JP2023164228A - Printing ink set, printed matter, and packaging material - Google Patents

Abstract

To provide a printing ink set having excellent light resistance and excellent color reproducibility.SOLUTION: A printing ink set comprises: yellow ink containing an isoindoline compound represented by the formula (1) or C.I. Pigment Yellow 180 and a dispersion medium; cyan ink containing a phthalocyanine pigment and a dispersion medium; magenta ink A containing C.I. Pigment Red 122 and a dispersion medium; and magenta ink B containing C.I. Pigment Violet 19 and a dispersion medium. In the formula, R1 to R4 independently represent a hydrogen atom, an alkyl group, or an alkoxy group, R5 and R6 each independently represent a hydrogen atom or an alkyl group, and X1 represents -O- or -NH-, and R7 represents a hydrogen atom, an alkyl group, or an aryl group.SELECTED DRAWING: None

Description

Embodiments of the invention relate to printing ink sets, printed products, and packaging materials comprising printing inks of at least three primary colors.

Printing inks contain pigments as main ingredients and a dispersion medium, and are used to form printing layers on base materials such as various plastics and paper. Printing inks are broadly classified in terms of their printing methods or uses. For example, from the viewpoint of printing methods, examples include offset printing ink, flexo printing ink, gravure printing ink, and silk screen printing ink.
Furthermore, printing inks are configured to suit various uses and can be broadly classified according to the form of the dispersion medium. Examples include solvent-free (active energy ray-curable) printing inks containing a resin as a dispersion medium and solvent-based printing inks containing an organic solvent as a dispersion medium. Further examples include aqueous printing inks containing resin and water as a dispersion medium.

Printing inks are thus used in various printing methods and configured in various forms. Applications of printing ink include printed matter and packaging materials using printed matter. Examples of printed materials include posters, labels, medicine boxes, and other materials in which a printed layer is formed on a base material. Furthermore, examples of packaging materials include packaging materials for packaging articles such as foodstuffs, beverages, daily necessities, cultural goods, and electronic parts.
Printing inks used for printed matter and packaging materials are required to have at least color reproducibility. However, in recent years, the uses of printed matter and packaging materials have expanded significantly, and the forms of use of printed matter and packaging materials have become diverse. Therefore, various performances are required of printing inks used for printed matter and packaging materials.

For example, packaging materials are required to have a function to maintain the quality of the contents, improve transportation efficiency, and the like, as well as a function to appropriately display product information about the contents. In order to display product information appropriately, a printing layer is formed on the packaging material for the purpose of decoration, imparting aesthetic appearance, displaying contents, expiration date, manufacturer or seller, etc. Display by such a printed layer is very important information for logistics personnel and consumers. Brand marks or brand colors are sometimes used as product information, and in this case, printed matter and packaging materials are required to have a high level of design, including the provision of aesthetic appeal. Therefore, there is a need for printing inks that have color reproducibility that can be suitably used in printed matter and packaging material applications.

Also, for example, when printed materials or packaging materials are used outdoors, problems may arise in which discoloration or fading occurs due to sunlight. Additionally, packaging materials and packages may be stored under light irradiation for long periods of time. Even under such storage conditions, discoloration may occur, causing a problem in which the packaging deviates from the intended appearance. Furthermore, when used as a packaging material, the influence of radicals generated by light irradiation during storage may cause a decrease in the cohesive force or adhesion of the printed layer, resulting in a decrease in laminate strength. As a result, when unsealing packages and packaging materials that have been stored for a long period of time under light irradiation, a problem may arise in which interphase delamination of the laminate occurs.

From this point of view, it is desirable that printing inks used for printed matter or packaging materials have excellent durability such as weather resistance and light resistance in addition to excellent color reproducibility. In particular, for light irradiation during storage, sunlight or fluorescent lamps have conventionally been commonly used as the light source for irradiation, but in recent years white LEDs have been increasingly used for indoor irradiation. Therefore, printing inks may be required to have durability such as light resistance that is different from conventional printing inks.

As mentioned above, printing inks are typically required to have excellent color reproducibility and durability such as weather resistance and light resistance, and various studies are underway.
For example, methods of imparting light resistance to packaging materials are being considered. For example, Patent Document 1 discloses that a printing ink containing a specific pigment and a polyurethane resin can be used to provide a packaging material with excellent light resistance. Furthermore, Patent Document 2 discloses that by using printing ink to which a certain amount of an ultraviolet absorber or a light stabilizer is added, deterioration of the coating film due to light irradiation is suppressed, and a packaging material with excellent light resistance can be provided. ing.

Japanese Patent Application Publication No. 2012-136582 Japanese Patent Application Publication No. 2006-70190

However, when a printing ink containing a specific pigment is used, as in the method described in Patent Document 1, the reproducible color gamut is lower than that of typical printing inks used for packaging materials, resulting in a lower color range than desired. It tends to be difficult to obtain a good design quality. Further, in the method of Patent Document 2, the ultraviolet absorber or light stabilizer used is expensive, so the manufacturing cost of the printing ink increases. Furthermore, when an ultraviolet absorber or a light stabilizer is added to a printing ink, the stability of the ink over time may decrease and gelation may occur.
As described above, further studies are desired toward the realization of a printing ink that has excellent color reproducibility and excellent durability such as weather resistance and light resistance. There is also a need for printing ink sets that can reproduce a wider color gamut and have less color change over time for applications such as packaging materials that require a high degree of design.

Therefore, in view of the above-mentioned situation, the present invention provides a printing ink set that has excellent light resistance and excellent color reproducibility. Furthermore, the present invention provides printed matter and packaging materials that use the above-mentioned printing ink set and have excellent design, light resistance, and adhesiveness of the printed layer.

Embodiments of the present invention relate to the following. However, the embodiments of the present invention are not limited to the following, and include various embodiments.
[1] Isoindoline compound represented by the following general formula (1) or C.I. I. Yellow ink containing Pigment Yellow 180 and a dispersion medium;
cyan ink comprising a phthalocyanine pigment and a dispersion medium;
C. I. magenta ink A containing pigment red 122 and a dispersion medium, and C. I. A printing ink set comprising magenta ink B containing pigment violet 19 and a dispersion medium.

In general formula (1), R ₁ to R ₄ each independently represent a hydrogen atom, an alkyl group, or an alkoxy group. R ₅ and R ₆ each independently represent a hydrogen atom or an alkyl group. X ₁ represents -O- or -NH-, and R ₇ represents a hydrogen atom, an alkyl group, or an aryl group.

[2] The printing ink according to [1] above, wherein the isoindoline compound represented by the above general formula (1) contains at least one compound selected from the group consisting of the following formulas (4) and (5). set.

[3] The printing ink set according to [1] or [2] above, which is used for gravure printing.

[4] The printing ink set according to [1] or [2] above, which is used for flexographic printing.

[5] A printed matter comprising a base material and a printing layer formed from the printing ink set according to any one of [1] to [4] above.

[6] A packaging material comprising the printed matter according to [5] above.

According to the present invention, it is possible to provide a printing ink set that has a color gamut equivalent to or greater than that of conventional printing inks, excellent light resistance, and high color reproducibility. Further, by using the above printing ink set, it is possible to provide printed matter and packaging materials that have excellent design and light resistance.

First, the terms used in this specification will be defined. When expressed as "(meth)acryloyl" or "(meth)acrylic", unless otherwise specified, they mean "acryloyl and/or methacryloyl" and "acrylic and/or methacrylic", respectively. Similarly, when "(meth)acrylic acid", "(meth)acrylate", or "(meth)acrylamide" is written, "acrylic acid and/or methacrylic acid", "acrylate and/or methacrylate", or "acrylamide and/or methacrylamide".
Moreover, "C.I." means color index (C.I.).
In this specification, numerical ranges specified using "-" shall include the numerical values written before and after "-" as the lower limit and upper limit ranges.
Unless otherwise noted, the various components described herein may be used independently, one type alone, or two or more types may be used in combination.

The average primary particle diameter of the pigment is a value obtained by directly measuring the size of the primary particles from an electron micrograph using a transmission electron microscope (TEM). This can be measured according to the method described in the Examples section below.

Embodiments of the present invention will be described below. However, the present invention is not limited to the following description, and includes various embodiments.
<Printing ink set>
One embodiment of the invention relates to a printing ink set comprising printing inks of at least three primary colors. The above printing ink set contains an isoindoline compound represented by general formula (1) or C.I. I. Pigment Yellow 180 and a dispersion medium; a cyan ink containing a phthalocyanine pigment and a dispersion medium; I. Pigment Red 122 and a dispersion medium, magenta ink A, and C.I. I. A magenta ink B containing pigment violet 19 and a dispersion medium is provided.

In one embodiment, the printing ink set may further include other inks, such as black ink, white ink, and special color ink, in addition to the above four printing inks.

The printing ink set of this embodiment can be applied to various printing methods. The printing ink set can be used, for example, as a printing ink set such as offset printing ink, flexo printing ink, gravure printing ink, screen printing ink, etc. Among these, printing ink sets for gravure printing (hereinafter also referred to as gravure printing ink sets) and printing ink sets for flexographic printing (hereinafter also referred to as flexographic printing ink sets) are preferred, and these are suitable for use in packaging materials. It can be used for.

Each color of ink in the printing ink set of this embodiment will be explained below.
<Yellow ink>
The yellow ink in the printing ink set is an isoindoline compound represented by the following general formula (1) or C.I. I. Pigment Yellow 180 and a dispersion medium to be described later.

[Isoindoline compound (1)]
Hereinafter, the isoindoline compound represented by general formula (1) will be referred to as isoindoline compound (1).

In general formula (1), R ₁ to R ₄ each independently represent a hydrogen atom, an alkyl group, or an alkoxy group. R ₅ and R ₆ each independently represent a hydrogen atom or an alkyl group. X ₁ represents -O- or -NH-, and R ₇ represents a hydrogen atom, an alkyl group, or an aryl group.

The isoindoline compound (1) can be used alone or in combination of two or more.

In general formula (1), the number of carbon atoms in the alkyl group (-R) in R ₁ to R ₄ is preferably 1 to 20, more preferably 1 to 10, even more preferably 1 to 4, and even more preferably 1 to 3. . Most preferred are alkyl groups having 1 or 2 carbon atoms.
The alkyl group may have a linear structure, a branched structure, a monocyclic structure, or a condensed polycyclic structure.
Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, octadecyl group, isopropyl group, isobutyl group, and isopentyl group. , 2-ethylhexyl group, 2-hexyldodecyl group, sec-butyl group, tert-butyl group, sec-pentyl group, tert-pentyl group, tert-octyl group, neopentyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, Examples include cyclohexyl group, adamantyl group, norbornyl group, boronyl group, and 4-decylcyclohexyl group.

The alkyl group mentioned above has at least one hydrogen atom substituted with another group such as a halogen atom, hydroxyl group, alkoxy group, carboxyl group, ester group, sulfo group, sulfanyl group, sulfamoyl group, amino group, alkylamino group, or amide group. May be substituted with groups. Moreover, a plurality of substituents may exist. Note that the substituents are not limited to those mentioned above.

The above alkyl group may have a structure in which two or more alkyl groups (however, one becomes an alkylene group) are bonded to each other via a linking group. Specific examples of the linking group include an ester bond (-COO-), an ether bond (-O-), and a sulfide bond (-S-). That is, in this specification, the alkyl group includes, for example, a group represented by "-R'-O-R"(R' represents an atomic group obtained by removing one hydrogen atom from the above alkyl group). . A specific example is -C ₂ H ₄ -O-C ₂ H ₅ .

In the general formula (1), the alkoxy group in R ₁ to R ₄ is a group (-OR) in which an oxygen atom is bonded to the above-mentioned alkyl group (-R).

In general formula (1), the alkyl group (-R) in R ₅ to R ₇ is the same as the alkyl group in R ₁ to R ₄ .

In the general formula (1), the aryl group (-Ar) in R ₇ is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon. The number of carbon atoms is preferably 6 to 30, more preferably 6 to 20.
The above aryl group is, for example, a phenyl group, tolyl group, biphenylyl group, terphenylyl group, quarterphenyl group, pentalenyl group, indenyl group, naphthyl group, binaphthalenyl group, ternaphthalenyl group, quarternaphthalenyl group, azulenyl group, hepthalenyl group. , biphenylenyl group, indacenyl group, fluoranthenyl group, acephenanthrylenyl group, aceantrylenyl group, phenalenyl group, fluorenyl group, anthryl group, bianthracenyl group, teranthracenyl group, quarteranthracenyl group, anthraquinolyl group , phenanthryl group, triphenylenyl group, pyrenyl group, chrysenyl group, naphthacenyl group, plaiadenyl group, picenyl group, perylenyl group, pentaphenyl group, pentacenyl group, tetraphenylenyl group, hexaphenyl group, hexacenyl group, rubicenyl group, coronenyl group group, trinaphthylenyl group, heptaphenyl group, heptacenyl group, pyranthrenyl group, or obalenyl group. Among these, phenyl group and tolyl group are preferred.

The above aryl group has at least one hydrogen atom that is a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, an ester group, a sulfo group, a sulfanyl group, a sulfamoyl group, an amino group, an alkylamino group, or another substituent such as an amide group. may be replaced with Moreover, you may have multiple substituents. Note that the substituents are not limited to those mentioned above.

In general formula (1), X ₁ represents -O- or -NH-, preferably -NH-.

The isoindoline compound represented by the general formula (1) preferably contains at least one compound selected from the group consisting of the following formulas (4) and (5).

By using the isoindoline compound represented by formula (4) (hereinafter referred to as isoindoline compound (4)) or the isoindoline compound represented by formula (5) (hereinafter referred to as isoindoline compound (5)), Achieves both higher color reproducibility and light resistance.

[Method for producing isoindoline compound (1)]
Isoindoline compound (1) can be synthesized using 1,3-diiminoisoindoline represented by formula (6) (hereinafter referred to as compound (6)) as a starting material, as shown in Scheme 1 below.
Hereinafter, the synthesis method will be explained along with specific examples of isoindoline compound (1). In the following explanation, the numbers described in each formula are described as compound numbers.

Scheme 1-1 shows the first step (S1) of reacting compound (6) and compound (7) in the presence of an aqueous ammonia solution; then, the reaction of compound (8) and compound ( A second step (S2) of reacting with 9) may be included.
In the first step (S1) of Scheme 1-1, when using a 28% ammonia aqueous solution, the amount of ammonia aqueous solution used is preferably 1 to 20 times the amount of 100 parts by mass of compound (6), and 1 An amount of ~5 times is more preferred.
The reaction temperature in each step in Scheme 1-1 is preferably about 10 to 100°C.

When the relationship between substituents R ₁ and R ₄ , the relationship between substituents R ₂ and R ₃ , or the relationship between substituents R ₅ and R ₆ of the isoindoline compound (1) is asymmetric, the final product is an isomer. obtained as a mixture containing The isoindoline compound (1) may be a mixture containing isomers or a single compound.

It is preferable to prepare a pigment from the isoindoline compound (1) by subjecting it to granulation treatment or surface treatment using a known method. Examples include dissolution precipitation methods typified by acid pasting, solvent salt milling, dry milling, and the like.

[C. I. Pigment Yellow 180]
C. I. Pigment Yellow 180 is a pigment consisting of a compound represented by the following formula (10), and is produced by a known method.

C. I. The average primary particle diameter of Pigment Yellow 180 is preferably 70 to 250 nm, more preferably 100 to 200 nm. When the average primary particle diameter is 250 nm or less, transparency can be improved and high color reproducibility can be obtained. Furthermore, when the average primary particle diameter is 70 nm or more, light resistance is further improved.

The yellow ink may further contain yellow pigments other than the above pigments (hereinafter referred to as other yellow pigments), resins, organic solvents, pigment dispersants, and other additives, to the extent that the effects of the present invention are not impaired. It's okay.

Other yellow pigments include, for example, C.I. I. Pigment Yellow 12, C. I. Pigment Yellow 13, C. I. Pigment Yellow 14, C. I. Pigment Yellow 17, C. I. Pigment Yellow 83, C. I. Pigment Yellow 93, C. I. Pigment Yellow 95, C. I. Pigment Yellow 109, C. I. Pigment Yellow 110, C. I. Pigment Yellow 120, C. I. Pigment Yellow 138, C. I. Pigment Yellow 151, C. I. Pigment Yellow 155, C. I. Pigment Yellow 174 and the like. Also included are isoindoline compounds represented by the following general formulas (2-1) and (2-2). However, the use of these other yellow pigments should be kept to a minimum because there is a risk that the light resistance or color reproduction gamut may be reduced.

Among the pigments contained in the yellow ink, isoindoline compound (1) and C.I. I. The content of Pigment Yellow 180 is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, particularly 95% by mass or more. preferable. Isoindoline compound (1) and C.I. I. When both Pigment Yellow 180 are included, the total is preferably within the above range.

In general formula (2-1), R ₁₁ to R ₁₄ each independently represent a hydrogen atom, an alkyl group, or an alkoxy group. R ₁₅ to R ₁₈ each independently represent a hydrogen atom or an alkyl group.
Furthermore, in the general formula (2-2), R ₁₉ represents an alkyl group which may have a substituent.

In the above formula (2-1), the alkyl group (-R) and alkoxy group in R ₁₁ to R ₁₄ are the same as the alkyl group and alkoxy group in R ₁ to R ₄ in formula (1). Furthermore, in the above formula (2-1), the alkyl group (-R) in R ₁₅ to R ₁₈ is the same as the alkyl group in R ₅ to R ₆ in formula (1).
Furthermore, in the above formula (2-2), the alkyl group (-R) in R ₁₉ is the same as the alkyl group in R ₁ to R ₄ in formula (1), and the same applies to the substituents.

<Cyan ink>
The cyan ink in the printing ink set contains a phthalocyanine pigment and a dispersion medium described below.

[Phthalocyanine pigment]
The phthalocyanine pigment is a pigment made of a compound represented by the following general formula (3), and can be produced by a known method.

In general formula (3), R ₁₀₁ to R ₁₁₆ each independently represent a hydrogen atom, a halogen atom, and an alkyl group, an aryl group, an alkoxyl group, and an aryloxy group which may have a substituent. . M represents two hydrogen atoms, two monovalent metal atoms, a divalent metal atom, a trivalent substituted metal atom, a tetravalent substituted metal atom, or a metal oxide atom. In one embodiment, the phthalocyanine pigment is preferably a metal phthalocyanine pigment. That is, M is preferably two monovalent metal atoms, a divalent metal atom, a trivalent substituted metal atom, a tetravalent substituted metal atom, or a metal oxide atom. M is more preferably a divalent metal atom, a trivalent substituted metal atom, a tetravalent substituted metal atom, or an oxidized metal atom, and even more preferably a divalent metal atom.

Examples of the alkyl group include linear or branched alkyl groups. Specific examples include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, octadecyl group, isopropyl group, isobutyl group, isopentyl group, Examples include 2-ethylhexyl group, sec-butyl group, tert-butyl group, sec-pentyl group, tert-pentyl group, tert-octyl group, and neopentyl group. The number of carbon atoms in the alkyl group is preferably within the range of 1 to 30.

Substituents for the above alkyl groups include halogen atoms such as fluorine, chlorine, and bromine, hydroxyl groups, amino groups, nitro groups, formyl groups, cyano groups, carboxyl groups, and the following aryl groups, cycloalkyl groups, and heterocycles. Examples include groups. In addition, those in which a part of the structure is substituted with an ester bond (-COO-) or an ether bond (-O-) are also included as substituents.

Therefore, the substituted alkyl group means an alkyl group substituted with the above-mentioned substituents. It may be substituted with one or more substituents. For example, specific examples of alkyl groups substituted with halogen atoms include trifluoromethyl group, 2,2,2-trifluoroethyl group, -(CF ₂ ) ₄ CF ₃ , -(CF ₂ ) ₅ CF ₃ , Examples include -(CF ₂ ) ₆ CF ₃ , -(CF ₂ ) ₇ CF ₃ , -(CF ₂ ) ₈ CF ₃ , trichloromethyl group, 2,2-dibromoethyl group, and the like.

Examples of the aryl group include monocyclic or condensed polycyclic aryl groups. For example, phenyl group, 1-naphthyl group, 2-naphthyl group, p-biphenyl group, m-biphenyl group, 2-anthryl group, 9-anthryl group, 2-phenanthryl group, 3-phenanthryl group, 9-phenanthryl group, 2-fluorenyl group, 3-fluorenyl group, 9-fluorenyl group, 1-pyrenyl group, 2-pyrenyl group, 3-perylenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 4-methylbiphenyl group , terphenyl group, 4-methyl-1-naphthyl group, 4-tert-butyl-1-naphthyl group, 4-naphthyl-1-naphthyl group, 6-phenyl-2-naphthyl group, 10-phenyl-9-anthryl group group, spirofluorenyl group, 2-benzocyclobutenyl group, and the like. The number of carbon atoms in the aryl group is preferably within the range of 6 to 18. Examples of the substituent for the substituted aryl group include the same substituents as those for the alkyl group described above.

Examples of the alkoxyl group include linear or branched alkoxyl groups. Specific examples include methoxy group, ethoxy group, propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, tert-butoxy group, neopentyloxy group, 2,3-dimethyl-3-pentyloxy group, n- Examples include hexyloxy group, n-octyloxy group, stearyloxy group, and 2-ethylhexyloxy group. The number of carbon atoms in the alkoxyl group is preferably within the range of 1 to 6. Examples of the substituent for the substituted alkoxyl group include the same substituents as those for the alkyl group described above.

Examples of the aryloxy group include monocyclic or fused polycyclic aryloxy groups. Specific examples include phenoxy group, p-methylphenoxy group, naphthyloxy group, and anthryloxy group. The aryloxy group is preferably a monocyclic aryloxy group. Furthermore, an aryloxy group having 6 to 12 carbon atoms is preferred.

Examples of the monovalent metal atom of M include Na, K, Li, and the like.
Examples of metal atoms included in the divalent metal atom, trivalent substituted metal atom, tetravalent substituted metal atom, or oxidized metal atom of M include metal atoms belonging to Groups 2 to 15 of the periodic table. can be mentioned. Specific examples of divalent metal atoms include Cu, Zn, Fe, Co, Ni, Ru, Pb, Rh, Pd, Pt, Mn, Sn, Pb, Ca, Mg, and the like.
Examples of trivalent substituted metal atoms include metal atoms such as Al, Ga, In, Tl, Cr, Mn, Fe, and Ru, halogen atoms (-F, -Cl, -Br, -I), hydroxyl groups, Examples include those to which substituents such as an aryl group, an aryloxy group, a silyloxy group, a phosphinyl group, and a phosphonyl group, which may have a substituent, are bonded.
Examples of tetravalent substituted metal atoms include halogen atoms (-F, -Cl, -Br, -I), hydroxyl groups, and substituents on metal atoms such as Cr, Si, Zr, Ge, Sn, Ti, and Mn. Examples include those in which two substituents such as an aryl group, an aryloxy group, a silyloxy group, a phosphinyl group, and a phosphonyl group, which may have a bond, are bonded.
Examples of the metal oxide atoms include VO, MnO, TiO, and the like.
M is preferably Cu, Zn, Fe, Ca, Mg, Al-OH, or TiO, more preferably Cu, Al-OH, or TiO, and even more preferably Cu.

Among the general formula (3), copper phthalocyanine in which M is Cu (compound (11)), aluminum phthalocyanine in which M is Al-OH (compound (12)), titanyl phthalocyanine in which M is TiO (compound (13)), )) is preferred.

In one embodiment, the phthalocyanine pigment is C.I. I. Pigment Blue 15, C. I. Pigment Blue 15:1, C. I. Pigment Blue 15:2, C. I. Pigment Blue 15:3, C. I. Pigment Blue 15:4, C. I. Pigment Blue 15:6, C. I. Pigment Blue 16, etc. Among them, C. I. Pigment Blue 15:3, C. I. Pigment Blue 15:4, and C.I. I. Pigment Blue 15:6, preferably containing at least one copper phthalocyanine pigment selected from the group consisting of C. I. Pigment Blue 15:3, or C.I. I. More preferably, it contains Pigment Blue 15:4.

The cyan ink can further contain blue pigments other than the above-mentioned pigments (hereinafter referred to as other blue pigments), resins, organic solvents, pigment dispersants, and other additives, as long as the effects of the present invention are not impaired. .

Other blue pigments include, for example, C.I. I. Pigment Blue 60 and the like.

The content of the phthalocyanine pigment in the pigment contained in the cyan ink is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and 95% by mass or more. % or more is particularly preferable.

The printing ink set of this embodiment is characterized in that it includes two types of magenta ink, magenta ink A and magenta ink B, which will be described later.
<Magenta ink A>
Magenta ink A in the printing ink set of this embodiment is C.I. I. Pigment Red 122 and a dispersion medium to be described later.

C. I. Pigment Red 122 is C. I. Pigment Red 202, C. I. Pigment Red 209, C. I. It may be a mixed crystal with other quinacridone compounds such as Pigment Violet 19. However, in order to maximize the effects of the present invention, it is necessary to use C.I. I. Pigment Red 122 alone is preferred.

Among the pigments contained in magenta ink A, C. I. The content of Pigment Red 122 is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, particularly 95% by mass or more. preferable.

C. I. The average primary particle diameter of Pigment Red 122 is preferably 50 to 150 nm, more preferably 60 to 130 nm. When the average primary particle diameter is 150 nm or less, transparency can be improved and high color reproducibility can be obtained. Furthermore, when the average primary particle diameter is 50 nm or more, light resistance is further improved.

<Magenta ink B>
Magenta ink B in the printing ink set of this embodiment is C.I. I. Pigment Violet 19 and a dispersion medium to be described later.

C. I. Pigment Violet 19 has crystal polymorphism, but the crystal form is preferably the γ type.

C. I. Pigment Violet 19 is C. I. Pigment Red 122, C. I. Pigment Red 202, C. I. It may be a mixed crystal with other quinacridone compounds such as Pigment Red 209. However, in order to maximize the effects of the present invention, it is necessary to use C.I. I. Pigment Violet 19 alone is preferred.

Among the pigments contained in magenta ink B, C. I. The content of Pigment Violet 19 is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, particularly 95% by mass or more. preferable.

C. I. The average primary particle diameter of Pigment Violet 19 is preferably 30 to 120 nm, more preferably 40 to 100 nm. When the average primary particle diameter is 120 nm or less, transparency can be improved and high color reproducibility can be obtained. Furthermore, when the average primary particle diameter is 30 nm or more, light resistance is further improved.

In one embodiment, magenta ink A and magenta ink B are inks whose hue angle (H°) calculated based on the following formula (A) is 0° or more and less than 90°, or 300° or more and less than 360°. It may be a combination of inks. In formula (A), a* and b* represent values obtained by measuring a* and b* in the L*a*b* color system defined by CIE (Commission Internationale de Illumination). There is.
The values of a* and b* can be measured, for example, using a spectrophotometer (trade name: Spectrolino; manufactured by Gretag Macbeth). Of course, the spectrophotometer used to measure a* and b* is not limited to the above.
Formula (A)
If a*≧0, b*≧0 (first quadrant), H°=tan ⁻¹ (b*/a*)
When a*≦0, b*≧0 (second quadrant), H°=180+tan ^-1 (b*/a*)
When a*≦0, b*≦0 (third quadrant), H°=180+tan ^-1 (b*/a*)
When a*≧0, b*≦0 (fourth quadrant), H°=360+tan ⁻¹ (b*/a*)

Further, in one embodiment, the relationship between the hue angle (H _A °) of magenta ink A and magenta ink B (H _B °) preferably satisfies the following criteria.
(1) If 300≦H _A °<360, 300≦H _B °<360, H _A °<H _B °
(2) If 300≦H _A °<360, 0≦H _B °<90, H _A °>H _B °
(3) If 0≦H _A °<90, 0≦H _B °<90, then H _A °<H _B °

Magenta ink A and magenta ink B each contain red pigments other than the above pigments (hereinafter referred to as "other red pigments"), resins, organic solvents, pigment dispersants, and others, within a range that does not impair the effects of the present invention. It may contain additives, etc.

Other red pigments include, for example, C.I. I. Pigment Red 2, C. I. Pigment Red 32, C. I. Pigment Red 48:1, C.I. I. Pigment Red 48:2, C. I. Pigment Red 48:3, C.I. I. Pigment Red 53:1, C.I. I. Pigment Red 57:1, C.I. I. Pigment Red 63:1, C.I. I. Pigment Red 81, C. I. Pigment Red 122, C. I. Pigment Red 144, C. I. Pigment Red 146, C. I. Pigment Red 149, C. I. Pigment Red 150, C. I. Pigment Red 166, C. I. Pigment Red 170, C. I. Pigment Red 174, C. I. Pigment Red 178, C. I. Pigment Red 179, C. I. Pigment Red 184, C. I. Pigment Red 185, C. I. Pigment Red 188, C. I. Pigment Red 190, C. I. Pigment Red 202, C. I. Pigment Red 207, C. I. Pigment Red 208, C. I. Pigment Red 209, C. I. Pigment Red 214, C. I. Pigment Red 220, C. I. Pigment Red 221, C. I. Pigment Red 224, C. I. Pigment Red 238, C. I. Pigment Red 242, C. I. Pigment Red 254, C. I. Pigment Red 255, C. I. Pigment Red 260, C. I. Pigment Red 264, C. I. Pigment Red 269, C. I. Pigment Red 272, C. I. Pigment Violet 19 and the like. However, it is best to keep its use to a minimum as it may reduce light fastness and color reproduction.

Components other than the above-mentioned essential pigments will be explained below. The components described below may be included in the printing ink of this embodiment, or may be added as necessary.
<Pigment>
The printing ink set of this embodiment may further contain pigments shown below in addition to the above pigments. Examples of the pigment to be added include organic pigments and inorganic pigments other than the above pigments.

[Organic pigment]
The pigment to be added is preferably an organic pigment. Examples of organic pigments include soluble azo, insoluble azo, azo, phthalocyanine, halogenated phthalocyanine, anthraquinone, anthanthrone, dianthraquinonyl, anthrapyrimidine, perylene, perinone, and quinacridone. , thioindigo type, dioxazine type, isoindolinone type, quinophthalone type, azomethine azo type, flavanthrone type, diketopyrrolopyrrole type, isoindoline type, indanthrone type and the like.

Examples other than the pigments mentioned above include C. I. Indicated by pigment number.

The purple pigment is, for example, C.I. I. Pigment Violet 23, C. I. Pigment Violet 32, C. I. Pigment Violet 37 and the like.

The green pigment is, for example, C.I. I. Pigment Green 7 and the like.

The orange pigment is, for example, C.I. I. Pigment Orange 13, C. I. Pigment Orange 34, C. I. Pigment Orange 38, C. I. Pigment Orange 43, C. I. Pigment Orange 64 and the like.

Examples of the special color ink include inks other than cyan, magenta, and yellow, such as purple, grass, and vermilion. In one embodiment, the special color ink preferably contains the above-mentioned purple pigment, green pigment, orange pigment, and the like.

[Inorganic pigment]
Inorganic pigments include, for example, white inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, lithobon, antimony white, and gypsum, carbon black, iron black, and copper/chromium composite oxide. Examples include black inorganic pigments such as aluminum particles, mica, bronze powder, chrome vermilion, chrome yellow, cadmium red, ultramarine blue, deep blue, red iron oxide, yellow iron oxide, zircon, and the like.

It is preferable to use carbon black as the ink (black ink) from the viewpoint of excellent coloring power, hiding power, chemical resistance, and weather resistance. I. Pigment Black 7 and the like. Moreover, it is preferable to use titanium oxide for the white ink (white ink) from the viewpoint of excellent coloring power, hiding power, chemical resistance, and weather resistance. From the viewpoint of printing performance, titanium oxide is preferably surface-treated with silica and/or alumina.

Each ink can use a single pigment or a combination of two or more pigments in order to obtain a desired color tone.

The average primary particle diameter of the pigment is preferably in the range of 10 to 200 nm, more preferably in the range of 50 to 150 nm.
The content of pigment in the ink is preferably in the range of 0.1 to 60% by mass based on the mass of the ink, and based on the mass of non-volatile matter of the ink, in order to ensure the concentration and coloring power of the ink. , preferably in the range of 10 to 90% by mass.

[Dye derivative]
Each ink constituting the printing ink set of this embodiment may contain a dye derivative.
A dye derivative is a known compound having an acidic group, a basic group, a neutral group, etc. in an organic dye residue. Pigment derivatives include, for example, compounds having acidic substituents such as sulfo groups, carboxyl groups, phosphoric acid groups, amine salts thereof, compounds having sulfonamide groups and basic substituents such as tertiary amino groups at the terminals, and , a compound having a neutral substituent such as a phenyl group and a phthalimide alkyl group.
Examples of organic pigments include diketopyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, perinone pigments, perylene pigments, thiazine indigo pigments, triazine pigments, benzimidazolone pigments, and benzene pigments. Examples include indole pigments such as isoindole, isoindoline pigments, isoindolinone pigments, quinophthalone pigments, naphthol pigments, threne pigments, metal complex pigments, and azo pigments such as azo, disazo, and polyazo. .
The dye derivative may be a known dye derivative, and is specifically described, for example, in the following documents.
Diketopyrrolopyrrole dye derivatives: JP2001-220520, WO2009/081930, WO2011/052617, WO2012/102399, and JP2017-156397 Phthalocyanine dye derivatives: JP2007-156397 -226161 publication, WO2016/163351 pamphlet, JP2017-165820A, and Patent No. 5753266 Anthraquinone dye derivative: JP63-264674A, JP09-272812A, JP1999-10A -245501, JP 10-265697, JP 2007-079094, and WO 2009/025325 pamphlet Quinacridone dye derivatives: JP 48-54128, JP 03-9961, and JP-A-2000-273383 Dioxazine dye derivatives: JP-A-2011-162662 Thiazine indigo-based dye derivatives: JP-A 2007-314785 Triazine-based dye derivatives: JP-A-61-246261, JP-A-11 -199796, JP 2003-165922, JP 2003-168208, JP 2004-217842, and JP 2007-314681 Benziisoindole dye derivatives: JP 2009-57478 Publication Quinophthalone dye derivatives: JP 2003-167112, JP 2006-291194, JP 2008-31281, and JP 2012-226110 Naphthol dye derivatives: JP 2012-208329 , and JP-A No. 2014-5439 Azo dye derivative: JP-A No. 2001-172520 and JP-A No. 2012-172092 Acidic substituents are described in JP-A No. 2004-307854. Furthermore, basic substituents are described in JP-A No. 2002-201377, JP-A No. 2003-171594, JP-A No. 2005-181383, and JP-A No. 2005-213404.
In addition, in the said literature, a pigment derivative may be described as a derivative, a pigment derivative, a dispersant, a pigment dispersant, or simply a compound. However, a compound having a substituent such as an acidic group, a basic group, or a neutral group on the organic dye residue has the same meaning as a dye derivative.

The dye derivatives can be used alone or in combination of two or more.

<Dispersion medium>
Each ink constituting the printing ink set of this embodiment includes a dispersion medium. A dispersion medium is a medium that appropriately disperses pigments, exhibits performance as an ink, and stabilizes properties. Specific examples of the dispersion medium include resins, solvents, and polymerizable compounds. The resin may be a resin-type dispersant, a binder resin, or the like. Solvents can be water and organic solvents. Moreover, each ink may contain a low-molecular dispersant such as a surfactant as a dispersion medium, if necessary.
The dispersion medium can be appropriately selected depending on the form of the printing ink.

The dispersion medium will be explained in more detail below.
[Resin type dispersant]
The resin type dispersant has a pigment affinity site that adsorbs to the pigment and a relaxing site that has a high affinity for components other than the pigment and causes steric repulsion between dispersed particles. The resin type dispersant has an acidic group or a basic group. Examples of acidic groups include carboxyl groups, sulfo groups, and phosphoric acid groups. Examples of the basic group include primary to tertiary amino groups, quaternary ammonium bases, and the like.
Examples of acidic resin type dispersants include urethane dispersants such as polyurethane, polycarboxylic acid esters such as polyacrylate, unsaturated polyamides, polycarboxylic acids, polycarboxylic acid (partial) amine salts, polycarboxylic acid ammonium salts, and polycarboxylic acid (partial) amine salts. Carboxylic acid alkylamine salts, polysiloxanes, long-chain polyaminoamide phosphates, hydroxyl group-containing polycarboxylic acid esters, and modified products of these; formed by the reaction of poly(lower alkylene imine) with polyesters having free carboxyl groups. (meth)acrylic acid-styrene copolymer, (meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-maleic acid copolymer, polyvinyl alcohol, polyvinylpyrrolidone, etc.; Examples include polyesters, modified polyacrylates, ethylene oxide/propylene oxide adducts, phosphate esters, and the like.
Basic resin type dispersants include nitrogen atom-containing graft copolymers, tertiary amino groups in side chains, quaternary ammonium bases, nitrogen-containing heterocycles, etc. for resin types such as acrylic resins, polyester resins, and urethane resins. A nitrogen atom-containing acrylic block copolymer or a urethane polymer dispersant, which has a functional group containing .

Resin type dispersants are available as commercial products. Examples include:
JONCRYL67, JONCRYL678, JONCRYL586, JONCRYL611, JONCRYL683, JONCRYL690, JONCRYL57J, JONCRYL60J, JONCRYL61J, JONCRYL62J, JON manufactured by BASF Japan. CRYL63J, JONCRYLHPD-96J, JONCRYL501J, JONCRYLPDX-6102B,
DISPERBYK180, DISPERBYK187, DISPERBYK190, DISPERBYK191, DISPERBYK194, DISPERBYK2010, DISPERBYK2015, DISPERBYK2090, DISPERBY manufactured by Big Chemie K2091, DISPERBYK2095, DISPERBYK2155,
SOLSPERSE24000, SOLSPERSE32000, SOLSPERSE39000, SOLSPERSE41000 manufactured by Japan Lubrizol,
SMA1000H, SMA1440H, SMA2000H, SMA3000H, SMA17352H, etc. manufactured by Sartomer.

[Binder resin]
The binder resin may be used as long as it can form a film by printing. For example, it may be a polyolefin resin, a polyester resin, a styrene copolymer, an acrylic resin, or a modified resin thereof. Specifically, polyethylenes such as high-density polyethylene (HDPE), linear low-density polyethylene (L-LDPE), and low-density polyethylene (LDPE); polyolefin resins such as polypropylene; polyester resins such as polyethylene terephthalate; styrene-p -Chlorstyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-methyl chloromethacrylate copolymer Polymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer , styrene copolymers such as styrene-acrylonitrile-indene copolymers; acrylic resins such as acrylic resins and methacrylic resins; polyvinyl chloride, phenolic resins, naturally modified phenolic resins, natural resin-modified maleic acid resins, silicone resins, polyurethane resins , ethylene-vinyl acetate copolymer resin, vinyl acetate resin, nitrocellulose resin, polyamide resin, epoxy resin, xylene resin, polyvinyl butyral resin, polyvinyl acetal resin, cellulose ester resin, alkyd resin, rosin resin, ketone resin, ring Examples include chlorinated rubber, chlorinated polyolefin resin, terpene resin, coumaron indene resin, amino resin, petroleum resin, and modified resins thereof.

[Organic solvent]
Organic solvents can be classified into water-soluble solvents and water-insoluble solvents.
Examples of water-soluble solvents include methanol, ethanol, n-propanol, isopropanol, isobutanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and glycerin.
Examples of the water-insoluble solvent include toluene, xylene, ethyl acetate, n-propyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, butyl alcohol, and aliphatic hydrocarbons.

[water]
The water is preferably ion-exchanged water from which metal ions and the like have been removed, and distilled water.

[Polymerizable compound]
A polymerizable compound is a compound having one or more ethylenically unsaturated bonds in its molecule. Contains monomers and oligomers as polymerizable compounds.

(monomer)
The monomer has a polymerizable group such as a (meth)acryloyl group, allyl group, vinyl group, or vinyl ether group in the molecule. In terms of curability, the monomer preferably contains a monomer having either a (meth)acryloyl group or a vinyl group, and preferably contains a monomer having 3 or more and 6 or less (meth)acryloyl groups in the molecule. is more preferred, and it is even more preferred that the molecule contains a monomer having six (meth)acryloyl groups.

Specific examples of monomers having a (meth)acryloyl group include the following. However, it is not limited to the following.
Monofunctional (meth)acrylate monomers having one (meth)acryloyl group in the molecule: 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, β-carboxylethyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, alkoxylated tetrahydrofurfuryl acrylate, caprolactone (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isoamyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isodecyl (meth)acrylate, 3,3,5-trimethylcyclohexanol (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate Acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (oxyethyl) (meth)acrylate, 1,4-cyclohexanedimethanol (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, benzyl (meth)acrylate , EO-modified (2) nonylphenol acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate, acryloylmorpholine, etc. Difunctional (2) having two (meth)acryloyl groups in the molecule Meth)acrylate monomer: 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexane Diol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate Acrylate, polyethylene glycol (200) di(meth)acrylate, polyethylene glycol (300) di(meth)acrylate, polyethylene glycol (400) di(meth)acrylate, polyethylene glycol (600) di(meth)acrylate, hydroxypivalic acid neo Pentyl glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, EO modified (2) 1,6-hexanediol di(meth)acrylate, PO modified (2) neopentyl Glycol di(meth)acrylate, (neopentyl glycol modified) trimethylolpropane di(meth)acrylate, EO modified (4) bisphenol A di(meth)acrylate, PO modified (4) bisphenol A di(meth)acrylate, cyclohexane di Methanol di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, dicyclopentanyl di(meth)acrylate, etc. Trifunctional (meth)acrylate monomer having three (meth)acryloyl groups in the molecule: trimethylol Propane tri(meth)acrylate, EO modified (3) trimethylolpropane tri(meth)acrylate, EO modified (6) trimethylolpropane tri(meth)acrylate, PO modified (3) trimethylolpropane tri(meth)acrylate, ε - Caprolactone modified tris-(2-acryloxyethyl) isocyanurate, ethoxylated isocyanuric acid tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, pentaerythritol tri(meth)acrylate, etc. In the molecule Tetrafunctional (meth)acrylate monomers having four acryloyl groups in the molecule: pentaerythritol tetra(meth)acrylate, EO-modified (4) pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, etc. ) Pentafunctional (meth)acrylate monomers having five acryloyl groups: dipentaerythritol penta(meth)acrylate, etc. Hexafunctional (meth)acrylate monomers having six (meth)acryloyl groups in the molecule: dipentaerythritol hexa(meth)acrylate, etc. ) Acrylate etc.

Specific examples of monomers having a vinyl group include N-vinyl-2-pyrrolidone, N-vinylcaprolactam, and the like.

(oligomer)
Examples of oligomers include urethane (meth)acrylate oligomers such as aliphatic urethane (meth)acrylate oligomers and aromatic urethane (meth)acrylate oligomers, (meth)acrylic ester oligomers, polyester (meth)acrylate oligomers, and epoxy (meth)acrylates. Examples include oligomers. The oligomer preferably contains about 2 to 16 ethylenically unsaturated bonds. Among these, urethane (meth)acrylate oligomers are preferred, and urethane (meth)acrylate oligomers having 6 to 12 (meth)acryloyl groups are more preferred.

The weight average molecular weight (Mw) of the oligomer is preferably 400 to 10,000, more preferably 500 to 5,000, more preferably 800 to 4,000, and even more preferably 1,000 to 2,000. Here, the "weight average molecular weight (Mw)" can be determined as a polystyrene equivalent molecular weight by general gel permeation chromatography (hereinafter referred to as GPC).

The above-mentioned 6- to 12-functional urethane (meth)acrylate oligomers can also be obtained as commercial products. Specific examples include EBECRYL1290 (6 functional, Mw 1,000), EBECRYL5129 (6 functional, Mw 800), EBECRYL8254 (6 functional, 1,200), and KRM8200 (6 functional, Mw 1,000) manufactured by Daicel Allnex Corporation. ), KRM8904 (9 functional, Mw 1,800), EBECRYL8602 (9 functional, 2,000), KRM8452 (10 functional, Mw 1,200), EBECRYL225 (10 functional, Mw 1,200), EBECRYL8415 (10 functional, Mw 1,200) ). In addition, Miwon Specialty Chemical Co. , Ltd. Miramer PU5000 (6 functional, Mw 1,800), Miramer PU610 (6 functional, Mw 1,800), Miramer PU6140 (6 functional, Mw 1,500), Miramer MU9800 (9 functional, 3,500), Miramer MU9500 (10 functional, Mw3,200 ).

[Other ingredients]
Each ink constituting the printing ink set of the present embodiment may further contain other components such as various additives in addition to the above-mentioned components, depending on the intended use, as long as the effects of the present invention are not reduced. Examples of other components include extender pigments, waxes, antiblocking agents, surfactants, leveling agents, antifoaming agents, preservatives, pH adjusters, ultraviolet absorbers, flame retardants, and antioxidants. These various additives can be further added to the ink as needed.

Examples of extender pigments include calcium carbonate, magnesium carbonate, kaolin, barium sulfate, aluminum hydroxide, silica, clay, talc, mica, and the like. By adding extender pigments, anti-blocking properties, lamination strength, drying properties, coating hiding properties, etc. can be improved.

Waxes include, for example, natural waxes and synthetic waxes. Examples of natural waxes include carnauba wax, Japanese wax, lanolin, montan wax, paraffin wax, and microcrystalline wax. Examples of synthetic waxes include Fischer-Tropsch wax, polyethylene wax, polypropylene wax, polytetrafluoroethylene wax, polyamide wax, and silicone compounds. By adding wax, abrasion resistance, anti-blocking properties, slip properties, anti-scratch properties, etc. can be improved.

Examples of the antiblocking agent include silica particles, polyethylene wax, fatty acid amide, cellulose acetate butyrate resin, cellulose acetate propionate resin, and nitrified cotton.

Examples of the surfactant include anionic surfactants, nonionic surfactants, and the like.
Anionic surfactants include, for example, fatty acid salts, alkyl sulfate ester salts, alkylaryl sulfonates, alkylnaphthalene sulfonates, dialkyl sulfonates, dialkyl sulfosuccinates, alkyl diarylether disulfonates, and alkyl phosphates. , polyoxyethylene alkyl ether sulfate, polyoxyethylene alkylaryl ether sulfate, naphthalene sulfonic acid formalin condensate, and polyoxyethylene alkyl phosphate ester salt.
Examples of nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, and glycerin fatty acid. Examples include ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, glycerol borate fatty acid ester, and polyoxyethylene glycerol fatty acid ester.

Examples of the leveling agent include fluorine-based leveling agents, acrylic polymer-based leveling agents, and silicone-based leveling agents.

Examples of antifoaming agents include mineral oil antifoaming agents, silicone antifoaming agents, non-silicone polymer antifoaming agents, and acetylene glycol antifoaming agents.

Examples of preservatives include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, zinc pyridinethione-1-oxide, 1,2-benzisothiazolin-3-one, 1-benzisothiazolin-3- Examples include amine salts of ion and the like.

Examples of the pH adjuster include various amines, inorganic bases, ammonia, and various buffer solutions.

Examples of UV absorbers include benzotriazole UV absorbers having ethylenically unsaturated bonds, benzophenone UV absorbers, salicylic acid UV absorbers, cyanoacrylate UV absorbers, hindered phenol UV absorbers, and triazine. Examples include ultraviolet absorbers.

Examples of the flame retardant include phosphorus flame retardants, phosphate ester flame retardants, boron flame retardants, and bromine flame retardants.

Examples of the antioxidant include phenolic antioxidants, amine antioxidants, dithiocarbamic acid antioxidants, and the like.

Although not particularly limited, in one embodiment, the combination of printing inks of each color in the printing ink set includes yellow ink containing the isoindoline compound represented by formula (1) and a dispersion medium; copper phthalocyanine as described above; C. C., a metal phthalocyanine pigment containing at least one selected from the group consisting of aluminum phthalocyanine, and titanyl phthalocyanine, and a dispersion medium; I. Magenta ink A containing pigment red 122 and a dispersion medium; and C. I. The magenta ink B may include pigment violet 19 and a dispersion medium.
In other embodiments, the combination of printing inks of each color is C.I. I. Yellow ink containing Pigment Yellow 180 and a dispersion medium; Cyan ink containing a dispersion medium and a metal phthalocyanine pigment containing at least one selected from the group consisting of copper phthalocyanine, aluminum phthalocyanine, and titanyl phthalocyanine as described above; C ．． I. Magenta ink A containing pigment red 122 and a dispersion medium; and C. I. The magenta ink B may include pigment violet 19 and a dispersion medium.
In these embodiments, the metal phthalocyanine pigment in the cyan ink is more preferably a copper phthalocyanine.
According to the combination of pigments (coloring materials) in each of these printing inks, it is possible to easily achieve both excellent light resistance and excellent color reproducibility. Further, in particular, as an effect of the combination of magenta ink A and magenta ink B, improvement in the adhesion of the printing layer (ink film) can be mentioned. In the above embodiment, when a polyurethane resin is used as the dispersion medium, it becomes easy to improve the adhesiveness of the printing layer (ink film). Further, when polybutylvinyral is used in addition to the polyurethane resin as the dispersion medium, it tends to be easier to further improve the adhesiveness.

<Manufacture of printing ink>
The printing ink constituting the printing ink set of this embodiment can be manufactured by dispersing pigment in a dispersion medium. Thereafter, a printing ink can be manufactured by blending additives, water, and/or an organic solvent, etc. with the obtained dispersion, if necessary.

As the disperser, commonly used ones can be used. Examples include roller mills, ball mills, pebble mills, attritor mills, sand mills, and other bead mills. Among these, use of a bead mill is preferred. The particle size distribution of the pigment in the pigment dispersion can be adjusted by appropriately adjusting the size of the media beads of the dispersion machine, the filling rate of the media beads, the dispersion time, the flow rate of the pigment dispersion, the viscosity of the pigment dispersion, etc. I can do it.

The printing ink set of this embodiment is preferably in the form of a gravure printing ink set or a flexographic printing ink set. Preferred forms of printing ink constituting these printing ink sets include gravure ink, water-based flexo ink, flexo ink, and active energy ray-curable flexo ink. Hereinafter, these various inks will be specifically explained.

<Gravure ink>
The gravure ink preferably contains a pigment and a binder resin as a dispersion medium, and further contains an organic solvent.

(pigment)
The content of pigment in the gravure ink is not particularly limited, but is preferably 4 to 20% by mass, more preferably 5 to 15% by mass.

(binder resin)
Examples of the binder resin include polyurethane resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, nitrocellulose resin, polyamide resin, polyvinyl acetal resin, cellulose ester resin, polystyrene resin, acrylic resin, polyester resin, alkyd resin, and rosin. Examples include resins such as rosin-modified maleic acid resins, ketone resins, cyclized rubbers, butyral resins, petroleum resins, and chlorinated polyolefin resins.

The content of the binder resin in the gravure ink is preferably 4 to 25% by mass, more preferably 6 to 20% by mass.

[Polyurethane resin]
The binder resin used in the gravure ink is preferably a polyurethane resin. Note that the polyurethane resin includes polyurethane urea resin.
Synthesis of polyurethane resin is, for example,
(1) A urethane prepolymer having isocyanate groups at its terminals is synthesized by reacting a polyol and a diisocyanate compound in a proportion in which isocyanate groups are in excess. A two-step method in which a urethane prepolymer having an isocyanate group is then reacted with a chain extender and/or an end-capping agent having an amino group in a solvent to synthesize the urethane prepolymer;
(2) A one-step method in which polypropylene glycol, polyol, diisocyanate compound, and a chain extender and/or terminal blocking agent having an amino group are reacted all at once in an appropriate solvent.
Solvents used for synthesis include, for example, ester solvents such as ethyl acetate, propyl acetate, and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; alcohol solvents such as methanol, ethanol, isopropanol, and n-butanol. ; Hydrocarbon solvents such as methylcyclohexane and ethylcyclohexane; or mixed solvents thereof;
Among these methods, the two-stage method is preferred from the viewpoint of obtaining a more uniform polyurethane resin. When producing a polyurethane resin by a two-step process, the equivalent ratio of the isocyanate groups of the urethane prepolymer to the amino groups of the chain extender and end-blocking agent (moles of isocyanate groups/moles of amino groups) is 1/1. 3 to 1/0.9 is preferable. When the equivalent ratio of isocyanate groups to amino groups is 1/1.3 or more, the amount of chain extenders and/or terminal blocking agents remaining unreacted is reduced, and yellowing of the polyurethane resin and odor after printing are reduced. Can be suppressed. When the equivalent ratio of isocyanate groups to amino groups is 1/0.9 or less, the resulting polyurethane resin has an appropriate molecular weight, and a resin that provides suitable film strength after printing can be obtained.

The weight average molecular weight of the polyurethane resin is preferably in the range of 15,000 to 100,000. When the weight average molecular weight of the polyurethane resin is 15,000 or more, the blocking resistance of the ink, the strength of the printed film, and the oil resistance are excellent, and when it is 100,000 or less, the viscosity of the obtained ink is within an appropriate range. , excellent gloss of printed film.

Further, the polyurethane resin preferably has an amine value from the viewpoint of printability and lamination strength. The amine value is preferably 0.5 to 20 mgKOH/g, more preferably 1 to 15 mgKOH/g.

In one embodiment, when the printing ink set of this embodiment is used as a packaging material, the content of the polyurethane resin is preferably 80% by mass or more based on the binder resin in the ink. By setting the content of the polyurethane resin within the above range, boil retortability and adhesion to polyester films can be easily improved.

[Polyvinyl butyral resin]
In one embodiment, the binder resin used in the gravure ink preferably further contains polyvinyl butyral resin. According to such embodiments, it tends to be easier to increase the adhesion of the ink film to the substrate.
Polyvinyl butyral resin can be obtained by reacting polyvinyl alcohol with butyraldehyde or formaldehyde to acetalize it.

The acetyl group content in the polyvinyl butyral resin is preferably 4% by mass or less. Further, the hydroxyl group content is preferably 1% by mass to 30% by mass, more preferably 1% by mass to 25% by mass. The weight average molecular weight of the polyvinyl butyral resin is preferably 10,000 to 50,000.

The content of polyvinyl butyral resin is preferably in the range of 1.0 to 15.0% by mass based on the binder resin in the ink. By setting the content of polyvinyl butyral resin in the binder resin to 1.0% by mass or more, the blocking resistance of the resulting printing ink and the adhesion to the polyester film can be easily improved. Further, by controlling the content to 15.0% by mass or less, the storage stability of the ink can be easily improved.

[Organic solvent]
Examples of organic solvents used in gravure ink include aromatic organic solvents such as toluene and xylene; ketone organic solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethyl acetate, n-propyl acetate, butyl acetate, and propylene glycol monomethyl ether. Ester organic solvents such as acetate; Alcohol organic solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol; Glycol ether solvents such as ethylene glycol monopropyl ether and propylene glycol monomethyl ether; Fats such as cyclomethylhexane group organic solvents; and the like. It is preferable to use a mixture of two or more of these organic solvents.
In gravure ink, it is preferable to use a mixed solvent of an ester organic solvent and an alcohol organic solvent. The mass ratio of the ester organic solvent to the alcohol organic solvent (mass of the ester organic solvent:mass of the alcohol organic solvent) is preferably 95:5 to 40:60, more preferably 90:10 to 50. :50.
The content of the organic solvent in the ink is preferably 60 to 90% by mass, more preferably 70 to 85% by mass, based on the mass of the ink.

The viscosity of the gravure ink may preferably be 10 mPa·s or more from the viewpoint of preventing pigment sedimentation and appropriately dispersing the pigment. On the other hand, from the viewpoint of work efficiency during ink production or printing, the viscosity of the gravure ink may preferably be 1,000 mPa·s or less. The above viscosity is a value measured at 25° C. using a B-type viscometer manufactured by Tokimec.

[water]
In one embodiment, the gravure ink can further include water. By including a predetermined amount of water, the pigment dispersibility by the polyurethane resin is improved, and printability such as highlight transfer property, plate fogging property, and trapping property is improved.
The content of water is preferably 0.1 to 10% by mass, more preferably 0.5 to 7% by mass, even more preferably 0.5 to 5% by mass, based on the mass of the gravure ink. The content is particularly preferably 0.5 to 4% by mass.

[Silica particles]
In one embodiment, the gravure ink can further contain silica particles. Including silica particles promotes ink wetting and spreading during overprinting, improves trapping properties, and maintains highlight transfer properties.
Silica particles may be either naturally occurring or synthetic. Moreover, it may be crystalline, non-crystalline, hydrophobic, or hydrophilic. There are two methods for synthesizing silica particles: a dry method and a wet method. Combustion methods and arc methods are known as dry methods, and precipitation methods and gel methods are known as wet methods, and the composition may be synthesized by either method. Further, the silica particles may be hydrophilic silica having a hydrophilic functional group on the surface. Alternatively, the silica particles may be hydrophobic silica obtained by modifying a hydrophilic functional group with an alkylsilane or the like to make it hydrophobic. Hydrophilic silica is preferred.
Such silica particles can also be obtained as commercial products. Examples include the Nipgel series and Nipsil series manufactured by Tosoh Silica Co., Ltd., and the Mizukasil series manufactured by Mizusawa Chemical Co., Ltd.

The average particle diameter of the silica particles is preferably 1 to 10 μm in order to create irregularities on the surface of the ink layer. More preferably 1 to 8 μm, still more preferably 1 to 6 μm. The average particle diameter of silica particles means the particle diameter at 50% integrated value (D ₅₀ ) in the particle size distribution, and can be determined by the Coulter counter method.
The specific surface area of the silica particles is preferably 50 to 600 m ² /g by the BET method. More preferably, it is 100 to 450 m ² /g. The silica particles used in the gravure ink can be a combination of two or more types having different average particle diameters or BET specific surface areas.

The content of silica particles in the gravure ink is preferably 0.1 to 3% by mass, more preferably 0.2 to 2.5% by mass, and even more preferably 0.2 to 2% by mass. , particularly preferably 0.2 to 1.5% by mass.

[Other ingredients]
In addition to the above components, the gravure ink may further contain other components such as various additives, if necessary. Other ingredients include extender pigments, pigment dispersants, waxes, antiblocking agents, leveling agents, antifoaming agents, plasticizers, antistatic agents, infrared absorbers, ultraviolet absorbers, fragrances, and flame retardants. Various additives may be mentioned. If necessary, these various additives may be further added to the ink.

<Gravure printing method and printed matter>
Gravure printing can be appropriately selected from known methods. That is, a gravure printing machine capable of printing in multiple colors is used, which is equipped with a rotating intaglio plate (gravure plate) and a doctor blade in contact therewith, and gravure ink is supplied from an ink container (ink pan). A dedicated viscosity controller may be used to adjust the viscosity. Further, the substrate for printing is supplied in a roll-up manner, and the printed matter passes through a drying unit after printing. The temperature of the drying unit is preferably 30 to 100°C. Further, the printing speed is preferably 50 to 250 m/min.

Gravure printing methods are broadly divided into front printing and back printing. For example, in surface printing, if the base material is white paper or white film, printed matter can be obtained by printing yellow ink, magenta ink, cyan ink, and black ink on the base material in this order. .
For example, in back printing, when the base material is a transparent film, it is preferable to print black ink, cyan ink, magenta ink, yellow ink, and white ink on the base material in this order to produce printed matter. .
The thickness of the printing layer can be appropriately selected depending on the purpose, the type and number of inks used, and the number of times of overprinting. In one embodiment, the thickness of the printed layer may typically range from 0.5 to 10 μm.

[Base material]
The base material is, for example, a polyolefin base material such as polyethylene or polypropylene; a polycarbonate base material; a polyester base material such as polyethylene terephthalate or polylactic acid; a polystyrene base material; a polystyrene resin base material such as AS or ABS; a polyamide base material such as nylon. material; polyvinyl chloride base material; polyvinylidene chloride base material; cellophane base material; paper base material; aluminum foil base material; and composite base material made of composite materials thereof. The base material may be in the form of a film or a sheet. Among these, polyester base materials and polyamide base materials, which have a high glass transition temperature, are preferably used.

The surface of the base material may be vapor-deposited with a metal oxide or the like, or coated with polyvinyl alcohol or the like. Examples of substrates that have undergone such surface treatment include GL-AE manufactured by Toppan Printing Co., Ltd. and IB-PET-PXB manufactured by Dainippon Printing Co., Ltd., which have aluminum oxide deposited on their surfaces. The base material may be treated with additives such as an antistatic agent and an ultraviolet inhibitor, and may be subjected to corona treatment or low-temperature plasma treatment, if necessary.

The thickness of the base material is not particularly limited and may generally be in the range of 5 to 100 μm.

<Water-based flexo ink>
The water-based flexographic ink contains at least a pigment, a binder resin, and an aqueous solvent as a dispersion medium.

The content of the pigment composition in the aqueous flexographic ink is not particularly limited, but is preferably 10 to 30% by mass, more preferably 15 to 25% by mass.

Each component contained in the water-based flexographic ink will be explained below.

[Binder resin]
Preferably, the water-based flexographic ink contains a binder resin. Examples of the binder resin include water-based polyurethane resin, water-based acrylic urethane resin, polyester resin, acrylic resin, styrene-acrylic resin, styrene-maleic anhydride resin, rosin-modified maleic resin, cellulose resin, and chlorinated polyolefin. Examples include water-based resins. Among these, it is preferable to contain at least an aqueous polyurethane resin. Binder resins can be used alone or in combination of two or more types.

(Water-based polyurethane resin)
A polyurethane resin is generally a resin obtained by reacting a polyisocyanate having two or more isocyanate groups in one molecule with a hydroxyl group-containing compound having two or more hydroxyl groups in one molecule. In one embodiment, the water-based polyurethane resin has the configuration described below. Such a configuration can be preferably introduced by appropriately selecting the structure, type, etc. of the hydroxyl group-containing compound.

The number of urethane bonds (mmol/g) in the aqueous polyurethane resin is not particularly limited. In one embodiment, from the viewpoint of adjusting the molecular weight of the water-based polyurethane resin and the hardness of the coating film, the number of urethane bonds is preferably 2.2 to 3.0 mmol/g, and 2.3 to 2.9 mmol/g. More preferred. The number of urethane bonds can be adjusted to a desired range by appropriately adjusting the amounts of the hydroxyl group-containing compound and polyisocyanate, and the reaction conditions.

The glass transition temperature (Tg) of the aqueous polyurethane resin is not particularly limited, but is preferably -70°C or lower, more preferably -70°C to -90°C. When the Tg of the aqueous polyurethane resin is −70° C. or less, the film forming properties of the ink are improved and the adhesion of the coating film is improved.

The weight average molecular weight (GPC measurement, standard polystyrene equivalent) of the aqueous polyurethane resin is not particularly limited, but is preferably from 10,000 to 100,000, more preferably from 30,000 to 70,000.

The hydroxyl value (mgKOH/g) of the aqueous polyurethane resin is not particularly limited, but from the viewpoint of water resistance etc., it is preferably 35 mgKOH/g or less, and more preferably 20 mgKOH/g or less. In one embodiment, the hydroxyl value (mgKOH/g) may be 0 mgKOH/g.

The water-based polyurethane resin may be water-soluble or may be a water-based emulsion, but is preferably water-soluble. Here, the aqueous emulsion refers to a resin solution in which a resin hardly soluble in water is stabilized in the form of emulsion in the form of particles.
The content of the aqueous polyurethane resin is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more, based on the total mass of the aqueous flexographic ink. On the other hand, the content of the water-based polyurethane resin is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 17% by mass or less, based on the total mass of the water-based flexographic ink.

(Polyvinyl butyral resin)
In one embodiment, the binder resin used in the water-based flexographic ink preferably further includes a polyvinyl butyral resin. According to such embodiments, it tends to be easier to increase the adhesion of the ink film to the substrate. As the polyvinyl butyral resin, the polyvinyl butyral resin described in the description of the gravure ink above is preferable.

[Aqueous solvent]
Water-based flexographic inks contain an aqueous solvent. Aqueous solvents include water; alcohol solvents such as n-propanol and isopropanol; glycol solvents such as propylene glycol, butylene glycol, dipropylene glycol, and tripropylene glycol; glycol monoalkyl such as propylene glycol monoethyl ether and propylene glycol monopropyl ether. Examples include ether solvent; etc.

The content of the aqueous solvent is preferably 40 to 70% by mass based on the total mass of the aqueous flexo ink.

[Other ingredients]
The water-based flexographic ink may further contain other components such as various additives in addition to the above components, as necessary. Other ingredients include extender pigments, pigment dispersants, waxes, leveling agents, surfactants, antifoaming agents, preservatives, thickeners, pH adjusters, curing agents, and various known additives such as ultraviolet absorbers. Can be mentioned. If necessary, these various additives may be further added to the ink. Furthermore, non-aqueous solvents other than alcohol solvents (for example, ketone solvents and ester solvents) may be added as long as the problem can be solved. The content of the non-aqueous solvent is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total mass of the ink.

<Flexo printing method and printed matter>
The method of flexographic printing is not particularly limited, and can be appropriately selected from known methods. Examples include a two-roll system, a doctor system, a doctor chamber system, and the like. In the doctor method and doctor chamber method, flexo ink is supplied to an anilox roll with cells formed on its surface, the excess flexo ink on the surface of the anilox roll is scraped off with a doctor blade, and then passed through a resin plate and finally printed as a base. Ink is printed (applied) onto the material.

As the anilox used for flexographic printing, a ceramic anilox roll with cell engraving, a chrome-plated anilox roll, etc. can be used. Cell shapes include honeycomb patterns, diamond patterns, helical patterns, etc., and any of these patterns can be used.

Plates used for flexographic printing include photosensitive resin plates that utilize ultraviolet curing by a UV light source and elastomer material plates that use a direct laser engraving method. Any sleeve and cushion tape can be used to attach the plate.

Examples of flexo printing machines include CI type multicolor flexo printing machines and unit type multicolor flexo printing machines. Examples of ink supply methods include a chamber method and a two-roll method. A printing machine combining these as appropriate can be used.

[Base material]
Examples of the base material include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and nylon, cellophane, paper, aluminum foil, and films and sheets made of composite materials thereof. The paper base material is preferably a paper base material selected from uncoated paper, single-gloss kraft paper treated on one side of the base material, bleached kraft paper, unbleached kraft paper, and the like. Other base materials such as plastic films can be the same as those used for gravure ink prints.

<Flexo ink>
The flexo ink preferably contains a pigment and a binder resin as a dispersion medium, and further contains an organic solvent.

(pigment)
The content of pigment in the flexographic ink is not particularly limited, but is preferably 4 to 25% by mass, more preferably 5 to 20% by mass.

(binder resin)
Examples of the binder resin include polyurethane resin, polyvinyl acetal resin, cellulose ester resin, polyamide resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, polystyrene resin, acrylic resin, polyester resin, alkyd resin, rosin resin, and rosin resin. Examples include modified maleic acid resins, ketone resins, cyclized rubbers, butyral resins, petroleum resins, and chlorinated polyolefin resins.
Among these, the binder resin preferably includes polyurethane resin, polyvinyl acetal resin, and cellulose ester resin.

As the polyurethane resin and polyvinyl acetal resin, the polyurethane resin and polyvinyl acetal resin described in the description of the gravure ink above are preferable.

As the cellulose ester resin, nitrocellulose resin, cellulose acetate propionate resin, or cellulose acetate butyrate resin is preferable.

Nitrocellulose resin is obtained by nitrifying some or most of the hydroxyl groups of cellulose with a mixed acid of sulfuric acid and nitric acid. The solubility of nitrocellulose resin in solvents changes depending on the degree of nitrification. Usually, those with a high degree of nitrification are used for hydrocarbon solvents or ester solvents. Also, those with a low degree of nitrification are used as alcohol-based solvents.

Cellulose acetate propionate resin is obtained by triesterifying cellulose with acetic acid and propionic acid and then hydrolyzing it. Generally, resins containing 0.6 to 2.5 mass % of acetylation, 42 to 46 mass % of propionation, and 1.8 to 5 mass % of hydroxyl groups are commercially available. In one embodiment of the present invention, from the viewpoint of compatibility with polyurethane resin, the propionyl group content is 40 to 50% by mass (center value 45%), and the acetyl group content is 0.5 to 3% by mass (center value 2.5%), a hydroxyl group content of 2 to 6% by mass (median value 2.5%), and a viscosity of 0.05 to 0.2 Pa·s.

Cellulose acetate butyrate resin is obtained by triesterifying cellulose with acetic acid and butyric acid and then hydrolyzing it. Generally, resins containing 2 to 30% by weight of acetylation, 17 to 53% by weight of butyrylation, and 1 to 5% by weight of hydroxyl groups are commercially available.

[Organic solvent]
Organic solvents used for flexo ink include, for example, ester-based organic solvents such as ethyl acetate, n-propyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate; alcohol-based solvents such as methanol, ethanol, n-propanol, isopropanol, and n-butanol. Organic solvents; glycol ether solvents such as ethylene glycol monopropyl ether and propylene glycol monomethyl ether; aliphatic organic solvents such as cyclomethylhexane; and the like. It is preferable to use a mixture of two or more of these organic solvents.

[Other ingredients]
The flexo ink may contain other components such as various additives in addition to the above components, as necessary. Other ingredients include various additives such as extender pigments, pigment dispersants, waxes, antiblocking agents, leveling agents, antifoaming agents, plasticizers, antistatic agents, infrared absorbers, ultraviolet absorbers, fragrances, and flame retardants. Examples include agents. If necessary, these various additives may be further added to the ink.

<Active energy ray curable flexo ink>
The active energy ray-curable flexo ink contains a pigment, a polymerizable compound as a dispersion medium, and a photopolymerization initiator.

The content of the pigment composition in the active energy ray-curable flexographic ink is not particularly limited, but is preferably from 5 to 30% by mass, more preferably from 10 to 25% by mass.

The components described below are included in the active energy ray-curable flexo ink of this embodiment, or added to the ink as necessary.

[Polymerizable compound]
The polymerizable compound is as described above.

The polymerizable compounds can be used alone or in combination of two or more.

The content of the polymerizable compound is preferably 25 to 90% by mass, more preferably 35 to 80% by mass, based on the total mass of the active energy ray-curable flexographic ink.

[Polymerization initiator]
The active energy ray-curable flexo ink contains a polymerization initiator. The polymerization initiator preferably includes a radical polymerization initiator, and more preferably a photopolymerization initiator. A polymerization initiator is a compound that undergoes a chemical change and generates radicals through the action of light or interaction with the electronically excited state of a sensitizing dye. Among these, photoradical polymerization initiators are preferred because polymerization can be initiated by exposure.

The photoradical polymerization initiator is not particularly limited, and any known one can be used. Specific examples include benzophenone compounds, dialkoxyacetophenone compounds, α-hydroxyalkylphenone compounds, α-aminoalkylphenone compounds, acylphosphine oxide compounds, and thioxanthone compounds.

Examples of the benzophenone compounds include benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, [4-(methylphenylthio) phenyl]-phenylmethanone and the like.

Examples of the dialkoxyacetophenone compounds include 2,2-dimethoxy-2-phenylacetophenone, dimethoxyacetophenone, and diethoxyacetophenone.

The above α-hydroxyalkylphenone compounds include 1-hydroxy-cyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxymethoxy)-phenyl ]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl -propan-1-one and the like.

The above α-aminoalkylphenone compounds include 2-methyl-1-[4-(methoxythio)-phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-(dimethylamino)-1- (4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, etc. It will be done.

Examples of the above acylphosphine oxide compounds include diphenylacyl phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, etc. It will be done.

Examples of the thioxanthone compounds include 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, and 2,4-diethylthioxanthone.

The above polymerization initiators can be used alone or in combination of two or more.

The content of the polymerization initiator is preferably 0.5 to 20% by mass, more preferably 5 to 15% by mass, based on the total mass of the active energy ray-curable flexographic ink.

[Dispersant]
The active energy ray-curable flexographic ink preferably further contains a dispersant in order to further improve pigment dispersibility. There are no particular limitations on the dispersant, and any known dispersant can be used.
Specific examples include polymeric dispersants containing polyoxyalkylene polyalkylene polyamines, vinyl polymers and copolymers, acrylic polymers and copolymers, polyesters, polyamides, polyimides, polyurethanes, amine polymers, and the like as main components. Among these, from the viewpoint of pigment dispersion stability, pigment dispersants containing basic functional groups having a block structure or a comb structure are preferred.
Such pigment dispersants can also be obtained as commercial products. For example, the Ajisper series (Ajisper PB821, PB822, PB824, etc.) manufactured by Ajinomoto Fine-Techno Co., Ltd., the Solspers series (SOLSPERSE24000, SOLSPERSE32000, SOLSPERSE38500, SOLSPERSE39000, etc.) manufactured by Japan Lubrizol, Inc., and the Disperbic manufactured by Bic Chemie, Inc. Series ( BYK-162, BYK-168, BYK-183, etc.).

The content of the dispersant is preferably 0.1 to 10% by mass based on the total mass of the active energy ray-curable flexographic ink.

[Polymerization initiation aid]
The active energy ray-curable flexo ink can also contain a polymerization initiation aid. By containing a polymerization initiation aid, curability can be further improved. Examples of polymerization initiation aids include triethanolamine, methyldiethanolamine, triisopropanolamine, aliphatic amines, ethyl 2-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, dibutylethanolamine, etc. can be mentioned.

The content of the polymerization initiation aid is preferably 0.1 to 5% by mass, more preferably 0.5 to 3% by mass, based on the total mass of the active energy ray-curable flexo ink.

[wax]
The active energy ray-curable flexographic ink preferably contains wax in order to further improve friction resistance, anti-blocking properties, slip properties, and anti-scratch properties. There are no particular restrictions on the wax, and any known wax can be used. For example, natural waxes and synthetic waxes. Examples of natural waxes include carnauba wax, Japanese wax, lanolin, montan wax, paraffin wax, and microcrystalline wax. Examples of synthetic waxes include Fischer-Tropsch wax, polyethylene wax, polypropylene wax, polytetrafluoroethylene wax, polyamide wax, and silicone compounds.

The content of the above-mentioned wax is preferably 0.1 to 5% by mass, and 0.5% by mass based on the total mass of the active energy ray-curable flexo ink, from the viewpoint of the balance of abrasion resistance, gloss, and piling. More preferably, it is 4% by mass.

[Binder resin]
The active energy ray-curable flexo ink may contain a binder resin. By including the binder resin, curing shrinkage of the coating film that occurs during curing is alleviated, curling of the substrate is suppressed, and adhesion to the substrate is improved.

Binder resins include polyvinyl chloride, poly(meth)acrylic acid ester, epoxy resin, polyester resin, polyurethane resin, cellulose derivatives (for example, ethyl cellulose, cellulose acetate, nitrocellulose), vinyl chloride-vinyl acetate copolymer, polyamide Examples include resins, polyvinyl acetal resins, diallyl phthalate resins, alkyd resins, rosin-modified alkyd resins, rosin-modified alkyd resins, petroleum resins, urea resins, and synthetic rubbers such as butadiene-acrylonitrile copolymers. Among these, diallyl phthalate resin and polyester resin are preferred. More preferred is diallyl phthalate resin.

The weight average molecular weight of the binder resin is preferably 1,000 to 100,000. More preferably, it is 2,000 to 70,000.

The above binder resins can be used alone or in combination of two or more kinds. Further, from the viewpoint of curability, the content of the binder resin is preferably 1 to 15% by mass based on the total mass of the active energy ray-curable flexographic ink. More preferably, it is 1 to 5% by mass.

[Polymerization inhibitor]
The active energy ray-curable flexographic ink may contain a polymerization inhibitor. Examples of the polymerization inhibitor include 4-methoxyphenol, hydroquinone, methylhydroquinone, t-butylhydroquinone, 2,6-di-t-butyl-4-methylphenol, phenothiazine, and aluminum salt of N-nitrosophenylhydroxylamine. Can be mentioned.

The content of the polymerization inhibitor is 0.01 to 0.01 to the total mass of the active energy ray curable flexographic ink, from the viewpoint of maintaining curability and increasing the storage stability of the active energy ray curable flexographic ink. 2% by mass is preferred.

[Other ingredients]
The active energy ray-curable flexographic ink may contain various additives in addition to the above-mentioned components, as necessary, within a range that does not reduce the effects of the present invention. Various additives such as extender pigments, leveling agents, surfactants, antifoaming agents, ultraviolet absorbers, antistatic agents, and antioxidants can be added to the ink as necessary.

In addition, it is preferable that the active energy ray-curable flexo ink does not substantially contain water. "Substantially free" means 1% by mass or less based on the total mass of the ink composition.

<Printing method and printed matter of active energy ray-curable flexographic ink>
The active energy ray-curable flexographic ink can be printed on a recording medium using a flexographic printing method and then cured with active energy rays to form a printed matter. The recording medium is not particularly limited, and any known medium can be used. Specifically, coated paper such as art paper, coated paper, and cast paper, uncoated paper such as high-quality paper, medium-quality paper, and newsprint, synthetic paper such as Yupo paper, PET (polyethylene terephthalate), PP ( Examples include plastic films such as polypropylene) and OPP (biaxially oriented polypropylene).

There are no particular limitations on the method for curing the active energy ray-curable flexographic ink, and any known method can be used. For example, the ink can be cured by irradiating with alpha rays, gamma rays, electron beams, X-rays, ultraviolet rays, visible light, infrared light, or the like. Among these, ultraviolet rays and electron beams are preferable, and ultraviolet rays are more preferable. The peak wavelength of the active energy ray is preferably 200 to 600 nm, more preferably 350 to 420 nm.

There are no particular restrictions on the active energy ray source, and known sources can be used. Specific examples include LEDs (light emitting diodes) such as mercury lamps, xenon lamps, metal hydride lamps, ultraviolet light emitting diodes (UV-LEDs), and ultraviolet laser diodes (UV-LD), gas and solid-state lasers, and the like. Among these, ultraviolet light emitting diodes (UV-LEDs) are preferred because they are small, long-life, highly efficient, and low-cost.

<Packaging materials>
One embodiment of the present invention relates to packaging materials. The packaging material includes printed matter on at least a portion thereof. Prints on packaging materials are formed using the printing ink set of the above embodiments according to various printing methods, as explained above.
In one embodiment, the packaging material can be used in the form of a printed product itself, with a printed layer formed on a substrate. Examples of such packaging materials include stickers, labels, and the like. In other embodiments, the packaging material may have a laminated structure in which, for example, at least a printed matter, an adhesive layer, and a sealant substrate are sequentially laminated. A package can be obtained by processing a packaging material having such a laminated structure.
Examples of the package include a four-side seal package, a three-side seal package, a pillow package, a stick bag, a gusset bag, a square bottom bag, a standing pouch, a deep-drawn container, a vacuum package, a skin pack, a zipper bag, a spout pouch, Examples include twist packaging, wrap packaging, shrink packaging, labels, liquid paper packs, and paper trays. In one embodiment, the packaging material can be suitably used for packages having various shapes.

Items to be packaged with packaging materials include, for example, foodstuffs (e.g., rice, confectionery, seasonings, edible oils and fats, cooked foods, etc.), beverages (e.g., alcoholic beverages, soft drinks, mineral water, etc.), daily necessities, and culture. Examples include supplies (for example, pharmaceuticals, cosmetics, stationery, etc.), electronic parts, and the like.

Hereinafter, the packaging material having the above laminated structure will be explained in more detail. [Adhesive layer]
In the above packaging material having a laminated structure, adhesive components that can be used to form the adhesive layer include laminating adhesives, hot melt adhesives, and thermoplastic resins. Among the above adhesive components, laminating adhesives and hot melt adhesives include, for example, polyether adhesives; polyurethane adhesives; epoxy adhesives; polyvinyl acetate adhesives; cellulose adhesives; (meth) Examples include acrylic adhesives. Among these adhesive components, polyurethane adhesives are preferably used.

The adhesive components can be used alone or in combination of two or more.

The polyurethane adhesive is a reactive adhesive containing polyol and polyisocyanate, and may have removability. Examples of the polyurethane adhesive having removability include the laminate adhesive described in JP-A-2020-084130.
The polyurethane adhesive having such releasability preferably has an acid value of 5 to 45 mgKOH/g. Further, it is preferable that the polyol constituting the polyurethane adhesive contains a polyester polyol, and the polyisocyanate contains one selected from the group consisting of aliphatic polyisocyanates and araliphatic polyisocyanates.
The thickness of the adhesive layer may typically range from 1 to 6 μm.

[Sealant base material]
In the packaging material having the laminated structure described above, the sealant base material is a base material that constitutes the innermost layer of the laminate film. As the sealant base material, a resin material that can be mutually fused by heat (has heat-sealing properties) is used. Examples of the sealant base material include unstretched polypropylene (CPP), vapor-deposited unstretched polypropylene film (VMCPP), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ethylene vinyl acetate copolymer (EVA), etc. can be mentioned.
The thickness of the sealant base material is not particularly limited. Considering processability into packaging materials, heat sealability, etc., the above thickness is preferably in the range of 10 to 200 μm, more preferably in the range of 15 to 150 μm. Further, by providing the sealant base material with unevenness having a height difference of 5 to 20 μm, it is possible to impart properties such as slipperiness and tearability of the packaging material to the sealant base material.
Moreover, the method of laminating the sealant base materials is not particularly limited. For example, a method in which an adhesive layer and a sealant base film are laminated by heat (thermal lamination, dry lamination), or a method in which a sealant base resin is melted, extruded onto the adhesive layer, cooled and solidified, and then laminated ( extrusion lamination method), etc.

Conventional printing inks used in packaging materials may not have sufficient lightfastness to various light sources. Therefore, deterioration in design quality such as fading may occur. Further, under the influence of radicals generated by light irradiation during storage, the cohesive force or adhesion of the printed layer may decrease, and the laminate strength may decrease. As a result, when unsealing packages and packaging materials that have been stored for a long period of time under light irradiation, a problem may arise in which interphase delamination of the laminate occurs. In contrast, the packaging material of this embodiment can maintain high design quality because the printing ink set has excellent color reproducibility. In addition, the printing layer formed using the printing ink set has excellent light resistance and adhesion, which prevents problems such as delamination that occur with conventional packaging materials. be able to. From this point of view, in one embodiment, the printing ink set of the above embodiment can be suitably used for packaging materials having a laminated structure. According to such an embodiment, a packaging material with high lamination strength can be easily provided.

Hereinafter, embodiments of the present invention will be described in detail using Examples, but the embodiments of the present invention are not limited to the following Examples. Note that "part" means "part by mass" and "%" means "% by mass."
Further, the blending amounts in the table are parts by mass, and values other than the solvent are nonvolatile content equivalent values. In addition, a blank column in the table indicates that it is not blended.

(Average primary particle size of pigment)
The average primary particle diameter of the pigment was measured by directly measuring the size of the primary particles from an electron micrograph using a transmission electron microscope (TEM). Specifically, the minor axis diameter and major axis diameter of each primary pigment particle were measured, and the average was taken as the particle diameter of the primary pigment particle. Next, the volumes of 100 or more pigment particles were determined by approximating the respective determined particle diameters to a cube, and the volume average particle diameter was defined as the average primary particle diameter.

<Production of isoindoline compound>
(Manufacturing example 1-1)
(Step 1)
800 parts of water, 60 parts of 1,3-diiminoisoindoline, and 120 parts of 28% aqueous ammonia were added in this order to a four-neck flask equipped with a reflux condenser, a dropping funnel, and a stirrer, and the mixture was stirred. A solution of 42.58 parts of 2-cyano-N-methylacetamide dissolved in 160 parts of water was added dropwise thereto over 30 minutes using a dropping funnel. The mixture was heated and stirred at 30° C. until the raw material 1,3-diiminoisoindoline disappeared. The reaction slurry was filtered using a Buchner funnel. Further, the filtrate was added to 1,600 parts of water and stirred at 40°C for 30 minutes to remove unreacted 2-cyano-N-methylacetamide. The slurry was filtered to obtain non-volatile components. The disappearance of 1,3-diiminoisoindoline was confirmed by UPLC (ultra high performance high separation liquid chromatography manufactured by Waters).
(Step 2)
Into a four-necked flask equipped with a reflux condenser, a dropping funnel, and a stirrer, 60 parts of the above nonvolatile matter and 480 parts of water were added and stirred. On the other hand, 461 parts of water, 194 parts of 80% acetic acid, and 35.67 parts of barbituric acid were added to a glass flask, and the mixture was stirred at 65°C. The heated solution of this mixture was poured into the above-mentioned stirring liquid of non-volatile components, and the temperature was raised to 85° C. and stirring was performed to further complete the reaction. The heating and stirring were continued until the nonvolatile components used as raw materials disappeared. Disappearance of the raw material was confirmed by UPLC.
Thereafter, the slurry was filtered and washed three times with 2400 parts of water to obtain non-volatile components. This nonvolatile content was dried in a hot air dryer at 80° C. to obtain 89.45 parts of isoindoline compound (1-1).

(Production example 1-2)
The reaction operation was carried out in the same manner as in Production Example 1-1, except that in Step 2 of Production Example 1-1, 35.67 parts of barbituric acid was changed to 43.48 parts of 1,3-dimethylbarbituric acid. 92.05 parts of indoline compound (1-2) were obtained.

(Manufacturing example 1-3)
Production Example 1-1 except that in Step 2 of Production Example 1-1, 35.67 parts of barbituric acid was changed to 33.89 parts of barbituric acid and 2.17 parts of 1,3-dimethylbarbituric acid. A similar reaction operation was performed to obtain 85.34 parts of isoindoline compound (1-3).

(Production example 1-4)
(Step 1)
800 parts of water, 60 parts of 1,3-diiminoisoindoline, and 120 parts of 28% aqueous ammonia were added in this order to a four-neck flask equipped with a reflux condenser, a dropping funnel, and a stirrer, and the mixture was stirred. A solution of 42.58 parts of 2-cyano-N-methylacetamide dissolved in 160 parts of water was added dropwise thereto over 30 minutes using a dropping funnel. The mixture was heated and stirred at 30° C. until the raw material 1,3-diiminoisoindoline disappeared. The reaction slurry was filtered using a Buchner funnel. Further, the filtrate was added to 1,600 parts of water and stirred at 40°C for 30 minutes to remove unreacted 2-cyano-N-methylacetamide. The slurry was filtered to obtain non-volatile components. The disappearance of 1,3-diiminoisoindoline was confirmed by UPLC.
(Step 2)
Into a four-necked flask equipped with a reflux condenser, a dropping funnel, and a stirrer, 60 parts of the nonvolatile matter obtained in the previous preparation as raw materials, 480 parts of water, and 162 parts of 80% acetic acid were added and stirred. On the other hand, 480 parts of water and 162 parts of 80% acetic acid were added to a glass flask, and 33.89 parts of barbituric acid was added thereto, followed by stirring at 65°C. The heated solution of this mixture was poured into the above-mentioned stirring liquid of non-volatile components, and stirred at 30° C. for 3 hours. Furthermore, 48 parts of water and 16 parts of 80% acetic acid were added to a glass flask prepared separately, and 2.17 parts of 1,3-dimethylbarbituric acid was added thereto, followed by stirring at 65°C. The heated solution of this mixture was poured into the reaction stirring solution, and the temperature was raised to 85° C. and stirring was performed to further complete the reaction. The heating and stirring were continued until the nonvolatile components used as raw materials disappeared. In addition, disappearance of the raw material was confirmed by UPLC.
Thereafter, the slurry was filtered and washed three times with 2,400 parts of water to obtain nonvolatile components. This nonvolatile content was dried in a hot air dryer at 80°C to obtain 85.45 parts of isoindoline compound (1-4).

(Production example 1-5)
In Step 1 of Production Example 1-1, 42.58 parts of 2-cyano-N-methylacetamide was added to 40.45 parts of 2-cyano-N-methylacetamide and 1.82 parts of 2-cyano-acetamide, and in Step 2 The reaction operation was carried out in the same manner as in Production Example 1-1, except that the non-volatile content was changed from 60 parts equivalent to 59.81 parts equivalent, to obtain 84.81 parts of isoindoline compound (1-5).

(Manufacturing example 1-6)
In Step 1 of Production Example 1-1, 42.58 parts of 2-cyano-N-methylacetamide was added to 40.45 parts of 2-cyano-N-methylacetamide and 3.48 parts of 2-cyano-N-phenylacetamide. The reaction operation was carried out in the same manner as in Production Example 1-1, except that in Step 2, the nonvolatile content was changed from 60 parts equivalent to 60.82 parts, and 85.76 parts of isoindoline compound (1-6) was obtained.

(Production example 1-7)
In Step 1 of Production Example 1-1, 42.58 parts of 2-cyano-N-methylacetamide was added to 40.45 parts of 2-cyano-N-methylacetamide and 3.50 parts of phenyl cyanoacetate, and in Step 2, non-volatile The reaction operation was carried out in the same manner as in Production Example 1-1 except that the equivalent of 60 parts was changed to the equivalent of 60.84 parts, and 85.78 parts of isoindoline compound (1-7) was obtained.

(Production example 1-8)
In Step 1 of Production Example 1-1, 60 parts of 1,3-diiminoisoindoline was added to 57 parts of 1,3-diiminoisoindoline and 3.29 parts of 5-methyl-1,3-diiminoisoindoline. The reaction operation was carried out in the same manner as in Production Example 1-1, except that in Step 2, the nonvolatile content was changed from 60 parts equivalent to 60.19 parts, to obtain 85.16 parts of isoindoline compound (1-8).

(Production example 1-9)
In Step 1 of Production Example 1-1, 60 parts of 1,3-diiminoisoindoline was changed to 57 parts of 1,3-diiminoisoindoline and 3.62 parts of 5-methoxy-1,3-diiminoisoindoline. The reaction operation was carried out in the same manner as in Production Example 1-1, except that in Step 2, the non-volatile content was changed from 60 parts equivalent to 60.40 parts equivalent, to obtain 85.36 parts of isoindoline compound (1-9).

(Production example 1-10)
In Step 1 of Production Example 1-1, 60 parts of 1,3-diiminoisoindoline was replaced with 57 parts of 1,3-diiminoisoindoline and 3.62 parts of 4-methoxy-1,3-diiminoisoindoline. The reaction operation was carried out in the same manner as in Production Example 1-1, except that in Step 2, the nonvolatile content was changed from 60 parts equivalent to 60.40 parts, and 85.36 parts of isoindoline compound (1-10) was obtained.

(Production example 1-11)
Same as Production Example 1-1 except that in Step 2 of Production Example 1-1, 35.67 parts of barbituric acid was changed to 33.89 parts of barbituric acid and 1.98 parts of 1-methylbarbituric acid. The reaction operation was performed to obtain 85.16 parts of isoindoline compound (1-11).

(Production example 1-12)
Production Example 1-1 except that in Step 2 of Production Example 1-1, 35.67 parts of barbituric acid was changed to 33.89 parts of barbituric acid and 2.56 parts of 1,3-diethylbarbituric acid. A similar reaction operation was performed to obtain 85.34 parts of isoindoline compound (1-24).

Table 1 shows the structures contained in the isoindoline compounds obtained in Production Examples 1-1 to 1-12. In the table, H represents hydrogen, Me represents a methyl group, Et represents an ethyl group, Ph represents a phenyl group, and OMe represents a methoxy group.

The obtained isoindoline compound was identified by comparing the molecular ion peak of the mass spectrum with the mass number (theoretical value) obtained by calculation. The molecular ion peak of the mass spectrum was measured using Waters' ACQUITY UPLC BEH C18 Column 130 Å, 1.7 μm, 2.1 mm x 50 mm)/Ms TAP XEVO TQD. For the isoindoline compounds (Production Examples 1-1 to 1-12), the theoretical molecular weights and the respective measured values obtained by mass spectrometry are shown in Table 1. Due to the nature of the measurement, H (protons) from the compound are eliminated, so if the measured value is the mass number of the theoretical molecular weight - (minus) 1, the compounds match.

(Production example 1-13)
95 parts of isoindoline compound (1-1), 5 parts of isoindoline compound (1-2), 1000 parts of sodium chloride, and 150 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) and heated at 60°C. The mixture was kneaded for 8 hours. Next, the kneaded mixture is poured into warm water at about 70°C, stirred for 1 hour to form a slurry, repeatedly filtered and washed with water to remove sodium chloride and diethylene glycol, dried at 80°C overnight, and pulverized. 95 parts of isoindoline compound (1-13) were obtained.

(Manufacturing example 2-1)
800 parts of water and 800 parts of 80% acetic acid were added to a 4-necked flask equipped with a reflux condenser, a dropping funnel, and a stirrer, and the mixture was stirred. 111.18 parts of barbituric acid was added thereto, and the mixture was stirred at 65°C to dissolve the barbituric acid. Meanwhile, 800 parts of water and 60.00 parts of 1,3-diiminoisoindoline were added to a glass flask and stirred at 30°C. This stirred solution was poured into the heated solution, and the temperature was raised to 85° C. and stirred to complete the reaction. The heating and stirring were continued until the nonvolatile components used as raw materials disappeared. Disappearance of the raw material was confirmed by UPLC.
Thereafter, washing was performed three times with 2000 parts of water to obtain nonvolatile components. This nonvolatile content was dried in a hot air dryer at 80°C to obtain 133.59 parts of isoindoline compound (2-1).

(Manufacturing example 2-2)
The reaction operation was carried out in the same manner as in Production Example 2-1, except that 111.18 parts of barbituric acid in Production Example 2-1 was changed to 135.53 parts of 1,3-dimethylbarbituric acid, and the isoindoline compound (2- 154.00 parts of 2) were obtained.

Table 2 shows the structures contained in the isoindoline compounds obtained in Production Examples 2-1 and 2-2. In addition, in the table, H represents hydrogen and Me represents a methyl group.

The obtained isoindoline compound was identified by comparing the molecular ion peak of the mass spectrum with the mass number (theoretical value) obtained by calculation in the same manner as described above.

(Production example 2-3)
(Step 1)
800 parts of water, 60 parts of 1,3-diiminoisoindoline, and 120 parts of 28% aqueous ammonia were added in this order to a four-neck flask equipped with a reflux condenser, a dropping funnel, and a stirrer, and the mixture was stirred. A solution of 42.58 parts of 2-cyano-N-methylacetamide dissolved in 160 parts of water was added dropwise thereto over 30 minutes using a dropping funnel. The mixture was heated and stirred at 30° C. until the raw material 1,3-diiminoisoindoline disappeared. The reaction slurry was filtered using a Buchner funnel to obtain non-volatile components. The disappearance of 1,3-diiminoisoindoline was confirmed by UPLC (ultra high performance high separation liquid chromatography manufactured by Waters).
(Step 2)
Into a four-necked flask equipped with a reflux condenser, a dropping funnel, and a stirrer, 60 parts of the above nonvolatile matter and 480 parts of water were added and stirred. 53.54 parts of a 40% methylamine aqueous solution was added thereto, and the mixture was stirred at 40°C. Stirring was continued until the nonvolatile components used as raw materials disappeared. Disappearance of the raw material was confirmed by UPLC.
Thereafter, washing was performed three times with 2,400 parts of water to obtain nonvolatile components. This nonvolatile content was dried in a hot air dryer at 80° C. to obtain 58.62 parts of isoindoline compound (2-3).

<C. I. Production of Pigment Yellow 180>
(Production example 3-1) PY180-2
While stirring 1,300 parts of water, 100 parts of 1,2-bis(2-aminophenoxy)-ethane was added and dispersed, and 1 hour later, 223.9 parts of 35% hydrochloric acid was added. After further stirring for 1 hour, ice was added to adjust the temperature to 0 to 5°C, and 148.7 parts of a 38% sodium nitrite aqueous solution was added to carry out a diazotization reaction. In order to remove excess nitrite, sulfamic acid was added and stirred for 30 minutes or more to obtain a diazo component.
Separately, 190.9 parts of 5-acetoacetylamino-benzimidazolone was dispersed in 1500 parts of methanol, 393.0 parts of a 25% aqueous sodium hydroxide solution was added to dissolve it, and further sodium dialkylsulfosuccinate (Perex OT-P, 4.4 parts (manufactured by Kao Corporation) were added to obtain a coupler component.
Separately, 500 parts of ice was added to 813.5 parts of an 80% aqueous acetic acid solution, and 223.9 parts of a 25% aqueous sodium hydroxide solution was further added with stirring to prepare an acetic acid-sodium acetate buffer. While stirring the buffer solution maintained at 20° C., the diazo component and the coupler component were simultaneously added dropwise to perform a coupling reaction. The dropping rate was adjusted to such a rate that the dropping of each of the diazo component and the coupler component was completed in 2 hours. After the coupling reaction was completed, it was confirmed that no unreacted diazo component was contained in the reaction solution, and the solution was heated to 90° C. and held for 30 minutes. Next, filtration and water washing were performed to obtain a water-containing wet cake.
The entire amount of the wet cake in a water-containing state was charged into a pressurizable reaction vessel equipped with a stirring device. Add water to bring the mass inside the container to 3,500 parts, stir, and then add 200 parts of ortho-xylene and 20 parts of coconut oil fatty acid diethanolamide (Tohol N-220, manufactured by Toho Chemical Industry Co., Ltd.). Heated under autogenous pressure in an autoclave for an hour. After removing ortho-xylene by steam distillation, it was filtered, washed with water, dried at 80°C, and pulverized to obtain 257.9 parts of PY180-2. The average primary particle diameter was 260 nm.

(Production example 3-2) PY180-3
The entire amount of the wet cake in a water-containing state obtained in Production Example 3-1 was charged into a pressurizable reaction vessel equipped with a stirring device. Water was added to bring the mass inside the container to 3,500 parts with stirring, and 1,800 parts of isobutanol was further added, followed by heating at 110° C. for 2 hours under autoclave under autoclave. After removing isobutanol by steam distillation, it was filtered, washed with water, dried at 80° C., and pulverized to obtain 258.2 parts of PY180-3. The average primary particle diameter was 208 nm.

(Production Example 3-3) PY180-4
100 parts of PY180-2, 1000 parts of sodium chloride, and 150 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) and kneaded at 80° C. for 8 hours. Next, the kneaded mixture is poured into warm water at about 70°C, stirred for 1 hour to form a slurry, repeatedly filtered and washed with water to remove sodium chloride and diethylene glycol, dried at 80°C overnight, and pulverized. 95 parts of PY180-4 were obtained. The average primary particle diameter was 93 nm.

(Production example 3-4) PY180-5
100 parts of PY180-3, 1000 parts of sodium chloride, and 150 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) and kneaded at 60° C. for 8 hours. Next, the kneaded mixture is poured into warm water at about 70°C, stirred for 1 hour to form a slurry, repeatedly filtered and washed with water to remove sodium chloride and diethylene glycol, dried at 80°C overnight, and pulverized. 95 parts of PY180-5 were obtained. The average primary particle diameter was 65 nm.

<Production of phthalocyanine pigment>
(Production Example 4-1) Aluminum Phthalocyanine 1250 parts of n-amyl alcohol, 225 parts of phthalodinitrile, and 78 parts of aluminum chloride anhydride were added to a reaction vessel and mixed and stirred. To this was added 266 parts of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), the temperature was raised, and the mixture was refluxed at 136°C for 5 hours. The reaction solution, which had been cooled to 30° C. while being stirred, was poured into a mixed solvent consisting of 5,000 parts of methanol and 10,000 parts of water with stirring to obtain a blue slurry. This slurry was filtered, washed with a mixed solvent consisting of 2000 parts of methanol and 4000 parts of water, and dried to obtain 135 parts of chloroaluminum phthalocyanine represented by the following chemical formula (14).

Next, 1500 parts of concentrated sulfuric acid was added into the reaction vessel, and then 100 parts of the above chloroaluminum phthalocyanine was added in an ice bath, followed by stirring at 25°C for 4 hours. Subsequently, this sulfuric acid solution was poured into 9000 parts of cold water at 3°C, and the formed precipitate was treated in the following order: filtration, washing with water, washing with a 1% sodium hydroxide aqueous solution, washing with water, and drying. An aluminum phthalocyanine represented by the chemical formula (12) was obtained.

(Production Example 4-2) Titanyl Phthalocyanine 1280 parts of 1-hexanol, 320 parts of quinoline, 320 parts of 1,3-diiminoisoindoline, and 206.3 parts of tetrabutyl orthotitanate were added to a reaction vessel and mixed and stirred. The temperature was raised to 155°C and refluxed for 8 hours. Note that n-butanol generated within the system was recovered so as not to return to the system. Add 1000 parts of methanol to the reaction solution cooled to 60°C while stirring, filter the slurry, wash with 1000 parts of methanol, 500 parts of N-methylpyrrolidone, and 1000 parts of methanol in that order, dry, and add 250 parts of methanol. A titanyl phthalocyanine crude represented by the following chemical formula (13) was obtained.

Next, 1,500 parts of concentrated sulfuric acid was added into the reaction vessel, and then 100 parts of the above titanyl phthalocyanine crude was added in an ice bath, followed by stirring at 25°C for 4 hours. Subsequently, this sulfuric acid solution was poured into 9000 parts of cold water at 3° C., and the resulting precipitate was treated in the following order: filtration, washing with water, washing with a 1% aqueous sodium hydroxide solution, and washing with water to obtain a cake. Next, 1000 parts of diethylene glycol and the obtained cake were added to the reaction vessel and stirred to form a slurry, and the mixture was stirred at 120° C. for 3 hours. The slurry cooled to 60° C. was filtered, washed with 5000 parts of water, and dried to obtain 87 parts of titanyl phthalocyanine.

<C. I. Production of Pigment Red 122>
(Production Example 5-1) PR122-3
45.60 parts (0.2 mol) of well-dried 1,4-cyclohexanedione-2,5-di(carboxylic acid methyl ester), 53.5 parts (0.5 mol) of p-toluidine, 500 parts of methanol, Weigh 4.65 parts (0.045 mol) of 35% hydrochloric acid into a 1 liter pressure-resistant glass autoclave, seal it, and replace oxygen in the reaction vessel sufficiently with nitrogen gas, then 0 kg/cm ² at gauge pressure. The temperature was raised from room temperature to 100° C. in 15 minutes with strong stirring, and then the reaction was carried out for 3 hours. The maximum pressure in the reaction vessel during the reaction was 3.8 kg/cm ² . After the reaction, the reaction mixture was cooled to 30° C. or below and then opened to atmospheric pressure, 18 parts of a 10% aqueous sodium hydroxide solution was added thereto, and after stirring for 10 minutes, the product was filtered. The filtered cake was thoroughly washed with methanol heated to 60°C. The yield of the produced 2,5-di-p-toluidino-3,6-dihydroterephthalic acid dimethyl ester was 75.07 parts, which was 99.3% of the theoretical yield. Moreover, the purity was 99.5%.
Then, 30 parts of 2,5-di-p-toluidino-3,6-dihydroterephthalic acid dimethyl ester obtained above and 150 parts of the dimethylnaphthalene isomer mixture were placed in a 200 ml flask with an outlet valve at the bottom. The mixture was heated to 120 to 170°C while stirring under a nitrogen gas atmosphere. On the other hand, 150 parts of a dimethylnaphthalene isomer mixture was heated to 280° C. or higher while stirring under a nitrogen gas atmosphere in a 500 ml flask. After introducing the hot liquid mixture described above over 20 to 40 minutes, the mixture was held at 280 to 283°C (reflux) for 30 minutes. From the moment 2,5-dianilino-3,6-dihydroterephthalic acid dimethyl ester and the dimethylnaphthalene isomer mixture at 120-170°C are introduced into the boiling dimethylnaphthalene isomer mixture, 2,9 -Dimethyl-6,13-dihydroquinacridone production reaction started, and the generation of methanol almost stopped immediately after the start of reflux at 283°C. After cooling to 100°C, the nitrogen atmosphere was removed, the contents were filtered, washed with 500 parts of hot methanol, and dried to give 24.44 parts of 2,9-dimethyl-6,13-dihydroquinacridone (theoretical amount). 96.71%).
10 parts of 2,9-dimethyl-6,13-dihydroquinacridone obtained above and 80 parts of methanol were placed in a 200 ml flask equipped with a refluxer and stirred. Add 12 parts of 50% sodium hydroxide aqueous solution, stir at 40°C for 30 minutes, then dropwise add 26 parts of 10% sulfuric acid for hydrolysis. Immediately add 10 parts of sodium m-nitrobenzenesulfonate, and immediately add 50% water. After adding 3 parts of an aqueous sodium oxide solution, the mixture was refluxed for 4 hours. The mixture was filtered, washed with water, dried, and pulverized to obtain 9.60 parts of crude 2,9-dimethyl-quinacridone.
Next, cool to below 10°C in an ice bath, and add 9 parts of the crude 2,9-dimethyl-quinacridone obtained above to 90 parts of 98% sulfuric acid stirred in a flask, taking care not to let the temperature rise above 30°C. I added it while doing so. After adding all of these, the mixture was stirred at 30° C. or lower for 1 hour. The above sulfuric acid solution was added dropwise to 1000 parts of stirred water at 10° C. while being careful not to bump. After the addition was completed, the mixture was filtered and washed with water until it became neutral to obtain a press cake. Water was added to the resulting press cake and the pH was adjusted to 9.0 with sodium hydroxide. Next, 0.09 parts of a condensation product of stearic acid chloride and taurine, water and isobutanol were added so that the pigment solid content in the 35% isobutanol/water mixed solution became a suspension of 4%. This suspension was refluxed for 4 hours, and then the isobutanol was distilled off until the liquid temperature reached 99°C. After cooling to 70°C, filtration, washing with hot water at 60°C, drying, and pulverization yielded 8.9 parts of PR122-3. The average primary particle diameter was 163 nm.

(Production Example 5-2) PR122-4
100 parts of PR122-3, 1000 parts of sodium chloride, and 150 parts of diethylene glycol were placed in a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) and kneaded at 140° C. for 4 hours. Next, the kneaded mixture is poured into warm water at about 70°C, stirred for 1 hour to form a slurry, repeatedly filtered and washed with water to remove sodium chloride and diethylene glycol, dried at 80°C overnight, and pulverized. 95 parts of PR122-4 were obtained. The average primary particle diameter was 140 nm.

(Production Example 5-3) PR122-5
100 parts of PR122-3, 1000 parts of sodium chloride, and 150 parts of diethylene glycol were placed in a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) and kneaded at 90° C. for 8 hours. Next, the kneaded mixture is poured into warm water at about 70°C, stirred for 1 hour to form a slurry, repeatedly filtered and washed with water to remove sodium chloride and diethylene glycol, dried at 80°C overnight, and pulverized. 95 parts of PR122-4 were obtained. The average primary particle diameter was 55 nm.

(Production Example 5-4) PR122-6
To 90 parts of 98% sulfuric acid cooled to below 10°C in an ice bath and stirred in a flask, 9.5 parts of the crude 2,9-dimethyl-quinacridone obtained in Production Example 5-1 and Production Example 6 described below were added. 0.5 part of PV19-3 obtained in step-1 was added while being careful not to let the temperature rise above 30°C. After adding all of these, the mixture was stirred at 30° C. or lower for 1 hour. The above sulfuric acid solution was added dropwise to 1000 parts of stirred water at 10° C. while being careful not to bump. After the addition was completed, the mixture was filtered and washed with water until it became neutral to obtain a press cake. Water was added to the obtained press cake and the pH was adjusted to 9.0 with sodium hydroxide. Next, 0.09 parts of a condensation product of stearic acid chloride and taurine, water and isobutanol were added so that the pigment solid content in the 35% isobutanol/water mixed solution became a suspension of 4%. This suspension was refluxed for 2 hours, and then the isobutanol was distilled off until the liquid temperature reached 99°C. After cooling to 70°C, filtration, washing with hot water at 60°C, drying, and pulverization yielded 8.9 parts of PR122-6. The average primary particle diameter was 44 nm.

<C. I. Production of Pigment Violet 19>
(Production Example 6-1) PV19-3
45.6 parts (0.2 mol) of well-dried 1,4-cyclohexanedione-2,5-di(carboxylic acid methyl ester), 46.57 parts (0.5 mol) of aniline, 500 parts of methanol, 35% Weigh 4.65 parts (0.045 mol) of hydrochloric acid into a 1-liter pressure-resistant glass autoclave, seal it, and then sufficiently replace the oxygen in the reaction vessel with nitrogen gas, then set the gauge pressure to 0 kg/ ^cm2. Then, the temperature was raised from room temperature to 100°C in 15 minutes while stirring vigorously, and the reaction was carried out for 3 hours. The maximum pressure in the reaction vessel during the reaction was 3.8 kg/cm ² . After the reaction, the reaction mixture was cooled to 30° C. or lower, then opened to atmospheric pressure, 18 parts of a 10% aqueous sodium hydroxide solution was added, and after stirring for 10 minutes, the product was filtered. The filtered cake was thoroughly washed with methanol heated to 60°C. The yield of 2,5-dianilino-3,6-dihydroterephthalic acid dimethyl ester produced was 75.07 parts, which was 99.3% of the theoretical yield. Moreover, the purity was 99.5%.
Next, 30 parts of 2,5-dianilino-3,6-dihydroterephthalic acid dimethyl ester obtained above and 150 parts of the dimethylnaphthalene isomer mixture were placed in a 200 ml flask with an outlet valve at the bottom under a nitrogen gas atmosphere. The mixture was heated to 120 to 170°C while stirring. On the other hand, 150 parts of a dimethylnaphthalene isomer mixture was heated to 280° C. or higher while stirring under a nitrogen gas atmosphere in a 500 ml flask. After introducing the hot liquid mixture described above over 20 to 40 minutes, the mixture was held at 280 to 283°C (reflux) for 30 minutes. From the moment 2,5-dianilino-3,6-dihydroterephthalic acid dimethyl ester and the dimethylnaphthalene isomer mixture at 120-170°C are introduced into the boiling dimethylnaphthalene isomer mixture, 6,13 - The production reaction of dihydroquinacridone started, and the generation of methanol almost disappeared immediately after the start of reflux at 283°C. After cooling to 100°C, the nitrogen atmosphere was removed, the contents were filtered, washed with 500 parts of hot methanol, and dried to give 24.47 parts (98.2% of theory) of 6,13-dihydroquinacridone. Obtained. The purity was 99% or more by IR and absorbance.
10 parts of 6,13-dihydroquinacridone obtained above and 80 parts of methanol were charged into a 200 ml flask equipped with a reflux device and stirred. Add 12 parts of 50% sodium hydroxide aqueous solution, stir at 40°C for 30 minutes, then dropwise add 26 parts of 10% sulfuric acid for hydrolysis. Immediately add 10 parts of sodium m-nitrobenzenesulfonate, and immediately add 50% water. After adding 3 parts of an aqueous sodium oxide solution, the mixture was refluxed for 4 hours. The mixture was filtered, washed with water, dried, and pulverized to obtain 9.82 parts of PV19-3. The average primary particle diameter was 130 nm.

(Production Example 6-2) PV19-4
100 parts of PV19-3, 1000 parts of sodium chloride, and 150 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) and kneaded at 120° C. for 4 hours. Next, the kneaded mixture is poured into warm water at about 70°C, stirred for 1 hour to form a slurry, repeatedly filtered and washed with water to remove sodium chloride and diethylene glycol, dried at 80°C overnight, and pulverized. 95 parts of PV19-4 were obtained. The average primary particle diameter was 108 nm.

(Production Example 6-3) PV19-5
95 parts of PV19-3, 5 parts of PR122-5, 1000 parts of sodium chloride, and 150 parts of diethylene glycol were placed in a 1-gallon stainless steel kneader (manufactured by Inoue Seisakusho Co., Ltd.) and kneaded at 60° C. for 4 hours. Next, the kneaded mixture is poured into warm water at about 70°C, stirred for 1 hour to form a slurry, repeatedly filtered and washed with water to remove sodium chloride and diethylene glycol, dried at 80°C overnight, and pulverized. 95 parts of PV19-5 were obtained. The average primary particle diameter was 31 nm.

<1> Evaluation of gravure printing ink set First, the method for measuring resin will be explained below.
(Hydroxyl value)
It was determined according to JIS K0070.
(Acid value)
It was determined according to JIS K0070.
(amine value)
The amine value was determined according to the following method according to JIS K0070 using the equivalent amount of hydrochloric acid in mg of potassium hydroxide required to neutralize the amino groups contained in 1 g of the resin.
0.5 to 2 g of the sample was accurately weighed (sample nonvolatile content: Sg). 50 mL of a mixed solution of methanol/methyl ethyl ketone = 60/40 (mass ratio) was added to the accurately weighed sample and dissolved. Bromophenol blue was added to the obtained solution as an indicator, and the obtained solution was titrated with a 0.2 mol/L ethanolic hydrochloric acid solution (potency: f). The end point was the point at which the color of the solution changed from green to yellow, and the amine value was determined by the following formula using the titration amount (AmL) at this time.
Amine value = (A x f x 0.2 x 56.108)/S [mgKOH/g]

(Weight average molecular weight)
The weight average molecular weight was determined by measuring the molecular weight distribution using a GPC (gel permeation chromatography) device (HLC-8220, manufactured by Tosoh Corporation), and as a converted molecular weight using polystyrene as a standard substance. The measurement conditions are shown below.
Column: The following columns were connected in series and used.
Tosoh Guard Column HXL-H
Tosoh Corporation TSKgelG5000HXL
Tosoh Corporation TSKgelG4000HXL
Tosoh Corporation TSKgelG3000HXL
Tosoh Corporation TSKgelG2000HXL
Detector: RI (differential refractometer)
Measurement conditions: Column temperature 40℃
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min

(Glass-transition temperature)
The glass transition temperature (Tg) was determined by DSC (differential scanning calorimetry). The measuring device used was Rigaku DSC8231, the measurement temperature range was -70 to 250°C, the heating rate was 10°C/min, and the midpoint between the endothermic start temperature and end temperature based on the glass transition in the DSC curve was determined as the glass transition. Temperature.

(Synthesis Example 1) Polyurethane resin solution [PU1]
54.719 parts of polyester diol with a number average molecular weight of 2,000 obtained from adipic acid and 3-methyl-1,5-pentanediol, 3.989 parts of isophorone diisocyanate (hereinafter referred to as "IPDI"), n-propyl acetate (hereinafter referred to as " 10.0 parts of nPAc'') were reacted at 85° C. for 3 hours under a nitrogen stream, and 10.0 parts of nPAc was added and cooled to obtain 78.708 parts of a solvent solution of terminal isocyanate prepolymer. Next, the obtained terminal was mixed with 1.031 parts of isophoronediamine (hereinafter referred to as "IPDA"), 0.261 parts of di-n-butylamine, 72.96 parts of nPAc, and 47.04 parts of isopropanol (hereinafter referred to as "IPA"). 78.708 parts of a solvent solution of isocyanate prepolymer was gradually added at room temperature, and then reacted at 50°C for 1 hour to obtain a polyurethane resin with a nonvolatile content of 30%, a weight average molecular weight of 60,000, and an amine value of 3.0 mgKOH/g. A solution [PU1] was obtained.

(Synthesis Example 2) Polyurethane resin solution [PU2]
200 parts of polypropylene glycol (hereinafter referred to as "PPG700") having a number average molecular weight of 700, 127 parts of IPDI, and 81.8 parts of ethyl acetate were reacted at 80°C for 4 hours under a nitrogen stream to obtain a resin solution of a terminal isocyanate urethane prepolymer. Ta. Next, 49.5 parts of IPDA, 3 parts of 2-ethanolamine, and 803.9 parts of a mixed solvent of ethyl acetate/isopropanol (hereinafter referred to as "IPA") = 50/50 (mass ratio) were mixed, and the obtained terminal isocyanate urethane was added. A prepolymer resin solution was gradually added at 40°C, and then reacted at 80°C for 1 hour, resulting in a non-volatile content of 30%, an amine value of 3.5mgKOH/g, a hydroxyl value of 7.3mgKOH/g, and a weight average molecular weight of 40. 000 polyurethane resin solution [PU2] was obtained. The glass transition temperature was -32°C.

(Preparation of polyvinyl butyral resin solution [PVB1])
A polyvinyl butyral resin (weight average molecular weight 19,000) having vinyl alcohol units, vinyl acetate units and vinyl butyral units and containing 73% by mass of butyral ring groups and 26% by mass of hydroxyl groups was prepared using ethyl acetate/IPA=1/1. (Mass ratio) A polyvinyl butyral resin solution [PVB1] having a solid content of 30% was prepared by dissolving it in a mixed solvent.

(Preparation of polyvinyl butyral resin solution [PVB2])
A polyvinyl butyral resin (weight average molecular weight 33,000) having vinyl alcohol units, vinyl acetate units and vinyl butyral units and containing 77% by mass of butyral ring groups and 21% by mass of hydroxyl groups was prepared using ethyl acetate/IPA=1/1. (Mass ratio) A polyvinyl butyral resin solution [PVB2] having a solid content of 30% was prepared by dissolving it in a mixed solvent.

(Preparation of polyvinyl butyral resin solution [PVB3])
A polyvinyl butyral resin (weight average molecular weight 33,000) having vinyl alcohol units, vinyl acetate units, and vinyl butyral units and containing 84% by mass of butyral ring groups and 14% by mass of hydroxyl groups was prepared using ethyl acetate/IPA=1/1. (Mass ratio) A polyvinyl butyral resin solution [PVB3] having a solid content of 30% was prepared by dissolving it in a mixed solvent.

[Manufacture of gravure ink]
(Production Example Y1-1) [Preparation of yellow ink [Y1-1]]
7.0 parts of isoindoline compound (1-1), 29.5 parts of polyurethane resin solution [PU1], 5.0 parts of polyurethane resin solution [PU2], 20 parts of nPAc, and 5 parts of IPA were stirred and mixed, and ground in a sand mill. did. Next, 20 parts of polyurethane resin solution [PU2], 11 parts of nPAc, and 3 parts of IPA were further added and mixed and stirred to obtain yellow ink [Y1-1].

(Production examples Y1-2 to Y1-28, C1-1 to C1-5, M1-1 to M1-13) [Yellow ink [Y1-2] to [Y1-28], cyan ink [C1-1] to [C1-5], preparation of magenta ink [M1-1] to [M1-13]]
In the method for preparing yellow ink [Y1-1] described in Production Example Y1-1, 7.0 parts of isoindoline compound (1-1) was changed to the compound shown in Table 3 and the amount described in Table 3. The ink shown in Table 3 was obtained in the same manner as in Production Example Y1-1 except for the following.

(Production Example Y2-1) [Preparation of yellow ink [Y2-1]]
7.0 parts of isoindoline compound (1-3), 29.5 parts of polyurethane resin solution [PU1], 5.0 parts of polyvinyl butyral resin solution [PVB1], 20 parts of nPAc, and 5 parts of IPA were stirred and mixed, and kneaded with a sand mill. It was meat. Next, 20 parts of polyurethane resin solution [PU2], 11 parts of nPAc, and 3 parts of IPA were further added and mixed and stirred to obtain yellow ink [Y2-1].

(Production examples Y2-2 to Y2-5, C2-1 to C2-3, M2-1 to M2-9) [Yellow ink [Y2-2] to [Y2-5], cyan ink [C2-1] to [C2-3], Preparation of magenta ink [M2-1] to [M2-9]]
In the method for preparing yellow ink [Y2-1] described in Production Example Y2-1, 7.0 parts of isoindoline compound (1-3) and 5.0 parts of polyvinyl butyral resin solution [PVB1] were added as shown in Table 4. The ink shown in Table 4 was obtained in the same manner as in Production Example Y2-1 except that the compound, the amount shown in Table 4, and the polyvinyl butyral resin shown in Table 4 were changed.

Table 5 shows the pigments used in the production of the ink.

<Evaluation of ink set>
(Examples AS-1 to AS-49, Comparative Examples AS-1 to AS-11)
The obtained inks were combined as shown in Table 6 to form ink sets A1 to A60. The obtained ink set was evaluated for gamut, light resistance, and adhesion according to the following methods. The results are shown in Tables 7, 8, and 9.

[Initial gamut evaluation]
Yellow ink, cyan ink, and magenta ink were each diluted with mixed solvent 1 (methyl ethyl ketone: nPCc: IPA = 40:40:20) so that the viscosity was 16 seconds (25 ° C., Zahn Cup No. 3). . Using each diluted ink, print in the printing order of cyan, magenta A, magenta B, and yellow. A printed matter having x magenta A, yellow x magenta B, or yellow x magenta A) was obtained. The printing conditions are shown below.

(Printing conditions)
Printing machine: Fuji Kikai 5-color machine Cyan version: Helio 175L/inch, stylus angle 120°, Elongate Magenta version: Helio 175L/inch, stylus angle 120°, Compressed Yellow version: Helio 175L/inch, stylus angle 120°, Compressed Printing speed: 150 m/min Base material: Corona-treated biaxially oriented polypropylene (OPP) film (Pylene P-2161 manufactured by Toyobo Co., Ltd., 20 μm)
Drying temperature: 50℃

Regarding the obtained printed matter, the density values of the monochrome solid portions (yellow, magenta A, magenta B, cyan) of the printed matter were measured using Gretag Macbeth D196. In addition, using SpectroEye manufactured by Gretagmacbeth as a measuring device, the color of the monochrome solid area and the overprinted area was measured under the conditions of a D50 light source, a 2-degree observation field, a white background (using a standard white plate), and no filters.
In a two-dimensional space with a* as the horizontal axis and b* as the vertical axis, there are monochrome solid areas (yellow, magenta A, magenta B, cyan), and monochrome overlapping areas (yellow x cyan, cyan x magenta A, yellow). x Magenta B or Yellow x Magenta A) The values of a* versus b* for a total of 6 or 7 colors were plotted to determine the area. The area ratio was determined when the area of Comparative Example AS-1 as a standard was taken as 100%, and the area ratio was evaluated based on the following criteria. The results are shown in Table 7. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 115% or more 5: Area ratio is 110% or more but less than 115% 4: Area ratio is 105% or more but less than 110% 3: Area ratio is 100% or more but less than 105% 2: Area ratio is 98% or more and less than 100% 1: Area ratio is less than 98%

[Lightfastness evaluation 1]
(Ultraviolet irradiation test using a fedometer)
The printed matter obtained above was irradiated with ultraviolet rays for 48 hours using a fedometer (ultraviolet carbon arc lamp type light resistance tester), and after the test, the color was measured in the same manner as above. The conditions for ultraviolet irradiation were in accordance with JIS L0842:2004 and JIS B7751:2007.

(gamut)
In the same manner as the initial gamut evaluation method, the printed matter after the ultraviolet irradiation test was used to measure the color of the monochromatic solid area and the overprinted area, and the values of a* versus b* were plotted to determine the area. The area ratio of each Example and Comparative Example after the ultraviolet irradiation test was divided by the area of the initial evaluation was determined, and the area ratio was evaluated based on the following criteria. The results are shown in Table 7. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 98% or more 5: Area ratio is 97.5% or more and less than 98% 4: Area ratio is 97% or more and less than 97.5% 3: Area ratio is 96.5 % or more and less than 97% 2: Area ratio is 96% or more and less than 96.5% 1: Area ratio is less than 96%

(color difference ΔE*)
From the colorimetric results of the monochromatic solid areas (yellow, magenta A, magenta B, cyan), the color difference ΔE* before and after the ultraviolet irradiation test was determined and evaluated based on the following criteria. The results are shown in Table 7. The practical level is 3 or higher.

(Evaluation criteria)
6: ΔE* is less than 1.0 5: ΔE* is 1.0 or more and less than 1.5 4: ΔE* is 1.5 or more and less than 2.0 3: ΔE* is 2. 0 or more and less than 3.0 2: ΔE* is 3.0 or more and less than 5.0 1: ΔE* is 5.0 or more

(Hue difference ΔH*)
The hue difference ΔH* before and after the ultraviolet irradiation test was determined from the color measurement results of the monochromatic solid printed overlapping area (yellow x cyan, cyan x magenta A, yellow x magenta B, or yellow x magenta A), and evaluated based on the following criteria. The results are shown in Table 7. The practical level is 3 or higher. Also, if the hue angle (H°) after the test is larger than the H° before the test, mark it as “+”, and if the hue angle (H°) after the test is smaller than the H° before the test, mark it as “-”. Added.

(Evaluation criteria)
6: ΔH* is less than 0.5 5: ΔH* is 0.5 or more and less than 0.75 4: ΔH* is 0.75 or more and less than 1.0 3: ΔH* is 1. 0 or more and less than 1.5 2: ΔH* is 1.5 or more and less than 3.0 1: ΔH* is 3.0 or more

[Lightfastness evaluation 2]
(White LED irradiation test)
The printed matter obtained above was subjected to a white LED irradiation test using the following test method. After the test, the color was measured in the same manner as above to evaluate the stability of hue under white LED irradiation.
(Test method)
Testing machine: Incubator with lighting FLI-2010H-LED (manufactured by Tokyo Rikakikai)
Light source: white LED
Illuminance: 15000Lux
Irradiation temperature: 10℃
Irradiation humidity: 70%RH
Irradiation days: 96 hours

(gamut)
In the same manner as the initial gamut evaluation method, the printed matter after the white LED irradiation test was used to measure the color of the monochrome solid area and the overprinted area, and the values of a* versus b* were plotted to determine the area. The area after the white LED irradiation test of each Example and Comparative Example was divided by the area of the initial evaluation to determine the area ratio, and the area ratio was evaluated based on the following criteria. The results are shown in Table 8. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 98% or more 5: Area ratio is 97.5% or more and less than 98% 4: Area ratio is 97% or more and less than 97.5% 3: Area ratio is 96.5 % or more and less than 97% 2: Area ratio is 96% or more and less than 96.5% 1: Area ratio is less than 96%

(color difference ΔE*)
From the colorimetric results of the monochrome solid areas (yellow, magenta A, magenta B, cyan), the color difference ΔE* before and after the white LED irradiation test was determined and evaluated based on the following criteria. The results are shown in Table 8. The practical level is 3 or higher.

(Evaluation criteria)
6: ΔE* is less than 1.0 5: ΔE* is 1.0 or more and less than 1.5 4: ΔE* is 1.5 or more and less than 2.0 3: ΔE* is 2. 0 or more and less than 3.0 2: ΔE* is 3.0 or more and less than 5.0 1: ΔE* is 5.0 or more

(Hue difference ΔH*)
The hue difference ΔH* before and after the white LED irradiation test was determined from the colorimetric results of the monochrome solid printed overlapping area (yellow x cyan, cyan x magenta A, yellow x magenta B or yellow x magenta A), and evaluated based on the following criteria. . The results are shown in Table 8. The practical level is 3 or higher. Also, if the hue angle (H°) after the test is larger than the H° before the test, mark it as “+”, and if the hue angle (H°) after the test is smaller than the H° before the test, mark it as “-”. Added.

(Evaluation criteria)
6: ΔH* is less than 0.5 5: ΔH* is 0.5 or more and less than 0.75 4: ΔH* is 0.75 or more and less than 1.0 3: ΔH* is 1. 0 or more and less than 1.5 2: ΔH* is 1.5 or more and less than 3.0 1: ΔH* is 3.0 or more

In Tables 7 and 8, Y represents yellow, C represents cyan, MA represents magenta A, and MB represents magenta B, each representing a monochrome solid area. Furthermore, Y×C represents yellow×cyan, C×MA represents cyan×magenta A, Y×MB represents yellow×magenta B, and Y×MA represents yellow×magenta A, which are monochrome solid overlapping areas.

From the results in Tables 7 and 8, it was confirmed that the gravure printing ink set according to an embodiment of the present invention had high color reproducibility and good light resistance. In particular, when the yellow ink containing the isoindoline compound (4) or the isoindoline compound (5) was used, the color reproducibility was higher and the light resistance was better. In addition, the optimum particle size of C.I. I. When a yellow ink containing Pigment Yellow 180 was used, color reproducibility was higher and light resistance was better.
Also, C. I. Pigment Blue 15:3 or C.I. I. When cyan ink containing Pigment Blue 15:4 was used, color reproducibility was higher and light resistance was better.
In addition, the optimum particle size of C.I. I. Magenta ink A containing Pigment Red 122 and C. I. When magenta ink B containing Pigment Violet 19 was used, color reproducibility was higher and light resistance was better.
In particular, in the yellow x magenta region, with the printing ink set of the comparative example, the hue changes significantly to a bluish tinge (the hue angle becomes smaller) in the light fastness test using UV irradiation, but in the light fastness test using white LED irradiation, the hue changes significantly (the hue angle becomes smaller). The hue changed significantly to yellowishness (the hue angle became larger). That is, it can be seen that in the printing ink set of the comparative example, the hue changes over time depending on the light source, and it is difficult to obtain sufficient light resistance. On the other hand, it can be seen that the printing ink set of the embodiment of the present invention can obtain good light resistance regardless of the light source.

[Adhesiveness]
For the printed matter obtained as above using ink sets A3, A20, A40 to A49, and A60, 3 hours after printing, a 12 mm wide adhesive tape (cellophane tape manufactured by Nichiban Co., Ltd.) was pasted on the printed surface, The degree of peeling of the ink film when the tape was suddenly peeled off was visually determined. The criteria for judgment were as follows. The results are shown in Table 9. The practical level is 2 or higher.

(Evaluation criteria)
5: The ink film on the printed surface does not peel off at all 4: The peeled area of the ink film is 1% or more and less than 2% 3: The peeled area of the ink film is 2% or more and less than 3% 2: Ink film 1: The peeled area of the ink film is 5% or more.

As can be seen from the results in Table 9, the printing ink set containing polyvinyl butyral resin had better adhesion. In particular, the ink set containing a polyvinyl butyral resin with a hydroxyl group content of 25% or less had even better adhesion. In the printing ink set of the comparative example, good adhesion was not obtained even though it contained polyvinyl butyral resin.

<Manufacture of packaging materials>
(Example BP-1) [Preparation of packaging material B1]
Cyan ink [C1-1], magenta ink [M1-1], magenta ink [M1-7], and yellow ink [Y1-1] were mixed with the above mixed solvent 1 until the viscosity was 16 seconds (25°C, Zahn cup No. .3).
Using each diluted ink, a 6-color gravure proofing machine equipped with a gravure plate with a plate depth of 20 μm, black ink (Rio Alpha R92 ink (manufactured by Toyo Ink Co., Ltd.)), cyan ink [C1-1], magenta ink [ M1-1], magenta ink [M1-7], yellow ink [Y1-1], and white ink (Rio Alpha R631 White (manufactured by Toyo Ink Co., Ltd.)). Black ink, cyan ink [C1-1], magenta ink [M1-1], magenta ink [M1-7], yellow ink [Y1-1], white ink in the order of stretched polypropylene film (OPP base material) Each unit was dried at 50° C. to obtain a printed matter having a configuration of “OPP base material/black, cyan, magenta A, magenta B, yellow or white printing layer”.
Next, a urethane laminating adhesive (TM320/CAT13B manufactured by Toyo Morton Co., Ltd., ethyl acetate solution with a non-volatile content of 30%) was applied onto the printed layer of the obtained printed matter to a coating amount of 2.0 g/m ² after drying. It was coated and dried. Next, an unstretched polyethylene (PE) film with a thickness of 50 μm was laminated onto the adhesive layer to obtain packaging material B1 having the configuration of “OPP base material/5-color overlapping printing layer/adhesive layer/PE base material”. Ta.

(Examples BP-2 to BP-49, Comparative Examples BP-1 to BP-2) [Preparation of packaging materials B2 to B51]
Packaging materials B2 to B51 were obtained in the same manner as in Example BP-1, except that the printing ink set B1 used in Example BP-1 was changed to the printing ink set shown in Table 10.

As described above, packaging materials were produced using the gravure printing ink sets of this embodiment and comparison.

Among these packaging materials, the lamination strength of packaging materials B3, B20, and B40 to B51 was evaluated according to the following method. The results are shown in Table 11.

[Initial laminate strength evaluation]
Each packaging material was cut to a width of 15 mm, and after peeling between the printed layer and the adhesive layer, the peel strength was measured using a 201 universal tensile tester manufactured by Intesco. The criteria for judgment were as follows. The results are shown in Table 11. The practical level is 2 or higher.

(Evaluation criteria)
5: 2.0N/15mm or more 4: 1.5N/15mm or more, less than 2.0N/15mm 3: 1.0N/15mm or more, less than 1.5N/15mm 2: 0.5N/15mm or more, 1.0N /less than 15mm 1:0.5N/less than 15mm

[Lamination strength evaluation 1 after light resistance test]
(Ultraviolet irradiation test using a fedometer)
Each packaging material was irradiated with ultraviolet rays for 48 hours using a fedometer (ultraviolet carbon arc lamp type light resistance tester), and after the test, the peel strength was measured in the same manner as above. The conditions for ultraviolet irradiation were in accordance with JIS L0842:2004 and JIS B7751:2007.

[Lamination strength evaluation 2 after light resistance test]
(White LED irradiation test)
Each packaging material was subjected to a white LED irradiation test using the following test method. After the test, peel strength was measured in the same manner as above.
(Test method)
Testing machine: Incubator with lighting FLI-2010H-LED (manufactured by Tokyo Rikakikai)
Light source: white LED
Illuminance: 15000Lux
Irradiation temperature: 10℃
Irradiation humidity: 70%RH
Irradiation days: 96 hours

As can be seen from the results shown in Table 11, the packaging material using the printing ink set of this embodiment had good lamination strength even after the light resistance test. The packaging material using the ink set containing polyvinyl butyral resin had better lamination strength after the light fastness test. In particular, packaging materials using a printing ink set containing a polyvinyl butyral resin with a hydroxyl group content of 25% or less had even better lamination strength after the light resistance test. On the other hand, in the packaging material using the printing ink set of the comparative example, the lamination strength after the light resistance test did not reach a practical level, and good lamination strength could not be obtained even if it contained polyvinyl butyral resin.

<2> Evaluation of water-based flexo printing ink set

(Synthesis Example 3) (Synthesis of water-based polyurethane resin [PU3])
In a 4-necked 2000 ml flask equipped with a reflux condenser, a dropping funnel, a gas introduction tube, a stirrer, and a thermometer, 82.3 parts of polytetramethylene ether glycol with a number average molecular weight of 2,000, a number average molecular weight of 2, 000 polyethylene glycol, 13 parts of dimethylolbutanoic acid, and 1.7 parts of 1,4-cyclohexanedimethanol were charged, the atmosphere was replaced with dry nitrogen, and the temperature was raised to 100°C. While stirring, 33.3 parts of IPDI was added dropwise over 20 minutes, and the temperature was gradually raised to 140°C (NCO/OH=0.98). The reaction was further performed for 30 minutes to obtain a urethane resin. Next, while cooling, 399.8 parts of distilled water containing 5.3 parts of 28% ammonia water was added to obtain a water-based polyurethane resin [PU3] (weight average molecular weight was approximately 40,000, non-volatile content was 25%, acid value 36.9 (mgKOH/g), hydroxyl value 11.1 (mgKOH/g)).

(Preparation of polyvinyl butyral resin solution [PVB4])
A polyvinyl butyral resin (weight average molecular weight 19,000) having vinyl alcohol units, vinyl acetate units, and vinyl butyral units and containing 73% by mass of butyral ring groups and 26% by mass of hydroxyl groups was dissolved in IPA, and the solid content was 30% by mass. % polyvinyl butyral resin solution [PVB4] was prepared.

(Preparation of polyvinyl butyral resin solution [PVB5])
A polyvinyl butyral resin (weight average molecular weight 33,000) having vinyl alcohol units, vinyl acetate units, and vinyl butyral units and containing 77% by mass of butyral ring groups and 21% by mass of hydroxyl groups was dissolved in IPA, and the solid content was 30% by mass. % polyvinyl butyral resin solution [PVB5] was prepared.

(Preparation of polyvinyl butyral resin solution [PVB6])
A polyvinyl butyral resin (weight average molecular weight 33,000) having vinyl alcohol units, vinyl acetate units, and vinyl butyral units and containing 84% by mass of butyral ring groups and 14% by mass of hydroxyl groups was dissolved in IPA, and the solid content was 30%. % polyvinyl butyral resin solution [PVB6] was prepared.

[Manufacture of water-based flexo ink]
(Production Example Y3-1) [Preparation of yellow ink [Y3-1]]
45 parts of water-based polyurethane resin [PU3], 15 parts of isoindoline compound (1-1), polyethylene wax (W310 manufactured by Mitsui Chemicals, particle size 9.5 μm, softening point 132°C, penetration method hardness 0.8) 2 0.2 parts of adipic dihydrazide, 0.2 parts of aqueous ammonia (28%), 18.8 parts of water, and 18.8 parts of isopropanol were dispersed in an Eiger mill until the particle size became 10 μm or less using a grind gauge. Ink [Y3-1] was produced.

(Production examples Y3-2 to Y3-28, C3-1 to C3-5, M3-1 to M3-13) [Yellow ink [Y3-2] to [Y3-28], cyan ink [C3-1] to [C3-5], preparation of magenta ink [M3-1] to [M3-13]]
In the method for producing yellow ink [Y3-1] described in Production Example Y3-1, except that 15 parts of isoindoline compound (1-1) was changed to the compound shown in Table 12 and the amount shown in Table 12. The inks shown in Table 12 were obtained in the same manner as Production Example Y3-1.

(Production Example Y4-1) [Preparation of yellow ink [Y4-1]]
45 parts of water-based polyurethane resin [PU3], 15 parts of isoindoline compound (1-3), 5 parts of polyvinyl butyral resin solution [PVB4], polyethylene wax (W310 manufactured by Mitsui Chemicals, particle size 9.5 μm, softening point 132°C, Penetration method hardness 0.8) 2 parts, adipic acid dihydrazide 0.2 parts, aqueous ammonia (28%) 0.2 parts, water 18.8 parts, isopropanol 18.8 parts, and the particle size was 10 μm using a grind gauge. Yellow ink [Y4-1] was produced by dispersing with an Eiger mill until the following amount was obtained.

(Production examples Y4-2 to Y4-5, C4-1 to C4-3, M4-1 to M4-9) [Yellow ink [Y4-2] to [Y4-5], cyan ink [C4-1] to [C4-3], Preparation of magenta ink [M4-1] to [M4-9]]
In the method for preparing yellow ink [Y4-1] described in Production Example Y4-1, 15 parts of isoindoline compound (1-3) and 5 parts of polyvinyl butyral resin solution [PVB4] were mixed with the compounds shown in Table 13, The ink shown in Table 13 was obtained in the same manner as Production Example Y4-1 except that the amount shown in Table 13 was changed and the polyvinyl butyral resin shown in Table 13 was changed.

The pigments used in the production of the ink are as shown in Table 5 shown in the production of gravure ink.

<Evaluation of ink set>
(Examples CS-1 to CS-49, Comparative Examples CS-1 to CS-11)
The obtained inks were combined as shown in Table 14 to form ink sets C1 to C60. The resulting ink set was evaluated for gamut, light resistance, and adhesion using the following methods. The results are shown in Tables 15, 16, and 17.

[Initial gamut evaluation]
Using the obtained printing ink set, printing was performed in the printing order of cyan, magenta A, magenta B, and yellow under the following printing conditions, and a single color solid area (cyan, magenta A, magenta B, yellow) and a single color solid area were printed. A printed matter having an overprinted area (yellow x cyan, cyan x magenta A, yellow x magenta B or yellow x magenta A) was obtained.

(Printing conditions)
Printing machine: MIRAFLEX CM manufactured by Windmuller & Hoelscher
Flexo plate: Photosensitive resin plate, FLEXCEL NXH digital flexo plate manufactured by KODAK, plate thickness 1.14 mm, number of plate lines 150 lpi
Anilox roll: 900lpi 3cc/ ^m2
Base material: Corona-treated polyester (PET) film (manufactured by Toyobo Co., Ltd. E5100, thickness 12 μm)
Speed: 300m/min Drying temperature: Intercolor dryer 100℃, tunnel dryer 100℃

Regarding the obtained printed matter, the density values of the monochrome solid portions (yellow, magenta A, magenta B, cyan) of the printed matter were measured using Gretag Macbeth D196. In addition, using SpectroEye manufactured by Gretagmacbeth as a measuring device, the color of the monochrome solid area and the overprinted area was measured under the conditions of a D50 light source, a 2-degree observation field, a white background (using a standard white plate), and no filters.
In a two-dimensional space with a* as the horizontal axis and b* as the vertical axis, there are monochrome solid areas (yellow, magenta A, magenta B, cyan), and monochrome overlapping areas (yellow x cyan, cyan x magenta A, yellow). x Magenta B or Yellow x Magenta A) The values of a* versus b* for a total of 6 or 7 colors were plotted to determine the area. The area ratio was determined when the area of Comparative Example CS-1 as a standard was taken as 100%, and the area ratio was evaluated based on the following criteria. The results are shown in Table 15. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 115% or more 5: Area ratio is 110% or more but less than 115% 4: Area ratio is 105% or more but less than 110% 3: Area ratio is 100% or more but less than 105% 2: Area ratio is 98% or more and less than 100% 1: Area ratio is less than 98%

[Lightfastness evaluation 1]
(Ultraviolet irradiation test using a fedometer)
The printed matter obtained above was irradiated with ultraviolet rays for 48 hours using a fedometer (ultraviolet carbon arc lamp type light resistance tester), and after the test, the color was measured in the same manner as above. The conditions for ultraviolet irradiation were in accordance with JIS L0842:2004 and JIS B7751:2007.

(gamut)
In the same manner as the initial gamut evaluation method, the printed matter after the ultraviolet irradiation test was used to measure the color of the monochromatic solid area and the overprinted area, and the values of a* versus b* were plotted to determine the area. The area ratio of each Example and Comparative Example after the ultraviolet irradiation test was divided by the area of the initial evaluation was determined, and the area ratio was evaluated based on the following criteria. The results are shown in Table 15. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 98% or more 5: Area ratio is 97.5% or more and less than 98% 4: Area ratio is 97% or more and less than 97.5% 3: Area ratio is 96.5 % or more and less than 97% 2: Area ratio is 96% or more and less than 96.5% 1: Area ratio is less than 96%

(color difference ΔE*)
From the colorimetric results of the monochromatic solid areas (yellow, magenta A, magenta B, cyan), the color difference ΔE* before and after the ultraviolet irradiation test was determined and evaluated based on the following criteria. The results are shown in Table 15. The practical level is 3 or higher.

(Evaluation criteria)
6: ΔE* is less than 1.0 5: ΔE* is 1.0 or more and less than 1.5 4: ΔE* is 1.5 or more and less than 2.0 3: ΔE* is 2. 0 or more and less than 3.0 2: ΔE* is 3.0 or more and less than 5.0 1: ΔE* is 5.0 or more

(Hue difference ΔH*)
The hue difference ΔH* before and after the ultraviolet irradiation test was determined from the color measurement results of the monochromatic solid printed overlapping area (yellow x cyan, cyan x magenta A, yellow x magenta B, or yellow x magenta A), and evaluated based on the following criteria. The results are shown in Table 15. The practical level is 3 or higher. Also, if the hue angle (H°) after the test is larger than the H° before the test, mark it as “+”, and if the hue angle (H°) after the test is smaller than the H° before the test, mark it as “-”. Added.

(Evaluation criteria)
6: ΔH* is less than 0.5 5: ΔH* is 0.5 or more and less than 0.75 4: ΔH* is 0.75 or more and less than 1.0 3: ΔH* is 1. 0 or more and less than 1.5 2: ΔH* is 1.5 or more and less than 3.0 1: ΔH* is 3.0 or more

[Lightfastness evaluation 2]
(White LED irradiation test)
The printed matter obtained above was subjected to a white LED irradiation test using the following test method. After the test, the color was measured in the same manner as above to evaluate the stability of hue under white LED irradiation.
(Test method)
Testing machine: Incubator with lighting FLI-2010H-LED (manufactured by Tokyo Rikakikai)
Light source: white LED
Illuminance: 15000Lux
Irradiation temperature: 10℃
Irradiation humidity: 70%RH
Irradiation days: 96 hours

(gamut)
In the same manner as the initial gamut evaluation method, the printed matter after the white LED irradiation test was used to measure the color of the monochrome solid area and the overprinted area, and the values of a* versus b* were plotted to determine the area. The area after the white LED irradiation test of each Example and Comparative Example was divided by the area of the initial evaluation to determine the area ratio, and the area ratio was evaluated based on the following criteria. The results are shown in Table 16. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 98% or more 5: Area ratio is 97.5% or more and less than 98% 4: Area ratio is 97% or more and less than 97.5% 3: Area ratio is 96.5 % or more and less than 97% 2: Area ratio is 96% or more and less than 96.5% 1: Area ratio is less than 96%

(color difference ΔE*)
From the colorimetric results of the monochrome solid areas (yellow, magenta A, magenta B, cyan), the color difference ΔE* before and after the white LED irradiation test was determined and evaluated based on the following criteria. The results are shown in Table 16. The practical level is 3 or higher.

(Evaluation criteria)
6: ΔE* is less than 1.0 5: ΔE* is 1.0 or more and less than 1.5 4: ΔE* is 1.5 or more and less than 2.0 3: ΔE* is 2. 0 or more and less than 3.0 2: ΔE* is 3.0 or more and less than 5.0 1: ΔE* is 5.0 or more

(Hue difference ΔH*)
The hue difference ΔH* before and after the white LED irradiation test was determined from the colorimetric results of the monochrome solid printed overlapping area (yellow x cyan, cyan x magenta A, yellow x magenta B or yellow x magenta A), and evaluated based on the following criteria. . The results are shown in Table 16. The practical level is 3 or higher. Also, if the hue angle (H°) after the test is larger than the H° before the test, mark it as “+”, and if the hue angle (H°) after the test is smaller than the H° before the test, mark it as “-”. Added.

(Evaluation criteria)
6: ΔH* is less than 0.5 5: ΔH* is 0.5 or more and less than 0.75 4: ΔH* is 0.75 or more and less than 1.0 3: ΔH* is 1. 0 or more and less than 1.5 2: ΔH* is 1.5 or more and less than 3.0 1: ΔH* is 3.0 or more

In Tables 15 and 16, Y represents yellow, C represents cyan, MA represents magenta A, and MB represents magenta B, each representing a monochrome solid area. Furthermore, Y×C represents yellow×cyan, C×MA represents cyan×magenta A, Y×MB represents yellow×magenta B, and Y×MA represents yellow×magenta A, which are monochrome solid overlapping areas.

From the results in Tables 15 and 16, it was confirmed that the water-based flexographic printing ink set according to an embodiment of the present invention had high color reproducibility and good light resistance. In particular, when the yellow ink containing the isoindoline compound (4) or the isoindoline compound (5) was used, the color reproducibility was higher and the light resistance was better. In addition, the optimum particle size of C.I. I. When a yellow ink containing Pigment Yellow 180 was used, color reproducibility was higher and light resistance was better.
Also, C. I. Pigment Blue 15:3 or C.I. I. When cyan ink containing Pigment Blue 15:4 was used, color reproducibility was higher and light resistance was better.
In addition, the optimum particle size of C.I. I. Magenta ink A containing pigment red 122 and C. I. When magenta ink B containing Pigment Violet 19 was used, color reproducibility was higher and light resistance was better.
In particular, in the yellow x magenta region, in the ink set of the comparative example, the hue changes significantly to a bluish tinge (the hue angle becomes smaller) in the light fastness test using UV irradiation, but the hue changes significantly in the light fastness test using white LED irradiation. changed significantly to yellow (the hue angle became larger). That is, it can be seen that in the printing ink set of the comparative example, the hue changes over time depending on the light source, and it is difficult to obtain sufficient light resistance. On the other hand, it can be seen that the printing ink set of the embodiment of the present invention can obtain good light resistance regardless of the light source.

[Adhesiveness]
For the printed matter obtained as above using ink sets C3, C20, C40 to C49, and C60, 3 hours after printing, a 12 mm wide adhesive tape (cellophane tape manufactured by Nichiban Co., Ltd.) was pasted on the printed surface, The degree of peeling of the ink film when the tape was suddenly peeled off was visually determined. The criteria for judgment were as follows. The results are shown in Table 17. The practical level is 2 or higher.

(Evaluation criteria)
5: The ink film on the printed surface does not peel off at all 4: The peeled area of the ink film is 1% or more and less than 2% 3: The peeled area of the ink film is 2% or more and less than 3% 2: Ink film 1: The peeled area of the ink film is 5% or more.

As can be seen from the results in Table 17, the printing ink set containing polyvinyl butyral resin had better adhesion. In particular, the printing ink set containing a polyvinyl butyral resin with a hydroxyl group content of 25% or less had even better adhesion. In the printing ink set of the comparative example, good adhesion was not obtained even though it contained polyvinyl butyral resin.

<Manufacture of packaging materials>
(Example DP-1) [Preparation of packaging material D1]
Flexo printing machine, black ink (Aquariona R92F ink (manufactured by Toyo Ink Co., Ltd.)), cyan ink [C3-1], magenta ink [M3-1], magenta ink [M3-7], yellow ink [Y3-1] , black ink and cyan ink [C3-1] were applied to a 20 μm thick corona-treated stretched polypropylene film (OPP base material) using ink set D1 containing white ink (Aquariona R63 White (manufactured by Toyo Ink Co., Ltd.)). , magenta ink [M3-1], magenta ink [M3-7], yellow ink [Y3-1], and white ink were printed in this order, and each unit was dried at 100°C. /black, cyan, magenta A, magenta B, yellow or white printing layer" was obtained.
Next, a urethane laminating adhesive (TM320/CAT13B manufactured by Toyo Morton Co., Ltd., 30% non-volatile content ethyl acetate solution) was applied onto the printed layer of the obtained printed matter so that the coating amount after drying was 2.0 g/m2. It was coated and dried. Next, an unstretched polyethylene (PE) film with a thickness of 50 μm was laminated onto the adhesive layer to obtain packaging material D1 having the configuration of “OPP base material/color overlapping printing layer/adhesive layer/PE base material”. .

(Examples DP-2 to DP-49, Comparative Examples DP-1 to DP-2) [Preparation of packaging materials D2 to D51]
Packaging materials D2 to D51 were obtained in the same manner as in Example DP-1, except that the printing ink set D1 used in Example DP-1 was changed to the printing ink set shown in Table 18.

As described above, packaging materials were produced using the present embodiment and comparative aqueous flexographic printing ink sets.

Among these packaging materials, the lamination strength of packaging materials D3, D20, and D40 to D51 was evaluated according to the following method. The results are shown in Table 19.

[Initial laminate strength evaluation]
Each packaging material was cut to a width of 15 mm, and after peeling between the printed layer and the adhesive layer, the peel strength was measured using a 201 universal tensile tester manufactured by Intesco. The criteria for judgment were as follows. The results are shown in Table 19. The practical level is 2 or higher.

(Evaluation criteria)
5: 2.0N/15mm or more 4: 1.5N/15mm or more, less than 2.0N/15mm 3: 1.0N/15mm or more, less than 1.5N/15mm 2: 0.5N/15mm or more, 1.0N /less than 15mm 1:0.5N/less than 15mm

[Lamination strength evaluation 1 after light resistance test]
(Ultraviolet irradiation test using a fedometer)
Each packaging material was irradiated with ultraviolet rays for 48 hours using a fedometer (ultraviolet carbon arc lamp type light resistance tester), and after the test, the peel strength was measured in the same manner as above. The conditions for ultraviolet irradiation were in accordance with JIS L0842:2004 and JIS B7751:2007.

[Lamination strength evaluation 2 after light resistance test]
(White LED irradiation test)
Each packaging material was subjected to a white LED irradiation test using the following test method. After the test, peel strength was measured in the same manner as above.
(Test method)
Testing machine: Incubator with lighting FLI-2010H-LED (manufactured by Tokyo Rikakikai)
Light source: white LED
Illuminance: 15000Lux
Irradiation temperature: 10℃
Irradiation humidity: 70%RH
Irradiation days: 96 hours

As can be seen from the results shown in Table 19, the packaging material using the printing ink set of the embodiment of the present invention had good lamination strength even after the light resistance test. Packaging materials using a printing ink set containing polyvinyl butyral resin had better laminate strength after a lightfastness test. In particular, packaging materials using a printing ink set containing a polyvinyl butyral resin with a hydroxyl group content of 25% or less had even better lamination strength after the light resistance test. In the packaging material using the printing ink set of the comparative example, the laminate strength after the light resistance test did not reach a practical level, and good laminate strength could not be obtained even if it contained polyvinyl butyral resin.

<3> Evaluation of flexographic printing ink set (synthesis example 4) (synthesis of polyurethane resin [PU4])
A four-neck flask equipped with a reflux condenser, a dropping funnel, a gas introduction tube, a stirrer, and a thermometer was charged with 219.6 parts of polytetramethylene ether glycol having a number average molecular weight of 2,000 and 56.6 parts of IPDI. While introducing nitrogen gas, the temperature was gradually raised to 90°C, and the reaction was carried out until NCO% reached 4.4%. Next, 11.6 parts of diethylaminoethanol was added to the obtained reaction product, and the reaction was further carried out at 90°C for 3 hours to obtain a prepolymer. The prepolymer was transferred to a dropping tank using 115 parts of ethyl acetate.
Next, 12.2 parts of IPDA, 0.002 parts of dibutylamine, 345.0 parts of IPA, and 240.0 parts of ethyl acetate were charged into the reaction tank, and the above prepolymer was dropped into the reaction tank from the dropping tank over 30 minutes. After the dropwise addition was completed, the reaction was carried out at 40° C. for 1 hour to obtain a polyurethane resin [PU4] having a nonvolatile content of 30%, a weight average molecular weight of 51,000, and an amine value of 9.5 mgKOH/g.

(Preparation of CAP varnish)
A CAP varnish was prepared by mixing and dissolving cellulose acetate propionate resin (hereinafter referred to as CAP resin) with each solvent at the blending ratio shown below. As the CAP resin, the product name "CAP-504-0.2" manufactured by Eastman Chemical Company was used. This CAP resin had an acetyl group content of 2.5% by mass, a propionyl group content of 45% by mass, a hydroxyl group content of 2.6% by mass, and a glass transition temperature of 142°C.
(Blending ratio)
CAP resin: 20%
nPAc: 40%
IPA: 40%

(Preparation of polyvinyl butyral resin solution [PVB7])
A polyvinyl butyral resin (weight average molecular weight 33,000) having vinyl alcohol units, vinyl acetate units and vinyl butyral units and containing 77% by mass of butyral ring groups and 21% by mass of hydroxyl groups was prepared using ethyl acetate/IPA=1/1. (Mass ratio) A polyvinyl butyral resin solution [PVB7] having a solid content of 20% was prepared by dissolving it in a mixed solvent.

<Manufacture of flexographic ink>
(Production Example Y5-1) [Preparation of yellow ink [Y5-1]]
The following materials were pre-stirred and mixed using a high-speed mixer until a homogeneous state was obtained, and the resulting mixture was dispersed using a tabletop sand mill filled with 2 mm diameter glass beads to create yellow ink [ Y5-1] was obtained.
・Isoindoline compound (1-1): 13.0 parts ・Polyurethane resin [PU4]: 37.6 parts ・CAP varnish: 1.2 parts ・Polyvinyl butyral resin solution [PVB7]: 2.4 parts ・Polyethylene wax ( W310 manufactured by Mitsui Chemicals): 0.5 parts ・nPAc: 13.8 parts ・IPA: 31.5 parts

(Production examples Y5-2 to Y5-28, C5-1 to C5-5, M5-1 to M5-13) [Yellow ink [Y5-2] to [Y5-28], cyan ink [C5-1] to [C5-5], preparation of magenta ink [M5-1] to [M5-13]]
In the method for preparing yellow ink [Y5-1] described in Production Example Y5-1, 13.0 parts of isoindoline compound (1-1) was changed to the compound shown in Table 20 and the amount shown in Table 20. The ink shown in Table 20 was obtained in the same manner as in Production Example Y5-1 except for the above.

The pigments used in the production of the ink are as shown in Table 5 shown in the production of gravure ink.

<Evaluation of printing ink set>
(Examples ES-1 to ES-42, Comparative Examples ES-1 to ES-10)
The obtained inks were combined as shown in Table 21 to form printing ink sets E1 to E52. The resulting printing ink set was evaluated for gamut and light resistance using the following methods. The results are shown in Tables 22 and 23.

[Initial gamut evaluation]
Using the obtained ink set, print in the printing order of cyan, magenta A, magenta B, and yellow under the following printing conditions, and print a single color solid area (cyan, magenta A, magenta B, yellow) and a single color solid area. A printed matter having an overlapping portion (yellow x cyan, cyan x magenta A, yellow x magenta B or yellow x magenta A) was obtained.

(Printing conditions)
Printing machine: MIRAFLEX CM manufactured by Windmuller & Hoelscher
Flexo plate: Photosensitive resin plate, FLEXCEL NXH digital flexo plate manufactured by KODAK, plate thickness 1.14 mm, number of plate lines 150 lpi
Anilox roll: 900lpi 3cc/ ^m2
Base material: Corona-treated stretched polypropylene (OPP) film (Pylene P2161 manufactured by Toyobo Co., Ltd., thickness 40 μm)
Speed: 300m/min Drying temperature: Intercolor dryer 100℃, tunnel dryer 100℃

Regarding the obtained printed matter, the density values of the monochrome solid portions (yellow, magenta A, magenta B, cyan) of the printed matter were measured using Gretag Macbeth D196. In addition, using SpectroEye manufactured by Gretagmacbeth as a measuring device, the color of the monochrome solid area and the overprinted area was measured under the conditions of a D50 light source, a 2-degree observation field, a white background (using a standard white plate), and no filters.
In a two-dimensional space with a* as the horizontal axis and b* as the vertical axis, there are monochrome solid areas (yellow, magenta A, magenta B, cyan), and monochrome overlapping areas (yellow x cyan, cyan x magenta A, yellow). x Magenta B or Yellow x Magenta A) The values of a* versus b* for a total of 6 or 7 colors were plotted to determine the area. The area ratio was determined when the area of Comparative Example ES-1 as a standard was taken as 100%, and the area ratio was evaluated based on the following criteria. The results are shown in Table 22. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 115% or more 5: Area ratio is 110% or more but less than 115% 4: Area ratio is 105% or more but less than 110% 3: Area ratio is 100% or more but less than 105% 2: Area ratio is 98% or more and less than 100% 1: Area ratio is less than 98%

[Lightfastness evaluation 1]
(Ultraviolet irradiation test using a fedometer)
The printed matter obtained above was irradiated with ultraviolet rays for 48 hours using a fedometer (ultraviolet carbon arc lamp type light resistance tester), and after the test, the color was measured in the same manner as above. The conditions for ultraviolet irradiation were in accordance with JIS L0842:2004 and JIS B7751:2007.

(gamut)
In the same manner as the initial gamut evaluation method, the printed matter after the ultraviolet irradiation test was used to measure the color of the monochromatic solid area and the overprinted area, and the values of a* versus b* were plotted to determine the area. The area ratio of each Example and Comparative Example after the ultraviolet irradiation test was divided by the area of the initial evaluation was determined, and the area ratio was evaluated based on the following criteria. The results are shown in Table 22. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 98% or more 5: Area ratio is 97.5% or more and less than 98% 4: Area ratio is 97% or more and less than 97.5% 3: Area ratio is 96.5 % or more and less than 97% 2: Area ratio is 96% or more and less than 96.5% 1: Area ratio is less than 96%

(color difference ΔE*)
From the colorimetric results of the monochromatic solid areas (yellow, magenta A, magenta B, cyan), the color difference ΔE* before and after the ultraviolet irradiation test was determined and evaluated based on the following criteria. The results are shown in Table 22. The practical level is 3 or higher.

(Evaluation criteria)
6: ΔE* is less than 1.0 5: ΔE* is 1.0 or more and less than 1.5 4: ΔE* is 1.5 or more and less than 2.0 3: ΔE* is 2. 0 or more and less than 3.0 2: ΔE* is 3.0 or more and less than 5.0 1: ΔE* is 5.0 or more

(Hue difference ΔH*)
The hue difference ΔH* before and after the ultraviolet irradiation test was determined from the color measurement results of the monochromatic solid printed overlapping area (yellow x cyan, cyan x magenta A, yellow x magenta B, or yellow x magenta A), and evaluated based on the following criteria. The results are shown in Table 22. The practical level is 3 or higher. Also, if the hue angle (H°) after the test is larger than the H° before the test, mark it as “+”, and if the hue angle (H°) after the test is smaller than the H° before the test, mark it as “-”. Added.

(Evaluation criteria)
6: ΔH* is less than 0.5 5: ΔH* is 0.5 or more and less than 0.75 4: ΔH* is 0.75 or more and less than 1.0 3: ΔH* is 1. 0 or more and less than 1.5 2: ΔH* is 1.5 or more and less than 3.0 1: ΔH* is 3.0 or more

[Lightfastness evaluation 2]
(White LED irradiation test)
The printed matter obtained above was subjected to a white LED irradiation test using the following test method. After the test, the color was measured in the same manner as above to evaluate the stability of hue under white LED irradiation.
(Test method)
Testing machine: Incubator with lighting FLI-2010H-LED (manufactured by Tokyo Rikakikai)
Light source: white LED
Illuminance: 15000Lux
Irradiation temperature: 10℃
Irradiation humidity: 70%RH
Irradiation days: 96 hours

(gamut)
In the same manner as the initial gamut evaluation method, the printed matter after the white LED irradiation test was used to measure the color of the monochrome solid area and the overprinted area, and the values of a* versus b* were plotted to determine the area. The area after the white LED irradiation test of each Example and Comparative Example was divided by the area of the initial evaluation to determine the area ratio, and the area ratio was evaluated based on the following criteria. The results are shown in Table 23. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 98% or more 5: Area ratio is 97.5% or more and less than 98% 4: Area ratio is 97% or more and less than 97.5% 3: Area ratio is 96.5 % or more and less than 97% 2: Area ratio is 96% or more and less than 96.5% 1: Area ratio is less than 96%

(color difference ΔE*)
From the colorimetric results of the monochrome solid areas (yellow, magenta A, magenta B, cyan), the color difference ΔE* before and after the white LED irradiation test was determined and evaluated based on the following criteria. The results are shown in Table 23. The practical level is 3 or higher.

(Evaluation criteria)
6: ΔE* is less than 1.0 5: ΔE* is 1.0 or more and less than 1.5 4: ΔE* is 1.5 or more and less than 2.0 3: ΔE* is 2. 0 or more and less than 3.0 2: ΔE* is 3.0 or more and less than 5.0 1: ΔE* is 5.0 or more

(Hue difference ΔH*)
The hue difference ΔH* before and after the white LED irradiation test was determined from the colorimetric results of the monochrome solid printed overlapping area (yellow x cyan, cyan x magenta A, yellow x magenta B or yellow x magenta A), and evaluated based on the following criteria. . The results are shown in Table 23. The practical level is 3 or higher. Also, if the hue angle (H°) after the test is larger than the H° before the test, mark it as “+”, and if the hue angle (H°) after the test is smaller than the H° before the test, mark it as “-”. Added.

(Evaluation criteria)
6: ΔH* is less than 0.5 5: ΔH* is 0.5 or more and less than 0.75 4: ΔH* is 0.75 or more and less than 1.0 3: ΔH* is 1. 0 or more and less than 1.5 2: ΔH* is 1.5 or more and less than 3.0 1: ΔH* is 3.0 or more

In Tables 22 and 23, Y represents yellow, C represents cyan, MA represents magenta A, and MB represents magenta B, each representing a monochrome solid area. Furthermore, Y×C represents yellow×cyan, C×MA represents cyan×magenta A, Y×MB represents yellow×magenta B, and Y×MA represents yellow×magenta A, which are monochrome solid overlapping areas.

From the results in Tables 22 and 23, it was confirmed that the flexographic printing ink set of the present invention had high color reproducibility and good light resistance. In particular, when the yellow ink containing the isoindoline compound (4) or the isoindoline compound (5) was used, the color reproducibility was higher and the light resistance was better. In addition, the optimum particle size of C.I. I. When a yellow ink containing Pigment Yellow 180 was used, color reproducibility was higher and light resistance was better.
Also, C. I. Pigment Blue 15:3 or C.I. I. When cyan ink containing Pigment Blue 15:4 was used, color reproducibility was higher and light resistance was better.
In addition, the optimum particle size of C.I. I. Magenta ink A containing Pigment Red 122 and C. I. When magenta ink B containing Pigment Violet 19 was used, color reproducibility was higher and light resistance was better.
In particular, in the yellow x magenta region, in the ink set of the comparative example, the hue changes significantly to a bluish tinge (the hue angle becomes smaller) in the light fastness test using UV irradiation, but the hue changes significantly in the light fastness test using white LED irradiation. changed significantly to yellow (the hue angle became larger). That is, it can be seen that in the printing ink set of the comparative example, the hue changes over time depending on the light source, and it is difficult to obtain sufficient light resistance. On the other hand, it can be seen that the printing ink set of the embodiment of the present invention can obtain good light resistance regardless of the light source.

<4> Evaluation of active energy ray curable flexo printing ink set <Manufacture of active energy ray curable flexo ink>
(Production Example Y6-1) [Preparation of yellow ink [Y6-1]]
The following materials were stirred and mixed using a butterfly mixer and dispersed using three rolls so that the maximum particle size was 15 μm or less to obtain yellow ink [Y6-1].
・Isoindoline compound (1-1): 18.0 parts ・EBECRYL225: 8.4 parts (5.0 parts as active ingredient)
(10-functional urethane acrylate oligomer)
・4-acryloylmorpholine: 15.0 parts (monofunctional monomer)
・EO-modified trimethylolpropane triacrylate: 20.0 parts ・Dipentaerythritol pentaacrylate: 5.0 parts ・Dipentaerythritol hexaacrylate: 16.6 parts ・Irgacure 369: 3.0 parts (photopolymerization initiator)
・Chemrk DEABP: 3.0 parts (photopolymerization initiator)
・SB-PI718: 4.0 parts (photopolymerization initiator)
・Ajisper PB821: 3.0 parts (dispersant)
・T wax compound: 4.0 parts (wax)

Details of the materials used are as follows.

[Acrylate oligomer]
・EBECRYL225: Daicel Allnex Corporation, 10-functional aliphatic urethane acrylate oligomer, Mw 1,200, active ingredient 60% by mass [polymerization initiator]
・Irgacure 369: manufactured by BASF, 2-benzyl-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone ・Chemrk DEABP: manufactured by Sort, 4,4'-bis(diethylamino)benzophenone・SB-PI718: Manufactured by Sort, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide [dispersant]
・Ajisper PB821: Manufactured by Ajinomoto Fine Techno Co., Ltd., comb-shaped dispersant containing basic functional groups [wax]
・T wax compound: Polyethylene wax manufactured by Toshin Yushi Co., Ltd.

(Production examples Y6-2 to Y6-28, C6-1 to C6-5, M6-1 to M6-13) [Yellow ink [Y6-2] to [Y6-28], cyan ink [C6-1] to [C6-5], preparation of magenta ink [M6-1] to [M6-13]]
In the method for preparing yellow ink [Y6-1] described in Production Example Y6-1, 18.0 parts of isoindoline compound (1-1) was changed to the compound shown in Table 24 and the amount shown in Table 24. The inks listed in Table 24 were obtained in the same manner as in Production Example Y6-1 except for the following.

The pigments used in the production of the ink are as shown in Table 5 shown in the production of gravure ink.

<Evaluation of ink set>
(Examples FS-1 to FS-42, Comparative Examples FS-1 to FS-10)
The obtained inks were combined as shown in Table 25 to form ink sets F1 to F52. The resulting ink set was evaluated for gamut and light resistance using the following methods. The results are shown in Tables 26 and 27.

[Initial gamut evaluation]
In the ink set obtained above, after printing cyan ink on coated paper using an anilox roller with a line count of 800 lpi and a cell volume of 3.72 cm ³ /m ² and a flexi-proof machine, the cyan ink was printed at a conveyor speed of 50 m/min, with air-cooled mercury. It was cured using a lamp (output: 160 W/cm ² ). Then, print magenta ink on the cyan ink layer and yellow ink on the magenta ink layer under the same conditions as cyan ink, and stack the base material, cyan ink layer, magenta ink layer, and yellow ink layer in this order. A printed matter for evaluation was obtained.
Using the obtained ink set, under the following printing conditions, monochrome solid areas (cyan, magenta A, magenta B, yellow) and monochrome solid overlapping areas (yellow x cyan, cyan x magenta A, yellow x magenta B) were printed. Or yellow x magenta A) was obtained.

(Single color solid area)
After printing ink on coated paper using an anilox roller with a line count of 800 lpi and a cell volume of 3.72 cm ³ /m ² and a flexi-proof machine, a conveyor speed of 50 m/min and an air-cooled mercury lamp (output 160 w/cm ² conditions) were applied. was cured to obtain a printed matter for evaluation.

(Single color solid printing overlapping area)
After printing cyan ink on coated paper using an anilox roller with a line count of 800 lpi and a cell volume of 3.72 cm ³ /m ² and a flexi-proof machine, the conditions were as follows: conveyor speed 50 m/min, air-cooled mercury lamp (output 160 w/cm ^{2 )} ) was cured. Thereafter, magenta ink was printed on the cyan ink layer under the same conditions as the cyan ink, to obtain a printed matter for evaluation in which the base material, the cyan ink layer, and the magenta ink layer were laminated in this order.
Furthermore, printing was performed under the same conditions using yellow ink instead of magenta ink to obtain an evaluation printed matter in which the base material, cyan ink layer, and yellow ink layer were laminated in this order.
In addition, printing was performed under the same conditions using magenta ink instead of cyan ink and yellow ink instead of magenta ink to obtain evaluation printed matter in which the base material, magenta ink layer, and yellow ink layer were laminated in this order. .

Regarding the obtained printed matter, the density values of the monochrome solid portions (yellow, magenta A, magenta B, cyan) of the printed matter were measured using Gretag Macbeth D196. In addition, using SpectroEye manufactured by Gretagmacbeth as a measuring device, the color of the monochrome solid area and the overprinted area was measured under the conditions of a D50 light source, a 2-degree observation field, a white background (using a standard white plate), and no filters.
In a two-dimensional space with a* as the horizontal axis and b* as the vertical axis, there are monochrome solid areas (yellow, magenta A, magenta B, cyan), and monochrome overlapping areas (yellow x cyan, cyan x magenta A, yellow). x Magenta B or Yellow x Magenta A) The values of a* versus b* for a total of 6 or 7 colors were plotted to determine the area. The area ratio was determined when the area of Comparative Example FS-1 as a standard was taken as 100%, and the area ratio was evaluated based on the following criteria. The results are shown in Table 26. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 115% or more 5: Area ratio is 110% or more but less than 115% 4: Area ratio is 105% or more but less than 110% 3: Area ratio is 100% or more but less than 105% 2: Area ratio is 98% or more and less than 100% 1: Area ratio is less than 98%

[Lightfastness evaluation 1]
(Ultraviolet irradiation test using a fedometer)
The printed matter obtained above was irradiated with ultraviolet rays for 48 hours using a fedometer (ultraviolet carbon arc lamp type light resistance tester), and after the test, the color was measured in the same manner as above. The conditions for ultraviolet irradiation were in accordance with JIS L0842:2004 and JIS B7751:2007.

(gamut)
In the same manner as the initial gamut evaluation method, the printed matter after the ultraviolet irradiation test was used to measure the color of the monochromatic solid area and the overprinted area, and the values of a* versus b* were plotted to determine the area. The area ratio of each Example and Comparative Example after the ultraviolet irradiation test was divided by the area of the initial evaluation was determined, and the area ratio was evaluated based on the following criteria. The results are shown in Table 26. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 98% or more 5: Area ratio is 97.5% or more and less than 98% 4: Area ratio is 97% or more and less than 97.5% 3: Area ratio is 96.5 % or more and less than 97% 2: Area ratio is 96% or more and less than 96.5% 1: Area ratio is less than 96%

(color difference ΔE*)
From the colorimetric results of the monochromatic solid areas (yellow, magenta A, magenta B, cyan), the color difference ΔE* before and after the ultraviolet irradiation test was determined and evaluated based on the following criteria. The results are shown in Table 26. The practical level is 3 or higher.

(Evaluation criteria)
6: ΔE* is less than 1.0 5: ΔE* is 1.0 or more and less than 1.5 4: ΔE* is 1.5 or more and less than 2.0 3: ΔE* is 2. 0 or more and less than 3.0 2: ΔE* is 3.0 or more and less than 5.0 1: ΔE* is 5.0 or more

(Hue difference ΔH*)
The hue difference ΔH* before and after the ultraviolet irradiation test was determined from the color measurement results of the monochromatic solid printed overlapping area (yellow x cyan, cyan x magenta A, yellow x magenta B, or yellow x magenta A), and evaluated based on the following criteria. The results are shown in Table 26. The practical level is 3 or higher. Also, if the hue angle (H°) after the test is larger than the H° before the test, mark it as “+”, and if the hue angle (H°) after the test is smaller than the H° before the test, mark it as “-”. Added.

(Evaluation criteria)
6: ΔH* is less than 0.5 5: ΔH* is 0.5 or more and less than 0.75 4: ΔH* is 0.75 or more and less than 1.0 3: ΔH* is 1. 0 or more and less than 1.5 2: ΔH* is 1.5 or more and less than 3.0 1: ΔH* is 3.0 or more

[Lightfastness evaluation 2]
(White LED irradiation test)
The printed matter obtained above was subjected to a white LED irradiation test using the following test method. After the test, the color was measured in the same manner as above to evaluate the stability of hue under white LED irradiation.
(Test method)
Testing machine: Incubator with lighting FLI-2010H-LED (manufactured by Tokyo Rikakikai)
Light source: white LED
Illuminance: 15000Lux
Irradiation temperature: 10℃
Irradiation humidity: 70%RH
Irradiation days: 96 hours

(gamut)
In the same manner as the initial gamut evaluation method, the printed matter after the white LED irradiation test was used to measure the color of the monochrome solid area and the overprinted area, and the values of a* versus b* were plotted to determine the area. The area after the white LED irradiation test of each Example and Comparative Example was divided by the area of the initial evaluation to determine the area ratio, and the area ratio was evaluated based on the following criteria. The results are shown in Table 27. The practical level is 3 or higher.

(Evaluation criteria)
6: Area ratio is 98% or more 5: Area ratio is 97.5% or more and less than 98% 4: Area ratio is 97% or more and less than 97.5% 3: Area ratio is 96.5 % or more and less than 97% 2: Area ratio is 96% or more and less than 96.5% 1: Area ratio is less than 96%

(color difference ΔE*)
From the colorimetric results of the monochrome solid areas (yellow, magenta A, magenta B, cyan), the color difference ΔE* before and after the white LED irradiation test was determined and evaluated based on the following criteria. The results are shown in Table 27. The practical level is 3 or higher.

(Evaluation criteria)
6: ΔE* is less than 1.0 5: ΔE* is 1.0 or more and less than 1.5 4: ΔE* is 1.5 or more and less than 2.0 3: ΔE* is 2. 0 or more and less than 3.0 2: ΔE* is 3.0 or more and less than 5.0 1: ΔE* is 5.0 or more

(Hue difference ΔH*)
The hue difference ΔH* before and after the white LED irradiation test was determined from the colorimetric results of the monochrome solid printed overlapping area (yellow x cyan, cyan x magenta A, yellow x magenta B or yellow x magenta A), and evaluated based on the following criteria. . The results are shown in Table 27. The practical level is 3 or higher. Also, if the hue angle (H°) after the test is larger than the H° before the test, mark it as “+”, and if the hue angle (H°) after the test is smaller than the H° before the test, mark it as “-”. Added.

(Evaluation criteria)
6: ΔH* is less than 0.5 5: ΔH* is 0.5 or more and less than 0.75 4: ΔH* is 0.75 or more and less than 1.0 3: ΔH* is 1. 0 or more and less than 1.5 2: ΔH* is 1.5 or more and less than 3.0 1: ΔH* is 3.0 or more

In Tables 26 and 27, Y represents yellow, C represents cyan, MA represents magenta A, and MB represents magenta B, each representing a monochrome solid area. Furthermore, Y×C represents yellow×cyan, C×MA represents cyan×magenta A, Y×MB represents yellow×magenta B, and Y×MA represents yellow×magenta A, which are monochrome solid overlapping areas.

From the results in Tables 26 and 27, it was confirmed that the active energy ray-curable flexographic printing ink set according to an embodiment of the present invention had high color reproducibility and good light resistance. In particular, when the yellow ink containing the isoindoline compound (4) or the isoindoline compound (5) was used, the color reproducibility was higher and the light resistance was better. In addition, the optimum particle size of C.I. I. When a yellow ink containing Pigment Yellow 180 was used, color reproducibility was higher and light resistance was better.
Also, C. I. Pigment Blue 15:3 or C.I. I. When cyan ink containing Pigment Blue 15:4 was used, color reproducibility was higher and light resistance was better.
In addition, the optimum particle size of C.I. I. Magenta ink A containing Pigment Red 122 and C. I. When magenta ink B containing Pigment Violet 19 was used, color reproducibility was higher and light resistance was better.
In particular, in the yellow x magenta region, with the printing ink set of the comparative example, the hue changes significantly to a bluish tinge (the hue angle becomes smaller) in the light fastness test using UV irradiation, but in the light fastness test using white LED irradiation, the hue changes significantly (the hue angle becomes smaller). The hue changed significantly to yellowishness (the hue angle became larger). That is, it can be seen that in the printing ink set of the comparative example, the hue changes over time depending on the light source, and it is difficult to obtain sufficient light resistance. On the other hand, it can be seen that the printing ink set of the embodiment of the present invention can obtain good light resistance regardless of the light source.

Claims (6)

An isoindoline compound represented by the following general formula (1) or C.I. I. Yellow ink containing Pigment Yellow 180 and a dispersion medium;
cyan ink comprising a phthalocyanine pigment and a dispersion medium;
C. I. magenta ink A containing pigment red 122 and a dispersion medium, and C. I. A printing ink set comprising magenta ink B containing pigment violet 19 and a dispersion medium.

[In general formula (1), R ₁ to R ₄ each independently represent a hydrogen atom, an alkyl group, or an alkoxy group. R ₅ and R ₆ each independently represent a hydrogen atom or an alkyl group. X ₁ represents -O- or -NH-, and R ₇ represents a hydrogen atom, an alkyl group, or an aryl group. ] The printing ink set according to claim 1, wherein the isoindoline compound represented by the general formula (1) contains at least one compound selected from the group consisting of the following formulas (4) and (5).

The printing ink set according to claim 1, which is used for gravure printing. The printing ink set according to claim 1, which is used for flexographic printing. A printed matter comprising a base material and a printing layer formed from the printing ink set according to any one of claims 1 to 4. A packaging material comprising the printed matter according to claim 5.