WO2021065731A1

WO2021065731A1 - Sealed light control element with surface protection film

Info

Publication number: WO2021065731A1
Application number: PCT/JP2020/036326
Authority: WO
Inventors: 雅徳大塚; 晃宏澁谷; 平井　真理子; 武本　博之
Original assignee: 日東電工株式会社
Priority date: 2019-09-30
Filing date: 2020-09-25
Publication date: 2021-04-08
Also published as: CN114503024A; TW202121037A; KR20220074862A; JP2021056505A

Abstract

Provided is a sealed PDLC element with a surface protection film having a sealing layer on an end surface thereof, in which the surface protection film can be peeled off without a residue of the sealing layer remaining on the end surface of the PDLC element.　This sealed light control element with a surface protection film comprises: a light control element including a first transparent conductive film, a second transparent conductive film that is disposed so as to oppose the first transparent conductive film, and a polymer-dispersed liquid crystal layer that is 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 to one side of the substrate, the surface protection film being layered via the adhesive layer onto at least one of the primary surfaces of the light control element; and a sealing layer that is provided to an end surface of the light control element and the surface protection film. If the thickness of the sealing layer is a (μｍ), the substrate thickness of the surface protection film is b (μｍ), and the thickness of the light control element is c (μｍ), all of the following relationships (1) to (3) are satisfied.　a<0.3c (1) 10<b<150 (2) a<0.4b (3)

Description

Sealed dimming element with surface protective film

The present invention relates to a sealed dimming element with a surface protective film.

In a dimming element (hereinafter, also referred to as a PDLC element) including a pair of transparent conductive films and a polymer-dispersed liquid crystal layer arranged between them, the end face thereof is intended to prevent leakage of the liquid crystal and improve durability. A sealing structure may be provided (for example, Patent Document 1 and Patent Document 2).

In the manufacture of PDLC devices, large-area long PDLC devices manufactured by a roll-to-roll process are often cut to a desired size, and in this case, the end face is sealed after cutting to the desired size. Is required.

Further, the PDLC element is shipped with a surface protective film provided on its surface in order to prevent scratches and stains, and can be used after the surface protective film has been peeled off by the user. In this case, a long surface protective film is attached to the surface of the long PDLC element by a roll-to-roll process, and then the surface is cut to a desired size and then sealed. A sealing structure is also formed on the end face of the protective film.

JP-A-2002-6342 JP-A-2017-97221

As shown in FIG. 5, regarding the sealed PDLC element 200 with a surface protective film having a sealing layer on the end face, the present inventors of the surface protective film 20 when peeling the surface protective film 20 from the PDLC element 10. It has been found that the residue of the sealing layer 30 existing on the end face has a problem of remaining on the surface of the PDLC element 10 in the state of burrs and debris.

The present invention has been made to solve the above problems, and a main object thereof is a sealing PDLC element with a surface protective film having a sealing layer on the end face, and the residue of the sealing layer is a PDLC element. It is an object of the present invention to provide a PDLC element capable of peeling off a surface protective film without remaining on the surface.

As a result of repeated trial and error in order to solve the above problems, the present inventors did not find a sufficient effect in examining the composition of the resin or the like used for the encapsulant, and also found that the base material and the adhesiveness of the surface protective film were not sufficiently effective. It has been found that reducing the thickness of the agent layer does not greatly prevent burrs and debris, but causes a problem of floating of the surface protective film. Therefore, as a result of further studies by the present inventors, the surface protective film is made into PDLC by designing the thickness of the sealing layer, the thickness of the base material of the surface protective film, and the thickness of the PDLC element to satisfy a specific relationship. We have found that the generation of burrs and debris can be satisfactorily suppressed when peeling from the element, and that the sealing layer can be prevented from peeling from the end face of the PDLC element (“seal removal” in FIG. 5). The present invention has been completed.

That is, according to one aspect of the present invention, the first transparent conductive film, the second transparent conductive film arranged so as to face the first transparent conductive film, and the first transparent conductive film. A dimming element comprising a transparent conductive film and a polymer-dispersed liquid crystal layer disposed between the second transparent conductive film; provided on one side of the base material and the base material. A surface protective film provided with an adhesive layer and laminated on at least one main surface of the dimming element via the adhesive layer; a seal provided on the end face of the dimming element and the surface protective film. When the thickness of the sealing layer is a (μm), the thickness of the base material of the surface protective film is b (μm), and the thickness of the dimming element is c (μm). A sealed dimming element with a surface protective film that satisfies all of (1) to (3) is provided.
a <0.3c (1)
10 <b <150 (2)
a <0.4b (3)
In one embodiment, the first transparent conductive film and the second transparent conductive film each have a transparent base material and a transparent electrode layer provided on one side of the transparent base material. ..
In one embodiment, the sealing layer comprises a resin having a breaking elongation of 5% to 30% when molded into a film having a thickness of 50 μm.
In one embodiment, a part of the end face of the sealing dimming element with a surface protective film is an exposed portion not provided with a sealing layer.
According to one aspect of the present invention, it is a laminated body in which two or more sealing dimming elements with a surface protective film are laminated, and the sealing layer is integrally formed on the end face of the laminated body. The laminate is provided.

In the present invention, by optimizing the thickness of the sealing layer, the thickness of the base material of the surface protective film, and the thickness of the dimming element, the sealing layer coagulates and breaks when the surface protective film is peeled off, and the sealing layer is formed. A condition was found in which no residue remained. Therefore, according to the present invention, it is possible to provide a sealed PDLC element with a surface protective film capable of peeling off the surface protective film without leaving the residue of the sealing layer on the end face of the PDLC element.

FIG. 1A is a schematic cross-sectional view of a sealed PDLC element with a surface protective film according to one embodiment of the present invention, and FIG. 1B is a sealing with a surface protective film shown in FIG. 1A. It is a schematic top view of a PDLC element. It is a schematic top view of an example of a sealed PDLC element with a surface protective film having an exposed portion. It is the schematic explaining the manufacturing method of the sealing PDLC element with the surface protection film by one Embodiment. It is a figure which shows the relationship between the peeling state and each parameter at the time of peeling the surface protection film in the sealing PDLC element with the surface protection film of an Example and a comparative example. It is the schematic explaining the problem which may occur when the surface protection film is peeled off from the sealing PDLC element with a surface protection film.

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

A. Sealed PDLC element with surface protective film A-1. Overall Configuration of Sealed PDLC Device with Surface Protective Film FIG. 1 (a) is a schematic cross-sectional view of the sealed PDLC device with a surface protective film according to one embodiment of the present invention, and FIG. 1 (b) is FIG. It is a schematic top view of the sealed PDLC element with a surface protective film shown in (a). The sealed PDLC element 100a with a surface protective film includes a first transparent conductive film 11, a second transparent conductive film 12 arranged so as to face the first transparent conductive film 11, and a first transparent conductive film 12. A PDLC element 10 including a polymer-dispersed liquid crystal layer 13 arranged between the transparent conductive film 11 and the second transparent conductive film 12; on one side of the base material 21 and the base material 21. With the surface

protective films

20a and 20b provided with the pressure-sensitive adhesive layer 22 and laminated (bonded) on both main surfaces of the PDLC element 10 via the pressure-sensitive adhesive layer 22; the PDLC element 10 and the surface protection It has a sealing layer 30 provided on the entire surface of the end faces of the

films

20a and 20b;

In the sealed PDLC element 100a with a surface protective film shown in FIG. 1, either one of the surface

protective films

20a and 20b may be omitted depending on the purpose. Further, although not shown, an antifouling film for preventing stains and scratches may be further provided on the outermost surface of the sealed PDLC element 100a with a surface protective film, for example, until shipment. The sealing layer may also be provided so as to cover the end face of the antifouling film.

In the sealing PDLC element 100a with a surface protective film, the thickness of the sealing layer 30 (indicated by the reference numeral “t” in FIG. 1 (b)) is a (μm), and the base materials 21 of the surface

protective films

20a and 20b. When the thickness of the PDLC element 10 is c (μm) and the thickness of the PDLC element 10 is c (μm), a, b, and c satisfy all the relational expressions (1) to (3) (however, of the surface protective film 20a). When the base material thickness and the base material thickness of the surface protective film 20b are different, all the relational expressions (1) to (3) are satisfied for each base material thickness).
a <0.3c (1)
10 <b <150 (2)
a <0.4b (3)

The thickness (a: μm) of the sealing layer 30, the thickness (b: μm) of the base material 21 of the surface

protective films

20a and 20b, and the thickness (c: μm) of the PDLC element 10 are the relational expressions (1) to (1) to (1). When all of 3) are satisfied, the breaking force of the sealing layer is appropriately reduced due to the thinning of the sealing layer and the thickening of the surface protective film base material, and the sealing layer and the surface protective film are combined. Adhesion can be moderately increased. As a result, the surface protective film can be peeled off from the PDLC element without leaving the sealing layer in the state of burrs or debris on the surface of the PDLC element and without causing the problem of sealing removal.

The thickness of the sealing layer 30 (a: μm), the thickness of the base material 21 of the surface

protective films

20a and 20b (b: μm), and the thickness of the PDLC element 10 (c: μm) are preferably the relational expression (1'). ) To (3'), more preferably any two, and even more preferably all (the base material thickness of the surface protective film 20a and the base material thickness of the surface protective film 20b are different). In the case, with respect to the thickness of each base material, preferably any one of the relational expressions (1') to (3') is satisfied, more preferably any two are satisfied, and further preferably all are satisfied).
a ≤ 0.2c (1')
30 ≦ b ≦ 130 (2')
a ≤ 0.3b (3')

In one embodiment, the sealed PDLC element with a surface protective film may have a part of its end face as an exposed portion without a sealing layer. Since the exposed portion can function as a trigger for peeling, the operability when peeling the surface protective film from the PDLC element can be improved.

FIG. 2 is a schematic top view of an example of a sealed PDLC element with a surface protective film having an exposed portion. The sealed PDLC element 100b with a surface protective film has take-out

electrode portions

112 and 114 for applying a driving voltage to the rectangular PDLC element main body (main body portion functioning as a PDLC element) 110 and the PDLC element main body 110 in a top view. The sealing layer 30 is provided on the outer peripheral end faces excluding the take-out

electrode portions

112 and 114. In the illustrated example, the take-out electrode portion 112 is formed by extending a part of the first transparent conductive film constituting the PDLC element main body 110 outward from the main body 110, and the take-out electrode portion 114 is a PDLC element. It can be formed by extending a part of the second transparent conductive film constituting the main body 110 outward from the main body 110. In addition, unlike the illustrated example, the exposed portion may be provided at any appropriate location other than the take-out electrode portion. For example, the end faces of one or more corners of the sealed PDLC element with a surface protective film formed in a rectangular shape in top view can be used as an exposed portion.

A-2. PDLC element The PDLC element includes a first transparent conductive film, a second transparent conductive film arranged so as to face the first transparent conductive film, the first transparent conductive film, and the like. It includes a polymer-dispersed liquid crystal layer arranged between the second transparent conductive film.

As described in Section A-2-3 described later, in the PDLC element, the degree of light diffusion (as a result, haze) changes according to the application of voltage. In one embodiment, a case where the haze of the PDLC element is equal to or more than a predetermined value (for example, 30% or more, preferably 50% or more) is set as a scattering state, and the haze is less than a predetermined value (for example, less than 30%, preferably less than 30%). Is 15% or less, more preferably 10% or less), which can be said to be a transparent state. The voltage (driving voltage) applied to the PDLC element to control the degree of light diffusion is, for example, 100 V or less, preferably 50 V or less.

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

A-2-1. First Transparent Conductive Film The first transparent conductive film typically includes a first transparent substrate and a first transparent electrode layer provided on one side of the first transparent substrate. The first transparent electrode layer is arranged so as to be on the polymer-dispersed liquid crystal layer side. The first transparent conductive film may further have an arbitrary appropriate functional layer (refractive index adjusting layer, antireflection layer, hard coat layer, etc.) depending on the purpose.

The surface resistance value of the first transparent conductive film is preferably 0.1Ω / □ to 1000Ω / □, more preferably 0.5Ω / □ to 300Ω / □, and even more preferably 1Ω / □ to 200Ω. / □.

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

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

The first transparent electrode layer can be formed by using, for example, a metal oxide such as indium tin oxide (ITO), zinc oxide (ZnO), and tin oxide (SnO _2). In this case, the metal oxide may be an amorphous metal oxide or a crystallized metal oxide. Alternatively, the first transparent electrode layer may be formed of 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 depending on the purpose.

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.

The first transparent electrode layer can be typically provided on one surface of the first transparent substrate by using a method such as sputtering.

The first transparent substrate is formed from any suitable material. Specifically, a glass base material or a polymer base material is preferably used, and a polymer base material is more preferable.

The polymer base material is typically a polymer film containing 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; cellulose resins and the like. Of these, cycloolefin-based resins or polyethylene terephthalate-based resins can be preferably used. The above-mentioned thermoplastic resin may be used alone or in combination of two or more kinds.

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

A-2-2. Second Transparent Conductive Film The second transparent conductive film typically includes a second transparent substrate and a second transparent electrode layer provided on one side of the second transparent substrate. The second transparent electrode layer is arranged so as to be on the polymer-dispersed liquid crystal layer side. The second transparent conductive film may further have an arbitrary appropriate functional layer (refractive index adjusting layer, antireflection layer, hard coat layer, etc.) depending on the purpose.

The surface resistance value of the second transparent conductive film is preferably 0.1Ω / □ to 1000Ω / □, more preferably 0.5Ω / □ to 300Ω / □, and even more preferably 1Ω / □ to 200Ω. / □.

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%.

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

The same description as for the first transparent electrode layer and the first transparent base material can be applied to the second transparent electrode layer and the second transparent base material, respectively. The first transparent conductive film and the second transparent conductive film may have the same configuration or different configurations.

A-2-3. Polymer-dispersed liquid crystal layer The polymer-dispersed liquid crystal (PDLC) layer typically has a structure in which a liquid crystal compound is dispersed in a resin matrix. In the PDLC layer, the degree of scattering of transmitted light is changed through a change in the degree of orientation of the liquid crystal compound corresponding to the amount of voltage applied, whereby the transparent state and the scattered state can be switched.

In one embodiment, the PDLC layer becomes transparent when a voltage is applied, and becomes a scattered state when no voltage is applied (normal mode). In this embodiment, when no voltage is applied, the liquid crystal compound is not oriented, so that it is in a scattered state. When the voltage is applied, the liquid crystal compound is oriented and the refractive index of the liquid crystal compound and the refractive index of the resin matrix are aligned. , Becomes transparent.

In another embodiment, the PDLC layer becomes a scattered state when a voltage is applied, and becomes a transparent state when a voltage is not applied (reverse mode). In this embodiment, the alignment film provided on the surface of the transparent electrode layer causes the liquid crystal compound to be oriented and becomes transparent when no voltage is applied, and the orientation of the liquid crystal compound is disturbed by the application of voltage to cause a scattered state.

As the liquid crystal compound, any suitable non-polymerized liquid crystal compound is used. For example, nematic type, smectic type, and cholesteric type liquid crystal compounds can be mentioned. From the viewpoint of achieving excellent transparency in the transmission mode, it is preferable to use a nematic liquid crystal compound. Examples of the nematic liquid crystal compound include biphenyl compounds, phenylbenzoate compounds, cyclohexylbenzene compounds, azoxybenzene compounds, azobenzene compounds, azomethine compounds, terphenyl compounds, biphenylbenzoate compounds, and cyclohexylbiphenyl compounds. , Phenylpyridine compounds, cyclohexylpyrimidine compounds, cholesterol compounds and the like.

The content ratio of the liquid crystal compound in the PDLC layer is, for example, 10% by weight or more, preferably 30% by weight or more, more preferably 35% by weight or more, still more preferably 40% by weight or more. The content ratio is, for example, 90% by weight or less, preferably 70% by weight or less.

The resin forming the resin matrix can be appropriately selected depending on the light transmittance, the refractive index of the liquid crystal compound, the adhesion to the transparent conductive film, and the like. For example, water-soluble resins such as urethane resins, polyvinyl alcohol resins, polyethylene resins, polypropylene resins, acrylic resins, water-dispersible resins and liquid crystal polymers, (meth) acrylic resins, silicone resins, epoxy resins. , Fluorine-based resin, polyester-based resin, polyimide resin and other curable resins can be mentioned.

The content ratio of the matrix-forming resin in the PDLC layer is, for example, 90% by weight or less, preferably 70% by weight or less, more preferably 65% by weight or less, and further preferably 60% by weight or less. The content ratio is, for example, 10% by weight or more, preferably 30% by weight or more.

The thickness of the PDLC layer is, for example, 50 μm or less, preferably 30 μm or less, more preferably 20 μm or less, still more preferably 15 μm or less. The lower limit of the thickness of the PDLC layer can be, for example, 5 μm.

The PDLC layer can be made by any suitable method. Specific examples include methods for producing an emulsion method and a phase separation method.

The method for producing an emulsion-type PDLC layer is, for example, to form a coating layer by applying an emulsion coating liquid containing a matrix-forming resin and a liquid crystal compound to the transparent electrode layer surface of one of the transparent conductive films. , And drying the coating layer to form a resin matrix on the matrix-forming resin. The emulsion coating liquid is preferably an emulsion containing a mixed solution of a matrix-forming resin and a coating solvent in a continuous phase and a liquid crystal compound in a dispersed phase. By coating and drying the emulsified coating liquid, a PDLC layer having a structure in which a liquid crystal compound is dispersed in a resin matrix can be formed. Typically, a PDLC element is obtained by laminating the other transparent conductive film on the PDLC layer.

The method for producing a phase-separated PDLC layer is, for example, a coating layer in which a coating liquid containing a radiation-curable matrix-forming resin and a liquid crystal compound is applied to the transparent electrode layer surface of one of the transparent conductive films. The resin matrix is formed by forming a laminate by laminating the other transparent conductive film on the coating layer, and irradiating the laminate with radiation to polymerize the matrix-forming resin. Including phase separation from the liquid crystal compound, which gives a PDLC element. The coating liquid is preferably in a uniform phase state. Alternatively, a coating liquid may be filled between the first transparent conductive film and the second transparent conductive film laminated via a spacer, and then phase separation by irradiation may be performed.

A-3. Surface Protective Film The surface protective film comprises a base material and an adhesive layer provided on one side of the base material. The surface protective film is provided to prevent scratches and stains on the surface of the PDLC element, and is usually peeled off and removed before the PDLC element is used. When surface protective films are provided on both sides of the PDLC element, surface protective films having the same configuration may be used, or surface protective films having different configurations may be used.

The thickness of the surface protective film is, for example, 15 μm to 200 μm, preferably 30 μm to 150 μm.

Examples of the material for forming the base material include ester resins such as polyethylene terephthalate resins, cycloolefin resins such as norbornene resins, olefin resins such as polypropylene, polyamide resins, polycarbonate resins, and co-weights thereof. Examples include resin. An ester resin (particularly, a polyethylene terephthalate resin) is preferable.

The thickness of the base material is set within a range that satisfies the above formulas (2) and (3). The thickness of the base material 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 base material thickness of the surface protective film is within the above range, problems such as sealing can be prevented, and the surface protective film can be suitably peeled from the PDLC element.

The pressure-sensitive adhesive layer is formed by any suitable pressure-sensitive adhesive composition. Specific examples of the pressure-sensitive adhesive composition include pressure-sensitive adhesive compositions using (meth) acrylic polymers, silicone-based polymers, polyesters, polyurethanes, polyamides, polyethers, fluorine-based polymers, rubber-based polymers, and the like as base polymers. .. Among them, an acrylic pressure-sensitive adhesive composition using an acrylic polymer as a base polymer is preferable from the viewpoint of transparency, weather resistance, heat resistance and the like.

The thickness of the pressure-sensitive adhesive layer is, for example, 3 μm to 100 μm, preferably 4 μm to 80 μm, and more preferably 5 μm to 60 μm.

A-4. Sealing layer The sealing layer is provided on the end faces of the PDLC element and the surface protective film for the purpose of preventing leakage of the liquid crystal compound, improving durability, and the like. In one embodiment, an organic material can be used as the material for forming the sealing layer. Specific examples of the organic material include curing of UV curable resin (for example, UV curable acrylic resin), thermocurable resin (for example, thermocurable urethane resin, acrylic resin, urethane acrylic resin and a mixture thereof). Mold resin can be mentioned. As the curable resin, a curable resin similar to the resin for forming the resin matrix of the PDLC layer can be used. Further, an organic material that can be formed by vapor deposition (including vapor deposition polymerization) can also be used. Examples of such an organic material include a dimer (di-p-xylene) capable of forming a parylene film by vapor deposition polymerization, a monomer capable of forming a polyurethane film (diol and diisocyanate), and a monomer capable of forming a polyimide film (diamine). And acid anhydride), monomers capable of forming a polyurea film (diamine and diisocyanate), and the like. When a vapor-deposited film is used, a highly dense sealing layer can be obtained. In another embodiment, an inorganic material can be used as the material for forming the sealing layer. Specific examples of the inorganic material include metals such as zinc, aluminum, titanium, copper and magnesium, or oxides of metalloids such as silicon, bismuth and germanium, nitrides, carbides, nitride oxides, carbide oxides, carbide nitrides and oxides. Carbide nitride and the like can be mentioned. Further, the sealing layer may be formed by using a resin containing an inorganic material such as inorganic fine particles, or may include a laminated structure of a resin layer and an inorganic layer.

The sealing layer is typically obtained by applying a material for forming the sealing layer (for example, a composition containing the above-mentioned curable resin and / or inorganic material) to the end face of a PDLC element with a surface protective film and curing the sealing layer. Can be formed. Examples of the coating method include spray coating, dispenser coating, brush coating, screen printing, dipping, and vapor deposition.

The resin composition containing the curable resin can contain a polymerization initiator (for example, "Irgacure TPO" manufactured by BASF), if necessary. Further, from the viewpoint of improving adhesion, a silane coupling agent (for example, "KBM903" manufactured by Shinetsu Silicone Co., Ltd.) and an adhesion auxiliary agent (for example, "KAYAMER® PM-2" manufactured by Nippon Kayaku Co., Ltd.) are used. You may use it.

The thickness of the sealing layer is set within a range satisfying the above formulas (1) and (3). The thickness of the sealing layer when formed of 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 thin-film film, the thickness thereof may be preferably 0.05 μm to 5 μm, more preferably 0.2 μm to 1 μm. The thickness of the sealing layer when formed of 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.

The breaking elongation of the material forming the sealing layer (the breaking elongation of the film obtained by forming the material forming the sealing layer to a thickness of 50 μm) is not particularly limited as long as the effect of the present invention can be obtained. However, the lower limit is usually 1% or more, while 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, 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.
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, applied on a polyester film that has undergone a mold release treatment, and allowed to stand at room temperature for 1 hour. , 70 ° C. for 3 hours to prepare a resin film having a thickness of 50 μm. A film sample having a width of 10 mm and a length of 50 mm is cut out from the resin film. Using Autograph AGS-X (manufactured by Shimadzu Corporation), a tensile test is performed at a chuck distance of 30 mm and a tensile speed of 200 mm / min, and the elongation at break is measured.
When the material forming the sealing layer is a fat-soluble resin, a solution of the resin composition is prepared using an arbitrary organic solvent, and a resin film is prepared in the same manner as described above. When the material forming the sealing layer is an energy active ray-curable resin such as an ultraviolet curable resin, a solution of an arbitrary energy active ray curable resin is prepared, applied on a polyester film, and the energy active ray such as ultraviolet irradiation is applied. Is irradiated to prepare a resin film. Alternatively, a film having a thickness of 50 μm may be formed by any other method such as thin film deposition. The elongation at break can be measured for these films in the same manner as described above.

B. Manufacturing Method The sealed PDLC device with a surface protective film according to Item A can be manufactured by any suitable manufacturing method. In one embodiment, the method for manufacturing a sealed PDLC element with a surface protective film is a roll-to-roll method in which a long surface protective film is attached to one or both surfaces of a long PDLC element. In addition, a PDLC element with a long surface protective film is obtained, a PDLC element with a long surface protective film is cut into a desired shape to obtain a single-wafer-shaped PDLC element with a surface protective film, and a sheet is obtained. It includes forming a sealing layer on the entire surface of the end face of the PDLC element with a leaf-shaped surface protective film or except for a part (exposed portion). If necessary, the end face of the PDLC device with a surface protective film before forming the sealing layer may be surface-treated. By applying the surface treatment, it is possible to reduce the surface tension of the treated surface, remove minute foreign substances (for example, organic substances), and smooth the treated surface. As a result, the end face of the PDLC element and the sealing layer Adhesion strength can be improved. Examples of such a surface treatment include coating of an easily adhesive material, UV ozone treatment, plasma treatment and the like.

The sealing layer may be formed individually for the PDLC element with a surface protective film cut into a desired shape, or may be collectively performed for a laminate of a plurality of PDLC elements with a surface protective film. Good. By forming a sealing layer on a laminated body of a plurality of PDLC elements with a surface protective film at once, the efficiency of the sealing process can be remarkably improved, and as a result, the sealing with the surface protective film is performed with high manufacturing efficiency. A PDLC element can be obtained.

FIG. 3 is a schematic view illustrating an example of a manufacturing method in which a sealing layer is collectively formed on a laminated body of PDLC elements with a surface protective film. In the manufacturing method shown in FIG. 3, long surface

protective films

20a and 20b are attached to both sides of a long PDLC element 10 in a roll-to-roll manner to provide a long surface protective film. Obtaining a PDLC element 50 (bonding), cutting a long PDLC element 50 with a surface protective film into a desired shape to obtain a single-wafer-shaped PDLC element 50a with a surface-protecting film (punching), single-wafer-shaped A plurality of PDLC elements 50a with a surface protective film are laminated to obtain a laminated body 50b (manufacturing of a laminated body), a sealing layer 60 is integrally formed on the end face of the laminated body 50b (sealing treatment), and This includes separating the laminate 50c on which the sealing layer is formed into individual sealing PDLC elements 100 with a surface protective film (single-waving). Although not shown, even if a long antifouling film is attached to one or both surfaces of the PDLC element 50 with a long surface protective film in a roll-to-roll format, and then the processing after punching is performed. Good. Further, in the illustrated example, the sealing layer 60 is formed on the entire surface of the end face of the laminated body 50b, but unlike the illustrated example, a part of the end face of the laminated body 50b (for example, the end face of the take-out electrode portion) is formed. It may be an exposed portion without forming a sealing layer.

It is a laminated body in which two or more sealing dimming elements with a surface protective film are laminated, and the sealing layer is integrally formed on the end face of the laminated body (in other words, the sealing layer is a laminated body of the laminated body. As a method of separating the laminated body 50c (which is continuously formed in the direction) into individual sealed PDLC elements 100 with a surface protective film, for example, a release tool such as a spatula is attached to an adjacent sealed PDLC element with a surface protective film. Examples include inserting the device between the devices to separate the device, and peeling the sealed PDLC element with a surface protective film from the adjacent device to separate the device by using the exposed portion as a trigger.

The number of single-wafer-shaped PDLC elements 50a with a surface protective film contained in the laminate 50b is not limited as long as the effects of the present invention can be obtained, and is preferably 3 or more, more preferably 10 to 200, still more preferably 50. It can be up to 100.

To form the sealing layer on the laminated body 50b, for example, surface treatment is arbitrarily applied to the entire surface of the end face of the laminated body 50b or a portion excluding the exposed portion, and then the material for forming the sealing layer (for example, the cured type). It can be done by applying a resin and / or a composition containing an inorganic or organic material) and curing if necessary. Examples of the coating method include the coating methods exemplified in Section A-4, and among them, spray coating or vapor deposition is preferable.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "parts" and "%" in Examples and Comparative Examples are based on weight.

[Example 1]
(Manufacturing of PDLC element)
A transparent electrode layer (ITO layer) with a thickness of 0.08 μm is formed on one surface of a transparent base material (norbornene resin film (manufactured by Zeon Corporation, product name "ZF-16"), thickness: 40 μm) by a sputtering method. Then, it was annealed at 150 ° C. and crystallized. In this way, first and second transparent conductive films having a structure of [COP base material / transparent electrode layer] were obtained.
On the surface of the first transparent conductive film on the transparent electrode layer side, 40 parts of a liquid crystal compound (manufactured by HCCH, product name "HPC854600-100", birefringence Δn = 0.232) and a UV curable resin (manufactured by Norland). , Product name "NOA65") 60 parts (solid content) was applied to form a coating layer. Next, a second transparent conductive film was laminated on the coating layer so that the transparent electrode layer faces the coating layer. The obtained laminate was irradiated with ultraviolet rays to cure the UV curable resin, thereby forming a PDLC layer having a thickness of 20 μm. As described above, a PDLC device (thickness 100 μm) was obtained.

(Manufacturing of PDLC element with surface protection film)
A surface protective film (manufactured by Nitto Denko KK, product name "RP207") having a PET-based resin base material (38 μm) and an acrylic adhesive layer (21 μm) provided on one side of the PET-based resin base material (38 μm) is bonded to both sides of the PDLC element. A PDLC device with a surface protective film was obtained.

(Sealing process)
A resin composition for forming a sealing layer was applied to the entire surface of the end face of the PDLC element with a surface protective film, and the resin composition was cured by heating and drying at 70 ° C. for 3 hours to form a sealing layer having a thickness of 10 μm. As the coating liquid of the resin composition for forming the sealing layer, the breaking elongation of the film formed by forming the acrylic resin emulsion aqueous solution, the polyolefin resin and the isocyanate-based curing agent so as to have a thickness of 50 μm is 10%. Was blended and mixed with.

As described above, a sealed PDLC element with a surface protective film was obtained.

[Examples 2 to 8, Comparative Examples 1 to 5]
A sealed PDLC device with a surface protective film was obtained in the same manner as in Example 1 except that the substrate thickness of the PDLC element, the sealing layer and / or the surface protective film was changed as shown in Table 1.

[Example 9]
(Manufacturing of PDLC element)
A PDLC device (thickness 100 μm) was obtained in the same manner as in Example 1.
(Manufacturing of PDLC element with surface protection film)
A surface protective film having a PET-based resin base material (30 μm) and an acrylic pressure-sensitive adhesive layer (10 μm) provided on one side of the PET-based resin base material (30 μm) was bonded to both sides of the PDLC element to obtain a PDLC element with a surface-protected film.
(Sealing process)
The entire surface of the end face of the PDLC element with the surface protection film was subjected to plasma treatment. A parylene coating layer (sealing layer) having a thickness of 5 μm was formed on the plasma-treated surface by a vacuum vapor deposition method using a parylene raw material (manufactured by Kisco, product name “dixC”).

[Comparative Example 6]
A sealed PDLC element with a surface protective film was obtained in the same manner as in Example 9 except that the thickness of the sealing layer was 15 μm.

In the sealed PDLC element with a surface protective film obtained in the above Examples and Comparative Examples, one surface protective film was peeled from the PDLC element using a release tool. The end of the PDLC element after peeling was observed under a microscope, and the presence or absence of "burrs" and "sealing" was evaluated. The results are shown in Table 2 and FIG.

As shown in Table 2 and FIG. 4, according to the sealing PDLC element with the surface protective film of the embodiment, the surface protective film is preferably removed from the PDLC element without leaving the residue of the sealing layer on the surface of the PDLC element. Can be peeled off.

The sealed dimming element with a surface protective film of the present invention is suitably used for a display device having a dimming function, an optical member having an optical shutter function, and the like.

100 Sealed dimming element with surface protective film 10 Dimming element 11 First transparent conductive film 12 Second transparent conductive film 13 Polymer-dispersed liquid crystal layer 20 Surface protective film 21 Base material 22 Adhesive layer 30 Sealed Stop layer

Claims

A first transparent conductive film, a second transparent conductive film arranged so as to face the first transparent conductive film, the first transparent conductive film, and the second transparent conductive film. A dimming element provided with a polymer-dispersed liquid crystal layer arranged between the film and the film.
A surface protective film comprising a base material and an adhesive layer provided on one side of the base material, and laminated on at least one main surface of the dimming element via the pressure-sensitive adhesive layer.
It has a dimming element and a sealing layer provided on the end face of the surface protective film.
When the thickness of the sealing layer is a (μm), the thickness of the base material of the surface protective film is b (μm), and the thickness of the dimming element is c (μm), the relational expressions (1) to (3) A sealed dimming element with a surface protection film that meets all of the requirements.
a <0.3c (1)
10 <b <150 (2)
a <0.4b (3)
10. The first aspect of claim 1, wherein the first transparent conductive film and the second transparent conductive film each have a transparent base material and a transparent electrode layer provided on one side of the transparent base material. Sealed dimming element with surface protection film.
The sealing dimming element with a surface protective film according to claim 1 or 2, wherein the sealing layer contains a resin having a breaking elongation of 5% to 30% when molded into a film having a thickness of 50 μm.
The sealing dimming element with a surface protective film according to any one of claims 1 to 3, wherein a part of the end face is an exposed portion not provided with a sealing layer.
A laminate in which two or more sealing dimming elements with a surface protective film according to any one of claims 1 to 4 are laminated.
A laminate in which the sealing layer is integrally formed on the end face of the laminate.