JP2001166316A - Color filter, method of manufacture and liquid crystal element using the color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a spacer to a color filter in high precision and in a high yield. SOLUTION: An ink receptive layer 3 consisting of a photosensitive resin composition is formed on a transparent substrate 1 and patternwise exposed to form parts 6a and 6b to be colored and a part 5 not to be colored. When an ink 8 is applied onto the part 6a to be colored which is to be a colored pixel 9, the ink is also applied onto the part 6b to be colored which is adjacent to the part 6a to be colored through the part 5 not to be colored and the part 6b to be colored is expanded greater than the colored pixel 9 as a color mixture area onto which the two-color ink 8 is applied to be adopted as the spacer 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device for color display used in a color television, a personal computer, a pachinko game machine, and the like, a color filter as a constituent member of the liquid crystal device, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a color filter, a mordant layer made of a hydrophilic polymer such as gelatin, casein, glue or polyvinyl alcohol is provided on a transparent substrate, and then the mordant layer is dyed with a dye. Forming a uniform layer using a color filter (dyeing color filter) by a dyeing method for forming colored pixels of a color filter by using a photosensitive coloring resin in which a coloring agent such as a pigment is dispersed in a transparent resin. There is known a color filter (a pigment method color filter) in which a colored resin layer is patterned by photolithography and a colored layer is patterned by photolithography to form colored pixels.

[0003] However, the above-mentioned dyeing color filters require complicated processes such as mordant treatment of a mordant layer for each color, and therefore have problems in terms of productivity, yield, and the like, and are particularly disadvantageous in terms of production cost. It is. In the case of forming a color filter by a pigment method, an expensive photosensitive colored resin is applied on a substrate by a spin coating method, and the use efficiency of the colored resin is very poor because a colored resin layer is formed. This is also disadvantageous in production cost.

On the other hand, in order to meet the demand for a low-cost color filter from the device side by using a simpler process and to increase the use efficiency of the colored resin, a color filter in which a colored pixel is formed using an ink jet method has been developed. JP-A-59-75205, JP-A-63-23590
No. 1, JP-A-1-217320 and the like. In a liquid crystal display in which a conventional color filter is provided, a metal light-shielding layer pattern (a so-called black matrix) is usually arranged in contact with a glass substrate, and the metal light-shielding layer pattern partially overlaps the light-shielding layer pattern. Is provided with a color filter.

In recent years, a method of providing a pattern having a spacer function in a color filter portion in advance has been performed for the purpose of simplifying a step of dispersing spacers and assembling cells in a liquid crystal display manufacturing process. ing. In this case, generally, a color filter is overlapped with an adjacent color to form a spacer, or a spacer pattern is formed by a photolithography method using a photosensitive resin after forming the color filter.

[0006]

In the above-mentioned conventional method for forming a spacer, the spacer must be formed with high accuracy by using a photolithography method, and the method for forming a color filter lowers productivity and yield. there were. Further, when a new photosensitive resin is used for the spacer, there has been a problem in terms of cost including materials.

An object of the present invention is to provide a color filter in which spacers are accurately formed by simple steps, and to provide a highly reliable liquid crystal element at a lower cost by using the color filter.

[0008]

A method of manufacturing a color filter according to the present invention is a method of manufacturing a color filter having a plurality of colored pixels on a transparent substrate and a spacer between adjacent colored pixels, comprising the steps of: Forming an ink receiving layer made of a resin composition, and applying the ink to the ink receiving layer to form a colored pixel, by applying the ink of different colors to the ink receiving layer so as to be mixed with each other, A spacer is formed between adjacent colored pixels by forming a mixed color region protruding from the colored pixel.

In the present invention, preferably, an ink receiving layer is formed by using a photosensitive resin composition whose ink receiving ability is changed by light irradiation, and the ink receiving layer is formed in a color pixel area and a color mixing area by pattern exposure. Forming a non-colored part having a lower ink receiving capacity than the colored part at the boundary between the colored pixel and the mixed color area; At the same time as applying the ink, the ink is also applied to the colored portion which is a mixed color region beyond the non-colored portion adjacent to the colored portion.

[0010] In the present invention, the means for applying ink to the ink receiving layer is preferably an ink jet method. Further, a light-shielding layer for shielding at least between colored pixels of different colors is provided on a transparent substrate. It is preferable that the light shielding layer is a metal or metal oxide layer having a thickness of 0.1 to 2.0 μm or a black resin layer having a thickness of 0.5 to 2.0 μm.

A color filter according to the present invention is characterized in that a spacer is provided between a plurality of colored pixels and adjacent colored pixels on a transparent substrate, and is manufactured by the above-described method for manufacturing a color filter of the present invention. The present invention includes a color filter having a protective layer on a colored pixel as a preferred embodiment.

Further, the present invention provides a liquid crystal element characterized in that a liquid crystal is sandwiched between a pair of substrates, and one of the substrates is formed using the color filter of the present invention.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the method of manufacturing a color filter according to the present invention, colored pixels are formed by applying ink to an ink receiving layer made of a resin composition. When the ink receiving layer absorbs ink, it swells and expands in volume. At this time, a color mixture region is intentionally provided between adjacent colored pixels of different colors. The degree of expansion of the volume of the ink receiving layer is proportional to the amount of ink absorbed. However, in the mixed color region, since two different colors of ink are absorbed, the ink receiving layer expands more than the colored pixel and forms a convex shape higher than the colored pixel surface. Will be done. In the present invention, this is used as a spacer for maintaining a gap between the display and the counter substrate when forming a display.

In the present invention, the width and length of the mixed color area are
It is preferable to set appropriately in consideration of the prevention of color mixing in the colored pixels, the height required for the spacer, and the height of the ink receiving layer that absorbs ink and swells. In particular, in the present invention, the ink-receiving layer is formed of a photosensitive resin composition, and is subjected to pattern exposure in advance to form a non-colored portion between a color pixel involved in display and a color-mixed region serving as a spacer, thereby performing color mixing. In the mixed color region surrounded by the non-colored portion is effective in forming a colored pixel without color mixture.
When a spacer having a sufficient height can be formed and a color pixel without color mixture can be formed at the same time, it is not particularly necessary to form a non-colored portion.

FIG. 1 shows the steps of one embodiment of the method for manufacturing a color filter of the present invention. The present embodiment is an example in which the non-colored portion is formed and colored. In FIG. 1, 1 is a transparent substrate, 2 is a black matrix, 3 is an ink receiving layer, 4 is a photomask, 5 is a non-colored portion, 6a and 6b are portions to be colored,
7 is an inkjet head, 8 is an ink, 9 is a colored part,
10 is a spacer, 11 is a protective layer. Hereinafter, each step will be described, and FIGS. 1A to 1E show the following step (a).
It is a cross-sectional schematic diagram respectively corresponding to (e).

Step (a) A black matrix 2 is formed on a transparent substrate 1 as required. As the transparent substrate 1, glass is generally used, but plastics or the like may be used as long as they have necessary characteristics such as strength without impairing the transparency of the color filter. The color filter of the present invention is preferably used mainly for a liquid crystal element, but is preferably used for an element requiring a color filter and a spacer in addition to the liquid crystal element.

The black matrix 2 is a light-shielding layer for shielding at least between adjacent colored pixels of different colors, and may be a black stripe. In the present invention, a metal or metal oxide layer having a thickness of 0.1 to 2.0 μm is preferably used as the light-shielding layer. These light-shielding layers are made of metal or metal oxide by a vacuum deposition or plating.
It is obtained by forming a film thereon and performing patterning and etching by photolithography using a normal photoresist. The metals and metal oxides include Cr, Al,
Cu, Mo, Ni, etc., and their metal oxides and alloys are used.

In the present invention, a black resin layer having a thickness of 0.5 to 2.0 μm is preferably used as a light shielding layer. Such a black resin layer can be easily formed by ordinary photolithography using a commercially available black resist or the like.

If the spacer 10 according to the present invention cannot be formed with a sufficient height, the height can be increased by forming the black matrix 2 thick.

Next, an ink receiving layer 3 is formed on the entire surface of the transparent substrate 1. The ink receiving layer 3 according to the present invention is formed of a resin composition having ink receiving ability. When the non-colored portion 5 is formed in advance before coloring as in the present embodiment, the ink receiving ability is changed by light irradiation. Formed of a photosensitive resin composition. That is, it is formed by a light irradiation using UV light or Deep-UV light or a resin composition in which the ink receiving ability is expressed (increased) or disappeared (decreased) by the light irradiation and heat treatment, and is subjected to pattern exposure and color mixing in the next step. A non-colored portion 5 for prevention is formed. The photosensitivity of the resin composition may be either negative type or positive type, specifically, acrylic resin, epoxy resin, silicone resin, hydroxypropylcellulose, hydroxyethylcellulose, methylcellulose, cellulose such as carboxymethylcellulose. A derivative or a modified product thereof, an amide-based resin, a phenol-based resin, a polystyrene-based resin, or the like is used in combination with a photoinitiator (crosslinking agent) as necessary. In addition, natural products such as gelatin, casein, and glue containing a photosensitive agent, polyvinyl alcohol, and the like can also be used.
As photoinitiators, dichromates, bisazide compounds,
A radical initiator, a cationic initiator, an anionic initiator, and the like can be used, and further, these photoinitiators can be used in combination or in combination with another sensitizer. Furthermore, a photoacid generator such as an onium salt can be used as a crosslinking agent. In this embodiment,
Loses (or reduces) ink receptivity by light irradiation,
An example using a negative resin composition will be described.

The above photosensitive resin composition is spin-coated,
It is applied on the transparent substrate 1 by a method such as roll coating, bar coating, spray coating, dip coating and the like, and is prebaked as necessary to form the ink receiving layer 3. The thickness of the ink receiving layer 3 is usually about 0.1 to 5.0 μm, preferably about 0.5 to 2.0 μm.

When it is necessary to improve the adhesion between the ink receiving layer 3 and the transparent substrate 1, if the ink receiving layer 3 is formed after a thin coating of a silane coupling agent or the like on the transparent substrate 1 in advance. Alternatively, the ink receiving layer 3 may be formed using a resin composition to which a small amount of a silane coupling agent is added.

Step (b) The photoreceptor 4 is used to pattern-expose the ink receiving layer 3 to extinguish (or reduce) the ink receptivity of the exposed portions to form the non-colored portions 5. The non-colored portion 5 is formed by opening a mixed color region at a position overlapping the black matrix 2,
In particular, from the viewpoint of preventing white spots at the boundaries of the openings of the black matrix 2, it is preferable to form them inside the black matrix. In order to enhance the effect of preventing color mixing, it is also preferable to apply a component that causes the non-colored portion 5 to exhibit ink repellency to the ink receiving layer 3.

The areas not exposed in this step are the colored portions 6a and 6b. When a positive-type resin composition that develops (or increases) ink receptivity upon exposure is used, exposure may be performed in the reverse pattern.

Step (c) The ink 8 of a predetermined color is applied from the ink jet head 7 along a predetermined coloring pattern on both sides adjacent to the portion 6a to be colored and the portion 6a to be colored via the non-colored portion 6b. It is discharged to the colored portion 6b (mixed color region) and colored. At this time, since the non-colored portion 6b is interposed between the coloring portion 6b and the adjacent coloring portion 6a from which the ink of a different color is ejected, the ink applied to the coloring portion 6b stays in the coloring portion 6b. The color mixture to the colored portions 6a of different colors is prevented.

As the ink jet method used in the present invention, a bubble jet type using an electrothermal converter as an energy generating element, a piezo jet type using a piezoelectric element, or the like can be used. Can be set arbitrarily. In the present invention, other than the inkjet method, any means that can apply ink to an arbitrary region can be used as appropriate.

The ink 8 used for coloring the ink receiving layer 3 in the present invention is preferably used as long as it contains a colorant such as a dye or a pigment and is liquid at the time of ejection.

In this step, the area of the colored portion 6b, which is a mixed color region, is smaller than the colored portion 6a to be a colored pixel, and the colored portion 6b is adjacent to the colored portion 6a via the non-colored portion 6a. Since the ink is applied at the same time as the ink is applied to the portion 6a, two colors of ink are applied, so that a larger amount of ink is absorbed than the colored portion 6a and higher than the colored portion 6a. Swell.

In the present invention, when a sufficient height as a spacer cannot be obtained only by swelling due to color mixture of the ink in the colored portion 6b, other than the method of increasing the height by the light-shielding layer as described above, a convex When a member is formed in the region or a liquid crystal element is formed, a convex member may be provided on the counter substrate side to supplement the height as a spacer.

Step (d) A necessary treatment such as heat treatment or light irradiation is performed to cure the entire ink receiving layer, thereby forming a colored layer including the non-colored portion 5, the colored pixel 9, and the spacer 10.

Further, if necessary, a protective layer 1 may be formed on the colored layer.
1 to obtain the color filter of the present invention. Protective layer 1
Examples of the material 1 include polyamide, polyimide,
Polyurethane, polycarbonate and silicone resin
Or SiN, SiO_Two, Al_TwoO _Three, Ta_TwoO_FiveMineralization
Compounds, spin coating, roll coating, printing, etc.
Is formed by a coating method or a vapor deposition method. Protective layer
The thickness of 11 is preferably about 0.1 to 2.0 μm. I
Even in the case of misalignment, it has transparency as a color filter,
That withstand the subsequent ITO formation process, alignment film formation process, etc.
Can be used.

FIG. 3 schematically shows the color filter of the present invention viewed from above. In the figure, reference numeral 31 denotes an opening of the black matrix. FIG. 3 shows an example of the color filter formed in the step of FIG. 1 described above.
G (green) and B (blue) colored pixels 9 are sequentially arranged in parallel,
The spacers 10 are arranged side by side with the openings 31 of the black matrix. In the present invention, the formation position of the spacer 10 is not limited to the example of FIG. 3, and the spacer 10 ′ may be provided alternately with the opening 31 of the black matrix as shown in FIG.

Next, FIG. 2 is a schematic sectional view of one embodiment of the liquid crystal element of the present invention. The present embodiment is an example in which a TFT type color liquid crystal element is configured using the color filter of the present invention obtained by the process of FIG. In the figure, 12 is a common electrode, 13 and 23 are alignment films, 21 is a counter substrate, 22 is a pixel electrode, and 24 is a liquid crystal, and the same members as those in FIG.

In general, the color liquid crystal element is formed by aligning the substrate 1 on the color filter side with the counter substrate 21,
Is formed by encapsulating. TFTs (not shown) and pixel electrodes 22 are formed in a matrix inside one substrate 321 of the liquid crystal element. Further, inside the substrate 1 on the color filter side, a colored portion 9 of a color filter is formed at a position facing the pixel electrode 22 so that R, G, and B are arranged, and a transparent common electrode 9 is formed thereon. 12 are formed. The black matrix 2 is usually formed on the color filter side, but may be formed on the counter substrate 21 side such as a BM-on-array type liquid crystal element. Furthermore, alignment films 13 and 23 are formed in the plane of both substrates, and the liquid crystal molecules are arranged in a certain direction. These substrates are opposed to each other via a spacer (not shown), are bonded by a sealing material (not shown), and a liquid crystal 24
Is filled.

In the case of the transmission type liquid crystal element, the substrate 21 and the pixel electrode 22 are formed of a transparent material, a polarizing plate is bonded to the outside of each substrate, and a fluorescent lamp and a scattering plate are generally combined. The display is performed by using the backlight and using the liquid crystal compound as an optical shutter for changing the transmittance of the backlight. In the case of the reflection type, the substrate 21 or the pixel electrode 22 is formed of a material having a reflection function, or a reflection layer is provided on the substrate 21, and a polarizing plate is provided outside the transparent substrate 1. Display is performed by reflecting light incident from the filter side.

In the liquid crystal device of the present invention, as long as it is constituted by using the color filter of the present invention, it is needless to say that the conventional technique can be used as it is for the other members.

[0037]

(Example 1) Deep-U was placed on a glass substrate.
An acrylic resin having sensitivity to V light was applied by a spin coating method to a thickness of 1.0 μm, and prebaked in an oven at 50 ° C. for 1 minute. Then
The width between adjacent colored pixels is 30 μm, and a mixed color region having a width of 20 μm and a length of 50 μm between the widths and 5 μm on both sides thereof.
Using a pattern mask capable of forming a non-colored portion having a width, De
Exposure was performed at 60 mJ / cm ² with ep-UV light.

Then, the substrate was left on a hot plate at 110 ° C. for 60 seconds, subjected to PEB (post exposure bake) treatment, and then dye-based R, G, and B inks were ink-jetted. It was applied to the colored portions including the mixed color regions on both sides by the drawing apparatus of the system.
Next, after drying at 90 ° C. for 10 minutes, 230
Perform a post-baking treatment at 30 ° C. for 30 minutes to obtain R, G,
A color filter having a B colored pixel, a spacer formed by color mixture positioned between the colored pixels, and a transparent non-colored portion positioned between the spacer and the colored pixel was obtained.

The obtained color filter was of high quality with no color mixture in the area related to display. On this color filter, a protective layer having a thickness of 1.0 μm was formed using an acrylic thermosetting resin. The spacer of the color filter after the formation of the protective layer had a height difference of 5.0 μm from the color pixel, and was sufficiently usable as a spacer of a liquid crystal element.

The color filter shown in FIG. 2 was formed using the above color filter. First, a common electrode was formed on a protective layer of a color filter by using a metal mask to deposit ITO to a thickness of 130 μm by a sputtering method.
Further, a polyimide alignment film forming solution was applied thereon by an alignment film printer and heated at 200 ° C. for 1 hour to form a 100 μm-thick polyimide film, and the surface was rubbed to form an alignment film.

The color filter-side substrate thus obtained was bonded to a counter substrate on which a TFT, a pixel electrode, and an alignment film were formed, and a cell was assembled. A liquid crystal was injected to produce a liquid crystal element. In the obtained liquid crystal element, the cell gap was maintained by the spacer formed in the color filter. Therefore, although no spacer was used in the cell assembling process, high-quality display without display unevenness was obtained. In addition, since the spacer of the present invention is formed by using color mixture of inks, the liquid crystal element has high light absorption, does not affect display even when obliquely observed, and has high visibility.

[0042]

As described above, according to the present invention,
Since a spacer that does not adversely affect the display can be formed with high precision in the color filter coloring step, a liquid crystal element can be configured in a shorter process using the color filter, and a more reliable high-quality liquid crystal element can be formed. It becomes possible to provide a color liquid crystal element for display at lower cost.

[Brief description of the drawings]

FIG. 1 is a process chart of one embodiment of a method for manufacturing a color filter of the present invention.

FIG. 2 is a schematic sectional view of one embodiment of the liquid crystal element of the present invention.

FIG. 3 is a schematic plan view of an embodiment of the color filter of the present invention.

FIG. 4 is a schematic plan view of another embodiment of the color filter of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Black matrix 3 Ink receiving layer 4 Photomask 5 Non-colored part 6a, 6b Colored part 7 Inkjet head 8 Ink 9 Colored pixel 10 Spacer 11 Protective layer 12 Common electrode 13, 23 Alignment film 21 Counter substrate 22 Pixel electrode 24 LCD

 ──────────────────────────────────────────────────続 き Continued from the front page F term (reference) 2H048 BA02 BA11 BA64 BB01 BB02 BB07 BB08 BB14 BB42 2H089 LA09 LA11 LA16 MA01X MA04X NA02 NA05 NA14 NA24 QA12 QA14 TA09 TA12 TA13 TA15 TA17 TA18 2H091 FA02Y FA35Y FB06 FB06 LA12

Claims (9)

[Claims] 1. A method for manufacturing a color filter comprising a plurality of colored pixels and a spacer between adjacent colored pixels on a transparent substrate, comprising: forming an ink receiving layer made of a resin composition on the transparent substrate; In the step of applying ink to the ink receiving layer to form a colored pixel, by applying inks of different colors to the ink receiving layer so as to be mixed with each other, a mixed color projecting between the adjacent colored pixels more than the colored pixel A method for manufacturing a color filter, comprising forming a region to form a spacer. 2. An ink receiving layer is formed by using a photosensitive resin composition whose ink receiving ability is changed by light irradiation, and a region to be a colored pixel and a mixed color region having the ink receiving capability are exposed by pattern exposure. Forming a non-colored portion having a lower ink receiving capacity than the colored portion at the boundary between the colored pixel and the mixed color region, and applying the ink to the colored portion to be a colored pixel in the coloring step, 2. The method for manufacturing a color filter according to claim 1, wherein the ink is also applied to a colored portion which is a mixed color region beyond a non-colored portion adjacent to the colored portion. 3. The method for producing a color filter according to claim 1, wherein the means for applying ink to the ink receiving layer is an ink jet system. 4. The method for producing a color filter according to claim 1, wherein a light-shielding layer for shielding at least between colored pixels of different colors is formed on the transparent substrate. 5. The method according to claim 4, wherein the light-shielding layer is a metal or metal oxide layer having a thickness of 0.1 to 2.0 μm. 6. The method according to claim 4, wherein the light-shielding layer is a black resin layer having a thickness of 0.5 to 2.0 μm. 7. A color produced by the method for producing a color filter according to any one of claims 1 to 6, further comprising a spacer between the plurality of colored pixels and adjacent colored pixels on a transparent substrate. filter. 8. The color filter according to claim 7, further comprising a protective layer on the colored pixel. 9. A liquid crystal element comprising liquid crystal sandwiched between a pair of substrates, wherein one of the substrates is formed using the color filter according to claim 7.