JP2003299416A - Vinyl chloride resin film for agriculture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film for agricultural use having excellent transparency and low-temperature properties (strength and impact resistance). <P>SOLUTION: The vinyl chloride resin film for agricultural use is produced by compounding 100 pts.wt. of a vinyl chloride resin with 3.5-10 pts.wt. of a silicone rubber having an average particle diameter of 0.01-10 μm and 40-60 pts.wt. of a plasticizer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vinyl chloride resin film for agriculture. More specifically, it relates to an agricultural vinyl chloride resin film having excellent tear strength, strength and impact resistance at low temperatures.

[0002]

2. Description of the Related Art In recent years, in order to efficiently cultivate useful plants, accelerated cultivation has been actively carried out in a house or a tunnel. A vinyl chloride resin film is often used as a material for covering the house or the tunnel because of its excellent weather resistance, transparency and heat retention.

However, the soft vinyl chloride resin film contains a plasticizer as a resin softening agent,
This plasticizer has a large temperature sensitivity, and is poorly stretched and easily broken particularly when it is used for spreading in cold regions. Further, there is a problem that even after the stretching, the film is easily torn when an external force such as wind, snow, hail, and arale is applied to the film. Therefore, as a method of improving physical properties such as impact resistance in cold regions, the amount of plasticizer in the vinyl chloride resin film for agriculture as described below is increased, or plasticization such as blending of a cold resistant plasticizer is performed. A method for compounding agents has been proposed.

It is known that the method of increasing the amount of the plasticizer in the vinyl chloride resin film has an effect of improving the low temperature strength. However, in this method, the film becomes sticky at high temperatures such as summer. It is known that it will sag and sag. Therefore, a method has been proposed in which a cold-resistant plasticizer is blended in order to improve the physical properties at low temperatures without increasing the amount of the plasticizer too much (Japanese Patent Laid-Open No. 58-49742, etc.). However, this method generally has poor compatibility with vinyl chloride resins, and has the drawback of bleeding and poor heat resistance. Further, there is a defect that weather resistance is poor (browning, etc.).

[0005]

Under the circumstances, the present inventors provide a vinyl chloride resin film for agriculture which is excellent in transparency and physical properties (strength and impact resistance) at low temperature. The purpose was to.

[0006]

However, the gist of the present invention is that 3.5 to 10 parts by weight of silicone rubber having an average particle diameter of 0.01 μm to 10 μm is added to 100 parts by weight of vinyl chloride resin. And a plasticizer in an amount of 40 to 60 parts by weight, which is a vinyl chloride resin film for agriculture.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
In the present invention, the vinyl chloride resin means not only polyvinyl chloride but also a copolymer containing vinyl chloride as a main component.
Examples of the monomer compound copolymerizable with vinyl chloride include vinylidene chloride, ethylene, propylene, acrylonitrile, maleic acid, itaconic acid, acrylic acid, methacrylic acid and vinyl acetate. These vinyl chloride resins may be produced by any of conventionally known production methods such as emulsion polymerization method, suspension polymerization method, solution polymerization method and bulk polymerization method.

In the present invention, the vinyl chloride resin has an average degree of polymerization of 1100 or more and 2000 or less, preferably 1500 or more and 2000 or less, more preferably 160.
A vinyl chloride resin having a Mw / Mn of 1.9 or more and 2.3 or less and 0 or more and 1800 or less is used. If the average degree of polymerization is larger than 1850, the processability is deteriorated, which is not preferable, and if the average degree of polymerization is smaller than 1300, the physical properties are not improved, which is not preferable.

In order to impart flexibility to the vinyl chloride resin film as the above-mentioned substrate, 40 to 60 parts by weight, preferably 40 to 55 parts by weight is added to 100 parts by weight of the resin.
It is compounded in parts by weight. If the amount is less than 40 parts by weight, the flexibility at low temperature is poor and sufficient low temperature physical properties cannot be obtained. On the other hand, if the amount exceeds 60 parts by weight, the handling property (stickiness etc.) at room temperature is deteriorated, and the workability during film forming is deteriorated, which is not preferable.

Examples of plasticizers that can be used include di-
Phthalic acid derivatives such as n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate and diisodecyl phthalate; isophthalic acid derivatives such as dioctyl phthalate; adipic acid derivatives such as di-n-butyl adipate and dioctyl adipate; di-n Maleic acid derivatives such as butyl maleate; citric acid derivatives such as tri-n-butyl citrate; itaconic acid derivatives such as monobutyl itaconate; oleic acid derivatives such as butyl oleate; ricinoleic acid derivatives such as glycerin monoricinoleate; In addition, epoxidized large oil, epoxy resin-based plasticizer, etc. may be mentioned. Further, in order to impart flexibility to the resin film, it is not limited to the above-mentioned plasticizer, and for example, thermoplastic polyurethane resin, polyvinyl acetate, etc. can be used.

The silicone rubber of the present invention includes, for example, dimethyl silicone rubber, methylphenyl silicone rubber,
Examples thereof include silicone rubber such as methyl vinyl silicone rubber and methylphenyl vinyl silicone rubber. The average particle diameter of these is 0.01 μm to 10 μm, and preferably 0.01 μm to 1.0 μm. If it is too small, the effect of improving impact resistance cannot be obtained. If it is too large, the transparency is lowered, which is not preferable. The amount of the silicone rubber compounded is in the range of 3.5 to 10 parts by weight, preferably 4 to 8 parts by weight, based on 100 parts by weight of the vinyl chloride resin. If it is less than 3.5 parts by weight, the impact resistance improving effect cannot be obtained. If it is 10 parts by weight or more, the transparency is lowered and the impact resistance improving effect cannot be obtained, which is not preferable.

[0012] Of course, in addition to the above, the vinyl chloride-based resin may also include, if necessary, known resin additives such as anti-fog agents, anti-fog agents, and lubricants, which are usually added to synthetic resins for molding. ,
Various additives such as heat stabilizers, UV absorbers, light stabilizers, organophosphate metal salts, inorganic substances, antioxidants, stabilizing aids, antistatic agents, mildew-proofing agents, algae-proofing agents and coloring agents can do.

Other examples include epoxy plasticizers and organic phosphates. As an epoxy plasticizer,
There are epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil, and epoxy resins. The addition amount of these epoxy plasticizers is 0.
The amount is 01 to 10 parts by weight, preferably 0.1 to 5 parts by weight.

As the organic phosphate ester type plasticizer, triisopropylphenyl phosphate, isodecyldiphenyl phosphate, tris (isopropylphenyl)
There are phosphate, tributyl phosphate, triethyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, trixylenyl phosphate, etc. Among them, tricresyl phosphate and trixylenyl phosphate are particularly preferable. The blending amount of these plasticizers is appropriately in the range of 1 to 10 parts by weight, particularly 2 to 8 parts by weight, based on 100 parts by weight of the vinyl chloride resin.

As the antifogging agent, a nonionic surfactant is preferable, and an ether type one such as polyoxyethylene ether, polyoxyethylene alkylaryl ether, polyoxyethylene polyoxypropylene ether, polyhydric alcohol and the like. Examples thereof include ester type of partial esterified product of fatty acid, polyoxyethylene ether of glycerin ester, and ether ester type of sorbitan ester such as polyoxyl ethylene ether. Examples of suitable nonionic surfactants are shown below.

(A) Partial ester (b) alkylene oxide of polyhydric alcohol such as sorbitan, sorbitol, mannitol, mannitol, glycerin, diglycerin and fatty acid having 12 to 22 carbon atoms is ethylene oxide or propylene oxide, The addition mole number is 1 to 20 moles, the polyhydric alcohol is sorbitan, sorbitol, mannitol, mannitol, glycerin, diglycerin,
A mixture of a fatty acid ester (c) (a) and (b) of a polyoxylyalkylene polyhydric alcohol in which the fatty acid has 12 to 22 carbon atoms.

These mixtures are obtained as a mixture of monoesters, diesters and triesters of polyhydric alcohols. Generally, an ester mixture having a composition containing a high proportion of the diester component is suitable. The compounding amount of the nonionic surfactant is selected from the range of 0.5 to 5 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. Particularly, 1.0 to 3.0 parts by weight is suitable.

Examples of the antifogging agent include a fluorine-based surfactant. Specifically, C of the hydrophobic group of ordinary surfactants is used.
A surfactant in which a part or all of H bound to is substituted with F, particularly a surfactant containing a perfluoroalkyl group or a perfluoroalkenyl group. The blending amount of the fluorine-based surfactant is vinyl chloride resin 1
0.01 parts by weight or more and 0.5 parts by weight or less per 100 parts by weight is sufficient, and the preferable range of the compounding amount is 0.02 to 0.
2 parts by weight.

The vinyl chloride resin film composition according to the present invention preferably contains a specific anti-adhesive agent.
Examples of the anti-adhesive agent include methylenebisstearamide having a melting point of 140 to 146 ° C., ethylenebislaurylamide having a melting point of 156 to 160 ° C., N, N′-dioleyl adipamide having a melting point of 116 to 120 ° C., and melting point 143. ~ 14
Examples include N, N′-distearyl adipamide at 4 ° C. and the like, but it is particularly preferable to mix a mixture of methylenebisstearoamide and one or more selected from the other three. The compounding amount is preferably in the range of 0.05 to 2 parts by weight, based on 100 parts by weight of the vinyl chloride resin, the total amount of methylenebisstearamide and the specific anti-sticking agent. If the total amount is less than this range, the workability for winding and unwinding will not be sufficiently excellent, and if the total amount is more than this range, the substances added after film formation will spout or hinder the antifogging property. The problem occurs, which is not preferable. Of the above ranges, the range of 0.05 to 1.0 parts by weight is particularly preferable. Furthermore, it is preferably in the range of 0.1 to 1.0 part by weight.

As the lubricant or heat stabilizer, fatty acid lubricants, fatty acid amide lubricants, ester lubricants, polyethylene wax, liquid paraffin, chelating agents such as organic phosphite compounds, and phenols, which are generally used for agricultural films, are used. And β-diketone compounds. As the β-diketone compound, dibenzoylmethane, methoxybenzoyl · benzoylmethane, chlorobenzoyl · benzoylmethane, palmitylbenzoylmethane and the like are preferable. The blending amount of these lubricants and heat stabilizers is in the range of 0.01 to 2.0 parts by weight, particularly 0.04 to
1.0 part by weight is preferred.

The ultraviolet absorber may be any one which is usually blended in an agricultural vinyl chloride film, and various kinds of ultraviolet absorbers such as benzotriazole type, benzophenone type, salicylate type, hydroquinone type and cyanoacrylate type can be mentioned. To be For example, Japanese Patent Publication Sho-62-38
No. 143, column 7, line 27 to column 9, line 34; JP-B No. 62-53543, column 7, line 13 to line 36, and particularly a benzotriazole-based ultraviolet absorber. Agents and benzophenone-based UV absorbers are preferred. Specific examples include the following.

2- (2'-hydroxyphenyl) benzotriazole and 2- (2'-hydroxy-5'-methylphenyl) which are benzotriazole type ultraviolet absorbers.
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-ethylsulfone benzotriazole, 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'-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-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-ethylsulfone benzotriazole, 2- (2'-hydroxy-4'-octoxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-methoxy Phenyl)
-5-methylbenzotriazole, 2- (2'-hydroxy-5'-methylphenyl) -5-carboxylic acid ester benzotriazole, 2- (2'-acetoxy-5'-
Methylphenyl) benzotriazole and the like.

2 which is a benzophenone type ultraviolet absorber
-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,
2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfonebenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4' -Dimethoxybenzophenone, 2-hydroxy-5-chlorobenzophenone, bis- (2-methoxy-4-hydroxy-
5-benzoylphenyl) methane and the like.

The ultraviolet absorbers may be used alone or in combination of two or more. The blending amount thereof is preferably in the range of 0.01 to 3.0 parts by weight, and particularly preferably 0.02 to 2.0 parts by weight, per 100 parts by weight of the vinyl chloride resin.

As the light stabilizer, various compounds which are usually blended in agricultural films can be used, and examples thereof include hindered amine compounds, specifically, JP-A-6-155680. To the compounds described on page 19 and the like. These light stabilizers may be used alone or in combination of two or more. The blending amount is
0.05 to 5.0 per 100 parts by weight of vinyl chloride resin
A range of parts by weight, particularly 0.1 to 2 parts by weight is preferred.

As the organic phosphate metal salt used in the present invention, those represented by the following general formula (II) or (III) are preferable.

[0027]

Embedded image Formula (II)

Embedded image Formula (III)

(In the formula, M is zinc, calcium, barium, magnesium or strontium, and R1, R2 and R3 are each an alkyl group having 1 to 22 carbon atoms, an aryl group, an aralkyl group, an alkylaryl group or an ether bond. Examples of the hydrocarbon group containing an alkyl group, an aryl group, an aralkyl group, an alkylaryl group or an ether bond having 1 to 22 carbon atoms in the general formula (II) or (III). Are as follows.

As the alkyl group, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group,
Isobutyl group, sec-butyl group, tert-butyl group, n-amyl group, neopentyl group, isoamyl group, hexyl group, heptyl group, n-octyl group, isooctyl group, 2-ethylhexyl group, n-nonyl group, isononyl group , Decyl group, lauryl group, tridecyl group, 1-octadecyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, 4-methylcyclohexyl group and the like.

Examples of the aryl group include phenyl group and naphthyl group, and examples of the arylalkyl group include benzyl group, β-phenylethyl group and α-phenylpropyl group. Examples of alkylaryl groups include:
Examples thereof include a tolyl group, a xylyl group, an ethylphenyl group, a butylphenyl group, a tert-butylphenyl group, an octylphenyl group, a nonylphenyl group and a 2,4-di-tert-butylphenyl group.

Examples of the hydrocarbon group containing an ether bond include furfuryl group, tetrahydrofurfuryl group, 5-methylfurfuryl group, α-methylfurfuryl group, methyl cellosolve residue (ether obtained by removing the hydroxyl group from the cellosolve. A hydrocarbon group containing a bond, the same hereinafter), ethyl cellosolve residue, isopropyl cellosolve residue, butyl cellosolve residue, isobutyl cellosolve residue, hexyl cellosolve residue, cyclohexyl cellosolve residue, phenyl cellosolve residue, methylcarbitol Residues (referred to as hydrocarbons containing an ether bond in which the hydroxyl group is removed from carbitol, the same applies hereinafter), ethyl carbitol residues, isopropyl carbitol residues, butyl carbitol residues, isobutyl carbitol residues, triethylene Glycol Monomethyl A Le residues (refers to a hydrocarbon group containing an ether bond other than a hydroxyl group from the ether, the same below), triethylene glycol monoethyl ether residues, triethylene glycol monobutyl ether residue,
2,3-dimethoxy-n-propyl group, 2,2-diethoxyisopropyl group, 3-ethoxy-2-propoxy-
Examples thereof include n-propyl group, nonylphenoxypoly (1-30) ethoxyethyl group, lauroxypoly (1-30) ethoxyethyl group and the like.

At least one compound represented by the general formula (II) and at least one compound represented by the general formula (III) have a molar ratio (former / latter) of 1/9 to 7
A metal salt of an organic phosphoric acid ester obtained by mixing and melting at / 3 is preferable. Among the kinds of metals, zinc, calcium and barium are preferable, and zinc is particularly preferable. The organophosphate metal salt having various substituents as described above can be blended alone or in combination of two or more. The amount of these organic metal phosphates to be compounded is in the range of 0.02 to 5.0 parts by weight, particularly, 100 parts by weight of the vinyl chloride resin.
0.1 to 2 parts by weight is preferable.

In the present invention, an inorganic substance having absorption in the infrared region can be blended for the purpose of improving heat retention. Specific examples include the following. Magnesium carbonate,
Magnesium silicate (talc), silicon oxide, aluminum oxide, barium sulfate, calcium sulfate, magnesium hydroxide, aluminum hydroxide, aluminum hydroxide, calcium hydroxide, metal phosphate, hydrotalcites represented by the following formula (Hydro-or anhydrous-aluminum /
Magnesium basic carbonate); aluminum / zinc basic carbonate lithium carbonate-aluminum hydroxide inclusion compound, and the like. Among these, aluminum hydroxide, magnesium hydroxide, silicon oxide, magnesium carbonate, and hydrotalcite It is particularly preferable that the compounds do not reduce the transparency of the film.

^{Embedded image} (I): M ²⁺ _(1-X) Al ³⁺ _X (OH ⁻ ) ₂ · (A ₁
ⁿ⁻ ) _{x / n} · mH ₂ O (wherein, M ²⁺ represents a divalent metal ion, A ⁿ⁻ represents an n-valent anion, and x, m, and n are 0 <x <
The conditions of 0.5, 0 ≦ m ≦ 2, and 1 ≦ n ≦ 3 are satisfied. ^{) (II): Li + (} Al 3+) 2 (OH -) 6 · (A 2 n-) 1 / n ·
mH ₂ O (In the formula, A ^n- represents an n-valent anion, respectively.
And n satisfy the conditions of 0 ≦ m ≦ 3 and 1 ≦ n ≦ 3, respectively. ) (III): [(Li + (1-X) M 2+ X) (Al 3+) 2 (OH -)
₆ ] ₂ (Si _y O _{(2y + 1)} ²⁻ ) _{(1 + x)} · mH ₂ O (In the formula, M ²⁺ represents a divalent metal ion, and m, x and y are 0 ≦ m. <5, 0 ≦ x <1, 2 ≦ y ≦ 4 are satisfied.) (IV): [(Li ⁺ _(1-X) M ²⁺ _X ) (Al ³⁺ ) ₂ (O
H ⁻ ) ₆ ] ₂ (A ₃ ⁿ⁻ ) _{2 (1 + x) / n} · mH ₂ O (In the formula, M ²⁺ represents a divalent metal ion, and A ⁿ⁻ represents an n-valent anion. , M, x and n are 0 ≦ m <
5, satisfying the conditions of 0.01 ≦ x <1 and 1 ≦ n ≦ 3. ) (V): mAl in _{2 O 3 · (n / p} ) M 2 / p O · X · kH 2 O ( wherein, X represents carbonates, M is an alkali metal or alkaline earth metal, respectively, p is It is the valence of the metal M, and m, n and k are 0.3 ≦ m ≦ 1 and 0.3 ≦ n ≦
2 and 0.5 ≦ k ≦ 4 are satisfied. ) These inorganic substances may be added alone or in combination of two or more, and the compounding amount thereof is 0.1% per 100 parts by weight of the vinyl chloride resin.
A range of 5 to 10 parts by weight, particularly a range of 2 to 10 parts by weight are preferable.

As the compound which can be used as the antioxidant, a phenol type antioxidant and a sulfur type antioxidant can be used. Specifically, 2,6-di-butyl-4-methylphenol-
2,2-methylenebis (6-tert-butyl-4-ethylphenol), dilaurylthiodipropionate and the like can be mentioned. These antioxidants can be used alone or in combination of two or more.

Examples of the compound usable as a stabilizing aid include triphenylphosphite, dioctylphenylphosphite, tris (nonylphenyl) phosphite, diphenylindecylphosphite, trilauryltrithiophosphite, diphenylacid phosphite and the like. Can be raised. These stabilizing aids may be used alone or in combination of two or more.

Examples of the antistatic agent include polyoxyethylene alkylamine, polyglycol ether, p-
Examples thereof include sodium styrene sulfonate. As the mildew-proofing agent and algae-proofing agent, various compounds generally compounded in agricultural vinyl chloride films can be used.
Examples thereof include organic nitrogen compounds, and specific examples include imidazole derivatives, anilide derivatives, urea derivatives, ammonium derivatives, triazine derivatives and phthalimide derivatives. As a colorant, for example, phthalocyanine blue, phthalocyanine green,
Examples include Hansa Yellow, Alizarin Lake, Permanent Red, Quinacridone, and the like. These colorants can also be used alone or in combination of two or more kinds.

The above various resin additives can be selected within a range that does not deteriorate the properties of the film, usually within a range of 5 parts by weight or less with respect to 100 parts by weight of the vinyl chloride resin.
To mix the resin additives with the vinyl chloride resin, weigh the required amount, add a ribbon blender, a Banbury mixer,
A conventionally known compounding machine or mixing machine such as a super mixer may be used.

The resin composition thus obtained is formed into a film by a method known per se, for example, a melt extrusion molding method (including a T-die method and an inflation method),
A conventionally known method such as a calender molding method or a solution casting method may be used. The film thickness is 0.03 ~
0.3 mm range, preferably 0.05-0.2 mm
The range is preferably If it is thinner than 0.03 mm,
The film strength is insufficient and tearing is likely to occur.
If it is thicker than m, the work such as cutting and bonding will be adversely affected. The agricultural resin film of the present invention may be provided with a grid pattern, a stripe pattern, or a fine concavo-convex pattern (texture pattern) on at least one surface of the substrate film.

In order to improve durability and dustproofness, it is preferable to form an acrylic resin film on one side of the agricultural vinyl chloride resin film according to the present invention. The acrylic resin used is 5-40% by weight of hydroxyalkyl (meth) acrylate, and 1 in the molecule.
A polymer obtained by copolymerizing 0 to 20% by weight of an α, β-unsaturated carboxylic acid containing one or two or more carboxyl groups and another vinyl-based monomer copolymerizable therewith is preferable.

The 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 thereof include hydroxybutyl methacrylate, 2-hydroxypentyl acrylate, 2-hydroxypentyl methacrylate, 6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate and the like.

These hydroxyalkyl (meth) acrylate compounds make the resulting acrylic resin easily soluble in an organic solvent, improve the adhesion between the acrylic resin and the base vinyl chloride resin film, and further stain the film surface. It is a component that greatly contributes to the action of suppressing the migration of the plasticizer that comes out. The proportion of this hydroxyalkyl (meth) acrylate in the acrylic resin is 5% by weight.
If it is less than 40% by weight, the solubility with an organic solvent, the adhesion with a substrate film and the effect of improving durability cannot be sufficiently exerted. On the other hand, if it is more than 40% by weight, the cost becomes high and the cost rises. The effect obtained is not large, which is not preferable.

As the α, β-unsaturated carboxylic acid having one or more carboxyl groups in the molecule, acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, aconitic acid, fumaric acid, Examples thereof include crotonic acid and itaconic acid. When these compounds are used in combination with the hydroxyalkyl (meth) acrylate, the adhesion and durability between the acrylic resin and the base film are improved. The amount of these used is preferably 0.5 to 20% by weight. When it is more than this, the property of the films adhering to each other when the film is moistened with water (blocking property when wet) is enhanced, which is not preferable.

Other vinyl monomers copolymerizable with the hydroxyalkyl (meth) acrylate and the α, β-unsaturated carboxylic acid include (meth) acrylic acid alkyl ester or a mixture thereof with alkenylbenzene. Can be given. Examples of the (meth) acrylic acid alkyl ester include acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid-n-propyl ester, acrylic acid isopropyl ester, acrylic acid-n-butyl ester, acrylic acid-2-ethylhexyl ester, Acrylic acid decyl ester, methacrylic acid methyl ester, methacrylic acid ethyl ester, methacrylic acid-
Examples thereof include n-propyl ester, methacrylic acid isopropyl ester, methacrylic acid-n-butyl ester, methacrylic acid-2-ethylhexyl ester, and methacrylic acid decyl ester. Generally, an acrylic group having 1 to 20 carbon atoms in an alkyl group. An acid alkyl ester and / or an alkyl ester of methacrylic acid whose alkyl group has 1 to 20 carbon atoms is used.

Examples of the alkenylbenzene used in the present invention include styrene, α-methylstyrene, vinyltoluene and the like. When a monomer comprising a mixture of such an alkenylbenzene and a (meth) acrylic acid alkyl ester is used, it is usually (meth) though it varies depending on the amount of α, β-ethylenically unsaturated carboxylic acid used. Use 10% of acrylic acid alkyl ester
It is preferable that the content is not less than weight%.

In particular, the acrylic resin of the present invention contains the above-mentioned (meth) acrylic acid alkyl ester and a monomer consisting of a mixture thereof with alkenylbenzene in an amount of 40 to 60.
It is preferable that the content thereof is wt%. When the acrylic resin is surface-treated on the base vinyl chloride resin film, it is possible to mix another resin compatible with the acrylic resin for the purpose of improving the adhesion with the film. As the other resin, a vinylidene fluoride resin, an acrylic resin having a perfluoroalkyl group as a side chain, a cellulose acetate butyrate resin, a silicone resin, or the like is particularly effective.

To polymerize the acrylic resin, a predetermined amount of each monomer is combined and charged in a polymerization vessel together with an organic solvent, a polymerization initiator and, if necessary, a molecular weight modifier are added and heated with stirring. Good.

The acrylic resin film formed on one surface of the vinyl chloride resin film is preferably applied by dissolving the acrylic resin in the above-mentioned organic solvent. To form a film of the acrylic resin on the surface of the vinyl chloride resin film, the acrylic resin is dissolved in an organic solvent, and a spray coating method, a roll coating method, a gravure coating method, a reverse coating method, a dip coating method is used. In addition to the above, it is preferable to apply and dry by various known coating methods such as a screen printing method and a flexographic printing method. The drying method that can be used is, for example, a hot air drying method, an infrared drying method, or a far infrared drying method. The drying temperature is preferably a temperature at which the organic solvent is scattered, that is, a boiling point of the organic solvent in which the acrylic resin is dissolved or higher. The shorter the drying time, the better. Therefore, it is preferable to dry at a temperature not lower than the boiling point of the organic solvent in the shortest possible time.

The thickness of the acrylic resin coating formed on the surface of the base film depends on the thickness of the base film,
Select from the range of 0.5 to 10 μm. When the thickness is more than 10 μm, there is a difference in flexibility between the base film and the coating film, so that a phenomenon such as peeling of the coating film from the base film is likely to occur, and cracks are generated in the coating film to reduce strength of the base film. This phenomenon is not desirable. 0.5
When the thickness is smaller than μm, the effect of improving the durability and dustproofness of the base film is not exhibited, which is not preferable. The thickness of the coating is preferably proportional to the thickness of the base film within the above range.

In practical use of the agricultural vinyl chloride resin film according to the present invention, when the coating is formed on only one side, the side provided with this coating is the outside of the house or tunnel. It is good to spread in this way.

[0050]

EXAMPLES The present invention will be described below based on examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. (Examples 1 to 4, Comparative Examples 1 to 4)

[0051] (1) Manufacture of vinyl chloride resin film Polyvinyl chloride (degree of polymerization shown in Table 1) 100 parts by weight Di-2-ethylhexyl phthalate (parts by weight shown in Table 1) Tricresyl phosphate 5 parts by weight Epoxy resin (trade name "EP-828") 1.5 parts by weight Ba-Zn liquid stabilizer 1.0 part by weight Barium stearate 0.2 parts by weight Zinc stearate 0.4 parts by weight Sorbitan monopalmitate 1.5 parts by weight Methylenebisstearic acid amide 0.4 part by weight 2'4-dihydroxybenzophenone 0.03 parts by weight β-diketone compound (dibenzoylmethane) 0.1 part by weight Hindered amine light stabilizer 0.1 part by weight (Made by Asahi Denka Co., Ltd .: trade name "LA-52") Fluorosurfactant (trade name "Unidyne DS-401") 0.2 parts by weight

The above-mentioned resin raw materials and resin additives were weighed, and the impact modifiers of the types and amounts shown in Table 1 were further mixed therein. After stirring and mixing these for 10 minutes with a super mixer, they were kneaded on a roll heated to 180 ° C., and a vinyl chloride resin film having a thickness of 0.1 mm was produced by an L-type calender device.

(2) Formation of film In a polymerization vessel, 150 parts by weight of isopropyl alcohol and 2
-Add 20 parts by weight of hydroxyethyl methacrylate, 10 parts by weight of acrylic acid, 40 parts by weight of methyl methacrylate and 30 parts by weight of ethyl methacrylate, add 0.5 parts by weight of benzoyl peroxide, and add 8 parts under a nitrogen gas stream.
The polymerization reaction was carried out at 0 ° C. for 10 hours. Isopropyl alcohol was added to the obtained copolymer solution to reduce the solid content to 2
The coating resin was adjusted to 0% by weight. The coating resin was applied to one surface of the base film produced in (1) above by the gravure coating method, and then the solvent was scattered for 10 seconds in a warm air drying oven whose temperature was adjusted to 150 ° C. to disperse the solvent to obtain a thickness. A film of about 2 μm was formed.

Evaluation of Film The performance of the film was evaluated by the following method, and the results are shown in Table 2. (3) Initial Appearance The appearance of the films produced in Examples and Comparative Examples was observed with the naked eye, and the linear light transmittance (555 nm) was measured with an EPS-2U type manufactured by Hitachi, Ltd. The evaluation criteria are as follows. Visual Appearance: A product with surface gloss and no roughness. Δ: Surface gloss, but rough. X: Surface has no gloss and is rough. Straight-line light transmittance ⊚: transmittance of 85% or more. ○: Transmittance of 65% to 84%. Δ: Transmittance of 45% to 64%. X: The transmittance is less than 45%.

(4) Low-temperature physical property impact strength: Nine samples of 10 cm × 10 cm films were prepared, and the thickness of the center part of the sample was measured with a dial gauge specified in JISB-7503. The sample was measured in a room at -15 ° C by a puncture manufactured by Toyo Seiki Co., Ltd. The impact degree is expressed by the following formula. Impact strength = measured value (impact value) / measured thickness x nominal thickness

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

EFFECTS OF THE INVENTION (1) The agricultural vinyl chloride resin film of the present invention has excellent tear strength and excellent physical properties at low temperatures, and tears due to spreading and external forces (wind, snow) after spreading. , Hail, Arale, etc.) is excellent in resistance to breakage. (2) The agricultural vinyl chloride resin film of the present invention can be produced without lowering the film processability.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // (C08L 27/06 C08L 83:04 83:04) (72) Inventor Katsuhiro Fujiwara Nakamura, Aichi Prefecture 2 Oike, Iwazuka-cho, Tokyo Mitsubishi Kagaku M Cave Co., Ltd. Nagoya Office (72) Inventor Kanako Nikaido 2 Oike, Iwatsuka-cho, Nakamura-ku, Aichi Prefecture Mitsubishi Kagaku M Cave Co., Ltd. (72) Inventor Maekawa Eito 2 Oike, Iwazuka-cho, Nakamura-ku, Nagoya, Aichi Mitsubishi Chemical MKV Co., Ltd. Nagoya business office F-term (reference) 2B024 DB01 DB07 2B029 EB02 EB03 EC04 EC19 4F071 AA24 AA67 AA81 AE04 AF16 AF46 AH01 BB04 BB06 BD09 BC01 4 BD055 BD061 BD071 BD091 BF022 CD002 CD162 CH024 CK022 CP033 EC057 EE039 EH047 EH057 EH096 EH106 EH146 EH14 9 EL026 EP028 EU179 EW046 FD010 FD022 FD026 FD059 FD070 FD168 FD314 FD317 GA01

Claims (3)

[Claims] 1. 100 parts by weight of a vinyl chloride resin, 3.5 to 10 parts by weight of a silicone rubber having an average particle diameter of 0.01 μm to 10 μm, and 40 to 60 parts by weight of a plasticizer are blended. A vinyl chloride resin film for agriculture. 2. The vinyl chloride resin has an average degree of polymerization of 150.
It is 0-2000, The vinyl chloride resin film for agriculture of Claim 1 characterized by the above-mentioned. 3. The agricultural vinyl chloride resin film according to claim 1, wherein an acrylic resin film is formed on one or both sides of the vinyl chloride resin film.