Agricultural porous laminated mulching film and manufacturing method thereof

Abstract

The present invention relates to a porous laminated mulching film for agricultural use and a method for manufacturing the same. Specifically, it relates to a porous laminated mulching film for agricultural use and a method for manufacturing the same, which has excellent breathability and moisture permeability to prevent soil from becoming waterlogged or hot, and thus has a soil temperature lowering effect so that it can be used during the cultivation period, while also having significantly improved tensile strength, elongation, and tear strength to ensure excellent durability.

Description

Technology Field

[0001] The present invention relates to a porous laminated mulching film for agricultural use and a method for manufacturing the same. Background Technology

[0002] Agricultural mulching film is a film used to cover the surface of a crop cultivation area, such as furrows, when growing crops. It is used to suppress weed growth in the crop cultivation area, maintain soil moisture, or regulate soil temperature. Additionally, it is used to prevent soil erosion caused by rainwater during rainfall or to create an optimal environment suitable for crop growth.

[0003] These agricultural mulching films are generally made of materials such as polyethylene or polyvinyl chloride, but conventional mulching films have problems such as insufficient permeability, which prevents moisture necessary for crop growth from reaching the ground, and weak impact strength, which causes them to tear easily or break when there is a lot of sunlight.

[0004] To resolve these problems, Japanese Patent Publication No. 1997-300511 A discloses an agricultural thermal insulation material formed by laminating a nonwoven fabric and a porous film. Although this thermal insulation material possesses thermal insulation and water permeability, it prioritizes thermal insulation. Consequently, in the summer, the soil temperature or the surface temperature of the thermal insulation material rises too high, which can cause the above-ground parts of crops to wither easily or the roots to rot. In other words, there is a problem in that it is difficult to use this agricultural thermal insulation material continuously throughout the cultivation period. Furthermore, it still has the problem of having low strength.

[0005] Accordingly, there is a need to develop a new laminated mulching film that has excellent breathability and moisture permeability to prevent soil waterlogging or high temperature, and thus has a soil temperature-lowering effect so that it can be used during the cultivation period, while also having significantly improved tensile strength, elongation, and tear strength, and thus excellent durability. The problem to be solved

[0006] Accordingly, one objective of the present invention is to provide a porous laminated mulching film for agriculture that has excellent breathability and moisture permeability to prevent soil from becoming waterlogged or hot, and thus has a soil temperature lowering effect so that it can be used during the cultivation period, while also having significantly improved tensile strength, elongation, and tear strength and excellent durability.

[0007] In addition, another objective of the present invention is to provide a multi-purpose porous laminated mulching film for agriculture that can induce a temperature-lowering effect in plant cultivation packaging by increasing light reflectivity and whiteness, and prevent fruit cracking and sunscald damage caused by direct reflection by inducing diffuse reflection of direct sunlight.

[0008] In addition, another objective of the present invention is to provide a method for manufacturing the above-mentioned porous laminated mulching film for agricultural use. means of solving the problem

[0009] One embodiment of the present invention is a porous laminated mulching film for agriculture comprising a porous polyolefin substrate layer and a nonwoven fabric layer laminated on one or both sides of the substrate layer,

[0010] The porous polyolefin substrate layer comprises (a) a first linear low-density polyethylene having a density of 0.910 g / cm³ to 0.925 g / cm³, and (b) a density of 0.930 g / cm³ (c) a second linear low-density polyethylene having a melt index (190 °C, 2.16 kg) according to ASTM D1238 of 5 g / 10 min to 10 g / 10 min, (d) C9 to C 24 The present invention provides a porous laminated mulching film for agriculture comprising (e) titanium dioxide (TiO2) and (f) cellulose nanofibers, the surface coated with saturated fatty acids.

[0011] An agricultural porous laminated mulching film according to one embodiment of the present invention has a basis weight of 10 g / m² to 100 g / m² And, the water vapor permeability may be 4,000 g / ㎡*24hr to 15,000 g / ㎡*24hr.

[0012] A porous laminated mulching film for agriculture according to one embodiment of the present invention may have a tensile strength in the MD direction of 3,000 gf / 25 mm to 6,000 gf / 25 mm and a tensile strength in the CD direction of 1,000 gf / 25 mm to 4,000 gf / 25 mm.

[0013] An agricultural porous laminated mulching film according to one embodiment of the present invention may have an elongation in the MD direction of 50% to 200% and an elongation in the CD direction of 50% to 200%.

[0014] A porous laminated mulching film for agriculture according to one embodiment of the present invention may have a tear strength in the MD direction of 500 gf / 50 mm to 2,500 gf / 50 mm and a tear strength in the CD direction of 600 gf / 50 mm to 3,000 gf / 50 mm.

[0015] In addition, another embodiment of the present invention comprises, for 100 parts by weight of a first linear low-density polyethylene having a density of 0.910 g / cm³ to 0.925 g / cm³, a density of 0.930 g / cm³ 10 to 40 parts by weight of second linear low-density polyethylene having a density of 0.940 g / cm³, 10 to 40 parts by weight of low-density polyethylene having a melt index (190°C, 2.16 kg) according to ASTM D 1238 of 5 g / 10 min to 10 g / 10 min, C9 to C 24 A step of preparing a compound composition for a porous polyolefin substrate layer by mixing 80 to 200 parts by weight of calcium carbonate surface-coated with saturated fatty acids, 3 to 10 parts by weight of titanium dioxide (TiO2), and 0.1 to 3 parts by weight of cellulose nanofibers, and melt-extruding;

[0016] A step of forming a porous polyolefin sheet by extruding the above-mentioned compound composition for a porous polyolefin substrate layer; and

[0017] A method for manufacturing an agricultural porous laminated mulching film is provided, comprising the step of manufacturing a porous laminated mulching film by laminating a nonwoven fabric on one or both sides of the porous polyolefin sheet and applying pressure. Effects of the invention

[0018] A porous laminated mulching film for agriculture according to one embodiment of the present invention has excellent breathability and moisture permeability, allowing for smooth inflow and outflow of water vapor and air, preventing excessive moisture in the soil, and has the effect of suppressing the rise in soil temperature.

[0019] In addition, the porous laminated mulching film for agriculture according to one embodiment of the present invention has the advantage of excellent durability due to improved mechanical properties such as tensile strength, elongation, and tear strength.

[0020] In addition, the porous laminated mulching film for agriculture according to one embodiment of the present invention has the effect of inducing a temperature reduction effect in the plant cultivation packaging by increasing light reflectivity and whiteness, and inducing diffuse reflection of direct sunlight, thereby preventing fruit cracking and sunscald damage caused by direct reflection. Specific details for implementing the invention

[0021] The porous laminated mulching film for agriculture and the method for manufacturing the same according to the present invention will be described in detail below.

[0022] Unless otherwise defined herein, all technical and scientific terms have the same meaning as generally understood by one of the art to which the present invention pertains. The terms used in the description of the present invention are merely for the purpose of effectively describing specific embodiments and are not intended to limit the present invention. Additionally, the unit of additives not specifically stated in the specification may be parts by weight.

[0023] Additionally, the singular form used in the specification and attached claims may be intended to include the plural form unless specifically indicated otherwise in the context.

[0024] Throughout the specification describing the present invention, the statement that a part “comprising” a certain component may mean that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0025] Unless otherwise specifically defined in this specification, “combination of these” may mean a mixture or copolymerization of the components.

[0026] Unless otherwise specifically defined in this specification, “A and / or B” may mean an embodiment including both A and B simultaneously, or an embodiment selected from A and B.

[0027] The terms "first," "second," etc., as used in this specification may be used to describe various components, but the components should not be limited by these terms. The terms are used solely for the purpose of distinguishing one component from another.

[0028] Black vinyl, a commercially available mulching film, has the disadvantage of causing soil waterlogging or excessive rise in soil temperature during use. Accordingly, research is being conducted to address these disadvantages, but even if the problems of soil waterlogging or excessive rise in soil temperature are resolved, there are limitations to commercialization because mechanical properties such as tensile strength are reduced, leading to significantly reduced durability.

[0029] Accordingly, the inventors have discovered that if a composition is adopted in which two types of linear low-density polyethylene resins with different densities are included as main components as the composition of the porous polyolefin substrate layer included in the laminated mulching film, and a low-density polyethylene resin, calcium carbonate surface-treated with fatty acids, titanium dioxide (TiO2), and cellulose nanofibers are mixed therein, it is possible to induce diffuse reflection of direct sunlight to prevent fruit cracking and sunscald damage caused by direct reflection, and to prevent soil waterlogging and high temperature by having excellent breathability and moisture permeability, while also having excellent mechanical properties such as tensile strength and elongation and improved durability, a porous laminated mulching film for agriculture can be produced.

[0030] An agricultural porous laminated mulching film according to one embodiment of the present invention comprises a porous polyolefin substrate layer and a nonwoven fabric layer laminated on one or both sides of the substrate layer, and

[0031] The porous polyolefin substrate layer may comprise (a) a first linear low-density polyethylene having a density of 0.910 g / cm³ to 0.925 g / cm³, (b) a second linear low-density polyethylene having a density of 0.930 g / cm³ to 0.940 g / cm³, (c) low-density polyethylene having a melt index (190 °C, 2.16 kg) according to ASTM D1238 of 5 g / 10 min to 10 g / 10 min, (d) calcium carbonate surface-coated with a saturated fatty acid of C9 to C24, (e) titanium dioxide (TiO2), and (f) cellulose nanofibers. By including the above-described composition, the porous laminated mulching film for agriculture can achieve excellent breathability and moisture permeability, as well as mechanical properties such as tensile strength, excellent elongation, and tear strength, while simultaneously significantly improving light reflectivity and increasing whiteness.

[0032] More specifically, the porous laminated mulching film for agriculture described above can form micropores by including the composition described above, thereby preventing excessive moisture from penetrating into the interior and preventing the soil from becoming waterlogged, and at high temperatures, the internal moisture can be vaporized and released to the outside of the film, at which time the heat of vaporization is absorbed from the soil to suppress the rise in soil temperature, and the smooth movement of air can be enabled.

[0033] In addition, by including the above-described composition in the porous laminated mulching film for agriculture, the light reflectance and whiteness are greatly improved, thereby inducing a temperature-lowering effect in the plant cultivation field, suppressing direct reflection that causes cracking and sunscald damage to the fruit, and more effectively inducing diffuse reflection of direct sunlight, so as to prevent cracking and sunscald damage to the fruit.

[0034] In particular, the above-mentioned porous laminated mulching film for agriculture can possess excellent durability by including cellulose nanofibers instead of conventional polyester fibers or other nanofibers, thereby enhancing mechanical properties such as tensile strength, tear strength, and elongation. Although the reason for this is not clear, it appears that the cellulose nanofibers can enhance mechanical properties while improving breathability through bonding with the polyethylene matrix contained in the porous polyolefin substrate layer.

[0035] In one embodiment of the present invention, the porous polyolefin substrate layer may comprise, for every 100 parts by weight of a first linear low-density polyethylene having a density of 0.910 g / cm³ to 0.925 g / cm³, (b) 10 to 40 parts by weight of a second linear low-density polyethylene having a density of 0.930 g / cm³ to 0.940 g / cm³, (c) 10 to 40 parts by weight of low-density polyethylene having a melt index (190 °C, 2.16 kg) according to ASTM D1238 of 5 g / 10 min to 10 g / 10 min, (d) 80 to 200 parts by weight of calcium carbonate surface-coated with a saturated fatty acid of C9 to C24, (e) 3 to 10 parts by weight of titanium dioxide (TiO2), and (f) 0.1 to 3 parts by weight of cellulose nanofibers, but The content range of each composition is not necessarily limited to this.

[0036] By including a composition having the content of the porous polyolefin substrate layer described above, the mechanical properties, air permeability, and moisture permeability of the film can be further improved, and at the same time, the light reflectance and whiteness can be further increased to induce a temperature-lowering effect in the plant cultivation packaging, and direct reflection can be suppressed and diffuse reflection of direct sunlight can be better induced, thereby further preventing fruit cracking and sunscald damage.

[0037] In one embodiment of the present invention, the porous polyolefin substrate layer may further include (g) 1 to 10 parts by weight of an anti-UV agent with respect to 100 parts by weight of (a) a first linear low-density polyethylene having a density of 0.910 g / cm³ to 0.925 g / cm³, but the content range is not necessarily limited thereto.

[0038] In one embodiment of the present invention, the porous polyolefin substrate layer may further comprise (h) 0.1 to 10 parts by weight of a lubricant and (i) 0.1 to 10 parts by weight of an antioxidant, based on 100 parts by weight of (a) a first linear low-density polyethylene having a density of 0.910 g / cm³ to 0.925 g / cm³, but the content range thereof is not necessarily limited thereto. By further comprising the lubricant and the antioxidant within the above content ranges in the porous polyolefin substrate layer, the mechanical properties such as tensile strength and elongation of the porous laminated mulching film for agriculture can be further improved, and the durability can be greatly improved.

[0039] In one embodiment of the present invention, by including the calcium carbonate, an increase in whiteness for a higher light reflectance of the film can be achieved, and the calcium carbonate may have an average particle size of 1 μm to 10 μm, preferably 1 μm to 5 μm, and a maximum particle size of 15 μm, preferably 10 μm or less, but is not necessarily limited thereto. By including calcium carbonate having a size within the above-described range in the porous laminated mulching film for agriculture, not only is there no problem of deterioration in physical properties such as defects occurring during film manufacturing due to reduced dispersibility of calcium carbonate in the polyethylene resin, or the surface being uneven and the film tearing easily, but also superior tensile strength, elongation, tear strength, breathability, moisture permeability, and light reflectance can be achieved.

[0040] In particular, in one embodiment of the present invention, the calcium carbonate is a type of coating agent, C9 to C 24The surface may be treated using saturated fatty acids, wherein the saturated fatty acids may have a melting point of 40°C to 80°C, but are not necessarily limited thereto. That is, saturated fatty acids having a low melting point and satisfying both hydrophilicity and lipophilicity simultaneously can play a role in further breaking up the aggregation of calcium carbonate and promoting dispersion within the polyethylene resin. Specific examples of saturated fatty acids having a melting point of 40°C to 80°C include lauric acid with a melting point of 45°C, myristic acid with two melting points of 54°C and 58°C, palmitic acid with a melting point of 63°C, and stearic acid with a melting point of 71°C, but are not necessarily limited thereto.

[0041] In one embodiment of the present invention, the porous polyolefin substrate layer of the porous laminated mulching film for agriculture may further include additives such as flame retardants and antibacterial agents that are commonly used, in addition to the composition described above.

[0042] In an agricultural porous laminated mulching film according to one embodiment of the present invention, the nonwoven fabric laminated on one or both sides may be a nonwoven fabric containing a polyolefin or a polyester-based resin.

[0043] In the present invention, the nonwoven fabric is laminated with a porous polyolefin substrate. The porous polyolefin substrate and the nonwoven fabric can be bonded by heat pressing or by using an adhesive. In addition to achieving the effect of improving strength, bonding is possible even when heated to a low temperature during heat bonding, thereby achieving improved adhesion while maintaining breathability.

[0044] At this time, it is preferable to set the temperature during the heat sealing to a range of 80°C to 150°C so that the porous polyolefin substrate is not completely melted, thereby maintaining breathability even after bonding.

[0045] The nonwoven fabric of the present invention may be a spunbond nonwoven fabric, and the spunbond nonwoven fabric may include a polyester resin. Alternatively, in one embodiment, it may be manufactured into a filament having a core made of a polyester resin and a polyethylene resin having a sheath structure. This allows strength to be achieved through the resin, and at the same time, the adhesion to the olefin resin used in the porous polyolefin substrate can be improved by the polyethylene resin surface-coated with a sheath structure. Accordingly, since adhesion is possible even when heated to a low temperature during heat bonding, it is possible to achieve improved adhesion while maintaining breathability.

[0046] The above spunbond nonwoven fabric can achieve strength as well as adhesion and breathability by using a fiber manufactured by spinning a filament made of polyethylene terephthalate (PET) resin as a core and a polyethylene resin with a melting point of 100°C to 150°C coated in a sheath structure on the surface of the core.

[0047] The spunbond nonwoven fabric above may be suitable for achieving the final physical properties, but is not limited thereto, to have a thickness of 0.1 mm to 0.5 mm, a tensile strength in the MD direction of 10 kg / 5 cm to 25 kg / 5 cm, a tensile strength in the CD direction of 5 kg / 5 cm to 15 kg / 5 cm, an elongation in the MD direction of 40% to 80%, an elongation in the CD direction of 40% to 80%, and a tear strength of 0.1 kg to 1.5 kg.

[0048] The present invention enables the production of an agricultural porous laminated film having breathability that allows moisture to pass through but does not allow water or water droplets to pass through, without the need for a separate process to impart breathability after lamination, by laminating a nonwoven fabric and a porous polyolefin substrate by the method described above.

[0049] In addition, in one embodiment of the present invention, the porous laminated mulching film for agriculture may have a basis weight of 10 g / m² to 100 g / m² and a moisture permeability of 4,000 g / m²*24hr to 15,000 g / m²*24hr, specifically, a basis weight of 20 g / m² to 80 g / m² and a moisture permeability of 5,000 g / m²*24hr to 10,000 g / m²*24hr, and more specifically, a basis weight of 20 g / m² to 50 g / m² and a moisture permeability of 6,000 g / m²*24hr to 10,000 g / m²*24hr, but is not necessarily limited thereto.

[0050] As the above-mentioned porous laminated mulching film for agriculture satisfies the basis weight and moisture permeability of the aforementioned range, moisture control is smooth, preventing excessive moisture from penetrating into the interior and thus preventing the soil from becoming waterlogged. Furthermore, at high temperatures, the internal moisture can evaporate into water vapor and be released more easily to the outside of the film, thereby absorbing heat of vaporization from the soil to further suppress the rise in soil temperature and enabling more smooth air movement.

[0051] In one embodiment of the present invention, the porous laminated mulching film for agriculture may have a tensile strength in the MD (Machine direction, warp) direction of 3,000 gf / 25 mm to 6,000 gf / 25 mm and a tensile strength in the CD (Cross direction, weft) direction of 1,000 gf / 25 mm to 4,000 gf / 25 mm, and specifically, the tensile strength in the MD direction may be 3,000 gf / 25 mm to 5,000 gf / 25 mm and the tensile strength in the CD direction may be 1,000 gf / 25 mm to 2,500 gf / 25 mm, but is not necessarily limited thereto.

[0052] In one embodiment of the present invention, the porous laminated mulching film for agriculture may have an elongation in the MD direction of 50% to 200% and an elongation in the CD direction of 50% to 200%, specifically, an elongation in the MD direction of 70% to 200% and an elongation in the CD direction of 90% to 200%, and more specifically, an elongation in the MD direction of 80% to 150% and an elongation in the CD direction of 100% to 180%, but is not necessarily limited thereto.

[0053] In one embodiment of the present invention, the porous laminated mulching film for agriculture may have a tear strength in the MD direction of 500 gf / 50 mm to 2,500 gf / 50 mm and a tear strength in the CD direction of 600 gf / 50 mm to 3,000 gf / 50 mm, specifically, the tear strength in the MD direction may be 600 gf / 50 mm to 2,000 gf / 50 mm and the tear strength in the CD direction may be 700 gf / 50 mm to 2,500 gf / 50 mm, and more specifically, the tear strength in the MD direction may be 700 gf / 50 mm to 1,500 gf / 50 mm and the tear strength in the CD direction may be 900 gf / 50 mm to 2,000 gf / 50 mm, but is not necessarily limited thereto.

[0055] Another embodiment of the present invention comprises, for 100 parts by weight of a first linear low-density polyethylene having a density of 0.910 g / cm³ to 0.925 g / cm³, a density of 0.930 g / cm³ 10 to 40 parts by weight of second linear low-density polyethylene having a density of 0.940 g / cm³, 10 to 40 parts by weight of low-density polyethylene having a melt index (190°C, 2.16 kg) according to ASTM D 1238 of 5 g / 10 min to 10 g / 10 min, C9 to C 24A method for manufacturing an agricultural porous laminated mulching film may be provided, comprising the steps of: mixing 80 to 200 parts by weight of calcium carbonate surface-coated with saturated fatty acids, 3 to 10 parts by weight of titanium dioxide (TiO2), and 0.1 to 3 parts by weight of cellulose nanofibers, and melt-extruding to produce a compound composition for a porous polyolefin substrate layer; extruding the compound composition for the porous polyolefin substrate layer to form a porous polyolefin sheet; and laminating a nonwoven fabric on one or both sides of the porous polyolefin sheet and applying pressure to produce a porous laminated mulching film.

[0056] At this time, in the step of preparing the compound composition for the porous polyolefin substrate layer for agricultural use, the melting temperature of the process of obtaining a porous polyolefin substrate compound composition in a pelt state by mixing all the compositions, injecting the mixture into a twin-screw extruder, and then melt-extruding it may be 200 ℃ to 300 ℃, specifically 210 ℃ to 270 ℃, and more specifically 220 ℃ to 250 ℃, but is not necessarily limited thereto.

[0057] In addition, in the step of forming the porous polyolefin sheet, the forming method of feeding the manufactured pellets into an extruder to obtain a base sheet may use a T-die forming machine, but is not necessarily limited thereto, and the manufactured base sheet may be produced into an agricultural porous laminated mulching film through a stretching process, wherein the stretching may be performed at a stretching temperature of 50°C to 100°C and the stretching ratio may be 2 to 4 times, but is not necessarily limited thereto.

[0058] In the step of manufacturing the porous laminated mulching film above, an agricultural porous laminated mulching film can be manufactured by applying a hot melt adhesive to the manufactured porous polyolefin sheet and then laminating a nonwoven fabric, and the hot melt adhesive conditions may be carried out at 80°C to 100°C, but are not limited thereto.

[0060] In addition, since the specific composition and content of the above compositions are the same as those described in the description of the porous laminated mulching film for agriculture, such description is omitted below.

[0062] The present invention will be explained in more detail below based on the following examples and comparative examples. However, the following examples and comparative examples are merely illustrative of the present invention and are not intended to limit the present invention.

[0064] [Methods for Measuring Physical Properties]

[0065] (1) Tensile strength and elongation: Measured using the standard ASTM D882 method. Specifically, a sample film (50 mm X 10 mm) was tested using a universal testing machine (INSTRON), 25 o Under conditions of C / 50%RH, 25 mm / min, measurements were taken for the warp (Machine direction, MD) direction and the weft (Cross direction, CD) direction, respectively.

[0066] (2) Tear strength: Measured separately for the warp (Machine direction, MD) and weft (Cross direction, CD) directions using the ASTM D1938 method.

[0067] (3) Water vapor permeability: Measured using the JIS Z0208 method.

[0069] [Example 1]

[0070] 100 parts by weight of first linear low-density polyethylene resin (SK FT850, density 0.919 g / cm³), 24 parts by weight of second linear low-density polyethylene resin (SK FT811, density 0.932 g / cm³), 25 parts by weight of low-density polyethylene (DOW LD777), 135 parts by weight of stearic acid surface-treated calcium carbonate with an average particle size of 2.2 µm and a maximum particle size of 10 µm, 6 parts by weight of titanium dioxide (TiO2), 1 part by weight of cellulose nanofiber (CNF), a total of 3 parts by weight of UV inhibitors (Polyadchem SABOSTAB UV119, SABOSTAB UV62, 1.5 parts by weight each), 1 part by weight of calcium stearate, 0.17 parts by weight of antioxidant (Asia Additive 1790), and antioxidant (Songwon Industry 0.7 parts by weight of Alkanox 240 were mixed in a Henschel mixer. The mixture was fed into a twin-screw extruder with a screw diameter of 130 mm and melt-extruded at 230 °C to obtain a compound composition for a porous polyolefin substrate layer in pellet form. The obtained compound composition was fed into a hopper and formed into a disc sheet using a T-die extrusion molding machine with a screw diameter of 130 mm. The formed disc sheet was uniaxially stretched twice at a stretching temperature of 70 °C to produce a porous polyolefin substrate with a basis weight of 34.4 g / m².

[0071] A porous laminated mulching film for agriculture was manufactured by laminating a PP nonwoven fabric (Toray Advanced Materials, basis weight: 30 g / m²) coated with 5 g / m² of hot melt (Ire AT Co., IH-730H) onto one side of the porous polyolefin substrate (30 g / m²) manufactured above, and then passing it through a roller preheated to 90 ℃.

[0072] The physical properties of the manufactured laminated film are shown in Table 1 below.

[0074] [Comparative Example 1]

[0075] In the above Example 1, a porous laminated mulching film was prepared in the same manner as in Example 1, except that a compound composition for a porous polyolefin substrate layer was obtained without using titanium dioxide.

[0076] The physical properties of the manufactured laminated film are shown in Table 1 below.

[0078] [Comparative Example 2]

[0079] In the above Example 1, a porous laminated mulching film was prepared in the same manner as in Example 1, except that a compound composition for a porous polyolefin substrate layer was obtained without using cellulose nanofibers.

[0080] The physical properties of the manufactured laminated film are shown in Table 1 below.

[0082] [Comparative Example 3]

[0083] In the above Example 1, a porous laminated mulching film was prepared in the same manner as in Example 1, except that calcium carbonate without surface treatment was used instead of calcium carbonate with stearic acid surface treatment.

[0084] The physical properties of the manufactured laminated film are shown in Table 1 below.

[0086] [Comparative Example 4]

[0087] In the above Example 1, a porous laminated mulching film was prepared in the same manner as in Example 1, except that the first linear low-density polyethylene (SK FT850, density 0.919 g / cm³) was not used, and the second linear low-density polyethylene (SK FT811, density 0.932 g / cm³) was used in an amount equal to that of the first linear low-density polyethylene.

[0088] The physical properties of the manufactured laminated film are shown in Table 1 below.

[0090] [Comparative Example 5]

[0091] In the above Example 1, a porous laminated mulching film was prepared in the same manner as in Example 1, except that the second linear low-density polyethylene (SK FT811, density 0.932 g / cm³) was not used, and the first linear low-density polyethylene (SK FT850, density 0.919 g / cm³) was used in an amount equal to that amount.

[0092] The physical properties of the manufactured laminated film are shown in Table 1 below.

[0094] [Comparative Example 6]

[0095] In the above Example 1, a porous laminated mulching film was prepared in the same manner as in Example 1, except that the first linear low-density polyethylene and the second linear low-density polyethylene were not used, and low-density polyethylene (DOW LD777) was used in an amount equal to that.

[0096] The physical properties of the manufactured laminated film are shown in Table 1 below.

[0098] [Comparative Example 7]

[0099] A porous laminated mulching film was prepared in the same manner as in Example 1, except that cellulose nanofibers were not used and polyethylene terephthalate (PET) fibers were used in the same amount.

[0100] The physical properties of the manufactured laminated film are shown in Table 1 below.

[0102] [Comparative Example 8]

[0103] A porous laminated mulching film was prepared in the same manner as in Example 1, except that cellulose nanofibers were not used and polyacrylonitrile (PAN) nanofibers were used in an amount equal to that of cellulose nanofibers.

[0104] The physical properties of the manufactured laminated film are shown in Table 1 below.

[0106] Tensile strength (gf / 25 mm) Elongation rate (%) Tear strength (gf / 50 mm) Moisture permeability (g / ㎡*24hr) MD CD MD CD MD CD Example 1 3778 1452 108 122 797 981 6523 Comparative Example 1 3688 1374 101 109 750 939 3900 Comparative Example 2 2900 950 70 80 480 650 6100 Comparative Example 3 3503 1360 98 108 748 932 3820 Comparative Example 4 3100 1270 101 110 710 908 4500 Comparative Example 5 3100 1265 103 110 690 902 4500 Comparative Example 6 3000 1230 95 102 650 880 4300 Comparative Example 7 3311 1303 98 110 655 887 4190 Comparative Example 8 3181 1273 93 101 645 868 5100

[0107] As can be seen in Table 1 above, the porous laminated mulching film for agriculture according to Example 1 has a moisture permeability of 4,000 g / m² * 24hr or more, specifically 6,000 g / m² * 24hr or more, compared to the films according to Comparative Examples 1 to 6, and at the same time, mechanical properties such as tensile strength, elongation, and tear strength are significantly improved.

[0108] Therefore, the porous laminated mulching film for agriculture according to the present invention has excellent breathability and moisture permeability, allowing for smooth inflow and outflow of water vapor and air, preventing excessive moisture in the soil, and suppressing the rise in soil temperature. In addition, it has the advantage of having excellent durability due to improved mechanical properties.

[0109] As a result of mulching the soil using the mulching films of Example 1 and Comparative Examples 1 to 6, Example 1 had a ridge surface temperature reduction effect of 0 to 35 ℃ and a soil temperature reduction effect of 0 to 10 ℃ compared to Comparative Examples 1 to 6.

[0110] In addition, when plants (Cnidium officinale) were cultivated in soil mulched with the mulching films of Example 1 and Comparative Examples 1 to 6, Example 1 showed a 32% increase in plant height compared to Comparative Examples 1 to 6, a 76% decrease in mortality rate, and an approximately 249% increase in yield per plant of Cnidium officinale.

[0111] As described above, the porous mulching film of the present invention has been explained through specific details and limited embodiments; however, this is provided merely to aid in a more comprehensive understanding of the present invention, and the present invention is not limited to the above embodiments. Those skilled in the art can make various modifications and variations from this description.

[0112] Accordingly, the scope of the present invention is not limited to the described embodiments, and all things equivalent to or having equivalent variations to the claims set forth below, as well as the claims set forth below, shall be considered to fall within the scope of the concept of the present invention.

Claims

Claim 1 An agricultural porous laminated mulching film comprising a porous polyolefin substrate layer and a nonwoven fabric layer laminated on one or both sides of the substrate layer, wherein the porous polyolefin substrate layer comprises, for every 100 parts by weight of a first linear low-density polyethylene having a density of 0.910 g / cm³ to 0.925 g / cm³, (b) 10 to 40 parts by weight of a second linear low-density polyethylene having a density of 0.930 g / cm³ to 0.940 g / cm³, (c) 10 to 40 parts by weight of low-density polyethylene having a melt index (190 °C, 2.16 kg) according to ASTM D1238 of 5 g / 10 min to 10 g / 10 min, and (d) C9 to C 24 The agricultural porous laminated mulching film comprises 80 to 200 parts by weight of calcium carbonate surface-coated with saturated fatty acids, (e) 3 to 10 parts by weight of titanium dioxide (TiO2), and (f) 0.1 to 3 parts by weight of cellulose nanofibers, wherein the agricultural porous laminated mulching film has a basis weight of 10 g / m² to 100 g / m² and a moisture permeability of 5,000 g / m²*24hr to 15,000 g / m²*24hr, wherein the agricultural porous laminated mulching film has a tensile strength in the MD direction of 3,000 gf / 25mm to 6,000 gf / 25mm and a tensile strength in the CD direction of 1,000 gf / 25mm to 4,000 gf / 25mm, and wherein the agricultural porous laminated mulching film has an elongation in the MD direction of 80% to The agricultural porous laminated mulching film has a CD direction elongation of 150% and a CD direction elongation of 100% to 180%, and the above agricultural porous laminated mulching film has a MD direction tear strength of 500 gf / 50 mm to 2,500 gf / 50 mm and a CD direction tear strength of 600 gf / 50 mm to 3,000 gf / 50 mm. Claim 2 delete Claim 3 In claim 1, the porous polyolefin substrate layer comprises (a) a density of 0.910 g / cm³ A porous laminated mulching film for agriculture, comprising (g) 1 to 10 parts by weight of an anti-UV agent per 100 parts by weight of a first linear low-density polyethylene having a density of 0.925 g / cm³. Claim 4 In claim 1, the porous polyolefin substrate layer comprises (a) a density of 0.910 g / cm³ A porous laminated mulching film for agriculture, comprising (h) 0.1 to 10 parts by weight of a lubricant and (i) 0.1 to 10 parts by weight of an antioxidant, based on 100 parts by weight of a first linear low-density polyethylene having a density of 0.925 g / cm³. Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 For 100 parts by weight of a first linear low-density polyethylene having a density of 0.910 g / cm³ to 0.925 g / cm³, a density of 0.930 g / cm³ 10 to 40 parts by weight of second linear low-density polyethylene having a density of 0.940 g / cm³, 10 to 40 parts by weight of low-density polyethylene having a melt index (190°C, 2.16 kg) according to ASTM D 1238 of 5 g / 10 min to 10 g / 10 min, C9 to C 24 A step of preparing a compound composition for a porous polyolefin substrate layer by mixing 80 to 200 parts by weight of calcium carbonate surface-coated with saturated fatty acids, 3 to 10 parts by weight of titanium dioxide (TiO2), and 0.1 to 3 parts by weight of cellulose nanofibers, and melt-extruding; a step of forming a porous polyolefin sheet by extruding the compound composition for the porous polyolefin substrate layer; and a step of preparing a porous laminated mulching film by laminating a nonwoven fabric on one or both sides of the porous polyolefin sheet and applying pressure. A method for manufacturing an agricultural porous laminated mulching film comprising: the agricultural porous laminated mulching film having a basis weight of 20 g / ㎡ to 50 g / ㎡ and a moisture permeability of 5,000 g / ㎡*24hr to 10,000 g / ㎡*24hr; the agricultural porous laminated mulching film having a tensile strength in the MD direction of 3,000 gf / 25mm to 6,000 gf / 25mm and a tensile strength in the CD direction of 1,000 gf / 25mm to 4,000 gf / 25mm; the agricultural porous laminated mulching film having an elongation in the MD direction of 80% to 150% and an elongation in the CD direction of 100% to 180%; and the agricultural porous laminated mulching film having a tear strength in the MD direction A method for manufacturing an agricultural porous laminated mulching film having a tear strength of 500 gf / 50 mm to 2,500 gf / 50 mm and a tear strength in the CD direction of 600 gf / 50 mm to 3,000 gf / 50 mm. Claim 10 delete Claim 11 delete Claim 12 delete Claim 13 delete

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