JP2575463B2 - Agricultural synthetic resin coating - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an agricultural coating material, and more particularly to an agricultural synthetic resin coating material capable of preventing adhesion of algae and maintaining high transparency for a long period of time.

[Conventional technology]

In recent years, so-called house cultivation and tunnel cultivation in which useful plants are cultivated under agricultural covering materials such as vinyl films for agriculture in order to enhance their marketability and productivity by forcing, semi-forcing or suppressing cultivation of agricultural crops. It is being actively performed.

Synthetic resin coating materials currently used in house cultivation and tunnel cultivation, such as vinyl chloride resin films, are compounded with plasticizers, anti-fogging agents, stabilizers, etc. Bleeding onto the surface of the film makes it easier for dust to adhere to it, and after one year, the light transmittance significantly decreases.

In order to prevent dust from adhering to bleeding plasticizers, anti-fog agents, etc. for such problems, recently, acrylic resin, fluorine-containing resin, urethane resin, polymerizable Dustproof films provided with dustproof resin coatings such as urethane acrylate resins are frequently used.

This dustproof film can prevent dust from adhering to the film surface, so that it can maintain high transparency for a long period of time, as well as a weathering stabilizer, a plasticizer, an antifogging material, etc. incorporated in the base material. Therefore, the performance such as strength and anti-fogging property can be maintained for a long period of time.

[Problems to be solved by the invention]

However, even a film provided with such a dustproof resin coating may not be able to exhibit the dustproof performance depending on the environment in which it is used.

For example, when used in an environment where the area used is surrounded by coppices such as cedar and pine, a green substance (algae) is generated on the surface of the film with the passage of time, and the light transmittance is significantly reduced.

Since this algae has strong adhesion to the film, it does not fall off due to rain, wind, etc., and does not fall off. To remove it, the only option is to wipe it off with a cloth or the like during rain or with running water, etc. It is also difficult to work.

In addition, a mechanical method is also conceivable, but the equipment becomes large-scale, so that the cost becomes enormous and the management may be squeezed.

On the other hand, from the viewpoint of the composition of the film, there is a method of preventing the adhesion of algae by mixing the copper compound into the dustproof resin film because the copper compound has a bactericidal effect, but the effect is insufficient.

An object of the present invention is to provide a synthetic resin coating material for agriculture that can prevent adhesion of algae and can maintain high transparency for a long period of time.

[Means for solving the problem]

The present inventors have conducted intensive studies to achieve the above object, and as a result, by adding a specific compound to a dust-proof resin coating provided on at least one surface of a synthetic resin film, it is possible to prevent the adhesion of algae and to increase the length. They have found that high transparency can be maintained over a period, and have completed the present invention.

That is, the present invention provides a dustproof resin film provided on at least one surface of a synthetic resin film with the following formula (1): A synthetic resin coating material for agricultural use, characterized by containing 0.05 to 10 parts by weight of an imidazole compound represented by the formula (1) based on 100 parts by weight of a film-forming resin.

As the synthetic resin film in the present invention, generally, a thermoplastic synthetic resin having a film forming property, for example, a single monomer such as vinyl chloride, ethylene, propylene, acrylate, methacrylate, vinyl acetate, vinylidene chloride, etc. Polymers, or copolymers of at least one of these monomers and other copolymerizable monomers, polyesters, polyamides, and the like, or blends of these polymers, among which, weather resistance, Light transmittance, intensity,
From the viewpoint of economy, etc., vinyl chloride resins (ie, polyvinyl chloride and its copolymer containing at least 50% by weight of vinyl chloride) and ethylene resins (ie, polyethylene and ethylene)
Preferred are copolymers containing more than 50% by weight), most preferably polyvinyl chloride.

For the production of the synthetic resin film as the base,
If necessary, resin additives such as a plasticizer, a heat stabilizer, an antioxidant, a light stabilizer, an antistatic agent, an ultraviolet absorber, an infrared absorber, an antifogging agent, a lubricant, and a pigment can be blended.

The base synthetic resin film according to the present invention is manufactured by a known film forming technique from the above composition. Known film forming techniques include calender molding, T-die extrusion, inflation molding, and melt casting.

If the thickness of this film is too thin, the strength will be insufficient, which is not preferable. Conversely, if it is too thick, it will be turned into a film, and other handling (cutting the film and joining it to a house mold, stretching it to the house frame) In general, it is appropriate to set the thickness to 0.03 to 0.5 mm, preferably 0.1 to 0.3 mm.

The agricultural synthetic resin coating material of the present invention is provided with a dust-proof resin coating on at least one surface of a base synthetic resin film produced by the above-mentioned production method, and further contains an imidazole compound represented by the above formula.

The dustproof resin coating is obtained from an acrylic resin, a fluorine-containing resin, a urethane resin, a polymerizable urethane acrylate resin, or the like.

The acrylic resin referred to herein is a polymer obtained by polymerizing mainly acrylate and methacrylate.
Specific examples of the monomer used include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and dodecyl (meth) acrylate. Yes, and vinyl acetate is also used.

The acrylic resin may be copolymerized with an internal crosslinking monomer in addition to the monomer.

As the internal crosslinking monomer, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, allyl alcohol, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate , Vinylidyl, tertiary butylaminoethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acryl glycidyl ether, itaconic anhydride, maleic anhydride, acrylamide, methacrylamide, maleamide, N-methylol acrylamide, N-methylol methacrylamide, ethylene glycol Dimethacrylate, diethylene glycol, dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, tetrahydrofurfuryl methacrylate, tetrahydrofurfuryl acrylate, 1,3-butanediol dimethacrylate, mono (2
-Methacryloylethyl) acid phosphate, trimethylolpropane trimethacrylate and the like, and these can be used alone or in combination.

Further, as the fluorine-containing resin, for example, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, polytrifluoromonochloroethylene, perfluoropropylene resin, fluoroalkoxyethylene resin or a copolymer thereof, and the above fluorine is further used. It may be a copolymer of a contained monomer and a monomer containing no fluorine (for example, a vinyl compound such as ethylene, propylene, or vinyl chloride).

As the urethane resin, for example, polyisocyanate and polyethers, polyesters, polyether / polyesters or a mixture thereof and a mixture thereof with a low molecular weight polyhydric alcohol, and further having an active hydrogen atom as necessary Polyurethanes obtained by various known methods in which a chain extender such as glycol, diamine, amyl alcohol, hydrazine and hydrogen are subjected to an isocyanate polymerization addition reaction, or polyurethane obtained by blending polyurethane with various commonly used additives Resins.

Examples of the polyisocyanates include, for example, 2,4- and 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, triphenylmethane triisocyanate, and polymethylene polyphenyl isocyanate. Aromatic polyisocyanate or hexamethylene diisocyanate, xylylene diisocyanate, methylene bis-4,
Aliphatic polyisocyanates such as 4'-diclohexyl isocyanate, ω.ω'-diisocyanate dimethylcyclohexane, and isophorone diisocyanate. These are used as one kind or as a mixture of two or more kinds.

Examples of polyethers, polyesters and polyether / polyesters include polyhydric alcohols (eg, ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol,
Sorbitol, sorbitan, etc.) ethylene oxide, propylene oxide, butylene oxide tetrahydrofuran, polyethers having a hydroxyl group at the end obtained by adding one or more alkylene oxides such as epihalohydrin, polyhydric phenols (eg, Alkylene oxide addition polymers of resorcinol, bisphenol, etc., and alkylene oxides of polycarboxylic acids (eg, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, phthalic acid, pyromellitic acid, etc.) Addition polymer, polyesters obtained by condensing the above polyhydric alcohol and polycarboxylic acid, condensate of hydroxycarboxylic acid and polyhydric alcohol (for example, castor oil fatty acid and ethylene glycol Propylene glycol, reaction products, etc.), a lactone polymer, such as polycaprolactone,
Examples thereof include those obtained by subjecting the above polyesters to addition polymerization with an alkylene oxide, and polyester / polyether having a hydroxyl group at a terminal obtained by condensing the above polyethers with a polycarboxylic acid.

The polymerizable urethane acrylate resin can be obtained by using an ethylenically unsaturated compound as the compound having an active hydrogen atom used in the polymerization reaction of the urethane resin.

Examples of the ethylenically unsaturated compound include hydroxy group-containing compounds (for example, allyl alcohol, 2-hydroxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, etc.), amino group Containing compounds (for example, monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, etc.), acrylic acid or methacrylic acid and a monoepoxy compound (for example, glycidyl (meth) acrylate,
reaction products with n-butyl glycidyl ether, allyl glycidyl ether, etc., glycidyl acrylate or glycidyl methacrylate and monocarboxylic acid-containing compounds (eg, acetic acid, butyric acid, benzoic acid, etc.), or secondary monoamine compounds (eg, dimethyl Amino, diethylamine, piperidine, methylaniline, etc.).

As the monomer polymerizable with the polymerizable urethane acrylate resin, styrene, vinyltoluene, t-butylstyrene, monochlorostyrene, α-methylstyrene,
Styrene compounds such as p-methylstyrene and divinylbenzene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate and vinyl benzoate, phenoxyethyl (meth) acrylate, isodecyl (meth) acrylate, and n-hexyl (meth) ) Acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, ethoxy (meth) acrylate, methoxyethyl (meth) acrylate, glycidyl (meth) acrylate, allyl (meth) acrylate,
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-methoxyethoxyethyl (meth) acrylate, benzyl (meth)
Acrylate, cyclohexyl (meth) acrylate,
2-hydroxyethyl (meth) acryloyl phosphate, tetrahydrofurfuryl (meth) acrylate,
1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, neopentyl glycol di (meth) Acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane di (meth)
Acrylate, 3-methylpentanediol di (meth)
(Meth) acrylate compounds such as acrylate, trimethylolpropane tri (meth) acrylate and pentaerythritol tri (meth) acrylate; unsaturated nitrile compounds such as acrylonitrile; acrylamide; α, β-unsaturated amides; diethyl fumarate And diester compounds of unsaturated polycarboxylic acids such as dibutyl maleate. These may be used alone or in combination of two or more.

In the present invention, the dustproof resin film contains an imidazole compound represented by the formula (1).

As a specific example of the imidazole-based compound, Fine Side CP-10 is commercially available from Tokyo Fine Chemical Co., Ltd.

The amount of the compound is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the film-forming resin.
３3 parts by weight.

If the amount of the above compound and the addition amount is less than 0.05 parts by weight, adhesion of algae cannot be prevented.

On the other hand, when the amount is more than the weight part, the weather resistance of the film is lowered, so that it cannot be used for a long time. Further, the dust resistance is also deteriorated, which is not preferable.

The dust-proof resin film may contain, in addition to these components, auxiliary components as required, such as a film-forming aid, a surfactant, an ultraviolet absorber, an antioxidant, a coloring agent, and a stabilizer. Can be.

As a method of forming a film of the dustproof resin, when a film is formed in a solution state, any of an aqueous dispersion and / or a solution of an organic solvent may be used, and more preferably, there is almost no possibility of dissolving the synthetic resin film. It is an aqueous dispersion.

The application of the dust-proof resin solution to the synthetic resin film,
It does not require a special device, and can be performed by a known coater such as a roll coater, a knife coater, a rod coater, a spray coater, a gravure coater, and a kiss coater.

As the drying apparatus, there are various methods such as a flash drying method, an electrothermal drying method, and an infrared heating method, and a drying apparatus suitable for the solvent used is selected. When a solution using an organic solvent is used, it is necessary to take various measures for the organic solvent.
The drying temperature is appropriately determined depending on conditions such as the dustproof resin composition, the solvent used, and the thickness of the coating.When an aqueous dispersion is used, the drying temperature is equal to or higher than the temperature at which the coating is formed, preferably 100 to 150 ° C.
It is about.

When a polymerizable urethane acrylate resin is used, a suitable method for forming a film is curing by irradiation with ultraviolet light. As a light source that causes the curing reaction, a high-pressure mercury lamp, a medium-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, a xenon lamp, an arc lamp, and the like are used.

The coating amount of the dustproof resin liquid is 0.1 to 2
An amount of 0 μm, preferably 0.3 to 10 μm is preferred.

In the case where the dustproof resin is formed as a single film without being in a solution state, a coextrusion method, an extrusion coating method, an extrusion lamination method, and a lamination method are used.

〔Example〕

 Hereinafter, the present invention will be described with reference to examples.

Reference Example 1 A vinyl chloride resin composition having the basic composition shown in Table 1 was mixed with a Henschel mixer for 10 minutes, and kneaded at 165 ° C.
Next, a film having a thickness of 0.1 mm was obtained with an L-type calender.

Reference Example 2 Preparation of Acrylic Coating Solution 100% by weight of a mixture of 59% by weight of methyl methacrylate, 33% by weight of n-butyl methacrylate, 6% by weight of hydroxyethyl methacrylate and 2% by weight of methacrylic acid, and 10% by weight of 1% aqueous potassium persulfate solution Was added dropwise to a 70 ° C. solution of 1.0 part by weight of a polyethylene oxide alkylphenyl ether derivative in 125 parts by weight of water with stirring over a period of 3 hours, and the mixture was further reacted for 3 hours to give a resin concentration of about 45%. A weight percent aqueous dispersion was obtained. This was adjusted to pH 7 with aqueous ammonia. Next, 1 part by weight of trimethylolpropane polyglycidyl ether, 5 parts by weight of butyl carbitol and 3 parts by weight of alkylphenyl ether were added to 100 parts by weight of the aqueous dispersion, and the resin concentration was adjusted with water.
It was adjusted to be 20% by weight. This solution is used as a coating solution.

Examples 1 to 3 and Comparative Examples 1 and 2 An imidazole compound [Fine Side CP-10 manufactured by Tokyo Fine Chemical Co., Ltd.] was applied to one side of the film obtained in Reference Example 1 above with the acrylic coating solution prepared in Reference Example 2. (Hereinafter abbreviated as Fineside CP-10)] in an amount shown in Table 3, and applied by a rod coater method so that the thickness of the film becomes 5 μm, and dried in an oven at 130 ° C. for 50 seconds. And a dustproof vinyl chloride resin film (hereinafter abbreviated as dustproof agricultural plastic).

Example 4 2: 1 methyl methacrylate / butyl acrylate as a binder was added to a compound having the basic composition shown in Table 1.
Using an acrylic copolymer resin copolymerized at a molar ratio of
A three-layer co-extrusion was performed with a vinylidene fluoride resin and a resin composition in which an imidazole compound (Fineside CP-10) was added to the resin in an amount shown in Table 3, and the thickness of each layer was 95 μm, 5 μm, It was melt-cast to a thickness of 5 μm to obtain a laminated film.

REFERENCE EXAMPLE 3 The ethylene-vinyl acetate copolymer composition shown in Table 2 was supplied to a T-die extruder, melted and extruded to a thickness.
A 0.1 mm film was obtained.

Example 5 One side of the film obtained in Reference Example 3 was mixed with the acrylic coating solution prepared in Reference Example 2 in an amount shown in Table 3 with an imidazole compound (Fine Side CP-10).
A 5 μm coating was provided in the same manner as described above.

Table 3 shows the results of measuring the algal resistance and weather resistance of the dustproof film obtained as described above.

Measurement method (1) Algae-proof property Seven houses with a frontage of 3 m and a length of 5 m were constructed in Nosaka-machi, Chiba Prefecture, and the films obtained in Examples and Comparative Examples were coated so that the dust-proof resin film was on the outside.

The state of adhesion of algae to each sample was visually determined.

：: No adhesion of algae was observed.

Δ: Algae is partially adhered.

X: Algae is observed on the entire surface.

(2) Weather resistance The film was mounted on an exposure test bench (installation location: Nagoya City) on a window frame with a southward slope of 30 degrees, and after a predetermined period (see Table 3), the appearance of the film was visually determined. .

：: No change.

Δ: Some brown spots are observed.

×: Many brown spots are observed.

[Effects of the Invention] The agricultural synthetic resin coating material according to the present invention has the following effects, and greatly contributes to facility horticulture.

Since the adhesion of algae can be prevented, it can be used for a long time even under a special environment.

Since the dustproof resin film is provided, high transparency can be maintained for a long time.

House management is extremely easy because the algae can be prevented from being stained.

Claims (1)

(57) [Claims] (1) A dust-proof resin film provided on at least one surface of a synthetic resin film has the following formula (1) A synthetic resin coating material for agricultural use, comprising 0.05 to 10 parts by weight of an imidazole compound represented by the formula (1) based on 100 parts by weight of a film-forming resin.