JP2017021285A - Dimming material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a dimming material manufactured by employing an MVA (multi-domain vertical alignment) system, which prevents local reduction in transmittance caused by a spacer and which can be manufactured through a simple process.SOLUTION: A liquid crystal cell 4 is held between a pair of linearly polarizing plates 2, 3. The liquid crystal cell 4 includes a liquid crystal layer 8 held between first and second laminates 5D, 5U having transparent electrodes 11, 16, protruding lines 12, 17, and vertical alignment films 13, 18 successively disposed on transparent substrates 6, 15, respectively, in which alignment of a liquid crystal associated with the liquid crystal layer 8 is controlled by driving in the transparent electrodes 11, 16 disposed on the first and second laminates 5D, 5U, respectively, and thereby, transmitted light is controlled. In each of the protruding lines 12, 17 of the first and second laminates 5D, 5U, a linear portion linearly extending in the extending direction of the protruding lines 12, 17 and an oblique portion obliquely extending with respect to the extending direction are alternately disposed and the oblique portions on the first and second laminates 5D, 5U intersect each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light control material having a film shape or a plate shape that can be used for an electronic blind or the like for controlling the transmission of external light.

  Conventionally, various devices relating to a light control material by a film shape that is attached to a window to control the transmission of external light have been proposed. Regarding such a light control material, Patent Documents 1 and 2 disclose a configuration in which a liquid crystal material is sandwiched between linear polarizing plates, and the amount of transmitted light is controlled by varying an electric field applied to the liquid crystal material. .

  Patent Document 3 discloses a configuration in which a light control suspension is injected between two transparent conductive substrates. Patent Document 4 discloses a configuration using a polymer dispersed liquid crystal that changes its state between white turbidity and transparency according to an electric field. Patent Document 5 discloses a configuration in which a pair of wave plates is arranged between a pair of polarizers, and the transmittance is changed by changing the relative position of the pair of wave plates.

  In addition, a liquid crystal display panel, which is one of image display panels, includes a liquid crystal cell sandwiched between a pair of glass plates made of transparent electrodes and alignment films, and the liquid crystal cell is sandwiched between linear polarizing plates. Configured. The liquid crystal display panel displays a desired image by changing the electric field applied to the liquid crystal in units of pixels by patterning the transparent electrode.

  In such a liquid crystal display panel, columnar and spherical spacers are arranged between glass plates to maintain a constant cell gap, which is a gap between the glass plates.

  In addition, such a liquid crystal display panel has been proposed in various ways to improve the viewing angle characteristics by making it multi-domain, and Patent Document 6 provides ribs with ridges (linear protrusions), dot-like protrusions, and the like. Thus, a multi-domain vertical alignment (MVA) method in the VA (Virtical Alignment) method has been proposed.

  By the way, it is thought that various liquid crystal drive systems utilized in the liquid crystal display panel can be applied to the light control material by controlling the amount of transmitted light by controlling the polarization plane as in the liquid crystal display panel. Specifically, it is considered that when the light control material is manufactured by applying the MVA method, the light control material can be manufactured while sufficiently securing the viewing angle characteristics.

  However, when a light-modulating material is produced by the MVA method, when light is transmitted corresponding to white display, a local decrease in transmittance is observed due to the disclination of the liquid crystal derived from the spacer. There is a problem of significantly lowering. Incidentally, in the liquid crystal display device, since the spacer is covered with a black matrix which is a light-shielding portion between the pixels, there is no problem in reducing the local transmittance derived from such a spacer. . In the light control material, it is desirable to simplify the process.

JP 03-47392 A Japanese Patent Laid-Open No. 08-184273 JP 2014-146051 A JP 2013-130746 A Special table 2014-507676 gazette Japanese Patent Laid-Open No. 11-242225

  The present invention has been made in view of such a situation, and a dimming material is produced by the MVA method to prevent a decrease in local transmittance derived from the spacer, and is produced by a simpler process. The purpose is to be able to.

(1) A liquid crystal cell is sandwiched between a pair of linear polarizing plates,
The liquid crystal cell is
A liquid crystal layer is sandwiched between first and second laminates in which a transparent electrode, ridges, and a vertical alignment film are sequentially provided on a transparent substrate,
The light distribution of the liquid crystal related to the liquid crystal layer is controlled by driving the transparent electrode provided in the first and second laminates, and the transmitted light is controlled.
The ridges of the first and second laminates each have a linear portion extending linearly in the extending direction of the ridge, and an inclined portion extending obliquely with respect to the extending direction. Provided alternately,
The light control material arrange | positioned so that the said diagonal part may cross | intersect in the said 1st and 2nd laminated body.

  According to (1), the function of the spacer can be ensured by the intersection of the ridges used for the multi-domain formation, thereby eliminating the spacer and preventing the local transmittance from being lowered due to the spacer. Can do. In addition, since the process related to the spacer can be omitted, the process can be simplified.

(2) In (1),
The tip of the ridge of the first laminate and the tip of the ridge of the second laminate are in contact with each other where the oblique part intersects the first and second laminates. The light control material is such that the thickness of the liquid crystal layer is maintained at a thickness corresponding to the height of the protrusions of the first and second laminates.

  According to (2), the function of the spacer can be ensured by the intersection of the ridges used for multi-domain by a more specific configuration, whereby the spacer is omitted and the local transmittance derived from the spacer Can be prevented. In addition, since the process related to the spacer can be omitted, the process can be simplified.

(3) In (1) or (2),
The light control material whose said transparent base material is a transparent film material.

(4) In (1) or (2),
The light control material whose said transparent base material is a transparent board | plate material.

  According to (3) or (4), the dimming material can be constituted by a film shape or a plate shape to prevent a decrease in local transmittance derived from the spacer, and further simplify the process. it can.

  According to the present invention, it is possible to produce a light control material by the MVA method, prevent a decrease in local transmittance derived from the spacer, and produce it by a simple process.

It is sectional drawing which shows the light modulation material which concerns on 1st Embodiment of this invention. It is a top view with which it uses for description of the protruding item | line in the light modulation material of FIG. It is sectional drawing which shows the detailed structure of the protruding item | line in the light modulation material of FIG. It is sectional drawing of the location different from FIG. 3 with which it uses for description of a protruding item | line. It is a flowchart which shows the manufacturing process of the light modulation material of FIG.

[First Embodiment]
[Light control film]
FIG. 1 is a cross-sectional view showing a light control film which is a film-shaped light control material 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.

  This 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 by 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) The optical functional layer is sandwiched between transparent substrates such as a transparent film. The linearly polarizing plates 2 and 3 are arranged in the liquid crystal cell 4 by adhesive layers 2A and 3A made of an ultraviolet curable resin or the like in a crossed Nicol arrangement.

  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 an MVA liquid crystal cell, and is configured by sandwiching a liquid crystal layer 8 between an upper laminate 5U and a lower laminate 5D which are first and second laminates in a film shape. The lower laminate 5D is formed by laminating the transparent substrate 6, the transparent electrode 11, the rib 12, and the alignment film 13. The upper laminate 5 is formed by laminating a transparent substrate 15, a transparent electrode 16, a rib 17, and an alignment film 18.

  Various transparent films applicable to this kind of film material can be applied to the transparent substrates 6 and 15, for example, polycarbonate films, COP (cycloolefin polymer) films, TAC films, etc. with small optical anisotropy. A film material can be applied.

  Various electrode materials applied to this type of film material can be applied to the transparent electrodes 11, 16. In this embodiment, the transparent base materials 6, 15 are made of transparent electrode materials made of ITO (Indium Tin Oxide), respectively. Formed on the entire surface.

  The ribs 12 and 17 are formed by ridges extending at a certain height. In this embodiment, the light control film 1 uses the ribs 12 and 17 to locally change the alignment regulating force of the alignment films 13 and 18 to make the driving of the liquid crystal layer 8 multi-domain. Although various resin materials can be widely applied to the ribs 12 and 17, in this embodiment, the ribs 12 and 17 are made of a photoresist. On the transparent base materials 6 and 15 formed of the transparent electrodes 11 and 16, It is produced by applying a resist, exposing and developing.

  The alignment films 13 and 18 are alignment films having a function of vertically aligning the molecular axes of the liquid crystal molecules applied to the liquid crystal layer 8 by being provided as a coating film on the substrate. A liquid crystal display panel using a VA method or an MVA method. Various vertical alignment films applied to the above can be applied, for example, a polyimide alignment film can be applied. Specifically, examples of the constituent material of the alignment films 13 and 18 include silane cups such as lecithin, silane surfactants, titanate surfactants, pyridinium salt polymer surfactants, and n-octadecyltriethoxysilane. Composition for ring-type vertical alignment film, for polyimide-type vertical alignment film such as soluble polyimide having a long chain alkyl group or alicyclic structure in the side chain and polyamic acid having a long chain alkyl group or alicyclic structure in the side chain A composition. The alignment films 13 and 18 are formed by applying a coating liquid of such a vertical alignment film material, drying and heating.

  For the liquid crystal layer 8, various liquid crystal materials applied to VA mode and MVA mode liquid crystal display panels can be widely applied.

  In the liquid crystal cell 4, a sealing material 19 is arranged in a frame shape surrounding a portion where the liquid crystal layer 8 is formed. The sealing material 19 prevents leakage of the liquid crystal material, and further, the upper stacked body 5U and the lower stacked body 5D. Are bonded and integrated. Here, the sealing material 19 can be applied with various materials that can prevent the liquid crystal material from leaking and can hold the upper laminated body 5U and the lower laminated body 5D integrally. A curable resin is applied.

  Accordingly, the light control film 1 blocks the incident light by aligning the liquid crystal molecules of the liquid crystal layer 8 by the alignment regulating force of the alignment films 13 and 18 in a state where no voltage is applied to the transparent electrodes 11 and 16. Further, by applying a voltage to the transparent electrodes 11 and 16, the liquid crystal molecules are horizontally aligned to transmit incident light.

[Detailed configuration of ribs]
FIG. 2 is a plan view for explaining the detailed configuration of the ribs 12 and 17. In FIG. 2, the ribs 12 and 17 are indicated by solid lines and broken lines, respectively. The ribs 12 and 17 are formed so as to be repeated at a constant pitch P in the upper laminated body 5U and the lower laminated body 5D by means of ridges having a semicircular arc cross-sectional shape. Further, the ribs 12 and 17 have alternating linear portions 12A and 17A extending substantially linearly by a certain distance in the extending direction and oblique portions 12B and 17B extending obliquely with respect to the extending direction. Are formed so as to be repeated at a repetition pitch T. In addition, the oblique portions 12B and 17B are formed such that the direction of the extending direction is alternately switched to the left and right of the linear portions 12A and 17A in the continuous oblique portions 12B and 17B. The ribs 12 and 17 are formed to meander with an amplitude P / 2 that is ½ of the pitch P by the oblique portions 12B and 17B.

  The ribs 12 and 17 are formed in the upper laminated body 5U and the lower laminated body 5D in this way, and the upper laminated body 5U and the lower laminated body 5D are formed so that the oblique portions 12B and 17B intersect and overlap each other. Aligned and arranged. As a result, the light control film 1 has the liquid crystal molecules 8A between the ribs 12 and 17 by the ribs 12 and 17, as shown in FIG. Are tilted obliquely about the ribs 12 and 17 and vertically aligned to form a multi-domain, thereby improving viewing angle characteristics.

  Further, as shown in FIG. 4, the cross section of the intersecting portion of the ribs 12 and 17 is taken along the line BB, and the light control film 1 has the alignment films 13 and 18 at the tips of the ribs 12 and 17 at the intersecting portion. Thus, the function of the spacer is ensured, and the cell gap G of the liquid crystal cell 4 can be maintained at a constant value without providing the spacer. As a result, the ribs 12 and 17 are formed with a height of about ½ of the cell gap G of the liquid crystal cell 4, and the thickness of the liquid crystal layer 8 (cell gap G) corresponds to the height of the ribs 12 and 17. Maintained in thickness.

  Thus, in the case where the cell gap G is held by the ribs 12 and 17 by the ridges used for multi-domain formation, a local decrease in transmittance due to liquid crystal disclination as in the case of providing a spacer is prevented. can do. In addition, since the spacer can be omitted in this manner, the process for creating and arranging the spacer can be omitted, and the spacer can be easily manufactured.

  Here, when the pitch P is too short, the area of the portion where the ribs 12 and 17 are covered by the ribs 12 and 17 relatively increases, and the area of the portion where the cell gap G is correctly secured is relatively large. By reducing it to a smaller value, the effect of improving the viewing angle characteristics due to the multi-domaining is reduced. On the contrary, when the pitch P is too large, the light control film 1 perceives a difference in optical characteristics related to each domain. Thereby, the pitch P is set to 100 μm or more and 400 μm or less, preferably 100 μm or more and 250 μm or less. Similarly, the pitch T relating to the meandering in the longitudinal direction is set to 100 μm or more and 400 μm or less, preferably 100 μm or more and 250 μm or less.

  FIG. 5 is a flowchart showing the manufacturing process of the light control film. In this manufacturing process, the transparent electrodes 11 and 16 are respectively formed on the transparent substrates 6 and 15 by applying a photolithography technique in the transparent electrode manufacturing process SP2. Subsequently, in the ridge production step SP3, a photoresist film is produced on the transparent base materials 6 and 15 on which the transparent electrodes 11 and 16 are produced, and then exposed and developed, whereby the ribs 12 and 17 are produced. Subsequently, in the manufacturing process SP4 of the alignment film, the coating liquid for the alignment films 13 and 18 is applied to the surfaces of the transparent base materials 6 and 15 formed with the ribs 12 and 17, and then dried and heated. Then, the alignment films 13 and 18 are produced.

  Subsequently, in the manufacturing process, in the stacking process SP5, after applying the sealing material 19 to the lower stacked body 5D in a frame shape by a dispenser, a liquid crystal layer is formed using a dispenser at a predetermined position surrounded by the frame shape. A liquid crystal material according to No. 8 is dropped. Note that the order of the dropping of the liquid crystal material and the arrangement of the sealing material may be changed. Further, a sealing material and a liquid crystal material may be arranged in the upper laminate 5U instead of the lower laminate 5D. Thereafter, in this manufacturing process, after the upper laminated body 5U and the lower laminated body 5D are laminated, the sealing material 19 is cured by heating and pressing so that the liquid crystal layer 8 is sandwiched therebetween. And the lower laminated body 5D is bonded and integrated with a sealing material. Thereafter, in this production process, the linear polarizing plates 2 and 3 are arranged by the adhesive layers 2A and 3A such as ultraviolet curable resin in the linear polarizing plate lamination step SP6.

[Other Embodiments]
The specific configuration suitable for the implementation of the present invention has been described in detail above, but the present invention can be variously combined and modified in various ways within the scope of the present invention.

  That is, in the above-described embodiment, the case where the transparent film material is applied to the transparent base materials 6 and 15 has been described. However, the present invention is not limited thereto, and for example, a transparent plate material such as a glass plate is applied to the base material to form a plate shape. Thus, the present invention can be widely applied to the production of a light control material.

  In the above-described embodiment, the case where the ribs 12 and 17 are formed so that the direction of the extending direction is alternately switched to the left and right of the linear portions 12A and 17A in the continuous oblique portions 12B and 17B has been described. The present invention is not limited to this, and the ribs 12 and 17 may be formed so that the oblique portions 12B and 17B extend only in one direction.

DESCRIPTION OF SYMBOLS 1 Light control film 2, 3 Linearly polarizing plate 2A, 3A Adhesive layer 4 Liquid crystal cell 5D Lower laminated body 5U Upper laminated body 6,15 Base material 8 Liquid crystal layer 8A Liquid crystal component 11, 16 Transparent electrode 12, 17 Rib 12A, 17A Linear part 12B, 17B Diagonal part 13, 18 Alignment film 19 Sealing material

Claims (4)

A liquid crystal cell is sandwiched between a pair of linear polarizing plates,
The liquid crystal cell is
A liquid crystal layer is sandwiched between first and second laminates in which a transparent electrode, ridges, and a vertical alignment film are sequentially provided on a transparent substrate,
The light distribution of the liquid crystal related to the liquid crystal layer is controlled by driving the transparent electrode provided in the first and second laminates, and the transmitted light is controlled.
The ridges of the first and second laminates each have a linear portion extending linearly in the extending direction of the ridge, and an inclined portion extending obliquely with respect to the extending direction. Provided alternately,
The light control material arrange | positioned so that the said diagonal part may cross | intersect in the said 1st and 2nd laminated body. The tip of the ridge of the first laminate and the tip of the ridge of the second laminate are in contact with each other where the oblique part intersects the first and second laminates. The light control material according to claim 1, wherein the thickness of the liquid crystal layer is maintained at a thickness corresponding to the height of the protrusions of the first and second laminates. The light control material according to claim 1, wherein the transparent substrate is a transparent film material. The light control material according to claim 1, wherein the transparent base material is a transparent plate material.

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