JPS62158756A - Synthetic resin covering material for agricultural use - Google Patents

Abstract

PURPOSE:To obtain the titled covering material which does not form brown spots and has excellent durable anti-fogging properties, by blending a co- oligomer of an unsaturated ester having a siloxane group with an unsaturated ester having a polyfluoroalkyl group. CONSTITUTION:A synthetic resin covering material is obtd. by blending a co- oligomer of an unsaturated ester having a siloxane group with an unsaturated ester having a 4-20C polyfluoroalkyl group. As the synthetic resin, polyvinyl chloride is most advantageous from the viewpoints of weather resistance, light transmissibility, economy and strength. As the unsaturated ester having a siloxane group, an acrylate or methacrylate having a siloxane group at its terminal is preferred. As the unsaturated ester having a polyfluoroalkyl group, an acrylate or methacrylate is preferred. As the polyfluoroalkyl group, one having a perfluoroalkyl group at its terminal is preferred.

Description

[Detailed description of the invention] [5f for industrial use] The present invention relates to synthetic resin covering materials for agriculture.

More specifically, it has the ability to suppress fog generation near the inner surface of the coating material (this ability is called anti-fog property), and the ability to exhibit excellent anti-fog effects over a long period of time (this ability is called anti-fog property). This article relates to synthetic resin coating materials for agricultural use that have anti-fogging properties.

[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 actively 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. The causes of the 'R generation phenomenon are not precisely known, but include the temperature and humidity inside the house or tunnel, the temperature and moisture content of the soil inside the house or tunnel, the amount of solar radiation to the house or tunnel, and the hydrophilicity of the wet surface of the covering material. The humidity inside the house or tunnel smoothly adheres to the surface of the covering material due to temperature changes due to the subtle influence of the degree of humidity.

It is presumed that this is due to the fact that no flow phenomenon occurs and some moisture forms in the form of letters 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 once-generated shrinking water droplets 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 be covered. It was also found that there was 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 technology that improved these drawbacks,
As described in Publication No. 5573.

A method of using a surfactant as an anti-fogging agent in combination with a fluorine-based surfactant to improve fog-proofing properties, or
As described in Japanese Patent Application No. 5572, a method has been proposed in which a surfactant as an antifogging agent and an organic siloxane surfactant for improving antifogging properties are used together.

[Problems to be Solved by the Invention] According to studies by the present inventors, synthetic resin coating materials containing fluorine-based surfactants as described above cause brown spots on the surface when used for a long period of time. It became clear that there was a problem with weather resistance. On the other hand, it has been found that the synthetic resin coating material containing the silicone surfactant has a drawback in its anti-fog durability.

[F step 1 for solving the problems The present inventors have intensively investigated compounding agents that solve the above problems and have excellent fog prevention properties, and found that silicone surfactants and fluorine surfactants Surprisingly, by creating a copolymerized oligomer of an unsaturated ester containing a siloxane and an unsaturated ester containing a polyfluoroalkyl group, no brown spots were observed. The present invention was completed based on the discovery that it also has excellent anti-fog durability.

Therefore, the gist of the present invention is to provide an agricultural method characterized by blending a copolymerized oligomer of an unsaturated ester containing siloxane and an unsaturated ester containing a polyfluoroalkyl group having 4 to 20 carbon atoms. Exists in synthetic resin materials for use.

The synthetic resin material constituting the agricultural synthetic resin coating material of the present invention generally includes film-forming thermoplastic synthetic resins. The A-isomer is vinyl chloride, ethylene, propylene, acrylic ester, methacrylic ester, etc. alone or a copolymer of these, or at least one of these Qiff-isomers and other copolymerizable monomers. Examples include copolymers with polymers (eg, vinyl acetate, vinylidene chloride, etc.), fluorine-containing resins, polyesters, polyamides, etc., and blends of these polymers. Among these, from the viewpoint of weather resistance, light transmittance, economic efficiency, and strength, vinyl chloride resins (i.e., polyvinyl chloride and its copolymer containing 50 superimposed parts of vinyl chloride) and ethylene resins ( That is, 50% polyethylene and ethylene
Polyvinyl chloride is preferred, most preferably polyvinyl chloride.

Unsaturated ester containing siloxane in the present invention (
(hereinafter referred to as compound A).

Examples include n = integer of 1 to 100 n = integer of 1 to 100 n = integer of 1 to 100 n = integer of 1 to 100 n = integer of 1 to 100, etc. In particular, acrylate or methacrylate containing terminal siloxane Preferably, these compounds can be combined with one or two kinds of ingredients to form a copolymerization component.

The unsaturated ester containing a polyfluoroalkyl group having 4 to 20 carbon atoms (hereinafter referred to as compound B) is not particularly limited, but for example, the following acrylates or methacrylates are preferable.

CF3 (CF2)a CH20000(C1h)
=CH2GF3 (CF2)6 (CH2)20C
OC(CH3)-CH2CF3CCF2 )+ (:H
2CHz0COCI=CH2CF3 (CF2)+5
02N(C3H1)(CTo hOGOcH-C1hC
F3 CCh ) r (CH7)40COCR=CH
2CF3 (CF2 )I SO2N (CH3) (
CH2)20COC:H(CH3)COCH2CF3 (
CFz)7 SO? N(02H5)(Ill:H2)
20COCR-CH2CF3 (CF2)rGONH(
CH2)20COCR-C)12CF3(CF2)sG
ONH(CH2)zOcOc(CTo)=CH2CF3
CCF2)8CCH2)20GOCI-CHzGF3
(CF2)8 (CH2)20COC(CH3)-C
HzICCF? )+oCH20COCH-CH2(:F
2CI(Oh)+ocHtQCOC(CHz)=CH2
GF3 (CF2) + GH2G)1(0)1)CH
20GOC(CH3)=CH? The polyfluoroalkyl group includes one each of the present invention.

Because of their high seed effect, compounds having a barfluoroalkyl group at the terminal are particularly preferred.One or two of these compounds can be combined to form a copolymerization component.

In addition to the above-mentioned copolymerization components, the fluorine-based copolymerization oligomer of the present invention may further contain one or more of the following compounds as copolymerization components. For example, ethylene,
Vinyl acetate, vinyl chloride, vinyl fluoride, vinylidene halide, styrene, α-methylstyrene, p-methylstyrene, acrylic acid and its alkyl esters, methacrylic acid and its alkyl esters, poly(oxyalkylene) acrylate, poly(oxyalkylene) acrylate (alkylene) methacrylate, acrylamide, methacrylamide, diacetone acrylamide or methacrylamide, methylolated diacetone acrylamide or methacrylamide, N-methylolacrylamide or methacrylamide, vinyl alkyl ether, halogenated alkyl vinyl ether, vinyl alkyl ketone, butadiene, isoprene ,
Chloroprene, glycidyl acrylate or methacrylate, benzyl acrylate or methacrylate, cyclohexyl acrylate or methacrylate, 2-ethylhexyl methacrylate or acrylate, maleic anhydride, aziridinyl acrylate-1 or methacrylate, N-vinylcarbazole, and the like. Among these copolymerized components, polyoxyalkylene methacrylate is preferred because it does not inhibit antifogging properties.

The fluorine-containing copolymer oligomer of the present invention not only provides good anti-fog properties for various agricultural synthetic resin coating materials, but also provides excellent anti-fog durability and weather resistance at the same time. In order to express these functions in a well-balanced manner, the copolymerization ratio of Compound A should be at least 1% by weight, preferably 1 to 50% by weight, and the proportion of Compound B should be at least 10% by weight, preferably 30 to 50% by weight. A suitable content is 70% by weight. Copolymerization components other than Compounds A and B can be impregnated in an amount of θ to 69% depending on the purpose.

In addition, in order to obtain the fluorine-based oligomer of the present invention, the raw material polymerizable compound is dissolved in a suitable organic solvent, and a polymerization initiation source (such as a peroxide, an azo compound, or ionizing radiation that is soluble in the organic solvent used) is added. ), a solution polymerization method can usually be adopted. Suitable solvents for solution polymerization include toluene, ethyl acetate, isopropyl alcohol, 1,1,2-trichloro-1,2,2-)lifluoroethane, tetrachlorodifluoroethane, methylchloroform, and the like. The molecular sparrow of such oligomers is
If it is too large, the initial fog prevention effect will not be good, and
If it is too small, the sustainability of the fog prevention effect will be reduced, so the oligomer molecule should be selected from a range with an average molecular weight of about 1,000 to 1,000, preferably about 1,000 to 8,000. -HSO3)14 for adjustment
0H,)lscH2C0OH.

H9C8H17, MS (+2H25, H9C18H3/
, HSC2HaCsF1r.

A chain transfer agent of H9C2HaCOOC2H4CsF+ r g may be used. The oligomer modified into random,
A form such as a block or a graft may be adopted as appropriate.

The amount of the fluorine-based oligomer to be blended into the synthetic resin coating material can be varied over a wide range depending on the type of fluorine-based oligomer to be blended, the type of the base synthetic resin, etc. In general,
100% synthetic resin base! ,,j,, part (however, 5(
Plastics are not included in the calculation; the same applies hereafter. ) can be at least 0.01 part by weight, and the E limit of the amount to be blended is not strictly limited, but if too much is blended, there is a risk of bleed-out or cloudiness. Usually, 2.0 parts by weight or less is sufficient.

The preferred range of blending amount is 0.000 parts per 100 parts by weight of the synthetic resin material.
02 to 1.0 parts by weight.

In order to impart antifogging properties to the agricultural coating material of the present invention, these synthetic resin base materials are blended with an antifogging agent that has been conventionally used in the field of agricultural vinyl chloride resin films.

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 L polyhydric alcohols, fatty acids, and fullkylene oxide. Carbon number 10-22
The single-chain fatty acid may be either a straight-chain or branched-chain fatty acid.

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 blood, 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 in the low temperature period of winter, and is difficult to extract from the coating material even during the high temperature period of summer.
It is best to choose from among those that maintain anti-fogging properties for a long time.Polyhydric alcohols such as sorbitol, mannitol, and those with a degree of condensation of 2 to 10 are recommended as those that exhibit long-lasting anti-fogging properties.
It is a polyglycerin with a fatty acid having 16 to 1 carbon atoms.
B includes nonionic surfactants derived from fatty acids, or nonionic surfactants derived from the above-mentioned 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 or less per molecule of polyhydric alcohol. 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 propylene Most preferred are nonionic surfactants in which the total amount of added oxides is 5 moles or less per mole of polyhydric alcohol.

The blending amount of the base resin of the heat protection material can be the same as that used for conventional agricultural synthetic resin films. Generally, per 100 parts by weight of the synthetic resin base material,
It may range from 1 to 5 parts by weight, preferably from 1.5 to 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, etc. can be included in ordinary ox.

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 heptalic acid such as diisodecyl phthalate, didodecyl phthalate, diisodecyl phthalate, etc. Isophthalic acid 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 Oleic acid derivatives such as: ricinoleic acid derivatives such as glycerin monocitrate; other examples include tricresyl phosphate, trixyl phosphate, epoxidized soybean oil, and epoxy resin plasticizers.

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, penzophenone-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 1 or less, for example, 5 parts by weight or less per 100 parts by weight of the synthetic resin base material.

In addition to the synthetic resin that serves as the base material, fluorine-based oligomers, antifogging agents,
Furthermore, in order to incorporate various resin additives, if necessary, the mixture should be mixed using ordinary compounding techniques, mixing techniques, such as an Ebori pump blender, a Banbury mixer, a super mixer, or other compounding machine or mixer, and then formed into a film. This is possible.

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 make it into a film, and the subsequent handling (cutting the film and joining it into a house shape) (including the work of spreading it into a greenhouse), etc., so it is best to set it in the range of 0.01 to 0.51 intestine.

The agricultural synthetic resin coating material according to the present invention should also have improved dustproof properties on the outside of the coating material. In order to improve the dustproof properties, solvent paints, water-soluble paints, ultraviolet curable paints, etc. It is best to form a dustproof coating based on

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

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

Manufacturing example 1 In a Mitsuro flask with a reflux device CH2=CIC0OC? H4C5F++ 50g.

CH2・CCCH3)COO(C2HaO)-H: 3
5g: 00g of ethyl acetate was added. Furthermore, 2.6 g of HOC2Ha SH was added as a molecular weight regulator, 0.5 g of azobisisobutylnitrile was added as a polymerization initiator, and the reaction was carried out at 60° C. for 10 hours. After six reactions, the solvent was distilled off by drying under reduced pressure. (Copolymerized oligomer A) Production example 2 CH2=CH-C00C2HnC8F+ r 40g by the same method as production example 1
.

CH2lIC(CH3)C00(C2II4o←(C3
Hbo9-H: A reaction product was obtained using 55 g of monomer. (Copolymerized oligomer B) Production example 3 CH2-CH-C00C2HaN C8F++ 45
g.

■ 2 H5 CH2=C (C:H3)・COO117HaOH35g
A reaction product was obtained using the following monomers. (Copolymer oligomer〇) Examples 1 to 3, Comparative Examples 1 to 5 Polyvinyl chloride (P=1300) 100 weight!
l″E part Dioctyl phthalate 45 // Tricresyl phosphate 5 // Epoxy resin
2 //Ba-Zn liquid stabilizer
2 //Ba-Zn powder stabilizer
1 // Benzophenone ultraviolet absorber Q, l
//2/l of sorbitan monopalmitate (this composition is used), and the compounds shown in Table 1 are added to it as
It was blended with the formulation shown in the table - 1 cup.

(Evaluation of anti-fog durability and weather resistance) 1 width 2cm, ridge height 2m, depth 2cm in a field in Meizuya City, Aichi Prefecture
The above eight types of films were coated on a single-roof type house with a length of 0 m (100 m), and the antifogging properties and appearance of each film were observed with the naked eye. The results are shown in Table 2.

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

“1”: Water adheres in a thin film and no water droplets are observed.

"2"...Water is attached in a fiIIIQ shape,
Slightly large water droplets are observed.

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

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

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

The numerical values of "weather resistance evaluation" have the following meanings.

“1”: No change observed in appearance.

"2"...Slight brown spots are not observed.

"3"... Brown spots are observed here and there.

"4": Many brown spots are observed.

"5": Brown spots are observed on the entire surface.

(Strawberry Cultivation Test) In a field in Mie Prefecture, 30 days before ridge making, 3.0 kg of compost and 150 g of bitter lime were applied per 1 square meter, and 15 days before ridge making, 15 g of fish meal, 5 g of urea, and melting were applied. 40 g of phosphorous fertilizer and 5 g of potassium chloride were applied. 1 in this field
Nine pipe houses with a width of 4.8 m and a depth of 25 m were constructed, and Examples 1 to 3 and Comparative Example 1 were constructed on 26th lθ, 1981.
Nine films of ~6 were coated.

In each pipe house, four ridges each having a height of 30 cm and a width of 80 cm were provided, and six of the ridges were covered with black mulching film. On October 28, 1980, at 30cm intervals,
Strawberry seedlings (variety name: Haru no Kaori) were planted. On the 10th and 270th day after planting, 15 g of fishmeal, 7.5 g of urea, and 10 g of potassium chloride were applied as top dressing per square meter.

After planting, while cultivating strawberries according to conventional methods,
The following items were investigated in each ward between January 10th and January 29th. The results are shown in Table 3.

Amount of water condensed on the inner surface of the film A rain gutter was installed on the shoulder of the 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 surfaces Water droplets adhering to leaves, stems, and fruits of plants under cultivation were observed and evaluated with the naked eye. The values in the column ``Status of water droplet adhesion to plant surfaces'' in Table 3 are as follows.

Each has the following significance.

"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.

Plants were visually observed and evaluated during cultivation, and the evaluation criteria were as follows. In addition, before the above evaluation period,
If any disease outbreak was observed, Topgin hydrating agent tooo double solution was sprayed on all plots.

"l": No disease outbreak is observed.

“2”: Slight occurrence of disease is observed.

Evaluation of fog occurrence The degree of fog occurrence was observed 12 times a day every hour from 7:00 a.m. to 6:00 p.m., and the results are shown numerically in Table 3 as "fog occurrence evaluation". .

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
+S condition where the back of the house ahead 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": The entire house is covered in fog, and the back of the house cannot be discerned at all from 25 meters away.

[Effects of the Invention] The agricultural synthetic resin coating 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 above-mentioned examples, when a greenhouse in which the agricultural synthetic resin covering material according to the present invention is spread is used in a tunnel, the generation of fog near the inner surface of the covering material is effectively suppressed.

Its suppressive effect is extremely strong, and it can virtually completely suppress the occurrence of 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. There is.

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

(2) The agricultural synthetic resin according to the present invention contains a specific fluorine-containing oligomer.

Claims (1)

[Scope of Claims] 1. Unsaturated ester containing siloxane and having 4 to 4 carbon atoms
1. A synthetic resin coating material for agriculture, characterized in that it contains a copolymerized oligomer with an unsaturated ester containing 20 polyfluoroalkyl groups. 2. The agricultural synthetic resin coating material according to claim 1, wherein the unsaturated ester containing siloxane is an acrylate or methacrylate containing terminal siloxane. 3. The agricultural synthetic resin coating material according to claim 1, wherein the unsaturated ester containing a polyfluoroalkyl group is an acrylate or methacrylate containing a terminal perfluoroalkyl group.