JP7677152B2 - Functional film, functional film with adhesive layer, and functional laminated glass - Google Patents

Description

The present invention relates to a functional film, a functional film with an adhesive layer, and functional laminated glass having a functional film.

As functional laminated glass in which a functional film is sandwiched between two transparent substrates, the following are known.
A transparent screen in which an image display film, in which an image display layer is laminated onto a base film, is sandwiched between two transparent base materials via an adhesive layer (Patent Document 1).
- Heat reflective laminated glass in which a heat reflective film, which is a base film with a heat reflective layer laminated thereon, is sandwiched between two transparent base materials via an adhesive layer.
- Decorative laminated glass in which a decorative film with a design layer such as a pattern laminated onto a base film is sandwiched between two transparent base materials via an adhesive layer.

Functional laminated glass is produced by stacking a glass plate, an interlayer film serving as an adhesive layer, a functional film, an interlayer film serving as an adhesive layer, and a glass plate in this order, and then heating and bonding them together.
However, when a functional layer (such as an image display layer, a heat ray reflective layer, or a design layer) contains a reflective film, depending on the materials of the adhesive layer or base film, wrinkles may occur in the functional film during production of the functional laminated glass due to differences in the thermal shrinkage rates between the functional layer and the adhesive layer or between the functional layer and the base film.

As a functional film that can produce functional laminated glass that is less prone to wrinkles, a functional film has been proposed in which a functional layer is laminated onto a support film, and the thermal shrinkage rate at 130°C in direction A, where the thermal shrinkage rate at 130°C is maximum, is 0.4 to 0.8%, and the thermal shrinkage rate at 130°C in direction B perpendicular to direction A is 0.1 to 0.4% (Patent Document 2).

International Publication No. 2017/195697 JP 2019-32414 A

However, in the functional film of Patent Document 2, a functional layer is laminated on a support film, and therefore light scattering and perspective distortion due to the difference in refractive index occur at the interface between the support film and the functional layer, and birefringence due to the support film may occur, which may impair the visibility and transparency of the functional film.
On the other hand, when the support film is removed from the functional film of Patent Document 2, the occurrence of wrinkles cannot be sufficiently suppressed. In particular, when the functional layer includes a reflective film, the reflective film is likely to be wrinkled or cracked. In particular, when the glass plate has a curved shape, wrinkles and cracks in the reflective film are likely to occur.

The present invention provides a functional film and a functional film with an adhesive layer that can be used to produce functional laminated glass in which wrinkles are unlikely to occur in the functional film even if the functional film with a reflective film does not have a support film, and in which high visibility is maintained.The present invention also provides a functional laminated glass in which wrinkles are unlikely to occur in the functional film even if the functional film with a reflective film does not have a support film, and in which high visibility is maintained.

The present invention has the following aspects.
<1> A functional film having one or more transparent resin layers containing a transparent resin as a main component and a reflective film,
The product of the tensile modulus (GPa) of the transparent resin at 20°C and the thickness (μm) of the functional film is 300 (GPa μm) or more;
A functional film having a total light transmittance of 5 to 90%.
<2> The functional film according to <1> above, wherein the transparent resin has a linear expansion coefficient of 50 (ppm/K) or more.
<3> The functional film according to <1> or <2>, wherein the product is 5,000 (GPa·μm) or less.
<4> The functional film has, as the one or more transparent resin layers, a first transparent resin layer located on one side of the reflective film and a second transparent resin layer located on the other side of the reflective film,
the first transparent resin layer has an uneven structure on a surface thereof facing the reflective film,
the reflective film is provided along the surface of the first transparent resin layer and has a concave-convex structure conformal to the concave-convex structure of the first transparent resin layer;
The functional film according to any one of <1> to <3>, wherein the second transparent resin layer has an uneven structure on a surface on the reflective film side.
<5> The functional film according to <4> above, further comprising an adhesive layer between the reflective film and the second transparent resin layer.
<6> A functional film with an adhesive layer, comprising the functional film according to any one of <1> to <5> above, and an adhesive layer laminated on either one or both of one surface and the other surface of the functional film.
<7> The functional film with an adhesive layer according to <6> above, which satisfies the following formula 1:
Formula 1: CTE _b ×0.2≦CTE _a ≦CTE _b ×1.2
Here, CTE _a indicates the linear expansion coefficient (ppm/K) of the transparent resin of the functional film, and CTE _b indicates the linear expansion coefficient (ppm/K) of the adhesive layer.
<8> A functional laminated glass comprising a first transparent substrate, a first adhesive layer, any one of the functional films <1> to <5>, a second adhesive layer, and a second transparent substrate laminated in this order.
<9> The functional laminated glass according to <8> above, which satisfies the following formulae 2 and 3:
Formula 2: CTE _b1 ×0.2≦CTE _a ≦CTE _b1 ×1.2
Formula 3: CTE _b2 ×0.2≦CTE _a ≦CTE _b2 ×1.2
Here, CTE _a indicates the linear expansion coefficient (ppm/K) of the transparent resin of the functional film, CTE _b1 indicates the linear expansion coefficient (ppm/K) of the first adhesive layer, and CTE _b2 indicates the linear expansion coefficient (ppm/K) of the second adhesive layer.
<10> The functional laminated glass according to <8> or <9> above, wherein the functional film has at least one resin layer having a glass transition temperature of 140° C. or lower.
<11> The functional laminated glass according to any one of <8> to <10>, which is a transparent screen, a heat reflective laminated glass, a design laminated glass or a mirror laminated glass.

According to the functional film of the present invention, even if the functional film having a reflective film does not have a support film, wrinkles are unlikely to occur in the functional film, and functional laminated glass that maintains high visibility can be produced.
According to the functional film with an adhesive layer of the present invention, even if the functional film having a reflective film does not have a support film, wrinkles are less likely to occur in the functional film, and functional laminated glass that maintains high visibility can be produced.
In the functional laminated glass of the present invention, even if the functional film provided with a reflective film does not have a support film, wrinkles are unlikely to occur in the functional film and high visibility is maintained.

The dimensional ratios in FIGS. 1 to 4 are different from the actual ones for the sake of convenience of explanation.
1 is a cross-sectional view showing an example of a reflective image display film which is a first embodiment of the functional film of the present invention. 1A to 1C are cross-sectional views showing an example of a manufacturing process for a reflective image display film. 1 is a cross-sectional view showing an example of an adhesive layer-attached reflective image display film, which is a first embodiment of an adhesive layer-attached functional film of the present invention. FIG. 1 is a layer structure diagram showing an example of a reflective transparent screen which is a first embodiment of the functional laminated glass of the present invention.

The following definitions of terms apply throughout the specification and claims.
The "first surface" refers to the outermost surface of an image display film or transparent screen, the surface onto which image light is projected from a projector.
The "second surface" refers to the outermost surface of the image display film or transparent screen, which is the surface opposite to the first surface.
The "view from the first surface side (second surface side)" means an image seen on the other side of the image display film or transparent screen by an observer on the second surface side (first surface side) of the image display film or transparent screen. The view does not include an image that is displayed by focusing the image light projected from a projector on the image display film or transparent screen.
The term "uneven structure" refers to an uneven shape consisting of a plurality of projections, a plurality of recesses, or a plurality of projections and recesses.
The "film" may be a sheet or a continuous strip. In this specification and claims, the term "to" indicating a range of values means that the range includes the values before and after the range as the lower and upper limits.
The "tensile modulus" is measured by the method described in the Examples below.
"Total light transmittance" is measured in accordance with JIS K 7361:1997 (ISO13468-1:1996).
The "coefficient of linear expansion" (hereinafter also referred to as "CTE") is measured by the method described in the examples below.

<Functional Film>
The functional film of the present invention has one or more transparent resin layers and a reflective film.

A reflective film is a film that reflects part of the incident light and transmits part of it.
The reflective film is used for the purpose of imparting functionality to the functional film. Examples of the functions imparted by the reflective film include an image display function, a heat ray reflection function, design, a light control function, and a mirror function. The reflective film will be described in detail later.

The transparent resin layer contains a transparent resin as a main component.
"Containing a transparent resin as a main component" means that the proportion of the transparent resin in the total mass of the transparent resin layer is 80% by mass or more, preferably 90% by mass or more, and may be 100% by mass.
The transparent resin layer may contain organic materials, inorganic materials, etc. other than the transparent resin as necessary. Examples of inorganic materials include metals, metal oxides, glass, quartz, ceramics, and carbon-based materials (carbon black, etc.). Examples of organic materials include silane coupling agents such as acryloxysilanes, or acrylic or silicone leveling agents.

Examples of the transparent resin include a cured product of a curable resin and a thermoplastic resin.
Examples of the curable resin include photocurable resins (acrylic resins, epoxy resins, etc.) and thermosetting resins (acrylic resins, epoxy resins, etc.).
Examples of thermoplastic resins include polyesters (polyethylene terephthalate (hereinafter also referred to as "PET"), polyethylene naphthalate, etc.), acrylic resins, polyolefins, cycloolefin polymers (hereinafter also referred to as "COP"), polycarbonates, polyimides, urethane resins, ionomers, polyvinyl acetal-based resins (polyvinyl butyral (hereinafter also referred to as "PVB"), etc.), ethylene-vinyl acetate copolymers (hereinafter also referred to as "EVA"), fluororesins, and silicone resins.

From the viewpoint of moldability, the transparent resin preferably contains a cured product of a curable resin.
As the curable resin, a photocurable acrylic resin is preferable from the viewpoint of being able to be cured instantly by irradiation with ultraviolet (UV) light.
Photocurable acrylic resins include (meth)acrylate monomers, (meth)acrylate oligomers, and mixtures thereof. "(Meth)acrylate" is a general term for acrylate and methacrylate.
Examples of the (meth)acrylate monomer include monofunctional (meth)acrylate monomers such as isobornyl acrylate; and polyfunctional (meth)acrylate monomers such as tricyclodecane dimethanol diacrylate, fluorene (meth)acrylate, and tricyclodecane dimethylol diacrylate.
Examples of the (meth)acrylate oligomer include urethane (meth)acrylates having one or more urethane bonds, poly(meth)acrylates of polyoxyalkylene polyols, and poly(meth)acrylates of polyester polyols.

From the viewpoints of the viscosity of the coating liquid for forming the transparent resin layer and the strength of the cured film (transparent resin layer), it is preferable that the photocurable acrylic resin contains a polyfunctional (meth)acrylate monomer.
The content of the polyfunctional (meth)acrylate monomer is preferably from 5 to 100% by mass, and more preferably from 80 to 100% by mass, based on the total mass of the photocurable acrylic resin.

From the viewpoint of high CTE, the photocurable acrylic resin preferably contains a (meth)acrylate oligomer. Among (meth)acrylate oligomers, it is preferable to contain a urethane (meth)acrylate, since the mechanical properties, adhesion, elongation, etc. of the cured resin can be widely adjusted by the molecular design of the urethane chain, etc.
The number average molecular weight of the urethane (meth)acrylate is preferably 300 or more, more preferably 500 or more. The upper limit of the number average molecular weight is, for example, 10,000. The number average molecular weight of the urethane (meth)acrylate is a polystyrene-equivalent number average molecular weight obtained by measurement using gel permeation chromatography (GPC). In addition, when a peak of an unreacted low molecular weight component (monomer, etc.) appears in the measurement using GPC, the peak is excluded to obtain the number average molecular weight.
The content of the urethane (meth)acrylate is preferably from 5 to 80% by mass, and more preferably from 30 to 60% by mass, based on the total mass of the photocurable acrylic resin.

The tensile modulus of the transparent resin at 20°C (hereinafter also referred to as "tensile modulus (20°C)") is preferably 1 to 5 GPa, more preferably 1.5 to 4.0 GPa, and even more preferably 2 to 3.5 GPa. If the tensile modulus of the transparent resin (20°C) is equal to or greater than the above lower limit, the product of the tensile modulus of the transparent resin (20°C) (GPa) and the thickness of the functional film (μm) can be 300 (GPa·μm) or more, even if the functional film is thin. If the tensile modulus (20°C) is equal to or less than the above upper limit, the cured film has excellent crack resistance.

The CTE of the transparent resin is preferably 50 (ppm/K) or more, more preferably 50 to 300 (ppm/K), further preferably 100 to 280 (ppm/K), and particularly preferably 150 to 250 (ppm/K).
In the functional laminated glass, the adhesive layer that bonds the adhesive layer and the transparent substrate is likely to shrink during the production of the functional laminated glass. If the CTE of the transparent resin is equal to or greater than the lower limit, the difference in shrinkage rate between the functional layer and the adhesive layer during the production of the functional laminated glass is small, and the occurrence of wrinkles in the functional film can be more effectively suppressed. If the CTE of the transparent resin is equal to or less than the upper limit, the tensile modulus (20°C) is easily within the above-mentioned preferred range.

In the functional film of the present invention, the product of the tensile modulus (20°C) (GPa) of the transparent resin of the transparent resin layer and the thickness (μm) of the functional film is 300 (GPa·μm) or more, preferably 400 (GPa·μm) or more, and more preferably 500 (GPa·μm) or more. If the product is equal to or more than the lower limit, wrinkles are less likely to occur in the functional film in the functional laminated glass. In addition, wrinkles are less likely to occur in the functional film, and thus wrinkles and cracks are less likely to occur in the reflective film.
From the viewpoint of resistance to cracking, the product of the tensile modulus (20°C) (GPa) of the transparent resin and the thickness (μm) of the functional film is preferably 5,000 (GPa·μm) or less, more preferably 3,000 (GPa·μm) or less, and even more preferably 1,000 (GPa·μm) or less.
The thickness of the functional film varies depending on the function of the functional film and the tensile modulus of elasticity (20° C.) of the transparent resin, but is, for example, 10 to 1000 μm, preferably 15 to 500 μm, and more preferably 50 to 400 μm.

The total light transmittance of the functional film of the present invention is 5 to 90%. If the total light transmittance is equal to or greater than the lower limit, the transparency of the functional film and the visibility of the background are excellent. The total light transmittance is preferably 10% or more, more preferably 15% or more, and even more preferably 50% or more. On the other hand, if the total light transmittance is equal to or less than the upper limit, the function of the functional film can be properly expressed. The total light transmittance of the functional film can be adjusted by the ratio of the transparent resin to the total mass of the functional film, the material constituting the reflective film, the film thickness, etc.

The proportion of the transparent resin to the total mass of the functional film is preferably 90% by mass or more, and more preferably 95% by mass or more, from the viewpoint of the transparency of the functional film.
The upper limit of the proportion of the transparent resin to the total mass of the functional film varies depending on the function of the functional film, but is, for example, 99.9 mass %.

The functional film may take any form having one or more transparent resin layers and a reflective film, and examples include an image display film having an image display layer with a reflective film, a heat ray reflective film having a heat ray reflective layer with a reflective film, a design film having a design layer with a reflective film, and a mirror film having a half mirror layer with a reflective film.

The image display film is a film through which the view on the other side of the film can be seen and which displays the image light projected onto the film so as to be visibly recognized as an image. Specifically, the image display film is a film having a first surface and a second surface opposite thereto, which transmits the view on the first surface side so as to be visibly recognized by an observer on the second surface side and transmits the view on the second surface side so as to be visibly recognized by an observer on the first surface side, and which displays the image light projected from a projector installed on the first surface side so as to be visibly recognized as an image by either the observer on the first surface side or the observer on the second surface side.
The image display film may be a reflective image display film that displays the image light projected from the first surface side so that it is visible to an observer on the first surface side as an image, or it may be a transmissive image display film that displays the image light projected from the first surface side so that it is visible to an observer on the second surface side as an image.

An example of an image display layer having a reflective film is a light scattering layer in which a reflective film having an uneven structure is embedded in a transparent resin layer.
An example of a heat ray reflective layer having a reflective film is a layer in which a high refractive index layer and a low refractive index layer are alternately laminated on a transparent resin layer.
An example of a design layer having a reflective film is a printed layer formed by printing a reflective film-forming ink in a desired design on a transparent resin layer.
An example of a mirror layer having a reflective film is a half-mirror layer laminated on a transparent resin layer, that is, a mirror layer having a reflective film that reflects part of incident light and transmits part of it.
The functional layer including the reflective film may include two or more layers selected from the above-mentioned functional layers.
The functional film may further include a protective layer or an ultraviolet absorbing layer. The protective layer is a layer provided on the outermost surface of the functional film to protect the surface of the functional layer or the surface of the transparent resin layer. Examples of the protective layer include a hard coat layer made of a cured product of a curable resin.
Hereinafter, an embodiment of the functional film of the present invention will be described.

(Reflective image display film)
FIG. 1 is a cross-sectional view showing an example of a reflective image display film, which is a first embodiment of the functional film of the present invention.
The reflective image display film 10 has a light scattering layer 11 (an image display layer having a reflective film).
The light scattering layer 11 has a reflective film 15, a first transparent resin layer 13 located on one side of the reflective film 15, and a second transparent resin layer 19 located on the other side of the reflective film 15. In addition, an adhesive layer 17 is provided between the reflective film 15 and the second transparent resin layer 19.
The first transparent resin layer 13 has an uneven structure on the surface on the reflective film 15 side.
The reflective film 15 is provided along the surface of the first transparent resin layer 13 , and has an uneven structure conforming to the uneven structure of the first transparent resin layer 13 .
The second transparent resin layer 19 has an uneven structure on the surface on the reflective film 15 side.

The first transparent resin layer 13 and the second transparent resin layer 19 are each a layer containing the above-mentioned transparent resin as a main component.
The transparent resins of the first transparent resin layer 13 and the second transparent resin layer 19 may be the same or different, but are preferably the same. When the first transparent resin layer 13 and the second transparent resin layer 19 are made of the same material, they have the same refractive index, and therefore have excellent transparency.
The preferred range of the tensile modulus (20° C.) of the transparent resin of each transparent resin layer is as described above.
The product of the tensile modulus (20° C.) (GPa) of the transparent resin of each transparent resin layer and the thickness (μm) of the reflective image display film 10 is 300 (GPa·μm) or more. The preferable lower and upper limits of this product are as described above.
The thickness of the reflective image display film 10 is, for example, 10 to 1000 μm, preferably 15 to 500 μm, and more preferably 50 to 400 μm.

The uneven structure on the surface of the first transparent resin layer 13 is provided for the purpose of imparting an uneven structure to the reflective film 15 .
The uneven structure on the surface of the first transparent resin layer 13 may be a regular uneven structure (such as a microlens array structure) in which a plurality of convex portions (or a plurality of concave portions) are periodically arranged, or may be a random uneven structure. In this embodiment, the cross-sectional shape of the convex portion (or concave portion) is approximately a right-angled triangle, and one of the two oblique sides adjacent at a right angle is the base. However, the cross-sectional shape of the convex portion (or concave portion) is not limited to this, and may be, for example, a triangle other than a right-angled triangle, a sawtooth shape, an arch shape, or a shape derived from these.
In the uneven structure on the surface of the first transparent resin layer 13, the maximum height of the convex portion (or the maximum depth of the concave portion) is, for example, 1 to 30 μm, preferably 2 to 20 μm, and more preferably 3 to 15 μm. If it is equal to or less than the upper limit of the above range, the transparency of the functional film can be prevented from being impaired, and if it is equal to or more than the lower limit, the desired uneven structure can be imparted to the reflective film 15. Here, the maximum height of the convex portion (or the maximum depth of the concave portion) in the uneven structure of the first transparent resin layer 13 refers to the distance between a horizontal plane passing through the highest position P ₁₁ of the uneven structure (i.e., the position closest to the second transparent resin layer 19) and a horizontal plane passing through the lowest position P 12 of the uneven structure (i.e., the position closest to the second transparent resin layer 19) when the second transparent resin layer 19 side in the thickness direction of the reflective image display film ₁₀ (the upper side in the vertical direction in FIG. 1) is taken as the upper side.
The arrangement direction of the multiple convex portions (or multiple concave portions) may be one or more. The pitch of the multiple convex portions (or multiple concave portions) is, for example, 15 to 300 μm, preferably 15 to 200 μm, and more preferably 15 to 100 μm. If it is equal to or less than the upper limit of the above range, the shape of the concave-convex structure can be narrowed to an extent that it is not visible to the observer, and if it is equal to or more than the lower limit, processing of the concave-convex structure becomes easy.
A fine uneven structure is provided on the surface of the convex portion (or concave portion). The fine uneven structure is an uneven structure for diffusively reflecting the light of an image forward, and is provided for the purpose of image display. The height difference of the fine uneven structure is, for example, 0.5 to 3.0 μm. Here, the height difference of the fine uneven structure is the height difference between adjacent concave and convex portions of the fine uneven structure of the first transparent resin layer 13, and can be calculated by the arithmetic mean roughness Ra of the fine uneven structure.
The maximum thickness of the first transparent resin layer 13 is, for example, 2 to 250 μm, preferably 4 to 200 μm, and more preferably 5 to 150 μm. Here, the maximum thickness of the first transparent resin layer 13 refers to the shortest distance from the highest position P11 of the uneven structure on the surface of the first transparent resin layer 13 to the surface (smooth surface) of the first transparent resin layer 13 opposite to the reflective film 15 side, when the second transparent resin layer 19 side in the thickness direction of the reflective image display film 10 (the upper side in the vertical direction in FIG. ₁ ) is considered to be the upper side.

The reflective film 15 may transmit a part of the light incident on the reflective film 15 and reflect the other part. The reflective film 15 is typically made of an inorganic material. Examples of the inorganic material include metals, metal oxides, and metal nitrides. Examples of the metal include Al, Ag, Cr, Mo, In, Ni, Ta, Ti, Cu, and W. The same can be used as the metal in the metal oxide and metal nitride. The reflective film 15 may be a single layer film or a multilayer film.
Examples of the reflective film 15 include a metal film, a semiconductor film, a dielectric single layer film, a dielectric multilayer film, and a combination thereof. Among these, a metal film or a metal oxide film containing at least one selected from the group consisting of Al, Ag, Cr, Mo, In, Ni, Ta, Ti, Cu, and W is preferable.

The reflective film 15 is formed along the surface of the first transparent resin layer 13, and has an uneven structure conforming to the uneven structure of the first transparent resin layer 13. That is, the shapes of the surfaces of the reflective film 15 on the first transparent resin layer 13 side and the side opposite to the first transparent resin layer 13 follow the shape of the surface of the first transparent resin layer 13 on the reflective film 15 side, and are substantially conformal to the uneven surface of the first transparent resin layer 13. The uneven structure of each surface of the reflective film 15 is a structure in which a plurality of convex portions (or a plurality of concave portions) are periodically arranged, similar to the uneven structure of the surface of the first transparent resin layer 13, and a fine uneven structure is provided on the surface of the convex portions (or concave portions).
The thickness of the reflective film 15 is, for example, 5 to 5000 nm. The thickness of the reflective film 15 can be calculated by observing the thickness of the portion having the maximum height of the convex portion in an electron microscope photograph of the cross section of the concave-convex portion.

If the reflective image display film 10 has the adhesive layer 17, it is possible to improve the adhesion between the reflective film 15 and the second transparent resin layer 19. In addition, it is possible to reduce the influence of volumetric shrinkage on the reflective film 15 when the second transparent resin layer 19 is formed on the adhesive layer 17, which is preferable because it is possible to suppress cracks in the reflective film 15.
The material of the adhesion layer 17 is preferably a thermoplastic resin such as COP, acrylic resin, polyester, urethane resin, polycarbonate, PVB, EVA, etc. If the material of the adhesion layer 17 is a thermoplastic resin, the volumetric shrinkage when the adhesion layer 17 is formed on the reflective film 15 can be reduced compared to a cured product of a curable resin, and cracks in the reflective film 15 can be suppressed. In addition, the effect of volumetric shrinkage on the reflective film 15 when the second transparent resin layer 19 is formed on the adhesion layer 17 can be more effectively mitigated.

The adhesive layer 17 is formed along the surface of the reflective film 15, and the shape of the surface of the adhesive layer 17 opposite to the reflective film 15 (the second transparent resin layer 19 side) generally follows the shape of the surface of the reflective film 15. The uneven structure of the surface of the adhesive layer 17 opposite to the reflective film 15 is a structure in which a plurality of convex portions (or a plurality of concave portions) are periodically arranged, like the uneven structure of the surface of the reflective film 15, but a fine uneven structure is not provided on the surface of the convex portions (or concave portions). The fine uneven structure of the convex portions of the uneven structure of the reflective film 15 is filled in and flattened by the adhesive layer 17. The flattening of the fine uneven structure provides excellent coating properties for the second transparent resin layer.
The thickness of the adhesive layer 17 is, for example, 0.5 to 5 μm, and is determined by measuring the thickness of a portion of the adhesive layer 17 having the minimum height of a recess on the reflective film 15 side with a thickness meter.

The second transparent resin layer 19 is formed so as to cover the surface of the adhesive layer 17, and the shape of the surface on the adhesive layer 17 side follows the shape of the surface on the second transparent resin layer 19 side of the adhesive layer 17. The uneven structure of the surface on the adhesive layer 17 side of the second transparent resin layer 19 is a structure in which a plurality of convex portions (or a plurality of concave portions) are periodically arranged, similar to the uneven structure of the surface of the adhesive layer 17, and a fine uneven structure is not provided on the surface of the convex portions (or concave portions). The surface of the second transparent resin layer 19 opposite to the adhesive layer 17 side is a smooth surface.
In the uneven structure on the surface of the second transparent resin layer 19, the maximum height of the convex portion (or the maximum depth of the concave portion) is, for example, 1 to 30 μm, preferably 2 to 20 μm, and more preferably 3 to 15 μm. If it is equal to or less than the upper limit of the above range, the transparency of the functional film can be prevented from being impaired, and if it is equal to or more than the lower limit, the desired uneven structure can be imparted to the reflective film 15. Here, the maximum height of the convex portion (or the maximum depth of the concave portion) in the uneven structure of the second transparent resin layer 19 refers to the distance between a horizontal plane passing through the highest position P ₂₁ of the uneven structure (i.e., the position closest to the first transparent resin layer 13 side) and a horizontal plane passing through the lowest position P 22 of the uneven structure (i.e., the position closest to the first transparent resin layer 13 side) when the second transparent resin layer 19 side in the thickness direction of the reflective image display film ₁₀ (the upper side in the vertical direction in FIG. 1) is the upper side.
The maximum thickness of the second transparent resin layer 19 is, for example, 2 to 250 μm, preferably 4 to 200 μm, and more preferably 5 to 150 μm. Here, the maximum thickness of the second transparent resin layer 19 refers to the shortest distance from the lowest position P22 of the uneven structure on the surface of the second transparent resin layer 19 on the reflection film 15 side to the surface (smooth surface) of the second transparent resin layer ₁₉ opposite to the reflection film 15 side, when the second transparent resin layer 19 side in the thickness direction of the reflective image display film 10 (the upper side in the vertical direction in FIG. 1) is considered to be the upper side.

2 is a cross-sectional view showing an example of a manufacturing process for a film for reflective image display. The film for reflective image display 10 can be manufactured, for example, by a method including the following steps A1 to A7.
Step A1: A coating liquid containing a solvent, a photocurable resin, etc. is applied to the surface of the base film 21, and dried to form an uncured film 13a. A mold M having a concave-convex structure formed on its surface is placed on the uncured film 13a so that the concave-convex structure is in contact with the uncured film 13a.
Step A2: The uncured film 13a is irradiated with ultraviolet light or the like to cure the uncured film 13a, thereby forming the first transparent resin layer 13 having the irregular concave-convex structure of the mold M transferred to its surface. The mold M is peeled off from the surface of the first transparent resin layer 13.
Step A3: A metal is physically vapor deposited on the surface of the first transparent resin layer 13 to form a reflective film 15 made of a thin metal film.
Step A4: A coating liquid containing a solvent, a thermoplastic resin, etc. is applied onto the surface of the reflective film 15 and dried to form an adhesive layer 17.
Step A5: A coating liquid containing a solvent, a photocurable resin, etc. is applied to the surface of the adhesive layer 17 and dried to form an uncured film 19a. A transparent release film F is superimposed on the uncured film 19a.
Step A6: The uncured film 19a is irradiated with ultraviolet light or the like to cure the uncured film 19a, thereby forming the second transparent resin layer 19. The release film F is peeled off from the surface of the second transparent resin layer 19.
Step A7: The base film 21 is peeled off from the first transparent resin layer 13.

The base film 21 may be a single layer film or a laminated film. A transparent film is usually used as the base film 21. As the transparent film, a stretched film is preferable from the viewpoint of mechanical strength, and a biaxially stretched film is more preferable.
Examples of materials for the base film 21 include polyester (PET, polyethylene naphthalate, etc.), polypropylene, polymethyl methacrylate, polycarbonate, triacetyl cellulose, polyvinyl alcohol, polyether ether ketone, and COP.

The uneven structure on the surface of the mold M is an inverted shape of the uneven structure on the surface of the first transparent resin layer 13. The mold M may be, for example, a resin film having an uneven structure formed on its surface. The resin film having an uneven structure formed on its surface may be produced, for example, by sandwiching a resin material between a mold and a base film, transferring the uneven pattern of the mold to the resin and solidifying it, and then applying a dispersion liquid in which fine particles (for example, spherical alumina particles) are dispersed in a photocurable acrylic resin composition onto the transferred uneven pattern, and then irradiating with UV light to form a fine uneven structure. The average particle size of the fine particles is, for example, 0.01 to 10 μm. The average particle size is the median diameter, which is the average particle size (50% diameter) determined by a laser diffraction particle size distribution measuring instrument.
Examples of the method for applying the coating liquid include a die coating method, a blade coating method, a gravure coating method, an inkjet method, and a spray coating method.
Examples of the physical vapor deposition method include a vacuum deposition method and a sputtering method.

The reflective image display film is not limited to the reflective image display film 10 shown in the figure.
For example, the uneven structure on the surface of the first transparent resin layer may be an irregular uneven structure.
The term "irregular concave-convex structure" refers to a concave-convex structure in which protrusions or recesses do not appear periodically and the sizes of the protrusions or recesses are irregular.
Examples of the mold for forming the irregular uneven structure include a resin film having an irregular uneven structure formed on its surface. Examples of the resin film having an irregular uneven structure formed on its surface include a resin film containing fine particles and a resin film that has been subjected to a sandblasting treatment.
Furthermore, if there is no problem with the adhesion between the reflective film and the second transparent resin layer, the adhesion layer may be omitted.

(Mechanism of action)
In the functional film of the present invention described above, the product of the tensile modulus (20°C) (GPa) of the transparent resin and the thickness (μm) of the functional film is 300 (GPa μm) or more. Therefore, even if the functional film provided with a reflective film does not have a support film (substrate film), wrinkles are unlikely to occur in the functional film, and it is possible to produce a functional laminated glass that maintains high visibility.

The functional film of the present invention is a functional film having a transparent resin layer and a reflective film, and is not limited to the functional film of the embodiment shown in the figures, as long as the product of the tensile modulus (20°C) (GPa) of the transparent resin and the thickness (μm) of the functional film is 300 (GPa μm) or more and the total light transmittance is 5 to 90%.
For example, the functional film may be a film for a transmission type image display, a heat ray reflection film, a design film, or a mirror film.

<Functional film with adhesive layer>
The functional film with an adhesive layer of the present invention comprises the functional film of the present invention and an adhesive layer laminated on either one or both of one surface side and the other surface side of the functional film.

FIG. 3 is a cross-sectional view showing an example of an adhesive layer-attached film for reflective image display, which is the first embodiment of the adhesive layer-attached functional film of the present invention.
The adhesive layer-attached film for reflective image display 20 includes the film for reflective image display 10 having the light scattering layer 11 (functional layer) and a first adhesive layer 23 (adhesive layer). The first adhesive layer 23 is laminated on the surface of the light scattering layer 11 on the second transparent resin layer 19 side.

The adhesive layer is for bonding the transparent substrate and the functional film, and is made of, for example, a thermoplastic resin composition mainly composed of a thermoplastic resin. Examples of the thermoplastic resin used in the adhesive layer include thermoplastic resins that have been used for this type of application. Examples of the thermoplastic resin include polyvinyl acetal resins (PVB, etc.), polyvinyl chloride resins, saturated polyester resins, polyurethane resins, ethylene-vinyl acetate copolymer resins (EVA, etc.), ethylene-ethyl acrylate copolymer resins, ionomers (materials in which ethylene-methacrylic acid copolymer molecules are crosslinked with metal ions, etc.), and COP. In terms of heat resistance and weather resistance, the adhesive layer is preferably one containing PVB or EVA.
When adhesive layers are laminated on both one side and the other side of the functional film, the materials of the adhesive layers may be the same or different.
The thickness of the adhesive layer is, for example, 1 μm to 1 mm.

The functional film with an adhesive layer preferably satisfies the following formula 1.
Formula 1: CTE _b ×0.2≦CTE _a ≦CTE _b ×1.2
Here, CTE _a indicates the linear expansion coefficient (ppm/K) of the transparent resin of the functional layer of the functional film, and CTE _b indicates the linear expansion coefficient (ppm/K) of the adhesive layer.
When CTE _a is 0.2 to 1.2 times CTE _b , the difference in shrinkage rate between the functional layer and the adhesive layer is small during production of the functional laminated glass, and wrinkles in the functional film can be more effectively suppressed.
CTE _a is preferably 0.5 to 1.2 times CTE _b , and more preferably 0.7 to 1.1 times CTE _b .
The CTE _b is typically in the range of 50 to 250 (ppm/K).

The functional film with an adhesive layer can be produced by laminating the functional film of the present invention with an intermediate film that will serve as an adhesive layer.
From the viewpoint of heat resistance and weather resistance, the intermediate film preferably contains PVB or EVA.
As the interlayer film, one used for producing laminated glass is preferable because it allows easy stacking.

A functional film with an adhesive layer can also be produced by a transfer method, in which, for example, a functional film is formed on a base film, an adhesive layer is laminated on the surface of the functional film opposite to the base film side, and then the base film is peeled off from the functional film to obtain a functional film with an adhesive layer.
For example, the above-mentioned adhesive layer-attached film 20 for reflective image display can be produced by forming the film 10 for reflective image display (light scattering layer 11) on the base film 21 by the above-mentioned steps A1 to A6, laminating an adhesive layer 23 on the surface of the film 10 for reflective image display opposite the base film 21, and then peeling the base film 21 from the film 10 for reflective image display.

The functional film with an adhesive layer of the present invention can be used, for example, in the production of the functional laminated glass of the present invention.

<Functional laminated glass>
The functional laminated glass of the present invention is obtained by laminating, in this order, a first transparent substrate, a first adhesive layer, the functional film of the present invention, a second adhesive layer, and a second transparent substrate.
That is, the functional laminated glass of the present invention is obtained by sandwiching the functional film of the present invention between two transparent substrates. The transparent substrates and the functional films are bonded to each other by an adhesive layer.

Examples of the material of the transparent substrate (first transparent substrate, second transparent substrate) include glass and transparent resin. The materials of the transparent substrates may be the same or different.
Examples of the glass constituting the transparent substrate include soda-lime glass, non-alkali glass, borosilicate glass, and aluminosilicate glass. The transparent substrate made of glass may be subjected to chemical strengthening, physical strengthening, hard coating, or the like in order to improve durability.
Examples of transparent resins constituting the transparent substrate include polycarbonate, polyester (PET, polyethylene naphthalate, etc.), triacetyl cellulose, COP, polymethyl methacrylate, and fluororesin.
The transparent substrate has a thickness of, for example, 0.2 to 10 mm.

The shape of the transparent substrate may be flat or curved. In the conventional technology, wrinkles tend to occur in the functional film, and in terms of the usefulness of the present invention, a curved shape is preferred.
When the transparent substrate has a curved surface, the surface of the transparent substrate may be entirely curved, or may be composed of a curved portion and a flat portion. When the entire surface is curved, or when the transparent substrate has a plurality of curved portions, the curvature may be constant or may vary depending on the portion. An example of a transparent substrate having a curved surface is a curved shape such that one side is convex and the other side is concave, as seen in windshields (such as automobile front glass). The curved surface here is a macroscopic curved surface that can be ignored in the observation area observed with a laser microscope.
When the transparent substrate has a curved surface, the radius of curvature R of the curved surface can be appropriately set according to the application and type of the transparent substrate, and is not particularly limited, but is, for example, 500 to 5000 mm.

The adhesive layers (first adhesive layer, second adhesive layer) are as described above, and the preferred aspects are also the same.

The functional laminated glass preferably satisfies the following formulae 2 and 3.
Formula 2: CTE _b1 ×0.2≦CTE _a ≦CTE _b1 ×1.2
Formula 3: CTE _b2 ×0.2≦CTE _a ≦CTE _b2 ×1.2
Here, CTE _a is as described above, CTE _b1 indicates the CTE (ppm/K) of the first adhesive layer, and CTE _b2 indicates the CTE (ppm/K) of the second adhesive layer.
When CTE _a is 0.2 to 1.2 times each of CTE _b1 and CTE _b2 , the difference in shrinkage rate between the functional layer and the adhesive layer is small during production of the functional laminated glass, and wrinkles in the functional film can be more effectively suppressed.
CTE _a is preferably 0.5 to 1.2 times each of CTE _b1 and CTE _b2 , and more preferably 0.7 to 1.1 times each of CTE _b1 and CTE _b2 .

The functional laminated glass of the present invention can be produced by a method in which a first transparent substrate, an interlayer film that will serve as a first adhesive layer, the functional film of the present invention, an interlayer film that will serve as a second adhesive layer, and a second transparent substrate are stacked in this order and heated to bond them together.
When the functional laminated glass has a large area, a plurality of functional films may be arranged in the surface direction when the functional film is laminated on the interlayer film.
The preferred embodiment of the interlayer film is as described above.

The heating temperature during bonding is preferably 80 to 150° C., more preferably 90 to 140° C. If the heating temperature is equal to or higher than the lower limit of the above range, the embossing of the interlayer film disappears and haze can be suppressed. If the heating temperature is equal to or lower than the upper limit of the above range, excessive shrinkage of the functional film and the associated generation of wrinkles and bubbles can be suppressed.
The heating time during bonding is preferably 30 to 90 minutes, more preferably 45 to 75 minutes. When the heating time is equal to or more than the lower limit of the above range, the embossing of the interlayer film disappears and haze can be suppressed. When the heating time is equal to or less than the upper limit of the above range, productivity is high and it is economically preferable.

The laminate having the transparent substrate, the intermediate film and the functional film may be placed in a vacuum bag (rubber bag) and pre-bonded at a relatively low temperature in a hot air oven in a vacuumed state, and then transferred to an autoclave and fully bonded at a relatively high temperature under pressure.
The heating temperature during preliminary bonding is preferably 80° C. or higher and lower than 120° C. The heating time during preliminary bonding is preferably 30 to 90 minutes.
The heating temperature during the main bonding is preferably 100 to 150° C. The heating time during the main bonding is preferably 30 to 120 minutes. The pressure during the main bonding is preferably 0.6 to 2.0 MPa [abs.

Considering the above heating process, it is preferable that the functional film has at least one resin layer with a glass transition temperature (Tg) of 140°C or less, since this makes it easier to suppress wrinkles in the functional film. By having at least one resin layer with a Tg of 140°C or less, the stress caused by the CTE difference during heating can be alleviated. An example of a resin layer with a Tg of 140°C or less is the adhesion layer 17. The lower limit of the Tg of the resin layer with a Tg of 140°C or less is not particularly limited, but is, for example, 123°C. The Tg of the resin layer is the midpoint glass transition temperature determined by differential scanning calorimetry (DSC) in accordance with JIS K 6240:2011 (corresponding international standard ISO 22768:2006).

When the functional film has at least one resin layer having a Tg of 140° C. or less, it is preferable in order to maintain the flatness of the film during adhesion that one or more of the other resin layers in the functional film (e.g., resin layers other than the adhesive layer 17, i.e., the first transparent resin layer 13 and/or the second transparent resin layer 19) have a storage modulus/loss modulus of ≧1, i.e., a resin layer that does not have fluidity.
In this case, it is preferable that the total thickness of the resin layers having no fluidity in the functional film is 50 μm to 300 μm, since the flatness of the film can be maintained while wrinkles in the functional film are suppressed. In particular, it is preferable that the total thickness of the resin layers having no fluidity is 50 μm to 200 μm, since the functional film can be easily produced by a roll-to-roll process.

Examples of functional laminated glass include a transparent screen in which an image display film is sandwiched between two transparent substrates via an adhesive layer, heat ray reflecting laminated glass in which a heat ray reflecting film is sandwiched between two transparent substrates via an adhesive layer, decorative laminated glass in which a decorative film is sandwiched between two transparent substrates via an adhesive layer, and mirror laminated glass in which a mirror film is sandwiched between two transparent substrates via an adhesive layer.

A transparent screen is a screen through which the view behind the screen can be seen and which displays the image light projected onto the screen so that it can be seen as an image. Specifically, it is a screen having a first surface and a second surface opposite thereto, which transmits the view on the first surface side so that it can be seen by an observer on the second surface side, transmits the view on the second surface side so that it can be seen by an observer on the first surface side, and displays the image light projected from a projector installed on the first surface side so that it can be seen as an image by either the observer on the first surface side or the observer on the second surface side.
The transparent screen may be a reflective transparent screen that displays the image light projected from the first surface side so that it can be seen by an observer on the first surface side as an image, or may be a transmissive transparent screen that displays the image light projected from the first surface side so that it can be seen by an observer on the second surface side as an image.
Hereinafter, embodiments of the functional laminated glass of the present invention will be described.

(Reflective transparent screen)
FIG. 4 is a layer structure diagram showing an example of a reflective transparent screen which is the first embodiment of the functional laminated glass of the present invention.
The reflective transparent screen 30 has a reflective image display film 10 disposed between a first transparent substrate 27 and a second transparent substrate 29 .
The first transparent substrate 27 and the reflective image display film 10 are bonded together by a first adhesive layer 23 , and the second transparent substrate 29 and the reflective image display film 10 are bonded together by a second adhesive layer 25 .

The materials for the first transparent substrate 27 and the second transparent substrate 29 may be the same as those for the transparent substrates of the above-mentioned functional laminated glass, and the preferred forms are also the same.
The first adhesive layer 23 and the second adhesive layer 25 may be the same as the adhesive layers of the functional laminated glass described above, and the preferred forms are also the same.

In the reflective transparent screen 30, as shown in FIG. 4, the image light L projected from the projector 100 and incident on the first surface S1 of the reflective transparent screen 30 is scattered by the reflective film 15 of the reflective image display film 10 to form an image that is visible to the first observer X on the same side as the projector 100.

After the light of the scene on the first surface S1 enters the reflective transparent screen 30 from the first surface S1, a portion of the light is reflected by the reflective film 15 and the remainder is transmitted. This allows a second observer (not shown) on the second surface S2 to view the scene on the first surface S1. Similarly, after the light of the scene on the second surface S2 enters the reflective transparent screen 30 from the second surface S2, a portion of the light is reflected by the reflective film 15 and the remainder is transmitted. This allows a first observer X on the first surface S1 to view the scene on the second surface S2.

The reflective transparent screen is not limited to the illustrated reflective transparent screen 30. For example, instead of the reflective image display film 10, any of the above-mentioned other types of reflective image display films may be used.
The reflective transparent screen may further include other layers, such as a low-reflection layer that reduces the reflection of light, a light-attenuating layer that attenuates a part of the light, and an infrared shielding layer that blocks infrared rays.

(Mechanism of action)
In the functional laminated glass of the present invention described above, the product of the tensile modulus (20°C) (GPa) of the transparent resin of the transparent resin layer of the functional film and the thickness (μm) of the functional film is 300 (GPa μm) or more. Therefore, even if the functional film provided with a reflective film does not have a support film (substrate film), wrinkles are unlikely to occur in the functional film, and high visibility is maintained.

The functional laminated glass of the present invention may be any glass having a first transparent substrate, a first adhesive layer, the functional film of the present invention, a second adhesive layer, and a second transparent substrate laminated in this order, and is not limited to the functional laminated glass of the illustrated embodiment.
For example, the functional laminated glass of the present invention may be a transmission type transparent screen, a heat ray reflecting laminated glass, a design laminated glass, or a mirror laminated glass.
The functional laminated glass of the present invention may have an area where the functional film is present and an area where the functional film is not present.

The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.
Examples 1-4 are working examples, and Example 3 is a comparative example.

(Preparation of evaluation samples)
The coating liquid used in each example (coating liquid-1 for the first transparent resin layer, or coating liquid-3 for the second transparent resin layer) was applied to the surface of a substrate (PET film) that does not have adhesive properties with the photocurable resin by a roll-to-roll process using a die coating method to prepare a photocurable resin layer, and another substrate (PET film) that does not have adhesive properties with the photocurable resin was laminated from above. Next, the photocurable resin layer was irradiated with 1000 mJ of ultraviolet light to harden the photocurable resin layer and form a transparent resin layer. Thereafter, the transparent resin layer was peeled off from each substrate, and the obtained free-standing film was cut to prepare an evaluation sample. The evaluation sample for measuring the tensile modulus was shaped according to ASTM D1822-L. The evaluation sample for measuring the CTE was a strip of 25 mm in length and 4 mm in width.

(Method of measuring tensile modulus)
For the evaluation samples, a strain-stress curve was measured in accordance with JIS K 7161 (ISO 5271) using a universal testing machine (Orientec Co., Ltd.'s "Tensilon universal material testing machine RTC-1210") at 20°C, with a chuck length of 20 mm and a test speed of 10 mm/min. The initial elastic modulus was calculated from the tangent line giving the maximum gradient near the origin of the curve, and the average value of 10 measured values was taken as the tensile elastic modulus (20°C).

(Method of measuring CTE)
The CTE was measured using a thermomechanical analyzer ("Q400" manufactured by TA Instruments). Specifically, in an air atmosphere, with a chuck length of 8.1 mm, the evaluation sample was heated from 30°C to ¹²⁰ °C at a rate of 5°C/min while applying a load (N) of the cross-sectional area (mm2) of the evaluation sample x coefficient 0.1225 (N/ ^mm2 ), and the displacement amount due to the linear expansion of the length of the evaluation sample was measured. After the measurement was completed, the CTE (ppm/K) at 30 to 120°C was calculated from the displacement amount of the evaluation sample from 30°C to 120°C.

(Method of measuring total light transmittance)
The total light transmittance of the reflective image display film (functional film) was measured in accordance with JIS K 7361: 1997 (ISO 13468-1: 1996). The total light transmittance is the ratio of the total of the light that is transmitted without being diffused and the light that is diffused to the light that is transmitted when light is applied to the test piece.

(Wrinkle evaluation method)
The reflective transparent screen was visually observed, and the state of wrinkles in the reflective image display film was evaluated on an 11-point scale from 0 to 10, with 0 being a score when no wrinkles were observed in the reflective image display film and 10 being a score when many obvious wrinkles were observed in the reflective image display film. The lower the score, the more suppressed the occurrence of wrinkles in the reflective image display film. For example, in the case of a score of 1, wrinkles were observed in the reflective image display film, but the wrinkles were at a level that could not be seen unless one looked closely.

(UV curable resin)
The ultraviolet-curable resins used are as follows:
ADCP: tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight: 304).
6LPA: urethane acrylate oligomer ("U-6LPA" manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight: 760).
UA160: urethane acrylate oligomer ("UA-160TM" manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight: 1600).
UA122: urethane acrylate oligomer ("UA-122P" manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight: 1100).

(Example 1)
A transparent PET film-1 (biaxially stretched film, 150 mm square, 125 μm thick) was prepared.
A transparent PET film-2 (biaxially stretched film, 150 mm square, 125 μm thick) was prepared.
A resin film having a concave-convex structure formed on its surface was prepared as a mold. The concave-convex structure was a structure in which a plurality of convex stripes having a fine concave-convex structure on the surface were arranged in one direction, as shown in Fig. 1, and the cross-sectional shape of the convex stripes was a right-angled triangle, the maximum height was 10 μm, and the pitch was 40 μm. The fine concave-convex structure on the surface of the convex stripes was formed by applying a filler having an average particle size of 1.5 μm.
60 parts by mass of ADCP, 20 parts by mass of 6LPA, and 25 parts by mass of UA160 as photocurable resins were mixed with 3 parts by mass of a photopolymerization initiator to obtain coating solution-1.
90 parts by mass of toluene and 10 parts by mass of cycloolefin polymer were mixed to obtain coating liquid-2.
60 parts by mass of ADCP, 20 parts by mass of 6LPA, and 25 parts by mass of UA160 as photocurable resins were mixed with 3 parts by mass of a photopolymerization initiator to obtain coating solution-3.
Since the photocurable resin in Coating Liquid-1 and Coating Liquid-3 is the same, the tensile modulus and CTE of the formed transparent resin are the same. The measurement results of the tensile modulus and CTE of the transparent resin are shown in Table 1.

Coating liquid-1 was applied to the surface of PET film-1 by a die coating method, and the mold was placed on top of coating liquid-1 so that the concave-convex structure was in contact with the photocurable resin layer.
Next, while the mold was pressed against the coating liquid-1, the photocurable resin layer was irradiated with 1000 mJ of ultraviolet light to cure the photocurable resin layer, thereby forming a first transparent resin layer having the concave-convex structure transferred to its surface. The mold was peeled off from the surface of the first transparent resin layer.

A Ti-doped zinc oxide film (50 nm), AgBiNd (5 nm) and a Ti-doped zinc oxide film (10 nm) were laminated in this order on the surface of the first transparent resin layer by sputtering to form a reflective film with a thickness of 65 nm.
The coating solution-2 was applied to the surface of the reflective film by a die coating method and dried at 110° C. for 4 minutes to form an adhesive layer having a thickness of 1 μm.

Coating liquid-3 was applied to the surface of the adhesive layer by the die coating method, and PET film-2 was superimposed. In this state, 1000 mJ of ultraviolet light was irradiated from the PET film-2 side to cure the photocurable resin layer and form a second transparent resin layer. PET film-2 was peeled off from the second transparent resin layer, and PET film-1 was peeled off from the first transparent resin layer to obtain a reflective image display film with a thickness of 300 μm. The total light transmittance of the obtained reflective image display film was 72.6%.

A glass plate (soda-lime glass, 1500 mm×2400 mm×thickness 12 mm) was prepared as a transparent substrate.
A PVB film (150 mm square, 0.36 μm thick) was prepared as the interlayer. The CTE of the interlayer was 277 ppm/K.
A transparent substrate, an intermediate film, a film for reflective image display, an intermediate film and a transparent substrate were laminated in this order, and the intermediate film and the film for reflective image display protruding from the transparent substrate were cut off to obtain a laminate.
The laminate was placed in a vacuum bag and pre-bonded by heating in a hot air oven at 100°C and 0.015 MPa [abs] for 30 minutes while drawing a vacuum. The pre-bonded laminate was transferred to an autoclave and heated at 130°C and 1.0 MPa [abs] for 60 minutes for main bonding, to obtain a reflective transparent screen.
The reflective transparent screen was evaluated for wrinkles in the reflective image display film. The results are shown in Table 1.

(Example 2)
A reflective image display film (total light transmittance: 73.6%) and a reflective transparent screen were obtained in the same manner as in Example 1, except that the photocurable resins blended in Coating Solution-1 and Coating Solution-3 were changed to 55 parts by mass of ADCP, 20 parts by mass of 6LPA, and 25 parts by mass of UA122.
The measurement results of the tensile modulus and CTE of the transparent resin and the evaluation results of wrinkles are shown in Table 1.

(Example 3)
A film for reflective image display and a reflective transparent screen were obtained in the same manner as in Example 1, except that the photocurable resin to be blended in each of Coating Liquid-1 and Coating Liquid-3 was changed to 100 parts by mass of ADCP. Note that, since wrinkles were generated throughout the entire film in the film for reflective image display in Example 3, the total light transmittance was not measured.
The measurement results of the tensile modulus and CTE of the transparent resin and the evaluation results of wrinkles are shown in Table 1.

(Example 4)
A reflective image display film (total light transmittance: 74%) and a reflective transparent screen were obtained in the same manner as in Example 1, except that the thickness of the functional film in Example 2 was changed to 200 μm.
The measurement results of the tensile modulus and CTE of the transparent resin and the evaluation results of wrinkles are shown in Table 1.

The functional laminated glass of the present invention is useful, for example, as a transparent screen, a heat ray reflecting laminated glass, and a decorative laminated glass.
In addition, the entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2019-188641 filed on October 15, 2019 are hereby incorporated by reference as the disclosure of the specification of the present invention.

10 Reflective image display film, 11 Light scattering layer, 13 First transparent resin layer, 13a Uncured film, 15 Reflective film, 17 Adhesion layer 19 Second transparent resin layer, 19a Uncured film, 20 Reflective image display film with adhesive layer, 23 First adhesive layer, 25 Second adhesive layer, 27 First transparent substrate, 29 Second transparent substrate, 30 Reflective transparent screen, 100 Projector, F Release film, L Image light, M Mold, S1 First surface, S2 Second surface, X Observer.

Claims (10)

A functional film having one or more transparent resin layers mainly composed of a transparent resin and a reflective film,
the functional film has, as the one or more transparent resin layers, a first transparent resin layer located on one side of the reflective film and a second transparent resin layer located on the other side of the reflective film;
the first transparent resin layer has an uneven structure on a surface thereof facing the reflective film,
the reflective film is provided along the surface of the first transparent resin layer and has a concave-convex structure conformal to the concave-convex structure of the first transparent resin layer;
the second transparent resin layer has an uneven structure on a surface thereof facing the reflective film,
The product of the tensile modulus (GPa) of the transparent resin at 20°C and the thickness (μm) of the functional film is 300 (GPa μm) or more;
A functional film having a total light transmittance of 5 to 90%. The functional film according to claim 1, wherein the transparent resin has a linear expansion coefficient of 50 (ppm/K) or more. The functional film according to claim 1 or 2, wherein the product is 5,000 (GPa·μm) or less. The functional film according to any one of claims 1 to 3 , further comprising an adhesive layer between the reflective film and the second transparent resin layer. A functional film with an adhesive layer, comprising: the functional film according to any one of claims 1 to 4 ; and an adhesive layer laminated on either one or both of one surface side and the other surface side of the functional film. The functional film with an adhesive layer according to claim 5 , which satisfies the following formula 1.
Formula 1: CTE _b ×0.2≦CTE _a ≦CTE _b ×1.2
Here, CTE _a indicates the linear expansion coefficient (ppm/K) of the transparent resin of the functional film, and CTE _b indicates the linear expansion coefficient (ppm/K) of the adhesive layer. A functional laminated glass comprising a first transparent substrate, a first adhesive layer, the functional film according to any one of claims 1 to 4 , a second adhesive layer, and a second transparent substrate laminated in this order. The functional laminated glass according to claim 7 , which satisfies the following formula 2 and formula 3.
Formula 2: CTE _b1 ×0.2≦CTE _a ≦CTE _b1 ×1.2
Formula 3: CTE _b2 ×0.2≦CTE _a ≦CTE _b2 ×1.2
Here, CTE _a indicates the linear expansion coefficient (ppm/K) of the transparent resin of the functional film, CTE _b1 indicates the linear expansion coefficient (ppm/K) of the first adhesive layer, and CTE _b2 indicates the linear expansion coefficient (ppm/K) of the second adhesive layer. The functional laminated glass according to claim 7 or 8 , wherein the functional film has at least one resin layer having a glass transition temperature of 140° C. or lower. The functional laminated glass according to any one of claims 7 to 9 , which is a transparent screen, a heat reflective laminated glass, a decorative laminated glass, or a mirror laminated glass.

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