JP2001226444A - Method for producing water-based polyurethane resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for the production of a water-based polyurethane resin having excellent durability such as water-resistance, solvent-resistance and chemical resistance. SOLUTION: The objective water-based polyurethane resin having a carboxylate group and/or sulfonate group content of 0.1-1 mmol/g in the finally produced resin is produced by reacting (a) an organic polyisocyanate with (b) a polyol having a number-average molecular weight of 62-10,000 and subjecting the obtained isocyanate-terminated prepolymer to the chain-extension reaction with (c) an amine compound containing primary and/or secondary amino groups and having a number-average molecular weight of 61-500 in water and/or an organic solvent. The component (b) at least has carboxylate group and/or sulfonate group or an acidic group convertible into carboxylate group and/or sulfonate group by neutralization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an aqueous polyurethane resin. More specifically, mechanical strength,
The present invention relates to a method for producing an aqueous polyurethane resin having excellent physical properties such as durability.

[0002]

2. Description of the Related Art Polyurethane resin has good adhesion to a substrate,
Because of its excellent abrasion resistance, impact resistance and solvent resistance, it is widely used in papers, plastics, films, metals, textiles, etc. as paints, inks, adhesives and various coating agents. As for aqueous conversion, those using an aqueous polyurethane resin such as an emulsion, a colloidal dispersion, and a water-soluble type have been developed.

Since the urea group has a stronger cohesive force than the urethane group, it is widely known that the heat resistance and the like are improved by introducing the urea group into the polyurethane resin. In the case of an aqueous polyurethane resin, a method for introducing a urea group is generally to react an isocyanate group-terminated prepolymer with an amine and / or water. For example, JP-A-1-69619 discloses that in an aqueous and / or organic medium, an isocyanate group-terminated prepolymer and an amine compound having a primary and / or secondary amino group can be used in an aqueous medium.
It has been proposed to react at a molar ratio such that isocyanate groups / amino groups ≦ 1.5. Also, JP-A-7-15
In No. 7526, the isocyanate group-terminated prepolymer having a rosin skeleton and a carboxyl group is neutralized,
A production method has been proposed in which a cross-linking reaction is carried out during or after emulsification in an aqueous medium, or emulsification is carried out after the cross-linking reaction, and a polyfunctional amine is shown as a chain extender used in the cross-linking reaction. Also, JP-A-9-324169 discloses that a sulfonate group-containing isocyanate group-terminated prepolymer is dispersed in water.
A method for producing an aqueous polyurethane resin to be reacted is shown.

However, in the method described in JP-A-1-69619, the amine compound is a mixture of a monoamine compound and a diamine compound, and the average number of functional groups in the entire amine compound is 1 to 1.9. For this reason,
When viewed as a whole polyurethane resin, the molecular structure near the urea group present in the resin does not have a crosslinked structure (excluding the biuret group structure). For this reason, higher strength,
In fields where high performance such as high durability is required, it is still insufficient. Although the biuret group structure is a crosslinked structure, it is easily hydrolyzed or thermally decomposed. Also, Japanese Patent Application Laid-Open
In JP-A-157526, there is no description about the molar ratio of amino groups of isocyanate groups at the time of a cross-linking reaction and there is no description that a monofunctional amine is used, so that it may be difficult to control the molecular weight of the obtained polyurethane resin. JP-A-9-
In the production method described in JP-A-324169, the active hydrogen group component is only water, and water is usually present in a large excess compared to the isocyanate group. Therefore, the isocyanate group of the prepolymer participates in the chain extension reaction. As a result, the number of amino groups increases, which may contribute to deterioration in physical properties due to coloring or hydrolysis over time.

[0005]

As described above, in the prior art, a technique for efficiently producing an aqueous polyurethane resin having high durability has not yet been established, and its appearance has been strongly demanded.

An object of the present invention is to provide a method for producing an aqueous polyurethane resin having excellent durability such as water resistance, solvent resistance and chemical resistance.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a specific isocyanate group-terminated prepolymer and a specific amine compound can be chained in water or an organic medium. The present inventors have found that a production method in which an extension reaction is performed can solve the above-mentioned problems, and have completed the present invention.

That is, the present invention relates to an isocyanate group-terminated prepolymer obtained by reacting (a) an organic polyisocyanate with (b) a polyol having a number average molecular weight of 62 to 10,000; ) Molecular weight 61-50
A chain extension reaction of an amine compound having a primary and / or secondary amino group of 0 with water and / or an organic medium, and the component (b) is a carboxylate group and / or a sulfonate group or It has at least an acidic group that can be converted to a carboxylate group and / or a sulfonate group by summation, and the carboxylate group and / or sulfonate group is contained in the polyurethane resin finally produced in an amount of 0.1 to
In the method for producing an aqueous polyurethane resin containing 1 mmol / g, the component (c) is (c1) a compound having three or more primary and / or secondary amino groups in the same molecule,
And (c2) a mixture containing a compound having one primary or secondary amino group in the same molecule, and the average number of amino functional groups in (c) is 2 ≦ f <5. A method for producing an aqueous polyurethane resin, wherein the molar ratio of the isocyanate group of the prepolymer to the amino group of (c) is 0.5 ≦ isocyanate group / amino group ≦ 2.

Hereinafter, the present invention will be described in detail. First, the raw materials used in the present invention will be described. The (a) organic polyisocyanate used in the present invention includes 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate,
2,2'-diphenylmethane diisocyanate, 1,5
-Naphthylene diisocyanate, 1,4-naphthylene diisocyanate, p-phenylene diisocyanate, m
-Phenylene diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, tetramethyl xylylene diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2, 2'-diphenylpropane-4,4 '
Aromatic diisocyanates such as diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, and tetramethylene diisocyanate , Hexamethylene diisocyanate, 2-methyl-1,5-
Aliphatic diisocyanates such as pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, lysine diisocyanate, isophorone diisocyanate,
Alicyclic diisocyanates such as hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tetramethyl xylylene diisocyanate, cyclohexyl diisocyanate, and mixtures of two or more of these, and urethane modification of these organic diisocyanates Body, allophanate modified, urea modified, biuret modified,
Any known organic polyisocyanate such as a uretdione modified product, a uretoimine modified product, an isocyanurate modified product, a carbodiimide modified product, etc. may be used.

In the present invention, considering the weather resistance of the aqueous polyurethane resin, (a) the organic polyisocyanate
Those containing 50 to 100 mol% of an aliphatic diisocyanate and / or an alicyclic diisocyanate are preferable, and those having 80 to 100 mol% are particularly preferable. Among the above organic polyisocyanates, hexamethylene diisocyanate, isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate are particularly preferred.

The polyol (b) used in the present invention comprises:
It has a number average molecular weight of 62 to 10,000 having at least a carboxylate group and / or a sulfonate group or an acidic group which can be converted into a carboxylate group and / or a sulfonate group by neutralization.

The carboxylate group and / or the sulfonate group have a property that the polyurethane resin has high strength and high durability,
Further, it is a group selected for expressing self-emulsifying properties. On the other hand, when an oxyethylene group, which is a nonionic group, is introduced, the water resistance of the obtained polyurethane resin coating tends to be insufficient. Further, when a quaternary ammonium salt which is a cationic group is introduced, the heat resistance of the obtained polyurethane resin coating tends to be insufficient.

(B) is a (number average) molecular weight of 62 to 500.
Less than a low molecular polyol and a number average molecular weight of 500-10,
000 high molecular polyols.

The low molecular polyol includes ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 5-pentanediol, 1,6-hexanediol, 2-methyl-
1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, decamethylene glycol, diethylene glycol, dipropylene glycol, 2,2- Diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexane Diol, 2-
n-hexadecane-1,2-ethylene glycol, 2-
n-eicosan-1,2-ethylene glycol, 2-n
Octacosan-1,2-ethylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4
Dimethanol, 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2,2-dimethylpropionate, diol dimer acid, bisphenol A, hydrogenated bisphenol A, ethylene oxide or propylene oxide adduct of bisphenol A , Hydrogenated bisphenol A ethylene oxide or propylene oxide adduct, trimethylolpropane, glycerin,
Hexanetriol, quadrol, pentaerythritol, low molecular weight polyols having no cationic group such as sorbitol, 2,2-dimethylolpropionic acid,
-COOH-containing low-molecular-weight polyols such as 2,2-dimethylolbutanoic acid; salts of -COOH-containing low-molecular-weight polyols with ammonia / organic amine / alkali metal / alkaline earth metal; 2-sulfo-1,3- Propanediol,
Mentioned -SO ₃ H-containing low molecular weight polyols such as 2-sulfo-1,4-butanediol, salts with -SO ₃ H containing low molecular polyols with ammonia, organic amines, alkali metal or alkaline earth metal And mixtures of two or more of these.

Examples of the high molecular polyol include polyester polyol, polyamide ester polyol, polycarbonate polyol, polyether polyol, polyether ester polyol, polyolefin polyol, animal and plant polyol, and the like.

Examples of the polyester polyol include known phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, succinic acid, tartaric acid, oxalic acid, malonic acid,
Glutaric acid, adipic acid, pimelic acid, suberic acid, curtaconic acid, azelaic acid, sebacic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, 1,4-cyclohexyldicarboxylic acid, α-hydromuconic acid, β-hydro Muconic acid, α-butyl-α-ethylglutaric acid,
α, β-diethylsuccinic acid, maleic acid, fumaric acid,
Polycarboxylic acids having no cationic group such as trimellitic acid and pyromellitic acid; -SO ₃ H-containing polycarboxylic acids such as 5-sulfo-isophthalic acid;
Salts with organic amines / alkali metals / alkaline earth metals, their anhydrides / halides, dialkyl esters, etc., and at least one of these anhydrides / acid halides, dialkyl esters, etc .; Some are obtained by reaction with polyols. Furthermore, it is obtained by ring-opening polymerization of a cyclic ester (so-called lactone) monomer such as ε-caprolactone, alkyl-substituted ε-caprolactone, δ-valerolactone, and alkyl-substituted δ-valerolactone using the aforementioned low-molecular polyol as an initiator. Lactone-based polyester polyols and the like can be mentioned. Further, a part of the low molecular polyol may be a low molecular polyamine such as hexamethylenediamine, isophoronediamine, monoethanolamine, or a low molecular amino alcohol. In this case, a polyamide ester polyol is obtained.

As the polyether polyol, the above-mentioned low-molecular polyol, low-molecular polyamine or low-molecular amino alcohol is used as an initiator, and alkylene oxides such as ethylene oxide and propylene oxide, epoxides such as tetrahydrofuran and the like, or mixtures of cyclic ethers are used. Those obtained by ring-opening polymerization are exemplified.

Examples of the polycarbonate polyol include those obtained by a dealcoholation reaction or a dephenolization reaction of at least one of the aforementioned low-molecular polyols with ethylene carbonate, diethyl carbonate or diphenyl carbonate.

Examples of the polyetherester polyol include a copolyol obtained from the above-mentioned polyether polyol and the above-mentioned dicarboxylic acid. Further, those obtained by the reaction of the above-mentioned polyester or polycarbonate with an epoxide or a cyclic ether may be mentioned.

Examples of the polyolefin polyol include polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, hydrogenated polyisoprene, and chlorinated products thereof.

Examples of animal and plant polyols include castor oil polyols and silk fibroin.

If the number-average molecular weight is 500 or more and one molecule has an average of one or more active hydrogen groups per molecule, epoxy resin, dimer acid-based polyol and hydrogenated dimer acid-based polyol, Active hydrogen group-containing resins such as polyamide resins, polyester resins, acrylic resins, rosin resins, urea resins, melamine resins, phenol resins, coumarone resins, and polyvinyl alcohol can also be used.

In the present invention, (b) preferably contains a polymer polyol, and preferably contains a polyester polyol or a polycarbonate polyol having good adhesion and durability. When a polymer polyol is not used, the urethane group concentration becomes too high, so that the production of a polyurethane resin tends to be difficult. The preferred number average molecular weight of the high molecular polyol is 500 to 5,
000. The preferred average number of functional groups of the high molecular polyol is 2 to 3.

The (c) amine compound having a primary and / or secondary amino group used in the present invention refers to -N in the molecule.
Those having a H ₂ and / or -NH-, the number average molecular weight is from 61 to 500, preferably from 61 to 300.

Component (c) is (c1) a compound having three or more primary and / or secondary amino groups in the same molecule,
And (c2) a mixture containing a compound having one primary or secondary amino group in the same molecule, and (c) having an average number of amino functional groups (f) of 2 ≦ f <5, preferably 2 ≦ f <5.
f ≦ 4. By using (c1), it is possible to introduce a crosslinked structure into the polyurethane resin and improve the strength and durability. Further, by using (c2), the (number average) molecular weight of the polyurethane resin can be easily controlled. Further, by setting the average number of amino functional groups in (c) to the above range, a polyurethane resin film which is appropriately crosslinked and has excellent durability and the like can be obtained. That is, when the average number of amino functional groups in (c) is too low, the durability and the like of the formed polyurethane resin are liable to decrease, and when the average number of amino functional groups is too high, the polyurethane resin is excessively crosslinked. Therefore, it is difficult to obtain the film itself.

As (c1), diethylenetriamine, triethylenetetramine, tetraethylenepentamine, tris (aminophenyl) methane, triaminobenzene, triaminotoluene, triaminophenol, tris (aminocyclohexyl) methane, triaminocyclohexane, Examples thereof include hydrogenated triaminotoluene, hydrogenated triaminophenol, and compounds in which three or more ethyleneimines are added to a compound having an active hydrogen group. In the present invention, diethylenetriamine and triethylenetetramine are preferred.

Examples of (c2) include aliphatic amines such as ethylamine, butylamine, diethylamine and dibutylamine; aromatic amines such as aniline and N-methylaniline; monoethanolamine, monopropanolamine;
Monoalkanolamines such as diethanolamine and dipropanolamine, and dialkanolamines are exemplified. In the present invention, monoalkanolamines are preferred,
Particularly, monoethanolamine is preferred.

In (c), an amine compound other than (c1) and (c2) can be used. Specifically, ammonia, ethylenediamine, hexamethylenediamine, isophoronediamine, diaminodiphenylmethane,
Examples thereof include diaminodiphenylsulfone, diaminodicyclohexylmethane, and tolylenediamine.

Next, the reaction procedure will be described. First, an isocyanate group-terminated prepolymer is produced by reacting (a) an organic polyisocyanate with (b) a polyol in a molar ratio of an isocyanate group in excess of a hydroxyl group. Considering the control of the subsequent chain extension reaction and the physical properties of the obtained polyurethane resin, the ratio of (a) the organic polyisocyanate and (b) the polyol constituting the isocyanate group-terminated prepolymer is determined by the ratio of the isocyanate group to the hydroxyl group. 1 <isocyanate group / hydroxyl group ≦
A ratio of 2 is preferable, and a ratio of 1.2 ≦ isocyanate group / hydroxyl group ≦ 1.8 is particularly preferable. If there are too many isocyanate groups, a lot of free organic polyisocyanate is present in the prepolymer. The product of the reaction between the free polyisocyanate and the polyamine does not contain a hydrophilic group and thus does not disperse in water, that is, there is a possibility that a precipitate is generated.

The reaction temperature at the time of prepolymerization is 3
0 to 120 ° C, more preferably 50 to 100 ° C.

In the present invention, an aromatic hydrocarbon solvent such as toluene and xylene, an aliphatic hydrocarbon solvent such as pentane, hexane and octane, an alicyclic hydrocarbon solvent such as cyclopentane, cyclohexane and methylcyclohexane,
Acetone, methyl ethyl ketone, methyl butyl ketone,
Ketone solvents such as methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, ether solvents such as diethyl ether, 1,4-dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol dimethyl ether, propylene glycol monomethyl Cellosolve solvents such as ether acetate, ethyl acetate, monobasic ester solvents such as butyl acetate, dimethyl adipate, dimethyl succinate, dibasic acid esters such as dioctyl phthalate, methanol, ethanol, normal propanol,
It is preferable to use an alcoholic organic solvent such as isopropanol, an aprotic polar solvent such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and a mixed solvent thereof before the chain extension reaction. This organic solvent is preferably an organic solvent miscible with water.

The reaction apparatus is not particularly limited as long as the reaction can be performed uniformly, and examples thereof include a mixing and kneading apparatus such as a reaction vessel equipped with a stirrer, a kneader, and a single-screw or multi-screw extrusion reactor. . In the present invention, considering the subsequent chain extension reaction, the reaction device is preferably a reaction vessel equipped with a stirring device.

As a reaction catalyst for synthesizing the isocyanate group-containing prepolymer, a known so-called urethanization catalyst can be used. Specific examples include organic metal compounds such as dibutyltin dilaurate, organic amines such as triethylenediamine, and salts thereof.

The chain extension reaction is performed in water and / or an organic solvent. When the reaction is carried out in water, the amine compound (c) is reacted with the prepolymer simultaneously with or after the prepolymer is dispersed in water. When the reaction is performed in an organic solvent, (c) reacting the amine compound with the prepolymer,
The obtained resin is dispersed in water. In the present invention,
A method in which the chain extension reaction and the dispersion of the prepolymer are performed at the same time, that is, a method in which an amine compound and water are simultaneously charged into the prepolymer (solution) is preferable. When a chain extension reaction is performed in an organic medium, gelation may occur, and subsequent dispersion in water may not be possible. Further, if the chain extension reaction is performed after the aqueous dispersion of the prepolymer, shocking may occur when the amine compound (c) is charged.

The temperature during the chain extension reaction is from 0 to 100.
C is preferable, and more preferably 20 to 80C.

In the chain extension reaction, the ratio of the isocyanate group of the prepolymer to the amino group of (c) is 0.5 ≦
Molar ratio such that isocyanate group / amino group ≦ 2,
Preferably, the molar ratio is such that isocyanate group / amino group = 1. If the number of amino groups is too small, the polyurethane resin may not attain a molecular weight sufficient to exhibit mechanical properties. In addition, the molecular end of the obtained polyurethane resin is often an amino group. this is,
This is because the isocyanate group of the prepolymer reacts with an excessive amount of water to become an amino group after emulsification.
If the amino group contained in the polyurethane resin is too large, it causes coloring and hydrolysis, and the resulting aqueous polyurethane resin tends to have insufficient stability over time.

The obtained resin has carboxylate groups and / or
Alternatively, a sulfonate group will be contained, but the final carboxylate group and / or sulfonate group may be formed before the aqueous dispersion. In the present invention, it is preferable that a carboxylate group and / or a sulfonate group be formed before the chain extension reaction.

Examples of neutralizing agents for neutralizing acidic groups that can be converted into carboxylate groups and / or sulfonate groups include ammonia, ethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine. , N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N-methylmorpholine, 2-
Examples thereof include organic amines such as amino-2-ethyl-1-propanol, alkali metals such as lithium, potassium, and sodium, and inorganic alkalis such as sodium hydroxide and potassium hydroxide, and weather resistance and water resistance after drying. In order to improve the water content, those having high volatility which easily dissociates by heat are preferable, and ammonia, trimethylamine and triethylamine are preferable. The neutralizing agents may be used alone or in a mixture of two or more.

Thereafter, when an organic solvent is used, it is preferable to remove it. The method of removing the organic solvent
Vacuum distillation is preferred. The content of the organic solvent is preferably 1% by mass or less. When the content of the organic solvent is more than 1% by mass, it may have a flash point, and the meaning of making the polyurethane resin aqueous is lost.

The content of the carboxylate group and / or the sulfonate group in the aqueous polyurethane resin thus obtained is 0.1 to 1 mmol / g, preferably 0.1 to 1 mmol / g.
5 to 0.9 mmol / g. When the content of the carboxylate group and / or the sulfonate group is less than the lower limit,
The water dispersibility of the polyurethane resin is insufficient. If it exceeds the upper limit, the water resistance tends to decrease.

The solid content of the aqueous polyurethane resin obtained by the present invention is 1 to 70% by mass, preferably 10 to 70% by mass.
60% by mass. When the solid content is less than the lower limit, a coating film is not easily formed, for example, when used as an aqueous paint.
If the solid content exceeds the upper limit, the viscosity may be too high or thixotropic properties may be exhibited, making it difficult to apply.

The viscosity at 25 ° C. of the aqueous polyurethane resin obtained by the present invention is 50,000 mPa · s or less,
Preferably, it is 40,000 mPa · s or less. If the viscosity exceeds the upper limit, it may be difficult to apply when used as an aqueous paint.

The aqueous polyurethane resin obtained by the present invention has an average particle size of 1 to 1,000 nm, preferably 5 to 1,000 nm.
８００800 nm. If the average particle size is too small, an emulsion may not be formed and the viscosity may increase.
If the average particle size is too large, the particles may settle with time.

In the aqueous polyurethane resin of the present invention, if necessary, additives and auxiliaries commonly used in aqueous systems can be used. For example, pigments, antiblocking agents, dispersion stabilizers, viscosity regulators, leveling agents, antigelling agents, light stabilizers, antioxidants, ultraviolet absorbers, inorganic and organic fillers, plasticizers, lubricants, antistatic agents , A reinforcing material, a catalyst and the like can be added.

The aqueous polyurethane resin of the present invention can be used by blending another resin emulsion. For example,
Acrylic emulsion, polyester emulsion, polyolefin emulsion, latex and the like.

[0046]

The present invention will be described in detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. In addition,
In the following examples, "%" means% by mass unless otherwise specified.

Example 1 A 2 L flask equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer was replaced with dry air, and then 300 g of polyol A was charged and the temperature was adjusted to 50 ° C. did. Next, 128.0 g of H ₁₂ -MDI was added, and DOTD
0.04 g of L was charged and reacted at 80 ° C. for 2 hours.
Next, the mixture was cooled to 50 ° C., and 178 g of acetone, 22.3 g of DMBA, and 15.2 g of TEA were prepared in advance.
The mixed liquid was charged and reacted at 50 ° C. for another 5 hours. Thereafter, 188 g of acetone was charged to obtain an isocyanate group-terminated prepolymer solution. To this prepolymer solution, 91 g of IPA, 862 g of water,
DA was 14.4 g, DETA was 6.4 g, and MEA was 1.
1 g of the blended liquid was charged, and a chain extension reaction and emulsification were performed. Thereafter, acetone and IPA were removed at 50 ° C. × 13.3 kPa until the content became less than 1% to obtain an aqueous polyurethane resin PU-1. PU-1
Has a solid content of 40.2% and a viscosity at 25 ° C. of 63 mPa ·
s, the average particle size was 90 nm.

Example 2 A flask equipped with the same apparatus as in Example 1 was replaced with dry air, and then 300 g of polyol B was charged.
The temperature was adjusted to ° C. Next, 116.2 g of IPDI, D
0.04 g of OTDL was charged and reacted at 80 ° C. for 2 hours. Next, the mixture was cooled to 50 ° C., and 172 g of acetone, 20.1 g of DMPA, and 1
5.2 g of the blended liquid was charged, and at 50 ° C., a further 5
Allowed to react for hours. After that, 193 g of acetone was charged,
An isocyanate group-terminated prepolymer solution was obtained. To this prepolymer solution, 91 g of IPA and 859 of water were previously added.
g, IPDA 30.7 g, DETA 2.3 g, ME
A liquid containing 1.4 g of A was charged, and a chain extension reaction and emulsification were performed. Thereafter, at 50 ° C. × 13.3.
At kPa, the content of acetone and IPA was removed to less than 1% to obtain an aqueous polyurethane resin PU-2.
PU-2 has a solid content of 40.1% and a viscosity of 25 m at 25 ° C.
Pa · s and the average particle size were 95 nm.

Example 3 A flask equipped with the same apparatus as in Example 1 was replaced with dry air, and then 300 g of polyol C and 2 parts of DMBA were added.
2.3 g, 15.2 g of TEA and 168 g of acetone were charged and dissolved at 50 ° C. Next, the TDI is set to 104.
5 g and 0.04 g of DOTDL were charged and reacted at 80 ° C. for 5 hours. Next, the mixture was cooled to 50 ° C., and 179 g of acetone was charged to obtain an isocyanate group-terminated prepolymer solution. IPA is added to this prepolymer solution in advance.
87 g, water 817 g, DETA 19.6 g, ME
A liquid containing 1.8 g of A was charged, and a chain extension reaction and emulsification were performed. Thereafter, at 50 ° C. × 13.3.
At kPa, the content of acetone and IPA was removed until the content became less than 1% to obtain an aqueous polyurethane resin PU-3.
PU-3 has a solid content of 40.0% and a viscosity at 25 ° C of 8.5.
00 mPa · s and the average particle size was 130 nm.

Example 4 A flask equipped with the same apparatus as in Example 1 was replaced with dry air, and then 300 g of polyol D was charged.
The temperature was adjusted to ° C. Next, 73.0 g of IPDI, DO
0.03 g of TDL was charged and reacted at 80 ° C. for 2 hours. Next, the mixture was cooled to 50 ° C., and 148 g of acetone, 8.0 g of DMPA, and 15.2 of TEA were prepared in advance.
g of the mixed solution was charged and reacted at 50 ° C. for another 5 hours. Thereafter, 152 g of acetone was charged to obtain an isocyanate group-terminated prepolymer solution. 75 g of IPA, 709 g of water, T
A liquid containing 8.6 g of ETA and 0.3 g of MEA was charged, and a chain extension reaction and emulsification were performed. Then, at 50 ° C. × 13.3 kPa, acetone and IP
A was removed until the content became less than 1% to obtain an aqueous polyurethane resin PU-4. The solid content of PU-4 is 40.3
%, The viscosity at 25 ° C. was 20,000 mPa · s, and the average particle size was 100 nm.

Example 5 After a flask equipped with the same apparatus as in Example 1 was replaced with dry air, 300 g of polyol E and 7.
8 g was charged and the temperature was adjusted to 50 ° C. Next, 83.0 g of IPDI and 0.04 g of DOTDL were charged and reacted at 80 ° C. for 2 hours. Next, cool down to 50 ° C,
In advance, 154 g of acetone and 11.1 of DMBA were added.
g, 15.2 g of TEA compounded liquid,
The reaction was further performed at 50 ° C. for 5 hours. Then, add 1 acetone
60 g and 667 g of water were charged to emulsify the isocyanate group-terminated prepolymer. Immediately after emulsification, 79 g of IPA, 75 g of water,
A solution containing 2.3 g of DETA, 2.7 g of TETA, and 0.5 g of MEA was charged, and a chain extension reaction and emulsification were performed. Then, 50 ° C x 13.3 kP
In a, acetone and IPA were removed until the content became less than 1% to obtain an aqueous polyurethane resin PU-5. PU
The solid content of −5 is 39.9%, and the viscosity at 25 ° C. is 11,000.
0 mPa · s and the average particle size was 110 nm.

Example 6 A 3 L flask equipped with the same apparatus as in Example 1 was replaced with dry air, 300 g of polyol F was charged, and the temperature was adjusted to 50 ° C. Next, IPDI is
5.5 g and 0.06 g of DOTDL were charged and reacted at 80 ° C. for 2 hours. Next, the mixture was cooled to 50 ° C., and 245 g of acetone, 75.8 g of DMBA,
Charge the liquid containing 30.4 g of TEA, and add 50
The reaction was further performed at 5 ° C. for 5 hours. Then, 282 acetone was added.
g to obtain an isocyanate group-terminated prepolymer solution. To this prepolymer solution, IPA was previously added to 132.
g, water 1250 g, IPDA 33.2 g, DETA
And a solution prepared by mixing 12.1 g of MEA and 2.4 g of MEA were charged, and a chain extension reaction and emulsification were performed. Then, at 50 ° C. × 13.3 kPa, acetone and IPA
Was removed until the content became less than 1% to obtain an aqueous polyurethane resin PU-6. The solid content of PU-6 is 40.1%,
The viscosity at 25 ° C. is 21,000 mPa · s, and the average particle size is 5
It was 0 nm.

Comparative Examples 1 to 3 Water-based polyurethane resins PU-7 to PU-9 were obtained in the same manner as in Example 1 with the amounts shown in Table 2.

[0054]

[Table 1]

[0055]

[Table 2]

In Examples 1 to 5, Comparative Examples 1 to 3, and Tables 1 and 2, H ₁₂ -MDI: hydrogenated diphenylmethane diisocyanate IPDI: isophorone diisocyanate TDI: 2,4-tolylene diisocyanate Polyol A: 1,6-hexane Polyester diol obtained from diol and adipic acid Number average molecular weight = 2,000 Polyol B: Polycarbonate diol obtained from 1,6-hexanediol and diphenyl carbonate Number average molecular weight = 2,000 Polyol C: Poly (oxytetramethylene) diol Number average molecular weight = 2,000 Polyol D: neopentyl glycol / ethylene glycol = 9/1, isophthalic acid / azelaic acid = 5/5
Polyester diol obtained from mixed diol and mixed dicarboxylic acid (each molar ratio) Number average molecular weight = 2,000 Polyol E: Ethylene glycol as initiator
-Diol obtained by opening caprolactone Number average molecular weight = 2,000 Polyol F: polycarbonate diol obtained from 1,6-hexanediol and diphenyl carbonate Number average molecular weight = 1,000 NPG: neopentyl glycol DMBA: 2,2- Methylolbutanoic acid DMPA: 2,2-methylolpropionic acid TEA: triethylamine DOTDL: dioctyltin dilaurate IPDA: isophoronediamine DETA: diethylenetriamine TETA: triethylenetetramine MEA: monoethanolamine IPA: isopropanol

The aqueous polyurethane resins obtained in Examples and Comparative Examples were evaluated as clear coatings. The evaluation method is as follows. Table 3 shows the results. Evaluation sample preparation method Water-based polyurethane resin is 200 μm wet on an aluminum plate
, And allowed to stand at room temperature for 14 days to prepare an evaluation sample.

Water resistance and alkali resistance: JIS K-54
It was measured according to 00. A: No change in the appearance of the coating film was observed. ：: Almost no change in the appearance of the coating film was observed. Δ: A slight change in the appearance of the coating film was observed. X: The change in the appearance of the coating film is very large.

Solvent resistance: The sample was rubbed with absorbent cotton impregnated with xylene, and the scratches and peeling of the coating film were evaluated by the number of times the absorbent cotton was rubbed. The higher the number, the better.

[0060]

[Table 3]

Since the aqueous polyurethane resins of Comparative Examples 1 and 2 did not use an amine having 3 or more functional groups, the durability of the coating film was insufficient. In particular, in Comparative Example 2, since no monofunctional amine was used, the molecular terminal of the resin became an amino group,
It is considered that the durability was further reduced. Comparative Example 3
Is that the isocyanate group is excessive during the chain extension reaction. It is considered that the excess isocyanate group became an amino group without much involvement in the chain elongation reaction due to the reaction with water, so that it did not have a sufficient molecular weight and the durability was lowered. The water-based polyurethane resins of Examples 1 to 5 have sufficient durability and the like because there is no such case.

[0062]

According to the present invention, the amine compound used in the chain extension reaction contains an amine compound having three or more functional groups and a monofunctional amine compound, and has an appropriate average number of amino functional groups. Give the bridge point,
It is possible that the terminal does not become an amino group. In addition, since the molar ratio of the isocyanate group to the amino group at this time is appropriate, the obtained polyurethane resin has a sufficient number average molecular weight. For this reason, the polyurethane resin obtained for the present invention has high durability. The aqueous polyurethane resin obtained by the present invention can be applied to paints, adhesives, inks, coating agents, sealants, various primers, fillers, and the like.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J034 BA08 CA04 CA12 CA13 CA16 CA17 DB03 DF01 DF02 DG01 DH01 DL01 DP12 HA01 HA07 HC12 HC52 HC54 HC63 HC67 HC70 HC71 JA42 QA03 QA05 QA07 QC05 RA07

Claims (1)

[Claims] (1) (a) an organic polyisocyanate and (b)
An isocyanate group-terminated prepolymer obtained by reacting a polyol having a number average molecular weight of 62 to 10,000,
(C) a chain extension reaction of an amine compound having a (number average) molecular weight of 61 to 500 with a primary and / or secondary amino group in water and / or an organic medium, and the component (b)
Has at least a carboxylate group and / or a sulfonate group or an acidic group that can be converted into a carboxylate group and / or a sulfonate group by neutralization, and the carboxylate group and / or the sulfonate group is contained in the finally produced polyurethane resin. Wherein the component (c) comprises (c1) a compound having three or more primary and / or secondary amino groups in the same molecule, and ( c2)
A mixture containing a compound having one primary or secondary amino group in the same molecule, and the average number of amino functional groups in (c) is 2 ≦ f <5; A method for producing an aqueous polyurethane resin, wherein the molar ratio of the group to the amino group of (c) is 0.5 ≦ isocyanate group / amino group ≦ 2.