JP2003304757A - Mulching film for agriculture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a mulching film suitable for cultivation of fruit vegetables. <P>SOLUTION: The synthetic resin laminated mulching film comprises a blue or red layer/a white layer/a black layer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention prevents the rise of soil temperature,
The present invention relates to a special mulching film which is characterized by suppressing overgrowth of ridge weeds and is particularly useful for fruit and vegetable cultivation.

[0002]

2. Description of the Related Art Conventionally, various agricultural mulching films have been developed, sold and used. Mulching film is a film that covers the surface of ridges such as ridges for the purpose of protecting the roots of agricultural products, controlling and controlling soil temperature, preventing evaporation of soil moisture, running off soil fertilizer, and suppressing overgrowth of weeds.

Among them, silver multi-films, silver-black multi-films, black-and-white multi-films, etc., which suppress the rise in soil temperature and have the effect of preventing weed overgrowth, are used in many cases, but the effect is particularly high. Since black and white multi-film is often used. However, in the case of this black-and-white multi-film, although it has a high ground temperature suppressing effect and the like because it has extremely good light ray reflection characteristics, on the other hand, the problem of leaf burning of plants often occurs. In order to solve this problem, a film having a mild light reflectance such as silver or silver black may be used, but in this case, the light reflectance of the region useful for fruits and vegetables will also be reduced. It is by no means the preferred method.

[0004]

[Problems to be Solved by the Invention] The effect of controlling the light transmittance is imparted with the effect of suppressing the soil temperature and the effect of preventing the overgrowth of weeds, and without reducing the reflection characteristics of a specific wavelength useful for the growth of fruit and vegetables The challenge is to develop a mulching film that enables prevention.

[0005]

The present inventor has conducted various studies in view of the above circumstances, and as a result, a synthetic resin laminated mulching film composed of a blue layer or a red layer / a white layer / a black layer has the above problems. The inventors have found that they can be solved and completed the present invention.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The blue layer is formed of a synthetic resin containing various blue dyes. First, various organic or inorganic blue dyes are used as the blue dye.
Examples thereof include organic phthalocyanine dyes, anthraquinone dyes, inorganic cobalt blues, and ultramarine blues.
Among them, phthalocyanine Blue 15: 1 (α type) and anthraquinone Blue 60 are preferable in terms of coloring power.

The mixing ratio to the synthetic resin is 100
It is 0.3 to 3 parts by weight, preferably 0.
It is 4 to 2 parts by weight. As a method of addition to the synthetic resin, it is convenient to use a masterbatch product which has been kneaded and blended with the base resin or the like at a high concentration in advance. If the amount added is less than 0.3 parts by weight, the light reflectance increases and the leaf burn prevention effect deteriorates. If the amount exceeds 3 parts by weight, the effect of suppressing soil temperature tends to decrease, and the effect of plant growth is saturated, which is economically undesirable. Examples of the synthetic resin used include low density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer, polypropylene, ethylene-propylene copolymer and other thermoplastic resins. Among them, linear low-density polyethylene is preferable from the viewpoint of strength development.

Various organic and inorganic dye / pigment dyes are used as the red dye constituting the red layer, and there is no particular limitation. Specific pigments include, for example, quinacridone Violet.
19, Polyazo Red 144 and the like.

The compounding ratio to the synthetic resin is 100
It is 0.3 to 3 parts by weight, preferably 0.
It is 4 to 2 parts by weight. As a method of addition to the synthetic resin, it is convenient to use a masterbatch product which has been kneaded and blended with the base resin or the like at a high concentration in advance. If the amount added is less than 0.3 parts by weight, the light reflectance increases and the leaf burn prevention effect deteriorates. If the amount exceeds 3 parts by weight, the effect of suppressing soil temperature tends to decrease, and the effect of plant growth is saturated, which is economically undesirable. Examples of the synthetic resin used include low density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer, polypropylene, ethylene-propylene copolymer and other thermoplastic resins. Among them, linear low-density polyethylene is preferable from the viewpoint of strength development.

Next, for the white pigment, titanium oxide powder has a coloring power,
Most preferable in terms of weather resistance, hiding power, and the like. Other metal oxides such as zinc oxide and lead oxide can be used. Examples of the synthetic resin used include low density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer and other thermoplastic resins.

This white layer functions to reflect sunlight, prevent an increase in ground temperature, and make the hue of the blue or red layer on the surface clearer. It should be noted that excessive reflection causes undesired leaf burning of plants. The amount of the white pigment to be blended is 15 to 40 parts by weight, preferably 20 to 35 parts by weight. If the amount is less than 15 parts by weight, the light ray reflectance is lowered and the earth temperature suppressing effect is deteriorated. On the other hand, if it exceeds 40 parts by weight, not only is the light reflectance excessive, there is a risk of leaf scorch, and the film strength is greatly reduced, which is not preferable.

Next, the black layer blocks the transmission of light rays and suppresses the overgrowth of weeds. Carbon black generally used for polyolefin films can be used as the black pigment.
Furnace carbon black can be used as the carbon black, and the particle size is preferably 40 nm or less in view of the hiding power. The amount of carbon black blended with the synthetic resin is such that the film absorbs 95% or more of the sunlight reaching the black layer, specifically in the range of 1.5 to 10% by weight, and preferably, It is about 2 to 7% by weight.

As the synthetic resin forming the layers, various synthetic resins similar to those forming the white layer are used, and among them, linear low-density polyethylene is advantageous in strength and weather resistance. The method of adding the colorant to the resin is similar to the above-mentioned blue layer, in which a masterbatch is prepared by kneading and blending the colorant into the base resin and the like at a high concentration in advance, and the masterbatch is appropriately diluted to obtain the desired concentration. The method is convenient.

The thickness of the film is 15 to 30 .mu.
m, and the range of 5 to 15 μm for each layer is suitable in terms of mulching suitability, characteristic control of light reflectance, and economical efficiency. The agricultural mulch film according to the present invention emits blue or red reflected light, and this light has various effects on the growth of plants, particularly fruit and vegetables. For example, in the case of a film having a blue layer on the surface, it controls the reflection of sunlight, has an absorption maximum of chlorophyll, and reflects light of 400 to 510 nm that contributes to the growth of plants to help the growth of plants. Suppressing the light reflection of the leaves, together with the effects of preventing leaf scorch, controlling the rise in soil temperature by the white and black layers, and suppressing the overgrowth of weeds, the effect of promoting the harvest of higher quality fruit and vegetables. It plays.

When the film has a red surface, it has maximum absorption of chlorophyll and maximum activity of photosynthesis, reflects light of wavelengths of 610 to 700 nm that contributes to plant growth, and suppresses reflection of other light. Thus, the prevention of leaf burn or the surface of the film, like the blue layer, controls the increase in soil temperature of the other white and black layers, and helps the growth of cultivated plants in combination with the effect of suppressing the overgrowth of weeds, It has the effect of promoting the harvesting of high-quality fruit and vegetables, as well as a film with a blue surface, and raising high-profit fruits.

The mulching film of the present invention is a film which is expected to have a greater effect by finely adjusting the target plant, time of use, control of reflected or transmitted light, and the like. Antioxidants, ultraviolet absorbers, and
Slip agent, heat stabilizer, other nucleating agent, insecticide, acaricide,
Fungicides, herbicides, fertilizers and the like can be added.

The laminated mulching film of the present invention is blue,
Synthetic resins in which red, white, and black dyes and other compounding agents such as light stabilizers and lubricants are appropriately mixed can be laminated to form a film by using an air-cooled multilayer inflation film molding method or a T-die multilayer film molding method. Next, the role, effect, and mode of each layer when the mulching film of the present invention is actually spread and installed will be described in detail.

The mulching film of the present invention is installed so that the blue layer or the red layer is on the sunlight irradiation side and the black layer is on the ground surface side. The white layer shows the effect of suppressing the soil temperature by the reflection of sunlight. The black layer plays the role of absorbing sunlight that passes through the white layer, and exhibits the effect of suppressing the soil temperature and the effect of growing weeds. By stacking both layers, a high effect of suppressing the rise in soil temperature is exhibited. On the other hand, the blue layer or the red layer is a layer that softens the reflected light of the white layer and selectively irradiates a required amount of light in a wavelength range that does not cause troubles of fruit vegetable growth and leaf burning.

Light rays in the vicinity of 550 nm adversely affect leaf scorch. On the other hand, the light of 400 to 510 nm has the maximum absorption of chlorophyll, and the effect of promoting the growth of plants is 610 to 700.
Since nm has maximum absorption of chlorophyll and maximum activity of photosynthesis, it has an effect of contributing to plant growth. Therefore, it is preferable that the mulching film of the present invention has a transmittance of 5% or less in the visible region (420 to 700 nm) in order to suppress an increase in soil temperature. It is particularly preferably 3% or less.

With respect to the reflected light, the reflectance of light of 550 nm is preferably 55% or less, more preferably 50% or less. Blue layer /
In the case of a film composed of a white layer / black layer, examples of target fruit and vegetables include nursery seedlings, eggplants, lettuce, and the like, and for the growth thereof, irradiation with light of 400 to 510 nm is preferable. Therefore, it is preferable that the reflectance at 470 nm is 55% or more, preferably 60% or more. In the case of a film consisting of red layer / white layer / black layer, the target fruit vegetables include strawberries, tomatoes, cucumbers, watermelons, etc.
Irradiation with light of 610 to 700 nm is preferable. Therefore 65
The light reflectance at 0 nm is preferably 50% or more, and particularly preferably 54% or more.

The dye amount and layer thickness of each layer are appropriately adjusted in consideration of the above matters. For example, when considering the white layer as a reference, when the white pigment is relatively small, the reflectance is low but the transmittance is large. Therefore, the pigment amount of the black layer is increased or the thickness of the black layer is increased. Adjustment is preferred. On the other hand, when the amount of the white pigment is large, the reflectance becomes large, so that the adjustment of increasing the amount of the blue or red pigment or increasing the thickness brings preferable results. More specifically, when the titanium oxide content is about 15 to 30 parts by weight per 100 parts by weight of the combined resin, the red or blue dye content is 0.3 to 1.5 parts by weight, and the thickness is 4 to 10 parts.
μm, black pigment content 2.0 to 5.0 parts by weight, thickness 5-1
5 μm, when the titanium oxide content is 30 to 45 parts by weight, the red or blue dye content is 0.5 to 2.5 parts, and the thickness is 5 to 15
μm, black pigment content 1.5 to 3.5 parts, thickness 4 to 10 μm
m is the preferred embodiment.

[0022]

EXAMPLES The present invention will be described in more detail below with reference to examples. Example 1 Red resin composition: 100 parts by weight of a linear low-density polyethylene resin (Novatech UA421 manufactured by Nippon Polychem), 0.6 parts of quinacridone Violet 19 as a red pigment
Parts by weight were mixed and kneaded to obtain a uniform red resin composition.

White resin composition: Linear low-density polyethylene resin (Novatech UA424 manufactured by Nippon Polychem) 10
0 parts by weight, 100 parts by weight of titanium oxide 60% by weight MB (PEX6830WAL manufactured by Tokyo Ink Co., Ltd.) were mixed and kneaded.
A uniform white resin composition was obtained. Black resin composition: 100 parts by weight of a linear low-density polyethylene resin (Novatech UA421 manufactured by Nippon Polychem) and 40% by weight of carbon black MB (PEX998020B manufactured by Tokyo Ink Co., Ltd.) 7
Parts by weight were mixed and kneaded to obtain a uniform black resin composition.

Each of the resulting resin compositions was subjected to a multi-layer blown film molding machine manufactured by Mitsubishi Chemical Engineering Co., Ltd. at 200 ° C. to form a red resin composition as an outer layer, a white resin composition as an intermediate layer, and a black resin composition as an inner layer. Each was supplied and film-forming was performed, and the laminated film which consists of three layers of red / white / black and the thickness of each layer was 6 μm / 8 μm / 6 μm was manufactured.

Example 2 Blue resin composition: 100 parts by weight of a linear low-density polyethylene resin (Novatech UA421 manufactured by Nippon Polychem), and phthalocyanine Blue 15: 1 (α type) as a blue dye.
Was mixed and kneaded to obtain a uniform blue resin composition. Using the obtained blue resin composition, the white resin composition used in Example 1, and the black resin composition, film formation was carried out in the same manner as in Example 1 to form three layers of blue / white / black. A laminated film having a thickness of each layer of 6 μm / 8 μm / 6 μm was manufactured.

Comparative Example 1 100 parts by weight of a linear low-density polyethylene resin (Novatech UA421 manufactured by Nippon Polychem Co., Ltd.) was used as the outer layer and inner layer resin, and the white resin composition in Example 1 was used as the intermediate layer resin. The film was formed in the same manner as in Example 1 and was transparent /
3 layers of white / transparent, each layer has a thickness of 6μm / 8μm
A laminated film of / 6 μm was produced.

Comparative Example 2 A transparent / white / black film was formed in the same manner as in Example 1 except that the outer layer resin was 100 parts by weight of linear low-density polyethylene (Novatech UA421 manufactured by Nippon Polychem). Of 3
A laminated film having layers, each layer having a thickness of 6 μm / 8 μm / 6 μm, was produced.

Comparative Example 3 100 parts by weight of linear low-density polyethylene (Novatech UA421 manufactured by Japan Polychem) and 100 parts by weight of linear low-density polyethylene (Novatech UA424 manufactured by Japan Polychem) were used as the intermediate layer resin. Aluminum metal powder 30 wt% MB (PE-M581MK silver manufactured by Dainichiseika Co., Ltd.) was mixed and kneaded, and the kneaded resin composition was used, and the black resin composition in Example 1 was used as the inner layer resin. Film formation was carried out in the same manner as in 1. to produce a laminated film composed of three layers of transparent / silver / black, each layer having a thickness of 6 μm / 8 μm / 6 μm.

Comparative Example 4 The red resin composition, the white resin composition and the black resin composition used in Example 1 were used, and a white resin composition was used for the outer layer,
The red resin composition was supplied to the intermediate layer and the black resin composition was supplied to the inner layer, and the film formation was performed in the same manner as in Example 1, and the thickness of each layer was 6 μm / 8 μm, which was composed of three layers of white / red / black.
A laminated film of / 6 μm was produced.

(Film Performance Test) The films obtained in Examples 1 and 2 and Comparative Examples 1 to 3 were subjected to the following performance comparison tests, and the results are summarized in Table 1. (1) Spectral transmittance characteristics A spectrophotometer (MPS-2000 manufactured by Shimadzu Corporation) was used to measure the transmittance (%) of the above-prepared film at 420 to 700 nm. The average transmittance over the entire area of this spectral transmittance curve was calculated and used as the light transmittance value of the film. It can be said that the lower this value, the higher the effect of preventing weed overgrowth.

(2) The light reflectance spectrophotometer (CE-3100 manufactured by Gretag Macbeth) was used to measure the reflectance (%) of the above-prepared film at 400 to 700 nm. At this time, 470nm, 55
The reflectance at 0 nm and 650 nm was read and used as the reflectance value of the film. If the reflectance around 550 nm exceeds 55%, leaf burning may occur during cultivation.

[0032]

[Table 1]

[0033]

EFFECTS OF THE INVENTION The mulching film of the present invention reflects light rays having a wavelength necessary for plant growth to assist plant growth,
Suppresses and controls the rise in soil temperature, suppresses overgrowth of weeds,
Therefore, high quality cultivated fruits and vegetables can be efficiently cultivated.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Naoetsu Kimura             Marui, 1114, Tsutsuto, Taniwahara Village, Tsukuba-gun, Ibaraki Prefecture             Processing Co., Ltd. F-term (reference) 2B024 DA04 DA05 DB01

Claims (6)

[Claims] 1. A synthetic resin laminated mulching film comprising a red layer or a blue layer / a white layer / a black layer. 2. A synthetic resin laminated mulching film comprising a blue layer / white layer / black layer having a light reflectance of 55% or less at a wavelength of 550 nm on the blue layer side and a light reflectance of 60% or more at a wavelength of 470 nm. . 3. A synthetic resin laminated mulching film comprising a red layer / white layer / black layer having a light reflectance of 55% or less at a wavelength of 550 nm on the red layer side and a light reflectance of 50% or more at a wavelength of 650 nm. . 4. The white layer is formed of a synthetic resin containing an inorganic pigment selected from the group consisting of titanium oxide, zinc oxide and lead oxide, and the black layer is formed of a synthetic resin containing carbon black. Item 4. The mulching film according to any one of Items 1 to 3. 5. The light transmittance of 420 to 700 nm is 5%.
The mulching film according to any one of claims 1 to 4, which is as follows. 6. The mulching film according to claim 1, wherein the synthetic resin used is linear low density polyethylene.