JPH043175B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a UV-shielding mulching coating material having small pores with a porosity of 0.01% or more and less than 1%, and more specifically, it has at least the following: The present invention relates to an ultraviolet-shielding mulching coating material that has the ability to substantially block ultraviolet rays in the wavelength range of 340 nm or less and has small pores with a porosity of 0.01% or more and less than 1%. In order for plants to grow in a healthy manner, they must be provided with light, air, and water, as well as an appropriate temperature and appropriate amount of nutrients. In recent years, with the development of science and technology, in the field of plant cultivation technology, light quality control of the plant cultivation environment has been implemented, such as increasing carbon assimilation by supplying CO ₂ , promoting root development by supplying oxygen in the soil, and automatically supplying water. Research and practical application of this technology are making remarkable progress. Furthermore, a mulching cultivation technique using a so-called film that spreads closely to the ground surface to cover it is also known. Films used in such mulching cultivation are mainly transparent films made of polyethylene, or films colored black or green. Mulching with the film has advantages such as keeping the soil warm, retaining moisture in the soil, preventing fertilizer nutrients from being washed away, preventing soil from bouncing back, and suppressing the growth of weeds. Recently, UV-shielding mulching materials have also been used. For example, in Japanese Patent Application Laid-open No. 53-98242,
A method for cultivating root vegetables characterized by mulching and cultivating root vegetables under a covering with a mulching covering material made of a transparent film capable of substantially blocking light of wavelengths of 370 nm and below, JP-A-53-124556
The publication proposes a transparent mulching coating material made of a synthetic resin film or plate that substantially blocks the transmission of ultraviolet rays having a wavelength of at least 370 nm or less. However, it has not been known until now to use a mulching coating material that selectively blocks ultraviolet rays in a specific wavelength range and has small pores with a porosity of 0.01% or more and less than 1%. The present inventors have discovered that in the process of mulching-covered cultivation of useful crops, especially fruit and vegetable crops, at least
When an ultraviolet shielding film that substantially blocks light at wavelengths of 340 nm and below and has small pores with a porosity of 0.01% or more and less than 1% is used as a mulching coating material, it is possible to eliminate We have discovered that useful crops can be harvested earlier and in larger amounts than in the conventional case, and that the quality of the harvested useful crops is comparable to that of conventional crops, and we have completed the present invention. I've reached it. Thus, according to the invention, at least 340 nm
It substantially blocks ultraviolet rays of up to and below, and has a diameter of 1.5m/m or less in the longitudinal direction and a small porosity.
A transparent thermoplastic resin ultraviolet-shielding mulching coating material is provided, which is characterized by having small pores of 0.01% or more and less than 1%. There are various possible reasons for the effects obtained by the mulching coating material of the present invention, but one example is that it actively penetrates the atmosphere into the soil phase while blocking ultraviolet rays and minimizing the drop in soil temperature. It is presumed that this increases the nitrogen fertilizer in the soil phase, especially the nitrate nitrogen content that plants can absorb from their roots, and that the lack of oxygen in the roots is resolved. Conventional mulching films are completely isolated from the atmosphere except for the planting holes, so there is almost no penetration of the atmosphere. Under conventional mulching materials, as useful plants grow, their roots also elongate and their oxygen demand increases.
Gradually, the oxygen content in the soil will decrease. For this reason, the oxidation, decomposition, and ripening of fertilizers in the soil are prevented, and the roots of useful plants are presumed to be in a state of oxygen starvation. "Mulching" as used herein means covering the soil surface of a field where crops are growing with a film-like covering material instead of grass, and the covering material used for this purpose is a mulching covering material. It is. The mulching coating material of the present invention, as previously described, is comprised of certain "UV-screening" materials that are capable of substantially blocking light (ultraviolet radiation) at wavelengths of at least 340 nm and below. Here, "capable of substantially blocking" light with wavelengths of xnm and below xnm
This term is used not only to completely block 100% of light with wavelengths of 340nm or less, but also to allow up to 40%, preferably 20% or less of light to pass through.In the present invention, at least 340nm Use a coating material that can completely (nearly 100%) block light at wavelengths of and below, preferably 360 nm, particularly preferably 380 nm, and even more preferably substantially block light at wavelengths of 400 nm and below. . It is desirable that the transparent film does not substantially inhibit the transmission of light useful for plant growth, and can transmit light with a wavelength of at least 520 nm or more, more preferably light with a wavelength of 500 nm or more. It is desirable to use a film that is substantially transparent. Here, "capable of substantially transmitting" light of wavelengths of ynm and above means 100% transmission of light of wavelengths of ynm and above, of course.
The meaning also includes transmitting at least 60%, especially 70% or more of light of the wavelength. Therefore, the coating material that can be particularly suitably used in the present invention substantially completely blocks, preferably 95% or more, of light having a wavelength of 400 nm or less, and
Does not substantially inhibit light at wavelengths of 500 nm and above. It is preferably a coating material that can transmit 85% or more, and when a curve of the coating material's light wavelength (horizontal axis) versus light transmittance (vertical axis) is drawn, the curve is the light wavelength.
Particularly suitable is a coating material that exhibits light transmittance characteristics that rise as vertically as possible between 400 nm and 500 nm. In addition, the small holes of the present invention refer to a large number of holes drilled all over the mulching film, unlike conventional planting holes for crops or holes drilled for easy adaptation to the soil. The shape of the small hole may be any shape, but preferably circular, oval, or
Particularly preferred is a circular shape. The diameter of the small hole in the long axis direction is 1.5 m/m or less, preferably 1.0 m/m.
m or less, more preferably 0.5 m/m or less.
The positions of the small holes may be random, but it is preferable that they be uniform. In this case, holes for planting seedlings of useful plants are opened in the conventional manner. Also, the distance between the small holes may be any value, but preferably 0.1 cm to 50 cm, particularly preferably
The length is 0.5 cm to 30 cm, more preferably 1 cm to 10 cm.
The small porosity [the ratio of the total area of small pores to the total area of the mulching film (%)] is 0.01% or more and less than 1%,
Preferably 0.01 to 0.9%, particularly preferably 0.05 to 0.9%
It is 0.7%, more preferably 0.1 to 0.5%. The transparent thermoplastic resin film or plate that can be used in the present invention can be produced, for example, by blending a suitable ultraviolet absorber with a normal film-forming thermoplastic resin and molding the mixture into a film or plate. Examples of usable film-forming thermoplastic synthetic resins include polyvinyl chloride, polyvinylidene chloride, polyethylene, polypropylene, polystyrene, polyester, polyamide, polycarbonate, polymethyl methacrylate, polyacrylate, polyvinyl acetate, polyvinyl alcohol,
Examples include fluorine-containing resins, cellulose resins, ABS resins, etc., or copolymers or blends mainly composed of these polymers (preferably 50% by weight or more). For this reason, polyvinyl chloride, polyethylene, polypropylene, polyester, fluorine-containing resin, cellulose resin, and polycarbonate are preferred. In addition, an ultraviolet absorber capable of substantially blocking the transmission of light with a wavelength of at least 340 nm or less when blended with a thermoplastic resin such as the one described above is important in determining the ultraviolet absorbing ability of the ultraviolet absorber and the thermoplastic resin used. It is possible to appropriately select and use a wide variety of types in consideration of compatibility with the compound and the like. Examples of usable ultraviolet absorbers include the following.
Hydroquinone type...hydroquinone, hydroquinone disalicylate salicylic acid type...phenyl salicylate, paraoctylphenyl salicylate benzophenone type...2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4- n-
Octoxybenzophenone, 2-hydroxy-4
-methoxy-2'-carboxybenzophenone,
2,4-dihydroxybenzophenone, 2,2'-
Dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-benzoyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzo Phenon, 2, 2', 4,
4′-tetrahydroxybenzophenone, 2,2′-
Dihydroxy-4,4'-dimethoxy-5-sodium sulfone benzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-5-chlorobenzophenone benzotriazole type...2-(2'- Hydroxy-5'-methylphenyl)benzotriazole, 2
-(2'-hydroxy-5'-methylphenyl)-5
-Butoxycarbonylbenzotriazole, 2-
(2′-hydroxy-5′-methylphenyl)-5,
6-dichlorobenzotriazole, 2-(2'-hydroxy-5'-methylphenyl)-5-ethylsulfonebenzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, 2-
(2′-hydroxy-5′-amyl phenyl)benzotriazole, 2-(2′-hydroxy-3′,5′-
dimethylphenyl)benzotriazole, 2-
(2′-hydroxy-3′,5′-dimethylphenyl)—
5-methoxybenzotriazole, 2-(2'-methyl-4'-hydroxyphenyl)benzotriazole, 2-(2'-stearyloxy-3',5'-dimethylphenyl)-5-methylbenzotriazole, 2-(2′-hydroxy-5′-ethoxycarbonylphenyl)benzotriazole, 2-(2′-
Hydroxy-3'-methyl-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chloro-benzotriazole, 2-(2'- Hydroxy
5′-methoxyphenyl)benzotriazole, 2
-(2'-Hydroxy-5'-Phenylphenyl)-
5-chlorobenzotriazole, 2-(2'-hydroxy-5'-cyclohexylphenyl)benzotriazole, 2-(2'-hydroxy-4',5'-dimethylphenyl)-5-butoxycarbonylbenzotriazole, 2-(2′-hydroxy-3′,
5′-dichlorophenyl)benzotriazole, 2
-(2′-hydroxy-4′,5′-dichlorophenyl)
Benzotriazole, 2-(2'-hydroxy-
3′,5′-dimethylphenyl)-5-ethylsulfobenzotriazole, 2-(2′-hydroxy-
5'-Phenylphenyl)benzotriazole, 2
-(2′-hydroxy-4′-octoxyphenyl)
Benzotriazole, 2-(2'-hydroxy-
5'-methoxyphenyl)-5-methylbenzotriazole, 2-(2'-hydroxy-5'-methylphenyl)-5-ethoxycarbonylbenzotriazole, 2-(2'-acetoxy-5'-methylphenyl)benzotriazole , 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-
3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole. Among these ultraviolet absorbers, benzophenone-based and benzotriazole-based ones are preferred, and among the benzophenone-based ones, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,
2'-dihydroxy-4-methoxybenzophenone and 2,2',4,4'-tetrahydroxybenzophenone; in benzotriazole series, 2-(2'-
Hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)5,6-dichlorobenzotriazole, 2
-(2'-hydroxy-5'-tert-butylphenyl)
Benzotriazole, 2-(2'-hydroxy-
3'-methyl-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chloro-benzotriazole and 2-(2'-hydroxy- 5′-phenylphenyl)-5-chlorobenzotriazole,
2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-
(2′-hydroxy-4′-octoxyphenyl)benzotriazole and 2-(2′-hydroxy-
3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole is effective. The amount of the ultraviolet absorber as described above can vary widely depending on the type of ultraviolet absorber, the type of thermoplastic resin used, the thickness of the film or plate, etc. In order to substantially block the transmission of ultraviolet rays of 340 nm and below, preferably 360 nm and below, particularly preferably 380 nm and below, the combination of the amount of the ultraviolet absorber and the thickness of the resulting film or plate must be adjusted. In the formula below, 15≦AB≦600, preferably 20≦AB≦400, where A is the amount of ultraviolet absorber (PHR)
, B is the thickness of the film or plate (μ)
It has been found that it is particularly preferable that the relationship expressed by the following is satisfied. Here, PHR means parts by weight per 100 parts by weight of thermoplastic resin. In addition, the amount (A) of the UV absorber varies depending on the type of thermoplastic resin and UV absorber, but in general
0.001~5PHR, especially for film 0.1~5.0PHR
A range of is suitable. In addition to the ultraviolet absorber, the thermoplastic resin used in the present invention may optionally contain other conventional resin additives, such as plasticizers, lubricants, antioxidants, light stabilizers, antistatic agents, and antifogging agents. Small amounts of agents, heat stabilizers, dyes, pigments, and other dust-preventing agents may also be included. Furthermore, the thermoplastic resin film or plate used in the present invention, or the above-mentioned molded article, can be produced by various methods known per se, such as a calendering method,
Melt extrusion method such as inflation method, press method,
It can be manufactured using a solution casting method, an injection molding method, or the like. Furthermore, in order to prevent deterioration of the physical properties of the film, it may be coated with another resin or laminated with another film. The film or plate formed in this way is
The thickness can be varied over a wide range depending on the intended use, but generally a range of 15 to 5,000 microns, particularly 20 to 3,000 microns, is suitable for the purpose of the present invention. The film or plate can also be used by laminating it on other synthetic resin films, sheets, glass, etc. for the purpose of reinforcement, etc., if necessary. Furthermore, the thermoplastic resin film or plate formed as described above, particularly the film, may be reinforced with reinforcing fibers such as glass fibers, wire mesh, or reticulated fiber structures. In addition, in order to prevent the transparency of the material of the present invention from decreasing due to the adhesion of dust, if necessary, the surface may be treated with a chemical that prevents dust from adhering, or other synthetic resin containing such a chemical may be laminated. Alternatively, it may be coated. "Useful plants" as used herein are
Standard Primary Color Illustrated Works - Volume 13, Useful Plants (Published by Yukusha, written by Shiro Takashima) Table of Contents - This refers to the useful plants listed on page ~, and among the plants that are currently useful for human beings to maintain their food, clothing, and shelter, humans This refers to plants that are cultivated and used under protection and management. For reference, typical useful plants to which the method of the present invention can be applied are listed below. (1) Agricultural crops (a) Food crops Cereals Rice, wheat, corn, millet Beans Soybeans, adzuki beans, peanuts, edamame, green beans, peas Potatoes Sweet potatoes, potatoes, taro, ginger (b) Craft crops Oils Flax, olives , rapeseed, sesame Favorable materials Chia, coffee, leaf tobacco, hops, cocoa Medicinals Poppy, pepper, pyrethrum Sugars Sugarcane, sugar beet, Jerusalem artichoke Fibers Linseed, hemp, cotton, yam, loofah Paper materials Scots pine, Sakhalin fir, Mulberry, Japanese mulberry, Gampi Starches, konjac, cutlet mackerel Dyes, eye, safflower (c) Fodder/green manure crops Pastures Clover, vetch, grass Green crops Teosinte, sorghum, adlay Root crops for food Turnip, rutabaca (2) Horticultural crops (d) Vegetables Leaf and stem vegetables Spinach, celery, chives, Japanese cabbage, cabbage, lettuce, Chinese cabbage, Chinese cabbage, broccoli, green onions, parsley, Japanese mitsuba, Japanese daisy, Japanese cabbage, garlic, asparagus,
Japanese cabbage, taro, spring onion Root vegetables Onions, taro, radish, carrots, turnips, burdock Fruit vegetables Strawberries, peas, green peppers,
Melon, watermelon, tomato, cucumber, eggplant, pumpkin, melon,
Chives, okra (e) Fruits Apples, loquats, pears Stone fruits Peaches, plums Grain fruits Chestnuts, walnuts Vines Grapes Citrus tangerines, lemons Shrub fruits Strawberries, currants (e) Flowers chrysanthemums, Among the above-mentioned useful crops, the crops that can exhibit excellent effects in the method of the present invention include grains, beans, potatoes,
Preferable foods are grains, sugars, starches, leafy vegetables, root vegetables, fruit vegetables, shrubs, and flowers, especially grains, beans, potatoes, grains, and leafy vegetables. ,
Root vegetables, fruit vegetables, and flowers are preferred, especially beans,
Potatoes, leaf and stem vegetables, root vegetables, fruit vegetables, and flowers are preferred. Examples of specific useful crops include wheat,
Corn, soybeans, adzuki beans, peanuts, edamame,
Green beans, peas, sweet potatoes, potatoes,
Taro, Japanese ginger, rapeseed, leaf tobacco, sugar beet, sugarcane, konjac, pearl barley, spinach, celery, green onion, chive, Japanese cabbage, parsley, lettuce, Chinese cabbage, Japanese cabbage, broccoli, Japanese cabbage, Chinese cabbage, Japanese cabbage, garlic, asparagus, Japanese sweet potato, taro, spring onion, onion, taro, radish, carrot, turnip, burdock, strawberry, green pepper, melon, watermelon, tomato, cucumber, eggplant, pumpkin, gourd, chili pepper, okra, chrysanthemum, carnation, rose, chili pepper, and Among them, tomatoes and radish are the most preferred. When cultivating useful crops under mulching while being covered with the mulching covering material according to the present invention, the mulching cultivation is generally carried out under the covering with the mulching covering material during the period from the germination time or planting time of the useful crops to the end of harvest. is preferable. In addition, the cultivation method may be open field cultivation, greenhouse cultivation, or tunnel cultivation, but in greenhouse cultivation and tunnel cultivation, it is recommended to cover the greenhouse, tunnel, etc. with a UV-shielding film and use it in combination with the mulching coating material of the present invention. This further enhances the effect of the invention. Next, the present invention will be further explained with reference to Examples and Reference Examples. Examples 1 to 4, Comparative Examples 1 to 3 [Preparation of film] (Manufacture of film) (1) 100 parts by weight of polyvinyl chloride, 45 parts by weight of dioctyl phthalate (plasticity), 1.5 parts by weight of dibutyltin maleate (thermal stabilizer) parts, zinc stearate (thermal stabilizer) 1.0 parts by weight, stearic acid (lubricant)
0.1 part by weight and 1.0 part by weight of sorbitan monolaurate (dropless agent) are thoroughly mixed with each other, and the mixture is melt-extruded at 200°C using an extruder to form a colorless product with a thickness of 30μ that substantially shields wavelengths of 290 nm or less. A transparent film was obtained. This film was hereinafter referred to as film a. (2) Film a was prepared except that 2.1 parts by weight of 2-(2'-hydroxy-3',5'-ditertiary butylphenyl)benzotriazole (ultraviolet absorber) was added to the composition of film a. In the same manner as above, a colorless and transparent film with a thickness of 30 μm that blocks light below 350 nm was obtained. This film was hereinafter referred to as film b. (3) In addition to the composition of film a, 2-(2'-hydroxy-3',5'-ditertiary butyl phenyl)
-5-chlorobenzotriazole (ultraviolet absorber) 1.5 parts by weight and 2,2'-dihydroxy-4
-Methoxybenzophenone (ultraviolet absorber)
A colorless and transparent film (thickness: 30 μm) that substantially shields light of 380 nm or less was obtained by the same process as film a by blending 1.7 parts by weight, and was hereinafter referred to as film c. (4) In addition to the composition of film a, 2-(2'-
1.2 parts by weight of hydroxy-3',5'-ditertiary-butylphenyl)-5-chlorobenzotriazole (ultraviolet absorber) and 2.0 parts of yellow dye (trade name: Diamond Resin Yellow PYC, manufactured by Mitsubishi Kasei)
A yellow, transparent film (thickness: 30 μm) that shields light of 400 nm or less and was obtained by the same process as film a by blending parts by weight was hereinafter referred to as film d. Film perforation Films a to d obtained in the above film production
A small circular hole was made in each of the materials as shown in Table 1, and a mulching film was prepared according to Table 1. These films will hereinafter be referred to as Examples (mulching films 1 to 5) and comparative examples (mulching films 6 to 15).

【table】

[Table] Reference Examples Reference Examples 1 to 5, Reference Comparative Examples 1 to 10 In mid-March, nitrogen, phosphoric acid, and potassium were uniformly applied as base fertilizers so that each amount was 7.2 kg/10 a, and the land was tilled and leveled. We made 15 ridges so that they were 120 cm wide and 10 m long and watered them thoroughly. Films Nos. 1 to 15 prepared in Examples and Comparative Examples were each covered with mulch in late March. In early April, I planted 3 daikon radish (early maturing varieties of Nagakushun Makimi) in each hole with a row spacing of 30 cm and a plant spacing of 35 cm.
~5 seeds were sown at a time and thinned out in late April. Harvest all at once in early June and report the results.
Shown in 2. Incidentally, the growth of radish in the plots covered with film Nos. 1 to 5 was particularly faster than in the plots covered with film Nos. 6 to 15, so the harvest date was brought forward by 4 to 6 days.

【table】

【table】

Claims (1)

[Scope of Claims] 1. Substantially blocks ultraviolet rays in the wavelength range of at least 340 nm and below, and has an aperture in the longitudinal direction.
A transparent thermoplastic resin ultraviolet-shielding mulching coating material characterized by having small pores of 1.5 m/m or less and a porosity of 0.01% or more and less than 1%. 2. The ultraviolet-shielding mulching coating material according to claim 1, which substantially blocks ultraviolet rays in the wavelength range of at least 360 nm and below, and has the small pores. 3. The ultraviolet-shielding mulching coating material according to claim 1, which substantially blocks ultraviolet rays in the wavelength range of at least 380 nm and below, and has the small pores. 4. The ultraviolet-shielding mulching coating material according to claim 1, which substantially blocks ultraviolet rays in the wavelength range of at least 400 nm and below, and has the small pores. 5. Claim 1 which substantially blocks light in the wavelength range of at least 420 nm and below, substantially transmits visible light in the wavelength range of 500 nm and above, and has the small hole. UV-shielding mulching covering material as described.