JPH08187825A - Weatherable moistureproof film - Google Patents

Abstract

PURPOSE: To provide a moistureproof film for coveringly sealing EL element excellent in moistureproofness, light resistance and weatherability. CONSTITUTION: The film consists of laminated film, on at least one side of plastic film 1 of which moistureproof layer 3 is formed. The base material of the moistureproof layer 3 is made of oriented polypropylene. Further, the outermost layer 2 of the laminated film is made of fluorine-based resin film (A) or film (B) containing the partial condensation product of hydrolysis of organo-alkoxysilane and silyl group-containing vinyl resin and preferably made of two layers or of the films (A) and (B), which are different from each other in kind or same as each other. At the opposite side to the outermost layer 2 of the plastic film 1, sealant layer 4 is provided for giving adhesion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated plastic film having a high degree of moisture-proof property, and more specifically to an electroluminescence used as a backlight of a display device such as a sign, which is transparent and hardly permeates gases such as water vapor. The present invention relates to a moisture-proof film for covering and encapsulating an element (hereinafter abbreviated as EL).

[0002]

2. Description of the Related Art EL elements are used for backlights of clocks, pagers, liquid crystal displays, etc. by taking advantage of the features of light weight, thinness, and surface light emitters that are easy on the eyes.
In recent years, it has come to be used also for traffic signs. This EL element is roughly classified into an organic EL element and an inorganic EL element. However, in both cases, the light emission luminance of the fluorescent substance is lowered in a relatively short time due to moisture absorption from the outside, and the usable life is lost. Chlorotrifluoroethylene (hereinafter P
(Hereinafter abbreviated as CTFE) as a main component, or a transparent plastic film having a transparent plastic film on which a transparent oxide thin film of silicon or aluminum is provided. There is.

[0003]

However, since the former laminated film mainly composed of PCTFE is extremely expensive, not only the manufacturing cost of the final backlight becomes high, but also when the light emitting layer is heat-sealed. There is a problem that the stepped portion of the edge is thinned by the sealing pressure, and the moisture absorption from the stepped portion reduces the brightness of the EL from the peripheral portion.

In order to reduce the cost, another transparent film such as polyethylene, or a transparent film provided with a silicon or aluminum type transparent oxide thin film, which replaces PCTFE, has been proposed, both of which are for EL. Is not sufficiently moisture-proof, and the EL element is blackened from the front side, resulting in a decrease in luminance. In particular, when the humidity of the atmosphere used is high, such as during the rainy season, the invasion of water vapor into the EL element becomes significant and the life of the EL element is shortened.

Further, there has been proposed a moisture-proof laminated film in which a synthetic resin layer is laminated on one surface of a laminated body in which rolled polyolefin is laminated via a vapor-deposited silicon oxide layer, and an adhesive layer is laminated on the other surface (Jitsuko Sho 61- No. 42319), rolled polyolefin generally does not have sufficient moisture resistance, and the heat-resistant synthetic resin layer applied as the outermost layer has pinholes in the resin layer due to coating unevenness and cissing due to the nature of the resin. Moisture may be absorbed from the part.

When an EL element is used outdoors such as a traffic sign, not only moisture resistance but also light resistance becomes a problem.
Generally, in order to prevent deterioration of the EL element, 400 to 50
It is necessary to block light with a wavelength of 0 nm or less, and when the moisture-proof film of the EL element uses, for example, polyolefin, yellowing occurs with light of 400 nm or less, so that the wavelength of 500 nm or less as a whole. It is necessary to block the light. However, in the conventional moisture-proof film, the weather resistance of the moisture-proof film including such light resistance is not taken into consideration.

Therefore, it is an object of the present invention to provide a moisture-proof film for EL element coating encapsulation, which is less expensive than PCTFE and is superior in moisture-proof performance. Another object of the present invention is to provide a moisture-proof film for EL element coating encapsulation, which can be manufactured with good workability and is excellent in flexibility. A further object of the present invention is to provide a moisture-proof film having excellent weather resistance as well as moisture resistance.

[0008]

Means for Solving the Problems The weather-resistant moisture-proof film of the present invention which achieves the above object is composed of a laminated film containing a moisture-proof layer, and the moisture-proof layer has a stretched polypropylene as a substrate, and the outermost layer of the laminated film is It is formed of a fluorine resin coating film and / or a coating film containing a hydrolyzed partial condensate of an organoalkoxysilane and a silyl group-containing vinyl resin.

In a preferred embodiment of the present invention, the outermost layer of the weatherproof moisture-proof film is composed of at least two layers having different properties or the same quality. Further, in another preferred embodiment of the present invention, at least one layer constituting the laminated film contains at least one ultraviolet absorber selected from titanium oxide, zinc oxide and cerium oxide. Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of the weather-resistant moisture-proof film of the present invention,
It comprises a plastic film 1, an outermost coating film 2 formed on one surface of the plastic film 1 by coating, a moisture-proof layer 3 attached to the other surface of the plastic film 1, and a sealant layer 4. Such a moisture-proof film is
When used for sealing the L element, the two sheets are overlapped with the EL element sandwiched between them so that the sealant layer 4 is on the inside, and the peripheral portion is heat-sealed with a heat fusion roll or the like.

The plastic film 1 is transparent and has sufficient dimensional stability, for example, a biaxially stretched polyester film such as polyethylene terephthalate. Further, an antistatic agent or the like may be mixed in the film in order to impart antistatic property, an antistatic agent layer may be provided on the surface, and a subbing treatment may be performed to improve the adhesiveness. Is also good. As the antistatic agent, known antistatic agents such as long chain aliphatic amines and amides, phosphoric acid esters, quaternary ammonium salts, polyethylene glycols, polyethylene glycol esters and ethoxylated long chain aliphatic amines can be used. Further, chrome, nickel, gold or the like deposited by vapor deposition with a thickness of 200 angstroms or less can be used. As an undercoating agent, an isocyanate-based, polyethyleneimine-based, organic titanium-based or the like adhesion promoter or a polyurethane polyester-based adhesive or the like can be used. Undercoating treatment such as corona discharge, UV irradiation and ozone treatment May be given.

The thickness of the plastic film 1 is not particularly limited, but it is preferably in the range of 10 to 100 μm, more preferably in the range of 20 to 50 μm in order to facilitate the handling work and laminating work with a laminator or the like. Is used. As the outermost layer coating film 2 formed on one surface of the plastic film 1, a coating containing a fluororesin coating film (A) and / or a hydrolyzed partial condensate of an organoalkoxysilane and a silyl group-containing vinyl resin. A membrane (B) is provided. Such a coating film 2 is formed in order to prevent the moisture-proof layer and the like on the inside from being deteriorated by light from the outside, resulting in deterioration of the moisture-proof function and discoloration.

The fluororesin that forms the fluororesin coating film (A) is one that can be dissolved in an organic solvent or can be stably dispersed in water with an emulsifier, etc., and is applied and dried on the plastic film 1. Any film may be formed later. Examples of such a fluororesin include vinyl fluoride (hereinafter abbreviated as VF) and vinylidene fluoride (hereinafter,
VdF is abbreviated), tetrafluoroethylene (hereinafter,
Examples thereof include a polymer (copolymer) of a fluorine-containing vinyl-based monomer containing, as a main component, TFE), hexafluoropropylene (hereinafter abbreviated as HFP), and the like. Particularly, a copolymer of VdF, TFE and HFP is preferably used, and in this case, the proportion of each monomer is V in molar ratio.
dF is 0 to 85%, preferably 20 to 80%, TFE is 0 to 75%, preferably 10 to 50%, and HFP is 0 to 3.
0%, preferably 10 to 25%. Such a copolymer may be a fluorine-containing monomer such as VF or chlorotrifluoroethylene, a fluorine-containing monomer containing a hydroxy group, a (meth) acrylic acid-based compound represented by the general formula (I) or a hydroxyacrylic acid-based monomer. A monomer, and further, a monomer such as a fluorine-modified acrylic monomer can be contained in a molar ratio of 0 to 60%.

[0013]

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In the formula, R ¹ represents a chain or branched alkyl group having 1 to 8 carbon atoms or a hydroxyalkyl group having 1 to 3 carbon atoms, and examples thereof include C ₂ H ₄ OH and CH ₂ OH. Specific examples of the other monomer copolymerized with the fluorine-containing vinyl-based monomer include vinyl ether monomers such as ethyl vinyl ether and cyclohexyl vinyl ether. In particular, when curability is required as the outermost layer, a hydroxyl group is introduced as the above-mentioned monomer, for example, a monomer such as hydroxybutyl vinyl ether or crotonic acid into which a carboxylic acid is introduced, 3-
Monomers such as butenoic acid are used.

The hydrolyzed partial condensate of the organoalkoxysilane forming the coating film (B) means the organoalkoxysilane represented by the general formula (II) R ² Si (OR ³ ) ₃ (II). It is a hydrolyzate and / or a partial condensate obtained by condensation.
In the formula (I), R ² is an organic group having 1 to 8 carbon atoms, specifically, methyl group, ethyl group, n-propyl group, i-propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group. Group, heptyl group, chain-like octyl group, branched or cyclic alkyl group, γ-chloropropyl group,
Vinyl group, 3,3,3-trifluoropropyl group, γ-
Glycidoxypropyl group, γ-mercaptopropyl group,
Examples thereof include functional alkyl groups such as γ-methacryloxypropyl group, phenyl group, chrysyl group, and 3,4-epoxycyclohexylethyl group, and aryl groups. By setting the carbon number of R ² to be 8 or less, the hydrolysis rate, the drying property of the coating film, and the hardness can be appropriately maintained. R ³ is
A hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group,
Examples thereof include sec-butyl group, tert-butyl group, and acetyl group. By setting the carbon number of R ³ to be 5 or less, the hydrolysis rate, the drying property of the coating film, and the hardness can be appropriately maintained.

Examples of the organoalkoxysilane represented by the general formula (II) include methyltrimethoxysilane,
Methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, γ-chloropropyltrimethoxysilane , Γ−
Chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, γ-glycidoxypropyltrimethoxy Silane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-mercapropropyltrimethoxysilane, γ-mercapropropyltriethoxysilane, phenyltri Examples thereof include methoxysilane, phenyltriethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, and 3,4-epoxycyclohexylethyltriethoxysilane. Methyltrimethoxysilane is preferable. Silane, methyltriethoxysilane, i-propyltrimethoxysilane, γ-chloropropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, 3,4-epoxycyclohexyl Examples thereof include ethyltrimethoxysilane, and more preferably methyltrimethoxysilane and methyltriethoxysilane. These organoalkoxysilanes may be used alone or in combination of two or more.

Further, in addition to the above organoalkoxysilane, an organoalkoxysilane represented by the general formula (III) R ² ₂ Si (OR ³ ) ₂ (III) (wherein R ² and R ³ are the same as above) The hydrolyzate and / or partial condensate thereof can be used in combination. Examples of such organoalkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane. Preferably, dimethyldimethoxysilane and dimethyldiethoxysilane are used.

The weight average molecular weight of the hydrolyzate and / or partial condensate of the formula (II) and (III) organoalkoxysilane is preferably 800 to 100,000, more preferably 1,000 to 50,000. . The silyl group-containing vinyl resin, which is another component of the coating film (B), has, for example, a silyl group having a silicon atom whose main chain is composed of a vinyl polymer and whose end or side chain is bonded to a hydrolyzable group. The polymer contains at least one, preferably two or more in one molecule, and has the general formula (IV)

[0019]

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(R ² and R ³ are the same as above, and n is 1 to
Indicates a positive integer of 3. X represents a monovalent organic group having 2 to 10 carbon atoms and containing a radically polymerizable double bond), and can be produced by copolymerizing a radically polymerizable silane compound represented by it can. Formula (II
As the organic group X of the radically polymerizable silane compound of I), vinyl, 2-propenyl, 3-acryloxypropyl, 3-methacryloxypropyl, 4-vinylgenyl,
2- (4-vinyl) phenylethyl etc. can be mentioned. Further, as various vinyl compounds, any vinyl compound may be used as long as an adduct with a radically polymerizable silane compound can be obtained, for example, methyl (meth) acrylate, (meth)
(Meth) acrylic acid alkyl esters such as ethyl acrylate, butyl (meth) acrylate, and 2-nitrokisethyl (meth) acrylate; unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid, and fumaric acid; Acid anhydrides such as maleic anhydride; amino compounds such as glycidyl (meth) acrylate and aminoethyl vinyl ether;
Acrylamide, crotonamide, itaconic acid amide,
An amide compound such as maleic acid amide; one or more selected from acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, vinyl chloride, vinyl acetate, vinyl propionate, and the like. Preferable examples thereof include alkyl (meth) acrylates, particularly methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and cyclohexyl (meth) acrylate.

The ratio of the radically polymerizable silane compound in the silyl group-containing vinyl resin is 0.0 in terms of silicon element.
It is 1 to 20% by weight, preferably 0.1 to 10% by weight, and by setting it in the above range, the weather resistance and the adhesion can be improved without impairing the storage stability of the composition.
From the viewpoint of coating workability, the silyl group-containing vinyl resin has a weight average molecular weight of 5,000 to 100,000, preferably 10,000 to 50,000, as evaluated by gel permeation chromatography.

The mixing ratio of the hydrolyzed partial condensate of the organoalkoxysilane and the vinyl resin containing a silyl group in the coating film (B) is such that the hydrolyzed partial condensate of the organoalkoxysilane contains 100 parts by weight of the silyl group. The vinyl-based resin is 2 to 600 parts by weight. The coating film (B) preferably contains a metal chelate compound such as zirconium, titanium or aluminum in an amount of 0.01 to 100 parts by weight for the purpose of further promoting the condensation reaction.

These are dissolved in a solvent such as methyl alcohol, isopropyl alcohol, toluene or the like and applied on the plastic film 1. A layer of polyvinylidene chloride may be provided between the plastic film 1 and the outermost layer 2 or between suitable layers for the purpose of further improving the moisture-proof property. The layer of polyvinylidene chloride is 5 ~ 20μ thick
m, preferably about 8 to 15 μm.

Either one of the above-mentioned fluororesin coating film (A) and coating film (B) may be formed on one side of a plastic film, but both coating films are laminated to form a two-layer structure. Good. Further, it may have a two-layer structure in which two or more kinds of fluororesin coating films (A) or coating films (B) having different properties or the same quality are laminated. Although only one outermost layer is shown in the illustrated embodiment, the outermost layer 2 is preferably composed of two kinds of layers having different properties. In that case, the outermost layer is mainly a curable resin that contributes to weather resistance, and the inner layer is a layer for imparting flexibility to the laminated film and preventing pinholes in the outermost layer coating film. A curable resin is used. By having such a two-layer structure, it is possible to impart excellent moisture resistance and flexibility to the laminated film while maintaining sufficient weather resistance, and further, it will stick to the heat fusion roll during heat sealing. Such inconvenience can be prevented, and workability at the time of coating the EL element can be improved.

When the outermost layer has a two-layer structure, the curable resin to be the outer layer is a monomer having a hydroxyl group introduced therein, such as hydroxybutyl ether or a monomer containing a carboxyl group such as crotonic acid or 3-butenoic acid. A fluororesin obtained by copolymerizing Examples of the non-curable resin that forms the inner layer include a fluororesin obtained by copolymerizing two or more kinds of monomers selected from VF, VDF, HFP and alkyl vinyl ether. Coating film (B)
In the case of, by increasing the addition amount of the organoalkoxysilane of the general formula (III) used in combination with the organoalkoxysilane of the general formula (II), the coating film can be made flexible and flexibility can be improved. . Specifically, when the coating film (B) is formed as an inner layer, the coating liquid is an organoalkoxysilane 1 of the general formula (II).
The amount of the organoalkoxysilane of the general formula (III) added is preferably 10 parts by weight or more, and more preferably 20 parts by weight or more, based on 00 parts by weight. On the contrary, when the coating film (B) is formed as an outer layer, the addition amount thereof is preferably 200 parts by weight or less, more preferably 100 parts by weight or less.

The thickness of the coating film of the outermost layer is preferably in the range of 5 to 50 μm, more preferably 10 to 25 μm, in consideration of cost and weather resistance. In the case of a two-layer structure, the thickness of one layer is 5 to 30 μm.
m, and the total thickness is preferably in the range of 10 to 60 μm. Furthermore, the outermost layer 2 and the plastic film 1 are
In order to prevent the plastic and EL device forming the laminated film from being deteriorated by ultraviolet rays, it is desirable to contain an ultraviolet absorber. Generally, a plastic film such as polyolefin is deteriorated or yellowed by ultraviolet rays having a wavelength of 400 nm or less. In particular, the OPP used for the moisture-proof layer 3 described below has poor light resistance to light of 400 nm or less.
In addition, the inorganic dispersion type EL element itself such as zinc sulfide has 400 to 5
It is known that it deteriorates when exposed to light of 00 nm or less. Therefore, it is desirable that the ultraviolet absorber contains an ultraviolet absorber that absorbs electromagnetic waves having a wavelength of 400 nm or less, preferably 500 nm or less. The ultraviolet absorber may be contained in at least one layer of the coating film forming the outermost layer 2 and the plastic film 1, but may be contained in all layers of the outermost layer 2 and the plastic film 1.
This prevents ultraviolet rays from penetrating into the inner layers, and prevents discoloration such as yellowing of the resin forming the layers and the adhesive used between the layers and deterioration of the EL element itself sealed in the moisture-proof film. be able to.

Such an ultraviolet absorber may be any one as long as it absorbs light rays in the above wavelength range without impairing the transparency of the film, and metal oxides such as titanium oxide, zinc oxide, cerium oxide and zirconium oxide. Examples thereof include salicylic acid derivatives, benzophenones, benzotriazoles, organic substances such as substituted acrylonitriles, and nickel complexes. Titanium oxide, zinc oxide, and cerium oxide are preferably used, and zinc oxide is particularly preferable. These metal oxides have a particle diameter of 5 to 100 nm, preferably 10 to 50 nm.

Next, the moisture-proof layer 3 formed on the other surface of the plastic film 1 uses a stretched polypropylene (hereinafter abbreviated as OPP) as a base material, preferably between two such OPP films. A film obtained by laminating a film having a silicon oxide thin film formed thereon (hereinafter referred to as a silicon oxide thin film) is used. Generally, a polyolefin film is used as a base material of a moisture-proof film, but compared to a normal polyolefin film such as polyethylene and polypropylene, OPP has a higher crystallinity when stretched, so that it becomes difficult for water vapor to pass therethrough and the moisture-proof property is improved. Very excellent in transparency. In the present invention, by using such OPP as the base material of the moisture-proof layer, a moisture-proof film having excellent transparency and moisture-proof property can be constructed. The thickness of the OPP film can be up to about 200 μm when it is used as the moisture-proof layer alone, but when it is laminated on both sides of the silicon oxide thin film, it is 10-90 μm, preferably 20-μm. 60μ
The thing of m is used.

Examples of the film used for the silicon oxide thin film include polyvinyl alcohol (hereinafter abbreviated as PVA) film, polyester film, ethylene vinyl alcohol film, and the like.
The VA film is suitable because it functions as a gas barrier against oxygen and the like. The PVA film may be stretched or unstretched, but it is preferable to use a stretched PVA film in terms of film strength and moisture resistance.

The silicon oxide thin film can be formed on a film surface such as a PVA film by a vacuum evaporation method, a sputtering method or an ion plating method using silicon dioxide or the like as a vapor deposition material. Also,
Prior to forming a silicon oxide thin film on the surface of the PVA film, an isocyanate-based, polyethyleneimine-based, organic titanium-based, etc. adhesion promoter and a polyurethane, polyester-based, etc. undercoating agent Can also be used, corona discharge, UV irradiation,
A subbing treatment such as ozone treatment may be performed. Furthermore, P
The VA film may be mixed with an antistatic treatment or an additive such as an antistatic agent or an ultraviolet absorber. As the antistatic agent and the ultraviolet absorber, the same ones as those exemplified for the plastic film 1 can be used.

The thickness of the PVA film is preferably in the range of 5 to 20 μm in consideration of cost and moisture resistance. Moisture barrier 3
Manufactures a film in which a silicon oxide thin film is formed on a PVA film, and uses OPP with an adhesive on both sides of the film.
It can be manufactured by a method of laminating a film. At this time, as the adhesive, urethane-based, acrylic-based, polyester-based or the like can be used. In the case of the structure in which the PVA film in which the silicon oxide thin film is formed is laminated between the two OPP films in this way, the thickness of the entire moisture-proof layer is 20 to 20 in consideration of the texture and the moisture-proof performance.
It is 0 μm, preferably 40 to 200 μm. From the viewpoint of moisture resistance, the thicker the OPP film, the better. However, if it exceeds 200 μm, the texture of the entire laminated film becomes hard and dents or scratches may occur during film handling, or when the EL element is covered and heat-sealed in a later process, light emission occurs. It does not follow the layer thickness skillfully,
A space may be formed between the element and the humidity in the air left in the element, which may cause a problem that the EL element is easily blackened.

The sealant layer 4 is made of a resin which can be sealed by heat sealing and can be provided as a film which is adhesively laminated on the OPP film constituting the moisture-proof layer 3 or as a coating layer which is extrusion-laminated. As the sealable resin, low density polyethylene, ethylene-vinyl acetate copolymer, polypropylene, ethylene-
Although an ethyl acrylate copolymer or the like can be used, it is preferable to use low-density polyethylene, which is well adapted to the shape of the EL extraction electrode, for applications having a high degree of moisture resistance such as a covering and sealing film for EL elements. This allows a complete seal.

The thickness of the sealant layer 4 is at least EL.
It is necessary to have a thickness of at least ½ of the extraction electrode, usually 10 to
It is 100 μm. The method for producing the moisture-proof film of the present invention is not particularly limited, but it can be produced, for example, as follows. That is, first, as shown in FIG. 2, two OPPs are used.
A PVA film 33 having a silicon oxide thin film 32 formed between the films 31 and 31 'is sandwiched to produce a laminated film forming a moisture-proof layer 3, while one side of the plastic film 1 is coated with a fluororesin coating film 21 and A coating film 22 containing a hydrolyzed partial condensate of an organoalkoxysilane and a silyl group-containing vinyl resin is formed.
One surface 31 of the laminated film which becomes such a moisture-proof layer 3
The plastic film 1 on which the weather resistant coating film 2 is formed
Is laminated, and the sealant layer 4 is laminated on the other surface 31 ′ to produce a moisture-proof film.
Further, the plastic film 1 on which the weather resistant coating film 2 is formed
The OPP film 31, the PVA film 33 having the silicon oxide thin film 32 formed thereon, the OPP film 31 ′, and the sealant layer 4 may be sequentially laminated on the other film surface with an adhesive.

The total thickness of the moisture-proof film according to the present invention thus laminated is in the range of 70 μm to 470 μm, preferably in the range of 100 μm to 300 μm. With such a range, sufficient moisture resistance can be obtained, and the texture of the entire film is good,
Appropriate flexibility can be ensured, and EL elements can be sealed and heat-sealed with good workability in the subsequent steps. Further, the weight and cost can be appropriately suppressed.

The structure of the moisture-proof film shown in the figure is an embodiment of the present invention and can be arbitrarily changed within the scope of the claims. For example, the moisture-proof layer 3
As the structure, a PVA film having a silicon oxide thin film formed between two OPP films 31 and 31 'is laminated, but the moisture-proof layer 3 may be composed of only one or more OPP films. A structure in which a PVA film formed with a silicon oxide thin film is laminated on one OPP film may be used. The outermost layer 2 (21, 2)
A layer of polyvinylidene chloride may be provided between 2) and the plastic film 1 and / or between the plastic film 1 and the moistureproof layer 3, whereby the moistureproofness can be further enhanced.

[0036]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited to these examples. Example 1 Two-component curing type fluororesin (Power Freon 3000: Mizutani Paint Co., Ltd.) 20 on one surface of a 50 μm polyester film (T600E: Diafoil Hoechst Co., Ltd.) 20
Double coated with μm, and 20 μm thick biaxially oriented polypropylene film (Sun Orient: manufactured by Nimura Sansho) on the other side, 12 μm polyvinyl alcohol film deposited with silicon oxide (Tech Barrier S: manufactured by Mitsubishi Chemical Corporation) ), A 20 μm biaxially stretched polypropylene film (Sun Orient: manufactured by Nimura Sansho Co., Ltd.), and a 50 μm low density polyethylene film (manufactured by Okura Industry Co., Ltd.) are laminated in this order using a urethane adhesive to obtain the moisture resistance of the present invention. I got a film.

The moisture resistance of the obtained moisture-proof film was evaluated by the moisture-permeable cup method. That is, the moisture permeable cup 2 shown in FIG.
Put 10 ml of water in 0 and cover the upper surface of the moisture-permeable cup 20 so that the sealant layer 4 side of the moisture-proof film 10 is the outer side,
The inside of the cup was sealed with an O-ring 40. This moisture permeable cup 20 was installed in a warm air circulation type constant temperature bath at a temperature of 50 ° C., the change in weight after a certain period of time was measured, and the moisture permeability H was calculated by the following equation.

H = (W ₁ -W ₂ ) / (S × t) W ₁ is the weight of the moisture permeable cup before being put into the constant temperature bath (g) W ₂ is the weight of the moisture permeable cup when taken out from the constant temperature bath (G) S is the total moisture permeation area of the sealed moisture-proof film (m ² ) t is the time during which the moisture-permeable cup is placed in the thermostatic chamber (hr) The results of measurement by this moisture-permeable cup method are shown in Table 1. . Example 2 Soluble fluororesin 1 was formed on one surface of a 23 μm polyester film (T600E: manufactured by DIAFOIL Hoechst).
After coating 0 μm, a two-component curing type fluororesin of 10 μm was further coated thereon in the same manner as in Example 1 to form the outermost layer. On the other side of the polyester film, a thickness of 50
μm biaxially oriented polypropylene film (Sun Orient: manufactured by Nimura Sansho), 12 μm polyvinyl alcohol film deposited with silicon oxide (Tech Barrier S: Mitsubishi Chemical Co., Ltd.), 20 μm biaxially oriented polypropylene film (Sun Orient: Nimura Sansho Co., Ltd.) and a 50 μm low-density polyethylene film (Okura Industry Co., Ltd.) were laminated in this order using a urethane adhesive to obtain a moisture-proof film of the present invention.

The moisture resistance of the obtained moisture-proof film was evaluated by the moisture-permeable cup method. The results are shown in Table 1. Example 3 Vinylidene chloride (D) was formed on one surface of a 23 μm polyester film (T600E: manufactured by Diafoil Hoechst).
(O-877S: manufactured by Kureha Chemical Industry Co., Ltd.) 10 μm, and then the same soluble fluororesin 10 μm and two-component curing type fluororesin 10 μm as in Example 2 are sequentially coated to form the outermost layer and the other side of the polyester film. On the surface
The same moisture-proof layer and sealant layer as in Example 2 were formed to obtain the moisture-proof film of the present invention.

The moisture resistance of the obtained moisture-proof film was evaluated by the moisture-permeable cup method. The results are shown in Table 1. Example 4 Dibutyltin laurate was added as a curing accelerator to the resin composition for the outermost layers 21 and 22 of the following formulation, and one surface of a 23 μm polyester film (T600E: manufactured by Diafoil Hoechst) was sequentially coated to form the outermost layer. Was formed.
A moisture-proof layer and a sealant layer similar to those in Example 2 were formed on the other surface of the polyester film to obtain the moisture-proof film of the present invention. The moisture resistance of the obtained moisture resistant film was evaluated by the moisture permeable cup method. The results are shown in Table 1. Comparative Example 1 Using a 250 μm polychlorotrifluoroethylene film (Nitoflon: manufactured by Nitto Denko Corporation), the same evaluation as in Example 1 was performed, and the results are shown in Table 1. Comparative Example 2 Unstretched polypropylene film having a thickness of 50 μm (Trephan NO: manufactured by Toray Industries, Inc.), 12 μ having silicon oxide deposited thereon.
m polyvinyl alcohol film (Tech Barrier S:
Mitsubishi Chemical Co., Ltd.), 20 μm unstretched polypropylene film (Torayfan NO: Toray Co., Ltd.), and 50 μm low density polyethylene film (Okura Industry Co., Ltd.) are laminated in this order using a urethane adhesive to prevent moisture. I got a film. The moisture-proof film was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0041]

[Table 1]

Example 5 In the laminated film of Example 2, 1 part by weight of zinc oxide having an average particle diameter of 20 nm was added to 1 part by weight of 100 parts by weight of the fluororesin in the outermost two-component curable fluororesin. A laminated film was produced in the same manner as in. This laminated film and the film of Comparative Example 2 were 500 times with a Sunshine weather meter.
When the light resistance was tested for 1 hour and 1000 hours, the film of Comparative Example 2 was colored dark brown, whereas the film of Example 5 was colored only a faint yellow color.

Further, the flexibility of the films obtained in Examples 1 to 5 was evaluated by the following test methods. That is, the film has a predetermined size (width 1 inch x
A test piece having a length of 110 mm) was overlapped at both ends in the length direction to form a cylinder having a circumference of 100 mm, and a needle having a diameter of 3 mm was pushed in from the outside at a constant speed, and the force applied to the needle at that time was measured. As a result, all the films showed the same flexibility as the fluorine film (Comparative Example 1).

[0044]

As is clear from the above examples, the weather-resistant moisture-proof film of the present invention exhibits higher moisture-proof property than the conventional laminated moisture-proof film, and has a moisture-proof property equal to or higher than that of the PCTFE film. And exhibits practicality as a sealing material for EL devices. In addition, the moisture-proof film of the present invention is a film having excellent weather resistance in addition to a moisture-proof layer having a high moisture-proof property using OPP as a substrate, so that even if OPP is used, it is a film. It is possible to prevent the deterioration of UV rays. Therefore, the moisture-proof film of the present invention is suitable for applications requiring high moisture-proof performance, such as plastic films for sealing and encapsulating EL elements that are used for a long time under severe conditions. Furthermore, since the moisture-proof film of the present invention is excellent in terms of flexibility and cost efficiency, when used as a film for sealing and covering EL elements, work can be performed with good workability without causing dents on the film surface. There is an advantage that you can.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing another embodiment of the present invention.

FIG. 3 is a diagram showing an apparatus for evaluating the moisture resistance of the film of the present invention.

[Explanation of symbols]

 1 ... Plastic film 2 ... Outermost layer coating 3 ... Moisture-proof layer 4 ... Sealant layer

Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H05B 33/04 (72) Inventor Seiji Aoya 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. In-house (72) Inventor Masaji Watanabe 2-11-21 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd.

Claims (3)

[Claims] 1. A laminated film including a moisture-proof layer, wherein the moisture-proof layer has a stretched polypropylene as a substrate, and the outermost layer of the laminated film is a fluororesin coating film and / or hydrolysis partial condensation of organoalkoxysilane. A weather-resistant moisture-proof film, which is formed from a coating film containing a product and a vinyl resin containing a silyl group. 2. The weather-resistant moisture-proof film according to claim 1, wherein the outermost layer comprises at least two layers having different properties or the same quality. 3. At least one of the layers constituting the laminated film
The weather-resistant moisture-proof film according to claim 1, wherein the layer contains at least one ultraviolet absorber selected from titanium oxide, zinc oxide and cerium oxide.