Aqueous inkjet ink composition, ink set, and recording method

Abstract

To provide an aqueous ink jet ink composition which has storage stability and can form recorded matter having rubbing fastness.SOLUTION: An aqueous ink jet ink composition contains an organic solvent, resin particles, a plasticizer, and water. The organic solvent has an SP value of 9.5 to 10.5, and is contained in an amount from 1.0 to 10.0 mass% based on the total amount of the ink composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an aqueous inkjet ink composition, an ink set, and a recording method.

Background Art

[0002] The inkjet recording method can record high-definition images with a relatively simple device and has been rapidly developed in various fields. Among them, various studies have been made on the rubbing fastness of printed matter. For example, Patent Document 1 discloses a printing ink for printing inkjet printing, which contains a pigment, a water-dispersible resin, a crosslinking agent, and water, and contains a predetermined amount of a resin having a predetermined film elongation and tensile strength as the water-dispersible resin, and contains a predetermined amount of a blocked isocyanate-based compound as the crosslinking agent.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when a crosslinking agent and a corresponding resin are used in combination from the viewpoint of rubbing fastness as in Patent Document 1, it has been found that the storage stability of the ink composition decreases due to the reactivity of the crosslinking agent.

Means for Solving the Problems

[0005] The present invention is an aqueous inkjet ink composition containing an organic solvent having an SP value of 9.5 to 10.5, resin particles, a plasticizer, and water, and containing 1.0 to 10.0% by mass of the organic solvent based on the total amount of the ink composition.

[0006] The present invention relates to an ink set having the above aqueous inkjet ink composition, a treatment liquid composition containing a resin selected from a polyurethane resin and a polyester resin, and water.

[0007] Furthermore, the present invention relates to a recording method having an ink adhesion step of discharging the above aqueous inkjet ink composition by an inkjet method and adhering it to a recording medium.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. However, the present invention is not limited to this, and various modifications are possible without departing from the gist thereof.

[0009] 1. Aqueous inkjet ink composition The aqueous inkjet ink composition of the present embodiment (hereinafter also simply referred to as "ink composition") contains an organic solvent, resin particles, a plasticizer, and water, and the organic solvent contains an organic solvent having an SP value of 9.5 to 10.5 in an amount of 1.0 to 10.0% by mass based on the total amount of the ink composition.

[0010] As one of the methods for improving the rubbing fastness of conventional pigment printing inks, it is known to form a relatively strong ink coating film on a recording object by using a combination of a crosslinking agent and a corresponding resin. However, by including such reactive components in the ink composition, there arises a problem that the storage stability of the ink composition is rather deteriorated.

[0011] On the other hand, in the present embodiment, by using a plasticizer to improve the film-forming property of the resin particles, even when pigment aggregates adhere to a recording medium such as cloth, the followability of the ink coating film to the recording medium can be improved. As a result, the ink coating film becomes more difficult to break, and the rubbing fastness can be improved. Further, by improving the followability, the texture of the obtained recording object can also be improved.

[0012] In addition, plasticizers tend to be relatively hydrophobic and are difficult to stably dissolve in an aqueous ink composition. In this embodiment, by using an organic solvent having a predetermined SP value, the solubility of the plasticizer in the aqueous ink composition can be improved and the storage stability can be enhanced. Hereinafter, each component of the ink composition of this embodiment will be described in detail.

[0013] 1.1. Organic Solvent The organic solvent that can be used in this embodiment is not particularly limited. For example, it includes glycols, glycol monoethers, glycol diethers, glycol monoesters, glycol diesters, nitrogen-containing solvents, monohydric alcohols, and polyhydric alcohols such as glycerin.

[0014] The glycols are not particularly limited. For example, they include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 2-methylpentane-1,3-diol, 2-methylpentane-1,4-diol, 1,2-hexanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, etc.

[0015] The glycol monoethers are not particularly limited. For example, they include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, etc.

[0016] The glycol ethers are not particularly limited, and examples thereof include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, etc.

[0017] The glycol monoesters are not particularly limited, and examples thereof include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, methoxybutyl acetate, etc.

[0018] The glycol diesters are not particularly limited, and examples thereof include ethylene glycol diacetate, diethylene glycol diacetate, propylene glycol diacetate, dipropylene glycol diacetate, ethylene glycol acetate propionate, ethylene glycol acetate butyrate, diethylene glycol acetate butyrate, diethylene glycol acetate propionate, diethylene glycol acetate butyrate, propylene glycol acetate propionate, propylene glycol acetate butyrate, dipropylene glycol acetate butyrate, dipropylene glycol acetate propionate, etc.

[0019] The nitrogen-containing solvents are not particularly limited, and examples thereof include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, etc.

[0020] The monohydric alcohol is not particularly limited, and examples thereof include alcohols such as methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, 2-butanol, tert-butanol, iso-butanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol.

[0021] The ink composition of this embodiment includes an organic solvent having an SP value of 9.5 to 10.5 among such organic solvents, and can include, if necessary, an organic solvent having an SP value other than this.

[0022] Note that the SP value means the solubility parameter. The SP value is a value introduced by Hildebrand and defined by the regular theory. The SP value of an organic solvent is a value calculated from the evaporation energy and molar volume of atoms and atomic groups according to Fedors described in "Coating Basics and Engineering" (page 53, written by Yuji Harasaki, Processing Technology Research Association). The unit of the SP value in this embodiment is (cal / cm 3 ) 1 / 2 However, it can also be converted to the unit of (J / m 3 ) 1 / 2 by 1 (cal / cm 3 ) 3 = 2.046×10 1 / 2 (J / m 3 ) 1 / 2 .

[0023] The organic solvent with an SP value of 9.5 to 10.5 is not particularly limited. For example, 2-methylpentane-1,3-diol (SP value 10.3), 2-methylpentane-1,4-diol, ethylene glycol monoethyl ether (SP value 10.5), ethylene glycol monobutyl ether (SP value 9.5), diethylene glycol monoethyl ether (SP value 10.2), diethylene glycol monobutyl ether (SP value 10.2), ethylene glycol diacetate (SP value 10.0), etc. can be mentioned. Among these, methylpentane diols such as 2-methylpentane-1,3-diol (SP value 10.3) and 2-methylpentane-1,4-diol are preferred, and 2-methylpentane-1,3-diol is more preferred. By using such an organic solvent with an SP value of 9.5 to 10.5, in addition to rubbing fastness and storage stability, the texture of the resulting recording material and the like tend to be further improved. In particular, the solubility of the plasticizer becomes good, and the storage stability can be made good. These organic solvents may be used alone or in combination of two or more.

[0024] The content of the organic solvent with an SP value of 9.5 to 10.5 is 1.0 to 10.0% by mass, preferably 1.5 to 9.0% by mass, more preferably 2.0 to 8.0% by mass, still more preferably 1.5 to 7.0% by mass, and particularly preferably 1.5 to 3.5% by mass with respect to the total amount of the ink composition. When the content of the organic solvent with an SP value of 9.5 to 10.5 is 1.0% by mass or more, in addition to rubbing fastness and storage stability, the texture of the resulting recording material tends to be further improved. Also, when the content of the organic solvent with an SP value of 9.5 to 10.5 is 10.0% by mass or less, in addition to rubbing fastness and storage stability, the peel resistance of the printing surface tends to be further improved.

[0025] The organic solvents having other SP values are not particularly limited, but for example, water-soluble organic solvents such as glycerin and triethylene glycol are preferable. The SP value of the organic solvents having other SP values is preferably more than 10.5. That is, as the organic solvents having other SP values, it is preferable to use solvents with higher hydrophilicity.

[0026] The content of the organic solvents having other SP values is preferably 5.0 to 25% by mass, more preferably 10 to 20% by mass, and still more preferably 12.5 to 17.5% by mass with respect to the total amount of the ink composition. When the content of the organic solvents having other SP values is within the above range, in addition to the rubbing fastness and storage stability, the peel resistance of the printed surface and the texture of the recording material tend to be further improved.

[0027] Also, the total content of the organic solvents is preferably 5.0 to 30% by mass, more preferably 7.5 to 27.5% by mass, and still more preferably 15 to 25% by mass with respect to the total amount of the ink composition. When the total content of the organic solvents is within the above range, in addition to the rubbing fastness and storage stability, the peel resistance of the printed surface and the texture of the recording material tend to be further improved.

[0028] 1.2. Resin particles The resin particles are not particularly limited, and examples include acrylic resin particles, urethane resin particles, polyester resin particles, and polyethylene resin particles. Among these, urethane resin particles are preferable. By using such resin particles, in addition to the rubbing fastness and storage stability, the peel resistance of the printed surface and the texture of the recording material tend to be further improved. The resin particles may be used alone or in combination of two or more.

[0029] The acrylic resin particles are not particularly limited, and examples include those obtained by polymerizing (meth)acrylic monomers such as (meth)acrylic acid and (meth)acrylic acid esters, and those obtained by copolymerizing (meth)acrylic monomers and other monomers. Among these, anionic acrylic resin particles are preferable.

[0030] The urethane resin particles are not particularly limited as long as they are resin particles having a urethane bond in the molecule, and examples include polyether-type urethane resins containing an ether bond in the main chain, polyester-type urethane resins containing an ester bond in the main chain, and polycarbonate-type urethane resins containing a carbonate bond in the main chain. Among these, polyether-type urethane resins or polycarbonate-type urethane resins are preferred, and polycarbonate-type urethane resins are more preferred. Also, from the viewpoint of improving dispersion stability, etc., anionic urethane resin particles having a carboxy group, a sulfo group, a hydroxy group, etc. are preferred.

[0031] The polyester resin particles are not particularly limited as long as they are obtained by the reaction of an acid component and an alcohol component. Examples of the acid component include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, fumaric acid, maleic acid, itaconic acid, cyclohexanedicarboxylic acid, tetrahydrophthalic acid, etc. Examples of the alcohol component include the glycols exemplified as organic solvents.

[0032] Also, the resin particles are not particularly limited, and examples include non-crosslinkable resin particles and crosslinkable resin particles having a crosslinkable group. Among these, non-crosslinkable resin particles are preferred. The crosslinkable group may be one that reacts between crosslinkable groups to form a crosslinked structure, or may be one that reacts with a functional group different from the crosslinkable group to form a crosslinked structure. By using non-crosslinkable urethane resin particles, the storage stability and the texture of the resulting recording are more likely to be improved.

[0033] The content of the resin particles is preferably 2.0 to 15% by mass, more preferably 3.0 to 10% by mass, and still more preferably 5.0 to 8.0% by mass with respect to the total amount of the ink composition. When the content of the resin particles is 2.0% by mass or more, the dry rubbing fastness of the obtained recording tends to be further improved. Also, when the content of the resin particles is 10% by mass or less, the texture, dry rubbing fastness of the obtained recording, and storage stability of the ink composition tend to be further improved.

[0034] 1.3. Plasticizer As the plasticizer, those that impart plasticity or increase plasticity can be used. The object to which plasticity is imparted or increased is not particularly limited, but examples include synthetic resins and synthetic rubbers, and those that are more preferably those that impart plasticity or increase plasticity to the above resin particles. Such plasticizers are not particularly limited, and examples include aliphatic carboxylic acid esters, aromatic carboxylic acid ester compounds, phosphate ester compounds, cycloalkane (ene) carboxylic acid ester compounds, oxyacid ester compounds, glycol ester compounds, epoxy ester compounds, sulfonamide compounds, polyester compounds, polyether compounds, glyceryl alkyl ether compounds, glyceryl alkyl ester compounds, glycol alkyl ether compounds, glycol alkyl ester compounds, ethers or esters of trimethylolpropane, and ethers or esters of pentaerythritol.

[0035] Among these, aromatic carboxylic acid ester compounds such as benzoic acid derivatives and phthalic acid derivatives, cycloalkane (ene) carboxylic acid ester compounds such as cyclohexene derivatives, polyether compounds, etc. are preferred, cycloalkane (ene) carboxylic acid ester compounds are more preferred, and cyclohexenedicarboxylic acid compounds are still more preferred. By using such a plasticizer, the film-forming property of the resin particles becomes good, and in addition to the rubbing fastness and storage stability, the peel resistance of the printed surface and the texture of the recording tend to be further improved.

[0036] In addition, as the plasticizer, it is preferable to include a plasticizer with an SP value of 8.0 to 10. By using such a plasticizer, in addition to the rubbing fastness and storage stability, the peel resistance of the printed surface and the texture of the recording material tend to be further improved. Such a plasticizer has good solubility in an organic solvent with an SP value of 9.5 to 10.5, and in particular, the storage stability can be made good.

[0037] The content of the plasticizer is preferably 0.1 to 2.0% by mass, more preferably 0.2 to 1.2% by mass, and still more preferably 0.3 to 0.7% by mass with respect to the total amount of the ink composition. When the content of the plasticizer is 0.1% by mass or more, the rubbing fastness and texture tend to be further improved. Also, when the content of the plasticizer is 2.0% by mass or less, the storage stability and the peelability of the printed surface tend to be further reduced.

[0038] 1.4. Water The content of water is preferably 50 to 85% by mass, more preferably 55 to 80% by mass, and still more preferably 60 to 75% by mass with respect to the total amount of the ink composition.

[0039] 1.5. Colorant The ink composition of this embodiment may further contain a colorant. As the colorant, at least one of a pigment and a dye can be used. Among these, the ink composition of this embodiment is preferably a pigment printing ink containing a pigment. Since the problem of rubbing fastness particularly easily occurs in the case of pigment printing, the present invention is particularly useful. Also, when the colorant is a pigment, it is preferable in that it is possible to print on various fabrics such as cotton, polyester, and nylon.

[0040] The pigments are not particularly limited, and examples thereof include carbon blacks (C.I. Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black; inorganic pigments such as iron oxide and titanium oxide; organic pigments such as quinacridone pigments, quinacridone quinone pigments, dioxazine pigments, phthalocyanine pigments, anthrapyrimidine pigments, ansanthrone pigments, indanthrone pigments, flavanthrone pigments, perylene pigments, diketopyrrolopyrrole pigments, perinone pigments, quinophthalone pigments, anthraquinone pigments, thioindigo pigments, benzimidazolone pigments, isoindolinone pigments, azomethine pigments, and azo pigments.

[0041] The dyes are not particularly limited, and examples thereof include acid dyes such as C.I. Acid Yellow, C.I. Acid Red, C.I. Acid Blue, C.I. Acid Orange, C.I. Acid Violet, and C.I. Acid Black; basic dyes such as C.I. Basic Yellow, C.I. Basic Red, C.I. Basic Blue, C.I. Basic Orange, C.I. Basic Violet, and C.I. Basic Black; direct dyes such as C.I. Direct Yellow, C.I. Direct Red, C.I. Direct Blue, C.I. Direct Orange, C.I. Direct Violet, and C.I. Direct Black; reactive dyes such as C.I. Reactive Yellow, C.I. Reactive Red, C.I. Reactive Blue, C.I. Reactive Orange, C.I. Reactive Violet, and C.I. Reactive Black; and disperse dyes such as C.I. Disperse Yellow, C.I. Disperse Red, C.I. Disperse Blue, C.I. Disperse Orange, C.I. Disperse Violet, and C.I. Disperse Black. The above dyes may be used alone or in combination of two or more.

[0042] The content of the coloring material is preferably 1.0 to 10% by mass, more preferably 2.5 to 7.5% by mass, based on the total amount of the ink composition.

[0043] 1.6. Surfactant The ink composition of this embodiment may further contain a surfactant. The surfactant is not particularly limited, and examples thereof include acetylene glycol-based surfactants, fluorine-based surfactants, and silicone-based surfactants.

[0044] The acetylene glycol-based surfactant is not particularly limited, and for example, one or more selected from 2,4,7,9-tetramethyl-5-decyne-4,7-diol and alkylene oxide adducts of 2,4,7,9-tetramethyl-5-decyne-4,7-diol, and 2,4-dimethyl-5-decyne-4-ol and alkylene oxide adducts of 2,4-dimethyl-5-decyne-4-ol are preferable.

[0045] The fluorine-based surfactant is not particularly limited, and examples thereof include perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkyl phosphates, perfluoroalkyl ethylene oxide adducts, perfluoroalkyl betaines, and perfluoroalkyl amine oxide compounds.

[0046] Examples of the silicone-based surfactant include polysiloxane-based compounds and polyether-modified organosiloxanes.

[0047] The content of the surfactant is preferably 0.1 to 1.0% by mass, more preferably 0.1 to 0.5% by mass, based on the total amount of the ink composition.

[0048] 1.7. pH Adjusting Agent The ink composition of this embodiment may further contain a pH adjuster. The pH adjuster is not particularly limited, and examples thereof include inorganic acids (e.g., sulfuric acid, hydrochloric acid, nitric acid, etc.), inorganic bases (e.g., lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonia, etc.), organic bases (triethanolamine, diethanolamine, monoethanolamine, tripropanolamine), organic acids (e.g., adipic acid, citric acid, succinic acid, etc.), and the like. By including a pH adjuster, the dispersion stability tends to be further improved. The pH adjuster may be used alone or in combination of two or more.

[0049] The content of the pH adjuster is preferably 0.01 to 0.5% by mass, more preferably 0.05 to 0.3% by mass, and still more preferably 0.05 to 0.2% by mass, based on the total amount of the ink composition.

[0050] 2. Ink set The ink set of this embodiment includes the above aqueous inkjet ink composition and a treatment liquid composition containing a resin selected from the group consisting of a polyurethane resin and a polyester resin and water, and may further include another treatment liquid composition containing a flocculant and water as necessary. Hereinafter, the treatment liquid composition containing a resin selected from the group consisting of a polyurethane resin, a polyester resin, and an acrylic resin is referred to as a post-treatment liquid, and another treatment liquid composition containing a flocculant is referred to as a pre-treatment liquid.

[0051] 2.1. Treatment liquid composition (post-treatment liquid) The treatment liquid composition which is a post-treatment liquid contains a resin selected from the group consisting of a polyurethane resin, a polyester resin, and an acrylic resin and water, and may contain other additives as necessary. There is a concern that the printed surfaces may easily adhere to each other and the ink coating film may peel off by separating the adhesion, but by coating with such a post-treatment liquid, the peel resistance can be improved.

[0052] 2.1.1. Resin The polyurethane resin is not particularly limited as long as it is a resin having a urethane bond in the molecule, and examples thereof include a polyether-type urethane resin containing an ether bond in the main chain, a polyester-type urethane resin containing an ester bond in the main chain, and a polycarbonate-type urethane resin containing a carbonate bond in the main chain.

[0053] The polyester resin is not particularly limited, and examples thereof include those obtained by the reaction of an acid component and an alcohol component. As the acid component and the alcohol component, the same ones as those described above can be used.

[0054] The acrylic resin may be a resin polymerized from a monomer containing at least acrylate or acrylic acid, and may contain other monomers such as styrene.

[0055] The content of the resin is preferably 1.0 to 10% by mass, more preferably 1.5 to 10% by mass, and still more preferably 2.5 to 7.5% by mass with respect to the total amount of the post-treatment liquid.

[0056] 2.1.2. Water The content of water is preferably 90 to 99% by mass, more preferably 90 to 98.5% by mass, and still more preferably 92.5 to 97.5% by mass with respect to the total amount of the post-treatment liquid.

[0057] 2.2. Treatment liquid composition (pretreatment liquid) The treatment liquid composition, which is a pretreatment liquid, contains a flocculant and water, and may contain a fixing resin or a surfactant as necessary.

[0058] 2.2.1. Flocculant The flocculant is not particularly limited, and examples thereof include polyvalent metal salts and cationic resins.

[0059] The polyvalent metal salt is not particularly limited, and examples thereof include polyvalent metal salts of inorganic acids or polyvalent metal salts of organic acids. The polyvalent metal is not particularly limited, and examples thereof include alkaline earth metals of Group 2 of the periodic table (e.g., magnesium, calcium), transition metals of Group 3 of the periodic table (e.g., lanthanum), earth metals from Group 13 of the periodic table (e.g., aluminum), and lanthanides (e.g., neodymium). As salts of these polyvalent metals, carboxylates (formate, acetate, benzoate, etc.), sulfates, nitrates, chlorides, and thiocyanates are preferred.

[0060] Among these, calcium salts or magnesium salts of carboxylic acids (formic acid, acetic acid, benzoate, etc.), calcium salts or magnesium salts of sulfuric acid, calcium salts or magnesium salts of nitric acid, calcium chloride, magnesium chloride, and calcium salts or magnesium salts of thiocyanic acid can be mentioned. In addition, the polyvalent metal salt may be used alone or in combination of two or more.

[0061] The cationic resin is not particularly limited, and examples thereof include amine-based resins such as polyallylamine, poly(vinylpyridine) salts, polyalkylaminoethyl acrylate, polyalkylaminoethyl methacrylate, poly(vinylimidazole), poly(glucosamine), polyethyleneimine, polybiguanide, polyhexamethylene guanide, and polyguanide.

[0062] The content of the flocculant is preferably 10 to 30% by mass, more preferably 15 to 25% by mass, based on the total amount of the pretreatment liquid. When the content of the flocculant is within the above range, the rubbing fastness and texture tend to be further improved.

[0063] 2.2.2. Water The water content is preferably 65 to 90% by mass, more preferably 70 to 85% by mass, and still more preferably 75 to 80% by mass, based on the total amount of the pretreatment liquid.

[0064] 2.2.3. Fixing resin The fixing resin is not particularly limited, and examples thereof include polyurethane resins, polyester resins, and acrylic resins. As these resins, those described above can be used in the post-treatment liquid or the ink composition. The content of the fixing resin is preferably 0.5 to 5.0% by mass, more preferably 1.0 to 3.0% by mass, based on the total amount of the pretreatment liquid.

[0065] 2.2.4. Surfactant As the surfactant, those exemplified in the above ink composition can be used. The content of the surfactant is preferably 0.1 to 1.0% by mass, more preferably 0.3 to 0.7% by mass, based on the total amount of the pretreatment liquid.

[0066] 3. Recording Method The recording method of the present embodiment has an ink adhesion step of discharging the above aqueous inkjet ink composition by an inkjet method and adhering it to a recording medium, and, if necessary, a pretreatment liquid adhesion step of adhering the treatment liquid composition, which is the pretreatment liquid, to the recording medium, a post-treatment liquid adhesion step of adhering the treatment liquid composition, which is the post-treatment liquid, to the recording medium, and a drying step of drying the aqueous inkjet ink composition adhered to the recording medium.

[0067] 3.1. Pretreatment Liquid Adhesion Step The pretreatment liquid adhesion step is a step of adhering the pretreatment liquid to the recording medium. At this time, from the viewpoint of aggregating the components of the ink composition, at least a part of the adhesion region of the pretreatment liquid and the adhesion region of the ink composition overlap. By providing such a pretreatment liquid adhesion step, the components of the ink composition tend to aggregate on the surface of the recording medium, and the image quality and rubbing fastness of the obtained recording tend to be further improved.

[0068] As a method of adhering the pretreatment liquid, in addition to the method of adhering using an inkjet method, it may be applied using a bar coater, a roll coater, a spray, or the like.

[0069] The pretreatment liquid adhesion step may be performed before or after the ink adhesion step described below. It is preferably performed before the ink adhesion step described below. Further, when the pretreatment liquid adhesion step is performed before the ink adhesion step, the ink adhesion step may be performed before the pretreatment liquid dries or after the pretreatment liquid dries.

[0070] 3.2. Ink Adhesion Step The ink adhesion step is a step of discharging the above ink composition by an inkjet method and adhering it to a recording medium. Here, the inkjet head used in the inkjet method is a head that discharges the ink composition toward the recording medium for recording. The head has a cavity that discharges the stored ink composition from a nozzle, a discharge driving unit that applies a driving force for discharge to the ink composition, and a nozzle that discharges the ink composition to the outside of the head. The discharge driving unit can be formed using an electromechanical conversion element such as a piezoelectric element that changes the volume of the cavity by mechanical deformation, or an electrothermal conversion element that generates bubbles in the ink by generating heat and discharges it.

[0071] 3.3. Drying Step The drying step is a step of drying the ink composition adhered to the recording medium. The drying temperature is not particularly limited. For example, it is preferably 60 to 150°C, more preferably 100 to 150°C, and even more preferably 130 to 150°C. Also, the drying time is not particularly limited, but for example, it can be 30 seconds to 5 minutes. By containing a plasticizer, the film-forming property becomes good, and such low-temperature treatment is possible. At such a temperature, damage to the fabric can be suppressed to a low level, and it can be preferably printed on a fabric containing any one selected from the group consisting of nylon fibers and polyester fibers.

[0072] Note that the above drying step may be performed not only after the ink adhesion step but also after the pretreatment liquid adhesion step and the post-treatment liquid adhesion step, respectively.

[0073] 3.4. Post-Treatment Adhesion Step The post-treatment adhesion step is a step of adhering a treatment liquid composition, which is a post-treatment liquid, to a recording medium. At this time, from the viewpoint of covering the adhesion area of the ink composition with the post-treatment liquid to improve the peel resistance of the printing surface, at least a part of the adhesion area of the post-treatment liquid and the adhesion area of the ink composition overlap. By providing such a post-treatment liquid adhesion step, the image quality, rubbing fastness, and peel resistance of the obtained recording tend to be further improved. Note that the post-treatment adhesion step is preferably carried out after the ink adhesion step from the above viewpoint.

[0074] As a method of adhering the post-treatment liquid, in addition to the method of adhering using an inkjet method, it may be applied using a bar coater, a roll coater, a spray, or the like.

[0075] 3.5. Recording Medium The recording medium is not particularly limited. For example, fabrics composed of natural fibers, synthetic fibers, or semi-synthetic fibers such as silk, cotton, wool, nylon, polyester, and rayon can be mentioned. Among these, fabrics containing any one selected from the group consisting of nylon fibers and polyester fibers are preferred. By using such a recording medium, a recording having excellent rubbing fastness, texture, etc. can be obtained.

Examples

[0076] Hereinafter, the present invention will be described more specifically using examples and comparative examples. The present invention is not limited by the following examples at all.

[0077] 1. Preparation of Ink Composition Each component was put into a mixture tank so as to have the composition described in Tables 3 to 4, mixed and stirred, and further filtered through a 5 μm membrane filter to obtain the ink composition of each example. Note that the numerical values of each component shown in each example in the table represent mass% unless otherwise specified.

[0078] The abbreviations and product components used in Tables 3 to 4 are as follows. <Pigment> Carbon black (manufactured by Orient Chemical Industries, product name BONJET BLACK CW-1) <Resin particles> Non-crosslinkable urethane resin (manufactured by Mitsui Chemicals, Takelac W-6061) <Plasticizer> Benzoic acid-based plasticizer (manufactured by Adeka, Adekaizer PN-6120, SP value: 9.8) Phthalic acid-based plasticizer (dioctyl phthalate, SP value: 8.9) Cyclohexenedicarboxylic acid-based plasticizer (manufactured by Shin Nippon Rika Co., Ltd., Sansosaizer DOTH) Polyether-based plasticizer (manufactured by Adeka, Adekaizer RS-966, SP value: 8.6) <Organic solvent> Glycerin (SP value: 16.5) Ethylene glycol diethyl ether (SP value: 8.6) Diethylene glycol monobutyl ether (SP value: 9.5) 2-Methyl-1,3-pentanediol (SP value: 10.3) 2-Methyl-1,4-pentanediol (SP value: 9.5 - 10.5) Ethylene glycol monomethyl ether (SP value: 11.4) 1,4-Butanediol (SP value: 12.1) Triethylene glycol (SP value: 10.7) <pH adjuster> KOH (potassium hydroxide) <Surfactant> Orfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd., acetylene glycol-based surfactant)

[0079] 1.2. Pretreatment liquid To obtain the pretreatment liquid for each example, each component was put into a mixture tank, mixed and stirred, and further filtered through a 5 μm membrane filter so as to have the composition shown in Table 1. The numerical values of each component shown in each example in the table represent mass % unless otherwise specified.

[0080]

Table 1

[0081] 1.3. Post-treatment liquid Each component was put into a tank for the mixture so as to have the composition shown in Table 2, mixed and stirred, and further filtered through a 5-μm membrane filter to obtain the post-treatment liquid for each example. Note that the numerical values of each component shown in the table represent mass % unless otherwise specified.

[0082]

Table 2

[0083] 2. Evaluation 2.1. Storage stability After putting each of the ink compositions prepared above into a sample bottle and sealing it, the glass bottle was placed in a constant temperature bath at 40°C and stored for 2 weeks. Using a vibrating viscometer, the viscosities before and after storage were measured in accordance with JIS Z8809, the change rate of viscosity after standing for 2 weeks was calculated, and the storage stability was evaluated according to the following evaluation criteria. When the evaluation of storage stability is A or B, it can be said that good results are obtained. (Evaluation criteria) A: Viscosity change rate is 3% or less B: Viscosity change rate is more than 3% and 5% or less C: Viscosity change rate is more than 5%

[0084] 2.2. Rubbing fastness The above ink composition was filled into the cartridge of an inkjet printer PM-870C (manufactured by Seiko Epson Corporation). After filling, a nozzle check pattern was printed to confirm that there was no filling defect or nozzle clogging. Then, the discharged ink weight per dot was set to approximately 40 ng with respect to a fabric (polyester (PES) or 100% nylon, plain weave) coated with the pretreatment liquid, and a solid pattern was printed at an ink adhesion density of 360×360 dpi in both vertical and horizontal directions.

[0085] The pretreatment liquid was applied to the fabric using a padding machine so that the pickup rate was 80%, and then adhered by heating at 100°C for 3 minutes.

[0086] Next, after printing the solid pattern, it was left for 1 minute, and then the post-treatment liquid was again adhered to the solid pattern by inkjet under the same conditions, and heated at 140°C for 3 minutes to obtain a recorded matter. In Example 5, the post-treatment liquid was not adhered, and after printing the solid pattern, it was heated at 140°C for 3 minutes to obtain a recorded matter.

[0087] The recorded matter obtained as described above was evaluated for rubbing fastness according to ISO-105X12. The evaluation criteria are shown below. When the evaluation of rubbing fastness is A to C, it can be said that good results are obtained. (Evaluation Criteria) A: Exceeds grade 3 for wet rubbing B: Grade 3 for wet rubbing C: Grade 2 - 3 for wet rubbing D: Below grade 2 for wet rubbing

[0088] 2.3. Texture The printed part of the recorded matter created in the above dry rubbing fastness was directly touched with the palm of the hand, and the feeling at that time was judged according to the following criteria. The judgment was made by 3 people, and the most supported opinion was taken as the judgment result. When the judgments were divided one by one, the intermediate opinion among them was judged. (Evaluation Criteria) A: The hardness and feel of the printed part are almost the same as the original fabric, and it is good. B: The hardness or feel of the printing part changes slightly compared to the original fabric, but it is not a problem for practical use. C: The hardness or feel of the printing part deteriorates compared to the original fabric, but it is within the allowable range. D: The hardness or feel of the printing part deteriorates compared to the original fabric, and it is in an unacceptable range.

[0089] 2.4. Peeling resistance The recording material created in the above dry rubbing fastness test was folded in half so that the solid pattern faced each other, and a load of 10 gf / cm 2 was applied and left for one week. Then, the folded recording material was opened, and it was visually confirmed whether peeling occurred on the printing surface. Based on the confirmation result, the peeling resistance was evaluated. The evaluation criteria are shown below. A: No adhesion or peeling is observed on the printing surface. B: Adhesion is observed on the printing surface, but no peeling is observed. C: Slight peeling is observed on the printing surface. D: Peeling is observed on the printing surface.

[0090] 2.5. Environmental adaptability The ink composition composed of components with relatively high safety to the human body etc. was evaluated as A, and the others were evaluated as B.

[0091]

Table 3

[0092]

Table 4

[0093] 4. Evaluation results Table 3 - 4 shows the evaluation results of the examples and comparative examples. From Table 3 - 4, it can be seen that by using a plasticizer and a predetermined organic solvent, the storage stability and rubbing fastness are further improved, and the texture, peeling resistance, and environmental adaptability are also improved.

Claims

1. An aqueous inkjet ink composition containing an organic solvent having an SP value of 9.5 to 10.5, resin particles, a plasticizer, and water, wherein the organic solvent is contained in an amount of 1.0 to 10.0% by mass based on the total amount of the ink composition, the plasticizer includes a cyclohexenedicarboxylic acid-based compound, the resin particles are those imparted with plasticity or having increased plasticity by the plasticizer, and the resin particles are urethane resin particles, wherein the organic solvent having an SP value of 9.5 to 10.5 includes methylpentanediol. Aqueous inkjet ink composition.

2. The aqueous inkjet ink composition according to Claim 1, wherein the plasticizer includes a plasticizer having an SP value of 8 to 10.

3. The aqueous inkjet ink composition according to Claim 1 or 2, wherein the content of the plasticizer is 0.1 to 2.0% by mass based on the total amount of the ink composition.

4. An ink set having: the aqueous inkjet ink composition according to any one of Claims 1 to 3; and a treatment liquid composition containing a resin selected from the group consisting of a polyurethane resin, a polyester resin, and an acrylic resin, and water.

5. A recording method having an ink adhesion step of discharging the aqueous inkjet ink composition according to any one of Claims 1 to 3 by an inkjet method and adhering it to a recording medium.

6. The recording method according to Claim 5, having a treatment liquid adhesion step of adhering a treatment liquid composition containing a resin selected from a polyurethane resin and a polyester resin and water to the recording medium.

7. The recording method according to Claim 5 or 6, having a drying step of drying the aqueous inkjet ink composition adhered to the recording medium.

8. The recording method according to Claim 7, wherein in the drying step, the recording medium is heated to 130 to 150°C.

9. The recording method according to any one of Claims 5 to 8, wherein the recording medium is a fabric.

10. The recording method according to Claim 9, wherein the fabric contains any one selected from the group consisting of nylon fibers and polyester fibers. ​ ​ ​ 、 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Images