JP4763552B2 - Clay thin film and laminated body thereof - Google Patents

Description

  The present invention relates to a clay thin film having a structure in which flaky inorganic materials are laminated and including a reactive fluid substance.

The display is rapidly changing from a conventional cathode ray tube system to a liquid crystal system (LCD) in terms of mobility and space saving. Furthermore, as a next-generation display, a self-luminous device that is excellent in terms of brightness, vividness, and power consumption is being produced. These are far superior in terms of mobility and space saving compared to the conventional CRT type, but because of the use of glass as a substrate, they are relatively heavy and have the problem of cracking. is doing.
In order to solve these problems, a film substrate (referred to as a “placel”) is used in some liquid crystal type devices. However, in the case of an organic EL display that has been in the spotlight as a next-generation display, a low-resistance transparent conductive film is required, and thus heat treatment exceeding 250 ° C. is indispensable. No conventional plastic substrate can withstand such heat treatment conditions. As a material that can satisfy these requirements, a clay thin film has attracted attention.

The clay thin film has transparency and excellent flexibility, and has a structure in which particles are densely oriented in layers, so it has excellent gas barrier properties and the main component is an inorganic substance. It is a material excellent in heat resistance (see Patent Document 1). However, there are some problems when used as a film substrate for liquid crystal or organic EL displays.
One is the problem of water resistance. Commonly used clay contains a hydrophilic cation between layers, and is a highly hygroscopic substance. For this reason, it is not suitable as a film substrate for an organic EL display in which deterioration due to moisture is a concern. One measure to increase water resistance is to add a water repellent between the layers. However, if water absorption is controlled, the film loses its flexibility when it loses water at all, and retains sufficient water to maintain flexibility. Attempting to do so results in the destruction of the film due to the boiling of water due to rapid overheating. As another water resistance method, there is a method of exchanging hydrophilic cations contained between clay layers with hydrophobic cations. However, in order to give flexibility to the clay film, it is necessary to insert a large amount of heat-sensitive resin between the clay layers, and there is a problem that the heat resistance of clay cannot be fully exhibited.
JP 2005-104133 A

  As described above, in order to use the clay thin film as a film substrate for an organic EL display, it is necessary to provide a thin film having flexibility with excellent transparency, heat resistance, and water resistance. Accordingly, an object of the present invention is to provide an excellent thin film having a structure in which flaky inorganic materials are laminated and having both a heat resistance, water resistance and flexibility by including a reactive fluid substance. It is in.

The clay thin film of the present invention has a structure in which flaky inorganic materials are oriented and laminated, and is a clay thin film containing a reactive fluid substance. Between the flaky inorganic layers, a quaternary ammonium salt, It contains at least one hydrophobic cationic substance selected from quaternary phosphonium salts, pyridinium salts, and imidazolium salts, and the reactive fluid substance is an epoxy-modified silicone oil. The film thickness is 1 to 3000 μm . The clay thin film of the present invention is formed, for example, by dispersing a flaky inorganic material and a reactive fluid substance in a solvent, forming the film into a film, and then peeling the film from the film after heat treatment. Obtainable. Examples of the flaky inorganic material may include mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, nontronite, magadiite, ilarite, kanemite, smectite, and layered titanic acid. . One or more of these can be used for the clay thin film. In addition, by silylating the clay as a flaky inorganic material with a silane coupling agent, a silane compound or the like in advance, effects such as improved compatibility with the reactive fluid substance described below and improved reactivity can be obtained. This is preferable.

The reactive fluid substance has a structure having a reactive functional group in the heat-resistant fluid substance. The heat-resistant fluid substance mentioned here is a liquid or paste-like substance that does not cause alteration such as decomposition and boiling even when heated at 200 ° C. or more, typified by lubricating oil. Examples include polyethylene glycol, polyalkylene glycol, phosphate ester, alkylbenzene, poly-α-olefin, polyol ester, alkylnaphthalene, silicone oil, halocarbon, polyarylalkane, polyphenyl, silicate ester, polyphenyl ether, and the like. The reactive fluid substance refers to one having a structure further having a reactive functional group among the heat-resistant fluid substances listed above, but the reactive fluid substance of the present invention is limited to epoxy-modified silicone oil.

In the present invention, the reactive fluid substance is an epoxy-modified silicone oil. The reactive fluid substance is preferably 1 to 60% of the entire clay thin film by weight. If it is less than 1%, the flexibility of the clay tends to be lost, and if it exceeds 60%, it becomes difficult to stand as a film. Here, epoxy-modified silicone oil introduces an epoxy group into a part of the methyl group of silicone oil, and has properties such as compatibility with organic substances, chemical reactivity, solubility in water, emulsifying properties and water repellency. This is what was granted. Epoxy groups play a role in imparting flexibility to a self-supporting film because the silicone oil that has fluidity becomes a rubbery or flexible material by chemical bonding and crosslinking of functional groups between silicone oils by curing agents and reaction aids. Can do. Specifically, for example, in a mixed system of a flaky inorganic material, an epoxy-modified silicone oil and an epoxy resin curing agent, or in a system in which an epoxy resin is mixed, the epoxy group of the epoxy-modified silicone oil reacts to form a silicone rubber property. It becomes a self-supporting film. In the case of addition of an epoxy resin, a crosslinking reaction is established with the resin, and a self-supporting film having higher strength and flexibility is obtained.

A resin can also be added to increase the strength of the clay thin film. Regarding the resin, it is preferable to use a resin having a functional group capable of chemically reacting with the reactive fluid substance. For example, various combinations such as an epoxy group-containing silicone oil and an epoxy resin are possible. By adding a resin having a functional group capable of chemically reacting with the reactive fluid substance, the resin has a cross-linked structure by chemically reacting with the reactive fluid substance, and as a result, the strength of the clay thin film is improved. To do. The resin having a functional group mentioned here is preferably 50% or less of the entire clay thin film by weight ratio. If it exceeds 50%, the ratio of the flaky inorganic material is lowered, and the heat resistance and gas barrier properties are likely to be lowered.

Further, the interlayer of the flaky inorganic material constituting the clay thin film of the present invention comprises a cationic substance having a hydrophobic, tends thereby contain reactive flow material in the clay layers. In general, clay contains hydrophilic exchangeable cations between layers. In the present invention, the hydrophilic exchangeable cation between the layers of the flaky inorganic material, which is clay, is exchanged with a hydrophobic cation substance to make it organic, thereby “organizing clay” . Examples of hydrophobic cationic substances include quaternary ammonium salts such as dimethylyl distearyl ammonium salt and trimethyl stearyl ammonium salt, ammonium salts having a benzyl group or a polyoxyethylene group, phosphonium salts, A pyridinium salt or an imidazolium salt can be used to make organic using the ion exchange property of clay, for example, the cation exchange property of montmorillonite. Thereby, dispersion | distribution to the organic solvent of a flaky inorganic material becomes easy, and inclusion of a reactive fluid substance becomes easy. Examples of the structure of the hydrophobic cationic material shown above are shown below.

（式中、Ｘはハロゲン元素、Ｒ１〜Ｒ１１はアルキル基を示す）

(In the formula, X represents a halogen element, and R1 to R11 represent an alkyl group)

The clay thin film of the present invention can be used alone as a free-standing film, but at least one of an inorganic thin film and an organic thin film on one or both sides of the clay thin film in order to obtain higher gas barrier properties, chemical resistance, and surface smoothness. It is possible to form a single layer or a plurality of layers. There are no particular limitations on the type of laminated film, but an optimum film can be selected depending on the application. As an inorganic thin film, for example, there is a method of forming silicon oxide, silicon oxynitride, silicon nitride, or the like by sputtering or plasma CVD, which can provide high gas barrier properties and chemical resistance. Furthermore, as an organic thin film, the surface can be made flat by applying an organic polymer to at least one surface of the clay thin film. By laminating these inorganic thin films or organic thin films on a clay thin film, it is possible to impart characteristics that cannot be obtained by a clay thin film alone.
Moreover, when producing the clay thin film of this invention, various general additives, such as a hardening adjuvant, antioxidant, surfactant, a pigment, and a leveling agent, can be added.

The clay thin film of the present invention has a structure in which flaky inorganic materials are laminated, and is an excellent thin film that has both heat resistance, water resistance and flexibility by including a reactive fluid substance.
In addition, the clay thin film of the present invention can be used for many products due to the above properties. For example, electronic paper substrate, electronic device sealing film, lens film, light guide plate film, prism film, retardation plate / polarizing plate film, viewing angle correction film, PDP film, LED film, optical communication Materials, touch panel films, substrates for various functional films, films for electronic devices with a transparent structure, video discs, CD / CD-R / CD-RW / DVD / MO / MD, phase change discs, optical cards Can be used for films for optical recording media, sealing films for fuel cells, films for solar cells, and the like.
Further, as shown in Example 8 below, when an additional function is provided by surface coating, a high gas barrier property can be realized, and it can be suitably used as a film substrate for liquid crystal and organic EL displays.

  Hereinafter, the best mode for carrying out the present invention will be described based on examples, but the present invention is not limited to these examples.

[Example 1]
(Organization of clay)
After 5 g of tetradecyltrimethylammonium bromide was dispersed in 50 g of pure water, 5 g of synthetic smectite (Kunimine Kogyo Co., Ltd., trade name: Smecton SA) was added and sufficiently dispersed and swollen. This solution was subjected to solid-liquid separation using a centrifuge to remove the liquid component, and then 50 g of pure water was further added for dispersion and solid-liquid separation. This dispersion / solid-liquid separation was repeated until no foaming occurred, and then the moisture was completely removed with a dryer. As a result, the hydrophilic exchangeable cation and tetradecyltrimethylammonium ion contained in the clay were exchanged to obtain an organized clay having swelling properties with respect to toluene which is a nonpolar solvent.

(Formation of clay thin film)
The organoclay obtained above is pulverized, 10 g of the organoclay is dispersed and swollen in 100 g of toluene, and an epoxy-modified dimethylphenyl silicone oil having an epoxy group (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22) 2000) 0.5 g, 0.25 g of an acid anhydride curing agent (trade name: Ricacid MH-700, manufactured by Shin Nippon Chemical Co., Ltd.) was added, and the dispersion was further continued. The obtained solution was applied onto a polyethylene terephthalate film (hereinafter referred to as PET film) that had been treated with an applicator to form a film. Then, it was put into a dryer at 100 ° C., the solvent content was removed, the PET film was peeled off, and the epoxy-modified silicone oil was crosslinked by heat treatment at 170 ° C./2 hours to obtain the clay thin film of the present invention. This clay thin film was a transparent and flexible thin material having a thickness of 80 μm.
[Example 2]

In Example 1, 5 g of epoxy-modified dimethylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22-2000), acid anhydride-based curing agent (manufactured by Shin Nippon Rika Co., Ltd., trade name: Ricacid MH-700) The clay thin film of the present invention having a thickness of 80 μm was obtained in the same manner except that 2.5) was changed to 2.5 g.
Example 3

In Example 1, 10 g of epoxy-modified dimethylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22-2000), acid anhydride curing agent (manufactured by Shin Nippon Rika Co., Ltd., trade name: Ricacid MH-700) ) Was replaced with 5 g in the same manner to obtain a clay thin film of the present invention having a thickness of 80 μm.
Example 4

A clay thin film of the present invention having a thickness of 80 μm was obtained in the same manner as in Example 1 except that 5 g of octadecyltriphenylphosphonium bromide was used instead of 5 g of tetradecyltrimethylammonium bromide.
[ Reference Example 5 ]

In Example 1, instead of 1 g of epoxy-modified dimethylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22-2000), amino-modified dimethylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22) -1660B-3) A clay thin film of the present invention having a thickness of 80 μm was obtained in the same manner except that 1 g was used.
Example 6

In the same manner as in Example 1 (formation of clay thin film), a thickness of 80 μm was similarly obtained except that 1 g of a thermosetting epoxy resin having a basic skeleton of bisarylfluorene (trade name: EX1020, manufactured by Nagase Sangyo Co., Ltd.) was added. A clay thin film of the present invention was obtained.
Example 7

An ultraviolet curable urethane acrylate (manufactured by Nippon Gosei Kagaku Co., Ltd., trade name: Violet UV7600B), which is a hard coat material, is applied to the front and back surfaces of the clay thin film prepared in Example 1 using a bar coater and cured by ultraviolet irradiation. Then, hard coat layers of 1 μm each on the front and back sides were laminated to obtain a clay thin film laminate of the present invention.
Example 8

On the front and back surfaces of the clay thin film produced in Example 1, a _Si O _x film, which is an inorganic layer, was laminated by a thickness of 60 nm by reactive sputtering to obtain a clay thin film laminate of the present invention.

[Comparative Example 1]
5 g of the same organized clay as in Example 1 was dispersed and swollen in 100 g of toluene, and the solution obtained without blending the reactive fluid substance was applied onto a PET film that had been treated with an applicator to form a film. did. Then, it put into the dryer of 100 degreeC, the solvent content was removed, and it peeled from PET film, and obtained the clay thin film for a comparison of thickness 80 micrometers.

[Comparative Example 2]
In Example 1, 1 g of dimethyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-54), which is a non-reactive fluid substance, was used instead of the epoxy-modified dimethylphenyl silicone oil. A comparative clay thin film having a thickness of 80 μm was obtained in the same manner except that it was not contained.

(Characteristic evaluation of clay thin film)
For the clay thin films prepared in Examples 1 to 8 and Comparative Examples 1 and 2 obtained as described above, the following characteristics were measured and the results are shown in Table 1.
(1) Flexibility [Appearance after bending]
After the clay thin film was wound around a cylindrical rod having a diameter of 15 mm and bent, the appearance was observed.
(2) Heat resistance [appearance after heating]
The appearance after the clay thin film was left in a thermostatic bath at 200 ° C. and 250 ° C. for 1 hour was observed.
[Linear expansion coefficient]
The linear expansion coefficient was measured according to ASTM-D696.
(3) Water resistance [water vapor permeability]
Using a gas / vapor permeability measuring device manufactured by GTR Tech Co., which is capable of measuring the permeability and moisture permeability of gases and vapors by a differential pressure type gas chromatography method according to JIS K7126 A method (differential pressure method), a temperature of 40 The water vapor transmission rate was measured under the conditions of ° C / humidity 90% RH.
(4) Transparency [total light transmittance]
The total light transmittance was measured using a haze meter (Haze Meter NDH2000, manufactured by Nippon Denshoku).

As is clear from the results in the above table, the clay thin films of Examples 1 to 8 of the present invention have flexibility without change in the appearance after bending, and have sufficient heat resistance without change even after heating at 200 ° C. It had the property. In addition, the clay thin films of Examples 1 to 8 of the present invention have a linear expansion coefficient of 33 ppm / ° C. or less, a good heat resistance in terms of dimensional stability, and a water vapor permeability of 0.8 g / m ^2. -Good water resistance below day, total light transmittance was 90% or more, and transparency was good.
In contrast, the clay thin film of Comparative Example 1 did not have flexibility due to cracking after bending. In addition, it was confirmed that the clay thin film of Comparative Example 2 had a linear expansion coefficient of 53 ppm / ° C. and insufficient heat resistance, so that the dimensional stability was poor and there was a problem in workability.

Claims (6)

A clay thin film having a structure in which flaky inorganic materials are oriented and laminated and containing a reactive fluid substance, and a quaternary ammonium salt, a quaternary phosphonium salt, and a pyridinium salt between the flaky inorganic layers A clay thin film comprising at least one hydrophobic cation substance selected from imidazolium salts, and wherein the reactive fluid substance is an epoxy-modified silicone oil. The flaky inorganic material is at least one of mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, nontronite, magadiite, ilarite, kanemite, smectite and layered titanic acid. The clay thin film according to claim 1. 2. The clay thin film according to claim 1 , wherein the content of the reactive fluid substance is 1 to 60% of the whole clay thin film in a weight ratio. The clay thin film contains a resin having a functional group, and the resin having the functional group and the reactive fluid substance react to form a cross-linked structure . The clay thin film according to item 1 . 5. The clay thin film according to claim 4 , wherein the content of the resin having a functional group is 50% or less of the entire clay thin film by weight ratio. A laminate comprising at least one of an inorganic thin film and an organic thin film laminated on one side or both sides of the clay thin film according to any one of claims 1 to 5 .