Laminates and upholstery materials for vehicle seats

Abstract

To provide a laminate having excellent blocking resistance and production efficiency without using the frame lamination method or base fabric.SOLUTION: A laminate has a polyurethane foam and a cured product of a moisture-curable polyurethane hot-melt resin composition, but does not have base fabric. The moisture-curable polyurethane hot-melt resin composition has a setting time of less than 60 seconds. There is also provided a skin material for vehicular sheets that has the polyurethane foam further having a skin layer thereon. The moisture-curable polyurethane hot-melt resin composition preferably includes, as the polyol material, an aromatic polyester polyol.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a laminate and a surface material for vehicle seats.

Background Art

[0002] Laminated sheets such as synthetic leather and artificial leather are used for the surface of furniture and vehicle seats, and a buffer layer such as polyurethane foam (urethane foam (PUF)) is generally provided to exhibit cushioning properties.

[0003] Conventionally, the bonding of synthetic leather and PUF is carried out by flame lamination, and the melted PUF by flame is bonded to the surface member such as synthetic leather (see, for example, Patent Document 1). Further, generally, a back base cloth is bonded to the back surface of the PUF as a sliding material to improve workability during sewing or when attaching to a seat cushion. The strength of PUF alone is weak, and a back base cloth is bonded to the back surface of PUF including the reinforcing effect. Conventionally, for the bonding of the back base cloth, bonding by flame lamination is generally carried out in the same manner as during the production of the surface layer, or bonding is carried out with an emulsion-based adhesive or a solvent-based adhesive.

[0004] However, in the bonding by the flame lamination method, hydrogen cyanide (HCN) is generated during production because flame is used, and there is a concern that the working environment deteriorates. Also, the flame lamination method has the same problem even when bonding the back base cloth. On the other hand, in the case of emulsion-based adhesives and solvent-based adhesives, a drying process is required, so there is a concern about a decrease in production efficiency. In addition, when the drying is insufficient, the adhesive may bleed out to the surface of the back base cloth, and blocking may occur during winding.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] The problem that this invention aims to solve is to provide a laminate that does not use the frame lamination method or a base fabric, and that has excellent blocking resistance and production efficiency. [Means for solving the problem]

[0007] The present invention provides a laminate having a polyurethane foam and a cured product of a moisture-curing polyurethane hot-melt resin composition, and having no base fabric, characterized in that the solidification time of the moisture-curing polyurethane hot-melt resin composition is less than 60 seconds.

[0008] Furthermore, the present invention provides a vehicle seat surface material characterized by having an additional surface layer provided on top of the polyurethane foam. [Effects of the Invention]

[0009] The laminate of the present invention does not require a backing fabric because the cured product of the moisture-curing polyurethane hot-melt resin composition is directly applied to the polyurethane foam. Furthermore, since the use of frame lamination and adhesives, which were conventionally used to support the backing fabric, can be omitted, it offers excellent production efficiency. In addition, because the moisture-curing polyurethane hot-melt resin composition used in the present invention has a fast solidification time (open time), the laminate can be wound immediately after manufacturing (adhesion during winding can be suppressed), which also contributes to excellent production efficiency and excellent blocking resistance after winding. Moreover, by employing a moisture-curing polyurethane hot-melt resin composition with a fast solidification time, the laminate of the present invention has good mechanical strength and slipperiness even without a backing fabric. [Modes for carrying out the invention]

[0010] The laminate of the present invention comprises a polyurethane foam and a cured product of a moisture-curing polyurethane hot-melt resin composition, and is a laminate without a base fabric, wherein the solidification time of the moisture-curing polyurethane hot-melt resin composition is less than 60 seconds.

[0011] In order to obtain the effects of the present invention, the moisture-curing polyurethane hot-melt resin composition must have a solidification time of less than 60 seconds. By using a material with such a short solidification time, a laminate can be obtained that does not require a backing fabric and has excellent production efficiency. The solidification time is more preferably in the range of 1 to 45 seconds, and even more preferably in the range of 1 to 30 seconds. The method for measuring the solidification time will be described in detail in the examples described later.

[0012] The moisture-curing polyurethane hot-melt resin composition preferably contains a urethane prepolymer (A) having an isocyanate group.

[0013] The urethane prepolymer (A) can be, for example, a reaction product of a polyol (a) and a polyisocyanate (b).

[0014] As the polyol (a), for example, aromatic polyester polyols, other polyester polyols, polyether polyols, polycarbonate polyols, polybutadiene polyols, silicone polyols, etc., other commercially available polyols can be used. These polyols may be used alone or in combination of two or more. Among these, aromatic polyester polyols are preferably used as an essential component, and it is more preferable to use aromatic polyester polyols in combination with other polyester polyols and / or polyether polyols.

[0015] The aforementioned aromatic polyester polyol is preferred because, due to its rigid structure, it solidifies quickly, exhibits even greater blocking resistance, and can also be imparted with slipperiness. For example, a reaction product of a compound having a hydroxyl group and a polybasic acid containing an aromatic polybasic acid; a reaction product of an aromatic compound having two or more hydroxyl groups and a polybasic acid; or a reaction product of an aromatic compound having two or more hydroxyl groups and a polybasic acid containing an aromatic polybasic acid can be used.

[0016] Examples of compounds having the hydroxyl group 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, triethylene glycol, tetraethylene glycol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, and 2-methyl-1,3-propyl glycol. Aliphatic compounds such as ropanediol, 2,2-diethyl-1,3-propanediol, 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, and pentaerythritol; and alicyclic compounds such as cyclopentanediol, cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, and their alkylene oxide adducts can be used. These compounds may be used alone or in combination of two or more.

[0017] Examples of aromatic compounds having two or more hydroxyl groups include bisphenol A, bisphenol F, and their alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts. These compounds may be used individually or in combination of two or more. Among these, alkylene oxide adducts of bisphenol A are preferred because they provide even better initial adhesive strength and flexibility, and the number of moles of alkylene oxide added is preferably in the range of 1 to 10 moles.

[0018] Examples of aromatic polybasic acids include phthalic acid, isophthalic acid, terephthalic acid, and phthalic anhydride. Other polybasic acids include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, and 1,12-dodecanedicarboxylic acid. These polybasic acids may be used individually or in combination of two or more. As the aromatic polybasic acid, phthalic acid is preferred in order to obtain even better effects of the present invention, and it is preferable to use one or more compounds selected from the group consisting of isophthalic acid, terephthalic acid, and phthalic anhydride.

[0019] Other polybasic acids that can be used include, for example, succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decandioic acid, dodecandioic acid, eicosanioic acid, citraconic acid, itaconic acid, anhydrous citraconic acid, and anhydrous itaconic acid.

[0020] As the aromatic polyester polyol, those derived from phthalic acid are particularly preferred because they provide even better blocking resistance, production efficiency, initial adhesive strength, and flexibility.

[0021] The number-average molecular weight of the aromatic polyester polyol is more preferably in the range of 250 to 5,000, and even more preferably in the range of 500 to 3,000. The number-average molecular weight of the aromatic polyester polyol is shown as the value measured by gel permeation chromatography (GPC) under the following conditions.

[0022] Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation) Column: The following columns manufactured by Tosoh Corporation were connected in series and used. "TSKgel G5000" (7.8 mm I.D. × 30 cm) × 1 piece "TSKgel G4000" (7.8 mm I.D. × 30 cm) × 1 piece "TSKgel G3000" (7.8 mm I.D. × 30 cm) × 1 piece "TSKgel G2000" (7.8 mm I.D. × 30 cm) × 1 piece Detector: RI (Differential refractometer) Column temperature: 40 °C Eluent: Tetrahydrofuran (THF) Flow rate: 1.0 mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4 mass%) Standard sample: A calibration curve was created using the following standard polystyrenes.

[0023] (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[[ID=​​​​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.

[0024] The content of the aromatic polyester polyol is preferably 15% by mass or more in the polyol (a).

[0025] As the other polyester polyols mentioned above, it is preferable to use crystalline polyester polyols other than the aromatic polyester polyols mentioned above, as this provides even better solidification time, blocking resistance, mechanical strength, and slipperiness. As the crystalline polyester polyols, for example, a reaction product of a compound having a hydroxyl group and a polybasic acid can be used. In this invention, "crystalline" refers to materials in which peaks of crystallization heat or fusion heat can be confirmed in DSC (differential scanning calorimeter) measurements in accordance with JIS K7121:2012, and "amorphous" refers to materials in which the above peaks cannot be confirmed.

[0026] Examples of compounds having a hydroxyl group include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, trimethylolpropane, trimethylolethane, and glycerin. These compounds may be used individually or in combination of two or more. Among these, it is preferable to use one or more selected from the group consisting of butanediol, hexanediol, octanediol, and decanediol, as this provides even better solidification time, blocking resistance, mechanical strength, and lubricity.

[0027] 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 compounds may be used individually or in combination of two or more. Among these, it is preferable to use one or more selected from the group consisting of sebacic acid, dodecanedioic acid, and adipic acid, as this provides even better solidification time, blocking resistance, mechanical strength, and lubricity.

[0028] The number-average molecular weight of the crystalline polyester polyol is preferably in the range of 500 to 10,000, and more preferably in the range of 1,000 to 4,000. The number-average molecular weight of the crystalline polyester polyol is the value measured by gel permeation chromatography (GPC).

[0029] The crystalline polyester polyol includes polycaprolactone polyol, which can also be preferably used. The number-average molecular weight of the polycaprolactone polyol is preferably in the range of 5,000 to 100,000, and more preferably in the range of 10,000 to 90,000. The number-average molecular weight of the polycaprolactone polyol is the value measured by gel permeation chromatography (GPC).

[0030] Examples of the polyether polyols that can be used include polyethylene glycol, polypropylene glycol, polytetramylene glycol, polyoxyethylene polyoxypropylene glycol, and polyoxyethylene polyoxytetramethylene glycol. These polyols may be used individually or in combination of two or more. Among these, polypropylene glycol and / or polyoxyethylene polyoxypropylene glycol are preferred, and polypropylene polyol is more preferred, as they provide even better coating properties.

[0031] The number-average molecular weight of the polyether polyol is preferably in the range of 300 to 10,000, and more preferably in the range of 350 to 5,000. The number-average molecular weight of the polyether polyol is the value measured by gel permeation chromatography (GPC).

[0032] The preferred amount (mass ratio) of the polyol (a) is within the following range, in which even better solidification time, blocking resistance, mechanical strength, and lubricity can be obtained.

[0033] The mass ratio of aromatic polyester polyol to crystalline polyester polyol is preferably in the range of 10-90 / 90-10, more preferably in the range of 20-80 / 80-20, and even more preferably in the range of 30-70 / 70-30. The mass ratio of aromatic polyester polyol to polyether polyol is preferably in the range of 50-99 / 1-50, more preferably in the range of 60-95 / 5-40, and even more preferably in the range of 70-90 / 10-30. The mass ratio of aromatic polyester polyol / crystalline polyether polyol / polyether polyol is preferably in the range of 5-95 / 10-80 / 1-50, more preferably in the range of 10-85 / 20-75 / 3-40, and even more preferably in the range of 20-80 / 30-70 / 5-30.

[0034] As the polyisocyanate (b), for example, aromatic polyisocyanates such as polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate isocyanate, xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate can be used; aliphatic or alicyclic polyisocyanates such as hexamethylene diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and tetramethylxylylene diisocyanate can be used. These polyisocyanates may be used alone or in combination of two or more. Among these, aromatic polyisocyanates are preferred from the viewpoint of mechanical strength, and diphenylmethane diisocyanate is more preferred.

[0035] As a method for producing the urethane prepolymer (A), for example, a mixture of the polyol (a) is dropped into a reaction vessel containing the polyisocyanate (b), and then heated, and the reaction is carried out under conditions in which the isocyanate groups of the polyisocyanate (b) are in excess of the hydroxyl groups of the polyol (a).

[0036] When producing the urethane prepolymer (A), the equivalent ratio (isocyanate group / hydroxyl group) of isocyanate groups in the polyisocyanate (b) and hydroxyl groups in the polyol (a) is preferably in the range of 1.5 to 5, and more preferably in the range of 1.6 to 2.5.

[0037] The isocyanate group content (hereinafter abbreviated as "NCO%") of the urethane prepolymer (A) is preferably in the range of 1 to 7% by mass, and more preferably in the range of 2.3 to 4.8% by mass, from the viewpoint of further improving moisture resistance and adhesive strength. The NCO% of the urethane prepolymer (A) is the value measured by potentiometric titration in accordance with JIS K1603-1:2007.

[0038] Furthermore, the urethane prepolymer (A) may be end-canceled using a monofunctional single-ended alcohol or single-ended amine, if necessary.

[0039] The moisture-curing polyurethane hot-melt resin composition preferably contains the urethane prepolymer (A), and may optionally contain other additives.

[0040] Examples of the aforementioned other additives include curing catalysts, antioxidants, tackifiers, plasticizers, stabilizers, fillers, dyes, pigments, fluorescent whitening agents, silane coupling agents, waxes, thermoplastic resins, and the like. These additives may be used individually or in combination of two or more.

[0041] The laminate of the present invention comprises a polyurethane foam and a cured product of the moisture-curing polyurethane hot-melt resin composition, and does not have a base fabric.

[0042] The polyurethane foam provides cushioning, breathability, and other properties, and known types can be used. The thickness of the polyurethane foam can be, for example, in the range of 1.5 to 20 mm.

[0043] Examples of base fabrics not used in this invention include 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, linen, silk, wool, fiberglass, carbon fibers, and blends thereof.

[0044] Methods for manufacturing the laminate include, for example, applying the moisture-curing polyurethane hot-melt resin composition onto the polyurethane foam. Methods for applying the moisture-curing polyurethane hot-melt resin composition include, for example, coater methods such as gravure coaters, roll coaters, spray coaters, T-die coaters, knife coaters, and comma coaters; precision methods such as dispensers, inkjet printing, screen printing, and offset printing; nozzle coating; spray coating; and film lamination methods. Among these, intermittent coating using a coater method is preferred because it provides even better mechanical strength and slipperiness. Before coating, the moisture-curing polyurethane hot-melt resin composition may be melted at 70 to 120°C.

[0045] The application amount of the moisture-curing polyurethane hot melt resin composition is 50 g / m². 2 Preferably less than 5-35 g / m 2 A range is more preferable.

[0046] After applying the moisture-curing polyurethane hot melt resin composition, cooling may be performed to accelerate the solidification rate of the moisture-curing polyurethane hot melt resin composition.

[0047] After the moisture-curing polyurethane hot-melt resin composition has solidified, release paper or a carrier sheet may be placed on top of the cured product. However, when used as a surface material for vehicle seats, it is preferable that the release paper or carrier sheet be removed.

[0048] The thickness of the cured product of the moisture-curing polyurethane hot-melt resin composition can be, for example, in the range of 5 to 200 μm.

[0049] Because the laminate of the present invention has the above-mentioned effects, it can be particularly suitably used as a surface material for vehicle seats. Examples of the structure of the surface material for vehicle seats include a laminate in which a cured layer of a moisture-curing polyurethane hot-melt resin composition, a polyurethane foam, and a surface layer are sequentially laminated.

[0050] A release paper or carrier sheet may be provided below the cured layer of the moisture-curing polyurethane hot-melt resin composition for ease of transport and other reasons.

[0051] A known adhesive may be used between the polyurethane foam and the surface layer, if necessary. Examples of such known adhesives include acrylic adhesives, urethane adhesives, and moisture-curing polyurethane hot-melt adhesives.

[0052] The surface layer can be formed from known materials, such as solvent-based polyurethane, water-based polyurethane, polyvinyl chloride, thermoplastic polyurethane (TPU), etc.

[0053] The aforementioned vehicle seat covering material can, for example, be used to cover the seats of a vehicle. [Examples]

[0054] The present invention will be described in more detail below using examples.

[0055] [Synthesis Example 1] Preparation of moisture-curing polyurethane hot melt resin composition (1) In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 23 parts by mass of aromatic polyester polyol (reaction product of neopentyl glycol and orthophthalic acid, number average molecular weight: 1,000, hereinafter abbreviated as "aromatic PEs1"), 80.5 parts by mass of crystalline polyester polyol (reaction product of 1,6-hexanediol and sebaciic acid, number average molecular weight: 3,500, hereinafter abbreviated as "crystalline PEs1"), and 11.5 parts by mass of polyether polyol (polypropylene glycol, number average molecular weight: 400, hereinafter abbreviated as "PEt1") were added and mixed. The mixture was then heated under reduced pressure at 70°C until the moisture content in the flask was reduced to 0.05% by mass or less. Next, the flask was cooled to 90°C, and 31.8 parts by mass of 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as "MDI"), which had been melted at 70°C, was added. The mixture was then reacted at 110°C for approximately 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, thereby obtaining a hot-melt urethane prepolymer (1) with an NCO%; 3.0% by mass content, which served as a moisture-curing polyurethane hot-melt resin composition (1).

[0056] [Synthesis Example 2] Preparation of moisture-curing polyurethane hot melt resin composition (2) In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 39.6 parts by mass of aromatic polyester polyol (reaction product of diethylene glycol and orthophthalic acid, number average molecular weight; 1,000, hereinafter abbreviated as "aromatic PEs2"), 26.4 parts by mass of aromatic polyester polyol (reaction product of 1,6-hexanediol and orthophthalic acid, number average molecular weight; 2,000, hereinafter abbreviated as "aromatic PEs3"), 52.8 parts by mass of crystalline polyester polyol (reaction product of 1,4-butanediol and adipic acid, number average molecular weight; 4,000, hereinafter abbreviated as "crystalline PEs2"), and 13.2 parts by mass of PEt1 were added and mixed. The mixture was then heated under reduced pressure at 70°C until the moisture content in the flask was 0.05% by mass or less. Next, the flask was cooled to 90°C, 48.3 parts by mass of MDI melted at 70°C were added, and the mixture was reacted at 110°C for about 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, thereby obtaining a hot-melt urethane prepolymer (2) with an NCO%; 4.3% by mass, which served as a moisture-curing polyurethane hot-melt resin composition (2).

[0057] [Synthesis Example 3] Preparation of moisture-curing polyurethane hot melt resin composition (3) In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 33.3 parts by mass of aromatic PEs1, 44.4 parts by mass of aromatic PEs2, and 33.3 parts by mass of crystalline PEs2 were added and mixed. The mixture was then heated under reduced pressure at 70°C until the moisture content in the flask was reduced to 0.05% by mass or less. Next, the flask was cooled to 90°C, and 31.2 parts by mass of MDI melted at 70°C was added. The mixture was reacted at 110°C for approximately 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, thereby obtaining a hot-melt urethane prepolymer (3) with an NCO%; 2.3% by mass, which served as a moisture-curing polyurethane hot-melt resin composition (3).

[0058] [Synthesis Example 4] Preparation of moisture-curing polyurethane hot melt resin composition (4) In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 26.7 parts by mass of aromatic PEs1, 57.9 parts by mass of crystalline PEs2, and 4.5 parts by mass of PEt1 were added and mixed. The mixture was then heated under reduced pressure at 70°C until the moisture content in the flask was reduced to 0.05% by mass or less. Next, the flask was cooled to 90°C, and 23.5 parts by mass of MDI melted at 70°C was added. The mixture was reacted at 110°C for approximately 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, thereby obtaining a hot-melt urethane prepolymer (4) with an NCO%; 3.1% by mass, which served as a moisture-curing polyurethane hot-melt resin composition (4).

[0059] [Synthesis Example 5] Preparation of moisture-curing polyurethane hot melt resin composition (5) In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 16.1 parts by mass of aromatic PEs1, 58.9 parts by mass of crystalline PEs1, 16.1 parts by mass of aromatic PEs2, and 16.1 parts by mass of polyether polyol (polypropylene glycol, number average molecular weight; 1,000, hereinafter abbreviated as "PEt2") were added and mixed. The mixture was then heated under reduced pressure at 70°C until the moisture content in the flask was reduced to 0.05% by mass or less. Next, the flask was cooled to 90°C, 30.0 parts by mass of MDI melted at 70°C was added, and the mixture was reacted at 110°C for about 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, thereby obtaining a hot-melt urethane prepolymer (5) with an NCO%; 3.4% by mass, which served as a moisture-curable polyurethane hot-melt resin composition (5).

[0060] [Synthesis Example 6] Preparation of moisture-curing polyurethane hot melt resin composition (6) In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 96.9 parts by mass of aromatic PEs1 and 5.1 parts by mass of PEt1 were added and mixed. The mixture was then heated under reduced pressure at 70°C until the moisture content in the flask was reduced to 0.05% by mass or less. Next, the flask was cooled to 90°C, 48.0 parts by mass of MDI melted at 70°C were added, and the mixture was reacted at 110°C for approximately 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, thereby obtaining a hot-melt urethane prepolymer (6) with an NCO%; 4.5% by mass, which served as a moisture-curing polyurethane hot-melt resin composition (6).

[0061] [Synthesis Example 7] Preparation of moisture-curing polyurethane hot melt resin composition (7) In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 21.2 parts by mass of aromatic PEs1, 53 parts by mass of crystalline PEs2, 21.2 parts by mass of aromatic PEs2, and 10.6 parts by mass of PEt1 were added and mixed. The mixture was then heated under reduced pressure at 70°C until the moisture content in the flask was reduced to 0.05% by mass or less. Next, the flask was cooled to 90°C, and 41.1 parts by mass of MDI melted at 70°C was added. The mixture was reacted at 110°C for approximately 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, thereby obtaining a hot-melt urethane prepolymer (7) with an NCO%; 4.6% by mass, which served as a moisture-curing polyurethane hot-melt resin composition (7).

[0062] [Comparative Synthesis Example 1] Preparation of moisture-curing polyurethane hot melt resin composition (R1) In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 29 parts by mass of crystalline PEs2 and 116 parts by mass of PEt2 were placed and mixed. The mixture was then heated under reduced pressure at 70°C until the moisture content in the flask was reduced to 0.05% by mass or less. Next, the flask was cooled to 90°C, and 43.1 parts by mass of MDI melted at 70°C was added. The mixture was reacted at 110°C for approximately 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, thereby obtaining a hot-melt urethane prepolymer (R1) with an NCO%; 2.2% by mass, which served as the moisture-curing polyurethane hot-melt resin composition (R1).

[0063] [Comparative Synthesis Example 2] Preparation of moisture-curing polyurethane hot melt resin composition (R2) In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 12 parts by mass of aromatic PEs1 and 108 parts by mass of PEt2 were added and mixed. The mixture was then heated under reduced pressure at 70°C until the moisture content in the flask was reduced to 0.05% by mass or less. Next, the flask was cooled to 90°C, and 52.5 parts by mass of MDI melted at 70°C was added. The mixture was reacted at 110°C for approximately 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, thereby obtaining a hot-melt urethane prepolymer (R2) with an NCO%; 4.3% by mass, which served as the moisture-curing polyurethane hot-melt resin composition (R2).

[0064] [Methods for evaluating production efficiency] The solidification time was evaluated according to the [Method for Measuring Solidification Time] described below. A solidification time of less than 60 seconds was marked with "○", and any other result was marked with "×".

[0065] [Method for measuring solidification time] [Examples 1-7, Comparative Examples 1-2] In a constant temperature and humidity chamber adjusted to 23°C and 50% humidity, moisture-curing polyurethane hot-melt resin compositions (1) to (7) and (R1) to (R2) obtained in Synthesis Examples 1 to 7 were intermittently coated onto polyurethane foam separately in that order using a gravure roll. Starting from immediately after coating, a cotton swab was continuously applied to the coated surface, and the point at which the cotton swab no longer stuck was defined as the solidification time (open time). Compositions with a solidification time of less than 60 seconds were marked with "○", and those with a solidification time of 60 seconds or more were marked with "×".

[0066] [Method for evaluating blocking resistance] Two A4-sized sheets were cut from the laminated sheet obtained using the method described above [Method for measuring solidification time]. A 2kg load was placed on an A4-sized acrylic plate and left for one day. After that, the presence or absence of material breakage was checked, and those without breakage were evaluated as "○" and those with breakage as "×".

[0067] [Method for measuring number-average molecular weight] The number-average molecular weights of the polyols used in the synthesis examples and comparative synthesis examples are shown as values ​​obtained by gel permeation column chromatography (GPC) under the following conditions.

[0068] 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.

[0069] (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.

[0070] [Table 1]

[0071] [Table 2]

[0072] The laminate of the present invention has been found to have a fast solidification time, does not require a backing fabric, and has excellent production efficiency. It has also been found to have excellent blocking resistance.

[0073] On the other hand, Comparative Examples 1 and 2 were both found to have slow solidification times and poor production efficiency. They also exhibited poor resistance to blocking.

Claims

1. A method for manufacturing a laminate having a polyurethane foam and a cured product of a moisture-curing polyurethane hot-melt resin composition, and without a backing fabric. A method for producing a laminate, characterized by directly applying the moisture-curing polyurethane hot-melt resin composition, which has a solidification time of less than 60 seconds, onto the polyurethane foam.

2. The method for producing a laminate according to claim 1, wherein the moisture-curing polyurethane hot-melt resin composition uses an aromatic polyester polyol as the polyol raw material.

3. A method for producing a laminate according to claim 1, comprising intermittently coating the moisture-curing polyurethane hot-melt resin composition.

4. A method for producing a laminate according to claim 1, further comprising providing an epidermal layer on the polyurethane foam.

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