JPH08227009A - Color filter - Google Patents

Abstract

PURPOSE: To decrease a reflectance for light in all over the wavelength region of visible light, to improve the dimensional accuracy and light-shielding property and to decrease the cost by providing a transparent electrode which covers a colored relief layer and a black relief layer. CONSTITUTION: This color filter 10 consists of a transparent substrate 13 and color relief layers 16 successively formed on the transparent substrate 13 so that the surface of the substrate 13 is not exposed to air. The color relief layers 16 consist of a red pattern 16R, green pattern 16G and blue pattern 16B (color layers), and a black relief layer (black matrix) 15 is formed on the borders where these color relief layers 16 are connected. The black relief layer 15 is thereby formed in a noncontact state with the transparent substrate 13. Further, a protective layer 18 and a transparent electrode 19 are successively formed cover the black relief layer 15 and the color relief layers 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter,
In particular, the present invention relates to a color filter having high display contrast, high dimensional accuracy, and excellent light-shielding properties.

[0002]

2. Description of the Related Art In recent years, monochrome or color liquid crystal displays have been attracting attention as flat displays. For example, a color liquid crystal display has three pixel parts.
The primary colors (R, G, B) are set, and the color switching is performed by controlling the transmission of light of each of the three primary colors by electrical switching of the liquid crystal. The liquid crystal display uses color filters in both the active matrix system and the simple matrix system to control the three primary colors.

This color filter is constructed by forming each colored layer, a protective layer and a transparent electrode layer on a transparent substrate.
And in order to increase the coloring effect and display contrast,
A black pattern (black matrix) having a light-shielding property is formed at the boundary portion of each of the R, G, and B pixels of the colored layer. Further, in an active matrix type liquid crystal display, since a thin film transistor (TFT) is used as a switching element, it is necessary to suppress a light leak current due to external light. Therefore, the black matrix is required to have a high light-shielding property.

Conventionally, as a black matrix, a chrome thin film formed by vapor deposition, sputtering or the like is photo-etched to form a relief, a hydrophilic resin relief is dyed, and a relief is formed using a photosensitive solution in which a black pigment is dispersed. And those formed by electrodeposition of a black electrodeposition paint, those formed by printing, and the like.

[0005]

However, a chrome thin film photo-etched and relief-formed has a high dimensional accuracy because it uses a photo process, but it requires a vacuum film-forming step such as vapor deposition or sputtering, and the manufacturing process. The manufacturing cost is high due to the complicated process. In particular,
This chrome black matrix needs to suppress the light reflectance on the observer side (visible light reflectance on the transparent substrate side of the color filter) in order to enhance the display contrast under strong external light, and malfunction of the thin film transistor. In order to suppress the light leakage current that causes the above, it is necessary to suppress the light reflectance on the liquid crystal cell side (see Japanese Patent Application No. 5-75178, etc.), and therefore the manufacturing cost is further increased. Need to do.

The method using a photosensitive resist in which a black dye or pigment is dispersed has a low manufacturing cost, but the photosensitive resist is black, so that the photoprocess is liable to be insufficient, and a black matrix having good dimensional accuracy is obtained. There is a problem that can not be obtained.

Further, the black matrix formation by the printing method can reduce the manufacturing cost, but there is a problem when high dimensional accuracy is required.

In order to solve such a problem, the present applicant has previously proposed a black matrix substrate for a color filter and a manufacturing method thereof (Japanese Patent Application No. 3-3).
No. 25821).

However, this black matrix also has a higher light reflectance on the observer side as compared with a black matrix using low-reflection chrome in terms of optical characteristics, and lowers the light reflectance in order to obtain a sufficient display contrast. Was required. In addition, regarding the black matrix of low-reflection chrome having excellent display contrast, the main sensitivity wavelength (55
5 nm), the light reflectance is low, but the visible light wavelength has a short wavelength region (around 400 nm) and a long wavelength region (700 nm).
In the vicinity), since the light reflectance is high, there is a drawback that when viewed from the observer side, a reddish purple interference color is observed and pure black cannot be obtained, and it is required to eliminate this interference color. There is.

Therefore, there is a strong demand for the development of a color filter having a black matrix which satisfies the above-mentioned required characteristics and is inexpensive to manufacture.

The present invention has been made in view of the above circumstances, and an object thereof is to be used for a flat display such as a liquid crystal display, an imager such as a CCD, or a color filter such as a color sensor. It is an object of the present invention to provide a color filter having a black matrix that has a low light reflectance throughout the entire region, high dimensional accuracy, excellent light-shielding properties, and low cost.

[0012]

In order to achieve such an object, the color filter of the present invention comprises a transparent substrate, a colored relief layer formed on the transparent substrate, and a colored relief layer on the colored relief layer. And a black relief layer formed in a non-contact state with the transparent substrate, and a transparent electrode provided so as to cover the black relief layer and the colored relief layer.

Further, the colored relief layer is formed by sequentially connecting the transparent substrate so that the surface of the transparent substrate is not exposed, and the black relief layer contains fine particles therein and the colored relief layer. Are formed on the boundary where they are connected.

Here, the fine particles are nickel, cobalt, copper, or an alloy containing one or more of these metals,
At least one selected from a black dye and a black pigment is suitable.

The fine particles have a particle size of 5 to 50 nm.
It is preferable that the particles within the range have a particle size distribution such that they are 80% or more of all the particles, and the projected area density of the particles in terms of 0.06 μm thickness is 50% or more.

The black relief layer preferably has optical characteristics such that the light transmittance is 1% or less in the visible light wavelength range of 400 to 700 nm.

Further, the fine particles are preferably formed by an electroless plating method.

[0018]

The colored relief layer is a resin film having a film thickness of 0.1 to 2 μm and containing a dye, an inorganic pigment or an organic pigment as a coloring agent, and the coloring agent can be selected from among red, green, blue and the like. It may be a characteristic. Further, in the black relief layer (black matrix), fine particles are uniformly dispersed and deposited in the resin relief formed in advance. Further, in the fine particles, 80% of all particles have a particle size in the range of 5 to 50 nm. The particle size distribution is as described above, and the projected area density of the particles is 50% or more.

Therefore, the above black relief layer (black matrix) has a visible light wavelength range of 400 to 700 nm.
In the range of 1% or less, the optical characteristics are such that the light transmittance is 1% or less, and as a result, the light-shielding property is excellent, the reflectance from the observer side is low, and no interference color is observed. A color filter substrate having a matrix is formed. Further, since the colored relief layer and the black relief layer use the resin relief layer, it is easy to form the pattern of the black relief layer (black matrix). For example, if a photosensitive resin or an electron beam resist is used, the dimensional accuracy is high. It also has the advantage.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an example of an active matrix type liquid crystal display (LCD) using a black matrix substrate manufactured according to the present invention, and FIG. 2 is a schematic sectional view of the same. 1 and 2, the LCD 1 has a color filter 10 and a transparent glass substrate 20 which are opposed to each other with a sealing material 30 in between, and a thickness of about 5 to 1 made of twisted nematic (TN) liquid crystal between them.
A liquid crystal layer 40 having a thickness of about 0 μm is formed, and polarizing plates 50, 5 are provided outside the color filter 10 and the transparent glass substrate 20.
1 is provided and configured.

FIG. 3 is an enlarged partial sectional view of the color filter 10. In FIG. 3, the color filter 10 includes a transparent substrate 13 and a colored relief layer 16 formed on the transparent substrate 13 so as to be sequentially connected to each other so that the surface of the transparent substrate 13 is not exposed. The colored relief layer 16 has a red pattern 16R, a green pattern 16G, and a blue pattern 16B.
The colored relief layer 16 is provided, and the black relief layer (black matrix) 15 is formed on the boundary where these colored relief layers 16 are connected. Therefore, the black relief layer 15 is in a state of being formed in a non-contact state with the transparent substrate 13.

Further, as shown in the drawing, a protective layer 18 and a transparent electrode 19 are sequentially formed on these so as to cover the black relief layer 15 and the colored relief layer 16. In addition, in the color filter 10, the transparent electrode 19 has the liquid crystal layer 4
It is arranged so as to be located on the 0 side. The colored relief layer 16 is arranged in a mosaic pattern in the illustrated example, but the colored pattern is not limited to this and may be a triangular array, a stripe array, or the like.

Display electrodes 22 are provided on the transparent glass substrate 20 so as to correspond to the colored patterns 16R, 16G, 16B, and each display electrode 22 has a thin film transistor (TFT) 24. Further, a scanning line (gate electrode busbar) 26a and a data line 26b are arranged between the respective display electrodes 22 so as to correspond to the black relief layer (black matrix) 15.

In the LCD 1 as described above, each of the colored patterns 16R, 16G and 16B constitutes a pixel, and the display electrode corresponding to each pixel is turned on and off in the state where the illumination light is irradiated from the polarizing plate 51 side. The layer 40 operates as a shutter, and light is transmitted through each pixel of the colored patterns 16R, 16G, and 16B to perform color display.

The transparent substrate 13 of the color filter substrate 12 constituting the color filter 10 is a rigid material such as quartz glass, Pyrex glass, synthetic quartz plate, or the like, or a transparent resin film, an optical resin plate, or the like. A flexible material having flexibility can be used.
Among them, especially Corning 7059 glass is a material having a small coefficient of thermal expansion and is excellent in dimensional stability and workability in high temperature heat treatment, and since it is a non-alkali glass containing no alkali component in the glass, It is suitable as a color filter for LCDs using the active matrix method. In addition, in applications such as reflection projection type, a metal reflective film may be formed on one side surface of the transparent substrate,
Further, a metal reflective film may be used for a thin film transistor or an active matrix display electrode on a silicone substrate.
When a substrate having a reflection portion is used, it becomes a black matrix substrate for a reflection type color filter, and is suitable for a reflection projection type, guest host or scattering type display mode.

Here, an example of a method of manufacturing the color filter substrate 12 used in the present invention will be described with reference to FIG.

In FIG. 4, first, on the transparent substrate 13, a dyeing method of a photoresist, a dispersion method of applying a photosensitive resin in which a pigment is dispersed in advance and making it a relief by a photolithography method, a printing method such as an offset method, an electrodeposition method. The colored relief layer 16 is formed according to various known methods such as (see FIG. 4).
(A)). These colored relief layers 16 are usually the red pattern 16R, the green pattern 16G, and the blue pattern 1
6B colored pattern, these are transparent substrate 1
3 is sequentially formed with a film thickness of about 0.1 to 2 μm so that the surface of No. 3 is not exposed.

Next, a photosensitive resist containing a hydrophilic resin is applied so as to cover the colored relief layer 16, and the photosensitive resist having a thickness of 0.2 to 5.0 μm, preferably 0.2 to 2 μm is applied. The layer 3 is formed (FIG. 4B).

Next, the photosensitive resist layer 3 is exposed through the photomask 9 for the black matrix (FIG. 4).
(C)). Then, the exposed photosensitive resist layer 3 is developed to form a resin relief 4 having a pattern for a black matrix (FIG. 4 (D)). Next, this transparent substrate 13 is subjected to heat treatment (80 to 200 ° C., 5 to 30 minutes), then immersed in an aqueous solution of a metal compound serving as a catalyst for electroless plating, washed with water and dried to obtain a catalyst-containing relief (catalyst-containing resin). Pattern) 5 (FIG. 4 (E)). The heat treatment may be performed after the catalyst-containing relief is formed. And
By bringing the catalyst-containing relief 5 on the transparent substrate 13 into contact with an electroless plating solution, metal particles are deposited in the relief to form a black relief layer 15 (FIG. 4 (F)).

Then, the substrate is subjected to a film hardening treatment by heating or coating with a film hardening agent to form a color filter substrate 12 (FIG. 5).

Another example of the method of manufacturing the color filter substrate 12 will be described with reference to FIG. First, in the same manner as in the case of the first manufacturing method example, on the transparent substrate 13, a dyeing method of a photoresist, a dispersion method of applying a photosensitive resin in which a pigment is dispersed in advance and making it a relief by a photolithography method, an offset, etc. The colored relief layer 16 is formed according to various known methods such as a printing method and an electrodeposition method (FIG. 6A).
These colored relief layers 16 usually have a red pattern 1
6R, a green pattern 16G, and a blue pattern 16B are provided, and these are sequentially formed with a film thickness of about 0.1 to 2 μm so that the surface of the transparent substrate 13 is not exposed.

Then, a photosensitive resist containing a hydrophilic resin and an aqueous solution of a metal compound serving as a catalyst for electroless plating is coated on the transparent substrate 13 so as to cover these colored relief layers 16, and a thickness of 0 is obtained. 2 to 5.0 μm, preferably about 0.2 to 2 μm, is formed as the photosensitive resist layer 6 (FIG. 6B). Next, the photosensitive resist layer 6 is exposed through the black matrix photomask 9 (FIG. 6C). Then, the photosensitive resist layer 6 after exposure is developed and dried, and then heat-treated (80 to 200 ° C., 5
~ 30 minutes) to form a catalyst-containing relief 7 having a relief for the black matrix (Fig. 6).
(D)). Next, the catalyst-containing relief 7 on the transparent substrate 13
Is contacted with an electroless plating solution to form a black relief layer 15 (FIG. 6 (E)).

Then, in the same manner as in the case of the first manufacturing method example, the color filter substrate 12 is formed by subjecting the black matrix to a film hardening treatment by heating or applying a film hardening agent (FIG. 5).

A common characteristic of the above-mentioned production examples of the black matrix substrate is that the colored relief layer is formed and the resin relief containing the catalyst core component having the function of initiating the electroless plating reaction is This is the point that a black matrix (light-shielding layer) of a black relief layer in which fine particles are deposited is formed by an electroless plating method.

Therefore, the color filter substrate 12 is
As shown in FIG. 5, a colored relief layer 16 formed in a predetermined relief shape on the substrate 13 and thereon,
A black relief layer (black matrix) 15 containing at least fine metal particles therein, and optionally having a reducible metal salt of an electroless plating solution and a reducing agent and formed into a predetermined relief shape. .

The colored relief layer 16 is a resin film containing a colorant such as a dye, an inorganic pigment or an organic pigment, and the colorant may have any spectral characteristic such as red, green and blue. As the resin used, a resin which can be formed by a printing method or a photolithography method can be applied. As the resin used in the printing method, for example, in the case of intaglio offset printing, various known gravure inks can be used. Examples of the photosensitive resin used in the photolithography method include a polyvinyl alcohol-based photocrosslinking type photosensitive resin and an acrylic resin-based photopolymerization type resin. These resins are used as the black relief layer 1 described below.
The same resin as that used in 5 can be used.

The black relief layer 15 contains at least fine metal particles therein. The fine particles have a particle size of 5 to 5.
Those having a particle size distribution such that particles in the range of 50 nm are 80% or more of all particles, preferably those having a particle size in the range of 10 to 30 nm are 80% or more of all particles, Particularly, it is suitable for lowering the light transmittance while keeping the light reflectance low. When the number of particles having such a particle size distribution and a particle size of more than 50 nm increases, the characteristic distribution (numerical variation) of the light reflectance on the observer side increases, so that there is a region where the light reflectance exceeds 3%. The inconvenience occurs that a good quality black matrix cannot be obtained. Further, if there are many particles having such a particle size distribution and a particle size of less than 5 nm, there is a disadvantage that the light transmittance of 1% or less, which is an optical characteristic required as a black matrix, cannot be obtained. The particle size referred to in the present invention is a value obtained by statistically processing, for example, 100 sample sizes measured from a TEM cross-sectional photograph of a black matrix section.

Further, the fine particles contained in the black relief layer 15 preferably have a projected area density in terms of 0.06 μm thickness of 50% or more, more preferably 70%.
% Or more. If the projected area density of the particles converted to a thickness of 0.06 μm is less than 50%, optical characteristics with a light transmittance of 1% or less cannot be obtained even if the particle size is within the above-specified range.

The light transmittance further relates to the film thickness of the black relief layer (black matrix) 15, and its thickness is set so that the above light transmittance is 1% or less.
The projected area density of the fine particles in terms of a thickness of 0.06 μm is obtained by slicing the black relief layer 15 with a width of 0.06 μm using a microtome in the film thickness direction as shown in FIG. 7 (see FIG. )), This slice piece 15a is obtained by observing the region of the black relief layer 15 with a transmission electron microscope from the slice plane direction (FIG. 7 (b)).

To give an example of a specific measuring method, the thickness of the section was measured with a multi-differential interference microscope or the like, and one having a thickness close to 0.06 μm was selected and used. Note that it is difficult to slice with a thickness of 0.06 μm, and the thickness sliced with a thickness close to that is assumed to be t (nm), and at this time, a measured value of projection density d (%) is obtained. If 0.06
The conversion of the thickness of μm into the projected area density D (%) was calculated by the following formula.

[0042]

[Equation 1] In the production of the black relief layer 15, for example, the plating time, the plating solution temperature,
It may vary depending on factors such as the pH of the plating solution, the agitation of the object to be plated (resin relief containing the catalyst nuclei), the concentration of the activation treatment liquid in the catalyst nucleation step, the treatment time and the like.

In the present invention, the fine particles are at least one selected from nickel, cobalt, copper or alloys of one or more of these metals, black dyes, and black pigments. Examples of black dyes include disazo dyes, metal-containing azo dyes, anthraquinone dyes,
Specific examples include monoazo dyes, hydroxyketone dyes and sulfur dyes, and examples of black pigments include carbon black, graphite, iron black, nickel sulfide, copper sulfide, silver sulfide and lead sulfide. .

The resin used for the black relief layer 15 includes, for example, a photosensitive resist containing a hydrophilic resin, such as natural proteins such as gelatin, casein, glue, ovalbumin, carboxymethyl cellulose, and the like. Polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, maleic anhydride copolymer, and one or more hydrophilic resins such as carboxylic acid modified products or sulfonic acid modified products of the above resins. To a mixture of, for example, a diazo resin having a diazo group having a diazo group and a reaction product of paraformaldehyde, an azide compound having an azide group, a cinnamic acid condensation resin obtained by condensing cinnamic acid with polyvinyl alcohol,
The photosensitivity can be given by adding a resin using a stilbazolium salt or a resin having a photocurable photosensitive group such as ammonium dichromate. In addition,
Of course, the photosensitive group is not limited to the above-mentioned photocurable photosensitive group. As described above, since the photosensitive resist contains the hydrophilic resin, the electroless plating solution is contained in the catalyst-containing relief 5 when the catalyst-containing relief 5 comes into contact with the electroless plating solution as described above. It becomes easy to uniformly permeate, and metal particles can be uniformly deposited and grown in the relief containing the catalyst.

The metal compound serving as a catalyst for electroless plating is
For example, chlorides such as palladium, gold, silver, tin, zinc, platinum, iron and copper, water-soluble salts such as sulfates and nitrates, and complex compounds are used. In particular, in producing the color filter substrate used in the present invention, an activator solution for electroless plating, which is commercially available as an aqueous solution, can be used as it is or after diluting it. When such a metal compound is contained in the photosensitive resist as described above, it is preferably contained in an amount of about 0.01 to 5% by weight in terms of metal ion.

The electroless plating solution is, for example, a reducing agent such as hypophosphorous acid, sodium hypophosphite, sodium borohydride, N-dimethylamineborane, a borazine derivative, hydrazine and formalin, and nickel, cobalt,
Water-soluble reducible heavy metal salts such as iron, copper, chromium, palladium, gold, platinum, tin and zinc, and basic compounds such as sodium hydroxide, potassium hydroxide and ammonia, inorganic acids,
PH adjusters such as organic acids and oxycarboxylic acids such as sodium citrate, ammonium citrate, glycolic acid,
Typical examples are boric acid, carbonic acid, organic acids, and inorganic acid alkali salts. In addition to complexing agents for the purpose of stabilizing heavy metal ions in aqueous solutions, buffer agents, reaction accelerators, stabilizers, surfactants, etc. The electroless plating solution having is used. The electroless plating solution as described above has a pH value of 6 to 6 for controlling the reaction rate.
9. The plating solution temperature is preferably 15 to 50 ° C.

Two or more types of electroless plating solutions may be used in combination. For example, first, an electroless plating solution containing a boron-based reducing agent such as sodium borohydride that easily forms a catalytic nucleus of a plating reaction is used, and then a hypophosphorous acid-based reducing agent with a high metal deposition rate is used. An electrolytic plating solution can also be used.

Among the various reducing agents described above, particularly the boron-based reducing agent is used at room temperature (15 to 30 ° C.) for both the metal compound serving as the catalyst nucleus of electroless plating and the reducible metal salt. It has an excellent ability to be reduced and can be used.

In the present invention, the black relief layer 15 preferably has a light transmittance of 1% or less, more preferably 0.5% or less in the visible light wavelength range of 400 to 700 nm. Further, it is preferable that the light reflectance on the observer side is 3% or less, more preferably 2% or less. Further, regarding the light reflectance on the observer side, it is preferable to have optical characteristics such that the light reflectance at a wavelength of 555 nm is 1% or less, more preferably 0.5% or less. By setting in such a range, in addition to the light-shielding property originally required for the black matrix, the visibility is improved by having a flat reflection spectral characteristic.

The color filter 10 of the present invention is formed by using the color filter substrate 12 as described above.

Further, a protective layer 18 may be provided so as to cover the colored relief layer 16 and the black relief layer 15 (black matrix) of the color filter 10. The protective layer 18 is for the purpose of smoothing the surface of the color filter 10, improving reliability, and preventing contamination of the liquid crystal layer 40. The protective layer 18 includes an acrylic resin, a urethane resin, a polyester resin, an epoxy resin, A transparent resin such as a polyimide resin, particularly a curable resin by heat or light is preferably used. Alternatively, it can be formed using a transparent inorganic compound such as silicon dioxide. The thickness of the protective layer 18 is preferably about 0.5 to 50 μm.

As the transparent common electrode 19, for example, an indium tin oxide (ITO) film can be used. IT
The O film can be formed by a known method such as a vapor deposition method or a sputtering method, and the thickness thereof is preferably about 0.02 to 0.2 μm.

Next, the present invention will be described in more detail with reference to examples. (Preparation of Sample 1 of the Invention) 7059 glass (thickness: 1.1 mm) manufactured by Corning Incorporated was used as a transparent substrate, and a colored relief layer 16 was formed thereon in the following manner.

That is, by using a plate having a stripe-shaped intaglio plate having a plate depth of 6 μm and a width of 110 μm and a silicone blanket, the following ink composition was applied by an intaglio offset printing method so that the surface of the transparent substrate was not exposed at least between the stripe patterns. The products S-1, S-2, and S-3 were printed in this order to form blue, green, and red stripe patterns having a width of 110 μm. Then, the ink composition was thermoset by heating the substrate at 200 ° C. for 30 minutes to form a colored relief layer 16 having a film thickness of 1 to 2 μm. (Composition of varnish) -Polyester acrylate resin (Toagosei Kagaku Kogyo Co., Ltd., Aronix M-7100) 70 parts by weight-Diallyl phthalate prepolymer 30 parts by weight (Composition of ink composition (S-1))-Varnish 100 Parts by weight ・ Pigment (Rionol Blue ES) (Toyo Ink Manufacturing Co., Ltd., CI Pigment Blue 15: 6) 15.5 parts by weight ・ Pigment (Rionogen Violet RL) (Toyo Ink Manufacturing Co., Ltd., CI Pigment Violet 23) 4 parts by weight (composition of ink composition (S-2)) 100 parts by weight of varnish ・ Pigment (Rionol Green 2YS) 22 parts by weight of CI Pigment Green 36 (Toyo Ink Mfg. Co., Ltd.) ・ Pigment (Seika First Yellow) 2700) (CIPigment Yellow 83, manufactured by Dainichiseika Co., Ltd.) 7.5 parts by weight (composition of ink composition (S-3)) 100 parts by weight of varnish Material (Chromophtal Red A3B) (Ciba Pigment Co., CI Pigment Red 177) 32 parts by weight Pigment (Seika Fast Yellow 2700) (Dainichi Seika Chemicals Co., Ltd., CI Pigment Yellow 83) 8 parts by weight Regarding the substrate provided with the colored relief layer 16,
UV ozone treatment is performed, and then a photosensitive resist having the following composition is applied by spin coating.
The photosensitive resist layer (thickness 0.95 μm) was formed by drying at 10 ° C. for 10 minutes. (Composition of photosensitive resist) -Polyvinyl alcohol 5.5% aqueous solution (Nippon Gosei Kagaku KK, Gohsenal T-330) 1000 parts by weight-Diazo resin 5% aqueous solution (Shinko Giken D-011) 71 parts by weight Next, an exposure amount of 150 mJ / cm was applied to the photosensitive resist layer through a photomask (line width 20 μm) for a black matrix using a proximity exposure device manufactured by Dainippon Screen Co., Ltd. ^The entire surface was exposed at ² .
At this time, mask alignment exposure was performed so that a black relief (black matrix) described later was formed on the boundary between the stripe patterns of the colored relief layer. After that, spray development was performed using water at room temperature and air drying was performed to form a resin relief for a black matrix having a line width of 20 μm.

Next, this resin relief is treated at 100 ° C. for 30 minutes.
After heat treatment for 1 minute and allowing it to cool, it was immersed in an aqueous palladium chloride solution having a concentration of 100 ppm (manufactured by Nippon Kanigen Co., Ltd., a 5-fold diluted solution of Red Schumer solution) for 5 minutes, washed with water and drained to obtain a catalyst-containing relief. .

Thereafter, this transparent substrate was placed in an electroless N 40 ° C.
1 for iB plating solution (BEL801 manufactured by Uemura Industry Co., Ltd.)
It was dipped for a minute, washed with water and dried to form a black relief.

After that, this black relief is replaced by 20
Heat treatment was performed at 0 ° C. for 1 hour to form a black relief (black matrix).

Next, a protective layer was formed on the above-mentioned substrate. That is, the formation of the protective layer was performed by applying a coating solution having the composition shown below by a spin coating method (rotation speed 1500 rpm).
m. (The film thickness is 2.0 μm). (Composition of coating liquid for forming protective layer) -Photo-curable acrylate oligomer (o-cresol novolac epoxy acrylate (molecular weight 1500 to 2000)) 35 parts by weight-Cresol novolac type epoxy resin 15 parts by weight-Polyfunctional polymerizable monomer (Dipentaerythritol hexaacrylate (DPHA manufactured by Nippon Kayaku Co., Ltd.)) 50 parts by weight Polymerization initiator (Ciba Geigy, Irgacure) 2 parts by weight Epoxy curing agent (General Electric, UVB1014) ) 2 parts by weight-Ethyl cellosolve acetate 200 parts by weight And an exposure amount of 150 mJ was applied to this coating film by using a proximity exposure device manufactured by Dainippon Screen Co., Ltd.
The whole surface was exposed at / cm ² . Then, the substrate is immersed in 1,1,2,2-tetrachloroethane at room temperature for 1 minute,
Only the uncured portion of the coating film was removed to form a protective film.
Furthermore, an indium tin oxide (ITO) film having a thickness of 0.4 μm was formed on this protective film by a sputtering method to form a transparent electrode, and Sample 1 of the present invention was manufactured. (Preparation of Inventive Sample 2) The electroless NiB plating solution of Inventive Sample 1 was electroless CoB plating solution (manufactured by Uemura Kogyo Co., Ltd., nickel sulfate of metal salt in BEL801 plating solution (concentration: 0.1 mol / l). Example 2 of the present invention was produced in the same manner as Example 1 of the present invention except that cobalt sulfate was changed to cobalt sulfate (concentration: 0.1 mol / l). (Production of Inventive Sample 3) The electroless NiB plating solution of Inventive Sample 1 was electroless CoNiB plating solution (manufactured by Uemura Kogyo Co., Ltd., metal salt component in BEL801 plating solution, nickel sulfate 0.06 mol / l). Sample 3 of the present invention was prepared in the same manner as Sample 1 of the present invention except that the concentration of cobalt sulfate was changed to 0.04 mol / l. (Preparation of Comparative Sample 1) The sample of the present invention except that a gap was provided between the stripe patterns of the colored relief layer and the black relief (black matrix) was directly provided on the transparent substrate in the gap in the sample 1 of the present invention. Comparative Sample 1 was prepared in the same manner as 1. (Preparation of Comparative Sample 2) Comparative Sample 2 was prepared in the same manner as Sample 1 of the present invention except that the plating bath temperature of Sample 1 of the present invention 1 was changed from 40 ° C to 20 ° C. (Preparation of Comparative Sample 3) Comparative Sample 3 was prepared in the same manner as Sample 1 of the present invention except that the plating time of Sample 1 of the present invention was changed from 1 minute to 5 minutes. (Production of Comparative Sample 4) The plating bath temperature of 40 ° C. of the sample 1 of the present invention was changed to 20 ° C., and the plating time was 1
Comparative Sample 4 was prepared in the same manner as Sample 1 of the present invention except that the time was changed from 15 minutes to 15 seconds. (Production of Comparative Sample 5) A chromium oxide film (film thickness 0.025 μm) was formed on the transparent substrate used in the sample 1 of the present invention by a sputtering method, and a chromium film (film thickness 0.11 μm) was further formed thereon. ) Was formed into a film to form a two-layer film substrate. (Chromium film sputtering conditions) -Substrate temperature: 150 ° C-Sputtering power: 2 kW-Ar gas flow rate: 30 sccm-Ar gas pressure: 0.3 Pa-Sputtering rate: 0.05 μm / min Next, on this double-layer film substrate Photosensitive resist (OFPR-800, manufactured by Tokyo Ohka Kogyo Co., Ltd.) by spin coating
10 cP) and then dried at 90 ° C. for 30 minutes to form a photosensitive resist layer (thickness 0.9 μm).

Next, the photosensitive resist layer was exposed through a photomask (line width 20 μm) for a black matrix. As a light source for exposure, an ultrahigh pressure mercury lamp of 2 kW was used and irradiation was performed for 10 seconds. Then, dip development was performed using a developing solution (NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) and air-dried to form a resin relief having a line width of 20 μm for producing a black matrix.

Next, this resin relief is treated at 120 ° C. for 30 minutes.
After heat treatment for 1 minute and allowing to cool, it was immersed in a chromium etching solution (MR-ES, manufactured by The Inktech Co., Ltd.) for 2 minutes to form a metal relief. After that, the resin relief on the metal relief was removed by a remover.

Further, on this substrate, a plate depth of 6 μm and a width of 11
The following ink compositions S-1 and S- were used to prevent the surface of the transparent substrate from being exposed at least between stripe patterns by an intaglio offset printing method using a plate having a 0 μm stripe intaglio and a silicone blanket.
2 and S-3 were printed in this order to form blue, green, and red stripe patterns having a width of 110 μm. Then, the substrate is heated at 200 ° C. for 30 minutes to thermally cure the ink composition to a film thickness of 1
A colored relief substrate having a colored layer of ˜2 μm was obtained.

Next, a protective film was formed on the above-mentioned substrate in the same manner as in Sample 1 of the present invention and indium tin oxide (I
A transparent electrode of a (TO) film was formed to prepare Comparative Sample 5.

The above eight samples (invention sample 1)
.About.3 and Comparative Samples 1 to 5), the particle size and projected area density of the fine particles in the black relief layer (black matrix) were measured by a transmission electron microscope (H-8100, Hitachi, Ltd.), An evaluation was made.

Regarding the light transmittance (T) and light reflectance (R) of the black matrix, a microspectrophotometer (Olympus Optical Co., Ltd., AH2-SRK / ST) was used.
According to (K), the transmitted light and the specularly reflected light of the light which is almost vertically incident on the substrate were measured. In addition, the light transmittance of the black matrix is determined by the above-mentioned device by using a transparent substrate as a reference (100% transmittance) and a background (0% transmittance) when light is completely cut off as a visible light wavelength. The maximum transmittance T (%) measured in the range of 400 to 700 nm was evaluated. Also, the light reflectance is an aluminum vapor deposition plate as a reference,
The measurement was carried out on the basis of the case where there was no reflective object as a background. In particular, the light reflectance was evaluated light reflectance (reflectance of the observer side R _O) in the case of light irradiation from the substrate side of the black matrix 15.

The measurement results are shown in Table 1. Since the measured value of the light transmittance of 0.1% or less is less than the measurement limit value of the device and it is considered that there is no significant difference, the light transmittance T ≦ 0.1
Was written.

[0066]

[Table 1] In addition, "maximum value-minimum value" in the table means a wavelength of 400 to 70.
The difference between the maximum value and the minimum value of the light reflectance in the range of 0 nm. Further, in the case of the sample of the present invention, the transmittance and the reflectance are the boundary between the colored layer R (RED) and the colored layer G (GREEN) in the region where the black matrix is formed (indicated by R / G in Table 1), The boundary between the colored layer G (GREEN) and the colored layer B (BLUE) (indicated by G / B in Table 1), and the colored layer B (BLUE) and the colored layer R (RE
D) is measured at three boundaries (indicated by B / R in Table 1), and in the case of samples other than the sample of the present invention, similar measurement is performed at the boundary between the colored layer R and the colored layer G. went.

As is clear from the results shown in Table 1, the samples 1 to 3 of the present invention have a particle size distribution such that 80% or more of all particles have a particle size of 5 to 50 nm. However, since the projected area density of the particles is 50% or more, the light reflectance on the observer side is remarkably reduced, and the light transmittance (1% or less) required for the light shielding layer of the black matrix is sufficiently obtained. The color filter substrate (black matrix substrate) was extremely excellent.

In particular, the sample 1 of the present invention has a reflectance of 1% at a wavelength of 555 nm on the observer side.
Below, the difference between the minimum value and the maximum value in the wavelength range of 400 to 700 nm was 3% or less, and the transmittance was 0.1% or less. Therefore, no interference color was visually observed.

Further, Samples 1 to 3 of the present invention are samples (Sample 1: Nickel, Sample 2: Cobalt, Sample 3: Nickel-Cobalt alloy) in which the material of the fine particles in the black relief layer is different, and the fine particles are As far as the results of the average particle size and the projected areal density are observed, a significant difference is clearly recognized. Further, when the transmittances are compared, a difference is recognized although the degree is small. However, transmittance 1
%, All samples satisfy the optical characteristics required for a low reflection black matrix, such as a reflectance of 1% or less on the observer side at a wavelength of 555 nm, and in this respect, the influence of the difference in the material of the fine particles is Most likely not. Therefore, within the range of the optical characteristics described above, since the material of the fine particles has almost no effect, the fine particles can be formed by controlling the film structure of the black relief layer such as the particle size and the projected area density. It is presumed that materials other than the metals or alloys shown in (4) will not cause any problem as the low reflection black matrix.

In comparison with the sample of the present invention, the comparative sample 1 (black relief layer) had a transmittance of 1% or less, but the reflectance on the observer side was 4.5% at a wavelength of 555 nm. The difference between the minimum value and the maximum value in the wavelength range of 400 to 700 nm was as large as 5.8%, which was insufficient as a color filter substrate having no interference color and high visibility. Comparing this result with the characteristic result of the sample 1 of the present invention, the colored relief layer between the black relief layer (black matrix) and the transparent substrate has a high visibility because the effect of improving the visibility on the observer side is recognized. It can be seen that it is an essential element that satisfies the required characteristics of the low reflection black matrix.

Further, in Comparative Samples 2 and 4, since the projected area density of fine particles is less than 50%, although the light reflectance is low, the original function of the light transmittance of the black matrix is the light reflectance. However, the value was not sufficient as a black matrix substrate.

In Comparative Sample 3, the projected area density of particles was 89.4%, which is within the definition of the present invention.
Since particles in the particle size range of 5 to 50 nm are less than 80% of all particles, there are many large particles having a particle size of more than 50 nm, and as a result, the light reflectance on the observer side is at the wavelength of 555 nm. Is 7.4%, wavelength 40
The difference between the minimum value and the maximum value of the light reflectance in the range of 0 to 700 nm was 4.5%, which was insufficient for the low reflection black matrix in which no interference color was observed, which is the object of the present invention. .

Further, with respect to Comparative Sample 5, which is a color filter substrate having a current low reflection black matrix composed of a low reflection chromium film, the film structure cannot be compared with the sample of the present invention, but the optical characteristics are compared. The light transmittance is 0.1% or less, and the wavelength is 555.
The observer-side light reflectance in nm is 2.6%, and the observer-side reflectance is in the visible light wavelength range of 400 to 700.
Since the difference between the minimum value and the maximum value of the light reflectance in the range of nm was 8.4%, it was insufficient as a low reflection black matrix in which no interference color was observed.

An LCD panel was manufactured using the color filter of Sample 1 of the present invention thus manufactured and the TFT substrate formed by a known method. In addition, TFT
Amorphous silicon was used for the semiconductor layer of the substrate, and the polarizing plate of the LCD was attached so as to be normally white. In order to evaluate the characteristics of this LCD, the relationship between the gate voltage and the light transmittance of the LCD was measured.

As a result, in the LCD using the color filter according to the present invention, the LCD using the color filter according to the conventional method using chromium as the black matrix layer.
It was found that the gate-off voltage can be reduced by 2 V as compared with

This is because when the conventional color filter is used, a part of the light of the backlight of the LCD is reflected on the surface of the black matrix layer because the black matrix layer of the color filter has a high reflectance. , The incident light to the TFT causes light leakage current of the TFT, whereas the color filter using the color filter substrate of the present invention has a low reflectance on the surface of the black matrix layer. It is presumed that the amount of light irradiation to the TFT is reduced, and as a result, the light leakage current of the TFT is reduced and the gate-off voltage is improved.

From this result, an LCD using a color filter using the black matrix substrate according to the present invention
In, the driving voltage of the LCD can be reduced, and the effect of reducing the power consumption was confirmed. This has a great effect on extending the continuous use time when the dry battery is driven.

Further, in order to evaluate another effect of the color filter according to the present invention, the contrast ratio of LCD was measured. In contrast ratio measurement in a bright place, it was possible to obtain a contrast ratio 2.8 times that of the conventional color filter. It is presumed that this is because the influence of outside light was reduced due to the lower reflectance of the black matrix layer of the color filter. Even when the contrast ratio was measured in a dark place, when the color filter according to the present invention was used, a contrast ratio 1.8 times that of the conventional method could be obtained. This is because when the color filter using the black matrix substrate of the present invention is used, the light leak current of the TFT is reduced as described above.
As a result, it is estimated that the leakage light at the time of black display was improved.

As described above, it was found that the color filter according to the present invention is effective in reducing the power consumption of the LCD and improving the contrast ratio.

[0080]

As described in detail above, according to the present invention,
A colored relief layer is formed on the transparent substrate so that at least the surface of the transparent substrate is not exposed, and at least fine particles are provided inside the colored layers R, G, B corresponding to each pixel of the colored relief layer. A color filter having a structure in which the black matrix of the contained black relief layer is formed, and further including a transparent electrode provided so as to cover the colored relief layer and the black relief layer is obtained.

When this is used for a liquid crystal display device, even a thin film has excellent light-shielding properties, and the reflectance from the observer side is low,
Since no interference color is recognized, the visibility can be improved. Further, in the active matrix method, the light reflectance on the liquid crystal cell side can be suppressed to a low level, so that stray light in the liquid crystal can be reduced and the light leak current that causes the malfunction of the TFT can be suppressed, thereby reducing the power consumption of the LCD. Also, the effect of improving the contrast ratio can be expected.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an active matrix liquid crystal display using a color filter manufactured according to the present invention.

FIG. 2 is a schematic sectional view of the liquid crystal display shown in FIG.

FIG. 3 is an enlarged partial sectional view of a color filter of the present invention used in the liquid crystal display shown in FIG.

FIG. 4 is a process drawing for explaining an example of the method for manufacturing the color filter substrate according to the present invention.

FIG. 5 is a schematic sectional view of a color filter substrate of the present invention.

FIG. 6 is a process chart for explaining another example of the method for manufacturing the color filter substrate according to the present invention.

FIG. 7 is a diagram schematically showing a method for measuring the projected areal density of particles. FIG. 7A is a view in which the peeled black relief layer (black matrix) 15 is sliced in the thickness direction with a width of 0.06 μm, and FIG.
It is a figure which observes the area | region of a black relief layer of the slice piece 15a from a slice surface direction with a transmission electron microscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display (LCD) 2 ... Colored relief resin layer (underlayer) 3 ... Photosensitive resist layer 4 ... Resin relief 5 ... Catalyst containing relief (catalyst containing resin pattern) 9 ... Photomask for black matrix 10 ... Color filter 12 ... Color filter (black matrix) substrate 13 ... Transparent substrate 14 ... Black relief resin layer 15 ... Black relief layer (black matrix) 16 ... Colored relief layer (colored layer) 16R, 16G, 16B ... Colored layer (colored pattern) 18 ... Protective layer 19 ... Transparent electrode

Claims (6)

[Claims] 1. A transparent substrate, a colored relief layer formed on the transparent substrate, a black relief layer formed on the colored relief layer in a non-contact state with the transparent substrate, and these black reliefs. A color filter comprising a transparent electrode provided so as to cover the layer and the colored relief layer. 2. The colored relief layer is sequentially formed so that the surface of the transparent substrate is not exposed, and the black relief layer contains fine particles therein.
The color filter according to claim 1, wherein the colored relief layer is formed on a boundary where the colored relief layers are connected to each other. 3. The fine particles are nickel, cobalt,
The color filter according to claim 2, wherein the color filter is at least one selected from copper, an alloy of one or more of these metals, a black dye, and a black pigment. 4. The fine particles have a particle size distribution such that 80% or more of all particles have a particle size in the range of 5 to 50 nm, and the projected area density of the particles in terms of a thickness of 0.06 μm is 50.
% Or more, The color filter according to any one of claims 2 and 3. 5. The black relief layer has optical characteristics such that the light transmittance is 1% or less in a visible light wavelength range of 400 to 700 nm. The color filter described in Crab. 6. The method according to claim 2, wherein the fine particles are formed by an electroless plating method.
The color filter according to any one of 1.