JPH053831B2 - - Google Patents

Description

[Detailed description of the invention]

"Field of Industrial Application" The present invention relates to a vinyl chloride resin film for agricultural use. More specifically, the present invention relates to an agricultural vinyl chloride resin film that has improved durability against undesirable deterioration phenomena such as discoloration, embrittlement, and reduced dust resistance caused by outdoor stretching. . ``Conventional technology'' In recent years, farmers cultivating useful plants have been growing them in greenhouses (greenhouses), in order to improve profitability.
Alternatively, methods of promoting or suppressing cultivation in tunnels have become widely adopted. Polyethylene films, ethylene-vinyl acetate copolymer films, polyester films, polycarbonate films, hard and soft vinyl chloride resin films, glass, and the like are used as covering materials for greenhouses or tunnels. Among these, soft vinyl chloride resin film is widely used because it has the best overall light transmittance, heat retention, mechanical strength, durability, and workability compared to other synthetic resin films. ing. However, synthetic resin films used as covering materials for greenhouses or tunnels, including vinyl chloride resins, can be affected by sunlight, especially ultraviolet rays, after one year of use as covering materials. As a result, changes occur over time, such as deterioration of the appearance and a decrease in the flexibility of the film. Furthermore, recent improved agricultural technology, particularly agricultural technology oriented towards economy and labor saving, has come to require coating materials to have properties that can withstand even harsher conditions than in the past. In order to prevent photodeterioration of vinyl chloride resin films conventionally used as coating materials for greenhouses or tunnels due to sunlight, UV absorbers and/or antioxidants are added to the base vinyl chloride resin. A technique of blending and forming a film is widely employed (see, for example, Japanese Patent Publication No. 48-37459, Japanese Patent Publication No. 53-47383, etc.). According to this method, harmful light rays that promote film deterioration are gradually absorbed and weakened as they pass through the film from the incident side to the opposite side.
In this case, the side of the film on which the light rays are incident is damaged by harmful rays, resulting in the drawback that the weather resistance of the film cannot be sufficiently improved. On the other hand, based on conventional experience, soft vinyl chloride resin films used for agricultural purposes are spread to different degrees depending on the region and place where they are used.
After two years have passed since the start of use, the dust-proofing properties of the outside surface of the house or tunnel deteriorate significantly, and it becomes unusable. As a way to eliminate the above drawbacks,
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. On the other hand, fluoroplastics have excellent stain resistance, non-stick properties, and weather resistance compared to other thermoplastic resins, so fluorocarbon resins are laminated on the surface of PVC resin molded products. Attempts have been made. However, since fluororesin is inherently non-adhesive, it is difficult to adhere it to other base materials. For this reason,
In order to improve the adhesion between fluororesins and other base materials, various methods have been studied in the past. For example, a method has been proposed in which a fluororesin and another base material are bonded together using an adhesive resin. Specific ethylene-ethyl acrylate copolymers, ethylene-vinyl acetate copolymers, or modified products thereof
-86748, JP-A-57-12645),
Epoxy group-containing polyolefin (JP-A-57-8155
(Refer to JP-A-57-212055), a resin composition of a copolymer grafted with vinylidene fluoride and a methyl methacrylate polymer (JP-A-57-212055);
12646), polymers consisting of partially modified ethylene polymers and alkyl acrylate polymers (see JP-A-59-214645), resins in which thermoplastic acrylic resins are modified or mixed with specific resins. A method of improving the adhesion between a fluororesin and other base materials by using a composition is disclosed.
However, in the case of soft vinyl chloride resin films, it is generally not practical to bond them with fluororesin through adhesive resins due to the transfer and ejection of compounding agents such as plasticizers to the molded product surface. It wasn't enough. On the other hand, by mixing fluororesin and adhesive resin,
Methods of coating other base materials have been proposed. For example, JP-A-57-182352 discloses a method using a composition comprising a polyamideimide resin and a fluororesin. "Problems to be Solved by the Invention" Under such circumstances, the present inventors have found that undesirable deterioration such as discoloration, embrittlement, and reduction in dustproof and antifogging properties caused by spreading outdoors With the aim of providing an agricultural vinyl chloride resin film in which the phenomenon has been significantly improved and durability has been improved, the present invention has been completed as a result of intensive studies. "Means for Solving the Problems" The above problems can be solved by using the agricultural vinyl chloride resin film according to the present invention. That is, the gist of the present invention is to coat one or both sides of a soft vinyl chloride resin film containing an ultraviolet absorber with a coating composition in which a specific acrylic resin is mixed with a vinylidene fluoride resin. The present invention relates to an agricultural vinyl chloride resin film characterized by being formed with a coating. The present invention will be explained in detail below. In the present invention, vinyl chloride resin refers to polyvinyl chloride, as well as monomer compounds that can be copolymerized with vinyl chloride, including copolymers in which vinyl chloride is the main component, such as vinylidene chloride, ethylene, propylene, Examples include 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 flexibility to the vinyl chloride resin that serves as the base, 100 parts by weight of this resin is added.
20 to 60 parts by weight of plasticizer are incorporated. By adjusting the amount of the plasticizer within the above range, it is possible to impart excellent flexibility and mechanical properties to the target vinyl chloride resin film. 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 dioctyl phthalate; Adipic acid derivatives such as di-n-butyl adipate and dioctyl adipate; Di-n-butyl maleate, etc. Maleic acid derivatives; citric acid derivatives such as tri-n-butyl citrate; itaconic acid derivatives such as monobutyl itaconate; oleic acid derivatives such as butyl oleate;
Other examples include ricinoleic acid derivatives such as glycerin monoricinolate; phosphate ester plasticizers such as tricresyl phosphate and tricylenyl phosphate; epoxidized soybean oil and epoxy resin plasticizers. The agricultural vinyl chloride resin film according to the present invention contains an ultraviolet absorber. The usable ultraviolet absorbers are particularly preferably benzophenone ultraviolet absorbers and/or benzotriazole ultraviolet absorbers, and specific examples include the following. Benzophenone ultraviolet absorber--2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4
-n-octoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-benzoyloxy benzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfone benzophenone,
2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-5-chlorobenzophenone, bis-(2-methoxy -4-hydroxy-5-benzoylphenyl)methane. Benzotriazole ultraviolet absorber--2-
(2′-hydroxyphenyl)benzotriazole,
2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-
methylphenyl)-5-carboxylic acid butyl ester benzotriazole, 2-(2'-hydroxy-
5'-methylphenyl)-5,6-dichlorobenzotriazole, 2-(2'-hydroxy-5'-methylphenyl)-5-ethylsulfonebenzotriazole, 2-(2'-hydroxy-5'-t-butylphenyl) )-5-chlorobenzotriazole, 2
-(2'-hydroxy-5'-t-butylphenyl)
Benzotriazole, 2-(2'-hydroxy-
5′-aminophenyl)benzotriazole, 2-
(2'-hydroxy-3',5'-dimethylphenyl)benzotriazole, 2-(2'-hydroxy-3',
5'-dimethylphenyl)-5-methoxybenzotriazole, 2-(2'-methyl-4'-hydroxyphenyl)benzotriazole, 2-(2'-stearyloxy-3',5'-dimethylphenyl) )-5
-Methylbenzotriazole, 2-(2'-hydroxy-5-carboxylic acid phenyl)benzotriazole ethyl ester, 2-(2'-hydroxy-
3'-Methyl-5'-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-
t-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-methoxy phenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5
-chlorobenzotriazole, 2-(2'-hydroxy-5'-cyclohexylphenyl)benzotriazole, 2-(2'-hydroxy-4',5'-dimethylphenyl)-5-carboxylic acid benzotriazole butyl ester , 2-(2'-hydroxy-3',
5′-dichlorophenyl)benzotriazole, 2
-(2'-hydroxy-4',5'-dichlorophenyl)
Benzotriazole, 2-(2'-hydroxy-3',
5'-dimethylphenyl)-5-ethylsulfonebenzotriazole, 2-(2'-hydroxy-4'-
octoxyphenyl)benzotriazole, 2-
(2'-hydroxy-5'-methoxyphenyl)-5-
Methylbenzotriazole, 2-(2'-hydroxy-5'-methylphenyl)-5-carboxylic acid ester benzotriazole, 2-(2'-acetoxy-5'-methylphenyl)benzotriazole. The amount of the above ultraviolet absorber added to the base film is based on 100 parts by weight of the base vinyl chloride resin.
The range is 0.02 to 8 parts by weight. If the amount is less than 0.02 part by weight, the weather resistance of the agricultural vinyl chloride resin film will not be sufficiently excellent, which is not preferable. On the other hand, if the amount is more than 8 parts by weight, the problem arises that the resin may be blown out onto the surface of the film together with other resin additives when the film is used, which is not preferable. Among the above ranges, a range of 0.1 to 3 parts by weight is particularly preferred. In addition to the plasticizer and ultraviolet absorber, a surfactant may be added to the vinyl chloride resin, if necessary. Specific examples include sorbitan laurate, sorbitan myristate, sorbitan palmitate, sorbitan stearate, sorbitan isostearate, sorbitan behenate,
Sorbitan esters of fatty acids such as sorbitan oleate, sorbitan hydroxystearate, ethylene oxide adducts of sorbitan palmitate, ethylene oxide adducts of sorbitan stearate, polyoxyethylene nonyl phenyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters,
Examples include sugar esters and cellulose ethers. These surfactants may contain at least one type or two.
More than one type may be mixed and used. In addition to the surfactant, the vinyl chloride resin may also contain, if necessary, known resin additives that are usually added to synthetic resins for molding, such as light stabilizers, antioxidants, and heat stabilizers. Stabilizers, lubricants, pigments, dyes, etc. can be added. As a light stabilizer, 4-acetoxy-2,2,
6,6-tetramethylpiperidine, 4-cyclohexanoyloxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,
6,6-tetramethylpiperidine, bis(2,
2,6,6-tetramethyl-4-piperidyl)adipate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, tris(2,
2,6,6-tetramethyl-4-piperidyl)benzene-1,3,5-tricarboxylate, tetrakis(2,2,6,6-tetramethyl-4-
Examples include hindered amine compounds such as (piperidyl)propane-1,1,2,3-tetracarboxylate. Antioxidants that can be used include 2,6-di-
tert-butyl-4-methylphenol, 2,2'-
Examples include methylenebis(6-tert-butyl-4-ethylphenol) and dilaurylthiodipropionate. Examples of lubricants or heat stabilizers that can be used include polyethylene wax, liquid paraffin, stearic acid, zinc stearate, fatty alcohols, calcium stearate, barium stearate, barium ricinoleate, dibutyltin dilaurate, dibutyltin dimaleate, organic Examples include metal phosphates, organic phosphite compounds, phenols, and β-diketone compounds. Examples of colorants that can be used include phthalocyanine blue, phthalocyanine green, Hansa yellow, alizarin lake, zinc oxide titanium oxide, permanent red, quinacridone, and carbon black. These resin additives can be used in a usual amount, for example, 10 parts by weight or less per 100 parts by weight of the vinyl chloride resin. In order to blend an ultraviolet absorber, a plasticizer, or, if necessary, the above-mentioned resin additives into the base vinyl chloride resin, a conventional blending or mixing technique may be employed. Specifically, for example, a method using a ribbon blender, Banbury mixer, super mixer, or other blender or mixer can be adopted. In order to manufacture a base film from the soft vinyl chloride resin composition obtained in this way, commonly used film manufacturing methods such as calender molding, extrusion molding, and inflation molding can be used as appropriate. Can be adopted. If the thickness of the base film is too thin, the strength will be insufficient, which is undesirable.On the other hand, if it is too thick, it will be inconvenient in the film forming process and subsequent handling, so the thickness should be in the range of 0.03 to 0.3 mm, preferably 0.05 mm. ~
A range of 0.2 mm is recommended. In the present invention, the acrylic resin refers to 5 to 40% by weight of hydroxyalkyl (meth)acrylate,
α,β-unsaturated carboxylic acid compound containing one or more carboxyl groups in the molecule 0-20
% by weight and refers to a polymer obtained by copolymerizing these compounds with other copolymerizable vinyl compounds. The term hydroxyalkyl (meth)acrylate as used herein means hydroxyalkyl acrylate or hydroxyalkyl methacrylate. Hydroxyalkyl (meth)acrylates include hydroxymethyl acrylate, hydroxymethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate,
2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-
Examples include hydroxybutyl methacrylate, 2-hydroxypentyl acrylate, 2-hydroxypentyl methacrylate, 6-hydroxyhexyl acrylate, and 6-hydroxyhexyl methacrylate. If the proportion of these hydroxyalkyl (meth)acrylates in the acrylic resin is less than 5% by weight, the solubility with organic solvents, the adhesion with the base molded product, and the effect of inhibiting plasticizer migration may not be fully exhibited. I don't like it because I don't get it. On the other hand, if the amount is more than 40% by weight, the cost will increase and the effect obtained will not be large compared to the increased cost, which is not preferable. Examples of α,β-unsaturated carboxylic acid compounds containing one or more carboxyl groups in the molecule include acrylic acid, methacrylic acid, itaconic acid, maleic acid, aconitic acid, and crotonic acid. When these compounds are used in combination with the above-mentioned hydroxyalkyl (meth)acrylates, the adhesion between the coating composition in which acrylic resin is mixed with vinylidene fluoride resin and the vinyl chloride resin base film is improved, and the films do not adhere to each other. Demonstrates the effect of suppressing matching (blocking) properties. The amount of these compounds used is up to 20% by weight. If it is more than this, the property of the films adhering to each other when they are wet with moisture (wet blocking property) will be strengthened, which is not preferable. Other vinyl compounds that can be copolymerized with the above compounds that make up the remainder include methyl acrylate,
Acrylic acids such as ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, dodecyl acrylate, tridecyl acrylate, stearyl acrylate, etc. _C1 - _C22 alkyl esters: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i
- methacrylic acids such as propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, stearyl methacrylate, etc.
_C1 - _C22 alkyl esters: styrene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, acrylamide, methacrylamide, n-butoxyacrylamide, n
-Butoxy methacrylamide, etc. can be mentioned. The acrylic resin to be mixed with the vinylidene fluoride resin is prepared by combining two or more of the above monomers in a predetermined amount, charging the mixture together with an organic solvent into a polymerization tank, adding a polymerization initiator and, if necessary, a molecular weight regulator. , heated while stirring to polymerize. In this case, examples of polymerization initiators that can be used include radical-generating catalysts such as α,α-azobisisobutyronitrile, benzoyl peroxide, and cumene hydroperoxide, and examples of molecular weight regulators include butyl mercaptan and n- dodecyl mercaptan,
Examples include tert-dodecylmercaptan and β-mercaptoethanol. Organic solvents used for polymerization include methanol,
Ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-
Alcohols such as butanol, n-amyl alcohol, isoamyl alcohol, tert-amyl alcohol, n-hexyl alcohol, and cyclohexanol; Aromatic hydrocarbons such as benzene, toluene, and xylene; Acetic esters such as ethyl acetate and butyl acetate Ketones such as acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, 2-hexanone, 3-hexanone, di-n-propyl ketone, diisopropyl ketone, di-n-amyl ketone, cyclohexanone; tetrahydrofuran These can be used alone or in combination of two or more. Vinylidene fluoride resin is a homopolymer of vinylidene fluoride, or a copolymer of vinylidene fluoride and other fluorine-based unsaturated monomers and/or fluorine-free copolymerizable monomers. Polymers obtained by combining these polymers and partially modifying or modifying these polymers are also included. These vinylidene fluoride resins may be used alone or in combination of two or more, or may be used in combination with other fluorine-containing resins and/or fluorine-free resins. The blending ratio of the acrylic resin and the vinylidene fluoride resin is preferably 1 to 90 for the former and 99 to 10 for the latter (the total amount of both being 100) in terms of solid weight ratio, and is particularly preferable. The ratio is 5-80 to 95-20. If the ratio of the former is higher than this, the resulting coating will not have sufficient effects on the migration prevention properties of plasticizers, etc., stain resistance, and water resistance; The adhesion to the film is poor, and the film easily peels off, which is undesirable. In addition to these components, the coating composition may contain auxiliary components such as antioxidants, neutralizers, ultraviolet absorbers, light stabilizers, antistatic agents, pigments, dyes, and lubricants. . The above coating composition can be used after being dispersed and/or dissolved in an organic solvent. Particularly preferred organic solvents include acetone, tetrahydrofuran, methyl ethyl ketone, dimethyl formamide, dimethyl acetamide, tetramethyl urea, trimethyl phosphate, etc., and preferred examples include methyl isobutyl ketone, butyl acetate, cyclohexanone, diacetone alcohol. , diisobutyl ketone, γ-butyrolactone, tetraethyl urea, isophorone, diethylene glycol monoethyl ether acetate, propylene carbonate, dimethyl phthalate, etc., and these can be used alone or in combination of two or more. In addition, if the amount used is small, for example, aliphatic hydrocarbons such as heptane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, alcohols such as methanol, ethanol and isopropyl alcohol, and halogens such as chloroform and tetrachlorinated hydrocarbons. Hydrocarbons, etc. can be used alone or in combination of two or more. Various generally known methods can be applied to apply the above coating composition to form a film on the surface of the soft vinyl chloride resin base film. For example, when forming a film in a solution state, coating methods such as doctor blade coating, gravure roll coating, air knife coating, reverse roll coating, dip coating, curtain roll coating, spray coating, and rod coating can be used. is used.
When the coating composition is formed as a single film without being in a solution state, a coextrusion method, an extrusion coating method, an extrusion lamination method, and a lamination method are used. When a coating method is used as a film forming method, there are, for example, natural drying methods, hot air drying methods, infrared drying methods, far infrared drying methods, etc. However, considering drying speed and safety, Hot air drying methods are advantageous. In this case, the temperature condition should be in the range of 50 to 150°C, and the time should be selected in the range of 10 seconds to 15 minutes. When applying the above coating composition to the surface of a soft vinyl chloride resin base film to form a film, the coating amount 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. In addition, before applying the above-mentioned coating composition, the surface of the soft vinyl chloride resin film may be washed with alcohol or water, subjected to plasma discharge treatment or corona discharge treatment, or undercoated with other paint or primer. Pretreatment such as the following may be performed. When the agricultural vinyl chloride resin film according to the present invention is actually used for agricultural purposes, if the coating is formed on only one side, the side on which this coating is provided should be placed on the side of the greenhouse or tunnel. Use it so that it is on the outside. "Function" The agricultural vinyl chloride resin film according to the present invention has a coating derived from a specific coating composition formed on its surface, and this coating prevents the various resin additives blended into the film from seeping out. Even if the film is stretched outdoors for a long period of time, there will be little surface contamination and little decrease in light transmittance. This film also has excellent adhesion. Furthermore, since the base film contains an ultraviolet absorber, it has a high elongation retention rate and excellent durability. "Examples" The present invention will be described in detail based on Examples below, but the present invention is not limited to the following Examples unless it goes beyond the scope of the invention. Examples 1 to 6, Comparative Examples 1 to 5 Preparation of base film Polyvinyl chloride (=1400) 100 parts by weight Dioctyl phthalate 50 Epicote 828 (epoxy compound, trade name manufactured by Shell, USA) 1 Tricresyl phosphate ( Phosphate ester plasticizer) 5 Ba/Zn composite stabilizer 1.5 Barium stearate (stabilizer) 0.2 Zinc stearate 0.4 Sorbitan monolaurate 1.5 A resin composition was prepared and prepared as shown in Table 1. The types and amounts of ultraviolet absorbers shown in 1 were blended. However, in Comparative Examples (1, 2), it was not blended. Each formulation was stirred and mixed using a super mixer for 10 minutes, and then kneaded on a mill roll heated to 180°C to prepare a base film with a thickness of 0.15 mm. Preparation of acrylic resin A: In a reactor equipped with a thermometer, stirrer, reflux condenser, and charging nozzle, add 15 parts by weight of 2-hydroxyethyl methacrylate, 5 parts by weight of acrylic acid, 45 parts by weight of methyl methacrylate, and n-butyl acrylate. 35 parts by weight, 1 part by weight of benzoyl peroxide, and 200 parts by weight of methyl ethyl ketone were added, and while stirring in a nitrogen gas stream,
The mixture was reacted at ℃ for 7 hours to obtain an acrylic resin solution. This is called acrylic resin (A). B Into the same reactor used in the example described in section A, 10 parts by weight of 2-hydroxyethyl acrylate, 3 parts by weight of methacrylic acid, 60 parts by weight of methyl methacrylate, 27 parts by weight of butyl methacrylate, 1 part by weight of benzoyl peroxide. , 200 parts by weight of methyl ethyl ketone were charged and reacted in the same manner as described in Section A to obtain an acrylic resin solution. This is called acrylic resin (B). C Into the same reactor used in the example described in Section A, 55 parts by weight of methyl methacrylate, 40 parts by weight of butyl methacrylate, 5 parts by weight of butyl acrylate were added.
parts by weight, 1 part by weight of benzoyl peroxide,
200 parts by weight of methyl ethyl ketone was charged and reacted in the same manner as described in Section A to obtain an acrylic acid resin solution. This is acrylic resin (C)
shall be. Formation of Coating A coating composition was obtained by blending acrylic resin and vinylidene fluoride resin in the types and amounts shown in Table 1, and adding methyl ethyl ketone to the mixture so that the solid content was 20% by weight. However, in Comparative Example 3, no acrylic resin was blended. Furthermore, in Comparative Example 4, vinylidene fluoride resin was not blended. On one side of the base film prepared by the above method,
The above coating composition was applied using a #5 bar coater,
Each was applied. The coated film was kept in an oven at 130° C. for 1 minute to volatilize the solvent.
The amount of coating on each film obtained was approximately 3 g/m ² . However, in Comparative Example 1, no film was formed. Evaluation of Film The evaluation results of each Example and Comparative Example are listed in Table 1. Each evaluation method is as follows. Adhesion Cellophane tape was adhered to the surface of the film on which the coating was formed, and when the cellophane tape was peeled off, the peeling status of the coating was observed with the naked eye. The evaluation criteria are as follows. ◎...The coating did not peel off at all and remained completely. 〇…More than 2/3 of the film remains without being peeled off. △: Part of the film remained without being peeled off. x: The coating was completely peeled off. Outdoor expansion test Eleven types of films were placed in a roof-shaped greenhouse (opening 3m, depth 5m,
A ridge height of 1.5 m and a roof slope of 30 degrees) was coated with the coated side facing the outside of the house, and a two-year expansion test was conducted from March 1980 to February 1988. The stretched film was subjected to a film appearance test and the elongation retention rate of the film was measured by the following method, and the dust resistance of the film during the stretching test was evaluated. Film appearance: Appearance observed with the naked eye. The evaluation criteria are as follows. ◎…No change in appearance such as discoloration is observed. 〇…Some changes in appearance such as slight discoloration are observed. △...Significant changes in appearance such as discoloration are observed. ×: Discoloration is observed on the entire surface. Elongation retention rate of film...means a value calculated by the following formula. Elongation of film after outdoor expansion/Elongation of film before outdoor expansion x 100 (%) Dustproof property: means the value calculated by the following formula. Light transmittance of film collected over time after outdoor expansion/
Light transmittance of the film before outdoor expansion *×100 (%) * Direct light transmittance at a wavelength of 555 μm (manufactured by Hitachi, Ltd., EPS-2U type used) The measurement results were displayed as follows. ◎...Light transmittance after expansion is 90% or more of that before expansion. 〇…The light transmittance after expansion is in the range of 70 to 89% of that before expansion. △...The light transmittance after stretching is in the range of 50 to 69% of that before stretching. ×...The light transmittance after expansion is less than 50% of that before expansion.

【table】

[Table] "Effects of the Invention" As is clear from the examples above, the present invention has the following effects:
It has the following effects and has extremely great industrial utility value. (1) Even if the agricultural vinyl chloride resin film according to the present invention is spread outdoors for a long time, it will not change color or
There is little deterioration in physical properties and dust resistance, and it can withstand long-term use. (2) Since the agricultural vinyl chloride resin film according to the present invention has excellent adhesion between the base film and the coating derived from the fluorine resin coating composition formed on the surface thereof, the coating is difficult to peel off. Withstands long-term use.

Claims (1)

[Claims] 1. On one or both sides of a soft vinyl chloride resin film containing an ultraviolet absorber, 5 to 40% by weight is a hydroxyalkyl (meth)acrylate monomer, and 0 to 20% by weight is one hydroxyalkyl (meth)acrylate monomer in the molecule. Alternatively, an acrylic resin obtained by copolymerizing a monomer component consisting of an α,β-unsaturated carboxylic acid containing two or more carboxyl groups and another vinyl compound whose remainder can be copolymerized with these compounds, An agricultural vinyl chloride resin film comprising a coating derived from a coating composition mixed with a vinylidene fluoride resin. 2. The agricultural vinyl chloride resin film according to claim 1, wherein the ultraviolet absorber is a benzophenone-based and/or benzotriazole-based compound.