Anionic prepolymer, anionic polyurethane, and water-based polyurethane composition containing the anionic polyurethane

Abstract

To provide an anionic prepolymer useful for preparing an aqueous polyurethane composition that is excellent in dispersion stability, and adhesion and corrosion resistance.SOLUTION: An anionic prepolymer is a product of reaction between an alkylene glycol group-containing prepolymer represented by general formula (1), and an anionic compound having an active hydrogen group with a molecular weight of less than 500, the anionic prepolymer having an acid value of 0.1-30 mgKOH / g (where R1-R3 independently represent a C4 to 13 divalent hydrocarbon group, R4 is a C2 to 4 alkylene group, R5 is a C1 to 8 alkyl group, n is a number selected from 1-100).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an anionic prepolymer, an anionic polyurethane, and a water-based polyurethane composition containing the anionic polyurethane. [Background technology]

[0002] Polyurethane compositions are widely used in a variety of applications, such as paints, adhesives, fiber sizing agents, synthetic leather, impregnation agents for substrates, and backing materials, because they can produce coating films and molded articles with properties such as abrasion resistance, adhesion, non-stickiness, and rubber elasticity. In recent years, the use of aqueous polyurethane compositions has increased due to safety concerns, such as concerns about environmental pollution and occupational health. For example, Patent Document 1 proposes an aqueous polyurethane obtained by reacting a specific alkylene oxide addition polymer with an organic diisocyanate compound. Patent Document 2 proposes an aqueous polyurethane emulsion in which a polyurethane resin obtained by reacting a divalent active hydrogen-containing compound having a specific structure with an organic polyisocyanate is dispersed in water. However, such aqueous polyurethane compositions have the problem of being inferior in physical properties, such as water resistance, heat resistance, and tensile properties, compared to solvent-based or solvent-free polyurethane compositions.

[0003] To solve the above problems, for example, Patent Document 3 proposes an aqueous polyurethane dispersion in which a polyurethane component having a functional group capable of generating a silanol group upon hydrolysis and a polyoxyalkylene skeleton having an oxyethylene unit as a hydrophilic skeleton is dispersed in water. Furthermore, Patent Document 4 proposes a nonionic water-dispersed polyurethane composition that uses an NH group-containing silane compound and has a specific nonionic group in the side chain, and that has excellent adhesion to substrates and storage stability. However, even this aqueous polyurethane composition lacks practical properties, such as dispersion stability, adhesion, and corrosion resistance, that are required for use as a coating, adhesive, fiber sizing agent, synthetic leather, impregnation agent for substrates, etc. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-53661 [Patent Document 2] Japanese Patent Application Publication No. 11-106733 [Patent Document 3] Japanese Patent Application Publication No. 11-60939 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-256048 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide an aqueous polyurethane composition having excellent dispersion stability, adhesion, and corrosion resistance, and an anionic prepolymer and an anionic polyurethane useful for preparing the aqueous polyurethane composition. [Means for solving the problem]

[0006] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by an anionic prepolymer obtained by reacting a specific alkylene glycol group-containing prepolymer with a specific anionic compound, and have arrived at the present invention. That is, the present invention provides an anionic prepolymer having an acid value of 0.1 to 30 mgKOH / g, which is obtained by reacting an alkylene glycol group-containing prepolymer represented by the following general formula (1) with an anionic compound having an active hydrogen group and a molecular weight of less than 500.

[0007] [ka]

[0008] (In the formula, R 1 ~R 3 each independently represents a divalent hydrocarbon group having 4 to 13 carbon atoms, and R 4 represents an alkylene group having 2 to 4 carbon atoms, and R5 represents an alkyl group having 1 to 8 carbon atoms, and n represents a number from 1 to 100. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an anionic prepolymer that is useful for preparing an aqueous polyurethane composition that is excellent in dispersion stability, adhesion, and corrosion resistance. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Alkylene glycol group-containing prepolymer> The alkylene glycol group-containing prepolymer used in the present invention is represented by the following general formula (1).

[0011] [ka]

[0012] In general formula (1), R 1 ~R 3 each independently represents a divalent hydrocarbon group having 4 to 13 carbon atoms. Examples of such groups include linear alkylene groups having 4 to 13 carbon atoms, branched alkylene groups having 4 to 13 carbon atoms, divalent alicyclic hydrocarbon groups having 4 to 13 carbon atoms, and divalent aromatic hydrocarbon groups having 6 to 13 carbon atoms. In particular, from the viewpoint of obtaining an aqueous polyurethane composition having excellent dispersion stability, adhesion, and corrosion resistance, R 1 ~R 3 are each independently preferably a linear alkylene group having 4 to 13 carbon atoms or a branched alkylene group having 4 to 13 carbon atoms, more preferably a linear alkylene group having 4 to 10 carbon atoms or a branched alkylene group having 4 to 10 carbon atoms, and even more preferably a linear alkylene group having 4 to 8 carbon atoms. 1 ~R 3 may be the same group or different groups. From the viewpoint of obtaining an aqueous polyurethane composition having better dispersion stability, adhesion, and corrosion resistance, R 1 ~R 3are preferably the same group.

[0013] In general formula (1), R 4 represents an alkylene group having 2 to 4 carbon atoms. Examples of such groups include an alkylene group having 2 carbon atoms, a linear alkylene group having 3 carbon atoms, a branched alkylene group having 3 carbon atoms, a linear alkylene group having 4 carbon atoms, and a branched alkylene group having 4 carbon atoms. In particular, from the viewpoint of obtaining an aqueous polyurethane composition having excellent dispersion stability, adhesion, and corrosion resistance, R 4 is preferably an alkylene group having 2 carbon atoms, a linear alkylene group having 3 carbon atoms, or a branched alkylene group having 3 carbon atoms, and more preferably an alkylene group having 2 carbon atoms.

[0014] In general formula (1), R 5 represents an alkyl group having 1 to 8 carbon atoms. Examples of such groups include linear alkyl groups having 1 to 8 carbon atoms and branched alkyl groups having 3 to 8 carbon atoms. In particular, from the viewpoint of obtaining an aqueous polyurethane composition having superior dispersion stability, adhesion, and corrosion resistance, R 5 is preferably a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and even more preferably an alkyl group having 1 carbon atom.

[0015] In general formula (1), n ​​represents a number from 1 to 100. From the viewpoint of obtaining an aqueous polyurethane composition having better dispersion stability, adhesion, and corrosion resistance, n is preferably from 5 to 80, more preferably from 10 to 60, and even more preferably from 10 to 40.

[0016] The alkylene glycol group-containing prepolymer used in the present invention can be produced by known methods. However, from the viewpoint of ease of production and the various properties of the resulting anionic prepolymer and anionic polyurethane, it is preferred to produce it by reacting a trimer (isocyanurate compound) obtained by cyclic trimerization of a compound having two or more isocyanate groups in the molecule with an alkylene glycol compound having an alkylene glycol group and a group reactive with an isocyanate group in the molecule.

[0017] Examples of trimers (isocyanurate compounds) obtained by cyclic trimerization of compounds having two or more isocyanate groups in the molecule that can be used in producing alkylene glycol group-containing prepolymers include cyclic trimers of aliphatic diisocyanate compounds having a linear or branched alkylene group with 4 to 13 carbon atoms, cyclic trimers of alicyclic diisocyanate compounds having an alicyclic hydrocarbon group with 4 to 13 carbon atoms, and cyclic trimers of aromatic diisocyanate compounds having an aromatic hydrocarbon group with 6 to 13 carbon atoms. Additionally, cyclic compounds of two or three diisocyanate compounds selected from the group consisting of aliphatic diisocyanate compounds having a linear or branched alkylene group with 4 to 13 carbon atoms, alicyclic diisocyanate compounds having an alicyclic hydrocarbon group with 4 to 13 carbon atoms, and aromatic diisocyanate compounds having an aromatic hydrocarbon group with 6 to 13 carbon atoms can also be used. Among these, from the viewpoint of ease of production and the properties of the resulting anionic prepolymer and anionic polyurethane, it is preferable to use a cyclic trimer of an aliphatic diisocyanate compound having a linear or branched alkylene group with 4 to 13 carbon atoms, it is more preferable to use a cyclic trimer of an aliphatic diisocyanate compound having a linear or branched alkylene group with 4 to 10 carbon atoms, and it is even more preferable to use a cyclic trimer of an aliphatic diisocyanate compound having a linear alkylene group with 4 to 8 carbon atoms.

[0018] Examples of alkylene glycol compounds that can be used to produce alkylene glycol group-containing prepolymers include alkylene glycol compounds having an alkylene glycol group, such as an ethylene glycol group, a propylene glycol group, a tetramethylene glycol group, or a butylene glycol group, in the molecule, and a group reactive with an isocyanate group, such as a hydroxyl group, an amino group, or a carboxyl group. Among these, from the viewpoint of the various properties of the resulting anionic prepolymer and anionic polyurethane, it is preferable to use an alkylene glycol compound having an alkylene glycol group and a hydroxyl group in the molecule, and it is more preferable to use an alkylene glycol compound having an ethylene glycol group and a hydroxyl group in the molecule. Examples of alkylene glycol compounds having an ethylene glycol group and a hydroxyl group in the molecule include polyethylene glycols having a number average molecular weight of 200 to 10,000 and derivatives thereof, and compounds represented by the following general formula (2):

[0019] [ka]

[0020] In general formula (2), a represents a number of 5 to 50. From the viewpoint of the properties of the resulting anionic prepolymer and anionic polyurethane, a is preferably 10 to 40, more preferably 10 to 30, and even more preferably 15 to 25.

[0021] In general formula (2), b represents a number of 0 to 4. From the viewpoint of the properties of the resulting anionic prepolymer and anionic polyurethane, b is preferably 0 to 2, more preferably 1 or 2, and even more preferably 1.

[0022] In general formula (2), c represents a number of 0 to 2. From the viewpoint of the properties of the resulting anionic prepolymer and anionic polyurethane, c is preferably 0 or 1, and more preferably 1.

[0023] In general formula (2), d represents a number of 1 to 3. From the viewpoint of the properties of the resulting anionic prepolymer and anionic polyurethane, d is preferably 1 or 2, and more preferably 1.

[0024] In general formula (2), x represents a number of 0 to 2. From the viewpoint of the properties of the resulting anionic prepolymer and anionic polyurethane, x is preferably 0 or 1, and more preferably 1.

[0025] In general formula (2), y represents a number from 1 to 3. From the viewpoint of the properties of the resulting anionic prepolymer and anionic polyurethane, y is preferably 2 or 3, and more preferably 2. In general formula (2), the sum of x and y is 3.

[0026] From the viewpoint of easily producing the alkylene glycol group-containing prepolymer represented by general formula (1), it is preferable to use an alkylene glycol compound having an alkylene glycol group, a group reactive with an isocyanate group, and an alkoxy group in the molecule. In particular, from the viewpoint of obtaining an aqueous polyurethane composition having better dispersion stability, adhesion, and corrosion resistance, it is more preferable to use a methoxypolyethylene glycol having a number average molecular weight of 200 to 10,000 or an ethoxypolyethylene glycol having a number average molecular weight of 200 to 10,000 as the alkylene glycol compound, even more preferably a methoxypolyethylene glycol having a number average molecular weight of 200 to 10,000, and most preferably a methoxypolyethylene glycol having a number average molecular weight of 300 to 5,000.

[0027] In producing the alkylene glycol group-containing prepolymer, the method for reacting the isocyanurate compound with the alkylene glycol compound is not particularly limited, and known methods can be used. Examples of such methods include a method in which the isocyanurate compound and the alkylene glycol compound are mixed in a solvent or without a solvent at a temperature of 30°C to 160°C, preferably 40°C to 160°C, under a pressurized environment, a reduced pressure environment, or a normal pressure environment, and maintained for 10 minutes to 20 hours until the reaction is completed.

[0028] The ratio of the isocyanurate compound and the alkylene glycol compound when reacted is not particularly limited, but from the viewpoint of the various properties of the resulting alkylene glycol group-containing prepolymer, the isocyanurate compound and the alkylene glycol compound are preferably used in amounts such that the ratio of the number of isocyanate groups in the isocyanurate compound to the number of hydroxyl groups in the alkylene glycol compound is 3:0.2 to 3:2.0, more preferably 3:0.5 to 3:1.5, and even more preferably 3:0.8 to 3:1.2.

[0029] <Anionic compounds> The anionic compound having an active hydrogen group and a molecular weight of less than 500 that can be used in the present invention is not limited to compounds having an active hydrogen group such as a hydroxyl group, amino group, imino group, urethane group, or urea group, and an anionic group such as a carboxyl group, sulfo group, or phosphate group in the molecule, and having a molecular weight of less than 500. Examples of such anionic compounds having an active hydrogen group and a molecular weight of less than 500 include anionic compounds having an active hydrogen group and a carboxyl group in the molecule and a molecular weight of less than 500, anionic compounds having an active hydrogen group and a sulfo group in the molecule and a molecular weight of less than 500, and anionic compounds having an active hydrogen group and a phosphate group in the molecule and a molecular weight of less than 500. These anionic compounds may be used alone or in combination of two or more. In the present invention, among these, from the viewpoint of the various properties of the resulting anionic prepolymer and anionic polyurethane, it is preferable to use at least one selected from the group consisting of anionic compounds having an active hydrogen group and a carboxyl group in the molecule and a molecular weight of less than 500, and anionic compounds having an active hydrogen group and a sulfo group in the molecule and a molecular weight of less than 500, and it is more preferable to use at least one selected from the group consisting of anionic compounds having a hydroxyl group and a carboxyl group in the molecule and a molecular weight of less than 500, anionic compounds having an amino group and a carboxyl group in the molecule and a molecular weight of less than 500, anionic compounds having a hydroxyl group and a sulfo group in the molecule and a molecular weight of less than 500, and anionic compounds having an amino group and a sulfo group in the molecule and a molecular weight of less than 500. In the present invention, the use of such an anionic compound makes it possible to adjust the content and distribution of anionic groups in the resulting anionic prepolymer and anionic polyurethane, thereby enabling the production of an anionic prepolymer and anionic polyurethane with excellent properties.

[0030] Examples of anionic compounds having an active hydrogen group and a carboxyl group in the molecule and a molecular weight of less than 500 include dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolvaleric acid, hydroxyacetic acid, hydroxypropanoic acid, hydroxypivalic acid, dihydroxysuccinic acid, lysine, arginine, and cystine. These anionic compounds may be used alone or in combination of two or more. Among these anionic compounds, from the viewpoint of obtaining an aqueous polyurethane composition having superior dispersion stability, adhesion, and corrosion resistance, it is preferable to use at least one selected from the group consisting of dimethylolpropionic acid, dimethylolbutanoic acid, and dimethylolvaleric acid, and it is more preferable to use at least one selected from the group consisting of dimethylolpropionic acid and dimethylolbutanoic acid.

[0031] Examples of anionic compounds having an active hydrogen group and a sulfo group in the molecule and a molecular weight of less than 500 include 2-aminoethanesulfonic acid, 2-methylaminoethanesulfonic acid, 2-(cyclohexylamino)-ethanesulfonic acid, 3-(cyclohexylamino)-propanesulfonic acid, 4-aminotoluene-2-sulfonic acid, 5-aminotoluene-2-sulfonic acid, 2-aminonaphthalene-4-sulfonic acid, 4-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 1,3-phenylpropanesulfonic acid, 2-aminoethane ... Examples of the anionic compounds include phenylenediamine-4,6-disulfonic acid, diaminobutanesulfonic acid, diaminopropanesulfonic acid, 3,6-diamino-2-toluenesulfonic acid, 2,4-diamino-5-toluenesulfonic acid, N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(2-aminoethyl)-2-aminobutanesulfonic acid, N,N-bis(2-hydroxyethyl)-2-aminobutanesulfonic acid, and N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid. These anionic compounds may be used alone or in combination of two or more. Among these anionic compounds, from the viewpoint of obtaining an aqueous polyurethane composition having superior dispersion stability, adhesion, and corrosion resistance, it is preferable to use at least one selected from the group consisting of N,N-bis(2-hydroxyethyl)-2-aminobutanesulfonic acid and N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid, and it is more preferable to use N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid.

[0032] Among these anionic compounds, it is particularly preferable to use dimethylolpropionic acid, dimethylolbutanoic acid, or a mixture thereof, or N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid, from the viewpoint of obtaining an aqueous polyurethane composition having better dispersion stability, adhesion, and corrosion resistance.

[0033] <Anionic prepolymer> The anionic prepolymer of the present invention is obtained by reacting an alkylene glycol group-containing prepolymer with an anionic compound having an active hydrogen group and a molecular weight of less than 500, and has an acid value of 0.1 to 30 mgKOH / g. The anionic prepolymer of the present invention has such an acid value, making it possible to prepare an aqueous polyurethane composition having excellent dispersion stability, adhesion, and corrosion resistance. If the acid value is less than 0.1 mgKOH / g or more than 30 mgKOH / g, the resulting aqueous polyurethane composition may have poor dispersion stability, adhesion, and corrosion resistance, or the production of the anionic polyurethane may be difficult due to poor dispersibility in aqueous solution. In the present invention, from the viewpoint of obtaining an aqueous polyurethane composition having even better dispersion stability, adhesion, and corrosion resistance, the acid value is preferably 0.2 to 25 mgKOH / g, more preferably 0.3 to 20 mgKOH / g, and most preferably 1.0 to 15 mgKOH / g. In the present invention, the acid value of the anionic prepolymer is a value measured as the amount (mg) of potassium hydroxide required to neutralize 1 g of the anionic prepolymer, and is measured, for example, by titration with an aqueous potassium hydroxide solution.

[0034] In the present invention, the ratio of the alkylene glycol group-containing prepolymer to the anionic compound having an active hydrogen group and a molecular weight of less than 500 when reacting them is not particularly limited. However, from the viewpoint of obtaining an aqueous polyurethane composition having excellent dispersion stability, adhesion, and corrosion resistance, the alkylene glycol group-containing prepolymer and the anionic compound having an active hydrogen group and a molecular weight of less than 500 are preferably used in amounts such that the ratio of the number of isocyanate groups in the alkylene glycol group-containing prepolymer to the number of active hydrogen groups in the anionic compound having an active hydrogen group and a molecular weight of less than 500 is 1:0.50 to 1:0.85, more preferably 1:0.55 to 1:0.80, and even more preferably 1:0.60 to 1:0.75.

[0035] The anionic prepolymer of the present invention may be one obtained by reacting only an alkylene glycol group-containing prepolymer with an anionic compound having an active hydrogen group and a molecular weight of less than 500, or may be one obtained by reacting an alkylene glycol group-containing prepolymer with an anionic compound having an active hydrogen group and a molecular weight of less than 500, and further with a polyol compound, an isocyanate compound, or the like, depending on the purpose and application.

[0036] The polyol compound that may be used in producing the anionic prepolymer of the present invention is not particularly limited, and examples thereof include low-molecular-weight polyols, polycarbonate polyols, polyether polyols, silicone polyols, polyester polyols, and polyester carbonate polyols. These polyol compounds may be used alone or in combination of two or more.

[0037] Examples of low molecular weight polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, Examples of the diol include aliphatic diols such as 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, diethylene glycol, and triethylene glycol; alicyclic diols such as cyclohexanedimethanol and cyclohexanediol; and trihydric or higher alcohols such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, pentaerythritol, and tetramethylolpropane.

[0038] Polycarbonate polyols are obtained by reacting, for example, a carbonate ester and / or phosgene with a low-molecular-weight polyol. Examples of the carbonate ester include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, diphenyl carbonate, dinaphthyl carbonate, and phenyl naphthyl carbonate.

[0039] Examples of polyether polyols include propylene oxide adducts of low molecular weight polyols, polytetramethylene glycol, and the like.

[0040] Examples of silicone polyols include silicone oils having siloxane bonds in the molecule and hydroxyl groups at the terminals.

[0041] Examples of polyester polyols include compounds obtained by a direct esterification reaction and / or a transesterification reaction between a low-molecular-weight polyol and a polycarboxylic acid or an ester-forming derivative thereof, such as an ester, anhydride, or halide, in an amount less than the stoichiometric amount of the low-molecular-weight polyol. Examples of polycarboxylic acids or ester-forming derivatives thereof include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, 2-methylsuccinic acid, 2-methyladipic acid, 3-methyladipic acid, 3-methylpentanedioic acid, 2-methyloctanedioic acid, 3,8-dimethyldecanedioic acid, 3,7-dimethyldecanedioic acid, hydrogenated dimer acid, and dimer acid; aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclopentanedicarboxylic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, 1,4-dicarboxylmethylenecyclohexane, nadic acid, and methylnadic acid; polycarboxylic acids such as tricarboxylic acids such as trimellitic acid, trimesic acid, and the trimer of castor oil fatty acid; acid anhydrides of these polycarboxylic acids; halides such as chlorides and bromides of the polycarboxylic acids; lower esters such as methyl esters, ethyl esters, propyl esters, isopropyl esters, butyl esters, isobutyl esters, and amyl esters of the polycarboxylic acids; and lactones such as γ-caprolactone, δ-caprolactone, ε-caprolactone, dimethyl-ε-caprolactone, δ-valerolactone, γ-valerolactone, and γ-butyrolactone.

[0042] Examples of polyester carbonate polyols include those obtained by reacting polyester polyol with a carbonate ester and / or phosgene.

[0043] In the present invention, from the viewpoint of various properties of the resulting anionic prepolymer and anionic polyurethane, it is preferable that the anionic prepolymer is obtained by reacting an alkylene glycol group-containing prepolymer with an anionic compound having an active hydrogen group and a molecular weight of less than 500, and a polyol compound. From the viewpoint of obtaining an aqueous polyurethane composition having better dispersion stability and adhesion, it is preferable to use, as the polyol compound, at least one polyol having a number average molecular weight of 200 to 10,000, more preferably at least one selected from the group consisting of polyether polyols having a number average molecular weight of 200 to 10,000 and polyester polyols having a number average molecular weight of 200 to 10,000, even more preferably at least one selected from the group consisting of polyether polyols having a number average molecular weight of 300 to 5,000 and polyester polyols having a number average molecular weight of 300 to 5,000, and most preferably at least one polyester polyol having a number average molecular weight of 300 to 5,000.

[0044] The ratio of the raw materials used when reacting the alkylene glycol group-containing prepolymer, the anionic compound having an active hydrogen group and a molecular weight of less than 500, and the polyol compound is not particularly limited, but from the viewpoint of obtaining an aqueous polyurethane composition with better dispersion stability and adhesion, the anionic compound having an active hydrogen group and a molecular weight of less than 500 and the polyol compound are preferably used in amounts such that the ratio of the number of active hydrogen groups in the anionic compound having an active hydrogen group and a molecular weight of less than 500 to the number of active hydrogen groups in the polyol compound is 10:90 to 99:1, more preferably 15:85 to 90:10, and even more preferably 20:80 to 80:20. Furthermore, from the viewpoint of obtaining an aqueous polyurethane composition with superior dispersion stability and adhesion, the alkylene glycol group-containing prepolymer, the anionic compound having active hydrogen groups and a molecular weight of less than 500, and the polyol compound are used in amounts such that the ratio of the number of isocyanate groups in the alkylene glycol group-containing prepolymer to the sum of the number of active hydrogen groups in the anionic compound having active hydrogen groups and a molecular weight of less than 500 and the number of active hydrogen groups in the polyol compound is preferably 1:0.50 to 1:0.85, more preferably 1:0.55 to 1:0.80, and even more preferably 1:0.60 to 1:0.75.

[0045] The isocyanate compound that may be used in producing the anionic prepolymer of the present invention is not particularly limited as long as it is a compound having an isocyanate group in the molecule, and examples thereof include diisocyanate compounds having two isocyanate groups in the molecule (excluding alkylene glycol group-containing prepolymers represented by general formula (1)), and polyisocyanate compounds having three or more isocyanate groups in the molecule.

[0046] Examples of diisocyanate compounds having two isocyanate groups in the molecule include aromatic diisocyanate compounds such as tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, dianisidine diisocyanate, and tetramethylxylylene diisocyanate; isophorone diisocyanate; Examples of the diisocyanate include alicyclic diisocyanate compounds such as diisocyanate, cyclohexylmethane-4,4'-diisocyanate, trans-1,4-cyclohexane diisocyanate, cis-1,4-cyclohexane diisocyanate, and norbornene diisocyanate; aliphatic diisocyanate compounds such as 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate; and mixtures thereof.

[0047] Examples of polyisocyanate compounds having three or more isocyanate groups in the molecule include tri- or higher functional compounds such as triphenylmethane triisocyanate, 1-methylbenzene-2,4,6-triisocyanate, and dimethyltriphenylmethane tetraisocyanate, as well as modified and blocked compounds thereof, and isocyanurate trimers and biuret trimers of the aforementioned diisocyanates.

[0048] In the present invention, from the viewpoint of the various properties of the resulting anionic prepolymer and anionic polyurethane, the anionic prepolymer is preferably one obtained by reacting an alkylene glycol group-containing prepolymer with an anionic compound having an active hydrogen group and a molecular weight of less than 500, and an isocyanate compound. From the viewpoint of obtaining an aqueous polyurethane composition having better dispersion stability and adhesion, it is preferable to use, as the isocyanate compound, at least one selected from the group consisting of aromatic diisocyanate compounds, alicyclic diisocyanate compounds, and aliphatic diisocyanate compounds, it is more preferable to use at least one selected from the group consisting of alicyclic diisocyanate compounds and aliphatic diisocyanate compounds, and it is even more preferable to use at least one aliphatic diisocyanate compound.

[0049] The ratio of the raw materials used when reacting the alkylene glycol group-containing prepolymer, the anionic compound having an active hydrogen group and a molecular weight of less than 500, and the isocyanate compound is not particularly limited, but from the viewpoint of obtaining an aqueous polyurethane composition with excellent dispersion stability and adhesion, the alkylene glycol group-containing prepolymer and the isocyanate compound are preferably used in amounts such that the ratio of the number of isocyanate groups in the alkylene glycol group-containing prepolymer to the number of isocyanate groups in the isocyanate compound is 90:10 to 1:99, more preferably 50:50 to 1:99, and even more preferably 30:70 to 2:98. Furthermore, from the viewpoint of obtaining an aqueous polyurethane composition with superior dispersion stability and adhesion, the alkylene glycol group-containing prepolymer, the anionic compound having active hydrogen groups and a molecular weight of less than 500, and the isocyanate compound are preferably used in amounts such that the ratio of the sum of the number of isocyanate groups in the alkylene glycol group-containing prepolymer and the number of isocyanate groups in the isocyanate compound to the number of active hydrogen groups in the anionic compound having active hydrogen groups and a molecular weight of less than 500 is 1:0.50 to 1:0.85, more preferably 1:0.55 to 1:0.80, and even more preferably 1:0.60 to 1:0.75.

[0050] In the present invention, from the viewpoint of the various properties of the anionic prepolymer and anionic polyurethane obtained, it is more preferable that the anionic prepolymer be one obtained by reacting an alkylene glycol group-containing prepolymer, an anionic compound having an active hydrogen group and a molecular weight of less than 500, a polyol compound, and an isocyanate compound. The ratio of each raw material used when reacting an alkylene glycol group-containing prepolymer, an anionic compound having an active hydrogen group and a molecular weight of less than 500, a polyol compound, and an isocyanate compound is not particularly limited. However, from the viewpoint of obtaining an aqueous polyurethane composition having excellent dispersion stability, adhesion, and corrosion resistance, it is preferable to use each raw material in an amount such that the ratio of the sum of the number of isocyanate groups in the alkylene glycol group-containing prepolymer and the number of isocyanate groups in the isocyanate compound to the sum of the number of active hydrogen groups in the anionic compound having an active hydrogen group and a molecular weight of less than 500 and the number of active hydrogen groups in the polyol compound is 1:0.50 to 1:0.85, more preferably 1:0.55 to 1:0.80, and even more preferably 1:0.60 to 1:0.75. From the viewpoint of obtaining an aqueous polyurethane composition having better dispersion stability and adhesion, the anionic compound having an active hydrogen group and a molecular weight of less than 500 and the polyol compound are used in amounts such that the ratio of the number of active hydrogen groups in the anionic compound having an active hydrogen group and a molecular weight of less than 500 to the number of active hydrogen groups in the polyol compound is preferably 10:90 to 99:1, more preferably 15:85 to 90:10, and even more preferably 20:80 to 80:20. Furthermore, from the viewpoint of obtaining an aqueous polyurethane composition with better dispersion stability and adhesion, the alkylene glycol group-containing prepolymer and the isocyanate compound are used in amounts such that the ratio of the number of isocyanate groups in the alkylene glycol group-containing prepolymer to the number of isocyanate groups in the isocyanate compound is preferably 90:10 to 1:99, more preferably 50:50 to 1:99, and even more preferably 30:70 to 2:98.

[0051] The anionic prepolymer of the present invention has, in its molecular structure, an alkylene glycol group derived from an alkylene glycol group-containing prepolymer. Due to this structure, the anionic prepolymer of the present invention has excellent dispersion stability. Furthermore, due to this structure, the anionic prepolymer of the present invention can be used to prepare an aqueous polyurethane composition having excellent dispersion stability, adhesion, and corrosion resistance. In the present invention, from the viewpoint of obtaining an aqueous polyurethane composition having even more excellent adhesion and corrosion resistance, the content of the alkylene glycol group derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer is preferably 1 to 40 mass%, more preferably 3 to 30 mass%, even more preferably 5 to 25 mass%, and most preferably 10 to 20 mass%. In the present invention, the content of alkylene glycol groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer is expressed as the total content of alkylene glycol groups, such as ethylene glycol groups, propylene glycol groups, butylene glycol groups, and tetramethylene glycol groups, derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer, and does not include alkylene glycol groups derived from polyol compounds, etc. other than the alkylene glycol group-containing prepolymer that can be used during production.

[0052] From the viewpoint of facilitating the preparation of an aqueous polyurethane composition excellent in dispersion stability, adhesion, and corrosion resistance, the anionic prepolymer of the present invention preferably has a sum (X+Y) of the content X [mass%] of alkylene glycol groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer and the acid value Y [mgKOH / g] of the anionic prepolymer, of 3 to 50. In the present invention, when X+Y is within this range, the contents of alkylene glycol groups and anionic groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer become appropriate, making it easy to prepare an aqueous polyurethane composition excellent in all of dispersion stability, adhesion, and corrosion resistance. From the viewpoint of obtaining an aqueous polyurethane composition having better dispersion stability, adhesion, and corrosion resistance, the sum (X+Y) of the content X [mass%] of alkylene glycol groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer and the acid value Y [mgKOH / g] of the anionic prepolymer is more preferably 5 to 40, even more preferably 10 to 30, and most preferably 12 to 25.

[0053] From the viewpoint of facilitating the preparation of an aqueous polyurethane composition excellent in dispersion stability, adhesion, and corrosion resistance, the anionic prepolymer of the present invention preferably has a ratio (X:Y) of the content X [mass%] of alkylene glycol groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer to the acid value Y [mgKOH / g] of the anionic prepolymer, of 1:0.01 to 1:20. In the present invention, when X:Y is in this range, the ratio of alkylene glycol groups derived from the alkylene glycol group-containing prepolymer to anionic groups in the anionic prepolymer becomes appropriate, making it easy to prepare an aqueous polyurethane composition excellent in all of dispersion stability, adhesion, and corrosion resistance. From the viewpoint of obtaining an aqueous polyurethane composition having better dispersion stability, adhesion, and corrosion resistance, the ratio (X:Y) of the content X [mass%] of alkylene glycol groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer to the acid value Y [mgKOH / g] of the anionic prepolymer is more preferably 1:0.02 to 1:10, even more preferably 1:0.1 to 1:5, and most preferably 1:0.15 to 1:1.

[0054] Furthermore, in the anionic prepolymer of the present invention, when X+Y and X:Y are within the above-mentioned ranges, the configuration of the alkylene glycol groups and anionic groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer is optimized, and it is therefore easy to prepare an aqueous polyurethane composition having better dispersion stability, adhesion, and corrosion resistance, which is preferable.

[0055] The anionic prepolymer of the present invention is obtained by reacting an isocyanate group in an alkylene glycol group-containing prepolymer represented by general formula (1), an active hydrogen group in an anionic compound having an active hydrogen group and a molecular weight of less than 500, an isocyanate group in an isocyanate compound used as needed, and an active hydrogen group in a polyol compound used as needed. Therefore, it is impossible or almost impractical to directly specify the structure of the anionic prepolymer of the present invention by the general formula or the like.

[0056] The conditions for producing the anionic prepolymer of the present invention are not particularly limited. For example, the anionic prepolymer of the present invention can be produced by charging the alkylene glycol group-containing prepolymer represented by general formula (1), an anionic compound having an active hydrogen group and a molecular weight of less than 500, an isocyanate compound used as needed, and a polyol compound used as needed into a reaction vessel all at once or in multiple batches, and mixing and reacting them under an environment of room temperature to 180°C and 0.01 Pa to 100 MPa for 10 minutes to 24 hours. The solvent that can be used in producing the anionic prepolymer is not particularly limited as long as it is a known solvent that is inert to the respective raw materials. Examples include hydrocarbon solvents such as toluene and xylene; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as ethyl acetate, butyl acetate, and pentyl acetate; ether solvents such as dioxane and dibutyl ether; glycol ester solvents such as propylene glycol monomethyl ether acetate; amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; and dimethyl sulfoxide. Among these solvents, solvents with high affinity for water are preferred from the viewpoint of facilitating the production of an anionic prepolymer with excellent properties. Specifically, at least one solvent selected from the group consisting of acetone, methyl ethyl ketone, dioxane, and N-methyl-2-pyrrolidone is preferred. The amount of solvent used is not particularly limited, but is preferably 10 to 80 parts by mass, and more preferably 20 to 70 parts by mass, per 100 parts by mass of the total amount of the raw materials used in producing the anionic prepolymer.

[0057] In the production of the anionic prepolymer of the present invention, a known catalyst may be used as needed to facilitate the reaction between the isocyanate group and the active hydrogen group in the raw material. Examples of such catalysts include N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, N,N,N',N'',N''-pentamethyl-(3-aminopropyl)ethylenediamine, N,N,N',N'',N''-pentamethyldipropylenetriamine, and N,N,N',N'-tetramethylguanidine. , 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-S-triazine, 1,8-diazabicyclo[5.4.0]undecene-7, triethylenediamine, N,N,N',N'-tetramethylhexamethylenediamine, N-methyl-N'-(2-dimethylaminoethyl)piperazine, N,N'-dimethylpiperazine, dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, bis(2-dimethylaminoethyl)piperazine tertiary amines such as methylaminoethyl) ether, N,N-dimethyllaurylamine, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, and 1-dimethylaminopropylimidazole; quaternary ammonium salts such as tetraalkylammonium halides such as tetramethylammonium chloride, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide salt, and tetraalkylammonium organic acid salts such as tetramethylammonium 2-ethylhexanoate; and organometallic catalysts such as stannous diacetate, stannous dioctoate, stannous dioleate, stannous dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dioctyltin dilaurate, lead octoate, lead naphthenate, nickel naphthenate, and cobalt naphthenate. Among these catalysts, organometallic catalysts are preferred, and dibutyltin dilaurate or dioctyltin dilaurate is more preferred, from the viewpoint that the reaction between the isocyanate group and the active hydrogen group proceeds smoothly and the resulting anionic prepolymer and anionic polyurethane are less likely to yellow.These catalysts may be used alone or in combination of two or more. The amount of catalyst used is not particularly limited, but is preferably 0.001 to 1 part by mass, and more preferably 0.01 to 0.1 part by mass, per 100 parts by mass of the total amount of the raw materials used in producing the anionic prepolymer.

[0058] The anionic prepolymer of the present invention may be used in any manner, but is preferably used as a prepolymer for preparing an anionic polyurethane, as described below. Anionic polyurethane can be obtained by further reacting the anionic prepolymer of the present invention with a chain extender. Aqueous polyurethane compositions containing the anionic polyurethane thus obtained are preferred because they have excellent dispersion stability, adhesion, and corrosion resistance.

[0059] <Anionic polyurethane> The anionic polyurethane of the present invention is obtained by reacting the above-mentioned anionic prepolymer with a chain extender. Examples of the chain extender that can be used in the present invention include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, triethylene glycol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, and 3-methyl-2,4-pentanediol. Aliphatic diols such as 1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, and 1,9-nonanediol; alicyclic diols such as cyclohexanedimethanol and cyclohexanediol; ethylenediamine, propylenediamine, and hexanediol. low molecular weight diamines such as samethylenediamine, tolylenediamine, piperazine, and 2-methylpiperazine; polyalkylenepolyamines such as diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, and 2-(2-aminoethylamino)ethanol; polyether diamines such as polyoxypropylenediamine and polyoxyethylenediamine; alicyclic diamines such as menthenediamine, isophoronediamine, norbornenediamine, aminoethylaminoethanol, bis(4-amino-3-methyldicyclohexyl)methane, diaminodicyclohexylmethane, bis(aminomethyl)cyclohexane, and 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro(5,5)undecane;Examples of suitable aromatic diamines include polyamines such as m-xylenediamine, α-(m / p-aminophenyl)ethylamine, m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodimethyldiphenylmethane, diaminodiethyldiphenylmethane, dimethylthiotoluenediamine, diethyltoluenediamine, and α,α'-bis(4-aminophenyl)-p-diisopropylbenzene; hydrazines such as succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide, hydrazine hydrate, 1,6-hexamethylenebis(N,N-dimethylsemicarbazide), and 1,1,1',1'-tetramethyl-4,4'-(methylene-di-para-phenylene)disemicarbazide; and water. Among these chain extenders, from the viewpoint of ease of reaction and various properties of the resulting anionic polyurethane, it is preferable to use at least one selected from the group consisting of diamines, hydrazines, and water, and it is more preferable to use at least one selected from the group consisting of ethylenediamine, adipic acid dihydrazide, hydrazines, and water.

[0060] In the present invention, the amount of chain extender used when reacting the anionic prepolymer with the chain extender is not particularly limited. However, from the viewpoint of obtaining an aqueous polyurethane composition having superior dispersion stability, adhesion, and corrosion resistance, the amount is preferably such that the equivalent ratio of active hydrogen groups in the chain extender to one equivalent of isocyanate groups in the anionic prepolymer is 0.2 or more, more preferably 0.5 or more, and even more preferably 1.0 or more. The upper limit of the amount of chain extender used is not particularly limited. When a chain extender other than water is used, the amount is preferably such that the equivalent ratio of active hydrogen groups in the chain extender to one equivalent of isocyanate groups in the anionic prepolymer is 10 or less, more preferably 5 or less, and even more preferably 3 or less. Furthermore, when water is used as the chain extender, since water can also be used as a solvent, the upper limit of the amount of water used is not particularly limited. For example, 10,000 parts by mass or less of water can be used per 100 parts by mass of the anionic prepolymer. When water and one or more chain extenders other than water are used in combination as the chain extender, the amount is preferably such that the equivalent ratio of active hydrogen groups in the chain extender other than water to 1 equivalent of isocyanate groups in the anionic prepolymer is 10 or less, more preferably 5 or less, and even more preferably 3 or less. In this case, the upper limit of the amount of water used is not particularly limited, but for example, 10,000 parts by mass or less of water can be used per 100 parts by mass of the anionic prepolymer. When water and a chain extender other than water are used in combination as the chain extender, the isocyanate groups in the anionic prepolymer usually react preferentially with the active hydrogen groups in the chain extender other than water, so that after all of the active hydrogen groups in the chain extender other than water have reacted with the isocyanate groups in the anionic prepolymer, the remaining isocyanate groups in the anionic prepolymer react with water.

[0061] In the present invention, when an anionic prepolymer and a chain extender are reacted to produce an anionic polyurethane, it is preferable to use a neutralizing agent to neutralize the anionic groups. Examples of neutralizing agents include trialkylamines such as trimethylamine, triethylamine, and tributylamine; N,N-dialkylalkanolamines such as N,N-dimethylethanolamine, N,N-dimethylpropanolamine, N,N-dipropylethanolamine, and 1-dimethylamino-2-methyl-2-propanol; tertiary amine compounds such as N-alkyl-N,N-dialkanolamines and trialkanolamines such as triethanolamine; and cationic compounds such as ammonia, trimethylammonium hydroxide, sodium hydroxide, potassium hydroxide, and lithium hydroxide. These neutralizing agents may be used alone or in combination of two or more. The amount of neutralizing agent used is not particularly limited, but is preferably an amount such that the equivalent ratio of cationic groups in the neutralizing agent to 1 equivalent of anionic groups in the anionic prepolymer is 0.2 or more, more preferably 0.5 or more, and even more preferably 1.0 or more.

[0062] In the anionic polyurethane of the present invention, some of the isocyanate groups in the anionic prepolymer may be blocked with a blocking agent. Examples of blocking agents that can be used in the present invention include alcohols such as methanol and ethanol; dialkylamines such as diethylamine, dimethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, didodecylamine, and distearylamine; diarylamines such as diphenylamine; and secondary amino group-containing heterocyclic compounds such as morpholine, piperidine, pyrrole, pyrrolidine, pyrazole, and imidazole. The amount of blocking agent used is not particularly limited, but can be, for example, an amount such that the number of groups in the blocking agent that can react with isocyanate groups relative to the number of isocyanate groups in the anionic prepolymer is an equivalent ratio of 0.01 to 2.0.

[0063] In addition, when reacting the anionic prepolymer with the chain extender, a solvent and a catalyst may be used as necessary. Examples of the solvent and catalyst that can be used here include the same solvents and catalysts that can be used in the production of the anionic prepolymer described above. In addition, the solvent and catalyst used in the production of the anionic prepolymer can be used as they are.

[0064] The method for producing the anionic polyurethane of the present invention is not particularly limited, but examples thereof include the following production methods. (1) A mixture of an anionic prepolymer or an anionic prepolymer solution (excluding aqueous solutions) and a neutralizer is added to an aqueous solution containing an emulsifier as needed and dispersed (prepolymer mixing method). (2) An aqueous solution containing a neutralizer and, if necessary, an emulsifier is added to an anionic prepolymer or an anionic prepolymer solution (excluding aqueous solutions) and dispersed (phase inversion method). (3) The anionic prepolymer dispersed in water by the method (1) or (2) is chain-extended in water using a chain extender and, if necessary, a blocking agent.

[0065] The anionic polyurethane of the present invention is obtained by further reacting an anionic prepolymer, the structure of which cannot be directly specified by a general formula or the like, or is practically impossible, with a chain extender and, if necessary, a blocking agent. Therefore, like the anionic prepolymer, the structure of the anionic polyurethane of the present invention is also impossible or practically impossible to directly specify by a general formula or the like.

[0066] The weight-average molecular weight of the anionic polyurethane of the present invention is not particularly limited and may be, for example, 5,000 to 1,000,000, and preferably 10,000 to 100,000. The weight-average molecular weight of the anionic polyurethane in the present invention is measured by GPC (gel permeation chromatography) and calculated in terms of standard polystyrene.

[0067] The acid value of the anionic polyurethane of the present invention is not particularly limited, but from the viewpoint of facilitating the preparation of an aqueous polyurethane composition excellent in dispersion stability, adhesion, and corrosion resistance, it is preferably 0.1 to 30 mgKOH / g, more preferably 0.2 to 25 mgKOH / g, even more preferably 0.3 to 20 mgKOH / g, and most preferably 1.0 to 15 mgKOH / g. In the present invention, the acid value of the anionic polyurethane is a value measured as the amount (mg) of potassium hydroxide required to neutralize 1 g of the anionic polyurethane, and is measured, for example, by titration with an aqueous potassium hydroxide solution.

[0068] <Water-based polyurethane composition> The aqueous polyurethane composition of the present invention contains the anionic polyurethane and water. In the present invention, the term "aqueous" refers to a state in which the polyurethane is dispersed or dissolved in a solvent containing water, and the dispersion in this case also includes a state in which a resin is emulsified in water, such as an emulsion.

[0069] The solid content (anionic polyurethane content) in the aqueous polyurethane composition of the present invention is not particularly limited, but from the viewpoints of dispersion stability, adhesion, and corrosion resistance, it is preferably 10 to 70 mass%, more preferably 20 to 60 mass%. In the present invention, the solid content is calculated using the mass after weighing 1 g of the aqueous polyurethane composition into an aluminum cup and drying it in a thermostatic bath at 150°C for 1 hour.

[0070] In the aqueous polyurethane composition of the present invention, the content ratio of water relative to the total amount of solvent is not particularly limited and can be adjusted depending on the application or purpose. From the viewpoint of the dispersion stability of the aqueous polyurethane composition, the content ratio of water relative to the total amount of solvent is preferably 20 to 100 mass%, more preferably 40 to 100 mass%, and even more preferably 60 to 100 mass%.

[0071] The state of the aqueous polyurethane composition of the present invention is not particularly limited, and examples thereof include emulsion, suspension, colloidal dispersion, and aqueous solution. The particle size of the anionic polyurethane in the aqueous polyurethane composition is not particularly limited, but from the viewpoint of dispersion stability, it is preferably 100 μm or less, more preferably 10 μm or less, even more preferably 1 μm or less, and most preferably 100 nm or less. In the present invention, the particle size of the anionic polyurethane in the aqueous polyurethane composition is measured using a dynamic scattering method.

[0072] Various additives may be added to the aqueous polyurethane composition of the present invention depending on the intended use and required properties. Specific examples of such additives include hindered amine light stabilizers, ultraviolet absorbers, phosphorus-based antioxidants, phenolic antioxidants, sulfur-based antioxidants, organic solvents, emulsifiers, crosslinking agents, silane coupling agents, inorganic colloidal sols such as colloidal silica and colloidal alumina, tetraalkoxysilanes and their condensation polymers, chelating agents, epoxy compounds, pigments, dyes, film-forming aids, curing agents, viscosity modifiers, leveling agents, antifoaming agents, anticoagulants, radical scavengers, heat resistance-imparting agents, inorganic or organic fillers, plasticizers, lubricants, fluorine-based or siloxane-based antistatic agents, reinforcing agents, catalysts, thixotropes, waxes, antifogging agents, antibacterial agents, antifungal agents, antiseptics, and rust inhibitors.

[0073] Examples of the hindered amine light stabilizer include 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6,6-tetramethyl-4-piperidyl benzoate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, 1,2,2,6,6-pentamethyl-4-piperidylmethyl methacrylate, 2,2,6,6-tetramethyl-4-piperidylmethyl methacrylate, tetramethyl-4-piperidylmethyl benzoate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, 1,2,2,6,6-pentamethyl-4-piperidylmethyl methacrylate, tetramethyl-4-piperidylmethyl benzoate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidylmethyl benzoate), ... Kis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, bis(2,2,6,6-tetramethyl-4-piperidyl)·bis(tridecyl)-1,2,3,4-butanetetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)·bis(tridecyl)-1,2,3,4-butanetetracarboxylate, bis(1,2,2,6,6-pentamethyl-4- piperidyl)-2-butyl-2-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate, 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol / diethyl succinate polycondensate, 1,6-bis(2,2,6,6-pentamethyl-4-piperidylamino)hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate, 1,6-bis(2,2,6,6-pentamethyl-4-piperidylamino)hexane / 2,4-dichloro-6-tert-octylamino-s-triazine polycondensate, 1,5,8,12-[2,4 -bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazin-6-yl)-1,5,8,12-tetraazadodecane, 1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazin-6-yl]-1,5,8,12-tetraazadodecane, 1,6,11-tris[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazin-6-ylamino]undecane, 1,6,Examples include 11-tris[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazin-6-ylamino]undecane, 3,9-bis[1,1-dimethyl-2-(tris(2,2,6,6-tetramethyl-4-piperidyloxycarbonyloxy)butylcarbonyloxy)ethyl]-2,4,8,10-tetraoxyspiro[5.5]undecane, and 3,9-bis[1,1-dimethyl-2-(tris(1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyloxy)butylcarbonyloxy)ethyl]-2,4,8,10-tetraoxyspiro[5.5]undecane.

[0074] Examples of the ultraviolet absorber include 2-hydroxybenzophenones such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis(2-hydroxy-4-methoxybenzophenone); 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2-hydroxy-3,5-ditert-butylphenyl)-5-chlorobenzotriazole, and 2-(2-hydroxy-3- 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-dicumylphenyl)benzotriazole, 2,2'-methylenebis(4-tert-octyl-6-benzotriazolylphenol), polyethylene glycol ester of 2-(2-hydroxy-3-tert-butyl-5-carboxyphenyl)benzotriazole, 2-[2-hydroxy-3-(2-acryloyloxyethyl)-5-methylphenyl]benzotriazole, 2-[2-hydroxy-3-(2-methacryloyloxyethyl)-5-tert-butylphenyl]benzotriazole phenyl]benzotriazole, 2-[2-hydroxy-3-(2-methacryloyloxyethyl)-5-tert-octylphenyl]benzotriazole, 2-[2-hydroxy-3-(2-methacryloyloxyethyl)-5-tert-butylphenyl]-5-chlorobenzotriazole, 2-[2-hydroxy-5-(2-methacryloyloxyethyl)phenyl]benzotriazole, 2-[2-hydroxy-3-tert-butyl-5-(2-methacryloyloxyethyl)phenyl]benzotriazole, 2-[2-hydroxy-3-tert-amyl-5-(2-methacryloyloxyethyl)phenyl]benzotriazole 2-(2-hydroxyphenyl)benzotriazoles such as 2-[2-hydroxy-3-tert-butyl-5-(3-methacryloyloxypropyl)phenyl]benzotriazole, 2-[2-hydroxy-4-(methacryloyloxymethyl)phenyl]benzotriazole, 2-[2-hydroxy-4-(3-methacryloyloxy-2-hydroxypropyl)phenyl]benzotriazole, and 2-[2-hydroxy-4-(3-methacryloyloxypropyl)phenyl]benzotriazole;2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-hexyloxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-octoxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(3-C12-13 mixed alkoxy-2-hydroxypropoxy)phenyl]-4,6-bis(2,4-dimethylphenyl) 2-(2-hydroxyphenyl)-4,6-diaryl-1,3,5-triazine such as 2-[2-hydroxy-4-(2-acryloyloxyethoxy)phenyl]-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxy-3-allylphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2,4,6-(2-hydroxy-3-methyl-4-hexyloxyphenyl)-1,3,5-triazine. Azines; phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate, octyl-3,5-di-tert-butyl-4-hydroxybenzoate, dodecyl-3,5-di-tert-butyl-4-hydroxybenzoate, tetradecyl-3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl-3,5-di-tert-butyl-4-hydroxybenzoate Benzoates such as 2-ethyl-2'-ethoxyoxanilide and behenyl-3,5-di-tert-butyl-4-hydroxybenzoate; substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide and 2-ethoxy-4'-dodecyloxanilide; cyanoacrylates such as ethyl-α-cyano-β,β-diphenylacrylate and methyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate; and various metal salts or metal chelates, particularly nickel or chromium salts or chelates.

[0075] Examples of phosphorus-based antioxidants include triphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris(2,5-di-tert-butylphenyl) phosphite, tris(nonylphenyl) phosphite, tris(dinonylphenyl) phosphite, tris(mono- and di-mixed nonylphenyl) phosphite, diphenyl acid phosphite, 2,2'-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, diphenyl decyl phosphite, diphenyl octyl phosphite, bis(nonylphenyl) (2,4-ditert-butylphenyl)pentaerythritol phosphite, phenyl diisodecyl phosphite, tributyl phosphite, tris(2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite, dibutyl acid phosphite, dilauryl acid phosphite, trilauryl trithiophosphite, bis(neopentyl glycol)·1,4-dicyclohexanedimethyl diphosphite, bis(2,4-ditert-butylphenyl)pentaerythritol diphosphite, bis(2,6-ditert-butyl-4-methylphenyl) phenyl) pentaerythritol diphosphite, bis(2,4-dicumylphenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tetra(C12-15 mixed alkyl)-4,4-isopropylidenediphenyl phosphite, bis[2,2'-methylenebis(4,6-diamylphenyl)]isopropylidenediphenyl phosphite, tetratridecyl-4,4'-butylidenebis(2-tert-butyl-5-methylphenol) diphosphite, hexa(tridecyl)-1,1,3-tris( Examples include 2-methyl-5-tert-butyl-4-hydroxyphenyl)butane triphosphite, tetrakis(2,4-ditert-butylphenyl)biphenylene diphosphonite, tris(2-[(2,4,8,10-tetrakistert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl)amine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 2-butyl-2-ethylpropanediol-2,4,6-tritert-butylphenol monophosphite.

[0076] Examples of phenolic antioxidants include 2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, distearyl (3,5-di-tert-butyl-4-hydroxybenzyl) phosphonate, tridecyl 3,5-di-tert-butyl-4-hydroxybenzyl thioacetate, thiodiethylene bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 4,4'-thiobis(6-tert-butyl-m- cresol), 2-octylthio-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-s-triazine, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butylic acid]glycol ester, 4,4'-butylidenebis(6-tert-butyl-3-methylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, bis[2-tert-butyl-4-methyl-6-(2-hydroxy- 3-tert-butyl-5-methylbenzyl)phenyl] terephthalate, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl] isocyanurate, tetrakis[methylene- Examples include 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, 2-tert-butyl-4-methyl-6-(2-acroyloxy-3-tert-butyl-5-methylbenzyl)phenol, 3,9-bis[2-(3-tert-butyl-4-hydroxy-5-methylhydrocinnamoyloxy)-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, and triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate].

[0077] Examples of sulfur-based antioxidants include dialkyl thiodipropionates such as dilauryl, dimyristyl, myristylstearyl, and distearyl esters of thiodipropionic acid, and β-alkyl mercaptopropionic acid esters of polyols such as pentaerythritol tetra(β-dodecylmercaptopropionate).

[0078] Examples of organic solvents include ketones such as methyl ethyl ketone, methyl amyl ketone, diethyl ketone, acetone, methyl isopropyl ketone, and cyclohexanone; ethers such as tetrahydrofuran, 1,2-dimethoxyethane, and 1,2-diethoxyethane; esters such as ethyl acetate and n-butyl acetate; alcohols such as iso- or n-butanol, iso- or n-propanol, and amyl alcohol; ether alcohols such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated aliphatic hydrocarbons such as carbon tetrachloride, chloroform, trichloroethylene, and methylene chloride; halogenated aromatic hydrocarbons such as chlorobenzene; aniline, triethylamine, pyridine, dioxane, acetic acid, acetonitrile, and carbon disulfide.

[0079] Examples of the emulsifier include known surfactants such as known anionic surfactants and nonionic surfactants, cationic surfactants such as primary amine salts, secondary amine salts, tertiary amine salts, quaternary amine salts, and pyridinium salts, and amphoteric surfactants such as betaine-type, sulfate ester-type, and sulfonic acid-type.

[0080] Examples of anionic surfactants include alkyl sulfates such as sodium dodecyl sulfate, potassium dodecyl sulfate, and ammonium dodecyl sulfate; polyoxyethylene ether sulfates such as sodium dodecyl polyglycol ether sulfate and ammonium polyoxyethylene alkyl ether sulfate; ammonium salts of alkyl sulfonates such as sodium sulforicinoleate, alkali metal salts of sulfonated paraffin, and ammonium salts of sulfonated paraffin; fatty acid salts such as sodium laurate, triethanolamine oleate, and triethanolamine abietate; alkylaryl sulfonates such as sodium benzenesulfonate and alkali metal sulfates of alkali phenol hydroxyethylene; high alkyl naphthalene sulfonate, naphthalene sulfonate-formaldehyde condensate, dialkyl sulfosuccinate, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkylaryl sulfate salts, polyoxyethylene ether phosphate salts, polyoxyethylene alkyl ether acetate salts, N-acyl amino acid salts, and N-acyl methyl taurine salts.

[0081] Examples of nonionic surfactants include fatty acid partial esters of polyhydric alcohols such as sorbitan monolaurate and sorbitan monooleate; polyoxyethylene glycol fatty acid esters; polyglycerin fatty acid esters; ethylene oxide and / or propylene oxide adducts of C1-18 alcohols; ethylene oxide and / or propylene oxide adducts of alkylphenols; ethylene oxide and / or propylene oxide adducts of alkylene glycols and / or alkylenediamines, etc. Examples of C1-18 alcohols that constitute nonionic surfactants include methanol, ethanol, propanol, 2-propanol, butanol, 2-butanol, tert-butanol, amyl alcohol, isoamyl alcohol, tert-amyl alcohol, hexanol, octanol, decane alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, and stearyl alcohol.

[0082] Examples of alkylphenols that constitute nonionic surfactants include phenol, methylphenol, 2,4-di-tert-butylphenol, 2,5-di-tert-butylphenol, 3,5-di-tert-butylphenol, 4-(1,3-tetramethylbutyl)phenol, 4-isooctylphenol, 4-nonylphenol, 4-tert-octylphenol, 4-dodecylphenol, 2-(3,5-dimethylheptyl)phenol, 4-(3,5-dimethylheptyl)phenol, naphthol, bisphenol A, and bisphenol F.

[0083] Examples of alkylene glycols constituting the nonionic surfactant include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, and 1,6-hexanediol. Examples of alkylene diamines include those in which the alcoholic hydroxyl groups of these alkylene glycols are substituted with amino groups. Furthermore, the ethylene oxide and propylene oxide adducts may be random adducts or block adducts.

[0084] Examples of cationic surfactants include lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, distearyldimethylammonium chloride, didecyldimethylammonium chloride, laurylbenzyldimethylammonium chloride, didecyldimethylammonium chloride, alkylpyridinium bromide, and imidazolinium laurate.

[0085] Examples of amphoteric surfactants include betaine surfactants such as coconut oil fatty acid amidopropyl dimethyl acetate betaine, lauryl dimethyl amino acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxymethyl imidazolinium betaine, lauryl hydroxysulfobetaine, lauroyl amidoethyl hydroxyethyl carboxymethyl betaine, and metal salts of hydroxypropyl phosphate; amino acid surfactants such as metal salts of β-lauryl aminopropionic acid; sulfate ester surfactants; and sulfonic acid surfactants.

[0086] When various additives are blended into the aqueous polyurethane composition of the present invention, the blending amounts can be adjusted appropriately. For example, 0.001 to 20 parts by mass of each additive can be blended per 100 parts by mass of the solids content of the aqueous polyurethane composition. However, from the viewpoints of safety and environmental impact, the blending amount of organic solvent is preferably 0 to 80% by mass, more preferably 0 to 60% by mass, and even more preferably 0 to 40% by mass, relative to the total amount of solvent (total amount of water and organic solvent). In this case, the method of adding the various additives is not limited, and they can be blended by known methods.

[0087] The aqueous polyurethane composition of the present invention can be used in a variety of applications where polyurethanes are used, including, for example, coatings or adhesives for concrete, cement mortar, various metals, leather, glass, etc.; adhesives for packaging tapes, labels, frozen food labels, removable labels, POS labels, adhesive wallpaper, and adhesive flooring materials; paper treatment agents for processed paper such as art paper, coated paper, lightweight coated paper, cast-coated paper, coated paperboard, carbonless copiers, and impregnated paper; fiber treatment agents such as sizing agents, anti-fray agents, and processing agents for natural fibers, synthetic fibers, glass fibers, carbon fibers, and metal fibers; building materials such as sealants, cement admixtures, and waterproofing materials; sponges, puffs, gloves, and condoms. Among these, the aqueous polyurethane composition of the present invention is preferably used as a coating composition or adhesive composition because of its excellent adhesion to various substrates. When the aqueous polyurethane composition of the present invention is used as a coating material, it can be applied to a substrate by an appropriate method, such as brush coating, roller coating, spray coating, gravure coating, reverse roll coating, air knife coating, bar coating, curtain roll coating, dip coating, rod coating, or doctor blade coating. [Example]

[0088] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples and may be changed without departing from the scope of the present invention. In the following examples, % is by mass unless otherwise specified.

[0089] The raw materials used in producing the anionic prepolymer and the anionic polyurethane are listed below.

[0090] <Isocyanate compounds> Isocyanate Compound 1: Isocyanurate Trimer of Hexamethylene Diisocyanate Isocyanate compound 2: 4,4'-dicyclohexylmethane diisocyanate

[0091] <Alkylene glycol compounds> Alkylene glycol compound 1: Methoxypolyethylene glycol with a number average molecular weight of 1000 Alkylene glycol compound 2: Methoxypolyethylene glycol with a number average molecular weight of 400 Alkylene glycol compound 3: Methoxypolyethylene glycol with a number average molecular weight of 4000 Alkylene glycol compound 4: Polyethylene glycol with a number average molecular weight of 1000 Alkylene glycol compound 5: a compound in which, in general formula (2), a is 20 to 22, b is 1, c is 1, d is 1, x is 1, and y is 2

[0092] <Polyol compounds> Polyol compound 1: polyester polyol having a number average molecular weight of 500 (ADEKA Corporation, Adeka New Ace F1212-5)

[0093] <Anionic compounds> Anionic compound 1: Dimethylolpropionic acid (molecular weight 134.13) Anionic compound 2: Dimethylolbutanoic acid (molecular weight 148.16) Anionic compound 3: N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (molecular weight 229.25)

[0094] <Solvent> Solvent 1: N-methyl-2-pyrrolidone (abbreviated as NMP) Solvent 2: Water

[0095] <Amine compounds> Amine compound 1: Triethylamine (neutralizer) Amine compound 2: Ethylenediamine (chain extender)

[0096] Example 1 To a four-neck separable round-bottom flask equipped with a Dimroth stirrer, stirring blade, and nitrogen line, 59.2 g of an isocyanurate trimer of hexamethylene diisocyanate (isocyanate compound 1) as an isocyanate compound and 104.1 g of methoxypolyethylene glycol (alkylene glycol compound 1) with a number average molecular weight of 1000 as an alkylene glycol compound were added, and the mixture was allowed to react at 100°C for 5 hours with stirring and mixing to obtain an alkylene glycol group-containing prepolymer. Here, the entire amount of the isocyanate compound and alkylene glycol compound used reacted, and in general formula (1), R 1 ~R 3 are each a linear alkylene group having 6 carbon atoms, and R 4 is an alkylene group having 2 carbon atoms, and R 5 was an alkylene glycol group-containing prepolymer in which n was 25 and n was an alkylene glycol group-containing prepolymer. Next, 302.6 g of a polyester polyol (polyol compound 1) having a number average molecular weight of 500 as a polyol compound, 225.2 g of 4,4'-dicyclohexylmethane diisocyanate (isocyanate compound 2) as an isocyanate compound, 5.0 g of dimethylolpropionic acid (anionic compound 1) as an anionic compound, and 303.4 g of N-methyl-2-pyrrolidone (solvent 1) as a solvent were added, and the mixture was reacted with the alkylene glycol group-containing prepolymer at 90 ° C. for 5 hours while stirring and mixing to obtain an NMP solution containing anionic prepolymer 1. The acid value of anionic prepolymer 1 was 1.5 mg KOH / g, and the content of ethylene glycol groups derived from the alkylene glycol group-containing prepolymer in anionic prepolymer 1 was 15.0 mass%.

[0097] <Examples 2 to 15> Each alkylene glycol group-containing prepolymer was obtained in the same manner as in Example 1, except that the types and amounts of raw materials for the alkylene glycol group-containing prepolymer used in Example 1 were changed as shown in Tables 1 to 3. Here, the entire amounts of the isocyanate compound and alkylene glycol compound used reacted to form the alkylene glycol group-containing prepolymer represented by general formula (1). Next, NMP solutions containing anionic prepolymers 2 to 15 of Examples 2 to 15 were obtained in the same manner as in Example 1, except that the types and amounts of raw materials for the anionic prepolymer used in Example 1 were changed as shown in Tables 1 to 3. The acid value of each anionic prepolymer and the content of ethylene glycol groups derived from each alkylene glycol group-containing prepolymer are shown in Tables 1 to 3.

[0098] <Comparative Example 1> In the same manner as in Example 1, an alkylene glycol group-containing prepolymer was obtained. Next, an NMP solution containing anionic prepolymer 16 was obtained by reacting an alkylene glycol group-containing prepolymer with a polyol compound and an isocyanate compound in the same manner as in Example 1, except that no anionic compound was used and the types and amounts of raw materials for the anionic prepolymer used in Example 1 were changed as shown in Table 3. The acid value of anionic prepolymer 16 was 0 mgKOH / g, and the content of ethylene glycol groups derived from the alkylene glycol group-containing prepolymer in anionic prepolymer 16 was 15.0 mass%.

[0099] <Comparative Example 2> An alkylene glycol group-containing prepolymer was obtained in the same manner as in Example 1, except that the types and amounts of raw materials for the alkylene glycol group-containing prepolymer used in Example 1 were changed as shown in Table 3. Here, the entire amounts of the isocyanate compound and alkylene glycol compound used reacted to form the alkylene glycol group-containing prepolymer represented by general formula (1). Next, an NMP solution containing anionic prepolymer 17 was obtained by reacting an alkylene glycol group-containing prepolymer with a polyol compound and an isocyanate compound in the same manner as in Example 1, except that no anionic compound was used and the types and amounts of raw materials for the anionic prepolymer used in Example 1 were changed as shown in Table 3. The acid value of anionic prepolymer 17 was 0 mgKOH / g, and the content of ethylene glycol groups derived from the alkylene glycol group-containing prepolymer in anionic prepolymer 17 was 30.0% by mass.

[0100] <Comparative Example 3> A four-neck separable round-bottom flask equipped with a Dimroth stirrer, a stirring blade, and a nitrogen line was charged with 266.3 g of 4,4'-dicyclohexylmethane diisocyanate (isocyanate compound 2) as an isocyanate compound, 104.3 g of a polyethylene glycol compound (alkylene glycol compound 1) having a number average molecular weight of 1000 as an alkylene glycol compound, 321.0 g of a polyester polyol (polyol compound 1) having a number average molecular weight of 500 as a polyol compound, 5.0 g of dimethylolpropionic acid (anionic compound 1) as an anionic compound, and 303.4 g of N-methyl-2-pyrrolidone (solvent 1) as a solvent, and the reaction was carried out at 90°C for 5 hours with stirring and mixing, thereby obtaining an NMP solution containing anionic prepolymer 18. The acid value of the anionic prepolymer 18 was 3.0 mgKOH / g, the content of ethylene glycol groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer 18 was 0 mass%, and the content of ethylene glycol groups derived from other raw materials was 15.0 mass%.

[0101] <Comparative Example 4> Into a four-neck separable round-bottom flask equipped with a Dimroth stirrer, a stirring blade, and a nitrogen line, 284.0 g of 4,4'-dicyclohexylmethane diisocyanate (isocyanate compound 2) as an isocyanate compound, 121.0 g of a compound (alkylene glycol compound 5) in which, in the general formula (2), a is 20 to 22, b is 1, c is 1, d is 1, x is 1, and y is 2 in general formula (2), 286.6 g of a polyester polyol (polyol compound 1) having a number average molecular weight of 500 as a polyol compound, 5.0 g of dimethylolpropionic acid (anionic compound 1) as an anionic compound, and 303.4 g of N-methyl-2-pyrrolidone (solvent 1) as a solvent were added, and the mixture was allowed to react at 90 ° C. for 5 hours with stirring and mixing, thereby obtaining an NMP solution containing anionic prepolymer 19. The acid value of the anionic prepolymer 19 was 3.0 mgKOH / g, the content of ethylene glycol groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer 19 was 0 mass%, and the content of ethylene glycol groups derived from other raw materials was 15.0 mass%.

[0102] <Comparative Example 5> A four-neck separable round-bottom flask equipped with a Dimroth stirrer, a stirring blade, and a nitrogen line was charged with 347.0 g of 4,4'-dicyclohexylmethane diisocyanate as an isocyanate compound, 316.3 g of a polyester polyol (polyol compound 1) with a number average molecular weight of 500 as a polyol compound, 33.3 g of dimethylolpropionic acid (anionic compound 1) as an anionic compound, and 303.4 g of N-methyl-2-pyrrolidone (solvent 1) as a solvent. The mixture was reacted at 90°C for 5 hours with stirring and mixing to obtain an NMP solution containing anionic prepolymer 20. The acid value of anionic prepolymer 20 was 20 mgKOH / g, and the content of ethylene glycol groups derived from the alkylene glycol group-containing prepolymer in anionic prepolymer 20 was 0% by mass.

[0103] <Comparative Example 6> An alkylene glycol group-containing prepolymer was obtained in the same manner as in Example 1, except that the types and amounts of raw materials for the alkylene glycol group-containing prepolymer used in Example 1 were changed as shown in Table 3. Here, the entire amounts of the isocyanate compound and alkylene glycol compound used reacted to form the alkylene glycol group-containing prepolymer represented by general formula (1). Next, an NMP solution containing anionic prepolymer 21 of Comparative Example 6 was obtained in the same manner as in Example 1, except that the types and amounts of the raw materials for the anionic prepolymer used in Example 1 were changed as shown in Table 3. The acid value of anionic prepolymer 21 was 40 mgKOH / g, and the content of ethylene glycol groups derived from the alkylene glycol group-containing prepolymer in anionic prepolymer 21 was 5.0 mass%.

[0104] Example 16 In a 2L disposable cup, 1000 g of water (solvent 2) and 3.5 g of triethylamine (amine compound 1) as a neutralizing agent were added and stirred. Then, 900.0 g of an NMP solution containing anionic prepolymer 1 (containing 626.9 g of anionic prepolymer 1) was added and further stirred. Next, 13.5 g of ethylenediamine (amine compound 2) was added as a chain extender, and the mixture was stirred for an additional hour to react anionic prepolymer 1 with ethylenediamine. After confirming that no unreacted isocyanate groups remained, an aqueous dispersion of anionic polyurethane 1 was obtained as a waterborne polyurethane composition. During this reaction, the isocyanate groups in anionic prepolymer 1 reacted preferentially with the chain extender ethylenediamine, and the remaining isocyanate groups reacted with water, presumably resulting in the final reaction of all isocyanate groups.

[0105] <Examples 17 to 30 and Comparative Examples 7 to 12> Aqueous dispersions of anionic polyurethanes 2 to 15, 17, 19, and 20 were obtained as aqueous polyurethane compositions in the same manner as in Example 16, except that the types and amounts of raw materials used in Example 16 were changed as shown in Tables 4 to 6. However, in Comparative Example 7, which used anionic prepolymer 16, Comparative Example 9, which used anionic prepolymer 18, and Comparative Example 12, which used anionic prepolymer 21, the anionic prepolymer precipitated during the reaction step and did not react with the chain extender, and anionic polyurethanes could not be synthesized in any of these cases. Therefore, subsequent evaluations could not be performed.

[0106] <Dispersion stability test method> To 100 parts by mass of aqueous dispersions of anionic polyurethanes 1 to 15, 17, 19, and 20 (each containing 27 to 32% by mass of anionic polyurethane), 20 parts by mass of neutral colloidal silica (ADEKA Corporation, Adelite AT-20A) was added, and the appearance was visually observed for any change. Similarly, to 100 parts by mass of aqueous dispersions of anionic polyurethanes 1 to 15, 17, 19, and 20, 20 parts by mass of acidic colloidal silica (ADEKA Corporation, Adelite CT-100) was added, and the appearance was visually observed for any change. Based on the observation results, the dispersion stability was evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 4 to 6. In this test, if the dispersion stability of the aqueous polyurethane composition was evaluated as "good," it indicated that the composition could be suitably used for various applications such as paints, adhesives, and treatment agents.

[0107] Dispersion stability evaluation criteria ○: The appearance did not change in any test and the dispersion state was maintained ×: Aggregates were formed in at least one test

[0108] <Adhesion test method> Adhesion tests were conducted on anionic polyurethanes 1-15, 17, 19, and 20 in accordance with JIS K5600-5-6 (1999). Specifically, aqueous dispersions of anionic polyurethanes 1-15, 17, 19, and 20 were each applied to a test piece (PET film). After air drying, the test piece was heated at 180°C for 10 minutes to form a 1-μm-thick coating film. The coating film on the test piece was then cut into 100 squares using a cutter guide with a 1-mm gap. Adhesive tape (CT-18, manufactured by Nichiban Co., Ltd.) was attached to the cut coating film, and the tape was then peeled off at an angle of approximately 60° relative to the peeling direction. The tape application and peeling were performed three times each, after which the number of peeled squares on the coating film on each test piece was counted, and adhesion was evaluated based on the following evaluation criteria. The evaluation results are shown in Tables 4-6.

[0109] Adhesion evaluation criteria ◎: No peeling occurred ○: Peeling occurred in 1 to 10 squares ×: Peeling occurred in 11 or more squares

[0110] <Corrosion resistance test method> Each aqueous dispersion of anionic polyurethanes 1-15, 17, 19, and 20 was applied to an untreated galvanized steel sheet, which was then placed in a 300°C atmosphere for 3 seconds, heating the steel sheet to a maximum temperature of 80°C to form a 1-μm-thick coating. The test specimens after coating were then subjected to a neutral salt spray treatment (SST) for 24 hours in accordance with JIS Z2371. The area of ​​rust on the treated test specimens was visually inspected, and corrosion resistance was evaluated based on the following criteria. The evaluation results are shown in Tables 4-6. In this test, a dispersion stability rating of Fair or better for the aqueous polyurethane composition indicated its suitability for various applications, such as paints, adhesives, and treatment agents.

[0111] Corrosion resistance evaluation criteria ◎: Rust occurs on less than 5% of the total area ○: Rust occurs on 5% to less than 40% of the total area △: Rust occurs on 40% to less than 70% of the total area ×: Rust occurs on 70% or more of the total area

[0112] [Table 1]

[0113] [Table 2]

[0114] [Table 3]

[0115] [Table 4]

[0116] [Table 5]

[0117] [Table 6]

[0118] As shown by the above results, aqueous polyurethane compositions containing anionic polyurethanes 1 to 15 produced using the anionic prepolymers of the examples exhibited excellent dispersion stability, adhesion, and corrosion resistance. In particular, aqueous polyurethane compositions containing anionic polyurethanes 1 to 15 exhibited excellent dispersion stability, adhesion, and corrosion resistance even when used in combination with acidic or neutral additives in aqueous solvents, which has previously been difficult to achieve. Therefore, aqueous polyurethane compositions containing anionic polyurethanes produced using the anionic prepolymers of the present invention can be suitably used in aqueous paints, coating agents, surface treatment agents, sealants, adhesives, pressure-sensitive adhesives, fiber sizing agents, building materials, electronic components, and the like.

Claims

1. An anionic prepolymer having an acid value of 0.1 to 30 mgKOH / g, obtained by reacting an alkylene glycol group-containing prepolymer represented by the following general formula (1), which is produced by reacting an isocyanurate compound with an alkylene glycol compound in amounts such that the ratio of the number of isocyanate groups in the isocyanurate compound to the number of hydroxyl groups in the alkylene glycol compound is 3:0.5 to 3:1.5, with an anionic compound having an active hydrogen group and a molecular weight of less than 500. 【Chemical 1】 (In the formula, R １ ~R ３ each independently represents a divalent hydrocarbon group having 4 to 13 carbon atoms; R ４ represents an alkylene group having 2 to 4 carbon atoms, R ５ represents an alkyl group having 1 to 8 carbon atoms, and n represents a number from 1 to 100.

2. 2. The anionic prepolymer according to claim 1, wherein the anionic compound is at least one selected from the group consisting of anionic compounds having an active hydrogen group and a carboxyl group in the molecule and a molecular weight of less than 500, and anionic compounds having an active hydrogen group and a sulfo group in the molecule and a molecular weight of less than 500.

3. 3. The anionic prepolymer according to claim 1, wherein the content of alkylene glycol groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer is 1 to 40% by mass.

4. The anionic prepolymer according to any one of claims 1 to 3, wherein the sum (X + Y) of the content X [mass%] of the alkylene glycol group derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer and the acid value Y [mg KOH / g] of the anionic prepolymer is 3 to 50.

5. The anionic prepolymer according to any one of claims 1 to 4, wherein the ratio (X:Y) of the content X [mass%] of alkylene glycol groups derived from the alkylene glycol group-containing prepolymer in the anionic prepolymer to the acid value Y [mg KOH / g] of the anionic prepolymer is 1:0.01 to 1:

20.

6. An anionic polyurethane obtained by reacting the anionic prepolymer according to any one of claims 1 to 5 with a chain extender.

7. A water-based polyurethane composition comprising the anionic polyurethane according to claim 6 and water.

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