JPS61152745A - Synthetic resin coating material for agricultural use - Google Patents

Abstract

PURPOSE:To produce the titled coating material having antifogging property near the inner surface of the coating agent and excellent durability of the anticlouding property, and suitable for the cultivation of useful plants, by compounding a specific fluorine-containing compound with an antifogging agent. CONSTITUTION:100pts.(wt.) of a synthetic resin (e.g. polyvinyl chloride) is mixed with (A) 0.01-2pts., preferably 0.02-1pt. of the fluorine-containing compound of formula I and/or formula II (Rf is 4-20C polyfluoroalkyl; R is H, 1-10C alkyl, etc.; n and m are 1-20) and (B) 1-5pts., preferably 1.5-3.5pts. of an antifogging agent other than the component A (e.g. nonionic surfactant) and the mixture is formed in the foam of a film.

Description

[Detailed description of the invention] "Technical field to which the invention belongs" The present invention relates to synthetic resin covering materials for agriculture.

More specifically, the ability to suppress fog generation near the inner surface of the coating material (this ability is...

It is called fog proof. ) and the ability to exhibit excellent anti-fog effects over a long period of time (this ability is referred to as anti-fog persistence).

[Prior Art] In recent years, in order to increase the productivity and marketability of useful plants, they are covered with agricultural covering materials such as agricultural vinyl film.
2. Description of the Related Art So-called greenhouse cultivation and tunnel cultivation, in which useful plants are cultivated under forced, semi-forced or suppressed conditions, are widely practiced.

In greenhouse cultivation and tunnel cultivation, most of the synthetic resin covering materials currently used, such as vinyl chloride resin films, are coated on the inner surface of the covering material (the surface facing the inside of the greenhouse or tunnel, hereinafter the same). , ) contains an antifogging agent (mainly sorbitan fatty acid ester; glycerin fatty acid ester, etc.), which is a type of surfactant, in order to promote the flow of water droplets and increase the amount of sunlight incident. When covered with a coating material containing such an antifogging agent, the temperature difference between the inside and outside of the coating material becomes large, so 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 the most important period for greenhouse cultivation, tunnel cultivation, and other facility cultivation. What is the cause of the N generation phenomenon?

I don't know exactly, but the temperature inside the house or tunnel,
Humidity, temperature of the soil inside the house or tunnel, water content, amount of solar radiation to the house or tunnel, degree of hydrophilicity of the wet surface of the covering material, etc. all interact subtly, and the humidity inside the house or tunnel causes temperature changes. It is presumed that this is because the moisture adheres smoothly to the surface of the coating material and does not flow, and some of the moisture becomes atomized near the inner surface of the coating material.

According to the observations of the present inventors, such a fog generation phenomenon is caused by
It has been found that this occurs near the ground surface in greenhouses or tunnels, near cultivated plants, and near the inner surface of covering materials. Furthermore, the coating material and the inner surface of the coating material are cooled by the decrease in outside temperature,
This creates a temperature difference between the inside of the house and the inside of the house, making it warmer.

When moist air moves near the inner surface of the coating material due to natural convection, water vapor that cannot be contained in the air
It was found that the water condenses into reduced water droplets, forms a mist, and spreads inside the house or tunnel through natural convection. If the mist-like minute water droplets that are once generated evaporate and disappear again during natural convection, the fog will not spread into the house or tunnel, but if the rate of evaporation and disappearance is slow, the entire house or tunnel will disappear. It also turned out to be a thick fog.

Such fog generation phenomenon wets the leaves, stems, flowers, fruits, etc. of useful crops grown in greenhouses or tunnels, causing the occurrence of diseases or even aiding the spread of diseases. Also, if the cultivated crops become wet, the heat necessary to dry them is required, which causes disadvantages such as the need for more fuel for heating the greenhouse or tunnel. Furthermore, since the visibility inside the greenhouse becomes poor, there are also disadvantages such as a decrease in the efficiency of agricultural work.

To overcome these disadvantages, conventional methods have been to use colored agricultural synthetic resin films to soften temperature changes inside greenhouses and tunnels, and to cover the soil inside greenhouses and tunnels with mulching films. To reduce the amount of water evaporation, improve the irrigation time (for example, watering later in the evening, adjust the area and amount of water to be watered, etc.), improve the irrigation method and equipment, etc. measures have been taken. However, none of these methods was effective in completely suppressing the fog generation phenomenon.

As a technique to improve such drawbacks, Japanese Patent Application Laid-Open No. 57-1
As described in Japanese Patent No. 4848, a method has been proposed in which a surfactant as an antifogging agent and a fluorine-containing surfactant to improve antifogging properties are used in combination. For example, it has been found that not all fluorine-containing surfactants exhibit fog-proofing properties, and even compounds that exhibit fog-proofing properties may have an adverse effect on the durability of the film's anti-fogging properties.

[Problems sought to be solved by the invention] Under such circumstances, the present inventors have discovered that the coating material has the ability to suppress the fog generation phenomenon near the inner surface (fog-proof property) and has excellent anti-fog durability. As a result of intensive studies aimed at providing synthetic resin covering materials for agriculture, the present invention has been completed.

[Means for Solving the Problems] The gist of the present invention is to provide a fluorine-containing compound represented by the following general formula (I) and/or (■), and a fluorine-containing compound represented by the following general formula (I) or (II). ) An agricultural synthetic resin coating material characterized by containing an antifogging agent other than those represented by:

General formula: [In (I) and (II), Rr is a polyfluoroalkyl group having 4 to 20 carbon atoms, and R is H1 having 1 carbon number and 1 to 1 prime number.
0 alkyl groups), n is synonymous with 1~
It is an integer of 20.

] Hereinafter, the present invention will be explained in detail.

The synthetic resin material constituting the agricultural synthetic resin coating material of the present invention generally includes film-forming thermoplastic synthetic resins. Specifically, monomers such as vinyl chloride, ethylene, propylene, acrylic esters, methacrylic esters, etc. alone or copolymers of these monomers, or at least one of these monomers and other copolymers are possible. Examples include copolymers with monomers (eg, vinyl acetate, vinylidene chloride, etc.), fluororesins, polyesters, polyamides, etc., and blends of these polymers. Among these, vinyl chloride resins (i.e. polyvinyl chloride and its copolymers containing 50% by weight of vinyl chloride) and ethylene resins (i.e. , polyethylene and its copolymers containing 50% or more by weight of ethylene) are preferred, most preferably polyvinyl chloride.

In the present invention, the general formula (I) and/or (
Specific examples of the fluorinated metal represented by II) are as follows.

? H3 GHCH20 (PO group) and CH2CH2 as above
In addition to 0 (EO group) bonded in a block shape, P
It may be one in which O groups and EO groups are randomly bonded.

The above specific examples of fluorine-containing compounds do not limit the present invention.

The fluorine-containing compounds represented by general formulas (I) and (■) are:
Each can be used alone, or two or more types can be used in combination. The amount of this fluorine-containing compound added to the synthetic resin coating material can be varied over a wide range depending on the type of fluorine-containing compound to be blended, the type of base synthetic resin, etc. Generally, base synthetic resin 1
It can be at least 0.01 part by weight per 0.00 parts by weight (however, plasticizers are not included in the calculation, the same shall apply hereinafter), and the upper limit of the blended amount is not strictly limited, but If a large amount is added, there is a risk of bleed-out or clouding, so 2.0 parts by weight or less is usually sufficient. The preferred range of blending amount is 0.02 to 1.0 parts by weight per 100 parts by weight of the synthetic resin material.

Taking these into account, the resin material is blended with an antifogging agent that has been conventionally used in the field of agricultural vinyl chloride resin films in order to impart antifogging properties to the uninvented agricultural cover material. Therefore, the antifogging agent that can be used in the present invention refers to antifogging agents other than those represented by the above general formulas (I) and (II).

Specific examples of antifogging agents that can be used include polyhydric alcohols such as sorbitol, mannitol, glycerin, polyglycerin, pentaerythritol, and trimethylolpropane, and non-fogging agents derived from fatty acids having 10 to 22 carbon atoms. Examples include ionic surfactants and nonionic surfactants derived from the above-mentioned polyhydric alcohols, fatty acids, and fullkylene oxide. Carbon number 10-22
The fatty acids may be either straight-chain or branched-chain fatty acids.

More specifically, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, behenic acid,
In addition to fatty acids such as oleic acid, examples include beef tallow, rapeseed oil, corn oil, soybean oil, cottonseed oil, palm oil, sesame oil, linseed oil, fatty acids obtained from these hydrogenated oils, and mixed fatty acids thereof.

Examples of alkylene oxide include ethylene oxide,
Examples include propylene oxide, butylene oxide, and phenylene oxide. In addition, the alkylene oxide may be added by adding fullylene oxide to the polyhydric alcohol and then esterifying the fatty acid, or by esterifying the polyhydric alcohol and the fatty acid and then adding the alkylene oxide. Two or more kinds of alkylene oxides may be added.

The antifogging agent also exhibits antifogging properties even during the low temperature period of winter, and is not extracted from the coating material even during the high temperature period described below.
It is best to choose from among those that maintain anti-fog properties for a long period of time. Examples of polyhydric alcohols that exhibit such long-term anti-fog properties include sorbitol, mannitol, and polyglycerin with a degree of condensation of 2 to 1O. Fatty acid has 18 to 18 carbon atoms
Examples include nonionic surfactants derived from the above fatty acids, or nonionic surfactants derived from the above polyhydric alcohols, fatty acids, and ethylene oxide or propylene oxide. In addition, among nonionic surfactants, during the esterification reaction of polyhydric alcohol and fatty acid, the number of water molecules released by the intramolecular dehydration condensation reaction of polyhydric alcohol is 2 water molecules per molecule of polyhydric alcohol. The following are preferable. Furthermore, the content of diester in the ester mixture obtained by the reaction of polyhydric alcohol and fatty acid is preferably 20 to 80% by weight of the total weight. In addition, ethylene oxide and/or Most preferred are nonionic surfactants in which the total amount of propylene oxide added is 5 moles or less per mole of polyhydric alcohol.

The blending amount of the base resin of the antifogging material can be the same as that used for conventional agricultural synthetic resin films. In general, the synthetic tree rW1 part 100 yen is 1 to 5 yen, preferably 1.5 yen.
-3.5 parts by weight.

The synthetic resin base material constituting the agricultural covering material according to the present invention may also contain various conventional resin additives, such as plasticizers, lubricants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, Dyes and the like can be included in conventional amounts.

For example, regarding the soft vinyl chloride resin suitable for the present invention, about 30 to 70 parts of plasticizer is added to 100 parts by weight of polyvinyl chloride having a degree of polymerization of about 1000 to 2000.
It can be blended in parts by weight. Suitable plasticizers that can be used include, for example, di-n-octyl phthalate, di-2
-ethylhexyl phthalate, dibenzyl phthalate,
Isophthalic acid derivatives of phthalic acid such as diisodecyl phthalate, didodecyl phthalate, and diisodecyl phthalate; Isophthalic derivatives such as diisooctyl phthalate;
Adipic acid derivatives such as di-n-butyl adipate and dioctyl adipate; maleic acid derivatives such as di-n-butyl maleate; citric acid derivatives such as tri-n-butyl citrate; itaconic acid derivatives such as monobutyl itaconate; butyl oleate, etc. Oleic acid derivatives: ricinoleic acid derivatives such as glycerin monocitrate; other examples include tricresyl phosphate, trixyl phosphate, epoxidized soybean oil, and epoxy resin plasticizers.

In addition, examples of lubricants or heat stabilizers that can be included in the synthetic resin base material include polyethylene wax, bisamide,
Examples include stearic acid, zinc stearate, barium stearate, calcium stearate, barium ricinoleate, and the like. Examples of the ultraviolet absorber include benzotriazole-based, benzoate-based, benzophenone-based, cyanoacrylate-based, and phenylsalicylate-based ultraviolet absorbers. In addition, as pigments and dyes,
Examples include titanium oxide, silica, ultramarine blue, and phthalocyanine blue.

These resin additives may be contained in a small amount of 5 parts by weight or less per 100 parts by weight of the synthetic resin base material.

In order to incorporate a fluorine-containing compound, an antifogging agent, and, if necessary, various resin additives into the base synthetic resin, conventional compounding techniques and mixing techniques such as a pump blender, Banbury mixer, super mixer, etc. are used. This can be done by mixing with another blender or mixer and then forming into a film.

To form a synthetic resin into a film, methods known per se,
For example, a melt extrusion method, a solution casting method, a calender method, etc. may be employed.

If the thickness of the agricultural synthetic resin covering material according to the present invention is too thin, the strength will be insufficient, which is undesirable.On the other hand, if it is too thick, it will be difficult to form a film, and the subsequent handling (cutting the film and joining it into a house shape) In order to avoid inconveniences (including the work of expanding the structure into a greenhouse), it is preferable to set the distance within the range of 0.01 to 0.5 m.

As described above, the agricultural synthetic resin coating material according to the present invention includes:
Although the anti-fog properties and anti-fog durability of the inside coated with the coating material are improved, it is better to improve the dust-proof properties of the outside of the coating material as well. It is preferable to form a dustproof coating based on a water-soluble paint, an ultraviolet curable paint, or the like.

The agricultural synthetic resin covering material according to the present invention can be applied to agricultural and horticultural facilities such as greenhouses and tunnels in the same manner as conventional agricultural covering materials and used for cultivating useful plants. I can do that.

[Effects of the Invention] The agricultural synthetic resin covering material according to the present invention has the following particularly remarkable effects, and its industrial utility value is extremely large.

(1) As is clear from the examples described later, in a tunnel in which a greenhouse in which the agricultural synthetic resin covering material according to the present invention is spread is spread, fog generation near the inner surface of the covering material is effectively suppressed.

Its suppressive effect is extremely strong, and it can virtually completely suppress fog even in late autumn and winter, when it has traditionally been said that fog occurs frequently, and it has a remarkable effect on preventing the occurrence and spread of diseases on useful plants. be.

Therefore, unlike the conventional method, there is no need to pay close attention to irrigation, etc.

(2) Since the agricultural synthetic resin according to the present invention contains a specific fluorine-containing compound and a surfactant, it not only has an effect of suppressing fog generation, but also has excellent anti-fogging properties and long-lasting anti-fogging properties. , useful for the facility cultivation of useful plants.

“Examples” The present invention will be explained in detail based on Examples below.
The present invention does not go beyond its gist.

It is not limited to the following examples.

Examples 1 to 6, Comparative Examples 1 to 9 Polyvinyl chloride (β-1300) 100 parts by weight Dioctyl phthalate 50 Ba-Zn liquid stabilizer 2 Ba-Zn powder stabilizer 1 Basic composition, An antifogging agent and a fluorine-containing compound shown in Table 1 were added to this in the proportions shown in Table 1. The mixture was supplied to a calender molding machine heated to 180° C. and formed into a film by a conventional method to produce 14 types of films (excluding Comparative Example 9) with a thickness of 0.075 mg.

The above 14 types of films have a commercially available thickness of 0.07
5. Anti-fogging properties A total of 15 types of polyvinyl chloride films for industrial use (Comparative Example 8) were evaluated for their anti-fogging properties and the amount of moisture condensed on the inner surface of the films according to the methods described below.

The results are shown in Table 1.

■ Evaluation of anti-fogging property A field in Nagoya City, Aichi Prefecture, with 1 width, 2 rows, and 2 sets of ridge height, depth 20
A true single-roof type house was coated with the above 15 types of films (August 2, 1980), and the antifogging properties of each film were observed with the naked eye.

The numerical values of "antifogging performance evaluation" shown in Table 1 have the following meanings.

rlJ... Water adheres in a thin film and no water droplets are observed.

"2": Water is attached in a thin film, but slightly large water droplets are observed.

"3": Water is attached in a thin film, but large water droplets are observed to be attached in some areas.

"4": A state in which small water droplets are observed to be attached in some areas.

"5": A state in which fine water droplets are observed on the entire inner surface of the film.

■ Amount of water condensation on the inner surface of the film A rain gutter was installed on the shoulder of the same type of greenhouse as the one used for the evaluation test in (1) above, extending in the direction of the depth of the house, and the amount of water flowing down the inner surface of the film was measured. The test is 1
The house was covered with five types of film on November 10, 1981, and the amount of moisture condensation was measured for 20 days from December 5 to December 24 of the same year, for 1 hour per 11 square meters of the inner surface of the film. It was calculated as the amount of water flowing down. The unit of this value is g/rn'@hr.

(Strawberry Cultivation Test) In a field in Shigun, Mie Prefecture, 30 days before ridge making, 3.0 kg of compost and 150 g of limestone were applied per square meter, and 15 days before ridge making, 15 g of fish meal and 5 g of urea were applied. , 40 g of dissolved phosphorus fertilizer and 5 g of potassium chloride were applied.

Two pipe houses with a width of 4.8 stories and a depth of 50 stories were constructed in this field, and on October 24, 1981, half (A section) of the pipe house in the length direction was constructed as shown in Example 4. The remaining half (section B) was covered with the film of Example 5, respectively. The pipe house in the other building was similarly covered with the film of Example 6 (section 0) and the film of Comparative Example 8 (section D). The film of Example 4 and the film of Example 5 were hung from the ceiling at the boundary between Wards A and B to serve as a partition, and at the border between Wards 0 and D.

The film of Example 6 and the film of Comparative Example 8 were hung from the ceiling to serve as partitions.

In each pipe house, four ridges each having a height of 30 cm and a width of H cm were provided, and each ridge was covered with a black mulching film. On October 30, 1981, strawberry seedlings (variety name ``Harunoka'') were planted at 30 cm intervals. lO after planting
On day 0 and day 70, 15 g of fishmeal, 7.5 g of urea, and 10 g of potassium chloride were applied as additional fertilizer per square meter.

After planting, while cultivating strawberries according to the conventional method,
The following items were investigated in each ward between January 8th and January 28th. The results are shown in Table 2.

■ Amount of water condensed on the inner surface of the film A rain gutter was installed on the shoulder of the pipe house, extending in the direction of the depth of the house, to collect water flowing down the inner surface of the film, and measure the amount of water. The measurement was carried out for 20 days, and the inner surface of the film 1
Calculated as the average amount of water flowing per hour per square meter. The unit is g/rn'·hr.

■ Condition of water droplet adhesion on plant surface Water droplets adhering to the leaves, stems, and fruits of plants during cultivation were observed and evaluated with the naked eye. The numerical values in the column "Plant surface water droplet adhesion status" in Table 2 have the following meanings.

"1": No adhesion of water droplets was observed.

"2"...Slight adhesion of water droplets is observed.

"3"...Water droplets are clearly observed on the leaf tips.

"4": Water droplets are also observed on the fruit.

■ Disease occurrence situation: Plants were observed and evaluated with the naked eye during cultivation. The evaluation criteria were as follows. In addition, before the evaluation period mentioned above,
If any disease outbreak was observed, a 1000x solution of Topjin hydrating agent was sprayed on all plots.

"l": No disease outbreak is observed.

“2”: Slight occurrence of disease is observed.

■ Amount of moisture absorbed by paper placed on the ground A ring made of wire was placed 10 cm above the ground, a paper (5A, 11 cmφ) made by Toyo Roshi ■ was placed on top of it, and the amount of moisture absorbed by this filter paper was measured. The measurement was carried out by placing the filter paper on a ring at 3:00 pm, collecting it at 8:00 am the next day, and measuring the increase in weight of the filter paper, which was taken as the average value for 20 days.

■ Evaluation of fog occurrence The degree of fog occurrence was observed 12 times per day, hourly from 7 a.m. to 6 p.m., and the results are shown in Table 2 numerically as "fog occurrence evaluation." Ta.

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

"1": No fog is observed inside the house, or a slight amount of fog is generated only near the inner surface of the film.

"2"...There is fog throughout the house, but 25
The back of the toe house can be clearly identified.

"3"...The whole house has a slightly thick fog, 25
■The back of the previous house cannot be clearly identified.

"4": A thick fog has formed throughout the house, making it impossible to discern the depths of the house 25 floors ahead.

From Tables 1 and 2, the following becomes clear.

(1) The agricultural synthetic resin coating material according to the present invention exhibits little deterioration in antifogging properties even when exposed to high temperatures in summer.

(2) When the fluorine-containing compound is represented by the general formula (I) or (II), the coating material has excellent antifogging properties and antifogging durability. On the other hand, fluorine-containing compounds
General formula (I).

If it is not represented by (II), the antifogging durability of the film will not be excellent.

(3) Moisture present in the space of the house or tunnel formed by the agricultural synthetic resin coating material according to the present invention is promoted to condense on the inner surface of the coating. This can reduce the humidity in the space, reduce the adhesion of water droplets to the surface of the plants being cultivated, and reduce the occurrence of diseases.

Claims (3)

[Claims] (1) Agriculture characterized by containing a fluorine-containing compound represented by the following general formula (I) and/or (II) and an antifogging agent other than that represented by the general formula (I) or (II). Synthetic resin coating material for use. General formula: (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. Fluoroalkyl group, R is H, alkyl group with 1 to 10 carbon atoms, or ▲Mathematical formula, chemical formula, table, etc.▼(
R' is an alkyl group having 1 to 10 carbon atoms), and n and m are integers of 1 to 20. ] (2) Per 100 parts by weight of the synthetic resin, the fluorine-containing compound represented by the general formula (I) and/or (II) is added in the range of 0.01 to 2.0 parts by weight.
), (II) The agricultural synthetic resin coating material according to claim (1), wherein the agricultural synthetic resin coating material is blended in an amount of 1 to 5 parts by weight of an antifogging agent other than those represented by (II). (3) The antifogging agent other than those represented by general formulas (I) and (II) is one selected from nonionic surfactants. 2nd (2nd
) Agricultural synthetic resin covering material as described in item ).