Light-splitting spectrum greenhouse film and preparation method thereof

Abstract

The invention relates to a light-splitting spectrum greenhouse film which comprises an inner film, a middle film and an outer film, wherein the master batch of the outer film comprises 2.8-3.4 parts of optical stabilizer, 0.8-1.1 part sof antioxidant, 0.8-1.2 parts of polyethylene wax, 0.8-1.2 parts of light-splitting assistant and 48-57 parts of polyethylene-vinyl acetate copolymer; the light-splitting assistant is the mixture of La<3+>, Y<3+> and Gd3<+>; the ratio by weight of the rare earth ions La<3+>, Y<3+> and Gd<3+> is (4-5):(8-9):(5-6); the ingredients comprise EVA (ethylene-vinyl acetate copolymer), LDPE (low-density polyethylene) and LLDPE (linear low density polyethylene); the ratio of parts by weight of the EVA, LDPE and LLDPE of the outer film and the master batch is (23-27):(23-27):(73-77):(11-17); the Eu<3+> ions in the rare earth assistant are partly displaced by non-fluorescent rare ions La<3+>, Y<3+> and Gd<3+> to form a heteronuclear multinuclear coordination compound, so as to strengthen the luminous intensity and overcome acute peaks; the half-width of the emission spectrum is 70nm; the excitation wavelength of the light-splitting spectrum greenhouse film is 290-390nm, the maximum wavelength is 332nm, and the emission spectrum is between 580-660nm; ultraviolet lights in solar radiation can be absorbed and transformed into red orange lights with large emission brightness and good colour purity; and the light conversion rate reaches 98%.

Description

technical field [0001] The invention relates to a greenhouse film, in particular to a spectroscopic greenhouse film for agricultural vegetable greenhouses and a preparation method thereof, belonging to the technical field of chemical industry. Background technique [0002] When the chlorophyll of plants performs photosynthesis, it mainly relies on the blue-violet light with a wavelength of 400-480nm and the red-orange light with a wavelength of 600-700nm. Therefore, the light in these two intervals is beneficial to the photosynthesis of plants; Basically not absorbed by it. At present, the greenhouse mainly relies on the greenhouse film to increase the temperature inside the greenhouse to promote the growth of crops. The ordinary greenhouse film only transmits the attenuated sunlight into the greenhouse, which cannot satisfy the growth of plants, the incidence of diseases and insect pests increases, and the quality of agricultural products is low. Only when the main peak of...

AI Technical Summary

Problems solved by technology

Although the types and light conversion principles of these light conversion agricultural films are not the same, they all have the ability to absorb ultraviolet light harmful to plants in sunlight or green light useless to plant photosynthesis, and convert it to emit light that is beneficial to crop growth. Red-orange light and blue-violet light can increase the effective light in the shed, accelerate its photosynthesis, promote its growth and early maturity, improve quality and increase production and income. The above light conversion agents generally use Eu 3+ Compounds are used as rare earth additives, so although Eu 3+ The light conversion agent has high light conversion efficiency, and most of the emitted light is Eu 3+ The sharp peak, so the half-width of the emission spectrum is relatively narrow, Eu 3+ The half-width of the emission spectrum is 4nm, and the matching with the photosynthesis spectrum of crops is poor; the light conversion decay period of the agricultural light conversion film is short, the anti-ultraviolet aging ability of the light conversion agent is very weak, and the light conversion performance of the organic light conversion agent during long-term use There is a serious decline. After one year of outdoor exposure, the fluorescence emission intensity can only reach 10-30% of the initial fluorescence emission intensity, and the attenuation period is only a few months when it coexists with hydroxyl polar groups.