JP5140995B2 - Inkjet printing method - Google Patents

Description

  The present invention relates to an ink-jet printing method in which a high-quality printed image is obtained on a fabric and the bleeding property is excellent.

  In recent years, technology development for extending ink jet recording to the textile printing field has been proposed. Various properties are required for the ink used for such ink jet textile printing. For example, there is no bleeding in printing on the recording material fabric, the adjacent colors are not mixed in multicolor printing, the drying property is good, and the fastness after fixing is excellent. It is.

  Ink-jet textile printing prints ink on the fabric, so bleeding (reproducibility of fine lines), color bleeding (mixing of colors between different colors), back-through, etc. occur, so pre-treatment on the fabric is essential to prevent this. there were. In this pretreatment step, for example, a pretreatment agent such as glue, water-soluble salts or inorganic fine particles is generally applied to the fabric by a pad method, a coating method, a spray method or the like. However, such a pretreatment process is complicated, and after ink jet printing is completed, a process (cleaning process) for removing such a pretreatment agent is also required, which is a big problem as an on-demand process.

Ink-jet printing inks using dyes require a post-treatment process (coloring process) in which a dye dissolved or dispersed in an aqueous medium is printed on a fabric and fixed with heat and steam. This post-treatment process is also labor-saving. There has been a desire for an ink jet textile printing method.

  Unlike the dyes, the textile printing method using pigment ink does not require a post-treatment process (coloring process), and has been studied as an on-demand textile printing. For example, it has been proposed to improve printing bleeding and scratch resistance after heat fixing by blending a polymer in the ink (for example, see Patent Document 1). However, it is difficult to prevent bleeding and color bleeding even with pigment ink, and satisfactory image quality cannot be obtained without pre-treatment of the fabric.

An ink that is cured by ultraviolet rays is known as an ink-jet ink that hardly causes bleeding or color bleeding on a recording medium (for example, see Patent Document 2). Tri- or higher functional acrylates are disclosed as ultraviolet curable materials. Bleeding and color bleed are alleviated to some extent due to a sudden increase in viscosity due to UV curing, but because it is a non-aqueous solvent, the ink reaches the back side of the fabric (through-through), and there is a disadvantage that the concentration is inevitably lowered. there were. Even when the ink does not show through, since most of the ink is a curable component, the surface of the fabric is swelled, and only a printed matter with a feeling of tingling can be obtained.
JP-A-8-283636 Japanese Patent Publication No. 5-54667

  An object of the present invention is to provide an ink-jet printing method that is suitable for a fabric that is not pretreated, prevents bleeding and color bleeding, obtains a high density, and does not impair the texture of the fabric.

  The above object of the present invention can be achieved by the following configuration.

［式中、Ｒ_２はＭｅ又はＨ、ｎは１又は２を表し、Ｘは−（ＣＨ_２）_ｍ−ＣＯＯ−、−ＣＨ_２−ＣＯＯ−又は−Ｏ−、Ｙは芳香族環又は単結合、ｍは０〜６までの整数を表す］ 1. A step of ejecting ink droplets of a pigment ink containing at least water, a pigment, and a polymer compound having a plurality of side chains in a hydrophilic main chain from a recording head and attaching the ink droplets onto the fabric; Irradiating the ink with active energy rays and curing the ink, wherein the polymer compound is a polymer compound having a partial structure of a compound represented by the following general formula (5), An ink-jet printing method comprising cross-linking between the side chains by irradiation with active energy rays.

[Wherein R ₂ represents Me or H, n represents 1 or 2, X represents — (CH ₂ ) _m —COO—, —CH ₂ —COO— or —O—, and Y represents an aromatic ring or a single bond. , M represents an integer from 0 to 6]

  2. 2. The ink jet printing method according to 1 above, wherein the fabric is not pretreated.

  3. 3. The ink-jet printing method according to 1 or 2, wherein the hydrophilic main chain of the polymer compound is a saponified product of polyvinyl acetate, and the degree of polymerization is 200 or more and 2000 or less.

  4). 4. The ink jet printing method according to any one of 1 to 3, wherein the polymer compound has a side chain modification rate of 0.3 mol% or more and 4 mol% or less with respect to the hydrophilic main chain.

  5). 5. The inkjet printing method according to any one of 1 to 4, wherein a contact angle between the pigment ink and the fabric is 40 to 100 degrees.

  6). 6. The inkjet printing method according to any one of 1 to 5, wherein the pigment ink contains a photopolymerization initiator in an amount of 0.1% by mass or more and less than 1.0% by mass with respect to the total mass of the ink.

7). The active energy ray, ink-jet printing process according to any one of the 1 to 6, characterized in that an ultraviolet.

  8). 8. The inkjet printing method according to any one of 1 to 7, wherein a heat fixing process is performed after the pigment ink is attached to the fabric.

  According to the present invention, it is possible to provide an ink-jet printing method that has a variety of fabrics, prevents bleeding and color bleeding, obtains a high density, and does not impair the texture of the fabric.

  In the present invention, a pigment ink (hereinafter also simply referred to as ink) contains a polymer compound having a plurality of side chains in a hydrophilic main chain and capable of crosslinking between side chains by irradiation with active energy rays. The ink is printed on a cloth, and the ink itself is thickened (gelled) by a curing reaction, thereby suppressing bleeding (reproducibility of fine lines) and color bleeding (color mixing between different colors). Since this ink has the above-described characteristics, it is possible to print on a fabric without pretreatment. Further, since the ink of the present invention uses a pigment as a coloring material, printing can be performed on various fabrics without a post-process (coloring process) like a reactive dye, an acid dye, and a disperse dye.

  The present invention will be described in detail below.

(Active energy ray crosslinkable polymer compound)
The polymer compound having a plurality of side chains in the hydrophilic main chain according to the present invention and capable of crosslinking between the side chains by irradiating with active energy rays is a saponified product of polyvinyl acetate, polyvinyl acetal, polyethylene Oxide, polyalkylene oxide, polyvinylpyrrolidone, polyacrylamide, polyacrylic acid, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, or a derivative of the hydrophilic resin, and at least one hydrophilic selected from the group consisting of these copolymers In the resin, a modified group such as a photodimerization type, a photodecomposition type, a photopolymerization type, a photomodification type, or a photodepolymerization type is introduced into the side chain. Photopolymerizable crosslinkable groups are desirable from the viewpoints of sensitivity and performance of the generated image.

  In the hydrophilic main chain, a saponified product of polyvinyl acetate is preferable from the viewpoint of ease of introduction of side chains and handling, and the degree of polymerization measured by JIS K 6726 is preferably 200 or more and 4000 or less, and 200 or more and 2000 or less. More preferable from the viewpoint of handling. The modification rate of the side chain with respect to the main chain is preferably 0.3 mol% or more and 4 mol% or less, and more preferably 0.8 mol% or more and 4 mol% or less from the viewpoint of reactivity. If it is less than 0.3 mol%, the crosslinkability is insufficient and the effect of the present invention is reduced. If it is more than 4 mol%, the crosslink density is increased and the film is hard and brittle, and the strength of the film is lowered.

  As the photodimerization-type modifying group, those in which a diazo group, a cinnamoyl group, a stilbazonium group, a stilquinolium group or the like is introduced are preferable. For example, a photosensitive resin described in JP-A-60-129742 (Composition).

  The photosensitive resin described in JP-A-60-129742 is a compound represented by the following general formula (1) in which a stilbazonium group is introduced into a polyvinyl alcohol structure.

In the formula, R ₁ represents an alkyl group having 1 to 4 carbon atoms, and A ⁻ represents a counter anion.

  The photosensitive resin described in JP-A-56-67309 includes a 2-azido-5-nitrophenylcarbonyloxyethylene structure represented by the following general formula (2) in the polyvinyl alcohol structure, or the following general formula. It is a resin composition represented by (3) and having a 4-azido-3-nitrophenylcarbonyloxyethylene structure.

  Further, a modifying group represented by the following general formula (4) is also preferably used.

  In the formula, R represents an alkylene group or an aromatic ring. A benzene ring is preferred.

  As the photopolymerization type modifying group, for example, resins represented by the following general formula (5) shown in JP-A Nos. 2000-181062 and 2004-189841 are preferable from the viewpoint of reactivity.

In the formula, R ₂ represents Me or H, n represents 1 or 2, X represents — (CH ₂ ) _m —COO—, —CH ₂ —COO— or —O—, Y represents an aromatic ring or a single bond, m represents an integer of 0 to 6.

  Moreover, it is also preferable to use the photopolymerization type | mold modified group represented by following General formula (6) described in Unexamined-Japanese-Patent No. 2004-161942 for a conventionally well-known water-soluble resin.

In the formula, R ₃ represents Me or H, and R ₄ represents a linear or branched alkylene group having 2 to 10 carbon atoms.

  Such an active energy ray-crosslinking resin is preferably contained in an amount of 0.8% by mass to 5.0% by mass with respect to the total mass of the ink. The presence of 0.8% by mass or more improves cross-linking efficiency, and beading and color bleeding are more preferable due to a rapid increase in ink viscosity after cross-linking. In the case of 5.0% by mass or less, it is difficult to adversely affect the physical properties of the ink and the state in the ink head, which is preferable from the viewpoint of the light emission property and the ink storage property.

  In the active energy ray cross-linking resin of the present invention, the main chain having a certain degree of polymerization is cross-linked through a cross-linking bond between side chains, and thus polymerizes through a general chain reaction. The effect of increasing the molecular weight per photon is significantly larger than that of an active energy ray curable resin. On the other hand, in the conventionally known active energy ray curable resins, the number of crosslinking points cannot be controlled, so the physical properties of the cured film cannot be controlled, and the film tends to be hard and brittle.

  In the resin used in the present invention, the number of crosslinking points can be completely controlled by the length of the hydrophilic main chain and the amount of side chains introduced, and the physical properties of the ink film can be controlled according to the purpose.

  Furthermore, almost all of the conventionally known active energy ray-curable inks other than the colorant are curable, so that the dots after curing are raised and inferior in image quality typified by gloss, are used in the present invention. The resin requires only a small amount, and since there are many dry components, the image quality after drying is improved and the fixing property is also good.

(Photopolymerization initiator, sensitizer)
In the present invention, it is also preferable to add a photopolymerization initiator or a sensitizer. These compounds may be dissolved or dispersed in a solvent, or may be chemically bonded to the photosensitive resin. The addition amount of the photopolymerization initiator is preferably 0.1% by mass or more and less than 1.0% by mass with respect to the total mass of the ink. When the content is 0.1% by mass or more, the crosslinking reaction by active energy ray irradiation proceeds sufficiently, which is preferable in terms of bleeding and color mixing. Moreover, when it contains less than 1.0 mass%, the photoinitiator which remained in the fabric of the printing part is preferable with little fading with time.

  There is no restriction | limiting in particular about the photoinitiator and photosensitizer which are applied, A conventionally well-known thing can be used.

  Although there is no restriction | limiting in particular about the photoinitiator and photosensitizer which are applied, A water-soluble thing is preferable from a viewpoint of mixability and reaction efficiency. In particular, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone (HMPK), thioxanthone ammonium salt (QTX), and benzophenone ammonium salt (ABQ) are preferable from the viewpoint of miscibility with an aqueous solvent.

  Furthermore, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone (n = 1, HMPK) represented by the following general formula (7) from the viewpoint of compatibility with the resin, The ethylene oxide adduct (n = 2 to 5) is more preferable.

  In the formula, n represents an integer of 1 to 5.

  Other examples include benzophenones such as benzophenone, hydroxybenzophenone, bis-N, N-dimethylaminobenzophenone, bis-N, N-diethylaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone. Thioxanthones such as thioxatone, 2,4-diethylthioxanthone, isopropylthioxanthone, chlorothioxanthone, and isopropoxychlorothioxanthone. Anthraquinones such as ethyl anthraquinone, benzanthraquinone, aminoanthraquinone and chloroanthraquinone. Acetophenones. Benzoin ethers such as benzoin methyl ether. 2,4,6-trihalomethyltriazines, 1-hydroxycyclohexyl phenyl ketone, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di ( m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-phenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-phenylimidazole dimer, 2- (P-methoxyphenyl) -4,5-diphenylimidazole dimer, 2, -di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4,5 -2,4,5-triarylimidazole dimer of diphenylimidazole dimer, benzyldimethyl ketal, 2-benzyl-2-dimethyl Amino-1- (4-morpholinophenyl) butan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-hydroxy-2-methyl-1-phenyl -Propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, phenanthrenequinone, 9,10-phenanthrenequinone, Benzoins such as methylbenzoin and ethylbenzoin, 9-phenylacridine, acridine derivatives such as 1,7-bis (9,9'-acridinyl) heptane, bisacylphosphine oxide, and mixtures thereof are preferably used. May be used alone or in combination.

  In addition to these photopolymerization initiators, accelerators and the like can also be added. Examples of these include ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, ethanolamine, diethanolamine, triethanolamine and the like.

  Even if these photoinitiators are grafted to the side chain with respect to the hydrophilic main chain.

(Active energy rays, irradiation method)
The active energy ray as used in the present invention includes, for example, electron beam, ultraviolet ray, α ray, β ray, γ ray, X ray and the like. However, it is dangerous to human body, easy to handle, and industrially used. Electron beams and ultraviolet rays are widely used.

  When using an electron beam, the amount of the electron beam to be irradiated is preferably in the range of 0.1 to 30 Mrad. If it is less than 0.1 Mrad, a sufficient irradiation effect cannot be obtained, and if it exceeds 30 Mrad, the support or the like may be deteriorated.

  When using ultraviolet rays, the light source is a low pressure, medium pressure, high pressure mercury lamp, metal halide lamp, xenon lamp having a light emission wavelength in the ultraviolet region, cold cathode tube, hot cathode tube, for example, having an operating pressure of 0.1 kPa to 1 MPa. A conventionally well-known thing, such as LED, is used.

(Light irradiation conditions after ink landing)
As the irradiation condition of actinic rays, actinic rays are preferably irradiated between 0.001 and 1.0 seconds after ink landing, and more preferably 0.001 to 0.5 seconds. In order to form a high-definition image, it is particularly important that the irradiation timing is as early as possible.

(Installation of lamp)
As a method for irradiating actinic rays, the basic method is disclosed in JP-A-60-132767. According to this, the light source is provided on both sides of the head unit, and the head and the light source are scanned by the shuttle method. Irradiation is performed after a certain period of time after ink landing. Further, the curing is completed by another light source that is not driven. In US Pat. No. 6,145,979, as an irradiation method, a method using an optical fiber or a method of applying a collimated light source to a mirror surface provided on the side of the head unit and irradiating the recording unit with UV light is disclosed. Yes. Any of these irradiation methods can be used in the image forming method of the present invention.

  In another preferred embodiment, irradiation with actinic rays is divided into two stages, and actinic rays are first irradiated by the above-described method between 0.001 and 2.0 seconds after ink landing, and further irradiated with actinic rays. It is. By dividing the irradiation of actinic rays into two stages, it is possible to further suppress the shrinkage of the recording material that occurs during ink curing.

(Heat fixing)
In the textile printing method of the present invention, a heat fixing step can be used after the printing step and the active energy ray irradiation step for the purpose of improving the fixability of the fabric and the pigment. Various methods can be used as the heating method. For example, (1) a method of heating a fabric by incorporating a heating heater inside the recording material feed roller of the recording apparatus, and (2) fixing by incorporating a heating heater between the recording material feed roller of the recording device and the fabric. A method of installing a platen, (3) a method of installing a heat source lamp adjacent to the recording head, and irradiating the heat source lamp from the recording surface side after recording, and (4) a method of heating the fabric by a heat generating heater after recording. These methods can also be combined.

(Pigment)
As the pigment that can be used in the present invention, conventionally known organic and inorganic pigments can be used, but they are anionic pigments. For example, azo pigments such as azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, perylene and perylene pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc. Examples include cyclic pigments, dye lakes such as acid dye lakes, organic pigments such as nitro pigments, nitroso pigments, aniline black, and daylight fluorescent pigments, and inorganic pigments such as carbon black.

  Specific organic pigments are exemplified below.

  Examples of pigments for magenta or red include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of the orange or yellow pigment include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 128, C.I. I. And CI Pigment Yellow 138.

  Examples of pigments for green or cyan include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Green 7.

  As a method for dispersing the pigment, for example, various dispersing machines such as a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, and a paint shaker can be used. It is also preferable to use a centrifugal separator or a filter for the purpose of removing the coarse particles of the pigment dispersion.

  In the ink according to the present invention, a self-dispersed pigment in which polar groups such as sulfonic acid and carboxylic acid are pendant on the pigment surface, or a pigment dispersed using a polymer dispersant is preferable.

  The polymer dispersant according to the present invention is not particularly limited, and a water-soluble resin or a water-insoluble resin is used. Examples of these polymers include styrene, styrene derivatives, vinyl naphthalene derivatives, acrylic acid, acrylic acid derivatives, methacrylic acid, methacrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid, fumaric acid. Examples thereof include a polymer composed of a single monomer selected from acid derivatives, a copolymer composed of two or more monomers, and salts thereof. Water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, cellulose derivatives, gelatin, and polyethylene glycol can also be used.

  The content of these water-soluble resins with respect to the total amount of ink is preferably 0.1 to 10% by mass, and more preferably 0.3 to 5% by mass. These water-soluble resins can be used in combination of two or more.

  The average particle size of the pigment dispersion used in the inkjet ink of the present invention is preferably 500 nm or less, more preferably 200 nm or less, preferably 10 nm or more and 200 nm or less, and more preferably 10 nm or more and 150 nm or less. If the average particle size of the pigment dispersion exceeds 500 nm, the dispersion becomes unstable. In addition, even when the average particle size of the pigment dispersion is less than 10 nm, the stability of the pigment dispersion tends to deteriorate, and the storage stability of the ink tends to deteriorate.

  The particle size of the pigment dispersion can be determined by a commercially available particle size measuring device using a light scattering method, an electrophoresis method, a laser Doppler method or the like. It is also possible to obtain a particle image with a transmission electron microscope on at least 100 particles and perform statistical processing on the image using image analysis software such as Image-Pro (manufactured by Media Cybernetics). Is possible.

(Water-soluble solvent)
As the solvent according to the present invention, an aqueous liquid medium is preferably used, and as the aqueous liquid medium, a mixed solvent such as water and a water-soluble organic solvent is further preferably used. Examples of water-soluble organic solvents that are preferably used include alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol), polyhydric alcohols (eg, ethylene glycol, diethylene glycol, Triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol), polyhydric alcohol ethers (eg, ethylene glycol monomethyl ether, ethylene Glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol Nomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, ethylene glycol Monophenyl ether, propylene glycol monophenyl ether), amines (for example, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetra) , Tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine), amides (eg, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, etc.), heterocycles (eg, 2 -Pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone), sulfoxides (for example, dimethyl sulfoxide) and the like.

(Surfactant)
Surfactants preferably used in the ink of the present invention include alkyl sulfates, alkyl ester sulfates, dialkyl sulfosuccinates, alkyl naphthalene sulfonates, alkyl phosphates, polyoxyalkylene alkyl ether phosphates, fatty acids. Anionic surfactants such as salts, nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyalkylene alkyl phenyl ethers, acetylene glycols, polyoxyethylene-polyoxypropylene block copolymers, glycerin esters, sorbitan Activators such as esters, polyoxyethylene fatty acid amides and amine oxides, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. These surfactants can also be used as pigment dispersants, and in particular, anionic and nonionic surfactants can be preferably used.

(Various additives)
In the present invention, other conventionally known additives can be contained. For example, optical brighteners, antifoaming agents, lubricants, preservatives, thickeners, antistatic agents, matting agents, water-soluble polyvalent metal salts, acid bases, pH adjusters such as buffer solutions, antioxidants, surface tension They are regulators, non-resistance regulators, rust inhibitors, inorganic pigments and the like.

(Fabric)
The material constituting the fabric used in the inkjet printing method of the present invention may be any material that contains fibers that can be dyed with pigments contained in the ink, such as cotton, silk, hemp, wool, etc. Natural fibers; synthetic fibers such as polyester, nylon, and acrylic; those containing regenerated and semi-synthetic fibers such as rayon and acetate. The above fibers may be used singly or in combination of two or more kinds of fibers, mixed fibers, interwoven fabrics, etc. The fabric can be used in any form such as a woven fabric, a knitted fabric or a non-woven fabric.

  In the inkjet textile printing method of the present invention, the contact angle of the pigment ink to the fabric is preferably 40 to 100 degrees. When the contact angle is 40 degrees or more, bleeding and color bleeding are more preferable. Further, when the contact angle is 100 degrees or less, the penetration into the fabric is quick and the drying property is good.

  Here, the contact angle between the pigment ink and the fabric is a value of the contact angle 0.2 seconds after a 2 μl droplet of the pigment ink is dropped on the fabric in an environment of 23 ° C. and 50% RH. Measurement was performed using an automatic contact angle meter (CA-VP model manufactured by Kyowa Interface Science Co., Ltd.).

  The contact angle is determined by ink viscosity, surface tension, liquid composition, and the like. As a specific means for adjusting the contact angle within this range, the viscosity is preferably 2 mPa · S or more and 20 mPa · S or less, and the surface tension is preferably 20 mN / m or more and 50 mN / m or less.

  Examples of adjusting these include the types and mixing ratios of water and water-soluble organic solvents, and the types and contents of surfactants. Water is preferably 30 to 80% of the total amount of ink, and the water-soluble organic solvent is preferably 20 to 60% of the total amount of ink. The surfactant is preferably 0.05% or more and 2.0% or less with respect to the total amount of ink.

  Examples of the present invention will be described below, but the present invention is not limited to these examples. In the examples, “%” represents mass% unless otherwise specified.

Example <Synthesis of Polymer Compound 1>
56 g of glycidyl methacrylate, 48 g of p-hydroxybenzaldehyde, 2 g of pyridine, and 1 g of N-nitroso-phenylhydroxyamine ammonium salt were put in a reaction vessel and stirred in a hot water bath at 80 ° C. for 8 hours.

  Next, 45 g of saponified polyvinyl acetate having a polymerization degree of 300 and a saponification rate of 88% was dispersed in 225 g of ion-exchanged water, and then 4.5 g of phosphoric acid and p- (3-methacryloxy-) obtained by the above reaction were added to this solution. 2-Hydroxypropyloxy) benzaldehyde was added to PVA so that the modification rate was 3 mol%, and the mixture was stirred at 90 ° C. for 6 hours. After cooling the obtained solution to room temperature, 30 g of basic ion exchange resin was added and stirred for 1 hour. Thereafter, the ion exchange resin was filtered, and as a photopolymerization initiator, Irgacure 2959 (manufactured by Ciba Specialty Chemicals) was mixed at a rate of 0.1 g with respect to 100 g of 15% aqueous solution, and then diluted with ion exchange water. A 10% aqueous solution of polymer compound 1 was obtained.

<Synthesis of polymer compound 2>
Polymer compound 2 was synthesized in the same manner as polymer compound 1, except that the amount of p- (3-methacryloxy-2-hydroxypropyloxy) benzaldehyde charged was changed to a modification rate of 0.5%.

<Synthesis of Polymer Compound 3>
Polyvinyl acetate saponified product was changed to polyvinyl acetate saponified product having a polymerization degree of 1000 and a saponification rate of 88%, and the amount of modification of p- (3-methacryloxy-2-hydroxypropyloxy) benzaldehyde was changed to 4.5%. A polymer compound 3 was synthesized in the same manner as the polymer compound 1 except that.

(Preparation of pigment dispersion)
(Preparation of magenta pigment dispersion)
The following additives were mixed and dispersed using a sand grinder filled with 50% by volume of 0.5 mm zirconia beads to prepare a magenta pigment dispersion having a magenta pigment content of 10%. The average particle size of the magenta pigment particles contained in this magenta pigment dispersion was 83 nm. The particle size was measured using a Zetasizer 1000HS manufactured by Malvern.

C. I. Pigment Red 122 10 parts Jonkrill 61 (acrylic styrene resin dispersant, manufactured by Johnson) 3 parts Glycerin 15 parts Ion-exchanged water 72 parts (Preparation of black pigment dispersion)
A carbon black self-dispersion cabo-jet 300 manufactured by Cabot was diluted with ion-exchanged water to prepare a black pigment dispersion having a carbon black content of 10%. The average particle size of the carbon black particles contained in the obtained black pigment dispersion was 153 nm. The particle size was measured using a Zetasizer 1000HS manufactured by Malvern.

(Preparation of ink set 1)
Ink and ink set 1 were prepared as follows.

Magenta pigment dispersion 30 parts 10% aqueous solution of polymer compound 1 30 parts Glycerol 7 parts Diethylene glycol 15 parts Diethylene glycol monobutyl ether 2 parts Orphine e1010 (manufactured by Nissin Chemical Co., Ltd.) 0.2 parts 100 parts was obtained to obtain a magenta pigment ink.

  A black pigment ink was obtained in the same manner using a black pigment dispersion instead of the magenta pigment dispersion.

  The obtained magenta pigment ink and black pigment ink were combined to make ink set 1.

Ink sets 2 to 5 were produced in the same manner as ink set 1, except that the compounds shown in Table 1 were used instead of 10% of polymer compound 1.
Production of Ink Set 6 Magenta ink 6 and black ink 6 which are solvent-based actinic ray curable inks were prepared as described below, and ink set 6 was produced.

(Preparation of magenta ink 6)
C. I. Pigment Red 122 10 parts Azisper PB821 (manufactured by Ajinomoto Fine Techno) 3 parts Aronix M5700 (manufactured by Toagosei Co., Ltd.) 7 parts Ethylene oxide added 1,6 hexanediol acrylate 72 parts 3-methoxybutyl acrylate 8 parts Irgacure 369 (manufactured by Ciba Specialty Chemicals) 5 parts After mixing and stirring each of the above compositions, the resulting solution was filtered with a filter to prepare actinic ray curable magenta ink 6. The ethylene oxide-added 1,6-hexanediol acrylate used here is a non-aqueous acrylic UV monomer.

(Preparation of black ink 6)
Carbon black (manufactured by Mitsubishi Chemical Corporation, MA-7) 10 parts Ajisper PB821 (manufactured by Ajinomoto Fine Techno) 3 parts Aronix M5700 (manufactured by Toagosei Co., Ltd.) 7 parts Ethylene oxide added 1,6 hexanediol acrylate 72 parts 3-methoxybutyl acrylate 8 Part Irgacure 369 (manufactured by Ciba Specialty Chemicals) 5 parts After mixing and stirring each of the above compositions, the resulting solution was filtered through a filter to prepare actinic ray curable black ink 6.

  Table 1 shows the polymer compound used for each pigment ink and the values of the contact angle between the pigment ink and the fabric. The contact angle was measured by the following method.

  The contact angle value is 0.2 seconds after 2 μl droplets of each pigment ink were dropped on the fabric in an environment of 23 ° C. and 50% RH. Measurement was performed using an automatic contact angle meter (CA-VP model manufactured by Kyowa Interface Science Co., Ltd.). As the fabric, the above-mentioned mercerized 100% cotton plain woven fabric (untreated) was used.

(Production and evaluation of print images)
Using the ink sets 1 to 6, printing was performed on the fabric using an inkjet printer (Nassenger KS-1600II (manufactured by Konica Corporation)). As the fabric, a plain weave fabric made of mercerized 100% cotton was used untreated.

  Each ink was continuously ejected, and 0.1 seconds after landing, a 120 W / cm metal halide lamp (MAL 400NL power supply power 3 kW · hr manufactured by Nihon Battery Co., Ltd.) was able to be irradiated.

  Thereafter, the printed matter was heat-fixed with a 120 ° C. iron.

(Evaluation of blur)
A black thin line having a width of 1 mm and a length of 5 cm was printed, visually observed, and bleeding was evaluated according to the following criteria.

○: Thin lines are reproduced without blurring due to bleeding Δ: Lines are slightly thick due to bleeding ×: Line thickening due to bleeding is severe, and thin lines cannot be reproduced.

(Evaluation of color bleed)
A black thin line having a width of 1 mm was printed on a magenta solid, then visually observed, and color bleeding was evaluated according to the following criteria.

○: The boundary between the fine line and the solid is clear. △: The occurrence of clear blur is observed at the boundary, and the line width is 1.5 times or more. ×: The boundary between the fine line and the solid is unclear. Quality and bleed resistance is extremely poor.

(concentration)
A black solid of 10 cm × 10 cm was printed, and the black density was measured with an X-Rite densitometer and evaluated according to the following criteria.

○: Black density 1.5 or more Δ: Black density 1.0 or more and less than 1.5 ×: Black density 1.0 or less.

(Fabric texture)
About said fabric, the black solid printing part and the non-printing part were simultaneously rubbed by hand, and the texture was evaluated.

○: There was almost no sense of incongruity between the printed part and unprinted. Δ: The printed part was somewhat awkward. ×: The printed part was swelled and there was a sense of discomfort. Table 2 shows the results.

  From Table 2, it can be seen that when an ink set containing the polymer compound of the present invention is used, bleeding and color bleeding are prevented and a high concentration is obtained.

Claims (8)

A step of ejecting ink droplets of a pigment ink containing at least water, a pigment, and a polymer compound having a plurality of side chains in a hydrophilic main chain from a recording head and attaching the ink droplets onto the fabric; Irradiating the ink with active energy rays and curing the ink, wherein the polymer compound is a polymer compound having a partial structure of a compound represented by the following general formula (5), An ink-jet printing method comprising cross-linking between the side chains by irradiation with active energy rays.

[Wherein R ₂ represents Me or H, n represents 1 or 2, X represents — (CH ₂ ) _m —COO—, —CH ₂ —COO— or —O—, and Y represents an aromatic ring or a single bond. , M represents an integer from 0 to 6]   2. The ink jet printing method according to claim 1, wherein the fabric is not pretreated.   3. The ink jet printing method according to claim 1, wherein the hydrophilic main chain of the polymer compound is a saponified product of polyvinyl acetate, and the degree of polymerization is 200 or more and 2000 or less.   The inkjet printing method according to any one of claims 1 to 3, wherein the polymer compound has a side chain modification rate of 0.3 mol% to 4 mol% with respect to the hydrophilic main chain.   The inkjet printing method according to any one of claims 1 to 4, wherein a contact angle between the pigment ink and the fabric is 40 to 100 degrees.   The inkjet printing method according to claim 1, wherein the pigment ink contains a photopolymerization initiator in an amount of 0.1% by mass or more and less than 1.0% by mass with respect to the total mass of the ink. .   The inkjet printing method according to claim 1, wherein the active energy rays are ultraviolet rays.   The ink jet textile printing method according to any one of claims 1 to 7, wherein a heat fixing process is performed after the pigment ink is attached to the fabric.