JP2009008899A - Method for manufacturing laminated layer-type optically functional layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a laminated layer-type optically functional layer, wherein the method can prevent the occurrence of an exfoliation and residual film of an optically functional layer formed on a polymer-type liquid crystal layer. <P>SOLUTION: The method for manufacturing a laminated layer-type optically functional layer 10 includes a process in which a polymer-type liquid crystal layer 10A (a first optically functional layer) is formed on one side of a glass substrate 11; a process in which the polymer-type liquid crystal layer 10A thus formed is subjected to plasma processing; and a process in which a color filter layer 10B (a second optically functional layer) is formed on the surface of the polymer-type liquid crystal layer 10A which is subjected to the plasma processing. The plasma processing is made to the surface of the polymer-type liquid crystal layer 10A to reform its surface, and the close contactability of the color filter layer 10B to the polymer-type liquid crystal layer 10A is controlled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a laminated optical functional layer formed by laminating a polymerizable liquid crystal layer and an optical functional layer.

  Conventionally, in a liquid crystal display device, a retardation film (retarding element) is used as a viewing angle compensation film, a linear polarizing plate, or an absorption circular polarizing plate (λ / 4 plate, λ / 2 plate) in various liquid crystal modes. is set up. In recent years, there has been proposed a film in which this retardation film is formed by using a liquid crystal layer made of a polymerization type polymer liquid crystal material (for example, Patent Documents 1 to 6).

In particular, Patent Document 1 proposes a technique (in-cell) in which a retardation film made of a polymerization type liquid crystal as described above is provided inside a liquid crystal display device in order to improve reliability such as heat resistance and chemical resistance. Yes. Patent Document 6 proposes a configuration in which a color filter is laminated on a retardation film. Thus, when the retardation film is in-cell, the other optical functional layer such as a color filter is formed in close contact with one surface of the retardation film.
JP 7-199173 A JP 2001-500904 A JP 2001-56484 A JP 2005-272560 A USP 5,612,801 JP-A-4-12324

  However, as described above, in the case where a retardation film composed of a polymerization type liquid crystal layer is used as an in-cell and another optical functional layer such as a color filter is formed thereon, the polymerization is performed depending on the material constituting the optical functional layer. Adhesiveness to the liquid crystal layer became too high (or too low), and appropriate adhesiveness could not be secured. For this reason, there has been a problem that film peeling or film residue occurs when the optical functional layer is formed.

  The present invention has been made in view of such problems, and its object is to provide a method for producing a laminated optical functional layer capable of preventing film peeling and film residue of an optical functional layer formed on a polymerization type liquid crystal layer. It is to provide.

  The method for producing a laminated optical functional layer according to the present invention includes a step of forming a first optical functional layer made of an alignment-regulated polymerization type liquid crystal on a transparent substrate, and a plasma treatment on the surface of the first optical functional layer. And a step of forming the second optical functional layer on the surface of the first optical functional layer that has been subjected to the plasma treatment.

  In the method for producing a laminated optical functional layer according to the present invention, the surface of the first optical functional layer is modified by performing plasma treatment on the surface of the first optical functional layer composed of the alignment-controlled polymerization type liquid crystal. The By forming the second optical functional layer on this surface, the adhesion of the second optical functional layer to the first optical functional layer is adjusted to an appropriate size.

  According to the method for producing a laminated optical functional layer of the present invention, the second optical functional layer is formed after the plasma treatment is performed on the surface of the first optical functional layer made of the alignment-controlled polymerization type liquid crystal. Therefore, the adhesion of the second optical functional layer to the first optical functional layer is adjusted, and it becomes possible to prevent film residue and film peeling of the second optical functional layer.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a liquid crystal display device 1 including a laminated optical functional layer 10 according to an embodiment of the present invention. The liquid crystal display device 1 includes a laminated optical functional layer 10 in which a color filter layer (second optical functional layer) 10B is formed on one surface of a polymerization liquid crystal layer 10A (first optical functional layer). It has become. The liquid crystal display device 1 includes an alignment film 12, a laminated optical functional layer 10, a first electrode 13, an alignment film 14, a liquid crystal layer 15, an alignment film 16, and a second electrode 17 between a pair of glass substrates 11 and 18. Are laminated in this order, and a polarizing plate 20 is attached to the upper surface of the glass substrate 11, and a retardation plate 19 and a polarizing plate 21 are attached to the lower surface of the glass substrate 18. Further, a light source 22 and a reflection plate 23 are provided below the polarizing plate 21. Such a liquid crystal display device 1 is used as a display monitor for electronic devices such as a liquid crystal television and a notebook computer.

  On one surface of the glass substrate 11, a polymerized liquid crystal layer 10 </ b> A of the laminated optical functional layer 10 is formed via an alignment film 12. In the liquid crystal display device 1, the polymerization type liquid crystal layer 10 </ b> A functions as, for example, a retardation film for viewing angle compensation.

  The polymerization type liquid crystal layer 10A is made of, for example, a material having alignment regularity of liquid crystal molecules as shown in FIGS. FIG. 2A shows a horizontally aligned nematic liquid crystal 10A-1, in which rod-shaped liquid crystal molecules are aligned in the horizontal direction with respect to the substrate surface. FIG. 2B shows a vertically aligned nematic liquid crystal 10A-2 in which rod-like liquid crystal molecules are aligned in a direction perpendicular to the substrate surface. FIG. 2C shows a cholesteric liquid crystal 10A-3 in which rod-like liquid crystal molecules are arranged in a spiral while rotating in a plane horizontal to the substrate surface. FIG. 2D shows a hybrid orientation in which the tilt angle gradually changes as the disc-like or rod-like liquid crystal molecules move away from the substrate surface.

  The polymerization type liquid crystal layer 10A can obtain a predetermined retardation depending on the alignment (alignment state) of the liquid crystal molecules. The alignment film 12 is for controlling the alignment of the polymerization type liquid crystal layer 10A, and is composed of, for example, a resin material such as polyimide (PI), polyamide, polyvinyl alcohol or the like subjected to an alignment treatment such as rubbing. Has been. Alternatively, the glass substrate 11 and the alignment film 12 may be integrated by using an orientation supporting substrate such as a stretched film.

  The color filter layer 10B is provided adjacent to the polymerization type liquid crystal layer 10A. For example, as shown in FIG. 3, R (red), G (green), B (blue) are formed in the opening region of the black matrix BM. These three color filters are regularly arranged. The color filters R, G, and B are, for example, pigment dispersion type color filters, which effectively transmit any one color of red, green, and blue components, and transmit light of the other two colors. If it absorbs effectively, it will not be specifically limited. Further, it may be a transmission type or a reflection type. The thicknesses of the color filters R, G, and B are each about 1 μm to 2 μm, for example.

The black matrix BM is for dividing the light-emitting area for each pixel, preventing reflection of external light at the boundary between the areas of the respective colors, preventing light leakage between the pixels, and increasing the contrast. This black matrix BM is formed by laminating thin layers of metal, metal oxide and metal nitride, for example, a two-layer chrome black matrix composed of a laminate of CrO _x (x is an arbitrary number) and Cr, or reflectivity. It is composed of a three-layer chrome black matrix or the like composed of laminated layers of reduced CrO _x , CrN _y and Cr (x and y are arbitrary numbers), and has a thickness of 0.2 μm to 2.0 μm, for example.

  The liquid crystal layer 15 is made of a liquid crystal material such as a nematic liquid crystal, a smectic liquid crystal, or a cholesteric liquid crystal, and has a cell structure such as a VA (Vertical Alignment) mode, an IPS (In Plane Switching) mode, or a TN (Twisted Nematic) mode. is doing. The first electrode 13 and the second electrode 17 are made of a transparent electrode such as ITO (indium tin oxide), and the alignment films 14 and 16 are made of a resin material such as polyimide.

  The polarizing plates 20 and 21 transmit polarized light that vibrates in a specific direction, and are arranged so that their transmission axes are orthogonal to each other. As the light source 22, for example, an edge light type backlight using a light guide plate or the like is used, and light is irradiated to the polarizing plate 21 side. However, the present invention is not limited to this, and a direct type backlight may be used. The reflection plate 23 is provided for diffusing the light returned from the light source 22 or the polarizing plate 21 side and using it again as display light (recycling).

  Next, a method for forming the multilayer optical functional layer 10 of the liquid crystal display device 1 as described above will be described with reference to FIGS. The method of forming the laminated optical functional layer 10 includes a step of forming a polymerization liquid crystal layer 10A (first optical functional layer) on one surface side of the glass substrate 11, and a plasma treatment on the surface of the formed polymerization liquid crystal layer 10A. And a step of forming a color filter layer 10B (second optical functional layer) on the surface of the polymerization-type liquid crystal layer 10A subjected to the plasma treatment. FIG. 4 schematically shows an example of liquid crystal molecules aligned in a predetermined direction in the liquid crystal layer 10A-1 and the polymerization type liquid crystal layer 10A.

(Formation of polymerization type liquid crystal layer 10A)
First, as shown in FIG. 4A, an alignment film 12 made of the above-described material or the like is formed on one surface of a glass substrate 11, and the alignment film 12 is subjected to an alignment regulation process such as a rubbing process. . The rubbing treatment can be performed, for example, by rubbing a rubbing cloth made of a material such as rayon, cotton, polyamide, polymethyl methacrylate, etc. on a metal roll and rotating the roll in a state of being in contact with the alignment film 12.

  Next, as illustrated in FIG. 4B, the liquid crystal layer 10 </ b> A- 1 is formed over the alignment film 12 that has been subjected to the alignment regulation process. At this time, for example, when a liquid crystal material that does not exhibit a liquid crystal phase at room temperature is used, alignment treatment is performed by heat treatment. Thus, the liquid crystal molecules in the liquid crystal layer 10 </ b> A- 1 are aligned in a desired direction by performing alignment regulating force or heat treatment of the alignment film 12. As the liquid crystal material, a polymer liquid crystal material having polymerizability, for example, nematic liquid crystal shown in Chemical Formulas 1 to 5 or cholesteric liquid crystal is used, and two or more kinds may be mixed as necessary. At this time, the liquid crystal material is, for example, various solvents in which the liquid crystal material is soluble (toluene, xylene, acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, PGME (propylene glycol monomethyl ether), diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, PGMEA (propylene The liquid crystal layer 10A-1 can be easily formed on the alignment film 12 by various coating methods such as spin coating, for example, by dissolving in a single or mixed solvent such as glycol monomethyl ether acetate or ethyl acetate). In this case, the solvent used is removed by performing, for example, heat treatment or reduced-pressure drying treatment after the liquid crystal layer 10A-1 is formed.

  Further, as additives to the liquid crystal layer 10A-1, for example, MegaFac R-08, R-90, F-483 (trade name; manufactured by Dainippon Ink Co., Ltd.), BYK361 (trade name; manufactured by Big Chemie), Polyflow 461 A surfactant such as (trade name; manufactured by Kyoeisha Chemical Co., Ltd.) can be used. The addition amount of the surfactant is preferably about 0.01% by weight to 10% by weight with respect to the liquid crystal material as long as the alignment of the liquid crystal is not inhibited. Furthermore, IRGACUR907, 369, 184, 819, OXE01, OXE02 (trade name; manufactured by Ciba Specialty Chemicals), Lucillin TPO (trade name; manufactured by BASF), and the like can be used as a photoinitiator. Depending on the case, two or more kinds may be used, or other photoinitiators may be mixed. The amount of photoinitiator added is in the range of 0.01 wt% to 15 wt%, preferably 0.1 wt% to 12 wt%, more preferably 0.5 wt% to 10 wt%.

  Next, as shown in FIG. 4C, the formed liquid crystal layer 10A-1 is subjected to a three-dimensional crosslinking process by, for example, irradiating with ultraviolet rays (UV). At this time, as a light source for irradiating ultraviolet rays UV, for example, a mercury excitation light source such as a low-pressure mercury lamp, a high-pressure mercury lamp, or an ultra-high pressure mercury lamp, or a xenon light source can be used. However, it is preferable to select a light source having an intensity peak in a wavelength region where the photoinitiator has high sensitivity. Thereby, the molecules in the liquid crystal layer 10A-1 can be combined in a three-dimensional chain shape or network shape, and the liquid crystal layer 10A-1 can be cured. This three-dimensional crosslinking treatment can be performed by irradiating radiation such as particle beams or electromagnetic rays in addition to ultraviolet rays.

  Subsequently, a polymerization treatment is performed on the liquid crystal layer 10A-1 subjected to the three-dimensional crosslinking treatment in order to further promote the crosslinking. The polymerization treatment is performed, for example, by performing a heat treatment at 150 ° C. to 250 ° C. (thermal polymerization) in an air or nitrogen atmosphere. Thereby, the molecules in the liquid crystal layer 10A-1 are polymerized, and the polymerization type liquid crystal layer 10A as a retardation film can be formed.

(Plasma treatment)
Next, as shown in FIG. 4D, plasma treatment is performed on the surface of the formed polymerization type liquid crystal layer 10A. The plasma treatment is not particularly limited as long as it does not break the three-dimensional cross-linking structure inside the polymerization type liquid crystal layer 10A, but is preferably an atmospheric pressure (AP) plasma treatment. At this time, depending on the constituent materials of the polymerization type liquid crystal layer 10A and the optical functional layer 10B and the degree of adhesion required between them, processing conditions such as gas flow rate, power, and gap with the substrate (film surface) The distance from the electrode to the electrode), the transport speed, etc. are set as appropriate.

(Formation of color filter layer 10B)
Next, the color filter layer 10B is directly formed on the surface of the polymerization type liquid crystal layer 10A subjected to the plasma treatment. First, a thin film laminate containing the above-mentioned metal chromium is formed on the surface of the polymerizable liquid crystal layer 10A by, for example, vapor deposition, ion plating, sputtering, or the like. At this time, the use of the above-mentioned material containing metallic chromium is advantageous in terms of optical density, cleaning resistance, processing characteristics, and the like. Subsequently, the black matrix BM is formed on the formed thin film stack through processes such as application of a photoresist, exposure using a pattern mask, development, etching, and washing by, for example, photolithography. . The black matrix BM can also be formed by an electroless plating method or a printing method using a black ink composition.

  After that, the color filters R, G, B are formed by patterning in the opening area of the black matrix BM using, for example, a photolithography method, or an ink composition colored in each color is prepared and printed for each color. To form. At this time, the plasma treatment may be performed every time the color filters R, G, and B are formed. For example, after forming a red (R) pattern, it is preferable to form a green (G) or blue (B) pattern after further plasma treatment. That is, it is preferable to perform plasma treatment at least twice or more according to the number of times of pattern formation of the color filter layer 10B. Through the above steps, the laminated optical functional layer 10 is formed on the glass substrate 11 (FIG. 3).

  As described above, in the method for forming the laminated optical functional layer 10 according to the present embodiment, the surface of the polymerization type liquid crystal layer 10A formed on the glass substrate 11 is subjected to the plasma treatment, whereby the polymerization type liquid crystal layer 10A is formed. The surface is modified, and the adhesion of the color filter layer 10B to the polymerization type liquid crystal layer 10A can be adjusted to an appropriate size. Therefore, it is possible to prevent film residue and film peeling during film formation.

  Here, other examples of the surface treatment of the polymerization type liquid crystal layer 10A include a UV cleaning treatment using a low-pressure mercury lamp or the like. In this case, the bonds of the three-dimensionally crosslinked molecules are broken, and oxidation occurs. , Retardation is lowered or heat resistance is lowered. In the present embodiment, the surface modification can be performed without impairing the characteristics of the polymerization type liquid crystal layer 10A and the color filter layer 10B by plasma treatment.

  Further, in the step of forming the polymerizable liquid crystal layer 10A, a three-dimensional crosslinking process is performed on the polymerizable liquid crystal layer 10A-1, thereby forming a color filter layer 10B in a later step or forming a liquid crystal cell. It is possible to prevent the optical characteristics of the polymerization type liquid crystal layer 10A from being deteriorated due to the temperature change at this time. Furthermore, three-dimensional crosslinking can be promoted by performing a polymerization treatment (thermal polymerization) after the three-dimensional crosslinking treatment.

  Further, by forming the polymerization type liquid crystal layer 10A using a nematic liquid crystal material as shown in FIG. 2A, the major axis direction of the liquid crystal molecules is substantially aligned horizontally with respect to the substrate surface. It can be used as a phase difference film (A plate). Further, by using a nematic liquid crystal material as shown in FIG. 2B, a retardation film (positive C plate) in which the major axis direction of the liquid crystal molecules is oriented substantially perpendicular to the substrate surface. ).

  Further, by forming the polymerization type liquid crystal layer 10A using a cholesteric liquid crystal material as shown in FIG. 2C, a retardation film (negative C plate) having a selective reflection in the ultraviolet region, an ultraviolet reflecting film, It can be used as a color reflection plate having selective reflection in the visible light region, a heat ray cut plate having selective reflection in the infrared region, or the like.

  Further, by forming the polymerization type liquid crystal layer 10A using a hybrid alignment type liquid crystal material as shown in FIG. 2D, it can be used as, for example, an O-plate retardation film.

  Next, a modified example of the present invention will be described.

(Modification 1)
5A, FIG. 5B, FIG. 6A, and FIG. 6B are respectively adjacent to the polymerization type liquid crystal layer 10A (first optical functional layer) in the laminated optical functional layer 10. 2 shows an example of a second optical function layer formed in a manner described above.

  FIG. 5A functions as, for example, a spacer or a seal portion, and forms a column layer 24 made of, for example, a mixture of acrylic resin or epoxy resin. FIG. 5B shows, for example, a protective layer 25 that is provided to protect the polymerization type liquid crystal layer 10A and the color filter layer, and is composed of, for example, a mixture of acrylic resin or epoxy resin.

  FIG. 6A shows a case where a patterned light transmission layer 26 is formed, and is composed of, for example, a mixture of acrylic resin or epoxy resin. Specifically, the light transmission layer 26 is used for adjusting a cell gap in a liquid crystal display device having a reflection portion and a transmission portion inside a cell. FIG. 6B shows a case where a patterned transparent electrode layer 27 is formed.

  As described above, the second optical functional layer is not limited to the color filter layer 10B as shown in FIGS. 1 and 3, and an organic layer having another optical function or an inorganic layer such as a transparent electrode is formed. You may do it. Accordingly, when the optical functional layer formed on the polymerization type liquid crystal layer 10A is an organic layer as shown in FIGS. 5A, 5B, and 6A, the polymerization type liquid crystal is usually used. Although the adhesiveness with the layer is too high and a film residue is generated at the time of film formation, the plasma treatment can reduce the adhesiveness and prevent the film residual. On the other hand, when the optical functional layer is an inorganic layer as shown in FIG. 6B, the adhesion to the polymerization type liquid crystal layer is usually too low and film peeling occurs at the time of film formation, but plasma treatment is performed. Thereby, adhesiveness improves and film peeling can be prevented.

  The “optical function layer” in the present invention is not limited to the meaning that the layer itself has an optical function, but means a layer that contributes to some optical function related to the entire liquid crystal display device. Shall.

(Modification 2)
FIG. 7 shows a modification (polymerization type liquid crystal layer 11A) of the polymerization type liquid crystal layer 10A (first optical function layer) of the laminated optical function layer 10. As shown in the drawing, the polymerization type liquid crystal layer 11 </ b> A may be configured to be patterned on the alignment film 12. In this case, a flattening layer 28 for flattening the patterned polymerization liquid crystal layer 11A is provided. The planarizing layer 28 is made of, for example, a mixture of acrylic resin or epoxy resin.

  Next, examples of the present invention will be described.

(Example 1-1)
As Example 1-1, the laminated optical functional layer 10 as shown in FIG. 3 was formed. At this time, first, the following composition A was prepared using the nematic liquid crystal shown in Chemical Formula 1. On the other hand, the rubbing-treated alignment film 12 was formed on the glass substrate 11. However, as the alignment film 12, AL1254 (trade name; manufactured by JSR Corporation) was used.
[Composition A]
Formula 1: 20% by weight
IRGACURE907: 1% by weight
Megafuck R-08: 0.02% by weight
PGMEA: 78.98% by weight

  Next, the composition A was applied onto the alignment film 12 by a spin coating method, and then the solvent was removed by drying under reduced pressure (final ultimate vacuum 50 Pa). After that, a liquid crystal layer 10A-1 was formed on the alignment film 12 by performing an alignment process on a hot plate (90 ° C.) for 3 minutes.

Subsequently, a three-dimensional crosslinking process was performed by irradiating the liquid crystal layer 10A-1 with ultraviolet rays UV. At this time, an ultra-high pressure mercury lamp was used as the light source, and the illuminance was 20 mW / cm ² , the exposure time was 40 seconds, and the atmosphere was nitrogen (oxygen concentration 0.1% or less). Thereafter, heat treatment was performed for 60 minutes in an oven (220 ° C., oxygen concentration 1% or less) in a nitrogen atmosphere, whereby the liquid crystal layer 10A-1 was thermally polymerized to form a polymerization type liquid crystal layer 10A.

  The thickness of the polymerization type liquid crystal layer 10A thus formed was 1.1 μm when measured with a stylus type step gauge. Further, the front retardation was measured and found to be 110 nm. When tilted along the rubbing axis, the −50 ° retardation was 82 nm and the + 50 ° retardation was 81 nm. Therefore, it was confirmed that an A plate retardation film was formed.

  Next, plasma treatment was performed on the surface of the polymerization type liquid crystal layer 10A formed as described above. At this time, the plasma apparatus was treated with atmospheric pressure plasma using ADMASTER II-620d (Esquare). Also, CDA (clean dry air) gas flow rate: 150 ml / min, power: 2.0 kW, gap with substrate: 3.0 mm, nitrogen gas flow rate: 250 l / min, transport speed: 5 m / min.

  Next, a color filter layer 10B (color filters R, G, and B and a black matrix BM) is formed on the surface of the polymerized liquid crystal layer 10A subjected to plasma treatment by patterning using a photolithography method. The functional layer 10 was formed. About the formed color filter layer 10B, when the pattern was confirmed and the film thickness was measured by microscopic observation and a stylus type step gauge, the line width and film thickness were about the same as those formed on the raw glass. It was confirmed that Moreover, although the part which removed the film | membrane by the photolithographic method was observed by SEM (Scanning Electron Microscope: Scanning electron microscope), the film | membrane residue was not observed.

(Example 1-2)
As Example 1-2, the polymerization type liquid crystal layer 10A formed in the same manner as in Example 1-1 was exposed through a photomask, developed with methyl ethyl ketone, and patterned to obtain the pattern shown in FIG. A polymerization type liquid crystal layer 11A as shown in Modification 2 was formed. Thereafter, the surface of the formed polymerization liquid crystal layer 11A is subjected to plasma treatment in the same manner as in Example 1-1, and the planarizing layer 28 is formed thereon, thereby forming the laminated optical functional layer 10. did. When the film thickness was measured in the same manner as in Example 1-1 for the planarized layer 28 of Example 1-2 formed in this way, the film was formed uniformly, and film peeling and film residue were not observed. Not observed.

(Comparative Example 1-1)
As Comparative Example 1-1 of Example 1-1, a laminated optical functional layer was formed in the same manner as in Example 1-1 except that the surface of the formed polymerization liquid crystal layer was not subjected to plasma treatment. As a result, a film residue was generated in the pattern removal portion when the color filter layer was formed.

(Comparative Example 1-2)
As Comparative Example 1-2 of Example 1-2, a laminated optical functional layer was formed in the same manner as in Example 1-2 except that the surface of the formed polymerization liquid crystal layer was not subjected to plasma treatment. As a result, the film repelled when the planarizing layer was formed, and the film could not be formed successfully.

(Example 2-1)
As Example 2-1, the laminated optical functional layer 10 as shown in FIG. 3 was formed. First, using the nematic liquid crystal shown in Chemical Formula 1 and Chemical Formula 2, the following composition B was prepared, except that LX1400 (trade name: manufactured by Hitachi Chemical DuPont) was used as the alignment film 12. In the same manner as in Example 1-1, a polymerization type liquid crystal layer 10 </ b> A was formed on the alignment film 12.
[Composition B]
Formula 1: 20% by weight
Formula 2: 1% by weight
IRGACURE907: 1% by weight
Megafuck R-08: 0.02% by weight
PGMEA: 77.98% by weight

  The film thickness of the polymerization type liquid crystal layer 10A thus formed was measured by a stylus type step gauge and found to be 0.9 μm. Further, the front retardation was measured and found to be 90 nm, and when tilted along the rubbing axis, the −50 ° retardation was 60 nm and the + 50 ° retardation was 110 nm. Therefore, it was confirmed that a retardation film (O plate) in which the tilt angle of liquid crystal molecules was changed was formed.

  Next, plasma treatment is performed on the surface of the polymerization type liquid crystal layer 10A under the same conditions as in Example 1 except that the power is set to 3.0 kW, and the color filter layer 10B is formed on the surface by a photolithography method. did. However, in Example 2, every time the respective colors of the color filter, R, G, B, and black matrix BM are patterned, that is, a total of four plasma treatments are performed. About the formed color filter layer 10B, when the pattern was confirmed and the film thickness was measured by microscopic observation and a stylus type step gauge, the line width and film thickness equivalent to the film formed on the raw glass were formed. It was confirmed that Moreover, although the SEM observation was performed about the part from which the film | membrane was removed, the film | membrane remainder was not observed.

  Thus, when the pattern of each color of the color filter layer 10B is formed a plurality of times on the polymerization type liquid crystal layer 10A, it is preferable to perform plasma treatment every time the pattern is formed. By doing so, the surface of the layer already formed on the polymerization type liquid crystal layer 10A is also modified. Further, even on the surface of the polymerization type liquid crystal layer 10A that has been subjected to the plasma treatment once, the surface modification effect by the plasma treatment becomes small for the portion where the film has been removed in the pattern formation process. Furthermore, the effect of the surface modification gradually decreases with time. Therefore, by performing plasma treatment every time a pattern is formed, moderate adhesion can be maintained for a long time, and film residue can be effectively prevented.

(Examples 2-2 to 2-4)
In the same manner as in Example 2-1, after the plasma treatment was performed on the surface of the polymerization type liquid crystal layer 10A, in Example 2-2, the transparent protective layer 25 (FIG. 5B), in Example 2-3, The pillar layer 24 (FIG. 5A) was formed by photolithography. In Example 2-4, after forming the ITO layer, a positive resist was applied and removed with hydrochloric acid, and the transparent electrode layer 27 was patterned (FIG. 6B). As a result, the film was formed uniformly, and no film residue or film peeling was observed.

(Comparative Examples 2-1 to 2-4)
As Comparative Example 2-1 to Comparative Example 2-4 corresponding to Example 2-1 to Example 2-4, a laminated optical functional layer was formed without performing plasma treatment. About these comparative examples 2-1 to 2-4, the pattern was confirmed and the film thickness was measured in the same manner as in Example 2-1. In Comparative Example 2-1, the color filter layer was formed. In the comparative example 2-2, the transparent protective layer 25 was repelled, and the film could not be formed successfully. In Comparative Example 2-3, the remaining film of the pillar layer 24 was removed, and in Comparative Example 2-4, the transparent electrode layer 27 was peeled off.

  In this way, after forming the polymerization type liquid crystal layer, the surface is subjected to plasma treatment, the surface is modified, the adhesion of the optical functional layer to the polymerization type liquid crystal layer is controlled, and the film remaining at the time of film formation is controlled. It can be seen that film peeling can be prevented.

  Although the present invention has been described with reference to the embodiment and examples, the present invention is not limited to the above-described embodiment and the like, and various modifications are possible. For example, in the above embodiment and the like, the configuration of the liquid crystal display device has been specifically described, but other layers such as a diffusive layer and a layer having a reflective function may be provided as necessary. Good.

1 is a cross-sectional view illustrating a schematic configuration of a liquid crystal display device according to a first embodiment of the present invention. It is a figure which represents typically the arrangement structure of the liquid crystal molecule in the polymerization type liquid crystal layer shown in FIG. It is a cross-sectional enlarged view of the laminated optical functional layer shown in FIG. It is a figure showing the formation method of the laminated | stacked optical function layer shown in FIG. 1 in order of a process. 10 is a cross-sectional view illustrating a schematic configuration of a laminated optical functional layer according to Modification 1. FIG. 10 is a cross-sectional view illustrating a schematic configuration of a laminated optical functional layer according to Modification 1. FIG. 10 is a cross-sectional view illustrating a schematic configuration of a laminated optical functional layer according to Modification 2. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device, 10 ... Laminated optical functional layer, 10A ... Polymerization type liquid crystal layer, 10B ... Color filter, 11, 18 ... Glass substrate, 12, 14, 16 ... Alignment film, 13, 17 ... Electrode, 15 ... Liquid crystal layer, 19 ... retardation plate, 20, 21 ... polarizing plate, 22 ... light source, 23 ... reflector.

Claims (12)

Forming a first optical functional layer made of an alignment-controlled polymerization type liquid crystal on a transparent substrate;
Applying plasma treatment to the surface of the first optical functional layer;
Forming a second optical functional layer on the surface of the first optical functional layer that has been subjected to the plasma treatment. A method for producing a laminated optical functional layer, comprising: The method for producing a laminated optical functional layer according to claim 1, wherein the plasma treatment is an atmospheric pressure plasma treatment. The step of forming the first optical functional layer includes:
A step of subjecting the liquid crystal layer having polymerizability to an alignment regulation treatment;
A step of performing a three-dimensional crosslinking treatment by irradiating an energy ray to the liquid crystal layer subjected to the alignment regulation treatment;
The method for producing a laminated optical functional layer according to claim 1, further comprising: subjecting the liquid crystal layer subjected to the three-dimensional crosslinking treatment to a heat treatment to perform heat polymerization. The method for producing a laminated optical functional layer according to claim 1, wherein the polymerizable liquid crystal layer includes a nematic liquid crystal. The method for producing a laminated optical functional layer according to claim 1, wherein the polymerizable liquid crystal layer contains cholesteric liquid crystal. The method for producing a laminated optical functional layer according to claim 1, wherein the polymerizable liquid crystal layer is configured such that a tilt angle of liquid crystal molecules changes in a thickness direction thereof. The method for producing a laminated optical functional layer according to claim 1, wherein the second optical functional layer includes a color filter. The method for producing a laminated optical functional layer according to claim 1, wherein the second optical functional layer includes a black matrix. The method for producing a laminated optical functional layer according to claim 1, wherein the second optical functional layer is composed of an organic layer. The method for producing a laminated optical functional layer according to claim 1, wherein the second optical functional layer is a transparent electrode. After the step of forming the first optical functional layer,
The method for producing a laminated optical functional layer according to claim 1, wherein the first optical functional layer is patterned, and a plasma treatment is performed on the surface of the patterned first optical functional layer. After performing plasma treatment on the patterned first optical functional layer,
The method for producing a laminated optical functional layer according to claim 11, wherein a planarizing layer for planarizing the first optical functional layer is formed as the second optical functional layer.

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