KR100568766B1 - Moistureproof multilayered film - Google Patents

Abstract

In the moisture proof multilayer film containing the composite film in which the inorganic oxide or the metal vapor deposition film was formed in at least one surface of the non-hygroscopic resin layer, the vapor deposition film surface of the said composite film is another non-hygroscopic resin layer surface or another composite through an adhesive bond layer. It consists of a multilayer film containing the laminated constitution laminated | stacked with the vapor deposition film surface of a film, and the total number of layers (n) of the vapor deposition film laminated adjacent to an adhesive bond layer is 2-8, and the temperature is 40 degreeC, and the relative humidity 100%. Moisture permeability (Ｗ; unit = g / m 2 · day) measured under the following formula (1)

Ｗ≤ (1 / n) Ｘ0.20 (1)

Provided are a method for producing a moisture proof multilayer film satisfying the relationship of the above and a multilayer heat treatment of the multilayer film in a dry heat atmosphere of 55 ° C. or more and 140 ° C. or more for 10 hours or more.

Description

Moisture-proof multilayer film {MOISTUREPROOF MULTILAYERED FILM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture proof multilayer film having a high moisture proof performance, and more particularly, to a moisture proof multilayer film which is very suitable as a packaging material or sealing material for food, pharmaceuticals, electronic parts and the like, and a manufacturing method thereof. The moisture proof multilayer film of the present invention can exhibit moisture resistance comparable to a polychlorinated trifluoride ethylene film, and is particularly suitable as a package film for sealing electronic components such as an electroluminescent device.

Conventionally, a composite film in which an inorganic oxide or a metal deposition film is formed on the surface of a synthetic resin film has good oxygen gas barrier properties and water vapor barrier properties, is excellent in transparency, and furthermore, when the deposition film is a silicon oxide thin film or the like, Because of its range suitability, it is used as a packaging material or sealing material for food, pharmaceuticals, electronic parts, and the like. A composite film having a vapor deposition film formed on at least one surface thereof can be formed as a multilayer film that protects the vapor deposition film by providing various functions such as strength, heat resistance and heat sealing property by laminating various synthetic resin films on one or both surfaces thereof. have.

However, the conventional composite film containing a vapor deposition film cannot sufficiently lower the moisture permeability, and therefore is not necessarily suitable as a package film for sealing an electronic component, for example, where high moisture resistance is required. This problem will be described below in more detail by taking an electroluminescent element (EL element) as an example.

The action of applying an electric field to a solid (phosphor) of a fluorescent compound to convert electrical energy into luminescence energy of fluorescence is called electroluminescence. Electroluminescence can be classified into a thin film type and a distributed type from the basic element structure.

The thin film type EL element includes a light emitting layer made of a thin film of phosphor. The dispersion type EL device includes a light emitting layer obtained by dispersing a powder phosphor in an organic or inorganic binder. The EL element has an element body sandwiched by a pair of electrodes directly or via an insulating layer, and a transparent electrode is used for at least one of the pair of electrodes. If the fluorescent substance which comprises a light emitting layer absorbs moisture, the light emission luminance will remarkably deteriorate. Therefore, the EL element has a structure in which the EL element main body in which the light emitting layer is disposed between a pair of electrodes is covered (sealed) with a transparent moisture proof material.

  Conventionally, a polychlorinated trifluoride ethylene (PCTFE) film or a glass substrate is used as a moisture proof material of an EL element. The PCTFE film has the most excellent moisture proof property among synthetic resin films, but the cost is high, and when the ambient temperature becomes a high temperature exceeding 50 ° C, the moisture proof property is remarkably lowered. Therefore, the EL element sealed with the PCTFE film has the problem that the lifetime under high temperature and high humidity becomes extremely short. On the other hand, a glass substrate has a limit to thinning and weight reduction, and also has a problem that it lacks flexibility. Moreover, it is difficult to seal an EL element main body only with a glass substrate, and combined use of a flexible moisture proof film is indispensable.

Therefore, the development of the moisture proof film which has the high moisture proof performance which can replace the PCTFE film was desired. Conventionally, as a resin material replacing PCTFE, polyvinylidene chloride, polyvinyl alcohol, and the like have been studied, and further, a synthetic resin film having an inorganic oxide or a metal deposited film has also been studied. However, it has been difficult to develop a moisture proof material having high moisture resistance and moderate flexibility comparable to PCTFE films.

For example, Japanese Patent Application Laid-Open No. Hei 8-300549 discloses that at least the biaxially stretched plastic film / film / adhesive number configured such that the coating surface of the biaxially stretched plastic film having a film having gas barrier property is in contact with the adhesive resin layer. In a laminate film made of a stratum layer / flexible film, the biaxially stretched plastic film is heated at a temperature equal to or more than the glass transition point and the melting point of the biaxially stretched plastic film, and at that time, the length of the biaxially stretched plastic film The method of improving gas barrier property is disclosed by setting the range of the expansion ratio of the direction MR within 2% of elongation rate and within 5% of shrinkage rate. In this publication, an inorganic oxide or a metal deposited film is indicated as a film having gas barrier properties.

In the method of the said publication, when heating a laminated film, it passes between two independent drive rolls (A) and (B), and adjusts the rotational speed of each independent drive roll, and the expansion ratio of a laminate film Is in control. Specifically, the circumferential speed of the drive roll A is adjusted to 1.02-0.95 times the circumferential speed of the drive roll A, and the laminated film is heated under tension. Moreover, in the method of the said publication, it is preferable to make heating temperature into glass transition point +70 degreeC or more and melting | fusing point or less of a biaxially-stretched plastic film. In the examples of the publication, under tension of the laminate film, 1.5 seconds on a thermal roll at 230 ° C. (Example 1), 3.2 seconds on a thermal roll at 190 ° C. (Example 2) and 0.9 seconds on a thermal roll at 250 ° C. (Example 3 ), The example which touched each is shown. In another embodiment of the above publication, the laminate film is slowly sent between two rolls that independently drive, for 10 minutes in a heating furnace at 170 ° C (Example 4), and 2 minutes in a heating furnace at 210 ° C (execution). Example 5) The example which heated each is shown. By this method, an example in which the moisture permeability of the laminate film (measured at 40 ° C. and a relative humidity difference of 90% by the cup method) was improved from 1.5 g / m ² · day before heat treatment to 0.6 g / m ² day after heat treatment Is indicated (Example 4). However, the value of this moisture permeability is far below the level (about 0.3 g / m 2 · day) of the water vapor transmission rate of the PCTFE film.

In recent years, the present inventors have found that a moisture-proof film having excellent moisture-proof performance can be obtained by drying a transparent multilayer film in which an inorganic oxide thin film is disposed directly on both surfaces of a hygroscopic resin layer such as polyvinyl alcohol or via an adhesive layer. (PCT / JP98 / 01781). However, as for this moisture proof film, it is essential to use hygroscopic resin, and there existed a limitation in selection of a resin material. In addition, in order to suppress the moisture permeability in addition to the moisture permeability, this moisture-proof film needed to dry the said hygroscopic resin layer to the completely dry state by the advanced drying process including vacuum drying.

An object of the present invention consists of a multi-layer film comprising a non-hygroscopic resin layer and a vapor-deposited film containing a composite film having an inorganic oxide or metal deposited film formed on at least one side of the non-hygroscopic resin layer, thereby providing high moisture-proof performance. It is providing the moisture proof multilayer film shown and its manufacturing method.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to overcome the problem of the said prior art, the vapor deposition film surface of the composite film in which the inorganic oxide or the metal vapor deposition film was formed in at least one surface of the non-hygroscopic resin layer is made into another ratio through an adhesive layer. The multilayer film which contains the laminated constitution laminated | stacked with the vapor deposition film surface of the hygroscopic resin layer surface or another composite film, and is laminated | stacked adjacent to an adhesive bond layer is produced, The multilayer film which is 2-8 is produced, and then the said multilayer film By heat-treating at a relatively low temperature of less than 140 degreeC for a long time, it discovered that the moisture proof multilayer film which has the high moisture proof performance comparable to a PCTFE film, and has moderate flexibility and flexibility is also obtained.

According to the method of the present invention, it is not necessary to heat-treat the multilayer film under tension, and for example, heat treatment can be performed by holding the multilayer film in a heating furnace in a state of being rolled back. Therefore, the method of the present invention is suitable for mass production. Moreover, in the method of this invention, heat processing can be performed at the comparatively low temperature of 55 degreeC or more and less than 140 degreeC. According to the experimental results of the present inventors, when the heat treatment of the multilayer film at a high temperature tends to reduce the moisture permeability, especially when the heat treatment is performed at a high temperature of 170 ° C. or higher, the moisture permeability is found to be remarkably decreased. In addition, in the method of this invention, a hygroscopic resin layer is not essential and it is not necessary to dry the hygroscopic resin layer to a completely dry state. The moisture-proof multilayer film of this invention can have flexibility which is very suitable for apply | coating as a moisture proof material of an EL element main body, for example by adjusting the total number of layers of a vapor deposition film to an appropriate range. The present invention has been completed based on these findings.

Thus, according to this invention, in the moisture proof multilayer film containing the composite film in which the inorganic oxide or the metal vapor deposition film was formed in at least one surface of the non-hygroscopic resin layer, the vapor deposition film surface of the said composite film is via an adhesive bond layer, It consists of a multilayer film which contains the laminated constitution laminated | stacked with the vapor deposition film surface of another non-hygroscopic resin layer surface or another composite film, and is laminated | stacked adjacent to an adhesive bond layer, and the total layer number n is 2-8, and is a temperature The water vapor transmission rate (W; unit = g / m 2 · day) measured under the conditions of 40 ° C. and 100% relative humidity is represented by the following formula (1).

W≤ (1 / n) × 0.20 (l)

A moisture proof multilayer film is provided that satisfies the relationship.

Moreover, according to this invention, in the manufacturing method of the moisture proof multilayer film containing the composite film in which the vapor deposition film of an inorganic oxide or a metal was formed in at least one surface of the non-hygroscopic resin layer,

(1) The total layer number of the vapor deposition film surface of the composite film containing the laminated constitution laminated | stacked with the vapor deposition film surface of another non-hygroscopic resin layer surface or another composite film via an adhesive bond layer, and an adhesive bond layer and laminated | stacked adjacently. (n) produced the multilayer film of 2-8, and then

(2) A method for producing a moisture resistant multilayer film is provided which heat-treats the multilayer film in a dry heat atmosphere at 55 ° C. or higher and less than 140 ° C. for 10 hours or more.

The invention will be more fully understood by the following detailed description. Further scope of applicability of the present invention will become apparent from the following detailed description.

However, detailed description and specific Example are preferred embodiment of this invention, and are described only for the purpose of description. In this detailed description, various changes and modifications are apparent to those skilled in the art within the spirit and scope of the present invention.

Applicants have no intention of offering any of the described embodiments to the public, and any of the disclosed modifications and alternatives, which may not be included in the text within the scope of the claims, are part of the invention under equality.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional schematic diagram showing a layer structure of an example of a moisture-proof multilayer film of the present invention.

Fig. 2 is a cross-sectional schematic diagram showing a layer structure of another example of the moisture resistant multilayer film of the present invention.

Fig. 3 is a cross-sectional schematic diagram showing the layer structure of another example of the moisture resistant multilayer film of the present invention.

4 is a cross-sectional schematic diagram showing a layer structure of another example of the moisture resistant multilayer film of the present invention.

Fig. 5 is a cross-sectional schematic diagram showing the layer constitution of another example of the moisture resistant multilayer film of the present invention.

6 is a cross-sectional schematic diagram showing an example of a layer structure of an electroluminescent (EL) element.

7 is a schematic cross-sectional view showing another example of the layer structure of an EL element.

<Description of Symbols for Main Parts of Drawings>

1: Biaxially oriented PET film 2: Deposition film of silicon oxide

3: biaxially stretched PET film 4: deposited film of silicon oxide

a _l : urethane adhesive layer a ₂ : urethane adhesive layer

X: Deposition Film Y: Deposition Film

61: light emitting layer 62: electrode

63 substrate 64 electrode

65 substrate 66 moisture proof material

67: moisture barrier 71: moisture barrier

72: moisture absorption film 73: transparent conductive film

74: light emitting layer 75: dielectric layer

76: back electrode 77: moisture absorption film

78: moisture proof material

The moisture proof multilayer film of this invention is a thing comprised from the multilayer film which has a non-hygroscopic resin layer, a vapor deposition film, and an adhesive bond layer, and has two or more layers of each of these layers, respectively.

① Non-hygroscopic resin layer

  The non-hygroscopic resin used in the present invention means a synthetic resin having a water absorption (JIS K-7209) of usually 1.0% or less, preferably 0.8% or less, and more preferably 0.5% or less. As such a non-hygroscopic resin, Polyolefin resin, such as polyethylene, a polypropylene, poly-4-methyl pentene; Polyester-based resins such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; Chlorine-containing resins such as polyvinyl chloride and polyvinylidene chloride; Polyvinyl aromatic resins such as polystyrene; Polycarbonate, polyphenylene sulfide, polyimide, polysulfone and the like.

The layer made of non-hygroscopic resin may be either an unstretched film or a stretched film, but is preferably a biaxially stretched film such as biaxially stretched polyethylene terephthalate. Moreover, it is preferable that a non-hygroscopic resin layer has shape retention property at the said heat processing temperature in the non-hygroscopic resin whose melting | fusing point, a non-cut softening point, or decomposition temperature are more than predetermined heat processing temperature.

   Although the thickness of a non-hygroscopic resin layer is not specifically limited, Usually, 5-400 micrometers, Preferably it is 8-200 micrometers, More preferably, it is 10-100 micrometers. In the case where the non-hygroscopic resin layer is a biaxially stretched film, the thickness thereof is sufficient as about 10 to 20 µm in many cases. The non-hygroscopic resin layer can contain additives such as antioxidants, ultraviolet absorbers, antistatic agents, colorants, lubricants, plasticizers, and flame retardants as necessary. In order to improve the adhesion of the deposited film, the surface of the non-hygroscopic resin layer can be subjected to corona discharge treatment, plasma treatment, ozone treatment, ultraviolet irradiation treatment, electron beam irradiation treatment, primer coating treatment and the like in advance. Among these, primer treatment is especially preferable. It is preferable that non-hygroscopic resin is excellent in transparency.

In this invention, although a non-hygroscopic resin layer forms a vapor deposition film in at least one surface, and uses it as a composite film, the non-hygroscopic resin layer which does not form a vapor deposition film can also be used as a layer component of a multilayer film according to an arm | hole. .

② Deposition film of inorganic oxide or metal

The inorganic oxide or metal deposited film is formed on one side or both sides of the non-hygroscopic resin layer. However, considering the flexibility and flexibility of the multilayer film, it is preferable to form only one side. As an inorganic oxide, Metal oxides, such as aluminum oxide, zinc oxide, tin oxide, indium oxide, titanium oxide, and mixtures thereof; Si0, there can be mentioned a silicon oxide such as SiO _2, and mixtures thereof. Examples of the metal include aluminum, gold, silver, platinum, palladium, tin, nickel, cobalt, zinc, titanium, indium, and mixtures thereof. Among these, vapor deposition films, such as silicon oxide, aluminum, aluminum oxide, are preferable, and the vapor deposition film of silicon oxide is especially preferable. The silicon oxide vapor deposition film may contain impurities, such as calcium, magnesium, or these oxides, as long as it is a small quantity of 10 weight% or less.

The vapor deposition film can be formed on at least one surface of the non-hygroscopic resin layer (non-hygroscopic resin film) by vacuum vapor deposition (physical vapor deposition, chemical vapor deposition, etc.), ion plating, sputtering, reactive vapor deposition, or the like. The reactive vapor deposition method is a method of vapor deposition using a metal, an inorganic oxide, or the like as a vapor deposition material and supplying oxygen gas. The vacuum evaporation method and the like are well known to those skilled in the art, and can be carried out in accordance with the conventional methods, respectively.

The thickness of the deposited film is usually 10 to 500 nm, preferably. 20-200 nm, More preferably, it is 30-100 nm. If the thickness of the deposited film is too thin, moisture resistance is insufficient, and if it is too thick, curling may occur in the film or cracks or peeling of the deposited film itself will likely occur. As a non-hygroscopic resin film in which such a vapor deposition film was formed, you may use a commercial item. As a preferable commercial item, Tek barrier series, such as the tekbari H, tekbari U, tekbari T, and tekbari V by Mitsubishi Kagaku Kyojin Park Co., Ltd .; MOS series, such as MOS-TH and MOS-TB made from Oike Industries, Inc., etc. are mentioned. All of these formed the vapor deposition film of a silicon oxide on one side of a biaxially stretched polyethylene terephthalate film (biaxially stretched PET film). Among these, a technical barrier barrier series is preferable at the point which the improvement effect of the moisture proof performance by heat processing is remarkable.

③ Adhesive layer

In this invention, the layer in which the vapor deposition film surface of the composite film in which the inorganic oxide or metal vapor deposition film was formed in at least one surface of the non-hygroscopic resin layer was laminated | stacked with the other non-hygroscopic resin layer surface or the vapor deposition film surface of another composite film via an adhesive bond layer. The multilayer film which has a structure is produced. Here, the other non-hygroscopic resin layer surface may be either one surface of the non-hygroscopic resin layer (film) in which the vapor deposition film is not formed, and also the non-hygroscopic resin layer surface of the composite film in which the vapor deposition film is formed on one surface. do. Moreover, another composite film means the same kind of composite film, ie, the composite film in which the vapor deposition film of an inorganic oxide or a metal was formed in at least one surface of the non-hygroscopic resin layer.

In order to produce such a multilayer film, Preferably, two or more composite films in which the inorganic oxide or the metal vapor deposition film was formed in one side of a non-adsorbing resin layer are used, and these are laminated | stacked using an adhesive agent. When using the composite film in which the vapor deposition film was formed on both surfaces of a non-hygroscopic resin layer, it may be one said composite film, but considering the flexibility and the flexibility, it uses two or more composite films in which the vapor deposition film was formed in one side. It is preferable. Moreover, you may use in combination with a composite film the non-hygroscopic resin layer (film) in which the vapor deposition film is not formed as needed.

As an adhesive agent, various adhesive agents, such as a urethane type, an acryl type, and polyester type, can be used. Among these, the two-liquid reaction type which consists of a urethane type polyol component and a polyisocyanate component is preferable. As a urethane type adhesive agent, what forms polyether type polyurethane resin and polyester type polyurethane resin by reaction, It is preferable to form polyester type polyurethane resin. As a preferable two-component reaction type urethane type adhesive agent, AD-502 / CAT-10, AD-578A / CAT-10 etc. which are marketed from Toyo Morton Corporation are mentioned.

The thickness of an adhesive bond layer is 1-50 micrometers normally, Preferably it is 2-10 micrometers, More preferably, it is about 3-5 micrometers. It is preferable to form an adhesive bond layer by apply | coating an adhesive agent on a vapor deposition film surface or a film surface, and drying by a dry lamination method. After forming an adhesive bond layer, a multilayer film can be produced by carrying out dry lamination according to a conventional method, such as nipping and bonding each layer with a hot roll.

④ multilayer film

The basic layer structure of the multilayer film used by this invention is demonstrated, referring FIGS. 1-5. As shown in FIG. 1, by using two composite films X in which the vapor deposition film 2 was formed on one surface of the non-hygroscopic resin layer 1, the vapor deposition surfaces of each composite film were opposed to each other, The multilayer film which has a laminated constitution of the "non-hygroscopic resin layer / vapor deposition film / adhesive layer / vapor deposition film / nonhygroscopic resin layer" laminated | stacked through the adhesive bond layer (a1) is illustrated. In FIG. 2, "The non-hygroscopic resin layer / vapor deposition film / adhesive layer / vapor deposition film / non-hygroscopic resin layer / adhesive agent which used three composite films X in which the vapor deposition film 2 was formed in one surface of the non-hygroscopic resin layer 1 is used. Layer / deposition film / non-hygroscopic resin layer &quot;. 3, the composite film X in which the vapor deposition film 2 was formed in one side of the non-hygroscopic resin layer 1, and the composite in which the vapor deposition film 4 was formed in one side of the non-hygroscopic resin layer 3 are shown in FIG. `` Non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer using four sheets in total with two films (Y). The multilayer film which has a laminated constitution of is shown.

In FIG. 4, four composite films X in which the vapor deposition film 2 is formed on one side of the non-hygroscopic resin layer 1 are used, and the adhesive layer a ₂ indicates the "non-hygroscopic resin layer / deposition film / The example which produced the multilayer film which has a laminated constitution of "adhesive layer / vapor deposition film / non-hygroscopic resin layer / adhesive layer / non-hygroscopic resin layer / vapor deposition film / adhesive layer / vapor deposition film / non-hygroscopic resin layer" is shown. Figure 5, except that the adhesive layer (a ₁₎ in place of the adhesive layer (a _2), is an example produced by the multi-layer film having a layer structure similar to that shown in FIG. About the example of the specific laminated constitution of the multilayer film shown in these FIGS. 1-5, it shows in Examples 1-5.

  As a preferable laminated constitution including the above, the following multilayer constitution is illustrated.

(1) Non-hygroscopic Resin Layer / Deposition Film / Adhesive Layer / Deposition Film / Non Hygroscopic Resin Layer

(2) non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / deposition film / non-hygroscopic resin layer

(3) Non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / deposition film / non-hygroscopic resin layer

(4) Non-hygroscopic resin layer / deposition film / adhesive layer / non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / deposition film / non-hygroscopic resin layer

(5) Non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer

(6) non-hygroscopic resin layer / deposition film / adhesive layer / non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer

(7) non-hygroscopic resin layer / deposition film / adhesive layer / non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / Adhesive Layer / Deposition Film / Non Hygroscopic Resin

(8) non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / deposition film / non-hygroscopic resin layer / Adhesive Layer / Deposition Film / Non Hygroscopic Resin Layer                 

(9) Non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / nonhygroscopic resin layer / deposition film / Adhesive Layer / Deposition Film / Non Hygroscopic Resin Layer

(10) non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer /

Non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / non-hygroscopic resin layer / deposition film / adhesive layer / deposition film / non-hygroscopic resin layer / adhesive layer / deposition film / non-hygroscopic resin layer

The layer structure of a multilayer film is not limited to the above. The total number of layers of the vapor deposition film laminated | stacked adjacently (contact | contact) with the adhesive bond layer in a multilayer film is 2-8, Preferably it is 2-6. When the total layer number of the vapor deposition film adjacent to an adhesive bond layer is three or more layers, a low moisture-permeable multilayer film can be obtained stably easily. As the total number of layers of the vapor-deposited film increases, the moisture-proof performance of the multilayer film improves, but since flexibility and flexibility decrease, bending processing and the like become difficult. Moreover, when the total number of layers of a vapor deposition film is made large, it is not economical. On the other hand, when there is only one vapor deposition film, it is difficult to realize sufficiently low moisture permeability even by heat treatment. According to the method of the present invention, it is possible to obtain a multilayer film having a high moisture-proof performance (low moisture permeability) comparable to a PCTFE film at a total number of layers of about 2 to 6 of the deposited film. The total number of layers of the vapor deposition film is usually adjusted by the number of sheets of non-hygroscopic resin film in which a vapor deposition film is formed on one surface. Moreover, the vapor deposition film which is not adjacent to an adhesive bond layer may exist additionally.

As shown in FIG. 1, the multilayer film used in the present invention comprises at least two composite films (X) having an inorganic oxide or metal deposited film formed on one side or both sides (preferably one side) of the non-hygroscopic resin layer. It is preferable that it contains each sheet and at least 2 sheets of a composite film have the laminated constitution laminated | stacked on the vapor deposition film surface mutually via the adhesive bond layer. It is preferable that the laminated constitution laminated | stacked on the vapor deposition film surfaces mutually via the adhesive bond layer contains 1-4, Preferably 1-3, More preferably, 1-2 in a multilayer film. By including the layer structure laminated | stacked on the vapor deposition film surface of each other via an adhesive bond layer in a multilayer film, high moisture-proof performance can be provided after heat processing. Moreover, by using two or more composite films in which a vapor deposition film is formed on one surface and laminating the vapor deposition film surfaces via an adhesive layer, the moisture-proof performance can be improved without impairing the flexibility and flexibility of the multilayer film. Can be. Moreover, by setting it as such a layer structure, the total number of layers of the vapor deposition film required for the improvement of moisture proof performance can be ensured, suppressing the number of sheets of each layer in the basic layer structure of a multilayer film.

Although the multilayer film used by this invention has the basic laminated constitution as mentioned above, for the purpose of improving strength, heat resistance, providing heat sealing property, etc., if desired, the resin layer which does not have a vapor deposition film may be the innermost layer, the outermost layer. One or more layers can be arrange | positioned as an outer layer or an intermediate | middle layer. It is preferable that this additional resin layer is a layer which consists of synthetic resin which has transparency. As this additional resin layer, the thing similar to the non-hygroscopic resin layer mentioned above can be used. In addition, as an additional resin layer, for example, a heat-treated film (Japanese Patent Laid-Open No. Hei 6-220221) formed from a mixture of polyvinyl alcohol (PVA) and poly (meth) acrylic acid or its partial neutralized product, sugars and Gas barrier films, such as heat-treated films (Japanese Patent Laid-Open No. 7-165942) formed from a mixture with poly (meth) acrylic acid or its partial neutralized material, and these gas barrier films are provided on at least one side of the thermoplastic resin layer. The formed composite film etc. can be used. As the additional resin layer, in addition to the above, a layer made of hygroscopic resin such as PVA, ethylene-vinyl acetate copolymer saponified material (EVOH), polyamide, or the like may be used. If desired, the additional resin layer may contain additives such as a ultraviolet absorber or a pigment for color conversion of the EL element.

In order to provide heat sealing property to the moisture proof multilayer film of this invention, a heat-sealing resin layer can be arrange | positioned in an innermost layer (layer which performs a heat seal). As a heat-sealing resin layer, a polyolefin type hot melt type sealant layer, an epoxy type hot melt type sealant layer, etc. are preferable, for example. The thickness of this sealant layer is about 10-300 micrometers normally. When sealing an EL element main body using the moisture proof multilayer film of this invention, you may arrange | position a heat sealing resin layer only to the site | part which surrounds an EL element main body.

These additional resin layers can be used individually or in combination with another resin layer, respectively. Moreover, although these additional resin layers can be arrange | positioned in the predetermined | prescribed position in a multilayer film via an adhesive bond layer, you may heat-seal together without using an adhesive bond layer depending on a case. In addition, the additional resin layer may be laminated on one side or both sides of the multilayer film after the heat treatment of the multilayer film. It is preferable to laminate | stack a hot melt sealant layer after the heat processing of a multilayer film.

It is preferable that both the multilayer film which has a basic laminated constitution as mentioned above, and the multilayer film which arrange | positioned the additional resin layer have transparency. Although the degree of transparency differs according to the purpose of use here, for example, when using a moisture proof multilayer film as a moisture proof material of an EL element main body, it is necessary to be transparent so that the light from a light emitting layer can permeate | transmit.

⑤Heat treatment

In the manufacturing method of this invention, a moisture proof performance is remarkably improved by heat-processing a multilayer film (including the thing in which the additional resin layer was arrange | positioned) on specific conditions. When using reactive adhesives, such as a two-component reaction type urethane type adhesive agent, as an adhesive agent, the aging process for reaction of an adhesive agent is performed before heat processing. In the manufacturing process of a multilayer film, when manufacturing a multilayer film using a urethane type adhesive agent for an adhesive bond layer, it is preferable to heat-process after performing the aging process of an adhesive agent for 24 hours or more in the temperature range of 30-50 degreeC. Do. If the aging treatment temperature is too low, the curing reaction is too late. If the aging treatment temperature is too high, foaming is caused by the production of gas, which adversely affects the moisture permeability. As for the aging treatment temperature, 40 degreeC is more preferable. The aging treatment time is preferably 24 hours (1 day) to 168 hours (7 days), more preferably about 48 hours (2 days) to 96 hours (4 days).

In the heat treatment step of the multilayer film, the multilayer film is heat treated for 10 hours or more in a dry heat atmosphere of 55 ° C or higher and 140 ° C or lower. Heat processing temperature becomes like this. Preferably it is 60-130 degreeC, More preferably, it is 70-120 degreeC. If the heat treatment temperature is too low, a long time is required to sufficiently reduce the moisture permeability of the multilayer film, and the productivity decreases. On the other hand, when the heat treatment temperature is too high, the effect of lowering the moisture permeability is small, or the moisture permeability is increased. The heat treatment time is preferably 30 hours or more, more preferably 100 hours or more. The heat treatment time is preferably short when the heat treatment temperature is high, and long when the heat treatment temperature is high, in order to stably obtain a value of the productivity and a small moisture permeability. Although there is no upper limit in particular of heat processing time, when heat processing temperature is low, it is about 1200 hours.

The heat treatment does not need to be carried out under tension, and can be carried out under tension. Prior art (Japanese Patent Application Laid-open No. Hei 8-300549) teaches a heat treatment for a short time at high temperature under tension, but is surprising when the multi-layered film of the layer structure of the present invention is heat-treated, and is relatively low under tension. By carrying out heat treatment for a long time at a temperature, a multilayer film having a moisture-proof performance comparable to a PCTFE film can be obtained. In order to perform heat processing on an industrial scale, the method of hold | maintaining predetermined time in the heating furnace adjusted to predetermined temperature in the state which wound the multilayer film into roll shape is preferable. By adopting such a heat treatment method, it is not necessary to heat the multilayer film under tension, so that even if the heat treatment time is relatively long, a large amount of processing is possible and productivity is not impaired.

In the present invention, the water vapor transmission rate measured under the conditions of a temperature of 40 ° C. and a relative humidity of 100% by heat treatment is 0.1 g / m 2 · day or less, preferably 0.08 g / m 2 · day or less, more preferably O Moisture-proof multilayer film which has a high moisture-proof performance of .O6g / m <2> * day or less can be obtained. In many cases, it is possible to obtain a moisture-proof multilayer film having a moisture permeability of 0.05 g / m 2 · day or less, most preferably from O 2 to O 4 g / m 2 · day. Since the moisture-proof degree of the PCTFE film measured on the same conditions is about 0.3g / m <2> / day, it turns out that according to this invention, the moisture-proof multilayer film which has a moisture-proof performance comparable to a PCTFE film can be obtained.

As the number of composite films in the multilayer film increases, the moisture permeability decreases, but according to the present invention, the following formula (1)

W≤ (1 / n) × 0.20 (1)

[Wherein n is the total number of layers of the vapor deposition film laminated adjacent to the adhesive layer, and W is the moisture permeability (unit = g / m 2 · day). ]

A moisture proof multilayer film which satisfies the relationship can be obtained. More specifically, for example, in the case of a multilayer film having a total number of layers of 2 (n = 2) of the deposited film stacked adjacent to the adhesive layer as shown in Fig. 1, the heat treatment results in 0.1Og / m 2. A breathability of less than one day can be achieved.

As a result of analyzing the experimental data on the relationship between the heat treatment temperature, the heat treatment time and the water vapor transmission rate, it was found that the following relational expression holds. That is, in order to make the water vapor transmission rate (W) of a multilayer film into (L / n) * 0.20g / m <2> * day or less, when T = heat treatment time (Hr) and t = heat treatment temperature (K), the following relational formula (I) It is preferable to heat-treat on conditions which satisfy | fill).

T≥3 × 10 ¹⁰ × ｔ ^-4.5184 (I)

That is, when the heat treatment temperature t (K) is set within the range of 55 ° C (328K) or more and less than 140 ° C (413K), the moisture permeability of the multilayer film is set to (1 / n) × 0.20 g / m 2 · day or less. The heat treatment is performed at the heat treatment temperature for at least T time (Hr).

In order to make the water vapor transmission rate of a multilayer film into (1 / n) * 0.1g / m <2> * day or less, it is preferable to heat-process on the conditions which satisfy | fill following relation (II).

T≥2 × 10 ¹¹ × ｔ ^-4.6651 (II)

In order to make the water vapor transmission rate of a multilayer film into (1 / n) * 0.12g / m <2> * day or less, it is preferable to heat-process on conditions which satisfy | fill following relation (III).

T≥3 × 10 ¹⁰ × t ^{-4, 1345} (III)

In addition, the power exponent of t in formula (I) is -4.5184, the power exponent of t in formula (II) is -4.6651, and the power exponent of t in formula (III) is -4.1345.

⑥ Use

The moisture proof multilayer film of this invention can be used as a packaging material or sealing material, such as food, a pharmaceutical, and an electronic component, utilizing the high moisture proof performance. The moisture-proof multilayer film of this invention can exhibit moisture-proofness comparable to a PCTFE film, and is especially suitable as a package film for sealing of an EL element main body.

The case where the moisture proof multilayer film of this invention is applied as a moisture proof material of an EL element main body is demonstrated with a specific example. 6 is a schematic cross-sectional view showing an example of an EL element. The EL element shown in FIG. 6 includes an EL element body formed by holding a light emitting layer 61 by a substrate 63 on which an electrode 62 is formed and a substrate 65 on which an electrode 64 is formed. It has a structure formed by sealing with a pair of moisture-proof materials 66 and 67. A lead wire is connected to the pair of electrodes 62 and 64, respectively, and is configured to apply an electric field to the light emitting layer 6l by feeding from an external power source. At least one of the substrates 63 and 65 is a transparent substrate such as a plastic film or a glass plate, so that light from the light emitting layer is transmitted to the outside. The electrodes 62 and 64 are formed of a metal oxide such as metal, ITO (indium-tin composite oxide), or the like, and at least one of them is made transparent so that light from the light emitting layer is transmitted to the outside. Therefore, when the board | substrate 63 and the electrode 62 are transparent, the other board | substrate 65 and the electrode 64 may be opaque, Furthermore, you may make a board | substrate and an electrode using aluminum foil etc. The EL element main body may be arranged in a plane or stacked vertically, and the plurality of EL element main bodies may be integrated and sealed with a moisture proof material.

Although at least one of the pair of moisture proof materials 66 and 67 is comprised by the moisture proof multilayer film of this invention, the other may be a glass substrate and a metal plate. For example, when one moisture proof material 67 is a glass substrate, the board | substrate 65 on it may be abbreviate | omitted and the electrode 64 may be formed on a glass substrate. When the pair of moisture proof materials 66 and 67 are the moisture proof multilayer films of this invention, two moisture proof multilayer films may be used, but one moisture proof film may be folded and used.

Fig. 7 is a cross-sectional schematic diagram showing another example of an EL element of the present invention. The EL element shown in Fig. 7 is provided between the transparent conductive film (ITO) 73 and the back electrode (aluminum foil) 76 on a light emitting layer 74 made of a powder phosphor hardened with an organic binder and one side thereof. It has a structure sandwiching the dielectric layer 75 for preventing dielectric breakdown. In the EL element of FIG. 7, the moisture absorbing films 72 and 77 for dehumidification are inserted and sealed by the moisture proof materials 71 and 78. As the moisture proof materials 71 and 78, when the moisture proof multilayer film of the present invention is used, a flexible EL device can be obtained.

An Example and a comparative example are given to the following, and this invention is demonstrated more concretely. In addition, the measuring method of a physical property is as follows.

(1) moisture permeability

The water vapor transmission rate was measured based on ASTM F-1249 (JIS K-7129B method) using the vapor permeability tester PERMATRAN-W3 / 31SW by a modern control company. Specifically, the flat multilayer film (test piece) to be measured is fixed to the diffusion cell, and the diffusion cell is placed between the drying chamber and the temperature control room by the test piece. In the atmosphere of 40 degreeC, the whole diffusion cell is made to make temperature of a test piece 40 degreeC by time progress. Before being interposed by the test piece, the drying chamber is exposed to dry nitrogen flow, and one of the thermostats is under nitrogen flow while being exposed to a relative humidity of 100% by a sponge containing distilled water. Since the relative humidity of a dry chamber becomes 0% and the relative humidity of a heating chamber becomes 100%, when the time of about 1 hour passes after both rooms are sandwiched by a test piece, the measurement of moisture permeability is started from that point. Water vapor that has permeated the drying chamber through the test piece is mixed with dry nitrogen (flow) and transferred to the infrared sensor. The infrared sensor measures the ratio of infrared energy absorbed by the water vapor and draws it out as an electrical signal, thereby calculating the moisture permeability. By this method, the water vapor transmission rate (unit = g / m <2> * day) on the conditions of 40 degreeC of temperature of a multilayer film, and 100% of a relative humidity is measured.

(2) Light emission luminance retention rate of EL element

After leaving the EL device sample for 500 hours under a condition of 60 ° C. and 90% relative humidity, the EL device sample was connected to a power source having an operating voltage of 100 V and an operating frequency of 400 Hz at room temperature, the initial emission luminance Lo was measured, and then a voltage was applied. while a measuring light emission luminance L ₁ after the lapse of 750 hours was cooled to room temperature, the following formula was calculated the light-emitting luminance sustain ratio.

Luminance luminance maintenance ratio = (L ₁ / Lo) * 100 (%)

(Example 1)

The moisture proof multilayer film which has the laminated constitution shown in FIG. 1 was produced. The laminated constitution of this multilayer film is as follows from the outer surface to the inner surface.

(1) Biaxially stretched polyethylene terephthalate film in which a deposition film of silicon oxide was formed ("tec barrier H" of Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 micrometers] (deposition film on the inner surface side),

(2) urethane adhesive layer (Toyo Morton Co., Ltd. product "AD-502 / CAT-10", thickness 3.5㎛),

(3) Biaxially stretched polyethylene terephthalate film in which the vapor deposition film of silicon oxide was formed ("tec barrier H" by Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 micrometers] (deposition film on the outer surface side).

Each layer was laminated | stacked through the urethane type adhesive bond layer by the dry lamination method, and the transparent multilayer film was obtained. The multilayer film was wound up into a roll shape. This multilayer film was aged at 40 ° C. for 72 hours. Subsequently, the multilayer film of the state which rewinded to roll shape was thrown into the heating furnace adjusted to 120 degreeC, hold | maintained for 140 hours, and heat-processed. The results are shown in Table 1.

(Comparative Example 1)

In Example 1, the multilayer film was similarly obtained except not having heat-processed after the aging process. The results are shown in Table 1.

(Example 2)

The moisture proof multilayer film which has the laminated constitution shown in FIG. 2 was produced. The laminated constitution of this multilayer film is as follows from the outer surface to the inner surface.

(1) biaxially stretched polyethylene terephthalate film having a silicon oxide deposited film ("tec barrier H", Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 µm) (deposited film on the inner surface),

(2) urethane adhesive layer (Toyo Morton Co., Ltd. product "AD-502 / CAT-10", thickness 3.5㎛),

(3) Biaxially stretched polyethylene terephthalate film in which a vapor deposition film of silicon oxide was formed ("tec barrier H" made by Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 micrometers] (deposition film on the outer surface),

(4) urethane adhesive layer [Toyo Morton Co., Ltd. product "AD-502 / CAT-10", thickness 3.5㎛),

(5) Biaxially stretched polyethylene terephthalate film with a silicon oxide vapor deposition film | membrane ("tec barrier H" by Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 micrometers] (deposition film on the outer surface side).

Each layer was laminated | stacked through the urethane type adhesive bond layer by the dry lamination method, and the transparent multilayer film was obtained. The multilayer film was wound up into a roll shape. This multilayer film was aged at 40 ° C. for 72 hours. Subsequently, the multilayer film of the state which rewinded to roll shape was put into the heating furnace adjusted to 10 degreeC, and it maintained for 250 hours, and heat-processed. The results are shown in Table 1.

(Comparative Example 2)

In Example 2, the multilayer film was similarly obtained except not having heat-processed after the aging process. The results are shown in Table 1.

(Example 3)

The moisture proof multilayer film which has a laminated constitution shown in FIG. 3 was produced. The laminated constitution of this multilayer film is as follows from the outer surface to the inner surface.

(1) biaxially stretched polyethylene terephthalate film having a silicon oxide deposited film ("tec barrier H", Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 µm) (deposited film on the inner surface),

(2) urethane adhesive layer (Toyo Morton Co., Ltd. product "AD-502 / CAT-10", thickness 3.5㎛),

(3) Biaxially stretched polyethylene terephthalate film in which a vapor deposition film of silicon oxide was formed ("tec barrier H" made by Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 micrometers] (deposition film on the outer surface),

(4) urethane adhesive layer [Toyo Morton Co., Ltd. product "AD-502 / CAT-10", thickness 3.5㎛),

(5) biaxially stretched polyethylene terephthalate film having a silicon oxide deposited film formed therein ("MOS-TH" manufactured by Oike Industry Co., Ltd., thickness of 12 µm) (deposited film on the inner surface side),

(6) urethane adhesive layer (Toyo Morton Co., Ltd. product "AD-502 / CAT-10", thickness 3.5㎛),

(7) A biaxially stretched polyethylene terephthalate film having a silicon oxide vapor deposition film formed thereon ("MOS-TH" manufactured by Oike Industries, Ltd., thickness 12 µm) (vapor deposition film on the outer surface side).

Each layer was laminated | stacked through the urethane type adhesive bond layer by the dry lamination method, and the transparent multilayer film was obtained. The multilayer film was wound up into a roll shape. This multilayer film was aged at 40 ° C. for 72 hours. Subsequently, the multilayer film of the state rewound in roll shape was thrown into the heating furnace adjusted to 110 degreeC, hold | maintained for 200 hours, and heat-processed. The results are shown in Table 1.

(Comparative Example 3)

In Example 3, the multilayer film was similarly obtained except not having heat-processed after the aging process. The results are shown in Table 1.

(Example 4)

The moisture proof multilayer film which has a laminated constitution shown in FIG. 4 was produced. The laminated constitution of this multilayer film is as follows from the outer surface to the inner surface.

(1) biaxially stretched polyethylene terephthalate film having a silicon oxide deposited film ("tec barrier H", Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 µm) (deposited film on the inner surface),

(2) urethane adhesive layer [Toyo Morton Co., Ltd. product "AD-578A / CAT-10", thickness 3.5㎛],

(3) biaxially stretched polyethylene terephthalate film having a silicon oxide deposited film ("tec barrier H" manufactured by Mitsubishi Kagaku Kyojin Co., Ltd., thickness 12 µm) (deposited film on the outer surface),

(4) urethane adhesive layer (Toyo Morton Co., Ltd. product "AD-578A / CAT-10", thickness 3.5㎛),

(5) Biaxially stretched polyethylene terephthalate film having a silicon oxide vapor deposition film formed therein ("Tec Barrier H" manufactured by Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 µm) (deposition film on the inner surface side),

(6) urethane adhesive layer (Toyo Morton Co., Ltd. product "AD-578A / CAT-10", thickness 3.5㎛),

(7) Biaxially stretched polyethylene terephthalate film with a silicon oxide vapor deposition film | membrane ("tec barrier H" by Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 micrometers] (deposition film on the outer surface).

Each layer was laminated | stacked through the urethane type adhesive bond layer by the dry lamination method, and the transparent multilayer film was obtained. The multilayer film was wound up into a roll shape. This multilayer film was aged at 40 ° C. for 72 hours. Subsequently, the multilayer film of the state which rewinded to roll shape was thrown into the heating furnace adjusted to 70 degreeC, hold | maintained for 800 hours, and heat-processed. The results are shown in Table l.

(Comparative Example 4)

In Example 4, the multilayer film was similarly obtained except not having heat-processed after the aging process. The results are shown in Table 1.

(Example 5)

The moisture proof multilayer film which has a laminated constitution shown in FIG. 5 was produced. The laminated constitution of this multilayer film is as follows from the outer surface to the inner surface.

(1) biaxially stretched polyethylene terephthalate film having a silicon oxide deposited film ("tec barrier H", Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 µm) (deposited film on the inner surface),

(2) urethane adhesive layer (Toyo Morton Co., Ltd. product "AD-502 / CAT-10", thickness 3.5㎛),

(3) biaxially stretched polyethylene terephthalate film having a silicon oxide deposited film ("tec barrier H" manufactured by Mitsubishi Kagaku Kyojin Co., Ltd., thickness 12 µm) (deposited film on the outer surface),

(4) urethane adhesive layer [Toyo Morton Co., Ltd. product "AD-502 / CAT-10", thickness 3.5㎛),

(5) Biaxially stretched polyethylene terephthalate film having a silicon oxide vapor deposition film formed therein ("Tec Barrier H" manufactured by Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 µm) (deposition film on the inner surface side),

(6) urethane adhesive layer (Toyo Morton Co., Ltd. product "AD-502 / CAT-10", thickness 3.5㎛),

(7) Biaxially stretched polyethylene terephthalate film with a silicon oxide vapor deposition film | membrane ("tec barrier H" by Mitsubishi Kagaku Kyojin Box Co., Ltd., thickness 12 micrometers] (deposition film on the outer surface).

Each layer was laminated | stacked through the urethane type adhesive bond layer by the dry lamination method, and the transparent multilayer film was obtained. The multilayer film was wound up into a roll shape. This multilayer film was aged at 40 ° C. for 72 hours. Subsequently, the multilayer film of the state rewound in roll shape is thrown into the heating furnace adjusted to 85 degreeC, hold | maintains for 400 hours, and heat processing is displayed. The results are shown in Table 1.

(Comparative Example 5)

In Example 4, the multilayer film was similarly obtained except not having heat-processed after the aging process. The results are shown in Table 1.

(Comparative Example 6)

Polychlorinated trifluoride ethylene film [PCTFE film; The water vapor transmission rate of "Nifutron NO4820" by Nitto Denko Corporation, thickness 200 micrometers] was measured. The results are shown in Table 1.

Layered Thickness (㎛) Deposition Film (Number of Layers) Aging treatment Heat treatment condition Water vapor permeability 40 ℃ 100% RH (g / ㎡day) Temperature (℃) Time (Hr) Temperature (℃) Time (Hr) Example 1 Figure 1 28 2 40 72 120 140 0.04 Example 2 Figure 2 44 3 40 72 100 250 0.03 Example 3 Figure 3 59 4 40 72 110 200 0.04 Example 4 Figure 4 59 4 40 72 70 800 0.03 Example 5 Figure 5 59 4 40 72 85 400 0.03 Comparative Example 1 Figure 1 28 2 40 72 - - 0.24 Comparative Example 2 Figure 2 44 3 40 72 - - 0.18 Comparative Example 3 Figure 3 59 4 40 72 - - 0.15 Comparative Example 4 Figure 4 59 4 40 72 - - 0.14 Comparative Example 5 Figure 5 59 4 40 72 - - 0.13 Comparative Example 6 PCTFE 200 - - - - - 0.03

As is apparent from the results in Table 1, the moisture-proof multilayer film of the present invention can achieve a water vapor transmission rate (40 ° C., 100% RH) of 0.03 to 0.04 g / m 2 · day. Indicates that it has performance.

(Examples 6-8, and Comparative Examples 7-16)

Using the multilayer film of the laminated constitution of Example 1, it operated like Example 1 except having performed heat processing on the heat processing conditions shown in Table 2 after an aging process. The results are shown in Table 2.

Layered Thickness (㎛) Deposition Film (Number of Layers) Aging treatment Heat treatment condition Water vapor permeability 40 ℃ 100% RH (g / ㎡day) Temperature (℃) Time (Hr) Temperature (℃) Time (Hr) Example 6 Figure 1 28 2 40 72 85 260 0.04 Example 7 Figure 1 28 2 40 72 85 470 0.04 Example 8 Figure 1 28 2 40 72 100 410 0.04 Comparative Example 7 Figure 1 28 2 40 72 150 0.2 0.28 Comparative Example 8 Figure 1 28 2 40 72 150 1.5 0.17 Comparative Example 9 Figure 1 28 2 40 72 150 6 0.27 Comparative Example 10 Figure 1 28 2 40 72 150 45 0.29 Comparative Example 11 Figure 1 28 2 40 72 150 100 0.60 Comparative Example 12 Figure 1 28 2 40 72 170 0.2 0.20 Comparative Example 13 Figure 1 28 2 40 72 170 0.6 0.72 Comparative Example 14 Figure 1 28 2 40 72 170 6 0.52 Comparative Example 15 Figure 1 28 2 40 72 170 21 0.63 Comparative Example 16 Figure 1 28 2 40 72 170 45 0.54

As is apparent from the results in Table 2, in the case of the moisture-proof multilayer film of the present invention (Examples 6 to 8), it is found that even if the heat treatment temperature and the heat treatment time are changed, high moisture resistance (low moisture permeability) can be achieved stably. Can be. On the other hand, when heat processing temperature is raised to 150 degreeC (Comparative Examples 7-11), it is difficult to fully lower a water vapor transmission rate, and also the nonuniformity arises in water vapor transmission rate by heat processing time. When the heat treatment temperature is increased to 170 ° C. (Comparative Examples 12 to 16), the moisture permeability is rather increased, and the non-uniformity in moisture permeability due to the heat treatment time is large.

(Example 9)

(Preparation of moisture-proof multilayer film)

Biaxially stretched polyethylene terephthalate film (with a urethane adhesive layer [Toyo Morton Co., Ltd. product "AD-502 / CAT-10", thickness of 3.5 µm) on the inner surface side of the multilayer film after heat treatment obtained in Example 5 ( The thickness of 16 micrometers) and the polyolefin-type hot melt type sealant layer (thickness 50 micrometers; "Hirodine 7589" by Hirody Co., Ltd.) were dry laminated at 65 degreeC, and the moisture-proof multilayer film which has a sealant layer in the innermost layer was produced.

(Preparation of main body of EL element)

Cyanoethyl polyvinyl alcohol, barium titanate powder, and N, N'-dimethylformamide were uniformly mixed to prepare an insulation paste. A powder phosphor in which Cu was added as an activator to cyanoethyl polyvinyl alcohol and ZnS and N, N'-dimethylformamide were uniformly mixed to prepare a light emitting layer paste. The insulating paste was screen-printed on the back electrode (thickness 70micrometer) which consists of aluminum foil, and the insulating layer (thickness 30micrometer) was formed, and the light emitting layer paste was screen-printed and the light emitting layer (thickness 40micrometer) was formed.

The transparent conductive film (75 micrometers in thickness) which formed the transparent evaporation film of ITO on the polyethylene terephthalate film was overlaid on the said light emitting layer, and it was heat-compression-bonded by the roll laminator. The electrode lead wire was derived from the back electrode and the ITO layer on a transparent conductive film. The hygroscopic film (thickness 75 mu m) made of nylon was coated on both surfaces of the EL element thus produced via an adhesive layer (ethylene-vinyl acetate copolymer, 30 mu m thickness) to obtain an EL element main body.

(Production of EL element)

The two moisture-proof multilayer films prepared above are opposed to each other in terms of the polyolefin-based hot melt sealant layer, and the EL element body prepared above is placed therebetween, heat-compression-bonded at 140 ° C, and the periphery of the EL element main body. The electroluminescent EL element which seal | sticked with the moisture proof multilayer film was produced. The light emission luminance retention of this EL element was 75%.

According to this invention, the moisture proof multilayer film which consists of a non-hygroscopic resin layer in which the vapor deposition film of an inorganic oxide or the metal was formed, and shows the high moisture proof performance is provided, and its manufacturing method is provided. The moisture proof multilayer film of this invention is suitable as packaging materials and sealing materials, such as a foodstuff, a medicine, and an electronic component. The moisture proof multilayer film of the present invention can exhibit moisture resistance comparable to a polychlorinated trifluoride ethylene film, and is particularly suitable as a package film for sealing electronic components such as an electroluminescent device.

Claims (10)

In the moisture proof multilayer film containing the composite film in which the vapor deposition film of the inorganic oxide was formed in at least one surface of the non-hygroscopic resin layer, (1) The total number of layers of the deposition film in which the deposited film surface of the composite film is laminated with another non-hygroscopic resin layer surface or the deposition film surface of another composite film via the adhesive layer, and laminated adjacent to the adhesive layer ( a step of producing a multilayer film having n) of 2 to 8, and then (2) the multilayer film is prepared by a process of heat-treating for at least 100 hours in a dry heat atmosphere at 55 ° C. or more and less than 140 ° C., The water vapor transmission rate (W; unit = g / m 2 ㆍ day) measured under the temperature of 40 degreeC and the relative humidity of 100% is following formula (1). W≤ (1 / n) × 0.20 (1) Moisture-proof multilayer film, characterized in that to satisfy the relationship. The moisture-proof moisture-proof multilayer film of Claim 1 containing 2 or more composite films in which the vapor deposition film of an inorganic oxide was formed in at least one surface of a non-hygroscopic resin layer. 3. The at least one composite film having an inorganic oxide deposited film formed on at least one surface of the non-hygroscopic resin layer, wherein at least two of them are laminated with each other on the deposited film surfaces via an adhesive layer. Moisture-proof multilayer film which has a laminated constitution. In the manufacturing method of the moisture proof multilayer film containing the composite film in which the vapor deposition film of inorganic oxide was formed in at least one surface of the non-hygroscopic resin layer, (1) The total number of layers of the deposition film in which the deposited film surface of the composite film is laminated with another non-hygroscopic resin layer surface or the deposition film surface of another composite film via the adhesive layer, and laminated adjacent to the adhesive layer ( a step of producing a multilayer film having n) of 2 to 8, and then (2) A method for producing a moisture resistant multilayer film, comprising the step of heat-treating the multilayer film in a dry heat atmosphere at 55 ° C. or more and less than 140 ° C. for at least 100 hours. The moisture permeability (W; unit = g / m 2 · day) measured by the heat treatment in the step (2) under the condition of temperature 40 ° C. and relative humidity of 100% according to claim 4  W≤ (l / n) × 0.20 (1) A method for producing a moisture resistant multilayer film, comprising obtaining a multilayer film that satisfies the relationship. The multilayer film according to claim 4 or 5, wherein in the step (1), a multilayer film containing at least two composite films having an inorganic oxide vapor deposition film formed on at least one side of the non-hygroscopic resin layer is produced. Method for producing a moisture resistant multilayer film. The said process (1) WHEREIN: Two or more composite films in which the vapor deposition film of an inorganic oxide was formed in at least one surface of a non-hygroscopic resin layer, In addition, at least two of them interpose an adhesive layer. To produce a multilayer film having a layer structure in which the vapor deposition film surfaces are laminated to each other. The process for producing a moisture resistant multilayer film according to claim 4 or 5, wherein in the step (2), the multilayer film is heat treated under non-tension. The method for producing a moisture resistant multilayered palm according to claim 8, wherein the multilayer film is heat-treated in a state in which the multilayer film is wound into a roll shape. The said process (1) WHEREIN: The multilayer film is produced using a urethane type adhesive agent for an adhesive bond layer, Then, the aging process of an adhesive agent is 24 hours or more in the temperature range of 30-50 degreeC. After carrying out, the heat treatment of the step (2) is carried out.

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