Inkjet ink and ink set

Abstract

The present invention addresses the problem of providing an inkjet ink which has excellent removability, that is, from which the colorant can be easily removed.　Specifically, the inkjet ink contains a colorant, wherein the colorant is one or more substances selected from the group consisting of iron oxide compounds, phycocyanin, caramel, copper-chlorophyllin compounds, capsaicin, carminic acid, betanin, cyanidin glycosides, carmine, β-carotene, lutein, norbixin, and curcumin.

Description

Inkjet inks and ink sets

[0001] The present invention relates to inkjet inks and ink sets.

[0002] Coal-tar dyes are often used in foods with vivid colors, and have been used in a wide range of foods, including sweets such as sweet breads, chocolates, jellies, and gum, as well as pickles such as pickled radish and red pickled ginger. Based on this background, methods for inhibiting the fading of tar dyes have been investigated (Patent Document 1). Furthermore, their uses are diverse, including printing inks on foods for oral administration products.

[0003] International Publication No. 2005 / 108503 Pamphlet Japanese Patent Application Laid-Open No. 2000-42089

[0004] However, some of the colorants used in food, including tar colorants, have concerns about the color remaining on the tongue. In addition, colorants derived from fossil fuels (petroleum, coal), such as tar colorants, are difficult to remove from printed materials, making it difficult to recycle the base material. Therefore, they are often incinerated as garbage, resulting in CO2 emissions. ２ From the viewpoint of cost reduction, there are also undesirable aspects. Therefore, an object of the present invention is to provide an inkjet ink that is excellent in deinking properties, that is, an inkjet ink from which the dye can be easily removed.

[0005] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by using an inkjet ink containing a specific dye, and have thus completed the present invention. An example of the configuration of the present invention that solves the above-mentioned problems is as follows.

[0006] Item 1. An ink-jet ink containing a dye, wherein the dye is one or more selected from the group consisting of iron oxide compounds, phycocyanin, caramel, copper chlorophyllins, capsaicin, carminic acid, betanin, cyanidin glycosides, carmine, β-carotene, lutein, norbixin, and curcumin.

[0007] Item 2. The iron oxide compound is triiron tetroxide (Fe ３ O４ ), iron trioxide (Fe ２ O ３ Item 2. The ink-jet ink according to Item 1, wherein the inorganic filler is one or more selected from the group consisting of iron oxyhydroxide (FeOOH) and iron oxyhydroxide (FeOOH).

[0008] Item 3. The ink-jet ink according to item 1 or 2, further comprising a solvent.

[0009] Item 4. The ink-jet ink according to any one of Items 1 to 3, further comprising a binder resin.

[0010] Item 5. The ink-jet ink according to any one of items 1 to 4, further comprising a surfactant.

[0011] Item 6. The ink-jet ink according to any one of items 1 to 5, further comprising water.

[0012] Item 7. The ink-jet ink according to any one of items 1 to 6, which is used for food, cardboard, food packaging, or textiles.

[0013] Item 8. An ink set comprising the inkjet ink according to any one of items 1 to 7.

[0014] According to the present invention, an inkjet ink having good ejection properties and deinking properties can be provided. Since the inkjet ink according to the present invention has good deinking properties, it is expected that the substrate can be recycled, and a reduction in the environmental load can be expected, making it eco-friendly. Furthermore, when applied to food, it is expected that the color residue on the tongue can be reduced.

[0015] (Inkjet ink) The inkjet ink according to the present invention is a composition containing a dye, characterized in that the dye is one or more selected from the group consisting of iron oxide compounds, phycocyanin, caramel, copper chlorophyllins, capsaicin, carminic acid, betanin, cyanidin glycosides, carmine, β-carotene, lutein, norbixin, and curcumin.

[0016] The iron oxide compound includes iron trioxide (Fe ３ O ４ ), iron trioxide (Fe ２O ３ It is preferable that the inorganic filler is one or more selected from the group consisting of iron oxyhydroxide (FeOOH) and iron oxyhydroxide (FeOOH).

[0017] The pigments may be extracted from natural products, processed from natural extracts, synthesized from raw materials derived from natural products, or artificially chemically synthesized, but from the viewpoint of eco-friendliness, those extracted from natural products, processed from natural extracts, or synthesized from raw materials derived from natural products, i.e., natural pigments, are preferred. Furthermore, from the viewpoint of solubility and dispersibility, the pigments may be subjected to lake treatment or resin treatment to the extent that the required properties are not impaired.

[0018] For example, the dye can be contained in the inkjet ink by using a colorant containing the dye. The colorant is preferably in the form of a powder or liquid.

[0019] For example, the colorants that can be used in the inkjet ink according to the present invention include the following: "SUNFOODS (trademark) Black Iron Oxide (dye: triiron tetroxide (Fe ３ O ４ ), Shape: Powder, Color Space: Black)" - "SUNFOODS (trademark) Red Iron Oxide (Pigment: Diiron Trioxide (Fe ２ O ３), form: powder, color space: red)" - "SUNFOODS (trademark) Yellow Iron Oxide (pigment: iron oxyhydroxide (FeOOH), form: powder, color space: yellow)" - "LINABLUE (registered trademark) Blue spirulina extract (pigment: phycocyanin, form: powder or liquid, color space: blue)" - "SUNFOODS (trademark) Natural Caramel (pigment: caramel, form: liquid, color space: brown)" - "SUNFOODS (trademark) Chlorophyllin (pigment: copper chlorophyllins, form: powder or liquid, color space: green)" - "SUNFOODS (trademark) Paprika (pigment: capsaicin, form: powder or liquid, color space: orange) - SUNFOODS (trademark) Cochineal (pigment: carminic acid, form: powder or liquid, color space: orange) - SUNFOODS (trademark) Beet (pigment: betanin, form: powder or liquid, color space: red) - SUNFOODS (trademark) Anthocyanin (pigment: cyanidin glycoside, form: powder or liquid, color space: red to purple) - SUNFOODS (trademark) Carmine (pigment: carmine, form: liquid, color space: red) - SUNFOODS (trademark) Natural White (pigment: β-carotene, form: powder or liquid, color space: white) - "SUNFOODS (trademark) Beta Carotene (pigment: β-carotene, form: powder or liquid, color space: yellow)" - "SUNFOODS (trademark) Natural Beta Carotene (pigment: β-carotene, form: liquid, color space: yellow)" - "SUNFOODS (trademark) Lutein (pigment: lutein, form: liquid, color space: yellow)" - "SUNFOODS (trademark) Annatto (pigment: nobiluxin, form: powder, color space: yellow)" - "SUNFOODS (trademark) Turmeric (pigment, curcumin, form: powder, color space: yellow)"

[0020] The type of dye (colorant) used in the inkjet ink (composition) is preferably one or more types. The colorant is preferably used so that the content of the dye contained in the colorant is a predetermined content in the inkjet ink. The lower limit of the total content of the dyes in 100% by mass of the inkjet ink (composition) is preferably 1.0% by mass or more, and preferably 3.0% by mass or more. The upper limit of the total content of the dyes in 100% by mass of the inkjet ink (composition) is preferably 15.0% by mass or less, and preferably 10.0% by mass or less. The total content of the dyes in 100% by mass of the inkjet ink (composition) is preferably 1.0 to 15.0% by mass, and preferably 3.0 to 10.0% by mass.

[0021] (Other Components) The inkjet ink according to the present invention preferably contains a solvent from the viewpoints of compatibility with the dye and moisture retention.

[0022] Examples of the solvent include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol having a molecular weight of 2000 or less, propylene glycol, dipropylene glycol, tripropylene glycol, isopropylene glycol, isobutylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 1,2-hexanediol, 1,6-hexanediol, mesoerythritol, pentaerythritol, glycerin, and ethylene urea.

[0023] The type of solvent used in the inkjet ink (composition) is preferably one or more types, and preferably one to three types. The lower limit of the total content of the solvents in 100% by mass of the inkjet ink (composition) is preferably 1.0% by mass or more, preferably 10.0% by mass or more, and preferably 15.0% by mass or more. The upper limit of the total content of the solvents in 100% by mass of the inkjet ink (composition) is preferably 45.0% by mass or less, preferably 35.0% by mass or less, and preferably 25.0% by mass or less. The total content of the solvents in 100% by mass of the inkjet ink (composition) is preferably 1.0 to 45.0% by mass, preferably 10.0 to 35.0% by mass, and preferably 15.0 to 25.0% by mass.

[0024] The ink-jet ink according to the present invention preferably contains a binder resin from the viewpoint of abrasion resistance and fixability.

[0025] Examples of binder resins include polyvinyl alcohol, gelatin, polyethylene oxide, polyvinylpyrrolidone, acrylic resins, urethane resins, olefin resins, modified polyolefin resins (such as acid-modified polypropylene), dextran, dextrin, carrageenan (κ, ι, λ, etc.), agar, pullulan, water-soluble polyvinyl butyral, hydroxyethyl cellulose, and carboxymethyl cellulose. From the viewpoint of weather resistance, styrene-acrylic resins and the like are preferred.

[0026] The weight average molecular weight (Mw) of the binder resin is preferably 50,000 to 1,000,000, more preferably 50,000 to 500,000, and even more preferably 50,000 to 250,000. The Mw of the binder resin is a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene. Specifically, it was determined by a GPC-MALS method using a multi-angle light scattering detector connected to GPC under the measurement conditions described below. GPC main body: "LC1100" series manufactured by Agilent Technologies Column: "SHODEX SB806MHQ" manufactured by Showa Denko K.K. Eluent: N / 3 phosphate buffer (pH 3) containing N / 10 sodium nitrate Flow rate: 1.0 ml / min Detector 1: DAWN multi-angle light scattering detector manufactured by Wyatt Technology Detector 2: RI-101 differential refractive index detector manufactured by Showa Denko K.K.

[0027] The acid value of the binder resin is preferably 10 to 200 mgKOH / g, more preferably 50 to 150 mgKOH / g, from the viewpoint of dispersibility and fixability. The acid value can be measured in accordance with JIS standard K2501.

[0028] The glass transition temperature (Tg) of the binder resin is preferably 20 to 100° C., and more preferably 50 to 100° C. The glass transition temperature (Tg) can be measured in accordance with JIS standard K7121.

[0029] Examples of binder resins include "JONCRYL PDX-7696," "JONCRYL PDX-7700," "JONCRYL PDX-7780," "JONCRYL 89-E," and "JONCRYL 89J" (all trade names (JONCRYL is a registered trademark) manufactured by BASF Japan Ltd.), "Hi-Loss X BE7503" (manufactured by Seiko PMC Corporation), "Vinyblan 745," and "Vinyblan 747" (manufactured by Nissin Chemical Industry Co., Ltd.).

[0030] The type of binder resin used in the inkjet ink (composition) is preferably one or two or more types. The lower limit of the total content of the binder resin in 100% by mass of the inkjet ink (composition) is preferably 0.1% by mass or more, preferably 0.5% by mass or more, and preferably 1.0% by mass or more. The upper limit of the total content of the binder resin in 100% by mass of the inkjet ink (composition) is preferably 5.0% by mass or less, preferably 4.0% by mass or less, and preferably 3.0% by mass or less. From the viewpoints of jetting property and abrasion resistance, the total content of the binder resin in 100% by mass of the inkjet ink (composition) is preferably 0.1 to 5.0% by mass, preferably 0.5 to 4.0% by mass, and preferably 1.0 to 3.0% by mass.

[0031] The ink-jet ink according to the present invention preferably contains a surfactant from the viewpoint of imparting substrate wettability.

[0032] Examples of surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, but from the viewpoint of ink storage stability, anionic surfactants or nonionic surfactants are preferred. Examples of anionic surfactants include alkylbenzenesulfonates, alkylphenylsulfonates, alkylnaphthalenesulfonates, higher fatty acid salts, sulfate ester salts or sulfonates of higher fatty acid esters, sulfate ester salts or sulfonates of higher alcohol ethers, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, sulfates, phosphates, and alkyl phosphates of polyoxyethylene alkyl ethers.

[0033] Examples of nonionic surfactants include glycol surfactants, silicone surfactants, fluorine surfactants, and acetylene diol surfactants.

[0034] Examples of glycol surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyglycerin fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty acid amides, and polyoxyethylene-polyoxypropylene block copolymers.

[0035] Examples of silicone surfactants include polysiloxane compounds, polyether-modified organosiloxanes, etc. Examples of commercially available silicone surfactants include the "TegoWet (registered trademark)" series manufactured by Evonik, the "BYK (registered trademark)" series manufactured by BYK Japan, and the "KF" series manufactured by Shin-Etsu Chemical Co., Ltd.

[0036] Examples of fluorine-based surfactants include perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, oxyethylene perfluoroalkyl ethers, perfluoroalkyl phosphates, perfluoroalkyl betaines, perfluoroalkyl amine oxides, etc. Examples of commercially available fluorine-based surfactants include the "Megafac (registered trademark)" series manufactured by DIC Corporation, the "Ftergent (registered trademark)" series manufactured by Neos Corporation, and the "Novec (registered trademark)" series manufactured by Sumitomo 3M Limited.

[0037] Acetylene diol surfactants are surfactants having a carbon-carbon triple bond in the molecule, and examples thereof include acetylenic diol (having an acetylene bond and two hydroxyl groups in the same molecule) surfactants and surfactants in which alkylene oxides such as ethylene oxide and propylene oxide are added to acetylenic diol. Examples of acetylenic diol surfactants include alkylene oxide adducts of 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 2,4,7,9-tetramethyl-5-decyne-4,7-diol, and alkylene oxide adducts of 2,4-dimethyl-5-decyne-4-ol and 2,4-dimethyl-5-decyne-4-ol. Commercially available acetylenic diol surfactants include, for example, the "Surfynol (registered trademark)" series manufactured by Evonik or Nissin Chemical Industry Co., Ltd., the "Olfine (registered trademark)" series manufactured by Nissin Chemical Industry Co., Ltd., and the "Acetylenol (registered trademark)" series manufactured by Kawaken Fine Chemicals Co., Ltd.

[0038] From the viewpoint of ink interface control, the HLB value of the surfactant is preferably 2.5 to 10.0, more preferably 3.0 to 9.0, and even more preferably 3.5 to 6.0. The "HLB (Hydrophilic-Lipophilic Balance) value" of the surfactant is a value defined by the Griffin method using the following calculation formula (Griffin formula): HLB value = 20 x [total chemical formula weight of hydrophilic moieties] / molecular weight

[0039] The type of surfactant used in the inkjet ink (composition) is preferably one or more types, and preferably one to two types. The lower limit of the total content of the surfactants in 100% by mass of the inkjet ink (composition) is preferably 0.01% by mass or more, preferably 0.05% by mass or more, and preferably 0.1% by mass or more. The upper limit of the total content of the surfactants in 100% by mass of the inkjet ink (composition) is preferably 2.0% by mass or less, preferably 1.5% by mass or less, and preferably 1.2% by mass or less. From the viewpoint of substrate wettability, the total content of the surfactants in 100% by mass of the inkjet ink (composition) is preferably 0.01 to 2.0% by mass, preferably 0.05 to 1.5% by mass, and preferably 0.1 to 1.2% by mass.

[0040] From the viewpoint of safety and environmental protection, the inkjet ink according to the present invention is preferably an aqueous ink (containing water).

[0041] Examples of water include distilled water and ion-exchanged water.

[0042] The type of water used in the inkjet ink (composition) is preferably one or more types. The lower limit of the total content of water in 100% by mass of the inkjet ink (composition) is preferably 40.0% by mass or more, preferably 45.0% by mass or more, and preferably 50.0% by mass or more. The upper limit of the total content of water in 100% by mass of the inkjet ink (composition) is preferably 75.0% by mass or less, preferably 70.0% by mass or less, and preferably 65.0% by mass or less. From the viewpoints of jetting performance and colorant stability, the total content of water in 100% by mass of the inkjet ink (composition) is preferably 40.0 to 75.0% by mass, preferably 45.0 to 70.0% by mass, and preferably 50.0 to 65.0% by mass.

[0043] In addition to the components described above, the inkjet ink according to the present invention may further contain other additives, such as a pH adjuster, a preservative, a polyolefin wax, an antioxidant, a viscosity adjuster, a humectant (a drying inhibitor), a penetrating agent, a chelating agent, a plasticizer, and an ultraviolet absorber, as necessary.

[0044] Examples of pH adjusters include potassium dihydrogen phosphate, disodium hydrogen phosphate, sodium hydroxide, lithium hydroxide, potassium hydroxide, ammonia, diethanolamine, triethanolamine, triisopropanolamine, potassium carbonate, sodium carbonate, and sodium hydrogen carbonate.

[0045] Examples of preservatives include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazolin-3-one, etc. Commercially available preservatives may also be used, such as "ACTICIDE (registered trademark) B20" (trade name, manufactured by Thor Japan Co., Ltd.) and "Proxel (registered trademark) GXL" (trade name, manufactured by SC Johnson).

[0046] Polyolefin waxes are waxes or copolymers produced from olefins such as ethylene, propylene, and butylene, or derivatives thereof. Examples of polyolefin waxes include polyethylene waxes, polypropylene waxes, polybutylene waxes, and modified waxes thereof. Among these, oxidized polyethylene wax, which is obtained by oxidatively modifying polyethylene wax, is preferred from the viewpoint of improving the image fastness of printed matter. Commercially available polyolefin waxes may be used, such as the "AQUACER (registered trademark)" series (manufactured by BYK Japan).

[0047] Examples of the antioxidant include phenol-based antioxidants, amine-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants.

[0048] The type of additive used in the inkjet ink (composition) is preferably one or two or more types. The lower limit of the total content of the additives in 100% by mass of the inkjet ink (composition) is preferably 0.01% by mass or more, and preferably 0.02% by mass or more. The upper limit of the total content of the additives in 100% by mass of the inkjet ink (composition) is preferably 5.0% by mass or less, and preferably 3.0% by mass or less. From the viewpoint of ejection performance, the total content of the additives in 100% by mass of the inkjet ink (composition) is preferably 0.01 to 5.0% by mass, and preferably 0.02 to 3.0% by mass. (Physical Properties of Inkjet Ink)

[0049] The viscosity of the inkjet ink according to the present invention at 25°C is preferably 3.0 to 12.0 mPa·s, more preferably 3.0 to 10.0 mPa·s, and even more preferably 3.0 to 6.0 mPa·s, from the viewpoint of suitability for inkjet heads. The viscosity of the inkjet ink is a value measured, for example, using a cone-plate rotational viscometer equivalent to an E-type viscometer under the following conditions: Measuring device: TVE-25 type viscometer (TVE-25L, manufactured by Toki Sangyo Co., Ltd.) Calibration standard solution: JS20 Measurement temperature: 25°C Rotation speed: 10 to 100 rpm Injection amount: 1200 μL

[0050] From the viewpoint of ejection properties and wettability, the surface tension of the inkjet ink according to the present invention at 25° C. is preferably 24.0 to 35.0 mN / m, and more preferably 24.0 to 30.0 mN / m. The surface tension of the inkjet ink at 25° C. is a value measured by the Wilhelmy method.

[0051] From the viewpoint of influence on components, the pH of the inkjet ink at 25° C. is preferably 6.0 to 10.5, and more preferably 7.5 to 9.0. The pH of the inkjet ink at 25° C. is a value measured by the glass electrode method.

[0052] (Method for Producing Inkjet Ink) The inkjet ink can be produced by a method for producing an inkjet ink that includes at least a step of mixing a dye (colorant), a solvent, a binder resin, a surfactant, and water. The mixing method is not particularly limited, and the above-mentioned components may be mixed all at once or sequentially.

[0053] (Uses of Inkjet Ink) The inkjet ink according to the present invention is suitable for food applications because the pigment component has good deinking properties and there is little residual color. In addition, from the viewpoint of the recyclability of the substrate, the inkjet ink is suitable for cardboard applications, food packaging applications, and textile applications.

[0054] The inkjet ink according to the present invention can also be used as an ink set. For example, an inkjet ink containing phycocyanin as a pigment can be combined with an inkjet ink containing an iron oxide compound, caramel, copper chlorophyllins, capsaicin, carminic acid, betanin, cyanidin glycoside, carmine, β-carotene, lutein, norbixin, or curcumin as a pigment to form an ink set. Furthermore, the inkjet ink may be combined with an inkjet ink containing carbon black or the like as a pigment.

[0055] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0056] 1. Materials used <Coloring agent>

[0057] <Solvent> Glycerin (Gly) Propylene glycol (PG) Ethylene urea <Binder resin> Styrene-acrylic resin (JONCRYL PDX-7696 (PDX-7696), Mw 100,000 to 200,000, acid value 122 mg KOH / g, Tg 86°C, manufactured by BASF) <Surfactant> Acetylene diol surfactant (Surfynol 420 (SF420), manufactured by Evonik, HLB value = 4.0) Silicone surfactant (TegoWet 280 (TegoWet), manufactured by Evonik, HLB value = 3.5) <Water> Ion-exchanged water

[0058] 2. Evaluation of Inkjet Inks <2-1. Dischargeability> Using the inkjet inks obtained in each Example and Comparative Example, an inkjet printer (Epson Corporation, "PX-S270T") was used to continuously print 100 solid patterns on photo paper in an atmosphere of 40°C and 30% RH, and finally a nozzle check pattern was printed. The printing conditions were image resolution: 600 dpi x 600 dpi, print quality: standard in the printing mode, and business plain paper. The obtained nozzle check patterns were visually observed to confirm the presence or absence of nozzle clogging, and the dischargeability was evaluated according to the following criteria. <Evaluation Criteria> ○: No nozzle clogging at all ×: Nozzle clogging occurred <2-2. Deinking Effect> Using the inkjet inks obtained in each Example and Comparative Example, an inkjet printer (Epson Corporation, "PX-S270T") was used to print samples (A4 solid print, 3 sheets) on high-quality paper in an atmosphere of 40°C and 30% RH. The sample was added to a mixer (T-fal Powerix Multi BL42X1JP), and then 700 ml of water at 30°C was added. While gently stirring with a stirring rod, 3 ml of a 3.5% by mass aqueous solution of sodium hydroxide and 0.3 g of DI-7020 (a nonionic surfactant, manufactured by Kao Corporation) were added, and the sample was gently pressed down with the stirring rod and immersed for 1 minute. The mixer was then started, and the mixture was macerated for 3 minutes at a rotation speed of 15,000 rpm. Then, a water-soaked filter paper was attached to a Buchner funnel, and the contents of the mixer were filtered while being aspirated, to obtain a filtrate and a pulp mat. The obtained pulp mat was visually observed, and deinking properties were evaluated. <Evaluation criteria> ○: No coloration ×: Coloration was observed

[0059] (Examples 1 to 25, Comparative Example 1) Preparation of Inkjet Ink 1 The above-mentioned colorant, solvent, binder resin, surfactant, and water were mixed to prepare inkjet inks. The inkjet inks were then evaluated. The results are shown in Tables 2 and 3.

[0060]

[0061]

[0062] From Examples 1 to 25 and Comparative Example 1, it was confirmed that ink-jet inks containing predetermined dyes have excellent ejection properties and deinking properties.

[0063] (Examples 26 to 32, Comparative Example 2) Inkjet ink production 2 Furthermore, after examining the composition of each inkjet ink, inkjet inks were produced by mixing the above-mentioned colorants, solvents, binder resins, surfactants, and water. The inkjet inks were then evaluated, and it was confirmed that they had excellent ejection properties and deinking properties. The results are shown in Tables 4 and 5. In the tables, "other components" refers to components other than the pigment contained in the colorant.

[0064]

[0065]

[0066] The inkjet ink of the present invention has a reduced environmental impact and is easy to deink, so it is expected to be recycled. Furthermore, the inkjet ink of the present invention is useful, for example, as an inkjet ink for food.

Claims

1. An inkjet ink containing a pigment and a binder resin, The ink-jet ink is characterized in that the pigment is one or more selected from the group consisting of phycocyanin, caramel, copper chlorophyllins, capsaicin, carminic acid, betanin, cyanidin glycoside, carmine, β-carotene, lutein, norbixin, and curcumin.

2. An inkjet ink as described in claim 1, wherein the weight average molecular weight (Mw) of the binder resin is 50,000 to 1,000,000.

3. An inkjet ink according to claim 1 or 2, wherein the binder resin is one or more selected from the group consisting of polyvinyl alcohol, gelatin, polyethylene oxide, polyvinylpyrrolidone, acrylic resins, urethane resins, olefin resins, modified polyolefin resins, dextran, dextrin, carrageenan, agar, pullulan, water-soluble polyvinyl butyral, hydroxyethyl cellulose, and carboxymethyl cellulose.

4. The ink-jet ink according to claim 1 or 2, further comprising a solvent.

5. The ink-jet ink according to claim 1 or 2, further comprising a surfactant.

6. The ink-jet ink according to claim 1 or 2, further comprising water.

7. 3. The ink-jet ink according to claim 1, which is used for food, cardboard, food packaging, or textiles.

8. An ink set comprising the inkjet ink according to claim 1 or 2.