Pigment composition, method for producing the same, and use thereof

Abstract

To provide a pigment composition that enables formation of an ink layer with high lamination strength and superior transparency.SOLUTION: A pigment composition, comprising an azo lake pigment (B1) which is a lake reaction product of an azo dye (A) with calcium, and an azo lake pigment (B2) which is a lake reaction product of the azo dye (A) with barium, wherein the content of the azo dye (A) in the pigment composition is 0 mass% or more and 1 mass% or less. The average primary particle diameter of the pigment composition is preferably 80 nm or more and 500 nm or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a pigment composition containing an azo lake pigment. [Background technology]

[0002] Monoazo lake pigments, obtained by coupling a soluble aromatic amine as the diazo component with 3-hydroxy-2-naphthalenecarboxylic acid, β-naphthol, or other coupler components, are widely used in coloring printing inks, paints, and plastics. Monoazo lake pigments are rosin-treated to make their color more transparent and vivid, and to improve their dispersibility. Rosin treatment typically involves adding an alkali salt solution of rosin (known as rosin soap) to the coupler component or dye, followed by the addition of a lake metal salt such as calcium chloride, which precipitates the rosin on the pigment surface as an insoluble rosin lake metal salt.

[0003] Patent Document 1 discloses a monoazo lake pigment obtained by laking an azo dye obtained by coupling a diazonium salt of an aromatic amine having a solubilizing group with a coupler component, and a coated monoazo lake pigment comprising rosin and a sulfosuccinate or a hydrolyzate thereof that coats the monoazo lake pigment. Patent Document 2 discloses a pigment composition in which rosin aluminum salt powder is added to a monoazo lake pigment. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 6-313120 [Patent Document 2] Patent Publication No. 07-278459 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when using gravure inks using conventional pigment compositions for laminate printing, there was a problem in that the lamination strength of the ink layer was low due to the effects of rosin treatment. Because rosin treatment contributes to accelerating the lake reaction of azo dyes, if monoazo lake pigments are not rosin treated, the azo dye remaining in the pigment composition will grow into azo dye particles upon subsequent heating or drying, resulting in a problem of reduced transparency of the ink layer.

[0006] An object of the present invention is to provide a pigment composition that can form an ink layer having high lamination strength and good transparency. [Means for solving the problem]

[0007] <1> The pigment composition of the present invention comprises an azo lake pigment (B1) which is a laked reaction product of an azo dye (A) with calcium, and an azo lake pigment (B2) which is a laked reaction product of an azo dye (A) with barium, The content of the azo dye (A) in the pigment composition is 0% by mass or more and 1% by mass or less. <2> The azo dye (A) is a compound represented by the following chemical formula (1) or (2): <1> Pigment composition. [ka] <3> The average primary particle size is 80 nm or more and 500 nm or less. <1> or <2> Pigment composition. <4> The rosin content in the pigment composition is 0% by mass or more and 10% by mass or less. <1> ~ <3> Any pigment composition. <5> Furthermore, surfactants are included. <1> ~ <4> Any pigment composition. <6> <1> ~ <5> A method for producing the pigment composition according to any one of claims 1 to 4, comprising the steps of mixing a diazonium salt of an aromatic amine having a solubilizing group with a calcium metal salt and a barium metal salt, and then subjecting the resulting mixture to a coupling reaction with a coupler component. <7> <1> ~ <5> A method for producing the pigment composition according to any one of the preceding claims, comprising the step of adding a calcium metal salt and a barium metal salt to the azo dye (A) and carrying out a laking reaction. <8> <1> ~ <5> A printing ink comprising any of the pigment compositions. <9> <8> A printed matter formed from printing ink. <10> <9> Packaging material having printed matter. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a pigment composition capable of forming an ink layer having high lamination strength and good transparency. The present invention also provides a printing ink, a printed matter, a packaging material, and a method for producing the pigment composition. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and the present invention also includes embodiments that are implemented within the scope of the present invention. In this specification, "CI" means color index (CI).

[0010] The pigment composition of the present invention contains an azo lake pigment (B1) which is a laked reaction product of an azo dye (A) with calcium, and an azo lake pigment (B2) which is a laked reaction product of an azo dye (A) with barium, and the content of the azo dye (A) in the pigment composition is 0% by mass or more and 1% by mass or less.

[0011] The mechanism by which the pigment composition of the present invention can solve the problem is presumed to be as follows. According to an embodiment of the present invention, when a lake formation reaction is carried out using a calcium metal salt and a barium metal salt, the lake formation rate is improved compared to when a lake formation reaction is carried out using only a calcium metal salt, and the amount of remaining azo dye is reduced. As a result, crystal growth of the pigment particles is suppressed, and fine pigment particles are obtained. Due to this effect, when the pigment composition of the present invention is used in, for example, a printing ink, printed matter can be obtained that has improved printability (lamination strength) compared to rosin-treated azo lake pigments.

[0012] <Azo Lake Pigments> The pigment composition of the present invention contains an azo lake pigment (B1) which is a laked reaction product of the azo dye (A) with calcium, and an azo lake pigment (B2) which is a laked reaction product of the azo dye (A) with barium.

[0013] <Azo dyes (A)> The azo dye (A) is a compound represented by the general formula (1). General formula (1) BN=NC Azo dyes (A) are compounds in which two aromatic rings are bonded by an azo group, and are produced by diazotizing the base component B-NH2 (BN≡N + The compound of general formula (1) is obtained by reacting the azo dye (A) with a coupler component C. The azo dye (A) preferably has an acidic group, and examples of the acidic group include a sulfonic acid group and a carboxy group.

[0014] Examples of the base component B-NH2 include aromatic amine compounds. The aromatic amine compound is preferably a compound having a solubilizing group, and examples of the solubilizing group include a sulfonic acid group and a carboxyl group. Examples of the aromatic amine include 4-aminotoluene-3-sulfonic acid (p-toluidine-m-sulfonic acid: 4B acid), 4-amino-2-chlorotoluene-5-sulfonic acid (2B acid), 3-amino-6-chlorotoluene-4-sulfonic acid (C acid), and 2-aminonaphthalene-1-sulfonic acid (Tobias acid).

[0015] Examples of the coupler component C include 3-hydroxy-2-naphthalenecarboxylic acid, β-naphthol, and acetoacetanilide.

[0016] In the present invention, the coupler component and the aromatic amine component (base component) that constitutes the diazonium salt can be combined in any manner. Suitable combinations of coupler components and base components include a compound represented by the following chemical formula (1), which combines 4-amino-2-chlorotoluene-5-sulfonic acid and 3-hydroxy-2-naphthalenecarboxylic acid; a compound represented by the following chemical formula (2), which combines 4-aminotoluene-3-sulfonic acid and 3-hydroxy-2-naphthalenecarboxylic acid; and a compound represented by the following chemical formula (3), which combines 2-amino-5-chloro-4-methylbenzenesulfonic acid and 2-naphthol. Among these, compounds represented by chemical formula (1) or (2) are preferred from the viewpoint of hue.

[0017] [ka]

[0018] In the present invention, the polyvalent metal salt used in the laking reaction of the azo dye (A) is a divalent calcium salt or a divalent barium salt, and water-soluble salts thereof are more preferred. Examples of the water-soluble salt include calcium chloride and barium chloride.

[0019] The azo dye shown in chemical formula (1) can be used in a lake reaction with barium to synthesize CI Pigment Red 48:1. Similarly, the azo dye shown in chemical formula (2) can be used in a lake reaction with calcium to synthesize CI Pigment Red 57:1. Similarly, the azo dye shown in chemical formula (3) can be used in a lake reaction with barium to synthesize CI Pigment Red 53:1. Similarly, the azo dye shown in chemical formula (3) can be used in a lake reaction with barium to synthesize CI Pigment Red 53:2.

[0020] The mass ratio of the azo lake pigment (B1) to the azo lake pigment (B2) is preferably B1:B2=19:1 to 2:1, more preferably 12:1 to 4:1.

[0021] <Method of producing pigment composition> The pigment composition of the present invention is preferably produced by a method comprising the steps of mixing a diazonium salt of an aromatic amine having a solubilizing group with a calcium metal salt and a barium metal salt, followed by a coupling reaction with a coupler component, or by a method comprising the steps of adding a calcium metal salt and a barium metal salt to the azo dye (A) to carry out a laking reaction.

[0022] The method for producing the pigment composition will be described in detail below. In the present invention, the azo lake pigment can be synthesized by the following methods. Examples of methods for synthesizing the azo lake pigment include Production Method 1, in which a metal salt is added to a diazo solution or a coupler solution in advance, followed by a coupling reaction and a laking reaction to synthesize the azo lake pigment, and Production Method 2, in which a diazo solution is reacted with a coupler solution to synthesize an azo dye, followed by adding a metal salt and synthesizing the azo dye by a laking reaction. Among these, Method 1 is preferred. In Method 2, a calcium metal salt is preferably mixed first, followed by a barium metal salt. This method can further improve the laking reaction rate.

[0023] The content of unreacted azo dye (A) in the pigment composition is preferably 0% by mass or more and 1% by mass or less, and more preferably 0.5% by mass or less. When the content of unreacted azo dye (A) is within the above range, the growth of pigment particles can be further suppressed, thereby further improving transparency and color development.

[0024] The average value of the major axis of the primary particles of the pigment composition of the present invention (hereinafter also referred to as "average primary particle diameter") is preferably 80 to 500 nm, more preferably 100 to 400 nm, and even more preferably 120 to 300 nm, from the viewpoint of the color development and transparency of the coating film. Details of the methods for measuring the major axis and minor axis of the primary particles and the method for calculating the average value are shown in the Examples.

[0025] The pigment composition of the present invention can contain rosin as long as the problem can be solved. The rosin content is preferably 0% by mass or more and 10% by mass or less, more preferably 7% by mass or less, even more preferably 3% by mass or less, and particularly preferably 1% by mass or less, of the nonvolatile content of the pigment composition.

[0026] In the pigment composition of the present invention, the total number of moles of calcium and barium contained in the calcium metal salt and barium metal salt used is preferably 50 or more, more preferably 52.5 or more, relative to a total of 100 moles of acidic groups contained in the azo dye (A). The molar ratio of calcium to barium contained in each metal salt is preferably 19:1 to 2:1, more preferably 12:1 to 4:1.

[0027] <Surfactant> The pigment composition of the present invention can contain a surfactant. This can reduce pigment particle aggregation. Examples of surfactants include anionic surfactants and nonionic surfactants. Among these, anionic surfactants are preferred. Examples of anionic surfactants include fatty acid salts, alkyl sulfate ester salts, alkylaryl sulfonates, alkylnaphthalene sulfonates, alkyl sulfates, dialkyl sulfosuccinates, alkyl phosphates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylaryl ether sulfates, naphthalene sulfonate-formalin condensates, polyoxyethylene alkyl ether phosphates, and polyoxyethylene alkyl phosphate ester salts. Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene-polyoxypropylene block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, and glycerin fatty acid esters. The surfactants can be used alone or in combination and can be added to the coupler solution or to the suspension after coupling.

[0028] <Printing ink> The printing ink of the present invention preferably contains the pigment composition, a binder resin, and a liquid medium. The liquid medium is not particularly limited as long as it is a medium capable of dispersing the pigment composition. Examples of the liquid medium include organic solvents.

[0029] Examples of the binder resin include acrylic resin, polyester resin, styrene resin, styrene-maleic acid resin, maleic acid resin, vinyl chloride-vinyl acetate copolymer resin, polyurethane resin, polyamide resin, and cellulose-based resin.

[0030] Examples of organic solvents include aromatic organic solvents such as toluene and xylene; ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester organic solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate, and isobutyl acetate; and alcohol organic solvents such as methanol, ethanol, 1-propanol (n-propanol), isopropanol, and n-butanol.

[0031] The binder resin and the liquid medium may be used alone or in combination.

[0032] The printing ink of the present invention may contain an appropriate selection of additives, such as pigment derivatives, extender pigments, dispersants, wetting agents, adhesion aids, silica particles, leveling agents, antifoaming agents, antistatic agents, trapping agents, antiblocking agents, wax components, isocyanate-based curing agents, and silane coupling agents. Examples of the wax component include fatty acid amide wax and hydrocarbon wax, which improve the blocking resistance of the ink layer. Examples of the printing ink of the present invention include gravure ink, flexographic ink, inkjet ink, etc. Among these, gravure ink is preferred.

[0033] <Printed material> The printed matter of the present invention has an ink layer (printed layer) formed from a printing ink. The ink layer may be a solid layer, provided that it has a halftone or dot pattern. The printing ink used in the printed matter of the present invention is not limited as long as it can form an ink layer, but gravure ink is particularly preferred. The thickness of the ink layer is about 2 to 30 μm. Gravure ink is printed using the gravure printing method. In gravure printing, the gravure ink is diluted with a diluting solvent to a viscosity and concentration suitable for printing, and then supplied to the printing unit of a printing press. The gravure ink is then printed onto a substrate, and the volatile components are removed by drying, forming a printed layer to create a printed product.

[0034] <Base material> Examples of the substrate include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate, polycarbonate, and polylactic acid; polystyrene-based resins such as polystyrene, AS resin, and ABS resin; nylon, polyamide, polyvinyl chloride, polyvinylidene chloride, cellophane, paper, aluminum, and the like, or film-like substrates made from composite materials of these. Vapor-deposited substrates in which inorganic compounds such as silica, alumina, and aluminum are vapor-deposited onto polyethylene terephthalate or nylon film can also be used, and the vapor-deposited surface of the inorganic compound or the like may be coated with polyvinyl alcohol or the like, and may further be subjected to a surface treatment such as corona treatment. The thickness of the substrate is about 10 to 250 μm.

[0035] <Packaging materials> The packaging material of the present invention includes the printed matter. For example, the packaging material may be configured by sequentially laminating a printed matter, an adhesive layer, and a sealant substrate. Examples of packaging materials include packages of various shapes, such as four-sided sealed packages, three-sided sealed packages, pillow packages, stick bags, gusset bags, square-bottom bags, standing pouches, deep-draw containers, vacuum packages, skin packs, zipper bags, spout pouches, twist packages, wrap packages, shrink packages, labels, liquid paper cartons, and paper trays, which can store the contents. The packaging material of this specification is not limited to the above uses, as long as it can store the contents.

[0036] Examples of items packaged in packaging materials include food products (e.g., rice, confectionery, seasonings, edible oils and fats, cooked foods, etc.), beverages (e.g., alcoholic beverages, soft drinks, mineral water, etc.), daily necessities (e.g., pharmaceuticals, cosmetics, stationery, etc.), electronic components, etc. [Example]

[0037] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. Unless otherwise specified, "parts" means parts by mass, and "%" means % by mass.

[0038] [Particle size measurement] The average primary particle diameter of the pigment compositions of the Examples and Comparative Examples was determined by the following method through observation with a transmission electron microscope (TEM). Fifty primary particles of the pigment composition were randomly selected from multiple photographs taken at 10,000x magnification using a transmission electron microscope, and a rectangle with the smallest area circumscribing the particle image was drawn. The length of the long side of the rectangle was taken as the major axis, and the average major axis value was calculated. The average major axis value was rounded to the nearest 1st digit to obtain the average primary particle diameter, which is shown in Table 1.

[0039] [Manufacturing Example 1] - Manufacturing of binder resin solution BD1 170 parts of a polyester polyol (hereinafter referred to as "NPG / AA") obtained from adipic acid and neopentyl glycol having a number average molecular weight of 2,000, 30 parts of polyethylene glycol (hereinafter referred to as "PEG") having a number average molecular weight of 1,000, 58.8 parts of isophorone diisocyanate (hereinafter referred to as "IPDI"), and 64.7 parts of ethyl acetate were reacted with stirring under a nitrogen stream at 80°C for 4 hours to obtain a solution of a terminal isocyanate prepolymer. Next, the obtained isocyanate-terminated prepolymer solution was gradually added at 40°C to a mixture obtained by mixing and stirring 25.8 parts of isophoronediamine (hereinafter "IPDA"), 2.0 parts of iminobispropylamine (hereinafter "IBPA"), 1.5 parts of 2-ethanolamine (hereinafter "2EtAm"), and 607.4 parts of a mixed solvent of ethyl acetate / isopropanol (hereinafter "IPA") = 70 / 30. The mixture was then allowed to react at 80°C for 1 hour, yielding binder resin solution BD1 with a non-volatile content of 30%, an amine value of 11.1 mg KOH / g, a hydroxyl value of 4.8 mg KOH / g, and a weight average molecular weight of 40,000.

[0040] Example 1 Preparation of pigment composition (1) 380 parts of 4-aminotoluene-3-sulfonic acid as a base component was added to 1,700 parts of water and stirred, after which 308 parts of 35% hydrochloric acid was added to precipitate the mixture, and 1,100 parts of ice was added to lower the liquid temperature to 0°C. Next, 650 parts of a 35% aqueous calcium chloride solution and 42 parts of barium chloride dihydrate were added and stirred for 10 minutes, followed by 350 parts of a 40% aqueous sodium nitrite solution, and water was added to bring the total volume to 7,000 parts, and the mixture was stirred at 0°C for 60 minutes to obtain a diazo solution. In a separate vessel, 3,000 parts of water, 380 parts of 3-hydroxy-2-naphthalenecarboxylic acid as a coupler component, and 700 parts of a 25% aqueous sodium hydroxide solution were added and stirred to dissolve. 5,000 parts of water and 26 parts of lanthanum oil (manufactured by Taiko Yushi Kagaku Kogyo Co., Ltd., alkyl sulfate ester salt) as an anionic surfactant were added, and the mixture was heated to 35°C. Water was added to bring the total volume to 11,200 parts, yielding a coupler solution. The diazo solution was transferred to the coupler solution over 30 minutes, and the mixture was stirred for a further 60 minutes to effect coupling, thereby obtaining a suspension of an azo pigment composition. The suspension was heated to 80°C over 90 minutes and then cooled to 70°C to obtain a slurry containing pigment composition (1). The slurry was filtered through a Nutsche filter and washed with 18,200 parts of water to obtain a wet cake. The wet cake was dried in a dryer at 80°C for 24 hours, pulverized, and passed through an 80-mesh wire screen to obtain 935 parts of pigment composition (1).

[0041] Example 2 Preparation of pigment composition (2) In the same manner as in Example 1, except that the amounts of 35% calcium chloride and barium chloride dihydrate were changed to 587 parts and 90 parts, respectively, 952 parts of pigment composition (2) were obtained.

[0042] Example 3 Preparation of pigment composition (3) In the same manner as in Example 1, except that the amounts of 35% calcium chloride and barium chloride dihydrate were changed to 469 parts and 181 parts, respectively, 985 parts of pigment composition (3) were obtained.

[0043] Example 4 Preparation of pigment composition (4) The same procedure as in Example 1 was carried out except that 26 parts of turmeric oil was not added, to obtain 909 parts of pigment composition (4).

[0044] Example 5 Preparation of pigment composition (5) The same procedures as in Example 1 were carried out up to the step of obtaining a suspension of an azo pigment composition. The obtained suspension was heated to 60°C over 60 minutes to obtain a slurry containing pigment composition (5). This slurry was filtered through a Nutsche filter and washed with 18,200 parts of water to obtain a wet cake. This wet cake was dried in a dryer at 80°C for 24 hours, pulverized, and passed through an 80-mesh wire screen to obtain 935 parts of pigment composition (5).

[0045] Example 6 Preparation of pigment composition (6) The same procedures as in Example 1 were carried out up to the step of obtaining a suspension of an azo pigment composition. Thereafter, the suspension of the azo pigment composition was heated to 90°C over 90 minutes and then cooled to 70°C to obtain a slurry containing pigment composition (6). This slurry was filtered through a Nutsche filter and washed with 18,200 parts of water to obtain a wet cake. This wet cake was dried in a dryer at 80°C for 24 hours, pulverized, and passed through an 80-mesh wire screen to obtain 935 parts of pigment composition (6).

[0046] Example 7 Preparation of pigment composition (7) In Example 1, no fungus oil was added during the preparation of the coupler solution. Instead, 116 parts of Diplodin K-25 (manufactured by Toho Chemical Industry Co., Ltd.) as a rosin was added to the suspension of the azo pigment composition and stirred for 10 minutes. The temperature was then raised to 80°C over 90 minutes and then cooled to 70°C to obtain a slurry containing pigment composition (7). This slurry was filtered through a Nutsche filter and washed with 18,200 parts of water to obtain a wet cake. This wet cake was dried in a dryer at 80°C for 24 hours, pulverized, and passed through an 80-mesh wire screen to obtain 934 parts of pigment composition (7).

[0047] Example 8 Preparation of pigment composition (8) In the same manner as in Example 7, except that the amount of Diplodin K-25 (manufactured by Toho Chemical Industry Co., Ltd.) was changed to 270 parts, 970 parts of pigment composition (8) was obtained.

[0048] Example 9 Preparation of pigment composition (9) 495 parts of sodium 4-amino-2-chlorotoluene-5-sulfonate was added to 1,700 parts of water and stirred, after which 308 parts of 35% hydrochloric acid was added to precipitate the mixture, and 1,100 parts of ice was added to bring the liquid temperature to 0° C. Further, 350 parts of a 40% aqueous sodium nitrite solution was added, and water was added so that the total amount became 7,000 parts, followed by stirring at 0° C. for 60 minutes to obtain a diazo solution.

[0049] In a separate vessel, 3,000 parts of water, 380 parts of 3-hydroxy-2-naphthalenecarboxylic acid, and 700 parts of a 25% aqueous sodium hydroxide solution were added and stirred to dissolve. 4,500 parts of water was added, the temperature was adjusted to 15°C, and water was added so that the total amount became 11,200 parts, to obtain a coupler solution.

[0050] The diazo solution was transferred to the coupler solution over 30 minutes, and the mixture was stirred for a further 60 minutes to effect coupling, thereby obtaining a suspension of an azo dye.

[0051] This suspension was heated to 50°C, 650 parts of 35% calcium chloride was added, and the mixture was stirred for 10 minutes. 42 parts of barium chloride dihydrate was then added and stirred for 10 minutes. The suspension was then heated to 90°C over 60 minutes and then cooled to 70°C. 37 parts of PELLEX OT-P (Kao Corporation, sodium dialkyl sulfosuccinate) were added and the mixture was stirred for 10 minutes to obtain a slurry containing pigment composition (9). This slurry was filtered through a Nutsche filter and washed with 18,200 parts of water to obtain a wet cake. This wet cake was dried in a dryer at 80°C for 24 hours, pulverized, and passed through an 80-mesh wire mesh to obtain 971 parts of pigment composition (9).

[0052] Example 10 Preparation of pigment composition (10) In Example 9, the same procedure was conducted except that the temperature of the azo dye suspension was raised to 65°C instead of 50°C, to obtain 971 parts of pigment composition (10).

[0053] Example 11 Preparation of pigment composition (11) In Example 9, the same procedure was conducted as in Example 9, except that the temperature of the azo dye suspension was increased to 80°C instead of 50°C, to obtain 971 parts of pigment composition (11).

[0054] Example 12 Preparation of pigment composition (12) Pigment composition (12) was obtained in the same manner as in Example 1, except that 450 parts of 2-amino-5-chloro-4-methylbenzenesulfonic acid was added instead of 380 parts of 4-aminotoluene-3-sulfonic acid, the amount of 35% calcium chloride aqueous solution was changed from 650 parts to 335 parts, and the amount of barium chloride dihydrate was changed from 42 parts to 14 parts, 291 parts of 2-naphthol was added instead of 380 parts of 3-hydroxy-2-naphthalenecarboxylic acid, and 26 parts of Demol N (sodium salt of naphthalenesulfonic acid formalin condensate, manufactured by Kao Corporation) was added as a surfactant instead of 26 parts of turpentine oil.

[0055] Example 13 Preparation of pigment composition (13) 380 parts of 4-aminotoluene-3-sulfonic acid was added to 1,700 parts of water and stirred, and then 308 parts of 35% hydrochloric acid was added to precipitate the mixture, and 1,100 parts of ice was added to bring the liquid temperature to 0° C. Further, 350 parts of a 40% aqueous sodium nitrite solution was added, and water was added so that the total amount became 7,000 parts, and the mixture was stirred at 0° C. for 60 minutes to obtain a diazo solution.

[0056] In a separate vessel, 3,000 parts of water, 380 parts of 3-hydroxy-2-naphthalenecarboxylic acid, and 700 parts of a 25% aqueous sodium hydroxide solution were added and stirred to dissolve. 4,500 parts of water and 26 parts of fungus oil were added, and the mixture was heated to 15°C. Water was added so that the total amount became 11,200 parts, to obtain a coupler solution.

[0057] The diazo solution was transferred to the coupler solution over 30 minutes, and the mixture was stirred for a further 60 minutes to obtain a suspension of the azo dye.

[0058] To this suspension, 650 parts of 35% calcium chloride was added and stirred for 10 minutes, and then 42 parts of barium chloride was added and stirred for 10 minutes. The suspension was then heated to 80°C over 90 minutes and then cooled to 70°C to obtain a slurry containing pigment composition (13). This slurry was filtered through a Nutsche filter and washed with 18,200 parts of water to obtain a wet cake. This wet cake was dried in a dryer at 80°C for 24 hours, pulverized, and passed through an 80-mesh wire screen to obtain 935 parts of pigment composition (13).

[0059] Example 14 Preparation of pigment composition (14) In the same manner as in Example 9, 37 parts of Pelex OT-P were replaced with 26 parts of turmeric oil, to obtain 971 parts of pigment composition (14).

[0060] (Comparative Example 1) Preparation of pigment composition (15) In the same manner as in Example 1, except that 650 parts of 35% calcium chloride was not added and the amount of barium chloride dihydrate was changed from 42 parts to 542 parts, 1,087 parts of pigment composition (15) was obtained.

[0061] (Comparative Example 2) Preparation of pigment composition (16) In the same manner as in Example 14, except that 650 parts of 35% calcium chloride was not added and the amount of barium chloride dihydrate was changed from 42 parts to 542 parts, 1,185 parts of pigment composition (16) was obtained.

[0062] (Comparative Example 3) Preparation of pigment composition (17) In the same manner as in Comparative Example 1, except that 542 parts of barium chloride dihydrate was changed to 704 parts of a 35% aqueous calcium chloride solution, 920 parts of pigment composition (17) was obtained.

[0063] Comparative Example 4 Preparation of pigment composition (18) In the same manner as in Comparative Example 2, except that 542 parts of barium chloride dihydrate was changed to 704 parts of a 35% aqueous calcium chloride solution, 953 parts of pigment composition (18) was obtained.

[0064] (Comparative Example 5) Preparation of pigment composition (19) In Comparative Example 3, 1,028 parts of pigment composition (19) was obtained in the same manner as in Comparative Example 3, except that no fungus oil was added when preparing the coupler solution, and 568 parts of Diplodin K-25 (manufactured by Toho Chemical Industry Co., Ltd.) was added to the suspension of the azo pigment composition after coupling and stirred for 10 minutes.

[0065] (Comparative Example 6) Preparation of pigment composition (20) In Comparative Example 4, 1,066 parts of pigment composition (20) was obtained in the same manner as in Comparative Example 4, except that no fungus oil was added when preparing the coupler solution, and 589 parts of Diplodin K-25 (manufactured by Toho Chemical Industry Co., Ltd.) was added to the suspension of the azo pigment composition after coupling and stirred for 10 minutes.

[0066] Table 1 shows details of the pigment compositions prepared in Examples 1 to 14 and Comparative Examples 1 to 6. [Table 1]

[0067] Calculation of azo dyes in pigment compositions For the pigment compositions (1) to (20) obtained in Examples 1 to 14 and Comparative Examples 1 to 6, the content of the azo dye remaining in each pigment composition was determined using liquid chromatography according to the method described below. (extraction method) Preparation of standard samples 6.0 mg of pigment composition (1), (9), or (12) was completely dissolved in 30 ml of dimethylformamide (DMF), filtered through a 0.2 μm filter, and used as a measurement sample. Furthermore, the three measurement samples obtained were diluted 10 times, 20 times, and 30 times to prepare samples. Preparation of test samples 300 mg of pigment composition (1), 30 ml of water, and 75 g of 0.3 mm zirconia beads were placed in a 75 cc mayonnaise bottle and dispersed for 2 hours at 172 rpm using a paint shaker (SK450 manufactured by Fast & Fluid). The resulting dispersion was centrifuged for 30 minutes at 9,500 rpm using a Cectrifuge 5810 (manufactured by Eppendorf). The supernatant after centrifugation was filtered through a 0.2 μm filter to prepare a measurement sample. Measurement samples were also prepared in the same manner for pigment compositions (2) to (20). (Analysis method) The azo dye in the measurement sample was quantified using liquid chromatography (LC-MS) under the following conditions: The same quantitative analysis was repeated twice, and the average value was calculated and converted into the content in the pigment composition. Apparatus: Liquid chromatography Xevo TQD (Waters) Column: Symmetry C18 180 mm x 2.1 mm 5 μm (Waters) Temperature: 35℃ Flow rate: 0.4ml / min Measurement sample injection volume: 10 μL Column: Symmetry C18 particle size 5 μm, column length 2.1 × 150 mm Detector: 996PDA Wavelength: 520nm Eluent: (A) 50 mM ammonium acetate aqueous solution / DMF = 7 / 1, (B) DMF

[0068] [Table 2]

[0069] Preparation of calibration curves: The horizontal axis represents the mass-to-volume ratio concentration (mg / L) of pigment compositions (1), (9), and (12) in the standard samples, and the vertical axis represents the peak area corresponding to the azo dye measured by LC-MS. The amount of dye component for each corresponding CI No. was calculated from the calibration curve and the peak area corresponding to the azo dye in the test sample. Specifically, the amount of dye component in pigment compositions (1) to (8), (13), and comparative examples (1), (3), and (5) was calculated using the calibration curve for standard sample (R57) in which pigment composition (1) was dissolved. The amount of dye component in pigment compositions (9) to (11), (14), and comparative examples (2), (4), and (6) was calculated using the calibration curve for standard sample (R48) in which pigment composition (9) was dissolved. The amount of dye component in pigment composition (12) was calculated using the calibration curve for the same sample. Table 3 shows the pigment composition number in the standard sample corresponding to each pigment composition and the mass % of the residual azo dye in each sample.

[0070] [Table 3]

[0071] [Example 101] Preparation of solvent-based gravure ink for lamination (1) 30 parts of the pigment composition (1) obtained in Example 1, 30 parts of binder resin solution BD1 (30% nonvolatile content), 5.0 parts of vinyl chloride-vinyl acetate copolymer resin (Nissin Chemical Industry Co., Ltd., Solbin TAO vinyl chloride:vinyl acetate:vinyl alcohol = 91:2:7 (mass ratio) (30% nonvolatile content ethyl acetate solution)), and 29 parts of a 70 / 30 n-propyl acetate / IPA solution were mixed and dispersed in an Eiger mill for 20 minutes. Subsequently, while stirring with a disperser, 3.0 parts of ethylene glycol monomethyl ether and 3.0 parts of water were added to obtain solvent-based gravure ink for lamination (1).

[0072] [Examples 102 to 114, Comparative Examples 101 to 106] Preparation of solvent-based gravure inks for lamination (2) to (20) Solvent-based gravure inks for lamination (2) to (20) were obtained in the same manner as in Example 101, except that the pigment compositions were changed as shown in Table 4.

[0073] [Table 4]

[0074] [Example 201] - Creation of printed matter (1) The resulting solvent-based laminating gravure ink (1) was diluted with a mixed solvent (methyl ethyl ketone:n-propyl acetate:IPA=40:40:20) to a viscosity of 16 seconds (25°C, Zahn cup No. 3), and printed using a Helio 175 line gradation plate (compressed plate type, 100% to 3% gradation pattern) on the corona-discharge-treated surface of a 12 μm-thick corona-discharge-treated polyester (PET) film (Toyobo E-5100) at a printing speed of 150 m / min to obtain printed matter (1). The printing conditions were a temperature of 32°C, a humidity of 80%, and a printing distance of 4000 m.

[0075] [Examples 202 to 214, Comparative Examples 201 to 206] - Creation of printed materials (2) to (20) Printed materials (2) to (20) were obtained in the same manner as in Example 201, except that the solvent-based laminating gravure ink was changed as shown in Table 5.

[0076] ·Transparency The printed materials (1) to (20) were visually observed and evaluated for transparency according to the following criteria. The results are shown in Table 5. The standard printed material was (17). If the evaluation result was "◎" or "○", the material was usable. ◎: Extremely higher transparency than the standard print. ○: Higher transparency than the reference print. △: Transparency is equivalent to that of the reference print. X: Less transparent than the reference print.

[0077] Color development The printed matter (1) to (20) were visually observed and evaluated for color development according to the following criteria. The results are shown in Table 5. The standard printed matter was (17). If the evaluation result was "◎" or "○", it was usable. ◎: Color development is much higher than the standard print. ○: Higher color development than the reference print. △: Color development is equivalent to that of the reference print. X: Lower color development than the standard print [Table 5]

[0078] [Example 301] - Preparation of packaging materials (1) For the obtained printed matter (1), a polyether urethane laminating adhesive (TM 320 / CAT13B manufactured by Toyo Morton Co., Ltd.) was further diluted with an ethyl acetate solution with a non-volatile content of 30% by weight, and the coating amount after drying was 2.0 g / m 2 This was then laminated with aluminum-deposited unstretched polypropylene (VMCP2203, film thickness 25 μm, manufactured by Toray Advanced Film Co., Ltd.) and dry-laminated at 50°C to obtain packaging material (1). Evaluation was carried out after aging the packaging material at 50°C for 48 hours.

[0079] [Examples 302 to 314, Comparative Examples 301 to 306] - Preparation of packaging materials (2) to (20) Packaging materials (2) to (20) were obtained in the same manner as in Example 301, except that the printed matter was changed as shown in Table 6. The evaluation was carried out after the packaging materials were kept at 50°C for 48 hours.

[0080] <Evaluation of laminate strength> The printed portion of each of the resulting packaging materials (1) to (20) was cut to a width of 15 mm, and the peel strength (lamination strength) was measured at a peel rate of 300 mm / min using an Intesco 201 universal tensile tester in an atmosphere of 20°C and 65% humidity. The practical level is 0.7 N / 15 mm or higher. The results are shown in Table 6. Materials with an evaluation score of "◎", "○", or "△" are usable. Even if the laminate strength evaluation is within the usable range, materials outside the usable range for the transparency and color development evaluations shown in Table 5 are unusable. ◎ The laminate strength is 1.0N / 15mm or more. 〇···Laminate strength is 0.85N / 15mm or more and less than 1.0N / 15mm. △···The laminate strength is 0.7N / 15mm or more and less than 0.85N / 15mm. X... The laminate strength is less than 0.7N / 15mm.

[0081] <Boiling retort test> The packaging materials (1) to (20) obtained in Examples 301 to 314 and Comparative Examples 301 to 306 were formed into pouches measuring 120 mm x 120 mm, and 70 g of a food imitation containing vinegar, salad oil, and meat sauce in a 1:1:1 weight ratio was filled and sealed. The pouches were subjected to steam retort sterilization at 135°C for 30 minutes, and the degree of ink layer peeling was evaluated on a three-point scale. The results are shown in Table 6. Evaluation results of "◎" and "○" indicate usability. Even if the material was within the usable range in the boiling retort test, it was unusable if it was outside the usable range in the transparency and color development evaluations shown in Table 5. ⊚: No peeling at all. ○: There is a very small amount of small blister-like peeling. ×: Large and small peeling is observed over the entire surface.

[0082] [Table 6]

Claims

1. 1. A pigment composition comprising: The present invention comprises an azo lake pigment (B1) which is a lake reaction product of the azo dye (A) with calcium, and an azo lake pigment (B2) which is a lake reaction product of the azo dye (A) with barium, A pigment composition, wherein the content of the azo dye (A) in the pigment composition is 0% by mass or more and 1% by mass or less.

2. 2. The pigment composition according to claim 1, wherein the azo dye (A) is a compound represented by the following chemical formula (1) or (2): 【Chemical 1】

3. The pigment composition according to claim 1, wherein the average primary particle size is 80 nm or more and 500 nm or less.

4. The pigment composition according to claim 1 , wherein the rosin content in the pigment composition is 0% by mass or more and 10% by mass or less.

5. The pigment composition of claim 1 , further comprising a surfactant.

6. A method for producing the pigment composition according to any one of claims 1 to 5, comprising the steps of mixing a diazonium salt of an aromatic amine having a solubilizing group with a calcium metal salt and a barium metal salt, and then subjecting the resulting mixture to a coupling reaction with a coupler component.

7. 6. A method for producing the pigment composition according to claim 1, comprising the step of adding a calcium metal salt and a barium metal salt to the azo dye (A) to carry out a laking reaction.

8. A printing ink comprising the pigment composition according to any one of claims 1 to 5.

9. A printed matter having an ink layer formed from the printing ink according to claim 8.

10. A packaging material comprising the printed matter according to claim 9.

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