JPH0641524A - Wavelength changing material for agriculture - Google Patents

Abstract

PURPOSE:To provide the material comprising a specific pyrazine-based com pound, useful for greenhouse, having high fluorescence intensity retention ratio and a function of promoting photosynthesis of plant by absorbing sunlight and green light of artificial light source and converting the light rays to ones having a longer wavelength. CONSTITUTION:A PE film, etc., is blended with preferably 0.05-0.5 pyrazine-based compound of the formula [each of R1 to R4 is H, a (substituted) alkyl, (substituted) alkenyl of (substituted) alkynyl, etc.] to give the wavelength changing material.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention has a function of promoting photosynthesis of plants by absorbing green light of light energy of artificial light sources used in sunlight and plant factories and converting it into light of a longer wavelength. Regarding agricultural materials.

[0002]

2. Description of the Related Art In recent years, institutional horticulture for cultivating useful plants in greenhouses or tunnels has become widespread, and the yield and quality are dramatically improved compared to open-field cultivation, so that stable vegetables and fruits can be supplied. It is playing an important role. The greatest significance of institutional cultivation is to keep the heat inside the house and tunnel, and to protect the plants from damages such as rain, wind, insects, etc. Therefore, for vegetables, seasonal cultivation to year-round cultivation, pear, Fruit trees such as mandarin oranges, grapes, oysters, and apples are beginning to be harvested in good shape with high sugar content. On the other hand, after the widespread use of institutional horticulture, an attempt was made to convert the spectrum of sunlight into an advantageous form for photosynthesis of plants or production of growth-promoting substances, aiming for higher yield and higher quality. That is, by dissolving a fluorescent compound having a wavelength conversion function in a synthetic resin film used for horticulture, a blue-based system useful for photosynthesis by absorbing near-ultraviolet rays that are harmful to plants in some cases. Many attempts have been made to convert the light of the green to yellow type having a low photosynthetic efficiency into the light of the orange to red type having a longer wavelength. For example, the research results report of the research corporation "Agricultural light selection and utilization technology research association" (Showa 39-57) "Comprehensive research on technologicalization of utilization of light quality in facility agriculture" (February 1976, Agriculture, Forestry and Fisheries Technology Conference) The secretariat) is trying a film in which blue fluorescent substance and red fluorescent substance are dissolved in vinyl chloride, but it has been reported that the film was interrupted due to poor light resistance.

JP-B-49-16301, JP-A-52-
94345, JP-A-2-102265, JP-A-2-14
7651, Fluorescent brightener and scintillator used in JP-A-3-211053 and the like convert near-ultraviolet light into photosynthetic effective light, but have insufficient light resistance and are put to practical use for institutional horticulture. Has not arrived. Further, in JP-A-54-127945, Rhodamine 6 is used.
A sheet for converting green to yellow light into orange to red light using G is disclosed, but this dye also has poor light resistance and cannot be put to practical use.

Among the fluorescent dyes that absorb green to yellow light and convert them into orange to red light, robust fluorescent compounds such as perylene-based phosphor, coumarin-based phosphor, perinone-based phosphor, and thioindigo-based phosphor There are groups, but these have poor solubility in resin, and the Stokes shift (the interval between the absorption wavelength and the emission wavelength) is not sufficiently large, and the action efficiency is relatively low on the photosynthetic action spectrum by solar energy.
It cannot be said to have a sufficient function of effectively converting green light of 0 to 550 nm into long wavelength light.

[0005]

[Problems to be Solved by the Invention] In addition to the robustness of the wavelength conversion function as a characteristic of a preferable wavelength conversion material, (1) corresponding to a photosynthetic action spectrum, it absorbs green light of 480 to 550 nm, and orange of 560 to 680 nm -Efficient conversion to red light, (2) Large Stokes shift, (3) No significant absorption in the visible light region other than 480 to 550 nm, and the like, but these properties were satisfied. Wavelength conversion material, that is, for promoting photosynthesis,
A wavelength conversion material having a wavelength conversion function that works effectively and has practically no problem light resistance has not been reported yet. In these circumstances, the present inventors have a function to enhance the effective light for promoting photosynthesis by converting the spectrum of light of sunlight and artificial light sources used in plant factories, etc. in facility cultivation of useful plants. The purpose is to provide a wavelength conversion material for agriculture.

[0006]

Means for Solving the Problems The gist of the present invention is that the action efficiency is relatively low on the photosynthetic action spectrum.
Absorbs green light of 80 to 550 nm, 560 to 680n
m for the purpose of efficiently converting from orange to red light, having a large Stokes shift, and containing a novel fluorescent compound having no noticeable absorption in the visible light region other than 480 to 550 nm, This novel fluorescent compound, which is a wavelength conversion material, is disclosed in Japanese Patent Application No.
242321 and the compound described in “Dicyanopyrazine Derivatives” filed on Oct. 14, 1992

[0007]

[Chemical 2]

[In the formula, R ₁ , R ₂ , R ₃ and R ₄ are the same or different and each is hydrogen or an alkyl group which may have a substituent,
An alkenyl group which may have a substituent, an alkynyl group which may have a substituent, and R ₁ and R ₂ or / and R
₃ and R ₄ may together form a ring, and R
₁ and R ₂ or / and R ₃ and R ₄ are taken together,
A group of SR ₅ R ₆ (R ₅ and R ₆ are the same or different and each represents an alkyl group or an aryl group) may be formed.
Provided that R ₁ , R ₂ , R ₃ , and R ₄ are all hydrogen atoms.].

The wavelength conversion material according to the present invention is (soft, semi-rigid, hard) PVC; polyethylene; polypropylene;
Polyvinyl alcohol; polyvinyl acrylate; polyvinyl methacrylate; polyvinylidene chloride; polyacrylonitrile; polybutadiene; polystyrene; ethylene-vinyl acetate copolymer; vinyl chloride-vinyl acetate copolymer; polyvinyl butyral; polyvinyl formal;
Polyester such as PET, PBT; Polyarylate;
Polycarbonate; Polyester carbonate; Phenoxy resin; Nylon 6, Nylon 6/6, Nylon 1
Polyamides such as 1, nylon 12, MXD6 nylon; polydimethylsiloxane; polytrimethylsilylpropyne; polyurethane; ionomers; cellophane;
Soft and hard resins such as polyethylene cellophane; cellulose acetate; cellulose propionate; ethyl cellulose; nitrocellulose; can be used.
The method for producing the wavelength conversion material is not particularly limited, and is produced by extrusion molding, inflation molding, calender molding, etc. according to the melting characteristics of the resin, solvent solubility, or the resin-dissolved varnish is glass, plastic plate, reflective. It can be produced by coating a plate film or the like or impregnating a woven fabric, a non-woven fabric, paper or the like. The thickness of the resin layer containing the pyrazine compound is 10 to 300 nm, preferably 30 to 1 for both the molding film and the coating layer.
It is better to set it to 50 nm.

The concentration of the pyrazine compound dissolved in the synthetic resin is 0.01 to 2.0%, preferably 0.05 to 0.
5%. If the concentration is lower than 0.01%, the wavelength conversion function is not sufficient, and if the concentration is higher than 2.0%, the light absorption rate is large, and the effect of concentration quenching, which is a characteristic of fluorescent compounds, is exhibited. It is not preferable because the conversion efficiency is lowered and the light absorption ratio and the absorption wavelength region are too large, resulting in a strong light shielding effect.

An ultraviolet absorber, an antioxidant, a hindered amine-based light stabilizer in a kind and in an amount that does not impair the object of the present invention for satisfying other various conditions as a material for horticultural facilities,
Additives such as a lubricant, an antifogging agent, and a drip agent, and a fluorescent dye that absorbs near-ultraviolet light and emits blue light in order to promote photosynthesis in the blue light region may be added.

The synthetic resin film in which the fluorescent compound is dissolved varies depending on the refractive index of the synthetic resin.
0-80% is totally reflected at the interface with air and propagates through the film. In many cases, the trapped light has an absorption spectrum overlapping with an emission spectrum, so that part of the light is repeatedly absorbed and emitted again. At this time, since the light emission is performed by an amount obtained by multiplying a certain conversion efficiency, the energy loss becomes a size that cannot be ignored. In order to avoid such energy loss and to allow the emitted light to be effectively emitted from the inner surface of the film, for example, inorganic fine powder such as silica or alumina or fine plastic powder is blended, or the inner surface of the film is regularly Alternatively, it is preferable to perform a roughening process in which irregular irregularities are provided. Roughening is a wire brush,
It can be performed by a commonly used method such as sandblasting or embossing.

An additional effect of the present invention is an effect of controlling harmful insects by red light. As a method for controlling insect pests by light, as disclosed in JP-A-52-61581, a method of coating soil with a highly reflective film and Japanese Patent Publication No.
A typical example is a multi-film containing a red pigment that absorbs green light and reflects red light as disclosed in 58898, but since these films have low light transmittance, they spread in houses, tunnels, etc. It cannot be used as a film. In the wavelength conversion material of the present invention, since the highly soluble pyrazine compound represented by the general formula [I] is dissolved in the resin, incident light is not scattered and is efficiently transmitted, or green light is as described above. Emitted as orange to red light. The orange to red light has an action of repelling harmful insects such as beetles, aphids, and whiteflies, and thus can significantly reduce the use of pesticides in houses and tunnels. The material having a wavelength conversion function of the present invention is not only a covering material for a vinyl house but also a multi-film, a reflective (multi) film, a reflector installed so that sunlight is uniformly irradiated in the house, a plastic net, a woven cloth. It is also used for non-woven fabrics and bags for hanging fruits.

[0014]

EXAMPLES The present invention will be described in detail below with reference to examples.
In the examples, "part" represents part by weight. The fluorescence spectrum was measured using a Fluorescence Spectrophotometer Model 850 manufactured by Hitachi, Ltd. Transmittance is
It was measured using a spectrophotometer UV-240 manufactured by Shimadzu Corporation.

Example 1 (Production of Film) 100 parts of a polycarbonate resin (CALIBRE300-6: Sumitomo Nogatak Co., Ltd.) was added to methylene chloride 667.
Varnish (varnish A), CALIBRE30
0-6; 100 parts, ultraviolet absorber (Biosorb 91
0: Kaniyaku Co., Ltd., 2.0 parts of varnish dissolved in 667 parts of methylene chloride (Varnish B), CALIBRE300-
6; 100 parts, Biosorb 910; 2.0 parts, 0.2 part of a pyrazine compound in which R ₁ = R ₂ = R ₃ = R ₄ = CH ₃ in the general formula [I] was dissolved in 667 parts of methylene chloride. Each varnish (Varnish C) was adjusted and the primer-treated polyethylene terephthalate film (SG-
2. Film thickness 75 μm: Teijin Co., Ltd. was coated with a reverse roll coater and dried to obtain a dry coating film thickness of about 40 μm (including the base film thickness of about 115 μm).
m) three films A, B, C were produced. The transmittance of the film is shown in FIG. 1, and the fluorescence excitation and emission spectra are shown in FIG.

Example 2 (Production of film) 100 parts of polypropylene (Mitsui Noblen BJ4H-G: Mitsui Toatsu Chemicals, Inc.), 0.2 part of the pyrazine compound used in Example 1, UV absorber Biosorb 910;
2.0 parts were kneaded with a heat roll set at 210 ° C for 3 minutes, and then press-molded with a 70t hot press at 210 ° C to produce a film having a thickness of 0.15 mm. When the excitation and emission spectra of the film were measured, the excitation maximum wavelength was 472 nm and the emission maximum wavelength was 584 nm.

Example 3 (Lightfastness of Film) The film C produced in Example 1 was used on October 18, 1989.
As a result of natural exposure for 1 year from October 19 to 1990, the fluorescence intensity retention rate was 68%.

Example 4 The varnish-coated side of the film produced in Example 1 was coated with No. 8
After roughening with 0 sandpaper, small houses of about 10 m ² each were assembled with this surface inside. Seeding on May 13, 1991 (medium: WEDGE OASIS 5
631; Nippon Soda Co., Ltd.) cucumber (Tenma) and lettuce (Sacramento) seedlings in pots (Inawashiro Hayama soil 5 liters, ripe compost 5 liters, dicyan (Showa Denko KK) 7
g, and mixed with 51 g of gemstone was used) (June 7
Then, on June 11, 10 pots each of cucumber and lettuce were moved to each house to start the experiment. For irrigation, set an automatic irrigation device and once a day at around 9:00, 5
00-600ml / pot (1000m after 23rd July)
1 / pot) watered. Fertilization was performed at appropriate intervals using OASIS liquid fertilizer (Nippon Soda Co., Ltd.), Fuchin Gold (Nippon Soda Co., Ltd.), or the like. No pesticides were used. The test runs until August 21st,
The results of the cucumber and lettuce harvest weight surveys were recorded.
The results are shown in Table-1 and Table-2.

[0019]

[Table 1]

[0020]

[Table 2]

Example 5 (Production of Reflective Film) Instead of polyethylene terephthalate, a reflective film (polyethylene film: Silver Polytow N, 0.1) was used.
Reflective films A ′, B ′, and C ′ were manufactured in the same manner as in Example 1 using 0 mm; Tokan Kogyo Co., Ltd.

Example 6 The coated surface of the reflective film produced in Example 5 was No. 80
After roughening with sandpaper, the reflective mulch film was spread in the north and south with this side facing up. Seeding on June 13, 1991 (medium: WEDGE OASIS 563
1; Tomato seedlings (variety: Saturn) that were made by Nippon Soda Co., Ltd. were transplanted to the above reflective multi-film on July 4, 15 strains at 30 cm intervals in a row, and the test was started. Harvesting was performed up to the fourth fruit cluster. The test results are shown in Table-3.

[0023]

[Table 3]

[0024]

The present invention has the following effects, and its practical utility is extremely large. (1) The wavelength conversion material for agriculture of the present invention can convert green light centered at 490 nm, which has low photosynthetic efficiency, into orange to red light centered at 590 nm. (2) The pyrazine-based compound used in the present invention is stable to light, and by using an additive such as an ultraviolet absorber in combination, it is possible to maintain the fluorescence intensity retention rate after expansion for one year at 60% or more. it can. (3) By cultivating vegetables, flowers and fruit trees in a house using the wavelength converting material of the present invention, vegetables and flowers have a short period of time, high yield, and fruit trees have high sugar content and high quality fruits. Can be harvested. (4) Pests can be controlled by orange-red light having a wavelength of 590 nm which is emitted by the wavelength conversion material of the present invention.

[Brief description of drawings]

FIG. 1 Spectral transmittance of films A, B, and C

[Fig. 2] Excitation and emission spectrum of film C (a) ... Excitation spectrum for 590 nm emission (b) ... Emission spectrum by 492 nm excitation

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Takahashi 345 Yanagimachi, Takada, Odawara City, Kanagawa Nihon Soda Co., Ltd. Odawara Research Center

Claims (1)

[Claims] 1. Chemical formula 1 [Wherein R ₁ , R ₂ , R ₃ , and R ₄ are the same or different and each represents hydrogen, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent An alkynyl group, and R ₁ and R ₂ or / and R ₃ and R ₄ may be taken together to form a ring, and R ₁ and R ₂ or / and R ₃ and R ₄ may be taken together. So, = SR ₅ R ₆
(R ₅ and R ₆ may be the same or different and each represents an alkyl group or an aryl group). However, R
_1. Excluding compounds in which ₁ , R ₂ , R ₃ , and R ₄ are all hydrogen atoms], a wavelength conversion material for agriculture, comprising a pyrazine compound.