JPS6141530A - Ground-temperature drop multing film - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mulching film that is used for growing crops, covers the ground in summer, promotes lowering of soil temperature, and prevents weeds from growing. Regarding a laminated film consisting of a white or silver reflective film layer, a black film layer that completely absorbs the transmission of light from the reflective film layer, and holes and air spaces. Generally speaking, mulching film is made of soil. Mulching is carried out for the purpose of retaining soil moisture, raising soil temperature, and preventing fertilizer components from being washed away.Although mulching in the summer is effective in retaining soil moisture and preventing fertilizer components from being washed away, it is often used when the soil temperature is too high. This has resulted in conditions unsuitable for crop cultivation, and on the other hand, there are problems such as a significant proliferation of weeds.

Transparent polyethylene film, which is the most common conventional mulching film, is unsuitable for crop cultivation when used in the summer because it prevents sunlight from passing through, causes soil temperature to rise, and weeds to grow. In addition, although black mulching film has the effect of preventing weeds from growing, it absorbs sunlight and raises the temperature, making it unsuitable for use in the summer to lower soil temperature. 〇The above drawbacks have been improved. For this reason, white mulching films containing titanium oxide and silver polyethylene films containing aluminum powder are available as summer mulching films, but these films are insufficient in lowering soil temperature and have poor weed prevention effects. Unfortunately, a mulching material that satisfies both of these requirements has not been obtained.

In addition, films made of polyethylene film with aluminum vapor-deposited 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 and falls apart. disadvantages that are easy to develop,
Furthermore, it is not widely used because it is expensive.
In addition, a black and white laminated type mulching film has been provided so far (Utility Model Publication No. 55-88869), but although it is effective in preventing the growth of weeds, it is still insufficient in its effect on the drop in soil temperature in summer.

The present invention was achieved as a result of various studies aimed at providing a mulching film suitable for summer crop cultivation, which has a function of lowering soil temperature and prevents the growth of weeds.

That is, the present invention consists of (1) laminating a thermoplastic resin film containing titanium oxide or aluminum powder and a thermoplastic resin film containing carbon black, and (2) each film has pores (pore diameter 0). .3-10%%
This relates to a novel mulching film characterized in that the peripheral part of the mulching film (φ, open area ratio 0.1 to 5) is welded, but other parts have an air layer and are not completely adhered. .

Furthermore, in detail, a thermoplastic resin film containing 10 to 30 weight of titanium oxide powder or 5 to 30 weight of aluminum powder and a thermoplastic resin film containing 2 to 10 weight of carbon 1 fufu are superimposed, and then the thermoplastic resin film is melt-cut. Hole diameter 0.3~10■φ formed by drilling
, a laminated film having through holes with a porosity of 0.1 to 5 m, the laminated film is welded around the through holes, other parts have an air layer, and the entire laminated film is welded. Wall thickness is 10~
This is a mulching film characterized by having a thickness of 75μ, and it relates to a film that has excellent effects on lowering soil temperature in summer and preventing the growth of weeds. Figure 1 is a perspective view showing an example of the mulching film of the present invention. , FIG. 2 is a sectional view thereof.

In the figure, a thermoplastic resin film ■ containing titanium oxide powder or aluminum powder and a thermoplastic resin film ■ containing carbon black are overlapped, and the area around the zero through hole ■ is where a through hole ■ is formed by fusing and perforating. The thermoplastic resin used in the present invention includes 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 homopolymers and copolymers such as ethylene vinyl acetate-methyl methacrylate copolymer, polypropylene, vinyl chloride resin, etc. can be used, and these can be used alone or in combination. .

Further, the resins of the titanium oxide or aluminum powder-containing film layer and the carbon black-containing film layer may be the same or different. The laminated film of the present invention can be manufactured by the following process. .

A thermoplastic resin composition containing titanium oxide or aluminum powder and carbon black is prepared by mixing and kneading the powder while melting the resin using an ordinary Banbury mixer, two-roll kneader, or extrusion kneader. can get.

The obtained resin composition is obtained by separately processing a resin composition containing titanium oxide or aluminum powder and a resin composition containing carbon black using a film processing machine such as ordinary blown film processing, T-die film processing, or calendar processing. Either by film molding or by using a special two-color inflation film die, extrude each resin composition in a two-layer extrusion mode, and in the two-color die part, the half circumference of the film tube is coated with a titanium oxide or aluminum powder-containing layer. Next, the other half of the periphery is formed into a film by two-color tubular film processing to become a carbon black-containing layer.

Among these, the method using a two-color tubular film is preferable since the superposition step can be omitted.

Next, after overlapping the titanium oxide or aluminum powder-containing film and the carbon black-containing film, a hole with a predetermined diameter and aperture ratio is made using a fusing punch, and at the same time, the surrounding area of the hole is welded. Two types of films are laminated together.

The film thickness of each layer is 371 and 5 from the handling surface.
~30μ is appropriate, and the total film thickness after lamination is preferably 10~75μ.

Drilling with a fusing drill is performed with a hole diameter of 0.3 to 10W in order to both lower the soil temperature and prevent weeds from growing. φ open area ratio 0
．． The pore size is preferably in the range of 1 to 5 mm, and more preferably 0.5 to 8 mm in diameter. If the diameter and opening ratio of the holes do not meet 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 reduced. I don't like it.

The mulching film obtained as described above reflects sunlight by the film layer containing titanium oxide or aluminum powder, completely absorbs sunlight by the film layer containing carbon black, and has a film layer between the two layers. As a result of the insulation provided by the air layer and the promotion of air circulation between the inner and outer surfaces of the mulch due to the perforations, when mulch is applied to the ground in summer, the effect of lowering the soil temperature is amplified and the growth of weeds is prevented. Therefore, the mulching film of the present invention can
It is ideal for flatland cultivation of highland lettuce, which is usually grown in highlands where it is cool in the summer, and cultivation of summer and autumn cucumbers, suppressed tomatoes, spinach, etc. ◇ Next, the present invention will be explained with examples. However, these examples are merely illustrative and not limiting.

Measurement of soil temperature under the mulching film and observation of weed growth shown in Examples and Comparative Examples were carried out in the following manner.

Each film was mulched in a ridge with a width of 1 m, a 4% width of 2 m, and a height of 203 mm, and the soil temperature was measured at a fixed depth of 63 mm from the ground surface.In addition, weed growth was observed after 30 days of mulching in summer. The condition of the ridges when the film was removed was investigated.

Example 1 Ethylene-butene-1 copolymer (density 0.921°Mr
= 21,710 minutes) 100 parts by weight, 25 parts by weight of titanium oxide (/L/CH μ type) powder, and 0.8 parts by weight of glycerin monostearate as a dispersant. After kneading for 10 minutes, granulated pellets were produced using an extruder.Hereinafter, the above mixture will be referred to as A mixed resin.

In addition, 100 parts by weight of the same ethylene-butene copolymer as above, 5 parts by weight of car pump hooks, and 0 or 1 part by weight of glycerin monostearate as a dispersant were mixed and granulated in the same manner as above to produce pellets. 0 or less, this mixture will be referred to as B mixed resin.

Next, using a two-color blown film processing machine equipped with two extruders and two-color dies, the above A mixed resin and B
The mixed resin is put into separate extruders, and the melting zone is 220℃.
At a die temperature of 200° C., a two-color film having a thickness of 15 microns was molded, with half the circumference of the tubular film being the A mixed resin layer and the other half being the B mixed resin layer.

The obtained film was folded exactly at the interface between the mixed resin layer A and the mixed resin layer B, and was overlapped.
A 1.5-diameter hole was punched using a fusing punch so that the opening ratio was 0.2-, and the periphery of the hole was heat-sealed to obtain a perforated bonded film. The obtained film is heat-sealed around the pores, and the other parts are in an overlapping state, and strictly speaking, it has an air layer.

Tests for soil temperature lowering effect and weed growth were conducted by mulching with the B mixed resin layer on the inside (ground side), and the results are shown in Table 1.

Example 2 Low density polyethylene (density 0.928, MI=1.5
) 100 parts by weight, mica powder coated with titanium oxide (pearl pigment) 30 wtjl and glyceryl monostearate as a dispersant) 0.83 parts were kneaded and prepared in the same manner as in Example 1. The mixed resin B was produced in the same manner as in Example 1, except that the mixed resin A was pelletized to produce pellets of the mixed resin A, and a two-color inflation film was added, and a perforated laminated film was obtained using a fusing punch.

The performance of the obtained film is shown in Table 1. 〇Example 8 A perforated film was produced in the same manner as in Example 1, except that the titanium oxide used in the mixed resin A in Example 1 was changed to 15 parts by weight of aluminum powder. A composite film was obtained. The performance of the obtained film is shown in Table 1.0 Comparative Example 1 Only the mixed resin A 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 Only the mixed resin A of Example 8 was processed into a film using a normal blown film processing machine to obtain a single layer film with a thickness of 30 microns.

The performance of the obtained film is shown in Table 1 @ Comparative Example 8 A two-layer blown film processing machine equipped with two extruders and a two-layer die for processing mixed resin A and mixed resin B used in Example 1 An A/B laminated film was obtained using the following.

The obtained film was a completely fused and laminated layer of A mixed resin layer (15 microns thick) and B mixed resin layer (15 microns thick).The performance of this film was examined using the same method as in Example 1. It is shown in Table 1.

Comparative Example 4 An A/B laminated film was obtained using the A mixed resin and the B mixed resin used in Example 8 using a two-layer blown film processing machine equipped with two extruders and a two-layer die. The obtained film had a mixed resin layer A (15 microns thick) and a mixed resin layer B (15 microns thick) completely fused and laminated. The performance of this film was examined in the same manner as in Example 1 and is shown in Table 1.

Comparative Example 5 Ethylene-butene-1 copolymer (Dense & 0.921MI=
2F/10 minutes) using a normal inflation 7JL machine to obtain a transparent film with a thickness of 30 microns.◇ The performance of the obtained film is shown in Table 1.

As is clear from Table 1, it is clear that the present invention has a superior soil temperature lowering effect compared to conventional mulching films, and is also effective in preventing the growth of weeds.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the mulching film of the present invention,
Figure 2 is a cross-sectional view of the same.

Claims (1)

[Claims] It was formed by fusing and perforating a thermoplastic resin film containing 10 to 30% by weight of titanium oxide powder or 5 to 30% by weight of aluminum powder and a thermoplastic resin film containing 2 to 10% by weight of carbon black in a superimposed state. Pore diameter 0.3-10mmφ, porosity 0.1-5
% of the laminated film has a through hole, the laminated film is welded around the through hole, and the other part has an air layer,
A soil temperature lowering mulching film, characterized in that the total thickness of the laminated film is 10 to 75μ.