Moisture-curable polyurethane hot-melt resin composition and laminate

Abstract

To provide a moisture-curable polyurethane hot-melt resin composition excellent in moisture-proof performance and adhesive strength.SOLUTION: The present invention provides a moisture-curable polyurethane hot-melt resin composition comprising: a urethane prepolymer (i) having isocyanate groups which is a reaction product of a polyol (A) and a polyisocyanate (B), the polyol (A) containing an alicyclic polyester polyol (a-1), an aliphatic polyester polyol (a-2) other than the alicyclic polyester polyol (a-1), and a polycaprolactone polyol (a-3); and an inorganic filler (ii). The present invention also provides a laminate including at least a cured product layer of the moisture-curable polyurethane hot-melt resin composition and an olefin sheet.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention provides a moisture-curable polyurethane hot-melt resin composition and a laminate. [Background technology]

[0002] In the field of building materials, decorative fixtures have traditionally been used to improve aesthetics and provide durability, with base materials such as wood, plywood, MDF (medium density fiberboard), particle board, etc., covered with decorative sheets having decorative colors or patterns on their surfaces. Moisture-curing urethane hot-melt resin compositions are used to bond the base materials and decorative sheets together (see, for example, Patent Document 1).

[0003] In recent years, decorative fixtures often have hollow cores to reduce weight and provide thermal insulation. This creates a temperature difference between the interior (especially the hollow portion) and exterior of the building component, which can lead to condensation in summer and winter. If condensation is absorbed into the decorative fixture, it can cause deformation, such as warping or swelling, due to differences in moisture absorption among the components that make up the decorative fixture. Therefore, the provision of a moisture-resistant layer inside the decorative fixture has been considered in order to prevent warping and swelling and improve durability.

[0004] Furthermore, in recent years, there has been a strong demand for adhesives with moisture-proof properties in order to reduce the number of moisture-proof sheets and sheet bonding processes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-11419 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the present invention is to provide a moisture-curable polyurethane hot-melt resin composition that has excellent moisture-proofing properties and adhesive strength. [Means for solving the problem]

[0007] The present invention provides a moisture-curable polyurethane hot-melt resin composition comprising: an alicyclic polyester polyol (a-1); an aliphatic polyester polyol (a-2) other than the alicyclic polyester polyol (a-1); a urethane prepolymer (i) having an isocyanate group, which is a reaction product of a polyol (A) including a polycaprolactone polyol (a-3) and a polyisocyanate (B); and an inorganic filler (ii).

[0008] The present invention also provides a laminate comprising at least a cured layer of the moisture-curable polyurethane hot-melt resin composition and an olefin sheet. [Effects of the Invention]

[0009] The moisture-curable polyurethane hot-melt resin composition of the present invention is excellent in moisture-proofing properties and adhesive strength. DETAILED DESCRIPTION OF THE INVENTION

[0010] The moisture-curable polyurethane hot-melt resin composition of the present invention contains an alicyclic polyester polyol (a-1), an aliphatic polyester polyol (a-2) other than the alicyclic polyester polyol (a-1), a polycaprolactone polyol (a-3), a polyol (A) including a polyisocyanate (B), a urethane prepolymer (i) having an isocyanate group, and an inorganic filler (ii).

[0011] The alicyclic polyester polyol (a-1) is an essential component for achieving excellent moisture-proofing properties and adhesive strength. Examples of the alicyclic polyester polyol (a-1) that can be used include a reaction product of an alicyclic polyol and an aliphatic polycarboxylic acid (or an acid derivative thereof), and a reaction product of an aliphatic polyol and an alicyclic polycarboxylic acid (or an acid derivative thereof).

[0012] Examples of the alicyclic polyol that can be used include cyclopentanediol, cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, and alkylene oxide adducts of these alicyclic polyols with ethylene oxide, propylene oxide, etc. These alicyclic polyols may be used alone or in combination of two or more.

[0013] Examples of the aliphatic polyol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, neopentyl glycol, 1, Examples of usable aliphatic polyols include 3-butanediol, 2,2-diethyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethylpropanediol, 3-methyl-1,5-pentanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2,4-diethyl-1,5-pentanediol, trimethylolethane, trimethylolpropane, pentaerythritol, and glycerin. These aliphatic polyols may be used alone or in combination of two or more.

[0014] Examples of the alicyclic polycarboxylic acid that can be used include cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, hydrogenated phthalic anhydride, etc. These alicyclic polycarboxylic acids may be used alone or in combination of two or more.

[0015] Examples of the aliphatic polycarboxylic acid that can be used include aliphatic polycarboxylic acids having 4 to 12 carbon atoms, such as succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedioic acid, dodecanedioic acid, eicosadioic acid, citraconic acid, itaconic acid, citraconic anhydride, and itaconic anhydride. These aliphatic polycarboxylic acids may be used alone or in combination of two or more.

[0016] The number average molecular weight of the alicyclic polyester polyol (a-1) is preferably in the range of 500 to 10,000, more preferably in the range of 800 to 5,000, from the viewpoint of obtaining even better moisture-proofing performance and adhesive strength. The number average molecular weight of the alicyclic polyester polyol (a-1) is a value measured by gel permeation chromatography (GPC) under the following conditions:

[0017] 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.

[0018] (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"

[0019] The amount of the alicyclic polyester polyol (a-1) used is preferably in the range of 20 to 80 mass % of the total of the raw materials constituting the urethane prepolymer (i), and more preferably in the range of 30 to 60 mass %, in order to obtain even better moisture-proof performance and adhesive strength.

[0020] The aliphatic polyester polyol (a-2) is other than the alicyclic polyester polyol (a-1), and a reaction product of a glycol and a polybasic acid can be used.

[0021] Examples of the glycol that can be used include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, and decanediol. These compounds may be used alone or in combination of two or more. Among these, it is preferable to use one or more compounds selected from the group consisting of butanediol, hexanediol, octanediol, and decanediol, in order to enhance crystallinity and further improve initial strength and peel strength.

[0022] Examples of the polybasic acid that can be used include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, and dodecanedioic acid. These polybasic acids may be used alone or in combination of two or more. Among these, polybasic acids having 8 to 20 carbon atoms are preferred because they can further improve moisture-proofing performance and adhesive strength.

[0023] The number average molecular weight of the aliphatic polyester polyol (a-2) is preferably in the range of 500 to 10,000, more preferably in the range of 1,000 to 8,000, from the viewpoint of further improving processability, moisture resistance, and adhesive strength. The method for measuring the number average molecular weight of the aliphatic polyester polyol (a-2) is the same as that for the alicyclic polyester polyol (a-1).

[0024] The amount of the aliphatic polyester polyol (a-2) used is preferably in the range of 5 to 45 mass % of the total of the raw materials constituting the urethane prepolymer (i), and more preferably in the range of 10 to 25 mass %, in order to obtain even better moisture-proof performance and adhesive strength.

[0025] The polycaprolactone polyol (a-3) is an essential component for obtaining excellent adhesive strength, and for example, a reaction product of the above-mentioned glycol and ε-caprolactone can be used.

[0026] The number average molecular weight of the polycaprolactone polyol (a-3) is preferably in the range of 5,000 to 200,000, more preferably in the range of 10,000 to 100,000, from the viewpoint of further improving the initial adhesive strength and the final adhesive strength. The method for measuring the number average molecular weight of the polycaprolactone polyol (a-3) is the same as that for the alicyclic polyester polyol (a-1).

[0027] The amount of the polycaprolactone polyol (a-2) used is preferably in the range of 1 to 15 mass % of the total of the raw materials constituting the urethane prepolymer (i), and more preferably in the range of 3 to 10 mass %, from the viewpoint of further improving the initial adhesive strength and the final adhesive strength.

[0028] The polyol (A) contains the alicyclic polyester polyol (a-1), the aliphatic polyester polyol (a-2), and the polycaprolactone polyol (a-3) as essential components, but may contain other polyols as necessary.

[0029] Examples of the other polyols that can be used include polyester polyols, polyether polyols, and polycarbonate polyols other than those listed in (a-1) to (a-3). These polyols may be used alone or in combination of two or more. Among these, when the moisture-curable polyurethane hot-melt resin composition of the present invention is used to produce decorative fixtures, it is preferable to use polyester polyol (a-4) made from a compound having two or more hydroxyl groups and a branched structure as the polyester polyol other than those listed in (a-1) to (a-3), in order to further improve adhesion to olefin sheets, which are known as decorative sheets and difficult-to-adhere substrates.

[0030] As the polyester polyol (a-4), for example, a reaction product of a compound having two or more hydroxyl groups and a branched structure, a polybasic acid, and, if necessary, other glycols can be used.

[0031] Examples of compounds having two or more hydroxyl groups and a branched structure include neopentyl glycol, 1,3-butanediol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2,2-diethylpropanediol, 3-methyl-1,5-pentanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2,4-diethyl-1,5-pentanediol, trimethylolethane, trimethylolpropane, pentaerythritol, and glycerin. These compounds may be used alone or in combination. Among these, one or more compounds selected from the group consisting of neopentyl glycol, 1,3-butanediol, 2-methyl-1,3-propanediol, and 3-methyl-1,5-pentanediol are preferred because they provide superior adhesive strength to olefin sheets.

[0032] The other glycols may be the same as those usable as raw materials for the aliphatic polyester polyol (a-2).The polybasic acids may be the same as those usable as raw materials for the aliphatic polyester polyol (a-2).

[0033] The amount of the compound having two or more hydroxyl groups and a branched structure used in the raw materials having hydroxyl groups that constitute the polyester polyol (a-4) is preferably in the range of 5 to 50 mass %, more preferably 10 to 30 mass %, in order to obtain even better adhesive strength to an olefin sheet.

[0034] The number average molecular weight of the polyester polyol (a-4) is preferably in the range of 500 to 10,000, more preferably in the range of 1,000 to 8,000, in order to obtain even better adhesive strength to an olefin sheet. The method for measuring the number average molecular weight of the polyester polyol (a-4) is the same as that for the alicyclic polyester polyol (a-1).

[0035] When the polyester polyol (a-4) is used, the amount used is preferably in the range of 5 to 30 mass %, more preferably 10 to 25 mass %, of the total amount of raw materials constituting the urethane prepolymer (i).

[0036] Examples of the polyisocyanate (B) 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, and diphenylmethane diisocyanate is more preferred, from the viewpoints of reactivity and peeling strength.

[0037] The urethane prepolymer (i) can be produced, for example, by adding the polyol (A) mixture dropwise to a reaction vessel containing the polyisocyanate (B), followed by heating, and reacting under conditions in which the isocyanate groups of the polyisocyanate (B) are in excess relative to the hydroxyl groups of the polyol (A).

[0038] When producing the urethane prepolymer (i), the equivalent ratio of the isocyanate groups in the polyisocyanate (B) to the hydroxyl groups in the polyol (A) (isocyanate groups / hydroxyl groups) is preferably in the range of 1.1 to 5, more preferably 3 to 4.5, in order to further improve the moisture-proof performance and adhesive strength.

[0039] The isocyanate group content (hereinafter abbreviated as "NCO%") of the urethane prepolymer (i) is preferably in the range of 2 to 10 mass%, more preferably in the range of 3 to 7 mass%, in order to further improve moisture-proof performance and adhesive strength. The NCO% of the urethane prepolymer (i) is a value measured by potentiometric titration in accordance with JIS K1603-1:2007.

[0040] The inorganic filler (ii) is an essential component for achieving excellent moisture-proofing performance. Examples of the inorganic filler that can be used include mica, glass flakes, glass fiber, talc, fluorine filler, calcium carbonate, silica, magnesium hydroxide, and aluminum hydroxide. These fillers may be used alone or in combination of two or more. Among these, mica is preferred because it suppresses moisture penetration through its labyrinth effect, thereby achieving even better moisture-proofing performance.

[0041] The average particle size of the mica is preferably in the range of 3 to 50 μm, more preferably 15 to 30 μm, in order to obtain even better moisture-proof performance. The average particle size of the mica is the volume average diameter measured by the laser diffraction / scattering method in accordance with JIS Z 8819-2:2001.

[0042] The aspect ratio of the mica is preferably at least 60, more preferably at least 120, in order to obtain even better moisture-proof performance. The aspect ratio of the mica is a value calculated as aspect ratio = L / a from the 50% average particle size (L) measured by a laser diffraction particle size distribution analyzer (LMS-30; manufactured by Seishin Co., Ltd.) and the average interplanar thickness (a) measured by a transmission electron microscope.

[0043] The amount of the inorganic filler (ii) used is preferably in the range of 5 to 70 parts by mass, more preferably 15 to 55 parts by mass, per 100 parts by mass of the urethane prepolymer (i), in order to obtain even better moisture-proof performance.

[0044] The moisture-curable polyurethane hot-melt resin composition of the present invention contains the urethane prepolymer (i) and the inorganic filler (ii) as essential components, and may contain other additives as needed.

[0045] Examples of the other additives that can be used include curing catalysts, antioxidants, 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.

[0046] As described above, the moisture-curable polyurethane hot-melt resin composition of the present invention is excellent in moisture-proofing performance and adhesive strength.

[0047] An example of a method for bonding adherends with the moisture-curable polyurethane hot-melt resin composition of the present invention is to apply the resin composition to the surface of a substrate and then bond the substrate to another substrate.

[0048] Examples of the substrate that can be used include fiber substrates, glass substrates, wood substrates, metal substrates, and plastic substrates.

[0049] Examples of methods for applying the moisture-curable polyurethane hot-melt resin composition to the substrate include methods in which the moisture-curable polyurethane hot-melt resin composition is melted at 100 to 140°C, and then coated with a coater such as a roll coater, spray coater, T-die coater, knife coater, or comma coater; a precision method such as a dispenser, inkjet printing, screen printing, or offset printing; or nozzle coating.

[0050] After the two substrates are bonded together, it is preferable to dry the adhesive and cure it by a known method, if necessary.

[0051] Furthermore, when the moisture-curable polyurethane hot-melt resin composition of the present invention is used to produce decorative fixtures, the decorative fixtures can be produced by laminating a substrate and a sheet or film such as those described below using the moisture-curable polyurethane hot-melt resin composition.

[0052] The substrate may be, for example, a wood substrate such as plywood, MDF (medium density fiberboard), or particle board, or a metal substrate such as aluminum or iron. The substrate may also have a complex shape such as a groove, a curved portion, or a reverse curved portion.

[0053] Examples of the sheet or film that can be used include sheets or films obtained using resins such as polyolefin, polyester, polyamide, polystyrene, polycarbonate, vinyl chloride, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and polypropylene, as well as paper, metal foil, and veneer. Among these, when a specific moisture-curable polyurethane hot-melt resin composition is used, the composition has excellent adhesion even to olefin sheets made of polyolefin, which are known to be difficult to adhere to.

[0054] The sheet or film may be generally called decorative paper, base paper for decorative laminates, decorative sheet, etc., and may have a plain or colorful decorative color or pattern on its surface. The back surface of the sheet or film may be treated with a primer such as a resin.

[0055] As a method for bonding the substrate and the sheet or the like using the moisture-curable polyurethane hot melt resin composition of the present invention, for example, the moisture-curable polyurethane hot melt resin composition is melted by heating in the range of 100 to 150°C, and applied to the substrate using a roll coater, spray coater, T-die coater, knife coater, or the like, and the sheet or the like is bonded to the coated surface; alternatively, the moisture-curable polyurethane hot melt resin composition is applied to the sheet or the like using a roll coater, or the like, and the substrate is bonded to the coated surface, and the composition is pressed to fit the shape of the substrate using a method such as roll press, flat press, or belt press. [Example]

[0056] The present invention will be described in more detail below using examples.

[0057] [Example 1] A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with 55 parts by mass of an alicyclic polyester polyol (a reaction product of 2,2-dimethyl-1,3-propanediol and hydrogenated phthalic anhydride, number average molecular weight: 2,200, hereinafter abbreviated as "alicyclic PEs"), 13 parts by mass of an aliphatic polyester polyol (a reaction product of 1,6-hexanediol and dodecanedioic acid, number average molecular weight: 3,500, hereinafter abbreviated as "HG / DDA"), 3 parts by mass of a polycaprolactone polyol (number average molecular weight: 80,000, hereinafter abbreviated as "PCL"), and 25 parts by mass of mica ("NCF-322" manufactured by Yamaguchi Mica Co., Ltd., average particle size: 27 μm, aspect ratio: 150, hereinafter abbreviated as "mica (1)"), and the mixture was dehydrated under reduced pressure until the water content was 0.05% by mass or less. Next, after cooling the temperature inside the preparation vessel to 70°C, 29 parts by mass of 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as "MDI") was added, the temperature was raised to 100°C, and the reaction was carried out for approximately 3 hours until the NCO content became constant, thereby obtaining a moisture-curable polyurethane hot-melt resin composition containing a urethane prepolymer having isocyanate groups and mica.

[0058] [Examples 2 to 5, Comparative Example 1] A moisture-curable polyurethane hot-melt resin composition was obtained in the same manner as in Example 1, except that the raw materials used were changed as shown in Tables 1-1.

[0059] [Method for evaluating moisture-proof performance] A release film made of polyethylene terephthalate was placed on a glass plate whose surface temperature was adjusted to 100°C. The moisture-curable polyurethane hot-melt resin compositions obtained in the Examples and Comparative Examples were heated to melt at 120°C, applied to the release film to a thickness of 100 μm, and aged for one week in an atmosphere at a temperature of 30°C and a relative humidity of 50%. Thereafter, the release film was peeled off to prepare a measurement sample. The moisture permeability of the measurement sample was measured using a moisture permeability cup method (JIS Z0208-B method, unit: g / m 2 The measurements were made based on the following criteria: "◎": Less than 4. "〇": 4 or more and less than 7 "×": 7 or more

[0060] [Method for evaluating adhesive strength] The moisture-curable polyurethane hot-melt resin compositions obtained in the examples and comparative examples were heated to 120°C to melt them, and applied to MDF in an amount of 80 g / m using a roll coater set at 120°C. 2 Next, another MDF was placed on the applied adhesive layer and bonded together. The test piece was aged for one week in an atmosphere of 30°C and 50% relative humidity, after which a force was applied to the MDF of the test piece in a 90° direction, and the peel strength per unit area was measured and evaluated as follows: "〇": 1.7MPa or more "×": Less than 1.7 MPa

[0061] [Method for evaluating adhesion to olefin sheet] The moisture-curable polyurethane hot-melt resin compositions obtained in Examples 4 and 5 and Comparative Example 1 were heated to 120°C to melt and applied to a primer-treated olefin decorative sheet to a thickness of 50 μm, and then MDF was placed on the adhesive layer and bonded. The test specimens were aged for one week in an atmosphere of 30°C and 50% relative humidity, after which the sheets of the test specimens were peeled in a 180° direction and the peel strength per 25 mm width was measured and evaluated as follows: "〇";20N / 25mm or more "×": Less than 20N / 25mm

[0062] [Table 1]

[0063] [Table 2]

[0064] The abbreviations in Table 1 are explained below. "Branched PEs": reaction product of diethylene glycol, neopentyl glycol, 1,6-hexanediol, and adipic acid, number average molecular weight: 2,000 "Mica (2)": "A-21S" manufactured by Yamaguchi Mica Co., Ltd., average particle size: 23 μm, aspect ratio: 70

[0065] It was found that the moisture-curable polyurethane hot-melt resin composition of the present invention has excellent moisture-proofing properties and adhesive strength. Furthermore, it was found that Examples 4 to 7 also have excellent adhesiveness to an olefin sheet.

[0066] On the other hand, Comparative Example 1, which is an embodiment in which the inorganic filler (ii) is not used, was poor in moisture-proofing performance and adhesion to the olefin sheet.

Claims

1. The composition contains an alicyclic polyester polyol (a-1), an aliphatic polyester polyol (a-2) other than the alicyclic polyester polyol (a-1), a polycaprolactone polyol (a-3), a polyol (A) including a polyisocyanate (B), a urethane prepolymer (i) having an isocyanate group, and an inorganic filler (ii), The amount of the inorganic filler (ii) used is in the range of 5 to 70 parts by mass per 100 parts by mass of the urethane prepolymer (i).

2. The moisture-curable polyurethane hot melt resin composition according to claim 1, wherein the aliphatic polyester polyol (a-2) is made from a polybasic acid having 8 to 20 carbon atoms.

3. 3. The moisture-curable polyurethane hot-melt resin composition according to claim 1, wherein the inorganic filler (ii) is mica.

4. 4. The moisture-curable polyurethane hot-melt resin composition according to claim 3, wherein the mica has an aspect ratio of 60 or more.

5. The moisture-curable polyurethane hot-melt resin composition according to any one of claims 1 to 4, wherein the polyol (A) further contains a polyester polyol (a-4) made from a compound having two or more hydroxyl groups and a branched structure other than the alicyclic polyester polyol (a-1) and the aliphatic polyester polyol (a-2).

6. A laminate comprising at least a cured layer of the moisture-curable polyurethane hot melt resin composition according to any one of claims 1 to 5, and an olefin sheet.

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