Weed-proof sheet and use thereof

Abstract

To provide a weed-proof sheet excellent in lightweight properties and capable of suppressing temperature rise in construction.SOLUTION: The weed-proof sheet 1 for suppressing the growth of plants by being laid on the ground includes a first asphalt waterproof layer 3 which is disposed on the side in contact with the ground and is formed of a first asphalt composition containing first asphalt, and a second asphalt waterproof layer 4 which is laminated on the first asphalt waterproof layer 3. And an asphalt-impregnated fiber layer 4 formed of a fiber structure containing a third asphalt, a second asphalt waterproof layer 5 laminated on the asphalt-impregnated fiber layer 4 and formed of a second asphalt composition containing a second asphalt, and a heat shielding layer 6 laminated on the second asphalt waterproof layer 5 and containing porous inorganic particles having an average pore diameter of 50 μm or less. A resin layer 2 may be laminated on the surface of the first asphalt waterproof layer 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a weed control sheet for suppressing the growth of plants such as weeds on the ground, and to uses thereof. [Background technology]

[0002] Laying weed control sheets on the ground is known as a method for suppressing the growth of weeds and other plants from the ground on roads (roadways, sidewalks, etc.), railways, parks, farms, afforestation areas, or their surrounding areas, riverbeds, etc. For example, Japanese Patent Laid-Open Publication No. 2002-272348 (Patent Document 1) discloses a weed control sheet with shading properties that prevents grass growth, which is a weed control sheet comprising at least three laminated layers: a surface layer selected from inorganic particles and synthetic resins containing inorganic particles, a modified asphalt layer, and a base layer, wherein the base layer is a substrate selected from woven fabric, knitted fabric, and nonwoven fabric, and the base material is made of fibers selected from core-sheath fibers having a melting point of 200°C or higher and the sheath portion is made of resin having a melting point of 200°C or higher. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-272348 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the weed control sheet of Patent Document 1 uses mineral particles as inorganic particles, which makes it heavy and difficult to apply. Furthermore, weed control sheets are installed in outdoor environments where plants can easily grow, and are therefore exposed to intense sunlight and prone to high temperatures. If the weed control sheet becomes hot during installation, not only will the temperature at the work site rise, but the weed control sheet, which is made of asphalt, will become sticky and difficult to handle. Furthermore, if the weed control sheet becomes sticky, it will easily contaminate the work environment, and the weed control sheet itself will be easily damaged during work, and footprints and other marks will be left on the surface of the sheet, reducing its aesthetic appeal.

[0005] Therefore, an object of the present invention is to provide a weed control sheet that is lightweight and can suppress temperature rise during installation, and uses thereof.

[0006] Another object of the present invention is to provide a weed control sheet that is less sticky and therefore easier to handle, that prevents deterioration of the working environment, and that does not impair the aesthetic appearance, and uses thereof. [Means for solving the problem]

[0007] As a result of extensive research into achieving the above-mentioned objectives, the inventors discovered that by providing a weed control sheet with a heat shield layer containing porous inorganic particles with an average pore size of 50 μm or less, it is possible to improve the sheet's light weight and also to suppress temperature increases during installation, and thus completed the present invention.

[0008] That is, the present invention includes the following aspects.

[0009] Aspect [1]: A weed control sheet that can suppress plant growth by being laid on the ground and has a heat-shielding layer containing porous inorganic particles with an average pore size of 50 μm or less.

[0010] Mode [2]: A first asphalt waterproofing layer disposed on the side in contact with the ground and formed of a first asphalt composition containing a first asphalt; an asphalt-impregnated fiber layer laminated on the first asphalt waterproof layer and formed of a fiber structure containing a third asphalt; A second asphalt waterproofing layer is laminated on the asphalt-impregnated fiber layer and is formed of a second asphalt composition containing a second asphalt; The weed control sheet according to aspect [1], further comprising the heat shield layer laminated on the second asphalt waterproofing layer.

[0011] Aspect [3]: The bulk density of the porous inorganic particles is 1.4 g / cm 3 The weed control sheet according to aspect [1] or [2], which is as follows:

[0012] Aspect [4]: ​​The bulk density of the porous inorganic particles is 0.5 to 1.2 g / cm 3 The weed control sheet according to any one of the above aspects [1] to [3], wherein

[0013] Aspect [5]: The weed control sheet according to any one of Aspects [1] to [4], wherein the mercury intrusion amount of the porous inorganic particles is 0.1 cc / g or more.

[0014] Aspect [6]: The weed control sheet according to any one of Aspects [1] to [5], wherein the porous inorganic particles have an average particle size of 0.2 to 10 mm.

[0015] Aspect [7]: The porous inorganic particles have a basis weight of 1300 g / m 2 The weed control sheet according to any one of the above aspects [1] to [6], which is as follows:

[0016] Aspect [8]: The weed control sheet according to any one of Aspects [1] to [7], wherein the porous inorganic particles are glass foam.

[0017] Aspect [9]: The weed control sheet according to any one of Aspects [2] to [8], wherein the second asphalt composition has a penetration of 100 or less.

[0018] Aspect

[10] : The weed control sheet according to any one of Aspects [2] to [9], wherein the second asphalt composition contains 1 to 100 parts by mass of a second filler per 100 parts by mass of the second asphalt.

[0019] Aspect

[11] : A weed control sheet according to any one of Aspects [2] to

[10] , in which a resin layer is laminated on the surface of the first asphalt waterproofing layer.

[0020] Aspect

[12] : A first asphalt waterproofing layer disposed on the side in contact with the ground and formed of a first asphalt composition containing a first asphalt; an asphalt-impregnated fiber layer laminated on the first asphalt waterproof layer and formed of a fiber structure containing a third asphalt; A second asphalt waterproofing layer is laminated on the asphalt-impregnated fiber layer and is formed of a second asphalt composition containing a second asphalt; A method for improving the workability of a weed control sheet by combining it with a heat shield layer that is layered on top of the second asphalt waterproofing layer and contains porous inorganic particles with an average pore size of 50 μm or less. [Effects of the Invention]

[0021] In this invention, the weed control sheet has a heat-shielding layer containing porous inorganic particles with an average pore size of 50 μm or less, which improves its lightness and suppresses temperature increases during construction. Furthermore, by laminating an asphalt-impregnated fiber layer and a second asphalt waterproofing layer in sequence on the first asphalt waterproofing layer that comes into contact with the ground, and then laminating a heat-shielding layer containing porous inorganic particles on top of this second asphalt waterproofing layer, not only does the weed control sheet become less sticky, it is easier to handle, and construction is therefore easier. Furthermore, the working environment is kept from deteriorating, and the aesthetic appearance is not impaired. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a weed control sheet of the present invention. [Figure 2] FIG. 2 is a scanning electron microscope photograph (500x magnification) of glass foam B used in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0023] [Weed control sheet] The weed control sheet of the present invention has a heat shield layer containing porous inorganic particles with an average pore size of 50 μm or less, which improves workability.Preferably, the weed control sheet of the present invention includes a waterproof layer containing asphalt, and the heat shield layer is formed on the surface opposite to the side that comes into contact with the ground.

[0024] The weed control sheet of the present invention will now be described with reference to the drawings, in which: Figure 1 is a schematic cross-sectional view showing an example of the weed control sheet of the present invention.

[0025] The weed control sheet 1 shown in Figure 1 is formed from a resin layer 2 on the side that comes into contact with the ground, a first asphalt waterproofing layer 3 laminated on this resin layer 2, an asphalt-impregnated fiber layer 4 laminated on this first asphalt waterproofing layer 3, a second asphalt waterproofing layer 5 laminated on this asphalt-impregnated fiber layer 4, and a heat-shielding layer 6 laminated on this second asphalt waterproofing layer 5, and the heat-shielding layer 6 contains porous inorganic particles with an average pore size of 50 µm or less, thereby improving its light weight. The surface shape of the weed control sheet 1 may be a quadrilateral shape such as a square or rectangle, but a long shape (particularly a long rectangular shape) is preferred from the standpoint of workability and other factors.

[0026] The weed control sheet 1 has a resin layer 2 laminated on the surface of the first asphalt waterproof layer 3, but it may also have no resin layer 2. If the weed control sheet has a resin layer, it can be easier to handle.

[0027] The weed control sheet of the present invention is usually laid in multiple sheets on the ground to suppress plant growth. Furthermore, weed control sheet installation is carried out in outdoor environments exposed to sunlight, and in recent years, due to factors such as the aging population and climate change, excellent workability is required. In particular, temperatures are on the rise due to the effects of global warming, and weed control sheets become sticky and easily damaged when used outdoors. Therefore, it is important to reduce stickiness and improve handleability. Furthermore, with the aging population, lightweight properties are also important in order to avoid heavy labor. In contrast, the present invention forms a heat-shielding layer containing porous microparticles with an average pore size of 50 μm or less on the surface of the second asphalt waterproofing layer, and prepares the second asphalt waterproofing layer from a specific asphalt composition, thereby improving handleability (or thermal insulation) in addition to lightweight properties.

[0028] (heat shielding layer) The heat-shielding layer contains porous inorganic particles with an average pore size of 50 μm or less, which ensures light weight, improves heat-shielding properties (insulation), and reduces stickiness of the weed control sheet, thereby improving workability.

[0029] Examples of inorganic materials constituting the porous inorganic particles include simple metals (e.g., iron, copper, tin, zinc, nickel, stainless steel, etc.), inorganic oxides or metal oxides [e.g., beryllium oxide, silicon oxide or silica, aluminum oxide or alumina, titania, zirconia, magnesia, manganese oxide, iron oxide, ferric oxide, iron tetraoxide, zinc oxide, zinc oxide, copper oxide, tin oxide, antimony oxide, cerium oxide, tin-doped indium oxide (ITO), etc.], nitrogen compounds (e.g., boron nitride, aluminum nitride, silicon nitride, carbon nitride, titanium nitride, etc.), carbon compounds (e.g., silicon carbide, fluorine carbide, boron carbide, titanium carbide, tungsten carbide, etc.), gold, metal salts (e.g., metal carbonates such as calcium carbonate, calcium bicarbonate, barium carbonate, and magnesium carbonate; sulfates such as barium sulfate, calcium sulfate, aluminum sulfate, and calcium sulfite; metal hydroxides such as magnesium hydroxide), minerals (e.g., steelmaking slag, slate chips, talc, mica, zeolite, ferrite, tourmaline, diatomaceous earth, silica sand, calcined silica earth, activated clay, shirasu, kaolin, pyrophyllite, sericite, bentonite, smectite, montmorillonite, clay, red iron oxide, quartz, and wollastonite), glasses (e.g., soda-lime glass, lead glass, borosilicate glass, and silica glass), and silicon.

[0030] These inorganic materials can be used alone or in combination. Among these, minerals and glasses are preferred, with glasses such as soda-lime glass being particularly preferred due to their excellent recyclability. As porous inorganic particles, porous mineral particles such as pumice powder and porous glass particles such as soda-lime glass are preferred, with porous glass particles being particularly preferred. Porous glass particles are lightweight and have higher thermal conductivity than minerals, but their porous structure can improve thermal insulation and light blocking properties. In particular, they exhibit thermal insulation properties comparable to those of porous mineral particles, which have low thermal conductivity.

[0031] The porous glass particles may be glass particles having a porous structure (interconnected hollow or open cell shape), but may also be glass foam.

[0032] Porous inorganic particles (especially porous glass particles such as glass foam) have a low bulk density, e.g., 1.4 g / cm 3 It may be less than 1.2 g / cm 3 or less (e.g., 0.5 to 1.2 g / cm 3 ), more preferably 1.1 g / cm 3 Less than 1 g / cm, more preferably 3 Below 0.8 g / cm, most preferably 0.8 g / cm 3 Specifically, it is 0.1 to 1.1 g / cm 3 , preferably 0.3 to 1 g / cm 3 , and more preferably 0.5 to 0.9 g / cm 3 , more preferably 0.6 to 0.8 g / cm 3 , and most preferably 0.65 to 0.75 g / cm 3 If the bulk density is too high, there is a risk that the lightness will decrease.

[0033] In this specification and claims, the bulk specific gravity of the porous inorganic particles can be measured in accordance with JIS Z 2504:2020 using a funnel with an orifice diameter of 5.0 mm and a funnel angle of 60 degrees.

[0034] The specific surface area of ​​the porous inorganic particles (particularly, porous glass particles) is, for example, 0.35 m 2 / g or more, and from the viewpoint of improving the handling property in addition to the light weight, it is preferably 0.5 m 2 / g or more, more preferably 1m 2 / g or more, more preferably 2m 2 / g or more, specifically 0.35 to 10m 2 / g, preferably 0.5 to 8m 2 / g, more preferably 1 to 5m 2 / g, more preferably 2 to 4 m 2 / g, most preferably 2.5 to 3.5 m 2If the specific surface area is too small, there is a risk that the lightness and ease of handling will decrease.

[0035] In this specification and claims, the specific surface area of ​​the porous inorganic particles can be measured using a specific surface area meter in accordance with JIS Z 8830 "Method for measuring the specific surface area of ​​powders (solids) by gas adsorption."

[0036] The mercury intrusion amount of the porous inorganic particles (particularly, porous glass particles) may be, for example, 0.1 cc / g or more, preferably 0.13 cc / g or more, more preferably 0.15 cc / g or more, and more preferably 0.17 cc / g or more, and specifically 0.1 to 1 cc / g, preferably 0.12 to 0.8 cc / g, more preferably 0.13 to 0.5 cc / g, more preferably 0.15 to 0.3 cc / g, and most preferably 0.17 to 0.25 cc / g. If the mercury intrusion amount is too small, there is a risk that the lightness and handleability will decrease.

[0037] The average pore size of the porous inorganic particles (particularly porous glass particles) is 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less, and even more preferably 10 μm or less, specifically 1 to 50 μm, preferably 2 to 40 μm, even more preferably 3 to 30 μm, more preferably 5 to 10 μm, and most preferably 6 to 8 μm, in order to improve not only lightness but also handleability. If the average pore size is too large, it is difficult to achieve both lightness and handleability.

[0038] In this specification and claims, the mercury intrusion amount and average pore size of porous inorganic particles can be measured using a mercury intrusion porosimeter in accordance with JIS R 1655 "Test method for pore size distribution of molded fine ceramics by mercury intrusion method," and in detail, can be measured by the method described in the examples below.

[0039] The shape of the porous inorganic particles (particularly, porous glass particles) is not particularly limited as long as it is granular, and examples thereof include spherical or approximately spherical, ellipsoidal or rod-like, polyhedral (e.g., cubic, rectangular, tetrahedral (pyramidal)), flat (plate-like, scaly, or thin), and irregular shapes. Of these, irregularly shaped granular shapes are commonly used.

[0040] The porous inorganic particles (particularly porous glass particles) may have an average particle size of 0.2 to 10 mm, preferably 0.5 to 8 mm, further preferably 1 to 5 mm, even more preferably 1.5 to 3.5 mm, and most preferably 2 to 3 mm in order to improve not only lightness but also handleability. If the average particle size is too small, the heat-shielding effect and light-shielding effect may be reduced, and if it is too large, the lightness and handleability may be reduced.

[0041] The minimum particle size of the porous inorganic particles (particularly, porous glass particles) may be 1 μm or more, preferably 10 μm or more, and more preferably 20 μm or more, and the maximum particle size may be 15 mm or less, preferably 10 mm or less, and more preferably 5 mm or less.

[0042] In this specification and claims, the average particle size, minimum particle size, and maximum particle size of porous inorganic particles can be measured based on the mass-based particle size distribution after sieving, and in detail, can be measured in accordance with Chapter 4, Soil Particle Size Testing, of "Soil Testing: Fundamentals and Guidelines" published by the Geotechnical Society of Japan.

[0043] In the present invention, the heat shield layer may further contain particles other than the porous inorganic particles, as long as the effects of the present invention are not impaired.

[0044] The other particles may be either non-porous inorganic particles or organic particles, such as silicone-based resin particles, cross-linked polyolefin-based resin particles, cross-linked polymethyl methacrylate-based resin particles, melamine-based resin particles, or cross-linked polystyrene-based resin particles, but non-porous inorganic particles are preferred in terms of heat resistance and the like.

[0045] Examples of inorganic materials constituting non-porous inorganic particles include the inorganic materials exemplified as inorganic materials constituting the porous inorganic particles. The inorganic materials can be used alone or in combination of two or more. Among the inorganic materials, minerals and glasses are preferred. Preferred non-porous inorganic particles are mineral particles such as silica sand and glass particles such as waste glass.

[0046] The shape of the other particles (particularly non-porous inorganic particles) is not particularly limited as long as it is granular, and examples thereof include spherical or approximately spherical, ellipsoidal or rod-like, polyhedral (e.g., cubic, rectangular, tetrahedral (pyramidal)), flat (plate-like, scaly, or thin), and irregular shapes. Of these, irregularly shaped granular shapes are commonly used.

[0047] The average particle size of the other particles (particularly non-porous inorganic particles) is, for example, 10 to 1000 μm, preferably 100 to 800 μm, and more preferably 200 to 500 μm.

[0048] The proportion of the porous inorganic particles may be 10% by mass or more, preferably 50% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and most preferably 100% by mass of the total amount of the porous inorganic particles and other particles (they may be formed solely of porous inorganic particles).

[0049] The heat shield layer may further contain other components in addition to the porous inorganic particles, as long as the effects of the present invention are not impaired.

[0050] Other components include organic components that coat the exposed surfaces of the porous inorganic particles and other particles, and an asphalt composition in which a second asphalt waterproofing layer has seeped onto the surfaces of the porous inorganic particles or other particles (the second asphalt composition described below).

[0051] Examples of the organic component include polyolefins, vinyl polymers (e.g., polyvinyl chloride, acrylic resins, polyvinyl acetate, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, ethylene-acrylic acid copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, etc.), polyamides, polyesters, synthetic rubbers or elastomers (e.g., polybutadiene, polyisoprene, styrene-butadiene copolymers, etc.), natural rubbers, tackifiers (e.g., terpene resins, rosin resins such as natural rosin and modified rosin, petroleum resins, modified olefin polymers, etc.), and oils and fats (e.g., naphthenic raw oils, etc.). These organic components can be used alone or in combination. Of the organic components, vinyl polymers are preferred, and (meth)acrylic polymers are preferred.

[0052] Examples of the (meth)acrylic polymer include poly(meth)acrylic acid or a salt thereof, methyl methacrylate-(meth)acrylic acid copolymer, acrylic acid-polyvinyl alcohol copolymer (saponified acrylic acid-vinyl acetate copolymer), styrene-(meth)acrylic acid copolymer, and styrene-(meth)acrylic acid C 1-10 Alkyl ester copolymer, vinyl acetate-(meth)acrylic acid copolymer, vinyl acetate-(meth)acrylic acid C 1-10 Examples of (meth)acrylic polymers include alkyl ester copolymers. These (meth)acrylic polymers are available in the form of emulsions, making them easy to handle. These (meth)acrylic polymers can be used alone or in combination of two or more. Among these, copolymers with styrene, such as styrene-(meth)acrylic acid copolymers, are preferred because of their excellent mechanical properties.

[0053] In the heat shield layer, the weight of the porous inorganic particles is 1300 g / m 2 It may be 10 to 1300 g / m or less, and from the viewpoint of improving the handling property in addition to the light weight, for example, 10 to 1300 g / m 2 , preferably 100 to 1250 g / m 2 , and more preferably 500 to 1200 g / m 2, more preferably 700 to 1150 g / m 2 , and most preferably 900 to 1100 g / m 2 If the weight per unit area is too high, there is a risk that the lightness will decrease, and if it is too low, there is a risk that the handling properties will decrease.

[0054] The average thickness of the heat shield layer may be 10 mm or less, for example, 0.2 to 10 mm, preferably 0.3 to 8 mm, further preferably 0.5 to 5 mm, even more preferably 0.8 to 3 mm, and most preferably 1 to 2 mm. If the thickness of the heat shield layer is too thin, the heat shielding effect may decrease, and if it is too thick, the lightness may decrease.

[0055] In this specification and claims, the average thickness of the thermal barrier layer is determined by measuring the thickness at any 10 locations and calculating the average value.

[0056] (Second asphalt waterproof layer) The second asphalt waterproofing layer is formed from a second asphalt composition and has waterproof properties. In the present invention, by laminating the heat shield layer on the second asphalt waterproofing layer, not only can the weight of the weed control sheet be improved, but stickiness of the weed control sheet can also be reduced, improving handleability.

[0057] The second asphalt composition contains a second asphalt. Examples of the second asphalt include natural asphalt (lake asphalt, rock asphalt, oil sand, asphaltite, etc.) and petroleum asphalt (straight asphalt, blown asphalt, etc.). These asphalts can be used alone or in combination. Of these, petroleum asphalts such as straight asphalt are preferred.

[0058] The penetration (1 / 10 mm) of the second asphalt is not particularly limited, but can be selected from a range of about 0 to 300 in a method (25°C) in accordance with JIS K 2207-1996, for example, 20 to 280, preferably 30 to 250, further preferably 40 to 200, more preferably 50 to 100, and most preferably 60 to 80. If the penetration is too small, it may be difficult to form a uniform layer, and conversely, if it is too large, handling may be impaired.

[0059] The softening point of the second asphalt can be selected from a range of about 0 to 150° C. in a method conforming to JIS K 2207-1996, for example, 10 to 100° C., preferably 20 to 80° C., further preferably 30 to 60° C., and even more preferably 40 to 50° C. If the softening point is too low, it may be difficult to form a uniform layer, and if it is too high, handling may be impaired.

[0060] The proportion of the second asphalt in the second asphalt composition may be 30% by mass or more (particularly 50% by mass or more), for example, 30 to 95% by mass, preferably 40 to 90% by mass, further preferably 50 to 88% by mass, more preferably 60 to 85% by mass, and most preferably 70 to 80% by mass. If the proportion of the second asphalt is too low, there is a risk that waterproofing properties will decrease.

[0061] The second asphalt composition preferably further contains a second filler, which can reduce stickiness of the weed control sheet and improve handleability. Second fillers include inorganic fillers (inorganic fillers) and organic fillers (organic fillers).

[0062] Examples of inorganic fillers include metal particles (powders) such as iron, copper, tin, zinc, nickel, and stainless steel; metal oxide particles such as iron oxide, ferric oxide, iron tetraoxide, ferrite, tin oxide, zinc oxide, zinc oxide, copper oxide, and aluminum oxide; metal salt particles such as barium sulfate, calcium sulfate, aluminum sulfate, calcium sulfite, calcium carbonate, calcium bicarbonate, barium carbonate, and magnesium hydroxide; mineral particles such as steelmaking slag, slate chips, mica, clay, talc, wollastonite, diatomaceous earth, silica sand, pumice powder, silica balloons, and shirasu balloons; glass particles such as waste glass, glass foam, and glass balloons; and inorganic fibers such as glass fiber and carbon fiber. These inorganic fillers can be used alone or in combination.

[0063] Examples of organic fillers include wood flour, pulp, natural fibers (cotton, hemp, etc.), recycled fibers (rayon, etc.), cross-linked resin particles (cross-linked polyethylene particles, cross-linked polystyrene particles, cross-linked acrylic particles, etc.), synthetic fibers (polyester fibers, polyamide fibers, etc.), etc. These organic fillers can be used alone or in combination of two or more.

[0064] These fillers can be used alone or in combination of two or more. Among these fillers, inorganic fillers are preferred, metal salt particles are more preferred, and metal carbonate particles such as calcium carbonate are even more preferred, from the viewpoint of easily improving lightness and handleability.

[0065] The shape of the second filler (particularly, inorganic filler) is not particularly limited as long as it is granular, and examples thereof include spherical or approximately spherical, ellipsoidal or rod-like, polyhedral (e.g., cubic, rectangular, tetrahedral (pyramidal)), flat (plate-like, scaly, or thin), and irregular shapes. Of these, irregularly shaped granular shapes are commonly used.

[0066] The second filler (particularly, inorganic filler) has an average particle size of, for example, 10 to 500 μm, preferably 20 to 300 μm, further preferably 30 to 200 μm, even more preferably 50 to 150 μm, and most preferably 100 to 150 μm. If the average particle size is too small, the effect of improving handleability may be reduced, and if it is too large, waterproofness may be reduced.

[0067] The second filler (particularly, inorganic filler) may have a maximum particle size of 5 mm or less, preferably 3 mm or less, and more preferably 1 mm or less.

[0068] In this specification and claims, the average particle size and maximum particle size of the filler can be measured on a volume basis using a laser diffraction / scattering particle size distribution analyzer, and the average particle size is determined based on the median particle size (D 50 ) means

[0069] The bulk density of the second filler (especially inorganic filler) is 10 g / cm 3 or less, for example, 1 to 10 g / cm 3 , preferably 1.2 to 5 g / cm 3 , and more preferably 1.5 to 4 g / cm 3 , more preferably 2 to 3.5 g / cm 3 , and most preferably 2.5 to 3 g / cm 3 If the bulk density of the filler is too high, there is a risk that the lightweight property will decrease.

[0070] The proportion of the second filler is, for example, 1 to 100 parts by mass, preferably 3 to 50 parts by mass, further preferably 5 to 40 parts by mass, even more preferably 8 to 30 parts by mass, and most preferably 10 to 20 parts by mass, per 100 parts by mass of the second asphalt. If the proportion of the second filler is too low, the effect of improving handleability may be reduced, and conversely, if it is too high, waterproofing may be reduced.

[0071] The second asphalt composition may further contain a second organic modifier, which can improve the bonding strength with the thermal barrier layer.

[0072] Examples of the second organic modifier include polyolefins, vinyl polymers (e.g., polyvinyl chloride, acrylic resins, polyvinyl acetate, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, ethylene-acrylic acid copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, etc.), polyamides, polyesters, synthetic rubbers or elastomers (e.g., polybutadiene, polyisoprene, styrene-butadiene copolymers, etc.), natural rubbers, tackifiers (e.g., terpene resins, rosin resins such as natural rosin and modified rosin, petroleum resins, modified olefin polymers, etc.), and oils and fats (e.g., naphthenic raw oils, etc.). These organic modifiers can be used alone or in combination of two or more.

[0073] Of these organic modifiers, thermoplastic elastomers, tackifiers, and oils and fats are preferred, and styrene-diene copolymers such as styrene-butadiene-styrene block copolymers are particularly preferred.

[0074] The proportion of the second organic modifier is, for example, 1 to 100 parts by mass, preferably 3 to 50 parts by mass, further preferably 5 to 40 parts by mass, even more preferably 10 to 30 parts by mass, and most preferably 15 to 25 parts by mass, relative to 100 parts by mass of the second asphalt. If the proportion of the organic modifier is too low, the effect of improving bonding strength may be reduced, and if it is too high, waterproofing may be reduced.

[0075] The second asphalt composition may further contain conventional additives. Examples of additives include stabilizers (heat stabilizers such as copper compounds, UV absorbers, light stabilizers, antioxidants, etc.), thickeners, leveling agents, antifoaming agents, flame retardants, plasticizers, antistatic agents, colorants, surfactants, dispersants, lubricants, crystallization rate retarders, glidants, antibacterial agents, plant repellents (root control agents), insecticides (termite repellents, mite repellents, etc.), preservatives (mold inhibitors, etc.), matting agents, heat storage agents, fragrances, fluorescent brighteners, and wetting agents. These additives can be used alone or in combination. The total proportion of the additives in the second asphalt composition is 50% by mass or less, preferably 0.01 to 30% by mass, and more preferably 0.1 to 10% by mass.

[0076] The penetration (1 / 10 mm) of the second asphalt composition is not particularly limited, but can be selected from a range of about 0 to 300 in a method (25°C) in accordance with JIS K 2207-1996, and from the viewpoint of improving handleability, it may be 100 or less, for example, 1 to 100, preferably 5 to 80, further preferably 10 to 70, more preferably 20 to 50, and most preferably 30 to 40. If the penetration is too small, it may be difficult to form a uniform layer, and conversely, if it is too large, handleability may be reduced.

[0077] The average thickness of the second asphalt waterproofing layer may be 2.0 mm or less, for example, 0.1 to 1.9 mm, preferably 0.2 to 1.8 mm, further preferably 0.3 to 1.7 mm, even more preferably 0.4 to 1.6 mm, and most preferably 0.5 to 1.5 mm. If the average thickness of the second asphalt waterproofing layer is too large, there is a risk that the lightweight properties will decrease.

[0078] (Asphalt-impregnated fiber layer) The asphalt-impregnated fibrous layer is formed of a fibrous structure containing asphalt (that is, a combination of a fibrous structure and a third asphalt contained within the fibrous structure).

[0079] The fiber structure includes woven fabric, knitted fabric, nonwoven fabric, net, paper, etc. The fiber structure may be a composite (laminate) of these.

[0080] Examples of fibers constituting the fiber structure include natural fibers (cellulose fibers such as cotton and hemp), regenerated fibers (rayon, etc.), semi-synthetic fibers (cellulose ester fibers, etc.), synthetic fibers (polyolefin fibers (polyethylene fibers, polypropylene fibers, etc.), styrene fibers, polytetrafluoroethylene fibers, acrylic fibers, vinyl alcohol fibers (ethylene vinyl alcohol fibers, etc.), polyester fibers (polyalkylene-arylate fibers such as polyethylene terephthalate and polyethylene naphthalate, wholly aromatic polyester fibers such as liquid crystal polyester fibers, etc.), polyamide fibers (aliphatic polyamide fibers such as polyamide 6 and polyamide 66, wholly aromatic polyamide fibers such as aramid fibers, etc.), polyurethane fibers, and inorganic fibers (carbon fibers, glass fibers, etc.). The synthetic fibers may also be composite fibers made by combining different resin components. These fibers can be used alone or in combination of two or more. Among these fibers, synthetic fibers such as polyolefin fibers and polyester fibers, and inorganic fibers are commonly used, but poly-C fibers such as polyethylene terephthalate fibers are preferred in terms of UV resistance and other properties. 2-4 Alkylene-C 6-12 Arylate fibers are preferred.

[0081] The fiber structure includes woven fabric, knitted fabric, nonwoven fabric, net, paper, etc. The fiber structure may be a composite (laminate) of these. Among these, nonwoven fabric is preferred from the viewpoint of mechanical properties, etc.

[0082] The cross-sectional shape of the fibers constituting the fiber structure (cross-sectional shape perpendicular to the length direction of the fibers) is not limited to common solid cross-sectional shapes such as a round cross-section or an irregular cross-section [flat, elliptical, polygonal, 3-14 lobes, T-shaped, H-shaped, V-shaped, dogbone (I-shaped), etc.], and may be a hollow cross-sectional shape, but is usually a round cross-section.

[0083] The average fineness of the fibers may be, for example, 0.1 to 20 dtex, preferably 0.3 to 10 dtex, and more preferably 0.5 to 5 dtex. If the fineness is too small, the mechanical properties may be reduced, and if it is too large, the flexibility may be reduced.

[0084] The fibers may be short fibers, but long fibers are preferred because they can improve the mechanical properties of the fiber layer and can inhibit plants from growing through the weed control sheet from the ground.

[0085] The average fiber length of the long fibers may exceed 150 mm, for example, 200 mm or more, preferably 500 mm or more, more preferably 1000 mm or more, or may be infinite. Long-fiber nonwoven fabrics can be produced by conventional methods, such as direct spinning methods such as the spunbond method, meltblowing method, and flash spinning method. Of these, nonwoven fabrics obtained by the spunbond method are widely used from the standpoint of economy and other factors.

[0086] The apparent density of the fiber structure (especially nonwoven fabrics such as long fiber nonwoven fabrics) is, for example, 0.05 to 0.2 g / cm 3 , preferably 0.07 to 0.18 g / cm 3 , and more preferably 0.1 to 0.15 g / cm 3 , more preferably 0.11 to 0.14 g / cm 3 If the density is too high, flexibility may decrease, and if the density is too low, weed prevention properties and mechanical properties may decrease.

[0087] The basis weight of the fiber structure (especially nonwoven fabrics such as long fiber nonwoven fabrics) is 10 to 1000 g / m 2 You can choose from a range of thicknesses, but 50g / m 2 or more (especially 90g / m 2 or more), and more preferably 100 to 300 g / m 2 , more preferably 110 to 200 g / m 2 , and most preferably 130 to 170 g / m 2 If the basis weight is too large, there is a risk that the lightness will decrease, and if it is too small, there is a risk that the weed prevention properties and mechanical properties will decrease.

[0088] Examples of asphalt (third asphalt) include the asphalts exemplified as the second asphalt. The asphalts can be used alone or in combination of two or more. Among the asphalts, petroleum asphalts such as waterproofing asphalt type 3 and blown asphalt are preferred in terms of strength, such as penetration resistance.

[0089] The penetration (1 / 10 mm) of the third asphalt is not particularly limited, but can be selected from a range of about 0 to 300 in a method (25°C) in accordance with JIS K 2207-1996, and is, for example, 10 to 280, preferably 10 to 200, further preferably 10 to 150, even more preferably 10 to 100, and most preferably 15 to 30. If the penetration is too small, it may be difficult to uniformly penetrate the fiber structure.

[0090] The softening point of the third asphalt can be selected from a range of about 50 to 200° C. in accordance with JIS K 2207-1996, and is, for example, 70 to 180° C., preferably 80 to 150° C., and more preferably 100 to 120° C. If the softening point is too low, it may be difficult to uniformly penetrate the fiber structure, and if it is too high, handling may be impaired.

[0091] The proportion of the third asphalt relative to 100 parts by mass of the fiber structure is, for example, 10 to 1000 parts by mass, preferably 20 to 500 parts by mass, further preferably 30 to 200 parts by mass, even more preferably 50 to 150 parts by mass, and most preferably 80 to 120 parts by mass. If the proportion of the third asphalt is too low, there is a risk that waterproofing will decrease, and conversely, if it is too high, there is a risk that it will be difficult to uniformly penetrate the fiber structure.

[0092] The asphalt-impregnated fibrous layer may further contain other components such as fillers, organic modifiers, and conventional additives. Examples of fillers and organic modifiers include the organic modifiers and fillers exemplified in the section on the second asphalt waterproofing layer. The fillers can be used alone or in combination of two or more. The organic modifiers can be used alone or in combination of two or more. Examples of additives include the additives exemplified in the section on the asphalt waterproofing layer. The additives can be used alone or in combination of two or more. The total proportion of these other components in the asphalt-impregnated fibrous layer is 50% by mass or less, preferably 0.01 to 30% by mass, and more preferably 0.1 to 10% by mass.

[0093] The average thickness of the asphalt-impregnated fibrous layer may be 2 mm or less, for example, 0.1 to 2 mm, preferably 0.1 to 1.5 mm, further preferably 0.3 to 1.4 mm, even more preferably 0.5 to 1.4 mm, and most preferably 0.6 to 1.3 mm. If the average thickness of the asphalt-impregnated fibrous layer is too large, there is a risk that workability will decrease.

[0094] (First asphalt waterproof layer) The first asphalt waterproof layer is formed from a first asphalt composition and has waterproof properties.

[0095] The first asphalt composition includes a first asphalt. Examples of the first asphalt include the asphalts exemplified as the second asphalt. The asphalts can be used alone or in combination. Among the asphalts, petroleum asphalts such as straight asphalt are preferred.

[0096] The penetration (1 / 10 mm) of the first asphalt is not particularly limited, but can be selected from a range of about 0 to 300 in a method (25°C) in accordance with JIS K 2207-1996, for example, 20 to 280, preferably 30 to 250, further preferably 40 to 200, more preferably 50 to 100, and most preferably 60 to 80. If the penetration is too small, it may be difficult to form a uniform layer, and conversely, if it is too large, handling may be impaired.

[0097] The softening point of the first asphalt can be selected from a range of about 0 to 150° C. in a method conforming to JIS K 2207-1996, and is, for example, 10 to 100° C., preferably 20 to 80° C., further preferably 30 to 60° C., and even more preferably 40 to 50° C. If the softening point is too low, it may be difficult to form a uniform layer, and if it is too high, handling may be impaired.

[0098] The proportion of the first asphalt in the first asphalt composition may be 30% by mass or more (particularly 50% by mass or more), for example, 30 to 95% by mass, preferably 40 to 90% by mass, further preferably 50 to 88% by mass, more preferably 60 to 85% by mass, and most preferably 70 to 80% by mass. If the proportion of the first asphalt is too low, there is a risk that waterproofing properties will decrease.

[0099] The first asphalt composition preferably further contains a first filler, which can improve handling. Examples of the first filler include the fillers exemplified as the second filler. The fillers can be used alone or in combination of two or more. Among the fillers, inorganic fillers are preferred, metal salt particles are more preferred, and metal carbonate particles such as calcium carbonate are even more preferred, because they can easily improve lightness and handling.

[0100] The shape of the first filler (particularly, inorganic filler) is not particularly limited as long as it is granular, and examples thereof include spherical or approximately spherical, ellipsoidal or rod-like, polyhedral (e.g., cubic, rectangular, tetrahedral (pyramidal)), flat (plate-like, scaly, or thin), and irregular shapes. Of these, irregularly shaped granular shapes are commonly used.

[0101] The average particle size of the first filler (particularly inorganic filler) can be selected from the range of, for example, about 10 μm to 10 mm, for example, 10 μm to 5 mm, preferably 20 μm to 3 mm, further preferably 30 μm to 2 mm, more preferably 50 μm to 1 mm, and most preferably 60 to 500 μm. If the average particle size is too small, the effect of improving handleability may be reduced, and if it is too large, the waterproofness may be reduced.

[0102] The maximum particle size of the first filler (particularly, inorganic filler) may be 20 mm or less, preferably 10 mm or less, and more preferably 5 mm or less.

[0103] The bulk density of the first filler (particularly, the inorganic filler) is 10 g / cm 3 or less, for example, 1 to 10 g / cm 3 , preferably 1.2 to 5 g / cm 3 , and more preferably 1.5 to 4 g / cm 3 , more preferably 2 to 3.5 g / cm 3 , and most preferably 2.5 to 3 g / cm 3 If the bulk density of the filler is too high, there is a risk that the lightweight property will decrease.

[0104] The proportion of the first filler is, for example, 1 to 100 parts by mass, preferably 3 to 80 parts by mass, further preferably 5 to 70 parts by mass, even more preferably 8 to 60 parts by mass, and most preferably 10 to 50 parts by mass, relative to 100 parts by mass of the first asphalt. If the proportion of the first filler is too low, the effect of improving handleability may be reduced, and conversely, if it is too high, waterproofing may be reduced.

[0105] The first asphalt composition may further contain a first organic modifier. Examples of the first organic modifier include the organic modifiers exemplified as the second organic modifier. The organic modifiers can be used alone or in combination. Among the organic modifiers, thermoplastic elastomers, tackifiers, and oils and fats are preferred, and styrene-diene copolymers such as styrene-butadiene-styrene block copolymers are particularly preferred.

[0106] The proportion of the first organic modifier may be 100 parts by mass or less per 100 parts by mass of the first asphalt, for example, 1 to 100 parts by mass, preferably 3 to 50 parts by mass, further preferably 5 to 30 parts by mass, even more preferably 8 to 20 parts by mass, and most preferably 10 to 15 parts by mass. If the proportion of the first organic modifier is too high, there is a risk that waterproofing properties will decrease.

[0107] The first asphalt composition may further contain conventional additives. Examples of additives include those exemplified as additives for the second asphalt composition. The additives may be used alone or in combination of two or more. The total proportion of the additives in the first asphalt composition is 50% by mass or less, preferably 0.01 to 30% by mass, and more preferably 0.1 to 10% by mass.

[0108] The penetration (1 / 10 mm) of the first asphalt composition is not particularly limited, but can be selected from a range of about 0 to 300 in a method (25°C) in accordance with JIS K 2207-1996, and from the viewpoint of improving handleability, it may be 100 or less, for example, 1 to 100, preferably 5 to 80, further preferably 10 to 70, more preferably 20 to 50, and most preferably 30 to 40. If the penetration is too small, it may be difficult to form a uniform layer, and conversely, if it is too large, handleability may be reduced.

[0109] The average thickness of the first asphalt waterproofing layer may be 2.0 mm or less, for example, 0.1 to 1.9 mm, preferably 0.2 to 1.8 mm, further preferably 0.3 to 1.7 mm, even more preferably 0.4 to 1.6 mm, and most preferably 0.5 to 1.5 mm. If the average thickness of the first asphalt waterproofing layer is too large, there is a risk that the lightweight properties will decrease.

[0110] (resin layer) The resin layer may be a resin layer formed from either a thermoplastic resin or a thermosetting resin, but from the standpoint of workability and the like, a resin layer formed from a thermoplastic resin is preferred.

[0111] Examples of thermoplastic resins include polyolefin resins (polyethylene resins, polypropylene resins, etc.), styrene resins, acrylic resins, vinyl alcohol resins (ethylene vinyl alcohol resins, etc.), polyester resins (poly-C such as polyethylene terephthalate and polyethylene naphthalate), 2-4 Examples of the thermoplastic resin include alkylene-arylate resins, wholly aromatic polyester resins such as liquid crystal polyester resins, polyamide resins (aliphatic polyamide resins such as polyamide 6 and polyamide 66, wholly aromatic polyamide resins such as aramid resins), polyurethane, etc. These thermoplastic resins can be used alone or in combination of two or more.

[0112] Of these, polyethylene resins, polypropylene resins, and polyester resins are preferred, with polyethylene resins being particularly preferred.

[0113] The proportion of the resin in the resin layer may be 50% by mass or more, preferably 80% by mass or more, further preferably 90% by mass or more, even more preferably 95% by mass or more, and may be 100% by mass.

[0114] The resin layer may further contain additives. Examples of additives include the additives exemplified as additives for the second asphalt composition. The additives may be used alone or in combination of two or more. The total proportion of additives may be 50 parts by mass or less, preferably 0.01 to 30 parts by mass, and more preferably 0.1 to 10 parts by mass, per 100 parts by mass of resin.

[0115] The average thickness of the resin layer may be 100 μm or less, for example, 1 to 100 μm, preferably 3 to 50 μm, further preferably 5 to 30 μm, even more preferably 6 to 20 μm, and most preferably 8 to 15 μm.

[0116] [Weed control sheet manufacturing method and usage method] The weed control sheet of the present invention can be produced by laminating each layer on both sides of an asphalt-impregnated fiber layer. For example, the weed control sheet shown in Figure 1 may be produced by heating asphalt (third asphalt) to reduce its viscosity and allowing it to penetrate into a fiber structure (a fiber structure for forming an asphalt-impregnated fiber layer), and then laminating a second asphalt waterproofing layer and a heat-shielding layer in that order on one side of the asphalt-impregnated fiber structure, and then laminating a first asphalt waterproofing layer and a resin layer in that order on the other side.

[0117] In producing the asphalt-impregnated fiber layer, the heating temperature for reducing the viscosity of the asphalt is, for example, 80 to 250°C, preferably 120 to 240°C, more preferably 150 to 200°C, and most preferably 160 to 180°C.

[0118] Examples of methods for impregnating the fiber structure with asphalt include a method in which the fiber structure is impregnated with asphalt using a coating roll or the like, and a method in which asphalt is applied to the surface of the fiber structure.

[0119] Asphalt application methods include conventional coating methods such as bar coating, spin coating, comma coating, die coating, and spray coating.

[0120] The first and second asphalt waterproofing layers can be laminated on both sides of the asphalt-impregnated fibrous layer by heating and applying the asphalt, similar to the asphalt application method described above. In the manufacture of the asphalt-impregnated fibrous layer, the amount of asphalt can be adjusted so that the first and second asphalt waterproofing layers are simultaneously formed with excess asphalt. Of these, the method of heating and applying asphalt (first and second asphalt) to both sides of the asphalt-impregnated fibrous layer is preferred, as it allows for the easy manufacture of a weed control sheet that is both waterproof and easy to install.

[0121] The method for forming the heat-shielding layer may be, for example, a method in which particles containing porous inorganic particles are spread (laid or scattered) approximately uniformly on the second asphalt waterproofing layer in a molten state, or a method in which the second asphalt waterproofing layer is heated and then the particles are spread approximately uniformly and pressed down with a jig such as an iron bar to adhere them.

[0122] The method for laminating the resin layer may be a method of bonding the resin layer to the first asphalt waterproofing layer in a molten or softened state, or a method of applying the resin layer in a solution state to the surface of the first asphalt waterproofing layer.

[0123] The form of the obtained weed control sheet can be selected depending on the purpose of use. It may be used as a roll body in which a long waterproof sheet is wound into a roll, or the weed control sheet may be used as is in sheet form without being wound.

[0124] The weed control sheet of the present invention may be used by laying multiple sheets on the ground with their edges overlapping each other in order to suppress the growth of plants such as weeds. Specifically, the weed control sheets may be laid with their edges overlapping each other, and the adjacent edges may be melted to firmly bond them together, or they may be fixed more firmly using conventional fixing devices, if necessary. [Example]

[0125] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. Details of the materials of the weed control sheets used in the examples and the methods for evaluating various properties are provided below.

[0126] [material] Raw material: Toyobo MC Co., Ltd. "YGA4151P" Blown asphalt: Idemitsu Kosan Co., Ltd. "Blown Asphalt 10-20", penetration (25°C) 16 (1 / 10 mm), softening point 110°C, elongation (25°C) 2 cm, toluene soluble content 99.77% Straight asphalt: Idemitsu Kosan Co., Ltd. "Straight Asphalt 60-80", penetration (25°C) 66 (1 / 10 mm), softening point 47°C Film: Polyethylene film, 0.01 mm thick Glass foam A: "Bub Glass" manufactured by Murakami Kaimeido Co., Ltd., 1mm opening, not passed Glass foam B: Otsubo GSI Co., Ltd. "Foam G; OSG.", 1mm opening, not passed Pumice powder: Ishikawa Light F2 manufactured by Ishikawa Light Industrial Co., Ltd. Waste glass: 1mm mesh size, not passed Color Sand Green: "K-11 Green" manufactured by Shinto Toryo Co., Ltd. Calcium carbonate: manufactured by Kochi Heavy Charcoal Co., Ltd., passed through a 200 mesh opening Modified asphalt: a mixture of 84 parts by mass of the straight asphalt and 16 parts by mass of styrene-butadiene-styrene copolymer

[0127] [Softening point and penetration of asphalt composition] The softening point and penetration of the asphalt composition were measured in accordance with JIS K 2207.

[0128] [Bulk density of inorganic particles] The bulk specific gravity of the porous inorganic particles was measured in accordance with JIS Z 2504:2020 using a funnel with an orifice diameter of 2.5 mm and a funnel angle of 60 degrees.

[0129] [Particle size range of inorganic particles] The particle size range of inorganic particles was measured in accordance with Chapter 4, Soil Grain Size Testing, of the Geotechnical Society's "Soil Testing: Fundamentals and Guidelines."

[0130] [Average pore size of inorganic particles and amount of mercury intrusion] The average pore size and mercury intrusion amount of inorganic particles were measured in accordance with JIS R 1655 "Method for testing pore size distribution of molded fine ceramics by mercury intrusion method" using a mercury intrusion porosimeter (Quantachrome, Model PoreMaster-60) according to the following procedure.

[0131] First, 0.2 g of the test specimen was weighed and loaded into a 0.5 mL cell stem. Next, the amount of mercury intrusion was measured in a low-pressure chamber, and then the specimen was removed and measured again in a high-pressure chamber. From these measurement results, the value calculated by the software attached to the measuring device was used as the amount of mercury intrusion for the target test specimen.

[0132] [Temperature change test under exposure conditions] a) The room temperature was set to 35°C.

[0133] b) A stand was placed 700 mm away from the infrared irradiation stand, and the test specimen was stapled to the stand at its edges onto a 455 x 910 mm piece of 12 mm thick plywood (placed so that the heat-shielding layer on the surface was irradiated with infrared rays).

[0134] c) A temperature sensor (T&D Corporation's "Ondotori Temperature Data Logger TR-71wf") was attached with aluminum tape to one location on the back of the test specimen, and then the edges of the test specimen were covered with aluminum tape and the temperature was measured.

[0135] d) The irradiation dose is 0.544 kW / m 2 The specimen was then exposed to infrared light (illuminance: 1310 lux) for 30 minutes.

[0136] Reference example 1 An asphalt-impregnated fiber layer was prepared by impregnating the raw fabric with blown asphalt at a temperature of 180 to 200° C. The proportion of the blown asphalt was 100 parts by mass relative to 100 parts by mass of the raw fabric.

[0137] After impregnation, the mixture was applied to both sides of the asphalt-impregnated fiber layer using a coating roll at a temperature of 180°C so that the first and second asphalt waterproofing layers (a mixture of 89 parts by mass of modified asphalt and 11 parts by mass of calcium carbonate) each had a thickness of 1.0 mm, and the first and second asphalt waterproofing layers were laminated. The softening points of the first and second asphalt compositions were 115°C and the penetration numbers were 32.

[0138] Both the front and back surfaces of the obtained laminate were heated on a hot plate set to 140°C, and then glass foam A was sprayed over the entire surface of one side, and a film was attached to the other side and pressed in place with an iron rod to produce a test specimen (weed control sheet). The weight of the obtained test specimen was measured before and after spraying with glass foam A, and the amount of glass foam A sprayed on the surface (the amount sufficient to cover the entire surface, meaning basis weight) was calculated.

[0139] Example 1 A test specimen was prepared in the same manner as in Example 1, except that glass foam B was sprayed in the basis weight shown in Table 1 instead of glass foam A. An electron microscope photograph of glass foam B used is shown in FIG.

[0140] Example 2 Test specimens were prepared in the same manner as in Example 1, except that pumice powder was sprinkled in the amount shown in Table 1 instead of glass foam A.

[0141] Comparative Example 1 Test specimens were prepared in the same manner as in Example 1, except that waste glass was scattered in the amount shown in Table 1 instead of glass foam A.

[0142] Comparative Example 2 Test specimens were prepared in the same manner as in Example 1, except that colored sand green was sprayed in the amount shown in Table 1 instead of glass foam A.

[0143] The bulk density, average particle size, average pore size, mercury intrusion amount, and spray amount (basis weight) of the inorganic particles used in Reference Example 1, Examples 1 and 2, and Comparative Examples 1 and 2 were measured and the results are shown in Table 1, and the measurement results of particle size distribution are shown in Table 2.

[0144] [Table 1]

[0145] As is clear from Table 1, the glass foam and pumice powder have a smaller basis weight than the colored sand green and waste glass, and are therefore superior in terms of lightness.

[0146] [Table 2]

[0147] The test specimens obtained in Reference Example 1, Examples 1 and 2, and Comparative Examples 1 and 2 were subjected to a temperature change test under exposed conditions, and the results are shown in Table 3.

[0148] [Table 3]

[0149] As is clear from the results in Table 3, Reference Example 1 and Examples 1 and 2, which contained glass foam or pumice powder, had lower back surface temperatures and greater heat insulating effects than Comparative Examples 1 and 2.

[0150] Since the amount of mercury intrusion corresponds to the size of the voids, it can be assumed that the product of the amount of mercury intrusion of the foam shown below and the foam itself corresponds to the total amount of voids in the foam.

[0151] Reference Example 1 (Glass Foam A): 0.3378 cc / g x 534.9 g / m 2 =180.7cc / m 2 Example 1 (Glass Foam B): 0.1920 cc / g x 1041.6 g / m 2 =200.0cc / m 2 Example 2 (pumice powder): 0.4863 cc / g x 925.1 g / m 2 =449.9cc / m 2 Comparative Example 1 (Color Sand Green): 0.0947 cc / g x 1348.7 g / m 2 =127.7cc / m 2 Comparative Example 2 (Waste Glass): 0.0397 cc / g x 2389.4 g / m 2 =94.9cc / m 2

[0152] Considering the relationship between the total amount of voids and the back surface temperature (thermal insulation), it can be assumed that the Reference Example and Working Example have a larger total amount of voids than the Comparative Example, and therefore have improved thermal insulation.

[0153] On the other hand, when comparing Reference Example 1 and Example 1, although there is not much difference in the total amount of voids between the two, Example 1, which has a smaller average pore size, has significantly improved heat insulation. It can be assumed that in Reference Example 1, which has a larger average pore size, the molten asphalt composition penetrates into the pores and fills the voids, thereby reducing the heat-shielding effect.

[0154] Furthermore, a comparison between Comparative Example 1 and Comparative Example 2 reveals that glass as a material has high thermal conductivity but little insulating effect. In contrast, a comparison between Example 2 and Example 3 reveals that, although Example 3 has more than twice the total amount of voids as Example 2, there is no significant difference in the insulating properties between the two. In other words, the insulating effect of the glass foam is higher than that of pumice powder, which indicates that glass has a greater foaming effect than mineral materials such as pumice powder. [Industrial Applicability]

[0155] The weed control sheet of the present invention can be used as a weed control sheet for suppressing the growth of plants such as weeds on roads (roadways, sidewalks, etc.), railways, parks, farms, afforestation areas and their surrounding areas, riverbanks, etc. The weed control sheet of the present invention can also be used as a waterproof sheet for waterproofing rooftops. [Explanation of symbols]

[0156] 1...Weed control sheet 2...Resin layer 3...First asphalt waterproof layer 4...Asphalt-impregnated fiber layer 5...Second asphalt waterproof layer 6...Heat barrier layer

Claims

1. A weed control sheet that can suppress plant growth when laid on the ground and has a heat-shielding layer containing porous inorganic particles with an average pore size of 50 μm or less.

2. a first asphalt waterproofing layer disposed on the side that comes into contact with the ground and formed of a first asphalt composition containing a first asphalt; an asphalt-impregnated fiber layer laminated on the first asphalt waterproofing layer and formed of a fiber structure containing a third asphalt; a second asphalt waterproofing layer laminated on the asphalt-impregnated fiber layer and formed of a second asphalt composition containing a second asphalt; The weed control sheet according to claim 1, further comprising the heat shield layer laminated on the second asphalt waterproof layer.

3. The bulk density of the porous inorganic particles is 1.4 g / cm ３ 3. The weed control sheet according to claim 1 or 2, wherein:

4. The bulk density of the porous inorganic particles is 0.5 to 1.2 g / cm ３ 3. The weed control sheet according to claim 1 or 2, wherein

5. 3. The weed control sheet according to claim 1, wherein the amount of mercury intrusion of the porous inorganic particles is 0.1 cc / g or more.

6. 3. The weed control sheet according to claim 1, wherein the porous inorganic particles have an average particle size of 0.2 to 10 mm.

7. The porous inorganic particles have a basis weight of 1300 g / m ２ 3. The weed control sheet according to claim 1 or 2, wherein:

8. 3. The weed control sheet according to claim 1, wherein the porous inorganic particles are glass foam.

9. 3. The weed control sheet according to claim 2, wherein the penetration of the second asphalt composition is 100 or less.

10. The weed control sheet according to claim 9, wherein the second asphalt composition contains 1 to 100 parts by mass of a second filler per 100 parts by mass of the second asphalt.

11. 3. The weed control sheet according to claim 2, wherein a resin layer is laminated on the surface of the first asphalt waterproof layer.

12. a first asphalt waterproofing layer disposed on the side that comes into contact with the ground and formed of a first asphalt composition containing a first asphalt; an asphalt-impregnated fiber layer laminated on the first asphalt waterproofing layer and formed of a fiber structure containing a third asphalt; a second asphalt waterproofing layer laminated on the asphalt-impregnated fiber layer and formed of a second asphalt composition containing a second asphalt; A method for improving the workability of a weed control sheet by combining a heat shield layer that is layered on top of the second asphalt waterproofing layer and contains porous inorganic particles with an average pore size of 50 μm or less.

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