Polyurethane Dispersion

Abstract

To provide a polyurethane dispersion which is excellent in all of color development property, adhesion, shrinkage resistance, feeling and washing fastness, when a fabric is printed.SOLUTION: A polyurethane dispersion is obtained by water dispersion of a polyurethane resin. The polyurethane resin is a reaction product of an isocyanate group-terminated prepolymer, and a chain extender. The isocyanate group-terminated prepolymer is a reaction product of a polyisocyanate component, and a polyol component containing macropolyol, an anionic group-containing active hydrogen compound and polyoxyethylene-containing monool. The acid value of the polyurethane resin is 4.0 mgKOH / g or more and 10.0 mgKOH / g or less. The content of the polyoxyethylene of the polyoxyethylene-containing monool in the polyurethane resin is 2.5 mass% or more and 7.5 mass% or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a polyurethane dispersion. [Background technology]

[0002] It is known that ink jet printing is performed on fabric by ejecting droplets of an ink composition from a nozzle using an ink jet method. The ink composition contains, for example, a colorant and a resin in which the colorant is dispersed.

[0003] As such a resin, for example, an aqueous polyurethane resin dispersion has been proposed, which contains water and a polyurethane resin obtained by reacting a polyol component with a polyisocyanate component, in which the polyurethane resin has carboxyl groups and / or carboxylate anion groups and ethylene oxide units in its side chains, and in which the content of ethylene oxide units in the side chains in the polyurethane resin and the content of constituent units of carboxyl groups and / or carboxylate anion groups in the polyurethane resin are in a predetermined ratio (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-165353 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, when printing fabrics (especially synthetic fibers), the fabrics may be pretreated in order to improve the interaction between the fabric and the ink composition.

[0006] If the fabric is pretreated, the ink composition aggregates on the surface of the fabric due to the interaction between the fabric and the ink composition, thereby suppressing penetration of the ink composition into the fabric. This increases the color density on the surface of the fabric (improves color development). On the other hand, if penetration of the ink composition into the fabric is suppressed, the adhesion between the fabric and the ink composition decreases. In other words, color development and adhesion are in a trade-off relationship.

[0007] Furthermore, in the printing of fabrics (especially synthetic fibers), in addition to color development and adhesion, shrinkage resistance, texture, and washing fastness are required.

[0008] However, the polyurethane dispersion (aqueous polyurethane resin dispersion) described in Patent Document 1 has the drawback of not being able to satisfy all of the requirements for color development, adhesion, shrinkage resistance, texture, and washing fastness.

[0009] The present invention provides a polyurethane dispersion that is excellent in all of color development, adhesion, shrinkage resistance, texture, and washing fastness. [Means for solving the problem]

[0010] The present invention [1] is a polyurethane dispersion in which a polyurethane resin is dispersed in water, the polyurethane resin being a reaction product of an isocyanate-terminated prepolymer and a chain extender, the isocyanate-terminated prepolymer being a reaction product of a polyisocyanate component and a polyol component containing a macropolyol, an anionic group-containing active hydrogen compound, and a polyoxyethylene-containing monool, the acid value of the polyurethane resin being 4.0 mgKOH / g or more and 10.0 mgKOH / g or less, and the polyoxyethylene content of the polyoxyethylene-containing monool in the polyurethane resin being 2.5 mass% or more and 7.5 mass% or less.

[0011] The present invention [2] includes the polyurethane dispersion according to the above [1], in which the elongation at break of the dried product of the polyurethane dispersion is 550% or more and 1200% or less.

[0012] The present invention [3] includes the polyurethane dispersion according to the above [1] or [2], in which the polyisocyanate component includes an alicyclic polyisocyanate.

[0013] The present invention [4] includes the polyurethane dispersion according to any one of the above [1] to [3], in which the macropolyol includes a polyether polyol. [Effects of the Invention]

[0014] The polyurethane dispersion of the present invention is a polyurethane dispersion obtained by dispersing a polyurethane resin in water, the polyurethane resin being a reaction product of an isocyanate-terminated prepolymer and a chain extender. The isocyanate-terminated prepolymer is a reaction product of a polyisocyanate component and a polyol component containing a macropolyol, an anionic group-containing active hydrogen compound, and a polyoxyethylene-containing monool. The polyurethane resin has an acid value of 4.0 mgKOH / g or more and 10.0 mgKOH / g or less, and the polyoxyethylene content of the polyoxyethylene-containing monool in the polyurethane resin is 2.5% by mass or more and 7.5% by mass or less. Therefore, the polyurethane dispersion of the present invention is excellent in all aspects of color development, adhesion, shrinkage resistance, texture, and washing fastness. [Brief explanation of the drawings]

[0015] [Figure 1] 1A to 1C are schematic diagrams of printed fabrics (printed items). FIG. 1A shows a printed item with excellent color development but poor adhesion. FIG. 1B shows a printed item with excellent adhesion but poor color development. FIG. 1C shows a printed item that achieves both excellent color development and good adhesion. DETAILED DESCRIPTION OF THE INVENTION

[0016] The polyurethane dispersion is prepared by dispersing a polyurethane resin in water.

[0017] The polyurethane resin is a reaction product of an isocyanate-terminated prepolymer and a chain extender.

[0018] <Isocyanate-terminated prepolymer> The isocyanate-terminated prepolymer is a reaction product of a polyisocyanate component and a polyol component.

[0019] [Polyisocyanate component] The polyisocyanate component includes polyisocyanate and / or a derivative of polyisocyanate.

[0020] (Polyisocyanate) Examples of polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates.

[0021] Examples of aliphatic polyisocyanates include aliphatic diisocyanates. Examples of aliphatic diisocyanates include 1,6-hexamethylene diisocyanate (1,6-HDI), 1,5-pentamethylene diisocyanate (1,5-PDI), tetramethylene diisocyanate, trimethylene diisocyanate, 1,2-, 2,3-, or 1,3-butylene diisocyanate, and 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate. Examples of aliphatic polyisocyanates include preferably aliphatic diisocyanates, more preferably 1,6-HDI and 1,5-PDI.

[0022] Examples of alicyclic polyisocyanates include alicyclic diisocyanates. Examples of alicyclic diisocyanates include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4'-, 2,4'-, or 2,2'-methylenebis(cyclohexyl isocyanate), or mixtures thereof (H 12 Examples of the alicyclic polyisocyanate include 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane or a mixture thereof (H6XDI), bis(isocyanatomethyl)norbornane (NBDI), 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, and methyl-2,6-cyclohexane diisocyanate. The alicyclic polyisocyanate is preferably an alicyclic diisocyanate, more preferably IPDI, H 12 MDI and H6XDI are preferred, IPDI and H6XDI are more preferred, H6XDI is particularly preferred, and 1,3-H6XDI is most preferred.

[0023] Examples of aromatic polyisocyanates include aromatic diisocyanates, such as 4,4'-, 2,4'-, or 2,2'-diphenylmethane diisocyanate or a mixture thereof (MDI), 2,4- or 2,6-tolylene diisocyanate or a mixture thereof (TDI), o-tolidine diisocyanate, 1,5-naphthalene diisocyanate (NDI), m- or p-phenylene diisocyanate or a mixture thereof, 4,4'-diphenyl diisocyanate, and 4,4'-diphenyl ether diisocyanate.

[0024] Examples of araliphatic polyisocyanates include araliphatic diisocyanates. Examples of araliphatic diisocyanates include xylylene diisocyanate (1,2-, 1,3-, or 1,4-xylylene diisocyanate or a mixture thereof) (XDI), 1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (TMXDI), and ω,ω'-diisocyanato-1,4-diethylbenzene. Examples of araliphatic polyisocyanates include preferably araliphatic diisocyanates, more preferably XDI, and even more preferably 1,3-XDI.

[0025] The polyisocyanate is preferably an aliphatic polyisocyanate, an alicyclic polyisocyanate, or an araliphatic polyisocyanate. From the viewpoint of improving color development and washing fastness, the polyisocyanate is more preferably an alicyclic polyisocyanate or an araliphatic polyisocyanate. The polyisocyanate is even more preferably an alicyclic polyisocyanate.

[0026] The polyisocyanates can be used alone or in combination of two or more kinds.

[0027] (Polyisocyanate derivatives) Examples of the polyisocyanate derivatives include the above-mentioned polyisocyanate polymers, allophanate derivatives, polyol derivatives, biuret derivatives, urea derivatives, oxadiazinetrione derivatives, carbodiimide derivatives, uretdione derivatives, and uretonimine derivatives.

[0028] The polyisocyanate derivatives can be used alone or in combination of two or more kinds.

[0029] The polyisocyanate component preferably does not contain a derivative of polyisocyanate and is composed of polyisocyanate, and more preferably is composed of alicyclic polyisocyanate.

[0030] [Polyol component] The polyol component is a hydroxyl group-containing component that includes at least a polyol.

[0031] The polyol component includes a macropolyol, an anionic group-containing active hydrogen compound, and a polyoxyethylene-containing monool.

[0032] (macropolyol) The macropolyol is a compound having two or more hydroxyl groups at the molecular terminals and a number average molecular weight of 400 or more, preferably 500 or more, and 10,000 or less, preferably 5,000 or less, more preferably 3,000 or less. The number average molecular weight (polystyrene equivalent) of the macropolyol can be measured by gel permeation chromatography (the same applies hereinafter).

[0033] The average functionality of the macropolyol is, for example, 2 or more, and for example, 3 or less, and preferably 2.

[0034] Examples of the macropolyol include polyether polyol, polyester polyol, polycarbonate polyol, polyurethane polyol, epoxy polyol, polyolefin polyol, acrylic polyol, silicone polyol, fluorine polyol, and vinyl monomer-modified polyol. Preferred examples of the macropolyol include polycarbonate polyol and polyether polyol, and more preferred examples of the macropolyol include polyether polyol.

[0035] Examples of polyether polyols include polyoxyalkylene (having 2 to 3 carbon atoms) polyols and polytetramethylene ether polyols.

[0036] Examples of polyoxyalkylene (C2-3) polyols include low-molecular-weight polyols described below and addition polymers of alkylene oxides having C2-3 using known low-molecular-weight polyamines as initiators.

[0037] Examples of alkylene oxides having 2 to 3 carbon atoms include propylene oxide and ethylene oxide. These alkylene oxides can be used alone or in combination of two or more.

[0038] Specific examples of polyoxyalkylene (C2-3) polyols include polyoxypropylene glycol and random and / or block copolymers of propylene oxide and ethylene oxide. Note that polyoxyalkylene (C2-3) polyols preferably do not include polyoxyethylene polyols.

[0039] Furthermore, the polyoxyalkylene (carbon number 2 to 3) polyol also includes polytrimethylene ether glycol.

[0040] An example of polytrimethylene ether glycol is a glycol obtained by polycondensation reaction of 1,3-propanediol derived from plant components.

[0041] Examples of polytetramethylene ether polyols include ring-opening polymers (crystalline polytetramethylene ether glycols) obtained by cationic polymerization of tetrahydrofuran, and amorphous (non-crystalline) polytetramethylene ether glycols in which alkyl-substituted tetrahydrofuran or dihydric alcohols (described later) are copolymerized with polymerization units of tetrahydrofuran or the like.

[0042] As the polyether polyol, preferably, polytetramethylene ether polyol is used, and more preferably, polytetramethylene ether glycol is used.

[0043] The macropolyols can be used alone or in combination of two or more kinds.

[0044] The blending ratio of the macropolyol is, for example, 70 parts by mass or more, preferably 80 parts by mass or more, more preferably 85 parts by mass or more, and even more preferably 90 parts by mass or more, and for example, 98 parts by mass or less, per 100 parts by mass of the total amount of the polyol components.

[0045] (Anionic group-containing active hydrogen compounds) The anionic group-containing active hydrogen compound is a compound containing one or more anionic groups and two or more active hydrogen groups.

[0046] Examples of anionic groups include carboxy groups (carboxylic acid groups) and sulfo groups (sulfonic acid groups), preferably carboxy groups. Examples of active hydrogen groups include hydroxy groups and amino groups, preferably hydroxy groups. That is, preferred examples of anionic group-containing active hydrogen compounds include organic compounds having both carboxy groups and two or more hydroxy groups.

[0047] Examples of organic compounds having both a carboxy group and two or more hydroxyl groups include carboxy group-containing polyols. Examples of carboxy group-containing polyols include polyhydroxyalkanoic acids. Examples of polyhydroxyalkanoic acids include dihydroxyalkanoic acids. Examples of dihydroxyalkanoic acids include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid (DMPA) (also known as dimethylolpropionic acid), 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid.

[0048] As the anionic group-containing active hydrogen compound, from the viewpoint of setting the acid value of the polyurethane resin described below within a predetermined range and maintaining good dispersion stability of the urethane resin, preferably a carboxy group-containing polyol, more preferably a polyhydroxyalkanoic acid, even more preferably a dihydroxyalkanoic acid, and particularly preferably 2,2-dimethylolpropionic acid (DMPA) is used.

[0049] The anionic group-containing active hydrogen compounds can be used alone or in combination of two or more.

[0050] The mixing ratio of the anionic group-containing active hydrogen compound relative to 100 parts by mass of the total amount of the polyol components is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 1.25 parts by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass or less, more preferably 2.5 parts by mass or less, even more preferably 2 parts by mass or less.

[0051] By adjusting the blending ratio of the anionic group-containing active hydrogen compound within the above range, the acid value of the polyurethane resin described below is adjusted to a predetermined range, thereby maintaining good dispersion stability of the urethane resin.

[0052] (Polyoxyethylene-containing monool) The polyoxyethylene-containing monool is a compound containing at least four consecutive oxyethylene groups (ethylene oxide groups) and one hydroxyl group.

[0053] An example of the polyoxyethylene-containing monool is one-end-blocked polyoxyethylene glycol.

[0054] Examples of the alkyl group for blocking one end include alkyl groups having 1 to 4 carbon atoms, preferably alkyl groups having 1 to 2 carbon atoms (methyl or ethyl groups), and particularly preferably alkyl groups having 1 carbon atom (methyl group).

[0055] Examples of one-end-capped polyoxyethylene glycols include alkoxypolyoxyethylene glycols (poly(oxyethylene) alkyl ethers) in which one end is capped with an alkyl group having 1 to 4 carbon atoms. Examples of alkoxypolyoxyethylene glycols in which one end is capped with an alkyl group having 1 to 4 carbon atoms include methoxypolyoxyethylene monool (poly(oxyethylene) methyl ether) and ethoxypolyoxyethylene monool (poly(oxyethylene) ethyl ether).

[0056] The polyoxyethylene-containing monool is preferably a one-end-capped polyoxyethylene glycol, more preferably a polyoxyethylene glycol one-end-capped with an alkyl group having 1 to 4 carbon atoms, even more preferably a methoxypolyoxyethylene monool (poly(oxyethylene) methyl ether) or an ethoxypolyoxyethylene monool (poly(oxyethylene) ethyl ether), and particularly preferably a methoxypolyoxyethylene monool.

[0057] Such polyoxyethylene-containing monools can be used alone or in combination of two or more kinds.

[0058] The number average molecular weight of such polyoxyethylene-containing monool is, for example, 200 or more, preferably 300 or more, more preferably 400 or more, and even more preferably 500 or more, and for example, 2000 or less, preferably 1500 or less, and more preferably 1000 or less. The number average molecular weight (polystyrene equivalent) of the polyoxyethylene-containing monool can be measured by gel permeation chromatography (the same applies hereinafter).

[0059] The polyoxyethylene-containing monool is, relative to 100 parts by mass of the total amount of the polyol components, for example, 1 part by mass or more, preferably 2 parts by mass or more, more preferably 3 parts by mass or more, even more preferably 3.5 parts by mass or more, particularly preferably 3.7 parts by mass or more, particularly preferably 4.0 parts by mass or more, and most preferably 6.0 parts by mass or more, and for example, less than 11.5 parts by mass, preferably 11.0 parts by mass or less, more preferably 10.0 parts by mass or less, even more preferably 9.0 parts by mass or less, particularly preferably 8.0 parts by mass or less, particularly preferably 7.5 parts by mass or less, and most preferably 7.4 parts by mass or less.

[0060] The polyoxyethylene content (content of polyoxyethylene repeating units) of the polyoxyethylene-containing monool in the polyurethane resin is, for example, 2.5 mass% or more, preferably 2.75 mass% or more, more preferably 3.0 mass% or more, even more preferably 5.0 mass% or more, and for example, 7.5 mass% or less, preferably 7.0 mass% or less, more preferably 6.5 mass% or less, even more preferably 6.0 mass% or less.

[0061] If the polyoxyethylene content of the polyoxyethylene-containing monool in the polyurethane resin is less than the above lower limit, the polyurethane resin will have poor water dispersibility.

[0062] If the polyoxyethylene content of the polyoxyethylene-containing monool in the polyurethane resin exceeds the upper limit, the color development properties will be poor.

[0063] (Low molecular weight polyol) The polyol component may also contain a low molecular weight polyol (excluding anionic group-containing active hydrogen compounds).

[0064] The low-molecular-weight polyol is a compound having two or more hydroxyl groups at the molecular terminals and a number-average molecular weight of 40 or more but less than 400, preferably 300 or less.

[0065] The functionality of the low molecular weight polyol is, for example, 2 or more, and, for example, 3 or less. The functionality of the low molecular weight polyol is preferably 2.

[0066] Low molecular weight polyols include, for example, dihydric alcohols and trihydric alcohols.

[0067] Examples of dihydric alcohols include alkanediols having 2 to 6 carbon atoms and etherdiols.

[0068] Examples of alkanediols having 2 to 6 carbon atoms include ethylene glycol, propylene glycol (1,2- or 1,3-propanediol or a mixture thereof), butylene glycol (1,2-, 1,3-, or 1,4-butanediol or a mixture thereof), 1,5-pentanediol, 1,6-hexanediol, and neopentyl glycol.

[0069] Examples of the ether diol having 2 to 6 carbon atoms include diethylene glycol, triethylene glycol, and dipropylene glycol.

[0070] Examples of trihydric alcohols include glycerin and trimethylolpropane.

[0071] The low molecular weight polyol is preferably a dihydric alcohol, more preferably an alkanediol having 2 to 6 carbon atoms.

[0072] The polyol component preferably does not contain a low-molecular-weight polyol, but contains a macropolyol (preferably excluding polyoxyethylene polyol), an anionic group-containing active hydrogen compound, and a polyoxyethylene-containing monool. The polyol component more preferably consists of a macropolyol (preferably excluding polyoxyethylene polyol), an anionic group-containing active hydrogen compound, and a polyoxyethylene-containing monool.

[0073] [Preparation of isocyanate-terminated prepolymer] The isocyanate-terminated prepolymer can be obtained by reacting a polyisocyanate component with a polyol component.

[0074] As a method for reacting the polyisocyanate component and the polyol component, a known polymerization method (e.g., bulk polymerization or solution polymerization) is selected, and preferably, solution polymerization is selected from the viewpoint of easier adjustment of reactivity and viscosity.

[0075] In solution polymerization, for example, the above components are mixed in an organic solvent (solvent) under a nitrogen atmosphere and reacted.

[0076] In this reaction, the equivalent ratio of isocyanate groups in the polyisocyanate component to hydroxyl groups in the polyol component (isocyanate groups / hydroxyl groups) exceeds 1, for example, 1.1 or more, preferably 1.2 or more, for example, 2.5 or less, preferably 2.0 or less. In such a case, the terminal functional group of the resulting reaction product is an isocyanate group. In other words, an isocyanate-terminated prepolymer is obtained.

[0077] As for reaction conditions, the reaction temperature is, for example, 20° C. or higher and, for example, 90° C. or lower, and the reaction time is, for example, 1 hour or longer and, for example, 20 hours or shorter.

[0078] Examples of the organic solvent include those which are inert to isocyanate groups and highly hydrophilic, such as acetone, methyl ethyl ketone, ethyl acetate, tetrahydrofuran, acetonitrile, and N-methylpyrrolidone. Acetonitrile is preferred.

[0079] In the polymerization, a reaction catalyst (for example, an amine-based, tin-based, titanium-based, or lead-based catalyst) may be added as needed.

[0080] In the above reaction, unreacted polyisocyanate components can be removed by known methods such as distillation or extraction.

[0081] This produces an isocyanate-terminated prepolymer, which is a reaction product of the polyisocyanate component and the polyol component.

[0082] When the polyisocyanate component and the polyol component are reacted by solution polymerization, the isocyanate-terminated prepolymer is obtained as a reaction liquid containing the isocyanate-terminated prepolymer and an organic solvent.

[0083] The isocyanate-terminated prepolymer is a polyurethane prepolymer having at least one (preferably multiple, more preferably two or one) free isocyanate group at its molecular terminal. The isocyanate group content (isocyanate group content calculated as solid content excluding solvent, i.e., isocyanate group concentration) is, for example, 0.5% by mass or more, preferably 1.0% by mass or more, more preferably 1.5% by mass or more, and for example, 5% by mass or less, preferably 4% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less.

[0084] Furthermore, the anionic groups contained in the reaction product are preferably neutralized by adding a neutralizing agent to form salts of the anionic groups.

[0085] The neutralizing agent may be a commonly used base, such as an organic base or an inorganic base. Examples of organic bases include tertiary amines and secondary amines. Examples of tertiary amines include trialkylamines and alkanolamines. Examples of trialkylamines include trialkylamines having 1 to 4 carbon atoms. Examples of trialkylamines having 1 to 4 carbon atoms include trimethylamine and triethylamine. Examples of alkanolamines include dimethylethanolamine, methyldiethanolamine, triethanolamine, and triisopropanolamine. Examples of secondary amines include heterocyclic amines. Examples of heterocyclic amines include morpholine. Examples of inorganic bases include ammonia, alkali metal hydroxides, alkaline earth metal hydroxides, and alkali metal carbonates. Examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of alkaline earth metal hydroxides include magnesium hydroxide and calcium hydroxide. Examples of alkali metal carbonates include sodium carbonate and potassium carbonate. These neutralizing agents can be used alone or in combination.

[0086] The neutralizing agent is preferably an organic base, more preferably a tertiary amine, even more preferably a trialkylamine, and particularly preferably triethylamine. That is, the neutralizing agent is preferably an organic base, more preferably a tertiary amine, even more preferably a trialkylamine, and particularly preferably triethylamine.

[0087] The neutralizing agent is added in a proportion of 0.4 equivalents or more, preferably 0.6 equivalents or more, per equivalent of anionic group, and for example, 1.2 equivalents or less, preferably 1.1 equivalents or less.

[0088] <Chain extender> Examples of the chain extender include the above-mentioned low molecular weight polyols and amino group-containing compounds.

[0089] Examples of the amino group-containing compound include aromatic polyamines, araliphatic polyamines, alicyclic polyamines, aliphatic polyamines, amino alcohols, alkoxysilyl compounds having a primary amino group or a primary amino group and a secondary amino group, and hydrazine or a derivative thereof.

[0090] Examples of aromatic polyamines include 4,4'-diphenylmethanediamine and tolylenediamine.

[0091] Araliphatic polyamines include, for example, 1,3- or 1,4-xylylenediamine or mixtures thereof.

[0092] Examples of alicyclic polyamines include 3-aminomethyl-3,5,5-trimethylcyclohexylamine (also known as isophoronediamine), 4,4'-dicyclohexylmethanediamine, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane, 1,4-cyclohexanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis-(4-aminocyclohexyl)methane, diaminocyclohexane, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, 1,3- and 1,4-bis(aminomethyl)cyclohexane, and mixtures thereof.

[0093] Examples of aliphatic polyamines include ethylenediamine, propylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 1,2-diaminoethane, 1,2-diaminopropane, and 1,3-diaminopentane.

[0094] Examples of amino alcohols include 2-((2-aminoethyl)amino)ethanol (also known as N-(2-aminoethyl)ethanolamine) and 2-((2-aminoethyl)amino)-1-methylpropanol (also known as N-(2-aminoethyl)isopropanolamine), and preferably 2-((2-aminoethyl)amino)ethanol (also known as N-(2-aminoethyl)ethanolamine).

[0095] Examples of alkoxysilyl compounds having a primary amino group or a primary amino group and a secondary amino group include alkoxysilyl compounds having a primary amino group and alkoxysilyl compounds having a primary amino group and a secondary amino group. Examples of alkoxysilyl compounds having a primary amino group include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane. Examples of alkoxysilyl compounds having a primary amino group and a secondary amino group include N-β(aminoethyl)γ-aminopropyltrimethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane), N-β(aminoethyl)γ-aminopropyltriethoxysilane (also known as N-2-(aminoethyl)-3-aminopropyltriethoxysilane), N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane (also known as N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane), and N-β(aminoethyl)γ-aminopropylmethyldiethoxysilane (also known as N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane). Preferred examples of alkoxysilyl compounds having a primary amino group or a primary amino group and a secondary amino group include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane.

[0096] Examples of hydrazine or its derivatives include hydrazine (including hydrazine monohydrate), succinic acid dihydrazide, and adipic acid dihydrazide.Preferably, hydrazine or its derivatives is hydrazine monohydrate.

[0097] The chain extender is preferably hydrazine or a derivative thereof, or an alkoxysilyl compound having a primary amino group or a primary amino group and a secondary amino group, and more preferably hydrazine or a derivative thereof.

[0098] The chain extender can also be prepared, for example, as an aqueous solution (aqueous chain extender solution).

[0099] The chain extenders can be used alone or in combination of two or more.

[0100] (monoamines) In the reaction between the prepolymer and the chain extender, a monoamine may be optionally used in combination with the chain extender.

[0101] Monoamines are compounds that contain one amino group. Because they contain one amino group, they are reaction terminators in the chain extension reaction described below.

[0102] Examples of monoamines include alkylamines and dialkylamines. Examples of alkylamines include 2-ethylhexylamine and cyclohexylamine. Examples of dialkylamines include diethylamine, dipropylamine, and dibutylamine.

[0103] As the monoamine, preferably, dialkylamine is used, and more preferably, diethylamine is used.

[0104] The content of the monoamine relative to the polyurethane resin is, for example, 0 mass% or more, preferably 0.1 mass% or more, more preferably 0.2 mass% or more, even more preferably 0.3 mass% or more, and for example, 10 mass% or less, preferably 5 mass% or less, more preferably 1 mass% or less, even more preferably 0.75 mass% or less, and particularly preferably 0.5 mass% or less.

[0105] The total amount of monoamine and polyoxyethylene-containing monool, relative to the resin solid content of the polyurethane dispersion, is, for example, 0.001 mmol / g or more, preferably 0.01 mmol / g or more, more preferably 0.02 mmol / g or more, even more preferably 0.03 mmol / g or more, and for example, 1 mmol / g or less, preferably 0.5 mmol / g or less, more preferably 0.2 mmol / g or less, even more preferably 0.15 mmol / g or less, and particularly preferably 0.12 mmol / g or less.

[0106] Preferably, no monoamine is used in combination with the chain extender.

[0107] <Preparation of polyurethane resin> The polyurethane resin can be obtained by reacting an isocyanate-terminated prepolymer with a chain extender and, if necessary, a monoamine.

[0108] Specifically, an isocyanate group-terminated prepolymer, a chain extender, and optionally a monoamine are reacted in, for example, water to obtain a polyurethane resin (polyurethane dispersion).

[0109] To react an isocyanate group-terminated prepolymer with a chain extender and, if necessary, a monoamine in water, for example, first, the isocyanate group-terminated prepolymer is added to water to disperse the isocyanate group-terminated prepolymer in water, and then, a chain extender and, if necessary, a monoamine are added thereto to extend the chain of the isocyanate group-terminated prepolymer with the chain extender.

[0110] To disperse the isocyanate-terminated prepolymer in water, the isocyanate-terminated prepolymer is added to 100 parts by mass of isocyanate-terminated prepolymer in 50 to 1000 parts by mass of water (sometimes referred to as water dispersion water) while stirring the water.

[0111] Thereafter, the chain extender is added dropwise to the water in which the isocyanate group-terminated prepolymer has been dispersed, while stirring, so that the equivalent ratio (active hydrogen groups / isocyanate groups) of the active hydrogen groups (total of amino groups and hydroxyl groups) of the chain extender to the isocyanate groups of the isocyanate group-terminated prepolymer is, for example, 0.5 or more and 1.5 or less.

[0112] When a monoamine is added as needed, the monoamine is added together with the chain extender in the above-mentioned proportions. The molecular weight of the polyurethane resin can be adjusted depending on the proportion of the monoamine added.

[0113] When the above-mentioned aqueous solution of chain extender is added, the chain extender and, if necessary, the monoamine are added simultaneously or sequentially.

[0114] Conversely to the above, water can be added to the isocyanate group-terminated prepolymer to disperse the isocyanate group-terminated prepolymer in water, and then a chain extender and, if necessary, a monoamine can be added thereto to extend the chains of the isocyanate group-terminated prepolymer with the chain extender.

[0115] In this method, the organic solvent and water can be removed as needed, and further, water can be added to adjust the solid content concentration.

[0116] This allows the chain of the isocyanate-terminated prepolymer to be extended by the chain extender, thereby obtaining a polyurethane resin prepared as an aqueous dispersion (polyurethane dispersion).

[0117] The acid value of the polyurethane resin is, for example, 4.0 mgKOH / g or more, preferably 4.25 mgKOH / g or more, more preferably 4.5 mgKOH / g or more, even more preferably 4.6 mgKOH / g or more, and for example, 10.0 mgKOH / g or less, preferably 9.5 mgKOH / g or less, more preferably 9.2 mgKOH / g or less, even more preferably 9.0 mgKOH / g or less, particularly preferably 6.0 mgKOH / g or less, and most preferably 5.0 mgKOH / g or less.

[0118] The acid value can be adjusted to fall within the above range, for example, by adjusting the blending ratio of the anionic group (preferably a carboxy group)-containing active hydrogen group-containing compound.

[0119] If the acid value is equal to or greater than the lower limit, when a fabric (described later) is printed, the color developability is improved (i.e., the color density is increased on the surface of the fabric (described later)), and the adhesion, shrinkage resistance, texture, and washing fastness are excellent.

[0120] On the other hand, if the acid value is less than the lower limit, color development will be reduced when printing fabric (described later).

[0121] Furthermore, if the acid value is equal to or less than the upper limit, when a fabric (described later) is printed, adhesion is improved and color development, shrinkage resistance, texture, and washing fastness are excellent.

[0122] On the other hand, if the acid value exceeds the upper limit, adhesion decreases when printing fabrics (described later).

[0123] The acid value is calculated from the ratio of the raw material components.

[0124] The solids concentration of the polyurethane dispersion is, for example, 10% by mass or more, preferably 20% by mass or more, and for example, 50% by mass or less, preferably 40% by mass or less.

[0125] The breaking elongation of the dried polyurethane dispersion is, for example, 550% or more, preferably 600% or more, more preferably 650% or more, even more preferably 700% or more, particularly preferably 725% or more, most preferably 750% or more, and even most preferably 800% or more, and is, for example, 1200% or less, preferably 1100% or less, more preferably 1090% or less, even more preferably 1050% or less, particularly preferably 1020% or less, most preferably 1000% or less, and even most preferably 950% or less.

[0126] The breaking elongation is the same as in the examples described below. and reference examples The test shall conform to the tensile test.

[0127] <Use of polyurethane dispersion> The polyurethane dispersion is suitably used as a resin for dispersing coloring materials in the ink composition.

[0128] The ink composition is a raw material for printing fabrics.

[0129] Examples of fabrics include natural fibers and chemical fibers. Examples of natural fibers include cotton, silk, wool, and hemp. Examples of chemical fibers include polypropylene fibers, polyester fibers, and polyamide fibers.

[0130] The ink composition contains a colorant and the polyurethane dispersion.

[0131] The coloring material includes dyes and pigments. There are no particular limitations on the coloring material, and known coloring materials can be used.

[0132] The polyurethane dispersion is a component that disperses the coloring material in the ink composition.

[0133] The mixing ratio of the polyurethane dispersion relative to 100 parts by mass of the colorant is, for example, 300 parts by mass or more, and for example, 1000 parts by mass or less, preferably 700 parts by mass or less.

[0134] The ink composition is then prepared by mixing the colorant and the polyurethane dispersion.

[0135] Furthermore, the ink composition may contain known additives (for example, a humectant (such as ethylene glycol), a penetrating agent, a chelating agent, a preservative, a pH adjuster, an antioxidant, and a viscosity adjuster) as needed. In other words, the ink composition contains known additives as needed.

[0136] The ink composition can also be diluted with water and / or an organic solvent (eg, ethylene glycol).

[0137] Next, a method for printing fabric using this ink composition will be described in detail.

[0138] When printing a fabric using an ink composition, the fabric is first pretreated. If the fabric is not pretreated, the interaction between the fabric and the ink composition is weak, and the ink composition penetrates into the fabric, resulting in a decrease in color development. In particular, when the fabric is made of chemical fibers, the above-mentioned interaction is weaker than that of natural fibers, and the above-mentioned decrease in color development becomes more pronounced.

[0139] On the other hand, if the fabric is pretreated, the ink composition aggregates on the surface of the fabric due to the interaction between the fabric and the ink composition, thereby suppressing the ink composition from penetrating into the fabric, thereby improving color development.

[0140] To pretreat the fabric, the fabric is treated with a pretreatment agent.

[0141] Examples of pretreatment agents include organic acids and their salts (e.g., acetic acid and sodium acetate), polyvalent metal salts, and cationic compounds. Preferable pretreatment agents include organic acids. The pretreatment agent can also be prepared as an aqueous solution.

[0142] To treat a fabric with a pretreatment agent, the pretreatment agent is applied to the fabric. A known method (for example, a spray method) is selected as the method for applying the pretreatment agent to the fabric.

[0143] Next, the ink composition is applied to the fabric. A known method (for example, a spray method or an inkjet method) is selected as the method for applying the ink composition to the fabric. In this way, the ink composition is applied to the fabric.

[0144] Then, if necessary, an overcoat agent is applied to the fabric.

[0145] Examples of the overcoat agent include a known aqueous dispersion of blocked isocyanate.

[0146] The overcoat agent can be applied by any known method (for example, spraying or ink-jet printing).

[0147] Next, the fabric (the fabric to which the ink composition has been applied) is heated.

[0148] The heating temperature is, for example, 80° C. or higher, preferably 100° C. or higher, and for example, 120° C. or lower. The heating time is, for example, 1 minute or longer, preferably 5 minutes or longer, and for example, 60 minutes or shorter, preferably 40 minutes or shorter, more preferably 30 minutes or shorter.

[0149] This results in printing of the fabric (i.e., obtaining a printed product).

[0150] Since the ink composition contains the polyurethane dispersion described above, it is possible to produce printed items that are excellent in all respects: color development, adhesion, shrinkage resistance, texture, and washing fastness.

[0151] <Action and effect> In the polyurethane dispersion, the isocyanate-terminated prepolymer is a reaction product of a polyisocyanate component with a polyol component containing a macropolyol, an anionic group-containing active hydrogen compound, and a polyoxyethylene-containing monool, and the acid value of the polyurethane resin and the polyoxyethylene content of the polyoxyethylene-containing monool of the polyurethane resin are within a predetermined range, thereby providing excellent color development and adhesion when used for textile printing.

[0152] There is a trade-off between color development and adhesion.

[0153] 1A, when a fabric 1 is printed, if most of the polyurethane dispersion 2 (specifically, the ink composition containing the polyurethane dispersion 2) remains on the surface 3 of the fabric 1, the color density at the surface 3 of the fabric 1 increases, improving color development. On the other hand, in such a case, the polyurethane dispersion 2 (specifically, the ink composition containing the polyurethane dispersion 2) hardly penetrates into the fabric 1, and therefore the adhesion between the fabric 1 and the polyurethane dispersion 2 (specifically, the ink composition containing the polyurethane dispersion 2) decreases.

[0154] 1B, adhesion improves when most of the polyurethane dispersion 2 (specifically, the ink composition containing the polyurethane dispersion 2) penetrates into the fabric 1. On the other hand, in this case, almost no polyurethane dispersion 2 (specifically, the ink composition containing the polyurethane dispersion 2) is present on the surface 3 of the fabric 1, and color development deteriorates.

[0155] Therefore, in order to achieve both color development and adhesion, it is considered to adjust the polyurethane dispersion 2 (specifically, the ink composition containing the polyurethane dispersion 2) that remains on the surface 3 of the fabric 1 and the polyurethane dispersion 2 (specifically, the ink composition containing the polyurethane dispersion 2) that soaks into the fabric 1. Specifically, as shown in Fig. 1C, the polyurethane dispersion 2 (specifically, the ink composition containing the polyurethane dispersion 2) is adjusted to an extent that it remains on the surface 3 of the fabric 1 and soaks into the surface 3 of the fabric 1.

[0156] In this polyurethane dispersion, the isocyanate-terminated prepolymer is a reaction product of a polyisocyanate component with a polyol component containing a macropolyol, an anionic group-containing active hydrogen compound, and a polyoxyethylene-containing monool, and by adjusting the acid value of the polyurethane resin and the polyoxyethylene content of the polyoxyethylene-containing monool of the polyurethane resin within predetermined ranges, it is possible to achieve the adjustment shown in Figure 1C. As a result, it is possible to achieve both color development and adhesion.

[0157] Specifically, when the acid value of the polyurethane resin is high, the polyurethane dispersion (specifically, the ink composition containing the polyurethane dispersion) tends to aggregate on the surface of the fabric due to interaction with the pretreatment agent (preferably organic acid ions) in the fabric. This can improve color development, but tends to reduce adhesion.

[0158] On the other hand, when the acid value of the polyurethane resin is low, the polyurethane dispersion (specifically, the ink composition containing the polyurethane dispersion) is less likely to aggregate due to interaction with the pretreatment agent (preferably, organic acid ions) in the fabric. As a result, the polyurethane dispersion (specifically, the ink composition containing the polyurethane dispersion) is more likely to penetrate into the fabric. This can improve adhesion, but tends to reduce color development.

[0159] In addition, since the acid value of this polyurethane dispersion is adjusted to fall within a predetermined range, it is possible to achieve both color development and adhesion.

[0160] In addition, polyoxyethylene chains (at least four consecutive oxyethylene groups) increase the dispersion stability of the urethane resin. This reduces the aggregation of the urethane resin, making it easier to penetrate. As a result, the polyurethane dispersion (specifically, the ink composition containing the polyurethane dispersion) is more likely to penetrate into the fabric. While this improves adhesion, it also tends to reduce color development.

[0161] On the other hand, if the polyoxyethylene content of the polyoxyethylene-containing monool of the polyurethane resin is low, the hydrophilicity decreases, and the dispersion of the polyurethane dispersion (specifically, the ink composition containing the polyurethane dispersion) becomes insufficient.

[0162] In this polyurethane dispersion, the polyoxyethylene content of the polyoxyethylene-containing monool of the polyurethane resin is adjusted to a predetermined range, which ensures appropriate compatibility with the pretreatment agent and sufficient dispersion of the polyurethane dispersion, thereby achieving both good color development and adhesion.

[0163] In other words, in this polyurethane dispersion, both color development and adhesion can be achieved by adjusting the acid value of the polyurethane resin and the polyoxyethylene content of the polyoxyethylene-containing monool of the polyurethane resin within a predetermined range.

[0164] Furthermore, this polyurethane dispersion contains a polyoxyethylene-containing monool as a polyol component. Therefore, compared to polyurethane dispersions containing polyurethane resins having polyoxyethylene units in their side chains, as shown in Patent Document 1, the main chain molecular weight of the polyurethane resin can be adjusted, and in addition to color development and adhesion, the polyurethane dispersion is excellent in shrinkage resistance and texture, and is particularly excellent in shrinkage resistance. As a result, this polyurethane dispersion can achieve both color development and adhesion as described above, and is also excellent in all of shrinkage resistance, texture, and washing fastness. [Example]

[0165] Specific numerical values ​​of blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be replaced with the corresponding upper limit values ​​(numeric values ​​defined as "not more than" or "less than") or lower limit values ​​(numeric values ​​defined as "not less than" or "exceeding") of blending ratios (content ratios), physical property values, parameters, etc. described in the above "Description of the Invention." Furthermore, unless otherwise specified in the following description, "parts" and "%" are based on mass.

[0166] <Ingredient details> H6XDI: 1,3-bis(isocyanatomethyl)cyclohexane, trade name "Takenate 600", manufactured by Mitsui Chemicals, Inc. IPDI: Isophorone diisocyanate, Vestanat IPDI, manufactured by Evonik H 12 MDI: Methylenebis(cyclohexyl isocyanate), trade name "Vestanat H 12 MDI" manufactured by Evonik XDI: 1,3-xylylene diisocyanate, product name "Takenate 500", manufactured by Mitsui Chemicals, Inc. HDI: Hexamethylene diisocyanate, product name "Takenate 700", manufactured by Mitsui Chemicals, Inc. PDI: 1,5-pentamethylene diisocyanate, trade name "Stabio PDI", manufactured by Mitsui Chemicals PTG2000SN: Polytetramethylene ether glycol (number average molecular weight: 2000), manufactured by Hodogaya Chemical Co., Ltd. UH-200: Polycarbonate diol (number average molecular weight: 2000), product name "ETERNACOLL UH-200", manufactured by Ube Industries, Ltd. DMPA: 2,2-dimethylolpropionic acid Methoxy PEG-1000: methoxypolyoxyethylene monool (polyethylene glycol monomethyl ether) (number average molecular weight: 1000), manufactured by Toho Chemical Industry Co., Ltd. Uniox M-550: Methoxypolyoxyethylene monool (polyethylene glycol monomethyl ether) (number average molecular weight: 550), manufactured by NOF Corporation Ymer 120: Diol with methoxypolyoxyethylene side chains (number average molecular weight: 1000), manufactured by Perstorp TEA: Triethylamine D-170N: Isocyanurate derivative of hexamethylene diisocyanate (HDI) (polyisocyanate compound, trade name "Takenate (registered trademark) D-170N", solid content 100% by weight, isocyanate group content 20.7%), manufactured by Mitsui Chemicals, Inc. MEK: Methyl ethyl ketone DMP: dimethylpyrazole

[0167] <Preparation of polyurethane dispersion> Example 1 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube was charged with 230.25 parts by mass of PTG2000SN (macropolyol) (OH (1)). Next, 42.17 parts by mass of H6XDI (polyisocyanate component) was added, and the urethane reaction was carried out at 80 ° C. for 2 hours. To this reaction solution, 3.3 parts by mass of DMPA (anionic group-containing active hydrogen compound) (OH (2)), 18.6 parts by mass of methoxy PEG-1000 (polyoxyethylene-containing monool) (OH (2)), and 39.95 parts by mass of acetonitrile (acetonitrile (1)) were added, and the urethane reaction was carried out at 80 ° C. until the NCO concentration reached 1.71% by mass, resulting in an isocyanate-terminated prepolymer (a reaction solution containing an isocyanate-terminated prepolymer).

[0168] Next, 183.92 parts by mass of acetonitrile (acetonitrile (2)) was added to this reaction liquid, and after cooling to 30°C, 2.44 parts by mass of triethylamine (TEA) (neutralizing agent) was added. Next, the mixture was cooled to below 20°C, and 806.45 parts by mass of ion-exchanged water was gradually added with continued stirring to disperse the isocyanate-terminated prepolymer in water. This prepared an aqueous dispersion of the isocyanate-terminated prepolymer.

[0169] Next, an aqueous solution of a chain extender was prepared by adding 3.24 parts by mass of hydrazine monohydrate to 12.96 parts by mass of ion-exchanged water.

[0170] The chain extender aqueous solution was then added to the aqueous dispersion of the isocyanate-terminated prepolymer, with the equivalent ratio of the active hydrogen groups of the chain extender to the isocyanate groups of the isocyanate-terminated prepolymer (active hydrogen groups / isocyanate groups) being 0.95.

[0171] Next, acetonitrile was distilled off under reduced pressure at 50°C, and then ion-exchanged water was added to prepare a polyurethane dispersion (solid content 30% by mass).

[0172] Example 2 7, 9, Reference examples 8, 10~13 , and Comparative Examples 1 to 7 A polyurethane dispersion (solid content 30% by mass) was prepared based on the same procedure as in Example 1. However, the compounding recipe was changed according to Tables 1 and 2. In Comparative Example 1, the polyurethane dispersion (PUD) was not dispersed in water (PUD dispersion in Table 2 is indicated by "x"), so each evaluation could not be performed. , each reference example In each comparative example, the PUD dispersion was dispersed in water (in Tables 1 and 2, the PUD dispersion is indicated by "◯").

[0173] <Evaluation> [Acid value] The acid value was calculated from the ratio of the raw material components, and the results are shown in Tables 1 and 2.

[0174] [Tensile properties] Each Example , each reference example The polyurethane dispersions (PUDs) of each comparative example were applied to a polypropylene tray to a dry thickness of 200 μm, dried at room temperature (25°C) for one day, and then heated at 110°C for one hour to prepare samples for physical property measurement. Using a tension-compression testing machine (Model 205N, manufactured by Intesco) at 23°C and a tensile speed of 300 mm / min, tensile tests were performed to determine the elongation at break (%), breaking strength (MPa), and 100% modulus (Mo) (MPa). The results are shown in Tables 1 and 2.

[0175] (Preparation of test pieces (fabric)) The polyester fabric was cut into 30 mm x 210 mm pieces to prepare test pieces.

[0176] (Preparation of pretreatment agent) A pretreatment agent was prepared by mixing 15.0 parts by mass of acetic acid, 20.5 parts by mass of sodium acetate, and 64.5 parts by mass of ion-exchanged water.

[0177] (Preparation of Ink Composition) Each Example , each reference exampleAn ink composition was prepared by mixing 40.0 parts by mass of the polyurethane dispersion (solid content concentration 30% by mass) of each comparative example, 8.0 parts by mass of a colorant (Dystone X Color Blue MX, manufactured by Matsui Pigment Chemical Industry Co., Ltd., active ingredient 25% by mass), 20.0 parts by mass of ethylene glycol, and 32.0 parts by mass of ion-exchanged water.

[0178] (Preparation of blocked isocyanate aqueous dispersion) A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube was charged with 242.17 parts by mass of D-170N, 47.72 parts by mass of methoxy PEG-1000, and 133.33 parts by mass of MEK, and then the mixture was subjected to a urethane reaction at 80°C until the NCO concentration reached 11.4% by mass.

[0179] Next, this reaction liquid was cooled to 50°C, and 110.11 parts by mass of DMP was gradually added while cooling, taking care to avoid heat generation.

[0180] Next, the mixture was reacted at 50°C until absorption by isocyanate was no longer observed by FT-IR (Fourier transform infrared spectroscopy).

[0181] Next, this reaction liquid was cooled to 30° C., and 600 parts by mass of ion-exchanged water was gradually added with stirring to disperse the reaction liquid in water.

[0182] Next, MEK was distilled off under reduced pressure at 50° C., and the residue was adjusted to a total of 1000 parts by mass with ion-exchanged water to obtain a blocked isocyanate aqueous dispersion with a solid content concentration of 40%.

[0183] (Preparation of Overcoat Agent) An overcoat agent was prepared by mixing 7.5 parts by mass of a blocked isocyanate aqueous dispersion (solid content concentration: 40% by mass) and 92.5 parts by mass of ion-exchanged water.

[0184] (Production of printed items) 3.5 to 4.0 g of pretreatment agent was sprayed onto the cut fabric (test piece). Next, approximately 3 g of ink composition was sprayed onto the fabric. Next, approximately 3 g of overcoat agent was sprayed onto the fabric. Next, the fabric was heat-treated at 110°C for 25 minutes to obtain a printed product.

[0185] [Color development] The color development of the printed textile was visually observed. The color development was evaluated according to the following criteria. The results are shown in Tables 1 and 2. (standard) ◯: A film was formed on the fabric, with almost no unevenness. △: There was some discoloration and uneven coloring. ×: The dye penetrated into the fabric and the color was clearly lighter.

[0186] [Adhesion] The printed textiles obtained in the color development test were subjected to loads (scratching and stretching) and checked for lifting, cracking, and peeling of the coating film (dried ink composition). Adhesion was evaluated according to the following criteria. The results are shown in Tables 1 and 2. (standard) Good: No lifting, cracking or peeling occurred even when a load was applied. △: Floating, cracking, or peeling occurred due to the load. ×: Lifting, cracking, or peeling occurred.

[0187] [Shrinkage resistance] The shrinkage resistance of the printed textile was visually observed. The shrinkage resistance was evaluated according to the following criteria. The results are shown in Tables 1 and 2. (standard) O: There was no contraction. △: There was slight shrinkage. ×: Shrinkage occurred.

[0188] [Texture] The printed fabric was observed with a touch. The texture was evaluated according to the following criteria. The results are shown in Tables 1 and 2. (standard) 〇: It was flexible. △: Somewhat hard. ×: It was hard.

[0189] [Washing fastness] The printed fabric was washed 10 times under the following conditions: (Washing conditions) Washing: AW-F42S (pulsator washing machine, manufactured by Toshiba) standard mode Detergent: Synthetic laundry detergent Bold Fresh Pure Clean (Procter & Gamble Japan) at the stated concentration (approximately 43g of detergent per 45L of water) Drying: ED-50 (Tumbler Dryer, manufactured by Toshiba) Standard mode

[0190] Thereafter, the printed item was subjected to loads (scratching and stretching) and the coating film (dried ink composition) was checked for lifting, cracking, and peeling. The washing fastness was evaluated according to the following criteria. The results are shown in Tables 1 and 2. (standard) Good: No lifting, cracking or peeling occurred even when a load was applied. △: Floating, cracking, or peeling occurred due to the load. ×: Lifting, cracking, or peeling occurred.

[0191] [Table 1]

[0192] [Table 2]

Claims

1. A polyurethane dispersion obtained by dispersing a polyurethane resin in water, the polyurethane resin is a reaction product of an isocyanate group-terminated prepolymer and a chain extender, The isocyanate group-terminated prepolymer comprises a polyisocyanate component and a reaction product of a macropolyol, an anionic group-containing active hydrogen compound, and a polyol component including a polyoxyethylene-containing monool; The acid value of the polyurethane resin is 4.0 mgKOH / g or more and 10.0 mgKOH / g or less, the polyoxyethylene content of the polyoxyethylene-containing monool in the polyurethane resin is 2.5% by mass or more and 7.5% by mass or less; the polyisocyanate component is 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane or a mixture thereof; Polyurethane dispersion.

2. 2. The polyurethane dispersion according to claim 1, wherein the elongation at break of the dried product of the polyurethane dispersion is 550% or more and 1200% or less.

3. 3. The polyurethane dispersion according to claim 1, wherein the macropolyol comprises a polyether polyol.

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