JPH05284859A - Porous laminated film for culturing farm product and culturing method of farm product using the same film - Google Patents

Abstract

PURPOSE:To obtain the subject film consisting of a drawing type porous film made porous by drawing a non-porous film and a porous film formed from the non-porous film by physical boring other than drawing and having high strength and good moisture permeability, water proof property and windbreak property. CONSTITUTION:A composition obtained by blending a linear low density polyethylene resin with a calcium carbonate filler and butadiene rubber is subjected to extrusion molding with a T die extruder to form a non-porous film, which is then drawn in the monoaxial direction at 80 deg.C to provide a drawing type porous film. On the other hand, the non-porous film is pressed through a pair of nipping rollers in which either one roller is coated with fine artificial diamond powder to afford a porous film, which is then laminated with the drawing type porous film and the laminate is passed through heated uneven rolls made of a metal. Thereby, 15% of whole area of the film is thermally fused to provide the objective film having 0.5-100mum average pore diameter, 1000mmH2O resistance to water pressure and 1000-10000g/m<2> day moisture permeability.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is excellent in moisture permeability, waterproofness, and windproofness, and can obtain high-quality agricultural products by controlling the water content and carbon dioxide concentration in the soil. The present invention relates to a porous laminated film for agricultural product cultivation, which has high strength and is not damaged even when agricultural work is performed on the film, and has a long service life, and a method for cultivating agricultural products using the same.

[0002]

2. Description of the Related Art Conventionally, forcible cultivation has been carried out in a greenhouse for early harvesting of agricultural products such as high-quality fruits, fruits and vegetables, and leafy vegetables. Among these agricultural products, fruits such as tangerines, fruit vegetables such as tomatoes and watermelons, and root vegetables such as radish are artificially irrigated from the latter half of their growth to their maturity in a greenhouse to reduce soil moisture. It is managed and the environment is improved.

That is, among these agricultural products, especially fruits such as mandarin orange are dissolved and absorbed in water when nutrients such as nitrogen are absorbed when water is abundantly supplied near the ripening stage. Since it is easy, it causes overnutrition, which results in enlargement of agricultural products, but it becomes watery, and the taste becomes pale. This causes deterioration of the quality of agricultural products.

Therefore, in the greenhouse cultivation of these agricultural products, it has been attempted to artificially control the soil moisture content or raise the soil temperature from the latter half of its growth to its maturity.

However, in the greenhouse cultivation of these agricultural products, the construction cost of the house is expensive, a huge labor cost is required for the temperature and moisture management in the house, and the harvested agricultural products are also expensive, so that they are widely spread. The reality is that they have not done so.

On the other hand, it is impossible to control rainfall, which is a natural phenomenon, in open field cultivation, and the quality of agricultural products depends on the weather before harvesting.

[0007] In addition, the import of oranges from April 1991 was liberalized, which resulted in the complete liberalization of all fruits. In the age of international competition for agricultural products, High quality that meets the needs of consumers,
And the production and supply of safe agricultural products will become an important issue.

[0008] Therefore, in order to solve these problems and to improve the international competitiveness of agricultural products, various single-layer type or laminated type synthetic resin films are used. It has been proposed to cover the soil surface from the latter half of growth to the maturity to control soil moisture and soil temperature.

That is, as a film for cultivating agricultural products, a non-porous waterproof synthetic resin film can be used to cover the soil surface from the latter half of fruit growth to the mature period to control soil moisture to a low level or to control soil temperature. Although proposed, this method improves the quality of agricultural products, but as a result of the water content in the ground rising and accumulating on the lower surface of the film, the roots of fruit trees and fruit vegetables growing in the ground seek water. If you look up, roots rot due to overhumidity in the ground, root carbon dioxide gas impairs respiratory function, and so on, the growth of roots is hindered. There was a risk of withering.

Further, it has been proposed to use a waterproof synthetic resin film having a hole of several hundred μm or more by mechanical perforation as a film for cultivating agricultural products, and covering the soil surface with the perforated film. However, this product uses a perforated film with an average pore size of several hundreds of μm or more, so the evaporation of water vapor from the ground is effective, but when it rains, it also passes through rain, making the fruit watery and containing sugar. There are drawbacks such as a decrease in quantity, and there is a problem that the quality of agricultural products deteriorates.

By the way, after covering the soil surface with this perforated film, agricultural producers carry out agricultural work such as fruit picking, disinfection, pruning of windbreak forests, and branching. The perforated film has an average pore diameter of several Since it is as large as 100 μm or more,
The film is damaged during agricultural work, and the quality of the film varies due to infiltration of rainwater from the damaged part, and the sugar content decreases and the film becomes watery.

Therefore, recently, as a film for cultivating agricultural products, it is possible to obtain high-quality agricultural products which are excellent in moisture permeability, waterproofness and windproof property, and can effectively control the water content and carbon dioxide concentration in soil. From the viewpoint, a laminated film composed of a stretched porous film formed by stretching a non-porous film to form a porous film and a nonwoven fabric is receiving the most attention.

[0013]

In this agricultural film for cultivation of agricultural products, the stretchable porous film is a moisture-permeable and waterproof film, and the moisture and carbon dioxide concentrations in the soil are effectively controlled to obtain high-quality agricultural products. Although it is excellent in that it is a stretchable porous film, it is reinforced by a non-woven fabric because it is weak because it is porous because it is formed by stretching a non-porous film several times and it is easy to tear. There is a technical problem described below by using such a nonwoven fabric.

That is, the non-woven fabric has a sheet-like or web-like structure obtained by partially adhering or entanglement of an aggregate of fibers (short fibers or filaments) by means of mechanical, chemical or heating. The web is a sheet formed by laying and laying fibers.

The method for producing the non-woven fabric is roughly classified into a wet type and a dry type. This wet-laid nonwoven fabric is a mixture of staple staple fibers (generally having a length of 10 mm or less) and heat-sealing fibers, suspended uniformly in water, and then scooped up onto a wire mesh to form a sheet, When this is dried, the heat-sealing fibers are melted and partially bonded, while the dry non-woven fabric is arranged in the air in the transport direction, or the fibers are arranged randomly, and this is It is partially bonded by using a needle punch or the like. Therefore, the non-woven fabric is expensive because it is obtained through such a complicated process.

By the way, when covering the soil surface of agricultural products, especially fruits such as mandarin oranges with a film for cultivating agricultural products, the start of the covering is generally in early-stage Wenzhou or high sugar content, and it is extremely early in August. It is said to be in late July in Wenzhou, but even after covering the soil surface with the agricultural product cultivation film in this way, agricultural product producers still carry out agricultural work such as fruit picking, disinfection, pruning of windbreaks, and branching.

However, as described above, the non-woven fabric is obtained by partially adhering or heat-sealing short fibers and the like,
The strength, especially the tear strength, is weak, and therefore, when the agricultural product producer lays this agricultural film for cultivation on the soil surface and then performs agricultural work on this film, this film tears and breaks. The quality will vary due to the infiltration of rainwater, etc., the sugar content will decrease and it will become watery, so it will be necessary to repair the damaged part, and there is no point in laying a film, etc. However, there is a problem that the material cost increases.

Further, as described above, since the nonwoven fabric is expensive, the film for cultivating agricultural products becomes expensive, and the strength is insufficient, so that it can only be used once, and it is necessary to repair it every year or to repair it every year. There is also a problem from this point that the material cost becomes high.

The present invention prevents rainwater from entering the soil from the latter half of the growth to the maturation of agricultural products, especially fruits and vegetables, and allows the water vapor from the ground to be released freely into the soil. It is possible to obtain high-quality agricultural products by controlling water content, excellent moisture permeability, waterproofness and windproof property, and by improving soil temperature and controlling soil water content and carbon dioxide gas concentration. (EN) A porous laminated film for cultivating agricultural products, which has a high durability and has a very long life even if agricultural work is performed on the film, and a method for cultivating agricultural products using the same.

[0020]

In order to achieve the above object, in the porous laminate film for agricultural product cultivation of the present invention, a porous laminated film used for cultivation of agricultural products, wherein the porous laminated film is It is characterized by comprising a stretched porous film formed by stretching a non-porous film and a porous film formed by physical perforation other than stretching.

The present invention will be described in detail below. Agricultural products to which the present invention is applied include, but are not particularly limited to, fruits, fruit vegetables, and root vegetables particularly susceptible to soil moisture.

The above-mentioned fruits are not particularly limited, but specifically, for example, mandarin oranges, pears, grapes, peaches,
Examples include apples, persimmons, and chestnuts.

The above-mentioned fruits and vegetables are not particularly limited, but specific examples thereof include tomato, watermelon, melon and strawberry.

Further, the root vegetables are not particularly limited, but specific examples include radish, carrot or turnip.

A porous laminated film for agricultural product cultivation of the present invention comprises a waterproof stretchable porous film formed by stretching a non-porous film and a reinforcement formed by physical perforation other than stretching. It is not particularly limited as long as it is made of a laminated film of a porous film for use in the resin, and it may be formed of any synthetic resin such as thermosetting resin or thermoplastic resin, but it is moldable and economical. From the viewpoint of, a thermoplastic resin is desirable.

The thermoplastic resin is not particularly limited, but is, for example, at least one selected from the group consisting of polyethylene resin, polypropylene resin, polyester resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyamide resin and the like. Examples thereof include a single-layer film or a composite film formed of the above resin. Among them, a polyethylene resin and a polypropylene resin are most preferable because they are excellent in film production and processability and the production cost is low.

In forming a non-porous film using the above synthetic resin, a known method such as calendering, inflation, T-die method and solution method is used to form the non-porous film.

The non-porous film has a thickness of 10 to
It is preferable to set it in the range of 1000 μm, and if it is less than 10 μm, there is a problem that the film is too thin to break when applied to the soil surface where agricultural products are planted, or it is damaged during transportation or handling, On the other hand, if it exceeds 1000 μm, the strength becomes high, but the weight becomes heavy and the handleability is remarkably deteriorated, and it is uneconomical.
From these viewpoints, the thickness of 15 to 300 μm is most desirable.

If necessary, a filler is added to the non-porous film. The filler includes calcium carbonate, barium sulfate, kaolin sulfate, aluminum hydroxide, talc, clay, kaolin, silica, Zinc oxide,
Examples thereof include calcium oxide, titanium oxide, alumina and mica.

The filler having an average particle size of 0.1 to 50 μm is used. If the average particle size exceeds 50 μm, the dispersibility deteriorates. On the other hand, if the average particle size is less than 0.1 μm, dust is scattered during the work and the working environment deteriorates, which is not preferable.

In the above non-porous film, a synthetic resin,
The mixing ratio with the filler is 100 parts by weight of the synthetic resin,
It is desirable that the amount of the filler is 50 to 500 parts by weight, particularly 100 to 350, and such a blending ratio makes it possible to obtain a stretchable porous film and a stretchable film which will be described later and which have excellent mechanical strength, waterproofness and moisture permeability. A porous film for reinforcement formed by physical perforation other than the above can be easily manufactured.

The stretchable porous film used in the present invention is a porous film formed by uniaxially or biaxially stretching the above non-porous film, and is particularly limited as long as its average pore diameter is 30 μm or less. It is not something that will be done.

The most significant feature of the present invention is that the stretched porous film is reinforced with a porous film. The porous film is obtained by physical perforation other than stretching of the non-porous film. There is a point formed.

That is, since the stretchable porous film is formed by stretching a non-porous film several times to have a porous structure, the strength is extremely weak and it is easy to tear. When an agricultural work is performed on this film after laying, the film is torn and broken, which causes various problems.

Therefore, when reinforcing the stretched porous film, a study was repeatedly conducted on a film which was economical and exhibited an excellent reinforcing effect. As a result, a non-porous film was formed by physical perforation other than stretching. The quality film is extremely high in strength, hard to tear, and inexpensive, and after laying on the soil surface the porous laminated film for agricultural product cultivation formed by reinforcing the stretchable porous film with this porous film, It was confirmed that the film was not easily torn and torn even when the work was carried out, and that the farm work could be carried out with peace of mind, and that there was no abnormality even when it was used for 3 years.

Thus, in forming a porous film by physical perforation other than stretching of a non-porous film,
This porous film has an average pore size of 0.2 to 100 μm.
What is formed in the is desirable.

The average pore size of this porous film was 0.2
If it is less than μm, the water vapor permeability becomes low and the water content in the ground rises and may accumulate on the lower surface of the film. As a result, the roots of agricultural products in the ground may look upward for water, or the upper layers of the ground. The root vigor may be impaired because the root growth may be hindered due to over-humidity and root rot, while 100 μm
If it exceeds, the strength is lowered and the film may be damaged during agricultural work, which is not desirable.

The physical perforations are not particularly limited as long as they are other than stretching and are capable of physically forming through-holes having an average pore diameter of 0.2 to 100 μm, but specifically, Examples thereof include perforation with fine diamond powder, needle perforation, corona discharge, electron beam irradiation or plasma discharge.

A method for forming a non-perforated film by perforation with fine diamond powder is described in JP-A-4-2499.
As described in Japanese Patent Publication No. JP-A-2003-264, the whole surface of a non-porous film is coated with a diamond powder such as a fine artificial diamond powder (having an average particle size of 100 μm or less) on one of a pair of pressure rollers. A method of passing a non-perforated film between the pair of pressure rollers to form a through hole may be mentioned.

As the needle perforation, a large number of needle plates having a diameter of 100 μm or less are used, and these are pressed against the entire surface of the non-perforated film to form through holes.

As the corona treatment, generally, in the atmosphere, a non-porous film has a power density of 30 to 1000 W / m ² ·.
It is processed in the range of minutes to form through holes having an average pore diameter of 100 μm or less.

The above electron beam irradiation means that the non-porous film is irradiated with an electron beam of 1 to 30 Mrad so that the average pore diameter is 100 μm.
A through hole of m or less is formed.

The above-mentioned plasma discharge means that the non-porous film is treated by glow discharge in a vacuum so that the average pore size is 100 μm.
A through hole of m or less is formed.

The laminated film for cultivating agricultural products of the present invention is obtained by stacking the stretched porous film and the porous film on each other and heat-sealing them.

It is desirable that the area of the heat-sealed portion is formed substantially uniformly over the entire surface in the range of 5 to 35%, preferably 10 to 20% of the area of the film. If the area of the heat-bonded portion is less than 5%, the melt-bonded area between the films may be too small, and delamination may partially occur. On the other hand, 35%
If it exceeds the range, the water vapor transmission rate decreases, and as a result, there is a possibility that the agricultural products may vary, which is not preferable.

By the way, the area of the heat-sealed portion can be adjusted very easily by, for example, the ratio of the convex portions in the heated metal concave-convex roll.

That is, when a film is passed between heated metal concavo-convex rolls, the film comes into contact with the apexes of the convex portions of the metal concavo-convex roll, and the film is heat-sealed at the convex portions, At the recessed portion, there is no contact between the film and the metal concavo-convex roll, so that the film is not heat-sealed.

The laminated film for cultivating agricultural products of the present invention is formed by stacking the stretched porous film and the porous film and partially adhering them.

In this case, for the same reason as described above, the area of the bonding portion should be formed substantially uniformly over the entire surface in the range of 5 to 35%, preferably 10 to 20% of the area of the film. desirable.

By the way, the area of the adhesive portion may be formed by printing or the like so that the adhesive layer is formed substantially uniformly and partially over the entire surface of the film.

Examples of the adhesive layer include vinyl acetate adhesive, polyvinyl alcohol adhesive, polyvinyl acetal adhesive, vinyl chloride adhesive, acrylic adhesive, polyamide adhesive, polyethylene adhesive, cellulose. -Based adhesive, polyvinyl ether, chloroprene-based adhesive, nitrile rubber-based adhesive, styrene rubber-based adhesive, polysulfide-based adhesive, butyl rubber-based adhesive,
Examples include a layer formed of a silicone rubber-based pressure-sensitive adhesive, polyisobutylene, etc., and these pressure-sensitive adhesive layers are appropriately selected and used depending on the bonding partner such as a synthetic resin film.

Additives such as thickeners, emulsifiers, tackifiers, antioxidants, antioxidants, dyes and pigments are added to these adhesives, if desired.
It is used in the range of 0.1 to 300 parts by weight with respect to 100 parts by weight of the adhesive.

The thickness of the porous laminated film for cultivating agricultural products used in the present invention is preferably in the range of 15 to 1500 μm, and when it is less than 15 μm, the thickness of the film is too thin and the agricultural products are planted. There are problems such as tearing when applied to a surface, breakage during transportation, handling, etc. On the other hand, if it exceeds 1500 μm, strength increases but it becomes heavy and handling becomes significantly worse, and it is uneconomical, In any case, it is not preferable, and from these viewpoints,
The range of 20 to 500 μm is most desirable.

The laminated film for agricultural product cultivation of the present invention preferably has a water pressure resistance of 1000 mmH ₂ 0 or more. When the water pressure resistance is less than 1000 mmH ₂ 0, the film can be used when there is a large amount of rainfall such as a typhoon. It is not desirable because there is a risk that the rainwater collected above may permeate and be absorbed into the soil. Therefore, from these viewpoints, the water pressure resistance is 2
000mmH ₂ 0 or more it is desirable.

[0055] Further, in the laminated film for agricultural cultivation of the present invention, it is desirable that moisture permeability is 1000~10000g / m ² · day, the moisture permeability is the soil moisture is less than 1000g / m ² · day It becomes high, and moisture accumulates on the back side of the film, making it difficult to control soil moisture.
If it exceeds 0000 g / m ² · day, the water permeability becomes too high and the soil becomes too dry, or the soil water becomes high, which makes it difficult to control the soil moisture.

Further, in the laminated film for cultivating agricultural products of the present invention, one having a puncture strength of 0.5 or more, particularly preferably 1 or more has good durability and handleability of the film, and has a useful life. It is useful because it is long.

The laminated film for agricultural product cultivation of the present invention can be obtained by superposing the stretched porous film and the porous film on each other and heat-sealing them partially or entirely.

In this case, when the whole is heat-sealed and the moisture permeability is too low, in the obtained laminated film for agricultural product cultivation, a part from the stretchable porous film side to the other porous film side It is sufficient to form a physical hole extending from the porous film side to a part of the other stretched type porous film side.

In the laminated film for cultivating agricultural products of the present invention, in order to achieve the above object, a stretched porous film and a non-porous film are joined together with a hot melt adhesive film interposed therebetween, A hot-melt adhesive film formed into a porous form by physical perforation other than stretching is also useful.

As the non-porous film and the stretchable porous film used in the present invention, the same ones as mentioned above can be mentioned.

The hot melt adhesive film is not particularly limited as long as it is made of a hot melt resin.

The hot-melt resin is not particularly limited as long as it exhibits adhesiveness by heating, but particularly, for example, ethylene-vinyl acetate copolymer resin or ethylene-isobutyl acrylate copolymer resin. Ethylene-acrylic acid ester copolymer resins such as ethylene-based hot melt resins and the like exhibit excellent adhesiveness, but among these, ethylene-vinyl acetate copolymer resins and ethylene-acrylic acid ester copolymer resins are particularly excellent. It is preferable because it has adhesive strength, is inexpensive, and is excellent in production and processability.

The hot melt adhesive film can be obtained by a known method.

According to the present invention, the stretchable porous film and the non-porous film are joined together with the hot-melt adhesive film interposed therebetween, and the non-porous film and the hot-melt adhesive film are subjected to physical perforation other than stretching. Although it has a great feature in that it is made porous by the above method, the method of physical perforation includes the above-mentioned ones.

In this case, the non-perforated film and the hot-melt adhesive film are formed porous by physical perforation, and those having an average pore diameter of 0.2 to 100 μm are the same as in the above case. Beneficial for a reason. Examples of the method for this physical perforation include those mentioned above.

The thickness of the porous laminated film for cultivating agricultural products used in the present invention is preferably in the range of 15 to 1500 μm, and if it is less than 15 μm, the thickness of the film is too thin so that the agricultural products are planted. There are problems such as tearing when applied to a surface, breakage during transportation, handling, etc. On the other hand, if it exceeds 1500 μm, strength increases but it becomes heavy and handling becomes significantly worse, and it is uneconomical, In any case, it is not preferable, and from these viewpoints,
The range of 20 to 500 μm is most desirable.

[0067] In this agricultural cultivation laminated film, water pressure resistance 1000mmH ₂ 0 or more, particularly 2000m
Those having mH ₂ O or more are useful for the same reason as described above.

Further, in the porous laminated film for agricultural product cultivation of the present invention, the water vapor permeability is 1000 to 10000 g / m ^2.
・ For the same reason as above, what is day is
Be beneficial.

Furthermore, in the porous laminated film for agricultural product cultivation of the present invention, the puncture strength is 0.5 or more, particularly 1
The above is useful for the same reason as described above.

In this case, when the whole is heat-sealed and the moisture permeability is too low, in the obtained laminated film for agricultural product cultivation, a part from the stretchable porous film side to the other porous film side It is sufficient to form a physical hole extending from the porous film side to a part of the other stretched type porous film side.

The above-mentioned porous laminated film for cultivation of agricultural products may be added with an antioxidant, an ultraviolet stabilizer, an antistatic agent, a lubricant, a fluorescent agent and the like which are usually used.

In the method for cultivating an agricultural product of the present invention, in order to achieve the above object, an agricultural product is cultivated by using the above-mentioned porous laminated film for cultivating an agricultural product. As a result, the agricultural product is matured from the latter half of its growth. By controlling the soil water content, raising the soil temperature, and controlling the carbon dioxide concentration in the soil over a period of time, high quality agricultural products can be obtained and it can be used for a long period of time.

[0073]

In the porous laminate film for cultivating agricultural products of the present invention, by covering the soil surface on which the agricultural products are planted, rainwater from the latter half of the growing period to the mature period of the agricultural products enters the soil. To prevent soil and control the soil moisture by freely releasing water vapor from the ground into the air, and it has excellent moisture permeability, waterproofness and windproof property, and also improves soil temperature and soil moisture and carbon dioxide concentration. It has the effect that high quality agricultural products can be obtained.

Moreover, in this agricultural product cultivating porous laminated film, the stretchable porous film formed by stretching the non-porous film is reinforced with the porous film formed by physical perforation other than stretching. Since this porous film is formed by physically forming fine through-holes on the entire surface of the film, its strength is extremely high, and even if agricultural work is performed on the film, the damage is extremely small,
It has the effect of significantly increasing the service life.

In the method for cultivating an agricultural product of the present invention, an agricultural product is cultivated using the porous laminated film for cultivating an agricultural product of the present invention. As a result, soil water content is increased from the latter half of the growing period to the mature period of the agricultural product. It is possible to manage, raise the soil temperature, control the carbon dioxide concentration in the soil, obtain high quality agricultural products, and use it for a long period of time, and since this film has extremely high strength, Even after the soil surface is covered with the film, the producer of the agricultural product does not cause damage or tearing of the film even if it is used for agricultural work such as fruit picking, disinfection, pruning of windbreak forest, and branching.

[0076]

EXAMPLES The present invention will now be described in detail based on examples, but the present invention is not limited thereto.

Example 1 Production of non-porous film 100 parts by weight of a linear low-density polyethylene resin (density 0.90) was added to calcium carbonate (average particle size 1.2) as a filler.
(100 μm) and 15 parts by weight of butadiene rubber were uniformly kneaded with a Banbury mixer and then pelletized with a pelletizer. 5 of these pellets
Extrusion molding with 0mmT die extrusion molding equipment, thickness 100
A film of μm was obtained.

Production of Stretched Porous Film The non-porous film obtained above was stretched uniaxially at 80 ° C. by a roll stretch molding device to prepare a stretched film having a stretch ratio of 2.0. It was confirmed that the stretched porous film obtained had no stretching unevenness and was made porous (average pore size: about 0.75 μm).

Production of Porous Film To form physically fine through-holes on the entire surface of the non-porous film obtained above, one roller of a pair of pressure rollers was fine (average particle diameter was 60 μm). The artificial diamond powder was coated, and a non-perforated film was passed between the pair of pressing rollers to form a through hole.

Production of porous laminated film for cultivation of agricultural products
The above - mentioned films were laminated and passed between heated metal concavo-convex rolls to heat-bond 15% of the total area of the films.

The heat-fusing area of this film was adjusted by the area of the protrusions on the metal concavo-convex roll.

Table 1 shows the physical properties of the porous laminated film for cultivating agricultural products.

Example 2 In the same manner as in Example 1 except that the stretchable porous film used in Example 1 had a draw ratio of 3 times.
A porous laminated film for agricultural product cultivation was obtained. The average pore size of this stretchable porous film was about 2.0 μm. Table 1 shows the physical properties of this porous laminated film for agricultural product cultivation.
Shown in.

Example 3 In Example 1, as the porous film, a perforated film was pressed by pressing an ultrafine needle plate over the entire surface of the non-porous film (average hole diameter: 30 μm).
A porous laminated film for agricultural product cultivation was obtained in the same manner as in Example 1 except that the above-mentioned product was used. The physical properties of this porous laminated film for agricultural product cultivation are shown in Table 1.

Example 4 The pellets obtained in Example 1 and the pellets of the hot-melt resin composition described below were coextruded with a two-layer extruder to obtain a linear low-density polyethylene resin film and a hot-melt resin. Laminated film (thickness 50μ
m) was obtained.

That is, 100 parts by weight of ethylene-vinyl acetate copolymer resin (vinyl acetate content 25% by weight, density 0.95) and calcium carbonate (average particle size 1.2 μm) 150 parts by weight as a hot melt resin. Was thoroughly mixed by stirring, the composition was uniformly kneaded with a Banbury mixer, and then pelletized with a pelletizer.

The stretched porous film obtained in Example 1 was overlaid on the hot melt adhesive film side of this laminate, and both were heat-bonded in the same manner as in Example 1.

Then, by the same physical perforation as in Example 1, a non-porous film (polyethylene resin film) and a hot-melt adhesive film were formed into a porous structure to obtain a porous laminated film for agricultural product cultivation. ..

Table 1 shows the physical properties of this porous laminated film for agricultural product cultivation.

Comparative Example The stretched porous film obtained in Example 1 and a thickness of 100 μm
A polyethylene non-woven fabric of m was superposed, and 15% of the total area of the film was heat-sealed as a sample in the same manner as in Example 1.

Table 1 shows the physical properties of the film for cultivating agricultural products.

[0092]

[Table 1]

Note 1) In Table 1, water pressure resistance is JIS
It was measured by L 1092 (hydrostatic pressure method of Method B).

Note 2) In Table 1, the water vapor transmission rate is JIS L
It was measured by the method according to 1099.

Note 3) In Table 1, the puncture strength was determined by fixing each Example and Comparative Example by sticking them to the upper end of a pipe (diameter 50 mm).
m) was lowered at a speed of 200 mm / min, and the strength (Kg) when piercing each sample was shown.

Note 4) In Table 1, the tensile strength is the width 1c.
The film of m was stretched in the stretching direction to measure the strength.

Examples 1 to 4 Using each of the obtained Examples and Comparative Examples, this was placed on a flat soil surface where Citrus unshiu (variety Yamakawa Hayao) is cultivated from July 26th to November 16th. The sugar content (sugar content) of the early-ripening Satsuma mandarin oranges after harvesting was measured. During this period, the agricultural product producer carried out a total of 12 farming operations on the film, such as fruit picking, disinfection, pruning of windbreak forests, and branching. The results are shown in Table 2.

Further, using each of the obtained Examples and Comparative Examples, this was laid on the soil surface where Satsuma mandarin orange (cultivar Yamakawa Hayao) was cultivated, and the carbon dioxide concentration was measured. The results are shown in Table 2.

[0099]

[Table 2]

Note 5) In Table 2, the sugar content was measured by the refractometer measurement. The number of samples was 10, and the average value was shown. In addition, in the comparative example, the sugar content was varied as described later, and the average value could not be shown.

Note 6) In Table 2, the CO ₂ concentration index is
A vinyl chloride pipe (φ20 mm) with a small hole formed in the vicinity of the dense root was wrapped with a kanreisha, and a vinyl chloride tube (φ5 mm) was attached and embedded. After 15 days, 1 ml (2 repetitions) of gas accumulated in the pipe was extracted and subjected to gas chromatography for measurement. The carbon dioxide concentration was measured using a Hitachi Gas Chromatograph 164 type: silica gel column (1 m) equipped with a thermal conductivity detector (TCD) at a column temperature of 90 ° C.
It was measured with He gas of 1.1 kg / cm ² .

Note 7) In Table 2, whether or not the film was damaged was determined by the producer of the agricultural product laying the film of each Example and Comparative Example on the soil surface, and picking, disinfecting, pruning the windbreak and pruning on the film. Agricultural work such as the above was performed 12 times in total, and then visually confirmed.

From the results shown in Table 2, the results of the examples are as follows:
No abnormalities were found in the sugar content and the condition of the fruit trees.

On the other hand, in the case of the comparative example, no abnormality was observed in the state of the fruit tree, but the damage of the film increased due to the agricultural work, and the sugar content varied from 8.5 to 12.2 (Brix%). It was great.

From the results shown in Table 2, no abnormality was found in the carbon dioxide concentration in the soil in any of the examples and the comparative examples.

From the results shown in Table 2, the puncture strength of the example is as high as 0.65 kg or more, and even if the pebbles are scattered on the soil surface, breakage occurs even when the agricultural producer walks on it. It is recognized that there is no fear of

On the other hand, in the case of the comparative example, the puncture strength was as low as 0.35 Kg, and it was recognized that if small stones are scattered on the soil surface, a crack may occur when the agricultural product producer walks on it. Be done.

From the results shown in Table 2, in the examples, no abnormalities such as film damage were observed, but in the comparative examples, several small tears were observed in the first farm work, and the number of farm work was It was recognized that the number of cracks increased as the number increased.

[0109]

The porous laminated film for agricultural product cultivation of the present invention has the above-mentioned constitution, and by covering the soil surface on which the agricultural product is planted by using the film, the agricultural product can be grown from the latter half to the mature stage. Prevents rainwater from entering the soil, promotes the growth of agricultural products, and controls soil moisture to prevent moisture from accumulating on the lower surface of the film and overhumidity of the soil. In addition to being excellent in wind resistance and wind resistance, high quality agricultural products can be effectively produced by improving soil temperature and controlling soil moisture and carbon dioxide concentration.

In addition, this porous laminated film for agricultural products is reinforced by a stretchable porous film formed by stretching a non-porous film by a porous film formed by physical perforation other than stretching. Since this porous film is formed by physically forming fine through-holes on the entire surface of the film, its tearing strength and piercing strength are remarkably high, and even if agricultural work is performed on the film, it will be significantly less damaged and durable. It is extremely economical because the number of years is significantly improved.

Further, in the method for cultivating agricultural products of the present invention, agricultural products are cultivated using the porous laminated film for cultivating agricultural products of the present invention, and as a result, soil moisture is removed from the latter half of the growing period to the mature period of the agricultural products. It is possible to manage, raise the soil temperature, control the carbon dioxide concentration in the soil, obtain high quality agricultural products, and use it for a long period of time, and since this film has extremely high strength, Even after the soil surface is covered with the film, the agricultural product producer does not damage or tear the film even if he or she performs agricultural work such as fruit picking, disinfection, pruning of windbreak forest, and branching, which is extremely economical.

Claims (13)

[Claims] 1. A porous laminated film used for cultivating agricultural products, wherein the porous laminated film is a stretched porous film formed by stretching a non-porous film and a physical layer other than the stretched non-porous film. A porous laminated film for agricultural product cultivation, comprising a porous film formed by mechanical perforation. 2. The porous fill is formed by physical perforation.
The porous laminated film for agricultural product cultivation according to claim 1, which has an average pore size of 0.5 to 100 μm. Wherein for agricultural cultivation porous laminate film according to claim 1 or 2 water pressure is 1000MmH ₂ 0 or more. 4. A moisture vapor transmission rate of 1,000 to 10,000 g / m ² · day.
The porous laminated film for agricultural product cultivation according to any one of claims 1 to 3. 5. The piercing strength is 0.5 or more.
The porous laminated film for agricultural product cultivation according to any one of 1 to 4. 6. The porous laminated film for agricultural product cultivation according to claim 1, wherein the stretched porous film and the porous film are formed by heat fusion. 7. The stretchable porous film and the porous film are formed by partial adhesion.
The porous laminated film for agricultural product cultivation according to any one of 1. 8. A stretchable porous film and a non-porous film are joined together with a hot melt adhesive film interposed therebetween, and the non-porous film and hot melt adhesive film are made porous by physical perforation other than stretching. The formed porous laminated film for agricultural product cultivation. 9. The porous film and the hot-melt adhesive film have an average pore diameter of 0.5 to 1 by physical perforation.
The porous laminated film for agricultural product cultivation according to claim 8, having a thickness of 00 μm. 10. A porous laminated film for agricultural cultivation according to claim 8 or 9 water pressure is 1000mmH ₂ 0 or more. 11. A water vapor transmission rate of 1,000 to 10,000 g / m ² · d.
The porous laminated film for agricultural product cultivation according to any one of claims 8 to 10, which is ay. 12. The porous laminated film for cultivating agricultural products according to claim 8, which has a puncture strength of 0.5 or more. 13. The porous laminate for agricultural product cultivation according to claim 1, wherein the porous film is formed by perforation with fine diamond powder, needle perforation, corona discharge, electron beam irradiation or plasma discharge. the film. 14. A method for cultivating an agricultural product, which comprises cultivating an agricultural product using the porous laminated film for cultivating an agricultural product according to any one of claims 1 to 13.