JP2011140187A - Laminated film, transparent conductive laminated film, and electronic component - Google Patents

Abstract

The present invention provides a laminated film having high gas barrier properties, small dimensional change and warping due to temperature and humidity, and good optical properties as a display substrate such as transparency and low birefringence.
SOLUTION: On both surfaces of an inorganic glass film having a thickness of 5 μm to 200 μm, an adhesive layer made of a polymer having a thickness of 0.01 μm to 1 μm and a protection made of a heat resistant organic polymer having a thickness of 5 μm to 200 μm. It is a laminated film having a symmetrical structure in the thickness direction in which layers are sequentially applied and formed,
The ratio of the thickness of the inorganic glass film to the total thickness of the protective layer is 0.20 to 10, the total light transmittance of the laminated film is 85% or more, the haze is 1% or less, and the in-plane at a wavelength of 550 nm of the laminated film The phase difference (R) is 0 to 5 nm, and the thickness direction retardation (R _th ) at a wavelength of 550 nm is 0 nm to 50 nm.
A laminated film suitable as a substrate for electronic components.
[Selection] Figure 1

Description

  The present invention relates to a laminated film formed by laminating an organic polymer as a protective layer on an inorganic glass film. Specifically, the present invention relates to a laminated film having high gas barrier properties, small dimensional change and warping due to temperature and humidity, and good optical properties such as transparency and low birefringence. Moreover, this invention relates to the transparent conductive laminated film and electronic component which used such a laminated film as the base material.

  Movement to replace plastics that used glass as a base material for display substrates such as liquid crystal displays and organic EL (electroluminescence) displays, organic EL lighting substrates, and transparent conductive substrates for thin-film solar cells. Is thriving. This is because plastics are superior to glass in terms of weight reduction and flexibility, not only satisfying requirements such as portability and design freedom, but also not possible with rigid glass substrates, Roll to This is because a significant cost reduction due to the manufacturing process using Roll can be expected.

  As such a plastic substrate, a substrate made of polyethylene terephthalate, polycarbonate, polyolefin, or polyethersulfone has been proposed (see, for example, Patent Document 1).

  However, a substrate made of plastic has several problems compared to a substrate made of glass. First, a plastic substrate has a problem that heat resistance is low. Therefore, heat resistance is required such as TFT (thin film transistor) formation on the substrate, formation of a transparent conductive layer having a low resistance value, or sealing with an insulating material. There is a problem in dealing with the substrate formation process. In addition, the plastic substrate generally has a smaller gas barrier property than a glass substrate that hardly transmits gas molecules, and it is necessary to prevent deterioration of the light-emitting element due to water or oxygen. This is a problem when applied to a display substrate in which an organic semiconductor that is considered to be vulnerable to oxygen is used in the substrate. Similarly, when applying thin film silicon or organic semiconductor solar cell substrates that need to prevent degradation of photoelectric conversion materials, plastic substrates with low gas barrier properties have a lifetime due to the passing water and oxygen. A decrease occurs. Furthermore, compared to glass, silicon, and wiring forming materials (silver, copper, aluminum, etc.), plastics usually have a higher coefficient of linear expansion, thermal shrinkage, and hygroscopic expansion, and the dimensional change due to heat and humidity is large. In addition, problems such as warpage of the substrate after formation, disconnection of wiring, displacement of pixel dots, and the like may occur.

  As a method for simultaneously solving these problems, a method of combining a glass film and a resin has been proposed (Patent Documents 2 to 11). This can be expected as the gas barrier property and low linear expansion coefficient of glass and the flexibility of resin.

  However, there is a problem that cannot be further solved when actually used as a display substrate. For example, Patent Documents 2 to 6 propose a laminated film in which a glass film and a plastic film are bonded. However, the plastic film is prone to birefringence, which causes the display quality of the display to deteriorate during its manufacture, and birefringence or mechanical strain due to the strain caused by the crimping stress that occurs during bonding to the glass film. There is a problem such as the destruction of the glass film. Moreover, the thing which bonded the plastic film only to the single side | surface of the glass film has the problem that a film will warp by temperature and humidity from the difference in the thermal expansion coefficient and hygroscopic expansion coefficient of glass and resin.

  On the other hand, Patent Document 7 proposes a laminate in which the difference in linear expansion coefficient between glass and resin is reduced by applying a resin containing a filler to a glass film, thereby reducing the occurrence of film warpage due to temperature. Has been. However, as in Patent Document 3, it is difficult for this technique to prevent a decrease in transparency due to light scattering at the interface between the resin and the filler. Further, since it is difficult to match the linear expansion coefficients completely, it is impossible to completely suppress the warpage. Therefore, it is not suitable for actual use as a substrate.

  Patent Documents 8 and 9 propose a laminate having a structure in which a resin is sandwiched between two thin glass films. In this case, since the glass film is the outermost surface, it has the disadvantage that the film itself is easily broken by contact impact with the object, and at the same time, a laminated body with a structure in which both surfaces are sandwiched between glasses having a higher elastic modulus than the resin It becomes a thing with high rigidity, and cannot be said to be a preferable form from a viewpoint of a softness | flexibility.

Patent Documents 10 and 11 show a laminate method in which a resin layer is directly applied to at least one of glass films. Here, the resin layer may be one side of a glass film, but if only one side is applied, depending on the shrinkage when applying the resin layer, the difference between the thermal expansion coefficient, the water absorption rate, and the thermal shrinkage rate between the glass and the resin Since the laminated film is warped, it could not be used practically.
Moreover, when the thickness of the resin layer was not sufficiently thick with respect to the thickness of the glass, it was difficult to say that the laminated film had sufficient strength against impact.

  Furthermore, when a resin used as a polymer layer has a small dimensional change due to heat or water absorption and has high heat resistance, such resin usually has poor adhesion to glass and is directly applied to a glass film. In some cases, it easily peels off and is not suitable for use. This cannot be easily improved even if the glass film surface is subjected to a surface treatment such as a corona treatment. On the other hand, if a resin with good adhesion to glass is selected, it will have high water absorption or low heat resistance, and if these resins are applied directly on the glass film, thermal expansion and hygroscopic expansion of the glass and resin will occur. Due to the difference in thickness, warpage of the laminated film, generation of birefringence due to generation of stress between layers, breakage of glass, and the like occurred, and there was a problem that it was not suitable for practical use.

JP 2004-330507 A Japanese Patent Laid-Open No. 2001-113631 JP 2002-299041 A JP 2008-273211 A JP 2007-010834 A JP-A-4-235527 JP 2007-203473 A Japanese Patent Laid-Open No. 7-043696 JP 2008-037094 A Special Table 2002-534305 gazette Special Table 2002-542971

  An object of the present invention is to provide a laminated film having high optical barrier properties, small dimensional change and warping due to temperature and humidity, and good optical characteristics as a display substrate such as transparency and low birefringence. Moreover, the objective of this invention is providing the transparent conductive laminated film and electronic component which consist of such a laminated film.

  As a result of intensive studies to solve the above problems, the inventor has a symmetrical structure in the thickness direction of an adhesive layer made of a polymer on both sides with a glass film as a core and a protective layer made of a heat-resistant organic polymer. As described above, the inventors have found that the above-described problems can be achieved by the laminated film sequentially formed by coating, and have reached the present invention described below.

1. A laminated film in which an adhesive layer made of a polymer and a protective layer made of a heat-resistant organic polymer are sequentially coated on both surfaces of an inorganic glass film, and the following (1) to (7)
(1) The laminated film has a symmetrical structure in the thickness direction (2) The thickness of the inorganic glass film is 5 μm to 200 μm
(3) The thickness of the adhesive layer is 0.01 μm to 1 μm
(4) The thickness of one side of the protective layer is 5 μm to 200 μm
(5) The ratio of the thickness of the inorganic glass film and the total thickness of the protective layer is
0.20 ≦ Inorganic glass film thickness (μm) / Total thickness of protective layer (μm) ≦ 10
(6) The total light transmittance of the laminated film is 85% or more and the haze is 1% or less. (7) The in-plane retardation (R) at a wavelength of 550 nm of the laminated film is 0 to 5 nm and the thickness at a wavelength of 550 nm. direction of the phase difference _{(R th)} is 0nm~50nm
_{[R th} is _R th of the optical film at a wavelength of _{550nm = | (n x + n} y) / 2-n x | in × d _{(wherein, n x, n y, n} z are each of three-dimensional refractive index of the optical film It is a refractive index in the x-axis, y-axis, and z-axis directions, and d is a value calculated by the film thickness (nm). ]
And a laminated film suitable as a substrate for electronic components.
2. The ratio of the thickness of the inorganic glass film to the total thickness of the protective layer (total of both surfaces) is 0.50 ≦ the thickness of the inorganic glass film (μm) / the total thickness of the protective layer (μm) ≦ 2. The laminated film according to 1, which is 0.
3. The laminated film according to 1 or 2, wherein the heat-resistant organic polymer is a thermoplastic resin having a glass transition temperature of 200 ° C or higher, or a thermosetting resin.
4). The laminated film according to any one of claims 1 to 3, wherein an absolute value of a photoelastic coefficient of the heat-resistant organic polymer at a wavelength of 550 nm is 80 x 10 ^-12 Pa ^-1 or less. The laminated film according to any one of 1 to 4, wherein the heat-resistant organic polymer has a water absorption rate of 1.0% or less.
6). The laminated film according to any one of 1 to 5, wherein the heat-resistant organic polymer has an average linear expansion coefficient in the range of 50 ° C to 150 ° C of 0 to 100 ppm / ° C.
7). The heat-resistant organic polymer is mainly composed of any one selected from the group consisting of polycarbonate, polyester, polyimide, polyetherimide, polyarylate, polysulfone, polyethersulfone, amorphous polyolefin, acrylic resin, and epoxy resin. The laminated film according to any one of 1 to 6.
8). The laminated film according to any one of 1 to 7, wherein the adhesion between the inorganic glass film and the protective layer is 80% or more in terms of the number of grids not peeled in the grid test / the number of all grids.
The laminated | multilayer film with a hard coat which distribute | arranged the hard-coat layer further to the single side | surface or both surfaces of the laminated | multilayer film in any one of 9.1-8.
10. A transparent conductive laminated film, wherein a transparent conductive layer is further arranged on one or both sides of the laminated film according to any one of 10.1 to 8 or the laminated film with a hard coat according to 9.
11. An electronic component using the transparent conductive laminated film according to 11.10.

  According to the present invention, a laminated film having high heat resistance, high gas barrier properties, small dimensional change and warping due to temperature and humidity, and good optical properties is provided. Moreover, according to this invention, the transparent conductive laminated film which consists of such a transparent laminated film is provided.

  More specifically, according to the laminated film of the present invention and the transparent conductive laminated film comprising the same, the substrate of the flexible display has high transparency, high heat resistance, and low linear expansion coefficient in the surface direction. When used as a substrate, it is possible to cope with a substrate formation process that requires heat resistance such as TFT formation, and problems such as substrate warpage, wiring disconnection, and pixel dot misalignment after substrate formation are unlikely to occur. Moreover, according to the transparent laminated film of the present invention and the transparent conductive laminated film comprising the same, since it has the gas barrier properties and dimensional stability inherent to glass, it can be used for organic EL displays, organic EL lighting, liquid crystal displays, solar When used as a substrate for a battery or the like, high durability can be imparted.

It is a figure for demonstrating the layer structure of the laminated | multilayer film of this invention. It is a figure for demonstrating the layer structure of the laminated | multilayer film with a hard coat of this invention. It is a figure for demonstrating the layer structure of the transparent conductive laminated film of this invention.

The present invention will be described below.
<Laminated film-layer structure>
The laminated film of the present invention is a laminated film in which a protective layer made of a heat-resistant organic polymer is formed on both sides of an inorganic glass film with a symmetrical structure in the thickness direction via an adhesive layer made of a polymer. As shown in FIG. 1, all aspects of the laminated film of the present invention are laminated films 10 in which an adhesive layer 12 is formed on both surfaces of an inorganic glass film 11 and a heat-resistant protective layer 13 is further formed.

In the laminated film of the present invention, the “symmetrical structure” means that the adhesive layer and the protective layer formed on both sides of the inorganic glass film have the same composition on both sides, and the thickness of the protective layer is almost the same on the front and back sides. Thickness is said. Here, substantially the same thickness is the ratio A between the thickness of the protective layer formed on one side of the inorganic glass film (referred to as A) and the thickness of the protective layer formed on the opposite side (referred to as B) A / B is 0.7 or more and 1.5 or less. A / B is preferably 0.8 or more and 1.3 or less, more preferably 0.9 or more and 1.1 or less.
From the viewpoint of adhesion, the ratio C / B between the thickness of the adhesive layer (C) and the thickness of the protective layer (B) is preferably 0.002 or more and 0.01 or less.

  The thickness of the laminated film of the present invention is preferably 30 μm to 500 μm, more preferably 50 μm to 200 μm, from the viewpoints of handling and ease of manufacture, flexibility, and strength. In addition, since the thickness of the front and back of the adhesive layer is much thinner than the thickness of the protective layer, the ratio of the thickness is not particularly limited.

<Inorganic glass film>
Examples of the component of the inorganic glass film in the present invention include borosilicate glass, alkali-free glass, low alkali glass, soda lime glass, sol-gel glass, and the like.

  Examples of the inorganic glass film in the present invention include those containing the above glass as a main component, and those obtained by subjecting glass to surface treatment. Among these, inexpensive soda lime glass coated with an alkali seal, alkali-free glass, and the like are preferable.

  The thickness of the inorganic glass film of the present invention is 5 μm to 200 μm, more preferably 10 μm to 100 μm, and particularly preferably 20 to 80 μm. If the thickness is less than 5 μm, the production becomes difficult, which is not preferable. On the other hand, if the thickness of the glass exceeds 200 μm, the repulsive force against stress such as bending is large, and flexibility is lost.

  In a display substrate on which application of the laminated film of the present invention is assumed, particularly in an organic EL display, high smoothness such as 1 nm or less is required as the surface roughness Ra. In the laminated film of the present invention, since the glass film also forms the adhesive layer and the protective layer on both sides, the smoothness of the glass film does not need to be extremely high, but if the unevenness is too large, the unevenness is also caused by the adhesive layer or the protective layer. Since it cannot cover, it is not preferable.

  Further, the inorganic glass film of the present invention may be prepared by polishing the surface thereof, but the labor and cost of polishing work increase, and scratches on the glass surface caused by polishing reduce the strength. Polishing is preferred. In order to manufacture a thin glass plate having a non-polished surface in large quantities and at low cost, it is suitable to form the glass plate by an overflow method, a slot down method, a redraw method, or the like. Among these, the overflow method is preferable because it is a production method suitable for forming an extremely smooth glass surface without polishing.

<Inorganic glass film-pretreatment>
The inorganic glass film of the present invention may be pretreated for the purpose of ensuring adhesion with a heat-resistant protective layer or an adhesive layer. The pretreatment here refers to corona treatment, plasma treatment, UV treatment, UV ozone treatment, alkali treatment and the like. These may be performed by combining a plurality of pretreatments.

<Adhesive layer>
In the laminated film of the present invention, an adhesive layer is disposed between the inorganic glass film and the protective layer for the purpose of improving adhesion. The term “adhesive layer” as used herein refers to a layer mainly composed of a polymer capable of ensuring adhesion between both the inorganic glass film and the protective layer. As will be described later, the protective layer in the present invention is an organic polymer having high heat resistance. However, an organic polymer having such characteristics is generally difficult to ensure adhesion with glass. In this case, it is necessary to ensure adhesion by providing an adhesive layer between the inorganic glass film and the protective layer.

  The polymer that forms such an adhesive layer is not particularly limited as long as the adhesion between the inorganic glass film and the protective layer is ensured, and a preferable adhesive layer is selected depending on the protective layer to be selected. However, for example, a siloxane-containing thermoplastic resin having good adhesion to both inorganic glass and organic polymer, and an organosiloxane thermosetting resin are preferable.

  Examples of siloxane-containing thermoplastic resins include polycarbonate, polyester, polyetherimide, polyarylate, polysulfone, polyethersulfone, amorphous polyolefin, and monomers having siloxane bonds that contain siloxane bonds in the terminal, side chain, or main chain. An acrylic resin, an epoxy resin, a urethane resin, or the like formed by mixing a single monomer or another monomer.

Examples of the method for forming the adhesive layer of the present invention include the following (a) to (b) adhesive layer forming methods.
(A) A polymer precursor is applied as a monomer or oligomer on an inorganic glass film, and after application, a polymerization reaction is performed by active energy rays or thermal energy to finally form an adhesive layer.
(B) The adhesive layer is formed by dissolving the polymer in a solvent that dissolves the polymer, coating the solution on the inorganic glass film, and then drying and removing the solvent.

Among these, the method (a) is preferable because it is easy to process after coating, or is hardened once, so that dissolution does not easily occur when a further protective layer is applied.
In such an adhesive layer, examples of the polymer that forms the adhesive layer by the polymer forming method (a) include active energy ray-curable resins and thermosetting resins mainly containing Si.

  Examples of monomers that provide an active energy ray-curable resin containing Si include methylacryloxypropyltrimethoxysilane, tris (trimethylsiloxy) silylpropyl methacrylate, allyltrimethylsilane, diallyldiphenylsilane, methylphenylvinylsilane, methyltriallylsilane, Phenyltriallylsilane, tetraallylsilane, tetravinylsilane, triallylsilane, triethylvinylsilane, vinyltrimethylsilane, 1,3-dimethyl-1,1,3,3-tetravinyldisiloxane, divinyltetramethyldisiloxane, vinyltris (trimethylsiloxy) Silane, vinylmethylbis (trimethylsilyloxy) silane, N- (trimethylsilyl) allylamine, polydimethyl having double bonds at both ends Siloxanes, and silicone-containing acrylate.

  In addition, when superposing | polymerizing a resin layer by an active energy ray, generally an appropriate amount of a photoinitiator may be added and an appropriate amount of a photosensitizer may be added if necessary. Examples of the photopolymerization initiator include acetophenone, benzophenone, benzoin, benzoylbenzoate, and thioxanthone. Examples of the photosensitizer include triethylamine and tri-n-butylphosphine.

  Examples of thermosetting resins include organosilane thermosetting resins such as alkoxysilane compounds, alkoxytitanium thermosetting resins, melamine thermosetting resins using etherified methylol melamine, and the like as monomers. Examples thereof include thermosetting resins, phenol-based thermosetting resins, and epoxy curable resins. These thermosetting resins can be used alone or in combination. If necessary, a thermoplastic resin can be mixed with the thermosetting resin.

  Examples of organosilane thermosetting resins include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4, epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxy Propylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-amino Ethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N- (1,3- Dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3 -Chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane, tetramethoxysilane, tetraethoxy Silane, methyl trimethoxy silane, methyl triethoxy silane, dimethyl diethoxy silane, phenyl triethoxy silane, hexamethyldisilazane, hexyltrimethoxysilane, be used decyltrimethoxysilane or the like. Among them, from the viewpoint of stabilizing the adhesion to the substrate, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, N-2, which exhibit stable performance (Aminoethyl) 3-aminopropyltrimethoxysilane is preferably used alone or in combination. As a preferable mixing ratio of the organosiloxane thermosetting resin, for example, 3-glycidoxypropyltrimethoxysilane, methyltrimethoxysilane, and N- (2-aminoethyl) -3-aminopropyltrimethoxysilane are in a weight ratio. And mixing at 4: 2: 1.

In the present invention, the polymer forming the adhesive layer may be a blend of a plurality of polymers as long as it satisfies the characteristics of the final laminated film.
Further, the adhesive layer forming method may be performed by combining a plurality of methods. For example, a method in which the above (a) and (b) are combined, that is, a polymer precursor, that is, a monomer or an oligomer, is dissolved in a solvent in which they are dissolved and coated on an inorganic glass film. In addition to drying and removing, a polymerization reaction may be performed by active energy rays or thermal energy to finally form an adhesive layer.

  The adhesive layer in the present invention has a thickness of 0.01 μm to 1 μm. Preferably it is 0.02 micrometer-0.5 micrometer, Most preferably, it is 0.02 micrometer-0.3 micrometer. An adhesive layer that is too thin is not preferable because it is not sufficient to improve the adhesion between the inorganic glass film and the protective layer. On the other hand, when the adhesive layer is too thick, the heat resistance and mechanical strength of the adhesive layer affect the properties of the laminated film, thereby reducing the adhesion and heat resistance or causing warping.

<Protective layer>
The protective layer in the present invention is a layer mainly composed of an organic polymer having high transparency and heat resistance, little occurrence of birefringence during layer formation, and heat resistance obtained by polymerizing organic molecules. Here, the thickness of one side of the protective layer formed on the inorganic glass film is 5 μm to 200 μm, preferably 8 μm to 100 μm, and particularly preferably 10 μm to 50 μm. If the thickness of one side of the protective layer is too small, it is not preferable because it is difficult to sufficiently fulfill the role of protecting the inorganic glass. On the other hand, if the thickness of one side of the protective layer is too large, the laminated film cannot give sufficient flexibility, and the retardation of the laminated film depends greatly on the thickness of the protective layer, and the retardation is Since it will become large, it is not preferable.

<Laminated film-layer thickness ratio>
In the laminated film of the present invention, when the ratio of the thickness of the inorganic glass film and the total thickness of the protective layer (the thickness of the inorganic glass film / the total thickness of the protective layer) is D, 0.20 ≦ D ≦ 10 It is a range. Preferably, it is in the range of 0.50 ≦ D ≦ 2.0, and particularly preferably in the range of 0.70 ≦ D ≦ 1.5. If D is too small, shrinkage when forming a protective layer made of a heat-resistant organic polymer, and dimensional changes due to expansion and shrinkage due to environmental changes such as temperature and humidity will be large. The film may break. On the other hand, when D is too large, the thickness of the protective layer is insufficient, and the inorganic glass film is easily broken by impact.

<Heat resistant organic polymer-Glass transition temperature>
The heat-resistant organic polymer in the present invention refers to an organic polymer having a high glass transition temperature. The heat-resistant organic polymer in the present invention preferably has a glass transition temperature of 200 ° C. or higher, or high heat resistance such as a curable resin or a crosslinkable resin. More preferably, the glass transition temperature is more preferably 230 ° C. or higher. The glass transition temperature is particularly preferably 250 ° C. or higher. In addition, polyimide or a resin having a high degree of crosslinking does not show a clear Tg, but these resins can also be suitably used. When the glass transition temperature is low, the heat resistance of the laminated film is not sufficient, and for example, it is difficult to adapt to a high temperature process such as TFT formation on a display substrate.

  In the present invention, the glass transition temperature is measured using a differential scanning calorimeter (DSC) at a heating rate of 20 ° C./min, and the inflection point of the temperature-differential heat curve is evaluated as the glass transition temperature. To do.

<Heat resistant organic polymer-Photoelastic coefficient>
The heat-resistant organic polymer in the present invention preferably has an absolute value of a photoelastic coefficient measured at a wavelength of 550 nm of 80 × 10 ⁻¹² Pa ⁻¹ or less. The absolute value is more preferably not less 50 × ¹⁰ -12 ^{Pa -1} or less in photoelastic coefficient measured at a wavelength of 550 nm, and particularly preferably 50 × ¹⁰ -12 ^{Pa -1} or less.

Here, the photoelastic coefficient C is defined by the following formula, and when the elastic body receives an external force, it temporarily becomes an optical anisotropic body to cause birefringence, and after the external force is removed, it returns to the original. This is a constant representing the stress dependence of the difference in refractive index between the stress direction and the vertical direction in a substance exhibiting a photoelastic effect. That is, the relationship between the refractive index difference (Δn) and the photoelastic coefficient C is expressed by the following equation.
Δn = C · σ
Δn: difference in refractive index (difference in refractive index between the stress direction and the vertical direction)
C: Photoelastic coefficient (Pa ⁻¹ )
σ: Stress (Pa)

  The resin having a positive photoelastic coefficient is a resin having a positive sign of the photoelastic coefficient, and the resin having a negative photoelastic coefficient is a resin having a negative sign of the photoelastic coefficient. Therefore, as described above, when stress is applied to the orientation x in the XY plane, nx> ny when the photoelastic coefficient is positive, and ny> nx when negative.

  When the absolute value of the photoelastic coefficient is high, birefringence occurs due to the internal stress of the protective layer caused by the formation of the protective layer, bending of the laminated film, or changes in temperature and humidity. In some cases, the quality is deteriorated, which is not preferable. In particular, when used in combination with a polarizing plate in a liquid crystal display or an organic EL display, it may be unfavorable because display quality such as light loss on the screen and viewing angle dependence of image quality may occur.

<Heat resistant organic polymer-water absorption>
The heat-resistant organic polymer in the present invention preferably has a water absorption rate of 1.0% or less. Preferably it is 0.7% or less, More preferably, it is 0.5% or less. Those having a high water absorption rate cause volume expansion and contraction due to humidity, and may cause delamination or glass film breakage due to warpage of the laminate or generation of stress with the inorganic glass layer.
In the present invention, the water absorption is measured using a film sample having a 50 mm square and a thickness of 100 μm, and is evaluated by a method defined in accordance with JIS K7209.

<Heat resistant organic polymer-linear expansion coefficient>
The heat-resistant organic polymer in the present invention preferably has a linear expansion coefficient at 50 to 150 ° C. of 0 to 100 ppm / ° C. More preferably, it is 0-80 ppm / degreeC, Most preferably, it is 0-50 ppm / degreeC. When the linear expansion coefficient is high, volume expansion / contraction occurs depending on temperature, which may cause peeling of the laminate due to warpage of the laminated body or generation of stress with the inorganic glass layer, or breakage of the glass film.
In the present invention, the linear expansion coefficient is measured using a sample of an unstretched film having a thickness of 100 μm.

<Heat resistant organic polymer-component>
The heat-resistant organic polymer in the present invention is preferably mainly composed of polycarbonate, polyester, polyimide, polyetherimide, polyarylate, polysulfone, polyethersulfone, amorphous polyolefin, acrylic resin, or epoxy resin.

  Among these, polycarbonate is preferable because it has transparency, heat resistance, and mechanical strength. In particular, a heat-resistant polycarbonate having a glass transition temperature increased by changing a monomer from a polycarbonate having a general 2,2-bis (4-hydroxyphenyl) propane (so-called bisphenol-A) as a monomer is transparent and mechanical. It is preferable because it has high heat resistance in addition to strength. In addition, about a heat resistant polycarbonate, it can obtain by the method as described in Unexamined-Japanese-Patent No. 06-25398, Unexamined-Japanese-Patent No. 2001-139676, etc., for example.

［式中Ｒ₁ 〜Ｒ₄ は水素原子、ハロゲン原子、フェニル基、炭素数１〜３のアルキル基であって、同一又は異なっていてもよい。］で表される構成単位及び下記一般式［２］

［式中Ｗは単結合、アルキリデン基、シクロアルキリデン基、フェニル基置換アルキリデン基、スルホン基、スルフィド基又はオキシド基であり、Ｒ₅ 及びＲ₆は水素原子、ハロゲン原子、フェニル基、炭素数１〜３のアルキル基であって、同一又は異なっていてもよく、ｍ及びｎは夫々１〜４の整数である。］で表される構成単位からなるポリカーボネートを挙げることができる。 As heat-resistant polycarbonate, for example, the following general formula [1]

[Wherein R _{1 to} R ₄ are a hydrogen atom, a halogen atom, a phenyl group, or an alkyl group having 1 to 3 carbon atoms, which may be the same or different. ] And the following general formula [2]

[W is a single bond, an alkylidene group, a cycloalkylidene group, a phenyl group-substituted alkylidene group, a sulfone group, a sulfide group, or an oxide group, and R ₅ and R ₆ are a hydrogen atom, a halogen atom, a phenyl group, and a carbon number of 1 -3 alkyl groups, which may be the same or different, and m and n are each an integer of 1-4. The polycarbonate which consists of a structural unit represented by this can be mentioned.

  An acrylic resin is also preferably used for the heat-resistant organic polymer in the present invention. This acrylic resin can be formed of a thermosetting resin or an active energy ray curable resin. Especially, the hardening method by ultraviolet curing which used the ultraviolet-ray for the active energy ray is excellent in productivity and economical efficiency, and is suitable.

  Examples of such ultraviolet curable acrylic resins include 1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, and tripropylene glycol diacrylate. Acrylate, neopentyl glycol diacrylate, 1,4-butanediol dimethacrylate, poly (butanediol) diacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, triethylene glycol diacrylate, triisopropylene glycol Diacrylates such as diacrylate, polyethylene glycol diacrylate and bisphenol A dimethacrylate; Triacrylates such as allylpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol monohydroxytriacrylate and trimethylolpropane triethoxytriacrylate; tetraacrylates such as pentaerythritol tetraacrylate and di-trimethylolpropane tetraacrylate; And pentaacrylates such as dipentaerythritol (monohydroxy) pentaacrylate. In addition to this, as the ultraviolet curable acrylic resin as the heat-resistant organic polymer, a polyfunctional acrylate having five or more functions can also be used. These polyfunctional acrylates may be used alone or in combination of two or more. Further, these acrylates are used by adding one or more of third components such as photoinitiators, photosensitizers, leveling agents, fine particles composed of metal oxides and acrylic components, and ultrafine particles. be able to.

<Protective layer-forming method>
The organic polymer that forms the protective layer of the present invention is an organic polymer that can form a protective layer on the inorganic glass film on which the adhesive layer is formed and satisfies the characteristics as a laminated film. The method for forming the molecule and the protective layer is not particularly limited, and examples thereof include organic polymer and protective layer forming methods such as (c) to (e) below.

(C) An organic polymer precursor, that is, a monomer or oligomer is applied onto an inorganic glass film, and after the application, a polymerization reaction is performed by active energy rays or thermal energy to finally form a protective layer.
(D) A thermoplastic heat-resistant organic polymer is heated and melted, the melt is applied onto an inorganic glass film, and then cooled to form a protective layer.
(E) A heat-resistant organic polymer is dissolved in a solvent to be dissolved, the solution is applied onto an inorganic glass film, and then the solvent is dried and removed to form a protective layer.
In the present invention, the heat-resistant organic polymer that forms the protective layer may be a blend of a plurality of organic polymers as long as it satisfies the characteristics of the final laminated film.

  Further, the protective layer forming method may be performed by combining a plurality of methods. For example, a method of combining the above (c) and (d), that is, melt coating of an organic polymer precursor onto an inorganic glass film and a polymerization reaction may be performed simultaneously. Also, for example, a method in which the above (c) and (e) are combined, that is, an organic polymer precursor, that is, a monomer or an oligomer, is dissolved and applied to an inorganic glass film in a solvent in which they are dissolved. The solvent may be dried and removed later, and a polymerization reaction may be performed by active energy rays or heat energy to finally form a protective layer.

<Protective layer-additive>
In the protective layer in the present invention, various kinds of materials such as a heat stabilizer, a light stabilizer, and a hydrolysis inhibitor are used for the purpose of improving thermal stability and weather resistance within the range of maintaining the properties as a laminated film and a protective layer. Stabilizers may be added. A preferable agent and addition amount of these stabilizers are selected depending on the organic polymer to be used. These stabilizers may be used alone or in combination.

Further, the protective layer in the present invention is a color tone adjusting agent, a refractive index adjusting agent, an easy adjusting agent for the purpose of improving / adjusting the color tone, refractive index, and surface slipperiness within the range of maintaining the properties as a laminated film or a protective layer. Various additives such as a slipping agent may be added. These additives may be used alone or in combination.
Moreover, you may add a filler and a fiber to the protective layer in this invention in order to suppress a linear expansion coefficient and a water absorption rate in the range which maintains the characteristic as a laminated film or a protective layer.

<Layer application method>
The method for forming the protective layer and the adhesive layer is not particularly limited. For example, doctor knife, die coater, bar coater, gravure roll coater, curtain coater, knife coater, spin coater, lip coater, capillary coater, etc. Any known method such as a coating method, spray method, dipping method, or the like can be used. Among these, a die coater, a gravure roll coater, and a dipping method are preferable in consideration of the coating thickness and the ease of coating by Roll to Roll. Further, since the protective layer and the adhesive layer are often formed on only one side of the inorganic glass film at the time of layer formation, warping or curling due to shrinkage or the like often occurs, so it is preferable to apply both sides simultaneously.

  It is preferable that the adhesive layer and the protective layer in the present invention are continuously applied to the inorganic glass film and then wound up into a roll. In this case, an adhesive layer and a protective layer may be continuously formed on the produced inorganic glass film and then wound into a roll. Alternatively, the inorganic glass film wound up in a roll shape may be unwound to form an adhesive layer and a protective layer, and then wound up into a roll shape. At this time, after forming an adhesive layer on the adhesive inorganic glass film and winding it once in a roll shape, this film may be unwound again to form a protective layer, and a method of winding in a roll shape may be used, or a film is formed. An adhesive layer may be continuously formed on the inorganic glass film, and then a protective layer may be continuously applied and formed, and then wound into a roll.

  Among these coating methods, since the inorganic glass film is very easy to break alone, an adhesive layer is continuously formed on the inorganic glass film formed on the formed inorganic glass film, and then the protective layer is continuously formed. It is preferable to form by coating and then roll up into a roll. The adhesive layer and the protective layer may be applied and formed by roll to roll from an inorganic glass film wound up in a roll shape, or the inorganic glass film is formed, and then the adhesive layer and the protective layer are applied by a continuous process. -You may form.

<Laminated film-Warpage during lamination>
Since the laminated film of the present invention has a symmetrical structure in the thickness direction, even if distortion occurs between the inorganic glass film part and the heat-resistant organic polymer part due to expansion / contraction during the formation of the protective layer, the distortion Is very rarely reflected as the warp of the laminated film itself. On the other hand, in a laminated film that does not have a symmetric structure in the thickness direction, when distortion occurs between the inorganic glass film part and the organic polymer part due to expansion / contraction during the formation of the protective layer, one side of the laminated film and its side Since the magnitude | size of the distortion in an opposite surface differs, since a curvature will arise in a laminated film as a result, it is not preferable.

  In addition, the warp of the laminated film is, for example, that the prepared laminated film is cut into a square of 100 mm × 100 mm and placed on a flat plate, and the four corners of the laminated film are lifted due to changes in the environment such as temperature and humidity. It can be evaluated by measuring the average change in height. The preferable range at this time is 0-5 mm, More preferably, it is 0-1 mm.

<Laminated film-Warpage due to environmental changes>
Since the laminated film of the present invention has a symmetrical structure in the thickness direction, even if distortion occurs due to the difference in expansion / shrinkage ratio between the inorganic glass film and the protective layer due to temperature and humidity, the distortion of the laminated film itself Very little is reflected as warpage. On the other hand, in a laminated film that does not have a symmetric structure in the thickness direction, if distortion occurs due to the difference in expansion / contraction rate between the inorganic glass film and the protective layer due to temperature and humidity, Since the magnitude | size of distortion of this differs, since curvature will arise in a laminated | multilayer film as a result, it is not preferable.

  In addition, the warp of the laminated film is, for example, a sample film cut into a square of 100 mm × 100 mm is placed on a flat plate, and before and after 12 hours or more have passed in an environment of a temperature of 25 ° C. and a relative humidity of 50%. It can be evaluated by measuring the average amount of change in the height of the floats at the center and at the four corners. The preferable range at this time is 0-5 mm, More preferably, it is 0-1 mm.

<Laminated film-total light transmittance>
From the viewpoint of visibility, the laminated film of the present invention has a total light transmittance of 85% or more, more preferably 87% or more, and particularly preferably 88% or more.
In the present invention, the total light transmittance is measured according to JIS K7361-1. Specifically, the total light transmittance τ _t (%) is a value represented by the following equation.
τ _t = τ ₂ / τ ₁ × 100
(Τ ₁ : incident light τ ₂ : total light transmitted through the sample piece)

  The laminated film of the present invention can realize a laminated film having a high total light transmittance because the glass, the heat-resistant organic polymer as the protective layer, and the polymer as the adhesive layer have high transparency, respectively. .

<Laminated film-haze>
Similarly, from the viewpoint of visibility, the laminated film of the present invention has a haze (cloudiness) of 1% or less, more preferably 0.7% or less, and particularly preferably 0.5% or less.
In the present invention, haze is defined according to JIS K7136. Specifically, the haze is a value defined as the ratio of the diffuse transmittance τd to the total light transmittance τt, and more specifically can be obtained from the following equation:
Haze (%) = [(τ4 / τ2) −τ3 (τ2 / τ1)] × 100
τ1: incident light beam τ2: total light beam transmitted through the test piece τ3: light beam diffused by the device τ4: light beam diffused by the device and the test piece

  The laminated film of the present invention can realize a laminated film having a low haze because the glass, the heat-resistant organic polymer as the protective layer, and the polymer as the adhesive layer have high transparency.

<Laminated film-retardation>
In the laminated film of the present invention, the in-plane retardation (R) at a wavelength of 550 nm is 0 to 5 nm, preferably 0 to 3 nm, and particularly preferably 0 to 2 nm. Here, the phase difference R is defined by the following formula, and is a characteristic representing a phase delay of light transmitted in a direction perpendicular to the film:
_{R (nm) = (n x} -n y) × d
n _x: refractive index _{n y} in the slow axis (highest refractive index axis) of the film plane at a wavelength of 550 nm: the refractive index of the _{n x} and the vertical direction at a wavelength of 550 nm d: film thickness (nm)

The laminated film of the present invention is a retardation in a thickness direction at a wavelength of 550 nm _{(R th)} is 0Nm～50nm, preferably not more than 0nm~40nm, 0nm~30nm is particularly preferred. Here, the thickness direction retardation _Rth is defined by the following equation:
R _th = | (n _x + n _y ) / 2−n _z | × d
n _x: refractive index in a slow axis in the film plane at a wavelength of 550nm (highest refractive index axis) _{n y:} refractive index of _{n x} and the vertical direction at a wavelength of 550nm _{n z:} refractive index in the thickness direction at a wavelength of 550nm d: Film thickness (nm)

  In general, when a curing reaction is involved in forming a protective layer, the formed protective layer undergoes molecular orientation in the surface direction due to curing shrinkage, and when there is a difference between the temperature during curing and the temperature after cooling, the laminated film is protected. Residual stress occurs in both layers due to the difference in thermal expansion coefficient between the layer and the inorganic glass film. In addition, when forming a protective layer by applying a heated and melted organic polymer to an inorganic glass film and cooling it, the difference in temperature between the protective layer of the laminated film and the thermal expansion coefficient protective layer of the inorganic glass film is Due to thermal contraction, molecular orientation may occur in the surface direction, and at the same time, residual stress may occur in both due to the temperature during melt coating and the difference after cooling. In addition, when a protective layer is formed by applying an organic polymer dissolved in a solvent to an inorganic glass film and then removing the solvent by drying, the molecular orientation in the surface direction is reduced as the volume decreases during drying. Residual stress may occur at the same time due to the difference between the temperature during drying and the temperature after cooling, and the difference in the thermal expansion coefficient between the protective layer of the laminated film and the inorganic glass film. Due to molecular orientation and residual stress generated during the formation of these protective layers, an in-plane retardation or a thickness direction retardation may occur in the formed laminated film. Here, molecular orientation and residual stress often occur uniformly in any direction in the plane, and in this case, the in-plane phase difference cancels each other and is small. On the other hand, the retardation in the thickness direction tends to be larger than the in-plane retardation. In order to reduce the occurrence of phase difference, heat resistance should be applied to materials that are difficult to align in the plane, or that have a small retardation even when they are aligned, that is, those that have a small intrinsic birefringence, and those that have a small photoelastic coefficient. It is preferable to select the organic polymer. Moreover, the expression of the phase difference can also be suppressed by performing the drying and curing temperatures as close to room temperature as possible.

Note that the adhesive layer may cause a phase difference due to molecular orientation or residual stress as in the protective layer, but this is not a problem because the layer thickness is small.
When the absolute value of the in-plane retardation (R) or the thickness direction retardation (R _th ) is too large, the display quality is deteriorated when used as a display substrate. In particular, when used in combination with a polarizing plate in a liquid crystal display or an organic EL display, it is not preferable because the display quality deteriorates such as light loss on the screen and the viewing angle dependency of the image quality.

<Laminated film-Adhesiveness>
In the laminated film of the present invention, the adhesion between the inorganic glass film and the protective layer is preferably 80% or more, more preferably 90% or more, and 95% or more, as evaluated by a cross-cut peel test. It is particularly preferred. Here, the adhesion by the cross-cut peel test is measured by the following evaluation:

After a sample film is stuck and fixed to a stainless steel flat plate with a double-sided tape using an adhesive tape, 100 grids with an interval of 1 mm are formed on the laminated film with a cutter knife. Subsequently, a Nichiban adhesive tape (trade name “Cello Tape (registered trademark) No. 405”) was firmly pressure-bonded onto the grid with a fingertip, and peeled strongly vertically to leave a protective layer on the inorganic glass film. The degree is observed and the remaining number of the remaining 100 grids is evaluated as a percentage.
The laminated film of the present invention has an adhesive layer in order to enhance the adhesion between the protective layers of the inorganic glass and the heat-resistant organic polymer, and can obtain high adhesion.

<Laminated film-linear expansion coefficient>
In the laminated film of the present invention, since the inorganic glass film has a low linear expansion coefficient and a high tensile elastic modulus as compared with the protective layer, the linear expansion coefficient as the laminated film is also preferably a low linear expansion coefficient as a substrate for electronic components. have. The linear expansion coefficient of the laminated film in the present invention is preferably 0 to 20 ppm / ° C. More preferably, it is 0-15 ppm / degrees C, Most preferably, it is 0-10 ppm / degrees C. Here, the linear expansion coefficient is measured by the following evaluation:

  Using a heat / stress-strain measuring device, the temperature is increased at a rate of 5 ° C./min, and the average linear expansion coefficient in the temperature range of 50 ° C. to 150 ° C. is calculated. In addition, about the linear expansion coefficient of a protective layer, the unstretched organic polymer film about 100 micrometers thick is produced separately, and this is measured as a sample.

<Laminated film-impact resistance>
The laminated film in the present invention has a laminated structure in which an inorganic glass film having low impact resistance alone is protected with a protective layer, and has impact resistance preferable as a substrate for electronic components. Here, the impact resistance is evaluated by the following falling weight test: A test is performed using a test apparatus and a weight according to JIS K7211-1. Place a 50mm square sample on a flat 5mm thick SUS plate, fix the four sides with tape, drop the R2.5mm tip and 30g weight from the height of 10cm, and then look at the condition of the film sample to the microscope And evaluate the height at which the film was broken by collision. In addition, even if an iron ball is dropped from a height of 70 cm, “◯” is given for those in which no crack occurred in the film.

<Hard coat layer>
The laminated film of the present invention can further have a single or a plurality of hard coat layers within a range not losing the properties for the purpose of imparting the hardness and abrasion resistance of the laminated film surface depending on the application. This hard coat layer can be arranged on one or both sides of the laminated film of the present invention, but since the warp of the laminated film due to temperature and humidity does not occur, the same composition is formed on both sides with the same thickness. It is preferable to have.

  The hard coat layer can be formed of a thermosetting resin or an active energy ray curable resin. Among these, an ultraviolet curable resin using ultraviolet rays for active energy rays is preferable because it is excellent in productivity and economy.

  Examples of the ultraviolet curable resin for the hard coat layer include 1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, and tripropylene glycol. Diacrylate, neopentyl glycol diacrylate, 1,4-butanediol dimethacrylate, poly (butanediol) diacrylate, tetraethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, triethylene glycol diacrylate, triisopropylene Diacrylates such as glycol diacrylate, polyethylene glycol diacrylate and bisphenol A dimethacrylate; Triacrylates such as roll propane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol monohydroxytriacrylate and trimethylolpropane triethoxytriacrylate; tetraacrylates such as pentaerythritol tetraacrylate and di-trimethylolpropane tetraacrylate; and Mention may be made of pentaacrylates such as dipentaerythritol (monohydroxy) pentaacrylate. As the ultraviolet curable resin for the additional curable resin layer, a polyfunctional acrylate having 5 or more functional groups can also be used. These polyfunctional acrylates may be used alone or in combination of two or more. Further, these acrylates are used by adding one or more of third components such as photoinitiators, photosensitizers, leveling agents, fine particles composed of metal oxides and acrylic components, and ultrafine particles. be able to.

  In addition, when superposing | polymerizing a resin layer by an active energy ray, generally an appropriate amount of a photoinitiator may be added and an appropriate amount of a photosensitizer may be added if necessary. Examples of the photopolymerization initiator include acetophenone, benzophenone, benzoin, benzoylbenzoate, and thioxanthone. Examples of the photosensitizer include triethylamine and tri-n-butylphosphine.

  As the thermosetting resin for the hard coat layer, for example, an organosilane thermosetting resin such as an alkoxysilane compound, an alkoxytitanium thermosetting resin, an etherified methylol melamine or the like as a monomer is a melamine heat. Examples thereof include curable resins, isocyanate-based thermosetting resins, phenol-based thermosetting resins, and epoxy-curable resins. These thermosetting resins can be used alone or in combination. If necessary, a thermoplastic resin can be mixed with the thermosetting resin.

  In addition, when bridge | crosslinking a resin layer with a heat | fever, a reaction accelerator and / or a hardening | curing agent can be mix | blended in a proper quantity. Examples of the reaction accelerator include triethylenediamine, dibutyltin dilaurate, benzylmethylamine, pyridine and the like. Examples of the curing agent include methylhexahydrophthalic anhydride, 4,4′-diaminodiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, diaminodiphenylsulfone, and the like.

<Transparent conductive layer>
In the present invention, the transparent conductive layer is not particularly limited, and examples thereof include a crystalline metal layer or a crystalline metal compound layer. Examples of the component constituting the transparent conductive layer include metal oxide layers such as silicon oxide, aluminum oxide, titanium oxide, magnesium oxide, zinc oxide, indium oxide, and tin oxide. Of these, a crystalline layer mainly composed of indium oxide is preferable, and a layer made of crystalline ITO (Indium Tin Oxide) is particularly preferably used.

The transparent conductive layer can be formed by a known method. For example, a physical formation method (such as a DC magnetron sputtering method, an RF magnetron sputtering method, an ion plating method, a vacuum deposition method, a pulse laser deposition method) Physical Vapor Deposition (hereinafter referred to as “PVD”)) or the like can be used, but focusing on industrial productivity of forming a metal compound layer having a uniform film thickness over a large area, the DC magnetron sputtering method is desirable. In addition to the physical formation method (PVD), a chemical formation method such as a chemical vapor deposition method (hereinafter referred to as “CVD”) or a sol-gel method may be used. The sputtering method is desirable from the viewpoint of thickness control.
As the film thickness of the transparent conductive layer, an appropriate film thickness is selected from the required transparency and resistance values, but it is preferably 5 to 500 nm from the viewpoint of film stability and transparency.

  When the transparent conductive laminate of the present invention is used as a transparent electrode in a display element such as a liquid crystal display, an organic EL display, or electronic paper, a transparent electrode for organic EL lighting, or a transparent electrode of a thin film solar cell, It is preferable to use a transparent conductive layer having a surface resistance value of 1 to 50Ω / □ (Ω / sq), more preferably 1 to 30Ω / □ (Ω / sq).

<Other functional layers>
In addition to the hard coat layer and the transparent conductive layer, the laminated film of the present invention can be additionally provided with a functional layer as long as the characteristics of the laminated film or the laminated film with a hard coat or the transparent conductive laminated film are not impaired. . The functional layer referred to here is a layer intended to express some function chemically, optically, electrically, and physically, and is not particularly limited. For example, antireflection, antiglare properties, etc. And a layer capable of exhibiting functions such as light emission, polarization, light scattering, light collection, light refraction, antifouling property, chemical resistance, slipperiness, and insulation.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to such examples. In the examples, “parts” and “%” are based on weight unless otherwise specified. Various measurements in the examples were performed as follows.

<thickness>
The thickness of the inorganic glass film and the laminated film was measured with an electronic micro film thickness meter manufactured by Anritsu Corporation.
The thickness of the protective layer in the laminated film was measured by observing the cross section with a scanning electron microscope.
Regarding the thickness of the adhesive layer in the laminated film, optical simulation is performed by using the wavelength of the maximum peak or minimum peak of the reflectance expressed based on the light interference effect on the light reflection spectrum of the laminated surface and the value of the peak reflectance. Calculated by In addition, about the reflection spectrum, each spectrum was measured in the integrating sphere measurement mode of Hitachi spectrophotometer U3500. At this time, the incident angle of the measurement light to the sample was 5 degrees, a light shielding layer was formed on the back surface side, and the measurement was performed in a state where there was almost no reflection of the back surface of the sample and no light from the back surface side.

<Glass transition temperature (Tg)>
Using a laminated film as a measurement sample, using a thermal analysis system DSC-2910 manufactured by TA Instruments, in accordance with JISK7121, under a nitrogen atmosphere (nitrogen flow rate: 40 ml / min), temperature rising rate: 20 ° C./min Measured below.

<Haze>
According to JIS K7136, the haze of the laminated film was measured using a Nippon Denshoku Co., Ltd. haze meter (MDH2000).

<Total light transmittance>
The total light transmittance of the laminated film was measured according to JIS K7361-1 using a Nippon Denshoku Co., Ltd. haze meter (MDH2000).

<Phase difference R _e , R _th >
Using a spectroscopic ellipsometer M220 manufactured by JASCO Corporation, measurement was performed at a light wavelength of 550 nm. The in-plane retardation value _Re is measured in a state where the incident light beam is perpendicular to the film surface. The film thickness direction retardation value _Rth is obtained by changing the angle between the incident light beam and the film surface little by little, measuring the retardation value at each angle, and performing curve fitting with a known refractive index ellipsoid equation to obtain a three-dimensional the refractive indices _{n x,} n y, seek _{n z, R th = | (} n x + n y) / 2-n z | × d
Was obtained by substituting At that time, the average refractive index of the laminated film is required, but it was separately measured using an Abbe refractometer (trade name “Abbe refractometer 2-TERT” manufactured by Atago Co., Ltd.).

<Linear expansion coefficient>
The linear expansion coefficient of the laminated film and the protective layer was determined by placing a 4 mm wide × 30 mm sample at 25 ° C. and 50% RH for 24 hours, and then using a thermal / stress-strain measuring apparatus (SS6100 manufactured by SII Nanotechnology). The temperature was increased at a rate of 5 ° C./min, and the average linear expansion coefficient in the temperature range of 50 ° C. to 150 ° C. was calculated. The linear expansion coefficient of the protective layer was measured by separately preparing an unstretched organic polymer film having a thickness of about 100 μm and using this as a sample.

<Laminated film-Warpage during lamination>
A sample film cut into a square of 100 mm x 100 mm is placed on a flat plate, and after 12 hours or more in an environment of a temperature of 25 ° C and a relative humidity of 50%, the height of the floating of the four corners of the film is vernier caliper. Measured with

<Laminated film-Warpage due to environmental changes>
A sample film cut into a square of 100 mm x 100 mm is placed on a flat plate, and after 12 hours or more in an environment of a temperature of 25 ° C and a relative humidity of 50%, the height of the floating of the four corners of the film is vernier caliper. The average was taken as A (mm). Subsequently, this sample was put in a constant temperature and high humidity apparatus at a temperature of 60 ° C. and a relative humidity of 90% for 30 minutes, and then taken out into an environment of a temperature of 25 ° C. and a relative humidity of 50%, placed on a flat plate, The height of the float was measured with a caliper, and the average was defined as B (mm). The absolute value of the difference between A and B (B−A (mm)) is shown as warpage.

<Adhesion>
After a sample film was stuck and fixed to a stainless steel flat plate with a double-sided tape using a strong adhesive tape, 100 grids with a 1 mm interval were formed on the laminated film with a cutter knife. Subsequently, a Nichiban adhesive tape (trade name “Cello Tape (registered trademark) No. 405”) was firmly pressure-bonded onto the grid with a fingertip, and peeled strongly vertically to leave a protective layer on the inorganic glass film. The degree was observed and the remaining number of 100 grids was evaluated as a percentage.

<Photoelastic coefficient>
A sample having a width of 20 mm × 100 mm was placed at 25 ° C. and 50% RH for 24 hours, and then measured with a spectroscopic ellipsometer M220 manufactured by JASCO Corporation. It was calculated from the change in retardation value when stress was applied at a measurement wavelength of 550 nm.

<Water absorption>
A 50 mm square and 100 μm thick unstretched organic polymer film was separately prepared and used as a sample. Evaluation was made in accordance with JIS K7209.

<Impact resistance-falling ball test>
A 100 mm square sample was placed on a flat stainless steel plate having a thickness of 5 mm, and the four sides were fixed with tape. While changing the height by 10 cm, an iron ball having a diameter of 11 mm and a weight of 5.4 g was dropped from the sample and collided with the sample. The portion where the iron ball of the subsequent film sample collided was observed with a microscope, and the height at which the film was broken by the collision was evaluated. In addition, even if an iron ball was dropped from a height of 70 cm, a film that did not crack was marked as “◯”.

<Heat cycle test>
The prepared transparent conductive film is put in a thermo-hygrostat, and the following conditions (1) to (4) are repeated for up to 500 hours. Check whether the transparent conductive film after the test has cracks or not. And observed.
(1) 1 hour at a temperature of 25 ° C and 90% relative humidity (2) 5 hours at a temperature of 60 ° C and 90% relative humidity (3) 1 hour at a temperature of 25 ° C and 90% relative humidity (4) Temperature- 5 hours at 20 ° C and 0% relative humidity

[Example 1]
<Preparation of coating liquid A-1 for forming an adhesive layer>
After mixing 720 parts by weight of water, 1080 parts by weight of 2-propanol and 46 parts by weight of acetic acid, 480 parts by weight of 3-glycidoxypropyltrimethoxysilane (trade name “KBM403” manufactured by Shin-Etsu Chemical Co., Ltd.) and methyltrimethoxysilane (Product name “KBM13” manufactured by Shin-Etsu Chemical Co., Ltd.) 240 parts by weight and 120 parts by weight of N-2 (aminoethyl) 3-aminopropyltrimethoxysilane (trade name “KBM603” manufactured by Shin-Etsu Chemical Co., Ltd.) An alkoxysilane mixed solution is produced, this alkoxysilane mixed solution is stirred for 3 hours, hydrolyzed and partially condensed, and further 40000 parts by weight of a mixed solvent of 1: 1 weight ratio of isopropyl alcohol and 1-methoxy-2-propanol The coating liquid A-1 was prepared by diluting with

<Polymerization of heat-resistant polycarbonate>
Polymerization was carried out with reference to Example 1 of JP-A-2001-139676.
In a reactor equipped with a thermometer, a stirrer and a reflux condenser, 190500 parts of ion-exchanged water and 105400 parts of 25% aqueous sodium hydroxide solution were added, and 9,9-bis (4-hydroxy-3-methylphenyl) fluorene (hereinafter “bis”) was added. After dissolving 43560 parts of “cresol fluorene” (sometimes abbreviated as “cresol fluorene”), 11260 parts of 2,2-bis (4-hydroxyphenyl) propane (hereinafter sometimes abbreviated as “bisphenol A”) and 110 parts of hydrosulfite After adding 178400 parts of methylene chloride, 22810 parts of phosgene was blown in at 15 to 25 ° C. with stirring for 60 minutes. After completion of the phosgene blowing, a solution obtained by dissolving 222.2 parts of p-tert-butylphenol in 3300 parts of methylene chloride and 13200 parts of a 25% aqueous sodium hydroxide solution were added. After emulsification, 40 parts of triethylamine was added and the mixture was heated at 28 to 33 ° C. The reaction was terminated by stirring for a period of time. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and when the conductivity of the aqueous phase is almost the same as that of ion-exchanged water, the methylene chloride phase is concentrated and dehydrated to remove polycarbonate. A solution with a concentration of 20% was obtained. The polycarbonate obtained by removing the solvent from this solution had a molar ratio of biscresol fluorene to bisphenol A of 70:30 (polymer yield 97%). In addition, this polymer had an intrinsic viscosity of 0.685 and a Tg of 235 ° C.

<Preparation of coating liquid B-1 for forming a protective layer>
70 parts of methylene chloride was added to 30 parts of the polymerized heat-resistant polycarbonate and stirred until it was uniformly dissolved to prepare a coating solution B-1 having a 30% concentration of heat-resistant polycarbonate.

<Application by dipping method of adhesive layer>
A non-alkali glass inorganic glass film (trade name OA-10G) having a width of 200 mm, a length of 300 mm and a thickness of 50 μm, manufactured by the overflow method manufactured by Nippon Electric Glass Co., Ltd., in the coating liquid A-1. Then, the inorganic glass film was pulled up vertically at a pulling rate of 100 mm / min and heat-treated at 130 ° C. for 5 minutes to obtain a glass film having an adhesive layer formed on both sides of the inorganic glass film.

<Application of heat-resistant polycarbonate protective layer by dipping method>
Subsequently, the inorganic glass film on which the adhesive layer was formed was immersed in the coating liquid B-1, and then the inorganic glass film was pulled up vertically at a pulling rate of 100 mm / min and dried at 40 ° C. for 10 minutes. The film was dried at 120 ° C. for 10 minutes, and further dried at 200 ° C. for 60 minutes to prepare a laminated film in which a heat-resistant polycarbonate layer was formed on both surfaces of the inorganic glass film.
Table 1 shows the characteristics of the prepared laminated film.

[Example 2]
A laminated film was prepared in the same manner as in Example 1 except that the thickness of the inorganic glass film was changed to 30 μm as shown in Table 1.
Table 1 shows the characteristics of the prepared laminated film.

[Example 3]
A laminated film was prepared in the same manner as in Example 1 except that the thickness of the inorganic glass film was changed to 100 μm as shown in Table 1.
Table 1 shows the characteristics of the prepared laminated film.

[Example 4]
A laminated film was prepared in the same manner as in Example 1 except that the concentration of the heat-resistant polycarbonate in the coating liquid B-1 was 15%.
Table 1 shows the characteristics of the prepared laminated film.

[Example 5]
A laminated film was prepared in the same manner as in Example 1 except that the concentration of the heat-resistant polycarbonate in the coating liquid B-1 was 40%.
Table 1 shows the characteristics of the prepared laminated film.

[Example 6]
In the case of applying the heat-resistant polycarbonate layer by the dipping method, the inorganic glass film is not vertical but is pulled up so that the normal of the film surface is inclined by 10 ° from the horizontal. A heat-resistant polycarbonate layer was formed on both surfaces of the film, and a laminated film having slightly different heat-resistant polycarbonate layers on both surfaces was obtained.
Table 1 shows the characteristics of the prepared laminated film.

[Example 7]
In the formation of the adhesive layer, adhesive layers having different thicknesses were formed in the same manner as in Example 1 except that the dilution amount of the coating liquid A-1 with the mixed solvent was changed to 80000 parts by weight. Subsequently, a protective layer was formed in the same manner as in Example 1 to obtain a laminated film in which a heat-resistant polycarbonate layer was formed on both surfaces of the inorganic glass film.
Table 1 shows the characteristics of the prepared laminated film.

[Example 8]
In the formation of the adhesive layer, adhesive layers having different thicknesses were formed in the same manner as in Example 1 except that the amount diluted with the mixed solvent of the coating liquid A-1 was 20000 parts by weight. Subsequently, a protective layer was formed in the same manner as in Example 1 to obtain a laminated film in which a heat-resistant polycarbonate layer was formed on both surfaces of the inorganic glass film.
Table 1 shows the characteristics of the prepared laminated film.

[Example 9]
<Preparation of coating liquid A-2 for forming an adhesive layer>
After mixing 720 parts by weight of water, 1080 parts by weight of 2-propanol and 46 parts by weight of acetic acid, 840 parts by weight of 3-methacryloxypropyltrimethoxysilane (trade name “KBM503” manufactured by Shin-Etsu Chemical Co., Ltd.) is mixed to obtain alkoxysilane. A mixed solution is formed, and this alkoxysilane mixed solution is stirred for 2 hours to be hydrolyzed and partially condensed, and further diluted with a mixed solvent of isopropyl alcohol and 1-methoxy-2-propanol in a weight ratio of 1: 1 and coated. A working liquid A-2 was prepared.

<Application by dipping method of adhesive layer>
A non-alkali glass inorganic glass film having a width of 200 mm, a length of 300 mm, and a thickness of 50 μm manufactured by the overflow method manufactured by Nippon Electric Glass Co., Ltd. is immersed in the coating liquid A-2, and then the lifting speed is 100 mm. The inorganic glass film was pulled up vertically at / min and heat-treated at 130 ° C. for 5 minutes to obtain a glass film having an adhesive layer formed on both sides of the inorganic glass film.

<Application of heat-resistant polycarbonate protective layer by dipping method>
A non-alkali glass inorganic glass film (trade name: OA-10G) manufactured by Nippon Electric Glass Co., Ltd. overflow method having an adhesive layer formed by the above-described method, having a width of 200 mm, a length of 300 mm, and a thickness of 50 μm. ) In the coating liquid B-1, and then the inorganic glass film is pulled vertically at a pulling rate of 100 mm / min, dried at 40 ° C. for 10 minutes, then dried at 120 ° C. for 10 minutes, and further 200 Drying was carried out at 60 ° C. for 60 minutes to obtain a laminated film in which a heat-resistant polycarbonate layer was formed on both surfaces of the inorganic glass film.
Table 1 shows the characteristics of the prepared laminated film.

[Example 10]
<Preparation of coating liquid B-2 for forming the protective layer>
Add 70 parts of methylene chloride to 30 parts of Teijin Kasei's polycarbonate (grade name: C-1400, hereinafter abbreviated as “PC-A”) and stir until evenly dissolved. Coating liquid B-2 was prepared.

<Application by dipping method of adhesive layer>
A non-alkali glass inorganic glass film (trade name OA-10G) having a width of 200 mm, a length of 300 mm and a thickness of 50 μm, manufactured by the overflow method manufactured by Nippon Electric Glass Co., Ltd., in the coating liquid A-1. Then, the inorganic glass film was pulled up vertically at a pulling rate of 100 mm / min and heat-treated at 130 ° C. for 5 minutes to obtain a glass film having an adhesive layer formed on both sides of the inorganic glass film.

<Applying polycarbonate protective layer by dipping method>
Subsequently, the inorganic glass film on which the adhesive layer was formed was immersed in the coating liquid B-2, and then the inorganic glass film was pulled up vertically at a pulling rate of 100 mm / min and dried at 40 ° C. for 10 minutes. It dried at 120 degreeC for 60 minute (s), and the laminated | multilayer film in which the polycarbonate layer was formed on both surfaces of the inorganic glass film was obtained.
Table 1 shows the characteristics of the prepared laminated film.

[Example 11]
<Preparation of coating liquid B-3>
100 parts by weight of Aronix M405 manufactured by Toagosei Co., Ltd. as a tetrafunctional acrylate, and 5 parts by weight of Ciba Specialty Chemicals (Irgacure 184) as a photoinitiator are 1: 1 of isopropyl alcohol and 1-methoxy-2-propanol. It melt | dissolved in the mixed solvent and produced coating liquid B-3.

<Application of acrylic protective layer by dipping method>
A glass film formed with the same method as in Example 1 and having an adhesive layer formed was dipped in the coating liquid B-3, and then the inorganic glass film was pulled up vertically at a pulling rate of 100 mm / min. After drying for 2 minutes, ultraviolet rays with an integrated light quantity of 700 mJ / cm ² were irradiated with a high-pressure mercury lamp with a strength of 160 w to obtain a laminated film in which an acrylic layer was formed on both surfaces of the inorganic glass film.
Table 1 shows the characteristics of the prepared laminated film.

[Comparative Example 1]
As the inorganic glass film, a non-alkali glass inorganic glass film having a width of 200 mm, a length of 300 mm, and a thickness of 50 μm manufactured by an overflow method manufactured by Nippon Electric Glass Co., Ltd. is used to form a protective layer and an adhesive layer. The procedure was repeated as in Example 1 except that there was no. The evaluation results of this inorganic glass film are shown in Table 2.

[Comparative Example 2]
<Application by dipping method of adhesive layer>
A non-alkali glass inorganic glass film having a width of 200 mm, a length of 300 mm, and a thickness of 50 μm, manufactured by the overflow method manufactured by Nippon Electric Glass Co., Ltd., is immersed in the liquid A-1, and then the lifting speed is 100 mm / min. The inorganic glass film was pulled up vertically and heat treated at 130 ° C. for 5 minutes to obtain a glass film having an adhesive layer formed on both sides of the inorganic glass film.
Table 2 shows the characteristics of the glass film on which the adhesive layer was formed.

[Comparative Example 3]
<Application of heat-resistant polycarbonate protective layer by dipping method>
A non-alkali glass inorganic glass film (trade name OA-10G) 200 mm wide, 300 mm long and 50 μm thick manufactured by the overflow method manufactured by Nippon Electric Glass Co., Ltd. without forming an adhesive layer. Then, it is immersed in the coating liquid B-1, and then the inorganic glass film is pulled up vertically at a lifting speed of 100 mm / min, dried at 40 ° C. for 10 minutes, then dried at 120 ° C. for 10 minutes, and further to 200 ° C. And dried for 60 minutes to obtain a laminated film having a heat-resistant polycarbonate layer formed on both sides of the inorganic glass film.
Table 2 shows the characteristics of the prepared laminated film.

[Comparative Example 4]
<Die coat of heat-resistant polycarbonate layer>
A coating solution B having a heat-resistant polycarbonate concentration of 30% was coated on one side of an inorganic glass film having a width of 200 mm, a length of 300 mm, and a thickness of 50 μm, in the same manner as in Example 1, by a die coating method. After drying at 40 ° C. for 10 minutes, drying at 120 ° C. for 10 minutes, and further drying at 200 ° C. for 60 minutes, a laminated film having a heat-resistant polycarbonate layer formed on one side of the inorganic glass film was obtained. The thickness of the heat resistant polycarbonate layer was 20 μm. The produced laminated film was curled so that it was difficult to evaluate the warp with the heat-resistant polycarbonate layer inside when the film was dried and returned to room temperature.
Table 2 shows the characteristics of the prepared laminated film.

[Comparative Example 5]
A heat-resistant polycarbonate layer is formed on both surfaces of the inorganic glass film in the same manner as in Example 1 except that the coating liquid B-1 having a heat-resistant polycarbonate concentration of 5% is used as the protective layer coating liquid. A formed laminated film was obtained.
Table 2 shows the characteristics of the prepared laminated film.

[Comparative Example 6]
In the application of the heat-resistant polycarbonate layer by the dipping method, the inorganic glass film is not vertically but is tilted by 10 ° more than in Example 6 and pulled up obliquely. A laminated film having heat resistant polycarbonate layers formed on both sides was obtained.
Table 2 shows the characteristics of the prepared laminated film.

[Comparative Examples 7 and 8]
In the formation of the adhesive layer, adhesive layers having different thicknesses were formed in the same manner as in Example 1 except that the dilution amount of the coating liquid A-1 with the mixed solvent was changed. Subsequently, a protective layer was formed in the same manner as in Example 1 to obtain a laminated film in which a heat-resistant polycarbonate layer was formed on both surfaces of the inorganic glass film.
Table 2 shows the characteristics of the prepared laminated film.

[Comparative Example 9]
Coating liquid B-1 is cast on a mirror-finished stainless steel plate, then dried at 40 ° C. for 10 minutes, then dried at 120 ° C. for 10 minutes, further dried at 200 ° C. for 60 minutes, and a thickness of 100 μm. A heat-resistant polycarbonate film was prepared.
Table 2 shows the characteristics of the heat-resistant polycarbonate film.

[Comparative Example 10]
<Creation of heat-resistant polycarbonate film>
The coating liquid B-1 for forming the protective layer used in Example 1 was cast on a mirror-finished stainless steel substrate using a doctor knife, dried at 40 ° C. for 10 minutes, and subsequently heated at 100 ° C. for 60 minutes. The film was dried at 200 ° C. for 60 minutes to prepare a heat-resistant polycarbonate film having a thickness of 50 μm.

<Bonding with adhesive>
An acrylic adhesive with a film thickness of 15 μm was applied on one side of the inorganic glass film, and then the heat-resistant polycarbonate film prepared was bonded. Subsequently, an acrylic adhesive having a film thickness of 15 μm is similarly applied to the glass surface of the glass-film laminate, and then the heat-resistant polycarbonate film prepared is bonded, and the heat-resistant polycarbonate film is applied to both surfaces of the inorganic glass film. The laminated film which bonded was created.
Table 2 shows the characteristics of the prepared laminated film.

[Example 12]
<Preparation of coating liquid C-1>
1-methoxy-2-propanol was used as a diluent solvent in 59 parts by weight of bisphenoxyethanol full orange acrylate (manufactured by Osaka Gas Co., Ltd.) and 41 parts by weight of urethane acrylate (trade name “NK Oligo U-15HA” manufactured by Shin-Nakamura Chemical). Then, 3 parts by weight of Irgacure 184 (Ciba Geigy) was added as a photoinitiator and stirred until uniform.
A hard coat layer having a thickness of 3 μm was formed on one surface of the laminated film prepared in Example 1 using the coating liquid C-1.
The warpage after laminating the hard coat layer was almost 0.5 mm and hardly warped. Further, the in-plane retardation (R) after hard coat lamination was 1.0 nm, and the thickness direction retardation (Rth) was 2.0 nm.

[Example 13]
On the hard coat layer of the laminated film with the hard coat layer prepared in Example 12, using an indium oxide-tin oxide target having a mass ratio of indium oxide and tin oxide of 95: 5 and a packing density of 98%, A crystalline transparent conductive layer (ITO layer) was formed by sputtering. The thickness of the ITO layer was about 130 nm, and the surface resistance value was about 50Ω / □ (Ω / sq).
As a result of conducting a heat cycle test on this transparent conductive film, the transparent conductive film had no fine cracks as before the test. The surface resistance value after the test was about 55Ω / □ (Ω / sq).

[Comparative Example 11]
A hard coat layer having a film thickness of 3 μm was formed on the surface of the laminated film prepared in Comparative Example 6 using a UV curable polyfunctional acrylate resin coating on which the protective layer was thinly applied.
The warp after laminating the hard coat layer was 7.5 mm. Further, the in-plane retardation (R) after hard coat lamination was 1.0 nm, and the thickness direction retardation (Rth) was 2.0 nm.

[Comparative Example 12]
On the hard coat layer of the laminated film with a hard coat layer prepared in Comparative Example 10, using an indium oxide-tin oxide target having a composition of a mass ratio of indium oxide and tin oxide of 95: 5 and a packing density of 98%, A crystalline transparent conductive layer (ITO layer) was formed by sputtering. The thickness of the ITO layer was about 130 nm, and the surface resistance value was about 50Ω / □ (Ω / sq).
As a result of performing a heat cycle test on this transparent conductive film, the transparent conductive film had many fine cracks unlike before the test. The surface resistance value after the test was about 2000Ω / □ (Ω / sq).

  As is clear from Table 1, in the laminated films of Examples 1 to 11, the adhesion between the inorganic glass film and the protective layer is good, and the warp of the film due to environmental changes during lamination is small, and further, The impact property was good. On the other hand, as is clear from Table 2, the laminated film of the comparative example had problems such as poor adhesion, large warpage of the film due to lamination and environmental changes, and low impact resistance.

  Moreover, since the transparent conductive film of Example 13 did not have the curvature deformation | transformation of the film by an environmental change, even if it did the heat cycle test, a transparent conductive film was not destroyed and it was able to maintain favorable electroconductivity. On the other hand, since the transparent conductive film of Comparative Example 11 has a large warp deformation due to environmental changes, the transparent conductive film after the heat cycle test was destroyed and the conductivity decreased.

  The laminated film of the present invention can be used as a transparent substrate in display elements such as liquid crystal displays, organic EL displays, and electronic paper. Moreover, it can be used as a transparent electrode substrate of lighting devices such as organic EL lighting. Moreover, it can be used as a transparent electrode substrate of solar cells such as thin film silicon solar cells, thin film compound solar cells, and organic thin film solar cells. In particular, it is suitably used as a substrate for forming a circuit board on which TFTs for driving the display element are formed, a light emitting layer of an organic EL, or a semiconductor layer of a solar cell (a charge or hole generation layer).

11, 21, 31 Inorganic glass film 12, 22, 32 Adhesive layer 13, 23, 33 Protective layer 24, 34 Hard coat layer 35 Transparent conductive layer 10 Laminated film 20 Laminated film with hard coat 30 Transparent conductive laminated film

Claims (11)

A laminated film in which an adhesive layer made of a polymer and a protective layer made of a heat-resistant organic polymer are sequentially coated on both surfaces of an inorganic glass film, and the following (1) to (7)
(1) The laminated film has a symmetrical structure in the thickness direction (2) The thickness of the inorganic glass film is 5 μm to 200 μm
(3) The thickness of the adhesive layer is 0.01 μm to 1 μm
(4) The thickness of one side of the protective layer is 5 μm to 200 μm
(5) The ratio of the thickness of the inorganic glass film to the total thickness of the protective layer (total of both surfaces) is 0.20 ≦ the thickness of the inorganic glass film (μm) / the total thickness of the protective layer (μm) ≦ 10
(6) The total light transmittance of the laminated film is 85% or more and the haze is 1% or less. (7) The in-plane retardation (R) at a wavelength of 550 nm of the laminated film is 0 to 5 nm and the thickness at a wavelength of 550 nm. direction of the phase difference _{(R th)} is 0nm~50nm
_{[R th} is the optical film at a wavelength of _{550nm R th = [n z -} (n x + n y) / 2] × d ( _{wherein, n x, n y, n} z are each of three-dimensional refractive index of the optical film It is a refractive index in the x-axis, y-axis, and z-axis directions, and d is a value calculated by the film thickness (nm). ]
And a laminated film suitable as a substrate for electronic components. The ratio of the thickness of the inorganic glass film and the total thickness of the protective layer (total of both surfaces) is
0.50 ≦ Inorganic glass film thickness (μm) / Total thickness of protective layer (μm) ≦ 2.0
The laminated film according to claim 1, wherein   The laminated film according to claim 1 or 2, wherein the heat-resistant organic polymer is a thermoplastic resin having a glass transition temperature of 200 ° C or higher, or a thermosetting resin. The laminated film according to any one of claims 1 to 3, wherein an absolute value of a photoelastic coefficient of the heat-resistant organic polymer at a wavelength of 550 nm is 80 x 10 ^-12 Pa ^-1 or less.   The laminated film according to claim 1, wherein the heat-resistant organic polymer has a water absorption rate of 1.0% or less.   The laminated film according to any one of claims 1 to 5, wherein the heat-resistant organic polymer has an average linear expansion coefficient in the range of 50 ° C to 150 ° C of 0 to 100 ppm / ° C.   The heat-resistant organic polymer is mainly composed of any one selected from the group consisting of polycarbonate, polyester, polyimide, polyetherimide, polyarylate, polysulfone, polyethersulfone, amorphous polyolefin, acrylic resin, and epoxy resin. The laminated film according to any one of 1 to 6.   The laminated film according to any one of claims 1 to 7, wherein the adhesion between the inorganic glass film and the protective layer is 80% or more in terms of the number of grids not peeled in the grid test / the number of all grids.   A laminated film with a hard coat, further comprising a hard coat layer on one side or both sides of the laminated film according to claim 1.   A transparent conductive laminated film, further comprising a transparent conductive layer on one or both sides of the laminated film according to claim 1 or the hard coated laminated film according to claim 9.   An electronic component comprising the transparent conductive laminated film according to claim 10.

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