Overcoat liquid for printing, ink set and image formation method

Abstract

To provide an overcoat liquid for printing which has high wet friction fastness, while maintaining injection stability and feeling.SOLUTION: An overcoat liquid for printing contains a water-dispersible silicone resin, and water. A content of the water-dispersible silicone resin is 0.01 mass% or more and less than 15 mass% with respect to the overcoat liquid for printing.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an overcoat liquid for textile printing, an ink set, and an image forming method. [Background technology]

[0002] In recent years, ink-jet printing, in which an image is formed on a fabric by an ink-jet method, has become widely used as a textile printing method because it allows dyeing in a short time and has high production efficiency.

[0003] Dye inks have been the mainstream inks used in inkjet textile printing, but the use of pigment inks, which can omit post-treatment such as a washing step for washing away dye that has not dissolved or reacted, is being considered.

[0004] Pigment inks exhibit high color development by retaining pigment particles on the surface of the fabric, but tend to have poorer fixation of pigment particles and inferior friction fastness compared to dye inks. Therefore, studies have been conducted to improve the fixation of pigment particles and the friction fastness by adding a binder resin to the ink or by applying an overcoat liquid on the ink applied to the fabric.

[0005] As an overcoat liquid used in inkjet printing, an overcoat liquid containing a water-dispersible resin, a specific water-soluble organic solvent, a crosslinking component, and water has been disclosed. In the examples, an anionic urethane resin is used as the water-dispersible resin (see Patent Document 1). This document describes that the anionic urethane resin reacts with the crosslinking component to form a strong film on the ink coating, thereby improving the abrasion resistance.

[0006] In order to improve the resistance to friction, the inclusion of a water-soluble silicone resin in the ink (see Patent Document 2) or a silicone surfactant has been considered. In addition, the inclusion of a water-dispersible silicone resin in the pretreatment liquid has also been considered (see Patent Document 3). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2017-149812 A [Patent Document 2] JP 2013-194161 A [Patent Document 3] JP 2021-500437 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, when an overcoat liquid containing a urethane resin as in Patent Document 1 is used, a resin film is likely to be formed on the ink coating by heating. When the resin film is formed, there is a problem that the fabric tends to become hard and the texture is easily damaged.

[0009] In addition, in inkjet printing, it is particularly desirable to improve wet rub fastness. On the other hand, even if a water-soluble silicone resin is added to the ink as in Patent Document 2, or a water-dispersible silicone resin is added to the pretreatment liquid as in Patent Document 3, the silicone resin is unlikely to be present on the outermost surface, so wet rub fastness cannot be sufficiently improved. Furthermore, when a silicone surfactant is added to the ink, the viscosity tends to increase and the surface tension tends to decrease, and the ejection stability tends to decrease.

[0010] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide an overcoat liquid for textile printing, an ink set, and an image forming method that have high wet rub fastness while maintaining ejection stability and texture. [Means for solving the problem]

[0011] The present invention relates to the following overcoat liquid for textile printing, an ink set, and an image forming method.

[0012] [1] An overcoat liquid for textile printing, comprising: a water-dispersible silicone resin; and water, wherein the content of the water-dispersible silicone resin in the overcoat liquid for textile printing is 0.01% by mass or more and less than 15% by mass. [2] The overcoat liquid for textile printing according to [1], wherein the water-dispersible silicone resin has a glass transition temperature of less than 20°C. [3] The overcoat solution for textile printing according to [1] or [2], wherein the water-dispersible silicone resin is a copolymer containing a structural unit derived from a polyorganosiloxane having a radical polymerizable group, and a structural unit derived from a (meth)acrylic acid ester, vinyl acetate, and a urethane compound having a radical polymerizable group. [4] The overcoat liquid for textile printing according to any one of [1] to [3], wherein the water-dispersible silicone resin is an anionic silicone resin. [5] The overcoat solution for textile printing according to any one of [1] to [4], further comprising a water-soluble organic solvent. [6] An ink-jet ink containing a pigment, a binder resin, water, and a water-soluble organic solvent; and the overcoat liquid for textile printing according to any one of [1] to [5]; Including, an ink set. [7] The glass transition temperature of the water-dispersible silicone resin is equal to or higher than the glass transition temperature of the binder resin, and the difference between the glass transition temperature of the water-dispersible silicone resin and the glass transition temperature of the binder resin is 55° C. or less. The ink set according to [6]. [8] A method for forming an image, comprising: a step of applying, onto a fabric, an inkjet ink containing a pigment, a binder resin, water, and a water-soluble organic solvent by an inkjet system; and a step of applying the overcoat liquid for textile printing according to any one of [1] to [5] above onto the inkjet ink applied to the fabric. Effect of the Invention

[0013] According to the present invention, it is possible to provide an overcoat liquid for textile printing, an ink set, and an image forming method that have high wet rub fastness while maintaining ejection stability and texture. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present inventors have discovered that by using an overcoat liquid containing a water-dispersible silicone resin, it is possible to improve wet rub fastness while maintaining injection stability and texture.

[0015] That is, in the present invention, since the water-dispersible silicone resin is contained in the overcoat liquid rather than in the ink, the silicone resin can be unevenly distributed on the ink layer or near the surface of the ink layer, thereby sufficiently reducing the friction coefficient of the ink layer surface and improving wet friction fastness. Moreover, unlike water-soluble silicone compounds (including silicone surfactants), water-dispersible silicone resins are less likely to cause an increase in viscosity or a decrease in surface tension of the overcoat liquid. Furthermore, when water-dispersible silicone resins are contained in ink, the content of the silicone resin needs to be increased in order to distribute the silicone resin unevenly on the ink surface. In contrast, the content of the silicone resin in the overcoat liquid does not need to be increased, and the viscosity can be reduced. These factors can improve the ejection stability and texture.

[0016] Furthermore, by setting the Tg of the silicone resin in the overcoat liquid to a certain level or lower, or by setting the difference in Tg between the silicone resin in the overcoat liquid and the binder resin in the ink to a certain level or lower, the wet rub fastness can be more effectively improved.

[0017] That is, the wet rubbing fastness is an index for preventing color transfer to other fabrics even when wetted by washing, etc. In other words, since the wet rubbing fastness is evaluated in a wet state, the friction coefficient when rubbed is even greater than that of the dry rubbing fastness. Therefore, in order to more effectively improve the wet rubbing fastness, a higher fastness than that of the dry rubbing fastness is required. As described above, by using a water-dispersible silicone resin with a Tg of a certain level or less as the water-dispersible silicone resin, or by making the difference in Tg between the binder resin in the ink and the silicone resin in the overcoat liquid to a certain level or less, it is possible not only to reduce the friction coefficient, but also to make the ink layer and the overcoat layer more compatible with each other and to further reduce the interface, thereby more effectively improving wet friction fastness.

[0018] Hereinafter, the constitution of the overcoat liquid for textile printing according to one embodiment of the present invention will be described.

[0019] 1. Overcoat solution for textile printing An overcoat liquid for textile printing according to one embodiment of the present invention (hereinafter, also simply referred to as an "overcoat liquid") contains a water-dispersible silicone resin and water.

[0020] 1-1. Water-dispersible silicone resin The water-dispersible silicone resin is a silicone resin that exists in a dispersed state as resin particles in an aqueous medium. The overcoat liquid according to the present embodiment is an aqueous overcoat liquid containing water and any water-soluble organic solvent. Therefore, the silicone resin is also contained as resin particles in the overcoat liquid. Whether or not the silicone resin exists as resin particles can be confirmed by whether or not there is a peak corresponding to the water-dispersible silicone resin when the dispersed particle size (Z average) of the overcoat liquid is measured with a particle size measuring device (e.g., Zataizer Nano S90 manufactured by Melvern).

[0021] The silicone resin is a polymer containing a structural unit derived from polyorganosiloxane. The polymer may be a homopolymer consisting of a structural unit derived from polyorganosiloxane, or a copolymer containing a structural unit derived from polyorganosiloxane and a structural unit derived from another polymerizable monomer (including a macromonomer) that is copolymerizable therewith.

[0022] The copolymer may be, for example, a graft copolymer in which a structural unit derived from polyorganosiloxane is graft-polymerized with a (meth)acrylic acid ester or the like (polymerizable monomer), or a copolymer in which a side chain or end of a (meth)acrylic resin or the like is modified with a polyorganosiloxane. Among them, a graft copolymer in which a (meth)acrylic acid ester or the like is graft-polymerized with a polymer containing a structural unit derived from polyorganosiloxane is preferred. Such a graft copolymer has a structure in which the polyorganosiloxane portion is the trunk portion and the (meth)acrylic acid ester or the like is the branch portion, and therefore is more compatible with the binder resin contained in the ink layer, which is preferred. The form of copolymerization is not limited to graft copolymerization, and may be random copolymerization or block copolymerization.

[0023] The silicone resin may also have an ionic group. The ionic group of the silicone resin may be an ionic group that forms a pair with the ionic group of the fabric (or the ionic group of the flocculant attached to the fabric). For example, since the flocculant usually has a cationic group, the silicone resin may be an anionic silicone resin that has an anionic group. Examples of the anionic group include a carboxyl group, a sulfonic acid group, and a phosphonic acid group.

[0024] That is, the silicone resin preferably contains a structural unit derived from a polyorganosiloxane having a radically polymerizable group, and a structural unit derived from another polymerizable monomer copolymerizable therewith.

[0025] Examples of polyorganosiloxanes having a radical polymerizable group include polyorganosiloxanes represented by the following formula (1). [ka]

[0026] In the above formula (1), R 1 , R 2 and R 3are each independently a hydrocarbon group having 1 to 10 carbon atoms. Y is a radically polymerizable group selected from the group consisting of a vinyl group, an allyl group, and a γ-(meth)acryloxypropyl group. X 1 and X 2 each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or SiR 4 R 5 R 6 (R 4 , R 5 each independently represents a hydrocarbon group having 1 to 10 carbon atoms; R 6 represents a hydrocarbon group having 1 to 10 carbon atoms or a radical polymerizable group selected from the group consisting of a vinyl group, an allyl group, and a γ-(meth)acryloxypropyl group). m is an integer of 1 to 10000. n is an integer of 1 or more. The siloxane chain may be branched.

[0027] Examples of other polymerizable monomers include (meth)acrylic acid esters, vinyl acetate, urethane compounds having a radical polymerizable group, etc. In this specification, (meth)acrylic means acrylic, methacrylic, or both of these.

[0028] The (meth)acrylic acid ester is an alkyl ester, a hydroxyalkyl ester, or an alkoxyalkyl ester of (meth)acrylic acid. Examples of the (meth)acrylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-methoxyethyl (meth)acrylate. Among them, methyl methacrylate and 2-hydroxyethyl methacrylate are preferred.

[0029] Examples of urethane compounds having a radical polymerizable group include compounds obtained by reacting polyols, polyisocyanates, silicone compounds having two hydroxyl groups, and isocyanate compounds having (meth)acryloyl groups. As the polyols and polyisocyanates, the same polyols and polyisocyanates as those for obtaining the urethane resin as the binder resin of the ink described later can be used.

[0030] The content of the structural unit derived from polyorganosiloxane in the silicone resin is preferably 50% by mass or more, more preferably 60% by mass or more and 95% by mass or less, based on the total amount of the structural units constituting the silicone resin. When the content of the structural unit derived from polyorganosiloxane is 50% by mass or more, the effect of reducing the friction coefficient derived from polysiloxane is more easily obtained, and the wet friction fastness can be further improved. When the content of the structural unit derived from polyorganosiloxane is 95% by mass or less, the adhesion between the ink layer and the overcoat layer is more easily improved due to the affinity between other compounds and the binder resin in the ink layer.

[0031] The silicone resin may further include a structural unit derived from a polymerizable monomer other than the above. Examples of the polymerizable monomer other than the above include ethylenically unsaturated carboxylic acids such as (meth)acrylic acid, styrenes, etc. For example, the silicone resin may further include a structural unit derived from an ethylenically unsaturated carboxylic acid such as (meth)acrylic acid, from the viewpoint of exhibiting anionicity.

[0032] The graft copolymerization can be carried out by a known method. For example, the polyorganosiloxane represented by the above formula (1) and a copolymerizable compound such as a (meth)acrylic acid ester are emulsified and dispersed in water, and polymerized in the presence of a radical polymerization initiator to carry out the graft copolymerization.

[0033] Examples of commercially available silicone-(meth)acrylic copolymers include Chaline LC190, Chaline R-170, R170S, Chaline FE-230N, FE-502, and R-170BX (manufactured by Nissin Chemical Industry Co., Ltd.). Examples of commercially available silicone-urethane copolymers include Chaline RU-911 (manufactured by Nissin Chemical Industry Co., Ltd.). Examples of commercially available silicone-vinyl acetate copolymers include Chaline 1827 (manufactured by Nissin Chemical Industry Co., Ltd.).

[0034] The glass transition temperature (Tg) of the silicone resin is preferably moderately low in terms of making it easier to maintain the texture and improving the wet friction fastness. Specifically, the Tg of the silicone resin is preferably less than 20°C, and more preferably 0°C or lower. Thus, a silicone resin with a low Tg, particularly a silicone resin with a Tg of less than 20°C, is soft and therefore can prevent the texture from being damaged. Furthermore, such a silicone resin is easy to follow the ink layer and is less likely to peel off the overcoat layer at the interface between the ink layer and the overcoat layer, so that the wet friction fastness can be improved. The lower limit of the Tg of the silicone resin is not particularly limited, but can be, for example, -60°C or higher in terms of improving the wet friction fastness. The Tg of the silicone resin can be measured by differential scanning calorimetry in accordance with JIS K 7121 at a temperature rise rate of 10°C / min.

[0035] It is preferable that the difference between the Tg(OC) of the silicone resin of the overcoat liquid and the Tg(IN) of the binder resin of the ink is small. The Tg of the resin of the overcoat liquid can be set to be equal to or higher than the Tg of the binder resin of the ink. In this embodiment, by reducing the difference (Tg(OC)-Tg(IN)) between the Tg(OC) of the silicone resin of the overcoat liquid and the Tg(IN) of the binder resin of the ink, the binder resin in the ink layer and the silicone resin of the overcoat layer become more compatible with each other, and an interface between the ink layer and the overcoat layer is less likely to be formed. As a result, when the surface of the image-formed product is rubbed, the interface between the ink layer and the overcoat layer is less likely to peel off, and wet friction fastness can be more effectively improved. Specifically, the difference in Tg is more preferably 55°C or less, and even more preferably 40°C or less.

[0036] The Tg of the silicone resin can be adjusted by the type and amount of modification, for example, the content of structural units derived from other compounds such as (meth)acrylic acid esters. If the content of structural units derived from other compounds is high, the Tg tends to be low.

[0037] The average particle size of the silicone resin in the aqueous dispersion used to prepare the overcoat liquid is not particularly limited, but is preferably 150 nm or more and 300 nm or less, for example, from the viewpoint of ejection stability by inkjet. The average particle size is the average value of the primary particle size. The average particle size can be measured as the dispersed particle size (Z average) using, for example, Zataizer Nano S90 manufactured by Melvern.

[0038] The acid value of the silicone resin is not particularly limited, but is preferably low from the viewpoint of further improving wet friction fastness and water resistance. Specifically, the acid value of the silicone resin is preferably lower than the acid value of the binder resin contained in the ink, more preferably 100 mgKOH / g or less, and even more preferably 0.1 mgKOH / g or more and 50 mgKOH / g or less. The acid value of the silicone resin can be measured according to JIS K 0070.

[0039] The content of the silicone resin is preferably 0.01% by mass or more and less than 15% by mass with respect to the overcoat liquid. If the content is 0.01% by mass or more, the silicone resin is more likely to be unevenly distributed on the surface, and wet friction fastness is more likely to be improved. If the content is less than 15% by mass, deterioration of texture and deterioration of injection stability due to excessive adhesion of the silicone resin can be further suppressed. From the same viewpoint, the content is more preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.2% by mass or more and 8% by mass or less.

[0040] 1-2. Water-soluble organic solvents The overcoat liquid preferably further contains a water-soluble organic solvent, which can further improve ejection stability by inkjet printing.

[0041] The water-soluble organic solvent is not particularly limited as long as it is compatible with water, and examples thereof include polyhydric alcohols (e.g., dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and polypropylene glycol, and trihydric or higher alcohols such as glycerin, trimethylolpropane, and hexanetriol); polyhydric alcohol ethers (e.g., ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and diethylene glycol dimethyl ether); monohydric alcohols (e.g., methanol, ethanol, propanol, pentanol, hexanol, cyclohexanol, benzyl alcohol); amines (e.g., ethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine); amides (e.g., formamide, N,N-dimethylformamide, N,N-dimethylacetamide); heterocycles (e.g., 2-pyrrolidone, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidine), sulfoxides (e.g., dimethyl sulfoxide); and sulfones (e.g., sulfolane).

[0042] From the viewpoint of further improving ejection stability by inkjet, the water-soluble organic solvent preferably contains a water-soluble organic solvent having a boiling point of 180° C. or higher, preferably 190° C. or higher, and more preferably 200° C. or higher. Examples of water-soluble organic solvents having a boiling point of 180° C. or higher include dihydric alcohols such as ethylene glycol (boiling point 197° C.), 1,3-butanediol (boiling point 208° C.), 1,6-hexanediol (boiling point 223° C.), and polypropylene glycol; and trihydric or higher alcohols such as glycerin (boiling point 290° C.) and trimethylolpropane (boiling point 295° C.).

[0043] The content of the water-soluble organic solvent in the overcoat liquid is, for example, preferably from 10% by mass to 65% by mass, and more preferably from 20% by mass to 45% by mass.

[0044] The content of water in the overcoat liquid is from 30% by mass to 85% by mass, and preferably from 50% by mass to 75% by mass.

[0045] 1-3.Other ingredients The overcoat solution may further contain other components in addition to those described above, if necessary. Examples of the other components include a surfactant, a preservative, etc.

[0046] The surfactant can reduce the surface tension of the overcoat liquid and increase the wettability of the liquid to the fabric. The type of surfactant is not particularly limited, and may be, for example, an acetylene glycol surfactant, a silicone surfactant, or a fluorine surfactant.

[0047] Examples of preservatives or antifungal agents include aromatic halogen compounds (eg, Preventol CMK), methylene dithiocyanate, halogen-containing nitrogen-sulfur compounds, 1,2-benzisothiazolin-3-one (eg, PROXEL GXL), and the like.

[0048] In order to make it easier to distribute the silicone resin unevenly on the surface of the image-formed product, it is preferable that the overcoat liquid is substantially free of coloring materials such as pigments, etc. "Substantially free" means that the amount of coloring materials is 0.1% by mass or less, and preferably 0% by mass, relative to the overcoat liquid.

[0049] 1-4.Physical properties The viscosity of the overcoat liquid at 25°C is not particularly limited, but from the viewpoint of improving ejection stability, for example, when applying by inkjet, the viscosity is preferably from 2 mPa·s to 11 mPa·s, and more preferably from 3 mPa·s to 7 mPa·s. The viscosity of the overcoat liquid can be measured at 25°C using an E-type viscometer. The viscosity of the overcoat liquid can be adjusted by the content of the silicone resin and the composition of the solvent (for example, the content of polyhydric alcohols).

[0050] The static surface tension of the overcoat liquid at 25°C is not particularly limited, but from the viewpoint of further enhancing the wettability to the fabric, when applying the overcoat liquid by inkjet, for example, the static surface tension is preferably from 20 mN / m to 50 mN / m, and more preferably from 30 mN / m to 50 mN / m.

[0051] The static surface tension of the overcoat liquid can be measured by the Wilhelmy method at 25° C. Specifically, the static surface tension of the overcoat liquid can be measured using DY-300 manufactured by Kyowa Interface Science Co., Ltd. in accordance with JIS K2241.

[0052] 1-5.Applications The overcoat liquid is preferably used in combination with the inks described below. That is, the overcoat liquid can be combined with the inks described below to form an ink set.

[0053] 2. Ink set An ink set according to one embodiment of the present invention comprises the above-described overcoat liquid and ink.

[0054] 2-1.Ink The ink contains a pigment, a binder resin, and water.

[0055] 2-1-1.Pigments The pigment is not particularly limited, but may be, for example, an organic or inorganic pigment having the following numbers as described in the Color Index:

[0056] Examples of orange pigments include CI Pigment Orange 31, 43.

[0057] Examples of red or magenta pigments include Pigment Red 3, 5, 19, 22, 31, 38, 43, 48:1, 48:2, 48:3, 48:4, 48:5, 49:1, 53:1, 57:1, 57:2, 58:4, 63:1, 81, 81:1, 81:2, 81:3, 81:4, 88, 104, 108, 112, 122, 123, 144, 146, 149, 166, 168, 169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, Pigment Violet 3, 19, 23, 29, 30, 37, 50, 88, Pigment Orange 13, 16, 20, 36.

[0058] Examples of blue or cyan pigments include Pigment Blue 1, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17-1, 22, 27, 28, 29, 36, 60.

[0059] Examples of green or yellow pigments include Pigment Green 7, 26, 36, and 50. Examples of yellow pigments include Pigment Yellow 1, 3, 12, 13, 14, 15, 17, 34, 35, 37, 55, 74, 81, 83, 93, 94, 95, 97, 108, 109, 110, 128, 137, 138, 139, 151, 153, 154, 155, 157, 166, 167, 168, 180, 185, 193, and 213.

[0060] Examples of black pigments include Pigment Black 7, 28, and 26.

[0061] Examples of white pigments include titanium dioxide and the like.

[0062] From the viewpoint of improving dispersibility in the ink, the pigment is preferably further dispersed with a pigment dispersant, which will be described later.

[0063] The pigment may be a self-dispersing pigment. A self-dispersing pigment is a pigment particle whose surface is modified with a group having a hydrophilic group, and has pigment particles and hydrophilic groups bonded to the surface of the pigment particles.

[0064] Examples of hydrophilic groups include carboxyl groups, sulfonic acid groups, and phosphorus-containing groups. Examples of phosphorus-containing groups include phosphoric acid groups, phosphonic acid groups, phosphinic acid groups, phosphite groups, and phosphate groups.

[0065] Commercially available examples of self-dispersing pigments include Cabot's Cab-0-Jet® 200K, 250C, 260M, and 270V (sulfonic acid group-containing self-dispersing pigments), Cab-0-Jet® 300K (carboxylic acid group-containing self-dispersing pigments), and Cab-0-Jet® 400K, 450C, 465M, 470V, and 480V (phosphate group-containing self-dispersing pigments).

[0066] The pigment content is not particularly limited, but from the viewpoint of easily adjusting the viscosity of the ink within the above range and enabling the formation of a high-density image, it is preferably 0.3% by mass to 10% by mass, and more preferably 0.5% by mass to 6% by mass. When the pigment content is equal to or greater than the lower limit, the color of the image tends to be more vivid. When the pigment content is equal to or less than the upper limit, the viscosity of the ink does not become too high, and ejection stability is not easily impaired.

[0067] 2-1-2. Binder resin The binder resin can have a function of fixing the pigment to the fabric. From the viewpoint of improving water resistance, the binder resin is preferably a water-dispersible resin. The water-dispersible resin is dispersed as resin particles in the ink containing the aqueous medium, similar to the silicone resin.

[0068] The water-dispersible resin, like the silicone resin, may have an ionic group that forms a pair with the ionic group in the fabric (or the ionic group in the flocculant attached to the fabric), or may have an anionic group.

[0069] The Tg of the water-dispersible resin (binder resin) is not particularly limited, but is preferably low. This is because the fabric is less likely to become hard even after image formation, and the texture is easily maintained. Specifically, the Tg of the water-dispersible resin is preferably 50°C or lower, more preferably 0°C or lower, and even more preferably -35°C or lower. The lower limit of the Tg of the water-dispersible resin is not particularly limited, but can be, for example, -70°C or higher. The Tg of the water-dispersible resin can be measured by the same method as the Tg of the silicone resin.

[0070] The Tg of the water-dispersible resin can be adjusted by the type of water-dispersible resin and the monomer composition. For example, in the case of (meth)acrylic resin, the Tg tends to be lowered by increasing the content of the structural unit (a) derived from alkyl acrylate. In the case of urethane resin, the Tg tends to be lowered by increasing the content of the soft unit.

[0071] The type of water-dispersible resin is not particularly limited as long as the Tg satisfies the above range. Examples of water-dispersible resins include (meth)acrylic resins, polyurethane resins, polyester resins, etc. Among them, (meth)acrylic resins and polyurethane resins are preferred from the viewpoint of having good flexibility and being able to more easily maintain the texture of the fabric.

[0072] ((Meth)acrylic resin) The (meth)acrylic resin is a polymer containing structural units derived from a (meth)acrylic monomer.

[0073] The (meth)acrylic monomer is a monomer having a (meth)acryloyl group, and examples thereof include (meth)acrylic acid, (meth)acrylic acid alkyl esters, (meth)acrylamides, etc. Among these, (meth)acrylic acid alkyl esters are preferred.

[0074] That is, the (meth)acrylic resin contains a structural unit (a) derived from a (meth)acrylic acid alkyl ester, and from the viewpoint of improving water dispersibility and coagulation properties, it is preferable that the (meth)acrylic resin further contains a structural unit (b) derived from an unsaturated compound having an anionic group.

[0075] The structural unit (a) is derived from a (meth)acrylic acid alkyl ester. From the viewpoint of lowering the Tg of the resin, the (meth)acrylic acid alkyl ester preferably contains an acrylic acid alkyl ester. The number of carbon atoms in the alkyl group of the acrylic acid alkyl ester is, for example, 1 or more and 20 or less, preferably 4 or more and 12 or less, and more preferably 4 or more and 8 or less. Examples of the acrylic acid alkyl ester include butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, and 2-ethylhexyl acrylate, and the like, and butyl acrylate is preferred.

[0076] The (meth)acrylic acid alkyl ester may be used alone or in combination of two or more kinds. For example, an acrylic acid alkyl ester and a methacrylic acid alkyl ester may be used in combination.

[0077] The content of the structural unit (a) is not particularly limited, but is preferably 70 to 96% by mass based on all structural units constituting the (meth)acrylic resin. When the content is 70% by mass or more, the Tg of the resin is easily lowered. When the content is 96% by mass or less, the abrasion resistance and the like are less likely to be impaired. From the same viewpoint, the content is more preferably 80 to 90% by mass based on all structural units constituting the (meth)acrylic resin.

[0078] The structural unit (b) is derived from an unsaturated compound having an anionic group. Examples of unsaturated compounds having a carboxy group include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, and 2-acryloyloxyethyl succinic acid. Examples of unsaturated compounds having a sulfonic acid group include vinyl sulfonic acid, styrene sulfonic acid, and allyl sulfonic acid. Examples of unsaturated compounds having a phosphoric acid group include vinyl phosphonic acid and 2-((meth)acryloyloxy)ethyl phosphate. Among these, ethylenically unsaturated carboxylic acids are preferred.

[0079] The content of the structural unit (b) is not particularly limited, but is preferably 3 to 15% by mass based on all structural units constituting the (meth)acrylic resin. When the content is 3% by mass or more, the dispersibility and coagulation of the water-dispersible resin in the ink are more likely to be improved. When the content is 15% by mass or less, the viscosity of the ink is less likely to increase, and the ejection stability is less likely to be impaired. From the same viewpoint, the content of the structural unit (b) is more preferably 3 to 10% by mass based on all structural units constituting the (meth)acrylic resin.

[0080] The (meth)acrylic resin may further contain a structural unit (c) derived from a monomer other than the above. Examples of the other monomer include monofunctional monomers such as ethylenically unsaturated carboxylic acids (e.g., maleic acid, itaconic acid); styrenes (e.g., styrene, α-methylstyrene, vinyl toluene); saturated fatty acid vinyls (e.g., vinyl acetate, vinyl propionate); vinyl compounds (e.g., 1,4-divinyloxybutane, divinylbenzene, etc.); allyl compounds (e.g., diallyl phthalate, triallyl cyanurate, etc.); and acrylamide; and difunctional or higher monomers such as polyfunctional (meth)acrylates such as diethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, propylene glycol di(meth)acrylate, and N,N'-methylenebis(acrylamide), and polyfunctional acrylamide.

[0081] Examples of commercially available (meth)acrylic resins include EMN-325 (Acrylate, manufactured by Nippon Shokubai Co., Ltd., acrylic elastomer, Tg: -50°C), EMN-326 (Acrylate, manufactured by Nippon Shokubai Co., Ltd., acrylic elastomer, Tg: -50°C), and the like.

[0082] (urethane resin) The urethane resin is a thermoplastic urethane resin. The thermoplastic urethane resin may be, for example, a reaction product of a low molecular weight diol as a chain extender, a polyisocyanate, and a polyol. The urethane resin is preferably a self-emulsifying type. The self-emulsifying type urethane resin may be, for example, a reaction product of a low molecular weight diol as a chain extender, a polyisocyanate having an anionic group, and a polyol.

[0083] The low molecular weight diol is a difunctional aliphatic oligomer of glycol. Typical difunctional aliphatic oligomers of glycol include, for example, ethylene glycol, propylene glycol, 1,4 butanediol, 1,6 hexanediol, and the like.

[0084] The polyisocyanate is preferably a diisocyanate, examples of which include aromatic diisocyanates such as diphenylmethane diisocyanate, e.g., 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate; Examples of the diisocyanate include aliphatic diisocyanates such as 4,4'-dicyclohexylmethane diisocyanate and 2,4'-dicyclohexylmethane diisocyanate.

[0085] The polyol may be a polyester polyol or a polyether polyol. Examples of polyester polyols may be reaction products of polycarboxylic acids and polyols. Examples of polycarboxylic acids include malonic acid, citric acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, terephthalic acid, and phthalic acid. Examples of polyols to be reacted with polycarboxylic acids include trimethylolpropane, trimethylolethane, 2-methylglucoside, sorbitol, low molecular weight polyols such as polyoxyethylene glycol, polyoxypropylene glycol, and block heteropolyoxyethylene-polyoxypropylene glycol.

[0086] Thermoplastic polyurethanes contain hard and soft segments in the molecule. The hard segments are mainly generated by the reaction of polyisocyanate with low molecular weight diol; the soft segments can be mainly generated by the reaction of polyol.

[0087] The mass ratio of the hard segment to the soft segment in the polymer chain of the thermoplastic polyurethane is, for example, 75 / 25 to 15 / 85 (mass ratio), preferably 60 / 40 to 25 / 75 (mass ratio). From the viewpoint of lowering Tg, the mass ratio of the soft segment may be increased, for example, the mass ratio of the soft segment may be higher than that of the hard segment.

[0088] An example of a commercially available thermoplastic polyurethane product is Elastollan 1185A (manufactured by BASF, thermoplastic polyurethane elastomer, Tg: -41°C).

[0089] (General) The acid value of the water-dispersible resin is not particularly limited, and is preferably 15 mgKOH / g or more and 100 mgKOH / g or less, and more preferably 20 mgKOH / g or more and 80 mgKOH / g or less. The acid value of the water-dispersible resin may be the same as or higher than the acid value of the silicone resin contained in the overcoat liquid. The acid value of the water-dispersible resin can be measured according to JIS K 0070.

[0090] The acid value of the water-dispersible resin can be adjusted by the content of the structural unit (b). For example, the acid value increases when the content of the structural unit (b) derived from an unsaturated compound having an acidic group is increased.

[0091] The average particle size of the water-dispersible resin in the aqueous dispersion used to prepare the ink can be, for example, 100 nm or less. The average particle size can be measured in the same manner as above.

[0092] The weight average molecular weight of the water-dispersible resin is not particularly limited, but from the viewpoint of improving wet friction fastness, it is preferable that it is high, for example, from 10,000 to 1,000,000. On the other hand, from the viewpoint of making it easier to improve the texture, it is preferable that the weight average molecular weight of the water-dispersible resin is low, and it is preferably 10,000 or less. The weight average molecular weight of the water-dispersible resin can be measured by the same method as above.

[0093] The content of the binder resin is not particularly limited, but is preferably 1% by mass or more and 20% by mass or less with respect to the ink. When the content of the binder resin is 1% by mass or more, the fixation of the ink to the fabric is more easily improved. When the content of the binder resin is 20% by mass or less, the texture is less likely to be impaired. From the same viewpoint, the content of the binder resin is more preferably 5% by mass or more and 15% by mass or less with respect to the ink.

[0094] The water content is, for example, from 20% by mass to 70% by mass, and preferably from 30% by mass to 60% by mass, based on the ink.

[0095] 2-1-3.Other ingredients The ink may further contain other components as necessary. Examples of the other components include a water-soluble organic solvent, a pigment dispersant, a surfactant, a preservative, an antifungal agent, a pH adjuster, and the like.

[0096] (Water-soluble organic solvent) The water-soluble organic solvent may be the same as that used in the overcoat liquid. The content of the water-soluble organic solvent in the ink is, for example, 20% by mass to 70% by mass, and preferably 30% by mass to 60% by mass.

[0097] (Pigment dispersant) The pigment dispersant is present in the ink so as to surround the surface of the pigment particle or is adsorbed to the surface of the pigment particle to form a pigment dispersion liquid and disperse the pigment well. The pigment dispersant is preferably a polymer dispersant, and more preferably an anionic polymer dispersant.

[0098] The anionic polymer dispersant is a polymer dispersant having a hydrophilic group such as a carboxylic acid group, a phosphorus-containing group, or a sulfonic acid group, and is preferably a polymer dispersant having a carboxylic acid group.

[0099] The polymer dispersant having a carboxylic acid group may be a polycarboxylic acid or a salt thereof. Examples of the polycarboxylic acid include (co)polymers of monomers selected from acrylic acid or a derivative thereof, maleic acid or a derivative thereof, itaconic acid or a derivative thereof, and fumaric acid or a derivative thereof, and salts thereof. Examples of other monomers constituting the copolymer include styrene and vinylnaphthalene.

[0100] From the viewpoint of dispersing pigment particles sufficiently, the anionic group equivalent of the anionic polymer dispersant is preferably, for example, 1.1 meq / g or more and 3.8 meq / g or less. When the anionic group equivalent is within the above range, high pigment dispersibility is easily obtained without increasing the molecular weight of the anionic polymer dispersant. The anionic group equivalent of the anionic polymer dispersant can be determined from the acid value. The acid value can be measured in accordance with JIS K0070.

[0101] The weight average molecular weight (Mw) of the polymer dispersant is not particularly limited, but is preferably 5000 or more and 30000 or less. When the Mw of the polymer dispersant is 5000 or more, the pigment particles can be dispersed sufficiently, and when it is 30000 or less, the ink does not thicken too much, so that the permeability into the fabric is not easily impaired. The Mw of the polymer dispersant can be measured by the same method as above.

[0102] The content of the polymer dispersant is not particularly limited as long as it is within a range in which the pigment particles are sufficiently dispersed and the viscosity is such that the permeability into the fabric is not impaired. However, the content is preferably from 20% to 100% by mass, and more preferably from 25% to 60% by mass, relative to the pigment.

[0103] (Other additives) The surfactants, preservatives, antifungal agents, and pH adjusters that can be contained in the ink may be the same as the surfactants, preservatives, antifungal agents, and pH adjusters that can be contained in the overcoat liquid.

[0104] 2-4.Physical properties The viscosity of the ink at 25°C is not particularly limited as long as it provides good ejection properties using the inkjet method, but is preferably 3 mPa·s to 20 mPa·s, and more preferably 4 mPa·s to 12 mPa·s. The ink viscosity can be measured at 25°C using an E-type viscometer.

[0105] 3.Image forming method An image forming method according to one embodiment of the present invention includes the steps of 1) applying an ink onto a fabric by an inkjet method, and 2) applying an overcoat liquid onto the ink applied to the fabric. In this embodiment, the ink and overcoat liquid used are the ink and overcoat liquid described above, respectively.

[0106] 3-1. Ink application process The ink is applied onto the fabric by an inkjet method.

[0107] The fibers constituting the fabric are not particularly limited, and include natural fibers such as cotton (cellulose fiber), hemp, wool, and silk; chemical fibers such as rayon, vinylon, nylon, acrylic, polyurethane, polyester, and acetate, and blended fibers thereof. Among these, the fibers constituting the fabric may be hydrophilic fibers such as cotton, hydrophobic fibers such as polyester, or blended fibers thereof. The fabric may be any form of these fibers, such as woven fabric, nonwoven fabric, knitted fabric, etc. The fabric may be a blended woven fabric or blended nonwoven fabric of two or more types of fibers.

[0108] The fabric may have an aggregating agent attached thereto for aggregating the pigments and the like in the ink. That is, a treated fabric containing the fabric and the aggregating agent attached thereto may be used. This makes it easier to aggregate the pigments and water-dispersible resins in the ink on the fabric.

[0109] Next, the ink applied onto the fabric may be further dried, or a post-treatment step (a step of applying an overcoat liquid wet-on-wet) described below may be carried out before the ink is completely dried. Applying an overcoat liquid wet-on-wet means applying the overcoat liquid before most of the ink droplets applied earlier have completely dried. Specifically, this means that the ratio (amount of ink remaining when applying the overcoat liquid) / (amount of ink attached) per unit area of ​​the recording region is 0.40 or more and 1.0 or less, preferably 0.50 or more and 1.0 or less, more preferably 0.70 or more and 1.0 or less, and even more preferably 0.80 or more and 1.0 or less. The amount of ink applied is, for example, 15 g / m 2 Less than 15 g / m 2 It can be said that:

[0110] 3-2. Post-processing process Next, the overcoat liquid is applied onto the ink applied to the fabric, whereby the silicone resin of the overcoat liquid adheres to the fabric so as to cover the pigment, thereby improving the fixation of the pigment while reducing the coefficient of friction of the surface and improving the slipperiness.

[0111] The method for applying the overcoat liquid is not particularly limited, and may be any of a dipping method, a spray method, and an ink-jet method, but is preferably the ink-jet method.

[0112] The amount of the overcoat liquid applied is preferably 0.03 g / m 2 More than 2.2g / m 2 Less than or equal to 0.03 g / m 2 More than 1.2g / m 2 When the amount of the silicone resin attached is within the above range, the texture of the fabric can be further improved.

[0113] Next, the overcoat liquid applied onto the fabric may be further dried.

[0114] The ink and overcoat liquid are dried by removing the solvent and the like contained in each liquid applied to the fabric. The drying method is not particularly limited, and may be performed at room temperature or by heating. The heating method may be a method using a heater, a hot air dryer, a heating roller, or the like, and is preferably a method of heating both sides of the fabric using a hot air dryer and a heater.

[0115] The drying temperature is not particularly limited as long as it is a temperature at which the water-soluble organic solvent and water in the ink and overcoat liquid can be removed, and can be, for example, from 80° C. to 180° C. The drying time depends on the drying temperature, but can be, for example, from 1 minute to 10 minutes.

[0116] 3-3. Other processes The image forming method according to the present embodiment may further include other steps as necessary. For example, a step of pretreating the fabric may be further carried out before the above step 2).

[0117] In the pretreatment step, for example, the fabric is brought into contact with a pretreatment liquid containing a flocculant, and then dried to obtain a fabric to which the flocculant is attached.

[0118] (Pretreatment solution) The pretreatment liquid contains an aggregating agent and water. The type of aggregating agent may be any agent that aggregates the pigments and the like contained in the ink, and may be one that utilizes a change in pH or one that utilizes an electrical effect.

[0119] Examples of flocculants that cause flocculation by changing the pH include organic acids, such as carboxylic acids having 6 or less carbon atoms, saturated fatty acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, and hexanoic acid, and hydroxy acids such as lactic acid, malic acid, and citric acid.

[0120] The flocculant that causes aggregation by electrical action includes a polyvalent metal salt, and a compound having a cationic group or an anionic group. For example, when the pigment dispersant contained in the ink is anionic, the flocculant preferably includes a polyvalent metal salt or a compound having a cationic group.

[0121] Polyvalent metal salts can be water-soluble compounds having a divalent or higher polyvalent metal ion and an anion associated with it. Examples of polyvalent metal ions include Ca 2+ , Cu 2+ , Ni 2+ , Mg 2+ , Zn 2+ , B.A. 2+ Divalent metal ions such as Al 3+ , Fe 3+ , Cr 3+ Examples of anions include trivalent metal ions such as Cl. - , I - , Br - , SO4 2- , ClO3 - , NO3 - , and H.C.O.O. - , CH3COO - Among these, calcium salts and magnesium salts are preferred, and calcium nitrate and calcium chloride are more preferred.

[0122] The cationic group in the compound having a cationic group includes a secondary amino group, a tertiary amino group, a quaternary ammonium base, etc. Examples of the compound having a cationic group include the above-mentioned cationic urethane compound. In addition, cationic resins such as cationic urethane resin, cationic olefin resin, and cationic allylamine resin may be used.

[0123] The pretreatment liquid may further contain, as necessary, a water-soluble organic solvent, a pH adjuster, a preservative, etc. The water-soluble organic solvent, the pH adjuster, the preservative, etc. may be the same as the water-soluble organic solvent, the pH adjuster, the preservative, etc. used in the overcoat liquid.

[0124] The method of contacting with the pretreatment liquid may be the same as the method described above. The amount of the coagulant attached is not particularly limited, but may be, for example, 0.1 g / m 2 More than 5.0g / m 2 It could be the following:

[0125] 4. Image formation The image-formed product according to this embodiment includes a fabric, an ink layer, and an overcoat layer.

[0126] The ink layer is a layer derived from the ink, and contains components derived from the ink, that is, a pigment and a binder resin.

[0127] The overcoat layer is a layer derived from the overcoat liquid. The overcoat layer contains a component derived from the overcoat liquid, i.e., the silicone resin. It is preferable that there is no clear interface between the ink layer and the overcoat layer, and that the composition changes continuously. This is because the adhesion between the ink layer and the overcoat layer is increased, and interfacial peeling can be further suppressed.

[0128] As described above, the overcoat liquid according to the present embodiment is suitable for image formation using the inkjet method, but can also be used for purposes other than image formation using the inkjet method. EXAMPLES

[0129] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these.

[0130] 1.Material 1-1.Water dispersible resin (1) Silicone resin Silicone resin 1: Chaline FE-230N (manufactured by Nissin Chemical Industry Co., Ltd., silicone-acrylic graft copolymer, anionic, Tg = -50°C) Silicone resin 2: Chaline FE-502 (manufactured by Nissin Chemical Industry Co., Ltd., silicone-acrylic graft copolymer, anionic, Tg = -16°C) Silicone resin 3: Chaline RU-911 (manufactured by Nissin Chemical Industry Co., Ltd., silicone-urethane graft copolymer, anionic, Tg = -20°C) Silicone resin 4: Chaline E-371 (manufactured by Nissin Chemical Industry Co., Ltd., silicone-acrylic graft copolymer, anionic, Tg = 105°C) Silicone resin 5: Chaline 1827 (manufactured by Nissin Chemical Industry Co., Ltd., silicone-vinyl acetate graft copolymer, anionic, Tg = 30°C)

[0131] (Tg) The Tg of the silicone resin is a value measured by differential scanning calorimetry in accordance with JIS K 7121 at a temperature rise rate of 10° C. / min.

[0132] (Measurement of average particle size and acid value) The dispersed particle size (Z average) of each of the silicone resins measured by Melvern's Zataizer Nano S90 was in the range of 100 nm to 300 nm, and the acid value of each of the silicone resins measured in accordance with JIS K 0070 was in the range of 17.3 mg KOH / g or less.

[0133] (2) Other resins Acrylic resin 1: EMN-325 (manufactured by Nippon Shokubai Co., Ltd., acrylic resin, anionic, Tg = -50°C) Acrylic resin 2: Symac US-480 (manufactured by Toagosei Co., Ltd., acrylic-silicone graft copolymer, anionic, Tg=0℃) Urethane resin: Takelac WS-6021 (Mitsui Chemicals, urethane resin, anionic, Tg=-60℃)

[0134] The dispersed particle size (Z average) of the acrylic resin 1, acrylic resin 2, and urethane resin, as measured by a Zataizer Nano S90 manufactured by Melvern, was all within the range of 100 nm or less.

[0135] 1-2. Water-soluble organic solvents Ethylene glycol Glycerin

[0136] 1-3.Other ingredients Silicone surfactant: KF-351A (Shin-Etsu Chemical Co., Ltd.) Silicone oil: Hi-Softer K-355 (manufactured by Meisei Chemical Industry Co., Ltd.) Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd., surfactant) Proxel GXL (manufactured by Lonza Japan, 1,2-benzisothiazolin-3-one, antifungal agent)

[0137] 2. Preparation of Overcoat Solution <Preparation of overcoat solutions 1 to 20> Overcoat solutions 1 to 15 were prepared by mixing the components to a total of 100 parts by mass as shown in Tables 1 and 2. Note that the units in the tables all indicate "parts by mass."

[0138] The compositions of overcoat solutions 1 to 10 are shown in Table 1, and the compositions of overcoat solutions 11 to 20 are shown in Table 2.

[0139] [Table 1] [Table 2]

[0140] 3. Ink Preparation 3-1. Preparation of pigment dispersion As a pigment dispersant, 13.5 parts by mass of Cab-0-Jet 400 (manufactured by CABOT) was added to 20 parts by mass of ethylene glycol and 48.5 parts by mass of ion-exchanged water. 18.0 parts by mass of Pigment Black 7 was added to this solution as a black pigment and premixed. Then, the mixture was dispersed using a sand grinder filled with 0.5 mm zirconia beads at a volume ratio of 50%, to prepare black pigment dispersion 1 with a pigment solid content of 18.0% by mass.

[0141] 3-2. Preparation of ink <Preparation of Inks 1 to 4> Inks 1 to 4 were prepared by mixing the components as shown in Table 3 to a total of 100 parts by mass. Note that all units in the table are "parts by mass." Note that for pigment dispersions, the units indicate the total parts by mass of the solid content of the pigment dispersion.

[0142] The compositions of inks 1 to 4 are shown in Table 3.

[0143] [Table 3]

[0144] 4. Preparation of Pretreatment Solution A pretreatment liquid was prepared by mixing each component to a total of 100 parts by mass as shown in Table 4. Note that all units in the table are "parts by mass." [Table 4]

[0145] 5. Imaging and Evaluation <Tests 1-23> 5-1.Image formation As an image forming apparatus, a simple printing test machine equipped with a KM1024iMHE head manufactured by Konica Minolta, Inc. was prepared. The ink, overcoat liquid, and pretreatment liquid prepared above were set in the head of the machine.

[0146] (1) Pretreatment First, cotton satin (100% cotton) was prepared as the fabric. A pretreatment liquid having the composition shown in Table 4 was discharged from the head onto the fabric, and the amount of the pretreatment liquid applied was 15 g / m 2 The formula was given so that

[0147] (2) Applying ink Next, an image was formed on the pretreated fabric using the ink prepared above. Specifically, the prepared ink was ejected from the head to form a solid image. The ink was ejected at 540 dpi in the main scan direction and 720 dpi in the sub scan direction. Note that dpi represents the number of ink droplets (dots) per 2.54 cm. The ejection frequency was 22.4 kHz. The amount of ink applied was 15 g / m. 2 It was decided.

[0148] (3) Applying overcoat liquid Before the ink layer formed on the fabric was completely dry, the overcoat liquid shown in Table 5 was ejected from the head and applied wet-on-wet onto the solid image. The image was then dried at 150°C for 3 minutes in a belt conveying dryer to obtain an image-formed product. The amount of the overcoat liquid applied was 15 g / m 2 It was decided.

[0149] 4-2.Evaluation The wet friction fastness, texture and ejection stability of the overcoat liquid of the resulting image-formed product were evaluated by the following methods.

[0150] (1) Wet friction fastness Dry and wet friction fastness was evaluated using a crockmeter (rubbing tester type I) in accordance with JIS L 0849. The fabrics were graded using a staining gray scale based on JIS 0805 and evaluated according to the following indices. ◎ 3.5 level or above ○ Grade 3 or above but below 3.5 △ Grade 2 or above but below Grade 3 × Level 2 or lower

[0151] (2) Texture The texture of the printed fabric was evaluated by touching it with the fingers. The evaluation criteria were as follows: ◎: No change from before printing ○ It is slightly harder than before printing. △ It is harder than before printing, but still to an acceptable level. × Significantly harder

[0152] (3) Injection stability The prepared overcoat liquid was discharged by a line method under discharge conditions of a droplet volume of 13 pL under conditions of 25° C. and 50% RH using a fixed Konica Minolta KM1024iMHE. After it was confirmed that the filled overcoat liquid was being discharged from all 60 nozzles at the start of discharge, the liquid was allowed to be discharged continuously for 60 minutes. After the 60-minute continuous ejection was completed, the number of nozzles that had been able to eject to the end (the number of ejecting nozzles after the 60-minute continuous ejection was completed) was counted. The evaluation criteria were as follows: ◎ After 60 minutes of continuous discharge, the number of discharge nozzles is 60 ○ The number of nozzles after 60 minutes of continuous discharge is between 55 and 60 △ The number of nozzles ejecting after 60 minutes of continuous ejection is 50 or more but less than 55 × The number of nozzles discharged after 60 minutes of continuous discharge is less than 50 In the tests (Tests 20 and 21) in which no overcoat liquid was used, the ejection stability of the ink was evaluated using the same method and criteria as above.

[0153] The evaluation results of tests 1 to 28 are shown in Table 5.

[0154] [Table 5]

[0155] As shown in Table 5, wet rub fastness was poor and texture was impaired in Tests 22 and 23, which used an overcoat liquid containing acrylic resin or urethane resin 1. In addition, ejection performance was poor in Test 24, which used an overcoat liquid containing a silicone surfactant, and Tests 25 to 27, which contained more than 15% by mass of water-dispersible silicone resin.

[0156] In contrast, in Tests 1 to 18, in which an overcoat liquid containing an appropriate amount of water-dispersible silicone resin was used, the wet rub fastness was high, and the feel and ejection properties were also good.

[0157] In particular, it is clear that the use of a silicone resin with a Tg of less than 20°C can further improve wet friction fastness and texture (Comparison of Tests 3, 8, 9, 13, 17, and 18). It is also clear that the wet friction fastness and texture can be further improved by satisfying the requirement of a Tg difference (ΔTg) of 55°C or less (Comparison of Tests 3, 8, 9, 13, 17, and 18). [Industrial Applicability]

[0158] According to the present invention, it is possible to provide an overcoat liquid for textile printing, an ink set, and an image forming method that have high wet rub fastness while maintaining ejection stability and texture.

Claims

1. An overcoat solution for textile printing, comprising: Contains a water-dispersible silicone resin and water, The content of the water-dispersible silicone resin is 0.01% by mass or more and less than 15% by mass with respect to the overcoat liquid for textile printing. Overcoat liquid for textile printing.

2. The water-dispersible silicone resin has a glass transition temperature of less than 20° C. The overcoat liquid for textile printing according to claim 1.

3. The water-dispersible silicone resin is a copolymer containing a structural unit derived from a polyorganosiloxane having a radical polymerizable group, and a structural unit derived from a (meth)acrylic acid ester, vinyl acetate, and a urethane compound having a radical polymerizable group. The overcoat liquid for textile printing according to claim 1.

4. The water-dispersible silicone resin is an anionic silicone resin. The overcoat liquid for textile printing according to claim 1.

5. Further comprising a water-soluble organic solvent, The overcoat liquid for textile printing according to claim 1.

6. an ink-jet ink containing a pigment, a binder resin, water, and a water-soluble organic solvent; The overcoat liquid for textile printing according to any one of claims 1 to 5, Including, Ink set.

7. the water-dispersible silicone resin has a glass transition temperature equal to or higher than the glass transition temperature of the binder resin; The difference between the glass transition temperature of the water-dispersible silicone resin and the glass transition temperature of the binder resin is 55° C. or less. The ink set according to claim 6.

8. applying an inkjet ink containing a pigment, a binder resin, water, and a water-soluble organic solvent onto a fabric by an inkjet method; A step of applying the overcoat liquid for textile printing according to any one of claims 1 to 5 onto the ink-jet ink applied to the fabric; Including, Image forming method.

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