JP2000062107A - Agricultural vinyl chloride resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agricultural vinyl chloride resin film having excellent impact resistance at low temperatures and excellent resistance to break. SOLUTION: A vinyl chloride film is composed by mixing 30-60 pts.wt. plasticizer and 0.5-20 pts.wt. particles of acrylic elastic body composed of a polymer having an alkyl methacrylate as a main component, wherein an average particle diameter thereof is 100-300 μm and partial partition efficiency of D75/D25 is 1.052.5, to 100 pts.wt. vinyl chloride resin having an average polymerization degree of 1000-2500. A film, which is composed of 40-70 wt.% methyl methacrylate, 5-30 wt.% hydroxyalkyl(methacrylate)compound, 0-20 wt.% α,βunsaturated carboxylic acid containing one or more carboxyl groups in a molecule and an acrylic resin obtained by copolymerizing other vinyl monomers copolymerizable therewith, is formed on one or both sides of the vinyl chloride film.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an agricultural vinyl chloride resin film. More specifically, it has good workability, has excellent impact strength at low temperatures, and has poor physical properties after outdoor exposure, against undesired phenomena such as tearing due to external force (wind, snow, hail, arale, etc.) after expansion. Significantly less of the
Further, the present invention relates to a vinyl chloride resin film for agriculture, which has good transparency and has little deterioration in dustproof property after outdoor exposure.

[0002]

2. Description of the Related Art In recent years, farmers cultivating useful plants have widely adopted a method of accelerating or suppressing cultivation of useful plants in a house (greenhouse) or a tunnel for the purpose of improving profitability. Became. Polyethylene film, ethylene-vinyl acetate copolymer film, polyester film, polycarbonate film, hard and soft vinyl chloride resin film, glass and the like are used as the covering material for the house (greenhouse) or tunnel. Among them, the soft vinyl chloride resin film is the best in terms of light transmittance, heat retention, mechanical strength, durability and workability as compared with other synthetic resin films,
Widely used.

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 for improving physical properties such as elongation and impact resistance in cold regions,
The following methods have been proposed for increasing the amount of plasticizer in a vinyl chloride resin film for agriculture, or adding a plasticizer such as a cold-resistant plasticizer.

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.).

Further, as an impact modifier, methyl methacrylate-butadiene-styrene copolymer (MBS resin)
(JP-A-6-322209), acrylonitrile-butadiene-styrene copolymer (ABS resin), styrene-
Although butadiene rubber (SBR) and the like have been proposed, these impact modifiers have improved impact strength, but the double bond contained in the molecule is active against light, ultraviolet rays or heat. Therefore, the vinyl chloride resin film obtained from the resin containing them is weather resistant (browning).
However, it is proposed to add an ultraviolet absorber, an antioxidant, a light stabilizer, etc.
Satisfactory physical properties are not obtained. On the other hand, the vinyl chloride resin film used for agriculture has a drawback that the dust-proof property on the outside of the house or the tunnel is lowered due to the influence of the area and place where the vinyl chloride resin is used.

[0006]

Under the circumstances, the present inventors have improved the impact strength at low temperature, and further,
It was an object to provide a vinyl chloride resin film for agricultural use, in which physical properties are not significantly deteriorated by outdoor exposure (after lapse of time).
Further, it is excellent in workability during film forming, does not break even when it is spread in a cold area, and does not break even if it is caused by external forces such as wind, snow, hail, and arale after it is spread outdoors. or,
Diligently studied with the aim of providing a vinyl chloride resin film for agriculture that does not cause stickiness or sagging (improvement of elastic modulus) at high temperatures such as in summer, and has little deterioration in dust resistance even after aging. As a result, the present invention has been completed.

[0007]

However, the gist of the present invention is that the plasticizer [B] 30 to 100 parts by weight of the vinyl chloride resin [A] having an average degree of polymerization of 1,000 or more and 2500 or less is used. 60 parts by weight, average particle size 100 to 300
μm, 25% separated particle size (D2
5) and 75% separated particle size (D75) ratio (D75 / D
Acrylic elastic particles [C], which is a polymer containing 25 to 1.05 to 2.5 and an alkyl methacrylate as a main component.
Methyl methacrylate 40-70 on one or both sides of a vinyl chloride resin film mixed with 0.5-20 parts by weight
% By weight, 5 to 30% by weight of hydroxyalkyl (methacrylate) compound, 0 to 20% by weight of α, β unsaturated carboxylic acid containing one or more carboxyl groups in the molecule, and others copolymerizable therewith A vinyl chloride resin film for agriculture, which is formed with a film of an acrylic resin [D] obtained by copolymerizing with the vinyl monomer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. 1. Vinyl chloride-based resin [A] In the present invention, the vinyl chloride-based 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, a vinyl chloride resin having an average degree of polymerization of 1,000 or more and 2,500 or less is used, but two kinds of vinyl chloride resins having different average degrees of polymerization may be mixed. As this mixing method, a method of mixing two kinds of resins at the time of film forming is generally used. However, when the polymerization conditions of vinyl chloride resin are controlled, two kinds of resins having apparently different average degrees of polymerization are mixed. It may be a method that has been done.

2. Plasticizer [B] In order to impart flexibility, the vinyl chloride resin film serving as the above-mentioned substrate has 3 parts by weight with respect to 100 parts by weight of this resin.
0 to 60 parts by weight, preferably 40 to 55 parts by weight of a plasticizer is blended. If the amount is less than 30 parts by weight, the flexibility at low temperature is poor and sufficient low temperature physical properties cannot be obtained. Also,
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 the plasticizer 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.

3. Acrylic elastic body particles [C] The acrylic elastic body of the present invention is obtained by a sequential multi-stage polymerization method containing an alkyl methacrylate monomer as a main component and another vinyl monomer copolymerizable with the alkyl methacrylate monomer. Yes, these copolymers form a multilayer structure polymer. As the multilayer structure polymer, a three-stage polymer (three-layer structure) or a four-stage polymer (4
Layer structure) is preferred.

The alkyl methacrylate monomer is preferably an alkyl methacrylate monomer having an alkyl group having 8 or less carbon atoms. Specific examples thereof include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, cyclohexyl methacrylate and 2-ethylhexyl methacrylate.

Other monomers copolymerizable with the alkyl methacrylate include ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate and decyl. C1 to C16 of acrylic acid such as acrylate
Alkyl esters of: ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate,
C1-C16 alkyl esters of methacrylic acid such as n-butyl methacrylate, i-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, and decyl methacrylate: styrene, acrylonitrile, methacrylonitrile and the like. These vinyl monomer monomers copolymerizable with methyl methacrylate may be copolymerized by combining one kind or several kinds.

The amount of the acrylic elastic particles to be mixed with the vinyl chloride resin should be 0.5 to 20 parts by weight. If it is less than 0.5 parts by weight, sufficient impact strength cannot be obtained, and if it is too large, mechanical properties are rather deteriorated, which is not preferable, and 10 parts by weight or less is preferable. Even within the above range, 1.0 to 8 parts by weight is particularly suitable. Furthermore, the average particle diameter of the acrylic elastic particles is 100 to 300.
The μm range is required. If it is smaller than 100 μm, sufficient physical strength cannot be obtained, and if it is larger than 300 μm, sufficient transparency cannot be obtained due to irregular reflection of light, which is not preferable. Within the above range, the range of 150 to 250 μm is particularly preferable.

The ratio (D75 / D25) of the 25% separated particle diameter (D25) to the 75% partial separation efficiency (D75) in the partial separation efficiency of the acrylic elastic particles is 1.
Must be 05-2.5. A range of more than 2.5 is not preferable because sufficient impact strength and transparency cannot be obtained. Within the above range, a particularly preferable range is
1.1 to 2.3 are particularly preferable.

Acrylic elastic particles are the same as those of the above monomers.
A predetermined amount of at least one kind is combined and charged into a polymerization vessel, a polymerization initiator, an emulsifier, and a graft crossing agent are added if necessary, and the emulsion polymerization is carried out by a usual multistage polymerization method. This sequential multi-stage polymerization method is carried out under such conditions that the monomers continuously added to the aqueous dispersion or emulsion are successively sheet-polymerized on the emulsion particles formed by the previously added monomers. . The polymerization of each layer is carried out after the previous polymerization is completed, followed by dropwise polymerization, coagulation by a normal salting-out method, and drying. The polymerization initiator may be any one usually used in emulsion polymerization, and examples thereof include water-soluble persulfates and redox initiators. As the emulsifier, an anionic surfactant is preferred, but any emulsifier usually used in emulsion polymerization may be used.

4. Acrylic Copolymer It is preferable to incorporate an acrylic copolymer in the agricultural vinyl chloride resin film of the present invention from the viewpoint of processability. As the acrylic copolymer, those obtained by copolymerizing a methyl methacrylate monomer as a main monomer and a methyl methacrylate monomer and a copolymerizable vinyl monomer monomer are preferable.

The copolymerization ratio is (A) 60 to 100% by weight of methyl methacrylate and (B) 0 to 0 of a vinyl monomer monomer copolymerizable with a methyl methacrylate monomer.
It is preferably 40 parts by weight. When the content of the methyl methacrylate monomer is less than 60% by weight, the compatibility between the acrylic copolymer and the vinyl chloride resin is poor and the film appearance is inferior, which is not preferable.

Vinyl monomers copolymerizable with methyl methacrylate include ethyl acrylate and n-
Propyl acrylate, i-propyl acrylate, n
-C1 of acrylic acid such as butyl acrylate, i-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, etc.
To C16 alkyl esters: C1 to C16 of methacrylic acid such as ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate and the like. Alkyl esters of: styrene, acrylonitrile, methacrylonitrile and the like. These vinyl monomer monomers copolymerizable with methyl methacrylate may be copolymerized by combining one kind or several kinds.

The amount of the acrylic copolymer to be blended with the vinyl chloride resin is preferably 0.1 to 10 parts by weight. If the amount is less than 0.1 part by weight, the workability is not improved and 1
When the amount is more than 0 parts by weight, the workability and the physical properties are not proportionally improved, which is not preferable. Within the above range, 0.5 to 5 parts by weight is particularly preferable. The acrylic copolymer is a combination of two or more of the above monomers in a predetermined amount, charged into a polymerization vessel together with an organic solvent or water, a polymerization initiator,
It can be obtained by adding a molecular weight modifier as needed and polymerizing by heating while stirring. For the polymerization, known methods such as suspension polymerization method, solution polymerization method and emulsion polymerization method are adopted.

5. β-Diketone Compound The β-diketone compound of the present invention is preferably blended with a β-diketone compound from the viewpoint of preventing discoloration due to heat during processing. The β-diketone compound may be any one usually blended in an agricultural vinyl chloride film, and examples thereof include β-diketone and dehydroacetic acid. As the β-diketone, a compound containing one or more structural units represented by the following general formula [I] in one molecule is suitable.

[0023]

[Chemical 1]

(In the formula [I], R1 and R2 have 1 carbon atoms.
4 represents an alkyl group or a phenyl group. Examples of the compounds contained in the general formula [I] include acetylacetone, benzoylacetone, benzoylpropionylmethane, dibenzoylmethane and the like. β-
If the amount of the diketone compound to be added to the vinyl chloride resin film is too small, discoloration due to heat during molding occurs, which is not preferable. Even if the amount is too large, the coloring resistance of the film is proportional to the amount added. There is no improvement. A preferable blending amount is 0. 0 with respect to 100 parts by weight of the vinyl chloride resin.
It is in the range of 005 to 0.10 parts by weight.

6. Light Stabilizer It is preferable to add a light stabilizer to the agricultural vinyl chloride resin film of the present invention from the viewpoint of film forming property and outdoor spreadability. The light stabilizer may be any one usually added to a vinyl chloride film for agriculture, and examples thereof include hindered amine type and metal complex salt type. A hindered amine light stabilizer is particularly preferable. Specific examples include the following. As a hindered amine light stabilizer,
A compound containing at least one structural unit represented by the following general formula [II] or [III] in one molecule is suitable.

[0026]

[Chemical 2]

(In the formula [II], R1 to R4 have 1 carbon atoms.
~ 4 alkyl group, R5 represents hydrogen or an alkyl group having 1 to 4 carbon atoms. )

[0028]

[Chemical 3]

(In the formula [III], R1 to R4 represent an alkyl group having 1 to 4 carbon atoms, and R5 represents hydrogen or an alkyl group having 1 to 4 carbon atoms.) For example, a hindered amine system represented by the general formula [IV]. The compounds are typical.

[0030]

[Chemical 4]

(Wherein R is phosphorus or a mono-to-tetraacyl group derived from a mono- or tetravalent carboxylic acid, and n is 1 to 4).
Indicates the integers of. ) Specific examples of those contained in the above general formula [IV] are shown in, for example, Japanese Patent Publication No. 63-51458.
4-Cyclohexinoyloxy-2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6
6-tetramethylpiperidine, 4- (o-chlorobenzoyloxy) -2,2,6,6-tetramethylpiperidine and the like can be mentioned.

The metal complex salt light stabilizer is preferably a metal such as nickel or cobalt. Specific examples include the following. Nickel metal complex: Nickel [2
2'thiobis (4-tertiaryoctyl) phenolate] normal butylamine, nickel dibutyldithiocarbamate, nickel bis [oethyl 3,5 (ditertiarybutyl 4-hydroxybenzyl)] phosphate,
Nickel bis (octyl phenyl sulfide) etc. are mentioned. Cobalt metal complex: cobalt dicyclohexyl dithiophosphate, [1-phenyl, 3-methyl,
4-decanoyl, pyrazolate (5) 2] nickel and the like can be mentioned.

If the amount of the light stabilizer to be added to the vinyl chloride resin film is too small, the weather resistance of the film will not be sufficiently excellent, and it is not preferable. There is no proportional improvement, and the film surface blows out. A preferred blending amount is 0.1 to 100 parts by weight of vinyl chloride resin.
It is in the range of 1.0 part by weight.

It is preferable to use an ultraviolet absorber and a light stabilizer in combination with the agricultural vinyl chloride resin film of the present invention from the viewpoint of film forming property and outdoor spreading property. The UV absorber may be any UV absorber which is usually blended with an agricultural vinyl chloride film, and examples thereof include various UV absorbers such as benzotriazole-based, benzophenone-based, salicylate-based, hydroquinone-based, and cyanoacrylate-based. Particularly, benzotriazole-based UV absorbers and benzophenone-based UV absorbers are preferable. Specific examples include the following.

Benzophenone type UV absorbers; 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, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-5-chlorobenzophenone, Bis- (2-methoxy-4-hydroxy-5
-Benzoylphenyl) methane.

Benzotriazole type ultraviolet absorber; 2-
(2'-hydroxyphenyl) benzotriazole, 2
-(2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) -5-carboxylic acid butyl ester benzotriazole, 2- (2'-hydroxy-5 ' -Methylphenyl) -5,6-dichlorobenzotriazole, 2-
(2'-Hydroxy-5'-methylphenyl) -5-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 ', 5'-di-t-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 -Carboxylic acid benzotriazole, butyl ester, 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-carboxylic acid ester benzotriazole, 2
-(2'-acetoxy-methylphenyl) benzotriazole.

The amount of the above ultraviolet absorber to be added to the base film is 100 parts by weight of the base vinyl chloride resin.
The range of 0.02 to 8 parts by weight is preferable. When the amount is less than 0.02 part by weight, the weather resistance of the vinyl chloride resin film for agriculture is not sufficiently excellent, which is not preferable. On the other hand, if the amount is more than 8 parts by weight, there is a problem that the film may be spouted onto the film surface together with other additives when the film is used, which is not preferable. Of the above range, 0.
A range of 1 to 3 parts by weight is preferable.

7. Organic Phosphate Ester or Organic Phosphate Metal Salt In the agricultural vinyl chloride resin film of the present invention, it is preferable that the vinyl chloride resin is blended with an organic phosphate ester or an organic phosphate metal salt. Examples of the organic phosphate ester include triisopropylphenyl phosphate, isodecyldiphenylphosphate, tris (isopropylphenyl) phosphate, tributylphosphate,
Triethyl phosphate, trioctyl phosphate,
There are tributoxyethyl phosphate, triphenyl phosphate, octyldiphenyl phosphate, trixylenyl phosphate and the like, and among them, tricresyl phosphate and trixylenyl phosphate are particularly preferable.

The above-mentioned organic phosphoric acid esters may be used alone or as a composite. For example, a composite of an organic phosphoric acid ester and an organic phosphorous acid ester can be mentioned, and the organic phosphoric acid ester also includes a phosphonate compound such as diphenyl phosphate. The organic phosphoric acid metal salt has a general formula [V] or [VI]

[0040]

[Chemical 5]

[0041]

[Chemical 6]

(In the formula, M means zinc, calcium, barium, magnesium, cobalt or strontium. Further, R1, R2 and R3 are each alkyl,
It means an aryl group, an arylalkyl group, an alkylaryl group, or an alkyl group having an ether bond. ). Examples of the alkyl group represented by R1, R2 and R3 include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, sec-butyl, amine, neopentyl, isoamyl, hexyl,
Isohexyl, heptyl, octyl, isooctyl, 2
-Ethylhexyl, decyl, isodecyl, lauryl, tridecyl, C12-C13 mixed alkyl, stearyl,
Examples thereof include cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl and 4-methylcyclohexyl groups.

Examples of aryl groups include phenyl and naphthyl groups. Examples of the arylalkyl group include benzyl, β-phenylethyl, α-phenylpropyl and β-phenylpropyl groups. Examples of alkylaryl groups include tolyl,
Xylyl, ethylphenyl, butylphenyl, tertiary butylphenyl, octylphenyl, isooctylphenyl, tertiary octylphenyl, nonylphenyl, 2,4-
A di-tertiary butyl phenyl group etc. are mentioned.

Examples of the alkyl group having an ether bond include furfuryl, tetrahydrofurfuryl, 5-methylfurfuryl and α-methylfurfuryl groups, or methyl-, ethyl-, isopropyl-, butyl-, isobutyl-, hexyl-. , Cyclohexyl-, phenylcellosolve residues; methyl-, ethyl-, isopropyl-, butyl-, isobutylcarbitol residues; triethylene glycol monomethyl ether, -monoethyl ether, -monobutyl ether residues; glycerin 1,2-dimethyl ether , -Monoethyl ether, -monobutyl ether residue; glycerin 1,2-dimethyl ether, -1,3
-Diethyl ether, -1-ethyl-2-propyl ether residue; nonylphenoxypolyethoxyethyl, lauroxypolyethoxyethyl residue and the like.

Further, the metal represented by M is particularly preferably zinc, calcium and barium. These organic phosphoric acid esters or organic phosphoric acid metal salts may be used alone or in combination of two or more. In the agricultural film of the present invention, it is preferable to use an organic phosphoric acid ester and an organic phosphoric acid metal salt in combination from the viewpoints of film forming property and outdoor spreading property.

The amount of the organic phosphoric acid ester or the organic phosphoric acid metal salt compounded is within the range of 0.1 to 15 parts by weight, preferably 0.2 to 1 part by weight, relative to 100 parts by weight of the vinyl chloride resin.
It is selected within the range of 0 parts by weight. If the amount is less than 0.1 parts by weight, the weather resistance and dust resistance of the soft vinyl chloride resin film will not be improved. If the blending amount is more than 15 parts by weight, the transparency of the film becomes extremely poor, which is not preferable. Within the above range, the range of 0.2 to 8 parts by weight is particularly preferable.

Of course, the vinyl chloride resin is necessary in addition to the plasticizer, acrylic copolymer, anti-coloring agent, light stabilizer, organic phosphate ester or metal salt of organic phosphate, and ultraviolet absorber. Depending on the known resin additives that are usually blended with the synthetic resin for molding, for example, lubricants, heat stabilizers, antioxidants, stabilizing aids, antistatic agents, antifog agents, antifungal agents,
An algae preventive, an inorganic feller, a coloring agent and the like can be added.

Lubricants which can be blended in the film according to the present invention include polyethylene wax, bisamide type compounds, liquid paraffin and the like, and antioxidants include organic phosphite compounds and the like. Also,
Examples of the heat stabilizer include β-diketone compounds. The above various resin additives can be used alone or in combination of several kinds. The addition amount of the above various resin additives is in a range not deteriorating the properties of the film, usually 1 part by weight with respect to 100 parts by weight of the vinyl chloride resin of the substrate.
It can be selected within the range of 0 parts by weight or less.

To add the above-mentioned plasticizer, light stabilizer, ultraviolet absorber, organic phosphoric acid ester or organic phosphoric acid metal salt, and other resin additives to the vinyl chloride resin as the base of the film, Weigh the required amount, ribbon blender,
A Banbury mixer, super mixer, or other conventionally known compounding machine or mixing machine 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 (T-die method,
(Including inflation method), calender molding method, solution casting method and the like.

8. Coating Component 8-1 Acrylic Resin [D] The acrylic resin used in the present invention is 40 to 70% by weight of methyl methacrylate, 5 to 30% by weight of a hydroxyalkyl (methacrylate) compound, and one or two in the molecule. It is a copolymer obtained by copolymerizing a monomer mixture containing 0 to 20% by weight of the above-mentioned α and β unsaturated carboxylic acids containing a carboxyl group, and another vinyl-based monomer copolymerizable therewith. . The methyl methacrylate is 70
If it is more than 40% by weight, the physical properties at a sufficiently low temperature cannot be maintained, while if it is less than 40% by weight, the dustproof effect cannot be exerted, which is not preferable.

Hydroxyalkyl (meth) acrylate monomers 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-hydroxybutyl methacrylate, 2-hydroxypentyl acrylate, 2-hydroxypentyl methacrylate, 6-hydroxyhexyl acrylate,
6-hydroxyhexyl methacrylate and the like can be mentioned.

When the proportion of the hydroxyalkyl (meth) acrylate in the acrylic resin is less than 4% by weight, the solubility with an organic solvent cannot be sufficiently exhibited, while it is more than 30% by weight. In this case, the effect obtained is not so large as the cost increase, which is not preferable. Α containing one or more carboxyl groups in the molecule,
Examples of β-unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, aconitic acid, fumaric acid and crotonic acid.

Examples of the above-mentioned methyl methacrylate monomer, hydroxyalkyl (meth) acrylate monomer and other vinyl monomers copolymerizable with α, β-unsaturated carboxylic acid include, for example, methyl acrylate, ethyl acrylate and n-propyl. Alkyl acrylate having an alkyl group side chain of 1 to 8 such as acrylate, isopropyl acrylate, and 2-ethylhexyl acrylate; 2 to 8 side chain of an alkyl group such as ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, and 2-ethylhexyl methacrylate. Alkyl methacrylate; α, β-ethylenically unsaturated phosphonic acids such as ethylene sulfonic acid; hydroxyl group-containing vinyl monomers such as hydroxyethyl of acrylic acid or methacrylic acid; acrylonitriles; There are (meth) glycidyl esters of acrylic acid, and the like; Ruamaido such. These monomers may be used alone or in combination of two or more.

8-2 A predetermined amount of the polymerization monomer of the acrylic polymer [D] is blended, charged into a polymerization vessel together with an organic solvent, a polymerization initiator and, if necessary, a molecular weight modifier are added and stirred. While heating, polymerize. For the polymerization, generally known methods such as suspension polymerization method and solution polymerization method are adopted. At this time, as the polymerization initiator that can be used, α, α-
Radical generating catalysts such as azobisisobutyronitrile, benzoyl peroxide, cumene hydroperoxide and the like can be mentioned, and examples of the molecular weight regulator include butyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, β-mercaptoethanol and the like. To be

The organic solvent used for the polymerization is methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-.
Alcohols such as butanol, n-amyl alcohol, isoamyl alcohol, tert-amyl alcohol, n-hexyl alcohol and cyclohexanol; aromatic hydrocarbons such as benzene, toluene and xylene; acetic acid esters such as ethyl acetate and butyl acetate Acetone, methyl ethyl ketone, methyl-n-propyl ketone, 2-hexanone, 3-hexanone, di-n-propyl ketone,
There are ketones such as di-n-amyl ketone and cyclohexanone; tetrahydrofuran and the like, and these can be used alone or in combination of two or more.

In the above coating composition, in addition to these components,
Auxiliary components such as antioxidants, neutralizing agents, ultraviolet absorbers, light stabilizers, antistatic agents, pigments, dyes, foaming agents, lubricants and the like can be added. It can be used after being dispersed and / or dissolved in an organic solvent. Examples of the organic solvent include heptane and cyclohexane as aliphatic hydrocarbons; benzene, toluene, xylene and the like as aromatic hydrocarbons;
Methanol, ethanol, isopropyl alcohol, polyoxyethylene glycol, etc. as alcohols; chloroform, tetrachlorohydrocarbon, chlorobenzene, etc. as halogenated hydrocarbons; methyl acetate, allyl acetate, ethyl stearate, etc. as esters; trimethylamine as amines, Diphenylamine, hexamethylenediamine, etc .; Other dimethylformamide,
There are dimethylacetamide, dioxane, diethyl ether, diethylenedithioglycol, diacetone alcohol, benzonitrile, dimethyl sulfoxide and the like, which can be used alone or in combination of two or more kinds.

To form a dustproof coating on the surface of the substrate film, a solution or dispersion of each composition is applied by a doctor blade coating method, a gravure roll coating method, an eye knife coating method, a reverse roll coating method, a dip coating method. ,
A coating method such as a curtain roll coating method, a spray coating method, or a rod coating method is used. When the coating composition is formed as a single coating without being in a solution state,
A coextrusion method, an extrusion coating method, an extrusion laminating method, and a laminating method are used. As a film forming method,
The method of drying the solvent when using the coating method includes, for example, a natural drying method, a hot air drying method, an infrared drying method, a far infrared drying method, etc., but the hot air drying method is advantageous in consideration of the drying speed and safety. Is. The temperature condition in this case is 50 ° C to 20 ° C.
The temperature is preferably set to 0 ° C. and the time is preferably selected from 10 seconds to 15 minutes.

In the present invention, the thickness of the coating film formed on the surface of the base film is preferably 1/10 or less of that of the base film. The thickness of the coating is 1/1 of that of the base film
When it is greater than 0, 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.

Before applying the above coating composition, the surface of the soft vinyl chloride resin film is washed with alcohol or water in advance, plasma discharge treatment or corona discharge treatment is performed, and other paint or primer is used. May be subjected to a pretreatment such as undercoating. When the vinyl chloride resin film for agriculture according to the present invention is actually used for agriculture, when the coating is formed on only one side, the side provided with this coating should be the outside of the house or tunnel. To use.

[0060]

EXAMPLES The present invention will be described in detail below based on examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. I. Preparation of base film Examples 1 to 3, Comparative Examples 1 to 6 Vinyl chloride resin (average degree of polymerization 1500) 100 parts by weight Di-2-ethylhexyl phthalate (DOP) 45 parts by weight Acrylic elastic particles (three-stage polymer) (Composition shown in Table 1) Epoxy resin 3 parts by weight Barium-zinc based composite liquid stabilizer 1.5 parts by weight Barium stearate 0.2 parts by weight Zinc stearate 0.4 parts by weight Sorbitan laurate 1.5 parts by weight An acrylic copolymer (“Metablen P-570A” manufactured by Mitsubishi Rayon Co., Ltd.) (2.0 parts by weight) was prepared, and the β-diketone compound and organic phosphorus in the types and amounts shown in Table 3 were prepared. An acid ester or an organic phosphoric acid metal salt, a light stabilizer and an ultraviolet absorber were blended.

Each composition was stirred and mixed with a super mixer for 10 minutes and then kneaded on a mill roll heated to 180 ° C. to prepare a base film having a thickness of 0.10 mm.
However, no β-diketone compound was added to Comparative Examples 1 and 5. Further, no light stabilizer was added to Comparative Examples 1 and 4, and no ultraviolet absorber was added to Comparative Examples 1 and 3. Further, Comparative Examples 1 and 2 did not contain an organic phosphate ester or an organic phosphate metal salt.

Comparative Example 7 Vinyl Chloride Resin (Average Polymerization Degree 1500) 100 parts by weight Di-2-ethylhexyl phthalate (DOP) 20 parts by weight Acrylic elastic particles (three-stage polymer) (composition shown in Table 1) Epoxy Resin 3 parts by weight Barium-zinc based composite liquid stabilizer 1.5 parts by weight Barium stearate 0.2 parts by weight Zinc stearate 0.4 parts by weight Sorbitan laurate 1.5 parts by weight Acrylic copolymer (Mitsubishi Rayon ( "METABRENE P-570A" manufactured by K.K.) was prepared, and a resin composition consisting of 2.0 parts by weight was prepared, and a base film having a thickness of 0.10 mm was prepared using the same additives as in Examples 1 to 3 and the same processing method. It was adjusted.

II. Into a reactor equipped with a thermometer for controlling the acrylic polymer [D], 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 the second Charge 100 parts by weight of the mixture of each monomer shown in the table,
While stirring under a stream of nitrogen gas, 0.5 part by weight of benzoyl peroxide was further added at 70 ° C. for 3 hours, and the reaction was continued for about 3 hours at the same temperature to obtain an acrylic polymer.

III. Formation of coating film Acrylic polymer [D] of the type and amount shown in Table 2 was blended, and methyl ethyl ketone was added thereto so that the solid content was 20% by weight to obtain a coating composition. On one surface of the substrate film prepared by the above method, the coating composition
Each was applied using a 5-bar coater. The coated film was kept in an oven at 130 ° C. for 1 minute to volatilize the solvent. The amount of coating of each film obtained is about 3
It was g / m ² .

IV. Evaluation of Film The performance of the film was evaluated by the following method, and the results are shown in Table 4. Initial Appearance The appearance of the films prepared in Examples and Comparative Examples was observed with the naked eye, and the linear light transmittance (wavelength 555 nm) was measured by EPS-2U type manufactured by Hitachi, Ltd. The evaluation criteria are as follows. I) Visual appearance ⊚: The surface gloss is uniform and free of roughness and wrinkles. B: Uneven surface gloss, no roughness, and no wrinkles. X: Surface gloss is uneven, rough, and wrinkled. II) 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%.

Initial Coloring Property The films prepared in Examples and Comparative Examples were thermally deteriorated in a gear oven at 170 ° C., and the colored state was visually observed every 20 minutes. ⊚: Transparent and has no yellowing. ○: Transparent, but some yellowing was observed. Δ: Yellowing is observed without transparency. X: No transparency and blackened.

Low temperature physical properties Impact strength / brittle fracture rate: Nine 10 cm × 10 cm samples of the films obtained in Examples and Comparative Examples were prepared, and J
The thickness of the central part of the sample is measured with a dial gauge specified in IS B-7503. The sample above -15
The measurement was performed by a puncture manufactured by Toyo Seiki Co., Ltd. in a room at ℃. The rate of brittle fracture (the material was destroyed by rapid progress of cracking with almost no plastic deformation) and the degree of impact are expressed by the following equations. Brittle fracture rate (%) = number of brittle fracture / 5 (excluding 2 sheets for each large and small) x 100 Impact strength = measured value (impact value) / measured thickness x nominal thickness

Outdoor extension test A roof type house (9m in opening, 5m in depth, 1.5m in building height) with 9 kinds of films installed in a test field in Isshi-gun, Mie prefecture,
A roof slope of 30 degrees) was coated with the surface having the coating on the side of the house, and a spreading test was performed for one year from March 1996 to February 1997. With respect to the stretched film, the residual elongation after weathering of the film, the impact strength at low temperature of the film, and the brittle fracture ratio were evaluated by the following methods. I) Tests and evaluations were carried out in the same manner as in the case of the low temperature physical properties. II) Dustproofness The value calculated by the following formula was judged according to the following evaluation criteria. (Light transmittance of film collected over time after spreading *)
/ (Light transmittance before spreading *) × 100 * Straight light transmittance at wavelength of 555 nm (Hitachi, EPS-2U type used) ⊙: Light transmittance after spreading is 90% or more before spreading. O: The light transmittance after spreading is in the range of 70 to 89% before spreading. Δ: The light transmittance after spreading is in the range of 50 to 69% before spreading. X: The light transmittance after spreading is less than 50% before spreading.

[0069]

[Table 1]

[0070]

[Table 2]

[0071]

[Table 3]

[0072]

[Table 4]

[0073]

[Table 5]

[0074]

As is apparent from the above examples, the present invention has the following effects, and its agricultural utility value is extremely large. (1) The vinyl chloride resin film for agriculture according to the present invention is excellent in processability. (2) The agricultural vinyl chloride resin film according to the present invention has little deterioration in physical properties after aging and is excellent in physical properties at low temperatures even at the end of use. (3) The agricultural vinyl chloride resin film according to the present invention is excellent in impact resistance at low temperature, and is resistant to tearing due to spreading and external force (wind, snow, hail, arale, etc.) after spreading. It has excellent properties.

(4) The agricultural vinyl chloride resin film according to the present invention does not become sticky at high temperatures such as summer. Moreover, since the elastic modulus is excellent, "slack" or the like does not occur at high temperatures such as in summer. (5) The vinyl chloride resin film for agriculture according to the present invention has a small degree of deterioration in dustproofness even when stretched outdoors.

In the vinyl chloride resin film for agriculture according to the present invention, by mixing certain specific acrylic elastic particles (certain particle size distribution / average particle diameter),
The workability improvement effect is brought out by the gelation promotion effect, and the impact strength improvement is brought out by the internal stress relaxation effect against the impact at low temperature (the remarkable relaxation effect of the internal stress due to the multilayer structure). It also maintains transparency. Furthermore, it brings out the effect of suppressing the deterioration of physical properties after weathering. As described above, the agricultural vinyl chloride resin film of the present invention is excellent in processability, impact resistance, and physical properties after weathering.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI Theme Coat (reference) C08L 33/00 C08L 33/00 (72) Inventor Murakami Makoto 2 Oike, Iwazuka-cho, Nakamura-ku, Aichi Prefecture Mitsubishi (72) Inventor Noboru Ichiyanagi No. 2 Oike, Iwazuka-cho, Nakamura-ku, Aichi Prefecture AK15A AK25A AK25B AK25J AL01A AL01B BA02 CA04A CA05A CA07A DE01A GB01 JA07A JK07A JK10 JL06 JL09 JN01 YY00A 4J002 BD041 BD051 BD061 BD071 BD081 BG062 BG063 EE038 EE049 EH056 EH096 EH106 EH146 EU077 EU087 EU178 EV218 EW049 EZ007 FD026 FD047 FD058 FD069 GA01

Claims (9)

[Claims] 1. A plasticizer [B] of 30 to 60 parts by weight and an average particle diameter of 100 to 300 with respect to 100 parts by weight of a vinyl chloride resin [A] having an average degree of polymerization of 1,000 or more and 2,500 or less.
μm, 25% separated particle size (D2
5) and 75% separated particle size (D75) ratio (D75 / D
Acrylic elastic particles [C], which is a polymer containing 25 to 1.05 to 2.5 and an alkyl methacrylate as a main component.
Methyl methacrylate 40-70 on one or both sides of a vinyl chloride resin film mixed with 0.5-20 parts by weight
% By weight, 5 to 30% by weight of hydroxyalkyl (methacrylate) compound, 0 to 20% by weight of α, β unsaturated carboxylic acid containing one or more carboxyl groups in the molecule, and others copolymerizable therewith A vinyl chloride resin film for agriculture, which is formed with a film of an acrylic resin [D] obtained by copolymerizing with the vinyl monomer. 2. The vinyl chloride resin film for agriculture according to claim 1, wherein the acrylic elastic particles are a multi-stage polymer (multilayer structure). 3. An acrylic elastic particle is a three-stage polymer (3
The vinyl chloride resin film for agriculture according to claim 1, which has a layer structure). 4. The acrylic elastic particle is a four-stage polymer (4
The vinyl chloride resin film for agriculture according to claim 1, which has a layer structure). 5. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin contains an acrylic copolymer. 6. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin contains a light stabilizer. 7. The agricultural vinyl chloride resin film according to any one of claims 1 to 6, wherein the vinyl chloride resin contains an ultraviolet absorber. 8. The vinyl chloride resin film for agriculture according to claim 1, wherein the vinyl chloride resin contains an organic phosphate ester or an organic phosphate metal salt. 9. The vinyl chloride resin film for agricultural use according to claim 1, wherein the vinyl chloride resin contains a β-diketone compound.