JPH11254605A - Agricultural vinyl chloride-based resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a film, the external appearance before setting up of which is favorable and which is excellent in an impact resistance, a blocking resistance and the like by a method wherein an acrylic resin film, which is formed on the side of a vinyl chloride-based resin film and has the predetermined thickness, includes the specified mixture resin represented by a formula under the specified conditions and the content of the specified elastic body is set to be the specified value. SOLUTION: An acrylic resin film, which is formed on one side or both the sides of a vinyl chloride-based resin film and has the thickness of 1-10 μm, has a graft copolymer having a crosslinked alkyl(meth)acrylate-based elastic body as its body, which is obtained from an alkyl acrylate monomer, an alkyl methacrylate monomer represented by the formula I or their mixture or an alkyl(meth)acrylate monomer as a main ingredient and a vinyl-based monomer copolymerizable with the main ingredient in the presence of crosslinked alkyl acrylate-based or crosslinked alkyl methacrylate-based elastic body particles under the condition that the percentage of the crosslinked alkyl(meth)acrylate-based elastic body in a resin is set to be 5-80 wt.%. In the formula, R1 represents a hydrogen atom or a methyl group and (n) is an integer from 1 through 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin film for agricultural use. More specifically, durability is improved against undesired deterioration phenomena such as discoloration, embrittlement, reduction in dust resistance, and reduction in adhesion between the coating and the vinyl chloride resin film, which are caused as a result of stretching outdoors. And a vinyl chloride resin film for agricultural use.

[0002]

2. Description of the Related Art In recent years, farmers who cultivate useful plants often use useful plants in greenhouses to improve profitability.
Or, the method of promoting cultivation or suppression cultivation in a tunnel has been widely adopted. As a material for covering the house or the tunnel, a polyethylene film, an ethylene-vinyl acetate copolymer film, a polyester film, a polycarbonate film, a hard and soft vinyl chloride resin film, glass and the like are used. Among them, 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. .

However, a synthetic resin film used as a covering material for a house or a tunnel, including a vinyl chloride resin film, has been used as a covering material for more than one year, and has been used for a year after passing through sunlight, especially ultraviolet rays. And changes over time such as deterioration of appearance and decrease in flexibility of the film. Furthermore, recently improved agricultural techniques, especially those aiming at economy and labor saving, require the covering materials to be more resistant to severe conditions than ever before. Therefore, for example, a technique of adding and mixing an organic phosphate or a metal organic phosphate to a vinyl chloride resin as a base material for the purpose of improving weather resistance and forming a film has been widely adopted.

[0004] On the other hand, vinyl chloride resin films used for agriculture may be dust-proofed on the outer surface of the house or tunnel after two years have elapsed from the start of use, depending on the area or place where they are used. The properties are remarkably reduced, and the product cannot be used. As a solution to these disadvantages,
As described in the following (I) and (II), there has been proposed a method of forming a film on the surface of a vinyl chloride resin film for agricultural use with a specific resin or paint. (I) A method of applying a specific acrylic resin (Japanese Patent Publication Sho 46
(JP-A-29639, JP-B-50-28117, etc.) (II) Method of coating ultra-high molecular weight acrylic resin (JP-B-63-9987) However, the specific acrylic resin described in (I) The coating made of the composition is not enough to prevent the compounding agent such as the plasticizer in the base material from bleeding out (bleed out) to the surface of the vinyl chloride resin film, and has a poor dustproof property.
The method I) has a disadvantage that the coatability of the film is poor.

[0005] Further, when the above-mentioned vinyl chloride resin film is spread on a house or a tunnel, the film depends on the method of spreading, the structure of the house or the tunnel, the place and direction where these are installed, and the weather conditions at the time of spreading. May be bent or blown by the wind. In such a case,
If the stretchability and impact resistance of the film formed on the surface of the vinyl chloride resin film are inferior, cracks may occur inside the film (cracks), and numerous fine cracks may occur on the surface (crazing). As a result, the coating peels off or causes an apparent whitening of the film, causing a practical problem. In order to improve the impact resistance of a coating made of an acrylic resin, the proportion of a component that improves the flexibility of the acrylic resin such as an acrylate ester is increased, and the glass transition temperature of the acrylic resin (hereinafter, referred to as the
It has been experimentally found that it is necessary to lower the "Tg"). However, if the Tg is too low, a problem (blocking) occurs in which the films cannot be easily peeled off when the films are stacked, and the impact resistance and the blocking resistance are deteriorated. It was difficult to balance.

[0006]

Under such circumstances, the present inventors have found that even under severe conditions at the time of spreading, whitening or peeling of the coating does not occur, and the appearance before house expansion is good. To provide a vinyl chloride resin film for agricultural use which does not cause a decrease in adhesion between the film and the vinyl chloride resin film caused by stretching outdoors and has excellent properties such as impact resistance, blocking resistance, and durability. As a result of intensive studies for the purpose of the present invention, the present invention has been completed.

[0007]

The gist of the present invention resides in that a vinyl chloride resin film containing an organic phosphate or an organic metal phosphate is coated on one or both sides with a thickness of 1 to 10 μm. (A) the acrylic resin is formed of crosslinked alkyl acrylate-based elastic particles or crosslinked alkyl methacrylate-based elastic particles (hereinafter referred to as “crosslinked alkyl (meth) acrylate-based elastic An alkyl acrylate monomer represented by the following structural formula (1), an alkyl methacrylate monomer or a mixture thereof (hereinafter, collectively referred to as an “alkyl (meth) acrylate monomer”); Alkyl (meth) acrylate monomer as the main component, vinyl type copolymerizable with it It contains a graft copolymer based on a crosslinked alkyl (meth) acrylate-based elastomer obtained by polymerizing a mixture with a nomer, and contains a crosslinked alkyl (meth) acrylate-based elastomer in a (b) acrylic resin. The agricultural polyvinyl chloride resin film, characterized in that the ratio of the body is 5 to 80% by weight, wherein the vinyl chloride resin film further contains an ultraviolet absorber. The film and the vinyl chloride resin film are in the above-mentioned agricultural vinyl chloride resin film comprising a light stabilizer.

[0008]

Embedded image (R ₁ in the structural formula represents hydrogen or a methyl group, and n represents 1 to 1
Each means an integer of 2)

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. 1. Vinyl chloride resin film In the present invention, the vinyl chloride resin refers to not only a homopolymer of vinyl chloride, but also a copolymer of vinyl chloride having vinyl chloride as a main component and other monomers, and a mixture thereof. Say. Examples of monomers copolymerizable with vinyl chloride include vinylidene chloride, ethylene, propylene, acrylonitrile, maleic acid, itaconic acid, acrylic acid, methacrylic acid, and vinyl acetate. The vinyl chloride resin may be produced by any of conventionally known production methods such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, and a bulk polymerization method.

Further, in the present invention, an organic phosphate or an organic metal phosphate is compounded in the vinyl chloride resin film. Examples of the organic phosphoric acid ester include triisopropylphenyl phosphate, isodecyldiphenyl phosphate, tris (isopropylphenyl) phosphate, tributylphosphate, triethylphosphate, trioctylphosphate, tributoxyethylphosphate, triphenylphosphate, octyldiphenylphosphate, and trixylenyl. Phosphate and the like can be mentioned, and among them, tricresyl phosphate and trixylenyl phosphate are particularly preferable. The above organic phosphates can be used alone or in the form of a composite, and examples thereof include a composite of an organic phosphate and an organic phosphite. As organic metal phosphates,
Examples include those represented by the following structural formulas (2) and (3).

[0011]

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[0012]

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(In the structural formula, M represents zinc, calcium, barium, magnesium, cobalt or strontium. Further, R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each an alkyl, aryl, aralkyl, Examples of the alkyl group for R ₂ , R ₃ , R ₄ , R ₅ and R ₆ include methyl, ethyl, and normal (hereinafter, “n”).
-)) Propyl, iso (hereinafter referred to as "i-")
Propyl, n-butyl, i-butyl, sec-butyl, tertiary
Butyl, amine, neopentyl, i-amyl, n-hexyl, i-hexyl, heptyl, n-octyl, i-octyl, 2-ethylhexyl, n-decyl, i-decyl, lauryl, tridecyl, having 12 to 12 carbon atoms And mixed alkyl of 13 alkyls, stearyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, 4-methylcyclohexyl and the like.

Examples of the aryl group include phenyl and naphthyl groups. Examples of the aralkyl group include a benzyl, β-phenylethyl, α-phenylpropyl, β-phenylpropyl group and the like. Examples of alkylaryl groups include tolyl, xylyl, ethylphenyl, butylphenyl, tertiary butylphenyl, n-octylphenyl, i-octylphenyl,
Tertiary octylphenyl, nonylphenyl, 2,4-di-
And a tertiary butylphenyl group. Examples of the alkyl group having an ether bond include furfuryl, tetrahydrofurfuryl, 5-methylfurfuryl and α-methylfurfuryl group or methyl cellosolve group, ethyl cellosolve, i-propyl cellosolve, n-butyl cellosolve,
i-butyl cellosolve, hexyl cellosolve, cyclohexyl cellosolve, phenyl cellosolve residue; methyl carbitol, ethyl carbitol, i-propyl carbitol, butyl carbitol, i-butyl carbitol residue; triethylene glycol monomethyl ether, triethylene glycol Monoethyl ether, triethylene glycol monobutyl ether residue; glycerin monomethyl ether, glycerin monoethyl ether, glycerin monobutyl ether residue; glycerin 1,2-dimethyl ether, glycerin 1,3-diethyl ether, glycerin 1-ethyl-2-propyl Ether residues; nonylphenoxypolyethoxyethyl, lauroxypolyethoxyethyl residues and the like.

As the metal represented by M in the structural formula, zinc, calcium and barium are particularly preferred. One or more of these organic phosphates or metal organic phosphates can be blended, and in particular, a combination of an organic phosphate and an organic metal phosphate is a vinyl chloride resin film. It is preferable because the weather resistance including prevention of deterioration of the physical properties is improved. The amount of the organic phosphoric acid ester or the organic phosphoric acid metal salt can be adjusted according to the vinyl chloride resin 10
It is preferably 0.1 to 15 parts by weight, more preferably 0.2 to 10 parts by weight, particularly preferably 0.2 to 0 parts by weight.
８8 parts by weight. If the amount is less than 0.1 part by weight, the weather resistance of the vinyl chloride resin film may be poor. If the amount is more than 15 parts by weight, the transparency of the film tends to be poor.

The vinyl chloride resin film may be blended with, for example, 20 to 60 parts by weight of a plasticizer based on 100 parts by weight of the vinyl chloride resin in order to impart flexibility. By blending the plasticizer in the above range, it is possible to impart excellent flexibility and mechanical properties to the vinyl chloride resin film. Examples of the plasticizer include phthalic acid derivatives such as di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate and di-i-decyl phthalate; isophthalic acid derivatives such as dioctyl phthalate; di-n-butyl Adipic acid derivatives such as adipate and dioctyl adipate;
maleic acid derivatives such as n-butylmalate; tri-n-
Citric acid derivatives such as butyl citrate; itaconic acid derivatives such as monobutyl itaconate; oleic acid derivatives such as butyl oleate; ricinoleic acid derivatives such as glycerin monoricinoleate; other epoxidized soybean oil; epoxy resin plasticizer And the like.

The compound to be added to impart flexibility to the vinyl chloride resin film is not limited to the above-mentioned plasticizers. For example, thermoplastic polyurethane resin,
Polyvinyl acetate or the like can also be used. In addition, it is preferable to add an ultraviolet absorber or a light stabilizer to the vinyl chloride resin film. In particular, the combined use of an ultraviolet absorber and a light stabilizer can improve the weather resistance of the vinyl chloride resin film, which is preferable. The ultraviolet absorber may be any one that is usually blended in a vinyl chloride resin film for agricultural use, and includes various ultraviolet absorbers such as benzophenone, benzotriazole, salicylate, hydroquinone, and cyanoacrylate. . In particular, benzophenone-based and benzotriazole-based ultraviolet absorbers are preferred, and specific examples include the following.

Benzophenone type 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-benzoyloxybenzophenone,
2'-dihydroxy-4-methoxybenzophenone, 2
-Hydroxy-4-methoxy-5-sulfobenzophenone, 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-butyl ester benzotriazole,
2- (2'-hydroxy-5'-methylphenyl)-
5,6-dichlorobenzotriazole, 2- (2'-hydroxy-5'-methylphenyl) -5-ethylsulfobenzotriazole, 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-phenyl) benzotriazole ethyl ester, 2- (2'-
Hydroxy-3 ′, 5′-di-tert-butylphenyl)-
5-chlorobenzotriazole, 2- (2'-hydroxy-3'-methyl-5'-t-butylphenyl) -5
Chlorobenzotriazole, 2- (2'-hydroxy-
3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5 '
-Methoxyphenyl) benzotriazole, 2- (2 '
-Hydroxy-3 ', 5'-di-t-butylphenyl)
-5-chlorobenzotriazole, 2- (2'-hydroxy-5'-cyclohexylphenyl) benzotriazole, 2- (2'-hydroxy-4 ', 5'-dimethylphenyl) -5-benzotriazole, 2- ( 2′-hydroxy-4 ′, 5′-dichlorophenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-dimethylphenyl) -5-ethylsulfobenzotriazole, 2- (2′-hydroxy-4) 'Octoxyphenyl) benzotriazole, 2- (2'-hydroxy-
5'-methoxyphenyl) -5-methylbenzotriazole, 2- (2'-hydroxy-5'-methylphenyl) -5-esterbenzotriazole, 2- (2'-
(Acetoxy-methylphenyl) benzotriazole.

The amount of the ultraviolet absorber is preferably 0.02 to 8 parts by weight based on 100 parts by weight of the vinyl chloride resin. If the amount is less than 0.02 parts by weight, the weather resistance of the agricultural vinyl chloride resin film may not be sufficiently high, which is not preferable. On the other hand, when the blending amount is more than 8 parts by weight, there is a possibility that a problem may occur in that the film is ejected to the film surface together with other additives when the film is used. Of the above compounding amounts, 0.
1-3 parts by weight are particularly preferred. As the light stabilizer, a hindered amine compound containing at least one structural unit represented by the following structural formula (4) in one molecule is preferable.

[0021]

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(In the formula (4), R ₇ , R ₈ , R ₉ and R ₁₀ represent an alkyl group having 1 to 4 carbon atoms, and R ₁₁ represents hydrogen or an alkyl group having 1 to 4 carbon atoms.) A typical example of such a hindered amine compound is shown in the following structural formula (5).

[0023]

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(Wherein R is a monoacyl, diacyl, triacyl or tetraacyl group derived from phosphorus or a mono- to tetravalent carboxylic acid, R ₇ , R ₈ , R ₉ and R
₁₀ is an alkyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 4 respectively. Specific examples of those contained in the above structural formula (5) include, for example, 4-cyclohexanoyloxy-2,2,6,6
-Tetramethylpiperidine, 4-benzoyloxy-
2,2,6,6-tetramethylpiperidine, 4- (o-
(Chlorobenzoyloxy) -2,2,6,6-tetramethylpiperidine and the like. The amount of light stabilizer
0.2 to 1.0 based on 100 parts by weight of vinyl chloride resin
It is preferably in parts by weight. If the compounding amount is less than 0.2 parts by weight, the weather resistance of the film may not be sufficiently excellent, so that it is not preferable. The properties are not improved, and there is a risk of spouting on the film surface.

In addition, vinyl chloride resin films include:
If necessary, known resin additives usually blended in a vinyl chloride resin film, for example, a lubricant, a heat stabilizer, an antioxidant, a stabilizing aid, an antistatic agent, an antifogging agent, a fungicide,
An anti-algal agent, an inorganic filler, a coloring agent, and the like can be added. Examples of the lubricant include a polyethylene wax, a bisamide compound, and liquid paraffin. Examples of the heat stabilizer include a β-diketone compound, and examples of the antioxidant include an organic phosphite compound. These various resin additives can be used alone or in combination of two or more. The addition amount of the various resin additives can be selected within a range that does not impair the object and effect of the present invention, and usually within a range of 10 parts by weight or less based on 100 parts by weight of the vinyl chloride resin.

In order to compound an organic phosphate or a metal salt of an organic phosphate, a plasticizer, an ultraviolet absorber, a light stabilizer, and other additives for a resin with the vinyl chloride resin, the respective necessary amounts are as follows: What is necessary is just to mix and knead using a ribbon blender, a Banbury mixer, a super mixer and other conventionally known compounding machines and mixers. To make the vinyl chloride resin composition thus obtained into a film,
For example, a method which can be usually used for a vinyl chloride film formation, such as a melt extrusion molding method (including a T-die method and an inflation method), a calendar molding method, and a solution casting method may be used.

The thickness of the vinyl chloride resin film used in the present invention is usually from 10 to 300 μm. 2. Acrylic resin coating 2-1. Acrylic Resin The acrylic resin used in the present invention comprises, in the presence of (a) crosslinked alkyl (meth) acrylate-based elastic particles, an alkyl (meth) acrylate monomer represented by the following structural formula (1) or an alkyl (meth) acrylate: Contains a graft copolymer having a crosslinked alkyl (meth) acrylate elastomer as a main component, obtained by polymerizing a mixture of a meth) acrylate monomer as a main component and a copolymerizable vinyl monomer. The ratio of the crosslinked alkyl (meth) acrylate-based elastic material in the (b) acrylic resin is from 5 to 80.
It is a resin which is weight%.

[0028]

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(R ₁ in the structural formula represents hydrogen or a methyl group, and n represents an integer of 1 to 12) 2-1-1. Crosslinked alkyl (meth) acrylate-based elastic body The crosslinked alkyl (meth) acrylate-based elastic body is preferably produced by an emulsion polymerization method. As a method for producing a crosslinked alkyl (meth) acrylate-based elastic material by an emulsion polymerization method, the following method is exemplified. (1) A method in which a small amount of a crosslinkable monomer is added to an alkyl (meth) acrylate monomer or a mixture of an alkyl (meth) acrylate monomer and a copolymerizable vinyl monomer, and the mixture is produced by an emulsion polymerization method. (2) An alkyl (meth) acrylate monomer or a mixture of an alkyl (meth) acrylate monomer and a vinyl monomer copolymerizable therewith is further added to the polymer emulsion obtained by the method of (1), followed by an emulsion polymerization method. How to manufacture by. (3) In the method of (2), a small amount of a crosslinkable monomer is added to an alkyl (meth) acrylate monomer or a mixture of an alkyl (meth) acrylate monomer and a vinyl monomer copolymerizable with the alkyl (meth) acrylate monomer. How to make.

(4) First, an uncrosslinked polymer is produced from an alkyl (meth) acrylate monomer or a mixture of an alkyl (meth) acrylate monomer and a vinyl monomer copolymerizable therewith by an emulsion polymerization method. Next, an alkyl (meth) acrylate monomer, or a mixture of an alkyl (meth) acrylate monomer and a copolymerizable vinyl monomer, and a small amount of a crosslinkable monomer are added to the polymer, and the mixture is subjected to emulsion polymerization. How to make. (5) To one of the polymer emulsions obtained by the methods (1) to (4), an alkyl (meth) acrylate monomer or a vinyl monomer copolymerizable therewith is added, A method of producing by an emulsion polymerization method without or with the addition of a small amount of a crosslinking monomer. As the alkyl (meth) acrylate monomer, those having 1 to 12 carbon atoms in the alkyl group are preferable, and may be linear or branched. Examples of such a material include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2- (meth) acrylate.
Ethylhexyl (meth) acrylate, decyl (meth)
Alkyl (meth) acrylates such as acrylates are exemplified. These may be used alone or in combination of two or more.

Examples of vinyl monomers copolymerizable with these alkyl (meth) acrylate monomers include acrylic acid, methacrylic acid, alkyl esters of acrylic acid (where the alkyl group has 1 to 12 carbon atoms), and alkyl monomers of methacrylic acid. Ester (alkyl group having 1 to 1 carbon atoms)
12), dialkyl esters of itaconic acid (the alkyl group has 1 to 10 carbon atoms), acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, styrene, each alkyl-substituted styrene, α-methylstyrene and the like. These comonomers may be up to 40% by weight,
Preferably, the content is 25% by weight or less. The polymerization initiator used in this emulsion polymerization is a usual free radical generating initiator. Specific examples include inorganic peroxides such as potassium persulfate and ammonium persulfate; cumene hydroperoxide, p-menthane hydroperoxide,
Organic hydroperoxides such as ditertiary butyl hydroperoxide; benzoyl peroxide;
Examples include organic peroxides such as lauroyl peroxide and cumene peroxide, and azo-based initiators such as azobisisobutyronitrile.

Further, ordinary redox initiators obtained by combining these with reducing agents such as sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, glucose, polyamine, and hydroxyacetone ascorbic acid can also be used. Examples of the emulsifier include a surfactant for usual emulsion polymerization. For example, sodium, potassium, ammonium salts and lauric acid of alkyl sulfate having 8 to 20 carbon atoms,
Anionic surfactants such as sodium and potassium salts of aliphatic carboxylic acids such as stearic acid and palmitic acid, and nonionic surfactants such as reaction products of alkylphenols, aliphatic alcohols and polypropylene oxides with ethylene oxide Agents. In some cases, two or more of these surfactants can be used in combination. Further, a surfactant such as a naphthalene formaldehyde condensed sulfonic acid salt may be added. Further, if necessary, a cationic surfactant such as alkylamine hydrochloride can be used.

The crosslinking monomer used in the emulsion polymerization may be any one which is usually used as a polyfunctional compound. Specific examples thereof include ethylene glycol dimethacrylate and 1,3-butylene glycol dimethacrylate. Alkyl methacrylates such as 1,4-butylene glycol dimethacrylate, propylene glycol dimethacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, dipropylene glycol dimethacrylate, allyl methacrylate; ethylene glycol diacrylate;
1,3-butylene glycol diacrylate, 1,4-
Alkyl acrylates such as butylene glycol diacrylate, propylene glycol diacrylate, trimethylolpropane triacrylate, tetramethylol methane tetraacrylate, dipropylene glycol diacrylate, and allyl acrylate; vinyl compounds such as divinylbenzene and divinyl adipate; diallyl phthalate and diallyl Examples thereof include allyl compounds such as malate and triallyl cyanurate, and these may be used in combination of two or more.

The crosslinked alkyl (meth) acrylate-based elastic material can be prepared by adjusting the amount of the surfactant used in the polymerization or the amount of the aqueous medium to be used, so that the average particle size of the crosslinked alkyl (meth) acrylate-based elastic emulsion particles is increased. The diameter is preferably adjusted to 0.05 to 0.30 μm. If the average particle diameter is less than 0.05 μm, the mechanical strength of the acrylic resin coating tends to decrease,
If it exceeds μm, whitening tends to occur easily, which is not preferable. Further, the crosslinked alkyl (meth) acrylate-based elastic body preferably has a gel content of 80% or more and a swelling degree of 15 or less measured by the following method.

Method for measuring gel content and degree of swelling : a predetermined amount (W ₀ ) of a crosslinked alkyl (meth) acrylate-based elastic material was collected, swelled after immersion in methyl ethyl ketone for 48 hours at room temperature (W ₁ ), and The weight (W ₂ ) of the swollen sample after drying with a vacuum dryer is measured, and calculated by the following equation.

[0036]

## EQU1 ## Gel content = (W ₂ / W ₀ ) × 100 (%) Swelling degree = (W ₁ −W ₂ ) / W ₀

The gel content and the degree of swelling are determined by adjusting the type and amount of the crosslinking monomer, the temperature at which the crosslinked alkyl (meth) acrylate-based elastic material is polymerized, the type and amount of the initiator, and the amount of the crosslinked alkyl (meth). Since it is influenced by various polymerization conditions such as a method of adding a monomer constituting the meth) acrylate-based elastic material and the presence or absence of a molecular weight modifier, it may be appropriately adjusted. If the gel content is less than 80%, the effect of improving the mechanical strength, especially the impact resistance, when formed into a coating tends to decrease, which is not preferable. On the other hand, if the degree of swelling is more than 15, the coating tends to whiten, which is not preferable.

2-1-2. Graft copolymer Crosslinked alkyl (meth) obtained in 2-1-1 above
Formula (1) in the presence of acrylate-based elastic particles
The graft copolymer having a crosslinked alkyl (meth) acrylate-based elastomer as a trunk is obtained by polymerizing an alkyl (meth) acrylate monomer or a mixture of an alkyl (meth) acrylate monomer and a vinyl monomer copolymerizable therewith. A polymer is obtained. Alkyl (meth)
Examples of the acrylate monomer and the vinyl monomer copolymerizable therewith include those used in the production of the above-mentioned 2-1-1 crosslinked alkyl (meth) acrylate elastic material. In this case, the kind of the monomer and the type of the monomer are set so that the glass transition temperature (Tg) of the (co) polymer itself obtained from the monomer component to be grafted is 50 ° C. or more.
It is preferred to choose a combination. When the Tg is less than 50 ° C., the vinyl chloride resin film for agricultural use on which the acrylic resin film is formed tends to have poor blocking resistance (easy to block), which is not preferable.

The graft polymerization may be performed by a solution polymerization method, but is preferably performed by an emulsion polymerization method. When the emulsion polymerization method is used, for example, a monomer to be grafted is added to an emulsion of a crosslinked alkyl (meth) acrylate-based elastic material, and if necessary, an emulsifier, a polymerization initiator, a molecular weight regulator, water, and the like are added. It may be performed under the following conditions. The ratio of the crosslinked alkyl (meth) acrylate-based elastic body and the monomer to be grafted is such that the crosslinked alkyl (meth) acrylate-based elastic body (parts by weight) / the monomer to be grafted (parts by weight) = 10/90 to 90/10. Is good. The obtained graft copolymer has a Tg of 50 ° C.
It is preferable that it is above.

2-1-3. Acrylic resin In the acrylic resin for the coating, 2-1-2. Other acrylic resins may be included in addition to the graft copolymer described in (1). As other acrylic resins, for example, acrylic acid ester, methacrylic acid ester (hereinafter referred to as “(meth) acrylic acid ester”) or a mixture of (meth) acrylic acid ester and a vinyl monomer copolymerizable therewith can be used. Acrylic resin, methacrylic resin,
Alternatively, a free acrylic resin or a methacrylic resin generated during the production of the graft copolymer may be used. The proportion of the crosslinked alkyl (meth) acrylate-based elastic material contained in the acrylic resin is in the range of 5 to 80% by weight, preferably 10 to 50% by weight. When the proportion of the crosslinked alkyl (meth) acrylate-based elastic material is less than 5% by weight, the mechanical strength of the acrylic resin film is poor, and when it exceeds 80% by weight, the blocking resistance is poor. The acrylic resin is compatible with the acrylic resin and has a Tg of 5
A thermoplastic resin transparent at 0 ° C. or higher, for example, an epoxy resin,
A urethane resin, a carbonate resin, a saturated polyester resin and the like may be mixed in an amount of about 0.1 to 20% by weight based on the acrylic resin. Further, in addition to these components, auxiliary components such as an antioxidant, a neutralizing agent, an ultraviolet ray inhibitor, a light stabilizer, an antistatic agent, a pigment, a dye, a foaming agent, and a lubricant are added to the acrylic resin in an amount of 0.1%. It can be added in an amount of about 01 to 10% by weight.

3. Agricultural vinyl chloride resin film By forming a coating of the acrylic resin on the surface of the vinyl chloride resin film obtained as described above,
The agricultural vinyl chloride resin film of the present invention is obtained.
As a method for forming the acrylic resin film, for example, an acrylic resin may be dispersed or dissolved in an aqueous solvent or an organic solvent, and this may be applied to the surface of the vinyl chloride resin film and then dried. Examples of the organic solvent include aliphatic hydrocarbons such as heptane and cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; alcohols such as methanol, ethanol, isopropyl alcohol and polyoxyethylene glycol; chloroform, carbon tetrachloride; Halogenated hydrocarbons such as chlorobenzene; esters such as methyl acetate, allyl acetate, and ethyl stearate; trimethylamine, diphenylamine,
Amines such as hexamethylenediamine; and dimethylformamide, dimethylacetamide, dioxane, diethyl ether, diethylenedithioglycol, diacetone alcohol, benzonitrile, dimethylsulfoxide, and the like. These may be used alone or in combination of two or more. Can be used.

Examples of the coating method include a doctor blade coating method, a gravure roll coating method, an air knife coating method, a reverse roll coating method, a dip coating method, a curtain flow coating method, a spray coating method and a rod coating method. Examples of the drying method include a natural drying method, a hot air drying method, an infrared drying method and a far infrared drying method, and the hot air drying method is advantageous in consideration of the drying speed and safety. The temperature condition in this case is 50 ° C. to 200 ° C.
And the time is preferably 10 seconds to 15 minutes. When the acrylic resin is formed as a single film without being in a solution state, a co-extrusion method, an extrusion coating method,
Extrusion lamination and lamination are used.

The thickness of the acrylic resin film is 1 to 10 μm.
m. If the thickness of the coating is less than 1 μm, the dust resistance is poor. If the thickness is more than 10 μm, the coating may peel off from the vinyl chloride resin film due to the difference in flexibility between the vinyl chloride resin film and the coating. Cracks may occur, reducing the strength of the entire film. Before forming the acrylic resin film, the surface of the vinyl chloride resin film is washed in advance with alcohol or water, plasma discharge treatment, corona discharge treatment, or undercoating with another paint or primer. Pre-processing may be performed. In the agricultural vinyl chloride resin film of the present invention, when the acrylic resin film is formed only on one surface, the film is stretched so that the side provided with the film is outside the house or tunnel when used.

[0044]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited by the following Examples unless it exceeds the gist of the invention. <Evaluation of film> Vinyl chloride resin film on which acrylic resin film is formed (hereinafter referred to as "film")
For each of the following items, the performance was evaluated. Initial appearance The appearance of the film was visually observed. The evaluation criteria are as follows. A: Colorless and excellent in transparency.・ ・ ・: Somewhat white, but transparent. Δ: White and translucent. X: cloudy and devitrified.

Flexibility of Acrylic Resin Coating Each film was cut into a width of 5 cm and a length of 15 cm, and alternately folded at a distance of 2 cm in a direction perpendicular to the length direction. In this state, a load of 2 kg was applied from the top and 15
It was left for 24 hours in a thermostat kept at ℃. Next, the load is taken, the fold of the fill is extended, and the acrylic resin coating (hereinafter referred to as “coating”) (especially at the fold) is removed.
The appearance was visually observed. The evaluation criteria are as follows.・ ・ ・: No change was observed in the film at the fold. Δ: Cracks are observed in the film at the fold. ×: Cracks are remarkably observed in the film at the fold.

Adhesion (acceleration test) 300 cc of water (50 ° C.) was put into a 500 cc beaker, and the beaker was coated with a film so that the surface on which the coating was formed was on the beaker side. Then, the beaker was immersed in water up to 2/3 from the bottom with the beaker tilted 10 degrees from the horizontal plane, and left in a constant temperature room at 25 ° C. for 5 hours. Next, using this film, a cellophane tape was adhered to the surface on which the film was formed, and when the cellophane tape was peeled off, the state of peeling of the acrylic resin film was visually observed. The evaluation criteria are as follows. ◎: The film was completely removed without peeling.・ ・ ・: A part (less than 1/3) of the coating was peeled off. Δ: One-third or more and less than two-thirds of the coating peeled off. X: A film in which 2/3 or more of the coating was peeled off.

<Evaluation of Film after Outdoor Expansion> Each film was placed on a rooftop house (3 m wide, 5 m deep, 1.5 m high, ridge height 30 m) installed on a test field in Isshi-gun, Mie Prefecture.
Degree), cover the surface with the coating outside the house,
A two-year expansion test was conducted from March 1995 to February 1997. The performance of the stretched film was evaluated for the following items. Appearance of film after stretching The appearance of the film was visually observed. The evaluation criteria are as follows. A: No change in appearance such as discoloration was observed.・ ・ ・: Some change in appearance such as slight discoloration is observed. Δ: A change in appearance such as discoloration is considerably observed. ×: Discoloration is observed on the entire surface. The elongation retention of the film was calculated by the following equation.

[0048]

## EQU2 ## (Elongation of film after stretching / Elongation of film before stretching) × 100 (%)

The elongation is a value measured according to "9.5 Elongation in cold resistance test" described in JIS K 6732. Adhesion test (acceleration test) Tests and evaluations were performed in the same manner as the contents performed for the film after stretching. Dust resistance The value calculated from the following equation (transmittance retention) was evaluated.

[0050]

(Equation 3)

The evaluation criteria are as follows. A: The transmittance retention is 90% or more.・ ・ ・: Transmittance retention in the range of 70 to 89%. Δ: The transmittance retention was in the range of 50 to 69%. X: The transmittance retention is less than 50%. The light transmittance is a direct light transmittance at a wavelength of 555 nm (measured by an EPS-2U model manufactured by Hitachi, Ltd.).

<Examples 1 to 5, Comparative Examples 1 to 4> Base film Polyvinyl chloride (average degree of polymerization = 1400) 100 parts by weight Dioctyl phthalate 50 parts by weight Epoxy resin 3 parts by weight Barium-zinc composite liquid stabilizer 1.5 parts by weight Barium stearate 0.2 parts by weight Zinc stearate 0 0.4 parts by weight Sorbitan laurate 1.5 parts by weight Organophosphate described in Table-1 Ultraviolet absorber described in Table-1 Light stabilizer described in Table-1 The resin composition having the above composition was mixed with a supermixer using a super mixer.
After stirring and mixing for 0 minutes, the mixture was kneaded on a mill roll heated to 180 ° C. to form a vinyl chloride resin film (base film) having a thickness of 0.15 mm.

II. Acrylic resin solution II-1. Preparation of Acrylic Resin A Solution Crosslinked Alkyl (meth) acrylate Elastic Body 300 parts by weight of deionized water (hereinafter referred to as “parts”), potassium persulfate 0.3 part, disodium phosphate 12 0.5 parts of water salt, sodium hydrogen phosphate dihydrate 0.3
After the parts have been charged and sufficiently purged with nitrogen, the internal temperature is increased to 70 ° C.
The temperature rose. While maintaining the internal temperature at this temperature and stirring,
A mixture consisting of 19.8 parts of styrene, 69.3 parts of butyl acrylate, 0.9 part of allyl methacrylate, and 2.5 parts of sodium dioctylsulfosuccinate (emulsifier) was continuously added over 2 hours. Immediately after completion of the addition, 1.0 part of t-butylperoxy-2-ethylhexanoate,
A mixture consisting of 2.2 parts of styrene, 7.7 parts of butyl acrylate and 0.1 part of allyl acrylate was added. After completion of the addition, the internal temperature was raised to 90 ° C. over 30 minutes,
The reaction was continued for a time to obtain an emulsion of a crosslinked alkyl (meth) acrylate-based elastic material (hereinafter, referred to as “crosslinked elastic material”). The average particle size of this crosslinked elastic body was 0.20 μm, the gel content was 97.1%, and the degree of swelling was 7.2.

Preparation of Graft Copolymer In a polymerization vessel, the crosslinked elastic emulsion 400 obtained above was added.
The mixture was purged with nitrogen while stirring, and the internal temperature was reduced to 8%.
The temperature was raised to 0 ° C. While maintaining the internal temperature at this temperature, an aqueous solution in which 0.15 part of sodium formaldehyde sulfoxylate was dissolved in 3.0 parts of deionized water was added with stirring, and then 30.0 parts of methyl methacrylate and n-octyl mercaptan were added. A mixture of 0.03 parts and 0.15 parts of paramenthane hydroperoxide (50% solution) was continuously added over 30 minutes. After completion of the addition, the polymerization reaction was continued for another 30 minutes to obtain a graft copolymer emulsion.
The glass transition temperature (Tg) of the copolymer itself obtained from the grafted monomer component was 108 ° C. Next, the polymerization vessel was cooled down to 20 ° C., and 10 parts of sodium chloride was continuously added to the obtained graft copolymer emulsion with stirring over 30 minutes to carry out salting out. The resultant was separated by filtration, washed with water, and dried to obtain a powdery graft copolymer.

Preparation of Acrylic Resin A Solution To 6.5 parts of the graft copolymer obtained above, methacrylic resin (methyl methacrylate / ethyl methacrylate
And 13.5 parts of beads).
This mixture is mixed with 64 parts of methyl ethyl ketone and 16 parts of toluene.
Into a mixed solvent consisting of
An acrylic resin A solution having a resin solid content concentration of 20% by weight was prepared. II-2. Preparation of Acrylic Resin B Solution Crosslinked Alkyl (meth) acrylate Elastic Material In a polymerization vessel, 250 parts of deionized water, 2.0 parts of sodium dioctylsulfosuccinate, and 0.05 parts of sodium formaldehyde sulfoxylate are charged and replaced with nitrogen. Was done. While stirring the contents of the polymerization vessel, 1.6 parts of methyl methacrylate, 8 parts of butyl acrylate, 0.4 part of 1,3-butylene methacrylate, 0.1 part of allyl methacrylate, and 0 parts of cumene hydroperoxide were added. A mixture of .04 parts was charged. The temperature inside the polymerization vessel was raised to 70 ° C., and the reaction was continued at this temperature for 60 minutes. Subsequently, 1.5 parts of methyl methacrylate, 22.5 parts of butyl acrylate, 1,3-butylene methacrylate 1
Parts, 0.25 parts of allyl methacrylate and 0.13 parts of cumene hydroperoxide. 7 temperature inside the polymerization can
The temperature was raised to 0 ° C., and the reaction was continued at this temperature for 60 minutes. Subsequently, 1.5 parts of methyl methacrylate, 22.5 parts of butyl acrylate, 1.0 part of 1,3-butylene methacrylate, 0.25 part of allyl methacrylate and 0.13 part of cumene hydroperoxide were added to the polymerization vessel. 60 parts of mixture
It was added over a minute. The internal temperature of the polymerization vessel was raised to 70 ° C., and the reaction was continued at this temperature for 30 minutes to obtain a crosslinked elastomer emulsion. The average particle size of this crosslinked elastic body is 0.12 μm
The gel content was 90% and the degree of swelling was 10.

Preparation of Graft Copolymer An aqueous solution prepared by dissolving 0.01 part of sodium formaldehyde sulfoxylate in 3 parts of deionized water was added to a polymerization vessel containing the above-mentioned crosslinked elastic emulsion, and then methyl methacrylate 5 , 5 parts of butyl acrylate, 0.1 part of allyl acrylate and 0.03 part of cumene hydroperoxide were continuously added over 30 minutes. After completion of the addition, the polymerization reaction was continued for another 30 minutes. An aqueous solution in which 0.05 part of sodium formaldehyde sulfoxylate was dissolved in 3 parts of deionized water was added to the polymerization vessel, and the temperature was raised to 80 ° C. to give methyl methacrylate.
A mixture consisting of 25 parts, 2.75 parts of butyl acrylate, and 0.13 parts of paramenthane hydroperoxide (50% solution) was added over 30 minutes. After completion of addition, 80 ° C
For 30 minutes to obtain a graft copolymer emulsion. The glass transition temperature (Tg) of the copolymer obtained from the monomer component grafted to the outermost layer was 103 ° C. Next, the temperature inside the polymerization vessel was lowered to 20 ° C,
After 10 parts of sodium chloride was continuously added to the obtained graft copolymer emulsion with stirring over 30 minutes to carry out salting out, the graft copolymer was separated by filtration, washed with water, and dried. Thus, a powdery graft copolymer was obtained.

Preparation of Acrylic Resin B Solution 20 parts of the graft copolymer obtained above were dissolved in a mixed solvent of 64 parts of methyl ethyl ketone and 16 parts of toluene while stirring, and the resin solid content was 20 parts. weight%
Was prepared. II-3. Production of Acrylic Resin C Solution Crosslinked Alkyl (meth) acrylate Elastic Material II-2. Was used. Production of graft copolymer II-2. The graft copolymer powder produced in the above was used. Further, 70 parts of this graft copolymer in a polymerization can,
150 parts of deionized water was charged, and a mixture of 30 parts of methyl methacrylate and 1 part of benzoyl peroxide was added thereto, and the atmosphere was replaced with nitrogen. The temperature was raised to 70 ° C. with stirring, and the polymerization reaction was performed at this temperature for 3 hours. Then, a graft copolymer emulsion was obtained. The Tg of the copolymer obtained from the monomer component grafted on the outermost layer was 73 ° C. Next, the internal temperature of the polymerization vessel was lowered to 20 ° C., and 10 parts of sodium chloride was continuously added to the obtained graft copolymer emulsion with stirring over 30 minutes to carry out salting out. The polymer was separated by filtration, washed with water, and dried to obtain a powdery graft copolymer.

To the graft copolymer finally obtained in the preparation of the acrylic resin C solution, 170 parts of methyl ethyl ketone and 80 parts of toluene were added to prepare an acrylic resin solution C having a resin solid content concentration of 20% by weight. did. II-4. Preparation of Acrylic Resin D Solution Acrylic Polymer In a reactor equipped with a thermometer, a stirrer, a reflux condenser and a nozzle for adding raw materials, 70 parts of methyl ethyl ketone, 30 parts of toluene, 1 part of benzoyl peroxide and 60 parts of methyl methacrylate were added. , 35 parts of butyl methacrylate and 5 parts of methacrylic acid were charged, and stirred under a nitrogen gas stream.
Further, 0.5 part by weight of benzoyl peroxide was added at 3 ° C., and the reaction was continued for 3 hours at the same temperature to obtain an acrylic polymer.

Preparation of Resin Solution D 170 parts of methyl ethyl ketone and 80 parts of toluene were added to the acrylic polymer solution obtained in the above, to prepare an acrylic resin D solution having a resin solid content concentration of 20% by weight. III. Formation of Coating Film The above-mentioned various acrylic resin (A to D) solutions are applied to one side of a vinyl chloride resin film serving as a substrate by applying # 1 (0.7 μm), # 3 (1. 5 μm),
Using a bar coater of any one of three types of # 5 (3.0 μm), each was coated, and then the film was coated with 1 bar.
It was kept in an oven at 30 ° C. for 1 minute to evaporate the solvent and form a coating. The thickness of the coating of each of the obtained films was as shown in Table 1. For each film,
The performance was evaluated. Table 2 shows the results.

<Explanation of Results> The vinyl chloride resin film for agricultural use of the present invention is excellent in weather resistance, dust resistance and durability, and is excellent in flexibility and adhesion of the coating (Examples 1 to 5).
5). On the other hand, when the organic phosphoric acid ester is not added to the base film, the weather resistance is poor (Comparative Examples 1 and 2). Further, the film formed by using a coating of an acrylic resin other than the specific acrylic resin of the present invention is inferior in the weather resistance of the film, the flexibility of the coating, and the durability of the dust resistance (Comparative Example 3). Even when a coating similar to the present invention is formed, when the thickness of the coating is thinner than the coating of the present invention,
The weather resistance, dust resistance and durability of the coating are inferior (Comparative Example 4).

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

As described above, the present invention has the following effects, and its agricultural utility value is extremely large. (1) Even if the vinyl chloride resin film for agricultural use of the present invention is stretched outdoors for a long period of time, the degree of discoloration, deterioration of physical properties and dust resistance is small, and it can be used for a long period of time. (2) The agricultural vinyl chloride resin film of the present invention has high adhesion between the base film and the coating formed on the surface thereof, so that the coating does not easily peel off and can be used for a long time. (3) The vinyl chloride resin film for agriculture of the present invention is excellent in mechanical strength and impact resistance of the acrylic resin film formed on the surface of the substrate, so that the impact during film processing, at the time of stretching, and after the stretching. Cracks are unlikely to occur even under such conditions, and whitening of the film and peeling of the coating are also unlikely to occur.

Claims (3)

[Claims] 1. An acrylic resin film having a thickness of 1 to 10 μm is formed on one or both sides of a vinyl chloride resin film containing an organic phosphate or a metal salt of an organic phosphate. In the presence of crosslinked alkyl acrylate-based elastic particles or crosslinked alkyl methacrylate-based elastic particles (hereinafter collectively referred to as “crosslinked alkyl (meth) acrylate-based elastic particles”), the following structural formula ( An alkyl acrylate monomer, an alkyl methacrylate monomer or a mixture thereof (hereinafter collectively referred to as "alkyl (meth) acrylate monomer") represented by 1) or an alkyl (meth) acrylate monomer as a main component and copolymerizable therewith. Crosslinked alkyl (meth) obtained by polymerizing a mixture with (T) a graft copolymer containing an acrylate-based elastic body as a backbone; and (b) the proportion of the crosslinked alkyl (meth) acrylate-based elastic body in the acrylic resin is 5 to 80% by weight. Agricultural PVC resin film. Embedded image (R ₁ in the structural formula represents hydrogen or a methyl group, and n represents 1 to 1
Each means an integer of 2) 2. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin film contains an ultraviolet absorber. 3. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin film contains a light stabilizer.