JP6665661B2 - Light control film, method for manufacturing light control film - Google Patents

Description

    The present invention relates to a light control film that is attached to a window of a passenger car and controls transmission of extraneous light.

  Conventionally, various proposals have been made on light control films that are attached to windows, for example, to control the transmission of extraneous light (Patent Documents 1 and 2). One of such light control films uses a liquid crystal. A light control film using this liquid crystal is produced by sandwiching a liquid crystal material with a transparent film material for which a transparent electrode has been fabricated to produce a liquid crystal cell, and sandwiching the liquid crystal cell with a linear polarizing plate. Thus, in this light control film, the orientation of the liquid crystal is varied by varying the electric field applied to the liquid crystal, thereby blocking or transmitting extraneous light, and further varying the amount of transmitted light. Control.

  For driving a liquid crystal cell in such a light control film, various driving methods proposed for a liquid crystal display panel can be applied. Specifically, a driving method such as a TN (Twisted Nematic) method, an IPS (In-Place-Switching) method, a VA (Virtual Alignment) method, or the like can be applied.

  In addition, various proposals have been made for liquid crystal display panels to improve the viewing angle characteristics by making the liquid crystal display panel multi-domain. Patent Document 3 discloses that an alignment layer is manufactured by providing ribs such as linear projections and dot projections. A multi-domain vertical alignment (MVA) has been proposed.

  Here, the VA method is a method in which the transmitted light is controlled by changing the orientation of the liquid crystal between a vertical orientation and a horizontal orientation. In general, when no electric field is applied, the liquid crystal layer is vertically oriented by vertically aligning the liquid crystal. A liquid crystal cell is configured to be sandwiched by the layers, and is configured to horizontally align the liquid crystal material by applying an electric field. Here, the multi-domain system is a system in which a plurality of regions (domains) having different behaviors of liquid crystal molecules with respect to the change of the electric field are provided. Applied to improve angular properties.

  By the way, the light control film is expected to be used for various applications due to its large area, for example, being attached to a window glass or the like. Therefore, it is desired that the device can be manufactured with a simple configuration. In addition, in the case of being used by attaching to a window glass, it is expected that the incident light may be sufficiently shielded because it may be expected to take on the function of a curtain. It is conceivable that these are driven by the VA single-domain system.

  However, in the single domain system of the VA system, there is a problem that the light control film is visually perceived as having a yellow tint, thereby deteriorating the tint of the light control film. Further, in the intermediate gradation, there is a problem that the gradation changes due to a change in the viewing direction according to the change in the viewing angle, and thus the viewing angle characteristic is significantly deteriorated in the intermediate gradation. If these problems can be solved, it is considered that the characteristics can be further improved by applying the present invention to a multi-domain system based on the VA system and further to a light control film based on a system other than the VA system.

JP-A-03-47392 JP-A-08-184273 JP-A-11-242225

  The present invention has been made in view of such a situation, and for example, in a light control film of a single-domain system of a VA system, it is possible to improve deterioration of tint and deterioration of a viewing angle characteristic in an intermediate gradation.

  The inventors of the present invention have made intensive studies to solve the above-mentioned problems, came up with the idea of changing the thickness of the liquid crystal layer by patterning the cell gap, and have completed the present invention.

  Specifically, the present invention provides the following.

(1) A liquid crystal layer is sandwiched between first and second laminates having at least an alignment layer, and alignment of the liquid crystal in the liquid crystal layer is driven by electrodes provided on the first and / or second laminates. In the light control film that controls the transmitted light by controlling the
First and second regions having different thicknesses are provided in the liquid crystal layer by disposing two or more types of spacers having a thickness difference value of 0.1 μm or more and 0.6 μm or less in the thickness direction of the liquid crystal layer. Light control film.

  According to (1), the cell gap is patterned by the first and second regions having different thicknesses to form the liquid crystal layer, and the thickness of the liquid crystal layer can be changed. This makes it possible to average the optical characteristics of the first and second regions having different thicknesses, thereby improving the deterioration of the tint and the deterioration of the viewing angle characteristics in the intermediate gradation.

(2) In (1),
The light control film, wherein the first and second regions are band-shaped regions.

  According to (2), it is possible to improve deterioration of tint and deterioration of viewing angle characteristics in an intermediate gradation by a specific configuration.

(3) In (1) or (2),
A light control film, wherein the spacer is a bead spacer.

(4) In (1) or (2),
A light control film, wherein the spacer is a columnar spacer made of a photoresist.

  According to (3) or (4), by applying a bead spacer or by applying a spacer made of a photoresist, it is possible to improve the deterioration of color and the deterioration of the viewing angle characteristic in intermediate gradation.

(5) In (1) or (2), the spacer is a bead spacer provided in the first laminate,
A Vickers hardness value B of a portion of the second laminate to which the bead spacer comes into contact is 11.8 or more and 35.9 or less;
In a state where the first laminate is viewed in a plan view, a multiplication value A × B of the occupancy A which is a ratio of an area occupied by the bead spacers on the first laminate and the Vickers hardness value B is: A light control film of 0.42 or more.

  According to (5), since the Vickers hardness value B is not less than 11.8 and not more than 35.9, it is possible to reduce the situation where the bead spacer penetrates into the opposing surface due to the pressing force during use or the like. Nonuniform cell gaps and local alignment defects can be reduced, and leakage of liquid crystal material can be effectively avoided. Further, since the multiplication value A × B of the occupancy A and the Vickers hardness value B is 0.42 or more, the Vickers hardness value B is set to be large when the occupancy A is small, and the bead spacer is set. The cell gap can be maintained by the hardness B corresponding to the stress concentration on the substrate, thereby making the cell gap non-uniform, reducing local alignment defects, and effectively avoiding leakage of liquid crystal material. Can be. As a result, the reliability of the bead spacer can be further improved as compared with the related art.

(6) a first laminate production step of producing at least an orientation layer on a first substrate made of a transparent film material to produce a first laminate;
A second laminate production step of producing at least an orientation layer on a second substrate made of a transparent film material to produce a second laminate,
Laminating a liquid crystal cell in which a liquid crystal layer is sandwiched between the first and second laminates.
The first laminate manufacturing step includes:
At least a first region where the first spacer is arranged and a second region where only the second spacer having a thickness smaller than the first spacer by 0.1 μm or more and 0.6 μm or less in the thickness direction of the liquid crystal layer is arranged. A method for manufacturing a light control film, comprising a spacer disposing step of forming a region on the first base material.

  According to (6), the liquid crystal layer can be formed by patterning the cell gap by the first and second regions having different thicknesses, and the thickness of the liquid crystal layer can be changed. This makes it possible to average the optical characteristics of the first and second regions having different thicknesses, thereby improving the deterioration of the tint and the deterioration of the viewing angle characteristics in the intermediate gradation.

(7) In (6),
The first and second spacers are bead spacers,
The spacer arrangement step,
Disposing a mask having an opening corresponding to the first region on the first base material and spraying the first spacer;
A light control film that forms a first region in which the first spacer is disposed and a second region in which only the second spacer is disposed.

  According to (7), after the first spacer is sprayed or before the first spacer is sprayed, the second spacer is sprayed on the entire surface, or the mask is provided with an opening corresponding to the second region. The first and second regions can be formed by dispersing the second spacer by using the above.

  ADVANTAGE OF THE INVENTION According to this invention, in the light control film by the VA single-domain system, for example, it is possible to improve the deterioration of the color tone and the deterioration of the viewing angle characteristic in the intermediate gradation.

It is a figure showing the light control film concerning a 1st embodiment of the present invention. FIG. 2 is a diagram for describing first and second regions in the light control film of FIG. 1. FIG. 4 is a diagram provided for explanation of optical characteristics. 2 is a flowchart illustrating a manufacturing process of the light control film of FIG. 1. It is a flowchart which shows the manufacturing process of an upper laminated body. It is a flowchart which shows the manufacturing process of a lower laminated body. It is a figure offered to explanation of a manufacturing process of a lower layered product. It is a figure offered to explanation of a manufacturing process by other examples of a lower layered product. FIG. 9 is a diagram for explaining a manufacturing process of a lower laminate according to another example different from FIG. 8;

[First Embodiment]
[Light control film]
FIG. 1 is a cross-sectional view for explaining a light control film according to the first embodiment of the present invention. The light control film 1 is used by attaching an adhesive layer or the like to a light control portion such as a window glass of a building, a showcase, an indoor transparent partition, and the like, and the amount of transmitted light is changed by changing an 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 a 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 stretching to form an optical function layer that performs an optical function as a linear polarizing plate. It is manufactured by sandwiching the optical functional layer between base materials made of a transparent film material such as described above. The linear 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 Nicols arrangement. The linear polarizing plates 2 and 3 may be so-called E-type coating linear polarizing plates. The linear polarizing plate 3 is provided with a retardation film 3A for optical compensation on the liquid crystal cell 4 side, but the retardation film 3A may be omitted as necessary. As the retardation film 3A, a biaxially stretched transparent film material such as a COP film material can be used.

  The liquid crystal cell 4 controls the polarization plane of the transmitted light by applying a voltage to a transparent electrode described later. Thereby, the light control film 1 is configured so that transmitted light can be controlled to achieve various light control.

(Liquid crystal cell)
The liquid crystal cell 4 is configured by sandwiching a liquid crystal layer 8 between a lower laminate 5 and an upper laminate 6 which are first and second laminates having a film shape. The lower laminate 5 is manufactured by arranging a transparent electrode 11, an alignment layer 12, and first and second spacers 13A and 13B on a substrate 10 made of a transparent film material. The upper laminate 6 is manufactured by disposing a transparent electrode 16 and an orientation layer 17 on a base material 15 made of a transparent film material. The liquid crystal cell 4 controls the alignment of the liquid crystal material provided on the liquid crystal layer 8 by the VA single-domain method by driving the transparent electrodes 11 and 16 provided on the lower laminate 5 and the upper laminate 6. This controls the plane of polarization of the transmitted light.

  Although various transparent film materials applicable to this kind of film material can be applied to the substrates 10 and 15, it is desirable to use a film material having small optical anisotropy. In this embodiment, a transparent film material having the same material and the same thickness is applied to the substrates 10 and 15, 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 can use various kinds of electrode materials applied to this kind of film material. In this embodiment, the transparent electrodes 11 and 16 are formed of a transparent electrode material made of ITO (Indium Tin Oxide).

  The alignment layers 12 and 17 are formed by a photo alignment layer. Here, as the photo-alignment material applicable to the photo-alignment layer, various materials to which a photo-alignment method can be applied can be widely applied. In this embodiment, for example, a photo-dimerization type material is used. . Regarding this photodimerization type material, “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) ". Note that the alignment layers 12 and 17 may be manufactured by manufacturing a resin layer of polyimide or the like instead of the optical alignment layer, and rubbing the resin layer. Alternatively, the alignment layer may be manufactured by shaping a line-shaped fine unevenness by rubbing.

  The first and second spacers 13A and 13B are provided to regulate the thickness of the liquid crystal layer 8, and a so-called bead spacer is applied in this embodiment. Various configurations such as a bead spacer made of an organic material and a bead spacer made of an inorganic material can be applied to the first and second spacers 13A and 13B. In this embodiment, the first and second spacers 13A and 13B have a spherical configuration, but may have a rod-like (rod-like) configuration such as a columnar or prismatic configuration.

  The first and second spacers 13A and 13B may be manufactured by applying a photoresist, exposing, and developing. In this case, the first and second spacers 13A and 13B are manufactured in a column shape, a truncated cone shape, a truncated pyramid shape, or the like having a cylindrical shape, a prism shape, or the like.

  As the liquid crystal layer 8, various liquid crystal materials applicable to this kind of light control film can be widely applied. Specifically, for example, a liquid crystal compound described in JP-A-2003-366484 can be used for the liquid crystal layer 8. As a commercially available product, for example, a liquid crystal material such as MLC2166 manufactured by Merck can be used. In the case of the guest-host system, the liquid crystal layer 8 is mixed with a liquid crystal material and a dye for light control, but a mixture of a liquid crystal material and a dye proposed for the guest-host system can also be widely applied. it can. In the liquid crystal cell 4, a sealing material is disposed so as to surround the liquid crystal layer 8, and the lower laminated body 5 and the upper laminated body 6 are integrally held by the sealing material, thereby preventing leakage of the liquid crystal material. As the sealing material, for example, a thermosetting resin made of an epoxy resin, an ultraviolet curable resin made of an acrylic resin, a cured resin cured by heat and ultraviolet, or the like is used.

[Patterning of cell gap]
The first and second spacers 13A and 13B are spacers for manufacturing cell gaps having different sizes, and in this embodiment, are bead spacers having different diameters. In the light control film 1, the cell gap is patterned by the arrangement of the first and second spacers 13A and 13B, and the thickness of the liquid crystal layer 8 is changed in the in-plane direction of the liquid crystal layer 8. Thus, in the light control film 1, the portions having different thicknesses are closely arranged in the liquid crystal layer 8, and the tint of transmitted light by the portions having different thicknesses is averaged, thereby preventing color deterioration. I do. Also, the change in the gradation due to the change in the viewing angle is averaged, thereby preventing the deterioration of the viewing angle characteristic in the intermediate gradation.

  That is, FIG. 2 is a diagram provided for explaining the patterning of the cell gap. The second spacer 13B has a smaller diameter than the first spacer 13A. As shown in FIG. 2A, the light control film 1 includes a second region AR2 in which only the small-diameter second spacer 13B is disposed and a first region in which the first spacer 13A is disposed. AR1 is provided. In this embodiment, in the first region AR1, the first spacer 13A and the second spacer 13B are provided so as to be mixed, but only the first spacer 13A may be provided. In this embodiment, the first and second regions AR1 and AR2 are formed by band-shaped regions.

  In the case where the second region AR2 in which only the second spacer 13B having a small diameter is provided and the first region AR1 in which the first spacer 13A having a large diameter is provided, the light control film 1 is used. In FIG. 2B, the substrates 10 and 15 made of a transparent film material having a small thickness and sufficient flexibility are held so as to face each other by a cell gap determined by the size of the spacers 13A and 13B. As shown in ()), the substrates 10 and / or 15 bend, the size of the cell gap changes in the in-plane direction so as to correspond to the spacers 13A and 13B, and the thickness of the liquid crystal layer 8 is modulated in the in-plane direction. Will be.

  Thus, in the light control film 1, the first region AR1 in which the cell gap is set in the diameter DA of the first spacer 13A, and the second region AR2 in which the cell gap is set in the diameter DB of the second spacer 13B. Are sequentially and alternately formed.

  Here, when the first and second regions AR1 and AR2 are manufactured to be sufficiently narrow, the optical characteristics of the first and second regions AR1 and AR2 are averaged and perceived. It is possible to prevent deterioration of color and deterioration of viewing angle characteristics. On the other hand, when the width and the repetition pitch of the first and second regions AR1 and AR2 are large, it is difficult to sufficiently average and perceive the optical characteristics of the first and second regions AR1 and AR2. . This makes it difficult to sufficiently prevent color deterioration, and also difficult to sufficiently prevent viewing angle characteristic deterioration. Accordingly, it is desired that the first and second regions AR1 and AR2 are manufactured to be sufficiently narrow. However, when the width of the first and second regions AR1 and AR2 and the repetition pitch P are reduced, the first and second regions AR1 and AR2 are reduced. In the second regions AR1 and AR2, it is difficult to sufficiently deform the base materials 10 and 15, whereby the cell gap varies and stable optical characteristics cannot be secured.

  Therefore, in this embodiment, the repetition pitch P of the first and second regions AR1 and AR2 is set to 300 μm or more and 1500 μm or less, and preferably 500 μm or more and 1000 μm or less. Further, the width of the first and second regions AR1 and AR2 in the direction of the repetition pitch P is set to 150 μm or more and 1000 μm or less, preferably 250 μm or more and 750 μm or less.

  In this way, as the substrates 10 and 15 made of the transparent film material are bent and the size of the cell gap changes in the in-plane direction so as to correspond to the spacers 13A and 13B, the first and second regions AR1 and AR2 are formed. In the above, although the base materials 10 and 15 can be easily deformed by manufacturing with a band-shaped region, various shapes such as a rectangular shape and a triangular shape are applied to the first and second regions AR1 and AR2. be able to.

  Further, from the viewpoint of accurately setting the first and second regions AR1 and AR2 to the thicknesses corresponding to the spacers 13A and 13B by the deformation of the base materials 10 and 15 in this manner, the spacers 13A and 13B have a difference in thickness. It is desirable that the difference between the thicknesses is 0.1 μm or more and 0.6 μm or less, preferably the thickness difference value is 0.2 μm or more and 0.4 μm or less. By setting the thickness in such a range, it is possible to set so as to satisfy the conditions described later, and to further improve the reliability of the bead spacer as compared with the related art. Here, the difference value of the spacer thickness is a difference between the heights of two or more types of spacers arranged in the liquid crystal layer 8 in the thickness direction. In the case of a bead spacer, the sphere conversion between the spacers 13A and 13B is used. Is the difference between the diameters (marked by arrows in FIG. 1). As a result, the thickness of the liquid crystal layer 8 changes as a result.

  In addition, the first and second regions AR1 and AR2 may be formed by band-like regions as described above, and the boundary and / or the entire region may be meandered, whereby the regularity is relaxed and interference fringes are generated. Can be prevented. Further, the first and second regions AR1 and AR2 have a repetition pitch P, a width of the first region AR1, and a width of the second region AR2 in the repetition direction of the first and second regions AR1 and AR2. The parts or all may be changed regularly or irregularly. With such a change, it is possible to prevent the occurrence of interference fringes due to the regularity of the first and second regions AR1 and AR2.

  Further, in the light control film 1, the first and second spacers 13A and 13B are arranged at random, which also relaxes the regularity caused by providing the first and second regions AR1 and AR2 sequentially and alternately. The occurrence of interference fringes and the like can be prevented.

〔simulation result〕
FIG. 3 is a characteristic curve diagram used for confirmation when the first and second regions AR1 and AR2 are sequentially and alternately provided by the arrangement of the first and second spacers 13A and 13B. In FIG. 3, symbols L1, L2, and L3 are simulation results when only spacers having a diameter of 3.5 μm, a diameter of 3.7 μm, and a diameter of 3.8 μm are arranged. These simulation results show that when the cell gap is increased by increasing the diameter of the spacer, the transmittance gradually increases on the long wavelength side (wavelength 500 nm or more) of the visible light region.

  On the other hand, symbols L4 and L5 are simulation results of the light control film of this embodiment. Reference symbol L4 indicates the first and second regions AR1 and AR2 using the spacers 13A and 13B having a diameter of 3.7 μm and a diameter of 3.5 μm (the thickness difference in the thickness direction of the liquid crystal layer is 0.2 μm). Is set to 8: 2. Reference symbol L5 indicates a case where the widths of the first and second regions AR1 and AR2 are set to 6: 4 using the spacers 13A and 13B having a diameter of 3.7 μm and a diameter of 3.5 μm. In the simulation results L4 and L5, the repetition pitch P of the first and second regions is 1000 μm.

  The simulation results of symbols L4 and L5 are the characteristics between the simulation results L1 and L2 as compared with the simulation results L1 and L2 when only the spacers having a diameter of 3.5 μm and 3.7 μm are arranged. It can be seen that the transmittance can be ensured by the characteristics according to the ratio of the width of the second regions AR1 and AR2, and the deterioration of the tint can be prevented. Further, it can be seen that the deterioration of the tint can be prevented in this way, so that the deterioration of the viewing angle characteristic in the intermediate gradation can also be prevented.

[Detailed configuration of bead spacer]
Here, in this embodiment, the bead spacers 13A and 13B are arranged on the lower laminate 5 to manufacture a light control film, and the Vickers hardness value of the portion of the upper laminate 6 where the bead spacers 13A and 13B come into contact with each other. B is set so as to be 11.8 or more and 35.9 or less, and the multiplication value A × B of the occupancy A of the bead spacers 13A and 13B and the Vickers hardness value B is set to be 0.42 or more. Is done. Here, the occupancy A is a ratio of the area of the bead spacers 13A and 13B to the area of the lower laminate 5 when the lower laminate 5 is viewed in a plan view (when viewed from the vertical direction). Thereby, in this embodiment, the reliability of the bead spacer is further improved as compared with the related art. In addition, the value of Vickers hardness is a measured value under the conditions described in the following examples.

  That is, when the Vickers hardness value B of the portion of the second laminate where the tips of the bead spacers 13A and 13B abut is less than 11.8, the pressing force during use causes the tips of the bead spacers 13A and 13B to face each other. As a result, the cell gap becomes non-uniform, or local alignment defects occur. If the Vickers hardness value B of the portion exceeds 35.9, cracks occur when the whole is bent.

  When the multiplication value A × B with the Vickers hardness value B is less than 0.42, the tips of the bead spacers 13A and 13B penetrate into the opposing surfaces, and as a result, the cell gap becomes uneven, Poor alignment occurs.

  However, the Vickers hardness value B of the portion of the upper laminated body 6 where the bead spacers 13A and 13B are in contact is 11.8 or more and 35.9 or less, and the multiplication value A × B of the occupancy A and the Vickers hardness value B is equal to 0. If the number is set to 42 or more, these problems can be solved at once and the reliability of the bead spacer can be further improved as compared with the related art.

  That is, if the Vickers hardness value B at the portion of the upper laminate 6 where the bead spacers 13A and 13B come into contact is 11.8 to 35.9, the tips of the bead spacers 13A and 13B face each other due to the pressing force during use. It is possible not to penetrate the surface, and it is possible to prevent the occurrence of cracks. Further, since the multiplication value A × B of the occupancy A and the Vickers hardness B is 0.42 or more, if the occupancy A is small, the Vickers hardness B is set so as to be large. The cell gap can be maintained by the hardness B according to the concentration of stress on the spacer, thereby making the cell gap non-uniformity and local alignment defects more reliably, and effectively preventing the leakage of the liquid crystal material. Can be avoided. As a result, the reliability of the bead spacer can be further improved as compared with the related art.

  When the thickness of the liquid crystal layer is patterned by arranging the bead spacers 13A and 13B having different sizes as described above, if the sizes of the bead spacers 13A and 13B differ greatly, the above-described Vickers hardness value B is multiplied. The condition of the value A × B cannot be applied. However, in the case where the above-mentioned difference value between the repetition pitch P of the first and second regions AR1 and AR2, the width of the first and second regions AR1 and AR2, and the thickness of the spacers 13A and 13B is set, it is sufficient. By applying the above-described conditions of the Vickers hardness value B and the multiplication value A × B, the reliability of the bead spacer can be further improved as compared with the related art.

〔Test results〕
Table 1 is a chart showing the test results used to confirm the configuration of the bead spacer. The examples and comparative examples in Table 1 have the same configuration except that the configurations of the bead spacer and the alignment layer with which the bead spacer abuts are different. More specifically, in the light control films of these examples and comparative examples, bead spacers were provided only on the lower laminate 5, and the occupation ratio A was varied depending on the selection of the size of the bead spacers and the application amount. Further, the Vickers hardness value B of the portion of the second laminate where the tip of the bead spacer comes into contact was set according to the conditions when the alignment layer 23A was manufactured.

  That is, the bead spacer is coated on the electrode 22B by applying a coating liquid prepared by dispersing the bead spacer in a solvent together with a resin component by spin coating, followed by drying, curing by ultraviolet irradiation, and firing. A bead spacer is randomly and difficult to move. The occupancy rate of the bead spacer is adjusted by adjusting the amount of the bead spacer to be charged into the coating liquid and the coating film thickness of the coating liquid.

In Examples and Comparative Examples, the density of the bead spacer was set to 40 beads / mm ² , 50 beads / mm ² , and 100 beads / mm ² , and a spherical shape having a diameter of 3 μm or 6 μm was applied to the bead spacer. . Thus, the lower laminate 5 was manufactured with the occupation ratio A being 0.028%, 0.035%, 0.071%, 0.113%, and 0.141%. As the bead spacer 24, Micropearl EX series manufactured by Sekisui Chemical Co., Ltd. was applied.

  The base material 21B is a COP (cycloolefin polymer) film having a thickness of 100 μm and having a hard coat layer. The electrode 22B was manufactured with a thickness of 20 nm.

  The alignment layer 23B was manufactured by applying a coating liquid so as to have a dry film thickness of 100 nm, followed by heat curing.

  On the other hand, similarly to the orientation layer 23B, the orientation layer 23A of the upper laminate 6, which is the surface in contact with the bead spacer, is subjected to the thermosetting conditions (heating temperature, Vickers hardness value B was set by setting (heating time) and the like. Thus, in Examples and Comparative Examples, upper laminates 6 having Vickers hardness values B of 10.2, 11.8, 35.9, and 38.5 were produced (Table 3). The hardness B is determined by setting the conditions for forming the alignment layer 23A and manufacturing the upper laminate 6 having different hardnesses for the alignment layer 23A. It is the measured value measured by The measurement result is a measurement result obtained by measuring 12 points and averaging the remaining 10 points excluding the maximum value and the minimum value.

  The Vickers hardness value B was measured using a PICODENTOR HM500 manufactured by Helmut Fisher. The measurement was performed under the conditions of a pushing speed of 300 mN / 20 sec, a release speed of 300 mN / 20 sec, a creep time of 5 seconds, and a maximum load of 100 mN.

  In addition, the base material 21A and the electrode 22A of the upper laminate were configured the same as the base material 21B and the electrode 22B of the lower laminate 13. The alignment layer 23A was configured the same as the alignment layer 23B except that the hardness B was adjusted.

In each of Examples and Comparative Examples in Tables 1 and 2, a light control film was manufactured and tested using the upper laminate 6 and the lower laminate 5 thus manufactured. In the test shown in Table 1, a load of 1 kg / cm ² was applied for 1 minute while the light control film was placed on a smooth surface having high hardness by the surface plate, and then the liquid crystal cell was driven to determine a decrease in the cell gap. did. After the weight was applied in this manner, the upper laminate and the lower laminate were peeled off, and a portion where the bead spacer was in contact was observed with a microscope to observe penetration of the tip of the bead spacer.

  Here, when the portion where the bead spacers 13A and 13B are in contact with each other is obliquely observed using a technique such as SEM, when a dent (recess) is confirmed, “film penetration” is determined to be “×”, and when a recess is not recognized. , “Film penetration” was judged as “○”.

  In addition, in the state of the light control film, the film was wound around a cylindrical mandrel having a diameter of 2 mm according to the specifications of the bending test of JIS K5600-5-1, and occurrence of cracks was confirmed. If cracks were found on the substrate in more than half of the samples in this test, `` cracks '' are indicated by `` x '', and conversely, in more than half of the samples, cracks were found on the substrates. When the occurrence is not confirmed, “crack” is indicated by “○”.

  According to the measurement results in Table 1, the Vickers hardness value B of the portion of the second laminated body where the bead spacers 13A and 13B are in contact is 11.8 or more and 35.9 or less. When the multiplication value A × B was 0.42 or more, it was confirmed that penetration of the film could be prevented and no cracks were generated, and it was confirmed that the reliability of the bead spacer could be sufficiently secured.

〔Manufacturing process〕
FIG. 4 is a flowchart for explaining a manufacturing process of the light control film 1. In this manufacturing process, the upper stacked body 6 and the lower stacked body 5 are manufactured in the upper stacked body manufacturing step SP2 and the lower stacked body manufacturing step SP3, respectively. Further, in the laminating step SP4, the light control film 1 is manufactured by laminating the upper laminate 6 and the lower laminate 5 with the liquid crystal layer 8 interposed therebetween and then integrating them with a sealant.

  FIG. 5 is a flowchart showing the upper layered body manufacturing step SP2 in detail. In the upper laminate manufacturing step SP2 (SP11), in the electrode manufacturing step SP12, a transparent electrode 16 made of ITO is manufactured on the base material 15 made of a transparent film material by sputtering or the like. In the subsequent alignment layer manufacturing step SP13, the coating liquid for the alignment layer 17 is applied and dried, and then cured by irradiation with ultraviolet light of linearly polarized light, thereby manufacturing the alignment layer 17.

  FIG. 6 is a flowchart showing the details of the lower laminate manufacturing step SP3. In the lower laminate manufacturing step SP3 (SP21), in the electrode manufacturing step SP22, the transparent electrode 11 made of ITO is manufactured by sputtering on the base material 10 made of a transparent film material. Subsequently, in this manufacturing process, in the alignment layer manufacturing process SP23, the coating liquid for the alignment layer 12 is applied, dried, and exposed to form the alignment layer 12.

  In this manufacturing process, in the subsequent small spacer disposing step SP24, the second spacer 13B on the smaller diameter side is disposed. Here, in this embodiment, the coating liquid in which the second spacer 13B is dispersed is sprayed onto the base material 10 on which the alignment layer 12 is manufactured, so that the second liquid is dried while the coating liquid is dried. Is lowered to the base material 10. Here, the component of the adhesive is added to the coating liquid in which the second spacer 13B is dispersed. When the second spacer 13B falls on the base material 10, the second spacer 13B is irradiated with ultraviolet rays and fired. The second spacer 13B is held at the lowered position by the added adhesive component. Thus, in this manufacturing process, as shown in FIG. 7A, the second spacers 13B are randomly arranged on the entire surface of the base material 10 on which the alignment layer 12 is manufactured.

  In this manufacturing process, in the subsequent large spacer disposing step SP25, the first spacer 13A having the larger diameter is disposed. In this embodiment, the first spacer 13B is formed by arranging a mask in which an opening is manufactured at a portion corresponding to the first region AR1 on the base material 10 on which the second spacers 13B are randomly arranged. Mask the area where is not placed. In this state, in this manufacturing process, as in the case of disposing the second spacer 13A, a coating liquid in which the first spacer 13A is dispersed is sprayed over the masked base material 10, and this coating is performed. The first spacer 13A is lowered onto the substrate 10 while drying the liquid. Here, the component of the adhesive is also added to the coating liquid in which the first spacer 13A is dispersed. As a result, when the first spacer 13A descends to the base material 10, the first spacer 13A moves to the descending position by the subsequent curing and firing. Will be retained. Thus, in this manufacturing process, as shown in FIG. 7B, the first spacers 13A are randomly arranged in the first region AR1.

  Various arrangements can be applied to the arrangement of the first and second spacers 13A and 13B.

  Specifically, only the first spacer 13A having a large diameter may be disposed using a mask. That is, for example, as shown in FIG. 8A, with the base material 10 masked, the first spacer 13A is applied only to the first region AR1 by spraying a coating liquid in which the first spacer 13A is dispersed. Deploy. Subsequently, as shown in FIG. 8B, the second spacer 13B is dispersed by spraying a coating liquid to cover the entire surface of the substrate 10 (in the first region AR1 and the second region AR2). Are scattered and randomly arranged. Thus, the first and second spacers 13A and 13B may be arranged.

  Further, as shown in FIG. 9 (A), the first spacer 13A is arranged only in the first region AR1 by spraying a coating liquid in which the first spacer 13A is dispersed in a state where the base material 10 is masked. I do. Subsequently, as shown in FIG. 9B, in a state where a mask having an opening manufactured only in the second area AR2 is arranged, the second area AR2 is sprayed with a coating liquid in which the second spacer 13B is dispersed. And the second spacers 13B are scattered and randomly arranged. Thereby, the first and second spacers 13A and 13B may be arranged.

  In this case, the first region AR1 may include the first and second spacers 13A and 13B, or may include only the first spacer 13A having a large diameter.

[Other embodiments]
As described above, the specific configuration suitable for carrying out the present invention has been described in detail. However, the present invention can combine the above-described embodiments without departing from the spirit of the present invention. Various changes can be made.

  That is, in the above embodiment, the case where a bead spacer is used has been described. However, the present invention is not limited to this, and can be widely applied to a case where a spacer is manufactured in a pillar shape by exposing and developing a photoresist.

  In the above-described embodiment, the case where the present invention is applied to a single-domain light control film based on the VA method has been described. Good. In this way, in the first place, when the deterioration of the tint and the deterioration of the viewing angle characteristic in the intermediate gradation are improved by the multi-domain, it is possible to further improve the deterioration of the tint and the deterioration of the viewing angle characteristic in the intermediate gradation. For example, optical characteristics when the number of domains is increased by a small number of domains can be secured.

  Further, in the above-described embodiment, the case where a light control film is adhered to an area where light control is to be performed by using an adhesive layer or the like has been described. However, the present invention is not limited thereto. The present invention can be widely applied to a case where the sheet is sandwiched between transparent members such as those described above and used in a laminated and integrated manner.

  In the above-described embodiment, the case where the present invention is applied to a single-domain light control film based on the VA method has been described. However, the present invention is not limited to this, and the TN method, the IPS method, the FFS method, etc. The present invention can be widely applied to a multi-domain light control film, a single-domain light control film using a TN method other than the VA method, an IPS method, an FFS method, or the like.

REFERENCE SIGNS LIST 1 light control film 2, 3 linear polarizing plate 3 A retardation film 4 liquid crystal cell 5 lower laminate (first laminate)
6 Upper laminate (second laminate)
8 Liquid crystal layer 10, 15 Base material 11, 16 Transparent electrode 12, 17 Alignment layer 13A, 13B Spacer

Claims (7)

A liquid crystal layer sandwiched by at least the orientation first laminate comprising comprises a layer and a second laminate, wherein the liquid crystal by the driving by the first stack and or the second transparent electrode provided on the laminate a light control film for controlling the transmitted light by controlling the alignment of the liquid crystal layer,
A first spacer, and a second spacer having a thickness smaller by 0.1 μm or more and 0.6 μm or less than the first spacer in a thickness direction of the liquid crystal layer,
A first region in which at least the first spacer is arranged, and a cell gap of the liquid crystal layer is adjusted to a thickness of the first spacer;
A light control film , comprising: a second region in which only the second spacer is disposed, and a second region in which a cell gap of the liquid crystal layer is adjusted to a thickness of the second spacer . The light control film according to claim 1, wherein the first region and the second region are band-shaped regions. The light control film according to claim 1 or 2, wherein the first spacer and the second spacer are bead spacers. The light control film according to claim 1 or 2, wherein the first spacer and the second spacer are columnar spacers made of photoresist. The first spacer and the second spacer are bead spacers provided on the first laminate,
A Vickers hardness value B of a portion of the second laminated body where the first spacer and the second spacer contact each other is 11.8 or more and 35.9 or less;
In a state where the first laminate is viewed in a plan view, a multiplication value A × B of the occupancy A which is a ratio of an area occupied by the bead spacers on the first laminate and the Vickers hardness value B is: The light control film according to claim 3 , which is 0.42 or more. A first laminate production step of producing at least an orientation layer on a first substrate made of a transparent film material to produce a first laminate,
A second laminate production step of producing at least an orientation layer on a second substrate made of a transparent film material to produce a second laminate,
Wherein a laminating step for producing a liquid crystal cell formed by sandwiching a liquid crystal layer by the first laminate and the second laminate,
The first laminate manufacturing step includes:
At least a first region where the first spacer is arranged and a second region where only the second spacer having a thickness smaller than the first spacer by 0.1 μm or more and 0.6 μm or less in the thickness direction of the liquid crystal layer is arranged. A method for producing a light control film, comprising a spacer disposing step of forming a region on the first base material. The first spacer and the second spacer is a bead spacer,
The spacer arrangement step,
Spraying the second spacer on the first substrate,
By placing a mask having an opening corresponding to the first region on the first substrate and the second spacer is sprayed, by spraying said first spacer, prior Symbol first method for producing a light control film of claim 6 to form a region, a front Stories second region.

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