Moisture-curable polyurethane resin composition, adhesive, and laminate

Abstract

An object of the present invention is to provide a moisture-curable polyurethane resin composition that has excellent adhesion to water-repellent fibers and the like and has an excellent texture. [Solution] The present invention provides a moisture-curable polyurethane hot-melt resin composition containing an isocyanate group-containing urethane prepolymer (A) having a melt viscosity of more than 1,000 mPa·s and not more than 50,000 mPa·s at 120°C, and an isocyanate group-containing urethane prepolymer (B) having a melt viscosity of 100 mPa·s or more and not more than 1,000 mPa·s at 120°C. The urethane prepolymer (B) is preferably made from polypropylene glycol and / or polyethylene glycol having a number-average molecular weight of 400 to 10,000.

Description

[Technical Field]

[0001] The present invention relates to a moisture-curable polyurethane resin composition, an adhesive, and a laminate. [Background technology]

[0002] Moisture-permeable, waterproof functional clothing, which has both moisture permeability and waterproofness, is a structure in which a moisture-permeable film is bonded to a fabric with an adhesive, and urethane adhesives are commonly used as the adhesive because of their good adhesion to both the moisture-permeable film and the fabric. Furthermore, among these urethane adhesives, the use of solvent-free, moisture-curable polyurethane resin compositions is gradually increasing due to recent global regulations on solvent emissions and residual solvents (see, for example, Patent Document 1).

[0003] On the other hand, the fabrics used are becoming lighter and more functional, with finer denier and improved water repellency, which poses the issue of reduced adhesion between pre-treated water-repellent fabrics and adhesives. However, no current moisture-curing polyurethane resin compositions have been found to exhibit particularly high adhesion to ultra-water-repellent fabrics. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-202608 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide a moisture-curable polyurethane resin composition that has excellent adhesion to water-repellent fabrics and the like, and that has excellent texture. [Means for solving the problem]

[0006] The present invention provides a moisture-curable polyurethane hot-melt resin composition containing an isocyanate group-containing urethane prepolymer (A) having a melt viscosity at 100°C of more than 1,000 mPa·s and not more than 50,000 mPa·s, and an isocyanate group-containing urethane prepolymer (B) having a melt viscosity at 100°C of 100 mPa·s or more and 1,000 mPa·s or less.

[0007] The present invention also provides an adhesive containing the moisture-curable polyurethane resin composition. Furthermore, the present invention also provides a laminate having at least a substrate (i) and a cured product of the moisture-curable polyurethane resin composition. [Effects of the Invention]

[0008] The moisture-curable polyurethane hot-melt resin composition of the present invention is solvent-free and is an environmentally friendly material. Furthermore, the moisture-curable polyurethane hot-melt resin composition of the present invention has excellent adhesion to various fabrics, including water-repellent fabrics, and also has excellent texture. DETAILED DESCRIPTION OF THE INVENTION

[0009] The moisture-curable polyurethane hot-melt resin composition used in the present invention contains a specific urethane prepolymer (A) and a specific urethane prepolymer (B).

[0010] The urethane prepolymer (A) is an essential component for ensuring basic physical properties and adhesiveness, and has a melt viscosity at 100°C of more than 1,000 mPa·s and not more than 50,000 mPa·s, and contains an isocyanate group.

[0011] As the urethane prepolymer (A), for example, a reaction product of a polyol and a polyisocyanate can be used.

[0012] Examples of the polyol that can be used include polyester polyols, polycaprolactone polyols, polyether polyols, polycarbonate polyols, polyacrylic polyols, and polybutadiene polyols. These polyols may be used alone or in combination of two or more. Among these, one or more polyols selected from the group consisting of polyester polyols, polycaprolactone polyols, polycarbonate polyols, and polyether polyols are preferred because they provide even better mechanical strength, adhesiveness, and the like.

[0013] As the polyester polyol, for example, a reaction product of a polybasic acid and a compound having two or more hydroxyl groups can be used.

[0014] Examples of the polybasic acid that can be used include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedicarboxylic acid, glutaric acid, pimelic acid, suberic acid, dimer acid, sebacic acid, undecanedicarboxylic acid, hexahydroterephthalic acid, and phthalic acid compounds (phthalic acid, phthalic anhydride, isophthalic acid, and terephthalic acid). These polybasic acids may be used alone or in combination of two or more. Among these, one or more polybasic acids selected from the group consisting of adipic acid, phthalic acid compounds, dodecanedicarboxylic acid, and sebacic acid are preferred because they provide even better adhesiveness and mechanical strength.

[0015] Examples of the reaction products with the compound having two or more hydroxyl groups include ethylene glycol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, pentanediol, 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, hexanediol, neopentyl glycol, hexamethylene glycol, glycerin, trimethylolpropane, bisphenol A, bisphenol F, and alkylene oxide adducts thereof, 2-methyl-1,3-propanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2 ,4-trimethyl-1,3-pentanediol, 1,2-butanediol, 1,3-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-isopropyl-1,4-butanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-1,6-hexanediol, 3,5-heptanediol, 2-methyl-1,8-octanediol, neopentyl glycol, trimethylolpropane, etc. These compounds may be used alone or in combination of two or more.

[0016] In order to further enhance the effects of the present invention, the following combinations of raw materials for the polyester polyol are preferred. A combination of a reaction product of a compound having two or more hydroxyl groups of C2 or more carbon atoms with a polybasic acid having an aromatic ring and / or a polybasic acid having C6 or more carbon atoms is preferred. Specific examples of compounds having two or more hydroxyl groups of C2 or more carbon atoms include ethylene glycol, neopentyl glycol, 1,4-butanediol, hexanediol, and 3-methyl-1,5-pentanediol. Examples of polybasic acids having an aromatic ring and / or polybasic acids having C6 or more carbon atoms include phthalic acid compounds, adipic acid, sebacic acid, azelaic acid, and dodecanedicarboxylic acid.

[0017] The number average molecular weight of the polyester polyol is preferably 500 to 10,000, more preferably 700 to 5,000, in terms of obtaining even better mechanical strength, adhesiveness, etc. The number average molecular weight of the polyester polyol is a value measured by gel permeation chromatography (GPC).

[0018] When the polyester polyol is used, the amount used is, for example, 20 to 100% by mass, and preferably 30 to 80% by mass, of the polyol.

[0019] As the polycaprolactone polyol, for example, a reaction product of the compound having two or more groups and ε-caprolactone can be used.

[0020] The number average molecular weight of the polycaprolactone polyol is preferably 500 to 200,000, more preferably 1,000 to 100,000, in terms of obtaining even better adhesive properties, etc. The number average molecular weight of the polycaprolactone polyol is a value measured by gel permeation chromatography (GPC).

[0021] When the polycaprolactone polyol is used, the amount used is, for example, 20 to 80% by mass, and preferably 30 to 70% by mass, of the polyol, in order to obtain even better adhesive properties.

[0022] As the polycarbonate polyol, for example, a reaction product of the compound having two or more hydroxyl groups with a carbonate ester and / or phosgene can be used.

[0023] Examples of the carbonate ester that can be used include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, propylene carbonate, etc. These compounds may be used alone or in combination of two or more.

[0024] The number average molecular weight of the polycarbonate diol is preferably 500 to 10,000, more preferably 700 to 4,000, in terms of obtaining even better adhesive properties, etc. The number average molecular weight of the polycarbonate polyol is a value measured by gel permeation chromatography (GPC).

[0025] When the polycarbonate diol is used, the amount used is, for example, 20 to 80% by mass, and preferably 30 to 80% by mass, of the polyol, in order to obtain even better adhesive properties.

[0026] Examples of the polyether polyol that can be used include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. These may be used alone or in combination of two or more. Among these, polypropylene glycol and / or polytetramethylene glycol are preferred because they provide even more excellent adhesive properties, mechanical strength, and the like.

[0027] The number average molecular weight of the polyether polyol is preferably 500 to 10,000, more preferably 700 to 5,000, in terms of obtaining even better adhesive properties, mechanical strength, etc. The number average molecular weight of the polyether polyol is a value measured by gel permeation chromatography (GPC).

[0028] When the polyether polyol is used, the amount used is, for example, 20 to 80% by mass, and preferably 30 to 80% by mass, of the polyol, in order to obtain even better mechanical strength.

[0029] Examples of the polyisocyanate include aromatic polyisocyanates such as polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate isocyanate, xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate; and aliphatic or alicyclic polyisocyanates such as hexamethylene diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and tetramethylxylylene diisocyanate. These polyisocyanates may be used alone or in combination of two or more. Among these, aromatic polyisocyanates are preferred because of their superior reactivity and adhesiveness to fabrics, and diphenylmethane diisocyanate is more preferred.

[0030] The amount of the polyisocyanate used is preferably 5 to 40 mass %, more preferably 10 to 30 mass %, based on the total mass of the raw materials constituting the urethane prepolymer (A).

[0031] The hot-melt urethane prepolymer (A) is obtained by reacting the polyol with the polyisocyanate, and has isocyanate groups that can react with moisture present in the air or in the substrate to which the moisture-curable polyurethane hot-melt resin composition is applied to form a crosslinked structure.

[0032] The urethane prepolymer (A) can be produced, for example, by adding the polyisocyanate to a reaction vessel containing the polyol and reacting them under conditions such that the isocyanate groups of the polyisocyanate are in excess relative to the hydroxyl groups of the polyol.

[0033] When producing the urethane prepolymer (A), the equivalent ratio of the isocyanate groups of the polyisocyanate to the hydroxyl groups of the polyol (isocyanate groups / hydroxyl groups) is preferably 1.1 to 5, and more preferably 1.5 to 3.0, in order to obtain even better adhesion to fabrics.

[0034] The isocyanate group content (hereinafter abbreviated as "NCO%) of the urethane prepolymer (A) obtained by the above method is preferably in the range of 1.7 to 5.0, more preferably 1.8 to 3.0, in order to obtain even better adhesiveness. The NCO% of the hot-melt urethane prepolymer (A) is a value measured by potentiometric titration in accordance with JIS K1603-1:2007.

[0035] The melt viscosity of the urethane prepolymer (A) at 100°C is preferably more than 1,000 mPa·s and not more than 50,000 mPa·s, and more preferably 1,000 to 10,000 mPa·s, in order to ensure basic physical properties and adhesiveness. The method for measuring the melt viscosity of the urethane prepolymer (A) at 100°C will be described in detail in the Examples below.

[0036] Next, the urethane prepolymer (B) will be described.

[0037] The urethane prepolymer (B) has a melt viscosity at 100°C of 100 mPa·s or more and 1,000 mPa·s or less, and contains an isocyanate group. It has been found that the inclusion of the urethane prepolymer (B) improves permeability into water-repellent fabrics, resulting in a significant improvement in adhesiveness. A more preferred range for the melt viscosity at 100°C is 200 to 800 mPa·s. The method for measuring the melt viscosity of the urethane prepolymer (B) at 100°C will be described in detail in the Examples below.

[0038] The urethane prepolymer (B) can be, for example, a reaction product of a polyol and a polyisocyanate, and the same polyols and polyisocyanates as those usable as the raw materials for the urethane prepolymer (A) can be used. Among these, it is preferable to use a polyether polyol as the polyol, and polypropylene glycol and / or polyethylene glycol are preferred, in order to further improve the permeability and adhesiveness to water-repellent fabrics.

[0039] The number-average molecular weight of the polyether polyol is preferably 400 to 10,000, more preferably 400 to 3,000, in order to obtain even better penetration and adhesion to fabrics. The number-average molecular weight of the polyether polyol is a value measured by gel permeation chromatography (GPC).

[0040] The hot-melt urethane prepolymer (B) is obtained by reacting the polyol with the polyisocyanate, and has isocyanate groups that can react with moisture present in the air or in the substrate to which the moisture-curable polyurethane hot-melt resin composition is applied to form a crosslinked structure.

[0041] The urethane prepolymer (B) can be produced, for example, by adding the polyisocyanate to a reaction vessel containing the polyol and reacting them under conditions such that the isocyanate groups of the polyisocyanate are in excess relative to the hydroxyl groups of the polyol.

[0042] When producing the urethane prepolymer (B), the equivalent ratio of the isocyanate groups of the polyisocyanate to the hydroxyl groups of the polyol (isocyanate groups / hydroxyl groups) is preferably 1.1 to 5.0, more preferably 1.2 to 3.0, in order to obtain even better adhesion to fabrics.

[0043] The isocyanate group content ("NCO%") of the urethane prepolymer (B) obtained by the above method is preferably in the range of 1.5 to 8.0, more preferably 1.8 to 6.0, in order to obtain even better adhesiveness. The NCO% of the hot-melt urethane prepolymer (B) is a value measured by potentiometric titration in accordance with JIS K1603-1:2007.

[0044] The mass ratio of the urethane prepolymer (A) to the urethane prepolymer (B) [(A) / (B)] is preferably 50 / 50 to 90 / 10, in order to further improve the effects of the present invention.

[0045] The moisture-curable polyurethane hot-melt resin composition used in the present invention contains the urethane prepolymers (A) and (B) as essential components, but may contain other additives as needed.

[0046] Examples of the other additives that can be used include light resistance stabilizers, curing catalysts, tackifiers, plasticizers, stabilizers, fillers, dyes, pigments, fluorescent brighteners, silane coupling agents, waxes, thermoplastic resins, etc. These additives may be used alone or in combination of two or more.

[0047] As described above, the moisture-curable polyurethane hot-melt resin composition of the present invention is solvent-free and is an environmentally friendly material. Furthermore, the moisture-curable polyurethane hot-melt resin composition of the present invention has excellent adhesion to various fabrics, including water-repellent fabrics, and also has excellent texture.

[0048] Next, the laminate of the present invention will be described.

[0049] The laminate of the present invention comprises at least a substrate (i) and a cured product of the moisture-curable polyurethane hot-melt resin composition.

[0050] Examples of the fabric (i) that can be used include fiber substrates such as nonwoven fabrics, woven fabrics, and knitted fabrics made from polyester fibers, polyethylene fibers, nylon fibers, acrylic fibers, polyurethane fibers, acetate fibers, rayon fibers, polylactic acid fibers, cotton, hemp, silk, wool, glass fibers, carbon fibers, and blends thereof; nonwoven fabrics impregnated with resins such as polyurethane resins; nonwoven fabrics further provided with a porous layer; and resin substrates.

[0051] Furthermore, in the present invention, the fabric (i) is the one that has been subjected to a water-repellent treatment (hereinafter abbreviated as "water-repellent fabric") and still exhibits excellent adhesiveness. Note that, in the present invention, the "water-repellent" of the water-repellent fabric means that the surface free energy obtained by the following calculation is 50 mJ / m 2 Show that:

[0052] The contact angles of the test liquids (water and diiodomethane) on the fabric (i) were measured using a contact angle meter ("DM500" manufactured by Kyowa Interface Science Co., Ltd.) Based on these results, the surface free energy of the fabric (i) was calculated using the following formula (1). (1+cosA)·γL / 2=(γsd·γLd)1 / 2+(γsp·γLp)1 / 2

[0053] A: Contact angle of the test liquid on the fabric (i) γL: Surface tension of the liquid to be measured γLd: Dispersion force component of the surface free energy of the liquid to be measured γLp: Polar component of the surface free energy of the liquid to be measured γsd: Dispersion force component of the surface free energy of fabric (i) γsp; polar component of the surface free energy of substrate (i)

[0054] Examples of methods for applying the moisture-curable polyurethane hot-melt resin composition include methods using a roll coater, knife coater, spray coater, gravure roll coater, comma coater, T-die coater, applicator, dispenser, etc.

[0055] After the moisture-curable polyurethane hot-melt resin composition is applied, it can be dried and cured by a known method.

[0056] The thickness of the cured product of the moisture-curable urethane hot-melt resin composition is, for example, in the range of 5 to 300 μm.

[0057] When the moisture-curable polyurethane hot-melt resin composition of the present invention is used as an adhesive for moisture-permeable, waterproof functional clothing, the moisture-curable polyurethane hot-melt resin composition is preferably applied intermittently using a gravure roll coater or a dispenser, and then the fabric (i) is bonded to a known moisture-permeable film. In such a case, the thickness of the cured product of the moisture-curable polyurethane hot-melt resin composition is, for example, in the range of 5 to 50 μm.

[0058] A mesh fabric may be further laminated onto the moisture-permeable film by intermittently applying a moisture-curable polyurethane hot-melt resin composition. [Example]

[0059] The present invention will be described in more detail below using examples.

[0060] [Synthesis Example 1] A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with 20 parts by mass of polypropylene glycol (number average molecular weight 1,000), 10 parts by mass of polypropylene glycol (number average molecular weight 2,000), 15 parts by mass of polyester polyol (number average molecular weight 2,000) which is a reaction product of hexanediol and orthophthalic acid, 20 parts by mass of polyester polyol (number average molecular weight 1,000) which is a reaction product of neopentyl glycol and orthophthalic acid, and 5 parts by mass of polyester polyol (number average molecular weight 3,500) which is a reaction product of hexanediol and dodecanedicarboxylic acid, and the mixture was dried under reduced pressure at 110°C to dehydrate it until the water content was 0.05% by mass or less. After cooling to 60°C, 23.4 parts by mass of diphenylmethane diisocyanate (hereinafter abbreviated as "MDI") was added, and the temperature was raised to 110°C. The reaction was continued for 2 hours until the isocyanate group content became constant, yielding urethane prepolymer (A1). The melt viscosity of the urethane prepolymer (A1) at 100°C was 2,000 mPa s.

[0061] [Synthesis Example 2] A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with 20 parts by weight of polypropylene glycol (number average molecular weight 1,000), 15 parts by weight of polypropylene glycol (number average molecular weight 2,000), 25 parts by weight of polyester polyol (number average molecular weight 2,000) which is a reaction product of hexanediol and orthophthalic acid, 20 parts by weight of polyester polyol (number average molecular weight 1,000) which is a reaction product of neopentyl glycol and orthophthalic acid, and 15 parts by weight of polyester polyol (number average molecular weight 3,500) which is a reaction product of hexanediol and sebacic acid, and dried under reduced pressure at 110 ° C. to dehydrate until the water content was 0.05% by weight or less. Next, after cooling to 60 ° C, 28 parts by weight of MDI was added, the temperature was raised to 110 ° C., and the mixture was reacted for 2 hours until the isocyanate group content became constant, thereby obtaining a urethane prepolymer (A2). The melt viscosity of the urethane prepolymer (A2) at 100° C. was 2,500 mPa·s.

[0062] [Synthesis Example 3] A four-neck flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser was charged with 50 parts by weight of polyester polyol (number-average molecular weight 2,000), a reaction product of neopentyl glycol and orthophthalic acid, and 50 parts by weight of polycaprolactone polyol (number-average molecular weight 2,000). The mixture was dried under reduced pressure at 110°C to remove water until the water content was 0.05% by weight or less. After cooling to 60°C, 19.6 parts by weight of MDI was added, the mixture was heated to 110°C, and reacted for 2 hours until the isocyanate group content reached a constant value, yielding urethane prepolymer (A3). The melt viscosity of the urethane prepolymer (A3) at 100°C was 4,800 mPa·s.

[0063] [Synthesis Example 4] A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with 15 parts by weight of polyester polyol (number average molecular weight 2,000) which is a reaction product of hexanediol and orthophthalic acid, 20 parts by weight of polyester polyol (number average molecular weight 1,000) which is a reaction product of neopentyl glycol and orthophthalic acid, 5 parts by weight of polyester polyol (number average molecular weight 3,500) which is a reaction product of hexanediol and dodecanedicarboxylic acid, 20 parts by weight of polytetramethylene glycol (number average molecular weight 1,000), and 10 parts by weight of polytetramethylene glycol (number average molecular weight 2,000). The mixture was dried under reduced pressure at 110 ° C. and dehydrated until the water content was 0.05% by weight or less. Next, after cooling to 60 ° C., 23.4 parts by weight of MDI was added, the temperature was raised to 110 ° C., and the mixture was reacted for 2 hours until the isocyanate group content became constant, thereby obtaining a urethane prepolymer (A4). The melt viscosity of the urethane prepolymer (A4) at 100° C. was 3,500 mPa·s.

[0064] [Synthesis Example 5] A four-neck flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser was charged with 20 parts by weight of polyester polyol (number average molecular weight 2,000), a reaction product of hexanediol and orthophthalic acid, and 80 parts by weight of polyester polyol (number average molecular weight 3,500), a reaction product of ethylene glycol, adipic acid, orthophthalic acid, and terephthalic acid. The mixture was dried under reduced pressure at 110°C to dehydrate it to a water content of 0.05% by weight or less. After cooling to 60°C, 20 parts by weight of MDI was added, the mixture was heated to 110°C, and reacted for 2 hours until the isocyanate group content reached a constant value, yielding urethane prepolymer (A5). The melt viscosity of the urethane prepolymer (A5) at 100°C was 4,000 mPa·s.

[0065] [Synthesis Example 6] A four-neck flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser was charged with 20 parts by weight of polypropylene glycol (number average molecular weight 400), 50 parts by weight of polypropylene glycol (number average molecular weight 1,000), and 30 parts by weight of polypropylene glycol (number average molecular weight 2,000). The mixture was dried under reduced pressure at 110°C to remove water until the water content was 0.05% by weight or less. After cooling to 60°C, 54 parts by weight of MDI was added, the mixture was heated to 110°C, and reacted for 2 hours until the isocyanate group content reached a constant value, yielding urethane prepolymer (B1). The melt viscosity of the urethane prepolymer (B1) at 100°C was 350 mPa·s.

[0066] [Synthesis Example 7] A four-neck flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser was charged with 50 parts by weight of polypropylene glycol (number average molecular weight 400) and 25 parts by weight of polypropylene glycol (number average molecular weight 700). The mixture was dried under reduced pressure at 110°C and dehydrated until the water content was 0.05% by weight or less. After cooling to 60°C, 63 parts by weight of MDI was added, the mixture was heated to 110°C, and reacted for 2 hours until the isocyanate group content reached a constant value, yielding urethane prepolymer (B2). The melt viscosity of the urethane prepolymer (B2) at 100°C was 800 mPa·s.

[0067] [Synthesis Example 8] A four-neck flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser was charged with 50 parts by weight of polypropylene glycol (number average molecular weight 400) and 25 parts by weight of polypropylene glycol (number average molecular weight 2,000). The mixture was dried under reduced pressure at 110°C to remove water until the water content was 0.05% by weight or less. After cooling to 60°C, 55 parts by weight of MDI was added, and the mixture was heated to 110°C and reacted for 2 hours until the isocyanate group content reached a constant value, yielding urethane prepolymer (B3). The melt viscosity of the urethane prepolymer (B3) at 100°C was 500 mPa·s.

[0068] [Examples 1 to 9, Comparative Examples 1 to 6] As shown in Tables 1 to 3, urethane prepolymers (A) and (B) were blended (expressed in parts by mass) to obtain moisture-curable polyurethane hot-melt resin compositions.

[0069] [Method for measuring number average molecular weight] The number average molecular weights of the polyols used in the synthesis examples are values ​​measured by gel permeation chromatography (GPC) under the following conditions.

[0070] Measurement equipment: High-speed GPC equipment (Tosoh Corporation "HLC-8220GPC") Column: The following columns manufactured by Tosoh Corporation were connected in series and used. "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 (sample concentration 0.4% by mass in tetrahydrofuran solution) Standard sample: A calibration curve was prepared using the following standard polystyrene.

[0071] (standard polystyrene) Tosoh Corporation's "TSKgel Standard Polystyrene A-500" Tosoh Corporation's "TSKgel Standard Polystyrene A-1000" Tosoh Corporation's "TSKgel Standard Polystyrene A-2500" Tosoh Corporation's "TSKgel Standard Polystyrene A-5000" "TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation Tosoh Corporation's "TSKgel Standard Polystyrene F-2" Tosoh Corporation's "TSKgel Standard Polystyrene F-4" Tosoh Corporation's "TSKgel Standard Polystyrene F-10" Tosoh Corporation's "TSKgel Standard Polystyrene F-20" Tosoh Corporation's "TSKgel Standard Polystyrene F-40" Tosoh Corporation's "TSKgel Standard Polystyrene F-80" Tosoh Corporation's "TSKgel Standard Polystyrene F-128" Tosoh Corporation's "TSKgel Standard Polystyrene F-288" Tosoh Corporation's "TSKgel Standard Polystyrene F-550"

[0072] [Method for measuring melt viscosity at 100°C] The urethane prepolymer obtained in each synthesis example was melted at 100° C. for 1 hour, and then 1 ml of the sample was taken and the melt viscosity was measured using a cone-plate viscometer (40P cone, rotor rotation speed: 50 rpm).

[0073] [Method for evaluating adhesion to fabric] The moisture-curable polyurethane hot-melt resin compositions obtained in the examples and comparative examples were melted at 100°C and then coated with a gravure roll coater (coating amount: 17.5±5 g / m 2 ) was used to intermittently coat a moisture-permeable film (DIC Corporation's "Crisbon S-517" processed into a 15μm film), and water-repellent fabric 1 (polyester fabric (Japan Standards Association, weft / weft: 75D / 36f-FDY, basis weight: 71.8g / m²) treated with a water-repellent agent (Nicca Chemical Co., Ltd.'s "Neoseed NR-8800"), resulting in a water-repellent grade of 5; hereafter abbreviated as "Fabric 1") and water-repellent fabric 2 (polyester fabric (Japan Standards Association, weft / weft: 75D / 36f-FDY, basis weight: 71.8g / m²) treated with a water-repellent agent (Nicca Chemical Co., Ltd.'s "Neoseed NR-8800"), resulting in a water-repellent grade of 5; hereafter abbreviated as "Fabric 1") were used. 2 ) was treated with a water repellent (Neoseed "NR-7080" manufactured by Nicca Chemical Co., Ltd.) and had a water repellency of grade 5. Hereinafter abbreviated as "Fabric 2." ) was bonded to each of the fabrics and left for 24 hours in an atmosphere of 23°C and 50% humidity to obtain a processed fabric. Each of the processed fabrics obtained was cut into 1-inch widths, and the peel strength was measured using a Tensilon (Tensilon all-purpose machine "RTC-1210A" manufactured by Orientec Co., Ltd.) at a crosshead speed of 200 mm / min, and evaluated as follows. "T": 0.6 kgf / inch or more. "F": Less than 0.6 kgf / inch.

[0074] [How to evaluate texture] Each laminate obtained in the above [Method for evaluating adhesion to fabric] was cut into a piece 1 inch wide and 8 cm long, and using a precision universal testing machine (Shimadzu Corporation's "Autograph AG-1"), the test piece was folded in half and attached so that a 5 cm length of the folded part was rounded and protruding from the top of a clamping jig. A flat indenter was pressed into the piece at a test speed of 10 mm / min, and the stress at a displacement of 5 mm was measured and evaluated as follows. "T"; 100mN or less "F": Over 100mN

[0075] [Table 1]

[0076] [Table 2]

[0077] [Table 3]

[0078] It was found that the moisture-curable polyurethane hot-melt resin composition of the present invention has excellent adhesion to water-repellent fabrics and excellent texture.

[0079] On the other hand, Comparative Examples 1 and 3 to 6 were embodiments that did not contain the urethane prepolymer (B), but the adhesion to the water-repellent fabric was poor.

[0080] On the other hand, Comparative Example 2, which does not contain the urethane prepolymer (A), had poor adhesion to the water-repellent fabric and poor feel.

Claims

1. A moisture-curable polyurethane hot-melt resin composition comprising: a urethane prepolymer (A) having an isocyanate group and having a melt viscosity at 100°C of more than 1,000 mPa·s and not more than 50,000 mPa·s; and a urethane prepolymer (B) having an isocyanate group and having a melt viscosity at 100°C of 100 mPa·s or more and not more than 1,000 mPa·s.

2. 2. The moisture-curable polyurethane hot-melt resin composition according to claim 1, wherein the urethane prepolymer (B) is made from a polyether polyol.

3. 3. The moisture-curable polyurethane hot-melt resin composition according to claim 2, wherein the polyether polyol is polypropylene glycol and / or polyethylene glycol having a number average molecular weight of 400 to 10,000.

4. 2. The moisture-curable polyurethane hot-melt resin composition according to claim 1, wherein the urethane prepolymer (A) is made from one or more polyols selected from the group consisting of polyester polyols, polycaprolactone polyols, polycarbonate polyols, and polyether polyols.

5. The moisture-curable polyurethane hot melt resin composition according to claim 1, wherein the mass ratio [(A) / (B)] of the urethane prepolymer (A) to the urethane prepolymer (B) is 50 / 50 to 90 / 10.

6. An adhesive comprising the moisture-curable polyurethane hot-melt resin composition according to claim 1.

7. A laminate comprising at least a substrate (i) and a cured product of the moisture-curable polyurethane hot-melt resin composition according to claim 1.

8. 8. The laminate according to claim 7, wherein the fabric (i) is a water-repellent and / or non-water-repellent fabric.

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