JPH03262419A - Agricultural plastic film - Google Patents

Abstract

PURPOSE:To obtain the subject film, composed of a polyolefinic resin, etc., having a specific difference in reflectance of visible light between the front and back surfaces of a film and molded by coextrusion or bonding processing of two or more layers and capable of utilizing two kinds of reflected light or transmitted light with one film. CONSTITUTION:The objective film having the first layer prepared by, e.g. mixing 0.4-1.5g/m<2> aluminum particles therein and regulating the reflectance of visible light to 40-55% and the second layer obtained by forming a vacuum deposition layer of aluminum, suppressing the reflection within the ultraviolet ray region and regulating the reflectance of visible light to 50-95% with >=40% reflectance of the visible light, >=80% light shielding ratio, >=6% difference in reflectance of the visible light between the front and back surfaces of the film and >=30% difference in reflectance within the ultraviolet ray region of 290-390nm between the front and back surfaces of the film.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an agricultural plastic film, and more particularly, to an agricultural plastic film that can utilize reflected or transmitted light with different amounts of light and light quality by separating the front and back sides. ] An agricultural plastic film with at least two layers, the first layer containing 0.4 to 1.5 g of aluminum particles.
The reflectance of visible light is set to 40 to 55% by mixing, whereas the second layer is formed with a vapor-deposited layer of aluminum or a reflective material is mixed to set the reflectance of visible light to 50 to 95%. By controlling the strength of the amount of reflected light on the front and back sides, an appropriate amount of reflected light can be ensured, and the temperature suppression effect on the back side can be used depending on the front and back sides. K. Prior Art Agricultural reflective films intended to reflect sunlight are used in the cultivation of fruits such as peaches, apples, and cherries. For example, if you want to take peaches as an example, if they ripen early, have bad weather, or if you want to improve their coloring,
An aluminum vapor-deposited film with a reflectance of 80% or more is used, which allows fruit coloring to proceed efficiently and to produce fruit with uniform appearance and quality. On the other hand, when cultivating late varieties, in climates with high sunlight, or when harvesting in midsummer, it is better to use a film containing aluminum particles with 50% reflection, which will prevent the fruit from sunburn, high reflectance, and high temperatures. This results in less deformation, coloring that matches the fullness of the sugar content in the fruit, and improved quality. Problems to be Solved by the Invention Therefore, in order to obtain a cultivation environment in which high-quality fruits can be harvested, it is necessary to prepare at least two types of mulch films that have different reflectances from each other. Preparing two types of films in this way not only increases costs but also requires space to store unused films. Also, depending on the weather conditions, there are years when only one type of film is used, which is unreasonable and not a good idea. The present invention has been made in view of these problems, and an object of the present invention is to provide an agricultural plastic film that can be used on the front and back sides, and can utilize reflected light or transmitted light with different amounts of light and light quality. 1.
The object of the present invention is to provide a film in which two types of reflected light or transmitted light can be used by using two films.

[Means to solve the problem]

The present invention has a visible light reflectance of 40% or more, a light tracing rate of 80% or more, a difference in visible light reflectance between the front surface and the back surface of the film of 6% or more, and a UV range of 290 to 390 n-. A multilayer agricultural plastic film made of polyolefin resin or vinyl chloride resin formed by coextrusion or adhesive processing of two or more layers in which the difference in reflectance between the front and back sides of the film is 30% or more. , a first layer containing 0.4 to 1.5 g/m' of aluminum particles with a visible light reflectance of 40 to 55%, and a vapor-deposited layer of aluminum to suppress reflection in the ultraviolet region and reflect visible light. a second layer with a visible light reflectance of 50 to 95%, or a first layer with a visible light reflectance of 40 to 55% by mixing aluminum particles at 0.4 to 1.5 g/m', and an oxidized layer. Which of titanium, talc, magnesium oxide, or lead oxide is 1
Species or two or more reflective materials at 5.0 to 40.0 CI/
m2 is mixed to suppress the reflection in the ultraviolet region and reduce the reflectance of visible light to 5.
and a second layer having a concentration of 0 to 95%.

[Effect]

Therefore, it is possible to secure an appropriate amount of reflected light by selectively using the strength of the amount of reflected light on the front and back sides, or it is possible to secure an appropriate temperature for cultivation by selectively using the temperature suppressing effect on the back side of the light-receiving film, which is inversely proportional to the reflectance. . Example K] As the base resin raw material, high pressure polyethylene, OP
P, PET, etc. are used, and the thickness is 20 to 100 μm. Then, aluminum particles are mixed, aluminum is vapor-deposited, or titanium oxide is mixed. The temperature rise on the light-receiving back surface in such a case is as shown in FIG. In the present invention, a material having a visible light reflectance of 40% or more and a continuous light rate of 80% or more is used. In order to meet the above conditions, aluminum particles are mixed into one of the front and back layers, and
In a film containing titanium oxide in other layers, as shown in Figure 13, the layer containing titanium oxide has a
The reflectance from 90 to 390 ns is as low as 10 to 15%, and the aluminum particle mixed layer has a reflectance from 290 to 390 n-s of 50% or more. On the other hand, as shown in FIG. 14, winged insects are easily affected by ultraviolet wavelengths centered around 340 nm, and a film that divides the ultraviolet wavelength range by 50% or more has a high repellent effect. Therefore, when a film consisting of a reflective layer containing aluminum particles and a reflective layer containing titanium oxide on the front and back surfaces is used in combination with the aluminum layer as a light-receiving surface, it will be able to repel winged insects and at the same time have the effect of suppressing soil temperature. . On the other hand, when a titanium oxide layer is used as a light-receiving surface, the effect of suppressing soil temperature is high, but the effect of repelling winged insects is reduced. As the structure of the agricultural plastic film according to the present invention, various configurations shown in FIGS. 1 to 5 are possible. The first structure is such that the first layer on the front side and the 211th layer on the back side are joined via an intermediate contact @W13. Second
The structure shown in the figure is a multilayer structure in which the first layer, the second layer, and the transparent film layer 14 are coextruded. In FIG. 3, the transparent film layer 14 is located on the second layer side, and is molded by coextrusion as in the case of FIG. 2. The structure shown in FIG. 4 does not include the transparent film 1114, and the first layer and the second layer are formed by coextrusion. In the structure shown in FIG. 5, an adhesive layer 13 is interposed between the first layer and the second layer, and a transparent film layer 14 is arranged on each surface of both stools. Next, a specific example of the combination of the first layer and the 211th layer will be explained. In the first example, the outer layer is made of a film on which aluminum is vapor-deposited, and its reflectance is 80-90%. Also, the inner layer is 0.4~
It is composed of a layer mixed with aluminum particles of 1.3 CI/m2, and its reflectance is 40 to 55%. In the film of the second example, the outer layer is composed of a layer containing titanium oxide, and titanium oxide of 5.0 to 40°0CI/12 is mixed, and the reflectance is 50 to 85%. ing. In addition, the inner layer is mixed with aluminum particles of 0°4~15C1/m', and its reflectance is 40
~55% clay. Therefore, with a film having different reflectances on the front and back sides, it is possible to ensure an appropriate amount of reflected light and to prevent problems caused by an increase in reflected light by appropriately using the strength of the amount of reflected light on the front and back sides. Figures 6 and 7 show peaches, melons,
This shows how to use the intensity of reflected light in the cultivation of eggplants etc., as shown in FIG. As shown in J, the intensity of the reflected light changes depending on whether the second layer 12 is a reflective surface or not.
It becomes possible to ensure an appropriate amount of reflected light. In addition, with a film having different reflectance on the front and back sides, it is possible to ensure an appropriate temperature for cultivation by selectively using the temperature suppressing effect on the back side of the light-receiving film, which is inversely proportional to the reflectance. In other words, as shown in Figure M8, there are cases where the agricultural film is coated with the first layer on the outside, and cases where cultivated soil is coated with the second layer 12 as the outside as shown in Figure 9. , the temperature of the assembly surface will be different, making it possible to ensure an appropriate temperature. The use of such a film is suitable for water cultivation and the cultivation of chrysanthemums, strawberries, and turquoise. In addition, as shown in Figures 10 and 11, when used for growing rice seedlings, by switching the front and back sides of the seedlings depending on the growing situation, the appropriate temperature can be obtained depending on the budding stage and greening stage. becomes possible. Furthermore, by using such a film, it is possible to utilize the UV reflectance of the front and back surfaces, and to use different films according to the two crops or cultivation period, improving the quality of vegetable mulch cultivation. It will be possible to improve the yield and stabilize the harvest. Next, test results of actual usage examples will be explained. The continuous light rate is 85-90% and the number of reflective surfaces mixed with aluminum particles is 4.
A test was conducted by applying a film having a reflectance of 5 to 50% and a titanium oxide-containing reflective surface of 60 to 75% for raising paddy rice seedlings. The aluminum side was used facing up until germination, the titanium oxide side was turned up after germination, and the other side was used after greening, under the temperature conditions shown in Table 1. As a result, seedlings could be raised stably in terms of budding and greening, and cultivation could be done with just one irrigation operation when replacing the reflective surface, saving labor. Since this film can be used in the same location, there is no need for rough transportation or the preparation of two types of film, and by making the two types of films with different performance 1/2 the thickness, each can be used separately. It was able to demonstrate its reflex ability and demonstrated excellent effects on safety, stability, labor saving, and cost reduction of rice seedling raising technology.

【Effect of the invention】

As described above, the present invention relates to an agricultural plastic film having a multilayer structure in which reflected light with different amounts and qualities of light can be obtained on the front and back sides. Therefore, use films with each performance. By molding each film to half the thickness of those used alone, it is possible to provide economical and rational agricultural films at low cost and requiring half the storage space. .

[Brief explanation of drawings]

FIGS. 1 to 5 are enlarged vertical cross-sectional views of agricultural plastic films according to embodiments of the present invention, FIGS. 6 and 7 are cross-sectional views showing the state in which they are used for cultivating fruit trees, and FIGS. Figure 9 is a cross-sectional view showing an example of use for temperature control of cultivated soil.
Figures 10 and 11 are cross-sectional views of main parts showing the conditions when used for raising paddy rice seedlings, Figure 12 is a graph showing the relationship between reflectance and temperature, and Figure 13 is a graph showing the relationship between light wavelength and reflectance. A graph showing the relationship, Figure 14 is a graph showing the repellent effect on winged insects,
FIG. 15 is a graph showing the effect of reflective film on orchard height. The names of the main parts in the drawings are as follows. 11... First layer (aluminum particle mixed layer) 12...
・Second layer (aluminum vapor deposition or titanium oxide mixed II) 13...Adhesive layer 14...Transparent film layer Table 1

Claims (1)

[Claims] 1. Visible light reflectance is 40% or more and light shielding rate is 80%.
As described above, the difference in visible light reflectance between the front and back surfaces of the film is 6% or more, and the difference in reflectance between the front and back surfaces of the film in the ultraviolet region of 290 to 390 nm is 30% or more. A multilayer agricultural plastic film made of polyolefin resin or vinyl chloride resin formed by extrusion or adhesive processing. 2. A first layer containing 0.4 to 1.5 g/m^2 of aluminum particles to give a visible light reflectance of 40 to 55%, and a vapor-deposited layer of aluminum to suppress reflection in the ultraviolet region and make it visible An agricultural plastic film having a second layer having a light reflectance of 50 to 95%. 3. The first layer contains 0.4 to 1.5 g/m^2 of aluminum particles to give a visible light reflectance of 40 to 55%, and any of titanium oxide, talc, magnesium chloride, or lead oxide 5.0-40.0g of one or more reflective materials
/m^2 to suppress reflection in the ultraviolet region and make the reflectance of visible light 50 to 95%.