JP2001016999A - Agricultural vinyl chloride-based resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an agricultural vinyl chloride-based resin film having improved physical properties (strength) at a low temperature, and further having markedly reduced deterioration of its physical properties (strength, dust prevention, adhesion, anti-fog property, etc.), on being exposed in the outdoors (after an elapsed time). SOLUTION: This agricultural vinyl chloride-based resin film is characterized by forming a membrane derived from an anti-fog agent composition containing a silica sol and/or an alumina sol and a thermoplastic resin on the one side surface or both surfaces of a vinyl chloride-based resin film obtained by blending 0.5-20 pt.wt. chlorinated polyethylene and 30-60 pt.wt. plasticizer based on 100 pts.wt. vinyl chloride-based resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vinyl chloride resin film for agricultural use. More specifically, it has excellent durability against undesired deterioration phenomena such as discoloration, embrittlement, and reduced dust resistance caused by stretching outdoors, and also has excellent mechanical strength and impact resistance at low temperatures. The present invention relates to a vinyl chloride resin film for use.

[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, there is a need for a method for improving physical properties such as elongation and impact resistance in cold regions.

Incidentally, as a vinyl chloride resin composition used for general molded article applications, methyl methacrylate-butadiene-styrene copolymer (MBS resin) (JP-A-6-322209), acrylonitrile-
It has been proposed to add butadiene-styrene copolymer (ABS resin), styrene-butadiene rubber (SBR), etc., but these impact modifiers have improved impact resistance but are contained in the molecule. The double bond is
Because they are active against ultraviolet rays or heat, vinyl chloride resin films obtained from resins containing them have the disadvantage of poor weather resistance (browning), whereas ultraviolet absorbers and antioxidants It has been proposed to add agents, light stabilizers, etc., but satisfactory satisfactory physical properties have not been obtained. On the other hand, the properties required for vinyl chloride resin films used for agriculture are that the outer surface is not stained for a long period of time, has excellent dust resistance, maintains good light transmittance, and promotes the growth of cultivated crops. thing. Excellent in `` anti-fog '' that coagulated water attached to the inner surface of the coating material flows out along the inner surface of the film without falling to the cultivated crop, maintaining the house or tunnel at an appropriate humidity, The occurrence may be suppressed.

[0005]

Under such circumstances, the present inventors have greatly improved the undesired deterioration phenomena such as discoloration embrittlement, dustproofness and reduced antifogging property caused by stretching outdoors. The present inventors have conducted intensive studies with the aim of providing an agricultural vinyl chloride resin film having improved impact resistance at low temperatures, and as a result, have completed the present invention.

[0006]

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]. One or both sides of a vinyl chloride resin film mixed with 30 to 60 parts by weight of the agent [C], silica sol and / or
Or an agricultural vinyl chloride resin film having a coating derived from an antifogging agent composition containing alumina sol and a thermoplastic resin, and more preferably an acrylic resin [D] on the other surface of the film. And a vinyl chloride resin film for agricultural use, wherein a film of a composition mainly composed of vinylidene fluoride resin [E] is formed.

[0007]

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 usable plasticizer [C] include phthalic acid derivatives such as di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate and diisodecyl phthalate; isophthalic acid derivatives such as dioctyl phthalate; Di-n-butyl adipate,
Adipic acid derivatives such as 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; Epoxidized large oil, epoxy resin plasticizer and the like. 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, (B) 0 to 100% of a vinyl 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.

Examples of vinyl monomer 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.
-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 blended with 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. 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 at least one structural unit represented by the following general formula [II] or [III] in one molecule are suitable.

[0020]

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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. )

[0022]

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(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 compound represented by the general formula [IV] Compounds are representative.

[0024]

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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 light stabilizer, the metal is preferably nickel or cobalt. Specifically, the following are mentioned. Nickel metal complex: nickel [2
2 ′ thiobis (4-tert-octyl) phenolate] normal butylamine, nickel dibutyl dithiocarbamate, nickel bis [oethyl 3,5 (ditert-butyl 4-hydroxybenzyl)] phosphate,
Nickel bis (octylphenyl sulfide) and the like can be mentioned. 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.

5. Ultraviolet absorber It is preferable to use an ultraviolet absorber together with the vinyl chloride resin film for agriculture of the present invention 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 compounding 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.

In the agricultural film of the present invention, it is preferable to use an organic phosphoric acid ester and an organic metal phosphate in combination from the viewpoints of coatability and outdoor expandability.

The compounding 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 plasticizer, acrylic copolymer, coloring inhibitor, light stabilizer, organophosphate or organophosphate metal salt, and ultraviolet absorber, 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 which 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.

In order to blend the plasticizer, light stabilizer, ultraviolet absorber, organic phosphate or 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.

6. Anti-fogging coating (anti-fogging coating) A coating derived from an anti-fogging agent composition containing silica sol and / or alumina sol and a thermoplastic resin is formed on one or both sides, preferably one side, of the base film of the present invention. Is done. Silica sol and alumina sol refer to a dispersion system in which colloidal silica or colloidal alumina is dispersed in a liquid. Colloidal silica and / or colloidal alumina preferably have an average particle size of 5 to 100 μm. When the average particle size exceeds 100 μm, the coating film is white and easily devitrified, and when the average particle size is less than 5 μm, the stability of the anti-fogging composition is lacking. Each of these may be used alone or in combination. When used alone or in combination, two or more kinds having different average particle diameters may be used in combination. When both are combined, the weight ratio of silica sol / alumina sol is 95-5 / 5-95 (1 as a whole).
00). The alumina sol may be a commercially available product itself or an aqueous sol obtained by dispersing a commercially available alumina powder in water. Colloidal alumina shows a so-called thixotropic property that the viscosity of the dispersion rapidly increases when water is to be dispersed at a high concentration, and it is difficult to obtain a uniform dispersion, but a medium shear internal stirrer such as a colloid mill is used. Thus, a homogeneous dispersion can be obtained. Further, when colloidal silica is mixed with the dispersion, the viscosity of the dispersion can be reduced.

In the other colloidal silica, the particle surface is often negatively charged, but it is not preferable to use it in combination with alumina sol. This is because, when colloidal silica and alumina sol are mixed, the mixed dispersion liquid rapidly agglomerates, gels, and causes poor dispersion. Therefore,
It is preferable that the colloidal silica has a positively charged particle surface. As the binder component to be blended in the antifogging agent composition, it is necessary to select a binder component having a high affinity for a hydrophilic medium such as water or alcohol which is a dispersion of alumina sol or silica sol. Specifically, a surfactant having such hydrophilicity or a thermoplastic resin is used.

It is necessary to change the type of surfactant used depending on the silica sol or alumina sol. For example, in general, a combination of a negatively charged silica sol and a cationic surfactant and a combination of a positively charged silica sol and an anionic surfactant should be avoided. These combinations may cause gelation of the sol and aggregation / agglomeration of the antifogging agent composition.
Separation easily occurs, making application difficult. As the thermoplastic resin used as the binder component, acrylic resin, vinyl chloride-vinyl acetate resin, polyethylene resin, vinyl chloride resin, vinylidene chloride resin having a good affinity for a medium (usually water) as described above Resin, polyurethane resin, polycarbonate resin, styrene resin,
Examples thereof include a vinyl acetate resin and an unsaturated polyester resin, and an acrylic resin is particularly preferable.

The silica sol and / or alumina sol, which are the main components of the antifogging agent composition, preferably have a compounding amount in the range of 0.5 to 40 times the binder component in terms of solids weight ratio. If it is too high, not only does the anti-fogging effect not increase in proportion to the compounding amount, but also a phenomenon occurs in which the coating film formed after coating becomes cloudy and the light transmittance is reduced. Further, the coating film tends to be rough and brittle. On the other hand, if it is too low, it will be difficult to exhibit a sufficient antifogging effect. The anti-fogging agent composition may use a crosslinking agent for crosslinking the binder components together. By doing so, the water resistance of the anti-fog coating can be improved. As the crosslinkable compound, the same compounds as used in the above-mentioned antifogging coating composition can be used in the antifogging composition. The amount of the crosslinkable compound to be used is preferably in the range of 1 to 30% by weight, particularly preferably in the range of 0.5 to 10% by weight, based on the solid content of the binder component.

The anti-fogging composition may further contain an antifoaming agent, a lubricant, an antistatic agent and other various additives as required. Thus, the antifogging agent composition is usually used in a liquid form. The liquid dispersion medium includes an affinity or water-miscible solvent including water, and water; monohydric alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; polyhydric alcohols such as ethylene glycol, diethylene glycol, and glycerin; Cyclic alcohols of benzyl alcohols; cellosolve acetates;
And ketones. These may be used alone or in combination.However, the dispersion stability of the antifogging agent composition used in the present invention, the wettability after being applied to the film surface, the difficulty of removing the liquid dispersion medium, and the economical efficiency are improved. It is preferable to decide it by taking into consideration. 7. Dustproof coating component In a preferred embodiment of the present invention, an acrylic resin [D] and a vinylidene fluoride resin [E] as main components are provided on the surface of the film opposite to the surface on which the antifogging film is formed. To form a coating of the composition. 7-1 Acrylic resin [D] As a preferred embodiment of the acrylic resin used in the present invention, 1 to 30% by weight of an alkyl (meth) acrylate monomer represented by the following general formula (I), 50 to 50% of methyl methacrylate, 95% by weight, 4 to 30% by weight of a hydroxyalkyl (meth) acrylate compound, 0 to 20% by weight of an α, β unsaturated carboxylic acid having one or more carboxyl groups in a molecule, and copolymerizable therewith And copolymers obtained by copolymerizing a monomer mixture containing other vinyl monomers.

[0042]

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(In the formula, R1 represents a hydrogen or methyl group, and n represents an integer of 6 to 20.) The alkyl (meth) acrylate monomer represented by the general formula (I) (acrylic acid or methacrylic acid) Examples of the alkyl ester (the same applies hereinafter) include alkyl acrylates having 6 to 20 carbon atoms such as 2-ethylhexyl acrylate, decyl acrylate, lauryl acrylate, myristyl acrylate, and palmity acrylate, or 2-ethylhexyl acrylate,
Alkyl methacrylates having an alkyl group having 6 to 20 carbon atoms, such as decyl acrylate, lauryl acrylate, myristyl acrylate, and palmityl acrylate, are exemplified. These may be used alone or in combination of two or more. If the amount of the alkyl (meth) acrylate monomer is too large, dust resistance is undesirably reduced. If the amount of 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, a 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 too small, the solubility with an organic solvent cannot be sufficiently exhibited, and when it is too large, the cost increases. The effect obtained in comparison is not so large, which is not preferable. Α, β-unsaturated carboxylic acids having one or more carboxyl groups in the molecule include acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, aconitic acid, fumaric acid, crotonic acid, etc. Is mentioned.

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

7-2 Polymerization of Acrylic Polymer [D] A predetermined amount of a monomer band was blended, charged into a polymerization vessel together with an organic solvent, a polymerization initiator and, if necessary, a molecular weight regulator were added, and the mixture was 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 and 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. 7-3 Vinylidene fluoride resin [E] The vinylidene fluoride resin [E] of the present invention is a homopolymer of vinylidene fluoride, or vinylidene fluoride and another fluorine-containing unsaturated monomer and / or Copolymers with fluorine-free copolymerizable monomers and polymers obtained by modifying or modifying a part of these polymers are also included. These vinylidene fluoride resins can be used alone or in combination of two or more, and may be used as a mixture with another fluorine-containing resin such as tetrafluoroethylene, chlorotrifluoroethylene, or fluoroethylene. Absent. 7-4 Coating The blending amount of the acrylic polymer [D] and the vinylidene fluoride resin [E] is 5 to 50 parts by weight of [D] and 50 of [E].
９５95 parts by weight. Polymer [D] for resin [E]
Is too small, the adhesion of the formed film to the substrate surface is poor, and the film is easily peeled off, which is not preferable. On the other hand, if the ratio of the polymer [D] to the resin [E] is too large, the effect of preventing migration of a plasticizer and the like, stain resistance and water resistance of the formed film is insufficient, which is not preferable.

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.

8. Coating In order to form the above-mentioned anti-fog coating film and dust-proof coating film on the surface of the base film, a solution or dispersion of each composition is coated with a doctor blade coat method, a gravure roll coat method, an air knife coat method, a reverse roll coat method. Coating methods such as a coating method, a dip coating method, a curtain roll 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 of forming a film, as a method of drying a solvent when using a coating method,
For example, there are a natural drying method, a hot-air drying method, an infrared drying method, a far-infrared drying method, and the like. The hot-air drying method is advantageous in consideration of the drying speed and safety. The temperature condition in this case is 50 ° C.
The temperature is in the range of 200 ° C., and the time is preferably selected from 10 seconds to 15 minutes.

In the present invention, the thickness of the film 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 subjected to another paint or primer. May be subjected to a pretreatment such as undercoating. The order of forming the antifogging film and the dustproof film on the substrate is determined in consideration of heating conditions and the like. When the polyvinyl chloride resin film for agriculture according to the present invention is actually used for agriculture, it is preferable to stretch the film so that the side provided with the anti-fog coating is inside the house or tunnel.

[0053]

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 1-4, 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 the types and amounts of organic phosphates or metal organic phosphates shown in Table 3 were prepared. Salt, light stabilizer and UV 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 0.15 mm.

II. Preparation of acrylic polymer [D] 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 Film of Dust-Proof Composition Acrylic polymer [D] of the kind and amount shown in Table 4 and commercially available vinylidene fluoride resin [E] were blended, and the solid content was 20% by weight. Was added to obtain a coating composition. The coating composition was applied to one surface of the substrate film prepared by the above method using a # 5 bar coater. The applied film was kept in an oven at 130 ° C. for 1 minute to evaporate the solvent. The amount of coating on each of the obtained films was about 3 g /
m ² .

IV. Formation of Coating of Antifogging Agent Composition The main components (colloidal silica and / or alumina sol) shown in Table 5, a binder component, a crosslinking agent and a liquid dispersion medium were blended to obtain an antifogging agent composition. The above antifogging agent composition was continuously applied to the other surface of the base film on which the fluororesin coating was formed by a roll coating method, and then dried in a drying oven.
The mixture was kept at 0 ° C. for 1 minute to volatilize the liquid dispersion medium, and each film was wound. The amount of coating on each of the resulting films is
It was about 1 g / m ² . V. Evaluation of Film The performance of the film was evaluated by the following method, and the results are shown in Table 5. 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 line transmittance ◎: The transmittance is 85% or more. …: Transmittance of 65% to 84%. Δ: transmittance of 45% to 64%. ×: transmittance is less than 45%.

Adhesion evaluation (acceleration test) 300 cc of water (50 ° C.) was placed in a 500 cc beaker, and the beaker was coated with the sample so that the surface on which the coating was formed was inside the beaker. ° C), tilt the beaker 10 degrees off the ground and 2/3 from the bottom
And left in a constant temperature room at 25 ° C. for 7 hours.
Using the obtained film, a cellophane tape was adhered to the surface on which the coating was formed, and when the cellophane tape was peeled off,
The state of peeling of the coating was visually observed. The evaluation criteria are as follows. ◎: The film did not peel off at all and remained completely. …: A part (less than 1/3) of the coating peeled off. Δ: One-third or more and less than two-thirds of the coating peeled off. X: Two-thirds of the coating peeled off.

Low temperature physical properties Impact strength: The films obtained in Examples and Comparative Examples
Prepare 9 samples of mx10cm, JIS B-7
The thickness at the center of the sample is measured with a dial gauge specified in 503. The above samples were measured in a room at -15 ° C with a puncture manufactured by Toyo Seiki Co., Ltd. Impact strength = measured value (impact value) / measured thickness x nominal thickness

Outdoor extension test Nine kinds of films were installed in a roof-type house (opening 3 m, depth 5 m, building height 1.5 m,
(The roof slope was 30 degrees), and the coated side was covered with the house side, and a two-year expansion test was conducted from March 1997 to February 1999. The stretched film was evaluated for the residual elongation after weather resistance of the film and the impact strength at low temperature of the film by the following methods. Tests and evaluations were carried out in the same manner as those conducted for I) appearance, adhesion, and low-temperature physical properties. II) Dustproofness The value calculated by the following equation was judged based on 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. III) Anti-fog property After rolling the film, wind up the side of the film during the day and seal the film in the evening, then visually observe the state of water droplets adhering to the ceiling and the inside of each rolled-up part with time with the naked eye. did. The evaluation criteria are as follows. ◎… Film surface (facing inside the house, the same applies hereinafter)
Water droplets adhering to each other are united and spread in a thin film shape, and the area of the thin film portion is less than 2/3, 1/2 or more of the film surface. Light transmittance after expansion of 90% or more before expansion. …: Water droplets adhering to the film surface are coalesced, but the area of the thin film portion is less than １ ／ of the film surface. Δ: Coalescence of water droplets adhering to the film surface is recognized, but the shape of the thin film portion is not recognized. ×: No coalescence of water droplets adhering to the film surface is observed. IV) Adhesion test A cellophane tape was adhered to the surface on which the film was formed using the film collected after the outdoor spreading, and when the cellophane tape was peeled off, the state of peeling of the film was visually observed. The evaluation criteria are as follows. ◎: The film did not peel off at all and remained completely. …: A part (less than 1/3) of the coating peeled off. Δ: One-third or more and less than two-thirds of the coating peeled off. X: Two-thirds of the coating peeled off.

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3]

[0064]

[Table 4]

[0065]

[Table 5]

[0066]

[Table 6]

[0067]

[Table 7]

[0068]

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) Even if the vinyl chloride resin film for agricultural use according to the present invention is stretched outdoors for a long period of time, the degree of discoloration, reduction in mechanical properties, and reduction in dust resistance are small, and it can withstand long-term use. (3) The agricultural vinyl chloride resin film according to the present invention has excellent physical properties at low temperatures.

(4) The agricultural vinyl chloride resin film according to the present invention has a film derived from the antifogging agent composition formed on one surface of the film. When expanded to the inside of the house, it functions to suppress the adhesion of water droplets, and the anti-fog effect lasts for a long time.

Incidentally, in the vinyl chloride resin film for agricultural use according to the present invention, the internal stress relaxation effect and the increase in molecular entanglement by mixing chlorinated polyethylene bring about an improvement in physical properties at low temperatures. Further, by suppressing the bleeding of additives such as a plasticizer and having a specific dust-proof coating, an effect of suppressing a decrease in dust-proof property is brought out. As described above, the agricultural polyvinyl chloride resin film of the present invention is excellent in low-temperature properties, dust resistance and anti-fogging properties.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Murakami Ichizuka Okaike, Nagoya-shi, Nagoya-shi, Aichi, Japan 2 Nagoya Office, Mitsubishi Chemical MKV Co., Ltd. Address Mitsubishi Chemical MKV Corporation Nagoya Office F-term (reference) 2B024 DB01 DB07 2B029 EB03 EB16 EC04 EC06 EC09 EC17 EC19 RA03 4F100 AA19B AA20B AK01B AK04A AK15A AK19C AK24C AK24J AK25A07CA01 BA07A01 BA07A01 JK10 JL00 JL07B JM01B YY00A YY00B YY00C

Claims (9)

[Claims] 1. A vinyl chloride resin obtained by mixing 0.5 to 20 parts by weight of a chlorinated polyethylene [B] and 30 to 60 parts by weight of a plasticizer [C] with respect to 100 parts by weight of a vinyl chloride resin [A]. On one or both sides of the film, silica sol and / or
Alternatively, a vinyl chloride resin film for agricultural use, wherein a film derived from an antifogging agent composition containing alumina sol and a thermoplastic resin is formed. 2. The chlorinated polyethylene [B] has a chlorine content of 15 to 50% by weight and a melt index of 0.5 to 1
The agricultural polyvinyl chloride resin film according to claim 1, wherein the film has a crystallinity of 50 g / 10 minutes and a crystallinity of 0 to 30%. 3. The agricultural polyvinyl chloride according to claim 1, wherein the silica sol and / or the alumina sol are contained in a weight ratio of solid content of 0.5 to 40 times the thermoplastic resin. Resin film. 4. A film formed of a composition mainly composed of an acrylic resin [D] and a vinylidene fluoride resin [E] on the other surface of the film. A vinyl chloride resin film for agricultural use according to any one of claims 3 to 3. 5. The acrylic resin [D] has the general formula [I]:
An alkyl (meth) acrylate monomer 1 represented by
30% by weight, methyl methacrylate 50-95% by weight,
4 to 30% by weight of a hydroxyalkyl (meth) acrylate, 0 to 20% by weight of an α, β-unsaturated carboxylic acid containing one or more carboxyl groups in a molecule, and the remainder copolymerizable with these compounds 5. A vinyl chloride resin film for agricultural use according to claim 4, which is a resin obtained by copolymerizing a monomer component comprising another vinyl compound. Embedded image (In the formula, R1 represents a hydrogen or methyl group, and n represents an integer of 6 to 20.) 6. The vinyl chloride resin film for agricultural use according to claim 4, wherein the component [D] is 5 to 50 parts by weight and the component [E] is 50 to 95 parts by weight. 7. The vinyl chloride resin has an average degree of polymerization of 100.
The vinyl chloride resin film for agriculture according to any one of claims 1 to 6, wherein the film is a vinyl chloride resin having a size of 0 or more and 2500 or less. 8. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin film contains an acrylic copolymer. 9. The agricultural vinyl chloride resin film according to claim 1, wherein the vinyl chloride resin film contains a light stabilizer and / or an ultraviolet absorber.