Water-dispersible polyisocyanate, water-based polyurethane resin composition, and article

Abstract

A water-dispersible polyisocyanate contains isocyanate groups and sulfo groups. The water-dispersible polyisocyanate includes a reaction product of a polyisocyanate component and a hydrophilic active hydrogen component. The polyisocyanate component includes a bis(isocyanatomethyl)cyclohexane derivative. The hydrophilic active hydrogen component includes a sulfo group-containing active hydrogen compound. The bis(isocyanatomethyl)cyclohexane derivative includes a uretonimine derivative and an isocyanurate derivative. The uretonimine derivative is contained in a proportion of 25% by mass or more and 75% by mass or less relative to the total amount of the uretonimine derivative and the isocyanurate derivative.

Description

Technical Field

[0001] This invention relates to water-dispersible polyisocyanates, waterborne polyurethane resin compositions, and articles. Background Technology

[0002] Polyurethane resins are widely used in various industrial sectors. Polyurethane resins are the product of the reaction between polyisocyanate and polyol components.

[0003] Polyisocyanate components are prepared, for example, in the form of organic solvent solutions. In recent years, to improve environmental and workability, there has been a demand for the preparation of polyisocyanate components in the form of aqueous dispersions. That is, polyisocyanate components that can be dispersed in water are required.

[0004] As a polyisocyanate component that can be dispersed in water, the following component has been proposed: a mixture of polyisocyanates obtained by reacting pentamethylene-1,5-diisocyanate isocyanurate with 3-(cyclohexylamino)propanesulfonic acid (see, for example, Patent Document 1 (Example 5)).

[0005] In addition, as a polyisocyanate component that can be dispersed in water, the following component has also been proposed: a mixture of polyisocyanates obtained by reacting hexamethylene-1,6-diisocyanate isocyanurate with 3-(cyclohexylamino)propanesulfonic acid (see, for example, Patent Document 2 (Example 1)).

[0006] Furthermore, as a polyisocyanate component that can be dispersed in water, the following component has also been proposed: a mixture of polyisocyanates obtained by reacting isocyanurate of 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane with 3-(cyclohexylamino)propanesulfonic acid (see, for example, Patent Document 2 (Example 5)).

[0007] The above-mentioned polyisocyanate mixture becomes water-dispersible due to the sulfone group of 3-(cyclohexylamino)propanesulfonic acid. Furthermore, a polyurethane resin can be obtained by reacting the above-mentioned polyisocyanate mixture with a polyol component.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Publication No. 2018-513239

[0011] Patent Document 2: Japanese Patent Publication No. 2003-533566 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] However, when pentamethylene-1,5-diisocyanate and / or its derivatives are dispersed in water using sulfonyl groups, the hardness of the polyurethane resin decreases.

[0014] Furthermore, the hardness of the polyurethane resin is also reduced when hexamethylene-1,6-diisocyanate and / or its derivatives are dispersed in water using sulfonyl groups.

[0015] Furthermore, when sulfonyl groups are used to disperse 1-isocyanate-3,3,5-trimethyl-5-isocyanate-methylcyclohexane and / or its derivatives in water, the curability of the polyurethane resin is reduced.

[0016] The present invention relates to a water-dispersible polyisocyanate, a waterborne polyurethane resin composition and articles that can produce a polyurethane resin with excellent hardness and excellent curability and water dispersibility.

[0017] Methods for solving problems

[0018] The present invention [1] includes a water-dispersible polyisocyanate, which is a water-dispersible polyisocyanate containing isocyanate group and sulfonate group, wherein the water-dispersible polyisocyanate contains a reaction product of polyisocyanate component and hydrophilic active hydrogen component, wherein the aforementioned polyisocyanate component contains bis(isocyanate methyl)cyclohexane derivative, wherein the aforementioned hydrophilic active hydrogen component contains active hydrogen compound containing sulfonate group, wherein the aforementioned bis(isocyanate methyl)cyclohexane derivative contains urethane derivative and isocyanurate derivative, wherein the content of the aforementioned urethane derivative is more than 25% by mass and less than 75% by mass relative to the total amount of urethane derivative and isocyanurate derivative.

[0019] The present invention [2] includes the water-dispersible polyisocyanate described in [1] above, wherein the aforementioned bis(isocyanate methyl)cyclohexane derivative comprises the reaction product of bis(isocyanate methyl)cyclohexane monomer and alcohol, wherein the aforementioned alcohol comprises a monohydric alcohol.

[0020] The present invention [3] includes the water-dispersible polyisocyanate described in [1] or [2] above, wherein the content of the sulfonyl group is 0.2% by mass or more and 5% by mass or less relative to the total amount of the aforementioned water-dispersible polyisocyanate.

[0021] The present invention [4] includes any one of the above [1] to [3] water-dispersible polyisocyanates, wherein the aforementioned isocyanate groups of the aforementioned water-dispersible polyisocyanates are blocked by a capping agent.

[0022] The present invention [5] includes an aqueous polyurethane resin composition comprising: a water-dispersible polyisocyanate as described in any one of [1] to [4] above; and a compound containing an active hydrogen group.

[0023] The present invention [6] includes an article having a coating and a polyurethane layer disposed on the surface of the coating, the polyurethane layer comprising a cured coating film of the aqueous polyurethane resin composition of claim 5.

[0024] Invention Effects

[0025] The water-dispersible polyisocyanate of the present invention comprises a reaction product of a polyisocyanate component and a hydrophilic active hydrogen component, wherein the polyisocyanate component comprises a bis(isocyanate-methyl)cyclohexane derivative, and the hydrophilic active hydrogen component comprises an active hydrogen compound containing a sulfonate group. Furthermore, the bis(isocyanate-methyl)cyclohexane derivative comprises a urethane derivative and an isocyanurate derivative, wherein the proportion of the urethane derivative is within a specified range.

[0026] Therefore, the water-dispersible polyisocyanate of the present invention can produce a polyurethane resin with excellent hardness, and has excellent curability and water dispersibility.

[0027] Furthermore, the aqueous polyurethane resin composition of the present invention contains the above-described water-dispersible polyisocyanate. Therefore, the aqueous polyurethane resin composition of the present invention can produce a polyurethane resin with excellent hardness and excellent curability.

[0028] The articles of the present invention comprise a cured coating of the above-described aqueous polyurethane resin composition, thus having a polyurethane layer with excellent hardness. Detailed Implementation

[0029] The water-dispersible polyisocyanate of the present invention contains isocyanate groups and sulfonates. Furthermore, the water-dispersible polyisocyanate is a polyisocyanate capable of being dispersed in water.

[0030] The water-dispersible polyisocyanate of the present invention comprises a reaction product of a polyisocyanate component and a hydrophilic active hydrogen component.

[0031] The polyisocyanate component contains a bis(isocyanate methyl)cyclohexane derivative as an essential component.

[0032] The bis(isocyanate methyl)cyclohexane derivatives include urethane derivatives of bis(isocyanate methyl)cyclohexane and isocyanurate derivatives of bis(isocyanate methyl)cyclohexane.

[0033] Such bis(isocyanate-methyl)cyclohexane derivatives are, for example, the reaction products of bis(isocyanate-methyl)cyclohexane monomer and alcohol. More specifically, bis(isocyanate-methyl)cyclohexane derivatives are produced, for example, by the following method: In this method, firstly, the bis(isocyanate-methyl)cyclohexane monomer is reacted with an alcohol.

[0034] Examples of bis(isocyanate methyl)cyclohexane monomers include 1,2-bis(isocyanate methyl)cyclohexane, 1,3-bis(isocyanate methyl)cyclohexane and 1,4-bis(isocyanate methyl)cyclohexane.

[0035] These bis(isocyanate methyl)cyclohexane monomers can be used alone or in combination of two or more.

[0036] As a bis(isocyanate methyl)cyclohexane monomer, 1,3-bis(isocyanate methyl)cyclohexane and 1,4-bis(isocyanate methyl)cyclohexane are preferred, and 1,3-bis(isocyanate methyl)cyclohexane is more preferred.

[0037] Examples of alcohols include monohydric alcohols, dihydric alcohols, and trihydric alcohols.

[0038] Examples of monohydric alcohols include straight-chain monohydric alcohols and branched monohydric alcohols.

[0039] Examples of straight-chain monohydric alcohols include methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol, n-tetradecanol, n-pentadecanol, n-hexadecanol, n-heptadecanol, n-octadecanol, n-nonadecanol, and eicosanool. They can be used alone or in combination of two or more.

[0040] Examples of branched monohydric alcohols include isopropanol, isobutanol (isobutyl alcohol), sec-butanol, tert-butanol, isoamyl alcohol, isohexanol, isoheptanol, isooctanol, 2-ethylhexane-1-ol, isononanol, isodecanol, 5-ethyl-2-nonanol, trimethylnonanol, 2-hexyldecanol, 3,9-diethyl-6-tridecaneol, 2-isoheptylisoundecaneol, and 2-octyldodecaneol. These monohydric alcohols can be used alone or in combination of two or more.

[0041] Examples of diols include straight-chain diols and branched diols.

[0042] Examples of straight-chain diols include, for example, straight-chain alkane diols. Examples of straight-chain alkane diols include, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-dihydroxy-2-butene, diethylene glycol, triethylene glycol, and dipropylene glycol. They can be used alone or in combination of two or more.

[0043] Examples of branched diols include, for example, branched alkane diols. Examples of branched alkane diols include, for example, 1,2-propanediol, 1,3-butanediol, 1,2-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,2-trimethylpentanediol, 3,3-dihydroxymethylheptane, and 2,6-dimethyl-1-octene-3,8-diol. They can be used alone or in combination of two or more.

[0044] These diols can be used alone or in combination of two or more.

[0045] Examples of triols include glycerol, trimethylolpropane, and triisopropanolamine. They can be used alone or in combination of two or more.

[0046] These triols can be used alone or in combination of two or more.

[0047] These alcohols can be used alone or in combination of two or more.

[0048] The alcohol has 1 or more carbon atoms, preferably 2 or more. Furthermore, the alcohol has 50 or fewer carbon atoms, preferably 40 or fewer, more preferably 30 or fewer, even more preferably 20 or fewer, even more preferably 10 or fewer, and particularly preferably 4 or fewer.

[0049] If the number of carbon atoms in the alcohol is within the above range, the water dispersibility of the bis(isocyanate methyl)cyclohexane derivative can be improved.

[0050] As alcohols, monohydric alcohols are preferred, branched monohydric alcohols are more preferred, and isobutanol is even more preferred. By using these components, the water dispersibility of bis(isocyanate methyl)cyclohexane derivatives can be improved.

[0051] The ratio of bis(isocyanate methyl)cyclohexane monomer to alcohol can be suitably set within a range that does not hinder the excellent effects of the present invention.

[0052] More specifically, the isocyanate group equivalence ratio (NCO / OH) of the bis(isocyanate methyl)cyclohexane monomer relative to the hydroxyl group of the alcohol is, for example, higher than 1, preferably 5 or more, and more preferably 10 or more. Furthermore, the isocyanate group equivalence ratio (NCO / OH) of the bis(isocyanate methyl)cyclohexane monomer relative to the hydroxyl group of the alcohol is, for example, 1000 or less, preferably 600 or less, more preferably 500 or less, and even more preferably 100 or less.

[0053] Furthermore, relative to 100 parts by mass of the bis(isocyanate methyl)cyclohexane monomer, the alcohol content is, for example, 3 parts by mass or more, preferably 3.2 parts by mass or more, and more preferably 3.5 parts by mass or more. Additionally, relative to 100 parts by mass of the bis(isocyanate methyl)cyclohexane monomer, the alcohol content is, for example, 50 parts by mass or less, preferably 20 parts by mass or less, and more preferably 10 parts by mass or less.

[0054] The reaction conditions between the bis(isocyanate-methyl)cyclohexane monomer and the alcohol can be suitably set within a range that does not hinder the excellent effects of the present invention. More specifically, the environmental conditions are an inactive atmosphere and normal pressure. Furthermore, the reaction temperature is, for example, 20°C or higher, preferably 40°C or higher. Additionally, the reaction temperature is, for example, 100°C or lower, preferably 90°C or lower. Furthermore, the reaction time is, for example, 0.05 hours or higher, preferably 0.2 hours or higher. Furthermore, the reaction time is, for example, 10 hours or lower, preferably 6 hours or lower.

[0055] Furthermore, in this method, a carbamate catalyst can be incorporated into the bis(isocyanate methyl)cyclohexane monomer and the alcohol, as needed. Examples of carbamate catalysts include known amines and known organometallic compounds. It should be noted that the proportion of the carbamate catalyst is not particularly limited and can be appropriately set according to the purpose and application.

[0056] Therefore, the bis(isocyanate-methyl)cyclohexane monomer undergoes a carbamate reaction with an alcohol. The result is the carbamate reaction product.

[0057] Next, in this method, the carbamate product is subjected to urea-formate esterification and isocyanurate esterification.

[0058] More specifically, in this method, a urethane-isocyanurate esterification catalyst is incorporated into the carbamate esterification reaction product and heated.

[0059] As a catalyst for urea-isocyanurate esterification, there are no particular limitations as long as the catalyst can promote the urea-isocyanurate esterification and isocyanurate esterification of the isocyanate group. Examples of urea-isocyanurate esterification catalysts include tertiary amines, Mannich bases, Friedel-Cleffford catalysts, metal salts of alkyl carboxylic acids, organometallic compounds, halogenated organophosphorus compounds, tetraalkylammonium hydroxides, tetraalkylammonium organic weak acid salts, trialkylhydroxyalkylammonium hydroxides, and trialkylhydroxyalkylammonium organic weak acid salts. They can be used alone or in combination of two or more.

[0060] As a catalyst for the urethane-isocyanurate esterification, an organic weak acid salt of trialkylhydroxyalkylammonium is preferred.

[0061] Examples of trialkylhydroxyalkylammoniums include N-(2-hydroxypropyl)-N,N,N-trimethylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, and triethylhydroxyethylammonium. They can be used alone or in combination of two or more.

[0062] In addition, examples of organic weak acid salts include acetate, propionate, 2-ethylhexanoate, octanoate, decanoate, myristate, and benzoate. They can be used alone or in combination of two or more.

[0063] The proportion of the urethane-isocyanurate esterification catalyst relative to 100 parts by weight of the bis(isocyanate-methyl)cyclohexane monomer is, for example, 0.0005 parts by weight or more, preferably 0.001 parts by weight or more. Furthermore, the proportion of the urethane-isocyanurate esterification catalyst relative to 100 parts by weight of the bis(isocyanate-methyl)cyclohexane monomer is, for example, 0.3 parts by weight or less, preferably 0.05 parts by weight or less, more preferably 0.03 parts by weight or less.

[0064] The reaction conditions for the urea-formylation and isocyanurate esterification reactions can be suitably set within a range that does not hinder the excellent effects of the present invention. More specifically, the environmental conditions are an inert atmosphere and normal pressure. Furthermore, the reaction temperature is, for example, 0°C or higher, preferably 20°C or higher. Additionally, the reaction temperature is, for example, 160°C or lower, preferably 120°C or lower. Furthermore, the reaction time is, for example, 30 minutes or more, preferably 60 minutes or more.

[0065] In addition, the reaction time is, for example, less than 20 hours, preferably less than 10 hours.

[0066] Then, at the point when the reaction rate (isocyanate group conversion) of the reaction solution reaches a predetermined value, a reaction terminator is added to the reaction solution. The isocyanate group conversion rate at which the reaction stops is, for example, 1% by mass or more, preferably 5% by mass or more. Furthermore, the isocyanate group conversion rate at which the reaction stops is, for example, 20% by mass or less, preferably 15% by mass or less. It should be noted that the isocyanate group conversion rate can be calculated using known methods.

[0067] Examples of reaction terminators include phosphoric acid, monochloroacetic acid, benzoyl chloride, dodecylbenzenesulfonic acid, o-toluenesulfonic acid, p-toluenesulfonic acid, methyl o-toluenesulfonate, methyl p-toluenesulfonate, o-toluenesulfonamide, and p-toluenesulfonamide. They can be used alone or in combination of two or more. The proportion of reaction terminators can be appropriately set according to the purpose and application.

[0068] Alternatively, a catalyst adsorbent can be added instead of a reaction terminator. Examples of catalyst adsorbents include chelating resins and ion exchange resins. They can be used alone or in combination of two or more. The proportion of catalyst adsorbents can be appropriately set according to the purpose and application.

[0069] Therefore, the urea-formylation reaction and the isocyanurate esterification reaction cease.

[0070] As a result, a composition comprising a urethane derivative containing bis(isocyanate methyl)cyclohexane and an isocyanurate derivative containing bis(isocyanate methyl)cyclohexane is obtained as the reaction product.

[0071] Furthermore, a co-catalyst may be used in each of the above reactions. Examples of co-catalysts include known organic phosphites. Monophosphites are preferred as organic phosphites, and tri(tridecyl) phosphites are more preferred.

[0072] The proportion of the co-catalyst relative to 100 parts by weight of the bis(isocyanate methyl)cyclohexane monomer is, for example, 0.01 parts by weight or more, preferably 0.02 parts by weight or more, and more preferably 0.03 parts by weight or more. Furthermore, the proportion of the co-catalyst relative to 100 parts by weight of the bis(isocyanate methyl)cyclohexane monomer is, for example, 0.2 parts by weight or less, preferably 0.15 parts by weight or less, and more preferably 0.1 parts by weight or less.

[0073] In addition, reaction stabilizers may be added to the reactions described above. Examples of reaction stabilizers include known hindered phenolic antioxidants. 2,6-Di(tert-butyl)-4-methylphenol (BHT) is a preferred example.

[0074] The proportion of the reaction stabilizer relative to 100 parts by mass of the bis(isocyanate methyl)cyclohexane monomer is, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more.

[0075] In addition, the proportion of the reaction stabilizer relative to 100 parts by weight of the bis(isocyanate methyl)cyclohexane monomer is, for example, 1.0 parts by weight or less, preferably 0.10 parts by weight or less.

[0076] In addition, known reaction solvents can be added to the above reactions. It should be noted that the proportions of the reaction solvents can be appropriately set according to the purpose and application. Furthermore, the reaction solution can be purified in the above reactions. Examples of purification methods include distillation and extraction. Purification removes unreacted bis(isocyanate methyl)cyclohexane monomer from the reaction solution. Additionally, the carbamate catalyst, isocyanurate catalyst, catalyst deactivator, co-catalyst, reaction stabilizer, and / or reaction solvent are removed along with the bis(isocyanate methyl)cyclohexane monomer.

[0077] Moreover, in the above reaction, bis(isocyanate methyl)cyclohexane undergoes isocyanurate modification simultaneously with urethane modification.

[0078] That is, in the above reaction, urethane derivatives of bis(isocyanate methyl)cyclohexane and isocyanurate derivatives of bis(isocyanate methyl)cyclohexane are generated.

[0079] In the bis(isocyanate-methyl)cyclohexane derivative, the proportion of the urea-formate derivative relative to the total amount of the urea-formate derivative and the isocyanurate derivative is, for example, 25% by mass or more, preferably 30% by mass or more, more preferably 35% by mass or more, further preferably 40% by mass or more, and especially preferably 45% by mass or more. Furthermore, the proportion of the urea-formate derivative relative to the total amount of the urea-formate derivative and the isocyanurate derivative is, for example, 75% by mass or less, preferably 70% by mass or less, more preferably 65% ​​by mass or less, further preferably 60% by mass or less, and especially preferably 55% by mass or less.

[0080] If the proportion of urea-formaldehyde derivative exceeds the lower limit mentioned above, a water-dispersible polyisocyanate with excellent curability and water dispersibility can be obtained. Conversely, if the proportion of urea-formaldehyde derivative is below the upper limit mentioned above, a polyurethane resin with excellent hardness can be obtained.

[0081] Furthermore, relative to the total amount of urea-formate derivatives and isocyanurate derivatives, the content of isocyanurate derivatives is, for example, 25% by mass or more, preferably 30% by mass or more, more preferably 35% by mass or more, further preferably 40% by mass or more, and especially preferably 45% by mass or more. Additionally, relative to the total amount of urea-formate derivatives and isocyanurate derivatives, the content of isocyanurate derivatives is, for example, 75% by mass or less, preferably 70% by mass or less, more preferably 65% ​​by mass or less, further preferably 60% by mass or less, and especially preferably 55% by mass or less.

[0082] If the content ratio of isocyanurate derivatives is within the above range, a water-dispersible polyisocyanate with excellent hardness, curability, and water dispersibility can be obtained.

[0083] It should be noted that the proportions of urethane derivatives and isocyanurate derivatives were determined by gel permeation chromatography according to the examples described later.

[0084] Furthermore, in the above method, both a urethane derivative of bis(isocyanate-methyl)cyclohexane and an isocyanurate derivative of bis(isocyanate-methyl)cyclohexane are produced simultaneously. However, for example, the urethane derivative of bis(isocyanate-methyl)cyclohexane and the isocyanurate derivative of bis(isocyanate-methyl)cyclohexane can be produced separately and mixed in the above proportions. Alternatively, the urethane derivative of bis(isocyanate-methyl)cyclohexane and / or the isocyanurate derivative of bis(isocyanate-methyl)cyclohexane can be added to the above-mentioned bis(isocyanate-methyl)cyclohexane derivative and adjusted to the above proportions.

[0085] In addition, the polyisocyanate component may include other polyisocyanates as optional ingredients.

[0086] Other polyisocyanates are polyisocyanates other than bis(isocyanate methyl)cyclohexane derivatives.

[0087] More specifically, bis(isocyanate methyl)cyclohexane monomers can be cited as other polyisocyanates.

[0088] In addition, other polyisocyanates that are widely used in industry can be cited as examples. These include, for instance, aromatic polyisocyanates, aromatic aliphatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates (excluding bis(isocyanatomethyl)cyclohexane). Furthermore, industrially widely used polyisocyanates include derivatives of the same type as those described above.

[0089] Other polyisocyanates can be used alone or in combination of two or more.

[0090] The proportion of other polyisocyanates relative to the total amount of polyisocyanate components is, for example, 90% by mass or less, preferably 70% by mass or less, more preferably 50% by mass or less, even more preferably 30% by mass or less, even more preferably 10% by mass or less, and especially preferably 0% by mass.

[0091] That is, the polyisocyanate component is preferably composed of bis(isocyanate methyl)cyclohexane derivatives, and does not contain other polyisocyanates.

[0092] When the polyisocyanate component is composed of a bis(isocyanate methyl)cyclohexane derivative, a water-dispersible polyisocyanate with particularly excellent hardness, curability, and water dispersibility can be obtained.

[0093] Furthermore, the polyisocyanate component can be dissolved in known organic solvents. In such cases, the solid content concentration of the polyisocyanate component is, for example, 10% by mass or more, preferably 20% by mass or more. Additionally, the solid content concentration of the polyisocyanate component is, for example, 90% by mass or less, preferably 80% by mass or less.

[0094] Then, the above-mentioned polyisocyanate component is reacted with the hydrophilic active hydrogen component described later to obtain a water-dispersible polyisocyanate.

[0095] More specifically, in the preparation of water-dispersible polyisocyanates, the polyisocyanate component and the hydrophilic active hydrogen component are reacted in a ratio in which free isocyanate groups remain.

[0096] Hydrophilic active hydrogen components include active hydrogen compounds containing sulfonyl groups.

[0097] A sulfonate-containing active hydrogen compound is a compound containing one or more sulfonates and one or more active hydrogen groups. Examples of active hydrogen groups include hydroxyl and amino groups.

[0098] Examples of sulfonate-containing active hydrogen compounds include compounds that simultaneously possess one active hydrogen group and one sulfonate group. Examples of such sulfonate-containing active hydrogen compounds include hydroxyalkane sulfonic acids and aminosulfonic acids.

[0099] Examples of hydroxyalkyl sulfonic acids include hydroxymethanesulfonic acid, hydroxyethanesulfonic acid, and 3-hydroxypropanesulfonic acid. They can be used alone or in combination of two or more.

[0100] Examples of aminosulfonic acids include 2-(cyclohexylamino)-ethanesulfonic acid (CHES) and 3-(cyclohexylamino)-propanesulfonic acid (CAPS). They can be used alone or in combination of two or more.

[0101] These sulfonated active hydrogen compounds can be used alone or in combination of two or more.

[0102] As an active hydrogen compound containing a sulfonyl group, aminosulfonic acid is preferred, and 3-(cyclohexylamino)-propanesulfonic acid is more preferred.

[0103] In addition, the hydrophilic active hydrogen component may include other water-dispersible active hydrogen compounds as optional components.

[0104] Other water-dispersible active hydrogen compounds are water-dispersible active hydrogen compounds other than those containing sulfonyl groups.

[0105] Other water-dispersible active hydrogen compounds include, more specifically, active hydrogen compounds containing nonionic groups, active hydrogen compounds containing carboxyl groups, and active hydrogen compounds containing phosphate groups.

[0106] Examples of active hydrogen compounds containing nonionic groups include polyoxyethylene compounds.

[0107] Examples of polyoxyethylene compounds include compounds that simultaneously possess active hydrogen groups and at least three consecutive vinyl oxides. Examples of such polyoxyethylene compounds include single-terminated polyoxyethylene glycols and diols containing polyoxyethylene side chains.

[0108] Examples of single-end-sealable polyethylene glycols include alkoxy polyethylene glycols obtained by sealing the single end with alkyl groups having 1 to 20 carbon atoms. More specifically, examples include methoxy polyethylene glycols and ethoxy polyethylene glycols. Single-end-sealable polyethylene glycols can be manufactured using known methods.

[0109] Examples of diols containing polyoxyethylene side chains include, for instance, polyoxyethylene monoisocyanates and reaction products with dialkyl alcohol amines. Diols containing polyoxyethylene side chains can be manufactured using known methods.

[0110] Polyoxyethylene compounds can be used alone or in combination of two or more.

[0111] The number average molecular weight of the polyoxyethylene compound is, for example, 200 or more, preferably 300 or more, for example, 2000 or less, and preferably 1000 or less.

[0112] A carboxyl-containing active hydrogen compound is a compound that simultaneously possesses an active hydrogen group and a carboxyl group. Examples of carboxyl-containing active hydrogen compounds include those possessing one active hydrogen group and one carboxyl group. Furthermore, examples of carboxyl-containing active hydrogen compounds include those possessing two active hydrogen groups and one carboxyl group.

[0113] Examples of carboxyl-containing active hydrogen compounds that simultaneously possess one active hydrogen group and one carboxyl group include glycolic acid, lactic acid, hydroxypentanoic acid, malic acid, and citric acid.

[0114] Examples of carboxyl-containing active hydrogen compounds that simultaneously possess two active hydrogen groups and one carboxyl group include 2,2-dihydroxymethylacetic acid, 2,2-dihydroxymethyllactic acid, 2,2-dihydroxymethylpropionic acid, 2,2-dihydroxymethylbutyric acid, dihydroxymethylheptanoic acid, dihydroxymethylnonanoic acid, 2,2-dihydroxymethylbutyric acid, and 2,2-dihydroxymethylvaleric acid.

[0115] Carboxyl-containing active hydrogen compounds can be used alone or in combination of two or more.

[0116] Active hydrogen compounds containing phosphate groups are compounds that simultaneously possess both active hydrogen groups and phosphate groups.

[0117] Examples of active hydrogen compounds containing phosphate groups include active hydrogen compounds containing phosphate groups that simultaneously have one active hydrogen group and one phosphate group.

[0118] Examples of such phosphoric acid-containing active hydrogen compounds include hydroxyalkylphosphonic acids and aminoalkylphosphonic acids.

[0119] Phosphoric acid-containing active hydrogen compounds can be used alone or in combination of two or more.

[0120] Other water-dispersible active hydrogen compounds can be used alone or in combination of two or more.

[0121] The proportion of other water-dispersible active hydrogen compounds relative to the total amount of hydrophilic active hydrogen components is, for example, 90% by mass or less, preferably 70% by mass or less, more preferably 50% by mass or less, even more preferably 30% by mass or less, even more preferably 10% by mass or less, and especially preferably 0% by mass.

[0122] That is, the hydrophilic active hydrogen component is preferably composed of sulfonated active hydrogen compounds, and does not contain other water-dispersible active hydrogen compounds.

[0123] When the hydrophilic active hydrogen component is composed of sulfonated active hydrogen compounds, a water-dispersible polyisocyanate with particularly excellent hardness and mechanical properties, as well as excellent curability and water dispersibility, can be obtained.

[0124] The reaction ratio of the polyisocyanate component to the hydrophilic active hydrogen component is adjusted in such a way that free isocyanate groups remain in the reaction product.

[0125] More specifically, the equivalent ratio (active hydrogen groups / NCO) of the active hydrogen groups of the hydrophilic active hydrogen component to the isocyanate groups of the polyisocyanate component is, for example, 0.30 or less, preferably 0.20 or less. Furthermore, the equivalent ratio (active hydrogen groups / NCO) of the active hydrogen groups of the hydrophilic active hydrogen component to the isocyanate groups of the polyisocyanate component is, for example, 0.01 or more, preferably 0.10 or more.

[0126] The proportion of the hydrophilic active hydrogen component relative to 100 parts by weight of the polyisocyanate component is, for example, 10 parts by weight or more, preferably 20 parts by weight or more, and more preferably 25 parts by weight or more. Furthermore, the proportion of the hydrophilic active hydrogen component relative to 100 parts by weight of the polyisocyanate component is, for example, 70 parts by weight or less, preferably 60 parts by weight or less, and more preferably 55 parts by weight or less.

[0127] The reaction conditions between the polyisocyanate component and the hydrophilic active hydrogen component can be suitably set within a range that does not hinder the excellent effects of the present invention. More specifically, the environmental conditions are an inactive atmosphere and normal pressure. Furthermore, the reaction temperature is, for example, 50°C or higher, preferably 70°C or higher. Additionally, the reaction temperature is, for example, 150°C or lower, preferably 110°C or lower. Furthermore, the reaction time is, for example, 0.5 hours or higher, preferably 1 hour or higher. Additionally, the reaction time is, for example, 120 hours or lower, preferably 72 hours or lower.

[0128] It should be noted that the end of the reaction is confirmed, for example, by the absence of change in the amount of isocyanate in the reaction solution. The amount of isocyanate is determined using titration or infrared absorption.

[0129] Furthermore, in this method, it is preferable to add a neutralizing agent to the reaction solution to form a sulfonated salt. That is, the sulfonated group may or may not be a salt. Preferably, a sulfonated salt can be used as the sulfonated group.

[0130] Commonly used bases can be cited as neutralizing agents. Specifically, organic bases and inorganic bases can be cited as bases.

[0131] 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. Examples of heterocyclic amines include morpholine. These organic bases can be used alone or in combination of two or more.

[0132] 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 inorganic bases can be used alone or in combination of two or more.

[0133] These neutralizing agents can be used alone or in combination of two or more.

[0134] As a neutralizing agent, an organic base is preferred, a tertiary amine is more preferred, a trialkylamine is even more preferred, and N,N-dimethylcyclohexylamine is particularly preferred.

[0135] The amount of neutralizing agent added relative to 1 sulfonyl equivalent is, for example, 0.4 equivalents or more, preferably 0.6 equivalents or more. Furthermore, the amount of neutralizing agent added relative to 1 sulfonyl equivalent is, for example, 1.2 equivalents or less, preferably 1.0 equivalents or less.

[0136] Thus, a water-dispersible polyisocyanate containing isocyanate and sulfonate groups was obtained.

[0137] Furthermore, in water-dispersible polyisocyanates, the isocyanate group can be a free isocyanate group. Alternatively, the isocyanate group can be blocked using a capping agent. That is, examples of isocyanate groups include both free isocyanate groups and blocked isocyanate groups.

[0138] The capping agent is a compound having an active group (hereinafter referred to as the blocking group) that reacts with an isocyanate group. Examples of capping agents include active methylene compounds, active methine compounds, imidazole compounds, imidazoline compounds, pyrimidine compounds, guanidine compounds, alcohol compounds, phenol compounds, amine compounds, imine compounds, oxime compounds, carbamic acid compounds, urea compounds, amide compounds, lactam compounds, imide compounds, triazole compounds, pyrazole compounds, thiol compounds, and bisulfites. They can be used alone or in combination of two or more. Imidazole compounds, imidazoline compounds, oxime compounds, and pyrazole compounds are preferred as capping agents.

[0139] Then, a water-dispersible polyisocyanate having free isocyanate groups is reacted with the above-mentioned capping agent to generate a water-dispersible polyisocyanate having blocked isocyanate groups.

[0140] The proportion of a water-dispersible polyisocyanate having free isocyanate groups to the above-mentioned capping agent is adjusted, for example, based on the equivalent ratio of the isocyanate groups in the water-dispersible polyisocyanate to the blocking groups in the capping agent.

[0141] More specifically, the equivalence ratio of the blocked group to the free isocyanate group (blocked 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. Furthermore, the equivalence ratio of the blocked group to the free isocyanate group (blocked group / isocyanate group) is, for example, 1.5 or less, preferably 1.2 or less, and more preferably 1.1 or less.

[0142] The reaction conditions of the water-dispersible polyisocyanate having free isocyanate groups and the above-mentioned capping agent can be suitably set within a range that does not hinder the excellent effects of the present invention. More specifically, the environmental conditions are an inactive atmosphere and normal pressure. Furthermore, the reaction temperature is, for example, 0°C or higher, preferably 20°C or higher. Additionally, the reaction temperature is, for example, 100°C or lower, preferably 80°C or lower, more preferably 70°C or lower. Furthermore, the reaction time is, for example, 0.5 hours or higher, preferably 1.0 hour or higher. Furthermore, the reaction time is, for example, 24 hours or lower, preferably 12 hours or lower.

[0143] It should be noted that the end of the reaction is confirmed, for example, by the absence of change in the amount of isocyanate in the reaction solution. The amount of isocyanate is determined using titration or infrared absorption.

[0144] Furthermore, all of the above reactions can be carried out under solvent-free conditions. Alternatively, all of the above reactions can be carried out in the presence of a solvent. Known organic solvents can be cited as examples. Furthermore, the proportions of the solvent can be appropriately set according to the purpose and application.

[0145] Alternatively, when using a solvent, the solvent can be removed after the reaction is complete. Examples of methods for removing the solvent include distillation and extraction.

[0146] It should be noted that, in the following text, isocyanate group refers to both free isocyanate group and isocyanate group that has been blocked by a capping agent.

[0147] The average isocyanate base number in the water-dispersible polyisocyanate is, for example, 2 or more, preferably 2.2 or more, for example, 4.0 or less, preferably 3.5 or less.

[0148] Furthermore, relative to the total amount of water-dispersible polyisocyanate, the content of isocyanate groups is, for example, 5% by mass or more, preferably 7% by mass or more. Additionally, relative to the total amount of water-dispersible polyisocyanate, the content of isocyanate groups is, for example, 30% by mass or less, preferably 25% by mass or less, and more preferably 20% by mass or less.

[0149] Furthermore, relative to the total amount of the water-dispersible polyisocyanate, the content of sulfonyl 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. Additionally, relative to the total amount of the water-dispersible polyisocyanate, the content of sulfonyl 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.

[0150] If the proportion of sulfonium groups exceeds the lower limit mentioned above, particularly excellent water dispersibility can be obtained. Conversely, if the proportion of sulfonium groups is below the upper limit mentioned above, particularly excellent water resistance can be obtained.

[0151] It should be noted that the proportion of sulfonyl groups can be calculated from the chemical structural formula and formulation according to the examples described later.

[0152] In addition, when the water-dispersible polyisocyanate contains oxyethylene units, its content relative to the total amount of water-dispersible polyisocyanate 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.

[0153] It should be noted that the proportion of ethylene oxide units can be calculated from the chemical structural formula and formulation according to the examples described later.

[0154] Furthermore, the acid value of the water-dispersible polyisocyanate 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. Additionally, the acid value of the water-dispersible polyisocyanate 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.

[0155] It should be noted that the acid value is determined according to JIS K 1557-5 (2007). Alternatively, the acid value can be calculated by determining the sulfonyl content of the water-dispersible polyisocyanate based on the amount of raw material input.

[0156] If the acid value of the water-dispersible polyisocyanate exceeds the lower limit mentioned above, particularly excellent water dispersibility can be obtained. Furthermore, if the acid value of the water-dispersible polyisocyanate is lower than the upper limit mentioned above, particularly excellent water resistance can be obtained.

[0157] Furthermore, the aforementioned water-dispersible polyisocyanate comprises a reaction product of a polyisocyanate component and a hydrophilic active hydrogen component, wherein the polyisocyanate component comprises a bis(isocyanate-methyl)cyclohexane derivative, and the hydrophilic active hydrogen component comprises an active hydrogen compound containing a sulfonate group. Moreover, the bis(isocyanate-methyl)cyclohexane derivative comprises a urethane derivative and an isocyanurate derivative, with the urethane derivative comprising a specified proportion.

[0158] Therefore, the above-mentioned water-dispersible polyisocyanates can produce polyurethane resins with excellent hardness, as well as excellent curability and water dispersibility.

[0159] The waterborne polyurethane resin composition comprises the above-mentioned water-dispersible polyisocyanate and a compound containing active hydrogen groups. It should be noted that the waterborne polyurethane resin composition can be a one-component curing polyurethane resin composition prepared by mixing the water-dispersible polyisocyanate and the compound containing active hydrogen groups. Alternatively, the polyurethane resin composition can also be a two-component curing polyurethane resin composition in which the water-dispersible polyisocyanate and the compound containing active hydrogen groups are prepared separately and then combined during use.

[0160] The waterborne polyurethane resin composition is preferably a two-component curing polyurethane resin composition.

[0161] The two-component curable polyurethane resin composition contains a compound containing active hydrogen groups as a main agent. Additionally, the two-component curable polyurethane resin composition contains the aforementioned water-dispersible polyisocyanate as a curing agent.

[0162] The main agent comprises, for example, an aqueous dispersion of a compound containing an active hydrogen group.

[0163] Examples of compounds containing active hydrogen groups include macromolecular polyols. Macromolecular polyols are organic compounds (polymers) with a relatively high molecular weight and two or more hydroxyl groups in their molecules. It should be noted that the number average molecular weight of macromolecular polyols is, for example, higher than 600, but for example, lower than 20,000.

[0164] Examples of macromolecular polyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. They can be used alone or in combination of two or more.

[0165] These compounds containing active hydrogen groups can be used alone or in combination of two or more.

[0166] Aqueous dispersions of compounds containing active hydrogen groups can be prepared, for example, by adding water to the compound containing active hydrogen groups. Alternatively, aqueous dispersions of compounds containing active hydrogen groups can also be prepared, for example, by adding the compound containing active hydrogen groups to water.

[0167] In an aqueous dispersion of a compound containing an active hydrogen group, the proportion of the compound containing the active hydrogen group can be suitably set according to the purpose and application. For example, relative to the total amount of the aqueous dispersion, the compound containing the active hydrogen group (solid component) is, for example, 1% by mass or more, preferably 5% by mass or more. In addition, relative to the total amount of the aqueous dispersion, the compound containing the active hydrogen group (solid component) is, for example, 30% by mass or less, preferably 20% by mass or less.

[0168] The curing agent contains, for example, an aqueous dispersion of a water-dispersible polyisocyanate.

[0169] Aqueous dispersions of water-dispersible polyisocyanates can be prepared, for example, by adding water to the water-dispersible polyisocyanate. Alternatively, aqueous dispersions of water-dispersible polyisocyanates can also be prepared, for example, by adding water-dispersible polyisocyanates to water. Furthermore, known external emulsifiers can be added to water and / or the water-dispersible polyisocyanate as needed. Additionally, known external emulsifiers can be added to mixtures of water and water-dispersible polyisocyanates.

[0170] In an aqueous dispersion of a water-dispersible polyisocyanate, the proportion of the water-dispersible polyisocyanate can be suitably set according to the purpose and application. For example, relative to the total amount of the aqueous dispersion, the water-dispersible polyisocyanate (solid component) is, for example, 1% by mass or more, preferably 5% by mass or more. Furthermore, relative to the total amount of the aqueous dispersion, the water-dispersible polyisocyanate (solid component) is, for example, 30% by mass or less, preferably 20% by mass or less.

[0171] It should be noted that if an aqueous dispersion of a compound containing active hydrogen groups has been prepared, it is not necessary to prepare an aqueous dispersion of the water-dispersible polyisocyanate. That is, the solid component of the water-dispersible polyisocyanate can be used directly.

[0172] Furthermore, when preparing an aqueous dispersion of a water-dispersible polyisocyanate, it is not necessary to prepare an aqueous dispersion of a compound containing active hydrogen groups. That is, the solid component of the compound containing active hydrogen groups can be used directly.

[0173] In addition, the waterborne polyurethane resin composition may contain additives. Examples of additives include catalysts, solvents, epoxy resins, coatability modifiers, leveling agents, defoamers, antioxidants, UV absorbers, thickeners, anti-settling agents, plasticizers, surfactants, pigments, mildew inhibitors, fillers, organic particles, and inorganic particles. Additives may be incorporated into the main agent. Alternatively, additives may be incorporated into the curing agent.

[0174] It should be noted that the amount of additives can be appropriately set according to their purpose and use.

[0175] When using a two-component curing polyurethane resin composition, the main agent and the curing agent are combined.

[0176] The mixing ratio of the main agent and the curing agent is adjusted, for example, based on the equivalent ratio (isocyanate group / hydroxyl group) of the isocyanate group of the water-dispersible polyisocyanate to the active hydrogen group of the compound containing active hydrogen groups.

[0177] More specifically, the equivalence ratio (isocyanate group / active hydrogen group) of the water-dispersible polyisocyanate to the active hydrogen group of the compound containing active hydrogen groups is, for example, 0.1 or more, preferably 0.5 or more. Furthermore, the equivalence ratio (isocyanate group / active hydrogen group) of the water-dispersible polyisocyanate to the active hydrogen group of the compound containing active hydrogen groups is, for example, 5 or less, preferably 3 or less.

[0178] Then, the mixture of the base agent and the curing agent is applied to any substrate using a known coating method and dried under any drying conditions. Examples of coating methods include spray coating, dip coating, spin coating, rotary atomization coating, and curtain coating.

[0179] This forms a coating of the waterborne polyurethane resin composition. The coating is then cured by heating.

[0180] The heating conditions can be appropriately set according to the main agent and the curing agent. For example, if the isocyanate groups of the curing agent are not sealed using a capping 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. Furthermore, the heating time is, for example, 1 minute or more, preferably 5 minutes or more. Additionally, the heating time is, for example, 24 hours or less, preferably 12 hours or less.

[0181] Thus, a polyurethane resin is obtained as a cured product formed from the aqueous polyurethane resin composition. Furthermore, an article comprising a coated object and a polyurethane layer is obtained. More specifically, the article comprises a coated object and a polyurethane layer disposed on the surface of the coated object, the polyurethane layer comprising a cured coating film of the aforementioned aqueous polyurethane resin composition. Additionally, the polyurethane resin can be cured under any conditions as needed.

[0182] It should be noted that when the isocyanate groups of the water-dispersible polyisocyanate are blocked using a capping agent, the waterborne polyurethane resin composition is preferably a one-liquid curing polyurethane resin composition. In this case, the mixing ratio of the water-dispersible polyisocyanate to the compound containing active hydrogen groups is the same as that in the above-mentioned two-liquid curing polyurethane resin composition.

[0183] Furthermore, the above-described waterborne polyurethane resin composition contains the aforementioned water-dispersible polyisocyanate. Therefore, the above-described waterborne polyurethane resin composition can yield a polyurethane resin with excellent hardness and excellent curability.

[0184] Furthermore, the aforementioned articles comprise a cured coating of the aforementioned aqueous polyurethane resin composition, thus possessing a polyurethane layer with excellent hardness.

[0185] Therefore, the above-mentioned water-dispersible polyisocyanate, waterborne polyurethane resin composition and articles are preferably used in, for example, automotive exterior trim, surface resin coatings for household electrification products, and flexible printing inks for flexible packaging.

[0186] Example

[0187] The following examples illustrate the invention in more detail, but the invention is not limited thereto. The specific numerical values ​​of proportions (including ratios), physical property values, parameters, etc., used in the following description can be replaced with the corresponding upper limit values ​​(defined in the form of "below" or "lower") or lower limit values ​​(defined in the form of "above" or "higher") of the proportions (including ratios), physical property values, parameters, etc., described in the "Specific Embodiments" above. It should be noted that, unless otherwise specified, "parts" and "%" are based on mass.

[0188] Synthesis Example 1 (Preparation of Polyisocyanate A)

[0189] 2000.0 g of 1,3-bis(isocyanate-methyl)cyclohexane (1,3-H6XDI, TAKENATE 600, manufactured by Mitsui Chemicals) and 76.4 g of isobutanol were added to a four-necked flask equipped with a stirrer, thermometer, reflux tube, and nitrogen inlet tube. The mixture was subjected to a carbamate reaction at 80°C for 2 hours. It should be noted that the isocyanate group of 1,3-H6XDI has an equivalent ratio (NCO / OH) of 20 to the hydroxyl group of isobutanol.

[0190] Next, 0.52 g of DABCO-TMR (N-(2-hydroxypropyl)-N,N,N-trimethylammonium-2-ethylhexanoate, manufactured by Air Products) was added to the obtained reaction solution as a catalyst for urethane-isocyanurate esterification, and the reaction was carried out at 80-86°C for 2 hours.

[0191] Then, by determining the isocyanate group content, it was confirmed that 10% of the isocyanate groups had been converted. Next, 0.60 g of o-toluenesulfonic acid was added to the reaction solution to stop the reaction.

[0192] The reaction solution was distilled using a thin-film distillation apparatus (vacuum of 0.05 kPa, temperature of 140 °C) to remove unreacted 1,3-H6XDI. The remaining components were then dissolved in propylene glycol methyl ether acetate (PMA) to achieve a solid concentration of 75.0% by mass. This yielded polyisocyanate A.

[0193] The isocyanate group content (NCO%) of this polyisocyanate A is 13.5%.

[0194] Furthermore, polyisocyanate A was determined using gel permeation chromatography, described later. The results confirmed that polyisocyanate A contained urethane derivatives and isocyanurate derivatives. Moreover, the content of urethane derivatives relative to the total amount of urethane derivatives and isocyanurate derivatives was 50% by mass.

[0195] Synthesis Example 2 (Preparation of Polyisocyanate B)

[0196] 2000.0 g of 1,3-bis(isocyanate-methyl)cyclohexane and 38.2 g of isobutanol were used. Except as described above, the procedure was the same as in Synthesis Example 1 to obtain polyisocyanate B. It should be noted that the equivalent ratio (NCO / OH) of the isocyanate group of 1,3-H6XDI to the hydroxyl group of isobutanol was 40.

[0197] The isocyanate group content (NCO%) of this polyisocyanate B is 13.4%. Furthermore, the proportion of urea-formate derivatives relative to the total amount of urea-formate derivatives and isocyanurate derivatives is 30% by mass.

[0198] Synthesis Example 3 (Preparation of Polyisocyanate C)

[0199] 2000.0 g of 1,3-bis(isocyanate-methyl)cyclohexane and 101.8 g of isobutanol were used. Except as described above, the procedure was the same as in Synthesis Example 1 to obtain polyisocyanate C. It should be noted that the equivalence ratio (NCO / OH) of the isocyanate group of 1,3-H6XDI to the hydroxyl group of isobutanol was 15.

[0200] The isocyanate group content (NCO%) of this polyisocyanate C is 14.5%. Furthermore, the proportion of urea-formate derivatives relative to the total amount of urea-formate derivatives and isocyanurate derivatives is 70% by mass.

[0201] Synthesis Example 4 (Preparation of Polyisocyanate D)

[0202] 2000.0 g of 1,3-bis(isocyanate-methyl)cyclohexane and 46.4 g of 1,3-butanediol were used. Except as described above, the procedure was the same as in Synthesis Example 1 to obtain polyisocyanate D. It should be noted that the equivalent ratio (NCO / OH) of the isocyanate group of 1,3-H6XDI to the hydroxyl group of 1,3-butanediol was 20.

[0203] The isocyanate group content (NCO%) of this polyisocyanate D is 14.1%. Furthermore, the proportion of urea-formate derivatives relative to the total amount of urea-formate derivatives and isocyanurate derivatives is 50% by mass.

[0204] Synthesis Example 5 (Preparation of Polyisocyanate E)

[0205] 2000.0 g of 1,3-bis(isocyanate-methyl)cyclohexane and 8.5 g of isobutanol were used. Except as described above, the procedure was the same as in Synthesis Example 1 to obtain polyisocyanate E. It should be noted that the equivalence ratio (NCO / OH) of the isocyanate group of 1,3-H6XDI to the hydroxyl group of isobutanol was 180.

[0206] The isocyanate group content (NCO%) of this polyisocyanate E is 15.2%. Furthermore, the proportion of urea-formate derivatives relative to the total amount of urea-formate derivatives and isocyanurate derivatives is 10% by mass.

[0207] Synthesis Example 6 (Preparation of Polyisocyanate F)

[0208] 1924.5 g of 1,3-bis(isocyanate-methyl)cyclohexane and 73.4 g of isobutanol were added to a four-necked flask equipped with a stirrer, thermometer, reflux tube, and nitrogen inlet tube. The mixture was subjected to a carbamate reaction at 75 °C for 3 hours. It should be noted that the isocyanate group of 1,3-H6XDI has an equivalent ratio (NCO / OH) of 20 to the hydroxyl group of isobutanol.

[0209] Next, 0.094 g of NEOSTANN U-600 (18% by mass of bismuth octanoate, manufactured by Nitto Kasei Corporation), used as a catalyst for the urethane-isocyanurate esterification, was added to the reaction solution, and the reaction was carried out at 110°C for 18 hours. Then, 0.062 g of o-toluenesulfonic acid was added to stop the reaction.

[0210] The reaction solution was distilled using a thin-film distillation apparatus (vacuum of 0.05 kPa, temperature of 140 °C) to remove unreacted 1,3-H6XDI. The remaining components were then dissolved in propylene glycol methyl ether acetate (PMA) to achieve a solid content of 75.0% by mass. This yielded polyisocyanate F.

[0211] The isocyanate group content (NCO%) of this polyisocyanate F is 13.2%. Furthermore, the proportion of urea-formate derivatives relative to the total amount of urea-formate derivatives and isocyanurate derivatives is 80% by mass.

[0212] Synthesis Example 7 (Preparation of Polyisocyanate G)

[0213] 2000.0 g of hexamethylene diisocyanate and 2.9 g of isobutanol were used. Except as described above, the procedure was the same as in Synthesis Example 1 to obtain polyisocyanate G. It should be noted that the equivalence ratio (NCO / OH) of the isocyanate group to the hydroxyl group of the isobutanol in the hexamethylene diisocyanate was 600.

[0214] The isocyanate group content (NCO%) of this polyisocyanate G is 17.1%.

[0215] Synthesis Example 8 (Preparation of Polyisocyanate H)

[0216] 2000.0 g of 1,5-pentanediisocyanate and 3.2 g of isobutanol were used. Except as described above, the procedure was the same as in Synthesis Example 1 to obtain polyisocyanate H. It should be noted that the equivalent ratio (NCO / OH) of the isocyanate group of 1,5-pentanediisocyanate to the hydroxyl group of isobutanol was 600.

[0217] The isocyanate group content (NCO%) of this polyisocyanate H is 18.5%.

[0218] Synthesis Example 9 (Preparation of Polyisocyanate I)

[0219] Prepare VESTANAT T-1890 (isophorone diisocyanate trimer, manufactured by Evonik). Use it as polyisocyanate I.

[0220] <Gel Permeation Chromatography (GPC)>

[0221] The molecular weight distribution of each polyisocyanate was determined using the GPC apparatus described below.

[0222] Then, the area ratio of the peak corresponding to the urethane derivative to all peaks is taken as the content of the urethane derivative. The remaining ratio is taken as the content of the isocyanurate derivative.

[0223] It should be noted that when using isobutanol, the peak with a peak in the molecular weight range of 410–510 corresponds to a urethane derivative. Similarly, when using 1,3-butanediol, the peak with a peak in the molecular weight range of 770–870 corresponds to a urethane derivative.

[0224] GPC device:

[0225] Equipment used: HLC-8020 (manufactured by Tosoh)

[0226] The columns used: Connect G1000HXL, G2000HXL and G3000HXL (and above, Tosoh product names) in series.

[0227] Sample concentration: 0.3% by mass, tetrahydrofuran solution

[0228] Sample injection volume: 100 μL

[0229] Eluent: Tetrahydrofuran

[0230] Flow rate of eluent: 0.8 ml / min

[0231] Column temperature: 40℃

[0232] Test method: Differential refractive index

[0233] Standard material: Polyethylene oxide (manufactured by Tosoh, trade name: TSK standard polyethylene oxide)

[0234] Examples 2-9 and Comparative Examples 1-6

[0235] Water-dispersible polyisocyanates were obtained according to the formulations shown in Tables 1 and 2.

[0236] More specifically, the polyisocyanate component is mixed with the hydrophilic active hydrogen component and reacted at 80–90°C for 8 hours under dry nitrogen. Then, a neutralizing agent is added, followed by the addition of solvent to adjust the concentration of the solid component.

[0237] Example 10

[0238] A water-dispersible polyisocyanate with blocked isocyanate groups was obtained according to the formulation shown in Table 3.

[0239] More specifically, the polyisocyanate component is mixed with the hydrophilic active hydrogen component and reacted at 80–90°C for 8 hours under dry nitrogen. Then, a neutralizing agent is added. Dimethylpyrazole is further added to the reaction solution, and the reaction is carried out at 40–50°C. The reaction solution is then stirred for 2 hours until isocyanate groups are no longer detectable using an IR spectrometer (2260 cm⁻¹). -1 So far, the isocyanate group was blocked using dimethylpyrazole.

[0240] Then, the reaction solution, which has been cooled to 30°C, is slowly added to the stirred deionized water.

[0241] Thus, an aqueous dispersion of a water-dispersible polyisocyanate with isocyanate groups blocked was obtained.

[0242] <Acid value (mgKOH / g)>

[0243] The acid value of water-dispersible polyisocyanates was determined according to JIS K 1557-5 (2007).

[0244] <Percentage of sulfonyl groups (SO3 content, mass%)>

[0245] SO3 - The molecular weight was set to 80, and the sulfonate content (SO3 content) in the water-dispersible polyisocyanate was calculated from the chemical structural formula and formulation.

[0246] <Percentage of ethylene oxide units (EO content, mass%)>

[0247] The content of ethylene oxide units can be calculated using the following formula based on the chemical structural formula and formulation.

[0248] ((Methoxy PEG molecular weight - 32) / (Methoxy PEG molecular weight) × (Methoxy PEG dosage) / (Resin component amount) × 100

[0249] <Isocyanate group content (NCO content, mass %)>

[0250] The content of isocyanate groups was determined using a potentiometric titration apparatus by the di-n-butylamine method according to JIS K-1556 (2006).

[0251] <Evaluation>

[0252] (1) Water dispersibility

[0253] Add 5g of the solid component of the water-dispersible polyisocyanate to 95g of water, stir with a magnetic stirrer for 15 minutes, and then let stand for 1 hour. The properties of the mixture are then evaluated according to the following criteria.

[0254] ○: No sediment.

[0255] △: There is sediment, but it can be redispersed by stirring.

[0256] ×: There is sediment, and it cannot be dispersed again.

[0257] (2) Hardness

[0258] Aqueous acrylic emulsion with a hydroxyl value of 50 mg KOH / g (solid component concentration of 40.0% by mass) was diluted with water to a solid component concentration of 25% by mass. This aqueous solution was used as the main agent.

[0259] Each water-dispersible polyisocyanate used as a curing agent was added to the above-mentioned main agent and stirred for 15 minutes. It should be noted that the equivalent ratio (NCO / OH) of the isocyanate groups in the curing agent to the hydroxyl groups in the main agent was 1.0.

[0260] Then, the mixture of the main agent and the curing agent was applied to a glass plate. It should be noted that the coating amount was adjusted to achieve a dry thickness of 20 μm. The coating was then dried at 110°C for 30 minutes and cured at 23°C for 7 days. This yielded the cured film.

[0261] The Koenigsegg hardness of the cured film was measured at 23°C using a pendulum hardness tester from BYK. The hardness was then evaluated according to the following criteria.

[0262] ○: 70 or more

[0263] △: 60 or above and below 70

[0264] ×: Below 60

[0265] (3) Curing properties

[0266] Aqueous acrylic emulsion with a hydroxyl value of 50 mg KOH / g (solid component concentration of 40.0% by mass) was diluted with water to a solid component concentration of 25% by mass. This aqueous solution was used as the main agent.

[0267] Each water-dispersible polyisocyanate used as a curing agent was added to the above-mentioned main agent and stirred for 15 minutes. It should be noted that the equivalent ratio (NCO / OH) of the isocyanate groups in the curing agent to the hydroxyl groups in the main agent was 1.0.

[0268] Then, the mixture of the main agent and the curing agent was applied to a glass plate. It should be noted that the coating amount was adjusted to achieve a dry thickness of 20 μm. The coating was then dried at 110°C for 30 minutes and cured at 23°C for 7 days. This yielded the cured film.

[0269] The cured film was immersed in a mixture of acetone and methanol (mass ratio 1:1) for 24 hours.

[0270] Then, the residual rate of the cured film after impregnation is calculated and evaluated according to the following evaluation criteria.

[0271] ○: Survival rate is over 90%

[0272] △: The survival rate is above 80% but below 90%.

[0273] ×: Survival rate is less than 80%

[0274] (4) Elasticity

[0275] First, the cured film obtained by evaluation method (2) is cut into dimensions of 5 mm in width and 10 cm in length. Thus, a sample is obtained.

[0276] Next, the storage modulus of the sample at 0°C was determined using the following method.

[0277] That is, a dynamic viscoelastic apparatus (manufactured by TA Instruments, model: RSA-III) was used. Furthermore, the measurement conditions were set as described below.

[0278] Atmosphere to be measured: nitrogen

[0279] Measurement mode: Tension mode (AutoTension, AutoStrain control)

[0280] Measurement temperature: -50~200℃

[0281] Heating rate: 5℃ / min

[0282] Frequency: 10Hz

[0283] The following are the evaluation criteria.

[0284] ○: 1.5×10 9 Pa and above

[0285] ×: less than 1.5×10 9 Pa

[0286] [Table 1]

[0287]

[0288] [Table 2]

[0289]

[0290] [Table 3]

[0291]

[0292] It should be noted that the following table contains details of the abbreviations.

[0293] H6XDI: 1,3-bis(isocyanate-methyl)cyclohexane, TAKENATE 600, manufactured by Mitsui Chemicals Co., Ltd.

[0294] HDI: 1,6-Hexanediisocyanate

[0295] PDI: 1,5-Pentanediisocyanate

[0296] IPDI: Isophorone diisocyanate

[0297] IBA: Isobutanol

[0298] 1,3-BG: 1,3-Butanediol

[0299] CAPS: 3-(cyclohexylamino)propanesulfonic acid, an active hydrogen compound containing a sulfonyl group.

[0300] MePEG1000: Methoxylated PEG, a single-terminated polyoxyethylene glycol, an active hydrogen compound containing nonionic groups, with a number average molecular weight of 1000.

[0301] DMCHA: N,N-Dimethylcyclohexylamine

[0302] PMA: Propylene glycol methyl ether acetate

[0303] It should be noted that the above-described invention is provided as an illustrative embodiment of the present invention, but it is merely illustrative and not intended to be limiting. Modifications of the present invention that will be apparent to those skilled in the art are included in the appended claims.

[0304] Industrial availability

[0305] The water-dispersible polyisocyanate, waterborne polyurethane resin composition and articles of the present invention are preferably used, for example, in automotive exterior trim, surface resin coatings for household electrification products, and flexographic printing inks for flexible packaging.

Claims

1. Water-dispersible polyisocyanates, which are water-dispersible polyisocyanates containing isocyanate groups and sulfonates. The water-dispersible polyisocyanate comprises a reaction product of a polyisocyanate component and a hydrophilic active hydrogen component. The polyisocyanate component includes a bis(isocyanate-methyl)cyclohexane derivative. The bis(isocyanate-methyl)cyclohexane derivative is a reaction product obtained by combining a urethane-isocyanurate esterification catalyst with the reaction product of bis(isocyanate-methyl)cyclohexane monomer and alcohol. The isocyanate group of the bis(isocyanate-methyl)cyclohexane monomer has an equivalent ratio of NCO / OH to the hydroxyl group of the alcohol that is greater than 1 and less than 100. The alcohol has 1 to 10 carbon atoms. The proportion of polyisocyanates excluding the bis(isocyanate methyl)cyclohexane derivative, relative to the total amount of the polyisocyanate components, is less than 50% by mass. The hydrophilic active hydrogen component includes an active hydrogen compound containing a sulfonyl group. The sulfonyl group content is 0.2% to 5% by mass relative to the total amount of the water-dispersible polyisocyanate. The bis(isocyanate-methyl)cyclohexane derivative comprises urethane derivatives and isocyanurate derivatives, wherein the proportion of the urethane derivatives is more than 25% by mass and less than 75% by mass relative to the total amount of the urethane derivatives and isocyanurate derivatives. When the water-dispersible polyisocyanate contains oxyethylene units, the proportion of oxyethylene units is less than 5% by mass relative to the total amount of the water-dispersible polyisocyanate.

2. The aqueous dispersion of polyisocyanate according to claim 1, wherein, The alcohols include monohydric alcohols.

3. The water-dispersible polyisocyanate as described in claim 1, wherein, The isocyanate groups of the water-dispersible polyisocyanate were blocked using a capping agent.

4. An aqueous polyurethane resin composition comprising: The water-dispersible polyisocyanate of claim 1; and Compounds containing active hydrogen groups.

5. An article comprising a coating material and a polyurethane layer disposed on the surface of the coating material. The polyurethane layer comprises a cured coating of the aqueous polyurethane resin composition of claim 4.

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