JPH01301246A - Agricultural synthetic resin coating material - Google Patents

Abstract

PURPOSE:To prevent the fouling of algae and to keep high transparency for a long period of time, by containing a specific isothiazoline compound in the dustproof resin film provided on at least the single surface of a synthetic resin film. CONSTITUTION:An isothiazoline compound represented by formula (I) is contained in the dustproof resin film provided to at least the single surface of a base synthetic resin film pref. in an addition amount of 0.05 to 10% per 100pts.wt. of the film forming resin, more pref., in the addition amount of 0.1 to 3%. When the addition amount is less than 0.05%, the fouling of algae can not be prevented. When the addition amount exceeds 10%, this film becomes impossible to use over a long period of time because the weatherability of the film is lowered and dustproofness is also deteriorated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an agricultural coating material, and particularly to an agricultural synthetic resin coating material that can prevent algae from adhering and can maintain high transparency for a long period of time.

[Prior Art] In recent years, in order to increase the marketability and productivity of agricultural crops through forced, semi-forced or suppressed cultivation, so-called greenhouses have been developed in which useful plants are grown under agricultural covering materials such as agricultural vinyl films. Cultivation and tunnel cultivation are widely practiced.

The synthetic resin coating materials currently used in greenhouse cultivation and tunnel cultivation, such as vinyl chloride resin films, contain plasticizers, antifogging agents, stabilizers, etc., but these additives wear off over time. As the film surface bleeds, dust tends to adhere to it, and the light transmittance decreases significantly over a period of -2 years.

In order to prevent dust from adhering to the bleed plasticizer, antifogging agent, etc., recently, acrylic resins, fluorine-containing resins,
Dustproof films coated with dustproof resins such as urethane resins and polymerizable urethane acrylate resins are often used.

This dustproof film suppresses the adhesion of dust to the film surface, allowing it to maintain high transparency over a long period of time.In addition, the film contains weather stabilizers, plasticizers, antifogging agents, etc. contained in the base material. Since the loss of water is also suppressed, it is possible to maintain performance such as strength and anti-fogging properties over 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 its dustproof performance depending on the environment in which it is used.

For example, if the film is used in an environment surrounded by thickets of cedar, pine, etc., green substances (algae) will form on the surface of the film over time, significantly reducing the light transmittance.

Since this algae has a strong adhesion to the film, it does not wash away due to rain or wind, and the only way to remove it is to wipe it off with a cloth or the like during rain or while running water.

This type of work must be performed over the entire surface of the film, and is therefore difficult to perform.

Mechanical methods can also be considered, but they require large-scale equipment, which can lead to enormous costs and put pressure on management.

On the other hand, from the viewpoint of the film composition, since copper compounds have a bactericidal effect, there is a method of mixing the copper compounds into the dust-proof resin coating to prevent the adhesion of algae, but the effect is insufficient.

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

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the present inventors found that by incorporating a specific compound into the dust-proof resin coating provided on at least one side of a synthetic resin film, it is possible to prevent algae from adhering to the film and to maintain a long-lasting effect. It was discovered that high transparency can be maintained over a period of time, and the present invention was completed.

That is, the present invention requires that the dustproof resin coating provided on at least one side of the synthetic resin film contain an isothiazoline compound represented by the following formula (R: alkyl group).
This is an agricultural synthetic resin covering material with f characteristics.

The synthetic resin film in the present invention generally includes thermoplastic synthetic resins having film-forming ability, such as monomers such as vinyl chloride, ethylene, propylene, acrylic esters, methacrylic esters, vinyl acetate, and vinylidene chloride. homopolymers, copolymers of at least one of these monomers with other copolymerizable monomers, polyesters, polyamides, etc., or blends of these polymers. □Light transmittance, intensity,
Vinyl chloride resin (i.e., polyvinyl chloride and its copolymer containing 50% or more of vinyl chloride) from the viewpoint of economic efficiency, etc.
and ethylene-based resins (polyethylene and its copolymers containing 50% by weight or more of ethylene) are preferred, most preferably polyvinyl chloride.

In the production of the above-mentioned synthetic resin film as a base, resin additives such as plasticizers, heat stabilizers, antioxidants, light stabilizers, antistatic agents, ultraviolet absorbers, far-infrared absorbers, Antifogging agents, lubricants, pigments, etc. can be added.

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

If the thickness of this film is too thin, the strength will be insufficient, so it is undesirable.On the other hand, if it is too thick, it will be difficult to make the film into a film, and other handling (cutting the film and joining it into a house shape, spreading it on the frame of the house) (including work to do)
Normally, 0.03~O, Sun, etc.
Preferably, the order of 0.1 to 0.3 is appropriate.

The agricultural synthetic resin coating material of the present invention has a dustproof resin coating on at least one side of the base synthetic resin film produced by the above production method, and further contains an isothiazoline compound represented by the above formula.

Dust-proof resin coating is made of acrylic resin, fluorine-containing resin,
It is obtained from urethane resin, polymerizable urethane acrylate resin, etc.

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

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

Internal crosslinking monomers include 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, vinyl pyridine, tert-butylaminoethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acrylic 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, etc., which may be used alone or in combination.

Examples of fluorine-containing resins include polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene,
Polytrifluoromonochloroethylene, perfluoropropylene resin, fluoroalkoxyethylene resin, or copolymers thereof, and the above-mentioned fluorine-containing monomers and non-fluorine-containing monomers (e.g., ethylene, propylene, vinyl chloride) It may also be a copolymer with a vinyl compound such as

Examples of urethane resins include polyisocyanates, polyethers, polyesters, polyethers/polyesters, mixtures thereof, mixtures of these and low-molecular polyhydric alcohols, and optionally those having active hydrogen atoms. Polyurethanes obtained by various known methods of isocyanate polymerization addition reaction with chain extenders such as glycols, diamines, amyl alcohols, hydrazine, and hydrogen, or polyurethanes obtained by blending various commonly used additives with polyurethanes. Resin can be given.

Examples of the polyisocyanes Vt include 2.4- and 2.6-tolylene diisocyanate, 4.4-diphenylmethane diisocyanate, [,5-naphthylene diisocyanate, triphenylmethane triisocyanate, and polymethylene polyphenyl. Aromatic polyisocyanates such as isocyanate, hexamethylene diisocyanate, xylylene diisocyanate, methylene bis-4,4゛-cyclohexyl isocyanate, ω.
Examples include aliphatic polyisocyanates such as ω''-diisocyanate, dimethylcyclohexane isophorone diisocyanate, etc. These may be used alone or as a mixture of two or more.

Also polyethers, polyesters, polyethers,
Examples of polyesters include polyhydric alcohols (e.g., ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, etc.), ethylene oxide,
Polyethers and polyhydric phenols (e.g., resorcinol, bisphenol, etc.) having hydroxyl groups at the terminals obtained by adding one or more alkylene oxides such as propylene oxide, butylene oxide, tetrahydrofuran, and shrimp herrohydrin. Alkylene oxide addition polymers, polycarboxylic acids (e.g., maleic acid, fumaric acid, succinic acid, glucuric acid,
Adipic acid, azelaic acid, sebacic acid, phthalic acid,
pyromellitic acid, etc.), polyesters obtained by condensing the above-mentioned polyhydric alcohols and polycarboxylic acids, condensates of hydroxycarboxylic acids and polyhydric alcohols (such as castor oil M'S reaction products of acids and ethylene glycol, propylene glycol, etc.), lactone polymers such as caprolactone, addition polymerization of alkylene oxide to the above polyesters, condensation of the above polyethers and polycarboxylic acids. Examples include polyesters and polyethers having hydroxyl groups at the ends obtained by

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

The ethylenically unsaturated compounds mentioned here 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 (e.g., monomethylaminoethyl (meth)acrylate, monoethylaminoethyl (meth)acrylate, etc.), acrylic acid or methacrylic acid and monoepoxy compounds (e.g., glycidyl (meth)acrylate, butyl glycidyl ether, allylglycidyl reaction products of glycidyl acrylate or glycidyl methacrylate with monocarboxylic acid-containing compounds (e.g. acetic acid, butyric acid, benzoic acid), or secondary monoamine compounds (e.g. dimethylamine, diethylamine, piperidine, methyl Examples include reaction products of aniline, etc.).

Monomers that can be polymerized with the polymerizable urethane acrylate resin include styrene, vinyltoluene, t-butylstyrene, monochlorostyrene, α-methylstyrene, p-
~ Styrene compounds such as methylstyrene and divinylbenzene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinylbenzene/soyneed, phenoxyethyl (meth)acrylate,
Isodecyl (meth)acrylate, 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,
■.

4-butanediol di(meth)acrylate, L6-hexanethiol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tribrobylene glycol di(meth)acrylate (meth)acrylate, trimethylolpropane di(meth)acrylate, 3-methylbentanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate
(meth)acrylate compounds such as acrylate,
Examples include unsaturated nitrile compounds such as acrylonitrile, acrylamide, α, β-unsaturated amides, diester compounds of unsaturated polycarboxylic acids such as diethyl fumarate, and dibutyl maleate. These may be used alone or in combination of two or more.

(R: alkyl group) The isothiazoline compound shown in is included.

The amount of the above-mentioned compound added is preferably 0.05x to 10x, more preferably 0.1x to 3x per 100 parts by weight of the film-forming resin.

If the amount of the above compound added is less than 0.05χ, adhesion of algae cannot be prevented.

On the other hand, if it exceeds 10χ, the weather resistance of the coating will decrease, making it impossible to use it for a long period of time. Further, the dust resistance is also deteriorated, which is not preferable.

In addition to these components, the dust-proof resin coating may contain auxiliary components, such as film-forming aids, surfactants, ultraviolet absorbing agents, antioxidants, colorants, stabilizers, etc., as necessary. I can do it.

As for the method of forming the film of the dust-proof resin, when forming the film in a solution state, either an aqueous dispersion and/or an organic solvent solution may be used, and it is more preferable that there is little risk of dissolving the synthetic resin film. It is an aqueous dispersion.

The application of the dustproof resin solution to the synthetic resin film does not require any special equipment, and can be carried out using a known coater such as a roll coater, knife coater, rotary coater, spray coater, gravure coater, or kiss coater.

There are many types of drying equipment, such as flash drying, electric heating drying, and infrared heating, but the one that suits the solvent used is selected. In addition, when using a solution using an organic solvent,
It is necessary to take various measures against organic solvents. The drying temperature is determined as appropriate depending on the dustproof resin composition, the solvent used, the coating thickness, etc. When an aqueous dispersion is used,
The temperature is at least the temperature at which the film is formed, preferably about 100°C.

In addition, as a film forming method when using a polymerizable urethane acrylate resin, curing by ultraviolet irradiation is appropriate. As a light source for causing this 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, etc. are used.

The amount of dustproof resin liquid to be applied is such that the thickness of the film after drying is 0.1~
An amount of 20 μm, preferably 0.3 to 10 μm is preferred.

In addition, when forming the above-mentioned dustproof resin as an independent coating without forming it in a solution state, coextrusion method, extrusion coating method,
Extrusion lamination method and lamination method are used.

〔Example] The present invention will be explained below with reference to Examples.

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

Reference Example 2 Preparation of acrylic coating liquid Methyl methacrylate 59% by weight, rope tyl methacrylate 33% by weight, hydroxyethyl methacrylate 6%
% by weight and 100 parts by weight of a mixture of methacrylic acid double tχ and 1.0 parts by weight of a polyethylene oxide alkyl phenyl ether derivative were dissolved in 125 parts by weight of water at 70°C.
It was added dropwise to the solution over 3 hours with stirring, and the mixture was reacted for an additional 3 hours to obtain an aqueous dispersion having a resin concentration of about 45% by weight. This was adjusted to pH 7 with aqueous ammonia, and then 1 part by weight of trimethylolpropane polyglycidyl ether, 5 parts by weight of butyl calpitol, and 3 parts by weight of alkylphenyl ether were added to 100 parts by weight of this aqueous dispersion. The resin concentration was adjusted to 20% by weight with water. This solution is used as a coating liquid.

Examples 1 to 3, Comparative Examples 1 to 2 On one side of the film obtained in Reference Example 1 above, an isothiazoline compound was added to the acrylic coating solution prepared in Reference Example 2 in the amount shown in Table 3, and the thickness of the film was determined. It was coated using a rod coater method so that it had a thickness of 5 μm, and was dried in an oven at 130° C. for 50 seconds to obtain a dustproof vinyl chloride resin film (hereinafter abbreviated as dustproof vinyl).

Example 4 Adding 2:l of methyl methacrylate/butyl acrylate as a binder to a compound having the basic composition shown in Table 1.
Using an acrylic copolymer resin copolymerized at a molar ratio of
Three layers were coextruded with a polyvinylidene fluoride resin and a resin composition in which an isothiazoline compound was added to the resin in an amount shown in Table 3, and the thickness of each layer was 95 mm.
A laminated film was obtained by melt casting to a thickness of 5 μm and 5 μm.

Reference Example 3 The ethylene-vinyl acetate copolymer composition shown in Table 2 was
-Feed to die extruder and melt extrude to 0 thickness
．． A 1 m film was obtained.

Example 5 On one side of the film obtained in Reference Example 3, an isothiazoline compound was added to the acrylic coating solution prepared in Reference Example 2 in the amount shown in Table 3, and a 5μ-cut film was prepared in the same manner as in Example I. has been established.

Table 3 shows the results of measuring the anti-algae properties and weather resistance of the dust-proof film obtained above.

Measurement method (1) Algae resistance Seven greenhouses with a frontage of 3 and a length of 5 m were constructed in Otaki-cho, Chiba Prefecture, and the films obtained in the Examples and Comparative Examples were coated with the dust-proof resin coating on the outside. .

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

O: No adhesion of algae was observed.

Δ: Adhesion of algae is observed.

×: Adhesion of algae is observed on the entire surface.

Table 3 *: Amount added to the resin content (2) The weather-resistant film was attached to a window frame-shaped exposure test stand (installation location: Nagoya type) with a 30 degree slope facing south, and the specified period (see Table 3) elapsed. Afterwards, the appearance of the film was visually judged.

○: No change.

Δ: Some brown spots are observed.

×: Brown spots are observed.

〔Effect of the invention〕

The agricultural synthetic resin coating material according to the present invention has the following effects and greatly contributes to greenhouse horticulture.

■Since it prevents algae from attaching, it can be used for a long period of time even under special environments.

■Dust-proof resin 'mM is provided, so high transparency can be maintained over a long period of time.

■ House management is extremely easy as stains caused by algae can be prevented.

Claims (1)

[Claims] 1. A dustproof resin coating provided on at least one side of a synthetic resin film contains an isothiazoline compound represented by the following formula ▲ Numerical formula, chemical formula, table, etc. ▼ (R: alkyl group) An agricultural synthetic resin covering material characterized by: