Anti-slip protective sheets and slope protection structures

Abstract

This product provides a slip-resistant protective sheet that offers excellent anti-slip functionality for heavy objects and superior fixing strength for connecting parts. [Solution] An anti-slip protective sheet comprising a first nonwoven fabric and a resin composition attached to one surface of the first nonwoven fabric, wherein the resin composition comprises particles and a binder resin, and the first nonwoven fabric comprises core-sheath fibers having a core and a sheath, and the melting point of the resin contained in the sheath is lower than the melting point of the resin contained in the core.

Description

[Technical Field]

[0001] This invention relates to an anti-slip protective sheet and a slope protection structure. [Background technology]

[0002] Levees built along rivers deteriorate due to the infiltration of river water, etc., so in order to prevent deterioration, the slopes of the levees are sometimes covered with waterproof sheets or the like for protection. For example, Patent Document 1 discloses a waterproof structure in which a waterproof sheet protected by a protective mat is laid along the slope formed on the bank, and bags filled with soil filler are further laid on the upper surface of the protective mat, wherein an anti-slip treatment is applied to at least the side of the protective mat that is in contact with the bags, or at least the side of the bags that is in contact with the protective mat. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2007-126902 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Conventional protective sheets for protecting the slopes of embankments, such as those disclosed in Patent Document 1, have an anti-slip function for heavy objects placed on the sheet to prevent it from floating up. Such anti-slip protective sheets are often installed on slopes in a connected state, but the inventors have found that when the ends of multiple anti-slip protective sheets are connected to each other by heat fusion or the like, the fixing force of the connection may be reduced. The present invention has been made in view of the above circumstances, and its objective is to provide an anti-slip protective sheet with excellent anti-slip function for heavy objects and excellent fixing force of the connection. Another objective is to provide a slope protection structure with excellent anti-slip function for heavy objects and excellent fixing force of the connection. [Means for solving the problem]

[0005] An anti-slip protective sheet according to an embodiment of the present invention is as follows [1]. [1] A first nonwoven fabric and a resin composition attached to one surface of the first nonwoven fabric, The aforementioned resin composition comprises particles and a binder resin. The first nonwoven fabric includes core-sheath fibers having a core and a sheath, The anti-slip protective sheet has a lower melting point for the resin contained in the sheath than for the resin contained in the core.

[0006] The resin composition adhering to one surface of the nonwoven fabric contains particles and a binder resin, which improves the surface friction and enhances the anti-slip function against heavy objects. Furthermore, in the core-sheath fibers of the nonwoven fabric, the melting point of the resin contained in the sheath portion is lower than the melting point of the resin contained in the core portion, which makes it easier for the sheath portion to fuse when multiple anti-slip protective sheets are joined by heat fusion, while the core portion maintains the shape of the fibers. As a result, the strength of the joint is improved and the fixing force is enhanced. The anti-slip protective sheet and slope protection structure according to the embodiment are preferably any of the following [2] to [7]. [2] Furthermore, the material comprises a second nonwoven fabric and a waterproof sheet, The second nonwoven fabric, the waterproof sheet, and the first nonwoven fabric are laminated in order. The other surface of the first nonwoven fabric is facing the waterproof sheet, The second nonwoven fabric contains core-sheath fibers having a core and a sheath, The anti-slip protective sheet described in [1], wherein the melting point of the resin contained in the sheath portion is lower than the melting point of the resin contained in the core portion. [3] The air permeability of the anti-slip protective sheet according to JIS L1096:2010 8.26.1 Method A (Fragile method) is 3 to 25 cm 3 / cm 2 • sec, The aforementioned particles are inorganic particles, The anti-slip protective sheet according to [1] or [2], wherein the content of the inorganic particles in 100% by mass of the resin composition is 40 to 95% by mass. [4] The first nonwoven fabric has a length direction and a width direction, One surface of the first nonwoven fabric has at least one non-adhered portion which is a portion to which the resin composition is not adhered, The anti-slip protective sheet according to any one of [1] to [3], wherein the at least one non-adhered portion is located at one end, the other end, or both ends in the width direction. [5] The anti-slip protective sheet according to any one of [1] to [4], wherein a coefficient of static friction between one surface of the first nonwoven fabric to which the resin composition is adhered and an attached white fabric for color fastness testing (polyester No. 8-1) specified in JIS L0803:2011 is 0.60 to 0.90. [6] The anti-slip protective sheet according to any one of [2] to [5], wherein the waterproof sheet is a nonwoven fabric. [7] The anti-slip protective sheet according to any one of [1] to [6], A slope protection structure, comprising: the anti-slip protective sheet; and a heavy object disposed on one surface of the first nonwoven fabric of the anti-slip protective sheet.

Effect of the Invention

[0007] With the above configuration, an anti-slip protective sheet excellent in an anti-slip function against heavy objects and a fixing force of a connecting portion can be provided. Further, a slope protection structure excellent in an anti-slip function against heavy objects and a fixing force of a connecting portion can be provided.

Brief Description of Drawings

[0008] [Figure 1] FIG. 1 is a plan view of the anti-slip protective sheet according to an embodiment. [Figure 2] FIG. 2 is a II-II cross-sectional view of the anti-slip protective sheet of FIG. 1. [Figure 3] FIG. 3 is a side view of a slope protection structure including the anti-slip protective sheet of FIG. 1 and a filler-filled bag body (heavy object) that is arranged on a slope.

Mode for Carrying Out the Invention

[0009] The anti-slip protective sheet according to the embodiment comprises a first nonwoven fabric and a resin composition attached to one surface of the first nonwoven fabric. The resin composition includes particles and a binder resin. The first nonwoven fabric includes core-sheath fibers having a core and a sheath, with the melting point of the resin in the sheath being lower than that of the resin in the core. The resin composition attached to one surface of the nonwoven fabric, containing particles and a binder resin, improves the surface friction and enhances the anti-slip function against heavy objects. Furthermore, because the melting point of the resin in the sheath of the core-sheath fibers of the nonwoven fabric is lower than that of the resin in the core, the sheath is more easily fused when multiple anti-slip protective sheets are joined by heat fusion, while the core maintains the shape of the fibers. As a result, the strength of the joint is improved, and the fixing force is enhanced.

[0010] The following describes in detail the anti-slip protective sheet and the slope protection structure according to the embodiment, with reference to Figures 1 to 3. Figure 1 is a plan view of the anti-slip protective sheet according to the embodiment. Figure 2 is a cross-sectional view taken along line II-II of the anti-slip protective sheet of Figure 1. Figure 3 is a side view of the slope protection structure, which has the anti-slip protective sheet of Figure 1 and a bag (heavy object) filled with a filler, when placed on a slope.

[0011] As shown in Figures 1 and 2, the anti-slip protective sheet 10 of the embodiment has a first nonwoven fabric 1 and a resin composition 4 attached to one surface 1A of the first nonwoven fabric 1. The resin composition 4 contains particles 4P and a binder resin 4B.

[0012] The presence of particles 4P in the resin composition 4 improves the frictional force of one surface 1A of the first nonwoven fabric 1. The average particle size of particles 4P is preferably 20 to 2000 μm, more preferably 50 to 500 μm. An average particle size of 20 μm or more improves the frictional force. On the other hand, an average particle size of 2000 μm or less makes it easier to adhere the particles 4P to the first nonwoven fabric 1 via the binder resin 4B.

[0013] Examples of particle 4P include inorganic particles, organic particles, particles having a resin layer on the surface of inorganic particles, or combinations thereof. Of these, inorganic particles are particularly preferred. The inorganic particles preferably contain silica sand, and more preferably contain No. 8 silica sand. Silica sand has excellent handling properties, and No. 8 silica sand in particular has excellent slip resistance against the cloth bags described later. Specifically, No. 8 silica sand is silica sand with a particle size of No. 8 as described in JIS G 5901:2016. Other examples of particle 4P may include sand obtained by calcining sea sand, or recycled materials such as powdered concrete, wall materials, and roof tiles generated at building demolition sites.

[0014] The inorganic particle content of resin composition 4 is preferably 40 to 95% by mass per 100% by mass. A inorganic particle content of 40% by mass or more improves slip resistance. More preferably 50% by mass or more, and even more preferably 60% by mass or more. On the other hand, a inorganic particle content of 95% by mass or less reduces the amount of inorganic particle detachment. More preferably 90% by mass or less, and even more preferably 85% by mass or less. The preferred range for the content of particle 4P is similar.

[0015] The binder resin 4B should be capable of adhering particles 4P to one surface 1A of the first nonwoven fabric 1. The binder resin 4B preferably contains an acrylic resin, a vinyl resin, a rubber resin, or a combination thereof, and more preferably contains an acrylic resin. Acrylic resins, in particular, are excellent in terms of durability, ease of handling during manufacturing, cost, and adhesion. Examples of acrylic resins include homopolymers of acrylic acid, methacrylic acid, or acrylic acid esters, and copolymers of at least two monomers selected from the group consisting of acrylic acid, methacrylic acid, acrylic acid esters, and other monomers. Examples of vinyl resins include polyvinyl acetate, polyvinyl chloride, polyvinyl alcohol, and ethylene-vinyl acetate copolymers. Examples of rubber resins include styrene-butadiene rubber and acrylonitrile-butadiene rubber. These may be used individually or in combination of two or more. In forming the binder resin 4B attached to one surface 1A of the first nonwoven fabric 1, it is preferable to use an emulsion in which a polymer is dispersed in a solvent.

[0016] Preferably, the content of binder resin 4B in 100% by mass of resin composition 4 is 5 to 60% by mass. A binder resin 4B content of 5% by mass or more makes it easier for particles 4P to adhere to the first nonwoven fabric 1. More preferably, it is 10% by mass or more, and even more preferably 15% by mass or more. On the other hand, a binder resin 4B content of 60% by mass or less allows for a larger particle 4P content, thereby improving frictional force. More preferably, it is 50% by mass or less, and even more preferably 40% by mass or less.

[0017] The basis weight of resin composition 4 is preferably 50 to 180 g / m². 2 Comfortable 60-150g / m 2 The weight is 50g / m². 2 As a result of the above, the frictional force is improved. On the other hand, the basis weight is 180g / m 2 The following factors ensure that breathability is not compromised.

[0018] The first nonwoven fabric 1 contains core-sheath fibers having a core and a sheath. The melting point of the resin contained in the sheath is lower than the melting point of the resin contained in the core. Because the melting point of the resin contained in the sheath fibers of the first nonwoven fabric 1 is lower than the melting point of the resin contained in the core, when multiple first nonwoven fabrics 1 are joined by heat fusion, the sheath melts, making it easier to join them. On the other hand, because the melting point of the resin contained in the core is higher than the melting point of the resin contained in the sheath, when multiple first nonwoven fabrics 1 are joined by heat fusion, the shape of the fibers is maintained by the core, improving the strength of the joined parts. Furthermore, because the shape of the fibers is maintained by the core, the voids within the first nonwoven fabric 1 are also more easily maintained, thus reducing the deterioration of air permeability associated with the formation of joined parts. The content of core-sheath fibers in 100% by mass of the first nonwoven fabric 1 is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. On the other hand, the content may be 100% by mass or less, 98% by mass or less, or 95% by mass or less. That is, the first nonwoven fabric 1 may contain fibers other than core-sheath fibers.

[0019] The melting point of the resin contained in the sheath is preferably 90 to 170°C, and more preferably 95 to 140°C. This further improves the adhesive strength obtained by heat fusion. The melting point of the resin contained in the core is preferably 180 to 350°C, and more preferably 200 to 300°C. This reduces the risk of the fiber structure deforming into a film-like shape during heat fusion, and thus further reduces the deterioration of breathability associated with the formation of the connecting portion.

[0020] Examples of resins used in the core include polyester resins such as polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate; polyamide resins; acrylic resins such as polyacrylonitrile; polyvinyl alcohol resins; and fluorocarbon resins. Of these, polyester resins are particularly preferred, with polyethylene terephthalate being the most preferred. This improves the strength of the core-sheath fiber. These can be used individually or in combination of two or more.

[0021] Examples of resins contained in the sheath portion include polyolefin resins such as polypropylene and polyethylene. Only one of these may be used alone, or two or more thereof may be used in combination. Among these, polyethylene is most preferable. This improves the durability of the core-sheath fiber and facilitates heat fusion during the formation of the connecting portion.

[0022] In the core-sheath fiber, the content of the sheath portion is preferably 50 to 150 parts by mass, more preferably 80 to 120 parts by mass, relative to 100 parts by mass of the core portion. This facilitates the exhibition of both properties of the sheath portion and the core portion.

[0023] The density of the first nonwoven fabric 1 is preferably 0.03 to 0.20 g / cm 3 , and more preferably 0.05 to 0.15 g / cm 3 . When the density is 0.03 g / cm 3 or more, the adhesive strength of the first nonwoven fabric 1 during heat fusion is improved. On the other hand, when the density is 0.20 g / cm 3 or less, the first nonwoven fabric 1 is easily immersed in water.

[0024] The basis weight of the first nonwoven fabric 1 is preferably 100 to 600 g / m 2 , more preferably 200 to 500 g / m 2 . When the basis weight is 100 g / m 2 or more, the penetration resistance of the anti-slip protective sheet 10 against protrusions is improved. On the other hand, when the basis weight is 600 g / m 2 or less, the first nonwoven fabric 1 is easily immersed in water. The basis weight can be measured in accordance with the provisions of JIS L1096 (2010) 8.3.2 Method A. The thickness of the first nonwoven fabric 1 is preferably 0.20 to 6 mm, more preferably 0.8 to 5 mm.

[0025] The fineness of the fibers contained in the first nonwoven fabric 1 is preferably 1 to 10 dtex, and more preferably 2 to 6 dtex. A fineness of 1 dtex or more makes the first nonwoven fabric 1 easier to immerse in water. On the other hand, a fineness of 10 dtex or less improves the durability of the anti-slip protective sheet 10 against protrusions. The fineness can be measured according to the provisions of JIS L 1015:2010.

[0026] As shown in Figures 1 and 2, it is preferable that the first nonwoven fabric 1 has a length direction 1Y and a width direction 1X. In other words, the fact that the first nonwoven fabric 1 extends in the length direction 1Y makes it easier to attach the anti-slip protective sheet 10 from the top to the bottom of the slope. The shape of the first nonwoven fabric 1 in plan view is preferably a square, and more preferably a rectangle.

[0027] Preferably, one surface 1A of the first nonwoven fabric 1 has at least one non-adherent portion 1D, which is a portion to which the resin composition 4 is not attached. For example, by providing non-adherent portions 1D at each end of a plurality of anti-slip protective sheets 10 and heat-sealing the ends of the plurality of anti-slip protective sheets 10 together, the plurality of anti-slip protective sheets 10 can be connected.

[0028] Preferably, at least one non-adherent portion 1D is located at one end 1E, the other end 1F, or both ends in the width direction 1X, and more preferably at both ends of one end 1E and the other end 1F. This allows multiple anti-slip protective sheets 10 to be connected, for example, by heat-sealing the ends of the anti-slip protective sheets 10 together in the width direction 1X after they have been attached from the top to the bottom of the slope. Furthermore, when connecting multiple anti-slip protective sheets 10, heat-sealing the portions 10D including the non-adherent portion 1D together reduces the deterioration of breathability associated with the formation of the connection. Alternatively, when connecting multiple anti-slip protective sheets 10, the portions 10C including the adhesive portion 1C may be heat-sealed together. In this case, since the connection is made via the resin composition 4, the fixing strength of the connection is further improved. In addition, the portion 10D including the non-adherent portion 1D and the portion 10C including the adhesive portion 1C may be heat-sealed together.

[0029] The length of the non-adhesive portion 1D in the width direction 1X is preferably 3 to 12%, and more preferably 4 to 6%, relative to 100% of the length of one surface 1A of the first nonwoven fabric 1 in the width direction 1X. A length of 3% or more makes it easier to heat-seal and connect multiple anti-slip protective sheets 10, including the non-adhesive portion 1D. This makes it easier to prevent water from seeping in from the connection points. On the other hand, a length of 10% or less suppresses a decrease in the anti-slip properties and breathability of the multiple anti-slip protective sheets 10 after heat-sealing, and reduces costs. If there are multiple non-adhesive portions 1D, the length of the non-adhesive portion 1D in the width direction 1X mentioned above is the length of one non-adhesive portion 1D in the width direction 1X.

[0030] The length of the non-adherent portion 1D in the longitudinal direction 1Y is preferably 90% or more, more preferably 95% or more, and most preferably 100% of the length of one surface 1A of the first nonwoven fabric 1 in the longitudinal direction 1Y. This makes it easier to prevent water from seeping in from the connecting portion. If there are multiple non-adherent portions 1D, the length of the non-adherent portion 1D in the longitudinal direction 1Y as described above is the length of each non-adherent portion 1D in the longitudinal direction 1Y.

[0031] The first nonwoven fabric 1 may be, for example, a spunbond nonwoven fabric or a meltblown nonwoven fabric, but it is preferably a spunbond nonwoven fabric. This improves the strength of the anti-slip protective sheet 10.

[0032] The first nonwoven fabric 1 is preferably formed by pressure bonding a web made of long fibers. Examples of pressure bonding methods include bonding by pressure using a smooth calender roll, engraving roll, or other pressure bonding roll. While bonding may be achieved solely by pressure bonding with a roll, adhesives such as resin binder liquid, powder adhesive, or fibrous adhesive may also be used.

[0033] The first nonwoven fabric 1 is preferably formed by intertwining a web with a needle punch, and more preferably formed by intertwining a web with a needle punch after pressure bonding. This improves the strength of the anti-slip protective sheet 10.

[0034] The first nonwoven fabric 1 may also be formed by mechanically entangling the web using methods such as stitching or spunlacing, and then pressing the web with various types of rolls.

[0035] Preferably, the static friction coefficient between one surface 1A of the first nonwoven fabric 1 to which the resin composition 4 is attached and the attached white cloth (polyester 8-1) for color fastness testing described in JIS L0803:2011 is 0.60 to 0.90. A static friction coefficient of 0.60 or higher improves the anti-slip function for heavy objects placed on the anti-slip protective sheet 10. More preferably, the static friction coefficient is 0.62 or higher, and even more preferably 0.65 or higher. On the other hand, a static friction coefficient of 0.90 or lower can reduce manufacturing costs. More preferably, the static friction coefficient is 0.80 or lower, and even more preferably 0.75 or lower. The friction coefficient can be measured by the method described in the examples.

[0036] Preferably, the static friction coefficient between one surface of the anti-slip protective sheet 10 and the other surface opposite to that surface is 0.60 to 0.90. This makes it less likely for the sheet to shift when the anti-slip protective sheet 10 is wound into a roll, resulting in excellent workability and handling. More preferably, the static friction coefficient is 0.62 to 0.80, and even more preferably 0.65 to 0.75.

[0037] As shown in Figure 2, it is preferable that the anti-slip protective sheet 10 further comprises a second nonwoven fabric 2 and a waterproof sheet 3. Furthermore, it is preferable that the second nonwoven fabric 2, the waterproof sheet 3, and the first nonwoven fabric 1 are laminated in order, and that the other surface 1B of the first nonwoven fabric 1 faces the waterproof sheet 3. The waterproof sheet 3 can improve the waterproofness of the anti-slip protective sheet 10. The waterproof sheet 3 only needs to be waterproof, but it is preferable that it is breathable. Furthermore, the above lamination order allows the first nonwoven fabric 1 and the second nonwoven fabric 2 to function as protective layers for the waterproof sheet 3. Note that the anti-slip protective sheet 10 may also have the first nonwoven fabric 1 but not the second nonwoven fabric 2 and the waterproof sheet 3. In this case, it is preferable that the first nonwoven fabric 1 has a water-repellent agent, which will be described later.

[0038] Preferably, the first nonwoven fabric 1 and the second nonwoven fabric 2 each contain fibers with a finer fineness than the fibers contained in the waterproof sheet 3. This makes it easier to maintain the shape of the fibers in the connecting portion when the nonwoven fabrics are heat-fused together to form a connecting portion.

[0039] The second nonwoven fabric 2 contains core-sheath fibers having a core and a sheath, and it is preferable that the melting point of the resin contained in the sheath is lower than the melting point of the resin contained in the core. Thus, it is preferable that the core-sheath fibers of the second nonwoven fabric 2 have the same structure as the core-sheath fibers of the first nonwoven fabric 1. This makes it possible to connect multiple anti-slip protective sheets 10 by overlapping and heat-sealing the ends of the first nonwoven fabric 1 of one anti-slip protective sheet 10 and the second nonwoven fabric 2 of another anti-slip protective sheet 10. For details of the composition, content, and other aspects of the core-sheath fibers, refer to the description of the first nonwoven fabric 1. In that case, refer to the first nonwoven fabric 1 as the second nonwoven fabric 2.

[0040] It is preferable that the second nonwoven fabric 2 has the same structure as the first nonwoven fabric 1. For details regarding the density, thickness, basis weight, fiber fineness, shape, type, and formation method of the second nonwoven fabric 2, please refer to the description of the first nonwoven fabric 1. In that case, you can refer to the description of the first nonwoven fabric 1 by substituting it with the second nonwoven fabric 2. However, it is preferable that the second nonwoven fabric 2 does not contain the resin composition 4. This improves the breathability of the anti-slip protective sheet 10. Similarly, it is preferable that the second nonwoven fabric 2 and the waterproof sheet 3 do not contain the resin composition 4.

[0041] The thickness of the waterproof sheet 3 is preferably 0.10 to 5 mm, and more preferably 0.20 to 4 mm. The basis weight of the waterproof sheet 3 is preferably 30 to 100 g / m². 2 Comfortably 50-90g / m 2 This makes it easier to achieve both waterproofing and breathability.

[0042] The waterproof sheet 3 is preferably a nonwoven fabric. This ensures that breathability is not compromised. If the waterproof sheet 3 is a nonwoven fabric, it is preferable that the nonwoven fabric contains a water repellent. The water repellent may be attached to the surface of the fibers constituting the nonwoven fabric or may be contained within the fibers. Examples of water repellents include fluororesin-based water repellents and silicone resin-based water repellents. The fibers constituting the nonwoven fabric may contain, for example, polyolefin resins, polyester resins, polyamide resins, acrylic resins, polyvinyl alcohol-based resins, fluorocarbon resins, etc. Of these, polyolefin resins are preferred. These may be used individually or in combination of two or more. The waterproof sheet 3 may also be a synthetic resin sheet such as a polyvinyl chloride sheet or a polyethylene sheet.

[0043] The air permeability of the anti-slip protective sheet 10 according to JIS L1096:2010 8.26.1 Method A (Fragile method) is 3-25 cm. 3 / cm 2 It is preferable that the air permeability of the anti-slip protective sheet 10 is low. If the air permeability of the anti-slip protective sheet 10 is low, water vapor emitted from the slope will increase the air pressure in the gap between the slope and the anti-slip protective sheet 10, and especially at high water levels or when the embankment overflows, an uplift pressure will act on the anti-slip protective sheet 10, which may damage the embankment or the anti-slip protective sheet 10 when it peels off, but if the air permeability is 3 cm 3 / cm 2 A ventilation rate of 5 cm or more allows air to be expelled, reducing such risks. 3 / cm 2 • sec or longer, more preferably 7 cm 3 / cm 2 It is 25cm or more. On the other hand, the air permeability is 25cm 3 / cm 2By keeping the permeability below 1.5cm, the amount of fluid such as air passing through the anti-slip protective sheet 10 can be reduced, and as a result, it becomes easier to prevent the detachment of particles 4P, such as inorganic particles. This detachment prevention effect by controlling the permeability is particularly effective when the inorganic particle content in the resin composition 4 is 40 to 95% by mass. The permeability is more preferably 15cm. 3 / cm 2 • sec or less, more preferably 10 cm 3 / cm 2 The value is less than or equal to .sec. For example, as shown in Figure 2, if one surface 1A of the first nonwoven fabric 1 has an attached portion 1C to which the resin composition 4 is attached and a non-attached portion 1D to which it is not attached, then the air permeability is the air permeability of the portion 10C of the anti-slip protective sheet 10 that includes the attached portion 1C. For details on the method of measuring the air permeability, please refer to the description in the examples.

[0044] The air permeability of the portion 10D of the anti-slip protective sheet 10, including the non-adhesive portion 1D, according to JIS L1096:2010 8.26.1 Method A (Fragile method), is preferably 6 to 28 cm. 3 / cm 2 sec, more preferably 8-18 cm 3 / cm 2 sec, more preferably 10-14 cm 3 / cm 2 ·sec. As a result, for example, when portions 10D including the non-adherent portions 1D of multiple anti-slip protective sheets 10 are heat-fused together, a certain degree of air permeability at the connecting portion tends to be ensured. It should be noted that the air permeability in portions 10D including the non-adherent portions 1D can be said to correspond to the air permeability before the anti-slip treatment in the embodiments described later.

[0045] Next, the slope protection structure of the embodiment will be described. As shown in Figure 3, the slope protection structure 20 of the embodiment includes an anti-slip protective sheet 10 and a heavy object 13 placed on one surface 1A of the first nonwoven fabric 1 of the anti-slip protective sheet 10. More specifically, in the embodiment shown in Figure 3, the anti-slip protective sheet 10 is placed from the front slope 30A to the back slope 30B of the embankment 30, and the heavy object 13 is placed on both the front slope 30A side and the back slope 30B side of the anti-slip protective sheet 10. Furthermore, Figure 3 shows a cloth bag 11 filled with a filling material 12 as the heavy object 13. Examples of the filling material 12 include solidified soil obtained by adding a cement-based solidifying agent to mud generated by dredging, sand, stones, and soil. The cloth bag 11 preferably has an opening at the top. As a result, after placing the cloth bag 11 on the slope, the filling material 12 is injected into the cloth bag 11 through its opening, allowing the cloth bag 11 to function as a weight. The cloth bag 11 is preferably a so-called concrete mat. The cloth bag 11 is preferably made of woven fabric. For example, if the cloth bag 11 is formed by sewing together multiple pieces of woven fabric, the strength of the cloth bag 11 is improved, and the frictional force between the cloth bag 11 and one surface 1A of the first nonwoven fabric 1 having particles 4P is improved. The weight 13 may also be stone, concrete blocks, concrete slabs, asphalt, metal blocks, metal plates, sand, stones, soil, etc. Although not shown in the figures, the anti-slip protective sheet 10 may be placed on only one of the slopes of the embankment 30, either the front slope 30A or the back slope 30B.

[0046] The slope protection structure 20 preferably has multiple anti-slip protective sheets 10, and the multiple anti-slip protective sheets 10 are preferably connected to each other. This allows the anti-slip protective sheets 10 to be installed on the slope over a wide area.

[0047] The above-mentioned anti-slip protective sheet 10 and slope protection structure 20 can be placed, for example, on the front slope 30A, the back slope 30B, or both slopes of a levee 30 to protect the slope. These can be suitably used, for example, in revetment construction in rivers, coastlines, reclaimed land, etc. [Examples]

[0048] The present invention will be described in more detail below with reference to examples, but the present invention is not limited by the following examples, and can be implemented with modifications within the scope that is consistent with the spirit of the preceding and following descriptions, and all such modifications are included within the technical scope of the present invention.

[0049] The characteristics of the anti-slip protective sheets in Examples 1 and 2 and Comparative Examples 1 to 3, described later, were measured based on the following method.

[0050] [Strength ratio of the connecting part] As an indicator of the adhesive strength of the joints of the anti-slip protective sheets, the strength ratio of the joints was measured by the following method. In the following, one surface of the anti-slip protective sheet to which the resin composition is attached (the anti-slip treated surface) is referred to as the front surface, and the other surface to which the resin composition is not attached (the non-anti-slip treated surface) is referred to as the back surface. In cases where neither surface has been treated with anti-slip, the relative positions of the front and back surfaces are not considered. Furthermore, in the following, in a plan view from the front side of the anti-slip protective sheet, the areas to which the resin composition is not attached are referred to as the attached areas, and the areas to which the resin composition is attached are referred to as the non-attached areas.

[0051] First, a 12.5 cm x 5.0 cm section was cut from the non-adhered area of ​​the obtained anti-slip protective sheet as sample A, and then a 12.5 cm x 5.0 cm section was cut from the adhesive area of ​​the anti-slip protective sheet as sample B. Next, the back surface of sample A and the 5.0 cm x 5.0 cm section of the front surface of sample B were laminated so that they overlapped, and the laminated portion was heat-fused at a temperature of 230°C for 15 seconds to obtain test piece C with a 5.0 cm x 5.0 cm joint. If the anti-slip protective sheet did not have an adhesive area, another sample A was used instead of sample B to obtain test piece C.

[0052] Separately, a 20.0 cm x 5.0 cm section was cut from the non-adhesive area of ​​the anti-slip protective sheet and designated as test piece D. Three test pieces C were prepared for measuring the strength of the joint, and three test pieces D were prepared for measuring the strength of the non-adhesive area. Next, using a tensile testing machine manufactured by Shimadzu Corporation, the test pieces were positioned so that their centers were located in the center of the 10 cm distance between the chucks, with a chuck width of 5 cm and a tensile speed of 50 mm / min. Each test piece was then pulled in the length direction to measure the maximum point strength. The average value of five test results was calculated and rounded to the nearest integer according to rule B (rounding method) of JIS Z 8401 to obtain the strengths of the joint and non-adhesive areas of the anti-slip protective sheet. The obtained values ​​were substituted into the following formula to determine the strength ratio of the joint of the anti-slip protective sheet. In the formula, A represents the strength ratio (%) of the joint of the anti-slip protective sheet, B represents the strength of the joint, and C represents the strength of the non-adhesive area. A = B / C × 100

[0053] [Air permeability] In accordance with JIS L1096:2010 8.26.1 Method A (Fragile method), the air permeability of the anti-slip protective sheet before anti-slip treatment and of each part of the anti-slip protective sheet was measured. Specifically, three 100mm x 100mm test pieces were taken from each of the anti-slip protective sheet before anti-slip treatment, the anti-slip protective sheet, and the joint formed by heat fusion, similar to the adhesive strength test piece C described above. Next, after attaching the test pieces to one end of the cylinder of the testing machine, the intake fan and air vents were adjusted using a regulator so that the inclined barometer showed a pressure of 125 Pa, and the pressure shown by the vertical barometer at that time was measured. From the measured pressure and the type of air vent used, the amount of air (cm³) passing through the test piece was calculated using the conversion table attached to the testing machine. 3 / cm 2 The value of / s was calculated. The average of the three test results was calculated and rounded to an integer according to rule B (rounding method) of JIS Z 8401.

[0054] [Static friction coefficient] The static friction coefficient was measured using a DS-type textile friction coefficient tester manufactured by Kowa Shokai. Specifically, a test piece measuring 7 cm vertically and 5 cm horizontally was taken from the anti-slip protective sheet. Then, the target fabric was the white cloth attached for dye fastness testing as described in JIS L0803:2011 (polyester 8-1, basis weight 70 g / m²). 2 The test specimen was placed on a base to which a pendulum was attached, so that the anti-slip treated surface of the test specimen was in contact with the target fabric. A trolley was then placed on top of the trolley, and the pendulum and trolley were connected by a chain and moved at a speed of 7.5 ± 0.5 cm / min. During this time, the direction of movement of the trolley was kept parallel to the longitudinal direction of the test specimen. The value of the pendulum's tensile force / (98.1 cN + weight of the sample) was calculated and used as the static friction coefficient.

[0055] (Example 1) Using a two-component spunbond spinning machine, 50% by mass of polyethylene terephthalate was used as the core component and 50% by mass of polyethylene as the sheath component. Spinning was performed from a spinneret with a pore diameter of φ0.40 mm at a spinning temperature of 280°C and a single-hole discharge rate of 2.6 g / min. Subsequently, dry air was supplied by an ejector, and the fibers were stretched in one stage and collected on a conveyor below while being opened to obtain a long-fiber web. Next, the obtained long-fiber web was temporarily crimped and then entangled by needle punching. The resulting web had a thickness of 1.35 mm and a basis weight of 300 g / m². 2 Two sheets of spunbond nonwoven fabric with a fiber fineness of 3.3 dtex are prepared, and a waterproof sheet made of spunbond nonwoven fabric composed of polyethylene fibers treated with a silicone-based water-repellent coating is prepared (thickness: 0.25 mm, basis weight: 70 g / m²). 2 One sheet of spunbond nonwoven fabric (with a fiber fineness of 1.9 dtex) was prepared, and the spunbond nonwoven fabric, waterproof sheet, and spunbond nonwoven fabric were laminated in order and heat-pressed using a 200°C heat calender. Next, a laminated sheet was obtained by cutting off both edges of the sheet with a slitter so that the total width was 2.0 m. Then, an anti-slip coating solution was obtained by gradually adding No. 8 silica sand from Tokai Ritec to the acrylic emulsion, mixing until uniform, so that the total amount of the coating solution was 75% by mass of Color&Comfort's acrylic emulsion (Boncoat AN-678A-E) and 25% by mass of Tokai Ritec's No. 8 silica sand. Next, one surface of the laminated sheet was coated with a knife coater to a basis weight of 225 g / m². 2 The coating solution was applied uniformly to achieve the desired result. During this process, at each end of the laminated sheet in the width direction, a 10 cm length area in the width direction was avoided from coating, anticipating that the laminated sheets would be heat-fused together. Next, a drying treatment was performed at 90°C for 10 minutes to obtain an anti-slip protective sheet. The basis weight of the resin composition derived from the coating solution in the obtained anti-slip protective sheet was 130 g / m². 2 That was the case.

[0056] (Example 2) An anti-slip protective sheet was obtained in the same manner as in Example 1, except that the coating solution was applied to the entire surface of one of the laminated sheets.

[0057] (Comparative Example 1) A non-slip protective sheet was obtained in the same manner as in Example 1, except that polyethylene terephthalate was spun using a single-component spunbond spinning machine to produce the spunbond nonwoven fabric.

[0058] (Comparative Example 2) In preparing the spunbond nonwoven fabric, polypropylene was spun using a single-component spunbond spinning machine, and a slip-resistant protective sheet was obtained in the same manner as in Example 1, except that the spinning temperature was 180°C.

[0059] (Comparative Example 3) A laminated sheet was prepared in the same manner as in Example 1, and this was used as an anti-slip protective sheet.

[0060] Table 1 shows the composition and characteristics of each of these anti-slip protective sheets.

[0061] [Table 1]

[0062] As shown in Table 1, the anti-slip protective sheets of Examples 1 and 2 had excellent static friction coefficients because they contained a resin composition with particles and binder resin, and excellent adhesive strength at the connecting parts because they contained a nonwoven fabric with core-sheath fibers in which the melting point of the sheath portion is lower than that of the core portion. [Explanation of Symbols]

[0063] 1 1st nonwoven fabric 1A One surface 1B The other side 1C Adhesion area 1D Non-adhered area 1E One end 1F Other end 1X width direction 1Y length direction 2 Second nonwoven fabric 3 Waterproof sheet 4 Resin composition 4B Binder Resin 4P particles 10 Anti-slip protective sheets 10C Part including the attachment area 10D Part including non-adhered area 11 Bag body 12 Filling 13 Heavy objects 20 Slope protection structures 30 Embankment 30A surface slope 30B Back slope

Claims

1. The invention comprises a first nonwoven fabric and a resin composition attached to one surface of the first nonwoven fabric. The aforementioned resin composition comprises particles and a binder resin. The first nonwoven fabric includes core-sheath fibers having a core and a sheath, The anti-slip protective sheet has a lower melting point for the resin contained in the sheath than for the resin contained in the core.

2. Furthermore, it has a second nonwoven fabric and a waterproof sheet, The second nonwoven fabric, the waterproof sheet, and the first nonwoven fabric are laminated in order. The other surface of the first nonwoven fabric faces the waterproof sheet, The second nonwoven fabric contains core-sheath fibers having a core and a sheath, The anti-slip protective sheet according to claim 1, wherein the melting point of the resin contained in the sheath portion is lower than the melting point of the resin contained in the core portion.

3. The air permeability of the aforementioned anti-slip protective sheet according to JIS L1096:2010 8.26.1 Method A (Fragile method) is 3 to 25 cm. ３ / cm ２ sec, The aforementioned particles are inorganic particles, The anti-slip protective sheet according to claim 1 or 2, wherein the content of the inorganic particles in 100% by mass of the resin composition is 40 to 95% by mass.

4. The first nonwoven fabric has a length direction and a width direction, One surface of the first nonwoven fabric has at least one non-adherent portion, which is a portion to which the resin composition is not attached. The anti-slip protective sheet according to claim 1 or 2, wherein at least one of the non-adhering portions is located at one end, the other end, or both ends in the width direction.

5. The anti-slip protective sheet according to claim 1 or 2, wherein the static friction coefficient between one surface of the first nonwoven fabric to which the resin composition is attached and the attached white cloth (polyester 8-1) for color fastness testing described in JIS L0803:2011 is 0.60 to 0.

90.

6. The waterproof sheet is a nonwoven fabric, as described in claim 2.

7. The anti-slip protective sheet according to claim 1 or 2, A slope protection structure having a heavy object placed on one surface of the first nonwoven fabric of the anti-slip protective sheet.

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