Waterproof sheet with fewer wrinkles, and waterproofing method

Abstract

To provide a waterproof sheet capable of reducing wrinkles that occur during waterproof sheet installation, a waterproof structure, and a waterproofing method.SOLUTION: The waterproof sheet with fewer wrinkles is a waterproof sheet that includes a vinyl chloride resin layer and a constraining layer that contains a thermoplastic resin or a thermoplastic elastomer. The constraining layer is placed on the outermost layer of the waterproof sheet. The thickness of the restraining layer is 2.0% to 20% of the total thickness of the waterproof sheet, and the interlayer peel strength between the constraining layer and the vinyl chloride resin layer is 0.3 N / mm or more. A waterproofing method using the same is also provided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a waterproof sheet and construction method that can reduce wrinkles in waterproof sheets during construction on rooftops, roofs, verandas, etc. [Background technology]

[0002] There are two main construction methods for sheet waterproofing: adhesive and mechanical fixing. The adhesive method involves applying adhesive to the back of the substrate or waterproof sheet, and then attaching the waterproof sheet to the substrate. On the other hand, the mechanical fixing method involves partially fixing the waterproof sheet to the substrate using fasteners such as discs and screws.

[0003] With the adhesive method, the entire waterproofing sheet is adhered to the base during installation, which means that wrinkles are less likely to occur. On the other hand, with the mechanical fixing method, the waterproofing sheet is partially fixed to the base, so when fixing the waterproofing sheet laid on the base, it must be stretched out to avoid wrinkles, and unless the worker has the necessary skills, there is a problem that the waterproofing sheet will be installed with wrinkles. Areas welded with disks or solvents are difficult to repair, requiring careful and meticulous work, which can reduce work efficiency and ultimately increase the number of days required for installation.

[0004] Patent Documents 1 and 2 describe inventions that use temporary fixing devices and members to prevent wrinkles from forming during construction.

[0005] However, using a temporary fixing device or member increases the number of temporary fixing steps and the step of releasing the temporary fixing step, making the construction process more complicated. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Utility Model Application Publication No. 5-57162 [Patent Document 2] Patent Publication No. 2021-38556 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to provide a waterproof sheet, a waterproof structure, and a waterproof construction method that reduce wrinkles that occur when the waterproof sheet is installed. [Means for solving the problem]

[0008] The present invention is a wrinkle-reducing waterproof sheet having a vinyl chloride resin layer and a constraining layer containing a thermoplastic resin or a thermoplastic elastomer, wherein the constraining layer is arranged as the outermost layer of the waterproof sheet, the thickness of the constraining layer is 2.0% to 20% of the total thickness of the waterproof sheet, and the peel strength between the constraining layer and the vinyl chloride resin layer is 0.3 N / mm or more.

[0009] Furthermore, it is desirable that the wrinkle-reducing waterproof sheet have a 100% modulus of 6.0 MPa or more.

[0010] The waterproof structure is also such that the wrinkle-reducing waterproof sheet is partially fixed to the substrate.

[0011] The waterproofing method also includes the steps of fixing a fixed plate placed on a base with a fastener for the fixed plate, spreading the wrinkle-reducing waterproof sheet over the base and the fixed plate, and fixing the wrinkle-reducing waterproof sheet to the fixed plate.

[0012] This waterproofing method includes the steps of: unfolding the wrinkle-reducing waterproof sheet on a base; placing a fixing plate on the wrinkle-reducing waterproof sheet; fixing the fixing plate to the base with fixing plate fasteners; and covering the fixing plate and the fixing plate fasteners with an additional sheet to make them waterproof. [Effects of the Invention]

[0013] According to the present invention, it is possible to reduce wrinkles that occur when installing a waterproof sheet. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view showing one embodiment of the wrinkle-reduced waterproof sheet of the present invention. [Figure 2] 1 is a partial cross-sectional view showing one embodiment of a sheet waterproofing structure using the wrinkle-reduced waterproof sheet of the present invention. [Figure 3] FIG. 10 is a partial cross-sectional view showing another embodiment of a sheet waterproofing structure using the wrinkle-reduced waterproof sheet of the present invention. [Figure 4] 1 is a graph showing the relationship between the interlayer peel strength between the vinyl chloride resin layer and the constraining layer of a wrinkle-reducing waterproof sheet and the peel state when bent 90 degrees. DETAILED DESCRIPTION OF THE INVENTION

[0015] Preferred embodiments of the present invention will now be described in detail.

[0016] The wrinkle-reduced waterproof sheet of the present invention will be described with reference to Fig. 1. The wrinkle-reduced waterproof sheet is a waterproof sheet having at least a vinyl chloride resin layer and a constraining layer containing a thermoplastic resin or a thermoplastic elastomer, with the constraining layer being the outermost layer. Fig. 1 shows a wrinkle-reduced waterproof sheet consisting of a constraining layer (1), vinyl chloride resin layers (2), (2'), and a substrate (3). The substrate (3) is provided to reinforce the waterproof sheet and is laminated on the vinyl chloride resin layer. As shown in Figure 1, it may be provided in the middle of the vinyl chloride resin layer (between the vinyl chloride resin layer (2) and the vinyl chloride resin layer (2')), or it may be provided as the bottom layer. Nonwoven or woven fabric made of polyester fiber or glass fiber can be used as the substrate (3). It is not necessary to have only the constraining layer (1) and the vinyl chloride resin layer (2) laminated together, and there may be no substrate. The vinyl chloride resin layer may be one layer or multiple layers, and in the case of multiple layers, the compositions of the individual layers may be different.

[0017] The constraining layer can be made of a thermoplastic resin or a thermoplastic elastomer. Examples of suitable thermoplastic resins include vinyl chloride resins such as vinyl chloride resins and vinyl chloride copolymers, and acrylic resins such as olefin resins, acrylic resins, and acrylic copolymers. In addition to the elastomer and resin components, the constraining layer can also contain various additives, such as fillers, plasticizers, heat stabilizers, pigments, flame retardants, lubricants, processing aids, light stabilizers, antioxidants, antistatic agents, and ultraviolet absorbers. The constraining layer may be a single layer or multiple layers. For example, a base material such as a nonwoven or woven fabric made of polyester fiber or glass fiber may be laminated onto a resin layer or a thermoplastic elastomer layer, or multiple layers made of different thermoplastic resins or thermoplastic elastomers may be laminated.

[0018] The constraining layer of the present invention preferably has higher elasticity than the vinyl chloride resin layer and also has flexibility and extensibility. For example, the elongation of the constraining layer measured and calculated according to JIS A 6008 (tensile speed: 200 mm / min) is preferably 20% to 300%, more preferably 20% to 200%. The constraining layer preferably has a smaller elongation than the vinyl chloride resin layer.

[0019] The vinyl chloride resin layer can use, as a resin component, a vinyl chloride resin such as a vinyl chloride resin or a vinyl chloride copolymer, etc. The vinyl chloride resin layer can also contain various additives, such as fillers, plasticizers, heat stabilizers, pigments, flame retardants, lubricants, processing aids, light stabilizers, antioxidants, antistatic agents, and ultraviolet absorbers.

[0020] It is known that plasticizers are generally added to vinyl chloride resin waterproof sheets to give them flexibility. Typically, vinyl chloride resin waterproof sheets contain 40 or more parts by weight of plasticizer per 100 parts by weight of vinyl chloride resin, and it is desirable for the vinyl chloride resin layer of wrinkle-reducing waterproof sheets to contain a similar amount of plasticizer.

[0021] Normally, waterproof sheets are manufactured in a factory, then rolled up on a cardboard tube and shipped in roll form. The rolled waterproof sheet is then brought to the construction site and placed where it is desired to be laid on the substrate, and rolled out. Because waterproof sheets are flexible, they can become twisted and wrinkled when moved for fine adjustments after being unrolled, making it difficult to lay the waterproof sheet with a smooth surface. Therefore, when securing the sheet to the substrate, it is stretched as it is laid and secured. Therefore, in the present invention, by laminating a constraining layer that has higher elasticity than the vinyl chloride resin layer and has a certain degree of flexibility and extensibility as the outermost layer on top of the vinyl chloride resin layer that functions as a waterproof sheet, it has been discovered that when the waterproof sheet is spread out on a substrate, it is less likely to wrinkle on the surface and can be laid with a smooth surface.

[0022] The wrinkle-reduced waterproof sheet of the present invention is a sheet body in which a vinyl chloride resin layer and a constraining layer are previously bonded or joined together to form an integrated sheet. The previously integrated vinyl chloride resin layer and constraining layer achieve the above-mentioned effects. The vinyl chloride resin layer and the constraining layer may be bonded and integrated via a primer or adhesive, but considering durability against sunlight, rain, wind pressure, etc., for long-term outdoor use, it is preferable to bond them together without using an adhesive. Specifically, the vinyl chloride resin layer and the thermoplastic resin layer or thermoplastic elastomer layer that serves as the constraining layer can be directly thermally laminated to form the integrated sheet.

[0023] To provide the waterproof sheet with the aforementioned elasticity—in other words, flexibility and extensibility within a certain range—the constraining layer and the vinyl chloride resin layer must be bonded or joined together, and the interlayer peel strength must be sufficient to allow the physical properties of each layer to affect each other in the face of external forces. If the peel strength between the constraining layer and the vinyl chloride resin layer is not sufficient, the properties described above will not be achieved and will depend on the physical properties of each layer. Therefore, the interlayer peel strength described in the following section should be 0.3 N / mm or higher, and preferably 0.4 N / mm or higher.

[0024] A total of 76 waterproof sheet samples were produced, consisting of multiple integrated sheets with different interlayer bond strengths, by varying the temperature conditions for thermal lamination when laminating the vinyl chloride resin layer and the constraining layer. Test pieces measuring 25 mm wide x 150 mm long were taken from each sample. The interlayer peel strength of each test piece was measured using the following method, and Figure 4 shows the relationship between the peel strength between the vinyl chloride resin layer and the constraining layer when the test piece was bent 90 degrees. In this verification, a 2.0 mm thick vinyl chloride resin waterproof sheet was used as the vinyl chloride resin layer, and a constraining layer containing vinyl chloride resin was used.

[0025] [Interlayer peel strength] The bonded surface between the vinyl chloride resin layer and the constraining layer of the test piece was peeled off approximately 20 mm from the edge, and the edge of the vinyl chloride resin layer and the edge of the constraining layer were each clamped in the chucks of a universal testing machine. A T-shaped peel was performed until the chuck gap was 100 mm under conditions of a chuck gap of 20 mm and a tensile speed of 200 mm / min, and the strength was measured at chuck displacements of 25 mm, 40 mm, 55 mm, 70 mm, and 85 mm, and the average value of the five points was taken as the interlayer peel strength. [90 degree bendability] The test piece used to measure the interlayer peel strength was bent 90 degrees at a point 10 mm from the opposite end (the side that did not peel) of the same test piece, and then the test piece was visually checked for peeling between the vinyl chloride resin layer and the restraining layer at the bent point, after bending it once and then bending it again to 90 degrees from the original state, for a total of 10 folds, and judged according to the following classification. [Judgment category] 0 → Peeling occurs when folded 1 time 1 → Does not peel off even when bent once 2 -> No peeling even after 10 folds

[0026] Figure 4 shows a scatter plot of the interlayer peel strength and 90-degree bendability of each sample. Figure 4 shows that if the interlayer peel strength is less than 0.3 N / mm, the sample will peel immediately when bent 90 degrees, while if the interlayer peel strength is 0.4 N / mm or greater, the sample will not peel even after being bent 90 degrees 10 times. This shows that a interlayer peel strength of 0.3 N / mm or greater is essential to prevent wrinkles from forming on the surface of the waterproof sheet when it is laid out on a substrate, and to ensure that the waterproof sheet can be laid on a smooth surface without picking up minute irregularities in the substrate. A peel strength of 0.3 N / mm or greater is preferable.

[0027] The wrinkle-reduced waterproof sheet of the present invention is characterized in that, to ensure general waterproof performance, the vinyl chloride resin layer must have performance conforming to JIS A 6008, and the thickness of the aforementioned constraining layer is 2.0% to 20% of the total thickness of the wrinkle-reduced waterproof sheet of the present invention, i.e., the waterproof sheet having a vinyl chloride resin layer and a constraining layer containing a thermoplastic resin or a thermoplastic elastomer. Furthermore, with regard to the thickness of each layer, the vinyl chloride resin layer is preferably about 1.0 mm to 2.5 mm, and the constraining layer is preferably about 0.05 mm to 0.30 mm.

[0028] The wrinkle-reduced waterproof sheet of the present invention preferably has a 100% modulus of 6.0 MPa or more. Specifically, a test piece 19 mm wide x 120 mm long is sampled so that the machine direction (MD), the flow direction during sheet formation, is the longitudinal direction. A tensile test is conducted at a chuck distance of 50 mm and a tensile speed of 50 mm / min. In the resulting stress-displacement curve (SS curve), the tensile stress at 100% of the initial length is preferably 6.0 MPa or more. This waterproof sheet is less likely to wrinkle when unfolded on a substrate, allowing it to be laid with a smooth surface without picking up minor irregularities in the substrate.

[0029] The constraining layer is placed on the outermost layer of the wrinkle-reducing waterproof sheet, and in addition to the above, can be made to have functions such as flame retardancy, transparency, heat insulation, radiative cooling function, and antiviral property. For example, by using an acrylic resin such as an acrylic resin or an acrylic copolymer, which is a thermoplastic resin that is transparent and has excellent weather resistance, it is possible to suppress light deterioration of the vinyl chloride resin layer that is placed below the constraining layer, and when a pattern design is applied to the vinyl chloride resin layer by transfer or printing, it can serve as a protective layer for the pattern design.

[0030] To impart flame retardancy, known flame retardants such as inorganic, bromine-based, phosphorus-based, and chlorine-based flame retardants can be used in the constraining layer. Some of these are listed below, but the following flame retardants are not limited to these. The following flame retardants can also be used in the vinyl chloride resin layer. Inorganic flame retardants include antimony trioxide, antimony pentoxide, molybdenum trioxide, zinc stannate, aluminum hydroxide, magnesium hydroxide, zinc borate, and lithium oxide. Bromine-based flame retardants include decabromodiphenyl oxide, tribromophenyl allyl ether, ethylene bistetrabromophthalimide, brominated polystyrene, hexabromocyclododecane, and ethylene bispentabromodiphenyl. Phosphorus-based flame retardants include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, triallyl phosphate, trischloroethyl phosphate, and trisdichlorophosphate. Chlorine-based flame retardants include chlorinated paraffin and chlorinated polyethylene.

[0031] In addition, in order to prevent the spread of fire to the waterproof sheet due to sparks flying from an external fire, a flame retardant that generates a non-flammable gas at high temperatures upon ignition is desirable, and examples include antimony trioxide, antimony pentoxide, aluminum hydroxide, magnesium hydroxide, decabromodiphenyl oxide, tribromophenyl allyl ether, ethylene bistetrabromophthalimide, brominated polystyrene, hexabromocyclododecane, ethylene bispentabromodiphenyl, chlorinated paraffin, and chlorinated polyethylene.

[0032] Furthermore, when waterproof sheets are heat-welded together during installation, in order to prevent the waterproof sheets from foaming, it is desirable to use a non-hydrous inorganic oxide as the flame retardant, such as antimony trioxide, antimony pentoxide, molybdenum trioxide, or lithium oxide.

[0033] Furthermore, inorganic flame retardants are preferable when taking into consideration stickiness and staining caused by bleeding of the flame retardant onto the surface of the waterproof sheet, as well as weldability during joining. Adding a large amount of inorganic flame retardant reduces weldability, so it is best to add up to 100 parts by weight of the flame retardant to 100 parts by weight of thermoplastic resin or thermoplastic elastomer so that the oxygen index is 25 or higher.

[0034] When a constraining layer containing a thermoplastic resin or a thermoplastic elastomer has a heat-shielding function, examples include a type in which a pigment is kneaded into the thermoplastic resin or the thermoplastic elastomer, a multi-layer type in which a heat-shielding layer containing a substance with high solar reflectance is laminated, and a multi-layer type in which multiple layers with different optical properties are laminated alternately (such as a nano-laminate film or a film laminated with layers with a negative refractive index). When a pigment is kneaded in, the pigments listed below are available. With the exception of carbon pigments, pigments that can be used for coloring include phthalocyanine, isoindolinone, perylene, azo, condensed azo, quinacridone, anthraquinone, aniline black, triphenylmethane, dioxazine, titanium oxide, iron oxide, chromium oxide, lead chromate, and calcined spinel pigments. From these pigments, pigments with particularly high infrared reflectance in the 780 nm to 2500 nm wavelength range are arbitrarily blended to provide color.

[0035] Multilayered heat-shielding sheets, which incorporate a heat-shielding layer containing a material with high solar reflectance, include sheet-like products using metal films such as aluminum foil or metal-deposited films, in which metal particles are vapor-deposited on a film-like substrate such as PET (polyethylene terephthalate), as the heat-shielding layer. They also include films containing infrared-absorbing materials such as ITO (tin-doped indium oxide) and ATO (antimony-doped tin oxide). One indicator of heat-shielding performance is the solar reflectance in the 780-2500 nm range. The solar reflectance of a heat-shielding sheet in the 780-2500 nm range is measured using the test method specified in JIS K 5602, "Determination of the Solar Reflectance of Coating Films." The coating film in this standard is then converted into a heat-shielding sheet, and a black opacity test paper is placed against the back of the heat-shielding sheet as a test piece. This 780-2500 nm range, defined as the near-infrared region, has been reported to have a particularly strong effect on temperature rise. The solar reflectance of the heat-shielding constraining layer in the wavelength range of 780 nm to 2500 nm is preferably 30% or more, and more preferably 60% or more. The heat-shielding constraining layers using the above-mentioned metal films or metal-deposited films often have a relatively high solar reflectance, and are therefore preferred.

[0036] The wrinkle-reduced waterproof sheet of the present invention is a long waterproof sheet manufactured by a method such as a calendaring method, an extrusion method, or a sol-drawing method. In these manufacturing methods, in the configuration shown in Figure 1, a vinyl chloride resin layer (2) is formed into a sheet and then laminated onto a substrate (3), or the substrate (3) is sol-drawn and then laminated with a vinyl chloride resin layer (2). In these molding methods, the vinyl chloride resin layer (2) is generally laminated while the substrate (3) is stretched in the longitudinal direction (machine direction, MD) while the material is heated. This applies longitudinal tension to the substrate (3), leaving residual strain in the substrate (3). Residual strain also remains in the vinyl chloride resin layer (2). Residual strain also remains in the wrinkle-reduced waterproof sheet (C) obtained by subsequently laminating a constraining layer (1) and a vinyl chloride resin layer (2'), which is composed of the constraining layer (1), the vinyl chloride resin layers (2) and (2'), and the substrate (3). Here, the inventors of the present invention have discovered a sheet that can reduce residual distortion in the waterproof sheet, unevenness during installation, or wrinkles that occur during installation by laminating a restraining layer having the aforementioned certain physical properties to a vinyl chloride resin layer.

[0037] A waterproof structure and a waterproofing method using the wrinkle-reduced waterproof sheet of the present invention will now be described. The wrinkle-reduced waterproof sheet of the present invention is a waterproof sheet used for waterproofing the rooftops of buildings, and is particularly a waterproof sheet installed using a mechanical fixing method. As shown in Figures 2 and 3, a waterproof structure using the wrinkle-reduced waterproof sheet of the present invention has a wrinkle-reduced waterproof sheet (C) partially fixed to a substrate (H) such as a rooftop by a fixing plate (F) and a fastener (G) for the fixing plate. The wrinkle-reduced waterproof sheet (C) is arranged so that the constraining layer (1), which is the outermost layer, is on the upper side (opposite the substrate (H)).

[0038] The type of substrate is not particularly limited, and may be a concrete substrate such as reinforced concrete (RC), precast concrete (PC), or lightweight foam concrete (ALC), a metal substrate, or a wooden substrate, or an inorganic board such as a cement board, slate board, or calcium silicate board placed on top of any of these. The inorganic board may also be placed between the heat insulating layer and the waterproof layer.

[0039] The waterproofing method using the wrinkle-reduced waterproof sheet of the present invention is also suitable for renovating existing waterproof structures. When renovating an existing waterproof structure, a new waterproof structure can be installed on the base after removing the existing waterproof layer and insulation layer, but renovation is also possible without removing the existing waterproof structure. In a thermally insulated waterproof structure using the wrinkle-reduced waterproof sheet of the present invention, for example, a new wrinkle-reduced waterproof sheet that serves as both an insulation layer and a waterproof layer can be installed on top of the existing waterproof structure, or the wrinkle-reduced waterproof sheet alone can serve as a waterproof layer. For example, if the constraint layer of the wrinkle-reduced waterproof sheet has a heat-shielding function, installing the wrinkle-reduced waterproof sheet on top of the existing thermally insulated waterproof structure can suppress the progression of thermal degradation of the existing insulation material, and it is also possible to utilize the existing thermal insulation structure to create a new thermally insulated waterproof structure.

[0040] The mechanical fixing method is a method of fixing the waterproofing sheet to the substrate using fixing plates and fixing plate fasteners. The work of attaching fixing plates to the substrate at specified intervals is less labor-intensive than applying adhesive to the entire surface, and construction time can be shortened. In addition, since construction can be done even when the substrate is wet, there is the advantage that the construction period is less affected by weather.

[0041] The waterproofing method for the waterproof structure shown in Figure 2 will now be described. This waterproofing method includes the steps of fixing a fixed plate (F) placed on a base (H) with a fastener (G) for the fixed plate, spreading a wrinkle-reducing waterproof sheet (C) over the base (H) and the fixed plate (F), and fixing the wrinkle-reducing waterproof sheet (C) to the fixed plate (F).

[0042] In Figure 2, the fixing plate (F) is a disk-shaped steel plate with a vinyl chloride resin film laminated to its surface. The fixing plate (F) is placed on the base (H) and secured to the base (H) with fixing plate fasteners (G). Multiple fixing plates (not shown) are then similarly secured to the base (H) at regular intervals. Once all fixing plates (F) are secured to the base (H), a roll of wrinkle-reducing waterproof sheet (C) is placed on top of the base and rolled to unfold the sheet so that the restraining layer is on top. When using multiple rolls of wrinkle-reducing waterproof sheet (C), the edges of adjacent sheets are laid out so that they overlap by approximately 40 mm. The disk-shaped fixing plate (F) is then heated while being pressed against the wrinkle-reducing waterproof sheet (C) using an induction heating device. Heating the disk melts the vinyl chloride resin film on the surface of the steel plate and presses it against the vinyl chloride resin layer of the wrinkle-reducing waterproof sheet (C) that is in contact with the disk. The molten vinyl chloride resin film then cools and solidifies, securing the wrinkle-reducing waterproof sheet (C) to the disk, the fixing plate (F). In addition to induction heating, the wrinkle-reducing waterproof sheet (C) can also be secured to the fixing plate (F) by injecting a solvent that dissolves the vinyl chloride resin with a syringe or other device between the fixing plate (F) and the wrinkle-reducing waterproof sheet (C) and then pressing them together. Once all the fixing plates (F) and the wrinkle-reducing waterproof sheets (C) are secured to each other, the overlapping edges of the wrinkle-reducing waterproof sheets (C), i.e., the vinyl chloride resin layer on the back of one wrinkle-reducing waterproof sheet (C) and the constraining layer on the top layer of another wrinkle-reducing waterproof sheet (C), are welded by applying solvent to their contact surfaces with a brush or other tool and pressing them together.

[0043] The waterproofing method for the waterproof structure shown in Figure 3 will now be described. This waterproofing method includes the steps of: spreading a wrinkle-reducing waterproof sheet (C) on a base (H); placing a fixing plate (F) on the wrinkle-reducing waterproof sheet (C); fixing the fixing plate (F) to the base (H) with fixing plate fasteners (G); and covering the fixing plate (F) and the fixing plate fasteners (G) with an additional sheet (I) to make it waterproof.

[0044] In Figure 3, the fixing plate (F) is a disk-shaped steel plate with a vinyl chloride resin film laminated to its surface. First, a roll of wrinkle-reducing waterproof sheet (C) is placed on the base (H), and the roll is rolled out so that the constraining layer is on top. When using multiple rolls of wrinkle-reducing waterproof sheet (C), the edges of adjacent wrinkle-reducing waterproof sheets (C) are laid so that they overlap by approximately 40 mm. The fixing plate (F) is placed on top of the wrinkle-reducing waterproof sheet (C) laid on the base (H) and secured to the base (H) with the fixing plate fasteners (G). Similarly, multiple fixing plates (not shown) are placed at regular intervals on the wrinkle-reducing waterproof sheet (C) and secured to the base (H). At this time, to prevent the surface of the wrinkle-reducing waterproof sheet (C) from being scratched by the fixing plate (F) where the fixing plate (F) is in close contact with the wrinkle-reducing waterproof sheet (C), it is preferable to interpose a protective sheet (K) between the wrinkle-reducing waterproof sheet (C) and the fixing plate (F). After all the fixing plates (F) and the wrinkle-reducing waterproof sheets (C) have been fixed, the overlapping portions of the ends of the wrinkle-reducing waterproof sheets (C), i.e., the vinyl chloride resin layer that is the back surface of one wrinkle-reducing waterproof sheet (C) and the constraining layer that is the outermost layer of another wrinkle-reducing waterproof sheet (C), are welded by applying a solvent to the contact surfaces with a brush or the like and pressing them together. Furthermore, the fixing plate (F), fixing plate fasteners (G), and the surface of the wrinkle-reducing waterproof sheet (C) around the fixing plate (F) are covered with an additional sheet (I), and the backside of the additional sheet (I) is welded to the fixing plate (F) and the surface of the wrinkle-reducing waterproof sheet (C) around it, and the periphery is sealed with a sealant (J) to make it waterproof. In Figure 3, a vinyl chloride resin sheet is used as the additional sheet (I), and the backside of the additional sheet (I) and the surface of the fixing plate (F) and the restraining layer, which is the outermost layer of the wrinkle-reducing waterproof sheet (C), are welded by applying a solvent to the contact surfaces with a brush or the like and pressing them together. [Example]

[0045] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Test specimens were prepared for the following examples and comparative examples, and the interlayer peel strength between the constraining layer and the vinyl chloride resin layer, the elongation percentage and 100% modulus of the constraining layer were measured, and evaluation tests were carried out during construction. Details of the examples and comparative examples, as well as the measurement and evaluation methods, are as follows.

[0046] [Example 1] A wrinkle-reducing waterproof sheet was created by thermally laminating a 0.05mm thick acrylic resin film constraining layer on top of a 1.5mm thick vinyl chloride resin waterproof sheet with glass cloth laminated in the middle as the base material. [Example 2] A wrinkle-reducing waterproof sheet was created by laminating a constraint layer, which is a sheet with heat-shielding properties consisting of an aluminum vapor-deposited film and a thermoplastic resin layer, on top of a vinyl chloride resin layer, which is a 1.5 mm thick vinyl chloride resin waterproof sheet with glass cloth laminated in the middle as the base material. [Comparative Example 1] This is a 1.5 mm thick vinyl chloride resin waterproof sheet used in Examples 1 and 2. (No restraining layer)

[0047] <Peel strength> A test piece measuring 25 mm wide x 150 mm long was peeled about 20 mm from the end of the bonded surface between the vinyl chloride resin layer and the constraining layer, and the end of the vinyl chloride resin layer and the end of the constraining layer were each clamped in the chucks of a universal testing machine. A T-shaped peel was performed until the chuck gap was 100 mm under conditions of a chuck gap of 20 mm and a tensile speed of 200 mm / min, and the strength was measured at chuck displacements of 25 mm, 40 mm, 55 mm, 70 mm, and 85 mm, and the average value of the five points was taken as the strength of the test piece (no measurement was taken for the comparative example without a constraining layer). The interlaminar peel strength of each test specimen was calculated as the average value of three specimens (n=3) for each test specimen.

[0048] <Elongation rate of the constrained layer> The elongation of the films and sheets used in the constraining layers in Examples 1 and 2 was measured and calculated based on JIS A 6008 (tensile speed: 200 mm / min). Three test pieces were prepared, and the results were averaged for n = 3. (No measurement was performed for the comparative example without a constraining layer.)

[0049] <100% modulus> Test pieces were cut out to a width of 19 mm and a length of 120 mm so that the lengthwise direction was the MD direction. Measurements were performed using a tensile testing machine with a chuck distance of 50 mm and a tensile speed of 50 mm / min to obtain an SS curve. The 100% modulus (MPa) was calculated from the stress (MPa) at 100% displacement relative to the initial length from the obtained SS curve. Three test pieces were prepared, and the results were averaged for n = 3.

[0050] <Evaluation of construction wrinkles> First, draw a straight line to mark the location where the base will be installed. Unfold a rolled sheet measuring 1.2m on the short side and 5m on the long side, align one short side with the mark, and then hold the other short side and shift the sheet so that it is perpendicular to the mark. At this time, adjust the position by gently pulling the sheet. After that, leave the sheet to stand and check the condition of the surface. Here, construction wrinkles refer to wrinkles that occur when the sheet is twisted after the above-mentioned work, and the surface condition is visually checked after the above-mentioned work.

[0051] [Table 1] *The constraining layer broke during the test, and the strength could not be measured at 1.2 N / mm or more.

[0052] From Table 1, it can be seen that Examples 1 and 2, which have a constraint layer, do not wrinkle when the rolled sheet is unfolded and aligned, and are more effective in preventing wrinkles during application than Comparative Example 1, which does not have a constraint layer. [Industrial Applicability]

[0053] According to the present invention, wrinkles caused by the skill level of the installer or unevenness of the base can be reduced in waterproofing construction, and since it is easy to work with, it can be widely used for waterproofing construction of roofs, verandas, etc. of structures. [Explanation of symbols]

[0054] 1 restraint layer 2,2´ vinyl chloride resin layer 3 Base material C. Wrinkle-reducing waterproof sheet F Fixed plate G Fastener for fixed plate H base I Extra sheet J Sealing Material K Protective Sheet

Claims

1. A waterproof sheet having a vinyl chloride resin layer and a constraining layer containing a thermoplastic resin or a thermoplastic elastomer, The constraining layer is disposed on the outermost layer of the waterproof sheet, The thickness of the constraint layer is 2.0% to 20% of the total thickness of the waterproof sheet, A wrinkle-reduced waterproof sheet characterized in that the interlayer peel strength between the constraining layer and the vinyl chloride resin layer is 0.3 N / mm or more.

2. 2. The wrinkle-reduced waterproof sheet according to claim 1, wherein the 100% modulus is 6.0 MPa or more.

3. A waterproof structure in which the wrinkle-reducing waterproof sheet according to claim 1 or 2 is partially fixed to a substrate.

4. a step of fixing the fixing plate placed on the base with a fixing plate fastener; A step of spreading the wrinkle-reducing waterproof sheet according to claim 1 or 2 over the base and the fixing plate; and a step of fixing the wrinkle-reducing waterproof sheet to the fixing plate.

5. A step of spreading the wrinkle-reduced waterproof sheet according to claim 1 or 2 on a substrate; placing a fixing plate on the wrinkle-reducing waterproof sheet; a step of fixing the fixing plate to a base using a fixing plate fastener; and covering the fixing plate and the fasteners for the fixing plate with an additional sheet to make the waterproofing.

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