TWI425061B - Light-shielding agent for agriculture - Google Patents

Description

Agricultural sunscreen

The present invention relates to an agricultural sunscreen agent suitable for agricultural film used in greenhouse cultivation or tunnel shed cultivation.

Regarding greenhouse cultivation or tunnel shed cultivation, crops cultivated in agricultural film greenhouses often have too much sunlight to pass through, and have adverse effects such as daily burning on crops. In particular, in order to prevent the occurrence of daily burning in summer crops, it is generally used to cover the agricultural greenhouse with a light-shielding net (film) to shield the light, or to disperse inorganic substances such as lime in water, and spray it on the agricultural film greenhouse to form an inorganic film. Eli shading method.

However, for example, in a method in which a light-shielding net (film) is coated on an agricultural film greenhouse, the cost of the light-shielding net is high, and it is difficult to install and disassemble, which is labor-intensive. Further, in the method of forming a film of an inorganic substance such as lime to provide light shielding, it is difficult to uniformly apply a light-shielding film on the film, and a film of an inorganic substance such as lime is likely to be lost due to rain, and it is necessary to apply it repeatedly.

Recently, it has been proposed to spray a pigment-containing light-shielding paint (light-shielding paint) on a film for agricultural use, and to form a light-shielding coating film on the film to provide light-shielding (Patent Document 1). Dispersing the opaque coating ̇ The method of applying the enamel coating to the agricultural film is to use a pigment-containing white water-based latex coating which has been adjusted to a specific viscosity, and the opaque coating film is excellent in the film, but the durability of the coating film is not good, and It is not easy to remove the film.

When the light-shielding coating film is not used, it is necessary to remove the light-shielding paint applied to the film. However, the formulation of the latex paint forming the coating film is not a composition that can be arbitrarily removed. For example, when the sun shines in the greenhouse in winter, The light-shielding coating film is removed by a strong removal liquid or an organic solvent containing a surfactant, or a new agricultural film must be used.

Patent Document 1 JP-A-2002-119148

In view of the above-described problems, the object of the present invention is to provide an agricultural sunscreen agent as an opacifier applied to an agricultural resin film, and when an inorganic film forming a white pigment on the surface of an agricultural greenhouse is shielded from light, it is not easy to form rain or the like. The agricultural sunscreen which has a light-shielding coating film and has a light-shielding coating film and can be easily removed by an alkaline removing agent when not in use.

In order to solve the above problems, the present inventors have found that using a resin latex as a binder and mixing two inorganic materials having different particle diameters as an inorganic film coated on an agricultural greenhouse film, when a light shielding layer is formed, A light-shielding coating film which can be easily removed by an alkali removal liquid when it is water-repellent, such as rainwater, is used.

Further, the present inventors have found that when a film for use in an agricultural ethylene greenhouse is a vinyl chloride resin film, an acrylic resin obtained by polymerizing a hydroxyl group-containing monomer is coated on the surface of the film to form a coating film, and an inorganic substance derived from a white pigment The hydrogen resin emulsion forms an agricultural sunscreen which can be easily removed by using an alkali remover, and when the sunscreen is applied to form a light shielding layer, it is possible to obtain a light-shielding which is excellent in persistence over a long period of time and which can be removed by an alkali remover when not in use. Coating film.

When the vinyl resin film or the olefin resin is used as the agricultural resin film, the inventors have found that when the agricultural resin film containing the hindered amine compound in the resin film is used, the light-shielding coating film of the light-shielding agent is applied to the surface of the film. It retains its persistence after a long period of time, and can be alkalined when not in use. The light-shielding coating film is easily removed by the removing agent.

The present invention has been completed on the basis of the above novel findings.

Therefore, the first aspect of the present invention is a light-shielding coating liquid composed of an inorganic material, a resin latex, and water as an aqueous solvent, and is characterized in that the ratio of the resin component to the inorganic material is 1:0.3 to 1:15, and the inorganic substance Two kinds of inorganic materials such as an inorganic material having an average particle diameter of less than 1 μm and an average particle diameter of 1 μm or more are used, and an inorganic material having an average particle diameter of less than 1 μm: an inorganic material having an average particle diameter of 1 μm or more is a light-shielding coating in a range of 1:0.5 to 2. A liquid sunscreen agent composed of liquid.

According to a second aspect of the present invention, at least one surface of an agricultural vinyl chloride resin film coated with a light-shielding agent is coated with an acrylic resin obtained by copolymerization of a hydroxyl group-containing monomer to form a coating film, and is composed of an inorganic material and a resin latex. The light-shielding layer is formed by coating the surface of the coating film, and the formed light-shielding layer can be removed by an alkaline remover.

The third aspect of the present invention is applied to an agricultural resin film containing a hindered amine compound, and is composed of an inorganic material and a resin latex, and the formed light-shielding layer can be removed by an alkaline remover.

Specifically, when the agricultural resin film is a vinyl chloride resin film for agricultural use, it contains 0.05 to 0.3 parts by weight of a hindered amine compound, and when it is an agricultural olefin resin film, it contains 0.05 to 2 parts by weight of a hindered amine compound for agricultural use. Sunscreen.

In this case, the agricultural olefin resin film is a multilayer structure, and at least the agricultural sunscreen containing the hindered amine compound in the outer layer of the sunscreen is preferably applied.

More specifically, at least one of the inorganic substances is selected from the group consisting of calcium carbonate and titanium oxide. Titanium white, talc, clay, cerium oxide, mica, barium sulfate, etc., and inorganic materials are preferred as agricultural sunscreens for calcium carbonate or titanium oxide.

Specifically, the resin latex resin is classified into a hydrogen resin emulsion having an acid value of 30 to 300, and an agricultural sunscreen having an average resin particle diameter of 0.01 to 0.5 μm.

Further, in another aspect of the present invention, a coating method for an agricultural sunscreen which forms the above-mentioned agricultural sunscreen agent to form a light-shielding layer which can be removed by an alkaline remover is applied.

The light-shielding coating film formed by the agricultural sunscreen agent of the present invention is not easily lost by rain or the like, and has a light-shielding effect over a long period of time. Further, when the light-shielding coating film is not used, it is not necessary to replace it with a new agricultural resin film, and the alkaline removal liquid can be easily removed.

In particular, in the first aspect of the invention, a resin latex, two inorganic materials having different average particle diameters, and water of an aqueous solvent are used as the light-shielding coating liquid component, and the ratio of the resin component to the inorganic material is set in the solid content ratio. Within a specific range, in particular, the obtained light-shielding coating film is water-resistant by using a certain ratio of inorganic substances having an average particle diameter. Therefore, even if the film of the inorganic substance is not lost, the light-shielding effect is obtained over a long period of time.

Further, in the second aspect of the invention, in particular, an agricultural vinyl chloride resin film coated with an agricultural sunscreen agent, the base layer of the sunscreen agent has an acrylic resin polymerized on the agricultural vinyl chloride resin film to form a hydroxyl group-containing monomer. Features such as the coating layer. By the base layer, the light-shielding agent can be uniformly formed on the film, and the formed light-shielding coating film has excellent durability.

The third aspect of the invention is characterized in that a resin film containing a hindered amine compound is used as an agricultural resin film for coating an opacifier, by using a phase The resin film can be uniformly formed on the film, and the formed light-shielding film has excellent durability.

The best form of implementing the invention

Hereinafter, the present invention will be described in more detail based on various aspects.

The agricultural sunscreen agent of each aspect of the present invention contains an inorganic substance added to ensure the light-shielding property, such as calcium carbonate, titanium oxide, titanium white, talc, clay, cerium oxide, mica or barium sulfate. Among them, calcium carbonate or titanium oxide is particularly preferable. Further, two or more inorganic substance mixtures can be used as needed.

The inorganic substance in the first aspect of the present invention is composed of two kinds of inorganic substances having different average particle diameters.

In particular, the difference in particle diameter is a combination of an inorganic material having an average particle diameter of less than 1 μm and an inorganic material having an average particle diameter of 1 μm or more on the basis of 1 μm. The largest average particle diameter is 100 μm. The inorganic substance may be the same inorganic substance or a different inorganic substance having an average particle diameter difference.

When the inorganic material having an average particle diameter of less than 1 μm and the resin latex as a binder are applied together to the agricultural greenhouse film, a strong inorganic film is formed by dispersing the fine particles in the resin latex to enhance the water resistance. However, it is not easy to remove when not in use.

On the other hand, when an inorganic substance having an average particle diameter of 1 μm or more and a resin latex as a binder are applied together to an agricultural greenhouse film, water resistance is lacking.

Therefore, in the present invention, water resistance and removability can be coordinated by mixing the above two. As a result of the test, the inventors have determined that the ratio of the inorganic substance having an average particle diameter of less than 1 μm to the inorganic substance having an average particle diameter of 1 μm or more is in the range of 1:0.5 to 2 in order to ensure the water resistance and the removability of the agricultural light-shielding coating liquid. Just fine.

That is, when the blend ratio of the inorganic material having an average particle diameter of less than 1 μm and the inorganic material having an average particle diameter of 1 μm or more is less than 0.5, the water resistance of the agricultural light-shielding coating liquid is not good, and when it exceeds 2, the water resistance is sufficient, but removal is performed. Poor sex.

These inorganic substances having different average particle diameters, for example, various inorganic substances described above, and preferably calcium carbonate and titanium oxide are used.

On the other hand, in the second and third aspects of the present invention, the particle diameter of the inorganic substance is not particularly limited, and those having an average particle diameter of less than 1 μm to an average particle diameter of 100 μm can be widely used. Further, when an inorganic material having an average particle diameter of less than 1 μm is applied to an agricultural greenhouse film together with a resin latex as a binder, a strong inorganic film is formed by dispersing fine particles in a resin emulsion to enhance water resistance. The second aspect and the third aspect of the present invention do not have the above disadvantages when the removability when not in use is poor.

Further, when an inorganic material having an average particle diameter of 1 μm or more and a resin latex as a binder are applied to an agricultural greenhouse film together, there is a disadvantage that water resistance is poor, and the second aspect and the third aspect of the present invention have no such disadvantages. Of course, the first aspect of the inorganic substance can also be used in the second aspect and the third aspect.

In the agricultural sunscreen agent provided by the present invention, the content of the relevant inorganic substance may be an amount which exhibits a desired light-shielding effect of the light-shielding agent. When the dispersibility in the resin latex of the binder is considered, when the ratio of the resin component to the inorganic component is expressed by the solid content ratio, it is preferably from 1:0.3 to 1:15. That is, when the blend ratio of the inorganic material is less than 0.3, it is difficult to have a desired light-shielding effect, and even if the ratio is more than 15, the blending ratio is more than 15, and there is no better light-shielding effect and water resistance is lowered. When the sunscreen is applied by a spray method, it is less desirable to cause clogging.

The invention provides an agricultural cover for a light-shielding coating liquid for agricultural film In the photo-curing agent, the resin in the light-shielding coating liquid is dried by a light-shielding coating liquid applied to the film, and then a resin which is a resin film which uniformly maintains the binder of the inorganic substance is formed.

An aqueous resin latex having an acid value of 30 to 300 can be used as the above resin. Such a water-dispersible resin such as an acrylic resin, a urethane resin, an ethylene resin, a polyester resin, an epoxy resin, or the like, wherein the water-dispersible acrylic resin having an acid value of 30 to 300 is water-dispersed. Amine carboxylic acid based resins are preferred.

This acid value is related to the average number of free carboxylic acid groups per chain in the polymer-based binder, and the higher the acid value, the less water-resistant and soluble in water. Further, the smaller the acid value, the less soluble in water. In the present invention, the resin component in the aqueous resin emulsion is one having an acid value of 30 to 300, and has a considerable degree of water resistance, and can satisfy the holding period of the desired light-shielding coating film.

When the acid value is less than 30, the formed coating film has no problem of water resistance, but from the viewpoint of the removability, it is difficult to remove the coating film by the removal liquid, which is not preferable. Further, when the acid value exceeds 300, the water resistance of the resin film is lowered, and the performance of the sunscreen which is applied after a long period of time is lowered, which is not preferable.

Further, the resin having a resin latex preferably has an average particle diameter of 0.01 to 0.5 μm. When the average particle diameter is less than 0.01 μm, the function of the latex cannot be exhibited, and when it exceeds 0.5 μm, the resin applied to the film is less likely to be lost.

The content of the resin latex in the light-shielding coating liquid provided by the present invention is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the resin solid content, in consideration of the blending ratio of the inorganic substance to be blended. If it is less than 0.1 part by weight, the coating film on the film may not be sufficiently formed, and if it exceeds 10 parts by weight, in addition to lowering the coating workability, the drying time after coating is also time consuming, and conversely, the coating film is held. There is no relative increase in continuity and there is no economic benefit.

In the light-shielding coating liquid of the present invention, in addition to the above-mentioned inorganic substances, particularly calcium carbonate or titanium oxide, a hardener, a preservative, a thickener, a viscosity reducing agent, a dispersing agent, a surfactant, and an antioxidant may be further added as needed. , UV absorbers, light stabilizers, alcohols, etc.

Conventionally, an agricultural sunscreen agent of the light-shielding coating liquid of the present invention is applied to any of the films which are agricultural films. The material of such a film is, for example, a polyvinyl chloride film, a polyester film, an acrylic film, a polyethylene film, a polypropylene film, a polyurethane film, a glass film, a vinyl acetate film, or the like.

In particular, a resin constituting a vinyl chloride resin film for agricultural use, for example, a polyvinyl chloride polymer, a vinyl chloride-vinyl acetate copolymer, a vinyl chloride-ethylene copolymer, a vinyl chloride-propylene copolymer, a vinyl chloride-isopropene copolymer, Vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride terpolymer, vinyl chloride-alkyl, cycloalkyl or alkyl maleimide copolymer, vinyl chloride-styrene-propylene Nitrile copolymer, vinyl chloride-butadiene copolymer, vinyl chloride-isoprene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-acrylate copolymer, vinyl chloride-Malay A vinyl chloride copolymer such as an acid ester copolymer, a vinyl chloride-methacrylate copolymer, a vinyl chloride-acrylonitrile copolymer, or a vinyl chloride-aminecarboxylic acid copolymer.

Further, the vinyl chloride resin to be used may be a blend with the following polymers. Polymers of this type, such as polyethylene, polypropylene, polybutene, poly-3-methylbutene, etc., alpha-olefin polymers, ethylene-vinyl acetate copolymers, ethylene-propylene copolymers, and the like, and copolymers thereof , polystyrene, acrylic, styrene and other monomers (eg maleic anhydride, butadiene, acrylonitrile, etc.) Copolymer, acrylonitrile-butadiene-styrene copolymer, methacrylate-butadiene-styrene copolymer, polyaminecarboxylic acid, and the like.

Various additives such as a plasticizer, a stabilizer, a slip agent, an anti-adhesive agent, a UV absorber, an antioxidant, and an inorganic filler may be added to these vinyl chloride resin compositions as needed. These additives may be various additives which have been used as an additive of a vinyl chloride resin film since ancient times, and the blending amount thereof varies depending on the type thereof, and is about 0.001 to 10 parts by weight based on 100 parts by weight of the vinyl chloride resin.

In order to impart flexibility to the vinyl chloride resin, a plasticizer such as di-n-octyl phthalate or di-2-ethyl is added to the vinyl chloride resin used in the present invention. Hexyl phthalate, diisodecyl phthalate, dibutyl phthalate, butyl benzyl phthalate, dilauryl phthalate, a phthalate plasticizer such as dimercapto phthalate, twenty-one phthalate or ditributyl butyl phthalate, in which di-n-octyl neighbor Phthalate is preferred (DOP). In addition, other plasticizers such as trimethylbenzene phosphate (TXP), tricresol phosphate, tris(isopropylphenyl) phosphate, tributyl phosphate, triethyl phosphate, triphenyl may also be mixed. Phosphate plasticizers such as phosphatidyl ester and triethyl phenyl phosphate.

The vinyl chloride-based resin composition for use in the agricultural vinyl chloride-based resin film may be formed into a film by a conventional calendering method, extrusion method, or blow molding method.

On the other hand, the resin constituting the agricultural olefin resin film of the present invention, for example, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polymerization polymerization using an aromatic cycloolefin metal derivative catalyst B Polyethylene such as olefin, random polypropylene, block polymerized polypropylene, isotactic polypropylene, syndiotactic polypropylene, etc.; ethylene-vinyl acetate, ethylene-acrylic acid, ethylene-acrylate, ethylene-methacrylic acid, An olefin resin such as an ethylene copolymer such as ethylene-methacrylate may be used alone or in a mixture thereof.

Among them, for example, an ethylene-α-ene copolymer (generally known as an aromatic cycloolefin metal derivative polyethylene) and high-pressure radicals are obtained by copolymerizing ethylene and an α-ene having 4 to 10 carbon atoms using an aromatic cycloolefin metal derivative catalyst. Ethylene low-density polyethylene (HP-LDPE), ethylene-vinyl acetate copolymer (EVA) with a vinyl acetate content of 1 to 25% by weight, and ethylene and carbon number 4 using Ziegler catalyst, chromium oxide catalyst, and molybdenum oxide catalyst It is preferred to copolymerize ~20 of the α-olefin to obtain an ethylene-α-ene copolymer (LLDPE).

The olefin resin film of the present invention may have a single layer structure or a multilayer structure. In the case of a multilayer structure, at least when the greenhouse is unfolded, the outer layer coated with the opacifier must be blended with a hindered amine compound. Further, a hindered amine compound may be blended in any of the multilayer structures.

In the case of a multilayer structure, the types of the resins constituting each layer may be the same or different, and the resins of the adjacent layers are preferably compatible with each other or have high adhesion. For example, LLDPE in an olefin resin is used as an outer layer, and an intermediate layer (and an inner layer) laminated underneath is a low-density polymer which is compatible with LLDPE and denatured with any one of methacrylic acid, maleic anhydride, and acrylic acid. Ethylene, high-density polyethylene, polypropylene, ethylene-vinyl acetate copolymer (EVA), etc., wherein an ethylene-vinyl acetate copolymer (EVA) having a vinyl acetate content of 1 to 25% by weight is preferred.

Moreover, when it is a multilayer structure of three or more layers, the two outermost layers are the same kind of resin, and when a hindered amine compound is added, no matter which side is the outer side, It is ideal to have the same effect when unfolding.

Further, the olefin resin used in the present invention may contain various additives within a range that does not affect the target performance. For example, an olefin resin film is inferior in friction resistance to a vinyl chloride resin film, and a slip agent such as a guanamine type slip agent can be added. Further, for example, various additives such as various stabilizers, leak preventive agents, anti-sticking agents, ultraviolet absorbers, antioxidants, and inorganic fillers. The blending amount of these additives varies depending on the kind thereof, and the blending amount thereof is about 0.01 to 10 parts by weight based on 100 parts by weight of the olefin resin.

In the second aspect of the invention, when the agricultural sunscreen is applied, at least one surface of the agricultural vinyl chloride resin film coated with the light-shielding agent is coated with an acrylic resin copolymerized with a hydroxyl group-containing monomer to form a coating film. The thickness of the coating film is preferably 0.5 to 5 μm. When the thickness of the coating film is less than 0.5 μm, the durability of the coating layer of the agricultural sunscreen applied to the coating film cannot be improved, and if it exceeds 5 μm, the durability cannot be improved.

When an acrylic resin coating film is provided on a vinyl chloride resin film for agricultural use, it is preferable to form a coating film by a gravure method or the like on the same production line or other engineering. The acrylic resin coating film may be provided after the film is developed in a vinyl greenhouse, etc., but it is difficult to form a uniform coating film and workability is poor.

In order to make the film and the coating film adhere more strongly, a crosslinking agent such as a terminal isoleamide compound may be added to the acrylic resin.

An acrylic resin obtained by copolymerization of a hydroxyl group-containing monomer which forms such a base layer, wherein a hydroxyl group-containing monomer such as methylol acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxyl Hydroxy acrylate such as propyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxypentyl acrylate, 6-hydroxyhexyl acrylate; methylol methacrylate, 2- Hydroxyethyl Methyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxypentyl methacrylate Hydroxymethacrylate such as ester or 6-hydroxyhexyl methacrylate.

In this manner, the agricultural sunscreen agent of the present invention is applied onto the surface on which the acrylic resin coating film is provided by a method such as spraying. Usually, the surface on which the acrylic resin coating film is provided on the film is used as the outer side, and after the development of the ethylene greenhouse or the like, it is necessary to apply the agricultural sunscreen agent on the surface of the film to form a light shielding layer. If it is necessary to have a light-shielding property from the beginning, it can be applied to a film production project or other work before the unfolding, but it is less likely to cause defects in the light-shielding layer during the operation stage at the time of unfolding.

Further, a third aspect of the agricultural film of the agricultural sunscreen of the present invention is applied to which a hindered amine compound is added.

In the vinyl chloride agricultural resin film, the hindered amine compound is preferably added in an amount of 0.05 to 0.3 parts by weight. If the amount is less than 0.05 part by weight, the durability of the light-shielding coating film formed on the film cannot be improved, and if the amount exceeds 0.3 part by weight, the effect is not increased, and waste is caused.

In the olefin agricultural resin film, the hindered amine compound is preferably added in an amount of 0.05 to 2 parts by weight. If the amount is less than 0.05 part by weight, the durability of the light-shielding coating film formed on the film cannot be improved, and if the amount is more than 2 parts by weight, the effect is not increased, and waste is caused.

Such hindered amine compounds such as 2,2,6,6-tetramethyl-4-piperidine stearate, 1,2,2,6,6-pentamethyl-4-piperidine stearate , 2,2,6,6-tetramethyl-4-piperidine benzoate, N-(2,2,6,6-tetramethyl-4-piperidine)tridecyl succinate Amine, 1-[(3,5-di-tris-butyl-4-hydroxyphenyl)propanyloxy -2,2,6,6-tetramethyl-4-piperidine (3,5-tris-butyl-4-hydroxyphenyl)propionate, bis(2,2,6,6- Tetramethyl-4-piperidine) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidine) sebacate, bis(1,2,2,6, 6-pentamethyl-4-piperidinyl-2-butyl-2-(3,5-di-tertiary-butyl-4-hydroxybenzyl)hexamethylenedifluoride, four (2,2 6,6-tetramethyl-4-piperidine)butene tetracarboxylate, bis(2,2,6,6-tetramethyl-4-piperidine)di(tridecyl)butane Tetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidine)di(tridecyl)butanetetracarboxylic acid ester, 3,9-double {1,1 -Dimethyl-2-[tris(2,2,6,6-tetramethyl-4-piperidinyloxy)butylcarbonyloxy]ethyl}-2,4,8,10-tetraoxy Thipid[5,5]undecane, 3,9-bis{1,1-dimethyl-2-[tris(1,2,2,6,6-pentamethyl-4-piperidinyloxy) Carbonyloxy)butylcarbonyloxy]ethyl}-2,4,8,10-tetraoxythiapyrrole[5,5]undecane, 1,5,8,12-tetra[4,6-double [N-(2,2,6,6-tetramethyl-4-piperidine)butylamine]-1,3,5-triazin-2-yl]-1,5,8,12-tetrazine Decane, 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidine/succinic dimethyl condensate, 2-tris-octylamine-4,6- Dichloro-s-trizide/N,N'-bis(2,2,6,6-tetramethyl-4-piperidine) hexamethylene A hindered amine compound such as a bisamine/dibromoethane condensation compound.

In the above-mentioned composition, the agricultural resin film used in the present invention is formed into a film by a known method such as a calendering method, an extrusion method, or a blow molding method which has been conventionally used. Further, the processing conditions such as the temperature at the time of film formation may be the same as the conditions for previously producing the agricultural resin film. Further, the thickness of the film may be about 0.01 to 0.2 mm. When the olefin resin film is a film having a three-layered multilayer structure, the ratio of the thickness of each layer is preferably an outer layer/intermediate layer/inner layer = 1/3/1.

In the present invention, the coating amount of the light-shielding coating liquid which is the light-shielding coating liquid of the present invention is preferably 0.1 to 50 g/m ^{2 in} terms of solid content. If it is less than 0.1 g/m ^{2 , it} does not have sufficient shading effect. Further, when it exceeds 50 g/m ² , it is less desirable that the resin is easily dropped from the agricultural film during the coating operation.

The agricultural film containing the inorganic material containing 30 to 300 acid value and the light-shielding coating liquid containing water as an aqueous solvent are sprayed or coated on the agricultural film to form an inorganic coating film having excellent water resistance, and the light-shielding effect can be easily obtained.

On the other hand, when a light-shielding coating film is not used, it is not necessary to use a large amount of organic solvent, and it can be easily removed with an alkaline removal liquid.

Example

Hereinafter, the present invention will be described in more detail by way of examples and comparative examples, but the invention is not limited thereto.

Embodiments 1 to 8:

The agricultural sunscreen, that is, the light-shielding coating liquid of the present invention, was prepared according to the formulation (parts by weight) of the following Table 1. The obtained light-shielding coating liquid was spray-coated on an agricultural vinyl greenhouse film, and the state of the coating film, the water resistance of the coating film, and the removability of the coating film were evaluated on a predetermined basis. Table 1 shows the results.

%; resin average particle size 1 μm; molecular weight 200,000 or more

*6: The state of the coating film was evaluated according to the following measurement.

After coating the light-shielding coating liquid to form a coating film and drying it, the surface of the coating film was rubbed with a finger, and the peeling state of the coating film was visually determined by the following criteria.

◎: No change at all.

○: Several peels but no effect.

□: Several strips.

△: Most of the peeling.

×: All peeled off.

*7: Evaluation of water resistance The light-shielding coating liquid was sprayed on an agricultural film and dried, and then immersed in water for 12 hours, and then taken out, and the surface of the coating film was rubbed with a finger, and the peeling state of the coating film was visually determined by the following criteria.

◎: No change at all.

○: Several peels but no effect.

□: Several strips.

△: Most of the peeling.

×: All peeled off.

*8: Removability evaluation: After spraying the light-shielding coating liquid on an agricultural film and drying, 100 parts by weight of water, 0.5 part by weight of sodium hydroxide, 10 parts by weight of benzyl alcohol, and 0.2 part by weight of dodecylbenzenesulfonate The removal liquid of the sodium composition was sprayed on the film, and the degree of peeling of the coating film when the water was sprayed after spraying for 5 minutes was visually judged by the following criteria.

◎: completely detached.

○: Several residues but no effect.

□: Several residues.

△: Most of the residue.

×: All do not fall off.

Comparative Examples 1~7:

In the same manner as in the above Example, a light-shielding coating liquid of a comparative example, that is, a light-shielding coating liquid, was obtained in accordance with the formulation (parts by weight) of Table 2 below. The obtained light-shielding coating liquid was spray-coated on an agricultural vinyl greenhouse film, and the state of the coating film, the water resistance of the coating film, and the removability of the coating film were evaluated on a predetermined basis. Table 2 shows the results.

*1~*8 in the table are the same as Table 1.

As is clear from the results of the above Examples 1 to 8 and Comparative Examples 1 to 7, the light-shielding coating liquid of the present invention is a resin emulsion which is a binder, and is blended with two kinds of inorganic substances having different particle diameters. The agricultural film has good light-shielding properties, and the spray-formed coating film is in a good state, and is excellent in water resistance and removability.

Examples 9 to 13 / Comparative Examples 8 to 10

The blended undercoat layer (parts by weight) of Table 3 was applied to Achilles nutrient (vinyl chloride resin film) by a gravure method, and dried at 90 ° C for 30 seconds to prepare a base layer film.

On the other hand, the sunscreen agent of the present invention was obtained in accordance with the formulation (parts by weight) of Table 3 below. The obtained sunscreen was applied to the underlayer film, and the state of the coating film, the water resistance and the removability of the coating film were evaluated on a predetermined basis. Table 3 shows the results.

Resin latex

*3: Acid value of 200; molecular weight of more than 200,000; solid content of 32% of acrylic resin latex

*4: Acid value of 400; molecular weight of more than 200,000; solid content of 30% of acrylic resin latex

*5: The durability of the shading film was evaluated according to the following measurement.

Each of the sunscreens was uniformly sprayed on the above-mentioned film developed outside using a sprayer to form a 30% shading. After spraying, it was placed outside the house for about one month, and the peeling state of the light-shielding coating film was visually determined by the following criteria.

◎: 80% or more of the coating film remained.

○: 60% to less than 80% of the coating film remained.

□: 40%~ less than 60% of the coating film remains.

△: 10% to less than 40% of the coating film remained.

×: Only the coating film having less than 10% remains.

*6: Evaluation of the removability of the light-shielding coating film, after spraying the sunscreen agent on the agricultural film and drying it, 100 parts by weight of water and 0.5 part by weight of sodium hydroxide for the coating film placed one month after the outside of the house A removal liquid composed of 10 parts by weight of benzyl alcohol and 0.2 part by weight of sodium dodecylbenzenesulfonate was sprayed on the film, and the degree of peeling of the coating film when sprayed for 5 minutes and then sprayed with water was visually determined by the following criteria.

◎: 80% or more of the coating film has fallen off.

○: 60% to less than 80% of the coating film has fallen off.

□: 40%~ less than 60% of the coating film has fallen off.

△: 10% to less than 40% of the coating film has fallen off.

×: Only less than 10% of the coating film has fallen off.

*7: Even if the shading solution is sprayed with a sprayer, the shading liquid will fall off by itself and cannot be evaluated.

From the results of the above-described Examples 9 to 13 and Comparative Examples 8 to 10, it is clear that the opacifier of the present invention is obtained by dispersing or coating an acrylic resin emulsion spray copolymerized with a hydroxyl group-containing monomer on a vinyl chloride having a base layer. On the agricultural resin, an inorganic coating film having excellent durability is formed, and the light-shielding effect is maintained over a long period of time. (Examples 9 to 13)

On the other hand, when the vinyl chloride-based agricultural resin film does not have a base layer formed of an acrylic resin obtained by copolymerization of a hydroxyl group-containing monomer (Comparative Examples 8 and 9), or when the base layer is not provided at all (Comparative Example 10), The light-shielding coating film cannot be formed on the film, and the durability and the removability of the light-shielding coating film are not preferable.

Examples 14 to 19:

A vinyl chloride agricultural resin film (thickness: 0.1 mm) was prepared by a rolling method according to the formulation (parts by weight) of the following Table 4.

Using the obtained vinyl chloride film, it was developed in an agricultural ethylene greenhouse, and the agricultural sunscreen agent of the present invention in the table was spray-coated thereon, and the state of the coating film, the sustainability of the coating film, and the removal were evaluated on a certain basis. The results are shown in Table 4.

*2: Hindered amine compound: LA-63 (made by Asahi Kasei Kogyo Co., Ltd.)

*3: Acid value of 60; molecular weight of more than 200,000; solid content of 47% of acrylic resin latex

*4: Acid value of 200; molecular weight of more than 200,000; solid content of 32% of acrylic resin latex

*5: Acid value of 400; molecular weight of more than 200,000; solid content of 30% of acrylic resin latex

*6: The evaluation of the sustainability of the light-shielding film was carried out in the same manner as in Examples 9 to 13.

*7: Evaluation of the removability of the light-shielding coating film, after spraying the sunscreen on the agricultural film and drying, 100 parts by weight of the aqueous solution of pH 11 and 5 parts by weight for the coating film placed one month after the outside of the house The removal liquid obtained by mixing benzyl alcohol and 0.2 part by weight of diethanolamine was sprayed on the film, and the degree of peeling of the coating film when washed with water for 5 minutes was visually determined by the following criteria.

◎: 80% or more of the coating film has fallen off.

○: 60% to less than 80% of the coating film has fallen off.

□: 40%~ less than 60% of the coating film has fallen off.

△: 10% to less than 40% of the coating film has fallen off.

×: Only less than 10% of the coating film has fallen off.

Comparative Example 11~15

A vinyl chloride agricultural resin film (thickness: 0.1 mm) was prepared by a rolling method according to the formulation (parts by weight) of the following Table 5.

Using the obtained vinyl chloride film, it is developed in an agricultural ethylene greenhouse, and the agricultural sunscreen agent of the present invention in the table is spray-coated thereon to have a certain basis. The state of the coating film, the sustainability of the coating film, and the removability were evaluated, and the results are shown in Table 5.

Again, the annotations in Table 5 are synonymous with the annotations in Table 4.

As is clear from the results of the above Examples 14 to 19 and Comparative Examples 11 to 15, it is understood that the light-shielding coating film can be excellent by applying the light-shielding agent of the present invention to a vinyl chloride-based agricultural resin film containing a hindered amine compound. Persistent. On the other hand, in the vinyl chloride-based agricultural resin film of Comparative Example 12 which does not contain a binder, the light-shielding agent of the present invention cannot form a light-shielding coating film on the surface of the agricultural vinyl chloride resin film. Further, the light-shielding coating film of the present invention has excellent removability when it is not required to be used.

Examples 20-29:

An olefin resin film having a three-layer structure of outer layer/intermediate layer/inner layer was prepared by a blow molding method according to the formulation (parts by weight) of the following Table 6 (thickness: 0.1 mm; layer ratio: outer layer/intermediate layer/inner layer = 1/3/1).

Using the obtained ethylenic resin film, it was developed in an agricultural greenhouse, and the sunscreen agent of the present invention in the above table was spray-coated thereon, and the state of the coating film, the sustainability of the coating film, and the removability were evaluated on a predetermined basis. The results are shown in Table 6.

*1: Hindered amine compound: LA-63 (made by Asahi Kasei Kogyo Co., Ltd.)

*2: Acid value of 60; molecular weight of more than 200,000; solid content of 47% of acrylic resin latex

*3: Acid value of 200; molecular weight of more than 200,000; solid content of 32% of acrylic resin latex

*4: Acid value of 400; molecular weight of more than 200,000; solid content of 30% of acrylic resin latex

*5: The evaluation of the sustainability of the light-shielding coating film was carried out in the same manner as in Examples 9 to 13.

*6: Evaluation of the removability of the light-shielding coating film was carried out in the same manner as in Examples 14 to 19.

Comparative Examples 16~18:

An olefin resin film having a three-layer structure of outer layer/intermediate layer/inner layer was prepared by a blow molding method according to the formulation (parts by weight) of Table 7 below (thickness: 0.1 mm; layer ratio: outer layer/intermediate layer/inner layer = 1/3/1).

Using the obtained olefin resin film, it was developed in an agricultural greenhouse, and the sunscreen agent of the present invention in the above table was spray-coated thereon, and the state of the coating film, the sustainability of the coating film, and the removability were evaluated on a predetermined basis. The results are shown in Table 7.

Again, the annotations in Table 7 are synonymous with the annotations in Table 6.

*7: The light-shielding coating film was peeled off due to rain after one month, so it was impossible to determine.

As is clear from the results of the above examples and comparative examples, the agricultural light-shielding agent of the present invention can be applied to an agricultural olefin resin film containing a hindered amine compound, whereby the light-shielding coating film can have good durability. On the other hand, in the agricultural olefin resin film of the comparative example which does not contain a hindered amine compound, the light shielding agent of this invention cannot form the light-shielding coating film on the surface of the agricultural olefin resin film. Further, the light-shielding coating film of the present invention has excellent removability when it is not required to be used.

Even if it is an agricultural olefin resin film containing a hindered amine compound, the agricultural sunscreen agent of the present invention, that is, the binder is a hydrogen resin binder, and when the resin is classified into a resin latex having an acid value of more than 300, the light-shielding coating film cannot be ensured. Persistent.

Industrial application possibilities

As described above, the agricultural sunscreen agent for the agricultural film used in the greenhouse cultivation or the tunnel shed cultivation of the present invention does not lose the inorganic film even when it is rained, and can be formed to have excellent durability after a long period of time. Shading film. Moreover, when the light-shielding coating film is not used, it is not necessary to use a large amount of organic solvent, and the alkali removing liquid can be easily removed, and it is not necessary to discard or replace the covering material such as a greenhouse or a tunnel shed, and the agricultural producer has the advantage of saving a large amount of money.

Claims (8)

An agricultural sunscreen agent characterized by a light-shielding coating liquid composed of an inorganic material, a resin latex, and an aqueous solvent; the ratio of the resin component to the inorganic component is 1:0.3 to 1:15, and the inorganic component is simultaneously Two inorganic materials such as an inorganic material having an average particle diameter of less than 1 μm and an inorganic material having an average particle diameter of 1 μm or more are used, and an inorganic material having an average particle diameter of less than 1 μm: an inorganic material having an average particle diameter of 1 μm or more is in a range of 1:0.5 to 2, and A light-shielding coating film is formed on the agricultural film. The agricultural sunscreen agent according to claim 1, wherein the inorganic substance is at least one white pigment selected from the group consisting of calcium carbonate, titanium oxide, titanium white, talc, clay, cerium oxide, mica, and barium sulfate. For example, the agricultural sunscreen agent according to the first aspect of the patent application, wherein the resin latex resin is divided into a hydrogen resin latex having an acid value of 30 to 300, and the average particle diameter of the resin is 0.01 to 0.5 μm. A method for coating an agricultural sunscreen, characterized in that at least one side of a vinyl chloride-based agricultural film is coated with an acrylic resin copolymerized with a hydroxyl group-containing monomer to form a coating film, and then an inorganic white pigment and a resin latex are used. The agricultural sunscreen agent is applied to the surface of the coating film to form a light shielding layer which can be removed by an alkaline removing agent. A method for coating an agricultural sunscreen, characterized in that an agricultural sunscreen comprising an inorganic white pigment and a resin latex is applied to a vinyl chloride agricultural film containing 0.05 to 0.3 parts by weight of a hindered amine compound to form an alkaline Remover removes the shading layer. A coating method for agricultural sunscreen, characterized by white of inorganic substances An agricultural sunscreen agent composed of a color pigment and a resin latex is applied to an agricultural olefin resin film containing 0.05 to 2 parts by weight of a hindered amine compound to form a light-shielding layer which can be removed by an alkaline remover. The method for coating an agricultural sunscreen according to any one of claims 4 to 6, wherein at least one of the inorganic substances is selected from the group consisting of calcium carbonate, titanium oxide, titanium white, talc, clay, cerium oxide, mica, sulfuric acid. White pigment. The method for coating an agricultural sunscreen according to any one of claims 4 to 6, wherein the resin latex resin is classified into an aqueous resin latex having an acid value of 30 to 300, and the resin has an average particle diameter of 0.01 to 0.5 μm.