KR850001026B1 - Plastic film for agriculture - Google Patents

Abstract

Orange-colored transparent or semitransparent plastic film is used for heat insulation and to control light during cultivation. The film has a light-transmissibility lower than 50% in the region of 400 nm - 450 nm light-wavelengths, and has transmissibility of over 60% between 600 nm - 750 nm.

Description

Agricultural Plastic Film

1 is a visible light transmission spectra of films prepared in Examples 2-1, 2-2 and Reference Example 1 and used in Examples 4, 5, and 6.

The present invention relates to a transparent to translucent plastic film of orange color used in a vinyl house to give a better light environment to crops. The term 'better light environment' as used herein means a light environment in which the quality of the light as determined by the inventors of the present invention is promoted to promote the growth of crops, increase the yield, and in particular, significantly improve the cold resistance of crops.

In recent years, the demand for crops, especially horticultural crops, has increased rapidly beyond the seasonal limitations. In order to cope with this, there has been a large number of facility horticulture mainly in cultivating vinyl houses. However, compared to the cultivation of green house, cultivation of the plastic house requires relatively large expenses and manpower for its management (especially temperature control), which limits the cultivation area and production volume. It is putting a considerable economic burden on him. Therefore, efforts to solve this problem have been made in various scientific and technical aspects, and technological confrontation to improve house insulation through breeding studies for improving new varieties with high accuracy and cold resistance, improvement of coating materials and improvement of house installation method. Etc. are representative examples thereof. The present invention is also made as one such effort.

The inventors have conducted long-term photophysiological and biochemical basic studies on the amount of light on the physiology of higher plants, and the blue light in the wavelength range of 380 nm to 450 nm is removed or reduced in natural light (sunlight). It was confirmed that the full environment induces the constitution of higher plants, and completed the present invention in order to apply it extensively agriculturally. Thus, a light environment that can lead to remarkable constitutional improvements such as a strong growth of crops and a significant increase in yield at the time of vinyl house cultivation, and an improvement in cold resistance, which is the most desirable crop cultivation in the season, is extremely easy and economical according to the present invention. Will be provided.

Hereinafter, the results of some important basic studies conducted by the present inventors to help the understanding of the description of the invention are introduced.

Firstly, the findings indicate that mitochondria, one of the most important organelles of plant cell organelles, irreversibly lose their respiratory activity by irradiation with blue light.

On the other hand, solar visible light from which the blue light wavelength region was removed did not substantially inhibit the respiratory activity of mitochondria. In addition, irradiation of the mitochondrial dispersion under anoxic conditions had little effect on mitochondrial respiratory activity. This observation suggests that there is a photosenitizer in the mitochondria of higher plants that absorbs blue light and induces photosenitization, that is, photodynamic action, in which oxygen is involved. Photosenitization refers to a phenomenon in which a molecule absorbs light energy and then uses the light energy to cause a photochemical reaction with other compound molecules around it. Call it a Tiger. Photodynamic action refers to the case where oxygen is necessarily involved in the photochemical reaction induced by the photocatalytic acid, where oxygen is transformed into a species having strong oxidizing power, resulting in photooxidation.

The above results suggest that blue light is detrimental to the respiratory physiology of plants, and therefore the removal of blue light may help the plant to maintain a high level of respiratory activity. This is important given the fact that the respiratory activity of cells is directly related to the biological energy (ATP) generating activity.

Secondly, the results of this study confirmed that some of the coenzymes of hemo-groups and flavins of respiratory proteins bound to mitochondrial membranes have functions of photocatalytic activity.

Cytochrome aa ₃ to have a power group (cytochrome C oxidase) has been a loss of the enzymatic activity at the time of blue light irradiation under the presence of oxygen severely. In the case of irradiation of solar visible light in which only blue light was removed, the inhibition of enzymatic activity did not occur substantially even in the presence of oxygen, and no effect of blue light was observed under anoxic conditions. This observation suggests that the cytochrome aa ₃ has a strong light absorption band in the blue light region of 400 nm-450 nm by its force group, demonstrating that the force group is a photoresonator that causes photodynamic action. will be.

Another important enzyme in mitochondria, succinate dehydrogenase, was similarly inhibited by blue light irradiation with or without oxygen. At the time of irradiation of solar visible light from which blue light was removed, the degree of the activity inhibition was remarkably low. This suggests that pravinin of rotinate dehydronase is not a photocatalytic agent that causes photodynamic action, but it is producing a photocatalytic system that does not involve oxygen. In other words, the degree of loss of activity in the blue light absorbed by the prabin is much higher, suggesting that it is a photoinitiator that induces the oxidative destruction of amino acid residues at the site of enzymatic activity by photoreduction.

These findings suggest that flavin proteins and heme proteins, which are generally known to be irrelevant to photocation, actually suffer from activity inhibition by photocation, which in turn inhibits important physiological functions of cells. Although it is significant to confirm the fact, it is confirmed that some cytochrome and prabin-based proteins present in cells that absorb blue light may be sensitive to photodamage caused by blue light. There is a big meaning.

On the other hand, the free state of prabin and porphyrins prior to their incorporation into proteins is a well-known, very powerful blue photonsitizer, so even if they are present in very small amounts in cells, their photophysiological effects cannot be ignored. In the active young leaves, their content will be significantly higher than in mature leaves, so the photooxidation of free-formed cellular components by prabin and porphyrin in free state may be greater than expected.

The third study suggests that leaf foliar cultivated under a light-reduced light environment has a relatively high degree of unsaturation compared to leaf cells of a crop (control) grown under natural light (ie white light) without blue light. It contains phospholipids.

Aging of cells often involves a decrease in the degree of unsaturation by oxidative destruction of cell membrane lipids. Organisms contain antioxidants in their cells to prevent this oxidation, and tocopherols are a good example. However, the fact that the unsaturation of the cell biofilm is reduced is due to the fact that the unsaturated bond of the lipid fatty acid component is oxidatively destroyed. Therefore, the presence of blue light in visible light affects the membrane lipid unsaturation, which indicates that blue light generates a large amount of highly oxidizing chemical species to overcome the limitations of cell-specific antioxidants. It may be interpreted that it is due to causing a photodynamic action. However, it is unreasonable to believe that oxidizing species acted only on lipids in biological membranes. In addition to lipids, there are several substances that can be subjected to oxidative destruction such as proteins, nucleic acids and carbohydrates, and their destruction will result in damage to cellular functions maintained by the organic interrelationship of these biological materials.

The fact that the unsaturation of biofilms is high is of great significance in relation to the cold resistance of crops. This is because the phase transition temperature of the biofilm having high unsaturation is lower than the phase transition temperature of the biofilm having low unsaturation.

Here, the phase change of the biofilm refers to an abnormal solid gel phase when the biofilm having a high liquidity liquid phase required to maintain normal physiological activity is brought to a low temperature below a certain temperature. It means the phenomenon, and the temperature at which the phase transition of the membrane occurs is called the phase transition temperature.

Although the manifestation of cold thaw is expressed as a result of complex biochemical reactions, it is a general view that the cold process is regarded as the phase transition of the cell membrane, and the phase transition temperature of the membrane is regarded as the cold thaw temperature of the plant. According to a study conducted by the present inventors to investigate the correlation between the degree of cold resistance of crops and the phase transition temperature of biofilm, especially mitochondrial membrane, and the unsaturation of membrane lipid, especially phospholipid, various varieties of the same crops There was an inverse correlation between the phase transition temperatures and a positive correlation between the degree of cold resistance and phospholipid unsaturation. Therefore, the increase in the unsaturation of the cell biofilm lipids of the crops by the light environment from which blue light is removed results in the improvement of the cold resistance of the crops.

Fourthly, the results of the research are that the leaves of crops grown in a light environment with blue light removed significantly increase the content of photosynthetic pigments in a unit weight of leaves compared to crops grown in a white light environment. The increase in carotenoids was relatively higher than that of chlorophyll.

The activity of carbon assimilation caused by plants collecting light energy will be primarily dominated by the light energy collection capacity, and the light energy collection capacity will be improved by increasing the photosynthetic pigment content. Therefore, increasing the photosynthetic pigment content means efficient photosynthesis. The high photosynthetic efficiency will contribute to overcoming the undesirable effects that the removal of blue light may have on photosynthesis, namely the degradation of carbon assimilation due to light reduction.

The fact that the relative content of carotenoids has been increased significantly, on the other hand, is important because the carotenoids have more important functions not only as auxiliary photosynthetic pigments but also as photoprotectors for protecting cells, especially chloroplasts, from photodamage. It is implicated. Chlorophylls must be absorbed essentially for photosynthesis, but ironically, the absorbed light itself is partly used to produce oxidizing species (especially single excited states) that cause photodynamic action, or photooxidation. do. This phenomenon occurs well when plants absorb more than the amount of light needed for photosynthesis, and the whitening of plants under high intensity visible light is a representative example. Carotenoids have a function of removing oxygen in a single excited state and converting them into oxygen in a triple (or bottom) state without oxidation, thus protecting plant cell components from photooxidation. Thus, the increase in the content of carotenoids, whether it is a photomorphogenetic response following blue light removal or a result of photodynamic action, cannot be interpreted at this time, but as a result, the photoprotective function of the plant itself is consequent. There is no doubt that it means improvement.

When comprehensively evaluating the results of the four basic studies described above, the desirable effect of the blue light-free light environment on crops is to protect various cellular components, including enzymes from photooxidation, especially photooxidation. It can be concluded that light damage to respiratory activity can be prevented, photosynthetic ability can be improved, and cold resistance can be improved. In other words, it can be said that it has a positive change in crop physiology at sub-cellular level, leading to overall constitution improvement.

However, it should be reserved to conclude that the effect of blue light removal appears to be the same for all kinds of higher plants. This is because the photophysiological phenomena of plants, which can be roughly classified as photosynthesis, light morphology, and photodamage, also have some differences, although they have significant commonalities in all plants. For example, from the standpoint of photosynthesis, visible light in almost all wavelength ranges can be used for photosynthesis, so the removal of blue light may cause a lack of light, especially in plants that require a large amount of light. However, in plants with small light demands, the photosynthesis may be sufficient by the visible light of the red light region, and the removal of the blue light may be beneficial in terms of minimizing the optical damage of the plant. Therefore, assuming that the formation of photoforms in higher plants is substantially determined by the visible light in the longer wavelength range, determining whether the removal of blue light is beneficial or detrimental to plant growth depends on the positive effects of photosynthesis by blue light. Which of the negative effects of light damage depends on the predominance of the plant. In the case of plants with strong negative effects, the light environment from which blue light is removed must have a beneficial effect on plant growth.

In general, photodamage suffered by plants is not detected because most of them are not manifested as external pathology except in severe cases. In addition, even if there were any changes in appearance, such altered physical and physiological changes themselves are a natural thing accepted by people's long experiences and are not likely to be seen as a result of light damage. However, it is not manifested as a particularly noteworthy pathological symptom, because the extent to which photodamage actually falls within the range of the plant's ability to heal, and the energy and substances that the plant must consume for its healing must have grown without it. Would have been used.

The effect of blue light removal may be different depending on the cultivation area and season, even for the same plant. For example, in areas and seasons where the average amount of sunshine is fairly small, many types of plants will be somewhat deprived, in which case the removal of blue light may cause fatal depletion. Moreover, when the amount of natural light is small, the degree of light damage will also be relatively low, so attempts to minimize light damage by eliminating blue light may be meaningless.

Therefore, the results of the photophysiological basic research conducted by the present inventors, although it is very encouraging enough to solidify the belief that innovation of crop cultivation technology through the light environment can be achieved, the development of agricultural applications For this purpose, the feasibility study through systematic experimental demonstration of systematic cultivation should be a priority.

In order to cultivate crops in a light-controlled light environment using only sunlight as the only light source, it is necessary to use a filter device (or facility) that can block or reduce light in a certain exaggerated region. The first consideration is a kind of optical filter made of glass. If a suitable coloring material is added to the glass to impart the function of the optical filter, it will be very good as a filter device that can control the light quality of transmitted light. However, the use of glass products is accompanied by economic burdens that cannot be used for large-scale facility cultivation at the farm level. The second material that can be considered is a rigid plastic sheet such as celluloid or polymethacrylate. These resins are suitable for making filters as they can find dyes that are colored relatively easily. In general, however, the organic dyes of orange color are not high in light stability, and even though the addition of an appropriate light stabilizer improves the stability, the long-term stability is sufficient to meet the facility investment cost for using the resin sheet (hence the period of use). Has a defect that cannot be guaranteed.

Given these circumstances, it is economical to use a thin plastic film called ching binniru, which is used in general cultivation farms for short periods of one month and about one year, and then discarded due to the limitation of its lifespan. In terms of aspect, I think it is most desirable in reality. Of course, for this purpose, first of all, the discovery of a dye that has been proved appropriate in general physicochemical properties, such as affinity with the resin composition, light absorbing properties, light and heat stability, should be prioritized.

In general, however, it is not easy to find a commercialized orange dye that binds to a resin such as polyvinyl chloride, which is a raw material for manufacturing a film for a vinyl house, and has desirable physicochemical properties. Moreover, this is especially true when high stability is required. However, in the case of a vinyl house film, it is not necessary to have a very high light stability because it has only a light capacity for a certain period of time depending on the life of the film itself or even shorter, depending on the method of crop cultivation. If reasonable, the photostability problem of the dye will be solved by the addition of a suitable light stabilizer. In view of this, the inventors of the present invention have produced a soft coating for house (so-called beanie) having a luminous ability to blue light, and have completed the present invention through empirical experiments on the effect of packaging cultivation.

The present invention is characterized as having a plastic film as shown in the first table as a plastic film to be used as a coating material for the vinyl house when crop cultivation.

[Table 1]

As long as the present invention has the light transmitting properties as shown in the first table, the configuration of the plastic film composition is not a problem. Preferably, the photochemical reaction of one or more types of polyolefin-based resins and mixtures of one or more types of organic dyes with a strong physical or chemical affinity with the resin is shown around 450 nm and the first light absorption band is around 450 nm. It will be good when one or more types of light stabilizers for inhibiting these are basic constituents of the resin composition. In particular, the addition of the light stabilizer is preferably added in order to extend the life of the color in the case of the film to be used for a relatively long time or the film to be used in the summer when the sunlight is strong, and the addition of the ultraviolet absorber also blocks the ultraviolet rays. It would be better to add it as an auxiliary light stabilizer.

However, depending on the method of cultivation, for example, in the case of seedling nursery, only a resin and a dye may be sufficient to form a film used for a relatively short period of time, and the use of other additives such as a light stabilizer may have a disadvantage in terms of product price. Will give.

In addition to dyes, ultraviolet absorbers, and light stabilizers, various additives commonly used in resins, such as thermal antioxidants, invincible agents, antistatic agents, and fibrous reinforcing agents, may be added to the plastic composition of the present invention.

The concentration of dyes and other additives is a commercially available resin which employs a so-called master batch method and manufactures a master batch containing a high concentration of dyes and other additives, which is adapted to a predetermined concentration range during film molding. It may be good to adjust by mixing with the raw material, but is not limited thereto.

The composition ratio of the most important dye in the composition of the present invention is determined according to the light absorbency of the selected dye, light and thermal stability, the efficacy of the added light stabilizer, the film usage period, the cultivation method and the type of crop, etc. Adjustments are made within the range to maintain the optical properties shown in the table.

The present invention is produced by one or more of the methods commonly used in the plastics industry, including extrusion molding as a blown film or a flat film. The thickness of the film is in the range of 0.01 mm-0.15 mm and preferably in the range of 0.018 mm-0.1 mm for agricultural purposes.

As mentioned above, in the selection of the most important dyes in the composition of the present invention, the most important point is the light absorption property and the affinity with the resin. A dye that does not have a sufficiently high affinity with the resin component can maintain a physically simple dispersion state in the resin matrix but severely degrades the transparency of the film and does not give the desired optical properties despite the similar color. In particular, the problem becomes more serious when producing a very transparent film having a light orange appearance and having a very deep orange color in appearance, instead of showing a high light transmittance in the long wavelength region of 500 nm or more.

As an example, color indicator 26080 (CI 26-8- or CI Disperse Orange 13), which is one of the azo dyes used in the embodiment of the present invention, has ideal light absorption properties but shows little affinity with nonpolar hydrocarbon media. The transparency of the film was poor when added during film molding.

However, with the resin containing an acetate group, for example, ethylene-vinylacetate copolymer, the dye showed a high affinity and thus could be prepared as an orange film having good transparency. On the other hand, even in the case of a polyethylene-based film, the dye showed excellent transparency when prepared by adding an ethylene vinyl acetate copolymer such that the vinyl acetate content was 2% by weight to 10% by weight.

The light stabilizer added to maintain the color of the plastic film for a long time is preferably selected in consideration of the mechanism of the photochemical reaction of the dye used.

For example, when photochemical reactions occur by photooxidation mechanisms, antioxidants and peroxide destroyers should be selected, and when it follows a radical mechanism, a radical scavenger should be chosen. However, considering the fact that the photochemical reaction of a compound must be the first process of absorbing light energy and transferring it to an electronically activated state, a material having an ability to extract energy from the compound in the activated state, that is, an energy quencher ( It is also appropriate to use energy quencher. This is especially true when dyes are used in which the mechanism of photochemical reaction is unknown.

The light stabilizer of the dye is preferably used in combination with a light stabilizer for resin, which is commonly used to extend the life of the molded plastic film as far as possible and the physical properties are known and the influence on the film properties is known. On the other hand, in order to maintain the function as a light stabilizer in the long-term resin matrix, a high molecular compound having low transferability, extractability and low volatility is recommended.

UV absorbers are beneficial not only for most crops, but also for blocking harmful UV rays, except for extremely low amounts of natural light.However, it improves the stability of the resin and absorbs all organic dyes. It is recommended to add at the time of plastic film molding because it shows the effect of improving the light stability of dyes by preventing ultraviolet rays.

Hereinafter, the manufacturing process of the present invention, the characteristics thereof, and the cultivation of the crops using the same and the effects thereof will be described in detail.

Example 1

Preparation of Master Batches Containing Dyes

An embodiment of a method for producing a masterbatch using an ethylene vinyl-acetate copolymer or a mixture of polyethylene and ethylene-vinylacetate copolymer and for use in forming colored plastic film. To a pellet of a commercially available ethylene-vinylacetate copolymer (vinyl acetate content of 28% by weight) is added three times or more ethyl acetate in volume ratio, which is then heated to 55 ° C. for 1 hour in a water bath and then heated at 60 ° C. for 1.5 hours. . At this time, stir the contents vigorously for about 20 minutes to help even heating. The volume of pellets that absorbed a large amount of ethyl acetate is about twice as large as the original, at which time the remaining ethyl acetate is poured out and a dry mixture of a predetermined amount of dye or light stabilizer and UV absorber before the pellet temperature drops as much as possible. Add to the pellet and mix quickly.

Most dyes, light stabilizers, and UV absorbers are sucked into the pellets to obtain orange, red or dark brown pellets, depending on the dye content, which is sufficiently air-dried until the smell of ethyl acetate cannot be detected using hot air. Got a batch.

The dye used in this example is color number 26080, and the light stabilizer is Chimasorb 944 from Shivagai Company, and the UV absorber is Chimasorb 81 from the company. These powdery additives were mixed well beforehand to intake ethylene acetate and added to the blown pellets to have an even mixing.

[Examples 2-1 and 2-2]

The masterbatch prepared in Example 1 and low density polyethylene (specific gravity 0.919) were melt-trained at 180 ° C. using an extruder at the compounding ratio as shown in Table 2, and then molded into a blown film (nominal thickness: 0.05 mm).

The masterbatch used in this example was prepared by adding 10% by weight of the dye specified in Example 1, 3% by weight of the light stabilizer and 3% by weight of the ultraviolet absorber.

The physical and optical properties of the produced film were evaluated and the results are shown in the second table. The tensile strength, elongation and tear strength were passed the Korean Industrial Standards required for 0.05mm-thick low density polyethylene films, and when evaluated as an external observation, the transparency of the film and the spreading of the dye were good. Properties also fall within the desired range (see Table 1). A curve showing the light transmittance for each wavelength of the film is shown in FIG. 1 of the accompanying drawings.

[Table 2]

Example 3

It is the Example which investigated the light stability of the color of the film manufactured in Examples 2-1 and 2-2. For 4 months in winter, from November 5, 1982 to March 5, 1983, the film was exposed to open field under natural light in Suwon, Gyeonggi-do. Irradiation method measures the light absorption at 447 nm, the maximum absorption wavelength of the film, every five days using a spectrophotometer, and the half-life is estimated by semilogism. Calculated. On the other hand, the period of maintaining the optical properties as shown in the first table (hereinafter referred to as the usable time) was investigated by obtaining the light transmission spectrum of the film over the full-wavelength field every 5 days using a spectrophotometer.

The above results are shown in Table 3.

[Table 3]

(1) Example which produced the film used for irradiation

(2) Results obtained under winter weather conditions from 1982 to 1983.

Reference Example 1

A conventional colorless transparent film was prepared in the same manner as in Example 2-1 except for using the ethylene-vinylacetate copolymer instead of the masterbatch used in Example 2-1.

The film prepared in Reference Example 1 was used as a control for comparison purposes in all of the following Examples, which investigated the effect of the film produced in Examples 2-1 and 2-2 on crop growth.

A curve showing the light transmittance for each wavelength of the film is shown in FIG. 1 of the accompanying drawings.

Example 4

When cultivating crops in a plastic house installed with the films prepared in Examples 2-1 and 2-2, the effects of the physiology of the crop on photosynthetic capacity and respiration physiology, especially at low temperatures. In addition, the crop was grown by installing a vinyl house with the film prepared in Reference 1 and used as a comparative example.

Three plastic houses of 10 pyeong size were installed, and Example 2-1, Example 2-2 and Reference Example 1 were also coated with the prepared films. Lettuce (Ttukseom), pumpkin (Bulam House), tomato (Gwanggwang), cucumber (New Black Pearl), and red pepper (Hanbyeol) were grown as follows. During the cultivation period, the temperature of each vinyl house was kept equal to each other.

Example 4-1

This is an example in which the increase in the photosynthetic pigment content contained in crop leaves. Quantification of pigments was carried out in accordance with existing methods of extracting pigments using several organic solvents and irradiating light absorption using spectrophotometers, for example, widely used in academia and readily available in many literatures. Samples were taken from all four representative leaves immediately before flowering.

Table 4 shows the pigment content contained in 1 gr of leaves.

[Table 4]

(1) Coating material Examples and reference examples for producing the used film.

Example 4-2

It is the Example which investigated the increase rate of the photosynthetic light reaction rate of chloroplast.

All leaves were taken from four representative branches of the flowering branch and chloroplasts were separated therefrom. Briefly, how to separate the clean leaves by grinding the leaves for 5 seconds (using Waring blender, adding grinding medium) to a thin cloth (using a cloth) and then centrifuging (5 minutes at 4000g) to discard the supernatant and pellet. ) Is dispersed in a buffer to obtain a dispersion solution of chloroplasts.

The photosynthetic light reaction rate of chloroplasts was measured using the famous Hill reaction. That is, the chloroplast was taken so that the chlorophyll content was 60 µg, and added to the reaction solution of 6 ml of final volume containing 0.33 mM K ₃ Fe (CN) ₆ . After measuring absorbance at 420 nm, red light with a wavelength of 600 nm or more is irradiated for 60 seconds. The absorbance was measured again at 420 nm to obtain an increase in absorbance. From the difference in absorbance at 420 nm, the reduction amount of Fe (CN) ₆ ^-3 is converted to determine the light reaction rate.

The photosynthetic light reaction rate by the Hill reaction was measured at 25 ℃ and 5 ℃, respectively. The results are summarized in Table 5.

[Table 5]

(1) Examples and reference examples for producing films used as coating materials.

(2) Hill reaction rate is the conversion of chloroplast contained in 1gr of crop leaves as μole of Fe (CN) ₆ ^{-3 which} is reduced through light reaction for 1 hour.

Example 4-3

This is an example in which the temperature at which mitochondrial respiratory activity is inhibited, that is, the respiratory depression temperature (or cold sea temperature) is lowered. Mitochondria of cells were isolated from the harvested crop leaves in the same manner as in Example 4-2 and Example 4-3. Separation of mitochondria was applied to the differential centrifugation widely used in academia. The respiratory activity of the isolated mitochondria was measured by detecting the rate of decrease of the amount of oxygen dissolved in the mitochondrial dispersion with a dropwise mercury polyograph and recording it on the time axis with a recorder. Respiratory activity was measured at every temperature while increasing the temperature by 1 ° C from 5 ° C to 25 ° C. The Arrhenius plot of the respiratory activity measured at each temperature shows two branch lines with discontinuities, the temperature of which is the respiratory depression.

Table 6 shows the respiratory depression temperature of the crop measured by the same method as described above.

[Table 6]

(1) Example 2-1, 2-2 and Reference Example 1 which produced the film used as a coating material

As described above, through the results of Example 4 arranged in Tables 4, 5, and 6, the plastic film having the optical properties as in Table 1 was applied to the crop growth where the present inventors revealed basic research. It has been found that it makes it very easy to take advantage of the beneficial light environment, in other words, the physiological properties of crops in the most unfavorable direction (ie, growth, yield and cold resistance).

Example 5

This is an example of the cold resistance test of the crops.

Cultivation of the crop was pot cultivated in the plastic house used in Example 4.

Rice was sown on April 26, 1983, and the cold resistance of seedlings was planted on May 20, and red pepper was sown on July 12, 1983. In the investigation method, the crops were placed in pots in a temperature-controlled chamber at a constant low temperature, left for 24 hours, then transferred to a plastic house, and then observed for freezing for 48 hours. The published rice variety is 'Taebaek' and the pepper variety is 'Hanbyeol'.

The results are shown in Table 7.

[Table 7]

(1) The films used were the films produced in Example 2-2 and Reference Example 1, respectively.

Example 6

Using a film prepared in Example 2, a plastic house of about 60 pyeong was installed, and crops were cultivated in the same manner as in Example 4, and the yield was investigated.

The crops were cultivated in an area of about 20 pyeong each, and the cultivation areas are Gwangju, Jeonnam and Suwon, Gyeonggi-do. The yield of each crop is shown in Table 8.

[Table 8]

(1) The lettuce is the lateral weight of pumpkin, tomato, cucumber is the fruit and vegetable weight, the pepper is the total weight of the ripened fruit.

(2) The films produced in Examples 2-1 and 2-2 and Reference Example 1 used as coating materials.

Claims (2)

Transparent or semi-transparent plastic film with orange color, used for thermal insulation and light environment control. The film according to claim 1, wherein the optical film has a light transmittance of 50% or less in the light wavelength region of 400 nm to 450 nm and a light transmittance of 60% or more in the light wavelength region of 600 nm to 750 nm.

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