JPH0460823B2 - - 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 prevents undesirable deterioration phenomena such as discoloration, embrittlement, and reduction in dust resistance caused during outdoor spreading, and has improved durability. "Prior Art" Conventionally, for the purpose of preventing the photodeterioration phenomenon caused by sunlight etc. of vinyl chloride resin films used as coating materials for agricultural greenhouses or tunnels,
The technology of adding and blending ultraviolet absorbers or antioxidants to the base vinyl chloride resin to form a film is widely adopted (for example, see 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 in which a specific acrylic resin is formed 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 coating 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 preferably used as a cationically polymerized energy beam-curable resin composition according to this method is susceptible to weather resistance deterioration, and cannot sufficiently achieve the intended purpose. There was a drawback that there was no. "Problems to be Solved by the Invention" Under such circumstances, the present inventors have discovered that undesirable deterioration phenomena such as discoloration, embrittlement, and reduction in dust resistance caused by outdoor expansion are With the aim of providing an agricultural vinyl chloride resin film that is significantly improved and has improved durability, the present invention has been completed as a result of intensive studies. "Means for Solving the Problems" Therefore, the gist of the present invention is that [A] A film of a composition whose main components are a silane compound having a hydrolyzable group directly bonded to a silicon atom, [B] a specific acrylic resin, and [C] a crosslinkable compound is formed under heat treatment. This is an agricultural vinyl chloride resin film. 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 setting the blending 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; other examples include epoxidized soybean oil and epoxy resin plasticizers. The agricultural vinyl chloride resin film of the present invention is
An organic phosphate ester or an organic phosphate metal salt is blended with the vinyl chloride resin. Examples of organic phosphoric acid esters include triisopropylphenyl phosphate, isodecyl diphenyl phosphate, tricresyl phosphate, tris(isopropylphenyl) phosphate, tributyl phosphate, triethyl phosphate, trioctyl phosphate, and tributoxyethyl. Examples include phosphate, triphenyl phosphate, octyl diphenyl phosphate, and tricylenyl phosphate, among which tricresyl phosphate and tricylenyl phosphate are particularly preferred. In the agricultural film of the present invention, a composite material containing an organic phosphate ester as a main component can also be used. For example, a composite of an organic phosphoric acid ester and an organic phosphorous ester can be mentioned. Also included are phosphonate compounds such as diphenylphosphonate. These are generally plasticizers for vinyl chloride resins, and they improve the weather resistance of the film.
Combined with the formed film, it improves dust resistance. These organic phosphate esters can be used alone or in combination of two or more. As the organic phosphate metal salt, the general formula [] or [] (In the formula, M means zinc, calcium, barium, magnesium, cobalt or strontium. Also, R ¹ , R ² and R ³ each represent an alkyl, aryl, arylalkyl, alkylaryl or ether bond. (means an alkyl group having an alkyl group). Examples of the alkyl group represented by R ¹ , R ² and R ³ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, amyl, neopentyl, isoamyl, hexyl, isohexyl, heptyl, Examples include octyl, isooctyl, 2-ethylhexyl, decyl, isodecyl, lauryl, tridecyl, _C12 - _C13 mixed alkyl, stearyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, 4-methylcyclohexyl, and the like. Examples of aryl groups include phenyl and naphthyl groups. Examples of arylalkyl groups include benzyl,
β-phenylethyl, α-phenylpropyl, β
-phenylpropyl group and the like. Examples of alkylaryl groups include tolyl, xylyl, ethyl phenyl, butylphenyl, tertiary
Examples include butylphenyl, octylphenyl, isooctylphenyl, tertiary octylphenyl, nonylphenyl, 2,4-di-tertiary butylphenyl, and the like. Examples of the alkyl group having an ether bond include furfuryl, tetrahydrofurfuryl, 5-methylfurfuryl and α-methylfurfuryl, or
Methyl, ethyl, isopropyl, butyl, isobutyl, hexyl, cyclohexyl, phenyl cellosolve residue; methyl, ethyl, isopropyl, butyl, isobutyl carbitotol residue; triethylene glycol monomethyl Ether, -monoethyl ether, -monobutyl ether residue; glycerin 1,2-dimethyl ether, -1,3-diethyl ether, -1-ethyl-2-propyl ether residue; nonylphenoxy polyethoxyethyl, lauroxy Examples include polyethoxyethyl residues. Furthermore, among the metals, zinc, calcium and barium are particularly preferred. The organic phosphate metal salts having various substituents as described above can be blended singly or in combination of two or more. In the agricultural film of the present invention, it is most preferable to use an organic phosphate ester and an organic phosphate metal salt in combination in terms of film formation properties and outdoor spreadability. The amount of organic phosphate ester or organic phosphate metal salt is 0.1 parts by weight per 100 parts by weight of vinyl chloride resin.
-15 parts by weight, preferably 0.2-10 parts by weight. If the amount is less than 0.1 part by weight, the weather resistance and dust resistance of the soft vinyl chloride resin film will not improve. If the amount is more than 15 parts by weight, the transparency of the film will be extremely poor, which is not preferable. Within the above range, a range of 0.2 to 8 parts by weight is particularly preferred. In addition to the above-mentioned plasticizer, organic phosphate ester, or organic phosphate metal salt, the vinyl chloride resin may optionally contain known resin additives that are usually blended into synthetic resins for molding, such as , lubricant, thermal stability, ultraviolet absorber, light stabilizer, antioxidant,
Stabilizing aids, antistatic agents, antifogging agents, antifungal agents, antialgal agents, inorganic fillers, colorants, and the like can be blended. Examples of lubricants, heat stabilizers, and antioxidants that can be incorporated into the film of the present invention include polyethylene waxes, bisamide compounds, liquid paraffin, organic phosphorite compounds, and β-diketone compounds. The above various resin additives can be used alone or in combination. The amount of the various resin additives mentioned above can be selected within a range that does not deteriorate the properties of the film, usually within a range of 10 parts by weight or less based on 100 parts by weight of the base vinyl chloride resin. In order to blend the plasticizer, organic phosphate ester or organic phosphate metal salt, and other resin additives into the vinyl chloride resin that serves as the base of the film, the necessary amounts of each are weighed out, and then mixed with a ribbon blender, a Banbury mixer, A spar mixer or other conventionally known compounding machine or mixing machine may be used. In order to form a film from the resin composition obtained in this way, a method known per se can be used, such as melt extrusion molding method (including T-die method and inflation method), calender molding method, solution casting method. etc. The agricultural vinyl chloride resin film of the present invention is
A film of a composition containing a silane compound, a specific acrylic resin, and a crosslinkable compound that crosslinks both as main components is formed on one or both sides of the film under heat treatment. The silane compound [A] used in the present invention has a hydrolyzable group directly bonded to a silicon atom. Specifically, aminomethyltriethoxysilane, N-β-aminoethylaminomethyltrimethoxysilane, γ-aminopropyltrimethoxysilane, N-(trimethoxysilylpropyl)-ethylediamine, N-(dimethoxymethylsilylpropyl) - Aminoalkylalkoxysilane such as ethylenediamine; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-
Epoxyalkylalkoxysilanes such as (3,4-epoxychlorohexyl)ethylmethyldimethoxysilane; Mercaptoalkylalkoxysilanes such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane; Tetramethoxysilane, tetraethoxysilane, tetra Tetraalkoxysilane such as butoxysilane, trimethoxyneopentoxysilane, dimethoxydineopentoxysilane; Alkyltrialkoxysilane such as methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane; dimethyldimethoxy Dialkyldialkoxysilanes such as silane and dimethyldiethoxysilane; halogenated alkylalkoxysilanes such as γ-chloropropyltrimethoxysilane and 3,3,3-trichloropropyltrimethoxysilane; methyltriacetoxysilane, dimethyldiacetoxysilane, etc. alkyl acyloxysilane; hydrosilane compounds such as trimethoxysilane and triethoxysilane; vinyltrimethoxysilane, vinylethoxysilane,
vinyltris(β-methoxyethoxy)silane,
Allyltriethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)
Acryloxypropyltriethoxysilane, γ-
Examples include monomers or polymers of unsaturated group-containing silane compounds such as (meth)acryloxypropylmethyldimethoxysilane, and hydrolysates thereof. 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, partial hydrolysis occurs depending on the ratio. something is prepared. Among these silane compounds, in particular, the general formula (R ⁴ O) ₃ Si[OSi(OR ⁵ ) ₂ ] _o (OR ⁶ ) (wherein R ⁴ to R ⁶ are each the same or different alkyl group, aryl a monomer or polymer of tetraalkoxysilane represented by the group alkylaryl group, arylalkyl group, aryloxyalkyl group, or alkyloxyalkyl group, and n represents 0 or a positive integer, and further hydrated Compounds obtained by hydrolyzing a degradable group are preferred. Among these, compounds in which R ⁴ to ^{R 6} are the same or different alkyl groups having 4 or less carbon atoms are particularly preferred. These silane compounds may be used alone or in combination of two or more. The acrylic resin [B] in the present invention refers to a monomer of alkyl esters of acrylic acid or methacrylic acid (hereinafter referred to as (meth)acrylic acid alkyl esters) alone or in combination with an alkenylbenzene monomer. It is obtained by polymerizing a mixture with a copolymerizable α,β-ethylenically unsaturated monomer under conventional polymerization conditions. Examples of the (meth)acrylic acid alkyl esters used in the present invention include acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid n-propyl ester, acrylic acid isopropyl ester, acrylic acid n-butyl ester, and acrylic acid methyl ester. -2-ethylhexyl ester,
Examples include decyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, and decyl methacrylate. 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 the alkenylbenzenes to be mixed with the (meth)acrylic acid alkyl esters include styrene, α-methylstyrene, and vinyltoluene. When using a monomer mixture of such alkenylbenzenes and (meth)acrylic acid alkyl esters, the usage ratio is as follows:
Although it varies depending on the amount of the α,β-ethylenically unsaturated monomer used, it is usually preferable that the proportion of the (meth)acrylic acid alkyl ester used is 10% by weight or more. Other copolymerizable α,β-ethylenically unsaturated monomers used to obtain the acrylic resin [B] include, for example, acrylic acid, methacrylic acid,
α, β-ethylenically unsaturated carboxylic acids such as maleic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid; α, β-ethylenically unsaturated carboxylic acids such as ethylene sulfonic acid,
β-ethylenically unsaturated sulfonic acids; 2-acrylamido-2-methylpropanoic acid; α,β-ethylenically unsaturated phosphonic acids; acrylonitriles; acrylamides; containing hydroxyl groups such as hydroxyalkyl esters of acrylic acid or methacrylic acid Vinyl monomers; amino esters of acrylic acid or methacrylic acid; glycidyl esters of acrylic acid or methacrylic acid; acrylic acid or methacrylates, and the like. These monomers may be used alone or in combination of two or more. Examples of the polymerization initiator used in the production of the acrylic resin [B] include persulfates such as ammonium persulfate and potassium persulfate; organic peroxides such as acetyl peroxide and benzoyl peroxide. These are used in an amount of 0.1 to 10% by weight based on the total amount of monomers charged. Acrylic resin can be produced using bulk polymerization method, solution polymerization method,
It can be produced by any polymerization method such as suspension polymerization or emulsion polymerization. The obtained acrylic resin can be further added with a compound such as vinyl chloride/vinyl acetate resin, vinyl chloride resin, cellulose ether, etc. The crosslinkable compound [C] used in the present invention is a compound capable of crosslinking a hydrolyzable group such as a silanol group or an alkoxy group or an acrylic resin in the silane compound [A], such as isocyanate, carboxyl, etc. Examples include compounds such as epoxy-based, epoxy-based, alkyl ether-based, amine-based, aziridine-based, phenolic resin, and amino resin. Among these, it is particularly suitable to use isocyanate compounds. The blending ratio of the silane compound [A] and the acrylic resin [B] is 20:1 by weight.
Preferably, the ratio is between 1 and 15. When the proportion of the silane compound [A] is above the above range,
Even if the crosslinking compound [C] is added, the coating formed on the film will be brittle, have poor adhesion to the base material, and will be easily peeled off, and if the proportion of the acrylic resin [B] exceeds the above range. If this is the case, the effect of stain resistance will be markedly difficult to develop. especially,
The weight ratio of [A] to [B] is preferably in the range of 15:1 to 1:10. The amount of the crosslinking compound [C] to be blended is preferably such that the weight ratio of [A] to [C] per organic component to the silane compound [A] is in the range of 100:0.1 to 100:50. When the proportion of the crosslinkable compound [C] is above the above range, the pot life of the coating solution decreases, while
The coating formed on the film becomes brittle and easily peels off. Furthermore, if the proportion of the crosslinkable compound [C] is below the above range, it will be difficult to exhibit sufficient dust-proofing effects. In particular, [A] vs. [C]
Preferably, the ratio is in the range of 100:1 to 100:30. A liquid dispersion medium may be added to the coating composition as necessary. Such liquid dispersion media include monohydric alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; polyhydric alcohols such as ethylene glycol, diethylene glycol, and glycerin; cyclic alcohols such as dibenzyl alcohol; and cellosolve acetates. ; Examples include ketones. These liquid dispersion media are
Although they may be used alone or in combination, they are preferably determined by taking into consideration the dispersion stability of the coating composition, the wettability after coating on the film surface, the difficulty of removing the liquid dispersion medium, and economic efficiency. The above composition may also contain small amounts of acid or alkaline antifoaming agents, surfactants, lubricants, antistatic agents, plasticizers, antioxidants, ultraviolet absorbers, light stabilizers, film forming aids, and thickeners. , a fungicide, an algaecide, a pigment, a pigment dispersant, an inorganic filler, and other conventional additives may be mixed. . Various known methods can be applied to form a film on the surface of the soft vinyl chloride resin film by applying the film composition. For example, when forming a film in a liquid state, doctor blade coating method, gravure roll coating method, air knife coating method, reverse roll coating method, dip coating method, brush coating method, spray coating method, bar coating method, knife coating method Any method known per se may be used. Alternatively, a coextrusion method, an extrusion coating method, an extrusion lamination method, or a lamination method of the above-mentioned coating composition may be employed instead of forming it in a solution state. A film derived from the film composition is formed on the surface of a soft vinyl chloride resin film under heat treatment. Through heat treatment, the silane compound, acrylic resin, and crosslinking compound are chemically bonded, resulting in a strong film with excellent barrier properties against weathering deterioration factors and pollutants, improving weather resistance and dust resistance. do. Heat treatment methods when using a coating method as a coating method include, for example, hot air heating, infrared heating, far infrared heating, etc. However, in consideration of heat treatment efficiency and safety, hot air heating is advantageous. The temperature condition in this case is 50-200
℃ range, and the time should be selected between 10 seconds and 60 minutes. The adhesion amount of the film formed on the surface of the soft vinyl chloride resin film during heat treatment is 0.1 to 10.
It is preferable to set it as the range of g/m ^<2> . 0.1g/ ^m2
If the amount is less, the effect of preventing the plasticizer from migrating to the surface of the soft vinyl chloride resin film will be insufficient. On the other hand, if it is 10 g/m ² or more, the amount of coating is too large, resulting in an economical disadvantage and a decrease in the mechanical strength of the film itself. Therefore, a range of 0.5 g/m ² to 7 g/m ² is usually most preferred. In addition, before coating with the 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 plasma. may be pretreated. When actually using the agricultural vinyl chloride resin film of the present invention as an agricultural covering material,
When the coating is formed on only one side, use the side with the coating on the outside of the house or tunnel. "Function" The agricultural vinyl chloride resin film according to the present invention has a coating formed on its surface that prevents the various resin additives blended into the film from seeping out, so the film can be used outdoors for long periods of time. Also, there is less surface contamination and less decrease in light transmittance. This coating also has excellent flexibility and adhesion. Furthermore, since the base film contains an organic phosphate ester or an organic phosphate metal salt, it has a high elongation retention rate and excellent durability. "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 Preparation of base film Polyvinyl chloride (=1400) 100 parts by weight Dioctyl phthalate 50 〃 Epicoat 828 (epoxy compound, trade name manufactured by Shell Company, USA) 1 〃 Ba/Zn-based composite stable A resin composition consisting of 1.5 〃 barium stearate (stabilizer) 0.2 〃 zinc stearate 0.4 〃 sorbitan monolaurate 1.5 〃 was prepared, and the organic phosphate ester or organic phosphoric acid of the type and amount shown in Table 1 was prepared. Contains metal salts. However, in Comparative Examples 1, 2, and 3, 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 Production Examples 1 to 4 Into a reactor equipped with a thermometer, a stirrer, a reflux condenser, and a nozzle for adding raw materials, 100 parts by weight of isopropyl alcohol, 1.0 parts by weight of benzoyl peroxide, and the ingredients shown in Table 2 were added. 100 parts by weight of each monomer mixture was charged, and while stirring in a nitrogen gas stream, it was heated at 80°C for 3 hours. Furthermore, 0.5 parts by weight of benzoyl peroxide was added, and the reaction was continued at the same temperature for about 3 hours. Four types of resins A to D were obtained. Formation of a film A silane compound, an acrylic resin, and a crosslinking compound of the types and amounts shown in Table 1 were blended, and isopropyl alcohol was added thereto so that the solid content was 20% by weight to obtain a film composition. . However, in Comparative Example 1, no silane compound was added, in Comparative Example 2, no acrylic resin was added, and in Comparative Example 3, no crosslinkable compound was added. Each of these compositions was applied to one side of the base film using a #5 bar coater. The coated film was kept in an oven at 130° C. for 3 minutes to volatilize the material and at the same time perform heat treatment. However, in Comparative Example 6, after coating the coated molded product, the solvent was volatilized by natural drying without heat treatment. The coating weight of each film obtained was approximately 2 g/m ² . Evaluation of the film The performance of the film was evaluated using the following methods.
The results are shown in Table 1. Crosslinking property of coating After drying the coating composition on release paper, about 2 g/
m ² and heated in an atmosphere of 130° C. for 3 minutes to volatilize the solvent. The film was scraped off, immersed in isopropyl alcohol (IPA) solvent, and left in a constant temperature water bath maintained at 35°C for 1 hour. After separating the IPA solvent, it was vacuum dried for 24 hours and its weight was measured. This weight ratio (weight after immersion drying/initial weight x
The larger the value of 100), the more cross-linked the film is. Film flexibility Cut each film into 5cm wide and 15cm long pieces.
It was folded back alternately at 2 cm intervals in the direction perpendicular to the length direction. In this state, a load of 2 kg was applied from above and the sample was left in a constant temperature bath maintained at 15° C. for 24 hours. Then, the load was removed, the folds of the film were stretched out, and the appearance of the film was observed with the naked eye. The results are shown in Table 1. The evaluation criteria for this test are as follows. ◎…No change is observed in the film at the crease. △...Cracks are observed in the coating at the creases. ×: Cracks are significantly observed in the coating at the creases. Outdoor expansion test Twelve types of films were placed in a roof-type greenhouse (width 3m, depth 5m, ridge height 1.5m, roof slope 30 degrees) installed in a test field in Ichishi District, Mie Prefecture, with the coated side facing outside the greenhouse. Covered in 1986
Expansion tests were conducted for two years from August 1980 to July 1988. The stretched film was tested for its appearance and the elongation retention rate was measured using the following method.
Dust resistance was evaluated. () Appearance of the film: Appearance observed with the naked eye. The evaluation criteria are as follows. ◎…No change in appearance such as discoloration is observed. ○…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. () Film elongation retention rate...means the value calculated using the following formula. Elongation of the film after outdoor expansion/Elongation of the film before outdoor expansion x 100 (%) () Dust resistance...Means the value calculated using the following formula. Light transmittance of film collected over time after outdoor expansion/Light transmittance of film before outdoor expansion _*
×100 (%) *Direct light transmission at wavelength 555 mμ (manufactured by Hitachi, EPS-2U model used) Measurement results were displayed as follows. ◎...Light transmittance after expansion is 90% or more of that before expansion. ○…Light transmittance after expansion is 70-89% of before expansion
Those in the range of. △…Light transmittance after expansion is 50-69% of before expansion
Those in the range of. ×...Those whose light transmittance after expansion is less than 50% of that before expansion.

【table】

【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 agricultural utility value. (1) Even when the agricultural vinyl chloride resin film according to the present invention is stretched outdoors for a long period of time, there is little discoloration, a decrease in physical properties, and a decrease in dust resistance, and it can be used for a long period of time. (2) In the agricultural vinyl chloride resin film according to the present invention, the coating formed on the surface of the base film has excellent adhesion to the base film and is highly flexible, so the coating is difficult to peel off. Withstands long-term use.

Claims (1)

[Scope of Claims] 1. On one or both sides of a soft vinyl chloride resin film containing an organic phosphate ester or an organic phosphate metal salt, [A] a silane compound having a hydrolyzable group directly bonded to a silicon atom, [ B] Polymerization of a monomer selected from alkyl esters of acrylic acid or methacrylic acid, or a mixture of this and an alkenylbenzene monomer, and a copolymerizable α,β-ethylenically unsaturated monomer. 1. An agricultural vinyl chloride resin film formed by heat treatment to form a film of a composition containing three components as main components: an acrylic resin obtained by the above-mentioned method and a crosslinkable compound (C). 2 The silane compound [A] has the general formula (R ⁴ O) ₃ Si[OSi(OR ⁵ ) ₂ ] _o (OR ⁶ ) (wherein R ⁴ to R ⁶ are each the same or different alkyl group, aryl group, alkylaryl group, arylalkyl group, aryloxyalkyl group, or alkyloxyalkyl group, and n represents 0 or a positive integer); The agricultural vinyl chloride resin film according to claim 1, wherein is a compound obtained by hydrolyzing a hydrolyzable group. 3. The agricultural vinyl chloride resin film according to claim 1 or 2, wherein the crosslinkable compound [C] is an isocyanate compound.