Patent Application
20240125045
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2022-164631, filed on Oct. 13, 2022, the entire contents of which are incorporated by reference herein.
Embodiments of the present invention relate to a method for producing a printed textile item.
Among the various methods for printing images such as text, pictures, or designs onto fabrics such as woven fabrics, knitted fabrics, and nonwoven fabrics, inkjet textile printing methods are now attracting considerable attention.
Compared with an image formed on a light colored fabric such as a white fabric, an image formed on a dark colored fabric such as a black fabric tends to be less visible. JP 2009-30014 A discloses a method in which a pretreatment agent containing a polyvalent metal salt is applied to a dark colored fabric such as a black fabric, then an ink containing a white pigment is applied thereon to form a white image, and a desired image is formed thereon. Further, JP 2009-30014 A discloses that a heat treatment is performed after the pretreatment agent is applied.
An embodiment of the present invention relates to a method for producing a printed textile item including applying a pretreatment liquid to a fabric, and applying a white ink using an inkjet method to the fabric to which the pretreatment liquid has been applied, wherein the pretreatment liquid contains a polyvalent metal salt, a surfactant, and water, the white ink contains a white inorganic pigment, resin particles, a surfactant, and water, an amount of the white inorganic pigment, relative to a total mass of the white ink, is within a range from 5.0 to 15.0% by mass, a total amount of the white inorganic pigment and the resin particles, relative to a total mass of the white ink, is within a range from 20 to 35% by mass, and an amount A (g/m2) of the resin particles of the white ink applied to the fabric and an amount B (g/m2) of the polyvalent metal salt of the pretreatment liquid applied to the fabric satisfy a relationship of A2/B≥50.
Embodiments of the present invention will be described in detail below, but it is needless to say that the present invention is not limited to these embodiments and various modifications and alterations are possible.
Suppose that a pretreatment liquid containing an aggregating agent is applied to a dark colored fabric, and then a white ink is applied to form a white image using what is referred to as a wet-on-wet method without providing a drying step. In the above case, cracking may sometimes occur in the white image after washing.
A method for producing a printed textile item of one embodiment includes applying a pretreatment liquid to a fabric, and applying a white ink using an inkjet method to the fabric to which the pretreatment liquid has been applied, wherein the pretreatment liquid contains a polyvalent metal salt, a surfactant, and water, the white ink contains a white inorganic pigment, resin particles, a surfactant, and water, an amount of the white inorganic pigment, relative to a total mass of the white ink, is within a range from 5.0 to 15.0% by mass, a total amount of the white inorganic pigment and the resin particles, relative to the total mass of the white ink, is within a range from 20 to 35% by mass, and an amount A (g/m2) of the resin particles of the white ink applied to the fabric and an amount B (g/m2) of the polyvalent metal salt of the pretreatment liquid applied to the fabric satisfy a relationship of A2/B≥50.
When this method is used, it is possible to produce a printed textile item in which cracking is less likely to occur in a white image after washing.
In those cases where a white image is formed on a dark colored fabric using a wet-on-wet method, compared to cases using a wet-on-dry method, cracking after washing is more likely to occur.
Although not bound by any specific theory, the mechanism of the occurrence of cracking when a wet-on-wet method is used is speculated to be as follows.
When a wet-on-wet method is used, a white ink in the form of liquid is applied onto a fabric that is still wet with pretreatment liquid, and thus the white ink and the pretreatment liquid may easily mix. For this reason, an ink film may be easily formed in a state in which a polyvalent metal salt, which is a component of the pretreatment liquid, or the like is mixed in the inside of the white ink layer. The polyvalent metal salt mixed in the ink layer may dissolve in water by washing, and may be easily removed from the ink film. When the polyvalent metal salt is removed from the white ink layer, the white ink layer may become fragile due to the generation of gaps, and thus cracking is likely to occur. The mechanism is speculated to be as described above.
Although not bound by any specific theory, it is speculated that a printed textile article in which cracking is less likely to occur in a white image after washing may be produced by a method of producing a printed textile item according to one embodiment, due to the following actions.
When the total amount of the white inorganic pigment and the resin particles of the white ink, relative to the total mass of the white ink, is within a range from 20 to 35% by mass, the solid fraction amount of the white ink tends to be large, and thus the fluidity of the ink after the landing of the ink may tend to decrease, and the white ink and the pretreatment liquid may become relatively less likely to mix together. When the amount A (g/m2) of the resin particles of the white ink applied to the fabric and the amount B (g/m2) of the polyvalent metal salt of the pretreatment liquid applied to the fabric satisfy the relationship of A2/B≥50, and the amount of the white inorganic pigment, relative to the total mass of the white ink, is within a range from 5.0 to 15.0% by mass, the ink film may be reinforced such that the occurrence of cracking may be suppressed after the removal of the polyvalent metal salt from the ink layer by washing. In this manner, it is possible to produce a printed textile item in which cracking is less likely to occur in the white image after washing, even if a wet-on-wet method is used.
The method for producing a printed textile item according to one embodiment includes applying a pretreatment liquid to a fabric, and applying a white ink using an inkjet method to the fabric to which the pretreatment liquid has been applied.
The fabric, the pretreatment liquid, and the white ink will be described below.
The method for producing a printed textile item of one embodiment may be preferably used for printing on a fabric.
Examples of fibers included in the fabric include natural fibers such as cotton, silk, wool, and linen, chemical fibers such as polyester, acrylic, polyurethane, nylon, rayon, cupro, and acetate, and the like. The fabric may contain one type of fiber or a combination of two or more types of fibers. Further, the fabric may be, for example, a woven fabric, a knitted fabric, a nonwoven fabric, or the like.
The pretreatment liquid may contain a polyvalent metal salt as an aggregating agent.
Polyvalent metal salts may be composed of a divalent or higher polyvalent metal ion and an anion. Examples of a divalent or higher polyvalent metal ion include Ca2+, Mg2+, Cu2+, Ni2+, Zn2+, and Ba2+. Examples of an anion include Cl−, NO3−, CH3COO−, I−, Br−, SO42−, and ClO3−. Specific examples of polyvalent metal salts include calcium chloride, calcium nitrate, magnesium nitrate, magnesium sulfate, copper nitrate, calcium acetate, and magnesium acetate. The polyvalent metal salt may be a hydrate or an anhydride.
One of these polyvalent metal salts may be used alone or a combination of two or more may be used.
The amount of the polyvalent metal salt in terms of the active component amount, relative to the total mass of the pretreatment liquid, is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 20% by mass or more. The amount of the polyvalent metal salt in terms of the active component amount, relative to the total mass of the pretreatment liquid, is preferably 40% by mass or less, more preferably 35% by mass or less, and further preferably 30% by mass or less. The amount of the polyvalent metal salt in terms of the active component amount, relative to the total mass of the pretreatment liquid, is preferably within a range from 10 to 40% by mass, more preferably from 15 to 35% by mass, and further preferably from 20 to 30% by mass.
In those cases where a metal salt hydrate is used as the polyvalent metal salt, the amount of active component of the polyvalent metal salt refers to the equivalent amount of the anhydrous salt.
The pretreatment liquid preferably contains a surfactant. Examples of surfactants that may be used include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. One kind may be used, or two or more thereof may be used in combination. Among these surfactants, nonionic surfactants are more preferred. The surfactant may be, for example, a low-molecular weight surfactant or a high-molecular weight surfactant.
The HLB value of the surfactant is preferably within a range from 5 to 20, more preferably from 10 to 18, and further preferably from 14 to 18.
The HLB value is one measure that indicates the properties of a surfactant and is a numerical value of the balance between a hydrophilic group and an oleophilic group in a molecule. The HLB value, which is proposed by means of several calculation methods, is a value calculated by means of the Griffin method in the present specification and is calculated using the following formula (1). The same applies for the HLB value of the surfactant below.
HLB value=20×(formula weight of hydrophilic part)/(molecular weight of surfactant) formula (1)
The “hydrophilic part” indicates a hydrophilic portion contained in the molecular structure of the surfactant, and is preferably a polyoxyalkylene group, an alcohol group in which the main chain carbon number relative to a hydroxyl group is 3 or less, or a combination thereof. If the surfactant contains more than one hydrophilic portion, the formula weight of the hydrophilic part in formula (1) above is the sum of these.
Examples of the polyoxyalkylene group include a polyoxyethylene group (polyethylene oxide; EO: —(CH2CH2O)n—), and a polyoxypropylene group (polypropylene oxide; PO: —(CH2CH2CH2O)n—).
Examples of the alcohol group include a group derived from methanol, a group derived from ethanol, a group derived from propanol, a group derived from isopropanol, a group derived from glycerol, a group derived from polyglycerol, a group derived from trimethylolpropane, a group derived from pentaerythritol, a group derived from sorbitol, a group derived from sorbitan, a group derived from sucrose, a group derived from mannitol, and a group derived from glycol (for example, —CH2CH2OH in the case of ethanol).
A “hydrophobic part” indicates a hydrophobic portion contained in the molecular structure of the surfactant, and is preferably: an aliphatic hydrocarbon group or an aromatic hydrocarbon group in which the main chain carbon number relative to a hydroxyl group is 4 or more and which is a group derived from an aliphatic alcohol, a group derived from an alkylphenol, a group derived from a fatty acid, or the like; a group derived from an organosiloxane, a group derived from an alkyl halide, or the like; or a combination thereof.
Examples of nonionic surfactants include ester-based surfactants such as glycerol fatty acid ester-based surfactants and fatty acid sorbitan ester-based surfactants; ether-based surfactants such as polyoxyethylene alkyl ether-based surfactants, polyoxyethylene alkyl phenyl ether-based surfactants, and polyoxypropylene alkyl ether-based surfactants; ether ester-based surfactants such as polyoxyethylene sorbitan fatty acid ester-based surfactants; acetylene-based surfactants; silicone-based surfactants; and fluorine-based surfactants. Among these, acetylene-based surfactants such as acetylene glycol-based surfactants are preferred.
Examples of the acetylene-based surfactants include acetylene glycol-based surfactants, acetylene alcohol-based surfactants, and surfactants having an acetylene group.
Acetylene glycol-based surfactants are glycols having an acetylene group, are preferably glycols having a left-right symmetrical structure with an acetylene group in the center, and may include a structure in which ethylene oxide has been added to acetylene glycol.
Examples of commercially available products of acetylene-based surfactants include the SURFYNOL series of products such as “SURFYNOL 104E”, “SURFYNOL 104H”, “SURFYNOL 420”, “SURFYNOL 440”, “SURFYNOL 465”, and “SURFYNOL 485” manufactured by Evonik Industries AG, and the OLFINE series of products such as “OLFINE E1004”, “OLFINE E1010”, and “OLFINE E1020” manufactured by Nissin Chemical Industry Co., Ltd. (wherein all of the above are product names).
Examples of the silicone-based surfactants include polyether-modified silicone-based surfactants, alkyl-aralkyl-comodified silicone-based surfactants, and acrylic silicone-based surfactants.
Examples of commercially available products of silicone-based surfactants include “SILFACE SAG002” and “SILFACE SAG503A” manufactured by Nissin Chemical Industry Co., Ltd. (wherein both of the above are product names).
Further examples of other nonionic surfactants include polyoxyethylene alkyl ether-based surfactants such as the EMULGEN series of products including “EMULGEN 102KG”, “EMULGEN 103”, “EMULGEN 104P”, “EMULGEN 105”, “EMULGEN 106”, “EMULGEN 108”, “EMULGEN 120”, “EMULGEN 147”, “EMULGEN 150”, “EMULGEN 220”, “EMULGEN 350”, “EMULGEN 404”, “EMULGEN 420”, “EMULGEN 705”, “EMULGEN 707”, “EMULGEN 709”, “EMULGEN 1108”, “EMULGEN 4085”, and “EMULGEN 2025G” manufactured by Kao Corporation (wherein all of the above are product names).
Examples of the anionic surfactants include the EMAL series of products such as “EMAL 0”, “EMAL 10”, “EMAL 2F”, “EMAL 40”, and “EMAL 20C”, the NEOPELEX series of products such as “NEOPELEX GS”, “NEOPELEX G-15”, “NEOPELEX G-25”, and “NEOPELEX G-65”, the PELEX series of products such as “PELEX OT-P”, “PELEX TR”, “PELEX CS”, “PELEX TA”, “PELEX SS-L”, and “PELEX SS-H”, and the DEMOL series of products such as “DEMOL N”, “DEMOL NL”, “DEMOL RN”, and “DEMOL MS”, all manufactured by Kao Corporation (wherein all of the above are product names).
Examples of the cationic surfactants include the ACETAMIN series of products such as “ACETAMIN 24” and “ACETAMIN 86”, the QUARTAMIN series of products such as “QUARTAMIN 24P”, “QUARTAMIN 86P”, “QUARTAMIN 60W”, and “QUARTAMIN 86W”, and the SANISOL series of products such as “SANISOL C” and “SANISOL B-50”, all manufactured by Kao Corporation (wherein all of the above are product names).
Examples of the amphoteric surfactants include the AMPHITOL series of products such as “AMPHITOL 20BS”, “AMPHITOL 24B”, “AMPHITOL 86B”, “AMPHITOL 20YB”, and “AMPHITOL 20N” manufactured by Kao Corporation (wherein all of the above are product names).
A single surfactant may be used alone, but a combination of two or more surfactants may also be used.
The amount of the surfactant, in terms of the active component amount, relative to the total mass of the pretreatment liquid is preferably within a range from 0.01 to 10% by mass, more preferably from 0.1 to 5% by mass, and further preferably from 0.2 to 3% by mass.
The pretreatment liquid may contain water.
There are no particular limitations on the water but water containing as few ionic components as possible is preferred. Examples of the water include ion-exchanged water, distilled water, and ultrapure water.
The amount of water relative to the total mass of the pretreatment liquid is preferably within a range from 20 to 90% by mass, more preferably from 30 to 70% by mass, and further preferably from 40 to 60% by mass.
The pretreatment liquid may contain one or more other components if necessary. Examples of these other components include water-soluble organic solvents, antifoaming agents, pH adjusters, antioxidants, and preservatives.
The pretreatment liquid preferably contains a water-soluble organic solvent. An organic compound that is liquid at room temperature and can be dissolved in water can be used as the water-soluble organic solvent. The use of a water-soluble organic solvent that mixes uniformly with an equal volume of water at 1 atmosphere and 20° C. is preferred. Examples of water-soluble organic solvents that may be used include lower alcohols such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, and 2-methyl-2-propanol; glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and polypropylene glycol; glycerols such as glycerol, diglycerol, triglycerol, and polyglycerol; acetins such as monoacetin and diacetin; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol dimethyl ether, and tetraethylene glycol diethyl ether; and triethanolamine, 1-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 0-thiodiglycol, and sulfolane. The boiling point of the water-soluble organic solvent is preferably 100° C. or higher, and more preferably 150° C. or higher.
One of these water-soluble organic solvents may be used alone, or a combination of two or more water-soluble organic solvents may be used provided the solvents form a single phase with water. The amount of the water-soluble organic solvent relative to the total mass of the pretreatment liquid is preferably within a range from 5 to 50% by mass, and more preferably from 10 to 35% by mass.
There are no particular limitations on the method used for producing the pretreatment liquid, and production may be performed using appropriate conventional methods. For example, the pretreatment liquid may be obtained using a stirring device such as a three-one motor to disperse all of the components, either in a single batch or in a number of separate batches, and then passing the dispersion through a filtration device such as a membrane filter if desired.
The pH of the pretreatment liquid is preferably within a range from 3 to 9 and more preferably from 4 to 8.
The viscosity of the pretreatment liquid at 23° C. is preferably within a range from 1 to 30 mPa·s.
The pretreatment liquid can be preferably used for textile printing. The method of applying the pretreatment liquid is not particularly limited, but it is preferable to apply the pretreatment liquid using an inkjet method.
The white ink may contain a white inorganic pigment as a colorant.
Examples of the white inorganic pigment include titanium oxide, zinc oxide, zinc sulfide, antimony oxide, and zirconium oxide. Among these, from the viewpoint of the concealment properties, the use of titanium oxide is preferred. The average particle size of the titanium oxide is preferably 100 nm or more from the viewpoint of the concealment properties, and is preferably 600 nm or less from the viewpoint of the jetting stability. In those cases where titanium oxide is used, in order to suppress any photocatalytic action, the use of titanium oxide that has been surface treated with alumina or silica is preferred. The surface treatment amount is preferably within a range from 5 to 20% by mass of the pigment.
A self-dispersing pigment may be used as the white inorganic pigment. A self-dispersing pigment is a pigment in which a hydrophilic functional group has been introduced to the pigment surface by a chemical treatment or a physical treatment. The hydrophilic functional group introduced into the self-dispersing pigment is preferably a group that has ionicity. By charging the pigment surface either anionically or cationically, the pigment particles can be stably dispersed in water by means of electrostatic repulsion. Examples of preferable anionic functional groups include carboxyl groups, sulfo groups, sulfino groups, sulfuric acid ester groups, phosphoric acid groups, phosphoric acid ester groups, phosphorous acid groups, and phosphorous acid ester groups. Examples of preferable cationic functional groups include quaternary ammonium groups and quaternary phosphonium groups. These hydrophilic functional groups may be bonded directly to the pigment surface, or may be bonded via another atom grouping. Examples of this other atom grouping include, but are not limited to, alkylene groups, phenylene groups, and naphthylene groups. Examples of methods for treating the pigment surface include diazotization treatments, sulfonation treatments, hypochlorous acid treatments, humic acid treatments, and vacuum plasma treatments.
As the white inorganic pigment, a pigment dispersion containing a pigment that has already been dispersed using a pigment dispersant may also be used. A pigment dispersion containing a pigment that has been dispersed using a pigment dispersant described later may be used.
One white inorganic pigment may be used alone or a combination of two or more white inorganic pigments may be used.
From the viewpoint of the ink film strength, the amount of the white inorganic pigment, relative to the total mass of the white ink, is preferably 5.0% by mass or more, more preferably 5.5% by mass or more, and further preferably 6.0% by mass or more. From the viewpoint of the ink film strength, the amount of the white inorganic pigment, relative to the total mass of the white ink, is preferably 15.0% by mass or less, more preferably 13.0% by mass or less, further preferably 11.0% by mass or less, and even further preferably 9.0% by mass or less. The amount of the white inorganic pigment, relative to the total mass of the white ink, is preferably within a range from 5.0 to 15.0% by mass, more preferably from 5.0 to 13.0% by mass, further preferably from 5.5 to 11.0% by mass, and even further preferably from 6.0 to 9.0% by mass.
In order to disperse the white inorganic pigment stably in the white ink, a pigment dispersant typified by polymer dispersants and surfactant-type dispersants can be used.
Examples of commercially available products of polymer dispersants include the TEGO Dispers series of products such as “TEGO Dispers 740W”, “TEGO Dispers 750W”, “TEGO Dispers 755W”, “TEGO Dispers 757W”, and “TEGO Dispers 760W” manufactured by Evonik Industries AG, the Solsperse series of products such as “Solsperse 20000”, “Solsperse 27000”, “Solsperse 41000”, “Solsperse 41090”, “Solsperse 43000”, “Solsperse 44000”, and “Solsperse 46000” manufactured by The Lubrizol Corporation, the Joncryl series of products such as “Joncryl 57”, “Joncryl 60”, “Joncryl 62”, “Joncryl 63”, “Joncryl 71”, and “Joncryl 501” manufactured by BASF Japan Ltd., “DISPERBYK-102”, “DISPERBYK-185”, “DISPERBYK-190”, “DISPERBYK-193”, and “DISPERBYK-199” manufactured by BYK-Chemie Japan K.K., and “Polyvinylpyrrolidone K-30” and “Polyvinylpyrrolidone K-90” manufactured by DKS Co., Ltd. (wherein all of the above are product names).
Examples of the surfactant-type dispersants include anionic surfactants, including the DEMOL series of products such as “DEMOL P”, “DEMOL EP”, “DEMOL N”, “DEMOL RN”, “DEMOL NL”, “DEMOL RNL”, and “DEMOL T-45” manufactured by Kao Corporation, and nonionic surfactants including the EMULGEN series of products such as “EMULGEN A-60”, “EMULGEN A-90”, “EMULGEN A-500”, “EMULGEN B-40”, “EMULGEN L-40”, and “EMULGEN 420” manufactured by Kao Corporation (wherein all of the above are product names).
One pigment dispersant may be used alone or a combination of two or more pigment dispersants may be used.
When used, there are no particular limitations on the amount of the pigment dispersant in the white ink, which may vary depending on the type of pigment dispersant used, but generally the amount of the pigment dispersant, expressed as a mass ratio of the active component relative to a value of 1 for the pigment, is preferably within a range from 0.005 to 0.5.
The white ink may contain resin particles.
It is preferable that the resin particles can be dispersed in an aqueous solvent. It is preferable that the resin particles can be dispersed in water without being dissolved in the water and can form an oil-in-water (O/W) type emulsion.
The resin particles can be blended as an oil-in-water resin emulsion in the production of the white ink.
The resin particles may be self-emulsifying resin particles in which hydrophilic groups and/or hydrophilic segments are introduced in the resin for stable dispersion in water, or forced emulsifying resin particles in which the resin is forcibly dispersed by using a dispersant.
The resin particles may be anionic, cationic, nonionic, or amphoteric, for example, but are preferably anionic or nonionic.
The anionic resin particles may be a resin in which anionic functional groups of the resin are located on the resin particle surfaces, as in the case of a self-emulsifying resin, or may be a resin that has been subjected to a surface treatment by, for example, adhering an anionic dispersant to the resin particle surfaces. Examples of typical anionic functional groups include carboxyl groups, sulfo groups, sulfino groups, sulfuric acid ester groups, phosphoric acid groups, phosphoric acid ester groups, phosphorous acid groups, phosphorous and acid ester groups. Examples of anionic dispersants include anion surfactants.
The nonionic resin particles may be resin particles in which nonionic functional groups of the resin are located on the resin particle surfaces, as in the case of a self-emulsifying resin, or may be resin particles that have been subjected to a surface treatment by, for example, adhering a nonionic dispersant to the resin particle surfaces. Examples of typical nonionic functional groups include polyoxyalkylene glycol groups and hydroxyl groups. Examples of the nonionic dispersant include nonionic surfactants and the like.
The average particle size of the resin particles is preferably 600 nm or less, more preferably 500 nm or less, and further preferably 400 nm or less from the viewpoint of the inkjet jetting characteristics. The average particle size of the resin particles may be in the range from 10 nm to 600 nm, and may be in the range from 50 nm to 500 nm, for example. From the viewpoint of inkjet jetting characteristics, resin particles having an average particle size of 100 nm or more are preferably contained. The amount of the resin particles having an average particle size of 100 nm or more, relative to the total mass of the resin particles in the ink, is preferably 20% by mass or more, and more preferably 50% by mass or more. The higher the ratio of the resin particles having an average particle size of 100 nm or more relative to the total mass of the resin particles, the less likely it is that structural viscosity occurs, and thus, the less likely it is that ejection failure occurs.
In the present specification, the average particle size of the resin particles is a median diameter on a volume basis in a particle size distribution measured by means of a dynamic light scattering method. With the use of the measurement sample obtained by diluting the resin emulsion with water so as to achieve a 0.5% by mass resin particle concentration of the sample, the particle size distribution can be measured at 25° C. As the particle size distribution measurement device of dynamic light scattering type, for example, “Nano Particle Analyzer nano Partica SZ-100 (manufactured by HORIBA, Ltd.) can be used.
The average particle size of the resin particles can be measured in the state of the raw material resin emulsion before the production of the ink, which is preferable from the viewpoint of eliminating the effects by the colorant, and the value obtained in such a manner can be used as the average particle size of the resin particles.
Examples of the resin of the resin particles include: conjugated diene-based resins such as styrene-butadiene copolymers, methyl methacrylate-butadiene copolymers, and vinyl chloride-vinyl acetate copolymers; acrylic-based resins such as acrylic acid ester polymers, methacrylic acid ester polymers, and copolymers of any one or more selected from the group consisting of acrylic acid esters and methacrylic acid esters with styrene or the like; vinyl-based resins such as ethylene-vinyl acetate copolymers; functional group-modified resins in which any of these resins has been modified with a monomer containing a functional group such as a carboxyl group; melamine resins; urea resins; polyurethane resins; polyester resins; polyolefin resins; silicone resins; polyvinyl butyral resins; and alkyd resins. Resin particles containing one of these resins may be used but hybrid resin particles may also be used.
The resin particles preferably contain acrylic-based resin particles, polyurethane resin particles, or a combination thereof.
A polyurethane resin may be either an aliphatic polyurethane resin or an aromatic polyurethane resin. The polyurethane resin has a urethane skeleton. Examples of polyurethane resins include polyether-based polyurethane resins having an ether bond in the main chain in addition to the urethane skeleton, polyester-based polyurethane resins having an ester bond in the main chain in addition to the urethane skeleton, carbonate-based polyurethane having a carbonate bond in the main chain in addition to the urethane skeleton, and ester/ether-based polyurethane resins having an ester bond and an ether bond in the main chain in addition to the urethane skeleton.
The resin particles preferably contain polyurethane resin. From the viewpoint of superior adhesiveness to a wide variety of fabrics, the resin particles preferably contain a polyester-based urethane resin.
The amount of the polyester-based urethane resin particles relative to the total mass of the resin particles is preferably 10% by mass or more, more preferably 30% by mass or more, and further preferably 50% by mass or more. The amount of the polyester-based resin particles relative to the total mass of the resin particles may be, for example, 100% by mass or less, or 95% by mass or less.
Examples of commercially available products of emulsions of resin particles include the IMPRANIL series products, such as “IMPRANIL DLP-R”, “IMPRANIL DLU”, and “IMPRANIL DLF” manufactured by Sumika Covestro Urethane Co., Ltd., the SUPERFLEX series products such as “SUPERFLEX 300”, “SUPERFLEX 420”, “SUPERFLEX 460”, “SUPERFLEX 470”, “SUPERFLEX 500M”, “SUPERFLEX 740”, “SUPERFLEX150HS”, and “SUPERFLEX E2000” manufactured by DKS Co., Ltd., the DAOTAN series products such as “DOTAN TW6490/35WA”, “DOTAN TW6492/35WA”, “DOTAN TW6493/35WA”, “DOTAN TW6450/35WA”, and “DOTAN VTW6463/36WA” manufactured by DAICEL-ALLNEX LTD., the TAKELAC series products of “TAKELAC W-6061”, and “TAKELAC W-6010”, and “UW-1701F” and “UW-1005D-C1” manufactured by UBE Corporation (wherein all of the above are product names).
One type of resin particles may be used, or a combination of two or more types of resin particles may be used.
The amount of resin particles relative to the total mass of the white ink is preferably 12% by mass or more, more preferably 15% by mass or more, further preferably 18% by mass or more, and further preferably 21% by mass or more. The amount of the resin particles relative to the total mass of the white ink is preferably 32% by mass or less, more preferably 30% by mass or less, further preferably 28% by mass or less, and even further preferably 26% by mass or less. The amount of resin particles relative to the total mass of the white ink is preferably within a range from 12 to 32% by mass, more preferably from 15 to 30% by mass, further preferably from 18 to 28% by mass, and even further preferably from 21 to 26% by mass.
From the viewpoints of making it difficult for the white ink and the pretreatment liquid to mix and reducing the occurrence of cracking in the white image after washing, the total amount of the white inorganic pigment and the resin particles, relative to the total mass of the white ink, is preferably 20% by mass or more, more preferably 25% by mass or more, further preferably 28% by mass or more, and even further preferably 30% by mass or more. The total amount of the white inorganic pigment and the resin particles, relative to the total mass of the white ink, is preferably 35% by mass or less, and more preferably 32% by mass or less. The total amount of the white inorganic pigment and the resin particles, relative to the total mass of the white ink, is, for example, preferably within a range from 20 to 35% by mass, more preferably from 25 to 35% by mass, further preferably from 28 to 32% by mass, and even further preferably from 30 to 32% by mass.
From the viewpoint of further enhancing the ink film strength, the mass ratio of the resin particles relative to the white inorganic pigment, “resin particles/white inorganic pigment”, in the white ink, is preferably 1.2 or more, more preferably 1.5 or more, further preferably 2.0 or more, and even further preferably 2.5 or more. The mass ratio of the resin particles relative to the white inorganic pigment, “resin particles/white inorganic pigment”, in the white ink, may be, for example, 5.0 or less, 4.5 or less, or 4.0 or less. The mass ratio of the resin particles relative to the white inorganic pigment, “resin particles/white inorganic pigment”, in the white ink, is, for example, preferably within a range from 1.2 to 5.0, more preferably from 1.5 to 4.5, and further preferably 2.0 to 4.0, and may be, for example, 2.5 to 4.0.
The white ink may contain a surfactant.
Examples of surfactants that may be used preferably include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. One kind thereof may be used, or two or more thereof may be used in combination. Among these surfactants, nonionic surfactants are more preferred. The surfactant may be, for example, a low-molecular weight surfactant or a high-molecular weight surfactant.
The HLB value of the surfactant is preferably within a range from 5 to 20, more preferably from 10 to 18, and further preferably from 10 to 15.
From the viewpoints of making it difficult for the white ink and the pretreatment liquid to mix, a surfactant having an HLB value lower than that of the surfactant contained in the pretreatment liquid may be contained in the white ink. For example, the HLB value of the surfactant contained in the white ink may be lower than 15 and the HLB value of the surfactant contained in the treatment liquid may be 15 or higher.
Examples of the surfactant that may be used include those described above in relation to the pretreatment liquid, and the surfactant may be selected from among those described above in relation to the pretreatment liquid. Among these, acetylene-based surfactants such as acetylene glycol-based surfactants can be used particularly favorably.
The amount of the surfactant, in terms of the active component amount, relative to the total mass of the white ink is preferably within a range from 0.01 to 10% by mass, more preferably from 0.1 to 5% by mass, and further preferably from 0.2 to 3% by mass.
The white ink may contain water. There are no particular limitations on the water, but water containing as few ionic components as possible is preferred. In particular, from the viewpoint of the ink storage stability, the amount of polyvalent metal ions such as calcium ions is preferably kept low. Examples of the water include ion-exchanged water, distilled water, and ultrapure water.
From the viewpoint of adjustment of the ink viscosity, the amount of water relative to the total mass of white ink is preferably within a range from 30 to 70% by mass, more preferably from 35 to 65% by mass, and further preferably from 40 to 60% by mass.
The white ink may contain one or more other components if necessary. Examples of these other components include water-soluble organic solvents, antifoaming agents, antioxidants, pH adjusters, and preservatives.
The white ink preferably contains a water-soluble organic solvent. Organic compounds that are liquid at room temperature and can be dissolved in water can be used as the water-soluble organic solvent, and the use of a water-soluble organic solvent that mixes uniformly with an equal volume of water at 1 atmosphere and 20° C. is preferred. The boiling point of the water-soluble organic solvent is preferably 100° C. or higher, more preferably 150° C. or higher, further preferably 200° C. or higher, and even further preferably 250° C. or higher.
Examples of the water-soluble organic solvent that may be used include those described above in relation to the pretreatment liquid, and the water-soluble organic solvent may be selected from among those described above in relation to the pretreatment liquid.
One water-soluble organic solvent may be used alone, or a combination of two or more water-soluble organic solvents may be used provided that the solvents form a single phase with water. The amount of the water-soluble organic solvent relative to the total mass of white ink is preferably within a range from 5 to 50% by mass, more preferably from 5 to 40% by mass, and more preferably from 10 to 30% by mass.
From the viewpoint of the stability in the printer, the amount of the water-soluble organic solvent, expressed as a mass ratio of the amount of thereof relative to a value of 1 for the pigment, is preferably 0.2 or more, more preferably 0.5 or more, further preferably 0.7 or more, and even further preferably 0.9 or more.
There are no particular limitations on the method used for producing the white ink, and production may be performed using appropriate conventional methods. For example, the ink may be obtained by using a stirring device such as a three-one motor to disperse all of the components, either in a single batch or in a number of separate batches, and then passing the resulting dispersion through a filtration device such as a membrane filter if desired.
The pH of white ink is preferably within a range from 7.0 to 10.0 and more preferably from 7.5 to 9.0 from the viewpoint of the ink storage stability.
The viscosity of the white ink at 23° C. is preferably within a range from 1 to 30 mPa·s from the viewpoint of the inkjet jetting characteristics, for example.
The white ink may be preferably used for textile printing.
The white ink may be applied to a fabric using an inkjet method to form a white image. A color ink may be applied to a fabric to which the white ink has been applied to form a non-white image. The white ink is preferably applied to a substrate to which a pretreatment liquid has been applied.
A method for producing a printed textile item of one embodiment may include applying the pretreatment liquid as described above to a fabric (hereinafter also referred to as a “pretreatment liquid application step”), and applying the white ink as described above using an inkjet method to the fabric to which the pretreatment liquid has been applied (hereinafter also referred to as a “white ink application step”). As the fabric, it is possible to use the fabric as described above.
The pretreatment liquid application step will be described.
The method for applying a pretreatment liquid to a fabric is not particularly limited, and any method such as a spray method using an airbrush or the like, a dipping method, a pad method, a coating method, or the like can be used, for example. In addition, it is possible to use various printing methods such as inkjet printing (an inkjet method) and screen printing.
There are no particular limitations on the inkjet method, and any one of a piezo method, electrostatic method, and thermal method may be used. When an inkjet printing device is used, liquid droplets of the pretreatment liquid or ink are preferably jetted from the inkjet head based on a digital signal so that the jetted ink droplets are adhered to the fabric.
The region of the fabric to which the pretreatment liquid is applied may be a region of the same shape as the image that is to be formed by using the white ink, may be a broader region that incorporates the shape of the image to be formed by using the white ink, or may be the entire surface of the fabric, for example.
The application region for the pretreatment liquid, the application region for the white ink, and the application region for a color ink preferably overlap at least partially.
The amount of the pretreatment liquid applied to the fabric is preferably within a range from 5 to 300 g/m2, more preferably from 10 to 250 g/m2, and further preferably from 15 to 200 g/m2. The amount of the pretreatment liquid may vary depending on the type of the fabric.
From the viewpoint of enhancing the ink film strength, the amount A (g/m2) of the resin particles of the white ink applied to the fabric per unit area, and the amount B (g/m2) of the polyvalent metal salt of the pretreatment liquid applied to the fabric per unit area preferably satisfy the relationship of A2/B≥50.
The value A2/B is preferably 60 or more, more preferably 80 or more, further preferably 100 or more, and even further preferably 150 or more. The value A2/B is preferably 3000 or less, 2000 or less, 1000 or less, or 450 or less. The value A2/B is preferably within a range from 50 to 3000, more preferably from 60 to 2000, further preferably from 80 to 1000, even further preferably from 100 to 450, and still further preferably from 150 to 450. When the value A2/B is 3000 or less, favorable color development of the color ink is possible when disposing a color ink on the white ink.
The amount of the pretreatment liquid applied to the fabric is preferably such an amount that the application amount of the polyvalent metal salt of the pretreatment liquid is 1 g/m2 or more, more preferably 3 g/m2 or more, and further preferably 6 g/m2 or more. The amount of the pretreatment liquid applied to the fabric is preferably such an amount that the application amount of the polyvalent metal salt of the pretreatment liquid is 50 g/m2 or less, more preferably 45 g/m2 or less, and further preferably 40 g/m2 or less. The amount of the pretreatment liquid applied to the fabric is preferably such an amount that the application amount of the polyvalent metal salt of the pretreatment liquid is within a range from 1 to 50 g/m2, more preferably from 3 to 45 g/m2, and further preferably from 6 to 40 g/m2.
The amount of the polyvalent metal salt of the pretreatment liquid applied to the fabric may vary depending of the type of the fabric.
The white ink application step will be described.
The white ink is preferably applied to the fabric using an inkjet method. There are no particular limitations on the inkjet method, and any one of a piezo method, electrostatic method, and thermal method may be used. When an inkjet printing device is used, liquid droplets of the pretreatment liquid or ink are preferably jetted from the inkjet head based on a digital signal so that the jetted ink droplets are adhered to the fabric.
In those cases in which the pretreatment liquid is applied using an inkjet method, the application of the pretreatment liquid and the application of the white ink may be performed using different printing devices or using one printing device.
It is preferable that the white ink be applied such that the application region for the pretreatment liquid and the application region for the white ink overlap at least partially. It is preferable that the application region for the pretreatment liquid and the application region for the white ink overlap at least partially.
The white ink is preferably applied, using a wet-on-wet method, to the fabric to which the pretreatment liquid has been applied. The white ink is preferably applied in a state where the moisture has not been completely removed from the fabric to which the pretreatment liquid has been applied. It is preferable that the white ink can be applied while the fabric to which the pretreatment liquid has been applied is maintained in a wet state. Following the application of the pretreatment liquid to the fabric, the white ink is preferably applied to the fabric without first performing a drying step such as heat drying, for example. The temperature of the fabric surface following application of the pretreatment liquid and up until the application of the white ink is preferably 40° C. or lower, and more preferably 35° C. or lower. Following application of the pretreatment liquid, it is preferable that the white ink be applied in a state where the residual amount of the volatile fraction of the pretreatment liquid on the fabric is still 90% by or more. The time period from the application of the pretreatment liquid to the fabric until the application of the white ink is preferably within a range from 0.1 to 200 seconds.
The amount of the white ink applied to the fabric is not particularly limited, but for example is preferably within a range from 50 to 500 g/m2 and more preferably from 100 to 400 g/m2.
The amount of the white ink applied to the fabric is preferably such an amount that the application amount of the resin particles of the white ink is 10 g/m2 or more, more preferably 20 g/m2 or more, and further preferably 35 g/m2 or more. The amount of the white ink applied to the fabric is preferably such an amount that the application amount of the resin particles of the white ink is 200 g/m2 or less, more preferably 150 g/m2 or less, and further preferably 100 g/m2 or less. The amount of the white ink applied to the fabric is preferably such an amount that the application amount of the resin particles of the white ink is within a range from 10 to 200 g/m2, more preferably from 20 to 150 g/m2, and further preferably from 35 to 100 g/m2.
It is preferable to provide a step of subjecting the fabric to a heat treatment after the white ink application step.
The heat treatment temperature may be selected as appropriate in accordance with the material of the fabric and the like. The heat treatment temperature is preferably 100° C. or higher, and more preferably 120° C. or higher, for example. From the viewpoint of reducing any damage to the fabric, the heat treatment temperature is preferably 200° C. or lower.
There are no particular limitations on the heating device, and for example, a heat press, roll heater, hot air device, infrared lamp heater, or the like may be used.
The heat treatment time may be set as appropriate in accordance with the heating method and the like, and is preferably within a range from 1 second to 10 minutes, more preferably from 5 minutes to 5 seconds, and may be, for example, from 30 seconds to 3 minutes.
The method for producing a printed textile item may further include a step of applying a color ink (hereinafter also referred to as a “color ink application step”).
Examples of the color ink include inks other than white ink, such as magenta ink, cyan ink, yellow ink, and black ink.
The color ink can contain a non-white colorant as a colorant. The color ink may contain, for example, a pigment, a dye, or a combination thereof as the non-white colorant. The color ink preferably contains water. The color ink may contain one or more selected from among resin particles, surfactants, and water-soluble organic solvents, as appropriate.
The color ink is preferably applied to the fabric using an inkjet method. The color ink may be preferably applied to the fabric to which the white ink has been applied, by a wet-on-wet method. Alternatively, the color ink may be applied to the fabric to which the white ink has been applied, after drying.
After the color ink application step, a step of subjecting the fabric to a heat treatment may be provided. After the color ink application step, a post-treatment liquid application step may also be provided. For example, the step of subjecting a fabric to a heat treatment may be provided after the color ink application step, and thereafter, the post-treatment liquid may be applied. After the application of the post-treatment liquid, the fabric may be subjected to a heat treatment.
The present disclosure includes the following embodiments.
<1> A method for producing a printed textile item comprising:
<2> The method for producing a printed textile item according to <1>, wherein, in the white ink, a mass ratio of the resin particles relative to the white inorganic pigment is 2.5 or more.
<3> The method for producing a printed textile item according to <1> or <2>, wherein the white ink contains a polyester-based polyurethane resin in the resin particles.
<4> The method for producing a printed textile item according to <1> or <2>, wherein the white ink contains a polyester-based polyurethane resin in an amount of 50% by mass or more relative to the total mass of the resin particles.
<5> The method for producing a printed textile item according to any one of <1> to <4>, wherein the amount A (g/m2) of the resin particles of the white ink applied to the fabric and the amount B (g/m2) of the polyvalent metal salt of the pretreatment liquid applied to the fabric satisfy a relationship of A2/B≥80.
<6> The method for producing a printed textile item according to any one of <1> to <4>, wherein the amount A (g/m2) of the resin particles of the white ink applied to the fabric and the amount B (g/m2) of the polyvalent metal salt of the pretreatment liquid applied to the fabric satisfy a relationship of A2/B≥100.
Embodiments of the present invention will be described below in further detail by using examples. The present invention is not limited to the examples below. In the following descriptions, “%” represents “% by mass” unless specifically stated otherwise.
Table 1 shows formulations of pretreatment liquids. The raw materials were mixed at the blending ratio shown in Table 1, and the obtained mixtures were filtered by using a cellulose acetate membrane filter having a pore size of 3 μm. Accordingly, pretreatment liquids UC1 and UC2 were obtained.
Details of the raw materials shown in Table 1 are as follows. The pretreatment liquids UC1 and UC2 each contain a polyvalent metal salt in an amount of 25% by mass, in terms of the active component amount.
First, 250 g of titanium oxide “R62N” (manufactured by Sakai Chemical Industry Co., Ltd.) as a white pigment and 10 g (active component: 2.5 g) of “DEMOL EP” (manufactured by Kao Corporation) as a pigment dispersant were mixed with 740 g of ion-exchanged water, and a beads mill (DYNO-MILL KDL model A, manufactured by Shinmaru Enterprises Corporation) containing 0.5 mme zirconia beads at a fill ratio of 80% was used to disperse the mixture under conditions including a retention time of 2 minutes, thus obtaining a white pigment dispersion (pigment fraction: 25% by mass).
Tables 2 and 3 show the formulations of white inks W1 to W10. The raw materials were mixed at the blending ratios shown in the tables, and the obtained mixtures were filtered by using a cellulose acetate membrane filter having a pore size of 3 μm. Accordingly, the white inks W1 to W10 were obtained.
Details of the raw materials of the white inks W1 to W10 shown in Tables 2 and 3 are as follows.
The average particle size of each of the resin emulsions is a median diameter on a volume basis measured at a temperature of 25° C. under settings including a dispersion medium refractive index of 1.333 and a sample refractive index of 1.600 and with the operational conditions set to “polydispersion” and “narrow”, using a particle size distribution measurement device of a dynamic light scattering type, “Nano Particle Analyzer nano Partica SZ-100 (manufactured by HORIBA, Ltd.), and using a measurement sample obtained by diluting the resin emulsion with purified water so as to achieve a 0.5% by mass resin particle concentration of the sample.
Printed textile items of Examples 1 to 9 and Comparative Examples 1 to 7 were produced based on the following procedure using the pretreatment liquids UC1 and UC2 and white inks W1 to W10 which were produced as described above.
Tables 4 to 7 show the pretreatment liquids and the application amounts thereof and the white inks and the application amounts thereof used for producing the printed textile items of Examples 1 to 9 and Comparative Examples 1 to 7.
A black cotton T-shirt (product name: Printstar) manufactured by Toms Co., Ltd. was used, and the pretreatment liquid was applied to a 10 cm×20 cm portion of the surface of the black cotton T-shirt using an inkjet method so as to achieve the application amount as shown in the tables. After the pretreatment liquid was applied, the white ink was applied using an inkjet method to the portion where the pretreatment liquid was applied, without providing a drying step, so as to achieve the application amount as shown in the tables. The image was a solid image. An “MMP-8130” (product name) manufactured by Mastermind Inc. was used as a printing device for all of the application of the pretreatment liquid and the application of the white ink. After the application of the white ink, heat drying was performed at 160° C. for 2 minutes using a heat press machine manufactured by Fusion. Accordingly, a printed textile item having a 10 cm×20 cm solid image was obtained.
4. Evaluation of Cracking after Washing
The thus obtained printed textile items were washed in accordance with the standard of AATCC 61 2A, and thereafter, cracking in the image portion was evaluated according to the following criteria. The evaluation results are shown in the tables 4 to 7.
In the printed textile items of Examples 1 to 9, the occurrence of cracking was suppressed.
Meanwhile, in Comparative Examples 1 to 5, in which the amount A (g/m2) of the resin particles of the white ink applied to the fabric and the amount B (g/m2) of the polyvalent metal salt of the pretreatment liquid applied to the fabric do not satisfy the relationship of A2/B≥50, Comparative Example 6, in which the white ink 8 contains a white inorganic pigment in a relatively large amount, and Comparative Example 7, in which the white ink 7 has a relatively small total amount of the white inorganic pigment and the resin particles relative to the total mass of the white ink, much cracking was observed after washing, which is a problematic level in actual practical use. In Comparative Examples 1 to 3 and 5, in addition to the fact that the relationship of A2/B≥50 was not satisfied, in the white ink, the total amount of the resin particles and the white inorganic pigment was relatively small.
It is to be noted that, besides those already mentioned above, many modifications and variations of the above embodiments may be made without departing from the novel and advantageous features of the present invention. Accordingly, all such modifications and variations are intended to be included within the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-164631 | Oct 2022 | JP | national |
