KR101152434B1 - Smart window device and manufacturing method thereof - Google Patents

Abstract

The present invention comprises a top plate and a bottom plate made of a transparent polymer substrate; An upper electrode layer formed on one surface of the upper plate and transparent and conductive; A lower electrode layer formed on one surface of the lower plate and transparent and conductive; And a polymer dispersed liquid crystal (PDLC) panel including a polymer dispersed liquid crystal layer interposed between the upper electrode layer and the lower electrode layer. An adhesive sheet attached to one surface of the polymer dispersed liquid crystal (PDLC) panel to attach and detach the polymer dispersed liquid crystal panel to a desired surface; And a controller electrically connected to the upper electrode layer and the lower electrode layer to control driving of the upper electrode layer and the lower electrode layer, wherein at least one of the upper electrode layer and the lower electrode layer comprises a plurality of split electrodes and a manufacture thereof. Provide a method.

Description

SMART WINDOW DEVICE AND MANUFACTURING METHOD THEREOF {SMART WINDOW DEVICE AND MANUFACTURING METHOD THEREOF}

The present invention relates to a smart window and a method of manufacturing the same. More particularly, the present invention relates to a smart window and a method of manufacturing the same, which can be detached and attached and can implement a blind effect by controlling a driving area.

A smart window refers to a window manufactured to freely control the transmittance of sunlight, and is also called an electronic curtain, a variable transmittance glass, a dimming glass, or the like.

Conventionally, in order to control the transmittance of sunlight flowing into the room through glass, a method of making colored glass by adding colored oxide to the glass composition, or attaching film paper having a specific transmittance to the glass surface has been used. However, these conventional methods do not have an active control function for sunlight and are a passive method of selectively shielding or transmitting only in a certain light wavelength region.

The smart window is to solve such a conventional problem, and is an active product that can artificially adjust light transmittance and color, and is currently recognized as one of the next generation products in the glass field.

The smart window may be classified into liquid crystal (LC), polarized particle dispersion, electrochromic, photochromium, and thermochromium according to the type of material. On the other hand, polymer dispersed liquid crystals (PDLC) among the above liquid crystal materials are particularly attracting attention in that they are easy to be enlarged.

1 is a cross-sectional view of a smart window using a conventional polymer dispersed liquid crystal.

In the smart window using the conventional polymer dispersed liquid crystal, an ITO thin film 12 is formed on one surface of the transparent polymer film 11, the polymer dispersed liquid crystal layer 15 is stacked thereon, and then the ITO thin film 12 ′ is formed thereon. The PDLC film prepared by the method of stacking the formed polymer film 11 'is laminated to a glass bonding sheet 20 such as EVA (Ethylene-Vinyl Acetate, ethylene-vinyl acetate) or PVB (Polyvinyl Butyral, polyvinyl butyral). 20 ') to bond between two glass substrates 30 and 30'.

Such a smart window using a polymer dispersed liquid crystal has a problem in that a manufacturing process is complicated and a high incidence of defects is generated in the process of inserting a PDLC film into glass. In addition, when installing on existing windows or when defects occur in existing installed products and need to be replaced, there is a problem in that construction and maintenance and maintenance are difficult and uneconomical because glass must be replaced entirely.

On the other hand, in the case of the conventional smart window, the light transmittance of the entire window is changed depending on whether the power is applied, there is no product that makes only a partial region transparent or opaque. However, when using such a conventional product, since the entire window must be discolored, there is a problem that the response speed is slow and the use efficiency is lowered.

The present invention has been made to solve the above problems, and an object thereof is to provide a detachable and attachable smart window device and a method of manufacturing the same, which can be easily applied to an existing window without replacing the glass.

In addition, an object of the present invention is to provide a smart window device and a method of manufacturing the same that can be selectively adjusted by the user by dividing the electrode layer.

To this end, the present invention is a top plate and a bottom plate made of a transparent polymer substrate, formed on one surface of the top plate, a transparent and conductive upper electrode layer, formed on one surface of the lower plate, a transparent and conductive lower electrode layer, and the upper electrode layer And a polymer dispersed liquid crystal (PDLC) panel including a polymer dispersed liquid crystal layer interposed between the lower electrode layers. An adhesive sheet attached to one surface of the polymer dispersed liquid crystal (PDLC) panel to attach and detach the polymer dispersed liquid crystal panel to a desired surface; And a controller electrically connected to the upper electrode layer and the lower electrode layer to control driving of the upper electrode layer and the lower electrode layer, wherein at least one of the upper electrode layer and the lower electrode layer comprises a plurality of split electrodes. .

At this time, the top plate has a surface hardness of 2H or more, preferably 2H to 3H or so.

In this case, the adhesive sheet comprises a base film, a first adhesive layer formed on one surface of the base film, a second adhesive layer formed on the other surface of the base film, and a release paper attached on the second adhesive layer. In this case, the peeling force of the first adhesive layer and the second adhesive layer is different from each other.

At this time, the first adhesive layer has a peel force of 400g / 25mm or more, preferably 400g / 25mm to 600g / 25mm, and the second adhesive layer has a peeling force of 3-12g / 25mm, preferably 6-7g / It is good to be about 25mm.

On the other hand, the first adhesive layer is made of an acrylic pressure sensitive adhesive as a main component, the second adhesive layer is preferably made of a silicone pressure sensitive adhesive as a main component.

In addition, at least one of the first adhesive layer and the second adhesive layer may further include an antistatic agent and / or a UV absorbing material.

The smart window device may further include a hard coating layer for securing durability and scratch resistance, and may further include a UV absorbing layer for preventing the adhesive layer or the liquid crystal layer from being damaged by ultraviolet rays.

On the other hand, the split electrode may be formed in a stripe form or a lattice form, wherein the interval between the split electrodes is preferably about 30 to 120㎛.

In another aspect, the present invention comprises the steps of preparing a top plate and a bottom plate coated with a transparent electrode layer on each side, forming a split electrode by laser etching at least one of the top and bottom transparent electrode layers, and the top and bottom plates Preparing a polymer dispersed liquid crystal panel comprising forming a polymer dispersed liquid crystal layer therebetween; Forming a first adhesive layer and a second adhesive layer having different peeling forces on both sides of the base film, and attaching a release paper on the first adhesive layer and the second adhesive layer, respectively. Manufacturing; And attaching the adhesive sheet to one surface of the polymer dispersed liquid crystal panel while removing the release paper adhered on the first adhesive layer of the adhesive sheet.

At this time, the upper plate and the lower plate may be made of a polyester film, polycarbonate film, polymethyl methacrylate or polyethylene naphthalate film.

The first adhesive layer preferably contains an acrylic pressure sensitive adhesive, and the second adhesive layer preferably comprises a silicone pressure sensitive adhesive.

In addition, it is preferable that at least one of the first adhesive layer and the second adhesive layer further includes an antistatic agent and / or a UV absorbing material.

In addition, the manufacturing method of the smart window device of the present invention may further comprise the step of forming a hard coating layer and / or a UV absorbing layer on one surface of the polymer dispersed liquid crystal panel.

In addition, the step of forming the split electrode provides a method of manufacturing a detachable, attachable smart window device, characterized in that performed by a fiber laser.

Smart window device of the present invention is configured to be attached to, detached from the glass window is already installed, there is an advantage that the installation and replacement is easy.

In addition, since the smart window device of the present invention includes a split electrode that is driven independently, it is possible to implement a blind effect to independently control the light transmittance for each region. In addition, a character or a graphic can be displayed by the method of patterning an electrode to a desired form at the time of electrode division.

In addition, the present invention by controlling the laser etching conditions, it is possible to provide a visually excellent smart window by minimizing the gap between the split electrodes. In addition, the fiber laser can be used to minimize the damage of the polymer film during laser etching.

In addition, the present invention is to form a hard coating layer on one surface of the polymer dispersed liquid crystal panel, it is possible to improve the durability of the product.

In addition, the present invention added an antistatic agent to the pressure-sensitive adhesive layer, it was possible to prevent the pressure-sensitive adhesive layer from being contaminated by foreign matters, to reduce the adhesion.

In addition, the present invention to form a UV absorbing coating layer, it is possible to prevent the yellowing phenomenon caused by UV.

1 is a view for explaining a conventional smart window device.
2 is a perspective view for explaining a smart window device of the present invention.
3 is a cross-sectional view showing an embodiment of the smart window device of the present invention.
4 is a cross-sectional view showing another embodiment of the smart window device of the present invention.
5 is a photograph showing the attachment state of the smart window device manufactured by the embodiment.
Figure 6 is a photograph showing the attachment state of the smart window device manufactured by Comparative Example 1.
7 is a photograph of the surface of the smart window device manufactured by the embodiment in the power off state.
8 is a photograph of the surface of the smart window device manufactured by Comparative Example 2 in the power off state.
9 is a picture showing a driving state of the smart window of the present invention.

Hereinafter, the present invention will be described more specifically.

First, the smart window device according to the present invention will be described.

2 to 4 are diagrams for explaining the smart window device of the present invention. 2 is a perspective view of the smart window device of the present invention, Figures 3 and 4 are cross-sectional views.

2 to 4, the smart window device of the present invention includes a polymer dispersed liquid crystal panel 100, an adhesive sheet 200, and a controller 300.

(1) polymer dispersed liquid crystal panel (100)

First, the configuration of the polymer dispersed liquid crystal panel will be described.

The polymer dispersed liquid crystal panel of the present invention includes an upper plate 110, a lower plate 170, an upper electrode layer 120, a lower electrode layer 160, and a polymer dispersed liquid crystal layer 150.

At this time, the upper plate 110 and the lower plate 170 is made of a light-transmitting polymer substrate, for example, polyester (Polyester, PET), polycarbonate (polycarbonate, PC), polymethyl methacrylate (Polymethylmethacrylate, PMMA ), A polymer film made of a transparent material such as polyethylene naphthalate (PEN) may be used. In particular, a polyester film is preferably used.

As described above, the conventional smart window is used by bonding the glass substrate again to the outside of the two polymer films in which the polymer dispersed liquid crystal layer is sandwiched, whereas the smart window device of the present invention does not use the glass substrate. Thus, since this invention does not use a glass substrate, it does not need to go through a complicated glass bonding process.

At this time, the top plate is preferably a surface hardness of 2H or more, more preferably about 2H to 3H. This is because when the surface hardness of the top plate is less than 2H, it is easily damaged. In the case of a general PDLC film, the surface hardness could not be used alone as much as about 1H, and has been used by laminating inside the glass. However, in the case of the present invention by using a substrate having a surface hardness of 2H or more as a top plate material exposed to the outside, it was possible to implement a smart window device consisting of only the film without glass. The top plate having a surface hardness of 2H or more may be provided by using a plastic film made of a material having high hardness, or by forming a hard coating layer on an existing plastic film.

On the other hand, the upper plate 110 and the lower plate 170 are each coated with a transparent electrode layer on one surface. In the present invention, for convenience, the transparent electrode layer coated on the upper plate 110 is referred to as the upper electrode layer 120 and the transparent electrode layer coated on the lower plate 170 is referred to as the lower electrode layer 160. The upper electrode layer 120 and the lower electrode layer 160 are formed on a surface in contact with the polymer dispersed liquid crystal layer 150 to perform a function of applying a voltage to the polymer dispersed liquid crystal layer.

The upper electrode layer 120 and the lower electrode layer 160 are formed on ITO, IZO, ATO, graphene, PEDOT (Poly 3,4-EthyleneDiOxyThiophene), CNT (Carbon Nano Tube, Carbon nanotubes), or the like, by depositing or coating a transparent electrode material. Since a method of forming a transparent electrode on a substrate is well known in the art, those skilled in the art will be able to form the upper electrode layer and the lower electrode layer with no difficulty by referring to the prior art and the description of the specification. .

Meanwhile, in the present invention, at least one of the upper electrode layer 120 and the lower electrode layer 160 may be formed of a plurality of split electrodes. When the electrode layer is formed as a split electrode as described above, each of the electrodes is driven independently to selectively implement a region (transparent region) through which light is transmitted and an region (opaque region) through which light is not transmitted within one smart window. There is an advantage that it can.

As described above, the electrode layer formed of a plurality of split electrodes may be formed by etching the transparent electrode layer using a laser.

In this case, the split electrode may be formed in various patterns, for example, a grid pattern, a sprite pattern, or the like, and may be formed in a pattern capable of implementing characters or graphics, if necessary.

On the other hand, when the split electrodes are formed in a sprite or a lattice pattern, the spacing between the split electrodes is preferably about 30 to 120 µm. If the electrode spacing is less than 30 μm, the laser irradiation dose is high, which may cause damage to the polymer substrate, which may result in black marks (carbonization marks), and the electrode spacing may be too narrow, which may cause energization. It may not be driven. On the other hand, since the electric field is not formed in the gap between the split electrodes, the opaque state is always maintained regardless of whether or not a voltage is applied. Therefore, the spacing between the split electrodes is preferably 120 µm or less, which is not visually recognized.

On the other hand, the spacing between the divided electrodes is more preferably about 60 to 100㎛, especially about 80 to 100㎛. This is because when the gap between the split electrodes is within the above range, laser etching is easy and manufacturing is simple.

On the other hand, the laser etching is preferably made using a fiber laser. Using a fiber laser as the laser source minimizes the thermal effects (damage) on the top and / or bottom plates compared to other laser sources, and lasers from other sources will vary the distance between the laser source and the lens. While the line width changes every time, the Filber laser does not change the line width, which is advantageous in setting working conditions.

On the other hand, the laser etching conditions vary depending on the spacing, etching depth, etc. of the split electrodes to be formed. For example, the present invention is not limited thereto, but laser etching is preferably performed under conditions of a laser output 20 W, a laser wavelength 1064 nm, a pulse output method, and a frequency band 20 kHz to 80 kHz.

Next, the polymer dispersed liquid crystal layer 150 includes liquid crystal particles 130 and a photosensitive polymer 140 solution. When the ultraviolet light is irradiated onto the polymer dispersed liquid crystal layer 150, the photosensitive polymer 140 is cured, and a plurality of pores are generated in the polymer dispersed layer, and the liquid crystal particles 130 are included in the pores. In the state in which no voltage is applied, since the polymer molecules 140 and the liquid crystal particles 130 surrounding the liquid crystal are randomly arranged, light cannot be transmitted and is scattered to form an opaque state. However, when a voltage is applied, the liquid crystals are polarized and arranged with regularity, and polymer molecules are also arranged along its transmission axis. As such, when the liquid crystal and the polymer molecules have a constant arrangement, light incident on the panel is transmitted, resulting in a transparent state. Accordingly, light transmittance may be controlled by applying a voltage to the upper electrode layer 120 and the lower electrode layer 160 to form an electric field.

In the case of the present invention, for example, a polyvinyl alcohol-based, epoxy-based, or urethane acrylate-based polymer matrix may be used as the photosensitive polymer 140, and the liquid crystal particles 130 may be, for example, cyano. -Cyano-Biphenyl series liquid crystal mixed with a single liquid crystal, biphenyl mesogen mixed with a single liquid crystal substituted with fluorine, tertiary phenyl (Ter-Phenyl) and biphenyl ( A mixed liquid crystal in which Biphenyl) series single liquid crystals are mixed may be used.

On the other hand, it is preferable that the polymer dispersed liquid crystal layer 150 contains a surfactant. As the surfactant, but not limited thereto, for example, stearyl methacrylate may be used. When the surfactant is added to the polymer dispersed liquid crystal layer, since the orientation change of the polymer and the liquid crystal can be made more easily when voltage is applied, the driving voltage can be lowered.

(2) adhesive sheet (200)

Smart window device of the present invention is characterized in that the adhesive sheet is attached to one surface of the polymer dispersed liquid crystal panel 100 made as described above. The adhesive sheet 200 is for allowing the polymer dispersed liquid crystal panel 100 to be detached and attached to a desired surface, for example, an existing glass window.

At this time, the pressure-sensitive adhesive sheet 200 is made of a pressure-sensitive adhesive layer having an adhesive force to attach the polymer dispersed liquid crystal panel 100 to a desired surface, but is not limited thereto. As shown in the drawing, the base film 210, the first adhesive layer 220, the second adhesive layer 230, and a release paper 240 are included.

As the base film 210, a transparent polymer material film, for example, a polyethylene terephthalate (PET) film or the like may be used, and the thickness of the base film 210 may be about 10 to 100 μm. If the thickness of the base film exceeds 100㎛, not only the thickness of the product is thick, but also the optical properties deteriorate. On the other hand, although the thickness of a base film is so preferable that it is thin, it is preferable that it is 10 micrometers or more in view of the manufacturing process, economical efficiency, etc. of a base film.

Next, the first adhesive layer 220 is formed on one side of the base film 210, in particular, on the side of the PDLC panel, but is not limited thereto, but is not limited thereto, but may be an acrylic adhesive, particularly an acrylate copolymer or methacrylate air. It is preferable that it is an acrylic adhesive which has coalescence or a combination thereof as a main component.

At this time, the first adhesive layer is preferably a peel force (peel force measurement conditions: 300mm / min, 2kg standard roller) is 400g / 25mm or more, preferably 400g / 25mm to 600g / 25mm. This is because when the peeling force is less than 400g / 25mm, sufficient adhesive strength cannot be secured, and the adhesive layer may drop during long-term storage in roll state, and when it exceeds 600g / 25mm, it is difficult to remove and reinstall. .

The second adhesive layer 230 is formed on the other surface of the base film 210, that is, on the opposite surface of the surface on which the first adhesive layer is formed, but is not limited thereto. It is preferable that it is a silicone type adhesive which consists of resin etc. as a main component.

At this time, the peel force of the second adhesive layer (peel force measurement conditions: 300mm / min, 2kg standard roller) is preferably 3g / 25mm to 12g / 25mm, most preferably about 6 to 7g / 25mm. This is because when the peeling force of the second adhesive layer is less than 3 g / 25 mm, sufficient adhesiveness cannot be secured, and when the second adhesive layer exceeds 12 g / 25 mm, it is difficult to remove or remove bubbles during construction.

On the other hand, the release paper 250 is used to protect the adhesive surface of the pressure-sensitive adhesive, adhesives, adhesives, etc., is attached on the second adhesive layer. When the release paper 250 is attached, foreign matters may be adsorbed on the adhesive layer, thereby preventing the adhesion force from being lowered, and the transport and storage may be easily performed.

Meanwhile, antistatic treatment may be performed on the release paper as needed. The antistatic treatment may be performed by coating a surface of a release paper using a resin composition including an antistatic agent or adding an antistatic agent to the inside of the release paper.

Thus, when using the antistatic treated release paper, there is an advantage that the workability is excellent. When the smart window device of the present invention is constructed by peeling off the release paper and attaching an adhesive layer to a glass window or the like, a state in which foreign matter easily adheres to the adhesive layer is created by a peeling electrification voltage generated when the release paper is peeled off. As a result, there is a problem in that contamination due to foreign matters in the construction process, adhesiveness is also lowered, resulting in bubbles, such as appearance is not good after construction. However, when the antistatic treatment is performed on the release paper, since the peeling electrification voltage is remarkably reduced, problems such as contamination at the time of construction, bubble generation, and lowering of adhesive strength can be solved. Meanwhile, the antistatic agent is not particularly limited, but a lithium-amide antistatic agent, a polyester antistatic agent, or the like may be used.

The adhesive sheet 200 of the present invention made as described above is characterized in that the peeling force is different from each other by using different adhesives in the first adhesive layer and the second adhesive layer. A relatively strong peeling force was used for the first adhesive layer attached to the PDLC panel to prevent separation of the PDLC panel and the adhesive sheet. On the other hand, a relatively weak adhesive force was used for the second adhesive layer to be attached to the glass window, etc., in order to increase workability and to facilitate detachment and attachment. This is because when the adhesive strength is too strong, it is difficult to install when attaching to a window or the like, and it is difficult to detach in the future.

Meanwhile, at least one of the first adhesive layer and the second adhesive layer may further include an antistatic agent and / or a UV absorbing material. More preferably, the antistatic agent and / or the UV absorbing material is included in the first adhesive layer.

The antistatic agent is to prevent the static electricity generated in the adhesive layer to be contaminated by foreign matter. If the adhesive layer is contaminated by foreign matter, the adhesive force is lowered, and the polymer dispersed liquid crystal panel cannot be firmly attached to the glass window or the like. Therefore, it is preferable to include an antistatic agent in the adhesive layer in order to reduce such foreign matter contamination. The antistatic agent is not particularly limited, but a lithium-amide antistatic agent, a polyester antistatic agent, or the like may be used.

On the other hand, the UV absorbing material is to prevent the yellowing of the liquid crystal layer and / or the adhesive layer by ultraviolet light, but is not limited thereto, for example, phenyl salicylates (Bhenphenicy), benzophenone (Benzophenone), Benzotriazole and the like can be used.

As described above, unlike the conventional smart window device, the smart window device of the present invention having the adhesive sheet attached to one surface does not need to replace the glass as a whole. The smart window device of the present invention can be easily installed by removing the release paper and then attaching the adhesive sheet to the glass. Since the smart window device of the present invention does not include a glass substrate and uses only a light polymer film substrate, the smart window device may be sufficiently attached even with an adhesive layer.

Therefore, when the product is damaged or tired, instead of replacing the entire glass, the smart window device of the present invention attached to the glass surface may be removed and a new smart window device may be attached. It is economical.

(3) controller (300)

On the other hand, the smart window device of the present invention includes a controller 300 for controlling the driving of the upper electrode 120 and the lower electrode 160. The controller 300 is electrically connected to the upper electrode layer 120 and the lower electrode layer 160, and independently controls driving of each of the split electrodes, thereby allowing light to pass through in one smart window (transparent area). ) And the area where the light is not transmitted (opaque area) can be selectively implemented.

The method of electrically connecting the controller and the electrode layer of the polymer dispersed liquid crystal panel is well known in the art, and the smart window device of the present invention can also electrically connect the electrode layer of the controller and the polymer dispersed liquid crystal panel using the conventional method. have. For example, the controller and the electrode layers of the polymer dispersed liquid crystal panel can be electrically connected using well-known connection means such as FPCB (Flexible Printed Circuit Board).

Although not shown, the controller is preferably provided with a cable connected to an external power supply. In addition, the controller preferably further includes a transformer for converting 220V into a transformer, for example, 220V into 110V. If the transformer is included, there is an advantage that can be used regardless of the voltage of the power source provided in the building or home to be installed. In addition, since it is not necessary to provide a separate power supply, there is an advantage that the device can be formed slim, and the installation and maintenance are simple. On the other hand, for this purpose it is preferably provided with a cable for connecting the controller and the power supply.

Meanwhile, as illustrated in FIG. 4, the smart window device of the present invention further includes a hard coating layer 400 on the top surface of the polymer dispersed liquid crystal panel 100 to protect the product from scratches and the like. can do.

The hard coating layer may be formed by applying a UV curable or thermosetting resin, for example, epoxy, polyester-based acrylic resin (UV curable type) or silicone resin (thermosetting type), and then curing the upper plate surface. For example, spray coating or roll coating may be formed by microgravure coating or the like.

On the other hand, instead of forming the hard coating layer directly by the above method, it is also possible to purchase and use a film having a hard coating layer formed.

In addition, the smart window device of the present invention, if necessary, it is preferable to form a UV absorbing coating layer 500 for preventing the liquid crystal layer and / or the adhesive layer from yellowing by ultraviolet rays. On the other hand, the UV absorbing coating layer is preferably formed between the lower plate and the adhesive sheet, a UV absorbing material such as phenyl salicylates (Phenyl Salicylates), benzophenone, Benzotriazole (Benzotriazole), etc. After that, it may be formed by coating, curing, or the like using the same, or may be formed by bonding a commercially available UV blocking film to the bottom of the smart window.

In addition, if necessary, the smart window of the present invention may further include an infrared blocking layer for imparting heat insulation and energy saving functions.

9 is a picture showing a driving example of the smart window device of the present invention configured as described above. (A) is a picture showing when the power is off, (B) and (C) is a picture showing when the power is on. As shown in FIG. 9, the smart window device of the present invention is opaque in the power-off state and becomes transparent in the power-on state. On the other hand, in particular, the smart window device of the present invention is configured to perform a partially transparent blind function by dividing the electrode layer, as shown in (C).

<Manufacturing Method>

Hereinafter, a method of manufacturing the smart window device of the present invention will be described.

The manufacturing method of the smart window device of the present invention includes the steps of (1) preparing a polymer dispersed liquid crystal panel, (2) preparing a adhesive sheet, and (3) attaching an adhesive sheet to the polymer dispersed liquid crystal panel. Is done.

(1) Manufacturing Step of Polymer Dispersed Liquid Crystal Panel

First, two polymer substrates each having a transparent electrode layer formed on one surface thereof are prepared. These polymer substrates are used as the upper and lower plates of the polymer dispersed liquid crystal panel, respectively. In this case, the polymer substrate may be used by purchasing a commercially available polymer substrate coated with a transparent electrode layer, or may be prepared by directly coating a transparent electrode layer on one surface of a polymer substrate such as PET. Since the method of coating the transparent electrode layer on the polymer substrate is well known in the art, description thereof will be omitted.

Next, at least one of the upper and lower transparent electrode layers is laser-etched to form a split electrode. At this time, only the transparent electrode layer of one of the upper and lower plates may be etched, or both of the upper and lower transparent electrode layers may be etched.

In this case, the split electrode may be formed in various patterns, for example, a grid pattern, a sprite pattern, or the like, and may be formed in a pattern capable of implementing characters or graphics, if necessary.

On the other hand, when the split electrodes are formed in a sprite or a lattice pattern, the spacing between the split electrodes is preferably about 30 to 120 µm. If the electrode spacing is less than 30 µm, the laser irradiation amount is high, and damage to the polymer substrate is likely to occur, thereby causing black marks (carbonization marks). On the other hand, since the electric field is not formed in the gap between the split electrodes, the opaque state is always maintained regardless of whether or not a voltage is applied. Therefore, the spacing between the split electrodes is preferably 120 µm or less, which is not visually recognized.

On the other hand, in view of the ease of laser etching among the above ranges, the spacing between the split electrodes is preferably 60 to 120 µm, even more preferably about 80 to 100 µm.

On the other hand, the laser etching is preferably made using a fiber laser. Using a fiber laser as the laser source minimizes the thermal effects (damage) on the top and / or bottom plates compared to other laser sources, and lasers from other sources will vary the distance between the laser source and the lens. While the line width changes every time, the Filber laser does not change the line width, which is advantageous in setting working conditions.

On the other hand, the laser etching conditions vary depending on the spacing, etching depth, etc. of the split electrodes to be formed. For example, in the case of the present invention, laser etching may be performed under conditions of a laser output 20 W, a laser wavelength 1064 nm, a pulse output method, and a frequency band 20 kHz to 80 kHz. However, the present invention is not limited thereto.

Next, a polymer dispersed liquid crystal layer is formed between the upper plate and the lower plate. For example, the polymer dispersed liquid crystal layer may be formed by applying a polymer dispersed liquid crystal on the lower plate and curing the same.

(2) Adhesive sheet manufacturing method

Apart from the preparation of the polymer dispersed liquid crystal panel, an adhesive sheet is produced.

First prepare a base film. As the base film, a transparent polymer material film, for example, a polyethylene terephthalate (PET) film may be used.

Then, the first adhesive layer and the second adhesive layer having different peeling force are formed on both surfaces of the prepared base film.

The first adhesive layer and the second adhesive layer having different peeling strengths may be formed by using an adhesive having different adhesive strengths. For example, a first adhesive layer including an acrylic adhesive having a relatively strong adhesive strength as a main component is formed on one surface of the base film, and a silicone adhesive having a relatively weak adhesive strength as a main component is provided on the opposite side of the surface on which the first adhesive layer is formed. By forming the 2nd adhesion layer mentioned above, the 1st adhesion layer and the 2nd adhesion layer which have a mutual peeling force can be formed.

After forming the first adhesive layer and the second adhesive layer, by attaching a release paper on the first adhesive layer and the second adhesive layer, respectively, to prepare an adhesive sheet. In this case, as necessary, at least one of the first adhesive layer and the second adhesive layer may further include a UV absorbing material and / or an antistatic agent.

(3) attaching the adhesive sheet to the polymer dispersed liquid crystal panel

When the polymer dispersed liquid crystal panel and the adhesive sheet are manufactured through the steps (1) and (2), the adhesive sheet is attached to the lower portion of the polymer dispersed liquid crystal panel while removing the release paper adhered on the first adhesive layer of the adhesive sheet. . At this time, the adhesive layer surface exposed by removing the release film is immediately attached to the polymer liquid crystal panel, thereby preventing the adhesive layer from being contaminated by foreign matter.

On the other hand, the smart window device manufacturing method of the present invention, if necessary, may further perform the step of forming at least one of the hard coating layer, UV absorbing layer and infrared blocking layer.

Hard coating layer formation can be carried out by methods well known in the art, for example, UV curable or thermosetting resins, such as epoxy, polyester-based acrylic resin (UV) on the top surface of the polymer dispersed liquid crystal panel Hardening) or silicone resin (thermosetting), and more specifically, for example, spray coating or roll coating may be formed by microgravure coating or the like.

Meanwhile, the UV absorption coating layer may also be formed by a method well known in the art, for example, UV absorption such as phenyl salicylates, benzophenone, benzotriazole, or the like. After the substance is added to the coating liquid or the like, it may be formed by coating or by attaching a commercially available UV blocking film or the like.

Example

After preparing a top plate and a bottom plate each coated with a transparent electrode layer on one surface, the transparent electrode layer of the top plate was laser-etched under the conditions of laser output 20W, laser wavelength 1064nm, pulse output method, and frequency band 20kHz to 80kHz to form an electrode pattern interval of 80 μm. Phosphorus sprite pattern was formed. Then, a polymer dispersed liquid crystal layer was formed between the upper and lower plates to prepare a polymer dispersed liquid crystal panel.

On the other hand, an acrylic pressure-sensitive adhesive was applied to one surface of a 75 μm-thick PET film with a thickness of 32 μm, and a silicone pressure-sensitive adhesive was applied to 30 μm on the other side of the PET film to form a first adhesive layer and a second adhesive layer. Then, a 25 μm thick PET release film was attached on the acrylic adhesive layer, and a 50 μm thick PET release film was attached on the silicone adhesive layer to prepare an adhesive sheet. At this time, the acrylic adhesive layer contained a sunscreen, the peel force was about 500g / 25mm, the peeling force of the silicone adhesive layer was about 7g / 25mm.

While removing the release paper adhered on the first adhesive layer of the pressure-sensitive adhesive sheet, it was attached to one surface of the polymer dispersed liquid crystal panel to manufacture a smart window device.

Comparative Example 1

Except for using an adhesive sheet prepared by applying an acrylic pressure-sensitive adhesive having a peel force of 500 g / 25 mm to 32 μm on one surface of a 75 μm-thick PET film and attaching a 25 μm-thick PET release film thereon. Smart window device was manufactured in the same manner as.

Comparative Example 2

A smart window device was manufactured in the same manner as in Example, except that the electrode pattern spacing was 150 μm during laser etching.

Experimental Example 1

Each of the smart window devices manufactured by Example and Comparative Example 1 was attached to a glass window while removing the release paper attached to the adhesive sheet. After attachment, photographs are shown in FIGS. 5 (Example) and 6 (Comparative Example), respectively.

5 and 6 it can be seen that the smart window device of Comparative Example 1 remains heavily after attachment, while the smart window device of the embodiment is attached cleanly without bubbles.

Experimental Example 2

In the power-off state, the surface of the smart window device of Example and Comparative Example 2 was taken. The photographs taken are shown in FIGS. 7 (Example) and 8 (Comparative Example 2), respectively. As shown in FIGS. 7 and 8, the smart window device of the embodiment does not recognize the electrode pattern, whereas the smart window device of Comparative Example 2 recognizes that the electrode pattern is visually recognized.

100: polymer dispersed liquid crystal panel
200: adhesive sheet
300: controller

Claims (19)

Top and bottom plate made of a transparent polymer substrate,
An upper electrode layer formed on one surface of the upper plate and transparent and conductive;
A lower electrode layer formed on one surface of the lower plate and transparent and conductive;
A polymer dispersed liquid crystal (PDLC) panel comprising a polymer dispersed liquid crystal layer interposed between the upper electrode layer and the lower electrode layer;
An adhesive sheet attached to one surface of the polymer dispersed liquid crystal (PDLC) panel to attach and detach the polymer dispersed liquid crystal panel to a desired surface; And
A controller electrically connected to the upper electrode layer and the lower electrode layer to control driving of the upper electrode layer and the lower electrode layer,
At least one of the upper electrode layer and the lower electrode layer is composed of a plurality of split electrodes,
The spacing between the split electrodes is 30 to 120㎛,
The adhesive sheet is formed on the base film, one surface of the base film, the first adhesive layer having a peel force of 400 to 600g / 25mm and the other surface of the base film, a second peeling force of 3 to 12g / 25mm Smart window device comprising an adhesive layer.
The method of claim 1,
The top plate has a surface hardness of 2H to 3H smart window device.
The method of claim 1,
The adhesive sheet further comprises a release paper attached to the second adhesive layer smart window device.
delete The method of claim 1,
The first adhesive layer is made of an acrylic pressure-sensitive adhesive,
The second adhesive layer is a smart window device made of a silicone pressure-sensitive adhesive.
The method of claim 1,
Smart window device further comprises at least one of a UV absorbing material and an antistatic agent in at least one of the first adhesive layer and the second adhesive layer.
The method of claim 3,
The release paper anti-static smart window device.
The method of claim 1,
The smart window device further comprises a hard coating layer.
The method of claim 1,
The smart window device further comprises a UV absorbing layer.
The method of claim 1,
The smart window device further comprises an infrared blocking layer.
The method of claim 1,
The split electrode is formed in the form of a stripe or a grating smart window device.
delete Preparing an upper plate and a lower plate coated with transparent electrode layers on one surface thereof,
Laser etching at least one of the upper and lower transparent electrode layers to form a split electrode having a spacing of 30 to 120 μm, and
Manufacturing a polymer dispersed liquid crystal panel comprising forming a polymer dispersed liquid crystal layer between the upper and lower plates;
Forming a first adhesive layer having a peel force of 400 to 600 g / 25 mm and a second adhesive layer having a peel force of 3 to 12 g / 25 mm on both sides of the base film, and on the first adhesive layer and the second adhesive layer. Preparing a pressure-sensitive adhesive sheet comprising attaching release papers to each other; And
And attaching the adhesive sheet to one surface of the polymer dispersed liquid crystal panel while removing the release paper adhered on the first adhesive layer of the adhesive sheet.
The method of claim 13,
The upper and lower plates are selected from the group consisting of polyester film, polycarbonate film, polymethyl methacrylate and polyethylene naphthalate film.
The method of claim 13,
The first adhesive layer is a method of manufacturing a smart window device is formed by an acrylic pressure-sensitive adhesive.
The method of claim 13,
The second adhesive layer is a method of manufacturing a smart window device is formed by a silicone adhesive.
The method of claim 13,
At least one of the first adhesive layer and the second adhesive layer further comprises at least one of a UV absorbing material and an antistatic agent.
The method of claim 13,
The method of claim 1, further comprising forming at least one of a hard coating layer, a UV absorbing layer, and an infrared ray blocking layer on one surface of the polymer dispersed liquid crystal panel.
The method of claim 13,
Forming the split electrode is a method of manufacturing a detachable, attachable smart window device, characterized in that performed with a fiber laser.

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