JPH0523331Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a shading net, and is particularly applicable to various types of agriculture,
This article relates to excellent shading nets used in gardening.

[Conventional technology]

2. Description of the Related Art When growing various agricultural products and horticultural crops, sheet and net-shaped shading materials are used in many places for shading the plants.

Examples of light-shielding materials include synthetic resin threads colored black, etc., constructed into a relatively rough woven structure with ventilation gaps, and synthetic resin tapes colored black, etc., woven or woven with ventilation gaps. The organized version has been commonly used.

[Problem that the invention attempts to solve]

However, since the above-mentioned shading materials absorb heat energy through coloring, the temperature rises due to heat absorption at the same time as shading, and the interior covered by the shading material becomes abnormally high temperature, making it difficult for plants to grow. tended to be an unsuitable environment. To solve this problem, nets and sheets have been proposed that use synthetic resin tape mixed with aluminum powder to increase the reflectance of sunlight.
Reflection efficiency was not sufficient, and there was a need for even better light-shielding materials.

[Means for solving problems]

As a result of various studies to solve the problems with the above-mentioned light-shielding materials, the inventors of the present invention found that by providing a reflective metal layer on a specific net and a protective layer on top of it, the sun's rays could be reflected sufficiently. However, the present invention was developed based on the knowledge that a light-shielding net having high strength and excellent effects such as fewer manufacturing steps can be obtained.

That is, the gist of the present invention resides in a light-shielding net formed by laminating thermoplastic resin split fibers and sequentially laminating a reflective metal layer and a thermoplastic resin layer on the net with the fiber directions crossing each other.

The present invention will be explained in detail below.

The split fiber used in the present invention is a synthetic resin film with a large number of discontinuous fissures in the stretching direction to form a net shape.

The thermoplastic resin may be one that can be formed into a film, and examples thereof include polyolefins such as polyethylene and polypropylene, polyester, polyamide, polycarbonate, and polyvinyl chloride. Preferably, polyolefin is used, more preferably high-density polyethylene.

After this synthetic resin is formed into a film, it is uniaxially stretched to form a film having a thickness of usually 3 to 100 μm, preferably 5 to 50 μm. Since the film is made into a split fiber during the film formation and/or uniaxial stretching process, it is in a state where cracks are likely to occur. This state is called fibrillation (fibrillation)
When using high-density polyethylene, polypropylene, etc., which are easy to process, the film is formed by, for example, inflation molding using a circular die, T-die extrusion molding, etc., and then uniaxial high-magnification stretching using a stretching method such as roll stretching.
For example, it is formed by stretching 5 to 10 times. In addition, in the case of synthetic resins that are difficult to fibrillate, foaming agents such as propane, petroleum ether, carbon dioxide, diazoamino derivatives, azonitrile, and azodicarboxylic acid derivatives are added during film formation, and the resulting film is uniaxially formed. It is formed by stretching. Split fibers can be obtained by cracking the above-mentioned film by a well-known method such as beating, twisting, cutting, friction, air flow, etc. to form discontinuous fissures. The size of the single fiber of the split fiber is usually 3 to 100 deniers, preferably 5 to 50 deniers.

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a longitudinal sectional view of a light-shielding net, and FIG. 2 is an example of a plan view of the net made of split fiber as a base material.

The split fibers 1 and 1' are stacked so that their fiber directions are different, that is, in a crossed state. The intersection angle 5 is usually 45 to 135 degrees, preferably 70 to 110 degrees. The number of layers of split fibers to be laminated is not limited, but is usually 2 to 5.
It is considered to be a layer. The stacked split fibers 1 and 1' are fixed in a net shape using heat fusion or adhesive.

Examples of such nets include "Warif" (product name, manufactured by Nippon Petrochemical Co., Ltd.) and "Tuffbel" (product name,
Commercially available products such as those manufactured by Kanebo Co., Ltd.) can also be used.

Various metals such as aluminum, tin, zinc, copper, chromium, stainless steel, and silver can be used as the metal for the reflective metal layer 2 provided on the net formed by stacking split fibers. Among them, aluminum and stainless steel are preferably used because they have a high reflectance of sunlight and are relatively inexpensive.

The method for laminating the metal on the net is not particularly limited as long as it is a known vapor deposition method. Examples include resistance heating, vacuum deposition such as flash deposition, arc deposition, electron beam deposition, and laser deposition, and sputtering methods such as ion beam sputtering and magnetron sputtering. The sputtering method is preferred because the base material net is deposited at a relatively low temperature.

The thickness of the reflective metal layer 2 varies depending on the type of metal, but in the case of aluminum, it is usually 100 to 800 mm.
Å, preferably 400 to 600 Å.

The thermoplastic resin used for the thermoplastic resin layer 3 laminated on the reflective metal layer 2 is not particularly limited as long as it has weather resistance. Preferably, polyolefins are used, particularly preferably polyethylene and polypropylene.

The thermoplastic resin used for the thermoplastic resin layer 3 and the aforementioned split fibers 1 and 1' includes:
Ultraviolet absorbers, fillers, etc. can be added according to conventional methods. In particular, it is preferable to use an ultraviolet absorber in the thermoplastic resin layer to improve weather resistance. The ultraviolet absorber may be any one that can be used in ordinary organic polymer materials, such as benzophenones such as 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-octoxybenzophenone; Salicylic acid derivatives such as pt-butylphenyl salicylate, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-
Benzotriazoles such as methylphenyl)-5-chlorobenzotriazole, [bis(3,5-
Examples include nickel complexes such as di-t-butyl-4-hydroxybenzyl)phosphonic acid monoethyl ester nickel salt, naphthalene tetracarboxylic acid, its anhydride, imide, or ester. These UV absorbers are typically 100~
10000ppm used.

The thermoplastic resin layer 3 is laminated by a method that allows thin coating without blocking the openings 4 so as not to impair the air permeability of the net, for example, using an air knife, a coater, or the like. This thermoplastic resin layer 3 is usually 5 to 50 μm, preferably 10 to 20 μm
The thickness is said to be .

The shading rate of the shading net of this invention is usually 2 to 60.
%, preferably 5 to 40%. By selecting the porosity of the net, the metal of the reflective metal layer 2, etc. in consideration of the target plants for which the shade net will be used, the place of use, ventilation, etc., it is possible to obtain a shade net with an appropriate shade rate. .

[Effect of idea]

Since the light-shielding net of the present invention has a high reflectance, (1) it can be used in agricultural greenhouses to shade various plants by hanging the net along the frame of the greenhouse;

(2) By placing it horizontally to the ground without using a greenhouse, it can be used to protect tea from frost and shade, and to shade shiitake mushrooms.

(3) It can be used as mulch to spread around the roots of crops, preventing soil temperature from rising and allowing reflected sunlight to shine on the crops.

(4) It has a bird-preventing effect when placed in orchards, etc.

In addition, since the split fiber has undergone uniaxial stretching, its strength is high both vertically and horizontally. Furthermore, since it has higher flatness than conventional light-shielding nets, it is less bulky, and when using a commercially available net made of split fiber, it is only necessary to provide a reflective metal layer and a thermoplastic resin layer on the net, which requires fewer steps. It can be manufactured by

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the light-shielding net of the present invention, and FIG. 2 is a plan view of the net made of split fiber as a base material. 1, 1'... Split fiber, 2... Reflective metal layer, 3... Thermoplastic resin layer, 4... Opening portion, 5... Intersection angle.

Claims (1)

[Claims for Utility Model Registration] (1) A light-shielding net made by laminating thermoplastic resin split fibers and sequentially laminating a reflective metal layer and a thermoplastic resin layer on the net with the fiber directions crossed. (2) The light-shielding net according to claim 1, wherein the thermoplastic resin is polyethylene or polypropylene. (3) The light-shielding net according to claim 1, wherein the reflective metal layer is an aluminum layer.