JP2017181808A - Light control film and production method of light control film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light control film that can effectively avoid local degradation in optical characteristics due to disposition of a spacer.SOLUTION: A light control film 1 comprises a liquid crystal cell 4 held between linearly polarizing plates 2, 3, in which the liquid crystal cell 4 includes: a first laminate 5D prepared by forming a transparent electrode 11 and an alignment layer 13 on a substrate 6 made of a transparent film material; a second laminate 5U prepared by forming at least an alignment layer 17 on a substrate 15 made of a transparent film material; and a liquid crystal layer 8 held between the first and second laminates 5D, 5U. The alignment layer 13 or 17 of the first or second laminate 5D or 5U is a photo-alignment layer having a thickness of 75 nm or more and 300 nm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light control film that can be used for, for example, an electronic blind that is attached to a window 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 prepared by sandwiching a liquid crystal material with a transparent film material having a transparent electrode and an alignment layer, and a liquid crystal cell between the linear polarizing plates. 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.

  In addition, a liquid crystal display panel, which is one of the image display panels, includes a liquid crystal cell sandwiched between a pair of glass plates made of transparent electrodes and alignment layers, 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, the thickness of the liquid crystal layer is kept constant by the arrangement of the spacers in the columnar shape, and after the polyimide resin layer is produced on the glass plate material on which the spacers are arranged, the rubbing treatment is performed. An alignment layer is produced.

  It is conceivable that the light control film is produced using a method for producing a liquid crystal display panel by controlling the amount of transmitted light by controlling the polarization plane in the same manner as the liquid crystal display panel. However, simply applying a method for manufacturing a liquid crystal display panel has a problem that the transmittance when an electric field is applied, for example, is locally reduced because the alignment regulating force of the alignment layer is locally reduced.

  That is, when a spacer is provided, for example, the peripheral part of the spacer, such as the base of the spacer, becomes difficult to be sufficiently rubbed compared to other parts. The force will drop locally. Further, it is difficult to rub the peripheral part of the spacer uniformly compared to other parts, and this also causes a local decrease in the orientation regulating force as compared to other parts. As a result, when applied to a light control film, the transmittance at the time of applying an electric field locally decreases at the peripheral portion of the spacer, and as a result, the optical characteristics deteriorate locally.

  Further, when examined in detail, it was found that local deterioration of the optical characteristics caused by such a spacer also occurred in the liquid crystal display panel. However, in the liquid crystal display panel, the black matrix, which is a light-shielding portion between the pixels, is assigned to the part where the spacer is arranged, so that the part around the spacer whose optical characteristics are locally degraded is covered by this black matrix. As a result, in the liquid crystal display panel, local deterioration of the optical characteristics due to the spacer does not cause any problem. However, in the light control film, since such a light shielding portion does not exist in the first place, the user perceives local degradation of optical characteristics caused by such a spacer.

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

  The present invention has been made in view of such a situation, and makes it possible to effectively avoid local deterioration of optical characteristics due to the provision of a spacer.

  The present inventor has intensively studied in order to solve the above-mentioned problems, and has come up with the idea that a photo-alignment layer having a certain thickness is applied to the alignment layer, thereby completing the present invention.

  Specifically, the present invention provides the following.

(1) In a light control film in which a liquid crystal cell is sandwiched between linear polarizing plates,
The liquid crystal cell is
A first laminate formed by producing a transparent electrode and an alignment layer on a substrate made of a transparent film material;
A second laminate obtained by producing at least an orientation layer on a substrate made of a transparent film material;
A liquid crystal layer sandwiched between the first and second laminates,
The light control film whose alignment layer of the said 1st and 2nd laminated body is a photo-alignment layer with a thickness of 75 to 300 nm.

  According to (1), the rubbing treatment can be omitted by applying the photo-alignment layer, and the local reduction of the alignment regulating force in the vicinity of the spacer due to the application of the rubbing treatment to produce the orientation layer is effectively avoided. can do. As a result, local deterioration of optical characteristics due to the provision of the spacer can be effectively avoided. Further, by setting the thickness to 75 nm or more, the transmittance in the absence of an electric field can be sufficiently reduced and incident light can be sufficiently blocked in a wide range with respect to the viewing angle direction. Further, when the thickness is 300 nm or less, sufficient productivity can be secured.

(2) In (1),
The alignment layer of the first or second laminate is
A photo-alignment layer having an alignment regulating force to align the liquid crystal material according to the liquid crystal layer;
The alignment layer of the second or first laminate is
The light control film which is a photo-alignment layer which expresses orientation control power in the thickness direction.

  According to (2), only one of the alignment layers can be exposed to produce a light control film.

(3) In (1),
The alignment layer of the first or second laminate is
The light control film which is a photo-alignment layer which is the direction where the orientation control force which orientates the liquid-crystal material which concerns on the said liquid-crystal layer is orthogonal.

  According to (3), a light control film excellent in viewing angle characteristics can be produced with a more specific configuration.

(4) In (1),
The alignment layer of the first or second laminate is
The light control film which is a photo-alignment layer whose alignment control force which orientates the liquid crystal material which concerns on the said liquid-crystal layer is a reverse direction.

  According to (4), high transmittance can be ensured.

(5) In any one of (1), (2), (3) and (4),
A light control film in which spacers are formed in a cylindrical shape having a diameter of 9 μm or less and 25 μm or more, and are arranged with a density of 50 pieces / mm ² or more and 300 pieces / mm ² or less.

  According to (5), it is possible to effectively avoid deterioration of characteristics due to provision of the spacer with a more specific configuration.

(6) a first laminate production step of producing a first laminate by producing a transparent electrode and an alignment layer on a substrate made of a transparent film material;
A second laminate production step of producing a second laminate by producing at least an orientation layer on a substrate made of a transparent film material;
A liquid crystal cell having a liquid crystal layer sandwiched between the first and second laminates,
The first and second laminate manufacturing steps include
The manufacturing method of the light control film which coats a coating liquid to the said base material and produces the said orientation layer with the photo-alignment layer of thickness 75nm or more and 300nm or less.

  According to (6), the rubbing treatment can be omitted by applying the photo-alignment layer, and the local reduction of the alignment regulating force in the vicinity of the spacer by applying the rubbing treatment to produce the alignment layer is effectively avoided. can do. As a result, local deterioration of optical characteristics due to the provision of the spacer can be effectively avoided. Further, by setting the thickness to 75 nm or more, the transmittance in the absence of an electric field can be sufficiently reduced and incident light can be sufficiently shielded with respect to a wide viewing angle. Further, when the thickness is 300 nm or less, sufficient productivity can be secured.

  The present invention can effectively avoid local deterioration of optical characteristics due to the provision of the spacer.

It is sectional drawing 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 orientation layer in the light control film of FIG. It is a figure where it uses for description of the preparation methods of the orientation layer of FIG. It is a figure where it uses for description of the thickness of the orientation layer in the light control film of FIG. It is a figure where it uses for description of the transmittance | permeability in the light control film of FIG. It is a flowchart which shows the manufacturing process of the light control film of FIG.

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

  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 for light control film between linear 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 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 linear polarizing plates 2 and 3 are provided with retardation films 2A and 3A for optical compensation on the liquid crystal cell 4 side, respectively, but the retardation films 2A and 3A may be omitted as necessary.

  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 laminate 5D and an upper laminate 5U which are first and second laminates in the form of a film. The lower laminate 5D is formed by producing a transparent electrode 11, a spacer 12, and an alignment layer 13 on a base 6 made of a transparent film material. The upper laminate 5U is formed by laminating 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 (Virtical Alignment) method by driving the transparent electrodes 11 and 16 provided in the upper laminate 5U and the lower laminate 5D. This controls the plane of polarization of the transmitted light.

  Instead of the VA method, a driving method such as a TN (Twisted Nematic) method or an IPS (In-Place-Switching) method may be applied. When driving by the IPS method, either the transparent electrode 11 or 16 of the upper laminate 5U or the lower laminate 5D is omitted, and a driving electric field is applied to the liquid crystal material by patterning the other transparent electrode. . In addition, a driving method based on a multi-domain method may be applied.

  Although various transparent film materials applicable to this kind of film material can be applied to the base materials 6 and 15, it is desirable to apply a film material having a small optical anisotropy. In this embodiment, although a polycarbonate film is applied to the base materials 6 and 15, a COP (cycloolefin polymer) film or the like may be applied.

  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 spacer 12 is provided to define the thickness of the liquid crystal layer 8 and various resin materials can be widely applied. However, in this embodiment, the spacer 12 is made of a photoresist, and the transparent electrode 11 is made. It is produced by applying a photoresist on 6 and exposing and developing. The spacer 12 may be provided on the upper laminate 5U, or may be provided on both the upper laminate 5U and the lower laminate 5D. The spacer 12 may be provided on the alignment layer 13. Further, a so-called bead spacer may be applied as the spacer.

  The alignment layers 13 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) "and the like.

  Various liquid crystal materials applicable to this type of light control film can be widely applied to the liquid crystal layer 8. In the liquid crystal cell 4, a sealing material 19 is disposed so as to surround the liquid crystal layer 8, and the upper stacked body 5 </ b> U and the lower stacked body 5 </ b> D are integrally held by the sealing material 19, thereby preventing leakage of the liquid crystal material. .

(Orientation layer)
FIG. 2 is a diagram for explaining the alignment layers 13 and 17. In this embodiment, the alignment layers 13 and 17 of the upper stacked body 5U and the lower stacked body 5D are made of a photo-alignment layer. When the photo-alignment layer is applied to the alignment layer as described above, the rubbing treatment can be omitted, and the local alignment restriction force in the vicinity of the spacer 12 can be effectively avoided to be uniformly restricted. Can be expressed. This effectively avoids a local drop in the alignment regulating force in the vicinity of the spacer, which was a problem when an alignment layer was produced by applying a rubbing treatment, and the local optical characteristics due to the provision of the spacer. Can be effectively avoided.

  Here, the upper laminated body 5U and the lower laminated body 5D are formed in a rectangular shape in plan view. More specifically, the alignment layer 17 according to the upper stacked body 5U can set a pretilt angle in a predetermined direction over the entire surface of the upper stacked body 5U with respect to the liquid crystal material of the liquid crystal layer 8. Then, the direction of the pretilt related to the pretilt angle is set so as to be parallel to the short side direction of the upper stacked body 5U. The direction in which the liquid crystal material is tilted by the pretilt angle from the vertical direction (the direction of the alignment regulating force in the in-plane direction of the alignment layer 17) is indicated by arrows in FIG.

  On the other hand, the orientation layer 13 of the lower stacked body 5D is set so that the direction orthogonal to the direction of the orientation regulating force of the orientation layer 17 becomes the direction of the orientation regulating force. Thereby, in this embodiment, the direction of the alignment regulating force in the alignment layers 13 and 17 facing each other can be set to the direction of the twist relationship, thereby reducing the disclination by the spacer 12 and improving the transmittance. Can do.

  Instead of the configuration shown in FIG. 2A, the orientation regulating force direction of the alignment layers 13 and 17 may be set in the opposite direction as shown in FIG. Parallel setting). With this setting, it is possible to improve the transmittance when an electric field is applied.

  The alignment layers 13 and 17 are coated with a coating liquid related to the photo-alignment layer, and then dried to form a material layer related to the alignment layers 13 and 17. Thereafter, as shown in FIG. 3, a light source is disposed at a position displaced from the vertical direction in the direction opposite to the pretilt direction in the alignment layers 13 and 17, and linearly polarized ultraviolet light L is applied to the base materials 6 and 15 from the light source. Is incident obliquely at an incident angle θ, and the exposure process is executed, whereby the orientation regulating force is expressed on the entire surface of the substrate 15.

  In addition, you may make it utilize efficiently the ultraviolet-ray L which is used for this exposure process and the ultraviolet-ray generated with the light source by irradiating a non-polarized ultraviolet-ray. In addition, from the viewpoint of efficiently producing the photo-alignment layer with a small amount of light, the incident angle θ is preferably 45 degrees, but may be 40 degrees or more and 50 degrees or less.

  As shown in FIG. 2C, one of the alignment layers 13 and 17 may be produced without applying an exposure treatment by applying a coating liquid relating to the photo-alignment layer and then drying it. Further, after drying in this manner, it may be produced by irradiating non-polarized ultraviolet rays from the front.

  Here, the alignment layer prepared without being exposed to light or the alignment layer prepared by irradiating unpolarized ultraviolet light from the front has a thickness without expressing the alignment regulating force in the horizontal direction. It exerts orientation regulating force in the direction and functions as a vertical alignment layer. Specifically, in this case, the alignment layer aligns adjacent liquid crystal molecules in the vertical direction with a pretilt angle of 89.9 degrees or more and 90.0 degrees or less. Here, when the pretilt angle is 85 degrees or more and 89.9 degrees or less, preferably when the pretilt angle is 85 degrees or more and 89.5 degrees or less, the liquid crystal molecules are tilted in the direction of the pretilt angle by changing the electric field. However, due to the inclination by the pretilt angle, light leakage occurs when light is blocked, and the light cannot be sufficiently blocked. However, as in this embodiment, in the case of aligning in the vertical direction with a pretilt angle of 89.9 degrees or more and 90.0 degrees or less, such light leakage can be prevented and light can be sufficiently shielded. In this case, the liquid crystal molecules are collapsed by the application of an electric field and the amount of transmitted light is controlled by the facing alignment layers. The pretilt angle is measured by measuring the in-plane phase value Re using an optical measuring device such as Rets (manufactured by Otsuka Electronics) or Axostep (manufactured by Axometrics) while varying the tilt of the measuring object or light source. Can do.

  If one of the alignment layers is made of a vertical alignment layer in this way, the manufacturing process can be simplified.

  Here, the alignment layers 13 and 17 are formed with a thickness of 75 nm to 300 nm. FIG. 4 is a diagram showing the transmittance when no electric field is applied when a light control film is produced by setting the thickness of the photo-alignment layers 13 and 17. If the thickness of the alignment layers 13 and 17 is less than 75 nm, the transmittance in the absence of an electric field increases, and as a result, sufficient light shielding cannot be achieved. On the other hand, if the thickness is too large, the productivity will deteriorate. As a result, it can be produced with a thickness of 75 nm or more and 300 nm or less, and incident light can be sufficiently shielded while ensuring sufficient productivity. FIG. 4 shows the measurement results when the liquid crystal layer is configured with the settings shown in FIG.

  By the way, even when the local alignment degradation is prevented by the spacer 12 by applying the photo-alignment layer as described above, the spacer 12 itself has different optical characteristics from the surrounding liquid crystal layer 8, and thus the liquid crystal layer 8. This will affect the control of the transmitted light. Accordingly, in this embodiment, the spacer 12 is formed by a cylindrical shape having a circular cross section having a diameter of 25 μm or less and 9 μm or more, more preferably a circular cylinder having a circular shape having a diameter of 12 μm or less and 9 μm or more. Although it arrange | positions with the density of piece / mm <2> or less, it arrange | positions with the density of 50 piece / mm <2> -100 piece / mm <2> or less preferably.

  The spacer 12 is made of black using a material that absorbs transmitted light, and is set so that the spacer 12 does not stand out at the time of light shielding and the light shielding property is not impaired by the spacer 12. More specifically, the spacer 12 is made of black by coloring using a dye or pigment of a photoresist used for the production. The spacer 12 may be manufactured so as to absorb transmitted light, and may be manufactured using white black (gray) instead of black or may be manufactured using purple black. Good. In addition, the spacers 12 are irregularly arranged, thereby preventing the moire from being generated by the spacers 12 in the light control film 1.

  FIG. 5 is a characteristic curve diagram showing the transmittance of the light control film thus produced. Reference numerals LA, LB, and LC are measurement results of the light control film having the alignment layers shown in FIGS. 2A, 2B, and 2C, respectively. From the measurement result of FIG. 5, it can be seen that the transmittance can be improved by setting the so-called anti-parallel orientation regulating force. Reference symbol LX is a measurement result when the alignment layers 13 and 17 are produced by rubbing treatment.

〔Manufacturing process〕
FIG. 6 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 spacer preparation step SP3, a photoresist film is prepared on the transparent substrate 6 on which the transparent electrode 11 is prepared, and then exposed and developed, whereby the spacer 12 is prepared. Subsequently, in the manufacturing process, the alignment layers 13 and 17 are formed on the base materials 6 and 15 in the alignment layer manufacturing process SP4.

  Here, in this alignment layer preparation step SP4, in the coating step SP4-1, after coating the coating liquid related to the photo-alignment layer on the substrates 6 and 15, respectively, in the subsequent drying step SP4-2. Then, the solvent of this coating solution is scattered to dry the coating layer. In the manufacturing process, the coating liquid related to the photo-alignment layer is applied so that the dry film thickness is 75 nm or more and 300 nm or less at this time, and thereby the photo-alignment layer is held at the above-described thickness.

  Moreover, this manufacturing process irradiates the material layer of the alignment layer formed on the base materials 6 and 15 with ultraviolet rays in the subsequent exposure process SP4-3 to set the alignment regulating force on the entire surface. In the case of the configuration shown in FIG. 2C, the alignment layer 13 is formed from the dried material layer of the photo-alignment layer on the base 6 side without performing an exposure process.

  Thus, when the orientation layers 13 and 17 are produced on the substrates 6 and 15, respectively, and the lower laminate 5D and the upper laminate 5U are produced, this manufacturing process is performed by using a dispenser with a dispenser in the sealing process SP5. After 19 is applied to the lower laminate 5D in a frame shape, the liquid crystal material related to the liquid crystal layer 8 is dropped into a predetermined position surrounded by the frame shape using a dispenser. 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. Then, this manufacturing process arrange | positions the linearly-polarizing plates 2 and 3 by adhesive layers, such as an ultraviolet curable resin.

[Detailed configuration of spacer]
Here, in this embodiment, the spacer 12 is formed by a columnar shape or a truncated cone shape. Further, in this embodiment, the Vickers hardness value Xs of the spacer 12 and the Vickers hardness value Xf of the portion where the tip of the spacer 12 abuts are Vickers hardness value 2 or more and Vickers hardness value 6 or less, and Xs <Xf. Thus, the reliability related to the spacer is further improved as compared with the related art.

  That is, in the case of Xf <Xs, the tip of the spacer 12 penetrates into the opposite surface due to the pressing force during use, and as a result, the cell gap becomes non-uniform or local alignment failure occurs. Further, in a severe case, the liquid crystal material leaks by breaking through the laminated body where the tip of the spacer 12 is opposed. However, by satisfying Xs <Xf, it is possible to reduce the situation where the tip of the spacer penetrates into the opposite surface due to the pressing force during use, etc., thereby making the cell gap non-uniform and local orientation. Generation | occurrence | production of a defect can be reduced and also the leakage of liquid crystal material can be avoided effectively.

  If the Vickers hardness value is less than 2, the spacer is crushed by the external pressure and the cell gap is reduced, and the desired cell gap cannot be obtained. In this embodiment, the Vickers hardness value is 2 or more. Such a situation can be reduced. Further, when the Vickers hardness value is more than 6, the substrate is easily damaged, and cracks are generated when the whole is bent. In this embodiment, the Vickers hardness value is 6 or less, so that the substrate is damaged. And the occurrence of cracks when the whole is bent can be reduced. By these, the reliability regarding a spacer can be improved further compared with the past.

  Table 1 is a chart showing test results used for confirmation of the configuration related to the spacer. The light control films of Test Examples 1 to 6 in Table 1 are configured identically except that the configurations regarding the spacer and the alignment layer with which the spacer contacts are different. More specifically, in the light control films of Test Examples 1 to 6, the spacer 12 is provided only on the lower laminate 5D, and the Vickers hardness value Xs of the spacer 12 is set according to the heat treatment conditions related to the spacer 12. did.

  In other words, the spacer 12 is coated with the coating liquid related to the spacer 12 and then dried, and then a portion where the spacer 12 is produced is selectively exposed by mask exposure using an exposure apparatus. Note that this is a case of a positive type photoresist. On the contrary, in the case of a negative type photoresist, a part other than the part for producing the spacer 12 is selectively exposed. Thereafter, the spacer 12 is selectively removed at the unexposed portion or the exposed portion by development processing, and processing such as rinsing is performed, and processing such as drying is performed as necessary.

  In this exposure process, exposure may be performed in a so-called half-cure state by heating in advance or in a heated environment. In the development process, after rinsing or the like is performed, the heat treatment is performed. May accelerate the reaction. The hardness Xs of the spacer 12 can be set by selecting a photoresist material related to the spacer 12, setting the heating temperature and time in the exposure process and the development process, and setting the exposure light amount and the exposure time.

  In this embodiment, the Vickers hardness value Xs of the spacer 12 in Test Examples 1, 5, and 6 is set to 1.8, 4.2, and 4.2, respectively, by setting the heating temperature and time in the exposure process and the development process. The Vickers hardness value Xs of the spacer 12 in Test Examples 2, 3, and 4 was set to 2.2, 3.7, and 4.2, respectively. The spacer 12 was produced in a cylindrical shape having a diameter of 15 μm and a height of 5 μm.

  On the other hand, the alignment layer 17 of the upper laminate 5U, which is the surface with which this spacer abuts, was prepared by rubbing treatment instead of the photo-alignment layer. That is, a polyimide film was prepared by applying a coating liquid, drying and curing, and this polyimide film was prepared by rubbing. Moreover, the Vickers hardness value Xf was set by the setting of the heating temperature at the time of hardening at the time of producing this polyimide film and the heating time. Note that the Vickers hardness value Xf may be adjusted by performing another heat treatment after the rubbing treatment. Thus, in Test Examples 1, 5, and 6, the Vickers hardness value Xf was set to 4.9, 6.7, and 3.6, and in Test Examples 2, 3, and 4, the Vickers hardness value Xf was set to 4.9. .

  In this experiment, a load corresponding to 0.8 MPa was applied in a state where the light control film was placed on a smooth surface having high hardness by a surface plate, and then the cell gap was measured to determine the decrease in the cell gap. The weighting time is 24 hours. After weighting in this way, the upper laminate and the lower laminate are peeled off and the spacer is observed with a microscope to check for collapse of the spacer (spacer collapse), and the part where the spacer contacts is observed with a microscope. The penetration of the spacer tip (film penetration) was observed.

  Here, for observation with this microscope, a front view, a perspective view, and a cross-section are observed using a method such as SEM, and the deformation of the spacer is visually confirmed. When the deformation of the spacer is confirmed, according to the situation, “ The presence or absence of “cell gap reduction, spacer crushing” was judged as “Good”. Therefore, in Table 1, “◯” indicates a case where no abnormality related to the corresponding item is observed, and “X” indicates a case where abnormality regarding the corresponding item is observed.

  Similarly, if the part where the spacer abuts is perspective using a technique such as SEM, if a dent (recess) is confirmed, “film penetration” is determined as x, and if no recess is observed, “film penetration” Was rated as ○.

  Further, in a state where the laminates 5U and 5D were laminated and a load corresponding to 0.1 MPa was applied, the relative positions of the laminates 5U and 5D were displaced by 0.1 cm / sec, and the occurrence of scratches was confirmed visually. Here, when scratches are confirmed in more than half of the multiple samples, “scratch (film)” is indicated by “x”, and conversely, scratches are not confirmed in more than half of the multiple samples. In this case, “scratch (film)” is indicated by “◯”.

  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 cracks are confirmed in the substrate in more than half of the multiple samples, “crack (film)” is indicated by “x”, and conversely, in more than half of the multiple samples, the substrate In the case where the occurrence of cracks is not confirmed, “crack (film)” is indicated by “◯”.

  In the measurement results of Table 1, in Test Example 1, due to insufficient spacer hardness, cell gap reduction and spacer crushing are observed, and in Test Example 5, the Vickers hardness value Xf of the spacer facing surface exceeds 6. Thus, generation of cracks was observed, and further, cell gap reduction and spacer collapse were observed. In Test Example 6, since the Vickers hardness value Xs of the spacer was larger than the Vickers hardness value Xf of the opposing surface, the substrate was observed to be damaged, and the penetration of the spacer tip was also confirmed. However, in Test Examples 2, 3, and 4, these phenomena are not observed, and the reliability related to the spacer can be further improved as compared with the related art.

  The adjustment of the Vickers hardness value Xf of the alignment layer 17 of the upper laminate 5U is not limited to the rubbing process, but can also be adjusted in the case of the photo-alignment layer.

[Example 1]
A polycarbonate film material having a thickness of 100 μm formed by forming hard coat layers on both sides was applied to the base materials 6 and 15, and a light control film was produced according to the configuration of the above-described embodiment. The alignment layers 13 and 17 were produced by the anti-parallel setting described above with reference to FIG. 2B by oblique exposure of non-polarized ultraviolet rays with a thickness of 75 nm and an exposure amount during exposure treatment of 20 mJ / cm ² . In Example 1, the transmittance when no electric field is applied and when the electric field is applied is 0.0% and 35.5%, respectively, so that the incident light is sufficiently shielded when the light is blocked, and the transmittance is sufficiently transmitted when the light is transmitted. It was confirmed that it can be secured. Further, it was not possible to visually confirm the decrease in local transmittance due to the spacer.

[Example 2]
In this embodiment, a light control film was produced in the same manner as in Example 1 except that the alignment layers 13 and 17 were produced with a thickness of 100 nm. This light control film has a transmittance of 0.0% and 35.6% when no electric field is applied and when an electric field is applied, respectively, and sufficiently blocks incident light when shielded from light. It was confirmed that it can be secured. Further, it was not possible to visually confirm the decrease in local transmittance due to the spacer.

Example 3
In this embodiment, the light control film was comprised similarly to the above-mentioned Example 2 except the point which made the exposure amount at the time of an exposure process 40 mJ / cm < ² >. This light control film has transmittances of 0.0% and 35.4% when no electric field is applied and when an electric field is applied, respectively, and sufficiently blocks incident light when blocked and further transmits sufficiently when transmitted. It was confirmed that it can be secured. Further, it was not possible to visually confirm the decrease in local transmittance due to the spacer.

Example 4
In this embodiment, the light control film was comprised similarly to the above-mentioned Example 3 except the point which made the exposure amount at the time of an exposure process 5 mJ / cm < ² >. This light control film has transmittances of 0.0% and 35.4% when no electric field is applied and when an electric field is applied, respectively, and sufficiently blocks incident light when blocked and further transmits sufficiently when transmitted. It was confirmed that it can be secured. Further, it was not possible to visually confirm the decrease in local transmittance due to the spacer.

[Comparative Examples 1 and 2]
In Comparative Example 1, the alignment layers 13 and 17 were produced by oblique irradiation with non-polarized ultraviolet rays having a thickness of 55 nm and an exposure amount of 20 mJ / cm ² . In Comparative Example 2, alignment layers 13 and 17 were produced by oblique irradiation with non-polarized ultraviolet rays having a thickness of 25 nm and an exposure amount of 20 mJ / cm ² . Comparative Examples 1 and 2 were produced in the same manner as Example 1 except for the configuration related to the alignment layers 13 and 17. Comparative Example 1 has a transmittance of 0.3% and 35.0% when no electric field and an electric field are applied, respectively, and Comparative Example 2 has a transmittance of 0.5% when no electric field and an electric field are applied, respectively. It was 35.0%, and it was confirmed that the light could not be sufficiently shielded when the light was shielded by no electric field. In addition, in the fall of the local transmittance | permeability by a spacer, it was not able to confirm by visual observation.

[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 liquid crystal layer is driven by a so-called monodomain in which a uniform alignment regulating force is expressed on the entire surface of the alignment layer has been described. The present invention can be widely applied to the case of multi-domain such as. Incidentally, in a multi-domain of two domains, one of the alignment layers 13 and 17 is formed by patterning the first and second regions having different alignment regulating force directions by repeated exposure processing, and the other alignment layer is formed. By applying the above-described configuration, it is possible to make a multi-domain. Similarly, in the case of a four-domain multi-domain, one of the alignment layers 13 and 17 is formed by patterning in the first to fourth regions having different orientation regulating force directions, and the above-described alignment layer is formed on the other alignment layer. By applying the configuration, a multi-domain can be realized. Further, the alignment layers 13 and 17 are formed by patterning with the first and second belt-like regions having different orientation regulating force directions, and the first and second belt-like regions are arranged so as to cross each other. Can be domainized.

  Thus, even when producing by multi-domain, the same effect as the above-mentioned embodiment can be acquired.

  In the above-described embodiment, the case where a liquid crystal cell is manufactured by stacking and integrating two stacked bodies 5D and 5U with a liquid crystal material interposed therebetween is not limited to this, and the present invention is not limited to this. After stacking and integrating, the present invention can also be widely applied to a case where a liquid crystal cell is manufactured by disposing a liquid crystal material between the two stacked bodies 5D and 5U.

DESCRIPTION OF SYMBOLS 1 Light control film 2, 3 Linearly polarizing plate 2A, 3A Phase difference film 4 Liquid crystal cell 5D Lower laminated body 5U Upper laminated body 6, 15 Base material 8 Liquid crystal layer 11, 16 Transparent electrode 12 Spacer 13, 17 Orientation layer 19 Seal Material

Claims (6)

In the light control film formed by sandwiching the liquid crystal cell with a linear polarizing plate,
The liquid crystal cell is
A first laminate formed by producing a transparent electrode and an alignment layer on a substrate made of a transparent film material;
A second laminate obtained by producing at least an orientation layer on a substrate made of a transparent film material;
A liquid crystal layer sandwiched between the first and second laminates,
The light control film whose alignment layer of the said 1st and 2nd laminated body is a photo-alignment layer with a thickness of 75 to 300 nm. The alignment layer of the first or second laminate is
A photo-alignment layer having an alignment regulating force for aligning a liquid crystal material according to the liquid crystal layer;
The alignment layer of the second or first laminate is
The light control film according to claim 1, which is a photo-alignment layer that exhibits an alignment regulating force in a thickness direction. The alignment layer of the first or second laminate is
The light control film of Claim 1. It is a photo-alignment layer which is the direction where the orientation control force which orientates the liquid-crystal material which concerns on the said liquid-crystal layer is orthogonal. The alignment layer of the first or second laminate is
The light control film of Claim 1. It is a photo-alignment layer whose alignment control force which orientates the liquid-crystal material which concerns on the said liquid-crystal layer is a reverse direction. The spacer is formed in a cylindrical shape having a diameter of 9 μm or less and 25 μm or more, and is arranged with a density of 50 pieces / mm ² or more and 300 pieces / mm ² or less. Any one of claims 1, 2, 3, and 4 The light control film of crab. A first laminate production step of producing a first laminate by producing a transparent electrode and an orientation layer on a substrate made of a transparent film material;
A second laminate production step of producing a second laminate by producing at least an orientation layer on a substrate made of a transparent film material;
A liquid crystal cell having a liquid crystal layer sandwiched between the first and second laminates,
The first and second laminate manufacturing steps include
The manufacturing method of the light control film which coats a coating liquid to the said base material and produces the said orientation layer with the photo-alignment layer of thickness 75nm or more and 300nm or less.

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