JPH0559202A - Agriculatural covering material - Google Patents

Abstract

PURPOSE:To obtain a covering material for agricultural use which retains light transmission properties and excellent fog resistance over a prolonged time period. CONSTITUTION:The title material comprises a fluororesin film and a layer of inorganic particles formed on at least one side thereof in an amount of 0.1-1.3g/m<2>, the inorganic particles consisting mainly of SiO2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agricultural coating material, and more particularly to an agricultural coating material composed of a fluorine-containing resin film.

[0002]

2. Description of the Related Art Conventionally, various agricultural coating materials made of a fluorine-containing resin film have been proposed. In these fluororesin-based films, unlike thermoplastic resins such as vinyl chloride resin, the film forming processing temperature becomes extremely high at 300 ° C. or higher, and therefore film surface modifiers such as lubricants and anti-fog agents Since it is thermally decomposed, it was impossible to add it directly into the resin.

However, when the fluorine-containing resin film is used for coating an agricultural, for example, a horticultural house, water vapor in the house condenses on the surface of the house and becomes water droplets, which drop on the agricultural products. The occurrence of disease,
There were problems such as a decrease in yield and quality.

In order to solve this problem, particles mainly consisting of Al ₂ O ₃ were applied to the surface of the film. However, these surface treatment agents have an antifogging effect when the amount applied is small. However, if a large amount is applied, the amount of light transmission of the film is reduced, so there is a problem in the amount of application and the application method.

[0005]

DISCLOSURE OF THE INVENTION The object of the present invention is to solve the above-mentioned problems which the prior art has, and has not hitherto been known. It is to propose a new agent.

[0006]

The present invention has been made to solve the above-mentioned problems, and at least one surface of a fluorine-containing resin film is provided with inorganic particles mainly composed of SiO _2.
The present invention provides a covering material for agriculture, which has an inorganic particle layer (A) applied in an amount of 0.1 to 1.3 g / m ² .

Therefore, according to the present invention, an agricultural coating material having excellent antifogging property can be obtained without impairing the light transmittance of the film. The constituent factors of the present invention will be described in detail below.

In the present invention, the "fluorine-containing resin" means
It is not particularly limited as long as it is a thermoplastic resin containing fluorine in the molecular structural formula of the resin, and specifically, for example, tetrafluoroethylene-based resin having four fluorine atoms in the resin structure, Furthermore, it is a trifluoroethylene-based resin, a difluoroethylene-based resin, a monofluorinated ethylene-based resin and a composite of these resins, and among them, a tetrafluoroethylene-based resin and a difluorinated ethylene-based resin are preferable, and A fluorinated ethylene resin is preferred.

Here, the tetrafluoroethylene-based resin is specifically, for example, tetrafluoroethylene-based resin (PTF).
E), tetrafluoroethylene / perfluoroalkoxyethylene copolymer (PFA), tetrafluoroethylene / hexafluoropropylene / perfluoroalkoxyethylene copolymer (E
PE) tetrafluoroethylene / hexafluoropropylene copolymer (FEP) and tetrafluoroethylene / ethylene copolymer (ETFE), etc., among which PFA, ETFE, FE
P and EPE are preferred, and ETFE is particularly preferred.

Explaining ETFE in detail, ethylene and tetrafluoroethylene are the main components (the molar ratio of ethylene / tetrafluoroethylene is generally 40/60 to 60/40),
If necessary, a small amount (usually 10 mol% or less) of a third comonomer component is copolymerized therewith, and in the present invention, particularly, the ethylene / tetrafluoroethylene content molar ratio is 40/60 to 60/40, preferably in the range of 45/55 to 55/45 and having the formula CH ₂ ═CH—CnF _{2n + 1} (where n
Is an integer of 2 to 10) (for example, CH ₂ ═CH—C ₄ H ₉
Or units derived from _{CH 2 = CH-C 6 -CH} 13)
ETFE having a content of 0.3 to 10 mol%, preferably 0.3 to 5 mol% is preferably used.

This ETFE is known per se, and can be produced, for example, by the method described in Japanese Patent Publication No. 59-50163, and as a commercial product, a product called "Aflon R COP" from Asahi Glass Co., Ltd. It is also possible to use those commercially available under the name.

The above trifluoroethylene resin is
Specifically, for example, trifluorochloroethylene resin (CTF)
E) and ethylene trifluoride chloride / ethylene copolymer (ECTFE), etc., among which CTEFE is preferable. The ethylene difluoride-based resin and ethylene monofluoride-based resin are, for example, vinylidene fluoride resin (PVDF) and vinyl fluoride resin (PVF).

Further, in the present invention, a mixture with another thermoplastic resin mainly containing the above-mentioned fluorine-containing resin may be used.

The "inorganic substance" of the "inorganic particles" referred to in the present invention is an inorganic substance mainly composed of SiO ₂ , and its composition is not only 100 wt% of SiO ₂ but generally 50 w.
t% or more, preferably 70 wt% or more, more preferably 80
It is more than wt%. The inorganic substance other than SiO ₂ is not particularly limited and may be any inorganic substance, for example, Al ₂ O ₃ , TiO ₂ , MgCO ₃ and CaCO _{3 and the} like, among which Al ₂ O ₃ is preferably used.

The shape of the inorganic particles is not particularly limited, but it is preferably spherical, and particles within the range of ordinary colloidal particles can be used, but the transparency of the obtained coating film is good. From the viewpoint of, the average particle size is 1 to 100
mμ, preferably 3 to 50 mμ, more preferably 5 to 30 mμ
Is.

Further, the layer A composed of the above-mentioned inorganic particles further contains a cationic, anionic, amphoteric surfactant and / or nonionic surfactant in addition to the above-mentioned inorganic substances to further prevent the fog. Sex is given. The amount of the surfactant used in the layer A is generally 0.1 to 40 wt%, preferably 0.2 to 15 wt%, more preferably 0.3 to 10 wt%. When the amount of surfactant is more than 40 wt%, the resulting coating film has poor weather resistance, durability, bleed resistance, and adhesion, and tends to have a short duration of antifogging property. Is not preferable because the antifogging property of the obtained coating film is lowered.

Examples of the cationic surfactants used herein include primary amine salts, secondary amine salts, tertiary amine salts, quaternary ammonium salts, hydroxyammonium salts,
Examples thereof include aliphatic amine salts such as ether ammonium salts and quaternary ammonium salts thereof, aromatic quaternary ammonium salts such as benzalkonium salts and bentonium salts, pyridinium salts, imidazolinium salts and fluorine-based salts.

Of these, pyridinium salt-based compounds, aliphatic amine salt-based compounds, quaternary ammonium salt-based compounds, and fluorine-based compounds are preferred, and among these, fluorine-based compounds such as perfluoroalkyl trimethyl ammonium salts and perfluoroalkyl quaternary ammonium salts. , Perfluoroalkylamine oxide, etc. are particularly preferable from the viewpoint of antifogging effect and sustainability.

Further, the anionic surfactant is not particularly limited, and for example, as a carboxylate type,
Fatty acid and rosin acid soap, N-acyl carboxylate, ether carboxylate, sulfonates such as alkyl sulfonate, sulfosuccinate, ester sulfonate, alkylallyl and alkylnaphthalene sulfonate, N-acyl Sulfonate, sulfate ester type, sulfated oil, ester sulfate, alkyl sulfate, ether sulfate, alkyl allyl ether sulfate,
Examples of the amide sulfates and phosphoric acid ester salts include alkyl phosphates, ether phosphates, alkylallyl ether phosphates, amide phosphates, formalin condensed sulfonates, and fluorine-based ones.

Of these, carboxylic acid salts, phosphoric acid ester salts, and fluorine-based ones are preferable, and among them, fluorine-based ones such as perfluoroalkylcarboxylic acid salts and perfluoroalkylphosphoric acid esters are included. And particularly preferable in terms of durability.

Examples of amphoteric surfactants include betaine-based carboxybetaine, sulfobetaine, aminocarboxylic acid salt-based, imidazoline derivative-based and fluorine-based surfactants. Among these, fluorine-based ones such as perfluoroalkyl betaine can be mentioned, and particularly preferable from the viewpoints of antifogging effect and sustainability.

As the nonionic surfactant, for example, alkyl and alkylallyl polyoxyethylene ether, alkylallyl formaldehyde condensed polyoxyethylene ether, glycerin ether and its polyoxyethylene ether, and polyoxypropylene are used as lipophilic groups. Block polymer, alkylthiopolyoxyethylene ether, propylene glycol ester polyoxyethylene ether, glycerin ester polyoxyethylene ether, sorbitan ester polyoxyethylene ether, sorbitol polyoxyethylene ether ester, glycerin ether ester , Alkyl polyoxyethylene ether ester copolymer polyoxyethylene ether ester, polyoxyethylene fat Acid ester, glycerol ester,
Sorbitan ester, dihydric alcohol ester, sucrose ester, aliphatic alkanolamide, polyoxyethylene fatty acid amide, alkanolamine ester, polyoxyester alkylamine, amine oxide, perfluoroalkylethylene oxide adduct, perfluoroalkyl oligomer and Examples thereof include fluoroalkyl ethylene oxide adducts.

Among them, alkyl and alkylallyl polyoxyethylene ethers, polyoxyethylene fatty acid esters, glycerin esters, sorbitan esters, perfluoroalkylethylene oxide adducts, perfluoroalkyl oligomers and fluoroalkylethylene oxide adducts are preferred, and particularly peroxyethylene oligomer adducts. Fluoroalkyl ethylene oxide adducts, perfluoroalkyl oligomers and fluoroalkyl ethylene oxide adducts are particularly preferable from the viewpoints of antifogging effect and sustainability.

In order to obtain the layer A on the surface of the fluorine-containing resin film of the present invention, a dispersion liquid in which the above-mentioned inorganic particles and a surfactant are once uniformly dispersed in a dispersion medium is prepared, and this is placed on the film surface. It is achieved by coating and drying.

The dispersion medium used here is not particularly limited and is appropriately selected in consideration of the inorganic particles and the surfactant to be used. Generally, for example, water, methyl alcohol, ethyl alcohol, Isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, ethyl cellosolve, ethylene glycol, acetone, glycerin, amyl acetate acetate, monoethyl ether, n-methylpyrrolidone, methyl ethyl ketone,
There are dimethylformamide, triethanolamine and the like, and among them, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, acetone and ethylene glycol are preferably used.

From the viewpoint of coating property, it is desirable that the water content is low, and the water content in the dispersion is allowed to be 4, preferably 1 in H ₂ O / SiO ₂ weight ratio. The amount of water in the dispersion is H ₂ O / S
An iO ₂ weight ratio of more than 4 is not preferable because a uniform coating film cannot be formed when the coating film is formed by coating.

The concentration of the inorganic particles in these dispersion media is not particularly limited, but is generally 50 wt% or less, preferably 5 to 30 wt%.

This dispersion medium may be further diluted to a suitable concentration before use. In particular, when an acidic organosilica sol having a pH of 5 or less is mixed with a surfactant, it is preferable because it is stable for a long period of time. In addition, such an organosilica sol is produced from a silica sol having water as a dispersion medium, for example, by the method described in Japanese Patent Publication No. 2-1087 filed earlier.

As described above, a conventionally used method can be used for applying the prepared dispersion liquid to the surface of the fluororesin film, for example, a gravure roll method, a roller touch method, a bar coater. The coating can be performed by a usual coating method such as a coating method, a spray method, a dipping method, and a brush coating method. Among these, the gravure roll method is preferable.

The amount of the inorganic particles applied on the surface of the fluororesin film is 0.1 to 1.3 g / m ² , preferably 0.1 to 1.3 g / m ² .
1.0 g / m ^2, more preferably it is important to the 0.1 to 0.5 g / m ^2. If the coating amount is less than 0.1 g / m ² , an appropriate antifogging effect cannot be obtained, and if it exceeds 1.3 g / m ² , the light transmittance is lowered, which is not preferable.

When the coating amount is within the range of the present invention, not only a remarkable antifogging effect can be obtained, but also in light transmittance,
It is surprising that the light transmittance of the raw film before being coated with the inorganic particles is equal to or slightly improved, and is surprisingly useful as a covering material for agriculture.

The agricultural coating material thus obtained is
It has excellent antifogging properties without impairing the light transmittance of the film, and is extremely large when applied to the industry. The present invention will be described in more detail with reference to the following examples, but it goes without saying that the present invention should not be limited to the examples.

[0033]

【Example】

Example A (Preparation of Inorganic Particle Dispersion) (1) Silica sol with water as dispersion medium (SiO ₂ concentration 20 w
t%, average particle diameter 11 nm, Al ₂ O ₃ / SiO ₂ = 0.002 molar ratio 1000 ml, and isopropyl alcohol (purity 99% or more) 1000 ml were mixed well and then filtered through an ultrafiltration membrane to obtain 1000 ml of filtrate. When the temperature reached, 1000 ml of fresh isopropyl alcohol was added to the mother liquor. After that, the same filtration was performed to collect 1000 ml of the filtrate. This operation in total 6
Repeated times to obtain colloidal silica with isopropyl alcohol having a silica concentration of 30 wt% as a dispersion medium. The water concentration in this sol is 2.7 wt%, the sol pH is 2.1 and the viscosity is 5.
It was 6c.p.

32 g of this colloidal silica having isopropyl alcohol as a dispersion medium and a perfluoroalkyl phosphate ester surfactant (Asahi Glass Co., Ltd .; Surflon S-11)
2, solid concentration 15%) 1 g of isopropyl alcohol 150 g
The solution diluted with was mixed with to prepare an inorganic particle dispersion liquid. (Hereinafter, this is called "dispersion liquid 1").

(2) In the same manner as in Example A- (1), colloidal silica having a concentration of SiO _{2 of} 20 wt% was prepared using ethyl alcohol as a dispersion medium. The water concentration in this sol was 1.6 wt%, the sol had a pH of 2.5, a viscosity of 1.4 cp, and an average particle size of colloidal particles of 25 nm. 32 g of colloidal silica using this ethyl alcohol as a dispersion medium, and a perfluoroalkyl petaine surfactant (Asahi Glass Co., Ltd .; Surflon S-132, solid content concentration 30%)
A solution obtained by diluting 0.3 g with 90 g of isopropyl alcohol was mixed to prepare an inorganic particle dispersion liquid. (Hereinafter, this is referred to as "dispersion liquid 2").

Example B (Preparation of Fluorine-Containing Resin Film) Examples 1-4, Comparative Examples 1-4, (Preparation of Ethylene-Tetrafluoroethylene Copolymer Film) (1) Ethylene-Tetrafluoroethylene Copolymer Polymerization of 10 mL of an internal volume autoclave, 3.46 kg of trichloromonofluoromethene, trichlorotrifluoroethane
6.52 kg, and t-butyl peroxyisobutyrate 2.38
g, then tetrafluoroethylene 1226 g, ethylene 82 g, and perfluorobutyl ethylene (CH ₂ = C
Charge 26 g of H-C ₄ F ₉ ). In this case, the reaction temperature is kept at 65 ° C. while sufficiently stirring the product to carry out the copolymerization reaction.

During the progress of the copolymerization reaction, a mixed gas having a molar ratio of tetrafluoroethylene / ethylene / perfluorobutylethylene of 53 / 46.3 / 0.7 was introduced into the system to adjust the polymerization pressure to 15.
Hold at 0 kg / cm ² . After 5 hours, 460 g of a white ethylene-tetrafluoroethylene copolymer (ETFE) was obtained. The copolymer had a C ₂ F ₄ / C ₂ H ₄ / CH ₂ ═CH ₄ CF ₉ content molar ratio of 53 / 46.3 / 0.7 and a flow starting temperature of 267
The temperature was ℃ and the heat dispersion start temperature was 360 ℃.

(2) Preparation of ETFE film The ETFE obtained in the above (1) was extrusion molded at a resin temperature of 320 ° C. to obtain a film having a thickness of 50 μ (hereinafter, this film is referred to as “film No. 1”), The physical properties are shown in Table 1.

(3) Application of inorganic particle liquid On one surface of the film No1 obtained in (2) above, discharge current 1
Corona discharge treatment was performed under the conditions of 0 A, discharge voltage 120 V, line speed 13 m / min, and then the treated surface was treated with Example A-
The dispersion liquid 1 prepared in (1) was coated with a gravure coater to obtain a film coated with inorganic particles.

The coating amount of the inorganic particles is 0.1, 0.3 and 0.5 g /
m ² film (hereinafter these films will be referred to as “film No.
2 "," Film No3 "and" Film No4 ")
For comparison and control, the coating amount of 0.05, 1.5 and 3.0 g / m ² of film (hereinafter referred to as "Film No6""FilmNo7"
And "Film No8"). The physical properties of these films are shown in Table 1.

[0041]

[Table 1]

Dispersion 2 prepared in Example A (2) was coated with a gravure coder to obtain inorganic particle coating. A film having a coating amount of the inorganic particles of 1.0 g / m ² (hereinafter, these films are referred to as “film No 5”) was obtained. The physical properties of these films are shown in Table 1.

Examples 5 to 6 (Preparation of PVF and PVDF film) As a PVF film, Tedlar 200SG4 manufactured by DuPont.
As 0TR (film thickness 50 μ) and FVDF film, KAINAR FH ₂ (film thickness 50 μ) manufactured by Mitsubishi Petrochemical Co., Ltd. was prepared.
Application was performed at g / m ² to obtain film No. 9 and film No. 10. The physical properties of these films are shown in Table 1. Table-1
The method for measuring the physical properties of the film described in 1 above and the method for evaluating the same were performed as follows.

(1) Light transmittance (%) The total light transmittance was measured according to JIS K7105.

(2) Sustainability of anti-fogging property The anti-fogging property is set to the inside, and this is coated on a beaker containing hot water of 40 ° C. and kept for 6 months as it is. Observe. "Evaluation criteria" 5-Anti-fog deteriorated area is less than 10% and completely maintains anti-fog property 4-Anti-fog deteriorated area is in the range of 10% to less than 30% 3-Anti-fog deterioration The area is in the range of 30% or more and less than 50% 2-The antifogging deterioration area is in the range of 50% or more and less than 70% 1-The antifogging deterioration area is 70% or less and there is no antifogging property thing

(3) Blocking and bleeding Each film was wound on a paper tube with a load of 250 g / 25 mm at 40 ° C. × 95.
The film is rewound after 1 week and 6 months after being placed in an atmosphere of% RH, and the blocking state and bleeding state of the film are visually observed. "Evaluation Criteria" 5-Blocking or bleeding is less than 10% 4-Blocking or bleeding is 10 or more and less than 30% 3-Blocking or bleeding is 30 or more and less than 50% 2-Blocking or bleed is 50 or more and less than 70% 1 -Over 70 blocking and bleeding

(4) Adhesiveness Cellophane tape (manufactured by Nichiban Co., Ltd.) was adhered to the inorganic particle coating layer of each film, and then the cellophane tape was peeled off so that it was at 90 degrees to the film, and the film of the coating material was coated. The degree of adhesion to was observed. This observation was carried out immediately after the film was prepared and after 6 months. "Evaluation criteria" 5-Adhesion area is less than 10% 4-Adhesion area is 10 or more and less than 30% 3-Adhesion area is 30 or more and less than 50% 2-Adhesion area is 50 or more and less than 70% 1-Adhesion area is 70 or more

[Reference Example] (Results of Cultivation of Melon) Reference Examples 1 to 4 and Comparative Reference Examples 1 to 2 October 8 Melon seeds (Aars crest) were sown in a pot, and after completion of the seeding, a tunnel was used with a gauze cloth. , Was protected from oil worms and sufficiently watered, and germinated on October 13.

In all of the pipe houses A, B, C, D, E and F (160 tsubo: frontage 5.3 m, depth 100 m, height 2.6 m), ridges (height 30 cm, width 70 cm, ridge 60 cm) were made. 120 kg / 10 are fertilized with the compound fertilizer Kanematsu 495 (sold by Kanematsu Trading Co., Ltd.) as the basic fertilizer, and the area of the ridges is covered with black mulch film (black polyethylene film: thickness 30μ). Two melon seedlings are 15 between every 10 ares.
I planted it so that it would be 00. The coating of each coating material of the pipe house was performed one week before planting. Each house was coated with the film obtained in the above example as shown in Table 2.

Mid-November: Disperse the fungicide Magnebtaisen M, and when 5 to 6 true leaves are attracted with a tape, make a three-dimensional cultivation. Drop in late November to grow to 20 to 22 true leaves. Cored Since female and male flowers bloom at this time, the box of dense bees was crossed with a dense bee set in House F. A few days after mating, the melon settled. If this fruit grows to an egg size,
Leave one fruit that is 45 to 50 cm above the ground and drip.

In early December, the fungicide Magnebtaisen M was sprayed, and a net was generated on the fruit's epidermis, so newspaper paper was hung on the bag. In the middle of December, the epidermis grew to the net for 8 minutes. do. After that, manage so that it is exposed to sunlight and spray the fungicide Magnebtaisen M in late December. Harvest started on February 10.

The evaluation items and methods for cultivation were as follows, and the results are shown in Table 2.

[0053]

[Table 2]

Evaluation items and method 1. Regarding the yield (kg / tat) and the sugar content (degree), relative values were shown with Comparative Reference Example-1 as 100.

2. Appearance (net) The harvested melons were visually inspected with the naked eye for the net condition (climbing, the number of secondary nets). ◎ Net swell is extremely high and uniform, and secondary net is extremely small. ○ Nets are highly raised and uniform, and there are few secondary nets. △ The excitement of the net is rather high, and there is a secondary net. × The swell of the net is low and there is a secondary net.

3. Diseases, insect damages Occurrences of canker, powdery mildew, aphids, etc. were visually observed. ◎ No occurrence of canker, powdery mildew and aphids is observed. ○ The occurrence of canker, powdery mildew and aphids is extremely low. △ Occurrence of canker, powdery mildew and aphids is slightly observed. × Frequent occurrence of canker, powdery mildew and aphids.

From Table-2, in the cultivation of melon with the film of the present invention, not only the yield but also the improvement of sugar content, the excellent appearance and the like of the quality are remarkably improved, and the excellent effect of controlling pests is also observed. It turns out that it is extremely excellent as a covering material for agriculture.

[0058]

Industrial Applicability According to the present invention, an agricultural coating material having an excellent antifogging property for a long period of time can be obtained without impairing the light transmittance of the agricultural coating material. By spreading the covering material for agricultural use of the present invention in a greenhouse for greenhouses, the yield is increased, the quality is improved, and the pest controlling effect is further obtained.
A practically excellent effect can be obtained.

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Claims (9)

[Claims] 1. At least one of fluorine-containing resin films
On the surface, inorganic particles mainly composed of SiO ₂ are 0.1 to 1.3 g / m ²
A covering material for agriculture, which has an applied inorganic particle layer (A layer). 2. The agricultural coating material according to claim 1, wherein the inorganic particles are applied in an amount of 0.1 to 0.5 g / m ² . 3. The SiO ₂ particles have an average particle diameter of 5 to 30 mμ.
The covering material for agriculture according to claim 1. 4. The covering material for agriculture according to claim 1, wherein the SiO ₂ particles have a spherical shape. 5. The agricultural coating material according to claim 1, wherein the A layer mainly comprises inorganic particles and a cationic and / or nonionic surfactant. 6. The agricultural coating material according to claim 1, wherein the fluorine-containing resin is a tetrafluoroethylene-based resin. 7. The ethylene tetrafluoride resin is ethylene
7. A tetrafluoroethylene copolymer (ETFE).
The agricultural coating material described. 8. The visible light transmittance of the agricultural coating material is 90.
The coating material for agriculture according to any one of claims 1 to 7, wherein the coating material is 94%. 9. The agricultural use according to claim 1, wherein the layer A is formed by coating a stable organic solvent dispersion containing colloidal silica and a surfactant having a fluoroalkyl group in the molecule. Coating material.