JP2017198744A - Light control film, method for manufacturing light control film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a deterioration in hue and a deterioration in viewing angle characteristic in an intermediate gradation in a light control film of a VA system and a single domain system.SOLUTION: In a light control film 1 sandwiching a liquid crystal layer 8 with first and second laminates 5 and 6 including at least alignment layers 12 and 17, and controlling transmitted light by controlling the alignment of liquid crystal in the liquid crystal layer 8 through the drive of electrodes 11 and 16 provided in the first laminate 5 and/or the second laminate 6, arrangement of two types of spacers 13A and 13B having a value of difference in thickness of 0.1 μm or more and 0.6 μm or less provides first and second areas AR1 and AR2 having different thicknesses in the liquid crystal layer 8.SELECTED DRAWING: Figure 2

Description

    The present invention relates to a light control film that is attached to a window or the like of a passenger car to control the transmission of extraneous 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 is manufactured to produce a liquid crystal cell, and sandwiching 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.

  Various driving methods proposed for liquid crystal display panels can be applied to driving the liquid crystal cell in such a light control film. 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, liquid crystal display panels have been proposed in various ways to improve viewing angle characteristics by using multi-domains. In Patent Document 3, an alignment layer is manufactured by providing ribs such as linear protrusions and dotted protrusions. A multi-domain method (MVA: Multi-domain vertical alignment) based on VA has been proposed.

  Here, the VA method is a method of controlling the transmitted light by changing the alignment of the 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 being sandwiched between layers, and the liquid crystal material is horizontally aligned by application of an electric field. Here, the multi-domain method is a method in which a plurality of regions (domains) in which the behavior of liquid crystal molecules is different with respect to a variable electric field is provided. In general, the field of view is obtained by averaging (integrating) optical characteristics in a plurality of regions. Applied to improve angular characteristics.

  By the way, it is estimated that a light control film is affixed on a window glass etc., and is used for various uses by a large area. Therefore, it is desired that the product can be manufactured with a simple configuration. Moreover, when pasting on a window glass and using it, it is calculated | required that the function of a curtain is assumed, and it is calculated | required that incident light can fully be shielded. It is conceivable to drive with the single domain method of the VA method.

  However, in the VA single domain system, the light control film is visually recognized as yellowish, and this causes a problem that the color of the light control film deteriorates. Further, in the intermediate gradation, the gradation changes due to the change in the viewing direction according to the change in the viewing angle, and there is a problem that 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 to a multi-domain system using the VA system, for example, and further to a light control film using a system other than the VA system.

JP 03-47392 A Japanese Patent Laid-Open No. 08-184273 Japanese Patent Laid-Open No. 11-242225

  The present invention has been made in view of such a situation. For example, in a light-control film by a VA single-domain method, color tone deterioration and deterioration of viewing angle characteristics in intermediate gradation are improved.

  The present inventor has made extensive studies to solve the above problems, and has come up with the idea that the thickness of the liquid crystal layer is changed by patterning the cell gap, thereby completing the present invention.

  Specifically, the present invention provides the following.

(1) A liquid crystal layer is sandwiched between first and second stacked bodies each having at least an alignment layer, and liquid crystal alignment of the liquid crystal layer is driven by an electrode provided on the first and / or second stacked body. In the light control film that controls transmitted light by controlling
By arranging 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, first and second regions having different thicknesses are provided in the liquid crystal layer. Dimming 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. As a result, the optical characteristics of the first and second regions having different thicknesses can be averaged, and the deterioration of the tint and the viewing angle characteristics in the intermediate gradation can be improved.

(2) In (1),
The light control film whose said 1st and 2nd area | region is a strip-shaped area | region.

  According to (2), it is possible to improve the deterioration of the tint and the deterioration of the viewing angle characteristics in the intermediate gradation by the 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 applying a spacer by a photoresist, it is possible to improve the deterioration of the color tone and the deterioration of the viewing angle characteristics in intermediate gradation.

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

  According to (5), when the Vickers hardness value B is 11.8 or more and 35.9 or less, the situation in which the bead spacer penetrates into the opposing surface due to the pressing force during use, etc. is reduced. It is possible to reduce cell gap nonuniformity and local alignment failure, and to effectively avoid leakage of liquid crystal material. In addition, since the multiplication value A × B of the occupation ratio A and the Vickers hardness value B is 0.42 or more, when the occupation ratio A is small, the Vickers hardness value B is set to be large, and the bead spacer The cell gap can be maintained by the hardness B corresponding to the stress concentration on the substrate, thereby further reducing the cell gap non-uniformity, local alignment failure, and effectively avoiding the leakage of the liquid crystal material. Can do. By these, the reliability regarding a bead spacer can be improved further compared with the past.

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

  According to (6), the cell gap can be 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. As a result, the optical characteristics of the first and second regions having different thicknesses can be averaged, and the deterioration of the tint and the viewing angle characteristics in the intermediate gradation can be improved.

(7) In (6),
The first and second spacers are bead spacers;
The spacer arrangement step includes
A mask having an opening corresponding to the first region is disposed on the first base material, and the first spacer is dispersed.
The light control film which forms the 1st area | region which has arrange | positioned the said 1st spacer, and the 2nd area | region which has arrange | positioned only the said 2nd spacer.

  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 has an opening corresponding to the second region. The first and second regions can be formed by spraying the second spacers using.

  ADVANTAGE OF THE INVENTION According to this invention, in the light control film by a VA system single domain system, the deterioration of a color tone and the viewing angle characteristic in intermediate gradation can be improved, for example.

It is a figure which shows the light control film which concerns on 1st Embodiment of this invention. It is a figure where it uses for description of the 1st and 2nd area | region in the light control film of FIG. It is a figure where it uses for description of an optical characteristic. It is a flowchart which shows the manufacturing process of the light control film of FIG. 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 where it uses for description of the manufacturing process of a lower side laminated body. It is a figure where it uses for description of the manufacturing process by the other example of a lower laminated body. It is a figure where it uses for description of the manufacturing process of the lower laminated body by the other example different from FIG.

[First Embodiment]
[Light control film]
FIG. 1 is a cross-sectional view for explaining the 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 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. A biaxially stretched transparent film material such as a COP film material can be applied to the retardation film 3A.

  The liquid crystal cell 4 controls the polarization plane of transmitted light by an applied voltage to a transparent electrode described later. Thereby, the light control film 1 is comprised so that transmitted light can be controlled and various light control can be aimed at.

[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. The lower laminate 5 is manufactured by disposing a transparent electrode 11, an alignment layer 12, and first and second spacers 13A and 13B on a base material 10 made of a transparent film material. The upper laminate 6 is manufactured by arranging a transparent electrode 16 and an alignment 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 in the liquid crystal layer 8 by the VA single domain method by driving the transparent electrodes 11 and 16 provided in 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 base materials 10 and 15, it is desirable to apply a film material having a small optical anisotropy. 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.

  Various electrode materials applied to this kind of film material can be applied to the transparent electrodes 11 and 16, and 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 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). The alignment layers 12 and 17 may be manufactured by manufacturing a resin layer such as polyimide instead of the photo alignment layer and rubbing the resin layer. Further, the alignment layer may be manufactured by forming a line-shaped fine uneven shape by rubbing.

  The first and second spacers 13A and 13B are provided to define the thickness of the liquid crystal layer 8, and so-called bead spacers are 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 13 </ b> A and 13 </ b> B may have a rod-shaped (rod-shaped) configuration such as a cylindrical shape or a prismatic shape, although a spherical configuration is applied.

  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 columnar shape, a columnar shape such as a prismatic shape, a truncated cone shape, a truncated pyramid shape, or the like.

  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. In the liquid crystal cell 4, a sealing material is disposed so as to surround the liquid crystal layer 8, and the lower stacked body 5 and the upper stacked body 6 are integrally held by the sealing material, and leakage of the liquid crystal material is prevented. As the sealing material, for example, a thermosetting resin using an epoxy resin agent, an ultraviolet curable resin using an acrylic resin agent, a curable resin curable by heat and ultraviolet light, or the like is applied.

[Cell gap patterning]
The first and second spacers 13A and 13B are spacers for producing cell gaps having different sizes. In this embodiment, the spacers 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. Thereby, in the light control film 1, the site | part from which thickness differs is arrange | positioned closely in the liquid-crystal layer 8, and the deterioration of color is prevented by averaging the color of the transmitted light by this site | part with different thickness To do. In addition, the gradation change 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 for explaining cell gap patterning. 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 second spacer 13B having a small diameter is disposed, and a first region in which the first spacer 13A is disposed. AR1 is provided. Here, in this embodiment, although the first spacer 13A and the second spacer 13B are provided in the first region AR1, only the first spacer 13A may be provided. In this embodiment, the first and second regions AR1 and AR2 are formed by strip regions.

  Thus, when providing 2nd area | region AR2 in which only the 2nd spacer 13B which is small diameter is arrange | positioned, and 1st area | region AR1 in which the 1st spacer 13A which is large diameter is provided, the light control film 1 Then, the base materials 10 and 15 made of a transparent film material having a small thickness and sufficient flexibility are held so as to be opposed to each other by a cell gap determined by the size of the spacers 13A and 13B. ), The base material 10 and / or 15 is bent, 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.

  Thereby, in the light control film 1, 1st area | region AR1 in which the cell gap was set to the diameter DA of the 1st spacer 13A, and 2nd area | region AR2 to which the cell gap was set in diameter DB of the 2nd spacer 13B Are formed alternately.

  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 the deterioration of color and the viewing angle characteristics. On the other hand, when the width and the repetition pitch of the first and second regions AR1 and AR2 are increased, it becomes difficult to perceive the optical characteristics of the first and second regions AR1 and AR2 sufficiently averaged. . As a result, it becomes difficult to sufficiently prevent the deterioration of color, and it becomes difficult to sufficiently prevent the deterioration of viewing angle characteristics. As a result, it is desired that the first and second regions AR1 and AR2 be manufactured to be sufficiently narrow, but if the width and the repetition pitch P of the first and second regions AR1 and AR2 are reduced, the first and second regions AR1 and AR2 It becomes difficult to sufficiently deform the base materials 10 and 15 in the second regions AR1 and AR2, and thereby 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 to 1500 μm, preferably 500 μm to 1000 μm. The widths of the first and second regions AR1 and AR2 in the direction of the repetitive pitch P are set to 150 μm or more and 1000 μm or less, preferably 250 μm or more and 750 μm or less.

  Note that the first and second regions AR1 and AR2 can be obtained by changing the size of the cell gap in the in-plane direction so as to correspond to the spacers 13A and 13B by bending the base materials 10 and 15 using the transparent film material. In the first embodiment, the first and second regions AR1 and AR2 can be made of various shapes such as a rectangular shape and a triangular shape, although the substrate 10 and 15 can be easily deformed by being manufactured in the belt-like region. be able to.

  In addition, 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, the spacers 13A and 13B have a thickness difference value. It is desirable that the difference value of thickness is 0.1 μm or more and 0.6 μm or less, preferably 0.2 μm or more and 0.4 μm or less. By setting the thickness within such a range, the reliability of the bead spacer can be further improved as compared with the prior art by setting so as to satisfy the conditions described later. Here, the difference value of the spacer thickness is a difference in height in the thickness direction of two or more kinds of spacers arranged in the liquid crystal layer 8, and in the case of a bead spacer, a sphere conversion of the spacers 13A and 13B. Of the diameter (marked by an arrow in FIG. 1). As a result, the thickness of the liquid crystal layer 8 changes.

  In addition, the first and second regions AR1 and AR2 may be formed by band-like regions in this manner, and the boundary and / or the whole may meander, thereby relaxing regularity and generating interference fringes, etc. Can be prevented. Furthermore, the first and second regions AR1 and AR2 are one of the repetition pitch P, the width of the first region AR1, and the width of the second region AR2 in the repetition direction of the first and second regions AR1 and AR2. Parts or all of them may be changed regularly or irregularly. By changing in this way, 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 randomly arranged, and this also relaxes the regularity by sequentially providing the first and second regions AR1 and AR2. Generation 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 alternately provided in this manner by the arrangement of the first and second spacers 13A and 13B. In FIG. 3, reference numerals L1, L2, and L3 represent 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. From these simulation results, it is understood that when the cell gap is increased by increasing the diameter of the spacer, the transmittance gradually increases on the long wavelength side (wavelength of 500 nm or more) in the visible light region.

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

  The simulation results of the symbols L4 and L5 are the characteristics between the simulation results L1 and L2 with respect to the simulation results L1 and L2 when only the spacers having a diameter of 3.5 μm and a diameter of 3.7 μm are arranged. In addition, it can be seen that the transmittance can be ensured by the characteristic according to the ratio of the widths of the second regions AR1 and AR2, thereby preventing the deterioration of the color. Further, it can be seen that the deterioration of the viewing angle characteristic in the intermediate gradation can be prevented by preventing the deterioration of the tint.

[Detailed configuration of bead spacer]
Here, in this embodiment, the bead spacers 13A and 13B are arranged on the lower laminate 5 to produce 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 to be 11.8 or more and 35.9 or less, and the multiplication value A × B of the occupation ratio A of the bead spacers 13A and 13B and the Vickers hardness value B is set to 0.42 or more. Is done. Here, the occupation ratio A is a ratio of the area of the bead spacers 13A and 13B to the area of the lower laminate 5 in a state where the lower laminate 5 is viewed in plan (a state seen from the vertical direction). Thereby, in this embodiment, the reliability regarding a bead spacer improves further compared with the past. 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 laminated body in which the tips of the bead spacers 13A and 13B abut is less than 11.8, the tip of the bead spacers 13A and 13B is placed on the surface where the tips of the bead spacers 13A and 13B face each other. As a result, the cell gap becomes non-uniform or local alignment failure occurs. Moreover, when the Vickers hardness value B of the said part exceeds 35.9, a crack will arise when the whole is bent.

  In addition, 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, resulting in uneven cell gaps, Orientation failure occurs.

  However, the Vickers hardness value B of the portion of the upper laminate 6 in contact with the bead spacers 13A and 13B is 11.8 or more and 35.9 or less, and the multiplication value A × B of the occupation ratio A and the Vickers hardness value B is 0. If it is set to be 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 prior art.

  That is, if the Vickers hardness value B of the upper laminate 6 where the bead spacers 13A and 13B abut is 11.8 or more and 35.9 or less, the tips of the bead spacers 13A and 13B are opposed to each other by the pressing force during use. It can be prevented from penetrating the surface, and cracks can be prevented from occurring. Further, the multiplication value A × B of the occupation ratio A and the Vickers hardness value B is 0.42 or more, so that when the occupation ratio A is small, the Vickers hardness value B is set to be large. The cell gap can be maintained by the hardness B corresponding to the stress concentration on the spacer, which further ensures the non-uniformity of the cell gap, the reduction of local alignment failure, and the effective leakage of the liquid crystal material. It can be avoided. By these, the reliability regarding a bead spacer can be improved further compared with the past.

  In this way, when the bead spacers 13A and 13B having different sizes are arranged and the thickness of the liquid crystal layer is patterned, if the bead spacers 13A and 13B are greatly different in size, the above-mentioned Vickers hardness value B is multiplied. The condition of value A × B cannot be applied. However, in the case of setting the above-described difference between the repetitive 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, sufficient By applying the above-mentioned 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 conventional case.

〔Test results〕
Table 1 is a chart showing test results used for confirming the configuration of the bead spacer. The examples and comparative examples in Table 1 are configured identically except that the configurations related to 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, a bead spacer was provided only on the lower laminate 5, and the occupation ratio A was varied depending on the selection of the size of the bead spacer and the coating amount. Moreover, the Vickers hardness value B of the site | part of the 2nd laminated body which the front-end | tip of a bead spacer contact | abuts was set with the conditions at the time of manufacturing alignment layer 23A.

  In other words, the bead spacer is formed on the electrode 22B by sequentially applying a coating solution 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. Place the bead spacer randomly and difficult to move. The bead spacer adjusts the occupancy rate by adjusting the amount charged into the coating liquid and the coating film thickness of the coating liquid.

In Examples and Comparative Examples, the density of bead spacers was set to 40 / mm ² , 50 / mm ² , and 100 / mm ^2, and spherical shapes with diameters of 3 μm and 6 μm were applied to the bead spacers. . Thus, the lower laminate 5 was manufactured with the occupation ratio A of 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 provided with a hard coat layer. The electrode 22B was manufactured with a thickness of 20 nm.

  The alignment layer 23B was manufactured by coating the coating solution so as to have a dry film thickness of 100 nm and further thermosetting.

  On the other hand, the alignment layer 23A of the upper laminate 6 that is a surface with which the bead spacer abuts is the same as the alignment layer 23B. The conditions of the heat curing after applying the coating liquid and drying (heating temperature, Vickers hardness value B was set by setting such as (heating time). Thereby, in the Example and the comparative example, the upper side laminated body 6 whose Vickers hardness value B is 10.2, 11.8, 35.9, 38.5 was manufactured (Table 3). In addition, this hardness B sets the preparation conditions of the alignment layer 23A, respectively, manufactures the upper laminated body 6 from which hardness differs about the alignment layer 23A, and once manufactures the light control film 1 by this upper laminated body 6, it decomposes | disassembles. It is a measured value measured. This measurement result is a measurement result obtained by measuring 12 points and using the average value of the remaining 10 points excluding the maximum value and the minimum value.

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

  The base material 21A and electrode 22A of the upper laminate were configured the same as the base material 21B and 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 produced and tested using the upper laminate 6 and the lower laminate 5 thus produced. In the test of Table 1, after applying a weight of 1 kg / cm ² for 1 minute with a light control film placed on a smooth surface having high hardness by a surface plate, the liquid crystal cell is driven to determine the decrease in the cell gap. did. Moreover, after weighting in this way, the upper laminate and the lower laminate were peeled off and the part where the bead spacer contacted was observed with a microscope to observe penetration of the bead spacer tip.

  Here, when the part where the bead spacers 13A and 13B abut is viewed using a technique such as SEM, if a depression (recess) is confirmed, “film penetration” is determined as “x”, and the recess is not recognized. “Film penetration” was determined as “◯”.

  Further, in the state of the light control film, it was wound around a cylindrical mandrel having a diameter of 2 mm in accordance with the bending test of JIS K5600-5-1 to confirm the occurrence of cracks. In this test, when the occurrence of cracks in the substrate is confirmed in more than half of the multiple samples, “crack” is indicated by “x”, and conversely, in more than half of the multiple samples, cracks are generated in the substrate. When the occurrence is not confirmed, “crack” is indicated by “◯”.

  In the measurement results of Table 1, the Vickers hardness value B of the second laminate in contact with the bead spacers 13A and 13B is 11.8 to 35.9, and the occupation ratio A and the Vickers hardness value B are When the multiplication value A × B was 0.42 or more, it was confirmed that film penetration could be prevented and cracks were not generated, and thus it was confirmed that the reliability of the bead spacer could be sufficiently secured.

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

  FIG. 5 is a flowchart showing the upper laminate manufacturing process SP2 in detail. In the upper laminate manufacturing process SP2 (SP11), in the electrode manufacturing process SP12, the 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 alignment layer 17 is manufactured by applying and drying the coating liquid related to the alignment layer 17 and then curing it by irradiation with ultraviolet rays by linearly polarized light.

  FIG. 6 is a flowchart showing in detail the lower laminate manufacturing process SP3. In this lower laminate manufacturing process SP3 (SP21), in the electrode manufacturing process 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 alignment layer 12 is formed by applying a coating liquid related to the alignment layer 12, drying, and exposing.

  In this manufacturing process, in the subsequent small spacer arrangement step SP24, the second spacer 13B on the smaller diameter side is arranged. Here, in this embodiment, the second coating liquid in which the second spacer 13B is dispersed is sprayed on the base material 10 formed from the alignment layer 12 to dry the second coating liquid while drying the second coating liquid. The spacer 13 </ b> B is lowered to the base material 10. Here, an adhesive component is added to the coating liquid in which the second spacer 13B is dispersed. When the second spacer 13B is lowered to the base material 10 by this, the ultraviolet rays are subsequently irradiated and baked. The second spacer 13B is held at the lowered position by the added adhesive component. Accordingly, 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 obtained by manufacturing the alignment layer 12.

  In this manufacturing process, in the subsequent large spacer arrangement step SP25, the first spacer 13A on the larger diameter side is arranged. In this embodiment, a first spacer 13B is formed by arranging a mask in which an opening is manufactured at a site corresponding to the first region AR1 on a base material 10 in which second spacers 13B are randomly arranged. Mask the parts that are not placed. In this state, as in the case where the second spacer 13A is arranged, this manufacturing process sprays the coating liquid in which the first spacer 13A is dispersed on the masked base material 10, and this coating process is performed. The first spacer 13A is lowered onto the substrate 10 while the liquid is dried. Here, the adhesive component is also added to the coating liquid in which the first spacer 13A is dispersed, and when the first spacer 13A is lowered to the base material 10, it is lowered to the lowered position by subsequent curing and baking. Retained. Accordingly, in this manufacturing process, as shown in FIG. 7B, the first spacers 13A are randomly arranged in the first region AR1.

  Various methods 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 arranged using a mask. That is, for example, as shown in FIG. 8A, the first spacer 13A is applied only to the first region AR1 by spraying the coating liquid in which the first spacer 13A is dispersed in a state where the substrate 10 is masked. Deploy. Subsequently, as shown in FIG. 8B, the second spacer 13B is dispersed on the entire surface of the substrate 10 (to the first area AR1 and the second area AR2) by spraying the coating liquid in which the second spacer 13B is dispersed. The spacers 13B are dispersed and randomly arranged. In this way, the first and second spacers 13A and 13B may be arranged.

  Further, as shown in FIG. 9A, the first spacer 13A is arranged only in the first region AR1 by spraying the coating liquid in which the first spacer 13A is dispersed in a state where the substrate 10 is masked. To do. Subsequently, as shown in FIG. 9B, the second area AR2 is sprayed by spraying the coating liquid in which the second spacer 13B is dispersed in a state where the mask in which the opening is manufactured is arranged only in the second area AR2. The second spacers 13B are dispersed and randomly arranged. Thereby, the first and second spacers 13A and 13B may be arranged.

  As a result, in the first area AR1, the first and second spacers 13A and 13B may be mixed, or only the first spacer 13A having a large diameter may be disposed.

[Other Embodiments]
The specific configuration suitable for implementing the present invention has been described in detail above. However, the present invention can be combined with the above-described embodiments without departing from the gist of the present invention, and further, the above-described embodiments can be combined. Various changes can be made.

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

  In the above-described embodiment, the case where the present invention is applied to a single-domain light control film using the VA method has been described. However, the present invention is not limited thereto, and the present invention may be applied to a multi-domain light control film using the VA method. Good. In this way, when the deterioration of the color tone and the deterioration of the viewing angle characteristic in the intermediate gradation are improved by the multi domain in the first place, the deterioration of the viewing angle characteristic in the intermediate gradation can be further improved. For example, optical characteristics when the number of domains is increased by a small number of domains can be ensured.

  Further, in the above-described embodiment, the case where the light control film is attached to the part where light control is to be performed by using an adhesive layer or the like has been described, but the present invention is not limited thereto, and for example, a sheet glass such as laminated glass. The present invention can also be widely applied to the case where it is sandwiched by a transparent member such as a laminate and used integrally.

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

DESCRIPTION OF SYMBOLS 1 Light control film 2, 3 Linearly polarizing plate 3A Retardation film 4 Liquid crystal cell 5 Lower laminated body (1st laminated body)
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)

The liquid crystal layer is sandwiched between the first and second stacked bodies having at least an alignment layer, and the liquid crystal alignment of the liquid crystal layer is controlled by driving with the electrodes provided in the first and second stacked bodies. In the light control film that controls transmitted light,
By arranging 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, first and second regions having different thicknesses are provided in the liquid crystal layer. Light control film. The light control film of Claim 1. The said 1st and 2nd area | region is a strip | belt-shaped area | region. The light control film according to claim 1, wherein the spacer is a bead spacer. The light control film according to claim 1, wherein the spacer is a columnar spacer made of a photoresist. The spacer is a bead spacer provided in the first laminate;
The Vickers hardness value B of the portion of the second laminate in contact with the bead spacer is 11.8 or more and 35.9 or less,
In a state where the first laminate is viewed in plan, a multiplication value A × B of an occupation ratio A which is a ratio of an area occupied by the bead spacer on the first laminate and the Vickers hardness value B is: It is 0.42 or more. The light control film of Claim 1 or Claim 2. A first laminate production process for producing a first laminate by producing at least an orientation layer on a first substrate made of a transparent film material;
A second laminate production process for producing a second laminate by producing at least an orientation layer on a second substrate made of a transparent film material;
A lamination process for producing a liquid crystal cell in which a liquid crystal layer is sandwiched between the first and second laminates,
The first laminate manufacturing process includes:
At least a first region in which the first spacer is arranged and a second region in which only the second spacer having a thickness of 0.1 μm or more and 0.6 μm or less smaller than the first spacer is arranged in the thickness direction of the liquid crystal layer. A method for producing a light control film, comprising a spacer arrangement step of forming a region on the first base material. The first and second spacers are bead spacers;
The spacer arrangement step includes
A mask having an opening corresponding to the first region is disposed on the first base material, and the first spacer is dispersed.
The manufacturing method of the light control film of Claim 6 which forms the 1st area | region which has arrange | positioned the said 1st spacer, and the 2nd area | region which has arrange | positioned only the said 2nd spacer.

Images