JPH07298792A - Synthetic resin covering material for agriculture - Google Patents

Abstract

PURPOSE:To obtain the subject covering material improved in the persistence of anticlouding and antifogging properties, not bleeding out components for a long period, good in transparency, and suitable for the cultivation of plants in green houses or green tunnels. CONSTITUTION:The synthetic resin covering material for agriculture is produced by compounding 100 pts.wt. of a synthetic resin, 1-4 pts.wt. of an antifogging agent, 0.01-1.0 pt.wt. of one or both of a fluorinated surfactant and a silicone surfactant, and 1-20 pts.wt. of a lithium aluminum composite hydroxide salt of the formula, [Al2Li(OH)6]nX.mH2O is an inorganic or organic anion; n is the valency of the anion X; m is a number of <=3).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel synthetic resin coating material for agriculture, more specifically, it is suitable for use in greenhouses, tunnel cultivation, etc., and has improved antifogging and antifog durability.
The present invention relates to a synthetic resin coating material for agriculture, which does not bleed out for a long period of time and has good transparency.

[0002]

2. Description of the Related Art Agricultural synthetic resin coating materials contain various anti-fogging agents in order to prevent fogging on the inner surface when they are spread and used in a house or the like and to enhance the permeability of sunlight. . In addition to this, an antifog agent is added to prevent fog that occurs in the morning and evening. However, the effect of these compounding agents is only for about one season, and there is a strong demand for a coating material that can maintain the effect for a longer period of time. Attempts have also been made to add a large amount of these compounding agents, but this has the drawback that bleeding out during storage tends to impair transparency.

[0003]

DISCLOSURE OF THE INVENTION The present invention overcomes the drawbacks of the conventional covering materials for agricultural synthetic resins, improves the antifogging property and the fogproof property, and bleeds out over a long period of time. The purpose of the present invention is to provide a novel synthetic resin coating material for agriculture, which has no transparency and has good transparency.

[0004]

The inventors of the present invention have conducted various studies to develop a synthetic resin coating material for agriculture having the above-mentioned preferable characteristics, and as a result, the synthetic resin has a predetermined amount of antifogging agent. It has been found that the object can be achieved by blending a specific surfactant and a lithium aluminum complex hydroxide salt, and the present invention has been completed based on this finding.

That is, in the present invention, (A) 1 to 4 parts by weight, (B) a fluorine-based surfactant or a silicone-based surfactant, or both of them are added in an amount of 0.01 to 100 parts by weight of the synthetic resin. 1.0 part by weight and (C) the general formula [Al ₂ Li (OH) ₆ ] _n X.mH ₂ O (I) (wherein X is an inorganic or organic anion, n is the valence of the anion X, and m is The present invention provides a synthetic resin coating material for agriculture, which comprises 1 to 20 parts by weight of a lithium-aluminum composite hydroxide salt represented by the formula (3 or less).

The synthetic resin used as a base material in the coating material of the present invention is not particularly limited, and any one can be selected and used from those conventionally used for agricultural coating materials. Formable thermoplastics are preferred. Such a synthetic resin may be obtained by any commonly used production method such as a bulk polymerization method, an emulsion polymerization method, a suspension polymerization method and a solution polymerization method.

Examples of the thermoplastic resin include homopolymers of monomers such as vinyl chloride, ethylene, propylene, acrylic acid esters, and methacrylic acid esters, copolymers of these monomers, or at least of these monomers. Examples thereof include a copolymer of one type and another copolymerizable monomer (eg, vinyl acetate, vinylidene chloride, etc.), or a blend of these polymers. Among these, vinyl chloride resins and olefin resins are preferable from the viewpoints of weather resistance, light transmittance, economic efficiency, strength and the like.

The vinyl chloride resin has a number average degree of polymerization of about 800 to about 2500, preferably about 1000.
About 1800 polyvinyl chloride or vinyl chloride based copolymers (eg ethylene-vinyl chloride copolymers, vinyl acetate-vinyl chloride copolymers) or polyvinyl chloride or vinyl chloride based copolymers Other compatible resins based on polymers (eg polyester resin, epoxy resin, acrylic resin, vinyl acetate resin, urethane resin, acrylonitrile-styrene-butadiene copolymer resin, partially saponified polyvinyl alcohol, etc.) Blended with and the like.

Further, the olefin resin is a homopolymer of α-olefin, or a copolymer of α-olefin with a different monomer, such as polyethylene,
Examples thereof include polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, and ionomer resin. Among these, low density polyethylene, linear low density polyethylene, vinyl acetate content 3
Up to 0% by weight of ethylene-vinyl acetate copolymer is preferred.

In the coating material of the present invention, an antifogging agent is used as the component (A), a fluorine-based surfactant or a silicone-based surfactant or both are added as the component (B) to the synthetic resin (C). As the component), the lithium aluminum composite hydroxide salt of the general formula (I) is blended.

The component (A) antifogging agent is not particularly limited, but a polyhydric alcohol partial ester type composed of a polyhydric alcohol and higher fatty acids is preferable. Specific examples of such an antifogging agent include, for example, nonionic surfactants such as sorbitan monostearate, sorbitan monopalmitate, sorbitan monobehenate, esters of a condensate of sorbitan and an alkylene glycol and a fatty acid. Glycerin-based surfactants such as sorbitan surfactants, glycerin monopalmitate, glycerin monostearate, glycerin monolaurate, diglycerin monopalmitate, polyethylene glycol monostearate, polyethylene glycol monopalmitate, polyethylene glycol alkylphenyl Polyethylene glycol-based surfactants such as ether and other trimethylolpropane-based surfactants such as trimethylolpropane monostearate and pentaerythritol monopalmite DOO, such as those comprising a pentaerythritol-based surfactants and their isomers, such as pentaerythritol monostearate can be exemplified.

The fluorine-containing surfactant and silicone-containing surfactant as the component (B) act as an antifog agent, and examples of the fluorine-containing surfactant include perfluoroalkyl group or perfluoroalkenyl group. Polymers containing groups, or low molecular weight surfactants, etc.
Generally having a solubility in water of at least 0.001% by weight, preferably at least 0.01% by weight and having the ability to reduce the surface tension of water at 25 ° C. to 35 dyn / cm or less, preferably 30 dyn / cm or less. Is preferred. Further, an oxygen atom may be present in the carbon chain of the perfluoroalkyl group. Examples of commercially available fluorine-based surfactants include Unidyne DS-401, Unidyne DS-403, Unidyne DS-451 (manufactured by Daikin Industries, Ltd.), Megafac F-142D, Megafac F-177 (above, Dainippon Ink Chemical Industry Co., Ltd.), Florard FC-170, Florard FC-17
6, Fluorard FC-430 (above, Sumitomo 3M), Surflon S-141, Surflon S-145,
Surflon S-381, Surflon S-382, Surflon S-393 (all manufactured by Asahi Glass Co., Ltd.) and the like can be mentioned.

As the silicone type surfactant,
For example, polyether-modified silicone oil, carboxyl-modified silicone oil, carbinol-modified silicone oil, amino-modified silicone oil and the like can be mentioned, which generally has a solubility in water of at least 0.01% by weight, preferably at least 0.1% by weight. However, those having an ability to reduce the surface tension of water to 35 dyn / cm or less, preferably 30 dyn / cm or less at 25 ° C. are preferable. Examples of commercially available silicone-based surfactants include KF-354 (produced by Shin-Etsu Chemical Co., Ltd.) and SH-3746.
(Made by Toray Dow Corning), TSF-4445 (made by Toshiba Silicone), etc. are mentioned.

In the lithium aluminum composite hydroxide salt represented by the general formula (I) of the component (C), X in the formula represents an inorganic or organic anion, and as a compound capable of forming such anion, , For example carbonic acid, sulfuric acid,
Examples thereof include anions of oxy acids such as phosphoric acid, phosphorous acid and metaphosphoric acid, and anions of organic carboxylic acids such as acetic acid, propionic acid, adipic acid, benzoic acid and phthalic acid.

In the coating material of the present invention, the use ratio of each compounding component is the type thereof, the type of other components used in combination,
Although it can be changed depending on the kind of the synthetic resin, the component (A) is usually 1 to 4 parts by weight, preferably 1.5 to 2 parts by weight, and the component (B) is usually 100 parts by weight of the synthetic resin. 0.01-1.0 parts by weight, preferably 0.05-0.3
The weight part and the component (C) are each usually selected in the range of 1 to 20 parts by weight, preferably 5 to 10 parts by weight. If the proportion of the component (A) is too small, the antifogging property cannot be sufficiently maintained, and if it is too large, the transparency is impaired. Further, if the proportion of the component (B) is too small, the fog-preventing effect is not sufficient, and if it is too large, the high-frequency adhesiveness and heat sealability are not good. If the proportion of the component (C) is too small, the antifogging and antifog sustaining effects are insufficient, and if it is too large, the tensile strength and tear strength of the film decrease.

If necessary, the coating material of the present invention may contain additional components such as a plasticizer, a filler and a stabilizer which are usually used in synthetic resins. As this plasticizer,
Alkyl ester of aromatic polybasic acid such as dibutyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, diisononyl phthalate, diundecyl phthalate, trioctyl trimellitate, triisooctyl trimellitate , Dibutyl adipate, dioctyl adipate,
Alkyl esters of aliphatic polybasic acids such as diisononyl adipate, dibutyl azelate, dioctyl azelate, diisononyl azelate, phosphates such as tricresyl phosphate, trixylenyl phosphate, adipic acid, azelaic acid, sebacic acid, phthalate Polycarboxylic acids such as acids and ethylene glycol, 1,2-
Propylene glycol, 1,2-butylene glycol,
Molecular weight 600-8000 with polyhydric alcohols such as 1,3-butylene glycol and 1,4-butylene glycol
Polyester plasticizers such as those obtained by blocking the end of polycondensate with monohydric alcohol or carboxylic acid, epoxidized soybean oil, epoxidized linseed oil, epoxidized tall oil fatty acid-2-ethylhexyl epoxy Examples include plasticizers and chlorinated paraffins. Of these, dioctyl phthalate, dioctyl adipate, and epoxidized soybean oil are preferable.

These plasticizers may be used alone or in combination of two or more, and the compounding amount thereof is, for example, 10% in the case of vinyl chloride resin.
30-70 parts by weight, preferably 40-
If it is selected in the range of 60 parts by weight and the compounding amount is less than 30 parts by weight, the plasticizer effect is not sufficiently exerted, and if it exceeds 70 parts by weight, the mechanical properties of the film tend to deteriorate and molding tends to be difficult. .

As the filler, for example, silica, talc, aluminum hydroxide, in order to suppress stickiness of the film or to further improve heat retention,
Hydrotalcite, calcium sulfate, calcium silicate, calcium hydroxide, magnesium hydroxide, kaolin clay, mica, alumina, magnesium carbonate, sodium aluminate, conductive zinc oxide, lithium phosphate and the like are used. These fillers may be used alone or in combination of two or more.

Other additives generally include a lubricant, a heat stabilizer, an ultraviolet absorber, an antioxidant, an anti-adhesive agent, an antistatic agent and a colorant. Examples of lubricants or heat stabilizers include metal soaps, lead-based materials, Ba-Zn-based materials, and C-based materials.
Such as a-Zn type, Ca-Zn-Ba type, Ba-Mg-Al type, polyethylene wax, stearic acid, zinc stearate, barium stearate, calcium stearate, barium ricinoleate, organic phosphite Examples thereof include chelators, epoxy resins, stearic acid amides, palmitic acid amides, oleic acid amides, fatty acid amides such as ethylenebisstearamide, solid higher alcohols, and glycerin fatty acid esters.

As the ultraviolet absorber, for example, a benzotriazole type, a benzophenone type, a salicylic acid type or the like is used. Examples of benzotriazole-based compounds include 2- (2'-hydroxy-3 ', 5'-di-ter
t-Butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 '-Tert-amyl-5'-isobutylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-isobutyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'- Hydroxy-3'-isobutyl-
5'-propylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-te
rt-Butylphenyl) benzotriazole, 2-
(2'-hydroxy-5'-methylphenyl) benzotriazole, 2- [2'-hydroxy-5 '-(1,
1,3,3-tetramethyl) phenyl] benzotriazole and the like.

Further, as the benzophenone type,
2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-
Examples include hydroxy-4-octoxybenzophenone. Examples of salicylic acid-based compounds include phenyl salicylate and paraoctylphenyl salicylate.

These ultraviolet absorbers may be used alone or in combination of two or more, and benzotriazole type and benzophenone type are particularly preferable.

The agricultural coating material of the present invention uses a synthetic resin component and various compounding components in a predetermined ratio, and a ribbon blender, a Banbury mixer, a Henschel mixer, a super mixer, a single-screw or twin-screw extruder, a roll, etc. Prepared by homogenizing using a compounding machine or kneader to prepare a resin compound, and then molding into a film by a known method, for example, a calendering method, an extrusion molding method, a solution casting method, or the like. can do.

In the case of a film, if the thickness is too thin, the strength becomes insufficient, which is not preferable. On the contrary, if the film is too thick, it is inconvenient for the film forming work and the like. Therefore, it is generally 0.03 to 0.3 mm. , Preferably 0.05-0.
A range of 2 mm is suitable.

The coating material of the present invention can be provided with a dustproof layer made of a dustproof coating on the outer surface side and an antifogging layer made of an antifogging coating on the inner surface side. Further, the agricultural coating material of the present invention may be a laminated film composed of two layers or three layers. In particular, in the case of a three-layer laminated film, a synthetic resin composition in which the component (C) is mixed only in the intermediate layer is used. It is preferably used.

[0026]

The agricultural resin coating material of the present invention has an antifogging property,
It has improved fog-proof durability, has no bleed-out for a long period of time, and has good transparency, so it is suitable for use in greenhouses and tunnel cultivation.

[0027]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. The parts indicating the amounts of each component used are parts by weight. The characteristics of each film sample were judged by the following test methods or evaluation criteria.

(1) Anti-fog property and anti-fog property In an experimental field in Ageo City, Saitama Prefecture, a film sample was tested in September 1993 with a floor area of 50 cm × 300 cm and a height of 70 c.
m, the ceiling was spread in a mini-house with a slope and exposed until March 1994, and the fog resistance and fog resistance of the film sample were evaluated according to the following criteria. (A) Antifogging property ⊚: There are no spots where droplets are formed ◯: Drops are formed within a range not exceeding 10% of the whole △: Drops are formed within a range of 10 to 50% of the whole ×: Whole (B) Fog resistance is not observed +: Slight fog is generated ++: Slight fog is generated +++: Fog is considerably generated It has occurred

(2) Transparency The film sample was stored in a temperature-controlled room at 23 ° C., the haze value was obtained with a haze meter, and evaluated according to the following criteria. ◯: Haze value less than 15% Δ: Haze value 15 to 30% ×: Haze value over 30%

Example 1 100 parts of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 15% and an MI of 1.5 was added with 0.1 AO-50 (trade name, phenolic antioxidant manufactured by Asahi Denka Co., Ltd.). Part, 2-hydroxy-4-methoxybenzophenone (UV absorber)
0.1 part, LA-63 (trade name, light stabilizer manufactured by Asahi Denka Co., Ltd.)
0.1 part, an equal amount mixture of diglycerin monostearate and sorbitan monostearate (anti-fog agent) 1.5 parts, D
Lithium aluminum represented by S-401 (trade name, fluorine-based surfactant manufactured by Daikin Co., Ltd., a fog inhibitor) and 0.1 part of the following formula [Al ₂ Li (OH) ₆ ] ₂ CO ₃ · 1.6H ₂ O Complex hydroxide salt 5.
After blending 0 parts, the mixture was stirred and kneaded with a Henschel mixer, and the resulting kneaded product was fed to a twin-screw extruder to obtain a processing temperature of 1
Pellets were made at 50 ° C. The pellets were inflation-molded to obtain a film having a width of 500 mm and a thickness of 0.1 mm.

Example 2 In the same manner as in Example 1 except that the lithium aluminum composite hydroxide salt was replaced with a compound represented by the following formula [Al ₂ Li (OH) ₆ ] ₂ SO ₄ .1.2H ₂ O. A film of the same size was obtained.

Example 3 100 parts of low-density polyethylene having MI = 2.5 (manufactured by Nippon Unicar Co., Ltd.), 0.1 part of AO-50 (trade name, phenolic antioxidant manufactured by Asahi Denka Co., Ltd.), and Visorb 510
(Trade name, UV absorber manufactured by Kyodo Pharmaceutical Co., Ltd.) 0.1 part, LA
-63 (trade name, light stabilizer manufactured by Asahi Denka Co., Ltd.) 0.1 part, diglycerin monostearate / glycerin monolaurate / glycerin monostearate (7/2/1) (anti-fog agent) 1.5 parts , KF-354 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd., silicone-based surfactant, antifog agent) 0.3 part and the following formula [Al ₂ Li (OH) ₆ ] ₂ CO ₃ · 1.8H ₂ O. Lithium aluminum complex hydroxide salt 1.
After blending 0 parts, the mixture was stirred and kneaded with a Henschel mixer, and the resulting kneaded product was fed to a twin-screw extruder to obtain a processing temperature of 1
Pellets were made at 50 ° C. The pellets were inflation-molded to obtain a film having a width of 500 mm and a thickness of 0.1 mm.

Example 4 A film of the same size was obtained in the same manner as in Example 3 except that the amount of the lithium aluminum composite hydroxide salt used was changed to 10 parts.

Example 5 100 parts of polyvinyl chloride resin (p = 1300) was mixed with PO.
P 45 parts, TCP 5 parts, Ba / Zn stabilizer 2.0 parts,
2-Hydroxy-4-methoxybenzophenone (UV absorber) 0.2 parts, ethylene bis stearamide 0.3
Part, sorbitan monopalmitate 2.0 parts, DS-40
1 (trade name, fluorine-based surfactant manufactured by Daikin Co., Ltd., anti-fog agent) 0.1 part and the following formula [Al ₂ Li (OH) ₆ ] ₂ CO ₃ · 1.6H ₂ O lithium aluminum composite water represented by Oxide salt 5.
After blending 0 parts, the mixture was stirred and kneaded with a Henschel mixer, and the resulting kneaded product was fed to a twin-screw extruder to obtain a processing temperature of 1
Pellets were made at 50 ° C. The pellets were inflation-molded to obtain a film having a width of 500 mm and a thickness of 0.1 mm.

Comparative Example 1 A film of the same size was obtained in the same manner as in Example 1 except that the lithium aluminum composite hydroxide salt was not used.

Comparative Example 2 A film of the same size was obtained in the same manner as in Example 3 except that the lithium aluminum composite hydroxide salt was not used.

Comparative Example 3 A film of the same size was obtained in the same manner as in Example 5 except that the lithium aluminum composite hydroxide salt was not used.

Physical properties of the film samples of Examples and Comparative Examples were evaluated. The results are shown in Table 1.

[0039]

[Table 1]

From the above, the film sample of the comparative example is the earliest, and after 2 months from the time of spreading, it becomes drip, and after 3 months, a little fog occurs and the haze value increases. Even if the film is good, droplets are formed after 4 months, and fog is formed after 6 months, and the haze value is increased. On the other hand, all the films of the present invention are excellent in all properties. I understand.

Claims (1)

[Claims] 1. To 100 parts by weight of a synthetic resin, (A) 1 to 4 parts by weight of an antifogging agent, (B) 0.01 to 1.0 of a fluorine-based surfactant or a silicone-based surfactant, or both of them.
Parts by Weight and (C) General Formula [Al ₂ Li (OH) ₆ ] _n X.mH ₂ O (X in the Formula represents an inorganic or organic anion, n represents the valence of the anion X, and m represents a number of 3 or less. ) A mixture of 1 to 20 parts by weight of a lithium aluminum complex hydroxide salt represented by the formula (1) is used as a synthetic resin coating material for agriculture.