JPH03215562A - Agricultural synthetic resin covering material - Google Patents

Abstract

PURPOSE:To obtain a covering material which can exhibit its antifogging properties for a long time without detriment to the persistence of antifogging properties by adding a specified fluorinated compound, magnesium hydroxide and a specified hydrotalcite to a synthetic resin. CONSTITUTION:100 pts.wt. synthetic resin is mixed with 1-5 pts.wt. antifogging agent, 0.01-0.5 pt.wt. fluorinated compound having at least two polyfluoroalkyl groups and at least one polyoxyalkylene group in the molecule, 0.5-10 pts.wt. magnesium hydroxide of a mean particle diameter of 3mum or smaller and 0.5-10 pts.wt. hydrotalcite of the formula: Mg1-xAlx(OH)2(CO3)x/2.mH2O (wherein 0<x<0.5; and 0<=m<=2) and a mean particle diameter of 3mum or smaller, and the obtained mixture is formed into a film or a sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to synthetic resin covering materials for agricultural use. More specifically, the ability to suppress the fog generation phenomenon near the inner surface of the coating material (this ability is referred to as fog resistance),
This invention relates to agricultural synthetic resin covering materials that have excellent long-term performance.

``Conventional technology'' In recent years, in order to increase the productivity and marketability of useful plants, they have been 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 used on the inner surface of the covering material (the surface facing the inside of the greenhouse or tunnel). It 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. Furthermore, under a covering material that prevents such antifogging agents, when the temperature difference between the inside and outside of the covering material becomes large, a phenomenon in which fog is generated near the inner surface of the covering material is often observed.

This fog generation phenomenon is no) us! It often occurs in late autumn or winter, which is the most important period for facility cultivation such as culturing and tunnel cultivation. The causes of the fog 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 adheres smoothly to the surface of the sheathing material due to temperature changes, and some of the moisture becomes mist near the inner surface of the sheathing material. It is presumed that this is due to the following.

According to the observations of the present inventors, the fog generation phenomenon as described in 2.
It has been found that it occurs near the ground surface inside tunnels, near cultivated plants, and near the inner surface of covering materials. Furthermore,
The sheathing material and the inside surface of the sheathing are cooled by the drop in outside temperature, creating a temperature difference between the outside and the inside of the case, and the warm, humid air inside the nozzle moves to the vicinity of the inside surface of the sheathing material by natural convection. It was discovered that the water vapor contained in the air that cannot be removed condenses into minute water droplets, which become mist and spread inside the house or tunnel through natural convection. If the mist-like minute water droplets 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,
It was also found that the entire house or tunnel was covered in thick fog.

Such fogging 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 required to dry them results in 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.

In order to eliminate this disadvantage, colored agricultural synthetic resin films or mulching films are used to cover the soil inside greenhouses or tunnels in order to soften the temperature changes inside greenhouses or tunnels. You can reduce the amount of water evaporation by covering it with water, and you can also improve the watering time (
For example, measures such as watering late in the evening, adjusting the area and amount of water to be watered, and improving irrigation methods and equipment may be taken. However, none of these methods was effective in completely suppressing the fog generation phenomenon.

As a technology that improved these drawbacks, Japanese Patent Application Laid-Open No. 57-1
As described in Japanese Patent Application No. 4648, a method has been proposed in which a surfactant M as an anti-yellowing agent and a 77-element surfactant to improve fog resistance are used in combination. Also, JP-A-59-
Japanese Patent Application No. 80468 also proposes a method of improving fog resistance by blending a copolymerized oligomer of an acrylate or teracrylate containing a terminal poly7-fluoroalkyl group with another copolymerizable compound.

[Problems to be Solved by the Invention] However, according to experiments conducted by the present inventors, when an antifogging agent is further combined with a fluorosurfactant or a copolymerized oligomer, agricultural synthetic resin coating materials Anti-fog properties, which are an essential feature of the It has been found that there are cases where the deterioration of antifogging properties is accelerated and the antifogging durability is significantly inferior. By reducing the amount of 77-element surfactant or copolymerized oligomer, anti-fogging properties may be adversely affected￥3
Although W can be reduced, the effect of suppressing fog generation is not satisfactory, and the fog-proofing property deteriorates particularly when used for a long period of time.

``Means for Solving the Problems'' Under such circumstances, the present inventors have developed a synthetic resin covering material for agricultural use that does not reduce the anti-fog durability and exhibits anti-fog properties over long periods of darkness. As a result of intensive studies with the aim of providing a special heptad-containing compound and magnesium hydroxide, the structure of which is completely different from the aforementioned heptad-based surfactants and copolymerized oligomers proposed by J. )
It has been discovered that fog-proofing properties can be exhibited for a long period of time by co-blending with hydrotarcinoid, and the present invention has been completed.

However, the gist of the present invention is that the synthetic resin 100
Per part by weight, 1 to 5 parts by weight of an antifogging agent and 0,01 to 5 parts by weight of a fluorine-containing compound containing two or more polyfluoroalkyl groups and one or more polyoxyalkylene groups in one molecule.
＼20.5 parts by weight and 0.5 parts by weight of magnesium hydroxide with an average particle size of 3 μm or less. 5-=, 10 parts by weight, average particle size 3
Hydrotalcites with a specific composition of 0.5-μm or less
=i0 parts by weight of the agricultural synthetic resin coating material, which is formed into a film or sheet.

The present invention will be explained in detail below.

The synthetic resin material constituting the agricultural synthetic resin covering material of the present invention generally includes film-forming thermoplastic synthetic resins. Specifically, monomers such as vinyl chloride, ethylene, brobylene, acrylic esters, and methacrylic esters may be used alone or in combination with each other, or at least one of these monomers may be copolymerized with other monomers. Examples include copolymers with polymers (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 or more of vinyl chloride) and ethylene resins ( Polyethylene and its copolymers containing 50% by weight or more of ethylene) are preferred, most preferably polyvinyl chloride.

These synthetic resin coating materials are blended with conventionally used antifogging agents in order to impart antifogging properties. Therefore, as the anti-yellowing agent that can be used in the present invention,
Mainly non-ionic surfactants [1, e.g. sorbitan mo7
Sorbitan surfactants such as stearate, sorbitan mo7 palmitate, and sorbitan monobehenate; Glycerin surfactants such as glycerin mo7 laurate, diglycerin mo/valmitate, and glycerin mo7 stearate M: polyethylene glycerin mo/stearate, polyethylene Polyethylene glyfur surfactants such as glycol mo-7 palmitate: 7-alkyl-7-enol
Examples include alkylene oxide adducts; esters of sorbitan/glycerin condensates and organic acids, and the like. These antifogging agents can be used alone or in combination of two or more. The amount of antifogging agent added to the base resin can be the same as that used for conventional agricultural composite I&resin films, and
For every 0 parts by weight, it can range from 1 to 5 parts by weight.

In the present invention, the 77-element compound is not limited in any way as long as it is a compound having a polyoxyalkylene chain containing an oxyethylene group as a main component and two or more polyfluoroalkyl groups (hereinafter abbreviated as Rf group). A compound having an Rf group at the end via a polyoxyalkylene group is preferred because it is easy to leave behind and has high antifog properties and durability.

There are 2 oxyethylene groups in the polyoxyalkylene chain.
・230 moles Preferably 3 ha.10 moles, and other oxyalkylene groups such as oxypropylene group, oxybutylene group, oxy7enylene group, etc.
mol, preferably 0 to 5 mol. It is preferable in terms of performance that the number of moles of the oxyethylene group be larger than the number of moles of other oxyalkylene groups, and a polyoxyalkylene group containing only oxyethylene groups is particularly preferable. Oxyethylene groups and other okynealkylene groups may be used in combination, or may be bonded in a rangum form.

As a method for producing a compound having an Rf group at the end via a polyoxyalkylene region, a method of reacting a compound having a polyoxyalkylene group with a compound having an Rf group is suitable.

Examples of compounds having a polyoxyalkylene region include polyoxyalkylene polyols, polyoxyalkylene polyamines, and reactive derivatives thereof. Examples of reactive derivatives include those obtained by converting a hydroxyl group or amine 7 group into a halide or alkali metal alkoxide, those into which an epoxy group is introduced by glycinole etherification, etc.
Examples include those that are esterified with polycarboxylic anhydride to introduce carboxyl groups, and those that are urethanized with polyisocyanate to introduce insinate groups (that is, incyanate group-terminated polyester prepolymer).

On the other hand, as a compound having an Rf group to be reacted with this, an Rf group-containing compound having a functional group capable of reacting with the above-mentioned hydroxyl group, amine 7 group, or other reactive functional group is used.

For example, Rf group-containing compounds having a hydroxyl group, an epoxy group, a carboxyl group, an insinate group, a halogen, etc. are used.

More specifically, for example, as a hydroxyl group-containing compound,
There are reaction products of R' group-containing carboxylic acids or Rf group-containing sulfonic acids and 7-l-alamines such as ethylamine. Examples of the Eboshi group-containing compound include a reaction product of an Rf group-containing alcohol and shrimp chlorohydrin.

As the Rf group in the present invention, a polyfluoroalkyl group having the following structure is desirable.

CF, (CMQ Q is an integer of 2\719}1c
F2(CF2) n is an integer of 2-, 19 In addition to the polyfluoroalkyl group, R in the present invention
In the f group, CF2=CF2, CF, CF=CF2 has a branch synthesized by oligomerization titane.
7-fluoroalkyl group, C. F, 0 (C 3
F 60 ), CO [k also includes an integer 1 from O to 5.

In addition, there are various methods other than those mentioned above, such as increasing the amount of a compound having an Rf group and a polyoxyalkylene chain, and introducing an Rf group into a compound having an R group and a polyoxyalkylene chain. can be obtained. Further, compounds having a polyoxy7-alkylene group and two or more Rf groups obtained by various methods can be further modified if necessary. For example, a hydroxyl group can be converted into an acyl group, or a carboxyl group can be converted into an amide group.

Preferred specific examples of the fluorine-containing compound in the present invention are shown below, but the present invention is not limited thereto.

C,F,CONHC2}1.0(C21{40)r. C2H.
NHCOC. F.C., F.C. , C.J. 0(C2H.0), CI. CHCII2C 2F2, 0H C, . F4 COO(C,H.0)l]OCC. ,F, C,F ,C,H. O(C.H.Cl). ,C. l{. C. F,, The heptadone-based compounds used in the present invention can be used alone, or in combination of two or more types.

The amount of this fluorine-based compound added to the synthetic resin coating material is:
It can be changed depending on the type of 77-element compound to be blended, the type of base synthetic resin, etc., and the base synthetic resin 100 weight f
! Is (but does not include plasticizers).

0.01 part by weight or more and 0.5 part by weight or less per (the same applies hereinafter) is sufficient. The preferred range of blending amount is synthetic resin 10
It is 0.02-0.2 parts by weight per 0 parts by weight.

In the present invention, magnesium hydroxide and hydrotalcites having an average particle size of 3 μm or less are further blended, and the amount of each is 0.5 to 1 per 100 parts by weight of the synthetic resin.
The range is 0 parts by weight. The blending ratio of magnesium hydroxide and hydrotalcites is 1:10-, 5:1.

By using a specific amount of these two components having specific average particle diameters in combination, the sustained effect of fog-proofing properties is greatly improved.

Hydrotalcites represented by the following compositional formula (1) are used.

Mg+1e ^1e (OH)2 (Co,). l2・
Shizu H20...(1) (However, O<,<O.S, 0
≦Theory≦2) Specifically, the following can be mentioned.

Mgo. r+y^+o. -3(on)2(coz). ．．
1-,・o. sH2oHF(o.t, ^lo.13(O
H)2(CO3)I,. 165"0.31'l20M
ga. 67＾1. ．． 33(OH)2(COx). ．． 16
sHgo. t^1o. 3 (OH), (C03). ．． I,
・0.5H20Hgo. 1^lo. 3(OH)2(CO
*). ．． 1,・0.3H20Ngo. , ^I. ．． ,(O
H)2(CO3). ．． , S The synthetic resin base material constituting the agricultural synthetic resin coating material according to the present invention may also contain various usual resin additives, such as plasticizers, lubricants, heat stabilizers, light stabilizers, Antioxidants, antistatic agents, ultraviolet absorbers, pigments, dyes, etc. can be included in conventional amounts.

For example, regarding the soft vinyl chloride resin suitable for the present invention, about 30 parts by weight of a plasticizer is added to 100 parts by weight of polyvinyl chloride having a degree of polymerization of about 1,000 to 72,000.
-,． It can be blended in a proportion of 70 parts by weight.

Suitable plasticizers that can be used include, for example, heptatalic acid derivatives such as di-101 octyl 7-talate, no-2-ethylhexyl 7-talate, nobennol 7-talate, noindecyl 7-talate, nododecyl 7-talate, and noundecyl 7-thale; diisooctyl; Iso-7-talic acid derivatives such as 7-talate; Anovic acid derivatives such as no-101-butylanobate and no-octyl anopate; Maleic acid derivatives such as no-roptyl maleate; Citric acid derivatives such as tri-11-butyl citrate; Itaconic acid derivatives such as butyl itaconate; Oleic acid derivatives such as butyl oleate; Lysyl acid derivatives such as glycerol/ricinoleate; Other examples include tricrenorphos 7ate, eboxidized large V oil, and epoxy resin plasticizers.

The UV #iM absorbers are those commonly used for agricultural synthetic resin coatings, such as penzotriazole,
Ultraviolet absorbers such as penzoate, benzo-7, cyanoacrylate, and 7-enyl salicylate can be cited. Among them, benzo-7-7-based ultraviolet absorbers and/
Or a penzotriazole type ultraviolet #I@ collector is particularly preferred.

As a light stabilizer, 4-7 Setkin-2,2,6
．． 6-tetramethylbiperinone, 4-cyclohex-7yloxy-2. 2,6. 6-tetramethylbiverinone, 4-penzoyloxy-2,2,6,6-tetophmethylbiveridine, bis(2,2,6.6-tetramethyl-4-biverinol)anopate, bis(2, 2,6.
6-tetramethyl-4-bibelinol) sebacate,}lis(2,2.6.6-tetramethyl-4=bibelinol)
Benzene-1. 3. 5-}ricarboxylate, tetrakis(2,2,6,6-tetramethyl-4-biveridyl)propane-1.1,2.3-tetracarboxylate, and other hindamine compounds.

Examples of antioxidants include 2,6-nort-butyl-4-methyl 7 ether, 2,2'-/tyrene bis(6-
Examples include tert-butyl-4-ethyl 7-l), nolaurylthionobionate, and the like.

Examples of the lubricant or heat stabilizer include polyethylene wax, liquid paraffin, stearic acid, zinc stearate, aliphatic alcohol, calcium stearate, barium stearate, barium ricylate, dibutyltin dilavrate, noptyltin nomalate, organic Examples include phosphate metal salts, organic phosphite compounds, 7-ethyl compounds, and β-nogatone compounds.

Examples of colorants include Lidmouth Cyanine Blue-7 Talocyanine Green, Hansa Yellow, Alizarin Lake,
Examples include titanium oxide, zinc white, ultramarine blue, permanent red, quinacridone, and carbon black.

These resin additives may be contained in a small amount of 10 parts by weight or less per 100 parts of heavy electricity in the synthetic resin base material6. To incorporate magnesium hydroxide, hydrotalcites, and various resin additives if necessary, use conventional compounding techniques and mixing techniques such as ribbon blenders, Banbury mixers, super mixers, and other compounding machines and mixers. Can be mixed by To form a synthetic resin into a film, methods known per se, such as melt extrusion method, solution flow method,
A calendar method or the like may be used.

If the thickness of the agricultural 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, the subsequent handling (cutting the film and joining it into a hat shape, etc.) It is recommended that the range be 0.03-\-0.2m, as this may cause inconvenience to workers (including the work of spreading the seedlings).

In the agricultural synthetic resin coated shrine according to the present invention, it is preferable to improve the dustproof property of the outer side of the coating material.

In order to improve dustproof properties, it is preferable to form a dustproof coating based on a solvent paint, 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 hatchets and tunnels in the same manner as conventional agricultural covering materials and used for cultivating useful plants. .

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.

To Example 1/3, To Comparative Example 1-4 Polyvinyl chloride (degree of polymerization = 1300) 100 parts by weight Dioctyl 7-talate 45 Tricrenorphos 7-ate 5 Eboxy resin
2 Ba-Zn liquid stabilizer 2 Ba-Zn powder stabilizer
1 〃Benzo7-7-based ultraviolet absorber
0.1 Sorbitan monobalmitate 2
〃 is the basic composition, and the fluorine-containing compounds, magnesium hydroxide, and hydrotalcites shown in table vJ1 are added to this,
The amounts shown in Table 1 were blended and mixed using a super mixer. The mixture was supplied to a calender molding machine heated to 180°C and formed into films by a conventional method to prepare seven types of films each having a thickness of 0.11.

A fog generation test and an antifogging property evaluation were conducted on the above seven types of films using the following methods.

The results are shown in Tables 2 and 3.

(1) F! Incidence test: Seven pipe houses with a width of 5.4 mm, a ridge height of 3 m, and a depth of ISm were constructed in a field in Shigun, Mie Prefecture, and each building was covered with one of the 7 types of ilms listed in H. The degree of fog generation was evaluated on the 5th day immediately after the pipe house was covered with a film (January 1988).
(October 31st and November 4th), 5 days (January 30th and February 3rd, 1989) four months after coating, and five days after six months after coating. Opening (April 3, 1989)
・It was held on April 7th).

[The numerical values of occurrence evaluation 1 of n have the following meanings.

[11... A state in which no fog is observed to be generated within the house, or a slight amount of fog is generated only near the inner surface of the film.

``21 --- There is fog throughout the house, but 15
Condition in which the back of the house m ahead can be clearly identified.

[31...A rather thick fog appeared throughout the house, and 15
It is not possible to clearly identify the back of the house at the end of the gloss.

``4] ...The entire house was covered in thick fog, and the back of the house 15-11 blocks away could not be discerned at all.

The second value is the average value of the five-day observation of fog occurrence.
Shown in the table.

(2) Evaluation of anti-fog properties A field in Nagoya City, Aichi Prefecture, with a width of 2 m, a ridge height of 2 so, and a depth of 3
The seven types of films mentioned above were installed in the single-roofed greenhouse of 0ron in 1932.
The film was coated on September 14, 1983, and another house of the same type was coated on October 30, 1988, and the anti-fog properties of each film were periodically checked with the naked eye. Dormitory and evaluation.

The results are shown in Table 3.

The numerical values of "anti-fogging evaluation" each have the following significance.

[11...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”: A state in which small water droplets are observed to be attached in some areas.

"4"...Fine water droplets all over the inner surface of the film Table 1 (Includes amounts in parts by weight) Table 2 Decay Table 3 "Effects of the invention" Agricultural synthetic tree *a coating according to the present invention The wood has the following special effects, and its industrial value is extremely large. (1) In greenhouses or tunnels in which the agricultural synthetic resin covering material according to the present invention is spread, the generation of fog near the inner surface of the covering material is effectively suppressed, and the fog-proof performance does not deteriorate even after long-term use. few. 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. effective. Therefore, there is no need to pay close attention to irrigation, etc., as in the past. (2) The agricultural synthetic resin covering material according to the present invention not only has an effect of suppressing fog generation, but also has excellent anti-fog properties and anti-rotation properties, and is useful for the facility cultivation of useful plants.

Claims (1)

[Claims] (1) Per 100 parts by weight of synthetic resin, 1 to 5 parts by weight of an antifogging agent and 0.01 part of a fluorine-containing compound containing two or more polyfluoroalkyl groups and one or more polyoxyalkylene group in one molecule. ~0.5 parts by weight, 0.5 to 10 parts by weight of magnesium hydroxide with an average particle size of 3 μm or less, and 0.5 parts of hydrotalcites represented by the following compositional formula (1) with an average particle size of 3 μm or less. 1. A synthetic resin covering material for agricultural use, characterized in that it contains ~10 parts by weight and is formed into a film or sheet. Mg_1_-_xAl_x(OH)_2(CO_3)_
x_/_2・mH_2O...(1) (However, 0<x<0.
5, 0≦m≦2)