JPH11179869A - Polycarbonate film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycarbonate resin film having an excellent chemical resistance, stain resistance, surface hardness, weather resistance and the like. SOLUTION: In the fluororesin-coated polycarbonate film comprising a polycarbonate film having a mean transmittance of 60% or less for an ultraviolet ray of a wave range of 280 to 320 nm and of a mean transmittance of 70% or less for a visible light ray of 400 to 700 nm, and a fluororesin film layer covering one surface of the polycarbonate film; the other surface of the polycarbonate film is further covered with a polyvinyl alcohol film layer having a saponification degree of 85 mol.% or more and a polymerization degree of 900 or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polycarbonate film, and more particularly, to a fluororesin-coated polycarbonate film.

[0002]

2. Description of the Related Art Conventionally, polycarbonate resins have been used for automobiles such as lamp lenses, tail lamp cases, radiator grilles, front grilles, etc .;
Electronic equipment such as IC trays, liquid crystal panels and relay parts;
Medical security applications such as artificial dialysis machines and artificial lungs; Optical-related applications such as compact discs and optical fibers; Food packaging applications such as curry roux, cheese, baby bottles and confectionery; Arcades, indoor pools, garage roofing materials, ski goggles It is used in a wide range of fields such as sheet and plate applications.

[0003] However, polycarbonate resin is
Since the basic skeleton is polyester, it is decomposed by basic chemicals such as caustic soda, caustic potash, salad powder, aqueous ammonia and calcium hydroxide, which hydrolyze ester bonds, and aromatic hydrocarbons such as benzene and toluene; acetone , Methyl isobutyl ketone (MIBK),
Ketones such as ethyl ether, ethylenediamine, methyl acetate and ethyl acetate, ethers, amines and ester hydrocarbons; chlorinated hydrocarbons such as methylene chloride and carbon tetrachloride;
By contacting with organic compounds such as ethyl cellosolve, lacquer thinner, thinners such as turpentine oil,
There is a problem that it cannot be used for applications that require chemical resistance because it causes craze or dissolves.

Further, since the surface is contaminated with magic ink, lipstick, diesel engine exhaust gas, factory soot, etc., its use in applications that require stain resistance is also limited.

Further, since the surface hardness is not high, dust,
Since many scratches are generated on the surface by the cleaning brush and the like and the surface is whitened, use in application fields requiring surface hardness is also restricted.

In addition, polycarbonate resin is decomposed and degraded by irradiation with sunlight for one to two years, the molecular weight is reduced, yellowing occurs, and the mechanical strength is extremely reduced.
There is a problem that it can hardly be used for outdoor applications where weather resistance is required, especially for outdoor thin films having a small film thickness.

[0007]

SUMMARY OF THE INVENTION The main object of the present invention is to provide a polycarbonate resin film which is improved in the above-mentioned problems of the polycarbonate resin and which is excellent in chemical resistance, stain resistance, surface hardness, weather resistance and the like. It is to provide.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a method for producing an ultraviolet light having an average transmittance of 75% or less for ultraviolet rays having a wavelength of 320 nm or less and a wavelength of 400% or less.
An object of the present invention is to provide a fluororesin-coated polycarbonate film comprising a polycarbonate film having an average transmittance of visible light of up to 700 nm of 70% or more and a fluororesin film layer adhered on one surface thereof.

Hereinafter, the film of the present invention will be described in more detail.

[0010] Polycarbonate (hereinafter sometimes referred to as "PC") used for the base film in the present invention.
Is not particularly limited, but is mainly a straight-chain polycarbonate or a copolymerized polycarbonate having a bisphenol skeleton, such as a 4,4'-dihydroxydiphenylalkane or a halogen-substituted product thereof, by the phosgene method or Those obtained by a transesterification method are preferred.

The above 4,4'-dihydroxydiphenylalkanes and their halogen-substituted products include, for example, 4,4'-dihydroxydiphenylmethane, 4,4'-
Dihydroxydiphenylethane, 4,4'-dihydroxydiphenylbutane, 4,4'-dihydroxydiphenyl-2,2-propane, 3,3'-dibromo-4,4 '
-Dihydroxydiphenyl-2,2-propane, 3,
3'-dichloro-4,4'-dihydroxydiphenyl-
2,2-propane, 3,3 ', 5,5'-tetrabromo-4,4'-dihydroxydiphenyl-2,2-propane and the like, among which 4,4'-dihydroxydiphenyl-2,2- Propane is preferred.

The polycarbonate may be used alone,
Further, for example, styrene-based resin, acrylonitrile-butadiene-styrenes copolymer (ABS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytetrafluoroethylene (PTFE)
A resin blended with such a resin can also be used. The PC film used as the base in the present invention is 2
The average transmittance of ultraviolet light in the wavelength range of 80 to 320 nm is 60.
%, Preferably 40% or less, more preferably 20% or less.
% Or less (PC films are generally 280 nm
UV light of the following wavelengths is not substantially transmitted) and 40
The average transmittance of visible light in the wavelength range of 0 to 700 nm is 70.
% Or more, preferably 80% or more, more preferably 85%
The above is a transparent film.

[0013] The substrate PC film used in the present invention further has an average transmittance of near-ultraviolet rays in a wavelength range of 320 to 400 nm of 80% or less, preferably 50%.
It is more preferably 30% or less, and when the coated PC film of the present invention is used as an agricultural coating material, the average transmittance of ultraviolet rays in the wavelength region of 320 to 380 nm is particularly 80%. Or less, preferably 65% or less, more preferably 40% or less, and it is desirable that the average transmittance of ultraviolet rays in a wavelength range of 380 to 400 nm is 50% or more, preferably 70% or more.

Therefore, in the present invention, the substrate PC
In order for the film to exhibit the above-mentioned light transmission characteristics, the above-mentioned PC is generally blended with an ultraviolet absorber in an amount so as to exhibit the above-mentioned light transmission characteristics before being formed into a film. Thereby, excellent weather resistance can be imparted to the base PC film.

The type of the ultraviolet absorber used here is not particularly limited as long as it can be mixed homogeneously with PC, and may be organic or inorganic, or both. Mixed systems can also be used.

As the organic ultraviolet absorber, for example,
The following are mentioned.

Hydroquinone- Hydroquinone, hydroquinone disalicylate and the like.

Salicylic acid phenyl salicylate,
Pellaoctylphenyl salicylate and the like.

Benzophenone- 2-hydroxy-4
-Methoxybenzophenone, 2-hydroxy-4-n-
Octoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-
4,4'-dimethoxybenzophenone, 2-hydroxy-4-benzoyloxybenzophenone, 2,2'-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfonebenzophenone, 2,
2 ', 4,4'-tetrahydroxybenzophenone,
2,2'-hydroxy-4,4'-dimethoxy-5-sodium sulfobenzophenone, 4-dodecyloxy-
2-hydroxybenzophenone, 2-hydroxy-5
-Chlorobenzophenone and the like.

Benzotriazole type 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl)
-5-carboxylic acid butyl ester benzotriazole,
2- (2'-hydroxy-5'-methylphenyl)-
5,6-dichlorobenzotriazole, 2-hydroxy-5'-methylphenyl) -5-ethylsulfonebenzotriazole, 2- (2'-hydroxy-5'-tert-butylphenyl) -5-chlorobenzotriazole, 2-
(2'-hydroxy-5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-5'-aminophenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dimethylphenyl ) Benzotriazole, 2- (2'-hydroxy-3 ', 5'-dimethylphenyl) -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'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-
3 ', 5'-ditert-butylphenyl) -5-chloro-benzotriazole, 2- (2'-hydroxy-5'-methoxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-phenylphenyl ) -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'-dichloro) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dimethylphenyl) -5-ethylsulfonebenzotriazole, 2- (2'-hydroxy-5'-phenylphenyl) benzotriazole, 2
-(2'-hydroxy-4'-octoxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-methoxyphenyl) -5-methylbenzotriazole,
-(2'-hydroxy-5'-methylphenyl) -5
Carboxylic acid ester benzotriazole, 2- (2'-
Acetoxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-ditert-butylphenyl) -5-chlorobenzotriazole and the like.

Triazines : 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-methyloxy-phenol, 2- (4,6-diphenyl-1,
3,5-triazin-2-yl) -5-propyloxy-phenol, 2- (4,6-diphenyl-1,3,5
-Triazin-2-yl) -5-t-butyloxy-phenol, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-pentyloxy-phenol, 2- (4 6-diphenyl-1,3,5-triazin-2-yl) -5-hexyloxy-phenol, 2
-(4,6-diphenyl-1,3,5-triazine-2
-Yl) -5-octyloxy-phenol, 2-
(4,6-diphenyl-1,3,5-triazine-2-
Yl) -5-nonyloxy-phenol and the like.

Among these ultraviolet absorbers, benzophenone-based, benzotriazole-based and triazine-based ones are preferred, and triazine-based ones are particularly preferred. Above all, in the benzophenone system, 2,3'-dihydroxy-4,4-dimethoxybenzophenone, 2,2 '
Dihydroxy-4-methoxybenzophenone and 2,
2 ', 4', 4'-Tetrahydroxybenzophenone:
For benzotriazole, 2- (2'-hydroxy-
5'-methylphenyl) benzotriazole, 2-
(2'-hydroxy-5'-methylphenyl) -5,6
-Dichlorobenzotriazole, 2- (2-hydroxy-5'-tert-butylphenyl) benzotriazole,
-(2'-hydroxy-3'-methyl-5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-ditert-butylphenyl) -5-chloro-benzotriazole , 2- (2'-hydroxy-
5'-phenylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-ditert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'- Octoxyphenyl) benzotriazole and the like are preferred.

In the triazine series, the following formula

[0024]

Embedded image

Wherein R ₁ is C ₁ -C ₂₀ , preferably C ₃ -C
₁₀ , more preferably a C ₄ -C ₈ alkyl group or an aryl group, especially a phenyl group, wherein R ₂ and R ₃ are each a hydrogen atom or a C ₁ -C ₅ alkyl group or an aryl group,
In particular, a compound represented by, which represents a phenyl group, is preferable. Among them, the compound of the above formula (I) wherein R ₁ is a hexyl group and R ₂ and R ₃ are hydrogen atoms is particularly preferable.

The inorganic UV absorber includes, for example, the following simple metals and metal compounds.

For example, it is possible to use simple metals such as titanium, zirconium, magnesium, calcium, barium, lanthanum, zinc, aluminum, tin, antimony and their oxides, composite oxides, sulfides, carbonates, etc. Specifically, for example, titanium oxide (TiO ₂ ), zinc oxide (ZnO), mica, alumina (Al ₂ O ₃ ), iron oxide (Fe ₂ O ₃ ), cerium oxide (CeO ₂ ), barium oxide (BaO) ), Antimony oxide (Sb ₂ O ₃ ), nickel oxide (NiO), chromium oxide (Cr ₂ O ₃ ), zirconium oxide (ZrO ₂ ), calcium oxide (CaO), tin oxide (SnO ₂ ), and mixtures thereof. Is mentioned.
Among them, TiO ₂ , ZnO, CeO ₂ and Fe ₂ O ₃ are preferable, and CeO ₂ is particularly preferably used.

The particle size of the metal simple substance and the metal compound is as follows:
Although not specifically defined, generally, the average particle size is 1,500 to 1 nm, preferably 500 to 5 nm,
More preferably 100 to 10 nm, particularly preferably 5 to 10 nm
In the case of metal compounds having a surface activity in the range of 0 to 20 nm and having remarkable surface activity such as TiO ₂ and CeO ₂ , the specific surface area is 100 m ² / gr or less, preferably 30 m ² / gr or less, more preferably. Is preferably 5 m ² / gr or less, particularly preferably 1 m ² / gr or less. Here, the “specific surface area” means the surface area of 1 g of the metal compound, and its measuring method is BET (Brunauer-Emmett-BET) which is one of the conventionally used gas adsorption methods.
Teller) method.

CeO ₂ having the above specific surface area can be obtained, for example, by subjecting cerium carbonate, oxalate, nitrate, hydrochloride, etc. obtained in the production process to 500 ° C. in an oxygen atmosphere.
Above, preferably at least 1,000 ° C., more preferably at least 1,300 ° C., and particularly preferably at 1,500 ° C., it can be produced by firing.

The ultraviolet absorbent as described above is used to form the PC
The film may be blended in such an amount as to exhibit the above-mentioned ultraviolet shielding properties, and the blending amount may vary widely depending on the type of the ultraviolet adsorbent, the type of the synthetic resin used, the thickness of the film or plate, and the like. Can be changed, but usually 0.0
It can be in the range of 01 to 10 PHR, preferably 0.01 to 3 PHR, more preferably 0.1 to 1.5 PHR.

PC is blended with the above-mentioned ultraviolet absorbent,
If necessary, an anti-blocking agent, a coloring agent,
After blending additives such as antifogging agents and antistatic agents, for example,
It is formed into a film by a hot melt extrusion method, a solvent casting method or the like.

The thickness of the film at this time is not strictly limited, and can be changed according to the use of the film, but is generally 5 to 1,000 μm, preferably 50 to 500 μm, and more preferably 50 to 500 μm. Preferably 100 to 30
A range of 0 μm is suitable.

The present invention relates to a PC molded as described above.
It has a novel feature in that a fluororesin film layer is applied to one surface of the film, and as a result, a fluororesin-coated PC excellent in chemical resistance, stain resistance, surface hardness, etc.
It succeeded in providing a film.

The fluororesin used in the present invention is:
A resin containing fluorine in the molecular structure of the resin,
For example, (co) polymers containing one component of a fluorine-containing ethylene monomer such as ethylene tetrafluoride, ethylene trifluoride, ethylene trifluoride chloride, ethylene difluoride, and ethylene monofluoride are included. Preferred is ethylene fluoride (co) polymer (PVDF).

Specific examples of the (co) polymer of ethylene tetrafluoride include polytetrafluoroethylene (PTFE), ethylene tetrafluoride / perfluoroalkoxyethylene copolymer (PFA), and ethylene tetrafluoride / 6 Propylene fluoride /
Perfluoroalkoxyethylene copolymer (EPE),
Ethylene tetrafluoride / propylene hexafluoride copolymer (FE
P), ethylene tetrafluoride / ethylene copolymer (ETF
E) and the like, and ETFE is particularly preferred.

The (co) polymer of ethylene trifluoride or ethylene trifluoride chloride includes, for example, poly (ethylene trifluoride) (CTFE),
Examples of the ethylene copolymer (ECTFE) and the like, and examples of the (co) copolymer of ethylene monofluoride include polyvinyl fluoride (PVF).

On the other hand, a (co) copolymer (PVDF) of ethylene difluoride, which is particularly preferably used as a fluororesin for coating a PC film, includes a homopolymer of vinylidene fluoride (VDF) and a fluoropolymer of vinylidene fluoride (VDF). Copolymers with at least one other fluoroolefin copolymerizable with vinylidene are included. As other copolymerizable fluoroolefins, ethylene tetrafluoride (TFE) and propylene hexafluoride (HFP) are particularly preferable.

As a preferred specific example of such a copolymer, the weight ratio of VDF / TFE is (95-55) / (5-
45), a VDF-TFE copolymer, preferably in the range of (80-60) / (20-40), VDF / TFE
/ HFP weight ratio is (90-50) / (5-40) /
(5-30), preferably (80-50) / (15-3)
5) / (5 to 25), more preferably (75 to 55)
/ (20 to 35) / (10 to 20), and more preferably a VDF-TFE-HFP copolymer in the range of (60 to 70) / (25 to 30) / (10 to 15). .

[0039] Such a PVDF copolymer is a PVDF copolymer.
Compared to homopolymers, they have the advantage of being rich in flexibility, having a low melting point, and being excellent in solubility in organic solvents, and can be easily applied as a thin film layer to a PC film.

As the PVDF, for example, KYNAR 7201, K from LF Atochem Japan K.K.
The thing marketed under the brand name of YNAR 9301 can be used.

PV which can be used preferably in the present invention
The specific gravity and the melting point of the DF are not strictly limited, and can be appropriately selected by means for attaching to the PC film surface. For example, in the case of applying by the heat melting method (method a), P having a specific gravity (measurement method: conforming to ISO 1183, the same applies hereinafter) in the range of 1.77 to 1.80.
In the case of coating by VDF and an organic solvent method (method b), PVDF having a specific gravity in the range of 1.85 to 2.00 is preferably used. The melting point of PVDF (measuring method: ISO 3146, the same applies hereinafter) is preferably in the range of 130 to 170 ° C. in the method a, and in the range of 80 to 130 ° C. in the method b. it can.

Further, if necessary, another resin may be added to the PVDF in order to improve the adhesion to the PC film. Examples of other resins that can be blended include (meth) acrylic acid ester (co) copolymers, styrene-based resins, cellulose-based resins, and other fluorine-based resins. A (co) polymer is preferably used, and a methyl methacrylate polymer is particularly preferred. The mixing ratio (weight) of these resins to PVDF can be generally 50% or less of the total resin amount, preferably 10 to 40.

The thickness of the fluororesin film layer to be adhered to the PC film can be appropriately selected according to the use of the film and the like. In general, the thickness is desirably smaller than the thickness of the PC film. 0.05-100
μm, preferably 0.1 to 10 μm, more preferably 1 to 5 μm.

In the present invention, the method of applying the fluororesin film to the PC film is not particularly limited, and the application of the final film and the type and thickness of the fluororesin film to be applied are taken into consideration. It can be selected as appropriate. For example, when a relatively thin film layer having a thickness of 5 μm or less is to be applied, it is preferable to directly coat a fluororesin solution dissolved in an organic solvent on the PC film. When a thick fluororesin film layer is applied, it is preferable to prepare a fluororesin film in advance by a hot-melt extrusion method or the like and laminate this to a PC film.

The organic solvent for dissolving the fluororesin in the former direct coating method is not particularly limited, and any solvent can be used as long as it is a solvent that dissolves the fluororesin. When the fluororesin is PVDF, examples of the solvent include amine solvents such as hexamethylene diamine and propylamine; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and methyl isoamyl ketone; dimethylformamide, diacetone acrylamide, Amide solvents such as dimethylacetamide; ester solvents such as carbitol acetate, ethyl acetate, butyl acetate, and methyl cellosolve acetate; ether solvents such as tetrahydrofuran; cyclic hydrocarbon solvents such as cyclohexanone and toluene; Examples thereof include solvents such as nitropropane, diacetone alcohol, and tributyl phosphate, and these solvents are used alone or in combination. When the solvents are used in combination, for example, butyl acetate / methyl isobutyl ketone (MIBK), butyl acetate / MIBK / toluene, MI
BK / cyclohexane / diacetone acrylamide, toluene / diacetone alcohol / carbitol acetate and the like. The mixing ratio of these solvent systems is not particularly limited. For example, the weight ratio of butyl acetate / MIBK /
30-75 / 15-40 / 10-3 in toluene system
0, preferably 40 to 55/25 to 35/15 to 25, and 30 to 75/10 to 40/1 in the MIBK / cyclohexane / diacetone acrylamide system.
5 to 40, preferably 50 to 60/15 to 25/20 to
30, and for the toluene / diacetone alcohol / carbitol acetate system, 1-15 /
5 to 25/50 to 99, preferably 3 to 10/5 to 15
/ 75 to 90.

Since all of the above solvents are good solvents for PC, when a PVDF solution dissolved in the above organic solvent is directly coated on a PC film, the PC is gradually eroded from the coated surface, and Thus, the film shape cannot be maintained. To prevent this, if you try to coat with a small amount of solvent and dry it in a short time, the film shape can be maintained, but cracks will occur on the film surface, the strength of the PC film will be significantly reduced, and the film will whiten The curl property becomes remarkable, and depending on the application, it may not be practically used.

The present inventors have conducted various studies to solve these problems. As a result, the solvent (system) for dissolving the fluororesin (hereinafter sometimes referred to as “solvent X”) is: It has been found that these problems can be solved at once by mixing a diluent in which PC is insoluble and has durability (hereinafter, this may be referred to as “diluent Y”).

When the diluent Y is mixed with the solvent X, the mixing ratio (weight) of the diluent Y [diluent Y / (solvent X + diluent Y) × 100] is generally 10% or more, preferably 2%.
0% or more, more preferably 30% or more. A suitable amount of the diluent Y varies depending on the type of the solvent X, the type and the concentration of the fluororesin, and the temperature of the solution, and it can be easily determined by those skilled in the art by conducting small-scale experiments. . If the amount of the diluent Y is too large, the fluororesin will not be dissolved. Therefore, the upper limit of the amount of the diluent Y is set by gradually adding the diluent Y to the solution of the fluororesin in the solvent X, It can be determined by the amount of the diluent Y at the time when the resin starts to precipitate.

Here, the type of the diluent Y is not particularly limited, but typical examples thereof include alcohols such as methyl alcohol, ethyl alcohol, butyl alcohol, and isopropyl alcohol; n-heptane And aliphatic hydrocarbons such as petroleum-based benzene, among which alcohols are preferably used, and isopropyl alcohol is particularly preferable.

The concentration of the fluororesin in the coating solution prepared using the above-mentioned solvent / diluent system is not particularly limited, and may vary over a wide range depending on the type of the fluororesin, its coating film thickness and the like. Although it can be varied, it is generally 5 to 40% by weight, preferably 10 to 30% by weight.
%, More preferably 15 to 20% by weight.

The above-mentioned fluororesin solution can be coated on the surface of the PC film by a method known per se, for example, a gravure roll method, a roller touch method, a bar coater method, a spray method, a dipping method, a brush coating method. Etc. can be coated by a normal application method,
Among them, the gravure roll method and the roller touch method are preferable.

The coating film can be dried by either a natural drying method or a forced drying method. Generally, a forced coating method such as a hot air drying method or an infrared irradiation method produces a uniform coating film. It is preferable in that it can be obtained. The drying temperature varies depending on the boiling point of the dispersion medium used and the like.
C., especially in the range of 50.degree.

On the other hand, when the fluororesin film layer is applied on the PC film by the above-mentioned laminating method, the method for producing the fluororesin film by the hot-melt extrusion method is not particularly limited. Can be used. For example, in the case of ETFE, a film can be formed at a resin temperature of about 320 ° C. by an extruder, and in the case of PVDF, a film can be formed at a resin temperature of about 250 ° C. The fluororesin film thus obtained is adhered to one surface of the PC film via an adhesive. At this time, the adhesive is desirably applied to the surface of the fluororesin film to be adhered to the PC film, and the surface to be adhered to the fluororesin film is subjected to a surface treatment as necessary to increase the adhesive strength with the PC film. Can be enhanced. As the surface treatment method, for example, corona discharge treatment, sputter etching treatment, sodium treatment,
Examples of the method include sandplast treatment.

In the corona discharge treatment, a discharge is caused between a needle electrode or a knife edge electrode and a counter electrode, a sample is put between the electrodes, and the treatment is carried out. On the film surface, aldehyde, acid, alcohol peroxide, ketone, ether, etc. This is a process for generating a functional group containing oxygen.

In the sputter etching process, a sample is put between electrodes performing low-pressure glow discharge, and a large number of fine projections are formed on the film by the impact of positive ions generated by the glow discharge.

In the sodium treatment, the film is immersed in a liquid ammonia solution of an alkali metal such as metallic sodium to eliminate the CF ₂ bond from the surface and to remove CH, CO
This is a process for generating a bond.

In the sand plast treatment, fine sand is sprayed on the film surface to form a large number of fine irregularities on the surface.

Among these surface activation treatments, from the viewpoints of adhesion to the coating, workability, safety, cost, and the like,
It is preferable to perform a corona discharge treatment.

In the case of laminating a fluororesin film on a PC film, an adhesive layer is provided in advance on the surface of the fluororesin film on the side to be laminated on the PC film, and the PC layer is formed via the adhesive layer by, for example, a dry lamination method. It is preferable to apply a fluororesin film to the film. This can prevent the PC film from being attacked by the solvent in the adhesive.

As the binder resin used for forming the above-mentioned adhesive layer, one having a good bonding force to both the fluororesin and the PC is preferable. For example, a binder resin such as (meth) acrylate (co) polymer Acrylic resins, vinyl resins such as vinyl acetate (co) polymers, rubbers such as neoprene rubber, cellulose resins, epoxy resins, urethane resins, etc., among which acrylic resins and vinyl resins are preferred is there.

These binder resins are applied to the surface of the fluororesin film in the form of a solution or dispersion in an organic solvent, and the coating film is dried to substantially completely remove the organic solvent. The organic solvent that can be used here can be selected according to the type of the resin to be dissolved or dispersed, for example, alcohol, ester, ketone, chlorinated hydrocarbon, aliphatic hydrocarbon, Solvents such as aromatic hydrocarbons and mixtures thereof can be used.

The application of the organic solvent solution of the binder resin can be performed by a method known per se, for example,
The coating can be performed by a usual coating method such as a gravure roll method, a roller touch method, a bar coater method, a spray method, a dipping method, and a brush coating method. Among them, the gravure roll method is preferably used.

The coating film can be dried by either a natural drying method or a forced drying method. In general, a uniform coating method such as a hot air drying method or an infrared irradiation method is used to form a uniform coating film. It is preferable in that it can be obtained. Although the drying temperature varies depending on the boiling point of the solvent used, it is usually 50 ° C to 140 ° C.
C., especially in the range of 60C to 90C.

The fluororesin film on which the adhesive layer has been formed is superposed on the PC film with the adhesive layer interposed therebetween, and then bonded to the PC film by a dry lamination method.

The lamination of the fluororesin film on the PC film is also carried out by extruding a molten thin film of the binder resin as described above between the PC film and the fluororesin film according to the hot-melt extrusion laminating method. be able to.

The film of the present invention thus obtained can be widely used as a single film or a composite adhered to the surface of another material. Fields used as a film alone include, for example, agricultural covering materials, outdoor covering materials such as simple warehouses; arcades, roofing materials, lighting materials such as glass substitute materials; goggles,
Protective facepieces such as helmet facepieces and work protection facepieces; display board fields such as nameplates, display boards, and signboards; and insect and bactericidal membrane fields such as lighting and illuminators used in factories, homes, and streets. In particular, it can be suitably used in the field of outdoor coating, particularly as an agricultural coating material.

The film of the present invention is harmful to animals and plants, particularly useful plants, and substantially emits ultraviolet light having a wavelength of 320 nm or less required for visualization of insect pests, sporulation of diseased filamentous fungi, and the like. Can be shielded,
For example, as an agricultural coating material, it can be advantageously used to protect animals and plants from the ultraviolet rays, to repel pests, to prevent the growth of filamentous fungi, and the like.

Further, since the surface of the film of the present invention is covered with a fluororesin film layer, it is possible to prevent the adhesion of dust and pollution by exhaust gas, soot, smoke of cigarettes, acid rain, etc. It can be used for a long time in the field of outdoor coating.

As described above, the film of the present invention has an ability to block ultraviolet rays, and has on its surface a fluororesin film layer having excellent chemical resistance, stain resistance, surface hardness and the like. Therefore, by forming a composite with other materials, the deterioration of other materials due to ultraviolet rays, the deterioration of printing ink, etc., of other materials whose surfaces are decorated by printing or the like can be suppressed. Can be protected for a long time from pollution by exhaust gas, soot, dust, tobacco smoke, acid rain and the like.

The composite comprising the film of the present invention and other materials includes, for example, in the field of composites with steel plates such as decorative steel plates, building interior and exterior wall materials, signboards, road signs, etc .; agricultural coating materials, aircraft interior walls Materials, vehicle interior materials, solar cells, solar water heaters, fresh water production equipment, sign materials, retroreflective sheets and other plastic composites; with inorganic materials such as shatterproof glass, ceramics, cement, and slate building materials The composite field and the like can be mentioned.

As described above, the film of the present invention shields ultraviolet rays harmful to useful plants, and is excellent in dustproofness, stain resistance, etc., and can be suitably used as an agricultural coating material. When the film of the present invention is spread as a covering material for agriculture in a greenhouse or the like, it is necessary to prevent the film from becoming cloudy (or from adhering water droplets) due to the moisture in the house and reducing the amount of transmitted sunlight. It is preferable that the surface of the film of the present invention on the side opposite to the side on which the fluororesin film layer is adhered be subjected to antifogging (flow droplet) treatment.

As one of such anti-fogging (flow droplet) treatments, the surface of the film of the present invention on the side opposite to the side on which the fluororesin film layer is adhered has a degree of saponification of 85 mol% or more, It is preferably at least 90 mol%, more preferably 97 mol%.
A polyvinyl alcohol film layer having a molar percentage of at least 99.5 mol% and a polymerization degree of at least 900, preferably at least 1,000, and more preferably at least 1,700 can be provided.

As the polyvinyl alcohol (hereinafter sometimes referred to as “PVA”) that can be used for the anti-fog treatment, a homopolymer, a copolymer with another monomer, or a blend with another polymer may be used. it can.

The PVA homopolymer has an excellent antifogging effect, but has a drawback in that it lacks water resistance and thus lacks long-term durability of the antifogging effect. Then, the present inventors searched for PVA excellent in long-term durability of the anti-fogging effect, and as a result, the following were found to be useful.

(A) blend of PVA homopolymer and α-olefin / maleic anhydride copolymer, (B) PVA
Modified PV in which silicon is introduced into the molecule of A homopolymer
A, (C) PVA homopolymer having 2 to 2 carbon atoms as a side chain
A modified PVA into which 10 hydroxyalkyl groups have been introduced,
(D) a modified PVA obtained by introducing a mercapto group into the terminal of a PVA homopolymer, and (E) a modified PVA obtained by copolymerization with ethylene.

Of these PVAs, modified PVAs (B), (C) and (E) are preferred, and modified PVAs (C) and (E) are particularly preferred.

The α-olefin / maleic anhydride copolymer used in the blend (A) includes, for example, ethylene, propylene, 1-butene, isobutene, 1-pentene, isoprene, 1-hexene, 2-methyl -1-
Pentene, 3-methyl-1-pentene, 4-methyl-1
-Copolymers of α-olefins such as pentene and styrene with maleic anhydride, among which copolymers of isobutene and maleic anhydride are particularly preferred. The copolymerization ratio of α-olefin to maleic anhydride in the copolymer is usually 10:90 to 90:10, preferably 30:70 to 7 by weight ratio of α-olefin to maleic anhydride.
0:30, and these copolymers have a P
Generally, 30 to 60 per 100 parts by weight of VA homopolymer
It can be blended within the range of 20 parts by weight, preferably 20 to 40 parts by weight.

In the modified PVA (B), P
Examples of the method of introducing silicon into the VA homopolymer include a method of introducing silicon into PVA or modified polyvinyl acetate containing a carboxyl group or a hydroxyl group by post-modification using a silylating agent; vinyl ester and silicon-containing olefin. And a method of saponifying a copolymer with an unsaturated monomer.

In the method of post-modifying PVA or modified polyvinyl acetate with a silylating agent, for example, an organic solvent which does not react with the silylating agent, such as benzene, toluene, xylene, hexane, heptane, ether or acetone, is used. The silylating agent is dissolved, and powder P
VA or the modified polyvinyl acetate is suspended under stirring,
The silicon-containing modified PVA is prepared by reacting the silylating agent with PVA or the modified polyvinyl acetate at room temperature or a temperature within the range of the boiling point of the silylating agent, or by further saponifying the vinyl acetate unit with an alkali catalyst or the like. Obtainable. Examples of the silylating agent used in such post-modification include organohalogen silanes such as trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, vinyltrichlorosilane, diphenyldichlorosilane and triethylfluorosilane; trimethylacetoxy Organosilicon esters such as silane and dimethyldiacetoxysilane; organoalkoxysilanes such as trimethylmethoxysilane and dimethyldimethoxysilane; organosilanols such as trimethylsilanol and diethylsilanediol; aminoalkylsilanes such as N-aminoethylaminopropyltrimethoxysilane An organosilicon isocyanate such as trimethylsilicone isocyanate; The introduction rate of the silylating agent, ie, the modification rate, can be arbitrarily adjusted depending on the amount of the silylating agent used and the reaction time. The polymerization degree and saponification degree of the obtained silicon-containing modified PVA can be arbitrarily adjusted by the polymerization degree of the PVA used, the saponification degree or the polymerization degree of the modified polyvinyl acetate and the saponification reaction.

In the method of saponifying a copolymer of a vinyl ester and a silicon-containing olefinically unsaturated monomer, for example, the vinyl ester and the silicon-containing olefinically unsaturated monomer are converted into a radical in an alcohol. Copolymerization using an initiator, followed by adding an alkali or acid catalyst to an alcohol solution of the copolymer to saponify the copolymer, thereby obtaining a silicon-containing modified PV.
A can be obtained. Examples of the vinyl ester used in such a method include vinyl acetate, vinyl propionate, and vinyl formate. Of these, vinyl acetate is preferable from the viewpoint of economy. On the other hand, as the silicon-containing olefinically unsaturated monomer used in such a method, a vinylsilane represented by the following formula (II) or a formula (I)
(Meth) acrylamide-alkylsilanes represented by I).

[0081]

Embedded image

In the formula, n is 0 to 4, m is 0 to 2, R ⁴ is hydrogen, halogen, a lower alkyl group, an allyl group or a lower alkyl group having an allyl group, and R ⁵ is an alkoxyl group. A group, an acyloxyl group (where the alkoxyl group or the acyloxyl group may have a substituent containing oxygen or nitrogen) or a hydroxyl group, R ⁶ represents hydrogen or a methyl group, and R ⁷ represents a lower alkyl group And R ⁸ represents an alkylene group or a divalent organic residue in which chain carbon atoms are connected to each other by oxygen or nitrogen.

The content of silicon in the modified PVA (B) (the amount of copolymerized units or monomer units post-modified with a silylating agent) is usually 0.01 to 10 mol%, preferably 0.1 to 5 mol%. Mol%.

Further, the modified PVA (C) can be prepared by reacting a vinyl ester such as vinyl acetate with a compound of the formula CH ₂ ＣＨCH—R ⁸
-OZ (where R ⁸ has 2 to 20 carbon atoms, preferably 2 to 2 carbon atoms)
And more preferably 3 to 10 alkylene groups, wherein Z represents a hydrogen atom or a hydroxyl-protecting group capable of leaving under saponification conditions, for example an acyl group such as formyl, acetyl, propionyl, etc.) Can be produced by saponifying a copolymer of Examples of the hydroxyl group-containing olefin include 3-buten-1-ol and 4-pentene-
1-ol, 5-hexen-1-ol, 7-octen-1-ol, 9-decene-1-ol, 11-dodecene-1-ol, 3-methyl-3-buten-1-ol and the like and the like A hydroxy protected form.

The content of these hydroxy group-containing olefin units in the above copolymer is usually 0.1 to 10%.
It can be 25 mol%, preferably 0.3 to 15 mol%.

The modified PVA (D) can be obtained, for example, by saponifying a polyvinyl ester obtained by polymerizing a vinyl ester such as vinyl acetate in the presence of thiolic acid. The thiolic acid used here is a COSH-type organic acid, and examples thereof include thiolacetic acid, thiolpropionic acid, thiolbutyric acid, and thiolvaleric acid. Among them, thiolacetic acid is preferable because it has good decomposability. The modified PVA (E) can be obtained, for example, by saponifying a copolymer composed of ethylene and vinyl acetate. The content of ethylene units in the copolymer can be appropriately determined according to the purpose of use,
Usually, 1 to 45 mol%, preferably 15 to 40 mol%,
More preferably, the content is in the range of 25 to 35 mol%.

As a method for applying a PVA film layer to the PC film of the present invention, a method in which a PVA film is prepared in advance and then laminated on the PC film can be used. The method of directly coating the solution is preferred.

When the PC film is coated with the PVA solution, it is desirable to previously anchor the surface of the PC film in order to improve the adhesion of the PVA film layer to the PC film.

As the anchoring agent used for the anchoring, those known per se can be used. For example, polyethyleneimine, an organic titanium compound,
Examples include isocyanate compounds, and among them, organic titanium compounds are particularly preferable.

The anchor effect can be further enhanced by subjecting the PC film surface to a surface treatment such as a corona discharge treatment before the anchor treatment.

Examples of the organotitanium compound suitably used as the anchoring agent include, for example, tetra-i-propoxytitanium (TPT), tetra-n-butoxytitanium (TBT), tetrakis (2-ethylhexyloxynotitanium (TOT) ), Tetrastearyloxytitanium (T
ST), di-i-propoxybis (acetylacetoxy) titanium (TAA), di-n-butoxybis (triethanolaminato) titanium (TAT), titanium-
i-propoxyoctylene glycolate (TOG) and titanium stearate, among which TPT,
TBT and TAA are preferred, and TBT is particularly preferably used.

These organic titanium compounds are previously added to the organic solvent in an amount of 0.1 to 20% by weight, preferably 1 to 10% by weight,
More preferably, the composition is dissolved at a concentration of 2 to 5% by weight to prepare a composition for anchor treatment, which is coated on the PC film surface, and the solvent is volatilized so that a thickness of 0.001 to 0.001% is formed on the PC film surface. 3 μm, preferably 0.1 μm.
An anchor coat layer of 1 to 1 μm can be formed.

As a solvent for dissolving the organic titanium compound, a solvent that does not attack the PC film is used.
For example, alcohols such as methanol, ethanol, isopropyl alcohol, hexanol and octanol;
Aliphatic hydrocarbon compounds such as n-hexane and n-heptane; solvents such as mineral spirit and kerosene are used. Among them, aliphatic hydrocarbon compounds, particularly n-hexane, are preferred.

As a method of coating the above-mentioned anchoring composition on the surface of a PC film, for example, a usual coating method such as a gravure roll method, a roller touch method, a bar coater method, a spray method, a dipping method, and a brush coating method can be used. Among them, the gravure roll method and the roller touch method are preferable.

The coating film can be dried by either a natural drying method or a forced drying method. In general, a uniform coating method such as a hot air drying method or an infrared irradiation method can be used. It is preferable in that it can be obtained. The drying temperature varies depending on the boiling point of the dispersion medium used and the like.
0 ° C., particularly in the range of 60 ° C. to 80 ° C., is suitable.

The P which has been subjected to the anchor processing as described above
The PVA solution to be coated on the C film surface is prepared by dissolving PVA in a solvent as described above. As a solvent used for preparing this PVA solution,
For example, water, glycerin, polyethylene glycol and the like can be mentioned, and among them, water is preferable.

When the modified PVA of the above (E) is used as the PVA solution, a mixed solvent of water and isopropyl alcohol is preferably used, and the mixing ratio (weight) of water / isopropyl alcohol at that time is as follows. ,Normal,
(20-80) / (80-20), especially (40-60)
The range of / (40-60) is preferable.

The concentration of PVA in the aqueous solution of PVA is:
It can be varied depending on the thickness of the PVA film layer to be deposited and the degree of polymerization of the PVA, but generally ranges from 0.5 to 3
0% by weight, preferably 2 to 15% by weight, more preferably 5 to 10% by weight is suitable.

The coating of the PVA solution can be carried out by a method known per se, for example, by a coating method such as a gravure roll method, a roller touch method, a bar coater method, a spray method, a dipping method, and a brush application method. In particular, the gravure roll method and the roller touch method are preferably used.

The coating film can be dried by either a natural drying method or a forced drying method. In general, a uniform coating method such as a hot air drying method or an infrared irradiation method can be used. It is preferable in that it can be obtained. The drying temperature varies depending on the boiling point of the used dispersion medium and the like.
C., especially in the range of 60C to 100C. The thickness of the PVA film layer thus formed is generally between 0.
It can be in the range of 1 to 20 μm, preferably 1 to 10 μm, more preferably 2 to 5 μm.

The PC film of the present invention having the fluororesin film layer on one side and the PVA film layer on the other side produced as described above can be used as an agricultural covering material, for example, various vegetables, flowers and plants. It can be used for institutional horticulture of useful crops such as fruit trees.

Hereinafter, the present invention will be described more specifically with reference to examples.

[0103]

EXAMPLES Preparation of Film Comparative Examples 1-4 PC resin (manufactured by Sumitomo Dow Co., Ltd., Caliber 300-4, Sc)
Melt extrusion at 280 ° C. using an extruder to obtain transparent PC films having a film thickness of 50 μm and 150 μm (hereinafter, these films were referred to as “Film No. 1” and “Film No. 1”, respectively). It is called “Film No. 2”.

Further, 2-PC was added to 100 parts by weight of the PC resin.
(4,6-diphenyl-1,3,5-triazine-2-
Il) -5-[(hexyl) oxy] -phenol (ultraviolet absorber) was added and blended in an amount of 1.4 or 0.5 parts by weight. (Hereinafter referred to as “film No. 3” and “film No. 4”, respectively).

Examples 1 to 5 When the weight ratio of PVDF / TFE / HFP is 60/25/15
PVDF copolymer (specific gravity 2.0, melting point 90 ° C) 1
7.5 parts by weight and 6.0 parts by weight of a (methyl methacrylate / ethyl acrylate) copolymer (weight ratio 60/40) were mixed with 17.5 parts by weight of butyl acetate and methyl isobutyl ketone (MIBK). The solution was charged into a mixed solvent consisting of 5 parts by weight and 10.5 parts by weight of toluene and completely dissolved, and then 30 parts by weight of isopropyl alcohol (IPA) was gradually added to prepare a transparent PVDF solution. This solution was coated on one surface of films No. 3 and No. 4, and the solvent was removed by drying to obtain a transparent PC film having a PVDF film layer having a thickness of 3 μm (hereinafter referred to as “film No. 5 "and" Film No. 6 ").

Further, tetra-n-butoxytitanium (T
BT) IPA solution containing 2% by weight was added to the above film N
Coatings of PC films No. 5 and No. 6 were coated with a film thickness of about 20 μm on the side opposite to the PVDF film layer, and the solvent was removed by drying. Subsequently, modified PVA having a saponification degree of 99.8% and a polymerization degree of 1750 obtained by saponifying ethylene having an ethylene content of 29 mol% and a vinyl acetate copolymer was mixed with water / isopropyl alcohol at a weight ratio of 50/50. The mixture was dissolved in a mixed solvent consisting of 50% by weight at 70 ° C. at 15 ° C., cooled to 30 ° C., coated on the surface coated with BTB, and the solvent was removed by drying to form a PVA film layer of about 2 μm. Obtained transparent PC films were obtained (these films are hereinafter referred to as “film No. 7” and “film No. 8”, respectively).

Table 1 shows the characteristics of the films obtained in the above Comparative Examples and Examples.

[0108]

[Table 1]

Evaluation of Physical Properties of Film The physical properties of the films obtained in the above Comparative Examples and Examples were evaluated by the following methods.

(1) Adhesion strength to PC film layer The adhesion strength of the PVDF film layer and the PVA film layer to the PC film was tested by the cross-cut tape method described in JIS K5400.

Adhesion Strength of PVDF Film Layer In each of Film Nos. 5 to 8, the evaluation of the PVDF film layer was “10”, no peeling was observed at all, and the film was strongly adhered.

Adhesion Strength of PVA The evaluation of the PVA film layers of the films No. 7 and No. 8 was “10”.

(2) Surface hardness PVDF film layer surface of film No. 6 and film N
The pencil strength of the PC film surface of o.2 was measured according to JIS K54.
Investigation was carried out in accordance with No. 00. As a result, film No. 6
And in Film No. 2 are “HB” and “B”, respectively, and it is clear that the surface hardness was improved by applying the PVDF film layer.

(3) Chemical resistance 100 ml of each of the various reagents shown in Table 2 was poured into a 200 ml beaker, and then Film No. 6 and Film No. 2 were immersed. PVDF film surface and film No.2 PC
Changes in the film surface were visually inspected and evaluated according to the following criteria. Table 2 shows the results.

…: Excellent in chemical resistance without any change.

X: There is a change and lack of chemical resistance.

[0117]

[Table 2]

(4) Stain resistance PVDF film surface of film No. 5 and film no.
On a PC film surface of No. 1, apply 5 cm x oil-based marking pen (magic ink), lipstick, shoe cream and sauce.
After coating with an area of 5 cm and leaving it overnight, it was wiped off with methanol, and the state of contamination on the film surface was visually inspected.

As a result, Film No. 1 was contaminated by any contaminants, whereas Film No. 1 was contaminated.
5 was not contaminated by any of the contaminants.

Application Examples of Film Reference Examples 1 and Comparative Reference Examples 1 and 2 PCs of Film Nos. 1, 3 and 5 prepared in Example A
The film surface was subjected to corona discharge treatment under the conditions of a discharge current of 10 A, a discharge voltage of 120 V, and a line speed of 13 m / min. Grain printing is performed on the treated surface by gravure printing, and then an acrylic adhesive [Nissetsu PE-154 manufactured by Nissetsu Co., Ltd.] is diluted with IPO to a nonvolatile concentration of 30%, and then applied at 40 g / m ₂ . Let dry.

These films were laminated on a white PVC plate, and this was laminated with a sunshine weather meter (WO).
-M) Exposure, irradiation time 1,000, 1,500, 2,
After 000 hours, the condition was observed, and the results are shown in Table-3.

[0122]

[Table 3]

The observation items and evaluation criteria in Table 3 are as follows.

(1) Discoloration degree of printing ink A: No discoloration is observed.

…: Slight discoloration is observed, but practically, there is almost no problem.

Δ: Discoloration is slightly observed, but it can be used except for some uses.

X: Discoloration is remarkable and cannot be used practically.

(2) Degree of decrease in adhesive strength A: No decrease in strength is observed.

…: A slight decrease is observed, but practically, there is almost no problem.

Δ: Degradation is observed, but it can be used except for some uses.

X: The browning is remarkable and cannot be used practically.

(3) Degree of yellowing of white PVC plate A: No yellowing is observed.

…: Slight yellowing is observed, but practically, there is almost no problem.

Δ: Yellowing is observed, but it can be used except for some uses.

X: The yellowing is remarkable and cannot be used practically.

(4) Practicality A: Excellent in practicality.

…: Excellent in practicality.

X: No practicality was observed.

As is clear from Table 3, it can be seen that the use of the film No. 5 according to the present invention can prevent the deterioration of the printing ink, the adhesive and the PVC.

On the other hand, in film No. 1, W-
In OM 1,000Hrs, printing ink, adhesive,
The PVC was markedly damaged, and was not practical as a surface protective film. Although the film No. 3 was improved in surface protection by the ultraviolet absorber compared to the film No. 1, the deterioration of the PC film surface and the discoloration of the ink were conspicuous as compared with the film No. 5, and the surface protection was apparent. And practicality was hardly recognized.

Reference Example 2 and Reference Comparative Examples 3 and 4 (Examples of Cultivation of Roses) In a house (10 m in frontage and 30 m in depth) in which films Nos. 2, 4 and 8 were respectively spread, film Nos.
No. 2 and No. 4 house inner surfaces were coated with a commercially available dropping agent (Suncall Clear, manufactured by Nitto Boseki Co., Ltd.) and subjected to dropping treatment. 1
On February 15, rose seedlings (variety: curl red) were planted in each house so as to have a plant-to-plant size of 40 cm, and cultivated for one year while maintaining the house temperature at 16 ° C. or higher. The following year, the cultivation was carried out in the same manner, and the roses were harvested from April 15 to November 10. Table 4 shows the results.

[0142]

[Table 4]

[0143] In Table 4, the amount of harvest was
The total number of roses harvested in the house where o.2 was expanded was 1
It was indicated by an index when it was set to 00.

As is clear from Table 4, the film N
A large number of striped black spots appeared on the petals of the rose in the house where o.2 was spread, and these could not be sold as commodities. As a countermeasure, black cold gauze that shields 50% of the light rays is coated on the ceiling of the house every time the sun's rays become strong, and the sun is managed every day so that strong light is not directly irradiated on the roses. The amount of emission decreased to about 1/3, but conversely, when the frequency of using cold gauze was increased and the sunlight dose was controlled, the color of the rose rose light and the so-called color blur phenomenon occurred, resulting in poor quality. It has dropped.

In the house in which the film No. 4 was spread, the drip property of the film was reduced and the humidity in the house was increased, so that the tree was softened and the flower color became a color blur phenomenon.
Gray mold developed. This is presumably because dust and the like adhered to the outer surface of the film and the light transmittance decreased, and these tendencies appeared more strongly.

On the other hand, since the film Nos. 8 and 9 have extremely good light transmittance and dripping properties, the rose in the house on which the films No. 8 and 9 are spread promotes the growth, and the flowering time However, the flower color was four to five days earlier than that of No. 2, the flower color became extremely bright red, the product became highly productive, and the yield was greatly improved.

As described above, in the house where the film No. 8 was spread, the cultivation management became extremely easy as compared with the house where the film Nos. 2 and 4 were spread, and the farmer could grow the rose without fail. In addition, it has become possible not only to obtain a stable harvest, but also to obtain a large amount of high-quality roses, so that a high profit can be obtained.

Reference Example 3 and Reference Comparative Examples 5 to 6 (Tomato Cultivation Examples) Film Nos. 2, 4 and 8 obtained in the examples were spread on a house (10 m wide, 30 m deep). A commercially available dropping agent (Suncall Clear, manufactured by Nitto Boseki) was applied to the inner surfaces of the film Nos. 2 and 4 and subjected to dropping treatment. Cucumbers were cultivated in these houses for one year and tomatoes were cultivated in the second year.

Cultivation-1 On August 25, seeds of tomato (quality: Momotaro) were sown.
Raised seedlings. On October 4th, when the first inflorescence bloomed 2-3 flowers,
Young seedlings having uniform growth were planted in each house so that the distance between the plants was 50 cm.

The amount of fertilization was as shown in Table 5, and irrigation was controlled for about 10 days after planting, so that the young seedlings were not wilted, and managed so as not to grow too much. The cultivation temperature is
The temperature was controlled to be 28 ° C in the morning, 25 ° C in the afternoon, and 5 ° C at night. For this reason, in the low temperature period, warm air was heated by a heater.

[0151]

[Table 5]

Harvesting was carried out from December 8 to May 30 of the following year. The results of the yield survey are shown in Table-6.

[0153]

[Table 6]

The survey items and evaluation methods in Table 6 are as follows.

Harvest amount: An index with the total weight of the harvest and the upper weight of the harvest in the house on which the film No. 2 is spread as 100.

Films No. 2 and No. 4 were inferior in dust-proofing properties, so light transmittance was decreasing, and because of poor dripping properties, the humidity in the house tended to increase.

Under the spreading of Film No. 2, the growth of the tomato was humid and tedious, and the foliage and fruits became soft. As a result, the harvest time was later than the house where other films were spread. further,
With the occurrence of gray mold and its prolongation, yield and quality were greatly reduced.

Under Film No. 4, the growth was reduced due to the lack of light, especially during low sunshine in winter, and the yield and quality were significantly reduced.

On the other hand, under Film No. 8, the amount of transmitted light is abundant, the humidity can be kept low, there is no generation of gray mold and pests, the house can be easily controlled, and high quality tomatoes can be obtained. It became possible to harvest a lot.

Claims (2)

[Claims] 1. A polycarbonate film having an average transmittance of ultraviolet rays of 280 to 320 nm of 60% or less and an average transmittance of visible rays of 400 to 700 nm of 70% or more, and a fluororesin coated on one surface thereof. A fluororesin-coated polycarbonate film comprising a film layer. 2. The film according to claim 1, further comprising a polyvinyl alcohol film layer having a degree of saponification of at least 85 mol% and a degree of polymerization of at least 900 on the other surface of the polycarbonate film.