Polyurethane resin, moisture-permeable film, and moisture-permeable and waterproof fabric

Abstract

Provided is a polyurethane resin capable of producing a moisture-permeable film that is excellent in moisture permeability and also excellent in wash resistance, alcohol resistance, repeated coating suitability, heat resistance, light resistance, and softness. A polyurethane resin that is a reaction product of (i) a polyol component, (ii) a chain extender, and (iii) a polyisocyanate component. The (i) polyol component contains (i-1) a polyethylene glycol and (i-2) a polyether polyol, the (ii) chain extender contains 2 or more (ii-1) linear alkanediols having a carbon number of 2 to 4, the (iii) polyisocyanate component contains (iii-1) an aromatic diisocyanate and (iii-2) an aliphatic diisocyanate, and the polyurethane resin satisfies the following condition (1) or the like. Condition (1): The (ii) chain extender further contains (ii-3) a triol.

Description

Technical Field

[0001] This invention relates to polyurethane resins, breathable films, and breathable waterproof fabrics. Background Technology

[0002] Conventionally, as breathable materials used to construct fabrics exhibiting both breathability and water resistance (hereinafter also referred to as "breathable and waterproof fabrics"), microporous membranes made of fluoropolymers or polyurethane resins, and non-porous membranes made of hydrophilic resins have been used. In the case of microporous membranes, clogging due to sweat, dirt, etc., can sometimes reduce breathability. On the other hand, in the case of non-porous membranes made of hydrophilic resins, breathability does not decrease due to clogging. For example, polyurethane resins containing hydrophilic segments are used as the hydrophilic resins constituting non-porous membranes.

[0003] Breathable and waterproof fabrics, for example, have a three-layer structure consisting of a breathable outer skin layer, an adhesive layer, and a base fabric. Furthermore, the outer skin layer is constructed from a non-porous, breathable film formed of a hydrophilic polyurethane resin. It should be noted that, as related prior art, a hydrophilic polyurethane resin for breathable and waterproof fabrics has been proposed, which is obtained by reacting a hydrophilic polyol such as polyethylene glycol, a chain extender such as ethylene glycol, and an organic isocyanate (Patent Documents 1 and 2).

[0004] For a breathable membrane constituting a breathable and waterproof fabric, it is required not only to be breathable, but also to be washable, alcohol-resistant, light-resistant, and soft. It should be noted that when manufacturing a breathable and waterproof fabric with the aforementioned three-layer structure, solvent-based or moisture-curing adhesives are typically used to form the adhesive layer. Therefore, the breathable membrane also requires properties such as resistance to shrinkage even when coated with adhesive (so-called recoating suitability) and moderate heat resistance, preventing softening even when heated during bonding.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2003-201675

[0008] Patent Document 2: Japanese Patent Application Publication No. 10-17764 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] However, the breathable films formed using existing hydrophilic polyurethane resins as proposed in Patent Documents 1 and 2 exhibit a certain degree of breathability, but on the other hand, they may not be sufficient in terms of washability, alcohol resistance, suitability for repeated coating, heat resistance, light resistance, and flexibility, and there is room for further improvement.

[0011] The present invention was made in view of the problems of the prior art, and its object is to provide a polyurethane resin capable of producing a breathable film with excellent moisture permeability, as well as excellent washability, alcohol resistance, recoating suitability, heat resistance, light resistance and flexibility.

[0012] Furthermore, the present invention aims to provide: a breathable film obtained using the polyurethane resin, which has excellent moisture permeability, as well as excellent washability, alcohol resistance, suitability for repeated coating, heat resistance, light resistance and softness, and a breathable waterproof fabric having the breathable film.

[0013] Solution for solving the problem

[0014] That is, according to the present invention, a polyurethane resin as shown below is provided.

[0015] [1] A polyurethane resin comprising (i) a polyol component, (ii) a chain extender and (iii) a polyisocyanate component, wherein the (i) polyol component comprises (i-1) polyethylene glycol and (i-2) polyether polyols other than the aforementioned (i-1) polyethylene glycol, the (ii) chain extender comprises two or more (ii-1) linear alkanediols having 2 to 4 carbon atoms, or comprises (ii-2) linear, branched or cyclic alkanediols other than the aforementioned (ii-1) linear alkanediols having 2 to 4 carbon atoms, and the (iii) polyisocyanate component comprises (iii-1) an aromatic diisocyanate and (iii-2) an aliphatic diisocyanate, wherein the polyurethane resin satisfies at least one of the following conditions (1) and (2).

[0016] Condition (1): The aforementioned chain extender (ii) further comprises (ii-3) triol.

[0017] Condition (2): The aforementioned (iii) polyisocyanate component further includes (iii-3) polyfunctional isocyanates with more than three functions.

[0018] [2] According to the polyurethane resin described above [1], wherein the amount of the aforementioned (i) polyol component, the aforementioned (i-2) polyether polyol is 30 to 70% by mass.

[0019] [3] According to the polyurethane resin described above [1] or [2], wherein the aforementioned (ii-3) triol is trimethylolpropane.

[0020] [4] The polyurethane resin according to any one of [1] to [3] above, wherein the amount of the triol (ii-3) above is 0.06 to 0.5 parts by mass relative to 100 parts by mass of the polyol component (i) above.

[0021] [5] The polyurethane resin according to any one of [1] to [4] above, wherein the amount of the aforementioned (iii-3) polyfunctional isocyanate is 0.1 to 0.65 mol relative to the aforementioned (iii-1) aromatic diisocyanate.

[0022] [6] The polyurethane resin according to any one of [1] to [5] above, wherein at least one of the aforementioned (i) polyol component, the aforementioned (ii) chain extender and the aforementioned (iii) polyisocyanate component is a plant-derived compound.

[0023] [7] The polyurethane resin according to any one of [1] to [6] above is used as a constituent material of the moisture-permeable film.

[0024] In addition, according to the present invention, a moisture-permeable film as shown below is provided.

[0025] [8] A moisture-permeable film formed from the polyurethane resin described above [7].

[0026] Furthermore, according to the present invention, a breathable and waterproof fabric as shown below is provided.

[0027] [9] A breathable and waterproof fabric having: a base fabric and a skin layer disposed on the surface of the base fabric, wherein the skin layer is the breathable film described in [8].

[0028]

[10] The breathable and waterproof fabric described in [9] above also has an adhesive layer disposed between the base fabric and the skin layer.

[0029]

[11] The breathable and waterproof fabric described in [9] or

[10] above further has a porous layer disposed between the base fabric and the skin layer.

[0030] The effects of the invention

[0031] According to the present invention, a polyurethane resin capable of producing a breathable film with excellent moisture permeability, as well as excellent washability, alcohol resistance, recoating suitability, heat resistance, light resistance and flexibility can be provided.

[0032] In addition, according to the present invention, a moisture-permeable film obtained by using the polyurethane resin, which has excellent moisture permeability, as well as excellent washability, alcohol resistance, suitability for repeated coating, heat resistance, light resistance and softness, and a moisture-permeable waterproof fabric having the moisture-permeable film can be provided. Attached Figure Description

[0033] Figure 1 This is a schematic cross-sectional view illustrating one embodiment of the breathable and waterproof fabric of the present invention.

[0034] Figure 2 This is a cross-sectional view schematically illustrating other embodiments of the breathable and waterproof fabric of the present invention.

[0035] Figure 3 This is a schematic diagram illustrating the morphology of the specimen used in the evaluation of the embodiments.

[0036] Figure 4 This is a schematic diagram illustrating the form of the Geer oven used in the evaluation of the embodiment. Detailed Implementation

[0037] <Polyurethane Resin>

[0038] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments. One embodiment of the polyurethane resin of the present invention is a suitable polyurethane resin, such as a material for manufacturing a breathable film, wherein the polyurethane resin is a reaction product of (i) a polyol component, (ii) a chain extender, and (iii) a polyisocyanate component. Hereinafter, details of the polyurethane resin of the present invention will be described.

[0039] (i) Polyol components)

[0040] (i) The polyol component includes (i-1) polyethylene glycol and (i-2) polyether polyol other than (i-1) polyethylene glycol. It should be noted that (i) the polyol component preferably consists substantially only of (i-1) polyethylene glycol and (i-2) polyether polyol.

[0041] [(i-1)polyethylene glycol]

[0042] (i-1) Polyethylene glycol is a hydrophilic polyol that contributes to the moisture permeability of the formed film. (i-1) The number average molecular weight (Mn) of polyethylene glycol is preferably 600 to 10,000, more preferably 1,000 to 7,000.

[0043] [(i-2) polyether polyol]

[0044] (i-2) The polyether polyol is a component that improves the mechanical properties of the formed film. (i-2) The number average molecular weight (Mn) of the polyether polyol is preferably 650 to 3000, and more preferably 1000 to 2500.

[0045] Examples of (i-2) polyether polyols include polypropylene glycol, polyethylene glycol-polytetramethylene glycol (block or random), polytrimethylene ether glycol, polytetramethylene ether glycol, and polyhexamethylene ether glycol. Among these, polytrimethylene ether glycol and polytetramethylene ether glycol are preferred from the viewpoint of flexibility, etc.

[0046] (i-2) Polyether polyols can be obtained, for example, by polymerizing or copolymerizing any of epoxides (propylene oxide, butane oxide, etc.) and heterocyclic ethers (tetrahydrofuran, 2-methyltetrahydrofuran, etc.). Alternatively, (i-2) polyether polyols can also be obtained by the dehydration condensation reaction of diols such as 1,3-propanediol.

[0047] From the viewpoint of producing environmentally friendly resins and films, (i-2) polyether polyols are preferably plant-derived compounds. Examples of (i-2) polyether polyols that are plant-derived compounds include polyether polyols made from plant-derived diols, tetrahydrofurans, etc.

[0048] In the polyol component (total of (i-1) polyethylene glycol and (i-2) polyether polyol), the amount of (i-2) polyether polyol (hydrophobic polyol) is preferably 30 to 70% by mass, more preferably 35 to 60% by mass. By ensuring that the amount of (i-2) polyether polyol in the (i) polyol component is within the above range, a polyurethane resin capable of producing a breathable film with a superior balance between moisture permeability and softness can be manufactured.

[0049] (ii) Chain extenders)

[0050] (ii) The chain extender comprises two or more (ii-1) linear alkanediols having 2 to 4 carbon atoms, or (ii-2) linear, branched, or cyclic alkanediols other than (ii-1) linear alkanediols having 2 to 4 carbon atoms. That is, by combining two or more alkanediols with different numbers of carbon atoms in the alkylene group and using them as (ii) chain extenders, a polyurethane resin with improved permeability, such as improved recoating suitability, can be produced compared to using only one alkanediol as a chain extender. The reason for this effect is not entirely clear, but it can be speculated that by combining and using two or more alkanediols with different numbers of carbon atoms in the alkylene group, a moderate degree of "flexibility" is generated in the molecular chain of the polyurethane resin, resulting in a slight decrease in crystallinity.

[0051] (ii) The amount of chain extender, based on the total of (i) the polyol component and (ii) the chain extender, is preferably 0.2 to 40% by mass, more preferably 0.5 to 20% by mass, and particularly preferably 12 to 16% by mass. It should be noted that (ii) the chain extender preferably does not substantially contain amine compounds. If amine compounds are used as chain extenders, there is a tendency for the heat resistance of the resulting moisture-permeable film to decrease.

[0052] [(ii-1) Straight-chain alkanediols with 2 to 4 carbon atoms]

[0053] Examples of straight-chain alkyldiols with 2 to 4 carbon atoms in (ii-1) include ethylene glycol, 1,3-propanediol, and 1,4-butanediol. From the viewpoint of producing environmentally friendly resins and films, straight-chain alkyldiols with 2 to 4 carbon atoms in (ii-1) can be plant-derived compounds. Examples of plant-derived straight-chain alkyldiols with 2 to 4 carbon atoms in (ii-1) include plant-derived ethylene glycol, 1,3-propanediol, and 1,4-butanediol. Furthermore, plant-derived straight-chain alkyldiols and petroleum-derived straight-chain alkyldiols can be combined.

[0054] [(ii-2) Straight-chain, branched-chain, or cyclic-chain alkanediols]

[0055] As a straight-chain alkanediol, a straight-chain alkanediol with 5 or more carbon atoms can be used. Examples of straight-chain alkanediols with 5 or more carbon atoms include 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol.

[0056] As branched alkyl glycols, branched alkyl glycols with 3 or more carbon atoms can be used. Examples of branched alkyl glycols with 3 or more carbon atoms include 1,3-butanediol, 3-methyl-1,5-pentanediol (MPD), neopentanediol (NPD), 2-methylpropanediol, 2,2-dimethylpropanediol, 2-propyl-1,4-butanediol, 2-isopropyl-1,4-butanediol, 2-cyclopropyl-1,4-butanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 2-butyl-1,4-butanediol, 2-isobutyl-1,4-butanediol, and 2-methyl-1,3-pentanediol. Diol, 2,2,4-trimethyl-1,3-pentanediol, 2-propyl-1,5-pentanediol, 2-isopropyl-1,5-pentanediol, 2-cyclopropyl-1,5-pentanediol, 2-butyl-1,5-pentanediol, 2-propyl-1,6-hexanediol, 2-isopropyl-1,6-hexanediol, 2-cyclopropyl-1,6-hexanediol, 2-butyl-1,6-hexanediol, 2-propyl-1,7-heptanediol, 2-isopropyl-1,7-heptanediol, 2-cyclopropyl-1,7-heptanediol, 2-butyl-1 7-Heptanediol, 2-Methyl-1,8-Octandiol, 2-Propyl-1,8-Octandiol, 2-Isopropyl-1,8-Octandiol, 2-Cyclopropyl-1,8-Octandiol, 2-Butyl-1,8-Octandiol, 2-Propyl-1,9-Nonadiol, 2-Isopropyl-1,9-Nonadiol, 2-Cyclopropyl-1,9-Nonadiol, 2-Butyl-1,9-Nonadiol, 2-Cyclobutyl-1,9-Nonadiol, 2-Propyl-1,10-Decandiol, 2-Isopropyl-1,10-Decandiol, 2-Cyclopropyl Examples of alcohols include 2-butyl-1,10-decanediol, 2-propyl-1,11-undecanediol, 2-isopropyl-1,11-undecanediol, 2-cyclopropyl-1,11-undecanediol, 2-butyl-1,11-undecanediol, 2-dodecyl-1,11-undecanediol, 2-propyl-1,12-dodecanediol, 2-isopropyl-1,12-dodecanediol, 2-cyclopropyl-1,12-dodecanediol, and 2-butyl-1,12-dodecanediol.

[0057] In addition, examples of cyclic alkyl diols include 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanediol, and 2,2'-bis(4-hydroxycyclohexyl)propane.

[0058] (iii) Polyisocyanate components)

[0059] (iii) Polyisocyanate components are compounds having two or more isocyanate groups (NCO groups) in one molecule, and include (iii-1) aromatic diisocyanates and (iii-2) aliphatic diisocyanates.

[0060] [(iii-1) Aromatic diisocyanates]

[0061] Examples of (iii-1) aromatic diisocyanates include 4,4'-diphenylmethane diisocyanate (MDI), 2,2'-MDI, 2,4'-MDI, 2,4-toluene diisocyanate (TDI), 2,6-TDI, m-phenylenedimethyl diisocyanate (XDI), 1,4-phenylene diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3-phenylene diisocyanate, 4-butoxy-1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 1,5-naphthalene diisocyanate, and benzidine diisocyanate. Among these, MDI is preferred.

[0062] [(iii-2) Aliphatic diisocyanates]

[0063] Examples of aliphatic diisocyanates (iii-2) include 1,4-tetramethylene diisocyanate, 1,5-pentanediisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), and 1,10-dedecimethylene diisocyanate; and alicyclic diisocyanates such as 4,4'-methylenebis(cyclohexylisocyanate), isophorone diisocyanate (IPDI), 1,3-bis(isocyanate-methyl)cyclohexane (hydrogenated XDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), and 1-methylcyclohexane-2,4-diisocyanate (hydrogenated TDI). Among these, HDI and plant-derived PDI are preferred.

[0064] The preferred mass ratio of (iii-1) aromatic diisocyanate to (iii-2) aliphatic diisocyanate is (iii-1):(iii-2) = 30:70 to 85:15, more preferably 60:40 to 80:20. If the amount of (iii-1) aromatic diisocyanate is excessive, the resulting moisture-permeable film tends to harden. Conversely, if the amount of (iii-2) aliphatic diisocyanate is excessive, the resulting moisture-permeable film tends to become soft. Furthermore, based on the total amount of the (iii) polyisocyanate component, the amount of (iii-2) aliphatic diisocyanate is preferably 10 to 85 mol%, more preferably 20 to 60 mol%, and particularly preferably 30 to 40 mol%.

[0065] From the viewpoint of producing environmentally friendly resins and films, at least one of (i) the polyol component, (ii) the chain extender and (iii) the polyisocyanate component is preferably a plant-derived compound.

[0066] (Conditions (1) and (2))

[0067] The polyurethane resin of this embodiment satisfies at least one of the following conditions (1) and (2).

[0068] Condition (1): (ii) The chain extender further comprises (ii-3) triol.

[0069] Condition (2): (iii) The polyisocyanate component further includes (iii-3) polyfunctional isocyanates with more than three functions.

[0070] To improve the alcohol resistance, heat resistance, and other properties of the breathable film, simply increasing the amount of hard segments in the polyurethane resin used as a raw material easily compromises the film's softness (feel, etc.). In contrast, the polyurethane resin of this embodiment, obtained by reacting at least one of the above conditions (1) and (2), namely, compounds with three or more functionalities such as (ii-3) triol and (iii-3) polyfunctional isocyanate, becomes a branched polymer (thermoplastic resin) with an internal cross-linking structure. By forming such an internal cross-linking structure, the polyurethane resin of this embodiment can produce a breathable film that maintains softness while improving properties such as washability, alcohol resistance, and heat resistance. Conversely, when compounds with three or more functionalities such as (ii-3) triol and (iii-3) polyfunctional isocyanate are reacted after the polyurethane resin is synthesized, a thermosetting resin with a so-called network structure is easily formed, resulting in a time lag in softness (feel).

[0071] [(ii-3)triol]

[0072] (ii-3) Triols are trifunctional polyols having three hydroxyl groups (OH groups) in one molecule. The molecular weight (formula weight) of the (ii-3) triol is preferably 500 or less, more preferably 300 or less. Examples of (ii-3) triols include glycerol, trimethylolethane, trimethylolpropane, glycerol, pentanetriol, hexanetriol, heptatriol, and octanetriol. Among these, glycerol and trimethylolpropane are preferred, and trimethylolpropane is more preferred.

[0073] When the polyurethane resin of this embodiment satisfies condition (1), the amount of (ii-3) triol relative to 100 parts by mass of (i) polyol is preferably 0.06 to 0.5 parts by mass, more preferably 0.1 to 0.45 parts by mass. By setting the amount of (ii-3) triol relative to 100 parts by mass of (i) polyol within the above range, a polyurethane resin capable of producing a breathable film with further improved washability, alcohol resistance, and heat resistance can be manufactured.

[0074] [(iii-3) Polyfunctional isocyanates]

[0075] (iii-3) Polyfunctional isocyanates are trifunctional or higher polyfunctional isocyanates having three or more isocyanate groups (NCO groups) in one molecule. Examples of (iii-3) polyfunctional isocyanates include diphenylmethane diisocyanate systems, toluene diisocyanate systems, hexamethylene diisocyanate systems, pentamethylene diisocyanate systems, and isophorone diisocyanate systems; their trimethylolpropane adducts, biuret forms, and ureate forms; polymeric MDI; terminal isocyanate prepolymers; etc. Block polyisocyanates of these can also be used. Among these, adducts, biuret forms, and ureate forms of aliphatic diisocyanates such as hexamethylene diisocyanate and pentamethylene diisocyanate are preferred.

[0076] When the polyurethane resin of this embodiment satisfies condition (2), the amount of (iii-3) polyfunctional isocyanate relative to (iii-1) aromatic diisocyanate is preferably 0.1 to 0.65 mol%, more preferably 0.2 to 0.5 mol%. By setting the amount of (iii-3) polyfunctional isocyanate relative to (iii-1) aromatic diisocyanate within the above range, a polyurethane resin capable of producing a breathable film with further improved washability, alcohol resistance, and heat resistance can be manufactured.

[0077] (Manufacturing method of polyurethane resin)

[0078] Polyurethane resins can be manufactured, for example, by reacting (i) a polyol component, (ii) a chain extender, and (iii) a polyisocyanate component in a one-step or multi-step process at a preferably 60–150°C, more preferably 60–110°C. Catalysts can also be used in combination as needed during the reaction. Examples of catalysts include metal salts and organometallic derivatives such as dibutyltin dilaurate, dioctyltin dilaurate, stannous octoate, lead octoate, and tetrabutyl titanate; organic amines such as triethylamine; and diazabicycloundecene catalysts; etc.

[0079] (i) the polyol component, (ii) the chain extender, and (iii) the polyisocyanate component can be reacted in the presence of solvents such as organic solvents. By reacting in the presence of a solvent, the polyurethane resin can be obtained in the form of a solution dissolved in the solvent or a dispersion dispersed in the solvent. Examples of organic solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, N-ethylpyrrolidone, β-alkoxypropionamide, dipropylene glycol dimethyl ether, and ethyl acetate.

[0080] In the solution or dispersion of polyurethane resin, appropriate amounts of thermoplastic resin, tackifying resin, catalyst, pigment, antioxidant, ultraviolet absorber, surfactant, flame retardant, filler and foaming agent and other additives may also be mixed as needed.

[0081] <Moisture permeable film>

[0082] One embodiment of the breathable film of the present invention is a breathable and waterproof film formed from the aforementioned polyurethane resin. That is, the breathable film of this embodiment is formed from the aforementioned polyurethane resin, and therefore exhibits excellent breathability, as well as excellent washability, alcohol resistance, suitability for repeated coating, heat resistance, light resistance, and softness. Therefore, the breathable film of this embodiment is suitable as a material for constructing breathable and waterproof fabrics.

[0083] Moisture-permeable films can be manufactured, for example, by coating a solution or dispersion of polyurethane resin onto a substrate such as release paper and then drying to remove the solvent. Commonly known coating methods include comma coating, blade coating, roller coating, gravure coating, and spray coating.

[0084] The thickness of the moisture-permeable membrane can be appropriately set within the range that achieves both moisture permeability and water resistance; for example, it can be set within the range of 10 to 15 μm. The thickness of the moisture-permeable membrane can be appropriately set by changing the thickness of the coating film formed by coating a polyurethane resin solution onto a substrate.

[0085] The 100% modulus of the moisture-permeable film at 25°C is typically 3.0–5.0 MPa, preferably 3.5–4.5 MPa. Furthermore, the 20% modulus of the moisture-permeable film at 25°C is typically 1.5–4.0 MPa, preferably 1.8–3.7 MPa. The moisture-permeable film of this embodiment, with its 100% and 20% modulus values ​​falling within the aforementioned ranges, maintains a better balance between properties such as washability and softness (hand feel).

[0086] <Breathable waterproof fabric>

[0087] Figure 1 This is a schematic cross-sectional view illustrating one embodiment of the breathable and waterproof fabric of the present invention. Figure 1As shown, the breathable and waterproof fabric 100 of this embodiment has a base fabric 2 and a skin layer 4 disposed on the surface of the base fabric 2. Furthermore, the skin layer 4 is the aforementioned breathable film formed from a specific polyurethane resin. The breathable and waterproof fabric 100 of this embodiment uses a film with excellent washability, alcohol resistance, suitability for repeated coating, heat resistance, lightfastness, and softness, as its skin layer 4. Therefore, the breathable and waterproof fabric 100 of this embodiment has excellent breathability and waterproofness, and also excellent washability, alcohol resistance, heat resistance, lightfastness, and softness.

[0088] Figure 2 This is a cross-sectional view schematically illustrating other embodiments of the breathable and waterproof fabric of the present invention. Figure 2 The breathable and waterproof fabric 200 of the illustrated embodiment also has a porous layer 6 and an adhesive layer 8 disposed between the base fabric 2 and the outer skin layer 4. That is, the outer skin layer 4 can be fixed to the base fabric 2 by means of the adhesive layer 8, or it can be fixed to the base fabric 2 by means of the porous layer 6 and the adhesive layer 8.

[0089] The adhesive layer 8 can be formed, for example, by a two-component curing urethane adhesive used in the manufacture of existing fabrics, such as breathable and waterproof fabrics. Furthermore, the porous layer 6 is the same layer as the porous layer constituting existing breathable and waterproof fabrics, and can be formed, for example, by urethane resin, cellulose acetate, epoxy resin, etc.

[0090] Examples of base fabric 2 include: woven fabrics containing twill weave, plain weave, etc.; napped fabric obtained by mechanically napping the cotton greige of the woven fabric; rayon fabric; nylon fabric; polyester fabric; Kevlar fabric; nonwoven fabrics (polyester, nylon, various latexes); various films, sheets, etc.

[0091] Breathable and waterproof fabrics can be manufactured, for example, by bonding a breathable film prepared using the aforementioned method to a base fabric using an adhesive. Additionally, in order to manufacture such... Figure 1 The breathable and waterproof fabric 100, which is formed by directly setting a breathable film as the skin layer 4 on the base fabric 2, can be manufactured by coating a polyurethane resin solution or dispersion onto the base fabric 2 in a manner that achieves the desired thickness and then drying it.

[0092] Example

[0093] The present invention will now be specifically described based on embodiments, but the present invention is not limited to these embodiments. It should be noted that, unless otherwise stated, "parts" and "%" in the embodiments and comparative examples are quality standards.

[0094] <Manufacturing of Polyurethane Resin>

[0095] (Example 1)

[0096] In a glass reaction vessel equipped with a stirrer and thermometer, 17.9 parts of polyethylene glycol 2000 (number average molecular weight: 2000), 41.7 parts of polytetramethylene glycol 2000 (number average molecular weight: 2000), 3.6 parts of ethylene glycol, 5.2 parts of 1,4-butanediol, and 0.2 parts of trimethylolpropane were added as (i) polyol components and (ii) chain extenders. Then, 163.9 parts of dimethylformamide (DMF) and 70.2 parts of methyl ethyl ketone (MEK) were added, and the mixture was stirred at 50°C for 30 minutes. Next, 10.0 parts of hexamethylene diisocyanate and 21.9 parts of diphenylmethane diisocyanate were added as (iii) polyisocyanate components, and the reaction was carried out at 80°C for 3 hours to obtain a solution containing polyurethane resin. The resulting solution had a solids content of 30.0% and a viscosity of 1000 dPa·s at 25°C.

[0097] (Examples 2-30, Comparative Examples 1-9)

[0098] The mixtures (unit: parts) shown in the top row of Tables 1-1 to 1-4 were prepared in the same manner as in Example 1 described above, except that a solution containing polyurethane resin was obtained. The solid content of the resulting solutions was 30.0%. Details of the materials used are shown in Tables 2 to 4.

[0099] Table 1-1

[0100]

[0101] *1: The amount (%) of chain extender (ii) is based on the total of (i) polyol components and (ii) chain extenders.

[0102] Table 1-2

[0103]

[0104] *1: The amount (%) of chain extender (ii) is based on the total of (i) polyol components and (ii) chain extenders.

[0105] Table 1-3

[0106]

[0107] *1: The amount (%) of chain extender (ii) is based on the total of (i) polyol components and (ii) chain extenders.

[0108] Table 1-4

[0109]

[0110] *1: The amount (%) of chain extender (ii) is based on the total of (i) polyol components and (ii) chain extenders.

[0111] Table 2

[0112]

[0113] Table 3

[0114]

[0115] Table 4

[0116]

[0117] <Manufacturing of breathable and waterproof fabrics>

[0118] (Standard fabric)

[0119] (1) Manufacturing of moisture-permeable films

[0120] 100 parts of solvent-based urethane resin (trade name "HI-MUREN Y-286FM", manufactured by Daihatsu Seika Co., Ltd.), 10 parts of DMF, and 5 parts of MEK were mixed to obtain a formulation for the skin layer. Using a gap coater, the obtained formulation for the skin layer was uniformly coated onto release paper at a coating thickness of 50 μm·wet. After drying at 80°C for 2 minutes, it was further dried at 120°C for 3 minutes to obtain a moisture-permeable film (skin layer) with a thickness of 10–15 μm.

[0121] (2) Bonding of the skin layer to the base fabric

[0122] A mixture of 100 parts solvent-based urethane resin (trade name "Y-173", manufactured by Dai Nippon Seika Kogyo Co., Ltd.), 10 parts solvent-based polyisocyanate crosslinking agent A (trade name "RESAMINE NE-CROSS-LINKER", manufactured by Dai Nippon Seika Kogyo Co., Ltd.), 1 part solvent-based polyisocyanate crosslinking agent B (trade name "RESAMINE UD-CROSS-LINKER", manufactured by Dai Nippon Seika Kogyo Co., Ltd.), 20 parts DMF, and 40 parts MEK was prepared to obtain a formulation for the adhesive layer. The obtained formulation for the adhesive layer was coated onto a skin layer (moisture-permeable film) and dried to form an adhesive layer. A base fabric (nylon tafeta) was then laminated onto the formed adhesive layer and heat-pressed at a lamination temperature of 40°C. Finally, it was cured at 50°C for 48 hours to obtain a standard breathable and waterproof fabric.

[0123] (Evaluation cloth)

[0124] Instead of the mixing solution used for the skin layer, the prepared solution containing polyurethane resin was used, and the evaluation fabric was obtained in the same manner as the standard fabric mentioned above.

[0125] <Evaluation>

[0126] In the evaluation criteria shown below, “◎”, “○”, and “△” are set as qualified, and “×” is set as unqualified. The evaluation results are shown in Table 5.

[0127] (Feel)

[0128] The feel of the standard fabric and the evaluation fabric were compared by hand, and the feel (softness) was evaluated according to the evaluation criteria shown below.

[0129] ◎: The fabric used for evaluation is softer than the standard fabric.

[0130] ○: The fabric used for evaluation is of the same degree of softness as the standard fabric.

[0131] ×: The fabric used for evaluation is stiffer than the standard fabric.

[0132] (Suitability for repeated coating)

[0133] When bonding the skin layer to the base fabric, the condition of the skin layer was visually confirmed immediately after the adhesive layer mixture was applied and after drying. The suitability for recoating was evaluated according to the evaluation criteria shown below. It should be noted that, for Comparative Example 4, the skin layer (film) dissolved immediately after the adhesive layer mixture was applied, so the suitability for recoating could not be evaluated.

[0134] ○: No swelling.

[0135] △: Slight swelling exists.

[0136] ×: The entire surface has swollen or the epidermal layer has dissolved.

[0137] (Thin Film Properties)

[0138] The prepared polyurethane resin solution was coated onto release paper and dried at 80°C for 2 minutes and 120°C for 3 minutes, respectively. After drying, it was peeled off from the release paper to obtain a translucent film with a thickness of 50 μm, a width of 1.5 cm, and a length of 6 cm. Using a universal tensile testing machine (trade name "AGS-J", manufactured by Shimadzu Corporation), the translucent film was stretched at a speed of 200 mm / min under conditions of 25°C and RH below 30%, and the 20% modulus (MPa) and 100% modulus (MPa) were measured.

[0139] (Heat softening point)

[0140] The semi-transparent film (50 μm thick, 1.5 cm wide, and 6 cm long) prepared in the above "Film Properties" section was used as the test piece. Figure 3 As shown, clamps 12 are installed above and below the film 10, and the clamps 12 are further secured with glass strips. A weight 14 is installed on one side of the clamp 12 to apply 450 g / cm² during suspension. 2 Under the load, sample 16 was prepared. It should be noted that the central portion (2 cm) of film 10 was not covered by the glass ribbon. Next, as... Figure 4 As shown, the clamp 12 of the sample 16 without the weight 14 was mounted on the turntable 22 of the GIL oven 20. Then, while rotating the turntable 22 at 5 rpm, the temperature inside the GIL oven 20 was increased from room temperature at a rate of 3 °C / min, and the temperature at which the film 10 was cut (thermal softening point (°C)) was measured.

[0141] (Alcohol resistance)

[0142] The prepared polyurethane resin solution was coated onto release paper and dried at 80°C for 2 minutes and 120°C for 3 minutes, respectively. After drying, it was peeled off from the release paper to obtain a film with a thickness of 50 μm, a width of 5 cm, and a length of 5 cm. The obtained film was immersed in ethanol for 10 minutes and then removed. The linear swelling ratio of the removed film was calculated (={(width of the film after immersion) / (width of the film before immersion)}×100(%)), and the solvent resistance was evaluated according to the evaluation criteria shown below.

[0143] ○: The linear swelling ratio of one side of the film is less than 200%.

[0144] △: The linear swelling rate of one side of the film is over 200%.

[0145] ×: Thin film dissolution.

[0146] (Lightfastness)

[0147] The prepared polyurethane resin solution was coated onto release paper and dried at 80°C for 2 minutes and 120°C for 3 minutes, respectively. After drying, it was peeled off from the release paper to obtain a film with a thickness of 50 μm, a width of 8 cm, and a length of 15 cm. A lightfastness test was conducted on the obtained film using a xenon lamp weathering tester at 70±3°C and an irradiation energy of 20 MJ. The tensile strength of the film before and after the lightfastness test was measured using a tensile testing apparatus at 25°C and a tensile speed of 200 mm / min. The lightfastness was evaluated according to the evaluation criteria shown below.

[0148] ○: The retention rate of fracture strength is more than 50%.

[0149] △: The retention rate of fracture strength is above 25% but below 50%.

[0150] ×: The retention rate of fracture strength is less than 25% or the film dissolves.

[0151] (Moisture permeability)

[0152] The moisture permeability (g / m³) of the evaluation fabric was determined according to the "Calcium acetate method (B-1 method)" in JIS L 1099:2012. 2 • 24h). It should be noted that a moisture permeability of 40000g / m² can be used. 2 • Conditions lasting more than 24 hours are rated as "○", and 20000g / m 2 • More than 24 hours and less than 40000 g / m 2 • The 24-hour condition is evaluated as "△", which means that the concentration of the substance below 20000 g / m³ is acceptable. 2 • The 24-hour evaluation was “×”. It should be noted that the film formed from the solution of the polyurethane resin of Comparative Example 5, which was manufactured without the use of (ii) chain extender, was extremely soft and cracked during the test, so the moisture permeability could not be measured.

[0153] (Washability)

[0154] For the evaluation fabric, washing according to the "C-type standard washing machine (Pulsator type)" of JIS L 1930:2014 and drying according to the "Drying C method (flat drying)" were alternately repeated a total of 20 times. Then, the water pressure resistance of the evaluation fabric before and after washing / drying was measured according to the "B method (high water pressure method)" of JIS L1092:2009, and the washability was evaluated according to the evaluation criteria shown below.

[0155] ◎: The water pressure resistance retention rate is over 80%.

[0156] ○: The water pressure resistance retention rate is above 70% and below 80%.

[0157] ×: The water pressure resistance retention rate is less than 70%.

[0158] Table 5

[0159]

[0160] Industrial availability

[0161] The polyurethane resin of the present invention is useful as a material for forming a breathable film constituting a breathable and waterproof fabric, etc.

[0162] Explanation of reference numerals in the attached figures

[0163] 2: Base Cloth

[0164] 4: Epidermis

[0165] 6: Porous layer

[0166] 8: Adhesive layer

[0167] 10: Film

[0168] 12: Fixture

[0169] 14: Weights

[0170] 16: Sample

[0171] 20: Gill-type drying oven

[0172] 22: Spinning Wheel

[0173] 100, 200: breathable waterproof fabric.

Claims

1. A polyurethane resin, comprising (i) a polyol component, (ii) a chain extender and (iii) a polyisocyanate component, The (i) polyol component includes (i-1) polyethylene glycol and (i-2) polyether polyols other than the (i-1) polyethylene glycol. The chain extender comprises two or more (ii-1) straight-chain alkanediols having 2 to 4 carbon atoms, or comprises (ii-2) straight-chain, branched, or cyclic alkanediols other than the (ii-1) straight-chain alkanediols having 2 to 4 carbon atoms and the (ii-1) straight-chain alkanediols having 2 to 4 carbon atoms. The (iii) polyisocyanate component comprises (iii-1) aromatic diisocyanate and (iii-2) aliphatic diisocyanate. The (iii-1) aromatic diisocyanate is at least one selected from the group consisting of 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and 2,4'-diphenylmethane diisocyanate. The polyurethane resin satisfies at least one of the following conditions (1) and (2): Condition (1): The chain extender (ii) further comprises (ii-3) triol, wherein the amount of (ii-3) triol is 0.06 to 0.5 parts by mass relative to 100 parts by mass of the polyol component (i). Condition (2): The (iii) polyisocyanate component further comprises (iii-3) polyfunctional isocyanates with more than three functions, and the amount of (iii-3) polyfunctional isocyanates is 0.1 to 0.65 mol relative to the (iii-1) aromatic diisocyanate.

2. The polyurethane resin according to claim 1, wherein, In the polyol component (i), the amount of the polyether polyol (i-2) is 30-70% by mass.

3. The polyurethane resin according to claim 1, wherein, The (ii-3) triol is trimethylolpropane.

4. The polyurethane resin according to claim 1, wherein, At least one of the (i) polyol component, the (ii) chain extender, and the (iii) polyisocyanate component is a plant-derived compound.

5. The polyurethane resin according to any one of claims 1 to 4, which is used as a constituent material of a moisture-permeable film.

6. A moisture-permeable film formed from the polyurethane resin of claim 5.

7. A breathable and waterproof fabric, comprising: a base fabric and a skin layer disposed on the surface of the base fabric. The outer skin layer is the moisture-permeable film as described in claim 6.

8. The breathable and waterproof fabric according to claim 7, further comprising an adhesive layer disposed between the base fabric and the outer skin layer.

9. The breathable and waterproof fabric according to claim 7 or 8, further comprising a porous layer disposed between the base fabric and the skin layer.

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