Sealed dimming element with surface protection film

Abstract

The present invention provides a PDLC element, which is a sealed PDLC (Polymer Dispersed Liquid Crystal) element with a surface protection film having a sealing layer on the end surface, and the surface protection film can be peeled off without residual sealing layer on the end surface of the PDLC element. The sealed dimming element with a surface protection film of the present invention comprises: a dimming element, the dimming element comprising a first transparent conductive film, a second transparent conductive film arranged in a manner facing the first transparent conductive film, and a polymer dispersed liquid crystal layer arranged between the first transparent conductive film and the second transparent conductive film; a surface protection film, the surface protection film comprising a substrate and an adhesive layer provided on one side of the substrate, and laminated on at least one main surface of the dimming element via the adhesive layer; and a sealing layer, the sealing layer being provided on the end surfaces of the dimming element and the surface protection film, when the thickness of the sealing layer is a (μm), the thickness of the substrate of the surface protection film is b (μm), and the thickness of the dimming element is c (μm), the relationship (1) to (3) is fully satisfied, a<0.3c(1), 10 <b<150(2)、a<0.4b(3)。

Description

Technical Field

[0001] The invention relates to a sealed dimming element with a surface protection film. Background Art

[0002] In a dimming element (hereinafter also referred to as a PDLC element) having a pair of transparent conductive films and a polymer dispersed liquid crystal layer arranged between the pair of transparent conductive films, a sealing structure is provided on the end face in order to prevent liquid crystal leakage, improve durability, etc. (for example, Patent Document 1 and Patent Document 2).

[0003] In the manufacture of PDLC elements, a large-area long strip PDLC element produced by a roll-to-roll process is often cut into a desired size. In this case, the end faces need to be sealed after cutting into the desired size.

[0004] In addition, in order to prevent damage or contamination, PDLC elements are shipped with a surface protection film on their surface. Users can use them after peeling off the surface protection film. At this time, in the roll-to-roll process, the long strip of surface protection film is attached to the surface of the long strip of PDLC element, cut into the required size, and then sealed, so a sealing structure is also formed on the end face of the surface protection film.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2002-6342

[0008] Patent Document 2: Japanese Patent Application Publication No. 2017-97221 Summary of the invention

[0009] Technical problem to be solved by the invention

[0010] The present inventors found that: Figure 5 As shown, regarding the sealed PDLC element 200 with a surface protection film having a sealing layer on the end face, when the surface protection film 20 is peeled off from the PDLC element 10, the following problem occurs: the residue of the sealing layer 30 existing on the end face of the surface protection film 20 remains on the surface of the PDLC element 10 in the form of burrs or debris.

[0011] The present invention is completed to solve the above-mentioned problems, and its main purpose is to provide a PDLC element, which is a sealed PDLC element with a surface protection film having a sealing layer on the end surface, and the surface protection film can be peeled off without leaving any residue of the sealing layer on the end surface of the PDLC element.

[0012] Means for solving technical problems

[0013] The inventors of the present invention have repeatedly tried and failed to solve the above problems. As a result, they found that no sufficient effect was found in the study of the composition of the resin used in the sealing material. In addition, by reducing the thickness of the substrate or adhesive layer of the surface protection film, burrs and debris cannot be greatly prevented. On the other hand, the problem of bulging of the surface protection film will also occur. Therefore, the inventors of the present invention have conducted further research and found that by designing the thickness of the sealing layer, the thickness of the substrate of the surface protection film, and the thickness of the PDLC element to satisfy a specific relationship, the generation of burrs and debris can be well suppressed when the surface protection film is peeled off from the PDLC element, and further the peeling of the sealing layer from the end face of the PDLC element can be prevented ( Figure 5 "breaking the seal"), thereby completing the present invention.

[0014] That is, according to one aspect of the present invention, there is provided a sealed dimming element with a surface protection film, comprising: a dimming element having a first transparent conductive film, a second transparent conductive film arranged in a manner opposite to the first transparent conductive film, and a polymer dispersed liquid crystal layer arranged between the first transparent conductive film and the second transparent conductive film; a surface protection film having a substrate and an adhesive layer provided on one side of the substrate, and laminated on at least one main surface of the dimming element via the adhesive layer; and a sealing layer provided on the end faces of the dimming element and the surface protection film, wherein when the thickness of the sealing layer is set to a (μm), the thickness of the substrate of the surface protection film is set to b (μm), and the thickness of the dimming element is set to c (μm), the relations (1) to (3) are fully satisfied.

[0015] a<0.3c (1)

[0016] 10 <b<150 (2)

[0017] a<0.4b (3)

[0018] In one embodiment, the first transparent conductive film and the second transparent conductive film each include a transparent substrate and a transparent electrode layer provided on one side of the transparent substrate.

[0019] In one embodiment, the sealing layer includes a resin having a breaking elongation of 5% to 30% when formed into a film having a thickness of 50 μm.

[0020] In one embodiment, a part of the end surface of the sealed dimming element with a surface protection film is an exposed portion where no sealing layer is provided.

[0021] According to one aspect of the present invention, there is provided a stacked body including two or more of the sealed dimming elements with surface protection films, wherein the sealing layer is integrally formed on an end surface of the stacked body.

[0022] Effects of the Invention

[0023] The present invention has found that by optimizing the thickness of the sealing layer, the thickness of the substrate of the surface protection film, and the thickness of the dimming element, the sealing layer undergoes cohesive fracture when the surface protection film is peeled off, and no residue of the sealing layer remains. Thus, according to the present invention, a sealed PDLC element with a surface protection film can be provided, which can peel off the surface protection film without leaving residue of the sealing layer on the end face of the PDLC element. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 (a) is a schematic cross-sectional view of a sealed PDLC element with a surface protection film according to one embodiment of the present invention, Figure 1 (b) Figure 1 (a) is a schematic top view of a sealed PDLC element with a surface protection film.

[0025] Figure 2 It is a schematic plan view of an example of a sealed PDLC element with a surface protection film having an exposed portion.

[0026] Figure 3 This is a schematic diagram for explaining a method for manufacturing a sealed PDLC element with a surface protection film according to one embodiment.

[0027] Figure 4 It is a graph showing the relationship between the peeling state and various parameters when the surface protection film is peeled off in the sealed PDLC element with the surface protection film of the Example and the Comparative Example.

[0028] Figure 5 This is a schematic diagram for explaining the problems that may occur when the surface protection film of a sealed PDLC element with its own surface protection film is peeled off. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

[0030] A. Sealed PDLC element with surface protection film

[0031] A-1. Overall structure of sealed PDLC element with surface protection film

[0032] Figure 1 (a) is a schematic cross-sectional view of a sealed PDLC element with a surface protection film according to one embodiment of the present invention, Figure 1 (b) Figure 1(a) is a schematic top view of a sealed PDLC element with a surface protection film. The sealed PDLC element 100a with a surface protection film comprises: a PDLC element 10, which comprises a first transparent conductive film 11, a second transparent conductive film 12 arranged in a manner facing the first transparent conductive film 11, and a polymer dispersed liquid crystal layer 13 arranged between the first transparent conductive film 11 and the second transparent conductive film 12; surface protection films 20a, 20b, which comprise a substrate 21 and an adhesive layer 22 arranged on one side of the substrate 21, and are laminated (bonded) to both main surfaces of the PDLC element 10 via the adhesive layer 22; and a sealing layer 30, which is arranged on the entire end surfaces of the PDLC element 10 and the surface protection films 20a, 20b.

[0033] exist Figure 1 In the sealed PDLC element 100a with a surface protection film shown, either of the surface protection films 20a and 20b can be omitted according to the purpose. In addition, although not shown, an antifouling film can be further provided on the outermost surface of the sealed PDLC element 100a with a surface protection film to prevent contamination and damage before shipment, for example. In this case, the sealing layer can be provided in a manner that also covers the end surface of the antifouling film.

[0034] In the sealed PDLC element 100a with a surface protection film, the thickness of the sealing layer 30 is ( Figure 1 When (b), represented by the symbol "t") is set to a (μm), the thickness of the substrate 21 of the surface protection films 20a and 20b is set to b (μm), and the thickness of the PDLC element 10 is set to c (μm), a, b and c completely satisfy the relationships (1) to (3) (wherein, when the substrate thickness of the surface protection film 20a is different from the substrate thickness of the surface protection film 20b, the thickness of each substrate completely satisfies the relationships (1) to (3)).

[0035] a<0.3c (1)

[0036] 10 <b<150 (2)

[0037] a<0.4b (3)

[0038] When the thickness of the sealing layer 30 (a: μm), the thickness of the substrate 21 of the surface protection films 20a and 20b (b: μm), and the thickness of the PDLC element 10 (c: μm) satisfy all of the above-mentioned relational expressions (1) to (3), the breaking force of the sealing layer is appropriately reduced due to the thinning of the sealing layer and the thickening of the substrate of the surface protection film, and the adhesion between the sealing layer and the surface protection film can be appropriately increased. As a result, the surface protection film can be peeled off from the PDLC element without leaving the sealing layer on the surface of the PDLC element in the form of burrs or debris, and without causing the problem of breaking the seal.

[0039] The thickness of the sealing layer 30 (a: μm), the thickness of the substrate 21 of the surface protection films 20a and 20b (b: μm), and the thickness of the PDLC element 10 (c: μm) are preferably any one of the relationships (1') to (3'), more preferably any two of them, and further preferably completely satisfy the relationship (when the substrate thickness of the surface protection film 20a is different from the substrate thickness of the surface protection film 20b, the thickness of each substrate is preferably any one of the relationships (1') to (3'), more preferably any two of them, and further preferably completely satisfy the relationship).

[0040] a≤0.2c (1')

[0041] 30≤b≤130 (2')

[0042] a≤0.3b (3')

[0043] In one embodiment, a portion of the end surface of the sealed PDLC element with a surface protection film may be an exposed portion without a sealing layer. Since the exposed portion can function as a peeling starting point, the workability when peeling the surface protection film from the PDLC element can be improved.

[0044] Figure 2 1 is a schematic top view of an example of a sealed PDLC element with a surface protection film having an exposed portion. The sealed PDLC element 100b with a surface protection film has a rectangular PDLC element body (a main body portion that functions as a PDLC element) 110 in a top view, and lead-out electrode portions 112 and 114 for applying a driving voltage to the PDLC element body 110, and a sealing layer 30 is provided on the peripheral end surface other than the lead-out electrode portions 112 and 114. In the example shown in the figure, the lead-out electrode portion 112 can be formed by extending a portion of the first transparent conductive film constituting the PDLC element body 110 outward from the body 110, and the lead-out electrode portion 114 can be formed by extending a portion of the second transparent conductive film constituting the PDLC element body 110 outward from the body 110. In addition, unlike the example shown in the figure, the exposed portion can be provided at any appropriate position other than the lead-out electrode portion. For example, the end surface of one or more corners of the sealed PDLC element with a surface protection film formed in a rectangular shape in a top view can be set as an exposed portion.

[0045] A-2.PDLC components

[0046] The PDLC element includes: a first transparent conductive film; a second transparent conductive film disposed so as to face the first transparent conductive film; and a polymer dispersed liquid crystal layer disposed between the first transparent conductive film and the second transparent conductive film.

[0047] As described in item A-2-3 below, the diffusion degree of light of the PDLC element (resulting in haze) varies according to the applied voltage. In one embodiment, the situation where the haze of the PDLC element is above a specific value (e.g., above 30%, more preferably above 50%) is set as a scattering state, and the situation where the haze is below a specified value (e.g., below 30%, preferably below 15%, more preferably below 10%) is set as a transparent state. In order to control the diffusion degree of light, the voltage (driving voltage) applied to the PDLC element is, for example, below 100V, more preferably below 50V.

[0048] The thickness of the PDLC element is set to a range satisfying the above formula (1). The thickness of the PDLC element is, for example, 30 μm to 250 μm, and more preferably 50 μm to 200 μm.

[0049] A-2-1. First transparent conductive film

[0050] Typically, the first transparent conductive film comprises a first transparent substrate and a first transparent electrode layer provided on one side of the first transparent substrate, and the first transparent electrode layer is arranged so as to become the polymer dispersed liquid crystal layer side. Depending on the purpose, the first transparent conductive film may further comprise any appropriate functional layer (refractive index adjustment layer, anti-reflection layer, hard coating layer, etc.).

[0051] The surface resistance value of the first transparent conductive film is more preferably 0.1 Ω / sq to 1000 Ω / sq, more preferably 0.5 Ω / sq to 300 Ω / sq, and further preferably 1 Ω / sq to 200 Ω / sq.

[0052] The haze value of the first transparent conductive film is more preferably 20% or less, more preferably 10% or less, and further preferably 0.1% to 10%.

[0053] The total light transmittance of the first transparent conductive film is preferably 30% or more, more preferably 60% or more, and even more preferably 80% or more.

[0054] The first transparent electrode layer can be formed using metal oxides such as indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO2), etc. In this case, the metal oxide can be an amorphous metal oxide or a crystallized metal oxide. Alternatively, the first transparent electrode layer can be formed by metal nanowires such as silver nanowires (AgNW), carbon nanotubes (CNTs), organic conductive films, metal layers, or laminates thereof. The first transparent electrode layer can be patterned into a desired shape according to the purpose.

[0055] The thickness of the first transparent electrode layer is preferably 0.01 μm to 0.10 μm, and more preferably 0.01 μm to 0.045 μm.

[0056] Typically, the first transparent electrode layer can be provided on one surface of the first transparent substrate by using a method such as sputtering.

[0057] The first transparent substrate is formed of any appropriate material. Specifically, a glass substrate or a polymer substrate is preferably used, and a polymer substrate is more preferably used.

[0058] Typically, the polymer substrate is a polymer film having a thermoplastic resin as a main component. Examples of the thermoplastic resin include cycloolefin resins such as polynorbornene, acrylic resins, polyester resins such as polyethylene terephthalate resins, polycarbonate resins, and cellulose resins. Among them, cycloolefin resins or polyethylene terephthalate resins can be preferably used. The thermoplastic resins can be used alone or in combination of two or more.

[0059] The thickness of the first transparent substrate is preferably 10 μm to 100 μm, more preferably 20 μm to 80 μm.

[0060] A-2-2. Second transparent conductive film

[0061] Typically, the second transparent conductive film comprises a second transparent substrate and a second transparent electrode layer provided on one side of the second transparent substrate, and the second transparent electrode layer is arranged so as to become the polymer dispersed liquid crystal layer side. Depending on the purpose, the second transparent conductive film may further have any appropriate functional layer (refractive index adjustment layer, anti-reflection layer, hard coating layer, etc.).

[0062] The surface resistance value of the second transparent conductive film is preferably 0.1 Ω / sq to 1000 Ω / sq, more preferably 0.5 Ω / sq to 300 Ω / sq, and further preferably 1 Ω / sq to 200 Ω / sq.

[0063] The haze value of the second transparent conductive film is preferably 20% or less, more preferably 10% or less, and further preferably 0.1% to 10%.

[0064] The total light transmittance of the second transparent conductive film is preferably 30% or more, more preferably 60% or more, and even more preferably 80% or more.

[0065] The same description as that of the first transparent electrode layer and the first transparent substrate can be applied to the second transparent electrode layer and the second transparent substrate, respectively. The first transparent conductive film and the second transparent conductive film may have the same structure or different structures.

[0066] A-2-3. Polymer-dispersed liquid crystal layer

[0067] Typically, a polymer dispersed liquid crystal (PDLC) layer has a structure in which a liquid crystal compound is dispersed in a resin matrix. In the PDLC layer, the scattering degree of transmitted light changes by changing the orientation degree of the liquid crystal compound corresponding to the applied voltage, thereby switching between a transparent state and a scattering state.

[0068] In one embodiment, the PDLC layer becomes transparent by applying a voltage, and becomes a scattering state (normal mode) when no voltage is applied. In this embodiment, when no voltage is applied, the liquid crystal compound is not oriented and thus becomes a scattering state, and by applying a voltage, the liquid crystal compound is oriented, and the refractive index of the liquid crystal compound is consistent with the refractive index of the resin matrix, resulting in a transparent state.

[0069] In other embodiments, the PDLC layer is changed into a scattering state by applying a voltage, and becomes a transparent state (reverse mode) when no voltage is applied. In this embodiment, when no voltage is applied, the liquid crystal compound is oriented by the orientation film provided on the surface of the transparent electrode layer, and becomes a transparent state, and the orientation of the liquid crystal compound is disrupted by the application of voltage, and becomes a scattering state.

[0070] As the above-mentioned liquid crystal compound, any appropriate non-polymeric liquid crystal compound is used. For example, nematic, smectic, and cholesterol liquid crystal compounds can be listed. From the viewpoint of achieving excellent transparency in the transmission mode, nematic liquid crystal compounds are more preferably used. As the above-mentioned nematic liquid crystal compound, biphenyl compounds, phenyl benzoate compounds, cyclohexylbenzene compounds, azoxybenzene compounds, azobenzene compounds, azomethine compounds, terphenyl compounds, bibenzoate compounds, cyclohexylbiphenyl compounds, phenylpyridine compounds, cyclohexylpyrimidine compounds, cholesterol compounds, etc. can be listed.

[0071] The content of the liquid crystal compound in the PDLC layer is, for example, 10 wt % or more, preferably 30 wt % or more, more preferably 35 wt % or more, and further preferably 40 wt % or more. The content is, for example, 90 wt % or less, and preferably 70 wt % or less.

[0072] The resin forming the resin matrix can be appropriately selected according to light transmittance, the refractive index of the liquid crystal compound, the adhesion with the transparent conductive film, etc. For example, water-soluble resins or water-dispersible resins such as urethane resins, polyvinyl alcohol resins, polyethylene resins, polypropylene resins, acrylic resins, and liquid crystal polymers, (meth) acrylic resins, silicone resins, epoxy resins, fluorine resins, polyester resins, polyimide resins, and other curable resins can be listed.

[0073] The content of the matrix-forming resin in the PDLC layer is, for example, 90 wt % or less, preferably 70 wt % or less, more preferably 65 wt % or less, and further preferably 60 wt % or less. In addition, the content is, for example, 10 wt % or more, preferably 30 wt % or more.

[0074] The thickness of the PDLC layer is, for example, 50 μm or less, preferably 30 μm or less, more preferably 20 μm or less, and further preferably 15 μm or less. The lower limit of the thickness of the PDLC layer can be set to, for example, 5 μm.

[0075] The PDLC layer can be produced by any appropriate method, and specific examples thereof include emulsion-based and phase-separation-based production methods.

[0076] The method for preparing the PDLC layer of the emulsion method includes, for example, applying an emulsion coating liquid containing a matrix-forming resin and a liquid crystal compound on a transparent electrode layer of a transparent conductive film to form a coating layer; and drying the coating layer to form a resin matrix with the matrix-forming resin. The emulsion coating liquid is preferably a mixed liquid containing a matrix-forming resin and a coating solvent in a continuous phase, and an emulsion containing a liquid crystal compound in a dispersed phase. By applying the emulsified coating liquid and drying it, a PDLC layer having a structure in which the liquid crystal compound is dispersed in a resin matrix can be formed. Typically, a PDLC element can be obtained by stacking other transparent conductive films on the PDLC layer.

[0077] The method for preparing a PDLC layer of a phase separation method includes, for example, applying a coating liquid containing a radiation-curable matrix-forming resin and a liquid crystal compound on a transparent electrode layer of a transparent conductive film to form a coating layer; stacking another transparent conductive film on the coating layer to form a laminate; and polymerizing the matrix-forming resin by irradiating the laminate with radiation, thereby separating the resin matrix and the liquid crystal compound; thereby, a PDLC element can be obtained. The coating is more preferably in a uniform phase state. As an alternative, the coating liquid can be filled between the first transparent conductive film and the second transparent conductive film stacked with a spacer, and then phase separation can be performed by irradiation with radiation.

[0078] A-3. Surface protection film

[0079] The surface protection film comprises a substrate and an adhesive layer disposed on one side of the substrate. The surface protection film is disposed to prevent the surface of the PDLC element from being damaged or contaminated, and is usually peeled off and removed before using the PDLC element. In addition, when the surface protection film is disposed on both surfaces of the PDLC element, the surface protection films of the same composition may be used, or the surface protection films of different compositions may be used.

[0080] The thickness of the surface protection film is, for example, 15 μm to 200 μm, or preferably 30 μm to 150 μm.

[0081] Examples of the material for forming the substrate include ester resins such as polyethylene terephthalate resins, cycloolefin resins such as norbornene resins, olefin resins such as polypropylene, polyamide resins, polycarbonate resins, and copolymer resins thereof. Preferably, the resin is an ester resin (particularly polyethylene terephthalate resin).

[0082] The thickness of the substrate is set to satisfy the range of the above formulas (2) and (3). The thickness of the substrate is, for example, more than 10 μm and less than 150 μm, preferably 30 μm to 130 μm, and more preferably 30 μm to 100 μm. When the substrate thickness of the surface protection film is within the above range, problems such as breaking of the seal can be prevented, and the surface protection film can be more preferably peeled off from the PDLC element.

[0083] The adhesive layer is formed by any appropriate adhesive composition. Specific examples of the adhesive composition include adhesive compositions based on (meth) acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluorine polymers, rubber polymers, etc. Among them, from the perspectives of transparency, weather resistance, heat resistance, etc., an acrylic adhesive composition based on an acrylic polymer is more preferred.

[0084] The thickness of the adhesive layer is, for example, 3 μm to 100 μm, more preferably 4 μm to 80 μm, and even more preferably 5 μm to 60 μm.

[0085] A-4. Sealing layer

[0086] The sealing layer is arranged on the end face of the PDLC element and the surface protection film to prevent the leakage of the liquid crystal compound, improve the durability, etc. In one embodiment, an organic material can be used as a material for forming the sealing layer. As a specific example of an organic material, a curing resin such as a UV (Ultraviolet) curing resin (e.g., a UV curing acrylic resin), a thermosetting resin (e.g., a thermosetting polyurethane resin, an acrylic resin, a polyurethane acrylic resin, and a mixture thereof) can be cited. As a curing resin, a curing resin the same as the resin matrix forming resin of the PDLC layer can be used. In addition, an organic material that can be formed into a film by evaporation (including evaporation polymerization) can also be used. As such an organic material, for example, a dimer (di-p-xylene) that can form a parylene film by evaporation polymerization, a monomer (diol and diisocyanate) that can form a polyurethane film, a monomer (diamine and anhydride) that can form a polyimide film, a monomer (diamine and diisocyanate) that can form a polyurea film, etc. can be cited. When using an evaporation film, a high-density sealing layer can be obtained. In other embodiments, inorganic materials can be used as the forming material of the sealing layer. Specific examples of inorganic materials include oxides, nitrides, carbides, oxynitrides, oxycarbons, carbonitrides, oxycarbonitrides, etc. of metals such as zinc, aluminum, titanium, copper, and magnesium, or semimetals such as silicon, bismuth, and germanium. In addition, the sealing layer can be formed using a resin containing inorganic materials such as inorganic microparticles, or can also include a laminated structure of a resin layer and an inorganic layer.

[0087] Typically, the sealing layer is formed by applying a sealing layer forming material (e.g., a composition containing the above-mentioned curable resin and / or inorganic material) to the end surface of the PDLC element with a surface protection film and curing the material. Examples of the coating method include spraying, dispenser coating, brush coating, screen printing, dipping, and vapor deposition.

[0088] The resin composition containing the above-mentioned curable resin may contain a polymerization initiator (e.g., "Irgacure TPO" manufactured by BASF) as needed. In addition, from the viewpoint of improving adhesion, a silane coupling agent (e.g., "KBM903" manufactured by Shin-Etsu Silicone Co., Ltd.) or a close-fitting auxiliary agent (e.g., "KAYAMER (registered trademark) PM-2" manufactured by Nippon Kayaku Co., Ltd.) may be used.

[0089] The thickness of the sealing layer is set to satisfy the range of the above formulas (1) and (3). The thickness of the sealing layer formed by an organic material is, for example, 2 μm to 50 μm, preferably 3 μm to 40 μm, and more preferably 4 μm to 30 μm. Among them, when the sealing layer is an organic vapor-deposited film, its thickness is preferably 0.05 μm to 5 μm, and more preferably 0.2 μm to 1 μm. In addition, the thickness of the sealing layer formed by an inorganic material is, for example, 0.1 μm to 5 μm, preferably 0.2 μm to 3 μm, and more preferably 0.2 μm to 2 μm.

[0090] The elongation at break of the material forming the sealing layer (the elongation at break of the film obtained by forming the material forming the sealing layer into a film with a thickness of 50 μm) is not particularly limited as long as the effect of the present invention can be obtained. The lower limit is usually 1% or more, and on the other hand, the upper limit is usually 30% or less. From the viewpoint of flexibility, the upper limit of the elongation at break is preferably 20% or less, and more preferably 10% or less. On the other hand, the lower limit of the elongation at break is preferably 5% or more. In the present invention, the elongation at break of the material forming the sealing layer is measured by the following procedure.

[0091] When the material forming the sealing layer is a water-soluble resin, an aqueous solution of the resin composition forming the sealing layer is prepared, coated on a polyester film subjected to a demolding treatment, left to stand at room temperature for 1 hour, and dried at 70°C for 3 hours to produce a resin film with a thickness of 50 μm. A sample of a film with a width of 10 mm and a length of 50 mm is cut out from the resin film. A tensile test is performed using an automatic stereogrammer AGS-X (manufactured by Shimadzu Corporation) with a chuck interval of 30 mm and a tensile speed of 200 mm / min to measure the elongation at break.

[0092] When the material forming the sealing layer is a fat-soluble resin, a solution of the resin composition is prepared using any organic solvent, and a resin film is manufactured in the same manner as described above. When the material forming the sealing layer is an energy active line curing resin such as an ultraviolet curing resin, a solution of any energy active line curing resin is prepared, applied to a polyester film, and irradiated with energy active lines such as ultraviolet rays to manufacture a resin film. Alternatively, a film having a thickness of 50 μm can be formed by any other method such as evaporation. For these films, the elongation at break can be measured in the same manner as described above.

[0093] B. Manufacturing Method

[0094] The sealed PDLC element with a surface protection film described in item A can be manufactured using any appropriate manufacturing method. The manufacturing method of the above-mentioned sealed PDLC element with a surface protection film in one embodiment includes: laminating a long strip of surface protection film to one or both surfaces of a PDLC element made into a long strip in a roll-to-roll form to obtain a long strip of PDLC element with a surface protection film; cutting the long strip of PDLC element with a surface protection film into a desired shape to obtain a monolithic PDLC element with a surface protection film; and forming a sealing layer on the entire end face of the monolithic PDLC element with a surface protection film or except for a part (exposed part). It is also possible to perform surface treatment on the end face of the PDLC element with a surface protection film before forming the sealing layer as needed. By performing surface treatment, the surface tension of the treated surface can be reduced, and tiny foreign matter (such as organic matter) can be removed to smooth the treated surface. As a result, the adhesion strength between the end face of the PDLC element and the sealing layer can be improved. As such surface treatment, coating with an easy-to-adhesive material, UV ozone treatment, plasma treatment, etc. can be listed.

[0095] The formation of the sealing layer can be performed individually on the PDLC element with a surface protection film cut into a desired shape, or can be performed uniformly on a stack of multiple PDLC elements with a surface protection film. By uniformly forming the sealing layer on the stack of multiple PDLC elements with a surface protection film, the sealing process efficiency can be significantly improved, and as a result, a sealed PDLC element with a surface protection film can be obtained with high manufacturing efficiency.

[0096] Figure 3 This is a schematic diagram for explaining an example of a production method in which a sealing layer is formed collectively on a laminate of PDLC elements with a surface protection film. Figure 3The manufacturing method shown includes: laminating the long strip surface protection films 20a and 20b to both surfaces of the PDLC element 10 made into a long strip in a roll-to-roll manner to obtain the long strip PDLC element 50 with a surface protection film (lamination); cutting the long strip PDLC element 50 with a surface protection film into a desired shape to obtain a single-piece PDLC element 50a with a surface protection film (punching); stacking a plurality of single-piece PDLC elements 50a with a surface protection film to obtain a stack 50b (stack manufacturing); integrally forming a sealing layer 60 on the end surface of the stack 50b (sealing treatment); and separating the stack 50c formed with the sealing layer into individual sealed PDLC elements 100 with a surface protection film (single chip). Although not shown in the figure, after laminating the long strip antifouling film to one or both surfaces of the long strip PDLC element 50 with a surface protection film in a roll-to-roll manner, the processing after punching can also be performed. In the example shown in the figure, the sealing layer 60 is formed on the entire end surface of the stack 50b, but unlike the example shown in the figure, a part of the end surface of the stack 50b (for example, the end surface of the lead electrode portion) may be set as an exposed portion without forming a sealing layer thereon.

[0097] As a method for separating the stack 50c into individual sealed PDLC elements 100 with surface protection films, for example, there can be listed: inserting a peeling tool such as a scraper between adjacent sealed PDLC elements with surface protection films for separation; peeling and separating the sealed PDLC element with a surface protection film from the adjacent element starting from the exposed portion, the above-mentioned stack 50c is a stack formed by stacking more than two sealed dimming elements with surface protection films, and a sealing layer is integrally formed on the end face of the stack (in other words, the sealing layer is continuously formed in the stacking direction of the stack).

[0098] The number of the single-piece PDLC elements 50a with a surface protection film included in the stacked body 50b is not limited as long as the effects of the present invention can be obtained, but is preferably 3 or more, more preferably 10 to 20, and even more preferably 50 to 100.

[0099] The sealing layer can be formed on the laminate 50b by, for example, performing any surface treatment on the entire end surface of the laminate 50b or the portion other than the exposed portion, and then applying the material for forming the sealing layer (for example, the curable resin and / or a composition containing an inorganic material or an organic material) and curing it as needed. As the coating method, the coating methods exemplified in item A-4 can be cited, among which spray coating or vapor deposition is more preferred.

[0100] [Example]

[0101] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In addition, "parts" and "%" in examples and comparative examples are by weight unless otherwise specified.

[0102] [Example 1]

[0103] (Manufacturing PDLC components)

[0104] On one surface of a transparent substrate (norbornene-based resin film (manufactured by Zeon Japan, product name "ZF-16"), thickness: 40 μm), a transparent electrode layer (ITO layer) with a thickness of 0.08 μm was formed by sputtering, and then annealed at 150°C for crystallization. In this way, the first and second transparent conductive films having the structure of [COP substrate / transparent electrode layer] were obtained.

[0105] On the transparent electrode layer side surface of the first transparent conductive film, a coating liquid containing 40 parts of a liquid crystal compound (manufactured by HCCH, product name "HPC854600-100", birefringence Δn = 0.232) and 60 parts of a UV curable resin (manufactured by Norland, product name "NOA65") (solid content) was applied to form a coating layer. Next, on the coating layer, a second transparent conductive film was stacked in a manner such that the transparent electrode layer and the coating layer faced each other. The obtained stack was irradiated with ultraviolet rays to cure the UV curable resin, thereby forming a PDLC layer having a thickness of 20 μm. A PDLC element (thickness 100 μm) was obtained in the above manner.

[0106] (Manufacturing PDLC elements with surface protection films)

[0107] A surface protection film (manufactured by Nitto Denko Corporation, product name "RP207") having a PET resin substrate (38 μm) and an acrylic adhesive layer (21 μm) provided on one side thereof was bonded to both surfaces of the above-mentioned PDLC element to obtain a PDLC element with a surface protection film.

[0108] (Sealing treatment)

[0109] The resin composition for forming a sealing layer was applied to the entire end surface of the PDLC element with a surface protection film, and cured by heating and drying at 70° C. for 3 hours to form a sealing layer with a thickness of 10 μm. In addition, as a coating liquid of the resin composition for forming a sealing layer, an acrylic resin emulsion aqueous solution, a polyolefin resin, and an isocyanate curing agent were prepared and mixed in such a manner that the elongation at break of the formed film with a thickness of 50 μm was 10%.

[0110] In the above manner, a sealed PDLC element with a surface protection film was obtained.

[0111] [Examples 2 to 8, Comparative Examples 1 to 5]

[0112] A sealed PDLC element with a surface protection film was obtained in the same manner as in Example 1 except that the thickness of the substrate of the PDLC element, the sealing layer and / or the surface protection film was changed as shown in Table 1.

[0113] [Example 9]

[0114] (Manufacturing PDLC components)

[0115] In the same manner as in Example 1, a PDLC element (thickness: 100 μm) was obtained.

[0116] (Manufacturing PDLC elements with surface protection films)

[0117] A surface protection film having a PET-based resin substrate (30 μm) and an acrylic adhesive layer (10 μm) provided on one side thereof was bonded to both surfaces of the PDLC element to obtain a PDLC element with a surface protection film.

[0118] (Sealing treatment)

[0119] The entire end surface of the PDLC element with a surface protection film was plasma treated, and a 5 μm thick parylene coating layer (sealing layer) was formed on the plasma treated surface by vacuum deposition using a parylene material (manufactured by Kisco, product name "dixC").

[0120] [Comparative Example 6]

[0121] A sealed PDLC element with a surface protection film was obtained in the same manner as in Example 9 except that the thickness of the sealing layer was 15 μm.

[0122] [Table 1]

[0123]

[0124] In the sealed PDLC element with a surface protection film obtained in the above-mentioned embodiment and comparative example, a surface protection film was peeled off from the PDLC element using a peeling tool. The end of the peeled PDLC element was observed under a microscope to evaluate whether there was "burr" and "broken seal". The results are shown in Table 2 and Figure 4 .

[0125] [Table 2]

[0126]

[0127] As shown in Table 2 and Figure 4As shown, according to the sealed PDLC element with a surface protection film of the embodiment, the surface protection film can be preferably peeled off from the PDLC element without leaving residues of the sealing layer on the surface of the PDLC element.

[0128] Industrial Applicability

[0129] The sealed dimming element with a surface protection film of the present invention is preferably used in a display device having a dimming function, an optical member having a shutter function, and the like.

[0130] Explanation of symbols

[0131] 100 Sealed dimming element with surface protection film

[0132] 10 Dimming element

[0133] 11. No. 1 transparent conductive film

[0134] 12. Second transparent conductive film

[0135] 13 Polymer dispersed liquid crystal layer

[0136] 20 Surface protection film

[0137] 21. Substrate

[0138] 22 Adhesive layer

[0139] 30 Sealing layer

Claims

1. A sealed dimming element with a surface protection film, comprising: A light-adjusting element comprising a first transparent conductive film, a second transparent conductive film disposed so as to face the first transparent conductive film, and a polymer-dispersed liquid crystal layer disposed between the first transparent conductive film and the second transparent conductive film; a surface protection film including a substrate and an adhesive layer provided on one side of the substrate, and laminated on at least one main surface of the light-adjusting element via the adhesive layer; and A sealing layer, the sealing layer is arranged on the end surfaces of the dimming element and the surface protection film, When the thickness of the sealing layer is a, the thickness of the substrate of the surface protection film is b, and the thickness of the light-adjusting element is c, the relations (1) to (3) are fully satisfied. a<0.3c (1) 10<b<150 (2) a<0.4b (3) The unit of a, b, c is μm.

2. The sealed dimming element with a surface protection film according to claim 1, wherein: The first transparent conductive film and the second transparent conductive film each include a transparent substrate and a transparent electrode layer provided on one side of the transparent substrate.

3. The sealed dimming element with a surface protection film according to claim 1 or 2, wherein: The sealing layer includes a resin having a breaking elongation of 5% to 30% when formed into a film having a thickness of 50 μm.

4. The sealed dimming element with a surface protection film according to claim 1 or 2, wherein: A portion of the end surface is an exposed portion where no sealing layer is provided. 5 . A laminated body comprising two or more sealed dimming elements with a surface protection film according to claim 1 , wherein the sealing layer is integrally formed on an end surface of the laminated body.

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