JP2019518244A - Adjustable insulation window - Google Patents

Abstract

An adjustable thermal insulation window is provided, the transparency of which can be adjusted by different voltages. An adjustable heat insulating window according to the present invention is provided between a first transparent substrate (10), a second transparent substrate (20), and the first transparent substrate (10) and the second transparent substrate (20). And the liquid crystal composition includes a plurality of liquid crystal molecules 31 having negative dielectric anisotropy, a dichroic dye 32 having a visible light absorption wavelength of 400 nm to 780 nm, and an ionic salt And 33. [Selected figure] Figure 1

Description

  The present invention relates to adjustable thermal insulation windows, and in particular to windows with adjustable transparency and thermal insulation.

  In addition to the high transmission of common glass, it is also important at the same time to have thermal insulation and privacy protection in smart type window applications.

  In a conventional smart type window, when twisted nematic (TN) liquid crystal is used, liquid crystal alignment is usually performed by a polarizing plate. For this reason, while the light transmittance with which a window is provided falls, the cost which provides a polarizing plate will generate | occur | produce separately.

  In optical switch technology developed in recent years, a technology for switching between a high transparency state and an absorption state, or a high transparency state and a scattering state is often applied to a smart type window, for example, electrochromic (electrochromic) ), Photochromic (Photochromic), suspended particle device (Suspended Particle Device), polymer dispersed liquid crystal (Polymer Dispersed Liquid Crystal), and the like. However, such techniques can not be equipped with multi-functional switching characteristics to switch between high transparency, high absorption and confusion states, since only the most two states are switched.

  Therefore, in order to solve the problems of the prior art, it is necessary to provide an adjustable heat insulating window which can switch between a high transparency state, a high absorption state and a confusion state.

  An object of the present invention is to provide an adjustable heat insulating window which can utilize a liquid crystal composition which is converted into three states such as transparency, absorption and shielding by different voltages. The liquid crystal composition contains a negative liquid crystal, a dichroic dye and an ionic salt, and when no voltage is supplied, the liquid crystal composition becomes transparent and when a low range voltage is supplied, the liquid crystal composition When the liquid crystal composition is in the absorbing state, it has a certain heat insulating effect, and when a high range of voltage is provided, the liquid crystal composition is in the atomization shielding state and has the heat insulating effect. Such liquid crystal compositions can be applied to automobiles or buildings. In addition, when the voltage is not supplied, the visible light transmittance of the liquid crystal composition is larger than 65%, so that the liquid crystal composition can automatically return to the transparent state at the time of an unintended power failure, and the safety when running the vehicle It can be enhanced. The structure of the adjustable heat insulating window of the present invention is simple, and it is possible to increase the light transmittance in the transparent state without providing a separate polarizing film, and it is possible to omit the cost and assembly of the polarizing film.

To achieve the above object, according to an aspect of the present invention, a first transparent substrate including a first electrode, a second transparent substrate including a second electrode, the first transparent substrate, and the second transparent substrate And a heat insulating layer containing a liquid crystal composition, the liquid crystal composition comprising a plurality of liquid crystal molecules having negative dielectric anisotropy, and a visible light absorption wavelength of 400 nm to 780 nm. A tunable thermal insulation window is provided that includes a color dye and an ionic salt.
In the embodiment of the present invention, the liquid crystal molecules are nematic liquid crystals.
In the embodiment of the present invention, the ionic salt is water soluble.
In the embodiment of the present invention, the ionic salt is sodium chloride, calcium sulfate, ammonium sulfate, sodium carbonate, sodium bicarbonate, potassium nitrate, or tetrabutylammonium tetrafluoroborate (TBATFB).
Further, in the aspect of the present invention, when a voltage is supplied to the first electrode and the second electrode, the light transmittance of the heat insulating layer is reduced and part of visible light is absorbed.
In the embodiment of the present invention, when the voltage is smaller than 10 V, the visible light transmittance of the heat insulating layer is 30% to 65%.
Moreover, in the aspect of this invention, when the said voltage becomes larger than 20 V, the visible light transmittance | permeability of the said heat insulation layer is smaller than 5%.
In the embodiment of the present invention, when the voltage is smaller than 10 V, the near infrared transmittance of the heat insulating layer is larger than 85%.
In the embodiment of the present invention, when the voltage is greater than 20 V, the near infrared transmittance of the heat insulating layer is less than 25%.
Further, in the aspect of the present invention, when the voltage is not supplied to the first electrode and the second electrode, the heat insulating layer is in a transparent state.

FIG. 5 is a schematic view of the adjustable heat insulating window according to the embodiment of the present invention in a transparent state. FIG. 6 is a schematic view of the adjustable insulation window according to an embodiment of the present invention in an absorbing state. FIG. 5 is a schematic view of the adjustable heat insulating window according to the embodiment of the present invention in a shielding state. FIG. 5 shows the change in visible light transmittance and near infrared transmittance of the adjustable thermal insulation window according to an embodiment of the present invention at different voltages. FIG. 6 shows the variation of the transmission of each wavelength of the tunable thermal insulation window according to an embodiment of the present invention in the transparent state, the absorption state and the shielding state.

  DETAILED DESCRIPTION In order to make the aforementioned objects, other objects, features and advantages of the present invention more comprehensible, preferred embodiments of the present invention will be described in detail with reference to the drawings. Also, the directional terms to which the present invention refers, eg, top, bottom, top, bottom, front, back, left, right, inside, outside, side, perimeter, center, horizontal, vertical, vertical, axial The radial direction, the top layer or the bottom layer etc. is only in the direction shown in the drawings. In addition, the singular forms “one,” “one,” and “the” as referred to in the present invention include a plurality, except those clearly defined in the upper and lower sentences. Unless specifically stated otherwise, for numerical ranges (eg, 10% to 11% of A), including upper and lower limits (ie, 10% A A% 11%) and lower limits for numerical ranges (E.g. B less than 0.2% or B less than or equal to 0.2%), the lower limit is 0 (i.e. 0% <B <0.2%). The above terms are for the purpose of describing and understanding the present invention, but not for limiting the present invention.

  The adjustable heat insulating window according to an embodiment of the present invention includes a first transparent substrate 10 including a first electrode (not shown), a second transparent substrate 20 including a second electrode (not shown), and the first transparent substrate. And a heat insulating layer 30 provided between the substrate 10 and the second transparent substrate 20. The first transparent substrate 10 and the second transparent substrate 20 are made of various types of glass substrates generally used. The first and second electrodes are made of, for example, indium tin oxide (ITO) generally used for a transparent electrode of a display.

The heat insulating layer 30 includes a liquid crystal composition. The liquid crystal composition includes a plurality of liquid crystal molecules 31, a dichroic dye 32 and an ionic salt 33. The liquid crystal molecules 31 preferably have negative dielectric anisotropy. In the embodiment of the present invention, the liquid crystal molecule 31 is a nematic liquid crystal, and examples thereof include nematic liquid crystal MLC2081, MLC2078, ZLI-2806 or ZLI2293 manufactured by Merck, but the present invention is not limited thereto. The visible light absorption wavelength of the dichroic dye 32 is preferably 400 nm to 780 nm, and more preferably 480 nm to 650 nm, but is not limited thereto. The dichroic dye 32 is made of, for example, S428 (manufactured by Mithui). The ionic salt 33 is water soluble and can be dissociated into negative ions 33a and positive ions 33b. The ionic salt 33 is sodium chloride (NaCL), calcium sulfate (CaSO ₄ ), ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), sodium carbonate (Na ₂ CO ₃ ), sodium bicarbonate (NaHCO ₃ ), potassium nitrate ( KNO ₃ ), or tetrabutylammonium tetrafluoroborate (
, TBATFB, tetrabutylammonium tetrafluoroborate). In the embodiment of the present invention, the weight ratio of the liquid crystal molecule 31, the dichroic dye 32, and the ionic salt 33 may be, for example, (90 to 99): (0.5 to 5): (0.0002 to 5), preferably 98: 1: 1, but is not limited thereto.

  When the voltage V is supplied to the first electrode and the second electrode, the heat insulating layer 30 reduces its light transmittance and absorbs a part of visible light. In the embodiment of the present invention, when the voltage V is smaller than 10 V, the visible light transmittance of the heat insulating layer 30 is 30% to 65%, for example, 35%, 45%, 50% or 60%. Although there are, it is not limited to these. When the voltage V is larger than 20 V, the visible light transmittance of the heat insulating layer 30 is 5% or less, for example, 5%, 4%, 3%, 2%, 1% or 0.5%. However, it is not limited to these. When the voltage V is smaller than 10 V, the near infrared transmittance of the heat insulating layer 30 is 85% or more, for example, 85%, 86%, 87% or 88%, but is limited thereto is not. When the voltage V is greater than 20 V, the near infrared transmittance of the heat insulating layer 30 is less than 25%, for example, 23%, 21%, 19%, 17% or 15%, but is limited thereto It is not something to be done. In the embodiment of the present invention, when the voltage is not supplied to the first electrode and the second electrode (ie, the voltage is 0 V), the heat insulating layer 30 is in the visually transparent state, and the visible light is about 65%. It has a transmittance. Therefore, the adjustable heat insulating window of the present invention is in a transparent state when not energized, and can be ensured to return to the transparent state upon an unintended power failure, thereby enhancing the safety of use when applied to automobile glass be able to.

  FIG. 1 is a schematic view in which an adjustable heat insulating window according to an embodiment of the present invention is in a transparent state. The liquid crystal molecules 31 are negative liquid crystals, and when no voltage is applied, the liquid crystal molecules 31 are orthogonal to the first transparent substrate 10 and the second transparent substrate 20, so that the light source L1 is the adjustable heat insulation It can pass through the window and allow the user to see the outside scenery.

  FIG. 2 is a schematic view of the adjustable heat insulating window according to the embodiment of the present invention in an absorbing state. When a low frequency AC voltage is applied, since the liquid crystal molecules 31 are negative liquid crystals, the major axes of the liquid crystal molecules 31 are parallel to the first transparent substrate 10 and the second transparent substrate 20 by controlling the electric field. At this time, the light source L1 is affected by the dichroic dye 32, and a part of the wavelength is absorbed by the dichroic dye 32, whereby a dark color and a low transparency state are obtained. Together with the thermal insulation effect. In practical application, the user can view the outside scene from the inside of the adjustable insulation window, and the discomfort caused by the radiation such as the sun is avoided. The voltage is 10 V or less, for example, 2 V, 3 V, 4 V, 5 V, 6 V, 7 V or 8 V, but is not limited thereto.

  FIG. 3 is a schematic view of the adjustable heat insulating window according to the embodiment of the present invention in a shielding state. When the voltage is continuously increased, the ions are actively disturbed, the liquid crystal molecules 31 are affected, the arrangement is disturbed, the light source L1 is disturbed, and additionally, the dichroic dye 32 is By absorbing a part of the visible light wavelength of the light source L1, it becomes a dark atomization shielding state and can shield the light source L1, and when applied to automobile glass, it has a good privacy protection function and heat insulation effect You can have The voltage is, for example, 10 V or more, and preferably 20 V or more, but is not limited thereto.

  FIG. 4 is a diagram showing changes in visible light (480 nm to 650 nm) transmittance and near infrared (700 nm to 750 nm) transmittance of the adjustable heat insulating window at different voltages. As shown in FIG. 4, in the region A, when no voltage is applied, both the visible light transmittance and the near infrared transmittance are in a state of high, which is about 65% and 80%, respectively. When a small voltage between about 2 V and 8 V is applied (region B), it can be seen that the visible light transmittance is significantly reduced, and it is about 30%, while the near infrared transmittance is maintained at 80%. Thus, although a part of visible light is absorbed by the dichroic dye 32, a certain degree of translucency can be maintained, and since visible light is absorbed, it has a heat insulating effect. When the voltage is increased to 20 V (C region), both the visible light transmittance and the near infrared transmittance are significantly reduced, and excluding the confusion of the light source due to the arrangement of the liquid crystal molecules 31, the dichroic dye 32 is visible. By absorbing part of the light, the effects of confusion and insulation are achieved.

  FIG. 5 is a view showing the visible light transmittance of each wavelength in the transparent state (curve A), the absorption state (curve B) and the shielding state (curve C). As shown in FIG. 5, the A and B curves have low light transmission in the low wavelength region (about 650 nm or less), and the adjustable heat insulating window blocks the energy of a portion of visible light, thereby providing thermal insulation. It indicates that it has a function. From the difference in transmittance between the A and B curves, the absorption state can be represented visually as being between the shielding state and the transparent state, which is a semi-transparent state. Since the C curve has a transmittance close to 0% for the A and B curves, a good privacy shielding effect can be achieved.

  Although the present invention has been described by the above embodiments, the above embodiments are merely examples for carrying out the present invention, and do not limit the scope of the present invention. Further, modifications and the like included in the claims fall within the scope of the present invention.

Claims (8)

A first transparent substrate including a first electrode;
A second transparent substrate including a second electrode;
A thermal insulation layer provided between the first transparent substrate and the second transparent substrate and containing a liquid crystal composition,
The liquid crystal composition is
A plurality of liquid crystal molecules having negative dielectric anisotropy;
A dichroic dye having a visible light absorption wavelength of 400 nm to 780 nm;
And ionic salts, and
The adjustable heat insulating window, wherein the heat insulating layer is in a transparent state when no voltage is supplied to the first electrode and the second electrode.   The adjustable heat insulating window according to claim 1, wherein the liquid crystal molecules are nematic liquid crystals.   The adjustable thermal insulation window of claim 1, wherein the ionic salt is water soluble.   The tunable thermal insulating window of claim 1, wherein the ionic salt is sodium chloride, calcium sulfate, ammonium sulfate, sodium carbonate, sodium bicarbonate, potassium nitrate, or tetrabutylammonium tetrafluoroborate.   The adjustable thermal insulation window according to claim 1, wherein when the voltage is supplied to the first electrode and the second electrode, the thermal insulation layer reduces its light transmittance and absorbs a part of visible light. .   The tunable insulation window according to claim 5, wherein the visible light transmission of the thermal insulation layer is 30% to 65% when the voltage is less than 10V.   The tunable insulation window according to claim 5, wherein the visible light transmittance of the thermal insulation layer is less than 5% when the voltage is greater than 20V.   The tunable insulation window according to claim 5, wherein the near infrared transmission of the thermal insulation layer is less than 25% when the voltage is greater than 20V.