JP2001224259A - Vinyl chloride-based resin film for agriculture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a vinyl chloride-based resin film for agriculture, having reduced mutual adhesion without reducing the light transmittance, and excellent in physical properties at a low temperature and resistance to breakage at the time to extension. SOLUTION: This vinyl chloride-based resin film for agriculture is characterized by fine asperity formed on one or both surface of the vinyl chloride-based resin film obtained by mixing (A) a vinyl chloride-based resin, (B) a chlorinated polyethylene and a plasticizer.

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, it is possible to reduce the adhesion between films and to reduce mechanical strength and impact resistance at low temperatures against undesired phenomena such as tearing due to external force (cold, snow, hail, alare, etc.) after stretching. The present invention relates to a vinyl chloride resin film for agricultural use which is excellent and has little reduction in dustproofness after outdoor exposure.

[0002]

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

[0003] However, a soft vinyl chloride resin film contains a plasticizer as a resin softener.
This plasticizer has high temperature sensitivity, and has poor elongation particularly when used in cold areas, and is easily broken. There is also a problem that the film is easily broken when an external force such as wind, snow, hail, or arare is applied to the film even after the expansion. For this reason, as a method of improving physical properties such as elongation and impact resistance in cold regions,
The following methods have been proposed for increasing the amount of a plasticizer in a vinyl chloride resin film for agricultural use, or for blending a plasticizer, such as blending a cold-resistant plasticizer.

It is known that a method of increasing the amount of plasticizer in a vinyl chloride resin film has an effect of improving low-temperature strength. However, in this method, the film becomes sticky at high temperatures such as in summer. It is known to sag or 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 (JP-A-58-49742, etc.). However, this method generally has poor compatibility with a vinyl chloride resin, causing bleeding and poor heat resistance. Further, there is a defect that the weather resistance is poor (browning, etc.).

Another object of the present invention is to improve the workability of an agricultural film used in the side portion of a house, in particular, by reducing the film adhesion in a hoisting and lowering operation for controlling and ventilating the temperature in the house. It is known to use an agricultural film having fine irregularities formed on one or both sides of the film. Further, in order to grow a crop to which scattered light is suitable, an agricultural film having fine irregularities may be used.

However, in the case of an agricultural film having fine irregularities on the surface as described above, there has been a problem that the strength of the film is reduced due to the unevenness.

[0007]

Under such circumstances, the present inventors have reduced the adhesion between films, and
An object of the present invention is to provide an agricultural vinyl chloride resin film that prevents undesired phenomena such as tearing due to external force after stretching, has excellent mechanical strength and impact resistance at low temperatures, and has little decrease in dust resistance after outdoor exposure. And

[0008]

SUMMARY OF THE INVENTION The gist of the present invention resides in one or both surfaces of a vinyl chloride resin film mixed with a vinyl chloride resin (A), a chlorinated polyethylene (B), and a plasticizer. And a vinyl chloride resin film for agricultural use characterized by forming fine irregularities.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. 1. Vinyl Chloride Resin In the present invention, the vinyl chloride resin refers to 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 an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, and a bulk polymerization method.

In the present invention, the vinyl chloride resin having an average degree of polymerization of from 1,000 to 2,500, preferably from 1,100 to 2,000 is used.
Two types having different average polymerization degrees may be mixed.
This mixing method is generally a method of mixing two kinds of resins at the time of film forming process.
A method in which resins having different average polymerization degrees are mixed may be used.

In order to impart flexibility to the vinyl chloride resin film serving as the base, 30 to 60 parts by weight, preferably 40 to 55 parts by weight, per 100 parts by weight of the resin is used.
It is blended by weight. If the amount is less than 30 parts by weight, sufficient low-temperature physical properties cannot be obtained due to poor flexibility at low temperatures. On the other hand, if the amount exceeds 60 parts by weight, it is not preferable because handleability (stickiness, etc.) at normal temperature is deteriorated and workability during film forming processing is reduced.

Examples of the plasticizer that can be used include, for example, 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 malate; 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; Other examples include epoxidized large oils and epoxy resin plasticizers. Further, in order to impart flexibility to the resin film, the resin film is not limited to the above-described plasticizer, and for example, a thermoplastic polyurethane resin, polyvinyl acetate, or the like can be used.

2. Chlorinated polyethylene The chlorinated polyethylene of the present invention is a polyethylene as a raw material, which is obtained by homopolymerization of ethylene or ethylene and 3
Those obtained by copolymerizing an α-olefin having 12 or less (preferably 3 to 9) carbon atoms of 0% by weight or less (preferably 20% by weight or less) are preferable.

Specific examples of the α-olefin include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and the like. As the polyolefin as a raw material, particularly, one obtained by homopolymerizing ethylene is preferable. The chlorinated polyethylene used in the present invention employs a method of chlorinating polyethylene powder or particles in an aqueous suspension or chlorinating polyethylene dissolved in an organic solvent.

The amount of the chlorinated polyethylene to be added to the vinyl chloride resin is 0.5 to 20 parts by weight, preferably 0.1 to 20 parts by weight.
5 to 10 parts by weight is preferred. If it is less than 0.5, the initial properties and post-weathering properties are not improved, and if it is too large, the film becomes cloudy, which is not preferable. Particularly within the above range, 1.
0 to 7 parts by weight is preferred. The chlorine content of the chlorinated polyethylene must be in the range of 15 to 50% by weight. If the amount is less than 15% by weight, the compatibility with the vinyl chloride resin is inferior and the film becomes cloudy, which is not preferable. If the amount is more than 50% by weight, the physical properties at low temperatures are not improved. Even within the above range, particularly 30 to 45
% By weight is preferred.

[0016] The melt index of the chlorinated polyethylene must be in the range of 0.5 to 150 g / 10 minutes. If it is less than 0.5 g / 10 min, the compatibility with the vinyl chloride resin is inferior and the film becomes cloudy, and if it is more than 150 g / 10 min, the physical properties are not improved in proportion to the added amount, which is not preferable. Even within the above range, especially 1.0 to
130 g / 10 min is preferred. The crystallinity of the chlorinated polyethylene must be between 0 and 30%. In the range higher than 30%, the compatibility with the vinyl chloride resin is poor,
It is not preferable because it bleeds on the film surface. Even within the above range, 20% or less is particularly preferable.

Of course, in addition to the above, known resin additives which are usually blended with the synthetic resin for molding, such as antifogging agents, antifogging agents, lubricants, etc. ,
Various additives such as heat stabilizers, ultraviolet absorbers, light stabilizers, metal organic phosphates, inorganic substances, antioxidants, stabilizing aids, antistatic agents, antifungal agents, antialgal agents and coloring agents. Can be blended.

Other examples include an epoxy plasticizer and an organic phosphate. As an epoxy plasticizer,
There are epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil and epoxy resins. These epoxy plasticizers are added in an amount of 0.1 to 100 parts by weight of the resin.
The amount is from 0.01 to 10 parts by weight, preferably from 0.1 to 5 parts by weight. The compounding amount of the organic phosphate plasticizer is
An appropriate amount is 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, nonionic surfactants are preferable, and ether-type ones such as polyoxyethylene ether, polyoxyethylene alkylaryl ether and polyoxyethylene polyoxypropylene ether, and polyhydric alcohols And ester type such as polyoxyethylene ether of glycerin ester and polyoxyl ethylene ether of sorbitan ester. Hereinafter, suitable nonionic surfactants will be exemplified.

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

These mixtures are obtained as mixtures of monoesters, diesters and triesters of polyhydric alcohols. Generally, an ester mixture having a high content of the diester component is preferred. The blending amount of the nonionic surfactant is selected from the range of 0.5 to 5 parts by weight based on 100 parts by weight of the vinyl chloride resin. In particular, 1.0 to 3.0 parts by weight is appropriate.

Examples of the antifog include fluorine-based surfactants. Specifically, the C of the hydrophobic group of a normal surfactant
Is a surfactant in which part or all of H bonded 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 1 vinyl chloride resin.
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 0.1 part by weight.
2 parts by weight.

It is preferable that the vinyl chloride resin film composition according to the present invention contains a specific antiblocking agent.
Examples of the anti-adhesion agent include methylene bisstearamide having a melting point of 140 to 146 ° C and a melting point of 156 to 160 ° C.
Ethylene bis lauramide, N, N'-dioleyl adipamide having a melting point of 116 to 120 ° C, melting point 143 to 14
Examples thereof include N, N'-distearyl adipamide at 4 ° C., and it is particularly preferable to mix a mixture of methylene bis-stearamide and at least one selected from the other three. . The amount is preferably in the range of 0.1 to 2 parts by weight based on 100 parts by weight of the vinyl chloride resin. Of the above ranges, a range of 0.2 to 1.5 parts by weight is particularly preferred. More preferably, it is in the range of 0.2 to 1.0 part by weight.

Examples of the lubricant or heat stabilizer include chelators such as fatty acid-based lubricants, fatty acid amide-based lubricants, ester-based lubricants, polyethylene wax, liquid paraffin, and organic phosphite compounds generally used for agricultural films, and phenols. And β-diketone compounds. As the β-diketone compound, dibenzoylmethane,
Preferred are methoxybenzoyl benzoylmethane, chlorobenzoyl benzoylmethane, palmitylbenzoylmethane and the like. The amount of these lubricants and heat stabilizers is
In the range from 0.01 to 2.0 parts by weight, in particular from 0.04 to 1.
0 parts by weight is preferred.

The ultraviolet absorber may be any one which is usually blended in an agricultural vinyl chloride film, and includes various ultraviolet absorbers such as benzotriazole, benzophenone, salicylate, hydroquinone, and cyanoacrylate. Can be For example, Japanese Patent Publication No. 62-38
No. 143, column 27, line 9 to column 9, line 34; and JP-B-62-53543, column 7, lines 13 to 36. Agents and benzophenone ultraviolet absorbers are preferred. Specifically, the following are mentioned.

2- (2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5), which are benzotriazole type ultraviolet absorbers
-Methylphenyl) -5-carboxylic acid butyl ester benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) -5,6-dichlorobenzotriazole, 2- (2'-hydroxy-5'-methyl Phenyl)
-5-ethylsulfonebenzotriazole, 2- (2 ′
-Hydroxy-5'-t-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5 '
-T-butylphenyl) benzotriazole, 2-
(2'-hydroxy-5'-aminophenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dimethylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-dimethyl Phenyl) -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-ethylsulfonebenzotriazole, 2- (2'-hydroxy-4'-
Octoxyphenyl) benzotriazole, 2- (2 ′
-Hydroxy-5'-methoxyphenyl) -5-methylbenzotriazole, 2- (2'-hydroxy-5'-
Methylphenyl) -5-carboxylate benzotriazole, 2- (2′-acetoxy-5′-methylphenyl) benzotriazole and the like.

A benzophenone-based 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, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfonebenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, , 2'-dihydroxy-4,4'-
Dimethoxybenzophenone, 2-hydroxy-5-chlorobenzophenone, bis- (2-methoxy-4-hydroxy-5-benzoylphenyl) methane and the like.

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

As the light stabilizer, there can be used various compounds usually compounded in agricultural films. For example, hindered amine compounds can be used. Specifically, JP-A-6-155680, No. 5 To 19 pages. These light stabilizers may be used alone or in combination of two or more. The amount is
0.05 to 5.0 per 100 parts by weight of vinyl chloride resin
The range of parts by weight, particularly 0.1 to 2 parts by weight, is preferred.

As the metal salt of organic phosphoric acid, salts of zinc, calcium, barium, magnesium, cobalt or strontium with various organic phosphoric acids are used. Specifically, JP-A-2-30529, page 9, line 9 to line 11
The organic phosphoric acid metal salts described on the last line of the page can be mentioned. These metal organic phosphates may be used alone or in combination of two or more. The compounding amount is in the range of 0.05 to 5.0 parts by weight, particularly preferably 0.1 to 2 parts by weight, per 100 parts by weight of the vinyl chloride resin.

In the present invention, an inorganic substance that absorbs in the infrared region may be blended for the purpose of improving heat retention. Specifically, the following are mentioned. Silicon oxide (silica), magnesium hydroxide, aluminum hydroxide, magnesium silicate (talc), magnesium carbonate, aluminum oxide, feldspar, mica, calcium silicate, calcium carbonate, aluminum silicate, hydrotalcite as shown in the following formula (Water-containing or anhydrous-aluminum / magnesium basic carbonate); aluminum / zinc basic carbonate lithium carbonate-aluminum hydroxide inclusion compound and the like.

(I): M ²⁺ _(1-X) Al ³⁺ _X (OH ⁻ ) _2.
(A ₁ ^n-) in _x / n · mH ₂ O (wherein, M ²⁺ represents a divalent metal ion, A ^n-n-valent anion, respectively, x, m and n, 0 <x <
0.5, 0 ≦ m ≦ 2, 1 ≦ n ≦ 3, respectively. ) (II): Li ⁺ (Al ³⁺ ) ₂ (OH ⁻ ) _6. (A ₂ ^{n −} ) _{1 / n.}
mH ₂ O (wherein, A ^n- represents an anion of n valence, respectively, and m
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 (wherein 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 ( in _{1 + x) / n · mH} 2 O ( wherein, M ²⁺ is a divalent metal ion, A ^n-n-valent anion represents respectively , M, x and n are 0 ≦ m <
5, the conditions of 0.01 ≦ x <1, 1 ≦ n ≦ 3 are respectively satisfied. (V): mAl ₂ O ₃ · (n / p) M _{2 / p} O · X · kH ₂ O (where X represents a carbonate group, M represents an alkali metal or an alkaline earth metal, and p represents The valence of the metal M, where m, n and k are 0.3 ≦ m ≦ 1, 0.3 ≦ n ≦
2. The condition of 0.5 ≦ k ≦ 4 is satisfied. One or more of these inorganic substances can be added, and the compounding amount thereof is in the range of 0.5 to 10 parts by weight, particularly in the range of 2 to 10 parts by weight per 100 parts by weight of the vinyl chloride resin. preferable.

As the compound which can be used as an antioxidant, phenolic and sulfuric antioxidants can be used, and specifically, 2,6-di-butyl-4-methylphenol-
2,2'-methylenebis (6-tert-butyl-4-
Ethylphenol), dilaurylthiodipropionate and the like. These antioxidants can be used alone or in combination of two or more.

Compounds that can be used as a stabilizing aid include triphenyl phosphite, dioctyl phenyl phosphite, tris (nonylphenyl) phosphite, diphenyl indecyl phosphite, trilauryl trithio phosphite, diphenyl acid phosphite and the like. Can be given. These stabilizing aids can be used alone or in combination of two or more.

Examples of the antistatic agent include polyoxyethylene alkylamine, polyglycol ether, p-
And sodium styrenesulfonate. As the fungicide and the anti-algal agent, various compounds generally used in agricultural vinyl chloride films can be used.
Examples thereof include organic nitrogen compounds, and specific examples thereof include imidazole derivatives, anilide derivatives, urea derivatives, ammonium derivatives, triazine derivatives, and phthalimide derivatives. Examples of usable coloring agents include phthalocyanine blue, phthalocyanine green,
Hansa Yellow, Alizarin Lake, titanium oxide, zinc white, permanent red, quinacridone, carbon black and the like can be mentioned. These colorants can be used alone or in combination of two or more.

The above various resin additives can be selected in a range that does not deteriorate the properties of the film, usually in a range of 5 parts by weight or less based on 100 parts by weight of the vinyl chloride resin.
To blend the resin additives into the vinyl chloride resin, weigh each required amount, and use a ribbon blender, Banbury mixer,
What is necessary is just to use a super mixer and other conventionally known compounding machines and mixers.

The resin composition thus obtained can be 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 known method such as a calendering method or a solution casting method may be used. The thickness of the film is 0.03-
0.3 mm range, preferably 0.05-0.2 mm
It is preferable to set it in the range. If it is thinner than 0.03 mm,
The film is not strong enough to break easily, 0.3m
If the thickness is larger than m, the operations such as cutting and bonding are adversely affected.

3. Formation of fine unevenness In the agricultural film of the present invention, fine unevenness is formed on one or both surfaces of the vinyl chloride resin film obtained as described above by embossing or the like. Such fine unevenness may be provided on the entire surface of the film, or may be provided only on a part thereof, for example, only on a side portion (a range of a predetermined width from one end) of the film.

There is also a mode in which fine irregularities are provided uniformly on the entire surface, but a mode in which a pattern is provided, for example, vertical stripes, horizontal stripes, diagonal stripes, lattices, or polka dots Parts are formed at substantially constant intervals, and the other parts are non-fine uneven parts (smooth parts), and the formation ratio of the fine uneven parts is 10 to 90%, preferably 20 to 7
There is also an embodiment in which the content is set to 0%, which is preferable.

The fine unevenness is 500 to 600 n
It is preferable to set the size and thickness of the irregularities and the interval between the irregularities so that the average transmissivity of the straight light beam having a wavelength of m is 45% or less and the average transmissivity of all light beams is 75% or more. By setting as described above, the light transmission of the entire film becomes good, and the film becomes suitable for growing the crop in the house.
The surface roughness Rz (μ) of the uneven portion is 0.1 to 100
can be appropriately selected from the range of μ, preferably 1 to
30μ. On the other hand, the non-fine irregularities are 500 to 600 n
It is preferable that the average straight transmittance of light having a wavelength of m is 60% or more and the average transmittance of all light is 80% or more for growing crops in a house.

4. Acrylic Resin Coating In order to further improve durability and dust resistance, one side of the agricultural polyvinyl chloride resin film according to the present invention, particularly preferably, an acrylic It is preferable to form a system resin film. As the acrylic resin to be used, hydroxyalkyl (meth)
Acrylate 5 to 40% by weight, 1 or 2 per molecule
A polymer obtained by copolymerizing 0 to 20% by weight of an α, β-unsaturated carboxylic acid containing at least one carboxyl group and another vinyl monomer copolymerizable therewith is preferred.

Examples of the hydroxyalkyl (meth) acrylate 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, and 6-hydroxyhexyl methacrylate.

These hydroxyalkyl (meth) acrylate compounds make it easy for the resulting acrylic resin to be dissolved in an organic solvent, improve the adhesion between the acrylic resin and the base vinyl chloride resin film, and further improve the stain on the film surface. It is a component that greatly contributes to the action of suppressing the migration of the plasticizer that comes out. The ratio of the hydroxyalkyl (meth) acrylate in the acrylic resin is 5% by weight.
When the amount is less than the above, the effect of improving the solubility with the organic solvent, the adhesion to the base film and the durability cannot be sufficiently exhibited. On the other hand, when the amount is more than 40% by weight, the cost becomes high and the cost increases. The effect obtained is not great and is not preferred.

The α, β-unsaturated carboxylic acid having one or more carboxyl groups in the molecule includes acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, aconitic acid, fumaric acid, Crotonic acid, itaconic acid and the like. 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 use amount of these is preferably 0.5 to 20% by weight. If it is more than this, the property that the films adhere to each other when the film is moistened with moisture (the blocking property when wet) is undesirably enhanced.

Other vinyl monomers copolymerizable with the hydroxyalkyl (meth) acrylate and the α, β-unsaturated carboxylic acid include alkyl (meth) acrylate or a mixture thereof with alkenylbenzene. Is raised. Examples of the alkyl (meth) acrylate include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and the like. Decyl acrylate, methyl methacrylate, ethyl methacrylate, methacrylic acid
Examples thereof include n-propyl ester, isopropyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, and decyl methacrylate, and are generally acrylic having 1 to 20 carbon atoms in the alkyl group. Acid alkyl esters and / or alkyl esters of methacrylic acid having 1 to 20 carbon atoms in the alkyl group are used.

The alkenylbenzene used in the present invention includes, for example, styrene, α-methylstyrene, vinyltoluene and the like. When a monomer comprising a mixture of such an alkenylbenzene and an alkyl (meth) acrylate is used, it usually varies depending on the amount of the α, β-ethylenically unsaturated carboxylic acid to be used. Use ratio of alkyl acrylate of 10
% By weight or more.

In particular, the acrylic resin of the present invention comprises a monomer comprising a mixture of the above-mentioned alkyl (meth) acrylate and a mixture thereof with alkenylbenzene in an amount of from 40 to 60.
What contains by weight is preferable. When such an acrylic resin is subjected to a surface treatment on a base vinyl chloride resin film, another resin compatible with the acrylic resin can be mixed for the purpose of improving the adhesion to the film. As the other resin, a vinylidene fluoride resin, an acrylic resin having a perfluoroalkyl group in a side chain, a cellulose acetate butyrate resin, a silicone resin, and the like are particularly effective.

In order to polymerize the acrylic resin, a predetermined amount of each monomer is combined, charged together with an organic solvent into a polymerization vessel, a polymerization initiator and, if necessary, a molecular weight regulator are added, and the mixture is heated with stirring. Good.

The acrylic resin film formed on one side of the vinyl chloride resin film is preferably applied by dissolving the acrylic resin in the above-mentioned organic solvent. To form a coating of the acrylic resin on the surface of the vinyl chloride resin film, the acrylic resin is dissolved in an organic solvent, and spray coating, roll coating, gravure coating, reverse coating, and dip coating are performed. 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. Available drying methods include, for example, hot air drying, infrared drying, far infrared drying and the like. The drying temperature is preferably a temperature at which the organic solvent is scattered, that is, the boiling point of the organic solvent in which the acrylic resin is dissolved. The shorter the drying time, the better. Therefore, it is preferable to dry at a temperature equal to or higher than the boiling point of the organic solvent in the shortest possible time.

The thickness of the acrylic resin film 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. Agricultural vinyl chloride resin film according to the present invention, in actual use, when the coating is formed on only one side, the side provided with this coating is to be outside the house or tunnel It is good to extend.

[0051]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Examples 1 to 3 and Comparative Example 1 Preparation of Base Film (1) Production of Vinyl Chloride Resin Film Polyvinyl Chloride (degree of polymerization = 1500) 100 parts by weight Di-2-ethylhexyl phthalate 45 parts by weight Chlorinated polyethylene (composition shown in Table 1, Table 3 5 parts by weight of tricresyl phosphate 3 parts by weight of epoxy resin 1.5 parts by weight of barium-zinc composite liquid stabilizer 1.5 parts by weight of barium stearate 0.2 parts by weight 0.4 part by weight of zinc stearate Sorbitan laurate 1. A resin composition consisting of 5 parts by weight of 2'4-dihydroxybenzophenone 0.06 parts by weight was prepared and blended.

Each of the components was stirred and mixed with a super mixer for 10 minutes, and then kneaded on a mill roll heated to 180 ° C. to form a 0.10 mm-thick film on one side.
A satin embossing was performed to prepare a base film.

II. Acrylic resin II-1. Preparation of Acrylic Resin In a reactor equipped with a thermometer, a stirrer, a reflux condenser and a nozzle for adding raw materials, 70 parts by weight of methyl ethyl ketone, 30 parts by weight of toluene, 1.0 part by weight of benzoyl peroxide and shown in Table 2 100 parts by weight of the mixture of each monomer was charged, and while stirring under a nitrogen gas stream, 0.5 parts by weight of benzoyl peroxide was further added at 70 ° C. for 3 hours, and the reaction was continued at the same temperature for about 3 hours. Thus, an acrylic polymer was obtained.

II-2. Formation of Coating Acrylic polymer of the kind and amount shown in Table 2 was blended, and methyl ethyl ketone was added to this so that the solid content was 20% by weight, to obtain a coating composition. The coating composition was applied to one surface of the substrate film prepared by the above method using a # 5 bar coater. The applied film was kept in an oven at 130 ° C. for 1 minute to evaporate the solvent. The amount of coating on each of the obtained films was about 3 g / m
^{Was 2} .

III. Evaluation of Film The performance of the film was evaluated by the following method, and the results are shown in Table 4. (1) Low-temperature physical properties Impact strength: The films obtained in Examples and Comparative Examples were 10c
Prepare 9 samples of m × 10cm, JIS B-7
The thickness at the center of the sample is measured with a dial gauge specified in 503. The sample was measured in a room at −10 ° C. using a puncture manufactured by Toyo Seiki Co., Ltd. Impact strength = measured value (impact value) / measured thickness x nominal thickness

(2) Outdoor extension test Various films were installed on a roof-type house (3 m wide, 5 m deep, 1.5 m high,
(The roof slope was 30 degrees), and the coated surface was covered with the house side, and a one-year expansion test was conducted from March 1998 to February 2011. The stretched film was evaluated for the residual elongation after weathering of the film, the impact strength at low temperature of the film, and the brittle fracture rate by the following methods.

I) Dustproofness The value calculated by the following equation was judged according to the following evaluation criteria. (Straight ray transmittance of the film recovered over time after stretching *) / (straight ray transmittance before stretching *) × 100 * Straight ray transmittance at a wavelength of 555 nm (using Hitachi, model EPS-2U)・ ・ Light transmittance of 90% or more before expansion.・ ・ ・: The light transmittance after expansion is in the range of 70 to 89% before expansion. Δ: The light transmittance after expansion is in the range of 50 to 69% before expansion. X: Light transmittance after expansion is less than 50% before expansion.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

[Table 3]

[0062]

[Table 4]

[0063]

As described above, the present invention has the following effects, and its agricultural utility value is extremely large. (1) The vinyl chloride resin film for agriculture of the present invention can reduce the adhesion between films without deteriorating the light transmittance. (2) The agricultural polyvinyl chloride resin film of the present invention has excellent physical properties at low temperatures, and is excellent in resistance to tearing due to stretching and tearing due to external force (wind, snow, hail, arare, etc.) after stretching. ing. (3) The vinyl chloride resin film for agricultural use of the present invention has a small degree of reduction in dustproofness even when it is spread outdoors. Incidentally, in the vinyl chloride resin film for agricultural use according to the present invention, the internal stress relaxation effect and the increase of molecular entanglement by mixing a specific chlorinated polyethylene can improve the physical properties at low temperatures. As described above, the agricultural vinyl chloride resin film of the present invention is excellent in low-temperature properties and physical properties after weathering.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Murakami Izuka-cho, Iwatsuka-cho, Nakamura-ku, Nagoya City, Aichi Prefecture Mitsubishi Chemical MKV Co., Ltd. Address Mitsubishi Chemical MKV Corporation Nagoya Office F-term (reference) 2B024 DA01 DA03 DB01 EA01 2B029 EC02 EC04 EC09 EC12 EC20 4F071 AA24 AA79 AA88 AE04 AF30Y AG12 AG22 AH01 BA01 BB04 BC01 BC08

Claims (6)

[Claims] 1. Agricultural chloride characterized in that fine irregularities are formed on one or both sides of a vinyl chloride resin film mixed with a vinyl chloride resin (A), a chlorinated polyethylene (B) and a plasticizer. Vinyl resin film. 2. In the vinyl chloride resin film,
2. The vinyl chloride resin film for agricultural use according to claim 1, wherein the average linear transmittance of the light having a wavelength of 500 to 600 nm is 45% or less, and the total transmittance is 75% or more. 3. The vinyl chloride-based resin film has vertical irregularities, horizontal stripes, diagonal stripes, lattices, or polka-dot fine irregularities formed at substantially constant intervals on the entire surface of the film. The vinyl chloride resin film for agricultural use according to claim 1 or 2, wherein the fine unevenness is formed such that the formation ratio of the fine unevenness is 10 to 90%. 4. In the vinyl chloride resin film,
The fine irregularities have a straight-line average transmittance of 45% or less at a wavelength of 500 to 600 nm, a total average transmittance of 75% or more,
The agricultural vinyl chloride system according to any one of claims 1 to 3, wherein the non-fine irregularities have a linear light transmittance of 60% or more and a total light average transmittance of 80% or more at a wavelength of 500 to 600 nm. Resin film. 5. The chlorinated polyethylene having a chlorine content of 15
~ 50% by weight, melt index 0.5 ~ 150g /
The vinyl chloride resin film for agricultural use according to any one of claims 1 to 4, wherein the crystallinity is 0 to 30% for 10 minutes. 6. The vinyl chloride resin film according to claim 1, wherein an acrylic resin film is formed on one or both surfaces of the vinyl chloride film.