Polyurethane dispersion and ink composition

Abstract

This polyurethane dispersion is obtained by dispersing a polyurethane resin in water. The polyurethane resin is a reaction product between a chain extender and an isocyanate group-terminated prepolymer. The isocyanate group-terminated prepolymer is a reaction product between a polyisocyanate component and a polyol component including a macropolyol and a hydrophilic group-containing active hydrogen compound. The macropolyol is an aromatic ring-containing polyester polyol. The polyurethane resin has an acid value of 7.0-14.0 mgKOH / g. The total of the urea group concentration and the urethane group concentration in the polyurethane resin is 20.0 mass% or less. The aromatic ring concentration in the polyurethane resin is 5.0-15.0 mass%.

Description

[Technical Field]

[0001] The present invention relates to polyurethane dispersions and ink compositions. [Background technology]

[0002] It has been known to use an inkjet method to eject droplets of an ink composition from a nozzle to print on fabric. The ink composition contains, for example, a colorant and a resin for dispersing the colorant. When the colorant is a pigment, the ink composition also contains a binder resin for physically fixing the pigment to the fabric.

[0003] As such a resin, for example, a pigment dispersant containing a urethane resin obtained by reacting a polyester polyol obtained by reacting isophthalic acid and a polyol, a polyol having a hydrophilic group, and a polyisocyanate has been proposed (see, for example, Example 2 of Patent Document 1 below).

[0004] Also proposed is an aqueous pigment composition containing, as a binder resin, a polyester polyol obtained by reacting isophthalic acid with a polyol, a urethane resin obtained by reacting a polyol having a hydrophilic group with a polyisocyanate (see, for example, Example 2 of Patent Document 1 below). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-174876 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-163678 Summary of the Invention [Problem to be solved by the invention]

[0006] 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.

[0007] 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.

[0008] Furthermore, if the resin attached to the surface of the fabric does not conform to the deformation of the fabric, the resin may peel off. Therefore, the resin is required to have the ability to conform to the deformation of the fabric.

[0009] In particular, the pigment dispersant of Patent Document 1 and the aqueous pigment composition of Patent Document 2 have a high concentration of aromatic rings in the polyurethane resin, which increases the cohesive force and hardens the resin, resulting in a problem of reduced ability to follow deformation of the fabric.

[0010] The present invention provides a polyurethane dispersion that, when used for textile printing, has excellent color development and adhesion, and is also excellent in adaptability to deformation of the fabric, and an ink composition containing the polyurethane dispersion. [Means for solving the problem]

[0011] The present invention [1] is a polyurethane dispersion in which a polyurethane resin is dispersed in water, wherein the polyurethane resin is 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 and a hydrophilic-group-containing active hydrogen compound, the macropolyol contains an aromatic ring-containing polyester polyol, the acid value of the polyurethane resin is 7.0 mgKOH / g or more and 14.0 mgKOH / g or less, the sum of the urethane group concentration and the urea group concentration of the polyurethane resin is 20.0 mass% or less, and the aromatic ring concentration in the polyurethane resin is 5.0 mass% or more and 15.0 mass% or less.

[0012] The present invention [2] includes a polyurethane dispersion in which the total concentration of urethane groups and urea groups in the polyurethane resin is 10.0 mass % or less.

[0013] The present invention [3] includes the polyurethane dispersion according to the above [1] or [2], in which the polyisocyanate component includes an alicyclic polyisocyanate.

[0014] The present invention [4] includes the polyurethane dispersion according to any one of the above [1] to [3], in which the hydrophilic group-containing active hydrogen compound is an anionic group-containing active hydrogen compound.

[0015] The present invention [5] comprises the polyurethane dispersion according to any one of the above [1] to [4], in which the aromatic ring-containing polyester polyol is a reaction product of a polyhydric alcohol and a polybasic acid, and the polybasic acid includes an aromatic ring-containing polybasic acid and an aromatic ring-free polybasic acid.

[0016] The present invention [6] includes the polyurethane dispersion according to any one of the above [1] to [5], in which the aromatic ring-containing polybasic acid is isophthalic acid.

[0017] The present invention [7] includes an ink composition containing the polyurethane dispersion according to any one of the above [1] to [6].

[0018] The present invention [8] includes the ink composition described in [7] above for printing fabrics or leather. [Effects of the Invention]

[0019] In the polyurethane dispersion of the present invention, the polyurethane resin has an acid value of 7.0 mgKOH / g or more and 14.0 mgKOH / g or less. When the acid value is 7.0 mgKOH / g or more, excellent color development is achieved when textile printing is performed on fabrics. When the acid value is 14.0 mgKOH / g or less, excellent adhesion is achieved when textile printing is performed on fabrics.

[0020] In this polyurethane dispersion, the total concentration of urethane groups and urea groups in the polyurethane resin is 20.0% by mass or less. When the total concentration of urethane groups and urea groups is 20.0% by mass or less, the dispersion exhibits excellent conformability to deformation of the fabric when the fabric is printed.

[0021] In this polyurethane dispersion, the concentration of aromatic rings in the polyurethane resin is 5.0% by mass or more and 15.0% by mass or less. When the aromatic ring concentration is 5.0% by mass or more, the color development and adhesion are excellent. When the aromatic ring concentration is 15.0% by mass or less, the conformability to deformation of the fabric is excellent.

[0022] The ink composition of the present invention contains the polyurethane dispersion of the present invention, and therefore exhibits excellent adhesion and followability when used to print fabrics. [Brief explanation of the drawings]

[0023] [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

[0024] The polyurethane dispersion is prepared by dispersing a polyurethane resin in water.

[0025] The polyurethane resin is a reaction product of an isocyanate-terminated prepolymer and a chain extender.

[0026] <Isocyanate-terminated prepolymer> The isocyanate-terminated prepolymer is a reaction product of a polyisocyanate component and a polyol component containing a macropolyol and a hydrophilic group-containing active hydrogen compound.

[0027] [Polyisocyanate component] The polyisocyanate component includes polyisocyanate and / or a derivative of polyisocyanate.

[0028] (Polyisocyanate) Examples of polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates.

[0029] 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. Preferred examples of aliphatic polyisocyanates include 1,6-HDI and 1,5-PDI.

[0030] 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 IPDI, 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. 12 Examples include MDI and H6XDI (preferably 1,3-H6XDI).

[0031] 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.

[0032] 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. XDI is preferably used as the araliphatic polyisocyanate.

[0033] The polyisocyanate is preferably an aliphatic polyisocyanate, an alicyclic polyisocyanate, or an araliphatic polyisocyanate. From the viewpoint of improving the filterability of the polyurethane dispersion, the polyisocyanate is more preferably an alicyclic polyisocyanate.

[0034] The polyisocyanates can be used alone or in combination of two or more kinds.

[0035] (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.

[0036] The polyisocyanate derivatives can be used alone or in combination of two or more kinds.

[0037] The polyisocyanate component preferably does not contain a derivative of polyisocyanate and is composed of polyisocyanate, and more preferably is composed of alicyclic polyisocyanate.

[0038] [Polyol component] The polyol component includes a macropolyol and a hydrophilic group-containing active hydrogen compound.

[0039] (macropolyol) The macropolyol includes an aromatic ring-containing polyester polyol.

[0040] The aromatic ring-containing polyester polyol is a compound having 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.

[0041] The average number of functional groups of the aromatic ring-containing polyester polyol is not particularly limited, but is preferably 2.

[0042] The aromatic ring-containing polyester polyol has an aromatic ring. Specifically, the aromatic ring-containing polyester polyol has an aromatic ring derived from an aromatic ring-containing polyhydric alcohol (described later) and / or an aromatic ring-containing polybasic acid (described later).

[0043] The aromatic ring-containing polyester polyol is a reaction product of a polyhydric alcohol and a polybasic acid. That is, the aromatic ring-containing polyester polyol is obtained by reacting a polyhydric alcohol with a polybasic acid under known conditions. That is, the aromatic ring-containing polyester polyol is a condensation polymer obtained by condensation polymerization, and is distinguished from a ring-opening polymer (polycaprolactone).

[0044] Examples of polyhydric alcohols include aromatic ring-containing polyhydric alcohols and non-aromatic ring-containing polyhydric alcohols.

[0045] Examples of aromatic ring-containing polyhydric alcohols include aromatic ring-containing diols, such as bisphenol A, bisphenol S, and bisphenol F.

[0046] Examples of non-aromatic ring polyhydric alcohols include dihydric alcohols and trihydric alcohols.

[0047] Examples of dihydric alcohols include C2-C20 alkanediols, alicyclic diols, C4-C10 ether diols, and heterocyclic diols. Examples of C2-C20 alkanediols include 1,2-ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,2-trimethylpentanediol, 3,3-dimethylolheptane, and 2,6-dimethyl-1-octene-3,8-diol. Examples of alicyclic diols include 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, and hydrogenated bisphenol A. Examples of C4-10 ether diols include diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of heterocyclic diols include isosorbide (1,4:3,6-dianhydroglucitol). Examples of trihydric alcohols include glycerin, trimethylolpropane, and triisopropanolamine.

[0048] The non-aromatic ring polyhydric alcohol is preferably a dihydric alcohol. More preferably, the non-aromatic ring polyhydric alcohol is an alkanediol having 2 to 6 carbon atoms. More preferably, the non-aromatic ring polyhydric alcohol is 1,2-ethylene glycol, neopentyl glycol, and 3-methyl-1,5-pentanediol.

[0049] The polyhydric alcohols can be used alone or in combination of two or more. As the polyhydric alcohol, preferably, 3-methyl-1,5-pentanediol is used alone, or 1,2-ethylene glycol and neopentyl glycol are used in combination.

[0050] The polyhydric alcohol preferably does not contain an aromatic ring-containing polyhydric alcohol, and is composed of a non-aromatic ring-containing polyhydric alcohol.

[0051] Examples of polybasic acids include aromatic ring-containing polybasic acids and non-aromatic ring-containing polybasic acids.

[0052] Examples of aromatic ring-containing polybasic acids include aromatic dicarboxylic acids. Examples of aromatic dicarboxylic acids include phthalic acid (orthophthalic acid, isophthalic acid, terephthalic acid), toluene dicarboxylic acid, and naphthalenedicarboxylic acid. Examples of aromatic ring-containing polybasic acids include phthalic acid. Examples of aromatic ring-containing polybasic acids include isophthalic acid and terephthalic acid. Examples of aromatic ring-containing polybasic acids include isophthalic acid, which is more preferred from the viewpoint of improving texture.

[0053] Examples of non-aromatic ring polybasic acids include saturated aliphatic dicarboxylic acids (C11-13), unsaturated aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, other carboxylic acids, and acid anhydrides derived from these carboxylic acids. Examples of saturated aliphatic dicarboxylic acids (C11-13) include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, 3-methyl-3-ethylglutaric acid, azelaic acid, and sebacic acid. Examples of unsaturated aliphatic dicarboxylic acids include maleic acid, fumaric acid, and itaconic acid. Examples of alicyclic dicarboxylic acids include hexahydrophthalic acid. Examples of other carboxylic acids include dimer acid, hydrogenated dimer acid, and HET acid. Examples of acid anhydrides include oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, 2-alkyl (C12 to C18) succinic anhydride, tetrahydrophthalic anhydride, and trimellitic anhydride.

[0054] As the non-aromatic ring polybasic acid, preferably, saturated aliphatic dicarboxylic acids (C11-13) are used. As the non-aromatic ring polybasic acid, more preferably, adipic acid and sebacic acid are used. As the non-aromatic ring polybasic acid, even more preferably, sebacic acid is used.

[0055] The polybasic acids can be used alone or in combination of two or more kinds.

[0056] From the viewpoint of improving adhesion, the polybasic acid preferably includes an aromatic ring-containing polybasic acid and a non-aromatic ring-containing polybasic acid, and more preferably includes an aromatic ring-containing polybasic acid and a non-aromatic ring-containing polybasic acid.

[0057] As described above, the aromatic ring-containing polyester polyol can be obtained by reacting a polyhydric alcohol with a polybasic acid, in which at least one of the polyhydric alcohol and the polybasic acid is selected to have an aromatic ring.

[0058] Specifically, if the polyhydric alcohol is an aromatic ring-containing polyhydric alcohol, the polybasic acid includes an aromatic ring-containing polybasic acid and / or a non-aromatic ring-containing polybasic acid. Furthermore, if the polyhydric alcohol is a non-aromatic ring-containing polyhydric alcohol, the polybasic acid includes at least an aromatic ring-containing polybasic acid. On the other hand, if the polybasic acid is an aromatic ring-containing polybasic acid, the polyhydric alcohol includes an aromatic ring-containing polyhydric alcohol and / or a non-aromatic ring-containing polyhydric alcohol. Furthermore, if the polybasic acid is a non-aromatic ring-containing polybasic acid, the polyhydric alcohol includes at least an aromatic ring-containing polyhydric alcohol.

[0059] The aromatic ring-containing polyester polyol is preferably a reaction product of a non-aromatic ring-containing polyhydric alcohol and an aromatic ring-containing polybasic acid.

[0060] The aromatic ring-containing polyester polyols can be used alone or in combination of two or more kinds.

[0061] The macropolyol may also contain other macropolyols.

[0062] The other macropolyol is a compound having a hydroxyl group at the molecular terminal 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.

[0063] The average functionality of the other macropolyol is not particularly limited, but is preferably 2.

[0064] Other macropolyols are macropolyols other than the aromatic ring-containing polyester polyols. Examples of other macropolyols include aromatic ring-free polyester polyols, polyether polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. Preferred examples of other macropolyols include polyether polyols and polycarbonate polyols.

[0065] Examples of polyether polyols include polyoxyalkylene (having 2 to 3 carbon atoms) polyols and polytetramethylene ether polyols.

[0066] 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.

[0067] 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.

[0068] Specific examples of polyoxyalkylene (carbon number 2 to 3) polyols include polyoxyethylene glycol, polyoxypropylene glycol, and random and / or block copolymers of propylene oxide and ethylene oxide.

[0069] Furthermore, the polyoxyalkylene (carbon number 2 to 3) polyol also includes polytrimethylene ether glycol.

[0070] An example of polytrimethylene ether glycol is a glycol obtained by polycondensation reaction of 1,3-propanediol derived from plant components.

[0071] 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 obtained by copolymerizing polymerization units of tetrahydrofuran or the like with alkyl-substituted tetrahydrofuran or the above-mentioned dihydric alcohols.

[0072] As the polyether polyol, preferably, polytetramethylene ether polyol is used, and more preferably, polytetramethylene ether glycol is used.

[0073] Examples of polycarbonate polyols include polycarbonate diols, such as a ring-opening polymer of ethylene carbonate using a low-molecular-weight polyol (preferably a dihydric alcohol) as an initiator, as described below, and polycarbonate diols obtained by copolymerizing a ring-opening polymer with a dihydric alcohol (e.g., 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, and 1,6-hexanediol).

[0074] The other macropolyols can be used alone or in combination of two or more kinds.

[0075] The blending ratio of the other macropolyols is, for example, 20 parts by mass or more, preferably 40 parts by mass or more, and for example, 60 parts by mass or less, preferably 45 parts by mass or less, per 100 parts by mass of the total amount of macropolyols.

[0076] (Hydrophilic group-containing active hydrogen compound) The hydrophilic group-containing active hydrogen compound is a compound containing a hydrophilic group and two or more active hydrogen groups, such as hydroxyl groups and amino groups.

[0077] Examples of the hydrophilic group include a nonionic group and an ionic group. More specific examples of the hydrophilic group-containing active hydrogen compound include an active hydrogen group-containing compound containing a nonionic group and an active hydrogen group-containing compound containing an ionic group.

[0078] The active hydrogen group-containing compound containing a nonionic group is a compound having one or more nonionic groups and two or more active hydrogen groups.The nonionic group can be, for example, a polyoxyethylene group.The active hydrogen group-containing compound containing a nonionic group can be, for example, polyoxyethylene glycol, one-end-blocked polyoxyethylene glycol, and polyol containing a polyoxyethylene side chain.

[0079] Examples of active hydrogen group-containing compounds containing an ionic group include active hydrogen group-containing compounds containing an anionic group and active hydrogen group-containing compounds containing a cationic group.

[0080] The active hydrogen group-containing compound containing an anionic group is a compound having both one or more anionic groups and two or more active hydrogen groups. Examples of the anionic group include a carboxy group (carboxylic acid group) and a sulfo group (sulfonic acid group), and preferably a carboxy group. In addition, in the active hydrogen group-containing compound containing an anionic group, examples of the active hydrogen group include a hydroxyl group and an amino group, and preferably a hydroxyl group. That is, the active hydrogen group-containing compound containing an anionic group is preferably an organic compound having both a carboxy group and two hydroxyl groups.

[0081] Examples of organic compounds having both a carboxy group and two hydroxyl groups include carboxy group-containing polyols. Examples of carboxy group-containing polyols include polyhydroxyalkanoic acids. Examples of polyhydroxyalkanoic acids include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid (also known as dimethylolpropionic acid), 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid. A preferred example of an organic compound having both a carboxy group and two hydroxyl groups is 2,2-dimethylolpropionic acid.

[0082] The active hydrogen group-containing compound containing a cationic group is a compound that has one or more cationic groups and two or more active hydrogen groups. Examples of the cationic group include a tertiary amino group (a tertiary amine that can form a tertiary ammonium salt). In addition, in the active hydrogen group-containing compound containing a cationic group, examples of the active hydrogen group include a hydroxyl group and an amino group, and preferably a hydroxyl group. That is, the active hydrogen group-containing compound containing a cationic group is preferably an organic compound that has both a tertiary amino group and two hydroxyl groups.

[0083] Examples of organic compounds having both a tertiary amino group and two hydroxyl groups include N-alkyldialkanolamines, such as N-methyldiethanolamine, N-propyldiethanolamine, N-butyldiethanolamine, and N-methyldipropanolamine.

[0084] The hydrophilic group-containing active hydrogen compound is preferably an active hydrogen group-containing compound containing an ionic group, and more preferably an active hydrogen group-containing compound containing an anionic group, from the viewpoint of adjusting the acid value of the polyurethane resin described below to a predetermined range.

[0085] The hydrophilic group-containing active hydrogen compounds can be used alone or in combination of two or more.

[0086] The blending ratio of the hydrophilic group-containing active hydrogen compound relative to 100 parts by mass of the total amount of the polyol components is, for example, 1 part by mass or more, preferably 2 parts by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass or less.

[0087] In particular, when the hydrophilic group-containing active hydrogen compound is an active hydrogen group-containing compound containing an anionic group (preferably a carboxy group), by setting the blending ratio within the above range, the acid value of the polyurethane resin described below can be set within a predetermined range.

[0088] (Low molecular weight polyol) The polyol component may also contain a low molecular weight polyol (a low molecular weight polyol excluding a hydrophilic group-containing active hydrogen compound).

[0089] The low-molecular-weight polyol is a compound having a number-average molecular weight of 40 or more and less than 400, preferably 300 or less.

[0090] The number of functional groups of the low molecular weight polyol is not particularly limited, but is preferably 2.

[0091] Examples of low molecular weight polyols include diols having 2 to 6 carbon atoms and other low molecular weight polyols (excluding diols having 2 to 6 carbon atoms).

[0092] The diol having 2 to 6 carbon atoms has a number average molecular weight of 40 or more but less than 400, preferably 300 or less, and is a compound having 2 to 6 carbon atoms and two hydroxyl groups. Examples of the diol include an alkanediol having 2 to 6 carbon atoms (an alkylene glycol having 2 to 6 carbon atoms), an etherdiol having 2 to 6 carbon atoms, and an alkenediol having 2 to 6 carbon atoms.

[0093] 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, neopentyl glycol, 3-methyl-1,5-pentanediol, and 1,3- or 1,4-cyclohexanediol.

[0094] Examples of the ether diol having 2 to 6 carbon atoms include diethylene glycol, triethylene glycol, and dipropylene glycol, and preferably triethylene glycol. Examples of the ether diol having 2 to 6 carbon atoms include triethylene glycol.

[0095] An example of the alkenediol having 2 to 6 carbon atoms is 1,4-dihydroxy-2-butene.

[0096] The other low-molecular-weight polyols are compounds having a number-average molecular weight of 40 or more but less than 400, preferably 300 or less, and having two or more hydroxyl groups in one molecule, such as diols (dihydric alcohols) having 7 or more carbon atoms, and trihydric or higher low-molecular-weight polyols.

[0097] The diol (dihydric alcohol) having 7 or more carbon atoms is a compound having a number average molecular weight of 40 or more but less than 400, preferably 300 or less, and having two hydroxyl groups per molecule and having 7 or more carbon atoms, and examples thereof include alkane-1,2-diols having 7 to 20 carbon atoms, 2,6-dimethyl-1-octene-3,8-diol, 1,3- or 1,4-cyclohexanedimethanol, and mixtures thereof, hydrogenated bisphenol A, and bisphenol A.

[0098] Examples of diols (dihydric alcohols) having 7 or more carbon atoms include dihydric polyalkylene oxides having a number-average molecular weight of less than 400, preferably 300 or less. Such polyalkylene oxides can be obtained, for example, by addition reaction of alkylene oxides such as ethylene oxide and / or propylene oxide with the above-mentioned dihydric alcohols as an initiator, to give polyethylene glycols (polyoxyethylene ether glycols), polypropylene glycols (polyoxypropylene ether glycols), polyethylenepolypropylene glycols (random or block copolymers), etc. Further examples include polytetramethylene ether glycols having a number-average molecular weight of less than 400, preferably 300 or less, obtained by ring-opening polymerization of tetrahydrofuran, for example.

[0099] The trihydric or higher low-molecular-weight polyol has a number-average molecular weight of 40 or more but less than 400, preferably 300 or less, and is a compound having three or more hydroxyl groups per molecule. Examples of the trihydric alcohol include trihydric alcohol (low-molecular-weight triol), tetrahydric alcohol, pentahydric alcohol, hexahydric alcohol, heptahydric alcohol, and octahydric alcohol. Examples of the trihydric alcohol include glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6-hexanetriol, trimethylolpropane, and 2,2-bis(hydroxymethyl)-3-butanol. Examples of the tetrahydric alcohol include tetramethylolmethane (pentaerythritol) and diglycerin. Examples of the pentahydric alcohol include xylitol. Examples of hexahydric alcohols include sorbitol, mannitol, allitol, iditol, dulcitol, altritol, inositol, and dipentaerythritol. Examples of heptahydric alcohols include perseitol. Examples of octahydric alcohols include sucrose.

[0100] Examples of the low molecular weight trivalent or higher polyols include trivalent or higher polyalkylene oxides having a number average molecular weight of 40 or more but less than 400, preferably 300 or less. Such polyalkylene oxides can be obtained as polyethylene polyols, polypropylene polyols, and polyethylenepolypropylene polyols (random or block copolymers) by addition reaction of alkylene oxides such as ethylene oxide and / or propylene oxide with the above-mentioned trivalent or higher low-molecular-weight polyols or known polyamines as initiators.

[0101] The low molecular weight polyols can be used alone or in combination of two or more kinds.

[0102] The mixing ratio of the low-molecular-weight polyol relative to 100 parts by mass of the total amount of the polyol components is, for example, 1 part by mass or more, preferably 5 parts by mass or more, and for example, 15 parts by mass or less.

[0103] The polyol component preferably does not contain a low-molecular-weight polyol, and is composed of a macropolyol and a hydrophilic group-containing active hydrogen compound.

[0104] [Preparation of isocyanate-terminated prepolymer] The isocyanate-terminated prepolymer can be obtained by reacting a polyisocyanate component with a polyol component.

[0105] 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.

[0106] In solution polymerization, for example, the above components are mixed in an organic solvent (solvent) under a nitrogen atmosphere and reacted.

[0107] In this reaction, the equivalent ratio (isocyanate group / active hydrogen group) of the isocyanate group in the polyisocyanate component to the active hydrogen groups (hydroxyl groups and / or amino groups) in the polyol component exceeds 1, for example, 1.2 or more, preferably 1.3 or more, for example, 3.0 or less, preferably 2.5 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.

[0108] As for reaction conditions, the reaction temperature is, for example, 20° C. or higher and, for example, 110° C. or lower, and the reaction time is, for example, 1 hour or higher and, for example, 20 hours or lower.

[0109] 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.

[0110] In the polymerization, a reaction catalyst (for example, an amine-based, tin-based, or lead-based catalyst) may be added as needed.

[0111] In the above reaction, unreacted polyisocyanate components and / or unreacted polyol components can be removed by known methods such as distillation or extraction.

[0112] This produces an isocyanate-terminated prepolymer, which is a reaction product of the polyisocyanate component and the polyol component.

[0113] 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.

[0114] The isocyanate-terminated prepolymer is a polyurethane prepolymer having at least one (preferably multiple, more preferably two) free isocyanate group at its molecular end. 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, and for example, 5.0% by mass or less, preferably 4.0% by mass or less.

[0115] Furthermore, when the reaction product contains an ionic group, it is preferable to neutralize it by adding a neutralizing agent to form a salt of the ionic group.

[0116] When the ionic group is an anionic group, a conventional base is used as the neutralizing agent. Examples of conventional bases include ammonia, C1-20 amine compounds, and alkali metal hydroxides (e.g., sodium hydroxide, potassium hydroxide, and lithium hydroxide). Examples of C1-20 amine compounds include primary amines such as monomethylamine, monoethylamine, monobutylamine, and monoethanolamine; secondary amines such as dimethylamine, diethylamine, dibutylamine, diethanolamine, diisopropanolamine, and methylpropanolamine; and tertiary amines such as trimethylamine, triethylamine, dimethylethylamine, dimethylmonoethanolamine, triisopropanolamine, and triethanolamine. When the ionic group is a cationic group, a conventional acid is used. Examples of conventional acids include mono- or dicarboxylic acids having 1 to 7 carbon atoms, sulfonic acids having 1 to 20 carbon atoms, and inorganic acids. Examples of mono- or dicarboxylic acids having 1 to 7 carbon atoms include formic acid, acetic acid, propionic acid, oxalic acid, and succinic acid. Examples of sulfonic acids having 1 to 20 carbon atoms include methanesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, trifluoromethanesulfonic acid, and p-toluenesulfonic acid. Inorganic acids include, for example, hydrochloric acid, sulfuric acid, and nitric acid.

[0117] In particular, when the ionic group is an anionic group (preferably a carboxy group), the neutralizing agent is added in a proportion of 0.6 equivalents or more, preferably 0.8 equivalents or more, per equivalent of the anionic group, and for example, 1.2 equivalents or less, preferably 1.1 equivalents or less.

[0118] <Chain extender> Examples of the chain extender include the above-mentioned low molecular weight polyols and amino group-containing compounds.

[0119] Examples of the amino group-containing compound include aromatic polyamines, araliphatic polyamines, alicyclic polyamines, aliphatic polyamines, amino alcohols, polyoxyethylene group-containing polyamines, alkoxysilyl compounds having a primary amino group or a primary amino group and a secondary amino group, and hydrazine or a derivative thereof.

[0120] Examples of aromatic polyamines include 4,4'-diphenylmethanediamine and tolylenediamine.

[0121] Araliphatic polyamines include, for example, 1,3- or 1,4-xylylenediamine or mixtures thereof.

[0122] 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.

[0123] Examples of aliphatic polyamines include ethylenediamine, propylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and 1,3-diaminopentane.

[0124] 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).

[0125] Examples of polyoxyethylene group-containing polyamines include polyoxyalkylene ether diamines such as polyoxyethylene ether diamine, more specifically PEG#1000 diamine manufactured by NOF Corporation, and Jeffamine ED-2003, EDR-148, and XTJ-512 manufactured by Huntsman.

[0126] 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).

[0127] Examples of hydrazine or its derivatives include hydrazine (including hydrazine monohydrate), succinic acid dihydrazide, sebacic acid dihydrazide, and adipic acid dihydrazide.Preferably, hydrazine or its derivatives is hydrazine monohydrate.

[0128] The chain extender preferably includes hydrazine or a derivative thereof.

[0129] The chain extender can also be prepared, for example, as an aqueous solution (aqueous chain extender solution).

[0130] The chain extenders can be used alone or in combination of two or more.

[0131] <Preparation of polyurethane resin> The polyurethane resin is obtained by reacting an isocyanate group-terminated prepolymer with a chain extender.

[0132] Specifically, an isocyanate group-terminated prepolymer and a chain extender are reacted in water, for example, to obtain a polyurethane resin (polyurethane dispersion).

[0133] To react the isocyanate group-terminated prepolymer with the chain extender in water, for example, the isocyanate group-terminated prepolymer is first added to water to disperse the isocyanate group-terminated prepolymer in water, and then a chain extender is added thereto to extend the chain of the isocyanate group-terminated prepolymer with the chain extender.

[0134] 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.

[0135] 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 (amino groups and hydroxyl groups) of the chain extender to the isocyanate groups of the isocyanate group-terminated prepolymer is, for example, 0.8 or more and 1.2 or less.

[0136] After the dropwise addition of the chain extender is completed, the reaction is continued with stirring, for example, at room temperature, to complete the reaction. The reaction time until the reaction is completed is, for example, 0.1 hours or more and, for example, 10 hours or less.

[0137] 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 can be added thereto to extend the chains of the isocyanate group-terminated prepolymer with the chain extender.

[0138] 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.

[0139] 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).

[0140] The acid value of the polyurethane resin is 7.0 mgKOH / g or more, preferably 8.0 mgKOH / g or more, more preferably 9.0 mgKOH / g or more, and 14.0 mgKOH / g or less, preferably 13.0 mgKOH / g or less, more preferably 10.0 mgKOH / g or less.

[0141] The acid value can be adjusted to fall within the above range, for example, by adjusting the blending ratio of the active hydrogen group-containing compound that contains an anionic group (preferably a carboxy group).

[0142] If the acid value is equal to or greater than the lower limit, color development is improved when a fabric (described later) is printed (that is, color density is increased on the surface of the fabric (described later)).

[0143] On the other hand, if the acid value is less than the lower limit, color development will be reduced when printing fabric (described later).

[0144] Furthermore, if the acid value is equal to or less than the upper limit, adhesion is improved when printing fabrics (described later).

[0145] On the other hand, if the acid value exceeds the upper limit, adhesion decreases when printing fabrics (described later).

[0146] The acid value can be calculated from the ratio of the components charged.

[0147] The total concentration of urethane groups and urea groups in the polyurethane resin is 20.0% by mass or less, preferably 15.0% by mass or less, more preferably 12.0% by mass or less, and from the viewpoint of improving texture, even more preferably 10.0% by mass or less, and for example, 5.0% by mass or more, preferably 7.0% by mass or more, more preferably 7.5% by mass or more.

[0148] If the total of the urethane group concentration and the urea group concentration is equal to or less than the upper limit, when a fabric (described later) is printed, the ability to follow deformation of the fabric (described later) and the feel are improved.

[0149] On the other hand, if the total of the urethane group concentration and the urea group concentration exceeds the upper limit, when a fabric (described later) is printed, the ability to follow deformation of the fabric (described later) and the feel are reduced.

[0150] Furthermore, if the total of the urethane group concentration and the urea group concentration is equal to or greater than the above lower limit, when a fabric (described later) is printed, the color development, adhesion, and suppression of color transfer (for example, the transfer of the color of a printed fabric to another fabric during washing) are improved.

[0151] The total of the urethane group concentration and the urea group concentration can be calculated from the charge ratio of the raw material components.

[0152] The aromatic ring concentration in the polyurethane resin is 5.0% by mass or more, preferably 7.0% by mass or more, more preferably 9.0% by mass or more, and even more preferably 10.0% by mass or more, and is 15.0% by mass or less, preferably 12.0% by mass or less, and more preferably 11.0% by mass or less.

[0153] When the aromatic ring concentration is equal to or higher than the lower limit, excellent color development and adhesion are achieved when printing fabric (described later).

[0154] On the other hand, if the aromatic ring concentration is less than the lower limit, color development and adhesion will be reduced when printing on a fabric (described later).

[0155] Furthermore, if the aromatic ring concentration is equal to or less than the upper limit, when a fabric (described later) is printed, the ink composition has excellent conformability to deformation of the fabric (described later).

[0156] On the other hand, if the aromatic ring concentration exceeds the upper limit, in the case of printing a fabric (described later), the ability to follow deformation of the fabric (described later) decreases.

[0157] The aromatic ring concentration can be calculated from the charging ratio of the raw material components.

[0158] 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.

[0159] <Use of polyurethane dispersion> The polyurethane dispersion is preferably used in the ink composition as a resin for dispersing the colorant, and when the colorant is a pigment, as a binder resin for physically fixing the pigment to the fabric.

[0160] The ink composition is a raw material for printing fabrics or leather. That is, the ink composition is for printing fabrics or leather.

[0161] 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.

[0162] When the polyurethane dispersion is used as a resin for dispersing a colorant in an ink composition, the ink composition contains the colorant and the polyurethane dispersion.

[0163] The coloring material is not particularly limited, and known coloring materials can be used.

[0164] The polyurethane dispersion is a component that disperses the coloring material in the ink composition.

[0165] The mixing ratio of the polyurethane dispersion relative to 100 parts by mass of the colorant is, for example, 500 parts by mass or more, and for example, 1000 parts by mass or less, preferably 700 parts by mass or less.

[0166] The ink composition is then prepared by mixing the colorant and the polyurethane dispersion.

[0167] In addition, if necessary, known additives (for example, humectants, penetrants, chelating agents, preservatives, and pH adjusters) can also be blended into the ink composition. That is, the ink composition contains known additives as needed. The humectants, penetrants, chelating agents, preservatives, and pH adjusters described in JP 2021-165353 A can be used.

[0168] The ink composition can also be diluted with water and / or an organic solvent (eg, ethylene glycol).

[0169] Furthermore, when the polyurethane dispersion is used as a binder resin in the ink composition for physically fixing the pigment to the fabric, the ink composition contains the pigment, the polyurethane dispersion, and, if necessary, a pigment dispersion liquid.

[0170] The pigment is not particularly limited, and any known pigment can be used.

[0171] The polyurethane dispersion is a binder resin in the ink composition that physically fixes the pigment to the fabric.

[0172] The pigment dispersion is a dispersant that disperses the pigment.

[0173] The ink composition is prepared by mixing the pigment, the polyurethane dispersion, and, if necessary, a pigment dispersion liquid.

[0174] The ink composition may also contain the above-mentioned additives and may be diluted with water and / or an organic solvent (for example, ethylene glycol).

[0175] Next, a method for printing fabric using this ink composition will be described in detail.

[0176] 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.

[0177] 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.

[0178] To pretreat the fabric, the fabric is treated with a pretreatment agent.

[0179] Examples of pretreatment agents include organic acids and their salts (for example, formic acid, sodium formate, acetic acid, and sodium acetate), polyvalent metal salts, and cationic compounds. The pretreatment agent is preferably an organic acid, more preferably acetic acid or sodium acetate, and can also be prepared as an aqueous solution.

[0180] 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.

[0181] 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.

[0182] Next, the fabric (the fabric to which the ink composition has been applied) is heated.

[0183] The heating temperature is, for example, 80° C. or higher, preferably 100° C. or higher, and for example, 170° 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 30 minutes or shorter, more preferably 15 minutes or shorter.

[0184] This results in printing of the fabric (i.e., obtaining a printed product).

[0185] Since the ink composition contains the polyurethane dispersion described above, it is possible to produce a printed item that has excellent color development and adhesion, and also has excellent adaptability to deformation of the fabric.

[0186] <Action and effect> The polyurethane dispersion has a predetermined acid value, a predetermined sum of a urethane group concentration and a urea group concentration, and a predetermined aromatic ring concentration, so that when the polyurethane dispersion is used for textile printing, it has excellent color development and adhesion, and excellent adaptability to deformation of the fabric.

[0187] On the other hand, color development and adhesion have a trade-off relationship.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] On the other hand, even if both color development and adhesion can be achieved, if the polyurethane dispersion 2 remaining on the surface 3 of the fabric 1 becomes too hard, the ability to follow deformation of the fabric decreases, and as a result, the polyurethane dispersion 2 may peel off due to deformation of the fabric.

[0192] In contrast, in this polyurethane dispersion, by adjusting the acid value of the polyurethane resin, the sum of the urethane group concentration and urea group concentration of the polyurethane resin, and the aromatic ring concentration of the polyurethane resin to predetermined values, it is possible to achieve both color development and adhesion, and to improve the ability to follow deformations of the fabric.

[0193] 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.

[0194] 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 formate 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.

[0195] 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.

[0196] Furthermore, when the total concentration of urethane groups and urea groups in the polyurethane resin increases, the polyurethane dispersion (specifically, the ink composition containing the polyurethane dispersion) tends to aggregate. As a result, the polyurethane dispersion (specifically, the ink composition containing the polyurethane dispersion) tends to remain on the surface of the fabric, which tends to harden the polyurethane dispersion. This tends to reduce the ability to follow deformations of the fabric.

[0197] In this polyurethane dispersion, the total concentration of urethane groups and urea groups in the polyurethane resin is adjusted to a predetermined value or less, thereby improving the ability to follow deformation of the fabric.

[0198] Furthermore, as the aromatic ring concentration of the polyurethane resin increases, the cohesive force of the polyurethane dispersion (specifically, the ink composition containing the polyurethane dispersion) tends to increase, resulting in a tendency for the polyurethane dispersion to become hard, which in turn tends to reduce its ability to conform to deformation of the fabric.

[0199] On the other hand, when the aromatic ring concentration of the polyurethane resin is reduced, the cohesive force of the polyurethane dispersion is weakened, and the ink composition containing the polyurethane dispersion is less likely to remain on the surface of the fabric, which tends to result in reduced color development and adhesion.

[0200] In this polyurethane dispersion, the concentration of aromatic rings in the polyurethane resin is adjusted to a predetermined range, which improves color development and adhesion, and also improves conformability to deformation of the fabric.

[0201] In this polyurethane dispersion, the acid value of the polyurethane resin, the sum of the urethane group concentration and urea group concentration of the polyurethane resin, and the aromatic ring concentration in the polyurethane resin have been described independently for ease of understanding, but in reality, they do not exert their effects independently, but rather depend on each other and exert a synergistic effect.

[0202] Furthermore, when droplets of an ink composition containing the polyurethane dispersion are ejected from a nozzle using an inkjet method to print onto fabric, the ink composition is required to be easily ejected from the nozzle.

[0203] In this polyurethane dispersion, the acid value of the polyurethane resin, the sum of the urethane group concentration and urea group concentration of the polyurethane resin, and the aromatic ring concentration in the polyurethane resin are the above-mentioned values, so that the viscosity can be adjusted and clogging can be suppressed, thereby improving the ejection properties from the nozzle.

[0204] The ink composition contains the polyurethane dispersion, and therefore exhibits excellent adhesion and followability when used to print fabrics. [Example]

[0205] 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 "Modes for Carrying Out the Invention." Furthermore, unless otherwise specified in the following description, "parts" and "%" are based on mass.

[0206] <Ingredient details> 1,3-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 HDI: Hexamethylene diisocyanate, manufactured by Tosoh Corporation PDI: 1,5-pentamethylene diisocyanate, trade name "Stabio PDI", manufactured by Mitsui Chemicals XDI: 1,3-xylylene diisocyanate, product name "Takenate 500", Mitsui Chemicals TDI: Tolylene diisocyanate P-2030: Aromatic ring-containing polyester polyol, reaction product of isophthalic acid and 3-methyl-1,5-pentanediol, manufactured by Kuraray Co., Ltd. P-2020: Aromatic ring-containing polyester polyol, reaction product of terephthalic acid and 3-methyl-1,5-pentanediol, manufactured by Kuraray Co., Ltd. UH-200: Polycarbonate diol, number average molecular weight 2000, manufactured by Ube Industries, Ltd. PTMG-2000: Polytetramethylene ether glycol, number average molecular weight 2000, manufactured by Mitsubishi Chemical Corporation 1,4-BG: 1,4-butanediol, Fujifilm Wako Pure Chemical Industries, Ltd. EG: Ethylene glycol, manufactured by Fujifilm Wako Pure Chemical Industries DMPA: 2,2-dimethylolpropionic acid, manufactured by Perstorp TEA: Triethylamine, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. HYD·H2O: Hydrazine monohydrate, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0207] <Preparation of aromatic ring-containing polyester polyol> Preparation Example 1 826.7 g of isophthalic acid (IPA) as a polybasic acid (aromatic ring-containing polybasic acid), 1006.4 g of sebacic acid (SbA) as a polybasic acid (non-aromatic ring-containing polybasic acid), and 180.2 g of ethylene glycol (EG) and 898.3 g of neopentyl glycol (NPG) as polyhydric alcohols (non-aromatic ring-containing polyhydric alcohols) were mixed.

[0208] Next, 0.1 g of tin octoate (esterification catalyst) was added to the mixture, and the reaction temperature was adjusted to 180-220°C under a nitrogen stream to cause an esterification reaction between the polybasic acid and the polyhydric alcohol. A predetermined amount of water and glycol were then distilled off to prepare an aromatic ring-containing polyester polyol. The hydroxyl value of the aromatic ring-containing polyester polyol was 44.9 mgKOH / g.

[0209] Preparation Example 2 1,342.1 g of isophthalic acid (IPA) as a polybasic acid (aromatic ring-containing polybasic acid), 1,633.8 g of sebacic acid (SbA) as a polybasic acid (non-aromatic ring-containing polybasic acid), and 282.2 g of ethylene glycol (EG) and 1,407.1 g of neopentyl glycol (NPG) as polyhydric alcohols (non-aromatic ring-containing polyhydric alcohols) were mixed.

[0210] Next, 0.1 g of tin octoate (esterification catalyst) was added to the mixture, and the reaction temperature was adjusted to 180-220°C under a nitrogen stream to cause an esterification reaction between the polybasic acid and the polyhydric alcohol. A predetermined amount of water and glycol were then distilled off to prepare an aromatic ring-containing polyester polyol. The hydroxyl value of the aromatic ring-containing polyester polyol was 14.0 mgKOH / g.

[0211] Preparation Example 3 In a reactor equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 42.1 parts by weight of isophthalic acid (aromatic ring-containing polybasic acid), 21.4 parts by weight of sebacic acid and 9.3 parts by weight of adipic acid (non-aromatic ring-containing polybasic acid), 7.7 parts by weight of ethylene glycol, 25.8 parts by weight of neopentyl glycol, and 11.2 parts by weight of butanediol, and 0.05 parts by weight of dibutyltin oxide were charged and esterified at 180 to 230 °C for 24 hours. Subsequently, a polycondensation reaction was carried out at 230 °C for 24 hours until the acid value reached 1 or less, and an aromatic ring-containing polyester polyol (acid value 0.3 mg KOH / g, aromatic ring concentration 2.53 mol / kg) was prepared. The hydroxyl value of the aromatic ring-containing polyester polyol was 56.1 mg KOH / g.

[0212] <Preparation of polyurethane dispersion> Example 1 A four-neck flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube was 286.5 parts by mass of the aromatic ring-containing polyester polyol of Preparation Example 1, 7.7 parts by mass of DMPA (a hydrophilic group-containing active hydrogen compound), and 84.7 parts by mass of acetonitrile were charged. Next, 46.7 parts by mass of 1.3-H6XDI (a polyisocyanate component) was added, and a urethane reaction was carried out at 80°C until the NCO concentration reached 1.4% by mass, yielding an isocyanate-terminated prepolymer (a reaction solution containing an isocyanate-terminated prepolymer).

[0213] Next, 338.9 parts by mass of acetonitrile was added to this reaction liquid, and after cooling to 30° C., 5.7 parts by mass of TEA (neutralizing agent) was added.

[0214] Next, 646.7 parts by mass of ion-exchanged water (aqueous dispersion) was gradually added while continuing stirring to disperse the isocyanate-terminated prepolymer in water, thereby preparing an aqueous dispersion of the isocyanate-terminated prepolymer.

[0215] Next, 3.3 parts by mass of HYD·H 2 O was added to the aqueous dispersion of the isocyanate group-terminated prepolymer, and then the mixture was allowed to react for 1 hour.

[0216] 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).

[0217] Example 2 ~ Example 5 , Example 7 Example 15 and Comparative Examples 1 to 7 A polyurethane dispersion (solid content 30% by mass) was prepared according to the same procedure as in Example 1. However, the compounding recipe was changed according to Tables 1 to 3.

[0218] <Evaluation> [Acid value] The acid value of the polyurethane resin of each example and comparative example was calculated from the ratio of the raw material components used, and the results are shown in Tables 1 to 3.

[0219] [Urethane group and urea group concentration] The concentrations of urethane groups and urea groups in the polyurethane resins of each example and each comparative example were calculated from the ratio of the raw material components used. The results are shown in Tables 1 to 3.

[0220] [Aromatic ring concentration] The aromatic ring concentration of the polyurethane resin of each example and each comparative example was calculated from the charging ratio of the raw material components. The results are shown in Tables 1 to 3.

[0221] [Color development] Kanakin No. 3 (100% cotton) fabric was cut into a length of 210 mm and a width of 30 mm to prepare the fabric.

[0222] Next, 4.5 g of acetic acid, 6.2 g of sodium acetate, and 89.3 g of water were mixed together to prepare a pretreatment agent.

[0223] Next, 40.0 g of the polyurethane dispersion (solid content concentration 30% by mass) of each Example and Comparative Example, 8.0 g of a colorant (Dystone X Color Blue MX, manufactured by Matsui Pigment Chemical Industry Co., Ltd., active ingredient 25% by mass), 20.0 g of ethylene glycol, and 32.0 g of water were mixed to prepare an ink composition.

[0224] Next, about 1.2 g of the pretreatment agent was applied to the fabric using a spray, and then about 2 g of the ink composition was applied to the fabric using a spray.

[0225] Thereafter, the fabric was heat treated at 110° C. for 10 minutes, thereby obtaining a printed item.

[0226] 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 to 3. {standard} 4: A film was formed on the fabric, and the color development was significantly high. 3: A film was formed on the fabric and the color development was somewhat high. 2: The ink composition penetrated into the fabric, and color development was somewhat poor. 1: The ink composition penetrated into the fabric, resulting in significantly reduced color development.

[0227] [Adhesion] Kanakin No. 3 was cut into a piece 50 mm long and 50 mm wide, moistened with distilled water, and used as a white friction cloth.

[0228] The printed fabric obtained in the color development test and the white cloth for rubbing were attached to a No. 428 Gakushin type abrasion tester (Yasuda Seiki Seisakusho Co., Ltd., Friction Tester Type II) and tested with a load of 200 g, an amplitude of 100 mm, and 100 reciprocating motions (30 times / min).

[0229] After the test, the printed fabric was visually observed for adhesion of the ink layer to Kanakin No. 3. The adhesion was evaluated according to the following criteria. The results are shown in Tables 1 to 3. Note that in Comparative Example 5, the ink composition soaked into the fabric too much that adhesion could not be observed. {standard} 4: The ink layer did not peel off and the entire ink film remained. 3: Part of the ink layer peeled off, but more than half of the ink film remained. 2: More than half of the ink layer has peeled off. 1: The entire ink layer has peeled off.

[0230] [Color transfer] The white friction cloth obtained in the adhesion test was measured for its L value (the higher the value, the whiter the cloth and the less staining) using a spectrocolorimeter (Spectro Color Meter 2000, Nippon Denshoku Industries Co., Ltd.). The L value of the white friction cloth before the test was 90 or higher. Color transfer was evaluated according to the following criteria. The results are shown in Tables 1 to 3. {standard} 4: The L value was 90 or more and no color transfer was observed. 3: Slight color transfer was observed when the L value was between 85 and 90. 2: Color transfer was confirmed when the L value was between 70 and 85. 1: Significant color transfer was observed when the L value was 70 or less.

[0231] [Texture] The printed textiles obtained in the color development test were observed with a touch. The texture was evaluated according to the following criteria. The results are shown in Tables 1 and 2. {standard} 4: It was flexible. 3: Some flexibility was felt. 2: It felt a little hard. 1: It was hard.

[0232] [Following ability] Printed textiles were prepared in accordance with the method for preparing printed textiles obtained in the color development test, except that polyester flat rubber was used instead of Kanakin No. 3. The resulting printed textile was stretched 1.5 times in the machine direction and then returned to its original shape 10 times, after which the state of the ink layer was visually observed. The tracking ability was evaluated according to the following criteria. The results are shown in Tables 1 and 2. {standard} 4: No particular changes were observed. 3: Some lifting was observed in the ink layer, but no cracking was observed. 2: Lifting and cracking were observed in part of the ink layer. 1: Cracks were observed in most of the ink layer.

[0233] [Solvent dilution viscosity] Distilled water was added to the polyurethane dispersion (solid content concentration 35% by mass) of each Example and Comparative Example to adjust the solid content concentration to 20% by mass, and the viscosity at 25°C was measured using a viscometer (model TVB-25L, manufactured by Toki Sangyo Co., Ltd.) Further, the viscosity at 25°C was measured in the same manner except that isopropanol was used instead of distilled water. The viscosity increase rate of the solution prepared with isopropanol relative to the viscosity of the solution prepared with distilled water was evaluated according to the following criteria. The results are shown in Tables 1 and 2. {standard} The ratio was less than 4:3.0. 3: 3.0 times or more and less than 5.0 times. 2: 5.0 times or more and less than 10.0 times. The ratio was more than 1:10.

[0234] [Filterability of Polyurethane Dispersions (PUD Filterability)] 20 g of the polyurethane dispersion (solid content concentration 35% by mass) of each Example and Comparative Example was sucked up into a syringe and extruded with syringe filters of different hole diameters attached, and the filterability was evaluated according to the following criteria. {standard} 4: All particles passed through 0.45 μm. 3: All particles passed through 3 μm. 2: All passed through 5 μm. 1: None of the particles passed through 5 μm.

[0235] [Table 1]

[0236] [Table 2]

[0237] [Table 3]

[0238] The above invention is provided as an exemplary embodiment of the present invention, but it is merely an example and should not be interpreted as being limiting. Modifications of the present invention that are obvious to those skilled in the art are intended to be included in the scope of the following claims. [Industrial Applicability]

[0239] The polyurethane dispersion and ink composition of the present invention can be suitably used, for example, in printing fabrics or leather.

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 is a reaction product of a polyisocyanate component with a polyol component containing a macropolyol and a hydrophilic group-containing active hydrogen compound, The macropolyol includes an aromatic ring-containing polyester polyol, The polyurethane resin has an acid value of 7.0 mgKOH / g or more and 10.0 mgKOH / g or less, the sum of the urethane group concentration and the urea group concentration of the polyurethane resin is 20.0 mass% or less; The polyurethane resin has an aromatic ring concentration of 5.0% by mass or more and 15.0% by mass or less.

2. 2. The polyurethane dispersion according to claim 1, wherein the polyurethane resin has a total urethane group concentration and urea group concentration of 10.0 mass% or less.

3. The polyurethane dispersion according to claim 1 , wherein the polyisocyanate component comprises an alicyclic polyisocyanate.

4. 2. The polyurethane dispersion according to claim 1, wherein the hydrophilic group-containing active hydrogen compound is an anionic group-containing active hydrogen compound.

5. The aromatic ring-containing polyester polyol is a reaction product of a polyhydric alcohol and a polybasic acid, The polyurethane dispersion according to claim 1 , wherein the polybasic acid includes an aromatic ring-containing polybasic acid and a non-aromatic ring-containing polybasic acid.

6. The polyurethane dispersion according to claim 5 , wherein the aromatic ring-containing polybasic acid is isophthalic acid.

7. An ink composition comprising the polyurethane dispersion of claim 1.

8. The ink composition according to claim 7, for printing fabrics or leather.

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