (Kawaken Fine Chemical Co., Ltd. gelling agent) 1.0 part And stirred for 1 hour to obtain a varnish.

(Ink Example) (Yellow ink)
In the formulation shown in Table 1, C.I. I. Pigment Yellow 12 (LI made by Toyo Ink Manufacturing Co., Ltd.)
ONOL YELLOW 1235-P) was subjected to primary dehydration by gradually adding 60 parts of varnish and kneading in a kneader at a temperature of 75 ° C. Next, vacuum dehydration was performed for 1 hour under conditions of a kneader temperature of 100 ° C. to 120 ° C. and a degree of vacuum of 76 mmHg, and secondary dehydration was performed so that the water content in the base ink was 0.5% or less. After dehydration, the remaining varnish and petroleum solvent were added, kneaded and diluted, and the undispersed base ink was taken out from the kneader. The extracted base ink is kneaded with a three roll with a roll temperature of 60 ° C. until the particle size of the pigment becomes 7.5 microns or less with a dispersion particle system measuring machine (grind meter). Obtained. Next, varnish, soybean oil, tung oil, petroleum solvent, compound, metal dryer, and drying inhibitor were added to the base ink 1 according to the formulation shown in Table 2 to obtain yellow ink 1.

(Ink Example) (Red ink)
C. in the formulation of Table 1. I. Pigment Red 81 (109N Fast Pink, manufactured by Inagawa River Co., Ltd.) is mixed with varnish and petroleum solvent, and the mixture is milled until the particle size of the pigment becomes 7.5 microns or less with a dispersion particle measuring machine (grind meter). Crimson base ink 2 was obtained. Next, soybean ink, tung oil, petroleum-based solvent, compound, metal dryer, and drying inhibitor were added to the base ink 2 according to the formulation shown in Table 2 to obtain red ink 2.

(Ink Example) (Red ink)
C. in the formulation of Table 1. I. Pigment Red 169 (Fanal Pink D4810 manufactured by BASF) is mixed with varnish and petroleum solvent, and the base ink of kneaded meat and red is used until the particle size of the pigment becomes 7.5 microns or less with a dispersion particle measuring machine (grind meter). 3 was obtained. Next, soybean oil, tung oil, petroleum-based solvent, compound, metal dryer, and drying inhibitor were added to the base ink 3 according to the formulation shown in Table 2 to obtain red ink 3.

(Ink Example) (Red ink)
Crimson base ink 2 and crimson base ink 3 were mixed in the formulation shown in Table 2, and then soybean oil, tung oil, petroleum solvent, compound, metal dryer, and drying inhibitor were added to obtain crimson ink 4.

(Example of ink) (Indigo ink)
In the formulation of Table 1, C.I. I. Pigment Blue 15: 3 (LIO manufactured by Toyo Ink Manufacturing Co., Ltd.)
NOL BLUE GLA-SD: specific surface area of 74.625 m2 / g) is mixed with varnish and petroleum solvent, and the mixture is kneaded until the particle size of the pigment becomes 7.5 microns or less with a dispersion particle measuring machine (grind meter). An indigo base ink 4 was obtained. Next, soybean oil, tung oil, petroleum-based solvent, compound, metal dryer, and drying inhibitor were added to the base ink 4 in the formulation shown in Table 2 to obtain indigo ink 5.

(Example of ink) (Indigo ink)
C. in the formulation of Table 1. I. Pigment Green 7 (LIONOL GREEN YS2A manufactured by Toyo Ink Mfg. Co., Ltd.) is mixed with varnish and petroleum solvent, and the mixture is kneaded until the pigment particle size becomes 7.5 microns or less with a dispersion particle measuring machine (grind meter). After mixing Indigo Base Ink 4 and Base Ink 5 with the formulation shown in Table 2, soybean oil, tung oil, petroleum-based solvent, compound, metal dryer, and drying inhibitor were added. 6 was obtained.

(Ink Example) (Black ink)
C. in the formulation of Table 1. I. Pigment Black 7 (Mitsubishi Chemical Co., Ltd. Mitsubishi Carbon MA11) is mixed with varnish and petroleum solvent, and the mixture is ground until the particle size of the pigment is 7.5 microns or less with a dispersion particle measuring machine (grind meter). A black base ink 6 was obtained.
Next, alkali blue toner (Morimura Chemical Co., Ltd. MT-15N compound: CI Pigment Blue 61 38.5% by weight), soybean oil, tung oil with the composition of Table 2 for this base ink 6 Then, a petroleum solvent, a compound, a metal dryer, and a drying inhibitor were added to obtain black ink 7.

(Ink Example) (Purple ink)
In the formulation of Table 1, C.I. I. Pigment Violet 3 (7805 First Violet, manufactured by Dainichi Seika Kogyo Co., Ltd.) is mixed with varnish and petroleum solvent, and kneaded until the particle size of the pigment is 7.5 microns or less using a dispersion particle measuring machine (grind meter). Meat, purple base ink 7 was obtained. Next, soybean oil, tung oil, petroleum-based solvent, compound, metal dryer, and drying inhibitor were added to this base ink 7 in the formulation shown in Table 2 to obtain purple ink 8.

(Ink Example) (Purple ink)
In the formulation of Table 1, C.I. I. Pigment Violet 3: 3 (No. 106 Violet Lake, manufactured by Dainichi Seika Kogyo Co., Ltd.) is mixed with varnish and petroleum solvent, and the particle size of the pigment is 7.5 microns or less with a dispersed particle measuring machine (grind meter). Until then, the paste and purple base ink 8 were obtained. Then, to this base ink 8, purple oil 9 was obtained by adding soybean oil, tung oil, petroleum-based solvent, compound, metal dryer, and drying inhibitor in the composition shown in Table 2.

(Ink Example) (Purple ink)
In the formulation of Table 1, C.I. I. Pigment Violet 23 (LIONOGEN VIOLET R6200 manufactured by Toyo Ink Mfg. Co., Ltd.) is mixed with varnish and petroleum solvent, and the mixture is kneaded until the particle size of the pigment becomes 7.5 microns or less with a dispersion particle measuring machine (grind meter). A purple base ink 9 was obtained. Next, purple oil 10 was obtained by adding tung oil, petroleum solvent, compound, metal dryer, and drying inhibitor to the base ink 9 according to the formulation shown in Table 2.

(Ink Example) (Purple ink)
In the formulation of Table 1, C.I. I. Pigment Violet 50 (FAST VIOLET B CONC manufactured by Toyo Ink Mfg. Co., Ltd.) is mixed with varnish and petroleum solvent, and kneaded until the particle size of the pigment is 7.5 microns or less with a dispersion particle measuring machine (grind meter). Meat, purple base ink 10 was obtained. Then, to this base ink 10, purple oil 11 was obtained by adding soybean oil, tung oil, petroleum-based solvent, compound, metal dryer, and drying inhibitor in the composition shown in Table 2.

(Ink Example) (Purple ink)
Violet base ink 7 and purple base ink 8 and indigo base ink 4 are mixed in the composition shown in Table 2, and soybean oil, tung oil, petroleum solvent, compound, metal dryer, drying inhibitor is added, and purple ink 12 Got.

(Ink comparison example) (yellow ink)
In the formulation shown in Table 1, C.I. I. Pigment Yellow 12 (LI made by Toyo Ink Manufacturing Co., Ltd.)
ONOL YELLOW 1229-P) was subjected to primary dehydration by gradually adding 60 parts of varnish and kneading in a kneader at a temperature of 75 ° C. Next, vacuum dehydration was performed for 1 hour under conditions of a kneader temperature of 100 ° C. to 120 ° C. and a degree of vacuum of 76 mmHg, and secondary dehydration was performed so that the water content in the base ink was 0.5% or less. After dehydration, the remaining varnish and petroleum solvent were added, kneaded and diluted, and the undispersed base ink was taken out from the kneader. The extracted base ink is kneaded with a three-roll having a roll temperature of 60 ° C. until the particle diameter of the pigment becomes 7.5 microns or less with a dispersion particle measuring machine (grind meter). Obtained. Next, varnish, soybean oil, tung oil, petroleum solvent, compound, metal dryer, and drying inhibitor were added to the base ink 11 in the formulation shown in Table 2 to obtain yellow ink 13.

(Ink comparison example) (Red ink)
As with the yellow ink, C.I. I. Pigment Red 57: 1 (LIONOL RED 6B 4240-P manufactured by Toyo Ink Manufacturing Co., Ltd.) was used to obtain red base ink 12. Next, soybean ink, tung oil, petroleum-based solvent, compound, metal dryer, and drying inhibitor were added to the base ink 12 in the formulation shown in Table 2 to obtain red ink 14.

(Ink comparison example) (Indigo ink)
C. in the formulation of Table 1. Indigo base ink 13 was obtained using I Pigment Blue 15: 3 (LIONOL BLUE FG7330: specific surface area 71.750 m2 / g manufactured by Toyo Ink Manufacturing Co., Ltd.). Next, soybean oil, tung oil, petroleum solvent, compound, metal dryer, and drying inhibitor were added to the base ink 13 according to the formulation shown in Table 2 to obtain indigo ink 15.

(Ink comparison example) (Black ink)
Alkali blue toner (Morimura Chemical Co., Ltd. MT-15N compound: 38.5% by weight of CI Pigment Blue 61), soybean oil, tung oil with black base ink 6 in the composition shown in Table 2 Then, a petroleum solvent, a compound, a metal dryer, and a drying inhibitor were added to obtain black ink 16.

  The transparency of yellow ink was evaluated by the following test method.

  Yellow ink is printed in the density range of 1.40 to 2.10 on black ink (TK high unity ink manufactured by Toyo Ink Co., Ltd.) printed within the density value range of 1.85 to 1.90. , L * was measured. The results are shown in Table 3. The yellow ink of the example does not exceed L * even when the density value is increased to 2.20, hardly affects the black ink of the underprint, and can be said to have excellent transparency (L * has a value) The smaller the color, the more black it is, and the larger the color, the whiter it is). On the other hand, in the comparative example, L * is high, and it can be seen that the black ink of the underprinted black ink is hindered because the yellow ink of the overprinted is opaque.

  In addition, about the specific surface area, the value computed by the following formula | equation from the surface area measured using the flow type specific surface area measuring apparatus "Flowsorb II" by Shimadzu Corporation was defined and described.

Specific surface area (m ² / g) = surface area (m ² ) / powder mass (g)

(Print evaluation test)
The inks of the above examples and comparative examples were evaluated according to the combinations shown in Table 4.

Printing machine: Heidelberg Speedmaster Kikuzen 5-color machine
(Heidelberg Japan Ltd.)
Paper: Tokishi Art Double Sided 110Kg (Mitsubishi Paper Co., Ltd.)
Dampening solution: Astro Mark 3 Plus (Niken Chemical Laboratory Co., Ltd.) 4.0% tap aqueous solution Printing speed: 10,000 sheets / hour Concentration: SpectroEye (manufactured by Gretag Macbeth, light source D50, 2 degrees field of view, measuring optics 45 Measure the density value of the solid part of the printed matter (yellow, red, indigo, black, purple) at ° / 0 °, density standard DIN16536, no polarizing filter, absolutely blank paper standard).

Adjust the solid density so that yellow is 1.40 to 1.44, red is 1.52 to 1.56, indigo is 1.63 to 1.67, and black is 1.85 to 1.90. In addition, the purple ink is printed by adjusting the solid portion so that the indigo density is in the range of 1.40 to 2.20. Colorimetry: SpectroEye (manufactured by Gretag Macbeth, light source D50, 2 degree field of view, measurement optics 45 ° Single color solid part (yellow, red, indigo, black, purple) and single color solid color overprint part (2-color overlap: yellow x red, red) × Indigo, Indigo × Yellow, Crimson × Purple, Indigo × Purple, 3 color overlay: Indigo × Crimson × Yellow, 4 color overlay: Yellow × Red × Indigo × Ink) L *, a *, b * values . The C value was determined from a * and b * by the following formula.

結果を表５〜表７に示す。また、表８〜表９に印刷実施例１〜６及び印刷比較例１のC値の比較をグラフで表した。黄、紅、藍及び２色重ね（黄×紅、紅×藍、藍×黄）については、比較例と比べて実施例のL*値とC値が大きく、印刷物の明度及び彩度が高い。また、墨については、比較例と比べて実施例のL*値が低く、また、C値も０に近いことから墨インキとしての黒色感に優れているといえる。

The results are shown in Tables 5-7. Table 8 to Table 9 are graphs showing the comparison of C values of Printing Examples 1 to 6 and Printing Comparative Example 1. For yellow, crimson, indigo and two-color overlay (yellow x crimson, crimson x indigo, indigo x yellow), the L * value and C value of the example are larger than the comparative example, and the brightness and saturation of the printed matter are high. . For black, the L * value of the example is lower than that of the comparative example, and the C value is close to 0. Therefore, it can be said that black is excellent as black ink.

更に、表１０には印刷実施例７〜１１及び印刷比較例２〜６の紅×紫、及び、藍×紫のC値の比較をグラフで表した。実施例は比較例よりL*値及びC値が高く、紅、藍と紫インキを刷り重ねた時の色の濁りが比較例より少なく彩度が高い。

Further, Table 10 is a graph showing a comparison of C values of Red x Purple and Indigo x Purple of Printing Examples 7 to 11 and Comparative Examples 2 to 6. The examples have higher L * values and C values than the comparative examples, and the color turbidity when the red, indigo and purple inks are overprinted is less than the comparative examples and the chroma is high.

更には、a*を横軸、b*縦軸とした２次元空間に、各a*、b*値をプロットし、２次元のガモットで比較した。（表１１〜表１６）
印刷実施例１〜６及び比較例１のガモット図を表１１に示す。紫インキを入れない黄、紅、藍、墨の４色のインキの組み合わせにおいて、すべての実施例が比較例よりも色再現領域が広い。

Furthermore, each a * and b * value was plotted in a two-dimensional space with a * as the horizontal axis and b * vertical axis, and compared with a two-dimensional gamut. (Table 11 to Table 16)
Table 11 shows gamut diagrams of Printing Examples 1 to 6 and Comparative Example 1. In the combination of four inks of yellow, red, indigo, and black without purple ink, all the examples have a wider color reproduction area than the comparative example.

  Moreover, evaluation of printing examples 7-11 which combined purple ink with the combination of the ink of printing example 4 was implemented, and also the result of printing comparative examples 2-6 which combined purple ink with the combination of comparative example 1 and The color reproduction regions were compared using a two-dimensional gamut diagram (Tables 12 to 16).

印刷実施例７と印刷比較例２の結果を表１２、印刷実施例８と印刷比較例３の結果を表１３、印刷実施例９と印刷比較例４の結果を表１４、印刷実施例１０と印刷比較例５の結果を表１５、印刷実施例１１と印刷比較例６の結果を表１６へそれぞれ示す。また、各ガモット図には、紫インキを加えていない印刷実施例４の結果も比較として加えた。

Table 12 shows the results of printing example 7 and printing comparison example 2, Table 13 shows the results of printing example 8 and printing comparison example 3, Table 14 shows the results of printing example 9 and printing comparison example 4, and printing example 10. The results of Printing Comparative Example 5 are shown in Table 15, and the results of Printing Example 11 and Printing Comparison Example 6 are shown in Table 16, respectively. In addition, in each gamut diagram, the result of Printing Example 4 in which no purple ink was added was also added as a comparison.

  By adding purple ink to four colors of yellow, red, indigo and black, which have a wider color reproduction range than before, the color reproduction range is further expanded. Furthermore, the same result was obtained also in the combination of 5 colors which added the purple ink to the combination of the printing examples 1-3 and the printing examples 5-6.

  In addition, Table 18 shows the obtained spectral reflectance curve. Compared to the conventional ink of the comparative example, the ink of the example is closer to the ideal spectral reflectance curve, and unnecessary absorption of the portion that must be completely reflected is reduced. For this reason, the turbidity component of the ink is reduced and the color reproduction region is widened.

Claims (12)

  In a lithographic printing method using an ink selected from yellow, red, indigo and black ink, yellow, red, indigo, yellow ink contains a disazo yellow compound as a coloring component, and red ink is colored Containing a metal lake compound of a rhodamine-based dye as a component, and the indigo ink comprising a combination of lithographic inks characterized by containing a phthalocyanine-based compound as a coloring component. Lithographic printing using an ink selected from five color inks in combination with an ink containing a pigment having a purple hue typified by methyl violet lake compound, dioxazine violet compound, or naphthol violet compound Method.   As a disazo yellow compound, CI pigment yellow 12 or CI pigment yellow 13 is contained in an amount of 5 to 15% by weight based on the total weight of the ink, and the density is 1.40 to 1.40 on the black ink having a density value of 1.85 to 1.90. 2. The lithographic printing method according to claim 1, wherein a yellow ink having an L * value of 17 or less when printed in the range of 2.10 is used.   The red ink containing CI Pigment Red 81, CI Pigment Violet 1 or CI Pigment Red 169 in an amount of 15 to 30% by weight based on the total weight of the ink is used as the metal lake compound of the rhodamine dye. Lithographic printing method.   2. The lithographic printing method according to claim 1, wherein the phthalocyanine compound is an indigo ink containing 10 to 25% by weight of C.I. Pigment Blue 15: 3 or C.I. Pigment Blue 15: 4 based on the total weight of the ink. The indigo ink according to claim 4, wherein the specific surface area of CI Pigment Blue 15: 3 or CI Pigment Blue 15: 4 is 74 m ² / g or more.   CI Pigment Green 7 or C.I. The indigo ink according to claim 4, wherein the pigment green 36 is contained in an amount of 0.5 to 2.0% by weight based on the total weight of the ink.   As the methyl violet lake compound, purple ink containing CI pigment violet 3, CI pigment violet 3: 1, CI pigment violet 3: 3, and CI pigment violet 27 in an amount of 10 to 30% by weight based on the total weight of the ink is used. The planographic printing method according to claim 1.   The lithographic printing method according to claim 1, wherein a purple ink containing 10 to 30% by weight of C.I. Pigment Violet 23 and C.I. Pigment Violet 37 is used as the dioxazine violet compound.   2. The lithographic printing method according to claim 1, wherein a purple ink containing 10 to 30% by weight of C.I. pigment violet 25 and C.I. pigment violet 50 based on the total weight of the ink is used as the naphthol violet compound. The planographic printing method according to claim 1, wherein the reflectance of (a) yellow, (b) red, and (c) indigo is as follows:
(A) In the wavelength region of 400 nm to 700 nm, when the maximum reflectance is 100%, the wavelength region of 400 nm to 480 nm is 1 to 20%, and the reflectance in the wavelength region of 540 nm to 700 nm is 90 to 100%. A yellow ink containing 5 to 15% by weight of a coloring component characterized by having a reflection spectrum based on the total weight of the ink;
(B) In the wavelength region of 400 nm to 700 nm, when the maximum reflectance is 100%, the maximum reflectance in the wavelength region of 400 nm to 500 nm is 50% to 100%, 500 nm.
The reflectance in the wavelength region of ˜560 nm is 1 to 20%, and the reflectance of 640 nm to 700 nm is 9%.
A red ink containing 15 to 30% by weight of a coloring component characterized by having a reflection spectrum of 0% to 100%, based on the total weight of the ink;
(C) In the wavelength region of 400 nm to 700 nm, when the maximum reflectance is 100%, the reflectance in the wavelength region of 420 nm to 530 nm is 50 to 100%, 600 nm to 700 n.
magenta ink containing 10 to 25% by weight of a coloring component characterized by having a reflectance spectrum of 1 to 20% of the reflectance of m, based on the total weight of the ink,
A lithographic printing method characterized in that:   The ink set used for the lithographic printing method in any one of Claims 1-10. A printed matter printed using the planographic printing method according to claim 1.