JP4985372B2 - Grass protection sheet - Google Patents

Description

  The present invention relates to a herbicidal sheet having a light-shielding property for preventing grass growth on a road, a railroad, a river, a park, or an orchard and the surroundings, such as a ground, a surface, and particularly a slope.

  In order to prevent grass growth on the ground, surfaces, especially slopes, such as roads, railways, rivers, parks or afforestation areas, and the like, a method of laying grass protection sheets is used. The herbicidal sheet is a sheet having a light shielding property and intended to prevent grass growth in a laid part.

  As a specific example of the herbicidal sheet, Patent Document 1 includes (a) a surface layer made of inorganic particles, (b) a modified asphalt layer, (c) a base material layer that is not penetrated even by grass growth, (D) a modified asphalt layer, (e) a ground surface herbicidal protective sheet comprising a back surface layer selected from the group consisting of a synthetic resin or rubber film layer and an inorganic particle layer, and the above (c) The substrate layer is (1) impregnated with a treating agent having a melting point of 200 ° C. or higher selected from the group consisting of rubber and synthetic resin on a woven or non-woven fabric, and (2) selected from the group consisting of synthetic resin and rubber. Further, there is disclosed a ground surface weed protective sheet characterized by being selected from the group consisting of a woven fabric or a nonwoven fabric laminated on both sides of a self-supporting film having a melting point of 200 ° C. or higher.

Patent Document 2 discloses a lamination of a water-permeable water-repellent granular material having a water permeability coefficient of 1 × 10 ⁻³ cm / sec or more when laminated with a thickness of 5 cm and a fiber structure having a penetration resistance of 1 kg or more. A water-permeable grass-proof structure characterized by being a structure is disclosed.

  Moreover, in patent document 3, it is a sheet | seat which consists of an elastomer raw material in the weed prevention sheet | seat for preventing the growth of weeds by laying on the surface of soil, and the thickness of the sheet is 0.8 to 3.0 mm. Further, there is disclosed a herbicidal sheet characterized in that a numerical value obtained by multiplying the sheet thickness [mm] and 300% modulus [MPa] is 9.0 or more.

  Further, Patent Document 4 is characterized in that a fabric having a resistance to resistance to being pushed up by a weed with strong elongation is superposed on one or both sides of a mat made of entangled fibers produced by needle punching. And a weedproof mat.

Further, Patent Document 5 discloses a protective layer in which at least three layers of (a) a surface layer selected from inorganic particles and a synthetic resin containing inorganic particles, (b) a modified asphalt layer, and (c) a base material layer are laminated. It is a grass sheet, (c) the substrate layer is a substrate selected from woven fabric, knitted fabric and nonwoven fabric, and the woven fabric, knitted fabric and nonwoven fabric are (1) fibers having a melting point of 200 ° C. or higher and (2 ) A herbicidal sheet characterized in that the sheath part is made of a fiber selected from fibers having a core-sheath structure made of a resin having a melting point of 200 ° C. or higher.
Japanese Patent Laid-Open No. 10-266155 JP-A-11-81219 JP 2000-279036 A Utility Model Registration No. 3074880 JP 2002-272348 A

  The present invention has a light-shielding property, weather resistance, mechanical properties for preventing the growth of grass on the ground, surfaces, especially slopes, such as roads, railways, rivers, parks or afforestation gardens and their surroundings. Another object of the present invention is to provide a herbicidal sheet that is excellent in water impermeability and has excellent penetration prevention properties against hard and sharp weed buds.

  The present invention provides (a) a surface layer containing inorganic particles or a synthetic resin containing inorganic particles, (b) a modified asphalt layer, (c) a base material layer, (d) a modified asphalt layer, and (e) a synthetic resin. Or a herbicidal sheet obtained by laminating at least 5 layers of a back surface layer containing a synthetic resin containing inorganic particles in this order, and (c) the base material layer is selected from the group consisting of woven fabric, knitted fabric and non-woven fabric Including at least one base material A and a base material B having a scrim, wherein the woven fabric, knitted fabric, and nonwoven fabric of the base material A include a core-sheath structure fiber having a core portion and a sheath portion; The part is a fiber having a melting point of 200 ° C. or more and the sheath part is a resin having a melting point of 200 ° C. or more, and (e) a herbicidal sheet in which the synthetic resin of the back layer is a hard synthetic resin.

Preferred embodiments of the herbicidal sheet of the present invention are shown below. In the present invention, these embodiments can be appropriately combined.
(1) (e) At least one synthetic resin in which the hard synthetic resin of the back layer is selected from the group consisting of polypropylene, polyester, polycarbonate, polyamideimide, polyesterimide, polyamide, polyimide, polyvinyl chloride, and polyhalogenated polyvinyl It is.
(2) (e) The back layer is a biaxially stretched polypropylene film having a thickness of 10 to 50 μm.
(3) (c) The base material layer has a three-layer structure in which the base material A, the base material B, and the base material A are laminated in this order and adhered or heat-sealed.
(4) The core part and the sheath part are heat-sealed.
(5) The base material B has two or more sets of fiber bundles of a plurality of high-strength fibers that are parallel to each other at approximately equal intervals, and the different sets of fiber bundles cross each other at substantially equal angles. It is.
(6) At least a part of the contact portion between the base material A and the base material B is bonded or thermally fused with a resin having a melting point of 200 ° C. or higher and / or an adhesive that does not thermally decompose at 200 ° C. Yes.
(7) (c) The base material layer has a basis weight of 75 to 500 g / m ² .
(8) (a) The surface layer contains at least one or more flat inorganic particles selected from the group consisting of natural slate, talc and mica.

  Moreover, this invention is the weed prevention structure which laid said grass prevention sheet | seat.

  According to the present invention, to prevent the growth of grass on the ground, surfaces, especially slopes, such as roads, railways, rivers, parks or afforestation gardens, and their surroundings, weather resistance, mechanical properties, It is possible to obtain a herbicidal sheet that is excellent in water impermeability and that is excellent in preventing penetration of hard and sharp weed buds.

  In FIG. 1, typical sectional drawing of the weedproof sheet 10 of this invention is shown. The herbicidal sheet 10 of the present invention includes (a) a surface layer 1 containing inorganic particles or a synthetic resin containing inorganic particles, (b) a modified asphalt layer 2, (c) a base material layer 3, and (d) a modified material. It is a herbicidal sheet in which at least five layers of the asphalt layer 4 and (e) the back layer 5 which is a synthetic resin or a synthetic resin containing inorganic particles are laminated in this order. The herbicidal sheet of the present invention has a light-shielding property and weather resistance for preventing the growth of grass on the ground, surface, especially slopes, such as roads, railways, rivers, parks or afforestation gardens and their surroundings. It is excellent in mechanical properties and water impermeability, and also has excellent penetration prevention properties against hard and sharp weed buds. In this specification, the “slope” means a road, a railroad, and the slopes around these, a slope made by cutting, embankment, etc., a slope between two ground surfaces with a step, and a distance between two ground surfaces. It means the slope between the two ground surfaces. Hereinafter, the present invention will be described in detail.

<(C) Base material layer>
(C) The base material layer includes a base material A that is at least one selected from the group consisting of a woven fabric, a knitted fabric, and a non-woven fabric, and a base material B having a scrim.

<(C) Base material A of base material layer>
The woven fabric, knitted fabric and non-woven fabric constituting the substrate A include fibers having a core-sheath structure having a core portion and a sheath portion. In this specification, the “fiber” includes a single fiber, two or more fibers, a bundle of two or more fibers (fiber bundle), and a yarn (thread) multiplied by two or more fibers.

  The base material A is a base material selected from woven fabric, knitted fabric and non-woven fabric, and can be used in combination of two or more woven fabric, knitted fabric or non-woven fabric. As the base material A, a woven fabric, a knitted fabric, and / or a non-woven fabric composed of fibers having a core-sheath structure in which a core has a melting point of 200 ° C. or higher and a sheath has a melting point of 200 ° C. or higher can be used. Further, as the base material A, a woven fabric, a knitted fabric and / or a nonwoven fabric made of fibers of the core-sheath structure and a woven fabric, a knitted fabric and / or a nonwoven fabric made of fibers having a melting point of 200 ° C. or higher can be used in combination. . The upper limit of the melting point of the fiber is not particularly limited. The upper limit of the melting point of the resin is not particularly limited, but is preferably 500 ° C. or less, more preferably 400 ° C. or less, from the viewpoint of ease of production and cost.

<(C) Base material A of base material layer: core-sheath structure>
(C) The core-sheath structure fiber that can be used as the base material A of the base material layer is a structure in which one component (sheath part) wraps at least a part of the surface of another component (core part). Means a fiber having The fiber having a core-sheath structure preferably has a structure in which the sheath part covers the surface of the core part by 50% or more, further 70% or more, particularly 90% or more. In particular, the core-sheath structure fiber is most preferably a fiber having a structure in which the sheath part completely wraps around the surface of the core part.

  The core is a fiber having a melting point of 200 ° C. or higher. Moreover, it is preferable that the core is a low water-absorbing synthetic resin or an inorganic material because of excellent heat resistance in the process of producing the herbicidal sheet and stability of physical properties during long-term use. For the core, a synthetic resin or an inorganic substance having a water absorption rate (24 hours, 23 ° C.) of preferably 1% or less, more preferably 0.9% or less, and particularly preferably less than 0.8% can be preferably used. As a specific core material, it is preferable to use low water-absorbing nylon 11 or nylon 12, synthetic resin such as polyester or glass, or fibers made of inorganic substances from the viewpoint of water absorption and mechanical strength.

  The material of the sheath is preferably a resin having a melting point of 200 ° C. or higher because of excellent heat resistance in the process of producing the herbicidal sheet and stability of physical properties during long-term use. As the resin having a melting point of 200 ° C. or higher, any natural or synthetic resin having a melting point of 200 ° C. or higher can be used. Particularly, polyamide, polycarbonate, polyphenylene oxide, polyethersulfone, polyamideimide having a melting point of 200 ° C. or higher can be used. Resins such as polyester imide, polyimide, polysulfone, and polyether can be used. In particular, nylon 11 and nylon 12 having low water absorption can be suitably used because they have excellent physical properties during long-term use. Further, as the resin having a melting point of 200 ° C. or higher, partially crosslinked or crosslinked rubber can be used.

  Moreover, it is preferable that the core part and the sheath part are heat-sealed. The thermal fusion can be performed by applying a temperature higher than the melting point of at least one of the core material and the sheath material. The core portion and the sheath portion are heat-sealed so that excellent shape stability can be obtained even when immersed in modified asphalt in a molten state (less than 200 ° C.) in the process of manufacturing the herbicidal sheet. it can.

  When a woven fabric, a knitted fabric, or a non-woven fabric made of a core-sheath fiber having a melting point of 200 ° C. or higher is used as the base material A, (i) part of the core-sheath fiber is made of a resin having a melting point of 200 ° C. or higher. Adhered woven fabric, knitted fabric, non-woven fabric, etc. (ii) Partially woven fabric, knitted fabric, non-woven fabric bonded by an adhesive and / or resin that does not thermally decompose at 200 ° C. (iii) Some It is preferable to use a woven fabric, a knitted fabric, a non-woven fabric or the like in which is thermally fused. The upper limit of the melting point of the resin and the thermal decomposition temperature of the adhesive is not particularly limited, but is preferably 500 ° C. or less, and more preferably 400 ° C. or less from the viewpoint of ease of production and cost.

  In the case of using a woven fabric, a knitted fabric or a non-woven fabric partly bonded with a resin having a melting point of 200 ° C. or higher as the substrate A, the resin having a melting point of 200 ° C. or higher is a natural material having a melting point of 200 ° C. or higher. Any synthetic resin can be used as long as it is a resin such as polyamide, polycarbonate, polyphenylene oxide, polyethersulfone, polyamideimide, polyesterimide, polyimide, polysulfone, or polyether having a melting point of 200 ° C. or higher. Can be used. In particular, nylon 11 or nylon 12 having low water absorption can be suitably used. As the resin having a melting point of 200 ° C. or higher, partially crosslinked or crosslinked rubber can be used.

  As the substrate A, (ii) a woven fabric, a knitted fabric, or a non-woven fabric partially bonded with an adhesive and / or resin that is not thermally decomposed at 200 ° C. can be used. An adhesive that does not thermally decompose at 200 ° C. means that, in thermogravimetric analysis, the weight loss rate is 1% or less, further 0.5% or less at 200 ° C. under the condition of a heating rate of 5 ° C./min in air. Especially 0% natural or synthetic resin.

  As an adhesive that does not thermally decompose at 200 ° C., an inorganic adhesive or an organic adhesive that does not thermally decompose at 200 ° C. can be used. Examples of adhesives that do not thermally decompose at 200 ° C. include urethane adhesives, acrylic adhesives, polyamide adhesives, epoxy adhesives, polyester adhesives, nylon / epoxy adhesives, and elastomer / epoxy adhesives. Agent, nitrile / phenolic adhesive, urethane / epoxy adhesive, polyester / epoxy adhesive, polyisocyanate adhesive, polyethyleneimine adhesive, melamine adhesive, urea adhesive, phenolic adhesive, Polychloroprene adhesives, nitrile rubber adhesives, recycled rubber adhesives, SBR adhesives, natural rubber adhesives, and the like can be used.

  As an adhesive that does not thermally decompose at 200 ° C., it is preferable to use a natural or synthetic resin having crosslinkability such as an epoxy resin or a synthetic resin paint that can be used for the surface layer (a) described later.

<(C) Base material A of base material layer: Combined use of fibers having a core-sheath structure and fibers having a melting point of 200 ° C. or higher>
Moreover, as the base material A, a woven fabric, a knitted fabric and / or a nonwoven fabric made of fibers having a melting point of 200 ° C. or higher can be used. The woven fabric, knitted fabric and / or non-woven fabric made of fibers having a melting point of 200 ° C. or higher is made of fibers having a core-sheath structure in which the core portion is made of fibers having a melting point of 200 ° C. or higher and the sheath portion is made of a resin having a melting point of 200 ° C. or higher. The substrate A is preferably used in combination with a woven fabric, a knitted fabric and / or a non-woven fabric. As the fibers having a melting point of 200 ° C. or higher, those composed of organic fibers or inorganic fibers having a melting point of 200 ° C. or higher, such as natural, semi-synthetic and synthetic resin fibers having a melting point of 200 ° C. or higher, and inorganic glass can be used. .

  As the fiber having a melting point of 200 ° C. or higher, an organic fiber or an inorganic fiber made of a resin having a melting point of 200 ° C. or higher, or containing a resin having a melting point of 200 ° C. or higher, such as fiber or glass, can be used. . The upper limit of the melting point of the fiber is not particularly limited.

  In the case of using a woven fabric, a knitted fabric or a non-woven fabric comprising a core-sheath fiber having a melting point of 200 ° C. or higher and a fiber having a melting point of 200 ° C. or higher as the substrate A, the core-sheath fiber and / or the melting point of 200 ° C. Of the above fibers, (ii) woven fabric, knitted fabric, non-woven fabric, etc., in which a part is bonded with a resin having a melting point of 200 ° C. or higher, etc. (ii) with an adhesive and / or resin that does not thermally decompose at 200 ° C. It is preferable to use (iii) a woven fabric, a knitted fabric, a non-woven fabric or the like partially bonded by heat, such as a bonded woven fabric, a knitted fabric, or a non-woven fabric. The upper limit of the melting point of the resin and the thermal decomposition temperature of the adhesive is not particularly limited, but is preferably 500 ° C. or less, and more preferably 400 ° C. or less from the viewpoint of ease of production and cost.

  In the case of using a woven fabric, a knitted fabric or a non-woven fabric partly bonded with a resin having a melting point of 200 ° C. or higher as the substrate A, the resin having a melting point of 200 ° C. or higher is a natural material having a melting point of 200 ° C. or higher. Any synthetic resin can be used as long as it is a resin such as polyamide, polycarbonate, polyphenylene oxide, polyethersulfone, polyamideimide, polyesterimide, polyimide, polysulfone, or polyether having a melting point of 200 ° C. or higher. Can be used. In particular, nylon 11 or nylon 12 having low water absorption can be suitably used. As the resin having a melting point of 200 ° C. or higher, partially crosslinked or crosslinked rubber can be used.

  As the substrate A, (ii) a woven fabric, a knitted fabric, or a non-woven fabric partially bonded with an adhesive and / or resin that is not thermally decomposed at 200 ° C. can be used. An adhesive that does not thermally decompose at 200 ° C. means that, in thermogravimetric analysis, the weight loss rate is 1% or less, further 0.5% or less at 200 ° C. under the condition of a heating rate of 5 ° C./min in air. Especially 0% natural or synthetic resin.

  As an adhesive that does not thermally decompose at 200 ° C., an inorganic adhesive or an organic adhesive that does not thermally decompose at 200 ° C. can be used. Examples of adhesives that do not thermally decompose at 200 ° C. include urethane adhesives, acrylic adhesives, polyamide adhesives, epoxy adhesives, polyester adhesives, nylon / epoxy adhesives, and elastomer / epoxy adhesives. Agent, nitrile / phenolic adhesive, urethane / epoxy adhesive, polyester / epoxy adhesive, polyisocyanate adhesive, polyethyleneimine adhesive, melamine adhesive, urea adhesive, phenolic adhesive, Polychloroprene adhesives, nitrile rubber adhesives, recycled rubber adhesives, SBR adhesives, natural rubber adhesives, and the like can be used.

  As an adhesive that does not thermally decompose at 200 ° C., it is preferable to use a natural or synthetic resin having crosslinkability such as an epoxy resin or a synthetic resin coating that can be used for the surface layer (a) described later.

<(C) Base material B of base material layer>
In terms of increasing the mechanical strength of the weedproof sheet, in the weedproof sheet of the present invention, (c) the base material B of the base material layer has a scrim made of fibers having a melting point of 200 ° C. or higher. preferable. A scrim means a plain woven or twill woven fabric. That is, the scrim has a shape in which two or more sets each having a plurality of parallel fibers and / or threads that are substantially parallel to each other are formed, and different sets of fibers and / or threads cross each other at substantially equal angles. It is. As an example, a scrim having a shape in which two sets of a plurality of parallel and approximately equally spaced fibers and / or yarns intersect each other substantially at right angles can be used. It is also possible to use scrims in which the three sets cross each other at an angle of about 60 degrees. The lower limit of the fiber and / or yarn spacing is preferably a scrim of 3 mm or more, more preferably 4 mm or more, more preferably 5 mm or more, particularly preferably 6 mm or more, from the viewpoint of suppressing the weight and cost of the scrim. The upper limit of the fiber and / or yarn spacing is preferably a scrim of 30 mm or less, more preferably 20 mm or less, more preferably 18 mm or less, from the viewpoint of required mechanical strength.

  Further, the fibers and / or yarns constituting the scrim preferably have a melting point of 200 ° C. or higher. Moreover, since it has high intensity | strength, it is preferable that the fiber which comprises a scrim is a bundle | flux (high-strength fiber bundle) of two or more high-strength fibers. As the high-strength fiber of the high-strength fiber bundle, one or more kinds selected from carbon fiber, aramid fiber, steel fiber, nylon fiber, polyester fiber and glass fiber can be suitably used. From the viewpoint of price and availability, glass can be used. Fibers can be suitably used. The upper limit of the melting point of the fiber is not particularly limited.

<(C) Structure of base material layer>
(C) The base material layer preferably has a three-layer structure in which the base material A, the base material B, and the base material A are laminated in this order. The “three-layer structure” refers to a structure in which the base material A, the base material B, and the base material A are arranged and bonded in this order. In addition, since the base material B has a scrim, there are portions where fibers and / or yarns are not present. In the present specification, such a portion is also referred to as a “three-layer structure”. (C) Since the base material layer has a three-layer structure, the upper surface side and the lower surface side of the base material B located in the middle have a homogeneous structure, and (c) a weedproof sheet using the base material layer is laid. In this case, good flatness can be obtained, and warping of the sheet end can be avoided.

  (C) The base material layer is formed by adhering the base material A and the base material B and by adhering two base materials A at a portion where the base material B does not exist. From the viewpoint of ensuring the adhesion of the base material, (c) the base material layer is a resin having a melting point of 200 ° C. or higher and / or 200 ° C. at least part of the contact portion between the base material A and the base material B. It is preferable to adhere by an adhesive that does not thermally decompose. Alternatively, it is preferable that at least a part of the contact portion between the base material A and the base material B is heat-sealed at a temperature of 200 ° C. or higher. The same applies to a portion where two substrates A are bonded or fused. The base material A and the base material B are bonded with a resin having a melting point of 200 ° C. or higher and / or an adhesive that is not thermally decomposed at 200 ° C., or heat-sealed at a temperature of 200 ° C. or higher. (C) In the process of producing a herbicidal sheet using a base material layer, even if (c) the base material layer is immersed in a modified asphalt in a molten state (less than 200 ° C.), (c) the physical properties of the base material layer are It is not impaired and excellent shape stability can be obtained.

(C) The lower limit of the basis weight (weight per unit area) of the base material layer is 75 g / m ² , preferably 100 g / m ² , more preferably 120 g / m ² from the viewpoint of maintaining the strength of the herbicidal sheet. Particularly preferred is 140 g / m ² . Further, (c) the upper limit of the basis weight of the base material layer is 500 g / m ² or less, preferably 400 g / m, from the viewpoint of securing good workability when constructing the herbicidal sheet and suppressing the cost. ² and more preferably 200 g / m ² . As a specific example of the basis weight of the base material layer including the scrim, a material having a weight of 155 g / m ² can be used. (C) If the basis weight of the base material layer is below the lower limit value, it becomes difficult to obtain a preferable tensile strength or tear strength. If the upper limit value is exceeded, the strength characteristics of the herbicidal sheet are improved, but the sheet weight increases. This is not preferable because the laying workability is lowered.

<(A) Surface layer>
(A) The surface layer is a layer containing inorganic particles or a synthetic resin containing inorganic particles. (A) The surface layer is preferably a layer made of inorganic particles or a synthetic resin containing inorganic particles. (A) As the inorganic particles used for the surface layer, flat inorganic particles of mineral substances such as natural slate sand, mica and talc can be used. The inorganic particles can be used alone or in combination. In the present invention, (a) by using flat inorganic particles in the surface layer, the entire herbicidal sheet does not peel off even in long-term use without relying on the application of a weather-resistant paint, and discoloration and fading are small, The state immediately after construction of the weedproof sheet can be maintained.

  Furthermore, since the weedproof sheet of the present invention has a structure in which flat inorganic particles and modified asphalt compound are laminated, littering as seen in the type of weedproof sheet colored on the nonwoven fabric is discarded. Serious damage such as piercing by cigarettes can be prevented.

  The particle size of the inorganic particles may be any as long as there is no problem in use, preferably 0.1 to 10 mm, more preferably 0.3 to 8 mm, more preferably 0.5 to 6 mm, particularly preferably. Is preferably in the range of 1 to 5 mm. The “particle diameter” refers to the length of the longest of the straight lines connecting any two points of the inorganic particles when the inorganic particles are flat or the like.

  When the inorganic particles are flat or the like, the length of the longest line among the straight lines connecting any two points of the inorganic particles is X, and the longest of the straight lines connecting any two points of the inorganic particles perpendicular to the straight line When the length is Y and the thickness of the thickest part of the flat inorganic particles is Z, the value of Y / X is preferably in the range of 0.2 to 1, more preferably 0.3 to 0.9. A range of 0.5 to 0.8 can be preferably used. The value of Z / X is preferably in the range of 0.002 to 0.4, more preferably in the range of 0.01 to 0.2, and particularly preferably in the range of 0.02 to 0.1. A thing can be used conveniently.

(A) in the surface layer, the inorganic particles of weed sheet surface 1 m ² per are, preferably 100 to 2000 g / ^{m 2,} more preferably 200~1500g / ^{m 2,} particularly preferably from 400~1200g / ^{m 2} Is preferred.

  As the inorganic particles, water repellents, paints, pigments, thickeners, light proofing agents, weathering agents and the like may be added, sprayed, applied, or impregnated as necessary.

  (A) In the surface layer, the synthetic resin containing inorganic particles can be used as a coating film, a sheet, or a film by a method such as bonding, coating, spraying, or impregnation to the (b) modified asphalt layer. As the synthetic resin containing inorganic particles, those containing inorganic particles and a synthetic resin paint can be used. As the synthetic resin containing inorganic particles, it is preferable to use a compound in which 3 to 250 parts by weight of inorganic particles, further 5 to 200 parts by weight, particularly 10 to 180 parts by weight are blended with 100 parts by weight of the synthetic resin coating. It is preferable to add a water repellent, a pigment, a thickener, a light fastener, a weatherproof agent and the like to the synthetic resin containing inorganic particles as necessary.

(A) in the surface layer, the amount of the inorganic particles contained in the synthetic resin, inorganic particles of weed sheet surface 1 m ² per are, preferably from 100 to 2000 g / ^{m 2,} more preferably 200~1500g ^{/ m} 2, Particularly preferably, it is in the range of 400 to 1200 g / m ² .

  (A) As a synthetic resin of the surface layer, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyolefin such as ethylene-acrylic acid derivative, polyurethane, polyester, polycarbonate, polyphenylene oxide, polysulfone, polyethersulfone, polyamideimide, Olefin polymer having two or more double bonds in the main chain such as polyester imide, polyamide, acrylic resin, polybutadiene, styrene-butadiene copolymer, vinyl polymer and olefin having two or more double bonds in the main chain and main chain A copolymer with an olefin having one double bond can be used. It is preferable to use a synthetic resin having excellent weather resistance. It is preferable to use a synthetic resin having excellent light resistance. As the synthetic resin, it is preferable to use a resin having excellent flexibility.

  (A) In the surface layer, as the synthetic resin paint, polyurethane, acrylic resin, ethylene-vinyl acetate copolymer, polyester, polyamide, polyimide, polybutadiene, styrene-butadiene copolymer, or the like can be used. It is preferable to use a synthetic resin paint having excellent weather resistance. As the synthetic resin paint, it is preferable to use an excellent flexibility. In particular, as the synthetic resin coating, at least one monomer selected from acrylic acid esters and methacrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate is used. Preferred is a polymer or a copolymer of at least one monomer and an α-olefin such as ethylene or another vinyl monomer such as styrene.

<Modified asphalt of (b) layer and (d) layer>
As the modified asphalt of the (b) layer and the (d) layer, those containing asphalt and polymer, those containing three components of asphalt, polymer and inorganic filler can be used. As the modified asphalt of the (b) layer and the (d) layer, it is preferable to use those containing 10 to 40 parts by weight of the polymer and 0 to 20 parts by weight of the inorganic filler with respect to 100 parts by weight of the asphalt.

  As the modified asphalt, it is possible to use one prepared by heat mixing at 120 to 200 ° C. for 3 to 30 hours, including one containing asphalt and polymer, one containing three components of asphalt, polymer and inorganic filler. It is preferable because it is excellent in moisture resistance, stretchability and the like.

  In addition to the components described above, modified asphalt includes process oil, petrolatum, ceresin, petroleum resin, and other water repellents, pigments, thickeners, light-proofing agents, and weathering agents that are commonly used in blending synthetic resins and rubbers. An inorganic or organic compounding agent such as may be added.

  In the modified asphalt of the (b) layer and the (d) layer, asphalt may be natural asphalt or asphaltite, natural asphalt, blown asphalt, petroleum asphalt such as cutback asphalt, or these asphalts A mixture or the like is preferred.

  In the modified asphalt of the (b) layer and the (d) layer, polymers include natural rubber, synthetic rubber, a mixture of natural rubber and synthetic rubber, polyethylene, ethylene vinyl acetate copolymer, ethylene and acrylic acid derivatives. Copolymer, polypropylene, polybutene-1, poly-4-methylpentene-1, polystyrene, acrylonitrile / styrene copolymer, ABS resin, polyvinyl chloride, polyacrylonitrile, polymer of styrene and butadiene (for example, SBS, SBR etc.) can be used. A rubber system such as SBS is particularly suitable.

  In the modified asphalt of the (b) layer and the (d) layer, as the inorganic filler, calcium carbonate, magnesium silicate, calcium silicate, aluminum silicate, anhydrous silicic acid, clay, carbon black, talc, mica, sulfuric acid Particulate inorganic fillers such as barium, diatomaceous earth, and silica, and fibrous inorganic fillers such as asbestos and glass fibers can be used.

  The modified asphalt of the (b) layer and the (d) layer has a penetration of preferably 10 dmm to 200 dmm, more preferably 15 dmm to 100 dmm, more preferably 20 dmm to 50 dmm, and particularly preferably 25 dmm. The range of ˜35 dmm is preferable because of excellent flexibility.

  In the present invention, by using the modified asphalt having the above composition as the (b) layer and the (d) layer, a layer having excellent water impermeability is formed on the upper part of the slope, particularly when arranged on the slope. In addition to being able to block water essential for the growth of weeds, if the slope is constructed of embankment, the slope of the slope itself accompanying the infiltration of rainwater from the upper slope (shoulder) By preventing water effectively, it is possible to avoid the collapse of the slope ground due to heavy rain.

<(E) Back layer>
In the weedproof sheet of the present invention, (e) the back layer includes a synthetic resin or a synthetic resin containing inorganic particles. (E) The back layer is preferably a synthetic resin film or a synthetic resin film containing inorganic particles.

  (E) The synthetic resin of the back layer is a hard synthetic resin. By using a film made of a hard synthetic resin as the back layer, weed shoots such as chigaya can be prevented from penetrating the (e) back layer of the weedproof sheet. In addition, taking advantage of the surface smoothness of the synthetic resin film, the growth direction of weed buds can be induced in a direction parallel to the back surface of the sheet.

  (E) As the synthetic resin of the synthetic resin film of the back layer, it is preferable to use a resin excellent in light resistance and weather resistance.

  (E) Specific examples of the synthetic resin for the back surface layer include hard synthetic resins such as polypropylene, polyester, polycarbonate, polyamideimide, polyesterimide, polyamide, polyimide, polyvinyl chloride, polyvinylidene chloride, and other polyhalogenated polyvinyls. A film-like material can be preferably used. In particular, an OPP film (biaxially stretched polypropylene film) produced through a biaxial stretch molding process can be suitably used.

  As the back layer (e) used in the present invention, a hard synthetic resin film having a thickness of preferably 10 to 50 μm, more preferably 12 to 40 μm, and particularly preferably 15 to 30 μm can be suitably used. (E) When the hard synthetic resin film which is a back surface layer is thicker than the said range, although the effect which prevents a shoot of a chigaya penetrates a weedproof sheet becomes high, the softness | flexibility of a weedproof sheet may be impaired. . For this reason, if the herbicidal sheet is manufactured and then packed in a roll shape, problems such as generation of wrinkles on the surface of the sheet may occur, and workability during laying may be impaired in construction work. Moreover, when the synthetic resin film of (e) back layer is thinner than the said range, the effect which prevents a hard and sharp chigaya bud from penetrating a herbicidal sheet becomes small. It is preferable that the hard synthetic resin film is within the above range because these problems do not occur.

  (E) Rubber can be added to the synthetic resin of the back layer. The rubber that can be added to the synthetic resin is a thermoplastic low crystalline elastomer that does not have a clear yield point, or a thermoplastic amorphous elastomer that does not have a clear melting point and yield point, and an elastomer that has rubber elasticity at room temperature. Can be used. Thermoplastic elastomers such as styrene elastomers, olefin elastomers, polyester elastomers and polyamide elastomers can be used.

  Examples of styrene elastomers include styrene-butadiene-styrene copolymers (SBS, etc.), hydrogenated styrene-butadiene-styrene copolymers (SEBS, etc.), hydrogenated styrene-butadiene copolymers (HSBR, etc.), hydrogenated styrene. -Butadiene-styrene copolymers (including all random copolymers, block copolymers, graft copolymers, etc.) such as butadiene-olefin crystal block copolymers (SEBC, etc.) and their hydrogenated products, water Styrene-isoprene copolymer (SEP, etc.), hydrogenated styrene-vinylisoprene copolymer (V-SEPS, etc.), styrene-isoprene-styrene copolymer (SIS, etc.), hydrogenated styrene-isoprene-styrene copolymer Isoprene-styrene copolymers (random copolymers, such as coalescence (SEPS, etc.) Lock copolymer includes all such graft copolymer) and its hydrogenated product can be used.

  As the polyolefin-based elastomer, amorphous or low-crystalline α-olefin (co) polymer such as amorphous polypropylene, a mixture of polyolefin and olefin-based rubber, or the like can be used. As the polyolefin elastomer, ethylene-propylene elastomer (EPR, etc.) and ethylene butene-1 elastomer (EBM, etc.) can be used. As the polyester elastomer, an elastomer made of a polyester-polyether copolymer, a polyester-polyester copolymer, or the like can be used. As the polyamide-based elastomer, an elastomer made of a polyamide-polyester copolymer, a polyamide-polyether copolymer, or the like can be used. Two or more of the above elastomers may be mixed and used.

  (E) Specific examples of rubbers that can be added to the synthetic resin for the back layer include polybutadiene, styrene-butadiene copolymer, polyisobutylene, chloroprene rubber, and nitrile rubber.

  (E) When the back layer includes a synthetic resin containing inorganic particles, as inorganic particles, calcium carbonate, magnesium silicate, calcium silicate, aluminum silicate, anhydrous silicic acid, clay, carbon black, talc, Mica, barium sulfate, diatomaceous earth, silica and the like can be used.

<Manufacturing method>
Next, the manufacturing method of the weedproof sheet of this invention is demonstrated.

  A predetermined sheath portion is heat-sealed to the surface of the predetermined core portion to produce a fiber having a core-sheath structure. The base material A is obtained by producing a woven fabric, a knitted fabric and / or a non-woven fabric using the fibers of the core-sheath structure. Next, the base material B having a predetermined scrim is sandwiched between the two base materials A. By laminating the base material A, the base material B, and the base material A in this order with a resin having a melting point of 200 ° C. or higher and / or an adhesive that does not thermally decompose at 200 ° C. A sheet-like (c) substrate layer can be obtained.

  Next, the (c) base material layer produced as described above is immersed and passed in a predetermined modified asphalt heated and mixed at 170 ° C. or higher and lower than 200 ° C., and (c) both surfaces of the base material layer. A three-layer sheet provided with a predetermined asphalt layer (b) and (d) is prepared. (A) A surface layer is formed by adhering predetermined inorganic particles or a synthetic resin containing predetermined inorganic particles to one surface (surface) of the three-layer sheet. Further, the other surface (back surface) is bonded with a sheet containing a predetermined synthetic resin or a synthetic resin containing inorganic particles, and (e) the back surface layer is formed, thereby obtaining the herbicidal sheet of the present invention. be able to.

<Characteristics of grass protection sheet>
The light transmittance of the herbicidal sheet of the present invention is preferably 10% or less, more preferably 5% or less, and particularly preferably 0%. When the light transmittance is within the above range, it is preferable because weed growth can be effectively prevented.

  The penetration resistance of the weedproof sheet of the present invention is preferably 100 N or more, more preferably 150 N or more, more preferably 200 N or more, and particularly preferably 250 N or more. The penetration resistance is preferably in the above range because weed growth can be effectively prevented and suppressed. “Penetration resistance” is a measured value based on ASTM D 4833.

  The tensile strength of the weedproof sheet of the present invention is preferably 50 N / cm or more, more preferably 80 N / cm or more, more preferably 120 N / cm or more, and particularly preferably 135 N / cm or more. “Tensile strength” is a measured value based on JIS A6013. When the weedproof sheet has a tensile strength in the above range, good continuous productivity is obtained in the process of manufacturing the weedproof sheet, and excellent handling is obtained in the construction process of the weedproof sheet. Can obtain excellent durability.

  The tensile elongation of the herbicidal sheet of the present invention is preferably 15% or more, more preferably 30% or more, and particularly preferably 40% or more. “Tensile elongation” is a measured value based on JIS A6013. In the above range, it is suitable for unevenness of the ground due to moderate flexibility, so it is excellent in handling during construction and excellent in durability. Moreover, since it is excellent in continuous productivity in the process of manufacturing a herbicidal sheet, it is preferable.

  The tear strength of the herbicidal sheet of the present invention is preferably 50 N or more, more preferably 70 N or more, more preferably 90 N / cm or more, and particularly preferably 110 N / cm or more. “Tear strength” is a measured value based on JIS A6013. When the weedproof sheet has a tear strength in the above range, good continuous productivity is obtained in the process of manufacturing the weedproof sheet, and excellent handling is obtained in the construction process of the weedproof sheet. Can obtain excellent durability. Moreover, if the tear strength of the weedproof sheet is within the above range, even when the end portion of the weedproof sheet is fixed using a fixing pin, the durability of the fixed portion (location where stress is concentrated) is sufficiently secured. be able to.

  In the weedproof sheet of the present invention, the total thickness of the five layers from (a) the front surface layer to (e) the back surface layer is preferably in the range of 1 mm to 10 mm, more preferably in the range of 1.5 mm to 8 mm, more preferably. A range of 2 mm to 6 mm, particularly preferably a range of 3 mm to 5 mm, is preferable because the handling ease at the time of construction and the quality of the heat-sealed portion of the adjacent herbicidal sheet can be secured sufficiently stably.

  In the weedproof sheet of the present invention, the ratio of the tensile strength in the machine direction to the transverse direction is preferably in the range of 0.70 to 1.50, more preferably in the range of 0.72 to 1.40, more preferably 0. In the range of .74 to 1.35, particularly preferably in the range of 0.75 to 1.30, physical properties such as tensile strength and tear strength do not depend on the orientation of the sheet, and stable durability is obtained. This is preferable.

  In the weedproof sheet of the present invention, the ratio between the longitudinal direction and the transverse direction of the tear strength is preferably in the range of 0.75 to 1.25, more preferably in the range of 0.80 to 1.20, more preferably 0. .83 to 1.18, particularly preferably 0.86 to 1.16, physical properties such as tensile strength and tear strength do not depend on the orientation of the sheet, and stable durability is obtained. This is preferable.

As an example of mechanical strength, (e) a biaxially stretched polypropylene film having a thickness of 20 μm and a base material layer having a basis weight of 155 g / m ² are used as the back surface layer, and the overall thickness of the weed protection of the present invention is 3 mm. In the case of a sheet, values of a tensile strength of about 110 to 190 N / cm, a tensile elongation of about 50 to 70%, and a tear strength of about 85 to 140 N / cm can be obtained.

  As described above, the herbicidal sheet of the present invention uses a base material layer including a base material A that is at least one selected from a woven fabric, a knitted fabric, and a non-woven fabric, and a base material B having a scrim. Since a specific resin film is selected and used for the back layer, a herbicidal sheet having excellent tear strength and tensile strength and excellent dimensional stability can be obtained. In addition, if the weedproof sheet of the present invention is used, light shielding properties and water impermeability to prevent grass growth on the ground, surfaces, especially slopes, such as roads, railways, rivers, parks or afforestation gardens and their surroundings. In addition, it is possible to prevent water from being sloped due to concentrated heavy rain and the like, and in particular, it is possible to obtain a herbicidal structure that is excellent in preventing penetration of hard and sharp weed buds against a herbicidal sheet.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

<Evaluation method>
1. Tensile strength, tensile elongation, tear strength: In accordance with JIS A6013, using universal material testing machine [UTM-10T manufactured by Orientec Co., Ltd.], tensile speed 100 mm / min, sample width 50 mm, chuck interval 100 mm, Uniaxial tensile strength was measured under the test temperature of 22 ° C.

2. Penetration resistance: performed in accordance with ASTM D 4833. Specifically, as shown in FIGS. 4A and 4B, the penetration resistance of the weedproof sheet is measured using a measuring jig 6 having a tip 7 at the lower end, as shown in FIG. The resistance force when the measuring jig 6 penetrates through the weeded and fixed grass-proof sheet 8 as shown in (C) was measured under conditions of a penetration speed of 300 mm / min and a test temperature of 22 ° C.

<Experiments 1-3>
The following synthetic resin film was laid on the surface of the ground from which weeds were cut, and the weed control effect was confirmed after 2 months.
1) Synthetic resin film • Synthetic resin film a: PE film (polyethylene film), thickness = 30 μm, 1 m × 1 m.
Synthetic resin film b: OPP film (biaxially stretched polypropylene film), thickness = 20 μm, 1 m × 1 m.
Synthetic resin film c: OPP film (biaxially stretched polypropylene film), thickness = 60 μm, 1 m × 1 m.

  In Table 1 and FIG. 2, the result of having observed the penetration state of the bud of Chigaya of Experiments 1-3 is shown.

  In the case of Experiment 3 in which a PE film (polyethylene film) having a thickness of 30 μm was laid, fifteen spots where Tigaya sprouts penetrated the film and grew to 20 mm or more were observed. On the other hand, in the case of Experiment 1 in which an OPP film having a thickness of 20 μm (biaxially stretched polypropylene film) was laid, there was only one place where the buds of chigaya had grown through the film to 20 mm or more. In the case of Experiment 2 in which an OPP film (biaxially stretched polypropylene film) having a thickness of 60 μm was laid, no chigaya buds penetrated the film.

<Examples 1-5, Comparative Examples 1 and 2>
According to the following procedures, a herbicidal sheet was produced under the conditions shown in Table 2.

  The composite nonwoven fabric was passed through modified asphalt that was heated and melted and mixed at 190 ° C. to prepare a three-layer sheet in which layers of modified asphalt were provided on both sides of the composite nonwoven fabric.

The following three types of composite nonwoven fabric (base material layer) were used.
2) Composite nonwoven fabric-Composite nonwoven fabric A: manufactured by AKZO NOBEL, product name: colback; varieties: SNS155 (non-woven fabric-scrim-nonwoven fabric three-layer structure), upper layer and lower layer nonwoven fabric: core-sheath structure, sheath: nylon, Core: polyester, intermediate layer: scrim of glass fiber bundle (reinforcement in two directions in the length direction of the sheet and in the direction perpendicular to the length direction), basis weight = 155 g / m ² , 1 m × 6 m.
Composite nonwoven fabric B: manufactured by AKZO NOBEL, product name: colback; varieties: SNS125 (three-layer structure of nonwoven fabric-scrim-nonwoven fabric), upper layer and lower layer nonwoven fabric: core sheath structure, sheath portion: nylon, core portion: polyester Intermediate layer: scrim of glass fiber bundle (two-way reinforcement in the length direction of the sheet and in the direction perpendicular to the length direction), basis weight = 125 g / m ² , 1 m × 6 m.
Composite nonwoven fabric C: manufactured by Freudenberg, product name: TERBOND • R150 (nonwoven fabric-glass fiber bundle two-layer structure), upper layer nonwoven fabric: core-sheath structure, sheath: nylon, core: polyester, lower layer: glass fiber Bundle (reinforced in one direction in the length direction of the sheet), basis weight = 150 g / m ² , 1 m × 6 m.

  Here, the product name: colback-kind: SNS155 and the product name: colback-kind: SNS125 are non-woven fabric and glass fiber scrims made of fibers of a core-sheath structure (sheath: nylon, core: polyester: PET). Are laminated in the order of non-woven fabric-scrim-non-woven fabric, and are integrally formed by heat-sealing nylon of the sheath portion of the non-woven fabric.

  As the modified asphalt, an SBS modified type penetration of 30 dmm or an APP modified type of penetration of 29 dmm was used.

The three-layer sheet of reforming one side of the asphalt layer (surface side), and the flat slate chips deposited in the range of ^{500g / m 2 ~1000g / m 2} .

The following synthetic resin film was bonded to the other surface (rear surface side) to produce a 5-layer sheet having a thickness of 3.2 mm, and wound around a core of cardboard in a roll shape to produce a herbicidal sheet.
3) Synthetic resin film Synthetic resin film d: HDPE film (high density polyethylene), thickness = 20 μm.
Synthetic resin film e: OPP film (biaxially stretched molded polypropylene), thickness = 20 μm.

  The herbicidal sheet could be produced continuously. Moreover, the light transmittance of any of the herbicidal sheets was 0% and did not transmit light.

  Table 3 shows the results of physical properties such as tensile strength of the obtained herbicidal sheet. The obtained weedproof sheet was laid on the surface of the ground from which weeds were cut, and the weedproof effect was evaluated two months later. Moreover, the result of having observed the penetration state of the bud of Chigaya is shown in FIG. In addition, “workability” in Table 3 is a comprehensive judgment of the ease of handling and easiness in the construction work of the herbicidal sheet, such as the weight, flexibility, and occurrence of wrinkles of the sheet.

  As is clear from these results, when biaxially stretched polypropylene, which is a kind of hard synthetic resin, is used as the back layer, the number of penetrations of chigaya buds is smaller than when high-density polyethylene is used. It was possible to obtain a higher herbicidal effect.

When biaxially stretched polypropylene is used and a composite nonwoven fabric having a basis weight of 155 g / m ² is used as the base material layer, no chigaya buds penetrate (Example 4) or However, the number of penetrations was very small (Examples 2, 3 and 5), and the length of the penetrated eyes was less than 20 mm. After the penetrated chigaya bud penetrated the synthetic resin film on the back side, it could not grow larger than 20 mm. The fiber structure of the composite nonwoven fabric with a large basis weight and the modified asphalt layer impregnated in the composite nonwoven fabric This is thought to be due to a major obstacle to the growth of buds.

It is typical sectional drawing of the weedproof sheet of this invention. It is a top view which shows the penetration state of the chigaya bud two months after laying a synthetic resin film. It is a top view which shows the penetration state of the bud of Chigaya two months after laying a weedproof sheet. It is explanatory drawing of the penetration test of a weedproof sheet, (A) Penetration resistance measuring device figure, (B) Sectional drawing of a measurement jig, (C) The penetration which performed the penetration test of the weedproof sheet using the measurement jig Each state diagram is shown.

Explanation of symbols

1: Surface layer (inorganic particles)
2: Modified asphalt layer 3: Base material layer 4: Modified asphalt layer 5: Back layer 6: Measuring jig 7: Tip portion 8 of measuring jig 10, 10: Weedproof sheet

Claims (10)

(A) a surface layer containing inorganic particles or a synthetic resin containing inorganic particles,
(B) a modified asphalt layer,
(C) a base material layer,
(D) a herbicidal sheet in which at least 5 layers of a modified asphalt layer and (e) a back surface layer including a synthetic resin or a synthetic resin containing inorganic particles are laminated in this order,
(C) The base material layer includes a base material A that is at least one selected from the group consisting of a woven fabric, a knitted fabric, and a non-woven fabric, and a base material B having a scrim,
The woven fabric, knitted fabric and non-woven fabric of the base material A include fibers having a core-sheath structure having a core portion and a sheath portion, and the core portion is a fiber having a melting point of 200 ° C. or higher and the sheath portion is a resin having a melting point of 200 ° C. or higher. ,
(E) A herbicidal sheet in which the synthetic resin of the back layer is a hard synthetic resin.   (E) The hard synthetic resin of the back layer is at least one synthetic resin selected from the group consisting of polypropylene, polyester, polycarbonate, polyamideimide, polyesterimide, polyamide, polyimide, polyvinyl chloride, and polyvinyl halide, The herbicidal sheet according to claim 1.   (E) The herbicidal sheet according to claim 2, wherein the back layer is a biaxially stretched polypropylene film having a thickness of 10 to 50 μm.   (C) The base material layer has a three-layer structure in which the base material A, the base material B, and the base material A are laminated in this order and bonded or heat-sealed. The weedproof sheet of any one of Claims.   The weedproof sheet according to any one of claims 1 to 4, wherein the core portion and the sheath portion are heat-sealed.   The substrate B has two or more sets of fiber bundles of a plurality of high-strength fibers that are substantially equidistantly parallel to each other, and the different sets of fiber bundles are scrims that cross each other at substantially equal angles. The herbicidal sheet according to any one of claims 1 to 5.   At least a part of the contact portion between the base material A and the base material B is bonded or thermally fused with a resin having a melting point of 200 ° C. or higher and / or an adhesive that does not thermally decompose at 200 ° C. The weedproof sheet of any one of claim | item 1 -6. (C) the substrate layer has a basis weight of 75~500g / ^{m 2,} weed sheet according to any one of claims 1-7.   (A) The herbicidal sheet according to any one of claims 1 to 8, wherein the surface layer comprises at least one or more flat inorganic particles selected from the group consisting of natural slate, talc and mica.   The weedproof structure which laid the weedproof sheet of any one of Claims 1-9.

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