JPH09302158A - Film for protected horticulture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a film for protected horticulture having excellent heat retaining property without damaging various properties such as transparency and useful as a covering materiel of a house, etc., by molding an olefinic resin composition comprising a specific ratio of an olefinic resin and a specific metal compound. SOLUTION: This film for protected horticulture is obtained by molding an olefinic resin composition comprising 100 pts.ws. of an olefinic resin such as an ethylene-vinyl acetate copolymer resin containing <=25wt.% of vinyl acetate, a low density polyethylene having 0.910.94 density and an ethylene-acrylic copolymer resin and 1-20 pts.-wt. of a metal compound expressed by formula 0<(x)<0.5; 0.5<=(a+b+c)<1; 0<(a)<1; 0<(b)<1; 0<=(c)<1; M1 is Mg<2> ; M2 and M3 are each Zn<2+> , Ba<2+> , Ca<2+> , Cd<2+> or Pb<2+> ; Y is an (n)-valent anion; 0<=(m)<=2}. At least one or more than two kinds of compound selected from formula II may be combinedly used as the metal compound of the formula I.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a horticultural film made of an olefin resin.

[0002]

2. Description of the Related Art Conventionally, as a covering material used in greenhouse horticulture, polyvinyl chloride resin such as polyvinyl chloride, polyethylene, ethylene-vinyl acetate copolymer resin, ethylene
A transparent film made of an olefin resin such as an acrylic copolymer resin is used. In particular, a film made of a vinyl chloride-based resin is widely used as a covering material for the above-mentioned greenhouse horticulture because of its excellent transparency and heat retention.

On the other hand, a film made of an olefin-based resin is inferior to the above-mentioned vinyl chloride-based resin in heat retention. Therefore, conventionally, a film has been proposed in which an inorganic fine powder that absorbs in the infrared region, such as silica and hydrotalcite, is added to an olefin resin.

[0004]

As described above, by adding an inorganic fine powder such as silica or hydrotalcite which absorbs in the infrared region to the olefin resin, the heat insulation was secured to some extent. But it wasn't enough yet. Further, when the inorganic fine powder as described above is added, various physical properties such as transparency of the film may be impaired.

The present inventor has conducted extensive studies to solve the above problems, and as a result, by adding a specific amount of a specific metal compound, various physical properties such as transparency were not impaired.
They have found that an olefin resin film having extremely excellent heat retention can be obtained, and have completed the present invention.

[0006]

The facility horticultural film of the present invention, which has been made to solve the above problems, has 1 to 20 parts by weight of the metal compound shown in Chemical formula 2 added to 100 parts by weight of the olefin resin. It is formed by molding the olefin resin composition.

Embedded image (However, 0 <x <0.5, 0.5 ≦ a + b + c <1, 0
<A <1, 0 <b <1, 0 ≦ c <1, M ₁ is Mg ²⁺ , M
₂ , M ₃ is a metal ion selected from Zn ²⁺ , Ba ²⁺ , Ca ²⁺ , Cd ²⁺ and Pb ²⁺ , Y is an n-valent anion, 0 ≦ m ≦
2. )

The horticultural film of the present invention preferably has an olefin-based resin layer containing no metal compound as described above on the inner side when the film is spread on a house or the like.

The olefin resin used in the greenhouse horticultural film of the present invention includes polyethylene such as low-density polyethylene, linear low-density polyethylene and high-density polyethylene, polypropylene, ethylene-propylene copolymer resin, ethylene-acetic acid. Vinyl copolymer resin, ethylene-
Acrylic copolymer resins or mixtures of these resins can be used as long as they are conventionally used, but in particular, polyethylene, ethylene-vinyl acetate copolymer resins, ethylene-acrylic resins A copolymer resin is preferred. As the above-mentioned polyethylene, those having a low density of about 0.91 to 0.94 are suitable. As the ethylene-vinyl acetate copolymer resin, a vinyl acetate content of 25% by weight or less, more preferably vinyl acetate Those having a content of 15% by weight or less are preferred. In addition, as the ethylene-acrylic copolymer resin, an ethylene-methyl acrylate copolymer resin, an ethylene-ethyl acrylate copolymer resin, an ethylene-methyl methacrylate copolymer resin, or the like can be used. In particular, when heat retention is required, it is preferable to select an ethylene-vinyl acetate copolymer resin as the olefin resin.

As the metal compound added to the above-mentioned olefin resin, one kind or a mixture of two or more kinds selected from those represented by the general formula shown in the following chemical formula 3 can be used.

Embedded image (However, 0 <x <0.5, 0.5 ≦ a + b + c <1, 0
<A <1, 0 <b <1, 0 ≦ c <1, M ₁ is Mg ²⁺ , M
₂ , M ₃ is a metal ion selected from Zn ²⁺ , Ba ²⁺ , Ca ²⁺ , Cd ²⁺ and Pb ²⁺ , Y is an n-valent anion, 0 ≦ m ≦
2. )

Examples of the anion represented by Y include those represented by Chemical formula 4.

Embedded image

Further, as a specific metal compound,
The following are mentioned.

Embedded image

Regarding the particle size of the above-mentioned metal compound, it is preferable that the average secondary particle size is 5 μm or less, but the present invention is not limited to this. Further, the above metal compound is
Paraffin, higher fatty acids, for the purpose of improving dispersibility,
It may be surface-treated with a surface-treating agent such as alkali metal salts of higher fatty acids, higher alcohols, polyhydric alcohols and coupling agents.

The addition amount of the metal compound is 1 to 20 parts by weight, preferably 2 to 100 parts by weight of the olefin resin.
15 parts by weight. When the addition amount of the metal compound is less than 1 part by weight with respect to 100 parts by weight of the olefin resin, the obtained film has insufficient heat retention, and the addition amount of the metal compound is 100 parts by weight of the olefin resin. If it exceeds 20 parts by weight, the transparency of the obtained film is impaired.

In addition to the above metal compounds, the olefin resin composition for forming the facility gardening film of the present invention contains
Conventionally used for facility horticulture film made of olefin resin, antistatic agent, antifogging agent, antifog agent, ultraviolet absorber, light stabilizer, antioxidant, antiblocking agent, lubricant, filler, Various additives such as colorants can also be added.

The olefin resin composition obtained by mixing the above-mentioned olefin resin with a metal compound and various additives to be added as required in a predetermined amount is known by a calendar method, an extrusion method, an inflation method or the like. It is formed into a film by means. The thickness of the film is 0.01 to 0.3, which is conventionally generally used as a greenhouse horticultural film.
mm, more preferably about 0.05 to 0.2 mm.

The facility horticultural film of the present invention is not limited to a single-layer film, but may be a laminated film composed of a plurality of layers of the same composition or different compositions. It is desirable to form an olefin resin layer that does not contain the above metal compound on the surface to be formed.
When the film for greenhouse horticulture of the present invention is a laminated film, sufficient heat insulation cannot be obtained if the thickness of the layer containing the metal compound is too small, so that the thickness of the layer containing the metal compound Is 0.01 mm or more, more preferably 0.0
It is desirable to set it to 5 mm or more. In addition, as means for obtaining the above-mentioned laminated film, known means such as a co-extrusion method, an extrusion lamination method, a co-extrusion inflation method can be adopted, but from the viewpoint of workability and cost, the co-extrusion inflation method is particularly preferred. It is suitable.

The olefin-based resin forming the olefin-based resin layer containing no metal compound, which is formed on the inner surface when expanded in a house or the like, is polyethylene such as low-density polyethylene, linear low-density polyethylene, or high-density polyethylene, Polypropylene, ethylene-propylene copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-
An acrylic copolymer resin or a mixture of these resins can be used, but an ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 15% by weight or less is particularly preferable. Other resins such as low-density polyethylene are inferior in terms of transparency and anti-fog properties as compared with ethylene-vinyl acetate copolymer resin, and even if the same ethylene-vinyl acetate copolymer resin is used, the vinyl acetate content is low. More than 15% by weight of ethylene
When formed of a vinyl acetate copolymer resin, the contact surface with the framework such as a house is sticky, and the workability of spreading the film on the house or the like is extremely poor.

The reason why the olefin resin layer not containing the above metal compound is selected as the olefin resin layer formed on the inner surface when it is spread on a house or the like is that the antifog agent is added together with the above metal compound. This is because if added, the antifogging performance may be impaired.

On the other hand, the olefin-based resin forming the olefin-based resin layer formed on the outer surface when it is spread on a house or the like is not particularly limited, but the strength and dustproofness of low density polyethylene or the like is not limited. It is preferable to use excellent ones.

[0020]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to specific examples.

[Examples 1 to 6 and Comparative Examples 1 to 4] The olefin resin compositions having the formulations shown in Table 1 and Table 2 were prepared.
Three-layer inflation molding device (Plastic Co., outer layer
50 mm extruder for each of the middle layer and the inner layer is used, and the molding temperature is 1
A film having a thickness of 0.1 mm and a folding diameter of 50 cm (the width of the film when opened was 100 cm) was obtained at 60 ° C., a blow ratio of 2.0, and a take-up speed of 15 m / min. The obtained film is spread on a mini house with a height of 1 m to retain heat, spread workability,
The transparency was evaluated according to the following criteria.

<Heat-retaining property> December 1, 1995-199
The temperature inside the house and the air temperature at 6:00 am on December 10, 2013 were measured, the average temperature difference was obtained, and the evaluation was made in five steps, with "5" being optimal. <Workability of spreading> The workability of spreading to the mini-house was evaluated on a scale of five. The evaluation was performed using the following as a guide. 5. No film stickiness at all, extremely good workability 4. Film hardly sticky, good workability 3. Little film stickiness, but no hindrance to work 2. There is a sticky feeling of the film, which hinders the work. 1. The sticky feeling of the film is large and the work is difficult. The evaluation was performed using the following as a guide. 5. Very little turbidity and excellent transparency 4. Very slight turbidity but good transparency 3. Somewhat cloudy 2. Poor transparency due to cloudiness 1. Extremely poor

[0023]

[Table 1]

[0024]

[Table 2]

As is clear from the above results, the facility horticultural film of the present invention using a specific metal compound is more transparent than the film using hydrotalcites or silica which has been generally used conventionally. It has excellent heat resistance and heat retention. In addition, as in Example 6, the vinyl acetate content of 2 is provided on the inner surface of the house when the house is expanded.
When a layer composed of 5% by weight of ethylene-vinyl acetate copolymer resin is formed, the workability in spreading is inferior, while as in Examples 2 to 5, ethylene with a vinyl acetate content of 10% by weight is used. When a layer made of a vinyl acetate copolymer resin is formed, it is excellent in transparency, heat retention and spreading workability.

[0026]

As described above in detail, the greenhouse horticultural film of the present invention has excellent properties without impairing various physical properties such as transparency by adding a specific metal compound to an olefin resin. It has heat retention. Therefore,
When the film for greenhouse horticulture of the present invention is used as a covering material for facilities such as a house and a tunnel, an environment more suitable for cultivation of various crops can be provided.

Claims (6)

[Claims] Claims: 1. An amount of olefin resin is 100 parts by weight.
A greenhouse horticultural film obtained by molding an olefin resin composition obtained by adding 1 to 20 parts by weight of a metal compound represented by the general formula shown in Chemical Formula 1. Embedded image (However, 0 <x <0.5, 0.5 ≦ a + b + c <1, 0
<A <1, 0 <b <1, 0 ≦ c <1, M ₁ is Mg ²⁺ , M
₂ , M ₃ is a metal ion selected from Zn ²⁺ , Ba ²⁺ , Ca ²⁺ , Cd ²⁺ and Pb ²⁺ , Y is an n-valent anion, 0 ≦ m ≦
2. ) 2. The institutional horticultural film according to claim 1, wherein the olefin resin is an ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 25% by weight or less. 3. The olefin resin having a density of 0.91 to 0.91.
2. The greenhouse horticultural film according to claim 1, wherein the film is a low-density polyethylene of 0.94. 4. The film for greenhouse horticulture according to claim 1, wherein the olefin resin is an ethylene-acrylic copolymer resin. 5. An olefin-based resin layer containing no metal compound represented by the general formula shown in Chemical Formula 1 is formed on a surface which becomes inside when the film is stretched.
The horticultural film according to the item. 6. An olefin-based resin constituting an olefin-based resin layer containing no metal compound represented by the general formula shown in Chemical Formula 1 is an ethylene-based resin having a vinyl acetate content of 15% by weight or less.
The greenhouse horticultural film according to claim 5, which is a vinyl acetate copolymer resin.