JPH10101852A - Film for protected horticulture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a film having excellent warmth-keeping property and suitable as coating materials for facilities such as green houses and tunnels without deteriorating various properties such as transparency by forming an olefin resin composition, composed of a specific metal compound in a specific amount, into film. SOLUTION: This film is obtained by forming an olefin resin composition, which is prepared by compounding 100 pts.wt. of an olefin resin such as an ethylene-vinyl acetate copolymer resin having a vinyl acetate-content of <=25wt.%, a low density polyethylene having a density of 0.91-0.94 or an ethylene-acrylic copolymer resin with 1-20 pts.wt. of a metal compound of the formula [(x)+4(y)=2(z);O<(a)<1; 0<b1 <=3; 0<=b2 $3; 0<=(c)<=3; 0<=$(n)$3 (y) is an acidl, into film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention 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, or a laminated film of these 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, in order to improve the heat retention of a film made of an olefin resin, it has been proposed to add an inorganic fine powder such as silica or hydrotalcite that absorbs in the infrared region to the 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.

On the other hand, the applicant of the present invention has filed Japanese Patent Application No. 8-142.
No. 226 proposes an olefin-based resin film to which a specific amount of a metal compound shown in Chemical formula 2 is added and which has extremely excellent heat retention without impairing various properties such as transparency.

Embedded image However, as a result of further research, by using a specific metal compound different from the metal compound shown in Chemical formula 2, it is possible to reduce the physical properties such as transparency as in the case of using the metal compound shown in Chemical formula 2. Further, they have found that an olefin-based resin film having a heat retention equal to or higher than that using the metal compound shown in Chemical formula 2 can be obtained, and have completed the present invention.

[0006]

In order to solve the above-mentioned problems, the facility horticulture film of the present invention is characterized in that 1 to 20 parts by weight of a metal compound represented by Chemical Formula 3 is added to 100 parts by weight of an olefin resin. Formed by molding the olefin-based resin composition thus obtained.

Embedded image

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 to be added to the olefin resin, one or a mixture of two or more selected from compounds represented by the following general formula (4) can be used.

Embedded image

In the above chemical formula 4, the acid represented by Y is
HCl, HBr, HI, HNO ₃ , H ₂ SO ₃ , H ₂ S
It is at least one selected from O ₄ , H ₂ CO ₃ , H ₃ BO ₃ , CH ₃ COOH and the like, but H ₂ CO ₃ is particularly preferable. Further, the acid represented by P ₂ O ₅ and Y and H ₂ O in the above chemical formula 4 are not essential components, and even if they do not contain these, they can be suitably used.

The above-mentioned metal compound is generally in the form of powder or granules, and particularly preferably those having an average secondary particle diameter of 5 μm or less and a refractive index of about 1.45 to 1.55, but are not limited thereto. Not something. Further, the above metal compound, for the purpose of improving dispersibility, paraffin, higher fatty acid, alkali metal salts of higher fatty acid, higher alcohol,
It may be surface-treated with a surface treatment agent such as a polyhydric alcohol or a coupling agent.

The addition amount of the metal compound is 1 to 20 parts by weight, preferably 2 to 20 parts by weight, based on 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.

The olefin-based resin composition for forming the greenhouse horticultural film of the present invention contains, in addition to the above-mentioned metal compounds,
Antistatic agents, antifogging agents, antifog agents, ultraviolet absorbers, light stabilizers, antioxidants, antiblocking agents, lubricants, coloring agents, etc. conventionally used in horticultural films made of olefinic resins Can be added. Further, as long as the transparency of the obtained film is not impaired, magnesium carbonate, magnesium silicate,
Silicon oxide, aluminum oxide, aluminum hydroxide, magnesium hydroxide, hydrotalcites and the like may be added.

Examples of the antifogging agent include sorbitan fatty acid ester, sorbitol fatty acid ester, glycerin fatty acid ester, diglycerin fatty acid ester, sorbitan fatty acid / dibasic acid ester, sorbitol fatty acid / dibasic acid ester, diglycerin fatty acid / dibasic acid ester Esters of polyhydric alcohols and fatty acids such as acid esters, esters of polyhydric alcohols and fatty acids and dibasic acids, or ethylene oxide, propylene oxide,
Examples thereof include compounds to which an alkylene oxide such as butylene oxide is added, and specifically, sorbitan palmitate, sorbitan stearate, sorbitan stearate / ethylene oxide 2 mol adduct, sorbitan stearate / propylene oxide 3 mol adduct ,
Sorbitol stearate, sorbitol stearate / ethylene oxide 3 mol adduct, diglycerin palmitate / ethylene oxide 2 mol adduct, sorbitan stearate adipate / ethylene oxide 2 mol adduct, sorbitol stearate adipate / ethylene oxide 2 mol adduct And diglycerin palmitate sebacate / propylene oxide 3 mol adduct, sorbitol palmitate adipate / ethylene oxide 3 mol adduct and the like. The above drip-proofing agents can be used alone or in combination of two or more. The amount of the drip-proofing agent is about 0.5 to 6.0 parts by weight based on 100 parts by weight of the olefin resin.

As the above-mentioned antifog agent, a fluorine-containing compound having a fluorine-containing group and at least one of a hydroxyl group and an alkylene oxide group in one molecule can be used. As the fluorinated group, a perfluoroalkyl group [C _n F _{2n + 1}
Group), a perfluoroalkoxy group [C _n F _{2n + 1} O group],
A polyfluoroalkyl group [H _m C _n F _{2n + 1-m} group], a perfluoroalkenyl group [C _n F _2n-1 group], a polyfluoroalkenyl group [H _m C _n F _2n-1-m group], A perfluoroalkylene group [C _n F _2n group] (where m is an integer of 1 to 3 and n is an integer of 3 to 20), and the alkylene oxide group is (C ₂ H ₄ O) _n , (C ₃ H ₆ O) _n
(However, n in the formula is an integer of 1 to 30).
Specific examples include those shown in Chemical formulas (1) to (13), but are not limited thereto. The addition amount of the antifog is 0.01 to 1.0 part by weight, more preferably 0.05 to 1.0 part by weight, based on 100 parts by weight of the olefin resin.
0.5 part by weight.

Embedded image

As the above-mentioned ultraviolet absorber, a benzophenone-based, benzotriazole-based, salicylic acid ester-based, cyanoacrylate-based ultraviolet absorber and the like can be used. The above-mentioned ultraviolet absorbers can be used alone or in combination of two or more.

The above light stabilizers include 2,2,6,6
Hindered amine light stabilizers having a tetramethylpiperidine unit can be used. The hindered amine light stabilizer preferably has a molecular weight of about 800 to 2,000. The amount of the hindered amine light stabilizer added is 0.1 to 100 parts by weight of the olefin resin.
It is about 0.01 to 0.3 parts by weight.

As the light stabilizer, besides the above-mentioned commonly used hindered amine light stabilizer, for example,
Ethylene copolymers having a hindered amine compound in the side chain obtained by copolymerizing ethylene and a cyclic aminovinyl compound can also be used. When such a light stabilizer is used, the addition amount is about 0.05 to 5.0 parts by weight based on 100 parts by weight of the olefin resin.

An olefin resin composition obtained by mixing a predetermined amount of the above-mentioned olefin resin with a metal compound and various additives to be added as required is obtained by a known method such as a calendering method, an extrusion method and an inflation method. 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 film for greenhouse horticulture of the present invention is not limited to a film having a single layer, but may be a laminated film having a plurality of layers of the same composition or different compositions. It is desirable to form an olefin-based resin layer not containing the metal compound on the surface.
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 resin forming the olefin resin layer not containing the metal compound formed on the inner surface when expanded on a house or the like includes polyethylene such as low-density polyethylene, linear low-density polyethylene, and 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-based resin layer containing no metal compound was selected as the olefin-based resin layer formed on the inner side when the material was spread on a house or the like is that an anti-fogging agent was used together with the metal compound. This is because if added, the anti-fog performance may be impaired.

On the other hand, the olefin-based resin constituting the olefin-based resin layer formed on the outer side when expanded on a house or the like is not particularly limited. It is preferable to use an excellent one.

[0024]

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

Examples 1 to 9 and Comparative Examples 1 to 4 An olefin resin composition having the composition shown in Tables 1 and 2 was
Using a three-layer inflation molding machine (manufactured by Placo), molding temperature 160 ° C., blow ratio 2.0, take-off speed 15
At m / min, a film having a thickness of 0.1 mm and a folded diameter of 50 cm (film width when opened: 100 cm) was obtained. The obtained film was spread on a mini-house having a height of 1 m, and evaluated for heat retention, spreading workability, and transparency according to the following criteria.

<Heat Insulation> December 1, 1995 to 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. <Expansion workability> The workability of extension to the mini-house was evaluated on a five-point scale. 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

[0027]

[Table 1-1]

[0028]

[Table 1-2]

[0029]

[Table 2]

[0030]

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 2. The greenhouse 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.