JPH0746161B2 - Color filter substrate and ferroelectric liquid crystal element - Google Patents

Description

TECHNICAL FIELD The present invention relates to a color filter substrate and a ferroelectric liquid crystal device used for a liquid crystal display device, a liquid crystal-optical shutter array, etc., and more specifically, initial alignment of liquid crystal molecules. The present invention relates to a color filter substrate having a color filter in which a uniform monodomain liquid crystal phase having no alignment defect is obtained by improving the state, and display and driving characteristics are improved, and a ferroelectric liquid crystal device using the same.

[Prior Art] Examples of conventional liquid crystal elements include M.Sc.
hadt) and W. Helfrich's "Applied Physics Letters"("Applied
Physics Letters ") Volume 4, Issue 4 (Published February 15, 1971), pages 127-128," Voltage Dependant Optical Activity of a Twisted Nematic Liquid Crystal " “Voltag
e Dependent Optical Activity of a Twisted Nematic
Liquid crystal ") is known, which uses twisted nematic liquid crystal. This TN liquid crystal is a crosstalk during time-division driving using a matrix electrode structure with high pixel density. However, the number of pixels is limited because of the problem of occurrence of.

In addition, a display element of a type in which a switching element using a thin film transistor is connected to each pixel and switching is performed for each pixel is known, but a step of forming a thin film transistor on a substrate is extremely complicated, and a large area display element is used. There are problems that are difficult to create.

To solve these problems, Clar (Clar
Ferroelectric liquid crystal devices have been proposed in U.S. Pat. No. 4,367,924 by K) et al.

FIG. 2 schematically shows an example of a cell for explaining the operation of the ferroelectric liquid crystal. 21a and 21b are In ₂ O ₃ and SnO ₂
A substrate (glass plate) covered with a transparent electrode made of a thin film such as ITO or Indium Tin Oxide (SmC) in which a plurality of liquid crystal molecular layers 22 are aligned so as to be perpendicular to the glass surface.
^* Phase or SmH ^* phase liquid crystal is enclosed. The thick line 23 represents a liquid crystal molecule.
_{Has a} dipole moment (P _⊥ ) 24 in a direction orthogonal to its molecule. When a voltage above a certain threshold is applied between the electrodes on the substrates 21a and 21b, the helical structure of the liquid crystal molecules 23 is unraveled, and all the dipole moments (P _⊥ ) 24 are oriented in the electric field direction. Can be changed. The liquid crystal molecules 23 have an elongated shape, and exhibit refractive index anisotropy in the direction of the short axis of the liquid crystal molecules 23. Therefore, for example, if polarizers arranged in a crossed Nicol position above and below the glass surface are placed. It is easily understood that the liquid crystal optical modulation element has optical characteristics that change depending on the polarity of voltage application.

The liquid crystal cell preferably used in the ferroelectric liquid crystal device of the present invention can be made sufficiently thin (for example, 10 μm or less). As the liquid crystal phase becomes thinner like this,
As shown in Fig. 3, even when no electric field is applied, the helical structure of the liquid crystal molecule unwinds and becomes a non-helical structure, and its dipole moment Pa or Pb is either upward (34a) or downward (34b). To take. In a cell like this,
As shown in FIG. 3, electric fields Ea of different polarities and above a certain threshold value
Or, when Eb is applied, the dipole moment changes upward 34a or downward 3a corresponding to the electric field vector of the electric field Ea or Eb.
4b, and the liquid crystal molecules are aligned in either the first stable state 33a or the second stable state 33b accordingly.

As described above, there are two advantages of using such a ferroelectric liquid crystal as an optical modulation element. The first is that the response speed is extremely fast, and the second is that the alignment of the liquid crystal molecules has bistability. The second point is, for example, the third
Explaining further by the figure, when the electric field Ea is applied, the liquid crystal molecules are aligned in the first stable state 33a, but this state is stable even when the electric field is cut off. When a reverse electric field Eb is applied, the liquid crystal molecules are oriented in the second stable state 33b and the orientation of the molecules is changed. However, even when the electric field is cut off, the liquid crystal molecules remain in this state. Further, as long as the applied electric field Ea does not exceed a certain threshold value, the respective alignment states are maintained.
In order to effectively realize such a high response speed and bistability, it is preferable that the cell is as thin as possible.

In order for this ferroelectric liquid crystal element to exhibit a predetermined driving characteristic, the ferroelectric liquid crystal disposed between the pair of parallel substrates must be
Regardless of the applied state of the electric field, it is necessary that the molecular arrangement is such that conversion between the two stable states described above effectively occurs. For example, regarding a ferroelectric liquid crystal having a chiral smectic phase, a liquid crystal molecular layer of the chiral smectic phase is perpendicular to the substrate surface, and thus a region (monodomain) in which the liquid crystal molecular axes are aligned substantially parallel to the substrate surface is formed. Need to However, in the conventional ferroelectric liquid crystal device, the alignment state of the liquid crystal having such a monodomain structure was not always formed satisfactorily, and therefore, the actual condition was that sufficient characteristics were not obtained.

FIG. 4 shows a cross-sectional view of a conventional ferroelectric liquid crystal element, and FIG. 5 is a schematic explanatory view showing a state of alignment defects appearing in the conventional ferroelectric liquid crystal element.

That is, the conventional ferroelectric liquid crystal element 40 shown in FIG.
It has a pair of parallel substrates 41 and 42, and stripe-shaped transparent electrodes 43 and 44 having a matrix electrode structure are provided on the substrates 41 and 42, respectively.

Generally, a color filter is composed of red (R), green (G), and blue (B) dyes or a layer containing the dyes. However, since the film thickness of each dye layer is different regardless of the forming method, 2000Å A step A of about 1 μm is formed. As a result, when the alignment control is performed by utilizing the temperature lowering process, the above-mentioned step A causes the alignment defect in the ferroelectric liquid crystal 47 with the step A as a boundary. Also, this step A
On the substrates 41 and 42 on which the alignment control films 45 and 46 are present, respectively.
By providing the step, a step C formed corresponding to the step A also occurs in this alignment control film in the thickness of almost the pixel, and an alignment defect occurs in the ferroelectric liquid crystal 47 in the same manner as described above.

FIG. 5 is a sketch of the ferroelectric liquid crystal device observed with a crossed Nicols polarization microscope. White lines 51 in the drawing correspond to the lines of the spacer (not shown) used for the liquid crystal device, and the line 52 And 53 are observed corresponding to the step C on the substrate 41 in FIG. Further, a portion 54 in the figure is a ferroelectric liquid crystal sandwiched between opposed electrodes. A large number of blade lines 55 appearing in the polarization microscope represent alignment defects of the ferroelectric liquid crystal.

If there is a certain level difference on the surface in contact with the ferroelectric liquid crystal as described above, an alignment defect is generated from the level difference and the monodomain formation of the ferroelectric liquid crystal is hindered.

[Problems to be Solved by the Invention] The present inventors have found that when such a step on a substrate, especially a color filter is internally provided in a ferroelectric liquid crystal element, the interval between pixels exceeds 5 μm. It was clarified by experiments that the step difference generated at the position causes a significant alignment defect with respect to the ferroelectric liquid crystal.

An object of the present invention is to provide a color filter substrate and a ferroelectric liquid crystal element capable of preventing the occurrence of the above-mentioned alignment defects and sufficiently exhibiting the high-speed response and the memory effect characteristics originally possessed by the ferroelectric liquid crystal element. To provide.

[Means for Solving Problems] The inventors of the present invention have focused on the initial orientation in the temperature decreasing process in which the ferroelectric liquid crystal transitions from the isotropic phase (high temperature state) to the liquid crystal phase (low temperature state). The present inventors have found a ferroelectric liquid crystal device having a structure capable of satisfying both the operating characteristics of the device based on the bistability of the dielectric liquid crystal and the monodomain property of the liquid crystal layer.

The liquid crystal element of the present invention is based on such knowledge, and more specifically, there is no step that induces an alignment defect on the surface in contact with the liquid crystal layer, that is, the film thickness of the liquid crystal layer changes abruptly. It is characterized in that the initial orientation in the temperature-lowering process is kept in a good state by eliminating it, and a monodomain without orientation defects is formed.

That is, the present invention provides a color filter unit obtained by providing, on a substrate, a film of a colored resin obtained by dispersing a coloring material in a polyamide resin having a photosensitive group in the molecule, and exposing and curing the film. When a plurality of color filter units are provided and the space between the adjacent color filter units is α (μm), the relationship of 0 ≦ α ≦ 5 μm is satisfied, and the protective layer is formed on the color filter layer formed by arranging the plurality of color filter units. And a pattern-shaped transparent electrode which is sequentially laminated.

Further, the present invention has a color filter layer formed by sandwiching a ferroelectric liquid crystal between a pair of substrates on which transparent electrodes are formed and arranging a plurality of color filter units between at least one transparent electrode and the substrate. In the ferroelectric liquid crystal element, the color filter layer is formed by providing a film of a colored resin in which a coloring material is dispersed in a polyamide resin having a photosensitive group in the molecule, exposing the film, and curing the film. When the distance between adjacent color filter units is α (μm), the relationship of 0 ≦ α ≦ 5 μm is established, and a protective layer, a patterned transparent electrode and an alignment control film are sequentially laminated on the color filter layer. It is a ferroelectric liquid crystal device characterized by the following.

Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the basic structure of a ferroelectric liquid crystal device according to the present invention. In FIG. 1, a ferroelectric liquid crystal element 1 has substrates 2 and 3 using transparent plates such as glass plates or plastic plates, and a ferroelectric liquid crystal 4 is sandwiched between them. Striped pattern-shaped transparent electrodes 5 and 6 forming a matrix electrode structure are arranged on each of the substrates 2 and 3, and alignment control films 7 and 8 are formed on the transparent electrodes. Each of the R (red), G (green), and B (blue) color filters is formed with a coloring material concentration set in advance so that desired spectral characteristics can be obtained with the same film thickness. On the other hand, in order to perform more flattening, if necessary, a light shielding layer 10 is formed in the recess between the color filters, and a protective film or a flattening film 9 is further formed thereon. One pixel is composed of three color filter units consisting of R, G, and B.

In the substrate having the above structure, the thickness of the color filter is set to be almost the same, and the interval between pixels is 5 μm.
Since the step difference due to the depression is corrected by controlling the height to m or less, the substrate surface can be kept substantially flat even if the transparent electrode and the alignment control film are sequentially formed on the pixel.

In the present invention, the step of the color filter substrate can be set to 1000 Å or less by the above-mentioned flattening, but it is preferably set to 500 Å or less. If this step exceeds 1000Å, in other words, the liquid crystal element using the non-flattening layer in which the distance between each pixel is set to exceed 5 μm, the alignment defect of the edge line shown in FIG. 5 is generated. It will be.

The color filter suitable for the present invention may be a method in which the film thickness of each pixel can be set to be substantially the same, but the effect as the present invention is particularly large, and a fine pattern can be formed by a simple manufacturing process. Can be formed,
Further, the following method, which is a color filter excellent in various characteristics such as heat resistance, light resistance, and solvent resistance in addition to mechanical characteristics, is preferable.

That is, the optimum color filter for the present invention is a method of forming a color resin by repeating a photolithography process of a color resin in which a color material is dispersed in a low temperature curable polyamide resin having a photosensitive group in a molecule. .

More specifically, as a low temperature curable polyamide resin having a photosensitive group in its molecule which forms a colored resin layer of a color filter (hereinafter referred to as a photosensitive polyamide resin), What you get,
For example, a cured film can be formed by heat of about 150 ° C x 30 minutes. For example, an aromatic polyamide resin that has a photosensitive group in its molecule, especially for specific light absorption in the visible light wavelength range (400 to 700 nm). Those that do not have the characteristics (light transmittance of about 90% or more) are preferable. From this viewpoint, an aromatic polyamide resin is particularly preferable.

Further, the photosensitive group in the present invention may be an aromatic chain having a photosensitive hydrocarbon unsaturated group as shown below, for example, (In the formula, R ₁ is CHX = CY-COO-Z-, X is -H or -C ₆ H ₅ , Y is -H or -CH ₃ , Z is-or an ethyl group or a glycidyl group.) (Wherein Y represents -H or CH ₃₎ (In the formula, R ₂ is CHX = CY-CONH-, CH ₂ = CY-COO- (CH ₂ ) ₂ -OCO
-Or CH ₂ = containing one or more of CY-COO-CH _2- , X and Y have the above meanings) (In the formula, R ₃ represents H-, an alkyl group or an alkoxy group) Etc.

Specific examples of aromatic polyamide resins having these groups in the molecule include "Lisocoat PA-1000" (trade name, manufactured by Ube Industries, Ltd.).

Generally, there are few photosensitive resins used in the photolithography process, which have excellent mechanical properties, heat resistance, light resistance, solvent resistance, and the like, although there are differences depending on their chemical structures. On the other hand, the photosensitive polyamide resin of the present invention is a resin system having excellent durability in terms of chemical structure, and the durability of the color filter formed using these is also very good. Become. In particular, it exhibits excellent performance against heat resistance during sputter formation of a transparent conductive film, which may be a problem as a color filter for a ferroelectric liquid crystal element, and damage to the color filter due to an inner spacer during liquid crystal element assembly. .

The coloring material forming the colored resin layer of the color filter in the present invention is not particularly limited as long as it can obtain desired spectral characteristics among organic pigments, inorganic pigments, dyes and the like. In this case, each material can be used alone or as a mixture of some of them. However, when a dye is used, the performance of the color filter is governed by the durability of the dye itself. However, when the resin system of the present invention is used, the performance is superior to that of an ordinary dyed color filter. Can be formed. Therefore, considering the color characteristics and various performances of the color filter, the organic pigment is most preferable as the coloring material.

Organic pigments include azo pigments such as soluble azo pigments, insoluble azo pigments and condensed azo pigments, phthalocyanine pigments,
And condensed polycyclic pigments containing indigo, anthraquinone, perylene, perinone, dioxazine, quinacridone, isoindolinone, phthalone, methine / azomethine, other metal complex, or some of these A mixture of these is used.

In the present invention, the colored resin used to form the colored resin layer is the photosensitive polyamide resin solution, and each of the colored materials having desired spectral characteristics at the same film thickness of each color is approximately 10 to 50%. It is blended in a ratio of 1, and is sufficiently dispersed by ultrasonic waves or a three-roll mill, and then, those having a large particle size are preferably removed by a filter having a size of 1 μm or less.

The colored resin layer of the color filter in the present invention is formed by applying the colored resin on a substrate by a coating device such as a spinner or a roll coater, and forming it in a pattern by a photolithography process, the layer thickness of which has a desired spectral characteristic. Normally, 0.5 to 5 with the same film thickness for each color.
About μm, preferably about 0.5 to 1.5 μm is desirable.

If it is necessary to further increase the adhesiveness between the colored resin layer and the underlying substrate, either apply a thin coating of the silane coupling agent or the like on the substrate beforehand and then form the colored resin pattern, or It is more effective to form the color filter by using a material to which a small amount of a silane coupling agent or the like is added.

The colored resin layer of the color filter of the present invention is composed of a good material having sufficient durability itself, but particularly for protecting the colored resin layer from various environmental conditions, or In order to flatten the color filter surface, polyamide,
Polyimide, polyurethane, polycarbonate, silicon-based organic resins and inorganic films such as Si ₃ N ₄ , SiO ₂ , SiO, Al ₂ O ₃ , Ta ₂ O ₃ can be applied by spin coating, roll coating, or vapor deposition. According to this, it can be provided as a protective film or a flattening film.

In this case, since the color filter surface has a more stepless shape, it is more suitable for eliminating the alignment defect of the ferroelectric liquid crystal which is the object of the present invention. Further, the film thickness of the protective film 9 can determine the film thickness of the ferroelectric liquid crystal 4, and therefore varies depending on the type of liquid crystal material and the required response speed, but generally 0.2 μm to 20 μm,
It is preferably set in the range of 0.5 μm to 10 μm.

Furthermore, in some cases, in order to improve the display characteristics,
In order to fill in the gaps between the pixels and to reduce the step generated between the pixels, a light-shielding layer is formed between the pixels by a metal thin film having a light-shielding ability such as chromium or aluminum by a vapor deposition method or in a photosensitive polyamide resin. A light-shielding resin layer in which a material having a light-shielding ability such as carbon black, a black composite oxide pigment, and metal powder is dispersed can be formed by a coating method.

Examples of the material of the orientation control film used in the present invention include polyvinyl alcohol, polyimide, polyamideimide, polyester, polycarbonate, pyrivinylacetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, cellulose resin, melamine resin, and urea. Resins such as resin and acrylic resin, photosensitive polyimide, photosensitive polyamide, cyclic rubber photoresist, phenol novolac photoresist or electron beam photoresist (polymethylmethacrylate, epoxidized-1,4-polybutadiene, etc.), etc. It can be selected and formed. Although the orientation control film 7 depends on the film thickness of the ferroelectric liquid crystal, it is generally set in the range of 10Å to 1 μm, preferably 100Å to 3000Å.

A particularly suitable liquid crystal material for use in the present invention is a liquid crystal having bistability and having ferroelectricity. Specifically, the chiral smectic C phase (Sm
Use C ^* ), H phase (SmH ^* ), I phase (SmI ^* ), J phase (SmJ ^* ), K phase (SmK ^* ), G phase (SmG ^* ) or F phase (SmF ^* ) liquid crystal You can

About this ferroelectric liquid crystal, "LE JOURNAL DE PHYSIQUE
LETTRES ") 1975, 36 (L-69)," Ferroelectric Liquid Crystals "(" Ferroelectric
Liquid Crystals ”);“ Applied Physics
"Applied Physics Letters" 1980, 36
(11), "Sub-micro second bistable
Electro-Optic Switching In Liquid Crystals "(" Submicro Second Bistable Elect
rooptic Switching in Liquid Crystals ");" Solid State Physics "1981 16 (141)," Liquid Crystals ", etc.,
In the present invention, the ferroelectric liquid crystals disclosed in these can be used.

Specific examples of the ferroelectric liquid crystal include, for example, desiloxybenzylidene-p'-amino-2-methylbutyl cinnamate (DOBAMBC), hexyloxybenzylidene-p'-
Amino-2-chloropropyl cinnamate (HOBACP
C), 4-o- (2-methyl) -butylresorcylidene-4'-octylaniline (MBRAS).

When an element is formed using these materials, since the liquid crystal compound is maintained in a temperature state in which it becomes a chiral smectic phase, the element can be supported by a block or the like in which a heater is embedded, if necessary.

"Function" In the color filter substrate of the present invention and the ferroelectric liquid crystal element using the same, the color filters of each pixel are formed to have substantially the same film thickness, and the interval α (μm) between the color filters of each adjacent pixel is Since 0 ≦ α ≦ 5 μm, the flatness of the substrate is good, and there is no step on the surface in contact with the liquid crystal phase. By gradually cooling in the temperature decreasing process of transition, the liquid crystal phase region gradually expands to form a uniform monodomain liquid crystal phase.

For example, the above-mentioned DOBAMB which shows a ferroelectric liquid crystal phase as a liquid crystal.
Explaining with C as an example, when gradually cooling from the isotropic phase of DOBAMBC, it undergoes a phase transition to a smectic A phase (SmA phase) at about 115 ° C. At this time, when the substrate is subjected to an alignment treatment such as rubbing or SiO ₂ oblique vapor deposition, a monodomain in which the molecular axes of liquid crystal molecules are parallel to the substrate and aligned in one direction is formed. Further, as the cooling proceeds, a phase transition to a chiral smectic C phase (SmC ^* phase) occurs at a specific temperature of about 90 to 75 ° C. depending on the thickness of the liquid crystal layer. If the thickness of the liquid crystal layer is about 2 μm or less, SmC ^*
The phase spiral unravels and exhibits bistability.

[Examples] Hereinafter, the present invention will be described more specifically with reference to Examples.

Example 1 FIGS. 6A to 6F are process diagrams showing a process of forming color pixels of R, G, and B colors.

First, a blue colored resin material [Heliogen Blue L7080 (trade name, manufactured by BASF, CI No. 74160), which can obtain desired spectral characteristics, is formed on a Corning # 7059 glass substrate 61 with a photosensitive polyamide. Resin PA-10
00C (Brand name, Ube Industries, Polymer content = 10%, solvent:
N-methyl-2-pyrrolidone, pigment: polymer = 1: 2 blended) to prepare a photosensitive colored resin material] and applied to a film thickness of 1.5 μm by a spinner coating method to form a colored resin layer 62. did. (See FIG. 6 (a)) Next, the colored resin layer 62 was prebaked at 80 ° C. for 30 minutes and then exposed with a high pressure mercury lamp through a photomask 63 corresponding to the pattern shape to be formed. . (See FIG. 6 (b)) After the exposure, as shown in FIG. 6 (c), a dedicated developer (N-methyl-2-) that dissolves only the unexposed portion of the colored resin layer 62 having the photo-cured portion 62a. A developing solution containing pyrrolidone as a main component is developed by using ultrasonic waves, and a dedicated rinse liquid (for example, a rinse liquid containing isopropyl alcohol as a main component) is used.
And then post-baked at 150 ° C for 30 minutes to obtain a blue patterned colored resin layer having a pattern shape.
64 formed. (See FIG. 6 (d)) Subsequently, a green colored resin material [Lionol Green 6YK (trade name, manufactured by Toyo Ink Co., Ltd., C .
I.No.74265) is dispersed in PA-1000C (trade name, manufactured by Ube Industries, Ltd., polymer content = 10%, solvent: N-methyl-2-pyrrolidone, pigment: polymer = 1: 2 blended) to form a photosensitive film. In the same manner as described above, except that a colored resin material having a property of “a” is used, a green patterned resin layer 65 is formed at a predetermined position on the substrate with a gap of 5 μm or less from the blue colored resin layer.

Furthermore, as a third color, a red colored resin material [Irgazin Red BPT (trade name, manufactured by Ciba-Geigy Co., CINo. .71127) to PA-1000C
(Product name, manufactured by Ube Industries, Polymer content = 10%, solvent: N-
Methyl-2-pyrrolidone, pigment: polymer = 1: 2 blended)
Except that the photosensitive colored resin material prepared by dispersing is prepared in the same manner as described above.
Is formed at a predetermined position on the substrate with a gap between the blue colored resin layer and the green colored resin layer set to 5 μm or less, and a three-color stripe of R (red), G (green), and B (blue) is formed. A colored pattern was obtained. (See FIG. 6 (e)) Next, on the glass substrate on which the three-color coloring pattern is formed,
A black colored resin material [carbon black (C.
I.No.77266) was dispersed in PA-1000C (polymer content = 10%, pigment: polymer = 1: 4 blended) to prepare a photosensitive colored resin material] A light-shielding layer 67 having a light-shielding pattern was formed so as to match the gap between pixels. As a result, the interval α (μm) between each pixel is 0 ≦ α ≦ 5 μm
I was able to reduce it to the range of.

On the color filter pattern obtained in this way,
The same transparent resin material used for the colored resin material as the protective film or the flattening film 68 [PA-1000C (trade name, manufactured by Ube Industries, polymer content = 10%, solvent: N-methyl-2-pyrrolidone) Was formed by a spinner coating method to a film thickness of about 0.5 μm. (See FIG. 6 (f)) As described above, it was possible to form the coplanarized color filter substrate.

Next, as shown in FIG. 1, ITO was formed into a film with a thickness of 500 Å by a sputtering method to form a transparent electrode 5. A polyimide forming solution (Hitachi Chemical Industries "PIQ") was applied as an orientation control film 7 on this with a spinner rotating at 3000 rpm.
Heating was performed at 0 ° C. for 30 minutes to form a 2000 Å polyimide film. Then, the surface of this polyimide coating film was rubbed.

The color filter substrate thus formed and the opposing substrate 3 were attached to each other to form a cell set, and a ferroelectric liquid crystal was injected and sealed to obtain a liquid crystal element. When this liquid crystal element was observed with a crossed Nicols polarization microscope, it was confirmed that the liquid crystal molecules inside did not have alignment defects.

Comparative Example 1 The photosensitive polyamide resin used in the colored resin material of Example 1 was replaced with "Photo Nice" UR- which is a photosensitive polyimide resin.
3100 (trade name, manufactured by Toray Industries, Inc., solid content = 17%, solvent: N-
Patterning was performed using a dedicated developer (“DV-140”) and a dedicated rinse (isopropyl alcohol) instead of methyl-2-pyrrolidone / methylcellosolve mixed system.
A three-color striped color filter of R (red), G (green), and B (blue) was obtained in the same manner as in Example 1 except that the post-baking treatment was performed at 30 ° C. for 30 minutes.

The color filter obtained in this manner has a lower affinity for the resin and the pigment than the case of Example 1, and is formed using a colored resin material in which the dispersion state is inferior, so that the surface flatness is inferior. It was a thing.

Further, the color filter was inferior in transparency due to the characteristics of the resin.

Further, using the obtained color filter substrate, a ferroelectric liquid crystal element was formed in the same manner as in Example 1 and observed with a crossed Nicols polarization microscope. A defective portion was recognized, which affected the display characteristics, and the display contrast at this time was 0.4 times lower than the display contrast obtained in Example 1 described above.

Comparative Example 2 The photosensitive polyamide resin used for the colored resin material of Example 1 was replaced with "Photorec" RFG-1 which is a photosensitive acrylic resin.
0 (Brand name, Sekisui Fine Chemical Co., Ltd., solid content = 1)
0%, solvent: cyclohexane) instead of a dedicated developer (MEK
Patterning is performed using a developing solution containing as a main component) and a dedicated rinsing liquid (rinsing liquid containing MIBK as the main component) at 180 ° C, 30 ° C.
A three-color striped color filter of R (red), G (green), and B (blue) was obtained in the same manner as in Example 1 except that the post-baking treatment was performed for 1 minute.

The color filter obtained in this manner has a lower affinity for the resin and the pigment than the case of Example 1, and is formed using a colored resin material in which the dispersion state is inferior, so that the surface flatness is inferior. It was a thing.

Further, the color filter was inferior in durability due to the characteristics of the resin.

Further, using the obtained color filter substrate, a ferroelectric liquid crystal element was formed in the same manner as in Example 1 and observed with a crossed Nicols polarization microscope. A defective part was recognized, which affected the display characteristics. The display contrast at this time was 0.3 times lower than the display contrast obtained in Example 1 described above.

Comparative Example 3 The photosensitive polyamide resin used in the colored resin material of Example 1 was replaced with 0DUR-110WR (trade name, manufactured by Tokyo Ohka Co., Ltd., solvent: xylene), which is a negative resist for deep ultraviolet rays. After exposure with ultraviolet light, R (red), G (red) and G were obtained in the same manner as in Example 1 except that patterning was performed using a dedicated developing solution and a dedicated rinsing solution, and a post-baking treatment was performed at 180 ° C. for 30 minutes.
A three-color striped color filter of (green) and B (blue) was obtained.

The color filter obtained in this manner has a lower affinity for the resin and the pigment than the case of Example 1, and is formed using a colored resin material in which the dispersion state is inferior, so that the surface flatness is inferior. It was a thing.

Further, the color filter was inferior in durability due to the characteristics of the resin.

Further, using the obtained color filter substrate, a ferroelectric liquid crystal element was formed in the same manner as in Example 1 and observed with a crossed Nicols polarization microscope. A defective part was recognized, which affected the display characteristics. The display contrast at this time was 0.4 times lower than the display contrast obtained in Example 1 described above.

Comparative Example 4 The photosensitive polyamide resin used in the colored resin material of Example 1 was added to the photosensitive PVA resin FR-14 (trade name, manufactured by Fuji Chemical Industry Co., Ltd., solvent: water) with a diazo compound added. Instead of the above, develop with water and pattern with rinse,
A three-color striped color filter of R (red), G (green), and B (blue) was obtained in the same manner as in Example 1 except that the post-baking treatment was performed at 30 ° C. for 30 minutes.

The color filter obtained in this manner has a lower affinity for the resin and the pigment than the case of Example 1, and is formed using a colored resin material in which the dispersion state is inferior, so that the surface flatness is inferior. It was a thing.

Further, the color filter was inferior in durability due to the characteristics of the resin.

Further, using the obtained color filter substrate, a ferroelectric liquid crystal element was formed in the same manner as in Example 1 and observed with a crossed Nicols polarization microscope. A defective part was recognized, which affected the display characteristics. The display contrast at this time was 0.3 times lower than the display contrast obtained in Example 1 described above.

Comparative Example 5 In Example 1, a three-color color filter was formed by using a non-photosensitive colored polyimide resin instead of using the photosensitive colored polyamide resin.

That is, a blue colored polyimide resin material [Heliogen Blue L7080 (trade name, manufactured by BASF, CI No. 74160)] is applied on a glass substrate by Semicofine SP-910.
(Product name, Toray, solid content = 22%, pigment: polymer =
The colored resin material prepared by dispersing 1: 2) was applied to a film thickness of 2.0 μm by a spinner coating method. Next, the colored resin layer was dried at 150 ° C. for 30 minutes and then heated at 200 ° C. for 30 minutes.

After that, a positive resist [OFPR-2 (trade name, manufactured by Tokyo Ohka Co., Ltd.)] is spinner coated on the blue layer, prebaked at 80 ° C. for 20 minutes, and then a pattern mask corresponding to the pattern shape to be formed is formed. Via a high pressure mercury lamp.

After completion of the exposure, the resist is developed with an alkali developing solution, the blue layer is etched, the resist is then stripped with acetone, and a blue colored resin film having a pattern shape is formed by heating and baking at 250 ° C. for 30 minutes. Formed.

Next, on the glass substrate on which the blue coloring pattern is formed,
Second color green colored polyimide resin material [Lionol Green 6YX (trade name, manufactured by Toyo Ink, CI No. 74265)] is semicofine (trade name, manufactured by Toray, solid content = 22%, pigment: polymer) = 1: 2 formulation) was used to form a green colored pattern at a predetermined position on the substrate in the same manner as above.

Further, on the substrate on which the blue and green patterns are formed in this way, as a third color, a red colored polyimide resin material [Irgazin Red BPT (trade name, manufactured by Ciba-Geigy, (CINo.71127)
Semicofine (trade name, manufactured by Toray, solid content = 22%,
Pigment: Polymer = 1: 2 blended), and a red colored pattern is formed at a predetermined position on the substrate in the same manner as above except that a colored resin material prepared by dispersing is used.
A three-color striped color filter of (green) and B (blue) was obtained.

The color filter obtained in this manner has a lower affinity for the resin and the pigment than the case of Example 1, and is formed using a colored resin material in which the dispersion state is inferior, so that the surface flatness is inferior. It was a thing.

Further, the color filter was inferior in transparency due to the characteristics of the resin. Furthermore, since a resist process for patterning is required for each color formation, it is a very complicated process and the productivity is poor.

Subsequently, using the obtained color filter substrate, a ferroelectric liquid crystal element was formed in the same manner as in Example 1 and observed with a crossed Nicols polarization microscope. Alignment defects were observed, which affected the display characteristics. The display contrast at this time was 0.2 times lower than the display contrast obtained in Example 1 described above.

[Effects of the Invention] As described above, according to the present invention, there is no difference in the film thickness of the color filter layer on the substrate, and each pixel interval α (μm)
By arranging so that it falls within the range of 0 ≦ α ≦ 5 μm and further providing a light-shielding layer, a protective film, and a flattening film as necessary, it is possible to eliminate minute steps that occur between each pixel of the color filter. Therefore, it is possible to provide a ferroelectric liquid crystal element which can prevent the occurrence of alignment defects and can sufficiently exhibit the characteristics of the ferroelectric liquid crystal.

Furthermore, according to the present invention, excellent mechanical strength, and
It becomes possible to manufacture a color filter part having a fine pattern with excellent properties such as heat resistance, light resistance, solvent resistance, etc. by a simple manufacturing process. It can be provided easily.

[Brief description of drawings]

FIG. 1 is a sectional view showing the basic structure of a ferroelectric liquid crystal element according to the present invention, FIGS. 2 and 3 are perspective views schematically showing the ferroelectric liquid crystal used in the present invention, and FIG. Is a cross-sectional view of a conventional ferroelectric liquid crystal device, FIG. 5 is a schematic explanatory view showing a state of alignment defects appearing in a conventional ferroelectric liquid crystal device, and FIGS. 6 (a) to 6 (f) are drawings of the present invention. FIG. 6 is a process diagram illustrating a process of forming color pixels. 1,40 …… Ferroelectric liquid crystal element 2,3,41,42,61 …… Substrate 4,47 …… Ferroelectric liquid crystal 5,6,43,44 …… Transparent electrode 7,8,45,46… Alignment control film 9,48,68 Protective film (flattening film) 10,67 Shield layer

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Miki Tamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yu Kamio 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Nobuyuki Sekimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-60-237403 (JP, A) JP-A-61-260224 (JP) , A) JP 61-166523 (JP, A) JP 60-2725 (JP, A)

Claims (4)

[Claims] 1. A plurality of color filter units obtained by providing a film of a colored resin in which a coloring material is dispersed in a polyamide resin having a photosensitive group in a molecule on a substrate, and exposing and curing the film. When the distance between the adjacent color filter units is α (μm), the relationship of 0 ≦ α ≦ 5 μm is satisfied, and a protective layer and a protective layer are formed on the color filter layer formed by arranging a plurality of the color filter units. A color filter substrate, which is formed by sequentially laminating patterned transparent electrodes. 2. The color filter substrate according to claim 1, wherein the polyamide resin is a resin having an aromatic group. 3. A ferroelectric having a color filter layer formed by sandwiching a ferroelectric liquid crystal between a pair of substrates on which transparent electrodes are formed and arranging a plurality of color filter units between at least one transparent electrode and the substrate. In the dielectric liquid crystal device, the color filter layer is formed by providing a film of a coloring resin in which a coloring material is dispersed in a polyamide resin having a photosensitive group in the molecule, exposing the film and curing the film, and adjoining the film. When the interval between the matching color filter units is α (μm), 0
A ferroelectric liquid crystal device having a relationship of ≦ α ≦ 5 μm, which is obtained by sequentially laminating a protective layer, a patterned transparent electrode, and an orientation control film on the color filter layer. 4. The ferroelectric liquid crystal device according to claim 3, wherein the polyamide resin is a resin having an aromatic group.