JP2006255918A - Optical film laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly heat-resistant optical film laminate suppressed in the occurrence of curling and excellent in gas barrier properties using a film low in the coefficient of thermal expansion. <P>SOLUTION: In the optical film laminate constituted by forming an inorganic compound-containing layer at least on one side of a film containing a polymer, at least one in-plane direction of the film, which becomes -15 to 50 ppm/°C in the coefficient of thermal expansion at 30-100°C is present in the film and the light transmittance of light with all of wavelengths of 450-700 nm of the laminate is 80-100%. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical film, and more particularly to an optical film laminate that can be suitably used in place of glass as a substrate for a display material having excellent gas barrier properties.

  Conventionally, glass has been used as a base material for organic EL displays and liquid crystal displays, but in recent years it is lightweight, can be reduced in thickness, can be easily increased in area, not cracked, and has excellent workability. A method of substituting with a film having the property of being proposed is proposed. Similarly, the use of film as a base material for electronic paper, field emission displays, and solar cells has been proposed with the aim of reducing thickness and weight.

  Thus, when using a film as a substitute for the glass member used for a flexible display, a solar cell, etc., high water vapor barrier property is an essential characteristic as well as high transparency. Organic polymer compounds have lower gas barrier properties than inorganic compounds, so films made of organic polymers have lower gas barrier properties than glass made of inorganic compounds, and it is difficult to maintain the performance of display elements for a long period of time. . For example, it is known that the light emitting layer of an organic EL element is deteriorated by moisture or oxygen. When a film is used for an organic EL display, it is necessary to provide a gas barrier layer on the film. This gas barrier layer can be formed at a low temperature, but when it is formed at a low temperature, a gas barrier property sufficient for display applications cannot be obtained. Therefore, processing at a high temperature is required to form a layer having excellent gas barrier properties. Similarly, although the transparent conductive layer required in the flexible display can be formed at a low temperature, high-temperature processing is required to obtain a low-resistance layer. For these reasons, the film needs to have heat resistance that can withstand high-temperature processes during processing.

  Patent Document 1 describes a film with a gas barrier layer in which a metal oxide is laminated on a resin made of a mixture of polyester and epoxy. However, although this film has a sufficient barrier property when used for packaging foods and the like, it is not of sufficient quality when used as a display.

  Patent Document 2 describes a film laminate with a gas barrier layer. In this embodiment, a polyethylene terephthalate (PET) film is used as the base material. However, polyethylene terephthalate (PET) has a glass transition temperature of about 80 ° C. and is inferior in heat resistance. Also, when forming a gas barrier layer on a film with poor heat resistance, it is necessary to lower the processing temperature, but when forming an inorganic compound with excellent barrier properties at low temperatures, it is difficult to form a dense film, and gas barrier properties Can not increase. This document also describes a film other than polyethylene terephthalate as a film, and also describes that it can be applied to a resin having high heat resistance. However, even with these resins having a high glass transition temperature, the thermal expansion coefficient of 30 ° C. to 100 ° C. is usually a large value exceeding 50 ppm / ° C. Therefore, when an inorganic material having a small thermal expansion coefficient is laminated, In addition, the laminate is curled.

When the gas barrier layer is formed on a rough surface, defects may occur in the formed layer. Patent Document 3 describes a laminate in which a flattening layer is provided on a film and a gas barrier layer is formed thereon for the purpose of preventing defects in the gas barrier layer. By providing the planarization layer, a dense gas barrier layer is formed even for a film having poor surface smoothness. However, while acrylic and polycarbonate are used as a film in the example of the laminate, glass is used instead of a film as an example of the laminate for an organic EL display. For this reason, there exists a problem which cannot achieve weight reduction and flexibility of an organic EL display. The reason why glass is used for the base material of the laminate for organic EL display is that acrylic and polycarbonate are not sufficient in terms of heat resistance, thermal expansion, surface smoothness and the like.
JP-A-8-164595 JP 2004-114645 A JP 2004-299230 A

  The present invention has been achieved as a result of studying the above-described problems in the prior art as problems. That is, an object of the present invention is to provide an optical film laminate having a high gas barrier property and a high heat resistance, which suppresses the occurrence of curling due to the difference in thermal expansion coefficient when a film and a layer containing an inorganic compound are laminated. Is to provide.

  The present invention for achieving the above object is a laminate in which a layer containing an inorganic compound is formed on at least one side of a film containing a polymer, and the film has a coefficient of thermal expansion of 30 to 100 ° C. − A laminate having at least one in-plane direction of 15 ppm / ° C. to 50 ppm / ° C. and having a light transmittance of light of all wavelengths from 450 nm to 700 nm of the laminate of 80% to 100%. It is characterized by being.

  According to the present invention, as described below, since the layer containing an inorganic compound is formed on a film having a low thermal expansion coefficient, it can be suitably used for applications requiring a gas barrier property such as a substrate for display materials. There can be obtained a highly heat-resistant optical film laminate that has little curling and excellent gas barrier properties.

  Hereinafter, examples of embodiments of the present invention will be described.

  In general, an inorganic compound is often used for the gas barrier layer or the transparent conductive layer, but the thermal expansion coefficient of the inorganic compound is smaller than that of a general polymer film. For example, in the case of silicon oxide, it is 3 ppm / ° C. to 10 ppm / ° C., which is 1/10 of a general polymer film. Therefore, when an inorganic compound layer is formed on a polymer film, a film is formed in a state of being expanded by heat at the time of layer formation, and when this is cooled to room temperature, the polymer film contracts more than the inorganic compound. Curling may occur on the body. When the curl becomes intense, the layer or the substrate may be broken, which is not preferable. The film containing a polymer used for the laminate of the present invention has at least one in-plane direction in which the coefficient of thermal expansion at 30 to 100 ° C. is −15 ppm / ° C. or more and 50 ppm / ° C. or less. preferable. By setting the thermal expansion coefficient within this range, the dimensional change of the film can be suppressed during high-temperature processing when forming the gas barrier layer and the like, and curling can be prevented from occurring in the laminate. The value of this thermal expansion coefficient is more preferably −10 ppm / ° C. or more and 30 ppm / ° C. or less, and further preferably −10 ppm / ° C. or more and 15 ppm / ° C. or less. By setting it as this range, the difference in thermal expansion coefficient between the layer containing an inorganic compound such as a gas barrier layer formed on the film and the film can be reduced, and a laminate without curling can be obtained, which is preferable. Particularly preferred is the case of from −10 ppm / ° C. to 15 ppm / ° C. and from −10 ppm / ° C. to 20 ppm / ° C. at 100 to 200 ° C. Controlling the coefficient of thermal expansion at 100 ° C. to 200 ° C. is preferable because high-temperature processing is possible, and a dense gas barrier film without curling can be obtained. The range of the above preferable thermal expansion coefficient is applied to at least one direction in the film plane (plane direction) (it may be a value within the range), but is preferably orthogonal in the plane direction of the film. It applies to both of the two directions (the above range is satisfied in any direction orthogonal). More preferably, one of the “at least one direction” and the “two orthogonal directions” is the same as the film forming direction of the film. Moreover, it is particularly preferable that the value of the thermal expansion coefficient satisfies the above preferable range in all directions in the film plane.

  The coefficient of thermal expansion can greatly change the value in that direction and other directions by stretching the film anisotropically. Therefore, it is possible to set a small value only in a specific direction, but there is a problem that the thermal expansion coefficient in a direction orthogonal to this direction becomes large. Regardless of anisotropic stretching, if the thermal expansion coefficient is made small, the thermal expansion coefficient in two or all directions can be kept small, and the dimensional change that occurs during high-temperature processing can be suppressed.

  In the laminate of the present invention, a layer containing an inorganic compound is formed on at least one side of the film. The layer containing the inorganic compound may be formed directly on the film or may be provided via some other layer.

  By forming a layer containing an inorganic compound, the laminate of the present invention can impart functions such as antifouling property, anti-oxidation, scratch resistance and gas barrier properties to the laminate. In particular, when the gas barrier property is enhanced, the laminate is preferable in that it can be suitably used as an alternative to glass used for display materials.

  There are no particular limitations on the inorganic compound, and silicon oxides and nitrides such as silicon nitride, silicon oxynitride, and silicon oxide, or aluminum oxides and nitrides, magnesium oxides, zinc oxides, and zirconium oxides Various inorganic compounds such as products are preferably used.

There is no particular limitation on the formation of the layer containing the inorganic compound, and plasma CVD method, catalytic CVD method, thermal CVD method, sputtering method, ion plating method, vacuum deposition method, reactive deposition method, ion beam assisted deposition method, etc. Can be used.
The layer containing these inorganic compounds is also preferable in the case of a multilayer structure. The thickness of the layer at this time is preferably 5 nm or more and 500 nm or less when the layer is a single layer, and when the layer is a multilayer, each single layer portion is 5 nm or more, and each single layer is a single layer. It is preferable that the total of the layer portions (the total thickness of the layer including the inorganic compound in the multilayer) is 10 nm or more and 500 nm or less. When the monolayer portion is less than 5 nm, the layer containing the inorganic compound may not be able to cover the entire surface of the film, and the gas barrier property may be inferior. When the total thickness of a single layer or multiple layers exceeds 500 nm, the transparency may decrease, and cracks and curls tend to occur.
Note that in the case where the layer containing an inorganic compound is formed as a single layer, the thickness is preferably 20 nm to 300 nm, more preferably 30 nm to 100 nm.
In the case where the layer containing an inorganic compound is composed of multiple layers, preferably each single layer part is 10 nm or more, and the total of each single layer part is 20 nm or more and 350 nm or less, more preferably each single layer part is 15 nm or more. And the total of each single-layer portion is 30 nm or more and 200 nm or less.

In addition to the above-described layer containing an inorganic compound, a layer containing a polymer compound may be formed. The place to be formed may be on a film or on a flattening layer described later. Alternatively, a multilayer structure in which at least one layer including an inorganic compound and a layer including a polymer compound are stacked may be used. Hereinafter, the layer containing the polymer compound in the multilayer structure is referred to as an intermediate layer.
When the gas barrier properties of the layer containing the inorganic compound and the intermediate layer are compared, the layer containing the inorganic compound is generally superior in gas barrier properties. However, a layer containing an inorganic compound has a problem that defects such as pinholes are likely to occur. If there is a defect site, gas easily permeates through the defect site, and thus there is a problem that the high gas barrier property inherent in the inorganic compound cannot be exhibited. By adopting a multi-layer structure in which an intermediate layer is laminated on a layer containing an inorganic compound, the defective portion generated in the layer containing the inorganic compound is smoothed by filling the polymer layer in the intermediate layer to smooth the gas. The effect which suppresses doing is produced. In addition, when a layer containing an inorganic compound is further formed on a layer having a defect site, the newly formed layer is likely to have a defect. The effect which makes it difficult to produce a defect arises in the layer containing the inorganic compound formed on top. By these effects, there is an advantage that the barrier property of the layer containing the inorganic compound is not impaired by providing the intermediate layer.

  Examples of the polymer compound forming the intermediate layer include polysilazane or inorganic polymer compounds such as metal oxides by a sol-gel method, aromatic polyamide, polyamic acid, polyimide resin, polyamideimide resin, polyethersulfone resin, polyethylene resin, Melamine resin, polyurethane resin, polyester resin, polyurea resin, polycarbonate resin, polyacrylic acid resin, polyacrylic acid ester resin, polymethacrylic acid resin, polymethacrylic acid ester resin, modified acrylic resin, maleimide resin, polystyrene resin, polyacrylonitrile resin Organic polymer compounds such as epoxy resins can be used.

  These polymer compound layers are formed by dry forming methods such as sputtering, vacuum deposition, ion plating, chemical vapor deposition, roll coating, gravure coating, gravure reverse coating, slit coating, knife coating, dip coating, and spray coating. It can be formed by a method such as die coating or spin coating.

Moreover, when the surface smoothness of a film is inferior in the laminated body of this invention, it is also preferable to provide a planarization layer between a film and the layer containing an inorganic compound. Here, the flattening layer is a layer having a function of giving a surface superior in surface smoothness to that of the film itself. When a film containing a polymer has pinholes or protrusions, a layer containing an inorganic compound formed thereon is likely to be defective, and the gas barrier performance may be inferior. If the surface smoothness of the film is improved by forming the planarization layer, defects in the layer containing an inorganic compound formed on the planarization layer can be reduced.
As a planarizing layer, polysilazane or inorganic polymer compounds such as metal oxides by sol-gel method, aromatic polyamide, polyamic acid, polyimide resin, polyamideimide resin, polyethersulfone resin, polyethylene resin, melamine resin, polyurethane resin Polyester resin, polyurea resin, polycarbonate resin, polyacrylic acid resin, polyacrylic acid ester resin, polymethacrylic acid resin, polymethacrylic acid ester resin, modified acrylic resin, maleimide resin, polystyrene resin, polyacrylonitrile resin, epoxy resin, etc. Organic polymer compounds can be used. It is also preferable to use the same polymer as the film or the same type and different composition. By using the same polymer as the film or a polymer of the same type and different composition for the flattening layer, peeling between the flattening layer and the film is less likely to cause curling, and the film is flattened. Since the refractive indexes of the layers are equal or close to each other, reflection of light at the lamination interface is less likely to be a problem, which is preferable. Moreover, it is also preferable to laminate | stack a flattening layer as a thin film what has a refractive index lower than a film. By laminating as a low refractive index layer, an effect as an antireflection layer can be produced.

The water vapor permeability of the laminate of the present invention is preferably 1.0 × 10 ⁻¹ g / m ² / day or less, more preferably 5.0 × 10 ⁻² g / m ² / day or less, Particularly preferably, it is 1.0 × 10 ⁻² g / m ² / day or less. By setting the water vapor transmission rate to 1.0 × 10 ⁻¹ g / m ² / day or less, it becomes possible to use it in a field requiring a water vapor barrier property more than a conventional packaging application for foods. For example, it becomes possible to use the laminated body of this invention for the support base material for liquid crystal displays or an organic EL display.
Moreover, it is preferable that the laminated body of this invention is 80% or more and 100% or less of the light transmittance of the light of all the wavelengths of 450 nm-700 nm. When there is a wavelength with a light transmittance of less than 80% even in a part of the wavelength range from 450 nm to 700 nm, the transmittance is inferior, so that the display performance of the display is improved when using a laminate as various optical members for display materials and the like. May be inferior. Since transparency improves, the light transmittance of all wavelengths of 450 to 700 nm is more preferably 85% or more and 100% or less.

  As the polymer used in the film of the present invention, aromatic polyamide resin, polyimide resin, polyamideimide resin, polyether sulfone resin, polyether ether ketone resin, polyphenylene sulfide resin, polynorbornene resin, cyclic polyolefin resin, polyarylate resin, A polycarbonate resin, a methacryl resin, an acrylic resin, an acrylate resin, a methacrylate resin, an epoxy resin, and the like can be given, but the invention is not limited to these.

  Moreover, it is preferable that the film used for the laminated body of this invention has a glass transition temperature of 120 degreeC or more, or does not show a glass transition temperature. When the glass transition temperature is less than 120 ° C., the film may be deformed without maintaining its shape during use at high temperature or during processing. It is preferable to use a polymer having a glass transition temperature of 120 ° C. or higher or a glass transition temperature as a film because high temperature processing such as formation of a gas barrier layer or a transparent conductive layer is possible. The glass transition temperature is preferably 150 ° C. or higher, more preferably 200 ° C. or higher, from the viewpoint of forming a transparent conductive film or TFT (thin film transistor). As the TFT, amorphous silicon or polysilicon is used. Although an amorphous silicon TFT can be formed at a low temperature, the performance as a transistor is inferior to that of a polysilicon TFT due to the slow movement speed of electrons. However, in the case of a polysilicon TFT that is excellent as a transistor, although the electron transfer speed is high, there is a problem that a high temperature is required for TFT formation. Research on the formation of polysilicon TFTs at low temperatures is underway, and there are reports of polysilicon TFTs formed at 250 ° C. For this reason, the glass transition temperature is more preferably 250 ° C. or higher, and the electron transfer rate is more excellent as it is formed at a higher temperature.

  The film used for the laminate of the present invention preferably has a thickness of 10 to 300 μm. When the thickness is less than 10 μm, there is no waist strength and the rigidity is inferior, and therefore the handleability during processing tends to be inferior. When the thickness exceeds 300 μm, it may be difficult to wind the film, and when a film is formed by a solution casting method, it takes a long time to remove the solvent, and the productivity tends to decrease. In addition, the transparency of the film may be lowered. From the above viewpoint, the thickness of the film is more preferably 15 to 150 μm, and particularly preferably 30 to 70 μm.

  When the surface roughness of one surface of the film used in the laminate of the present invention is Ra1 and the surface roughness of the other surface is Ra2, Ra1 and Ra2 satisfy the following formulas (1) to (3): It is preferable to use the film which is doing.

Ra1 <Ra2 (1)
0 nm <Ra1 ≦ 2 nm (2)
0 nm <Ra2 ≦ 3 nm (3)
If the film has pinholes or protrusions, the layer containing the inorganic compound formed thereon is likely to be defective, and various physical properties of the layer containing the inorganic compound, particularly gas barrier performance, may be inferior. Therefore, by setting the surface roughness of the film within the above range, the film can have few defects such as pinholes and protrusions. Therefore, the inorganic compound formed on the film can be formed without providing the above-described planarization layer. Defects are hardly generated in the layer to be included, and a laminate having excellent gas barrier performance can be obtained. Of course, a planarizing layer may be provided even when the above Ra value is satisfied.

  Moreover, when the surface roughness is in the above range, it is preferable because the display quality can be improved when used as a laminate for a display material in order to suppress external haze of the film.

For surface roughness, Ra1 <Ra2
0 nm <Ra1 ≦ 1.0 nm
0 nm <Ra2 ≦ 2.0 nm
Is more preferable,
Ra1 <Ra2
0 nm <Ra1 ≦ 0.8 nm
0 nm <Ra2 ≦ 1.5 nm
It is further preferable to satisfy all of the above. By satisfying these relationships, the layer containing the formed inorganic compound is hardly peeled off or the gas barrier property is reduced, and further, the layer containing the inorganic compound on both sides can be formed.
The yellowness (YI) of the film used for the laminate of the present invention is preferably 0 or more and 4.5 or less. When the yellowness (YI) of the film is greater than 4.5, if a laminate composed of the film is used as a laminate for a display material instead of a glass substrate, the display is colored yellow and the quality deteriorates. There is. By setting the yellowness value to 0 or more and 4.5 or less, when used as a laminate for display material, coloring of the display can be prevented and a high-quality image can be provided. Here, the yellowness is a value obtained from tristimulus values (X, Y, Z) transmitted through the test piece. In order to reduce the yellowness of the film, it is important to have a molecular structure that does not absorb light on the short wavelength side in the visible light region. Further, the yellowness can be lowered by heating temperature and heating time during film formation, solvent selection of a polymer solution, film formation under an inert gas atmosphere such as argon and nitrogen, and the like. More preferably, the yellowness (YI) is 0 or more and 3.0 or less, more preferably 0 or more and 2.5 or less, and particularly preferably 0 or more and 2.0 or less.
The molecular structure that lowers the yellowness preferably has no aromatic moiety. Specifically, a film excellent in colorlessness can be obtained by using a polynorbornene resin, a cyclic polyolefin resin, a methacrylic resin, an acrylic resin, an acrylate resin, a methacrylate resin, etc. Can be lowered. However, in comparison with these compounds, polymers having an aromatic compound in the main chain generally become a film having excellent thermal expansion coefficient, heat resistance, mechanical properties and the like. Therefore, the laminate of the present invention is more preferably a polymer having an aromatic compound in the main chain and having a conjugated structure that prevents the conjugated structure from spreading over the entire molecule to reduce the yellowness. In order to suppress the spread of the electron cloud and not to expand the conjugated structure, a structure that can cut the electron cloud in three dimensions or a structure that suppresses the spread of the electron cloud by having an electron-withdrawing substituent. It is preferable. In addition, as the solvent to be used, use a solvent with a boiling point suitable for the polymer with low heat resistance according to the type of polymer so that a large load is not applied to the polymer when removing the solvent. It is important to select a suitable solvent. For example, when N-methyl-2-pyrrolidone having a boiling point of 200 ° C. is used for an acrylic resin, the solvent cannot be removed unless heated for a long time at a temperature higher than the glass transition temperature of the polymer. The polymer may be colored and the yellowness may increase. Since the heating temperature varies depending on the heat resistance of various polymers, the heating temperature is determined by examining the conditions. Also, when film formation is performed under conditions where oxygen is turned off, the oxidation reaction of the polymer can be suppressed. Therefore, in the case of a polymer that can cause an oxidation reaction, film formation under an inert gas atmosphere is also preferable. . A polymer having an amino group at the end of the main chain of the polymer such as aromatic polyamide or polyimide may be colored by oxidation and increase in yellowness. In this case, it is preferable to form a film under the above-mentioned inert gas atmosphere, but it is also possible to react an amino group with an acid chloride, acid anhydride, carboxylic acid, chloroformate, etc. Is preferable in order to suppress or increase the yellowness and suppress an increase in yellowness due to coloring of the amino group even in an oxygen atmosphere.

  In the laminate of the present invention, the height of the floating portion at the end when heated at 120 ° C. for 3 hours is preferably 0.5 cm or less. When an inorganic compound is laminated on a film as a gas barrier film, the organic polymer and the inorganic compound have different coefficients of thermal expansion, so the film may curl due to heat during processing. When the curl becomes severe, the film or the substrate may be broken. More preferably, the case where no curling occurs even after heating at 200 ° C. for 3 hours (when the above-described height of lifting at the end portion is not recognized) is preferable because the film can be processed at a high temperature. In order to prevent curling even by high temperature processing, the film preferably has a low coefficient of thermal expansion.

The laminate of the present invention preferably has a floating height of 0.5 cm or less at the end of the laminate even after being stored for 7 days (7 × 24 hours) under conditions of a temperature of 60 ° C. and a humidity of 90% RH. . A film containing a polymer may swell by sucking water. For this reason, it may expand | swell by sucking the water | moisture content in the air in use, and a curling may be produced in a laminated body (the above-mentioned edge part may be lifted). When the curl becomes severe, the film or the substrate may be broken. In order to prevent curling in a high humidity environment, it is preferable to keep the humidity expansion coefficient of the film low.
Moreover, it is preferable that the laminate of the present invention does not cause curling under high humidity, and at the same time, does not cause peeling between the layers of the laminate. In a film containing a polymer, the adhesive strength between the layers of the laminate may be reduced by sucking water, and peeling may occur. If such defects do not occur after storage for 7 days (7 × 24 hours) under conditions of a temperature of 60 ° C. and a humidity of 90% RH, the laminate can be used under high humidity, which is preferable.

  The film used in the laminate of the present invention preferably contains an aromatic polyamide. By including the aromatic polyamide, the Young's modulus, transparency, and heat resistance of the film can be improved, and the thermal expansion coefficient can be lowered.

  Further, the structure of the aromatic polyamide includes structural units represented by the chemical formulas (I) and (II), and when the molar fraction of each structural unit is 1 and m, 50 ≦ l ≦ 100, 0 ≦ m It is preferable that ≦ 50.

R ₁ : —CF ₃ , —CCl ₃ , —CBr ₃ , —F, —Cl, —Br, —OH, —OCH ₃ (however, structural units having these groups may be mixed in the molecule) .)
R _2: any aromatic radical R _3: hydrogen, halogen or a hydrocarbon group having 1 to 3 carbon atoms

R ₄ : Arbitrary aromatic group R ₅ : Arbitrary aromatic group When the molar fractions of the structural units represented by the chemical formulas (I) and (II) are 1 and m, respectively, it is preferable that l ≧ 50. It is a mode. More preferably, l ≧ 80, and most preferably l = 100. When l <50, the transmittance of the aromatic polyamide may be inferior, and the YI value and thermal expansion coefficient may be large. Aromatic polyamides are believed to be colored by intramolecular and intermolecular charge transfer complexes, but both chemical formulas (I) inhibit the formation of intramolecular and intermolecular charge transfer complexes, resulting in aromatic polyamides. It is thought to improve the light transmittance of the film. Furthermore, chemical formula (I) has a rigid molecular structure composed of para bonds, and the thermal expansion coefficient can be lowered due to this structure.

Wherein the chemical formula (I), _{R 1 is, -CF 3, -CCl 3, -CBr} 3, -F, with -Cl, -Br, -OH, these groups in -OCH ₃ (however, in the molecule structural units may be mixed.) While such is preferably used, from the viewpoint of light _{transmittance, -CF 3, -CCl 3, -CBr} 3, -F, -Cl is particularly preferred, and most preferably is -CF _3.
Further, when the molar fractions of the structural units represented by the chemical formula (I) and the chemical formula (II) are l and m, the thermal expansion is achieved by setting the aromatic polyamide to 50 ≦ l ≦ 100 and 0 ≦ m ≦ 50. This is preferable because the coefficient can be reduced. In order to reduce the thermal expansion coefficient, in order to reduce the thermal expansion coefficient, it is preferable that the polymer main chain is an aromatic moiety, and the aromatic moiety is more a para bond than an ortho bond or a meta bond. The case where a bond is included is preferable. It is preferable that the main chain has an aromatic portion connected by a para bond, because the main chain can have a rigid structure, and expansion can be suppressed even when a high temperature is applied. Chemical formula (I) is preferable because diamine has a rigid structure having no bending component, and therefore, expansion can be suppressed even at high temperatures.
The laminate of the present invention can be used as a solar cell substrate, a touch panel substrate, a pharmaceutical packaging material, a food packaging material, a beverage packaging material, and the like. Since it has high properties and is excellent in transparency, it can be suitably used for a laminate for display material. Examples of the display material that can use the laminate of the present invention include an organic EL display, an inorganic EL display, a liquid crystal display, electronic paper, a field emission display, and the like.

  When used for these applications, the laminate for display material of the present invention can be used by providing a transparent conductive film. The film used in the laminate of the present invention is a base material having a coefficient of thermal expansion reduced to −15 ppm / ° C. or more and 50 ppm / ° C. or less, and therefore a film of an inorganic compound such as a gas barrier film or a transparent conductive film is formed. However, curling is unlikely to occur. Moreover, since heat resistance is high, when a transparent conductive film is provided, processing at high temperature becomes possible.

  Although the manufacturing method of the laminated body of this invention about the case where aromatic polyamide is used is illustrated below, it is not limited to this.

  Various methods can be used to obtain an aromatic polyamide solution, that is, a film-forming stock solution. For example, a low-temperature solution polymerization method, an interfacial polymerization method, a melt polymerization method, a solid-phase polymerization method, etc. can be used. The low temperature solution polymerization method is preferable from the viewpoint that the solution at the time can be used for film formation as it is and the productivity is excellent.

  Moreover, when superposing | polymerizing using 2 or more types of diamine, one type of diamine is added to a solvent one by one, 10-99 mol% of acid dichloride is added with respect to this diamine, it is made to react, and another diamine is added after this. A stepwise reaction method in which acid dichloride is further added and reacted, and a method in which all diamines are mixed and added, and then acid dichloride is added and reacted can be used.

Further, when two or more kinds of acid dichlorides are used, a stepwise method, a method of adding them simultaneously, and the like can be used. In any case, the molar ratio of total diamine to total acid dichloride is preferably 95 to 105: 105 to 95. More preferably, it is 97-103: 103-97, Most preferably, it is 98.5-101.5: 101.5-98.5. When this value is deviated, the molecular weight of the obtained polymer is lowered, and the elongation, toughness, and heat resistance of the film may be lowered. On the other hand, if this value is deviated, the molecular weight distribution of the polymer may be widened to generate oligomers. When the amount of oligomer production increases, oligomers may aggregate during film formation to become internal foreign matter or blown out to the surface. In such a case, the surface smoothness of the film deteriorates, and defects are likely to occur during the formation of the layer containing the inorganic compound, making it difficult to obtain a high-quality laminate for display material.
Moreover, when making a diamine and an acid dichloride react, it is preferable to add an acid dichloride, cooling the solution which melt | dissolved diamine to 10 degrees C or less. The reaction between diamine and acid dichloride is an exothermic reaction. If the solution is not cooled sufficiently, the degree of polymerization of the polymer is difficult to increase and the molecular weight distribution may be widened. As a result, when the amount of oligomer generated increases, surface defects increase and defects in the layer containing the inorganic compound tend to occur.

  Examples of the solvent used in the production of the aromatic polyamide of the present invention include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, N, N- Acetamide solvents such as dimethylacetamide and N, N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol, o-, m- or p-cresol, xylenol, Phenolic solvents such as halogenated phenols and catechols, and aprotic polar solvents such as hexamethylphosphoramide and γ-butyrolactone, which are preferably used alone or as a mixture, more preferably xylene, Toluene The use of such aromatic hydrocarbons are also possible. From the viewpoint of solubility, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, and γ-butyrolactone can be mentioned. N-methyl-2-pyrrolidone, N, N-dimethylacetamide, and N, N-diethylacetamide are preferable from the viewpoint of easy progress of the polymerization reaction, and the solvent is less likely to be colored even when heated at a high temperature. In particular, N, N-dimethylacetamide and N, N-diethylacetamide are particularly preferred because the yellowness of the film can be lowered.

Examples of the raw acid dichloride include terephthalic acid dichloride, 2 chloro-terephthalic acid dichloride, isophthalic acid dichloride, naphthalene dicarbonyl chloride, biphenyl dicarbonyl chloride, terphenyl dicarbonyl chloride, and the like, particularly preferably terephthalic acid dichloride, 2-chloro-terephthalic acid dichloride and isophthalic acid dichloride.
The aromatic polyamide solution obtained from acid dichloride and diamine contains hydrogen chloride as a by-product, but when neutralizing this, an inorganic neutralizing agent such as calcium hydroxide, calcium carbonate, lithium carbonate, Alternatively, an organic neutralizing agent such as ethylene oxide, propylene oxide, ammonia, triethylamine, triethanolamine, diethanolamine is used. However, in the case of a polymer having low solubility, the polymer may be rapidly precipitated during heating and drying at the time of film formation to make a transparent film. In the case of such a polymer, it is preferable to use an inorganic neutralizing agent that generates an inorganic salt that functions as a dissolution aid by neutralization.

  In order to improve the surface smoothness of the film, it is also preferable to add a leveling agent to the polymer solution. Many of the causes of surface defects include convection phenomenon due to solvent evaporation, adhesion of dust, movement of bubbles and foreign matters to the surface, and the like. The leveling agent functions to increase the surface smoothness of the film by controlling the surface tension.

Furthermore, 10 parts by weight or less of an inorganic or organic additive may be contained with respect to 100 parts by weight of the polymer for the purpose of surface formation, workability improvement, and the like. Additives for the purpose of surface formation, for _{example, SiO 2, TiO 2, Al} 2 O 3 _in the inorganic _{particles, CaSO 4, BaSO 4, CaCO} 3, carbon black, carbon nanotube, fullerene, zeolite, other metallic powder Etc. Preferred organic particles include, for example, particles made of an organic polymer such as crosslinked polyvinylbenzene, crosslinked acrylic, crosslinked polystyrene, polyester particles, polyimide particles, polyamide particles, and fluororesin particles, or the above organic polymer on the surface. Inorganic particles that have been subjected to treatment such as coating may be mentioned.

As other additives, it is also preferable to add an inorganic filler such as glass fiber or glass powder for the purpose of improving heat resistance and dimensional stability. The addition of glass fiber or glass powder is preferable because the heat resistance and dimensional stability of the aromatic polyamide film can be further enhanced. The inorganic filler is preferably 1 to 90 parts by weight, more preferably 30 to 70 parts by weight with respect to 100 parts by weight of the aromatic polyamide. When the amount of the inorganic filler is less than this, the effect of dimensional stabilization due to the composite of the aromatic polyamide and the inorganic material is difficult to occur. On the other hand, when the amount is larger than this, irregularities derived from the inorganic filler are generated on the surface of the molded body due to the difference in thermal expansion coefficient between the resin and the inorganic filler, and the appearance is likely to deteriorate. 1 to 90 parts by weight is preferable because the physical properties can be improved without deterioration of the appearance.
Furthermore, for the purpose of preventing deterioration against ultraviolet rays and improving light resistance, 10 parts by weight or less of an ultraviolet absorber may be contained with respect to 100 parts by weight of the aromatic polyamide. Examples of the ultraviolet absorber include benzophenone, benzotriazole, cyanoacrylate, and benzoate compounds.

  For the purpose of accelerating the dissolution of the polymer, 50 parts by weight or less of an alkali metal or alkaline earth metal salt can be added to the solvent with respect to 100 parts by weight of the polymer.

Next, film formation will be described. The film used in the present invention can be obtained by either the melt casting method or the solution casting method, but it is more preferable to form a film by the solution casting method. In general, the melt film forming method is prone to die lines (streaks), and the resin is likely to stay in the extruder. There is no particular problem, which is preferable in that a superior surface property can be obtained as compared with the melt film-forming method. In the solution film forming method, the film may be formed by any method such as a dry and wet method, a dry method, and a wet method, but a dry and wet method is preferably used. In the following, description will be made by taking an example of film formation by a dry and wet method.
In the case of forming a film by a dry and wet method, it is preferable to finely filter the film-forming stock solution before extruding the film-forming stock solution from the die because fine foreign matters can be removed and the surface can be smoothed. The filtration filter to be used is preferably a filter having a retained particle diameter of 45.0 μm or less, more preferably 5.0 μm or less, and particularly preferably 1.0 μm or less. In addition, as a filter material to be used, a filter made of an inorganic material or a filter made of an organic material is used. Even if the filtration accuracy is the same, the capture performance varies depending on the material of the filter. Therefore, it is also preferable to use an inorganic filter and an organic filter in combination. In the case of non-filtration, foreign matters or the like mixed during polymerization may form protrusions on the film, and the gas barrier property of the laminate provided with a layer containing an inorganic compound may be lowered.

  Further, the degree of cleanness of the film forming environment after filtration is preferably a class of 10,000 or less, more preferably a place where the cleanness is controlled to a class of 1,000 or less. When film formation is performed in an environment where the degree of cleanliness is inferior, dust tends to be mixed into the film, and in that case, surface smoothness may be inferior, which may be disadvantageous for the formation of a layer containing an inorganic compound.

  When extruding a film-forming stock solution from a die onto a support such as a drum, an endless belt, a film-forming substrate film, or glass, it is preferable to control the surface smoothness of the support, and use a support with scratches or the like. Then, a damage | wound may be transcribe | transferred to a film and it may be inferior to surface smoothness.

  The film-forming stock solution extruded onto the support is dried until the solvent is scattered by heating and the film is self-holding. If the drying temperature is set to be high at this time, the evaporation of the solvent may rapidly progress and the surface smoothness may be deteriorated, and it may become a defect when it adheres to the support and peels off. In addition, when the temperature is high, drying tends to proceed only on the film surface, and when a thick film that can be used as a film is formed, there may be a difference in the dry state between the film surface and the inside. In this case, since the inside is incompletely dried, the film may become cloudy when introduced into the next wet process. Therefore, in the initial stage of drying, drying is preferably performed at a temperature about 20 ° C. lower than the boiling point of the solvent. In order to shorten the film forming time, a method of gradually increasing the drying temperature is preferable.

  In order to facilitate the peeling from the support and suppress the decrease in surface smoothness due to the rapid infiltration of water in the next wet process, the polymer concentration when introduced into the wet process immediately after peeling from the support Is preferably 47% by weight to 63% by weight, particularly preferably 50% by weight to 60% by weight. The polymer concentration when introduced into the wet process immediately after peeling from the support is the polymer concentration of the film after the solvent has been reduced by heat drying before being introduced into the wet process. Minute weight / total weight in the film when introduced into the wet process) × 100%. When the polymer concentration when introduced into the wet process immediately after peeling from the support is less than 47% by weight, it is difficult to peel off the film due to insufficient drying, and the film may be elongated at the time of peeling. Furthermore, in a wet process, surface smoothness may deteriorate due to rapid water penetration. For thin films with a thickness of less than 10 μm, the polymer concentration at the time of peeling is optimally around 40% by weight, but in the case of thicker films than that, there is a difference between the film surface structure during drying and the internal structure, and only the surface proceeds with drying The inside tends to be undried. In such a case, since the surface is hardened, there is no problem in peelability, but water may suddenly penetrate into the film in a wet tank and the film may become cloudy. Also, when the polymer concentration when introduced into the wet process immediately after peeling from the support is greater than 63% by weight, it takes a long time for drying by heating and is inferior in productivity, and only the film surface is hardened too much in the wet tank. It becomes difficult for water to penetrate and it becomes difficult to remove the solvent inside the film during extraction with water. Further, during heat drying, the salt may precipitate on the surface as the solvent volatilizes, and the film surface properties may deteriorate.

The film peeled from the support and introduced into the wet process is desalted and desolvated in a wet bath. However, when the film is washed with water at room temperature, if the film thickness is 10 μm or more, it is difficult to reduce the residual solvent in the film, and an inorganic salt dissolution aid such as lithium chloride may remain inside the film. In order to efficiently reduce the amount of residual solvent in the film, it is important to use a wet bath containing an aqueous solution having a water temperature of 35 ° C. or higher and 90 ° C. or lower. However, when the film immediately after peeling from the support is placed in a wet bath at 35 ° C. or more and 90 ° C. or less, the surface property may deteriorate due to the rapid extraction of the solvent.
In order to reduce the amount of residual solvent while smoothing the surface, desalting and desolvation are promoted in the first wet tank in which the temperature of the first wet tank is 0 ° C. or higher and lower than 35 ° C. after peeling from the support. Then, the method of introducing into the second wet bath of 35 ° C. or higher and 90 ° C. or lower, that is, the method of gradually increasing the water temperature of the wet bath is preferable.
Here, a 1st wet tank means the tank containing the aqueous solution whose temperature is 0 degreeC or more and less than 35 degreeC, and may be comprised by a single tank or may be comprised by several tanks.
In the case where the first wet tank is constituted by a single tank, if the circulation equipment for the aqueous solution is insufficient, the solvent and the salt that have escaped from the film are likely to accumulate in the wet tank, and the desalting and desolvating properties with time descend. In such a case, it is not preferable to pass through a single wet tank for a long time, and the first wet tank is preferably composed of a plurality of tanks. In this case, it is preferable that the temperature of the tank subsequent to the first wet tank is the same as or slightly higher than that of the first tank. As a result, salt and solvent are not accumulated intensively in the first wet tank, and problems are less likely to occur even when the aqueous solution circulation facility is low. In addition, the second wet tank refers to a tank containing an aqueous solution having a temperature of 35 ° C. or higher and 90 ° C. or lower, and may be configured as a single tank or a plurality of tanks. At this time, the polymer concentration when introduced into the second wet tank is preferably 80% by weight or more. When the aqueous solution temperature of the second wet bath is lower than 35 ° C., salt may remain in the finally obtained film, and when blown to the film surface, it is disadvantageous in forming a film containing an inorganic compound. Moreover, it may become a residual solvent. In this case, the solvent may be ejected during use or processing. When the temperature of the aqueous solution in the second wet tank is higher than 90 ° C., the film surface may be roughened due to partially generated water vapor. It is preferable to use a wet bath at 35 to 90 ° C. because desalting and desolvation can be efficiently advanced.

  When introducing into the second wet bath containing an aqueous solution of 35 ° C. or higher and 90 ° C. or lower, the polymer concentration of the film is preferably 80% by weight or higher. This polymer concentration is the polymer concentration of the film after the solvent has been reduced just before being introduced into a wet bath containing an aqueous solution of 35 ° C. or higher and 90 ° C. or lower, (solid content weight in final film / 35 ° C. or higher) The total weight in the film before being introduced into a wet bath containing an aqueous solution of 90 ° C. or less) × 100%. When the polymer concentration is lower than 80% by weight, the film surface property may be lowered in a wet bath of 35 ° C. or more and 90 ° C. or less. There is no particular upper limit for the concentration, and there is no problem as long as the concentration is 100% by weight. However, when the polymer concentration is higher than 96% by weight, it is necessary to take a long time to achieve this concentration only by the wet process, particularly for a film of 10 μm or more. And productivity may be inferior.

  The aqueous solution in the wet bath may be only water, but it is also possible to use it in a mixed system by putting an organic solvent such as N, N-dimethylacetamide, N-methyl-2-pyrrolidone in water. . By using a mixed system with an organic solvent, the removal rate of the solvent is reduced, but the removal of the oligomer proceeds effectively, and the adhesion of the oligomer to the inside or the surface can be prevented.

  Moreover, it is preferable to use the pure water which does not contain a metal part for the water in a wet tank. When heat treatment is performed in a state where tap water containing a large amount of metal adheres to the film surface, the metal component remains on the surface as a defect, and the gas barrier property may be inferior when a laminate is formed.

In the above description, it has been described that at least the first and second wet baths are provided in the wet process, but a third wet bath may be further provided after the second wet bath. In this case, the third wet tank is a tank containing a solution having a temperature of less than 35 ° C., and may be a single tank or a plurality of tanks.
After the wet process, the film is further stretched and heat-treated to form a film. The polymer concentration at the end of the wet process is preferably 96% by weight to 100% by weight. Here, the polymer concentration at the end of the wet process is the polymer concentration of the film after the solvent is reduced in the wet tank, (solid content weight in the final film / total weight in the film at the end of the wet process) × 100% It is. When the polymer concentration at the end of the wet process is 96% by weight or less, the solvent tends to remain in the film by the heat treatment after the wet process.
Moreover, said aromatic polyamide film can be used conveniently also as an unstretched film.
The heat treatment is preferably performed at 200 to 500 ° C. for several seconds to several minutes. If it is less than 200 ° C., the heat treatment is not sufficient, the surface hardness and Young's modulus of the film may decrease, and the solvent may remain in the film. Moreover, when it exceeds 500 degreeC, a film may color.
As described above, a polymer film, particularly an aromatic polyamide film, is preferably formed by a dry and wet film forming method and includes the following steps because the solvent hardly remains and the film surface is easily smoothed.

  (1) The polymer concentration when introduced into the wet process is 47% by weight or more and 63% by weight or less.

  (2) A wet bath used in the wet process includes at least a first wet bath containing an aqueous solution of 0 ° C. or higher and lower than 35 ° C. and a second wet bath containing an aqueous solution of 35 ° C. or higher and 90 ° C. or lower. .

  (3) The polymer concentration of the film when transported to the second wet tank is 80% by weight or more.

  (4) The polymer concentration of the film when transported from the final wet bath to the heating step is 96% by weight or more.

  In the present invention, a conventionally known surface treatment can be applied to one side or both sides of the film for the purpose of improving the adhesion with the flattening layer or the layer containing an inorganic compound. Examples of the surface treatment include, but are not limited to, plasma treatment, corona discharge treatment, and ultraviolet irradiation treatment.

  Next, formation of the planarizing layer will be described. When the film surface is inferior in smoothness, it is preferable to form a planarization layer. As a planarizing layer, polysilazane or inorganic polymer compounds such as metal oxides by sol-gel method, aromatic polyamide, polyamic acid, polyimide resin, polyamideimide resin, polyethersulfone resin, polyethylene resin, melamine resin, polyurethane resin Polyester resin polyurea resin, polycarbonate resin, polyacrylic acid resin, polyacrylic acid ester resin, polymethacrylic acid resin, polymethacrylic acid ester resin, modified acrylic resin, maleimide resin, polystyrene resin, polyacrylonitrile resin, epoxy resin, etc. It is possible to use the same polymer as the film, or the same type and different composition. For example, an aromatic polyamide film is preferably formed by applying an aromatic polyamide solution having the same composition or an aromatic polyamide solution having a different composition to the planarizing layer. In order to apply the resin solution, methods such as a spin coater, a roll coater, a gravure coater, and a metabar can be used.

  As the solvent of the resin solution used when forming the planarizing layer, a solvent having a relatively low solubility in the film is preferable. In the case of a solvent having a high solubility in the film, the surface of the film is dissolved when forming the flattening layer, the surface property of the film deteriorates, and unevenness occurs at the interface between the film and the flattening layer. There are things that cannot be done. When a flattening layer made of aromatic polyamide is provided on the aromatic polyamide film, it is preferable not to add a salt such as lithium chloride to the flattening layer forming solution. This is because when the salt is contained, the solubility of the aromatic polyamide film is increased, and therefore the film surface may be dissolved. Moreover, in order to remove the salt, it is preferable that no salt is contained from the point that a water washing step is required. By not containing a salt, a planarization layer can be formed without providing a water washing step, which is preferable.

Next, formation of the gas barrier layer will be described.
When a layer containing an inorganic compound is formed as the gas barrier layer, a plasma CVD method, a catalytic CVD method, a thermal CVD method, a sputtering method, an ion plating method, a vacuum deposition method, a reactive deposition method, an ion beam assisted deposition method, or the like is used. be able to. As the inorganic compound, it is preferable to use metal oxides such as silicon, aluminum, indium, tin, zinc, titanium, and tantalum, nitrides, oxynitrides, and mixtures thereof.

  When a gas barrier layer having a multilayer structure is provided by providing a layer containing a polymer compound, the layer containing the polymer compound can be formed by a dry forming method such as sputtering, vacuum deposition, ion plating, chemical vapor deposition, or roll. It can be formed by a method such as coating, gravure coating, gravure reverse coating, slit coating, knife coating, dip coating, spray coating, or die coating. Preferably, the polymer compound layer is preferably formed by coating and subsequent solvent drying from the viewpoint that the polymer compound can easily fill in the defect sites such as pinholes in the layer made of the inorganic compound. As a layer containing a polymer compound, an inorganic polymer compound such as polysilazane or metal oxide by sol-gel method, aromatic polyamide, polyamic acid, polyimide resin, polyamideimide resin, polyethersulfone resin, polyethylene resin, melamine resin , Polyurethane resin, polyester resin polyurea resin, polycarbonate resin, polyacrylic acid resin, polyacrylic acid ester resin, polymethacrylic acid resin, polymethacrylic acid ester resin, modified acrylic resin, maleimide resin, polystyrene resin, polyacrylonitrile resin, epoxy Resin, etc. can be used, but high temperature heat treatment is possible at the time of molding and processing by using a compound having high heat resistance. Therefore, polysilazane, aromatic polyamide, polyamic acid, polyimide resin, polyamide imi Resins, polyether sulfone resins and the like are preferably used. When polysilazane is used, for example, it is dissolved in dibutyl ether and applied and dried at a predetermined temperature to form a coating film.

  Hereinafter, the present invention will be described by way of examples. The characteristics were measured and evaluated by the following methods.

(1) Light transmittance The transmittance | permeability corresponding to the wavelength 450-700 nm light of a laminated body was measured using the UV measuring device and U-3410 (made by Hitachi Measurement Co., Ltd.), and the following methods evaluated.

Transmittance (%) = (T3 / T2) × 100
However, T3 is the intensity | strength of the light which passed the sample, and T2 is the intensity | strength of the light which passed the air of the same distance except not passing a sample. In addition, the measurement was performed after the apparatus was started for 30 minutes and the light source was stabilized.

Measurement wavelength: 450-700 nm
Measurement mode: Transmission ○: The transmittance is 80% or more and 100% or less in the entire wavelength region of 450 nm to 700 nm. X: There is a wavelength of the transmittance of 0% or more and less than 80% at some wavelengths of 450 nm to 700 nm (2) Thermal expansion coefficient Using TMA, SS6000 (manufactured by Seiko Instruments Inc.), the film was measured under the following conditions, and the thermal expansion coefficient was determined from the range of 30 ° C to 100 ° C in the second temperature raising step. In the following temperature lowering step (120 ° C. to 25 ° C.), liquid nitrogen was used to lower the temperature.

1. Range: 25 ° C. to 120 ° C., speed: 5 ° C./min, holding time: 5 minutes Range: 120 ° C. to 25 ° C., speed: 5 ° C./min, holding time: 5 minutes Range: 25 ° C. to 120 ° C., speed: 5 ° C./min, holding time: 5 minutes Range: 120 ° C. to 25 ° C., speed: 10 ° C./min, holding time: 5 minutes Moreover, in order to evaluate the usability of the film at a high temperature, the coefficient of thermal expansion was also determined for the range of 100 ° C. to 200 ° C.

1. Range: 25 ° C. to 250 ° C., speed: 5 ° C./min, holding time: 5 minutes Range: 250 ° C to 25 ° C, speed: 5 ° C / min, holding time: 5 minutes Range: 25 ° C. to 250 ° C., speed: 5 ° C./min, holding time: 5 minutes Range: 250 ° C. to 25 ° C., speed: 10 ° C./min, holding time: 5 minutes (3) Glass transition temperature Using DMA, DMS6100 (manufactured by Seiko Instruments Inc.), the film is measured under the following conditions, The maximum value of tan δ was taken as the glass transition temperature.

Frequency 1 Hz, measuring temperature 25 ° C. to 360 ° C., heating rate 2 ° C./min (4) Surface roughness Using AFM and MM-SPM (manufactured by Digital Instruments), Ra of the film was measured under the following conditions. The measurement was performed in an environment of 23 ° C. and 65% RH. The cut-off was not set.

Measurement area: 30 μm × 30 μm
Measurement speed: 0.5Hz
(5) Yellowness (YI value)
Using SPECTRO COLOR METER SE 2000 (Nippon Denshoku Industries Co., Ltd.), the yellowness of the film was measured according to the following formula (X, Y, and Z are tristimulus values transmitted through the test piece). The measurement was performed after the apparatus was started for 30 minutes and the light source was stabilized. The measurement was performed in an environment of 23 ° C. and 65% RH.
YI value: YI = [100 (1.28X−1.06Z) / Y]
Measurement mode: Permeation (6) Water vapor transmission rate The water vapor transmission rate of the laminate was measured using a moisture permeability measuring device PERMATRAN-W3 / 30 (manufactured by Mocon). Here, the measurement lower limit of the apparatus is 0.01 g / m ² / day.

Measurement temperature: 40 ° C
Measurement humidity: 90% RH
Measurement area: 5 cm ² (using aluminum mask foil (MC025-493 (Hitachi Instrument Service Co., Ltd.))
(7) Polymer concentration The polymer concentration is defined by (solid weight / total weight) × 100%. The polymer concentration (referred to as PC1) when introduced into the wet process immediately after peeling from the support is the polymer concentration after the solvent is reduced by heat drying before being introduced into the wet process (final film Medium solids weight / total weight in film when introduced into wet process) × 100%. The measurement method of PC1 is described. The film weight (W1) immediately after peeling from the substrate is measured. Subsequently, after washing in a wet bath containing water at 80 ° C. for 60 minutes, heat treatment is performed at 340 ° C. for 1 minute, and the weight (W2) is measured again. According to the following formula, the polymer concentration was set to PC1 when introduced into the wet process immediately after peeling from the support.

PC1 = (W2 / W1) × 100 (%)
The polymer concentration (referred to as PC2) when introduced into the second wet bath containing an aqueous solution of 35 ° C. or higher and 90 ° C. or lower is immediately before being introduced into the wet bath containing an aqueous solution of 35 ° C. or higher and 90 ° C. or lower. It is the polymer concentration of the film after the reduction of the solvent, (solid content weight in the final film / total weight in the film before being introduced into the wet bath containing an aqueous solution of 35 ° C. or more and 90 ° C. or less) × 100% Determined by The polymer concentration at the end of the wet process (referred to as PC3) is the polymer concentration of the film after the solvent is reduced in the wet bath, (solid content weight in the final film / total weight in the film at the end of the wet process) X Determined at 100%. The measuring method of PC2 and PC3 is described. Using a thermogravimetric measuring device TGA-50 (manufactured by Shimadzu Corporation) and thermal analysis system TA-50 (manufactured by Shimadzu Corporation) under a nitrogen stream of 50 ml / min, from room temperature (22 ° C to 24 ° C) to 10 ° C / min. PC2 and PC3 according to the following formulas, starting from the measurement with the rate of temperature rise, with the weight loss from room temperature to 110 ° C. (W3) adhering to the moisture in the wet bath and the weight reduction from 110 ° C. to 340 ° C. (W4) as the solvent amount It was.

PC2, PC3 = ((100−W3−W4) / (100−W3)) × 100 (%)
(8) Coloring evaluation of laminate The transmittance YI value of the laminate was measured by the same method as in (1) above, and evaluated by the following method.

○: YI value ≦ 3.5
Δ: 3.5 <YI value ≦ 5.0
X: 5.0 <YI value (9) Heat-resistant evaluation of laminated body The laminated body of a 10 cm x 10 cm size was heated in oven set to 120 degreeC for 3 hours. Subsequently, after standing at room temperature for 15 minutes, it is spread on a horizontal plane so that the top is concave and the bottom is convex. In these cases, the distance of the highest position where the end of the laminate (four corners) was lifted from the horizontal plane was measured, and the average distance of the four points was obtained. This average distance was determined according to the following criteria. Here, when curling until the two opposite sides of the laminated body overlap, it was set as x in the following criteria.

○: 0 cm (no lifting)
Δ: Floats in the range of greater than 0 cm to 0.5 cm or less. X: Floats higher than 0.5 cm. (10) Moisture resistance evaluation of the laminated body A 10 cm × 10 cm size laminated body is set to a temperature of 60 ° C. and a humidity of 90% RH. It was stored in a humidity chamber LH31-14P (Nagano Scientific Machinery Co., Ltd.) for 7 days. Subsequently, after standing at room temperature for 15 minutes, it is spread on a horizontal plane so that the top is concave and the bottom is convex. In these cases, the distance of the highest position where the end of the laminate (four corners) was lifted from the horizontal plane was measured, and the average distance of the four points was obtained. This average distance was determined according to the following criteria. Here, when curling until the two opposite sides of the laminated body overlap, it was set as x in the following criteria.

○: 0 cm (no lifting)
Δ: Floats in the range of greater than 0 cm and 0.5 cm or less ×: Floats higher than 0.5 cm (11) Gas barrier property evaluation The water vapor permeability measured by the method shown in (7) above was determined according to the following. By making the water vapor transmission rate 1.0 * 10 < ^-1 > g / m < ² > / day or less, it becomes possible to use it in fields requiring water vapor barrier properties more than conventional food packaging applications. The following criteria were provided from the point that it can be used for display material applications by setting it to less than 0 × 10 ⁻² g / m ² / day.

○: Less than 1.0 × 10 ⁻² g / m ² / day Δ: 1.0 × 10 ⁻² g / m ² / day or more, 1.0 × 10 ⁻¹ g / m ² / day or less ×: 1 Greater than 0.0 × 10 ⁻¹ g / m ² / day (Example 1)
[Polymer polymerization for film]
In dehydrated N, N-dimethylacetamide, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl corresponding to 100 mol% with respect to acid dichloride was dissolved and sufficiently cooled with ice, 2-chloroterephthalic acid chloride corresponding to 100 mol%, which is the same amount as the diamine, was added and polymerized by stirring for 2 hours. And it neutralized using 100 mol% lithium carbonate with respect to generated hydrogen chloride. The resulting solution was an aromatic polyamide solution having a polymer concentration of 10% by weight.

  The obtained polymer solution was filtered through a filter having a reserved particle diameter of 45 μm, and then filtered through a filter having a reserved particle diameter of 1 μm to obtain a film forming stock solution.

[Film formation]
The obtained aromatic polyamide solution having a polymer concentration of 10% by weight is cast on a glass plate with a bar coater in an environment where the cleanness is maintained at class 1,000, and dried in an oven at 120 ° C. for 15 minutes. The solvent was evaporated, and the polymer sheet exhibiting self-supporting property was peeled from the support. Subsequently, the peeled sheet is passed through a wet bath containing pure water at 15 ° C. for 5 minutes, and further passed through a wet bath containing pure water heated to 70 ° C. for 15 minutes. The water was extracted. Thereafter, heat treatment was performed for 1 minute in an oven at a temperature of 280 ° C. while keeping both widths of the film constant, and an aromatic polyamide film having a thickness of 51 μm, which was the film of Example 1, was obtained.

  At this time, PC1 = 56 wt%, PC2 = 89 wt%, and PC3 = 99 wt%. Moreover, it became a transparent film excellent in surface smoothness, glass transition temperature, and thermal expansion coefficient.

[Formation of a layer containing an inorganic compound]
A first layer containing an inorganic compound was applied to the film using a sputtering apparatus. The layer containing an inorganic compound was formed on the side excellent in surface smoothness of the film. As a target inorganic compound, silicon oxide is used. Argon is used as an introduced gas, a sputtering vacuum degree is 2.0 × 10 ⁻³ Torr, an input power is 2.5 kW, and a layer containing an inorganic compound of 30 nm is formed at a substrate temperature of 200 ° C. did.

  Subsequently, a polymer film was formed on the layer containing the inorganic compound. A dibutyl ether solution of perhydropolysilazane was applied using a metabar, heated at 50 ° C. for 5 minutes, and then heated at 150 ° C. for 1 hour to form a layer containing a polymer compound.

  Subsequently, a silicon oxide film having a thickness of 30 nm was formed by sputtering under the same conditions as the formation of the first layer containing the inorganic compound, whereby the laminate of Example 1 was obtained.

  The obtained laminate was a high-quality laminate that was excellent in transparency and water vapor barrier properties and did not cause curling.

(Example 2)
A layer containing an inorganic compound, a layer containing a polymer compound, and a layer containing an inorganic compound were sequentially formed on both surfaces of the film of Example 1 in the same manner as in Example 1 to obtain a laminate of Example 2. .

  The obtained laminate was a laminate having excellent transparency, no curling, and excellent water vapor barrier properties.

(Example 3)
In Example 1, aromatics were used in the same manner as in Example 1 except that 25 mol% of isophthalic acid dichloride, 75 mol% of 2-chloroterephthalic acid chloride were used as the acid dichloride, and N-methyl-2-pyrrolidone was used as the solvent. A polyamide solution was obtained.

  Further, in the film forming method of Example 1, a 50 μm film of Example 3 was obtained in the same manner as in Example 1 except that drying at 120 ° C. was performed for 45 minutes and a wet bath at 70 ° C. was set for 40 minutes. It was.

  At this time, PC1 = 55 wt%, PC2 = 90 wt%, and PC3 = 99 wt%. Moreover, although the thermal expansion coefficient was somewhat inferior to Example 1, it became a film excellent in glass transition temperature, low surface roughness, and excellent in transparency.

  Using this aromatic polyamide film, in the same manner as in Example 1, a layer containing an inorganic compound, a layer containing a polymer compound, and a layer containing an inorganic compound were formed in this order to obtain a laminate of Example 3. .

  The obtained laminate was a laminate having sufficient values, although transparency and curling were not generated, and the water vapor barrier property was slightly inferior to that of Example 1.

Example 4
A polymer solution was obtained in the same manner as in Example 1 except that the polymer solution was filtered only with a 45 μm filter. Further, in the film forming method of Example 1, a 50 μm film of Example 4 was obtained in the same manner except that the film was formed in a class 10,000 environment.

  At this time, PC1 = 54 wt%, PC2 = 88 wt%, and PC3 = 99 wt%. Further, although the surface smoothness was somewhat inferior to that of Example 1, the film had a high glass transition temperature, a high thermal expansion coefficient, and excellent transparency.

  Then, it carried out similarly to Example 1, the layer containing an inorganic compound, the layer containing a high molecular compound, and the layer containing an inorganic compound were formed in order, and the laminated body of Example 4 was obtained.

  The obtained laminate was excellent in transparency, no curling, and had a sufficient value although the water vapor barrier property was slightly inferior to that of Example 1.

(Example 5)
Polymerization was carried out in the same manner as in Example 1 except that the polymer solution was filtered only with a filter having a retained particle diameter of 45 μm to obtain a film-forming stock solution of Example 5.

  Subsequently, the film was formed in the same manner as in Example 1 except that the film was formed at a place where the cleanness was not particularly controlled, and the film of Example 5 was obtained.

  At this time, PC1 = 55 wt%, PC2 = 88 wt%, and PC3 = 99 wt%. Although it was excellent in thermal expansion coefficient, light transmittance, and glass transition temperature, it became a film having a large surface roughness.

  Next, the resin solution for the planarization layer was adjusted. Methylene chloride was added to polymethyl methacrylate and dissolved to obtain a planarization layer forming solution having a polymer concentration of 2.3% by weight.

  Subsequently, a planarization layer was formed. A flattening layer forming solution was applied to the low surface roughness side of the film using a metabar, and the flattening layer was formed by heating at 50 ° C. for 1 minute. At this time, by forming a polymethylmethacrylate thin film having a low refractive index on an aromatic polyamide having a high refractive index, the planarization layer also exhibited an effect as an antireflection layer, and transparency by visual observation was improved.

  A layer containing an inorganic compound is formed on this film in the same manner as in Example 1 except that the substrate temperature is 100 ° C., followed by heating at 50 ° C. for 5 minutes and then heating at 100 ° C. for 3 hours. Except for this point, a layer containing a polymer compound was formed in the same manner as in Example 1. Further, a layer containing an inorganic compound was formed at a substrate temperature of 100 ° C. to obtain a laminate of Example 5.

  The obtained laminate was a laminate having excellent transparency and no curl, but poor water vapor barrier properties.

(Example 6)
9,9 bis (3-fluoro-4-aminophenyl) fluorene corresponding to 100 mol% was dissolved in dehydrated N, N-dimethylacetamide, sufficiently cooled with ice, and then corresponding to 100 mol% 2- Chloroterephthalic acid dichloride was added and polymerized by stirring for 2 hours. After ice cooling again, benzoyl chloride corresponding to 0.2 mol% was added, and the mixture was further stirred for 1 hour. After stirring, neutralization was performed using 100 mol% lithium carbonate with respect to the generated hydrogen chloride. The resulting solution was an aromatic polyamide solution having a polymer concentration of 20% by weight.

  The obtained solution was filtered in the same manner as in Example 1 to obtain a film-forming stock solution of Example 6.

  Subsequently, film formation was performed in the same manner as in Example 1 using the obtained film-forming stock solution, and a film of Example 6 was obtained.

  At this time, PC1 = 53 wt%, PC2 = 86 wt%, PC3 = 99 wt%, and the surface roughness and glass transition temperature were excellent. Moreover, although it was inferior to a thermal expansion coefficient and light transmittance, it was a grade which does not become a problem in practical use.

  In the same manner as in Example 1, a layer containing an inorganic compound, a layer containing a polymer compound, and a layer containing an inorganic compound were formed in this order on this film to obtain a laminate of Example 6.

  Although the obtained laminate was excellent in water vapor barrier properties, it was slightly inferior in transparency and flatness as compared with Example 1, but became a laminate having a sufficient value.

(Comparative Example 1)
The film of Example 1 having no planarization layer or gas barrier layer was used as the film of Comparative Example 1.

  Although the obtained film was excellent in transparency and no curling occurred, the water vapor barrier property was poor.

(Comparative Example 2)
A film was formed in the same manner as in Example 1 except that the step of passing the polymer solution of Example 1 through a wet bath containing pure water at 15 ° C. for 15 minutes was omitted, and 51 μm as Comparative Example 2 was formed. Film was obtained.

  At this time, PC1 = 56 wt% and PC3 = 99 wt%. Although it was excellent in thermal expansion coefficient, light transmittance, and glass transition temperature, it became a film with high surface roughness. This is considered to be that the film was poor in surface roughness because it was introduced into a wet bath at 70 ° C. immediately after drying at 120 ° C., and the solvent extraction progressed rapidly.

  In the same manner as in Example 1, a layer containing an inorganic compound, a layer containing a polymer compound, and a layer containing an inorganic compound were formed in this film in this order to obtain a laminate of Comparative Example 2.

  The obtained laminate was a laminate having excellent transparency and no curl, but poor water vapor barrier properties.

(Comparative Example 3)
The polymer solution of Example 1 was formed according to the film forming method of Example 1 with no filtration, and the film of Comparative Example 3 was obtained.

  At this time, PC1 = 56 wt%, PC2 = 86 wt%, and PC3 = 99 wt%. Although it was excellent in thermal expansion coefficient, light transmittance, and glass transition temperature, it became a film with high surface roughness. This is thought to be due to unfiltered.

  In the same manner as in Example 1, a layer containing an inorganic compound, a layer containing a polymer compound, and a layer containing an inorganic compound were formed in this film in order to obtain a laminate of Comparative Example 3.

  The obtained laminate was a laminate having excellent transparency and no curl, but poor water vapor barrier properties.

(Comparative Example 4)
A film of Comparative Example 4 was obtained according to the film forming method of Example 1, except that the drying time at 120 ° C. was 9 minutes in Example 1.

  At this time, PC1 = 44% by weight, PC2 = 86% by weight, and PC3 = 99% by weight. Although it was excellent in thermal expansion coefficient, light transmittance, and glass transition temperature, it became a film with high surface roughness. This is presumably because the product was introduced into the wet bath in an incomplete state after drying at 120 ° C.

  A planarized layer, a layer containing an inorganic compound, a layer containing a polymer compound, and a layer containing an inorganic compound were formed in this film in the same manner as in Example 1 to obtain a laminate of Comparative Example 4.

  The obtained laminate was a laminate having excellent transparency and no curl, but poor water vapor barrier properties.

(Comparative Example 5)
In Example 3, the aromatic polyamide solution was used unfiltered, and the film was formed in a place where the cleanness was not particularly controlled. A film was obtained.

  At this time, PC1 = 53 wt%, PC2 = 88 wt%, and PC3 = 99 wt%. Although it was excellent in thermal expansion coefficient, light transmittance, and glass transition temperature, it became a film with a little large surface roughness.

  A planarized layer, a layer containing an inorganic compound, a layer containing a polymer compound, and a layer containing an inorganic compound were formed in this film in the same manner as in Example 1 to obtain a laminate of Comparative Example 5.

  The obtained laminate was a laminate having excellent transparency and no curl, but poor water vapor barrier properties.

(Comparative Example 6)
Example, except that 2-chloroparaphenylenediamine corresponding to 35 mol% as diamine, 4,4′-diaminodiphenyl ether corresponding to 65 mol%, and 2-chloroterephthalic acid chloride corresponding to 100 mol% as acid dichloride are used. 3 and a film of Comparative Example 6 having a thickness of 53 μm was obtained.

  At this time, PC1 = 53 wt%, PC2 = 88 wt%, and PC3 = 99 wt%. Although it was excellent in thermal expansion coefficient, light transmittance, glass transition temperature, and surface roughness, it became a film inferior in transparency.

  A planarized layer, a layer containing an inorganic compound, a layer containing a polymer compound, and a layer containing an inorganic compound were sequentially formed on this film in the same manner as in Example 1 to obtain a laminate of Comparative Example 6.

  The obtained laminate was free from curling and excellent in water vapor barrier properties, but was inferior in transparency.

(Comparative Example 7)
Comparative Example as in Example 5 except that a layer containing an inorganic compound, a layer containing a polymer compound, and a layer containing an inorganic compound were formed on the film of Example 5 without providing a planarizing layer. A laminate of 7 was obtained.

  The obtained laminate was excellent in transparency and no curling, but was not provided with a planarizing layer, so that the physical properties of the gas barrier film were inferior and the water vapor barrier property was inferior.

(Comparative Example 8)
TOPAS manufactured by Polyplastics Co., Ltd. was dissolved in methyl ethyl ketone to obtain a polymer solution having a polymer concentration of 20% by weight.

  Subsequently, a film was formed. The obtained polymer solution having a polymer concentration of 20% by weight is cast on a glass plate with a bar coater in an environment where the cleanness is maintained at class 1,000, and dried in an oven at 50 ° C. for 15 minutes. The polymer sheet exhibiting self-supporting property was peeled off from the support. Subsequently, the peeled sheet was heated in an oven at 80 ° C. for 15 minutes, in an oven at 100 ° C. for 20 minutes, in an oven at 120 ° C. for 20 minutes, and in an oven at 170 ° C. for 30 minutes. Got.

  Although it became the transparent film excellent in surface smoothness, it became a film with a high thermal expansion coefficient.

  A layer containing an inorganic compound is formed on this film in the same manner as in Example 1 except that the substrate temperature is 100 ° C., followed by heating at 50 ° C. for 5 minutes and then heating at 100 ° C. for 3 hours. Except for this point, a layer containing a polymer compound was formed in the same manner as in Example 1. Further, a layer containing an inorganic compound was formed at a substrate temperature of 100 ° C. to obtain a laminate of Comparative Example 8.

  Although the obtained laminate was excellent in transparency, it was curled.

Claims (16)

A laminate in which a layer containing an inorganic compound is formed on at least one side of a film containing a polymer, wherein the film has a thermal expansion coefficient of 30 to 100 ° C. of −15 ppm / ° C. to 50 ppm / ° C. A laminate in which at least one in-plane direction exists and the laminate has a light transmittance of 80% to 100% for light of all wavelengths from 450 nm to 700 nm. The laminated body of Claim 1 whose glass transition temperature of a film is 120 degreeC or more. The laminate according to claim 1, wherein the film does not exhibit a glass transition temperature. The film has at least one of the two directions in which the coefficient of thermal expansion of 30 to 100 ° C is -15 ppm / ° C or more and 50 ppm / ° C or less in any of the two orthogonal directions in the film plane. The laminated body in any one of 1-3. The laminated body in any one of Claims 1-4 whose thickness of a film is 10-300 micrometers. The laminated body in any one of Claims 1-5 in which the planarization layer is provided between the film and the layer containing an inorganic compound. The laminated body in any one of Claims 1-6 in which the layer containing a high molecular compound is provided. Ra1 and Ra2 satisfy | fill following Formula (1)-(3), when the surface roughness of one surface of a film is set to Ra1, and the surface roughness of the other surface is set to Ra2, Claim 1 The laminated body in any one of 7.
Ra1 <Ra2 (1)
0 nm <Ra1 ≦ 2 nm (2)
0 nm <Ra2 ≦ 3 nm (3) The laminated body in any one of Claims 1-8 whose yellowness (YI) of a film is 0 or more and 4.5 or less. The laminated body according to any one of claims 1 to 9, wherein a height of floating at an end portion when the laminated body is heated at 120 ° C for 3 hours is 0.5 cm or less. The layered product according to any one of claims 1 to 10, wherein the height of the floating of the end portion generated after storage of the layered product at 60 ° C and 90% RH for 7 days is 0.5 cm or less. The laminated body in any one of Claims 1-11 in which the film contains aromatic polyamide. When the aromatic polyamide includes structural units represented by the chemical formula (I) and the chemical formula (II), and the molar fraction of each structural unit is 1 and m, 50 ≦ l ≦ 100 and 0 ≦ m ≦ 50 The layered product according to claim 12 which is.

R ₁ : —CF ₃ , —CCl ₃ , —CBr ₃ , —F, —Cl, —Br, —OH, —OCH ₃ (however, structural units having these groups may be mixed in the molecule) .)
R _2: any aromatic radical R _3: hydrogen, halogen or a hydrocarbon group having 1 to 3 carbon atoms

R ₄ : Arbitrary aromatic group R ₅ : Arbitrary aromatic group The laminated body in any one of Claims 1-13 whose water vapor permeability is 1.0 * 10 < ^-1 > g / m < ² > / day or less. The display material using the laminated body in any one of Claims 1-14. The manufacturing method of the laminated body in any one of Claims 1-14 by which the film is formed into a film by the dry-wet solution film forming method, and includes the following processes.
(1) The polymer concentration when introduced into the wet process is 47% by weight or more and 63% by weight or less.
(2) A wet bath used in the wet process includes at least a first wet bath containing an aqueous solution of 0 ° C. or higher and lower than 35 ° C. and a second wet bath containing an aqueous solution of 35 ° C. or higher and 90 ° C. or lower. .
(3) The polymer concentration of the film when transported to the second wet tank is 80% by weight or more.
(4) The polymer concentration of the film when transported from the final wet bath to the heating step is 96% by weight or more.