JP2017035829A - Moisture barrier laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture barrier laminate including an inorganic barrier layer and a moisture absorption layer, capable of suppressing effectively deactivation of the moisture absorption layer, and showing barrier property excellent to moisture stably over a long period.SOLUTION: In a moisture barrier laminate having an inorganic barrier layer 1 and a moisture absorption layer 3, in which the inorganic barrier layer 1 is arranged on the high-moisture atmosphere side with respect to the moisture absorption layer 3, an organic layer 5 having a thickness of 10 μm or more is interposed between the moisture absorption layer 3 and the inorganic barrier layer 1.SELECTED DRAWING: Figure 1

Description

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

  As a means for improving the characteristics 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, in various electronic devices that have been developed and put to practical use in recent years, such as organic electroluminescence (organic EL), solar cells, touch panels, electronic papers, etc. A high moisture barrier property is required for a plastic substrate such as a film for sealing the substrate or the circuit board. Since the formation of the inorganic barrier layer described above cannot meet such a high demand for moisture barrier properties, various proposals for improving the moisture barrier properties 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 oxide and carbon nanotubes are dispersed as a hygroscopic agent is provided on the inorganic barrier layer. Gas barrier laminates have been proposed.
Patent Document 3 proposes a gas barrier laminate (film) in which an organic layer, an inorganic barrier layer, and a water catching layer are formed on a base film, and the water catching layer is composed of a hygroscopic polymer (film). Specifically, it is disclosed that it is formed from a polyamide) or is formed by dispersing a hygroscopic material such as silica gel or aluminum oxide in a polymer binder such as an electron beam or an ultraviolet curable resin.
Further, Patent Document 4 includes a gas barrier film layer and a moisture absorption layer formed by vapor deposition on the surface of a plastic substrate, and the moisture absorption layer contains alkylene oxide, acrylate nanoparticles, or an organometallic complex. A gas barrier laminate has been proposed.

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

  Thus, in order to enhance the moisture barrier property to a high degree, various laminates having a layer structure combining an inorganic barrier layer and a moisture absorbing layer (water capturing layer) have been proposed. There is a problem that the deactivation of the water occurs in a short period of time, and the excellent moisture barrier property is not sufficiently exhibited.

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

  Accordingly, 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 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 conducted many experiments on the deactivation of the moisture absorption layer, and as a result of repeated studies, this deactivation is derived from defects such as cracks locally generated in the inorganic barrier layer, This defect has led to the knowledge that moisture permeates the inorganic barrier layer locally and the moisture absorption layer is locally deactivated, and the present invention has been completed based on this knowledge.

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

In the moisture barrier laminate of the present invention,
(1) The organic layer has a moisture diffusing function and is provided adjacent to the moisture absorbing layer.
(2) The organic layer exhibits 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 of 3 times or more with respect to the moisture absorption 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 hygroscopic layer, but has a basic structure in which the inorganic barrier layer is disposed on the high moisture atmosphere side with respect to the hygroscopic layer. . That is, when this laminate is attached to a device such as an organic EL, an inorganic barrier layer is disposed on the atmosphere side with respect to the moisture absorption layer. Therefore, the moisture absorption layer is located inside the device with respect to this inorganic barrier layer. Will be located on the side. For this reason, moisture has a structure that permeates from the inorganic barrier layer side toward the moisture absorption 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 hygroscopic layer. Can be effectively suppressed and can exhibit stable and excellent moisture barrier properties over a long period of time.

For example, a moisture absorption layer is provided between two inorganic barrier layers (silicon oxide deposition layers) having a water vapor permeability of 0.1 g / m ² · day / atm, and this moisture absorption layer and one inorganic barrier are provided. When a laminated body in which an organic layer (PET layer) having a thickness of 100 μm is provided between the layers and the moisture barrier property of this laminated body is evaluated, it is shown in Examples and Comparative Examples described later. As described above, the following results are obtained (refer to the examples for measurement of moisture permeability and the like).
That is, in the above laminate, one organic barrier layer faces a high humidity atmosphere (relative humidity 90%), and the other inorganic barrier layer faces a low humidity atmosphere (relative humidity 0%). Is disposed on the low humidity side with respect to the moisture absorption layer (Comparative Example 1). In this case, water vapor passes through the inorganic barrier layer, the moisture absorption layer, the organic layer, and the inorganic barrier layer in this order, and flows directly from the inorganic barrier layer to the moisture absorption layer. The moisture permeability of the laminated body thus arranged 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. To do.
On the other hand, according to the present invention, when the organic layer is arranged so as to be located on the high humidity side with respect to the hygroscopic layer (Example 1), water vapor is an inorganic barrier layer / organic layer / hygroscopic layer / inorganic. It permeates in the order of the barrier layer, and 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 way makes it possible to maintain a barrier property of less than 0.01 g / m ² · day / atm for 100 hours or more, greatly improving long-term stability. Has improved.

  Thus, in this invention, it becomes possible to exhibit the outstanding moisture barrier property by setting it as the layer structure that water vapor | steam flows into a moisture absorption layer through an organic layer from an inorganic barrier layer. Therefore, the moisture barrier laminate of the present invention is effectively used for various devices that dislike moisture intrusion, is useful as a substrate or a sealing layer for various devices, and is particularly suitable for an organic electroluminescence (organic EL) panel. Applies to

It is explanatory drawing for demonstrating the principle of the moisture barrier property expression in the moisture barrier property laminated body of this 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. FIG. 6 shows a layer structure of a moisture barrier laminate 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 absorption layer. A thick organic layer (10 μm or more) is provided on the high moisture atmosphere side. That is, the moisture (water vapor) in the high moisture atmosphere that has passed through the inorganic barrier layer flows through the organic layer to the moisture absorbing layer and is captured by the moisture absorbing layer. The reason why the moisture barrier property is greatly improved by such a structure is that a thick organic layer existing between the inorganic barrier layer and the moisture absorption layer functions as a moisture diffusion layer.

Please refer to FIG. 1 for illustrating this principle.
For example, in FIG. 1A, the moisture absorption 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 indicated by an arrow. It flows in layer 3.
By the way, an inorganic barrier layer is an inorganic vapor deposition film formed by physical vapor deposition, chemical vapor deposition, etc., and is formed by various metals and metal oxides, and shows a high barrier property against moisture. However, it inevitably contains fine defects such as pinholes and cracks. This defect is indicated by X in the figure.
Accordingly, in FIG. 1A, the amount of moisture flowing into the moisture absorption layer 3 through the defect X is large. Therefore, in the moisture absorption layer 3, the portion facing the defect X is faster than the other portions. It will be saturated and the moisture barrier property will deteriorate. 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 lowered.

  On the other hand, according to the present invention, as shown in FIG. 1B, when the thick organic layer 5 is provided between the inorganic barrier layer 1 and the hygroscopic layer 3, the inorganic barrier layer 1 Moisture passing through the defect X flows into the organic layer 5 and flows into the hygroscopic layer 3 through the organic layer 5. That is, in this case, the water flowing into the organic layer 5 from the defect X is diffused in the organic layer 5 because the organic layer 5 has an appropriate thickness, and as a result, dispersed in the surface direction of the organic layer 5. In this state, it flows into the moisture absorption layer 3. As a result, as shown in FIG. 1 (a), the inconvenience that the moisture flows locally and concentrates on the moisture absorption layer 3 is effectively avoided.

Such an effect of improving 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 water vapor transmission is very locally concentrated. When the thick organic layer 5 is not provided between the inorganic barrier layer 1 and the hygroscopic layer 3, the moisture passing through the defect X of the inorganic barrier layer 1 is concentrated extremely locally in the hygroscopic layer 3. Will flow into. That is, since only a small part of the moisture absorption layer 3 contributes to moisture absorption and most of the moisture absorption layer 3 does not contribute to moisture absorption, the moisture barrier property is further deteriorated. By providing the organic layer 5 having an appropriate thickness between the inorganic barrier layer 1 and the hygroscopic layer 3, as shown in FIG. Therefore, the entire structure functions stably as a trap layer for damming moisture and exhibits excellent moisture barrier properties.

<Inorganic barrier layer 1>
In the present invention having the basic structure described above, the inorganic barrier layer 1 located on the high moisture atmosphere side is formed by physical vapor deposition represented by sputtering, vacuum vapor deposition, ion plating, etc., or chemical vapor deposition represented by plasma CVD. It is an inorganic vapor deposition film formed by, for example, a film formed of various metals or metal oxides, but it is particularly formed evenly on uneven surfaces, not only for moisture but also for oxygen, etc. A vapor deposition film formed by plasma CVD is preferable in that it exhibits excellent barrier properties.
In addition, such an inorganic barrier layer 1 is formed on a predetermined plastic base material. However, the plastic base material may be the organic layer 5 having the moisture diffusing function described above. It may be different. When the plastic substrate is different from the organic layer 5, after the inorganic barrier layer 1 is formed, the organic layer 5 is formed thereon.

The vapor deposition film (inorganic barrier layer 1) formed by plasma CVD includes a metal that forms a film or a metal that forms a film by disposing a plastic substrate that supports the inorganic barrier layer in a plasma processing chamber maintained at a predetermined degree of vacuum. Compound gas (reaction gas) and oxidizing gas (usually oxygen or NOx gas) are shielded by a metal wall with a carrier gas such as argon or helium, as appropriate, and sealed to a predetermined vacuum level. In this state, a glow discharge is generated by a microwave electric field or a high-frequency electric field, and a plasma is generated by the electric energy. The decomposition reaction product of the compound is applied to the surface of the plastic substrate. It is obtained by depositing and forming a film.
In the case of using a microwave electric field, film formation is performed by irradiating a microwave into the plasma processing chamber using a waveguide or the like. 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.

  The reaction gas is generally an organometallic compound from the viewpoint that a film having a flexible region containing a carbon component on the surface of a plastic substrate and 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 organoaluminum compound such as trialkylaluminum, an organic titanium compound, an organozirconium compound, or an organosilicon compound. In particular, the inorganic barrier layer 1 having a high barrier property against oxygen is relatively easily and efficiently used. Organosilicon compounds are most preferred because they can be formed well.

  Examples of such organosilicon compounds include hexamethyldisilane, vinyltrimethylsilane, methylsilane, dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, methyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane. , Tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane and other organic silane compounds, octamethylcyclotetrasiloxane, 1,1,3,3-tetramethyldisiloxane, hexamethyl Organic siloxane compounds such as disiloxane are used. Besides these, aminosilane, silazane and the like can also be used.

  In addition, the organometallic compound mentioned above can be used individually or in combination of 2 or more types.

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

That is, organic groups (CH ₃ , CH _2, etc.) contained in the molecule of the organometallic compound are usually volatilized as CO ₂ , but at low output, some of them are not decomposed to CO ₂ , and plastic It accumulates on the surface of the substrate and is contained in the film. On the other hand, as the output is increased, the organic group is decomposed to CO ₂ . Therefore, by increasing the output, it becomes possible to reduce the C content in the film and form a film having a high degree of oxidation of the metal contained in the organometallic compound. However, a film having a high degree of oxidation of metal has a very high barrier property against gases such as oxygen, but is not flexible and has insufficient adhesion to a plastic substrate, whereas the degree of oxidation of metal is low. A film having a high organic component content does not have sufficient barrier properties against gas, but is highly flexible and exhibits high adhesion to a plastic substrate.

  As can be understood from the above description, in the present invention, an organometallic compound is used as a reaction gas, and film formation is performed at a low output in the initial stage of film formation by plasma CVD, and then the output is increased. As a result, a highly adhesive region 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 having 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 = O / M atomic ratio) in order to ensure excellent gas barrier properties. It is preferable to include a high oxidation degree region having an oxidation degree x of 1.5 to 2.0. In addition, on the lower side of the high oxidation degree region (the side in contact with the surface of the plastic substrate), the carbon (C) concentration is 20 on the basis of 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).

  In addition, it is preferable that the said high oxidation degree area | region in the inorganic barrier layer 1 exists in the ratio of 60% or more of the whole thickness of the inorganic barrier layer 1, and the said organic area | region is 5 of the whole thickness of the inorganic barrier layer 1. It is preferably formed on the surface of the plastic substrate and the contact side with a thickness of about 40%.

The glow discharge output when the inorganic barrier layer 1 having the organic region and the high oxidation region described above is formed by plasma CVD is slightly different between the case of using microwaves and the case of using high frequencies. For example, in the case of microwaves, the organic region is formed with a low output of about 30 to 100 W, and in the high oxidation region, the film is formed with 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 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 is within the above-described range.

In addition, the overall thickness of the inorganic barrier layer 1 described above varies depending on the use of the moisture barrier laminate and the required level of barrier properties, but generally the characteristics of the plastic substrate such as the organic layer 5 are impaired. The thickness should be sufficient to ensure a water vapor permeability of 10 ⁻² g / m ² · day / atom or less, particularly 10 ⁻³ g / m ² · day / atom or less. Generally, the thickness should be about 4 to 500 nm, particularly about 30 to 400 nm, although it depends on the proportion of the temperature region.

<Hygroscopic layer 3>
The moisture absorption layer 3 in the moisture barrier laminate of the present invention can also be referred to as a moisture trap layer, and may be a layer known per se, such as one in which a particulate moisture absorbent is dispersed in a predetermined resin layer.
In particular, when high barrier properties against moisture are required, for example, Patent Documents 5 to 7 describe, for example, from the viewpoint of excellent moisture scavenging properties and effectively avoiding deformation such as swelling due to moisture absorption. As described above, a layer in which the particulate adsorbent is dispersed in the ionic polymer is preferable.

The ionic polymer forms a matrix of the moisture absorption layer 3, and includes a cationic polymer having a cationic group (such as NH ₂ group) as an ionic group and an anionic group (COONa group) as an ionic group. , COOH group, etc.), and the particulate adsorbent generally has a lower reachable humidity than the ionic polymer.

That is, in the moisture absorption layer 3 using the ionic polymer as a matrix, a trace amount of water flowing through the inorganic barrier layer 1 is absorbed by the matrix (ionic polymer). Since the matrix itself exhibits high hygroscopicity, moisture is captured and absorbed without leakage.
By the way, when moisture is merely absorbed by the matrix, the absorbed moisture is easily released due to environmental changes such as a temperature rise. In addition, the penetration of moisture widens the intervals between the polymer molecules forming the matrix, and as a result, the hygroscopic layer 3 swells.
However, when a particulate adsorbent having a lower reached humidity than the matrix (ionic polymer) is dispersed, the moisture absorbed in the matrix is more hygroscopic than the matrix (ie, the reached humidity is lower). ) It is further captured by the hygroscopic agent, and not only is the swelling caused by the absorbed water molecules effectively suppressed, but the water molecules are confined in the hygroscopic layer 3, and as a result, the moisture from the hygroscopic layer 3 is trapped. Release is also effectively prevented.

  Thus, in the case where the hygroscopic layer 3 is formed by dispersing the particulate adsorbent in the ionic polymer, since it has a dual function of moisture capture and confinement as well as high hygroscopic capability, Moisture can be trapped even in a low-humidity atmosphere, and is not leaked to the outside in order to capture moisture at a rate sufficiently faster than the rate at which moisture permeates the inorganic barrier layer and to capture moisture throughout the layer. A high moisture barrier property can be realized.

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

Examples of cationic polymers include allylamine, ethyleneimine, vinylbenzyltrimethylamine, amine monomers such as [4- (4-vinylphenyl) -methyl] -trimethylamine, vinylbenzyltriethylamine; vinylpyridine, vinylimidazole, and the like. At least one cationic monomer typified by a nitrogen-containing heterocyclic monomer; and salts thereof; is optionally polymerized or copolymerized with another copolymerizable monomer; 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, 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, such as styrene, bromobutyl styrene, vinyl toluene, chloromethyl styrene, vinyl pyridine, vinyl A cationic polymer can also be obtained by using imidazole, α-methylstyrene, vinylnaphthalene, or the like, followed by treatment such as amination or alkylation (quaternary ammonium chloride) after polymerization.

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

The polymerization for forming the cationic polymer is generally carried out by radical polymerization by heating using a polymerization initiator.
The polymerization initiator is not particularly limited, but octanoyl peroxide, lauroyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, t-butylperoxide. Typical examples are organic peroxides such as oxylaurate, t-hexylperoxybenzoate, and di-t-butyl peroxide. Generally, anionic or cationic monomers (or anionic groups or cationic groups) are used. A monomer capable of introducing a group) is used in an amount of 0.1 to 20 parts by weight, particularly 0.5 to 10 parts by weight, based on 100 parts by weight.

  By carrying out the polymerization as described above, a cationic polymer is obtained. When a monomer capable of introducing a cationic functional group is used, amination, alkylation treatment, etc. are performed after the polymerization. A cationic group introduction treatment may be performed.

In the present invention, introduction of a crosslinked structure into the matrix formed using the above-described cationic polymer ensures mechanical strength without reducing hygroscopic capacity and at the same time improves dimensional stability. This is preferable.
That is, if a cross-linked structure is introduced into the hygroscopic matrix, when the matrix absorbs water, the molecules of the cationic polymer are bound to each other by cross-linking, and the volume change due to swelling (water absorption) is prevented. Suppression, resulting in improved mechanical strength and dimensional stability.
The above crosslinked structure can be introduced by blending a crosslinking agent in the coating composition for forming the moisture absorbing layer 3.

Ionic polymers (anionic polymers);
In the present invention, the anionic polymer used for forming the hygroscopic matrix has 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, and 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 supplements water by hydrogen bonding.
The amount of the anionic functional group in the anionic polymer varies depending on the type of the functional group, but the moisture absorption rate of the formed hygroscopic matrix (JIS K-7209-1984) is 80% humidity as in the above-described cationic polymer. 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 the above functional group include carboxylic acid monomers such as methacrylic acid, acrylic acid, and maleic anhydride; α-halogenated vinyl sulfonic acid, styrene sulfonic acid, vinyl sulfonic acid, and the like. Sulfonic acid-based monomers of the above; phosphonic acid-based monomers such as vinyl phosphoric acid; and salts of these monomers; Those obtained by polymerizing or copolymerizing with the above monomers and, if necessary, partially neutralized by alkali 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, acrolein. , Methyl vinyl ketone, vinyl biphenyl and the like.

  Further, instead of using the anionic monomer, an ester of the anionic monomer or a monomer having a functional group capable of introducing an anionic functional group, such as styrene, vinyl toluene, vinyl, etc. Using xylene, α-methylstyrene, vinylnaphthalene, α-halogenated styrenes, etc., after polymerization, treatment such as hydrolysis, sulfonation, chlorosulfonation, phosphoniumation, etc. can be performed to obtain an anionic polymer .

  In the present invention, a suitable anionic polymer is poly (meth) acrylic acid and a partially neutralized product thereof (for example, a part of which is a Na salt).

The polymerization for forming the anionic polymer described above is generally performed by radical polymerization by heating using a polymerization initiator.
The polymerization initiator is not particularly limited, but octanoyl peroxide, lauroyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, t-butylperoxide. Organic peroxides such as oxylaurate, t-hexyl peroxybenzoate, and di-t-butyl peroxide are typical, and in general, the above-mentioned anionic monomer (or a single amount capable of introducing an anionic group) Body) It is used in an amount of about 0.1 to 20 parts by weight, particularly about 0.5 to 10 parts by weight per 100 parts by weight.

  An anionic polymer is obtained by carrying out the polymerization as described above. However, when a monomer capable of introducing an anionic functional group is used, hydrolysis, sulfonation, chlorosulfonation is carried out after the polymerization. An anionic group introduction treatment such as phosphoniumation may be performed.

In the present invention, it is particularly preferable to introduce a cross-linked structure into the hygroscopic matrix formed using the anionic polymer described above, whereby the moisture trapping capability of the hygroscopic layer 3 is further enhanced, In addition, the dimensional stability is further improved.
That is, in the case of an anionic polymer, unlike a cationic polymer, water is only captured by hydrogen bonds, and therefore, by introducing a network structure (crosslinked structure) of a space suitable for moisture absorption into the matrix, the hygroscopicity is improved. It can be greatly increased. Such a crosslinked structure has, for example, a hydrophobic site such as an alicyclic structure in the network structure, and thereby the moisture absorption effect of the hydrophilic site is further enhanced.
Furthermore, by introducing a cross-linked structure into the hygroscopic matrix, when the matrix absorbs water, the anionic polymer molecules are constrained to each other by cross-linking, suppressing volume changes due to swelling (water absorption), and dimensional stability Improves. Such an effect of improving dimensional stability is the same as that of the cationic polymer described above.

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

Granular hygroscopic agent;
The particulate hygroscopic agent dispersed in the hygroscopic layer 3 having the above ionic polymer as a matrix (hygroscopic matrix) has a lower reached 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 higher hygroscopicity than the matrix in this way, the moisture absorbed in the matrix formed by the ionic polymer described above is immediately captured by the hygroscopic agent, and the absorbed moisture enters the matrix. In this case, the moisture absorption capability can be effectively exhibited even in an extremely low humidity atmosphere, and the swelling of the moisture absorption layer 3 due to moisture absorption is also effectively suppressed.

  As a highly hygroscopic particulate hygroscopic agent as described above, on the condition that the ultimate humidity is lower than that of the ionic polymer, for example, as shown in the examples described later, the humidity is 80% RH and the temperature is 30 ° C. Those having an ultimate humidity under environmental conditions of 6% or less are preferably used. In other words, if the humidity reached by the hygroscopic agent is higher than that of the ionic polymer, the moisture absorbed in the matrix is not sufficiently confined, and the release of moisture is likely to occur, so that a significant improvement in moisture barrier properties cannot be expected. End up. Moreover, 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, moisture trapping in a low humidity atmosphere becomes insufficient, and moisture barrier properties May not be fully utilized.

The granular hygroscopic agent as described above generally has a water absorption rate of 50% or more (JIS K-7209-1984) in an atmosphere of 80% humidity and 30 ° C., and there are inorganic and organic types. .
Examples of inorganic hygroscopic agents include clay minerals such as zeolite, alumina, activated carbon, and montmorillonite, silica gel, calcium oxide, and magnesium sulfate.
Examples of the organic hygroscopic agent 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 phosphones. Listed are those obtained by polymerizing or copolymerizing at least one of an anionic monomer represented by an acid monomer (such as vinyl phosphoric acid) and salts of these monomers with other monomers. be able to. In particular, in applications where transparency is required, organic moisture absorbents are effective. For example, fine particles of crosslinked poly (meth) acrylic acid Na are typical organic moisture absorbents.

In the present invention, a hygroscopic agent having a small particle size is preferable from the viewpoint of high specific surface area and high hygroscopicity (for example, an average primary particle size of 100 nm or less, particularly 80 nm or less), and particularly an organic system having a small particle size. A polymeric hygroscopic agent is optimal.
That is, the organic polymer hygroscopic agent has a very good dispersibility in the matrix of the ionic polymer and can be uniformly dispersed, and as a polymerization method for producing this, emulsion polymerization, suspension polymerization, etc. By adopting, the particle shape can be made into a fine and uniform spherical shape, and by mixing this to a certain extent, extremely high transparency can be ensured.
In addition, in the organic fine moisture absorbent, the above-mentioned reached humidity is remarkably low, and not only shows high hygroscopicity, but also volume change due to swelling can be extremely reduced by cross-linking, and therefore, while suppressing the volume change, It is most suitable for reducing the humidity to the place where the environmental atmosphere is completely dry or near dry.
As such organic hygroscopic fine particles, for example, crosslinked polyacrylic acid Na fine particles (average particle diameter of about 70 nm) in the form of a colloidal dispersion (pH = 10.4), Tufic HU-820E from Toyobo Co., Ltd. It is commercially available under the trade name.

In the present invention, the amount of the particulate hygroscopic agent as described above exhibits its characteristics sufficiently, effectively improves the moisture barrier property and effectively suppresses the dimensional change due to swelling, and at the same time exhibits the barrier property exhibited by the inorganic barrier layer 1. From the viewpoint of securing a higher moisture barrier property over a long period of time, it is set according to the type of ionic polymer.
For example, the hygroscopic layer 3 in which the above-described ionic polymer is used as a matrix and the particulate adsorbent is dispersed in the matrix is, when the matrix is formed of a cationic polymer, the ionic polymer in the hygroscopic layer 3. It is preferably present in an amount of 50 parts by weight or more, particularly 100 to 900 parts by weight, more preferably 200 to 600 parts by weight per 100 parts by weight. Further, 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 absorption layer 3, Is more preferably 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 hygroscopic layer 3 disposed on the high moisture atmosphere side basically has moisture permeability as compared with the hygroscopic 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 absorption layer 3. .
As described above, unavoidable defects X such as pinholes and cracks are generated in the inorganic barrier layer 1, and moisture concentrates locally on the moisture absorption layer 3 through the defects X. Therefore, there is a disadvantage that the moisture barrier property of the hygroscopic 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 hygroscopic layer 3. Therefore, a small amount of moisture that has passed through the defects X of the inorganic barrier layer 1 is transmitted through the organic layer 5 while diffusing in the surface direction, and as a result, moisture is evenly distributed over the entire surface direction of the moisture absorption layer 3. Inflow, the entire moisture-absorbing layer 3 exhibits a moisture trapping property, and the disadvantage that the moisture barrier property is locally degraded can be effectively avoided.
For example, when the thickness of the organic layer 5 is thinner than the above range, the moisture flowing in from the defect X permeates and flows into the moisture absorbing layer 3 with almost no diffusion in the surface direction. It becomes 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 in the adhesive resin layer. Therefore, local deterioration of the moisture absorption layer 3 cannot be avoided.

  Such an organic layer 5 can be made of a known thermoplastic or thermosetting resin as long as it is not less than a certain thickness as described above. From the viewpoints of low density polyethylene, high density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene or α-olefins such as ethylene, propylene, 1-butene, 4-methyl-1-pentene Random or block copolymers such as polyolefins, cyclic olefin copolymers, etc., and ethylene / vinyl compound copolymers such as ethylene / vinyl acetate copolymers, ethylene / vinyl alcohol copolymers, ethylene / vinyl chloride copolymers Polymer, polystyrene, acrylonitrile / styrene copolymer, ABS, α-methylstyrene / styrene Polystyrene compounds such as styrene copolymers, polyvinyl chloride, polyvinylidene chloride, vinyl chloride / vinylidene chloride copolymers, polyvinyl compounds such as polymethyl acrylate and polymethyl methacrylate, nylon 6, nylon 6-6, nylon 6-10, polyamides such as nylon 11, nylon 12, etc., thermoplastic polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate (PEN), polycarbonate, polyphenylene oxide and others, polyimide resin, polyamideimide Examples include resins, polyetherimide resins, fluororesins, allyl resins, polyurethane resins, cellulose resins, polysulfone resins, polyethersulfone resins, ketone resins, amino resins, or 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 on the condition that the total thickness is equal to or greater than a certain thickness (10 μm or more, particularly 20 μm or more). 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. Is possible. Furthermore, 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 to use a layer having 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 moisture (water vapor) flowing through the defects 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 local deterioration of the moisture absorption layer 3 can be effectively suppressed.

  In the present invention, from the viewpoint of availability, cost, moldability, moisture diffusibility, etc., the organic layer 5 is a polyester resin represented by polyethylene terephthalate (PET), or an olefin resin represented by polyethylene or polypropylene. It is optimal to form by.

<Layer structure and production of moisture barrier laminate>
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 interposed between the inorganic barrier layer 1 and the moisture absorbing layer 3. Various layer structures can be adopted under the condition that the basic structure of 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 / moisture absorption layer: (low moisture atmosphere side)

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

Moreover, since the inorganic barrier layer 1 is formed by vapor deposition on the surface of a predetermined plastic substrate, the following layer structure is also possible.
(High moisture atmosphere side): Plastic substrate / Inorganic barrier layer 1 / Organic layer 5 / Hygroscopic layer: (Low moisture atmosphere side)
In the above 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. Of course, a multi-layer structure can also be used.
In the layer structure, an inorganic barrier layer 1 is formed on the surface of a plastic substrate formed into a shape (generally, a plate shape or a film or sheet form) according to the application, and the inorganic barrier layer 1 On top of this, the organic layer 5 and the hygroscopic layer 3 can be formed by coating in this order. The thickness and the like of the plastic substrate may be set within a suitable range of characteristics (for example, flexibility, flexibility, strength, etc.) according to the application.
The plastic substrate molding means may employ injection or co-injection molding, extrusion or co-extrusion molding, film or sheet molding, compression moldability, cast polymerization, etc., depending on the form.

Furthermore, in the present invention, the moisture absorbing layer 3 is sandwiched between the two inorganic barrier layers 1a and 1b in order to effectively avoid deterioration of the moisture absorbing layer 3 during storage until it is mounted on a predetermined device or the like. It can be a layered structure.
(High moisture atmosphere side): Plastic substrate / inorganic barrier layer 1 / organic layer 5 / moisture absorption 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. As the adhesive, an acid-modified olefin resin, a urethane resin, or the like can be used.
The moisture barrier laminate having such a sandwich structure is formed by a laminate of a plastic substrate / inorganic barrier layer 1 / organic layer 5 / moisture absorbing layer 3 (high moisture atmosphere) disposed on the high moisture atmosphere side in accordance with the method described above. Side laminate) and a laminate on the low moisture atmosphere side (inorganic barrier layer 1b / plastic base material), and these laminates can be produced by bonding them with an adhesive.

  Further, the moisture barrier laminate having the sandwich structure as described above is manufactured by forming the 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 inorganic barrier layer 1b on the underlying layer by vapor deposition after the underlying layer having a predetermined thickness is formed on the moisture absorbing layer 3. That is, the hygroscopic layer 3 has poor smoothness in connection with the fact that moisture is blocked by moisture absorption. If an inorganic barrier layer is directly formed on the hygroscopic layer by vapor deposition, the adhesiveness is lost, and the layer peeling occurs. In addition, the moisture absorption capability of the moisture absorption layer 3 deteriorates due to heating during vapor deposition. However, by forming the base layer as described above, it is possible to ensure adhesion to the inorganic barrier layer 1b and at the same time effectively avoid performance degradation of the moisture absorbing layer 3 by vapor deposition.

  Such an underlayer may basically be formed of the same kind of resin as the organic layer 5 described above, but is not for diffusing moisture, and therefore has a thickness as required for the organic layer 5. Is not necessary, and it is sufficient that 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 layer structure described above. For example, various layers can be laminated on the moisture absorbing layer 3 of the high moisture atmosphere laminate, for example, In addition, a structure in which two or more inorganic barrier layers 1 are laminated can be formed, and further, the inorganic barrier layer 1 and the moisture absorption layer 3 can be formed. It can be further enhanced. Further, when a plurality of the moisture absorption layers 3 and the inorganic barrier layers 1 are formed, the organic layer 5 described above is provided between each of the moisture absorption 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 absorption 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.

  In addition, the layer formed with the various resins described above may contain a resin compounding agent known per se, for example, an antioxidant, a lubricant, and the like within a range not impairing the barrier property against moisture.

Further, when the moisture barrier laminate having the various structures described above is produced, the moisture absorbing layer 3 uses a coating composition in which a particulate moisture absorbent is dissolved or dispersed in a predetermined solvent in a matrix polymer. The composition is formed by, for example, applying the composition onto the organic layer 5 and drying to remove the solvent.
In the moisture absorption layer 3 thus formed, an ionic polymer is preferably used as a matrix polymer, and a crosslinking agent is blended in order to effectively avoid the release of moisture absorbed and prevent deformation due to swelling. However, as described above, it is desirable to introduce a crosslinked structure into the matrix of the ionic polymer.

  The composition of the coating composition for forming the hygroscopic layer 3 includes the case where the matrix is formed of a cationic polymer (hereinafter simply referred to as “cationic matrix”) and the case of being formed of an anionic polymer ( Hereinafter, the composition will be slightly different from that of the “anionic matrix”, and the preferred composition will be described separately for the cationic matrix and the 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 aforementioned quantitative ratio. That is, with respect to 100 parts by weight of the cationic polymer, the particulate hygroscopic agent is blended in the coating composition together with the cationic polymer in the amount described above.

  Further, in the above coating composition, a crosslinking agent for introducing a crosslinked structure into the hygroscopic matrix of the cationic polymer described above is appropriately blended. Depending on the type of the crosslinking agent, for example, the crosslinked structure has a siloxane structure or By introducing a polyalicyclic structure, a network structure of a space suitable for moisture absorption is formed.

In this case, the crosslinking agent includes a crosslinkable functional group that can react with a cationic group (for example, an epoxy group) and a functional group that can form a siloxane structure in the crosslinked structure through hydrolysis and dehydration condensation (for example, alkoxysilyl). Group) can be used, in particular 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 the terminal,
R ¹ and R ² are each a methyl group, an ethyl group, or isopropyl
Group,
n is 0, 1, or 2;
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, and forms a siloxane structure through a condensation reaction, and finally grows to form 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.
In addition, 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 rapidly promoted.

In the present invention, the organic group X having an epoxy group in the formula (1) is typically a γ-glycidoxyalkyl group, such as γ-glycidoxypropyltrimethoxysilane or γ-glycidoxy. Propylmethyldimethoxysilane is preferably used as the crosslinking agent.
Moreover, what the epoxy group in the said Formula (1) is an alicyclic epoxy group like an epoxy cyclohexyl group is also suitable as a 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. Structure is introduced. The introduction of such an alicyclic structure can more effectively exert the function of a matrix that forms a network structure of a space suitable for moisture absorption.

Furthermore, 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):
G-O (C = O) -A- (C = O) OG (2)
Where G is a glycidyl group;
A is a divalent hydrocarbon group having an aliphatic ring, for example, a cycloalkylene group.
The
The diglycidyl ester represented by these 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 introduces an alicyclic structure into the cross-linked structure, thereby forming a network structure of a space suitable for moisture absorption in the matrix. It is effective.

In the coating composition in the case of such a cationic matrix, the above-mentioned crosslinking agent is preferably used in an amount of 5 to 60 parts by weight, in particular 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 formula (1) described above.
If the amount of the crosslinking agent used is too large, the mechanical strength becomes brittle and handling properties are impaired, and there is a possibility that an effective pot life cannot be ensured because the viscosity increases quickly when made into a paint. In connection with this, there exists a possibility that the tolerance (for example, mechanical strength) when exposed to a severe environment (for example, under high humidity) cannot 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. For example, alcohols such as methanol, ethanol, propyl alcohol, and butanol An organic solvent, a ketone solvent such as acetone and methyl ethyl ketone, a mixed solvent of these solvents and water, or an aromatic hydrocarbon solvent such as water, benzene, toluene, and xylene. In order to promote hydrolysis of the silane compound having an alkoxysilyl group in the crosslinking agent, it is desirable to use water or a mixed solvent containing water.

The above-mentioned solvent 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 the water absorption rate of the formed hygroscopic matrix is in an appropriate range. Therefore, the nonionic polymer can be blended in an appropriate amount.
Examples of such nonionic polymers include polyvinyl alcohol, ethylene-propylene copolymers, saturated aliphatic hydrocarbon polymers such as polybutylene, styrene polymers such as styrene-butadiene copolymers, polyvinyl chloride, or These include various comonomers (for example, styrene monomers such as vinyl toluene, vinyl xylene, chlorostyrene, chloromethyl styrene, α-methyl styrene, α-halogenated styrene, α, β, β'-trihalogenated styrene, And monoolefins such as ethylene and butylene, and conjugated diolefins such as butadiene and isoprene).

In the case of an anionic matrix;
In the coating composition for forming the moisture-absorbing layer 3 in this case, the amount of the particulate hygroscopic agent with respect to 100 parts by weight of the anionic polymer is within the above-mentioned range. In the coating composition.

Also in this coating composition, as in the case of the cationic matrix described above, 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) that can react with an ionic group of an anionic polymer can be used. Formula (2) mentioned in the coating composition of:
G-O (C = O) -A- (C = O) OG (1)
Where G is a glycidyl group;
A is a divalent hydrocarbon group having an aliphatic ring, for example, a cycloalkylene group.
The
The diglycidyl ester represented by these is used suitably.

That is, in the diglycidyl ester of the above formula (2), an epoxy group reacts with an anionic group, and a crosslinked structure including an alicyclic structure with a divalent group A is formed in the matrix. Such a cross-linked structure including an alicyclic structure is used to suppress swelling.
Particularly preferred among the above-mentioned diglycidyl esters are listed above, and are represented by the above formula (2-1) from the viewpoint that a network structure of a space suitable for moisture absorption can be formed. Diglycidyl ester is most preferred.

  In such a coating composition for an anionic matrix, the cross-linking agent is desirably 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 crosslinking agent used is too large, the mechanical strength becomes brittle and handling properties are impaired, and there is a possibility that an effective pot life cannot be ensured because the viscosity increases quickly when made into a paint. In connection with this, there exists a possibility that the tolerance (for example, mechanical strength) when exposed to a severe environment (for example, under high humidity) cannot 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 is also mentioned in the coating composition for the cation matrix. The same kind can be used.

  Furthermore, an alkali (for example, sodium hydroxide) can be added to the coating composition for the anion matrix described above to adjust the pH. For example, the alkali is added so that the pH is about 8 to 12. It is good to do.

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

  Formation of the moisture absorption layer 3 using the coating composition for forming the cationic matrix or for forming the anionic matrix described above is performed by applying the coating composition described above to the surface of the organic layer 5 and about 80 to 160 ° C. This is done by heating to temperature. The heating time is generally several seconds to several minutes although it depends on the ability of a heating device such as a heating oven. By this heating, the solvent is removed, and further, the crosslinking agent reacts with the ionic polymer, so that the moisture absorbing layer 3 in which the crosslinked structure is introduced into the matrix can be formed.

In addition, the thickness of the moisture absorption layer 3 formed as described above is not particularly limited and can be set to an appropriate thickness depending on the use and the degree of moisture barrier required. In order to exhibit the super barrier property such that the water vapor transmission rate is 10 ⁻⁵ g / m ² / day or less, it is only necessary to have a thickness of at least 1 μm, particularly about 2 to 20 μm.
Such a moisture absorption layer 3 has a dual function of moisture absorption and confinement, and at the same time, the organic layer 5 causes local deterioration of the moisture absorption layer 3 due to moisture passing through the defect X of the inorganic barrier layer 1. Therefore, the super barrier property as described above can be stably exerted on moisture over a long period of time only by forming a 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 and production cost.

<Application>
In the moisture barrier laminate of the present invention, the formation of the organic layer 5 effectively suppresses local deactivation of the moisture trapping ability of the moisture absorbing layer 3, and the moisture barrier property is maintained for a long period of time. In the case where the hygroscopic layer 3 is formed using the ionic polymer described above, the dimensional change due to the hygroscopic absorption of the hygroscopic layer 3 is also prevented, and the adhesiveness is reduced due to the dimensional change (resulting in a decrease in barrier properties). It is effectively avoided, and it is possible to stably realize a super-barrier property against moisture with a water vapor permeability of 10 ⁻⁵ g / m ² / day or less 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 electronic circuits such as various electronic devices 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 air side) with respect to the hygroscopic layer 3, and the other side of the hygroscopic layer 3 is on the low moisture atmosphere side (specifically, the device side). Thus, it can be mounted on various devices, exhibit excellent moisture barrier properties, and can effectively avoid leakage of charges due to moisture, for example, for protection of organic EL light-emitting elements and solar cell photovoltaic elements. Can also be used.

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

<Measurement of moisture permeability (g / m ² / day)>
Prepared in accordance with ASTM-F1249, using a moisture permeability measuring device ("Permatran-W" manufactured by Modern Control Co., Ltd.), set the organic layer 5 in the high moisture atmosphere side than the moisture absorbing layer 3, Measurement was performed under conditions of 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-mentioned method, and the obtained value was normalized with a numerical value of the organic layer resin thickness around 1 mm as the water vapor transmission coefficient of the organic layer resin.

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

<Preparation of an inorganic barrier layer 1-coated polyethylene terephthalate (PET) film>
A silicon oxide inorganic barrier layer 1 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 source having a frequency of 27.12 MHz and a maximum output of 2 kW, a matching box, a metal 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 is placed on parallel plates in the processing chamber. After introducing 3 sccm of hexamethyldisiloxane and 45 sccm of oxygen, a high frequency is oscillated at a power of 50 W by a high frequency oscillator to form a film for 2 seconds to form an adhesion layer. did.
Next, a high frequency was oscillated with an output of 200 W by a high frequency oscillator, 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 hygroscopic agent were prepared as the ionic polymer and the hygroscopic agent.
Polyallylamine;
Nittobo Medical PAA-15C (aqueous solution)
Solid content: 15% by weight
Hygroscopic agent;
Polyacrylic acid Na cross-linked product Toyobo Tuftic HU-820E (water dispersion)
Solid content: 13% by weight

The above polyallylamine as an ionic polymer was diluted with water so as to have a solid content of 5% by weight to obtain a polymer solution.
On the other hand, γ-glycidoxypropyltrimethoxysilane was used as a crosslinking agent and dissolved in water so as to be 5% by weight to prepare a crosslinking agent solution.
Next, the polymer solution and the crosslinking agent solution are mixed so that γ-glycidoxypropyltrimethoxysilane is 15 parts by weight with respect to 100 parts by weight of polyallylamine, and the above-mentioned hygroscopic agent is further added to this mixed solution. (Cross-linked product of poly (acrylic acid Na)) is added so as to be 400 parts by weight with respect to polyallylamine, and further mixed with water so that the solid content is 5% by weight. Coating liquid A was prepared.

  The coating liquid A obtained above was applied to the opposite side of the vapor-deposited surface of the previously prepared inorganic barrier layer-coated PET film by 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 moisture absorption layer 3 having a thickness of 4 μm.

  Next, in the glove box adjusted to a nitrogen concentration of 99.95% or more, the inorganic barrier layer-coated PET film is formed on the coating layer of the coating film A via the urethane adhesive layer 7 having a thickness of 4 μm. 2 is laminated so that the inorganic barrier layer 1 is on the inside, and the adhesive resin layer is cured so as not to absorb moisture, so that it is aged at 50 ° C. for 3 days under vacuum, and has a layer structure as shown in FIG. A laminate 10 was obtained.

<Example 2>
In Example 1, a 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 inorganic barrier layer 1-coated polyethylene terephthalate (PET) film was 12 μm. .

<Example 3>
In Example 1, instead of the inorganic barrier layer-coated PET film, a vapor-deposited PET film (Mitsubishi Resin, Tech Barrier Type HX) formed by a commercially available PVD method was used. A laminate laminate having the layer structure shown in FIG. 2 was obtained.

<Example 4>
The coating liquid A obtained above was applied to the vapor-deposited surface of the previously prepared inorganic barrier layer-coated PET film by 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 moisture absorption layer 3 having a thickness of 4 μm, and a coating film B was obtained.

  Next, in a glove box adjusted to a nitrogen concentration of 99.95% or more, a 4 μm-thick urethane adhesive layer 7 and a 12 μm-thick EVOH film 8 (Kuraray, EF) are formed on the coating layer of the coating film B. -F), a urethane adhesive layer 7 having a thickness of 4 μm, an inorganic barrier layer-coated PET film previously prepared and dry laminated so that the inorganic barrier layer 1 is 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 laminate 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. It was.

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

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

<Comparative Example 1>
In the moisture permeability measurement of Example 1, the measurement was carried out in such a direction that the organic layer 5 of the laminate 11 is disposed on the low moisture atmosphere side of the moisture absorption layer 3.

<Comparative Example 2>
In Example 7, a laminate laminate was obtained in the same manner as in Example 7 except that the thickness of the urethane adhesive layer 7 was 2 μm.

<Evaluation test>
With respect to the laminate laminate of the sample prepared above, various characteristics were measured by the method described above, and the results are shown in Table 1.

1: Inorganic barrier layer 3: Hygroscopic layer 5: Organic layer 6: PET film 7: Layer of urethane adhesive 8: EVOH film 10, 11, 12: Laminated laminate

Claims (6)

In a moisture barrier laminate having an inorganic barrier layer and a moisture absorbing layer, the inorganic barrier layer being disposed on the high moisture atmosphere side with respect to the moisture absorbing layer,
A moisture barrier laminate, wherein an organic layer having a thickness of 10 μm or more is interposed between the moisture absorption layer and the inorganic barrier layer.   The moisture barrier laminate according to claim 1, wherein the organic layer has a moisture diffusing function and is provided adjacent to the moisture absorption layer. The moisture barrier laminate according to claim 2, wherein the organic layer exhibits a water vapor transmission coefficient of 2.0 g · mm / m ² · day / atm or less.   The moisture barrier laminate according to any one of claims 1 to 3, wherein the organic layer contains a polyester resin or an olefin resin.   The moisture barrier laminate according to any one of claims 1 to 4, wherein the organic layer has a thickness of 3 times or more of the moisture absorption layer. The moisture barrier laminate according to claim 1, wherein the laminate has a water vapor permeability of 0.01 g / m ² · day / atm or less.