JPH01139257A - Agricultural multiple film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] <Industrial application field> The present invention covers one area of ground per crop cultivation area in summer,
Mulching film that promotes lowering of soil temperature, prevents weed growth, and has pest repellent effects;

In detail, a light beam consisting of a resin layer containing an inorganic compound that reflects ultraviolet rays other than anatase-type titanium oxide (hereinafter referred to as the first layer) and a resin layer containing anatase-type titanium oxide (hereinafter referred to as the second layer) The present invention relates to a reflective layer and a mulching film for light from the light reflective layer.

<Conventional technology> General mulching film is used for the purpose of retaining soil moisture, increasing soil temperature, and preventing fertilizer components from being washed away. Although it is effective in preventing the leaching of ingredients, there are problems such as the soil temperature becoming too high, making it unsuitable for crop cultivation, and on the other hand, weeds are growing rapidly.

When transparent polyethylene film, which is the most common conventional mulching film, is used in the summer, it is unsuitable for crop cultivation because it allows more sunlight to pass through, increases soil temperature, and causes weeds to grow. Furthermore, although the black fulching film has the effect of preventing weeds and overgrowth, it absorbs sunlight and raises the temperature, so it is not suitable for use in the summer with the purpose of lowering the soil temperature.

<Problems to be Solved by the Invention> In order to improve the above drawbacks, white mulching films containing titanium oxide and silver polyethylene films containing aluminum powder gold have been provided as summer mulching films. , respectively, have insufficient pest control effects, insufficient soil temperature control effects, and poor weather resistance, and a mulching material that satisfies both has not yet been obtained.

In addition, films made by vapor-depositing aluminum on polyethylene film or films laminated with aluminum foil are also used for cultivating some crops, but when used, the vapor-deposited film or aluminum foil peels off or oxidizes, resulting in crumbling Cζ. It has not been widely used due to its shortcomings and high price.

In addition, a hot black and white laminated type mulching film has been provided so far (Japanese Utility Model Publication No. 65-88869), but although it has the effect of preventing weed growth, it is still insufficient in its effect against the drop in soil temperature in the summer. In terms of pest and disease effects, the present invention provides a mulching film suitable for summer crop cultivation, which has excellent weather resistance, soil temperature lowering function, and prevention of weed growth. For the purpose of repelling pests (ζ),
This was achieved as a result of various studies.

That is, the present invention excludes anatase titanium oxide,
a first resin layer containing an inorganic compound that reflects ultraviolet rays; a second resin layer containing anatase titanium oxide;
The present invention relates to a novel agricultural mulching film characterized by comprising three layers: a third layer of mlif layer containing carbon black.

Examples of inorganic compounds having ultraviolet reflective properties other than anatase-type titanium oxide used in this layer (layer) of the present invention include titanate compounds such as potassium titanate, calcium titanate, and barium titanate, zirconium silicate, and Various compounds include zirconium compounds such as zirconium, magnesium oxide, zinc oxide, and zinc sulfide, among which potassium titanate, calcium titanate, barium titanate, zirconium oxide, zinc oxide, and lead sulfide have UV reflective properties. Preferred because of its high quality.

The anatase-type titanium oxide used in the second layer of the present invention is distinguished from rutile-type titanium oxide, and has reflective properties in the ultraviolet region.

The purpose of the carbon black used in the third layer 1ζ of the present invention is to completely absorb the transmission of light, and there is no particular limitation, and ordinary carbon black powder is suitable.

The thermoplastic resins used in each layer of the present invention include low density polyethylene, high density polyethylene, ethylene-butene-1 copolymer, ethylene-4-methyl-pentene-
1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-vinyl acetate-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, etc. , ethylene homopolymers and copolymers, polypropylene, vinyl chloride resins, etc. can be used, and these can be used alone or in combination. Moreover, the resins of the first layer, second layer, and third layer may be the same or different.

The three-layer film of the present invention can be manufactured by the following steps.

Each thermoplastic resin composition used in the first layer, the second layer, and the third layer 1ζ is blended in one batch while melting them all using an ordinary Banbury mixer, two-roll mixer, or extrusion mixer. It is obtained by mixing and kneading inorganic compounds and carbon black powder.

The resin compositions used for the obtained 1st layer, 2nd layer and 3rd layer are separately produced from 8 extruders equipped with 3-layer extrusion dies!
A three-layer, three-layer film is formed by a coextrusion film processing method in which the film is processed by extrusion.

The film thickness composition ratio of the 1st layer, 2nd layer, 2nd layer, and 3rd layer is preferably 1 to 8/2 to 4/3 to 7 from the viewpoint of cost and processability. Thickness is 10-7
6μ is preferred.

In addition, the content of the inorganic compound in the first layer is 0.5 to ao%, and the content of anatase type titanium oxide in the second layer is 1 to 8%.
It is preferable that the content of the inorganic compound in the first layer is 6 to 80% by weight, and the content of anatase type titanium obfuscated in the second layer is 5 to aotm% to reflect near infrared and ultraviolet rays. is higher and more preferable. The carbon black content of the third layer is preferably 2 to 10% in order to completely absorb solar rays.

Further] ζ, the coextruded three-layer film has a pore size of 0.3
By providing a pot with through holes of ~10-g〆 and a porosity of 0.1-5%, it is possible to more effectively lower the soil temperature.

The holes may be formed in-line at the same time as the film is processed, or may be formed by passing a hole through a separate line, and they can be formed by ordinary punching, hot needle drilling, or the like.

In order to achieve both the effect of lowering the soil temperature and the prevention of weed growth, the through holes should preferably have a diameter of 0.8 to lOw', a pore size of 0.1 to 5%, and a diameter of 0.5 to 8 Wd. Gasara 1
This is preferable. If the diameter and opening ratio of the holes to be provided are below the above range, the soil temperature lowering effect will be insufficient; on the other hand, if it exceeds the above range, the soil temperature lowering effect will be excellent, but the effect of suppressing weed growth will be lowered, which is undesirable. .

<Effects> The three-layer mulching film obtained as described above has the following properties:
The second layer and the second layer (ζ reflect near-infrared rays to suppress the increase in soil temperature, and the carbon black-containing film layer (thereby completely absorbs sunlight and has the effect of preventing weeds from growing).

In addition, the second layer and the second layer have high ultraviolet reflectivity, and this 1ζ exerts a repellent effect on crop pests such as aphids and Thrilaps.

In addition, anatase-type titanium oxide generally has poor weather resistance, and its use with resin number ζ has been generally avoided. It has been found that weather resistance can be significantly improved by laminating layers containing high inorganic compounds.

The mulching film of the present invention is ideal for flatland cultivation such as highland lettuce, which is usually grown in summer (ζ is a cool highland), summer and autumn cucumbers, suppressed tomatoes, spinach, etc.

In addition, a mulching film in which through-holes are provided in the film promotes the circulation of air between the inner and outer surfaces of the mulch due to the perforations, and the effect of lowering the soil temperature is further amplified. These embodiments are merely illustrative and are not intended to be limiting.

Tests for measuring the soil temperature under the mulching film, observing the state of weed growth, and observing the insect repellency shown in the Examples and Comparative Examples were conducted in the following manner.

Each film was mulched in a ridge with a width of 1 m, a length of 10 m, and a height of 20 α, and the soil temperature was measured at a fixed depth of 51 mm from the ground surface.

To observe the state of weed growth, we examined the state of the ridges when the film was removed after 80 days of mulching in summer.

In addition, pest repellency was determined by examining the number of southern yellow thrips or aphids (winged insects) (per 40 cucumber leaves) during 80 days of mulching cultivation.

The weather resistance of the film was determined by exposing the film to 1 light using a sunshine feather meter at a black panel temperature of 68°C and water spray for 18 minutes/120 minutes. I looked into it.

The sunshine light was applied to a resin layer containing an inorganic compound having ultraviolet reflecting properties.

Example 1 Ethylene-butene-1 copolymer (density 0.921.MI = 2F/10 min) 100% polyurethane and potassium titanate (Tismo D, manufactured by Otsuka Chemical) 10
Glycerin monostearate as weight part and dispersant 0.
After kneading 8 parts by weight and 0.8 parts by weight of Nasuvin 622 (manufactured by Ciba Geigy) as a weathering agent in a 5e Banbury mixer at a resin temperature of 150 to 160 C for 10 minutes, granulated pellets were produced using an extruder. Hereinafter, the above mixture will be referred to as A mixed resin (rubbing).

In addition, the same ethylene-butene-1 copolymer too
i quantitative part and anatase type titanium oxide (quantified titanium oxide JA
-4. Teikoku Kakogyo) 10 heavy weight and glycerin monos as a dispersant were mixed and granulated to produce pellets. below,
This mixture is referred to as B mixed resin.

Furthermore, 100 parts by weight of the same ethylene-butene-1 copolymer as above, 5 parts by weight of carbon black, and 0.1 part of glycerin monostearate as a dispersant were mixed together in the same way as above and granulated. Pellets were produced. Hereinafter, this mixture will be referred to as C mixed resin.

Next, using a three-layer inflation silane film processing machine equipped with two extruders and seven three-layer dies, the above mixed resin A, mixed resin B, and mixed resin C were put into separate extruders. Then, under the conditions of a melting zone of 220°C and a die temperature of 200°C, a mixed resin layer A, a mixed resin layer B, and a mixed resin layer C were formed in a three-layer die.
A three-layer laminated film was molded while melting and adhering the mixed resin. The obtained film had a thickness composition ratio of A mixed resin layer/B mixed resin layer/C mixed resin III layer of 1/1/l,
The total thickness was 80μ. The film performance was tested by mulching the film so that the A mixed resin layer covered one layer on the outside, and the results are shown in Table 1.

Example 2 Example 1 (In this case, A mixture!
lith■5AC)rrLEBEN CHME GMB
The A mixed resin pellets were obtained by mixing and granulating in the same manner as in Example 1, except that the weight value of 1O0 (manufactured by H) was used. A three-layer film was obtained in the same manner, and the resulting film had a thickness composition ratio of 1/1/l and a total thickness of 80 μm.

The performance of the obtained film is shown in Table 1.

Example 8 The three-layer film obtained in Example 1 was further punched with one 1.5.t1 hole using a hot needle punching machine so that the aperture ratio was 0.2%. A perforated film was formed.

The performance of the obtained film is shown in Table 1. Example 4 Ethylene-butene-1 copolymer (density 0.919, MI = 0.9 f/10 min) 1000
Zero weight zirconium oxide (zirconium oxide EP, fi
- Kigenso Kagaku Kogyo Co., Ltd.) 15 parts by weight, 0.4 parts by weight of glycerin monostearate as a dispersant, and 6220.8 parts by weight of Nasvin as a weathering agent were kneaded and produced in the same manner as in Example 1. The mixture was granulated to obtain A mixed resin.

In addition, the same ethylene-butene-1 copolymer 100 as above
Weight parts and anatase type titanium oxide (Roka titanium oxide JA
-4. Teikoku Kagaku) 15 parts by weight as a dispersant, 0.4 parts by weight of glycerin monostearate, and 0.8 parts by weight of Nasvin 622 (manufactured by Ciba Geigy) as a weathering agent (strained and kneaded). , and granulation to obtain B mixed resin.

Furthermore, high pressure polyethylene (density 0.924.M
I=IJ5) 100 parts by weight, 8 parts of carbon black, and glycerin monostearate o, igt as a dispersant
It part is mixed and granulated in the same manner as above, and C mixed m
I got fat.

Next, a 311 film was produced in the same manner as in Example 1 using mixed resin A, mixed resin B, and mixed resin C.

The obtained film has A mixed resin layer/B mixed resin @/C
The thickness composition ratio of the mixed resin layer is 1/1/2, and the total thickness is 80μ.
The film performance was tested by fulching with the Afi base resin layer on the outside, and the results are shown in Table ttc.

Comparative Example 1 Only the C mixed resin of Example 1 was processed into a film using a normal blown film processing machine to obtain a single layer film with a thickness of 30 microns. Table 1 shows the performance of the obtained film.

Comparative Example 2 Using the B mixed resin and C mixed resin of Example 1, Example 1
A film was processed in the same manner as above to obtain a film having a thickness composition ratio of B mixed resin layer/C mixed resin layer of 1/l and a total thickness of 80 μm, which was substantially one and two layers.

The film performance was tested by fulching the film with the B mixed resin layer on the outside, and the results are shown in Table 1.

Comparative Example 2 In Example 1, rutile type titanium oxide (R-55
A three-layer film was obtained by repeating the same method as in Example 1, except that the toitm part (manufactured by Ishihara Sangyo Co., Ltd.) was used.

The obtained film has A mixed resin f@/B mixed resin layer/
The thickness composition ratio of the C mixed resin layer is l/1/l, and the total thickness is 8
It was 0μ. Table 1 shows the performance of the obtained film.

Comparative Example 4 Comparative Example 8 (A film was processed in the same manner as in Example 1 using the B mixed resin mixed with rutile-type titanium oxide used in this example and the C mixed resin used in Example 11). ,
The thickness composition ratio of the B mixed resin layer/C mixed resin layer is 1/l,
A substantially two-layer film with a total thickness of 30 μm was obtained.

Table 1 shows the performance of the obtained film.

＼ ＼ ＼8, ＼5, ＼, As is clear from Table 1, the present invention has a better soil temperature control effect than conventional mulching films (it is clear that it has a pest repellent effect, and it also has a weed control effect). It was also found to be effective in preventing overgrowth.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the mulching film of the present invention,
FIG. 2 is a sectional view thereof. ■ Resin layer containing an inorganic compound with ultraviolet reflective properties ■ Resin layer containing anatase titanium oxide ■ Resin layer containing carbon black Old 1 Figure 2

Claims (3)

[Claims] (1) The first layer is a resin layer containing an inorganic compound with ultraviolet reflective properties other than anatase titanium oxide, the second layer is a resin layer containing anatase titanium oxide, and the third layer is a resin containing carbon black. An agricultural mulching film characterized by having a three-layer structure. (2) The content of the inorganic compound in the first layer is 0.5 to 30% by weight, and the content of anatase type titanium oxide in the second layer is 1 to 3% by weight.
0% by weight, the content of carbon black in the third layer is 2-1
0% by weight, and the thickness ratio of the first layer/second layer/third layer is 1 to 3/2 to 4/3 to 7. The agricultural mulching film according to claim 1. (3) A film consisting of three layers has a pore size of 0.3 to 10
The agricultural mulching film according to claim 1 or 2, characterized in that it has pores with a diameter of mmφ and a porosity of 0.1 to 5%.