KR20080055175A - Phosphor with red color luminescence, preparation method and multi-layer light transforming agriculture film for hotbeds and greenhouses - Google Patents

Abstract

A red light emitting phosphor is provided to ensure high spectrum radiation intensity and high photonic efficiency for transforming short-wave UV radiant rays into biologically active red light radiant rays. A red light emitting phosphor is based on an oxy-sulfide of a rare earth element Zr and/or Hf, and an activator. The phosphor is at least one selected from the group comprising oxy-sulfur-fluorides of La-Y-Zr, Hf having the following formula of (La_(1-x-y-z)Y_xA_yMe_z^(+4)O)_2 S_1(F^(-1))_2z, wherein x ranges from 0.001 to 0.2, y ranges from 0.01 to 0.2, z ranges from 0.001 to 0.005, the activator A from many elements is Sigma(TR^(+3) = Eu, Sm, Gd, Tb)+(TR^(+4)=Rr^(+4)), Re is a rare earth metal, and Me^(4+) is Zr^(4+) and/or Hf^(4+).

Description

Red luminescent phosphor, manufacturing method thereof and multi-layered light-transformation agricultural film for hotbeds and greenhouses {PHOSPHOR WITH RED COLOR LUMINESCENCE, PREPARATION METHOD AND MULTI-LAYER LIGHT TRANSFORMING AGRICULTURE FILM FOR HOTBEDS AND GREENHOUSES}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rare earth phosphor and a method for producing the same, which are used as photo-conversion material technology, namely active light emitting pigments, phosphors for color cathode ray tubes (CRTs), and photoluminophors for light emitting lamps. The present invention relates to a multilayer light-conversion agricultural film capable of changing the solar spectral content received by a plant by applying to a greenhouse, a hotbed or a greenhouse film and using it as an active filler for a light-conversion material of a polymer film or a nonwoven fabric.

In general, the transparent agricultural film used polyethylene, PVC or polypropylene, which can control a stable micro-climate (micro-climate) with a temperature increase effect of 2 to 4 ℃, and with the increase of greenhouse utilization, Conversion films have been used, and now, light-conversion agricultural films have been used. The use of such films protects crop seeds and crop growth from severe overheating that occurs in the cold and summer seasons.

The wavelength conversion mechanism of these materials allows the particles of inorganic phosphors to produce short wavelengths of sun radiation, mainly UV light (the spectrum of UV light is about 6% of the total solar spectrum in the middle hemisphere of the earth). It converts it into red light radiation that is active in photosynthesis. The photosynthetic reaction was examined in detail and precisely in the sixties of the nineteenth century, but even earlier, in 1869, Russian scientist K.A. Timiryazev proposed the regulation of the photosynthetic reaction.

C₆H₁₂O₆ + 6O₂ ↑6CO ₂ + 6H ₂ O

C ₆ H ₁₂ O ₆ + 6O ₂ ↑

This approach belongs to spectrochemistry. Timylyazeb investigated the absorption of carbon dioxide by green leaves according to different wavelengths of light. Timylyazef was the first person to observe the absorption curve of carbon dioxide by green leaves from the air. The carbon dioxide absorption curve shows two peaks in the violet-blue region and the dark-red region of the visible spectrum.

It was found that the uptake of carbon dioxide from the air in the green leaves of plants was markedly increased in the red light in the short or long wavelength region compared to the green light. Since this significant discovery by Russian scientists, the optical wavelength characteristics of chlorophyll (chloroplasts) have been confirmed several times by 20th century Emerson (Zteile, R. Emerson) and others. Emerson also found that the photon effect of different light wavelengths on plant photosynthesis is non-equivalence. The photon effect of photosynthesis is characterized by the number of oxygen molecules generated, which is proportional to the number of photons absorbed by the chloroplast.

The photon effect on the chloroplast at 480 nm and green wavelength drops to half. In the 580 to 680 nm region, photosynthesis was almost constant and a very high photon effect was observed. At λ = 680 nm, the photon effect on the chloroplast drops sharply, and for the light wavelength of λ> 700 nm, the quantum effect is almost eliminated despite the strong absorption of the dark red light of the chloroplast (chlorophyll dye). The so-called Emerson synergistic effect is that the photosynthetic activity increases significantly when short (light) red light (wavelengths with λ = 650 nm and λ = 700 nm) is added to long (dark) red light, and oxygen production rates are rapidly increased. Increases. This fact suggests that balanced light wavelengths are important for plant photosynthesis in the pigment subsystem of green plants.

Timy Ryzev's earlier discoveries have long been the basis for scientific research in the fields of basic agriculture and applied agriculture. A special technology sector called plant lighting technology has been developed, which is the intensity and duration of the lighting in the greenhouse, the type of spectrum and the technology of plant growth. The lighting of the plants in the greenhouse was the use of special incandescent, discharge and luminescent lamps. This research enabled large gardening companies to grow plants and harvest high yields of vegetables, berries, flowers and sprouts during the fall, winter and spring. However, the sharp rise in electricity costs for greenhouse lighting has led to a surge in crop growth costs. Therefore, for a limited time, the number of polymer films covering the steel structure of the summer-spring greenhouse increased.

The polymer film material is 1) high mechanical durability and tensile strength to prevent breakage due to wind pressure, 2) transparency to visible light of sunlight, 3) high absorption of infrared radiation having a wavelength of 10 to 25 microns in the soil in the greenhouse And radiation, 4) UV radiation emitted by the sun. By absorbing the mid-wavelength region, the emergence of ozone holes necessitated requirements such as the protection of plants from increasing UV-sunburn in the atmosphere, and a greenhouse polymer film having the above-mentioned main line has been proposed. Patent 2094978) It is also known that organic-glass has been used as the translucent cover of the greenhouse. (Russian Patent 2131661) All of the translucent covers above do not affect the light wavelength in the greenhouse. On the other hand, as a greenhouse coating containing a composite composition of europium nitrate and 1,10-phenanthroline or 2,2'-dipyridine or 4,4'-dimethyl-2,2'-dipyridine and also paraffin Polymer films are also known (Soviet Federal Patent 1780309).

Horticultural polymer films containing thermoplastic polymers, kaolin or metallic aluminum or metallic copper, blue or red pigments having the same range of luminescence are also known (Russian Patent 2053247). On the basis of europium (Eu) -compounds, polymer films for greenhouses containing thermoplastic polymers, light stabilizers and inorganic phosphors have been proposed (Russian patent 2127511). Phenozan-23 is used as the light stabilizer, strontium sulfide activated by europium or strontium activated by europium and calcium sulfide activated by europium or strontium sulfide activated by europium, dysprosium and / or terbium. Or strontium and calcium sulfide activated with europium, dysprosium and / or terbium. Such film materials absorb light in the UV region of the solar spectrum in the range 290-330 nm or 400-440 nm and emit light in the red spectral range (580-760 nm) with a maximum at 618-680 nm. . Polymeric materials with photoconversion materials may have long term (up to 2 hours) afterglow.

A light-converting polymeric film composition comprising a light transmitting (thermoplastic polymer) and a photoactive mixture, an inorganic component represented by the following general molecular formula, is known from the patent (Russian Patent 205999):

[(La _{1 - x} Eu _x ) O] _m (Lig) _n

Where

when m and n are 1, Lig is F ⁻ , Cl ⁻ or Br ⁻ ,

m is 2 and when n is 1, Lig is _{^{S 2 -, SiO 4 2 -}} , or PO ₄ ^{3 -,} and

The component ratio (wt%) in the final film is from 0.02 to 5.0 wt% of the photoactive mixture, with the remainder translucent polymer.

The advantage of the greenhouse film with the above-mentioned material is that it can be mass-produced. Despite the advantages of mass production of the polymer-inorganic filler composition, greenhouse films have a negative effect on the growth of legumes and cereals because the composition only emits spectrum of orange-red light as secondary light, and in fact does not emit blue light. Inorganic oxy-sulfide-based films have the disadvantage of requiring a large amount of additives (0.2 to 0.5%) in order to increase the light conversion rate.

The polymer composition, called "Red light", improved in 1996, also lacked emission intensity in the red light range and had little effect on plant growth. The reason for this low-efficiency is not to optimize the error in the film production process, the lack of dispersion techniques in the polymer of the filler (light converting agent) and the composition of europium-yttrium oxy-sulfide which emits orange-red light. The spectra of the europium-yttrium oxy-sulfide composition consisted of a plurality of spectra with different peaks at λ max = 585 nm, 616 nm and 626 nm, and the wavelength width between the peaks (40 nm) was uneven.

Despite the many advantages of greenhouse films filled with oxy-sulfide phosphors, these films suffer from certain disadvantages due to the fillers of the polymer matrix and the phosphor large particles. That is, low-concentration (less than 1 x 10 ³ particles per cm ² of film) fluorescent agent, insufficient luminous luminance of agricultural polymer film, and large consumption of film material (usually 1 m film) for the production of greenhouse film 150 g per ^two ), and is due, in particular, to the use of phosphors with large particles as the active filler (average particle size: d _av = 10-12 μm).

Based on the yttrium-uropium oxy-sulfide by developing special synthesis methods using raw materials and semi-finished products as described in the Russian patent (A. Malova RU Patent 2049106 dated 29/05/1991) to minimize the disadvantages of the above known phosphors There was an attempt. The patent document developed by the present inventors makes it possible to increase the phosphor emission luminance by 10 to 15%, but this is due to the significant increase in the number of particles per unit area.

Accordingly, the present invention has been made to solve the above conventional problems,

New chemistry of phosphors with high spectral radiation intensity and high photon efficiency in converting short wavelength UV radiation into biologically active red light radiation to improve low-concentration and relatively small luminescence brightness of oxy-sulfide phosphors in greenhouse films It is aimed at the synthesis of the composition.

It is another object of the present invention to provide an inorganic phosphor that has an average particle size corresponding to the wavelength of emitted red or deep red light.

It is another object of the present invention to provide a greenhouse film filled with small phosphors having high chemical and mechanical factors.

Red luminescent phosphor of the present invention, a method for producing the same and a multi-layered light-conversion agricultural film for greenhouses and greenhouses for achieving the above object,

The oxy-sulfide-based phosphor material of the rare earth element is characterized by a mixture of lanthanum-yttrium-zirconium and / or hafnium having the molecular formula below.

Molecular formula

(La _{1 -xy- z} Y _x A _y Me _z ⁺⁴ O) ₂ S ₁ (F ^-1 ) _2z

Where

x is 0.001 to 0.2;

y is 0.01 to 0.2;

z is 0.001 to 0.005;

A is ∑ (TR ⁺³ = Eu, Sm, Gd, Tb) + (TR ⁺⁴ = Rr ⁺⁴ );

Me ⁺⁴ is Zr ⁺⁴ and / or Hf ⁺⁴ .

Hereinafter, briefly described the nature of the phosphor proposed in the present invention. First, the phosphor of the present invention, which is distinguished from conventional phosphors and widely used Y-Eu oxy-sulfides, is a solid solution of oxy-sulfides of La and Y, in which group IV elements such as Zr ⁺⁴ and / or Hf ⁺⁴ Is added. The addition of such a Group IV element is La ^{+ 3,} or Y ^{+ 3} ion size is enabled, the light having a small Zr ^{+ 4} and / or the introduction of Hf ^{+ 4} ions in the composition λ = 350 to 405 nm range as compared to the fluorescent radiation intensity The rapidly increasing effect of is the basis of this discovery. Most likely, the higher and smaller ionic charge of these elements significantly increases the crystalline electrostatic field in the inorganic matrix of oxy-sulfur fluoride, which leads to an increase in brightness.

Second, according to the invention is of the composition 3 in the anion sublattice (sub-lattice) La ^{3 + 3 +} 4 and Y is zirconium ion in crystal consisting of Zr ^{+ 4} and / or hafnium Hf ions in order to uniform distribution of ⁺⁴ It has been found that fluorine ion F ^1- must be introduced. The exact location of these fluorine ions within the definite knot of the anion sublattice of oxy-sulfur fluoride should be measured separately. For now, a grid point location of the fluoride ion and also the formula O ₀ ^{2 -} can assume a portion of the fluorine ion + oxygen ions substituted in accordance with the _{^{F 0 1- - = F i 1}} . Instead of La ^3+, or Y ³⁺ ions may be expressed by the partial substitution of Zr ^{+ 4} ions to charge balanced formula as follows:

_{^{(Zr y 4 +) ° =}} F i 1 - or _{^{(Zr y 4 +) = (}} F 0 1-) + F i 1 -

These equations also Group 4 elements (Zr ^{4 +} and / or Hf ^{4 +),} and also the inherent ion (interstitial ion) F _i ^{1 -} increase in the crystal tension (結晶場力) of the base structure of the fluorescent substance by the additional introduction of Cause.

Third, the base of the proposed phosphor is activated not only by oxy-sulfide Eu ions, but also by ions of samarium Sm ⁺³ , gadolinium Gd ⁺³ , terbium Tb ⁺³ . Along with the trivalent ions as the activator and the sensitizer as the basis of the proposed phosphor, in particular Pr ^{4 +} ions can be used in the oxidation state +4 _---> Pr ^{4 +} = Tr ^{4 +} . Such additional active and auxiliary active ions introduced into the oxy-sulfur fluoride lattice also enhance phosphor luminescence brightness. According to the data obtained, the increase in phosphor brightness is as follows:

- introduction of the La ^{3 +} increase the brightness to 30 to 50%;

The introduction of O ² -substituted F ^{1 -} as lattice ions increases by 10-20%;

- La ^{3 + 3,} or Y ⁺ Zr ^{+ 4} and / or the introduction of Hf ^{4 +} ions substitute a part increases from 5 to 15%;

- Pr ^{4 +} and Tb ^{3 +} ions are introduced in to increase the brightness to 25 to 30% as an additional active agent, and the emotions;

- Sm ^{+ 3} and Gd ^{+ 3} the introduction of ions to increase the brightness by 5 to 15%.

When oxy-sulfides of yttrium and lanthanum-zirconium are activated with europium, samarium, terbium or praseodymium (Pr), the overall brightness increases by 90-140%. It was observed that the 100% luminance improvement over the Y ₂ O ₂ S: Eu standard value was due to the ion concentration.

0.050 <Eu / (Pr + Sm + Eu + Gd + Tb) ≦ 0.15.

The main radiation wavelength ranges from λ = 615 nm to λ = 628 nm, with a wavelength λ = 705 to 715 nm spectrum in the secondary dark red region. It should be noted that such long wavelength radiation contributes to the role between plants (stems, leaves, roots) and the synthetic organs of green plants, which is a further need.

Nevertheless, it was shown that the light spectrum of the proposed phosphor shifted significantly in the long wavelength range of 390 nm to 410 nm. The proposed phosphor is activated on the phosphor, while the concentration of ∑ (Eu + Sm) ratio for the sum of all rare earth cations ∑ (TR ^{3 +} ) is 0.06 <(Eu + Sm) / ∑ (TR ^{3 +} ) ≤0.095 The full spectrum of light is in the UV range from λ = 320 nm to 410 nm, which is distinct from other fluorescent agents.

One important feature of the proposed phosphor is that the particle size corresponds to the light wavelength irradiated. The inventors have found that the median particle size d ₅₀ is 0.4 to 0.8 μm for particles of the phosphor comparable to the wavelength of the irradiated light in the wavelength λ = 628 nm to λ = 715 nm range or average λ = 0.65 microns. At the same time, the maximum diameter of the particles was found to be d _max = 6 to 8 µm or less. It should be noted that the irradiance of the markedly reduced new substance of the phosphor particles was increased 1.8 to 2.4 times compared to the sample having d ₅₀ = 10 to 12 μm. This significant increase in the brightness of the phosphor is the result of a novel process for preparing phosphors from oxy-sulfur fluorides of La-Y-Eu-Zr.

Different methods are known for producing phosphors based on oxy-sulfides and / or oxy-fluorides of rare earth elements. The basis for these methods is a complex of MeSn (n = 5-10, Me = K or Na) at temperatures between 1100 and 1250 ° C, which is a high temperature reaction between the Y-Zr primary oxide (oxalate) and elemental sulfur. . This reaction typically takes place in closed alumina or free carbon crucibles and is essentially reacted in a reducing atmosphere to prevent elemental sulfur combustion with the oxygen. Hydrogen fluorides obtained under thermal decomposition of ammonium di-fluorides reacting with primary Y-Eu oxides are used in place of elemental sulfur in the preparation of oxy-fluorides.

Such a manufacturing method and a product manufactured therefrom which are widely used have many disadvantages as follows.

Take of 4-8 hours of synthesis time.

Large swelling of sulfufrizing and / or fluoridizing agents, 2.5 to 3 times greater than stoichiometric values.

Destruction of the crucible-reactor due to corrosion of alkali or fluorine compounds in the synthesis process.

A very important disadvantage of the known process for producing oxy-sulfide phosphors is the poor dispersion of the synthesized materials. When primary Y-Eu oxides having a particle size d ₅₀ = 4 to 6 μm are used as raw materials, the phosphor particles have a particle size of this level or more. However, the particle size increases significantly during the synthesis process, usually up to d ₅₀ = 8 to 10 μm. The maximum size of the particles is 25 to 30 μm. Such large particles further exacerbate the mechanical properties of the polymer film, such as breaking strength and tensile strength, as discussed above.

The primary object of the present invention is to eliminate the aforementioned disadvantages of known high temperature methods of phosphor production. The newly proposed method should be able to synthesize ultra-high dispersion phosphor particles. In the present invention, in the method for producing a phosphor based on the oxy-sulfur-fluoride of the rare earth element and the group IV element, the co-deposition of the hydroxide is 80 ° C. or less from the nitrate and / or acetate solution. temperature and pH> is made in the second pH of, sulfide, and the reaction with the fluoride takes place at a temperature of 200 to 900 ℃ the initial particle size deposited to a hydroxide of the d ₅₀ = 0.050 ㎛ to d ₅₀ = 0.10 ㎛ to be.

It should be noted initially that the hydroxide obtained from the initial nitrate or acetone solution is used as the primary product in the proposed method. Hydroxides are synthesized generally at a concentration of 0.5-4 mole / liter of hydroxide under a hydrogen ion concentration of pH> 2 in solution. During this operation, the inventors found that the higher the acidity of the primary solution, the greater the loss of the primary reagent, especially for the lanthanum compound, whereas higher hydrogen ion temperatures above 5 resulted in co-deposited Further degradation was found to occur. A concentrated ammonia solution (about 20%) is used for co-deposition of the hydroxides, which is reacted by sufficiently mixing with the primary nitrate solution in the reactor. The primary solution has an optimum deposition temperature of 75 to 80 ° C. and an additional loss of the first reactant occurs when the temperature is increased. Lowering the deposition temperature to 40 ° C. increases the particle size of the hydroxide and aggregates the particle to 1 μm.

Concurrent - deposition, for example, compound (? La Y _{0 .5 0 .4 0 .09} Eu Gd Tb _{0 .005 0 .005)} (OH) ₃ nH ₂ O for analysis any bond between the impurity Y and La ions It appeared to not exist. Namely, [La] / [Y] = 1.25 under the concentration ratio [Eu] / [La] + [Y] = 0.1 of Eu ions. Traditional photo-settling methods make it difficult to analyze the dispersion of co-deposited hydroxides. Therefore, a laser diffraction apparatus was used for the dispersion analysis to accurately measure particles having a minimum size d = 0.01 μm. Such a device is a German company "Friche-Analisette-2000" or a similar device of a Chinese company (for example "Sensing").

The co-deposited hydroxide obtained is dried in an oven at 105 ° C. to remove absorbed water. These hydroxides are light white materials in the form of extruded briquettes or plates of up to 10 mm in thickness and are lightly ground in a rotary mill or mixed and ground with a sulfing or fluoring material. It is not only the great advantage of the proposed method for producing such oxydisulfide phosphors, but many thio-urea (NH ₂ ) ₂ C = S, thioacetoamide CH ₃ CSNH ₂ and ammonium thiocyanate NH ₄ CNS, etc. It is different from other methods in that is used as a sulfide raw material of -2 and a number of NH ₄ HF ₂ or ammonium compounds of NH ₄ BF ₄ are used as fluoride, wherein the mass ratio of sulfide, fluoride and rare earth elements between the hydroxides is 0.5 : 4: 1 to 2: 4: 1.

The proposed method can be described briefly. First, it is to be noted that there are no cations of Group IA in the materials in the crucible, ie sulfide and fluoride materials which accelerate the corrosion of molten alumina or free carbon. The second important feature is the change in the oxidation value of the sulfide agent. In the production process for known oxy-sulfur-fluorides, elemental sulfur S ° or sulfur dioxide has an oxidation number of 0 or +4. In the proposed process, the sulfur oxide value of the sulfide agent corresponds to -2 in the following molecular formula:

Thiocyanate NH ₄ ⁺ -SC = -N of ammonium

One important feature of these materials should be noted. All of these materials have low melting temperatures, with Tm = 168 ° C. for (NH ₂ ) ₂ CS, of thioacetoamide CH ₃ CS-NH ₂ . Occation Tm = 108.5 ° C., Tm = 149.5 ° C. for ammonium thiocyanate NH ₄ SCN. This is an experimental fact that there is already a first stage sulfonation reaction in the sulfonated material melting process at T = 200 ° C. It has been shown that diffusion of S- ² ions occurs from the surface melt of the material from the liquid melt of the material and does not occur diffusion limiting phenomena which are usually characteristic of solid or liquid phase reactions.

Subsequent steps of the continuous chemical reaction may be as follows:

It should be noted that gaseous substances of type H ₂ O, NH ₄ OH and CO ₂ are formed in the decomposition of the hydroxide and sulfonated compounds resulting in the conversion of the oxidizing atmosphere to a neutral or reducing atmosphere in the vessel with the initial reactants. . The decomposition reaction of fluorinated substance is similar to that of sulfide decomposition reaction. For example, the present inventors confirmed that the decomposition reaction proceeds to NH ₄ HF ₂ : NH ₄ HF ₂ → NH ₃ + 2HF ↑, whereas NH ₄ BF ₄ → NH ₃ + HF ↑ + BF ₃ ↑. .

The optimum weight of the reactant introduced into the crucible-reactor was experimentally confirmed the composition of the co-deposited mixture of a mixture of 1 mass of fluorinated material, 2 masses of hydroxide and 4 masses of sulfide. In the experiments of the present inventors, 400 g of rare earth elements and group IV elements, 400 g of sulfonated materials such as thioacetoamide, and 100 g of ammonium bifluoride were placed in a 1000 ml alumina crucible. The crucible-reactor can be densely charged into the reactor. Subsequently, alumina mineral cotton woven fabric and a single layer of de-ash activated carbon were placed on top of each crucible-reactor. This is sufficient to completely isolate the reactants that will be heated from the oxygen in the ambient air. The alumina crucible was covered with an alumina lid on top. The crucible is heated with SiC. Maintain the following reaction temperatures:

20 ° C.-100 ° C. heating rate 2 ° C./min;

100 ° C.-200 ° C. heating rate 2 ° C./min;

200 ° C.-400 ° C. heating rate 4 ° C./min;

400 ° C.-900 ° C. heating rate 5 ° C./min; And

900 ° C.-holding time for 1 hour.

The total duration of the thermal reaction process was about 5 hours, after which the heating contents containing the crucible were cooled to 80 ° C. without external cooling. The contents of the crucible are placed in a leaching reactor equipped with a stir bar, and the washing of the reactants obtained here is carried out at 40 ° C. in a ratio of solid and liquid 1: 2. Washing was performed three times, wherein the pH of the wash water was up to pH = 4 at the final stage of washing. The obtained product was placed in a second reactor, in which a nano film of SiO ₂ was subjected to oxy-sulfur of rare earth elements and group IV elements using hydrolysis of a 1% solution of tetraethyloxysilane Si (OC ₂ H ₅ ) ₄ . -Deposited on the surface of synthetic particles of fluoride. The modified particles of the phosphor were then dried at a temperature of 120 ° C. for 2 hours. In this way, the photo-luminescent phosphor particles were very bright in ultraviolet light having a dark cream color and a wavelength λ = 365 nm. Particle measurements using a spectral analysis device (“Sensing”) and a laser-diffraction measurement device were used to adjust the parameters of the resulting photoluminescent phosphor.

The parameters of the obtained photo-luminescent phosphors are shown in Table 1 below.

In addition, the hydrolysis stability and the light stability of the obtained inorganic phosphor sample were tested. This measurement was performed in brine at a temperature of 80-100 ° C. under an ultraviolet lamp with λ = 365 nm and power density W = 5 W / cm ² for time acceleration. Changes in physical properties were minimal (less than 5%) over a 2-month exposure period.

It describes a modern light-conversion agricultural film for the tentative cultivation hotbed or greenhouse according to another embodiment of the present invention.

First, similar agricultural films were produced using powder technology for the addition of photoconversion phosphors. The film was produced as a one layer surface coating. Now that type of agricultural film and manufacturing method are outdated. Disadvantages of the known production methods of agricultural films are their thickness, the expense of polymers (polyethylene), and the luminescence brightness is irregular over the length of the film. In the present invention, the agricultural film and manufacturing technology has the following advantages:

The film is made of three layers. The inner layer is thicker and more durable, while the remaining two layers have unique functionality.

The film is produced using a two-step method, in which a concentrated photoconversion phosphor prepared in a master batch is produced using a screw die with three autofeeders. The film is taken out from the extruder and treated by flowing warm air, and adhered to the liquid polymer state above the glass transition temperature in the extruder and then solidified;

The multi-layer film is bonded under double-sided uniaxial tensile force, then intensively cooled and then wound on a reel. The 3-ply agricultural film has the following features:

A powder of light-converting phosphor is added to all three layers, and also the concentration of this material is higher in the outer layer and minimum in the inner layer;

-Light stabilizers based on quaternary amines of sebacic acid are added to the inner and outer layers of agricultural films, thus preventing the destruction of the film caused by intense ultraviolet irradiation of the sun in the presence of surrounding water vapor. do;

Some formulations are added to the inner layer of the agricultural film to hydrophilize the film surface to prevent the formation of large droplets of water on the film surface. Some stearate or derivatives thereof are used as such hydrophilic agents;

A special dye is added to the master batch at a concentration of less than 0.01% to produce an agricultural film of a certain color, for example reddish yellow.

Low-density polyethylene (only for extruders with ρ = 0.91 to 0.92 g / cm ³ ) is the main material for the proposed multilayer agricultural film.

In addition, another embodiment of the present invention may provide an agricultural film layer having a different thickness. That is, the thickness ratio of the inner / outer layer and the intermediate layer corresponds to 1: 2. This intermediate layer of agricultural film withstands all the power loads arising from mechanical deformation under hotbed conditions.

In addition to low-density polyethylene (LDPE), very strong polymers based on ethyl vinyl acetate or mixtures thereof and polyethylene (EVA) are added to the master batch for reinforcement of the inner layer. These compositions have been found to be very strong and inexpensive unless the EVA content in the LDPE is higher than 20% by mass. In this case, the three-layer film is produced in agricultural film of full thickness ranging from 100 μm (inner layer: 25 μm, outer layer: 25 μm, intermediate layer: 50 μm) to 120 μm (correspondingly 30 + 30 + 60 μm) as follows. Physical / mechanical measurement factors (Table 2).

When the agricultural film consists of three layers of transparent polymers of different thicknesses in very tight contact, such a high physical / mechanical factor of the three layer film is obtained. These three layers are based on LDPE and / or EVA and are packed at a concentration of 0.1 to 0.5% to reduce particles of the phosphor having the aforementioned chemical properties from the outer layer of the agricultural film to the inner layer, and also to the outer and middle layers of the film. A light stabilizer based on a quaternary amine of sebacic acid is added at a concentration of 0.2 to 0.6 mass%, and when some organic compound of stearic acid is added to the inner layer of the film, water droplets on the surface of the film And formation of pools of water streams is prevented.

Agricultural films are permanently transparent when these components are added, with no loss of water flow, with less than 70% loss of transparency.

Next, the emission spectrum of the said multilayer agricultural film was measured. Upon activation with ultraviolet light, the emission spectrum includes red light having a wavelength λ = 626 to 628 nm and dark red light having a wavelength λ = 708 to 710 nm. Photon efficiency of the phosphor was estimated to be 50 to 90%. The total content of UV-light in daylight is estimated to be approximately 6% and the additional intensity of red light effective for photosynthesis is 3 to 5%, which is sufficient to stimulate the photosynthetic response of warm-bed plants. It is worth noting that the proposed agricultural film has a luminescence brightness 2.5 to 4 times higher than known films.

Full-scale tests of the films were performed in different climates in Russia, China and Korea. Vegetables such as eggplant and red pepper were investigated. During the summer of 2005, a 37% increase in yield was achieved for the "Californian Large" bell peppers in Obbskoe, a greenhouse-grown farm in Novosibirsk, Russia. In addition, the first harvest of vegetables was 10 days faster than the control harvest to mature to a mass of 120 g.

Greenhouse cultivation in Busan, South Korea, increased eggplant yields by 56% for the period July 12-August 28, 2005. At the same time, the date of maturation of vegetables to an average mass of 460 g was reduced by 17 days. Application tests for the yield of "Livadia" species grapes were carried out in Dzyansu, China. The yield was increased by 40% compared to the control. The grapes were in very good condition, dark purple, sweet and very fleshy.

As described above, the red luminescent phosphor of the present invention, a method for preparing the same and a multi-layered light-converting agricultural film for a hotbed and a greenhouse,

New chemistry of phosphors with high spectral radiation intensity and high photon efficiency in converting short wavelength UV radiation into biologically active red light radiation to improve low-concentration and relatively small luminescence brightness of oxy-sulfide phosphors in greenhouse films Synthesis of the composition was made possible.

The present invention also makes it possible to provide an inorganic phosphor having an average particle size corresponding to the wavelength of emitted red or deep red light.

In another aspect, the present invention is to provide a greenhouse film filled with a small phosphor having a high chemical and mechanical factors to promote a photosynthetic reaction of the plant to provide an advantageous product that can increase the yield of agricultural products.

In addition, the above-mentioned example is only an example to demonstrate this invention. Therefore, it is obvious that the ordinary skilled in the art to which the present invention pertains uses the partial change with reference to the detailed description.

Claims (10)

In a red light reflection phosphor based on an oxy-sulfide of an rare earth element Sr and / or Hf and an activator, Phosphor characterized in that at least one selected from the group consisting of La-Y-Zr, Hf oxy-sulfur- fluoride having the following molecular formula. Molecular formula (La _{1 -xy- z} Y _x A _y Me _z ⁺⁴ O) ₂ S ₁ (F ^-1 ) _2z In the above formula, x is 0.001 to 0.2; y is 0.01 to 0.2; z is 0.001 to 0.005; Activator A from a number of elements is ∑ (TR ⁺³ = Eu, Sm, Gd, Tb) + (TR ⁺⁴ = Rr ⁺⁴ ); Re is a rare earth metal, Me ⁺⁴ is Zr ⁺⁴ and / or Hf ⁺⁴ . The method of claim 1, A phosphor whose main wavelength of phosphor reflection is in the wavelength range of lambda = 615 nm to 628 nm at an ion concentration of 0.050 <Eu / (Pr + Sm + Eu + Gd + Tb) ≤ 0.15. The method of claim 1, Phosphor in the ultraviolet wavelength range of λ = 320 nm to 410 nm, at an ion concentration of 0.06 <(Eu + Sm) / (Tr ^{+ 3} ) ≦ 0.095 in the molecular formula. The method of claim 1, The particles of the phosphor material are prepared as volume unit elements having an average diameter of 0.4 μm ≦ d ₅₀ ≦ 0.8 μm, and the maximum diameter of the particles is d = 6 to 8 μm. In the method of producing a phosphor according to claim 1, comprising chemical vapor deposition of a rare earth element and a hydroxide of a group IV element of the periodic table of the element and a thermal activation reaction of sulfide with fluoride, The deposition of the hydroxide is carried out at a temperature of 80 ° C. or less and a hydrogen ion concentration of pH> 2 from a solution selected from one or more selected from the group consisting of nitrate and acetate, and the reaction temperature with sulfide and fluoride is 200 to 900 ° C., d A process for producing a phosphor, characterized in that it occurs at an initial particle size of deposited hydroxide from ₅₀ = 0.050 μm to d ₅₀ = 0.10 μm. The method of claim 5, wherein The sulfide is used from a plurality of thioureas, thioacetoamides and ammonium thiocyanates having an oxidation value of -2 of the compound, and the fluoride is used from ammonium compounds from a plurality of NH ₄ HF ₂ or NH ₄ BF ₄ , The mass ratio between the hydroxide of the rare earth element as sulfide and fluoride is 0.5: 2: 1 to 2: 2: 1. A multi-layered light-converting agricultural film for hotbeds and greenhouses, comprising a polymer and filled with phosphors and light-stabilizing components, The film is composed of a multilayer film comprising a transparent polymer layer of different thicknesses in which at least one member is selected from the group consisting of a plurality of LDPEs and EVAs and in close contact with each other; The layers are filled with particles of the phosphor according to claim 1 which are gradually reduced from the outer layer to the inner layer to have a concentration of 0.1 to 0.5%; The outer and middle layers of the film allow the organic light stabilizing component based on the quaternary amine of sebacic acid to be contained in a concentration of 0.2 to 0.6 mass%, wherein an organic compound of stearic acid is additionally added to the inner layer of the film. A multi-layered light-converting agricultural film, which is added to prevent the formation of water droplets and water streams on the film surface. The method of claim 7, wherein The thickness of the polymer layer is a thickness of one layer of 20 to 50 ㎛, the outer layer, the intermediate layer and the inner layer is formed in a ratio of 1: 1: 1 to 1: 2: 1, the transparency of the film is characterized in that more than 80% Multilayer light-conversion agricultural film. The method of claim 7, wherein The film converts the sun's UV rays into radiation having a peak wavelength shift of 180 to 250 nm and photon efficiency of 50 to 90%, stimulating the photo-biological process of the green plant to yield a yield of 35 to 70%. Multi-layer light-conversion agricultural film, characterized in that it can be increased. The method of claim 7, wherein A multi-layered light-conversion agricultural film, characterized in that the ability to convert ultraviolet to orange-red and red radiation is proportional to the mass ratio between the phosphor added to each layer of the agricultural multilayer film and the quaternary amine of sebacic acid.