阅读说明：本技术 农业用膜、农业用膜形成用树脂组合物及使用该农业用膜的植物的培育方法 (Agricultural film, resin composition for forming agricultural film, and method for growing plant using agricultural film ) 是由 绫部敬士 宫村大地 于 2020-06-22 设计创作，主要内容包括：本发明的农业用膜用于硫磺熏蒸或硫磺施撒,其具有耐候性层,该耐候性层包含给定的受阻胺系光稳定剂、给定的苯甲酸酯化合物、给定的紫外线吸收剂、及热塑性树脂,在将受阻胺系光稳定剂的含量记为X、将苯甲酸酯化合物的含量记为Y时,X、Y满足1.5/8.5≤X/Y≤9.5/0.5。(The agricultural film of the present invention is used for sulfur fumigation or sulfur application, and has a weather-resistant layer containing a given hindered amine-based light stabilizer, a given benzoate compound, a given ultraviolet absorber, and a thermoplastic resin, wherein X, Y satisfies 1.5/8.5. ltoreq. X/Y. ltoreq.9.5/0.5 when the content of the hindered amine-based light stabilizer is X and the content of the benzoate compound is Y.)

1. An agricultural film for use in sulfur fumigation or sulfur application, the agricultural film having a weather-resistant layer,

the weatherable layer comprises:

a hindered amine-based light stabilizer which is one or more selected from the group consisting of a compound represented by the following general formula (A1) and a compound represented by the following general formula (A2);

a benzoate compound selected from one or two or more compounds represented by the following general formula (B);

an ultraviolet absorber containing one or more selected from benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers and triazine-based ultraviolet absorbers; and

a thermoplastic resin,

the weatherable layer is configured to: x, Y satisfies the condition that X/Y is not less than 1.5/8.5 and not more than 9.5/0.5 when the content of the hindered amine light stabilizer in terms of mass is represented by X and the content of the benzoate compound in terms of mass is represented by Y,

in the above general formula (A1), R¹And R²The same or different, each independently represents an alkyl group having 1 to 8 carbon atoms or a 1- (n-propoxy) -2,2,6, 6-tetramethylpiperidin-4-yl group; in the general formula (a1), n is an integer of 0 or more;

in the above general formula (A2), R³And R⁴The same or different, each independently represents an alkyl group having 1 to 20 carbon atoms,

in the above general formula (B), R⁵And R⁶The same or different, each independently represents an alkyl group having 1 to 8 carbon atoms; r⁷Represents an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an alkylaryl group having 7 to 30 carbon atoms.

2. The agricultural film of claim 1, wherein,

the hindered amine light stabilizer comprises one or more selected from the group consisting of compound A1, compound A2, and compound A3,

3. the agricultural film of claim 1 or 2, wherein,

the benzoate compound represented by the general formula (B) includes at least one of the compound B1 or the compound B2,

4. the agricultural film of any one of claims 1 to 3, wherein,

the content of the ultraviolet absorber is 0.01 mass% or more and 1 mass% or less with respect to 100 mass% of the thermoplastic resin.

5. The agricultural film of any one of claims 1 to 4, wherein,

the total content of the hindered amine light stabilizer and the benzoate compound is 0.01 mass% or more and 10 mass% or less with respect to 100 mass% of the thermoplastic resin.

6. The agricultural film of any one of claims 1 to 5, wherein,

the agricultural film has a multilayer structure comprising the weather-resistant layer and other layers containing a thermoplastic resin.

7. The agricultural film of any one of claims 1 to 6, wherein,

the thermoplastic resin includes linear low-density polyethylene or low-density polyethylene.

8. The agricultural film of any one of claims 1 to 7, wherein,

the agricultural film is used to form a greenhouse.

9. An agricultural film-forming resin composition for forming an agricultural film according to any one of claims 1 to 8, comprising:

the hindered amine light stabilizer is one or more selected from the group consisting of a compound represented by the general formula (A1) and a compound represented by the general formula (A2);

a benzoate compound selected from one or more compounds represented by the general formula (B);

an ultraviolet absorber containing one or more members selected from the group consisting of benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and triazine-based ultraviolet absorbers; and

a thermoplastic resin,

when the content of the hindered amine light stabilizer in terms of mass is represented by X and the content of the benzoate compound in terms of mass is represented by Y, X, Y satisfies the condition that X/Y is not less than 1.5/8.5 and not more than 9.5/0.5.

10. A method of growing a plant, comprising:

disposing the agricultural film according to any one of claims 1 to 8 in a greenhouse;

disposing plants in the greenhouse; and

and (3) carrying out sulfur fumigation in the greenhouse.

Technical Field

The present invention relates to an agricultural film, a resin composition for forming an agricultural film, and a method for growing plants using the agricultural film.

Background

Various developments have been made to agricultural films. As such a technique, for example, a technique described in patent document 1 is known. Patent document 1 describes an agricultural film containing a hindered amine light stabilizer (claim 4 of patent document 1, etc.).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2015-198579

Disclosure of Invention

Problems to be solved by the invention

However, the present inventors have found, as a result of their studies, that the agricultural film described in patent document 1 has room for improvement in long-term weather resistance and transparency.

Means for solving the problems

As a method for improving weather resistance of an agricultural film, a method using a hindered amine light stabilizer and an ultraviolet absorber is generally known.

Such agricultural films are used for various purposes, and examples thereof include a sulfur fumigation method and a sulfur application method. One of the methods for growing plants (crops) is a sulfur fumigation method of fumigating sulfur in a plastic greenhouse or a method of spraying a chemical liquid containing sulfur such as a sulfur fluidizing agent, and the purpose of the method is to prevent diseases of plants.

However, sulfur contained in fumigation or chemical solutions may reduce the long-term weather resistance of agricultural films containing hindered amine-based light stabilizers and ultraviolet absorbers.

The detailed mechanism is not clear, but it is considered that the sulfur adhering to or migrating into the agricultural film is oxidized to be acidified and forms a salt with the hindered amine-based light stabilizer, and the function of the light stabilizer is deactivated, so that the weather resistance cannot be maintained.

In addition, such a decrease in weather resistance is observed remarkably when sulfur fumigation is performed in a greenhouse.

The present inventors have made intensive studies based on these circumstances, and as a result, have found that a long-term weather resistance deterioration can be suppressed in an agricultural film having a layer containing a hindered amine light stabilizer and a benzoate compound as a synergist thereof in combination.

The detailed mechanism is not clear, but it is considered that a given benzoate compound inhibits the formation of a salt between sulfur and a given hindered amine-based light stabilizer, and thus inhibits the uptake and absorption of sulfur into an agricultural film.

On the other hand, if the content ratio of the benzoate compound is increased, the transparency of the agricultural film may be decreased.

The present inventors have conducted intensive studies based on the findings obtained and as a result, have found that the long-term weather resistance and transparency of an agricultural film can be improved by appropriately controlling the content ratio of a hindered amine light stabilizer to a benzoate compound in the agricultural film.

As is clear from the above, the long-term weather resistance when used for sulfur fumigation or sulfur application is improved by setting the content ratio of the hindered amine light stabilizer to the benzoate compound to a predetermined value or more, and the transparency is improved by setting the content ratio to a predetermined value or less, thereby completing the present invention.

According to the present invention, there is provided an agricultural film for sulfur fumigation or sulfur application, the agricultural film having a weather-resistant layer comprising:

a hindered amine-based light stabilizer which is one or more selected from the group consisting of a compound represented by the following general formula (A1) and a compound represented by the following general formula (A2);

a benzoate compound selected from one or two or more compounds represented by the following general formula (B);

an ultraviolet absorber containing one or more members selected from the group consisting of benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and triazine-based ultraviolet absorbers; and

a thermoplastic resin,

wherein the weather-resistant layer is configured so that X, Y satisfies 1.5/8.5. ltoreq. X/Y. ltoreq.9.5/0.5 when the content of the hindered amine light stabilizer in terms of mass is represented by X and the content of the benzoate compound in terms of mass is represented by Y,

[ chemical formula 1]

In the above general formula (A1), R¹And R²The same or different, each independently represents an alkyl group having 1 to 8 carbon atoms or a 1- (n-propoxy) -2,2,6, 6-tetramethylpiperidin-4-yl group; in the general formula (A1), n is an integer of 0 or more;

[ chemical formula 2]

In the above general formula (A2), R³And R⁴The same or different, each independently represent a carbon atomA number of 1 to 20 alkyl groups;

[ chemical formula 3]

In the above general formula (B), R⁵And R⁶The same or different, each independently represents an alkyl group having 1 to 8 carbon atoms, R⁷Represents an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an alkylaryl group having 7 to 30 carbon atoms.

Further, according to the present invention, there is provided an agricultural film-forming resin composition for forming the above agricultural film.

Further, according to the present invention, there is provided a method for cultivating a plant, comprising:

disposing the agricultural film in a greenhouse;

disposing plants in the greenhouse; and

and (3) carrying out sulfur fumigation in the greenhouse.

Effects of the invention

The present invention provides an agricultural film having excellent long-term weather resistance and transparency, a resin composition for forming an agricultural film for forming the film, and a method for growing plants using the agricultural film.

Drawings

Fig. 1 is a sectional view showing an example of the structure of the agricultural film of the present embodiment.

Fig. 2 is a diagram for explaining an outline of a fumigation apparatus for sulfur fumigation treatment.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof is omitted as appropriate. The figure is a schematic view, and does not match the actual size ratio.

In the present embodiment, the directions of the front, rear, left, right, and upper and lower sides are defined and described as shown in the drawings. However, this is defined for convenience in order to simply explain the relative relationship of the constituent elements. Therefore, the direction of the product to which the present invention is applied in manufacturing and use is not limited.

Next, the agricultural film of the present embodiment will be briefly described.

The agricultural film of the present embodiment includes a hindered amine light stabilizer, a benzoate compound, an ultraviolet absorber, and a thermoplastic resin.

The hindered amine light stabilizer contains one or more selected from the group consisting of a compound represented by the following general formula (A1) and a compound represented by the following general formula (A2).

The benzoate compound contains one or more compounds selected from the group consisting of compounds represented by the following general formula (B).

The ultraviolet absorber contains one or more selected from benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, and triazine ultraviolet absorbers.

The agricultural film containing such a component has a weather-resistant layer, and the weather-resistant layer is configured so that X, Y satisfies 1.5/8.5. ltoreq. X/Y. ltoreq.9.5/0.5 when the content of the hindered amine light stabilizer in terms of mass is represented by X and the content of the benzoate compound in terms of mass is represented by Y.

According to the findings of the present inventors, it has been found that the use of a given hindered amine light stabilizer and a given ultraviolet absorber can improve the weather resistance; when the content ratio of the given hindered amine light stabilizer to the given benzoate compound is not less than the lower limit value, the long-term weather resistance can be improved even when the composition is used for sulfur fumigation or sulfur application; then, by setting the content ratio to the upper limit or less, the transparency can be improved.

According to the present embodiment, an agricultural film having excellent transparency can be realized while suppressing a decrease in long-term weather resistance even when used for sulfur fumigation or sulfur application.

The agricultural film of the present embodiment will be described in detail below.

The agricultural film has a weather-resistant layer containing a hindered amine light stabilizer, a benzoate compound, an ultraviolet absorber, and a thermoplastic resin.

The weather-resistant layer contains one or more substances selected from the group consisting of a compound represented by the following general formula (A1) and a compound represented by the following general formula (A2).

[ chemical formula 4]

In the above general formula (A1), R¹And R²The same or different, each independently represents an alkyl group having 1 to 8 carbon atoms or a 1- (n-propoxy) -2,2,6, 6-tetramethylpiperidin-4-yl group.

In the general formula (a1), n is an integer of 0 or more. The value of n is, for example, 0 to 10, and may be 0 to 6. The hindered amine-based light stabilizer may contain one or more compounds represented by the general formula (a1) in which n is different in value. As R¹And R²Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a tert-pentyl group, a hexyl group, a heptyl group, an octyl group, a1, 1,3, 3-tetramethylbutyl group and the like. Among them, propyl, isopropyl, butyl, sec-butyl, and tert-butyl are preferable, and butyl is particularly preferable.

[ chemical formula 5]

In the above general formula (A2), R³And R⁴The alkyl groups are the same or different and each independently represents an alkyl group having 1 to 20 carbon atoms. As R³And R⁴Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Among them, preferred are octyl, 2-ethylhexyl, nonyl, decyl, undecyl and dodecylAlkyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl, more preferably octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, and tetradecyl, and particularly preferably undecyl.

One example of the hindered amine-based light stabilizer may include one or more selected from the group consisting of the compound a1, the compound a2, and the compound A3 described below.

[ chemical formula 6]

In the compound a1, n is an integer of 0 or more. The value of n may be 0 to 6, for example, as long as it is 0 to 10. The hindered amine-based light stabilizer may contain one or more compounds a1 different in n value.

[ chemical formula 7]

[ chemical formula 8]

In the compound a3, n is an integer of 0 or more. The value of n is, for example, 0 to 10, and may be 0 to 6. The hindered amine-based light stabilizer may contain one or more compounds a3 different in n value.

The weather-resistant layer contains one or more benzoate compounds selected from the compounds represented by the following general formula (B) as a synergist for the hindered amine light stabilizer.

[ chemical formula 9]

The above-mentioned all-purpose cleanerIn the formula (B), R⁵And R⁶The same or different, each independently represents an alkyl group having 1 to 8 carbon atoms, R⁷Represents an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an alkylaryl group having 7 to 30 carbon atoms.

As R⁵And R⁶Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a tert-pentyl group, a hexyl group, a heptyl group, an octyl group, a1, 1,3, 3-tetramethylbutyl group and the like. Among them, isopropyl group, sec-butyl group, tert-amyl group, and 1,1,3, 3-tetramethylbutyl group are preferable, and tert-butyl group and tert-amyl group are more preferable.

As R⁷Examples of the alkyl group having 1 to 30 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Among them, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl are preferable, and dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl are more preferable.

As R⁷Examples of the aryl group of (2) include phenyl and the like.

As R⁷Examples of the alkylaryl group of (2) include a methylphenyl group, a butylphenyl group, a2, 4-di-tert-pentylphenyl group, a2, 4-dicumylphenyl group, and a2, 4-di-tert-butyl-5-methylphenyl group. Among these, 2, 4-di-t-butylphenyl, 2, 4-di-t-pentylphenyl, 2, 4-dicumylphenyl, and 2, 4-di-t-butyl-5-methylphenyl are preferable, 2, 4-di-t-butylphenyl and 2, 4-di-t-pentylphenyl are more preferable, and 2, 4-di-t-butylphenyl is particularly preferable.

R in the above general formula (B)⁷The alkyl group may be an arylalkyl group having 7 to 30 carbon atoms, specifically, an arylalkyl group such as a phenylmethyl group.

Examples of the benzoate compound represented by the general formula (B) include the following compounds Nos. 7 to 15. These may be used alone or in combination of two or more.

However, the compound is not limited to the following compounds.

[ chemical formula 10]

The benzoate compound represented by the general formula (B) may include at least one of the compound B1 and the compound B2 described below. These may be used alone or in combination of two or more.

[ chemical formula 11]

[ chemical formula 12]

The weatherable layer of the agricultural film comprises a thermoplastic resin.

Examples of the thermoplastic resin include: polyolefins such as alpha-olefin polymers including polypropylene, high density polyethylene, low density polyethylene, linear low density polyethylene, polybutene-1, poly-4-methylpentene and the like, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, ethylene-acrylic acid ester copolymers, ethylene-propylene copolymers and the like, and copolymers thereof; halogen-containing resins such as polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, chlorinated polypropylene, polyvinylidene fluoride, chlorinated rubber, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-acrylic ester copolymer, vinyl chloride-maleic ester copolymer, and vinyl chloride-cyclohexylmaleimide copolymer; petroleum resins, coumarone resins, polystyrene, polyvinyl acetate, acrylic resins, copolymers of styrene and/or α -methylstyrene with other monomers (e.g., maleic anhydride, phenyl maleimide, methyl methacrylate, butadiene, acrylonitrile, etc.) (e.g., AS resins, ABS resins, MBS resins, heat-resistant ABS resins, etc.); linear polyesters such as polymethyl methacrylate, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyethylene terephthalate and polybutylene terephthalate, polyamides such as polyphenylene ether, polycaprolactam and polyhexamethylene adipamide, thermoplastic resins such as polycarbonate, branched polycarbonate, polyacetal, polyphenylene sulfide, polyurethane and cellulose resins, and mixtures thereof; or phenolic resins, urea resins, melamine resins, epoxy resins, unsaturated polyester resins, and the like. These compounds may be used alone, or 2 or more kinds may be used in combination. Among them, polyolefin resins such as polyethylene, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, and ethylene-acrylic ester copolymers can also be used.

As the thermoplastic resin, a mixture or copolymer of an α -olefin polymer, polyethylene and another α -olefin polymer, a mixture or copolymer of an α -olefin polymer such as polyethylene and a polyolefin such as an ethylene-vinyl acetate copolymer or an ethylene-propylene copolymer can be used.

The thermoplastic resin may include at least one of linear low-density polyethylene and low-density polyethylene.

The lower limit of the content of the hindered amine light stabilizer and the benzoate compound in the weather-resistant layer is, for example, 0.01 parts by mass or more, preferably 0.2 parts by mass or more, and more preferably 0.8 parts by mass or more, per 100 parts by mass of the thermoplastic resin. On the other hand, the upper limit is, for example, 10 parts by mass or less, preferably 3 parts by mass or less, and more preferably 1 part by mass or less. By setting the content within such a range, the weather resistance can be improved.

The content of the hindered amine light stabilizer in 100 parts by mass of the weather-resistant layer is represented by X (parts by mass), and the content of the benzoate compound is represented by Y (parts by mass).

In this case, the upper limit of X/Y in the weather-resistant layer is 9.5/0.5 or less, preferably 7.5/2.5 or less, more preferably 7.3/2.7 or less, and still more preferably 7.0/3.0 or less. This can improve long-term weather resistance when used for sulfur fumigation or sulfur application. The detailed mechanism is not clear, but it is considered that the long-term weather resistance is obtained by improving the sulfur absorption suppressing ability.

On the other hand, the lower limit of X/Y in the weather-resistant layer is 1.5/8.5 or more, preferably 2.0/8.0 or more, more preferably 2.5/7.5 or more, and still more preferably 3.0/7.0 or more. This improves transparency and long-term weather resistance.

The agricultural film comprises an ultraviolet absorber.

Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and triazine-based ultraviolet absorbers.

Examples of the other ultraviolet absorbers include benzoate-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers other than those of chemical formulae B1 and B2.

These may be used alone or in combination of two or more.

As the benzophenone-based ultraviolet absorber, known ones can be used, and examples thereof include 2, 4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-benzoyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfooxybenzophenone (2- ヒドロキシ -4- メトキシ -5- スルホキシベンゾフェノン), 2-hydroxy-4-methoxy-5-sulfooxytrichloride benzophenone (2- ヒドロキシ -4- メトキシ -5- スルホキシトリハイドライドレイトベンゾフェノン), 2' -dihydroxy-4-methoxybenzophenone, and the like, 2,2',4,4' -tetrahydroxybenzophenone, 2 '-dihydroxy-4, 4' -dimethoxybenzophenone, sodium 2,2 '-dihydroxy-4, 4' -dimethoxybenzophenone-5-sulfonate (2, 2'- ジ ヒドロキシ -4,4' - ジ メトキシ -5- ソ ジ ウ ム スルホキシベンゾフェノン), bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-tert-butyl-4 '- (2-methacryloyloxyethoxyethoxy) benzophenone, 5' -methylenebis (2-hydroxy-4-methoxybenzophenone), And 2-hydroxy-4-methoxy-2' -carboxybenzophenone.

As the benzotriazole-based ultraviolet absorber, known ones can be used, and examples thereof include 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, 2- (2-hydroxy-3, 5-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-dodecyl-5-methylphenyl) benzotriazole, 2- (2-hydroxy-3-tert-butyl-5-alkoxycarbonylethylphenyl) triazole, 2- (2-hydroxy-3, 5-dicumylphenyl) benzotriazole, 2' -methylenebis (4-tert-octyl-6-benzotriazolylphenol), polyethylene glycol ester of 2- (2-hydroxy-3-tert-butyl-5-carboxyphenyl) benzotriazole, 2- (2H-benzotriazol-2-yl) -4, 6-bis (1-methyl-1-phenylethyl) phenol, and 2- (2H-benzotriazol-2-yl) -6- (dodecyl) -4-methylphenol, and the like.

As the triazine-based ultraviolet absorber, known substances can be used, and examples thereof include 2, 4-bis (2, 4-dimethylphenyl) -6- (2-hydroxy-4-octyloxyphenyl) -s-triazine, 2,4, 6-tris (2-hydroxy-4-octyloxyphenyl) -1,3, 5-triazine, 2- (2-hydroxy-4-octyloxyphenyl) -4, 6-bis (2, 4-dimethylphenyl) -1,3, 5-triazine, 2- [4, 6-bis (2, 4-dimethylphenyl) -1,3, 5-triazin-2-yl ] -5- (octyloxy) phenol, 2- (4, 6-Diphenyl-1, 3, 5-triazin-2-yl) -5- (hexyloxy) phenol, and the like.

As the benzoate-based ultraviolet absorber, known ones other than those of chemical formulae B1 and B2 are used, and examples thereof include: resorcinol monobenzoate, 2, 4-di-t-amylphenyl-3 ',5' -di-t-butyl-4 ' -hydroxybenzoate, and the like.

As the salicylate-based ultraviolet absorber, known ones are used, and examples thereof include ethylene glycol salicylate, phenyl salicylate, octyl salicylate, benzyl salicylate, p-tert-butyl salicylate, and homosalate.

As the cyanoacrylate-based ultraviolet absorber, known ones can be used, and examples thereof include ethyl-a-cyano-B, B-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (P-methoxyphenyl) acrylate, and the like.

The lower limit of the content of the ultraviolet absorber in the agricultural film is, for example, 0.01 part by mass or more, preferably 0.05 part by mass or more, and more preferably 0.07 part by mass or more, per 100 parts by mass of the thermoplastic resin. On the other hand, the upper limit of the ultraviolet absorber is, for example, 1 part by mass or less, preferably 0.5 part by mass or less, and more preferably 0.2 part by mass or less. By setting the content within such a range, the weather resistance can be improved.

The thickness of the agricultural film 100 is not particularly limited, but is, for example, 10 to 1mm, preferably 30 to 500 μm, and more preferably 50 to 300 μm.

Fig. 1 is a sectional view showing an example of the structure of the agricultural film according to the embodiment.

The agricultural film 100 shown in fig. 1(a) includes at least one layer (weather-resistant layer 10) containing the hindered amine light stabilizer and the benzoate compound. The agricultural film 100 may have a single-layer or multi-layer weather-resistant layer 10 on the inside in the thickness direction.

Further, as shown in fig. 1(b), the agricultural film 100 may be constituted by a multilayer film having a multilayer structure having one or two or more other layers (base layers 20) in addition to the weather-resistant layer 10. The multilayer film may be formed of two or more layers, and may be formed of three, four, five or more layers, or seven or more layers, for example. The upper limit of the number of layers of the multilayer film is not particularly limited, and may be, for example, ten layers or less.

In the multilayer film, the ultraviolet absorber may be contained in any layer, may be contained in one layer or two or more layers, or may be contained in the outermost layer.

The base layer 20 may be provided on one surface of the weather-resistant layer 10, or the base layer 20 and the surface layer may be provided as other layers on one surface and the other surface of the weather-resistant layer 10. The other layer may contain only one of the hindered amine light stabilizer and the benzoate compound, or may not contain both of them, as long as it has a structure not containing both of them, unlike the weather-resistant layer 10.

The other layer may be composed of the above thermoplastic resin, and may contain other additives described below as necessary. As the thermoplastic resin of the other layer, for example, linear low-density polyethylene, or the like can be used.

The agricultural film 100 of the present embodiment has a characteristic of sulfur absorption suppressing ability.

The sulfur absorption-inhibiting ability can be evaluated by using, as an index, the degree of difficulty of absorption of sulfur (i.e., the amount of sulfur uptake) in the agricultural film 100.

The index of the amount of sulfur uptake can be calculated from (Δ W × (H2/H1))/H2, i.e., Δ W/H1, when the amount of sulfur uptake measured in step a described below is denoted by Δ W, the thickness of the agricultural film 100 is denoted by H1, and the thickness of the weather-resistant layer 10 is denoted by H2. A smaller value of Δ W/H1 is one of the indexes of higher sulfur absorption suppressing ability.

Hereinafter, step a for calculating Δ W (sulfur uptake) of the agricultural film 100 will be described.

< step a >

Step a 1: the content (ppm) of sulfur element in the agricultural film 100 before the sulfur fumigation treatment was measured using the agricultural film 100 in the following order of (1), (2), (4), and (5), and the measured value was denoted as S₀。

Step a 2: the content (ppm) of sulfur element in the agricultural film 100 after the sulfur fumigation treatment was measured using the agricultural film 100 as the measurement object in step a1 in the order of (1), (2), (3), (4), and (5) below, and the measurement value was denoted as S₁. Wherein S is₁The average of four measurements was used.

Step a 3: s obtained in the above step a1 was used₀And S obtained in step a2₁The sulfur uptake (ppm) of the agricultural film 100 was calculated based on the following formula (I).

|S₁-S₀I.A. formula (I)

(1): preparation of test piece

The agricultural film 100 was cut to prepare a test piece a of a strip film having a length of 13cm and a width of 2.5 cm.

(2): cleaning treatment

The agricultural film 100A is immersed in distilled water at a liquid temperature of 25 ℃, taken out of the distilled water, and dried.

(3): sulphur fumigation treatment

A vinyl house having a closed space of a substantially rectangular parallelepiped shape having a length of 50cm, a width of 56cm and a height of 60cm was prepared. Next, a stirrer was installed on the top surface inside the vinyl house, a heating device was installed on the bottom surface inside the vinyl house, and a tray made of aluminum foil was installed on the heating device. Four test pieces a were set in a state of being suspended in the inside of the vinyl house.

Then, the following sulfur fumigation operation was repeated four times.

(Sulfur Fumigation operation)

120mg of powdered sulphur was loaded into the trays. Next, the tray was heated at 190 ℃ for 4 hours with the rotation speed of the stirrer set at 180 rpm.

(4): surface treatment

The test piece a was irradiated with light for 102 minutes under the following conditions, and then sprayed with water for 18 minutes while being irradiated with light under the following conditions. The total of 120 minutes of the operation was set as 1 cycle, and 60 cycles were performed in total, and the test piece a was subjected to surface treatment for 120 hours in total.

(conditions for light irradiation)

Irradiating the test piece a with an irradiation intensity of 60W/m at a temperature of 65 ℃ and a relative humidity of 50%²The xenon lamp of (1).

According to the findings of the present inventors, it has been found that measurement variation in the content of elemental sulfur contained in a film can be reduced by performing appropriate surface treatment after sulfur fumigation. The detailed mechanism is not clear, and it is considered that sulfur adhering to the film surface can be appropriately taken out by surface treatment. It is also known that the surface treatment is important for not only light irradiation but also water dispersion.

(5): determination of the elemental Sulfur content

A200 mg sample obtained by cutting the test piece a in the plate thickness direction was added to 5g of 70% nitric acid to obtain a nitric acid solution. The nitric acid solution was subjected to pretreatment for liquefying the sample by a microwave wet digestion method, thereby obtaining a measurement solution. The content of elemental sulfur in the obtained measurement solution was measured using an ICP emission spectrometry apparatus. The content of the sulfur element in the measurement solution was defined as the content (ppm) of the sulfur element in the agricultural film 100.

According to the findings of the present inventors, it has been found that, in a vinyl house used for sulfur fumigation many times, by using a new vinyl house at an appropriate timing, variation in the measurement of the sulfur element content can be reduced.

The sulfur uptake measured in the above step a was represented by Δ W, the thickness of the agricultural film 100 was represented by H1, and the thickness of the layer containing the hindered amine light stabilizer and the benzoate compound (weather-resistant layer 10) was represented by H2.

In this case, the agricultural film 100 is configured to satisfy (Δ Wx (H2/H1))/H2, that is, the upper limit of Δ W/H1 is, for example, 4.70ppm/μm or less, preferably 4.60ppm/μm or less, and more preferably 4.50ppm/μm or less. The lower limit of Δ W/H1 can be set to, for example, 2.80 ppm/. mu.m or more.

Here, the film thickness ratio in the weather-resistant layer 10 contained in the entire agricultural film 100 was calculated from H2/H1. The sulfur uptake per unit thickness in the weatherable layer 10 was calculated by 1/H2.

The upper limit of the haze value of the agricultural film 100 measured according to JIS K7136 may be, for example, 50% or less, preferably 40% or less, and more preferably 30% or less. The lower limit of the haze value is not particularly limited, and may be 0% or more, or may be 1% or more.

The agricultural film 100 can be used for various purposes, for example, a material for forming various agricultural and horticultural equipment such as a greenhouse, a material for protecting soil, a material for storing soil and the like, and the like. Among them, it is preferably used for forming a greenhouse.

Next, a description will be given of an agricultural film-forming resin composition of the present embodiment for forming the agricultural film 100 described above.

The resin composition for forming an agricultural film (hereinafter, simply referred to as "resin composition") contains one or more hindered amine light stabilizers selected from the compounds represented by the general formula (a1) and the compounds represented by the general formula (a2), one or more benzoate compounds selected from the compounds represented by the general formula (B), one or more ultraviolet absorbers selected from the benzophenone ultraviolet absorbers, the benzotriazole ultraviolet absorbers, and the triazine ultraviolet absorbers, and the thermoplastic resin.

The resin composition is configured such that X, Y satisfies the above-mentioned range when the content of the hindered amine light stabilizer in terms of mass is represented by X and the content of the benzoate compound in terms of mass is represented by Y.

The resin composition can be used for forming an agricultural film, and more specifically, can be used for forming a weather-resistant layer of an agricultural film.

The compounding ratio of the above-mentioned components in the resin composition can be, for example, the compounding ratio in the weather-resistant layer described in the agricultural film.

The resin composition may contain other additives commonly used for agricultural films in addition to the above-mentioned ingredients within a range not impairing the effects of the present invention.

Examples of the other additives include a phenol-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, another hindered amine compound, a nucleating agent, a processability improver, a filler, a plasticizer, a metal soap, an infrared absorber, an antistatic agent, a dew-proofing agent ( agent), an antifogging agent, and an antimildew agent. These may be used alone, or 2 or more of them may be used in combination.

Examples of the above-mentioned phenolic antioxidant include 2, 6-di-t-butyl-p-cresol, 2, 6-diphenyl-4-octadecyloxyphenol, stearyl (3, 5-di-t-butyl-4-hydroxyphenyl) propionate, distearyl (3, 5-di-t-butyl-4-hydroxybenzyl) phosphonate, tridecyl 3, 5-di-t-butyl-4-hydroxybenzylthioacetate, thiodiethylene bis [ (3, 5-di-t-butyl-4-hydroxyphenyl) propionate ], 4' -thiobis (6-t-butyl-m-cresol), 2-octylthio-4, 6-bis (3, 5-di-t-butyl-4-hydroxyphenoxy) -s-triazine, and the like, 2,2' -methylenebis (4-methyl-6-tert-butylphenol), ethylene glycol bis [3, 3-bis (4-hydroxy-3-tert-butylphenyl) butyrate ], 4' -butylidenebis (2, 6-di-tert-butylphenol), 4' -butylidenebis (6-tert-butyl-3-methylphenol), 2' -ethylenebis (4, 6-di-tert-butylphenol), 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, bis [ 2-tert-butyl-4-methyl-6- (2-hydroxy-3-tert-butyl-5-methylbenzyl) phenyl ] terephthalate, ethylene glycol bis [3, 3-bis (4-hydroxy-3-tert-butylphenyl) butyrate ], bis [2,2' -ethylidenebis (4, 6-di-tert, 1,3, 5-tris (2, 6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3, 5-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) -2,4, 6-trimethylbenzene, 1,3, 5-tris [ (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl ] isocyanurate, tetrakis [ methylene-3- (3',5' -di-tert-butyl-4 ' -hydroxyphenyl) propionate ] methane, 2-tert-butyl-4-methyl-6- (2-acryloyloxy-3-tert-butyl-5-methylbenzyl) phenol, 3, 9-bis [2- (3-tert-butyl-4-hydroxy-5-methylhydrocinnamoyloxy) -1, 1-dimethylethyl ] -2,4,8, 10-tetraoxaspiro [5.5] undecane, triethylene glycol bis [ beta- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate ], tocopherol, and the like.

Examples of the phosphorus-based antioxidant include triphenyl phosphite, tris (2, 4-di-t-butylphenyl) phosphite, tris (2, 5-di-t-butylphenyl) phosphite, tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (mixed mono-and dinonylphenyl) phosphite, diphenyl phosphite, 2' -methylenebis (4, 6-di-t-butylphenyl) octyl phosphite, diphenyldecyl phosphite, diphenyloctyl phosphite, bis (nonylphenyl) pentaerythritol diphosphite, phenyldiisodecyl phosphite, tributyl phosphite, tris (2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite, dibutyl phosphite, dilauryl phosphite, trilauryl trithiophosphite, phosphorous acid, Bis (neopentyl glycol). 1, 4-cyclohexanedimethyldiphosphite, bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2, 5-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2, 6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2, 4-diisopropylphenylphenyl) pentaerythritol diphosphite, distearylpentaerythritol diphosphite, tetrakis (C12-15 mixed alkyl) -4,4 '-isopropylidenediphenyl phosphite, bis [2,2' -methylenebis (4, 6-dipentylphenyl)]Isopropylidene diphenyl phosphite, tetra (tridecyl)) 4,4' -Butylenebis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1, 3-tris (2-methyl-5-tert-butyl-4-hydroxyphenyl) butanetriphosphite, tetrakis (2, 4-di-tert-butylphenyl) biphenylene diphosphonite, tris (2- [ (2,4,7, 9-tetra-tert-butylbenzo [ d, f ] dibenzo [ d, f ] s][1,3,2]Dioxaphosphanes-6-yl) oxy]Ethyl) amine, 2- (1, 1-dimethylethyl) -6-methyl-4- [3- [ [2,4,8, 10-tetrakis (1, 1-dimethylethyl) dibenzo [ d, f ]][1,3,2]Dioxaphosphanes-6-yl]Oxy radical]Propyl radical]Phenol, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-butyl-2-ethylpropanediol 2,4, 6-tri-tert-butylphenol monophosphite, and the like.

Examples of the sulfur-based antioxidant include dialkyl thiodipropionate esters such as dilauryl ester, dimyristyl ester, myristyl stearyl ester, and distearyl ester of thiodipropionic acid, and β -alkylmercaptopropionic acid esters of polyhydric alcohols such as pentaerythritol tetrakis (. beta. -dodecylmercaptopropionate).

Examples of the other hindered amine compound include 2,2,6, 6-tetramethyl-4-piperidyl stearate, 1,2,2,6, 6-pentamethyl-4-piperidyl stearate, 2,2,6, 6-tetramethyl-4-piperidyl benzoate, bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl) sebacate, tetrakis (2,2,6, 6-tetramethyl-4-piperidyl butane tetracarboxylate, tetrakis (1,2,2,6, 6-pentamethyl-4-piperidyl butane tetracarboxylate, bis (2,2,6, 6-tetramethyl-4-piperidyl) ditridecyl) -1,2,3, 4-butanetetracarboxylate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl) ditridecyl-1, 2,3, 4-butanetetracarboxylate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl) -2-butyl-2- (3, 5-di-tert-butyl-4-hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2,2,6, 6-tetramethyl-4-piperidinol/diethyl succinate polycondensate, 1, 6-bis (2,2,6, 6-tetramethyl-4-piperidylamino) hexane/dibromoethane polycondensate, 1, 6-bis (2,2,6, 6-tetramethyl-4-piperidylamino) hexane/2, 4-dichloro-6-morpholino-s-triazine polycondensate, 1, 6-bis (2,2,6, 6-tetramethyl-4-piperidylamino) hexane/2, 4-dichloro-6-tert-octylamino-s-triazine polycondensate, 1,5,8, 12-tetrakis [2, 4-bis (N-butyl-N- (2,2,6, 6-tetramethyl-4-piperidyl) amino) -s-triazin-6-yl ] -1,5,8, 12-tetraazadodecane, 1,5,8, 12-tetrakis [2, 4-bis (N-butyl-N- (1, hindered amine compounds such as 2,2,6, 6-pentamethyl-4-piperidyl) amino) -s-triazin-6-yl ] -1,5,8, 12-tetraazadodecane, 1,6, 11-tris [2, 4-bis (N-butyl-N- (2,2,6, 6-tetramethyl-4-piperidyl) amino) -s-triazin-6-ylaminoaundecane, and 1,6(1,2,2,6, 6-pentamethyl-4-piperidyl) amino) -s-triazin-6-ylaminoaundecane.

Examples of the nucleating agent include metal salts of aromatic carboxylic acids such as aluminum p-tert-butylbenzoate and sodium benzoate; acidic phosphate ester metal salts such as sodium bis (2, 4-di-t-butylphenyl) phosphate, lithium bis (2, 4-di-t-butylphenyl) phosphate, and sodium-2, 2' -methylenebis (4, 6-di-t-butylphenyl) phosphate; and polyol derivatives such as dibenzylidene sorbitol and bis (methylbenzylidene) sorbitol.

The processability improver can be appropriately selected from known processability improvers, and for example, ethylene bisstearamide, erucamide and the like can be used.

Examples of the filler include calcium carbonate, calcium oxide, calcium Hydroxide, zinc carbonate, zinc sulfide, Magnesium oxide, Magnesium Hydroxide, Magnesium carbonate, aluminum oxide, aluminum Hydroxide, sodium aluminum silicate, hydrocalumite, aluminum silicate, Magnesium silicate, calcium silicate, metal silicates such as zeolite, activated clay, talc, clay, red iron oxide, asbestos, antimony trioxide, silica, glass beads, mica, sericite, glass flakes, asbestos, wollastonite, potassium titanate, PMF (mineral fiber), gypsum fiber, diatomaceous earth, MOS (Magnesium Hydroxide Sulfate Hydrate), fibrous Magnesium compounds, phosphate fiber, glass fiber, carbon fiber, aramid fiber, cellulose nanofiber, and the like. Among them, inorganic fillers may be used. The filler is preferably surface-treated with a surface treatment agent such as a titanium-based or silane-based agent in order to improve affinity with the resin.

Examples of the plasticizer include phthalic acid esters, dibasic acid esters, chlorinated paraffins, polyesters, epoxidized esters, phosphoric acid esters, trimellitic acid esters, and the like.

Examples of the metal soap include salts of metals such as magnesium, calcium, aluminum, and zinc, and saturated or unsaturated fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, and oleic acid. The water content, melting point, particle size, fatty acid composition, and production method do not depend on a double decomposition method in which a fatty acid salt of an alkali metal and a metal (hydrogen) oxide are reacted, or a direct method in which a neutralization reaction is carried out in the presence or absence of a solvent for a fatty acid and a metal (hydrogen) oxide, and any one of the fatty acid and the metal may be used in an excess amount.

Examples of the infrared absorber include hydrotalcite compounds and lithium aluminum composite hydroxides. These may be used alone or in combination of two or more.

The hydrotalcite compound may be a natural product, a synthetic product, or a compound modified with an alkali metal such as lithium. Preferred are of the general formula: ZnxMgyAl₂(OH)₂(x+y+2)CO₃·nH₂A compound having a composition represented by O (wherein x represents 0 to 3, y represents 1 to 6, and x + y represents 4 to 6. n represents 0 to 10) can be used independently of the presence or absence of crystal water or the presence or absence of surface treatment.

The hydrotalcite-based compound may be a compound obtained by dehydrating crystal water, or a compound coated with a higher fatty acid such as stearic acid, a higher fatty acid metal salt such as an alkali metal oleate, an organic sulfonic acid metal salt such as an alkali metal dodecylbenzenesulfonate, a higher fatty acid amide, a higher fatty acid ester, a wax, or the like.

Examples of the hydrotalcite compound include: natural hydrotalcite and trade name: DHT-4A (made by Kyowa chemical industries Co., Ltd.), MAGCLEAR (made by Katywa chemical industries Co., Ltd.), MAGCELLER (made by Kyowa chemical industries Co., Ltd.), STABIACE HT-P (made by Sakai chemical industries Co., Ltd.), and the like.

Examples of the lithium aluminum composite hydroxide include OPTIMA-SS (manufactured by koyota industries), and Mizukalac (manufactured by zernike chemical industries).

Examples of the antistatic agent include cationic antistatic agents such as fatty acid quaternary ammonium salt and polyamine quaternary ammonium salt; anionic antistatic agents such as higher alcohol phosphate ester salts, higher alcohol EO adducts, polyethylene glycol fatty acid esters, anionic alkyl sulfonates, higher alcohol sulfate ester salts, higher alcohol ethylene oxide adduct sulfate ester salts, and higher alcohol ethylene oxide adduct phosphate ester salts; nonionic antistatic agents such as polyol fatty acid esters, polyethylene glycol phosphate esters and polyoxyethylene alkyl allyl ethers; amphoteric alkyl betaines such as alkyldimethylaminoacetic acid betaine, and amphoteric antistatic agents such as imidazoline-type amphoteric active agents.

Examples of the anti-kogation agents include sorbitan-based surfactants such as sorbitan fatty acid esters and alkylene oxide adducts thereof, e.g., sorbitan monopalmitate, sorbitan monostearate, sorbitan monopalmitate, sorbitan monooleate, sorbitan dioleate, etc., glycerol monopalmitate, glycerol monostearate, diglycerol distearate, triglycerol monostearate, tetraglycerol ditrimentanate, glycerol monooleate, diglycerol sesquioleate, tetraglycerol monooleate, hexaglycerol trioleate, tetraglycerol monolaurate, hexaglycerol monolaurate, etc., glycerol-based surfactants such as glycerol fatty acid esters and alkylene oxide adducts thereof, e.g., polyethylene glycol monopalmitate, Polyethylene glycol surfactants such as polyethylene glycol monostearate, alkylene oxide adducts of alkylphenols, esters of sorbitan/glycerin condensates with organic acids, polyoxyethylene (2 mol) stearylamine, polyoxyethylene (4 mol) stearylamine, polyoxyethylene (2 mol) stearylamine monostearate, polyoxyethylene alkylamines such as polyoxyethylene (4 mol) laurylamine monostearate, and fatty acid esters thereof.

Examples of the antifogging agent include fluorine compounds having a perfluoroalkyl group, an ω -hydrofluoroalkyl group, and the like (particularly, fluorine-based surfactants), silicone compounds having an alkylsiloxane group (particularly, silicone-based surfactants), and the like.

Examples of the above-mentioned mildewcide include: organic fungicides such as nitrogen-and sulfur-containing, organic bromides, nitrogen-and arsenic-containing, and inorganic fungicides such as silver compounds.

The method for producing an agricultural film according to the present embodiment includes a molding step of molding the resin composition into a film shape.

The molding step may be performed by a known method, and may be performed by a melt extrusion molding method such as a blow molding method and a die method, a solution casting method, a calendering method, a co-extrusion method by a blow molding method and a die method, a multilayer processing method, a lamination method, an internal/external heating method, or the like. Thus, a single-layer or multi-layer agricultural film can be obtained.

The method for producing an agricultural film may further include a mixing step of mixing the above components to obtain a resin composition.

The mixing step may be a method of mixing the raw materials in advance using various mixers such as a tumbler and a henschel mixer, and then melt-kneading the mixture using a banbury mixer, a roll, a brabender mixer, a uniaxial kneading extruder, a biaxial kneading extruder, a kneader, or the like.

Further, the resin composition may be produced by supplying the components to an extruder using a feeder without mixing the components in advance, or by mixing only a part of the components in advance, and melt-kneading the components. Further, a resin composition may be produced by mixing a part of the components in advance, supplying the mixture to an extruder, and melt-kneading the mixture to obtain a resin composition as a master batch, and further mixing the master batch with the other components and melt-kneading the mixture.

The synthetic resin used in the mixing and kneading step may have a predetermined shape such as powder or pellet, or a fibrous shape.

According to the present embodiment, a method for improving the sulfur absorption inhibiting ability of an agricultural film can be provided. In a method for improving the sulfur absorption inhibiting ability of the agricultural film, the sulfur absorption inhibiting ability of the agricultural film 100 can be improved by adding a benzoate compound as a synergist thereof to a hindered amine light stabilizer.

These given hindered amine-based light stabilizers, and given benzoate compounds, use the compounds described in the agricultural films.

According to the present embodiment, a method for growing a plant using the agricultural film 100 can be provided. The method for cultivating a plant may comprise the steps of: disposing the agricultural film 100 on agricultural and horticultural equipment; arranging plants in the agricultural or horticultural equipment; and carrying out sulfur fumigation in equipment for agricultural and horticultural use. This enables to realize an agricultural or horticultural facility excellent in long-term weather resistance. As the equipment for agricultural and horticultural use, for example, a greenhouse is used.

While the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than the above-described configurations may be adopted. The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within a range in which the object of the present invention can be achieved are also included in the present invention.

In the following, reference is made to examples of the reference schemes.

1. An agricultural film for use in sulfur fumigation or sulfur application having a weatherable layer comprising:

a hindered amine-based light stabilizer which is one or more compounds selected from the group consisting of compounds represented by the following chemical formulae A1 to A3;

a benzoate compound which is at least one of a compound represented by the following chemical formula B1 and a compound represented by the following chemical formula B2;

an ultraviolet absorber containing one or more members selected from the group consisting of benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and triazine-based ultraviolet absorbers; and

a thermoplastic resin,

when the content of the hindered amine light stabilizer is X and the content of the benzoate compound is Y, X, Y satisfies 1.5/8.5X/Y7.5/2.5.

[ chemical formula 13]

[ chemical formula 14]

[ chemical formula 15]

[ chemical formula 16]

[ chemical formula 17]

2. The agricultural film according to claim 1, wherein,

the content of the ultraviolet absorber is 0.01 mass% or more and 1 mass% or less with respect to 100 mass% of the thermoplastic resin.

3. The agricultural film according to 1. or 2, wherein,

the total content of the hindered amine light stabilizer and the benzoate compound is 0.01 mass% or more and 10 mass% or less with respect to 100 mass% of the thermoplastic resin.

4. The agricultural film according to any one of claims 1 to 3, wherein,

the agricultural film has a multilayer structure including the weather-resistant layer and other layers containing a thermoplastic resin.

5. The agricultural film according to any one of claims 1 to 4, wherein,

the thermoplastic resin includes linear low-density polyethylene or low-density polyethylene.

6. The agricultural film according to any one of claims 1 to 5, wherein,

the agricultural film is used to form a greenhouse.

7. An agricultural film-forming resin composition for forming an agricultural film according to any one of claims 1 to 6.

8. A method for cultivating a plant, comprising the steps of:

a step of disposing the agricultural film described in any one of 1 to 6 in a greenhouse;

disposing plants in the greenhouse;

and (3) carrying out sulfur fumigation in the greenhouse.

Examples

The present invention will be described in detail below with reference to examples, but the present invention is not limited to the description of these examples.

< preparation of resin composition >

(example 1)

100 parts by mass of a thermoplastic resin (linear low-density polyethylene), 0.3 part by mass of a hindered amine light stabilizer of the following compound A1, 0.7 part by mass of a benzoate compound of the following compound B1, an ultraviolet absorber (a benzophenone-based UV absorber, manufactured by ADEKA Co., Ltd., product name: ADECASTAB 1413)0.1 part by mass, a phenol-based antioxidant (stearyl (3, 5-di-t-butyl-4-hydroxyphenyl) propionate) 0.05 part by mass, a phosphorus-based antioxidant (tris (2, 4-di-t-butylphenyl) phosphite) 0.05 part by mass, and a metal soap (calcium stearate) 0.05 part by mass were mixed for 30 minutes by using a tumble mixer (manufactured by Ikon Co., Ltd.), using a twin-screw extruder (TEX-28V, manufactured by Nissan TPK Co., Ltd.), pellets were obtained at an extrusion temperature of 190 ℃ and a screw rotation speed of 150 rpm. The granulated pellets were dried at 60 ℃ for 8 hours using a hot air dryer (WINDY OVEN WFO-1001SD, manufactured by EYELA). Thus, a resin composition in the form of pellets was obtained.

(examples 2 to 14, comparative examples 1 to 3)

A pellet-shaped resin composition was obtained by mixing and extrusion processing in the same manner as in example 1, except that the thermoplastic resin, the hindered amine light stabilizer, the benzoate compound, and the ultraviolet absorber were used in the compounding ratios shown in table 1.

Compound a1 used was pulverized with a mortar and placed in a desiccator overnight (overnight). Compound a2 was added using a liquid addition device.

In table 1, when the content of the hindered amine light stabilizer is X (parts by mass) and the content of the benzoate compound is Y (parts by mass) in 100 parts by mass of the above resin composition for forming the weather-resistant layer, X/Y represents the content ratio thereof.

The raw material information in table 1 is shown below.

(thermoplastic resin)

Linear low-density polyethylene: NF464N manufactured by japan polyethylene corporation, density: 0.918kg/m³

Low density polyethylene: NUC-8230 manufactured by NUC corporation, Inc., density: 0.928kg/m³

Ethylene-vinyl acetate copolymer resin: ultrathene 630 manufactured by Tosoh corporation, Density: 0.936kg/m³

(hindered amine light stabilizer)

[ chemical formula 18]

[ chemical formula 19]

[ chemical formula 20]

(benzoic acid ester Compound)

[ chemical formula 21]

[ chemical formula 22]

(ultraviolet absorber)

Ultraviolet absorber C1: benzophenone-based UV absorber (ADECASTAB 1413 manufactured by ADEKA K.K.)

Ultraviolet absorber C2: benzotriazole-based UV absorber (ADECASTAB LA-36 manufactured by ADEKA K.K.)

Ultraviolet absorber C3: triazine series UV absorber (Cyasorb UV-1164 manufactured by Cytec Co., Ltd.)

[ Table 1]

< preparation of agricultural film >

Using the pelletized resin compositions obtained in the respective examples and comparative examples, the molding machine was operated at a resin temperature of: 190 ℃ and torque: 50-70N · m, extrusion yield: extruded under the condition of 1.5kg/h to prepare a single layer agricultural film having a thickness of 50 μm. In this case, the thickness H1 of the agricultural film was 50 μm, and the thickness H2 of the weather-resistant layer containing the hindered amine light stabilizer and the benzoate compound (synergist) was 50 μm. The thickness was measured using a digital microscope for a cut surface obtained by cutting an agricultural film in the thickness direction.

The detailed conditions for producing the agricultural film are as follows.

The obtained pellets were subjected to film formation by blow molding using a circular die having a diameter of 25mm and a slit width of 0.8mm in a LABO PLASTOMILL 4C150-01 manufactured by toyoyo seiki having an extrusion part of 20mm in diameter and an L/D of 25 (full-flight screw CR of 2.0), and the obtained film was taken up by a film take-up device manufactured by sumtik corporation. The conditions of the extrusion section were set to 190 ℃ processing temperature, 60rpm screw speed, and the take-up speed was adjusted so that the film thickness became 50 μm for agricultural films.

The obtained agricultural film was measured for sulfur uptake and haze value, and evaluated for long-term weather resistance and transparency.

< measurement of Sulfur uptake >

(step a1)

The obtained agricultural film was used to measure the sulfur content (ppm) of the agricultural film before sulfur fumigation treatment in the following order (1), (2), (4), and (5). The measured value is regarded as S₀。

(step a2)

The content (ppm) of the sulfur element in the agricultural film after the sulfur fumigation treatment was measured using the agricultural film as a measurement target of the content of the sulfur element before the sulfur fumigation treatment in step a1 in the following order of (1), (2), (3), (4), and (5). The measured value is regarded as S₁. Wherein S is₁The average of the four measurements was taken.

(step a3)

Then, S obtained in the above step a1 is used₀And S obtained in step a2₁The sulfur uptake amount Δ W (ppm) of the agricultural film was calculated based on the following formula (I).

ΔW(ppm)＝|S₁-S₀I.A. formula (I)

(1): preparation of test piece

The agricultural film was cut to prepare a test piece a of a strip film having a length of 13cm and a width of 2.5 cm.

(2): cleaning treatment

The test piece a, 3L of distilled water having a liquid temperature of 25 ℃ and a stirrer blade were placed in a beaker having a diameter of 18cm, and stirred for 5 minutes by the stirrer. The test piece a immersed in distilled water was taken out, and the surface thereof was wiped off with a dust-free wiping paper. Then, the test piece a was kept in a suspended state for 30 minutes to be dried.

(3): sulphur fumigation treatment

An overview of a fumigation apparatus 200 for sulphur fumigation treatment is shown in figure 2.

First, a vinyl house 210 (Portable fune home eco onod manufactured by AS ONE) having a substantially rectangular closed space of 50cm long by 56cm wide by 60cm high is prepared.

Next, a stirrer 220 (Three one motor BL1200, manufactured by new eastern science) is installed on the top surface 212 of the inside of the vinyl house 210, and a heating device (heating plate 230) is installed on the bottom surface 214 of the inside thereof. An aluminum foil tray 240 (bottom surface area: 16 cm) was placed at the center of the hot plate 230(IKA C-mag hot plate HP4)²Width: 4cm, depth: 4cm, height: 2 cm). On the other hand, 4 test pieces a (test pieces 250) were set in a state suspended inside the vinyl house 210. The 4 test pieces 250 are arranged at an appropriate interval from each other so as to be positioned at approximately half the height of the vinyl house 210.

Then, the following sulfur fumigation operation was repeated four times.

(Sulfur Fumigation operation)

First, 120mg of powdered sulfur 260 was loaded into the tray 250. Subsequently, the stirrer 220 was rotated at 180rpm, and in this state, the tray 240 was heated at 190 ℃ for 4 hours using the hot plate 230. At this point, the heating plate 230 takes about 4 minutes to heat from 20 ℃ to 190 ℃. Then, the heating plate 230 is stopped and the heating is finished, and it takes about 30 minutes to cool naturally to room temperature.

(4): surface treatment

The test piece a was irradiated with light for 102 minutes under the following conditions, and then sprayed with water for 18 minutes while being irradiated with light under the following conditions. The total of 120 minutes of the operation was set as 1 cycle, and 60 cycles were performed in total, and the test piece a was subjected to surface treatment for 120 hours in total.

(conditions for light irradiation)

Using a xenon weather resistance test apparatus, a test piece a was irradiated with UV irradiation intensity of 60W/m at a blackboard temperature of 65 ℃ and a relative humidity of 50% using a borosilicate filter²And a xenon lamp with a wavelength of 300-400 nm for 120 hours.

(5): determination of the elemental Sulfur content

The test piece a was cut in the plate thickness direction, and 200mg of the thus-obtained sample was added to 5g of 70% nitric acid to obtain a nitric acid solution. The nitric acid solution was subjected to pretreatment for liquefying the sample under conditions of 230 ℃ and 40Bar pressure for 1 hour using a microwave wet digestion apparatus (manufactured by Analytik jena, TOPwave), to obtain a measurement solution.

The content of sulfur element in the obtained measurement solution was measured by using an ICP emission spectrometry apparatus (SPS 3500, manufactured by SII Nano Technology).

In table 1, regarding the sulfur uptake amount (Δ W × (H2/H1))/H2), that is, the numerical value of Δ W/H1, the case where the value was less than-5% of the numerical value of comparative example 3 was evaluated as o, and the case where the value was the same as the numerical value of comparative example 3 (within ± 5%) or exceeded + 5% of the numerical value of comparative example 3 was evaluated as x.

< Long-term weather resistance >

The agricultural films of examples and comparative examples were irradiated with UV radiation intensity of 60W/m according to ISO4892-2 at a blackboard temperature of 65 ℃ and a relative humidity of 50% using a borosilicate filter²And a xenon lamp having a wavelength of 300 to 400nm for 120 hours, thereby performing a weather resistance acceleration test. In this case, 120 minutes was set as 1 cycle, and irradiation with light alone was performed for 102 minutes, irradiation with light and spraying with water were performed for 18 minutes in the irradiation time of 1 cycle, and the total of 120 hours was performed by performing 60 cycles.

In this weathering acceleration test, every 120 hours, the weathering acceleration test was performed in the same manner as in (3): the sulfur fumigation treatment was performed 1 time in the same manner (sulfur fumigation operation).

The tensile strength residual ratio (%) of each film was measured at a test speed of 500mm/min at 0h, 840h, 1200h and 2040h of the weather resistance acceleration test, using AG-Xplus manufactured by Shimadzu corporation, according to JIS K7161-1. The tensile strength residual rate (%) is defined as a rate of decrease in tensile strength when the tensile strength of the film before the weather resistance acceleration test is 100%.

As a result, the residual ratios of tensile strengths of comparative examples 2 and 3 were smaller than those of examples 1 to 14 and comparative example 1 at 1200 hours, and the residual ratios of tensile strengths of comparative examples 1 to 3 were smaller than those of examples 1 to 14 at 2040 hours. This shows that the agricultural films of examples 1 to 14 are superior to those of comparative examples 1 to 3 in long-term weather resistance.

In Table 1, the tensile strength remaining percentage at 2040h was evaluated as "O" in the range where it was not practically problematic, and the tensile strength remaining percentage at 2040h was evaluated as "X".

< transparency >

Haze (Haze value:%) was measured according to JIS K7136 for the agricultural films of examples and comparative examples.

In table 1, a case where the haze value is 20% or less is regarded as "very good", a case where the haze value is more than 20% and 30% or less is regarded as "good", a case where the haze value is more than 30% and 50% or less is regarded as "Δ", and a case where the haze value is more than 50% is regarded as "x".

In table 1, the case where the haze value was within the range that had no practical problem was evaluated as o, and the case where the haze value could not be used in practical terms was evaluated as x.

The haze values of the agricultural films of examples 1 to 14 were as low as can be used without practical problems. On the other hand, the haze value of the agricultural film of comparative example 1 was a significantly higher value than that of each example.

Further, the agricultural films of examples 1 to 14 and comparative example 1 were subjected to surface observation. As a result, no surface bloom was observed in examples 1 to 14, whereas surface bloom was observed in comparative example 1.

It is thus presumed that the agricultural film of comparative example 1 has a haze value increased by blooming from the layer containing the hindered amine light stabilizer and the benzoate compound.

It was shown that the agricultural films of examples 1 to 14 were superior in long-term weather resistance to comparative examples 2 and 3, and the agricultural films of examples 1 to 14 were superior in transparency to comparative example 1. Such agricultural films are suitable as components for the cultivation of crops or plants, in particular as materials which can be used in greenhouses.

Further, by appropriately blending a hindered amine light stabilizer and a benzoate compound, the sulfur absorption inhibiting ability of the agricultural film can be improved. Thus, the agricultural film of the embodiment can be suitably used for sulfur fumigation, sulfur application, and the like performed when plants or crops are grown.

This application claims priority based on japanese application No. 2019-147141 filed on 8/9/2019 and the entire disclosure of which is incorporated herein.

Description of the symbols

10 weatherable layer

20 base layer

100 agricultural film

200 fumigation equipment

210 plastic greenhouse

212 top surface of the base plate

214 bottom surface

220 stirring machine

230 heating plate

240 tray

250 test piece

250 tray

260 of sulfur.