Method for manufacturing a moisture-permeable film and a laminate, and moisture-permeable film

Abstract

The present invention provides a method for producing a highly permeable moisture-permeable film that is thin, has suppressed coating defects, and does not use solvents. [Solution] A moisture-curable polyurethane hot-melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) with a polyisocyanate (B) is heated and melted, and continuously applied to the surface of a release substrate having an arithmetic mean height Sa of 0.90 μm or more and / or a gloss of 25.0 or less to form a coating film with a thickness of less than 30 μm; and at least moisture-cured the coating film to have a transmittance of 4000 (g / m²). 2 A method for manufacturing a moisture-permeable film, comprising a step X2 of forming a moisture-permeable film of 24 hours or more.

Description

[Technical Field]

[0001] This disclosure relates to a method for manufacturing a breathable film that can be used in the manufacture of breathable waterproof clothing such as sportswear, as well as films for adhesive bandages, films for disposable diapers, and moisture-regulating building material films used for walls and roofs. [Background technology]

[0002] A breathable film that has both water vapor permeability (moisture permeability) and water impermeability (waterproofing) is used by laminating it to breathable waterproof fabrics or synthetic leather (hereinafter sometimes referred to as breathable waterproof fabrics, etc.) where breathability is required.

[0003] Moisture-permeable films are typically formed by casting a solvent-based or aqueous resin solution onto a release-type substrate, followed by the evaporation of the solvent. However, this manufacturing method has recently become problematic because it requires a tremendous amount of energy to evaporate the solvent.

[0004] On the other hand, a method for producing a moisture-permeable film using a hot-melt resin composition that is substantially solvent-free is effective in that it can overcome the problems caused by the solvent described above. Examples of such hot-melt resin compositions include moisture-curable polyurethane hot-melt compositions (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2007-63510 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, when manufacturing thin, moisture-permeable films with a thickness of less than 30 μm (especially 20 μm or less) using a solvent-free moisture-curing polyurethane hot-melt composition, the properties of hot melting make it easy for defects such as streaks, repellency, and pinholes (hereinafter collectively referred to as "coating defects" or "defects") to occur in the coating film and / or the cured film of the coating film, resulting in poor appearance and reduced moisture permeability. Furthermore, even if a thin, moisture-permeable film without defects can be manufactured, high moisture permeability may not be achieved. In contrast, in manufacturing methods for moisture-permeable films using solvent-based or water-based resin solutions, the thickness of the coating film can be made relatively large during the resin solution application stage, and the film thickness becomes the desired thinness after drying as the solvent or water evaporates, thus making the above problems less likely to occur.

[0007] This disclosure is made in view of the above circumstances and provides a method for producing a thin, highly permeable film with high moisture permeability, without using solvents such as water or other solvents, and with suppressed occurrence of defects such as streaks, blemishes, and pinholes. [Means for solving the problem]

[0008] This disclosure includes the following embodiments. [1] A moisture-curable polyurethane hot melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) with a polyisocyanate (B) is heated and melted, and the heated and melted moisture-curable polyurethane hot melt resin composition is continuously applied to the first main surface of a release substrate having an arithmetic mean height Sa of at least 0.90 μm and / or a gloss of 25.0 or less, to form a coating film with a thickness of less than 30 μm; and a step X2 in which the coating film is at least moisture-cured to form a moisture-permeable film which is a cured product of the moisture-curable polyurethane hot melt resin composition, wherein the permeability of the moisture-permeable film is 4000 (g / m²). 2 A method for manufacturing a moisture-permeable film that is 24 hours or longer. [2] The method for producing a moisture-permeable film according to [1], wherein the polyol (A) further comprises a crystalline polyester polyol (a3). [3] A method for producing a moisture-permeable film according to either [1] or [2], wherein the polyol (A) further comprises a polyol (a5) having three hydroxyl groups. [4] A method for producing a moisture-permeable film according to any one of [1] to [3] above, wherein the melt viscosity of the moisture-curing urethane hot-melt resin composition at 120°C is in the range of 100 to 10,000 mPa·s. [5] A method for producing a moisture-permeable film according to any one of [1] to [4] above, wherein the proportion of polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) in the polyol (A) is 50% by mass or more of the total amount (100% by mass) of the polyol (A). [6] A method for producing a moisture-permeable film according to any one of [1] to [5] above, wherein the proportion of oxyethylene structures in the polyol (A) is 10 mol / kg or more. [7] A method for manufacturing a laminate having a moisture-permeable film and an adherend in direct contact with one side of the moisture-permeable film, comprising: step Y1 of heating and melting a moisture-curable polyurethane hot-melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) with a polyisocyanate (B); and continuously applying the heated and melted moisture-curable polyurethane hot-melt resin composition onto the first main surface of a release substrate having an arithmetic mean height Sa of at least 0.90 μm and / or a gloss of 25.0 or less to form a coating film with a thickness of less than 30 μm; and step Y2 of contacting the surface of the adherend to the surface of the coating film and bonding them, and at least moisture-curing the coating film to form a moisture-permeable film which is a cured product of the moisture-curable polyurethane hot-melt resin composition, wherein the permeability of the moisture-permeable film is 4000 (g / m²). 2 A method for manufacturing a laminate, which takes 24 hours or more. [8] The method for manufacturing a laminate according to [7] above, wherein the adherend is a base fabric. [9] The method for manufacturing a laminate according to [7] above, wherein the adherend is a release film or release paper.

[10] A method for producing a laminate according to any one of [7] to [9] above, wherein the polyol (A) further comprises a crystalline polyester polyol (a3).

[11] A method for producing a laminate according to any one of [7] to

[10] above, wherein the polyol (A) further comprises a polyol (a5) having three hydroxyl groups.

[12] A method for producing a laminate according to any one of [7] to

[11] , wherein the melt viscosity of the moisture-curing urethane hot melt resin composition at 120°C is in the range of 100 to 10,000 mPa·s.

[13] A method for producing a laminate according to any one of [7] to

[12] above, wherein the proportion of polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) in the polyol (A) is 50% by mass or more of the total amount (100% by mass) of the polyol (A).

[14] A method for producing a laminate according to any one of [7] to

[13] above, wherein the proportion of oxyethylene structures in the polyol (A) is 10 mol / kg or more.

[15] A cured product of a moisture-curing polyurethane hot-melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) with a polyisocyanate (B), having a thickness of less than 30 μm and a transmittance of 4000 (g / m²). 2 A breathable film with a moisture permeability of 24 hours or more.

[16] The moisture-permeable film according to

[15] , wherein the polyol (A) further comprises a crystalline polyester polyol (a3).

[17] The moisture-permeable film according to

[15] or

[16] , wherein the polyol (A) further comprises a polyol (a5) having three hydroxyl groups.

[18] A moisture-permeable film according to any one of

[15] to

[17] above, wherein the proportion of polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) in the polyol (A) is 50% by mass or more of the total amount (100% by mass) of the polyol (A).

[19] A moisture-permeable film according to any one of

[15] to

[18] above, wherein the proportion of oxyethylene structures in the polyol (A) is 10 mol / kg or more. [Effects of the Invention]

[0009] According to this disclosure, it is possible to manufacture a thin, highly permeable moisture-permeable film with suppressed defects such as streaking, bleed, and pinholes, without using solvents such as water or other solvents. [Modes for carrying out the invention]

[0010] I. Method for manufacturing moisture-permeable film The present disclosure provides a method for producing a moisture-permeable film, comprising: step X1 of heating and melting a moisture-curable polyurethane hot-melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) with a polyisocyanate (B); and continuously applying the heated and melted moisture-curable polyurethane hot-melt resin composition onto the first main surface of a release substrate having an arithmetic mean height Sa of at least 0.90 μm and / or a gloss of 25.0 or less to form a coating film with a thickness of less than 30 μm; and step X2 of at least moisture-curing the coating film to form a moisture-permeable film which is a cured product of the moisture-curable polyurethane hot-melt resin composition, wherein the permeability of the moisture-permeable film is 4000 (g / m²). 2 (24h) or longer. Note that the above polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) may be referred to as component (a1) in the explanation.

[0011] According to the method for producing a moisture-permeable film of the present disclosure, even a thin coating film with a thickness of less than 30 μm (preferably 20 μm or less) can be formed by continuously applying a moisture-curable polyurethane hot-melt resin composition containing no solvent, and a moisture-permeable film having high moisture permeability and less likely to have coating film defects can be produced.

[0012] Also, according to the method for producing a moisture-permeable film of the present disclosure, by using a moisture-curable polyurethane hot-melt resin composition containing the component (a1) as an essential component, the coating film of the moisture-curable polyurethane hot-melt resin composition has moisture permeability and adhesiveness. Therefore, a moisture-permeable film having a function as an adhesive layer can be produced by curing the coating film. When producing a laminate by laminating an adherend such as a moisture-permeable waterproof fabric and a moisture-permeable film, since the moisture-permeable film also serves as an adhesive layer, a thin laminate can be produced, and the interfacial adhesive strength between the moisture-permeable film and the adherend can be increased.

[0013] Hereinafter, the method for producing a moisture-permeable film of the present disclosure will be described step by step.

[0014] 1. Step X1 In Step X1, a moisture-curable polyurethane hot-melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyoxyethylene glycol (a1) and a polyisocyanate (B) is heated and melted, and the arithmetic mean height Sa of at least the first main surface is 0.90 μm or more and / or the glossiness is 25.0 or less. The heated and melted moisture-curable polyurethane hot-melt resin composition is continuously applied onto the first main surface of the mold-releasing substrate to form a coating film having a thickness of less than 30 μm.

[0015] (1) Mold-releasing substrate The above-mentioned release substrate has an arithmetic mean height Sa of at least 0.90 μm or more on its first main surface, and / or a gloss of 25.0 or less. The first main surface of the above-mentioned release substrate is the surface on which the moisture-curing polyurethane hot melt resin composition is applied (the surface that comes into contact with the moisture-curing polyurethane hot melt resin composition). The first main surface of the above-mentioned release substrate only needs to satisfy a predetermined range for at least one of the arithmetic mean height Sa and gloss, and it is preferable that both the arithmetic mean height Sa and gloss satisfy a predetermined range.

[0016] The above-mentioned release substrate preferably has an arithmetic mean roughness (Sa) of 0.90 μm or more on its first main surface, more preferably 0.92 μm or more, even more preferably 0.95 μm or more, even more preferably 0.98 μm or more, and particularly preferably 1.0 μm or more. Furthermore, the upper limit of the arithmetic mean roughness (Sa) of the first main surface of the above-mentioned release substrate is not particularly limited as long as a coating film of the moisture-curing polyurethane hot-melt resin composition can be formed and the cured coating film can be peeled off, but it is preferably 25 μm or less, more preferably 22 μm or less, and even more preferably 19 μm or less. The arithmetic mean roughness (Sa) is a parameter that extends the arithmetic mean height Ra of a line to a surface, and is a value measured on the surface of the release substrate using a laser microscope in accordance with ISO 25178.

[0017] Furthermore, the release substrate is preferably such that the gloss of the first main surface is 25.0 or less, preferably in the range of 0.1 to 25.0, more preferably in the range of 1.0 to 20.0, and even more preferably in the range of 2.0 to 17.5.

[0018] By having at least one of the arithmetic mean roughness (Sa) and gloss of the first main surface of the above-mentioned release substrate within the above range, when a solvent-free moisture-curing polyurethane hot-melt resin composition that has been melted and heated is continuously applied to form a thin coating film with a thickness of less than 30 μm (more preferably 20 μm or less), the occurrence of coating film defects can be suppressed, and the moisture-permeable film, which is the cured product of the coating film, becomes less likely to tear when peeled off from the release substrate. A moisture-permeable film having thinness, high moisture permeability, and excellent mechanical strength can be manufactured.

[0019] The glossiness of the above-mentioned release agent substrate is measured using a BYK Microgloss 45XX measuring device, in accordance with JIS Z 8741:1997, at a light incidence angle of 60°.

[0020] From the viewpoint of retaining the moisture-curing polyurethane hot-melt resin composition coating on the first main surface of the above-mentioned release substrate, it is preferable that the peeling force of the first main surface is greater than 0 N / inch, and from the viewpoint of easily peeling the moisture-permeable film, which is a deposition of the coating film, from the release substrate, it is preferable that the peeling force of the first main surface is 10 N / N / inch or less. In particular, the range of 0.04 N / inch to 10 N / inch is preferred, the range of 0.2 N / inch to 8 N / inch is more preferred, and the range of 0.45 N / inch to 6 N / inch is even more preferred. By having the peeling force of the first main surface of the above-mentioned release substrate within the above range, the occurrence of coating defects can be suppressed when continuously coating a moisture-curing polyurethane hot-melt resin composition to form a thin coating film, and a good coating can be formed.

[0021] The peeling force of the above-mentioned release substrate was determined by cutting a 15cm piece of polyester adhesive tape (NITTOTAPE No.31, manufactured by Nitto Denko Corporation, 2.5cm wide) onto the release substrate, pre-laminating it with a hand roll, and then laminating it to the release substrate using a laminator with metal and rubber rolls adjusted to 40°C at a linear pressure of 0.2MPa. The laminated polyester adhesive tape was then stretched using a tensile testing machine under conditions of 23°C±2°C, RH50±5%, a peel angle of 180°C, and a tensile strength of 200mm / min. The value measured (N / inch) was adopted as the peeling force of the release substrate.

[0022] The structure of the above-mentioned release material is not particularly limited and may be, for example, a single-layer release film mainly composed of the resin described later, or a laminate in which a release layer mainly composed of the resin described later is provided on at least one side of the material. Specific examples of the above-mentioned laminate include release paper (paper with a release layer), release treated cloth, water-repellent treated cloth, resin film with release paper, resin film with a release layer, and the like.

[0023] The resin that forms the main component of the above-mentioned release film or release layer is not particularly limited, and resins used in general-purpose release films and release agents can be used. Examples of such resins include olefin resins such as polyethylene resin and polypropylene resin, polyester resins, fluororesins, and silicone resins. Among these, resins selected from olefin resins and silicone resins are preferred because they exhibit good release properties for polyurethane. In other words, it is preferable that the layer constituting the first main surface (the surface in contact with the moisture-curing polyurethane hot melt resin composition) of the above-mentioned release substrate is mainly composed of olefin resin and / or silicone resin. The main component refers to the component that is present in the largest amount among the constituent components, and it is preferable that the layer constituting the first main surface (the surface in contact with the moisture-curing polyurethane hot melt resin composition) of the above-mentioned release substrate is substantially composed of olefin resin and / or silicone resin.

[0024] When the above-mentioned release-resistant substrate is a laminate having a release layer on one or both sides of the substrate, the substrate is not particularly limited, but examples include paper, fabric, film, or sheet. The release layer in the above-mentioned laminate may be formed by coating the substrate with resin, or the release layer may be bonded directly to the surface of the substrate or via another layer.

[0025] (2) Moisture-curing polyurethane hot melt resin composition The above moisture-curing polyurethane hot-melt resin composition contains a urethane prepolymer which is a reaction product of at least a polyol (A) and a polyisocyanate (B). The above moisture-curing polyurethane hot-melt resin composition can function as an adhesive.

[0026] The above-mentioned urethane prepolymer has "hot melt properties." "Hot melt properties" are a property resulting from the molecular structure of the selected prepolymer, in which, at room temperature, it is in a solid or viscous state that makes it difficult to apply to a substrate (e.g., a release substrate), but it melts when heated, making it possible to apply to a substrate (e.g., a release substrate), and solidifies when cooled, exhibiting adhesive properties. In this disclosure, the term "hot melt" is used as a general term for the above-mentioned properties and substances having such properties.

[0027] -Polyol (A)- The polyol (A) above comprises at least the polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1). Since component (a1) has an oxyethylene group with excellent hydrophilicity, a moisture-permeable film with excellent moisture permeability can be produced.

[0028] The number-average molecular weight of component (a1) described above is preferably in the range of 900 to 25000, more preferably in the range of 1000 to 20000, and even more preferably in the range of 2000 to 15000, from the viewpoint of being able to produce a moisture-permeable film that has high moisture permeability even as a thin film, and possesses practical levels of mechanical strength and a flexible texture.

[0029] In this specification, unless otherwise specified, the number-average molecular weight is the value measured by gel permeation chromatography (GPC) under the following conditions.

[0030] 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.

[0031] (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.

[0032] The proportion (amount used) of component (a1) in the polyol (A) is preferably in the range of 20% to 99% by mass, more preferably in the range of 30% to 95% by mass, even more preferably in the range of 40% to 90% by mass, and particularly preferably in the range of 50% to 85% by mass, from the viewpoint of the resulting moisture-permeable film being thin and exhibiting high moisture permeability. A proportion (amount used) of component (a1) in the polyol (A) of 50% by mass or more is particularly preferable because it allows for high moisture permeability even with a coating thickness of 15 μm or less, and enables the production of a thinner and more moisture-permeable film.

[0033] The above polyol (A) may contain one or more aromatic polyester polyols (a2) as optional components, in addition to the above-mentioned component (a1). Note that aromatic polyester polyol (a2) may sometimes be referred to as component (a2). Furthermore, component (a2) does not include polyester polyol (a4), which is a reaction product (condensation product) of a polyol obtained by adding an alkylene oxide to bisphenol A and a polycarboxylic acid, as described later.

[0034] The above-mentioned aromatic polyester polyol (a2) is not particularly limited, but from the viewpoint of increasing the mechanical strength of the resulting moisture-permeable film, an aromatic polyester polyol having a phthalic acid skeleton is preferred. Examples of aromatic polyester polyols having a phthalic acid skeleton include reaction products of a polybasic acid containing phthalic acid and a compound having two or more hydroxyl groups.

[0035] As the phthalic acid mentioned above, orthophthalic acid, isophthalic acid, terephthalic acid, and phthalic anhydride can be used. These may be used individually or in combination of two or more. Among these, orthophthalic acid and / or phthalic anhydride are preferred because they allow for the production of a moisture-permeable film with excellent mechanical strength and an even better texture.

[0036] The phthalic acid mentioned above may be used in combination with other polybasic acids as needed. Examples of other polybasic acids include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, and 1,12-dodecanedicarboxylic acid. These may be used individually or in combination of two or more.

[0037] The phthalic acid content in the polybasic acid, which is the raw material for aromatic polyester polyol (a2), is preferably 60% by mass or more, and more preferably 80% by mass or more, of the total amount (100% by mass) of the polybasic acid, from the viewpoint of easily obtaining the effects of the phthalic acid skeleton described above. It may also be 100% by mass.

[0038] Examples of compounds having two or more hydroxyl groups that can be used as raw materials for aromatic polyester polyol (a2) include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, trimethylolpropane, trimethylolethane, glycerin, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propylene glycol, 2,4-diethyl-1,5-pentanediol, 2-methyl-1,8-octanediol, and 2-ethyl-2-butyl-1,3-propanediol. These compounds may be used individually or in combination of two or more. Among these, neopentyl glycol and diethylene glycol are preferred because they can further enhance the amorphous properties.

[0039] The number-average molecular weight of the above aromatic polyester polyol (a2) is preferably in the range of 900 to 5,000, and more preferably in the range of 1,000 to 3,000, from the viewpoint of producing a moisture-permeable film with excellent mechanical strength and texture. The number-average molecular weight of the above aromatic polyester polyol (a2) is a value measured by the same measurement method as the number-average molecular weight of component (a1) above.

[0040] The proportion (amount used) of aromatic polyester polyol (a2) in the above polyol (A) can be in the range of 0% to 60% by mass of the total amount (100% by mass) of the above polyol (A). From the viewpoint of obtaining a moisture-proof film with high moisture permeability and excellent mechanical strength in a thin film, the range of 5% to 55% by mass of the above polyol (A) is preferred, the range of 8% to 50% by mass is more preferred, and the range of 10% to 40% by mass is even more preferred.

[0041] The polyol (A) described above may contain one or more crystalline polyester polyols (a3) ​​as optional components, in addition to component (a1). Note that crystalline polyester polyol (a3) ​​may sometimes be referred to as component (a3).

[0042] The moisture-curing polyurethane hot-melt resin composition further contains crystalline polyester polyol (a3), which can further improve the normal state and water-resistant adhesive strength, mechanical strength, and moisture permeability of the resulting moisture-permeable film. In this specification, "crystalline" refers to a material in which a peak of crystallization heat or fusion heat can be confirmed by DSC (differential scanning calorimeter) measurement in accordance with JIS K7121-1987.

[0043] The above-mentioned crystalline polyester polyol (a3) ​​is obtained by a condensation reaction between a low molecular weight polyol and a polycarboxylic acid.

[0044] Low molecular weight polyols used as raw materials for crystalline polyester polyol (a3) ​​include, for example, ethylene glycol, diethylene glycol 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, 10-decanediol, etc. Among these, the use of neopentyl glycol is preferable for imparting a flexible texture to the moisture-permeable film of the present invention.

[0045] Examples of polycarboxylic acids that can be used as raw materials for crystalline polyester polyol (a3) ​​include succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecamethylenedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, hexahydroisophthalic acid, and phthalic anhydride.

[0046] The above-mentioned crystalline polyester polyol (a3) ​​may be one or more of aliphatic, alicyclic, and aromatic, but it is preferable that it contains crystalline aliphatic polyester polyol (a3-1). The above-mentioned crystalline aliphatic polyester polyol (a3-1) can be a reaction product of a polybasic acid and a compound having two or more hydroxyl groups. Examples of the above-mentioned polybasic acid include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, and 1,12-dodecanedicarboxylic acid. Examples of the above-mentioned compound having two or more hydroxyl groups include the compounds having two or more hydroxyl groups that were exemplified as raw materials for the above-mentioned "aromatic polyester polyol (a2)".

[0047] In particular, from the viewpoint of being able to produce a moisture-permeable film with enhanced crystallinity and even superior mechanical strength, the crystalline polyester polyol (a3) ​​is preferably a crystalline aliphatic polyester polyol which is a reaction product of one or more polybasic acids selected from the group consisting of adipic acid, sebacic acid, and 1,12-dodecanedicarboxylic acid, and one or more compounds having two or more hydroxyl groups selected from the group consisting of ethylene glycol, butanediol, hexanediol, and dodecanediol.

[0048] The number-average molecular weight of the crystalline polyester polyol (a3) ​​is preferably in the range of 900 to 10,000, and more preferably in the range of 1,000 to 9,000, from the viewpoint of producing a moisture-permeable film with even better mechanical strength and moisture permeability. The number-average molecular weight of the crystalline polyester polyol (a3) ​​is a value measured by the same measurement method as the number-average molecular weight of component (a1) above.

[0049] The proportion (amount used) of crystalline polyester polyol (a3) ​​in the above polyol (A) can be in the range of 0% to 60% by mass relative to the total amount (100% by mass) of polyol (A). From the viewpoint of obtaining a moisture-proof film with an even better texture, a range of 1% to 55% by mass relative to 100% by mass of polyol (A) is preferred, and a range of 2% to 50% by mass is more preferred.

[0050] In addition to the above-mentioned component (a1), the polyol (A) may optionally contain one or more polyester polyols (a4) (hereinafter sometimes referred to as component (a4)), which are reaction products (condensation products) of a polyol obtained by adding an alkylene oxide to bisphenol A and a polycarboxylic acid. Component (a4) is not included in components (a1) to (a3).

[0051] The number-average molecular weight of component (a4) is preferably in the range of 500 to 10000, and more preferably in the range of 1000 to 4000. Having the number-average molecular weight of component (a4) within this range reduces the viscosity of the moisture-curable polyurethane hot-melt resin composition in the heated and melted state, thereby improving continuous coating properties. The number-average molecular weight of component (a4) is measured using the same method as the number-average molecular weight of component (a1).

[0052] The above component (a4) preferably has a glass transition temperature in the range of -50°C to 40°C. The glass transition temperature of the above component (a4) can be adjusted, for example, by adjusting the amount of alkylene oxide added to bisphenol A. The glass transition temperature is the endothermic peak temperature measured using a DSC (Differential Scanning Calorimetry) in a nitrogen atmosphere from -80°C at a heating rate of 5°C / min.

[0053] The polyol obtained by adding an alkylene oxide to bisphenol A can be produced, for example, by adding an alkylene oxide to bisphenol A using a well-known and conventional method. Among these, polyether polyols obtained by adding an alkylene oxide to bisphenol A are preferred.

[0054] As the alkylene oxide that is the raw material for component (a4) above, for example, ethylene oxide, propylene oxide, etc. can be used, and among these, propylene oxide is preferred.

[0055] The alkylene oxide, which is the raw material for component (a4) above, is preferably added to the bisphenol A in an amount of 1 mole to 10 moles, more preferably in an amount of 2 moles to 8 moles, and even more preferably in an amount of 4 moles to 8 moles. Component (a4) above is compatible with other polyols, and a moisture-permeable film exhibiting superior normal and water-resistant adhesive strength, moisture permeability, and flexibility can be produced.

[0056] The polycarboxylic acid used as a raw material for component (a4) above is preferably one or more compounds selected from the group consisting of aliphatic polycarboxylic acids, alicyclic dicarboxylic acids, and aromatic polycarboxylic acids. As the aliphatic polycarboxylic acid used as the raw material for component (a4) above, for example, succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, etc., can be used. These may be used individually or in combination of two or more. Among these, aliphatic polycarboxylic acids having 6 to 10 carbon atoms are preferred from the viewpoint of producing a moisture-permeable film with excellent initial cohesive strength and durability, and more specifically, compounds selected from the group consisting of sebacic acid, adipic acid, and dodecanedicarboxylic acid are preferred. As the aromatic polycarboxylic acid that is the raw material for component (a4) above, for example, phthalic acid, isophthalic acid, terephthalic acid, etc. can be used, and isophthalic acid is preferred.

[0057] In particular, the polycarboxylic acid that is the material for component (a4) above is preferably a combination of one or more aliphatic polycarboxylic acids and one or more aromatic polycarboxylic acids, and it is preferable to use sebacic acid and isophthalic acid in combination.

[0058] When the polycarboxylic acid that is the material for component (a4) above is a mixture of aliphatic polycarboxylic acid and aromatic polycarboxylic acid, the ratio of aliphatic polycarboxylic acid to aromatic polycarboxylic acid used ([aliphatic polycarboxylic acid / aromatic polycarboxylic acid]) is preferably 10 / 90 to 50 / 50 (equivalent ratio).

[0059] The proportion (amount used) of component (a4) in the polyol (A) can be in the range of 0% to 30% by mass of the total amount (100% by mass) of polyol (A). In particular, from the viewpoint of improving compatibility with other polyols and obtaining a moisture-permeable film with excellent adhesive strength, moisture permeability, and flexibility, a range of 5% to 30% by mass and a range of 5% to 20% by mass per 100% by mass of the total amount of polyol (A) is preferred.

[0060] The polyol (A) described above may contain, in addition to component (a1) above, one or more polyols (a5) having three hydroxyl groups (hereinafter sometimes referred to as component (a5)) as an optional component. Polyol (a5) having three hydroxyl groups is a component other than components (a1) to (a4) above. By further including polyol (a5) having three hydroxyl groups in polyol (A), the urethane prepolymer forms a cross-linked structure, further improving the balance between the mechanical strength and breathability of the resulting moisture-permeable film. Component (a5) is not included in components (a1) to (a4) above.

[0061] As component (a5) above, for example, compounds having an oxyalkylene group such as glycerin, trimethylolpropane; polyoxypropylene triol; polymers of glycerin and propylene oxide; and polymers of polyoxypropylene triol and ethylene oxide can be used. These may be used alone or in combination of two or more. In particular, polyols having an oxyalkylene group are preferred as component (a5) above, and polyoxypropylene triol is more preferred, as they have good compatibility with other polyol components such as component (a1), and the resulting moisture permeability and mechanical strength can be improved.

[0062] The number-average molecular weight of component (a5) above (particularly a polyol having three hydroxyl groups containing oxyalkylene groups) is preferably in the range of 300 to 800, as this allows for good compatibility with other polyol components such as component (a1), and enables the production of a moisture-permeable film with even better moisture permeability and mechanical strength. The number-average molecular weight of component (a5) above is measured using the same measurement method as that used for the number-average molecular weight of component (a1).

[0063] The proportion (amount used) of component (a5) in the polyol (A) can be in the range of 0 to 10 parts by mass of the total amount (100% by mass) of polyol (A). In particular, it is preferable that the proportion is in the range of 0.01% to 10% by mass of the total amount (100% by mass) of polyol (A), more preferably 0.1% to 7% by mass, and even more preferably 0.3% to 5% by mass, as this shows good compatibility with polyol (A) and improves the moisture permeability and mechanical strength of the resulting moisture-permeable film.

[0064] In addition to the above-mentioned component (a1), the polyol (A) may contain one or more other polyols (a6) other than components (a1) to (a5) as an optional component. Examples of the above-mentioned other polyols (a6) include polyester polyols, polyoxypropylene glycols, polyoxytetramethylene glycols, polyacrylic polyols, polycarbonate polyols, polybutadiene polyols, etc. These polyols may be used individually or in combination of two or more.

[0065] The proportion (content) of the oxyethylene structure (EO skeleton: -OCCO-) in the above polyol (A) is preferably in the range of 5 mol / kg to 40 mol / kg, more preferably in the range of 8 mol / kg to 30 mol / kg, and even more preferably in the range of 10 mol / kg to 25 mol / kg. When the proportion of the oxyethylene structure in the above polyol (A) is within the above range, even thin films of less than 30 μm can exhibit high moisture permeability at a usable level, and a moisture-permeable film with excellent mechanical strength and texture can be produced. It is preferable that the proportion (content) of the oxyethylene structure (EO skeleton: -OCCO-) in the above polyol (A) is 10 mol / kg or more, because even thin films with a thickness of 20 μm or less (especially 15 μm or less) can exhibit high moisture permeability and mechanical strength. Since the above oxyethylene structure is supplied from component (a1), the content of the above oxyethylene structure can be appropriately determined by adjusting component (a1).

[0066] The polyol (A) above contains at least component (a1), but in a preferred embodiment, it is preferable to contain component (a1) and at least one component from the group consisting of component (a2), component (a3), and component (a5), and in particular it is preferable to contain at least component (a1) and component (a3), and it is even more preferable to contain all four components (a1), (a2), (a3), and (a5), because a moisture-permeable film that exhibits good moisture permeability can be produced even in thin films of 20 μm or less.

[0067] -Polyisocyanate (B)- Examples of polyisocyanates (B) include aromatic polyisocyanates such as polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate (e.g., 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, etc.), carbodiimide-modified diphenylmethane diisocyanate isocyanate, xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, etc.; and aliphatic or alicyclic polyisocyanates such as hexamethylene diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate, etc. These polyisocyanates may be used alone or in combination of two or more. Among these, aromatic polyisocyanates are preferred because they offer good reactivity and mechanical strength, and diphenylmethane diisocyanate is even more preferred because of its low vapor pressure during heating and melting.

[0068] The proportion (amount used) of the above polyisocyanate (B) in the total mass of the raw materials (solids) constituting the urethane prepolymer is preferably in the range of 5% to 40% by mass, and more preferably in the range of 10% to 30% by mass.

[0069] -Urethane prepolymer- The above urethane prepolymer is obtained by reacting raw materials that include at least the above polyol (A) and the above polyisocyanate (B). In particular, the above urethane prepolymer is a reaction product of polyol (A) containing the above components (a1), (a2), (a3), and (a5) and the above polyisocyanate (B), and the proportion of the above component (a1) in the above polyol (A) is 50% by mass or more, because it can be coated thinly onto a release substrate without a solvent and with low melt viscosity, and even if the thin film is less than 30 μm thick (preferably 20 μm or less), it is possible to form a coating film with high moisture permeability without the occurrence of coating defects.

[0070] The above-mentioned urethane prepolymer may have ethylenically unsaturated double bond groups as terminal functional groups at both or one of its ends, in addition to isocyanate groups. Examples of ethylenically unsaturated double bond groups include vinyl groups, allyl groups, and (meth)acrylic groups. A urethane prepolymer having ethylenically unsaturated double bond groups as terminal functional groups can be prepared, for example, by reacting an acrylate compound (e.g., a hydroxyl group-containing (meth)acrylate) with a urethane prepolymer having two or more isocyanate groups per molecule at the molecular ends.

[0071] The softening point of the above-mentioned urethane prepolymer is preferably in the range of 40 to 120°C. If the softening point of the above-mentioned urethane prepolymer is within this range, the moisture-curing urethane hot-melt resin composition will have good continuous coating properties and excellent adhesive strength, so a film-like coating can be easily formed on a release substrate, and an adherend such as a base fabric can be firmly adhered to the coating. In this specification, the softening point refers to the temperature at which the urethane prepolymer begins to flow due to heat and loses its cohesive force when its temperature is gradually increased, and specifically refers to the value obtained by the ring-and-ball method (JIS K-6301).

[0072] As a method for producing the above-mentioned urethane prepolymer, for example, the components of the polyol (A) are added to a reaction vessel containing the polyisocyanate (B), mixed, 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).

[0073] When producing the above-mentioned urethane prepolymer, the equivalent ratio (NCO / OH) of the isocyanate group (NCO) of the polyisocyanate (B) to the hydroxyl group (OH) of the polyol (A) is preferably in the range of 1.1 to 5.0, and more preferably in the range of 1.5 to 3.0, in order to lower the melt viscosity of the heated and melted moisture-curable urethane hot-melt resin composition and to produce a moisture-permeable film with excellent mechanical strength.

[0074] The isocyanate group content (hereinafter abbreviated as "NCO%") of the above urethane prepolymer is preferably in the range of 1.7 to 5, and more preferably in the range of 2.0 to 4.5. Having the NCO% of the above urethane prepolymer within this range allows for a lower melt viscosity of the heated and melted moisture-curable urethane hot-melt resin composition, enabling smooth continuous coating and easy formation of thin, thick coating films free from defects such as streaks, repellency, and pinholes. Furthermore, it can increase the mechanical strength of the moisture-permeable film, which is the cured product of the moisture-curable urethane hot-melt resin composition. The NCO% of the above urethane prepolymer is the value measured by potentiometric titration in accordance with JIS K1603-1:2007.

[0075] The NCO gram equivalent of the above urethane prepolymer is preferably in the range of 700 to 3000, and more preferably in the range of 800 to 2500, and even more preferably in the range of 900 to 2200, from the viewpoint of preventing the occurrence of coating defects even when forming a coating film of a moisture-curing urethane hot-melt resin composition with a thickness of 20 μm or less. By having the NCO gram equivalent of the above urethane prepolymer within the above range, the number-average molecular weight of the urethane prepolymer can be reduced, and the melt viscosity of the heated and melted moisture-curing urethane hot-melt resin composition can be reduced. This makes it easier to form a thin film without coating defects. The NCO gram equivalent of the above urethane prepolymer is the value obtained by dividing the total value of all polyol components and isocyanate components that are materials of the urethane prepolymer by the value obtained by subtracting the polyol equivalent from the isocyanate equivalent.

[0076] The number-average molecular weight of the above urethane prepolymer is preferably in the range of 500 to 30000 from the viewpoint of the fluidity of the heated and melted moisture-curable urethane hot-melt resin composition. In particular, when applying the moisture-curable urethane hot-melt resin composition to form a coating film with a thickness of less than 30 μm, more preferably 20 μm or less, the melt viscosity of the moisture-curable urethane hot-melt resin composition can be lowered, and the occurrence of coating film defects can be suppressed, so the range of 700 to 20000 is more preferable, and the range of 1000 to 15000 is even more preferable. The number-average molecular weight of the above urethane prepolymer is a value measured by the same measurement method as the number-average molecular weight of component (a1) above.

[0077] The above moisture-curing urethane hot melt resin composition contains the above urethane prepolymer as an essential component, but may also contain other additives as needed. Examples of these other additives include tackifiers, curing catalysts, antioxidants, plasticizers, stabilizers, fillers, dyes, pigments, fluorescent whitening agents, silane coupling agents, thixotropic agents, waxes, fluorescent whitening agents, thermoplastic resins, thermosetting resins, dyes, conductivity enhancers, antistatic agents, moisture permeability enhancers, water repellents, oil repellents, hollow foams, water-containing compounds, flame retardants, water absorbents, moisture absorbents, deodorants, foam stabilizers, defoamers, mold inhibitors, preservatives, algaecides, pigment dispersants, inert gases, blocking inhibitors, hydrolysis inhibitors, etc. These may be used individually or in combination of two or more.

[0078] From the viewpoint of being able to be continuously coated well in a heated and molten state and to form a film-like coating, the above moisture-curing urethane hot-melt resin composition preferably has a melt viscosity at 120°C in the range of 100 to 10,000 mPa·s. In particular, from the viewpoint of suppressing the occurrence of coating defects when applying the moisture-curing urethane hot-melt resin composition to form a thin coating with a thickness of less than 30 μm (more preferably 20 μm or less), the melt viscosity at 120°C is more preferably in the range of 200 to 5,000 mPa·s, even more preferably in the range of 300 to 4,000 mPa·s, and particularly preferably in the range of 400 to 3,000 mPa·s. The melt viscosity of the moisture-curing urethane hot-melt resin composition can be adjusted by the average molecular weight of the urethane prepolymer, the isocyanate group content of the urethane prepolymer, etc.

[0079] -Process X1- In step 1 described above, the moisture-curing polyurethane hot melt resin composition is applied to the release substrate without using a solvent. In step X1, the heating and melting temperature of the moisture-curing polyurethane hot melt resin composition is preferably in the range of 50°C to 130°C, and more preferably in the range of 80°C to 120°C.

[0080] The method for applying the above moisture-curing polyurethane hot melt resin composition onto a release substrate is not particularly limited as long as it is possible to form a film-like coating on the release substrate by continuous application, and examples include the roll coating method, extrusion method, gravure coating method, die coating method, bar coating method, knife coating method, etc.

[0081] The thickness of the coating film of the above moisture-curing polyurethane hot melt resin composition is not particularly limited as long as it is thin and can exhibit high moisture permeability, provided it is less than 30 μm. However, from the viewpoint of making it a thinner film and suppressing a decrease in moisture permeability, a thickness of 20 μm or less is more preferable. More specifically, the thickness of the coating film is preferably 3 μm to 29 μm, more preferably 5 μm to 27 μm, even more preferably 7 μm to 25 μm, and particularly preferably 9 μm to 23 μm.

[0082] 2.Process X2 In step X2 described above, the coating film is cured at least by moisture to form a moisture-permeable film which is a cured product of the moisture-curable polyurethane hot-melt resin composition. In the method for manufacturing a moisture-permeable film according to this disclosure, since the moisture-curable polyurethane hot-melt resin composition applied to the release substrate does not contain a solvent, the thickness of the coating film after curing is the same as the thickness of the coating film in step X1.

[0083] The coating film of the above moisture-curing urethane hot melt resin composition hardens by reacting with moisture contained in the air or in the object in contact with the coating film (for example, a release substrate or the adherend described in "II. Laminates" below), and this hardened film becomes a moisture-permeable film. In particular, it is preferable to mature the coating film in step X2 above, as this allows the curing reaction of the coating film to proceed sufficiently. The maturation conditions for the coating film can be, for example, an ambient temperature of 20°C to 40°C, a relative humidity of 50% to 80%, and a maturation period of 1 to 5 days (more typically 3 days). The maturation of the coating film is carried out on a release substrate. Generally, the maturation of the coating film is carried out with the release substrate on which the coating film has been formed wound up on a roll or the like, but it may also be carried out without winding. Furthermore, the curing reaction of the coating film may begin from the time the moisture-curing urethane hot melt resin composition is applied to the release substrate in step X1 above.

[0084] Step X2 described above may include an operation to peel off the release substrate from the moisture-permeable film. After curing the coating film of the moisture-curing polyurethane hot-melt resin composition to form a moisture-permeable film, a single layer of the moisture-permeable film is obtained by peeling off the release substrate from the moisture-permeable film.

[0085] If the urethane prepolymer contained in the above moisture-curing polyurethane hot melt resin composition has ethylenically unsaturated double bond groups at both or one end, the coating film may be further irradiated with active energy rays in step X2. This is because, in addition to curing the coating film of the moisture-curing polyurethane hot melt resin composition with moisture, the curing reaction can be further advanced by irradiation with active energy rays.

[0086] Examples of active energy rays include ultraviolet light. The irradiation dose of active energy rays is not particularly limited as long as it is sufficient to adequately advance the curing reaction of the coating film of the moisture-curing polyurethane hot melt resin composition, but for example, 50 mJ / cm². 2 ~5000 mJ / cm 2 Preferably, 100 mJ / cm²2 ~3000 mJ / cm 2 is more preferable. The above irradiation dose is based on the value measured in the wavelength range of 300 to 390 nm using a UV checker UVR-N1 (manufactured by Nippon Battery Co., Ltd.). As a light source for irradiating active energy rays, known lamps such as xenon lamps, xenon-mercury lamps, metal halide lamps, high-pressure mercury lamps, and low-pressure mercury lamps can be mentioned.

[0087] The timing of irradiating the coating film of the above moisture-curable polyurethane hot melt resin composition with active energy rays is not particularly limited, but it is preferable to perform it immediately before winding the release substrate on which the above coating film is formed around a roll or the like from the viewpoint of preventing deterioration of the surface quality. Further, the moisture-curing reaction and the photocuring reaction by irradiation of active energy rays may proceed simultaneously, or either one of the curing reactions may proceed first and then the other curing reaction may proceed.

[0088] 3. Moisture-permeable film The moisture-permeable film obtained by the method for producing a moisture-permeable film of the present disclosure has a thickness of less than 30 μm, and preferably 20 μm or less from the viewpoint of being able to exhibit high moisture permeability with a thin thickness. More specifically, the thickness of the above moisture-permeable film is preferably 3 μm or more and 29 μm or less, more preferably 5 μm or more and 27 μm or less, still more preferably 7 μm or more and 25 μm or less, and particularly preferably 9 μm or more and 23 μm or less.

[0089] Further, the moisture-permeable film obtained by the method for producing a moisture-permeable film of the present disclosure exhibits practical-level moisture permeability performance, so the moisture permeability is 4000 (g / m 2 / 24 h) or more. The moisture permeability of the moisture-permeable film is a value measured in accordance with the B-1 method (potassium acetate method) of JIS L1099:2012.

[0090] The moisture-permeable film obtained by the method for producing a moisture-permeable film of the present disclosure may be in a state peeled from the release substrate, or a release substrate may be laminated on one side of the moisture-permeable film, and it may be in a state where the release substrate is peeled off during use.

[0091] Furthermore, the moisture-permeable film obtained by the method for manufacturing a moisture-permeable film according to this disclosure may have a release film or release paper on the main surface of the moisture-permeable film opposite to the surface that is bonded to the release substrate. The release film or release paper can be peeled off when using the moisture-permeable film. The method for manufacturing a moisture-permeable film having a release film or release paper, and the release film or release paper, are the same as the method for manufacturing a laminate when the adherend is a release film, and the release film or release paper exemplified as the adherend, as described in the section "II. Method for Manufacturing a Laminate" below, so the explanation here is omitted.

[0092] II. Method for Manufacturing Laminates The present disclosure is a method for manufacturing a laminate comprising a moisture-permeable film and an adherend in direct contact with one side of the moisture-permeable film, comprising: step Y1: heating and melting a moisture-curable polyurethane hot-melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) with a polyisocyanate (B); and continuously applying the heated and melted moisture-curable polyurethane hot-melt resin composition onto the first main surface of a release substrate having an arithmetic mean height Sa of at least 0.90 μm and / or a gloss of 25.0 or less to form a coating film with a thickness of less than 30 μm; and step Y2: contacting the surface of the adherend to the surface of the coating film and bonding them, and at least moisture-curing the coating film to form a moisture-permeable film which is a cured product of the moisture-curable polyurethane hot-melt resin composition, wherein the permeability of the moisture-permeable film is 4000 (g / m²). 2 It is 24 hours or longer.

[0093] Conventional methods for manufacturing laminates having a moisture-permeable film involve intermittently applying an adhesive to at least one surface of the moisture-permeable film and adhering a substrate such as a moisture-permeable material to the adhesive-coated surface. However, this method results in a structure of at least three layers: the moisture-permeable film, the intermittently applied adhesive, and the substrate, which presents challenges such as a complicated process and difficulty in manufacturing thin laminates. Furthermore, when using a material other than a release film or release paper as the substrate to be joined to the moisture-permeable film, the interlayer adhesion between the moisture-permeable film and the substrate is not sufficiently obtained, and the overall moisture permeability of the laminate decreases, among other problems, because the moisture-permeable film and the substrate are intermittently bonded with the adhesive.

[0094] In contrast, according to the method for manufacturing a laminate of this disclosure, a moisture-curing polyurethane hot-melt resin composition is continuously applied to a predetermined release substrate to form a coating film, and the cured product of the coating film functions as both an adhesive layer and a moisture-permeable film. This eliminates the need to use a separate adhesive for bonding with the adherend, and reduces the number of layers in the laminate. Furthermore, according to the method for manufacturing a laminate of this disclosure, the moisture-curing polyurethane hot-melt resin composition can be applied in a thin thickness of less than 30 μm (more preferably 20 μm or less) without using a solvent, and defects such as repellency and pinholes can be prevented from occurring in the coating film or the moisture-permeable film which is the cured product of the coating film. As a result, a thin, highly moisture-permeable film is formed on the adherend, enabling the laminate to be made thinner. Moreover, when a member other than a release film or release paper is used as the adherend to be bonded with the moisture-permeable film, the moisture-permeable film and the adherend can be directly and sufficiently bonded without using another adhesive, thereby increasing the interlayer adhesion strength of the laminate.

[0095] 1.Process Y1 Step Y1 described above is a step of heating and melting a moisture-curing polyurethane hot melt resin composition containing a predetermined urethane prepolymer, and continuously applying the heated and melted moisture-curing polyurethane hot melt resin composition onto the first main surface of a release substrate having an arithmetic mean height Sa of at least 0.90 μm and / or a gloss level of 25.0 or less, to form a coating film with a thickness of less than 30 μm.

[0096] Step Y1 described above is the same as the one described in "I. Method for Manufacturing a Moisture-Permeable Film 1. Step X1" above, but with step X1 replaced by step Y1, so its explanation is omitted here. Furthermore, the moisture-curing polyurethane hot melt resin composition used in step Y1 is the same as the moisture-curing polyurethane hot melt resin composition described in "I. Method for Manufacturing a Moisture-Permeable Film 1. Step X1" above.

[0097] 2.Process Y2 Step Y2 described above is a step in which the surface of the adherend is brought into contact with the surface of the coating film and bonded together, and the coating film is at least moisture-cured to form a moisture-permeable film which is a cured product of the moisture-curing polyurethane hot-melt resin composition. In step Y2, with the adherend bonded to the coating film of the moisture-curing polyurethane hot-melt resin composition, the coating film hardens to become a moisture-permeable film, thereby enabling the production of a laminate in which the adherend and the moisture-permeable film are directly bonded.

[0098] In step Y2 described above, an adherend is typically bonded to a coating of moisture-curing polyurethane hot-melt resin composition on a release substrate. The adherend bonded to the coating of moisture-curing polyurethane hot-melt resin composition in step Y2 is not particularly limited and can be, for example, a base fabric, a resin film, or release paper. The adherend is typically bonded before the coating is completely cured.

[0099] The base fabric material can be, for example, chemical fibers such as polyester fibers, nylon fibers, acrylic fibers, polyurethane fibers, acetate fibers, rayon fibers, and polylactic acid fibers; or cotton, linen, silk, wool, or blends thereof. The base fabric may also be a nonwoven fabric, woven fabric, knitted fabric, etc.

[0100] The above-mentioned resin film can be appropriately selected according to the desired function, and examples include breathable films and release films. Examples of breathable films include resin films obtained using solvent-based and water-based polyurethane resins, thermoplastic polyurethane resins (TPU), thermoplastic polyester resins (TPE), porous polytetrafluoroethylene (PTFE), and polyolefin resins such as polyethylene and polypropylene. Examples of release films include general-purpose resin films such as polyethylene films and PET films. Examples of release paper include those in which a release agent is coated on the surface of a paper base material, and commercially available and general-purpose products can be used.

[0101] In step Y2 described above, the adherend is placed on and / or pressed onto the coating of the moisture-curing polyurethane hot-melt resin composition, and then compressed and cured using a conventionally known method. As a result, the coating undergoes a curing reaction in direct contact with the adherend, becoming a moisture-permeable film. This yields a laminate in which the moisture-permeable film is directly bonded to one side of the adherend. The curing conditions for the coating in step Y2 are the same as those described in "I. Method for Manufacturing Moisture-Permeable Film 2. Step X2" above, so a detailed explanation is omitted here.

[0102] Furthermore, if the urethane prepolymer contained in the moisture-curing polyurethane hot melt resin composition has ethylenically unsaturated double bond groups at both or one end, the coating film may be further irradiated with active energy rays in step Y2.

[0103] In step Y2 described above, the process is the same as described in "I. Method for Manufacturing a Moisture-Permeable Film 2. Step X2" above, except that step X2 is replaced with step Y2, so the explanation is omitted here. Furthermore, the moisture-permeable film formed in step Y2 exhibits high moisture permeability at a practical level, with a moisture permeability of 4000 g / m². 2 It is sufficient if it is 24 hours or longer.

[0104] Step Y2 described above may include an operation to peel off and remove the release substrate from the moisture-permeable film.

[0105] In the method for manufacturing a laminate according to the present disclosure, if the adherend bonded to the coating film in step Y2 is a release film or release paper, the method may include step Y3 after step Y2, in which the adherend is peeled off, an adhesive is applied to a moisture-permeable film (referred to as the first moisture-permeable film), and another moisture-permeable film (referred to as the second moisture-permeable film) is bonded to it. In step Y3, it is preferable to apply the adhesive intermittently.

[0106] The second moisture-permeable film bonded via an adhesive in step Y3 may be a moisture-permeable film (referred to as moisture-permeable film A) manufactured by a manufacturing method including steps Y1 and Y2, or a moisture-permeable film (referred to as moisture-permeable film B) manufactured by a method other than the manufacturing method including steps Y1 and Y2.

[0107] Examples of laminates obtained by the manufacturing method of the laminate of this disclosure include the following laminate configuration. Note that moisture-permeable film A represents a moisture-permeable film manufactured by the manufacturing method including steps Y1 and Y2, and moisture-permeable film B represents a moisture-permeable film manufactured by a method other than the manufacturing method including steps Y1 and Y2. Note that the components enclosed in parentheses "()" may or may not be included in the configuration of the laminate. (Release substrate) / Moisture-permeable film A / Base fabric (Release substrate) / Moisture-permeable film A / Resin film (Release substrate) / Moisture-permeable film A / Release film (Release substrate) / Moisture-permeable film A / Adhesive layer / Moisture-permeable film A / (Release substrate) (Release substrate) / Moisture-permeable film A / Adhesive layer / Moisture-permeable film B

[0108] The applications of the laminates obtained by the manufacturing method of the laminates disclosed herein are not particularly limited, but they can be used for sportswear, raincoats, gloves, shoes, fire suits, military uniforms, bandage films, diaper films, wall materials, roofing materials, etc.

[0109] III. Breathable Film The moisture-permeable film of this disclosure is made from a cured product of a moisture-curable polyurethane hot-melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) with a polyisocyanate (B), has a thickness of less than 30 μm and a transmittance of 4000 g / m². 2 It is 24 hours or longer.

[0110] The moisture-curing polyurethane hot-melt resin composition constituting the moisture-permeable film of this disclosure is the same as the details of the moisture-curing polyurethane hot-melt resin composition described in section I. Method for producing a moisture-permeable film above.

[0111] The moisture-permeable film of this disclosure has a thickness of less than 30 μm, and is preferably 20 μm or less from the viewpoint of being thin and exhibiting high moisture permeability. More specifically, the thickness of the moisture-permeable film is preferably 3 μm to 29 μm, more preferably 5 μm to 27 μm, even more preferably 7 μm to 25 μm, and particularly preferably 9 μm to 23 μm. Because the thickness of the moisture-permeable film of this disclosure is within the above range, it is a thin film that does not develop defects, has excellent surface quality, and exhibits high moisture permeability.

[0112] The moisture permeability of the moisture-permeable film of this disclosure can be the same as the preferred range of moisture permeability of the moisture-permeable film described in section I. Method for manufacturing a moisture-permeable film above.

[0113] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and produces similar effects is included within the technical scope of this disclosure. [Examples]

[0114] The abbreviations for each material used in the preparation of the urethane prepolymer are shown below.

[0115] <Polyol (A)> <<Polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) component>> • PEt-1: Polyoxyethylene glycol (number average molecular weight Mn; 1540, hydroxyl group equivalent (gram equivalent eq. wt); 770) • PEt-2: Polyoxyethylene glycol (number average molecular weight Mn; 2000, hydroxyl group equivalent (gram equivalent eq. wt); 1000) • PEt-3: Polyoxyethylene glycol (number average molecular weight Mn; 4000, hydroxyl group equivalent (gram equivalent eq. wt); 1550) • PEt-4: Polyoxyethylene glycol (number average molecular weight Mn; 6000, hydroxyl group equivalent (gram equivalent eq. wt); 4400) • PEt-5: Polyoxyethylene glycol (number average molecular weight Mn; 11000, hydroxyl group equivalent (gram equivalent eq. wt); 5500)

[0116] <<Aromatic polyester polyol (a2) component>> • PEs-1: Polyester polyol (reaction product of orthophthalic acid and 1,6-hexanediol, number average molecular weight Mn; 2900, hydroxyl group equivalent (gram equivalent eq. wt); 1000) PEs-2: Polyester polyol (reaction product of neopentyl glycol, diethylene glycol, and orthophthalic acid; number average molecular weight: 2913; hydroxyl group equivalent (gram equivalent eq. wt): 500)

[0117] <<Crystalline polyester polyol (a3) ​​component>> • PEs-3: Polyester polyol (reaction product of ethylene glycol, neopentyl glycol, 1,6-hexanediol, and adipic acid; number average molecular weight Mn; 2570; hydroxyl group equivalent (gram equivalent eq. wt); 2750) PEs-4; Polyester polyol (reaction product of 1,6-hexanediol and sebacic acid, number-average molecular weight Mn; 2523, hydroxyl group equivalent (gram equivalent eq. wt); 1750)

[0118] <Polyol component (a5) having three hydroxyl groups> • PO-1: Polyoxypropylene triol (T-700, manufactured by Mitsui Chemicals, Inc., number average molecular weight Mn: 700, hydroxyl group equivalent (gram equivalent eq. wt): 233)

[0119] <Polyisocyanate (B)> MDI: 4,4'-diphenylmethane diisocyanate

[0120] [Preparation of moisture-curing polyurethane hot melt resin composition] (Moisture-curing polyurethane hot melt resin composition (1)) In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 173.4 parts by mass of "PEt-1", 20.4 parts by mass of "PEs-2", 7.1 parts by mass of "PEs-4", and 3.1 parts by mass of "PO-1" were added and mixed. The mixture was then heated under reduced pressure at 100°C until the moisture content in the flask was reduced to 0.05% by mass or less. Next, the contents of the flask were cooled to 90°C, and 61.4 parts by mass of "MDI" melted at 70°C were added. The mixture was reacted at 110°C for approximately 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, thereby preparing a hot-melt urethane prepolymer (i) and a solvent-free moisture-curing polyurethane hot-melt resin composition (1).

[0121] (Moisture-curing polyurethane hot melt resin compositions (2) to (8)) Hot melt urethane prepolymers (ii) to (viii) were prepared in the same manner as in Example 1, except that the type and amount of polyol (A), polyisocyanate (B), and compound (C) were changed as shown in Table 1 below, to obtain solvent-free moisture-curing polyurethane hot melt resin compositions (2) to (8).

[0122] [Table 1]

[0123] [Example 1-1] A solvent-free, moisture-curing polyurethane hot-melt resin composition (1), heated and melted at 100°C, was continuously applied to the surface of a release substrate A (polyolefin-based release paper, arithmetic mean height Sa; 1.024 μm, gloss (60° gloss value); 4.7) using a roll coater to form a coating film with a thickness of 15 μm. Next, the coating film was cured at a temperature of 23°C and a humidity of 50±5% for 24 hours or more to obtain a moisture-permeable film (1-1), which is the cured product of the coating film.

[0124] [Examples 1-2 to 1-7] A moisture-permeable film was obtained in the same manner as in Example 1-1, except that moisture-curing polyurethane hot-melt resin compositions (2) to (7) were used instead of moisture-curing polyurethane hot-melt resin composition (1).

[0125] [Comparative Example 1-1] A moisture-permeable film was obtained in the same manner as in Example 1-1, except that moisture-curing polyurethane hot-melt resin composition (8) was used instead of moisture-curing polyurethane hot-melt resin composition (1).

[0126] [Example 2-1] A solvent-free, moisture-curable polyurethane hot-melt resin composition (1), heated and melted at 100°C, was continuously applied to the surface of a release substrate B (polyolefin-based release paper, arithmetic mean height Sa; 1.103 μm, gloss (60° gloss value); 14.5) using a roll coater to form a coating film with a thickness of 15 μm. Next, the coating film was aged for 24 hours or more under conditions of 23°C and 50±5% humidity to obtain a moisture-permeable film (2-1), which is the cured product of the coating film.

[0127] [Examples 2-2 to 2-7] A moisture-permeable film was obtained in the same manner as in Example 2-1, except that moisture-curing polyurethane hot-melt resin compositions (2) to (7) were used instead of moisture-curing polyurethane hot-melt resin composition (1).

[0128] [Comparative Example 2-1] A moisture-permeable film was obtained in the same manner as in Example 2-1, except that moisture-curing polyurethane hot-melt resin composition (8) was used instead of moisture-curing polyurethane hot-melt resin composition (1).

[0129] [Comparative Example 3-1] A solvent-free moisture-curing polyurethane hot-melt resin composition (1), heated and melted at 100°C, was continuously applied to the surface of a release substrate C (silicone-based release paper, arithmetic mean height Sa; 0.898 μm, gloss (60° gloss value); 26.3) using a roll coater to form a coating film with a thickness of 15 μm. Next, the coating film was aged for 24 hours or more under conditions of 23°C and 50±5% humidity to obtain a moisture-permeable film (3-1), which is the cured product of the coating film.

[0130] [Comparative Examples 3-2 to 3-8] A moisture-permeable film was obtained in the same manner as in Comparative Example 3-1, except that moisture-curing polyurethane hot-melt resin compositions (2) to (8) were used instead of moisture-curing polyurethane hot-melt resin composition (1).

[0131] 〔evaluation〕 <Presence or absence of coating defects> In the examples and comparative examples, the appearance of the heat-melted moisture-curable polyurethane hot-melt resin composition after being fully coated onto a release substrate was visually evaluated and judged according to the following criteria. ○: No defects such as creases, imperfections, or pinholes. ×: Has defects such as slits, imperfections, and pinholes.

[0132] <Strength> Test pieces were cut from the moisture-permeable films manufactured in the examples and comparative examples into strips 5 mm wide and 50 mm long. Tensile tests were performed using a precision universal testing machine (Autograph "AG-NX" manufactured by Shimadzu Corporation) under the following conditions: chuck distance of 40 mm, tensile speed of 10 mm / sec, temperature of 23°C, and humidity of 50 ± 5%. The stress at 100% elongation was measured, and the mechanical strength of the moisture-permeable films was determined according to the following criteria. ○: 8MPa or less ×: Over 8MPa

[0133] <Texture (Flexibility)> The moisture-permeable films produced in the examples and comparative examples were folded by hand and evaluated on the following five-point scale. A score of 3 or lower on the five-point scale is practically preferable. 1: Very soft 2: Slightly soft 3: Soft 4: A little hard 5: Hard

[0134] <Moisture permeability> The moisture permeability of the moisture-permeable films produced in the examples and comparative examples was measured in accordance with JIS L1099 (A-1: Calcium Chloride Method). Note that the moisture-permeable films obtained in Comparative Examples 3-1 to 3-8 showed abnormally high moisture permeability values ​​(10,000 g / m²) due to coating defects. 2 The time elapsed (more than 24 hours) was deemed "unmeasurable".

[0135] The evaluation results are shown in the table below.

[0136] [Table 2]

[0137] Table 3

[0138] Table 4

Claims

1. Step X1: A moisture-curing polyurethane hot-melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) with a polyisocyanate (B) is heated and melted, and the heated and melted moisture-curing polyurethane hot-melt resin composition is continuously applied to the first main surface of a release substrate having an arithmetic mean height Sa of at least 0.90 μm and / or a gloss of 25.0 or less, to form a coating film with a thickness of less than 30 μm. Step X2 involves at least moisture curing the coating to form a moisture-permeable film which is a cured product of the moisture-curing polyurethane hot-melt resin composition, It has, The permeability of the aforementioned moisture-permeable film is 4000 (g / m²). ２ A method for manufacturing a moisture-permeable film that is 24 hours or longer.

2. The method for producing a moisture-permeable film according to claim 1, wherein the polyol (A) further comprises a crystalline polyester polyol (a3).

3. The method for producing a moisture-permeable film according to claim 1, wherein the polyol (A) further comprises a polyol (a5) having three hydroxyl groups.

4. The method for producing a moisture-permeable film according to claim 1, wherein the melt viscosity of the moisture-curing urethane hot-melt resin composition at 120°C is in the range of 100 to 10,000 mPa·s.

5. A method for producing a moisture-permeable film according to claim 1, wherein the proportion of polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) in the polyol (A) is 50% by mass or more of the total amount (100% by mass) of the polyol (A).

6. The method for producing a moisture-permeable film according to claim 1, wherein the proportion of oxyethylene structures in the polyol (A) is 10 mol / kg or more.

7. A method for manufacturing a laminate having a moisture-permeable film and an adherend that is in direct contact with one side of the moisture-permeable film, Step Y1 involves heating and melting a moisture-curing polyurethane hot-melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) with a polyisocyanate (B), and continuously applying the heated and melted moisture-curing polyurethane hot-melt resin composition onto the first main surface of a release substrate having an arithmetic mean height Sa of at least 0.90 μm and / or a gloss level of 25.0 or less, to form a coating film with a thickness of less than 30 μm. Step Y2 involves bringing the surface of the adherend into contact with the surface of the coating film and bonding them, and at least moisture-curing the coating film to form a moisture-permeable film which is a cured product of the moisture-curing polyurethane hot-melt resin composition. It has, The permeability of the aforementioned moisture-permeable film is 4000 (g / m²). ２ A method for manufacturing a laminate, wherein the time is 24 hours or longer.

8. The method for manufacturing a laminate according to claim 7, wherein the adherend is a base fabric.

9. The method for manufacturing a laminate according to claim 7, wherein the adherend is a release film or release paper.

10. The method for producing a laminate according to claim 7, wherein the polyol (A) further comprises a crystalline polyester polyol (a3).

11. The method for producing a laminate according to claim 7, wherein the polyol (A) further comprises a polyol (a5) having three hydroxyl groups.

12. The method for producing a laminate according to claim 7, wherein the melt viscosity of the moisture-curing urethane hot-melt resin composition at 120°C is in the range of 100 to 10,000 mPa·s.

13. The method for producing a laminate according to claim 7, wherein the proportion of polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) in the polyol (A) is 50% by mass or more of the total amount (100% by mass) of the polyol (A).

14. The method for producing a laminate according to claim 7, wherein the proportion of oxyethylene structures in the polyol (A) is 10 mol / kg or more.

15. It consists of a cured product of a moisture-curing polyurethane hot-melt resin composition containing a urethane prepolymer obtained by reacting a polyol (A) containing polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) with a polyisocyanate (B), The thickness is less than 30 μm, and the transmittance is 4000 (g / m²). ２ A breathable film with a moisture permeability of 24 hours or more.

16. The moisture-permeable film according to claim 15, wherein the polyol (A) further comprises a crystalline polyester polyol (a3).

17. The moisture-permeable film according to claim 15, wherein the polyol (A) further comprises a polyol (a5) having three hydroxyl groups.

18. The moisture-permeable film according to claim 15, wherein the proportion of polyethylene glycol and / or polyoxyethylene polyoxypropylene glycol (a1) in the polyol (A) is 50% by mass or more of the total amount (100% by mass) of the polyol (A).

19. The moisture-permeable film according to claim 15, wherein the proportion of oxyethylene structures in the polyol (A) is 10 mol / kg or more.

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