JP2637736B2 - Agricultural synthetic resin coating - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an agricultural synthetic resin covering material. More specifically, there is an ability to suppress the fog generation phenomenon near the inner surface of the coating material (this ability is referred to as anti-fog property), and the ability to exhibit the anti-fog property for a long time (this ability is the (Referred to as fog persistence)).

[Conventional technology and its problems] In recent years, in order to enhance the productivity and marketability of useful plants, useful plants are cultivated, semi-promoted or suppressed under cultivation under agricultural covering materials such as vinyl films for agriculture. So-called house cultivation and tunnel cultivation are actively performed.

In this house cultivation and tunnel cultivation, most of the synthetic resin coating materials currently used, for example, vinyl chloride resin films, are the inner surfaces of the coating materials (the surfaces facing the inside of the house or tunnel. The same applies hereinafter. ) Contains an antifogging agent (mainly a sorbitan fatty acid ester; glycerin fatty acid ester, etc.), which is a type of surfactant, to promote the flow of water droplets and increase the amount of sunlight. Under the coating of such a coating material containing an antifogging agent, a temperature difference between the inside and outside of the coating material becomes large, so that a phenomenon that fog is generated near the inner surface of the coating material is often observed.

The fog generation phenomenon occurs frequently in late autumn or winter, which is the most important for facility cultivation such as house cultivation and tunnel cultivation. The cause of the fog phenomenon is not known exactly, but the temperature and humidity in the house or tunnel, the temperature of the soil in the house or tunnel, the water content, the amount of solar radiation in the house or tunnel, the degree of hydrophilicity of the wet surface of the coating material Delicately affect each other, moisture in the house or tunnel adheres smoothly to the surface of the coating material due to temperature change, and the phenomenon of flowing does not occur, and some moisture becomes mist near the inner surface of the coating material It is presumed to be due to

According to the observations made by the present inventors, it has been found that such a fog generation phenomenon occurs near the ground surface in a house or a tunnel, near a cultivated plant, and near a coating material inner surface. Furthermore,
The coating material and the inner surface of the coating material are cooled by a decrease in the outside air temperature, and a temperature difference is generated between the coating material and the inside of the house, and the warm and moist air in the house moves to the vicinity of the coating material inner surface by natural convection. It has been found that water vapor that can no longer be contained in the air condenses into minute water droplets, becomes mist, and spreads in the house or tunnel by natural convection.
When the mist-like fine water droplets once generated evaporate and disappear again in the middle of natural convection, the mist does not spread in the house or tunnel, but if the evaporation and elimination speed is slow, the entire house or tunnel will It turned out to be a thick fog.

Such a fog phenomenon wets leaves, stems, flowers, fruits, and the like of useful crops cultivated in a house or a tunnel, and causes disease outbreak or helps in disease outbreak propagation. In addition, when the cultivated crop gets wet, heat required to dry it is required, and disadvantages such as the need for more fuel for heating the inside of the house or tunnel occur. Further, since the prospect in the house is deteriorated, there is an adverse effect such as a decrease in efficiency of the agricultural work.

Conventionally, in order to eliminate such disadvantages, colored agricultural synthetic resin films have been used, or soil in the houses or tunnels has been covered with mulching films in order to soften the temperature change in the houses or tunnels. Measures such as controlling the amount of water evaporation, further devising the time of watering (for example, watering late in the evening, adjusting the watering part and watering amount, etc.) and improving the watering method and equipment. Has been taken. However, none of these methods was effective in completely suppressing the fog phenomenon.

As a technique for improving such disadvantages, a method of blending a fluorine-based surfactant with a coating material (Japanese Patent Laid-Open No. Sho 57-14648) or a method of blending a fluorine-based oligomer with a coating material filed by the present applicant has been proposed. Method (JP-A-59-80468)
Has been proposed. According to the experiment of the inventor, according to
In the normal fluorinated surfactants described in -14678, not all fluorinated surfactants exhibit anti-fog properties, and even compounds that exhibit anti-fog properties have sufficient anti-fog properties. And it was found that its anti-fog susceptibility was insufficient.

[Means for Solving the Problems] In such a situation, the present inventors have the ability to suppress the fog generation phenomenon near the inner surface of the coating material (fog resistance).
In addition, as a result of intensive studies with the aim of providing a synthetic resin coating material for agricultural use having excellent anti-fog susceptibility, the structure is completely different from the previously proposed fluorine-based surfactants and fluorine-based oligomers. The present inventors have found that a special fluorine-containing compound is extremely effective, and have completed the present invention.

 That is, the present invention is the following invention.

When it is a reaction product of the following (A) and the following (B) and the reaction product has a free functional group, the functional group may be modified. Wherein a fluorine-containing compound (C) having a polyfluoroalkyl group (excluding the compound represented by the following formula [I]) and an anti-fogging agent other than the fluorine-containing compound (C) are compounded in the synthetic resin. A synthetic resin covering material for agriculture characterized by the following.

(A): the majority or all of the oxyalkylene groups are oxyethylene groups, and the oxyethylene groups are 2 to 2
A polyoxyalkylene polyol in which the terminal of a polyoxyalkylene chain containing 30 is a hydroxyl group, or a polyoxyalkylene polyamine in which the hydroxyl group terminal of the polyoxyalkylene polyol is substituted with an amino group.

(B): a reactive polyfluoro compound having one group selected from the group consisting of a hydroxyl group, an epoxy group, a carboxyl group, an isocyanate group, a halogen, and a carboxyl group derivative functional group, and a polyfluoroalkyl group.

(However, in the formula [I], R _f ′ represents a perfluoroalkyl group having 6 to 10 carbon atoms, and a represents an integer of 5 to 30.) The fluorine-containing compound (C) in the present invention is oxyethylene. It is a compound having a polyoxyalkylene chain whose main component is a polyoxyalkylene chain and two or more polyfluoroalkyl groups (hereinafter abbreviated as R _f groups), which is easy to produce, has high anti-fog properties and high durability, Compounds having an _Rf group at the terminal of the polyoxyalkylene are preferred. However, the case where the fluorine-containing compound (C) in the present invention is a compound represented by the following formula [I] is excluded.

(However, in formula [I], R _f ′ represents a perfluoroalkyl group having 6 to 10 carbon atoms, and a represents an integer of 5 to 30).

Two oxyethylene groups are contained in the polyoxyalkylene chain.
0 to 30, preferably 5 to 15, other oxyalkylene groups such as oxypropylene group, oxybutylene group, oxyphenylene group 0 to 10, preferably 0 to 0
It contains five. It is preferable in terms of performance that the number of oxyethylene groups be larger than the number of other oxyethylene groups, and a polyoxyalkylene chain having only oxyethylene groups is particularly preferable. When it contains both an oxyethylene group and another oxyalkylene group, these may be bonded in a block shape or in a random shape.

The fluorinated compound (C) is a compound obtained by reacting a polyfunctional polyoxyalkylene polyol or polyoxyalkylene polyamine having a polyoxyalkylene chain with a functional compound having an _Rf group. Especially 2
A polyoxyalkylene polyol or polyoxyalkylene polyamine having a functionality of the polyoxyalkylene chain, reaction products with two _the R _f group obtained by reacting a functional compound 2 molecule having one functional _the R _f group Are preferred.

As the polyfunctional compound having a polyoxyalkylene chain, a polyoxyalkylene polyol or a polyoxyalkylene polyamine (A) is used. In particular, a polyoxyalkylene diol having two hydroxyl groups and a polyoxyalkylene chain is preferable.

On the other hand, as the functional compound having an _Rf group to be reacted with (A), the _Rf- containing polyfluoro compound (B) having a functional group capable of reacting with a hydroxyl group or an amino group is used.
Is used. Examples of the reactive functional group that reacts with the hydroxyl group or the amino group include a hydroxyl group, an epoxy group, a carboxyl group, an isocyanate group, and a halogen.
Further, a highly reactive carboxyl derivative functional group such as carbonyl chloride may be used. Particularly preferred functional groups are an epoxy group, a carboxyl group, and a carboxyl group derivative functional group, and an epoxy group is particularly preferred. As the epoxy group-containing compound, a reaction product of an _Rf- containing alcohol and epichlorohydrin is preferable.

When the reaction product (C) obtained by reacting (A) and (B) has a functional group such as a free hydroxyl group or a carboxyl group, the reaction product is further modified if necessary. be able to. For example, a hydroxyl group can be converted to an acyloxy group, and a carboxyl group can be converted to an amide group.

Preferred specific examples of the fluorine-containing compound (C) in the present invention are shown below, but the present invention is not limited to these. The particularly preferred fluorine-containing compound (C) is a reaction product of a polyoxyalkylenediol and an epoxy group-containing _Rf compound as shown in the following formula (1).

(3) C ₈ F ₁₇ CONHC ₂ H ₄ OC ₂ H ₄ O ₆ C ₂ H ₄ NHCOC ₈ F ₁₇ (6) C ₁₀ F ₂₁ COOC ₂ H ₄ O ₈ COC ₁₀ F ₂₁ (7) C ₈ F ₁₇ C ₂ H ₄ OC ₂ H ₄ O ₁₀ C ₂ H ₄ C ₈ F ₁₇ (In the examples described later, Represents the fluorine-containing compound only by the corresponding number.) As R _f in the fluorine-containing compound (C), a polyfluoroalkyl group having the following structure is preferable, and a first to second perfluoroalkyl group is particularly preferable. .

CF ₃ CF _{2 l} l is an integer of ₂ to 19 The HCF ₂ CF _{2 n n} R _f is the integer invention 2 to 19, other of the polyfluoroalkyl group, a branch which is synthesized with oligo Mary internalization of _{CF 2 = CF 2, CF 3} CF = CF 2 And C ₃ F ₇ O ₃ F ₆ O _k CO [k is an integer of 0 to 5].

The synthetic resin material constituting the agricultural synthetic resin coating material of the present invention generally includes a film-forming thermoplastic synthetic resin. Specifically, vinyl chloride, ethylene, propylene, acrylic acid ester, methacrylic acid ester and the like monomers alone or copolymers thereof, or at least one of these monomers and other copolymerizable Copolymers with monomers (eg, vinyl acetate, vinylidene chloride, etc.), fluorine-containing resins, polyesters, polyamides, etc., and blends of these polymers can be mentioned. Among these, from the viewpoints of weather resistance, light transmittance, economy, and strength, vinyl chloride resins (ie, polyvinyl chloride and its copolymer containing 50% by weight of vinyl chloride) and ethylene resins (ie, , Polyethylene and its copolymers containing at least 50% by weight of ethylene), most preferably polyvinyl chloride.

The fluorine-containing compound (C) in the present invention can be used alone or in combination of two or more. This fluorine-containing compound (C)
Can be widely varied according to the type of the fluorine-containing compound (C) to be mixed, the type of the base synthetic resin, and the like. Generally, the base synthetic resin 100
The amount can be at least 0.01 part by weight per part by weight (however, the plasticizer is not included in the calculation; the same applies hereinafter);
The upper limit of the amount is not strictly limited, but if the amount is too large, bleed-out or cloudiness may occur. Therefore, usually 2.0 parts by weight or less is sufficient. The preferred range of the amount is 0.02 to 1.0 parts by weight per 100 parts by weight of the base synthetic resin.

In order to provide the antifogging agent 4 to the agricultural covering material of the present invention,
An antifogging agent conventionally used in the field of vinyl chloride resin films for agriculture is blended. The antifogging agent that can be used in the present invention means the antifogging agent excluding the fluorine-containing compound (C) in the present invention.

Specific examples of antifogging agents that can be used include, for example, sorbitol, mannitol, glycerin, polyglycerin,
Pentaerythritol, polyhydric alcohols such as trimethylolpropane, and a nonionic interfacial lubricant derived from a fatty acid having 10 to 22 carbon atoms, or a non-ionic surfactant derived from the polyhydric alcohol, a fatty acid, and an alkylene oxide Ionic interfacial lubricating preparations. The fatty acid having 10 to 22 carbon atoms may be any of linear or branched fatty acids.

More specifically, in addition to fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, instearic acid, behenic acid, oleic acid, beef tallow, rapeseed oil, corn oil, soybean oil, cottonseed oil, palm oil, sesame oil, Linseed oil, fatty acids obtained from these hardened oils, and
These mixed fatty acids can be mentioned.

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

The antifogging agent also exhibits an antifogging property even in the low temperature season in winter, is hardly extracted from the coating material even in the high temperature season in summer, and is preferably selected from those which maintain the antifogging property for a long period of time. Polyhydric alcohols having sorbitol, mantonitol, and a degree of condensation of 2
Polyglycerol is a fatty acid whose carbon number is 16 ~
Nonionic surfactants derived from 18 fatty acids, or nonionic surfactants derived from the above-mentioned polyhydric alcohols, fatty acids, and ethylene oxide or propylene oxide. Also, among the nonionic surfactants, the number of water molecules released by the intramolecular dehydration condensation reaction of the polyhydric alcohol during the esterification reaction between the polyhydric alcohol and the fatty acid is such that the number of water molecules per polyhydric alcohol molecule is 2 or less. Is better. Further, the content of the diester in the ester mixture obtained by the reaction between the polyhydric alcohol and the fatty acid is preferably 20 to 80% by weight based on the total weight. In addition, the total amount of ethylene oxide and / or propylene oxide added is 5 per mole of polyhydric alcohol.
Non-ionic surfactants that are less than or equal to moles are most preferred.

The amount of the antifogging agent in the base resin can be the same as that used for a conventional agricultural synthetic resin film. Generally, it can be in the range of 1 to 5 parts by weight, preferably 1.5 to 3.5 parts by weight, per 100 parts by weight of the synthetic resin substrate.

The synthetic resin base material constituting the agricultural coating material according to the present invention or, if necessary, usual various resin additives such as a plasticizer, a lubricant, a heat stabilizer, an antistatic agent, an ultraviolet absorber, a pigment, and a dye. And the like can be contained in a usual amount.

For example, regarding the preferred soft vinyl chloride resin in the present invention, polyvinyl chloride having a degree of polymerization of about 1,000 to 2,000
The plasticizer can be blended in about 30 to 70 parts by weight based on 100 parts by weight. 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; diisooctyl isophthalate and the like. Adipic acid derivatives such as di-n-butyl adipate and dioctyl adipate;
maleic acid derivatives such as n-butylmalate; tri-n-
Citric acid derivatives such as butyl citrate; itaconic acid derivatives such as monobutyl itaconate; oleic acid derivatives such as butyl oleate; ricinoleic acid derivatives such as glycerin monoricinoleate; other tricresyl phosphate, trixyl phosphate, epoxidized Examples include soybean oil and epoxy resin plasticizers.

Examples of the lubricant or heat stabilizer that can be contained in the synthetic resin base include polyethylene wax, bisamide, stearic acid, zinc stearate, barium stearate, calcium stearate, and barium ricinoleate. Examples of the ultraviolet absorber include benzotriazole-based, benzoate-based, benzophenone-based, cyanoacrylate-based, and phenyl salicylate-based ultraviolet absorbers. Examples of pigments and dyes include titanium oxide, silica, ultramarine, phthalocyanine blue, and the like.

These resin additives can be contained in a usual content, for example, a small amount of 5 parts by weight or less per 100 parts by weight of the synthetic resin base material.

In order to include the above-mentioned fluorine-containing compound (C), antifogging agent and, if necessary, various resin additives in the synthetic resin serving as the base material, a usual blending technique and a mixing technique such as a ribbon blender, a Banbury mixer, After mixing with a super mixer, another compounding line, or a mixer, it is possible to form a film.

In order to form the synthetic resin into a film, a method known per se, for example, a melt extrusion method, a solution casting method, a calendering method or the like may be employed.

When the thickness of the agricultural synthetic resin coating material according to the present invention is too small, the strength is insufficient and the strength is not preferable. Conversely, when the thickness is too large, the film is formed into a film, and the subsequent handling (the film is cut and joined into a house mold). , Etc.), which is inconvenient to perform, for example, the work of spreading to a house).

The agricultural synthetic resin coating material according to the present invention has, as described above, an anti-fogging property on the inner side covered with the coating material and an improved fog resistance, but also has an improved dustproof property on the outer side of the coating material. Good to put. In order to improve dust resistance, it is preferable to form a dust-proof coating based on a solvent paint, a water-soluble paint, an ultraviolet curable paint, or the like.

The agricultural synthetic resin coating material according to the present invention can be spread on agricultural and horticultural facilities such as a house and a tunnel and used for cultivation of useful plants, in the same manner as a conventionally used agricultural coating material.

[Examples] Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to the following examples as long as the gist is not exceeded.

Examples 1-5, Comparative Examples 1-6 Polyvinyl chloride (= 1300) 100 parts by weight Dioctyl phthalate 50 parts by weight Ba-Zn liquid stabilizer 2 {Ba-Zn powder stabilizer 1} as a base composition The antifogging agent and the fluorinated compound (C) shown in Table 1 or the fluorinated compound for comparison were blended in the proportions shown in Table 1. The mixture was supplied to a calender molding machine heated to 180 ° C., and formed into films by a conventional method, thereby producing 11 kinds of films having a thickness of 0.075 mm.

The above 11 kinds of films were evaluated for fog resistance according to the method described below. The results are shown in Table 1.

Evaluation of fog resistance The degree of fog generation was 1 hour from 7:00 am to 6:00 pm
Observation was performed 12 times per day every hour, and the results are shown in Table 1 as numerical values as “evaluation of anti-fog properties”.

The numerical values of “Evaluation of fog resistance” have the following significances.

"1": No fog is seen in the house or only a little is found near the film inner surface.

“2”: Fog is generated in the entire house, but the depth of the house 25 m away can be clearly identified.

"3" 霧 The fog is slightly dense throughout the house, and the interior of the house 25 m away cannot be clearly identified.

"4" 霧 The fog is generated densely in the whole house, and the inside of the house 25m away cannot be recognized at all.

[Effect of the Invention] The agricultural synthetic resin coating material according to the present invention has a particularly remarkable effect as described below, and its industrial utility value is extremely large.

(1) In a house or a tunnel in which the agricultural synthetic resin coating material according to the present invention is spread, the generation of fog near the inner surface of the coating material is effectively suppressed as is clear from the above-described embodiment. Its suppression effect is extremely powerful, and it can substantially completely suppress fog generation even in the late autumn or winter, when it has been said that fog frequently occurs, and has a remarkable effect on the prevention of disease generation and transmission of useful plants. is there.

Therefore, it is not necessary to pay close attention to irrigation and the like as in the related art.

(2) Since the agricultural synthetic resin according to the present invention contains a specific fluorine-containing compound and a surfactant, it is excellent in not only the effect of suppressing fog generation but also the anti-fogging property and the anti-fog property. It is useful for institutional cultivation of useful plants.

Claims (2)

(57) [Claims] 1. A reaction product of the following (A) and the following (B), and when the reaction product has a free functional group, the functional group is modified. Good, 2
The fluorinated compound (C) having the above polyfluoroalkyl group (except for the compound represented by the following formula [I]) and the antifogging agent except for the fluorinated compound (C) were blended in the synthetic resin. A synthetic resin covering material for agriculture characterized by the above. (A): the majority or all of the oxyalkylene groups are oxyethylene groups, and the oxyethylene groups are 2 to 2
A polyoxyalkylene polyol in which the terminal of a polyoxyalkylene chain containing 30 is a hydroxyl group, or a polyoxyalkylene polyamine in which the hydroxyl group terminal of the polyoxyalkylene polyol is substituted with an amino group. (B): a reactive polyfluoro compound having one group selected from the group consisting of a hydroxyl group, an epoxy group, a carboxyl group, an isocyanate group, a halogen, and a carboxyl group derivative functional group, and a polyfluoroalkyl group. (However, in the formula [I], R _f ′ represents a perfluoroalkyl group having 6 to 10 carbon atoms, and a represents an integer of 5 to 30.) 2. A polyoxyalkylene diol having a polyoxyalkylene chain containing two hydrogen groups and 2 to 30 oxyethylene groups, wherein the fluorinated compound (C) is:
The agricultural synthetic resin coating material according to claim 1, which is a reaction product of a reactive polyfluoro compound having an epoxy group and a polyfluoroalkyl group.