Aqueous polyurethane resin composition, coating film, and article

Abstract

The present invention provides a water-based polyurethane resin composition, a coating film, and an article. The water-based polyurethane resin composition described above is capable of forming a coating film having excellent substrate adhesion and durability. The water-based polyurethane resin composition used is characterized by containing a polyurethane resin (A) and a water-based medium (B), the polyurethane resin (A) being prepared using a polyol compound (a1) and a polyisocyanate compound (a2) as essential raw materials, the polyol compound (a1) containing a polycarbonate diol (a1-1) and a phosphoric acid-modified polyol (a1-2).

Description

Technical Field

[0001] This invention relates to waterborne polyurethane resin compositions, films, and articles. Background Technology

[0002] Polyurethane resin compositions typically exhibit good adhesion to substrates and are capable of forming flexible coatings, thus finding applications in a variety of uses, including coatings and adhesives.

[0003] Polyurethane resins are widely used in the manufacture of synthetic leather (including artificial leather) due to their good mechanical strength and texture. To date, solvent-based polyurethane resins containing N,N-dimethylformamide (DMF) have been the mainstream in this application. However, against the backdrop of DMF restrictions in Europe, stricter VOC emission restrictions in China, and DMF restrictions imposed by large garment manufacturing enterprises, there is a demand for the removal of DMF from polyurethane resins used in synthetic leather production.

[0004] To address this trend, polyurethane resin compositions formed by dispersing polyurethane resins in water have been extensively studied (see, for example, Patent Document 1). However, although substitution studies are underway, their physical properties are often noted to be inferior to those of solvent-based compositions.

[0005] In addition, the coating application is also affected by the increasing demand for sustainable products, and there is a trend of CFP reduction due to desolventization and high solids content. However, for water-based materials, the substrate adhesion and durability are insufficient and cannot meet the increasingly higher performance requirements in recent years.

[0006] Therefore, in waterborne polyurethane resin compositions, materials with even better substrate adhesion and durability are sought.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2007-119749 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The problem to be solved by the present invention is to provide an aqueous polyurethane resin composition capable of forming a film with excellent substrate adhesion and durability.

[0012] Methods for solving problems

[0013] The inventors discovered that by using polycarbonate diol (a1-1) and phosphoric acid modified polyol (a1-2) as polyol compounds that become raw materials for polyurethane resins, the above-mentioned problems can be solved, and thus the present invention was completed.

[0014] Specifically, the present invention relates to the following waterborne polyurethane resin compositions, films, and articles, wherein the waterborne polyurethane resin composition is characterized by containing a polyurethane resin (A) and an aqueous medium (B), wherein the polyurethane resin (A) uses a polyol compound (a1) and a polyisocyanate compound (a2) as necessary reaction raw materials, and wherein the polyol compound (a1) contains polycarbonate diol (a1-1) and phosphoric acid modified polyol (a1-2).

[0015] The present invention provides the following embodiments.

[0016] [1] An aqueous polyurethane resin composition, characterized in that it contains a polyurethane resin (A) and an aqueous medium (B).

[0017] The polyurethane resin (A) mentioned above uses polyol compound (a1) and polyisocyanate compound (a2) as necessary reaction raw materials. The polyol compound (a1) contains polycarbonate diol (a1-1) and phosphoric acid modified polyol (a1-2).

[0018] [2] According to the aqueous polyurethane resin composition described in [1] above, the mass ratio of the polycarbonate diol (a1-1) to the phosphoric acid modified polyol (a1-2) [(a1-1) / (a1-2)] is in the range of 50 / 50 to 95 / 5.

[0019] [3] According to the aqueous polyurethane resin composition described in [1] or [2] above, wherein the phosphoric acid modified polyol (a1-2) is made from trifunctional polypropylene glycol as an essential raw material and has a structure in which at least one of the three hydroxyl groups of the polypropylene glycol is phosphorylated.

[0020] [4] The aqueous polyurethane resin composition according to any one of [1] to [3] above, wherein the polyurethane resin (A) further contains a neutralizing agent as a raw material, the neutralizing agent comprising an organic amine.

[0021] [5] The aqueous polyurethane resin composition according to any one of [1] to [4] above, wherein the polyurethane resin (A) has a salt composed of phosphoric acid and organic amine as a hydrophilic component.

[0022] [6] A film, characterized in that it is formed from an aqueous polyurethane resin composition described in any one of [1] to [5] above.

[0023] [7] An article characterized in that it has the membrane described in [6] above.

[0024] Invention Effects

[0025] The aqueous polyurethane resin composition of the present invention has excellent substrate adhesion and durability, and is therefore suitable for use as a material and coating agent for synthetic leather and artificial leather. Detailed Implementation

[0026] The waterborne polyurethane resin composition of the present invention is characterized by containing polyurethane resin (A) and an aqueous medium (B).

[0027] Regarding the polyurethane resin (A) mentioned above, polyol compound (a1) and polyisocyanate compound (a2) are essential raw materials.

[0028] As the aforementioned polyol compound (a1), a polyol compound comprising polycarbonate diol (a1-1) and phosphoric acid modified polyol (a1-2) is used.

[0029] Examples of polycarbonate diols (a1-1) include those obtained by reacting carbonates and / or carbonyl chlorides with diol compounds. It should be noted that, from the perspective of reducing environmental impact, the diol compounds may also be biomass-derived (hereinafter sometimes referred to as "bio-based"). It should be noted that, in this invention, "bio-based" means derived from plant materials such as sugarcane, corn, and castor oil.

[0030] Examples of the aforementioned carbonates include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, and propylene carbonate. These carbonates can be used alone or in combination of two or more.

[0031] Examples of the aforementioned diol compounds include, for instance, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentanediol, 1,6-hexanediol, 1,5-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,8-nonanediol, 1,10-decanediol, 2-ethyl-2-butyl-1,3-propanediol, and 1,12-dodecanediol, among other aliphatic diols; and cyclohexanediols such as 1,4-cyclohexanediol and 1,3-cyclohexanediol. These diol compounds can be used alone or in combination of two or more.

[0032] From the viewpoint of obtaining a waterborne polyurethane resin composition with excellent substrate adhesion and durability, the number average molecular weight of the above-mentioned polycarbonate diol (a1-1) is preferably in the range of 500 to 100,000, more preferably in the range of 700 to 4,000. It should be noted that, in this invention, the number average molecular weight of the polycarbonate polyol is expressed as a value determined by gel permeation chromatography (GPC) under the conditions described in the examples.

[0033] As the aforementioned phosphoric acid modified polyol (a1-2), for example, a phosphoric acid modified polyol that uses trifunctional polypropylene glycol as an essential raw material can be used, and examples include phosphoric acid modified polyols having a structure in which at least one of the three hydroxyl groups of the aforementioned polypropylene glycol is phosphorylated.

[0034] From the viewpoint of obtaining a waterborne polyurethane resin composition with excellent substrate adhesion and durability, the number average molecular weight of the above-mentioned phosphoric acid modified polyol (a1-2) is preferably in the range of 200 to 10,000, more preferably in the range of 400 to 3,000.

[0035] From the viewpoint of obtaining a waterborne polyurethane resin composition with excellent substrate adhesion and durability, the mass ratio of the above-mentioned polycarbonate diol (a1-1) to the above-mentioned phosphoric acid modified polyol (a1-2) [(a1-1) / (a1-2)] is preferably in the range of 50 / 50 to 95 / 5, more preferably in the range of 70 / 30 to 90 / 10.

[0036] From the viewpoint of obtaining an aqueous polyurethane resin composition with excellent substrate adhesion and durability, the amount of the above-mentioned polycarbonate diol (a1-1) and the above-mentioned phosphoric acid modified polyol (a1-2) used is preferably in the range of 10 to 100% by mass in the above-mentioned polyol compound (a1), more preferably in the range of 50 to 100% by mass, and even more preferably 100% by mass.

[0037] From the viewpoint of obtaining an aqueous polyurethane resin composition with excellent durability and substrate adhesion, the amount of the above-mentioned polyol compound (a1) used in the raw material of polyurethane resin (A) is preferably in the range of 50 to 90% by mass, and more preferably in the range of 60 to 80% by mass.

[0038] Regarding the aforementioned polyol compound (a1), other polyol compounds besides the aforementioned polycarbonate diol (a1-1) and the aforementioned phosphoric acid modified polyol (a1-2) may also be used as needed (hereinafter referred to as "other polyol compounds").

[0039] Other examples of the aforementioned polyol compounds include polyester polyols, polyether polyols, and polybutadiene polyols. These polyol compounds can be used alone or in combination of two or more.

[0040] Examples of polyester polyols include polyester polyols obtained by esterification of polycarboxylic acids with polyols.

[0041] Examples of the aforementioned polycarboxylic acids include, for instance, aromatic dicarboxylic acids or their esters such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenecarboxylic acid; succinic acid, glutaric acid, adipic acid, maleic acid, pimelic acid, octanoic acid, azelaic acid, itaconic acid, sebacic acid, chlorobacterial acid, 1,2,4-butane-tricarboxylic acid, decanedicarboxylic acid, cyclohexanedicarboxylic acid, dimer acids, and fumaric acid, etc. These polycarboxylic acids or their esters can be used alone or in combination of two or more.

[0042] Examples of the aforementioned polyols include aromatic diols such as benzenediethanol, toluenediethanol, and xylenediethanol, as well as aliphatic polyols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-diethanol, neopentyl glycol, and ethylene glycol. These polyols can be used alone or in combination of two or more.

[0043] In the esterification reaction during the manufacture of the aforementioned polyester polyols, an esterification catalyst is preferably used to promote the esterification reaction. Examples of such esterification catalysts include metals such as titanium, tin, zinc, aluminum, zirconium, magnesium, hafnium, and germanium; and metal compounds such as tetraisopropoxytitanium, tetrabutoxytitanium, acetylacetonate titanium oxide, dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, tin octoate, 2-ethylhexanetin, zinc acetylacetonate, zirconium tetrachloride, zirconium tetrachloride tetrahydrofuran complex, hafnium tetrachloride, hafnium tetrachloride tetrahydrofuran complex, germanium oxide, and tetraethoxygermanium. These esterification catalysts can be used alone or in combination of two or more.

[0044] Examples of the aforementioned polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxyethylene polyoxypropylene glycol, and polyoxyethylene polyoxytetramethylene glycol. These polyether polyols can be used alone or in combination of two or more.

[0045] From the viewpoint of obtaining an aqueous polyurethane resin composition with excellent substrate adhesion and durability, the number average molecular weight of the other polyol compounds mentioned above is preferably in the range of 200 to 100,000, more preferably in the range of 500 to 10,000.

[0046] The content of the other polyol compounds mentioned above is preferably in the range of 0 to 90% by mass in the polyol compound (a1).

[0047] Examples of the aforementioned polyisocyanate compounds (a2) include, for instance, aromatic polyisocyanates such as phenylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, polymethylene polyphenyl polyisocyanate, and carbodiimide diphenylmethane polyisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, phenylene diisocyanate, tetramethylphenylene diisocyanate, dimer acid diisocyanate, and norbornene diisocyanate; and alicyclic diisocyanates such as norbornene diisocyanate, isophorone diisocyanate, hydrogenated phenylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. These polyisocyanates can be used alone or in combination of two or more.

[0048] From the viewpoint of obtaining an aqueous polyurethane resin composition capable of forming a film with excellent substrate adhesion and durability, the amount of the aforementioned polyisocyanate compound (a2) used is preferably in the range of 10 to 40% by mass of the total mass of the raw materials of the aforementioned polyurethane resin (A), more preferably in the range of 12 to 37% by mass, and even more preferably in the range of 15 to 35% by mass.

[0049] Depending on the requirements, in addition to the polyol compound (a1) and the polyisocyanate compound (a2) mentioned above, the polyurethane resin (A) may also use a neutralizing agent (a3) ​​as a raw material.

[0050] Examples of neutralizing agents (a3) ​​mentioned above include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide, as well as amine compounds.

[0051] Examples of the aforementioned amine compounds include inorganic amines such as ammonia, alkylamines, alkanolamines, aminoalkyldiols, alkoxyamines, heterocyclic amines, and other organic amines. Among these, organic amines are preferred from the perspective of obtaining aqueous polyurethane resin compositions capable of forming films with excellent substrate adhesion and durability.

[0052] From the viewpoint of obtaining an aqueous polyurethane resin composition capable of forming a film with excellent substrate adhesion and durability, the amount of the neutralizing agent (a3) ​​used is preferably in the range of 1 to 15% by mass of the total mass of the raw materials of the polyurethane resin (A), and more preferably in the range of 2 to 10% by mass.

[0053] In addition, depending on the requirements, the polyurethane resin (A) may also use a chain extender (a4) as a raw material, in addition to the polyol compound (a1) and the polyisocyanate compound (a2).

[0054] Examples of chain extenders (a4) include hydroxyl-containing chain extenders such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylenediol, trimethylolpropane, and glycerol; and amino-containing chain extenders such as ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, isophorone diamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexanediamine, aminoethylethanolamine, hydrazine, diethylenetriamine, and triethylenetetramine. These chain extenders can be used alone or in combination of two or more. Furthermore, among these, from the perspective of obtaining an aqueous polyurethane resin composition capable of forming a film with excellent substrate adhesion and durability, chain extenders having hydroxyl groups are preferred, and ethylene glycol, diethylene glycol, 1,3-propanediol, and 1,4-butanediol are more preferred. Additionally, from the perspective of reducing environmental impact, bio-based ethylene glycol, bio-based 1,3-propanediol, and bio-based 1,4-butanediol may also be used.

[0055] From the viewpoint of obtaining an aqueous polyurethane resin composition capable of forming a film with excellent substrate adhesion and durability, the amount of the chain extender (a4) used is preferably in the range of 0.1 to 30% by mass of the total mass of the raw materials of the polyurethane resin (A), and more preferably in the range of 1 to 10% by mass.

[0056] Regarding the polyurethane resin (A) described above, from the perspective of obtaining an aqueous polyurethane resin composition capable of forming a film with excellent substrate adhesion and durability, a polyurethane resin having a salt composed of phosphoric acid and organic amine as a hydrophilic component is preferred.

[0057] Regarding the manufacturing method of the polyurethane resin (A) described above, there are no particular limitations, and it can be manufactured by any method. For example, it can be manufactured by reacting all the reactants, including the polyol compound (a1) and the polyisocyanate compound (a2), all at once, or by reacting the reactants sequentially. These reactions are preferably carried out at a temperature of 50 to 100°C for 3 to 10 hours.

[0058] Examples of aqueous media (B) mentioned above include ion-exchanged water and distilled water. These aqueous media can be used alone or in combination of two or more.

[0059] From the viewpoint of obtaining an aqueous polyurethane resin composition capable of forming a film with excellent substrate adhesion and durability, the mass ratio of the polyurethane resin (A) to the aqueous medium (B) [(A) / (B)] is preferably in the range of 20 / 80 to 80 / 20, and more preferably in the range of 30 / 70 to 70 / 30.

[0060] There are no particular limitations on the method for manufacturing the aqueous polyurethane resin composition of the present invention, and it can be manufactured by any method. For example, a method in which polyurethane resin (A) is mixed with an aqueous medium (B) can be cited.

[0061] As a method for mixing the aforementioned polyurethane resin (A) and the aforementioned aqueous medium (B), examples include methods using the following devices: a reaction vessel equipped with stirring blades; a kneader, continuous kneader, conical roller, single-screw extruder, twin-screw extruder, three-screw extruder, universal mixer, plastic mill, main mixer, etc.; a rotary dispersion mixer such as a homogenizer, static mixer, Filmix, Ebara Milder, Claire mix, ULTRA-TURRAX, Cavitron, bio-mixer, etc.; an ultrasonic dispersion device; an online mixer, etc., which has no moving parts and can mix by the flow of the fluid itself.

[0062] The aqueous polyurethane resin composition of the present invention may also contain other additives as needed.

[0063] Other additives mentioned above include, for example, emulsifiers, thickeners, polyurethane catalysts, fillers, flame retardants, leveling agents, and antiblocking agents. These additives can be used alone or in combination of two or more.

[0064] Examples of emulsifiers mentioned above include nonionic emulsifiers such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrene phenyl ether, polyoxyethylene sorbitan tetraoleate, and polyoxyethylene-polyoxypropylene copolymer; anionic emulsifiers such as fatty acid salts like sodium oleate, alkyl sulfate salts, alkylbenzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, polyoxyethylene alkyl sulfates, sodium alkyl sulfonates, and sodium alkyl diphenyl ether sulfonates; and cationic emulsifiers such as alkylamine salts, alkyl trimethylammonium salts, and alkyl dimethyl benzylammonium salts. These emulsifiers can be used alone or in combination of two or more.

[0065] Examples of thickeners mentioned above include associative thickeners and acid-based thickeners.

[0066] Examples of catalysts for the aforementioned polyurethane conversion include organotin and bismuth-based catalysts.

[0067] Examples of fillers mentioned above include calcium carbonate and silicon dioxide.

[0068] Examples of flame retardants mentioned above include phosphorus-based flame retardants.

[0069] Examples of leveling agents mentioned above include silicone-based leveling agents.

[0070] Examples of anti-blocking agents include acrylic and cellulose esters.

[0071] The film of the present invention comprises the above-described aqueous polyurethane resin composition.

[0072] As a method for forming the above-mentioned film, examples include coating a substrate with the aqueous polyurethane resin composition of the present invention and drying the aqueous medium.

[0073] Examples of the aforementioned substrates include fiber substrates such as nonwoven fabrics, woven fabrics, and braided fabrics formed from polyester fibers, polyethylene fibers, nylon fibers, acrylonitrile fibers, polyurethane fibers, acetate fibers, rayon fibers, polylactic acid fibers, cotton, linen, silk, wool, glass fibers, carbon fibers, and their blended fibers; materials obtained by impregnating the aforementioned nonwoven fabrics with resins such as polyurethane resin; materials obtained by further providing a porous layer on the aforementioned nonwoven fabrics; resin substrates; rubber; glass; wood; metal, etc.

[0074] As a method for coating the above-mentioned waterborne polyurethane resin composition onto the above-mentioned substrate, examples include using a roller coater, a doctor blade coater, a comma coater, or an applicator.

[0075] As a method for drying the water mentioned above, one example is drying it at a temperature of 60 to 130°C for 30 seconds to 10 minutes.

[0076] Examples of the thickness of the film obtained by the above method include 5 to 1,000 μm.

[0077] Examples of products of the present invention include products having the above-mentioned film, specifically synthetic leather, artificial leather, etc.

[0078] [Example]

[0079] The present invention will now be described in detail using examples and comparative examples. It should be noted that the present invention is not limited to the examples listed below.

[0080] The number-average molecular weights of the polyol compounds, etc., used in the examples and comparative examples are values ​​determined by gel permeation chromatography (GPC) under the following conditions.

[0081] Measurement apparatus: High-speed GPC device (Tosoh Corporation "HLC-8220GPC")

[0082] Columns: The following columns manufactured by Tosoh Corporation are connected in series for use.

[0083] "TSKgel G5000" (7.8mm I.D. × 30cm) × 1 stick

[0084] "TSKgel G4000" (7.8mm I.D. × 30cm) × 1 stick

[0085] "TSKgel G3000" (7.8mm I.D. × 30cm) × 1 stick

[0086] "TSKgel G2000" (7.8mm I.D. × 30cm) × 1 stick

[0087] Detector: RI (Differential Refractometer)

[0088] Column temperature: 40℃

[0089] Eluent: Tetrahydrofuran (THF)

[0090] Flow rate: 1.0 mL / min

[0091] Injection volume: 100 μL (0.4% by mass tetrahydrofuran solution of sample concentration)

[0092] Standard test specimen: Calibration lines are made using the following standard polystyrene.

[0093] (Standard polystyrene)

[0094] TSKgel Standard Polystyrene A-500 manufactured by Tosoh Corporation

[0095] TSKgel Standard Polystyrene A-1000 manufactured by Tosoh Corporation

[0096] TSKgel Standard Polystyrene A-2500 manufactured by Tosoh Corporation

[0097] TSKgel Standard Polystyrene A-5000 manufactured by Tosoh Corporation

[0098] "TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation

[0099] TSKgel Standard Polystyrene F-2 manufactured by Tosoh Corporation

[0100] TSKgel Standard Polystyrene F-4 manufactured by Tosoh Corporation

[0101] TSKgel Standard Polystyrene F-10 manufactured by Tosoh Corporation

[0102] TSKgel Standard Polystyrene F-20 manufactured by Tosoh Corporation

[0103] TSKgel Standard Polystyrene F-40 manufactured by Tosoh Corporation

[0104] TSKgel Standard Polystyrene F-80 manufactured by Tosoh Corporation

[0105] TSKgel Standard Polystyrene F-128 manufactured by Tosoh Corporation

[0106] TSKgel Standard Polystyrene F-288 manufactured by Tosoh Corporation

[0107] TSKgel Standard Polystyrene F-550 manufactured by Tosoh Corporation

[0108] (Synthetic Example 1: Synthesis of Phosphoric Acid Modified Polyol (1))

[0109] In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen purging tube, 404 parts by mass of polypropylene glycol (hereinafter referred to as "PPG") (number average molecular weight: 750) and 100 parts by mass of anhydrous phosphoric acid were added under a nitrogen stream. After uniform mixing, the mixture was reacted at 80°C for about 10 hours to obtain a phosphoric acid modified polyol (1).

[0110] (Synthetic Example 2: Synthesis of Phosphoric Acid Modified Polyol (2))

[0111] In a four-necked flask equipped with a stirrer, reflux condenser, thermometer and nitrogen blowing tube, 375 parts by mass of PPG (number average molecular weight: 375) and 178 parts by mass of anhydrous phosphoric acid were added under a nitrogen flow. After uniform mixing, the mixture was reacted at 80°C for about 10 hours to obtain phosphoric acid modified polyol (2).

[0112] (Example 1: Preparation of waterborne polyurethane resin composition (1))

[0113] In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen purging tube, 360 parts by mass of polycarbonate diol (using 1,6-hexanediol as a raw material, number average molecular weight: 2,000 or less, referred to as "polycarbonate diol (1)"), 40 parts by mass of the phosphoric acid modified polyol (1) obtained in Synthesis Example 1, and 400 parts by mass of acetone were added under a nitrogen stream and stirred thoroughly. After stirring and mixing, 85 parts by mass of dicyclohexylmethane diisocyanate and 0.03 parts by mass of bismuth carboxylate were added, and the reaction was carried out at 55°C for about 8 hours, thereby obtaining an acetone solution of a polyurethane prepolymer with isocyanate groups at the molecular ends. Next, 18 parts by mass of triethylamine were added to the acetone solution of the obtained polyurethane prepolymer to neutralize the carboxyl groups in the above polyurethane prepolymer, 750 parts by mass of deionized water were added, and then 7.0 parts by mass of piperazine were added and the reaction was carried out. After the reaction was completed, acetone was removed by distillation under reduced pressure, thereby obtaining an aqueous polyurethane resin composition (1). The non-volatile component of the aqueous polyurethane resin composition (1) was 48% by mass.

[0114] (Example 2: Preparation of waterborne polyurethane resin composition (2))

[0115] In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen purging tube, 300 parts by mass of polycarbonate diol (1), 100 parts by mass of phosphoric acid modified polyol (1), and 400 parts by mass of acetone were added under a nitrogen stream and stirred thoroughly. After stirring and mixing, 105 parts by mass of dicyclohexylmethane diisocyanate and 0.03 parts by mass of bismuth carboxylate were added, and the reaction was carried out at 55°C for about 8 hours, thereby obtaining an acetone solution of a polyurethane prepolymer with isocyanate groups at the molecular ends. Next, 42 parts by mass of triethylamine were added to the acetone solution of the obtained polyurethane prepolymer to neutralize the carboxyl groups in the above polyurethane prepolymer, and then 850 parts by mass of deionized water were added. Next, 8.2 parts by mass of piperazine were added and the reaction was carried out. After the reaction was completed, acetone was removed by distillation under reduced pressure, thereby obtaining an aqueous polyurethane resin composition (2). The non-volatile component of this aqueous polyurethane resin composition (2) was 42 by mass.

[0116] (Example 3: Preparation of waterborne polyurethane resin composition (3))

[0117] In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen purging tube, 360 parts by mass of polycarbonate diol (1), 40 parts by mass of phosphoric acid modified polyol (1), and 400 parts by mass of acetone were added under a nitrogen stream and stirred thoroughly. After stirring and mixing, 55 parts by mass of hexamethylene diisocyanate, 72 parts by mass of isophorone diisocyanate, and 0.03 parts by mass of bismuth carboxylate were added, and the reaction was carried out at 55°C for about 8 hours, thereby obtaining an acetone solution of a polyurethane prepolymer with isocyanate groups at the molecular ends. Next, 71 parts by mass of 10% sodium hydroxide aqueous solution was added to the acetone solution of the obtained polyurethane prepolymer to neutralize the carboxyl groups in the above polyurethane prepolymer, and then 750 parts by mass of deionized water was added. Next, 7.0 parts by mass of piperazine was added and the reaction was carried out. After the reaction was completed, acetone was removed by distillation under reduced pressure, thereby obtaining an aqueous polyurethane resin composition (3). The non-volatile component of this aqueous polyurethane resin composition (3) was 45 by mass.

[0118] (Example 4: Preparation of waterborne polyurethane resin composition (4))

[0119] In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen purging tube, 320 parts by mass of polycarbonate diol (1), 80 parts by mass of phosphoric acid modified polyol (2), and 500 parts by mass of acetone were added under a nitrogen stream and stirred thoroughly. After stirring and mixing, 115 parts by mass of dicyclohexylmethane diisocyanate and 0.03 parts by mass of bismuth carboxylate were added, and the reaction was carried out at 55°C for about 8 hours, thereby obtaining an acetone solution of a polyurethane prepolymer with isocyanate groups at the molecular ends. Next, 36 parts by mass of triethylamine were added to the acetone solution of the obtained polyurethane prepolymer to neutralize the carboxyl groups in the above polyurethane prepolymer, and then 950 parts by mass of deionized water were added. Next, 9.6 parts by mass of piperazine were added and the reaction was carried out. After the reaction was completed, acetone was removed by distillation under reduced pressure, thereby obtaining an aqueous polyurethane resin composition (4). The non-volatile component of this aqueous polyurethane resin composition (4) was 49% by mass.

[0120] (Example 5: Preparation of waterborne polyurethane resin composition (5))

[0121] In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen purging tube, 388 parts by mass of polycarbonate diol (1), 12 parts by mass of phosphoric acid modified polyol (1), and 370 parts by mass of acetone were added under a nitrogen stream and stirred thoroughly. After stirring and mixing, 72 parts by mass of dicyclohexylmethane diisocyanate and 0.03 parts by mass of bismuth carboxylate were added, and the reaction was carried out at 55°C for about 8 hours to obtain an acetone solution of a polyurethane prepolymer with isocyanate groups at the molecular ends. Next, 10 parts by mass of triethylamine were added to the acetone solution of the obtained polyurethane prepolymer to neutralize the carboxyl groups in the polyurethane prepolymer, and then 630 parts by mass of deionized water were added. Next, 6.0 parts by mass of piperazine were added and the reaction was carried out. After the reaction was completed, acetone was removed by distillation under reduced pressure to obtain an aqueous polyurethane resin composition (5). The non-volatile component of this aqueous polyurethane resin composition (5) was 54 parts by mass.

[0122] (Example 6: Preparation of waterborne polyurethane resin composition (6))

[0123] In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen purging tube, 160 parts by mass of polycarbonate diol (1), 240 parts by mass of phosphoric acid modified polyol (1), and 500 parts by mass of acetone were added under a nitrogen stream and stirred thoroughly. After stirring and mixing, 160 parts by mass of dicyclohexylmethane diisocyanate and 0.03 parts by mass of bismuth carboxylate were added, and the reaction was carried out at 55°C for about 8 hours, thereby obtaining an acetone solution of a polyurethane prepolymer with isocyanate groups at the molecular ends. Next, 84 parts by mass of triethylamine were added to the acetone solution of the obtained polyurethane prepolymer to neutralize the carboxyl groups in the above polyurethane prepolymer, and then 1,000 parts by mass of deionized water were added. Next, 12.0 parts by mass of piperazine were added and the reaction was carried out. After the reaction was completed, acetone was removed by distillation under reduced pressure, thereby obtaining an aqueous polyurethane resin composition (6). The non-volatile component of this aqueous polyurethane resin composition (6) was 37 by mass.

[0124] (Comparative Example 1: Preparation of waterborne polyurethane resin composition (R1))

[0125] In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen purging tube, 380 parts by mass of polycarbonate diol (1), 20 parts by mass of dimethylolpropionic acid (hereinafter referred to as "DMPA"), and 370 parts by mass of acetone were added under a nitrogen stream and stirred thoroughly. After stirring and mixing, 90 parts by mass of dicyclohexylmethane diisocyanate and 0.03 parts by mass of bismuth carboxylate were added, and the reaction was carried out at 55°C for about 10 hours, thereby obtaining an acetone solution of a polyurethane prepolymer with isocyanate groups at the molecular ends. Next, 19 parts by mass of triethylamine were added to the acetone solution of the obtained polyurethane prepolymer to neutralize the carboxyl groups in the above polyurethane prepolymer, 630 parts by mass of deionized water were added, and then 7.0 parts by mass of piperazine were added and the reaction was carried out. After the reaction was completed, the acetone was removed by distillation under reduced pressure, thereby obtaining an aqueous polyurethane resin composition (R1). The non-volatile component of this aqueous polyurethane resin composition (R1) was 37 by mass.

[0126] (Comparative Example 2: Preparation of waterborne polyurethane resin composition (R2))

[0127] In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen purging tube, 320 parts by mass of polycarbonate diol (1), 80 parts by mass of polyethylene glycol (hereinafter referred to as "PEG") (number average molecular weight: 1,000), and 400 parts by mass of acetone were added under a nitrogen stream and stirred thoroughly. After stirring and mixing, 100 parts by mass of dicyclohexylmethane diisocyanate and 0.03 parts by mass of bismuth carboxylate were added, and the reaction was carried out at 55°C for about 8 hours, thereby obtaining an acetone solution of a polyurethane prepolymer with isocyanate groups at the molecular ends. Next, 900 parts by mass of deionized water were added to the acetone solution of the obtained polyurethane prepolymer, followed by 8.0 parts by mass of piperazine, and the reaction was carried out. After the reaction was completed, the acetone was removed by distillation under reduced pressure, thereby obtaining an aqueous polyurethane resin composition (R2). The non-volatile component of this aqueous polyurethane resin composition (R2) was 32% by mass.

[0128] The following evaluation was conducted using the aqueous polyurethane resin compositions (1) to (6) and (R1) to (R2) obtained in the above examples and comparative examples.

[0129] [Preparation of aqueous polyurethane resin composition compound]

[0130] A compound liquid of the waterborne polyurethane resin composition was prepared by combining 100 parts by weight of the waterborne polyurethane resin composition obtained in the above examples and comparative examples with 0.1 parts by weight of leveling agent (BYK-3455 manufactured by BYK), 0.3 parts by weight of defoamer (BYK-093 manufactured by BYK), and 0.2 parts by weight of thickener (Borchi Gel 0626 manufactured by Borchers).

[0131] [Preparation of the test plate]

[0132] A waterborne polyurethane resin composition was coated onto the surface of a 55% by mass aluminum-zinc alloy plated steel sheet without surface treatment, such that the film thickness upon drying was approximately 10 μm. The sheet was then heated at 110°C for 5 minutes, thereby producing a test panel formed from a component having a waterborne polyurethane resin layer laminated on the surface of the aforementioned steel sheet.

[0133] [Evaluation method for substrate adhesion]

[0134] Using the above test plate, the coating was divided into 5mm squares, and the peeling performance using tape was evaluated according to the following criteria.

[0135] A: The coating is normal.

[0136] B: Very little (less than 5% of the area) floated up in the coating.

[0137] C: A small amount of floating was observed in the coating (more than 5% but less than 60% of the area).

[0138] D: A large amount (over 60% of the area) of bubbling was observed in the coating.

[0139] [Durability Evaluation Methods]

[0140] After heating the test plate at 120°C for 200 hours, the coating was divided into 5mm squares, and the peeling performance using tape was evaluated according to the following criteria.

[0141] A: The coating is normal.

[0142] B: Very little (less than 5% of the area) floated up in the coating.

[0143] C: A small amount of floating was observed in the coating (more than 5% but less than 60% of the area).

[0144] D: A large amount (over 60% of the area) of bubbling was observed in the coating.

[0145] The evaluation results of the aqueous polyurethane resin compositions (1) to (6) and (R1) to (R2) obtained in the above examples and comparative examples are shown in Table 1.

[0146] [Table 1]

[0147]

Claims

1. A waterborne polyurethane resin composition, characterized in that, It contains polyurethane resin (A) and an aqueous medium (B). The polyurethane resin (A) uses polyol compound (a1) and polyisocyanate compound (a2) as necessary reaction raw materials. The polyol compound (a1) contains polycarbonate diol (a1-1) and phosphoric acid modified polyol (a1-2).

2. The waterborne polyurethane resin composition according to claim 1, wherein, The mass ratio of the polycarbonate diol (a1-1) to the phosphoric acid modified polyol (a1-2), i.e., (a1-1) / (a1-2), is in the range of 50 / 50 to 95 / 5.

3. The waterborne polyurethane resin composition according to claim 1, wherein, The phosphoric acid modified polyol (a1-2) uses trifunctional polypropylene glycol as an essential raw material and has a structure in which at least one of the three hydroxyl groups of the polypropylene glycol is phosphorylated.

4. The aqueous polyurethane resin composition according to claim 1, wherein, The polyurethane resin (A) further contains a neutralizing agent as a raw material, the neutralizing agent comprising an organic amine.

5. The aqueous polyurethane resin composition according to claim 1, wherein, The polyurethane resin (A) contains a salt composed of phosphoric acid and organic amine as a hydrophilic component.

6. A membrane, characterized in that, It is formed from the aqueous polyurethane resin composition according to any one of claims 1 to 5.

7. An article characterized in that, It has the membrane as described in claim 6.

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