JP2003048271A - Transparent water vapor barrier film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent film which has a higher water vapor barrier performance than that of a prior art and in which the barrier performance is not deteriorated even by bending. SOLUTION: The transparent water vapor barrier film comprises an organic material layer (1), an inorganic material layer (1), an organic material layer (2), and an inorganic material layer (2) laminated in this order on a rein base. In this case, a thickness of the layer (2) is 0.01 μm to 3 μm.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a transparent film having a high water vapor barrier property, which can be applied to a wide range of applications such as optical members, electronic members, general packaging members, and chemical packaging members.

[0002]

2. Description of the Related Art Conventionally, a water vapor barrier film in which a thin film of a metal oxide such as aluminum oxide, magnesium oxide or silicon oxide is formed on the surface of a plastic substrate or a film is used for packaging an article which needs to block water vapor, It is widely used for packaging purposes to prevent the deterioration of foods, industrial supplies and pharmaceuticals. In addition to packaging applications, liquid crystal display devices, solar cells, electroluminescence (EL)
Used in substrates, etc. In recent years, the weight of transparent base materials, which have been increasingly applied to liquid crystal display elements, EL elements, etc.
In addition to the demand for larger size, high demands such as long-term reliability, high degree of freedom of shape, and ability to display curved surfaces are added, making it transparent instead of a glass substrate that is heavy and easily broken and difficult to increase in area. Film base materials such as plastics are beginning to be adopted. Further, the plastic film not only meets the above-mentioned requirements but also has the advantage of being more productive and cost-effective than glass since it can be used in a roll-to-roll system.

However, there is a problem that the film base material such as transparent plastic is inferior in water vapor barrier property to glass. When a base material having a poor water vapor barrier property is used, water vapor penetrates and deteriorates, for example, the liquid crystal in the liquid crystal cell, resulting in a display defect and deterioration in display quality. In order to solve such a problem, it is known to form a metal oxide thin film on a film substrate and use it as a gas barrier film substrate. As a water vapor barrier film used for a packaging material or a liquid crystal display device, a plastic film on which silicon oxide is vapor-deposited (Japanese Patent Publication No. 53-12953) or aluminum oxide is vapor-deposited (JP-A-58-217344). Gazette) is known, and all have a water vapor barrier property of about 1 g / m ² / day. In recent years, the demand for water vapor barrier performance on film substrates has increased to about 0.1 g / m ² / day due to the development of large liquid crystal displays and high-definition displays. In order to respond to this, as a means by which higher water vapor barrier performance can be expected, sputtering method and CV
Film formation studies by the D method are being conducted. However, in recent years, organic E has been required to have a further water vapor barrier property.
The development of L-displays and high-definition color liquid crystal displays is progressing, and there is a need for a base material that has a high water vapor barrier property of less than 0.1 g / m ² / day while maintaining the transparency that can be used. Has become. Furthermore, there is a great demand for a display device that can be bent, and a barrier layer that does not deteriorate the water vapor barrier performance even when bent has been required.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a transparent film which has a higher water vapor barrier performance than ever and does not deteriorate even when bent.

[0005]

Means for Solving the Problems That is, the present invention provides (1) a transparent water vapor barrier film comprising an organic material layer, an inorganic material layer, an organic material layer, and an inorganic material layer laminated in this order on a resin substrate, and the thickness of the organic material layer. Is 0.01 μm
The transparent water vapor barrier film having a thickness of 3 μm or less. (2) The transparent water vapor barrier film according to (1), wherein the organic material layer contains a polymer obtained by crosslinking a monomer having an acryloyl group as a main component. (3) The organic material layer has one or more kinds of monomers having a bifunctional or higher functional acryloyl group, or one or more kinds of monomers having a bifunctional or higher functional acryloyl group and one or more kinds of monomers having a monofunctional or higher functional acryloyl group. (1) A transparent water vapor barrier film, which comprises a polymer obtained by crosslinking a mixture of (4) The transparent water vapor barrier film according to (3), wherein the monomer having a bifunctional or higher functional acryloyl group is a bifunctional or higher functional isocyanuric acid acrylate, epoxy acrylate or urethane acrylate. (5) The transparent water vapor barrier film according to (1) to (4), wherein the inorganic layer contains silicon oxide, silicon nitride, or silicon nitride oxide as a main component. (6) The transparent water vapor barrier film according to (1) to (5), wherein the glass transition temperature of the resin substrate is 200 ° C. or higher. (7) The transparent water vapor barrier film according to (1) to (6), wherein the resin substrate has a norbornene-based resin or polyether sulfone as a main component. Is.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is not limited to the first layer (organic material layer, inorganic material layer) by stacking an organic material layer, an inorganic material layer, an organic material layer, and an inorganic material layer in this order on a resin substrate. It is a transparent film in which the defective portion of the layer structure is filled with a second layer (organic material layer, inorganic material layer) to improve the water vapor barrier property. Further, by setting the thickness of the inorganic material layer and the organic material layer sandwiched between the inorganic material layer and the inorganic material layer to be in the range of 0.01 to 3 μm, the barrier performance thereof is not deteriorated even when bent, and good adhesion of the inorganic material layer is obtained. . There is no limitation on the inorganic layer of the present invention, for example, Si, Al, In, Sn, Z
An oxide, a nitride, an oxynitride, or the like containing one or more of n, Ti, Cu, Ce, or the like can be used. If the inorganic layer is too thick, there is a risk of cracks due to bending stress, and if it is too thin, the film will be distributed in islands, and the water vapor barrier property will deteriorate in both cases. From the above, the thickness of each inorganic layer is preferably in the range of 5 nm to 500 nm, but is not particularly limited. Further, the respective inorganic layers may have the same composition or different compositions, and there is no limitation. In order to achieve both the water vapor barrier property and the high transparency, it is preferable to use silicon oxide or silicon oxynitride as the inorganic layer. Silicon oxide is referred to as SiOx. For example, when SiOx is used as the inorganic layer, 1.6 <x <1.9 is desirable in order to achieve both good water vapor barrier properties and high light transmittance. Silicon oxynitride is described as SiOxNy, but if the emphasis is on improving adhesion, the ratio of x and y should be an oxygen-rich film, with 1 <x <2 and 0 <y <1 being preferred, and water vapor barrier properties. When importance is placed on improvement, a nitrogen-rich film is preferably used, and 0 <x <0.8 and 0.8 <y <1.3 are preferable.

The material of the organic layer of the present invention is not particularly limited, but acrylic resin, urethane resin, polyester resin and the like can be used. Among them, among epoxy acrylates, urethane acrylates, isocyanuric acid acrylates, pentaerythritol acrylates, trimethylolpropane acrylates, ethylene glycol acrylates, polyester acrylates, etc., they are obtained by applying a monomer having a bifunctional or higher acryloyl group and then crosslinking it. It is preferable to use a polymer as the main component because the coatability is good. Particularly, it is preferable that the main component is isocyanuric acid acrylate, epoxy acrylate, or urethane acrylate, which has a high degree of crosslinking and a glass transition temperature of 200 ° C. or higher. These monomers having a bifunctional or higher functional acryloyl group may be used as a mixture of two or more kinds, or a monofunctional acrylate may be used as a mixture. In addition, PVA which is relatively barrier by itself
A system, EVA system, polyvinylidene chloride, or a plurality of these resins may be mixed. There is no particular limitation on the thickness of the organic material layer directly on the resin substrate,
0.01 to 10 μm is preferable. The resin base material of the present invention is not particularly limited, but polysulfone resin, polyether sulfone resin, polycarbonate resin, polyarylate resin, polyacrylate resin, polyester resin, polyamide resin, epoxy resin, polyimide resin, polyolefin resin, polychlorinated resin. Vinylidene resin or the like can be used. In particular, a norbornene-based resin having a glass transition temperature of 200 ° C. or higher and polyether sulfone are preferable because they have good optical characteristics and high heat resistance and are not deformed or deteriorated by high-temperature treatment in the organic layer / inorganic layer forming process.

[0008]

EXAMPLES Examples of the present invention will be described in detail below, but the present invention is not limited to the following examples. (Example 1) Bifunctional epoxy acrylate (Showa High Polymer: VR-60-LAV) 25 wt% on a polyether sulfone film,
A uniform mixed solution of 50 wt% of diethylene glycol, 24 wt% of ethyl acetate and 1 wt% of silane coupling agent was applied by a spin coater, dried by heating at 80 ° C. for 10 minutes, and further cured by UV irradiation to form a 2 μm resin layer. Next, set the film on which the organic material layer is formed in the vacuum chamber of the sputtering device and evacuate to a level of 10 ^-4 Pa, introduce argon as a discharge gas at a partial pressure of 0.04 Pa, and oxygen as a reaction gas at a partial pressure. Introduced 0.04Pa. When the atmospheric pressure became stable, discharge was started, plasma was generated on the Si target, and the sputtering process was started. When the process became stable, the shutter was opened and the formation of the SiOx inorganic film on the film was started. When the 50 nm film was deposited, the shutter was closed to complete the film formation. Then, the atmosphere was introduced into the vacuum chamber (1), and the film having the SiOx inorganic layer formed thereon was taken out.
Furthermore, on the SiOx inorganic film deposition surface of the film, acrylic resin (Showa High Polymer: VR-60-LAV) 25 wt%, diethylene glycol 50 wt%, ethyl acetate 24 wt%, silane coupling agent 1 wt
Apply a uniform mixed solution consisting of
After heating and drying at 0 ℃ for 10 minutes, it is further cured by UV irradiation to 0.5 μm
The resin layer of was formed. The film was set again in the vacuum tank of the sputtering apparatus, and the vacuum was evacuated to the level of 10 ⁻⁴ Pa. Argon was introduced as a discharge gas at a partial pressure of 0.04 Pa and oxygen was introduced as a reaction gas at a partial pressure of 0.04 Pa. When the atmospheric pressure became stable, discharge was started, plasma was generated on the Si target, and the sputtering process was started. When the process became stable, the shutter was opened and the formation of the SiOx inorganic film on the film was started. When the 50 nm film was deposited, the shutter was closed to complete the film formation. Then, the atmosphere was introduced into the vacuum chamber (1), and the film having the SiOx inorganic layer formed thereon was taken out.

(Example 2) The organic layer / inorganic layer / organic layer / inorganic layer was formed on the polyethersulfone film in the same manner as in Example 1, but the thickness of the organic layer sandwiched between the inorganic layers was Was 0.01 μm. (Example 3) An organic material layer / inorganic material layer / organic material layer / inorganic material layer was formed on a polyethersulfone film in the same manner as in Example 1, but in this embodiment, the thickness of the organic material layer was 3 μm. (Example 4) The polyether sulfone film was used in the same manner as in Example 1 except that isocyanuric acid triacrylate (Toagosei: Aronix M-315) was used in place of the bifunctional epoxy acrylate used in Example 1. An organic layer / inorganic layer / organic layer / inorganic layer was formed on the top.

Example 5 Example 1 was repeated except that the bifunctional epoxy acrylate used in Example 1 and isocyanuric acid triacrylate (Toagosei: Aronix M-315) were mixed in a ratio of 1: 1. In the same manner as above, formation of an organic material layer / inorganic material layer / organic material layer / inorganic material layer was performed on the polyether sulfone film. (Example 6) Formation of organic material layer / inorganic material layer / organic material layer / inorganic material layer on a polycarbonate film in the same manner as in Example 1 except that a polycarbonate film was used instead of the polyether sulfone film used in Example 1. I went.

Comparative Example 1 In the same manner as in Example 1, the organic layer / inorganic layer / organic layer / inorganic layer was formed on the polyethersulfone film. In this example, the thickness of the organic layer was 0.005. μm. And (Comparative Example 2) In the same manner as in Example 1, the organic layer / inorganic layer / organic layer / inorganic layer was formed on the polyether sulfone film. In this example, the thickness of the organic layer was 5 μm.

(Evaluation) The water vapor permeability of each film is determined by JISK
It was measured by the 7129B method. The appearance was visually evaluated. Furthermore, after being wound once around a 30 mmφ rod, the water vapor permeability was measured again by the JIS K7129B method. The results are shown in Table 1.

[0013]

[Table 1]

In each of Examples 1 to 6, all the evaluation results sufficiently satisfied the required characteristics for a display device, but in Comparative Example 1 in which the organic material layer was thin, a mottled pattern was generated on the surface. The water vapor permeability was slightly higher than that of the example. It is presumed that this is because the adhesion between the organic layer and the inorganic layer is poor in some places and the barrier property is also affected. Further, in Comparative Example 2 in which the thickness of the organic material layer was large, the barrier property and the appearance before the bending treatment were the same as those of the Examples, but the bending treatment greatly increased the water vapor permeability. It is considered that this is because the organic layer is destroyed and this affects both inorganic layers.

[0015]

INDUSTRIAL APPLICABILITY The present invention is a transparent film having a high water vapor barrier and has a characteristic that the water vapor barrier property is not deteriorated by bending. When the film of the present invention is applied as a display element, for example, a light and non-breakable display can be realized. In addition, if it is applied to the storage of chemicals, it is possible to realize a storage container whose contents can be seen and does not break when dropped, and its industrial value is extremely high.

Continued front page    F-term (reference) 4F100 AA01C AA01E AA20C AA20E                       AH00B AH00D AH06 AK01A                       AK01B AK01D AK02A AK25B                       AK25D AK54A AL05B AL05D                       AT00A BA05 BA07 BA10A                       BA10E CA02 EH46 EH462                       EH66 EH662 EJ24 EJ242                       EJ42 EJ422 EJ54 EJ542                       EJ86 EJ862 GB15 GB41                       GB66 JA05A JD04 JK17                       JN01

Claims (7)

[Claims] 1. An organic material layer, an inorganic material layer, and
In a transparent water vapor barrier film formed by laminating an organic material layer and an inorganic material layer in this order, the thickness of the organic material layer is 0.
A transparent water vapor barrier film having a thickness of 01 μm or more and 3 μm or less. 2. The transparent water vapor barrier film according to claim 1, wherein the organic material layer is mainly composed of a polymer obtained by crosslinking a monomer having an acryloyl group. 3. The organic layer comprises at least one kind of monomer having a bifunctional or higher functional acryloyl group, or at least one kind of monomer having a bifunctional or higher functional acryloyl group and a monofunctional or higher functional acryloyl group. The transparent water vapor barrier film according to claim 1, which comprises a polymer obtained by cross-linking a mixture with the above monomer as a main component. 4. The transparent water vapor barrier film according to claim 3, wherein the monomer having a bifunctional or higher functional acryloyl group is a bifunctional or higher functional isocyanuric acid acrylate, epoxy acrylate or urethane acrylate. 5. The inorganic layer mainly contains silicon oxide, silicon nitride or silicon nitride oxide.
The transparent water vapor barrier film according to any one of items. 6. The glass transition temperature of the resin base material is 200 ° C.
It is above, The transparent water vapor barrier film of any one of Claims 1-5. 7. The transparent water vapor barrier film according to claim 1, wherein the resin base material contains norbornene-based resin or polyether sulfone as a main component.