Aqueous polyurethane resin dispersion

Abstract

The present invention addresses the problem of providing a polyurethane resin aqueous dispersion that has excellent storage stability and washability when being used in a paint gun and that can provide a coating having excellent post-painting appearance, water-resistant adhesiveness, and hot water-resistant adhesiveness.　A polyurethane resin aqueous dispersion (Q) according to the present invention contains: an aqueous medium; and a polyurethane resin (U) having an acidic group and including, as an essential structural monomer, an active hydrogen component (A) and an organic polyisocyanate component (B), and / or a polyurethane resin (U1) obtained by neutralizing the acidic group included in the polyurethane resin (U). The polyurethane resin (U) has a hydroxyl group. The acid value of the polyurethane resin (U) is 5-18 mgKOH / g. The viscosity of the polyurethane resin (U) at 25°C as measured using a rheometer at a shear rate of 0.1 / s is 100-1,000,000 Pa·s.

Description

Technical Field

[0001] The present invention relates to an aqueous dispersion of a polyurethane resin.

Background Art

[0002] Since the film properties obtained by drying an aqueous dispersion of a polyurethane resin are excellent, it is used as a high-functional aqueous dispersion in paints, adhesives, fiber processing agents, paper processing agents, inks, etc. In the future, from the viewpoints of environmental protection, resource saving, and safety, etc., it is considered to be increasingly important. Conventionally, solvent-based urethanes dissolved in organic solvents have been used in these applications, but due to drawbacks such as the toxicity of organic solvents, the risk of fire, and environmental pollution, in recent years, there has been an increasing trend to switch from solvent-based urethanes to aqueous dispersions of polyurethane resins.

[0003] When an aqueous dispersion of a polyurethane resin is used in paint applications, the paint is applied to a substrate by a paint gun or the like. Generally, when a paint containing an aqueous dispersion of a polyurethane resin with strong cohesive force and easy film formation is applied with a paint gun, it may be difficult to wash and remove the paint containing the aqueous dispersion of the polyurethane resin remaining in the paint gun after using the paint gun. In addition, when a paint containing an aqueous dispersion of a polyurethane resin is spray-coated with a paint gun or the like, there is a problem that the uniformity (surface smoothness) of the paint film is low at the time of coating, and the appearance of the paint film deteriorates. The problems of cleanability and appearance after using this paint gun can be improved by using an aqueous dispersion of a low-molecular-weight polyurethane resin obtained by reacting a terminal isocyanate group with a blocking agent as in Patent Document 1. However, the aqueous dispersion of the polyurethane resin in Patent Document 1 has a problem that it thickens when stored for a long time and has poor storage stability.

[0004] In addition, since articles coated with paint may be used outdoors, water-tight adhesion of the film after coating to the substrate is also required. For the aqueous polyurethane resin dispersion, in addition to the cleanability, appearance, and storage stability after using the coating gun as described above, compatibility of water-tight adhesion and heat-resistant water-tight adhesion is also required.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide an aqueous polyurethane resin dispersion capable of obtaining a film excellent in storage stability, cleanability after using a coating gun, appearance, water-tight adhesion, and heat-resistant water-tight adhesion after coating.

Means for Solving the Problems

[0007] As a result of intensive studies, the present inventors have found an aqueous polyurethane resin dispersion capable of solving the above problems. That is, the present invention is an aqueous polyurethane resin dispersion containing a polyurethane resin (U) having an acidic group having an active hydrogen component (A) and an organic polyisocyanate component (B) as essential constituent monomers and / or a polyurethane resin (U1) obtained by neutralizing the acidic group of the polyurethane resin (U) and an aqueous medium, the polyurethane resin (U) has a hydroxyl group, the acid value of the polyurethane resin (U) is 5 to 18 mgKOH / g, and the viscosity of the polyurethane resin (U) at 25°C measured at a shear rate of 0.1 / s using a rheometer is 100 to 1,000,000 Pa·s, which is an aqueous polyurethane resin dispersion (Q).

Effects of the Invention

[0008] The aqueous polyurethane resin dispersion of the present invention is excellent in storage stability and cleanability after using a painting gun, and can obtain a film excellent in appearance, water resistance adhesion, and heat-resistant water resistance adhesion after painting.

Embodiments for Carrying Out the Invention

[0009] The aqueous polyurethane resin dispersion (Q) of the present invention contains a polyurethane resin (U) having an acidic group with an active hydrogen component (A) and an organic polyisocyanate component (B) as essential constituent monomers and / or a polyurethane resin (U1) obtained by neutralizing the acidic group of the polyurethane resin (U), and an aqueous medium. Further, the polyurethane resin (U) has a hydroxyl group. Further, the acid value of the polyurethane resin (U) is 5 to 18 mgKOH / g. Further, the viscosity of the polyurethane resin (U) at 25°C measured at a shear rate of 0.1 / s using a rheometer is 100 to 1,000,000 Pa·s.

[0010] <Polyurethane resin (U)> First, regarding the polyurethane resin (U) having the above properties, the aspects that the polyurethane resin (U) should satisfy and the preferred aspects of the polyurethane resin (U) will be described. In addition, when the aqueous polyurethane resin dispersion (Q) of the present invention does not contain the polyurethane resin (U) but contains the polyurethane resin (U1), the polyurethane resin (U) which is a precursor of the polyurethane resin (U1) only needs to satisfy the aspects that the following polyurethane resin (U) should satisfy (preferably the preferred aspects of the polyurethane resin (U)). In addition, when the aqueous polyurethane resin dispersion (Q) of the present invention contains a polyurethane resin (U) and a polyurethane resin (U1), at least one of the polyurethane resin (U) or the precursor of the polyurethane resin (U1), i.e., the polyurethane resin (U), only needs to satisfy the following embodiments (preferably the preferred embodiments of the polyurethane resin (U)) that the polyurethane resin (U) should meet. It is preferable that both the polyurethane resin (U) and the polyurethane resin (U) which is the precursor of the polyurethane resin (U1) satisfy the following embodiments (preferably the preferred embodiments of the polyurethane resin (U)) that the polyurethane resin (U) should meet. The polyurethane resin (U) may be used alone or in combination of two or more. The polyurethane resin (U1) may also be used alone or in combination of two or more. It is also possible to use at least one kind of polyurethane resin (U) and at least one kind of polyurethane resin (U1) in combination.

[0011] As described above, the polyurethane resin (U) is a resin composed of an active hydrogen component (A) and an organic polyisocyanate component (B) as essential constituent monomers. The following components will be described.

[0012] <Active hydrogen component (A)> The active hydrogen component (A) is a compound containing an active hydrogen-containing group. In the present invention, the active hydrogen-containing group means a group having an active hydrogen atom. The active hydrogen atom means a hydrogen atom bonded to an oxygen atom, a nitrogen atom, a sulfur atom, etc., and rich in reactivity with an isocyanate group. Examples of the group having this active hydrogen atom (active hydrogen-containing group) include a hydroxyl group, a primary amino group, a secondary amino group, and a thiol group. In the present invention, a carboxyl group and a sulfo group are not included in the active hydrogen-containing group.

[0013] Examples of the active hydrogen component (A) include a polymer polyol (A1), a low molecular weight polyol (A2), a compound (A3) having a hydrophilic group and an active hydrogen atom, a chain extender (A4), and a reaction terminator (A5).

[0014] Examples of the high molecular polyol (A1) include high molecular polyols having a number average molecular weight of 300 or more. The number average molecular weight of the high molecular polyol (A1) is preferably 500 or more, and more preferably 500 to 2,000.

[0015] In the present specification, the number average molecular weight (hereinafter sometimes abbreviated as Mn) and the weight average molecular weight (hereinafter sometimes abbreviated as Mw) are measured by gel permeation chromatography (GPC) using polystyrene as a standard. Mw and Mn are measured by the following measurement methods. (Measurement methods of Mw and Mn) A sample (high molecular polyol, polyurethane resin or polyurethane aqueous dispersion) is added to DMF so that the solid content becomes 0.125% by weight, stirred and dissolved at room temperature for 1 hour, filtered through a filter with a pore size of 0.3 μm, and the Mw and Mn of the components contained in the obtained filtrate are measured by GPC using DMF as a solvent and polystyrene as a molecular weight standard. The GPC measurement conditions are as follows. Apparatus: "HLC-8220GPC" [manufactured by Tosoh Corporation] Column: "Guardcolumn α" + "TSKgel α-M" [both manufactured by Tosoh Corporation] Sample solution: 0.125% by weight dimethylformamide solution Eluent: Dimethylformamide Solution injection volume: 100 μl Flow rate: 1 ml / min Measurement temperature: 40°C Detector: Refractive index detector Reference substance: Standard polystyrene (TSKstandard POLYSTYRENE) [manufactured by Tosoh Corporation]

[0016] Examples of the high molecular polyol (A1) include polyether polyols, polyester polyols, and polycarbonate polyols.

[0017] Examples of the polyether polyol include aliphatic polyether polyols and aromatic ring-containing polyether polyols. Note that the polyether polyol does not include the polyester polyol and polycarbonate polyol described below.

[0018] Examples of the aliphatic polyether polyol include adducts of alkylene oxides having 2 to 4 carbon atoms to aliphatic polyhydric alcohols having 2 to 20 carbon atoms (such as ethylene glycol, propylene glycol, butanediol, dodecanediol, and glycerin). Specific examples include polyoxyethylene polyols [such as polyethylene glycol (hereinafter abbreviated as PEG)], polyoxypropylene polyols [such as polypropylene glycol], polyoxyethylene / propylene polyols, and polytetramethylene ether glycols.

[0019] Examples of commercially available aliphatic polyether polyols include PTMG650 [polytetramethylene ether glycol with Mn = 650, manufactured by Mitsubishi Chemical Corporation], PTMG1000 [polytetramethylene ether glycol with Mn = 1,000, manufactured by Mitsubishi Chemical Corporation], PTMG1300 [polytetramethylene ether glycol with Mn = 1,300, manufactured by Mitsubishi Chemical Corporation], PTMG1500 [polytetramethylene ether glycol with Mn = 1,500, manufactured by Mitsubishi Chemical Corporation], PTMG1800 [polytetramethylene ether glycol with Mn = 1,800, manufactured by Mitsubishi Chemical Corporation], PTMG2000 [polytetramethylene ether glycol with Mn = 2,000, manufactured by Mitsubishi Chemical Corporation], PTMG3000 [polytetramethylene ether glycol with Mn = 3,000, manufactured by Mitsubishi Chemical Corporation], PTMG4000 [polytetramethylene ether glycol with Mn = 4,000, manufactured by Mitsubishi Chemical Corporation], PTGL3000 [modified PTMG with Mn = 3,000, manufactured by Hodogaya Chemical Co., Ltd.], and Sannix Diol GP-3000 [polypropylene ether triol with Mn = 3,000, manufactured by Sanyo Chemical Industries, Ltd.]. Among these, from the viewpoints of water resistance adhesion and heat-resistant water adhesion, a combination of polytetramethylene ether glycol with Mn of 300 to 1300 and polytetramethylene ether glycol with Mn of 1500 to 4000 is preferable.

[0020] As a specific production method of the aliphatic polyether polyol, taking polytetramethylene ether glycol (PTMG), which is a polyether polyol, as an example, methods such as production by ring-opening polymerization of tetrahydrofuran (THF), which is a general production method, can be mentioned.

[0021] Examples of the aromatic ring-containing polyether polyol include adducts of alkylene oxides having 2 to 4 carbon atoms to compounds having 6 to 20 carbon atoms (such as bisphenol and resorcinol) having an aromatic ring and two or more hydroxyl groups. Specifically, ethylene oxide (hereinafter abbreviated as EO) adducts of bisphenol A [EO2 mol adduct of bisphenol A, EO4 mol adduct of bisphenol A, EO6 mol adduct of bisphenol A, EO8 mol adduct of bisphenol A, EO10 mol adduct of bisphenol A, EO20 mol adduct of bisphenol A, etc.] and propylene oxide (hereinafter abbreviated as PO) adducts of bisphenol A [PO2 mol adduct of bisphenol A, PO3 mol adduct of bisphenol A, PO5 mol adduct of bisphenol A, etc.] and polyols having a bisphenol skeleton, and EO or PO adducts of resorcinol, etc. can be mentioned. Examples of commercially available products of the aromatic ring-containing polyether polyol include Newpol BPE-20T: [ethylene oxide adduct of bisphenol A with Mn = 321 and hydroxyl value of 349 mgKOH / g, manufactured by Sanyo Chemical Industries, Ltd.] and the like.

[0022] The number average molecular weight of the polyether polyol contained in the active hydrogen component (A) is preferably 500 or more, and more preferably 500 to 2,000.

[0023] Examples of the polyester polyol include a condensation-type polyester polyol, a polylactone polyol, and a castor oil-based polyol. Note that the polyester polyol does not include the polycarbonate polyol described later.

[0024] The condensation-type polyester polyol is a polyester polyol of a low-molecular-weight (Mn less than 300) polyhydric alcohol and a polyvalent carboxylic acid having 2 to 10 carbon atoms or its ester-forming derivative. As the low-molecular-weight polyhydric alcohol, a divalent to octavalent or higher aliphatic polyhydric alcohol having Mn less than 300 and an alkylene oxide (representing EO, PO, 1,2-, 1,3-, 2,3- or 1,4-butylene oxide, etc., hereinafter abbreviated as AO) low-molar addition product of a divalent to octavalent or higher phenol can be used. Among the low-molecular-weight polyhydric alcohols that can be used for the condensation-type polyester polyol, preferred are ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, an EO or PO low-molar addition product of bisphenol A, and a combination thereof.

[0025] Examples of the polyvalent carboxylic acid having 2 to 10 carbon atoms or its ester-forming derivative that can be used for the condensation-type polyester polyol include aliphatic dicarboxylic acids (such as succinic acid, adipic acid, azelaic acid, sebacic acid, fumaric acid, and maleic acid), alicyclic dicarboxylic acids (such as dimer acid), aromatic dicarboxylic acids (such as terephthalic acid, isophthalic acid, and phthalic acid), trivalent or higher polycarboxylic acids (such as trimellitic acid and pyromellitic acid), anhydrides thereof (such as succinic anhydride, maleic anhydride, phthalic anhydride, and trimellitic anhydride), acid halides thereof (such as adipic acid dichloride), low-molecular-weight alkyl esters thereof (such as dimethyl succinate and dimethyl phthalate), and a combination thereof.

[0026] Specific examples of the condensation-type polyester polyol include polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyhexamethylene isophthalate diol, polyneopentyl adipate diol, polyethylene propylene adipate diol, polyethylene butylene adipate diol, polybutylene hexamethylene adipate diol, polydiethylene adipate diol, poly(polytetramethylene ether) adipate diol, poly(3-methylpentylene adipate) diol, polyethylene azelate diol, polyethylene sebacate diol, polybutylene azelate diol, polybutylene sebacate diol, polyneopentyl terephthalate diol, and the like.

[0027] Commercially available products of the condensation-type polyester polyol include Kuraray Polyol P-1010 [poly(3-methylpentylene adipate) diol with Mn = 1,000, manufactured by Kuraray Co., Ltd.], Kuraray Polyol P-2010 [poly(3-methylpentylene adipate) diol with Mn = 2,000, manufactured by Kuraray Co., Ltd.], Kuraray Polyol P-3010 [poly(3-methylpentylene adipate) diol with Mn = 3,000, manufactured by Kuraray Co., Ltd.], Kuraray Polyol P-4010 [poly(3-methylpentylene adipate) diol with Mn = 4,000, manufactured by Kuraray Co., Ltd.], Sun Ester 2610 [polyethylene adipate diol with Mn = 1,000, manufactured by Sanyo Chemical Industries, Ltd.], Sun Ester 4620 [polytetramethylene adipate diol with Mn = 2,000], and Sun Ester 2620 [polyethylene adipate diol with Mn = 2,000, manufactured by Sanyo Chemical Industries, Ltd.], and the like.

[0028] The polylactone polyol is a polyaddition product of lactone to the low molecular weight polyhydric alcohol, and examples of the lactone include lactones having 4 to 12 carbon atoms (such as γ-butyrolactone, γ-valerolactone, and ε-caprolactone). Specific examples of the polylactone polyol include polycaprolactone diol, polyvalerolactone diol, and polycaprolactone triol, and the like.

[0029] Castor oil-based polyols include castor oil and modified castor oil modified with a polyol or AO. The modified castor oil can be produced by transesterification of castor oil and a polyol and / or AO addition. Examples of castor oil-based polyols include castor oil, trimethylolpropane-modified castor oil, pentaerythritol-modified castor oil, and EO (4 to 30 moles) adducts of castor oil.

[0030] Examples of polycarbonate polyols include polycarbonate polyols produced by condensing the above-mentioned low-molecular-weight polyhydric alcohols and low-molecular-weight carbonate compounds (for example, dialkyl carbonates having 1 to 6 carbon atoms in the alkyl group, alkylene carbonates having an alkylene group with 2 to 6 carbon atoms, and diaryl carbonates having an aryl group with 6 to 9 carbon atoms) while carrying out a dealcoholization reaction. Two or more kinds of the low-molecular-weight polyhydric alcohols and alkylene carbonates may be used in combination.

[0031] Specific examples of polycarbonate polyols include polyhexamethylene carbonate diol, polypentamethylene carbonate diol, polytetramethylene carbonate diol, and poly(tetramethylene / hexamethylene) carbonate diol (for example, a diol obtained by condensing 1,4-butanediol and 1,6-hexanediol while carrying out a dealcoholization reaction with a dialkyl carbonate).

[0032] Examples of commercially available polycarbonate polyols include Niporan 980R [polyhexamethylene carbonate diol with Mn = 2,000, manufactured by Nippon Polyurethane Industry Co., Ltd.], Kuraray Polyol C-1090 [poly(3-methyl-5-pentanediol / hexamethylene) carbonate diol with Mn = 1,000, manufactured by Kuraray Co., Ltd.], Kuraray Polyol C-2090 [poly(3-methyl-5-pentanediol / hexamethylene) carbonate diol with Mn = 2,000, manufactured by Kuraray Co., Ltd.], Kuraray Polyol C-3090 [poly(3-methyl-5-pentanediol / hexamethylene) carbonate diol with Mn = 3,000, manufactured by Kuraray Co., Ltd.], Kuraray Polyol C-4090 [poly(3-methyl-5-pentanediol / hexamethylene) carbonate diol with Mn = 4,000, manufactured by Kuraray Co., Ltd.], and T4672 [poly(tetramethylene / hexamethylene) carbonate diol with Mn = 2,000, manufactured by Asahi Kasei Chemicals Corporation], etc.

[0033] From the perspective of adjusting the viscosity of the polyurethane resin (U) to the range to be described in detail later and from the perspectives of water resistance adhesion and heat resistance water adhesion, the active hydrogen component (A) preferably contains polytetramethylene ether glycol, which is a high molecular polyol (A1), as an essential constituent monomer. From the perspective of adjusting the Mn of polytetramethylene ether glycol to the range to be described in detail later for the viscosity of the polyurethane resin (U), the Mn is preferably 500 to 2,000.

[0034] Examples of the low molecular polyol (A2) include low molecular polyols with a number average molecular weight (hereinafter abbreviated as Mn) of less than 300. Note that the Mn of the low molecular polyol is a calculated value from the chemical formula.

[0035] Examples of the low molecular weight polyol (A2) with a number average molecular weight (Mn) of less than 300 include aliphatic dihydric alcohols, aliphatic trihydric alcohols, and aliphatic alcohols with four or more hydroxyl groups. Among the low molecular weight polyols (A2) with an Mn of less than 300, aliphatic dihydric or trihydric alcohols are preferred from the viewpoints of water resistance and heat resistance to yellowing. As the aliphatic dihydric alcohol, ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, and 1,6-hexanediol are particularly preferred. As the aliphatic trihydric alcohol, trimethylolpropane is particularly preferred.

[0036] In the present invention, examples of the hydrophilic group of the compound (A3) having a hydrophilic group and an active hydrogen atom include a carboxyl group, a carboxylate group, a sulfo group, and a sulfonate group. Also, as described above, the active hydrogen atom shall not include hydrogen atoms derived from a carboxyl group and a sulfo group. Examples of the compound (A3) having a hydrophilic group and an active hydrogen atom include compounds having 2 to 10 carbon atoms and a carboxyl group [dialkylolalkanoic acids (such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolheptanoic acid, and 2,2-dimethyloloctanoic acid), tartaric acid, and amino acids (such as glycine, alanine, and valine)], compounds having 2 to 16 carbon atoms and a sulfo group [such as 3-(2,3-dihydroxypropoxy)-1-propanesulfonic acid and bis(ethylene glycol) sulfophthalate], and compounds having 2 to 10 carbon atoms and a sulfamic acid group [such as N,N-bis(2-hydroxyethyl)sulfamic acid]. Among these, compounds having a carboxyl group or a carboxylate group are preferred, and 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid are more preferred.

[0037] The active hydrogen component (A) preferably contains, as an essential constituent monomer, a compound (A31) having an acidic group (such as a carboxyl group) among compounds (A3) having a hydrophilic group and an active hydrogen atom. By using the compound (A31), an acidic group can be introduced into the polyurethane resin (U). The above-mentioned compound (A31) is used in an amount capable of bringing the acid value of the polyurethane resin (U) within a range to be described in detail later.

[0038] Examples of the chain extender (A4) include compounds having two or more active hydrogen atoms other than (A1) to (A3). Specifically, water, diamines having 2 to 10 carbon atoms (such as ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, toluenediamine, and piperazine), polyalkylene polyamines having 2 to 10 carbon atoms (such as diethylenetriamine and triethylenetetramine), hydrazine or its derivatives (dibasic acid dihydrazides, such as adipic acid dihydrazide), and amino alcohols having 2 to 10 carbon atoms (such as ethanolamine, diethanolamine, 2-amino-2-methylpropanol, and triethanolamine) etc. can be mentioned.

[0039] Examples of the reaction terminator (A5) include monoalcohols having 1 to 8 carbon atoms (such as methanol, ethanol, isopropanol, cellosolves, and carbitols), and monoamines having 1 to 10 carbon atoms (mono- or dialkylamines such as monomethylamine, monoethylamine, monobutylamine, dibutylamine, and monooctylamine; mono- or dialkanolamines such as monoethanolamine, diethanolamine, propanolamine, and diisopropanolamine) etc. can be mentioned. Specifically, 2-aminoethanol, 2,2'-iminodiethanol, 1-amino-2-propanol, 3-amino-1-propanol, etc. can be mentioned. From the viewpoints of water resistance adhesion and heat-resistant water adhesion, it is preferable that the active hydrogen component (A) contains a reaction terminator (A5).

[0040] The chain extender (A4) and the reaction terminator (A5) affect the urea group content described later and also affect the viscosity of the polyurethane resin (U). Therefore, it is necessary to use them in an amount within a range that does not impair the effects of the present invention. Specifically, it is necessary to use them in an amount within a range in which the viscosity of the polyurethane resin (U) becomes the value described in detail later. Therefore, it is preferable to use the chain extender (A4) and the reaction terminator (A5) in an amount such that the urea group content in the polyurethane resin (U) becomes the value described later.

[0041] The active hydrogen component (A) may be used alone or in combination of two or more.

[0042] <Organic polyisocyanate component (B)> The organic polyisocyanate component (B), which is an essential monomer of the polyurethane resin (U), is a compound having two to three or more isocyanate groups, and those conventionally used in the production of polyurethane resins can be used. Examples of the organic polyisocyanate component (B) include aliphatic polyisocyanates (b1) having 4 to 22 carbon atoms, alicyclic polyisocyanates (b2) having 8 to 18 carbon atoms, araliphatic polyisocyanates (b3) having 10 to 17 carbon atoms, aromatic polyisocyanates (b4) having 8 to 22 carbon atoms, and derivatives of (b1) to (b4) (for example, isocyanurated products).

[0043] Examples of the aliphatic polyisocyanate (b1) having 4 to 22 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate, and the like.

[0044] Examples of the alicyclic polyisocyanate (b2) having 8 to 18 carbon atoms include isophorone diisocyanate (IPDI), dicyclohexylmethane 4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, 2,5- or 2,6-norbornane diisocyanate, and the like.

[0045] Examples of the araliphatic polyisocyanate (b3) having 10 to 17 carbon atoms include m- and / or p-xylylene diisocyanate (XDI), α,α,α',α'-tetramethylxylylene diisocyanate (TMXDI), and the like.

[0046] Examples of the aromatic polyisocyanate (b4) having 8 to 22 carbon atoms include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4'- or 2,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate, 4,4',4''-triphenylmethane triisocyanate, m- or p-isocyanatophenylsulfonyl isocyanate, crude MDI, and the like.

[0047] Among the organic polyisocyanate component (B), (b1) and (b2) are preferred from the viewpoints of the mechanical properties and weather resistance of the resulting film, (b2) is more preferred, and IPDI and hydrogenated MDI are particularly preferred. The organic polyisocyanate component (B) may be used alone or in combination of two or more. Among them, it is preferable that the organic polyisocyanate component (B) contains a linear aliphatic polyisocyanate (b1) having 4 to 22 carbon atoms and / or an alicyclic polyisocyanate (b2) having 8 to 18 carbon atoms.

[0048] The type of the organic polyisocyanate component (B) affects the urethane group content described later and also affects the viscosity of the polyurethane resin (U) to be described in detail later. Therefore, it is necessary to use it within a range that does not impair the effects of the present invention. Specifically, it is necessary to use it within a range where the viscosity of the polyurethane resin (U) becomes the value described later. Therefore, as the type of the organic polyisocyanate component (B), it is preferable to use an amount such that the urethane group content in the polyurethane resin (U) becomes the value described later.

[0049] Note that the polyurethane resin (U) may have a constituent monomer other than the active hydrogen component (A) and the organic polyisocyanate component (B). Examples of the constituent monomer other than the active hydrogen component (A) and the organic polyisocyanate component (B) include polyepoxy compounds having 2 to 30 carbon atoms (such as 1,6-hexanediol diglycidyl ether and trimethylolpropane polyglycidyl ether).

[0050] Regarding the polyurethane resin (U), the viscosity of the polyurethane resin (U) at 25°C measured at a shear rate of 0.1 / s using a rheometer is 100 to 1,000,000 Pa·s. Also, the viscosity of the polyurethane resin (U) at 25°C measured at a shear rate of 0.1 / s using a rheometer is preferably 100 to 150,000 Pa·s from the viewpoints of cleanability and appearance after using a coating gun. Further, from the viewpoints of water-tight adhesion and heat-resistant water-tight adhesion, it is more preferably 3,500 to 13,000 Pa·s, still more preferably 3,500 to 9,000 Pa·s, and particularly preferably 3,500 to 4,500 Pa·s. The viscosity measured using a rheometer can be measured under the following conditions, for example, using "MCR-302" manufactured by Anton Paar. (Measurement conditions) Measurement jig: Parallel plate "PP-08" (diameter 8 mm) Distance between plates: 0.5 mm Measurement temperature: 25°C Measurement mode: Rotation Shear rate: 0.1 / second

[0051] In order to make the viscosity of the polyurethane resin (U) within the above range, as described above, as the active hydrogen component (A), polytetramethylene ether glycol which is a polymer polyol (A1) is used, the urethane group content and the urea group content are set to the preferable values described later, and for the active hydrogen component (A) and the organic polyisocyanate component (B) constituting the polyurethane resin (U), the equivalent ratio of isocyanate group / active hydrogen atom is set to the preferable value (0.6 to 0.95) described later, the molecular weight of the polyurethane resin (U) is set to the preferable value described later, and methods such as setting the acid value to the value described later can be mentioned. For example, when the viscosity of the polyurethane resin (U) is low, by increasing the equivalent ratio of isocyanate group / active hydrogen atom within the preferable range described later, the molecular weight of the polyurethane resin (U) can be increased and the viscosity of the polyurethane resin (U) can be raised. Also, by increasing the urethane group content, the urea group content, and the acid value within the range of the values described later, the viscosity of the polyurethane resin (U) can be raised. Also, for example, when the viscosity of the polyurethane resin (U) is high, by decreasing the equivalent ratio of isocyanate group / active hydrogen atom within the preferable range described later, the molecular weight of the polyurethane resin (U) can be decreased and the viscosity of the polyurethane resin (U) can be reduced. Also, by decreasing the urethane group content, the urea group content, and the acid value within the range of the values described later, the viscosity of the polyurethane resin (U) can be reduced.

[0052] As a method for obtaining the polyurethane resin (U) [including the polyurethane resin (U) which is a precursor of the polyurethane resin (U1)] for measuring the viscosity from the polyurethane resin aqueous dispersion (Q), the following methods etc. can be mentioned. When the component other than the polyurethane resin (U) contained in the polyurethane resin aqueous dispersion (Q) [including the neutralizing agent for the polyurethane resin (U) described later] is a volatile component, the component other than the polyurethane resin (U) can be volatilized by heating etc., and the polyurethane resin (U) can be obtained. In addition, when the aqueous polyurethane resin dispersion (Q) contains a non-volatile component, the polyurethane resin (U) is purified by known chromatography using a volatile solvent as the mobile phase, and then the volatile solvent and the like are removed by heating or the like to obtain the polyurethane resin (U). Also, when the neutralizing agent of the polyurethane resin (U) described later is non-volatile, after performing a salt exchange reaction with a volatile base, components other than the polyurethane resin (U) are removed by the above method to obtain the polyurethane resin (U).

[0053] The urethane group content of the polyurethane resin (U) is preferably 1.0 to 3.5 mmol / g, more preferably 1.0 to 1.5 mmol / g, still more preferably 1.0 to 1.2 mmol / g, and particularly preferably 1.1 to 1.2 mmol / g based on the weight of the polyurethane resin (U) from the viewpoint of adjusting the viscosity of the polyurethane resin (U) to the above-mentioned viscosity. The urea group content of the polyurethane resin (U) is preferably 0.8 mmol / g or less based on the weight of the polyurethane resin (U) from the viewpoint of adjusting the viscosity of the polyurethane resin (U) to the above-mentioned viscosity. Further, from the viewpoints of water resistance adhesion and heat-resistant water resistance adhesion, the urea group content is preferably 0.05 mmol / g or more, and more preferably 0.5 mmol / g or more based on the weight of the polyurethane resin (U). In addition, the ratio of the urea group content to the urethane group content [urea group content / urethane group content] is preferably 0.45 or more, and more preferably 0.47 to 0.80 from the viewpoints of water resistance adhesion and heat-resistant water resistance adhesion. The ratio of the contents of the urea group and the urethane group is 1 quantifiable by 1H-NMR.

[0054] To make the urethane group content of the polyurethane resin (U) within a desired range, the amounts of the active hydrogen component (A) and the organic polyisocyanate component (B) may be appropriately adjusted. The urethane group content can be calculated from the N atom content quantified by a nitrogen analyzer, the ratio of the urea group and urethane group contents, and the allophanate group and biuret group contents. First, by subtracting the amount of N atoms derived from the "allophanate group" and "biuret group" from the "N atom content", the total amount of N atoms derived from the "urethane group" and "urea group" is calculated. Next, from the ratio of the urethane group and urea group, the amounts of N atoms derived from the "urethane group" and "urea group" are calculated respectively. From this value, the urethane group concentration is calculated.

[0055] In order to make the urea group content in the polyurethane resin (U) within a desired range, the amino group content, water content, and isocyanate group content in the raw materials of the polyurethane resin (U) may be appropriately adjusted. The urethane group content can be calculated from the N atom content quantified by a nitrogen analyzer, the ratio of the urea group and urethane group contents, and the allophanate group and biuret group contents. First, by subtracting the amount of N atoms derived from the "allophanate group" and "biuret group" from the "N atom content", the total amount of N atoms derived from the "urethane group" and "urea group" is calculated. Next, from the ratio of the urethane group and urea group, the amounts of N atoms derived from the "urethane group" and "urea group" are calculated respectively. From this value, the urethane group concentration is calculated.

[0056] In the present invention, the total value of the allophanate group and biuret group contents in the polyurethane resin (U) is preferably 0.1 mmol / g or less, more preferably 0.03 mmol / g or less, particularly preferably 0.01 mmol / g or less, especially preferably 0.003 mmol / g or less, and most preferably 0.001 mmol / g or less, based on the weight of the polyurethane resin (U), from the viewpoints of film-forming properties and water resistance of the resulting film.

[0057] In order to make the total value of the contents of allophanate groups and burette groups in the polyurethane resin (U) fall within a desired range, the amino group content in the raw materials of the polyurethane resin (U), the ratio of the equivalent of isocyanate groups to the equivalents of hydroxyl groups and amino groups, the urethanization reaction temperature, etc. may be appropriately adjusted. In particular, regarding the reaction temperature, by setting it to 120°C or lower or 180°C or higher, the formation of allophanate groups and burette groups can be suppressed. The contents of allophanate groups and burette groups are measured by gas chromatography.

[0058] From the viewpoint of adjusting the viscosity of the polyurethane resin (U) to the above-mentioned viscosity, the Mn of the polyurethane resin (U) is preferably 1,500 to 8,000, more preferably 2,000 to 7,500, particularly preferably 2,000 to 6,000, especially preferably 2,000 to 5,500, and most preferably 2,000 to 5,000. By appropriately adjusting the amounts of the active hydrogen component (A) and the organic polyisocyanate component (B), the Mn of the polyurethane resin (U) can be made to fall within a desired range.

[0059] From the viewpoint of adjusting the viscosity of (U) to the above-mentioned viscosity, the Mw of the polyurethane resin (U) is preferably 4,000 to 20,000, more preferably 5,000 to 18,000, still more preferably 6,500 to 15,000, particularly preferably 7,000 to 9,800, and most preferably 7,000 to 7,600.

[0060] Mn and Mw are values measured by the aforementioned gel permeation chromatography (GPC). In GPC measurement, when the solubility of the polyurethane resin (U) in the solvent used for measurement is less than 90% by weight [when dissolving in DMF so as to obtain a solid content concentration of 0.125% by weight, the actually dissolved sample is less than 0.1125% by weight (=0.125×0.90)], the measurement accuracy of GPC decreases. In that case, since it is difficult to accurately measure the molecular weight, the molecular weight of the polyurethane resin is defined as infinite.

[0061] The polyurethane resin (U) has a hydroxyl group as described above. From the viewpoints of paint gun cleanability and appearance, the hydroxyl value of the polyurethane resin (U) is preferably 15 to 100 mgKOH / g. Examples of the hydroxyl group of the polyurethane resin (U) include a hydroxyl group derived from the active hydrogen component (A). By adjusting the amounts of the active hydrogen component (A) and the organic polyisocyanate component (B), the hydroxyl value can be adjusted to the above-preferred range. The hydroxyl value of the polyurethane resin (U) is a value measured according to JIS K0070 (1992).

[0062] The polyurethane resin (U) has an acidic group as described above. From the viewpoint of water resistance adhesion, the acid value of the polyurethane resin (U) is 5 to 18 mgKOH / g, preferably 5 to 15 mgKOH / g, and more preferably 5 to 10 mgKOH / g. Examples of the acidic group of the polyurethane resin (U) include an acidic group derived from a compound (A31) having an acidic group, and examples thereof include a carboxyl group and a sulfo group. By adjusting the amount of the compound (A31) having an acidic group, etc., the acid value can be adjusted to the above-preferred range. The acid value of the polyurethane resin (U) is a value measured according to JIS K0070 (1992).

[0063] From the viewpoint of paint gun cleanability, the weight ratio of the insoluble component generated when the polyurethane resin (U) and acetone (acetone at 25°C, etc.) 10 times its weight are stirred at 80°C for 180 minutes under sealing is preferably 5% by weight or less based on the weight of the added polyurethane resin (U). As a method for measuring the weight ratio of the insoluble component, the following method can be used. (Method for Measuring the Weight Ratio of the Insoluble Component) Charge the polyurethane resin (U) of Wg into a pressure-resistant sealed container with an inner diameter of 6 cm and a depth of 12 cm together with a stirrer chip with a length of 3 cm, add acetone (acetone at 25°C, etc.) with a weight 10 times that of the polyurethane resin (U) (10 g when Wg is 1 g), and stir and mix at 80°C for 180 minutes under sealing to obtain a mixed solution. After filtering the obtained mixed solution with a SUS mesh (mesh opening 75 μm) whose weight (W1) has been measured in advance, wash the filter residue with acetone (acetone at 25°C, etc., the same weight as the acetone charged into the pressure-resistant sealed container). After drying the filter residue and the SUS mesh at 105°C for 30 minutes, measure the total weight (W2). The weight ratio of the insoluble component is calculated by the following formula. Weight ratio of insoluble component (%) = {(W2 - W1) / W} × 100 As a method for obtaining the polyurethane resin (U) for measuring the weight ratio of the insoluble component from the polyurethane resin aqueous dispersion (Q), the above-mentioned "method for obtaining the polyurethane resin (U) for measuring viscosity from the polyurethane resin aqueous dispersion (Q)" etc. can be used.

[0064] In order to make the weight ratio of the insoluble component the above-mentioned preferred value, as the active hydrogen component (A), polytetramethylene ether glycol which is a polymer polyol (A1) is used, the urethane group content and the urea group content are the above-mentioned preferred values, and for the active hydrogen component (A) and the organic polyisocyanate component (B) constituting the polyurethane resin (U), the equivalent ratio of isocyanate group / active hydrogen atom is the following preferred value (0.6 - 0.95), the molecular weight of the urethane resin (U) is the above-mentioned preferred value, and the acid value is the above-mentioned value. Methods etc. can be mentioned. For example, when the weight ratio of the insoluble component of the polyurethane resin (U) is high, by reducing the equivalent ratio of isocyanate group / active hydrogen atom within the following preferred range, the molecular weight of the polyurethane resin (U) can be lowered and the weight ratio of the insoluble component can be reduced. Also, by lowering the urethane group content, the urea group content, and the acid value within the above-mentioned value range, the weight ratio of the insoluble component can be reduced.

[0065] <Polyurethane resin (U1)> The polyurethane resin (U1) in the present invention is a polyurethane resin obtained by neutralizing the acidic groups of the polyurethane resin (U). Here, the acidic groups of the polyurethane resin (U) are preferably acidic groups derived from the compound (A31) having acidic groups (such as carboxyl groups).

[0066] Examples of the neutralizing agent used for neutralizing the acidic groups derived from the compound (A31) include ammonia, amine compounds having 1 to 20 carbon atoms, and hydroxides of alkali metals (such as sodium, potassium, and lithium).

[0067] Examples of the amine compounds having 1 to 20 carbon atoms include primary amines (such as monomethylamine, monoethylamine, monobutylamine, monoethanolamine, and 2-amino-2-methyl-1-propanol), secondary amines (such as dimethylamine, diethylamine, dibutylamine, diethanolamine, and N-methyldiethanolamine), and tertiary amines (such as trimethylamine, triethylamine, dimethylethylamine, N,N-dimethylaminoethanol, and triethanolamine).

[0068] Among these, from the viewpoints of the odor of the aqueous dispersion and the water resistance of the resulting film, preferred are amine compounds having a low vapor pressure at 25°C, and more preferred are triethylamine, monoethanolamine, diethanolamine, N-methyldiethanolamine, and N,N-dimethylaminoethanol.

[0069] <Aqueous dispersion of polyurethane resin (Q)> The aqueous dispersion (Q) of the polyurethane resin (U) in the present invention can be produced by dispersing the polyurethane resin (U) and / or the polyurethane resin (U1) in water.

[0070] The aqueous dispersion (Q) of the polyurethane resin of the present invention can contain additives such as antioxidants, anti-coloring agents, weather stabilizers, plasticizers, and mold release agents together with the polyurethane resin (U) and / or the polyurethane resin (U1). The amount of these additives used is preferably 10% by weight or less, more preferably 3% by weight or less, and particularly preferably 1% by weight or less based on the total weight of the polyurethane resin (U) and the polyurethane resin (U1).

[0071] The aqueous dispersion (Q) of the polyurethane resin of the present invention can be produced while producing the polyurethane resin (U) and / or the polyurethane resin (U1) by the following methods (1), (2), (3), or (4). (1) A method in which the active hydrogen component (A) and the organic polyisocyanate component (B) are mixed together, and after the urethanization reaction, the above-mentioned neutralizing agent is mixed if necessary and dispersed in an aqueous medium. (2) A method in which the active hydrogen component (A) and the organic polyisocyanate component (B) are mixed together, the mixture is dispersed in water, and then the urethanization reaction is carried out, and the above-mentioned neutralizing agent is mixed if necessary. (3) A method in which a urethane prepolymer (P) having an isocyanate group at the terminal obtained by reacting the active hydrogen component (A) [(A1) to (A3), etc.] and the organic polyisocyanate component (B) is mixed with the above-mentioned neutralizing agent at a predetermined weight ratio, dispersed in water, and then (P) is subjected to an extension reaction with a chain extender (A4), and if necessary, a termination reaction is carried out with a reaction terminator (A5). (4) A urethane prepolymer (P) having an isocyanate group at the terminal obtained by reacting the active hydrogen component (A) [(A1) to (A3), etc.] and the organic polyisocyanate component (B) is produced. Then, if necessary, an extension reaction is carried out with a chain extender (A4), and then a termination reaction is carried out with a reaction terminator (A5). Next, if necessary, the above-mentioned neutralizing agent is mixed at a predetermined weight ratio and dispersed in an aqueous medium. Examples of the aqueous medium include water (such as pure water) and a mixture of water and an organic solvent described below.

[0072] From the perspective of the dispersibility of the polyurethane resin (U) and the polyurethane resin (U1) in water, it is preferable that the active hydrogen component (A) contains a compound (A3) having a hydrophilic group and an active hydrogen atom. From the perspectives of the dispersibility of the polyurethane resin (U) and the polyurethane resin (U1) and the stability of the aqueous dispersion in the polyurethane resin aqueous dispersion (Q) of the present invention, if necessary, the urethane prepolymer (P) and the polyurethane resin (U) and / or the polyurethane resin (U1) may be dispersed in water in the presence of a dispersant (g).

[0073] Examples of the dispersant (g) include nonionic surfactants (g1), anionic surfactants (g2), cationic surfactants (g3), amphoteric surfactants (g4), and other emulsifying dispersants (g5). The dispersant (g) may be used alone or in combination of two or more.

[0074] Examples of the nonionic surfactant (g1) include AO addition type nonionic surfactants and polyhydric alcohol type nonionic surfactants. Examples of the AO addition type include EO adducts of aliphatic alcohols having 10 to 20 carbon atoms, EO adducts of phenol, EO adducts of nonylphenol, EO adducts of alkylamines having 8 to 22 carbon atoms, and EO adducts of polypropylene glycol. Examples of the polyhydric alcohol type include fatty acid (8 to 24 carbon atoms) esters of polyhydric (3 to 8 valent or more) alcohols (2 to 30 carbon atoms) (such as glycerin monostearate, glycerin monooleate, sorbitan monolaurate, and sorbitan monooleate), and alkyl (4 to 24 carbon atoms) poly (degree of polymerization 1 to 10) glycosides.

[0075] Examples of the anionic surfactant (g2) include ether carboxylic acids or their salts having a hydrocarbon group with 8 to 24 carbon atoms [sodium lauryl ether acetate and sodium (poly)oxyethylene (1 to 100 moles added) lauryl ether acetate, etc.]; sulfate esters or ether sulfate esters having a hydrocarbon group with 8 to 24 carbon atoms and their salts [sodium lauryl sulfate, sodium (poly)oxyethylene (1 to 100 moles added) lauryl sulfate, triethanolamine (poly)oxyethylene (1 to 100 moles added) lauryl sulfate, and sodium (poly)oxyethylene (1 to 100 moles added) coconut oil fatty acid monoethanolamine sulfate, etc.]; sulfonates having a hydrocarbon group with 8 to 24 carbon atoms [sodium dodecylbenzenesulfonate, etc.]; sulfosuccinates having one or two hydrocarbon groups with 8 to 24 carbon atoms; phosphate esters or ether phosphate esters having a hydrocarbon group with 8 to 24 carbon atoms and their salts [sodium lauryl phosphate and sodium (poly)oxyethylene (1 to 100 moles added) lauryl ether phosphate, etc.]; fatty acid salts having a hydrocarbon group with 8 to 24 carbon atoms [sodium laurate and triethanolamine laurate, etc.]; and acylated amino acid salts having a hydrocarbon group with 8 to 24 carbon atoms [sodium coconut oil fatty acid methyl taurine, sodium coconut oil fatty acid sarcosine, triethanolamine coconut oil fatty acid sarcosine, triethanolamine N-coconut oil fatty acid acyl-L-glutamate, sodium N-coconut oil fatty acid acyl-L-glutamate, and sodium lauroylmethyl-β-alanine, etc.].

[0076] Examples of the cationic surfactant (g3) include quaternary ammonium salt types [stearyltrimethylammonium chloride, behenyltrimethylammonium chloride, distearyldimethylammonium chloride, and ethyl sulfate lanolin fatty acid aminopropyl ethyldimethylammonium, etc.] and amine salt types [dihydrochloride diethylaminoethylamide stearate, dilaurylamine hydrochloride, and oleylamine lactate, etc.].

[0077] Examples of the amphoteric surfactant (g4) include betaine-type amphoteric surfactants [such as coconut oil fatty acid amide propyl dimethylaminoacetic acid betaine, lauryl dimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, lauryl hydroxysulfobetaine, and sodium lauroyl amide ethyl hydroxyethyl carboxymethyl betaine hydroxypropyl phosphate, etc.] and amino acid-type amphoteric surfactants [such as sodium β-lauryl aminopropionate, etc.].

[0078] Examples of other emulsifying and dispersing agents (g5) include cellulose derivatives such as polyvinyl alcohol, starch and its derivatives, carboxymethyl cellulose, methyl cellulose, and hydroxyethyl cellulose, carboxyl group-containing (co)polymers such as sodium polyacrylate, and emulsifying and dispersing agents having a urethane group or an ester group described in U.S. Patent No. 5,906,704 [such as those obtained by linking polycaprolactone polyol and polyether diol with polyisocyanate].

[0079] The dispersing agent (g) may be added at any time before, during, or after the urethanization reaction of the polyurethane resin (U), or before, during, or after the aqueous dispersion step of the polyurethane resin (U). However, from the viewpoints of the dispersibility of the polyurethane resin (U) and the stability of the aqueous dispersion, it is preferably added before or during the aqueous dispersion step.

[0080] The content of the dispersing agent (g) is preferably 0.01 to 20% by weight, more preferably 0.01 to 10% by weight, and particularly preferably 0.1 to 5% by weight based on the total weight of the polyurethane resin (U) and the polyurethane resin (U1). Also, the total weight of the structural unit derived from the compound (A3) and the dispersing agent (g) in the polyurethane resin (U) and the polyurethane resin (U1) is preferably 0.01 to 20% by weight, more preferably 0.1 to 15% by weight, and particularly preferably 0.6 to 10% by weight based on the total weight of the polyurethane resin (U) and the polyurethane resin (U1).

[0081] The aqueous dispersion (Q) of the polyurethane resin in the present invention may contain an organic solvent [such as a ketone solvent (e.g., acetone and methyl ethyl ketone), an ester solvent (e.g., ethyl acetate), an ether solvent (e.g., tetrahydrofuran), an amide solvent (e.g., N,N-dimethylformamide and N-methylpyrrolidone), an alcohol solvent (e.g., isopropyl alcohol), and an aromatic hydrocarbon solvent (e.g., toluene), etc.].

[0082] In the present invention, the polyurethane resin (U) and the urethane prepolymer (P) are obtained by heating and reacting an active hydrogen component (A) and an organic polyisocyanate component (B) in equipment capable of heating. For example, a method of charging the raw materials of the polyurethane resin (U) or the urethane prepolymer (P) into a container, uniformly stirring, and then heating without stirring in a heat dryer or a heating furnace, or a method of heating and reacting with stirring or kneading using a simple pressure reaction apparatus (autoclave), a Kolben, a single-screw or twin-screw kneader, a plastomill, or a universal kneader, etc. Among them, the method of heating and reacting with stirring or kneading is preferable because the homogeneity of the obtained polyurethane resin (U) is increased, and the mechanical properties, durability, chemical resistance, and abrasion resistance of the obtained film tend to be more excellent.

[0083] The polyurethane resin (U) is preferably reacted at a ratio such that the equivalent ratio of the isocyanate group to the active hydrogen atom is 0.6 to 0.95. Further, when producing the polyurethane resin (U) by reacting the active hydrogen component (A) and the organic polyisocyanate component (B), from the viewpoint of adjusting the urea group content to the above-preferred value, the weight ratio of water in the reaction system is preferably 1.45% by weight or less based on the weight of the polyurethane resin (U).

[0084] When producing the polyurethane resin (U) and the urethane prepolymer (P), the reaction temperature is preferably 60 to 120 °C or 180 to 250 °C, more preferably 60 to 110 °C or 180 to 240 °C, and most preferably 60 to 100 °C or 180 to 230 °C, from the viewpoint of the contents of the allophanate group and the biuret group in the polyurethane resin (U). In addition, the time for producing the polyurethane resin (U) and the urethane prepolymer (P) can be appropriately selected depending on the equipment used, but it is preferably 1 minute to 100 hours, more preferably 3 minutes to 30 hours, and particularly preferably 5 minutes to 20 hours. Within this range, a polyurethane resin (U) that can fully exhibit the effects of the present invention can be obtained.

[0085] In order to control the urethanization reaction rate, known reaction catalysts (such as tin octylate and bismuth octylate) and reaction retardants (such as phosphoric acid) can be used. The addition amount of these catalysts or reaction retardants is preferably 0.001 to 3% by weight, more preferably 0.005 to 2% by weight, and particularly preferably 0.01 to 1% by weight based on the weight of the polyurethane resin (U).

[0086] As a device for dispersing the polyurethane resin (U) or the urethane prepolymer (P) in water, any device with dispersion ability can be used. However, from the viewpoints of temperature adjustment, supply of granular or block resin, and dispersion ability, etc., it is preferable to use a rotary dispersion mixer, an ultrasonic disperser, or a kneader, and among them, a rotary dispersion mixer with particularly excellent dispersion ability is more preferable.

[0087] The main dispersion principle of the rotary dispersion mixer is to apply a shearing force from the outside to the material to be processed by the rotation of the driving part, etc. to make it into fine particles and disperse it. In addition, the rotary dispersion mixer can be operated under normal pressure, reduced pressure, or increased pressure.

[0088] Examples of the rotary dispersion mixer include mixers having common stirring blades such as Max Blend and helical blades, TK Homomixer [manufactured by Primix Corporation], Clear Mix [manufactured by M Technique Co., Ltd.], Filmix [manufactured by Primix Corporation], Ultra Turrax [manufactured by IKA Japan Co., Ltd.], Ebara Mildar [manufactured by Ebara Corporation], Cavitron [manufactured by Eurotech], and Biomixer [manufactured by Nippon Seiki Co., Ltd.].

[0089] When dispersing the polyurethane resin (U) or urethane prepolymer (P) using a rotary dispersion mixer, the rotation speed is preferably 10 to 30,000 rpm, more preferably 20 to 20,000 rpm, and particularly preferably 30 to 10,000 rpm from the viewpoint of dispersion ability.

[0090] The main dispersion principle of the ultrasonic dispersion device is to apply energy from the outside to the processed material by the vibration of the drive unit to atomize and disperse it. In addition, the ultrasonic dispersion device can be operated under normal pressure, reduced pressure, or increased pressure.

[0091] As the ultrasonic dispersion device, ultrasonic dispersion devices commercially available from Ikamoto Rika Kogyo Co., Ltd., Cosmo Bio Co., Ltd., and Gin Sen Co., Ltd. can be used.

[0092] When dispersing the polyurethane resin (U) or urethane prepolymer (P) using an ultrasonic dispersion device, the vibration frequency is preferably 1 to 100 kHz, more preferably 3 to 60 kHz, and particularly preferably 10 to 30 kHz from the viewpoint of dispersion ability.

[0093] The main dispersion principle of the kneader is to apply energy by kneading the processed material in the rotating part of the kneader to atomize and disperse it. In addition, the kneader can be operated under normal pressure, reduced pressure, or increased pressure.

[0094] Examples of the kneader include twin-screw extruders [PCM-30 manufactured by Ikegai Corporation, etc.], kneaders [KRC kneader manufactured by Kurimoto Iron Works, Ltd., etc.], universal mixers [High Bis Mix manufactured by Primix Corporation, etc.], and plast mills [Laboplast Mill manufactured by Toyo Seiki Seisakusho, Ltd., etc.].

[0095] When dispersing the polyurethane resin (U) or urethane prepolymer (P) using a kneader, from the viewpoint of dispersion ability, the rotation speed is preferably 1 to 1000 rpm, more preferably 3 to 500 rpm, and particularly preferably 10 to 200 rpm.

[0096] The weight ratio of the polyurethane resin (U) or urethane prepolymer (P) to water supplied to the dispersing device is appropriately selected according to the resin component content of the target aqueous dispersion, but is preferably [(U) or (P)] / water = 10 / 2 to 10 / 100, and more preferably 10 / 5 to 10 / 50.

[0097] Also, the time for treating the polyurethane resin (U) or urethane prepolymer (P) and water in the dispersing device, from the viewpoint of dispersibility, is preferably 10 seconds to 10 hours, more preferably 1 minute to 3 hours, and most preferably 10 to 60 minutes.

[0098] When performing dispersion in the dispersing device, if necessary, one or more additives selected from pH adjusters, defoamers, antifoaming agents, antioxidants, anti-coloring agents, plasticizers, and mold release agents can be added. Also, if necessary, desolvation, concentration, dilution, etc. may be performed after dispersion.

[0099] Examples of the method for neutralizing the polyurethane resin (U) or urethane prepolymer (P) generated by the above reaction with the above neutralizing agent to obtain the polyurethane resin (U1) or the precursor of the polyurethane resin (U1) include adding the above neutralizing agent to a solution containing the polyurethane resin (U) or urethane prepolymer (P) and stirring at 10 to 50°C for 10 to 180 minutes to neutralize the acidic groups of the polyurethane resin (U) or urethane prepolymer (P).

[0100] As an apparatus for reacting the chain extender (A4) and, if necessary, the reaction terminator (A5) after dispersing the urethane prepolymer (P), there is no particular limitation, but it is preferable to carry out the reaction while mixing with the above-mentioned dispersing device or a static mixer or the like.

[0101] The aqueous dispersion (Q) of the polyurethane resin of the present invention may contain a polyurethane resin (U') other than the polyurethane resin (U) and the polyurethane resin (U1), which is a polyurethane resin (U'1) having a viscosity at 25°C measured at a shear rate of 0.1 / s using a rheometer exceeding 1,000,000 Pa·s, as long as the effects of the invention are not inhibited. From the viewpoint of the cleanability of the coating gun, the weight ratio of the above-mentioned polyurethane resin (U'1) is preferably 40% by weight or less, preferably 10% by weight or less, particularly preferably 5% by weight or less, and most preferably 1% by weight or less, based on the total weight of the polyurethane resin (U) and the polyurethane resin (U1).

[0102] From the viewpoints of the chemical resistance and mechanical properties of the film, the aqueous dispersion (Q) of the polyurethane resin of the present invention preferably contains a crosslinking agent (C) having two or more reactive groups capable of reacting with the active hydrogen-containing groups (such as hydroxyl groups) of the polyurethane resin (U) in the molecule. In the aqueous dispersion (Q) of the polyurethane resin of the present invention, a mixture of the polyurethane resin (U) and the crosslinking agent (C) may form one particle, or the polyurethane resin (U) and the crosslinking agent (C) may exist in the state of separate particles. Incidentally, the crosslinking agent (C) can also be subjected to a crosslinking reaction with the acidic groups of the polyurethane resin (U).

[0103] Examples of the crosslinking agent (C) include at least one crosslinking agent selected from the group consisting of a blocked isocyanate compound (c1), a melamine compound (c2), an oxazoline compound (c3), a carbodiimide compound (c4), an aziridine compound (c5), and an epoxy compound (c6).

[0104] The blocked isocyanate compound (c1) is not particularly limited as long as it has two or more blocked isocyanate groups in the molecule. For example, the polyisocyanate compounds exemplified as the organic polyisocyanate component (B) are blocked with known blocking agents [phenols, secondary or tertiary alcohols, oximes, aliphatic or aromatic secondary amines, phthalimides, lactams, active methylene compounds (such as dialkyl malonate), pyrazole-based compounds (such as pyrazole and 3,5-dimethylpyrazole), and sodium bisulfite, etc.].

[0105] Examples of commercially available blocked isocyanate compounds (c1) include the Duranate series (such as Duranate 17B-60P, TPA-B80E, MF-B60B, MF-K60B, SBB-70P, SBN-70D, SBF-70E, E402-B80B, and WM44-L70G, etc.) manufactured by Asahi Kasei Chemicals Corporation.

[0106] The melamine compound (c2) is not particularly limited as long as it is a methylolated melamine compound or a methoxymethylolated melamine compound having two or more methylol groups or methoxymethylol groups in the molecule. For example, the Uban series [such as Uban 120, 20HS, 2021, 2028, 228, 2860, and 22R, etc.] manufactured by Mitsui Chemicals, Inc., the Cymel series (such as Cymel 202, 232, 235, 238, 254, 266, 267, 272, 285, 301, 303, 325, 327, 350, 370, 701, 703, 736, 738, 771, 114, 1156, and 1158, etc.) manufactured by Nippon Cytec Industries, Inc., and the Sumimal series (such as Sumimal M-30W, M-50W, M-55, M-66B, and 50B, etc.) manufactured by Sumitomo Chemical Co., Ltd.

[0107] The oxazoline compound (C3) is not particularly limited as long as it has two or more oxazoline groups (oxazoline skeletons) in the molecule. Examples thereof include compounds having two or more oxazoline groups such as 2,2'-isopropylidenebis(4-phenyl-2-oxazoline); (co)polymers of polymerizable oxazoline compounds such as 2-isopropenyl-2-oxazoline, 2-vinyl-2-oxazoline, and 2-vinyl-4-methyl-2-oxazoline; copolymers of the polymerizable oxazoline compound and a copolymerizable monomer that does not react with the oxazoline group [(meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and polyethylene glycol (meth)acrylate, vinyl acrylamide acetate, styrene, and sodium styrenesulfonate, etc.]. Commercially available products of the oxazoline compound (C3) include "Epocros K-2010E", "Epocros K-2020E", and "Epocros WS-500" manufactured by Nippon Shokubai Co., Ltd., etc.

[0108] The carbodiimide compound (c4) is not particularly limited as long as it has two or more carbodiimide groups in the molecule. For example, the aliphatic polyisocyanate (b1) having 4 to 22 carbon atoms, the alicyclic polyisocyanate (b2) having 8 to 18 carbon atoms, the araliphatic polyisocyanate (b3) having 10 to 17 carbon atoms, or the aromatic polyisocyanate (b4) having 8 to 22 carbon atoms is polymerized to obtain an aliphatic polycarbodiimide [such as poly(hexamethylene carbodiimide)], an alicyclic polycarbodiimide [such as poly(4,4'-dicyclohexylmethane carbodiimide)], and an aromatic polycarbodiimide [such as poly(p-phenylene carbodiimide), poly(4,4'-diphenylmethane carbodiimide), and poly(diisopropylphenyl carbodiimide)]. Examples of commercially available carbodiimide compounds (c4) include "Carbodilite V-01", "Carbodilite V02", "Carbodilite V-03", "Carbodilite V-04", "Carbodilite V-05", "Carbodilite V-07", "Carbodilite V-09", "Carbodilite E-02", "Carbodilite E-03A", and "Carbodilite E-04" manufactured by Nisshinbo Industries, Inc.

[0109] The aziridine compound (c5) is not particularly limited as long as it has two or more aziridinyl groups in the molecule. For example, tetramethylolmethane tris(β-aziridinylpropionate) and trimethylolpropane tris(β-aziridinylpropionate) can be mentioned.

[0110] The epoxy compound (c6) is not particularly limited as long as it has two or more epoxy groups in the molecule. For example, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol polyglycidyl ether, hydrogenated bisphenol A diglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, and polypropylene glycol diglycidyl ether can be mentioned.

[0111] The crosslinking agent (C) may be used alone or in combination of two or more thereof.

[0112] The content of the crosslinking agent (C) in the polyurethane resin aqueous dispersion (Q) is preferably 30% by weight or less, more preferably 0.1 to 25% by weight, based on the solid content weight of the polyurethane resin aqueous dispersion (Q).

[0113] The solid content concentration [weight ratio of components other than volatile components (solid content)] of the polyurethane resin aqueous dispersion (Q) obtained by the production method of the present invention is preferably 20 to 65% by weight, more preferably 25 to 55% by weight, from the viewpoint of ease of handling of the aqueous dispersion. The solid content concentration can be obtained by thinly spreading about 1 g of the aqueous dispersion on a Petri dish, precisely weighing it, then precisely weighing the weight after heating at 130 °C for 45 minutes using a circulating constant temperature dryer, and calculating the ratio (percentage) of the residual weight after heating to the weight before heating. Also, the ratio of the total weight of the polyurethane resin (U) which is a precursor of the polyurethane resin (U) and the polyurethane resin (U1) contained in the polyurethane resin aqueous dispersion (Q) is preferably 15 to 100% by weight, more preferably 25 to 100% by weight, particularly preferably 40 to 100% by weight, and most preferably 55 to 100% by weight, based on the weight of the solid content of the polyurethane resin aqueous dispersion (Q). Also, the ratio of the total weight of the polyurethane resin (U) which is a precursor of the polyurethane resin (U) and the polyurethane resin (U1) contained in the polyurethane resin aqueous dispersion (Q) is preferably 20 to 100% by weight, more preferably 30 to 100% by weight, particularly preferably 45 to 100% by weight, and most preferably 60 to 100% by weight, based on the weight obtained by subtracting the weight of the crosslinking agent (C) from the weight of the solid content of the polyurethane resin aqueous dispersion (Q).

[0114] The viscosity of the aqueous dispersion (Q) of the polyurethane resin obtained by the production method of the present invention is preferably 10 to 100,000 mPa·s, more preferably 10 to 5,000 mPa·s. The viscosity is a value measured at a constant temperature of 25°C using a BL type viscometer.

[0115] The pH of the aqueous dispersion (Q) of the polyurethane resin obtained by the production method of the present invention is preferably 2 to 12, more preferably 4 to 10. The pH is a value measured at 25°C using a pH Meter M-12 [manufactured by Horiba, Ltd.].

[0116] <Use> The aqueous dispersion (Q) of the polyurethane resin of the present invention can be used in aqueous paint compositions, aqueous adhesive compositions, aqueous fiber processing treatment agent compositions (such as pigment printing binder compositions, non-woven fabric binder compositions, reinforcing fiber sizing agent compositions, antibacterial agent binder compositions, and artificial leather / synthetic leather raw material compositions), aqueous coating compositions (such as waterproof coating compositions, water-repellent coating compositions, and antifouling coating compositions), aqueous paper treatment agent compositions, and aqueous ink compositions. However, due to its excellent film-forming properties and water resistance, it can be particularly preferably used as an aqueous paint composition, an aqueous adhesive composition, and an aqueous fiber processing treatment agent composition.

[0117] When used in these applications, if necessary, one or more other additives, such as film-forming auxiliary resins, crosslinking agents, catalysts, pigments, pigment dispersants, viscosity modifiers, defoamers, leveling agents, preservatives, anti-degradants, stabilizers, and anti-freezing agents, can be added.

[0118] The preparation of an aqueous paint using the aqueous dispersion (Q) of the polyurethane resin of the present invention will be described below. For the aqueous paint, for the purpose of assisting film formation and improving the binder function, etc., if necessary, in addition to the urethane resin (U) in the aqueous dispersion (Q) of the polyurethane resin of the present invention, other water-dispersible resins or water-soluble resins may be used in combination. Moreover, the aqueous dispersion (Q) of the polyurethane resin used in the aqueous paint preferably contains the above-mentioned crosslinking agent (C).

[0119] Examples of other water-dispersible resins or water-soluble resins used in combination with the aqueous paint include, for example, water-dispersible or water-soluble polyurethane resins other than the polyurethane resin in the present invention, polyacrylic resins, polyester resins, and the like. These other resins can be appropriately selected from those commonly used in each application according to the use of the aqueous paint.

[0120] The solid content of the polyurethane resin aqueous dispersion (Q) of the present invention in the aqueous paint is preferably 0.1 to 60% by weight, more preferably 1 to 50% by weight based on the weight of the aqueous paint. Also, the content of other resins in the aqueous paint is preferably 60% by weight or less, more preferably 50% by weight or less based on the weight of the aqueous paint.

[0121] The addition amount of the crosslinking agent (C) contained in the aqueous paint is preferably 30% by weight or less, more preferably 0.1 to 20% by weight based on the solid content weight of the aqueous paint.

[0122] The aqueous paint can further contain one or more of a pigment, a pigment dispersant, a viscosity modifier, an antifoaming agent, a preservative, an anti-degradant, a stabilizer, an anti-freezing agent, and water.

[0123] Examples of the pigment include inorganic pigments having a solubility in water of 1 or less (for example, white pigments, black pigments, gray pigments, red pigments, brown pigments, yellow pigments, green pigments, blue pigments, purple pigments, and metallic pigments) and organic pigments (for example, natural organic pigments, synthetic organic pigments, nitroso pigments, nitro pigments, pigment dye type azo pigments, azo lakes made from water-soluble dyes, azo lakes made from hardly soluble dyes, lakes made from basic dyes, lakes made from acidic dyes, xanthane lakes, anthraquinone lakes, pigments from vat dyes, and phthalocyanine pigments). The content of the pigment is preferably 50% by weight or less, more preferably 30% by weight or less based on the weight of the aqueous paint. Examples of the pigment dispersant include the above-described dispersant (g), and the content of the pigment dispersant is preferably 20% by weight or less, more preferably 15% by weight or less, based on the weight of the pigment.

[0124] Examples of the viscosity modifier include thickeners such as inorganic viscosity modifiers (sodium silicate, bentonite, etc.), cellulose-based viscosity modifiers (methyl cellulose, carboxymethyl cellulose, hydroxymethyl cellulose, etc. with Mn of 20,000 or more), protein-based viscosity modifiers (casein, sodium caseinate, ammonium caseinate, etc.), acrylic-based (sodium polyacrylate, ammonium polyacrylate, etc. with Mn of 20,000 or more), and vinyl-based viscosity modifiers (polyvinyl alcohol, etc. with Mn of 20,000 or more). Examples of the defoamer include long-chain alcohols (such as octyl alcohol), sorbitan derivatives (such as sorbitan monooleate), silicone oils (such as polymethylsiloxane and polyether-modified silicone), etc.

[0125] Examples of the preservative include organic nitrogen-sulfur compound-based preservatives and organic sulfur-halide-based preservatives, etc. Examples of the anti-degradant and stabilizer (such as ultraviolet absorber and antioxidant) include hindered phenol-based, hindered amine-based, hydrazine-based, phosphorus-based, benzophenone-based, and benzotriazole-based anti-degradants and stabilizers, etc. Examples of the antifreeze include ethylene glycol and propylene glycol, etc. The contents of the viscosity modifier, defoamer, preservative, anti-degradant, stabilizer, and antifreeze are each preferably 5% by weight or less, more preferably 3% by weight or less, based on the weight of the aqueous paint.

[0126] For the aqueous paint, a solvent may be further added for the purpose of improving the appearance of the dried coating film. Examples of the solvent to be added include monohydric alcohols having 1 to 20 carbon atoms (such as methanol, ethanol, and propanol), glycols having 1 to 20 carbon atoms (such as ethylene glycol, propylene glycol, and diethylene glycol), trihydric or higher alcohols having 1 to 20 carbon atoms (such as glycerin), and cellosolves having 1 to 20 carbon atoms (such as methyl and ethyl cellosolve). The content of the solvent to be added is preferably 20% by weight or less, more preferably 15% by weight or less, based on the weight of the aqueous paint.

[0127] The aqueous paint using the polyurethane resin aqueous dispersion (Q) of the present invention is produced by mixing and stirring the polyurethane resin aqueous dispersion (Q) of the present invention and each of the components described above. When mixing, all the components may be mixed simultaneously, or each component may be added stepwise and mixed. The solid content concentration of the aqueous paint is preferably 10 to 70% by weight, more preferably 15 to 60% by weight.

[0128] Hereinafter, the aqueous adhesive using the polyurethane resin aqueous dispersion (Q) of the present invention will be described. As the resin to be used in the aqueous adhesive, the polyurethane resin (U) and / or the polyurethane resin (U1) in the polyurethane resin aqueous dispersion (Q) of the present invention may be used as they are, but water-dispersible or water-soluble resins other than the polyurethane resin typified by SBR latex resin and acrylic resin can be used in combination. When used in combination, the proportion of the total weight of the polyurethane resin (U) and the polyurethane resin (U1) in the total weight of the resin is preferably 1% by weight or more, more preferably 10% by weight or more.

[0129] Furthermore, auxiliary materials and additives used in the adhesive, such as crosslinking agents, plasticizers, tackifiers, fillers, pigments, thickeners, antioxidants, ultraviolet absorbers, surfactants, and flame retardants, can also be used within a range that does not inhibit the cohesiveness of the adhesive containing the polyurethane resin aqueous dispersion (Q) of the present invention.

[0130] The base material (adherend) to which the adhesive is applied is not particularly limited. A laminate of adherends obtained using an adhesive is also included in the present invention.

[0131] Hereinafter, the preparation of an aqueous fiber processing agent using the polyurethane resin aqueous dispersion (Q) of the present invention will be described. In the fiber processing agent containing the polyurethane resin aqueous dispersion (Q) of the present invention, if necessary, known defoamers, wetting agents, various resin aqueous dispersions (polyurethane aqueous dispersions other than the present invention, acrylic aqueous dispersions, SBR latex, etc.) and softening agents can be blended. The blending amounts of these are preferably 30% by weight or less (more preferably 20% by weight or less) based on the total weight of the polyurethane resin (U) and the polyurethane resin (U1) in terms of solid content in the case of the resin aqueous dispersion, and preferably 1% by weight or less (more preferably 0.1 to 0.5% by weight) for each of the other additives. Also, if necessary, a pH adjuster can be added. Examples of the pH adjuster include salts of alkaline substances such as strong bases (alkali metals, etc.) and weak acids (acids with a pKa exceeding 2.0, such as carbonic acid and phosphoric acid) (such as sodium bicarbonate), or acidic substances (such as acetic acid). The amount of the pH adjuster is preferably 0.01 to 0.3% by weight based on the total weight of the polyurethane resin (U) and the polyurethane resin (U1).

[0132] The solid content (non-volatile content) concentration of the above-mentioned aqueous fiber processing agent is not particularly limited, but is preferably 10 to 50% by weight, more preferably 15 to 45% by weight. Also, the viscosity (25°C) is preferably 10 to 100,000 mPa·s.

Examples

[0133] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Hereinafter, "parts" means parts by weight.

[0134] <Example 1> A simple pressure reactor equipped with a stirrer and a heating device was charged with a polymer polyol (A1), a low molecular weight polyol (A2), a compound (A3), an organic polyisocyanate component (B), and an organic solvent as the active hydrogen component (A) described in Table 1 in the weights described in Table 1, and stirred at 95 °C for 15 hours to carry out a urethanization reaction to produce an acetone solution of a polyurethane resin. While stirring 500 parts of the obtained acetone solution of the polyurethane resin at 30 °C, 5.09 parts of triethylamine as a neutralizing agent was added, homogenized at 60 rpm for 30 minutes, then the temperature was maintained at 30 °C, and 651.56 parts of ion-exchanged water was gradually added with stirring at 500 rpm to carry out an emulsification operation. Next, after carrying out an operation to distill off acetone under reduced pressure at 65 °C for 12 hours, ion-exchanged water was added as necessary to adjust the solid content concentration of the finally obtained aqueous dispersion (Q) of the polyurethane resin to 35% by weight, and a filtration operation was carried out by filtering with a SUS mesh having an opening of 100 μm to obtain an aqueous dispersion (Q-1) of the polyurethane resin containing the polyurethane resin (U1).

[0135] <Examples 2 to 11> In Example 1, the same procedure as in Example 1 was carried out except that the types and weights of the active hydrogen component (A), the organic polyisocyanate component (B), the organic solvent, the neutralizing agent, and the ion-exchanged water were changed to the contents described in Table 1, and aqueous dispersions (Q-2) to (Q-11) of the polyurethane resin containing the polyurethane resin (U1) were obtained. In Example 6, a chain extender (A4) was added as the active hydrogen component (A).

[0136] <Example 12> In a simple pressurized reactor equipped with a stirrer and a heating device, a polymer polyol (A1), a low molecular weight polyol (A2), a compound (A3), an organic polyisocyanate component (B), and an organic solvent as the active hydrogen component (A) described in Table 1 were charged in the weights described in Table 1, and stirred at 95 °C for 15 hours to carry out a urethanization reaction, thereby producing an acetone solution of a urethane prepolymer (isocyanate group content in the solution: 1.8% by weight). The above isocyanate group content was measured in accordance with JIS K7301-1995, 6.3 Isocyanate Group Content Ratio. To the obtained acetone solution of the urethane prepolymer, a reaction terminator (A5) as the active hydrogen component (A) described in Table 1 was added while stirring at 30 °C, and homogenized at 60 rpm for 60 minutes to produce an acetone solution of a polyurethane resin. While stirring the obtained acetone solution of the polyurethane resin at 30 °C, 4.49 parts of triethylamine as a neutralizing agent was added, and after homogenizing at 60 rpm for 30 minutes, the temperature was maintained at 30 °C, and 628.83 parts of ion-exchanged water was gradually added with stirring at 500 rpm to carry out an emulsification operation. Next, after carrying out a distillation operation of acetone under reduced pressure at 65 °C for 12 hours, ion-exchanged water was added as necessary to adjust the solid content concentration of the finally obtained aqueous dispersion (Q) of the polyurethane resin to 35% by weight, and a filtration operation was carried out by filtering with a SUS mesh having an opening of 100 μm to obtain an aqueous dispersion (Q-12) of a polyurethane resin containing a polyurethane resin (U1).

[0137] <Examples 13 to 14 and 16> In Example 12, the same procedure as in Example 12 was carried out except that the types and weights of the active hydrogen component (A), the organic polyisocyanate component (B), the organic solvent, the neutralizing agent, and the ion-exchanged water were changed to the contents described in Table 1, to obtain aqueous dispersions (Q-13) to (Q-14) and (Q-16) of a polyurethane resin containing a polyurethane resin (U1).

[0138] <Example 15> In Example 12, the procedure was the same as in Example 12 except that the weights of the polymer polyol (A1), low molecular weight polyol (A2), compound (A3), organic polyisocyanate component (B), and organic solvent as the active hydrogen component (A) were changed to the contents described in Table 1, and an acetone solution of the urethane prepolymer (isocyanate group content in the solution: 1.25% by weight) was produced. The procedure was the same as in Example 12 except that the weights of the active hydrogen component (A5), neutralizing agent, and ion-exchanged water were changed to the contents described in Table 1, and an aqueous polyurethane resin dispersion (Q-15) containing the polyurethane resin (U1) was obtained.

[0139] <Example 17> Into a simple pressure reactor equipped with a stirrer and a heating device, the polymer polyol (A1), low molecular weight polyol (A2), compound (A3), organic polyisocyanate component (B), and organic solvent as the active hydrogen component (A) described in Table 1 were charged in the weights described in Table 1, and stirred at 95 °C for 15 hours to conduct a urethanization reaction, and an acetone solution of the urethane prepolymer (isocyanate group content in the solution: 1.8% by weight) was produced. While stirring the obtained acetone solution of the urethane prepolymer at 30 °C, 4.72 parts of triethylamine as a neutralizing agent was added, homogenized at 60 rpm for 30 minutes, then the temperature was maintained at 30 °C, and while stirring at 500 rpm, 1.19 parts of a chain extender (A4) as the active hydrogen component (A), 8.06 parts of a reaction terminator (A5) as the active hydrogen component (A), and an aqueous solution prepared by previously mixing 622.55 parts of ion-exchanged water were gradually added to the urethane prepolymer solution to conduct an emulsification operation. Next, after conducting an operation to distill off acetone under reduced pressure at 65 °C for 12 hours, ion-exchanged water was added as necessary to adjust the solid content concentration of the finally obtained aqueous polyurethane resin dispersion (Q) to 35% by weight, and a filtration operation was conducted by filtering with a SUS mesh having an opening of 100 μm to obtain an aqueous polyurethane resin dispersion (Q-17) containing the polyurethane resin (U1).

[0140] <Example 18> In Example 17, the polyurethane resin aqueous dispersion (Q-18) containing the polyurethane resin (U1) was obtained in the same manner as in Example 17, except that the types and weights of the active hydrogen component (A), the organic polyisocyanate component (B), the organic solvent, the neutralizing agent, and the ion-exchanged water were changed to those described in Table 1.

[0141] <Example 19> 90 parts by weight of the polyurethane resin aqueous dispersion (Q-12) produced in Example 12 and 10 parts by weight of the polyurethane resin aqueous dispersion (Q'-1) produced in Comparative Example 1 below were mixed to obtain a polyurethane resin aqueous dispersion (Q-19) containing the polyurethane resin (U1).

[0142] <Comparative Example 1> Into a simple pressure reactor equipped with a stirrer and a heating device, the active hydrogen component (A), the organic polyisocyanate component (B), and the organic solvent described in Table 2 were charged in the weights described in Table 2, and stirred at 95°C for 15 hours to carry out a urethanization reaction, thereby producing an acetone solution of a urethane prepolymer (a resin having an isocyanate group at the terminal). For the obtained acetone solution of the urethane prepolymer, an emulsification operation was carried out in the same manner as in Example 1, except that the weights of triethylamine and ion-exchanged water were changed to those described in Table 2. The obtained emulsion was stirred at 60°C for 10 hours to carry out a chain extension reaction (an extension reaction through the reaction of the isocyanate group of the urethane prepolymer with water), and then, in the same manner as in Example 1, operations from the distillation operation of acetone to the filtration operation were carried out to obtain a comparative polyurethane resin aqueous dispersion (Q'-1) containing a comparative polyurethane resin (U1').

[0143] <Comparative Examples 2 to 3> In Example 1, the comparative polyurethane resin aqueous dispersions (Q'-2) to (Q'-3) containing the comparative polyurethane resin (U1') were obtained in the same manner as in Example 1, except that the types and weights of the active hydrogen component (A), the organic polyisocyanate component (B), the organic solvent, the neutralizing agent, and the ion-exchanged water were changed to those described in Table 2.

[0144] <Comparative Example 4> In a simple pressure reactor equipped with a stirrer and a heating device, the active hydrogen component (A) described in Table 2 was charged in the weight described in Table 2, and heated and stirred at 120 ° C for 3 hours under reduced pressure (1.3 kPa). After cooling to 25 ° C, the organic polyisocyanate component (B) described in Table 2 was charged in the weight described in Table 2, and stirred at 95 ° C for 15 hours to carry out a urethanization reaction. After cooling to 25 ° C, acetone of the weight described in Table 2 was added and stirred to produce an acetone solution of the polyurethane resin. Next, an emulsification operation was carried out in the same manner as in Example 1 except that triethylamine was not added and the weight of ion-exchanged water was changed to the weight described in Table 2. Thereafter, in the same manner as in Example 1, from the operation of distilling off acetone to the filtration operation, a polyurethane resin aqueous dispersion (Q'-4) containing a comparative polyurethane resin (U1') was obtained.

[0145]

Table 1

[0146]

Table 2

[0147] The polymeric polyols (A1) used in Examples 1 to 19 and Comparative Examples 1 to 4 are as follows. PTMG650: [Polytetramethylene ether glycol with Mn = 650, Mw / Mn = 1.1, manufactured by Mitsubishi Chemical Corporation] PTMG1000: [Polytetramethylene ether glycol with Mn = 1,000, Mw / Mn = 1.1, manufactured by Mitsubishi Chemical Corporation], PTMG2000: [Polytetramethylene ether glycol with Mn = 2,000, Mw / Mn = 1.1, manufactured by Mitsubishi Chemical Corporation] Newport BPE-20T: [Ethylene oxide adduct of bisphenol A with [Mn = 321 and hydroxyl value of 349 mg KOH / g], manufactured by Sanyo Chemical Industries, Ltd.] Sunnex PP-2000: [Polyoxypropylene glycol with [Mn = 2,000], manufactured by Sanyo Chemical Industries, Ltd.] PEG-1000: [Polyethylene glycol with [Mn = 1,000], manufactured by Sanyo Chemical Industries, Ltd.]

[0148] The various physical property values and evaluation results of the aqueous polyurethane resin dispersions (Q-1) to (Q-19) and (Q'-1) to (Q'-4) obtained in Examples 1 to 19 and Comparative Examples 1 to 4 are shown in Tables 1 to 4. The measurement methods and evaluation methods for the various physical property values are as follows.

[0149]

Table 3

[0150]

Table 4

[0151] <Urethane group content and urea group content of polyurethane resins (U) and (U')> The aqueous polyurethane resin dispersion (Q) or (Q') was poured into a polypropylene mold with a length of 10 cm, a width of 20 cm, and a depth of 1 cm, dried at 25°C for 12 hours, and then heated and dried at 105°C for 3 hours in a circulating air dryer to obtain the polyurethane resin (U) or (U') for measurement. The urethane group content and urea group content of the polyurethane resins (U) and (U') were calculated from the N atom content quantified by a nitrogen analyzer [ANTEK7000 (manufactured by ANTEK)] and 1 the ratio of urethane groups and urea groups quantified by 1H-NMR and the allophanate group and biuret group contents described below. 1Regarding the H-NMR measurement, it was carried out by the method described in "Structural Study of Polyurethane Resins by NMR: Takeda Research Institute Report 34(2), 224-323(1975)". That is 1 When measuring H-NMR, in the case of using aliphatic isocyanate, the weight ratio of the urea group to the urethane group was measured from the ratio of the integrated value of hydrogen derived from the urea group around 6 ppm chemical shift to the integrated value of hydrogen derived from the urethane group around 7 ppm chemical shift, and the urethane group and urea group contents were calculated from the weight ratio and the above-mentioned N atom content, allophanate group and biuret group contents. In the case of using aromatic isocyanate, the weight ratio of the urea group to the urethane group was calculated from the ratio of the integrated value of hydrogen derived from the urea group around 8 ppm chemical shift to the integrated value of hydrogen derived from the urethane group around 9 ppm chemical shift, and the urethane group and urea group contents were calculated from the weight ratio and the above-mentioned N atom content, allophanate group and biuret group contents.

[0152] <Content of allophanate group and biuret group> The total content of the allophanate group and biuret group in the polyurethane resins (U) and (U') was calculated by gas chromatography [Shimadzu GC-9A (manufactured by Shimadzu Corporation)]. A 50 g DMF solution containing 0.01 wt% di-n-butylamine and 0.01 wt% naphthalene (internal standard) was prepared. The sample was weighed into a test tube with a stopper, 2 g of the above DMF solution was added, and the test tube was heated in a constant temperature water bath at 90 °C for 2 hours. After cooling to room temperature, 10 μl of acetic anhydride was added and shaken and stirred for 10 minutes. Then, 50 μl of di-n-propylamine was further added. After shaking for 10 minutes, gas chromatography measurement was performed. A blank measurement was carried out in parallel, and the amine consumption was determined from the difference from the test value, and the total content of the allophanate group and biuret group was measured. (Gas chromatography conditions) Apparatus: Shimadzu GC-9A Column: 10% PEG-20M on Chromosorb WAW DMLS 60 / 80mesh glass column 3mmφ×2m Column temperature: 160 °C, sample introduction part temperature: 200 °C, carrier gas: nitrogen 40 ml / min Detector: FID, Sample injection volume: 2 μL (Calculation formula for the total content of alohanate groups and burette groups) Total content of alohanate groups and burette groups = {(B - A) / B} × 0.00155 / S A: (Peak area of di-n-butylacetamide / Peak area of naphthalene) of the sample B: (Peak area of di-n-butylacetamide / Peak area of naphthalene) of the blank S: Amount of polyurethane resin sampled (g)

[0153] <Mw and Mn measurement method> Polyurethane resin (U) or (U’) or a high molecular polyol was added to DMF so that the solid content became 0.125 wt%, stirred and dissolved at room temperature for 1 hour, then filtered through a filter with a pore size of 0.3 μm, and the Mw and Mn of the components contained in the obtained filtrate were measured by GPC using DMF as the solvent and polystyrene as the molecular weight standard. When the solubility of the sample in the solvent used for measurement is less than 90 wt% [when dissolving in DMF so that the solid content concentration is 0.125 wt%, the actually dissolved sample is less than 0.1125 wt% (= 0.125 × 0.90)], the measurement accuracy of GPC decreases. In that case, since it is difficult to accurately measure the molecular weight, the molecular weight of the polyurethane resin was defined as infinite "∞". (GPC measurement conditions) Apparatus: "HLC-8220GPC" [manufactured by Tosoh Corporation] Column: "Guardcolumn α" + "TSKgel α-M" [both manufactured by Tosoh Corporation] Sample solution: 0.125 wt% dimethylformamide solution Eluent: Dimethylformamide Solution injection volume: 100 μL Flow rate: 1 ml / min Measurement temperature: 40 °C Detector: Refractive index detector Reference substance: Standard polystyrene (TSKstandard POLYSTYRENE) [manufactured by Tosoh Corporation]

[0154] <Method for Measuring Weight Ratio of Insoluble Components of Polyurethane Resins (U) and (U’)> The polyurethane resin aqueous dispersion (Q) or (Q’) was poured into a polypropylene mold with a length of 10 cm, a width of 20 cm, and a depth of 1 cm, dried at 25 °C for 12 hours, and then heat-dried at 105 °C for 3 hours in a circulating air dryer to obtain the polyurethane resin (U) or (U’) for measurement. 1 g of the obtained polyurethane resin (this weight is denoted as W) was charged into a pressure-resistant sealed container with an inner diameter of 6 cm and a depth of 12 cm together with a stirrer chip with a length of 3 cm, and 10 g of acetone at 25 °C, which is 10 times the weight of the polyurethane resin, was added, and the mixture was stirred at 80 °C for 180 minutes to obtain a mixed solution. The obtained mixed solution was filtered through a SUS mesh (mesh opening 75 μm) whose weight (W1) had been measured in advance, and then the filter residue was washed with acetone at 25 °C (the same weight as the acetone charged into the pressure-resistant sealed container: 10 g). After drying the filter residue and the SUS mesh at 105 °C for 30 minutes, the total weight (W2) was measured. The insoluble component was calculated by the following formula. Weight ratio of insoluble component (%) = {(W2 - W1) / W} × 100

[0155] <Method for Measuring Viscosity of Polyurethane Resins (U) and (U’)> The polyurethane resin aqueous dispersion (Q) or (Q’) was poured into a polypropylene mold with a length of 10 cm, a width of 20 cm, and a depth of 1 cm, dried at 25 °C for 12 hours, and then heat-dried at 105 °C for 3 hours in a circulating air dryer to obtain the polyurethane resin (U) or (U’) for measurement. The resin viscosity of the obtained polyurethane resin was measured using a rheometer (“MCR-302” manufactured by Anton Paar). (Measurement Conditions) Measurement jig: Parallel plate “PP-08” (diameter 8 mm) Distance between plates: 0.5 mm Measurement temperature: 25 °C Measurement mode: Rotation Shear rate: 0.1 / second When the obtained polyurethane resin formed a film and it was impossible to measure the viscosity under the said conditions, the resin viscosity was expressed as "∞".

[0156] <Acid value and hydroxyl value of polyurethane resin> The polyurethane resin aqueous dispersion (Q) or (Q') was poured into a polypropylene mold with a length of 10 cm, a width of 20 cm, and a depth of 1 cm, dried at 25°C for 12 hours, and then dried by heating at 105°C for 3 hours using a circulating air dryer to obtain the polyurethane resin (U) or (U') for measurement. The acid value and hydroxyl value of the polyurethane resins (U) and (U') were measured in accordance with JIS K0070 (1992).

[0157] <Evaluation method for storage stability> 3.5 parts of "Cymel202" (manufactured by ALLNEX) and 72 parts of the polyurethane resin aqueous dispersion were mixed under stirring at 25°C and 2000 rpm to obtain a mixture. The viscosity of the mixture was measured (V1). After storing the mixture at 40°C for 10 days, the viscosity was measured (V2). The thickening rate was calculated by the following formula, and the storage stability was evaluated according to the following criteria. Thickening rate (%) = (V2 - V1) / V1 × 100 ○: -50% ≤ thickening rate ≤ +50% △: -100% ≤ thickening rate < -50% or +50% < thickening rate ≤ +100% ×: thickening rate < -100% or +100% < thickening rate

[0158] <Viscosity measurement conditions> Measuring instrument: B-type viscometer Rotation speed: 60 rpm

[0159] <Evaluation method for paint gun cleanability> 70 parts of rutile-type titanium dioxide, 10 parts of "Disperbyk 190" (manufactured by Big Chem Japan), and 34.3 parts of ion-exchanged water were pre-mixed, and then dispersed for 30 minutes using a paint shaker to obtain a pigment dispersion paste. 205.71 parts of the urethane resin aqueous dispersion and 10 parts of "Cymel202" were added to the obtained pigment paste and mixed uniformly to obtain a paint for evaluating paint gun cleanability. Using a metallic bell (manufactured by ABB), the paint was discharged for 10 seconds under the conditions of an applied voltage of -90 kV, a rotational speed of 30,000 rpm, and a discharge rate of 200 cc / min. After repeating the process of discharging for 10 seconds and leaving it standing for 60 seconds 10 times, a cleaning thinner (water / butyl cellosolve / N,N-dimethylethanolamine = 85 / 14 / 1 (weight ratio)) was discharged for 10 seconds and the removal state of the paint during cleaning was evaluated according to the following criteria. ◎: There is no paint residue inside the bell, and there is no paint residue in the discharge holes at all. ○: There is no paint residue inside the bell, and the paint residue in the discharge holes is also at a level that does not cause problems in painting. △: A little paint remains inside the bell, and a little paint also remains in the discharge holes. ×: Considerable paint remains inside the bell and in the discharge holes.

[0160] <Evaluation method of coating film appearance> The paint for evaluating the cleaning property of the coating gun was applied by air spraying to a commercially available cationic electrodeposition coating test piece so that the film thickness became 20 μm. After preheating at 80 °C for 5 minutes, heat curing was carried out at 140 °C for 30 minutes to obtain a test piece with a formed coating film. The quality (○ or ×) of the coating film appearance of the test piece was evaluated visually.

[0161] <Evaluation method of water-tight adhesion> 3.3 parts of "Cymel327" and 20 parts of an aqueous dispersion of polyurethane resin were mixed under stirring at 25 °C and 2000 rpm to obtain a mixture. The mixture was applied to a commercially available cationic electrodeposition coating test piece by air spraying to a thickness of 20 μm. After preheating at 80 °C for 5 minutes, heat curing was carried out at 140 °C for 30 minutes to obtain a coating film. The obtained coating film was immersed in warm water at 40 °C for 240 hours, then pulled out, the surface moisture was removed with a dry cloth, and then dried at 25 °C for 2 hours. Subsequently, six orthogonal cuts were made on the coating film surface at 1 mm intervals vertically and horizontally, and then a peeling test was carried out with cellophane tape (registered trademark), and the number of remaining 1 mm square coating films was examined. The adhesion was evaluated according to the following criteria. ◎: The remaining number is 24 or more ○: The remaining number is 20 or more and less than 24 △: Residual number is 15 or more and less than 20 ×: Residual number is less than 15

[0162] <Method for Evaluating Heat-Resistant Water Adhesion> The coating film for evaluating water adhesion was immersed in warm water at 80 °C for 168 hours, then pulled out, and the surface moisture was removed with a dry cloth, and then dried at 25 °C for 2 hours. Subsequently, six orthogonal cuts were made on the coating film surface at 1 mm intervals vertically and horizontally, and then a peeling test was performed with cellophane tape (registered trademark), and the number of remaining 1 mm square coating films was examined. The adhesion was evaluated according to the following criteria. ◎: Residual number is 24 or more ○: Residual number is 20 or more and less than 24 △: Residual number is 15 or more and less than 20 ×: Residual number is less than 15

Industrial Applicability

[0163] The aqueous dispersion of polyurethane resin of the present invention is excellent in storage stability and cleanability after using a coating gun, and can obtain a film excellent in appearance, water adhesion and heat-resistant water adhesion after coating. Therefore, it can be suitably used in coating compositions, adhesive compositions, fiber processing treatment agent compositions and the like.

Claims

1. A polyurethane resin aqueous dispersion containing a polyurethane resin (U) having an acidic group with an active hydrogen component (A) and an organic polyisocyanate component (B) as essential constituent monomers and / or a polyurethane resin (U1) obtained by neutralizing the acidic group of the polyurethane resin (U), and an aqueous medium, wherein the active hydrogen component (A) contains polytetramethylene ether glycol having a number average molecular weight of 500 or more, the polyurethane resin (U) has a hydroxyl group, the acid value of the polyurethane resin (U) is 5 to 18 mgKOH / g, and the weight average molecular weight is 4,000 to 20,000, a polyurethane resin aqueous dispersion (Q) having a viscosity of 100 to 1,000,000 Pa·s at 25°C measured at a shear rate of 0.1 / s using a rheometer.

2. The polyurethane resin aqueous dispersion according to claim 1, wherein the weight ratio of the insoluble components generated when the polyurethane resin (U) and acetone having a weight 10 times that of the polyurethane resin (U) are stirred at 80°C for 180 minutes under sealing is 0 to 5% by weight based on the weight of the added polyurethane resin (U).

3. The polyurethane resin aqueous dispersion according to claim 1 or 2, wherein the urethane group content of the polyurethane resin (U) is 1.0 to 3.5 mmol / g based on the weight of (U).

4. The polyurethane resin aqueous dispersion according to any one of claims 1 to 3, wherein the urea group content of the polyurethane resin (U) is 0 to 0.8 mmol / g based on the weight of (U).

5. The polyurethane resin aqueous dispersion according to any one of claims 1 to 4, wherein the hydroxyl value of the polyurethane resin (U) is 15 to 100 mgKOH / g.

6. The polyurethane resin aqueous dispersion according to any one of claims 1 to 5, wherein the organic polyisocyanate component (B) contains a linear aliphatic polyisocyanate (b1) having 4 to 22 carbon atoms and / or an alicyclic polyisocyanate (b2) having 8 to 18 carbon atoms.

7. The polyurethane resin aqueous dispersion according to any one of claims 1 to 6, further containing at least one crosslinking agent (C) selected from the group consisting of a blocked isocyanate compound (c1), a melamine compound (c2), an oxazoline compound (c3), a carbodiimide compound (c4), an aziridine compound (c5), and an epoxy compound (c6).

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