KR102468013B1 - Agricultural porous laminated film with excellent high temperature reduction effect - Google Patents

Abstract

The present invention provides a porous laminated film for agriculture, which exhibits excellent air permeability, waterproofness, stiffness and durability, and effectively suppresses heat and light in crop cultivation pavement through a mechanism of absorbing heat of vaporization by evaporation of soil moisture, thereby lowering the mortality rate of crops and improving growth. is to do

Description

Agricultural porous laminated film with excellent high temperature reduction effect}

The present invention relates to a porous laminated film for agriculture with excellent high temperature reduction effect that can stably grow crops even when the annual average temperature increases and abnormally high temperatures occur due to climate change.

Due to the influence of global warming, the temperature is rising, and the main production areas of major crops are moving north from the southern region to Chungbuk and Gangwon regions, and the area where crops can be grown is expected to continuously decrease. It is necessary to develop a low-temperature mulching and light-shielding film that can effectively suppress it.

In particular, the existing mulching film used for agriculture causes a greenhouse effect in the space between the soil and the embankment to emit radiant heat much higher than the atmospheric temperature, thereby increasing the mortality rate of crops and negatively affecting growth, quality, and yield. In addition, existing shading materials have large particles and cannot effectively prevent solar damage caused by exposure to direct sunlight and have low temperature reduction effects, so they cannot effectively prevent crops from high-temperature damage. need.

For conventional agricultural mulching films, vinyl films, non-woven fabrics, paper films, etc. were generally used, and conventional light-shielding materials used were net-shaped light-shielding materials and light-shielding materials using opaque films.

In the case of vinyl film, durability, moisture retention, etc. are good, but there is a disadvantage in that the mortality rate of crops is greatly increased during the high-temperature summer season by causing a greenhouse effect in the space between the ridge and the vinyl film to emit high-temperature radiant heat. In addition, due to the characteristics of vinyl, air permeability and moisture permeability are very low, and there is a disadvantage in that a hole must be formed separately, and weeds can grow between the holes. Since the number of holes is very limited, it is difficult to expect a function to lower the temperature.

In the case of a mulching film composed of non-woven fabric, it has high moisture permeability and air permeability, but is heavy, and in the case of a black film, a high temperature problem occurs like a vinyl film, and in the case of a white film, a lot of light penetrates and weeds grow.

Although the paper film can lower the temperature slightly compared to the vinyl film, it has a disadvantage of poor durability. In the process of mulching in spring, it can be easily torn by farming tools, soil, stones, etc., which makes farming inconvenient, and it is vulnerable to rain and wind, so weeds are likely to occur through cracks.

Existing mesh-type shading materials directly expose direct sunlight through an open space and irradiate light to shade-sensitive plants, reducing the blocking effect and failing to completely solve the problem caused by solar radiation. There was a problem in that the effect of temperature reduction and gas exchange was lowered, which negatively affected the growth of crops.

Therefore, it can be used for a long period of time due to its excellent durability, has excellent moisture permeability and air permeability, and can effectively block direct sunlight while allowing appropriate light and air to pass through fine holes, effectively suppressing the problem of high temperature and shading of plant cultivation pavement and soil. There is a need for research and development on multifunctional laminated films.

US Patent Publication No. 4,929,303 (1990.05.29)

The present invention has been made to solve the above problems, and has mechanical properties such as excellent tensile strength and elongation, so that durability is excellent, air permeability and waterproofness, as well as effectively suppressing the heat of crop cultivation packaging to reduce the mortality rate of crops and promote growth It is an object of the present invention to provide a porous laminated film for agriculture that can improve.

In addition, the present invention is to provide an agricultural porous laminated film that has moisture permeability / breathability, allowing the inflow and outflow of water vapor and air, and prevents soil over-moisture by blocking the inflow of moisture due to rainfall.

The present invention is an agricultural porous laminated film having a porous polyolefin base layer and a nonwoven fabric layer laminated on one or both sides of the base layer,

The porous polyolefin base film is (a) linear low-density polyethylene having a density of 0.910 to 0.925 g / cm ³ (b) linear low-density polyethylene having a density of 0.930 to 0.940 g / cm ³ , (c) melt index according to ASTM D 1238 ( 190 ℃, 2.16kg) is 5 to 10g / 10min of low-density polyethylene, (d) calcium carbonate surface coated with C ₉ to C ₂₄ saturated fatty acid, and (e) a porous laminated film for agriculture that is prepared by including titanium dioxide provides

According to one aspect of the present invention, the porous polyolefin base layer (a) density is 0.910 to 0.925 g / cm ³ Based on 100 parts by weight of linear low-density polyethylene, (b) density is 0.930 to 0.940 g / cm ³ Linear 10 to 40 parts by weight of low-density polyethylene resin, (c) 10 to 40 parts by weight of low-density polyethylene resin having a melt index (190 ° C, 2.16 kg) of 5 to 10 g / 10 min according to ASTM D 1238, (d) C ₉ to C ₂₄ It may be prepared by including 80 to 200 parts by weight of calcium carbonate surface-coated with a saturated fatty acid and (e) 3 to 10 parts by weight of titanium dioxide.

According to one aspect of the present invention, the calcium carbonate may include those having an average particle diameter of 1 to 5 μm and a maximum particle diameter of 10 μm or less.

According to one aspect of the present invention, the agricultural porous laminated film may have a basis weight of 10 to 150 g/m 2 and a moisture permeability of 4,000 to 15,000 g/m 24hr.

According to one aspect of the present invention, (a) 10 to 40 parts by weight of a linear low-density polyethylene resin having a density of 0.930 to 0.940 g/cm ³ based on 100 parts by weight of linear low-density polyethylene having a density of 0.910 to 0.925 g/cm ³ , 10 to 40 parts by weight of a low-density polyethylene resin having a melt index (190 ° C, 2.16 kg) of 5 to 10 g / 10 min according to ASTM D 1238, 80 to 200 parts by weight of calcium carbonate surface-coated with C ₉ to C ₂₄ fatty acids, 3 to 10 parts by weight of titanium, 0.1 to 10 parts by weight of metal stearic acid, 1 to 10 parts by weight of an ultraviolet inhibitor, and 0.1 to 10 parts by weight of an antioxidant are mixed and melt-extruded to prepare a compound composition for a porous polyolefin substrate;

(b) forming a porous polyolefin sheet by extruding the compound composition for the porous polyolefin substrate; and

(c) It is possible to provide a method for producing a porous laminated film for agriculture comprising the step of laminating a nonwoven fabric on one or both sides of the porous polyolefin sheet and pressurizing to prepare a porous laminated film.

According to one aspect of the present invention, the calcium carbonate may have an average particle diameter of 1 to 5 μm and a maximum particle diameter of 15 μm or less.

According to one aspect of the present invention, the agricultural porous laminated film may have a basis weight of 10 to 150 g/m 2 and a moisture permeability of 4,000 to 15,000 g/m 24 hr.

The agricultural porous laminated film according to the present invention has excellent mechanical strength such as tensile strength, tear strength, and elongation, and has excellent durability.

In addition, the agricultural porous synthetic film according to the present invention has excellent moisture permeability, and when moisture passing through the film evaporates, it can exhibit a function of significantly lowering the temperature inside and outside the mulching film due to the effect of absorbing vaporization heat from the surroundings. can

Hereinafter, the present invention will be described in more detail through specific examples or examples including the accompanying drawings. However, the following specific examples or examples are only one reference for explaining the present invention in detail, but the present invention is not limited thereto, and may be implemented in various forms.

Also, unless defined otherwise, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms used in the description in the present invention are merely to effectively describe specific embodiments and are not intended to limit the present invention.

Also, the singular forms used in the specification and appended claims may be intended to include the plural forms as well, unless the context dictates otherwise.

In addition, when a certain component is said to "include", this means that it may further include other components without excluding other components unless otherwise stated.

In the case of the conventional mulching and shading film materials, the present invention has disadvantages such as poor durability or heavy weight. There were disadvantages of causing high-temperature damage to plants or excessively moist soil in the rainy season because the complex characteristics of suppressing the rise were not sufficiently harmoniously imparted.

All of the above problems were solved by providing the agricultural porous laminated film of the present invention.

The present invention completed the present invention by providing a porous laminated film for agriculture having a porous polyolefin base layer and a nonwoven fabric layer laminated on one or both sides of the base layer.

In the present invention, the porous polyolefin base layer (a) has a density of 0.910 to 0.925 g/cm ³ Based on 100 parts by weight of linear low-density polyethylene and 100 parts by weight of the linear low-density polyolefin, (b) 10 to 40 parts by weight of a linear low-density polyethylene resin having a density of 0.930 to 0.940 g/cm ³ , (c) a melt index according to ASTM D 1238 (190 ℃, 2.16kg) 10 to 40 parts by weight of a low-density polyethylene resin of 5 to 10 g / 10 min, (d) 80 to 200 parts by weight of calcium carbonate surface-coated with C ₉ to C ₂₄ fatty acids, and (e) titanium dioxide It is prepared by including 3 to 10 parts by weight.

In the present invention, as the porous substrate layer, by using the linear low-density polyethylene as a main component, calcium carbonate surface-treated with a linear low-density polyethylene resin and fatty acid having a low density and another density, the calcium carbonate is dispersed and particles The interface between the resin and the resin is well controlled, and moisture permeation can be controlled due to the formation of micropores, so that excessive moisture in the soil is prevented even during rainfall, and oxygen and air are well permeable to promote plant growth. .

In addition, in the present invention, by mixing titanium dioxide with calcium carbonate, UV protection properties also have an excellent effect.

In addition, in the present invention, when a porous polyethylene substrate made of mixed inorganic particles of the resin composition and fatty acid surface-treated calcium carbonate and titanium dioxide is used, it has excellent durability and is not damaged even when exposed to the outside for a long time and has excellent moisture permeability at the same time. Thus, the temperature control of the soil is smooth.

In the agricultural porous laminate film according to an embodiment of the present invention, as the resin component constituting the porous substrate, a) density of 0.910 to 0.925 linear low density polyethylene, relative to 100 parts by weight of the linear low density polyethylene resin (b) density 10 to 40 parts by weight of a linear low density polyethylene resin of 0.930 to 0.940, (c) 10 to 40 parts by weight of a low density polyethylene resin having a melt index (190 ° C, 2.16 kg) of 5 to 10 g / 10 min according to ASTM D 1238 mixed resin and (d) 80 to 200 parts by weight of calcium carbonate surface-coated with fatty acids of C ₉ to C ₂₄ and (e) 3 to 10 parts by weight of titanium dioxide as inorganic particles for imparting porosity to the resin. By doing this, excessive moisture is prevented from penetrating into the inside during the rainy season to avoid an overhumid state, and at high temperatures, the moisture inside is vaporized and released to the outside of the porous substrate.

Due to the heat of vaporization absorbed when the moisture is vaporized, the temperature inside and outside the soil is lowered, so that plants can grow well. In addition, the porous synthetic film for agricultural use includes calcium carbonate and titanium dioxide, which are surface-treated with fatty acids, and has a function of blocking ultraviolet rays to give an effect of protecting the film.

In particular, as the agricultural porous laminated film contains calcium carbonate and titanium dioxide, the color of the film is further whitened, and the light reflection effect such as direct sunlight is excellent, and thus the surface temperature and soil temperature of the agricultural porous laminated film are improved. Keeping it low can make it more effective.

Of course, a sunscreen may be further included in the agricultural porous laminate film.

In the present invention, when the resin component constituting the substrate includes high-density polyethylene or polypropylene, excessive porosity appears, and in particular, polypropylene is difficult to process due to crystallinity.

If porosity is excessively created, excessive moisture penetrates into the inside during the rainy season and becomes over-humidified, which rather inhibits plant growth, which is also not good, and it is not easy to maintain a certain amount of moisture inside the soil.

In the present invention, when the surface-treated calcium carbonate is used, it is combined with the linear low-density and low-density polyethylene mixed resin components constituting the substrate to maintain a constant moisture and to uniformly disperse the calcium carbonate, resulting in large local pores. It is good to prevent the penetration of excessive water due to the occurrence of

That is, in the present invention, linear low-density polyethylene is used as a main component, and a mixed resin with low-density polyethylene, calcium carbonate surface-treated with fatty acids, and a certain amount of titanium dioxide are mixed to form an appropriate interface at the interface of inorganic particles, thereby forming the interface of the present invention. It is believed to impart complex characteristics such as moisture permeability, air permeability, moisture resistance, light reflection characteristics, and the effect of suppressing the increase in surface and soil temperature due to the infrared reflection reduction function to the agricultural porous synthetic film.

As long as the calcium carbonate according to an embodiment of the present invention is surface treated with fatty acid, the calcium carbonate is talc, clay, kaolin, silica, diatomaceous earth, magnesium carbonate, calcium chloride, calcium sulfate, aluminum hydroxide, zinc oxide, magnesium hydroxide, oxide It may be replaced with or further included with any one or more inorganic particles selected from titanium, alumina, mica, asbestos powder, zeolite, silicate clay, and the like.

In addition, the average particle size of the calcium carbonate according to an embodiment of the present invention may be 1 to 5 μm, preferably 2 to 4 μm, and more preferably 2 to 3 μm, but it is necessarily limited thereto it is not going to be

In addition, the maximum particle size of the calcium carbonate according to an embodiment of the present invention may be 15 μm, preferably 12 μm, and more preferably 10 μm, but is not necessarily limited thereto.

As the calcium carbonate satisfies both the average particle size and the maximum particle size, the uniformity of pores in the agricultural porous laminated film is excellent, moisture can be emitted uniformly to the outside, and the surface and soil temperature due to vaporization heat absorption are further lowered can have significant effects.

In addition, it is possible to effectively prevent water from being absorbed into the agricultural porous laminated film during heavy rain, thereby suppressing necrosis of the roots of crops due to excessive moisture.

A porous laminated film for agriculture according to an embodiment of the present invention may have a basis weight of 10 to 150 g/m 2 and a moisture permeability of 4,000 to 15,000 g/m 24hr, preferably a basis weight of 15 to 120 g/m 2 and a moisture permeability of 4,000 to 15,000 g/m 2 . May be 5,000 to 11,000 g / m 24 hr, more preferably, the basis weight is 20 to 90 g / m 2, and the moisture permeability may be 6,000 to 10,000 g / m 24 hr, but is not necessarily limited thereto.

By satisfying the basis weight and moisture permeability, the water vapor of the soil can be smoothly discharged to the outside, and the temperature inside the soil can be lowered. It can prevent the growth of plants caused by this.

As the agricultural porous laminate film is used, the surface temperature is lowered by 15 to 30 ° C on average compared to the case of using a conventional mulching film, and the soil temperature is lowered by 10 to 13 ° C on average.

This may have an effect of reducing the probability of dying of plants by 20 to 30% due to high temperatures in summer, and may have an effect of increasing plant growth by 28 to 56% or more.

The resin composition used to prepare the porous polyolefin substrate may further include 0.1 to 20 parts by weight of an antioxidant and 0.1 to 20 parts by weight of a UV stabilizer based on 100 parts by weight of the base resin. An additive such as an antibacterial agent may be used without limitation.

The porous polyolefin substrate is not particularly limited, but the puncture strength may be 400 gf or more, specifically 450 gf or more, and more specifically 500 gf or more. The upper limit is not limited, but may be, for example, 1,000 gf. In the case of having a puncture strength in the above range, thinning of the porous substrate is easy, and mechanical strength of the composite porous separator is improved, which may be more preferable.

In addition, the thickness of the porous polyolefin substrate is not limited, but may be 1 to 100 μm, specifically 5 to 50 μm, and more specifically 6 to 30 μm.

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

In the present invention, the non-woven fabric is laminated with a porous polyolefin substrate, and the porous polyolefin substrate and the corrosive fabric can be bonded by thermal compression or bonded using an adhesive, and the effect of improving strength can be achieved, As the bonding is possible even when heated at a low temperature during thermal bonding, it is possible to achieve improved adhesiveness while maintaining air permeability.

At this time, during the heat sealing, the temperature is preferably in the range of 80 to 150° C. so that the porous polyolefin substrate is not completely melted, so that air permeability is maintained even after bonding.

The nonwoven fabric of the present invention may be a spunbond nonwoven fabric, and the spunbond nonwoven fabric may include a polyester-based resin. Alternatively, in one aspect, a core made of a polyester resin and a polyethylene resin may be made into a filament having a sheath structure. At the same time, strength can be achieved by the resin, and adhesion to the olefin-based resin used in the porous polyolefin substrate can be improved by the polyethylene-based resin coated on the surface in a sheath structure, and thus, during thermal bonding, As adhesion becomes possible even when heated, it is possible to achieve improved adhesiveness while maintaining air permeability.

The spunbond nonwoven fabric is preferably prepared by spinning a fiber coated with a polyethylene resin having a melting point of 100 to 150 ° C. on the surface of the core in a sheath structure using a filament made of polyethylene terephthalate (PET) resin as a core. By using it, it is possible to achieve not only strength but also adhesiveness and air permeability.

The spunbond nonwoven fabric has a thickness of 0.1 to 0.5 mm, tensile strength in the MD direction of 10 to 25 kg/5 cm, tensile strength in the CD direction of 5 to 15 kg/5 cm, and elongation in the MD direction of 40 to 80%, elongation in the CD direction of 40 to 80%, and tear strength of 0.1 to 1.5 kg are suitable for achieving final physical properties. An example of such a spunbond nonwoven fabric is Japan Unitica. (UNITIKA) has ELEVES.

In the present invention, by laminating a nonwoven fabric and a porous polyolefin substrate by the above method, a porous laminated film for agriculture having breathability that does not transmit moisture or water droplets but passes moisture without a process of imparting additional breathability after laminating can be manufactured. can

According to one aspect of the present invention, (a) based on 100 parts by weight of linear low-density polyethylene having a density of 0.910 to 0.925, 10 to 40 parts by weight of a linear low-density polyethylene resin having a density of 0.930 to 0.940, and a melt index of 5 to 10 g / 10 min 10 to 40 parts by weight of low-density polyethylene resin, 80 to 200 parts by weight of calcium carbonate surface-coated with C ₉ to C ₂₄ fatty acids, 3 to 10 parts by weight of titanium dioxide, 0.1 to 10 parts by weight of metal stearic acid, 1 to 10 parts by weight of sunscreen preparing a compound composition for a porous polyolefin substrate by mixing and melt-extruding 0.1 to 10 parts by weight of an antioxidant; (b) forming a porous polyolefin sheet by extruding the compound composition for the porous polyolefin substrate; And (c) it is possible to provide a method for producing a porous laminated agricultural film comprising the step of laminating a nonwoven fabric on one or both sides of the porous polyolefin sheet and pressurizing to prepare a porous laminated film for agriculture.

In step a), after mixing all of the compositions, injecting them into a twin screw extruder and then melt-extruding them to obtain a compound composition for a porous polyolefin substrate in a pellet state, the melting temperature may be 200 to 300 ° C., preferably Preferably it may be 210 to 270 °C, more preferably 220 to 250 °C, but it is not limited thereto as long as the melting temperature is possible.

Since the composition and content of the composition have been described above, they are not described.

In the step b), the pellets prepared in step a) are fed into an extruder to obtain an original sheet, the melting temperature may be 200 to 300 ° C, and the original sheet can be manufactured using the T-die molding machine. However, the method for manufacturing the original sheet is not limited.

The prepared original sheet may produce a porous polyolefin substrate through a stretching process. The stretching may be performed at a stretching temperature of 50 to 100° C., and the stretching ratio may be 2 to 4 times, but is not limited thereto.

In the step c), after applying the hot melt adhesive to the prepared porous polyolefin substrate, a porous laminated film for agriculture can be completed by laminating a nonwoven fabric. The hot melt bonding condition may be performed at 80 to 100 ° C, but is not limited thereto.

Since the average particle diameter or maximum particle diameter of the above-described nonwoven fabric and calcium carbonate has already been described in the present invention, it is omitted here.

The present invention will be described in more detail based on the following Examples and Comparative Examples. However, the following Examples and Comparative Examples are only one example for explaining the present invention in more detail, and the present invention is not limited by the following Examples and Comparative Examples.

[Example 1]

First linear low-density polyethylene resin (density of 0.919 g/cm ³ ) 100 parts by weight, second linear low-density polyethylene resin (density of 0.932 g/cm ³ ) 25 parts by weight, low-density polyethylene (SCG LD777) 25 parts by weight, stearic acid surface treatment 135 parts by weight of calcium carbonate with an average particle diameter of 2.2㎛ and a maximum particle diameter of 10 ㎛ or less, 6 parts by weight of titanium dioxide (CR-834), 1 part by weight of calcium stearate, 3 parts by weight of UV protection agents UV119, UV62, antioxidants (Anox20, Alkanox240) After mixing 0.7 parts by weight and mixing in a Henschel mixer, it was injected into a twin screw extruder having a screw diameter of 130 mm and melt-extruded at 230 ° C. to obtain a compound composition for a porous polyolefin substrate in a pellet state. The obtained compound composition was put into a hopper, and an original sheet was molded using a T-die molding machine having a screw diameter of 130 mm. The formed original sheet was uniaxially stretched three times at a stretching temperature of 70° C. to prepare a porous polyolefin substrate having a basis weight of 35 g/m 2 .

PP nonwoven fabric (Toray Advanced Materials, basis weight: 30 g/m 2) coated with hot melt (Ire AT Co., IH-730H) at 5 g/m 2 was laminated on both sides of the porous polyolefin substrate (30 g/m 2) prepared above, and then 90 A porous laminated film for agriculture was prepared by passing through a roller preheated to ° C.

The physical properties of the prepared film are shown in Table 1 and FIG. 1 below.

[Example 2]

The same procedure as in Example 1 was performed except that the maximum particle diameter of the calcium carbonate was 20 μm or less and the average particle diameter was 2.2 μm.

The physical properties of the prepared film are shown in Table 1 and FIG. 1 below.

[Example 3]

Example 1 was carried out in the same manner except that the content of the calcium carbonate was 50 parts by weight.

[Comparative Example 1]

Example 1 was carried out in the same manner, except that 50 parts by weight of linear low-density polyethylene FT811 was used without using low-density polyethylene. The physical properties of the prepared film are shown in Table 1 and FIG. 1 below.

[Comparative Example 2]

In Example 1, the same procedure was performed except that calcium carbonate without surface treatment with steric acid was used instead of the calcium carbonate. The physical properties of the prepared film are shown in Table 1 and FIG. 1 below.

[Comparative Example 3]

Example 1 was carried out in the same manner except that titanium dioxide was not used. The physical properties of the prepared film are shown in Table 1 and FIG. 1 below.

[Physical property evaluation method]

1. Waterproof pressure: Measured by the JIS L1092 method.

2. Moisture permeability: measured according to the JIS Z0208 method.

3 Over-moisture evaluation: When 1 kg of soil was wrapped with a mulching film and placed in water for 5 hours, over-moisture was measured through the following formula 1.

[Equation 1]

(When the value of over-humidity in Equation 1 is 60 or more: pool

When the overwetting value of Equation 1 is less than 60 and greater than 50: wet

When the value of excessive moisture in Equation 1 is less than 50 and greater than 40: Moist

When the overmoisture value of Equation 1 is 30 or more and less than 40: Less moist

When the value of over-humidity in Equation 1 is less than 30: dry)

waterproof pressure
(kpa) Basis weight (g/㎡) moisture permeability
(g/㎡*24hrs) Excessive moisture Example 1 39 82 9,120 Moisture Example 2 30 80 9,130 wet Example 3 39 93 5,239 dry Comparative Example 1 27 90 4,352 dry Comparative Example 2 32 81 13,500 Goyim Comparative Example 3 34 79 5,400 less moist

As shown in the table above, the film of the present invention has adequate waterproof pressure and moisture permeability of 6,000 g/m2*24hrs or more, so that water vapor is smoothly discharged to the outside while absorbing heat of vaporization to suppress the temperature of the surface and soil in summer. It can also provide a good environment for plant growth.

In addition, when immersed in water, due to excellent waterproofness, water permeates and shows an effect of not being over-humidified, so that excessive moisture due to the rainy season can be prevented from staying inside the ridge.

When plants (Ilcheongung) were grown on the mulching films of Examples 1 to 3 and Comparative Examples 1 to 3, in Examples 1 to 2, the average surface temperature in summer (June to August) was maintained at 28 to 30 ° C. , the soil temperature was also maintained at 27 to 29 ° C, so the length of the plant was long and the number of crops withered was small.

On the other hand, in the case of Comparative Example 1 or Comparative Example 3, the surface temperature rose to a maximum of 59 ° C, and the soil temperature was maintained at a high temperature of 35 to 36 ° C. .

In addition, in the case of Comparative Example 2, there was a problem that the growth of crops was very slow due to excessive moisture absorption during rainfall.

As described above, the present invention has been described by specific details and limited embodiments and drawings, but this is only provided to help a more general understanding of the present invention, the present invention is not limited to the above embodiments, and the present invention Those skilled in the art can make various modifications and variations from these descriptions.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and it will be said that not only the claims to be described later, but also all modifications equivalent or equivalent to these claims belong to the scope of the present invention. .

Claims (7)

An agricultural porous laminated film having a porous polyolefin base layer and a nonwoven fabric layer laminated on one or both sides of the base layer,
The porous polyolefin base layer is (a) 100 parts by weight of linear low-density polyethylene having a density of 0.910 to 0.925 g/cm ³ , and (b) 10 to 40 parts by weight of a linear low-density polyethylene resin having a density of 0.930 to 0.940 g/cm ³ , (c) 10 to 40 parts by weight of a low density polyethylene resin having a melt index (190 ° C, 2.16 kg) of 5 to 10 g / 10 min according to ASTM D 1238, (d) 80 calcium carbonate surface coated with saturated fatty acids of C9 to C24 to 200 parts by weight and (e) 3 to 10 parts by weight of titanium dioxide,
The porous laminated film for agriculture has a basis weight of 20 to 90 g / m 2 and a moisture permeability of 6,000 to 10,000 g / m 2. delete According to claim 1.
The calcium carbonate is an agricultural porous laminate film having an average particle diameter of 1 to 5 μm and a maximum particle diameter of 10 μm or less. delete (a) 10 to 40 parts by weight of a linear low ^{-density polyethylene resin having a density of 0.930 to 0.940 g/cm 3 ,} melt index according to ASTM D 1238 ( 190 ℃, 2.16 kg) 5 to 10 g / 10 min) of 10 to 40 parts by weight of low-density polyethylene resin, 80 to 200 parts by weight of calcium carbonate surface-coated with C9 to C24 fatty acids, 3 to 10 parts by weight of titanium dioxide, 0.1 part by weight of metal stearic acid to 10 parts by weight, 1 to 10 parts by weight of an antioxidant, and 0.1 to 10 parts by weight of an antioxidant, and melt-extruding to prepare a compound composition for a porous polyolefin substrate;
(b) forming a porous polyolefin sheet by extruding the compound composition for the porous polyolefin substrate; and
(c) manufacturing a porous laminated film by laminating and pressing a nonwoven fabric on one or both sides of the porous polyolefin sheet,
The agricultural porous laminated film has a basis weight of 20 to 90 g / m 2 and a water vapor transmission rate of 6,000 to 10,000 g / m 2. According to claim 5,
The calcium carbonate is a method for producing an agricultural porous laminate film having an average particle diameter of 1 to 5 μm and a maximum particle diameter of 15 μm or less. delete