WO2019093566A1

WO2019093566A1 - Optical laminate comprising organic/inorganic hybrid thermochromic layer having excellent adhesion using solution process and method for producing same

Info

Publication number: WO2019093566A1
Application number: PCT/KR2017/013275
Authority: WO
Inventors: 김대업; 김광석; 정하나; 윤지원; 손은원
Original assignee: 한국생산기술연구원
Priority date: 2017-11-08
Filing date: 2017-11-21
Publication date: 2019-05-16

Abstract

The present invention relates to an optical laminate comprising: a substrate; and a thermochromic layer formed on the substrate and including vanadium oxide particles, wherein the thermochromic layer is controlled to have a specific pore area ratio, and including an organic material that provides adhesion with the substrate and an inorganic material that realizes a thermochromic effect, wherein the content of the organic material and the inorganic material may be controlled to realize the adhesion and the thermochromic effect of the thermochromic layer, simultaneously.

Description

An optical laminate comprising an organic / inorganic hybrid thermochromic layer having excellent adhesion using a solution process and a method for producing the same

The present invention relates to an optical laminate including a thermochromic layer and a method of manufacturing the same.

As the disadvantages of conventional coal, petroleum or nuclear energy sources are highlighted, there is a growing need to develop new alternative energy sources. But it is equally important to control energy consumption. In fact, more than 60% of household energy consumption is used for heating and cooling. In particular, 24% of the energy consumed by windows in general houses and buildings is consumed. Therefore, in order to reduce the energy consumed through the windows, various efforts have been made from the method of adjusting the window size to the method of installing the high insulating windowpane.

For example, thermochromic glass has been studied in which a thermochromic layer having a thermochromism is coated on a glass to control the inflow of energy through control of infrared transmittance.

Thermal discoloration is a phenomenon in which the color of an oxide or a sulphide of a certain transition metal reversibly changes at a transition temperature (or a critical temperature). When such a heat-discoloring material is coated on a glass, visible light appears at a specific temperature or higher It is possible to produce a thermally discolored glass in which near infrared rays and infrared rays are blocked and the room temperature is not increased. By using this characteristic, it is possible to shield the near-infrared light at the high temperature of the summer iron to suppress the temperature rise in the room, and to bring out the light energy from the outside at the low temperature in winter. The use of such heat discoloration glass in the windows of a building can provide a great energy saving effect.

As a material exhibiting a thermochromic effect, oxides or sulfides of various transition metals are available. Among them, studies on the use of vanadium dioxide (VO ₂ ) having a transition temperature of 68 are mainly performed.

Korean Patent No. 10-1286170 discloses a technique of coating vanadium dioxide on a glass plate using a sputtering deposition method and Japanese Patent Application Laid-Open No. 2007-22838 discloses a technique of coating vanadium dioxide on a glass plate using a CVD process . However, conventional methods of coating vanadium dioxide on a glass plate, such as a sputtering deposition method or a CVD process, require a subsequent heat treatment step, requiring a long process time and making it difficult to produce a large-area product. In addition, there is a great limitation in the selection of the material of the substrate on which the vanadium dioxide is coated due to the high temperature heat treatment process.

Japanese Patent Application Laid-Open No. 2016-188939 discloses a method of dispersing vanadium dioxide-containing fine particles in a binder resin and applying the dispersion onto a polymer substrate to form an optical functional layer. However, since the particles are difficult to uniformly disperse in the polymer resin and the sintering process is not performed, the crystallinity is decreased, the light blocking effect is not sufficient, and the light transmission characteristics are hindered by the polymer resin.

An object of the present invention is to provide an optical laminate which can be manufactured in a large area by a simple manufacturing process and has physical properties such as controlled visible light and infrared ray transmission characteristics.

In order to solve the above problems, the present invention provides a substrate comprising: a substrate; And a thermochromic layer formed on the substrate, wherein the adhesive strength between the thermochromic layer and the substrate is 50 N / m or more, the thermochromic layer contains vanadium oxide and an organic material, Lt; RTI ID = 0.0 > 1: < / RTI >

[Formula 1]

W _i represents the initial weight of the sample, and W _f represents the weight after heat treatment of the sample at 700 ° C. for 2 hours.

The thermochromic layer may satisfy the following general formula 2:

[Formula 2]

5? S (%)? 40

Where S represents the area ratio of the voids measured by analyzing the image of the upper surface of the sample taken by the image analyzer.

Further, the thermochromic layer may satisfy the following general formula (3).

[Formula 3]

C _opposite <C _contact

In the general formula 1, C _opposite represents the content of carbon atoms measured on the surface, and C _contact represents the content of carbon atoms measured on the contact surface.

According to the present invention, it is possible to produce a large-sized optical laminate by a simple manufacturing process, and there is no limitation on the material of the substrate on which the thermochromic layer is formed, excellent adhesion between the thermochromic layer and the substrate, An optical laminate having infrared ray transmission characteristics can be provided.

FIG. 1 is a graph showing a dispersion degree according to the content of a polymeric dispersant according to an embodiment of the present invention.

FIG. 2 is a graph showing the degree of dispersion according to the molecular weight of a polymeric dispersant according to an embodiment of the present invention.

3 is an electron microscope image of an optical laminate manufactured according to an embodiment of the present invention.

4 is an electron microscope image of an optical laminate manufactured according to another embodiment of the present invention.

5 is an electron microscope image of an optical laminate manufactured according to another embodiment of the present invention.

6 is an electron microscope image of an optical laminate manufactured according to another embodiment of the present invention.

FIG. 7 is an electron microscope image obtained by measuring a void area ratio of an optical laminate manufactured according to an embodiment of the present invention.

FIG. 8 is an electron microscope image obtained by measuring a void area ratio of an optical laminate manufactured according to a comparative example of the present invention. FIG.

9 is a graph showing the element content along the depth direction of the optical laminate manufactured according to an embodiment of the present invention.

10 is a graph showing an element content along the depth direction of an optical laminate manufactured according to a comparative example of the present invention.

The present invention relates to a substrate; And a thermochromic layer formed on the substrate, wherein the adhesive strength between the thermochromic layer and the substrate is 50 N / m or more, the thermochromic layer comprises vanadium oxide and an organic material, and satisfies the following general formula To the optical laminate.

[Formula 1]

In the general formula 1, W _i represents the initial weight of the sample, and W _f represents the weight after heat treatment of the sample at 700 ° C. for 2 hours. Specifically, the sample may mean an optical laminate or a thermochromic layer. For example, a material which does not cause weight reduction even when the substrate has a temperature of 700 占 폚, for example, a glass substrate, may include both the substrate and the thermochromic layer formed on the substrate. On the other hand, in the case where a material in which weight reduction occurs even at 700 ° C in the upper or lower part of the thermochromic layer, for example, a polymer material is laminated, the sample may mean all or a part of the thermochromic layer.

The weight loss (W _loss ) of the general formula (2) may mean the content of vanadium oxide particles in the thermochromic layer. The heat-discoloring layer of the present invention includes a vanadium oxide particle, which is an inorganic substance, and a polymer dispersant and / or a binder, which are organic substances. When heat treatment is performed at a temperature of 700 ° C or higher, most of the organic material is decomposed and disappears, Only. The thermochromic layer of the present invention includes an organic material that provides an adhesive force with a substrate and an inorganic material that exhibits a thermal discoloring effect, and the content of the organic material and the inorganic material is controlled, Can be implemented.

The content of the vanadium oxide particles is, for example, not less than 70%, not less than 75%, not less than 80%, not less than 85%, not less than 90%, or not less than 95% 100% or less, 99.9% or less, 99% or less, or 98% or less. Unlike the conventional thermochromic thin film layer prepared by applying a solution in which vanadium oxide is dispersed in a polymer resin and then curing the polymer, the present invention includes an organic substance and vanadium oxide in an amount required for producing a thin film in a solution, Since vanadium oxide is sintered and most organic substances are removed, the content of vanadium oxide contained in the thermochromic thin film layer can be greatly increased.

The adhesive strength between the heat-colorable layer and the substrate is 50 N / m or more, for example, 60 N / m or more, 70 N / m or more, 100 N / m or more, 120 N / m or 150 N / . The upper limit value of the adhesive strength is not particularly limited, but is, for example, 250 N / m or less, or 300 N / m or less. As used herein, the term " adhesive strength " means that the blade is calculated by measuring the resistance value generated when the thermochromic layer and the substrate are separated from each other, and the specific conditions necessary for the measurement can be found in Experimental Examples.

The thermochromic layer may satisfy the following general formula (2).

[Formula 2]

5? S (%)? 40

In the general formula (2), S represents the area ratio of the voids measured by analyzing an image of the upper surface of the sample taken by the image analyzer. Here, the upper surface means the surface of the substrate described above.

When the S value is controlled within the above range, the visible light transmittance and the infrared transmittance can be controlled, and the optical characteristics, particularly visible light transmittance, can be controlled even in a film having a thickness of 40 nm to 200 nm or more.

Since the present invention is manufactured by applying a solution composition containing vanadium oxide on a substrate, sintering the vanadium dioxide through light sintering or thermal sintering, and removing most of the organic substances present in the solution composition, Can be controlled. When a thermochromic thin film layer is produced by using a conventional vapor phase method such as sputtering or CVD, a desired effect can not be obtained by controlling the S value.

Specifically, the S value can be controlled in the solution through the content of the dispersant and the binder, the average diameter of the particles, the thickness of the thin film, and the specific conditions of the photolithography. When the S value is less than 5%, for example, less than 10%, less than 15%, less than 20%, or less than 25%, it is difficult to obtain the visible light transmittance. It is difficult to control the infrared ray blocking rate. The S value can be measured by a known method using an image photographing apparatus such as an electron microscope (SEM) and an image analyzing apparatus (S / W) for analyzing it. For example, the image analyzing apparatus can use software such as Image J, which can calculate the area of the gap by classifying the contrast ratio of the photographed image by using an image photographing apparatus such as an FE-SEM, Apparatus and software are known to those skilled in the art.

The thermochromic layer also satisfies the following general formula (3).

[Formula 3]

C _opposite <C _contact

In the heat-coloring layer according to the present invention, when the surface contacting the substrate is defined as a contact surface with respect to the cross-section of the thermochromic layer, and the surface opposite thereto is defined as the surface, the content of carbon atoms increases from the surface to the contact surface, The surface of the light-receiving surface has a low organic matter content and can have a sufficient heat discoloring effect. Specifically, the content of carbon in each surface can be controlled through the content of the dispersant and the binder in the solution, the average diameter of the particles, the thickness of the thin film, and the conditions of the sintering, for example, specific conditions of the photolithography. Further, the contact surface contains an organic substance within a range necessary for providing an adhesive force with the base material, and is excellent in adhesion to a substrate. When the adhesive strength is 50 N / m or less, peeling may occur at the interface during long-term use, and durability may be deteriorated.

Since the present invention is applied by applying a solution composition containing vanadium oxide on a substrate, sintering the vanadium oxide through a sintering process, and removing most of the organic substances present in the solution composition, the content of carbon atoms The desired adhesive strength can be obtained. In the case of producing a heat-discoloring layer using a conventional vapor-phase method such as sputtering or CVD, or in the case of a conventional heat-discoloring layer prepared by curing a polymer after application of a vanadium oxide dispersed solution, the content of carbon atoms in each surface is controlled The desired effect can not be obtained.

The substrate is not particularly limited as long as it can support the thermochromic layer. However, in consideration of the application such as a smart window, the average transmittance of the visible light region is preferably 80% or more, for example, 95% or more.

The kind of the substrate may be selected from glass, quartz or a polymer film. Particularly, the kind of the polymer film is not particularly limited, but a polyolefin film (for example, cycloolefin, polyethylene, polypropylene and the like), a polyester film (for example, polyethylene terephthalate, polyethylene naphthalate), polyvinyl chloride, Based film (for example, triacetyl cellulose) can be used. The polymer film may, for example, be stretched in more than one axis and have an export rate of less than 3% when exposed at 120 DEG C for 1 hour. When a stretched polymer film is used, excellent mechanical strength can be obtained and shrinkage can be prevented at a high temperature. The polymer film satisfying these conditions can be arbitrarily selected from among known materials.

The optical laminate preferably has a maximum transmittance ( _Pmax ) of 40% or more, specifically 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, not less than 70%, the minimum value _(min OP) of the transmission rate from 2000 to 3000nm at any temperature above the critical temperature may be up to 50% or less, particularly 45% or less, 40% or 35%. If P _max value of not less than 40%, and the visible light transmittance can be increased to ensure a clear field of view, when OP _min value is equal to or less than 50% it is excellent in UV shielding effect.

In the optical laminate, for example, the laminate may satisfy the condition of the following general formula (4).

[Formula 4]

? IR = (BP _min - OP _min )? 20

In the formula (4), BP _min represents the minimum value of the transmittance at 2000 to 3000 nm at any temperature below the critical temperature, and OP _min represents the minimum value of the transmittance at 2000 to 3000 nm at any temperature above the critical temperature. The temperature below the critical temperature may be, for example, 20 to 30 占 폚, specifically 25 占 폚, and the temperature above the critical temperature may be, for example, 60 to 90 占 폚, specifically 80 占 폚. When the ΔIR value (%) is 20 or more, specifically 30 or more, 40 or more or 45 or more, the effect on ultraviolet blocking / transmission is excellent.

The vanadium oxide particles contained in the heat-coloring layer may include rutile vanadium dioxide having an average diameter of 1 to 500 nm, or 20 to 300 nm. When the average diameter of the vanadium oxide particles is within the above range, it is possible to provide a uniform thin film and control desired optical characteristics such as visible light transmittance.

The thickness of the thermochromic layer is not particularly limited, but may be 0.1 to 5 탆, specifically 400 to 1000 nm, or 600 to 900 nm.

The optical laminate may further include a protective layer for protecting the thermochromic layer. The protective layer is not particularly limited, but a transparent polymer film can be used. The protective layer may have a function of shielding at least a part of the light wavelength range of 700 to 1000 nm in addition to the function of protecting the thermochromic layer. For details of the near-infrared light shielding layer applicable to the present invention, reference may be made, for example, to Japanese Patent Laid-Open Publication No. 2012-131130.

The present invention also relates to a method for producing an optical laminate using a solution containing vanadium oxide. A method for producing an optical laminate includes: applying a solution containing vanadium oxide on a substrate to form a coating layer; Removing solvent from the application layer; And sintering the vanadium oxide contained in the coating layer.

Wherein the solution composition containing vanadium oxide is at least one selected from the group consisting of vanadium oxide particles; menstruum; Polymer dispersant; And a binder, and the polymer dispersant has a molecular weight of 10,000 to 360,000 and a viscosity of 1 to 100 cP, specifically 5 to 40 cP.

The molecular weight of the polymeric dispersant usable in the present invention is 10,000 to 360,000, for example, 11,000 to 200,000, 12,000 to 100,000, or 15,000 to 70,000. When the molecular weight is within the above range, excellent dispersibility and viscosity necessary for applying the solution composition to the substrate can be secured.

The viscosity of the solution composition is from 1 to 100, for example from 1 to 40, from 5 to 30, from 10 to 25, or from 15 to 20. In addition to the molecular weight of the polymer dispersant, the viscosity can also be adjusted to the above range to satisfy the dispersibility of the particles and the conditions of the application process.

In the solution composition, the content of the polymer dispersant is, for example, 1 to 10% by weight, specifically 2 to 8% by weight and 3 to 7% by weight based on the total weight of the solution composition. It is necessary to control the content of the dispersing agent within the above range in order to control the visible light transmittance of the optical laminate and the crystallization of vanadium oxide.

Examples of the polymer dispersant include amine-based polymer dispersants such as polyethyleneimine and polyvinylpyrrolidone; A hydrocarbon-based polymeric dispersant having a carboxylic acid group in a molecule such as polyacrylic acid, carboxymethylcellulose or the like; And a polymer dispersant having a polar group such as polyvinyl alcohol, styrene-maleic acid copolymer, olefin-maleic acid copolymer, or copolymer having a polyethyleneimine moiety and a polyethylene oxide moiety in one molecule .

In one embodiment, the polymer dispersant may be a water-soluble polymer, specifically an amine-based polymer, particularly polyvinylpyrrolidone (PVP). When PVP is used, an aqueous solvent can be used. Therefore, environmental pollution can be minimized even when a large-sized optical laminate is manufactured because it is environment-friendly.

In the solution composition, the kind of the binder is not particularly limited, and examples thereof include a cellulose resin, a polyvinyl chloride resin, a polyvinyl alcohol resin, a polyvinyl pyrrolidone resin, an acrylic resin, a vinyl acetate- An ester resin, an ester copolymer resin, a butyral resin, an alkyd resin, an epoxy resin, a phenol resin, a rosin ester resin, a polyester resin and a silicone resin.

The content of the binder is, for example, 0.1 to 3% by weight, specifically 0.2 to 2% by weight and 0.5 to 1.5% by weight based on the total weight of the solution composition. If the content of the binder is more than 3% by weight, the binder may not be completely dissolved in the solvent, and the binder may agglomerate with time. If the content is less than 0.1% by weight, the adhesive strength to the substrate may be lowered.

Examples of the solvent include, but are not limited to, water, hydrocarbon solvents, chlorinated hydrocarbon solvents, cyclic ether solvents, ketone solvents, alcohols, polyhydric alcohol solvents, acetate solvents, polyhydric alcohols Of ether-based solvents or terpene-based solvents. The kind of the solvent can be selected according to the polymer binder and the dispersing agent to be used, but it is preferable to use a mixture of water and alcohol in consideration of environmental factors, dispersion characteristics and drying time. Concretely, in consideration of wettability, it is preferable to use alcohol. The alcohol is not particularly limited, but an alcohol having a straight chain alkyl group having 2 to 6 carbon atoms such as ethanol, propanol, or butanol can be used. Considering the drying time, it is preferable to use ethanol having a low boiling point.

In this case, the weight ratio of water and alcohol may be used in a ratio of, for example, 1: 0.5 to 1.5, specifically 1: 0.7 to 1.3, and 1: 0.8 to 1.2. When the weight ratio of water and alcohol is controlled within the above range, the binder and the dispersant can be sufficiently dissolved and an appropriate viscosity can be maintained.

The vanadium oxide particles may specifically include rutile vanadium dioxide (VO ₂ ) particles. The content of the vanadium dioxide particles is, for example, 1 to 50% by weight, for example, 5 to 40% by weight, 10 to 35% by weight and 15 to 30% by weight based on the total weight of the solution composition. Further, the average diameter of the vanadium dioxide particles may be 1 to 1000 nm, for example, 10 to 500 nm. When the vanadium dioxide particle content and the average diameter are controlled within the above range, excellent thin film formation, uniform dispersion and desired functionality can be obtained .

The solution composition can be prepared by mixing vanadium dioxide particles, a polymer dispersant, and a binder in a solvent and uniformly stirring. More particularly, the method comprises mixing a polymeric dispersant with a first solvent to produce a polymeric dispersant solution; Mixing the binder with a second solvent to prepare a binder solution; And mixing the polymer dispersant solution and the binder solution to vanadium dioxide particles to prepare an ink solution, optionally and optionally further mixing the dopant.

Ultrasonic waves can be applied to the solution to uniformly disperse the solution prepared in each step. For example, the manufacturing method includes: applying ultrasound to a polymer dispersant solution; Applying ultrasound to the binder solution; And applying ultrasonic waves to the ink solution. Conditions for applying ultrasonic waves are not particularly limited, but they can be applied for 30 minutes to 2 hours at each step.

In the above step, the first solvent and the second solvent are not limited as long as they are capable of dissolving the dispersant and the binder, respectively. For example, water may be used as the first solvent and ethanol may be used as the second solvent.

In the method for producing the optical laminate according to the present invention, the step of forming the coating layer is preferably performed by spin coating or spray coating. In embodiments, the spin coating can be repeated at least twice at a predetermined rotational speed and for a period of time. For example, the spin coating may include a first step of coating at a first rotational speed; A second step of coating at a second rotational speed; And a third rotational speed, wherein the second rotational speed may be faster than the first and third rotational speeds. More specifically, the first and third rotational speeds are 300 to 700 rpm, and the second rotational speed is 800 to 4000 rpm. The time for each step is 5 seconds to 50 seconds.

The step of sintering the vanadium oxide can be performed by thermal sintering or photo-sintering, but photo-sintering is preferable in consideration of advantages in the manufacturing process and adhesive strength. The heat sintering can be conducted at a temperature of 300 to 700 ° C for 30 minutes to 5 hours, but is not limited thereto.

Light sintering can control the desired properties by controlling the type of light, the applied voltage, the pulse width, the number of pulses, the pulse interval and the sintering atmosphere. In one embodiment, the light may use white light applied from a xenon lamp, the voltage is from 1000 to 3000 V, the number of pulses is from 1 to 500, the pulse interval is from 0.1 to 10 seconds, the pulse width is from 0.1 to 10 ms, Or under an inert atmosphere such as nitrogen or argon.

As the applied voltage increases, the polymer dispersant and / or binder decompose to expose the surface of the metal oxide. As the number of pulses increases, the interval between the metal oxide particles becomes narrower to form a cluster. As the number of pulses increases, the amount of polymer remaining on the surface decreases, but it is lower than the voltage.

On the other hand, as the photo-sintering voltage increases, the adhesion strength between the thin film and the substrate increases. The number of pulses is also related to the bonding strength. However, at a low voltage, for example, 1,400 V, the bonding strength increases as the number of pulses increases. At 2,000 V, the bonding strength decreases as the number of pulses increases.

Also, as the applied voltage increases, the concentration of organic matter (carbon or nitrogen) at the contact surface formed between the thermochromic layer and the substrate increases. At low voltage, for example 1,400V, the concentration of organic matter increases as the number of pulses increases. At 2,000V, the concentration of organic matter decreases as the number of pulses increases.

The present invention also relates to a thermochromic optical film and a thermochromic glass utilizing the above-mentioned optical laminate.

The thermochromic optical film of the present invention comprises a coating layer; A polymer substrate formed on the coating layer; A thermochromic layer formed on the polymer substrate and comprising vanadium oxide particles; And a protective layer formed on the thermochromic layer, wherein the adhesive strength between the thermochromic layer and the substrate is 50 N / m or more, the thermochromic layer contains vanadium oxide and an organic material, and satisfies the following general formula To a thermochromic optical film comprising:

[Formula 1]

The thermochromic layer may satisfy the following general formula (2).

[Formula 2]

5? S (%)? 40

The thermochromic layer may further satisfy the following general formula (3).

[Formula 3]

C _opposite <C _contact

In the general formula 3, C _opposite represents the content of carbon atoms measured on the surface, and C _contact represents the content of carbon atoms measured on the contact surface.

The details of the polymer substrate, the thermochromic layer and the protective layer are the same as those of the above-mentioned optical laminate, and a detailed description thereof will be omitted. The coating layer can be used without limitation as long as it can adhere the optical film to another substrate, for example, glass or a transparent polymer substrate. In embodiments, the coating layer may be an adhesive or adhesive layer comprising a tackifier or adhesive. The optical film may further include a liner film for protecting the coating layer.

The use of the optical film of the present invention can be exemplified by a coating film adhered to glass, and the glass adhered to such a film can be used for automobiles, railway vehicles, aircraft, ships and buildings. Glass bonded with a film can be used in addition to these applications. It is preferable that the glass laminated with the film is used for a building or a vehicle. The glass laminated with the film can be used for windshield glass, side glass, rear glass or roof glass of an automobile.

The present invention also relates to a composition comprising: glass; A coating layer formed on the glass phase; A polymer substrate formed on the coating layer; A thermochromic layer formed on the polymer substrate and comprising vanadium oxide particles; And a protective layer formed on the thermochromic layer, wherein the adhesive strength between the thermochromic layer and the substrate is 50 N / m or more,

Wherein the thermochromic layer comprises vanadium oxide and an organic material and satisfies the following general formula 1:

[Formula 1]

In the general formula 1, W _i represents the initial weight of the sample, and W _f represents the weight after heat treatment of the sample at 700 ° C. for 2 hours.

The thermochromic layer may satisfy the following general formula (2).

[Formula 2]

5? S (%)? 40

In the general formula (2), S represents the area ratio of the voids measured by analyzing an image of the upper surface of the sample taken by the image analyzer.

The thermochromic layer may further satisfy the following general formula (3).

[Formula 3]

C _opposite <C _contact

The details of the polymer substrate, the coating layer, the thermochromic layer and the protective layer are the same as those described above, and a detailed description thereof will be omitted. Examples of the glass member include inorganic glass and organic glass (resin glazing). Examples of the inorganic glass include float plate glass, heat ray absorbing plate glass, abrasive plate glass, template glass, and colored glass such as green glass. The organic glass is synthetic resin glass substituted for inorganic glass. Examples of the organic glass (resin glazing) include a polycarbonate plate and a poly (meth) acrylic resin plate. Examples of the poly (meth) acrylic resin plate include a polymethyl (meth) acrylate plate and the like.

Hereinafter, the present invention will be described in detail with reference to the embodiments. However, the embodiments described in the specification and the constitutions shown in the drawings are merely the most preferred embodiments of the present invention, and not all of the technical ideas of the present invention are described. It should be understood that there may be various equivalents and variations that may be substituted at the time of filing.

[Preparation of Coating Solution]

Production Example 1

A first solution was prepared by mixing PVP (weight molecular weight: 40,000) in 15 ml of water to 5% by weight based on the total amount of the ink solution. Ethanol was mixed with 19.1 ml of cellulose so as to be 1% by weight based on the total amount of the ink solution to prepare a second solution. Ultrasonic waves were applied to each of the prepared solutions for 1 hour. In a nitrogen atmosphere, VO ₂ particles were prepared so as to be 25 wt% based on the total amount of the ink solution. The first solution and the second solution were mixed and then mixed and sonicated for 1 hour to prepare a coating ink solution.

Production Example 2

A coating ink solution was prepared in the same manner as in Preparation Example 1 except that 3% by weight of PVP was used.

Production Example 3

A coating ink solution was prepared in the same manner as in Preparation Example 1 except that 6% by weight of PVP was used.

Production Example 4

A coating ink solution was prepared in the same manner as in Preparation Example 1 except that 5% by weight of PVP (Mw: 10,000) was used.

Production Example 5

Except that 5% by weight of PVP (Mw: 360,000) was used as a solvent.

Comparative Preparation Example 1

After mixing 15 ml of water and 19.1 ml of ethanol, 25% by weight of VO ₂ particles were mixed and ultrasonicated to prepare a coating ink solution.

The TSI values of the ink solutions prepared in Comparative Production Example 1 and Production Examples 1 to 5 were measured using a dispersion degree measuring apparatus [TURBISCAN] (sample volume 30 ml, holding time 5 hours, once every 5 minutes, temperature 25 ° C. The results are shown in FIGS. 1 and 2. 1 is a graph showing the degree of dispersion according to the PVP content. Production Examples 1 to 3 using 3 to 6 wt% of PVP than the comparative preparation example (PVP 0 wt%) in which the polymeric dispersant PVP was not used showed better dispersion. In particular, Production Example 1 using 5 wt% of PVP showed the most excellent dispersion. 2 is a graph showing the degree of dispersion according to molecular weight of PVP. It was found that Production Example 1 having a molecular weight of 40,000 of PVP showed better dispersion than Production Examples 4 and 5 having 10,000 and 360,000.

Production Example 6

A coating ink solution was prepared in the same manner as in Preparation Example 1 except that 7.5 ml of water and 28.5 ml of ethanol were used.

Production Example 7

A coating ink solution was prepared in the same manner as in Preparation Example 1, except that 22.5 ml of water and 9.5 ml of ethanol were used.

In the case of Production Example 7 in which the weight ratio of water to ethanol was 3: 1, cellulose as a binder was not completely dissolved. Considering the solubility of cellulose and the like, Production Example 1 was judged to be most appropriate.

[Production of optical laminate]

Example 1

A first solution was prepared by mixing PVP (weight molecular weight: 40,000) in 15 ml of water to 5% by weight based on the total amount of the ink solution. Ethanol was mixed with 19.1 ml of cellulose so as to be 1% by weight based on the total amount of the ink solution to prepare a second solution. Ultrasonic waves were applied to each of the prepared solutions for 1 hour. In a nitrogen atmosphere, VO ₂ particles were prepared so as to be 10 wt% based on the total amount of the ink solution. The first solution and the second solution were mixed, and mixed and sonicated for 1 hour to prepare a coating ink solution. 0.2 ml of the prepared coating solution was coated on a glass substrate through a spin coating apparatus (ACE-200). Before the application, the glass surface was surface-treated through an atmospheric pressure plasma apparatus (IDP-1000) under an oxygen atmosphere. The spin coating was carried out by varying the number of revolutions. First, the ink was dispersed by spinning at 500 rpm for 30 seconds, and the second surface was rotated at 3000 rpm for 30 seconds to remove the residual ink, and the surface was stabilized by rotating the surface at 400 rpm for 30 seconds. The optical sintering apparatus was used to photo-sinter the vanadium dioxide to prepare an optical laminate having a thermochromic layer. The light sintering was performed using a white light applied from a xenon lamp. The applied voltage was 2000 V, the number of pulses was 50, the pulse width was 4 ms, and the sintering atmosphere was atmospheric.

Example 2

An optical laminate was prepared in the same manner as in Example 1 except that 30 wt% of VO ₂ particles were used.

Example 3

An optical laminate was prepared in the same manner as in Example 2 except that 50 wt% of VO ₂ particles were used.

Images obtained by electron microscopy of the thermochromic layer of the optical laminate produced in Examples 1 to 3 are shown in Figs. 3 to 5, respectively. 3 through 5, if the VO ₂ content is too low, the bonding between powders may be insufficient during sintering, and if the VO ₂ content is too high, the transmittance of visible light may decrease.

Example 4

0.2 ml of the coating solution prepared in Production Example 1 was applied onto a glass substrate through a spin coating apparatus (ACE-200). Before the application, the glass surface was surface-treated through an atmospheric pressure plasma apparatus (IDP-1000) under an oxygen atmosphere. The spin coating was carried out by varying the number of revolutions. First, the ink was dispersed by spinning at 500 rpm for 30 seconds, and the second surface was rotated at 3000 rpm for 30 seconds to remove the residual ink, and the surface was stabilized by rotating the surface at 400 rpm for 30 seconds. After coating, the solvent was removed by drying at room temperature for 24 hours. The glass with the coating layer formed thereon was inserted into a tubular furnace and heated at 500 DEG C for 1 hour under a nitrogen atmosphere to sinter the vanadium dioxide in the coating layer to prepare an optical laminate having a thermochromic layer. The thickness of the thermochromic layer produced was about 490 nm.

Example 5

An optical laminate having a thermochromic layer was prepared in the same manner as in Example 4, except that the glass on which the coating layer was formed was heated at 600 ° C for 1 hour to sinter the vanadium dioxide. The thickness of the thermochromic layer produced was about 470 nm.

Example 6

An optical laminate having a thermochromic layer was prepared in the same manner as in Example 4, except that the glass on which the coating layer was formed was heated at 500 캜 for 2 hours to sinter the vanadium dioxide. The thickness of the thermochromic layer produced was about 460 nm.

Example 7

An optical laminate having a thermochromic layer was prepared in the same manner as in Example 4, except that the glass on which the coating layer was formed was heated at 500 캜 for 3 hours to sinter the vanadium dioxide. The thickness of the thermochromic layer produced was about 410 nm.

Example 8

An optical laminate having a thermochromic layer was prepared in the same manner as in Example 4, except that the glass on which the coating layer was formed was heated at 500 ° C for 4 hours to sinter the vanadium dioxide. The thickness of the thermochromic layer produced was about 350 nm.

Example 9

An optical laminate having a thermochromic layer was prepared in the same manner as in Example 4, except that vanadium dioxide was photo-sintered using a light sintering apparatus. The light sintering was performed using a white light applied from a xenon lamp. The applied voltage was 2000 V, the number of pulses was 50, the pulse width was 4 ms, and the sintering atmosphere was atmospheric. The thickness of the thermochromic layer produced was about 1.9 mu m.

Example 10

An optical laminate having a thermochromic layer was prepared in the same manner as in Example 10, except that the number of pulses was changed to 100. The thickness of the thermochromic layer produced was about 1.5 탆.

Example 11

An optical laminate having a thermochromic layer was prepared in the same manner as in Example 10, except that the number of pulses was changed to 150. The thickness of the thermochromic layer was about 800 nm.

Example 12

An optical laminate having a thermochromic layer was prepared in the same manner as in Example 10, except that the number of pulses was changed to 200. The thickness of the thermochromic layer was about 800 nm.

Example 13

0.2 ml of the coating solution prepared in Preparation Example 1 was applied onto a PET substrate through a spin coating apparatus (ACE-200). The spin coating was carried out by varying the number of revolutions. First, the ink was dispersed by spinning at 500 rpm for 30 seconds, and the second surface was rotated at 3000 rpm for 30 seconds to remove the residual ink, and the surface was stabilized by rotating the surface at 400 rpm for 30 seconds. After coating, the solvent was removed by drying at room temperature for 24 hours. The optical sintering was carried out under the same conditions as in Example 9 to prepare an optical laminate having a thermochromic layer. It was confirmed that the thermochromic layer was formed without changing the physical properties of the polymer base material, which is shown in Fig.

Comparative Example 1

A vanadium dioxide layer with a thickness of 500 nm was formed on the glass at 500 DEG C using a sputtering apparatus.

Experimental Example 1 [Adhesive strength of optical laminate]

The adhesive force of the thermochromic layer was measured at a speed of 400 nm / sec using a 6N load cell and a 0.3 mm wide tip using SAICAS (NN-EX, Japan) Respectively. Specifically, a thermochromic layer sintered in 10 X 10 mm glass was used as a sample. When a blade (rake angle 20 °, clearance angle 10 °) is slanted from the surface of the heat discoloration layer to the contact surface and then touches the interface of the substrate at the contact surface, And the thermochromic layer-substrate was separated. The resistance value generated at this time was converted into N / m to calculate the adhesive strength value. The measurement area was the same and the mean value and deviation were calculated based on at least three measurements.

열소결Heat sintering	접착강도Adhesive strength	광소결Light sintering	접착강도Adhesive strength	스퍼터링Sputtering	접착강도Adhesive strength
실시예 4Example 4	67±0.567 ± 0.5	실시예 9Example 9	94±5.594 ± 5.5	비교예 1Comparative Example 1	37±0.537 ± 0.5
실시예 5Example 5	87±087 ± 0	실시예 10Example 10	128±5128 ± 5	--	--
실시예 6Example 6	78±0.578 ± 0.5	실시예 11Example 11	211±3211 ± 3	--	--
실시예 7Example 7	85±185 ± 1	실시예 12Example 12	153±6153 ± 6	--	--
실시예 8Example 8	73±0.573 ± 0.5	--	--	--	--
측정조건Measuring conditions	접착강도(N/m)Press Load [0.3N], Balance Load [0.030N], Interval [0.2 sec]Adhesive strength (N / m) Press Load [0.3N], Balance Load [0.030N], Interval [0.2 sec]

As shown in Table 1, it was confirmed that the thermochromic layer formed through the heat treatment or photo-sintering by forming the coating layer through the solution process had an excellent adhesive strength even at a thinner thickness than the thermochromic layer formed through the vapor phase process.

Experimental Example 2 [Measurement of porosity (area ratio of pores) of optical laminate]

In order to measure the area ratio of the voids to the optical stacks prepared in Examples 10 and 11, the porosity of the images obtained from the FE-SEM was calculated using the Image J program. Images taken at 5,000 magnification are shown in FIGS. 7 and 8. FIG. The void area ratio of Example 10 was measured to be 29.66%, and the void area ratio of Example 11 was measured to be 38.35%.

As shown in FIGS. 7 and 8, a thermochromic layer formed by forming a coating layer through a solution process and photo-sintering can control the porosity, and the thickness of the layer formed by the gas phase process such as sputtering It was confirmed that the visible light transmittance can be controlled even if the thickness is thick.

Experimental Example 3 [Measurement of Weight Reduction Rate (VO ₂ Content) of Optical Laminate]

The weight of the optical laminate prepared in Examples 11 and 12 was measured, W _i of the general formula 2 was measured, the sample was heat-treated at 700 for 2 hours, and the weight was measured to determine W _f . The weight reduction rate was calculated accordingly.

The weight reduction rates of Examples 11 and 12 were calculated as 79.71% and 86.86%, respectively. This means that the contents of vanadium dioxide particles, which are inorganic substances in the thermochromic layers of Examples 11 and 12, are about 79.71% and 86.86%, respectively.

Experimental Example 4 [Measurement of transmittance of optical laminate]

The transmittance of the optical laminate prepared in Example 11 was measured with a UV-VIS light amount measuring system (scan rate 1 nm / sec) and the results are shown in Table 2. [

	P_max P _max	BP_min BP _min	OP_min OP _min	ΔIRΔIR
실시예 11Example 11	43.57%43.57%	75.30%75.30%	41.08%41.08%	34.22%34.22%
비고Remarks	P_max: 200 내지 800nm 영역에서 투과도의 최대값BP_min: 25℃에서 2000 내지 3000nm 영역에서 투과도의 최소값OP_min: 80℃에서 2000 내지 3000nm 영역에서 투과도의 최소값ΔIR = (BP_min - OP_min)P _max : maximum value of transmittance in the range of 200 to 800 nm BP _min : minimum value of transmittance in the range of 2000 to 3000 nm at 25 캜 OP _min : minimum value of transmittance in the range of 2000 to 3000 nm at 80 캜 = (BP _min - OP _min )

Experimental Example 5 [Measurement of organic substance concentration in optical laminate]

The organic layer concentration in the direction of depth of the optical laminate prepared in Examples 4 and 6 was measured using XPS equipped with an AES apparatus. The results are shown in FIGS. 9 and 10, respectively. Specifically, the substrate on which the thermochromic layer was formed was sampled at a size of 5 × 5 mm, and the Ar gas was collided from the surface to the depth direction to etch the thin film, and the concentration change of the detected elements was analyzed. Using a beam power of 4 keV, a total of 180 times was measured once every 50 seconds under an etch rate of about 0.39 nm / sec, an etch area of 4 X 2 mm, and a detecting area of 400 μm.

As shown in FIG. 7, the coating layer is formed through a solution process, and the thermochromic layer formed through photo-sintering has a higher carbon content from the surface to the contact surface, so that the organic concentration of the contact surface is higher than the organic concentration of the surface. I could confirm the big thing. On the other hand, as shown in FIG. 8, it can be confirmed that the organic substance concentration on the surface and the contact surface is not greatly different in Example 6 which is heat-sintered.

Claims

materials; And

And a thermochromic layer formed on the substrate,

The bonding strength between the heat-coloring layer and the substrate is 50 N / m or more,

Wherein the thermochromic layer comprises vanadium oxide and an organic material, and satisfies the following general formula 1:

[Formula 1]

In the general formula 1, W i represents the initial weight of the sample, and W f represents the weight after heat treatment of the sample at 700 ° C. for 2 hours.
The method according to claim 1,

Wherein the thermochromic layer satisfies the following general formula (2): < EMI ID =

[Formula 2]

5? S (%)? 40

In the general formula (2), S represents the area ratio of the voids measured by analyzing an image of the upper surface of the sample taken by the image analyzer.
The method according to claim 1,

Wherein the thermochromic layer satisfies the following general formula (3): < EMI ID =

[Formula 3]

C opposite <C contact

In the general formula 3, C opposite represents the content of carbon atoms measured on the surface, and C contact represents the content of carbon atoms measured on the contact surface.
The method according to claim 1,

Wherein the substrate has an average transmittance of 80% or more in a visible light region.
The method according to claim 1,

Wherein the substrate is glass, quartz or a polymer film.
6. The method of claim 5,

Wherein the polymer film is a polyolefin film, a polyester film, a polyvinyl chloride film, or a cellulose film.
6. The method of claim 5,

The polymer film is stretched in more than one axis and has an export rate of less than 3% upon exposure to 120 < 0 > C for 1 hour.
The method according to claim 1,

Wherein the laminate has a maximum value of transmittance of 40% or more in the region of 200 to 800 nm.
The method according to claim 1,

Wherein the laminate has a minimum value of transmittance of 50% or less in the region of 2000 to 3000 nm at any temperature above the critical temperature.
The method according to claim 1,

The laminate is an optical laminate satisfying the following general formula (4)

[Formula 4]

BP min - OP min ≥ 20

In the formula (4), BP min represents the minimum value of the transmittance at 2000 to 3000 nm at any temperature below the critical temperature, and OP min represents the minimum value of the transmittance at 2000 to 3000 nm at any temperature above the critical temperature.
The method according to claim 1,

Wherein the vanadium oxide particles comprise rutile vanadium dioxide having an average diameter of 1 to 500 nm.
The method according to claim 1,

Wherein the thickness of the thermochromic layer is 0.1 to 5 占 퐉.
Applying a solution containing vanadium oxide particles on a substrate to form a coating layer;

Removing solvent from the application layer; And

And sintering the vanadium oxide particles contained in the coating layer.
14. The method of claim 13,

The solution containing the vanadium oxide particles may be a vanadium oxide particle; menstruum; Polymer dispersant; And a binder, wherein the polymer dispersant has a molecular weight of 10,000 to 360,000 and a viscosity of 1 to 100 cP.
15. The method of claim 14,

Wherein the content of the polymer dispersant is 1 to 10% by weight based on the total weight of the composition.
15. The method of claim 14,

Wherein the content of the binder is 0.1 to 3% by weight based on the total weight of the solution composition.
15. The method of claim 14,

Wherein the solvent is a mixture of water and an alcohol.
18. The method of claim 17,

Water and alcohol weight ratio of 1: 0.5 to 1.5.
15. The method of claim 14,

Wherein the content of the vanadium oxide particles is 1 to 50% by weight based on the total weight of the solution composition.
14. The method of claim 13,

Wherein the step of forming the coating layer is performed by spin coating or spray coating.
Coating layer;

A polymer substrate formed on the coating layer;

A thermochromic layer formed on the polymer substrate and comprising vanadium oxide particles; And

And a protective layer formed on the thermochromic layer,

The bonding strength between the heat-coloring layer and the substrate is 50 N / m or more,

Wherein the thermochromic layer comprises vanadium oxide and an organic material and satisfies the following general formula 1:

[Formula 1]

W i represents the initial weight of the sample, and W f represents the weight after heat treatment of the sample at 700 ° C. for 2 hours.
22. The method of claim 21,

Wherein the thermochromic layer satisfies the following general formula 2:

[Formula 2]

5? S (%)? 40

In the general formula (2), S represents the area ratio of the voids measured by analyzing an image of the upper surface of the sample taken by the image analyzer.
22. The method of claim 21,

Wherein the thermochromic layer satisfies the following general formula (3): < EMI ID =

[Formula 3]

C opposite <C contact

In the general formula 3, C opposite represents the content of carbon atoms measured on the surface, and C contact represents the content of carbon atoms measured on the contact surface.
Glass;

A coating layer formed on the glass phase;

A polymer substrate formed on the coating layer;

A thermochromic layer formed on the polymer substrate and comprising vanadium oxide particles; And

And a protective layer formed on the thermochromic layer,

The bonding strength between the heat-coloring layer and the substrate is 50 N / m or more,

Wherein the thermochromic layer comprises vanadium oxide and an organic material, the thermochromic glass satisfying the following general formula 1:

[Formula 1]

In the general formula 1, W i represents the initial weight of the sample, and W f represents the weight after heat treatment of the sample at 700 ° C. for 2 hours.
25. The method of claim 24,

Wherein the thermochromic layer satisfies the following general formula 2:

[Formula 2]

5? S (%)? 40

In the general formula (2), S represents the area ratio of the voids measured by analyzing an image of the upper surface of the sample taken by the image analyzer.
25. The method of claim 24,

Wherein the thermochromic layer satisfies the following general formula 3:

[Formula 3]

C opposite <C contact

In the general formula 3, C opposite represents the content of carbon atoms measured on the surface, and C contact represents the content of carbon atoms measured on the contact surface.