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 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 that includes a macropolyol and a hydrophilic group-containing active hydrogen compound. The weight-average molecular weight of the polyurethane resin is 50,000 or more. The polyisocyanate component and the chain extender are a prescribed combination.

Description

Polyurethane dispersion and ink composition

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

[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 an ink composition, a water-based inkjet ink containing a pigment (coloring material) and a water-soluble urethane resin (resin) having a weight-average molecular weight of 12,000 or more and 40,000 or less has been proposed (see, for example, Patent Document 1 below).

[0004] Japanese Patent Application Laid-Open No. 2022-093959

[0005] On the other hand, the water-soluble urethane resin of Patent Document 1 has a small weight-average molecular weight, which causes problems such as reduced fastness to friction and washing (hereinafter referred to as fastness) when used to print fabrics. This reduced fastness can lead to discoloration of the printed area or color transfer to white fabrics. Furthermore, the resulting product can feel sticky and have a strong tacky feel.

[0006] In order to improve fastness and reduce tackiness, it has been considered to increase the weight-average molecular weight of the water-soluble urethane resin, but increasing the weight-average molecular weight of the water-soluble urethane resin tends to decrease filterability. In other words, there is a trade-off between fastness and tackiness on the one hand and filterability on the other.

[0007] The present invention aims to provide a polyurethane dispersion that has excellent filterability, and when used to print fabrics, has excellent fastness and can reduce tackiness, and an ink composition containing the polyurethane dispersion.

[0008] 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 and a hydrophilic group-containing active hydrogen compound, the weight average molecular weight of the polyurethane resin being 50,000 or more, the polyisocyanate component being the following (A) and the chain extender being the following (F), or the polyisocyanate component being the following (A) and the chain extender being the following (F): The polyurethane dispersion is one in which the chain extender is (G) below, or the polyisocyanate component is (A) below and the chain extender is (H) below, or the polyisocyanate component is (B) below and the chain extender is (G) below, or the polyisocyanate component is (C) below and the chain extender is (G) below, or the polyisocyanate component is (D) below and the chain extender is (G) below, or the polyisocyanate component is (E) below and the chain extender is (H) below.(A) Polyisocyanate component A containing at least one selected from the group consisting of an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, and an araliphatic polyisocyanate having a tertiary isocyanate group; (B) Polyisocyanate component B containing an alicyclic polyisocyanate having only primary isocyanate groups; (C) Polyisocyanate component C containing an aliphatic polyisocyanate having only primary isocyanate groups; (D) Polyisocyanate component D containing an araliphatic polyisocyanate having only primary isocyanate groups; (E) Polyisocyanate component E containing an aromatic polyisocyanate; and (F) Chain extender F containing a polyamine having only primary amino groups, with one carbon atom bonded to the carbon at the α-position of the primary amino group. (G) Chain extender G containing hydrazine and at least one selected from the group consisting of a polyamine having only a primary amino group and having two or more carbon atoms bonded to the carbon at the α-position of the primary amino group, a polyamine having a secondary amino group, and a polyamine having a tertiary amino group. (H) Chain extender H consisting of water.

[0009] The present invention [2] includes the polyurethane dispersion according to the above [1], in which the polyisocyanate component is (A) below and the chain extender is (F) below, or the polyisocyanate component is (A) above and the chain extender is (G) above, or the polyisocyanate component is (A) above and the chain extender is (H) above, or the polyisocyanate component is (B) below and the chain extender is (F) below, or the polyisocyanate component is (B) above and the chain extender is (G) above.

[0010] The present invention [3] includes the polyurethane dispersion according to the above [1] or [2], wherein the acid value of the polyurethane resin is 6.5 mgKOH / g to 15.0 mgKOH / g.

[0011] The present invention [4] includes the polyurethane dispersion according to any one of the above [1] to [3], wherein the weight-average molecular weight of the polyurethane resin is 200,000 or more.

[0012] The present invention [5] includes an ink composition containing the polyurethane dispersion according to any one of the above [1] to [4].

[0013] In the polyurethane dispersion of the present invention, the weight average molecular weight of the polyurethane resin is at least 50000. Therefore, when printing fabrics, fastness can be improved and tackiness can be reduced.

[0014] Furthermore, in this polyurethane dispersion, the polyisocyanate component and the chain extender are in a predetermined combination, which results in excellent filterability.

[0015] The polyurethane dispersion is prepared by dispersing a polyurethane resin in water.

[0016] The polyurethane resin is a reaction product of an isocyanate-terminated prepolymer and a chain extender.

[0017] <Isocyanate Group-Terminated Prepolymer> The isocyanate group-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.

[0018] [Polyisocyanate Component] The polyisocyanate component will be described in detail later, but is selected from the following polyisocyanate components A to E depending on the type of chain extender.

[0019] (Polyisocyanate Component A) The polyisocyanate component A includes at least one selected from the group consisting of an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, and an araliphatic polyisocyanate having a tertiary isocyanate group.

[0020] The secondary isocyanate group is defined as a divalent functional group (-CHR-NCO (R represents an organic group)) in which one hydrogen atom (H) is bonded to a carbon atom (C) to which an isocyanate group (-NCO) is bonded.

[0021] The tertiary isocyanate group is a trivalent functional group (-CR) in which no hydrogen atom (H) is bonded to the carbon atom (C) to which the isocyanate group (-NCO) is bonded. １ R ２ -NCO(R １ and R ２ represents the same or different organic groups.

[0022] The alicyclic polyisocyanate having a secondary isocyanate group has a secondary isocyanate group and may have a primary isocyanate group, but does not have a tertiary isocyanate group.

[0023] Examples of alicyclic polyisocyanates having a secondary isocyanate group include alicyclic diisocyanates having both one secondary isocyanate group and one primary isocyanate group, and alicyclic diisocyanates having two secondary isocyanate groups.

[0024] An example of an alicyclic diisocyanate having one secondary isocyanate group and one primary isocyanate group is 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI).

[0025] Examples of alicyclic diisocyanates having two secondary isocyanate groups include cyclopentane diisocyanate (1,3- or 1,4-cyclopentane diisocyanate or a mixture thereof), cyclohexane diisocyanate (1,3- or 1,4-cyclohexane diisocyanate or a mixture thereof), methylcyclohexane diisocyanate (methyl-2,4- or methyl-2,6-cyclohexane diisocyanate or a mixture thereof), methylenebis(cyclohexyl isocyanate) (4,4'- or 2,4'-methylenebis(cyclohexyl isocyanate) or a mixture thereof) (H １２As the alicyclic diisocyanate having two secondary isocyanate groups, H １２ An example is MDI.

[0026] The alicyclic polyisocyanate having a secondary isocyanate group is preferably an alicyclic diisocyanate having one secondary isocyanate group and one primary isocyanate group.

[0027] The alicyclic polyisocyanate having a secondary isocyanate group can be used alone or in combination of two or more kinds.

[0028] The alicyclic polyisocyanate having a tertiary isocyanate group has a tertiary isocyanate group, and may also have a primary isocyanate group and a secondary isocyanate group.

[0029] Examples of alicyclic polyisocyanates having a tertiary isocyanate group include alicyclic diisocyanates having two tertiary isocyanate groups.

[0030] An example of an alicyclic diisocyanate having two tertiary isocyanate groups is bis(α,α-dimethylisocyanatomethyl)cyclohexane.

[0031] Alicyclic polyisocyanates having a tertiary isocyanate group can be used alone or in combination of two or more kinds.

[0032] The araliphatic polyisocyanate having a secondary isocyanate group has a secondary isocyanate group and may have a primary isocyanate group, but does not have a tertiary isocyanate group.

[0033] An example of an aralkyl polyisocyanate having a secondary isocyanate group is 1,3-bis(1-isocyanatoethyl)benzene.

[0034] The aralkyl polyisocyanates having a secondary isocyanate group may be used alone or in combination of two or more kinds.

[0035] The aralkyl polyisocyanate having a tertiary isocyanate group has a tertiary isocyanate group, and may also have a primary isocyanate group and a secondary isocyanate group.

[0036] Examples of aralkyl polyisocyanates having a tertiary isocyanate group include aralkyl diisocyanates having two tertiary isocyanate groups.

[0037] Examples of araliphatic diisocyanates having two tertiary isocyanate groups include 1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (TMXDI).

[0038] The aralkyl polyisocyanates having a tertiary isocyanate group may be used alone or in combination of two or more kinds.

[0039] The polyisocyanate component A contains, as a main component, at least one selected from the group consisting of an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, and an araliphatic polyisocyanate having a tertiary isocyanate group. Specifically, the content of the at least one selected from the group consisting of an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, and an araliphatic polyisocyanate having a tertiary isocyanate group, relative to the polyisocyanate component A, is, for example, more than 50% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0040] Furthermore, the polyisocyanate component A can contain, as optional components, derivatives of the above-mentioned alicyclic polyisocyanates (alicyclic polyisocyanates having a secondary isocyanate group, alicyclic polyisocyanates having a tertiary isocyanate group) and the above-mentioned araliphatic polyisocyanates (araliphatic polyisocyanates having a secondary isocyanate group, araliphatic polyisocyanates having a tertiary isocyanate group).

[0041] Examples of the derivatives include polymers of the above-mentioned alicyclic polyisocyanates and araliphatic polyisocyanates, allophanate derivatives, polyol derivatives, biuret derivatives, urea derivatives, oxadiazinetrione derivatives, carbodiimide derivatives, uretdione derivatives, and uretonimine derivatives.

[0042] Furthermore, polyisocyanate component A may also contain, as an optional component, a polyisocyanate other than the above-mentioned alicyclic polyisocyanates and araliphatic polyisocyanates (for example, an alicyclic polyisocyanate having only primary isocyanate groups (described below), an aliphatic polyisocyanate having only primary isocyanate groups (described below), an araliphatic polyisocyanate having only primary isocyanate groups (described below), and an aromatic polyisocyanate (described below)) and a derivative thereof (the derivative listed above for polyisocyanate component A).

[0043] The polyisocyanate component A preferably does not contain the above-mentioned optional components and comprises at least one selected from the group consisting of an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, and an araliphatic polyisocyanate having a tertiary isocyanate group. That is, the content of at least one selected from the group consisting of an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, and an araliphatic polyisocyanate having a tertiary isocyanate group is preferably 100% by mass based on the polyisocyanate component A.

[0044] (Polyisocyanate Component B) The polyisocyanate component B contains an alicyclic polyisocyanate having only primary isocyanate groups.

[0045] The primary isocyanate group is a monovalent functional group (-CH) in which two hydrogen atoms (H) are bonded to a carbon atom (C) to which an isocyanate group (-NCO) is bonded. ２ NCO).

[0046] Examples of alicyclic polyisocyanates having only primary isocyanate groups include alicyclic polyisocyanates having only two primary isocyanate groups.

[0047] Examples of alicyclic polyisocyanates having only two primary isocyanate groups include bis(isocyanatomethyl)cyclohexane (1,3- or 1,4-bis(isocyanatomethyl)cyclohexane or a mixture thereof) (H ６ XDI), for example, bis(isocyanatoethyl)cyclohexane (1,3- or 1,4-bis(isocyanatoethyl)cyclohexane or a mixture thereof), and bis(isocyanatomethyl)norbornane (2,5- or 2,6-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane or a mixture thereof) (NBDI).

[0048] As the alicyclic polyisocyanate having only two primary isocyanate groups, preferably ６ As the alicyclic polyisocyanate having only two primary isocyanate groups, 1,3-H ６ XDI is an example.

[0049] Alicyclic polyisocyanates having only primary isocyanate groups can be used alone or in combination of two or more kinds.

[0050] The polyisocyanate component B contains, as a main component, an alicyclic polyisocyanate having only primary isocyanate groups. Specifically, the content of the alicyclic polyisocyanate having only primary isocyanate groups relative to the polyisocyanate component B is, for example, more than 50% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0051] Furthermore, polyisocyanate component B may contain, as an optional component, a derivative of an alicyclic polyisocyanate having only a primary isocyanate group (the derivatives listed above for polyisocyanate component A).

[0052] Furthermore, polyisocyanate component B may also contain, as an optional component, a polyisocyanate other than an alicyclic polyisocyanate having only a primary isocyanate group (for example, an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, an araliphatic polyisocyanate having a tertiary isocyanate group, an aliphatic polyisocyanate having only a primary isocyanate group (described below), an araliphatic polyisocyanate having only a primary isocyanate group (described below), and an aromatic polyisocyanate (described below)) and a derivative thereof (the derivatives listed above for polyisocyanate component A).

[0053] The polyisocyanate component B preferably does not contain the above-mentioned optional components and is composed of an alicyclic polyisocyanate having only primary isocyanate groups. That is, the content of the alicyclic polyisocyanate having only primary isocyanate groups is preferably 100 mass% relative to the polyisocyanate component B.

[0054] (Polyisocyanate Component C) Polyisocyanate component C includes an aliphatic polyisocyanate having only primary isocyanate groups.

[0055] Examples of aliphatic polyisocyanates having only primary isocyanate groups include aliphatic polyisocyanates having only two primary isocyanate groups.

[0056] Examples of aliphatic polyisocyanates having only two primary isocyanate groups include 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.

[0057] The aliphatic polyisocyanate having only two primary isocyanate groups preferably includes 1,6-HDI and 1,5-PDI.

[0058] Aliphatic polyisocyanates having only primary isocyanate groups can be used alone or in combination of two or more kinds.

[0059] The polyisocyanate component C contains, as a main component, an aliphatic polyisocyanate having only primary isocyanate groups. Specifically, the content of the aliphatic polyisocyanate having only primary isocyanate groups relative to the polyisocyanate component C is, for example, more than 50 mass%, preferably 60 mass% or more, more preferably 70 mass% or more, and even more preferably 90 mass% or more.

[0060] Furthermore, polyisocyanate component C may contain, as an optional component, a derivative of an aliphatic polyisocyanate having only primary isocyanate groups (the derivatives listed above for polyisocyanate component A).

[0061] Furthermore, polyisocyanate component C may also contain, as an optional component, a polyisocyanate other than an aliphatic polyisocyanate having only a primary isocyanate group (for example, an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, an araliphatic polyisocyanate having a tertiary isocyanate group, an alicyclic polyisocyanate having only a primary isocyanate group, an araliphatic polyisocyanate having only a primary isocyanate group (described later), and an aromatic polyisocyanate (described later)), and a derivative thereof (the derivatives listed above for polyisocyanate component A).

[0062] The polyisocyanate component C preferably does not contain the above-mentioned optional components and is composed of an aliphatic polyisocyanate having only primary isocyanate groups. That is, the content of the aliphatic polyisocyanate having only primary isocyanate groups is preferably 100 mass% relative to the polyisocyanate component C.

[0063] (Polyisocyanate Component D) Polyisocyanate Component D contains an araliphatic polyisocyanate having only primary isocyanate groups.

[0064] Examples of araliphatic polyisocyanates having only primary isocyanate groups include araliphatic diisocyanates having only two primary isocyanate groups.

[0065] An example of an araliphatic diisocyanate having only two primary isocyanate groups is xylylene diisocyanate (1,2-, 1,3-, or 1,4-xylylene diisocyanate or a mixture thereof) (XDI).

[0066] The araliphatic polyisocyanates having only primary isocyanate groups can be used alone or in combination of two or more kinds.

[0067] The polyisocyanate component D contains, as a main component, an araliphatic polyisocyanate having only primary isocyanate groups. Specifically, the content of the araliphatic polyisocyanate having only primary isocyanate groups relative to the polyisocyanate component D is, for example, more than 50 mass%, preferably 60 mass% or more, more preferably 70 mass% or more, and even more preferably 90 mass% or more.

[0068] Furthermore, polyisocyanate component D may contain, as an optional component, a derivative of an araliphatic polyisocyanate having only primary isocyanate groups (the derivatives listed above for polyisocyanate component A).

[0069] Furthermore, polyisocyanate component D may also contain, as an optional component, a polyisocyanate other than an araliphatic polyisocyanate having only a primary isocyanate group (for example, an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, an araliphatic polyisocyanate having a tertiary isocyanate group, an alicyclic polyisocyanate having only a primary isocyanate group, an aliphatic polyisocyanate having only a primary isocyanate group, and an aromatic polyisocyanate (described below)) and a derivative thereof (the derivatives listed above for polyisocyanate component A).

[0070] Polyisocyanate component D preferably does not contain the above-mentioned optional components and is composed of an araliphatic polyisocyanate having only primary isocyanate groups. That is, the content of the araliphatic polyisocyanate having only primary isocyanate groups is preferably 100 mass% relative to polyisocyanate component D.

[0071] (Polyisocyanate Component E) Polyisocyanate component E contains an aromatic polyisocyanate.

[0072] 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.

[0073] As the aromatic polyisocyanate, preferably, MDI and TDI are used.

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

[0075] The polyisocyanate component E contains an aromatic polyisocyanate as a main component. Specifically, the content of the aromatic polyisocyanate relative to the polyisocyanate component E is, for example, more than 50% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0076] Furthermore, the polyisocyanate component E may contain, as an optional component, a derivative of an aromatic polyisocyanate (the derivatives listed above for the polyisocyanate component A).

[0077] Furthermore, polyisocyanate component E can also contain, as an optional component, a polyisocyanate other than an aromatic polyisocyanate (for example, an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, an araliphatic polyisocyanate having a tertiary isocyanate group, an alicyclic polyisocyanate having only primary isocyanate groups, an aliphatic polyisocyanate having only primary isocyanate groups, and an araliphatic polyisocyanate having only primary isocyanate groups) and a derivative thereof (the derivatives listed above for polyisocyanate component A).

[0078] The polyisocyanate component E preferably does not contain the above-mentioned optional components and is composed of an aromatic polyisocyanate. That is, the content of the aromatic polyisocyanate relative to the polyisocyanate component E is preferably 100 mass %.

[0079] [Polyol Component] The polyol component contains, as essential components, a macropolyol and a hydrophilic group-containing active hydrogen compound.

[0080] (Macropolyol) The macropolyol is a compound having two or more hydroxyl groups at the molecular terminals and having a number average molecular weight of 400 or more and 10,000 or less, preferably 500 or more and 5,000 or less.

[0081] The average functionality of the macropolyol is, for example, 2 or more, and for example, 3 or less, and preferably 2.

[0082] Examples of the macropolyol include polycarbonate polyol, polyether polyol, polyester 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, polyether polyol, and polyester polyol.

[0083] 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).

[0084] Examples of polyether polyols include polyoxyalkylene (having 2 to 3 carbon atoms) polyols and polytetramethylene ether polyols.

[0085] Examples of polyoxyalkylene (carbon number: 2 to 3) polyols include addition polymers of alkylene oxides having 2 to 3 carbon atoms using, as an initiator, low-molecular-weight polyols described below and known low-molecular-weight polyamines.

[0086] 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.

[0087] 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.

[0088] Furthermore, the polyoxyalkylene (carbon number 2 to 3) polyol also includes polytrimethylene ether glycol.

[0089] An example of polytrimethylene ether glycol is a glycol obtained by polycondensation reaction of 1,3-propanediol derived from plant components.

[0090] Examples of polytetramethylene ether polyols include ring-opening polymers (polytetramethylene ether glycol (crystalline (25°C))) obtained by cationic polymerization of tetrahydrofuran, and amorphous (non-crystalline (25°C)) polytetramethylene ether glycols obtained by copolymerizing polymerization units of tetrahydrofuran or the like with alkyl-substituted tetrahydrofuran or the above-mentioned dihydric alcohols.

[0091] As the polyether polyol, preferably, polytetramethylene ether polyol is used, and more preferably, polytetramethylene ether glycol is used.

[0092] Examples of polyester polyols include polycondensates obtained by reacting a low-molecular-weight polyol (described below) with a polybasic acid under known conditions.

[0093] The low molecular weight polyol is preferably an alkanediol having 2 to 6 carbon atoms, and more preferably 3-methyl-1,5-pentanediol.

[0094] Examples of polybasic acids include aromatic dibasic acids, alicyclic dibasic acids, and aliphatic dibasic acids.

[0095] Examples of aromatic dibasic acids include aromatic carboxylic acids. Examples of aromatic carboxylic acids include phthalic acid (orthophthalic acid, isophthalic acid, terephthalic acid) and trimellitic acid. Examples of aromatic dibasic acids include phthalic acid, preferably phthalic acid. Examples of aromatic dibasic acids include terephthalic acid, more preferably terephthalic acid.

[0096] Examples of alicyclic dibasic acids include alicyclic carboxylic acids, such as hexahydroxybenzoic acid and 1,2-hexahydrophthalic acid.

[0097] Examples of the aliphatic dibasic acid include aliphatic carboxylic acids, such as oxalic acid, malonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, hexylsuccinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylsuccinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid, and preferably adipic acid and sebacic acid.

[0098] The polybasic acid is preferably an aromatic dibasic acid.

[0099] A preferred example of such a polyester polyol is a polycondensation product of 3-methyl-1,5-pentanediol and terephthalic acid.

[0100] As the macropolyol, preferably, polycarbonate polyol is used.

[0101] The macropolyols can be used alone or in combination of two or more kinds.

[0102] The blending ratio of the macropolyol relative to 100 parts by mass of the total amount of the polyol components is, for example, 90 parts by mass to 99 parts by mass, or preferably 95 parts by mass to 98 parts by mass.

[0103] (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. Examples of the active hydrogen groups include a hydroxyl group and an amino group.

[0104] 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.

[0105] 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. Examples of the nonionic group include a polyoxyethylene group. Examples of the active hydrogen group-containing compound containing a nonionic group include polyoxyethylene glycol, one-end-blocked polyoxyethylene glycol, and polyols containing polyoxyethylene side chains.

[0106] 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.

[0107] The active hydrogen group-containing compound containing anionic group is a compound that has one or more anionic groups and two or more active hydrogen groups.The anionic group can be exemplified by a carboxy group (carboxylic acid group) and a sulfo group (sulfonic acid group), and preferably by a carboxy group.In addition, in the active hydrogen group-containing compound containing anionic group, the active hydrogen group can be exemplified by a hydroxyl group and an amino group, and preferably by a hydroxyl group.That is, the active hydrogen group-containing compound containing anionic group can be preferably an organic compound that has one carboxyl group and two hydroxyl groups.

[0108] An example of an organic compound having one carboxy group and two hydroxyl groups is a carboxy group-containing polyol. An example of a carboxy group-containing polyol is a polyhydroxyalkanoic acid. 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 one carboxy group and two hydroxyl groups is 2,2-dimethylolpropionic acid.

[0109] The active hydrogen group-containing compound containing cationic group is a compound that has one or more cationic groups and two or more active hydrogen groups.The cationic group can be, for example, a tertiary amino group (a tertiary amine that can form a tertiary ammonium salt).In addition, in the active hydrogen group-containing compound containing cationic group, the active hydrogen group can be, for example, a hydroxyl group and an amino group, and preferably a hydroxyl group.That is, the active hydrogen group-containing compound containing cationic group can be, preferably, an organic compound that has one tertiary amino group and two hydroxyl groups.

[0110] Examples of organic compounds having one tertiary amino group and two hydroxyl groups include N-alkyldialkanolamines, such as N-methyldiethanolamine, N-propyldiethanolamine, N-butyldiethanolamine, and N-methyldipropanolamine.

[0111] 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.

[0112] The hydrophilic group-containing active hydrogen compounds can be used alone or in combination of two or more kinds.

[0113] The blending ratio of the hydrophilic group-containing active hydrogen compound is, for example, 1 to 10 parts by mass, or preferably 2 to 5 parts by mass, per 100 parts by mass of the total amount of the polyol components.

[0114] 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.

[0115] (Low Molecular Weight Polyol) The polyol component may also contain a low molecular weight polyol (a low molecular weight polyol excluding hydrophilic group-containing active hydrogen compounds) as an optional component.

[0116] The low-molecular-weight polyol is a compound having a number-average molecular weight of 40 or more but less than 400, preferably 40 or more but less than 300.

[0117] The number of functional groups of the low molecular weight polyol is not particularly limited, but is preferably 2.

[0118] 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).

[0119] The diol having 2 to 6 carbon atoms has a number average molecular weight of 40 or more but less than 400, preferably 40 or more but less than 300, 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.

[0120] 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.

[0121] 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 diethylene glycol, triethylene glycol, and dipropylene glycol, and preferably triethylene glycol.

[0122] An example of the alkenediol having 2 to 6 carbon atoms is 1,4-dihydroxy-2-butene.

[0123] The other low-molecular-weight polyols are compounds having a number-average molecular weight of 40 or more but less than 400, preferably 40 or more but less than 300, and having two or more hydroxyl groups in one molecule, and examples thereof include diols (dihydric alcohols) having 7 or more carbon atoms and low-molecular-weight polyols having 3 or more hydric atoms.

[0124] 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 40 or more but less than 300, and having 7 or more carbon atoms and two hydroxyl groups per molecule. Examples of such compounds 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.

[0125] 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.

[0126] The trihydric or higher low-molecular-weight polyol has a number-average molecular weight of 40 or more but less than 400, preferably 40 or more but less than 300, 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.

[0127] Examples of the trivalent or higher low-molecular-weight polyol also include trivalent or higher polyalkylene oxides having a number average molecular weight of 40 or more but less than 400, preferably 40 or more and 300 or less. Such polyalkylene oxides can be obtained as polyethylene polyols, polypropylene polyols, and polyethylene-polypropylene 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.

[0128] The low molecular weight polyols can be used alone or in combination of two or more kinds.

[0129] The blending ratio of the low-molecular-weight polyol is, for example, 1 to 15 parts by mass with respect to 100 parts by mass of the total amount of the polyol components.

[0130] 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.

[0131] [Preparation of Isocyanate-Terminated Prepolymer] The isocyanate-terminated prepolymer is obtained by reacting a polyisocyanate component with a polyol component.

[0132] 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.

[0133] In solution polymerization, for example, the above components are mixed in an organic solvent (solvent) under a nitrogen atmosphere and reacted.

[0134] In this reaction, the equivalent ratio of isocyanate groups in the polyisocyanate component to active hydrogen groups (hydroxyl groups and / or amino groups) in the polyol component (isocyanate groups / active hydrogen groups) exceeds 1, for example, 1.2 or more, preferably 1.3 or more, and 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.

[0135] As for reaction conditions, the reaction temperature is, for example, 20° C. to 90° C., preferably 40° C. to 80° C. The reaction time is 1 hour to 20 hours.

[0136] 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.

[0137] In the polymerization, a reaction catalyst (for example, an amine-based, tin-based, or lead-based catalyst) may be added as needed.

[0138] In the above reaction, unreacted polyisocyanate components and / or unreacted polyol components can be removed by known methods such as distillation or extraction.

[0139] This produces an isocyanate-terminated prepolymer, which is a reaction product of the polyisocyanate component and the polyol component.

[0140] 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.

[0141] The isocyanate-terminated prepolymer is a polyurethane prepolymer having at least one (preferably multiple, more preferably two) free isocyanate group at its molecular end, and the isocyanate group content (isocyanate group content calculated as solid content excluding solvent, i.e., isocyanate group concentration) is, for example, 1.2 to 5.0 mass%, preferably 1.3 to 3.0 mass%, more preferably 1.5 to 2.0 mass%.

[0142] 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.

[0143] As the neutralizing agent, a conventional base (e.g., triethylamine) is used when the ionic group is an anionic group, and a conventional acid (e.g., acetic acid) is used when the ionic group is a cationic group.

[0144] In particular, when the ionic group is an anionic group (preferably a carboxy group), the neutralizing agent is added in an amount of 0.6 to 1.2 equivalents, preferably 0.8 to 1.1 equivalents, per equivalent of the anionic group.

[0145] <Chain Extender> The chain extender will be described in detail later, but is selected from the following chain extenders F to H depending on the type of polyisocyanate component.

[0146] [Chain Extender F] Chain extender F contains a polyamine having only primary amino groups, with one carbon atom bonded to the carbon at the α-position of the primary amino group.

[0147] Examples of polyamines having only primary amino groups with one carbon atom bonded to the α-position carbon of the primary amino group include methanediamine, 1,2-ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, and 2-methyl-1,5-pentanediamine. Preferred examples of polyamines having only primary amino groups with one carbon atom bonded to the α-position carbon of the primary amino group include 1,2-ethylenediamine, 1,4-butanediamine, and 1,6-hexanediamine.

[0148] Polyamines having only primary amino groups with one carbon atom bonded to the carbon at the α-position of the primary amino group can be used alone or in combination of two or more kinds.

[0149] Chain extender F contains, as a main component, a polyamine having only primary amino groups and having one carbon atom bonded to the carbon at the α-position of the primary amino group. Specifically, the content of the polyamine having only primary amino groups and having one carbon atom bonded to the carbon at the α-position of the primary amino group is, for example, more than 50% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, relative to chain extender F.

[0150] Furthermore, chain extender F may also contain, as an optional component, a chain extender other than a polyamine having only a primary amino group and having one carbon atom bonded to the carbon at the α-position of the primary amino group (for example, at least one selected from the group consisting of s-hydrazine, which will be described later, and a polyamine having only a primary amino group and having two or more carbon atoms bonded to the carbon at the α-position of the primary amino group, a polyamine having a secondary amino group, and a polyamine having a tertiary amino group).

[0151] Chain extender F preferably does not contain the above-mentioned optional components and is composed of a polyamine having only primary amino groups with one carbon atom bonded to the carbon at the α-position of the primary amino group. That is, the content of the polyamine having only primary amino groups with one carbon atom bonded to the carbon at the α-position of the primary amino group is preferably 100% by mass relative to chain extender F.

[0152] [Chain Extender G] Chain extender G contains at least one selected from the group consisting of hydrazine and a polyamine having only a primary amino group and having two or more carbon atoms bonded to the carbon at the α-position of the primary amino group, a polyamine having a secondary amino group, and a polyamine having a tertiary amino group.

[0153] Hydrazine includes hydrazine hydrates and derivatives of hydrazine, such as succinic acid dihydrazide and adipic acid dihydrazide.

[0154] The hydrazines can be used alone or in combination of two or more kinds.

[0155] Examples of polyamines having only primary amino groups and having two or more carbon atoms bonded to the carbon at the α-position of the primary amino group include isophoronediamine, 1,2-propanediamine, 1,2-diamino-2-methylpropane, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, and 4,4'-methylenebis(cyclohexylamine). A preferred example of a polyamine having only primary amino groups and having two or more carbon atoms bonded to the carbon at the α-position of the primary amino group is isophoronediamine.

[0156] Polyamines having only primary amino groups and having two or more carbon atoms bonded to the carbon at the α-position of the primary amino group can be used alone or in combination of two or more kinds.

[0157] The polyamine having a secondary amino group has a secondary amino group and may have a primary amino group, but does not have a tertiary amino group.

[0158] Examples of polyamines having a secondary amino group include aliphatic polyamines having a secondary amino group and amino alcohols having a secondary amino group.

[0159] Examples of aliphatic polyamines having a secondary amino group include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and N-ethylethylenediamine. Preferred examples of aliphatic polyamines having a secondary amino group include diethylenetriamine, triethylenetetramine, and N-ethylethylenediamine.

[0160] Examples of amino alcohols having a secondary amino group 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). Preferred examples of amino alcohols having a secondary amino group include N-(2-aminoethyl)ethanolamine.

[0161] The polyamines having a secondary amino group can be used alone or in combination of two or more kinds.

[0162] The polyamine having a tertiary amino group has a tertiary amino group, and may also have a primary amino group and a secondary amino group.

[0163] Examples of polyamines having a tertiary amino group include aliphatic polyamines having a tertiary amino group and alicyclic polyamines having a tertiary amino group.

[0164] Examples of aliphatic polyamines having a tertiary amino group include 2,2-diamino-N-methyldiethylamine and tris(2-aminoethyl)amine.

[0165] An example of the alicyclic polyamine having a tertiary amino group is N-(2-aminoethyl)piperazine.

[0166] The polyamines having a tertiary amino group can be used alone or in combination of two or more kinds.

[0167] Chain extender G contains, as a main component, at least one selected from the group consisting of hydrazine, a polyamine having only a primary amino group and having two or more carbon atoms bonded to the carbon at the α-position of the primary amino group, a polyamine having a secondary amino group, and a polyamine having a tertiary amino group. Specifically, the content of at least one selected from the group consisting of hydrazine, a polyamine having only a primary amino group and having two or more carbon atoms bonded to the carbon at the α-position of the primary amino group, a polyamine having a secondary amino group, and a polyamine having a tertiary amino group is, for example, more than 50% by mass, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, relative to chain extender G.

[0168] Furthermore, the chain extender G may also contain, as an optional component, a chain extender other than at least one selected from the group consisting of hydrazine and polyamines having only primary amino groups and having two or more carbon atoms bonded to the carbon at the α-position of the primary amino group, polyamines having secondary amino groups, and polyamines having tertiary amino groups (polyamines having only primary amino groups and having one carbon atom bonded to the carbon at the α-position of the primary amino group).

[0169] Chain extender G preferably does not contain the above optional components and comprises at least one selected from the group consisting of hydrazine, a polyamine having only a primary amino group and having two or more carbon atoms bonded to the α-carbon of the primary amino group, a polyamine having a secondary amino group, and a polyamine having a tertiary amino group. That is, the content of at least one selected from the group consisting of hydrazine, a polyamine having only a primary amino group and having two or more carbon atoms bonded to the α-carbon of the primary amino group, a polyamine having a secondary amino group, and a polyamine having a tertiary amino group is preferably 100% by mass relative to chain extender G.

[0170] [Chain Extender H] The chain extender H is composed of water. The water used to disperse the isocyanate group-terminated prepolymer described below can also be used as is.

[0171] <Combination of Polyisocyanate Component and Chain Extender> The polyisocyanate component and the chain extender are used in a predetermined combination.

[0172] Specifically, the predetermined combination is a combination of polyisocyanate component A and chain extender F, or a combination of polyisocyanate component A and chain extender G, or a combination of polyisocyanate component A and chain extender H, or a combination of polyisocyanate component B and chain extender G, or a combination of polyisocyanate component C and chain extender G, or a combination of polyisocyanate component D and chain extender G, or a combination of polyisocyanate component E and chain extender H.

[0173] A specific combination of a polyisocyanate component and a chain extender can improve filterability.

[0174] Furthermore, from the viewpoint of achieving a balanced improvement in the evaluations of filterability, texture, tackiness, and fastness (color transfer), the polyisocyanate component and the chain extender are preferably selected from a combination of polyisocyanate component A and chain extender F, a combination of polyisocyanate component A and chain extender G, a combination of polyisocyanate component B and chain extender F, or a combination of polyisocyanate component B and chain extender G.

[0175] <Preparation of Polyurethane Resin> The polyurethane resin is obtained by reacting an isocyanate group-terminated prepolymer with a chain extender.

[0176] Specifically, an isocyanate-terminated prepolymer and a chain extender are reacted in water, for example, to obtain a polyurethane resin (polyurethane dispersion).

[0177] 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.

[0178] To disperse the isocyanate-terminated prepolymer in water, 50 to 1,000 parts by mass of water (sometimes referred to as water dispersion water) is added to 100 parts by mass of the isocyanate-terminated prepolymer while stirring the water.

[0179] 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 of the active hydrogen groups (amino groups and hydroxyl groups) of the chain extender to the isocyanate groups of the isocyanate group-terminated prepolymer (active hydrogen groups / isocyanate groups) is, for example, 0.8 or more and 1.2 or less.

[0180] 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.

[0181] 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.

[0182] This allows the chains of the isocyanate-terminated prepolymer to be extended by the chain extender, thereby obtaining a polyurethane resin prepared as an aqueous dispersion (polyurethane dispersion).

[0183] Furthermore, when the chain extender is chain extender H (i.e., when water is used as the chain extender), the isocyanate group-terminated prepolymer is dispersed in water, and then the dispersion is stirred without blending any other chain extender than water, thereby extending the chain of the isocyanate group-terminated prepolymer with the chain extender (water).

[0184] The acid value of the polyurethane resin is, for example, 5.0 mgKOH / g to 16.0 mgKOH / g, preferably 6.5 mgKOH / g to 15.0 mgKOH / g, more preferably 7.0 mgKOH / g to 14.5 mgKOH / g, even more preferably 8.0 mgKOH / g to 12.0 mgKOH / g, and particularly preferably 9.0 mgKOH / g to 10.0 mgKOH / g.

[0185] Specifically, the acid value of the polyurethane resin is, for example, 5.0 mgKOH / g or more, preferably, from the viewpoint of further improving filterability, 6.5 mgKOH / g or more, more preferably 7.0 mgKOH / g or more, even more preferably 8.0 mgKOH / g or more, and particularly preferably 9.0 mgKOH / g or more.

[0186] When the acid value of the polyurethane resin is equal to or higher than the above lower limit, the filterability can be further improved.

[0187] The acid value of the polyurethane resin is, for example, 16.0 mgKOH / g or less, preferably, from the viewpoint of improving texture, 15.0 mgKOH / g or less, more preferably 14.5 mgKOH / g or less, even more preferably 12.0 mgKOH / g or less, and particularly preferably 10.0 mgKOH / g or less.

[0188] When the acid value of the polyurethane resin is equal to or less than the above upper limit, the texture can be improved when the fabric is printed.

[0189] 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).

[0190] The acid value can be calculated from the ratio of the components. The acid value can also be measured by a method according to JIS K 0070 (1992). The acid value can also be calculated by the acid value of the hydrolysis product of the polyurethane resin by alkaline hydrolysis. １ It can also be measured by H-NMR.

[0191] The total of the urethane group concentration and the urea group concentration of the polyurethane resin is, for example, 5.0% by mass to 20.0% by mass, preferably 7.0% by mass to 17.0% by mass, more preferably 8.0% by mass to 15.5% by mass, even more preferably 8.0% by mass to 15.0% by mass, particularly preferably 8.5% by mass to 12.0% by mass, most preferably 9.0% by mass to 11.0% by mass, or even 9.0% by mass to 10.0% by mass.

[0192] Specifically, the sum of the urethane group concentration and the urea group concentration of the polyurethane resin is, for example, 5.0 mass% or more, preferably 7.0 mass% or more, preferably 8.0 mass% or more, more preferably 8.5 mass% or more, and even more preferably 9.0 mass% or more.

[0193] When the total concentration of the urethane group and the urea group in the polyurethane resin is equal to or higher than the lower limit, the filterability can be improved.

[0194] The total concentration of urethane groups and urea groups in the polyurethane resin is, for example, 20.0 mass% or less, preferably 17.0 mass% or less, more preferably 15.5 mass% or less, even more preferably 15.0 mass% or less, particularly preferably 12.0 mass% or less, most preferably 11.0 mass% or less, or even 10.0 mass% or less.

[0195] If the total concentration of the urethane group and the urea group in the polyurethane resin is equal to or less than the upper limit, the texture can be improved when the fabric is printed.

[0196] The total of the urethane group concentration and the urea group concentration can be calculated from the charge ratio of the raw material components. １ It can also be measured by H-NMR.

[0197] The weight average molecular weight of the polyurethane resin is 50,000 or more, preferably 100,000 or more, more preferably 150,000 or more, even more preferably 180,000 or more, and particularly preferably 200,000 or more from the viewpoint of further improving fastness and further reducing tackiness.

[0198] If the weight average molecular weight of the polyurethane resin is at least the above lower limit, fastness can be improved and tackiness can be reduced when printing fabrics.

[0199] On the other hand, if the weight average molecular weight of the polyurethane resin is less than the above lower limit, fastness is reduced when printing fabrics, and tackiness cannot be reduced.

[0200] The weight average molecular weight of the polyurethane resin is, for example, 500,000 or less, or preferably 400,000 or less.

[0201] The weight-average molecular weight of the polyurethane resin is measured by gel permeation chromatography (GPC) and is calculated in terms of polystyrene. Specifically, it can be measured under the following conditions using dimethylacetamide dissolved in lithium bromide at a concentration of 0.86 g / L as the developing solvent. {Conditions} Apparatus: EcoSEC HLC-8320GPC (manufactured by Tosoh Corporation) Column: Two TSKgel α-M columns (manufactured by Tosoh Corporation) Flow rate: 0.6 ml / min Sample: Prepared by dissolving in the developing solvent at a concentration of 10 mg / mL Column temperature: 40°C Injection volume: 100 μl Detector: Differential refractometer Sampling time interval: 0.015 seconds

[0202] The solids concentration of the polyurethane dispersion is, for example, 10% by mass to 50% by mass, or preferably 20% by mass to 40% by mass.

[0203] <Use of Polyurethane Dispersion> The polyurethane dispersion is suitably used in the ink composition as a resin (dispersant) for dispersing the coloring material and as a resin (binder) for fixing the coloring material to the fabric.

[0204] The ink composition is a raw material for printing fabrics.

[0205] 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.

[0206] The ink composition contains a colorant and the polyurethane dispersion.

[0207] The coloring material is not particularly limited, and known coloring materials can be used.

[0208] The polyurethane dispersion is a component in the ink composition that disperses the coloring material or fixes the coloring material to the fabric.

[0209] When the polyurethane dispersion is used as a resin for dispersing a colorant, the blending ratio of the polyurethane dispersion is, for example, 500 parts by mass to 1000 parts by mass relative to 100 parts by mass of the colorant. When the polyurethane dispersion is used as a resin for fixing a colorant to a fabric, the blending ratio of the polyurethane dispersion is, for example, 3% by mass to 25% by mass relative to the ink composition.

[0210] The ink composition is prepared by mixing a colorant (including a colorant dispersed in a resin other than the polyurethane dispersion) and a polyurethane dispersion.

[0211] Furthermore, 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 if necessary. The humectants, penetrants, chelating agents, preservatives, and pH adjusters described in JP 2021-165353 A can be used.

[0212] The ink composition can also be diluted with water and / or an organic solvent (e.g., ethylene glycol).

[0213] Next, a method for printing fabric using this ink composition will be described in detail.

[0214] In order to print a fabric using the ink composition, the fabric is first pretreated as necessary.

[0215] To pretreat the fabric, the fabric is treated with a pretreatment agent (eg, an organic acid).

[0216] Next, the ink composition is applied to the fabric. A known method (e.g., a spray method or an inkjet method) is selected as the method for applying the ink composition to the fabric. In this manner, the ink composition is applied to the fabric.

[0217] Next, the fabric (the fabric to which the ink composition has been applied) is heated.

[0218] The heating temperature is, for example, 80° C. or more, preferably 100° C. or more, and for example, 120° C. or less. The heating time is, for example, 1 minute or more, preferably 5 minutes or more, and for example, 60 minutes or less, preferably 30 minutes or less, more preferably 15 minutes or less.

[0219] This results in printing of the fabric (i.e., obtaining a printed product).

[0220] Since the ink composition contains the polyurethane dispersion described above, it is possible to produce printed items that are excellent in color development and adhesion.

[0221] <Effects> In the polyurethane dispersion, the weight-average molecular weight of the polyurethane resin is at least 50,000. Therefore, when printing fabrics, fastness can be improved and tackiness can be reduced.

[0222] Furthermore, in this polyurethane dispersion, the polyisocyanate component and the chain extender are in a predetermined combination, which results in excellent filterability.

[0223] Specifically, when the weight-average molecular weight of a polyurethane resin is small, such as the water-soluble urethane resin of Patent Document 1, the fastness tends to decrease when printing fabrics, and the resulting product tends to feel sticky and have a strong tacky feel.

[0224] On the other hand, from the viewpoint of improving fastness and reducing tackiness, increasing the weight-average molecular weight of the water-soluble urethane resin has been considered, but increasing the weight-average molecular weight of the polyurethane resin tends to decrease filterability. In other words, there is a trade-off between fastness and tackiness and filterability.

[0225] In contrast, in the polyurethane dispersion, the weight-average molecular weight of the polyurethane resin is 50,000 or more, and the polyisocyanate component and the chain extender are in a predetermined combination. Because the weight-average molecular weight of the polyurethane resin is 50,000 or more, fastness can be improved and tackiness can be reduced when printing fabrics, and because the polyisocyanate component and the chain extender are in a predetermined combination, filterability can be improved even if the weight-average molecular weight of the polyurethane resin is 50,000 or more.

[0226] Specific numerical values ​​of the blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(numerical values ​​defined as "not more than" or "less than") or lower limit values ​​(numerical values ​​defined as "not less than" or "exceeding") of the corresponding 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.

[0227] <Component details> IPDI: Isophorone diisocyanate, manufactured by Evonik H １２ MDI: Dicyclohexylmethane diisocyanate, manufactured by Evonik TMXDI: 1,3-bis(2-isocyanato-2-propyl)benzene, manufactured by Tokyo Chemical Industry Co., Ltd. 1,3-H ６ XDI: 1,3-bis(isocyanatomethyl)cyclohexane, manufactured by Mitsui Chemicals, 1,4-H ６XDI: 1,4-bis(isocyanatomethyl)cyclohexane, manufactured by Mitsui Chemicals HDI: hexamethylene diisocyanate, manufactured by Tosoh PDI: pentamethylene diisocyanate, manufactured by Mitsui Chemicals XDI: xylylene diisocyanate, manufactured by Mitsui Chemicals TDI: toluene diisocyanate, manufactured by Mitsui Chemicals MDI: diphenylmethane diisocyanate, manufactured by Mitsui Chemicals UH-200: polycarbonate diol (molecular weight 2000), manufactured by Ube Industries UH-50: polycarbonate diol (molecular weight 500), manufactured by Ube Industries C-2090: polycarbonate diol (molecular weight 2000), manufactured by Kuraray PTMG-2000: polytetramethylene ether glycol (molecular weight 2000), manufactured by Mitsubishi Chemical P-2020: Polyester polyol (reaction product of terephthalic acid and 3-methyl-1,5-pentanediol), manufactured by Kuraray Co., Ltd. DMPA: Dimethylolpropionic acid, manufactured by Perstorp Co., Ltd. TEA: Triethylamine, manufactured by Wako Pure Chemical Industries, Ltd. EDA: 1,2-ethylenediamine, manufactured by Wako Pure Chemical Industries, Ltd. BDA: 1,4-butanediamine, manufactured by Wako Pure Chemical Industries, Ltd. HDA: 1,6-hexamethylenediamine, manufactured by Wako Pure Chemical Industries, Ltd. HYD·H ２ O: Hydrazine monohydrate, manufactured by Wako Pure Chemical Industries, Ltd. IPDA: Isophoronediamine, manufactured by Wako Pure Chemical Industries, Ltd. EEDA: N-ethylethylenediamine, manufactured by Tokyo Chemical Industry Co., Ltd. AEAE: 2-(2-aminoethylamino)ethanol, manufactured by Wako Pure Chemical Industries, Ltd. DETA: Diethylenetriamine, manufactured by Wako Pure Chemical Industries, Ltd. TETRA: Triethylenetetramine, manufactured by Wako Pure Chemical Industries, Ltd. DAMDEA: 2,2-diamino-N-methyldiethylamine, manufactured by Tokyo Chemical Industry Co., Ltd. TAEA: Tris(2-aminoethyl)amine, manufactured by Tokyo Chemical Industry Co., Ltd. AEP: N-(2-aminoethyl)piperazine, manufactured by Tokyo Chemical Industry Co., Ltd. AN: Acetonitrile THF: Tetrahydrofuran AC: Acetone

[0228] <Preparation of Polyurethane Dispersion> Example 1 A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube was charged with 271.9 parts by mass of UH-200, 7.7 parts by mass of DMPA (a hydrophilic group-containing active hydrogen compound), and 79.3 parts by mass of acetonitrile. Next, 60.2 parts by mass of IPDI (a polyisocyanate component) was added, and a urethane-forming reaction was carried out at 80°C until the isocyanate group concentration reached 1.6% by mass, thereby obtaining an isocyanate group-terminated prepolymer (a reaction liquid containing an isocyanate group-terminated prepolymer).

[0229] Next, 266.2 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.

[0230] Next, 726.1 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.

[0231] Next, 22.1 parts by mass of a 20% by mass aqueous solution of ethylenediamine (4.4 parts by mass as ethylenediamine) was added to the aqueous dispersion of the isocyanate group-terminated prepolymer, and then the mixture was allowed to react for 1 hour.

[0232] Next, acetonitrile was distilled off under reduced pressure at 50° C., and ion-exchanged water was added to prepare a polyurethane dispersion (solid content: 35% by mass).

[0233] Examples 2 to 44 and Comparative Examples 2 to 6 Polyurethane dispersions (solid content 35% by mass) were prepared according to the same procedure as in Example 1. However, the formulations were changed according to Tables 1 to 12.

[0234] Comparative Example 1 A water-soluble urethane resin UR8 described in JP-A No. 2022-93959 was prepared.

[0235] <Evaluation> [Acid value] The acid value of the polyurethane dispersion of each Example and Comparative Example was calculated from the charging ratio of the raw material components. Specifically, the acid value was calculated based on the following formula (1). The results are shown in Tables 1 to 12. 56100 / {(mass of polyisocyanate component + mass of polyol component + mass of neutralizing agent + mass of chain extender) / (number of moles of carboxyl groups derived from hydrophilic group-containing active hydrogen compound)} (1)

[0236] [Urethane Urea Group Concentration] The sum of the urethane group concentration and urea group concentration of the polyurethane dispersion of each Example and Comparative Example was calculated from the charging ratio of the raw material components. Specifically, the sum of the urethane group concentration and urea group concentration of the polyurethane dispersion was calculated based on the following formula (2). The results are shown in Tables 1 to 12. {59 × (number of moles of hydroxyl groups derived from the polyol component) + 58 × (number of moles of amino groups having active hydrogen groups derived from the chain extender)} / (mass of polyisocyanate component + mass of polyol component + mass of neutralizing agent + mass of chain extender) × 100 (2)

[0237] [Filterability] 20 mL of the polyurethane dispersion (solid content concentration 35% by mass) of each Example and Comparative Example was sucked into a syringe and extruded with a 0.45 μm or 0.80 μm syringe filter attached, and the filtration rate was calculated. In other words, the filtration rate when the entire 20 mL could be extruded was 100%. The results are shown in Tables 1 to 12.

[0238] [Tackiness] 7.0 g of the polyurethane dispersion (solid content concentration 35% by mass) of each Example and Comparative Example was spread evenly on a disposable PP tray (150 × 105 × 19 mm) and subjected to heat treatment at 110°C for 1 hour to form a coating film with a thickness of approximately 200 µm.

[0239] The resulting coating films were inspected by touch. The tackiness was evaluated according to the following criteria. The results are shown in Tables 1 to 12. {Criteria} 3: No stickiness was felt. 2: Slight stickiness was felt. 1: Stickiness was felt.

[0240] [Texture] Kanakin No. 3 (100% cotton) fabric was cut into a size of 210 mm lengthwise and 30 mm widthwise to prepare a woven fabric.

[0241] Next, 34.3 g of the polyurethane dispersion (solid content concentration 35% 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 37.7 g of water were mixed to prepare an ink composition.

[0242] Next, the fabric was impregnated with the ink composition, and about 1.5 g of the ink composition was soaked into the fabric. Thereafter, the fabric was heat-treated at 150° C. for 10 minutes. This gave a printed item.

[0243] The printed textile was observed with a touch. The texture was evaluated according to the following criteria. The results are shown in Tables 1 to 12. {Criteria} 3: Felt slightly flexible. 2: Felt slightly hard. 1: Hard.

[0244] [Fastness (Color Transfer)] Kanakin No. 3 was cut into a piece measuring 50 mm in length and 50 mm in width, and moistened with distilled water to prepare a white friction cloth.

[0245] The printed fabric and the white cloth for friction used in the evaluation of texture were attached to a No. 428 Gakushin-type abrasion tester (Yasuda Seiki Seisakusho Co., Ltd., Friction Tester Type II), and tested under a load of 200 g, a swing width of 100 mm, and 100 reciprocal cycles (30 cycles / min).

[0246] The obtained white friction cloth was measured for its L value (the higher the value, the whiter the cloth and the less the degree of contamination) 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 more. Color transfer was evaluated according to the following criteria. The results are shown in Tables 1 to 12. (Criteria) 3: The L value was 75 or more. 2: The L value was 70 or more but less than 75. 1: The L value was 70 or less.

[0247]

[0248]

[0249]

[0250]

[0251]

[0252]

[0253]

[0254]

[0255]

[0256]

[0257]

[0258]

[0259] The above invention is provided as an exemplary embodiment of the present invention, but this is merely an example and should not be interpreted as 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.

[0260] The polyurethane dispersion and ink composition of the present invention can be suitably used, for example, when printing fabrics.

Claims

1. 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 weight average molecular weight of the polyurethane resin is 50,000 or more, the polyisocyanate component is (A) below and the chain extender is (F) below, or the polyisocyanate component is (A) below and the chain extender is (G) below, or the polyisocyanate component is (A) below and the chain extender is (H) below, or the polyisocyanate component is (B) below and the chain extender is (G) below, or A polyurethane dispersion, wherein the polyisocyanate component is the following (C) and the chain extender is the following (G), or the polyisocyanate component is the following (D) and the chain extender is the following (G), or the polyisocyanate component is the following (E) and the chain extender is the following (H).(A) Polyisocyanate component A containing at least one selected from the group consisting of an alicyclic polyisocyanate having a secondary isocyanate group, an alicyclic polyisocyanate having a tertiary isocyanate group, an araliphatic polyisocyanate having a secondary isocyanate group, and an araliphatic polyisocyanate having a tertiary isocyanate group; (B) Polyisocyanate component B containing an alicyclic polyisocyanate having only primary isocyanate groups; (C) Polyisocyanate component C containing an aliphatic polyisocyanate having only primary isocyanate groups; (D) Polyisocyanate component D containing an araliphatic polyisocyanate having only primary isocyanate groups; (E) Polyisocyanate component E containing an aromatic polyisocyanate; and (F) Chain extender F containing a polyamine having only primary amino groups, with one carbon atom bonded to the carbon at the α-position of the primary amino group. (G) Chain extender G containing hydrazine and at least one selected from the group consisting of a polyamine having only a primary amino group and having two or more carbon atoms bonded to the carbon at the α-position of the primary amino group, a polyamine having a secondary amino group, and a polyamine having a tertiary amino group. (H) Chain extender H consisting of water.

2. The polyurethane dispersion according to claim 1, wherein the polyisocyanate component is (A) above and the chain extender is (F) above, or the polyisocyanate component is (A) above and the chain extender is (G) above, or the polyisocyanate component is (B) below and the chain extender is (F) below, or the polyisocyanate component is (B) above and the chain extender is (G) above.

3. The polyurethane dispersion according to claim 1, wherein the polyurethane resin has an acid value of 6.5 mg KOH / g to 15.0 mg KOH / g.

4. The polyurethane dispersion according to claim 1, wherein the weight average molecular weight of the polyurethane resin is 200,000 or more.

5. An ink composition comprising the polyurethane dispersion according to any one of claims 1 to 4.

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