Agricultural insect-repellent film

Abstract

Agricultural insect-repellent film that helps control agricultural pests. [Solution] An agricultural insect-repellent film in which a photocatalytic layer is coated on the surface of a base film.

Description

Technical Field

[0001] The present disclosure relates to an insect-proof film for agricultural use.

Background Art

[0002] Non-Patent Document 1 discloses the basic principle of the environmental purification effect by titanium oxide photocatalyst and specific examples of its practical development. That is, as applications of titanium oxide photocatalyst to environmental purification, decomposition and removal of nitrogen oxides (NO x ) in the atmosphere, detoxification and purification of polluted water, and antifouling, deodorizing, and anti-fogging functions are mentioned.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to provide an insect-proof film for agricultural use that contributes to the control of agricultural pests as an application of photocatalyst to the agricultural field.

Means for Solving the Problems

[0005] The insect-proof film for agricultural use according to an embodiment of the present disclosure is obtained by coating a photocatalyst layer on the surface of a base film. It is desirable to interpose a silica layer between the base film and the photocatalyst layer. Further, it is desirable that the photocatalyst layer is formed of a tungsten trioxide catalyst or a titanium dioxide catalyst. Furthermore, it is desirable that the base film is formed of biodegradable plastic.

Effects of the Invention

[0006] As the embodiments of this disclosure are configured as described above, an agricultural insect-repellent film that contributes to the control of agricultural pests is provided as an application of photocatalysis to the agricultural field. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic cross-section of the agricultural insect-repellent film according to this embodiment is shown. [Figure 2] This photograph shows the condition immediately after the start of an experiment to verify the insect-repellent effect of photocatalysis. [Figure 3] This is a photograph showing the state two hours after the state shown in Figure 2. [Figure 4] This photograph shows the experimental results when the application of the photocatalyst is changed compared to the state shown in Figure 2. [Figure 5] This photograph shows the conditions immediately before the start of an experiment to verify the pest-repellent effect of agricultural insect-proof film. [Figure 6] This is a photograph showing the state two hours after the start of the experiment, compared to the state shown in Figure 5. [Modes for carrying out the invention]

[0008] Embodiments of this disclosure will be described below with reference to the drawings. Reference numerals that appear in common in each drawing refer to the same components or members, even if they are not specifically mentioned in the description of each drawing.

[0009] Figure 1 is a schematic cross-sectional view of the agricultural insect-repellent film 10 according to the embodiment. Note that the thickness of each layer shown in this figure does not necessarily reflect the thickness of each layer in the actual product.

[0010] In the agricultural insect repellent film 10 of this embodiment, a photocatalytic layer 40 is coated on the surface of the base film 20. A silica layer 30 is interposed between the base film 20 and the photocatalytic layer 40.

[0011] The material of the base film 20 is not particularly limited as long as it is a synthetic resin material that has flexibility and durability, but considering the impact on the environment, it is desirable to use biodegradable plastics such as polyhydroxyalkanoate, bacterial cellulose, chitosan / cellulose / starch, cellulose acetate, esterified starch, poly-L-lactic acid, polybutylene succinate, polycaprolactone, polybutylene adivate terephthalate, modified polyethylene terephthalate, polyglycolic acid, or polyvinyl alcohol.

[0012] It is preferable to form the photocatalytic layer 40 using a titanium dioxide catalyst.

[0013] The silica layer 30 is formed by coating the surface of the base film 20 with, for example, colloidal silica, and then irradiating it with heat, light, or plasma to dereact with the OH groups on the surface of the base film 20 and immobilize it. A photocatalyst layer 40 is coated onto the surface of this silica layer 30 by spraying an aerosol of a photocatalyst (for example, a tungsten trioxide catalyst or titanium dioxide) and irradiating it again with heat, light, or plasma to immobilize the photocatalyst. This forms the agricultural insect-repellent film 10.

[0014] When seedlings of crops (for example, rice) are wrapped in this agricultural insect-repellent film 10 and planted in the soil of a rice paddy, when exposed to sunlight, O2 is produced by the photocatalytic principle described in Non-Patent Document 1. - The oxidizing ability of superoxide anion radicals repels pests, thus protecting crops from pests. In addition, the insect-repellent effect of the agricultural insect-repellent film 10 can be expected in environments where water and oxygen are present, such as in water or soil, and where light such as sunlight is irradiated. [Examples]

[0015] (1) Verification of the pest repellent effect of photocatalysts Verification of the pest repellent effect of tungsten trioxide as a photocatalyst was carried out. Specifically, as shown in Fig. 2, the bottom surface of a glass test water tank 50 was divided into two parts. One test section E was coated with a photocatalyst, while the other control section C was not coated with a photocatalyst. That is, colloidal silica was applied to the entire bottom surface of the test water tank 50, dried, and then irradiated with heat, light or plasma for immobilization. Then, only in the test section E, tungsten trioxide aerosol (visible light-responsive photocatalyst "Lunecat", Toshiba Materials) was sprayed, dried, and then irradiated with heat, light or plasma for immobilization. As a control experiment, a control water tank 55 (see Fig. 3) was also prepared in which the bottom surface was divided into two parts in the same manner as the test water tank 50, colloidal silica was applied to the entire surface, but neither the control section C nor the test section E was coated with a photocatalyst.

[0016] After immobilizing the photocatalyst, water was poured to a depth of about 5 mm, and then 10 jumbo thistles as test specimens 60 were placed in each control section C of the test water tank 50 and the control water tank 55, and observed under fluorescent lamp illumination for 2 hours. As a result, as shown in Fig. 3, in the control water tank 55, the test specimens 60 moved around freely without distinction between the control section C and the test section E, whereas in the test water tank 50, even after 2 hours, none of the test specimens 60 entered the test section E. From this, it was inferred that the photocatalyst has a repellent effect on jumbo thistles as agricultural pests.

[0017] In addition, when only tungsten trioxide aerosol was sprayed and dried without applying colloidal silica in the test section E, as shown in Fig. 4, the test specimens 60 also entered the test section E. This is presumably because the photocatalyst dissolved in water over time, so that the photocatalytic effect could not be fully exerted.

[0018] (2) Verification of the pest repellent effect of an insect-proof film for agriculture The agricultural insect-proof film 10 having the structure shown in FIG. 1 was formed into a tubular shape as shown in FIG. 5. This agricultural insect-proof film 10 is formed by applying colloidal silica to the surface of a biodegradable plastic base film 20 containing plant-derived cellulose and starch, drying to form a silica layer 30, and then spraying the tungsten trioxide aerosol mentioned in (1) from above, drying, and immobilizing to form a photocatalyst layer 40. The root portion of the rice seedling 90 was inserted into the tubular agricultural insect-proof film 10 as shown in FIG. 5. Then, the seedling 90 in this state was planted in the soil 80 housed in a box-shaped container 70 as shown in FIG. 5.

[0019] As shown in FIG. 6, the container 70 was divided into three sections, and the central section was set as the test section E where the seedling 90 with its root wrapped by the agricultural insect-proof film 10 of the present disclosure was planted. Also, the right side was set as the first control section C1 where the seedling 90 with its root wrapped by only the control film 11 of the base film 20 without forming the photocatalyst layer 40 was planted. Further, the left side was set as the second control section C2 where the seedling 90 not wrapped by a film was planted. In this state, ten jumbo tanisi as the test subject 60 were released into the container 70 and observed for 2 hours under fluorescent lamp illumination.

[0020] As a result, as shown in FIG. 6, although the test subject 60 approached the seedlings 90 in the first control section C1 and the second control section C2, none of the test subject 60 approached the seedlings 90 in the test section E. Therefore, it is presumed that the agricultural insect-proof film 10 of the present disclosure has a pest repellent effect, and the insect-proof effect when used at the site of agricultural work is expected.

[0021] In the above embodiment, tungsten trioxide was used as the photocatalyst, but the same insect-proof effect was observed when titanium dioxide was used.

Explanation of Reference Numerals

[0022] 10 Agricultural insect-proof film 11 Control film 20 Base film 30 Silica layer 40 Photocatalyst layer 50 test tanks 55 Control Tank 60 subjects 70 containers 80 Saturday 90 seedlings C Control group C1 Control Group 1 C2 Second Control Group E Experimental Area

Claims

1. An agricultural insect-repellent film in which a photocatalytic layer is coated on the surface of a base film.

2. The agricultural insect repellent film according to claim 1, wherein a silica layer is interposed between the base film and the photocatalytic layer.

3. The agricultural insect repellent film according to claim 1 or claim 2, wherein the photocatalytic layer is formed of a tungsten trioxide catalyst or a titanium oxide catalyst.

4. The aforementioned base film is made of biodegradable plastic, wherein the agricultural insect-repellent film is as described in claim 3.

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