How to Manufacture Smart Window Film to Prevent Side Shorting

Abstract

Generally, a smart window film intended for variable transmittance uses a plastic substrate (PET, PEN, PC, polarizer, etc.) as a base and has a liquid phase (LC, GHLC, cholesteric LC, etc.) capable of variable transmittance in response to an electrical signal disposed between two substrates including a transparent electrode layer (ITO or PEDOT, etc.); it is equipped with a sealant for preventing leakage of the liquid phase and attaching the substrates; and a spacer for maintaining the space between the substrates. These smart window films are used by cutting and attaching electrodes; however, since the substrate used as the base material is made of plastic, there is a possibility that a short circuit may occur when voltage is applied due to the transparent electrodes on the upper and lower substrates coming into contact with each other because of the flexible nature of the plastic substrate, or due to conductive debris, conductive foreign substances, or moisture generated during cutting. Furthermore, a short circuit may also occur due to silver paste applied to the transparent electrode splashing onto the exposed electrode after cutting or due to the attachment of other foreign substances. Such short circuits cause the entire smart window film to be damaged. The present invention relates to a method for manufacturing a smart window film for preventing side short circuits to prevent the occurrence of such short circuits, and a smart window film manufactured by said method.

Description

Technology Field

[0001] Generally, a smart window film intended for variable transmittance uses a plastic substrate (PET, PEN, PC, polarizer, etc.) as a base and has a liquid phase (LC, GHLC, cholesteric LC, etc.) capable of variable transmittance in response to an electrical signal disposed between two substrates including a transparent electrode layer (ITO or PEDOT, etc.); it is equipped with a sealant for preventing leakage of the liquid phase and attaching the substrates; and a spacer for maintaining the space between the substrates.

[0002] These smart window films are used by cutting and attaching electrodes; however, since the substrate used as the base material is made of plastic, there is a possibility that a short circuit may occur when voltage is applied due to the transparent electrodes on the upper and lower substrates coming into contact with each other because of the flexible nature of the plastic substrate, or due to conductive debris, conductive foreign substances, or moisture generated during cutting. Furthermore, a short circuit may also occur due to silver paste applied to the transparent electrode splashing onto the exposed electrode after cutting or due to the attachment of other foreign substances. Such short circuits cause the entire smart window film to be damaged.

[0003] The present invention relates to a method for manufacturing a smart window film for preventing side short circuits to prevent the occurrence of such short circuits, and a smart window film manufactured by said method. Background Technology

[0005] To drive smart window films such as VPLC and PDLC, an external power supply is required. A bus bar is required, which is the part connected when the external power is applied to the smart window film.

[0006] These busbar materials require high electrical conductivity and strong adhesion to smart window films. However, the general method for forming the busbar involves half-cutting the bonded electrodes, followed by silver coating, copper tape attachment, and copper mesh attachment.

[0007] If you want to explain this process in a table, you can refer to [Table 1].

[0008]

[0010] In other words, to form the electrodes of the smart window film, the material is cut into full and half-cut sections and cleaned to attach the external electrodes. At this stage, to enhance the conductivity of the electrodes, a silver paste coating is applied, followed by the attachment of copper tape, and a conductive plate is attached on top to connect an external power source.

[0012] The smart window film configured in this way is formed by laminating an upper plate and a lower plate as shown in Fig. 4. Since the transparent electrode formed on the adjacent surface of the upper plate and the lower plate is exposed after cutting as shown in the bottom of Fig. 4, due to the flexible characteristics of the plastic substrate, there may be cases where the transparent electrodes of the upper and lower substrates, that is, the upper plate and the lower plate, come into contact.

[0013] Alternatively, there is a possibility that a short circuit may occur when voltage is applied due to conductive debris, conductive foreign matter, moisture, etc. generated during cutting.

[0014] In addition, a short circuit may occur due to silver paste applied to the transparent electrode splashing onto the transparent electrode exposed after cutting, or due to the attachment of other foreign substances.

[0015] Such short circuits cause the entire smart window film to be ruined.

[0017] Accordingly, the applicant proposed a method for manufacturing a smart window film to prevent side short circuits in order to prevent the occurrence of such short circuits.

[0019] Meanwhile, Published Patent Application No. 10-2024-0133907 describes "an optical laminate and a method for manufacturing the same, a smart window including the same, and a window for an automobile or building applying the same."

[0020] The above technology relates to a transmittance-variable optical laminate comprising: a first polarizing plate; a first transparent conductive layer formed on one surface of the first polarizing plate; a second polarizing plate facing the first polarizing plate; a second transparent conductive layer formed on one surface of the second polarizing plate and facing the first transparent conductive layer; and a liquid crystal layer provided between the first transparent conductive layer and the second transparent conductive layer, wherein the first transparent conductive layer and the second transparent conductive layer comprise a conductive polymer, the liquid crystal layer comprises a polymer network and a liquid crystal compound, and the liquid crystal compound is arranged with a uniform initial orientation, and a method for manufacturing the same, a smart window comprising the same, and a window for an automobile or building to which the same is applied. Prior art literature

[0022] Published Patent Application No. 10-2024-0133907 (Published September 5, 2024) The problem to be solved

[0023] The objective of the present invention is to manufacture a smart window film that can reduce the possibility of a short circuit occurring in a transparent electrode exposed after cutting, which can be caused by various factors. means of solving the problem

[0025] A method for manufacturing a smart window film for preventing side short according to the present invention, devised to achieve the above-mentioned purpose, and a smart window film manufactured by said method,

[0026] A top plate processing step (S100) for performing processing of the top plate;

[0027] A lower plate processing step (S200) for performing processing of the lower plate;

[0028] A top plate and bottom plate lamination step (S300) for laminating the top plate processed in the top plate processing step (S100) and the bottom plate processed in the bottom plate processing step (S200);

[0029] It is characterized by including a cutting step (S400) that performs cutting along a predetermined line, such as an outer line of the sealant, after the above-mentioned upper and lower plate lamination step (S300).

[0031] At this time, the upper plate processing step (S100) is,

[0032] The method is characterized by the process of preparing a top plate (S110), separating one side of a transparent electrode on the prepared top plate so as to deactivate it (S120), and then scattering a spacer on one side of the top plate (S130).

[0034] In addition, the above lower plate processing step (S200) is,

[0035] The process is characterized by preparing a bottom plate (S210), separating one side of a transparent electrode from the prepared bottom plate so as to deactivate it (S220), then bonding a sealant to one side of the bottom plate (S230), and applying liquid crystal (S240) into the seal line formed by the sealant.

[0037] In addition, deactivating one side of the transparent electrode described above is,

[0038] It is characterized by forming an inactive region by cutting one side of a transparent electrode through laser processing.

[0040] In addition, the above-mentioned deactivation area is,

[0041] It is characterized by being formed so as to overlap with the seal line or be located inside the seal line when the top plate and the bottom plate are laminated. Effects of the invention

[0043] According to the method for manufacturing a smart window film for preventing side short according to the present invention as described above, and the smart window film manufactured by said method,

[0044] During the manufacturing process, one side of the transparent electrode is processed into a laser-deactivated area to prevent short circuits by blocking the transparent electrode at the source, while allowing conduction to the transparent electrode between the top and bottom plates through lamination in the intersecting direction of the top and bottom plates, thereby enabling it to perform its function. Brief explanation of the drawing

[0046] FIG. 1 illustrates a method for manufacturing a smart window film to prevent side short circuits according to the present invention. Figure 2 illustrates a method for manufacturing a smart window film to prevent side short circuits according to Figure 1. FIG. 3 shows a side cross-sectional view of a smart window film manufactured by the method for manufacturing a smart window film to prevent side short according to the present invention. Figure 4 shows a side cross-sectional view of a conventional smart window film. Specific details for implementing the invention

[0047] Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0049] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0051] Before proceeding with the following description with reference to the drawings, it should be noted that matters not necessary to reveal the gist of the invention, namely known configurations that a person skilled in the art with ordinary knowledge can obviously add, have not been illustrated or specifically described.

[0053] Generally, a smart window film intended for variable transmittance uses a plastic substrate (PET, PEN, PC, polarizer, etc.) as a base and has a liquid phase (LC, GHLC, cholesteric LC, etc.) capable of variable transmittance in response to an electrical signal disposed between two substrates including a transparent electrode layer (ITO or PEDOT, etc.); it is equipped with a sealant for preventing leakage of the liquid phase and attaching the substrates; and a spacer for maintaining the space between the substrates.

[0054] These smart window films are used by cutting and attaching electrodes; however, since the substrate used as the base material is made of plastic, there is a possibility that a short circuit may occur when voltage is applied due to the transparent electrodes on the upper and lower substrates coming into contact with each other because of the flexible nature of the plastic substrate, or due to conductive debris, conductive foreign substances, or moisture generated during cutting. Furthermore, a short circuit may also occur due to silver paste applied to the transparent electrode splashing onto the exposed electrode after cutting or due to the attachment of other foreign substances. Such short circuits cause the entire smart window film to be damaged.

[0055] The present invention relates to a method for manufacturing a smart window film for preventing side short circuits to prevent the occurrence of such short circuits, and a smart window film manufactured by said method.

[0057] FIG. 1 shows a method for manufacturing a smart window film for preventing side short circuits according to the present invention, FIG. 2 illustrates the method for manufacturing a smart window film for preventing side short circuits according to FIG. 1, and FIG. 3 shows a cross-sectional view of a smart window film manufactured by the method for manufacturing a smart window film for preventing side short circuits according to the present invention.

[0058] In addition, Fig. 4 shows a side cross-sectional view of a conventional smart window film.

[0060] A method for manufacturing a smart window film for preventing side short according to the present invention according to the attached drawings may refer to Fig. 1 of the attached drawings.

[0061] To elaborate, the method includes a top plate processing step (S100) for processing the top plate and a bottom plate processing step (S200) for processing the bottom plate, and then a top plate and bottom plate lamination step (S300) for laminating the top plate processed in the top plate processing step (S100) and the bottom plate processed in the bottom plate processing step (S200); and a cutting step (S400) for cutting along a predetermined line, such as the outer line of a sealant, after the top plate and bottom plate lamination step (S300).

[0063] At this time, the top plate processing step (S100) comprises the process of preparing a top plate (S110), separating one side of a transparent electrode on the prepared top plate so as to deactivate it (S120), and then spreading a spacer on one side of the top plate (S130).

[0065] In addition, the bottom plate processing step (S200) involves preparing a bottom plate (S210), separating one side of a transparent electrode on the prepared bottom plate so as to deactivate it (S220), and then bonding a sealant to one side of the bottom plate (S230). At this time, the line formed by the bonding of the sealant is referred to as the seal line. Afterwards, the process is finished by applying a liquid crystal coating (S240).

[0067] Subsequently, the top plate prepared through the top plate processing step (S100) and the bottom plate prepared through the bottom plate processing step (S200) are laminated, wherein the lamination is performed such that the transparent electrode of the top plate and the transparent electrode of the bottom plate intersect each other. In other words, the top surface of the top plate and the bottom surface of the bottom plate are laminated so that they face each other. Afterward, cutting is performed, for which refer to Fig. 2 of the attached drawings.

[0069] As shown in Fig. 2 of the attached drawings, a full cut is performed adjacent to the outer side of the seal line, and a half cut is performed on one side of the front surface so that the transparent electrode is exposed. That is, the cutting is performed along the dotted line of Fig. 2.

[0070] At this time, by half-cutting one side of the front surface, it is configured as shown in Fig. 3. The half-cutting involves cutting only the top plate and the transparent electrode of the top plate so that the transparent electrode of the bottom plate is exposed. As a result, silver paste is applied to the upper side of the exposed transparent electrode of the bottom plate and an external electrode is attached.

[0071] As a result, since one side of the transparent electrode is cut by laser processing in the transparent electrode separation steps (S120, S220) of the upper and lower plates to become an inactive area, and referring again to FIG. 3, even if the transparent electrodes of the upper and lower plates are partially exposed on the rear and front sides respectively, the source of contact can be blocked due to the inactive area, thereby preventing a short circuit.

[0072] At this time, laser processing for forming the inactive region may use a dry laser or a laser for wet etching.

[0073] However, even if one side of the transparent electrode is deactivated, conduction between the upper plate and the lower plate is possible due to the active area between the two transparent electrodes formed by the liquid crystal and the spacer.

[0075] If an inactive region is not formed as in the present invention, the possibility of a short circuit increases due to a transparent electrode partially exposed on the front or rear side, as shown in Fig. 4 of the attached drawings.

[0077] In a smart window film manufactured by the manufacturing method described above, an alignment layer may be included, as in a conventional smart window film.

[0078] At this time, polarizing plates may be further attached to the upper and lower plates, which are plastic substrates. In this case, a polarizing plate with a polarization axis aligned at 90° is used, and the alignment layer is a horizontal alignment layer in which the liquid crystal is aligned in the same direction as the polarization axis of the polarizing plate. Additionally, the alignment layer is disposed on the transparent electrode surface, and a liquid crystal layer including a liquid crystal and a spacer may be formed between the alignment layers. In this case, the liquid crystal of the liquid crystal layer has a positive value of Δε and includes a chiral dopant.

[0080] In addition, as an example, an analyzer can be used instead of a polarizer.

[0082] In addition, when configuring the alignment layer, the orientation direction of the alignment layer may be oriented at 45° with respect to the polarization axis of the polarizer.

[0083] In addition, the alignment layer may be a vertical alignment layer, and in this case, the Pre-tilt angle may be 98 to 99° in the direction of the polarization axis of the polarizer. In this case, the liquid crystal of the liquid crystal layer described above may have a negative value of Δε.

[0084] In addition, the aforementioned alignment layer may be omitted if the transparent electrode is a PEDOT-PSS electrode instead of ITO.

[0086] According to the method for manufacturing a smart window film for preventing side short according to the present invention as described above, and the smart window film manufactured by said method,

[0087] During the manufacturing process, one side of the transparent electrode is processed into a laser-deactivated area to prevent short circuits by blocking the transparent electrode at the source, while allowing conduction to the transparent electrode between the top and bottom plates through lamination in the intersecting direction of the top and bottom plates, thereby enabling it to perform its function.

[0089] The description above using the drawings describes only the main aspects of the present invention, and it is obvious that the present invention is not limited to the configuration of the drawings, as various designs are possible within the technical scope. Explanation of the symbols

[0091] S100: Top plate processing step S110: Top plate preparation stage S120: Transparent electrode separation step S130: Spacer dispersion step S200: Bottom plate processing step S210: Bottom plate preparation stage S220: Transparent electrode separation step S230: Sealant bonding step S240: Liquid crystal coating step S300: Top and bottom plate lamination stage S400: Cutting stage

Claims

Claim 1 The method comprises: a top plate processing step (S100) for processing the top plate; a bottom plate processing step (S200) for processing the bottom plate; a top plate and bottom plate lamination step (S300) for laminating the top plate processed in the top plate processing step (S100) and the bottom plate processed in the bottom plate processing step (S200); and a cutting step (S400) for performing cutting along a predetermined line, such as the outer line of a sealant, after the top plate and bottom plate lamination step (S300); wherein the top plate processing step (S100) comprises the process of preparing the top plate (S110), separating one side of the transparent electrode on the prepared top plate so as to deactivate it (S120), and then spreading a spacer on one surface of the top plate (S130); and the bottom plate processing step (S200) comprises the process of preparing the bottom plate (S210), separating one side of the transparent electrode on the prepared bottom plate so as to deactivate it (S220), and then the bottom plate A method for manufacturing a smart window film for preventing side short circuits, comprising the steps of bonding a sealant to one surface (S230) and applying a liquid crystal coating (S240) into the seal line formed by the sealant, wherein deactivating one side of a transparent electrode is achieved by cutting one side of the transparent electrode through laser processing to form a deactivated area, and wherein the deactivated area is formed to overlap with the seal line or be located inside the seal line when the upper plate and the lower plate are laminated. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 A smart window film manufactured by the method for manufacturing a smart window film to prevent side shorts as described in claim 1. Claim 7 A smart window film according to claim 6, wherein the smart window film further comprises a polarizing plate formed on each of the upper plate and the lower plate, and the transparent electrode is a PEDOT-PSS electrode. Claim 8 A smart window film according to claim 6, wherein the smart window film further comprises a polarizing plate and an alignment layer formed on each of the upper plate and the lower plate, wherein the polarizing plate is positioned with a polarization axis of 90° and the alignment layer is a horizontal alignment layer oriented in the same direction as the polarization axis of the polarizing plate. Claim 9 A smart window film according to claim 6, wherein a polarizing plate and an alignment layer are further formed on each of the upper plate and the lower plate, wherein the polarizing plate is positioned with a polarization axis of 90° and the alignment direction of the alignment layer is oriented at 45° with respect to the polarization axis of the polarizing plate. Claim 10 A smart window film according to claim 6, wherein a polarizing plate and an alignment layer are further formed on each of the upper plate and the lower plate, wherein the polarizing plate is positioned with a polarization axis of 90° and the alignment layer is a vertical alignment layer with a pre-tilt angle of 98 to 99° in the direction of the polarization axis of the polarizing plate.

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