Water-dispersible polyisocyanate composition, curing agent, aqueous polyurethane resin composition, two-component curable polyurethane resin composition and articles

Abstract

This water dispersion type polyisocyanate composition contains a water dispersion type polyisocyanate (A) and a non-water dispersion type polyisocyanate (B). The water dispersion type polyisocyanate (A) includes a reaction product between a first polyisocyanate component (a1) and a hydrophilic active hydrogen component (a2). The hydrophilic active hydrogen component (a2) has hydrophilic groups and an active hydrogen group. The hydrophilic groups include an anion group and / or a nonion group. The non-water dispersion type polyisocyanate (B) includes a second polyisocyanate component (b1) but does not include a reaction product between the second polyisocyanate component (b1) and a hydrophilic active hydrogen component including hydrophilic groups. The content proportion of the water dispersion type polyisocyanate (A) is 10 mass% or more.

Description

Technical Field

[0001] The present invention relates to a water-dispersible polyisocyanate composition, a curing agent, an aqueous polyurethane resin composition, a two-component curable polyurethane resin composition, and an article.

Background Art

[0002] Polyurethane resins are widely used in various industrial fields. Polyurethane resins include reaction products of a polyisocyanate component and a polyol component.

[0003] The polyisocyanate component is prepared, for example, as an organic solvent solution. In recent years, in order to improve environmental performance and workability, it has been required to prepare the polyisocyanate component as an aqueous dispersion. That is, a polyisocyanate component that can be dispersed in water has been required.

[0004] The following have been proposed as polyisocyanate components that can be dispersed in water. That is, a polyisocyanate mixture obtained by the reaction of an isocyanurate group-containing polyisocyanate produced from 1,6-diisocyanatohexane (HDI) and a monofunctional polyethylene oxide polyether (see, for example, Patent Document 1 (Example 1)).

[0005] The above polyisocyanate mixture contains polyethylene oxide units derived from the monofunctional polyethylene oxide polyether. Therefore, the polyisocyanate composition can be dispersed in water.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, depending on the application of the polyurethane resin, the solvent resistance of the polyurethane resin obtained from the above polyisocyanate composition may not be sufficient.

[0008] The present invention relates to a water-dispersible polyisocyanate composition, a curing agent, an aqueous polyurethane resin composition, a two-component curable polyurethane resin composition, and articles that can obtain a polyurethane resin having excellent solvent resistance. [Means for solving the problem]

[0009] The present invention [1] is a water-dispersible polyisocyanate composition comprising a water-dispersible polyisocyanate (A) and a non-water-dispersible polyisocyanate (B), wherein the water-dispersible polyisocyanate (A) comprises a reaction product of a first polyisocyanate component (a1) and a hydrophilic active hydrogen component (a2), the hydrophilic active hydrogen component (a2) having a hydrophilic group and an active hydrogen group, the hydrophilic group comprising an anionic group and / or a nonionic group, and The non-aqueous dispersible polyisocyanate (B) contains a second polyisocyanate component (b1), does not contain the reaction product of the second polyisocyanate component (b1) and the hydrophilic active hydrogen component (a2), and the content of the aqueous dispersible polyisocyanate (A) is 10% by mass or more relative to the total amount of the aqueous dispersible polyisocyanate (A) and the non-aqueous dispersible polyisocyanate (B), and the aqueous dispersible polyisocyanate composition contains this aqueous dispersible polyisocyanate composition.

[0010] The present invention [2] includes the water-dispersible polyisocyanate composition described in [1] above, wherein the content of the water-dispersible polyisocyanate (A) is less than 40% by mass of the total amount of the water-dispersible polyisocyanate (A) and the non-water-dispersible polyisocyanate (B).

[0011] The present invention [3] comprises a water-dispersible polyisocyanate composition according to [1] or [2] above, wherein the first polyisocyanate component (a1) comprises a derivative of a linear aliphatic polyisocyanate.

[0012] The present invention [4] comprises a water-dispersible polyisocyanate composition according to any one of the above [1] to [3], wherein the second polyisocyanate component (b1) comprises a derivative of a linear aliphatic polyisocyanate.

[0013] The present invention [5] includes the water-dispersible polyisocyanate composition described in [4] above, wherein the second polyisocyanate component (b1) contains an isocyanurate derivative of a linear aliphatic polyisocyanate, the isocyanurate derivative contains one isocyanurate nucleus, and the content of the one isocyanurate nucleus is 50% by mass or more of the total amount of the isocyanurate derivative.

[0014] The present invention [6] includes a water-dispersible polyisocyanate composition according to any one of the above [1] to [5], wherein the total amount of isocyanate groups contained in the water-dispersible polyisocyanate (A) and the isocyanate groups contained in the non-water-dispersible polyisocyanate (B) is 15 moles or more and 100 moles or less per mole of the hydrophilic group contained in the water-dispersible polyisocyanate (A).

[0015] The present invention [7] includes a curing agent comprising a water-dispersible polyisocyanate composition as described in any one of the above [1] to [6].

[0016] The present invention [8] includes an aqueous polyurethane resin composition comprising an aqueous dispersible polyisocyanate composition according to any one of the above [1] to [6] and an active hydrogen group-containing compound.

[0017] The present invention [9] includes a two-component curable polyurethane resin composition comprising the curing agent described in [7] above and a main component containing an active hydrogen group-containing compound.

[0018] The present invention

[10] includes an article comprising a workpiece and a polyurethane layer disposed on the surface of the workpiece, wherein the polyurethane layer contains a cured product of the aqueous polyurethane resin composition described in [8] above. [Effects of the Invention]

[0019] The water-dispersible polyisocyanate composition of the present invention comprises a water-dispersible polyisocyanate (A) and a non-water-dispersible polyisocyanate (B). The water-dispersible polyisocyanate (A) comprises a reaction product of a first polyisocyanate component (a1) and a hydrophilic active hydrogen component (a2) containing a hydrophilic group. The non-water-dispersible polyisocyanate (B) comprises a second polyisocyanate component (b1). The hydrophilic group comprises an anionic group and / or a nonionic group. The content of the water-dispersible polyisocyanate (A) is 10% by mass or more of the total amount of the water-dispersible polyisocyanate (A) and the non-water-dispersible polyisocyanate (B).

[0020] Therefore, the water-dispersible polyisocyanate composition of the present invention has excellent water dispersibility. Furthermore, according to the water-dispersible polyisocyanate composition of the present invention, a polyurethane resin with excellent solvent resistance can be obtained.

[0021] The aqueous polyurethane resin composition, curing agent, and two-component curable polyurethane resin composition of the present invention contain the above-mentioned water-dispersible polyisocyanate composition. Therefore, the aqueous polyurethane resin composition, curing agent, and two-component curable polyurethane resin composition of the present invention have excellent water dispersibility. Furthermore, according to the aqueous polyurethane resin composition and two-component curable polyurethane resin composition of the present invention, a polyurethane resin with excellent solvent resistance can be obtained.

[0022] The article of the present invention has excellent solvent resistance because it contains a cured coating film of the above-mentioned aqueous polyurethane resin composition. [Modes for carrying out the invention]

[0023] The aqueous-dispersible polyisocyanate composition contains an aqueous-dispersible polyisocyanate (A) and a non-aqueous-dispersible polyisocyanate (B). The aqueous-dispersible polyisocyanate composition preferably consists of an aqueous-dispersible polyisocyanate (A) and a non-aqueous-dispersible polyisocyanate (B).

[0024] The aqueous-dispersible polyisocyanate (A) is a compound having a hydrophilic group and an isocyanate group. More specifically, the aqueous-dispersible polyisocyanate (A) has one or more hydrophilic groups and two or more isocyanate groups in one molecule. Thereby, the aqueous-dispersible polyisocyanate (A) is capable of being dispersed in water.

[0025] The aqueous-dispersible polyisocyanate (A) contains a reaction product of a first polyisocyanate component (a1) and a hydrophilic active hydrogen component (a2).

[0026] Examples of the first polyisocyanate component (a1) include polyisocyanate monomers and polyisocyanate derivatives.

[0027] Examples of the polyisocyanate monomer include aliphatic polyisocyanates, aromatic polyisocyanates, and araliphatic polyisocyanates.

[0028] Examples of the aliphatic polyisocyanate include linear aliphatic polyisocyanates and alicyclic polyisocyanates.

[0029] Examples of linear aliphatic polyisocyanates include linear aliphatic diisocyanates. Examples of linear aliphatic diisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), 1,2-propane diisocyanate, 1,2-butane diisocyanate, 2,3-butane diisocyanate, 1,3-butane diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,6-diisocyanate methyl caproate. These can be used individually or in combination of two or more.

[0030] Examples of alicyclic polyisocyanates include alicyclic diisocyanates. Examples of alicyclic diisocyanates include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), and methylenebis(cyclohexyl isocyanate) (H 12 Examples include MDI and bis(isocyanatomethyl)cyclohexane (H6XDI). These can be used alone or in combination of two or more.

[0031] Examples of aromatic polyisocyanates include aromatic diisocyanates. Examples of aromatic diisocyanates include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), toluidine diisocyanate (TODI), paraphenylenedi diisocyanate, and naphthalene diisocyanate (NDI). These can be used individually or in combination of two or more types.

[0032] Examples of aromatic aliphatic polyisocyanates include aromatic aliphatic diisocyanates. Examples of aromatic aliphatic diisocyanates include xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI). These can be used individually or in combination of two or more types.

[0033] Polyisocyanate derivatives are, for example, modified products obtained by modifying the above-mentioned polyisocyanate monomer by known methods. Examples of polyisocyanate derivatives include polymers, isocyanurate derivatives, allophanate derivatives, biuret derivatives, uretdione derivatives, polyol adducts, urea derivatives, oxadiazinetrione derivatives, and carbodiimide derivatives. Polyisocyanate derivatives can be used alone or in combination of two or more types.

[0034] Preferred polyisocyanate derivatives include isocyanurate derivatives and allophanate derivatives.

[0035] As described later, isocyanurate derivatives are derivatives containing an isocyanurate group (isocyanurate ring). Furthermore, isocyanurate derivatives may optionally contain an allophanate group. That is, a polyisocyanate derivative may be an isocyanurate derivative composition containing both the isocyanurate derivative and the allophanate derivative. In an isocyanurate derivative composition, the content of the allophanate group is, for example, less than 50% by mass, preferably less than 45% by mass, and more preferably less than 40% by mass, relative to the total amount of isocyanurate and allophanate groups (the same applies hereinafter).

[0036] An allophanate derivative is a derivative containing an allophanate group. Furthermore, the allophanate derivative may optionally contain an isocyanurate group. That is, a polyisocyanate derivative may be an allophanate derivative composition containing both an allophanate derivative and an isocyanurate derivative. In the allophanate derivative composition, the content of the isocyanurate group is, for example, less than 50% by mass, preferably less than 45% by mass, and more preferably less than 40% by mass, relative to the total amount of isocyanurate groups and allophanate groups (the same applies hereinafter).

[0037] The first polyisocyanate component (a1) is preferably a linear aliphatic polyisocyanate and / or its derivatives, and more preferably a derivative of a linear aliphatic polyisocyanate. Furthermore, from the viewpoint of water dispersibility, the linear aliphatic polyisocyanate is preferably pentamethylene diisocyanate (PDI) and hexamethylene diisocyanate (HDI), and more preferably hexamethylene diisocyanate (HDI). Furthermore, from the viewpoint of water dispersibility, the derivatives are preferably isocyanurate derivatives and allophanate derivatives, and more preferably isocyanurate derivatives.

[0038] In other words, as the first polyisocyanate component (a1), from the viewpoint of water dispersibility, isocyanurate derivatives of pentamethylene diisocyanate (PDI) and isocyanurate derivatives of hexamethylene diisocyanate (HDI) are preferred.

[0039] Isocyanurate derivatives contain multiple isocyanurate molecules. Examples of these multiple molecules include isocyanurate mononuclear (3 molecules), isocyanurate dinuclear (5 molecules), isocyanurate trinuclear (7 molecules), and isocyanurate tetranuclear (9 molecules). These can be used individually or in combination of two or more types.

[0040] Furthermore, an isocyanurate n-molecule (n: natural number) refers to a derivative in which n polyisocyanate monomers (n: natural number) are linked via an isocyanurate group (isocyanurate ring).

[0041] Isocyanurate derivatives can be obtained by known methods. For example, a polyisocyanate monomer is subjected to an isocyanuration reaction in the presence of a known isocyanuration catalyst. The reaction conditions are set appropriately according to the purpose and application. This yields an isocyanurate derivative.

[0042] Furthermore, if necessary, the polyisocyanate monomer may be modified with known alcohols before the isocyanuration reaction. Also, the reaction product may be modified with known alcohols after the isocyanuration reaction. In such cases, the isocyanurate derivative may include an allophanate derivative. That is, an isocyanurate derivative composition containing both an allophanate derivative and an isocyanurate derivative may be obtained.

[0043] Furthermore, if necessary, unreacted polyisocyanate monomers may be separated from the reaction product after the isocyanuration reaction. Examples of separation methods include distillation and extraction, with distillation being preferred. Examples of distillation methods include thin-film distillation. The distillation conditions are set appropriately according to the purpose and application.

[0044] In the first polyisocyanate component (a1), the isocyanurate derivative includes, for example, a mononuclear isocyanurate (3-molecule) consisting of three polyisocyanate monomers (and alcohols as needed).

[0045] In the first polyisocyanate component (a1), the content of one isocyanurate molecule can be determined as the area ratio (GPC area ratio) in the gel permeation chromatogram of the isocyanurate derivative. The GPC area ratio of one isocyanurate molecule represents the ratio of the area of ​​the peak corresponding to the one isocyanurate molecule to the total area of ​​all peaks in the gel permeation chromatogram of the isocyanurate derivative.

[0046] More specifically, the GPC area ratio of a single isocyanurate molecule is calculated by the following method: The isocyanurate derivative is measured using a gel permeation chromatograph equipped with a differential refractometer, and a chromatogram is obtained. The ratio (area ratio) of the area of ​​the peak corresponding to the single isocyanurate molecule to the total area of ​​all peaks in the chromatogram is calculated. This area ratio is the GPC area ratio of the single isocyanurate molecule.

[0047] Note that the peak corresponding to a single isocyanurate molecule differs depending on the type of isocyanurate derivative.

[0048] For example, in isocyanurate derivatives of hexamethylene diisocyanate (HDI), the peak corresponding to a single isocyanurate molecule is a peak whose peak top is in the range of polystyrene-equivalent molecular weight (number average molecular weight) between 550 and 650.

[0049] Furthermore, for example, in the isocyanurate derivative of pentamethylene diisocyanate (PDI), the peak corresponding to a single isocyanurate molecule is a peak whose peak top is in the range of polystyrene-equivalent molecular weight (number average molecular weight) of 450 or more and less than 550.

[0050] From the viewpoint of water dispersibility and solvent resistance, in the chromatogram of the isocyanurate derivative as the first polyisocyanate component (a1), the GPC area ratio (single-nuclear area ratio) of isocyanurate nuclei is, for example, 30% or more, preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, and particularly preferably 65% ​​or more. Also, in the chromatogram of the isocyanurate derivative as the first polyisocyanate component (a1), the GPC area ratio of isocyanurate nuclei is, for example, 90% or less, preferably 85% or less, more preferably 80% or less, and even more preferably 75% or less.

[0051] In other words, from the viewpoint of water dispersibility and solvent resistance, the content ratio of isocyanurate single-nucleus compounds relative to the total amount of isocyanurate derivatives as the first polyisocyanate component (a1) is, for example, 30% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and particularly preferably 65% ​​by mass or more. Also, the content ratio of isocyanurate single-nucleus compounds relative to the total amount of isocyanurate derivatives as the first polyisocyanate component (a1) is, for example, 90% by mass or less, preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less.

[0052] Furthermore, in the first polyisocyanate component (a1), the isocyanurate derivative may further include a dinuclear isocyanurate (5 molecules) consisting of 5 molecules of polyisocyanate monomer (and alcohols as needed). The isocyanurate derivative may also further include a trinuclear or more isocyanurate (7 or more molecules) consisting of 7 or more molecules of polyisocyanate monomer (and alcohols as needed). The proportions of these components are set appropriately according to the purpose and application.

[0053] The hydrophilic active hydrogen component (a2) has a hydrophilic group and an active hydrogen group. More specifically, the hydrophilic active hydrogen component (a2) has one or more hydrophilic groups and one or more active hydrogen groups in one molecule. Examples of hydrophilic groups include anionic groups and nonionic groups. In other words, the hydrophilic group includes anionic groups and / or nonionic groups.

[0054] Examples of anionic groups include carboxylic acid groups, sulfonic acid groups, and phosphate groups. Examples of nonionic groups include polyoxyethylene groups. Examples of active hydrogen groups include hydroxyl groups, amino groups, and mercapto groups. Preferably, active hydrogen groups include hydroxyl groups and amino groups.

[0055] More specifically, hydrophilic active hydrogen components (a2) include anionic group-containing active hydrogen compounds and nonionic group-containing active hydrogen compounds.

[0056] Examples of anionic group-containing active hydrogen compounds include carboxylic acid group-containing active hydrogen compounds, sulfonic acid group-containing active hydrogen compounds, and phosphate group-containing active hydrogen compounds.

[0057] A carboxylic acid group-containing active hydrogen compound is a compound containing one or more carboxylic acid groups and one or more active hydrogen groups. Examples of carboxylic acid group-containing active hydrogen compounds include carboxylic acid group-containing monofunctional active hydrogen compounds and carboxylic acid group-containing difunctional active hydrogen compounds. A carboxylic acid group-containing monofunctional active hydrogen compound has one carboxylic acid group and one active hydrogen group. A carboxylic acid group-containing difunctional active hydrogen compound has one carboxylic acid group and two active hydrogen groups. Preferably, a carboxylic acid group-containing difunctional active hydrogen compound is mentioned.

[0058] Examples of carboxylic acid group-containing bifunctional active hydrogen compounds include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, dimethylolheptanoic acid, dimethylolnonanoic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid. These can be used individually or in combination of two or more. Preferably, 2,2-dimethylolpropionic acid is used.

[0059] A sulfonic acid group-containing active hydrogen compound is a compound containing one or more sulfonic acid groups and one or more active hydrogen groups. Examples of sulfonic acid group-containing active hydrogen compounds include sulfonic acid group-containing monofunctional active hydrogen compounds and sulfonic acid group-containing difunctional active hydrogen compounds. A sulfonic acid group-containing monofunctional active hydrogen compound has one sulfonic acid group and one active hydrogen group. A sulfonic acid group-containing difunctional active hydrogen compound has one sulfonic acid group and two active hydrogen groups. Preferably, a sulfonic acid group-containing monofunctional active hydrogen compound is mentioned.

[0060] Examples of sulfonic acid group-containing monofunctional active hydrogen compounds include hydroxyalkanesulfonic acid and aminosulfonic acid. Examples of hydroxyalkanesulfonic acid include hydroxymethanesulfonic acid, hydroxyethanesulfonic acid, and 3-hydroxypropanesulfonic acid. Examples of aminosulfonic acid include 2-(cyclohexylamino)-ethanesulfonic acid (CHES) and 3-(cyclohexylamino)-propanesulfonic acid (CAPS). These can be used individually or in combination of two or more. Preferably, aminosulfonic acid is used, and more preferably, 3-(cyclohexylamino)-propanesulfonic acid is used.

[0061] A phosphate-containing active hydrogen compound is a compound containing one or more phosphate groups and one or more active hydrogen groups. Examples of phosphate-containing active hydrogen compounds include phosphate-containing monofunctional active hydrogen compounds and phosphate-containing difunctional active hydrogen compounds. A phosphate-containing monofunctional active hydrogen compound has one phosphate group and one active hydrogen group. A phosphate-containing difunctional active hydrogen compound has one phosphate group and two active hydrogen groups. Preferably, a phosphate-containing monofunctional active hydrogen compound is mentioned.

[0062] Examples of phosphate-containing monofunctional active hydrogen compounds include hydroxyalkylphosphonic acids and aminoalkylphosphonic acids.

[0063] Anionic group-containing active hydrogen compounds can be used alone or in combination of two or more types. Preferably, anionic group-containing active hydrogen compounds include carboxylic acid group-containing active hydrogen compounds and sulfonic acid group-containing active hydrogen compounds, and more preferably sulfonic acid group-containing active hydrogen compounds.

[0064] Examples of nonionic group-containing active hydrogen compounds include polyoxyethylene compounds. Examples of polyoxyethylene compounds include compounds having both an active hydrogen group and at least three consecutive ethylene oxide groups. Examples of such polyoxyethylene compounds include single-ended polyoxyethylene glycols and polyoxyethylene side-chain-containing diols.

[0065] Examples of end-closed polyoxyethylene glycols include alkoxy polyethylene glycols in which one end is sealed with an alkyl group having 1 to 20 carbon atoms. More specifically, examples include methoxypolyoxyethylene glycol and ethoxypolyoxyethylene glycol. End-closed polyoxyethylene glycols can be produced by known methods.

[0066] Examples of polyoxyethylene side-chain-containing diols include reaction products of polyoxyethylene group-containing monoisocyanates and dialkanolamines. Polyoxyethylene side-chain-containing diols can be produced by known methods.

[0067] The number-average molecular weight of the polyoxyethylene compound is, for example, 200 or more, preferably 300 or more. Alternatively, the number-average molecular weight of the polyoxyethylene compound is, for example, 2000 or less, preferably 1000 or less.

[0068] Nonionic group-containing active hydrogen compounds can be used alone or in combination of two or more. Preferred nonionic group-containing active hydrogen compounds include polyoxyethylene compounds, and more preferably, end-closed polyoxyethylene glycols.

[0069] The hydrophilic active hydrogen component (a2) can be used alone or in combination of two or more types.

[0070] When the hydrophilic active hydrogen component (a2) is used alone, the hydrophilic active hydrogen component (a2) is preferably an anionic group-containing active hydrogen compound, more preferably a sulfonic acid group-containing active hydrogen compound, and even more preferably an aminosulfonic acid.

[0071] When two or more hydrophilic active hydrogen components (a2) are used in combination, a combination of an anionic group-containing active hydrogen compound and a nonionic group-containing active hydrogen compound is preferred as the hydrophilic active hydrogen component (a2).

[0072] Preferably, two or more hydrophilic active hydrogen components (a2) are used in combination. More preferably, the hydrophilic active hydrogen component (a2) is a combination of a sulfonic acid group-containing active hydrogen compound and a polyoxyethylene compound, and even more preferably, an aminosulfonic acid and a single-ended polyoxyethylene glycol.

[0073] When anionic-containing active hydrogen compounds and nonionic-containing active hydrogen compounds are used in combination, the ratio of these compounds used together should be appropriately determined according to the purpose and application.

[0074] For example, the amount of anionic group-containing active hydrogen compounds is, for example, 1% by mass or more, preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more, relative to the total amount of anionic group-containing active hydrogen compounds and nonionic group-containing active hydrogen compounds. Also, the amount of anionic group-containing active hydrogen compounds is, for example, 90% by mass or less, preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 10% by mass or less.

[0075] Furthermore, the nonionic group-containing active hydrogen compound is present in an amount of, for example, 10% by mass or more, preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, relative to the total amount of anionic group-containing active hydrogen compounds and nonionic group-containing active hydrogen compounds. Also, the nonionic group-containing active hydrogen compound is present in an amount of, for example, 99% by mass or less, preferably 97% by mass or less, more preferably 95% by mass or less, and even more preferably 93% by mass or less.

[0076] Furthermore, with respect to 100 parts by mass of the anionic group-containing active hydrogen compound, the nonionic group-containing active hydrogen compound is, for example, 100 parts by mass or more, preferably 500 parts by mass or more, more preferably 700 parts by mass or more, and even more preferably 900 parts by mass or more. Also, the nonionic group-containing active hydrogen compound is, for example, 2000 parts by mass or less, preferably 1500 parts by mass or less, more preferably 1300 parts by mass or less, and even more preferably 1200 parts by mass or less.

[0077] The water-dispersible polyisocyanate (A) is produced, for example, by the reaction of the above-mentioned first polyisocyanate component (a1) with a hydrophilic active hydrogen component (a2).

[0078] More specifically, the first polyisocyanate component (a1) and the hydrophilic active hydrogen component (a2) are reacted in such a proportion that free isocyanate groups remain. The method of reacting the first polyisocyanate component (a1) and the hydrophilic active hydrogen component (a2) is not particularly limited. For example, the first polyisocyanate component (a1) and the hydrophilic active hydrogen component (a2) are mixed in a predetermined proportion and heated as necessary.

[0079] The reaction ratio between the first polyisocyanate component (a1) and the hydrophilic active hydrogen component (a2) is adjusted so that free isocyanate groups remain in the reaction product.

[0080] More specifically, the equivalent ratio (active hydrogen groups / NCO) of the active hydrogen groups of the hydrophilic active hydrogen component (a2) to the isocyanate groups of the first polyisocyanate component (a1) is, for example, 0.30 or less, preferably 0.20 or less. Also, the equivalent ratio (active hydrogen groups / NCO) of the active hydrogen groups of the hydrophilic active hydrogen component (a2) to the isocyanate groups of the first polyisocyanate component (a1) is, for example, 0.01 or more, preferably 0.10 or more.

[0081] The blending ratio of the hydrophilic active hydrogen component (a2) is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, and more preferably 25 parts by mass or more, per 100 parts by mass of the first polyisocyanate component (a1). Alternatively, the blending ratio of the hydrophilic active hydrogen component (a2) is, for example, 70 parts by mass or less, preferably 60 parts by mass or less, and more preferably 55 parts by mass or less, per 100 parts by mass of the first polyisocyanate component (a1).

[0082] The reaction conditions between the first polyisocyanate component (a1) and the hydrophilic active hydrogen component (a2) are set appropriately within a range that does not impede the excellent effects of the present invention. More specifically, the environmental conditions are an inert atmosphere and atmospheric pressure. The reaction temperature is, for example, 50°C or higher, preferably 70°C or higher. The reaction temperature is, for example, 150°C or lower, preferably 110°C or lower. The reaction time is, for example, 0.5 hours or more, preferably 1 hour or more. The reaction time is, for example, 120 hours or less, preferably 72 hours or less.

[0083] The completion of the reaction is confirmed, for example, when the amount of isocyanate in the reaction solution stops changing. The amount of isocyanate is measured by titration or infrared absorption spectroscopy.

[0084] Furthermore, when an anionic group-containing active hydrogen compound is used as the hydrophilic active hydrogen component (a2), a neutralizing agent is preferably added to the reaction solution to form a salt of the anionic group. That is, the anionic group does not have to be a salt, but it may be a salt. Preferably, the anionic group is a salt of the anionic group.

[0085] Commonly used bases can be used as neutralizing agents. Specifically, organic and inorganic bases can be used. Examples of organic bases include tertiary and secondary amines. Examples of tertiary amines include trialkylamines and alkanolamines. Examples of trialkylamines include trimethylamine, triethylamine, and N,N-dimethylcyclohexylamine. Examples of alkanolamines include dimethylethanolamine, methyldiethanolamine, triethanolamine, and triisopropanolamine. Examples of secondary amines include heterocyclic amines. An example of a heterocyclic amine is morpholine. Examples of inorganic bases include ammonia, alkali metal hydroxides, alkaline earth metal hydroxides, and alkali metal carbonates. Examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of alkaline earth metal hydroxides include magnesium hydroxide and calcium hydroxide. Examples of alkali metal carbonates include sodium carbonate and potassium carbonate. These can be used individually or in combination of two or more types.

[0086] Preferably, the neutralizing agent is an organic base, more preferably a tertiary amine, even more preferably a trialkylamine, and most preferably N,N-dimethylcyclohexylamine (DMCHA).

[0087] The amount of neutralizing agent added is, for example, 0.4 equivalents or more, preferably 0.6 equivalents or more, per equivalent of anionic group. Alternatively, the amount of neutralizing agent added is, for example, 1.2 equivalents or less, preferably 1.0 equivalent or less, per equivalent of anionic group.

[0088] This yields a water-dispersible polyisocyanate (A).

[0089] The isocyanate group content of the water-dispersible polyisocyanate (A) is, for example, 15% by mass or more, preferably 20% by mass or more. Alternatively, the isocyanate group content of the water-dispersible polyisocyanate (A) is, for example, 35% by mass or less, preferably 30% by mass or less. The isocyanate group content is measured in accordance with JIS K-1556 (2006).

[0090] The water-dispersible polyisocyanate (A) may contain additives. Examples of additives include antioxidants, co-catalysts, heat stabilizers, light stabilizers, mold release agents, plasticizers, anti-blocking agents, pigments, dyes, lubricants, fillers, and hydrolysis inhibitors. These can be used individually or in combination of two or more. The proportion and timing of additive addition are determined as appropriate depending on the purpose and application.

[0091] Non-aqueous dispersible polyisocyanates (B) are compounds that lack hydrophilic groups and possess isocyanate groups. More specifically, non-aqueous dispersible polyisocyanates (B) have two or more isocyanate groups in a single molecule. Furthermore, non-aqueous dispersible polyisocyanates (B) do not have hydrophilic groups in a single molecule. As a result, non-aqueous dispersible polyisocyanates (B) are considered indispersible in water.

[0092] The non-aqueous dispersion polyisocyanate (B) contains a second polyisocyanate component (b1).

[0093] Examples of the second polyisocyanate component (b1) include the polyisocyanate monomers and polyisocyanate derivatives described above. Examples of polyisocyanate monomers include aliphatic polyisocyanates, aromatic polyisocyanates, and aromatic aliphatic polyisocyanates. Examples of polyisocyanate derivatives include polymers, isocyanurate derivatives, allophanate derivatives, biuret derivatives, uretdione derivatives, polyol adducts, urea derivatives, oxadiazinetrione derivatives, and carbodiimide derivatives. These can be used individually or in combination of two or more.

[0094] The second polyisocyanate component (b1) is preferably a linear aliphatic polyisocyanate and / or its derivatives, and more preferably a derivative of a linear aliphatic polyisocyanate. From the viewpoint of solvent resistance, the linear aliphatic polyisocyanate is preferably pentamethylene diisocyanate (PDI) and hexamethylene diisocyanate (HDI), and more preferably pentamethylene diisocyanate (PDI). From the viewpoint of water dispersibility, the derivative is preferably an isocyanurate derivative and an allophanate derivative, and more preferably an isocyanurate derivative.

[0095] In other words, as the second polyisocyanate component (b1), from the viewpoint of solvent resistance, isocyanurate derivatives of the above-mentioned linear aliphatic polyisocyanates are preferred, and more preferably are isocyanurate derivatives of pentamethylene diisocyanate (PDI) and isocyanurate derivatives of hexamethylene diisocyanate (HDI).

[0096] In the second polyisocyanate component (b1), the isocyanurate derivative contains multiple isocyanurate molecules, similar to the isocyanurate derivative in the first polyisocyanate component (a1), and preferably contains one isocyanurate molecule (three molecules).

[0097] The content of a single isocyanurate molecule can be determined as the area ratio (GPC area ratio) in the gel permeation chromatogram of the isocyanurate derivative, as described above. The GPC area ratio of a single isocyanurate molecule represents the proportion of the area of ​​the peak corresponding to the single isocyanurate molecule relative to the total area of ​​all peaks in the gel permeation chromatogram of the isocyanurate derivative.

[0098] From the viewpoint of water dispersibility and solvent resistance, in the chromatogram of the isocyanurate derivative as the second polyisocyanate component (b1), the GPC area ratio (single-nuclear area ratio) of isocyanurate nuclei is, for example, 30% or more, preferably 40% or more, more preferably 50% or more, even more preferably 60% or more, and particularly preferably 65% ​​or more. Also, in the chromatogram of the isocyanurate derivative as the second polyisocyanate component (b1), the GPC area ratio of isocyanurate nuclei is, for example, 90% or less, preferably 85% or less, more preferably 80% or less, and even more preferably 75% or less.

[0099] In other words, from the viewpoint of water dispersibility and solvent resistance, the content ratio of isocyanurate single-nucleus compounds to the total amount of isocyanurate derivatives as the second polyisocyanate component (b1) is, for example, 30% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and particularly preferably 65% ​​by mass or more. Also, the content ratio of isocyanurate single-nucleus compounds to the total amount of isocyanurate derivatives as the second polyisocyanate component (b1) is, for example, 90% by mass or less, preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less.

[0100] Furthermore, in the second polyisocyanate component (b1), the isocyanurate derivative may further include a dinuclear isocyanurate (5 molecules) consisting of 5 molecules of polyisocyanate monomer (and alcohols as needed). The isocyanurate derivative may also further include a trinuclear or more isocyanurate (7 or more molecules) consisting of 7 or more molecules of polyisocyanate monomer (and alcohols as needed). The proportions of these components are set appropriately according to the purpose and application.

[0101] The non-aqueous dispersed polyisocyanate (B) does not contain the reaction product of the second polyisocyanate component (b1) and the hydrophilic active hydrogen component (a2) described above. More specifically, the non-aqueous dispersed polyisocyanate (B) preferably consists of the second polyisocyanate component (b1).

[0102] The isocyanate group content of the non-aqueous dispersed polyisocyanate (B) is, for example, 15% by mass or more, preferably 20% by mass or more. Alternatively, the isocyanate group content of the non-aqueous dispersed polyisocyanate (B) is, for example, 35% by mass or less, preferably 30% by mass or less. The isocyanate group content is measured in accordance with JIS K-1556 (2006).

[0103] Non-aqueous dispersion polyisocyanate (B) may contain additives. Examples of additives include antioxidants, co-catalysts, heat stabilizers, light stabilizers, mold release agents, plasticizers, anti-blocking agents, pigments, dyes, lubricants, fillers, and hydrolysis inhibitors. These can be used individually or in combination of two or more. The proportion and timing of additive addition are determined appropriately according to the purpose and application.

[0104] A water-dispersible polyisocyanate composition can be obtained, for example, by mixing a separately prepared water-dispersible polyisocyanate (A) with a non-water-dispersible polyisocyanate (B).

[0105] The content of water-dispersible polyisocyanate (A) relative to the total amount of water-dispersible polyisocyanate (A) and non-water-dispersible polyisocyanate (B) is 10% by mass or more, preferably 12% by mass or more, and more preferably 15% by mass or more. Furthermore, the content of water-dispersible polyisocyanate (A) relative to the total amount of water-dispersible polyisocyanate (A) and non-water-dispersible polyisocyanate (B) is, for example, 50% by mass or less, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less.

[0106] Furthermore, the content of non-aqueous dispersed polyisocyanate (B) relative to the total amount of water-dispersible polyisocyanate (A) and non-aqueous dispersed polyisocyanate (B) is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more. Also, the content of non-aqueous dispersed polyisocyanate (B) relative to the total amount of water-dispersible polyisocyanate (A) and non-aqueous dispersed polyisocyanate (B) is 90% by mass or less, preferably 88% by mass or less, and more preferably 85% by mass or less.

[0107] Furthermore, the blending ratio of water-dispersible polyisocyanate (A) and non-water-dispersible polyisocyanate (B) can be adjusted according to the ratio of isocyanate groups (total amount) to hydrophilic groups.

[0108] From the viewpoint of water dispersibility and solvent resistance, the blending ratio of water-dispersible polyisocyanate (A) and non-water-dispersible polyisocyanate (B) is preferably adjusted. This adjusts the ratio of the total amount of isocyanate groups contained in water-dispersible polyisocyanate (A) and isocyanate groups contained in non-water-dispersible polyisocyanate (B) (hereinafter, the total amount of isocyanate groups) to the amount of hydrophilic groups contained in water-dispersible polyisocyanate (A) (hereinafter, the amount of hydrophilic groups) to a predetermined range.

[0109] More specifically, in a water-dispersible polyisocyanate composition, the total amount of isocyanate groups per mole of hydrophilic groups (isocyanate groups / moles of hydrophilic groups) is, for example, 10 moles or more, preferably 15 moles or more, more preferably 20 moles or more, even more preferably 30 moles or more, and particularly preferably 40 moles or more. Also, in a water-dispersible polyisocyanate composition, the total amount of isocyanate groups per mole of hydrophilic groups (isocyanate groups / moles of hydrophilic groups) is, for example, 150 moles or less, preferably 100 moles or less, more preferably 80 moles or less, even more preferably 60 moles or less, and particularly preferably 50 moles or less.

[0110] This yields a water-dispersible polyisocyanate composition. The water-dispersible polyisocyanate composition is a composition (mixture) containing a water-dispersible polyisocyanate (A) and a non-water-dispersible polyisocyanate (B).

[0111] Furthermore, a water-dispersible polyisocyanate composition is distinguished from, for example, a composition consisting of a water-dispersible polyisocyanate (A) in which the amount of hydrophilic groups introduced is reduced, without containing a non-water-dispersible polyisocyanate (B).

[0112] Water-dispersible polyisocyanate compositions may contain additives. Examples of additives include antioxidants, co-catalysts, heat stabilizers, light stabilizers, mold release agents, plasticizers, anti-blocking agents, pigments, dyes, lubricants, fillers, and hydrolysis inhibitors. These can be used individually or in combination of two or more. The proportion and timing of additive addition are determined appropriately according to the purpose and application.

[0113] Furthermore, the water-dispersible polyisocyanate composition may be solid. Also, the water-dispersible polyisocyanate composition may be a solution and / or dispersion. In the solution and / or dispersion of the water-dispersible polyisocyanate composition, the solid content concentration is, for example, 10% by mass or more, preferably 20% by mass or more. Alternatively, the solid content concentration may be, for example, 90% by mass or less, preferably 80% by mass or less.

[0114] Furthermore, in a water-dispersible polyisocyanate composition, the isocyanate group may be a free isocyanate group. Alternatively, the isocyanate group may be blocked by a blocking agent. That is, the isocyanate group can be a free isocyanate group or a blocked isocyanate group.

[0115] Blocking agents are compounds that have an active group (hereinafter referred to as a blocking group) that reacts with an isocyanate group and regenerate the isocyanate group by dissociation upon heat. Examples of blocking agents include active methylene compounds, active methine compounds, imidazole compounds, imidazoline compounds, pyrimidine compounds, guanidine compounds, alcohol compounds, phenolic compounds, amine compounds, imine compounds, oxime compounds, carbamic acid compounds, urea compounds, acid amide compounds, lactam compounds, acid imide compounds, triazole compounds, pyrazole compounds, mercaptan compounds, and bisulfites. These can be used alone or in combination of two or more. Preferred blocking agents include imidazole compounds, imidazoline compounds, oxime compounds, and pyrazole compounds.

[0116] Blocked isocyanate groups are formed when free isocyanate groups react with the blocking agent.

[0117] For example, the free isocyanate groups of the water-dispersible polyisocyanate (A) may have reacted with the blocking groups in the blocking agent beforehand. Also, for example, the free isocyanate groups of the non-water-dispersible polyisocyanate (B) may have reacted with the blocking groups of the blocking agent beforehand. Furthermore, after mixing the water-dispersible polyisocyanate (A) and the non-water-dispersible polyisocyanate (B), the free isocyanate groups of the water-dispersible polyisocyanate composition may have reacted with the blocking groups of the blocking agent.

[0118] The equivalent ratio of free isocyanate groups to blocking groups in the blocking agent is set appropriately according to the purpose and application. More specifically, the equivalent ratio of blocking groups to free isocyanate groups (blocking group / isocyanate group) is, for example, 0.2 or more, preferably 0.5 or more, more preferably 0.8 or more, and even more preferably 1.0 or more. Alternatively, the equivalent ratio of blocking groups to free isocyanate groups (blocking group / isocyanate group) is, for example, 1.5 or less, preferably 1.2 or less, and more preferably 1.1 or less.

[0119] The reaction conditions between the free isocyanate group and the blocked group are set appropriately within a range that does not impede the excellent effects of the present invention. More specifically, the environmental conditions are an inert atmosphere and atmospheric pressure. The reaction temperature is, for example, 0°C or higher, preferably 20°C or higher. The reaction temperature is, for example, 100°C or lower, preferably 80°C or lower, more preferably 70°C or lower. The reaction time is, for example, 0.5 hours or more, preferably 1.0 hour or more. The reaction time is, for example, 24 hours or less, preferably 12 hours or less.

[0120] Furthermore, each of the above reactions may be carried out without a solvent. Alternatively, each of the above reactions may be carried out in the presence of a solvent. Examples of solvents include well-known organic solvents. The proportion of the solvent should be set appropriately according to the purpose and application. If a solvent is used, it can also be removed after the reaction is complete. Examples of methods for removing the solvent include distillation and extraction.

[0121] In the following explanation, the isocyanate group includes both free isocyanate groups and isocyanate groups blocked by a blocking agent.

[0122] The isocyanate group content of the water-dispersible polyisocyanate composition is, for example, 15% by mass or more, preferably 20% by mass or more. Alternatively, the isocyanate group content of the water-dispersible polyisocyanate composition is, for example, 35% by mass or less, preferably 30% by mass or less. The isocyanate group content is measured in accordance with JIS K-1556 (2006).

[0123] The average number of isocyanate groups in the water-dispersible polyisocyanate composition is, for example, 2 or more, preferably 2.2 or more. Alternatively, the average number of isocyanate groups in the water-dispersible polyisocyanate composition is, for example, 4.0 or less, preferably 3.5 or less.

[0124] Furthermore, if the water-dispersible polyisocyanate composition contains anionic groups, the content of the anionic groups is, for example, 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, relative to the total amount of the water-dispersible polyisocyanate composition. Also, the content of the anionic groups is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, relative to the total amount of the water-dispersible polyisocyanate composition.

[0125] Furthermore, if the water-dispersible polyisocyanate composition contains anionic groups, the acid value of the water-dispersible polyisocyanate composition is, for example, 1 mg KOH / g or more, preferably 2 mg KOH / g or more, and more preferably 3 mg KOH / g or more. Also, the acid value of the water-dispersible polyisocyanate composition is, for example, 56 mg KOH / g or less, preferably 34 mg KOH / g or less, and more preferably 12 mg KOH / g or less.

[0126] Furthermore, if the water-dispersible polyisocyanate composition contains nonionic groups (oxyethylene units), the content of nonionic groups (oxyethylene units) is, for example, 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, relative to the total amount of the water-dispersible polyisocyanate composition. Also, the content of nonionic groups (oxyethylene units) is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less, relative to the total amount of the water-dispersible polyisocyanate composition.

[0127] The above-described water-dispersible polyisocyanate composition comprises a water-dispersible polyisocyanate (A) and a non-water-dispersible polyisocyanate (B). The water-dispersible polyisocyanate (A) comprises a reaction product of a first polyisocyanate component (a1) and a hydrophilic active hydrogen component (a2) containing a hydrophilic group. The non-water-dispersible polyisocyanate (B) comprises a second polyisocyanate component (b1). The hydrophilic group comprises an anionic group and / or a nonionic group. The content of the water-dispersible polyisocyanate (A) is 10% by mass or more of the total amount of the water-dispersible polyisocyanate (A) and the non-water-dispersible polyisocyanate (B).

[0128] Therefore, the above-mentioned water-dispersible polyisocyanate composition has excellent water dispersibility. Furthermore, the above-mentioned water-dispersible polyisocyanate composition yields a polyurethane resin with excellent solvent resistance.

[0129] Therefore, the above-mentioned water-dispersible polyisocyanate composition is preferably included in an aqueous polyurethane resin composition.

[0130] The aqueous polyurethane resin composition comprises the above-mentioned water-dispersible polyisocyanate composition and an active hydrogen group-containing compound. The aqueous polyurethane resin composition may also be a one-component curable polyurethane resin composition in which the water-dispersible polyisocyanate composition and the active hydrogen group-containing compound are mixed. Alternatively, the polyurethane resin composition may be a two-component curable polyurethane resin composition in which the water-dispersible polyisocyanate composition and the active hydrogen group-containing compound are prepared separately and blended at the time of use. Preferably, the aqueous polyurethane resin composition is a two-component curable polyurethane resin composition.

[0131] The two-component curable polyurethane resin composition contains an active hydrogen group-containing compound as its main component. Furthermore, the two-component curable polyurethane resin composition contains the above-mentioned water-dispersible polyisocyanate composition as a curing agent. In other words, the curing agent is the curing agent for the two-component curable polyurethane resin composition.

[0132] The main component includes, for example, an aqueous dispersion (emulsion) of a compound containing an active hydrogen group.

[0133] Examples of active hydrogen group-containing compounds include macropolyols. Macropolyols are relatively high molecular weight organic compounds (polymers) that have two or more hydroxyl groups in their molecule. The number-average molecular weight of macropolyols is, for example, greater than 600 and less than or equal to 20,000.

[0134] Examples of macropolyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These can be used individually or in combination of two or more types.

[0135] An aqueous dispersion of an active hydrogen group-containing compound can be prepared, for example, by adding water to the active hydrogen group-containing compound. Alternatively, an aqueous dispersion of an active hydrogen group-containing compound can also be prepared, for example, by adding the active hydrogen group-containing compound to water. Furthermore, a known external emulsifier can be added to water and / or the active hydrogen group-containing compound as needed. Alternatively, a known external emulsifier can be added to a mixture of water and the active hydrogen group-containing compound.

[0136] In an aqueous dispersion of an active hydrogen group-containing compound, the content ratio of the active hydrogen group-containing compound is appropriately set according to the purpose and application. For example, the active hydrogen group-containing compound (solid content) is, for example, 1% by mass or more, preferably 5% by mass or more, relative to the total amount of the aqueous dispersion. Alternatively, the active hydrogen group-containing compound (solid content) is, for example, 30% by mass or less, preferably 20% by mass or less, relative to the total amount of the aqueous dispersion.

[0137] The curing agent contains the above-mentioned aqueous-dispersible polyisocyanate composition. More specifically, the curing agent contains, for example, an aqueous dispersion (emulsion) of the aqueous-dispersible polyisocyanate composition.

[0138] An aqueous dispersion of a water-dispersible polyisocyanate composition can be prepared, for example, by adding water to the water-dispersible polyisocyanate composition. Alternatively, an aqueous dispersion of a water-dispersible polyisocyanate composition can also be prepared, for example, by adding the water-dispersible polyisocyanate composition to water. Furthermore, a known external emulsifier can be added to water and / or the water-dispersible polyisocyanate composition as needed. Alternatively, a known external emulsifier can be added to a mixture of water and the water-dispersible polyisocyanate composition.

[0139] In an aqueous dispersion of a water-dispersible polyisocyanate composition, the content of the water-dispersible polyisocyanate composition is appropriately set according to the purpose and application. For example, the amount of the water-dispersible polyisocyanate composition (solid content) relative to the total amount of the aqueous dispersion is, for example, 1% by mass or more, preferably 5% by mass or more. Alternatively, the amount of the water-dispersible polyisocyanate composition (solid content) relative to the total amount of the aqueous dispersion is, for example, 30% by mass or less, preferably 20% by mass or less.

[0140] Furthermore, if an aqueous dispersion of the active hydrogen group-containing compound is prepared, an aqueous dispersion of the aqueous-dispersible polyisocyanate composition does not need to be prepared. In other words, the solid content of the aqueous-dispersible polyisocyanate composition can be used as is.

[0141] Furthermore, when an aqueous dispersion of a water-dispersible polyisocyanate composition is prepared, an aqueous dispersion of the active hydrogen group-containing compound does not need to be prepared. In other words, the solid component of the active hydrogen group-containing compound can be used as is.

[0142] Furthermore, aqueous polyurethane resin compositions may contain additives. Examples of additives include catalysts, solvents, epoxy resins, coating properties improvers, leveling agents, defoamers, antioxidants, UV absorbers, thickeners, anti-settling agents, plasticizers, surfactants, pigments, antifungal agents, fillers, organic particles, and inorganic particles. Additives may be incorporated into the main component. Alternatively, additives may be incorporated into the curing agent. The amount of additives is appropriately determined depending on the purpose and application.

[0143] When using a two-component curable polyurethane resin composition as an aqueous polyurethane resin composition, a main component and a curing agent are blended. The blending ratio of the main component and the curing agent is adjusted, for example, based on the equivalent ratio of isocyanate groups (isocyanate groups / hydroxyl groups) of the water-dispersible polyisocyanate to the active hydrogen groups of the active hydrogen group-containing compound.

[0144] More specifically, the equivalent ratio of isocyanate groups of the water-dispersible polyisocyanate to the active hydrogen groups of the active hydrogen group-containing compound (isocyanate groups / active hydrogen groups) is, for example, 0.1 or more, preferably 0.5 or more. Furthermore, the equivalent ratio of isocyanate groups of the water-dispersible polyisocyanate to the active hydrogen groups of the active hydrogen group-containing compound (isocyanate groups / active hydrogen groups) is, for example, 5 or less, preferably 3 or less.

[0145] The mixture of the main agent and the curing agent (aqueous polyurethane resin composition) is then applied to any substrate using a known application method and dried under any drying conditions. Examples of application methods include spray coating, dip coating, spin coating, rotary atomization coating, and curtain coating.

[0146] This forms a coating film of the aqueous polyurethane resin composition. The coating film is then cured by heating. The heating conditions are set appropriately depending on the main agent and the curing agent. For example, if the isocyanate group of the curing agent is not blocked by a blocking agent, the heating temperature is, for example, 60°C or higher, preferably 80°C or higher. Alternatively, the heating temperature is, for example, 150°C or lower, preferably 130°C or lower. The heating time is, for example, 1 minute or more, preferably 5 minutes or more. The heating time is, for example, 24 hours or less, preferably 12 hours or less.

[0147] This yields a polyurethane resin as a cured product made from an aqueous polyurethane resin composition. This also yields an article containing a workpiece and a polyurethane layer. More specifically, the article comprises a workpiece and a polyurethane layer disposed on the surface of the workpiece, the polyurethane layer containing a cured coating film of the aqueous polyurethane resin composition. The polyurethane resin is also cured under any conditions as needed.

[0148] Furthermore, when the isocyanate groups of the water-dispersible polyisocyanate composition are blocked by a blocking agent, the aqueous polyurethane resin composition is preferably a one-component curable polyurethane resin composition. In such cases, the mixing ratio of the water-dispersible polyisocyanate and the active hydrogen group-containing compound is the same as the mixing ratio of the water-dispersible polyisocyanate and the active hydrogen group-containing compound in the above-mentioned two-component curable polyurethane resin composition.

[0149] Furthermore, the above-mentioned aqueous polyurethane resin composition, curing agent, and two-component curable polyurethane resin composition contain the above-mentioned water-dispersible polyisocyanate composition. Therefore, the above-mentioned aqueous polyurethane resin composition, curing agent, and two-component curable polyurethane resin composition have excellent water dispersibility. In addition, the above-mentioned aqueous polyurethane resin composition, curing agent, and two-component curable polyurethane resin composition yield a polyurethane resin with excellent solvent resistance.

[0150] Furthermore, since the above-mentioned article contains a cured coating film of the above-mentioned aqueous polyurethane resin composition, it has excellent solvent resistance.

[0151] Therefore, the above-mentioned water-dispersible polyisocyanate composition, aqueous polyurethane resin composition, and articles are suitably used, for example, in automobile exteriors, surface resin coatings for household electrical appliances, and flexographic inks for flexible packaging. [Examples]

[0152] The present invention will be further described with reference to the following examples, but the present invention is not limited thereto. Specific numerical values ​​such as blending ratios (content), physical properties, and parameters used in the following description may be replaced with the corresponding upper limits (numerical values ​​defined as "less than or equal to" or "less than") or lower limits (numerical values ​​defined as "greater than or equal to" or "greater than or equal to" or "greater than or equal to") of the blending ratios (content), physical properties, and parameters described in the "Modes for Carrying Out the Invention" above. Note that "parts" and "%" refer to mass unless otherwise specified.

[0153] 1.GPC measurement method The samples were measured using gel permeation chromatography (GPC), and the area ratio of each peak's area to the total peak's area in the resulting chromatogram (chart) was determined.

[0154] Furthermore, if the sample was an HDI derivative, the area percentage of peaks with peak tops in the range of polystyrene-equivalent molecular weight 550 or more and less than 650 was defined as the content ratio (mass%) of one isocyanurate molecule (3 molecules) in the HDI derivative.

[0155] Furthermore, if the sample was a PDI derivative, the area percentage of peaks with peak tops in the range of polystyrene-equivalent molecular weight 450 or more and less than 550 was defined as the content ratio (mass%) of one isocyanurate molecule (three molecules) in the PDI derivative.

[0156] For GPC measurement, approximately 0.03 g of the sample was taken, methyl urethane was added with methanol, excess methanol was removed, and 10 mL of tetrahydrofuran was added to dissolve it. The resulting solution was then GPC measured under the following conditions.

[0157] Analytical instrument: High-speed GPC instrument HLC-8320 (manufactured by Tosoh) Detector: Differential refractive detector Eluent: Tetrahydrofuran Isolation column: Connect (1) to (4) below in series. (1) TSKgel Guardcolum HXL-L 6.0×40 (manufactured by Tosoh Corporation) (2) TSKgel G1000HXL 7.8×300 (manufactured by Tosoh Corporation) (3) TSKgel G2000HXL 7.8×300 (manufactured by Tosoh Corporation) (4) TSKgel G3000HXL 7.8×300 (manufactured by Tosoh Corporation) Measurement temperature: 40℃ Flow rate: 1mL / min Sample injection volume: 100 μL Analysis device: Eco SEC (manufactured by Tosoh Corporation) System correction Standard material name: Polystyrene Calibration curve creation method: Using TSKstandard Polystyrene manufactured by TOSOH with different molecular weights, a graph of retention time and molecular weight was created.

[0158] 2. Isocyanate group content and isocyanurate conversion rate The isocyanate group content was measured using a potentiometric titrator and the n-dibutylamine method in accordance with JIS K-1556 (2006).

[0159] Furthermore, the conversion rate of isocyanate groups to isocyanurate was calculated using the following formula.

[0160] Isocyanurate conversion rate = 100 - (Isocyanate group content after isocyanuration reaction / Isocyanate group content after urethane reaction and before isocyanuration reaction × 100) 3. Isocyanurate derivatives Synthesis Example 1 In a four-necked flask equipped with a stirrer, thermometer, reflux tubing, and nitrogen inlet tube, 1000.0 g of 1,6-hexamethylene diisocyanate (HDI) and 1.5 g of isobutanol were charged, and the urethane reaction was carried out at 80°C for 2 hours. The equivalent ratio (NCO / OH) of the isocyanate groups of 1,6-hexamethylene diisocyanate to the hydroxyl groups of isobutanol was 600.

[0161] Next, 0.52 g of DABCO-TMR (N-(2-hydroxypropyl)-N,N,N-trimethylammonium-2-ethylhexanoate, manufactured by Air Products) was added to the reaction product as an isocyanurate catalyst, and the reaction was carried out at 80-86°C for 2 hours. Then, by titration, it was confirmed that 10% by mass of the isocyanate groups remaining in the reaction product after the urethane formation had been converted to isocyanurate groups. At this time, 0.60 g of orthotoluenesulfonic acid was added to the flask to stop the reaction.

[0162] Subsequently, the reaction product was distilled using a thin-film distillation apparatus (vacuum 0.05 kPa, temperature 140°C) to remove unreacted 1,6-hexamethylene diisocyanate. This yielded the isocyanurate derivative of HDI (HDI derivative H-1).

[0163] The isocyanate group content of HDI derivative H-1 was 22.7% by mass. Furthermore, the content of isocyanurate single-nucleus (3-molecular-weight) compounds in HDI derivative H-1 was 70% by mass.

[0164] Synthesis example 2 (HDI derivative H-2) 1000.0 g of 1,6-hexamethylene diisocyanate (HDI) and 26.8 g of 1,3-butanediol were used. Except for these, the procedure was the same as in Synthesis Example 1 to obtain the isocyanurate derivative of HDI (HDI derivative H-2). The equivalent ratio (NCO / OH) of the isocyanate groups of 1,6-hexamethylene diisocyanate to the hydroxyl groups of 1,3-butanediol was 20.

[0165] The isocyanate group content of HDI derivative H-2 was 21.0% by mass. Furthermore, the content of isocyanurate single-nuclear (3-molecule) compounds in HDI derivative H-2 was 40% by mass.

[0166] Synthesis example 3 (PDI derivative P-3) 1,000 g of 1,5-pentamethylene diisocyanate (PDI) and 1.6 g of isobutanol were used. Except for these, the procedure was the same as in Synthesis Example 1 to obtain an isocyanurate derivative of PDI (PDI derivative P-3). The equivalent ratio (NCO / OH) of the isocyanate groups of 1,5-pentamethylene diisocyanate to the hydroxyl groups of isobutanol was 600.

[0167] The isocyanate group content of PDI derivative P-3 was 24.7% by mass. Furthermore, the content of isocyanurate mononuclear molecules (3 molecules) in PDI derivative P-3 was 70% by mass.

[0168] 4. Water-dispersible polyisocyanate (A) Manufacturing Examples 1-7 The formulations described in Table 1 involved mixing the first polyisocyanate (a1) with a hydrophilic active hydrogen component (a2). These mixtures were then reacted under dry nitrogen at 80-90°C for 8 hours. The hydrophilic active hydrogen component (a2) consisted of one or both of the following:

[0169] 3-(Cyclohexylamino)-propanesulfonic acid (CAPS, sulfonic acid group-containing active hydrogen compound) Methoxypolyoxyethylene glycol (MePEG, end-closed polyoxyethylene glycol) with a number-average molecular weight of 400 Furthermore, when CAPS was used, the reaction product was formulated as described in Table 1, and N,N-dimethylcyclohexylamine (DMCHA) was added as a neutralizing agent.

[0170] This yielded a water-dispersible polyisocyanate (A). The isocyanate group content of the water-dispersible polyisocyanate (A) is shown in Table 1.

[0171] 5. Non-aqueous dispersion polyisocyanate (B) Preparation Examples 1-3 As shown in Table 2, HDI derivatives H-1 to H-2, or PDI derivative P-3, were prepared directly as non-aqueous dispersed polyisocyanates (B). The isocyanate group content and the single-nuclear (3-molecule) content of non-aqueous dispersed polyisocyanates (B) are shown in Table 2.

[0172] 6. Polyisocyanate compositions Example 1 The combinations shown in Tables 3 and 4, consisting of a water-dispersible polyisocyanate (A) and a non-water-dispersible polyisocyanate (B), were mixed under dry nitrogen at 60°C. This yielded polyisocyanate compositions. In Comparative Examples 2 to 4, water-dispersible polyisocyanate (A) was used alone.

[0173] The isocyanate group content of the polyisocyanate composition is shown in Tables 3 and 4.

[0174] Furthermore, the ratio of the total amount of isocyanate groups in the water-dispersible polyisocyanate (A) to the total amount of isocyanate groups in the non-water-dispersible polyisocyanate (B) (isocyanate groups / moles of hydrophilic groups) was calculated to equal 1 mole of hydrophilic groups in the water-dispersible polyisocyanate (A). The results are shown in Tables 3 and 4.

[0175] 7. Evaluation (1) Water dispersibility 2.5 g of polyisocyanate composition was slowly added dropwise to 47.5 g of deionized water while stirring with a magnetic stirrer (500 rpm), and the mixture was stirred for 5 minutes. The resulting aqueous dispersion of the polyisocyanate composition was then filtered through a 100-mesh filter. The aqueous dispersibility of the polyisocyanate composition was then evaluated according to the following criteria.

[0176] ○: No sediment was observed after stirring was stopped.

[0177] △: After stirring was stopped, sediment was observed.

[0178] ×: The polyisocyanate did not disperse in water. (2) Solvent resistance An aqueous acrylic emulsion (solid content concentration 40.0% by mass, hydroxyl value 100 mg KOH / g) was used as the main component, and a polyisocyanate composition was used as the curing agent. The equivalent ratio of isocyanate groups in the curing agent to hydroxyl groups in the main component (NCO / OH) was set to 1.0. The mixture of the main component and curing agent was then stirred for 15 minutes.

[0179] Next, the mixture was applied to a cold-rolled steel sheet (SPCC, JIS G 3141 (2017)) to obtain a coating film (undried coating film). The amount applied was adjusted so that the dry thickness of the coating film was 20 μm.

[0180] Next, the coating film (undried coating film) was dried at 80°C for 30 minutes. After that, the dried coating film was aged at 23°C for 7 days. This resulted in a cured coating film.

[0181] Subsequently, the solvent resistance of the cured coating was evaluated using a rubbing tester (Imoto Seisakusho, model IMC-1507). Specifically, the surface of the cured coating was rubbed using cotton wool thoroughly soaked in ethanol. The load was 0.5 kgf. The number of rubbing passes (back and forth) until the coating was completely removed was then measured.

[0182] [Table 1]

[0183] [Table 2]

[0184] [Table 3]

[0185] [Table 4]

[0186] The details of the abbreviations used in the table are as follows. H-1; Isocyanurate derivative of Synthesis Example 1 H-2; Isocyanurate derivative of synthesis example 2 P-3; Isocyanurate derivative of synthesis example 3 CAPS; 3-(cyclohexylamino)-propanesulfonic acid, sulfonic acid group-containing active hydrogen compound MePEG; Methoxypolyoxyethylene glycol with a number-average molecular weight of 400, end-closed polyoxyethylene glycol DMCHA; N,N-dimethylcyclohexylamine, neutralizing agent

[0187] The above invention is provided as an illustrative embodiment of the present invention, but this is merely illustrative and should not be interpreted restrictively. Modifications of the present invention that are obvious to those skilled in the art are included in the claims described below. [Industrial applicability]

[0188] The water-dispersible polyisocyanate composition, curing agent, aqueous polyurethane resin composition, two-component curable polyurethane resin composition, and articles of the present invention are suitably used in the automotive exterior, surface resin coating, and flexible packaging flexographic ink fields.

Claims

1. This is a water-dispersible polyisocyanate composition comprising a water-dispersible polyisocyanate (A) and a non-water-dispersible polyisocyanate (B). The aforementioned aqueous-dispersible polyisocyanate (A) is The product comprises a reaction product of a first polyisocyanate component (a1) and a hydrophilic active hydrogen component (a2). The hydrophilic active hydrogen component (a2) has a hydrophilic group and an active hydrogen group, The hydrophilic group includes an anionic group and / or a nonionic group, The aforementioned non-aqueous dispersion polyisocyanate (B) is It contains a second polyisocyanate component (b1), It does not contain the reaction product of the second polyisocyanate component (b1) and the hydrophilic active hydrogen component (a2), The second polyisocyanate component (b1) contains an isocyanurate derivative of a linear aliphatic polyisocyanate, The isocyanurate derivative contains one isocyanurate molecule, The content ratio of the isocyanurate mononuclear body is 50% by mass or more and 90% by mass or less, relative to the total amount of the isocyanurate derivative. A water-dispersible polyisocyanate composition in which the content of the water-dispersible polyisocyanate (A) is 10% by mass or more and 50% by mass or less, relative to the total amount of the water-dispersible polyisocyanate (A) and the non-water-dispersible polyisocyanate (B).

2. The aqueous-dispersible polyisocyanate composition according to claim 1, wherein the content of the aqueous-dispersible polyisocyanate (A) is less than 40% by mass of the total amount of the aqueous-dispersible polyisocyanate (A) and the non-aqueous-dispersible polyisocyanate (B).

3. The aqueous dispersible polyisocyanate composition according to claim 1, wherein the first polyisocyanate component (a1) comprises a derivative of a linear aliphatic polyisocyanate.

4. The total amount of isocyanate groups contained in the aqueous-dispersible polyisocyanate (A) and the isocyanate groups contained in the non-aqueous-dispersible polyisocyanate (B) is With respect to 1 mole of the hydrophilic group contained in the aqueous-dispersible polyisocyanate (A), The aqueous dispersible polyisocyanate composition according to claim 1, wherein the amount is 15 moles or more and 100 moles or less.

5. A curing agent comprising the water-dispersible polyisocyanate composition described in claim 1.

6. The aqueous dispersible polyisocyanate composition according to claim 1, Compounds containing active hydrogen groups and A water-based polyurethane resin composition containing [a specific compound / component].

7. The curing agent according to claim 5, The main ingredient contains a compound containing an active hydrogen group. A two-component curable polyurethane resin composition containing the following:

8. The system comprises an object to be coated and a polyurethane layer disposed on the surface of the object to be coated. An article wherein the polyurethane layer comprises a cured product of the aqueous polyurethane resin composition described in claim 6.

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