JPS63152930A - Agricultural harmful insect control film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an agricultural film that has a control effect against pests harmful to crops during the cultivation of crops.

<Prior art> Conventionally, when growing crops such as vegetables, flowers, and fruit trees,
Transparent or translucent polyethylene films, ethylene-vinyl acetate copolymer films, and soft vinyl chloride resin films have been used to cover greenhouses and tunnels, or to cover the ground for crop cultivation. The purpose of covering greenhouses and tunnels is to promote the growth of crops while maintaining a high temperature inside greenhouses and tunnels during low-temperature periods, and to save energy for heating inside greenhouses during extremely cold periods.

° In recent years, with the spread and development of cover cultivation as mentioned above,
Damage caused by caterpillars has become a serious problem, with a growing number of pests flying into cultivated crops, becoming parasitic, and causing extensive damage.

Methods for controlling these pests have been proposed, such as using pesticides such as repellents and insecticides, and trapping them with traps using pheromones and colored tape, which have the effect of attracting pests. Some parts have been put into practical use.

However, these methods also have problems, such as the resistance that develops in pests over time and the development of more insecticidal pesticides. It has inherent problems such as increased toxicity and increased accumulation in the soil, which can lead to secondary pollution such as environmental pollution.

<Problems to be solved by the invention> As a pest control method that does not cause the above-mentioned problems, it is possible to cover cultivated crops or the ground with a film that is highly reflective of sunlight and is made by vapor-depositing a metal such as aluminum. A method for controlling flying pests and a method for controlling pests in covered houses and tunnels using film fogging ζ that cuts near ultraviolet rays have been proposed and put into practical use.

However, regarding these methods, the former is not suitable for covering greenhouses or tunnels because the product cost is high, and although the light reflectance is high, the light transmittance is low. However, the problem is that the soil temperature does not rise easily, making it impractical for crop cultivation except for special uses that take advantage of this characteristic.Although the latter has excellent pest control effects in covered greenhouses and tunnels, There are problems such as poor flower coloration, which limits the crops that can be used. Furthermore, the use of mulch has no pest control effect at all.

In view of these circumstances, the present inventors first raised the soil temperature of the crop cultivation ground and controlled pests that fly to and parasitize the crops, thereby improving the quality of the cultivated crops. For protection and growth promotion, it has a reflection peak at a wavelength of less than 0.4 μm, and the ratio R of its ultraviolet reflectance RA to the visible light reflectance RB at a wavelength of 0.5 μm.
It has been found that a film having a reflection spectrum with A/RB of 1.4 or more is effective in pest control.

Furthermore, as a result of intensive studies aimed at developing a better pest control film, the present inventors found that it has a reflection peak at a wavelength of less than 0.4 μm, and its ultraviolet reflectance RA and wavelength of 0.6 μm
The ratio RA/RB of m to the visible light reflectance RB is 1°6 or more, and the visible light reflectance RC at a wavelength of 0.6 μm or more
The present inventors have discovered that a film having a reflection spectrum in which the ratio RC/RB of RB and RB is 1.5 or more is more effective in controlling pests, and has completed the present invention.

The present invention relates to a pest control film formed from a thermoplastic resin composition containing at least one inorganic compound that reflects ultraviolet rays and a colorant.

The present invention will be explained in detail below.

The thermoplastic resin used in the present invention is not particularly limited, but examples include low density polyethylene, high density polyethylene, ethylene-butene 1 copolymer, ethylene-4-methyl-pentene-1 copolymer, ethylene- Vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-vinyl acetate-methyl methacrylate copolymer, ethylene-
Ethylene homopolymers and copolymers such as ethyl acrylate copolymers, polypropylene, vinyl chloride resins, etc. can be used, and these can be used alone or in combination.

The inorganic compounds used in the present invention reflect ultraviolet rays with a wavelength of less than 0.4 μm, and include, for example, potassium titanate, calcium titanate, magnesium titanate, barium titanate, lithium titanate, and silicate titanate. titanium compounds such as aluminum, zirconium silicate,
Examples include zirconium compounds such as zirconium oxide.

Further, these inorganic compounds may be in the form of powder or whiskers, but whiskers are more preferable in view of the strength and light reflection characteristics of the film.

The coloring agent may be any inorganic compound or organic compound as long as it is a material that absorbs little ultraviolet light with a wavelength of 0.35 μm to 0.4 μm and absorbs visible light with a wavelength of 0.5 μm.

For example, the common names are Lake Red C1 Pyrazolone Red B, Brilliant First Scarlet,
Examples include condensed azo scarlet, Barium Red 2B Watch Yan Red Y1 Perylene Red 178, but those with high bleed-out resistance and weather resistance are more preferred.

The film of the present invention can be manufactured by the following steps.

A thermoplastic resin composition containing an inorganic compound or a coloring agent can be obtained by mixing and kneading the powder while melting the resin using a conventional Banbury mixer, two-roll mixer, or extrusion mixer. The obtained resin composition was processed by ordinary inflation silane film processing, 1゛ die film processing,
The film can be formed using a film processing machine such as a calendarer.

In addition, in order to obtain a laminated film in which a thermoplastic resin layer containing a transparent or coloring agent is provided on the inner surface, inner or outer surface of a resin layer containing an inorganic compound, etc., a two-layer die is used.
A thermoplastic resin composition containing an inorganic compound and a thermoplastic resin composition containing a transparent or coloring agent are extruded separately from one extruder to form a 2NJ film, or two extruders equipped with an 8-layer die are used to form a 2NJ film. Using an extruder, an 8-layer film can be formed by forming 8I layers of a resin layer containing an inorganic compound as an intermediate layer and a thermoplastic resin layer that is transparent or contains a coloring agent on the inner and outer surfaces.

In the case of these laminated films, the resins of the inorganic compound-containing film layer and the transparent or colored film layer may be the same or different.

In addition, in order to lower the soil temperature and prevent the growth of weeds, it is preferable to laminate a black film layer containing carbon black, which completely absorbs the transmission of light. It can be processed by machine.

The content of inorganic compounds is 5-80%, and the colorant is 0.5%.
~5% by weight is preferred, but has a reflection peak at a wavelength of less than 0.4 μm, and exhibits a ratio RA/RB of ultraviolet reflectance RA to visible light reflectance RB at a wavelength of 0.5 μm of 1.5 or more, Visible light reflectance RC and R for wavelengths of 0.6 pm or more
It is sufficient if the ratio RC/RB with B is 1.5 or more.

The appropriate thickness of the inorganic compound-containing film is 20 to 100 μm from the viewpoint of the balance between performance and economy, as well as from the handling work surface.
In the case of a layered film, it is preferable that the thickness of the inorganic compound-containing film layer is 5 to 50 μm and the total thickness of the laminated film of one transparent film layer is 5 to 100 μm.

<Example> Example 1 Low density polyethylene (density 0.928, Ml=1.5F
/10 minutes), 20 parts by weight of potassium titanate whiskers, and 0.6 parts by weight of the colorant condensed unscarlet were mixed in a 51 Banbury mixer at a resin temperature of 150 to 160.
After mixing for 5 minutes at "C", granulated pellets were produced using an extruder (referred to as A mixed resin). Next, the G was put into an inflatable film processing machine and heated under the conditions of a melting zone of 220 °C and a die temperature of 200 °C. A single layer film with a thickness of 80 μm was molded.

The performance and test results of the obtained film are shown in FIG. 1 and Tables 1 and 2.

Example 2 A two-layer inflatable blowing machine equipped with two extruders and two-layer dies was used to remove the colorant from the A mixed resin (referred to as the B mixed resin) and the titanic acid mixed A resin. The mixture with potassium whiskers removed (referred to as C mixed resin) was put into a separate extruder, and under the same conditions as Example 1, two layers were laminated while melting and adhering the B mixed resin and C mixed resin in a two-layer die. A film was formed.

The obtained film was a two-layer film with a thickness composition ratio of B mixed resin layer/C mixed resin layer of 1/l and a total thickness of 40 μm.

The film performance test was conducted by mulching the C mixed resin layer on the outside, and the results are shown in Figure 1 and Tables 1 to 1.
Shown in 2.

Example 8 100 parts by weight of the same low density polyethylene as described above and 5 parts by weight of carbon black were kneaded and granulated in the same manner as in Example 1 to produce pellets (referred to as D mixed resin). The A mixed resin and the D mixed resin were inflated in two layers in the same manner as in Example 2.
Depending on the processing method, two-layer films were obtained.

The film performance test was conducted by mulching Gζ so that the A mixed resin layer was on the outside, and the results are shown in Figure 1 and Table 1.
It is shown in 2.

Example 4 A product with a thickness of 20 μm was prepared in the same manner as in Example 1, except that the titanium hydroxide whiskers were replaced with zirconium silicate and the colorant was replaced with Pyrazolone Red B.
obtained the film. The performance test results of the film are shown in FIG. 2 and Tables 1 and 2.

Example 5 A product with a thickness of 20 μm was prepared in the same manner as in Example 1, except that the potassium titanate whisker was replaced with aluminum titanate silicate containing 2 parts by weight of titanium oxide, and the colorant was replaced with Lake Red C. obtained the film.

The performance test results of the film are shown in FIG. 2 and Tables 1 and 2.

Comparative Example 1 A single layer film was formed from the C mixed resin of Example 2 using an inflatable temporary processing machine under the same conditions as Example 1. The obtained film was a single layer film with a thickness of 80 μm. The performance and test results of this film are shown in Figure 3 and Tables 1-2.

Comparative Example 2 Commercially available silver film (manufactured by Miyoshi Co., Ltd., thickness 80 μm
) was used to test film performance. The results are shown in Figure 8.
and shown in Tables 1 and 2.

Comparative Example 8 A two-layer film was obtained from mixed resin B and mixed resin D using the two-layer inflation binding method in the same manner as in Example 2. The film performance test was conducted by mulching the B mixed resin layer on the outside, and the results are shown in FIG. 8 and Tables 1 and 2.

Performance tests of the films shown in Examples and Comparative Examples were conducted in the following manner.

(1) Ultraviolet and visible light reflection spectra The ultraviolet and visible light reflection spectra of the film were measured using a Hitachi self-recording spectrophotometer model 880.

(2) Value of RA/RB1RC/RB The value of RA/RB in Comparative Examples 1 to 8 is the ratio of the reflectance at a wavelength of 0.88 μm and the reflectance at a wavelength of 015 μm.
The value of RB is the reflectance at 0.62 μm and the wavelength of 0.5
It was expressed as the ratio of reflectance in μm.

(3) Pest control effect Cabbage seedlings were mulched with a film and the number of aphids (wingless insects) was investigated in a greenhouse for 10 days.

<Effects of the invention> The film obtained as described above can be used for covering greenhouses, tunnels, and mulching the ground for crop cultivation, and it protects against ultraviolet rays with a wavelength of less than 0.4 μm and wavelengths of 0, which pests dislike.
．． By increasing the reflection rate of visible light of 6 μm or more and lowering the reflection of attracted light in the wavelength range of 0.5 μm, it exerts a control effect on crop pests such as southern thrips and aphids. In addition, by reflecting visible light of 0.6 μm or more on the leaf surface of cultivated plants, the photosynthetic reaction of cultivated plants is activated.

[Brief explanation of the drawing]

FIG. 11 FIG. 2 and FIG. 8 are reflection spectra of films of examples of the present invention and comparative examples. Table 1. RA/RB, Re/RB value table 2 of various films
Pest control property diagram 1. Reflection spectra of various films 2. Reflection spectrum wavelength (nm) of various films

Claims (7)

[Claims] (1) Has a reflection peak at a wavelength of less than 0.4 μm, its ultraviolet reflectance RA and visible light reflectance RB at a wavelength of 0.5 μm
The ratio RA/RB is 1.5 or more, and the wavelength is 0.6 μm.
The ratio RC/RB of the above visible light reflectance RC and RB is 1
．． An agricultural pest control film characterized by having a reflection spectrum of 5 or more. (2) The film according to claim 1, which is formed from a thermoplastic resin composition containing an inorganic compound and a colorant. (3) The film according to claim 2, wherein the inorganic compound is at least one titanate compound. (4) The film according to claim 2, wherein the inorganic compound is at least one silicate compound. (5) The film according to claim 1, wherein a transparent thermoplastic resin layer is laminated on the inner surface, inner surface, or outer surface of a thermoplastic resin layer containing at least one inorganic compound and a colorant. (6) The film according to claim 1, wherein a thermoplastic resin layer containing a colorant is laminated on the inner surface, inner surface, or outer surface of a thermoplastic resin layer containing at least one inorganic compound. (7) The film according to claim 1, wherein a black thermoplastic resin layer containing carbon black or the like is laminated on a thermoplastic resin layer containing at least one inorganic compound and a colorant.