JP6657651B2 - Moisture barrier resin laminate - Google Patents

Description

  The present invention relates to a moisture barrier laminate having an inorganic barrier layer and a moisture absorbing layer (moisture trap layer).

  As a means for improving the properties of various plastic substrates, particularly gas barrier properties, it is known to form an inorganic barrier layer made of silicon oxide or the like on the surface of a plastic substrate by vapor deposition (Patent Document 1). ).

  By the way, various electronic devices developed and put into practical use in recent years, such as organic electroluminescence (organic EL), solar cells, touch panels, and electronic papers, dislike charge leakage. A high moisture barrier property is required for a plastic substrate such as a film for sealing a substrate or a circuit board. Since the formation of the inorganic barrier layer described above cannot meet such a high demand for the moisture barrier property, various proposals for improving the moisture barrier property have been made.

For example, in Patent Document 2, an inorganic barrier layer is formed on the surface of a plastic substrate, and a sealing layer in which nanoparticles such as metal oxides and carbon nanotubes are dispersed as a moisture absorbent is provided on the inorganic barrier layer. A laminated body having gas barrier properties has been proposed.
Patent Literature 3 proposes a gas barrier laminate (film) in which an organic layer, an inorganic barrier layer, and a water-trapping layer are formed on a base film, and the water-trapping layer is made of a hygroscopic polymer ( Specifically, it is disclosed that it is formed from polyamide (polyamide) or by dispersing a hygroscopic material such as silica gel or aluminum oxide in a polymer binder such as an electron beam or ultraviolet curable resin.
Further, Patent Document 4 has a gas barrier film layer formed by vapor deposition and a moisture absorbing layer on the surface of a plastic substrate, and the moisture absorbing layer contains alkylene oxide, acrylate nanoparticles, or an organometallic complex. Gas barrier laminates have been proposed.

  In Patent Documents 5 to 7, the present applicant discloses that a moisture trap layer in which a specific particulate moisture absorbent is dispersed in a matrix of an ionic polymer is formed on an inorganic barrier layer on a plastic substrate. Gas barrier laminates have been proposed.

  As described above, various laminates having a layer configuration in which an inorganic barrier layer and a moisture absorbing layer (water trapping layer) are combined have been proposed in order to highly enhance the moisture barrier property. Deactivation occurs in a short period of time, and there is a problem that excellent moisture barrier properties are not sufficiently exhibited.

JP-A-2000-255579 JP 2010-511267 A JP 2009-90633 A JP 2011-131395 A WO2014 / 123197 JP 2014-168949 A JP 2014-168950 A

  Therefore, an object of the present invention is to provide a moisture barrier laminate comprising an inorganic barrier layer and a moisture absorbing layer, in which the deactivation of the moisture absorbing layer is effectively suppressed, and excellent barrier properties against moisture are stably exhibited over a long period of time. Is to provide.

  The present inventors have conducted many experiments on the deactivation of the moisture absorbing layer, and as a result of repeated studies, this deactivation is derived from defects such as cracks locally occurring in the inorganic barrier layer, Due to this defect, it has been found that moisture locally permeates the inorganic barrier layer and the moisture absorbing layer is locally deactivated, and based on this finding, the present invention has been completed.

According to the present invention, a moisture barrier laminate having an inorganic barrier layer and a moisture absorbing layer, wherein the inorganic barrier layer is disposed on the high moisture atmosphere side with respect to the moisture absorbing layer,
There is provided a moisture barrier laminate having an organic layer having a thickness of 10 μm or more interposed between the moisture absorbing layer and the inorganic barrier layer.

In the moisture barrier laminate of the present invention,
(1) the organic layer has a moisture diffusion function and is provided adjacent to the moisture absorbing layer;
(2) the organic layer has a water vapor transmission coefficient of 2.0 g · mm / m ² · day / atm or less;
(3) the organic layer contains a polyester resin or an olefin resin;
(4) the organic layer has a thickness three times or more the thickness of the moisture absorbing layer;
(5) The water vapor permeability of the laminate is 0.01 g / m ² · day / atm or less;
Is preferred.

The moisture barrier laminate of the present invention has an inorganic barrier layer and a moisture absorbing layer, but has a basic structure in which the inorganic barrier layer is disposed on the high moisture atmosphere side with respect to the moisture absorbing layer. . That is, when this laminate is attached to a device such as an organic EL device, an inorganic barrier layer is disposed on the air side with respect to the moisture absorbing layer. Therefore, the moisture absorbing layer is located inside the device with respect to the inorganic barrier layer. Side. Therefore, the structure is such that moisture permeates from the inorganic barrier layer side to the moisture absorbing layer side.
In the moisture barrier laminate having such a basic structure, in the present invention, an organic layer having a thickness of 10 μm or more is provided between the inorganic barrier layer and the moisture absorbing layer. Can be effectively suppressed, and a stable and excellent moisture barrier property can be exhibited over a long period of time.

For example, a moisture-absorbing layer is provided between two inorganic barrier layers (vapor-deposited layers of silicon oxide) having a water vapor permeability of 0.1 g / m ² · day / atm, and the moisture-absorbing layer and one of the inorganic barrier layers are provided. A laminate in which an organic layer (PET layer) having a thickness of 100 μm is provided between the layer and the laminate, and the moisture barrier property of the laminate is evaluated, is shown in Examples and Comparative Examples described later. As described above, the following results are obtained (for the measurement of the moisture permeability and the like, refer to the examples).
That is, the above-mentioned laminated body is formed such that one inorganic barrier layer faces a high humidity atmosphere (relative humidity 90%), the other inorganic barrier layer faces a low humidity atmosphere (relative humidity 0%), Are arranged on the low humidity side with respect to the moisture absorbing layer (Comparative Example 1). In this case, the water vapor passes through the inorganic barrier layer, the moisture absorbing layer, the organic layer, and the inorganic barrier layer in this order, and flows directly from the inorganic barrier layer to the moisture absorbing layer. The moisture permeability of the laminated body arranged as described above shows 0.01 g / m ² · day / atm in a short time, but increases to 0.03 g / m ² · day / atm or more after one day or more. I do.
On the other hand, according to the present invention, when the above-mentioned organic layer is disposed so as to be located on the high humidity side with respect to the moisture absorbing layer (Example 1), water vapor passes through the inorganic barrier layer / organic layer / moisture absorbing layer / inorganic layer The water passes through the barrier layer in this order, and the water vapor flows from the inorganic barrier layer through the organic layer to the moisture absorbing layer. Surprisingly, the moisture permeability of the laminated body arranged in this manner can maintain a barrier property of less than 0.01 g / m ² · day / atm for 100 hours or more, and the long-term stability is greatly increased. Has improved.

  As described above, in the present invention, an excellent moisture barrier property can be exhibited by forming a layer structure in which water vapor flows from the inorganic barrier layer to the moisture absorbing layer via the organic layer. Therefore, the moisture barrier laminate of the present invention is effectively used for various devices that do not want to invade moisture, is useful as a substrate or a sealing layer of various devices, and is particularly suitable for an organic electroluminescence (organic EL) panel. Applied to

It is an explanatory view for explaining the principle of expression of moisture barrier properties in the moisture barrier laminate of the present invention. The figure which shows the layer structure of the moisture barrier laminated body 10 produced in Examples 1-3. The figure which shows the layer structure of the moisture-barrier laminated body 11 produced in Examples 4-6. The figure which shows the layer structure of the moisture-barrier laminated body 12 produced in Example 7.

<Principle of the present invention>
The moisture barrier laminate of the present invention has a basic structure in which an inorganic barrier layer is disposed on the high moisture atmosphere side with respect to the moisture absorbing layer. A thick (10 μm or more) organic layer is provided on the high moisture atmosphere side. That is, moisture (water vapor) in a high moisture atmosphere passing through the inorganic barrier layer flows into the moisture absorbing layer via the organic layer, and is captured by the moisture absorbing layer. The reason that such a structure greatly improves the moisture barrier property is that a thick organic layer existing between the inorganic barrier layer and the moisture absorbing layer functions as a moisture diffusion layer.

Please refer to FIG. 1 for explaining this principle.
For example, in FIG. 1A, the moisture absorbing layer 3 is provided directly on the inorganic barrier layer 1 facing the high moisture atmosphere side, and moisture is absorbed from the inorganic barrier layer 1 as shown by the arrow. It flows to the layer 3.
Incidentally, the inorganic barrier layer is an inorganic vapor-deposited film formed by physical vapor deposition, chemical vapor deposition, or the like, is formed of various metals or metal oxides, and has a high barrier property against moisture. However, they inevitably include fine defects such as pinholes and cracks. This defect is indicated by X in the figure.
Therefore, in FIG. 1A, a large amount of water flows into the moisture absorbing layer 3 through the defect X. Therefore, in the moisture absorbing layer 3, a portion facing the defect X is faster than other portions. It will be saturated and the moisture barrier property will be degraded. That is, even if the moisture barrier property in a short time is high, for example, after one day or more, the moisture barrier property is greatly reduced.

  On the other hand, according to the present invention, when the thick organic layer 5 is provided between the inorganic barrier layer 1 and the moisture absorbing layer 3 as shown in FIG. The moisture passing through the defect X flows into the organic layer 5 and flows into the moisture absorbing layer 3 through the organic layer 5. That is, in this case, the moisture flowing into the organic layer 5 from the defect X is diffused in the organic layer 5 because the thickness of the organic layer 5 is moderately large, and as a result, the water is dispersed in the plane direction of the organic layer 5. In this state, it flows into the moisture absorbing layer 3. As a result, as shown in FIG. 1A, the inconvenience of locally concentrated water flowing into the hygroscopic layer 3 is effectively avoided.

Such an effect of improving the long-term stability is particularly effective as the barrier property of the inorganic barrier layer 1 is higher. For example, in the case of an inorganic barrier layer having a water vapor permeability of 10 ⁻³ to 10 ⁻⁴ g / m ² / day, the number of defects X is very small, and the permeation of water vapor is extremely localized. If the thick organic layer 5 is not provided between the inorganic barrier layer 1 and the moisture absorbing layer 3, the moisture passing through the defect X of the inorganic barrier layer 1 is extremely locally concentrated in the moisture absorbing layer 3. It will flow into. That is, only a very small portion of the moisture absorbing layer 3 contributes to moisture absorption, and most of the moisture absorbing layer 3 does not contribute to moisture absorption, so that the moisture barrier property deteriorates more quickly. By providing the organic layer 5 having an appropriate thickness between the inorganic barrier layer 1 and the moisture absorbing layer 3, as shown in FIG. As a result, the entire structure functions stably as a trap layer for blocking moisture for a long period of time without deteriorating, and excellent moisture barrier properties are exhibited.

<Inorganic barrier layer 1>
In the present invention having the above-described basic structure, the inorganic barrier layer 1 located on the high moisture atmosphere side is formed by physical vapor deposition represented by sputtering, vacuum deposition, ion plating, or the like, or chemical vapor deposition represented by plasma CVD. An inorganic deposited film formed by, for example, a film formed of various metals or metal oxides. In particular, the film is formed evenly on a surface having irregularities, and is not only resistant to moisture but also to oxygen and the like. From the viewpoint of exhibiting excellent barrier properties, a vapor-deposited film formed by plasma CVD is preferable.
Further, such an inorganic barrier layer 1 is formed on a predetermined plastic base material, and the plastic base material may be the organic layer 5 having the above-described moisture diffusion function, or may be the same as the organic layer 5. It may be different. When the plastic substrate is different from the organic layer 5, the organic layer 5 is formed thereon after the inorganic barrier layer 1 is formed.

In addition, the deposition film (inorganic barrier layer 1) formed by plasma CVD includes a metal substrate or a metal for forming a film, in which a plastic substrate to support the inorganic barrier layer is placed in a plasma processing chamber maintained at a predetermined degree of vacuum. A compound gas (reaction gas) and an oxidizing gas (usually oxygen or NOx gas) are appropriately sealed together with a carrier gas such as argon or helium using a gas supply pipe with a metal wall shielded to a predetermined degree of vacuum. It is supplied to a decompressed plasma processing chamber, and in this state, a glow discharge is generated by a microwave electric field or a high-frequency electric field, and plasma is generated by the electric energy. It is obtained by depositing and forming a film.
In the case of using a microwave electric field, a film is formed by irradiating a microwave into a plasma processing chamber using a waveguide or the like, and in the case of using a high-frequency electric field, a plastic substrate in the plasma processing chamber is paired with a pair of electrodes. The film is formed by applying a high-frequency electric field to this electrode.

  As the above-mentioned reaction gas, an organometallic compound is generally used from the viewpoint that a film having a flexible region containing a carbon component on the surface of a plastic substrate and having a region having a high degree of oxidation and excellent barrier properties can be formed thereon. For example, it is preferable to use a gas such as an organic aluminum compound such as a trialkylaluminum, or an organic titanium compound, an organic zirconium compound or an organic silicon compound. Organosilicon compounds are most preferred in that they can be formed well.

  Examples of such organosilicon compounds include hexamethyldisilane, vinyltrimethylsilane, methylsilane, dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, methyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane Organic silane compounds such as tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, octamethylcyclotetrasiloxane, 1,1,3,3-tetramethyldisiloxane, hexamethyl An organic siloxane compound such as disiloxane is used. In addition, aminosilane, silazane, or the like can also be used.

  The above-mentioned organometallic compounds can be used alone or in combination of two or more.

  In the present invention, when forming a film by plasma CVD using a reaction gas of an organometallic compound and an oxidizing gas as described above, the glow discharge output (for example, microwave or high frequency output) is reduced, and the film is formed at a low output. After the start of the above, it is preferable to form a film by a plasma reaction at a high output.

That is, the organic group (CH ₃ or CH _2, etc.) contained in the molecule of the organometallic compound is usually volatilized as CO ₂ , but at a low output, a part thereof is not decomposed to CO ₂ , It is deposited on the surface of the substrate and included in the film. On the other hand, the higher the output, the more the organic group is decomposed to CO ₂ . Therefore, by increasing the output, the C content in the film can be reduced, and a film having a high degree of oxidation of the metal contained in the organometallic compound can be formed. However, a film having a high degree of oxidation of a metal has a very high barrier property against gases such as oxygen, but has poor flexibility and insufficient adhesion to a plastic substrate, but has a low degree of oxidation of a metal. A film having a high content of organic components does not have sufficient gas barrier properties, but has high flexibility and exhibits high adhesion to a plastic substrate.

  As understood from the above description, according to the present invention, an organometallic compound is used as a reaction gas, and a film is formed by increasing the output after the film is formed at a low output in the initial stage of the film formation by plasma CVD. As a result, a region with high adhesion containing a large amount of an organic component (carbon) is formed in a portion in contact with the surface of the plastic substrate, and a region with a high degree of metal oxidation and a high gas barrier property is formed thereon. Become.

  Therefore, the inorganic barrier layer 1 in the moisture barrier laminate of the present invention has a metal (M) oxidation degree of x (x = atomic ratio of O / M) in order to ensure excellent gas barrier properties. It is preferable that this oxidation degree x includes a high oxidation degree region of 1.5 to 2.0. The lower side of the high oxidation degree region (the side in contact with the surface of the plastic substrate) has a carbon (C) concentration of 20 based on the three elements of metal (M), oxygen (O) and carbon (C). It is preferable that an organic region of element% or more is formed. Further, silicon (Si) is most preferable as the metal (M).

  The high oxidation degree region in the inorganic barrier layer 1 preferably exists at a rate of 60% or more of the total thickness of the inorganic barrier layer 1, and the organic region has a thickness of 5% of the total thickness of the inorganic barrier layer 1. It is preferably formed on the side in contact with the surface of the plastic substrate with a thickness of about 40%.

The glow discharge output when the inorganic barrier layer 1 having the above-mentioned organic region or high oxidation degree region is formed by plasma CVD is slightly different between a case using a microwave and a case using a high frequency. For example, in the case of a microwave, an organic region is formed at a low output of about 30 to 100 W, and in a high oxidation degree region, a film is formed at a high output of 90 W or more. In the case of high frequency, the organic region is formed with a low output of about 20 to 80 W, and in the high oxidation degree region, the film is formed with a high output of 100 W or more.
The film formation time may be set so that the thickness of each region falls within the above-described range.

In addition, the overall thickness of the above-mentioned inorganic barrier layer 1 varies depending on the use of the moisture barrier laminate and the required level of barrier properties, but generally the properties of the plastic substrate such as the organic layer 5 are impaired. It is preferable that the thickness be set to such a thickness that water vapor permeability of 10 ⁻² g / m ² · day / atom or less, particularly 10 ⁻³ g / m ² · day / atom or less can be secured. Although it differs depending on the ratio occupied by the degree region, it is generally sufficient that the layer has a thickness of about 4 to 500 nm, especially about 30 to 400 nm.

<Hygroscopic layer 3>
The moisture absorbing layer 3 in the moisture barrier laminate of the present invention can also be called a moisture trapping layer, and may be a layer known per se, such as a layer in which a particulate moisture absorbing agent is dispersed in a predetermined resin layer.
In particular, when a high barrier property against moisture is required, for example, Patent Documents 5 to 7 describe, from the viewpoint of excellent moisture trapping properties and effective prevention of deformation such as swelling due to moisture absorption. As described above, the layer is preferably a layer in which a particulate adsorbent is dispersed in an ionic polymer.

The ionic polymer forms a matrix of the moisture absorbing layer 3, and includes a cationic polymer having a cationic group (such as an NH ₂ group) as an ionic group and an anionic group (COONa group) as an ionic group. , COOH groups, etc.), and as the particulate adsorbent, those having a lower reaching humidity than the ionic polymer are generally used.

That is, in the moisture absorbing layer 3 having the ionic polymer as a matrix, a small amount of water flowing through the above-described inorganic barrier layer 1 is absorbed by the matrix (ionic polymer). Since the matrix itself exhibits high hygroscopicity, it captures and absorbs moisture without leakage.
By the way, when moisture is simply absorbed by the matrix, the absorbed moisture is easily released due to environmental changes such as temperature rise. In addition, the penetration of moisture increases the distance between polymer molecules forming the matrix, and as a result, the moisture absorbing layer 3 swells.
However, when the particulate adsorbent having a lower reaching humidity than the matrix (ionic polymer) is dispersed, the water absorbed in the matrix has a higher hygroscopic property than the matrix (that is, a lower reaching humidity). ) It is further trapped by the moisture absorbent, and not only is the swelling due to the absorbed water molecules effectively suppressed, but also the water molecules are confined in the moisture absorption layer 3, and as a result, the water content from the moisture absorption layer 3 is reduced. Release is also effectively prevented.

  As described above, when the moisture absorbing layer 3 is formed by dispersing the particulate adsorbent in the ionic polymer, the moisture absorbing layer 3 has a high function of absorbing moisture and a dual function of capturing and confining moisture. Moisture can be captured even in a low-humidity atmosphere, and is captured at a speed sufficiently faster than the speed at which the inorganic barrier layer penetrates. High moisture barrier properties can be realized.

Ionic polymers (cationic polymers);
In the present invention, among the ionic polymers used to form the matrix as described above, the cationic polymer is a cationic group that can be positively charged in water, for example, a primary to tertiary amino group, a quaternary ammonium group, It is a polymer having a pyridyl group, an imidazole group, a quaternary pyridinium or the like in a molecule. Such a cationic polymer can form a hygroscopic matrix because the cationic group has a strong nucleophilic action and captures water by hydrogen bonding.
In general, the amount of the cationic group in the cationic polymer is such that the water absorption (JIS K-7209-1984) of the formed hygroscopic matrix is 20% or more, particularly 30% to 45% at 80% RH and 30 ° C. in an atmosphere of humidity. %.

Examples of the cationic polymer include amine monomers such as allylamine, ethyleneimine, vinylbenzyltrimethylamine, [4- (4-vinylphenyl) -methyl] -trimethylamine, and vinylbenzyltriethylamine; and vinylpyridine, vinylimidazole and the like. At least one kind of cationic monomer represented by a nitrogen-containing heterocyclic monomer; and a salt thereof, is appropriately polymerized or copolymerized with another copolymerizable monomer, and If necessary, those obtained by partial neutralization by acid treatment are used.
Examples of other copolymerizable monomers include, but are not limited to, styrene, vinyl toluene, vinyl xylene, α-methyl styrene, vinyl naphthalene, α-halogenated styrenes, acrylonitrile, and acrolein. , Methyl vinyl ketone, vinyl biphenyl and the like.

  Further, instead of using the above cationic monomer, a monomer having a functional group capable of introducing a cationic functional group, for example, styrene, bromobutylstyrene, vinyltoluene, chloromethylstyrene, vinylpyridine, vinyl A cationic polymer can also be obtained by using imidazole, α-methylstyrene, vinylnaphthalene, or the like, and performing a treatment such as amination or alkylation (quaternary ammonium chloride) after polymerization.

  In the present invention, among the above cationic polymers, allylamine is particularly preferred from the viewpoint of film formability and the like.

The polymerization for forming the above-described cationic polymer is generally carried out by radical polymerization by heating using a polymerization initiator.
The polymerization initiator is not particularly limited, and may be octanoyl peroxide, lauroyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, or t-butylperoxide. Organic peroxides such as oxylaurate, t-hexylperoxybenzoate, di-t-butyl peroxide and the like are typical, and generally, the aforementioned anionic or cationic monomer (or anionic group or cationic group) is used. It is used in an amount of about 0.1 to 20 parts by weight, especially about 0.5 to 10 parts by weight, based on 100 parts by weight of a monomer capable of introducing a group.

  By performing the polymerization as described above, a cationic polymer can be obtained.If a monomer capable of introducing a cationic functional group is used, after polymerization, amination, alkylation treatment, etc. What is necessary is just to perform a cationic group introduction process.

In the present invention, the cross-linking structure is introduced into the matrix formed using the above-mentioned cationic polymer, thereby ensuring the mechanical strength without lowering the moisture absorption capacity and improving the dimensional stability. It is preferable in making it.
That is, when a crosslinked structure is introduced into a hygroscopic matrix, when the matrix absorbs water, the molecules of the cationic polymer are restrained by crosslinkage, and the volume change due to swelling (moisture absorption) is suppressed. Control, resulting in improved mechanical strength and dimensional stability.
The above crosslinked structure can be introduced by blending a crosslinking agent into the coating composition for forming the moisture absorbing layer 3.

Ionic polymers (anionic polymers);
In the present invention, the anionic polymer used to form the hygroscopic matrix is an anionic functional group that can be negatively charged in water, for example, a carboxylic acid group, a sulfonic acid group, a phosphonic acid group, or any of these groups. A polymer having a partially neutralized acidic base in the molecule. An anionic polymer having such a functional group can form a hygroscopic matrix because the functional group captures water by hydrogen bonding.
Although the amount of the anionic functional group in the anionic polymer varies depending on the type of the functional group, similarly to the above-described cationic polymer, the water absorption (JIS K-7209-1984) of the formed hygroscopic matrix is 80% humidity. The amount may be 20% or more, particularly 30% to 45% in an atmosphere of RH and 30 ° C.

Examples of the anionic polymer having a functional group as described above include carboxylic acid monomers such as methacrylic acid, acrylic acid, and maleic anhydride; α-halogenated vinylsulfonic acid, styrenesulfonic acid, vinylsulfonic acid, and the like. At least one of anionic monomers represented by sulfonic acid-based monomers; phosphonic acid-based monomers such as vinylphosphoric acid; and salts of these monomers; A polymer obtained by polymerization or copolymerization with the above monomer and, if necessary, partial neutralization by an alkali treatment is used.
Examples of other copolymerizable monomers include, but are not limited to, styrene, vinyl toluene, vinyl xylene, α-methyl styrene, vinyl naphthalene, α-halogenated styrenes, acrylonitrile, and acrolein. , Methyl vinyl ketone, vinyl biphenyl and the like.

  Further, instead of using the above anionic monomer, an ester of the above anionic monomer, a monomer having a functional group capable of introducing an anionic functional group, for example, styrene, vinyl toluene, vinyl Using xylene, α-methylstyrene, vinylnaphthalene, α-halogenated styrenes, etc., after polymerization, an anionic polymer can be obtained by performing a treatment such as hydrolysis, sulfonation, chlorosulfonation, or phosphonium formation. .

  In the present invention, suitable anionic polymers are poly (meth) acrylic acid and partially neutralized products thereof (for example, those partially a Na salt).

Incidentally, the polymerization for forming the above-mentioned anionic polymer is generally carried out by radical polymerization by heating using a polymerization initiator.
The polymerization initiator is not particularly limited, and may be octanoyl peroxide, lauroyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, or t-butylperoxide. Organic peroxides such as oxylaurate, t-hexylperoxybenzoate, and di-t-butyl peroxide are typical, and generally, the above-described anionic monomer (or a monomer capable of introducing an anionic group) is used. It is used in an amount of about 0.1 to 20 parts by weight, especially about 0.5 to 10 parts by weight, based on 100 parts by weight of the composition.

  By performing polymerization as described above, an anionic polymer can be obtained.If a monomer capable of introducing an anionic functional group is used, hydrolysis, sulfonation, or chlorsulfonation is performed after polymerization. Anionic group introduction treatment such as phosphonium conversion may be performed.

In the present invention, it is particularly preferable to introduce a crosslinked structure into the hygroscopic matrix formed by using the above-described anionic polymer, whereby the moisture trapping ability of the hygroscopic layer 3 is further enhanced, Moreover, the dimensional stability is further improved.
That is, in the case of an anionic polymer, unlike a cationic polymer, only water is captured by hydrogen bonding. Therefore, by introducing a network structure (cross-linking structure) of a space suitable for absorbing moisture into a matrix, the hygroscopic property is reduced. Can be greatly increased. Such a crosslinked structure has, for example, a hydrophobic portion such as an alicyclic structure in a network structure, whereby the moisture absorbing effect of the hydrophilic portion is further enhanced.
Furthermore, by introducing a cross-linked structure into the hygroscopic matrix, when the matrix absorbs water, the molecules of the anionic polymer are bound to each other by the cross-linking, the volume change due to swelling (moisture absorption) is suppressed, and dimensional stability is achieved. The performance is improved. Such an effect of improving the dimensional stability is the same as that of the above-described cationic polymer.

  The above-mentioned crosslinked structure is introduced by blending a crosslinking agent in a coating composition for forming the moisture absorbing layer 3 as in the case of the cationic polymer.

Granular hygroscopic agent;
The particulate moisture absorbing agent dispersed in the moisture absorbing layer 3 having the above-described ionic polymer as a matrix (hygroscopic matrix) has a lower reaching humidity than the ionic polymer (cationic or anionic polymer) forming the matrix. It has extremely high moisture absorption performance. By dispersing the hygroscopic agent having a higher hygroscopic property than the matrix in this manner, the moisture absorbed in the matrix formed by the ionic polymer described above is immediately captured by the hygroscopic agent, and the absorbed moisture is introduced into the matrix. Is effectively performed, so that not only the moisture absorbing ability can be effectively exhibited even in an extremely low humidity atmosphere, but also the swelling of the moisture absorbing layer 3 due to the absorption of moisture is effectively suppressed.

  As the highly hygroscopic particulate hygroscopic agent as described above, provided that the ultimate humidity is lower than that of the ionic polymer, for example, as shown in Examples described later, a humidity of 80% RH and a temperature of 30 ° C. It is preferable to use a material having an attainable humidity of 6% or less under environmental conditions. That is, when the arrival humidity of the hygroscopic agent is higher than that of the ionic polymer, confinement of the water absorbed in the matrix is not sufficient, and the release of the water and the like are likely to occur. I will. Further, even when the ultimate humidity is lower than that of the ionic polymer, if the ultimate humidity measured under the above conditions is higher than the above range, for example, the trapping of moisture in a low humidity atmosphere becomes insufficient, and the moisture barrier property becomes poor. May not be fully exhibited.

The particulate moisture absorbent as described above generally has a water absorption of 50% or more (JIS K-7209-1984) in an atmosphere of a humidity of 80% RH and a temperature of 30 ° C., and includes inorganic and organic ones. .
Examples of the inorganic moisture absorbent include zeolite, alumina, activated carbon, clay minerals such as montmorillonite, silica gel, calcium oxide, and magnesium sulfate.
Examples of the organic moisture absorbent include a crosslinked product of an anionic polymer or a partially neutralized product thereof. Examples of the anionic polymer include carboxylic acid monomers (such as (meth) acrylic acid and maleic anhydride), sulfonic acid monomers (such as halogenated vinyl sulfonic acid, styrene sulfonic acid, and vinyl sulfonic acid), and phosphonic acid monomers. Examples include those obtained by polymerizing or copolymerizing at least one type of anionic monomer represented by an acid monomer (eg, vinyl phosphoric acid) and salts of these monomers with another monomer. be able to. In particular, in applications where transparency is required, an organic moisture absorbent is effective. For example, fine particles of cross-linked sodium poly (meth) acrylate are typical organic hygroscopic agents.

In the present invention, a hygroscopic agent having a small particle size is preferable (for example, having an average primary particle size of 100 nm or less, particularly 80 nm or less) from the viewpoint of a large specific surface area and high hygroscopicity. Polymeric desiccants are optimal.
That is, the organic polymer desiccant has an extremely good dispersibility in the matrix of the ionic polymer and can be uniformly dispersed. In addition, as a polymerization method for producing the same, emulsion polymerization, suspension polymerization, or the like is used. By adopting the above, the particle shape can be made into a fine and uniform spherical shape, and by blending this to a certain degree or more, it becomes possible to secure extremely high transparency.
In addition, in the organic fine hygroscopic agent, the above-mentioned ultimate humidity is extremely low, and not only shows high hygroscopicity, but also the volume change due to swelling due to crosslinking can be extremely reduced, and therefore, while suppressing the volume change, It is most suitable for reducing the humidity of an environmental atmosphere to a completely dry state or a place close to a completely dry state.
As the fine particles of such an organic hygroscopic agent, for example, cross-linked sodium polyacrylate fine particles (average particle diameter of about 70 nm) in the form of a colloidal dispersion (pH = 10.4) from Toyobo Co., Ltd. It is marketed under the trade name.

In the present invention, the amount of the particulate hygroscopic agent as described above sufficiently exerts its properties, remarkably improves the moisture barrier property and effectively suppresses the dimensional change due to swelling, and at the same time, the barrier property exhibited by the inorganic barrier layer 1. It is set according to the type of the ionic polymer from the viewpoint of ensuring higher moisture barrier properties over a long period of time.
For example, when the above-mentioned ionic polymer is used as a matrix, and the particulate adsorbent is dispersed in the matrix, the moisture-absorbing layer 3 is made of the ionic polymer in the moisture-absorbing layer 3 when the matrix is formed of a cationic polymer. It is preferably present in an amount of 50 parts by weight or more, especially 100 to 900 parts by weight, more preferably 200 to 600 parts by weight, per 100 parts by weight. When the matrix is formed of an anionic polymer, it is preferably present in an amount of 50 parts by weight or more, particularly 100 to 1300 parts by weight, per 100 parts by weight of the anionic polymer in the moisture absorbing layer 3. More preferably, the amount is from 150 to 1200 parts by weight.

<Organic layer 5>
In the present invention, the organic layer 5 provided between the inorganic barrier layer 1 and the moisture absorbing layer 3 disposed on the high moisture atmosphere side has basically more moisture permeability than the moisture absorbing layer 3 and the inorganic barrier layer 1. It can be formed of any resin having a thickness of 10 μm or more, particularly 20 μm or more, and more preferably 3 times or more the thickness of the moisture absorbing layer 3. .
As described above, inevitable defects X such as pinholes and cracks are generated in the inorganic barrier layer 1, and moisture flows locally through the defects X into the moisture absorbing layer 3. Therefore, there is a disadvantage that the moisture barrier property of the moisture absorbing layer 3 is locally deteriorated. However, in the present invention, the thick organic layer 5 is interposed between the inorganic barrier layer 1 and the moisture absorbing layer 3. Therefore, a small amount of moisture that has passed through the defect X of the inorganic barrier layer 1 penetrates the organic layer 5 while diffusing in the plane direction due to the organic layer 5, and as a result, the moisture is evenly distributed over the entire plane of the moisture absorbing layer 3. Flows in, the entire moisture absorbing layer 3 exhibits a moisture trapping property, and the disadvantage that the moisture barrier property is locally deteriorated can be effectively avoided.
For example, when the thickness of the organic layer 5 is smaller than the above range, the moisture flowing from the defect X passes through the moisture absorbing layer 3 without substantially diffusing in the surface direction and flows into the moisture absorbing layer 3. It is difficult to avoid local degradation. That is, when a thin layer such as an adhesive resin layer is provided on the inorganic barrier layer 1 and the moisture absorbing layer 3 is provided via the adhesive resin layer, moisture is sufficiently diffused by the adhesive resin layer. Therefore, local deterioration of the moisture absorption layer 3 cannot be avoided.

  Such an organic layer 5 may be made of a thermoplastic or thermosetting resin known per se, provided that the organic layer 5 has a certain thickness or more, as described above. From the viewpoint of the like, α-olefins such as low density polyethylene, high density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene or ethylene, propylene, 1-butene, 4-methyl-1-pentene, etc. Polyolefins such as random or block copolymers, cyclic olefin copolymers, etc., and ethylene / vinyl compound copolymers such as ethylene / vinyl acetate copolymer, ethylene / vinyl alcohol copolymer, ethylene / vinyl chloride copolymer Coal, polystyrene, acrylonitrile / styrene copolymer, ABS, α-methylstyrene / styrene Styrene resins such as copolymers, polyvinyl chloride, polyvinylidene chloride, vinyl chloride / vinylidene chloride copolymer, polyvinyl compounds such as polymethyl acrylate, polymethyl methacrylate, nylon 6, nylon 6-6, nylon 6-10, polyamides such as nylon 11 and nylon 12, thermoplastic polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate (PEN); polycarbonate; polyphenylene oxide; and other polyimide resins and polyamide imides Examples include resins, polyetherimide resins, fluororesins, allyl resins, polyurethane resins, cellulose resins, polysulfone resins, polyethersulfone resins, ketone resins, amino resins, and biodegradable resins such as polylactic acid. It can further or blends thereof, may be what these resins are modified by appropriate copolymerization (e.g., an acid-modified olefin resin).

  The organic layer 5 may be formed of a plurality of layers, provided that the total thickness is not less than a certain thickness (not less than 10 μm, particularly not less than 20 μm). For example, in order to ensure adhesion with the inorganic barrier layer 1, the organic layer 5 may have a multilayer structure, and the layer on the interface side with the inorganic barrier layer 1 may be formed of an adhesive resin such as an acid-modified olefin resin. It is possible. Further, an oxygen barrier layer formed of a gas barrier resin such as an ethylene / vinyl alcohol copolymer may be formed in the organic layer 5.

Furthermore, in the present invention, the organic layer 5 is preferably a layer having low moisture permeability, for example, 2.0 g · mm / m ² · day / atm or less, particularly 0.5 g · mm / m ² · day. It is preferable that the layer has a water vapor transmission coefficient of not more than / atm. That is, the lower the moisture permeability of the organic layer 5, the higher the function of diffusing the moisture (water vapor) flowing through the defect X of the inorganic barrier layer 1 in the plane direction, and the thickness of the organic layer 5 is excessively increased. This is because the local deterioration of the moisture absorbing layer 3 can be effectively suppressed without the need.

  In the present invention, the organic layer 5 is formed of a polyester resin such as polyethylene terephthalate (PET) or an olefin resin such as polyethylene or polypropylene from the viewpoints of availability, cost, moldability, and moisture diffusibility. It is most suitable to form with.

<Layer structure of moisture barrier laminate and production thereof>
In the moisture barrier laminate of the present invention, the inorganic barrier layer 1 is located at a position on the high moisture atmosphere side with respect to the moisture absorbing layer 3, and an organic layer is provided between the inorganic barrier layer 1 and the moisture absorbing layer 3. Various layer structures can be adopted under the condition that they have the basic structure that 5 is provided.

For example, the simplest layer structure is the following three-layer structure as shown in FIG.
(High moisture atmosphere side): Inorganic barrier layer 1 / Organic layer 5 / Hygroscopic layer: (Low moisture atmosphere side)

  In the moisture barrier laminate having the above-mentioned layer structure, a molded article of the organic layer 5 having a predetermined shape is previously formed by injection molding or extrusion molding, and the inorganic barrier layer 1 is formed on one surface by the above-described vapor deposition means. And then forming the moisture absorbing layer 3 on the other surface of the organic layer 5 by coating. In this case, the moisture absorbing layer 3 may be formed on one surface of the organic layer 5 and then the inorganic barrier layer 1 may be formed on the other surface of the organic layer 5.

Further, since the inorganic barrier layer 1 is formed on the surface of a predetermined plastic substrate by vapor deposition, the following layer structure is also possible.
(High moisture atmosphere side): plastic substrate / inorganic barrier layer 1 / organic layer 5 / moisture absorbing layer: (low moisture atmosphere side)
In the above-mentioned layer structure, the plastic substrate can be formed of various thermoplastic resins or thermosetting resins similar to the resin capable of forming the organic layer 5, and an oxygen barrier layer formed of a gas barrier resin can be used. Of course, it is also possible to adopt a multilayer structure including the same.
In the case of such a layer structure, an inorganic barrier layer 1 is formed on the surface of a plastic base material formed into a shape (generally, a plate shape or a film or sheet shape) according to the application. On top of this, the organic layer 5 and the moisture absorbing layer 3 can be formed by coating in this order. The thickness and the like of such a plastic substrate may be set in an appropriate range according to characteristics (for example, flexibility, flexibility, strength, and the like) according to the use.
In addition, injection or co-injection molding, extrusion or co-extrusion, film or sheet molding, compression moldability, cast polymerization, etc. are employed as the means for molding the plastic substrate, depending on the form.

Further, in the present invention, the moisture absorbing layer 3 is sandwiched by the two inorganic barrier layers 1a and 1b in order to effectively avoid deterioration of the moisture absorbing layer 3 during storage until the moisture absorbing layer 3 is mounted on a predetermined device or the like. It can have a layered structure.
(High moisture atmosphere side): plastic substrate / inorganic barrier layer 1 / organic layer 5 / moisture absorbing layer 3 / adhesive layer / inorganic barrier layer 1b / plastic substrate: (low moisture atmosphere side)
In such a layer structure, the inorganic barrier layer 1b and the plastic substrate on the low moisture atmosphere side may be the same as the inorganic barrier layer 1a and the plastic substrate on the high moisture atmosphere side. Further, as the adhesive, an acid-modified olefin resin, a urethane-based resin, or the like can be used.
According to the method described above, such a sandwich-structured moisture barrier laminate has a laminate of plastic substrate / inorganic barrier layer 1 / organic layer 5 / moisture absorbing layer 3 (high moisture atmosphere) disposed on the high moisture atmosphere side. Side laminate) and a laminate on the low moisture atmosphere side (inorganic barrier layer 1b / plastic substrate), and these laminates can be bonded together with an adhesive.

  Further, the moisture barrier laminate having the sandwich structure as described above is manufactured by forming the above-described high moisture atmosphere side laminate, and then forming the inorganic barrier layer 1b on the moisture absorbing layer 3 by vapor deposition. In this case, it is preferable to form an underlayer having a predetermined thickness on the moisture absorbing layer 3 and then form the inorganic barrier layer 1b on the underlayer by vapor deposition. That is, the moisture absorbing layer 3 is poor in smoothness because it blocks moisture by absorbing moisture. If an inorganic barrier layer is formed directly on the inorganic barrier layer by vapor deposition, it loses adhesiveness and delaminates. And the like, and the inconvenience that the hygroscopic ability of the hygroscopic layer 3 is deteriorated due to heating or the like at the time of vapor deposition. However, by forming the underlayer as described above, the adhesion to the inorganic barrier layer 1b can be ensured, and at the same time, the performance deterioration of the moisture absorbing layer 3 can be effectively avoided by vapor deposition.

  Such an underlayer may be basically formed of the same kind of resin as the organic layer 5 described above, but is not for diffusing moisture, and thus has a thickness required for the organic layer 5. Is not necessary, as long as it has a thickness of at least about 0.1 μm.

Of course, the moisture barrier laminate of the present invention is not limited to the above-described layer structure. For example, various layers can be laminated on the moisture absorbing layer 3 of the high moisture atmosphere side laminate. In addition, a structure in which two or more inorganic barrier layers 1 are further laminated can be used, and further, the inorganic barrier layer 1 and the moisture absorbing layer 3 can be formed. Can be further enhanced. When a plurality of moisture absorbing layers 3 and inorganic barrier layers 1 are respectively formed, the above-described organic layer 5 may be provided between each of the moisture absorbing layers 3 and the inorganic barrier layer 1 located on the high moisture atmosphere side. This is suitable for maximizing the performance of the moisture absorbing layer 3.
Those skilled in the art will readily understand that such a multilayer moisture barrier laminate can be manufactured according to the method described above.

  The layer formed of the various resins described above may contain a resin compounding agent known per se, for example, an antioxidant, a lubricant, or the like, as long as the barrier property against moisture is not impaired.

In producing the moisture barrier laminate having the above-described various structures, the moisture absorbing layer 3 uses a coating composition obtained by dissolving or dispersing a particulate moisture absorbing agent in a predetermined solvent in a polymer serving as a matrix. The composition is formed by, for example, applying the composition on the organic layer 5 and drying to remove the solvent.
In the moisture absorbing layer 3 formed in this manner, an ionic polymer is suitably used as a matrix polymer, and a crosslinking agent is blended in order to effectively prevent the release of moisture absorbed and prevent deformation due to swelling. However, it is desirable to introduce a crosslinked structure into the matrix of the ionic polymer as described above.

  The composition of the coating composition for forming the moisture-absorbing layer 3 may be either a case where the matrix is formed of a cationic polymer (hereinafter, simply referred to as a “cationic matrix”) or a case where the matrix is formed of an anionic polymer ( Hereinafter, simply referred to as “anionic matrix”), the preferred composition is described separately for a cationic matrix and an anionic polymer.

In the case of a cationic matrix;
In such a coating composition, the cationic polymer and the particulate hygroscopic agent are used in the above-mentioned ratio. That is, the particulate hygroscopic agent is incorporated into the coating composition together with the cationic polymer in the amount described above with respect to 100 parts by weight of the cationic polymer.

  In the above-mentioned coating composition, a crosslinking agent for introducing a crosslinked structure into the hygroscopic matrix of the cationic polymer described above is appropriately blended, and depending on the type of the crosslinking agent, for example, a siloxane structure or a crosslinked structure may be used. By introducing a polyalicyclic structure, a network structure of a space suitable for absorbing moisture is formed.

Examples of the crosslinking agent in this case include a crosslinkable functional group (for example, an epoxy group) capable of reacting with a cationic group and a functional group (for example, alkoxysilyl) capable of forming a siloxane structure in a crosslinked structure through hydrolysis and dehydration condensation. A compound having the following formula (1):
X-SiR ¹ _n (OR ² ) _3-n (1)
In the formula, X is an organic group having an epoxy group at a terminal,
R ¹ and R ² are each a methyl group, an ethyl group, or an isopropyl
Group,
n is 0, 1, or 2;
The silane compound represented by is preferably used.

The silane compound of the formula (1) has an epoxy group and an alkoxysilyl group as functional groups, and the epoxy group undergoes an addition reaction with a functional group (for example, NH ₂ ) of the cationic polymer. On the other hand, the alkoxysilyl group generates a silanol group (SiOH group) by hydrolysis, forms a siloxane structure through a condensation reaction, and grows, thereby finally forming a crosslinked structure between the cationic polymer chains. As a result, a crosslinked structure having a siloxane structure is introduced into the matrix of the cationic polymer.
Moreover, since the coating composition contains a cationic polymer, it is alkaline. As a result, the addition reaction between the cationic group and the epoxy group and the dehydration condensation between the silanol groups are promptly promoted.

In the present invention, a typical example of the organic group X having an epoxy group in the above formula (1) is a γ-glycidoxyalkyl group, such as γ-glycidoxypropyltrimethoxysilane and γ-glycidoxysilane. Propylmethyldimethoxysilane is preferably used as a crosslinking agent.
Further, those in which the epoxy group in the above formula (1) is an alicyclic epoxy group such as an epoxycyclohexyl group are also suitable as the crosslinking agent. For example, when a compound having an alicyclic epoxy group such as β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane is used as a cross-linking agent, the alicyclic ring is included in the cross-linked structure of the matrix together with the siloxane structure. A structure is introduced. The introduction of such an alicyclic structure can more effectively exert the function of the matrix of forming a network structure of a space suitable for absorbing moisture.

Further, in order to introduce an alicyclic structure into the crosslinked structure, a compound having a plurality of epoxy groups and alicyclic groups, for example, the following formula (2):
GO (C = O) -A- (C = O) OG (2)
Wherein G is a glycidyl group;
A is a divalent hydrocarbon group having an aliphatic ring, for example, a cycloalkylene group.
,
Can be used as a crosslinking agent. A typical example of such a diglycidyl ester is represented by the following formula (2-1).

  That is, the diglycidyl ester of the formula (2) does not have an alkoxysilyl group, but forms a network structure of a space suitable for moisture absorption in a matrix because an alicyclic structure is introduced into a crosslinked structure. It is effective.

In the coating composition in the case of such a cationic matrix, the above-mentioned crosslinking agent is desirably used in an amount of 5 to 60 parts by weight, particularly 15 to 50 parts by weight, per 100 parts by weight of the cationic polymer. It is desirable that at least 70% by weight or more, preferably 80% by weight or more of such a crosslinking agent is the silane compound of the above formula (1).
If the amount of the cross-linking agent is too large, the handling properties may be impaired due to brittleness in mechanical strength, or it may not be possible to secure an effective pot life with a quick increase in viscosity when made into a paint, and if the amount is too small, Accordingly, there is a possibility that resistance (for example, mechanical strength) when exposed to a severe environment (for example, high humidity) may not be secured.

  The solvent used in the coating composition containing the various components described above is not particularly limited as long as it can be volatilized and removed by heating at a relatively low temperature, and includes, for example, alcohols such as methanol, ethanol, propyl alcohol, and butanol. Aqueous solvents, ketone solvents such as acetone and methyl ethyl ketone, or mixed solvents of these solvents and water, or water, aromatic hydrocarbon solvents such as benzene, toluene and xylene can be used. In order to accelerate the hydrolysis of the silane compound having an alkoxysilyl group in the crosslinking agent therein, it is desirable to use water or a mixed solvent containing water.

The solvent described above is used in such an amount that the coating composition has a viscosity suitable for coating. However, for adjusting the viscosity of the coating composition or adjusting the water absorption of the formed hygroscopic matrix to an appropriate range. , A nonionic polymer may be added in an appropriate amount.
Examples of such nonionic polymers include polyvinyl alcohol, ethylene-propylene copolymer, saturated aliphatic hydrocarbon-based polymer such as polybutylene, styrene-based polymer such as styrene-butadiene copolymer, polyvinyl chloride, or These include various comonomers (for example, styrene monomers such as vinyltoluene, vinylxylene, chlorostyrene, chloromethylstyrene, α-methylstyrene, α-halogenated styrene, α, β, β′-trihalogenated styrene, Monoolefins such as ethylene and butylene, and conjugated diolefins such as butadiene and isoprene) are copolymerized.

In the case of an anionic matrix;
In the coating composition for forming the moisture-absorbing layer 3 in this case, the anionic polymer and the particulate moisture-absorbing agent are used such that the amount of the particulate moisture-absorbing agent per 100 parts by weight of the anionic polymer is in the range described above. , Are incorporated into the coating composition.

Also in this coating composition, as in the case of the above-described cationic matrix, a crosslinking agent is appropriately blended.
As the cross-linking agent, a compound having two or more cross-linkable functional groups (for example, epoxy groups) capable of reacting with the ionic group of the anionic polymer can be used. Formula (2) also mentioned in the coating composition of:
GO (C = O) -A- (C = O) OG (1)
Wherein G is a glycidyl group;
A is a divalent hydrocarbon group having an aliphatic ring, for example, a cycloalkylene group.
,
The diglycidyl ester represented by the following formula is preferably used.

That is, in the diglycidyl ester of the above formula (2), the epoxy group reacts with the anionic group, and a crosslinked structure including an alicyclic structure due to the divalent group A is formed in the matrix. Such a crosslinked structure containing an alicyclic structure provides swelling suppression.
In particular, among the above-mentioned diglycidyl esters, preferable ones are also mentioned above. In particular, from the viewpoint that a network structure of a space suitable for moisture absorption can be formed, the diglycidyl ester is represented by the above formula (2-1). Diglycidyl esters are most preferred.

  In such a coating composition for an anionic matrix, the crosslinking agent is preferably used in an amount of 1 to 50 parts by weight, particularly 10 to 40 parts by weight, per 100 parts by weight of the anionic polymer. If the amount of the cross-linking agent is too large, there is a risk that the mechanical strength becomes brittle and the handling property is impaired, or when a paint is used, the viscosity increases and it is not possible to secure an effective pot life, and when the amount is too small, Accordingly, there is a possibility that resistance (for example, mechanical strength) when exposed to a severe environment (for example, high humidity) may not be secured.

  The solvent used in the coating composition containing the various components described above is not particularly limited as long as it can be volatilized and removed by heating at a relatively low temperature, and may be any of those mentioned in the coating composition for the cationic matrix. The same type can be used.

  Further, an alkali (for example, sodium hydroxide) can be added to the above-mentioned coating composition for an anion matrix for pH adjustment. For example, an alkali is added so that the pH becomes about 8 to 12. Good to do.

  The solvent described above is used in an amount such that the coating composition has a viscosity suitable for coating, like the coating composition for the cationic matrix, and is used for adjusting the viscosity of the coating composition or for forming the hygroscopic matrix. In order to adjust the water absorption to a suitable range, the above-mentioned nonionic polymer can be blended in a suitable amount.

  The formation of the moisture-absorbing layer 3 using the above-described coating composition for forming a cationic matrix or for forming an anionic matrix is performed by applying the above-described coating composition to the surface of the organic layer 5, and heating at about 80 to 160 ° C. This is done by heating to a temperature. The heating time depends on the capability of a heating device such as a heating oven, but is generally from several seconds to several minutes. By this heating, the solvent is removed, and the crosslinking agent reacts with the ionic polymer to form the moisture absorbing layer 3 having the crosslinked structure introduced into the matrix.

The thickness of the moisture-absorbing layer 3 formed as described above is not particularly limited, and can be set to an appropriate thickness according to the application and the required degree of moisture barrier. In order to exhibit a super-barrier property such that the water vapor permeability becomes 10 ⁻⁵ g / m ² / day or less, it is sufficient that the layer has a thickness of at least 1 μm or more, particularly about 2 to 20 μm.
Such a moisture absorbing layer 3 has a dual function of absorbing and confining moisture, and at the same time, the organic layer 5 prevents local degradation of the moisture absorbing layer 3 due to moisture passing through the defect X of the inorganic barrier layer 1. Since it is suppressed, the super-barrier property against moisture can be stably exhibited for a long period of time only by forming the moisture trap layer 5 having an appropriate thickness on the organic layer 5. Therefore, in the present invention, a high barrier property can be obtained by reducing the number of layers, which is extremely advantageous in terms of productivity, production cost, and the like.

<Application>
In the moisture barrier laminate of the present invention, the formation of the organic layer 5 effectively suppresses local deactivation of the excellent moisture trapping ability of the moisture absorbing layer 3 and maintains the moisture barrier property for a long period of time. Alternatively, when the moisture absorbing layer 3 is formed using the above-described ionic polymer, a dimensional change due to moisture absorption of the moisture absorbing layer 3 is prevented, and a decrease in adhesion due to the dimensional change (causing a decrease in barrier property) is also prevented. It is effectively avoided, and a super-barrier property against moisture having a water vapor permeability of 10 ⁻⁵ g / m ² / day or less can be stably realized with a small number of layers.

  Such a moisture barrier laminate 10 of the present invention can be suitably used as a film for sealing various electronic devices, for example, electronic circuits such as organic EL elements, solar cells, and electronic paper. The inorganic barrier layer 1 and the organic layer 5 are on the high moisture atmosphere side (specifically, the atmosphere side) with respect to the moisture absorbing layer 3, and the other side of the moisture absorbing layer 3 is on the low moisture atmosphere side (specifically, the device side). Thus, it can be attached to various devices, exhibit excellent moisture barrier properties, effectively avoid charge leakage due to moisture, etc., for example, for protection of organic EL light emitting elements and photovoltaic elements of solar cells. Can also be used.

  The excellent performance of the gas barrier laminate of the present invention will be described with reference to the following experimental examples.

<Measurement of moisture permeability (g / m ² / day)>
According to ASTM-F1249, using a moisture permeability measuring device (“Permatran-W” manufactured by Modern Control), set in a measuring cell such that the organic layer 5 is located on the higher moisture atmosphere side than the moisture absorbing layer 3, The measurement was performed at a temperature of 40 ° C. and a relative humidity of 90%. (Measurement limit = 0.01 g / m ² / day)

<Determination of water vapor transmission coefficient of organic layer resin>
The moisture permeability of each organic layer resin was measured by the above-described method, and the obtained value was normalized by a numerical value around 1 mm of the thickness of the organic layer resin, which was defined as the water vapor transmission coefficient of the organic layer resin.

<Long-term stability evaluation>
In the above-mentioned moisture permeability measurement, ◎ indicates that the performance was maintained for 100 hours or more, ○ indicates that the performance was maintained for 50 hours or more, and X indicates that the moisture permeability increased in less than 50 hours.

<Preparation of polyethylene terephthalate (PET) film coated with inorganic barrier layer 1>
An inorganic barrier layer 1 of silicon oxide was formed on one surface of a biaxially stretched PET film 6 having a thickness of 100 μm using a plasma CVD apparatus. The film forming conditions are shown below.
A high frequency output power supply having a frequency of 27.12 MHz and a maximum output of 2 kW, a matching box, a metal-type cylindrical plasma processing chamber having a diameter of 300 mm and a height of 450 mm, and a CVD apparatus having an oil rotary vacuum pump for evacuating the processing chamber were used. A plastic substrate was placed on a parallel flat plate in the processing chamber, and after introducing 3 sccm of hexamethyldisiloxane and 45 sccm of oxygen, a high frequency was oscillated at a power of 50 W by a high frequency oscillator to form a film for 2 seconds, thereby forming an adhesion layer. did.
Next, a high frequency was oscillated by a high frequency oscillator at an output of 200 W, and a film was formed for 15 seconds to form a barrier layer. The obtained inorganic barrier layer-coated PET film has a water vapor transmission rate of 0.1 g / m ² / day measured in an atmosphere of 40 ° C. and 90% RH.

<Example 1>
The following polyallylamine (cationic polymer) and a moisture absorbent were prepared as the ionic polymer and the moisture absorbent.
Polyallylamine;
Nitto Bo Medical PAA-15C (aqueous solution)
Solid content: 15% by weight
Hygroscopic agent;
Crosslinked product of sodium polyacrylate Toyufactuated by Toyobo HU-820E (water dispersion product)
Solid content: 13% by weight

The above-mentioned polyallylamine as an ionic polymer was diluted with water to a solid content of 5% by weight to obtain a polymer solution.
On the other hand, a crosslinking agent solution was prepared by using γ-glycidoxypropyltrimethoxysilane as a crosslinking agent and dissolving it in water to a concentration of 5% by weight.
Next, the polymer solution and the crosslinking agent solution were mixed so that γ-glycidoxypropyltrimethoxysilane was 15 parts by weight with respect to 100 parts by weight of polyallylamine. (A crosslinked product of sodium polyacrylate) was added in an amount of 400 parts by weight based on polyallylamine, and further adjusted with water so that the solid content became 5% by weight, followed by stirring well, and the mixture was used for a water trap layer. A coating liquid A was prepared.

  The coating liquid A obtained above was applied by a bar coater to the side opposite to the deposition surface of the PET film coated with the inorganic barrier layer prepared earlier. The coated film was heat-treated in a box-type electric oven under the conditions of a peak temperature of 120 ° C. and a peak temperature holding time of 10 seconds to form a 4 μm-thick moisture-absorbing layer 3 to obtain a coating film A.

  Then, in a glove box adjusted to a nitrogen concentration of 99.95% or more, the PET film coated with an inorganic barrier layer was placed on the coating layer of the coating film A via a urethane-based adhesive layer 7 having a thickness of 4 μm. Is dry-laminated so that the inorganic barrier layer 1 is on the inside, and aging is performed under vacuum at 50 ° C. for 3 days to cure the adhesive resin layer so as not to absorb moisture. The laminate 10 was obtained.

<Example 2>
A laminated laminate 10 having the layer structure shown in FIG. 2 was obtained in the same manner as in Example 1 except that the thickness of the polyethylene terephthalate (PET) film coated with the inorganic barrier layer 1 was changed to 12 μm. .

<Example 3>
In the same manner as in Example 1, except that a commercially available evaporated PET film (manufactured by Mitsubishi Plastics, Tech Barrier Type HX) formed by a PVD method was used instead of the inorganic barrier layer-coated PET film. A laminate having the layer structure shown in FIG. 2 was obtained.

<Example 4>
The coating liquid A obtained as described above was applied to the vapor-deposited surface of the PET film coated with the inorganic barrier layer prepared above using a bar coater. The coated film was heat-treated in a box-type electric oven under the conditions of a peak temperature of 120 ° C. and a peak temperature holding time of 10 seconds to form a 4 μm-thick moisture-absorbing layer 3 to obtain a coating film B.

  Next, in a glove box adjusted to a nitrogen concentration of 99.95% or more, the urethane-based adhesive layer 7 having a thickness of 4 μm and the EVOH film 8 having a thickness of 12 μm (Kuraray, EF) were formed on the coating layer of the coating film B. -F), a urethane-based adhesive layer 7 having a thickness of 4 μm, and a PET film coated with an inorganic barrier layer previously prepared are sequentially dry-laminated with the inorganic barrier layer 1 inside, and an adhesive resin layer so as not to absorb moisture. Was cured under vacuum at 50 ° C. for 3 days to obtain a laminate 11 having a layer structure as shown in FIG.

<Example 5>
In Example 4, a laminated laminate having the layer structure shown in FIG. 3 was obtained in the same manner as in Example 4, except that a biaxially stretched nylon film having a thickness of 15 μm was used instead of the EVOH film having a thickness of 12 μm. Was.

<Example 6>
In Example 4, a laminated laminate having the layer structure shown in FIG. 3 was obtained in the same manner as in Example 4, except that a 60 μm-thick unstretched polypropylene film was used instead of the 12 μm-thick EVOH film. .

<Example 7>
In Example 4, the urethane-based adhesive layer 7 having a thickness of 10 μm and the PET film coated with the inorganic barrier layer previously formed were dried on the coating layer of the coating film B such that the inorganic barrier layer 1 was on the inside. Lamination and aging were performed under vacuum at 50 ° C. for 3 days to cure the adhesive resin layer so as not to absorb moisture, thereby obtaining a laminate 12 having a layer structure as shown in FIG.

<Comparative Example 1>
In the moisture permeability measurement of Example 1, the measurement was performed in a direction in which the organic layer 5 of the laminate 11 was disposed on the lower moisture atmosphere side than the moisture absorbing layer 3.

<Comparative Example 2>
A laminated laminate was obtained in the same manner as in Example 7, except that the thickness of the urethane-based adhesive layer 7 was changed to 2 μm.

<Evaluation test>
Various characteristics of the sample laminate manufactured as described above were measured by the methods described above, and the results are shown in Table 1.

1: Inorganic barrier layer 3: Moisture absorbing layer 5: Organic layer 6: PET film 7: Urethane-based adhesive layer 8: EVOH film 10, 11, 12: Laminate laminate

Claims (5)

A moisture barrier laminate having an inorganic barrier layer and a moisture absorbing layer, wherein the inorganic barrier layer is disposed on the high moisture atmosphere side with respect to the moisture absorbing layer.
An organic layer having a thickness of 10 μm or more is interposed between the moisture absorbing layer and the inorganic barrier layer ,
The inorganic barrier layer is a vapor-deposited film, and has a moisture permeability of 0.1 g / m ² / day or less under a condition of a temperature of 40 ° C. and a relative humidity of 90% ;
The moisture barrier resin laminate , wherein the organic layer has a thickness three times or more the thickness of the moisture absorbing layer . The moisture barrier resin laminate according to claim 1, wherein the organic layer has a moisture diffusion function and is provided adjacent to the moisture absorbing layer. The moisture barrier resin laminate according to claim 2, wherein the organic layer has a water vapor transmission coefficient of 2.0 g · mm / m ² · day / atm or less. The moisture barrier resin laminate according to any one of claims 1 to 3, wherein the organic layer contains a polyester resin or an olefin-based resin. Water vapor permeability of the laminate, the moisture barrier of any one of claims 1-4, which is maintained below 50 hours or more 0.01g ^/ m 2 · day ^/ atm at a condition of temperature 40 ° C. and 90% relative humidity Resin laminate.