Water stop film

Abstract

A water stop film having a water-permeable substrate, a water-absorbent polymer-containing layer, and an adhesive layer in this order, the water-absorbent polymer-containing layer having a cross-sectional shape in which at least a portion protrudes in a direction away from the water-permeable substrate.

Description

Technical Field

[0001] The invention relates to a water-stopping membrane. Background Art

[0002] In order to mitigate the damage caused by water intrusion or leakage, various water stopping technologies are being studied.

[0003] For example, Japanese Utility Model No. 4-8610 describes a waterproofing device for concrete joints, which is characterized in that a gap in a concrete joint of a concrete structure is formed by a long synthetic resin tape and a support body polymerized therewith, and a waterproofing device is provided on the surface of the synthetic resin tape to provide an adhesive layer bonded to the surface of the concrete joint for waterproofing, wherein the support body is formed by a long synthetic resin foam material having a cross-section of a trapezoidal, triangular or other base and two oblique sides, and a non-woven fabric waterproofing tape wider than the base is polymerized on the surface of the base. Summary of the invention

[0004] Technical issues to be solved by the invention

[0005] As a water-stopping technology, a method of covering the water inlet or water outlet with a water-stopping film is being studied. For example, most of the water damage to buildings is caused by water penetrating into the building through the gaps between objects such as windows and doors. In order to prevent or reduce the water damage as described above, it is considered effective to cover the gaps between objects such as windows and doors with a water-stopping film. In the construction using the water-stopping film, durability is required.

[0006] The present invention has been made in view of such circumstances, and an object of one embodiment of the present invention is to provide a waterproof film having excellent durability.

[0007] Means for solving technical problems

[0008] The present invention includes the following aspects.

[0009] <1>

[0010] A waterproof membrane comprises a water-permeable substrate, a water-absorbing polymer layer and an adhesive layer in this order, wherein the water-absorbing polymer layer has a cross-sectional shape in which at least a portion of the cross-sectional shape protrudes in a direction away from the water-permeable substrate.

[0011] <2>

[0012] The waterproof film according to <1>, wherein the water-absorbing polymer-containing layer comprises, in order:

[0013] A flat first water-absorbent polymer-containing layer on the surface of the water-permeable substrate; and

[0014] The second water-absorbent polymer-containing layer has a convex cross-sectional shape on the surface of the first water-absorbent polymer-containing layer.

[0015] <3>

[0016] The waterproof film according to <2>, wherein the swelling rate of the second water-absorbing polymer-containing layer is greater than the swelling rate of the first water-absorbing polymer-containing layer.

[0017] <4>

[0018] The waterproof film according to <3>, wherein the expansion rate of the second water-absorbing polymer-containing layer is 1.5 to 5 times the expansion rate of the first water-absorbing polymer-containing layer.

[0019] <5>

[0020] The waterproof film according to any one of <1> to <4>, wherein the cross-sectional shape of the water-absorbing polymer-containing layer is a tapered shape whose width decreases in a direction away from the water-permeable substrate.

[0021] <6>

[0022] The waterproof membrane according to any one of <1> to <5>, wherein the water-permeable base material has an elongation of 100% to 300%.

[0023] <7>

[0024] The waterproof membrane according to any one of <1> to <6>, wherein the basis weight of the water-permeable substrate is 100 g / m 2 ~200g / m 2 .

[0025] <8>

[0026] The waterproof membrane according to any one of <1> to <7>, wherein the water-permeable substrate is a nonwoven fabric, cloth or paper.

[0027] Effects of the Invention

[0028] According to the present invention, a waterproof film having excellent durability is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic perspective view showing the structure of a waterproof film according to one embodiment of the present invention.

[0030] Figure 2 is along Figure 1 Sectional view taken along line AA.

[0031] Figure 3A It is a schematic cross-sectional view showing the structure of Modification 1 of the waterproof membrane.

[0032] Figure 3B It is a schematic cross-sectional view showing the structure of a second modification of the waterproof membrane.

[0033] Figure 3C It is a schematic cross-sectional view showing the structure of Modification 3 of the waterproof membrane.

[0034] Figure 3D It is a schematic cross-sectional view showing the structure of Modification 4 of the waterproof membrane. DETAILED DESCRIPTION

[0035] Hereinafter, the waterproof film of the present invention will be described in detail.

[0036] In the present invention, a numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0037] In the present invention, when there are multiple substances corresponding to each component in the composition, the amount of each component in the composition means the total amount of the multiple substances present in the composition unless otherwise specified.

[0038] In the numerical ranges described stepwise in the present invention, the upper limit or lower limit described in a certain numerical range may be replaced by the upper limit or lower limit of another numerical range described stepwise, or may be replaced by the value shown in the Examples.

[0039] In the present invention, the term "process" refers not only to an independent process but also to a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process can be achieved.

[0040] In the present invention, a combination of preferred embodiments is a more preferred embodiment.

[0041] The elements in the drawings shown in the present invention are not necessarily accurate scales, but are intended to clearly illustrate the principles of the present invention, and there are also emphasized areas. In addition, the elements represented by the same symbols in the drawings refer to the same elements.

[0042] [Waterstop film]

[0043] The waterproof film of the present invention comprises a water-permeable substrate, a water-absorbing polymer layer and an adhesive layer in this order, wherein the water-absorbing polymer layer has a cross-sectional shape in which at least a portion of the cross-sectional shape protrudes in a direction away from the water-permeable substrate. By using the waterproof film of the present invention to cover a gap in an object, water can be stopped when water penetrates into the gap.

[0044] In the film of the present invention, the water-absorbent polymer layer has a cross-sectional shape in which at least a portion of the cross-sectional shape protrudes in a direction away from the water-permeable substrate, so that the protruding portion can be inserted into the gap of the object. In addition, if water penetrates into the water-permeable substrate, the water flows into the water-absorbent polymer layer through the water-permeable substrate, and the water-absorbent polymer layer swells. By swelling the water-absorbent polymer layer, the water-stopping membrane can be arranged in a manner that fills the gap. Therefore, if the water-stopping membrane of the present invention is used, water can be stopped for a long time. That is, the water-stopping membrane of the present invention has excellent durability.

[0045] On the other hand, Japanese Utility Model Publication No. 4-8610 does not describe a water-absorbing polymer-containing layer, and it is considered that the durability is insufficient.

[0046] Below, refer to the attached Figure 1 One embodiment of the waterproof film of the present invention will be described.

[0047] Figure 1 It is a schematic perspective view showing the structure of a waterproof film according to one embodiment of the present invention. Figure 2 is along Figure 1 Sectional view taken along line AA.

[0048] like Figure 2 As shown, a waterproof membrane 100 according to an embodiment of the present invention includes a water-permeable substrate 10 , a water-absorbent polymer-containing layer 20 , and an adhesive layer 30 in this order.

[0049] The waterproof film 100 is used, for example, to prevent water damage to buildings. For example, when windows and doors are closed, the waterproof film is attached to cover the gap between the window and the window frame, the gap between the door and the door frame, and the gap between the doors. The waterproof film 100 can be attached from the water inflow side or the water outflow side.

[0050] (Water-permeable substrate)

[0051] The water-permeable substrate is not particularly limited as long as it is a substrate having water permeability.

[0052] In the present invention, "water permeability" refers to a property that liquid water can pass through. Specifically, the water permeable substrate preferably has pores through which water can pass.

[0053] In the waterproof film, the water-permeable substrate has the function of holding the water-absorbing polymer layer. When water enters the water-absorbing polymer layer through the water-permeable substrate, the water-absorbing polymer layer swells. The water-permeable substrate also has the function of efficiently bringing water into contact with the water-absorbing polymer layer.

[0054] From the viewpoint of water permeability, the water-permeable substrate is preferably a layer containing fibers, more preferably a layer containing cellulose fibers, rayon fibers, polyolefin fibers, or polyester fibers.

[0055] From the viewpoint of water permeability, the water-permeable substrate is preferably a nonwoven fabric, cloth or paper, and more preferably a nonwoven fabric.

[0056] The water-permeable substrate is preferably in an elongated shape, and the length and width are not particularly limited. The length refers to the length in the longitudinal direction of the water-permeable substrate, and the width refers to the length in a direction perpendicular to the longitudinal direction of the water-permeable substrate.

[0057] In the water-permeable substrate, it is preferred that water and the water-absorbing polymer layer be efficiently contacted to swell the water-absorbing polymer layer. If the water-absorbing polymer layer is swollen, a waterproof film is arranged to fill the gap into which water flows, thereby enabling water to be stopped in a shorter time.

[0058] From the viewpoint of efficiently bringing water into contact with the water-absorbent polymer layer, the basis weight of the water-permeable substrate is preferably 250 g / m 2 Below, more preferably 200g / m 2 Below, more preferably 150g / m 2 From the viewpoint of workability, the basis weight of the water-permeable substrate is preferably 60 g / m 2 More preferably 100 g / m 2 The basis weight of the water-permeable substrate is preferably 60 g / m 2 Above and 250g / m 2 The following range.

[0059] Basis weight refers to mass per unit area. In the present invention, basis weight is measured by the following method.

[0060] A test piece with a width of 50 mm and a length of 500 mm was obtained from the water-permeable substrate. The mass (g) of the test piece was measured. 2 The mass (g) is taken as the basis weight.

[0061] Furthermore, from the viewpoint of making the waterproof film more closely fit around the gap of the object, the elongation of the water-permeable substrate is preferably 100% to 300%, and more preferably 100% to 150%. In particular, when there is a step difference around the gap of the object, if the elongation of the water-permeable substrate is within the above range, the waterproof film can be arranged in a manner that follows the shape of the gap around the object, thereby improving durability.

[0062] In the present invention, the elongation is measured by the following method.

[0063] A load of 1.5 kg was applied to a water-permeable substrate having a width of 50 mm in the longitudinal direction. The elongation was calculated by the following formula from the length T0 of the water-permeable substrate before the load was applied and the length T1 of the water-permeable substrate after the load was applied.

[0064] Elongation (%) = {(T1-T0) / T0} × 100

[0065] The thickness of the water-permeable substrate is not particularly limited, and is, for example, 15 μm to 200 μm.

[0066] In the present invention, the thickness is represented by the arithmetic average of the thicknesses measured at five locations.

[0067] (Contains water-absorbent polymer layer)

[0068] The water-absorbent polymer-containing layer 20 is a layer containing a water-absorbent polymer provided on the water-permeable substrate 10. Figure 1 As shown, the water-absorbent polymer-containing layer 20 has a cross-sectional shape in which at least a portion thereof protrudes in a direction away from the water-permeable substrate.

[0069] The water-absorbent polymer layer 20 swells when absorbing water, and when the swollen water-absorbent polymer layer blocks the gap of the object, water is stopped. The water-absorbent polymer layer 20 has a cross-sectional shape in which at least a portion protrudes in a direction away from the water-permeable substrate, so that the water-stopping film can be inserted into the gap. The object and the water-stopping film have high adhesion and excellent durability.

[0070] The water-absorbent polymer-containing layer may be provided on the water-permeable substrate, and another layer may be provided between the water-permeable substrate and the water-absorbent polymer-containing layer. However, from the viewpoint of efficiently moving water from the water-permeable substrate to the water-absorbent polymer-containing layer, it is preferably provided on the surface of the water-permeable substrate.

[0071] The water-absorbent polymer layer may have a cross-sectional shape in which at least a portion of the cross-sectional shape protrudes in a direction away from the water-permeable substrate, and the specific shape is not particularly limited. Figure 2 As shown, a portion of the cross-sectional shape of the water-absorbent polymer-containing layer 20 is triangular.

[0072] Among them, from the viewpoint of workability, the cross-sectional shape of the water-absorbent polymer layer is preferably a tapered shape whose width decreases in the direction away from the water-permeable substrate. The width may decrease continuously or discontinuously. It may include a portion whose width does not change in the direction away from the water-permeable substrate. Figure 2 As shown, the water-absorbent polymer-containing layer 20 has a triangular cross-section whose width continuously decreases in a direction away from the water-permeable substrate.

[0073] And, if Figure 2As shown, the water-absorbent polymer-containing layer 20 has, in this order: a flat first water-absorbent polymer-containing layer 20A on the surface of the water-permeable substrate 10; and a second water-absorbent polymer-containing layer 20B having a convex cross-sectional shape on the surface of the first water-absorbent polymer-containing layer 20A.

[0074] “Flat” means having a flat surface with few irregularities on the surface. Specifically, the surface roughness Ra of the first water-absorbent polymer-containing layer is preferably 1 μm or less.

[0075] The "convex shape" refers to a shape protruding from a reference surface (here, the surface of the first water-absorbent polymer-containing layer). In the present invention, when the distance from the surface of the first water-absorbent polymer-containing layer to the surface of the farthest protruding portion of the second water-absorbent polymer-containing layer is 5 mm or more, the cross-sectional shape of the second water-absorbent polymer-containing layer is a convex shape.

[0076] The water-absorbent polymer-containing layer may be only the second water-absorbent polymer-containing layer having a convex cross-sectional shape, but providing a flat first water-absorbent polymer-containing layer improves workability and durability, which is particularly effective when there is a step around a gap in an object.

[0077] The first water-absorbent polymer-containing layer and the second water-absorbent polymer-containing layer both swell by contact with water, but the swelling rate of the second water-absorbent polymer-containing layer is preferably higher than that of the first water-absorbent polymer-containing layer. The second water-absorbent polymer-containing layer swells faster by contact with water, thereby filling the gaps in the object and stopping water in a short time. On the other hand, the swelling rate of the first water-absorbent polymer-containing layer is lower than that of the second water-absorbent polymer-containing layer, thereby improving the adhesion around the gaps in the object.

[0078] In the present invention, the expansion rate is measured by the following method.

[0079] The water-absorbing polymer layer is cut out from the waterproof film to obtain a test piece. The mass of the obtained test piece is measured. The test piece is immersed in water and the mass of the test piece is measured after 1200 seconds. The swelling rate is calculated by the following formula.

[0080] Swelling rate (g / sec) = (mass after immersion - mass before immersion) / immersion time

[0081] From the viewpoint of further improving the durability of the waterproof film, the expansion rate of the second water-absorbing polymer-containing layer is preferably 1.5 to 5 times, more preferably 1.5 to 3 times, the expansion rate of the first water-absorbing polymer-containing layer.

[0082] The length and width of the water-absorbent polymer layer are not particularly limited. The water-absorbent polymer layer may be arranged to cover a portion of the surface of the water-permeable substrate. However, from the viewpoint of stopping water in a shorter time, the water-absorbent polymer layer is preferably arranged to completely cover the water-permeable substrate.

[0083] When the water-absorbent polymer layer has a first water-absorbent polymer layer and a second water-absorbent polymer layer, the first water-absorbent polymer layer is preferably arranged to cover the entire surface of the water-permeable substrate. The thickness of the first water-absorbent polymer layer is not particularly limited, but is preferably 5 mm or less, more preferably 3 mm or less, and further preferably 2 mm or less. The thinner the first water-absorbent polymer layer is, the easier it is to follow the surrounding shape of the gap of the object, and it is possible to stop water in a shorter time and is easy to construct. From the perspective of strength, the lower limit of the thickness of the first water-absorbent polymer layer is, for example, 1 mm.

[0084] The second water-absorbent polymer-containing layer is preferably disposed only on a portion of the surface of the first water-absorbent polymer-containing layer so that the cross-sectional shape becomes a convex shape. The width of the portion where the first water-absorbent polymer-containing layer and the second water-absorbent polymer-containing layer are in contact can be appropriately adjusted, for example, to 5 mm to 50 mm. The thickness of the second water-absorbent polymer-containing layer is not particularly limited, but is preferably 5 mm to 30 mm from the viewpoint of workability.

[0085] In addition, Figure 2 In the figure, the interface between the water-permeable substrate 10 and the water-absorbent polymer-containing layer 20 is clear. However, in reality, a part of the water-absorbent polymer-containing layer 20 may penetrate into the water-permeable substrate 10, so that the interface may not be clear.

[0086] Here, the form in which a part of the water-absorbent polymer layer penetrates into the water-permeable substrate refers to the form in which the water-absorbent polymer layer enters the water-permeable substrate. In other words, a mixed region in which a part of the water-absorbent polymer layer is mixed is formed on the water-permeable substrate. For example, in the case of using a non-woven fabric as a water-permeable substrate, a part of the water-absorbent polymer penetrates from the surface of the non-woven fabric and fills the gaps between the fibers of the non-woven fabric with the water-absorbent polymer. In addition, the thickness of the water-permeable substrate refers to the thickness including the mixed region. And, the thickness of the water-absorbent polymer layer refers to the thickness excluding the mixed region.

[0087] The water-absorbent polymer contained in the water-absorbent polymer-containing layer is not particularly limited as long as it is a polymer having a function of swelling upon contact with water, and a generally known water-absorbent polymer can be used.

[0088] "Water absorption" means that the water absorption measured by method A described in JIS K 7209: 2000 (ISO62: 1999) is 12% or more. The water absorption is the percentage of the mass change relative to the initial mass. The water absorption is preferably 15% or more, and more preferably 20% or more. From the viewpoint of durability, the upper limit of the water absorption is preferably 60% or less, and more preferably 50% or less.

[0089] Examples of the water-absorbing polymer include (meth)acrylic acid polymers, vinyl polymers, polyurethanes, and polysaccharides, and examples of the water-absorbing polymer include hydrophilic polyesters, gelatin, starch / sodium acrylate graft copolymers, and isobutylene / maleic anhydride copolymers.

[0090] From the viewpoint of water stopping property, the water-absorbing polymer preferably contains at least one polymer selected from the group consisting of (meth)acrylic polymers, vinyl polymers, polyurethanes and polysaccharides, and more preferably contains at least one polymer selected from the group consisting of (meth)acrylic polymers and polyurethanes.

[0091] In particular, when the water-absorbent polymer-containing layer has a first water-absorbent polymer-containing layer and a second water-absorbent polymer-containing layer, the water-absorbent polymer contained in the first water-absorbent polymer-containing layer preferably includes an acrylic acid / sodium acrylate copolymer, and the water-absorbent polymer contained in the second water-absorbent polymer-containing layer preferably includes a (meth)acrylic polymer or polyurethane, and more preferably includes polyurethane. In addition, it is preferred that the water-absorbent polymer contained in the first water-absorbent polymer-containing layer includes an acrylic acid / sodium acrylate copolymer, and the water-absorbent polymer contained in the second water-absorbent polymer-containing layer includes a (meth)acrylic polymer or polyurethane.

[0092] The (meth)acrylic polymer refers to a polymer containing a structural unit derived from a monomer having a (meth)acryloyl group. The (meth)acrylic polymer may be either a homopolymer or a copolymer.

[0093] As a monomer which has a (meth)acryloyl group, (meth)acrylic acid, (meth)acrylamide, and (meth)acrylate are mentioned, for example.

[0094] Examples of the (meth)acrylamide include acrylamide, methacrylamide, N-methylacrylamide, N,N′-dimethylacrylamide, N,N′-dimethylmethacrylamide, and N-methylolacrylamide.

[0095] The (meth)acrylate is preferably an alkyl (meth)acrylate, and more preferably an alkyl (meth)acrylate having an alkyl moiety with 1 to 4 carbon atoms. Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and isobutyl (meth)acrylate.

[0096] Examples of the (meth)acrylic acid polymer include polyacrylic acid, polymethacrylic acid, polyacrylic acid salts, crosslinked polyacrylic acid, crosslinked polyacrylic acid salts, acrylic acid / acrylic acid salt copolymers, polyacrylamide, polymethacrylamide, acrylamide / acrylic acid copolymers, acrylamide-methacrylic acid copolymers, acrylamide / methyl acrylate copolymers, acrylamide-methyl methacrylate copolymers, N,N'-dimethylacrylamide / N-hydroxymethylacrylamide / methyl methacrylate copolymers, polymethyl (meth)acrylate, polyethyl (meth)acrylate, polybutyl (meth)acrylate, and polyisobutyl (meth)acrylate.

[0097] The weight average molecular weight of the (meth)acrylic polymer is preferably 100,000 to 10,000,000, more preferably 250,000 to 5,000,000, and even more preferably 500,000 to 2,500,000.

[0098] In the present invention, the weight average molecular weight refers to the value obtained by gel permeation chromatography (GPC). When measuring by gel permeation chromatography (GPC), HLC (registered trademark) -8020GPC (manufactured by Tosoh Corporation) is used as a measuring device, 3 TSKgel (registered trademark) Super Multipore HZ-H (4.6 mmID × 15 cm, manufactured by Tosoh Corporation) are used as columns, and THF (tetrahydrofuran), NMP (N-methylpyrrolidone), DMF (dimethylformamide) or water is used as an eluent. In addition, an RI detector is used for measurement, wherein the sample concentration is set to 0.45% by mass, the flow rate is set to 0.35 ml / min, the sample injection amount is set to 10 μl, and the measurement temperature is set to 40°C. The calibration curve was prepared using eight samples of "TSK standard, polystyrene" manufactured by Tosoh Corporation: "F-40", "F-20", "F-4", "F-1", "A-5000", "A-2500", "A-1000" and "n-propylbenzene".

[0099] The ethylene-based polymer refers to a polymer containing a structural unit derived from a monomer having a vinyl group. The ethylene-based polymer may be either a homopolymer or a copolymer.

[0100] Examples of the monomer having a vinyl group include vinyl acetate, vinyl pyrrolidone, and vinyl methyl ether.

[0101] Examples of the vinyl polymer include polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl polypyrrolidone, and polyvinyl methyl ether.

[0102] The polyurethane can be selected from known polyurethanes having water absorption. As the polyurethane, for example, a polyurethane formed by reacting a compound containing active hydrogen with an isocyanate can be cited. As a preferred polyurethane, for example, a polyurethane formed by reacting a polyalkylene oxide, a diol having a molecular weight of 500 or less, and a diisocyanate can be cited. The polyalkylene oxide and the diisocyanate contribute to the formation of the soft segment. The diol and the diisocyanate having a molecular weight of 500 or less contribute to the formation of the hard segment.

[0103] Examples of active hydrogen-containing compounds include compounds having a hydroxyl group. Examples of compounds having a hydroxyl group include polyalkylene oxides and low molecular weight diols. One or more active hydrogen-containing compounds may be used.

[0104] As polyalkylene oxide, for example, polyethylene oxide and polypropylene oxide can be mentioned. The polyalkylene oxide preferably contains polyethylene oxide. The polyalkylene oxide is preferably at least one selected from the group consisting of polyethylene oxide and polypropylene oxide, and more preferably polyethylene oxide. One or more polyalkylene oxides can also be used. The polyalkylene oxide can also be polyethylene oxide and polypropylene oxide.

[0105] When polyethylene oxide and polypropylene oxide are used in combination, the ratio of the total mass of polypropylene oxide to the total mass of polyethylene oxide (i.e., [total mass of polypropylene oxide] / [total mass of polyethylene oxide]) is preferably 0.10 to 0.35, more preferably 0.15 to 0.30, and even more preferably 0.15 to 0.25.

[0106] The weight average molecular weight of the polyalkylene oxide is preferably 3,000 to 100,000, more preferably 3,000 to 80,000, and even more preferably 3,000 to 60,000.

[0107] The weight average molecular weight of polyethylene oxide is preferably 10,000 to 100,000, more preferably 20,000 to 80,000, and further preferably 30,000 to 60,000.

[0108] The weight average molecular weight of the polypropylene oxide is preferably 3,000 to 50,000, more preferably 3,000 to 30,000, and even more preferably 3,000 to 10,000.

[0109] As the low molecular weight diol, for example, a diol having a molecular weight of 500 or less can be cited. The lower limit of the molecular weight of the diol can be 62. As the low molecular weight diol, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, hexanediol, octanediol, glyceryl monoacetate, glyceryl monobutyrate, 1,6-hexanediol and 1,9-nonanediol can be cited. The low molecular weight diol is preferably 1,4-butanediol. One or more low molecular weight diols can also be used.

[0110] As isocyanate, for example, diisocyanate can be mentioned. As diisocyanate, for example, aliphatic diisocyanate and aromatic diisocyanate can be mentioned. As specific diisocyanate, for example, 4,4'-diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, 1,8-dimethylbenzene-2,4-diisocyanate, 2,4-toluene diisocyanate, 2,2'-dimethyl-4,4'-diphenylmethane diisocyanate, 1,3-bis(isocyanate methyl)benzene, 1,4-bis(isocyanate methyl)benzene, 1,3-bis(isocyanate methyl)cyclohexane, 1,4-bis(isocyanate methyl)cyclohexane, 4,4'-dicyclohexylmethane diisocyanate and isophorone diisocyanate can be mentioned. Diisocyanate is preferably 4,4'-diphenylmethane diisocyanate. One or more isocyanates can also be used.

[0111] The polyurethane may be a commercially available product, for example, a highly water-absorbent thermoplastic polyurethane elastomer manufactured by BASF (trade name: Elastollan BO38) and a hydrophilic polyurethane manufactured by SUMITOMO SEIKA CHEMICALS CO., LTD. (trade names: AQUACALK C, AQUACALK TWB, and AQUACALK TWB-P).

[0112] Examples of the polysaccharides include alginate, xanthan gum, gellan gum, tragacanth gum, karaya gum, gum arabic, carrageenan, dextrin, agar, pectin, pullulan, locust bean gum, SACRAN, tamarind gum, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, carboxymethyl ethyl cellulose, hydroxypropyl cellulose salt, carboxymethyl cellulose salt, carboxymethyl ethyl cellulose salt, cellulose nanofibers (Tempo oxidized cellulose nanofibers, carboxymethylated cellulose nanofibers, phosphated cellulose nanofibers, cellulose nanofibers by mechanical fibrillation), chitosan nanofibers, cellulose microfibrils, hyaluronates, and hyaluronic acid.

[0113] The water-absorbent polymer-containing layer can be formed, for example, by placing a composition for a water-absorbent polymer-containing layer containing a water-absorbent polymer in a mold having a convex cross-sectional shape and drying the composition.

[0114] The composition for the water-absorbent polymer layer may contain, in addition to the water-absorbent polymer, components such as a solvent, an ultraviolet absorber, an antioxidant, a crosslinking agent, a surfactant, a filler, a colorant, a light stabilizer, a thickener, and a polymerization initiator.

[0115] (Adhesive layer)

[0116] The adhesive layer is a layer having an adhesive function. The adhesive layer preferably contains at least one adhesive component. As the adhesive component, for example, silicone resin, acrylic resin, vinyl resin, polyurethane, polyamide, polyester, polyolefin and rubber can be cited.

[0117] In the present invention, "adhesion" means adhering to a member (eg, glass) and being able to be peeled off, and is different from "bonding".

[0118] Examples of the silicone resin include addition reaction type silicone resins, peroxide curing type silicone resins, and condensation type silicone resins.

[0119] Examples of the acrylic resin include homopolymers of acrylic acid ester compounds and copolymers of acrylic acid ester compounds and other monomers.

[0120] Examples of the acrylate compound include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, and glycidyl methacrylate. Examples of other monomers include vinyl acetate, (meth)acrylonitrile, (meth)acrylamide, styrene, methacrylic acid, acrylic acid, itaconic acid, hydroxymethyl acrylamide, and maleic anhydride.

[0121] Examples of the vinyl resin include polyvinyl alcohol and polyvinyl pyrrolidone.

[0122] Examples of polyurethane include polyester polyurethane and polycarbonate polyurethane.

[0123] Examples of the polyamide include a polyamide obtained by ring-opening polycondensation of undecanolactam (amide 11) and a polyamide obtained by ring-opening polycondensation of laurolactam (amide 12).

[0124] Examples of the polyester include polycondensates of polycarboxylic acids and polyols, and specific examples include polyethylene terephthalate and polybutylene terephthalate.

[0125] As polyolefins, homopolymers of olefins and copolymers of olefins with other monomers can be cited. Olefins are preferably olefins having 2 to 6 carbon atoms, for example, ethylene, propylene, butene, methylpentene and hexene can be cited. As copolymers of olefins with other monomers, for example, EVA (ethylene-vinyl acetate copolymer resin), EAA (ethylene-acrylic acid copolymer), EEA (ethylene-ethyl acrylate copolymer) and EMMA (ethylene-methyl methacrylate copolymer) can be cited.

[0126] Examples of rubber include styrene / butadiene copolymers (SBR (Styrene-butadiene rubber), SBS (Styrene-butadiene-Styrene), styrene / isoprene copolymers (SIS (Styrene-Isoprene-Styrene), acrylonitrile-butadiene copolymers (NBR (nitrile-butadiene rubber)), chloroprene polymers, and isobutylene / isoprene copolymers (butyl rubber).

[0127] The adhesive layer can be formed, for example, by applying an adhesive layer composition containing an adhesive component to the water-absorbent polymer layer and drying the adhesive layer composition. In addition to the adhesive component, the adhesive layer composition may also contain components such as a solvent, an ultraviolet absorber, an antioxidant, a crosslinking agent, a surfactant, a filler, a colorant, a light stabilizer, a thickener, and a polymerization initiator.

[0128] The adhesive layer may be an adhesive body obtained by peeling off the release liner of a commercially available double-sided adhesive sheet or double-sided adhesive tape. The adhesive layer may be formed by attaching an adhesive body obtained by peeling off the release liner of a commercially available double-sided adhesive sheet or double-sided adhesive tape to the water-absorbent polymer-containing layer.

[0129] Furthermore, for example, the adhesive layer composition containing an adhesive component can be placed in a mold having a convex cross-sectional shape to mold the adhesive layer into a convex shape. The water-absorbent polymer-containing layer can be formed by pouring a water-absorbent polymer-containing composition into the molded adhesive layer.

[0130] The thickness of the adhesive layer is not particularly limited, and is, for example, 10 μm to 500 μm.

[0131] <Modification>

[0132] -Variation 1, 2-

[0133] like Figure 2As shown, in the waterproof film 100, the water-absorbent polymer-containing layer 20 has, in order: a flat first water-absorbent polymer-containing layer 20A on the surface of the water-permeable substrate 10; and a second water-absorbent polymer-containing layer 20B having a triangular cross-sectional shape on the surface of the first water-absorbent polymer-containing layer 20A. However, the cross-sectional shape of the water-absorbent polymer-containing layer is not limited thereto.

[0134] For example, Figure 3A As shown, in the waterproof membrane 200, the water-absorbent polymer layer 21 sequentially includes: a flat first water-absorbent polymer layer 21A on the surface of the water-permeable substrate 11; and a second water-absorbent polymer layer 21B having a quadrilateral cross-sectional shape on the surface of the first water-absorbent polymer layer 21A.

[0135] And, for example, Figure 3B As shown, in the waterproof membrane 300, the water-absorbent polymer layer 22 includes, in sequence: a flat first water-absorbent polymer layer 22A on the surface of the water-permeable substrate 12; and a second water-absorbent polymer layer 22B having a stepped cross-sectional shape on the surface of the first water-absorbent polymer layer 22A whose width decreases discontinuously in a direction away from the water-permeable substrate 12.

[0136] As described above, the cross-sectional shape of the water-absorbent polymer-containing layer is preferably a tapered shape whose width decreases in the direction away from the water-permeable substrate. Specifically, the cross-sectional shape of the water-absorbent polymer-containing layer is preferably Figure 2 or Figure 3B The form shown.

[0137] - Modification 3-

[0138] like Figure 2 As shown in FIG. 1 , in the waterproof film 100 , the adhesive layer 30 is provided so as to cover the surfaces of the first water-absorbent polymer-containing layer 20A and the second water-absorbent polymer-containing layer 20B. Figure 3A As shown in FIG. 2 , in the waterproof film 200 , the adhesive layer 31 is provided so as to cover the surfaces of the first water-absorbing polymer-containing layer 21A and the second water-absorbing polymer-containing layer 21B. Figure 3B As shown in FIG. 1 , in the waterproof film 300 , the adhesive layer 32 is provided so as to cover the surfaces of the first water-absorbent polymer-containing layer 22A and the second water-absorbent polymer-containing layer 22B. However, the arrangement of the adhesive layer is not limited to this.

[0139] like Figure 3CAs shown, in the waterproof membrane 400, the water-absorbent polymer layer 23 comprises, in sequence: a flat first water-absorbent polymer layer 23A on the surface of a water-permeable substrate 13; and a second water-absorbent polymer layer 23B having a triangular cross-sectional shape on the surface of the first water-absorbent polymer layer 23A, and the adhesive layer 33 is arranged to cover only the surface of the first water-absorbent polymer layer 23A.

[0140] When the waterproof film 400 is used, waterproofing can be performed by inserting the second water-absorbent polymer-containing layer 23B into the gap of the object and pressing the surface of the adhesive layer 33 around the gap of the object. That is, the adhesive layer only needs to be provided on at least a part of the surface of the water-absorbent polymer-containing layer, and at least on the surface of the first water-absorbent polymer-containing layer.

[0141] - Modification 4-

[0142] like Figure 3A As shown in FIG. 1 , in the waterproof film 200 , the water-absorbing polymer-containing layer 21 includes a first water-absorbing polymer-containing layer 21A and a second water-absorbing polymer-containing layer 21B in this order. However, the layer structure of the water-absorbing polymer-containing layer is not limited to this.

[0143] like Figure 3D As shown, in the waterproof membrane 500 , the water-absorbent polymer-containing layer 24 is composed only of the second water-absorbent polymer-containing layer 24B having a quadrangular cross-sectional shape, and the adhesive layer 34 is provided to cover the surface of the water-permeable substrate 14 and the second water-absorbent polymer-containing layer 24B.

[0144] Example

[0145] Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples.

[0146] <Preparation of Composition 1 for Water-Absorbent Polymer Layer>

[0147] 8 parts by mass of aluminum glycinate were added to 600 parts by mass of glycerol and stirred. Then, 100 parts by mass of acrylic acid / sodium acrylate copolymer (product name "VISCOMATE NP-700", manufactured by SHOWA DENKO KK) was added and stirred. Furthermore, a previously prepared aqueous solution of tartaric acid (240 parts by mass of purified water and 0.8 parts by mass of tartaric acid) was added and stirred to obtain a composition 1 for a water-absorbent polymer layer.

[0148] <Preparation of Composition 2 for Water-Absorbent Polymer Layer>

[0149] 2.0 g of polyurethane (trade name "AQUACORK TWB-P", manufactured by SUMITOMO SEIKA CHEMICALS CO., LTD.) and 0.4 g of a plasticizer (product name "ADEKACIZER RS-1000", manufactured by ADEKA CORPORATION) were mixed to obtain a composition 2 for a water-absorbent polymer layer.

[0150] [Example 1]

[0151] A mold hollowed out into a quadrilateral cross-sectional shape is prepared.

[0152] After the water-absorbent polymer layer-containing composition 2 was poured into the prepared mold using a slot die, a nonwoven fabric (product name "KURASEAL", manufactured by Kuraray Kuraflex Co., Ltd., basis weight 130 g / m2) was placed as a water-permeable substrate. 2 , elongation 200%), and heat treatment was performed at 150°C for 60 seconds to form a water-absorbent polymer layer having a quadrilateral cross-sectional shape on the nonwoven fabric. A PVA film (manufactured by KURARAY CO., LTD.) was attached to the nonwoven fabric and the water-absorbent polymer layer to form an adhesive layer, and a nonwoven fabric having a water-absorbent polymer layer was obtained. Figure 3D The water-stop membrane has the cross-sectional shape shown. The width of the water-absorbent polymer layer is 20 mm.

[0153] [Example 2]

[0154] A mold was prepared which was hollowed out to be flat and further hollowed out in the longitudinal direction to have a quadrilateral cross-sectional shape.

[0155] After the water-absorbent polymer layer-containing composition 2 was poured into the portion of the prepared mold hollowed out into a quadrilateral cross-section using a slit die, a heat treatment was performed at 150° C. for 60 seconds. Furthermore, after the water-absorbent polymer layer-containing composition 1 was poured into the flat portion of the prepared mold, a nonwoven fabric (product name "KURASEAL", manufactured by Kuraray Kuraflex Co., Ltd., basis weight 130 g / m2) was placed as a water-permeable substrate. 2 , elongation 200%), and drying treatment was carried out with hot air at 80°C at 10 m / sec to form a flat first water-absorbent polymer layer on the nonwoven fabric, and a second water-absorbent polymer layer having a quadrilateral cross-sectional shape was formed on the surface of the first water-absorbent polymer layer. A PVA film (manufactured by KURARAY CO., LTD.) was attached to the nonwoven fabric and the water-absorbent polymer layer to form an adhesive layer, and a nonwoven fabric having Figure 3AThe waterproof membrane has the cross-sectional shape shown. The thickness of the first water-absorbent polymer-containing layer is 1.5 mm. The width and thickness of the second water-absorbent polymer-containing layer are 20 mm and 20 mm respectively.

[0156] [Example 3]

[0157] A mold was prepared which was hollowed out to be flat and further hollowed out in the longitudinal direction to have a triangular cross-section.

[0158] Except for changing the mold, the same method as in Example 2 was used to obtain Figure 2 The maximum width of the second water-absorbent polymer-containing layer is 20 mm, and the thickness is 20 mm.

[0159] [Example 4]

[0160] The water-permeable substrate was changed to a nonwoven fabric (product name "Clearsil", manufactured by KURARAY CO., LTD.), basis weight 130 g / m 2 , elongation 300%), except that the same method as in Example 2 was used to obtain Figure 3A Waterstop membrane with the cross-sectional shape shown.

[0161] [Example 5]

[0162] The water-permeable substrate was changed to a nonwoven fabric (product name "Clearsil", manufactured by KURARAY CO., LTD.), basis weight 200 g / m 2 , elongation 200%), except that the same method as in Example 2 was used to obtain Figure 3A Waterstop membrane with the cross-sectional shape shown.

[0163] [Example 6]

[0164] A waterproof film was obtained in the same manner as in Example 2 except that the water-absorbent polymer layer-containing composition 2 was poured into the flat portion of the prepared mold.

[0165] [Comparative Example 1]

[0166] A mold hollowed out into a flat shape is prepared.

[0167] After pouring the composition 1 for the water-absorbent polymer layer into the prepared mold using a slit die, a nonwoven fabric (product name "KURASEAL", manufactured by Kuraray Kuraflex Co., Ltd.) was placed as a water-permeable substrate, and a heat treatment was performed at 150°C for 60 seconds to form a flat first water-absorbent polymer layer on the nonwoven fabric. A PVA film (manufactured by KURARAY CO., LTD.) was attached to the first water-absorbent polymer layer to form an adhesive layer, thereby obtaining a waterproof film. The thickness of the first water-absorbent polymer layer was 1.5 mm.

[0168] [Comparative Example 2]

[0169] A waterproof membrane was obtained in the same manner as in Example 2 except that the water-permeable substrate was not provided.

[0170] [Comparative Example 3]

[0171] A waterproof film was obtained in the same manner as in Example 2 except that the adhesive layer was not provided.

[0172] The durability, workability, and water-stopping time of the produced waterproof membrane were evaluated by the following method.

[0173] Durability

[0174] A water tank with a hole of 500mm in width and 10mm in height at the lower part of the wall was used as an experimental water tank (width 600mm, height 700mm, depth 20mm). Water was added to the experimental water tank to a height of 500mm. A water-stop film was attached to the bottom and wall surface of the inner side of the water tank in such a way that the protruding part of the water-stop film was located in the hole. The time from the point when the water flowing out of the hole stopped to the point when the water flowed out of the hole again (i.e., the water-stopping duration) was measured. The evaluation criteria are as follows. It can be said that the longer the water-stopping duration, the better the durability.

[0175] A: The water stopping duration is more than 72 hours.

[0176] B: The water stopping duration is more than 24 hours and less than 72 hours.

[0177] C: Waterstop duration is less than 24 hours.

[0178] <Construction performance>

[0179] In order to evaluate the construction performance, an experimental wall was prepared. A U-shaped hole consisting of a horizontal slit with a width of 1800 mm and a height of 10 mm and a vertical slit with a height of 600 mm and a width of 10 mm connected to both ends of the horizontal slit was provided at the lower part of the experimental wall. The waterproof film was attached in such a way that the protruding part of the waterproof film was located in the hole. The time required for construction (i.e., construction time) was measured. The evaluation criteria are as follows. It can be said that the shorter the construction time, the better the construction performance.

[0180] A: The construction time is less than 3 minutes.

[0181] B: Construction time is more than 3 minutes and less than 5 minutes.

[0182] C: Construction time exceeds 5 minutes.

[0183] <Water stop time>

[0184] A water tank with a hole of 500mm in width and 10mm in height at the lower part of the wall was used as an experimental water tank (width 600mm, height 700mm, depth 20mm). Water was added to the experimental water tank to a height of 500mm. A water-stop film was attached to the bottom and wall of the inner side of the water tank in such a way that the protruding part of the water-stop film was located in the hole. The time when the water addition was stopped was taken as the starting time, and the time until the water stopped flowing out of the hole (i.e., the water-stop time) was measured. The evaluation criteria are as follows.

[0185] A: The water stopping time is less than 3 hours.

[0186] B: The water stop time is more than 3 hours and less than 12 hours.

[0187] C: Water stopping time exceeds 12 hours.

[0188] Table 1 shows the evaluation results.

[0189] In Table 1, the "swelling rate ratio" refers to the ratio of the swelling rate of the second water-absorbent polymer-containing layer to the swelling rate of the first water-absorbent polymer-containing layer.

[0190] [Table 1]

[0191]

[0192] As shown in Table 1, it can be seen that in Examples 1 to 6, since the water-permeable substrate, the water-absorbent polymer layer and the adhesive layer are provided in this order, and the water-absorbent polymer layer has a cross-sectional shape in which at least a portion protrudes in a direction away from the water-permeable substrate, the waterproofing duration is long and the durability is excellent.

[0193] On the other hand, in Comparative Example 1, the water-absorbent polymer-containing layer was flat and was found to be inferior in durability.

[0194] It is found that in Comparative Example 2, no water-permeable base material is provided, and the durability is poor.

[0195] It is found that in Comparative Example 3, no adhesive layer is provided and the durability is poor.

[0196] In Example 2, the water-absorbent polymer-containing layer includes a flat first water-absorbent polymer-containing layer and a convex second water-absorbent polymer-containing layer in cross section. Therefore, compared with Example 1, the durability is excellent and the water stopping time can be shortened.

[0197] Furthermore, it is found that in Example 2, the expansion rate of the second water-absorbent polymer-containing layer is higher than the expansion rate of the first water-absorbent polymer-containing layer, and therefore the durability is superior to that of Example 1.

[0198] Furthermore, it is found that in Example 3, since the cross-sectional shape of the water-absorbent polymer-containing layer is a tapered shape in which the width decreases in the direction away from the water-permeable substrate, the workability is superior to that in Example 2.

[0199] In addition, the disclosure of Japanese Patent Application No. 2022-135048 filed on August 26, 2022 is incorporated in its entirety into this specification by reference. Furthermore, all documents, patent applications, and technical standards described in this specification may be cited in this specification by reference to the same extent as if each document, patent application, and technical standard were specifically and separately described as being cited by reference.

Claims

1. A waterproof membrane comprising a water-permeable substrate, a water-absorbent polymer-containing layer, and an adhesive layer in this order, wherein the water-absorbent polymer-containing layer has a cross-sectional shape in which at least a portion of the layer protrudes in a direction away from the water-permeable substrate.

2. The waterproof membrane according to claim 1, wherein: The water-absorbing polymer layer comprises, in order: a flat first water-absorbent polymer-containing layer on the surface of the water-permeable substrate; and The cross-sectional shape on the surface of the first water-absorbent polymer-containing layer is a second water-absorbent polymer-containing layer having a convex shape.

3. The waterproof membrane according to claim 2, wherein: The second water-absorbent polymer-containing layer has a higher expansion rate than the first water-absorbent polymer-containing layer.

4. The waterproof membrane according to claim 3, wherein: The expansion rate of the second water-absorbent polymer-containing layer is 1.5 to 5 times the expansion rate of the first water-absorbent polymer-containing layer.

5. The waterproof membrane according to claim 1 or 2, wherein: The cross-sectional shape of the water-absorbent polymer-containing layer is a tapered shape whose width decreases in a direction away from the water-permeable substrate.

6. The waterproof membrane according to claim 1 or 2, wherein: The elongation of the water-permeable substrate is 100% to 300%.

7. The waterproof membrane according to claim 1 or 2, wherein: The basis weight of the water-permeable substrate is 100 g / m 2 ~200g / m 2 .

8. The waterproof membrane according to claim 1 or 2, wherein: The water permeable substrate is nonwoven fabric, cloth or paper.

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