JP2002129141A - Infrared absorber and agricultural film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared absorber that has a high infrared absorptivity, is well dispersible in a resin, has a refractive index close to that of a resin, and, when added to a resin, can form a composition that can give a film excel lent in heat insulation properties, transparency, acid resistance, and productivity and to provide an agricultural film. SOLUTION: This absorber contains an effective component being a hydrotalcite compound represented by formula I: [(M2+)aAl2](OH)x]-(SO4)y1(CO3)y2(OH)y3.bH2O [wherein M2+ is a divalent metal; and (a), (b), (x), y1, y2, and y3 are in the ranges: 2<=a<=8, 0<=b<=4, x=2(a+2), y1>0, y2>0, y3>=0, and (y1+y2+y3)/2=1].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a compound of the formula (I) [(M ²⁺ ) _a Al ₂ (OH) _x ] (SO ₄ ) _y1 (CO ₃ ) _y2 (OH) _y3 · bH ₂ O (I) ( ^Wherein , M ²⁺ is a divalent metal, a, b, x, y1, y2,
y3 is 2 ≦ a ≦ 8, 0 ≦ b ≦ 4, x = 2 (a + 2),
y1> 0, y2> 0, y3 ≧ 0, y1 + y2 + y3 / 2
= 1) in the form of a hydrotalcite-based compound as an active ingredient, and an agricultural film formed by mixing the resin with a resin and molding the same. The infrared absorber comprising the hydrotalcite-based compound of the present invention has a high infrared absorption ability,
Excellent dispersibility with resin, refractive index is close to that of resin, and acid resistance and productivity are good, so it is easy to mix with resin, easy to process resin, and keeps heat when formed into film It has excellent properties, transparency and pesticide resistance, and is suitable as an agricultural film.

[0002]

2. Description of the Related Art Agricultural films used in greenhouse cultivation such as houses and tunnels allow sunlight to pass efficiently with high transmittance in the daytime, while absorbing and reflecting infrared rays radiated from the ground and plants at nighttime. It is required to have such characteristics that it is not released out of a house or a tunnel. The range where the emissivity of infrared rays emitted from the ground or plants is large is 5 to 25 μm
Is known. 5-25 μm for agricultural film, especially 10 μm with maximum emissivity
It is necessary to be able to absorb infrared rays of a nearby wavelength.
Conventionally, in the agricultural film, as an infrared absorber,
Magnesium carbonate, magnesium silicate, silicon dioxide, aluminum oxide, barium sulfate, calcium sulfate, magnesium hydroxide, aluminum hydroxide, calcium hydroxide, phosphate, silicate, hydrotalcites and the like have been used. However, the above-mentioned conventional inorganic powders each have advantages and disadvantages, and there is no one that sufficiently satisfies the above-mentioned various physical properties. For example, silicon dioxide, magnesium silicate, etc. have excellent infrared absorbing ability, but have problems in refractive index, dispersibility, etc., and as a result, the translucency of the film is impaired, so it is not suitable as an agricultural film It was something. Further, hydrotalcites are relatively excellent in dispersibility, refractive index and the like, but are not sufficiently satisfactory in infrared absorption ability. Further, Japanese Patent Application Laid-Open No. 7-300313 discloses a technique of using a lithium aluminum composite hydroxide salt as a heat insulator for agricultural films. This hydroxide salt has a refractive index
Since the value of 1.55 is far from the value of about 1.50 of the polyolefin resin, there was a defect that the transparency was not good. Furthermore, various attempts have been made to increase the heat retention performance by inserting a silica component or a phosphoric acid component between the layers, but these ions are inferior in ion exchange ability with other acids, and are resistant to pesticides and the like. In terms of sex, higher performance was demanded. Further, there has been a demand for a more productive heat insulating agent to be incorporated into agricultural films.

[0003]

DISCLOSURE OF THE INVENTION The present invention has a high infrared absorbing ability, a good dispersibility when blended with a resin, a refractive index close to the refractive index of the resin, and a heat retaining property when formed into a film. An object of the present invention is to provide an infrared absorber and an agricultural film which are excellent in transparency, and are excellent in acid resistance and productivity.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, the following formula (I) and formula (I) [(M ²⁺ ) _a Al ₂ (OH) _x ] (SO ₄ ) _y1 (CO ₃ ) _y2 (OH) _y3 · bH ₂ O (I) (where M ²⁺ is a divalent metal, a, b, x, y1, y2,
y3 is 2 ≦ a ≦ 8, 0 ≦ b ≦ 4, x = 2 (a + 2),
y1> 0, y2> 0, y3 ≧ 0, y1 + y2 + y3 / 2
= 1), and found that an infrared absorber characterized by containing a hydrotalcite-based compound represented by the formula (1) as an active ingredient could solve the above problems, and completed the present invention. That is, the present invention is an infrared absorbent comprising a hydrotalcite-based compound represented by the above formula (I) [hereinafter referred to as compound (I)] as an active ingredient. Compound (I) of the present invention
Has a basic structure comprising a hydrotalcite structure in which an anion is introduced into an intermediate layer of a composite hydroxide layer composed of Al and a divalent metal. The divalent metal is not particularly limited, but Mg, Zn, Ca, and the like are more preferable because they are easily introduced, are white, and satisfy transparency when blended into a film. Sulfate ions between layers have a function of expanding the layers to make the refractive index close to that of the polyolefin resin, and carbonate ions and hydroxide ions have a function of exchanging with other acid ions to impart acid resistance. it is conceivable that. In addition, by coexisting sulfate ions between the layers, the acid resistance may be improved as compared with the case of only carbonate ions. This is presumably because sulfate ions further stabilize the basic layer structure of the hydrotalcite and suppress deterioration of the film appearance (decrease in transparency) due to structural destruction (dissolution) of the infrared absorber.

A represents a carbonate ion and / or a sulfate ion. The infrared absorbent of the present invention, that is, the infrared absorbent characterized by containing the compound (I) as an active ingredient, is fine particles and highly dispersed when used in a film such as an agricultural film. It is preferable to use those which are crystalline and have relatively developed crystals. Therefore, the average secondary particle diameter is preferably 3 μm or less, more preferably 1 μm or less. Also,
The BET specific surface area is preferably not more than 50 m ² / g, more preferably not more than 20 m ² / g.

The process for producing the compound (I) of the present invention will be described below with reference to M ²⁺
Is Mg as one specific example.

First, a carbonate ion type hydrotalcite compound used as a starting material for producing the compound (I) of the present invention is produced by the following method. Specifically, it can be produced by subjecting aluminum hydroxide to heat treatment with magnesium carbonate such as magnesium carbonate or basic magnesium carbonate and sodium bicarbonate and / or sodium carbonate in an aqueous medium. In addition, a water-soluble aluminum compound and a water-soluble magnesium compound, sodium bicarbonate and / or sodium carbonate, and an alkaline solution such as
It is also obtained by subjecting a reaction in an aqueous solution while maintaining a pH of about 10 to a heat treatment.

As the water-soluble aluminum, sodium aluminate, aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum acetate and the like can be used. As the water-soluble magnesium compound, magnesium chloride,
Magnesium nitrate, magnesium sulfate, magnesium bicarbonate and the like can be used.

The temperature range of the heat treatment is preferably from room temperature to
A suitable temperature up to 200 ° C., more preferably 9 ° C.
The temperature is 0 to 160 ° C, particularly preferably 110 to 160 ° C. If the treatment temperature is lower than room temperature, the degree of crystallization is undesirably low.

Next, sulfuric acid is added to the slurry of the carbonate ion-type hydrotalcite compound obtained above to make the liquid once acidic, and then the liquid is returned to the alkali side again with an alkaline solution such as caustic soda. Gives compound (I) of the present invention.

The concentration of the sulfuric acid to be added is not particularly limited, but it is preferable that the concentration is not more than 20% by weight in view of preventing the crystal from collapsing. Also, sulfuric acid addition is pH
It is preferable to add until 4.0 to 7.0, more preferably pH 5.0 to pH 6.0.

Although the alkali solution is not particularly limited, caustic soda of 25% by weight or less is preferable in view of industrialization. In addition, the addition of the alkaline solution is carried out at pH 8.0-1.
It is preferable to add until 3.0, more preferably pH 9.0 to 12.0.

The desired compound is obtained by washing the above compound with water. The ratio of interlayer ions can also be controlled by washing with an appropriate concentration of sodium hydroxide, sodium carbonate or sodium bicarbonate.

The infrared absorbing agent of the present invention can be made more excellent in dispersibility by performing a surface treatment with a coating agent. As a coating agent, for example,
One or more selected from higher fatty acids, higher fatty acid salts, esters of higher fatty acid alcohols and phosphoric acid, waxes, nonionic surfactants, cationic surfactants or coupling agents, preferably Examples include higher fatty acids, higher fatty acid salts, phosphate esters of higher fatty acid alcohols, nonionic surfactants, cationic surfactants, and coupling agents.

The higher fatty acids include, for example, lauric acid, palmitic acid, oleic acid, stearic acid, capric acid, myristic acid, and linoleic acid. The higher fatty acid salts include, for example, sodium salts of the above-mentioned higher fatty acids, Potassium salts and the like can be mentioned. Phosphate esters of higher fatty acid alcohols, for example, alkyl ether phosphoric acid such as lauryl ether phosphoric acid, stearyl ether phosphoric acid, oleyl ether phosphoric acid, dialkyl ether phosphoric acid, alkyl phenyl ether phosphoric acid, dialkyl phenyl ether phosphoric acid and the like, or Examples thereof include alkyl ether phosphates such as sodium oleyl ether phosphate and potassium stearyl ether phosphate.

Examples of the nonionic surfactant include, for example,
Palm oil fatty acid monoethanolamide, alkylolamides such as lauric acid diethanolamide, polyoxyalkylphenyl ethers such as polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether,
Polyethylene glycol fatty acid esters such as polyethylene glycol distearate, sorbitan monocaprate, sorbitan monostearate, sorbitan fatty acid esters such as sorbitan distearate, polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate, polyoxy Examples thereof include ethylene sorbite fatty acid esters, polyoxyethylene polyoxypropylene alkyl ethers, and glycol ethers.

As the cationic surfactant, for example,
Alkyltrimethylammonium salts such as lauryltrimethylammonium chloride, cetyltrimethylammonium bromide and stearyltrimethylammonium chloride; and alkyldimethylbenzylammonium salts such as stearyldimethylbenzylammonium chloride, benzalkonium chloride and lauryldimethylbenzylammonium chloride. it can.

Examples of the amphoteric surfactant include alkyl betaines such as coconut oil alkyl betaine, alkylamide betaines such as lauryl dimethylaminoacetic acid betaine, and midazolines such as Z-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolyme betaine. And glycines such as polyoctylpolyaminoethylglycine.

Examples of the coupling agent include a silane coupling agent, an aluminum coupling agent, a titanium coupling agent, a zirconium coupling agent, and the like.

One or more of the above-mentioned coating agents can be used simultaneously. The amount of the coating agent added is 0.1 to 10% by weight, preferably 0.5 to 6% by weight. Less than 0.1% by weight has poor dispersibility, 10% by weight
Although the above effects are sufficient, they are not economically advantageous. The surface treatment can be facilitated by a wet method or a dry method according to a conventional method.

The second aspect of the present invention is a resin composition, an agricultural film and a method for producing the same, which contain the infrared absorbent of the present invention. The agricultural film of the present invention can be manufactured by the method described below. First, the resin and the infrared absorbent of the present invention are charged into a mixer such as a ribbon blender, a Banbury mixer, a super mixer, a Henschel mixer or the like according to a conventional method, and after mixing, an extruder, a Banbury mixer, a pressure kneader, etc. And a resin composition is prepared by melt-kneading.

The amount of the infrared absorber used is preferably 1 to 50 parts by weight, more preferably 1 to 50 parts by weight, based on 100 parts by weight of the resin.
20 parts by weight. If the amount is less than 1 part by weight, infrared rays cannot be sufficiently absorbed, and if the amount exceeds 50 parts by weight, the translucency and mechanical strength of the agricultural film decrease.

As the resin, polyvinyl halides such as polyvinyl chloride and polyvinylidene chloride, halogenated polyethylene, halogenated polypropylene, or vinyl chloride-vinyl acetate, vinyl chloride-ethylene, vinyl chloride-
Propylene, vinyl chloride-styrene, vinyl chloride-isobutylene, vinyl chloride-vinylidene chloride, vinyl chloride-
A copolymer comprising a combination of styrene-acrylonitrile, vinyl chloride-butadiene, vinyl chloride-chlorinated propylene, vinyl chloride-vinylidene chloride-vinyl acetate, vinyl chloride-maleate, vinyl chloride-methacrylate, vinyl chloride-acrylonitrile, and the like. Polymers, or polymers or copolymers of olefins such as olefinic ethylene, propylene, butene-1, and vinyl acetate, for example, LLPE, polyethylene such as LDPE, polypropylene, ethylene-propylene copolymer,
Ethylene-α-olefin copolymers such as ethylene-butene-1 copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-hexene copolymer, ethylene-vinyl acetate copolymer, ethylene-acryl Acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-
Examples thereof include a vinyl acetate-methyl methacrylate copolymer and an ionomer resin. Among them, polyethylene, ethylene, ethylene-α-olefin copolymer, and ethylene-vinyl acetate copolymer having a vinyl acetate content of 25% by weight or less are more preferable in view of transparency, weather resistance, and price.

The resin composition obtained by the above-mentioned mixing, melting and kneading may be subjected to a conventional method such as inflation processing,
By forming the film by a method such as calendering and T-die processing, a film such as an agricultural film can be obtained.

Further, a laminated film having at least one film using the resin composition containing the infrared absorbent of the present invention can be formed. Specifically, a multilayer film can be formed by providing another resin layer on one side or both sides. Such a multilayer film can be produced by a conventional method, for example, a lamination method such as dry lamination and heat lamination, or a co-extrusion method such as T-die co-extrusion and inflation co-extrusion.

In the production of the agricultural film of the present invention, if necessary, various conventional additives for resins, for example, plasticizers, lubricants, light stabilizers, antioxidants, antistatic agents, pigments, ultraviolet absorbers, antifogging agents Agents, anti-fog agents, heat stabilizers, anti-blocking agents, dyes or warming agents and the like can be added.

Examples of the plasticizer include low-molecular-weight polyhydric alcohol plasticizers such as glycerin, ethylene glycol, triethylene glycol and sorbitol; phthalate plasticizers such as dioctyl phthalate (DOP) and dimethyl phthalate; and phosphate esters. Plasticizers, paraffin plasticizers, and wax plasticizers. Among these, polyhydric alcohols also have an antifogging effect on the film.

Examples of the lubricant include fatty acids such as stearic acid, oleic acid, palmitic acid and the like, metal salts thereof, fatty acid amides derived from fatty acids, waxes such as polyethylene wax, liquid paraffin, esters such as glycerin fatty acid ester and the like. Alcohol and the like can be mentioned.

Examples of the light stabilizer include hindered amine compounds, cresols, melamines, benzoic acid and the like.

Examples of hindered amine light stabilizers include 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6,6-tetramethyl-4
-Piperidyl benzoate, N- (2,2,6,6-tetramethyl-4-piperidyl) dodecylsuccinimide, 1
-(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl) -2,2,6,6-tetramethyl-4-piperidyl- (3,5-di-tert-butyl-4- Hydroxylphenyl) propionate, bis
(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (1,2,2,6,6- Pentamethyl-4-piperidyl) -2-butyl-2- (3,5-
Di-tert-butyl-4-hydroxybenzyl) malonate, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine, tetra (1,2,2,
6,6-pentamethyl-4-piperidyl) butanetetracarboxylate, tetra (2,2,6,6-tetramethyl-
4-piperidyl) butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) di (tridecyl) butanetetracarboxylate, bis
(2,2,6,6-tetramethyl-4-piperidyl) di (tridecyl) butanetetracarboxylate, 3,9-bis {1,1-dimethyl-2- [tris (2,2,6,6- Tetramethyl-4-piperidyloxycarbonyloxy)
Butylcarbonyloxy] ethyl {-2,4,8,10-tetrooxaspiro [5,5] undecane, 3,9-bis {1,1-dimethyl-2- [tris (1,2,2,6, 6-
Pentamethyl-4-piperidyloxycarbonyloxy) butylcarbonyloxy] ethyl {-2,4,8,10
-Tetraoxaspiro [5,5] undecane, 1,5,8,
12-tetrakis @ 4,6-bis [N- (2,2,6,6-
Tetramethyl-4-piperidyl) butylamino] -1,
3,5-triazin-2-yl {-1,5,8,12-tetraazadodecane, 1- (2-hydroxyethyl) -2,
2,6,6-tetramethyl-4-piperidinol / dimethyl succinate condensate, 2-tert-octylamino-4,6
-Dichloro-s-triazine / N, N'-bis (2,2,6,
6-tetramethyl-4-piperidyl) hexamethylenediamine condensate, N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine / dibromoethane condensate, and the like. it can. The amount of the light stabilizer to be added is preferably 0.02 to 5 parts by weight with respect to 100 parts by weight of the resin.

Examples of the antioxidant include phenol-based, phosphorus-based, and sulfur-based antioxidants.

Examples of the phenolic antioxidant include 2,6-di-tert-butyl-p-cresol and 2,6-di-tert-butyl-p-cresol.
6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-butyl-4-hydroxyphenyl) -propionate, distearyl (3,5-
Di-tert-butyl-4-hydroxybenzyl) phosphonate, thiodiethylene glycol bis [(3,5-di-
tert-butyl-4-hydroxyphenyl) propionate], 1,6-hexamethylenebis [(3,5-di-te
rt-butyl-4-hydroxyphenyl) propionate], 1,6-hexamethylenebis [(3,5-di-te
rt-butyl-4-hydroxyphenyl) propionic amide], 4,4'-thiobis (6-tert-butyl-m-cresol), 2,2'-methylenebis (4-methyl-6-
tert-butylphenol), 2,2′-methylenebis (4
-Ethyl-6-tert-butylphenol, bis [3,3
-Bis (4-hydroxy-3-tert-butylphenyl)
Butyric acid] glycol ester, 4,4′-butylidenebis (6-tert-butyl-m-cresol), 2,2′-ethylidenebis (4,6-di-tert-butylphenol), 2,
2'-ethylidenebis (4-sec-butyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4
-Hydroxy-5-tert-butylphenyl) butane, bis [2-tert-butyl-4-methyl-6- (2-hydroxy-tert-butyl-5-methylbenzyl) phenyl]
Terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-di-tert-butyl-4-) Hydroxybenzyl) isocyanurate,
1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene,
1,3,5-tris [(3,5-di-tert-butyl-4-
[Hydroxyphenyl) propionyloxyethyl] isocyanurate, tetrakis [methylene-3- (3,5-
Di-tert-butyl-4-hydroxyphenyl) propionate] methane, 2-tert-butyl-4-methyl-6-
(2-acryloyloxy-3-tert-butyl-5-methylbenzyl) phenol, 3,9-bis {1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-
5-methylphenyl) propionyloxy] ethyl}-
2,4,8,10-Tetraoxaspiro [5,5] undecane, triethylene glycol bis [(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] and the like can be mentioned.

Examples of the phosphorus-based antioxidants include trisnonylphenyl phosphite and tris (2,4-di-
tert-butylphenyl) phosphite, tris [2-te
rt-butyl-4- (3-tert-butyl-4-hydroxy-5-methylphenylthio) 5-methylphenyl] phosphite, tridecyl phosphite, octyl diphenyl phosphite, di (decyl) monophenyl phosphite, Monodecyldiphenyl phosphite, mono (dinonylphenyl) bis (nonylphenyl) phosphite, di (tridecyl) pentaerythritol diphosphite,
Distearyl pentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-te
rt-butyl-4-methylphenyl) pentaerythritol diphosphite, tetra (tridecyl) isopropylidene diphenol diphosphite, tetra (tridecyl) isopropylidene diphenol diphosphite, tetra (C12-16 mixed alkyl) -4, 4'-n-butylidenebis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butanetriphos Fight, Tetrakis (2,4
-Di-tert-butylphenyl) biphenylenediphosphonite, 2,2'-methylenebis (4,6-di-tert-butylphenyl) (octyl) phosphite and the like.

Examples of the sulfur-based antioxidants include dialkyldithiopropionates such as dilauryl, dimyristyl and distearyl of thiodipropionic acid and β-polyols such as pentaerythritol tetra (β-dodecylmercaptopropionate). -Alkyl mercaptopropionates. The amount of the antioxidant is preferably about 0.01 to 3%.

Examples of the antistatic agent include polyoxyethylene / alkylamine, polyglycol ether, nonionic activator and cationic activator.

As the pigment, those having high permeability are preferable.

Examples of the ultraviolet absorber include benzophenone type, benzotriazole type, salicylate type, substituted oxalinides, cyanoacrylates and the like.

As the benzophenone type, for example,
4-dihydroxybenzophenone, 2-hydroxy-4
And 2-hydroxybenzophenones such as -methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis (2-hydroxy-4-methoxybenzophenone).

As benzotriazoles, for example,
2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-
tert-butylphenyl) benzotriazole, 2-
(2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl)
-5-chlorobenzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dicumylphenyl) benzotriazole, 2,2 '-Methylenebis (4
2- (2'-hydroxyphenyl) benzotriazoles such as -tert-octyl-6-benzotriazole) phenol.

Examples of salicylates include, for example,
Phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzoate, hexadecyl-3,5-di-tert-butyl- Benzoates such as 4-hydroxybenzoate can be mentioned.

The substituted oxalinides include, for example, 2
And substituted oxalinides such as -ethyl-2'-ethoxyoxalinide and 2-ethoxy-4'-dodecyloxanilide.

As the cyanoacrylates, for example,
Examples thereof include cyanoacrylates such as ethyl-α-cyano-β, β-diphenylacrylate and methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate.

As the antifogging agent, a nonionic, anionic or cationic surfactant can be suitably used. Specifically, sorbitan monostearate, sorbitan monopalmylate, sorbitan fatty acid esters such as sorbitan monobehenate, glycerin monolaurate, glycerin monostearate, glycerin monopalmite,
Polyglycol surfactants such as diglycerin dilaurate, diglycerin distearate, diglycerin monopalmite, glycerin fatty acid esters such as triglycerin monostearate, polyethylene glycol surfactants such as polyethylene glycol monostearate, And alkylene oxide adducts thereof, polyoxyalkylene ethers, esters with organic acids such as sorbitans and glycerins, and the like.

As the antimist agent, a fluorine antimist agent or a silicone antimist agent which is commonly used in conventional olefin resin films for agricultural use can be blended. For example, a low-molecular or high-molecular compound containing a perfluoroalkyl group or a perfluoroalkenyl group, has a solubility in water of at least 0.01% by weight, and has a surface tension of water of not more than 35 dyn / cm at 25 ° C., preferably 30 dyn / cm.
Those having the ability to reduce the density to below cm are preferred. Further, the perfluoroalkyl group may have an oxygen atom interposed in its carbon chain.

Examples of the fluorine-based antimist agent include commercially available products Unidyne DS-401, Unidyne DS-403, Unidyne DS-451 (all manufactured by Daikin Industries, Ltd.) and Megafac F-177 (all manufactured by Dainippon Ink. Chemical Industry Co., Ltd.), Florard FC-170, Florard FC-176, Florard FC
-430 (all manufactured by Sumitomo 3M Limited), Surflon S-14
1, Surflon S-145, Surflon S-381, Surflon S-382, Surflon S-393 (all manufactured by Asahi Glass Co., Ltd.) and the like.

Examples of the silicone-based antifog include polyether-modified silicone oil, carboxyl-modified silicone oil, carbinol-modified silicone oil, amino-modified silicone oil and the like, and generally have a solubility in water of at least 0.1% by weight. Preferably, it has the ability to reduce the surface tension of water at 25 ° C. to 35 dyn / cm or less. Examples of commercially available silicone surfactants include KF-354 (manufactured by Shin-Etsu Chemical Co., Ltd.) and SH-374.
6 (Dow Corning Toray), TSF-4445 (manufactured by Toshiba Silicone Co., Ltd.) and the like. The compounding amount of the antifog agent is preferably in the range of about 0.1% to 5% with respect to 100 parts by weight of the resin.

Examples of the heat stabilizers include tin-based, lead-based, calcium-zinc-based, barium-zinc-based and other complex metal fatty acid-based stabilizers, etc., which are particularly blended with vinyl chloride-based resins.

Further, other heat insulators such as magnesium carbonate, magnesium silicate, silicon dioxide, aluminum oxide, barium sulfate, calcium sulfate, magnesium hydroxide, aluminum hydroxide, calcium hydroxide, phosphate,
Silicates, hydrotalcites and the like can also be used as long as the transparency of the film is not impaired.

One or more of the above-mentioned various additives may be appropriately selected and blended. The compounding amount is preferably in a range that does not degrade the properties of the film, and there is no particular limitation as long as it is within this range.

The agricultural film of the present invention comprises: 1) resin 1
1 to 50 parts by weight of the hydrotalcite-based compound of the present invention is added to 00 parts by weight, 2) 1 to 50 parts by weight of the hydrotalcite-based compound of the present invention is added to 100 parts by weight of the resin. Parts and a hindered amine light stabilizer in an amount of 0.02 to 5 parts by weight, and 3) 100 parts by weight of the resin, 1 to 50 parts by weight of the hydrotalcite-based compound of the present invention. Agricultural film characterized by blending 0.02 to 5 parts by weight of antifog agent, 4) 1 to 50 parts by weight of hydrotalcite-based compound of the present invention and 0.1 part by weight of antifog agent per 100 parts by weight of resin.
Agricultural film characterized by blending with 2 to 5 parts by weight.

【Example】

Example 1 2488 g of ion-exchanged water, aluminum hydroxide slurry (Al ₂ O ₃ content: 13.3%) 3
60.1 g, basic magnesium carbonate 54.1 g (Mg
O content 42%), magnesium hydroxide 86.1 g (Mg
O content 66%) and 11.8 g of heavy saw were mixed and subjected to hydrothermal treatment at 160 ° C. for 18 hours in a 5 L autoclave. After the heat treatment, the slurry was cooled to 65 ° C., and 684 mL of a 1% solution of sodium salt of stearic acid phosphate was used.
For surface treatment. 8 for surface-treated slurry
Weight percent sulfuric acid was added dropwise until pH 5.5. Then
25% caustic soda was added dropwise, and the slurry pH was adjusted to 9.5 to 1
Adjusted to 0.5. The slurry after the pH adjustment was suction-filtered with a Nutsche, and 6.75 from the top of the filter cake.
L of water was poured and washed. The obtained filter cake is dried at 110 ° C. for 16
After drying for an hour, the mixture was crushed and sieved with a No. 100 sieve. When the obtained white powder was subjected to chemical analysis, [Mg _4.20 Al ₂ (OH)
_12.40 ] (SO ₄ ) _0.90 (CO ₃ ) _0.06 (OH) _0.08 · 2.1H ₂ O Further, the BET specific surface area was 6.9 m ² / g, and the average particle size was 1.0 μm.

Example 2 The filter cake obtained in the same manner as in Example 1 was dried at 210 ° C. for 3 hours using a high-temperature dryer, crushed, and sieved with a No. 100 sieve. The obtained white powder was _subjected to chemical analysis to find that [Mg _4.22 Al ₂ (OH) _12.44 ] (SO ₄ )
The composition was _0.86 (CO ₃ ) _0.08 (OH) _0.12 · 0.3H ₂ O. Also,
The BET specific surface area is 7.2 m ² / g, and the average particle size is
It was 1.1 μm.

Example 3 1423.6 g of sulfuric acid band (A
l ₂ O ₃ content 7.1%) and 921.2 g of magnesium chloride
(MgO content 19.8%) was dissolved in ion-exchanged water to make a total volume of 5 L, which was used as an acid solution. 75.0 g of soda ash
(Content 99.5%) and 1853.2 g of 25% caustic soda
Was dissolved in ion-exchanged water to make a total volume of 5 L, which was used as an alkaline solution. 320 g of 25% caustic soda was dissolved in ion-exchanged water to make a total volume of 1 L, which was used as a pH adjusting solution. p
400 mL of ion-exchanged water is placed in a reaction vessel equipped with an H composite electrode and capable of collecting a reaction solution overflowing at 800 mL, and the above acid solution and alkali solution are simultaneously added at a rate of 20 mL / min with vigorous stirring. did. At this time,
A pH adjusting solution was appropriately added so that the slurry pH was in the range of 9.0 to 9.4. The collected overflow solution is subjected to suction filtration with a nutsche every 2 L, and 0.05 from the top of the filter cake.
1 L of a 3 mol / L soda ash solution and then 2 L of ion-exchanged water were poured and washed. This operation was repeated several times until the acid solution and the alkaline solution disappeared. An appropriate amount of ion-exchanged water is added to the filter cake thus obtained to form a slurry,
A slurry of 3.51% as Al ₂ O ₃ was obtained. 2137.9 g of ion-exchanged water was added to 862.1 g of this slurry to make a total amount of 3000 g, followed by hydrothermal treatment at 160 ° C. for 24 hours in a 5 L autoclave. After the heat treatment, the slurry was cooled to 70 ° C., and 8% by weight sulfuric acid was added dropwise until the pH reached 5.5. Next, 25% caustic soda was added dropwise to adjust the slurry pH to 9.5 to 10.5. While maintaining the pH-adjusted slurry at 70 ° C., 453 mL of a 1% solution of sodium stearate was added to perform surface treatment. The surface-treated slurry was suction-filtered with a Nutsche, and furthermore, 0.01 mol /
1 L of soda ash solution and then 4.5 L of water were poured and washed. The obtained filter cake is heated at 160 ° C.
, And then crushed and sieved with a No. 100 sieve.
When the obtained white powder was subjected to chemical analysis, [Mg _4.10 Al ₂ (O
H) _12.20 ] (SO ₄ ) _0.54 (CO ₃ ) _0.46 · 0.9H ₂ O.
The BET specific surface area was 15.3 m ² / g, and the average particle size was 0.7 μm.

Example 4 An agricultural film was prepared using the hydrotalcite-based compound obtained in Example 1, and the effect was confirmed. EVA resin (PES-40
0, manufactured by Nippon Unicar) 10 parts by weight of the hydrotalcite-based compound obtained in Example 1
Roll kneading was performed at 50 ° C. and pressed to obtain a 100-μm agricultural film. The transparency and heat retaining effect of this agricultural film were measured. The heat retention was evaluated by a heat retention index measured by the following method. The infrared absorption of the resulting film was measured every 20 cm ^-1 in the range of 2000~400cm ^-1, 1
The corrected extinction coefficient at each wave number was determined by correcting the thickness to 00 microns. The black body relative radiant energy absorption rate was calculated by multiplying the corrected extinction coefficient by the black body relative radiant energy at 15 ° C. corresponding to each wave number. The black body relative radiant energy absorptance of each wave number was integrated, and the value was divided by the total black body relative radiant energy of 2000 to 400 cm ^-1 to obtain a heat retention index. The higher the heat retention index, the higher the heat retention effect. Transparency was measured using a spectrophotometer (manufactured by JASCO Corporation) using the total light transmittance and haze value.
(Haze) was measured and evaluated based on the value. As the total light transmittance is closer to 100, the visible light transmittance of the film is better, and as the haze value (cloudiness) is smaller, it means that the haze is smaller. Table 1 shows the heat retention index, total light transmittance, and haze value of this film.

Example 5 A 100-micron agricultural film was prepared in the same manner as in Example 4 using the hydrotalcite-based compound obtained in Example 2, and the transparency and the heat retaining effect were measured. Table 1 shows the heat retention index, total light transmittance, and haze value of this film.

Example 6 A 100-micron agricultural film was prepared in the same manner as in Example 4 using the hydrotalcite-based compound obtained in Example 3, and the transparency and the heat retaining effect were measured. Table 1 shows the heat retention index, total light transmittance, and haze value of this film.

Comparative Example 1 Using a commercially available heat insulating agent DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.), 100
A micron agricultural film was prepared and its transparency and heat retention were measured. Table 1 shows the heat retention index, total light transmittance, and haze value of this film.

Comparative Example 2 A hydrotalcite-based compound (aluminum magnesium composite hydroxide condensed silicate, trade name; Fujilein IR, manufactured by Fuji Chemical Industry Co., Ltd.) described in JP-A-8-217912 was used. A 100-micron agricultural film was prepared in the same manner as in Example 4 above.
The transparency and the heat retention effect were measured. Table 1 shows the heat retention index, total light transmittance, and haze value of this film.

[0059]

[Table 1]

Example 7 Ethylene-vinyl acetate copolymer (vinyl acetate content: 14% by weight, density: 0.92 g / cm
³ ) The compound 1 obtained in Example 1 was used as an infrared absorber.
0.0% by weight, hindered amine compound as light stabilizer (trade name: Tinuvin 622-LD, manufactured by Ciba-Gaiky)
0.5% by weight, antioxidant (trade name Irganox 10
10, manufactured by Ciba-Gaikey) 0.2% by weight, monoglycerin monostearate 1.0% by weight as an antifogging agent, 1.0% by weight of diglycerin distearate, Unidyne DS-401 (manufactured by Daikin Industries) as an antifog agent 0.1% by weight and 0.2% by weight of stearamide as a lubricant were added to make the total amount 100% by weight, and 13% using a Banbury mixer.
After kneading at 0 ° C. for 5 minutes, the mixture was granulated by a granulator to obtain a composition pellet. This is designated as resin composition A. Next, a composition pellet B was prepared in the same manner except that no infrared absorber was added.
I got The resin composition A is used as an intermediate layer, and the resin composition B is used as both outer layers.
Both outer layers (0.02 mm) were prepared.

Example 8 A film having a thickness of 0.1 mm was prepared in the same manner as in Example 7 except that the compound obtained in Example 2 was used as an infrared absorbent.

Example 9 A film having a thickness of 0.1 mm was prepared in the same manner as in Example 7 except that the compound obtained in Example 3 was used as an infrared absorbent.

Comparative Example 4 Commercial product DH as infrared absorber
A film having a film thickness of 0.1 mm was prepared in the same manner as in Example 7, except that T-4A (manufactured by Kyowa Chemical Industry Co., Ltd.) was used.

Comparative Example 5 JP-A No. 8-
Hydrotalcite-based compound (aluminum magnesium composite hydroxide condensed silicate [trade name; Fujilein IR, manufactured by Fuji Chemical Industry Co., Ltd.]]
A film having a film thickness of 0.1 mm was prepared in the same manner as in Example 7 except for using.

The films obtained in the above Examples 7 to 9 and Comparative Examples 4 to 5 were stretched for 8 months from April to November 1999, and exposed to weather (Nakashinagawa-gun, Toyama Prefecture) under weathering conditions. The properties, antifogging property and dewproofing property were evaluated according to the following methods.

As for the weather resistance, discoloration (yellowing, browning) and abnormal change of the film were visually confirmed. In addition, JIS K67
A tensile elongation test was carried out in accordance with No. 81, and a residual ratio (%) of elongation was obtained.

The anti-fogging property was visually confirmed when the entire film was formed into droplets.

The anti-dew property was checked by checking the entire film to see if there was any dew on the film.

As a result, all of the agricultural films obtained by the methods of Examples and Comparative Examples of the present invention had weather resistance (no discoloration or deterioration of the film was observed at all) and cloud-proofing property (drip formation). There was no problem with dew-proofing properties (no dew formation was observed at all). The following operation was performed to evaluate acid resistance (pesticide resistance).

The films obtained in Examples 7 to 9 and Comparative Examples 4 to 5 were allowed to stand in a sealed container in which sulfur was fumigated for about 1 hour. This sulfur fumigation film was produced from April 1999
Until November, they were exposed outdoors (Nakashinagawa-gun, Toyama Prefecture) for 8 months to observe the surface condition. The evaluation criteria were as follows, and the results after 8 months of outdoor exposure are shown in Table 2. A: Almost no change in appearance was observed. ；: Some changes in appearance such as coloring, cracking, and tearing are observed. Δ: Appearance changes such as coloring, cracks, tears, etc. are considerably recognized. ×: Cracks are observed over the entire surface.

[0071]

[Table 2]

[0072]

According to the present invention, the compound represented by the formula (I) [(M ²⁺ ) _a A
l ₂ (OH) _x ] (SO ₄ ) _y1 (CO ₃ ) _y2 (OH) _y3 · bH ₂ O (I) (where M ²⁺ is a divalent metal, a, b, x, y1, y2 , Y3
Is 2 ≦ a ≦ 8, 0 ≦ b ≦ 4, x = 2 (a + 2), y1
> 0, y2> 0, y3 ≧ 0, y1 + y2 + y3 / 2 = 1
An infrared absorbent characterized by containing a hydrotalcite-based compound represented by the formula (1) as an active ingredient, and an agricultural film formed by blending the resin with a resin and molding the same. The infrared absorber comprising the hydrotalcite-based compound of the present invention has a high infrared absorption ability, is excellent in dispersibility with a resin, and has a refractive index close to that of the resin, and has good acid resistance and good productivity. ,
It is easy to mix with resin, easy to process with resin, and when formed into a film, has excellent heat retention, transparency, and pesticide resistance, and is suitable as an agricultural film.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08J 5/18 CER C08J 5/18 CER C08K 5/103 C08K 5/103 5/3435 5/3435 9/04 9/04 C08L 101/00 C08L 101/00 // (C08L 101/00 (C08L 101/00 83:04) 83:04) F term (reference) 2B024 DA04 DB01 2B029 EB03 EC02 EC04 EC06 EC09 EC20 4F071 AA15 AB32 AC09 AC10 AC12 AE05 AE10 AE11 AF29 AH01 BC01 4F100 AC10A AH02A AH10A AJ11A AK68 AT00B BA02 GB01 JD10A JJ10 JN30A 4J002 AA011 BB031 BB051 BB061 BB071 BB081 BB151 BB231 BB241 BD041 BD051 BD061 BD081 BD101 CH052 CP033 CP093 DE286 EH008 EH048 EU077 EU087 FB086 FB266 FD016 FD047 FD203 FD206 FD208 FD312 FD318

Claims (8)

[Claims] 1. A formula (I) ^{_{[(M 2+) a Al 2 (}} OH) x ] _{(SO 4) y1 (CO 3} ) y2 (OH) y3 · bH 2 O (I) ( wherein, M ^{2 +} Is a divalent metal, a, b, x, y1, y2,
y3 is 2 ≦ a ≦ 8, 0 ≦ b ≦ 4, x = 2 (a + 2),
y1> 0, y2> 0, y3 ≧ 0, y1 + y2 + y3 / 2
= 1) is contained as an active ingredient. 2. The method of claim 1, wherein the hydrotalcite compound is a higher fatty acid, a higher fatty acid salt, an ester of a higher fatty alcohol and phosphoric acid, a wax, a nonionic surfactant, a cationic surfactant, An infrared absorber coated with one or more selected from coupling agents. 3. An agricultural film formed by mixing 1 to 50 parts by weight of the hydrotalcite-based compound according to claim 1 or 2 with respect to 100 parts by weight of the resin. 4. A resin is molded by mixing 1 to 50 parts by weight of the hydrotalcite compound according to claim 1 and 0.02 to 5 parts by weight of a hindered amine light stabilizer with respect to 100 parts by weight of the resin. An agricultural film characterized by the above-mentioned. 5. A resin obtained by mixing 1 to 50 parts by weight of the hydrotalcite-based compound according to claim 1 and 0.02 to 5 parts by weight of an antifoggant with respect to 100 parts by weight of a resin. Characteristic agricultural film. 6. A resin obtained by mixing 1 to 50 parts by weight of the hydrotalcite-based compound according to claim 1 and 0.02 to 5 parts by weight of an antifog with respect to 100 parts by weight of a resin. Characteristic agricultural film. 7. A resin composition containing the infrared absorbent according to claim 1 or 2. 8. A laminated film having at least one film using the resin composition containing the infrared absorbent according to claim 1 or 2.