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JP-2026076259-A - Dimming sheets and dimming devices

JP2026076259AJP 2026076259 AJP2026076259 AJP 2026076259AJP-2026076259-A

Abstract

[Problem] The design of the dimming sheet can be improved. [Solution] The thickness of the dimming layer 11 at multiple measurement positions is within the range of 0.8 times or more and 1.2 times the median thickness. The change in linear transmittance of visible light is measured when the driving voltage applied to each transparent electrode layer 12A, 12B is changed, and among the characteristic curves obtained, the lower limit of the driving voltage in the range where the rate of change of linear transmittance is 0.5%/V or more is defined as the first voltage Va, the upper limit as the second voltage Vb, and the midpoint between the first voltage Va and the second voltage Vb is defined as Vm. The variation of the midpoint obtained from the characteristic curve of each measurement position, where the difference between the minimum value Vmin and the maximum value Vmax is divided by the average value Vavr of the midpoint Vm, is 35.0% or less. [Selection Diagram] Figure 8

Inventors

  • ▲高▼橋 裕介

Assignees

  • ＴＯＰＰＡＮホールディングス株式会社

Dates

Publication Date
20260511
Application Date
20260122
Priority Date
20210305

Claims (5)

  1. A light-adjusting layer containing a resin layer and oriented particles, A pair of transparent electrode layers sandwiching the light-adjusting layer, Equipped with, The light-adjusting layer has a structure in which the oriented particles are contained in a plurality of voids dispersed in the resin layer. When the driving voltage applied to the transparent electrode layer is changed, the change in the linear transmittance of visible light is measured, and among the characteristic curves obtained, the lower limit of the driving voltage in the range where the absolute value of the rate of change of the linear transmittance is 0.5%/V or more is defined as the first voltage Va, the upper limit as the second voltage Vb, and the midpoint between the first voltage Va and the second voltage Vb is defined as Vm. A dimmable sheet in which the variation of the intermediate value Vm obtained from the characteristic curves at multiple measurement positions, calculated by dividing the difference between the minimum value Vmin and the maximum value Vmax by the average value Vavr of the intermediate value Vm, is 35.0% or less ({(Vmax - Vmin) / Vavr} × 100).
  2. The light-adjusting layer includes a spacer that controls the gap between the pair of transparent electrode layers. The dimming sheet according to claim 1, wherein when the dimming layer is observed from the contact surface with the transparent electrode layer, the ratio of the total area occupied by the plurality of spacers to the total area of the dimming layer is 0.9% or more and 30.0% or less.
  3. The dimming sheet according to claim 1 or 2, wherein the diameter of the void is 0.4 μm or more and 2.2 μm or less.
  4. The dimming sheet according to any one of claims 1 to 3, wherein the difference between the first voltage Va and the second voltage Vb is 22V or less.
  5. A dimmable sheet whose linear transmittance changes according to the driving voltage, The system includes a drive unit that controls the drive voltage applied to the dimming sheet, The aforementioned dimming sheet is A light-adjusting layer containing a resin layer and oriented particles, A pair of transparent electrode layers sandwiching the light-adjusting layer, Equipped with, The light-adjusting layer has a structure in which the oriented particles are contained in a plurality of voids dispersed in the resin layer. When the driving voltage applied to the transparent electrode layer is changed, the change in the linear transmittance of visible light is measured, and among the characteristic curves obtained, the lower limit of the driving voltage in the range where the absolute value of the rate of change of the linear transmittance is 0.5%/V or more is defined as the first voltage Va, the upper limit as the second voltage Vb, and the midpoint between the first voltage Va and the second voltage Vb is defined as Vm. Of the intermediate values Vm obtained from the characteristic curves at multiple measurement locations, the variation of the intermediate values {(Vmax - Vmin) / Vavr} × 100, obtained by dividing the difference between the minimum value Vmin and the maximum value Vmax by the average value Vavr of the intermediate values Vm, is 35.0% or less. The aforementioned drive unit is A dimming device that switches between a first mode in which the drive voltage is not applied, a second mode in which a voltage of the second voltage Vb or higher is applied, and a third mode in which the linear transmittance of the dimming sheet is set to a linear transmittance between the linear transmittance in the first mode and the linear transmittance in the second mode by applying a voltage between the first voltage Va and the second voltage Vb.

Description

This disclosure relates to a dimmable sheet and dimming device with variable linear transmittance. The dimming sheet comprises a dimming layer containing a liquid crystal composition and a pair of transparent electrode layers sandwiching the dimming layer (see, for example, Patent Document 1). The dimming device comprises the dimming sheet and a drive unit that controls the application of a driving voltage to the pair of transparent electrode layers. The linear transmittance of the dimming sheet changes as the orientation of the liquid crystal molecules changes according to the potential difference between the pair of transparent electrode layers. The dimming sheet can be attached to building materials such as window glass or glass walls, or to car windows, and function as a partition member separating two spaces. Japanese Patent Publication No. 2017-187775 Figure 1 is a cross-sectional view showing a normal type of dimmable sheet.Figure 2 is a plan view showing the dimming sheet in opaque mode.Figure 3 is a plan view showing the dimming sheet in transparent mode.Figure 4 is a plan view showing the dimming sheet in mid-tone mode.Figure 5 is a cross-sectional view showing a dimming sheet in opaque mode.Figure 6 is a cross-sectional view showing a dimming sheet in transparent mode.Figure 7 is a plan view showing a reference example of a dimming sheet that exhibits halftones.Figure 8 is a graph showing the voltage-linear transmittance curve of a dimmable sheet as an example.Figure 9 is a graph showing the voltage-linear transmittance curve of the dimming sheet.Figure 10 is a graph showing the voltage-linear transmittance curve of a dimmable sheet as an example.Figure 11 is a cross-sectional view showing a reverse-type dimming sheet.Figure 12 is a table showing the evaluation results for Examples 1 to 4 and Comparative Examples 1 and 2.Figure 13 is a graph showing the voltage-linear transmittance curve of the dimming sheet of Example 1.Figure 14 is a graph showing the voltage-linear transmittance curve of the dimming sheet of Example 2.Figure 15 is a graph showing the voltage-linear transmittance curve of the dimming sheet of Example 3.Figure 16 is a graph showing the voltage-linear transmittance curve of the dimming sheet of Example 4.Figure 17 is a graph showing the voltage-linear transmittance curve of the dimming sheet of Comparative Example 1.Figure 18 is a graph showing the voltage-linear transmittance curve of the dimming sheet of Comparative Example 2.Figure 19 is an electron microscope image showing the light-adjusting layer of the light-adjusting sheet of Example 1.Figure 20 is an electron microscope image showing the light-adjusting layer of the light-adjusting sheet of Example 2.Figure 21 is an electron microscope image showing the light-adjusting layer of the light-adjusting sheet of Example 3.Figure 22 is an electron microscope image showing the light-adjusting layer of the light-adjusting sheet of Example 4.Figure 23 is an electron microscope image showing the light-adjusting layer of the light-adjusting sheet of Comparative Example 1.Figure 24 is an electron microscope image showing the light-adjusting layer of the light-adjusting sheet of Comparative Example 2. An embodiment of a dimming sheet and a dimming device will be described with reference to the drawings. [Basic structure of a dimmer] The basic structure of the dimming sheet and dimming device will be explained with reference to Figure 1. As shown in Figure 1, the dimming device 1 comprises a dimming sheet 10 and a drive unit 20 that controls the application of a drive voltage to the dimming sheet 10. The dimming sheet 10 may have a normal type structure in which the linear transmittance of visible light is high when energized and low when not energized. The dimming sheet 10 may have a reverse type structure in which the linear transmittance is low when energized and high when not energized. This embodiment will primarily describe the normal type of dimming sheet 10N. Furthermore, components common to both the normal and reverse types will simply be described as the dimming sheet 10. Linear transmittance T represents the transmittance of incident light parallel to the normal direction of the surface of the dimming sheet 100, and is also called parallel line transmittance. The normal type dimming sheet 10N comprises a dimming layer 11, a pair of transparent electrode layers, a first transparent electrode layer 12A and a second transparent electrode layer 12B, and a pair of transparent support layers, a first transparent support layer 13A and a second transparent support layer 13B. The first transparent electrode layer 12A and the second transparent electrode layer 12B sandwich the dimming layer 11. The first transparent support layer 13A and the second transparent support layer 13B sandwich the dimming layer 11, the first transparent electrode layer 12A, and the second transparent electrode layer 12B. The dimming layer 11 is located betw