JP4583062B2 - Transparent gas barrier film and method for producing the same - Google Patents

Description

  The present invention relates to a transparent gas barrier film, and more particularly to a transparent gas barrier film excellent in flexibility, transparency, heat resistance, solvent resistance, gas barrier properties and interlayer adhesion. Light and crack that can be used to replace conventional glass substrates as display substrates such as display film substrates, lighting film substrates, solar cell film substrates, circuit board film substrates, and electronic paper. It relates to a support substrate that is not bent.

In the present specification, “ratio”, “part”, “%” and the like indicating the blending are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated.
In addition, “barrier” is “barrier”, “EL” is “electroluminescence”, “LCD” is “liquid crystal display”, “panel” is “element”, and “(meth) acrylate” is “aryre”. Abbreviations, functional expressions, common names, or industry terms.
According to the definition of film and sheet in JIS-K6900, a sheet is thin and generally refers to a flat product whose thickness is small relative to the length and width, and the film is extremely small compared to the length and width. , A thin flat product with an arbitrarily limited maximum thickness, usually supplied in the form of a roll. Therefore, it can be said that a sheet having a particularly thin thickness is a film, but the boundary between the sheet and the film is not clear and is difficult to distinguish clearly. Therefore, in this specification, the term “film” includes both the sheet and the film. Is defined.

(Background) Substrates in the field of electronic devices such as displays, lighting, solar cells, circuit boards, etc. include gas barrier properties, flexibility, transparency, heat resistance, solvent resistance, and interlayer adhesion. Many harsh physical properties are required.
For this reason, conventionally, only a substrate made of an inorganic material such as a Si wafer or glass could be used as the electronic device substrate. However, in recent years, a substrate made of a polymer material (hereinafter referred to as a polymer substrate) that has a light weight, a flexible substrate, low cost, handling characteristics, etc. and is light, does not crack, and can be bent is desired. In rare cases, the use of a synthetic resin sheet or a synthetic resin film in place of a glass substrate constituting a conventional display has been studied. In particular, for display applications such as organic EL and film liquid crystal, a transparent and heat-resistant polymer substrate is desired. However, the polymer substrate generally has a significantly high gas permeability when compared with a substrate made of an inorganic material such as glass. For this reason, an electronic device using a polymer substrate cannot maintain the required degree of vacuum in the electronic device, so that gas penetrates the polymer substrate and enters the electronic device, and the device is oxidized by the diffused oxygen. There is a problem such as deterioration, and for the purpose of extending the life of the display, a super barrier property of oxygen and water vapor from the outside is required.
Therefore, a transparent gas barrier film that has excellent gas barrier properties, is light, does not crack, is bent, and can be used for polymer substrates with total physical properties that can be replaced by glass substrates is flexible, transparent, heat resistant Many harsh physical properties such as properties, solvent resistance and interlayer adhesion, and particularly gas barrier properties such as water vapor and oxygen are required.

(Prior Art) Conventionally, in order to improve the adhesiveness between a resin film and a gas barrier layer, an adhesive layer is known (see, for example, Patent Document 1). However, no consideration is given to the suppression of pinholes in the gas barrier layer caused by protrusions present on the resin film surface. Therefore, the example of this publication has a problem that the water vapor permeability is 0.1 g / m ² and the gas barrier film is still insufficient for a gas barrier film for electronic devices.

JP 09-109314 A

Accordingly, the present invention has been made to solve such problems.
The purpose is to provide ultra-high gas barrier properties by flattening the protrusions even if the transparent resin base film has protrusions. Moreover, the transparent resin base film and the gas barrier layer It is to provide a transparent gas barrier film having improved adhesion and a method for producing the same.

To solve the above problem,
The method for producing a transparent gas barrier film according to the invention of claim 1 includes a transparent resin base film having a glass transition temperature Tg of 150 ° C. or higher and 300 ° C. or lower, and one or more on one surface of the transparent resin base film. In the method for producing a transparent gas barrier film having the above-mentioned layer, when forming at least one of the one or more layers, it is heated to 150 ° C. or higher after previously applying or immersing water or a hydrophilic solvent. The wet heating process is performed.
The method for producing a transparent gas barrier film according to the invention of claim 2 includes a transparent resin base film having a glass transition temperature Tg of 150 ° C. or higher and 300 ° C. or lower and a first transparent inorganic film on one surface of the transparent resin base film. A transparent gas barrier film provided with a compound layer, a transparent gas barrier film obtained by further providing a planarizing layer on the first transparent inorganic compound layer surface, and a second transparent inorganic compound layer further provided on the planarized layer surface A transparent gas barrier film, or a transparent resin substrate film having a glass transition temperature Tg of 150 ° C. or more and 300 ° C. or less, and a planarizing layer and a second transparent inorganic compound layer are provided on one surface of the transparent resin substrate film. In the method for producing a transparent gas barrier film, when the first transparent inorganic compound layer, the planarization layer and / or the second transparent inorganic compound layer is formed, a wet heating step is performed in advance. And, after the wet heat process was applied or soaked with water or hydrophilic solvent, to heat above 0.99 ° C., it is obtained by.
A transparent gas barrier film according to the invention of claim 3 is produced by the method for producing a transparent gas barrier film according to any one of claims 1 to 2, and the transparent resin base film and the transparent resin base The first transparent inorganic compound layer, the flattening layer and the second transparent inorganic compound layer, or the transparent resin base film on one surface of the material film, and the flattening layer and the second on one surface of the transparent resin base film In the transparent gas barrier film provided with the transparent inorganic compound layer, the light transmittance of the transparent resin substrate film is 80% or more, and the surface roughness Ra (average roughness) of the second transparent inorganic compound layer is 5 nm or less and Rmax (maximum roughness) are 120 nm or less.
The transparent gas barrier film according to the invention of claim 4 is characterized in that the first transparent inorganic compound layer and / or the second transparent inorganic compound layer have gas barrier properties, and silicon oxide, silicon nitride, silicon carbide, aluminum oxide. , Magnesium oxide, indium oxide, and a composite of two or more of these compounds.

(Points of the Invention) The present inventors diligently studied a transparent gas barrier film having a high gas barrier property, and found that the transparent gas barrier film adopting a transparent resin film as a base film causes a low gas barrier property. We focused on the following points. That is, in general, the surface of a polymer such as a resin film has Ra (average roughness) of 2 nm or more, Rmax (maximum height difference) of 80 nm or more, and protrusions having a height of about 500 nm (0.5 μm) are generated in some places. It is in a rough state when viewed microscopically. When a thin gas barrier layer having a film thickness of about 20 nm is formed on such a resin film, pinholes are generated in the gas barrier layer due to protrusions existing on the surface of the transparent resin base film, thereby blocking the gas. It can be considered that the performance is degraded.
In order to solve this, before forming the first transparent inorganic compound, the planarization layer, and / or the second transparent inorganic compound, the surface of the layer is coated or immersed with water or a hydrophilic solvent. Later, by adding a wet heating step of heating, the flatness was remarkably improved, and as a result, it was found that ultra-high gas barrier properties were exhibited, and the present invention was achieved.

According to the first aspect of the present invention, when the first transparent inorganic compound layer, the flattening layer, and the second transparent inorganic compound layer are formed, the wet heating step of the present invention is performed in advance, so that protrusions are formed on the surface to be coated. Even in the presence of other layers, other layers can be formed after being highly planarized in the wet heating process, so that a method for producing a transparent gas barrier film having ultra-high gas barrier properties is provided. .
According to the second aspect of the present invention, since the gas barrier layer can be formed after highly flattened, the transparent resin base film and the transparent resin having a super high gas barrier property. A transparent gas barrier film in which a first transparent inorganic compound layer is provided on one surface of a base film, a transparent gas barrier film in which a flattening layer is further provided on the first transparent inorganic compound layer surface, and the flattened layer surface A transparent gas barrier film comprising a second transparent inorganic compound layer or a transparent resin substrate film and a planarizing layer and a second transparent inorganic compound layer provided on one surface of the transparent resin substrate film. A method for producing a transparent gas barrier film is provided.
According to the third aspect of the present invention, even if a protrusion is present on the transparent resin base film, it is excellent in gas barrier property by flattening the protrusion, and the transparent resin base film and the gas barrier property. Provided is a transparent gas barrier film that has high layer adhesion, is light, does not crack, is bent, and can be used for a polymer substrate having total physical properties that can be substituted for a glass substrate.
According to this invention of Claim 4, the transparent gas barrier film which has higher gas barrier property is provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view showing one embodiment of the transparent gas barrier film of the present invention.
FIG. 2 is a cross-sectional view showing one embodiment of the transparent gas barrier film of the present invention.
FIG. 3 is a cross-sectional view showing a display substrate using the transparent gas barrier film of the present invention.
FIG. 4 is an explanatory view for explaining a wet heating step for producing the transparent gas barrier film of the present invention.

(Invention of Product) As shown in FIG. 1, the transparent gas barrier film 10 of the present invention has a transparent resin base film 11 and at least one surface of the transparent resin base film 11 with a first transparent inorganic compound. The layer 13A, the flattening layer 15, and the second transparent inorganic compound layer 13B are sequentially formed, that is, the transparent resin base film 11 / the first transparent inorganic compound layer 13A / the flattening layer 15 / the second transparent inorganic compound layer 13B. It is a layer structure.
Moreover, it is preferable to set it as the object or the layer structure close | similar to an object so that stress may be canceled. That is, as shown in FIG. 2, the second planarizing layer 15B / the third transparent inorganic compound layer 13C / the transparent resin base film 11 / the first transparent inorganic compound layer 13A / the planarizing layer 15 / the second transparent inorganic compound layer. 13B layer configuration.
Here, as the transparent resin substrate film 11, a transparent resin substrate film having a glass transition temperature Tg of 150 ° C. or more and 300 ° C. or less and a light transmittance of 80% or more is used, followed by a wet heating process described later. By forming the transparent inorganic compound layer 13B, the surface roughness Ra (average roughness) of the second transparent inorganic compound layer 13B can be 5 nm or less, and Rmax (maximum roughness) can be 120 nm or less. As a result, ultra-high gas barrier properties can be expressed.

(Invention of method)
In the manufacturing process of the transparent gas barrier film 10 of the present invention, layers such as the first transparent inorganic compound layer 13A, the flattening layer 15, and / or the second transparent inorganic compound layer 13B are formed. Prior to the forming step, the transparent resin base film 11, the first transparent inorganic compound layer 13 </ b> A, and / or the planarization layer 15 surface, which will be the application surface, are wet-heated in advance.
That is,
(A) preparing a transparent resin base film 11;
(B) a step of wet-heating one surface of the transparent resin substrate film 11;
(C) forming a first transparent inorganic compound layer 13A on the cleaned surface;
(D) wet heating the surface of the first transparent inorganic compound layer 13A;
(E) forming a planarization layer 15 on the cleaning surface;
(F) Wetting and heating the surface of the planarization layer 15;
(G) forming the second transparent inorganic compound layer 13B on the surface of the planarizing layer 15;
However, in the case where one or a plurality of layers are not provided, the wet heating step before the layer is not necessary, and the wet heating step may be performed according to the layer to be configured.

In the wet heating step, as shown in FIG. 4, (a) water or a hydrophilic solvent is applied or immersed, (b) dried if necessary, and (c) heated to 150 ° C. or higher.
However, the drying of (b) may not be performed as a process, but may be performed in parallel with the air drying or the heating of (c). In short, the heating is performed in a state where the influence of water or a hydrophilic solvent remains. That's fine. The wet heating step includes the step of forming the surface of the transparent resin substrate film 11 before forming the first transparent inorganic compound layer 13A, the surface of the first transparent inorganic compound 13A before forming the surface of the planarizing layer 15, and / or the first. It is characterized by performing before forming a layer so that the surface of the planarization layer 15 may be wet-heated before forming the 2 transparent inorganic compound layer 13B.
In the present specification, wet heating means that water or a hydrophilic solvent is applied or immersed, and the water or the hydrophilic solvent adsorbs and / or penetrates the surface, and the influence of water or the hydrophilic solvent remains. In a wet state, heating at 150 ° C. or higher is performed.
When such a transparent inorganic compound layer is in contact with water or a hydrophilic solvent, the gas-shielding thin film such as an inorganic compound is cracked due to the high expansion of the substrate (transparent resin base film), and the gas-shielding property. Therefore, those skilled in the art do not perform contact with water or a hydrophilic solvent and subsequent heating at 120 ° C. or higher. Therefore, in the present invention, the flatness is remarkably improved by contact with water or a hydrophilic solvent, followed by wet heating at a high temperature of 150 ° C. or higher. It was found that sex was expressed.

  Before forming the first transparent inorganic compound layer 13A, the coated surface of the first transparent inorganic compound layer 13A of the transparent resin base film 11 is coated (coated) or immersed with water or a hydrophilic solvent, dried and heated. Thus, the affinity between the first transparent inorganic compound layer 13A and the transparent resin base film 11 is improved, and the adhesion is improved. Moreover, by continuing the heating step, the transparent resin substrate film 11 is dried, and poor film adhesion due to degassing during film formation is prevented.

Water or a hydrophilic solvent is not particularly limited as long as it does not degrade the transparent resin substrate film 11, and depending on the material of the transparent resin substrate film 11, pure water, acidic aqueous solution, alkaline aqueous solution, organic acid compound solution Organic base compound solutions, organic compound solutions such as alcohols, esters, and amides, metal salt aqueous solutions, and the like can be used. In general, the first transparent inorganic compound layer 13A and the planarizing layer 15 are not deteriorated by water or a hydrophilic solvent.
As a method of application or immersion, a known wet method such as dip coating, spin coating, gravure coating, roll coating, or the like can be applied. In order to improve contact and further shorten the contact time, it is preferable to use vibration, fine foaming, ultrasonic waves, or the like in combination.

Further, in the state where the first transparent inorganic compound layer 13A is formed on the transparent resin base film 11, there are innumerable fine protrusions on the surface of the first transparent inorganic compound layer 13A. Therefore, surprisingly, it exists innumerably by applying (coating) or immersing with water or a hydrophilic solvent on the surface of the first transparent inorganic compound layer 13A, drying, and passing a subsequent wet heating step. This time, we found that the number of microprotrusions decreased.
The reason why the fine protrusions are reduced is not clear, but is estimated as follows.
If there are defects such as protrusions, holes, cracks, and recesses on the surface of the first transparent inorganic compound layer 13A, the portions are greatly affected when water or a hydrophilic solvent is applied. Furthermore, in a wet state where water or a hydrophilic solvent is adsorbed and / or infiltrated on the surface, by heating at 150 ° C. or higher, the portion further deteriorates, the protruding portion is scraped and peeled, and the recessed portion is a hole. Becomes larger. Accordingly, the protrusions disappear, but the number of holes increases, so that the gas barrier property is deteriorated and the surface property is not good.
Therefore, by forming the flattening layer 15 on the wet heating surface, the holes in the defective portion are repaired, and the surface is flat without protrusions, so that a high gas barrier property is obtained. It is done.

  One of the purposes of heating in the wet heating step is to advance the destruction of the protrusions of the first transparent inorganic compound layer 13A, so that the heating temperature is about 120 ° C. or higher, preferably 150 ° C. or higher. The heating temperature may be appropriately selected according to the base material and the material of the first transparent inorganic compound layer 13A. A temperature of 150 ° C. or lower is not sufficient for deteriorating abnormal protrusions formed on the surface of the first transparent inorganic compound layer 13A, and a long time is used at temperatures below 120 to 150 ° C. The upper limit temperature is appropriately determined from a temperature of 150 ° C. or higher in view of heat resistance such as the glass transition temperature Tg of the material of the transparent resin substrate film 11 to be used.

When water or a hydrophilic solvent is applied or immersed, the contact time is about 5 seconds or more, preferably 5 minutes or more in order to sufficiently contact the surface. In addition, it is preferable to apply ultrasonic waves during application or immersion because deterioration is promoted and the detached defective portion is removed.
Conventionally, the wet heating process of the surface has been performed, but it is performed under conditions that do not cause deterioration of the gas barrier film, and the subsequent drying process is also performed at a temperature of approximately 120 ° C. or lower because the purpose is dehydration. . Above that temperature, the gas-shielding thin film such as an inorganic compound is cracked due to the high expansion of the substrate (transparent resin base film), and the gas-shielding property is deteriorated.
Accordingly, since those skilled in the art do not perform contact with water or a hydrophilic solvent and subsequent heating at 120 ° C. or higher so as to deteriorate the gas barrier film, the present invention dares to use water. Alternatively, it is a feature that contact with a hydrophilic solvent and subsequent wet heating at a high temperature of 150 ° C. or higher are performed.

Moreover, before forming the 2nd transparent inorganic compound layer 13B, it is for the reason similar to the above also to apply | coat or immerse water or a hydrophilic solvent on the surface of the planarization layer 15, and to heat.
The means for heating is not particularly limited, but means by heat ray radiation or heat conduction is simple and desirable, but means by irradiation with energy such as infrared rays or ultraviolet rays, laser light, electron beam, plasma, etc. may be used.

(Transparent resin base film) As the transparent resin base film 11 used for the transparent gas barrier film 10 of the present invention, a glass transition temperature Tg of 150 ° C. or higher and 300 ° C. or lower and a light transmittance of 80% or higher can be applied. Moreover, the linear expansion coefficient of the transparent resin substrate film 11 is preferably 15 ppm / K or more and 100 ppm / K or less.
The light transmittance of 80% or more is a condition for the transparent resin substrate film 11 to be used as an electronic component or a laminated film for display, and the visibility is deteriorated below this range. .

  The transparent resin base film 11 used in the present invention is characterized in that Tg is 150 ° C. or higher and 300 ° C. or lower. Below 150 ° C, the substrate dimensions are not stable when the gas barrier film is allowed to flow through the process at the above temperature, and the disadvantage that the barrier performance deteriorates due to thermal expansion and contraction, or the problem that the thermal process cannot withstand. Is likely to occur. Above 300 ° C., the film is easily broken like glass and the flexibility is deteriorated. Further, the transparent resin base film 11 having no Tg is not worthy of question because the effect of the linear expansion coefficient on the flexibility is great.

  The material of the transparent resin base film used in the present invention includes acrylate compound or methacrylate compound, cyclic polyolefin compound, polycarbonate compound, polyetherssulfone, polyimide compound compound, PEEK, PEI, polysiloxane compound, ETFE. , PFA and the like. More preferably, the resin composition containing the acrylate compound or methacrylate compound which has a cycloalkyl skeleton shown in Unexamined-Japanese-Patent No. 11-222508, and its derivative (s) can be mentioned.

(First transparent inorganic compound layer) The purpose of providing the first transparent inorganic compound layer 13A is to planarize the transparent gas barrier film 10 in addition to the function of blocking the permeation of water vapor and oxygen. In order to prevent film peeling due to the stress of the laminate of the layer 15 and the second transparent inorganic compound layer 13B, the layer 15 is sandwiched between the transparent resin base film 11 and firmly adhered thereto. It is also a layer for preventing degassing from the substrate.
Further, since the thin film such as the second transparent inorganic compound 13B is formed under high vacuum conditions, degassing from the transparent resin substrate film 11 under high vacuum inhibits film formation and forms a dense film. Therefore, degassing can be prevented and stable film formation can be performed.

  Examples of the first transparent inorganic compound layer 13A include those having gas barrier properties, such as silicon oxide, silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, indium oxide and the like, and two or more kinds of composites selected from them. be able to. Among these, a film made of silicon oxide is preferably used because it exhibits highly transparent gas barrier properties, while silicon nitride exhibits even higher gas barrier properties. Particularly preferably, a composite of silicon oxide and silicon nitride is preferable. When the content of silicon oxide is large, the transparency is increased, and when the content of silicon nitride is large, the gas barrier property is increased.

  The layer of the transparent inorganic compound 13A is formed by applying a method such as a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method or a plasma CVD method. These methods are selected in consideration of the type of the base material and the transparent inorganic compound layer 13A (functionally a flattening layer), the type of film forming material, the ease of film forming, the process efficiency, and the like. .

  The thickness of the transparent inorganic compound 13A layer is desirably 10 to 500 nm. If it is less than 10 nm, the gas barrier property as a display substrate is not sufficient, and if it exceeds 500 nm, its own stress increases and flexibility is impaired. Further, it is not preferable because protrusions are formed due to abnormal grain growth and Rmax tends to increase.

(Planarization layer) The planarization layer 15 is a layer formed on the surface of the first transparent inorganic compound layer 13A to reduce the surface Ra and Rmax. It is a film formed by hydrolysis and reaction with water or a hydrophilic solvent in a coating and drying process.
As measured values, Ra (average roughness) is flattened to a range of 2 nm or less and Rmax (maximum roughness) is 120 nm or less, and the resulting transparent gas barrier film 10 can exhibit high gas barrier properties. The first transparent inorganic compound layer 13A and the flattening layer 15 are functionally flattening functions, and in particular by having both layer configurations, the affinity with the inorganic compound layer and wettability are good. Defects such as holes, recesses, and cracks can be filled, covered, and closed. Moreover, since leveling property is good, it fills and covers a defect, and the surface after drying becomes smooth. The synergistic effect of this affinity and leveling properties provides a super flattening function.
The lower limit of the center line average roughness Ra is not particularly limited, but is practically 0.01 nm or more. For this reason, the transparent gas barrier film 10 obtained can exhibit an ultra-high gas barrier property.
Conventionally, there is a method in which both sides of the transparent resin base film 11 and at least the side on which the first transparent inorganic compound layer 13A is provided are polished to improve the smoothness. According to the present invention, this can be solved.

The planarization layer 15 is formed by a known method such as a dry method (sputtering method, ion plating method, CVD method, etc.) or a wet method (spin coating method, roll coating method, casting method). be able to.
As the material of the planarizing layer 15, a material having a high affinity with a transparent inorganic compound or a material having a high transparency is preferred, but any kind of organic compound or inorganic compound may be used. As organic compounds, resins such as polyester, polyamide, polyimide, polyurethane, polyurea, and polyacrylate are used, and as inorganic compounds, compounds such as silicon carbide, silicon nitride, silicon oxide, aluminum oxide, and indium oxide are used. But that's not the case. Organic and inorganic mixed compounds are also suitable for use and are common as sol-gel coat films.

  As the material for the sol-gel coat film, for example, an aminoalkyl dialkoxysilane, an aminoalkyltrialkoxysilane, and a composite mainly composed of these compounds can be preferably used. A planarization layer can be formed by wet coating using these materials. In that case, the coating composition using these materials and the crosslinkable compound as a raw material is applied to the surface of the first transparent inorganic compound layer 13A and dried, thereby hydrolyzing, condensing, and crosslinking with the crosslinkable compound. The sol-gel reaction proceeds, and the sol-gel coat layer is a reaction product obtained by a chemical reaction mainly including hydrolysis of the above material, and a polysiloxane-based coating film having a crosslinked structure is obtained.

Japanese Patent Application Laid-Open Nos. 7-3206 and 7-18221 describe the use of the above alkoxysilane compounds. However, it is applied on an arbitrary plastic film to give a gas barrier function and gives gas barrier properties, and the transparent flattening layer 15 for improving the flatness of the laminate in the present invention. The purpose is different.
Moreover, even if a flattening agent as described in Japanese Patent Nos. 3438266 and 3438267 is used, only insufficient flatness can be obtained. The present inventors can obtain sufficient flatness only when aminoalkyl dialkoxysilane, aminoalkyltrialkoxysilane or the like is formed on the surface of the first transparent inorganic compound layer 13A, and the flat surface. In addition, it has been found that by providing a barrier layer (second transparent inorganic compound layer 13B), a super barrier property is exhibited.

  (Second transparent inorganic compound layer) The second transparent inorganic compound layer 13B also has a function of blocking the permeation of water vapor, oxygen, etc. in the transparent gas barrier film 10, and is capable of degassing from the planarizing layer 15. It has the effect of preventing and modifying the surface quality of the laminate. For example, when used as a display substrate, it is necessary to further provide a layer such as a transparent electrode on this surface. When the second transparent inorganic compound layer 13B is provided, an electrode layer having high affinity, good adhesion, and excellent conductivity can be formed.

  The second transparent inorganic compound layer 13B is preferably the same as the material used for the first transparent inorganic compound layer 13A. For example, silicon oxide, silicon nitride, silicon carbide, aluminum oxide, magnesium oxide, indium oxide and the like and two or more kinds of composites selected from them can be given. Among these, a film made of silicon oxide is preferably used because it exhibits highly transparent gas barrier properties, while silicon nitride exhibits even higher gas barrier properties. Particularly preferably, a composite of silicon oxide and silicon nitride is preferable. When the content of silicon oxide is large, the transparency is increased, and when the content of silicon nitride is large, the gas barrier property is increased.

  For the formation of the second transparent inorganic compound layer 13B, a method such as a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method or a plasma CVD method is applied. These methods may be appropriately selected in consideration of the type of the base material and the planarization layer, the type of film forming material, the ease of film formation, the process efficiency, and the like.

  The thickness is desirably 10 nm or more and 500 nm or less. If it is less than 10 nm, the gas barrier property as a display substrate is not sufficient, and if it exceeds 500 nm, the flexibility of the layer is impaired. Further, there is a possibility that protrusions are formed due to abnormal grain growth and Rmax is increased.

  (Third transparent inorganic compound layer) As the third transparent inorganic compound layer 13C, the same materials as those used for the first transparent inorganic compound layer 13A and the second transparent inorganic compound layer 13B can be applied.

  (Second Planarizing Layer) As the second transparent planarizing layer 15B, the same material and forming method used for the first transparent planarizing layer 15 can be applied.

(Layer structure) The layer structure of the transparent gas barrier film 10 is at least the transparent resin base film 11 / the first transparent inorganic compound layer 13A / the transparent flattening layer 15 / the flattening layer 15 for flattening for the reasons described above. A laminated structure in which two transparent inorganic compound layers 13B are laminated in this order is defined as a basic layer configuration. A conventional two-layer structure such as Japanese Patent Application Laid-Open No. 07-126419 cannot provide sufficient characteristics even if the lamination is repeated, and is essentially heterogeneous.
Further, a flattening layer and a transparent inorganic compound layer may be repeatedly formed thereon, and if this is repeated, the gas barrier property is further enhanced.
Even if there is a local defect in the underlying film (layer), the film grows discontinuously through the planarization layer 15, so that the defect continuity is lost. Therefore, deterioration of the barrier property can be suppressed. Even if there is a defect, the probability that the defect overlaps at the same location can be extremely low. It is desirable that the flattening layer and the transparent inorganic compound layer are laminated on the transparent inorganic compound layer one to five times in order in order to impart high water vapor barrier properties and oxygen barrier properties.

(Target Layer Structure) It is preferable that the layers formed on both sides of the transparent resin base film 11 have the same or similar layer structure so that the front and back surfaces are symmetrical. In the transparent gas barrier film 10, on the surface of the transparent resin substrate film 11 opposite to the first transparent inorganic compound layer 13A, as shown in FIG. 2, a third transparent inorganic compound layer 13C, a third transparent inorganic film The compound layer 13C / second planarization layer 15B or the third transparent inorganic compound layer 13C / second planarization layer 15B / fourth transparent inorganic compound layer 13D may be provided. By forming a layer such as a transparent inorganic compound layer on the opposite side in this way, the stress generated when the film is formed on only one side is canceled or relaxed, and distortion and warpage in post-processing steps including heating ( Therefore, the right-angle accuracy, the dimensional accuracy, and the dimensional accuracy at the partial location can be improved. Further, for example, the problem of alignment required at the time of patterning is eliminated in a subsequent process such as electrode formation. Furthermore, there is no bias in flexibility and there are no problems in use.
Furthermore, at the same time, degassing generated from the opposite surface of the transparent gas barrier film can be prevented, so that a high-quality transparent gas barrier film having a dense and uniform thickness can be stably formed. When forming the transparent inorganic compound layer on the opposite side, it is more preferable to take into consideration the thickness of the layer to be formed, the inorganic material to be used, the layer configuration, etc., for stress cancellation or relaxation.

The material used for the transparent inorganic compound layer formed on the opposite side is not limited to silicon oxide, silicon nitride, and composites thereof, and any transparent inorganic compound such as aluminum oxide or indium oxide may be used. Silicon, silicon nitride and composites thereof are desirable.
As the material used for the transparent flattening layer formed on the opposite side, the same material as the transparent flattening layer 15 described above can be applied.

  (Display Substrate) As shown in FIG. 3, the display substrate is formed by forming a transparent conductive layer 21 on the uppermost layer of the transparent gas barrier film 10 of the present invention. The display substrate has transparency, heat resistance, solvent resistance, gas A display substrate having an excellent barrier property and interlayer adhesion can be provided. The material used for the transparent conductive layer 21 is not particularly limited as long as it is transparent and conductive, such as tin oxide, indium oxide, ITO, ATO, or silver.

  As the (display) display, any display substrate of the present invention may be used. A plasma display panel (PDP), a liquid crystal display (LCD), an organic or inorganic electroluminescence display (ELD), a field emission display (FED). It can be suitably applied to a thin type with a small depth.

  (LCD) A liquid crystal display is one in which transparent electrodes are placed on the inside of two glass substrates, liquid crystal is sandwiched between alignment layers and the surroundings are sealed, and the surroundings are colored. With a color filter for. The gas barrier film 10 of the present invention can be applied to the outside of the glass substrate of such a liquid crystal display, or the gas barrier film 10 of the present invention can be used in place of the glass substrate. In particular, if both of the two glass substrates are replaced with the gas barrier film 10 of the present invention, the entire display can be made flexible.

(Organic ELD) An organic EL display also has a transparent electrode on the inside of two glass substrates, and, for example, (a) injection function, (b) transport function, and (c) light emission between them. An organic EL element layer composed of a composite layer, etc., in which layers having various functions are stacked is sandwiched and the periphery is sealed, and may be accompanied by a color filter or other means for colorization . For example, when forming an EL display, for example, the display substrate of the present invention (including a patterned transparent conductive layer) / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode / sealing. Examples of the layer configuration include layers, but the layer configuration is not limited to this.
As in the liquid crystal display, the gas barrier film 10 of the present invention can be applied to the outside of the glass substrate, or the gas barrier film 10 of the present invention can be used instead of the glass substrate, If the two glass substrates are replaced with the gas barrier film 10 of the present invention, the entire display can be made flexible. In particular, the organic EL element is chemically unstable because it uses fluorescent light emission, and is extremely vulnerable to moisture, and therefore, it is desired to have a high level of water vapor barrier property after it has become a product.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this.

A cyclic polyolefin resin (manufactured by ZEON Corporation) having a thickness of 200 μm, Tg of 176 ° C. and a light transmittance of 92% is used as a transparent resin base film, and the coated surface is immersed in pure water to which ultrasonic waves are applied for 5 minutes. A wet heating step was performed by heating at 160 ° C. for 60 minutes.
A 50 nm silicon oxynitride film is formed on the surface by sputtering to form a first inorganic compound layer. The surface is further immersed in pure water to which ultrasonic waves are applied for 5 minutes, and then heated at 160 ° C. for 60 minutes to be wet. Heating was performed.
Thereafter, a sol-gel coating agent containing aminoalkyltrialkoxysilane as a main component is applied by a spin coating method, dried on a hot plate at 120 ° C. for 2 minutes, and then dried at 160 ° C. for 1 hour to obtain a film thickness of about 1 μm. A flattened layer was obtained.
Thereafter, it was further immersed in pure water to which ultrasonic waves were applied for 5 minutes, and then heated at 160 ° C. for 60 minutes to perform wet heating.
Further, a 50 nm silicon oxynitride film was formed on the upper surface by sputtering to form a second inorganic compound layer, and the gas barrier film of Example 1 was obtained.

  The procedure was the same as Example 1 except that the wet heating step of the transparent resin substrate film was not performed.

  The same procedure as in Example 1 was performed, except that the wet heating step of the first inorganic compound layer (silicon oxynitride layer) surface was not performed.

  The same procedure as in Example 1 was performed except that the wet heating step of the planarizing layer surface was not performed.

    A cyclic polyolefin resin (manufactured by Zeon Corporation) having a thickness of 200 μm, Tg of 176 ° C. and a light transmittance of 92% was used as a transparent resin base film, and a 50 nm silicon oxynitride film was formed on the surface by sputtering. After that, it was further immersed in pure water ultrasonic wave for 5 minutes and then heated at 160 ° C. to perform wet heating. Thereafter, a sol-gel coating agent containing aminoalkyltrialkoxysilane as a main component was applied by a spin coating method, dried at 120 ° C. for 2 minutes by a hot plate, and then dried at 160 ° C. for 1 hour by a dryer. A planarization layer was obtained. Further, a 50 nm silicon oxynitride film was formed on the upper surface by sputtering to obtain a gas barrier film of Example 5.

  A cyclic polyolefin resin (manufactured by ZEON Corporation) having a thickness of 200 μm, Tg of 176 ° C. and a light transmittance of 92% was used as a transparent resin base film, and a 50 nm silicon oxynitride film was formed on the surface by sputtering. Thereafter, a sol-gel coating agent containing aminoalkyltrialkoxysilane as a main component was applied by a spin coating method, dried at 120 ° C. for 2 minutes by a hot plate, and then dried at 160 ° C. for 1 hour by a dryer. A planarization layer was obtained. Then, it was immersed in pure water ultrasonic waves for 5 minutes, and then heated at 160 ° C. to perform wet heating. Further, a 50 nm silicon oxynitride film was formed on the upper surface by sputtering to obtain a gas barrier film of Example 6.

  Example 1 was performed except that a polyacrylate resin (Mitsubishi Chemical Corporation) having a thickness of 200 μm and a Tg of 300 ° C. was used as a base material.

(Comparative Example 1)
A cyclic polyolefin resin (manufactured by ZEON Corporation) having a thickness of 200 μm, Tg of 176 ° C. and a light transmittance of 92% was used as a base material, and a 50 nm silicon oxynitride film was formed on the upper surface by sputtering. Thereafter, a sol-gel coating agent mainly composed of aminoalkyltrialkoxysilane was applied by a spin coating method, dried at 120 ° C. for 2 minutes by a hot plate, and then dried at 160 ° C. for 1 hour by a dryer, and the film thickness was about 1 μm. A planarization layer was obtained. Further, a 50 nm silicon oxynitride film was formed on the upper surface by sputtering to obtain a gas barrier film.

(Comparative Example 2)
A cyclic polyolefin resin (manufactured by ZEON Corporation) having a thickness of 200 μm, Tg of 176 ° C. and a light transmittance of 92% was used as a base material, immersed in pure water for 5 minutes, and then wet-heated at 160 ° C. A 50 nm silicon oxynitride film was formed on the upper surface by sputtering. Thereafter, a sol-gel coating agent containing aminoalkyltrialkoxysilane as a main component was applied by a spin coating method, dried at 120 ° C. for 2 minutes by a hot plate, and then dried at 160 ° C. for 1 hour by a dryer. A planarization layer was obtained. Further, a 50 nm silicon oxynitride film was formed on the upper surface by sputtering to obtain a gas barrier film.

(Comparative Example 3)
The same procedure as in Example 1 was performed except that the temperature of each heating step was 120 ° C.

(Comparative Example 4)
Example 1 was repeated except that a PET resin (Toyobo Co., Ltd.) having a thickness of 188 μm, a Tg of 78 ° C. and a light transmittance of 89% was used.

(Measurement) The surface roughness Ra was measured using an atomic force microscope (manufactured by Seiko Co., Ltd.) and the average roughness (Ra) maximum height difference (Rmax) was measured in a scanning range of 20 μm.
The water vapor transmission rate was measured using a water vapor transmission rate measuring device Permatran 3/31 (trade name, manufactured by MOCON) under the conditions of 40 ° C. and 100% Rh.
The oxygen permeability was measured using an oxygen permeability measuring device oxytolan 2/20 (trade name, manufactured by MOCON) under conditions of 23 ° C., 90% Rh, individual zero for performing background removal measurement, and measurement.
The measurement results are shown in “Table 1”.

(Evaluation results) In Examples 1 to 7, Ra was 2 nm or less, Rmax was 120 nm or less, and the oxygen permeability and water vapor permeability were good below the measurement limit of 0.05 or less.
In Comparative Example 1, Rmax was as large as 256 nm and the oxygen permeability was good, but the water vapor permeability was slightly bad.
In Comparative Example 2, Ra was a little as large as 2.22 nm, but the oxygen permeability and water vapor permeability were good below the measurement limit of 0.05 or less. Application to a plastic substrate and heating have little effect on the flatness because the effect on the deterioration of the protrusions is small.
In Comparative Examples 3 and 4, Rmax was as large as 125 nm and 268 nm, respectively, and the oxygen permeability was good, but the water vapor permeability was slightly bad at 0.06 and 0.10, respectively.

It is sectional drawing which shows one Example of the transparent gas barrier film of this invention. It is sectional drawing which shows one Example of the transparent gas barrier film of this invention. It is sectional drawing which shows one Example of the display substrate of this invention. It is explanatory drawing explaining the wet heating process for manufacturing the transparent gas barrier film of this invention.

Explanation of symbols

10: Transparent gas barrier film 11: Transparent resin base film 13A: First inorganic compound layer 13B: Second inorganic compound layer 13C: Third inorganic compound layer 15A: Planarizing layer 15B: Second planarizing layer 20: High Molecular substrate 21: Transparent electrode

Claims (2)

In the method for producing a transparent gas barrier film having a glass transition temperature Tg of 150 ° C. or more and 300 ° C. or less and one or more layers on one surface of the transparent resin substrate film, When forming at least one of a plurality of layers, a transparent gas barrier film characterized by performing a wet heating step of heating to 150 ° C. or higher after previously applying or immersing water or a hydrophilic solvent. Production method. A transparent gas barrier film having a glass transition temperature Tg of 150 ° C. or higher and 300 ° C. or lower and a first transparent inorganic compound layer provided on one surface of the transparent resin substrate film, the first transparent inorganic film A transparent gas barrier film in which a flattening layer is further provided on the compound layer surface, a transparent gas barrier film in which a second transparent inorganic compound layer is further provided on the flattened layer surface, or a glass transition temperature Tg of 150 ° C. or higher and 300 ° C. In the following method for producing a transparent gas barrier film comprising a transparent resin base film and a planarizing layer and a second transparent inorganic compound layer provided on one surface of the transparent resin base film, the first transparent inorganic compound layer When the flattening layer and / or the second transparent inorganic compound layer is formed, a wet heating step is previously provided, and the wet heating step applies or immerses water or a hydrophilic solvent. Later, the production method of the transparent gas barrier film, characterized in that heating above 0.99 ° C..

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