KR102699962B1 - Heat shielding film and variable window including the same - Google Patents

Abstract

The present invention relates to a heat-insulating film, and more specifically, to a heat-insulating film having a remarkably excellent heat-insulating function, the physical properties of which can be changed depending on the application of power, and which exhibits excellent invisibility when power is applied and excellent visibility when power is not applied, and a variable window including the same.

Description

Heat shielding film and variable window including the same {Heat shielding film and variable window including the same}

The present invention relates to a heat-insulating film, and more specifically, to a heat-insulating film having a remarkably excellent heat-insulating function, the physical properties of which can be changed depending on the application of power, and which exhibits excellent invisibility when power is applied and excellent visibility when power is not applied, and a variable window including the same.

Recently, as interest in the environment and energy has increased, the demand for energy-saving industrial products has increased, and as one of them, the heat-blocking effect of shielding materials such as glass applied to houses, buildings, and automobiles is required. In general, in the case of buildings, the cause of more than 35% of building energy loss is the window performance of the building, and if the window performance is reduced, the cooling/heating air conditioning efficiency of the building may also be reduced.

In order to solve these problems, colored and vacuum-coated plastic films have been applied to shielding materials such as glass used in houses, buildings, and automobiles in the past. However, colored films generally do not block near-infrared solar energy, and thus are not effective as films for the purpose of heat blocking. In addition, the colored films often have a problem of fading when exposed to sunlight, and thus have a short service life and problems of increased costs due to frequent replacement. Furthermore, when the colored film is made of multiple dyes, the degree of fading due to sunlight varies depending on the type of dye, and thus the shielding material such as glass to which the film is attached has a problem of causing spots or increased turbidity, thereby lowering the aesthetic appeal in terms of appearance.

Accordingly, there is an urgent need to develop a heat-insulating film that has significantly superior heat-insulating function, can change its properties depending on the power supply, exhibits excellent invisibility when power is supplied, and exhibits excellent visibility when power is not supplied.

KR 10-0753917 B1(2007.08.24)

The present invention has been made to solve the above-described problems, and the purpose of the present invention is to provide a heat-insulating film having a remarkably excellent heat-insulating function, the physical properties of which can be changed depending on the application of power, and which exhibits excellent invisibility when power is applied and excellent visibility when power is not applied, and a variable window including the same.

In order to solve the above-described problem, the present invention provides a heat-insulating film including a liquid crystal part including an electrode layer, a heat-insulating electrode layer, and a liquid crystal layer interposed between the electrode layer and the heat-insulating electrode layer and having alignment films disposed on both surfaces; and a substrate part provided on one or both surfaces of the liquid crystal part; and satisfying both of the following conditions (1) and (2).

(1) A1: A2 is 1: 0.0032 ~ 0.26

(2) B1 is 3 to 35 and B2 is 0.3 to 8

(3) C1: C2 is 1:5.5 ~ 200

At this time, A1 represents the average transmittance (%) measured every 10 nm at a wavelength of 380 to 780 nm, B1 represents the average transmittance (%) measured every 50 nm at a wavelength of 350 to 2100 nm, C1 represents turbidity (%), A2 represents the average transmittance (%) measured every 10 nm at a wavelength of 380 to 780 nm by applying a voltage of 60 V, B2 represents the average transmittance (%) measured every 50 nm at a wavelength of 350 to 2100 nm by applying a voltage of 60 V, and C2 represents turbidity (%) measured by applying a voltage of 60 V.

In addition, the present invention provides a heat-insulating film including a liquid crystal part including an electrode layer, a heat-insulating electrode layer, and a liquid crystal layer interposed between the electrode layer and the heat-insulating electrode layer; and a substrate part provided on one or both sides of the liquid crystal part, wherein the heat-insulating film has an average transmittance of 3 to 35% measured every 50 nm at a wavelength of 350 to 2100 nm and an average reflectance of 33 to 47% measured every 50 nm at a wavelength of 350 to 2100 nm.

According to one embodiment of the present invention, all of the following conditions (1) to (3) can be satisfied.

(1) A1: A2 is 1: 0.0055 ~ 0.19

(2) B1 is 4 to 33 and B2 is 0.5 to 6.5

(3) C1:C2 is 1:6.6 ~ 99.6.

Additionally, the average transmittance measured every 10 nm at a wavelength of 380 to 780 nm can be 60 to 90%, and the turbidity can be 0.5 to 15%.

Additionally, the average transmittance measured at every 10 nm at a wavelength of 380 to 780 nm by applying a voltage of 60 V can be 0.3 to 15%, and the turbidity can be 85 to 99.7%.

Additionally, the heat-insulating electrode layer may include at least two metal-derived layers.

In addition, the liquid crystal layer may have a thickness of 3 to 40 μm, the alignment film may have a thickness of 30 to 250 nm, the electrode layer may have a thickness of 3 to 150 nm, and the heat-insulating electrode layer may have a thickness of 3 to 250 nm.

Additionally, the above-mentioned substrate may have a thickness of 10 to 240 μm.

Additionally, the above-mentioned description portion may be provided on both sides of the liquid crystal portion.

In addition, the invention may further include an adhesive layer disposed on the back surface of the substrate portion facing the heat-insulating electrode layer.

Additionally, the adhesive layer may have a thickness of 2 to 160 μm.

Additionally, the average reflectance measured every 10 nm in a wavelength range of 380 to 780 nm can be 1.5 to 6.5%, and the average reflectance measured every 50 nm in a wavelength range of 350 to 2100 nm can be 33 to 47%.

Additionally, the average reflectance measured every 10 nm in the wavelength range of 380 to 780 nm can be 1.5 to 6.5%.

In addition, the deviation of the average reflectance measured every 10 nm at a wavelength of 380 to 780 nm after applying a voltage of 60 V may be within ±5% compared to the average reflectance measured every 10 nm at a wavelength of 380 to 780 nm, and the deviation of the average reflectance measured every 50 nm at a wavelength of 350 to 2100 nm after applying a voltage of 60 V may be within ±5% compared to the average reflectance measured every 50 nm at a wavelength of 350 to 2100 nm.

In addition, the present invention provides a variable window including the above-described heat-insulating film.

The heat-insulating film of the present invention and the variable window including the same have a remarkably excellent heat-insulating function, and can change their physical properties depending on the application of power, while exhibiting excellent invisibility when power is applied and exhibiting excellent visibility when power is not applied.

Figure 1 is a cross-sectional view of a heat-insulating film according to one embodiment of the present invention.
FIG. 2 is a cross-sectional view of a variable window according to one embodiment of the present invention.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, in order to clearly describe the present invention, parts that are not related to the description are omitted, and the same reference numerals are added to the same or similar components throughout the specification.

The term 'deviation' used in the present invention is a term indicating 'the ratio of the value after voltage application to the initial value'. For example, if the initial value is 100 and the value after voltage application is 97, the deviation is -3%, and if the initial value is 100 and the value after voltage application is 102, the deviation can be said to be +2%.

According to one embodiment of the present invention, a heat-insulating film includes, as illustrated in FIG. 1, an electrode layer (11), a heat-insulating electrode layer (12), and a liquid crystal part (10) including a liquid crystal layer (13) interposed between the electrode layer (11) and the heat-insulating electrode layer (12) and having alignment films (14, 15) arranged on both sides, and a substrate part (20, 30) provided on one or both sides of the liquid crystal part (10).

First, before explaining each layer provided in the heat-insulating film (100) according to one embodiment of the present invention, the reason why the heat-insulating film (100) according to the present invention must satisfy all of the following conditions (1) to (3) will be explained.

If the average transmittance measured every 10㎚ in a wavelength of 380 to 780㎚ of the heat-insulating film is low, the desired visibility may not be achieved when power is not applied, and if the average transmittance measured every 10㎚ in a wavelength of 380 to 780㎚ of the heat-insulating film is high, the invisibility may not be achieved at the desired level when power is applied. In addition, if the average transmittance measured every 50㎚ in a wavelength of 350 to 2100㎚ of the heat-insulating film is low, the desired level of visibility may not be achieved when power is not applied, and if the average transmittance measured every 50㎚ in a wavelength of 350 to 2100㎚ of the heat-insulating film is high, the invisibility may not be achieved at the desired level when power is applied, and the heat-insulating performance may not be good. In addition, if the turbidity of the heat-insulating film is low, the invisibility may not be expressed at the intended level when power is supplied, and the heat-insulating performance may be reduced. If the turbidity of the heat-insulating film is high, the intended visibility may not be expressed when power is not supplied.

In addition, if the average transmittance measured at every 10 nm in a wavelength range of 380 to 780 nm when a voltage of 60 V is applied is low, or if the average transmittance measured at every 10 nm in a wavelength range of 380 to 780 nm when a voltage of 60 V is applied is low, visibility may not be good when power is not applied, and if the average transmittance measured at every 10 nm in a wavelength range of 380 to 780 nm when a voltage of 60 V is applied is high, or if the average transmittance measured at every 50 nm in a wavelength range of 350 to 2100 nm when a voltage of 60 V is applied is high, heat insulation performance may not be good, and visibility may deteriorate when power is applied. In addition, if the turbidity measured by applying 60 V of voltage is low, the heat insulation performance may be degraded and the visibility may be reduced when power is applied, and if the turbidity measured by applying 60 V of voltage is high, the visibility may be poor when power is not applied.

Accordingly, the heat-insulating film should have a predetermined ratio of average transmittance at a wavelength of 380 to 780 nm and average transmittance at a wavelength of 380 to 780 nm measured by applying a voltage of 60 V, and should have a predetermined value of average transmittance at a wavelength of 350 to 2100 nm and average transmittance at a wavelength of 350 to 2100 nm measured by applying a voltage of 60 V, and should have a predetermined ratio of turbidity and turbidity measured by applying a voltage of 60 V. Accordingly, the heat-insulating film (100) according to the present invention is designed to satisfy all of the following conditions (1) to (3).

As condition (1), A1:A2 may be 1:0.0032 to 0.26, preferably A1:A2 may be 1:0.0055 to 0.19, as condition (2), B1 may be 3 to 35 and B2 may be 0.3 to 8, preferably B1 may be 4 to 33 and B2 may be 0.5 to 6.5, and as condition (3), C1:C2 may be 1:5.5 to 200, preferably C1:C2 may be 1:6.6 to 99.6.

At this time, A1 represents the average transmittance (%) measured every 10 nm at a wavelength of 380 to 780 nm, B1 represents the average transmittance (%) measured every 50 nm at a wavelength of 350 to 2100 nm, C1 represents turbidity (%), A2 represents the average transmittance (%) measured every 10 nm at a wavelength of 380 to 780 nm by applying a voltage of 110 V, B2 represents the average transmittance (%) measured every 50 nm at a wavelength of 350 to 2100 nm by applying a voltage of 110 V, and C2 represents turbidity (%) measured by applying a voltage of 110 V.

If A1 : A2 in the above condition (1) is less than 1 : 0.0032, the invisibility may not be achieved at the intended level when power is supplied, and the visibility may be poor when power is not supplied. If A1 : A2 exceeds 1 : 0.26, the intended visibility may not be achieved when power is not supplied, the heat insulation performance may be poor, and the invisibility may deteriorate when power is supplied. In addition, if B1 is less than 3 or B2 is less than 0.3 in the above condition (2), the visibility may be poor when power is not supplied, and if B1 exceeds 35 or B2 exceeds 8, the heat insulation performance may be poor, and the invisibility may deteriorate when power is supplied. And, if in the above condition (3), C1:C2 is less than 1:5.5, the intended visibility may not be achieved when power is not supplied, the heat insulation performance may deteriorate, and the invisibility may deteriorate when power is supplied, and if C1:C2 exceeds 1:200, the invisibility may not be achieved at the intended level when power is supplied, the heat insulation performance may deteriorate, and the visibility may not be good when power is not supplied.

Below, each layer provided in the heat-insulating film (100) is described.

First, the electrode layer (11) will be described.

The above electrode layer (11) is arranged on one side of the liquid crystal layer (13) described later, and when power is applied, the applied power is supplied to the liquid crystal layer (13), thereby orienting the liquid crystal contained in the liquid crystal layer (13), thereby performing the function of changing the properties of the heat-insulating film depending on whether power is applied.

The electrode layer (11) may be used without limitation as long as it is a material capable of performing the functions described above in the art, and preferably may include at least one of a conductive polymer, a conductive metal, a conductive nanowire, or a metal oxide, more preferably may include a metal oxide, and more preferably, ITO (Indium Tin Oxide) may be more advantageous for achieving the purpose of the present invention.

In addition, the electrode layer (11) may have a thickness of 3 to 150 nm, and preferably a thickness of 4 to 130 nm. If the thickness of the electrode layer is less than 3 nm, the resistance may be high, which may reduce the reaction speed, and the desired level of invisibility may not be exhibited when power is applied, and if the thickness of the electrode layer exceeds 150 nm, the transmittance by wavelength may be reduced, and the visibility may be reduced when power is not applied.

And, the electrode layer (11) may have a surface resistance of 5 to 250Ω/□, and preferably, the surface resistance may be 8 to 230Ω/□. If the surface resistance of the electrode layer is less than 5Ω/□, the transmittance by wavelength may decrease, and the visibility may decrease when power is not applied, and if the surface resistance exceeds 250Ω/□, the resistance may be high, so the response speed may decrease, and the desired level of invisibility may not be exhibited when power is applied.

Next, the above-mentioned heat-insulating electrode layer (12) will be described.

The above-described heat-insulating electrode layer (12) is arranged on the other side of the liquid crystal layer (13) described later, together with the electrode layer (11) described above, and supplies the applied power to the liquid crystal layer (13) when power is applied, thereby performing the function of changing the physical properties of the heat-insulating film depending on whether power is applied by orienting the liquid crystal included in the liquid crystal layer (13), and at the same time performing the function of improving the heat-insulating performance of the heat-insulating film (100). That is, the above-described heat-insulating electrode layer (12) performs the function of an electrode that orients the liquid crystal and also exhibits heat-insulating performance.

The above-described heat-insulating electrode layer (11) may be formed of any material capable of performing the functions described above in the art without limitation, but preferably, at least one selected from the group consisting of a metal including at least one of gold, silver, copper, aluminum, platinum, titanium, iron, nickel, chromium, palladium, indium, tin, and zinc, an alloy including at least two of the above-described metals, and a metal oxide including at least one of the above-described metals may be used, and more preferably, at least one selected from the group consisting of a metal including at least one of gold, silver, copper, aluminum, nickel, chromium, indium, tin, and zinc, an alloy including at least two of the above-described metals, and a metal oxide including at least one of the above-described metals may be used.

Meanwhile, the heat-insulating electrode layer (11) may be implemented as a multilayered heat-insulating electrode layer (not shown) including at least two or more metal-derived layers, and preferably, the multilayered heat-insulating electrode layer may include 3 to 7 metal-derived layers, more preferably, 3 to 6 metal-derived layers, and even more preferably, 3 to 5 metal-derived layers. When the heat-insulating electrode layer (11) is implemented as a multilayered heat-insulating electrode layer (not shown) including at least two or more metal-derived layers, if the number of metal-derived layers of the multilayered heat-insulating electrode layer is less than 3 or more than 7, the effect of the present invention may not be expressed at the intended level.

The above-mentioned heat-insulating electrode layer (12) may have a thickness of 3 to 250 nm, and preferably, a thickness of 4 to 230 nm. If the thickness of the above-mentioned heat-insulating electrode layer is less than 3 nm, the heat-insulating performance may be reduced, the resistance may be high, which may reduce the reaction speed, and the desired level of invisibility may not be exhibited when power is applied. If the thickness of the above-mentioned heat-insulating electrode layer exceeds 250 nm, the transmittance by wavelength may be reduced, and the visibility may be reduced when power is not applied.

And, the heat-insulating electrode layer (12) may have a surface resistance of 3 to 70Ω/□, and preferably, the surface resistance may be 4 to 65Ω/□. If the surface resistance of the heat-insulating electrode layer is less than 3Ω/□, the transmittance by wavelength may decrease, and the visibility may decrease when power is not applied, and if the surface resistance exceeds 70Ω/□, the heat-insulating performance may decrease, the response speed may decrease due to high resistance, and the desired level of invisibility may not be exhibited when power is applied.

Next, the liquid crystal layer (13) interposed between the electrode layer (11) and the heat-insulating electrode layer (12) and having alignment films (14, 15) arranged on both sides will be described.

The liquid crystal layer (13) above performs the function of changing the properties of the heat-insulating film by changing the state to transparent, translucent, or opaque by a human power source. Specifically, when power is not applied to the liquid crystal layer (13), the liquid crystal is aligned in a direction (ㅣ) parallel to the thickness direction of the heat-insulating film, and when power is applied to the liquid crystal layer (13), the liquid crystal is randomly aligned and the properties can be changed.

Since the liquid crystal layer (13) described above can be used without limitation as long as it has a composition of a liquid crystal layer that can be commonly used in the art, the present invention does not specifically limit it.

In addition, the liquid crystal layer (13) may have a thickness of 3 to 40 μm, and preferably, a thickness of 6 to 35 μm. If the thickness of the liquid crystal layer is less than 3 μm, the desired level of invisibility may not be exhibited when power is applied, and the change in physical properties due to power application may be minimal. If the thickness exceeds 40 μm, the transmittance by wavelength may decrease, and visibility may decrease when power is not applied.

Meanwhile, the liquid crystal layer (13) includes alignment films (14, 15) arranged on both sides.

The above alignment film (14, 15) performs the function of aligning the liquid crystal molecules of the liquid crystal layer (13) in a predetermined direction. At this time, alignment means that when a system composed of molecules having an electric dipole moment is placed in an electric field, the direction of the dipole is identical to the direction of the electric field.

Since the above alignment film (14, 15) can be used without limitation as long as it is a component of an alignment film that can be commonly used in the art, the present invention does not specifically limit it.

In addition, the alignment film (14, 15) may have a thickness of 30 to 250 nm, and preferably, a thickness of 40 to 230 nm. If the thickness of the alignment film is less than 30 nm, the desired level of invisibility may not be exhibited when power is applied, and the change in physical properties due to power application may be minimal. If the thickness exceeds 250 nm, the transmittance by wavelength may decrease, and the visibility may decrease when power is not applied.

Next, the substrate portion (20, 30) provided on one or both sides of the liquid crystal portion (10) will be described.

The above-mentioned substrate (20, 30) is provided on one or both sides of the liquid crystal portion (10), and preferably, can be provided on both sides of the liquid crystal portion (10). Accordingly, it performs the function of a support layer for the electrode layer (11) and the heat-insulating electrode layer (12) described above, while also performing the function of protecting the heat-insulating film (100).

The above-mentioned substrate (20, 30) can be made of any material that is common in the art and can perform the function of supporting the electrode layer (11) and the heat-insulating electrode layer (12) described above while also protecting the heat-insulating film (100), and preferably, PET film can be used.

In addition, the substrate portion (20, 30) may have a thickness of 10 to 240 μm, and preferably, a thickness of 15 to 220 μm. If the thickness of the substrate portion is less than 10 μm, the substrate portion may be deformed or broken during the manufacturing process, and a thickness deviation of the substrate portion and/or each layer due to substrate portion tension unevenness may occur, resulting in poor appearance and optical characteristics (transmittance and haze). If the thickness of the substrate portion exceeds 240 μm, curling defects may occur, and a problem may occur in which the desired haze range cannot be exhibited.

Meanwhile, according to another embodiment of the present invention, as illustrated in FIG. 2, the heat-insulating film (100') may further include an adhesive layer (40) disposed on the back surface of the substrate (20) facing the heat-insulating electrode layer (12).

The above adhesive layer (40) has the function of adhering the heat-insulating film (100, 100') to the window (200), and any adhesive layer component that can be commonly used in the art can be used without limitation, and preferably, one selected from the group consisting of a polyester resin, a urethane resin, an acrylic resin, or a resin including derivatives thereof can be used.

In addition, the adhesive layer (40) may have a thickness of 2 to 160 μm, and preferably a thickness of 3 to 150 μm. If the thickness of the adhesive layer is less than 2 μm, the adhesive strength may be reduced, and if the thickness exceeds 160 μm, there may be problems such as increased raw material costs and a long curing time, which may result in reduced production speed and increased energy consumption due to the need for a large amount of heat, and visibility may be reduced when power is not applied due to differences in surface roughness and refractive index of the adhesive layer.

The heat-insulating film (100) according to the present invention may have an average transmittance of 60 to 90% measured every 10 nm at a wavelength of 380 to 780 nm to satisfy the above-described condition (1), and preferably, the average transmittance measured every 10 nm at a wavelength of 380 to 780 nm may be 65 to 88%. If the average transmittance measured every 10 nm at the wavelength of 380 to 780 nm is less than 60%, the desired visibility may not be achieved when power is not applied, and if the average transmittance measured every 10 nm at the wavelength of 380 to 780 nm exceeds 90%, the invisibility may not be achieved at the desired level when power is applied, and the heat-insulating performance may not be good.

In addition, the heat-insulating film (100) according to the present invention may have an average transmittance of 0.3 to 15%, preferably 0.5 to 12%, measured at every 10 nm at a wavelength of 380 to 780 nm by applying a voltage of 60 V to satisfy the above-described condition (1). If the average transmittance at a wavelength of 380 to 780 nm measured by applying a voltage of 60 V is less than 0.3%, visibility may be poor when power is not applied, and if the average transmittance at a wavelength of 380 to 780 nm measured by applying a voltage of 60 V exceeds 15%, heat-insulating performance may be poor, and invisibility may deteriorate when power is applied.

In addition, the heat-insulating film (100) according to the present invention may have a turbidity of 0.5 to 15% to satisfy the above-described condition (3), and preferably, the turbidity may be 1 to 13%. If the turbidity is less than 0.5%, the invisibility may not be expressed at the desired level when power is applied, and the heat-insulating performance may be degraded, and if the turbidity exceeds 15%, the desired visibility may not be expressed when power is not applied.

And, furthermore, the heat-insulating film (100) according to the present invention may have a turbidity of 85 to 99.7% measured by applying a voltage of 60 V to satisfy the above-described condition (3), preferably, a turbidity of 88 to 99.5% measured by applying a voltage of 60 V. If the turbidity measured by applying the voltage of 60 V is less than 85%, the heat-insulating performance may deteriorate and the visibility may deteriorate when power is applied, and if the turbidity measured by applying the voltage of 60 V exceeds 99.7%, the visibility may not be good when power is not applied.

The heat-insulating film (100) according to the present invention may have an average reflectance of 1.5 to 6.5% measured every 10 nm at a wavelength of 380 to 780 nm, preferably an average reflectance of 2 to 6% measured every 10 nm at a wavelength of 380 to 780 nm, an average reflectance of 33 to 47% measured every 50 nm at a wavelength of 350 to 2100 nm, and preferably an average reflectance of 35 to 45% measured every 50 nm at a wavelength of 350 to 2100 nm. If the average reflectivity measured every 10 nm in the wavelength range of 380 to 780 nm is less than 1.5%, or the average reflectivity measured every 50 nm in the wavelength range of 350 to 2100 nm is less than 33%, the heat insulating performance may deteriorate, and the invisibility may not be expressed at the intended level when power is applied. In addition, if the average reflectivity measured every 10 nm in the wavelength range of 380 to 780 nm exceeds 6.5%, or the average reflectivity measured every 50 nm in the wavelength range of 350 to 2100 nm exceeds 47%, the intended visibility may not be expressed when power is not applied.

Meanwhile, a heat-insulating film (100, 100') according to another embodiment of the present invention includes a liquid crystal part including an electrode layer, a heat-insulating electrode layer, and a liquid crystal layer interposed between the electrode layer and the heat-insulating electrode layer and having alignment films disposed on both sides, and a substrate part provided on one or both sides of the liquid crystal part, and has an average transmittance of 3 to 35% measured every 50 nm at a wavelength of 350 to 2100 nm, and an average reflectance of 33 to 47% measured every 50 nm at a wavelength of 350 to 2100 nm. Preferably, the average transmittance measured every 50 nm at a wavelength of 350 to 2100 nm may be 4 to 33%, and the average reflectance measured every 50 nm at a wavelength of 350 to 2100 nm may be 35 to 45%. If the average transmittance at a wavelength of 350 to 2100 nm is less than 3%, the intended visibility may not be achieved when power is not supplied. If the average transmittance at a wavelength of 350 to 2100 nm exceeds 35%, the intended level of invisibility may not be achieved when power is supplied, and the heat-insulating performance may not be good.

Meanwhile, the heat-insulating film (100, 100') according to one embodiment of the present invention may have a deviation of within ±5% in the average reflectance measured every 10 nm at a wavelength of 380 to 780 nm after applying a voltage of 60 V compared to the average reflectance measured every 10 nm at a wavelength of 380 to 780 nm, and preferably, the deviation of the average reflectance measured every 10 nm at a wavelength of 380 to 780 nm after applying a voltage of 60 V may be within ±4% in the average reflectance measured every 10 nm at a wavelength of 380 to 780 nm, and the deviation of the average reflectance measured every 50 nm at a wavelength of 350 to 2100 nm after applying a voltage of 60 V may be within ±5% in the average reflectance measured every 50 nm at a wavelength of 350 to 2100 nm, and preferably, the deviation of the average reflectance measured every 50 nm at a wavelength of 350 to 2100 nm after applying a voltage of 60 V may be within ±5% in the average reflectance measured every 10 nm at a wavelength of 350 to 2100 nm. The deviation of the average reflectance measured every 50 nm at a wavelength of 350 to 2100 nm after applying a voltage of 60 V can be within ±4% compared to the average reflectance measured every 50 nm. Accordingly, it can be more advantageous in terms of simultaneously expressing the effects of excellent heat-insulating properties, the ability to change properties depending on the power supply, and excellent visibility when power is supplied, and invisibility when power is not supplied.

Meanwhile, a heat-insulating film (100) according to one embodiment of the present invention can be manufactured through the manufacturing method described below, but is not limited thereto.

A heat-insulating film (100) according to the present invention can be manufactured through a manufacturing method including a step of forming a heat-insulating electrode layer (12) on a substrate (20) and forming an alignment film (15) on the heat-insulating electrode layer (12) to form a first laminate, a step of forming an electrode layer (11) on another substrate (30) and forming an alignment film (14) on the electrode layer (11) to form a second laminate, and a step of forming a liquid crystal layer (13) on the first laminate and laminating the second laminate on the liquid crystal layer (13).

At this time, the electrode layer (11) and the heat-insulating electrode layer (12) can be formed without limitation using any forming method that can be commonly used in the art, and preferably, can be formed through a deposition process.

In addition, the alignment film (14, 15) can be formed without limitation using any forming method that can be commonly used in the art, and preferably, can be formed through a method such as coating, but is not limited thereto.

And, the liquid crystal layer (13) can be formed without limitation using any forming method that can be commonly used in the art, and preferably can be formed through a method such as coating or filling, and more preferably can be formed through coating.

Meanwhile, a method for manufacturing a heat-insulating film according to another embodiment of the present invention may further include, after the step of laminating the second laminate, a step of forming an adhesive layer (40) on the back surface of the substrate portion (20) facing the heat-insulating electrode layer (12).

At this time, the adhesive layer (40) can be formed without limitation using any forming method that can be commonly used in the art, and preferably, it can be formed through a laminating process.

Meanwhile, the present invention provides a variable window (1000) including the above-described heat-insulating film (100, 100').

The above variable window (1000) is implemented by including the above-described heat-insulating film (100, 100') on at least one surface of the window (200). The above-described heat-insulating film may be fixed on at least one surface of the window (200) through the above-described adhesive layer (40), but is not limited thereto.

The heat-insulating film of the present invention has a remarkably excellent heat-insulating function, and can change its physical properties depending on the application of power, and can exhibit the effect of exhibiting excellent invisibility when power is applied and excellent visibility when power is not applied. Accordingly, when the heat-insulating film of the present invention is applied to a window, it is possible to implement a variable window. Therefore, the heat-insulating film according to the present invention and the variable window including the same can be applied in various technical fields, and in particular, when applied to an automobile, it can be placed on the glass of the automobile, that is, the windshield, the rear window, the side windows of the seat, the sunroof, etc.

The present invention will be described more specifically through the following examples, but the following examples do not limit the scope of the present invention, and should be interpreted as helping to understand the present invention.

<Example 1>

First, two PET substrates (XG7PH8, Toray Advanced Materials) each having a thickness of 125 μm were prepared as substrates. By applying 2 kW of power at a 200 kHz pulse to one of the substrates to secure a base vacuum of 2.5 Х 10 ^-5 torr, a 35 nm-thick zinc tin oxide (ZTO), a 15 nm-thick silver-palladium-copper alloy (Ag-Pd-Cu; APC), and a 35 nm-thick zinc tin oxide (ZTO) were sequentially deposited using DC sputtering under nitrogen gas conditions at a ratio of 5 wt% based on 250 sccm (standard cubic centimeter per minute) of argon gas to form a heat-insulating electrode layer including three metal-derived layers, thereby forming a first laminate. Then, by applying 2 kW of power with 200 kHz pulses on another substrate, a base vacuum of 2.5 Х 10 ^-5 torr was secured, and then, using DC sputtering under the condition of nitrogen gas at a ratio of 5 wt% based on 250 sccm (standard cubic centimeter per minute) of argon gas, ITO (Indium Tin Oxide) with a thickness of 50 nm was deposited to form an electrode layer, thereby forming a second laminate.

Then, for the conductive surfaces of the first and second laminates manufactured above, an alignment film coating liquid composed of a polyimide component was formed with a thickness of 175 nm using a microgravure coating method to prepare an alignment film substrate.

Thereafter, a liquid crystal dispersion composition including a liquid crystal compound having negative dielectric anisotropy, a mixture of a urethane oligomer and a thiol-based prepolymer, a nucleic acid diol diacrylate monomer, and an ultraviolet photoinitiator (a photoinitiator forming an absorption peak in a wavelength range of 380 nm) was coated between the first and second laminates using a gap roll method, and UV curing was performed to form a liquid crystal layer having a thickness of 20 μm, thereby manufacturing a heat-insulating film as shown in FIG. 1.

<Examples 2 to 3 and Comparative Examples 1 to 6>

A heat-insulating film was manufactured in the same manner as in Example 1, but the type and thickness of the heat-insulating metal layer material were changed to manufacture a heat-insulating film as shown in Table 1 and Table 2 below.

<Experimental Example 1>

For each heat-insulating film manufactured according to Examples 1 to 3 and Comparative Examples 1 to 6, each heat-insulating film was attached to ordinary glass with an average thickness of 3 mm, and the following physical properties were evaluated, which are shown in Tables 1 and 2.

1. Measurement of average transmittance and average reflectance by wavelength

For each of the heat-insulating films manufactured according to Examples 1 to 3 and Comparative Examples 1 to 6, the average transmittance and average reflectance at a wavelength of 380 to 2100 nm were measured using a spectrophotometer (UV-VIS-NIR Spectrophotometer, Perkin-Elmer, Lambda 950, U.S.A) in accordance with KS L 2016:2014, 6.3 Optical Performance Test. By measuring the transmittance and reflectance at every 10 nm wavelength between 380 and 780 nm, the average transmittance and average reflectance at a wavelength of 380 to 780 nm were measured, respectively. By measuring the transmittance and reflectance at every 50 nm wavelength between 350 and 2100 nm, the average transmittance and average reflectance at a wavelength of 350 to 2100 nm were measured, respectively. At this time, the transmittance and reflectance at a wavelength of 380 to 780 nm were measured based on the electrode layer side, and the transmittance and reflectance at a wavelength of 350 to 2100 nm were measured based on the heat-insulating electrode layer side.

2. Turbidity measurement

For each heat-insulating film manufactured according to Examples 1 to 3 and Comparative Examples 1 to 6, the opacity due to diffusion in addition to reflection or absorption by transmitting light through the film was measured. (BYK, haze-gard plus)

3. Measurement of average transmittance and average reflectance by wavelength (power applied)

For each of the heat-insulating films manufactured according to Examples 1 to 3 and Comparative Examples 1 to 6, the average transmittance and reflectance by wavelength were measured using the same method as in “1”, but a voltage of 60 V was applied to measure the average transmittance and reflectance by wavelength.

4. Turbidity measurement (power on)

For each of the heat-insulating films manufactured according to Examples 1 to 3 and Comparative Examples 1 to 6, turbidity was measured using the same method as “2”, but turbidity was measured by applying a voltage of 60 V.

5. Evaluation of thermal insulation characteristics

For each heat-insulating film manufactured according to Examples 1 to 3 and Comparative Examples 1 to 6, the performance was measured according to the KS L 9107 Solar Heat Gain Coefficient (SHGC) measurement method for window glass films, and the values were presented.

6. Visibility and Invisibility Assessment

For each heat-insulating film manufactured according to Examples 1 to 3 and Comparative Examples 1 to 6, 30 experts with more than 15 years of industry experience visually evaluated the visibility and invisibility before and after application of a voltage of 60 V using the 7-point method.

* Visibility rating before voltage application: 1 - very bad, 2 - bad, 3 - somewhat bad, 4 - average, 5 - somewhat good, 6 - good, 7 - very good

* Invisibility evaluation after voltage application: 1-very bad, 2-bad, 3-slightly bad, 4-average, 5-slightly good, 6-good, 7-very good

division Example
1 Example
2 Example
3 Comparative example
1 Heat
Electrode layer lamination
structure Type/Thickness (nm) ZTO/35 ZTO/95 ZTO/
1.5 - Type/Thickness (nm) APC/15 APC/40 APC/
1 APC/
2.5 Type/Thickness (nm) ZTO/35 ZTO/95 ZTO/1.5 - Total thickness (nm) 85 230 4 2.5 Average Transmittance (%) Wavelength 380~780㎚, "A1" 77.4 65.5 87.8 94.8 Wavelength 380~780㎚(voltage applied), "A2" 5.6 0.53 11.5 15.7 Condition (1), A1:A2 0.072 0.0081 0.131 0.166 Wavelength 350~2100㎚,"B1" 17.6 4.2 32.9 30.6 Wavelength 350~2100㎚ (voltage applied), "B2" 3.1 0.53 6.5 5.9 Turbidity (%) "C1" 6.2 12.7 1.1 0.25 "C2" (voltage applied) 94.5 98.9 88.5 81 Condition (3), C1:C2 14.54 7.79 80.45 324 Average Reflectance (%) Wavelength 380~780㎚ 3.96 5.5 2.1 1.5 Wavelength 380~780㎚ (voltage applied) 4 5.4 2.1 1.5 Wavelength 380~780㎚ deviation (%) +1 -1.8 0 0 Wavelength 350~2100㎚ 39.7 44.5 35.6 34.5 Wavelength 350~2100㎚ (voltage applied) 40 44.3 35.7 34.3 Wavelength 350~2100㎚ deviation (%) +0.76 -0.45 +0.28 -0.58 Solar Heat Gain Rate (SHGC) 0.1 0.1 0.2 0.2 Visibility (/7 points, voltage not applied) 6.6 6.6 6.8 6.8 Invisibility (/7 points, voltage applied) 6.8 6.8 6.7 5.8

division Comparative example
2 Comparative example
3 Comparative example
4 Comparative example
5 Comparative example
6 Heat
Electrode layer lamination
structure Type/Thickness (nm) ZTO/100 ZTO/2 ZTO/
115 ZTO/
112.5 - Type/Thickness (nm) APC/70 APC/1 APC/30 APC/29 APC/
2 Type/Thickness (nm) ZTO/100 ZTO/2 ZTO/115 ZTO/
112.5 - Total thickness (nm) 270 5 260 254 2 Average Transmittance (%) Wavelength 380~780㎚, "A1" 66.3 85.2 55.2 60.1 91.7 Wavelength 380~780㎚(voltage applied), "A2" 0.55 9 0.1 0.2 24.4 Condition (1), A1:A2 0.0083 0.11 0.0018 0.0033 0.266 Wavelength 350~2100㎚,"B1" 2.6 37.5 4.8 4.7 27.8 Wavelength 350~2100㎚ (voltage applied), "B2" 0.2 8.2 1 1 4.7 Turbidity (%) "C1" 9.2 2.8 18 18.8 0.3 "C2" (voltage applied) 93.9 90.8 99.7 99.7 75.4 Condition (3), C1:C2 10.21 32.43 5.53 5.3 251.3 Average Reflectance (%) Wavelength 380~780㎚ 8 1.8 7.3 1.3 1.2 Wavelength 380~780㎚ (voltage applied) 7.5 1.8 7.6 1.3 1.2 Wavelength 380~780㎚ deviation (%) -6.3 0 +4.1 0 0 Wavelength 350~2100㎚ 48.4 32.3 45.6 32.6 33.8 Wavelength 350~2100㎚ (voltage applied) 47.8 32.4 45.6 32.5 33.9 Wavelength 350~2100㎚ deviation (%) -1.24 +0.31 0 -0.31 +0.3 Solar Heat Gain Rate (SHGC) 0.1 0.7 0.2 0.2 0.2 Visibility (/7 points, voltage not applied) 5.5 6.7 5.7 5.7 6.8 Invisibility (/7 points, voltage applied) 6.7 6.7 6.8 6.8 5.4

As can be seen from Table 1 and Table 2 above, Examples 1 to 3, which satisfy all of the types and thicknesses of the heat-insulating metal layer materials according to the present invention, are significantly superior in heat-insulating properties compared to Comparative Examples 1 to 6, which do not satisfy even one of these, and can simultaneously achieve the effects of exhibiting excellent visibility when power is not applied and excellent invisibility when power is applied, while allowing properties to change depending on the application of power.

<Comparative Example 7>

A heat-insulating film was manufactured in the same manner as in Example 1, but the heat-insulating electrode layer including three metal-derived layers was changed to ITO (Indium Tin Oxide) having a thickness of 50 nm, which is the same material as the electrode layer.

<Experimental Example 2>

For each heat-insulating film manufactured according to Example 1 and Comparative Example 7, the performance was measured according to the KS L 9107 Solar Heat Gain Coefficient (SHGC) measurement method for window glass films, and the values were presented.

division Example
1 Comparative example
7 Thermal electrode layer Type of material ZTO / APC / ZTO ITO Solar Heat Gain Rate (SHGC) 0.1 0.8

As can be seen from Table 3 above, it can be confirmed that Example 1 including a heat-insulating electrode layer according to the present invention has significantly superior heat-insulating characteristics compared to Comparative Example 7 including an electrode layer other than a heat-insulating electrode layer.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiment presented in this specification, and those skilled in the art who understand the spirit of the present invention will be able to easily propose other embodiments by adding, changing, deleting, or adding components within the scope of the same spirit, but this will also be considered to fall within the spirit of the present invention.

10: Liquid crystal part
11: Electrode layer
12: Heat-insulating electrode layer
13: Liquid crystal layer
14, 15: Alignment film
20, 30: Ministry of Finance
40: Adhesive layer
100: Heat-insulating film
200: Windows
1000: Variable window

Claims (16)

A liquid crystal part including an electrode layer, a heat-insulating electrode layer, and a liquid crystal layer interposed between the electrode layer and the heat-insulating electrode layer and having alignment films disposed on both sides; and
Including a substrate provided on one or both sides of the liquid crystal portion;
All of the following conditions (1) to (3) are satisfied,
Turbidity is 0.5 to 15%,
A heat-insulating film having an average transmittance of 0.3 to 15% and a turbidity of 85 to 99.5%, measured at 10 nm intervals over a wavelength of 380 to 780 nm, when measured by applying a voltage of 60 V:
(1) A1: A2 is 1: 0.0032 ~ 0.26
(2) B1 is 3 to 35 and B2 is 0.3 to 8
(3) C1: C2 is 1:5.5 ~ 200
At this time, A1 represents the average transmittance (%) measured every 10 nm at a wavelength of 380 to 780 nm, B1 represents the average transmittance (%) measured every 50 nm at a wavelength of 350 to 2100 nm, C1 represents turbidity (%), A2 represents the average transmittance (%) measured every 10 nm at a wavelength of 380 to 780 nm by applying a voltage of 60 V, B2 represents the average transmittance (%) measured every 50 nm at a wavelength of 350 to 2100 nm by applying a voltage of 60 V, and C2 represents turbidity (%) measured by applying a voltage of 60 V. A liquid crystal part including an electrode layer, a heat-insulating electrode layer, and a liquid crystal layer interposed between the electrode layer and the heat-insulating electrode layer; and
Including a substrate provided on one or both sides of the liquid crystal portion;
The average transmittance measured every 50 nm in the wavelength range of 350 to 2100 nm is 3 to 35%.
The average reflectance measured every 50 nm in the wavelength range of 350 to 2100 nm is 33 to 47%,
The turbidity is 0.5 to 15%,
A heat-insulating film having an average transmittance of 0.3 to 15% and a turbidity of 85 to 99.5%, measured at 10 nm intervals over a wavelength of 380 to 780 nm, when measured by applying a voltage of 60 V. In the first paragraph,
A heat-insulating film satisfying all of the following conditions (1) to (3):
(1) A1: A2 is 1: 0.0055 ~ 0.19
(2) B1 is 4 to 33 and B2 is 0.5 to 6.5
(3) C1:C2 is 1:6.6 ~ 99.6. In claim 1 or 2,
A heat-insulating film with an average transmittance of 60 to 90% measured every 10 nm at a wavelength of 380 to 780 nm. delete In claim 1 or 2,
The above-mentioned heat-insulating electrode layer is a heat-insulating film including at least two metal-derived layers. In claim 1 or 2,
The above liquid crystal layer has a thickness of 3 to 40 μm,
The above electrode layer has a thickness of 3 to 150 nm,
The above-mentioned heat-insulating electrode layer is a heat-insulating film having a thickness of 3 to 250 nm. In claim 1 or 2,
The above-mentioned description is a heat-insulating film having a thickness of 10 to 240㎛. In claim 1 or 2,
The above-mentioned part is a heat-insulating film provided on both sides of the liquid crystal part. In claim 1 or 2,
A heat-insulating film further comprising an adhesive layer disposed on the back surface of a substrate portion facing the heat-insulating electrode layer. In Article 10,
The above adhesive layer is a heat-insulating film having a thickness of 2 to 160 μm. In the first paragraph,
The average reflectance measured every 10 nm in the wavelength range of 380 to 780 nm is 1.5 to 6.5%,
A heat-insulating film with an average reflectance of 33 to 47% measured every 50 nm over a wavelength of 350 to 2100 nm. In the second paragraph,
A heat-insulating film with an average reflectance of 1.5 to 6.5% measured every 10 nm over a wavelength of 380 to 780 nm. In claim 1 or 2,
The deviation of the average reflectance measured every 10㎚ at a wavelength of 380 to 780㎚ after applying a voltage of 60V is within ±5%, compared to the average reflectance measured every 10㎚ at a wavelength of 380 to 780㎚.
A heat-insulating film having a deviation of within ±5% between the average reflectance measured every 50 nm at a wavelength of 350 to 2100 nm and the average reflectance measured every 50 nm at a wavelength of 350 to 2100 nm after applying a voltage of 60 V. A variable window comprising a heat-insulating film according to any one of claims 1 to 3, 12 and 13. In the first paragraph,
The above-mentioned alignment film is a heat-insulating film having a thickness of 30 to 250 nm.

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