JP2001061356A - Agricultural vinyl chloride resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject film improved in physical properties such as mechanical strength and elongation and impact resistance at low temperatures, causing no 'slack' or the like at high temperatures such as in summer, and excellent in weatherability by forming an acrylic resin coating film on the surface of a specific vinyl chloride-based film. SOLUTION: This agricultural resin film is obtained by forming a coating film of (D) an acrylic resin produced by copolymerization between 40-70 wt.% of methyl methacrylate, 5-30 wt.% of a hydroxyalkyl (meth)acrylate, 0-20 wt.% of an α,β-unsaturated carboxylic acid and another vinyl-based monomer copolymerizable therewith on one side or both sides of a vinyl chloride-based resin film produced by compounding (A) 100 pts.wt. of a vinyl chloride-based resin 1,000-2,500 in average degree of polymerization with (B) 0.5-20 pts.wt. of a chlorinated polyethylene 15-50 wt.% in chlorine content, 0.5-150 g/10 min in melt index and 0-30% in degree of crystallinity and (C) 30-60 pts.wt. of a plasticizer such as di-n-octyl phthalate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vinyl chloride resin film for agricultural use. More specifically, it has good workability, and has excellent strength, impact resistance, and elongation at low temperatures against undesired phenomena such as tearing due to external forces (wind, snow, hail, arare, etc.) after stretching, and after outdoor exposure Of the material has a very small decrease in physical properties. Further, the present invention relates to a vinyl chloride resin film for agricultural use, which has a small decrease in dust resistance after outdoor exposure.

[0002]

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

[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.).

[0005] Further, methyl methacrylate as an impact modifier is added to a general vinyl chloride resin composition for molded articles.
Butadiene-styrene copolymer (MBS resin) (JP-A-6-322209), acrylonitrile-butadiene-
Styrene copolymer (ABS resin), styrene-butadiene rubber (SBR) and the like have been proposed. These impact modifiers improve the impact resistance, but the double bond contained in the molecule has Because they are active against light, ultraviolet rays or heat, vinyl chloride resin films obtained from resins containing them have the disadvantage of poor weather resistance (browning). It has been proposed to add an antioxidant, a light stabilizer and the like, but satisfactory satisfactory physical properties have not been obtained. On the other hand, the vinyl chloride resin film used for agriculture has a drawback that the dustproof property outside the house or tunnel is reduced due to the influence of the area or place where the film is stretched.

[0006]

Under such circumstances, the present inventors have studied the properties at low temperatures (elongation, strength, impact resistance).
Further, an object of the present invention was to provide a vinyl chloride resin film for agricultural use, in which the physical properties of the film after exposure to the outdoors (after aging) are significantly reduced. Moreover, it is excellent in workability at the time of forming a film, does not break when it is stretched in a cold area, and does not break due to external force such as wind, snow, hail, or arare after stretching outdoors. In addition, in order to provide a vinyl chloride resin film for agricultural use which does not cause stickiness or sagging (improvement in elastic modulus) at high temperatures such as in summer and has a small decrease in dust resistance even after lapse of time. As a result of the study, the present invention has been completed.

[0007]

The gist of the present invention is that 0.5 to 20 parts by weight of chlorinated polyethylene [B] is added to 100 parts by weight of vinyl chloride resin [A]. An agricultural vinyl chloride resin film characterized in that a coating of an acrylic resin [C] is formed on one or both surfaces of a vinyl chloride resin film mixed with 30 to 60 parts by weight of an agent. Alternatively, an agricultural vinyl chloride resin film in which an acrylic resin film is formed on one or both sides of a resin film containing a vinyl chloride resin as a main resin, and 3 g /
(a) When a coating having a thickness of m ² is formed, the impact strength at −15 ° C. is 30 kg / m ² or more, and (b) −15 ° C.
In which the brittle fracture rate is 20% or less, and (c) the tensile elongation at break at 23 ° C. is 350% or more.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. 1. Vinyl Chloride Resin [A] 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 preferably has an average degree of polymerization of 1,000 or more and 2500 or less, more preferably 1100 or more and 2000 or less. Further, 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. However, two kinds of resins having apparently different average degrees of polymerization may be mixed by controlling the polymerization conditions during the polymerization of the vinyl chloride resin. It may be the method that has been done.

In order to impart flexibility to the vinyl chloride resin film serving as the substrate, a plasticizer is used in an amount of 30 to 60 parts by weight, preferably 4 parts by weight, based on 100 parts by weight of the resin.
0 to 55 parts by weight are blended. 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 [B] The chlorinated polyethylene of the present invention means that the raw material polyethylene is a homopolymer of ethylene or ethylene and
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 is preferably in the range of 15 to 50% by weight. If the amount is too small, the compatibility with the vinyl chloride resin is inferior, and the film becomes cloudy, which is not preferable. If the amount is too large, the physical properties at low temperatures are not improved. Even within the above range, 30 to 50% by weight is preferable, and 35 to 45% by weight is particularly preferable.

The melt index of the chlorinated polyethylene is preferably in the range of 0.5 to 150 g / 10 minutes. If it is too small, the compatibility with the vinyl chloride resin is inferior, and the film becomes cloudy. If it is too large, the physical properties do not improve in proportion to the added amount, which is not preferable. Even within the above range, 1.0 to 130 g / 10 minutes is particularly preferable. The crystallinity of the chlorinated polyethylene is preferably from 0 to 30%. 0% means that it includes a non-crystalline state. If the range is too high, the compatibility with the vinyl chloride resin is poor, and bleeding on the film surface is not preferable. 20% or less even within the above range,
Alternatively, the content is preferably 0.01% or more, and particularly preferably 1 to 20%.

3. Acrylic copolymer The agricultural vinyl chloride resin film of the present invention preferably contains an acrylic copolymer from the viewpoint of processability. The acrylic copolymer is preferably one obtained by using a methyl methacrylate monomer as a main monomer and copolymerizing a methyl methacrylate monomer with a copolymerizable vinyl monomer monomer.

The copolymerization ratio is as follows: (A) 60 to 100% by weight of methyl methacrylate, and (B) 0 to 100% of a vinyl monomer monomer copolymerizable with a methyl methacrylate monomer.
Preferably it is 40 parts by weight. If the amount 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 appearance of the film is poor.

As vinyl monomer monomers copolymerizable with methyl methacrylate, ethyl acrylate, 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.
-C16 alkyl esters: C1-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: styrene, acrylonitrile, methacrylonitrile and the like. These vinyl monomer monomers copolymerizable with methyl methacrylate may be copolymerized by one kind or a combination of several kinds.

The amount of the acrylic copolymer to be added to the vinyl chloride resin is preferably in the range of 0.1 to 10 parts by weight. If the amount is less than 0.1 part by weight, the processability is not improved and 1
When the amount is more than 0 parts by weight, both the processability and the physical properties are not improved in proportion, which is not preferable. Even in the above range, 0.5 to 5 parts by weight is particularly suitable. Acrylic copolymer is charged in a polymerization vessel together with an organic solvent or water by combining two or more of the above monomers in a predetermined amount, a polymerization initiator,
If necessary, a molecular weight regulator is added, and the mixture is heated and polymerized with stirring. For the polymerization, a known method such as a suspension polymerization method, a solution polymerization method, or an emulsion polymerization method is employed.

4. β-diketone compound It is preferable to mix a β-diketone compound in the agricultural vinyl chloride resin film of the present invention from the viewpoint of preventing discoloration due to heat during processing. The β-diketone compound may be any compound that is usually compounded 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.

[0021]

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(In the formula [I], R1 and R2 each have 1 carbon atom.
4 to 4 alkyl groups or phenyl groups. Examples of what is included in the general formula [I] include acetylacetone, benzoylacetone, benzoylpropionylmethane, dibenzoylmethane and the like. β-
The compounding amount of the diketone compound in the vinyl chloride resin film is not preferable because if it is too small, discoloration occurs due to heat during molding processing, and even if it is too large, the coloring resistance of the film is proportional to the amount added. There is no improvement. The preferable amount is 0.1 parts by weight based on 100 parts by weight of the vinyl chloride resin.
005 to 0.10 parts by weight.

5. Light Stabilizer It is preferable to add a light stabilizer to the vinyl chloride resin film for agriculture of the present invention from the viewpoint of coatability and outdoor expandability. The light stabilizer may be any one as long as it is usually compounded in a vinyl chloride film for agricultural use, and examples thereof include a hindered amine type and a metal complex salt type. Particularly, a hindered amine light stabilizer is preferable. Specifically, the following are mentioned. As hindered amine light stabilizers,
Compounds containing one or more structural units represented by the following general formula [II] or [III] in one molecule are suitable.

[0024]

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

[0026]

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(In the formula [III], R1 to R4 each have 1 carbon atom.
An alkyl group of 4 to 4, R5 represents hydrogen or an alkyl group having 1 to 4 carbon atoms. For example, a hindered amine compound represented by the general formula [IV] is a typical example.

[0028]

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(Wherein, R is a mono- to tetraacyl group derived from phosphorus or a mono- to tetra-valent carboxylic acid, and n is 1 to 4
Are respectively shown. Examples of the compounds included in the general formula [IV] are specifically exemplified in, for example, JP-B-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.

As the metal complex salt light stabilizer, the metal is preferably nickel and cobalt. Specifically, the following are mentioned. Nickel metal complex: nickel [2,2'thiobis (4-
Tert-octyl) phenolate] normal butylamine, nickel dibutyldithiocarbamate, nickel bis [oethyl 3,5 (ditertiarybutyl 4-hydroxybenzyl)] phosphate, nickel bis (octylphenyl sulfide) and the like. Cobalt metal complex: Cobalt dicyclohexyl dithiophosphate, [1-phenyl, 3-methyl, 4-decanoyl, pyrazolate (5) 2] nickel and the like.

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 high, so that it is not preferable. Spouting on the film surface occurs without a proportional improvement. The preferred amount is 0.1 to 100 parts by weight of the vinyl chloride resin.
The range is 1.0 part by weight.

The vinyl chloride resin film for agricultural use of the present invention is preferably used in combination with an ultraviolet absorber and a light stabilizer from the viewpoint of coatability and outdoor expandability. 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. Particularly, a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber are preferable. Specifically, the following are mentioned.

Benzophenone ultraviolet 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'-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 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-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'-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-tert-butylphenyl) -5-chlorobenzotriazole, 2-
(2'-hydroxy-3'-methyl-5'-t-butylphenyl) -5-chlorobenzotriazole, 2-
(2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2-
(2'-hydroxy-5'-methoxyphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-
Di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'-cyclohexylphenyl) benzotriazole, 2- (2'-hydroxy-4 ', 5'-dimethylphenyl) -5 -Carboxylic acid benzotriazole, 2- (2'-hydroxy-5-methylphenyl) -5-carboxylic acid butyl ester benzotriazole, 2- (2'-hydroxy-4 ', 5'-
Dichlorophenyl) benzotriazole, 2- (2'-
Hydroxy-3 ', 5'-dimethylphenyl) -5-ethylsulfobenzotriazole, 2- (2'-hydroxy-4'-octoxyphenyl) benzotriazole,
2- (2'-hydroxy-5'-methoxyphenyl)-
5-methylbenzotriazole, 2- (2'-hydroxy-5'-methylphenyl) -5-carboxylic acid ester benzotriazole, 2- (2'-acetoxy-methylphenyl) benzotriazole.

The blending amount of the above-mentioned ultraviolet absorber in the base film is based on 100 parts by weight of the base vinyl chloride resin.
A range of 0.02 to 8 parts by weight is preferred. When the amount is less than 0.02 parts by weight, the weather resistance of the agricultural vinyl chloride resin film is not sufficiently excellent, which is not preferable. On the other hand, when the amount is more than 8 parts by weight, there is a problem that the film is spouted onto the film surface together with other additives when the film is used, which is not preferable. Within the above range, 0.
A range of 1 to 3 parts by weight is preferred.

6. Organic Phosphate Esters or Organic Phosphate Metal Salts In the vinyl chloride resin film for agriculture of the present invention, it is preferable to blend an organic phosphate ester or an organic phosphate metal salt with the vinyl chloride resin. Examples of the organic phosphate include triisopropyl phenyl phosphate, isodecyl diphenyl phosphate, tris (isopropyl phenyl) phosphate, tributyl phosphate,
Triethyl phosphate, trioctyl phosphate,
Tributoxyethyl phosphate, triphenyl phosphate, octyl diphenyl phosphate, trixylenyl phosphate, etc. are preferred, and tricresyl phosphate and trixylenyl phosphate are particularly preferred.

The above organic phosphates can be used alone or in the form of a composite. For example, a complex of an organic phosphoric acid ester and an organic phosphite ester may be mentioned, and the organic phosphoric acid ester also includes a phosphonate compound such as diphenyl phosphate. As the organic metal phosphate, a compound represented by the general formula [V] or [VI]

[0038]

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[0039]

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(Wherein M represents zinc, calcium, barium, magnesium, cobalt or strontium, and R1, R2 and R3 are each alkyl,
An alkyl group having an aryl, arylalkyl, alkylaryl or ether bond is meant. ). Examples of the alkyl group represented by R1, R2 and R3 include methyl, ethyl, propyl,
Isopropyl, butyl, isobutyl, sec-butyl, tertiary
Butyl, amine, neopentyl, isoamyl, hexyl, isohexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, decyl, isodecyl, lauryl, tridecyl, C12-C13 mixed alkyl, stearyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, 4- And a methylcyclohexyl group.

Examples of the aryl group include phenyl and naphthyl groups. Examples of the arylalkyl group include a benzyl, β-phenylethyl, α-phenylpropyl, β-phenylpropyl group and the like. Examples of alkylaryl groups include tolyl,
Xylyl, ethylphenyl, butylphenyl, tertiary butylphenyl, octylphenyl, isooctylphenyl, tertiary octylphenyl, nonylphenyl, 2,4-
And di-tert-butylphenyl group.

As the alkyl group having an ether bond, furfuryl, tetrahydrofurfuryl, 5-methylfurfuryl and α-methylfurfuryl, or methyl-, ethyl-, isopropyl-, butyl-, isobutyl-, hexyl- , Cyclohexyl-, phenyl cellosolve residue; methyl-, ethyl-, isopropyl-, butyl-, isobutyl carbitol residue; triethylene glycol monomethyl ether, -monoethyl ether, -monobutyl ether residue; 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.

The metal represented by M is particularly preferably zinc, calcium or barium. These organic phosphates or metal organic phosphates can 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 a metal organic phosphate in combination from the viewpoint of coatability and outdoor expandability.

The amount of the organic phosphoric acid ester or the organic phosphoric acid metal salt is in the range of 0.1 to 15 parts by weight, preferably 0.2 to 1 part by weight, per 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 part by weight, the weather resistance and dust resistance of the soft vinyl chloride resin film are not improved. If the amount is more than 15 parts by weight, the transparency of the film becomes extremely poor, which is not preferable. Within the above range, it is particularly preferred that the range be 0.2 to 8 parts by weight.

Of course, in addition to the above-mentioned plasticizers, acrylic copolymers, coloring inhibitors, light stabilizers, organic phosphates or metal organic phosphates, and ultraviolet absorbers, the vinyl chloride resin must contain Depending on the known resin additives usually compounded in the synthetic resin for molding, for example, a lubricant, a heat stabilizer, an antioxidant, a stabilizing aid, an antistatic agent, an antifogging agent, a fungicide,
An anti-algal agent, an inorganic ferrer, a coloring agent and the like can be blended.

Examples of the lubricant that can be blended in the film according to the present invention include polyethylene wax, bisamide compounds, liquid paraffin, and the like, and examples of the antioxidant include organic phosphite compounds. Also,
Examples of the heat stabilizer include β-diketone compounds. Each of the above various resin additives can be used alone or in combination of several types. The amount of the above various resin additives is within a range not deteriorating the properties of the film, and is usually 1 to 100 parts by weight of the base vinyl chloride resin.
It can be selected in the range of 0 parts by weight or less.

To blend the plasticizer, the light stabilizer, the ultraviolet absorber, the organic phosphate or the metal organic phosphate, and other resin additives with the vinyl chloride resin serving as the base of the film, Weigh the required amount, ribbon blender,
Banbury mixers, super mixers and other conventionally known blending machines and mixers may be used. In order to form a film of the resin composition thus obtained, a method known per se, for example, a melt extrusion method (T-die method,
(Including an inflation method), a calendar molding method, a solution casting method, and the like.

7. Coating component 7-1 Acrylic resin [C] In the present invention, an organic solvent-based or water-based, preferably organic solvent-based acrylic resin coating is formed on one or both surfaces of the film. Particularly preferred acrylic resins include 40 to 70% by weight of methyl methacrylate, 5 to 30% by weight of a hydroxyalkyl (meth) acrylate compound, and α, β unsaturated carboxylic acids containing one or more carboxyl groups in the molecule. A copolymer obtained by copolymerizing a monomer mixture containing 0 to 20% by weight and another vinyl monomer copolymerizable therewith is exemplified. If the amount of the methyl methacrylate is too large, physical properties at a sufficiently low temperature cannot be maintained. On the other hand, if the amount is too small, the dustproof effect cannot be exhibited, which is not preferable.

The 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.

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, and on the other hand, it is more than 30% by weight. In such a case, the effect obtained is not so great as compared with the cost increase, which is not preferable. Α containing one or more carboxyl groups in the molecule,
Examples of the β-unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, aconitic acid, fumaric acid, crotonic acid and the like.

Examples of the above-mentioned methyl methacrylate monomer, hydroxyalkyl (meth) acrylate monomer and other vinyl monomers copolymerizable with an α, β-unsaturated carboxylic acid include, for example, methyl acrylate, ethyl acrylate, n-propyl Alkyl acrylate having an alkyl group such as acrylate, isopropyl acrylate, and 2-ethylhexyl acrylate having a side chain of 1 to 8; an alkyl group having an alkyl group such as ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, and 2-ethylhexyl methacrylate having a side chain of 2 to 8; Alkyl methacrylates; α, β-ethylenically unsaturated phosphonic acids such as ethylene sulfonic acid; hydroxyl-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.

7-2 Polymerization of Acrylic Polymer [C] A predetermined amount of a monomer is blended, charged into a polymerization vessel together with an organic solvent, a polymerization initiator and, if necessary, a molecular weight regulator are added, and the mixture is stirred. While heating, polymerize. For the polymerization, generally known methods such as a suspension polymerization method and a solution polymerization method are employed. In this case, the polymerization initiator that can be used includes α, α-
Radical generation catalysts such as azobisisobutyronitrile, benzoyl peroxide, cumene hydroperoxide and the like, and molecular weight regulators include butyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, β-mercaptoethanol and the like Can be

The organic solvent used for the polymerization includes methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol.
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; and acetates 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, neutralizers, 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;
Alcohols such as methanol, ethanol, isopropyl alcohol, and polyoxyethylene glycol; halogenated hydrocarbons such as chloroform, tetrachloride hydrocarbon, and chlorobenzene; esters such as methyl acetate, allyl acetate, and ethyl stearate; amines such as trimethylamine; Diphenylamine, hexamethylenediamine, etc .; other dimethylformamide,
There are dimethylacetamide, dioxane, diethyl ether, diethylenedithioglycol, diacetone alcohol, benzonitrile, dimethylsulfoxide and the like, which can be used alone or in combination of two or more.

It is also possible to mix other resins compatible with the acrylic resin, such as vinylidene fluoride resin, acrylic resin having a perfluoroalkyl group in the side chain, and cellulose acetate butyrate. Rate resin, silicone resin, etc. are particularly effective. To form a dust-proof coating on the surface of the base film, a solution or dispersion of each composition is coated with a doctor blade, a gravure roll, an air knife, a reverse roll, a deep coat, or a curtain roll. Coating methods such as a coating method, a spray coating method, and a rod coating method are used. When the coating composition is formed as a single coating without being in a solution state, coextrusion, extrusion coating, extrusion lamination, and lamination are used. As a method for forming a film, as a method for drying a solvent in the case of using a coating method, for example, there are an air drying method, a hot air drying method, an infrared drying method, a far infrared drying method, and the like. Hot air drying is advantageous. In this case, the temperature condition is in the range of 50 ° C. to 200 ° C., and the time is preferably selected from 10 seconds to 15 minutes.

In the present invention, the thickness of the coating formed on the surface of the base film is preferably 1/10 or less of the base film. The thickness of the coating is 1/1 of the base film
If the value is larger than 0, since there is a difference in flexibility between the base film and the coating, phenomena such as peeling of the coating from the base film are likely to occur, and cracks are generated in the coating to reduce the strength of the base film. This phenomenon is undesirable.

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

As described above, the present invention provides an unprecedented novel agricultural polyvinyl chloride resin film, that is, an acrylic resin coating on one or both surfaces of a base film mainly composed of a vinyl chloride resin. (A) when a 3 g / m ² thick film is formed on a 0.10 mm thick base film,
The impact strength at 15 ° C is 30 kg / m ² or more, the brittle fracture rate at (b) -15 ° C is 20% or less, and the tensile elongation at 23 ° C is 350% or more. It is a vinyl chloride resin film for agricultural use. Further, it is an agricultural vinyl chloride resin film containing chlorinated polyethylene in addition to the vinyl chloride resin, and the acrylic resin is 40 to 70% by weight of methyl methacrylate, hydroxyalkyl (meth) acrylate 5 to 30% by weight of a compound, 0 to 20% by weight of an α, β unsaturated carboxylic acid containing one or more carboxyl groups in a molecule, and another vinyl monomer copolymerizable therewith. It is a specific acrylic resin obtained by copolymerization.

In a more preferred embodiment, (a) -15
Impact strength at 35 ° C is 35 kg / m ^TwoAbove, optimally 4
0kg / m^Two(B) at −15 ° C.
The brittle fracture rate should be 15% or less, and optimally 10% or less.
And (c) a tensile elongation at break of 380% at 23 ° C.
As mentioned above, it is optimally 400% or more.
The upper limit of (a) and (c) and the lower limit of (b) are particularly limited.
However, preferably, (a) is 60 kg / m^TwoLess than,
(B) 0% or more and (c) 500% or less.
I can do it.

The measurement of (a) impact strength and (b) brittle fracture rate at −15 ° C. was carried out in accordance with the provisions of JIS B-7503.
Nine samples of 10 cm × 10 cm were prepared by forming an acrylic film having a thickness of ² and were placed in a room at −15 ° C.
The measurement is performed by measuring the thickness at the center of the sample with a dial gauge specified in ISB-7503.

The brittle fracture (the material was destroyed by the rapid growth of cracks with almost no plastic deformation) is represented by the following formula. Brittle fracture rate (%) = number of brittle fractures / 5 (excluding two large and small) × 100 Impact strength = measured value (impact value) / measured thickness × nominal thickness

On the other hand, (c) the tensile elongation at break at 23 ° C. was 3 g / m 3 for a base film formed to a thickness of 0.10 mm.
JIS by using a sample formed ^two thick coating K67
The measurement is performed in a room at 23 ° C. in accordance with No. 32. Here, a base film having a thickness of 0.10 mm and 3 g /
The reason why the film was formed to have a thickness of m ² is to unify the measurement conditions, and does not limit the thickness of the agricultural polyvinyl chloride resin film to which the present invention is applied. The thickness of the base film of the present invention can be any thickness, but is usually 0.0
Range of 3 to 0.3 mm, preferably 0.05 to 0.2
mm. In addition, at least one surface of the film may have a lattice shape, a stripe shape, or a fine uneven pattern (texture pattern). Further, the vinyl chloride resin film for agricultural use in the present invention, on the inner surface when actually expanded in a house or tunnel, acrylic resin or the like, solvent-based paint,
An antifogging coating film may be formed by applying a coating film obtained by adding a colloidal inorganic substance such as colloidal silica or colloidal alumina to a coating material such as a water-based coating material or an ultraviolet curable coating material.

[0063]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention. I. Preparation of Base Film Examples 1-3, Comparative Examples 1-2 Vinyl chloride resin (average degree of polymerization 1500) 100 parts by weight Di-2-ethylhexyl phthalate (DOP) 45 parts by weight chlorinated polyethylene (composition shown in Table 1, (Parts shown in Table 3) Epoxy resin 3 parts by weight Barium-zinc composite liquid stabilizer 1.5 parts by weight Barium stearate 0.2 parts by weight Zinc stearate 0.4 parts by weight Sorbitan laurate 1.5 parts by weight A resin composition consisting of 2.0 parts by weight of an acrylic copolymer (METABLEN P-570A manufactured by Mitsubishi Rayon Co., Ltd.) was prepared, and β-diketone compounds and organic phosphates of the types and amounts shown in Table 3 were prepared. Alternatively, an organic metal phosphate, a light stabilizer and an ultraviolet absorber were 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 prepare a substrate film having a thickness of 0.10 mm.
However, Comparative Examples 1 and 6 did not contain a β-diketone compound.

Comparative Example 3 Vinyl chloride resin (average degree of polymerization: 1500) 100 parts by weight Di-2-ethylhexyl phthalate (DOP) 20 parts by weight Chlorinated polyethylene (composition shown in Table 1, parts by weight shown in Table 3) Epoxy Resin 3 parts by weight Barium-zinc composite liquid stabilizer 1.5 parts by weight Barium stearate 0.2 parts by weight Zinc stearate 0.4 parts by weight Sorbitan laurate 1.5 parts by weight Acrylic copolymer (Mitsubishi Rayon ( A resin composition consisting of 2.0 parts by weight of Metablen P-570A) was prepared, and a base film having a thickness of 0.10 mm was prepared using the same additives and the same processing method as in Examples 1 to 3. .

II. Preparation of Acrylic Polymer [C] 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 100 parts by weight of a mixture of each monomer shown in the table was charged,
While stirring under a nitrogen gas stream, 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 [C] of the type and amount shown in Table 3 was blended, and methyl ethyl ketone was added thereto so that the solid content was 20% by weight, to obtain a coating composition. Was. On one surface of the substrate film prepared by the above method,
Each was applied 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 film obtained was about 3
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 straight light transmittance (wavelength: 555 nm) was measured with an EPS-2U model manufactured by Hitachi, Ltd. The evaluation criteria are as follows. I) Visual appearance ◎: The surface has no unevenness, and is rough and has no wrinkles. Δ: Uneven or rough and wrinkle-free surface gloss. X: Irregular, rough and wrinkled surface gloss. II) Straight ray transmittance ◎: The transmittance is 85% or more. …: Transmittance of 65% to 84%. Δ: transmittance of 45% to 64%. ×: transmittance is less than 45%.

Initial Colorability The films prepared in Examples and Comparative Examples were thermally degraded in a gear oven at 170 ° C., and the colored state was visually observed every 20 minutes. A: Transparent and completely free of yellowing. …: Transparent, but slightly yellowed. Δ: No transparency and yellowing observed. X: blackened without transparency.

Room Temperature Physical Properties I) Tensile Properties: The films obtained in Examples and Comparative Examples were subjected to room temperature at 23 ° C. in accordance with JIS K6732.
The elongation at break was measured. II) Tensile properties after accelerated weathering: The films obtained in Examples and Comparative Examples were acceleratedly degraded according to JIS K6732, and then the elongation at break was measured. III) Residual elongation: The residual elongation after the test was determined according to JIS K6732.
And the residual elongation was determined from the following general formula. Residual elongation (%) = Elongation before weathering promotion (%) / Elongation after weathering promotion (%) × 100

Low-temperature physical properties Impact strength / brittle fracture rate: Nine samples of 10 cm × 10 cm were prepared from the films obtained in Examples and Comparative Examples.
The thickness at the center of the sample is measured with a dial gauge specified in IS B-7503. The above sample was -15
The temperature was measured using a puncture manufactured by Toyo Seiki Co., Ltd. in a room at a temperature of ° C. In addition, the brittle fracture (the material was destroyed by the rapid propagation of cracks with almost no plastic deformation) is represented by the following formula. Brittle fracture rate (%) = number of brittle fractures / 5 (excluding two large and small) × 100 Impact strength = measured value (impact value) / measured thickness × nominal thickness

Outdoor Extension Test Various films were mounted on a roof-type house (opening 3 m, depth 5 m, building height 1.5 m,
(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 1996 to February 1997. 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. Tests and evaluations were carried out in the same manner as in (I) Room temperature physical properties. II) Tests and evaluations were performed in the same manner as in the low temperature physical properties. III) Dustproofness The value calculated by the following equation was judged according to the following evaluation criteria. (Light transmittance * of the film collected over time after stretching)
/ (Light transmittance before expansion *) × 100 * Straight light transmittance at wavelength of 555 nm (using EPS-2U type manufactured by Hitachi, Ltd.)…: Light transmittance after expansion 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. C: Light transmittance after expansion is less than 50% before expansion.

[0073]

[Table 1]

[0074]

[Table 2]

[0075]

[Table 3]

[0076]

[Table 4]

[0077]

[Table 5]

[0078]

[Table 6]

[0079]

As described above, the present invention has the following effects, and its agricultural utility value is extremely large. (1) The agricultural polyvinyl chloride resin film according to the present invention is excellent in processability. (2) The vinyl chloride resin film for agriculture according to the present invention has a small decrease in physical properties at low temperatures after aging, and has excellent physical properties at low temperatures even at the end of use. (3) The vinyl chloride resin film for agriculture according to the present invention has excellent physical properties at low temperatures, and is resistant to tearing due to expansion and tearing due to external force after expansion (wind, snow, hail, arare, etc.). Are better.

(4) The vinyl chloride resin film for agricultural use according to the present invention does not become sticky at high temperatures such as in summer. Further, since the elastic modulus is excellent, "slack" or the like does not occur at a high temperature such as in summer. (5) The vinyl chloride resin film for agricultural use according to 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 chlorinated polyethylene bring out the improvement of physical properties at low temperature, and furthermore, the weather resistance is improved. It brings out the effect of suppressing the subsequent deterioration of physical properties. 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 Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // (C08L 27/06 23:28) (72) Inventor Murakami Ishizuka Oike, Iwatsukacho, Nakamura-ku, Nagoya-shi, Aichi No. 2 Mitsubishi Chemical MKV Corporation Nagoya Office (72) Noboru Ichiyanagi Inventor No. 2 Oike, Iwatsuka-cho, Nakamura-ku, Nagoya-shi, Aichi Prefecture Mitsubishi Chemical MKV Corporation Nagoya Office F-term (reference) 2B024 DB01 DB07 2B029 EB03 EB16 EC04 EC06 EC09 EC19 RA03 4F100 AH10A AK02B AK02C AK10A AK15A AK25B AK53 AK71B AK71C BA02 BA03 BA06 BA10B BA10C BA15 CA04A CA05A CA07A GB01 JA07A JA11A JK02 JK10 JL01 JL09 YY00 YY00A YY00B YY00C 4J002 BB242 BD041 BD051 BD061 BD071 BD081 BG063 EE038 EE049 EH096 EH146 EU077 EU178 EW049 EW129 FD026 FD047 FD058 FD170 GA01

Claims (12)

[Claims] 1. One side of a vinyl chloride resin film in which 0.5 to 20 parts by weight of a chlorinated polyethylene [B] and 30 to 60 parts by weight of a plasticizer are mixed with 100 parts by weight of a vinyl chloride resin [A]. Or a vinyl chloride resin film for agricultural use, characterized in that a film of an acrylic resin [C] is formed on both surfaces. 2. The vinyl chloride resin has an average degree of polymerization of 10
The vinyl chloride resin film for agricultural use according to claim 1, wherein the vinyl chloride resin film has a size of from 00 to 2500. 3. The chlorinated polyethylene having a chlorine content of 1
5-50% by weight, melt index 0.5-150g
The polyvinyl chloride resin film for agricultural use according to claim 1 or 2, wherein the crystallinity is 0 to 30% for / 10 minutes. 4. The acrylic resin [C] contains 40 to 70% by weight of methyl methacrylate, 5 to 30% by weight of a hydroxyalkyl (meth) acrylate compound, and contains one or more carboxyl groups in the molecule. An acrylic resin obtained by copolymerizing 0 to 20% by weight of a β-unsaturated carboxylic acid and another vinyl monomer copolymerizable therewith. Item 4. The vinyl chloride resin film for agricultural use according to any one of the items 3 to 3. 5. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin film contains an acrylic copolymer. 6. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin film contains a light stabilizer. 7. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin film contains an ultraviolet absorber. 8. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin film contains an organic phosphate or an organic metal phosphate. 9. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin film contains a β-diketone compound. 10. An agricultural vinyl chloride resin film in which an acrylic resin film is formed on one or both surfaces of a resin film containing a vinyl chloride resin as a main resin,
(A) When a 3 g / m ² thick film is formed on a 0.10 mm thick film, the impact strength at −15 ° C. is 30 kg.
/ M ² or more, (b) a brittle fracture rate at -15 ° C. of 20% or less, and (c) a tensile breaking elongation at 23 ° C. of 350% or more, characterized in that it is a vinyl chloride resin film for agricultural use. . 11. The film according to claim 10, wherein the vinyl chloride resin film contains chlorinated polyethylene.
The agricultural polyvinyl chloride resin film described in the above. 12. A film of the acrylic resin comprising 40 to 70% by weight of methyl methacrylate, 5 to 30% by weight of a hydroxyalkyl (meth) acrylate compound, α having one or more carboxyl groups in a molecule, 12. An acrylic resin obtained by copolymerizing 0 to 20% by weight of .beta. unsaturated carboxylic acid and another vinyl monomer copolymerizable therewith. The agricultural polyvinyl chloride resin film described in the above.