JP7768482B2 - Waterproofing sheets and sheet waterproofing structures - Google Patents

Description

The present invention relates to a waterproof sheet used to waterproof a building structure, and a sheet-type waterproof structure equipped with such a waterproof sheet.

In recent years, proposals have been made to use sheet waterproofing structures in which waterproof sheets (resin sheets) are laid down when renovating water tanks attached to swimming pools.

In this sheet waterproofing structure, for example, at least a portion of the floor and wall sections that make up the water tank (structure) are covered (laid) with a waterproof sheet.

The waterproof sheet is fixed to the water tank (body), for example, by fixing multiple fixed devices (steel plates) of a specified shape to the water tank (floor or wall) using fixing jigs such as fixing screws, and then joining the upper surfaces of these fixing devices to the underside of the waterproof sheet, thereby joining the water tank and the waterproof sheet via the fixing devices. This re-waterproofs the water tank and ensures that the waterproof sheet is fixed to the water tank without shifting when water is stored in it or when swimmers swim in it.

In a water tank renovated with a sheet waterproofing structure of this configuration, the floor may be equipped with course lines to show swimmers their course, as well as a 5m line and a center line to show swimmers their swimming position, and the walls may be equipped with water level indicators to show the pool's depth. In this case, for example, a colored waterproofing sheet, such as that described in Patent Document 1, may be attached to the waterproofing sheet that makes up the sheet waterproofing structure.

However, as mentioned above, when the sheet waterproofing structure includes a colored waterproof sheet (waterproof sheet), that is, when an indicator is formed on a renovated water tank by attaching a colored waterproof sheet to a waterproof sheet, there is a problem that, particularly with colored waterproof sheets that are colored black, swelling occurs on the surface over time, marring the appearance of the indicator and even causing peeling between the indicator, i.e., the colored waterproof sheet, and the waterproof sheet.

Therefore, there is a need for a black-colored waterproof sheet that, even when used as an indicator in sheet waterproofing structures, prevents the occurrence of swelling on the surface over time.

It is believed that this same problem would also occur if the waterproof sheeting laid on the floor and walls of a water tank (body) was colored black for the purpose of adding design.

WO2010/116497

The object of the present invention is to provide a waterproof sheet that effectively suppresses or prevents the occurrence of swelling on the surface of a waterproof sheet over time, even if the waterproof sheet used is colored black, in a sheet-based waterproof structure in which waterproofing is achieved by laying the waterproof sheet on a structural body, and a sheet-based waterproof structure in which such a waterproof sheet is laid on a structural body.

These objects can be achieved by the present invention described in (1) to (8) below.
(1) A waterproof sheet used to waterproof a structure and made primarily of resin material,
a first layer located on the side of the frame and a second layer stacked on the side of the first layer opposite to the frame,
the second layer contains a carbon material as a black coloring material,
The waterproof sheet is characterized in that the first layer contains the carbon material , and the content of the carbon material is lower than the content of the carbon material in the second layer.

(2) The structure is waterproofed by a first waterproof sheet covering the structure and a second waterproof sheet laminated on a part of the first waterproof sheet opposite the structure and providing a design to the structure.
The waterproof sheet is the waterproof sheet described in (1) above, which is used as the second waterproof sheet.

(3) The waterproof sheet according to (2) above, wherein the structure of the pool has a floor and walls extending from the floor, and is primarily made of concrete, metal, or fiber-reinforced plastic.

(4) The body is a water tank provided in the pool,
The waterproof sheet according to (3) above, wherein the second waterproof sheet is laminated on the first waterproof sheet as a course line indicating the course that a swimmer will swim.

(5) The waterproof sheet according to any one of (1) to (4) above, further comprising a fiber layer containing a fiber material interposed between the first layer and the second layer.

(6) A waterproof sheet according to any one of (1) to (5) above, wherein the carbon material is carbon black.

(7) A waterproof sheet according to any one of (1) to (6) above, wherein when the content of the carbon material contained in the first layer is A [wt %] and the content of the carbon material contained in the second layer is B [wt %], A/B satisfies the relationship 0.17 ≦A/B≦0.6.

(8) A sheet waterproofing structure comprising the waterproof sheet described in any one of (1) to (7) above and a placement member for fixing the waterproof sheet to the structure.

The waterproof sheet of the present invention has a first layer located on the side facing the body and a second layer laminated on the side of the first layer opposite the body, the second layer containing a carbon material as a black coloring material, and the first layer either not containing the carbon material or containing a lower amount of the carbon material than the second layer.

In sheet-waterproofing structures, where waterproofing is achieved by laying a waterproof sheet on the main body, when a black-colored waterproof sheet is used, applying the waterproof sheet of the present invention configured as described above to this waterproof sheet can effectively suppress or prevent swelling on the surface of the waterproof sheet over time.

FIG. 2 is a partial perspective view showing a portion of the sheet waterproofing structure of the present invention installed on a building frame. 2 is a vertical cross-sectional view taken along line AA showing the case where the second waterproof sheet provided in the sheet waterproof structure shown in FIG. 1 is configured in the first configuration example. FIG. 2 is a vertical cross-sectional view taken along line AA showing the second waterproof sheet provided in the sheet waterproof structure shown in FIG. 1 when configured in the second configuration example. FIG.

The waterproof sheet and sheet waterproof structure of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.

The waterproof sheet 50 of the present invention is used in a sheet waterproofing structure 1 that waterproofs a body 10. It is composed primarily of a resin material and has a first layer 51 located on the body 10 side and a second layer 52 laminated on the side of the first layer 51 opposite the body 10. The second layer 52 contains a carbon material as a black coloring material, and the first layer 51 does not contain the carbon material or the carbon material content is lower than the carbon material content in the second layer 52.

When using a waterproof sheet colored black in a sheet waterproof structure 1 having a floor section 11 and wall sections 12, applying the waterproof sheet 50 of the present invention, which has the above-described configuration, to this waterproof sheet (colored waterproof sheet) effectively suppresses or prevents swelling on the surface of the waterproof sheet 50 over time. Therefore, the sheet waterproof structure 1 equipped with this waterproof sheet 50 can be made highly reliable.

Before describing the waterproof sheet 50 of the present invention, we will now provide a detailed description of this sheet waterproof structure 1 (the sheet waterproof structure of the present invention), i.e., a sheet waterproof structure 1 in which the waterproof sheet 50 of the present invention is applied to a waterproof sheet that has been colored black.

<Waterproof sheet structure>
Figure 1 is a partial perspective view of the sheet waterproofing structure of the present invention installed on a building frame, and Figure 2 is a vertical cross-sectional view along line A-A showing the case where the second waterproofing sheet provided in the sheet waterproofing structure shown in Figure 1 is configured as the first configuration example. In the following explanation, the upper side in Figures 1 and 2 will be referred to as "upper" and the lower side will be referred to as "lower." Also, for the sake of convenience, Figure 1 does not show the entire sheet waterproofing structure, but only partially illustrates the floor and wall portions of the building frame. Also, Figures 1 and 2 exaggerate the thickness of the building frame and waterproofing sheet, which significantly differs from the actual dimensions.

In this embodiment, a sheet waterproofing structure 1 is installed on the body 10 (structural body) serving as the water tank of the pool for renovation purposes, as shown in Figure 1.

The body 10 has a rectangular floor 11 and a rectangular frame-shaped wall 12 (rising portion) that stands along the outer edge of the floor 11 and surrounds it.

By configuring the body 10 with this floor 11 and wall 12, the body 10 has a recess with a bottom in its center, thereby forming a pool water tank in which water is stored (see Figure 1). This body 10, i.e., water tank, is typically constructed primarily from at least one of fiber-reinforced plastic (FRP) or metal such as aluminum or stainless steel, and is fixed in place within a space provided by a concrete frame. However, the need to house the FRP or metal water tank may be omitted, and the concrete frame may directly form the water tank, i.e., body 10.

In this embodiment, the sheet waterproofing structure 1 is constructed by covering the structure 10, i.e., the frame-shaped wall portion 12 and the floor portion 11 that forms the bottom, with a waterproof sheet 30 (first waterproof sheet) and adding design features with a waterproof sheet 50 (second waterproof sheet).The structure includes the waterproof sheet 30 laid in a recess in the structure 10, the waterproof sheet 50 that adds design features by covering part of the waterproof sheet 30, a positioning member 20 and a positioning disk (not shown) as fixing devices for fixing the waterproof sheet 30, and a fixing jig (not shown) that is fixed to the structure 10 and for fixing the positioning member 20 (see Figures 1 and 2).

In the following description, the positioning members 20 are fixed to the recessed corners 13 (boundaries) formed by the floor 11 and wall 12, and further, positioning disks are fixed to the floor 11 and wall 12 at approximately equal intervals in a grid pattern, and the laid waterproof sheet 30 is fixed to the main body 10 via these positioning members 20 and positioning disks.

When placed in the corner 13 between the floor 11 and the wall 12, the positioning member 20 is configured as two joined flat plates with an L-shaped side profile to correspond to the shapes of the floor 11 and the wall 12. When placed in the corner 13, the positioning member 20 is fixed to the main body 10 with a fixing jig (not shown), such as a fixing screw or a fixing disk. The positioning disks (not shown) are disk-shaped overall and are arranged in a grid pattern at approximately equal intervals on the floor 11 and the wall 12. The waterproof sheet 30 (first waterproof sheet) is then laid down together with the positioning member 20 and the positioning disk to cover the recessed portion of the main body 10, i.e., the floor 11 and the wall 12, and is fixed to the main body 10 via the positioning member 20 and the positioning disk. This ensures the waterproofness of the main body 10.

In other words, the waterproof sheet 30 is exposed to water, preventing the main body 10 from being directly exposed to water, thereby ensuring the waterproofing of the main body 10. This makes it possible to store water in the main body 10 (i.e., the water tank) on which the waterproof sheet 30 is laid. Furthermore, the upper surfaces of the positioning member 20 and the positioning disk are joined to the underside of the waterproof sheet 30, and the positioning member 20 and the positioning disk are fixed to the main body 10 via a fixing jig, thereby joining and fixing the waterproof sheet 30 to the main body 10 via the positioning member 20 and the positioning disk. Therefore, displacement of the waterproof sheet 30 from the main body 10 is effectively suppressed or prevented when water is stored in the main body 10 (water tank) or when a swimmer is swimming.

This waterproof sheet 30 (first waterproof sheet) is partially covered with a waterproof sheet 50 (second waterproof sheet) that is colored black, thereby adding design to the sheet waterproof structure 1. In this embodiment, as shown in Figure 1, the waterproof sheet 50 forms a course line that indicates the swimming course for swimmers.

Each part that constitutes this sheet waterproofing structure 1 will be described below.
As mentioned above, the positioning member 20 is positioned near the corner 13 between the floor portion 11 and the wall portion 12 (see Figure 1), and the positioning disks (not shown) are arranged in a grid pattern at approximately equal intervals on the floor portion 11 and the wall portion 12.

Of the positioning member 20 and the positioning disk, in this embodiment, the positioning member 20 is composed of two parts: a first part 21 (bottom) and a second part 22 (raised surface) that have an overall flat plate shape. The second part 22 stands upright from one long side of the first part 21, and its side shape is L-shaped. Furthermore, although not shown in the figure, the positioning disk has an overall disk shape.

As the shapes of the structure 10 to be waterproofed naturally vary, multiple shapes of placement members 20 are prepared in advance, and placement members 20 having first and second portions 21 and 22 that match the shape of the recessed corner 13 of the structure 10 to be actually waterproofed are selected. The placement members 20 are then arranged so that the first and second portions 21 and 22 correspond to the shapes of the floor 11 and wall 12 in the recessed corner 13.

These positioning members 20 and positioning disks are composed of a metal plate and a resin layer that covers the surface of the metal plate. That is, the positioning members 20 and positioning disks have a resin layer on the surface to which the waterproof sheet 30 is attached, and a metal plate on the opposite side. By covering the surface of the metal plate with a resin layer in this way, corrosion of the metal plate can be reliably prevented. Furthermore, they can be reliably joined to the waterproof sheet 30 using welding and heat fusion methods.

The metal plate may be made of, for example, a stainless steel plate, a steel plate such as an iron plate, an aluminum plate, or a copper plate, but a steel plate is preferred. This allows the positioning member 20 and the positioning disk to have excellent strength.

The thickness of the metal plate is not particularly limited, but is preferably between 0.1 mm and 3 mm, and more preferably between 0.3 mm and 2.5 mm.

Examples of resins that make up the resin layer include vinyl chloride resins such as polyvinyl chloride, polyolefin resins, and ethylene-vinyl acetate copolymers. While one or a combination of two or more of these can be used, polyvinyl chloride is preferred. In other words, it is preferable that the resin be the same or identical to the resin that makes up the waterproof sheet 30, which will be described later. This improves adhesion between the resin layer and the waterproof sheet 30. Furthermore, polyvinyl chloride has excellent solvent welding and heat fusion properties, which can more significantly enhance the above-mentioned effects and more reliably prevent corrosion of the positioning member 20 and the positioning disk.

The resin that makes up this resin layer may contain other materials such as plasticizers and stabilizers, which are listed as constituent materials of the waterproof sheet 30 below.

The thickness of the resin layer is not particularly limited, but is preferably 0.1 mm or more, and more preferably 0.3 mm to 0.8 mm. This ensures a strong bond between the waterproof sheet 30 and the resin layer, i.e., between the waterproof sheet 30 and the positioning member 20 and the positioning disk.

Furthermore, as mentioned above, these positioning members 20 and positioning disks are fixed to the main body 10 by fixing jigs (not shown) such as fixing screws and fixing disks.

The positioning member 20 and the positioning disk may be fixed to the main body 10 via a fixing jig. For example, if a fixing screw is used as the fixing jig, the threaded portions of the fixing screw are inserted into holes in the positioning member 20 and the positioning disk, and the threaded portions are then embedded in the main body 10, thereby fixing the positioning member 20 and the positioning disk to the main body 10. Also, if a fixed disk is used as the fixing jig, the positioning member 20 and the positioning disk are fixed to the main body 10 by bonding the positioning member 20 and the positioning disk to the main body 10 via adhesive layers provided on both sides of the fixed disk.

The adhesive layer is primarily composed of at least one type of adhesive, such as an acrylic adhesive, an epoxy adhesive, a silicone adhesive, or a rubber adhesive.

In addition, in this embodiment, the positioning member 20 comprises a first portion 21 and a second portion 22, and has an L-shaped side surface, but is not limited to this configuration. For example, the first portion 21 and the second portion 22 may not be connected to each other, but may be provided as separate bodies, or either the first portion 21 or the second portion 22 may be provided independently.

The waterproof sheet 30 is in sheet (plate) form and covers the floor 11 and wall 12 together with the positioning members 20, positioning disks, and fixing jigs, i.e., covers the main body 10. It is fixed to the main body 10 via the positioning members 20, positioning disks, and fixing jigs by being adhered to the upper surfaces of the positioning members 20 and positioning disks, i.e., the surfaces of the positioning members 20 and positioning disks on the side opposite the fixing jigs where the resin layer is formed.

This exposes the waterproof sheet 30 to water, preventing the main body 10 from being directly exposed to water, thereby ensuring the waterproofing of the main body 10. Therefore, it becomes possible to store water in the main body 10 (i.e., the water tank) on which the waterproof sheet 30 is laid. Furthermore, because the waterproof sheet 30 is fixed to the main body 10 via the positioning member 20, positioning disk, and fixing jig, it is possible to accurately suppress or prevent the waterproof sheet 30 from shifting position from the main body 10 when storing water in the main body 10 (water tank) or when a swimmer is swimming.

Such a waterproof sheet 30 is made of a resin sheet made of a resin composition containing a resin material.

The resin material is not particularly limited, but examples include vinyl chloride resins such as polyvinyl chloride, polyolefin resins, and ethylene-vinyl acetate copolymers, and one or more of these can be used in combination. Of these, vinyl chloride resins are preferred. This allows the waterproof sheet 30 to have excellent solvent welding and heat fusion properties.

Vinyl chloride resins are not particularly limited as long as they are polymers containing vinyl chloride, i.e., oligomers, prepolymers, and polymers. Examples include monomeric polymers of vinyl chloride, copolymers of vinyl chloride with vinyl acetate, ethylene, propylene, etc., and mixtures of two or more of these polymers.

The resin composition may also contain various plasticizers, stabilizers, antioxidants, UV absorbers, processing aids, lubricants, fillers, flame retardants, colorants, etc., and it is particularly preferable for the resin composition to contain plasticizers. This can give the waterproof sheet 30 greater flexibility.

The plasticizer is not particularly limited, but examples include phthalate ester plasticizers such as DOP (dioctyl phthalate), DBP (dibutyl phthalate), DIBP (diisobutyl phthalate), DHP (diheptyl phthalate), and DINP (diisononyl phthalate); aliphatic dibasic acid ester plasticizers such as DOA (di-2-ethylhexyl adipate), DIDA (diisodecyl adipate), and DOS (di-2-ethylhexyl sebacate); aromatic carboxylic acid ester plasticizers such as ethylene glycol benzoates; and trimellitate ester plasticizers such as TOTM (trioctyl trimellitate). These may be used alone or in combination of two or more.

Stabilizers include, for example, zinc glycine, and in this case, stabilizing aids include, for example, organic phosphate esters such as tricresyl phosphate (TCP), trixylyl phosphate (TXP), tributyl phosphate (TBP), tri-2-ethylhexyl phosphate, and 2-ethylhexyl diphenyl phosphate.

For these reasons, it is preferable that the waterproof sheet 30 be made of a vinyl chloride resin sheet made of a resin composition containing a vinyl chloride resin and a plasticizer. In this case, the vinyl chloride resin content in the waterproof sheet 30 is preferably, for example, 50% by weight or more and 95% by weight or less, and more preferably 60% by weight or more and 85% by weight or less. This allows the above-mentioned effects to be more pronounced.

The waterproof sheet 30 may be composed of a single layer of the resin sheet, or may have, for example, a fiber layer inserted in the middle of the thickness direction, i.e., a fiber layer (fiber sheet) sandwiched between a first resin layer and a second resin layer stacked in the thickness direction.

This fiber layer is composed of an aggregate of fibers, and examples include fiber sheets such as woven or nonwoven cloth, and nets with multiple lattices formed by warp and weft threads. By providing the waterproof sheet 30 with such a fiber layer, the strength (tear strength, tensile strength, etc.) and durability (resistance to repeated fatigue) of the waterproof sheet 30 can be improved.

The thickness of the waterproof sheet 30 is not particularly limited, but is preferably between 0.5 mm and 3 mm, and more preferably between 0.8 mm and 3 mm. This ensures that the floor 11 and wall 12 are securely covered by the waterproof sheet 30. Even if stress acts on the waterproof sheet 30 when water is stored or when swimmers swim, the waterproof sheet 30 can be effectively prevented from cracking early.

<<First Configuration Example>>
The waterproof sheet 50 (second waterproof sheet) is colored black and covers part of the waterproof sheet 30 (first waterproof sheet) to add design to the sheet waterproof structure 1. In this embodiment, as shown in Figure 1, it forms an indicator, i.e., a course line, that indicates the course along which the swimmer will swim.

In the sheet waterproofing structure 1, the waterproof sheet 50 of the present invention is used as the waterproof sheet (second waterproof sheet) that forms the course line. Specifically, the waterproof sheet 50 is composed of a laminate having a first layer 51 located on the side of the main body 10 and a second layer 52 laminated on the side of the first layer 51 opposite the main body 10. The second layer 52 contains a carbon material as a black coloring material, and the first layer 51 either does not contain the carbon material or the carbon material content is lower than the carbon material content in the second layer 52.

As explained in the background art section above, if the waterproof sheet (colored waterproof sheet) that makes up the course lines (markers) is made from a single layer containing a black pigment, as in the past, this waterproof sheet (single layer) would blister over time, marring the appearance of the course lines and even causing problems such as peeling between the course lines (colored waterproof sheet) and the waterproof sheet that serves as the base layer.

After extensive research into this issue, the inventors have concluded that the problem is likely related to a highly active (oxidizing) gas that is produced by a reaction between a carbon material, such as carbon black, which is the black coloring material (general-purpose black coloring material) contained in colored waterproof sheets, and hypochlorous acid contained in the water stored in the water tank (reserved water).

When a carbon material (black pigment) such as carbon black reacts with hypochlorous acid (HClO) in water, the carbon material acts as a catalyst, causing the reaction represented by formula (1) below to proceed, resulting in the decomposition of hypochlorous acid, generating a gas that exhibits high activity (oxidizing power) (hereinafter, this gas may be referred to as an "active gas").

HClO → HCl + O (↑) … (1)

It is believed that the reaction between this active gas and the resin material, such as vinyl chloride resin, contained in the colored waterproof sheet causes the resin material to change and deteriorate, resulting in swelling of the surface of the colored waterproof sheet over time. Considering that the reaction in equation (1) above is temperature-dependent and progresses more rapidly at high temperatures, increasing the rate of active gas generation, and that swelling of the surface of colored waterproof sheeting occurs more frequently in greenhouse pools, i.e., when the water temperature is between 25°C and 35°C, the above assumption is valid.

Therefore, the inventors conducted further research into the relationship between highly active gases and the occurrence of blistering on the surface of colored waterproof sheets. When active gas is generated by the reaction formula (1) above, it is generally believed that this active gas diffuses into the stored water. However, when active gas is generated near the joint interface where the waterproof sheet 30 laid on the structure 10 and the colored waterproof sheet are joined, this active gas alters and deteriorates the waterproof sheet 30 and the colored waterproof sheet at the joint interface, thereby allowing the stored water to penetrate the joint interface. If the stored water is allowed to penetrate the joint interface in this way and reaches the joint interface, the active gas generated at the joint interface has no way to escape. Therefore, it was hypothesized that this active gas accumulates at the joint interface over time, resulting in blistering on the surface of the colored waterproof sheet.

Therefore, in order to suppress or prevent the generation of active gas at the joint interface without reducing the visibility of the colored waterproof sheet, i.e., the course line (indicator), to swimmers, a need arose to reduce or eliminate the content of carbon material (black coloring material) on the surface of the colored waterproof sheet facing the waterproof sheet 30, without reducing the content of carbon material as a black coloring material on the surface of the colored waterproof sheet opposite the waterproof sheet 30. Therefore, the inventors concluded that the above requirements could be met by constructing a colored waterproof sheet, like waterproof sheet 50, as a laminate having a first layer 51 located on the waterproof sheet 30 (body 10) side and a second layer 52 laminated on the side of the first layer 51 opposite the waterproof sheet 30 (body 10), and further, the second layer 52 containing a carbon material (black coloring material) to ensure swimmers' visibility of the course line (markers). Furthermore, the first layer 51 either not containing carbon material or containing a lower carbon material content than the second layer 52, thereby completing the present invention.

As described above, in this configuration example, the waterproof sheet 50 of the present invention is composed of a laminate of a first layer 51 and a second layer 52. The first layer 51 and the second layer 52 differ in the amount of carbon material (black coloring material) contained therein, and the first layer 51 either does not contain carbon material or the carbon material content is set lower than the carbon material content in the second layer 52. Other than this, the constituent materials are identical.

Furthermore, waterproof sheet 50 and waterproof sheet 30 have the same structure, except that waterproof sheet 50 contains a carbon material as a black coloring material, while waterproof sheet 30 does not contain a carbon material, and are made of a resin composition containing a resin material, as previously described for waterproof sheet 30. Therefore, explanations of anything other than the carbon material contained solely in waterproof sheet 50 will be omitted here.

The carbon material is included in the waterproof sheet 50 as a black coloring material, which makes the waterproof sheet 50 distinguishable from the waterproof sheet 30 and therefore functions as a course line, i.e., an indicator. In the present invention, the waterproof sheet 50 is composed of a laminate of a first layer 51 and a second layer 52, and of these first layer 51 and second layer 52, the first layer 51 does not contain any carbon material, or the carbon material content is set to be lower than the carbon material content in the second layer 52. This effectively suppresses or prevents the generation of active gas at the bonding interface between the waterproof sheet 30 and the waterproof sheet 50 (first layer 51).

The carbon material is not particularly limited as long as it can be used as a black colorant, but examples include carbon black, acetylene black, ketjen black, fullerene, carbon nanotubes, and graphene. One or more of these can be used in combination, but carbon black is preferred. Adding a relatively small amount of carbon black to the second layer 52 can make the second layer 52 (waterproof sheet 50) distinguishable from the waterproof sheet 30, making it a preferred carbon material (black colorant). Furthermore, carbon black is a carbon material that reliably participates catalytically in the reaction represented by formula (1). Therefore, applying the present invention when carbon black is included as a carbon material in the second layer 52 can more significantly enhance the effects of the present invention.

The carbon material content in the second layer 52, i.e., the carbon material content in the resin composition containing the resin material that makes up the second layer 52, is not particularly limited, but is preferably, for example, approximately 0.2% by weight to 5.0% by weight, and more preferably approximately 0.4% by weight to 3.0% by weight. This ensures that the waterproof sheet 50, which has the second layer 52 as its outermost surface, is provided with the function of a course line, i.e., an indicator.

Furthermore, when the content of the carbon material contained in the first layer 51 is A [wt %] and the content of the carbon material contained in the second layer 52 is B [wt %], A/B preferably satisfies the relationship 0≦A/B≦0.6, more preferably 0≦A/B≦0.25, and even more preferably 0≦A/B≦0.15. Satisfying this relationship ensures that the second layer 52 functions as a course line (marker), while accurately suppressing or preventing the generation of active gas at the bonding interface between the waterproof sheet 30 and the first layer 51.

In addition, in the waterproof sheet 50, the thickness of the second layer 52 is not particularly limited, but is preferably, for example, approximately 0.4 mm to 5 mm, and more preferably, approximately 0.7 mm to 2.5 mm. Furthermore, the thickness of the first layer 51 is not particularly limited, but is preferably, for example, approximately 0.3 mm to 3 mm, and more preferably, approximately 0.5 mm to 1.5 mm. This ensures that the second layer 52 functions as a course line (marker). Furthermore, the first layer 51 ensures reliable bonding to the waterproof sheet 30.

In this embodiment, the markers installed on the body 10 (water tank), i.e., the pool, are the lane lines shown in Figure 1, in other words, the lane lines are constructed from the waterproof sheet 50 of the present invention. However, in addition to lane lines, other markers that may be installed on the pool include, for example, a 5m line and a center line on the floor 11 to indicate the swimmer's swimming position, and water level indicators on the wall 12 to indicate the pool's depth. If these markers are colored black, they can also be made from the waterproof sheet 50, just like the lane lines, thereby effectively suppressing or preventing swelling of the surface of the waterproof sheet 50 over time. As a result, peeling between the waterproof sheet 50 (colored waterproof sheet) and the waterproof sheet 30 is effectively suppressed or prevented over a long period of time, maintaining the excellent appearance of each marker.

<<Second Configuration Example>>
Next, a second configuration example of the waterproof sheet 50 (second waterproof sheet) of the present invention provided in the sheet waterproof structure 1 will be described.

Figure 3 is a vertical cross-sectional view taken along line A-A, showing the second waterproof sheet provided in the sheet waterproofing structure shown in Figure 1 when configured in the second configuration example.

The following describes the waterproof sheet 50 of the second configuration example, focusing on the differences from the waterproof sheet 50 of the first configuration example, and omitting explanations of similar points.

The waterproof sheet 50 shown in Figure 3 is the same as the waterproof sheet 50 shown in Figure 1, except for the layer structure of the waterproof sheet 50.

That is, the waterproof sheet 50 of the second configuration example further has a fiber layer 53 containing a fiber material interposed between the first layer 51 and the second layer 52. In other words, the waterproof sheet 50 of the second configuration example has a configuration in which the fiber layer 53 (fiber sheet) is sandwiched between the first layer 51 and the second layer 52 that are stacked in the thickness direction.

This fiber layer 53 is composed of an aggregate of fibers, and examples include a fiber sheet such as a woven or nonwoven cloth, or a net with multiple lattices formed by warp and weft threads. By configuring the waterproof sheet 50 to include such a fiber layer 53 between the first layer 51 and the second layer 52, even if active gas is generated at the interface between the waterproof sheet 30 and the first layer 51 and swelling occurs in the first layer 51, the restraining force of the fiber layer 53 (net) can effectively suppress or prevent the swelling in the first layer 51 from spreading to the upper surface of the second layer 52.

Fiber materials contained in the fiber layer 53 include, for example, natural cellulosic fibers such as cotton and hemp, natural protein fibers such as silk and wool, rayon, cupra, acetate, triacetate, polyamide, polyester, polyurethane, acrylic, vinylon, polyolefin, and vinylidene chloride, and one or more of these can be used in combination.

The waterproof sheet 50 of the second configuration example, which is provided in the sheet waterproof structure 1 and has such a configuration, also provides the same effects as those of the first configuration example.
The dimensions of each part are the same as those of the waterproof sheet 50 of the first configuration example.

The waterproof sheet and sheet waterproofing structure of the present invention have been described above, but the present invention is not limited to these.

For example, in the waterproof sheet and sheet waterproof structure of the present invention, each component can be replaced with any component that can perform a similar function, or any component can be added.

In addition, in the above embodiment, we have described a case where the waterproof sheet (first waterproof sheet) covering the main body 10 and the colored waterproof sheet (second waterproof sheet) used to add design features to the main body 10 are made of the waterproof sheet 50 of the present invention. However, this is not limited to this. For example, if the waterproof sheet (first waterproof sheet) covering the main body 10 contains a black coloring material in order to add design features to the waterproof sheet, the waterproof sheet (first waterproof sheet) can also be made of the waterproof sheet 50 of the present invention.

Next, specific examples of the present invention will be described.
However, the present invention is not limited to the descriptions in these examples.

1. Preparation of colored waterproof sheet [Example 1]
First, particles (average particle size 1 μm) composed of a vinyl chloride monomer polymer were prepared as the vinyl chloride resin, DINP (diisononyl phthalate) was prepared as the plasticizer, and carbon black (manufactured by Mitsubishi Chemical Corporation, "Mitsubishi Carbon Black #45") was prepared as the carbon material (black coloring material). These were then uniformly mixed at 25°C using a mixer in a mixing ratio of 65.00 wt% vinyl chloride resin, 35.00 wt% plasticizer, and 0.00 wt% carbon material to obtain resin composition A, and these were uniformly mixed at 25°C using a mixer in a mixing ratio of 64.58 wt% vinyl chloride resin, 35.00 wt% plasticizer, and 0.42 wt% carbon material to obtain resin composition B.

Next, a polyester cloth resin fiber sheet ("Clenet" manufactured by Kurabo Industries, Ltd.) was prepared as the fiber layer 53.

Next, resin composition A and resin composition B were each heated and kneaded, and then formed into sheets using rolls to form the heated first layer 51 and second layer 52. These heated first layer 51 and second layer 52 were then laminated to the front and back surfaces of fiber layer 53 (glass fiber layer), respectively, and cooled to obtain the colored waterproof sheet of Example 1.

The planar dimensions of the colored waterproof sheet of Example 1 were 100 mm long and 100 mm wide. The thicknesses of the first layer 51 and second layer 52 were 0.70 μm and 0.80 mm, respectively.

[Examples 2 and 3, Comparative Example 1]
The colored waterproof sheets of Examples 2 and 3 were prepared in the same manner as in Example 1, except that the vinyl chloride, plasticizer, and carbon material were mixed in the mixing ratios shown in Table 1 and uniformly mixed at 25°C using a mixer to obtain resin composition A.

[Example 4]
The colored waterproof sheet of Example 4 was produced in the same manner as Example 1, except that the colored waterproof sheet was formed by cooling the heated first layer 51 and second layer 52 with the surface of the first layer 51 directly bonded to the back surface of the second layer 52, without using the fiber layer 53 in between.

[Comparative Examples 2 and 3]
The colored waterproof sheets of Comparative Examples 2 and 3 were prepared in the same manner as in Example 4, except that the vinyl chloride, plasticizer, and carbon material were mixed in the mixing ratios shown in Table 1 and uniformly mixed at 25°C using a mixer to obtain resin composition A.

2. Attachment of Colored Waterproof Sheet to Waterproof Sheet Next, the colored waterproof sheets of each Example and Comparative Example were attached to the waterproof sheet 30, respectively.

More specifically, a waterproof sheet 30 containing 100 parts by weight of vinyl chloride resin and 50 parts by weight of plasticizer was prepared, and the colored waterproof sheets of each example and comparative example were attached to this waterproof sheet 30 with the second layer 52 facing the waterproof sheet 30.

3. Evaluation The colored waterproof sheets of each Example and Comparative Example were evaluated using the following methods.

That is, first, the waterproof sheets 30 to which the colored waterproof sheets of each example and each comparative example were attached were each immersed in an aqueous sodium hypochlorite solution (chlorine concentration: 2000 ppm, temperature: 60°C).

The colored waterproof sheets of each example and comparative example were then observed for the presence or absence of blisters on the surface of the second layer 52 and for the presence or absence of peeling between the colored waterproof sheet (first layer 51) and the waterproof sheet 30, and these were evaluated according to the following criteria.

(Evaluation of Blisters on the Surface of the Second Layer 52)
After immersion in the sodium hypochlorite aqueous solution, the occurrence of swelling on the surface of the second layer 52 was as follows: ◎: No swelling was observed even after 70 days; ○: Slight swelling was observed after 70 days, but no discomfort was observed; △: Slight swelling was observed after 70 days, but
Not recognized after 40 days ×: Recognized after 40 days

(Evaluation of peeling between colored waterproof sheet and waterproof sheet 30)
After immersion in a sodium hypochlorite solution,
Peeling between the colored waterproof sheet and the waterproof sheet 30: ◎: Not observed even after 70 days ○: Slight peeling observed after 70 days, but no discomfort observed △: Peeling observed after 70 days, but
No change was observed after 40 days. ×: Change was observed after 40 days. The results of these evaluations are shown in Table 1.

As shown in Table 1, in the colored waterproof sheets of each example, the relationship A/B between the carbon material content A [wt %] in the first layer 51 and the carbon material content B [wt %] in the second layer 52 satisfies A/B < 1.0. In other words, the carbon material content in the first layer 51 is lower than the carbon material content in the second layer 52, and the occurrence of blisters on the surface of the second layer 52 and further peeling between the colored waterproof sheet (waterproof sheet 50) and the waterproof sheet 30 are suppressed or prevented.

In contrast, in the colored waterproof sheets of each comparative example, the relationship A/B did not satisfy A/B<1.0. In other words, the carbon material content in the first layer 51 was not lower than the carbon material content in the second layer 52. As a result, swelling occurred on the surface of the second layer 52, and even peeling occurred between the colored waterproof sheet and the waterproof sheet 30.

REFERENCE SIGNS LIST 1 Sheet waterproof structure 10 Body 11 Floor portion 12 Wall portion 13 Corner portion 20 Arrangement member 21 First portion 22 Second portion 30 Waterproof sheet 50 Waterproof sheet 51 First layer 52 Second layer 53 Fiber layer

Claims (8)

A waterproof sheet used to waterproof a building frame and made primarily of resin material,
a first layer located on the side of the frame and a second layer stacked on the side of the first layer opposite to the frame,
the second layer contains a carbon material as a black coloring material,
The waterproof sheet is characterized in that the first layer contains the carbon material , and the content of the carbon material is lower than the content of the carbon material in the second layer. The structure is waterproofed by a first waterproof sheet covering the structure and a second waterproof sheet laminated on a part of the first waterproof sheet opposite the structure and providing a design to the structure;
The waterproof sheet according to claim 1 , which is used as the second waterproof sheet. The waterproof sheet according to claim 2, wherein the structure is a pool having a floor and walls extending from the floor, and is primarily made of concrete, metal, or fiber-reinforced plastic. The body is a water tank provided in the pool,
The waterproof sheet according to claim 3, wherein the second waterproof sheet is laminated on the first waterproof sheet as a course line indicating a course for a swimmer to swim. The waterproof sheet according to any one of claims 1 to 4, further comprising a fiber layer containing a fibrous material interposed between the first layer and the second layer. The waterproof sheet according to any one of claims 1 to 5, wherein the carbon material is carbon black. A waterproof sheet as described in any one of claims 1 to 6, wherein when the content of the carbon material contained in the first layer is A [wt %] and the content of the carbon material contained in the second layer is B [wt %], A/B satisfies the relationship 0.17 ≦ A/B ≦ 0.6. A sheet waterproofing structure comprising the waterproof sheet according to any one of claims 1 to 7 and a positioning member for fixing the waterproof sheet to the frame.