JP2014030958A - Moisture prevention film and electric/electronic apparatuses - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture prevention film capable of securely performing an originally-intended function while realizing thinning/weight-saving with simple configuration, to realize efficient production of an electric/electronic apparatus utilizing the moisture prevention film through improving mechanical strength and positioning property at adhesion operation, and to provide such electric/electronic apparatuses with stable or higher quality.SOLUTION: The moisture prevention film comprises a laminate including: an aluminum layer; and a first protective layer and a second protective layer laminated on upper and lower sides of the aluminum layer, respectively, and having the same tensile modulus of elasticity. Thickness of the laminate is 50 μm or lower, and thickness of the aluminum layer is 20 μm or lower.

Description

  The present invention relates to a moisture-proof film and electrical / electronic devices.

Conventionally, in order to prevent water vapor from entering a laminated structure constituting an electronic device such as a liquid crystal display panel, the functionality of a moisture-proof film or the like on the upper and / or lower surface of such a laminated structure is known. A film is disposed (for example, Patent Document 1).
However, with recent demands for thinning and weight reduction of these electronic devices, each layer constituting the laminated structure and its laminated structure, and further thinning / lightening of functional films laminated on the upper and lower surfaces thereof, etc. Is eager.
In particular, when a flexible substrate made of plastic or the like is used as a substrate constituting an electronic device such as an electronic paper or a mobile terminal, the moisture-proofing action is high because the moisture-proofing property is extremely low due to the characteristics of the material, and There is a strong demand to develop a moisture-proof film that is thin and lightweight.
As such a moisture-proof film, for example, a film having a laminated structure of PET film / aluminum layer / resin layer / adhesive layer has been proposed.

And with the explosive spread of such electronic devices, the original functions are surely performed to maintain the quality of the electronic devices, and the mechanical strength and handling properties are improved, so that more efficient productivity is achieved. Development of functional films that can be realized is required.
For example, when a moisture-proof film is bonded to a flexible drive board of an electronic device, the moisture-proof film has a flexibility that can follow unevenness like the circuit surface of the drive board, and such follow-up is possible. However, breakage due to bending of the aluminum layer that imparts moisture-proof performance is less likely to occur, and due to changes in temperature and pressure or load in the manufacturing process of the electronic device after bonding the moisture-proof film, alteration and deformation do not occur, It is necessary to provide mechanical strength and handling properties that can perform the original function, and alignment characteristics during the pasting operation. In particular, it is necessary to protect the aluminum layer in order for the breakage of the aluminum layer and the like to immediately cause a decrease in moisture-proof characteristics.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a moisture-proof film capable of reliably fulfilling the originally intended function, a mechanical strength and handling while realizing a thin film / light weight with a simple configuration. By improving the properties and alignment characteristics at the time of pasting work, it is possible to efficiently manufacture electrical and electronic equipment using this moisture barrier film, and to maintain quality or high quality electrical and electronic equipment. The purpose is to provide.

The present invention includes the following inventions.
(1) an aluminum layer;
A laminate comprising a first protective layer and a second protective layer, which are laminated above and below the aluminum layer and have the same tensile elastic modulus,
The laminate is a moisture-proof film having a thickness of 50 μm or less and the aluminum layer having a thickness of 20 μm or less.
(2) The moisture-proof film described above, wherein the first protective layer and the second protective layer are layers formed of the same material.
(3) The moisture-proof film according to any one of the above, wherein the first protective layer and the second protective layer are layers formed with the same thickness.
(4) The moisture-proof film according to any one of the above, wherein each of the first protective layer and the second protective layer has a tensile elastic modulus of 1 GPa or more.
(5) The moisture-proof film according to any one of the above, wherein each of the first protective layer and the second protective layer has a thickness of 80 to 150% of the aluminum layer.
(6) An adhesive layer is further provided on the surface of the second protective layer opposite to the aluminum layer,
Any one of the above moisture-proof films in which the adhesive layer satisfies a wettability of 70% or more as defined below.
Wetability: When the adhesive layer of the moisture-proof film is bonded to the adherend with one reciprocating load with a 2 kg hand roller, the moisture-proof film and the adherend are lifted upside down after a predetermined time and turned upside down once. The ratio of the adhesion area of the moisture-proof film and the adherend to the total area of the moisture-proof film.
(7) An adhesive layer is further provided on the surface of the second protective layer opposite to the aluminum layer,
Any one of the above moisture-proof films, wherein the adhesive layer is made of an adhesive containing a styrene-based thermoplastic elastomer as a base material.
(8) The moisture-proof film according to any one of the above, wherein the adhesive layer is made of an adhesive containing a styrene / ethylene butylene / styrene block copolymer as a base material.
(9) The moisture-proof film according to any one of the above, wherein the adhesive layer is made of an adhesive containing, as a base material, a styrene / ethylene butylene / styrene block copolymer having a styrene content of 15% by weight or more.
(10) The moisture-proof film according to any one of the above, wherein the adhesive layer is made of an adhesive containing a modified styrene / ethylene butylene / styrene block copolymer as a base material.
(11) The moisture-proof film according to any one of the above, wherein the modified styrene / ethylene butylene / styrene block copolymer is an unmodified product or an amino-modified product.
(12) The moisture-proof film according to any one of the above, wherein the adhesive layer has an adhesive force of 1 N / 20 mm or less.
(13) The moisture-proof film according to any one of the above, wherein the adhesive layer has a property of being ten times or more larger than the adhesive force before heating by heating the moisture-proof film.
(14) The moisture-proof film according to any one of the above, wherein the adhesive layer has an adhesive force of 3 N / 20 mm or more by heating the moisture-proof film.
(15) Electric / electronic devices including any one of the above moisture-proof films.

According to the moisture-proof film of the present invention, while realizing a thin film / light weight with a simple configuration, it is possible to surely achieve the moisture-proof action which is the original intended function, as well as good mechanical strength and handling properties. It is. Therefore, it is possible to provide a moisture-proof film that can realize efficient manufacture of an electronic device using this.
Further, by using this moisture-proof film, it is possible to provide electrical / electronic devices that are excellent in moisture-proof performance and can maintain high quality.

The moisture-proof film of the present invention is mainly composed of a laminate including an aluminum layer, a first protective film, and a second protective film.
It is preferable that the moisture-proof film further includes an adhesive layer on the laminate.

(Aluminum layer)
The aluminum layer is a layer imparting a function of preventing permeation of water vapor, for example, less than 5 × 10 ⁻² g / m ² · 24 h, preferably 1 × 10 ⁻² g / m ² · 24 h or less, and more preferably Can achieve water vapor transmission of 5 × 10 ⁻³ g / m ² · 24 h or less. The moisture-proof property can be a value measured under the conditions of 40 ° C. and RH 90% using, for example, PERMATRAN W3 / 33 (manufactured by MOCON) as a measuring device by MOCON method (JIS K 7126).

The aluminum layer imparts such a moisture-proof function, and as described above, the aluminum layer is set to a thickness that does not hinder or reduce this function even through a manufacturing process of a moisture-proof film, an electronic device, or the like. Specifically, in consideration of the balance between these characteristics and thin film / lightening, about 20 μm or less can be mentioned, preferably about several μm to 20 μm, about several μm to about tens of μm, about 4 μm to 15 μm, About 4 μm to 12 μm, about 4 μm to 10 μm, and about 5 μm to 9 μm are more preferable.
The aluminum layer may be formed into a layer using aluminum or an alloy thereof, for example, using a deposition method or a sputtering method, or by a method known in the art such as rolling with a rolling mill. It can be formed in a foil shape.

(First protective film and second protective film)
The first protective film and the second protective film constituting the moisture-proof film are stacked above and below the aluminum layer. If such a laminated relationship can be realized, the first protective film and the second protective film may be in direct contact with the aluminum layer, or the first protective film and the second protective film are in close contact with the aluminum layer. In order to realize this, an undercoat layer of a so-called undercoat as described later may be interposed.

The first protective layer and the second protective layer preferably have the same tensile elastic modulus.
Here, the tensile elastic modulus means that the film-like first protective layer and the second protective layer are cut into strips each having a length of 100 mm and a width of 5 mm, and the cut-out film is subjected to a distance between chucks of 50 mm in an atmosphere at 23 ° C. Then, a tensile test was performed with a tensile tester (manufactured by Shimadzu Corporation, Autograph AG-IS type) under the condition of a tensile speed of 300 mm / min to obtain a stress-strain curve. A value obtained by drawing a tangent line at the initial rising portion and dividing the tensile strength when the tangent line corresponds to 100% elongation by the cross-sectional area of the film.
The value of the tensile elastic modulus is not particularly limited as long as the first protective layer and the second protective layer are the same, but for example, 1 GPa or more is preferable, and 2 GPa or more is more preferable. By setting such a tensile elastic modulus, the rigidity of each of the first protective layer and the second protective layer is increased, and the above-described ultrathin aluminum layer can be reliably protected, and various manufacturing processes (for example, In addition, it is possible to effectively prevent bending, wrinkle, breakage, deformation, etc. by the load of pressure and / or temperature in the lamination / bonding of the aluminum layer to the first protective film, etc., the punching process of the moisture-proof film, etc. Mechanical strength can be imparted to the moisture-proof film itself. As a result, the handling property of the moisture-proof film can be improved.

  The first protective layer and the second protective layer are preferably layers formed of the same material as each other, and thermoplastic resins such as polyester (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), and the like. Polyester film, aromatic polyimide film such as polyimide (PI), polyolefin film such as polypropylene (PP), polystyrene, and the like can be used. These materials may be used alone or in combination of two or more, and may have a laminated structure of two or more layers, but is preferably a single layer. Especially, as above-mentioned, what has a tensile elasticity modulus mentioned above is preferable. Specifically, PET, PP, polystyrene and the like are preferable, and PET and PP are more preferable.

The first protective layer and the second protective layer each preferably have a thickness of 80 to 150% of the aluminum layer. For example, each of the first protective layer and the second protective layer is preferably about 20 μm or less, more preferably about 15 μm or less, and more preferably about 10 μm or less. Even more preferred. Moreover, about 5 micrometers or more and about 7 micrometers or more are preferable. By setting it in such a range, the aluminum layer can be sufficiently protected, and in the state of the thin film moisture-proof film, breakage of the ultra-thin aluminum layer can be prevented. Strength and handleability can be secured.
In particular, the first protective layer and the second protective layer are preferably layers formed with the same thickness. Thereby, when pressure etc. are loaded to a moisture-proof film | membrane, the intensity | strength in the upper and lower sides of an aluminum layer can be balanced and the fracture | rupture of an aluminum layer etc. can be prevented reliably.
The total thickness of the laminate in which the first protective layer and the second protective layer are laminated on the upper and lower sides of the aluminum layer is preferably about 50 μm or less, more preferably about 45 μm or less, about 40 μm or less, or 35 μm. More preferably, it is more preferably about 30 μm or less.

The first protective layer and the second protective layer are preliminarily used on the surface to be bonded to the aluminum layer, for example, mat treatment, corona discharge treatment, primer treatment, coating treatment with a primer, crosslinking treatment, chromic acid treatment, Chemical or physical treatments such as ozone exposure, flame exposure, high piezoelectric impact exposure, and ionizing radiation treatment may be performed. Especially, it is preferable to form the coating layer by a primer.
As the coating layer, for example, those known in the art such as urethane, ester, acrylic and isocyanate can be used.

  In the case of performing the coating treatment, in consideration of the above-described moisture-proof film, thin films such as electric and electronic devices, and weight reduction, for example, the thickness is preferably about several μm or less, and more preferably about 2 μm or less. Preferably, the thickness is about 1 μm or less. The undercoat layer is preferably formed between the aluminum layer and the first protective layer and between the aluminum layer and the second protective layer. For example, as described above, the aluminum layer is In the case of forming by a vapor deposition method, a sputtering method, etc., an aluminum layer is formed on one of the first protective layer and the second protective layer as a base material, and the aluminum layer is formed on the surface of the obtained aluminum layer. A coating layer may be formed and the other of the first protective film and the second protective film may be bonded together.

  The first protective film and the second protective film can be formed by a known film forming method, for example, a wet casting method, an inflation method, a T-die extrusion method, or the like. These may be non-stretched or may be uniaxial or biaxially stretched.

  As a method of forming a laminate having an aluminum layer, a first protective film, and a second protective film, as described above, each layer is formed into a film shape by a known method, and dry lamination is performed by forming the above-described undercoat layer. Various methods can be used such as an aluminum layer formed in close contact with the first protective film and a second protective film formed thereon by dry lamination or extrusion lamination.

  In particular, in the moisture-proof film of the present invention, when the first protective film and the second protective film have the same tensile elastic modulus and are made of the same material with the same film thickness, each of them is 1 GPa or more. When it is made of a material having a tensile elastic modulus, and when each is formed of a film having the same or slightly thicker thickness as the aluminum layer, the laminated body as a whole is 1 GPa or more (preferably 1. 5GPa or more, more preferably 1.8GPa or more), the thin film aluminum layer can be more reliably broken, protected from wrinkles and breakage. Even when exposed to various harsh conditions, or exposed to long-term harsh environments during use, the characteristics as a moisture barrier film are reliably maintained Door can be.

(Adhesive layer)
In general, a moisture-proof film having very high moisture-proof properties as in the present invention is used in close contact with an object intended to be moisture-proof (hereinafter sometimes referred to as an “adherent”).
Accordingly, the moisture-proof film of the present invention preferably includes an adhesive layer on the surface of the second protective film on the side opposite to the aluminum layer in order to adhere to the members constituting these electric / electronic devices.

The adhesive layer is not particularly limited as long as it is composed of an adhesive that can ensure adhesion to the adherend, and use an adhesive and a pressure-sensitive adhesive known in the art. Can do. In particular, when the adherend has irregularities, it is preferable that the adherend has flexibility so as to follow the irregularities satisfactorily.
Further, those having a hot melt action, that is, those having a characteristic of maintaining a predetermined shape at normal temperature, melting by heating, and fixing and adhering by cooling are preferable. The heating here can be appropriately determined depending on the materials constituting the first protective layer, the second protective layer, the adherend, and the like, and includes about 80 to 150 ° C.

  The adhesive layer preferably has wettability. Here, wettability is a form of a moisture-proof film, and when an adhesive layer is bonded to an adherend, no other adhesive / adhesive is used, and further pressure and / or heat is applied. In addition, it means the property that the adhesion to the adherend can be maintained by the weight of the moisture-proof film. The wettability is, for example, a value measured by the method described in detail in the examples, for example, an adhesive layer of a moisture-proof film is bonded to an adherend with a reciprocating load with a 2 kg hand roller, and after a predetermined time. This means the ratio (%) of the adhesion area between the moisture-proof film and the adherend relative to the total area of the moisture-proof film when the moisture-proof film and the adherend are lifted and inverted once. Accordingly, the adhesive layer preferably satisfies 70% or more, more preferably 75% or more, and more preferably 80% or more or more than 85% as the wettability expressed as described above. More preferably. By setting it as this range, it is possible to satisfy the alignment property of the moisture-proof film to the adherend, even though it is a very thin adhesive layer and moisture-proof film.

  Therefore, it is preferable that the adhesive layer has a fine adhesive force of 1 N / 20 mm or less, for example. Here, the adhesion force means an adhesion force in a state in which a laminated structure of a first protective layer / aluminum layer / second protective layer / adhesive is formed as a moisture-proof film and is not bonded to an adherend. (Hereinafter, it may be referred to as “initial adhesive strength” or “adhesive strength before heating”) In other words, it means an adhesive force in a state in which a predetermined shape is maintained at normal temperature, a state before melting by heating, or a state before fixing and bonding by cooling before bonding by hot melt action.

By providing such a fine adhesive force, when the alignment is performed on the adherend, the arrangement at the appropriate position is not easily released, and the handleability is greatly improved. In addition, it can be maintained in place without causing wrinkles, bubbles, bending, etc., and temporary fixing can be surely performed until the original fixing. Furthermore, when a deviation is found in the alignment, the moisture-proof film can be easily peeled even when the moisture-proof film is bonded to another position, and the reworkability can be improved.
That is, when the adhesive strength of the adhesive layer has so-called strong adhesive strength, reworkability cannot be ensured, and wrinkles, bends, etc. easily occur, leading to a decrease in moisture resistance. This moisture-proof film can be avoided.

In addition to having the initial adhesive force described above, the adhesive has an adhesive force when the moisture-proof film is fixed to the adherend, that is, the moisture-proof film is heated, and the adhesive is melted by the hot melt action. It is preferable that the adhesive strength after solidification has a strong adhesive property that makes it ten times or more the initial adhesive strength. Specifically, several N / 20mm or more, 3N / 20mm or more, 6N / 20mm or more are mentioned, and 10N / 20mm or more and several tens N / 20mm or more are preferable. In particular, when the moisture-proof film and the adhesive layer are significantly thinned, for example, as described later, even if the adhesive layer is a thin film having a thickness of about 50 μm or less and less than about 30 μm, sufficient adhesive strength is provided. Are preferred.
By providing such a large adhesive force, adhesion of the moisture-proof film to the adherend can be realized. In particular, in the manufacturing / processing steps of the adherend after the moisture-proof film is fixed to the adherend, the original function of the moisture-proof film is ensured without the moisture-proof film being peeled off from the adherend even at the end that is most likely to peel off. Can be accomplished.

As such an adhesive, a conventionally known pressure-sensitive adhesive or pressure-sensitive adhesive such as a pressure-sensitive adhesive can be used. For example, it is preferable that a thermoplastic resin or rubber is contained as a base material and is solvent-free. As a base material constituting such an adhesive,
For example, rubber polymers such as natural rubber, polyisobutylene rubber, styrene / butadiene rubber, styrene / isoprene / styrene block copolymer rubber, recycled rubber, butyl rubber, polyisobutylene rubber, NBR, and styrene thermoplastic elastomer are used as the base polymer. Examples thereof include rubber-based pressure-sensitive adhesives; silicone-based pressure-sensitive adhesives; acrylic pressure-sensitive adhesives and urethane-based pressure-sensitive adhesives. You may use these individually or in combination of 2 or more types.

  Of these, styrenic thermoplastic elastomers are preferred. By using such a base material, the adhesive protrudes from the moisture-proof film by heating or by pressing at the time of heating, and contamination of the adhesive to a site (for example, a sticking roll) that is not intended to be bonded. Can be kept to a minimum. In addition, even with an extremely thin film shape, it is possible to ensure unevenness followability. Usually, in order to attach the moisture-proof film to the adherend, heating / pressure load is gradually applied over a predetermined time. In particular, in order to increase the productivity of the final product, the moisture-proof film is attached to the adherend. It is required to perform the laminating process at a high speed, and for this reason, heating is performed rapidly and at a high temperature. Even in such a case, the rapid softening with respect to the high temperature is suppressed, and the rapid heating and the high temperature are performed. It is possible to effectively prevent the protrusions from being heated by heating.

Examples of the styrenic thermoplastic elastomer include a polymer composed of a block segment composed of a styrene monomer unit and a rubber monomer unit.
The styrenic thermoplastic elastomer may not be a hydrogenated product, but is preferably a hydrogenated product. Examples of such styrenic thermoplastic elastomers include SIS, SBS, SEBS, SEPS, SI, SB, and SEP. Of these, SEBS and SEPS are preferable. For example, when SEBS is used, the weight average molecular weight is, for example, about 20,000 to 500,000.

Examples of the styrenic thermoplastic elastomer include the following.
Polystyrene-poly (ethylene / propylene) block polystyrene-poly (ethylene / propylene) block-polystyrene polystyrene-poly (ethylene / butylene) block-polystyrene polystyrene-poly (ethylene-ethylene / propylene) block-polystyrene polystyrene-poly (ethylene / Propylene) block polystyrene-poly (ethylene / propylene) block-polystyrene polystyrene-poly (ethylene / butylene) block-polystyrene polystyrene-poly (ethylene-ethylene / propylene) block-polystyrene polystyrene-poly (ethylene / propylene) block polystyrene-poly (Ethylene / propylene) block-polystyrene polystyrene-poly (ethylene / butylene) block-polystyrene Polystyrene-poly (ethylene-ethylene / propylene) block-polystyrene polystyrene-poly (ethylene / propylene) block polystyrene-poly (ethylene / propylene) block-polystyrene polystyrene-poly (ethylene / butylene) block-polystyrene polystyrene-poly (ethylene- Ethylene / propylene) block-polystyrene polystyrene-poly (isoprene) block polystyrene-poly (isoprene) block-polystyrene polystyrene-poly (ethylene / isoprene) block polystyrene-poly (ethylene / isoprene) block-polystyrene polystyrene-poly (butadiene) Block-polystyrene polystyrene-poly (butadiene / butylene) block-polystyrene Tylene-poly (ethylene / butylene) block-polystyrene is preferred.
For example, as such a styrenic thermoplastic elastomer, commercially available products such as Tough Tech series made by Asahi Kasei and Kraton series made by Kraton polymer can be used.

The styrenic thermoplastic elastomer may be unmodified, but a modified product, particularly a modified product with an amine, an amide or the like is preferred. The modification rate in this case may be, for example, about 10% by weight or less, preferably 5% by weight or less, and more preferably about several% by weight.
As described above, by modifying the modified product with an amine, amide or the like instead of an acid, the wettability of the styrenic thermoplastic elastomer itself can be appropriately adjusted, and the moisture-proof film of the present invention can be used for a circuit board or the like. Even if it is directly bonded, it is possible to avoid adverse effects on the electric circuit and the like, and to have excellent adaptability to the above-described electric and electronic devices.

The styrene thermoplastic elastomer preferably has a styrene content of about 15% by weight or more, more preferably about 18% by weight or more, more preferably about 20% by weight or more, and about 30% by weight or more. Is even more preferable. Thereby, moderate initial fine adhesiveness can be given.
The hydrogenated styrenic thermoplastic elastomer preferably has an MFR of greater than 4.0 g / 10 minutes, more preferably 5.0 g / 10 minutes or more. MFR here is a value measured at 230 ° C. and 6.16 kgf in accordance with ISO 1133. By having such MFR, it is possible to realize appropriate initial fine adhesion and increased adhesion by heating.

  In the adhesive layer of the moisture-proof film of the present invention, it is preferable that the above-mentioned styrenic thermoplastic elastomer is contained as a base material, that is, about 10 to 99% by weight with respect to the total weight of the adhesive layer. About 20 to 95% by weight is more preferable, and about 30 to 85% by weight is more preferable.

Adhesives can be added to the above-described base material, additives known in the art, such as crosslinking agents, plasticizers, pigments, dyes, antioxidants, anti-aging agents, fillers, ultraviolet absorbers, antistatic agents, softening agents. One or more agents, curing agents, light stabilizers, polymerization initiators and / or anti-electromagnetic wave agents may be contained. The content of the additive can be appropriately adjusted according to its characteristics and the like.
As the crosslinking agent, for example, Coronate HL (hexamethylene diisocyanate HDI-TMP adduct) manufactured by Nippon Polyurethane Industry, or BXX5134 (aziridine-based curing agent) manufactured by Toyo Ink Co., Ltd. can be used.
Examples of the plasticizer include naphthenic oil or paraffin oil.
As the antistatic agent, for example, Elegan 264wax manufactured by NOF Corporation can be used.

  When laminating the adhesive layer on the laminate, a method is usually used in which the composition containing the above-described components is melted and applied to the surface of the second protective layer opposite to the aluminum layer. As a coating method in this case, a method using a Mayer bar, an applicator, or the like, or a method for industrial mass production using a phantom die, a gravure coater, a roll coater, or the like is known depending on a desired thickness. The method can be selected as appropriate. Alternatively, an adhesive may be applied on an appropriate release liner (separator) to form an adhesive layer, which may be transferred (transferred) onto the second protective film. In the case of forming by transfer, by applying a heating and pressurizing process such as an autoclave process after the transfer to the laminate, the voids (voids) generated at the interface between the laminate and the adhesive layer are diffused and eliminated. be able to.

The thickness of the adhesive layer is, for example, about 50 μm or less, preferably about 30 μm or less, more preferably about 28 μm or less in consideration of the thin film / weight reduction of the moisture-proof film. With such a thin adhesive layer, even when applied to the above-described laminate of moisture-proof films, the moisture-proof film itself can be reduced in thickness / weight. In particular, when the total thickness of the moisture-proof film is about 50 μm or less in the combination of the adhesive layer and the above-described laminate, the effect of the present invention can be exhibited to the maximum.
Moreover, when using the specific material mentioned above, even if it is a thin film form, it can provide uneven | corrugated followability and the adhesiveness to a laminated body, and also ensures the workability (punching etc.) of a moisture-proof film. It becomes possible.

  The moisture-proof film may optionally have a release liner laminated on the surface of the adhesive layer. In other words, the adhesive layer surface may be covered before use such as when the adhesive layer is stored, and a layer that is peeled off to expose the adhesive layer surface may be laminated when the adhesive layer is bonded to the adherend surface. As the release liner, for example, silicone-treated PET, silicone-treated paper base material, polyolefin and the like can be used, and it is preferable to laminate the silicone treatment of the silicone-treated PET so as to contact the adhesive layer.

(Electronic and electronic equipment)
Examples of the object that can impart moisture-proof properties using the moisture-proof film of the present invention include organic EL / liquid crystal panels, indicators, various keypads, and / or electronic circuits. Specifically, electric / electronic devices such as electronic paper, mobile phones, mobile terminals, smart cards, disaster prevention devices, E-tags, signs / digital signs, and medical devices can be used. In addition, such electric / electronic devices include devices including a member that generates an electrochemical reaction that requires moisture-proof properties, such as a lithium ion battery.

Below, the moisture-proof film | membrane of this invention is demonstrated in detail based on an Example.
In Examples and Comparative Examples, parts and% are based on weight unless otherwise specified.

[Preparation of substrate]
Base material 1
First, an aluminum foil (thickness: 7 μm) of approximately 100 wt% aluminum was prepared as an aluminum layer.
A PET film (thickness: 9 μm) was prepared as the first protective layer and the second protective layer.
As the primer, a polyisocyanate-based primer (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name “Coronate L”) was prepared.
Using these materials, as shown in Table 1 below, PET / undercoat layer / aluminum layer / undercoat layer / PET were laminated in this order, and substrate 1 was produced by dry lamination.

Substrates 2-4
As the first protective layer and the second protective layer, a PET film (thickness: 9 μm), a PP film (thickness: 9 μm), and a PE film (thickness: 9 μm) are prepared. Similarly, the base materials 2-4 were produced.

(Evaluation of moisture resistance)
Each base material was produced on a roll-to-roll line, and 20 square samples each having a side of 15 cm were sampled every 10 m.
These moisture-proof properties were measured by the MOCON method (JIS K 7126) under the following conditions.
Measuring device: PERMATRAN W3 / 33 (manufactured by MOCON)
Environmental conditions: 40 ° C., RH 90%.
When the value of the water vapor transmission rate was less than 5.0 × 10 ⁻² g / m ² · 24 h, the product was judged as non-defective, and when it was higher than this, the total good product rate was calculated as defective. The results are shown in Table 1.

(Tensile modulus)
The base materials 1 to 4 were cut into strips each having a length of 100 mm and a width of 5 mm, and the cut base materials were subjected to a tensile tester (Shimadzu Corporation) in a 23 ° C. atmosphere at a chuck distance of 50 mm and a tensile speed of 300 mm / min. A tensile test was performed using an autograph AG-IS type manufactured by Co., Ltd. And, by drawing a tangent to the initial rising part of the stress-strain curve obtained here and dividing the tensile strength when the tangent corresponds to 100% elongation by the cross-sectional area of the base material, the tensile modulus is obtained. Calculated. About each base material, the tensile elasticity modulus of the TD / MD direction was measured and the low value was shown in Table 1 among TD / MD directions.

表２において、折れ曲がりの発生とは、各基材をロール−トゥ−ロールのラインにて作製した際に折れ曲がりが発生しているどうかを観察した場合の発生状況を示す。折れ曲りの発生は、防湿性良品率と密接に関係する。つまり、防湿性良品率100％ということは、折れ曲りは発生していない。また、防湿性良品率が60％ということは、折れ曲がりが多少発生しており、５０％ということは、折れ曲がり画発生していることを示す。

In Table 2, the occurrence of bending refers to the state of occurrence when bending is observed when each substrate is produced on a roll-to-roll line. The occurrence of bending is closely related to the moisture-proof non-defective rate. In other words, 100% moisture-proof non-defective rate does not cause bending. Further, when the moisture-proof non-defective rate is 60%, some bending is generated, and 50% indicates that a bent image is generated.

(Production of moisture barrier film)
Moisture-proof film 1-5
As adhesives, various base materials shown in Table 2 were dissolved in a toluene diluted solution so as to have a solid concentration of 20% to prepare a resin solution. The obtained resin solution was applied to the substrate 1. Then, it dried at 110 degreeC for 5 minute (s), and finally obtained the moisture-proof film | membrane (total film thickness: 52 micrometers) which has a 25-micrometer-thick adhesive layer.
On the surface of the adhesive layer, a treated surface of a PET separator subjected to a silicone lightening treatment was bonded.

Moisture barrier 6
As an adhesive, an EVA adhesive (Evaflex EV550, manufactured by Mitsui DuPont Polychemical Co., Ltd.) was used, and this adhesive was melted and bonded to the obtained base material by an extrusion laminating method.
A PET separator was bonded to the surface of the adhesive layer in the same manner as described above.

The following evaluation was performed about the obtained moisture-proof film. The results are shown in Table 2.
(Wettability)
A 20 mm wide moisture-proof film was bonded to a 50 μm-thick 50 μm-thick polyimide film (Toray DuPont Kapton 200V) by one reciprocation using a 2 kg hand roller.
Twenty of these samples were made.
After 1 minute of bonding, the polyimide film was lifted, the bonded sample was reversed, and the cycle of returning it again was performed once.
After this cycle, those having a remaining contact area of 95% or more between the moisture-proof film and the polyimide film were regarded as having good wettability, and the yield rate was calculated.

(Initial adhesive strength)
The 20 mm width of the moisture-proof film was bonded to a 50 μm-thick PET film having a size of 50 mm × 100 mm by one reciprocation using a 2 kg hand roller.
After 30 minutes of bonding, this sample was fixed to a SUS plate via a double-sided tape, pulled at a peel angle of 180 degrees and a peel speed of 300 mm / min, and the adhesive strength was measured.

(Adhesive strength after heating)
The 20 mm width of the moisture-proof film was bonded to a 50 μm-thick PET film having a size of 50 mm × 100 mm by one reciprocation using a 2 kg hand roller.
Thereafter, thermocompression bonding was performed at 150 ° C. × 0.5 MPa for 5 seconds using a heating press device.
After heating and cooling, this sample was fixed to a SUS plate via a double-sided tape, and was pulled at a peel angle of 180 degrees and a peel speed of 300 mm / min, and the adhesive strength was measured.

(Anti-adhesive sticking out)
As described above, at the time of preparing the sample for measuring the adhesive strength after heating, the yield rate was calculated by assuming that the distance from which the adhesive protruded from the end of the base material of the sample after the preparation was less than 150 μm was good in protruding property.

(Delamination resistance)
A sample for measuring the adhesive strength after heating was placed with the PET film as the upper surface and the adhesive layer as the lower surface, and 50 individual holes were continuously drilled using the KOKUYO punching manual punch PN-31. The distance between the holes was 30 mm or more. At this time, the delamination resistance was calculated assuming that the delamination distance from the hole to the moisture-proof film was less than 100 μm as a good product.

(Metal corrosion resistance)
The moisture-proof film was bonded to a copper plate, and then, using a hot press apparatus, only the upper pressure-bonding bar was subjected to thermocompression bonding at 100 ° C. × 0.5 MPa for 2 seconds. 10 pieces of each sample were prepared.
After heating and cooling, this sample was put into 50 ° C. × 100% RH for 96 hours. After cooling for 10 minutes or more, the sample was peeled off, and it was visually confirmed whether the bonded portion of the moisture-proof film of the sample and the copper plate was not discolored as compared to before the addition. The case where 95% of the contact area was not discolored was regarded as non-defective product, and the non-defective product rate was calculated.

(Unevenness tracking)
Using a place where 6 wiring parts of Nitto Denko FPC (wiring height 15 μm, wiring space: 50 μm, wiring width 30 μm) are arranged in parallel, a moisture-proof film (20 mm width) is used with a 2 kg hand roller. One reciprocation was pasted together.
Thereafter, thermocompression bonding was performed at 120 ° C. × 0.5 MPa for 5 seconds using a heating press apparatus. Ten pieces of these samples were prepared.
After thermocompression bonding, all samples had no bubbles left between the wirings ◎ One sample with bubbles remaining ○, and two to three samples with bubbles remaining △,
Concavity and convexity followability was evaluated with x indicating that four or more bubbles remained.

(Transmittance)
The various adhesive solutions described above were applied onto a PET separator that had been subjected to a silicone lightening treatment, and dried at 110 ° C. for 5 minutes to finally form an adhesive layer having a thickness of 25 μm.
Thereafter, only the adhesive layer was isolated, and the transmittance of light at 330 nm was measured using a Shimadzu spectrophotometer UV-2200.
◎ with a transmittance of light of 330 nm 90% or more,
85% or more and less than 90%
Those less than 85% are indicated by x.

表２中、ＳＥＢＳ１：タフテックＭＰ１０（ＭＦＲ：４．０（ＩＳＯ １１３３、２３０℃、２．１６ｋｇｆ））、
ＳＥＢＳ２：タフテックＨ１０４１（ＭＦＲ：５．０（ＩＳＯ １１３３、２３０℃、２．１６ｋｇｆ））、
ＳＥＢＳ３：タフテックＭ１９１３（ＭＦＲ：５．０（ＩＳＯ １１３３、２３０℃、２．１６ｋｇｆ））、
ＳＥＢＳ４：タフテックＨ１０５２（ＭＦＲ：１３．０（ＩＳＯ １１３３、２３０℃、２．１６ｋｇｆ））、
ＳＥＢＳ５：ＪＳＲダイナロン８６００Ｐ、
ＥＶＡ１：エバフレックスＥＶ５５０（ＥＶＡ樹脂：ＶＡ含量１４ｗｔ％）である。

In Table 2, SEBS1: Tuftec MP10 (MFR: 4.0 (ISO 1133, 230 ° C., 2.16 kgf)),
SEBS2: Tuftec H1041 (MFR: 5.0 (ISO 1133, 230 ° C., 2.16 kgf)),
SEBS3: Tuftec M1913 (MFR: 5.0 (ISO 1133, 230 ° C., 2.16 kgf)),
SEBS4: Tuftec H1052 (MFR: 13.0 (ISO 1133, 230 ° C., 2.16 kgf)),
SEBS5: JSR Dynalon 8600P,
EVA1: EVAFLEX EV550 (EVA resin: VA content: 14 wt%).

  The moisture-proof film of the present invention has a simple configuration, is an extremely thin film, has good handling properties and good alignment characteristics during a pasting operation, and is useful for various electric and electronic devices.

Conventionally, in order to prevent water vapor from entering a laminated structure constituting an electronic device such as a liquid crystal display panel, the functionality of a moisture-proof film or the like on the upper and / or lower surface of such a laminated structure is known. A film is disposed (for example, Patent Document 1 : JP 2008-273211 A ).
However, with recent demands for thinning and weight reduction of these electronic devices, each layer constituting the laminated structure and its laminated structure, and further thinning / lightening of functional films laminated on the upper and lower surfaces thereof, etc. Is eager.
In particular, when a flexible substrate made of plastic or the like is used as a substrate constituting an electronic device such as an electronic paper or a mobile terminal, the moisture-proofing action is high because the moisture-proofing property is extremely low due to the characteristics of the material, and There is a strong demand to develop a moisture-proof film that is thin and lightweight.
As such a moisture-proof film, for example, a film having a laminated structure of PET film / aluminum layer / resin layer / adhesive layer has been proposed.

(Aluminum layer)
The aluminum layer is a layer imparting a function of preventing permeation of water vapor, for example, less than 5 × 10 ⁻² g / m ² · 24 h, preferably 1 × 10 ⁻² g / m ² · 24 h or less, and more preferably Can achieve water vapor transmission of 5 × 10 ⁻³ g / m ² · 24 h or less. The moisture-proof property is, for example, a value measured under conditions of 40 ° C. and RH 90% using PERMATRAN W3 / 33 (manufactured by MOCON) as a measuring device by the MOCON method (JIS K 712 9: 2008 ). Can do.

The styrene thermoplastic elastomer preferably has a styrene content of about 15% by weight or more, more preferably about 18% by weight or more, more preferably about 20% by weight or more, and about 30% by weight or more. Is even more preferable. Thereby, moderate initial fine adhesiveness can be given.
The hydrogenated styrenic thermoplastic elastomer preferably has an MFR of greater than 4.0 g / 10 minutes, more preferably 5.0 g / 10 minutes or more. MFR here means that at 230 ° C. according to ISO 1133 : 2005 , 2 . It is a value measured at 16 kgf. By having such MFR, it is possible to realize appropriate initial fine adhesion and increased adhesion by heating.

Claims (15)

An aluminum layer;
A laminate comprising a first protective layer and a second protective layer, which are laminated above and below the aluminum layer and have the same tensile elastic modulus,
The moisture-proof film characterized in that the laminate has a thickness of 50 μm or less and the aluminum layer has a thickness of 20 μm or less.   The moisture-proof film according to claim 1, wherein the first protective layer and the second protective layer are layers formed of the same material.   The moisture-proof film according to claim 1 or 2, wherein the first protective layer and the second protective layer are layers formed with the same thickness.   The moisture-proof film according to any one of claims 1 to 3, wherein each of the first protective layer and the second protective layer has a tensile elastic modulus of 1 GPa or more.   The moisture-proof film according to any one of claims 1 to 4, wherein each of the first protective layer and the second protective layer has a thickness of 80 to 150% of the aluminum layer. An adhesive layer on the surface of the second protective layer opposite to the aluminum layer;
The moisture-proof film according to any one of claims 1 to 5, wherein the adhesive layer satisfies a wettability of 70% or more as defined below.
Wetability: When the adhesive layer of the moisture-proof film is bonded to the adherend with one reciprocating load with a 2 kg hand roller, the moisture-proof film and the adherend are lifted upside down after a predetermined time and turned upside down once. The ratio of the adhesion area of the moisture-proof film and the adherend to the total area of the moisture-proof film. An adhesive layer on the surface of the second protective layer opposite to the aluminum layer;
The moisture-proof film according to claim 6, wherein the adhesive layer is made of an adhesive containing a styrene-based thermoplastic elastomer as a base material.   The moisture-proof film according to claim 6 or 7, wherein the adhesive layer is made of an adhesive containing a styrene / ethylene butylene / styrene block copolymer as a base material.   The moisture-proof film according to any one of claims 6 to 8, wherein the adhesive layer comprises an adhesive containing, as a base material, a styrene / ethylene butylene / styrene block copolymer having a styrene content of 15% by weight or more.   The moisture-proof film according to any one of claims 6 to 9, wherein the adhesive layer is made of an adhesive containing a modified styrene / ethylene butylene / styrene block copolymer as a base material.   The moisture-proof film according to any one of claims 8 to 10, wherein the modified styrene / ethylene butylene / styrene block copolymer is an unmodified product or an amino-modified product.   The moisture-proof film according to any one of claims 6 to 11, wherein the adhesive layer has an adhesive force of 1 N / 20 mm or less.   The moisture-proof film according to any one of claims 6 to 12, wherein the adhesive layer has a property of being ten times or more larger than an adhesive force before heating by heating the moisture-proof film.   The moisture-proof film according to any one of claims 6 to 13, wherein the adhesive layer has an adhesive force of 3 N / 20 mm or more by heating the moisture-proof film. An electric / electronic device comprising the moisture-proof film according to claim 1.