JPH1084788A - Outdoor expansion film - Google Patents

Abstract

(57) [Summary] [Problem] To provide a film for outdoor expansion having transparency, excellent heat shielding properties and its sustainability. SOLUTION: An outdoor spreading film comprising a thermoplastic resin film provided on at least one surface thereof with a layer made of an acrylic resin having a thickness of 1 to 10 μm and containing inorganic fine particles having a heat ray shielding function and an ultraviolet absorber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outdoor stretching film used for covering horticulture facilities.
More specifically, the present invention relates to an outdoor stretchable film having transparency and excellent heat shielding properties and its durability.

[0002]

2. Description of the Related Art In conventional greenhouse horticulture, a house covering material generally used transmits visible light as much as possible for the purpose of improving heat insulation in winter and securing solar radiation necessary for photosynthesis. And transparent synthetic resin films such as polyvinyl chloride, polyolefin, and polyethylene terephthalate. These conventional synthetic resin films are intended to improve cultivation in winter.
From early summer to mid-summer to early autumn, the temperature inside the house becomes high, making facility horticulture difficult. Therefore, in the case of perennial flowers that need to go through the summer, use a shading net or a cold gauze as a lining or lining curtain to block solar radiation (including visible light) by about 30 to 80%.
It reduces the solar energy that penetrates into the house and suppresses the rise in temperature inside the house. In the case of flowers, although the cultivation is possible even with a small amount of required light, there is a problem that the plants are prostrate due to shading.

[0003] Cooling in a house is also performed as a countermeasure against high temperature in summer, but cooling by mist is apt to cause diseases due to wet plants, and the working environment deteriorates due to high humidity. Under the high temperature and high humidity environment like Japan, the effect is insufficient, and it is not widely used. On the other hand, cooling by a refrigerator is not often performed in a house where sunlight is poured, since the cooling efficiency is extremely low. On the other hand, regarding the cultivation of fruits and vegetables in summer,
In terms of crop physiology and quality, almost no shading is possible.In summer and southwest, greenhouse horticulture is not cultivated by greenhouse horticulture. In this case, the temperature inside the house becomes high, and the quality and the working environment are problematic. Therefore, visible light is transmitted as much as possible and heat rays (ie, near infrared rays)
There is a demand for a type of covering material that cuts as much as possible.

[0004] Therefore, an infrared-reflective material having a very thin metal layer deposited on the surface of a synthetic resin film (Japanese Patent Publication No. 59-13 / 1984).
No. 325), and an agricultural film using a hologram that reflects near-infrared rays and infrared rays in combination with a synthetic resin film (Japanese Patent Laid-Open Publication No. 7-274738), etc., but solar energy from the sun is visible. Since it has an energy amount of about 50% in the light region and about 50% in the near-infrared region and the infrared region, if visible light is blocked, the amount of transmitted solar radiation can be easily reduced, but the amount of visible light is insufficient. There is a problem. Therefore, it is desirable to positively absorb or reflect (block) light in the near infrared region in the solar energy, and kneading or applying a heat ray absorbent or a heat ray reflector to a synthetic resin film is performed. ing.

[0005]

As a method of kneading particles having a heat ray shielding function, for example, a heat ray reflecting agent such as tungsten hexachloride, cupric sulfide, an aminium-based near-infrared absorbing dye, a metal complex compound or the like is used. The blending of a heat ray absorbent is disclosed in Japanese Patent Publication No. 4-45546, Japanese Patent Publication No. 58-58.
JP-A-56533, JP-B-62-54143,
JP-A-50-51549, JP-B-54-2506
0, Japanese Patent Publication No. 1-114801,
It has been proposed in Japanese Patent Application Laid-Open Nos. 17306, 3-215561, 3-161644, 6-73197, 8-81567, and the like. Further, as a method of applying a heat ray reflecting agent or a heat ray absorbing agent, tin oxide fine particles are dispersed in a binder solution, the visible light transmittance obtained by forming a film on a transparent substrate is high,
In addition, a heat ray shielding film having excellent heat ray shielding properties (Japanese Unexamined Patent Publication No. 6-26
2717), a near-infrared absorbing film in which an organic near infrared absorbing layer made of an amino compound and an inorganic near infrared absorbing layer made of a solid solution of tin oxide and antimony oxide are laminated on a polyethylene terephthalate film (Japanese Patent Laid-Open No. 7-100996). Etc. have been proposed.

[0006] However, when exposed to the outdoors, both the heat ray absorbing agent and the reflecting agent deteriorate the heat ray shielding ability within several years, particularly within one year in the case of organic materials, and the effect as a countermeasure against high temperatures in a summer house is weakened. There was a problem coming.

[0007]

Under these circumstances, the present inventors have developed a film for shielding heat rays, which is a film for outdoor spreading, which transmits visible light and maintains the effect of heat ray shielding performance. We have studied hard to provide an improved outdoor film. As a result, the present inventors further include an ultraviolet absorber in the layer containing the inorganic fine particles having a heat ray shielding ability, whereby the heat ray shielding effect is maintained, and the effect of suppressing a temperature rise in the summer house is further improved. Was confirmed, and the present invention was completed.

[0008] The gist of the present invention is that a thermoplastic resin film is formed on at least one surface of a layer made of an acrylic resin having a thickness of 1 to 10 µm and containing inorganic fine particles having a heat ray shielding function and an ultraviolet absorber. Is provided in the film for outdoor expansion.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a heat ray is a wavelength 2
Means near infrared in the range of 00 to 2600 nm;
Shielding means reflection or absorption. Hereinafter, the present invention will be described in detail. The thermoplastic resin constituting the outdoor stretchable film of the present invention may be a resin generally used for film forming. Specifically, monomers such as vinyl chloride, ethylene, propylene, acrylates, methacrylates, and fluorinated ethylene may be used alone or as a mutual polymer thereof, or at least one of these monomers.
Copolymers of the species with other copolymerizable monomers (eg, vinyl acetate, vinylidene chloride, etc.), fluorine-containing resins, polyesters, polyamides, and the like, or blends of these polymers. Among these, weather resistance, light transmission,
From the viewpoints of economy, strength, etc., vinyl chloride resin (ie,
Preference is given to polyvinyl chloride and its copolymers containing at least 50% by weight of vinyl chloride) and ethylene-based resins (ie polyethylene and its copolymers containing at least 50% by weight of ethylene), most preferably polyethylene terephthalate and It is a fluororesin.

When polyethylene terephthalate is used, the film may be unstretched or biaxially stretched, but preferably biaxially stretched from the viewpoint of film strength. When stretching biaxially, lengthwise,
Those stretched 2.0 to 5.0 times in the horizontal direction are preferable. If the stretching ratio is less than 2.0 times, the strength of the product will not be sufficient, so that it is not preferable. If the stretching ratio exceeds 5.0 times, the strength of the product will be sufficient, but the manufacturing operation is difficult. Is not preferred. The stretching ratio is particularly preferably in the range of 2.5 to 4.0 times in both biaxial directions. The method for producing the biaxially stretched film is not particularly limited, and any conventionally known method such as stretching sequentially or simultaneously biaxially in the vertical and horizontal directions may be used.

The outdoor stretchable film according to the present invention preferably has a thickness of 0.01 to 0.3 mm. The thickness is 0.
If it is less than 01 mm, the strength of the product will not be sufficient, and if it exceeds 0.3 mm, the film will be hard,
It is not preferable because it becomes difficult to handle. These thermoplastic resins include, if necessary, known plasticizers, lubricants, heat stabilizers, metal organic phosphates, anti-fog agents, anti-fog agents, ultraviolet absorbers, Additives such as stabilizers, colorants, stabilizers, and antioxidants can be added in usual amounts.

Examples of the lubricant or heat stabilizer include chelators such as fatty acid-based lubricants, fatty acid amide-based lubricants, ester-based lubricants, polyethylene wax, liquid paraffin, and organic phosphite compounds which are generally used for films for outdoor stretching. Examples include phenols and β-diketone compounds. Specific examples include compounds described in JP-B-62-53543, column 7, lines 1 to 12.

[0013] Examples of the ultraviolet absorber include the following. 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate, ethyl-2-cyano-3,3'-, which is a cyanoacrylate-based ultraviolet absorber
Diphenyl acrylate and the like. 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, which is a benzophenone ultraviolet absorber; 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2-hydroxy-4-benzoyloxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5
-Sulfonebenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-5-chlorobenzophenone, bis- (2-methoxy-4 -Hydroxy-5-benzoylphenyl) methane and the like.

2- (2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5), which are benzotriazole ultraviolet absorbers
-Methylphenyl) -5-carboxylic acid butyl ester benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) -5,6-dichlorobenzotriazole, 2- (2'-hydroxy-5'-methyl Phenyl)
-5-ethylsulfonebenzotriazole, 2- (2 ′
-Hydroxy-5'-t-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5 '
-T-butylphenyl) benzotriazole, 2-
(2'-hydroxy-5'-aminophenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dimethylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-dimethyl Phenyl) -5-methoxybenzotriazole, 2- (2′-methyl-4′-
Hydroxyphenyl) benzotriazole, 2- (2 ′
-Stearyloxy-3 ', 5'-dimethylphenyl)
-5-methylbenzotriazole, 2- (2'-hydroxy-5-carboxylic acid phenyl) benzotriazole ethyl ester, 2- (2'-hydroxy-3'-methyl-5'-t-butylphenyl) benzotriazole, 2
-(2'-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2'
-Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'-methoxyphenyl) benzotriazole, 2- (2'-hydroxy-3 ' , 5'-Di-t-butylphenyl) -5-chlorobenzotriazole, 2-
(2′-hydroxy-5′-cyclohexylphenyl)
Benzotriazole, 2- (2′-hydroxy-4 ′,
5'-dimethylphenyl) -5-carboxylic acid benzotriazole butyl ester, 2- (2'-hydroxy-
3 ', 5'-dichlorophenyl) benzotriazole,
2- (2'-hydroxy-4 ', 5'-dichlorophenyl) benzotriazole, 2- (2'-hydroxy-
3 ', 5'-dimethylphenyl) -5-ethylsulfonebenzotriazole, 2- (2'-hydroxy-4'-
Octoxyphenyl) benzotriazole, 2- (2 ′
-Hydroxy-5'-methoxyphenyl) -5-methylbenzotriazole, 2- (2'-hydroxy-5'-
Methylphenyl) -5-carboxylate benzotriazole, 2- (2′-acetoxy-5′-methylphenyl) benzotriazole and the like.

Further, there may be mentioned a number and polymer of these cyanoacrylate, benzophenone and benzotriazole ultraviolet absorbers. These UV absorbers are 1
Species or two or more thereof may be used in combination, and the amount of use is 0.01 to 5 parts by weight, preferably 0.05 to 2 parts by weight, per 100 parts by weight of the thermoplastic resin.

In the outdoor stretchable film of the present invention, a layer made of an acrylic resin having a thickness of 1 to 10 μm containing inorganic fine particles having a heat ray shielding function and an ultraviolet absorber is formed on at least one surface of the film. In the present invention, the inorganic fine particles having a heat ray shielding ability may be any as long as they have an ability to absorb or reflect heat rays. Specific examples include oxides, carbides, borides, and the like of the metals in the periodic tables 4A, 5A, and 6A. Specific examples include titanium oxide, a solid solution of tin oxide and antimony oxide, cupric sulfide, and tungsten hexachloride. , Titanium mica (titanium oxide-coated mica), iron oxide-coated mica, basic lead carbonate, bismuth oxychloride, selenium oxide, zinc oxide and the like. Among them, inorganic oxides are preferred.

The average particle diameter of these inorganic fine particles is 1
Coarse particles exceeding 5 μm are not preferred because surface roughness is reduced, crater-like dents and projections are formed, resulting in poor appearance, irregular reflection on the surface is also remarkable, and visible light transmittance is reduced. Therefore, the average particle diameter of the inorganic fine particles is desirably 15 μm or less. In addition, the amount of the inorganic fine particles to be added should be adjusted so that the transmittance in the visible light region (typically, the transmittance at 555 nm) of the film after layer formation is 60% or more. In consideration of the above, it is more desirable to adjust the blending amount so that the visible light transmittance value is 80% or more. These inorganic fine particles,
One or several kinds may be used simultaneously. Further, an anthraquinone derivative, an organic compound such as a phthalocyanine compound, a naphthalocyanine compound, a squarylium compound, a thiourea compound, an immonium compound, or an acetylene compound, or a metal complex such as chromium, cobalt, or copper may be used in combination.

In the present invention, examples of the ultraviolet absorber incorporated in the acrylic resin layer include conventionally known ultraviolet absorbers such as salicylic acid compounds, cyanoacrylate compounds, benzophenone compounds and benzotriazole compounds. Among these, a benzophenone-based compound and / or a benzotriazole-based compound are preferable when evaluated from the viewpoint of solubility in an acrylic resin and application to a thermoplastic resin film for outdoor expansion.

Specifically, there may be mentioned the above-mentioned ultraviolet absorbers and their polymers and polymers. If the amount of the ultraviolet absorber mixed in the acrylic resin is too small, the object of the present invention is not achieved, and if it is too large, there is a problem of bleed out. A preferred amount is in the range of 10 to 25 parts by weight based on 100 parts by weight of the acrylic resin. Amount of UV absorber mixed in acrylic resin,
The thickness of the film formed on one surface of polyethylene terephthalate can be variously changed, but it is particularly preferable that the amount of the ultraviolet absorber per fixed area of the film is in the range of 150 to 1000 mg / m ² .

The acrylic resin of the present invention comprises, as a main component, an alkyl methacrylate monomer or an alkyl methacrylate monomer in the presence of a crosslinked acrylic ester-based elastic material, and is copolymerizable therewith. A graft copolymer obtained by polymerizing a mixture with a flexible vinyl monomer, wherein the crosslinked acrylate-based elastic material is 5 to 8
Those containing 0% by weight are preferred. A crosslinked acrylate monomer is a polymer obtained by polymerizing a crosslinkable monomer and an alkyl (meth) acrylate monomer, or a vinyl monomer copolymerizable therewith. is there.

The crosslinking monomer may be any one which is usually used as a polyfunctional compound. Specific examples thereof include ethylene glycol dimethacrylate, 1,3-
Butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, propylene glycol dimethacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, dipropylene glycol dimethacrylate, divinylbenzene, divinyl adipate, diallyl phthalate, diallyl maleate, Allyl acrylate, allyl methacrylate, triallyl cyanurate and the like,
These may be used in combination of two or more.

The (meth) acrylic acid alkyl ester monomer is an alkyl ester of acrylic acid or methacrylic acid, specifically, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, Isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, methyl methacrylate, ethyl methacrylate, methacrylic acid
n-propyl, isopropyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate,
Examples thereof include decyl methacrylate and the like. Generally, an alkyl acrylate having 1 to 20 carbon atoms in an alkyl group and / or an alkyl methacrylate having 1 to 20 carbon atoms in an alkyl group are used. You may mix and use.

The vinyl monomers copolymerizable with these (meth) acrylic acid alkyl ester monomers include methacrylic acid and alkyl esters of methacrylic acid (alkyl group having 1 to 12 carbon atoms), and dialkyl of itaconic acid. Examples thereof include esters (having 1 to 10 carbon atoms in the alkyl group), acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, styrene, alkyl-substituted styrene, α-methylstyrene, and the like. These monomers are used in an amount of 40% by weight or less, preferably 25% by weight or less.

The crosslinked acrylic ester-based elastic material is preferably produced by an emulsion polymerization method. The polymerization initiator that can be used at this time is a usual free radical generation initiator. Specific examples include inorganic peroxides such as potassium persulfate and ammonium persulfate; organic hydroperoxides such as cumene hydroperoxide, p-menthane hydroperoxide, ditertiary butyl hydroperoxide, and organic peroxides such as cumene peroxide. Examples include peroxides and azo-based initiators such as azobisisobutyronitrile.

Further, ordinary redox initiators obtained by combining these with reducing agents such as sodium sulfite, sodium acid sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, glucose, polyamine and hydroxyacetone ascorbate are also used. sell.
Usable emulsifiers include ordinary surfactants for emulsion polymerization. For example, anionic surfactants such as sodium, potassium and ammonium salts of alkyl sulfates having 8 to 20 carbon atoms and sodium and potassium salts of aliphatic carboxylic acids such as lauric acid, stearic acid and palmitic acid, and alkylphenols And non-ionic surfactants such as aliphatic alcohols and reaction products of polypropylene oxides and ethylene oxide. In some cases, two or more of these surfactants can be used in combination. Further, a surfactant such as a naphthalene formaldehyde condensed sulfonate may be added. If necessary, a cationic surfactant such as an alkylamine hydrochloride can be used.

As a method for producing a crosslinked acrylate-based elastic material by an emulsion polymerization method, the following method can be mentioned. (1) Emulsion polymerization by adding a small amount of a crosslinkable monomer to an alkyl acrylate monomer or a mixture of an alkyl acrylate monomer and a vinyl monomer copolymerizable therewith, How to manufacture by. (2) An alkyl acrylate monomer or a mixture of an alkyl acrylate monomer and a vinyl monomer copolymerizable therewith is further added to the polymer emulsion obtained by the method of (1). , An emulsion polymerization method. (3) The method of (2), wherein a small amount of a crosslinking agent is added to the monomer or the monomer mixture, and the mixture is produced by an emulsion polymerization method.

(4) First, an uncrosslinked polymer is prepared from an alkyl acrylate monomer or a mixture of an alkyl acrylate monomer and a vinyl monomer copolymerizable therewith by an emulsion polymerization method. To manufacture. Next, to this polymer were further added an alkyl acrylate monomer, or a mixture of an alkyl acrylate monomer and a vinyl monomer copolymerizable therewith, and a small amount of a crosslinkable monomer. , An emulsion polymerization method. (5) To one of the polymer emulsions obtained by the methods (1) to (4), an alkyl acrylate monomer or a vinyl monomer copolymerizable therewith is further added to form a crosslinkable monomer. A method in which an emulsion polymerization method is used without or without adding a body.

The average particle size of the crosslinked elastomer emulsion particles is adjusted by adjusting the amount of the surfactant and the amount of the aqueous medium to be used. Preferably, it is in the range of 0.30 μm. If the thickness is less than 0.05 μm, the mechanical strength of the acrylic resin used as the coating film is reduced,
If it exceeds μm, stress whitening becomes remarkable, which is not preferable.
Further, the crosslinked acrylate-based elastic body preferably has a gel content of 80% or more and a swelling degree of 15 or less as measured by the following method.

A predetermined amount W0 of the crosslinked elastic body was sampled, and the swelling weight W1 after immersing in methyl ethyl ketone for 48 hours at room temperature and the weight W2 after drying the sample with a reduced-pressure drier were measured and calculated by the following equation. I do. Gel content = (W2−W0) × 100 (%) Swelling degree = (W1−W2) / W0

The gel content and the degree of swelling are determined by adjusting the type and amount of the crosslinkable monomer, the temperature at which the elastomer is polymerized, the type and amount of the initiator, and the amount of the monomer constituting the elastomer. It is preferably adjusted as appropriate because it is affected by various polymerization conditions such as the method of adding the monomer and the presence or absence of a molecular weight regulator. When the gel content is less than 80%, the acrylic resin for forming a film obtained from the elastic body is completely dissolved in an organic solvent described later or excessively swells, and the elastic body particles are deformed. Not preferred. Regarding the degree of swelling, if it exceeds 15, stress whitening tends to occur, which is not preferable.

The monomer to be grafted onto the crosslinked acrylic ester-based elastic material is an alkyl methacrylate or an alkyl methacrylate as a main component, and is a mixture with a vinyl monomer copolymerizable therewith. . The alkyl methacrylate ester as a component to be grafted may be selected from the above-mentioned ones used in the production of an elastic body, and a vinyl monomer copolymerizable therewith is also used in the production of an elastic body. May be selected from those exemplified above. In this case, it is preferable to select the type and combination of monomers so that the glass transition temperature (Tg) of the polymer or copolymer obtained from the monomer component to be grafted is 50 ° C. or higher. If the Tg is less than 50 ° C., the thermoplastic resin film on which the acrylic resin film containing the graft polymer is formed has poor blocking resistance (is easily blocked), which is not preferable.

The graft polymerization reaction is preferably performed by an emulsion polymerization method, but may be performed by a solution polymerization method. When the emulsion polymerization method is used, for example, a monomer to be grafted is added to the emulsion of the crosslinked acrylate-based elastic material, and if necessary, an emulsifier, a polymerization initiator, a molecular weight regulator,
Water and the like can be added to select and carry out ordinary emulsion polymerization conditions. The ratio of the crosslinked elastic body and the monomer to be grafted when performing the graft polymerization reaction is 10 to 90 parts by weight of the crosslinked elastic body emulsion as a polymer solid content, and 90 to 10 parts by weight of the grafted monomer. It is better to choose from a range.

The graft polymer can be used as it is or as an acrylic resin for forming a film by blending a transparent hard thermoplastic resin having a Tg of 50 ° C. or higher and having compatibility with the graft polymer. In the latter, when blending, the proportion of the crosslinked elastic body contained in the acrylic resin is 5 to 80% by weight, preferably 10 to 50% by weight.
It is good to be in the range of weight%. When the proportion of the crosslinked elastic body is less than 5% by weight, the mechanical strength is inferior and 80% by weight.
When the value exceeds, the blocking resistance of the film having this as a coating film is deteriorated, which is not preferable.

The thickness of the acrylic resin layer containing the inorganic fine particles having a heat ray shielding function and the ultraviolet absorbent is 1 to 1
0 μm, and particularly preferably 1 to 5 μm. If the thickness is less than 1 μm, the object of the present invention is not achieved.

When the acrylic resin layer of the present invention is formed on the surface of a thermoplastic resin film, a composition comprising inorganic fine particles having a heat ray shielding function, an ultraviolet absorber and an acrylic resin may be used as a liquid dispersion medium, for example. A mixture of one or more organic solvents such as ketones such as methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene and xylene, and acetates such as methyl acetate and ethyl acetate. And used as a dispersion. This composition is applied to at least one surface of a thermoplastic resin film, and is dried by force or air, and the liquid dispersion medium is volatilized to form a coating film.

As a method of forcibly drying, hot air drying,
An infrared radiation method or the like can be adopted. The heating temperature when forcibly drying is determined by the applied composition.
To 250 ° C, preferably 70 to 200 ° C.

The coating method is a roll coating method,
Any known method such as dip coating, brush coating, spray coating, bar coating, and knife coating may be used.

When the adhesion between the film surface and the layer is not sufficient, the film surface is subjected to a plasma treatment or a corona discharge treatment before the layer is applied, or an appropriate anchor agent is applied. May be used to modify the film surface.

[0039]

The film for outdoor stretching according to the present invention is excellent in transparency and has a heat shielding effect in a summer agricultural house due to a synergistic effect of inorganic fine particles having a heat ray shielding ability and an ultraviolet absorber. It is highly useful as an outdoor stretch film because of its improved properties and excellent sustainability.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments, but the present invention is not limited to the following examples unless it exceeds the gist. Examples 1 to 10, Comparative Examples 1 to 4

(1) Preparation of base film (i) Polyethylene terephthalate Polyethylene terephthalate (o-chlorophenol used as a solvent has an intrinsic viscosity of 0.65 at 25 ° C.)
) Was blended with 100 parts by weight of the ultraviolet absorbers shown in Table 1 at the mixing ratios shown in the table as needed. After blending each composition with a super mixer for 10 minutes, the mixture was melt-extruded by a conventional method, and stretched at a stretching temperature of 65 in the machine direction.
° C, a draw ratio of 3.5 times, then a draw temperature of 65 in the transverse direction.
C., successively biaxially stretched at a draw ratio of 3.5 times to a thickness of 0.15
mm biaxially oriented film was produced. The density of this film was 1.37 g / cm ³ .

(Ii) Soft vinyl chloride resin film Per 100 parts by weight of polyvinyl chloride (degree of polymerization = 1300), 50 parts by weight of dioctyl phthalate, 5 parts by weight of tricresyl phosphate, and 2 parts by weight of epoxy resin ,
2 parts by weight of the Ba-Zn liquid stabilizer, 1 part by weight of the Ba-Zn powder stabilizer, and 1 part by weight of sorbitan monopalmitate.
5 parts by weight and 0.1 part by weight of the ultraviolet absorbent shown in Table 1 were weighed, and these were stirred and mixed by a super mixer for 10 minutes, and then kneaded on a roll heated to 165 ° C.
By L-type calender, width 100 cm, thickness 0.
A 15 mm transparent soft vinyl chloride resin film was produced.

(Iii) Fluororesin Film A discharge voltage of 120 V, a discharge current of 4.7 A and a line speed of 5 to 15 m were formed on one side of an ethylene-tetrafluoroethylene copolymer resin film (Tefzel AS, manufactured by DuPont, thickness: 64 μm). / Min was subjected to corona treatment.

(Iv) Polyolefin-based film 100
The extruder used was 30 mmφ (manufactured by Pla Giken Co., Ltd.) and two intermediate layers were 40 m.
As a mφ (manufactured by Pla Giken Co., Ltd.), a laminated film having a thickness of 0.15 mm having the following composition was produced at a molding temperature of 160 ° C., a blow ratio of 2.0 and a take-up speed of 5 m / min.

[Outer layer] Raw material resin (EVA (VA component: 5%)) 100 parts by weight Metal phosphate organic phosphate (zinc monooctadecyl phosphate) 0.5 Hindered amine (MARK LA-57) 0.5 UV absorption Agent 0.5 ソ ル sorbitan monostearate 0.5 〃

[Inner layer] Raw material resin (EVA (VA component: 15%)) 100 parts by weight Organic metal phosphate (monooctadecyl zinc phosphate) 0.5 Hindered amine (MARK LA-57) 0.5 UV absorption Agent 0.5 ソ ル sorbitan monostearate 0.5 ハ イ ド ロ hydrotalcite 15 〃

[0046]

[Table 1]

(2) Coating (i) Preparation of Acrylic Resin An acrylic resin solution for blending an ultraviolet absorber and inorganic fine particles having heat ray shielding ability was prepared as follows.

(A) Preparation of Acrylic Resin Solution a a-1 Production of Crosslinked Acrylate Elastomer 300 parts by weight of deionized water (hereinafter simply referred to as "parts" means "weight") in a polymerization vessel. Parts), 0.3 parts of potassium persulfate, 0.5 parts of disodium phosphate dodecahydrate,
After charging 0.3 parts of sodium hydrogen phosphate dihydrate and sufficiently purging with nitrogen, the internal temperature was raised to 70 ° C. The internal temperature was maintained at this temperature, and 19.8 g of styrene was added with stirring.
, 69.3 parts of butyl acrylate, 0.9 parts of allyl methacrylate, and 2.5 parts of sodium dioctylsulfosuccinate (emulsifier) were continuously added over 2 hours. Immediately after the addition was completed, 1.0 part of t-butylperoxy-2-ethylhexanoate and 2.2 parts of styrene were used.
Parts, butyl acrylate 7.7 parts, allyl acrylate 0.
One part mixture was added. 30 minutes after the addition was completed, the internal temperature was raised to 90 ° C.
The reaction was continued for an hour to obtain a crosslinked elastic emulsion. The average particle diameter of this crosslinked elastic body was 0.2 μm, the gel content was 97.1%, and the degree of swelling was 7.2.

A-2 Production of Graft Copolymer The crosslinked elastic emulsion 4 obtained in a-1 above was added to a polymerization vessel.
After the replacement with nitrogen and stirring, the internal temperature was raised to 80 ° C. While maintaining the internal temperature at this temperature, a solution prepared by dissolving 0.15 part of sodium formaldehyde sulfoxylate in 3.0 parts of deionized water was added with stirring, and then 30.0 parts of methyl methacrylate and n-octyl mercaptan were added. 0.03 parts, paramenthane peroxide (5
(0% solution) 0.15 parts of the mixture were added continuously over a period of 30 minutes. After completion of the addition, the polymerization reaction was continued for another 30 minutes to obtain a graft copolymer emulsion. The glass transition temperature (Tg) of the copolymer itself obtained from the grafted monomer component was 108 ° C. The obtained graft copolymer emulsion is salted out according to a conventional method,
The polymer was separated by filtration, washed with water, and dried to obtain a powder of the graft copolymer.

A-3 Preparation of Resin Solution a To 6.5 parts of the graft copolymer obtained in the above a-2 was added a methacrylic resin (a copolymer having a ratio of methyl methacrylate / ethyl methacrylate of 96/4). 13.5 parts of beads were mixed, and this mixture was placed in a mixed solvent consisting of 64 parts of methyl ethyl ketone and 16 parts of toluene and dissolved with stirring to prepare an acrylic resin solution a having a solid content of 20% by weight. .

(B) Preparation of Acrylic Resin Solution b b-1 Preparation of Crosslinked Acrylate Elastomer In a polymerization vessel, 250 parts of deionized water, 2.9 parts of sodium dioctylsulfosuccinate, and sodium formaldehyde sulfoxylate 0.05 part was charged and sufficiently replaced with nitrogen. While stirring the contents of the polymerization vessel, 1.6 parts of methyl methacrylate, 8.0 parts of butyl acrylate,
0.4 part of 3-butylene methacrylate, 0.1 part of allyl methacrylate, cumene hydroperoxide 0.1 part.
A mixture consisting of 04 parts was charged. 70 ℃ inside the polymerization can
, And the reaction was continued at this temperature for 60 minutes. Subsequently, 1.5 parts of methyl methacrylate, 22.5 parts of butyl acrylate, 1.0 part of 1,3-butylene methacrylate, 0.25 part of allyl methacrylate and a mixture of these monomers were added to the polymerization vessel. A mixture of 0.05% by weight of cumene hypoperoxide was added over 60 minutes. The average particle diameter of the obtained crosslinked elastic body is 0.12 μm, the gel content is 90%, and the swelling degree is 10%.
Met.

B-2 Production of Graft Copolymer A solution prepared by dissolving 0.01 part of sodium formaldehyde sulfoxylate in 3 parts of ionic water was added to a polymerization vessel containing the crosslinked elastic emulsion obtained in b-2 above. Then, 5 parts of methyl methacrylate, 5 parts of butyl acrylate, 0.1 part of allyl acrylate and 0.0
The mixture to which 3% by weight of cumene hydroperoxide was added was added continuously over 30 minutes. After completion of the addition, the polymerization reaction was continued for another 30 minutes.

A solution prepared by dissolving 0.05 part of sodium formaldehyde sulfoxylate in 3 parts of ionic water was added to the polymerization vessel, and the temperature was raised to 80 ° C. to obtain 52.25 parts of methyl methacrylate and 2 parts of butyl acrylate. .75 parts, paramenthane hydroperoxide (50% solution) 0.13
Parts of the mixture were added over 30 minutes. After the completion of the addition, the polymerization reaction was further continued at 80 ° C. for 30 minutes to obtain a graft copolymer emulsion. The glass transition temperature (Tg) of the copolymer itself obtained from the monomer component grafted on the outermost layer was 103 ° C. The obtained graft copolymer emulsion was salted out according to a conventional method, and the polymer was separated by filtration, washed with water, and dried to obtain a graft copolymer powder.

B-3 Preparation of Resin Solution b 20 parts of the graft copolymer obtained in b-2 above was placed in a mixed solvent consisting of 64 parts of methyl ethyl ketone and 16 parts of toluene, and stirred to obtain a solid content of 20% by weight. Was prepared.

(Ii) Formation of Coating Containing Ultraviolet Absorber and Inorganic Fine Particles The acrylic resin solution prepared according to the method described in the above (i) has an ultraviolet absorber of the type shown in Table 2 and a heat ray shielding function. The inorganic fine particles were added at the ratios shown in the table (meaning the ratios to the resin solids).

(3) Formation of Acrylic Resin Layer On one surface of each film obtained in (1) (in the case of a fluorine film, on the surface-treated surface), various coating film compositions obtained in (2) At a temperature of 140 ° C.
For 1 minute to disperse the solvent.

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[Table 2]

(4) Evaluation Various properties of each film obtained in (3) were evaluated by the methods described below, and the results are shown in Table 3. (I) Visible light transmittance Total light transmittance at 555 nm was measured using a self-recording spectrophotometer (Hitachi 330 type) using a 60φ integrating sphere. (Ii) Heat ray cutoff ratio Using a self-recording spectrophotometer (Hitachi 330 type), using a 60φ integrating sphere, measure the total light transmittance at 200 to 2600 nm, and obtain the wavelength dependence data of solar radiation energy from the sun. And the ratio of the solar energy blocked by the substrate to the solar energy directly received without the substrate.

(Iii) Ground Temperature and Air Temperature in the House A sealed pipe house (width 5 m × depth 10 m) was stretched with the surface on which the films were provided inside the house, and the daytime soil temperature and air temperature in summer were measured. The soil temperature was measured by putting sand in the center of the house, blocking the surroundings with a board, setting a thermocouple at a position of 5 cm in depth, and measuring the value at 14:00 when the weather was fine was shown as a value relative to the external value. . (July to 8 of 1991 to 8
(Mon, conducted at a test farm in Mie Prefecture)

(Iv) Summer cultivation Roof type house (frontage 9 m, depth 20 m, tower height 2.5
m, roof gradient 30 °) with each film layered on the inside of the house. From 1991 to 8 for each house
Tomatoes (variety Momotaro) were planted in early to middle May during the six seasons of the year, and harvested from late June to November. The tomatoes in each house were observed from flowering to fruit set to evaluate the persistence of the effect. The evaluation results were as follows.

5 points: a large number of flowers and very good fruit set 4 points: a normal number of flowers and good fruit set 3 points: a normal number of flowers and slightly dropped fruit 2 points: One with a small number of flowers and many fruit droppings: One that has skipped flowers (no flowering)

(V) Persistence of heat ray shielding effect The heat ray shielding effect after the use of the expansion was compared with that of the initial stage (first year) and evaluated according to the following criteria. 5 points: Maintains almost the initial effect. 4 points: Slightly inferior effect, but good cultivation. 3 points: Slightly inferior effect, slightly affects cultivation. 2: Slight heat ray shielding effect remains. But no effect on summer cultivation 1 point: almost no effect

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[Table 3]

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 27/20 B32B 27/20 Z 27/30 27/30 A

Claims (5)

[Claims] 1. A film for outdoor stretching comprising a thermoplastic resin film provided on at least one side with a layer of an acrylic resin having a thickness of 1 to 10 μm containing inorganic fine particles having a heat ray shielding property and an ultraviolet absorber. 2. The film for outdoor stretching according to claim 1, wherein the inorganic fine particles are an inorganic oxide having an average particle size of 15 μm or less. 3. The straight light transmittance at 555 nm is 60%.
The film for outdoor stretching according to claim 1 or 2, which is the above. 4. The ultraviolet absorber is a benzophenone compound and / or a benzotriazole compound,
Outdoor stretched film according to any one of the paragraphs to the amount of claims 1 ranges 150~1000mg per film 1 m ² 3. 5. An acrylic resin comprising a methacrylic acid alkyl ester monomer or a methacrylic acid alkyl ester as a main component in the presence of a crosslinked acrylate-based elastic material, and a vinyl monomer copolymerizable therewith. 5. The film for outdoor stretching according to claim 1, which is a graft copolymer obtained by polymerizing a mixture of the above.