Waterproofing sheet for residential base

Abstract

To provide a watertight sheet for a housing substrate with excellent performance in inhibiting water infiltration through a through-hole, even when the through-hole is formed by a nail or the like.SOLUTION: There is provided a watertight sheet 1 for a housing substrate, which is composed by laminating at least a front side nonwoven fabric layer 2, a cloth sheet 3, a film 4, and a back side nonwoven fabric layer 5, in which the back side nonwoven fabric layer 5 contains water absorbent resin, the front side nonwoven fabric layer 2 and the back side nonwoven fabric layer 5 each contain a nonwoven fabric made of polyolefin resin as the base material, and the fluff thickness d1 of the front side nonwoven fabric layer 2 is greater than the fluff thickness d2 of the back side nonwoven fabric layer 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a waterproof sheet for residential foundations, which is formed by laminating at least a front nonwoven fabric layer, a cloth sheet, a film, and a back nonwoven fabric layer. [Background technology]

[0002] Conventionally, mortar finishes have been applied to the walls of buildings such as houses. In mortar finishes, when a mortar material before hardening is applied to a base such as crossbeams or wooden lath (hereinafter simply referred to as "base"), a waterproof sheet such as asphalt felt or tar felt is attached to the surface of the base to prevent the moisture contained in the mortar material from wetting the base and to prevent rainwater from penetrating into the base through the mortar after the mortar material has hardened (see, for example, Patent Document 1). The waterproof sheet of Patent Document 1 is attached to the outside with nails, tackers, etc. (hereinafter also referred to as "nails, etc.") together with reinforcing materials such as wire mesh or metal lath, and the mortar material is applied to the base via the reinforcing materials.

[0003] Furthermore, a waterproof sheet has been proposed in which a stretchable and adhesive resin layer is formed on the surface of a fabric in order to prevent moisture from penetrating through through-holes (see, for example, Patent Document 2). According to the waterproof sheet of Patent Document 2, when a through-hole is formed by hammering a nail or the like into the sheet, the stretchable and adhesive resin layer aggregates around the nail or the like, thereby preventing moisture from penetrating. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 1-105732 [Patent Document 2] Japanese Patent Application Publication No. 2-269277 Summary of the Invention [Problem to be solved by the invention]

[0005] When through holes are formed in the waterproof sheet described in Patent Document 1 by hammering nails or the like, moisture contained in the mortar material, rainwater, and the like may infiltrate through the through holes.

[0006] In the waterproof sheet described in Patent Document 2, it is difficult for the resin layer to sufficiently block the through-holes, and it is difficult to say that the waterproof sheet can sufficiently prevent moisture from penetrating through the through-holes.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a waterproof sheet for residential underlayment that has excellent performance in preventing moisture from penetrating through holes, even if such holes are formed by nails or the like. [Means for solving the problem]

[0008] The characteristic configuration of the waterproof sheet for residential foundations according to the present invention to solve the above problems is as follows: A waterproof sheet for a residential base comprising at least a surface nonwoven fabric layer, a cross sheet, a film, and a back nonwoven fabric layer laminated together, The back nonwoven fabric layer contains a water-absorbent resin.

[0009] According to the water stop sheet for residential foundations of this configuration, the top nonwoven fabric layer is laminated, allowing this top nonwoven fabric layer to adhere closely to mortar. The laminated cross sheet increases the tensile strength of the water stop sheet for residential foundations, making it less likely to tear when pulled to attach it to the substrate. The laminated film allows the water stop sheet for residential foundations to prevent moisture penetration in areas other than through holes (hereinafter simply referred to as "through holes") made by nails or the like. The laminated back nonwoven fabric layer allows this back nonwoven fabric layer to come into contact with the substrate. Furthermore, since the back nonwoven fabric layer contains a water-absorbent resin, when through holes are formed in the water stop sheet for residential foundations, moisture from the mortar material or rainwater passes through the through holes, and the water-absorbent resin absorbs the moisture and swells. The swollen water-absorbent resin seals the gap between the through holes and the nails or the like, preventing moisture from penetrating through the through holes. Furthermore, since the water-absorbing resin is present on the substrate side of the film, the water-absorbing resin absorbs moisture that has penetrated through the through-holes in the film, and swells to block the through-holes, thereby preventing further penetration of moisture.

[0010] In the waterproof sheet for residential foundation according to the present invention, the front nonwoven fabric layer and the back nonwoven fabric layer each contain a nonwoven fabric made of a polyolefin resin as a base material, The fluff thickness of the front nonwoven fabric layer is preferably greater than the fluff thickness of the back nonwoven fabric layer.

[0011] Polyolefin resins are alkali-resistant resins. Therefore, according to the waterproof sheet for residential foundations of this configuration, the front nonwoven fabric layer and the back nonwoven fabric layer each contain a nonwoven fabric made from a polyolefin resin as a base material. Therefore, when a mortar material is applied to the waterproof sheet for residential foundations, the front nonwoven fabric layer and the back nonwoven fabric layer are prevented from being solubilized or denatured by the alkaline components contained in the mortar material. Furthermore, because the fluff thickness of the front nonwoven fabric layer is greater than that of the back nonwoven fabric layer, the anchoring effect between the front nonwoven fabric layer and the mortar is enhanced, resulting in excellent adhesion to the mortar. Furthermore, by making the fluff thickness of the front nonwoven fabric layer greater than that of the back nonwoven fabric layer (i.e., making the fluff thickness of the back nonwoven fabric layer smaller than that of the front nonwoven fabric layer), the water-absorbent resin can be firmly fixed to the nonwoven fabric contained as a substrate in the back nonwoven fabric layer, thereby preventing detachment of the water-absorbent resin from the back nonwoven fabric layer. Therefore, the water-absorbent resin absorbs moisture that has penetrated through the through-holes present in the film, and swells to close the through-holes, thereby preventing further penetration of moisture.

[0012] In the waterproof sheet for residential foundation according to the present invention, The nonwoven fabric made from the polyolefin resin contained in the front nonwoven fabric layer is preferably an air-through nonwoven fabric.

[0013] According to the water-stop sheet for residential basement of this configuration, the nonwoven fabric contained in the surface nonwoven fabric layer is an air-through nonwoven fabric made from polyolefin resin as a raw material, which further enhances the anchoring effect between the surface nonwoven fabric layer and mortar, thereby resulting in the water-stop sheet for residential basement having improved adhesion to mortar.

[0014] In the waterproof sheet for residential foundation according to the present invention, The nonwoven fabric made of polyolefin resin and contained in the back nonwoven fabric layer is preferably a spunbond nonwoven fabric.

[0015] In the waterproof sheet for residential foundations of this configuration, the nonwoven fabric made from a polyolefin resin contained in the back-side nonwoven fabric layer is a spunbond nonwoven fabric, which allows the water-absorbent resin to be more firmly fixed, thereby further preventing the water-absorbent resin from detaching from the back-side nonwoven fabric layer. Therefore, the water-absorbent resin absorbs moisture that has penetrated through the through-holes in the film, swelling and closing the through-holes, thereby preventing further moisture penetration.

[0016] The waterproof sheet for residential foundations according to the present invention is The surface nonwoven fabric layer and the back nonwoven fabric layer each have a basis weight of 15 to 28 g / m 2 It is preferable that:

[0017] According to the waterproof sheet for housing foundations of this configuration, the basis weight of the front nonwoven fabric layer and the back nonwoven fabric layer is 15 g / m 2 As a result, the waterproof sheet for residential foundations is resistant to tearing when pulled. In addition, the surface nonwoven fabric layer and the back nonwoven fabric layer each have a basis weight of 28 g / m 2 By satisfying the following, the waterproof sheet for residential base has improved transparency.

[0018] The waterproof sheet for residential foundations according to the present invention is The content of the water-absorbent resin in the back nonwoven fabric layer is 5 to 10 g / m 2 It is preferable that:

[0019] The waterproof sheet for residential foundations of this configuration has a water-absorbent resin content of 5 g / m in the backside nonwoven fabric layer. 2 When the content of the water-absorbent resin in the back nonwoven fabric layer is 10 g / m or more, the through-holes can be more reliably blocked by the absorption and swelling of the water-absorbent resin. 2 By satisfying the condition of 0.1 to 1.0, it is possible to further suppress the detachment of the water-absorbent resin from the backside nonwoven fabric layer. [Brief explanation of the drawings]

[0020] [Figure 1]FIG. 1 is a cross-sectional view showing a typical example of the layer structure of a waterproof sheet for house foundations according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] The waterproof sheet for residential foundations of the present invention will be described with reference to the drawings. However, the layer structure shown in the drawings has been appropriately exaggerated or simplified to facilitate explanation, and the relationship between the thickness of each layer and the scale relationship do not necessarily accurately reflect the actual waterproof sheet for residential foundations. In the following description, "front side" means the side facing the mortar, and "back side" means the side facing the substrate.

[0022] <Waterproof sheet for residential base>

[0023] 1 is a cross-sectional view showing a typical example of the layer structure of a waterproof sheet for residential foundations according to the present invention. The waterproof sheet for residential foundations 1 comprises at least a front nonwoven fabric layer 2, a cloth sheet 3, a film 4, and a back nonwoven fabric layer 5, and the back nonwoven fabric layer 5 contains a water-absorbent resin.

[0024] <Front nonwoven fabric layer> The front nonwoven fabric layer 2 is for forming mortar on this front nonwoven fabric layer 2. Specifically, the front nonwoven fabric layer 2 is for preventing the mortar from peeling off when applying a mortar material to this front nonwoven fabric layer 2 and after the applied mortar material has solidified to form mortar.

[0025] The mortar can be formed by nailing the residential foundation waterproof sheet 1 to the base, applying a mortar material to the front nonwoven fabric layer 2, and curing it to harden it. Alternatively, the back nonwoven fabric layer 5 of the residential foundation waterproof sheet 1 can be brought into contact with the base, and the front nonwoven fabric layer 2 can be covered with a conventionally known wire mesh such as lath mesh. After that, the residential foundation waterproof sheet 1 can be nailed to the base together with the wire mesh, and the mortar material can be applied to the front nonwoven fabric layer 2 through the wire mesh.

[0026] From the viewpoint of preventing the mortar from peeling off, the front-side nonwoven fabric layer 2 preferably includes a nonwoven fabric with high fluffing as a substrate. Here, the fluffing size is evaluated as fluff thickness d1, which is the average length of fluff 2a from the surface of the front-side nonwoven fabric layer 2 (baseline BL1 of the cross section of the front-side nonwoven fabric layer 2 shown in the enlarged circle X in FIG. 1 ), and fluff thickness d2, which is the average length of fluff 5a from the surface of the back-side nonwoven fabric layer 5 (baseline BL2 of the cross section of the back-side nonwoven fabric layer 5 shown in the enlarged circle Y in FIG. 1 ). In this case, the fluff thickness d1 of the front-side nonwoven fabric layer 2 is preferably greater than the fluff thickness d2 of the back-side nonwoven fabric layer 5. By making the fluff thickness d1 of the front-side nonwoven fabric layer 2 greater than the fluff thickness d2 of the back-side nonwoven fabric layer 5, the anchoring effect between the front-side nonwoven fabric layer 2 and mortar is enhanced, and the waterproof sheet for residential foundations 1 therefore has excellent adhesion to mortar. The fluff thickness d1 of the front nonwoven fabric layer 2 is preferably 100 to 600 μm, more preferably 150 to 600 μm, and even more preferably 200 to 600 μm.

[0027] The basis weight of the front nonwoven fabric layer 2 is 15 to 28 g / m 2 is preferred, and 16 to 28 g / m 2 More preferably, 17 to 28 g / m 2 It is more preferable that the basis weight of the front nonwoven fabric layer 2 is 15 g / m 2 By satisfying the above, it is possible to prevent the front nonwoven fabric layer 2 from being torn when the waterproof sheet for house foundation 1 is pulled. 2 By satisfying the following, the front nonwoven fabric layer 2 has improved transparency.

[0028] The nonwoven fabric contained as a substrate in the front nonwoven fabric layer 2 (hereinafter also referred to as "front nonwoven fabric") is preferably a nonwoven fabric made from a polyolefin resin (hereinafter also referred to as "polyolefin resin nonwoven fabric"). That is, the front nonwoven fabric layer 2 preferably contains a polyolefin resin nonwoven fabric as a substrate. When the front nonwoven fabric layer 2 contains a polyolefin resin nonwoven fabric as a substrate, the front nonwoven fabric layer 2 can be prevented from being solubilized or denatured by the alkaline components contained in the mortar material when the mortar material is applied to the waterproof sheet for residential foundations 1. Examples of polyolefin resins include polypropylene and polyethylene. Fibers made of such resins may be used alone or in combination, or may be used as core-sheath fibers. For example, when the front nonwoven fabric layer 2 is laminated with other layers including the film 4 by thermal lamination, sheath-core fibers are preferred because they can maintain the fluff thickness d1 even when heated, and in particular, sheath-core fibers made of polyolefin resins having core yarns with a higher melting point than the sheath yarns are preferred. Note that the front nonwoven fabric layer 2 can also be laminated with other layers by methods other than thermal lamination, but thermal lamination is preferred because it can reduce the number of steps, eliminate the need for adhesives, and reduce costs.

[0029] The type of polyolefin resin nonwoven fabric is not particularly limited and can be selected as appropriate. Examples of polyolefin resin nonwoven fabrics include spunbond nonwoven fabrics, meltblown nonwoven fabrics, air-through nonwoven fabrics, and needle-punched nonwoven fabrics. Among these, air-through nonwoven fabrics are preferred. That is, it is preferred that the polyolefin resin nonwoven fabric contained in the front nonwoven fabric layer 2 is an air-through nonwoven fabric. Air-through nonwoven fabrics have a greater fluff thickness than nonwoven fabrics such as spunbond nonwoven fabrics. Therefore, when the polyolefin resin nonwoven fabric contained in the front nonwoven fabric layer 2 is an air-through nonwoven fabric, the anchoring effect between the front nonwoven fabric layer 2 and mortar is further enhanced, and the waterproof sheet for residential foundations 1 has improved adhesion to mortar.

[0030] The front nonwoven fabric layer 2 may contain only the front nonwoven fabric, or may contain other additives and the like.

[0031] <Cross seat> The cross sheet 3 is intended to increase the tensile strength of the residential foundation waterproof sheet 1 and corresponds to a reinforcing material. In other words, the cross sheet 3 is a reinforcing material that prevents the residential foundation waterproof sheet 1 from being torn by pulling when and after the sheet is attached to the substrate. An example of the cross sheet 3 is a cross-shaped sheet in which polyolefin (polyethylene, polypropylene, etc.) flat yarns are aligned in two directions, vertically and horizontally. By using polyolefin flat yarns for the cross sheet 3, when a mortar material is applied to the residential foundation waterproof sheet 1, the cross sheet 3 can be prevented from being solubilized or denatured by the alkaline components contained in the mortar material.

[0032] The basis weight of the cross sheet 3 is 10 to 25 g / m 2 is preferable, and 15 to 20 g / m 2 It is more preferable that the basis weight of the cross sheet 3 is 10 g / m 2 As a result, the cross sheet 3 has a higher strength. 2 By satisfying the following, the cross sheet 3 has improved transparency.

[0033] <Film> The film 4 is intended to provide the main water-stopping property (water-stopping property of parts other than the through-holes) to the water-stop sheet for residential foundation 1, and is configured so that it does not allow moisture to pass through. The material of the film 4 is not particularly limited as long as it does not allow moisture to pass through, and can be selected as appropriate. It is also preferable that the film 4 be transparent. For example, a polyolefin film such as a polyethylene film or a polypropylene film is preferable as such a film 4. By using a polyolefin film for the film 4, it is possible to prevent the film 4 from being solubilized or denatured by the alkaline components contained in the mortar material when applying the mortar material to the water-stop sheet for residential foundation 1.

[0034] The film 4 may contain known additives, such as fillers (inorganic fillers, organic fillers, etc.), antioxidants, antistatic agents, release agents, antioxidants, UV absorbers, lightfastness agents, colorants (pigments, dyes, etc.), and nucleating agents.

[0035] The thickness of the film 4 is not particularly limited and may be set appropriately, for example, to 0.04 to 1.0 mm in consideration of transparency and water-stopping properties.

[0036] <Backside nonwoven fabric layer> The backside nonwoven fabric layer 5 is to be attached to (come into contact with) the substrate. The backside nonwoven fabric layer 5 contains a water-absorbent resin, which prevents moisture from penetrating through the through-holes formed when the residential foundation waterproof sheet 1 is attached to the substrate.

[0037] The water-absorbent resin is supported, for example, on the outer (back) surface (i.e., the back surface of the water-stop sheet for house foundations 1) of the nonwoven fabric (hereinafter also referred to as "back-side nonwoven fabric") contained as a base material in the back-side nonwoven fabric layer 5. The manner in which the water-absorbent resin is supported on the back-side nonwoven fabric is not particularly limited and can be set as appropriate; for example, the water-absorbent resin is supported in the gaps on the outer surface side of the back-side nonwoven fabric.

[0038] From the viewpoint of suppressing detachment of the water-absorbent resin, the back-side nonwoven fabric layer 5 preferably contains a nonwoven fabric with low fluff as a substrate. Furthermore, the fluff thickness d2 of the back-side nonwoven fabric layer 5 is preferably smaller than the fluff thickness d1 of the front-side nonwoven fabric layer 2 (in other words, as described above, the fluff thickness d1 of the front-side nonwoven fabric layer 2 is larger than the fluff thickness d2 of the back-side nonwoven fabric layer 5). Since the fluff thickness d2 of the back-side nonwoven fabric layer 5 is smaller than the fluff thickness d1 of the front-side nonwoven fabric layer 2, the water-absorbent resin can be firmly fixed to the back-side nonwoven fabric contained as a substrate in the back-side nonwoven fabric layer 5, thereby suppressing detachment of the water-absorbent resin from the back-side nonwoven fabric layer 5. Therefore, the water-absorbent resin absorbs moisture that has penetrated through the through-holes present in the film 4, and swells to close the through-holes, thereby preventing further penetration of moisture. The fluff thickness d2 of the backside nonwoven fabric layer 5 is preferably 30 to 100 μm, more preferably 30 to 90 μm, and even more preferably 30 to 80 μm.

[0039] The weight of the back nonwoven fabric layer 5 is 15 to 28 g / m 2 is preferred, and 16 to 28 g / m 2 More preferably, 17 to 28 g / m 2 It is more preferable that the weight of the back nonwoven fabric layer 5 is 15 g / m 2 By satisfying the above, it is possible to prevent the back-side nonwoven fabric layer 5 from being torn when the waterproof sheet for house foundation 1 is pulled. 2 By satisfying the following, the back nonwoven fabric layer 5 has improved transparency.

[0040] The back-side nonwoven fabric is preferably a polyolefin-based resin nonwoven fabric, similar to the front-side nonwoven fabric. That is, the back-side nonwoven fabric layer 5 preferably contains a polyolefin-based resin nonwoven fabric as a substrate. By including a polyolefin-based resin nonwoven fabric as a substrate, the back-side nonwoven fabric layer 5 can be prevented from being solubilized or denatured by the alkaline components contained in the mortar material when the mortar material is applied to the waterproof sheet for residential foundations 1. Examples of polyolefin-based resins include polypropylene and polyethylene. Fibers made of such resins may be used alone, in combination with multiple types, or as sheath-core fibers. For example, sheath-core fibers are preferred because they can maintain the fluff thickness d2 even when heated when the back-side nonwoven fabric layer 5 is laminated with other layers, including the film 4, by thermal lamination. In particular, sheath-core fibers made of polyolefin-based resins having a core thread with a higher melting point than the sheath thread are preferred. Although the backside nonwoven fabric layer 5 can be laminated to other layers by methods other than thermal lamination, it is preferable to use thermal lamination because it can reduce the number of steps, does not require adhesives, and can reduce costs.

[0041] The type of polyolefin-based resin nonwoven fabric is not particularly limited and can be selected appropriately. Examples of the polyolefin-based resin nonwoven fabric include spunbonded nonwoven fabrics, meltblown nonwoven fabrics, air-through nonwoven fabrics, and needle-punched nonwoven fabrics. Among these, spunbonded nonwoven fabrics are preferred. That is, it is preferred that the polyolefin-based resin nonwoven fabric contained in the back-side nonwoven fabric layer 5 is a spunbonded nonwoven fabric. Spunbonded nonwoven fabrics have a smaller fluff thickness than nonwoven fabrics such as air-through nonwoven fabrics. Therefore, when the polyolefin-based resin nonwoven fabric contained in the back-side nonwoven fabric layer 5 is a spunbonded nonwoven fabric, the water-absorbent resin can be more firmly fixed, thereby preventing detachment of the water-absorbent resin from the back-side nonwoven fabric layer 5. Therefore, the water-absorbent resin absorbs moisture that has penetrated through the through-holes present in the film 4, swells, and closes the through-holes, thereby preventing further moisture penetration.

[0042] The water-absorbent resin is not particularly limited as long as it absorbs water and swells when it comes into contact with water, and can maintain a non-fluid state in the swollen state. Examples of such water-absorbent resins include resins in which crosslinking is introduced into a water-soluble electrolyte polymer. The water-absorbent resin may be either a natural water-absorbent resin or a synthetic water-absorbent resin, but synthetic water-absorbent resins are preferred from the viewpoint of durability. Examples of materials constituting the water-absorbent resin include addition polymers such as polyvinyl alcohol-based polyvinyl alcohol crosslinked polymers, polyacrylic-based polyacrylate crosslinked bodies, sodium acrylate-vinyl alcohol copolymers, polyether-based polyethylene glycol diacrylate crosslinked polymers, maleic anhydride-based polymers, and vinylpyrrolidone-based polymers.

[0043] The water-absorbent resin is preferably supported on the back-side nonwoven fabric in the back-side nonwoven fabric layer 5 by being fixed to the back-side nonwoven fabric (e.g., its outer surface) via a binder resin. Examples of binder resins include vinyl resins, urethane resins, silicone resins, acrylic resins, epoxy resins, and ester resins. Among these, acrylic resins are preferred from the viewpoints of ease of handling during processing and cost reduction. The method for fixing (supporting) the water-absorbent resin to the back-side nonwoven fabric in the back-side nonwoven fabric layer 5 is not particularly limited, but examples include a method in which a mixed liquid consisting of a water-absorbent resin, a binder resin, and an organic solvent such as toluene is applied to the back surface of the back-side nonwoven fabric by a coating method, a gravure roll method, or the like, and then heat-treated to solidify.

[0044] The content of the water-absorbent resin in the back nonwoven fabric layer is 5 g / m 2 It is preferable that the content is 6 g / m or more. 2 The content of the water-absorbent resin in the back nonwoven fabric layer is more preferably 10 g / m or more. 2 The content of the water-absorbent resin in the back nonwoven fabric layer is preferably 5 g / m or less. 2When the content of the water-absorbent resin in the back nonwoven fabric layer is 10 g / m or more, the through-holes can be more reliably blocked by the absorption and swelling of the water-absorbent resin. 2 By satisfying the condition of 0.1 to 1.0, it is possible to further suppress the detachment of the water-absorbent resin from the backside nonwoven fabric layer.

[0045] <Method of manufacturing waterproof sheet for residential base> The waterproof sheet for residential foundations 1 can be manufactured, for example, by stacking the front nonwoven fabric layer 2, cloth sheet 3, film 4, and back nonwoven fabric layer 5 in this order and laminating them by bonding each layer using a method such as dry lamination, wet lamination, extrusion lamination, hot melt lamination, or thermal lamination. Note that the waterproof sheet for residential foundations 1 may include layers other than the front nonwoven fabric layer 2, cloth sheet 3, film 4, and back nonwoven fabric layer 5 described above.

[0046] <Characteristics of waterproof sheets for residential bases> The water stop sheet for residential foundation 1 preferably has a water retention rate of 80% or more, more preferably 85% or more. When the water retention rate is 80% or more, the water absorbent resin that swells and blocks the through-holes when water penetrates the through-holes of the water stop sheet for residential foundation 1 becomes less likely to be released from the through-holes. This makes it possible to more reliably suppress the penetration of water through the through-holes. There is no particular limitation on the upper limit of the water retention rate, and it may be 100%. The water retention rate is measured by the method described below.

[0047] In the residential foundation waterproof sheet 1, the spread of water infiltrating through the through holes in a nail hole waterproofing test (nail hole waterproofing) is preferably 20 mm or less from the through hole, and more preferably 15 mm or less. Here, the smaller the spread of water infiltrating through the through holes, the greater the amount of water absorbed by the water-absorbent resin, resulting in a higher ability to seal the through holes. In this regard, by having the nail hole waterproofing of 20 mm or less, water infiltration through the through holes can be more reliably suppressed. Furthermore, the greater the amount of water absorbed by the water-absorbent resin, the water-absorbent resin can also absorb water absorbed by the foundation from the surrounding environment, etc., making the foundation more likely to dry and less likely to rot. The lower limit of the nail hole waterproofing is not particularly limited and may be, for example, 5 mm. The nail hole waterproofing is measured using the method described below.

[0048] The waterproof sheet for residential foundations 1 preferably has an adhesion (adhesion strength) between the front nonwoven fabric layer 2 and mortar of 3 N / 25 mm or more, more preferably 3.5 N / 25 mm or more, and even more preferably 4 N / 25 mm or more. When the adhesion is 3 N / 25 mm or more, peeling of the mortar from the front nonwoven fabric layer 2 can be more reliably prevented. There is no particular upper limit to the adhesion, and it may be, for example, 10 N / 25 mm. The adhesion is measured by the method described below.

[0049] It is preferable that the water stop sheet for residential foundation 1 has transparency. If the water stop sheet for residential foundation 1 has transparency, when the water stop sheet for residential foundation 1 is laid on the substrate and nailed down with nails or the like, the substrate can be visually confirmed and the nailing position can be confirmed, making the installation work easier. The transparency of the water stop sheet for residential foundation 1 is imparted by the transparency of at least the front nonwoven fabric layer 2, the cross sheet 3, the film 4, and the back nonwoven fabric layer 5. The transparency is evaluated by the method described below. [Example]

[0050] Water stop sheets for residential foundations having the characteristic features of the present invention (Examples 1 to 4) were produced, and various measurements and evaluations were carried out. For comparison, water stop sheets for residential foundations not having the characteristic features of the present invention (Comparative Examples 1 and 2) were produced, and similar measurements and evaluations were carried out. The items measured and evaluated were the fluff thickness of the front nonwoven fabric layer and the back nonwoven fabric layer, as well as the water retention rate, nail hole water stoppage, transparency, and adhesion to mortar of the water stop sheets for residential foundations. Each item is explained below.

[0051] [Fluff thickness of the front nonwoven fabric layer and the back nonwoven fabric layer] The fluff thickness of each of the front nonwoven fabric layer and the back nonwoven fabric layer was measured using a digital microscope (for example, VHX-100 manufactured by Keyence Corporation). Specifically, a cut surface of the waterproof sheet for residential foundations was observed with the digital microscope at a magnification of 100 to 300 times under no load, and the fluff thickness of the front nonwoven fabric layer and the back nonwoven fabric layer on the cut surface was calculated as the average value (average length) of the fluff length from the surface (baseline) of each nonwoven fabric layer.

[0052] [Flowing water retention rate] Ten 10 cm x 10 cm test pieces were cut from the waterproof sheet for residential underlayment. The resulting test pieces were weighed, and the average weight (average weight before immersion) of the 10 test pieces was calculated. Next, five test pieces each were immersed in still water and running water conditions in a container at 20-25°C (room temperature) for 10 minutes. The test pieces were secured to the inside of the container with clips to prevent them from floating up during immersion in still water and running water. The running water condition was generated using a stirrer and a 3 cm long tapered rotor, rotating at 1100 rpm. After 10 minutes of immersion, the average weight of the five test pieces immersed in still water (average weight after still water immersion) and the average weight of the five test pieces immersed in running water (average weight after running water immersion) were calculated, and the running water retention rate was calculated using the following formula (1): Running water retention rate = (average weight after immersion in running water - average weight before immersion) / (average weight after immersion in still water - average weight before immersion) × 100 (1) The calculated running water retention rate was evaluated according to the following evaluation criteria. +: Flowing water retention rate is 80% or more (good) -: Flow rate is less than 80% (poor)

[0053] [Nail hole waterproofness] In accordance with the Asphalt Roofing Industry Association standard "Modified Asphalt Roofing Materials 7.8 Nail Hole Sealing," nail hole water sealing performance was measured using staples (Max Staple T3-10MB) with a water head set to 150 mm. MDF plywood (100 mm x 100 mm) was used. Ten test specimens (N=10) were cut from the waterproof sheet for residential underlayment. After 24 hours, the distance of the water (water mark) spreading from the perforation hole was measured for each test specimen. The specimen with the widest water mark (i.e., the greatest distance between the outer edge of the water mark and the perforation hole) among the ten test specimens was evaluated according to the following criteria. Evaluation criteria +: Water mark spread is 20mm or less (good) -: Water mark spread is over 20mm (bad)

[0054] [Transparency] Letters approximately 30 mm in size were written vertically and horizontally on MDF plywood using a 3 mm line width magic marker, and a waterproof sheet for residential basement was placed on top of them.The letters written above were visually inspected from above the waterproof sheet for residential basement (i.e., through the waterproof sheet for residential basement), and the transparency of the waterproof sheet for residential basement was evaluated using the following evaluation criteria. Evaluation criteria +: Characters are visible (good) +-: The text appears blurry (normal) - : Characters are not visible (bad)

[0055] [Adhesion to mortar] Six test pieces measuring 50 mm wide x 200 mm long were cut from the waterproof sheet for residential basement. Mortar was applied to the top nonwoven fabric layer, measuring 50 mm wide x 110 mm long x 15 mm thick. After two weeks of curing at 23°C in an air-curing environment, the test pieces with the mortar applied were subjected to a 90° peel adhesion test in accordance with JIS Z0237 10.4.6 to measure the adhesive strength as an index of adhesion. After measurement, the average adhesive strength of the six test pieces was used as the adhesive strength with the mortar. Sumirin Mortar AC manufactured by Fujikawa Construction Materials Co., Ltd. was used as the mortar material.

[0056] Example 1 A water-absorbent resin (AQUALIC CS, manufactured by Nippon Shokubai Co., Ltd.) and an acrylic resin (XE-3782, manufactured by Tohpe Corporation) were blended in a ratio of water-absorbent resin:acrylic resin = 0.7:1 (mass ratio), dispersed with a sorbitan monooleate-based dispersant, diluted with toluene, and further blended with a crosslinking agent (Takenate D-101E, manufactured by Mitsui Chemicals, Inc., material: acrylic resin), thereby obtaining a water-absorbent resin-containing liquid. The obtained water-absorbent resin-containing liquid was used as a substrate to prepare a 17 g / m2 substrate. 2 The adhesive was applied by transfer using a gravure machine to the back side of the nonwoven fabric (PP / PE core-sheath spunbond nonwoven fabric manufactured by Chori Co., Ltd.), and then dried to obtain a coating density of 7 g / m 2 As the front nonwoven fabric layer, a base material having a basis weight of 18 g / m was used. 2 The surface nonwoven fabric layer had a basis weight of 17 g / m2 (PP / PE core-sheath air-through nonwoven fabric, manufactured by Chori Co., Ltd.). 2 The cloth sheet (HN55, manufactured by Sumika Sekisui Film Co., Ltd., material: PE), the film (LL sheet, manufactured by Sakai Chemical Industry Co., Ltd., material: PE, thickness: 0.05 mm), and the backside nonwoven fabric layer obtained above were stacked in this order and laminated to obtain a waterproof sheet for residential foundations of Example 1. The obtained waterproof sheet for residential foundations was subjected to various measurements and evaluations using the methods described above. The results are shown in Table 1.

[0057] <Example 2> Base material weight 25g / m 2 The water-absorbent resin-containing liquid obtained in the same manner as in Example 1 was applied to the back side of the back-side nonwoven fabric (Maeda Kosen Co., Ltd., spunbond nonwoven fabric, SP-1025E-WH, material: PP) by transfer using a gravure machine, and then dried to obtain a water-absorbent resin-containing liquid of 10 g / m 2 As the front nonwoven fabric layer, a base material having a basis weight of 28 g / m was used. 2 The surface nonwoven fabric layer had a basis weight of 17 g / m2 (PP / PE core-sheath air-through nonwoven fabric, manufactured by Chori Co., Ltd.). 2 A cross sheet (HN55, manufactured by Sumika Sekisui Film Co., Ltd., material: PE), a film (LL sheet, manufactured by Sakai Chemical Industry Co., Ltd., material: PE, thickness: 0.05 mm), and the backside nonwoven fabric layer obtained above were layered together and laminated to obtain a waterproof sheet for residential foundations of Example 2. The obtained waterproof sheet for residential foundations was subjected to various measurements and evaluations using the methods described above. The results are shown in Table 1.

[0058] Example 3 Base material weight 15g / m 2 The water-absorbent resin-containing liquid obtained in the same manner as in Example 1 was applied to the back side of the back-side nonwoven fabric (Maeda Kosen Co., Ltd., spunbond nonwoven fabric, SP-1015E, material: PP) by transfer using a gravure machine, and then dried to obtain a water-absorbent resin-containing liquid of 7 g / m 2 As the front nonwoven fabric layer, a base material having a basis weight of 15 g / m was used. 2 The surface nonwoven fabric layer had a basis weight of 17 g / m2 (PP / PE core-sheath air-through nonwoven fabric, manufactured by Chori Co., Ltd.). 2 The cloth sheet (HN55, manufactured by Sumika Sekisui Film Co., Ltd., material: PE), the film (LL sheet, manufactured by Sakai Chemical Industry Co., Ltd., material: PE, thickness: 0.05 mm), and the backside nonwoven fabric layer obtained above were stacked in this order and laminated to obtain a waterproof sheet for residential foundations of Example 3. The obtained waterproof sheet for residential foundations was subjected to various measurements and evaluations using the methods described above. The results are shown in Table 1.

[0059] Example 4 A backside nonwoven fabric layer (containing a water-absorbent resin) was obtained in the same manner as in Example 2. As the frontside nonwoven fabric layer, a base material having a basis weight of 13 g / m 2 The surface nonwoven fabric layer had a basis weight of 17 g / m2 (PP / PE core-sheath air-through nonwoven fabric, manufactured by Chori Co., Ltd.). 2 The cloth sheet (HN55, manufactured by Sumika Sekisui Film Co., Ltd., material: PE), the film (LL sheet, manufactured by Sakai Chemical Industry Co., Ltd., material: PE, thickness: 0.05 mm), and the backside nonwoven fabric layer obtained above were stacked in this order and laminated to obtain a waterproof sheet for residential foundations of Example 4. The obtained waterproof sheet for residential foundations was subjected to various measurements and evaluations using the methods described above. The results are shown in Table 1.

[0060] <Comparative Example 1> Base material weight 18g / m 2 The water-absorbent resin-containing liquid obtained in the same manner as in Example 1 was applied by transfer using a gravure machine to the surface of the front nonwoven fabric (PP / PE core-sheath air-through nonwoven fabric manufactured by Chori Co., Ltd.), and then dried to obtain a water-absorbent resin-containing liquid of 7 g / m 2 As a backside nonwoven fabric layer, a base material having a basis weight of 17 g / m was used. 2 The surface nonwoven fabric layer obtained above contained only the backside nonwoven fabric (PP / PE core-sheath spunbond nonwoven fabric manufactured by Chori Co., Ltd.). 2 A cross sheet (HN55, manufactured by Sumika Sekisui Film Co., Ltd., material: PE), a film (LL sheet, manufactured by Sakai Chemical Industry Co., Ltd., material: PE, thickness: 0.05 mm), and the backside nonwoven fabric layer were layered together in this order and laminated to obtain a waterproof sheet for residential foundations of Comparative Example 1. In the waterproof sheet for residential foundations of Comparative Example 1, the frontside nonwoven fabric layer contains a water-absorbent resin, while the backside nonwoven fabric layer does not contain a water-absorbent resin. The obtained waterproof sheet for residential foundations was subjected to various measurements and evaluations using the methods described above. The results are shown in Table 2.

[0061] <Comparative Example 2> The surface nonwoven fabric layer is made of a base material with a basis weight of 18 g / m 2 The backside nonwoven fabric layer contained only the surface nonwoven fabric (PP / PE core-sheath air-through nonwoven fabric manufactured by Chori Co., Ltd.). 2 The surface nonwoven fabric layer had a basis weight of 17 g / m. 2 A cross sheet (HN55, material: PE, manufactured by Sumika Sekisui Film Co., Ltd.), a film (LL sheet, material: PE, thickness: 0.05 mm, manufactured by Sakai Chemical Industry Co., Ltd.), and the backside nonwoven fabric layer were layered together in this order and laminated to obtain a waterproof sheet for residential foundations of Comparative Example 2. Note that in the waterproof sheet for residential foundations of Comparative Example 2, neither the front side nonwoven fabric layer nor the back side nonwoven fabric layer contained a water-absorbent resin. The obtained waterproof sheet for residential foundations was subjected to various measurements and evaluations using the methods described above. The results are shown in Table 2.

[0062] [Table 1]

[0063] [Table 2]

[0064] As shown in Table 1, the waterproof sheets for residential underlayment of Examples 1 to 4, which were laminated with a front nonwoven fabric layer, a cross sheet, a film, and a back nonwoven fabric layer, and in which the back nonwoven fabric layer contained a water-absorbent resin, had excellent water retention and nail hole waterproofing properties, and even when a through hole was formed by a nail or the like, they had excellent performance in preventing water penetration through the through hole.

[0065] The waterproof sheets for residential foundations of Examples 1, 3, and 4 had particularly improved transparency because the basis weight of at least one of the front nonwoven fabric layer and the back nonwoven fabric layer was small.

[0066] The waterproof sheets for residential foundations of Examples 1 and 2, in which the basis weight of the front nonwoven fabric layer is greater than the basis weight of the back nonwoven fabric layer, had improved adhesion to mortar compared to the waterproof sheet for residential foundations of Example 3, in which the basis weight of the front nonwoven fabric layer is equal to the basis weight of the back nonwoven fabric layer, and the waterproof sheet for residential foundations of Example 4, in which the basis weight of the front nonwoven fabric layer is smaller than the basis weight of the back nonwoven fabric layer.

[0067] On the other hand, the waterproof sheet for residential foundations of Comparative Example 1, in which the front nonwoven fabric layer contained a water-absorbent resin and the back nonwoven fabric layer did not, was inferior in running water retention rate and nail hole waterproofing performance, as shown in Table 2. The reason for this is presumably that the front nonwoven fabric layer containing an air-through nonwoven fabric has greater fuzz than the back nonwoven fabric layer containing a spunbond nonwoven fabric, making it difficult for the water-absorbent resin to firmly adhere to the front nonwoven fabric contained in the front nonwoven fabric layer, and therefore the water-absorbent resin was more likely to detach from the front nonwoven fabric layer.

[0068] The waterproof sheet for residential foundations of Comparative Example 2, in which neither the front nor back nonwoven fabric layer contained a water-absorbent resin, had poor nail hole waterproofing properties because there was nothing to plug through holes formed by nails, etc. Furthermore, because there was nothing to plug through holes, it was not possible to measure the water retention rate in the first place, and therefore it was not possible to evaluate it. [Industrial Applicability]

[0069] The waterproof sheet for residential foundations of the present invention can be suitably used, for example, as a waterproof sheet to cover the foundation when building a house. [Explanation of symbols]

[0070] 1. Waterproofing sheet for residential base 2 Front nonwoven fabric layer 3 cross seats 4 Film 5 Back nonwoven layer d1, d2 fluff thickness

Claims

1. At least a front nonwoven fabric layer, a cloth sheet, a film, and a back nonwoven fabric layer are laminated together, A waterproof sheet for housing foundations, wherein the backside nonwoven fabric layer contains a water-absorbent resin, A test piece measuring 50 mm wide x 200 mm long was cut out from the waterproof sheet for residential basement. Mortar was applied to the surface of the front nonwoven fabric layer to a width of 50 mm, a length of 110 mm, and a thickness of 15 mm. The test piece was then cured in an air-curing environment at 23°C for two weeks, and the 90° peel adhesive strength of the test piece to the mortar measured in accordance with JIS Z0237 10.4.6 was found to be 2.4 to 8.7 N / 25 mm.

2. the front nonwoven fabric layer and the back nonwoven fabric layer each contain a nonwoven fabric made of a polyolefin resin as a base material, The waterproof sheet for residential foundations according to claim 1, wherein the fluff thickness of the front nonwoven fabric layer is greater than the fluff thickness of the back nonwoven fabric layer.

3. 3. The waterproof sheet for residential foundations according to claim 2, wherein the nonwoven fabric made from polyolefin resin contained in the front nonwoven fabric layer is an air-through nonwoven fabric.

4. 3. The waterproof sheet for residential foundations according to claim 2, wherein the nonwoven fabric made from a polyolefin resin contained in the back nonwoven fabric layer is a spunbond nonwoven fabric.

5. The surface nonwoven fabric layer and the back nonwoven fabric layer each have a basis weight of 15 to 28 g / m ２ The waterproof sheet for housing foundation according to any one of claims 1 to 4, wherein

6. The content of the water-absorbent resin in the back nonwoven fabric layer is 5 to 10 g / m ２ The waterproof sheet for housing foundation according to any one of claims 1 to 5,

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