JP2018005040A - Light control film and method for forming the light control film - Google Patents

Abstract

The present invention relates to a light control film by a VA method and the like, which enables stable and accurate production using a bead spacer. In a light control film 1 in which a liquid crystal layer 8 is sandwiched between first and second laminated bodies 5 and 6 and the transmitted light is controlled by controlling the orientation of liquid crystal molecules related to the liquid crystal layer 8, The laminate 5 includes a first transparent electrode 11, a first bead fixing layer 12, and a first alignment layer 14 on a first substrate 10, and the second laminate 6 is a second substrate. 15 includes a second transparent electrode 16, a second bead fixing layer 17, and a second alignment layer 19. At least the first laminated body 5 includes a first bead spacer 13 embedded in the first bead fixing layer 12. [Selection] Figure 1

Description

  The present invention relates to a light control film that is applied to, for example, a sunroof of a vehicle and controls transmission of incident light.

  Conventionally, for example, various devices relating to a light control film that is attached to a window to control the transmission of external light have been proposed (Patent Documents 1 and 2). One such light control film uses liquid crystal. The light control film using the liquid crystal is manufactured by sandwiching a liquid crystal material with a transparent film material on which a transparent electrode and an alignment layer are manufactured, and manufacturing the liquid crystal cell with a linear polarizing plate. As a result, in this light control film, the orientation of the liquid crystal is changed by changing the electric field applied to the liquid crystal, thereby blocking or transmitting the extraneous light, and further changing the amount of transmitted light. To control.

  It is considered that various driving methods proposed for the liquid crystal display panel can be applied to driving the liquid crystal cell. Specifically, for example, a driving method such as a TN (Twisted Nematic) method, an IPS (In-Place-Switching) method, or a VA (Virtual Alignment) method can be applied. In addition, it is conceivable to improve the viewing angle characteristics by multi-domaining.

  The VA method is a method of controlling transmitted light by changing the alignment of liquid crystal between vertical alignment and horizontal alignment. Generally, the liquid crystal layer is vertically aligned by vertically aligning the liquid crystal when no electric field is applied. A liquid crystal cell is formed by sandwiching the liquid crystal material, and the liquid crystal material is horizontally aligned by application of an electric field. Multi-domaining is the provision of multiple regions where the behavior of liquid crystal molecules differs with respect to variable electric fields. In general, the viewing angle characteristics are improved by averaging (integrating) the optical properties in these multiple regions. Applied for.

  In the liquid crystal display panel, as a method for adjusting the cell gap, which is the thickness of the liquid crystal layer, a method of spraying bead spacers in a spherical shape or a rod shape has been proposed. Has been proposed. For liquid crystal display panels, for example, as disclosed in Patent Document 4, a method of injecting liquid crystal in a short time by an ODF (One Drop Filling) method has been proposed. Here, the dropping injection method is a method of manufacturing a liquid crystal layer by dropping a liquid crystal material and then spreading it by a base material related to a liquid crystal cell. In this method, in general, the liquid crystal material is dropped and spread inside the seal material having a frame shape manufactured in advance. However, after the liquid crystal material is dropped, the seal material is arranged and spread. Good.

  By the way, a light control film needs to be lightened by using a transparent film material for a base material by sticking it on a window. Thus, when manufacturing a liquid crystal cell using a transparent film material, it is possible to manufacture a liquid crystal cell by manufacturing a transparent electrode etc. sequentially in the state which hold | maintained the transparent film material on support bodies, such as a glass plate. . However, this method requires that the transparent film material is peeled off from the support locally during the manufacturing process, so that it is necessary to re-attach the transparent film material to the support, and the light control film cannot be produced efficiently. There's a problem.

  In addition, the light control film is desired to efficiently produce a large area product while ensuring sufficient characteristics with a simple configuration. As a result, it is conceivable to produce efficiently by arranging the constituent members sequentially while pulling out and transporting the base material made of a long transparent film material from the roll so as to produce by the simple VA method.

  In addition, it is conceivable to secure a cell gap by a simple manufacturing process by applying a bead spacer by arranging various constituent members while pulling out and transporting the substrate. Further, it is conceivable to shorten the manufacturing time by injecting the liquid crystal material in a short time by the dropping injection method.

  However, when manufacturing a liquid crystal cell in this way, it has been found that when the liquid crystal material is spread out by the dropping injection method, the bead spacer moves together with the liquid crystal material, and as a result, the bead spacer arrangement is biased. As a result, it was found that when a light control film by the VA method or the like is manufactured by a dropping injection method using a bead spacer, the light control film cannot be manufactured stably and accurately.

JP 03-47392 A Japanese Patent Laid-Open No. 08-184273 Japanese Patent Laid-Open No. 04-324825 JP 2003-241199 A

  This invention is made | formed in view of such a condition, and it aims at enabling it to manufacture stably and accurately using a bead spacer regarding the light control film by a VA system.

  The present inventor has conducted extensive research to solve the above-mentioned problems, and disperses the bead spacers in the coating solution of at least one bead fixing layer by providing a bead fixing layer between the transparent electrode and the alignment layer. This led to the idea that the bead spacer is difficult to move, and the present invention has been completed.

  Specifically, the present invention provides the following.

(1) In a light control film that sandwiches a liquid crystal layer between first and second laminates and controls transmitted light by controlling the orientation of liquid crystal molecules related to the liquid crystal layer,
The first laminate is
A first transparent electrode, a first bead fixing layer, and a first alignment layer are provided on a first substrate,
The second laminate is
A second transparent electrode, a second bead fixing layer, a second alignment layer are provided on the second substrate,
At least the first laminate is
A light control film comprising a first bead spacer embedded in a first bead fixing layer. Here, the bead fixing layer means a layer that exhibits a function of fixing the bead spacer when the bead spacer is arranged regardless of the presence or absence of the bead spacer.

  According to (1), since the first and second bead fixing layers are provided in the first and second stacked bodies, respectively, the electric field is made uniform in the thickness direction of the liquid crystal layer. It is possible to prevent such a phenomenon that ions or the like are localized on one side of the transparent electrode, making it difficult to efficiently apply an electric field to the liquid crystal layer. In addition, since at least the first laminate includes the first bead spacer embedded in the first bead fixing layer, the first bead spacer is held difficult to move by the first bead fixing layer. Can be secured. As a result, even if the liquid crystal material is expanded by the dropping injection method, the first bead spacer can be prevented from moving. Thereby, when applying a bead spacer and manufacturing the light control film by VA system etc. by a dripping injection system, a light control film can be manufactured stably and accurately.

(2) In (1), the second laminate is
A light control film comprising a second bead spacer embedded in the second bead fixing layer.

  According to (2), the same structure is applied to the 1st and 2nd bead fixed layer which concerns on a 1st and 2nd laminated body, and a light control film can be manufactured.

(3) In (1) or (2),
The first and second bead fixing layers are:
A light control film having a refractive index of 1.55 or more and 1.65 or less.

  According to (3), it is possible to reduce the reflection at the interface of the bead fixing layer and improve the transmittance.

(4) In any one of (1) to (3)
The first and second bead fixing layers are:
A light control film having a volume resistivity of 1 × 10 ¹⁰ Ω · cm or less.

  According to (4), charge accumulation in the liquid crystal layer can be suppressed.

(5) In any one of (1) to (4),
The first and second bead fixing layers are:
A light control film having a volume resistivity of 1 × 10 ⁸ Ω · cm or more.

  According to (5), it is possible to effectively avoid malfunction due to conduction between the electrodes of the upper and lower substrates.

(6) In the method for producing a light control film, the liquid crystal layer is sandwiched between the first and second laminates, and the alignment of liquid crystal molecules related to the liquid crystal layer is controlled to control the transmitted light.
A first laminate manufacturing process for manufacturing the first laminate;
A second laminate manufacturing process for manufacturing the second laminate,
The first laminate manufacturing process includes:
A first transparent electrode manufacturing process for manufacturing a first transparent electrode on a first substrate;
A first bead fixing layer manufacturing step for manufacturing a first bead fixing layer on the first transparent electrode;
A first alignment layer manufacturing step of manufacturing a first alignment layer on the first bead fixing layer,
The second laminate manufacturing process includes:
A second transparent electrode manufacturing process for manufacturing a second transparent electrode on the second substrate;
A second bead fixing layer manufacturing step of manufacturing a second bead fixing layer on the second transparent electrode;
A second alignment layer manufacturing step of manufacturing a second alignment layer on the second bead fixing layer,
The first bead fixing layer manufacturing process includes:
A process for producing a light control film for coating the first bead fixing layer including the first bead spacer, and manufacturing the first bead fixing layer formed by burying the first bead spacer. .

  According to (6), by providing the first and second bead fixing layers on the first and second laminates, respectively, the electric field is made uniform in the thickness direction of the liquid crystal layer, and the first and second transparent electrodes It is possible to prevent such a phenomenon that ions are localized on one side of the liquid crystal and it becomes difficult to efficiently apply an electric field to the liquid crystal layer. Further, by providing the first bead spacer buried in the first bead fixing layer, it is possible to secure the cell gap while keeping the first bead spacer difficult to move. As a result, even if the liquid crystal material is expanded by the dropping injection method, the first bead spacer can be prevented from moving. Thereby, when applying a bead spacer and manufacturing a light control film by the VA method by the dropping injection method, the light control film can be manufactured stably and accurately.

  (7) In (6), a liquid crystal material manufacturing process comprising a liquid crystal cell control process for manufacturing a liquid crystal cell by pressing and spreading the dropped liquid crystal material by the first and second laminates.

  According to (7), a liquid crystal material can be arrange | positioned with a dripping injection system, the time used for arrangement | positioning of a liquid crystal material can be shortened, and a light control film can be manufactured efficiently.

  According to the present invention, a light control film by the VA method or the like can be manufactured stably and accurately using a bead spacer.

It is sectional drawing which shows the light control film which concerns on 1st Embodiment of this invention. It is a flowchart which shows the manufacturing process of the light control film of FIG. It is a figure which shows the electric field of the liquid crystal layer by resistance value. It is a figure which shows the electric field of a liquid crystal layer in case the thickness of a bead fixing layer is varied. It is a figure which expands and shows FIG. 4 partially. It is a graph which shows the result of having simulated the mode of charge to a liquid crystal layer by volume resistivity.

[First Embodiment]
FIG. 1 is a cross-sectional view showing a light control film according to the first embodiment of the present invention. This light control film 1 is used by being attached to an area for light control such as a window glass of a building, a showcase, an indoor transparent partition, etc. with an adhesive layer or the like, and the amount of transmitted light can be reduced by changing the applied voltage. Control.

  The light control film 1 is a film material that controls transmitted light using liquid crystal, and is configured by sandwiching a liquid crystal cell 4 for light control film between first and second linearly polarizing plates 2 and 3. Here, the linear polarizing plates 2 and 3 are formed by impregnating polyvinyl alcohol (PVA) with iodine or the like, and then stretched to form an optical functional layer that performs an optical function as a linear polarizing plate. TAC (triacetyl cellulose) An optical functional layer is sandwiched between base materials made of a transparent film material such as the above. The linearly polarizing plates 2 and 3 are arranged in the liquid crystal cell 4 by an adhesive layer made of an ultraviolet curable resin or the like in a crossed Nicol arrangement. The linearly polarizing plates 2 and 3 may be so-called E type coating type linearly polarizing plates. The linear polarizing plate 3 may be provided with a retardation film for optical compensation on the liquid crystal cell 4 side.

  The liquid crystal cell 4 controls the polarization plane of the transmitted light by controlling the electric field, whereby the light control film 1 is configured so that various light control can be achieved by controlling the electric field.

[Liquid crystal cell]
The liquid crystal cell 4 is configured by sandwiching a liquid crystal layer 8 between a lower laminated body 5 and an upper laminated body 6 which are first and second laminated bodies having a film shape. In the lower laminated body 5, a first transparent electrode 11, a first bead fixing layer 12, a first bead spacer 13, and a first alignment layer 14 are sequentially arranged on a first base material 10 made of a transparent film material. Is done. In the upper laminate 6, a second transparent electrode 16, a second bead fixing layer 17, a second bead spacer 18, and a second alignment layer 19 are sequentially arranged on a second base material 15 made of a transparent film material. The As a result, the liquid crystal cell 4 is driven by the first and second transparent electrodes 11 and 16 provided in the lower laminate 5 and the upper laminate 6, and the liquid crystal material provided in the liquid crystal layer 8 by the VA method. The orientation is controlled, thereby controlling the plane of polarization of the transmitted light.

  Further, the light control film 1 has a frame shape surrounding a portion where the liquid crystal layer 8 is disposed, and the sealing material 23 is disposed on the lower laminate 5, and the liquid crystal material 8 </ b> A is disposed inside the frame shape by the sealing material 23. Thus, the liquid crystal layer 8 is manufactured, and the lower stacked body 5 and the upper stacked body 6 are integrally held.

  The base materials 10 and 15 are supports such as the transparent electrodes 11 and 16, and various transparent film materials applicable to this type of film material can be applied, but a film material with small optical anisotropy is used. It is desirable to apply. In this embodiment, the base materials 10 and 15 are made of the same material and transparent film material having the same thickness, and more specifically, a polycarbonate film is applied, but a COP (cycloolefin polymer) film or the like is applied. May be.

  The transparent electrodes 11 and 16 are electrodes for applying an electric field to the liquid crystal layer 8, and various electrode materials applied to this type of film material can be applied. In this embodiment, ITO (Indium Tin Oxide) is used. ).

  The bead spacers 13 and 18 are provided to define the thickness of the liquid crystal layer 8. The bead spacers 13 and 18 can be widely applied to a configuration of an inorganic material such as silica, a configuration of an organic material, a configuration of a core-shell structure combining these, and the like. Moreover, you may comprise by the rod shape by cylindrical shape, prismatic shape, etc. other than the structure by spherical shape. Although the bead spacers 13 and 18 are manufactured by a transparent member, the color may be adjusted by applying a colored material as necessary. The bead spacers 13 and 18 are arranged on the transparent electrodes 11 and 16 by random arrangement. The bead spacers 13 and 18 have the same shape and the same size, and more specifically, spherical shapes having the same diameter are applied. However, different shapes may be applied to the bead spacers 13 and 18, for example, when a spherical shape and a rod shape are respectively applied. The bead spacers 13 and 18 have a diameter obtained by adding the thickness of a bead spacer fixing bead spacer 12 or 17 to be described later to the cell gap which is the thickness of the liquid crystal layer 8, and the diameter is 6 μm or less and 5 μm or more. It is formed.

  The bead spacers 13 and 18 are disposed on the entire surfaces of the base materials 10 and 15, and are thereby also disposed at a portion where a seal material 23 described later is disposed.

  The bead fixing layers 12 and 17 are resin layers for dispersing the bead spacers 13 and 18 on the transparent electrodes 11 and 16 and fixing the bead spacers 13 and 18 on the transparent electrodes 11 and 16, respectively. It is. Various materials such as an inorganic material and an organic material can be applied to the bead fixing layers 12 and 17, but in this embodiment, an inorganic material is applied. Specifically, tin oxide can be applied. Here, the bead fixing layer means a layer that exhibits a function of fixing the bead spacer when the bead spacer is arranged regardless of the presence or absence of the bead spacer.

  The alignment layers 14 and 19 are formed of a photo-alignment layer. Here, as the photo-alignment material applicable to the photo-alignment layer, various materials to which the photo-alignment technique can be applied can be widely applied. However, in this embodiment, for example, a light dimerization type material is used. . The light dimerization type material is described in “M. Schadt, K. Schmitt, V. Kozinkov and V. Chigrinov: Jpn. J. Appl. Phys., 31, 2155 (1992)”, “M. Schadt, H. Seiberle and A. Schuster: Nature, 381, 212 (1996). In addition, it may replace with a photo-alignment layer and may manufacture by a rubbing process. In the case of manufacturing by rubbing treatment, the alignment layers 14 and 19 are made of various material layers applicable to the alignment layer such as polyimide, and then fine line-like irregularities are formed on the surface of the material layer by rubbing treatment using a rubbing roll. Formed by manufacturing the shape. Moreover, it may replace with the alignment layer by such a rubbing process, and a photo-alignment layer, and may manufacture the alignment layer by manufacturing the fine line-shaped uneven | corrugated shape manufactured by the rubbing process by a shaping process.

  Various liquid crystal materials applicable to this type of light control film can be widely applied to the liquid crystal layer 8. Specifically, for the liquid crystal layer 8, for example, a liquid crystal compound described in JP-A No. 2003-366484 can be used. Moreover, as a marketed product, liquid crystal materials, such as Merck MLC2166, can be applied, for example. In the case of the guest-host method, the liquid crystal layer 8 is mixed with a liquid crystal material and a dye for dimming, but a mixture of a liquid crystal material and a dye proposed for the guest-host method can be widely applied. it can.

  The sealing material 23 is provided to integrally hold the lower laminate 5 and the upper laminate 6 and prevent leakage of the liquid crystal material 8A. Here, for example, an epoxy resin, an ultraviolet curable resin, or the like can be applied to the sealing material 23. In this embodiment, the dropping injection method is applied to the arrangement of the liquid crystal material 8A in the region surrounded by the sealing material 23, whereby the liquid crystal material is arranged efficiently and in a short time.

[Detailed configuration of bead spacer]
The bead fixing layers 12 and 17 are disposed by applying a corresponding coating solution and drying and curing. In this embodiment, the bead spacers 13 and 18 are dispersed and mixed in the coating solution, whereby the bead spacers 13 and 18 are arranged on the transparent electrodes 11 and 16 in a random arrangement. Here, the beads spacers 13 and 18 can be arranged by a simple process by dispersing and mixing in the coating liquid in this way, and the light control film 1 can thereby be arranged. It is possible to simplify the process related to the setting of the cell gap.

  Further, the bead spacers 13 and 18 are arranged so as to be buried in the bead fixing layers 12 and 17 by being dispersed and mixed in the coating solution of the bead fixing layers 12 and 17 as described above, so that the transparent electrode The tips on the 11 and 16 side are arranged so as to contact the transparent electrodes 11 and 16. Thus, in this embodiment, even when the liquid crystal material is arranged by the dropping injection method, the bead spacer is prevented from moving together with the liquid crystal material, and the uneven arrangement of the bead spacer is prevented. Thereby, the light control film can be manufactured stably and accurately.

  Here, the bead fixing layers 12 and 17 are desirably thin from the viewpoint of efficiently applying an electric field to the liquid crystal layer 8. However, from the viewpoint of fixing the bead spacers 13 and 18 with sufficient strength to make it difficult to move, it is desirable to ensure a sufficient thickness. Accordingly, it is desirable that the bead fixing layers 12 and 17 are manufactured with a thickness of 0.1 μm or more and 1.0 μm or less, and preferably with a thickness of 0.1 μm or more and 0.5 μm or less.

  Moreover, although various materials, such as an inorganic material and an organic material, can be applied to the bead fixing layers 12 and 17, an organic material is applied in this embodiment.

Further, in the light control film 1, by holding the bead spacers 13 and 18 by the bead fixing layers 12 and 17 as described above, sufficient insulation can be achieved between the transparent electrodes 11 and 16 and the liquid crystal layer 8. . Here, the bead fixing layers 12 and 17 are set to have a volume resistivity of 1 × 10 ¹⁰ Ω · cm or less, more preferably 1 × 10 ⁹ Ω · cm or less, depending on selection of materials. The liquid crystal layer 8 has a volume resistivity of about 1 × 10 ¹³ Ω · cm, and the alignment layers 14 and 19 have a volume resistivity of about 1 × 10 ¹³ Ω · cm. Thereby, in the light control film 1, the electric charge accumulate | stored in the liquid-crystal layer 8 by the drive by the transparent electrodes 11 and 16 is discharged gradually via the bead fixing layers 12 and 17, and the malfunctioning by an accumulation charge is avoided effectively. Can do. Further, the liquid crystal layer 8 can be driven efficiently. Here, the volume resistivity can be measured by, for example, a surface resistance / volume resistance meter (product name: MODEL 152-1) manufactured by Trek Japan.

On the other hand, as shown in FIG. 1, the bead fixing layer is coated with beads on the surface and is in contact with the opposing substrate, so that if the resistivity is too low, the voltage of the liquid crystal layer is sufficiently increased due to current leakage. There is a problem that cannot be maintained. FIG. 6 shows a simulation of charging the liquid crystal layer when the volume resistivity is 1 × 10 ⁷ Ω · cm, 1 × 10 ⁸ Ω · cm, and 1 × 10 ¹³ Ω · cm. In this simulation, for the sake of simplicity, the bead fixing layer as a surface is not considered, and only the portion covering the beads is considered. As shown in FIG. 6, if it is 1 × 10 ⁸ Ω · cm or more, a voltage can be applied to the same extent as in the case of a sufficiently high resistance (1 × 10 ¹³ Ω · cm), but 1 × 10 ⁷ In the case of Ω · cm or less, charging is not sufficiently performed due to current leakage. For this reason, it is preferable that the volume resistivity of the bead fixing layer is 1 × 10 ⁸ Ω · cm or more.

FIG. 3 is a diagram showing a potential distribution in the thickness direction of the light control film 1 when the bead fixing layers 12 and 17 are produced with a thickness of 1 μm. In FIG. 3, symbols L7, L8, and L9 set the volume resistivity of the bead fixing layers 12 and 17 to 1 × 10 ⁷ Ω · cm, 1 × 10 ⁸ Ω · cm, and 1 × 10 ⁹ Ω · cm, respectively. Potential distribution. According to FIG. 3, when the volume resistivity of the bead fixing layers 12 and 17 is reduced, the potential distribution in the bead fixing layers 12 and 17 can be reduced, and the electric field applied to the liquid crystal layer 8 is increased accordingly. It can be seen that it can be driven efficiently.

FIG. 4 is a diagram showing a potential distribution in the thickness direction of the light control film 1 when the bead fixing layers 12 and 17 are produced with a thickness of 0.2 μm. FIG. 5 is a diagram showing the potential distribution of FIG. 4 and 5, reference numerals L8, L9, L10, and L11 denote volume resistivity of the bead fixing layers 12 and 17 of 1 × 10 ⁸ Ω · cm, 1 × 10 ⁹ Ω · cm, and 1 × 10 ^{10, respectively.} The potential distribution is set to Ω · cm and 1 × 10 ¹¹ Ω · cm. According to FIGS. 4 and 5, it is possible to confirm in more detail the increase in the voltage applied to the liquid crystal layer 8 by reducing the volume resistivity of the bead fixing layers 12 and 17.

  Here, even if the bead fixing layer is provided on only one side of the lower laminate 5 and the upper laminate 6 and the bead spacers are arranged, the cell gap can be maintained. In addition, even when the liquid crystal material is arranged by the dropping injection method, it is possible to prevent the bead spacer from moving together with the liquid crystal material, and to prevent the bead spacer from being unevenly arranged. Can be manufactured.

  However, when the bead spacer is provided only on one side of the lower laminate 5 and the upper laminate 6 in this way, the bead fixing layer for fixing the bead spacer is provided only on the side where the bead spacer is provided. Become. In this case, in the liquid crystal layer 8, the uniformity of the electric field is disturbed in the thickness direction, and ions and the like are localized on one side of the transparent electrodes 11 and 16 facing each other. As a result, in the light control film 1, it becomes difficult to efficiently apply an electric field to the liquid crystal layer 8, and a so-called burn-in phenomenon may occur. Note that image sticking in the light control film 1 is a phenomenon in which the transmittance cannot be changed sufficiently even if the applied voltage is changed.

  However, as in this embodiment, the bead spacers 13 and 18 are arranged on both the lower laminate 5 and the upper laminate 6 so that the bead spacers are fixed to the lower laminate 5 and the upper laminate 6 respectively. When the bead fixing layers 12 and 17 are disposed, the localization of such ions and the like can be sufficiently reduced, and an electric field can be efficiently applied to the liquid crystal layer 8 to prevent image sticking.

  Here, from the viewpoint of producing a uniform electric field by sufficiently reducing the bias of the electric field in the liquid crystal layer 8, the bead fixing layers 12 and 17 are the same material as the lower stacked body 5 and the upper stacked body 6. It is desirable to manufacture with the same thickness by using the same manufacturing conditions. As a result, in the thicknesses D12 and D17 of the bead fixing layers 12 and 17, respectively, the difference absolute value ABS (D12−D17) of the thicknesses D12 and D17 is manufactured to be 0.1 μm or less. The bead fixing layers 12 and 17 are manufactured so that the volume resistivity ratio is 2 times or less. As a result, the bead fixing layers 12 and 17 for fixing the bead spacers are arranged on both the lower laminate 5 and the upper laminate 6, respectively, and the localization of ions and the like can be more reliably reduced and efficiently performed. An electric field can be applied to the liquid crystal layer 8.

  In this way, the bead spacer is arranged only on one of the lower laminate 5 and the upper laminate 6 and the above-mentioned various conditions are satisfied without mixing the bead spacer on the side where the bead spacer is not arranged. A bead fixing layer may be provided.

  Further, in this embodiment, the bead spacers 13 and 18 are arranged on the entire surfaces of the base materials 10 and 15 so that the bead spacers 13 and 18 are arranged on both the lower laminate 5 and the upper laminate 6 in this way. As a result, the bead spacers 13 and 18 are also disposed at the portion where the sealing material 23 is disposed. Thereby, in the light control film 1, compared with the case where bead spacers 13 and 18 are not arrange | positioned in the site | part which arrange | positions the sealing material 23, the adhesive strength of the lower laminated body 5 and the upper laminated body 6 by the sealing material 23 is improved. Thus, the reliability of the light control film 1 can be improved.

  Further, in this embodiment, the bead fixing layers 12 and 17 for fixing the bead spacers have a refractive index set to a value between the refractive index of the liquid crystal layer 8 and the refractive index of the transparent electrodes 11 and 16, and more specifically. The refractive index is set to 1.55 or more and 1.65 or less, preferably 1.60 or more and 1.65 or less. Here, the ITO constituting the transparent electrodes 11 and 16 has a refractive index of 1.858, and the liquid crystal layer 8 has a refractive index of 1.50. The alignment layers 14 and 19 have a refractive index of 1.50. Thereby, the light control film 1 includes the interface between the liquid crystal layer 8 and the alignment layers 14 and 19, the interface between the alignment layers 14 and 19 and the bead fixing layers 12 and 17, the bead fixing layers 12 and 17 and the transparent electrodes 11 and 16. At the interface, the reflection of transmitted light is reduced and the decrease in transmittance is prevented.

〔Manufacturing process〕
FIG. 2 is a flowchart showing the manufacturing process of the light control film 1. In the liquid crystal cell 4, the first stacked body 5 is manufactured in the first stacked body manufacturing process SP2. Specifically, in the first laminate manufacturing process SP2, in the first electrode manufacturing process SP2-1, the first transparent electrode 11 made of ITO is formed on the first base material 10 by a vacuum film forming method such as sputtering. Is manufactured.

  In this subsequent manufacturing step, in the first spacer arrangement step SP2-2, a coating solution in which the bead spacer 13 is dispersed in the coating solution for the bead fixing layer 12 is applied by spin coating or the like, and then dried. The firing process is sequentially performed, whereby the first bead spacers 13 are randomly arranged on the entire surface of the base material 10, and the first bead fixing layer 12 is manufactured so that the bead spacers 13 are difficult to move. .

  Subsequently, in the first alignment layer manufacturing process SP2-3, this manufacturing process is performed by applying the coating liquid related to the alignment layer 14 and drying it, followed by curing by irradiation with ultraviolet rays, whereby the first alignment layer is formed. 14 is manufactured. Thus, in this embodiment, the first laminate 5 is manufactured.

  The manufacturing process of the light control film 1 is the 2nd laminated body manufacturing process SP3 which follows, and the 2nd laminated body 6 is manufactured similarly to 1st laminated body manufacturing process SP2. That is, in the second laminate manufacturing process SP3, the second transparent electrode 16 made of ITO is manufactured on the first base material 15 in the second electrode manufacturing process SP3-1, and then the second spacer arrangement process SP3. 2, the second bead spacer 18 and the second bead fixing layer 17 are disposed, and the second alignment layer 19 is disposed in the second alignment layer manufacturing step SP3-3. Thus, the second laminate 6 is manufactured.

  In this manufacturing process, in the subsequent liquid crystal cell manufacturing process SP4, the seal material 23 is applied to the lower laminate 5 in a frame shape using a dispenser, and then the liquid crystal material 8A is disposed in the frame-shaped portion. Furthermore, the liquid crystal material 8A arrange | positioned at the lower laminated body 5 is expanded by carrying out the lamination | stacking press of the upper laminated body 6 and the lower laminated body 5 in the pressure-reduced environment. Thereafter, in the manufacturing process, the sealing material 23 is cured by ultraviolet irradiation or the like, whereby the liquid crystal material 8A is arranged by the dropping injection method to manufacture the liquid crystal cell 4. In the arrangement of the liquid crystal material 8A, instead of the dropping injection method, after laminating the upper laminated body 6 and the lower laminated body 5, the liquid crystal material is arranged in the gap formed in the portion related to the liquid crystal layer. In various cases, various methods can be widely applied.

  The light control film 1 is formed by being laminated with the linearly polarizing plates 2 and 3 in the subsequent lamination step SP5. The liquid crystal cell 4 is provided in the form of a long film in which the base materials 10 and 15 are wound on a roll, and all of these processes SP2 to SP5 or a part of these processes SP2 to SP5 are based on the roll. It is executed while the materials 10 and 15 are pulled out and conveyed. In this way, each step of the liquid crystal cell 4 is executed by a single wafer process from an intermediate step as necessary.

〔Experimental result〕
Table 1 is a chart showing experimental results. The Examples and Comparative Examples were configured identically except that the configurations related to the bead fixing layer and the bead spacer were different.

  Specifically, in Example 1, the base materials 10 and 15 had a thickness of 100 μm, and a COP film material provided with hard coat layers on both sides was applied. In Example 1, an ITO film having a thickness of 20 nm was formed on each of the base materials 10 and 15 by a sputtering method, and electrodes 11 and 16 were produced. Further, in Example 1, a predetermined coating solution in which a bead spacer was mixed was applied by spin coating, dried, and then fired to prepare bead fixing layers 12 and 17. As shown in Table 1, this coating solution is applied with a spherical bead spacer having a diameter of 5.3 μm, and the bead spacer, resin component, and solvent are mixed in a mass ratio of 0.02%, 5.24%, 75 Made by mixing at 70%. The resin component is an epoxy photosensitive resin, and the solvent is PEGMEA (propylene glycol monomethyl ether acetate). The firing process was performed at a temperature of 120 degrees for 30 minutes. In Example 1, the bead fixing layers 12 and 17 have a film thickness of 0.5 μm. This film thickness is an estimated film thickness according to the composition ratio in Table 1.

  In Example 1, the coating layers were then applied, dried and cured, and the alignment layers 14 and 19 were disposed. In addition, the coating liquid applied Nissan Chemical Industries, the alignment film material for vertical liquid crystal modes with the dry film thickness of 100 nm. Drying was performed at a temperature of 120 ° C. for 10 minutes. This was rubbed to perform alignment treatment. Since the bead spacer was buried and fixed in the bead fixing layer, it was confirmed that the bead spacer stayed at the formation position without moving even in the rubbing process. Thus, Example 1 produced an upper laminate and a lower laminate.

  Subsequently, in Example 1, after using a dispenser to arrange a sealing material in a frame shape on the lower laminate, a liquid crystal material was arranged by a dropping injection method to manufacture a light control film. Here, MLC2166 manufactured by Merck Ltd. was applied to the liquid crystal layer 8. For the sealing material 23, World Rock HRJ-40 manufactured by Kyoritsu Chemical Industry Co., Ltd. was applied.

  In Example 2, a light control film was produced in the same manner as in Example 1 except that the coating liquids related to the bead fixing layers 12 and 17 were different. Here, this coating solution uses the same bead spacer, resin component, and solvent as in Example 1, and the bead spacer, resin component, and solvent are in a mass ratio of 0.02%, 2.86%, and 87.60. % And mixed. In Example 2, the bead fixing layers 12 and 17 have a film thickness of 0.25 μm. This film thickness is an estimated film thickness according to the composition ratio (% by mass) in Table 1.

  In Comparative Example 1, a light control film was produced in the same manner as in Examples 1 and 2 except that the configuration related to the coating solution related to the bead fixing layer was different. Specifically, the electrodes 11 and 16 were produced on the base materials 10 and 15 by the same process as in Examples 1 and 2. Thereafter, using the resin component and the solvent related to the bead fixing layer of Examples 1 and 2, a coating liquid was produced at a mass ratio of 10% and 90%, and this coating liquid was the same as in Examples 1 and 2. Coating, drying, and baking were performed according to the conditions, and a bead fixing layer in which no bead spacer was arranged was manufactured.

  In Comparative Example 1, after the alignment layer was manufactured on the bead fixing layer, the same bead spacers used in Examples 1 and 2 were dispersed and arranged in the lower laminate. In Comparative Example 1, a dimming film was produced by laminating and integrating the thus prepared upper laminate and lower laminate in the same manner as in Examples 1 and 2.

  In the comparative example, when the liquid crystal material is spread by the dropping injection method, the dispersed bead spacers move together with the liquid crystal material, so that the bead spacers are arranged biased to the periphery of the liquid crystal layer, and the liquid crystal The layer could not be produced with a uniform thickness.

  However, in Examples 1 and 2, when the liquid crystal material is arranged by the dropping injection method to spread the liquid crystal material, the bead spacer can be prevented from moving, thereby preventing the bead spacer from being biased. The liquid crystal layer could be manufactured with a uniform thickness over the entire surface.

[Other Embodiments]
The specific configuration suitable for the implementation of the present invention has been described in detail above, but the present invention can be variously combined or modified without departing from the spirit of the present invention.

  That is, in the above-described embodiment, the case where the liquid crystal layer is driven by the VA method has been described. However, the present invention is not limited to this, and can be applied to the case where the liquid crystal layer is driven by the TN method. It can also be widely applied to.

  Moreover, although the case where the light control film was manufactured by single domain was described in the above-mentioned embodiment, this invention is not limited to this, It can apply widely also when manufacturing by multi domain. In addition, in this multi-domain, it may be made multi-domain by setting the alignment regulating force related to the pretilt by changing the irradiation direction by obliquely irradiating the ultraviolet rays used for forming the alignment layers 14 and 19. .

DESCRIPTION OF SYMBOLS 1 Light control film 2, 3 Linearly polarizing plate 4 Liquid crystal cell 5 Lower side laminated body (1st laminated body)
6 Upper laminate (second laminate)
8 Liquid crystal layer 8A Liquid crystal material 10, 15 Base material 11, 16 Transparent electrode 12, 17 Bead fixing layer 13, 18 Bead spacer 14, 19 Alignment layer 23 Sealing material

Claims (7)

In the light control film that sandwiches the liquid crystal layer between the first and second laminates and controls the transmitted light by controlling the orientation of the liquid crystal molecules related to the liquid crystal layer,
The first laminate is
A first transparent electrode, a first bead fixing layer, and a first alignment layer are provided on a first substrate,
The second laminate is
A second transparent electrode, a second bead fixing layer, a second alignment layer are provided on the second substrate,
At least the first laminate is
A light control film comprising a first bead spacer embedded in a first bead fixing layer. The second laminate is
The light control film according to claim 1, further comprising a second bead spacer embedded in the second bead fixing layer. The first and second bead fixing layers are:
The light control film of Claim 1 or Claim 2 whose refractive index is 1.55 or more and 1.65 or less. The first and second bead fixing layers are:
The light control film according to claim 1, wherein the volume resistivity is 1 × 10 ¹⁰ Ω · cm or less. The first and second bead fixing layers are:
The light control film according to claim 1, wherein the volume resistivity is 1 × 10 ⁸ Ω · cm or more. In the method of manufacturing a light control film, the liquid crystal layer is sandwiched between the first and second laminates, and the alignment of liquid crystal molecules related to the liquid crystal layer is controlled to control transmitted light.
A first laminate manufacturing process for manufacturing the first laminate;
A second laminate manufacturing process for manufacturing the second laminate,
The first laminate manufacturing process includes:
A first transparent electrode manufacturing process for manufacturing a first transparent electrode on a first substrate;
A first bead fixing layer manufacturing step for manufacturing a first bead fixing layer on the first transparent electrode;
A first alignment layer manufacturing step of manufacturing a first alignment layer on the first bead fixing layer,
The second laminate manufacturing process includes:
A second transparent electrode manufacturing process for manufacturing a second transparent electrode on the second substrate;
A second bead fixing layer manufacturing step of manufacturing a second bead fixing layer on the second transparent electrode;
A second alignment layer manufacturing step of manufacturing a second alignment layer on the second bead fixing layer,
The first bead fixing layer manufacturing process includes:
Manufacturing process of light control film which coats the coating liquid of said 1st bead fixing layer containing 1st bead spacer, and manufactures said 1st bead fixing layer by which said 1st bead spacer is buried . The manufacturing process of the light control film of Claim 6 provided with the liquid crystal cell control process which presses and spreads the dripped liquid crystal material with the said 1st and 2nd laminated body, and manufactures a liquid crystal cell.

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