JPH0999529A - Agricultural polyolefinic multilayered film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agricultural film having high dust proofness and band wearing property, good in flexibility, transparency and tear strength and no generating environmental pollution at a time of incineration wasting. SOLUTION: In an agricultural polyolefinic film having two or more multilayered structures, the surface film of the film facing to an object ready to be coated at least when the film is developed is composed of a compsn. based on high density polyethylene with a density of 0.94-0.97g/cm<3> .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agricultural polyolefin-based multilayer film used as a covering material for facility horticulture such as agricultural houses and tunnels. More specifically, when it is spread in a house or tunnel, the outer surface of the house does not easily get dirty (dust resistance), and it has excellent transparency, band rub resistance (damage resistance), tear strength, and environmental pollution during incineration disposal. The present invention relates to an agricultural film excellent in performance balance that does not cause

[0002]

2. Description of the Related Art A large amount of plastic film is used as a covering material for facility horticulture such as greenhouses and tunnels. Agricultural plastics made of polyvinyl chloride resin and low density polyethylene resin are typically used. Agricultural poly, agricultural vinyl chloride using ethylene vinyl acetate copolymer resin, etc. can be mentioned, among which agricultural vinyl is excellent in heat retention, transparency, toughness, anti-fogging property, house adhesion and economical efficiency. The most used. However, agricultural plastics are inferior in workability and dust resistance due to the plasticizer contained in the film bleeding out and stickiness on the surface, and recently, various problems such as generating harmful gas at the time of incineration disposal have occurred. Yes, and a substitute for it is desired.

Agricultural poly and agricultural vinegar have advantages over agricultural vine in terms of workability and disposal, but the film surface layer on the opposite side has a great influence on the object to be coated. There is a problem that dust resistance, band rubbing, toughness, transparency and heat retention are poor.

The dustproof property has a great influence on the light transmittance after spreading, and if the dustproof property is lacking, the light transmittance decreases.
Crop growth is hindered and crop yields are reduced. Band rubbing is fixed by a band from the outside when the agricultural film is spread on a frame such as a house or tunnel, but this band causes the disadvantage that the film surface is rubbed and loses its strength and is easily torn due to stress. .

On the other hand, high-density polyethylene is excellent in toughness such as dustproofness, scratch resistance, tear strength, and tensile strength, but is inferior in flexibility, elastic recovery is difficult, and lacks in transparency. For this reason, it has not been used as a covering material for agricultural gardens and facility gardening such as tunnels. Transparency is important not only because it is a necessary property for the growth of crops, but also because the growth status can be observed from the outside. Flexibility is a characteristic required when an agricultural film is stretched on a frame such as a house or tunnel.If the flexibility is poor, wrinkles may occur on the film during stretching, or a gap may be left between the film and the frame. Inconvenience occurs.

As a solution to the above-mentioned problems of flexibility and elastic recovery of high-density polyethylene, a film in which an olefin rubber is added to high-density polyethylene is disclosed in JP-A-56-
Although disclosed in Japanese Patent No. 116735, when a film according to the present technology is stretched in a house or a tunnel, it is easy to tear when a stress is applied to the end of the film. There was a problem that the film was easily torn. Particularly in the case of a film made of a composition having improved transparency, the film tends to be easily torn, and is not practical as a covering material for agricultural houses, tunnels and the like.

[0007]

DISCLOSURE OF THE INVENTION As described above, the workability for spreading is excellent, the dust resistance and the band rub resistance are high, and the tear strength, the transparency, the flexibility, etc. are also good, and the disposal processing is performed. A film which has a well-balanced and sufficient characteristic that is also preferable in terms of the above has not been obtained so far.

[0008]

Means for Solving the Problems The inventors of the present invention have solved the above problems of agricultural vinyl, agricultural poly, agricultural vinegar, and agricultural films obtained by adding an olefin rubber to a high-density polyethylene resin. As a result of diligent research to achieve, in the agricultural polyolefin film, the structure is a multilayer structure, the surface layer of the film facing the side opposite to the object side to be covered when the film is spread, Agricultural polyolefin-based film containing high density polyethylene having a density of 0.94 to 0.97 g / cm ³ , and
By using a film containing an elastic polymer or an inorganic filler in the surface layer, it has high dust resistance and band rub resistance, excellent flexibility, tear strength, transparency, and has no problem in disposal. It was found that a good agricultural film was obtained, and the present invention was completed.

The present invention is as follows. (1) An agricultural polyolefin film having a multilayer structure of two or more layers, wherein the surface layer of the film facing at least the side opposite to the object side to be covered when the film is spread has a density Is 0.94 to 0.97 g / c
A polyolefin multi-layer film for agriculture, which is a surface layer of a film composed of a composition containing m ³ of high-density polyethylene as a main component. (2) The high density polyethylene having a density of 0.94 to 0.97 g / cm ³ has a melt flow rate (measurement temperature is 190 ° C., load is 2.16 kgf, JIS K-7).
(According to 210) 0.1-5.0 g / 10 minutes, ratio Mw / Mn of weight average molecular weight Mw and number average molecular weight Mn is 3 to 1
The agricultural polyolefin-based multilayer film according to item (1), which has a range of 0. (3) The composition containing the high-density polyethylene as a main component contains the elastic polymer in an amount of 5 to 30% by weight based on the composition, (1) or (2). Agricultural polyolefin-based multilayer film. (4) The agriculture according to any one of (1) to (3) above, wherein the composition containing high-density polyethylene as a main component contains 0.5 to 20% by weight of an inorganic filler with respect to the composition. Polyolefin-based multilayer film for use. (5) At least one film layer other than the surface layer of the film facing the side opposite to the object side to be covered when being spread has an ultra low density of 0.87 to 0.91 g / cm ^3. Polyethylene, density 0.91 to 0.93 g / cm
^3. The agricultural polyolefin according to any one of (1) to (4) above, which comprises a composition containing at least one kind of synthetic resin selected from the low-density polyethylene of ³ or an ethylene-vinyl acetate copolymer. Series multilayer film.

The present invention will be described in detail below. The high-density polyethylene referred to in the present invention is not limited to a homopolymer of ethylene, and ethylene, propylene, 1-butene, 1-
Pentene, 1-hexene, 4-methyl-1-pentene,
Also included are copolymers with α-olefins such as 1-octene. However, a density of 0.94 to 0.97 g / cm ³ is used.

The density used in the present invention is 0.94 to 0.97.
g / cm ³ high density polyethylene has a melt flow rate (measurement temperature of 190 ° C., load of 2.16 kgf,
Not according to the measuring method of JIS K-7210. Hereinafter, the melt flow rate measured under the measurement conditions is referred to as “MFR” in the present application.
When the measurement is performed under other conditions, it will be referred to as “melt flow rate”, and the measurement conditions will be additionally described. ) Is preferably 0.01 to 5.0 g / 10 minutes. When the MFR is in this range, better performance is obtained in moldability, film tear strength, and transparency.

The molecular weight distribution of the high density polyethylene is not particularly limited, but when the transparency of the film is required, the weight average molecular weight Mw and the number average molecular weight Mn.
A material having a ratio Mw / Mn of 3 to 10 is preferably used. If it is less than 3, it is not easy to produce the resin itself, and if it exceeds 10, it is difficult to obtain transparency. In the present invention, the main component means a component having the largest weight ratio in the composition forming the surface layer.

In the present invention, another olefin polymer may be used in combination with the high density polyethylene. The olefin polymer has, for example, a density of 0.91 to 0.9.
3 g / cm ³ low density polyethylene or linear low density polyethylene, ultra low density polyethylene having a density of 0.87 to 0.91 g / cm ³ , ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, ethylene- Methacrylate copolymer etc. can be mentioned.

The elastic polymer used in the present invention includes:
Examples of known elastic polymers such as ethylene-propylene copolymers, polybutadiene polymers, styrene-butadiene copolymers, styrene-ethylene-butylene copolymers, acrylonitrile-butadiene copolymers, styrene-isoprene copolymers. However, when an ethylene-α-olefin elastic copolymer or a styrene-ethylene-butylene copolymer is added to high-density polyethylene, flexibility and elastic recovery can be improved without decreasing transparency. It is preferably used. These elastic polymers may be used alone or in combination of two or more.

The blending amount of the elastic polymer is preferably 5 to 30% by weight based on the weight of the surface layer. When the compounding amount of the elastic polymer is within this range, better performance can be obtained in the flexibility, elastic recovery property and film strength of the film. The elastic polymer may be used in layers other than the surface layer.

The blending amount of the inorganic filler is preferably 0.5 to 20% by weight based on the weight of the surface layer.
When the compounding amount of the inorganic filler is within this range, better performance can be obtained in tear strength, film physical properties and transparency. The inorganic filler is also similar to the elastic polymer,
It may be used for layers other than the surface layer.

The shape of the inorganic filler is preferably spherical,
An average particle size of about 0.1 μ to 10 μ is preferably used. When the average particle size of the inorganic filler is in this range,
Better performance is obtained in workability and smoothness of the film surface.

Examples of the inorganic filler include silicon oxide, magnesium silicate, aluminum silicate, calcium silicate and other silicate compounds, calcium aluminosilicate, sodium aluminosilicate, aluminosilicate compounds such as potassium aluminosilicate, alumina, sodium aluminate and potassium aluminate. , One or more inorganic fillers selected from the group consisting of aluminate compounds such as calcium aluminate, calcium carbonate, hydrotalcites represented by the following chemical formula 1 and lithium-aluminum complex hydroxide salt represented by the following chemical formula 2. Is exemplified.

Embedded image (However, M ²⁺ represents a divalent metal ion selected from the group consisting of magnesium, calcium and zinc, A ⁿ⁻ represents an n-valent anion, _X is 0 < _X <0.5, and m is 0 ≦. m ≦
Is 2. )

Embedded image (In the formula, X is an inorganic or organic anion,
n is the valence of the anion X, and m is a number of 3 or less. )

The transparency of the agricultural multilayer film varies depending on the type of the inorganic filler, and the closer the refractive index of the ethylene resin and the refractive index of the inorganic filler are, the less the decrease in transparency. Therefore, from the viewpoint of transparency. Chemical formula 1 and chemical formula 2
Hydrotalcites, lithium-aluminum composite hydroxide salts, aluminum silicates, aluminum hydroxides and the like are preferably used.

At least one layer other than the surface layer of the film, which faces the side opposite to the side of the object to be coated when it is spread, has an ethylene homopolymer, propylene containing ethylene as a main component, and 1-butene. 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, vinyl acetate copolymer, polypropylene homopolymer, polypropylene-based ethylene, 1-butene, 1-pentene, or 1-hexene copolymer may also be used, such as polypropylene resin polymer, preferably, ultra low density polyethylene having a density of 0.87~0.91g / cm ^3, low density polyethylene having a density of 0.91~0.93g / cm ^3, Those containing one or more synthetic resins selected from ethylene-vinyl acetate copolymers,
It is preferably used in terms of flexibility, transparency and price. Further, the layer functions as an adhesion layer between an antifogging layer and a heat retaining layer, an antifogging layer, a film strength improving layer, a flexibility improving layer, and a different polymer layer, for example, by adding a desired compounding agent. It can be a stacked layer or a laminated structure of these.

In producing the agricultural film according to the present invention, an antifogging agent, an
Various additives such as antifogging agents, antioxidants, ultraviolet absorbers, weather resistance improving agents such as light stabilizers, and slip agents may be added.

The agricultural film of the present invention is formed by using a known forming method such as a multi-layer inflation method, a multi-layer T-die method or lamination, and the thickness of the film varies depending on the place of use and the service life, etc. Generally, a thickness of about 0.05 to 0.20 mm is preferably used, but the present invention is not limited to this. Further, the thickness of the layers constituting the film including the surface layer referred to in the present invention is not particularly limited, but one layer is preferably 5 to 100 µ, more preferably 5 to 40 µ. The agricultural film of the present invention may be coated with a dustproof coating agent or an antifogging coating agent, if necessary, and dried to form a coating film on the surface.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

EXAMPLES The present invention will be described below in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

The dustproof property is maintained for 6 months in a field in Minamata City, Kumamoto Prefecture, while the surface layer containing high-density polyethylene having a density of 0.94 to 0.97 g / cm ³ is stretched so as to form the outer surface of the house. The light transmittance and haze value of the film before and after spreading were measured and used as a measure of dust resistance.

The band rubbing resistance (damage resistance) is measured on the side opposite to the side of the object to be coated when the film is stretched under the load of 300 g using a Gakushin type abrasion tester. , A haze H ₁ after a surface layer containing a high-density polyethylene having a density of 0.94 to 0.97 g / cm ³ was abraded 500 times with a flannel cloth and a haze H ₀ before the abrasion were measured to measure the haze before and after the abrasion. The scratch resistance represented by the difference ΔH = H ₁ −H ₂ was used as a measure of the band rubbing resistance.

The tear strength was measured according to JIS K-6781.

For transparency, the total light transmittance and the total haze value were measured using a haze meter in accordance with JIS K-6714 and used as a measure of transparency.

Examples 1 to 6 Density = 0.945 g / cm ³ , MFR = 0.45 g / 1
0 minutes, high density polyethylene with Mw / Mn = 4.7 (trade name: MZ9050 manufactured by Maruzen Polymer Co., Ltd.), melt flow rate as an elastic polymer (measurement temperature: 230 ° C., load: 2.16 kgf, JIS K -7210) = 0.91 g / 10 min styrene-ethylene-butylene copolymer (trade name: Dynalon 4600P manufactured by Japan Synthetic Rubber Co., Ltd.), having an average particle size of 0.4 μm as an inorganic filler. About synthetic hydrotalcite (Kyowa Chemical Industry Co., Ltd. product name; DHT-4A2),
The amount shown in Table 1 was used for each, and a hindered amine light stabilizer (Sanol LS770 manufactured by Ciba-Geigy Co., Ltd.)
Is used as a twin-screw extruder manufactured by Ikegai Tekko Co., Ltd., which uses 0.15% by weight and 4.85% by weight of low-density polyethylene powder having a density of 0.920 g / cm ³ (trade name PES120 manufactured by Nippon Unicar Co., Ltd.). And was molded into a composition A. next,
Density = 0.923 g / cm ³ , MFR = 2.4 g / 10
85% by weight of low density polyethylene (trade name: DFD0111 manufactured by Nippon Unicar Co., Ltd.), melt flow rate (measurement temperature 230 ° C., load 2.1) as an elastic polymer.
Measured according to JIS K-7210 at 6 kgf. ) =
3.2 g / 10 min ethylene-propylene elastic polymer (manufactured by Japan Synthetic Rubber Industry Co., Ltd .; trade name: EP02P), 10% by weight, antifogging agent (trade name, manufactured by Marubishi Yuka Kogyo Co., Ltd .;
PA5221K) in an amount of 1.5% by weight, and a fluorine-based fog preventive (trade name: Surflon 8405 manufactured by Asahi Glass Co., Ltd.) 1
% By weight, 0.15% by weight of hindered amine light stabilizer (Sanol LS770 manufactured by Ciba-Geigy Co., Ltd.), P
ES120 was used in an amount of 3.25% by weight and molded by a twin-screw extruder manufactured by Ikegai Tekko KK to obtain a composition B. The obtained composition was used under the conditions of a die temperature of 200 ° C. and an extrusion rate of 100 kg / hr using a two-layer T-die film forming machine capable of forming a two-kind two-layer film having a 90φ extruder and a 50φ extruder. Object B
A two-layer multilayer film was prepared by laminating a layer (thickness 20 μm) of the composition A on the layer (thickness 80 μm) of the composition A.
The obtained film was tested in the same manner as above with the layer comprising the composition A as the layer facing the side opposite to the object to be coated. The obtained results are shown in Table 1.

Example 7 In composition B, instead of DFDO111, MFR
= 2.0 g / 10 minutes, density = 0.94 g / cm ³ , vinyl acetate content = 15% by weight (trade name; NUC845, manufactured by Nippon Unicar Co., Ltd.)
The procedure described in Example 2 was repeated except that 0) was used. The obtained results are shown in Table 2.

Example 8 In composition B, instead of DFD0111, MZ9
The procedure described in Example 2 was used except that 050 was used. The obtained results are shown in Table 2.

Example 9 The procedure of Example 2 was repeated except that 55% by weight of DFD0111 and 30% by weight of MZ9050 were used in the composition B. The obtained results are shown in Table 2.

Example 10 In composition B, DHT-4 was used as the inorganic filler.
The same procedure as in Example 2 was carried out except that 5% by weight of A2 and 80% by weight of DFD0111 were used. The obtained results are shown in Table 2.

Example 11 The procedure of Example 2 was repeated, except that DFD0111 was used in Composition B in an amount of 70% by weight, EP02P was used in an amount of 20% by weight, and DHT-4A2 was used in an amount of 5% by weight. The obtained results are shown in Table 2.

Example 12 In the composition A, an aluminum / lithium composite hydroxide salt having an average particle size of 2 μm (trade name; Mizucarac, manufactured by Mizusawa Chemical Co., Ltd.) was used in place of DHT-4A2, and the composition B was used. At 80% by weight of DFD0111, DHT
-4A2 was carried out by the method described in Example 2 except that 5% by weight was used. The obtained results are shown in Table 2.

Example 13 In composition A, instead of MZ9050, density =
0.959 g / cm ³ , MFR = 13 g / 10 minutes, Mw
The same method as in Example 2 was carried out except that high density polyethylene (/Mn=4.0, manufactured by Chisso Corporation; trade name: M690) was used. The results obtained are shown in Table 3.

Example 14 In composition A, instead of MZ9050, density =
0.952 g / cm ³ , MFR = 0.35 g / 10 min,
High-density polyethylene with Mw / Mn = 15 (Chisso Corporation)
The same method as in Example 2 was used except that the product name: B743) was used. The results obtained are shown in Table 3.

Example 15 In composition A, instead of MZ9050, density =
0.950 g / cm ³ , MFR = 0.05 g / 10 minutes,
High-density polyethylene with Mw / Mn = 30 (Chisso Corporation)
The same method as in Example 2 was used except that the product name: GX600) was used. The results obtained are shown in Table 3.

Comparative Example 1 In composition A, 75% by weight of MZ9050 was used,
2 DHT-4A2 without using Dynaron 4600P
The same procedure as in Example 2 was carried out except that 0% by weight was used. The obtained results are shown in Table 4.

Comparative Example 2 In Composition A, 35% by weight of MZ9050 was used,
Using 40% by weight of Dynaron 4600P, DHT-4
The same procedure as in Example 2 was carried out except that 20% by weight of A2 was used. The obtained results are shown in Table 4.

Comparative Example 3 Example 2 except that in Composition A 75% by weight of MZ-9050 was used and DHT-4A2 was not used.
The same method was used. The obtained results are shown in Table 4.

Comparative Example 4 Except that in Composition A, 74.7% by weight of MZ-9050 and 0.3% by weight of DHT-4A2 were used.
It carried out by the same method as Example 2. The obtained results are shown in Table 4.

Comparative Example 5 The procedure of Example 2 was repeated, except that in Composition A, 45% by weight of MZ-9050 and 30% by weight of DHT-4A2 were used. The obtained results are shown in Table 4.

Comparative Example 6 In Composition A, DFD0 was used instead of MZ-9050.
The same procedure as in Example 3 was repeated except that 111 was used. Table 5 shows the obtained results.

COMPARATIVE EXAMPLE 7 In composition A, NUC3 was used in place of MZ-9050.
It was carried out in the same manner as in Example 3 except that 050 was used. Table 5 shows the obtained results.

Comparative Example 8 In composition A, DFD0 was used instead of MZ-9050.
It was carried out in the same manner as in Example 2 except that 111 was used. Table 5 shows the obtained results.

Comparative Example 9 In composition A, NUC3 was used instead of MZ-9050.
It was carried out in the same manner as in Example 2 except that 050 was used. Table 5 shows the obtained results.

Comparative Example 10 MZ9050 90% by weight, DHT-4A2 5% by weight, Sanol LS770 0.15% by weight, PES12
0 was used at 4.85% by weight and was molded by a twin-screw extruder manufactured by Ikegai Tekko KK to obtain a composition A. Using a T-die film-forming machine, the composition obtained was subjected to a die temperature of 200 ° C. and an extrusion rate of 100 k.
A single-layer film having a thickness of 100 μ was prepared under the condition of g / hr. About the obtained film, the arbitrary surface layer was made into the layer on the opposite side to the side which faces a coating target object, and the test was implemented in the said way. The obtained results are shown in Table 5.

[0048]

Industrial Applicability The agricultural polyolefin film of the present invention has a multi-layered structure, and at least the surface layer of the film facing the side opposite to the object side to be covered when the film is spread. An agricultural polyolefin-based film containing high-density polyethylene,
Further, by containing an elastic polymer and an inorganic filler in the surface layer, it has high dust resistance and band rub resistance, and is excellent in flexibility, tear strength, transparency, and has no problem in disposal. It has made it possible to provide a good agricultural film.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

[Table 3]

[0052]

[Table 4]

[0053]

[Table 5]

Claims (5)

[Claims] 1. An agricultural polyolefin-based film having a multilayer structure of two or more layers, wherein the surface layer of the film facing at least the side opposite to the object side to be covered when the film is spread. , Density 0.94 to 0.97
A polyolefin-based multilayer film for agriculture, which is a surface layer of a film composed of a composition containing g / cm ³ of high-density polyethylene as a main component. 2. A high-density polyethylene having a density of 0.94 to 0.97 g / cm ³ has a melt flow rate (measurement temperature: 190 ° C., load: 2.16 kgf, JIS).
(According to K-7210) 0.1 to 5.0 g / 10 minutes, ratio Mw / Mn of weight average molecular weight Mw and number average molecular weight Mn
Is in the range of 3 to 10, wherein the agricultural polyolefin-based multilayer film according to claim 1. 3. The agriculture according to claim 1, wherein the composition containing high-density polyethylene as a main component contains 5 to 30% by weight of the elastic polymer with respect to the composition. Polyolefin-based multilayer film for use. 4. The agricultural polyolefin according to any one of claims 1 to 3, wherein the composition containing high-density polyethylene as a main component contains 0.5 to 20% by weight of an inorganic filler with respect to the composition. Series multilayer film. 5. At least one film layer other than the surface layer of the film facing the side of the object to be covered when expanded has a density of 0.87-0.91 g / cm.
³ ultra low density polyethylene, density 0.91 to 0.93g
/ Cm ³ low density polyethylene, or a composition comprising one or more kinds of synthetic resin selected from ethylene-vinyl acetate copolymer, the polyolefin multi-layer for agricultural use according to any one of claims 1 to 4. the film.