JP3463891B2 - Agricultural drip-proof film - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel agricultural drip-proof film, and more particularly, to a synthetic resin film surface having excellent drip-proof property and its durability, and good adhesion and transparency. The present invention relates to an agricultural drip-proof film provided with a transparent coating film.

[0002]

2. Description of the Related Art In recent years, greenhouse cultivation and tunnel cultivation using agricultural films have become popular.
In such cultivation, when spreading and using the agricultural film, as a method for preventing fogging due to adhesion of water drops on the inner surface, a method of spray-applying a drip-proofing agent (anti-fog agent) has been generally used after spreading. . However, the drip-proofing agent used in this case lacks drip-proof durability, and is usually 1
There is a drawback that the drip-proof effect is lost in about a year. When the drip-proof effect is lost, recoating must be performed, and there is a problem that agricultural work cannot be performed during this period.

[0003]

Under the circumstances, the present invention has an excellent drip-proof property and its durability, and also has a good drip-proof property after freezing the inner surface of the film in the winter season. The purpose of the present invention is to provide a drip-proof film.

[0004]

Means for Solving the Problems As a result of intensive studies to develop an agricultural drip-proof film having improved properties, the present inventors have found that colloidal silica particles are provided on one side of a synthetic resin film. The one provided with a water-based acrylic modified urethane resin coating film containing layer has excellent drip-proof property and its durability, and also has good drip-proof property after freezing the inner surface of the film in winter, and the coating film. The layer was found to be excellent in adhesion and transparency, and the present invention was completed based on this finding.

That is, according to the present invention, an aqueous acrylic-modified urethane resin coating layer containing colloidal silica particles is provided on one side of a synthetic resin film with an aqueous acrylic-modified urethane.
Resin, colloidal silica particles, polyether modified silico
Water-based emmer containing 0.1 to 5% by weight of a surface-active agent
A drip-proof film for agriculture, which is characterized in that it is provided by applying a solution composition and drying it .

In the agricultural drip-proof film of the present invention,
There is no particular limitation on the synthetic resin film used as the base material, and any one conventionally selected as an agricultural film, such as a polyethylene terephthalate film, a polyvinyl chloride film, or a polyolefin film, may be selected. Can be used.

In the present invention, it is necessary to form a drip-proof coating film, that is, an aqueous acrylic modified urethane resin coating film layer containing colloidal silica particles on one side of these synthetic resin films. The water-based acrylic modified urethane resin used for the drip-proof coating is preferably a polyester-based anionic one, and such a polyester-based anionic water-based acrylic-modified urethane resin is, for example, (A) polyester-based anionic resin. It can be produced by polymerizing the (B) hydroxyl group-containing acrylic compound in the presence of the aqueous urethane resin, and then reacting with the (C) active isocyanate compound.

The method for producing the polyester-based anionic aqueous urethane resin as the component (A) is not particularly limited, and is a conventionally known method such as (1) a method using a chain extender having an anionic group, (2) ) Use any method selected from a method of blocking isocyanate groups and chain extension at the time of regeneration, (3) prepolymer mixing method, (4) method of chain extension of an anionic group-containing prepolymer, etc. You can

In the method (1) using a chain extender having an anionic group, first, a bifunctional terminal hydroxyl group-containing polyester diol and a diisocyanate compound are reacted by a known method to form a urethane prepolymer.

Examples of the polyester diol used at this time include aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid and dodecanedioic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and decalindicarboxylic acid, isophthalic acid, Dibasic acids such as aromatic dicarboxylic acids such as terephthalic acid and naphthalene dicarboxylic acid, and ethylene glycol, diethylene glycol,
Examples thereof include those obtained by reaction with diols such as propylene glycol, butanediol, hexanediol, neopentyldiol, and polyvalerolactone diol and polycaprolactone diol. This polyester diol preferably has a molecular weight of 500 to 3000.

On the other hand, examples of the diisocyanate compound include aromatic diisocyanate compounds such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and naphthylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, norbornene diisocyanate, and the like. Examples thereof include aliphatic diisocyanate compounds such as cyclic diisocyanate compounds and hexamethylene diisocyanate, and further diisocyanate compounds masked with caprolactam, phenol, lower alcohols and the like.

Next, a chain extender having an anionic group is reacted with the urethane prepolymer in an organic solvent, and then water is added and the organic solvent is distilled off or reacted in an aqueous medium. Thus, an anionic polyurethane emulsion is produced.

Examples of the chain extender having an anionic group used at this time include diols and diamines having a free or salt type carboxyl group or sulfonic acid group. Specific examples of such diols and diamines include 2-carboxy-2-methylpropane-
1,3-diol, 2-sulfobutane-1,4-diol, 1-carboxypentamethylenediamine, N- (2
-Carboxyethyl) ethylenediamine, N- (2-sulfoethyl) ethylenediamine, N- (3-sulfopropyl) ethylenediamine, 2-carboxyphenyl-
Examples thereof include 1,4-diamine and carboxylates and sulfonates thereof.

In the method (2) of blocking the isocyanate group and extending the chain at the time of regeneration, first, a urethane prepolymer is prepared in the same manner as in the case of the above (1), and then sodium bisulfite is used, for example. The isocyanate groups at both ends of the prepolymer are blocked to induce hydrophilic carbamoyl sulfonate groups. Then
In the aqueous medium, this blocked urethane prepolymer is regenerated and at the same time, reacted with the chain extender exemplified in (1) above to produce an anionic polyurethane emulsion.

In the prepolymer mixing method (3), first, a urethane prepolymer is prepared in the same manner as in the above (1), and then reacted with a diol having a carboxyl group, triethanolamine is added, and an ionomer is added. Let it form. Next, this is added to an aqueous medium to form an emulsion, and then diamine or diol is further added to extend the chain to produce an anionic polyurethane emulsion.

In this case, examples of the diamine used as the chain extender include isophoronediamine, hexamethylenediamine, xylylenediamine and the like, and examples of the diol include ethylene glycol, diethylene glycol, propylene glycol and butanediol. Hexanediol and the like can be mentioned.

In the method (4) of chain-extending a prepolymer having an anionic group, first, a prepolymer having an anionic group is formed, and the diamine or diol exemplified in (3) above is produced in this prepolymer. The chain extender is reacted in an organic solvent, and then water is added to distill off the organic solvent, or the reaction is carried out in an aqueous medium to produce an anionic polyurethane emulsion.

As the prepolymer having an anionic group, for example, a prepolymer having a sulfonic acid group or a salt type sulfonic acid group formed by sulfonation of an aromatic ring of a urethane prepolymer obtained from a polyester diol and an aromatic diisocyanate compound. A prepolymer obtained from a polymer, polyester diol or polycarbonate diol, and an aromatic diisocyanate compound having a sulfonic acid group or a salt-type sulfonic acid group, and a trifunctional carboxylic acid such as trimellitic anhydride are reacted with a diol. Examples thereof include a prepolymer obtained from a polyester diol having a carboxyl group or a salt type carboxyl group and a diisocyanate compound.

The polyester type anionic aqueous urethane resin as the component (A) may be used alone or in combination of two or more kinds. Examples of the hydroxyl group-containing acrylic compound as the component (B) include hydroxyethyl acrylate, hydroxyethyl methacrylate, and a condensate of polyhydric alcohol and acrylic acid or acrylic acid ester, methacrylic acid or methacrylic acid ester, and the like. To be Specific examples of the polyhydric alcohol include ethylene glycol, diethylene glycol,
Propylene glycol, dipropylene glycol, 1,
Examples thereof include 4-butylene glycol, 1,3-butylene glycol, 1,6-hexamethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, glycerin and polyester polyol. Specific examples of acrylic acid ester and methacrylic acid ester include methyl acrylate, ethyl acrylate, acrylate-n-butyl, isopropyl acrylate, methyl methacrylate, ethyl methacrylate, methacrylic acid-n-butyl, isopropyl methacrylate. And so on.

The hydroxyl group-containing acrylic compound as the component (B) may be used alone or in combination of two or more kinds. Moreover, you may use together with the radically polymerizable monomer which does not contain a hydroxyl group. Examples of the radically polymerizable monomer include various acrylic acid esters, various methacrylic acid esters, styrene, vinyl acetate, acrylonitrile and the like.

In the present invention, the polyester-based anionic water-based acrylic modified urethane resin which is preferably used is obtained by adding the hydroxyl group-containing component (B) in the presence of the polyester-based anionic water-based urethane resin (A). It can be obtained by polymerizing an acrylic compound using a radical polymerization initiator and then reacting the active isocyanate compound of the component (C). Examples of the active isocyanate compound as the component (C) used in this case include trimethylolpropane, glycerin, 1,3-butanediol, ethylene glycol, polyether polyol, polyester polyol, propylene glycol, dipropylene glycol, in addition to the diisocyanate compound. A compound of the terminal isocyanate group adduct type obtained by reacting, etc., a compound of the terminal isocyanate group obtained by the cyclic trimerization of a diisocyanate compound, a compound of a burette type terminal isocyanate group obtained by the reaction of a diisocyanate compound and water And the like, and glycols such as ethylene glycol and its ethylene oxide adduct are reacted by a known method. The active isocyanate compound as the component (C) may be used alone or in combination of two or more.

In the present invention, a coating layer of the aqueous acrylic modified urethane resin containing colloidal silica particles is formed on one side of the synthetic resin film. The coating layer is formed by the following method. Is preferably used.

First, the water-based acrylic modified urethane resin and the colloidal silica particles are mixed in a weight ratio of 3: 7 to 7:
An aqueous emulsion composition containing about 3 to about 3% by weight and, if desired, about 0.1 to 5% by weight of a polyether-modified silicone surfactant is prepared. The colloidal silica particles preferably have an average particle size in the range of 5 to 200 nm, and if the average particle size deviates from the above range, the effect of the present invention will not be sufficiently exhibited. Further, even if the weight ratio of the aqueous acrylic modified urethane resin and the colloidal silica particles deviates from the above range, the effect of the present invention is not sufficiently exhibited.

Further, the aqueous acrylic modified urethane resin and colloidal silica particles are preferably used so that the total content thereof is 10 to 40% by weight based on the total amount of the composition. Further, the polyether-modified silicone-based surfactant optionally used has an effect of further improving the drip-proof property (anti-fogging property) and its durability, and the amount thereof is 0.1% by weight based on the total amount of the composition. If it is less than%, the effect of improving the drip-proof property and its sustainability is not sufficiently exhibited, and if it exceeds 5% by weight, the effect is not improved for the amount used, which is economically disadvantageous.

The composition may contain various conventionally known additives such as antifogging agents, dispersants, stabilizers and crosslinking agents, within a range that does not impair the object of the present invention. it can. Further, a hindered amine-based light stabilizer, an ultraviolet absorber or the like may be contained in order to enhance the weather resistance of the coating film. The cross-linking agent is used especially for improving the water resistance of the coating film, and examples thereof include epoxy type and aziridine type.

To form this coating film, a dipping method or a coating method using a gravure coater, a reverse roll coater, an air knife coater or the like is used to apply the composition to one side of the synthetic resin film, and then 50 to 50 Drying with hot air at a temperature of about 150 ° C. may form a coating film having a film thickness of 0.2 to 5 μm, preferably about 0.5 to 2 μm. The outer surface of the agricultural drip-proof film of the present invention can be subjected to a conventional treatment such as a dustproof treatment, if desired.

[0027]

The agricultural drip-proof film of the present invention is provided with a drip-proof coating layer having good adhesion and transparency on the surface thereof, and is excellent in drip-proof property and its durability. At the same time, it has a good drip-proof property after freezing the inner surface of the film in winter, and is suitably used as a covering material for greenhouse greenhouse cultivation and tunnel cultivation.

[0028]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. The performance of the drip-proof film was determined as follows.

(1) Transparency Suga Tester, haze meter was used to measure the haze value for evaluation. ○ (good): 0 to 3%, △ (somewhat inferior): more than 3% to 5
%, X (inferior): over 5%

(2) Adhesion Peeling test with cellophane tape ○: Peel off, △: Partial peeling, ×: Full surface peeling

(3) Initial drip-proof and sustainability Water temperature 40 ° C., outside air temperature 5-10 ° C. 30 ° inclination on a water tank
The film was spread with and the initial drip-proof property and durability were evaluated according to the following criteria. Initial drip-proof property: ◯: Flows without water droplets less than 30 minutes after spreading, Δ: Flows without water droplets 30 to 60 minutes after spreading, ×: Water droplets adhered more than 60 minutes and less than 90 minutes after spreading Sustainability without flowing; ○: The entire surface of the film flows without water droplets attached.
Δ: About 50% of the film flows without water droplets attached, ×:
Water drops adhere to almost the entire surface of the film

(4) Drip-proof property after freezing At the experimental field in Ageo City, Saitama Prefecture, the film has a frontage 1
The film was spread in a tunnel-type house having a height of 80 m and a height of 80 cm, and the drip-proof property after the inner surface of the film was frozen in the early morning of winter (January to February 1994) was evaluated. ◯: The entire surface flows well, Δ: Water drops adhere to about 20% area, ×: Water drops adhere to about 50% or more

Example Anionic acrylic modified polyurethane emulsion [Bontaiter-HUX-401: manufactured by Asahi Denka Kogyo KK,
Trade name] 40 parts by weight, colloidal silica [Snowtex 20: Nissan Chemical Industries, Ltd., trade name, average particle size 15
nm, water dispersion] 60 parts by weight and polyether-modified silicone surfactant [L-77: manufactured by Nippon Unicar Co., Ltd.,
Trade name] 0.5 part by weight of a drip-proof coating film forming composition was prepared.

Next, the above composition was applied to one side of a polyethylene terephthalate film having a thickness of 0.165 mm by a gravure coater (gravure roll: 160 mesh) and dried at 120 ° C. to form a coating film, which was dripproof for agriculture. A sex film was made and its performance was evaluated. The results are shown in Table 1.

Comparative Examples 1 to 4 For forming a drip-proof coating film in the same manner as in Examples except that the following anionic polyurethane emulsion was used in place of the anionic acrylic modified polyurethane emulsion. The composition was prepared to make an agricultural drip-proof film. The performance is shown in Table 1.

Anionic Polyurethane Emulsion Comparative Example 1 Neotan UE-1402 [trade name, manufactured by Toagosei Chemical Industry Co., Ltd.] Comparative Example 2 Neotan UE-2103 [trade name, manufactured by Toagosei Chemical Industry Co., Ltd.] Comparative Example 3 Bontaita-HUX-320 [Asahi Denka Kogyo KK, trade name] Comparative Example 4 Superflex 107 [Daiichi Kogyo Seiyaku KK, trade name]

[0037]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) A01G 13/02 A01G 9/14

Claims (5)

(57) [Claims] On one side of the 1. A synthetic resin film, a water-based acrylic-modified urethane resin coating layer containing colloidal silica particles, water-based acrylic-modified urethane resin, colloidal sheet
Rica particles, polyether modified silicone surfactant
An aqueous emulsion composition containing 0.1 to 5 wt%
An agricultural drip-proof film characterized by being applied and dried . Wherein the aqueous emulsion composition, an aqueous acrylic-modified urethane resin and colloidal silica particles, weight ratio of 3: 7 to 7: Drip agricultural according to claim 1, wherein those having free at 3 Sex film. 3. The agricultural drip-proof film according to claim 1, wherein the water-based acrylic modified urethane resin is a polyester-based anionic resin. 4. A water-based acrylic modified urethane resin,
(A) in the presence of a polyester-based anionic aqueous urethane resin, (B) a mixture was allowed to polymerize the hydroxyl group-containing acrylic Le compound, according to claim 3, wherein those made by reacting (C) the active isocyanate compound Agricultural drip-proof film. 5. The colloidal silica particles have an average particle size of 5 to 5.
The agricultural drip-proof film according to any one of claims 1 to 4, which has a thickness of 200 nm.