Multilayer laminated film and projected image display member
A multilayer laminated film and a projected image display member are provided that are capable of reducing a luminance difference in an image due to a difference in projection angle when used in a projection member of an augmented reality device or the like, where the multilayer laminated film is obtained by alternately laminating 51 layers or more of a plurality of different thermoplastic resin layers, in which a transmittance of visible light perpendicularly incident on a surface of the multilayer laminated film is 50% or more and 100% or less, and when average reflectances of P-polarized wave at the time of visible light being incident on the surface of the multilayer laminated film are denoted as Rp20(%), Rp30(%), Rp40(%), Rp50(%), Rp60(%), and Rp70(%).
1 . A multilayer laminated film obtained by alternately laminating 51 layers or more of a plurality of different thermoplastic resin layers,
wherein the multilayer laminated film has a configuration in which a layer (layer A) composed of a first thermoplastic resin and a layer (layer B) composed of a second thermoplastic resin are alternately laminated, the first thermoplastic resin containing a crystalline polyester as a main component, and the second thermoplastic resin containing a polyester including a structure derived from naphthalene dicarboxylic acid as a main component,
wherein a transmittance of visible light perpendicularly incident on a surface of the multilayer laminated film is 50% or more and 100% or less, and when average reflectances of P-polarized wave at the time of visible light being incident on the surface of the multilayer laminated film such that angles formed with a normal of the surface are 20°, 30°, 40°, 50°, 60°, and 70° are denoted as Rp20(%), Rp30(%), Rp40(%), Rp50(%), Rp60(%), and Rp70(%) in this order, standard deviations of the Rp20, the Rp30, the Rp40, and the Rp50 are 5% or less and the Rp60 and the Rp70 are 3% or more and 50% or less, and
where the Rp20(%), the Rp30(%), the Rp40(%), the Rp50(%), the Rp60(%), and the Rp70(%) are average values when reflectance of P-polarized wave in a wavelength range of 400 nm to 700 nm at each incident angle θ of 20°, 30°, 40°, 50°, 60°, and 70° is measured in increments of 1 nm using a spectrophotometer.
2 . The multilayer laminated film according to claim 1 , wherein a minimum value of each of the Rp20, the Rp30, the Rp40, the Rp50, the Rp60, and the Rp70 is 3% or more and 50% or less.
3 . The multilayer laminated film according to claim 1 , wherein at least one of the Rp30, the Rp40, and the Rp50 among the Rp20, the Rp30, the Rp40, the Rp50, the Rp60, and the Rp70 takes a minimum value.
4 . The multilayer laminated film according to claim 1 , wherein when the multilayer laminated film is measured by differential scanning calorimetry (DSC), Tm−T*>27 (° C.) is satisfied where in a DSC 1st curve obtained by raising a temperature from 25° C. to 300° C. at 20° C./min, a melting peak temperature at which an absolute value of a quantity of absorption heat is maximized is denoted as Tm (° C.) and a temperature determined by the following measurement method is denoted as T* (° C.):
the measurement method of T* is as follows:
T* is determined by the following (1) and (2),
(1) a plurality of intersections of a temperature differential curve A(T) and a straight line A′(T)=0.2Amin in a range of Tmin (° C.) or less are defined as Tn (° C.) in the order of lower temperature where a temperature differential curve of the DSC 1st curve is denoted as A(T)=dDSC/dT (mW/° C.), a minimum value of A(T) in a temperature range of 150 (° C.) to Tm (° C.) in a graph of the temperature differential curve A(T) is denoted as Amin, and a temperature at that time is denoted as Tmin (° C.), and
(2) among Tn (° C.) satisfying (1), Tn (° C.) taking a minimum temperature among Tn (° C.) satisfying A(T)<0.2Amin at all times in a temperature range of Tn to Tn+5° C. is defined as T* (° C.).
5 . The multilayer laminated film according to claim 4 , wherein in the temperature differential curve A(T), a maximum value in a range of 150 (° C.) to Tm (° C.) is 0.040 or less.
6 . The multilayer laminated film according to claim 1 , wherein saturation of reflected light when the P-polarized wave is incident on the surface of the multilayer laminated film such that the angle formed with the normal of the surface is 60° is 20 or less.
7 . The multilayer laminated film according to claim 1 , wherein in-plane azimuth angle variation of the reflectance Rp60 when the P-polarized wave is incident on the surface of the multilayer laminated film such that the angle formed with the normal of the surface is 60° is 5% or less.
8 . The multilayer laminated film according to claim 1 , wherein the second thermoplastic resin includes a structure derived from an alkylene glycol having a number average molecular weight of 200 or more and 2000 or less.
9 . The multilayer laminated film according to claim 1 , wherein the multilayer laminated film has a melting point, two or more melting peaks indicating a fusion enthalpy (ΔHm) of 3 J/g or more by differential scanning calorimetry (DSC) are present, and a melting peak of less than 3 J/g is further present on a lower temperature side than the melting peaks indicating a fusion enthalpy of 3 J/g or more.
10 . A projected image display member comprising the multilayer laminated film according to claim 1 laminated between at least two transparent members.
11 . A projected image display member comprising the multilayer laminated film according to claim 1 laminated on at least one surface of a transparent member.
12 . An augmented reality device comprising the projected image display member according to claim 11 .
13 . An augmented reality device comprising the multilayer laminated film according to claim 1 .
14 . The augmented reality device according to claim 13 , which is used by being worn on a user's head.
15 . A projected image display member comprising a multilayer laminated film obtained by alternately laminating 51 layers or more of a plurality of different thermoplastic resin layers, wherein the multilayer laminated film has a configuration in which a layer (layer A) composed of a first thermoplastic resin and a layer (layer B) composed of a second thermoplastic resin are alternately laminated, the first thermoplastic resin containing a crystalline polyester as a main component, and the second thermoplastic resin containing a polyester including a structure derived from naphthalene dicarboxylic acid as a main component,
wherein a transmittance of visible light perpendicularly incident on a surface of the projected image display member is 50% or more and 100% or less, and when reflectances of P-polarized wave at the time of visible light being incident on the surface of the projected image display member such that angles formed with a normal of the surface are 20°, 30°, 40°, 50°, 60°, and 70° are denoted as Rp20(%), Rp30(%), Rp40(%), Rp50(%), Rp60(%), and Rp70(%) in this order, standard deviations of the Rp20, the Rp30, the Rp40, and the Rp50 are 5% or less, the Rp60 and the Rp70 are 3% or more and 50% or less, a minimum value of the Rp20 to the Rp70 is 3% or more, and saturation of reflected light when the P-polarized wave is incident on the surface of the projected image display member such that the angle formed with the normal of the surface is 60° is 20 or less,
where the Rp20(%), the Rp30(%), the Rp40(%), the Rp50(%), the Rp60(%), and the Rp70(%) are average values when reflectance of P-polarized wave in a wavelength range of 400 nm to 700 nm at each incident angle θ of 20°, 30°, 40°, 50°, 60°, and 70° is measured in increments of 1 nm using a spectrophotometer.
16 . The projected image display member according to claim 15 , wherein at least one of the Rp30, the Rp40, and the Rp50 among the Rp20, the Rp30, the Rp40, the Rp50, the Rp60, and the Rp70 takes a minimum value.
17 . The projected image display member according to claim 15 , wherein azimuth angle variation of reflectance when the P-polarized wave is incident on the surface of the projected image display member such that the angle formed with the normal of the surface is 60° is 5% or less.