JPH08205694A - Film for plant culture and culture of plant - Google Patents

Abstract

PURPOSE: To provide a plant-culturing film which can prevent fruits or fruit vegetable from uneven coloring and shows excellent weathering resistance to ultraviolet rays, and a plant-culturing method using the film. CONSTITUTION: Previously, a porous film having a rate of hole area of 40-70% and >=95% diffusion reflectance at 550nm is prepared by orienting at least in one direction a polymer comprising 100 pts.wt. of a polyolefin resin and 100-300 pts.wt. of fine particles of an inorganic filler having 0.1-7μm average particle size and 0.1-0.5 pt.wt. of an ultraviolet absorbing agent at a draw ratio of 2-8 times. At least one surface of this porous film is laminated with a non- porous film which contains 100 pts.wt. of a polyolefin resin and 0.1-0.5 pt.wt. of an ultraviolet absorbing agent. The resultant objective film has a total luminous transmission of 80% or higher. Further, plants are cultured using this film.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a film for cultivating plants and a method for cultivating plants using the film. Specifically, a film for plant cultivation in which a non-porous film is laminated on at least one surface of a porous film, and a plant covering a soil surface planted with a plant with the non-porous film surface of the film as the front side. Regarding cultivation method. According to the present invention,
Coloring of the epidermis of fruits and vegetables can be promoted, uneven coloring can be prevented, and the non-porous film layer blocks ultraviolet rays and the like, so that it has good weather resistance and can withstand long-term use.

[0002]

2. Description of the Related Art Conventionally, many improvement methods have been proposed, such as improving the coloration of the epidermis of agricultural crops such as fruits and fruits and vegetables, and preventing uneven coloring. JP-B-57-21963 discloses that a sheet or film obtained by blending 100 parts by weight of a polyolefin resin with 5 to 30 parts by weight of a fine powdery inorganic substance is uniaxially or biaxially stretched to have a porosity of 25 to 60.
A sheet or film for improving fruit quality in% is disclosed. The sheet or film is a sheet or film that does not cause the phenomenon of overheating of fruits, lowering of geothermal heat, etc. by selectively absorbing or reflecting sun rays when laid under the bottoms of fruit trees or net shelves. Are described as being sheets or films capable of improving quality. However, since the sheet or film is a stretched polyolefin-based porous resin sheet or film, it has low light resistance to ultraviolet rays and the like, and when exposed to sunlight or the like, its strength decreases and it breaks. There is a drawback that it cannot withstand long-term use. Further, the content of the fine powdery inorganic substance is 30 parts by weight at the maximum, and it is necessary to increase the stretching ratio in order to obtain a porous resin sheet or film having a high porosity, and the film may be broken during stretching. I have a problem.

In Japanese Utility Model Laid-Open No. 59-47454, a through hole is provided in a laminated sheet of a thermoplastic synthetic resin film, a metal thin film layer, and a thermoplastic synthetic resin substrate, and a metal thin film layer appearing inside the hole is heated. An agricultural light reflecting sheet coated with a plastic synthetic resin substrate is disclosed. However, the agricultural light-reflecting sheet has a drawback that the reflected light is difficult to diffuse because the thin metal film layer is mainly used as the light-reflecting layer. Therefore, there is a drawback that the amount of reflected light applied to the epidermis of fruits, fruits and vegetables has a distribution, and the degree of coloring of the epidermis of fruits, fruits and vegetables easily becomes uneven.

Further, in Japanese Unexamined Patent Publication No. 5-268840, air permeability is 200 to 5 due to formation of fine pores.
000 seconds / 100 ml, water pressure resistance is 500 mmH
₂ O or more, water vapor permeability 1000 to 10,000 gH ₂ O / m
And ² · 24 hr or a synthetic resin porous film or sheet, the apertures having a pore size 1mm~10cm has features and 1% to 50% synthetic resin porous film or sheet provided in the area ratio in the longitudinal direction Disclosed is a film or sheet for cultivating fruit plants, which is used for covering the ground surface around the roots of woody or herbaceous fruit plants. However, the film or sheet for cultivating fruits and vegetables has a porous film or sheet made of synthetic resin and a pore diameter of 1 mm to 10 c.
Since a synthetic resin perforated film or sheet having m openings is laminated, sunlight is directly radiated from the perforated film or sheet to the porous film or sheet. However, there is a drawback that the porous film or sheet is deteriorated by exposure to the above and cannot be used for a long time.

[0005]

The problems to be solved by the present invention are as follows.
An object of the present invention is to provide a film for plant cultivation, which solves the above problems, promotes coloring of the epidermis of fruits and vegetables, prevents uneven coloring, and has excellent weather resistance against ultraviolet rays and the like. Another problem to be solved by the present invention is to provide a method for cultivating a plant using the film for cultivating a plant.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that a laminated film in which a nonporous film is laminated on at least one surface of a specific porous film can solve the above problems. The inventors have found that the film is a film for plant cultivation that can be solved, and arrived at the present invention.

That is, the present invention is a film for plant cultivation in which a non-porous film is laminated on at least one surface of a porous film, wherein the porous film comprises 100 parts by weight of a polyolefin resin and an average particle size of 0. 100 to 300 parts by weight of a finely powdered inorganic filler of 1 to 7 μm and 0.1 to 0.5 parts by weight of an ultraviolet absorber, and 2 to at least one axial direction.
8 times stretched, porosity 40-70%, wavelength 550nm
Is a porous film having a diffuse reflectance of 95% or more, wherein the non-porous film contains 100 parts by weight of a polyolefin resin and 0.1 to 0.5 parts by weight of an ultraviolet absorber, and has a total light transmittance of 80%. It is a film for plant cultivation characterized by being the above resin film.

Another aspect of the present invention is a method for cultivating a plant, which comprises coating a soil surface with a laminated film in which a non-porous film is laminated on at least one surface of the porous film. The film is polyolefin resin 1
00 parts by weight, 100 to 300 parts by weight of a finely powdered inorganic filler having an average particle size of 0.1 to 7 μm, and an ultraviolet absorber of 0.1 to
A porous film which contains 0.5 parts by weight and is stretched at least uniaxially by a factor of 2 to 8 and has an aperture ratio of 40 to 70% and a diffuse reflectance at a wavelength of 550 nm of 95% or more. Contains 100 parts by weight of a polyolefin resin and 0.1 to 0.5 parts by weight of an ultraviolet absorber, and has a total light transmittance of 8
A method of cultivating a plant, which comprises 0% or more of a resin film and covers the soil surface with the non-porous film surface of the laminated film as the front side.

Examples of plants to which the present invention can be applied include fruits, fruits and vegetables, fruits and vegetables, and are not particularly limited. Specifically, fruit trees of fruits such as mandarin oranges, apples, pears, grapes, oysters, chestnuts, walnuts, figs, peaches,
Examples include fruit crops such as strawberry, tomato, eggplant, watermelon, cucumber, green onion, myoga, and melon. It can also be applied to the cultivation of other flowers.

The porous film used in the film for plant cultivation of the present invention is obtained by adding and mixing a specific amount of a finely powdered inorganic filler and an ultraviolet absorber to a polyolefin resin to form a resin composition, and melting the resin composition. It is manufactured by forming an unstretched film by molding and then stretching the obtained unstretched film in at least one uniaxial direction. Further, the non-porous film used in the film for plant cultivation of the present invention, a specific amount of the ultraviolet absorber is added to the polyolefin resin, and mixed to form a resin composition, which is produced by melt molding the resin composition. It Thus, the film for plant cultivation of the present invention is produced by laminating the non-porous film on at least one surface of the porous film. Hereinafter, the present invention will be described in detail.

A polyolefin resin is used as the base resin of the porous film used in the present invention. Examples of the polyolefin resin include high-density polyethylene, low-density polyethylene, linear low-density polyethylene that is a copolymer of ethylene and α-olefin, polypropylene, ethylene-propylene copolymer, poly-4-methylpentene resin, and the like. . Among these resins, in consideration of the mixing / dispersing property with a finely powdered inorganic filler, the moldability of the film, the stretchability, etc., linear low density polyethylene (hereinafter referred to as LLDPE) which is a copolymer of ethylene and α-olefin. (Abbreviated) is preferred.

Examples of finely powdered inorganic fillers added to the porous film include barium sulfate and calcium carbonate. Considering the miscibility with the polyolefin resin, the pore size of the porous film, the stretchability, etc., the average particle size of the finely powdered inorganic filler is preferably about 0.1 to 7 μm. The amount of the finely divided inorganic filler added affects the stretchability, the porosity of the resulting porous film, and the like. If the amount added is too small, the porosity of the resulting porous film will be low and high reflectance cannot be obtained. As a result, the effect of improving the coloring of the epidermis of fruits and vegetables decreases. On the other hand, if the amount is too large, the film may be broken during stretching, resulting in poor productivity. Considering this point, the addition amount of the fine powder inorganic filler is preferably 100 to 300 parts by weight with respect to 100 parts by weight of the polyolefin resin.

An ultraviolet absorber is added to the porous film for the purpose of imparting weather resistance to ultraviolet rays and the like. If the amount of the ultraviolet absorber added is small, the weather resistance against ultraviolet rays becomes insufficient, and if it is too large, there arises a problem that the hue of the film decreases. From this viewpoint, the amount of the ultraviolet absorber added is preferably 0.1 to 0.5 parts by weight with respect to 100 parts by weight of the polyolefin resin. It is more preferably 0.2 to 0.4 parts by weight.

As these ultraviolet absorbers, 2,4-
Dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-
Methoxybenzophenone, 2,2'-dihydroxy-
4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2
-Hydroxy-4-n-octoxybenzophenone,
2,2 ′, 4,4′-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, bis (5-benzoyl-4-hydroxy-2-2
Benzophenone compounds such as (methoxyphenyl) methane, 2- (2′-hydroxy-5′-methylphenyl)
Benzotriazole, 2- (2'-hydroxy-3'-
5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3) '5'-ge-t
ert-Butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-amyl Phenol) benzotriazole, 2- [2'-hydroxy-
3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl] benzotriazole, 2-2'-methylenebis [4- (1,1,3,3)
3-Tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] and other UV absorbers represented by benzotriazole compounds.

Other additives such as a softening agent, a stabilizer, a lubricant, a dispersant, a white pigment and an optical brightening agent may be added to the porous film so long as the object of the present invention is not impaired.

There is no particular limitation on the method for producing the resin composition by adding the above-mentioned finely powdered inorganic filler, ultraviolet absorber and, if necessary, other additives to the polyolefin resin, and known methods are available. Applicable. For example, a method of mixing at room temperature or a temperature in the vicinity thereof using a ribbon blender, a Henschel mixer, a super mixer, a tumbler mixer and the like can be mentioned. Moreover, after mixing, using a single-screw or twin-screw extruder equipped with a strand die, the melting point or softening temperature of the polyolefin resin or higher, preferably the melting point or softening temperature + 20 ° C. or higher,
There is also a method of kneading and melt-extruding in a temperature range lower than the decomposition temperature of the polyolefin resin to form a molten strand, cooling, and then cutting and molding into a pellet.
In order to uniformly disperse and mix the polyolefin resin and the finely powdered inorganic filler, a method of molding into pellets is preferable. If it can be dispersed uniformly, a porous film having a high reflectance due to high scattering will be obtained as a result, and the effects of improving the coloring of the epidermis of the epidermis of fruits and fruits and vegetables and preventing uneven coloring will be further enhanced.

The method for producing an unstretched film from the above resin composition is not particularly limited, and known methods can be applied. For example, known methods such as an extrusion molding method using a single-screw or twin-screw extruder equipped with a T die, an inflation molding method using an extruder equipped with a circular die, and a calender molding method can be mentioned.

The molding temperature of the unstretched film varies depending on the polyolefin resin used, but is usually a temperature above the melting point or softening point of the resin used, preferably within the temperature range above the melting point or softening point + 20 ° C and below the decomposition temperature. is there.
The obtained unstretched resin sheet is stretched in at least uniaxial direction by a known method such as a roll method or a tenter method. The stretching may be carried out in one stage or may be carried out in multiple stages. Further, it may be biaxially stretched. Further, after stretching, if necessary, a heat setting treatment may be performed to stabilize the shape of the obtained pores.

In order to prevent the sheet from being cut during stretching and to perform uniform stretching and obtain a porous resin sheet having a preferable porosity, the stretching temperature is the Vicat softening point (JIS K-6760) of the resin. It is preferably less than the value measured by the method defined in 1.). In addition, the draw ratio affects the porosity of the obtained stretched film, similarly to the amount of the finely powdered inorganic filler added. If the stretching ratio is low, the porosity of the obtained stretched film is lowered, and the effect of improving coloring of the epidermis of fruits and the like is lowered. If the stretching ratio is too high, the film may be cut during stretching, which is not preferable.
From this point of view, the draw ratio is at least 2 in the uniaxial direction
A range of 8 times is preferable. More preferably, it is 3 to 8 times. In the case of biaxial stretching, it is 1.3 in the uniaxial direction.
It is preferable to stretch by 4 to 4 times, and 1.1 to 3 times in the direction perpendicular to that direction.

If the thickness of the porous film is thin, the light transmittance tends to increase and the diffuse reflectance of light rays tends to decrease. As a result, the effect of promoting coloring of the epidermis of fruits, fruits and vegetables and preventing uneven coloring is reduced. When it is thick, the diffuse reflectance of light does not change, but the productivity of the porous film decreases. Therefore, the thickness of the porous sheet used in the present invention is about 20 to 200 μm. Preferably 50 to 1
It is 00 μm. If it is less than 20 μm, the diffuse reflectance decreases, and as a result, the coloring of the epidermis of fruits, fruits and vegetables is improved,
The effect of preventing uneven coloring is reduced. Even if the thickness exceeds 200 μm, it cannot be expected that the diffuse reflectance will be improved due to the increased thickness. The porous film obtained as described above has a large number of fine pores having an average pore diameter of about 0.5 to 7 μm. When the average pore diameter is within the above range, a high diffuse reflectance is obtained, which is useful for improving the degree of coloring of the epidermis such as fruits and preventing coloring unevenness.

The porous film obtained as described above is a porous film having a porosity of 40 to 70%. In order to use the porous film as a film for plant cultivation, it is desired to have a high diffuse reflectance. When the porosity of the porous film is less than 40%, the interface between the resin layer and the air (pore) layer is reduced, so that the diffuse reflectance of light rays is reduced. Therefore, it is preferable that the porous film has a porosity of at least 40% or more and a diffuse reflectance of light having a wavelength of 550 nm is 95% or more. The higher the porosity of the porous film, the more preferable, but the upper limit is preferably about 70% in consideration of the formability and stretchability of the stretched film. Therefore, a preferred porous film has a porosity in the range of 40 to 70% among the porous films obtained by the above method, and
The diffuse reflectance of light having a wavelength of 550 nm is 95% or more.

As the non-porous film to be laminated on at least one surface of the porous film, for example, a polyolefin resin composition containing an ultraviolet absorber is extruded using a single-screw or twin-screw extruder equipped with a T-die. Law,
Examples thereof include a polyolefin resin film formed by a known method such as an inflation molding method using an extruder equipped with a circular die and a calender molding method.

The polyolefin resin used for producing the non-porous film is the same as the above-mentioned polyolefin resin used for producing the porous film. Specifically, high density polyethylene, low density polyethylene,
Examples thereof include linear low-density polyethylene, polypropylene, ethylene-propylene copolymer, poly-4-methylpentene resin, and the like, which are copolymers of ethylene and α-olefin. Of these polyolefin resins, LLDPE, which is a copolymer of ethylene and α-olefin, is preferable in view of the moldability of the film, the stretchability of the obtained film, the cost, and the like.

An ultraviolet absorber is added in order to improve the weather resistance of the non-porous fimul against ultraviolet rays and the like. The addition amount of the ultraviolet absorber is preferably 0.1 to 0.5 parts by weight with respect to 100 parts by weight of the polyolefin resin. It is more preferably 0.2 to 0.4 parts by weight. If it is out of this range, the weather resistance of the non-porous film is lowered and the hue is lowered, which is not preferable. As an ultraviolet absorber,
The same UV absorbers as those used in the production of the porous film are used. Other additives such as a softening agent, a stabilizer, a lubricant, a dispersant, and an optical brightening agent may be added to the non-porous film as long as the object of the present invention is not impaired.

There are no particular restrictions on the method for producing the resin composition by adding the above-mentioned ultraviolet absorber and, if necessary, other additives to the polyolefin resin, and known methods can be applied. For example, a method of mixing at room temperature or a temperature in the vicinity thereof using a ribbon blender, a Henschel mixer, a super mixer, a tumbler mixer and the like can be mentioned. Further, after mixing, using a single-screw or twin-screw extruder equipped with a strand die, the melting point or softening temperature of the polyolefin resin or higher, preferably the melting point or softening temperature + 20 ° C. or higher, lower than the decomposition temperature of the polyolefin resin There is also a method of kneading and melt-extruding in a temperature range to form a molten strand, cooling, and then cutting and forming into pellets. In order to uniformly disperse and mix the polyolefin resin and the ultraviolet absorber, a method of forming into pellets is preferable.

The method for producing a non-porous film from the above resin composition is not particularly limited, and known methods can be applied. For example, known methods such as an extrusion molding method using a single-screw or twin-screw extruder equipped with a T die, an inflation molding method using an extruder equipped with a circular die, and a calender molding method can be mentioned. Of these, the inflation molding method is preferable in consideration of balancing the longitudinal and lateral strengths of the obtained non-porous film. The molding temperature of the non-porous film varies depending on the polyolefin resin used, but is usually a temperature above the melting point or softening point of the resin used, preferably the melting point or softening point + 20 ° C.
As described above, the temperature range is lower than the decomposition temperature.

The non-porous film may be a uniaxially or biaxially stretched film. The draw ratio may be at least about 1.1 to 8 in the uniaxial direction. The thickness of the non-porous film affects the weather resistance and strength of the obtained film for plant cultivation. If the thickness is too thin, the weather resistance, strength, etc. will decrease, and if it is too thick, the weight will be heavy when spread on the surface of the soil in which fruit trees are planted and the workability will be poor. Considering this point, the thickness of the non-porous film is preferably 10 to 200 μm. More preferably, it is 20 to 100 μm.

The film for cultivating plants of the present invention comprises at least one surface of the porous film obtained as described above,
It is manufactured by laminating the non-porous films obtained as described above. Examples of the method for laminating the both include a method of bonding using various adhesives and a method of heat fusion.

The film for plant cultivation is exposed to sunlight.
Has excellent weather resistance against exposure to ultraviolet rays, etc.
Is required. If the weather resistance is low, the porous layer that is the reflective layer
At the interface between the resin and micropores in the layer
The light reflectivity of the
It is not preferable in terms of preventing uneven coloring. From this perspective,
80 ℃ on the non-porous film side surface of the film for plant cultivation
At 400 MJ / m ²The plant after irradiating with the ultraviolet rays of
The tensile breaking strength of the film for cultivation is
It is preferable that the tensile breaking strength is 0.995 or more.
Yes. The plant cultivation phy of the present invention produced as described above.
Rum is both a porous film layer and a non-porous film layer.
Since it contains a certain amount of UV absorber,
It has weather resistance to exposure to lines and the like.

Next, a method for cultivating a plant by covering the soil surface on which trees such as fruits and vegetables are planted with the film for cultivating plants obtained as described above will be described. The surface of the soil on which the trees of fruits and vegetables are planted is coated with the film for plant cultivation of the present invention.
In the case of annual plants such as strawberries and tomatoes, they may be coated from the beginning of planting to the harvest time. In the case of fruit trees such as apples, figs and tangerines, the covering may be continued until the next year. However, in any case, it is necessary that the fruits are attached after flowering, and at least the fruits and the fruits and vegetables are covered when they are in the enlargement stage and the ripening stage.

The covering area may be any surface of the soil in the range in which the sun rays reflected by the film for plant cultivation are irradiated on fruits and vegetables. When the non-porous film is laminated on both the front and back surfaces of the porous film, the front and back relationship of the plant cultivation film at the time of coating does not matter. However, when a non-porous film is laminated on one surface of the porous film, it is necessary to lay it on the soil surface so that the porous film layer is in contact with the soil surface and the non-porous film is on the front side. When supplying water to the soil or when it is desired to infiltrate the rain into the soil, the non-covered portion may be provided within a range in which the reflection effect is not significantly reduced.

Thus, the non-porous film layer functions as a barrier layer against ultraviolet rays and the like, and prevents deterioration of the porous film, which is the reflective layer, due to exposure to ultraviolet rays and the like. The non-porous film also has a function as a reinforcing material. It is possible to prevent breakage due to stress or the like at the time of spreading and covering the plant cultivation film on the soil surface, and breakage due to stress or the like when an operator or the like walks on the covered plant cultivation film. Further, the film for plant cultivation of the present invention also has a function of retaining heat and water of soil.

In the film for plant cultivation of the present invention, since the main reflection layer of light rays is a porous film, the reflected light rays irradiated to fruits and fruits are mainly diffused light. That is, the sunlight or the like applied to the plant cultivation film is partially reflected on the surface of the non-porous film laminated on the surface thereof, and is applied to fruits and vegetables. However, most of the light rays pass through the non-porous film layer to reach the porous film layer, and are reflected at the interface between a large number of micropores existing on the surface and inside and the resin layer, and again the non-porous film layer. And the fruits and vegetables are irradiated. Since light is reflected diffusely by the porous film layer, the fruits and vegetables are not irradiated locally but are irradiated from multiple directions.
Therefore, the light rays are not applied only to the upper side of the fruits and vegetables that are present on the fruit tree surface, but the light rays are evenly distributed to the lower side (shadow area) of the fruits and fruits and vegetables, and to the parts of the tree crown where the light rays are poor. It is extremely effective in promoting coloring of the epidermis of fruits and fruits and vegetables and preventing uneven coloring.

[0034]

EXAMPLES The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. Incidentally, the average pore diameter of the porous film, the opening ratio and diffuse reflectance, the total light transmittance of the non-porous film, the ultraviolet irradiation test of the film for plant cultivation, tensile breaking strength and tensile strength after ultraviolet irradiation and before ultraviolet irradiation The ratio of the tensile strength of is the value measured by the following method.

(1) Porosity (%) From the true specific gravity (A) of the resin composition used and the bulk specific gravity (B) of the obtained porous resin sheet, the numerical formula (1) [Equation 1]

[0036]

[Equation 1] The open area ratio (C) is calculated by.

(2) Average Pore Diameter (nm) The average pore diameter (nm) is measured using a pore size distribution measuring instrument [manufactured by Shimadzu Corporation, model: Autopore 9200].

(3) Diffuse reflectance (%) In accordance with the measuring method B of JIS-K7105, a spectrophotometer (manufactured by Hitachi, Ltd., model: U-3400) having a wavelength of 300 to 800 nm is used. The reflectance for each wavelength is measured, and the total reflectance of light having a wavelength of 550 nm is used as a representative value.
In addition, it shows with the relative value when the reflectance when aluminum oxide is used as a standard reflection plate is set to 100.

(4) Method for measuring total light transmittance (%) Humidity meter (manufactured by Nippon Denshoku Industries Co., Ltd., model: NDH-300)
It measures using A).

(5) UV irradiation test UV irradiation tester (manufactured by Toyo Seiki Seisakusho, Ltd., model name:
ATLAS-UVCON, type: ASTM-G53, ultraviolet light emitting lamp: Q-PANEL, type: UVA3
51, dominant wavelength: 351 nm), and at 80 ° C., ultraviolet rays of 400 MJ (megajoule) per 1 m ² of the surface of the obtained film for plant cultivation on the non-porous film side are irradiated.

(6) Ratio of Tensile Strength after UV Irradiation to Tensile Strength Before UV Irradiation Regarding the samples with and without the UV irradiation test described in the item (5), the measurement method prescribed in JIS-Z-1702 was adopted. In accordance with the tensile tester [manufactured by Orientec Co., Ltd., model:
U-1330] to measure the tensile strength (kgf),
The ratio of both (after ultraviolet irradiation / before ultraviolet irradiation) is calculated.
The tensile rupture strength (kgf) of the porous film in the machine direction (longitudinal direction) and the direction perpendicular thereto (transverse direction) is read from the recording chart.

Examples 1 to 5 and Comparative Examples 1 to 3 Linear low density polyethylene (manufactured by Mitsui Petrochemical Industry Co., Ltd.,
Product name: Ultzex 2021L, melt index (hereinafter referred to as MI) 2g / 10min, below, LL
(DPE) 100 parts by weight, the average particle size is 0.1
μm calcium carbonate (produced by Maruo Calcium Co., Ltd., trade name: MKS-G), calcium carbonate having an average particle size of 1 μm (produced by Showa Calfine Co., Ltd., trade name: SST-4)
0), or calcium carbonate having an average particle size of 7 μm (manufactured by Maruo Calcium Co., Ltd., trade name: R heavy carbon) and an ultraviolet absorber (made by ADEKA ARGUS Co., Ltd., trade name: MARK-
LA-36) in parts by weight shown in [Table 1] or [Table 2],
Further, 3 parts by weight of castor oil was mixed with a tumbler mixer, and then uniformly kneaded, melted, extruded and cut using a twin-screw extruder to form pellets. The pellets were kneaded and melt extruded at 230 ° C. using a single screw type extruder equipped with a T die to produce an unstretched film. The obtained unstretched film was uniaxially stretched at a stretching ratio shown in [Table 1] or [Table 2] between a preheating roll heated to 70 ° C. and a stretching roll to give a thickness of 20: 1.
A porous film of 00 or 200 μm was obtained.

On the other hand, LLDPE (Nippon Unicar Co., Ltd.)
Made, product name: NUCG5516, MI: 0.5g / 10
min) 100 parts by weight and an ultraviolet absorber (trade name: MARK-LA-36 manufactured by Adeka Argus Co., Ltd.) in a tumbler mixer after mixing the parts by weight shown in [Table 1] or [Table 2]. Using a screw type extruder, the mixture was uniformly kneaded, melted, extruded, and cut into pellets. The pellets were kneaded at 230 ° C. using a single screw type extruder equipped with a circular die, melt extruded, and molded by an inflation molding machine to obtain a non-porous film of 10, 100 or 200 μm. The above non-porous film is adhered to one surface of the above porous film using a commercially available adhesive and laminated to have a width of 620 mm and a length of 100 m.
A film for plant cultivation was obtained. The properties of the obtained porous film, non-porous film and plant cultivation film were measured by the above-mentioned methods. The obtained results are shown in [Table 1] or [Table 2].

Examples 6 to 7 LLDPE (manufactured by Mitsui Petrochemical Co., Ltd., trade name: Ultzex 2021L, MI: 2 g / 10 min) 10
Barium sulfate (manufactured by Barite Industry Co., Ltd., trade name: HD) and an ultraviolet absorber (manufactured by ADEKA ARGUS CORPORATION, trade name: MARK-LA-) having an average particle diameter of 1 μm per 0 part by weight.
An unstretched film was produced in the same manner as in Example 1 except that 36 parts by weight shown in [Table 2] and 3 parts by weight of castor oil were used. A thickness of 1 was obtained in the same manner as in Example 1 except that the stretching ratio of the obtained unstretched film was changed to the value shown in [Table 2].
A 00 μm stretched film was produced.

On the other hand, LLDPE (Nippon Unicar Co., Ltd.)
Made, product name: NUCG5516, MI: 0.5g / 10
min) 100 parts by weight and an ultraviolet absorber (manufactured by ADEKA ARGUS CORPORATION, trade name: MARK-LA-36) 0.3 parts by weight except that the same procedure as in Example 1 was performed to obtain a thickness of 10 μm.
A non-porous film of The non-porous film was adhered to one surface of the porous film using a commercially available adhesive and laminated to obtain a film for plant cultivation having a width of 620 mm and a length of 100 m. The properties of the obtained porous film, non-porous film and plant cultivation film were measured by the above-mentioned methods. The results obtained are shown in [Table 2].

Comparative Example 4 LLDPE (manufactured by Mitsui Petrochemical Industry Co., Ltd., trade name: Ultzex 2021L, MI: 2 g / 10 min) 10
Calcium carbonate with an average particle size of 1 μm relative to 0 parts by weight (Showa Calfine Co., Ltd., trade name: SST-40)
In the same manner as in Example 1 except that 80 parts by weight, 0.3 part by weight of an ultraviolet absorber (manufactured by ADEKA ARGUS CORPORATION, trade name: MARK-LA-36), and 3 parts by weight of castor oil were used. An unstretched film was produced. The obtained unstretched film was stretched in the same manner as in Example 1 to have a thickness of 100 μm.
m stretched film was produced. A film for plant cultivation was prepared without laminating a non-porous film on this. The porosity, diffuse reflectance, average pore diameter, ultraviolet irradiation test and tensile breaking strength were measured by the above methods. However, in the ultraviolet irradiation test, the stretched film is directly irradiated, and the tensile breaking strength is a value for the stretched film single layer. The results obtained are shown in [Table 2].

Comparative Example 5 A porous film and a non-porous film produced in the same manner as in Example 2 were used. However, in the non-porous film, a hole having a diameter of 3 mm was formed by using a punching machine so that the aperture ratio of the entire film was 30% to obtain an apertured film.
Thereafter, the porous film and the apertured film were laminated in the same manner as in Example 1 to obtain a plant cultivation film. The ultraviolet irradiation test was evaluated in the same manner as in Example 1 except that the surface of the plant cultivation film on the side of the aperture film was irradiated. The results obtained are shown in [Table 2].

Fruit Cultivation Test The film for cultivating plants obtained in Examples 1 and 2 and Comparative Examples 1 and 4 to 5 was laid on the surface of a field where apple trees were planted to carry out an apple cultivation test. . The non-porous film was placed on the front side when laying the film for plant cultivation. The main test conditions were as follows. Test place: Hanamaki City, Iwate Prefecture Cultivated fruits: Apples (variety: Fuji, number of fruit trees; 3 / condition (film) Covering area: 7 m ² / book Covering period: Approximately 2 months from the beginning of October to the end of November

(1) Evaluation of degree of coloring Harvested apples were randomly selected for each test (film) to 50%.
Individually selected, the degree of surface coloring was observed with the naked eye, and the degree of surface coloring was evaluated. For the evaluation of the degree of coloring, a portion not colored red was cut out from the surface of the apple and shown as an approximate ratio to the total surface area. The evaluation criteria were as follows.
◯: The whole apple surface was colored in red almost uniformly and no uneven coloring was observed. Δ: Uneven coloring was observed on the surface of the apple, and the area of the portion not colored red was about 20%.
What is below. X: Uneven coloring was observed on the surface of the apple, and the area of the portion not colored red exceeded 20%. The evaluation results of the degree of coloring are shown in [Table 1] or [Table 2].

(2) Breakage of film After the apples were harvested, it was observed during the cultivation test or during the harvesting work whether or not the worker walked on the plant-cultivating film due to impact or the like. The evaluation criteria for tearing were as follows. ◯: No breakage. △: 10 cm
There are 1 to 2 breaks. Poor: There are 3 or more tears of about 10 cm. The obtained results are shown in [Table 1] or [Table 2].

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

The film for cultivating plants of the present invention has a porous film as the light reflection layer, and thus, by using this, by covering the soil surface on which fruit trees such as fruits and vegetables are planted, Sun rays are evenly diffused and reflected on the entire surface of fruits and vegetables. Thus, a very useful effect can be obtained for promoting coloring of the epidermis of fruits, fruits and vegetables and preventing uneven coloring. Further, the film for plant cultivation of the present invention contains an ultraviolet absorber, further, because the non-porous film is laminated, not only has excellent mechanical strength, but also in weather resistance to exposure to ultraviolet rays and the like. It is an excellent film that can withstand long-term use. It is extremely useful as an agricultural film for cultivating plants such as fruits and vegetables.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B32B 27/32 103 C08J 9/00 CES A // B29L 9:00 C08L 23:02 (72) Invention Ikuo Akai 2-1-1, Tango-dori, Minami-ku, Aichi-ken, Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Toshiro Tatsuno 2--1, Tango-dori, Minami-ku, Nagoya, Aichi Mitsui Toatsu Chemical (72) ) Inventor Ken Ito 2-1, Tango-dori, Minami-ku, Nagoya-shi, Aichi Prefecture Mitsui Toatsu Chemical Co., Ltd.

Claims (14)

[Claims] 1. A film for plant cultivation in which a non-porous film is laminated on at least one surface of a porous film, wherein the porous film has 100 parts by weight of a polyolefin resin and an average particle diameter of 0.1 to 7 μm. Fine powder inorganic filler 1
100 to 300 parts by weight and 0.1 to 0.5 parts by weight of an ultraviolet absorber, and stretched at least uniaxially by a factor of 2 to 8 with a porosity of 40 to 70% and a diffuse reflectance of 9 at a wavelength of 550 nm of 9.
5% or more of a porous film, wherein the non-porous film contains 100 parts by weight of a polyolefin resin and 0.1 to 0.5 parts by weight of an ultraviolet absorber, and has a total light transmittance of 80% or more. A film for plant cultivation characterized by being present. 2. The average pore size of the porous film is 0.5 to 7
The film for plant cultivation according to claim 1, wherein the film has a thickness of μm. 3. The thickness of the porous film is 20 to 200 μm.
The film for plant cultivation according to claim 1, wherein the film is m. 4. The polyolefin resin is ethylene-α-
It is an olefin copolymer, The film for plant cultivation of Claim 1 characterized by the above-mentioned. 5. The plant cultivation film according to claim 1, wherein the inorganic filler is a filler selected from barium sulfate and calcium carbonate. 6. The nonporous film has a thickness of 10 to 200 μm.
The film for plant cultivation according to claim 1, wherein the film is m. 7. The tensile rupture strength after irradiating the surface of the non-porous film side of the film for plant cultivation with ultraviolet rays of 400 MJ / m ² at 80 ° C. is 0.995 or more with respect to the tensile rupture strength before the irradiation with ultraviolet rays. The film for plant cultivation according to claim 1, wherein 8. A method for cultivating a plant, which comprises coating a soil surface with a laminated film having a non-porous film laminated on at least one surface of a porous film, wherein the porous film comprises 100 parts by weight of a polyolefin resin. , 100 to 300 parts by weight of a fine powder inorganic filler having an average particle diameter of 0.1 to 7 μm and 0.1 to 0.5 parts by weight of an ultraviolet absorber, and stretched 2 to 8 times in at least one axial direction to obtain a porosity. Is 40-70
%, A diffuse reflectance at a wavelength of 550 nm of 95% or more, the non-porous film contains 100 parts by weight of a polyolefin resin and 0.1 to 0.5 parts by weight of an ultraviolet absorber, and transmits all rays. A method for cultivating plants, which is a resin film having a rate of 80% or more, and covers the soil surface with the non-porous film surface of the laminated film as the front side. 9. The average pore size of the porous film is 0.5 to 7
The method for cultivating a plant according to claim 8, wherein the method is μm. 10. The porous film has a thickness of 20 to 200.
The method for cultivating a plant according to claim 8, wherein the method is μm. 11. The polyolefin resin is ethylene-α.
9. An olefin copolymer.
The method for cultivating the plant described. 12. The method for cultivating a plant according to claim 8, wherein the inorganic filler is a filler selected from barium sulfate and calcium carbonate. 13. The nonporous film has a thickness of 10 to 200.
The method for cultivating a plant according to claim 8, wherein the method is μm. 14. The tensile rupture strength after irradiation of 400 MJ / m ² of ultraviolet light at 80 ° C. on the surface of the non-porous film side of the film for plant cultivation is 0.995 or more relative to the tensile rupture strength before irradiation of the ultraviolet light. 9. The method for cultivating a plant according to claim 8, wherein