Multilayer laminated film and projection image display member

Abstract

The present invention addresses the problem of providing a multilayer laminated film that is transparent since visible light in the front direction passes therethrough, and has a near-infrared reflection function and a function of reflecting P-wave visible light in a diagonal direction, and is directed to a multilayer laminated film in which at least three resin layers are regularly arranged, and which has all of the following features (1) to (3), when a dielectric constant Xi (i = 1, 2, 3, …) is the dielectric constant, obtained by EELS measurement, of each of the layers at a loss energy of 2.5 eV, and the layers are referred to as layer A, layer B, and layer C in a descending order of the dielectric constant Xi. (1) The multilayer laminated film has a repeating unit structure in which repeating units, each having layer A / layer B / layer C / layer B arranged sequentially, are laminated. (2) Repeating units, each having a total layer thickness of 250-630 nm, account for 80-100% of all repeating units. (3) Layer A is a crystalline thermoplastic resin layer, and layer B and layer C are each a noncrystalline thermoplastic resin layer.

Description

Multilayer laminated film and projection image display member

[0001] The present invention relates to a multilayer laminate film that is transparent and transmits visible light in the front direction, while also reflecting near-infrared light and P-wave visible light in oblique directions. The present invention also relates to a projection image display member using the multilayer laminate film, a projection image display device using the projection image display member, and a vehicle such as an automobile and a building using the projection image display device.

[0002] In recent years, in response to carbon dioxide emission restrictions for environmental protection, heat-cutting glass, which can suppress the inflow of heat from the outside in summer, particularly from sunlight, has attracted attention. Heat-cutting glass is used as window glass for vehicles such as automobiles and trains, and for buildings. Examples of such heat-cutting glass include one in which a heat-absorbing material is contained in glass or an interlayer film used in laminated glass, and the heat-absorbing material blocks heat rays (near-infrared rays) (e.g., Patent Document 1), one in which a metal film is formed on the glass surface by sputtering or the like, thereby blocking near-infrared rays (e.g., Patent Document 2), and one in which a polymer multilayer laminate film, in which polymer layers with different refractive indices are alternately laminated, is inserted between the glass and the interlayer film, thereby blocking heat rays by reflecting near-infrared rays (e.g., Patent Document 3).

[0003] Among these methods, the one using heat-absorbing materials converts sunlight incident from outside into thermal energy, resulting in the problem of the resulting heat being radiated into the room, reducing the heat-blocking efficiency. In addition, the heat-absorbing material absorbs near-infrared rays, causing the glass temperature to rise in parts, and the temperature difference with the outside air can cause the glass itself to break. Furthermore, the method of forming a metal film on the glass surface by sputtering or other methods reflects not only near-infrared rays but also visible light, making it prone to coloration, and also blocking electromagnetic waves, which can make it impossible to use communication devices inside.

[0004] Compared to methods using heat ray absorbing materials, near-infrared reflective polymer multilayer laminate films can selectively reflect near-infrared rays, allowing the layer thickness to be controlled to select the wavelength to be reflected, thereby improving heat ray blocking performance while maintaining visible light transmittance. In addition, because they do not contain materials that block radio waves, such as metals, they maintain excellent radio wave transmittance.

[0005] In response to another demand, a large number of projection image display devices have been installed in automobiles and other transportation vehicles. These devices project S-wave images from a light source onto a projection image display element, superimposing the projected image on a background viewed through the projection image display element. These projection image display devices project S-wave images from a light source onto the projection image display element. To prevent double images due to reflections on the front and back of the projection image display element, some devices incorporate a wedge angle into the interlayer film inserted into the laminated glass (see, for example, Patent Document 4). However, when wearing polarized sunglasses, the S-wave visible light from the light source is absorbed by the polarized sunglasses, making the projected image invisible. To address this issue, a method has been proposed in which a polarized reflective film is placed inside the laminated glass to allow P-wave images to be incident at the glass's Brewster angle (see, for example, Patent Document 5). Another method has been proposed in which a multilayer laminated film is placed inside the laminated glass, which transmits light in the front direction but reflects only P-waves in oblique directions, allowing the P-wave images to be incident at the laminated glass's Brewster angle (see, for example, Patent Document 6).

[0006] Japanese Patent Application Laid-Open No. 2010-17854 Japanese Patent Application Laid-Open No. 2001-310407 International Publication No. 2005 / 040868 International Publication No. 2018 / 181687 International Publication No. 2005 / 017600 International Publication No. 2019 / 198635

[0007] However, the reflective functions of the multilayer laminate film that reflects near-infrared rays described in Patent Document 3 and the multilayer laminate film that reflects P waves in the visible light range described in Patent Document 6 are realized by using different multilayer laminate films. In other words, because near-infrared rays and visible light are in different wavelength ranges, multilayer laminate films with different optical designs are required. Therefore, to impart the dual functions of near-infrared reflection and P wave reflection to laminated glass or the like, two different multilayer laminate films must be used. In this case, two different multilayer laminate films are produced, laminated together, and then applied to the laminated glass. However, the increased film thickness causes wrinkles and distortion in the laminated glass.

[0008] Furthermore, in order to improve the adhesion between the laminated glass and the multilayer laminate film and to make the multilayer laminate film conform to the curved surface shape of the laminated glass, it is common to heat the multilayer laminate film when applying it to the laminated glass. However, it is usually difficult to make the heat shrinkage properties of two different multilayer laminate films the same, and when these multilayer laminate films are laminated, the difference in heat shrinkage properties causes problems such as increased wrinkling and distortion.

[0009] That is, an object of the present invention is to provide a multilayer laminated film that is transparent and transmits visible light in the front direction, while also having the function of reflecting near-infrared light and the function of reflecting P-wave visible light in an oblique direction.

[0010] The present invention is intended to solve the above-mentioned problems, and the first multilayer laminate film of the present invention and the second multilayer laminate of the present invention have the following constitutions.

[0011] The first multilayer laminate film of the present invention is a multilayer laminate film in which three or more types of resin layers are regularly arranged, and the dielectric constant at a loss energy of 2.5 eV obtained by electron energy loss spectroscopy (EELS measurement) is the dielectric constant X of each layer. ｉ (i=1, 2, 3, . . . ), and the dielectric constant X ｉA multilayer laminate film having all of the following (1) to (3), where Layer A is the layer with the largest thickness, followed by Layer B and Layer C. (1) The film has a repeating unit structure in which repeating units are laminated in the order of Layer A / Layer B / Layer C / Layer B. (2) Within each repeating unit, the proportion of units having a total layer thickness within the range of 250 nm to 630 nm accounts for 80% to 100% of all repeating units. (3) The Layer A is a crystalline thermoplastic resin layer, and the Layer B and the Layer C are composed of a combination of amorphous thermoplastic resin layers.

[0012] The second multilayer laminate film of the present invention has a dielectric constant X at a loss energy of 2.5 eV obtained by electron energy loss spectroscopy (EELS measurement). ｉ When the dielectric constant X ｉ a repeating unit structure in which three types of resin layers (A layer, B layer, C layer) having different dielectric constants are arranged in the order of A layer / B layer / C layer / B layer, and the ratio of units in which the total layer thickness within the repeating unit is 250 nm or more and 630 nm or less is 80% or more and 100% or less of all repeating units, and in the repeating unit, the ratio of repeating units in which the stacking ratio (A / B) of the A layer to the total thickness of the B layer and the stacking ratio (C / B) of the C layer to the total thickness of the B layer are each within the range of 0.8 or more and 1.3 or less is 80% or more and 100% or less of all repeating units, and ｉ In this case, the dielectric constant of the A layer is set to X Ａ , the dielectric constant of the B layer is X Ｂ and the dielectric constant of the C layer is X Ｃ When this is done, X Ａ >X Ｂ >X Ｃ and the average visible light reflectance of P waves when incident at an angle of 60° with respect to the normal to the film surface is 10% or more and 99% or less.

[0013] According to the present invention, it is possible to provide a multilayer laminated film that is transparent and transmits visible light in the front direction, yet has the function of reflecting near-infrared light and the function of reflecting P-wave visible light in an oblique direction.

[0014] 1 is a schematic diagram illustrating transmission and reflection of a multilayer laminate film. (a) is a conventional near-infrared-reflecting multilayer laminate film. (b) is a P-wave-reflecting multilayer laminate film. (d) is a multilayer laminate film of the present invention. A schematic diagram illustrating the application of the laminate film of the present invention to laminated glass. A characteristic diagram showing the incidence angle dependence of average reflectance when P-wave and S-wave light having wavelengths of 400 nm to 700 nm is incident. (a) is a conventional transparent resin film, (b) is a conventional light-reflecting multilayer laminate film, (c) is a conventional multilayer laminate film that transmits visible light and reflects near-infrared light, and (d) is a multilayer laminate film of the present invention. A diagram showing the change in refractive index with respect to the incidence angle of layers A, B, and C in Example 1 and Comparative Example 1. A graph comparing the average visible light reflectance of P-waves with the incidence angle of the multilayer laminate film of the present invention with that of the prior art. A schematic diagram illustrating the layer thickness distribution of layers A, B, and C in the multilayer laminate film of the present invention. A schematic diagram illustrating the azimuth angle of the multilayer laminate film of the present invention. A schematic diagram showing an example of a cross section of a projection image display member of the present invention. Fig. 1 is a schematic diagram showing another example of a cross section of a projection image display member of the present invention. Fig. 2 is a schematic diagram illustrating a projection image display device of the present invention. Fig. 3 is a schematic diagram illustrating the effect of mounting a projection image display device of the present invention. Fig. 4 is a schematic diagram illustrating a projection image display device of the present invention. Fig. 5 is a schematic diagram illustrating evaluation of a head-up display in Examples.

[0015] The multilayer laminate film of the present invention will be specifically described below. The multilayer laminate film of the present invention includes the first multilayer laminate film of the present invention and the second multilayer laminate film of the present invention, and these may be collectively referred to as the "multilayer laminate film of the present invention."

[0016] The first multilayer laminate film of the present invention is a multilayer laminate film in which three or more types of resin layers are regularly arranged, and the dielectric constant of each layer at a loss energy of 2.5 eV obtained by electron energy loss spectroscopy (EELS measurement) is a dielectric constant X ｉThis multilayer laminate film is characterized by having all of the following (1) to (3), where (i = 1, 2, 3, ...) where Layer A is the layer with the largest dielectric constant X, followed by Layer B and Layer C. (1) It has a repeating unit structure in which repeating units arranged in the order Layer A / Layer B / Layer C / Layer B are laminated. (2) Within each repeating unit, units with a total layer thickness of 250 nm or more and 630 nm or less account for 80% to 100% of all repeating units. (3) The Layer A, the Layer B, and the Layer C are each composed of a combination of crystalline / amorphous / amorphous thermoplastic resin layers. That is, the Layer A is a crystalline thermoplastic resin layer, and the Layer B and the Layer C are composed of a combination of amorphous thermoplastic resin layers.

[0017] The second multilayer laminate film of the present invention has a dielectric constant X at a loss energy of 2.5 eV obtained by electron energy loss spectroscopy (EELS measurement). ｉ When the dielectric constant X ｉ a repeating unit structure in which three types of resin layers (A layer, B layer, C layer) having different dielectric constants are arranged in the order of A layer / B layer / C layer / B layer, and the ratio of units in which the total layer thickness within the repeating unit is 250 nm or more and 630 nm or less is 80% or more and 100% or less of all repeating units, and in the repeating unit, the ratio of repeating units in which the stacking ratio (A / B) of the A layer to the total thickness of the B layer and the stacking ratio (C / B) of the C layer to the total thickness of the B layer are each within the range of 0.8 or more and 1.3 or less is 80% or more and 100% or less of all repeating units, and ｉ is the dielectric constant X of the A layer Ａ is the largest, followed by the dielectric constant X Ｂ , the dielectric constant X of the C layer Ｃ That is, the dielectric constant X ｉ In this case, the dielectric constant of the A layer is set to X Ａ , the dielectric constant of the B layer is X Ｂ and the dielectric constant of the C layer is X Ｃ When this is done, X Ａ >X Ｂ >X ＣThe multilayer laminate film satisfies the above condition, and has an average visible light reflectance of 10% or more and 99% or less for P waves when incident at an angle of 60° with respect to the normal to the film surface.

[0018] The following describes embodiments of the present invention, but the present invention should not be construed as being limited to the embodiments including the following examples, and various modifications are naturally possible within the scope of achieving the object of the invention and not departing from the gist of the invention.

[0019] The differences between conventional near-infrared-reflecting multilayer laminate films, P-wave-reflecting multilayer laminate films, and the multilayer laminate film of the present invention, which is transparent and transmits visible light in the front direction while also having the function of reflecting near-infrared light and reflecting oblique P-wave visible light (hereinafter referred to as the multilayer laminate film of the present invention), are explained using Figure 1. The conventional near-infrared-reflecting multilayer laminate film 1 shown in Figure 1(a) and the conventional visible light P-wave-reflecting multilayer laminate film 2 shown in Figure 1(b) each have a configuration in which two different thermoplastic resin layers are alternately laminated. The reference numerals 5 to 8 respectively represent one of the two different thermoplastic resin layers 5 of the conventional near-infrared-reflecting multilayer laminate film, the other of the two different thermoplastic resin layers 6 of the conventional near-infrared-reflecting multilayer laminate film, one of the two different thermoplastic resin layers 7 of the conventional P-wave-reflecting multilayer laminate film, and the other of the two different thermoplastic resin layers 8 of the conventional P-wave-reflecting multilayer laminate film.

[0020] On the other hand, the multilayer laminate film 4 of the present invention shown in Figure 1(d) has three resin layers, A layer, B layer, and C layer, each having a different dielectric constant X, and has a repeating unit structure arranged in the order of A layer / B layer / C layer / B layer. In other words, it has a repeating unit structure in which units arranged in the order of A layer / B layer / C layer / B layer are repeatedly laminated. In Figure 1(d), the reference numerals 9, 10, and 11 respectively represent the A layer (sometimes simply referred to as "A layer") 9 of the multilayer laminate film of the present invention, the B layer (sometimes simply referred to as "B layer") 10 of the multilayer laminate film of the present invention, and the C layer (sometimes simply referred to as "C layer") 11 of the multilayer laminate film of the present invention. As shown in Figure 1(d), the multilayer laminate film of the present invention preferably has a layer structure of (A layer / B layer / C layer / B layer)n / A layer (n is an integer) in which the A layer is arranged on both outermost surfaces. Since the same type of resin layer is arranged on both surfaces, this is particularly preferred from the viewpoints of facilitating film transport (especially when heated) by holding the film by rolls or clips at the film ends during film production, and preventing the film from curling when heat is applied to the film to cause it to shrink.

[0021] Conventional near-infrared reflective multilayer laminate film 1 transmits visible light incident from the front direction, reflects near-infrared light, and transmits P waves incident from oblique directions, while conventional P-wave reflective multilayer laminate film 2 transmits visible light incident from the front direction, transmits near-infrared light, and reflects P waves incident from oblique directions.

[0022] Therefore, when using these multilayer laminate films to produce a film that transmits visible light incident from the front direction, reflects near-infrared rays, and reflects oblique P waves, it is necessary to produce a laminate film 3 (hereinafter sometimes simply referred to as laminate film 3) by laminating a near-infrared-reflecting multilayer laminate film 1 and a P-wave-reflecting multilayer laminate film 2 using a transparent adhesive 12 or the like, as shown in Figure 1(c). Since the laminate film 3 has the properties of both the near-infrared-reflecting multilayer laminate film 1 and the P-wave-reflecting multilayer laminate film 2, it transmits visible light 13 incident from the front direction, reflects near-infrared rays 14, and reflects oblique P waves 15, as shown in Figure 1(c).

[0023] However, because the laminate film 3 is formed by laminating two types of multilayer laminate films, there are problems such as an increase in film thickness and differences in the thermal shrinkage properties of the two laminated multilayer laminate films. Due to these problems, when the laminate film 3 is applied to laminated glass, the laminate film 3 causes wrinkles and distortion in the laminated glass. Typically, in the lamination process for producing laminated glass using a multilayer laminate film, a laminate including glass and a multilayer laminate film is heated to improve adhesion between the glass and the multilayer laminate film and to allow the multilayer laminate film to conform to the curved surface of the glass. Therefore, the difference in the thermal shrinkage properties of the two types of multilayer laminate films that make up the laminate film 3 further exacerbates the degree of wrinkles and distortion.

[0024] On the other hand, as shown in FIG. 1(d), the multilayer laminate film 4 of the present invention has the function of transmitting visible light 13 incident from the front direction, reflecting near-infrared light 14, and reflecting oblique P-waves 15 with a single multilayer laminate film. Therefore, excessive thickness of the film can be prevented. Furthermore, since there are no multiple multilayer laminate films with different heat shrinkage properties, when the multilayer laminate film of the present invention is applied to laminated glass, the occurrence of wrinkles and distortion can be suppressed compared to when a laminate film 3 is used, and laminated glass with excellent appearance can be produced. When the laminate film 3 or the multilayer laminate film 4 of the present invention is applied to laminated glass, the laminate film 3 or the multilayer laminate film 4 of the present invention can be inserted into the laminated glass (FIG. 2(a)), or the laminate film 3 or the multilayer laminate film 4 of the present invention can be attached to the surface of the laminated glass (FIG. 2(b)).

[0025] 2 shows only an example of the multilayer laminate film 4 of the present invention, and illustrates an embodiment of laminated glass (having a multilayer laminate film between glass panes) 16 and laminated glass (having a multilayer laminate film on the surface) 17. In FIG. 2, the multilayer laminate film 4 is laminated to a transparent support (glass) 18 via an adhesive layer 19.

[0026] The mechanism by which the multilayer laminate film of the present invention is transparent and transmits visible light in the front direction, yet has the function of reflecting near-infrared rays and the function of reflecting P-wave visible light in an oblique direction will be described below.

[0027] The multilayer laminate film of the present invention has a dielectric constant X at a loss energy of 2.5 eV obtained by electron energy loss spectroscopy (EELS measurement). ｉ When the dielectric constant X ｉ (i indicates the layer. For example, X Ａ is the dielectric constant of layer A. Simply, the dielectric constant X or the dielectric constant X ｉ The film has a repeating unit structure in which three different resin layers (A layer, B layer, C layer) are arranged in the order of A layer / B layer / C layer / B layer, and the proportion of units in the repeating unit with a total layer thickness of 250 nm or more and 630 nm or less is 80% or more and 100% or less of all repeating units. Here, the repeating unit structure in which three different resin layers (A layer, B layer, C layer) are arranged in the order of A layer / B layer / C layer / B layer means a structure in which A layer, B layer, C layer, B layer are repeatedly present in the multilayer laminate film and are laminated in this order, as shown in Figure 1 (d). Also, ｉ "Difference in dielectric constant X" means that the dielectric constant X differs by 2% or more. ｉ The term "three types of resin layers having different dielectric constants X" refers to three types of resin layers having different dielectric constants X when compared in any combination. ｉ The difference in dielectric constant X causes reflection at the interface between the layers, and the reflection wavelength can be expressed by the following formula (A): The dielectric constant X can be measured by EELS measurement, and the measurement method will be described in detail later.

[0028]

[0029] where λ is the reflection wavelength, n Ａ is the in-plane refractive index of layer A, d Ａ is the thickness of layer A, n Ｂ is the in-plane refractive index of layer B, d Ｂ is the thickness of the B layer, n Ｃ is the in-plane refractive index of the C layer, d Ｃis the thickness of layer C, and the in-plane refractive index and thickness are values ​​in a repeating unit structure in which adjacent layers are arranged in the order of layer A / layer B / layer C / layer B. Here, the in-plane refractive index refers to the average value of the refractive index in the main orientation axis direction and the refractive index in the direction perpendicular to the main orientation axis direction in the film plane, and the definition and method of specifying the main orientation axis will be described later.

[0030] Furthermore, a method for forming a laminated structure having a repeating unit structure arranged in the order of Layer A / Layer B / Layer C / Layer B, in which units with a total layer thickness of 250 nm or more and 630 nm or less account for 80% or more of all repeating units, includes, for example, stacking extruded molten resin in a feed block in the desired layer structure and adjusting the slit width of the feed block and the discharge amount of each molten resin.

[0031] From formula (A), if the total layer thickness in the repeating unit is 250 nm or more, near-infrared rays with wavelengths of 850 nm or more can be reflected. On the other hand, if the total layer thickness in the repeating unit exceeds 630 nm, reflection occurs in the visible light region due to the influence of higher-order reflection described below, which is undesirable because it causes the multilayer laminate film of the present invention to have a reduced transparency or become discolored. Furthermore, if the total layer thickness in the repeating unit is less than 250 nm, the reflected wavelength will be less than 850 nm, and if the total layer thickness is 200 nm or less, the reflected wavelength will fall into the visible light region, which is undesirable because it causes the multilayer laminate film of the present invention to have a reduced transparency or become discolored.

[0032] Therefore, in order to achieve both transparency and heat-shielding properties, the multilayer laminate film of the present invention must contain 80% or more repeating units with a total layer thickness of 250 nm or more and 630 nm or less. Having 80% or more repeating units with a total layer thickness of 250 nm or more and 630 nm or less can reflect near-infrared light with wavelengths of 850 nm to 2000 nm while suppressing reflection of visible light. Therefore, when the multilayer laminate film of the present invention is used in window components for automobiles or buildings, it can reflect near-infrared energy from sunlight entering the interior of the vehicle or room, thereby suppressing temperature increases inside the vehicle or room, while ensuring external visibility. From this perspective, the proportion of repeating units with a total layer thickness of 250 nm or more and 630 nm or less to all repeating units is preferably 90% or more, more preferably 95% or more. Theoretically, the upper limit of this proportion is 100%.

[0033] The near-infrared reflectance of the multilayer laminate film of the present invention can be adjusted by adjusting the in-plane refractive index difference and the number of repeating units among the layers A, B, and C. More specifically, the near-infrared reflectance increases as the in-plane refractive index difference (the difference between the largest and smallest) among the layers A, B, and C increases and as the number of repeating units increases.

[0034] Even if the same resin is used in each layer and the number of repeating units is the same, the reflectance itself in a specific wavelength band will be higher in a configuration with a constant layer thickness than in a configuration with a layer thickness distribution. On the other hand, the reflection bandwidth will be wider in a configuration with a layer thickness distribution. Therefore, although a specific reflectance cannot be determined solely from the in-plane refractive index difference and the number of repeating units, from the viewpoint of ensuring a certain level of reflectance by adjusting the thickness distribution, etc., within a wide range of multilayer laminate film design, the in-plane refractive index difference between layers A and B and between layers B and C is preferably 0.03 or more, more preferably 0.07 or more, and even more preferably 0.10 or more. From the same viewpoint, the in-plane refractive index difference between layers A and C is preferably 0.06 or more, more preferably 0.14 or more, and even more preferably 0.20 or more.

[0035] Typically, the greater the number of repeating units in a multilayer laminate film, the higher the reflectivity can be achieved for light in a wider wavelength band. Therefore, by increasing the number of repeating units, a multilayer laminate film that reflects light in a desired wavelength band can be obtained. From this viewpoint, the number of repeating units is preferably 15 or more, more preferably 45 or more, even more preferably 90 or more, and particularly preferably 140 or more. Although there is no upper limit to the number of repeating units, as the number of repeating units increases, the manufacturing cost increases due to the larger manufacturing equipment, and the multilayer laminate film becomes thicker, resulting in poor handleability. Therefore, in reality, the practical range is about 2500, preferably 500, and more preferably 200. From the viewpoint of improving near-infrared reflectance, it is more preferable that the number of units in the multilayer laminate film of the present invention, in which the total layer thickness within the repeating units is 250 nm or more and 630 nm or less, is within the above-mentioned preferred range.

[0036] The layer thickness distribution of the multilayer laminate film of the present invention is preferably a constant layer thickness distribution from one side of the multilayer laminate film to the opposite side, a layer thickness distribution that increases or decreases from one side of the multilayer laminate film to the opposite side, a layer thickness distribution in which the layer thickness increases from one side of the multilayer laminate film toward the center of the film and then decreases, a layer thickness distribution in which the layer thickness decreases from one side of the multilayer laminate film toward the center of the film and then increases, or a combination of these distributions. The layer thickness distribution preferably changes in a continuous manner, such as linearly, geometrically, or with a difference progression, or in a manner in which approximately 12 to 52 layers have approximately the same layer thickness, or in which each layer has approximately the same repeat unit thickness and the layer thickness or repeat unit thickness changes in a stepwise manner.

[0037] Protective layers having a thickness of 1% or more of the total thickness of the multilayer laminate film can be preferably provided on both surface layers of the multilayer laminate film, and the thickness of each protective layer is preferably 4% or more of the total thickness of the multilayer laminate film. The protective layer may refer to the outermost layer on both surfaces of the multilayer laminate film, and can be provided from the perspective of protecting the multilayer laminate film. Increasing the thickness of the protective layer leads to the suppression of flow marks during film formation, improved accuracy of the actual layer thickness of each layer relative to the design, suppression of deformation of thin layers in the multilayer laminate film during the lamination process with other films or molded bodies and after the lamination process, and improved pressure resistance. The upper limit of the thickness of the protective layer is 20% or less of the total thickness of the film, from the perspective of ensuring the laminate components necessary for the expression of interference reflection while suppressing an increase in the thickness of the multilayer laminate film. The protective layer may be a single layer within a repeating unit, or may not be a single layer within a repeating unit. If it is considered to be a protective layer, it is not included when calculating the layer thickness ratio (A / B) of the A layer to the total thickness of the B layer of each repeat unit, and the layer thickness ratio (C / B) of the C layer to the total thickness of the B layer. Furthermore, a repeat unit including a layer considered to be a protective layer is not included when counting all repeat units.

[0038] The thickness of the multilayer laminate film of the present invention is not particularly limited, but is preferably 20 μm to 300 μm, for example. When the thickness is 20 μm or more, the multilayer laminate film has a strong stiffness, ensuring good handleability. When the thickness is 300 μm or less, the multilayer laminate film does not have excessive stiffness, improving formability. In other words, by setting the thickness within the above range, handleability and formability are improved, making it easier to conform to curved glass and the like when used as a projection image display member, etc.

[0039] In addition, functional layers such as a primer layer, a hard coat layer, an abrasion-resistant layer, a scratch-resistant layer, an anti-reflection layer, a color correction layer, an ultraviolet absorbing layer, a light stabilizing layer, a heat absorbing layer, a printing layer, a gas barrier layer, and an adhesive layer may be formed on at least one surface of the multilayer laminate film. These layers may be single-layer or multi-layer, and one layer may have multiple functions. In addition, the multilayer laminate film may contain additives such as ultraviolet absorbers, light stabilizers (HALS), heat absorbing agents, nucleating agents, and plasticizers. These components can also be used in combination as long as they do not impair the effects of the present invention.

[0040] In the second multilayer laminate film of the present invention, the ratio of repeating units in which the lamination ratio of A layer to the total thickness of B layer (A / B) and the lamination ratio of C layer to the total thickness of B layer (C / B) are 0.8 to 1.3 is 80% to 100% of all repeating units, and the dielectric constants X of the A layer, B layer, and C layer increase in this order. Ａ , the dielectric constant of layer B is X Ｂ , and the dielectric constant of the C layer is X Ｃ When this is done, X Ａ >X Ｂ >X Ｃ A / B and C / B can be calculated by observing a cross section parallel to the thickness direction of the multilayer laminate film with a transmission electron microscope (TEM) and measuring the thickness of each layer using its length measurement function (details of cross-sectional observation with a transmission electron microscope (TEM) will be described later).

[0041] Here, "in the repeating units, the repeating units having a stacking ratio (A / B) of 0.8 or more and a stacking ratio (C / B) of 1.3 or less are 80% or more and 100% or less of all the repeating units" means that the repeating units having a stacking ratio (A / B) of 0.8 or more and a stacking ratio (C / B) of 1.3 or less are 80% or more and 100% or less of all the repeating units. This can be interpreted in the same way as the preferred range described later. ｉ is larger in the order of A layer, B layer, and C layer" means that the dielectric constant X of A layerＡ is the dielectric constant of layer B, X Ｂ and the dielectric constant X of layer B is 2% or more larger than Ｂ is the dielectric constant of layer C, X Ｃ This also applies to the first multilayer laminate film of the present invention.

[0042] From a similar viewpoint, it is important that in the first multilayer laminate film of the present invention, the layers are arranged in descending order of dielectric constant X as layer A, layer B, and layer C. From a similar viewpoint, it is also preferable that in the first multilayer laminate film of the present invention, the repeating units in which the lamination ratio of layer A to the total thickness of layer B (A / B) and the lamination ratio of layer C to the total thickness of layer B (C / B) are 0.8 to 1.3, respectively, account for 80% to 100% of all repeating units. The same applies to the preferred ranges described below.

[0043] In the case of the multilayer laminate film of the present invention, the reflection wavelength is determined based on the above-described formula (A), while in the case of a multilayer laminate film in which layers made of two different types of thermoplastic resins are alternately laminated as in Patent Document 3, the reflection wavelength is determined based on formula (B). In a multilayer laminate film, not only this reflection wavelength (first-order reflection) occurs, but also reflections of 1 / n wavelength, such as reflections at 1 / 2 wavelength (second-order reflection), 1 / 3 wavelength (third-order reflection), 1 / 4 wavelength (fourth-order reflection), 1 / 5 wavelength (fifth-order reflection), ... 1 / n wavelength reflection (n-order reflection) (n is an integer).

[0044]

[0045] where λ is the reflection wavelength, n Ａ is the in-plane refractive index of layer A, d Ａ is the thickness of layer A, n Ｂ is the in-plane refractive index of layer B, d Ｂ is the thickness of the B layer.

[0046] Generally, multilayer laminate films reflect 1 / n wavelength. Therefore, if a multilayer laminate film is designed to reflect near-infrared light with a wavelength of 1000 nm, for example, it will also reflect visible light at 500 nm, which is 1 / 2 of that wavelength, which can result in reduced transparency and discoloration. To address this issue, Patent Document 3 suppresses reflection at 1 / 2 wavelength by setting the thickness ratio of adjacent A layers to B layers in the range of 0.9 to 1.1. However, the method described in Patent Document 3 can only suppress reflection up to 1 / 2 wavelength, so when near-infrared light of 1200 nm or longer is reflected, 1 / 3 of the wavelength becomes 400 nm or longer, which is visible light, resulting in reduced transparency and discoloration of the multilayer laminate film. Therefore, there is a limit to how much the near-infrared reflection band can be expanded while maintaining high transmittance and transparency in the visible light region.

[0047] In contrast, the multilayer laminate film of the present invention has a repeating unit structure in which three types of resin layers (A layer, B layer, C layer) with different dielectric constants X are arranged in the order A layer / B layer / C layer / B layer, and within the repeating units, the ratio of A layer to the total thickness of B layer (A / B) and the ratio of C layer to the total thickness of B layer (C / B) are 0.8 to 1.3, respectively, and 80% to 100% of all repeating units are repeating units, and the dielectric constants X increase in the order A layer, B layer, and C layer, thereby suppressing reflection over a wide wavelength range from 1 / 2 wavelength to 1 / 4 wavelength. In this way, the multilayer laminate film of the present invention can suppress reflection up to 1 / 4 wavelength, and therefore can reflect near-infrared light up to a wavelength of 2000 nm (the 1 / 5 wavelength at which reflection occurs is 400 nm, which does not affect the transparency of visible light), while reducing deterioration of transparency and coloration.

[0048] When the lamination ratio (A / B) and the lamination ratio (C / B) are each 0.8 or more and 1.3 or less, the phases of the wavelengths from 1 / 2 wavelength to 1 / 4 wavelength reflected at the interfaces between each layer in the repeating unit structure become opposite phases, causing a cancellation effect and suppressing high-order reflections. Furthermore, when the dielectric constant X increases in the order of A layer, B layer, and C layer, the amplitudes of the wavelengths from 1 / 2 wavelength to 1 / 4 wavelength reflected at the interfaces between each layer become the same, thereby strengthening the cancellation effect.

[0049] The reflectance of the half wavelength to quarter wavelength cannot be determined uniquely by the lamination ratio (A / B) and lamination ratio (C / B) alone because it is affected not only by the lamination ratio (A / B) and lamination ratio (C / B) but also by the refractive index difference between the A, B, and C layers of the multilayer laminate film, the number of repeat units, and the layer thickness distribution. However, by bringing the phases of the half wavelength to quarter wavelength reflected at the interfaces between each layer in the repeat unit structure closer to opposite phases to enhance the cancellation effect, deterioration of transparency and coloration can be reduced. From the above viewpoints, in the multilayer laminate film of the present invention, within a wide range of multilayer laminate film design, it is more preferable that the lamination ratio (A / B) be 0.8 to 1.1 and the lamination ratio (C / B) be 0.9 to 1.2. That is, it is more preferable that the repeat units having a lamination ratio (A / B) of 0.8 to 1.1 and a lamination ratio (C / B) of 0.9 to 1.2 account for 80% to 100% of all repeat units.

[0050] By setting the lamination ratio (A / B) and lamination ratio (C / B) to 0.8 or more and 1.3 or less, or within the above-mentioned preferred range, high-order reflection occurring in the visible light band can be suppressed, thereby achieving high transmittance and transparency of visible light. From the above-mentioned viewpoint, for each of the lamination ratio (A / B) and lamination ratio (C / B), the proportion of repeat units having a lamination ratio of 0.8 or more and 1.3 or less, or within the above-mentioned preferred range, to all repeat units is preferably 90% or more, more preferably 95% or more. Note that the upper limit of this proportion is theoretically 100%.

[0051] The fact that the dielectric constant X increases in the order of the A layer, the B layer, and the C layer means that the in-plane refractive index increases in the order of the A layer, the B layer, and the C layer. Preferably, when the in-plane refractive indexes of the A layer, the B layer, and the C layer are Na, Nb, and Nc, respectively, Nb satisfies the following condition: (Na×Nc) １／２ × 0.99 ≦ Nb ≦ (Na × Nc) １／２ × 1.01, and most preferably Nb = (Na × Nc) １／２ When Nb has the above value, the effect of canceling reflections of wavelengths from 1 / 2 wavelength to 1 / 4 wavelength can be strengthened, and the multilayer laminate film has both high near-infrared reflectivity and high colorless transparency when viewed from the front.

[0052] As described above, the second multilayer laminate film of the present invention has a repeating unit structure in which three types of resin layers (A layer, B layer, C layer) having different dielectric constants X are arranged in the order A layer / B layer / C layer / B layer, and the proportion of units within the repeating units having a total layer thickness of 250 nm or more and 630 nm or less accounts for 80% or more and 100% or less of all repeating units, and the proportion of repeating units within the repeating units having a stacking ratio (A / B) and a stacking ratio (C / B) of 0.8 or more and 1.3 or less accounts for 80% or more and 100% or less of all repeating units, and the dielectric constant X of the A layer increases in the order of the B layer and the C layer. This multilayer laminate film configuration can achieve both high transmittance and transparency for visible light while reflecting near-infrared light in the wavelength range of 850 nm to 2000 nm.

[0053] Furthermore, the second multilayer laminate film of the present invention must have an average visible light reflectance of 10% or more and 99% or less for P waves incident at an angle of 60° relative to the normal to the film surface. This requirement is preferably also satisfied by the first laminate film of the present invention, and the same applies to the preferred range described below. Hereinafter, the angle between the normal to the film surface and the incident light may be referred to as the angle of incidence. This P wave reflectance (%) can be measured by measuring the reflectance of P waves in the wavelength range of 400 to 700 nm at an incident angle θ = 60° using a spectrophotometer in 1 nm increments and calculating the average value.

[0054] In the case of typical transparent substrates such as transparent glass or transparent resin films, as the incident angle relative to the normal to the film surface gradually increases from 20°, the reflectance of P waves, a type of polarized light, decreases, reaching 0% at an angle known as the Brewster angle. In other words, it is difficult for typical transparent substrates to transmit P waves from the front direction while reflecting P waves from oblique directions. On the other hand, from the perspective of improving image display performance, the average reflectance of P waves with wavelengths of 400 nm to 700 nm incident at an incident angle of 60° is preferably high, preferably 20% or more, and more preferably 25% or more. There is no particular upper limit to the average reflectance of P waves with wavelengths of 400 nm to 700 nm incident at an incident angle of 60°, but from the perspective of feasibility, it is set to 99%. Furthermore, when transmitting the background and superimposing the image on it, the average reflectance is preferably 50% or less.

[0055] P waves and S waves can be defined as follows. When electromagnetic waves (light) are incident on the front surface of an object from an oblique direction, P waves are electromagnetic waves whose electric field component is parallel to the plane of incidence (linearly polarized light oscillating parallel to the plane of incidence), and S waves are electromagnetic waves whose electric field component is perpendicular to the plane of incidence (linearly polarized light oscillating perpendicular to the plane of incidence). The reflection characteristics of P waves and S waves will be explained with reference to the drawings. Graphs (examples) showing the angle dependence of the average reflectance of a conventional transparent resin film (a typical transparent support) in FIG. 3A, a conventional light-reflecting multilayer laminate film in FIG. 3B, a conventional multilayer laminate film that transmits visible light and reflects near-infrared light in FIG. 3C, and a multilayer laminate film of the present invention in FIG. 3D are shown for the multilayer laminate film of the present invention. The graphs show the angle dependence of the average reflectance of a conventional transparent resin film (a typical transparent support) in FIG. 3A, a conventional light-reflecting multilayer laminate film in FIG. 3C, a conventional light-transmitting multilayer laminate film that transmits visible light and reflects near-infrared light, and a multilayer laminate film of the present invention. In FIG. 3, reference numerals 20 and 21 respectively represent the reflectance 20 of P waves and the reflectance 21 of S waves.

[0056] As shown in Figure 3(a), a typical transparent support follows the Fresnel equation, and the reflectance of P waves decreases with increasing incident angle, reaching 0%, and then increases again. On the other hand, the reflectance of S waves increases with increasing incident angle. As shown in Figure 3(b), a conventional light-reflecting multilayer laminate film has a constant reflectance for both P waves and S waves at an incident angle of 0°, resulting in low transmittance. Furthermore, the reflectance of both P waves and S waves increases with increasing incident angle. As shown in Figure 3(c), a conventional multilayer laminate film that transmits visible light and reflects near-infrared light, like a typical transparent support, shows a tendency for the reflectance of P waves to decrease with increasing incident angle, reaching a value close to 0%, and then increasing again. On the other hand, the reflectance of S waves increases with increasing incident angle. As shown in Figure 3(d), the multilayer laminate film of the present invention has the characteristic that the reflectance of both P waves and S waves is low (transmittance is high) at an incident angle of 0°, and the reflectance of both P waves and S waves increases with increasing incident angle. By using a multilayer laminate film having such optical properties, for example, as a projection image display member, it is possible to obtain good visibility of the background when observing the background through the projection image display member from a direction perpendicular to the surface of the projection image display member, and good displayability of the projected image when a P-wave image is projected onto the surface of the projection image display member.

[0057] The principle by which the multilayer laminate film of the present invention reflects P waves from an oblique direction while maintaining high transmittance and transparency for visible light from the front direction will be explained. The multilayer laminate film of the present invention reflects near-infrared rays over a wide wavelength range while suppressing reflection of wavelengths ranging from 1 / 2 to 1 / 4 of the near-infrared reflection wavelength. Here, the in-plane refractive index Nb of layer B is expressed as Nb = (Na x Nc). １／２ In the multilayer laminate film of the present invention, the in-plane refractive index Nb of the layer B in the front direction is set to Nb = (Na × Nc) １／２ However, in the oblique direction, the refractive index of the B layer in the oblique direction Nbθ≠(Naθ×Ncθ) １／２ The design is as follows.

[0058] Here, Naθ, Nbθ, and Ncθ are the refractive indices of the A layer, B layer, and C layer, respectively, for light with a wavelength of 633 nm that enters the multilayer laminate film from the air at an incident angle θ (°). In the multilayer laminate film of the present invention, the refractive index of the B layer in the oblique direction is such that Nbθ ≠ (Naθ × Ncθ). １／２ Therefore, the canceling effect of reflections of 1 / 2 wavelength to 1 / 4 wavelength is weakened in oblique directions. Note that this weakening of the canceling effect of reflections in oblique directions only affects P waves, not S waves. Therefore, the multilayer laminate film of the present invention reflects P waves of 1 / 2 wavelength to 1 / 4 wavelength, which are in the visible light range, in oblique directions, so that the average visible light reflectance of P waves when incident at an angle of 60° with respect to the normal to the film surface can be made 10% or more. Note that, although transparency in oblique directions is slightly lost due to reflection of P waves in oblique directions, a film with sufficiently high transparency in the front direction (incident angle 0°) can be obtained.

[0059] As described above, the multilayer laminate film of the present invention has a unit structure in which layers A / B / C / B are arranged in this order. By controlling the layer thickness, lamination ratio, and refractive index within this unit structure within the above-mentioned ranges, a single multilayer laminate film can be transparent, transmitting visible light in the front direction, while also having the ability to reflect near-infrared light and reflect P-wave visible light in oblique directions. The multilayer laminate film of the present invention has particularly remarkable effects in that it can achieve functions that, in conventional technology, would have to be achieved by laminating two types of multilayer laminate films together. Laminates of two types of multilayer laminate films usually have problems such as wrinkling during processing at high temperatures due to differences in the heat shrinkage properties of the multilayer laminate films. The multilayer laminate film of the present invention also has the advantage of eliminating such problems.

[0060] From the viewpoint of achieving an average visible light reflectance of 10% or more for P waves incident at an angle of 60° relative to the normal to the film surface, it is preferable that the second multilayer laminate film of the present invention has layers A, B, and C each composed of a combination of crystalline / amorphous / amorphous thermoplastic resin layers. For the reasons described above, the first multilayer laminate film of the present invention must have layers A, B, and C each composed of a combination of crystalline / amorphous / amorphous thermoplastic resin layers. Here, "layers A, B, and C each composed of a combination of crystalline / amorphous / amorphous thermoplastic resin layers" means that layer A is primarily composed of a crystalline thermoplastic resin and layers B and C are primarily composed of an amorphous thermoplastic resin, and the term "main component" refers to a component that accounts for 80% by mass or more and 100% by mass or less when all components constituting the layers are taken as 100% by mass. Further, the term "crystalline" as used herein refers to a melting enthalpy (ΔHm) of 5 J / g or more measured according to JIS-K-7122 (2012), and "amorphous" refers to a melting enthalpy (ΔHm) of less than 5 J / g. The stronger the amorphousness, the more the decrease in the refractive index perpendicular to the plane can be suppressed, so the melting enthalpy (ΔHm) is more preferably less than 3 J / g, and even more preferably less than 1 J / g, or a melting curve (melting enthalpy curve) or melting point (Tm) is not observed.

[0061] The effect of forming a multilayer laminate film in this manner will be described below with reference to Fig. 4. Fig. 4 shows the refractive index versus the angle of incidence of P-wave light incident on the A layer, B layer, and C layer of the multilayer laminate films of Example 1 and Comparative Example 1 (both described below), and reference numerals 22 to 25 in Fig. 4 respectively represent the refractive index (Naθ) of the A layer at an incident angle θ, the refractive index (Ncθ) of the C layer at an incident angle θ, the refractive index (Nbθ) of the B layer of the multilayer laminate film of the present invention (Example 1) at an incident angle θ, and the refractive index (Nbθ) of the B layer of the conventional near-infrared reflective multilayer laminate film (Comparative Example 1) at an incident angle θ.

[0062] The thermoplastic resin used in the A layer is crystalline, and has a lower refractive index in the perpendicular direction than in the in-plane direction. Therefore, the refractive index decreases as the incident angle increases. The thermoplastic resin used in the C layer is amorphous, and has the same refractive index in the in-plane direction and perpendicular direction. Therefore, the refractive index does not change even if the incident angle changes. The B layer used in Example 1 and Comparative Example 1 has the same refractive index in the front direction (incident angle 0°, in-plane direction), and Nb ≒ (Na × Nc) １／２ Since the value of , the effect of canceling out reflections of 1 / 2 wavelength to 1 / 4 wavelength is strong, and the multilayer laminated film exhibits high transmittance for visible light incident from the front direction, and therefore has excellent transparency.

[0063] The thermoplastic resin of the layer B used in Comparative Example 1 is crystalline, and the refractive index is different between the in-plane direction and the direction perpendicular to the plane. Therefore, as shown in Figure 4, the refractive index decreases as the incident angle of light increases, and even in the oblique direction, Nbθ ≒ (Naθ × Ncθ) １／２ Therefore, no reflection occurs in visible light. On the other hand, the thermoplastic resin of Layer B used in Example 1, which is the multilayer laminate film of the present invention, is amorphous, and the refractive index in the in-plane direction and the direction perpendicular to the plane is almost the same. Therefore, even if the incident angle changes, the refractive index does not change, and as shown in Figure 4, in the oblique direction, Nbθ ≠ (Naθ × Ncθ) １／２ Since the reflectance value is 1 / 2 to 1 / 4 wavelength, reflection of P waves occurs, making it possible to make the average visible light reflectance when incident at an angle of 60° with respect to the normal to the film surface 10% or more. Furthermore, since the average visible light reflectance when incident at an angle of 60° with respect to the normal to the film surface is also affected by the number of repeating units, if the resin composition of each layer is the same, the average visible light reflectance can be increased by increasing the number of repeating units.

[0064] Furthermore, the difference in the average visible light reflectance of P waves due to the difference in the refractive index of the B layer described above will be explained using Figure 5. In Figure 5, reference numeral 26 represents the average visible light reflectance of P waves for the multilayer laminate film of the present invention (Example 1), and reference numeral 27 represents the average visible light reflectance of P waves for the near-infrared reflective multilayer laminate film of the prior art (Comparative Example 1). For the prior art (Comparative Example 1), the average visible light reflectance 27 of P waves decreases as the incident angle increases from 0° to 50°, and tends to increase from an incident angle of 60°. However, at an incident angle of 60°, the average visible light reflectance 26 of P waves is low enough to adequately display P wave images. On the other hand, for the multilayer laminate film of the present invention, the average visible light reflectance 26 of P waves decreases very slightly as the incident angle increases from 0° to 20°, but tends to increase from an incident angle of 20° onward, and at an incident angle of 60°, the average visible light reflectance 26 of P waves tends to increase enough to adequately display P wave images. As described above, by configuring each of the A layer, B layer, and C layer with a combination of crystalline / amorphous / amorphous thermoplastic resin layers, it becomes easy to achieve an average visible light reflectance of 10% or more for P waves when incident at an incident angle of 60° with respect to the normal to the film surface.

[0065] Another preferred embodiment of the multilayer laminate film of the present invention in which the average visible light reflectance of P waves when incident at an angle of 60° to the normal to the film surface is 10% or more is that the plane orientation coefficient of layer A is 0.06 or more and the dielectric constant X Ｂ In the above, an embodiment is one in which the ratio of the dielectric constant in the in-plane direction to the dielectric constant in the perpendicular direction is 10% or less. The ratio of the dielectric constant in the in-plane direction to the dielectric constant in the perpendicular direction is the ratio (%) obtained by dividing the difference between the dielectric constant in the in-plane direction and the dielectric constant in the perpendicular direction by the dielectric constant in the perpendicular direction. The effect of adopting this embodiment will be explained below with reference to FIG. 4. The plane orientation coefficient is defined as (in-plane refractive index) - (perpendicular refractive index), and represents the difference in refractive index between the in-plane direction and the perpendicular direction. By making the plane orientation coefficient of layer A 0.06 or more, it is possible to increase the change in refractive index between an incident angle of 0° and an oblique direction, as shown in 22 in FIG. 4. The relationship between the refractive index n and the dielectric constant X is expressed as "n = (X / X ０ ×μ / μ ０ ) １／２ " where X ０ is the permittivity of a vacuum, μ is the magnetic permeability, μ ０ is the permeability of a vacuum, μ / μ０ can be considered as 1 in the visible to near infrared range for a wide range of resins. ０ ) １／２ " and the ratio of the dielectric constants in the in-plane direction and the perpendicular direction of the B layer can be considered to correlate with the ratio of the refractive indexes.

[0066] Dielectric constant X of layer B Ｂ In the above, the ratio of the dielectric constant in the in-plane direction to the dielectric constant in the perpendicular direction is 10% or less, which means that the difference in refractive index between the in-plane direction and the perpendicular direction of the B layer is small, and the ratio between Nbθ and (Naθ × Ncθ) １／２ From the viewpoint of increasing the average visible light reflectance of P waves incident at an angle of 60° to the normal to the film surface, the plane orientation coefficient of the A layer is more preferably 0.12 or more, and even more preferably 0.18 or more, and the dielectric constant X of the B layer is Ｂ In the dielectric constant X of layer B, the ratio of the dielectric constant in the in-plane direction to the dielectric constant perpendicular to the plane is more preferably 5% or less, and even more preferably the ratio of the dielectric constant in the in-plane direction to the dielectric constant perpendicular to the plane is 3% or less.

[0067] The planar orientation coefficient of Layer A means the planar orientation coefficient of Layer A measured at a wavelength of 633 nm, and the measurement method will be described later. The ratio of the dielectric constants in the in-plane direction to the perpendicular direction of Layer B can be measured by electron energy loss spectroscopy (EELS measurement), and the measurement method will be described later in detail.

[0068] Furthermore, as a method for making the plane orientation coefficient of Layer A of a multilayer laminate film 0.06 or more and making the ratio of the dielectric constants in the in-plane direction and the plane-perpendicular direction in the dielectric constant X of Layer B 10% or less, a method of using a crystalline resin for Layer A and stretching it at least twice in at least one direction at a temperature equal to or higher than its glass transition temperature is preferred, and a method of stretching it at least 3.0 times in both one direction and the direction perpendicular to that direction in the film plane is more preferred. In this case, it is preferable to use an amorphous resin for Layer B or to perform heat treatment at a temperature equal to or higher than the melting point of Layer B in the heat treatment step of film formation. In particular, it is more preferable to use an amorphous resin from the viewpoint of being able to freely select the heat treatment temperature.

[0069] The resin layers used in the multilayer laminate film of the present invention are preferably thermoplastic resins. Examples of thermoplastic resins include linear polyolefins such as polyethylene, polypropylene, poly(4-methylpentene-1), and polyacetal, alicyclic polyolefins which are ring-opening metathesis polymers of norbornenes, addition polymers, and addition copolymers with other olefins, biodegradable polymers such as polylactic acid and polybutyl succinate, polyamides such as nylon 6, nylon 11, nylon 12, and nylon 66, aramid, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, ethylene-vinyl acetate copolymer, polyacetal, and polyglycol. Examples of the polymer that can be used include polystyrene, styrene copolymerized polymethyl methacrylate, polycarbonate, polyesters such as polypropylene terephthalate, polyethylene terephthalate, polybutylene terephthalate, and polyethylene-2,6-naphthalate, polyethersulfone, polyetheretherketone, modified polyphenylene ether, polyphenylene sulfide, polyetherimide, polyimide, polyarylate, tetrafluoroethylene resin, trifluoroethylene resin, trifluorochloroethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer, and polyvinylidene fluoride.

[0070] Among these, polyester and polymethyl methacrylate are particularly preferred from the viewpoints of strength, heat resistance, transparency, refractive index difference, and versatility. These may be copolymers or mixtures of two or more resins.

[0071] Polyester refers to a resin having a molecular structure in which dicarboxylic acid units and diol units are linked by ester bonds. The polyester is preferably a polyester whose main constituent units are aromatic dicarboxylic acid units or aliphatic dicarboxylic acid units and diol units. Here, the main constituent unit refers to a dicarboxylic acid unit that accounts for more than 50 mol% but not more than 100 mol% of the total dicarboxylic acid units constituting the polyester, taking the total dicarboxylic acid units constituting the polyester as 100 mol%, and the same can be said for the main constituent unit of a diol unit.

[0072] Examples of aromatic dicarboxylic acids constituting the polyester include terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, and 4,4'-diphenylsulfonedicarboxylic acid. Examples of aliphatic dicarboxylic acids include adipic acid, suberic acid, sebacic acid, dimer acid, dodecanedioic acid, cyclohexanedicarboxylic acid, and their ester derivatives. Among these, terephthalic acid and 2,6-naphthalenedicarboxylic acid are preferred, as they exhibit high refractive indices. These acid components may be used alone or in combination, and may also be partially copolymerized with hydroxy acids such as hydroxybenzoic acid.

[0073] Examples of diol components include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, 2,2-bis(4-hydroxyethoxyphenyl)propane, isosorbate, and spiroglycol. Of these, polyalkylene glycol and ethylene glycol are preferred. These diol components may be used alone or in combination of two or more.

[0074] The thermoplastic resin that is the main component of each layer of the multilayer laminate film of the present invention is preferably selected from, for example, polyethylene terephthalate and polymers thereof, polyethylene naphthalate and copolymers thereof, polybutylene terephthalate and copolymers thereof, polybutylene naphthalate and copolymers thereof, polyhexamethylene terephthalate and copolymers thereof, polyhexamethylene naphthalate and copolymers thereof, and polymethyl methacrylate and copolymers thereof, among the above polyesters.

[0075] Furthermore, various additives such as antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic fine particles, fillers, antistatic agents, and nucleating agents can be added to the thermoplastic resin either alone or in combination to the extent that the properties of the resin are not deteriorated.

[0076] The multilayer laminate film of the present invention preferably has a saturation of 10 or less for transmitted light incident perpendicularly to the film surface. To achieve a saturation of 10 or less for transmitted light incident perpendicularly to the film surface, it is effective to strengthen the cancellation of reflections at wavelengths from 1 / 2 wavelength to 1 / 4 wavelength and to achieve uniform reflection over the entire near-infrared reflection wavelength range. To strengthen the cancellation of reflections at wavelengths from 1 / 2 wavelength to 1 / 4 wavelength, as described above, the lamination ratio (A / B) should be 0.8 or more and 1.3 or less (preferably 0.8 or more and 1.1 or less), the lamination ratio (C / B) should be 0.8 or more and 1.3 or less (preferably 0.9 or more and 1.2 or less), and when the in-plane refractive indices of the A layer, B layer, and C layer are Na, Nb, and Nc, respectively, Nc should be (Na × Nc) １／２ × 0.99 ≦ Nb ≦ (Na × Nc) １／２ It is also effective to set the ratio of repeat units having a total layer thickness of 250 nm or more and 630 nm or less to 80% or more of all repeat units, or to fall within the above-mentioned preferable range, since this leads to preventing first-order reflection and higher-order reflection from occurring within the visible light band.

[0077] By having a saturation of 10 or less for transmitted light incident perpendicularly to the film surface, coloring when viewing a background through the multilayer laminate film of the present invention can be suppressed, thereby improving the visibility of the background. The saturation of transmitted light can be calculated by calculating the tristimulus values ​​X, Y, and Z of the CIE 1931 color system and the tristimulus values ​​Xn, Yn, and Zn of specific white light according to JIS-Z-8781-3 (2016), determining a* and b* in the CIE 1976 L*a*b* color space from the obtained X, Y, Z and Xn, Yn, and Zn according to JIS-Z-8781-4 (2013), and then calculating the square root of the sum of the squares of a* and b*.

[0078] The multilayer laminate film of the present invention preferably has a transmittance of 70% or more and 100% or less for visible light incident perpendicularly to the film surface. Here, "a transmittance of 70% or more and 100% or less for visible light incident perpendicularly to the film surface (meaning an angle of 0° relative to the normal to the multilayer laminate film surface)" specifically refers to an average transmittance of 70% or more and 100% or less for light with wavelengths of 400 to 700 nm incident perpendicularly to the multilayer laminate film of the present invention. The visible light referred to here does not refer to the aforementioned P-wave visible light, but includes P-wave and S-wave light. Such high transmittance for light in the visible light region of 400 to 700 nm wavelengths provides transparency comparable to that of transparent glass or transparent resin films, enabling good visibility of the background when observed through the multilayer laminate film from a direction perpendicular to the film surface. From the above perspectives, the transmittance is preferably 80% or more, more preferably 90% or more. A transmittance of 90% or more allows users to view the background without noticing the presence of the multilayer laminate film. From the perspective of ease of implementation, the upper limit of the transmittance is preferably 99%.

[0079] The transmittance of light incident perpendicularly to the surface of the multilayer laminate film can be measured by measuring the transmittance of light with a wavelength of 400 to 700 nm at an incident angle θ = 0° using a spectrophotometer in 1 nm increments and calculating the average value.

[0080] A method for achieving a transmittance of 70% to 100% for visible light incident perpendicularly to the film surface of the multilayer laminate film of the present invention will be described. By configuring the multilayer laminate film of the present invention to have 80% or more of all repeating units in which the total layer thickness within the repeating units is 250 nm to 630 nm, it is possible to reflect only near-infrared light (primary reflection). Furthermore, by configuring the repeating units to have 80% or more of all repeating units in which the stacking ratio of the A layer to the total thickness of the B layer (A / B) and the stacking ratio of the C layer to the total thickness of the B layer (C / B) are 0.8 to 1.3, respectively, and by configuring the repeating units in such a manner that the dielectric constants X of the A layer, B layer, and C layer increase in this order, it is possible to cancel reflections at wavelengths ranging from 1 / 2 wavelength to 1 / 4 wavelength of the primary reflection wavelength. This configuration makes it easy to achieve a transmittance of 70% to 100% for visible light incident perpendicularly to the film surface.

[0081] The multilayer laminate film of the present invention preferably has a reflectance of 40% or more over at least 100 nm in the wavelength range of 850 nm to 1600 nm when light is incident on the film surface at an angle of 10° with respect to the normal. By having a reflectance of 40% or more over at least 100 nm in the wavelength range of 850 nm to 1600 nm, when the multilayer laminate film of the present invention is used in window components for automobiles or buildings, it is possible to reflect near-infrared energy from sunlight entering the interior of the vehicle or room, thereby suppressing temperature increases inside the vehicle or room. From the viewpoint of enhancing the effect of suppressing temperature increases inside the vehicle or room, it is more preferable that the reflectance be 40% or more over at least 600 nm in the wavelength range of 850 nm to 1600 nm. The reflectance at each wavelength can be measured using a known spectrophotometer.

[0082] A method for achieving a reflectance of 40% or more over at least a wavelength of 100 nm in the wavelength range of 850 nm to 1600 nm includes an embodiment in which the number of repeating units in which the total layer thickness within the repeating units is 250 nm or more and 630 nm or less is 15 or more, and the in-plane refractive index difference between the A layer and the B layer and between the B layer and the C layer is 0.03 or more. From the viewpoint of increasing the reflectance with a small number of repeating units, the in-plane refractive index difference between the A layer and the B layer and the B layer and the C layer is both 0.07 or more, and more preferably both 0.10 or more. From the same viewpoint, the in-plane refractive index difference between the A layer and the C layer is preferably 0.06 or more, more preferably 0.14 or more, and even more preferably 0.20 or more.

[0083] The multilayer laminate film of the present invention preferably satisfies the relationship Rp20≦Rp40<Rp60, where Rp20(%), Rp40(%), and Rp60(%) are the average reflectances when P waves in the visible light band are incident on the film surface at angles of 20°, 40°, and 60° relative to the normal to the film surface. This embodiment does not have an angle equivalent to the Brewster angle. Therefore, by configuring the multilayer laminate film of the present invention in this manner, it is easy to relatively increase the reflectance of P waves incident from an oblique direction relative to the reflectance of P waves incident from the front of the multilayer laminate film of the present invention. Therefore, when a light source emitting P waves is used to project an image, the image can be displayed more clearly. The average reflectance of P waves in the wavelength range of 400 to 700 nm can be measured by measuring the reflectance of P waves in that range in 1-nm increments using a spectrophotometer and calculating the average value (details of the measurement method will be described later).

[0084] In order to satisfy the relationship Rp20≦Rp40<Rp60, it is effective to configure each of the A layer, B layer, and C layer with a combination of crystalline / amorphous / amorphous thermoplastic resin layers, to set the number of repeating units to 90 or more, and to adopt an embodiment in which the plane orientation coefficient of the A layer is 0.18 or more and the ratio of the dielectric constant in the in-plane direction to the dielectric constant in the perpendicular direction in the dielectric constant X of the B layer is 10% or less. These methods can be combined as appropriate. By using the above-mentioned method, as shown in Figure 4, as the incident angle increases from 0° to the oblique direction, Nbθ and (Naθ × Ncθ) １／２ That is, as the incident angle increases from 0° to the oblique direction, the reflection of P waves of 1 / 2 wavelength to 1 / 4 wavelength becomes stronger, and it becomes easier to satisfy Rp20≦Rp40<Rp60.

[0085] In the multilayer laminate film of the present invention, the saturation of reflected light of P waves incident at an angle of 60° relative to the normal to the film surface is preferably 20 or less, more preferably 5 or less. Hereinafter, the "saturation of reflected light of P waves when incident at an angle of 60° relative to the normal to the multilayer laminate film surface" may be referred to as the "saturation of reflected light of P waves." A saturation of reflected light of P waves of 20 or less means that uniform reflection is achieved across the entire wavelength range of visible light, and such an embodiment can suppress coloring due to reflected light. Therefore, when the multilayer laminate film is used as a projection component such as a projection image display device, the color of the projected image displayed when projected using P waves is reproduced as approximately the same color as the image illuminated from the display.

[0086] An example of a method for reducing the saturation of reflected P-wave light to 20 or less will be described with reference to FIG. 6 . FIG. 6 shows an example of an ideal layer thickness distribution of layers A, B, and C, from layer position 1 on the film surface to layer position 601 on the opposite film surface, with reference numerals 28 to 30 representing the thicknesses of layers A, C, and B, respectively. By uniformly arranging layers A, B, and C that reflect light in the wavelength range of 850 nm to 1750 nm in accordance with formula (A) as shown in FIG. 6 , the standard deviation of reflectance in that wavelength range can be reduced to 10% or less, and the standard deviation of reflectance in each wavelength band from 1 / 2 wavelength to 1 / 4 wavelength of that wavelength band, which is the reflection band for visible light, can also be reduced to 10% or less. As a result, it becomes easy to reduce the saturation of reflected P-wave light to 20 or less.

[0087] In the production of multilayer laminate films, deviations from the ideal layer thickness, as shown in Figure 6, occur due to factors such as the design accuracy of the equipment and the operational stability of the film production equipment. However, if the deviations at each layer position from layer position 1 to layer position 601 are averaged within approximately ±10%, the saturation of reflected P-wave light can be reduced to 20 or less. Here, a method for suppressing thickness deviations is described. A multilayer laminate structure can be obtained by melting each of three thermoplastic resins, laminating multiple repeat units arranged in the order of Layer A / Layer B / Layer C / Layer B using a lamination device, and melt-extruding the resulting molten laminate into a sheet using a T-shaped die or the like. Suppressing layer disorder in this molten laminate leads to suppression of thickness deviations. One method for suppressing thickness deviations is to provide a thick outermost layer in the molten laminate. The thickness of this outermost layer is preferably 1% or more, more preferably 4% or more, of the total thickness of the molten laminate. It is also more preferable to thicken both outermost layers, rather than just one.

[0088] Furthermore, in order to achieve a saturation of reflected P waves of 20 or less and uniform reflection across the entire wavelength range of visible light, it is also preferable that the wavelength range in which the reflectance is 40% or more when light is incident on the film surface at an angle of 10° with respect to the normal to the film surface includes at least the range of 850 nm to 1600 nm. Since the reflected wavelength of P waves incident at an angle of 60° with respect to the normal to the film surface is in the range of 1 / 2 wavelength to 1 / 4 wavelength of the primary reflection wavelength, if the primary reflection wavelength band is narrow, the reflection band from 1 / 2 wavelength to 1 / 4 wavelength will also be narrow, resulting in only a portion of the wavelengths in the visible light range being reflected, and the saturation of reflected P waves will be high.

[0089] The multilayer laminate film of the present invention preferably has an azimuthal variation of Rp60 of 10% or less, where Rp60 (%) is the average reflectance when P-wave radiation in the visible light band is incident on the film surface at an angle of 60° relative to the normal. Here, the azimuthal angle refers to each azimuthal angle (0°, 45°, 90°, 135°, 180°) in the plane of the film surface of the multilayer laminate film 4 constituting the laminate of the present invention, when the azimuthal angle in the direction of the main orientation axis is 0°, as shown in FIG. 7 . The main orientation axis direction refers to the direction with the highest degree of orientation in the film plane. The degree of orientation can be measured using a known molecular orientation meter, such as the Molecular Orientation Meter MOA-7015 from Oji Scientific Instruments Co., Ltd. The azimuth angle variation refers to the difference between the maximum and minimum values ​​of Rp60(0°), Rp60(45°), Rp60(90°), Rp60(135°), and Rp60(180°) measured at the above azimuth angles (0°, 45°, 90°, 135°, and 180°).

[0090] Rp60 (0°), Rp60 (45°), Rp60 (90°), Rp60 (135°), and Rp60 (180°) can be measured by measuring the reflectance of P waves with wavelengths of 400 to 700 nm at an incident angle θ = 60° using a spectrophotometer in 1 nm increments and calculating the average value. Here, the azimuth angle, which is the tilt direction, is defined as the azimuth angle in the direction of the main orientation axis of the multilayer laminate film, and five angles are used clockwise from this: 0°, 45°, 90°, 135°, and 180°. By keeping the azimuth angle variation of Rp60 at 10% or less, the display quality, such as the brightness of the information, can be maintained at the same level regardless of the orientation from which the image is projected.

[0091] To reduce the azimuthal variation in Rp60, for example, the in-plane refractive index unevenness of the multilayer laminate film of the present invention can be reduced. To reduce the in-plane refractive index unevenness of the film, the film can be biaxially stretched by stretching the film so as to reduce the difference in orientation between the longitudinal and width directions. The stretching conditions that reduce the difference in orientation between the longitudinal and width directions vary depending on the thermoplastic resins used and their combination. When polyester is used for Layer A, for example, a condition in which the stretch ratio in the width direction is slightly higher than that in the longitudinal direction is preferred, and more specifically, the difference between the two is 0.8 times or less. This effect is one of the characteristics of the multilayer laminate film of the present invention, and is an effect that cannot be achieved with a polarizing reflective film.

[0092] In the multilayer laminate film of the present invention, it is preferable that, in layers having a layer thickness of 1000 nm or less in the multilayer laminate film, the ratio of the total layer thickness (DA) of layers A to the total thickness (DB) of layers B: T (T = DA / DB) satisfies 0.80≦T≦1.00, and the ratio of the total layer thickness (DC) of layers C to the total thickness of layers B: S (S = DC / DB) satisfies 1.10≦S≦1.30. When T and S of the multilayer laminate film of the present invention take the above values, the transmittance of visible light incident perpendicularly to the film surface can be maintained high, while the average visible light reflectance of P waves incident at an angle of 60° to the normal to the film surface can be efficiently increased. Furthermore, by increasing the average visible light reflectance of P waves incident at an angle of 60° to the normal to the film surface, it becomes easy to satisfy Rp20≦Rp40<Rp60. As in the multilayer laminate film of the present invention, the dielectric constants X (i.e., related to the refractive index) are arranged in descending order from largest to smallest X. Ａ >X Ｂ >X Ｃ In the case of this configuration, the canceling effect of reflections of 1 / 2 wavelength to 1 / 4 wavelength in oblique directions is weakened by making S larger than T. In other words, it is possible to efficiently increase the average visible light reflectance of P waves when incident at an angle of 60° with respect to the normal to the film surface.

[0093] On the other hand, if S is made too large to make S greater than T, or if T is made too small, the canceling effect of ½ to ¼ wavelength reflections will be weakened not only in oblique directions but also in the front direction (perpendicular to the film surface), which may result in a decrease in the transmittance of visible light incident perpendicularly to the film surface and an increase in the saturation of transmitted light incident perpendicularly to the film surface. Therefore, it is preferable that the lower limit of T is 0.80 and the upper limit of S is 1.30. Conversely, if S is smaller than T, the canceling effect of ½ to ¼ wavelength reflections in oblique directions will be strengthened, which may result in a decrease in the average visible light reflectance of P waves when incident at a 60° angle to the normal to the film surface. Therefore, it is preferable that the upper limit of T is 1.00 and the lower limit of S is 1.10. If S exceeds 1.10, the condition Rp20≦Rp40<Rp60 may not be satisfied.

[0094] Hereinafter, the preparation of the multilayer laminate film of the present invention will be specifically explained by way of an example, but the multilayer laminate film of the present invention is not limited thereto. When the multilayer laminate film of the present invention has the above-mentioned multilayer laminate film configuration, it can be prepared by the following method.

[0095] The first, second, and third thermoplastic resins are supplied in molten form from three extruders: extruder A for Layer A, extruder B for Layer B, and extruder C for Layer C. The molten thermoplastic resins from each channel are laminated using a multi-manifold feed block and square mixer, or a comb feed block alone, which are known lamination devices, to form multiple repeating unit structures in which the three resin layers (Layer A, Layer B, and Layer C) are arranged in the order Layer A / Layer B / Layer C / Layer B. The molten laminate is then melt-extruded into a sheet using a T-type die or the like, and then cooled and solidified on a casting drum to obtain an unstretched multilayer laminate film. Each resin may be dried in hot air, vacuum, or nitrogen before being fed to the extruder, as needed.

[0096] In particular, to efficiently obtain a multilayer laminate structure, it is preferable to use a feed block with fine slits. Using such a feed block prevents the device from becoming excessively large, reduces the amount of foreign matter generated due to thermal degradation, and enables high-precision lamination even when the number of layers is extremely large. Furthermore, the lamination accuracy in the width direction is significantly improved compared to conventional technology. Furthermore, this device allows the thickness of each layer to be adjusted by the shape (length, width) of the slits, making it possible to achieve any layer thickness. The molten multilayer laminate sheet thus formed with the desired layer structure is introduced into a die and cooled and solidified on a casting drum to obtain an unstretched multilayer laminate film.

[0097] Next, this unstretched multilayer laminate film is stretched and heat-treated. The stretching method is preferably a known sequential biaxial stretching method or a simultaneous biaxial stretching method. The stretching temperature is preferably in the range from the glass transition temperature of the unstretched laminate film to the glass transition temperature + 80°C. The glass transition temperature can be measured according to JIS-K-7122 (2012). If the unstretched multilayer laminate film has multiple glass transition temperatures, the stretching temperature is preferably in the range from the highest glass transition temperature to the glass transition temperature + 80°C. The stretching ratio is preferably 2.0 to 8.0 times in both the longitudinal and width directions, more preferably 3.0 to 6.0 times. The difference between the stretching ratios in the longitudinal and width directions is preferably small, more specifically, 0.8 times or less. The longitudinal stretching is preferably performed by utilizing the difference in peripheral speed between the rolls of a longitudinal stretching machine. The subsequent widthwise stretching is preferably performed using a known tenter method. That is, the uniaxially stretched multi-layer laminate film can be stretched in the width direction by conveying the film while holding both widthwise ends with clips and widening the gap between the opposing clips in the width direction.

[0098] Simultaneous biaxial stretching is also preferably performed using a tenter. The case of simultaneous biaxial stretching will be described below. An unstretched laminate film cast on a cooling roll is introduced into a simultaneous biaxial tenter, and while both widthwise ends of the film are held by clips, the film is conveyed and stretched simultaneously and / or stepwise in the longitudinal and widthwise directions. Stretching in the longitudinal direction is achieved by increasing the distance between clips on the same side, and stretching in the widthwise direction is achieved by increasing the distance between the rails on which the clips run, thereby increasing the distance between opposing clips. The tenter clips used for stretching and heat treatment in the present invention are preferably driven by a linear motor system. Other methods include a pantograph system and a screw system. Among these, the linear motor system is advantageous in that the high degree of freedom of each clip allows the stretching ratio to be freely changed.

[0099] It is also preferable to perform heat treatment after stretching. The heat treatment temperature is preferably in the range of from the stretching temperature or higher to the melting point of the thermoplastic resin of Layer A, and it is also preferable to perform a cooling step after the heat treatment at a temperature in the range of −30°C or lower from the heat treatment temperature. The melting point is measured in accordance with JIS-K-7122 (2012). In addition, in order to reduce the thermal shrinkage rate of the film, it is also preferable to shrink (relax) the film in the width direction and / or length direction during the heat treatment step or cooling step. The relaxation rate is preferably in the range of 1% to 10%, more preferably 1 to 5%. Finally, the film is wound up on a winder to produce the multilayer laminate film of the present invention.

[0100] In the projection image display member of the present invention, the multilayer laminate film of the present invention is positioned on at least one surface of a transparent support or between transparent members. Specific examples of the projection image display member of the present invention are described below. Figures 8(a) and 8(b) show configurations in which an optional antireflection layer 31 is laminated on the multilayer laminate film of the present invention, while Figure 8(c) shows a configuration in which an optional antireflection layer 31 and a functional layer 32 are laminated on the multilayer laminate film of the present invention. The antireflection layer 31 is a layer that prevents reflection on the surface of the projection image display member, and is preferably positioned on at least one surface of the multilayer laminate film 4. As shown in Figure 8(a), by having the antireflection layer 31 on at least one surface of the multilayer laminate film 4, oblique reflection of S waves on the surface of the projection image display member can be suppressed. As a result, when the projection image display member of the present invention is used as a projection member for an augmented reality device, reflection of surrounding scenery other than the image can be suppressed.

[0101] 8(c), the projection image display member preferably has a functional layer 32 on at least one surface of the multilayer laminate film 4. Examples of the functional layer 32 include a hard coat layer, an abrasion-resistant layer, an anti-scratch layer, an anti-reflection layer, a color correction layer, an ultraviolet absorbing layer, a light stabilizing layer, a heat ray absorbing layer, a printing layer, a gas barrier layer, and an adhesive layer. These layers may have a single layer structure or a multilayer structure, and one layer may have multiple functions.

[0102] Another example is a laminate (FIGS. 9(a) to 9(c)) in which a multilayer laminate film 4 is positioned between transparent supports 18. Here, lamination of an anti-reflection layer 31 and a functional layer 32 is optional. Examples of the laminated transparent support 18 include glass and transparent resin substrates, and their thickness is preferably 0.3 mm or more, and more preferably 1 mm or more, to ensure supportability. While there is no particular upper limit on the thickness of the transparent support 18, excessive thickness unnecessarily increases the weight of the projection image display component, so a thickness of 10 mm or less is preferred. Furthermore, the transparent support 18 can have not only a flat shape but also a curved shape. Examples of glass for the transparent support 18 include not only single-layer glass but also laminated glass and tempered glass used in automobile windshields, side windows, and rear windows, as well as glass building materials such as plate glass, tempered glass, double-glazed glass, and vacuum glass. Examples of transparent resin substrates for the transparent support 18 include polyethylene terephthalate, polycarbonate, acrylic, polyvinyl chloride, polyethylene, polypropylene, polymethylpentene and its copolymers, and acrylonitrile-butadiene-styrene copolymers. These transparent resin substrates may be a single component or a mixture of multiple components. Among these, in the projection image display member of the present invention, from the viewpoints of transparency, durability, and supportability, it is more preferable that the transparent support contains at least one of glass, polycarbonate resin, and acrylic resin. For the same reason, it is also preferable that the thickness of the projection image display member is 0.5 mm or more and 7 mm or less.

[0103] The transparent support 18 and the multilayer laminate film 4 may be laminated directly as shown in Figures 8(a) and 9(a). Alternatively, as shown in Figures 8(b), 8(c), and 9(b), 9(c), lamination by forming an adhesive layer 19 using a pressure-sensitive adhesive or adhesive is also possible. Examples of pressure-sensitive adhesives and adhesives include vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, ethylene-vinyl acetate copolymers, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, polyvinyl ether, nitrile rubbers, styrene-butadiene rubbers, natural rubbers, chloroprene rubbers, polyamides, epoxy resins, polyurethanes, acrylic resins, celluloses, polyvinyl chloride, polyacrylic esters, and polyisobutylene. These pressure-sensitive adhesives and adhesives may be used alone or in combination, and may contain additives such as viscosity adjusters, plasticizers, heat stabilizers, antioxidants, UV absorbers, antistatic agents, lubricants, colorants, and crosslinking agents.

[0104] These adhesives may be in liquid, gel, block, powder, film, etc. before processing. Methods for solidifying the adhesive layer include solvent evaporation, moisture curing, heat curing, curing agent mixing, anaerobic curing, ultraviolet curing, thermal melting and cooling, and pressure-sensitive. Lamination methods include lamination molding, injection molding, vacuum molding, pressure molding, and combined vacuum and pressure molding. Projection image display members are produced by applying heat, pressure, and the above-mentioned methods for solidifying the adhesive layer.

[0105] Next, a projection image display device using the multilayer laminate film of the present invention will be described. The projection image display device of the present invention is a projection image display device comprising the multilayer laminate film of the present invention or the projection image display member of the present invention, and a video projector (light source) that irradiates light onto the display surface.

[0106] An example of a usage form of a projection image display device using the multilayer laminate film or projection image display member of the present invention is the projection image display device shown in Figure 10. In the projection image display device of the present invention shown in Figure 10, a projection image 38 is irradiated from an image projection device 37 onto a projection image display member 33, and the image is projected onto the projection image display member 33. Furthermore, by passing a background 34, which provides information about the surrounding scenery, through the projection image display member 33, the eyes 35 of a user of the projection image display device can visually recognize the image superimposed on the surrounding scenery. Examples of the image projection device 37 include a liquid crystal projector, an RGB laser, a DLP (Digital Light Processing), an LCOS (Liquid Crystal on Silicon), a liquid crystal display, and an organic EL display.

[0107] In order to reduce the occurrence of double images and the deterioration of visibility when wearing polarized sunglasses, the projection image display member of the present invention preferably has a P-wave intensity (P-wave intensity / (P-wave intensity + S-wave intensity)) of 51% or more of the intensity of light incident on the display surface of the projection image display member. The P-wave intensity as a percentage of the intensity of light incident on the display surface of the projection image display member is sometimes simply referred to as "P-wave intensity." The following describes the issues of double images and the deterioration of visibility when wearing polarized sunglasses, which are problems with projection image display devices, with reference to the drawings. As shown in FIG. 11( a), a conventional projection image display member 39 made of glass or a transparent resin film reflects S-waves incident at an angle and transmits P-waves. Therefore, S-waves are used as the light for the projected image incident on the display surface of the projection image display member. Double images occur when light is reflected from both the front and back surfaces of the image display member 39, and the misalignment of these light rays causes the displayed image to appear double.

[0108] Furthermore, reduced visibility when wearing polarized sunglasses occurs because the projected image reflected on the projection image display member is derived from S-waves. When the projected image is viewed through polarized sunglasses that absorb S-waves, the light from the projected image is absorbed by the polarized sunglasses. The projection image display member 33 ( FIG. 11( b) ) of the present invention reflects P-waves incident at an angle, allowing P-waves to be used as the light for the projected image incident on the display surface of the projection image display member. Since P-waves are reflected only within the film and not on the front or back surfaces of the projection image display member, the problem of double images is reduced. Furthermore, since P-waves are transmitted through polarized sunglasses, the reduction in visibility of the projected image caused by polarized sunglasses is also reduced. From the above perspectives, the intensity of P-waves is preferably 51% or more, more preferably 90% or more, with an upper limit of approximately 99.9% from the perspective of polarization control accuracy. In the projection image display device of the present invention, when the P-wave intensity is set to 51% or more, the incident angle of the projection image from the light source (reference numeral 36 in FIG. 10) with respect to the normal to the projection image display member is preferably 30° or more, more preferably in the range of 50° to 75°. Here, when the projection image display member has a curved surface even in part, the incident angle is the angle with respect to the tangent plane at the point where the projection image is incident on the projection image display member. Methods for increasing the P-wave intensity include designing the light source so that the image emitted from the light source is a P-wave, and placing a retardation plate or polarizing plate on the light beam between the light source and the projection image display member for the image emitted from the light source toward the projection image display member.

[0109] The multilayer laminate film or projection image display member of the present invention can be used as a retarder. Examples of retarders include half-wave retarders and quarter-wave retarders. Half-wave retarders can change the orientation of linearly polarized light. Therefore, when an image is linearly polarized, using a half-wave retarder can control the orientation of the linearly polarized light of the image after passing through the half-wave retarder so that it becomes a P wave relative to the projection image display member. A quarter-wave retarder can change circularly polarized light to linearly polarized light. Therefore, when an image is circularly polarized or elliptically polarized, using a quarter-wave retarder can control the orientation of the linearly polarized light of the image after passing through the quarter-wave retarder so that it becomes a P wave relative to the projection image display member. A polarizing plate can pass linearly polarized light only in a specific orientation and absorb or reflect linearly polarized light in other orientations. Therefore, using a polarizing plate can control the orientation of the linearly polarized light after passing through the polarizing plate so that it becomes a P wave relative to the projection image display member.

[0110] Another application of a projection image display device using the multilayer laminate film or projection image display member of the present invention is to wear it on the head, more specifically, in the form of glasses. Figure 12 shows one embodiment of the projection image display device of the present invention. In the projection image display device of Figure 12, a projection image 38 emitted from an image projector 37 passes through a light-guiding member 40, is reflected by a reflecting member 41, and is then reflected by a projection image display member 33, thereby projecting the image onto the user's eye 35 while maintaining visibility of the background 34. Examples of the reflecting member 41 include a mirror having a metal layer or a dielectric multilayer film on the surface of a support, and a multilayer laminate film having thermoplastic resins with different refractive indices laminated alternately. The light-guiding member 40 is preferably transparent, with low absorption of the projected image, and has a small phase difference to avoid disturbing the polarization of the projected image. Examples of preferred materials include polyethylene terephthalate, polycarbonate, acrylic, polyvinyl chloride, polyethylene, polypropylene, cycloolefin, polymethylpentene and its copolymers, and acrylonitrile-butadiene-styrene copolymers.

[0111] The following describes a transportation system of the present invention. The transportation system of the present invention includes a projection image display device, and at least a portion of light emitted from a light source toward the projection image display member is incident on the projection image display member at an angle of 50° to 75° relative to the normal to the projection image display member. Preferred examples of transportation include automobiles, railway vehicles, and aircraft. In particular, automobiles equipped with a projection image display device using the projection image display member of the present invention on one or more of the windshield, side window, and rear window are preferred. This configuration makes it possible to suppress double images and improve image visibility for the driver. Here, when the projection image display member has a curved surface, even in part, the incident angle is the angle relative to the tangent plane at the point where the projected image on the projection image display member is incident.

[0112] Furthermore, the transportation of the present invention preferably includes a projection image display device in which the radius of curvature in the horizontal direction at the center of the projection image display member is 1 m or more and 8 m or less. Here, the center of the projection image display member refers to the center of gravity. When the projection image display member has a horizontal curvature, the distance from the passenger to the projection image display member approaches the same distance compared to when the projection image display member is flat. This means that the focal lengths of the projected images are viewed at the same distance, allowing the images to be viewed without any discomfort.

[0113] The following describes a building of the present invention. The building of the present invention is equipped with the projection image display device of the present invention. The projection image display device of the present invention is preferably used in windows of the building, or for transparent signage and spatial presentation within the building.

[0114] The multilayer laminate film and projection image display member of the present invention will be described in more detail below using examples, but the multilayer laminate film and projection image display member of the present invention are not limited to the following embodiments.

[0115] [Methods for measuring physical properties and methods for evaluating effects] The methods for measuring properties and evaluating effects are as follows. (1) Number of laminations in multilayer laminate film, number of repeating unit structures, thickness of surface layers, and thickness of layers inside multilayer laminate film A cross section parallel to the thickness direction (direction perpendicular to the film surface) was cut out using a microtome, and the number of laminations in the multilayer laminate film, number of repeating unit structures, thickness of surface layers, and thickness of layers inside the multilayer laminate film were confirmed by observing the sample using a transmission electron microscope (TEM). Note that the cross section photographs were taken by cutting the sample into RuO ４ After staining, a transmission electron microscope JEM1400Plus (manufactured by JEOL Ltd.) was used under an accelerating voltage of 100 kV. The thickness of the surface layer of the multilayer laminate film was measured using the obtained TEM image with image processing software Image-Pro ver. 10. The layer thickness inside the multilayer laminate film was measured using the obtained TEM image with image processing software Image-Pro ver. 10 in vertical thick profile mode. The relationship between the thickness direction position and the average brightness of the region sandwiched between two lines in the width direction was read as numerical data, and the read data was subjected to numerical processing of a five-point moving average for the position (nm) and brightness data using the spreadsheet software "Excel" (registered trademark) (Microsoft Office 365 version 2022). Furthermore, the data on the periodically changing brightness obtained was differentiated, and the maximum and minimum values ​​of the differential curve were read using a VBA (Visual Basic for Applications) program, and the layer thickness was calculated by taking the distance between adjacent values ​​as the thickness of one layer. This operation was performed for each image, and the layer thicknesses of all layers were calculated, thereby determining the layer thicknesses within the multilayer laminate film.

[0116] (2) Proportion of repeat units having a total layer thickness of 250 nm to 630 nm or less The total layer thickness within each repeat unit was determined using the layer thickness within the multilayer laminate film determined in (1), and the percentage (%) was determined by dividing the number of repeat units having a total layer thickness of 250 nm to 630 nm or less by the total number of units.

[0117] (3) Lamination ratio (A / B) and lamination ratio (C / B) within repeat unit Using the layer thicknesses within the multilayer laminate film obtained in (1), the lamination ratio (A / B) was obtained within each repeat unit by dividing the thickness of layer A by the total thickness of layer B within the unit, and the lamination ratio (C / B) was obtained by dividing the thickness of layer C by the total thickness of layer B within the unit. For each of the obtained lamination ratios (A / B) and lamination ratios (C / B), the percentages (%) were obtained by dividing the number of repeat units with a lamination ratio of 0.8 to 1.3 by the total number of units. Similarly, for the lamination ratio (A / B), the percentages (%) of units with a lamination ratio of 0.8 to 1.1 and for the lamination ratio (C / B), the percentages (%) of units with a lamination ratio of 0.9 to 1.2 were obtained.

[0118] (4) Ratio of Total Layer Thickness (T, S) in Layers with a Layer Thickness of 1000 nm or Less Using the layer thicknesses inside the multilayer laminate film determined in (1), the ratio of the total layer thickness of layers A (DA) to the total thickness of layers B (DB): T (T = DA / DB), and the ratio of the total thickness of layers C (DC) to the total thickness of layers B: S (S = DC / DB) were determined for layers with a layer thickness of 1000 nm or less.

[0119] (5) Measurement of the dielectric constant X of the A layer, the B layer, and the C layer, and the repeating unit structure Electron energy loss spectroscopy (EELS) was performed to measure the dielectric constant X of each of the A layer, the B layer, and the C layer. A cross-sectional (thickness direction cross-section) cut sample of the measurement object was prepared in the direction of the main orientation axis of the measurement object by ultra-thin sectioning using an ultramicrotome. The dielectric constant of the prepared cross-sectional cut sample was measured using an atomic resolution analytical electron microscope ARM200F manufactured by JEOL Ltd. Specifically, an HAADF-STEM (High Angle Annular Dark-Field Scanning Transmission Electron Microscopy) image was acquired at an acceleration voltage of 80 kV and a beam spot size of 0.2 mmφ. After that, multipoint analysis (60 x 60 pixels, 20 nm / pixel) was performed on the layer to be measured at 50 msec to obtain data on energy loss and electron beam intensity. The same operation was performed on three points for each of the same thermoplastic resin layers in the multilayer laminate film, and data with an improved S / N ratio was obtained. From the obtained spectrum, background correction due to elastic scattering and removal of the multiple scattering effect were performed, and then the dielectric function of each layer was calculated using the Kramers-Kronig transformation shown in formula (C). The integral range during the Kramers-Kronig transformation was 0 to 200 eV. Based on the dielectric function of formula (C), the real and imaginary parts of the dielectric constant were calculated from formulas (D) and (E), respectively, and then the dielectric constant X was calculated from formula (F) which is the square root of the sum of the squares of these. From the calculated dielectric constants X, the order of magnitude of the dielectric constants X of the A layer, the B layer, and the C layer was determined. In formulas (C) to (F), Re is the real part, Im is the imaginary part, P is the Cauchy principal value, ε is the dielectric constant (average value), ε(ω) is the dielectric function, ε １ is the real part of the permittivity, ε ２ denotes the imaginary part of the dielectric constant, and ω and ω' denote the angular frequencies.

[0120]

[0121]

[0122]

[0123]

[0124] The repeating unit structure was measured by comparing the dielectric constants X of the A layer, B layer, and C layer at the measured layer position with the contrast of the TEM image measured in (1) at that layer position, and determining that the layers in the TEM image had three different contrasts as the A layer, B layer, and C layer, respectively, and confirming that the A layer, B layer, and C layer were laminated in a unit structure of the A layer / B layer / C layer / B layer.

[0125] (6) Transmittance Using a spectrophotometer (U-4100 Spectrophotometer) manufactured by Hitachi, Ltd., with a standard configuration (solid measurement system), the transmittance of wavelengths from 240 to 2600 nm was measured in 1 nm increments at incident angles θ of 0° and 10°. (Measurement conditions: slit 2 nm (visible) / automatic control (infrared), gain 2, scanning speed 600 nm / min.) From the measurement results, the average transmittance of wavelengths from 400 nm to 700 nm measured at an incident angle of 0° was calculated as the transmittance of visible light incident perpendicular to the film surface.

[0126] (7) Average visible light reflectance of P waves when incident at an angle of 60° relative to the normal to the film surface A spectrophotometer (U-4100 Spectrophotometer) manufactured by Hitachi, Ltd. was equipped with an attached variable angle reflection unit and a Glan-Taylor polarizer, and the reflectance of P waves in the wavelength range of 380 to 780 nm at an incident angle θ = 60° was measured in 1 nm increments. From the obtained reflectance, the average reflectance of P waves in the wavelength range of 400 nm to 700 nm was calculated. The 60° tilt direction was set to be along the main orientation axis of the multilayer laminate film.

[0127] (8) Average reflectance of P wave, Rp20, Rp40, Rp60 A Hitachi, Ltd. spectrophotometer (U-4100 Spectrophotometer) was equipped with an attached angle variable reflection unit and a Glan-Taylor polarizer, and the reflectance of P wave in the wavelength range of 400 to 700 nm at incident angles θ = 20 °, 40 °, and 60 ° was measured in 1 nm increments. From the obtained reflectance, Rp20, Rp40, and Rp60 were calculated as the average reflectance of P wave in the wavelength range of 400 nm to 700 nm at incident angles of 20 °, 40 °, and 60 °. The tilt directions of 20 °, 40 °, and 60 ° were along the main orientation axis of the multilayer laminate film.

[0128] (9) Azimuth Angle Variation in Average Reflectance of P Waves A Hitachi, Ltd. spectrophotometer (U-4100 Spectrophotometer) was equipped with an attached variable-angle reflection unit and a Glan-Taylor polarizer, and the reflectance of P waves in the wavelength range of 400 to 700 nm at an incident angle θ = 60° was measured in 1 nm increments for each of five azimuth angles: 0°, 45°, 90°, 135°, and 180° clockwise from an azimuth angle of 0° in the direction of the main orientation axis of the sample. From the obtained reflectances, the average reflectance of P waves in the wavelength range of 400 to 700 nm at an incident angle of 60° in each azimuth angle direction was calculated: Rp60(0°), Rp60(45°), Rp60(90°), Rp60(135°), and Rp60(180°). Furthermore, the difference between the maximum and minimum values ​​of the obtained Rp60 (0°), Rp60 (45°), Rp60 (90°), Rp60 (135°), and Rp60 (180°) was taken as the azimuth angle variation.

[0129] (10) Saturation of reflected light of P wave incident at 60° Based on JIS-Z-8781-3 (2016), the tristimulus values ​​X, Y, Z of the CIE1931 color system and the tristimulus values ​​Xn, Yn, Zn of specific white light are calculated, and a* and b* of the CIE1976 L*a*b* color space are calculated based on the obtained X, Y, Z and Xn, Yn, Zn according to JIS-Z-8781-4 (2013), and the saturation C ＊ The value is a ＊ and b ＊ It was calculated by taking the square root of the sum of squares.

[0130] <Calculation of tristimulus values ​​X, Y, Z, and tristimulus values ​​Xn, Yn, Zn of specific white light> The relative color stimulus function (φ(λ)) in JIS-Z-8781-3 (2016) was defined as the product of the spectral reflectance coefficient (R(λ)) and the relative spectral distribution (S(λ)) of the illumination light, φ(λ) = R(λ) × S(λ). Here, the spectral reflectance coefficient is the reflectance of P waves with wavelengths of 380 nm to 780 nm at an incident angle of 60°, as determined in section (6). The relative spectral distribution was determined using auxiliary illuminant C in JIS-Z-8720 (2012). Using the relative color stimulus function, tristimulus values ​​X, Y, and Z were calculated based on formula (G) of JIS-Z-8781-3 (2016) at wavelengths of 380 nm to 760 nm, at wavelength intervals of 5 nm, by multiplying the sum of the products of the relative color stimulus function and the CIE 1931 color matching functions (H) listed below by the standardization coefficient k. The tristimulus values ​​Xn, Yn, and Zn of specific white light were calculated by multiplying the sum of the products of the relative spectral distribution and the CIE 1931 color matching functions (H) by the standardization coefficient k. In formula (G), λ represents the wavelength and Δλ represents the wavelength interval.

[0131]

[0132]

[0133] (11) Saturation of transmitted light incident perpendicularly to the film surface Based on JIS-Z-8781-3 (2016), the tristimulus values ​​X, Y, Z of the CIE1931 color system and the tristimulus values ​​Xn, Yn, Zn of specific white light are calculated, and the a* and b* of the CIE1976L*a*b* color space are calculated based on the obtained X, Y, Z and Xn, Yn, Zn, and the saturation C ＊ The value is a ＊ and b ＊ It was calculated by taking the square root of the sum of squares.

[0134] <Calculation of Tristimulus Values ​​X, Y, Z, and Tristimulus Values ​​Xn, Yn, Zn of Specific White Light> The relative color stimulus function (φ(λ)) in JIS-Z-8781-3 (2016) was defined as the product of the spectral transmittance coefficient (T(λ)) and the relative spectral distribution (S(λ)) of the illumination light, φ(λ) = T(λ) × S(λ). Here, the spectral transmittance coefficient is the transmittance at wavelengths of 380 nm to 780 nm calculated in section (6). The relative spectral distribution was determined using auxiliary illuminant C in JIS-Z-8720 (2012). Using the relative color stimulus function, the tristimulus values ​​X, Y, and Z were calculated by multiplying the sum of the products of the relative color stimulus function and the CIE 1931 color matching functions (G) below by the standardization coefficient k, based on formula (G) in JIS-Z-8781-3 (2016), for wavelengths of 380 nm to 760 nm, at wavelength intervals of 5 nm. The tristimulus values ​​Xn, Yn, and Zn of a specific white light were calculated by multiplying the sum of the products of the relative spectral distribution and the CIE 1931 color matching function (G) by a standardization coefficient k.

[0135] (12) Near-infrared reflectance: Using a spectrophotometer (U-4100 Spectrophotometer) manufactured by Hitachi, Ltd., with a standard configuration (solid-state measurement system), the reflectance at wavelengths of 240 to 2600 nm was measured in 1 nm increments at an incident angle θ of 10°. (Measurement conditions: slit 2 nm (visible) / automatic control (infrared), gain 2, scanning speed 600 nm / min.) From the obtained reflectance, the wavelength range in which the reflectance at near-infrared wavelengths was 40% or higher and the average reflectance in that wavelength range were determined.

[0136] (13) Refractive index and plane orientation coefficient of layer A The refractive index of the surface layer of the multilayer laminate film was measured using a prism coupler SPA-400 manufactured by Cylon Technology Co., Ltd. at a measurement laser wavelength of 633 nm. The in-plane refractive index (average value of the X and Y directions) and the perpendicular refractive index (average value of the X and Z directions) were determined in the direction of the main orientation axis of the film (X direction) and in the direction perpendicular to the main orientation axis (the direction parallel to the film surface is the Y direction, and the direction perpendicular to the film surface is the Z direction). The (in-plane refractive index) - (plane perpendicular refractive index) was calculated, and this was used as the plane orientation coefficient.

[0137] (14) Ratio of the Dielectric Constants in the In-Plane and Normal Directions of Layer B The dielectric constant in the normal direction of Layer B was taken as the dielectric constant of Layer B determined in (5). The dielectric constant in the in-plane direction of Layer B was determined as follows. First, the dielectric constant was determined in the normal direction to the surface of the multilayer laminate film by electron energy loss spectroscopy (EELS) measurement as described in (5), and this was used as the dielectric constant in the in-plane direction of Layer A. Regarding the resin used in Layer C, thermoplastic resin pellets vacuum-dried at 70°C for 48 hours were melted at 280°C and then pressed and quenched in a press to produce a sheet with a thickness of 200 μm. The dielectric constant was determined in the normal direction to the surface of this sheet by electron energy loss spectroscopy (EELS) measurement as described in (5), and this was used as the dielectric constant in the in-plane direction of Layer C. Next, the surface of the multilayer laminate film was polished, and the dielectric constant was determined in the normal direction to the polished surface by electron energy loss spectroscopy (EELS) measurement as described in (5). If this dielectric constant differed from the dielectric constants of the A and C layers in the in-plane direction, this dielectric constant was taken as the dielectric constant of the B layer in the in-plane direction. Here, "different from the dielectric constants of the A and C layers in the in-plane direction" was defined as a difference of 3% or more. Polishing and dielectric constant measurement were continued until the dielectric constant measured by the above method showed a value different from the dielectric constants of the A and C layers in the in-plane direction, and at the point when a value different from the dielectric constants of the A and C layers in the in-plane direction was found, this value was taken as the dielectric constant of the B layer in the in-plane direction. Based on the obtained dielectric constants of the B layer in the in-plane direction and the perpendicular direction, the ratio ((in-plane direction - perpendicular direction) / perpendicular direction x 100(%)) was calculated.

[0138] (15) Discrimination of crystalline / amorphous nature of layers A, B, and C 5 mg of resin pellets used for layers A, B, and C were weighed on an electronic balance, sandwiched between aluminum pans, and measured using a DSCvesta Smart Loader manufactured by Rigaku Corporation, in accordance with JIS-K-7122 (2012), by raising the temperature from 25 ° C. to 300 ° C. at a rate of 20 ° C. / min. The melting enthalpy (ΔHm) was determined from the obtained DSC data, and layers using resins showing a melting enthalpy of 5 J / g or more were considered crystalline, and layers using resins showing a melting enthalpy of less than 5 J / g were considered amorphous.

[0139] (16) Refractive Index of Layer C Thermoplastic resin pellets vacuum dried at 70°C for 48 hours were melted at 280°C, and then pressed in a press and quenched to produce a sheet with a thickness of 200 μm. The refractive index of the resulting sheet was measured in the same manner as in (13) using a Prism Coupler SPA-400 manufactured by Cylon Technology Co., Ltd. Since the resin used in Layer C is amorphous, the refractive index of the sheet and the refractive index in the multilayer laminate film were considered to be the same.

[0140] (17) Refractive Index of Layer B Since Layer B is an internal layer of the multilayer laminate film, the refractive index was measured not for the multilayer laminate film but for a film of the layer B resin alone produced under the same stretching and heat treatment conditions as the multilayer laminate film, using a Prism Coupler SPA-400 manufactured by Cylon Technology. The laser wavelength used for the measurement was 633 nm, and the in-plane refractive index was the average value of the values ​​measured on both sides of the film in the direction of the main orientation axis and in the direction perpendicular to the main orientation axis. The perpendicular-to-plane refractive index was the average value of the values ​​measured on both sides of the film in the direction of the main orientation axis and in the direction perpendicular to the main orientation axis.

[0141] (18) Verification of the refractive index of layer B of the multilayer laminate film An optical simulation of reflectance was performed using the layer thickness of the multilayer laminate film obtained in (1), the refractive index of layer A of the multilayer laminate film obtained in (13), the refractive index of layer C obtained in (16), and the refractive index of layer B obtained in (17). The optical simulation results were compared with the near-infrared reflectance measured in (12). If the difference between the two was ±3% or less, the refractive index of layer B obtained in (17) was considered to be the refractive index of layer B of the multilayer laminate film. The optical simulation was performed by performing calculations using a VBA program using the characteristic matrix method of optical thin films (Mitsunobu Kohiyama (2006). Optical thin film filter design, Optronics Co., Ltd.).

[0142] (19) Main Orientation Axis Direction The degree of orientation was measured using a molecular orientation analyzer MOA-7015 manufactured by Oji Scientific Instruments Co., Ltd., and the direction with the greatest degree of orientation was taken as the main orientation axis direction.

[0143] (20) Evaluation of Projection Image Display Device A Dreammaker display (SP-133CM) was used as the light source, and the projection image display member was placed at a 45° angle relative to the light source. Light emitted perpendicularly from the light source was incident at a 45° angle relative to the normal to the surface of the projection image display member. The P-wave intensity (P-wave intensity / (P-wave intensity + S-wave intensity)) of the image incident on the display surface of the projection image display member was adjusted by controlling the transmission axis direction of the polarizing plate placed directly above the light source. A white lattice-shaped image was used as the image emitted from the light source. Figure 13 shows a schematic diagram of the evaluation configuration. The image projected onto the projection image display member was visually evaluated for each item according to the following criteria. While the detailed configuration of the projection image display member 33 is not shown in Figure 13, the projection image display members in each example and comparative example had the configuration shown in Table 3. In FIG. 13, the reference numerals 33 to 35, 37, and 38 respectively indicate the projection image display member 33, the background 34, the eyes of the projection image display device user 35, the image projection device 37, and the projected image 38.

[0144] (Displayability of projected images at an incident angle of 60°) Evaluation was based on the following criteria, with A and B being considered acceptable. A: The projected image was very bright. B: The projected image was bright. C: The projected image was dark or not visible. (Double image visibility of projected images at an incident angle of 60°) Evaluation was based on the following criteria, with A and B being considered acceptable. Double images here refer to the phenomenon in which the projected image appears to be split into two or more parts. Double images were not limited to double images, but also included cases where the image appeared to be triple or more multiplexed. A: No double images were visible. B: Double images were observed to a degree that did not affect image visibility. C: Double images that exceeded the level of B were observed. D: The projected image was not visible, so the visibility of the double image could not be evaluated. (Visibility of grid-like images in projected images) Evaluation was based on the following criteria, with A and B being considered acceptable. A: A grid image without distortion was visible. B: A grid image with significant distortion was visible. C: A lattice image with very large distortion was visible. D: The projected image was not visible, so it was not possible to evaluate the distortion of the lattice image. (Color visibility of projected image) Evaluation was based on the following criteria, with A to C being considered acceptable. A: A white color that was almost the same as the projected image was visible. B: An image in which the color had changed slightly from white was visible, to the extent that it did not pose a practical problem. C: An image in which the color had changed from white was visible. D: The projected image was not visible, so it was not possible to evaluate the color visibility. (Background visibility) Evaluation was based on the following criteria, with A and B being considered acceptable. A: The background was clearly visible. B: The background was visible enough to pose no practical problems. C: The background was dark enough to exceed the level of B. D: The background was dark enough to exceed the level of C, causing practical problems, or the background was not visible.

[0145] (21) Heat-shielding performance evaluation Using the transmittance at an incident angle of 10° measured in (6) and the reflectance at an incident angle of 10° measured in (12), the solar heat gain coefficient (Tts) was calculated according to ISO 13837:2008(E). Tts refers to the ratio (%) of solar heat energy that passes through the film or projection image display member, assuming that the solar heat energy incident on the film or projection image display member is 100; a lower value indicates higher heat-shielding performance. A value of 80% or less was considered to have heat-shielding performance.

[0146] (22) Glass transition temperature and melting point of resin and unstretched multilayer laminate film 5 mg of thermoplastic resin pellets or unstretched multilayer laminate film was weighed on an electronic balance, sandwiched between aluminum pans, and measured using a DSCvesta Smart Loader manufactured by Rigaku Corporation, in accordance with JIS-K-7122 (2012), by raising the temperature from 25 ° C. to 300 ° C. at a rate of 20 ° C. / min. The glass transition temperature (Tg) and melting point (Tm) were determined from the obtained DSC data. The highest glass transition temperature of the unstretched multilayer laminate film is shown in Table 1.

[0147] [Thermoplastic Resins Used in Films] The following resins were used to produce the films used in each Example and Comparative Example. All of these were thermoplastic resins, with Resins A, B, F, G, and M being crystalline, and Resins C, D, E, H, I, J, K, and L being amorphous. Resin A: polyethylene naphthalate copolymer (polyethylene naphthalate obtained by copolymerizing 6 mol% of polyethylene glycol having a molecular weight of 400 with respect to the total diol component), Tg = 93°C, Tm = 253°C. Resin B: polyethylene terephthalate, Tg = 78°C, Tm = 254°C. Resin C: polyethylene terephthalate copolymer (polyethylene terephthalate obtained by copolymerizing 30 mol% of 2,6-naphthalenedicarboxylic acid with respect to the total acid component), Tg = 95°C, no Tm was observed. Resin D: polyethylene naphthalate copolymer (polyethylene naphthalate copolymerized with 35 mol% of paraxylene glycol component relative to the total diol components and 8 mol% of polyethylene glycol having a molecular weight of 400 relative to the total diol components), Tg = 87°C, Tm not observed. Resin E: polyethylene naphthalate copolymer (polyethylene naphthalate copolymerized with 30 mol% of isophthalic acid component relative to the total acid components and 6 mol% of polyethylene glycol having a molecular weight of 400 relative to the total diol components), Tg = 73°C, Tm not observed. Resin F: pellets obtained by blending pellets of Resin J and Resin B described below in a ratio of 60% by mass / 40% by mass. Tg = 79°C, Tm = 243°C. Resin G: polyethylene terephthalate copolymer (polyethylene terephthalate copolymerized with 12 mol% of isophthalic acid component relative to the total acid components), Tg = 75°C, Tm = 218°C. Resin H: Polymethyl methacrylate, Tg = 103°C, Tm not observed. Resin I: Polyethylene terephthalate copolymer (polyethylene terephthalate copolymerized with 20 mol% of a cyclohexanedicarboxylic acid component relative to the total acid components and 20 mol% of a spiroglycol component relative to the total diol components), Tg = 76°C, Tm not observed. Resin J: Polyethylene terephthalate copolymer (polyethylene terephthalate copolymerized with 33 mol% of a cyclohexanedimethanol component relative to the total diol components), Tg = 80°C, Tm not observed.Resin K: polyethylene naphthalate copolymer (polyethylene naphthalate copolymerized with 20 mol% isophthalic acid component based on the total acid component and 5 mol% polyethylene glycol having a molecular weight of 400 based on the total diol component), Tg = 85°C, Tm = 215°C. Resin L: polyethylene terephthalate copolymer (polyethylene terephthalate copolymerized with 50 mol% 2,6-naphthalenedicarboxylic acid component based on the total acid component), Tg = 105°C, Tm = not observed. Resin M: polyethylene terephthalate copolymer (polyethylene terephthalate copolymerized with 18 mol% cyclohexanedimethanol component based on the total diol component), Tg = 78°C, Tm = 220°C, ΔHm = 13 J / g.

[0148] (Production of Multilayer Laminated Film and Film) A multilayer laminated film and a film were produced as follows. Table 1 shows the film-forming conditions, and Table 2 shows the evaluation results.

[0149] Example 1 Resin A was used as the thermoplastic resin constituting Layer A, Resin C as the thermoplastic resin constituting Layer B, and Resin H as the thermoplastic resin constituting Layer C. Resins A, C, and H were each melted at 280°C in separate extruders, passed through five FSS-type leaf disc filters, and then metered using a gear pump so that the discharge ratios were Layer A / Layer B = 1.42 and Layer C / Layer B = 1.05. The layers were laminated in a 601-layer feedblock (lamination device) (the number of repeating units was 150, with 151 Layer A layers, 300 Layer B layers, and 150 Layer C layers) designed so that the layer thicknesses of the Layer A, Layer B, and Layer C changed continuously from one surface layer to the opposite surface layer, and the laminated structure was (Layer A / Layer B / Layer C / Layer B)nA layers (n is an integer representing the number of repeating units) according to formula (A) so that the reflected wavelength at an incident angle of 10° was 850 nm to 1750 nm. The ratio of the resin discharged by the gear pump is generally called the lamination ratio, and since the discharged amount includes the outermost layer A, the discharged amount of the protective layer A is larger.

[0150] The molten laminate was then fed to a T-die and formed into a sheet, after which it was rapidly cooled and solidified on a casting drum maintained at a surface temperature of 25°C while applying an electrostatic voltage of 8 kV with a wire, to obtain an unstretched multilayer laminate film. This unstretched multilayer laminate film was longitudinally stretched (stretched in the longitudinal direction) at a temperature of 105°C and a stretch ratio of 3.6 times, and both sides were subjected to corona discharge treatment in air. Then, an easy-adhesion layer-forming film coating liquid (a 1:1 (mass ratio) mixture of a polyester resin with a glass transition temperature of 18°C ​​and a polyester resin with a glass transition temperature of 82°C, further mixed with 3 parts by mass of silica particles with an average primary particle diameter of 100 nm relative to the mixed resin) was applied by a bar coating method using a #4 bar coater. The average particle diameter of the primary particles referred to here is a value measured by dynamic light scattering. The resulting uniaxially stretched multilayer laminate film was then gripped at both widthwise ends with clips and introduced into a tenter, where it was transversely stretched (stretched in the width direction) at a temperature of 120°C and a stretch ratio of 4.2. The transversely stretched multilayer laminate film was then heat-treated at 210°C and relaxed by 1% in the width direction, and cooled to 100°C to obtain a multilayer laminate film with a thickness of 71 μm (both surface layers were 5 μm thick). The evaluation results are shown in Table 2. The film thickness, number of layers, surface layer thickness, and lamination ratio were determined by adjusting the take-up speed of the casting drum, the number of slits in the feed block, the slit width of the feed block, and the discharge rate. The resin of each layer, the number of layers, the surface layer thickness, the total thickness, the lamination ratio, and the film-forming conditions were as shown in Table 1. The results are shown in Table 2. The film thickness, number of layers, surface layer thickness, and lamination ratio were determined by adjusting the take-up speed of the casting drum, the number of slits in the feed block, the slit width of the feed block, and the discharge rate.

[0151] (Examples 2 to 18 and Comparative Examples 1 and 4 to 8) Multilayer laminate films were obtained in the same manner as in Example 1, except that the resin of each layer, the number of layers, the thickness of the surface layer, the total thickness, the lamination ratio, and the film-forming conditions were as shown in Table 1, and that a feed block of the following design was used. The evaluation results are shown in Table 2. The feed blocks used were as follows. Feed block of Example 2: A 401-layer feed block (lamination device) (the number of repeating units was 100, with 101 A layers, 200 B layers, and 100 C layers) designed so that the layer thicknesses of the A, B, and C layers changed continuously from one surface layer to the opposite surface layer according to formula (A) so that the reflected wavelength at an incident angle of 10° was 850 nm to 1700 nm, and the lamination structure was (A layer / B layer / C layer / B layer)nA layers (n is an integer representing the number of repeating units). Feedblock of Example 3: A 201-layer feedblock (lamination device) (number of repeating units: 50, 51 A layers, 100 B layers, 50 C layers) designed so that the layer thicknesses of the A layers, B layers, and C layers change continuously from one surface layer to the opposite surface layer according to formula (A) so that the reflected wavelength at an incident angle of 10° is 850 nm to 1650 nm, and the lamination structure is (A layer / B layer / C layer / B layer)nA layers (n is an integer representing the number of repeating units).Feedblocks of Examples 4, 7, 9, 10, 13-18, and Comparative Examples 1 and 6-9: The same feedblock as in Example 1 was used.

[0152] Feedblocks of Examples 5 and 6: A 601-layer feedblock (stacking device) (number of repeating units: 150, 151 A layers, 300 B layers, 150 C layers) designed so that the layer thicknesses of the A, B, and C layers change continuously from one surface layer to the opposite surface layer according to formula (A) so that the reflected wavelength at an incident angle of 10° is 850 nm to 1650 nm, and the stacking structure is (A layer / B layer / C layer / B layer)nA layers (n is an integer representing the number of repeating units). Feed block of Example 8: A 601-layer feed block (stacking device) (number of repeating units: 150, 151 A layers, 300 B layers, 150 C layers) designed so that the layer thicknesses of the A, B, and C layers change continuously from one surface layer to the opposite surface layer according to formula (A) so that the reflected wavelength at an incident angle of 10° is 850 nm to 1400 nm, and the stacking structure is (A layer / B layer / C layer / B layer)nA layers (n is an integer representing the number of repeating units). Feedblock of Example 11: A 601-layer feedblock (lamination device) (the number of repeating units is 150, with 151 A layers, 300 B layers, and 150 C layers) designed so that the layer thicknesses of the A, B, and C layers change continuously from one surface to the opposite surface according to formula (A) so that the reflected wavelength at an incident angle of 10° is 850 nm to 1750 nm, and the layer structure is (A layer / B layer / C layer / B layer)nA layers (n is an integer representing the number of repeating units). The feedblock was designed so that the lamination ratios (A / B) and (C / B) within the units were the same as those of Example 1 for the 1st to 528th layers, and 0.7 for the 529th to 601st layers. Here, the first layer refers to the layer position counted from the surface with the greater number of layers when the multilayer laminate film is divided into two equal thicknesses.

[0153] Feed block of Comparative Example 4: A 601-layer feed block (stacking device) (number of repeating units: 150, 151 A layers, 300 B layers, 150 C layers) designed so that the layer thicknesses of the A, B, and C layers change continuously from one surface layer to the opposite surface layer according to formula (A) so that the reflected wavelength at an incident angle of 10° is 580 nm to 1650 nm, and the stacking structure is (A layer / B layer / C layer / B layer)nA layers (n is an integer representing the number of repeating units). Feed block of Comparative Example 5: A 601-layer feed block (stacking device) (number of repeating units: 150, 151 A layers, 300 B layers, 150 C layers) designed so that the layer thicknesses of the A, B, and C layers change continuously from one surface layer to the opposite surface layer according to formula (A) so that the reflected wavelength at an incident angle of 10° is 850 nm to 2300 nm, and the stacking structure is (A layer / B layer / C layer / B layer)nA layers (n is an integer).

[0154] Feedblock of Example 11: A 601-layer feedblock (lamination device) (the number of repeating units is 150, with 151 A layers, 300 B layers, and 150 C layers) designed so that the layer thicknesses of the A, B, and C layers change continuously from one surface to the opposite surface according to formula (A) so that the reflected wavelength at an incident angle of 10° is 850 nm to 1750 nm, and the layer structure is (A layer / B layer / C layer / B layer)nA layers (n is an integer representing the number of repeating units), and the layer thicknesses of the A, B, and C layers are 150 A layers, 300 B layers, and 150 C layers. The layer thicknesses of the A, B, and C layers are 150 A layers, 300 B layers, and 150 C layers. ... B, C, and C layers are 0.7 for the 1st to 505th layers. The layer thicknesses of the 506th to 601st layers are 0.7 for the 506th to 601st layers. Here, the first layer refers to the layer position counted from the surface with the greater number of layers when the multilayer laminate film is divided into two equal thicknesses. Feedblock of Example 12: A 601-layer feedblock (lamination device) (the number of repeating units is 150, with 151 A layers, 300 B layers, and 150 C layers) designed so that the layer thicknesses of the A, B, and C layers change continuously from one surface to the opposite surface according to formula (A) so that the reflected wavelength at an incident angle of 10° is 850 nm to 1750 nm, and the layer structure is (A layer / B layer / C layer / B layer)nA layers (n is an integer representing the number of repeating units), and the layer thicknesses are 151 A layers, 300 B layers, and 150 C layers. The layer thicknesses of the first to 421st layers are the same as those of Example 1, and the layer thicknesses of the 422nd to 601st layers are 0.7. The first layer is the layer position counted from the surface with the greater number of layers when the multilayer laminate film is divided into two equal thicknesses.

[0155] Comparative Example 2: Resin A was used as the thermoplastic resin constituting Layer A, and Resin J was used as the thermoplastic resin constituting Layer C. Resins A and J were each melted at 280°C in an extruder and passed through five FSS-type leaf disc filters. Then, the resins were metered using a gear pump so that the discharge ratio (lamination ratio) was Layer A / Layer C = 1.2. The layers were laminated in a 401-layer feedblock (lamination device) (201 Layer A and 200 Layer C) designed so that the layer thicknesses of Layer A and Layer C continuously changed from one surface layer to the opposite surface layer according to formula (A) so that the reflected wavelength at an incident angle of 10° was 850 nm to 1200 nm, resulting in a layer structure of (Layer A / Layer C)nA layers (n is an integer representing the number of repeating units). The molten laminate was then fed into a T-die and formed into a sheet. It was then quenched and solidified on a casting drum maintained at a surface temperature of 25°C while an electrostatic voltage of 8 kV was applied by a wire, yielding an unstretched multilayer laminate film. Other than that, a multilayer laminate film having a thickness of 74 μm (thickness of both surface layers: 5 μm) was obtained in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0156] Comparative Example 3 A multilayer laminate film was obtained in the same manner as in Comparative Example 2 using an 801-layer feedblock (lamination device) (401 A layers and 400 C layers) designed so that the layer thicknesses of the A layers and C layers changed continuously from one surface layer to the opposite surface layer according to formula (A) so that the reflected wavelength of P waves at an incident angle of 60° would be 400 nm to 800 nm, and so that the laminate structure would be (A layers / C layers)nA layers (n is an integer representing the number of repeating units). The resin of each layer, the number of layers, the thickness of the surface layers, the overall thickness, the lamination ratio, and the film-forming conditions were as shown in Table 1. The evaluation results are shown in Table 2.

[0157] (Verification of the refractive index of layer B) For Examples 1 to 18, Comparative Example 1, and Comparative Examples 4 to 9, the verification of the refractive index of layer B of the multilayer laminate film in Section (18) was carried out, and the difference between the optical simulation results and the reflectance was ±3% or less in all cases. Therefore, the refractive index of layer B obtained in Section (17) was considered to be the refractive index of layer B of the multilayer laminate film.

[0158]

[0159] Since the multilayer laminated films of Comparative Examples 2 and 3 only had layers A and C, the lamination ratio was recorded as A / C in the A / B column.

[0160]

[0161] (Examples 19 to 39, Comparative Examples 9 to 20) Examples 19 to 39 and Comparative Examples 9 to 20 are examples and comparative examples of projection image display members equipped with multilayer laminate films. Regarding the production of laminates, laminates of the multilayer laminate film of Comparative Example 2 and the multilayer laminate film of Comparative Example 3 were produced. Each A4-sized film was laminated using an acrylic optical adhesive sheet with an adhesive layer thickness of 25 μm. For lamination, a roll laminator (MRK-600) manufactured by MCK Corporation was used. Next, in the production of projection image display members 1-18, 21-27, and 29-31, a 2 mm thick, A4-sized float glass plate and the A4-sized films and laminates of Examples 1-12 and Comparative Examples 1-6 were laminated using an acrylic optical adhesive sheet with an adhesive layer thickness of 25 μm to produce projection image display members having a float glass plate / 25 μm thick acrylic adhesive layer / film configuration, respectively, designated projection image display members 1-18, 21-27, 29, and 30. An MCK roll laminator (MRK-600) was used for lamination. Projection image display member 18, produced using the laminate, exhibited wrinkles and uneven distortion with a 3-4 mm period. On the other hand, no wrinkles or distortions were visible in projection image display members 1-17, 21-27, 29, and 31.

[0162] (Production of Projection Image Display Member 19) A laminated glass having the following configuration was produced using a 2 mm thick, A4-sized float glass plate, 0.76 mm thick PVB (polyvinyl butyral), and the multilayer laminate film of Example 1. Laminated glass configuration: float glass plate / PVB / multilayer laminate film of Example 1 / PVB / float glass plate. A Nisshinbo LAMINATOR 0303S laminating machine was used to produce the laminated glass. The laminated body was placed in the laminating machine, and a vacuum was applied at 100°C for 5 minutes, followed by a further vacuum application at 130°C for 5 minutes. The laminated glass was then pressure-bonded at 0.1 MPa for 60 minutes. (Production of Projection Image Display Member 28) A laminated glass was produced in the same manner as Projection Image Display Member 19, except that the multilayer laminate film of Example 13 was used instead of the multilayer laminate film of Example 1. (Production of Projection Image Display Member 20) A laminated glass having the following configuration was produced in the same manner as Projection Image Display Member 19. Laminated glass structure: float glass sheet / PVB / laminate / PVB / float glass sheet. Projection image display member 19 had slight uneven distortion, but no visible wrinkles. On the other hand, projection image display member 20 had large wrinkles and uneven distortion with a period of 1 to 2 mm.

[0163] The projection image display devices of Examples 19 to 39 and Comparative Examples 9 to 20 were evaluated using projection image display members 1 to 30 as shown in Table 3. Table 3 shows the combinations of the projection image display members and P-wave intensities used, as well as the evaluation results of the projection image display devices.

[0164]

[0165] The present invention provides a multilayer laminate film that is transparent and transmits visible light in the front direction, while also having a near-infrared reflecting function and a P-wave visible light reflecting function in an oblique direction. The multilayer laminate film of the present invention can be suitably used in projection image display members, projection image display devices using the projection image display members, transportation facilities and buildings using the projection image display devices, etc.

[0166] 1: Near-infrared reflective multilayer laminate film 2: Visible light P wave reflective multilayer laminate film 3: Laminate film 4: Multilayer laminate film 5: One of two different thermoplastic resin layers of a near-infrared reflective multilayer laminate film 6: The other of two different thermoplastic resin layers of a near-infrared reflective multilayer laminate film 7: One of two different thermoplastic resin layers of a visible light P wave reflective multilayer laminate film 8: The other of two different thermoplastic resin layers of a visible light P wave reflective multilayer laminate film 9: Layer A 10: Layer B 11: Layer C 12: Transparent adhesive 13: Visible light incident in the front direction 14: Near-infrared light 15: P wave in an oblique direction 16: Laminated glass (structure having a multilayer laminate film between glass panes) 17: Laminated glass (structure having a multilayer laminate film on the surface) 18: Transparent support (glass) 19: Adhesive layer 20: Reflectance of P wave 21: Reflectance of S wave 22: Refractive index (Naθ) of layer A at an incident angle θ 23: Refractive index (Ncθ) of layer C at incident angle θ 24: Refractive index (Nbθ) of layer B of multilayer laminate film (Example 1) at incident angle θ 25: Refractive index (Nbθ) of layer B of near-infrared reflective multilayer laminate film (Comparative Example 1) at incident angle θ 26: Average visible light reflectance of P wave of multilayer laminate film (Example 1) 27: Average visible light reflectance of P wave of near-infrared reflective multilayer laminate film (Comparative Example 1) 28: Thickness of layer A 29: Thickness of layer C 30: Thickness of layer B 31: Anti-reflection layer 32: Functional layer 33: Projected image display member 34: Background 35: Eye of user of projection image display device 36: Incident angle of projected image 37: Image projection device 38: Projected image 39: Conventional projected image display member 40: Light guiding member 41: Reflecting member

Claims

1. A multi-layer laminate film in which three or more types of resin layers are regularly arranged, and the dielectric constant of each layer at a loss energy of 2.5 eV obtained by electron energy loss spectroscopy (EELS measurement) is expressed as the dielectric constant X ｉ (i=1, 2, 3, . . . ), and the dielectric constant X ｉ A multilayer laminate film having all of the following (1) to (3), when the layers are arranged in descending order of thickness, namely, layer A, layer B, and layer C. (1) It has a repeating unit structure in which repeating units arranged in the order of layer A / layer B / layer C / layer B are laminated. (2) Within each of the repeating units, repeating units having a total layer thickness in the range of 250 nm to 630 nm account for 80% to 100% of all repeating units. (3) The layer A is a crystalline thermoplastic resin layer, and the layer B and the layer C are composed of a combination of amorphous thermoplastic resin layers.

2. The multilayer laminate film according to claim 1, wherein, in each repeating unit, the lamination ratio (A / B) of the A layer to the total thickness of the B layer and the lamination ratio (C / B) of the C layer to the total thickness of the B layer are within the range of 0.8 to 1.3, respectively, and the proportion of repeating units is 80% to 100% relative to all repeating units.

3. The dielectric constant at a loss energy of 2.5 eV obtained by electron energy loss spectroscopy (EELS measurement) is called the dielectric constant X ｉ When the dielectric constant X ｉ a repeat unit structure in which three types of resin layers (A layer, B layer, C layer) having different dielectric constants are arranged in the order of A layer / B layer / C layer / B layer, and the ratio of units having a total layer thickness in the repeat unit within the range of 250 nm to 630 nm is 80% to 100% of all repeat units, and in the repeat unit, the ratio of repeat units having a lamination ratio (A / B) of the A layer to the total thickness of the B layer and a lamination ratio (C / B) of the C layer to the total thickness of the B layer each within the range of 0.8 to 1.3 is 80% to 100% of all repeat units, and i In the above, the dielectric constant of the A layer is X Ａ , the dielectric constant of the B layer is X Ｂ and the dielectric constant of the C layer is X ｃ Then, X Ａ >X Ｂ >X Ｃ and having an average visible light reflectance of 10% or more and 99% or less for P waves when incident at an angle of 60° with respect to the normal to the film surface.

4. The multilayer laminate film according to any one of claims 1 to 3, wherein the number of units in the repeating unit whose total layer thickness is within the range of 250 nm or more and 630 nm or less is 15 or more and 2,500 or less.

5. The multi-layer laminate film according to claim 3 or 4, wherein the A layer is a crystalline thermoplastic resin layer, and the B layer and the C layer are a combination of amorphous thermoplastic resin layers.

6. The plane orientation coefficient of the A layer is 0.06 or more, and the dielectric constant X of the B layer is Ｂ 6. The multilayer laminate film according to claim 1, wherein a ratio of a difference between a dielectric constant in an in-plane direction and a dielectric constant in a perpendicular direction divided by a dielectric constant in the perpendicular direction is 10% or less.

7. The multi-layer laminate film according to any one of claims 1 to 6, wherein the chroma of transmitted light incident perpendicularly to the film surface is 10 or less.

8. The multi-layer laminate film according to any one of claims 1 to 7, which has a transmittance of visible light incident perpendicularly to the film surface of 70% or more and 100% or less.

9. The multilayer laminate film according to any one of claims 1 to 8, which has a reflectance of 40% or more over at least a wavelength of 100 nm in the range of 850 nm to 1600 nm when light is incident on the film surface at an angle of 10° with respect to the normal line of the film.

10. A multilayer laminate film according to any one of claims 1 to 9, which satisfies the relationship Rp20≦Rp40<Rp60 when the average reflectance when P waves in the visible light band are incident on the film surface at angles of 20°, 40°, and 60° with respect to the normal to the film surface is Rp20(%), Rp40(%), and Rp60(%), respectively.

11. The multilayer laminate film according to any one of claims 1 to 10, wherein the chroma of reflected light of a P wave incident at an angle of 60° to the normal to the film surface is 20 or less.

12. A multilayer laminate film according to any one of claims 1 to 11, in which when the average reflectance is Rp60 (%) when P waves in the visible light band are incident on the film surface at an angle of 60° with respect to the normal to the film surface, the azimuth angle variation of Rp60 is 10% or less.

13. The multilayer laminate film according to any one of claims 1 to 12, wherein, in all layers in the multilayer laminate film having a layer thickness of 1,000 nm or less, the ratio of the total layer thickness (DA) of the A layers to the total thickness (DB) of the B layers: T (T=DA / DB) satisfies 0.80≦T≦1.00, and the ratio of the total thickness (DC) of the C layers to the total thickness of the B layers: S (S=DC / DB) satisfies 1.10≦S≦1.

30.

14. A projection image display member, comprising the multilayer laminate film according to any one of claims 1 to 13, located on at least one surface of a transparent support or between transparent members.

15. The projection image display member according to claim 14, wherein the thickness of said projection image display member is 0.5 mm or more and 7 mm or less, and said transparent support includes at least any one of glass, polycarbonate resin, and acrylic resin.

16. A projection image display device comprising the projection image display member according to claim 14 or 15, and a light source for irradiating light onto the display surface.

17. A projection image display device as described in claim 15, wherein the intensity of P waves (P wave intensity / (P wave intensity+S wave intensity)) accounts for 51% or more of the intensity of the image incident on the display surface of the projection image display member.

18. The projection image display device according to claim 16 or 17, which is used by being worn on a user's head.

19. A means of transportation comprising the projection image display device according to claim 16 or 17, wherein at least a portion of the light emitted from the light source toward the projection image display member is incident on the projection image display member at an angle of 50° to 75° with respect to the normal to the projection image display member.

20. The transportation means according to claim 19, comprising a projection image display device, the projection image display member having a center with a horizontal radius of curvature of 1 m or more and 8 m or less.

21. A building comprising the projection image display device according to claim 16 or 17.

Images