JPH0460825B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention is an agricultural soft vinyl chloride system that is easy to spread, has excellent dustproof and antifogging properties after being spread, and has excellent durability and maintains these excellent properties for a long period of time. This invention relates to resin films. "Conventional technology" In recent years, farmers cultivating useful plants have widely adopted methods of promoting or suppressing cultivation of useful plants in greenhouses or tunnels in order to improve profitability. Ta. Polyethylene film, ethylene-vinyl acetate copolymer film, polyester film, polycarbonate film, vinyl chloride resin film, glass, etc. are used as covering materials for the greenhouse or tunnel. Among them, soft vinyl chloride resin film is widely used because it has the best overall light transmittance, heat retention, mechanical strength, durability, workability, economic efficiency, etc. compared to other synthetic resin films. It is used. The properties required for materials used as covering materials for greenhouses or tunnels are that the outer surface remains clean for a long period of time, has excellent dust resistance, maintains good light transmittance, and promotes the growth of cultivated crops. . It has excellent anti-fog properties, allowing condensed water adhering to the inner surface of the coating material to flow down along the inner surface of the film without falling onto the cultivated crops, and maintains the inside of the greenhouse or tunnel at an appropriate level of humidity, preventing disease. To suppress the occurrence. etc. On the other hand, based on conventional experience, soft vinyl chloride resin films used for agriculture are affected by the region and place where they are used, but after two years of use, The dust resistance of the outer surface deteriorates significantly, making it unusable.
Furthermore, after two summers (futanatsu, the second summer) have passed since the start of film expansion, the antifogging properties of the inner surface deteriorate, making subsequent use difficult. As a method to improve dust resistance,
Publication No. 28740, Japanese Patent Publication No. 1983-31195, Japanese Patent Publication No. 1983
As described in Japanese Patent Publication No. 99237, Japanese Patent Publication No. 56-99665, etc., there is a method of forming a coating of a specific acrylic resin on one or both sides of a vinyl chloride resin film as a substrate. In addition, JP-A-51-
Publication No. 70282 describes a method of forming a film of an acrylic resin of a specific composition containing an ultraviolet absorber on the surface of a film of a substrate. but,
The films formed on the base film in these methods are mainly made of thermoplastic resin, so the additives contained in the base film can pass through the film and reach the surface, especially during the summer when the outside temperature is high. to migrate, to be washed away and to disappear,
It is difficult to completely suppress it, and there are still problems when the film is stretched and used outdoors for a long period of time. Therefore, in order to further improve the above-mentioned drawbacks, Japanese Patent Application Laid-Open No. 56-53070, Japanese Patent Application Laid-Open No. 57-70031,
As described in JP-A-57-163568, etc., a method has been proposed in which at least one surface of a vinyl chloride resin film is coated with a cationic polymerizable energy ray curable resin composition. However, the epoxy resin composition that is preferably used as a cationically polymerized energy beam-curable resin composition according to this method is susceptible to weather resistance deterioration in the film formed from it, and is insufficient to achieve the intended purpose. The drawback was that I couldn't get it. In addition, in order to improve antifogging properties, a method is usually adopted in which so-called antifogging agents, such as fatty acid esters of glycerin and fatty acid esters of sorbitan, are kneaded into the base resin. The film bleeds quickly, and the antifogging effect wears off after one year has passed after the film is spread on the greenhouse, so studies are being conducted to improve the antifogging durability. "Problems to be Solved by the Invention" Under such circumstances, the inventors of the present invention aimed to improve the ease of spreading work and prevent discoloration, embrittlement, deterioration of anti-fogging properties, etc. caused by spreading outdoors. With the aim of providing an agricultural vinyl chloride resin film with significantly improved durability and improved durability, we found that a silane compound and an acrylic resin film were added to one side of the soft vinyl chloride resin film. They have discovered that a good improvement effect can be obtained by applying an antifogging agent composition containing colloidal silica or alumina sol as a main component to the other side of a dustproof coating composition consisting of a resin, and have completed the present invention. It has arrived. "Means for Solving the Problems" Therefore, the gist of the present invention is to provide a silane compound or a hydrolyzate thereof having a hydrolyzable group directly bonded to a silicon atom on one side of a soft vinyl chloride resin film. A coating derived from a coating composition containing acrylic resin and an acrylic resin is formed, and a coating derived from an antifogging agent composition containing colloidal silica and/or alumina sol and a binder as main components is formed on the other side of the film. A soft vinyl chloride resin film for agricultural use is characterized by: The present invention will be explained in detail below. In the present invention, the vinyl chloride resin includes not only polyvinyl chloride but also copolymers whose main component is vinyl chloride. Examples of monomer compounds copolymerizable with vinyl chloride include vinylidene chloride, ethylene, propylene, acrylonitrile, maleic acid, itaconic acid, acrylic acid, methacrylic acid, and vinyl acetate. These vinyl chloride resins may be produced by any of conventionally known production methods such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization. In order to impart excellent flexibility and mechanical strength to the agricultural soft vinyl chloride resin film according to the present invention, usually 20 to 60 parts by weight are added to 100 parts by weight of the base resin.
Add approximately 1 part by weight of plasticizer. Examples of the plasticizer include di-n-octyl phthalate, di-2-ethylhexyl phthalate,
Phthalic acid derivatives such as dibenzyl phthalate, diisodecyl phthalate, didodecyl phthalate, and diundecyl phthalate; Isophthalic acid derivatives such as diisooctyl phthalate; Adipic acid derivatives such as di-n-butyl adipate and dioctyl adipate; di-n-butyl maleate maleic acid derivatives such as; citric acid derivatives such as tri-n-butyl citrate; itaconic acid derivatives such as monobutyl itaconate; oleic acid derivatives such as butyl oleate; ricinoleic acid derivatives such as glycerin monosinolate; Examples include cresyl phosphate, epoxidized soybean oil, and epoxy resin plasticizers. Further, in order to impart flexibility to the resin film, the plasticizer is not limited to the above-mentioned ones, and for example, thermoplastic polyurethane resin, polyvinyl acetate, etc. can also be used. The agricultural soft vinyl chloride resin film of the present invention preferably contains an ultraviolet absorber or a light stabilizer. As the ultraviolet absorber, various types such as benzophenone type and benzotriazole type can be used, and as the light stabilizer, a hindered amine type compound represented by the following general formula [] is suitable. general formula (In the formula, R represents a mono- to tetraalcyl group derived from a mono- to tetravalent carboxylic acid, R ₁ to _{R 4} represent an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 1 to 4, respectively.) Therefore, the blending ratio of the ultraviolet absorber (A) and the light stabilizer (B) to the vinyl chloride resin is such that the total amount of (A) and (B) is 0.02 to 8 parts by weight per 100 parts by weight of the resin. It is preferably in the range of 0.1 to 3 parts by weight. If the blending amount of (A) and (B) is more than 8 parts by weight, there is a risk that they will spray out through the dust-proof coating and anti-fog coating described below. In addition, in order to maintain the durability of the agricultural film, the blending ratio of (A) and (B) should be in the range of (A)/(B) from 15/1 to 1/15, especially 8/1.
It is preferably in the range of 1/8 to 1/8. Of course, the agricultural soft vinyl chloride resin film of the present invention includes:
Other additives for the resin, such as antioxidants, heat stabilizers, antifogging agents, lubricants, pigments, dyes, etc., can be blended and included as necessary. The soft vinyl chloride resin film (hereinafter referred to as the base film), which is the base of the agricultural film of the present invention, is prepared by adding a resin composition, for example, a vinyl chloride resin and necessary resin additives, using a ribbon blender, Banbury, etc. After homogenizing with a mixer, super mixer, or other compounding machine or kneading machine, a normal film manufacturing method such as calendar molding, extrusion molding, inflation film molding, etc. is used to form a 0.03 to 0.3 mm film. Preferably 0.075-0.25
Molded to a thickness of mm. The coating composition that forms a dust-proof film on one side of the base film is mainly composed of a silane compound having a hydrolyzable group directly bonded to a silicon atom or its hydrolyzate and an acrylic resin, and is applied to the base film. After that, it is necessary to easily form a film. Examples of the above-mentioned silane compounds include aminomethyltriethoxysilane, N-β-aminoethylaminomethyltrimethoxysilane, γ-aminopropyltrimethoxysilane, N-(trimethoxysilylpropyl)-ethylenediamine, N-(dimethoxymethyl silylpropyl)-ethylenediamine; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β
- Epoxyalkylalkoxysilanes such as (3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane; γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane Mercaptoalkylalkoxysilanes such as; tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, trimethoxyneopentoxysilane, dimethoxydineopentoxysilane; methyltrimethoxysilane, methyltriethoxysilane, ethyl trimethoxysilane; Alkyltrialkoxysilanes such as methoxysilane and ethyltriethoxysilane; dimethyldimethoxysilane,
Dialkyldialkoxysilanes such as dimethyldiethoxysilane; halogenated alkylalkoxysilanes such as γ-chloropropyltrimethoxysilane and 3,3,3-trichloropropyltrimethoxysilane; alkyls such as methyltriacetoxysilane and dimethyldiacetoxysilane Acyloxysilane; hydrosilane compounds such as trimethoxysilane and triethoxysilane; vinyltrimethoxysilane, vinylethoxysilane, vinyltris (β-
Unsaturated groups such as methoxyethoxy)silane, allyltriethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, γ-(meth)acryloxypropylmethyldimethoxysilane, etc. Examples include monomers or polymers of silane compounds. In the present invention, a hydrolyzate thereof can further be used. The hydrolyzate is obtained, for example, by adding water to a silane compound having a hydrolyzable group in the presence of an acid or alkali catalyst in a combined alcohol system, and is a silane compound having a hydrolyzable group. When more than an equivalent amount of water is added, a completely hydrolyzed alcoholic silica gel or silica sol or siloxane composite is obtained; when less than an equivalent amount of water is added, a partially hydrolyzed product corresponding to the ratio is obtained. is prepared. Further, this partially hydrolyzed product may contain a portion of completely hydrolyzed silica sol. Among these silane compounds having a hydrolyzable group directly bonded to a silicon atom, tetraalkoxysilane monomers or polymers or hydrolysates thereof are particularly preferred. Furthermore, two or more of the above silane compounds may be used in combination. The acrylic resin that is one component of the coating composition is
Alkyl esters of acrylic acid or methacrylic acid (hereinafter referred to as (meth)acrylic acid alkyl esters) monomer alone or a mixture of this and an alkenylbenzene monomer, and copolymerizable α, β - an ethylenically unsaturated monomer under conventional polymerization conditions. Examples of (meth)acrylic acid alkyl esters include acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid n-propyl ester, acrylic acid isopropyl ester, acrylic acid n-butyl ester, acrylic acid 2-
Ethylhexyl ester, decyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, methacrylic acid-2
-Ethylhexyl ester, decyl methacrylate, etc., and generally, an acrylic acid alkyl ester or a methacrylic acid alkyl ester in which the alkyl group has 1 to 20 carbon atoms is used. Examples of alkenylbenzenes to be mixed with (meth)acrylic esters include styrene,
Examples include α-methylstyrene and vinyltoluene. When using a monomer mixture of alkenylbenzenes and (meth)acrylic acid alkyl esters, usually (meth) 10% by weight of acrylic acid alkyl esters
It is better to set it to the above. Other copolymerizable α,β-ethylenically unsaturated monomers used to obtain the acrylic resin include, for example, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid,
α, β-ethylenically unsaturated carboxylic acids such as itaconic acid; α, β-ethylenically unsaturated sulfonic acids such as ethylene sulfonic acid; 2-acrylamido-2-methylpropanoic acid; α, β-ethylenically unsaturated Phosphonic acids; acrylonitriles; acrylamides; hydroxyl group-containing vinyl monomers such as hydroxyalkyl esters of acrylic acid or methacrylic acid; amino esters of acrylic acid or methacrylic acid; glycidyl esters of acrylic acid or methacrylic acid; acrylic acid Or methacrylates, etc. These monomers may be used alone or in combination of two or more. Acrylic resin is produced by combining two or more of these monomers in predetermined amounts into a polymerization can together with organic solvents such as alcohols, aromatic hydrocarbons, acetic esters, ketones, and tetrahydrofuran. It is produced by adding a polymerization initiator such as butyronitrile or benzoyl peroxide and, if necessary, a molecular weight regulator such as mercaptan, followed by heating and polymerization while stirring. The blending ratio of the silane compound to the acrylic resin in the coating composition is 5 to 90 for the former and 95 for the latter in terms of solid weight ratio.
The ratio of ~10 (the total amount of both is 100) is good;
Particularly preferred is 10-80 to 90-20. Within this range, a synergistic effect between the silane compound and the acrylic resin is exhibited. If the proportion of the former is higher than this, the formed film will tend to be sticky and dusty, and the durability will not be sufficiently improved. On the other hand, if the blending ratio of the former is less than this, not only a sufficient dust-proofing effect cannot be exhibited, but also the effect on the weather resistance of the formed film is not sufficient, which is not preferable. In addition to the above-mentioned essential ingredients, the coating composition also contains a crosslinking compound, a small amount of an acid or alkaline antifoaming agent, a surfactant, a lubricant, an antistatic agent, an antioxidant, an ultraviolet absorber, a film forming aid, and a thickener. Various additives such as pigments, pigment dispersants, fungicides, algaecides, and inorganic fillers can be mixed. The crosslinking compound is a compound that can cause a crosslinking reaction with a hydrolyzable group such as a silanol group or an alkoxy group or an acrylic resin in a silane compound, or can promote the crosslinking reaction and make the film tough, such as a phenol resin. Examples include amino resins, amine compounds, aziridine compounds, epoxy compounds, isocyanate compounds, and isocyanate compounds and amine compounds are particularly preferred. The coating composition is usually used by being dispersed or dissolved in an organic solvent, and the same organic solvent as used in producing the acrylic resin can be used. The amount of coating formed by the coating composition on the base film after drying and solidification is 0.1
It is preferable to set it as the range of g/m ^<2> -10g/m ^<2> .
If it is less than 0.1 g/m ² , the effect of preventing the plasticizer from migrating to the surface of the soft vinyl chloride resin film is insufficient. Moreover, if it is 10 g/m ² or more, the amount of coating is too large, which may be economically disadvantageous, and the mechanical strength of the film itself may decrease. Therefore, a range of 0.5 g/m ² to 5 g/m ² is usually most preferred. The antifogging agent composition for forming an antifogging film on the other surface of the base film has silica and/or alumina sol as a main component, and a silica or alumina binder component is mixed therein. The colloidal silica and/or alumina sol preferably has an average particle diameter of 5 to 100 mμ.
If the average particle diameter exceeds 100 mμ, the coating film becomes white and tends to devitrify, and if it is less than 5 mμ, the antifogging composition lacks stability, which is not preferred. these are,
Each may be used alone or both may be used in combination. Further, when used alone or in combination, two or more types having different average particle diameters may be used in combination. When combining the two, the weight ratio of colloidal silica/alumina sol is
The ratio is preferably 95-5/5-95 (total 100). The alumina sol may be a commercially available product itself, or an aqueous sol obtained by dispersing commonly available alumina powder in water. When alumina sol is dispersed in water at a high concentration, it exhibits so-called thixotropy, meaning that the viscosity of the dispersion increases rapidly, making it difficult to obtain a homogeneous dispersion. However, a medium shear internal stirrer such as a colloid mill is used. A homogeneous dispersion can be obtained. Furthermore, when colloidal silica is mixed into this dispersion, the viscosity of the dispersion can be lowered. On the other hand, colloidal silica has particle surfaces that are negatively charged in most cases, but when used in combination with alumina sol, it is not preferable to use negatively charged colloidal silica. This is because when colloidal silica and alumina sol are mixed, the mixed dispersion rapidly aggregates and gels, resulting in poor dispersion. Therefore, the colloidal silica preferably has a positively charged particle surface. As the binder component to be blended into the antifogging agent composition, known and publicly used surfactants such as anionic surfactants, cationic surfactants, nonionic surfactants, and thermoplastic resins can be used. used. The type of surfactant used must be changed depending on colloidal silica or alumina sol. For example, in general, combinations of negatively charged silica sol and cationic surfactant, and positively charged alumina sol and anionic surfactant should be avoided. These combinations tend to cause gelation of the sol and agglomeration/separation of the antifogging agent composition, making application difficult. Thermoplastic resins used as binder components include acrylic resins, vinyl chloride-vinyl acetate resins, polyethylene resins, vinyl chloride resins, vinylidene chloride resins, polyurethane resins, polycarbonate resins, styrene resins, and acetic acid. Examples include vinyl resins and unsaturated polyester resins, with acrylic resins being particularly preferred. The amount of colloidal silica and/or alumina sol that is the main component of the antifogging agent composition is preferably in the range of 0.5 to 40 times the weight of the binder component in terms of solid content weight ratio. When it exceeds 40 times, not only does the antifogging effect not improve in proportion to the amount blended, but also a phenomenon occurs in which the coating film formed after application becomes cloudy and the light transmittance decreases. Furthermore, the coating film tends to become rough and brittle. On the other hand, when it is less than 0.5, it becomes difficult to exhibit sufficient anti-fog effect. The antifogging agent composition may also contain a crosslinking compound that crosslinks the binder components. By doing so, the water resistance of the anti-fog coating can be improved. As the crosslinking compound, the same compounds used in the above-mentioned antifogging coating composition can also be used in the antifogging agent composition. The amount of crosslinking compound used is 0.1% of the solid content of the binder component.
A range of up to 30% by weight is preferred, especially a range of 0.5 to 10% by weight. Further, the antifogging agent composition can be mixed with antifoaming agents, lubricants, antistatic agents, and other various additives that can be used in the above-mentioned dustproof coating compositions, if necessary. Therefore, antifogging agent compositions are usually used in liquid form. The liquid dispersion medium includes an affinity or water-miscible solvent containing water; water; monohydric alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; polyhydric alcohols such as ethylene glycol, diethylene glycol, and glycerin; Examples include cyclic alcohols such as benzyl alcohol; cellosolve acetates; ketones and the like. These may be used alone or in combination, but the dispersion stability of the antifogging agent composition used in the present invention, the wettability after coating on the film surface, the difficulty of removing the liquid dispersion medium, and the economic efficiency should be taken into consideration. It is preferable to decide accordingly. In addition, the coating film of the antifogging agent composition formed on the surface of the base film is generally
A range of 0.01 to 10 g/m ² , particularly 0.1 to 5 g/m ² is preferred. To form a film of a dustproof coating composition and an antifogging composition on the surface of a base film, a solution or dispersion of each composition is generally coated by a doctor blade coating method, a roll coating method, a dip coating method, or a spray coating method. , rod coat method, bar coat method,
A known coating method such as a knife coating method or a brush coating method may be employed, and the coating may be dried after coating. Regarding the drying method after application, in the case of a dust-proof coating composition, it is necessary to heat dry it due to the physical properties of the coating, and the heating temperature is 50℃.
It is preferable to hold the temperature in the range of ~150°C for 10 seconds to 10 minutes, and in the case of an antifogging agent composition, either natural drying or forced drying may be adopted.
When using forced drying method, the temperature is usually 50~250℃,
It is preferable to dry at a temperature range of 70 to 200°C. For heating drying, hot air drying method, infrared drying method,
An appropriate method such as a far-infrared drying method may be employed, and in consideration of drying speed and safety, it is advantageous to employ a hot air drying method. The dust-proof coating composition can also be formed into a film by coextruding the composition itself with a base film, or by extrusion coating, extrusion lamination, etc. on the base film, instead of making it into a solution. . The order in which the coating composition and the antifogging agent composition are formed on the surface of the base film is determined in consideration of heating conditions and the like. In addition, if the adhesion between the base film and the coating derived from both compositions is insufficient, the surface of the base film may be washed with alcohol or water in advance, or
Pretreatment such as plasma discharge treatment, corona discharge treatment, or undercoating with another paint or primer may be performed. "Effects of the Invention" The present invention has the following particularly remarkable effects, and its industrial utility value is extremely large. (1) Since the agricultural soft vinyl chloride resin film according to the present invention has a coating formed on both surfaces of the film, the plasticizer added to the film,
Migration of various resin additives to the film surface can be suppressed. Therefore, the flexibility of the film can be maintained over a long period of time, and
There is little dust adhesion to the film surface (especially the outside surface when used as a house or tunnel).
The dustproof effect lasts for a long period of time, over three years. (2) In the agricultural soft vinyl chloride resin film according to the present invention, a coating derived from an antifogging composition is formed on one surface of the film, and the coating of the antifogging composition is applied to a house, etc. When stretched on the inside of the screen, it functions to suppress the adhesion of water droplets, and the anti-fog effect lasts for a long period of time. (3) The agricultural soft vinyl chloride resin film according to the present invention suppresses the migration of plasticizer to the film surface, so there is little loss of flexibility, excellent durability, and the frequency of film re-covering is reduced. , the problem of abandoned agricultural biofilms is alleviated, resources are saved, and the cost of installing agricultural and horticultural greenhouses is reduced. "Examples" Next, the present invention will be described in detail based on Examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Examples 1 to 6, Comparative Examples 1 to 6 (1) Preparation of base film Polyvinyl chloride (=1400) 100 parts by weight Dioctyl phthalate 50 Tricresyl phosphate 5 Epoxidized soybean oil 1 Ba/Zn system Composite stabilizer 1.5 〃 Barium stearate 0.2 〃 Zinc stearate 0.4 〃 Sorbitan monolaurate 1.5 〃 2,4-dihydroxybenzophenone
0.6 〃 Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate 0.4 〃 The above mixture was stirred and mixed in a super mixer for 10 minutes, and then kneaded on a mill roll heated to 180°C. A base film with a thickness of 0.15 mm was prepared. (2) Preparation and production examples of acrylic resins 1 to 4 Into a reactor equipped with a thermometer, a stirrer, a reflux condenser, and a nozzle for adding raw materials, add 100 parts by weight of isopropyl alcohol, 1.0 parts by weight of benzoyl peroxide, and Table 1. Add 100 parts by weight of the mixture of each monomer shown in , and while stirring in a nitrogen gas stream,
0.5 parts by weight of benzoyl peroxide was further added at 80° C. for 3 hours, and the reaction was continued at the same temperature for about 3 hours to obtain acrylic resins A to D.

【table】

[Table] (3) Formation of film of coating composition Silane compounds of the types and amounts shown in Table 2,
An acrylic resin and a crosslinkable compound were blended, and isopropyl alcohol was added thereto so that the solid content was 20% by weight to obtain a coating composition. However, in Comparative Example 1, no silane compound was blended. Furthermore, in Comparative Example 2, no acrylic resin was blended. The coating composition was applied to one side of each base film prepared by the method (1) above using a #5 bar coater. Heat the coated film to 130℃
The sample was held in an oven for 3 minutes to volatilize the solvent and simultaneously perform heat treatment. The amount of coating on each film obtained was approximately 2 g/m ² . (4) Formation of film of antifogging agent composition An antifogging agent composition is obtained by blending the main components (colloidal silica and/or alumina sol) shown in Table 2, a binder component, a crosslinking agent, and a liquid dispersion medium. Ta. However, in Comparative Example 3, the main component was not blended. Further, in Comparative Example 4, no binder component was blended. The above antifogging agent composition was applied to the other side of the base film on which the dustproof coating was formed using a #5 bar coater. The coated film was kept in an oven at 80° C. for 1 minute to volatilize the liquid dispersion medium. The amount of coating on each film obtained was approximately 1 g/cm ² . In addition, in Comparative Example 5, neither a coating derived from the coating composition nor a coating derived from the antifogging agent composition was formed on the film.

【table】

[Table] Antifogging agent composition (main component) in Table 2 OSCAL-1432 is a solvent-dispersed colloidal silica manufactured by Catalysts & Chemicals Co., Ltd. Cataloid SI-80P and Cataloid SI-30 are water-dispersed colloidal silica manufactured by Catalysts & Chemicals Co., Ltd. Alumina Sol-520 is a water-dispersed alumina sol manufactured by Nissan Chemical Industries, Ltd. <Binder component> Dianal BR-101 is a thermoplastic acrylic resin manufactured by Mitsubishi Rayon Co., Ltd. Karakrylic Resin H-300 is an acrylic emulsion manufactured by Nippon Kayaku Kogyo Co., Ltd. Metrose 65SH50 is a water-soluble cellulose ether manufactured by Shin-Etsu Chemical Co., Ltd. <Crosslinking agent> Epiclon 860 is a crosslinking agent whose active ingredient is a bisphenol A type epoxy compound manufactured by Dainippon Ink and Chemicals. TAZM is the above-mentioned aziridine compound. (5) Evaluation of film The performance of the agricultural soft vinyl chloride resin film was evaluated by the following method, and the results are shown in Table 3. Dust-proofing 12 types of films were installed in a pipe house (width 3m, depth 5m, ridge height 1.5m, roof slope 30 degrees) in a test field in Isshi District, Mie Prefecture.
It was coated with the coat of coating composition on the outside. The unfolded film is collected over time and the wavelength
The light transmittance at 555 mm was measured using a spectrophotometer (manufactured by Hitachi, Model EPS-2U). The measurement results were displayed as follows. ◎…Things with a light transmittance of 80% or more. ○...Light transmittance is in the range of 65-79%. △...Things with light transmittance in the range of 45 to 64%. ×...Light transmittance is less than 45%. Dust resistance The state of adhesion of water droplets on the surface of the 12 types of stretched films on which the antifogging agent composition coating was formed was visually observed over time. The evaluation criteria are as follows. ◎…Film surface (side facing the inside of the house)
Water droplets adhering to the film coalesce and spread into a thin film, and the area of this thin film covers more than half of the film surface (same as above). ○...Water droplets adhering to the film surface (same as above) are observed to coalesce and spread into a thin film, but the area of this thin film is less than 1/2 of the film surface (same as above). △: Coalescence of water droplets adhering to the film surface (same as above) is observed, but the shape of a thin film-like portion is not observed. ×: Coalescence of water droplets attached to the film surface (same as above) is not observed. Durability The stretched film was collected over time, the elongation was measured, and the elongation retention rate was calculated using the following formula. Elongation of film after outdoor expansion/Elongation of film before outdoor expansion x 100 (%) The results were displayed as follows. ◎…Elongation retention rate is 80% or more. ○...Elongation retention rate is in the range of 60 to 79%. △...The elongation retention rate is in the range of 40 to 59%. ×...Elongation retention rate is less than 40%.

【table】

[Table] From Table 3, the following becomes clear. (1) Comparative Example 1, Comparative Example 2, and Comparative Example 6 are good in terms of antifogging properties, but poor in dustproof properties, and
Perhaps because resin additives such as plasticizers bleed out through the dustproof coating over time, the flexibility of the film is poor, resulting in poor durability. (2) In Comparative Examples 3 and 4, there was no dust adhering to the outer surface of the house, and the dust resistance was excellent when observed with the naked eye, but the adhesion of the anti-fog coating was poor, so the coating itself was washed away. Furthermore, over time, additives for resins such as plasticizers bleed out and are washed away, resulting in dirt adhering to the inner surface of the house, which has an anti-fogging coating, and reducing dust resistance as measured by transmitted light. It makes the value of sex inferior. Furthermore, the above (1)
Similarly, the film has poor flexibility and durability. (3) On the contrary, the agricultural soft vinyl chloride resin film of the present invention has an anti-fog coating and a dust-proof coating formed on the inner and outer surfaces, respectively, and bleeds over time of resin additives such as plasticizers.・It has a structure that is ideal for use as an agricultural film, with little outflow, excellent anti-fog and dust-proof properties even after long-term use, and excellent durability.

Claims (1)

[Scope of Claims] 1. A coating derived from a coating composition containing a silane compound having a hydrolyzable group directly bonded to a silicon atom or a hydrolyzate thereof and an acrylic resin is formed on one side of a soft vinyl chloride resin film. colloidal silica and/or on the other side of the film.
Alternatively, a soft vinyl chloride resin film for agricultural use is formed by forming a film derived from an antifogging agent composition containing an alumina sol and a binder as main components. 2. The agricultural soft vinyl chloride resin film according to claim 1, wherein the binder component is an acrylic resin.