Urethane resins, resin compositions, coatings, and articles

Abstract

The present invention provides a urethane resin that can contribute to the development of excellent water repellency, a resin composition containing the urethane resin, a film formed by the resin composition, and an article having the film. [Solution] A urethane resin is used that uses a polydimethylsiloxane compound having a hydroxyl group or an amino group and an isocyanate compound as essential reaction raw materials, characterized in that the number average molecular weight of the polydimethylsiloxane compound is 5000 or less.

Description

Technical Field

[0001] The present invention relates to urethane resins, resin compositions, films, and articles.

Background Art

[0002] Urethane resin compositions generally have good adhesion to substrates and can form flexible coating films, so they are used in various applications such as coating agents and adhesives.

[0003] Among them, due to their mechanical strength and good texture, they are widely used in the production of synthetic leather (including artificial leather).

[0004] In the above synthetic leather, fluorine-based auxiliaries are used to impart water repellency. However, with the PFAS regulations, the substitution with non-fluorine materials is underway. As materials showing water repellency, silicon compounds such as organic silicon compounds and polydimethylsiloxane compounds having siloxane bonds (silicone, silsesquioxane, etc.) after fluorine compounds are widely known. There have been studies to achieve the expression of water repellency by making a silicone-modified urethane resin in which a silicone compound is bonded to the main urethane resin or by adding a silicone compound to an existing urethane resin (see, for example, Patent Documents 1 to 3). However, when a silicone compound is directly bonded to the main urethane resin for the expression of water repellency, the resin physical properties change, so the development of a new resin is required, which is not general-purpose. Also, silicone compounds that can be bonded to urethane are expensive, and there are problems from the perspective of economy. Further, the method of adding a silicone compound to a urethane resin to express water repellency is a preferable method that can be used generally without impairing the physical properties of existing urethane resins. However, silicone compounds have poor compatibility with urethane resins and urethane resin solutions. When a film is formed by blending a silicone compound into a urethane resin solution, the silicone compound does not disperse uniformly in the urethane resin, resulting in problems such as the failure to express water repellency.

[0005] Therefore, there was a need for a material that had excellent compatibility with urethane resin and urethane resin solutions, and that contributed to the development of even better water repellency. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-014790 [Patent Document 2] Japanese Patent Publication No. 2015-44983 [Patent Document 3] Japanese Patent Publication No. 2016-30763 [Overview of the project] [Problems that the invention aims to solve]

[0007] The problem that the present invention aims to solve is to provide a urethane resin that can contribute to the development of excellent water repellency, a urethane resin composition containing the urethane resin, a resin composition containing the urethane resin composition, a film formed by the resin composition, and an article having the film. [Means for solving the problem]

[0008] The inventors of the present invention conducted diligent research to solve the above problems and found that the above problems can be solved by using a urethane resin that uses a specific polydimethylsiloxane compound and an isocyanate compound as essential reaction raw materials, thereby completing the present invention.

[0009] In other words, the present invention relates to a urethane resin comprising a polydimethylsiloxane compound having a hydroxyl group or an amino group and an isocyanate compound as essential reaction raw materials, wherein the number average molecular weight of the polydimethylsiloxane compound is 5000 or less; a resin composition containing the urethane resin; a film formed by the resin composition; and an article having the film.

[0010] The present invention provides the following embodiments. [1] A polydimethylsiloxane compound having a hydroxyl group or an amino group, A urethane resin that uses an isocyanate compound as an essential reaction raw material, A urethane resin characterized in that the number-average molecular weight of the polydimethylsiloxane compound is 5000 or less. [2] The urethane resin according to [1], wherein the polydimethylsiloxane compound has a hydroxyl group or an amino group at one end. [3] The urethane resin according to [1] or [2], wherein the polydimethylsiloxane content in the urethane resin is 10% by mass or more. [4] The urethane resin according to any one of [1] to [3] above, wherein the ratio of the number of moles of hydroxyl groups or amino groups in the polydimethylsiloxane compound to the number of moles of isocyanate groups in the isocyanate compound [(number of moles of hydroxyl groups or amino groups in the polydimethylsiloxane compound) / (number of moles of isocyanate groups in the isocyanate compound)] is in the range of 1 / 10 to 5 / 7. [5] The urethane resin according to any one of [1] to [4] above, wherein the urethane resin is a solvent-soluble resin. [6] A urethane resin composition characterized by containing the urethane resin described in any of [1] to [5] above and an organic solvent. [7] A resin composition characterized by containing the urethane resin composition described in [6] above and a urethane resin composition other than the urethane resin composition described in [6] above. [8] A resin composition characterized by containing a urethane resin described in any of [1] to [5] above and a urethane resin composition other than the urethane resin composition described in [6] above. [9] A resin composition characterized in that the amount of urethane resin used is in the range of 0.01 to 10 parts by mass per 100 parts by mass of solid content of a urethane resin composition other than the urethane resin composition described in [6] above.

[10] A film characterized by being formed by any of the resin compositions described in [7] to [9] above.

[11] An article having the coating described in

[11] above. [Effects of the Invention]

[0011] The urethane resin of the present invention contributes to the development of excellent water repellency and can therefore be suitably used in synthetic leather, breathable clothing, breathable films, polishing pads, and coating agents. [Modes for carrying out the invention]

[0012] The urethane resin of the present invention uses a polydimethylsiloxane compound having hydroxyl groups or amino groups and an isocyanate compound as essential reaction raw materials, characterized in that the number average molecular weight of the polydimethylsiloxane compound is 5000 or less.

[0013] The urethane resin used is one that has a polydimethylsiloxane compound having a hydroxyl group or an amino group and an isocyanate compound as essential raw materials.

[0014] Examples of commercially available polydimethylsiloxane compounds having a hydroxyl group or an amino group include, for example, JNC Corporation's "Silaplane® FM-0411P", "Silaplane® FM-0421", "Silaplane® FM-0425", "Silaplane® FM-DA11", "Silaplane® FM-DA21", and "Silaplane® FM-DA26", Shin-Etsu Chemical Co., Ltd.'s Shin-Etsu Silicone "X-22-170BX", "X-22-170DX", "X-22-176DX", "X-22-176GX-A", "X-22-4039", and "X-22-4015", which are polydimethylsiloxane compounds having a hydroxyl group at one end, and JNC Corporation's "Silaplane® FM- Examples include polydimethylsiloxane compounds having hydroxyl groups at both ends, such as "4411", "Cylaprene® FM-4421", "Cylaprene® FM-4425", Shin-Etsu Silicone "X-21-5841" and "KF-9701" manufactured by Shin-Etsu Chemical Co., Ltd., and polydimethylsiloxanes having amino groups at both ends, such as "Cylaprene® FM-3311", "Cylaprene® FM-3321", and "Cylaprene® FM-3325" manufactured by JNC Corporation, and Shin-Etsu Silicone "PAM-E", "KF-8010", "X-22-161-A", "X-22-161B", "KF-8012", "KF-8008", "X-22-1660B-3", and "X-22-9409" manufactured by Shin-Etsu Chemical Co., Ltd. Furthermore, as the polydimethylsiloxane compound having a hydroxyl group or an amino group, a polydimethylsiloxane compound having an amino group at one end can also be used. These polydimethylsiloxane compounds having a hydroxyl group or an amino group can be used individually or in combination of two or more types.

[0015] The number average molecular weight of the polydimethylsiloxane compound is 5000 or less. Since a urethane resin that can contribute to the development of water repellency of a film composed of the resin composition can be obtained, the range of 100 to 4000 is preferable, and the range of 300 to 3000 is more preferable. In the present invention, the number average molecular weight of the polydimethylsiloxane compound indicates a value measured by the gel permeation chromatography (GPC) method under the conditions described in the examples.

[0016] The amount of the polydimethylsiloxane compound used is preferably in the range of 10 to 80% by mass, more preferably in the range of 30 to 70% by mass, and even more preferably in the range of 40 to 60% by mass in the total mass of the raw materials of the urethane resin, since a urethane resin that can contribute to the development of water repellency of a film composed of the resin composition can be obtained.

[0017] Examples of the isocyanate compound include aromatic polyisocyanates such as phenylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, polymethylene polyphenyl polyisocyanate, carbodiimidized diphenylmethane polyisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, dimer acid diisocyanate, norbornene diisocyanate; and alicyclic diisocyanates such as norbornane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate. These polyisocyanates can be used alone or in combination of two or more.

[0018] Also, as the isocyanate compound, a urethane compound having an isocyanate group can be used.

[0019] The amount of the isocyanate compound used is preferably in the range of 1 to 60% by mass, more preferably in the range of 1 to 30% by mass, and still more preferably in the range of 1 to 10% by mass in the total mass of the raw materials of the urethane resin, since a urethane resin that can contribute to the expression of water repellency of the film made of the resin composition can be obtained.

[0020] The ratio [(the number of moles of the hydroxyl group or amino group of the polydimethylsiloxane compound) / (the number of moles of the isocyanate group of the isocyanate compound)] is preferably in the range of 1 / 10 to 5 / 7, and more preferably in the range of 1 / 6 to 4 / 6, since a urethane resin that can contribute to the expression of water repellency of the film made of the resin composition can be obtained.

[0021] The urethane resin of the present invention can, if necessary, use a polyol compound as a raw material in addition to the polydimethylsiloxane compound and the isocyanate compound.

[0022] Examples of the polyol compound include polyester polyol, polyether polyol, polycarbonate polyol, polybutadiene polyol, etc. These polyol compounds can be used alone or in combination of two or more.

[0023] Examples of the polyester polyol include those obtained by subjecting a polyvalent carboxylic acid and a polyhydric alcohol to an esterification reaction.

[0024] Examples of the polycarboxylic acids include aromatic dicarboxylic acids or their esters, such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid; and aliphatic dicarboxylic acids or their esters, such as succinic acid, glutaric acid, adipic acid, maleic acid, pimelic acid, suberic acid, azelaic acid, itaconic acid, sebacic acid, chlorendic acid, 1,2,4-butane-tricarboxylic acid, decanedicarboxylic acid, cyclohexanedicarboxylic acid, dimer acid, and fumaric acid. These polycarboxylic acids or their esters can be used individually or in combination of two or more.

[0025] Examples of the aforementioned polyhydric alcohols include aromatic diols such as benzenedimethanol, toluenedimethanol, and xylenediethanol; and aliphatic polyols such as ethylene glycol, propylene glycol, 1,3-propylenediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, and neopentyl glycol ethylene glycol. These polyhydric alcohols can be used individually or in combination of two or more.

[0026] In the esterification reaction for producing the polyester polyol, it is preferable to use an esterification catalyst 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 titanium tetraisopropoxide, titanium tetrabutoxide, titanium oxyacetylacetonate, dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, tin octanoate, 2-ethylhexanotin, zinc acetylacetonate, zirconium tetrachloride, zirconium tetrachloride tetrahydrofuran complex, hafnium tetrachloride, hafnium tetrachloride tetrahydrofuran complex, germanium oxide, and tetraethoxygermanium. These esterification catalysts can be used individually or in combination of two or more.

[0027] 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 individually or in combination of two or more.

[0028] Examples of the polycarbonate polyols include polycarbonate polyols obtained by reacting a carbonate ester and / or phosgene with a diol compound.

[0029] Examples of the aforementioned carbonate esters include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, and propylene carbonate. These carbonate esters can be used individually or in combination of two or more.

[0030] Examples of the aforementioned diol compounds include aliphatic diol compounds such as 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, neopentyl glycol, 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; and alicyclic diol compounds such as 1,4-cyclohexanedimethanol and 1,3-cyclohexanedimethanol. These diol compounds can be used individually or in combination of two or more.

[0031] Furthermore, as the polyol compound, a polyol compound obtained by esterifying a compound having a carboxyl group, or a polyol compound obtained by esterifying a compound having a sulfonic acid group with a polyhydric alcohol can also be used.

[0032] Examples of compounds having the carboxyl group include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and 2,2'-dimethylolvaleric acid.

[0033] Examples of compounds having the aforementioned sulfonic acid group include 5-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfophthalic acid, and 5[4-sulfophenoxy]isophthalic acid.

[0034] As the aforementioned polyhydric alcohol, for example, one similar to those exemplified as "polyhydric alcohol" above can be used.

[0035] The number-average molecular weight of the polyol compound is preferably in the range of 200 to 100,000, and more preferably in the range of 500 to 10,000, in order to obtain a urethane resin that can contribute to the water-repellent properties of the film made of the resin composition. In this invention, the number-average molecular weight of the polyol compound is the value measured by gel permeation chromatography (GPC) under the conditions described in the examples.

[0036] The amount of the polyol compound used is preferably in the range of 0 to 90% by mass, and more preferably in the range of 0 to 40% by mass, relative to the total mass of the urethane resin raw materials.

[0037] Furthermore, the urethane resin of the present invention may, if necessary, use a chain extender as a raw material in addition to the polydimethylsiloxane compound and the isocyanate compound.

[0038] Examples of the chain extenders include hydroxyl group-containing chain extenders such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, trimethylolpropane, and glycerin; ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, and 1,2-cyclohexane. Examples of chain extenders include those having amino groups such as diamines, 1,4-cyclohexanediamine, aminoethylethanolamine, hydrazine, diethylenetriamine, and triethylenetetramine; those having carboxyl groups such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and 2,2'-dimethylolvaleric acid; those having sulfonic acid groups such as 5-sulfoisophthalic acid, sulfotelephthalic acid, 4-sulfophthalic acid, and 5[4-sulfophenoxy]isophthalic acid; and diamines or polyamines containing alkali metal sulfonate groups such as alkali metal salts of N-(2-aminoethyl)-2-aminoethanesulfonic acid. These chain extenders can be used alone or in combination of two or more. Among these, chain extenders having hydroxyl groups are preferred because they yield a urethane resin capable of forming a film with excellent water repellency, and ethylene glycol, diethylene glycol, 1,3-propanediol, and 1,4-butanediol are more preferred.

[0039] Furthermore, the urethane resin of the present invention may, if necessary, use an organosilicon compound having a hydroxyl group or an amino group at one end, in addition to the polydimethylsiloxane compound and the isocyanate compound, as a raw material.

[0040] Examples of organosilicon compounds having a hydroxyl group or amino group at one end include 1,1,1,3,3,3-hexamethyldisilazane.

[0041] The method for producing the urethane resin of the present invention is not particularly limited and can be any method. For example, it may be produced by reacting all the reaction materials, including a polydimethylsiloxane compound having a hydroxyl group or an amino group and an isocyanate compound, all at once, or by reacting the reaction materials sequentially. These reactions are preferably carried out at a temperature of 50 to 100°C for 3 to 72 hours.

[0042] The polydimethylsiloxane content in the urethane resin of the present invention is preferably 10% by mass or more, and more preferably in the range of 35 to 60% by mass, as it can contribute to the water repellency of the film made of the resin composition.

[0043] The weight-average molecular weight of the urethane resin of the present invention is preferably in the range of 2,000 to 500,000, more preferably in the range of 4,000 to 300,000, and even more preferably in the range of 6,000 to 150,000, as it can contribute to the water-repellent properties of the film made from the resin composition. The weight-average molecular weight of the urethane resin is the value measured by gel permeation chromatography (GPC) under the conditions described in the examples.

[0044] The urethane resin of the present invention is a solvent-soluble resin that dissolves in organic solvents.

[0045] The urethane resin composition of the present invention contains the urethane resin of the present invention and an organic solvent.

[0046] Examples of the aforementioned organic solvents include ketone compounds such as acetone and methyl ethyl ketone; ether compounds such as tetrahydrofuran and dioxane; acetic acid ester compounds such as ethyl acetate and butyl acetate; nitrile compounds such as acetonitrile; amide compounds such as dimethylformamide and N-methylpyrrolidone; and alcohol compounds such as methanol, ethanol, isopropyl alcohol, isobutanol, sec-butanol, and tertiary butanol. These organic solvents can be used individually or in combination of two or more.

[0047] The resin composition of the present invention contains the urethane resin composition of the present invention and a urethane resin composition other than the urethane resin composition of the present invention (hereinafter referred to as "other urethane resin composition").

[0048] Furthermore, the resin composition of the present invention may contain the urethane resin of the present invention and the other urethane resin composition mentioned above.

[0049] In the resin composition of the present invention, the amount of urethane resin used is preferably in the range of 0.01 to 20 parts by mass, more preferably in the range of 0.01 to 10 parts by mass, and even more preferably in the range of 0.01 to 5 parts by mass, relative to 100 parts by mass of solid content of the other urethane resin composition.

[0050] The resin composition of the present invention may also contain other additives as needed.

[0051] Examples of the aforementioned other additives include emulsifiers, thickeners, urethane catalysts, fillers, flame retardants, leveling agents, and anti-blocking agents. These additives can be used individually or in combination of two or more types.

[0052] Examples of the emulsifiers include nonionic emulsifiers such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene sorbitol tetraoleate, and polyoxyethylene-polyoxypropylene copolymer; anionic emulsifiers such as fatty acid salts such as sodium oleate, alkyl sulfate esters, alkylbenzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, polyoxyethylene alkyl sulfates, sodium alkanesulfonates, and sodium alkyldiphenyl ethersulfonates; and cationic emulsifiers such as alkylamine salts, alkyltrimethylammonium salts, and alkyldimethylbenzylammonium salts. These emulsifiers can be used alone or in combination of two or more.

[0053] Examples of the aforementioned thickening agents include association-type and acid-based thickening agents.

[0054] Examples of the urethane catalyst include organotin-based, bismuth-based, and amine-based catalysts.

[0055] Examples of the filler include calcium carbonate and silica.

[0056] Examples of the aforementioned flame retardants include phosphorus-based flame retardants.

[0057] Examples of the leveling agent include silicone-based leveling agents.

[0058] Examples of the aforementioned blocking inhibitors include acrylics, cellulose esters, and the like.

[0059] The coating of the present invention is made of the aforementioned resin composition.

[0060] Methods for forming the aforementioned film include, for example, applying the resin composition of the present invention onto a substrate and then heating and drying it in a dryer.

[0061] Examples of the aforementioned base material include nonwoven fabrics, woven fabrics, knitted fabrics, and other fiber base materials made from polyester fibers, polyethylene fibers, nylon fibers, acrylic fibers, polyurethane fibers, acetate fibers, rayon fibers, polylactic acid fibers, cotton, linen, silk, wool, fiberglass, carbon fibers, and blends thereof; nonwoven fabrics impregnated with resins such as polyurethane resin; nonwoven fabrics further provided with a porous layer; resin base materials; rubber; glass; wood; metal, and the like.

[0062] Methods for applying the resin composition to the substrate include, for example, using a roll coater, knife coater, comma coater, applicator, etc.

[0063] The thickness of the film obtained by the above method can be, for example, 5 to 1,000 μm.

[0064] Articles of the present invention include those having the aforementioned coating, and specifically include synthetic leather, artificial leather, breathable clothing, breathable film, polishing pad, coating agent, and the like. [Examples]

[0065] The present invention will be specifically described below with reference to examples and comparative examples. However, the present invention is not limited to the examples listed below.

[0066] The number-average molecular weights of the polyol compounds and polydimethylsiloxane compounds used in the examples and comparative examples, and the weight-average molecular weight of the urethane resin, are shown as values ​​measured by gel permeation chromatography (GPC) under the following conditions.

[0067] Measurement device: High-speed GPC device (HLC-8220GPC manufactured by Tosoh Corporation) Columns: The following columns manufactured by Tosoh Corporation were used, connected in series. "TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mmI.D. x 30cm) x 1 Detector: RI (Differential Refractometer) Column temperature: 40℃ Eluent: Tetrahydrofuran (THF) Flow rate: 1.0mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass) Standard samples: Calibration curves were prepared using the following standard polystyrene samples.

[0068] (Standard polystyrene) TSKgel Standard Polystyrene A-500, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-1000, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-2500, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-5000, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-1, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-2, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-4, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-10, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-20, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-40, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-80, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-128, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-288, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-550, manufactured by Tosoh Corporation.

[0069] (Example 1: Synthesis of urethane resin (1)) 100 parts by mass of an adduct obtained by reacting tolylene diisocyanate with trimethylolpropane under conditions where the molar ratio [isocyanate groups / hydroxyl groups] of isocyanate groups in tolylene diisocyanate to hydroxyl groups in trimethylolpropane was 2.0, and 42 parts by mass of a polyester polyol with a number average molecular weight of 550 obtained by reacting 1,4-butanediol, neopentyl glycol, and adipic acid were mixed with dimethylformamide and reacted under a nitrogen stream at 80°C with stirring for 3 hours to obtain a dimethylformamide solution of a urethane prepolymer having isocyanate groups at the molecular ends.

[0070] Next, the dimethylformamide solution of the urethane prepolymer was mixed with a polydimethylsiloxane compound having a hydroxyl group at one end ("Cylaplane® FM-0411P" manufactured by JNC Corporation) and 304 parts by mass of polydimethylsiloxane-containing end-ended alcohol (number average molecular weight Mn ≈ 1,000). The mixture was reacted at 70°C for 8 hours, and then the reaction was stopped with ethanol to obtain urethane resin (1).

[0071] (Example 2: Synthesis of urethane resin (2)) A urethane resin (2) was obtained by mixing 46 parts by mass of diphenylmethane diisocyanate with 50 parts by mass of a polyester polyol having a number average molecular weight of 550 obtained by reacting 1,4-butanediol with neopentyl glycol and adipic acid, and 91 parts by mass of a polydimethylsiloxane compound having a hydroxyl group at one end ("Cylaprene® FM-DA11" manufactured by JNC Corporation) and a polydimethylsiloxane-containing dialcohol with a number average molecular weight of Mn ≈ 1,000. The mixture was reacted at 70°C for 8 hours, and then the reaction was stopped with ethanol.

[0072] (Example 3: Synthesis of urethane resin (3)) 47 parts by mass of diphenylmethane diisocyanate and 52 parts by mass of polyester polyol with a number average molecular weight of 550 obtained by reacting 1,4-butanediol, neopentyl glycol, and adipic acid were mixed with dimethylformamide and reacted under a nitrogen stream at 80°C with stirring for 8 hours to obtain a dimethylformamide solution of a urethane prepolymer having isocyanate groups at the molecular ends.

[0073] Next, the dimethylformamide solution of the urethane prepolymer was mixed with a polydimethylsiloxane compound having a hydroxyl group at one end ("Cylaplane® FM-0411P" manufactured by JNC Corporation) and 187 parts by mass of polydimethylsiloxane-containing end-ended alcohol (number average molecular weight Mn ≈ 1,000). The mixture was reacted at 70°C for 8 hours, and then the reaction was stopped with ethanol to obtain urethane resin (3).

[0074] (Example 4: Synthesis of urethane resin (4)) A urethane resin (4) was obtained by mixing 46 parts by mass of diphenylmethane diisocyanate with 50 parts by mass of a polyester polyol having a number average molecular weight of 550 obtained by reacting 1,4-butanediol, neopentyl glycol and adipic acid, and 91 parts by mass of a polydimethylsiloxane compound having hydroxyl groups at both ends ("Cylaprene® FM-4411" manufactured by JNC Corporation) and a polydimethylsiloxane-containing dialcohol (number average molecular weight Mn ≈ 1,000). The mixture was reacted at 70°C for 8 hours, and then the reaction was stopped with ethanol.

[0075] (Comparative Example 1: Synthesis of urethane resin (R1)) 100 parts by mass of an adduct obtained by reacting tolylene diisocyanate with trimethylolpropane under conditions where the molar ratio [isocyanate groups / hydroxyl groups] of isocyanate groups in tolylene diisocyanate to hydroxyl groups in trimethylolpropane was 2.0, and 42 parts by mass of a polyester polyol with a number average molecular weight of 550 obtained by reacting 1,4-butanediol, neopentyl glycol, and adipic acid were mixed with dimethylformamide and reacted under a nitrogen stream at 80°C with stirring for 8 hours to obtain a dimethylformamide solution of a urethane prepolymer having isocyanate groups at the molecular ends.

[0076] Next, the dimethylformamide solution of the urethane prepolymer was mixed with a polydimethylsiloxane compound having a hydroxyl group at one end ("Cylaprene F® M-0425" manufactured by JNC Corporation) and 3045 parts by mass of polydimethylsiloxane-containing end-ended alcohol (number average molecular weight Mn ≈ 10,000), and reacted at 70°C for 3 hours. However, solid matter precipitated, and a urethane resin soluble in organic solvents could not be obtained.

[0077] (Example 5: Preparation of resin composition (1)) Resin composition (1) was obtained by mixing 100 parts by mass of the solid content of "CRISVON(registered trademark) 8166NC" manufactured by DIC Corporation with the urethane resin (1) obtained in Example 1 so that the solid content was 1 part by mass.

[0078] (Example 6: Preparation of lipid composition (2)) Resin composition (2) was obtained by mixing 100 parts by mass of the solid content of "CRISVON(registered trademark) 8166NC" manufactured by DIC Corporation with the urethane resin (2) obtained in Example 2, so that the solid content was 1 part by mass.

[0079] (Example 7: Preparation of resin composition (3)) Resin composition (3) was obtained by mixing 100 parts by mass of the solid content of "CRISVON(registered trademark) 8166NC" manufactured by DIC Corporation with the urethane resin (3) obtained in Example 3, so that the solid content was 1 part by mass.

[0080] (Example 8: Preparation of resin composition (4)) Resin composition (4) was obtained by mixing 100 parts by mass of the solid content of "CRISVON(registered trademark) 8166NC" manufactured by DIC Corporation with the urethane resin (4) obtained in Example 4, so that the solid content was 1 part by mass.

[0081] (Comparative Example 2: Resin composition (R2)) DIC Corporation's "CRISVON(registered trademark) 8166NC" was used as the resin composition (R2).

[0082] (Comparative Example 3: Preparation of resin composition (R3)) A resin composition (R3) was obtained by mixing 100 parts by mass of solids of "CRISVON(registered trademark) 8166NC" manufactured by DIC Corporation with 1 part by mass of "DOWSIL BY-16-201" manufactured by DOW Corporation.

[0083] (Comparative Example 4: Preparation of Resin Composition (R4)) A resin composition (R4) was obtained by mixing 100 parts by mass of the solid content of "CRISVON® 8166NC" manufactured by DIC Corporation with 1 part by mass of a polydimethylsiloxane compound having a hydroxyl group at one end ("Cylaprene® FM-0411P" manufactured by JNC Corporation).

[0084] The following evaluations were performed using the resin compositions (1) to (4) and (R2) to (R4) obtained in the above examples and comparative examples.

[0085] [Preparation of test specimens] The resin compositions (1) to (4) and (R2) to (R4) obtained in the above examples and comparative examples were each applied to flat release paper so that the film thickness after drying was 40 μm, and dried at 70°C for 2 minutes and at 120°C for 2 minutes to obtain thin layer films (test pieces).

[0086] [Method for evaluating water repellency] The contact angle of the aforementioned test specimen was measured, and the water repellency was evaluated according to the following criteria. The contact angle was measured using a contact angle meter (DropMaster, manufactured by Kyowa Interface Science Co., Ltd., with FAMAS analysis software), and distilled water (DW) was used as the dropping solution. The dropping volume was 1 μL, and the contact angle was measured 1 second and 10 seconds after the measurement solution was dropped onto the film.

[0087] A: The water contact angle after 10 seconds was 99° or greater. B: The water contact angle after 10 seconds was between 98° and 99°. C: The water contact angle after 10 seconds was between 95° and 98°. D: The water contact angle after 10 seconds was less than 95°.

[0088] The evaluation results for the resin compositions (1) to (4) and (R2) to (R4) obtained in the above examples and comparative examples are shown in the table.

[0089] [Table 1]

Claims

1. A polydimethylsiloxane compound having a hydroxyl group or an amino group, A urethane resin that uses an isocyanate compound as an essential reaction raw material, A urethane resin characterized in that the number-average molecular weight of the polydimethylsiloxane compound is 5,000 or less.

2. The urethane resin according to claim 1, wherein the polydimethylsiloxane compound has a hydroxyl group or an amino group at one end.

3. The urethane resin according to claim 1, wherein the polydimethylsiloxane content in the urethane resin is 10% by mass or more.

4. The urethane resin according to claim 1, wherein the ratio of the number of moles of hydroxyl groups or amino groups in the polydimethylsiloxane compound to the number of moles of isocyanate groups in the isocyanate compound [(number of moles of hydroxyl groups or amino groups in the polydimethylsiloxane compound) / (number of moles of isocyanate groups in the isocyanate compound)] is in the range of 1 / 10 to 5 / 7.

5. The urethane resin according to claim 1, wherein the urethane resin is a solvent-soluble resin.

6. A urethane resin composition characterized by containing a urethane resin according to any one of claims 1 to 5 and an organic solvent.

7. A resin composition characterized by containing the urethane resin composition described in claim 6 and a urethane resin composition other than the urethane resin composition described in claim 6.

8. A resin composition characterized by containing a urethane resin according to any one of claims 1 to 5 and a urethane resin composition other than the urethane resin composition according to claim 6.

9. The resin composition according to claim 8, wherein the amount of urethane resin used is in the range of 0.01 to 20 parts by mass per 100 parts by mass of solid content of a urethane resin composition other than the urethane resin composition according to claim 6.

10. A film characterized by being formed by the resin composition according to any one of claims 7 to 9.

11. An article characterized by having the coating described in claim 10.

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