JPH074119B2 - Vinyl chloride resin film for agriculture - Google Patents

Description

The present invention relates to a vinyl chloride resin film for agriculture. More specifically, the present invention relates to a vinyl chloride resin film for agriculture, which is excellent in the ability to suppress the fog generation phenomenon in the vicinity of the inner surface of the covering material (this ability is called anti-fog property) for a long period of time. Is.

"Conventional technology" In recent years, in order to increase the productivity and marketability of useful plants, under the coating with agricultural coating materials such as agricultural vinyl films,
So-called greenhouse cultivation and tunnel cultivation, in which useful plants are forcibly, semi-forcibly or restrainedly cultivated, are actively carried out. In this greenhouse cultivation or tunnel cultivation, most of vinyl chloride resin films currently used are the inner surface of the covering material (the surface facing the inside of the greenhouse or the house).
In order to accelerate the flow of water droplets and increase the amount of incident sunlight, an antifogging agent (mainly sorbitan fatty acid ester; glycerin fatty acid ester, etc.), which is a kind of surfactant, is included. Under the coating of the coating material containing such an antifogging agent, when the temperature difference between the inside and outside of the coating material becomes large,
A phenomenon in which fog is generated near the inner surface of the coating material is often observed.

This fog phenomenon often occurs in late autumn or winter, which is most important for greenhouse cultivation such as greenhouse cultivation and tunnel cultivation. The cause of the fog phenomenon is not exactly known, but the temperature and humidity inside the house or tunnel, the temperature of the soil inside the house or tunnel, the water content, the amount of solar radiation to the house or tunnel, and the hydrophilicity of the wetted surface of the covering material. The humidity in the house or tunnel adheres to the surface of the coating material smoothly due to temperature changes, and the flowing phenomenon does not occur, and some moisture becomes mist near the inner surface of the coating material. It is presumed to be due to this.

According to the observation of the present inventors, such a fog generation phenomenon is
It was found that it occurs near the ground surface in the house or tunnel, near the cultivated plants, and near the inner surface of the covering material. Furthermore, the covering material and the inner surface of the covering material are cooled by a decrease in the outside air temperature, a temperature difference is generated between the inside of the house, and the warm and moist air inside the house moves to the vicinity of the inside surface of the covering material by natural convection, It was found that the water vapor that could not be contained in the air condense into minute water droplets, became mist, and spread into the house or tunnel by natural convection. If the once generated mist-like water droplets evaporate and disappear again during natural convection, the mist will not spread inside the house or tunnel, but if the evaporation disappearance speed is slow, the entire house or tunnel will disappear. It was also found to be a thick fog.

Such a fog generation phenomenon wets leaves, stems, flowers, fruits, etc. of useful crops cultivated in a house or a tunnel, and causes disease occurrence or helps spread disease occurrence. Further, when the cultivated crop gets wet, the heat required for drying is required, which causes disadvantages such that more fuel is required for heating the house or tunnel. In addition, the visibility inside the house deteriorates, and there is also a problem that the efficiency of agricultural work decreases.

In order to eliminate such disadvantages, conventionally, in order to soften the temperature change in the house or tunnel as much as possible, a colored agricultural synthetic resin film is used or the soil in the house or tunnel is covered with a mulching film. To reduce the amount of water evaporation, improve the irrigation time (for example, irrigate after late in the evening, adjust the irrigation part and irrigation amount), improve the irrigation method and device, etc. The measures have been taken. However, neither method is effective in completely suppressing the fog generation phenomenon.

As a technique for improving such a defect, Japanese Patent Application Laid-Open No. 57-14648
As described in the publication, a method has been proposed in which a surfactant as an antifogging agent and a fluorine-based surfactant for improving the fog resistance are used in combination. Further, JP-A-59-80468 proposes a method for improving the fog-proof property by blending a copolymerization oligomer of an acrylate or methacrylate containing a terminal polyfluoroalkyl group and another copolymerizable compound. Has been done.

[Problems to be solved by the invention] However, according to the experiments of the present inventors, when an antifogging agent and a fluorine-based surfactant or a copolymerization oligomer are further used in combination, the vinyl chloride resin coating for agriculture is coated. It may have an adverse effect on the antifogging property which is an essential performance as a material, and the antifogging property does not deteriorate so much even when used in low temperature winter, but when it is used from high temperature summer or early autumn, It was found that the deterioration of the antifogging property is promoted and the antifogging durability may be significantly deteriorated. Although it is possible to reduce the adverse effect on the antifogging property by using a small amount of a fluorine-based surfactant, etc., the effect of suppressing fog generation is not satisfactory, and especially when used for a long time The deterioration of sex is remarkable.

"Means for Solving the Problem" Under the circumstances, the present inventors have made a vinyl chloride resin coating material for agricultural use that exhibits antifog properties for a long period of time without lowering antifogging sustainability. As a result of diligently studying for the purpose of providing, even when a small amount of a fluorine-based surfactant or the like is blended, by blending together with a benzotriazole derivative having a chlorine group, it is possible to prevent fog without impairing antifogging property. The present invention has been completed by discovering that the properties are exhibited for a long period of time.

However, the gist of the present invention is that the antifogging agent comprising a sorbitan surfactant is 1.5 to 5 parts by weight and the fluorine-containing compound is 0.01 to 0.5 per 100 parts by weight of a vinyl chloride resin.
A vinyl chloride resin film for agricultural use, comprising 1.0 part to 5.0 parts by weight of an o-hydroxyphenylbenzotriazole derivative having a chlorine group represented by the following general formula (1).

(In the formula, R ¹ and R ² represent a hydrogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms, Y ¹ represents a hydrogen atom or a chlorine atom, and Y ² represents chlorine. Represents an atom.) The present invention is described in detail below.

In the present invention, the vinyl chloride resin refers to polyvinyl chloride, a copolymer of vinyl chloride as a main component with another comonomer, a mixture thereof, or a mixture of these with another polymer or copolymer.

The sorbitan-based surfactant used as the antifogging agent in the present invention is preferably sorbitan monopalmitate, sorbitan monostearate or an alkylene oxide adduct thereof. The amount of the antifogging agent to be added to the base resin can be the same as that used for the conventional agricultural vinyl chloride resin film, and is 1.5 to 100 parts by weight of the vinyl chloride resin base material. It can be in the range of 5 parts by weight.

In the present invention, the fluorine-containing compound may be a conventionally used fluorine-based surfactant or a carbon number of 4 to 4
Copolymerized oligomers of unsaturated esters containing 20 polyfluoroalkyl groups with other copolymerizable compounds can be used.

Examples of the fluorine-based surfactant include compounds represented by the following general formula.

RfCONH (C ₂ H ₄ O) nH RfSO ₂ NH (C ₂ H ₄ O) nR (In the formula, Rf represents a linear or branched polyfluoroalkyl group, R represents an alkyl group, and n represents a natural number.) As the polyfluoroalkyl group contained in the fluorine-containing compound used in the present invention Is preferably one having 6 to 12 carbon atoms.

Examples of the copolymerization oligomer include the followings.

Copolymer Oligomer (1) CF ₃ (CF ₂ ) ₇ SO ₂ N (CH ₃ ) (CH ₂ ) ₂ OCOC (CH ₃ ) = CH ₂ and CH ₃ OCOCH = CH ₂ and HO (CHCHO) ₅ OCOCH = CH ₂ Polymerized with and at a charge weight ratio of 1: 0.5: 0.5, a copolymerized oligomer having a molecular weight of about 4000 Copolymerized oligomer (2) CF ₃ (CF ₂ ) ₆ (CH ₂ ) ₂ OCOC (CH ₃ ) = CH ₂ And C ₂ H ₅ OCOCH = CH ₂ and HO (CHCHO) ₂ OCOCH = CH ₂ were polymerized at a charge weight ratio of 1: 0.1: 1.5. Copolymerization oligomer having a molecular weight of about 4000 Copolymerization oligomer (3) CF ₃ (CF ₂ ) ₈ CONH (CH ₂ ) ₂ OCOC (CH ₃ ) = CH ₂ and CH ₃ OCOCH = CH ₂ and HO (CHCHO) ₁₀ OCOCH = CH ₂ with a charge weight ratio of 1: 1: 1 Copolymerized oligomer with a molecular weight of about 2000, copolymerized oligomer (4) CF ₃ (CF ₂ ) ₈ (CH ₂ ) ₂ OCOCH = CH ₂ and C ₃ H ₇ OCOCH = CH ₂ and HO (CHCH
O) ₃ OCOCH = CH ₂ was polymerized at a charge weight ratio of 1: 0.1: 1. Copolymerization oligomer having a molecular weight of about 2000 Copolymerization oligomer (5) And C ₂ H ₅ OCOCH = CH ₂ and HO (CHCHO) ₃ OCOCH = CH ₂ were polymerized at a charge weight ratio of 1: 0.2: 1, and a copolymerization oligomer having a molecular weight of about 6000 was used in the present invention. The compounds can be used alone or in combination of two or more kinds. The blending amount of this fluorine-containing compound in the vinyl chloride resin coating material can be changed according to the type of fluorine-containing compound to be blended, the type of base vinyl chloride resin, etc.
Parts by weight (however, the plasticizer is not included in the calculation. The same applies hereinafter)
In each case, 0.01 parts by weight or more and 0.5 parts by weight or less are sufficient,
The preferred range of blending amount is 0.02 to 0.2 parts by weight.

The o-hydroxyphenylbenzotriazole derivative having a chlorine group represented by the general formula (1) in the present invention is specifically, for example, 2- (2'-hydroxy-5'-methylphenyl) -5. , 6-Dichlorobenzotriazole, 2- (2'-hydroxy-5'-t-butylphenyl) -5-chlorobenzotriazole, 2-
(2'-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl)
-5-chlorobenzotriazole, and the like.

The amount of these benzotriazole derivatives added to the base resin can be in the range of 1.0 to 5.0 parts by weight.

Vinyl chloride resin base material constituting the agricultural vinyl chloride resin film according to the present invention, if necessary, various ordinary resin additives, for example, plasticizers, lubricants, heat stabilizers, light stabilizers, oxidation Inhibitors, colorants and the like can be included in conventional amounts.

Suitable plasticizers that can be used include, for example, phthalic acid derivatives such as di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate, diisodecyl phthalate, didodecyl phthalate and diundecyl phthalate; and diisooctyl phthalate. Isophthalic acid derivative; adipic acid derivative such as di-n-butyl adipate, dioctyl adipate; maleic acid derivative such as di-n-butyl maleate; citric acid derivative such as tri-n-butyl citrate; itacone such as monobutyl itaconate Acid derivatives; oleic acid derivatives such as butyl oleate; ricinoleic acid derivatives such as glycerin monoricinoleate; tricresyl phosphate, epoxidized soybean oil, and epoxy resin plasticizers.

Examples of the lubricant or heat stabilizer include polyethylene wax, liquid paraffin, methylenebis higher fatty acid amide, stearic acid, zinc stearate, aliphatic alcohol, calcium stearate, barium stearate,
Examples thereof include barium ricinoleate, dibutyltin dilaurate, dibutyltin dimaleate, organic phosphate metal salts, organic phosphite compounds, phenols and β-diketone compounds.

As the light stabilizer, various compounds usually blended in agricultural vinyl chloride films can be used. Specifically, for example, 4-acetoxy-2,2,6,6-tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidyl) adipate, tris (2,2,6,6) -Tetramethyl-4-piperidyl) benzene-1,3,5-tricarboxylate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) propane-1,1,2,3-tetracarboxylate And the like.

Examples of the antioxidant include 2,6-di-tert-butyl-4-methylphenol, 2,2'-methylenebis (6-tert-butyl-4-ethylphenol), dilaurylthiodipropionate and the like. You can

Examples of colorants include phthalocyanine blue, phthalocyanine green, Hansa yellow, alizarin lake, titanium oxide, zinc white, ultramarine blue, permanent red,
Examples thereof include quinacridone and carbon black.

These resin additives may be contained in a usual amount, for example, a small amount of 10 parts by weight or less per 100 parts by weight of the vinyl chloride resin base material.

The vinyl chloride-based resin as the base material, in order to compound the antifogging agent and the fluorine-containing compound and the benzotriazole derivative and further various resin additives, the usual compounding techniques, mixing techniques such as ribbon blender, Banbury mixer, It can be mixed with a super mixer or other blender. To form the vinyl chloride resin into a film, a method known per se, for example, a melt extrusion method, a solution casting method, a calender method or the like may be adopted.

The thickness of the vinyl chloride resin film for agriculture according to the present invention is not preferable because the strength is insufficient when it is too thin, and on the contrary, when it is too thick, it is made into a film, and then the film is handled (the film is cut and bonded to a house type). Since it causes inconvenience to work, including work to spread to a house, etc.), it is preferable to set it in the range of 0.03 to 0.2 mm.

Further, the agricultural vinyl chloride resin film according to the present invention,
It can be spread in agricultural and horticultural facilities such as houses and tunnels and used for cultivating useful plants in the same manner as conventionally used agricultural covering materials.

"Effects of the Invention" The agricultural vinyl chloride resin film according to the present invention has particularly remarkable effects as described below, and its industrial utility value is extremely large.

(1) In a house or tunnel in which the agricultural vinyl chloride resin film according to the present invention is spread, as is apparent from the examples described below, generation of fog in the vicinity of the inner surface of the film is effectively suppressed, and long-term use Even so, there is little deterioration in fog resistance. Its inhibitory effect is extremely strong, and even in the late autumn or winter when it was said that fog frequently occurs in the past, it is possible to substantially completely suppress the fog generation, and it has a remarkable effect in preventing disease occurrence and transmission of useful plants. is there. Therefore,
There is no need to pay close attention to irrigation as in the past.

(2) The agricultural vinyl chloride resin film according to the present invention is excellent not only in the effect of suppressing fog generation but also in antifogging property and antifogging sustainability, and is useful for facility cultivation of useful plants.

Hereinafter, the present invention will be described in detail based on Examples,
The present invention is not limited to the following examples unless it exceeds the gist.

Examples 1 to 3, Comparative Examples 1 to 3 Polyvinyl chloride (degree of polymerization = 1300) 100 parts by weight Dioctyl phthalate 45 〃 Tricresyl phosphate 5 〃 Epoxy resin 2 〃 Ba-Zn type liquid stabilizer 2 〃 Ba-Zn The powdery powder stabilizer 1 〃 was used as a basic composition, and the antifogging agent shown in Table 1 and a fluorine-containing compound and an o-hydroxyphenylbenzotriazole derivative having a chlorine group were mixed and mixed with a super mixer. The mixture was supplied to a calender molding machine heated to 180 ° C. and formed into a film by an ordinary method to prepare seven kinds of film having a thickness of 0.1 mm.

The fog generation test and the antifogging property were evaluated by the following methods for the above seven kinds of films.

The results are shown in Tables 2 and 3.

(1) Fog generation test Six pipe houses with a frontage of 5.4 m, a building height of 3 m, and a depth of 15 m were constructed in a field of Isshi group in Mie prefecture, and each building was coated with one of the above films. The evaluation of the degree of fog was conducted for 5 days after the coating of the film on the pipe house for 5 days (October 30th to November 3rd, 1989) and for 5 days after the coating of the pipe house for 4 months (1990). January 29-February 2) and 6 days after coating, 5 days (March 26-March 30, 1990).

The numerical values of "evaluation of fog generation" have the following meanings.

“1”: No fog was found in the house, or only a small amount was generated near the inner surface of the film.

"2" ... Fog is generated over the entire house, but the interior of the house 15m ahead can be clearly identified.

"3" ... The fog was generated in the entire house, and the inside of the house 15m ahead could not be clearly identified.

“4”… The fog is heavily generated over the entire house, and the back of the house 15 m ahead cannot be identified at all.

The value obtained by averaging the numerical values of the five days during which the fog generation situation was observed is the second
Shown in the table.

(2) Evaluation of anti-fog property In a field in Nagoya City, Aichi Prefecture, the above 6 kinds of films were applied to a single roof house with a frontage of 2 m, a building height of 2 m and a depth of 30 m in September 1989.
On 22nd and another house of the same type on October 27, 1989, the antifogging property of each film was visually observed and evaluated. The results are shown in Table 3.

The numerical values of "evaluation of antifogging property" have the following meanings.

“1”: Water adhered in a thin film and no water droplets were observed.

“2”: Water is adhering in a thin film, but slightly large droplets are observed.

"3" ... A state in which the adhesion of fine water droplets is partially recognized.

"4" ... A state in which fine water droplets are observed to adhere to the entire inner surface of the film.

Claims (1)

[Claims] 1. An antifogging agent consisting of a sorbitan surfactant is added in an amount of 1.5 to 5 parts by weight per 100 parts by weight of a vinyl chloride resin.
A vinyl chloride resin film for agriculture, which comprises 0.01 to 0.5 parts by weight of a fluorine-containing compound and 1.0 to 5.0 parts by weight of an o-hydroxyphenylbenzotriazole derivative having a chlorine group represented by the following general formula (1). . (In the formula, R ¹ and R ² represent a hydrogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms, Y ¹ represents a hydrogen atom or a chlorine atom, and Y ² represents chlorine. Represents an atom.)