JPH08194111A - Ink for liquid crystal color filter, production of liquid crystal color filter and liquid crystal color filter - Google Patents

Abstract

PURPOSE: To obtain the ink for a liq. crystal color filter excellent in resistance to heat and solvent and in resolution, satisfying ink jet adaptability and by which a color filter is produced at a low cost by incorporating a specified component. CONSTITUTION: This ink for a liq. crystal color filter is used to produce a liq. crystal color filter formed by arranging a colorant on a substrate by ink jetting, and the ink contains a monomer consisting of a structural unit shown by the formula and/or a copolymer with other vinyl monomers. In the formula, R1 is H or CH3 , and R is H or 1-5C alkyls. The content of monomer and/or copolymer in the ink is preferably controlled to 0.005-30wt.%, or more preferably to 0.1-10wt.%. N-methylolacrylamide, N-methoxymethylacrylamide, N- ethoxymethylacrylamide, N-isopropoxymethylacrylamide, etc., are exemplified as the monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal color filter ink suitable for use in a method of manufacturing a liquid crystal color filter in which a colorant is arranged on a substrate by using an ink jet method, and a liquid crystal color filter using the ink. The present invention relates to a manufacturing method and a liquid crystal color filter manufactured by the method.

[0002]

2. Description of the Related Art The development of personal computers in recent years,
In particular, with the development of portable personal computers, the demand for liquid crystal displays, especially color liquid crystal displays, tends to increase. However, cost reduction is necessary for further spread, and there is an increasing demand for cost reduction of a color filter, which has a particularly high cost weight.

Conventionally, various manufacturing methods have been attempted in order to meet the above-mentioned requirements while satisfying the required characteristics of the color filter, but at present, a method that satisfies all the required performances has not yet been established. .

The conventional manufacturing method will be described below.

The first and most frequently used method is the dyeing method. The dyeing method is to add a photosensitizer to a water-soluble polymer material that is a material for dyeing on a glass substrate to sensitize it.
After patterning this into a desired shape by a photolithography process, the obtained pattern is immersed in a dyeing bath to obtain a colored pattern. Repeat this 3 times for R, G, B
Forming a color filter layer.

The second method, which is often used next, is the pigment dispersion method, which is recently replacing the dyeing method. In this method, first, a photosensitive resin layer in which a pigment is dispersed is formed on a substrate, and this is patterned to obtain a monochromatic pattern. By repeating this process three times,
A color filter layer of three colors of R, G and B is formed.

A third method is an electrodeposition method. In this method, first, a transparent electrode is patterned on a substrate. Then, dip it in an electrodeposition coating solution containing pigment, resin, electrolyte, etc.
Electrodeposit the color of. This process is repeated 3 times and R, G, B
Then, the color filter layer is formed and finally baked.

As a fourth method, a paint in which a pigment is dispersed in a thermosetting resin is used, and three colors R,
Paint G and B separately. Then, there is a printing method in which the resin, which is the colored layer, is heated and cured to form the colored layer. In each method, a protective layer is generally formed on the colored layer.

Common to these methods is R,
The same process is repeated three times to form G and B, which inevitably increases the cost. There is also a problem that the yield decreases as the number of processes increases.

In addition, in the case of the method by the third electrodeposition, the pattern formation is limited, so that the present technology cannot be applied to the TFT color. In the fourth method, problems such as poor resolution and smoothness may occur, and a fine pitch pattern cannot be formed.

[0011]

In order to solve these problems, various methods of manufacturing a color filter using an inkjet method have been proposed. Examples thereof include JP-A-59-75205, JP-A-63-235901, JP-A-1-217302, and JP-A-4-123005, but these cannot be said to have sufficiently solved the problem and are still insufficient. is there.

The object of the present invention is to obtain the heat resistance of the conventional method,
An ink for a liquid crystal color filter used in a manufacturing method that can provide an inexpensive color filter that satisfies necessary properties such as solvent resistance and resolution, and that also satisfies inkjet suitability, and has a shortened process, and the ink The present invention provides a method for producing a color filter using, and a highly reliable color filter produced by the method. In particular, in the method using the ink colored layer, the conventionally used ink colored layer is low in heat resistance and solvent resistance, so that it is subject to process restrictions in the ITO forming step and the alignment film forming step. Therefore, it becomes difficult to manufacture a highly reliable color filter for liquid crystal. From such a point, it is desired that the composition can be directly printed on the substrate, or can be printed on the composition which does not have so high ink-accepting ability and satisfies the process resistance such as heat resistance and solvent resistance. is there.

From this point of view, Japanese Patent Laid-Open No. 5-2240
As described in No. 07, some inks contain a melamine-based compound in the ink, but there is a problem in the ejection property of the inkjet head.

The object of the present invention is to obtain the heat resistance of the conventional method,
An ink for a liquid crystal color filter used in a manufacturing method that can provide an inexpensive color filter that satisfies necessary properties such as solvent resistance and resolution, and that also satisfies inkjet suitability, and has a shortened process, and the ink The present invention provides a method for producing a color filter using, and a highly reliable color filter produced by the method.

[0015]

In order to solve the above problems, the present invention provides a liquid crystal color filter ink used in a method for producing a liquid crystal color filter in which a colorant is arranged on a substrate by using an inkjet method. In addition, the ink is an ink containing at least a monomer consisting of the following structural units alone and / or a copolymer with another vinyl-based monomer:

[0016]

Embedded image However, R ₁ H or CH ₃ R ₂ H or a C _{1 to} C ₅ alkyl group is proposed.

Further, according to the present invention, in the method for producing a color filter for liquid crystal in which a colorant is arranged on a substrate by ejecting ink using an ink jet system, the above-mentioned ink for liquid crystal color filter is used. In a method for producing a filter and a method for arranging a colorant on a substrate by ejecting ink by using an inkjet method, first, the composition is provided directly on the substrate or on the composition by using the inkjet method. After arranging the colorant by ejecting the ink, the method for producing a color filter for liquid crystal is characterized by irradiating light or heating to cure the landed ink.

The ink is an ink curable by heat treatment, the curable ink is an ink curable by light irradiation, and a curable resin composition layer is formed on the cured ink. And that the curable resin composition layer is a resin composition layer curable by light irradiation, and the curable resin composition layer is a resin composition part layer curable by heat treatment. .

The present invention is also a liquid crystal color filter manufactured by the above method.

The present invention will be described in more detail below.

The ink of the present invention is a liquid crystal color filter ink used in a method for manufacturing a liquid crystal color filter in which a colorant is arranged on a substrate by using an inkjet method, and the inks of R, G and B are used by the inkjet method. A colored pattern colored in each color (red, green, black) or the like is formed on the substrate. The ink of the present invention is a curable ink used for coloring, and at least contains a monomer of the structural unit (I) alone and / or a copolymer with another vinyl monomer. Good.

The content of the above-mentioned monomer alone and / or other vinyl copolymer in the ink is preferably 0.005 to 30% by weight, more preferably 0.1 to 10% by weight.

If the amount is more than this range, the ejection performance of the ink jet head may be deteriorated. If the amount is less than this range, the effects of the present invention, that is, the heat resistance and solvent resistance are not sufficient. Not demonstrated.

Examples of the monomer composed of the structural unit represented by (I) above include N-methylol acrylamide, N-methoxymethyl acrylamide, N-ethoxymethyl acrylamide, N-isopropoxymethyl acrylamide and N-methylol methacrylamide. , N-methoxymethylmethacrylamide, N-ethoxymethylmethacrylamide, and the like, but are not limited thereto. These monomers may be copolymerized alone or with other vinyl monomers. Other vinyl monomers include
Acrylic acid, methacrylic acid, methyl acrylate, acrylic acid esters such as ethyl acrylate, methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxymethyl acrylate, hydroxyethyl acrylate and other hydroxyl groups Vinyl monomers containing styrene, α-methylstyrene, acrylamide, methacrylamide, acrylonitrile, allylamine, vinylamine, vinyl acetate, vinyl propionate, etc., but of course not limited to these. .

The content of the compound of formula (I) in the copolymer is 5-95 wt%, preferably 7-90 wt%, more preferably 10-85 wt%. When the content of the compound of the formula (I) is less than 5%, the ink absorbability of the portion where the ink absorbency not irradiated with light is not lowered is originally small, and therefore the coloring material in the ink is sufficiently dyed. Not adhering or adsorbing, and when exuding the color material in the subsequent step, it is not preferable because it may cause trouble or white spots in the pixel.

If the amount of the compound of the formula (I) exceeds 95% by weight, the degree of decrease in ink absorbability of the light-irradiated portion due to light irradiation or light irradiation and heat treatment is small, and color mixing frequently occurs between adjacent pixels, which is not preferable.

Further, when photocuring, various resins may be added with a photoinitiator.

As the coloring material, either a dye type or a pigment type can be used. Furthermore, various commercially available resins and additives may be added as other components, and the components are not particularly limited as long as they do not cause problems such as sticking in the ink. Specifically, acrylic resin, epoxy resin, etc. are preferably used. The ink may be prepared by mixing and dissolving or dispersing each of the above components in water or a known solvent to prepare the ink by a conventional method.

Next, the manufacturing method of the present invention will be described with reference to the drawings.

FIG. 1 shows a method for manufacturing a color filter for liquid crystal according to the present invention, and shows an example of the constitution of the color filter for liquid crystal according to the present invention.

In the present invention, a glass substrate is generally used as the substrate, but the substrate is not limited to the glass substrate as long as it has necessary properties such as transparency and mechanical strength as a liquid crystal color filter.

FIG. 1A shows a diagram in which the black matrix 2 is formed on the glass substrate 1. still,
In the case of the present invention, the resin composition layer 3 is further coated on the black matrix 2 as shown in FIG. 1 (b), and the resin composition layer 3 is coated on the glass substrate 1 as shown in FIG. 1 (c). The black matrix 2 may be formed thereon. According to the present invention, the resin composition layer 3 may be omitted, but it is preferably present in the sense that the spread of the landed ink is adjusted to a desired diameter.

The resin composition layer 3 is not required to have the ink receptivity as an OHP film, but is required to have process resistance such as heat resistance. Such a resin composition layer 3 repels ink and is not so high in water repellency and oil repellency,
Further, any material having excellent process resistance such as heat resistance may be used. That is, acrylic type, epoxy type, imide type and the like are preferably used, but not limited thereto.
Moreover, these resin compositions may be cured after printing using a heat-curable or photocurable resin composition. This resin composition layer 3
Is applied by methods such as spin coating, roll coating, bar coating, spray coating, and dip coating, but is not limited to these. Of course, such a resin composition layer 3 does not have to exist, and as shown in FIG. 1D, the ink is just filled in the black matrix pattern in FIG. The R, G, B patterns may be formed in such a manner. Further, the respective color inks may be printed on the black matrix 2 within a range where they do not overlap each other. Of course, as shown in FIG. 1 (e), a resin composition as an ink receiving layer may be applied and printing may be performed thereon.

The aforementioned liquid crystal color filter ink is preferably used for coloring the R, G and B matrix patterns. As the coloring material, either a dye type or a pigment type can be used. Further, as the ink jet, a valve 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, and a coloring area and a coloring pattern can be arbitrarily set. . In addition, as a black matrix forming method in this example, when directly provided on a substrate, a metal thin film is formed by sputtering or vapor deposition, and patterning is performed by a photolithography process.
Moreover, when providing on a resin composition, patterning by a general photolithography process may be mentioned, but the patterning is not limited thereto. Next, as shown in FIG. 1F, light irradiation, heat treatment, or both light irradiation and heat treatment are performed to cure the printed portion. At this time, if the resin composition as the ink receiving layer is of a curable type, it can be simultaneously cured. Subsequently, as shown in FIG. 1G, a protective film is formed if necessary. Protective layer 5
As the material, a resin material that can be cured by light irradiation or heat treatment, or both of them, or an inorganic film formed by vapor deposition or sputtering can be used, and it has transparency when used as a color filter, and ITO after that is used.
Any material can be used as long as it can withstand the formation process, the alignment film formation process, and the like.

[0035]

The present invention will be described below in detail with reference to examples. (Example 1) A self-crosslinking thermosetting resin composition (trade name Cymac 450 manufactured by Toagosei Kagaku Co., Ltd.) composed of an acrylic-silicon graft polymer was formed on a glass substrate on which a black matrix was formed so as to have a film thickness of 2 microns. Spin coated and air dried. Next, the matrix pattern of R, G, B was colored with an inkjet printer.
The ink used was an R, G, B dye, a water-soluble organic solvent, water, and a binary copolymer of N-methylolacrylamide and methyl methacrylate (copolymerization ratio 50:50). When this ink was used, the ink jetting property was good. After coloring with this ink, the printed part and the resin composition were cured by heat treatment at 200 ° C. for 1 hour. Further, a two-component thermosetting resin material (trade name: OPTOMER SS6688 manufactured by Japan Synthetic Rubber Co., Ltd.) is spin-coated thereon to a film thickness of 1 micron and heat-treated at 230 ° C. for 30 minutes to cure it. Thus, a liquid crystal color filter was prepared. When the color filter for liquid crystal thus produced was observed with an optical microscope, problems such as color mixing and color unevenness were not observed.

The composition of the ink used is shown in the table below.

[0037]

[Table 1] Dye 5 g Organic solvent (N-methylpyrrolidone) 20 g Water 73 g Copolymer 2 g The R dye is C.I. I. Directred240, G
The dye is C.I. I. AcidGreen12, B dye is C.I.
I. DirectBlue273 was used. (Example 2) In Example 1, as ink, R,
G, B dye, water, a water-soluble organic solvent, and a terpolymer of N-methylolacrylamide, methyl methacrylate and hydroxyethyl methacrylate (copolymerization ratio 30:
20:50) was used. When this ink was used, the ink jetting property was good.
Then, after printing, a color filter was prepared in exactly the same manner as in Example 1 except that the printed portion and the resin composition were cured by heat treatment at 200 ° C. for 30 minutes. When the color filter for liquid crystal thus produced was observed with an optical microscope, problems such as color mixing and color unevenness were not observed.

The compositions of the R, G and B inks are shown in the table below.

[0039]

Table 2 Dye 4 g Copolymer 4 g Water 85 g Organic solvent (isopropyl alcohol) 7 g The same R dye, G dye and B dye as in Example 1 were used. (Example 3) A color filter was prepared in the same manner as in Example 2 except that the ink of Example 2 was used and the resin composition as the ink receiving layer was not applied, and the ink was directly printed on the glass substrate. . When the color filter for liquid crystal thus produced was observed with an optical microscope, problems such as color mixing and color unevenness were not observed. (Example 4) A photocurable resin composition comprising polyvinylpyrrolidone and a bisazide compound on a glass substrate on which a black matrix was formed (Tokyo Ohka Kogyo NONCRO
N) is spin coated to a film thickness of 2 microns,
Probaking was performed at 0 ° C. for 20 minutes to form a photocurable resin composition layer. Next, the matrix pattern of R, G, B was colored with an inkjet printer. As the ink, R, G, B dyes, a water-soluble organic solvent and water, a terpolymer of N-methylol acrylamide, styrene and hydroxyethyl acrylate (copolymerization ratio 30:40:40), and photoinitiation As an agent
A material consisting of triphenylsulfonium trifluoromethyl sulfonate was used. When using this ink,
The ink jetting property was good. And
After coloring with this ink, UV irradiation (deepUV10
0 mJ / cm ₂ ) whole surface exposure and 200 degrees,
The printed portion and the resin composition were cured by heat treatment for 1 hour. Furthermore, a two-component thermosetting resin material was spin-coated thereon to a film thickness of 1 micron, and the temperature was set to 230 ° C, 3
A color filter for liquid crystal was prepared by performing a heat treatment for 0 minutes and curing. When the color filter for liquid crystal thus produced was observed with an optical microscope, problems such as color mixing and color unevenness were not observed.

The compositions of R, G and B inks are shown in the table below.

[0041]

[Table 3] Dye 6 g Copolymer 2 g Water 77 g Organic solvent (isopropyl alcohol) 5 g Organic solvent (ethylene glycol) 10 g The same R dye, G dye and B dye as in Example 1 are used. I was there. (Example 5) In Example 4, R, G, B in the ink
A color filter was prepared in exactly the same manner as in Example 4 except that the dyes were changed to R, G and B pigments. When this ink was used, the ink jetting property was good. When the color filter for liquid crystal thus produced was observed with an optical microscope, problems such as color mixing and color unevenness were not observed. (Example 6) A color filter was prepared in the same manner as in Example 4 except that the ink of Example 4 was not applied to the resin composition as the ink receiving layer and the ink was directly printed on the glass substrate. . When the color filter for liquid crystal thus produced was observed with an optical microscope, problems such as color mixing and color unevenness were not observed.

As described above, no color mixture or color unevenness was observed in the color filters prepared in Examples 1 to 6, and a series of operations such as ITO formation, alignment film formation and liquid crystal material encapsulation were performed.
A color liquid crystal driving device was created. When the color liquid crystal driving device thus produced was continuously driven for 1000 hours in a temperature range of −20 ° C. to 60 ° C.,
No failure occurred. Further, when it was installed on an OHP and projection drive was continuously performed for 10,000 hours, changes in transmittance and color tone were not confirmed. (Comparative Example 1) A color filter was prepared in the same manner as in Example 1, except that the ink containing no binary copolymer of N-methylolacrylamide and methyl methacrylate was used as the ink in Example 1. (Comparative Example 2) In Example 4, the terpolymer of N-methylolacrylamide, styrene and hydroxyethyl acrylate was used as the ink, and the ink containing no triphenylsulfonium trifluoromethyl sulfonate as the photoinitiator was used. A color filter was prepared in exactly the same manner as in Example 4.

As described above, color mixing, color unevenness, etc. were not observed in the color filters prepared in Comparative Examples 1 and 2, and a series of operations such as ITO formation, alignment film formation, and liquid crystal material encapsulation were performed.
A color liquid crystal driving device was created. When the color liquid crystal driving device thus produced was continuously driven for 1000 hours in a temperature range of −20 ° C. to 60 ° C.,
A failure occurred at a high temperature of 50 degrees or more. Furthermore, OHP
When it was installed on the above and the projection drive was continuously performed for 10,000 hours, a decrease in transmittance and a change in color tone were confirmed. (Comparative Example 3) In Example 1, an ink containing a melamine resin (Sumitex Resin M-3 manufactured by Sumitomo Chemical Co., Ltd.) was used as the ink in place of the binary copolymer of N-methylolacrylamide and methyl methacrylate, and the others were not used at all. Example 1
A color filter was created in the same manner as in.

In Comparative Example 3, the ink ejection property was very poor and the ink dot diameter was unstable, so a large amount of color mixing and white spots occurred.

[0045]

As described above, by producing a color filter for liquid crystal using the ink for liquid crystal color filter of the present invention, a color filter for liquid crystal having no color mixture and color unevenness can be obtained, and heat resistance and solvent resistance can be obtained. It is possible to provide an inexpensive and highly reliable color filter for liquid crystal, which satisfies the required characteristics such as resolution and the inkjet suitability.

[Brief description of drawings]

FIG. 1 (a), (b), (c), (d), (e), (f),
(G) is a process drawing showing an example of a method for manufacturing a color filter of the present invention.

[Explanation of symbols]

 1 substrate 2 black matrix 3 resin composition layer 4 ink 5 protective layer

Claims (9)

[Claims] 1. An ink for a liquid crystal color filter used in a method for producing a color filter for a liquid crystal in which a colorant is arranged on a substrate by using an inkjet method, wherein the ink is a monomer composed of the following structural units. An ink for a liquid crystal color filter, which is an ink containing at least the above homopolymer and / or a copolymer with another vinyl monomer. Embedded image However, R ₁ H or CH ₃ R ₂ H or a C _{1 to} C ₅ alkyl group 2. A method for producing a color filter for liquid crystal in which a colorant is arranged on a substrate by ejecting ink using an inkjet method, wherein the ink for liquid crystal color filter according to claim 1 is used as the ink. And a method for manufacturing a color filter for liquid crystal. 3. A method for manufacturing a color filter for liquid crystal in which a colorant is arranged on a substrate by ejecting ink using an inkjet method, first, directly on the substrate or on a composition provided on the substrate, A method for producing a color filter for liquid crystal, comprising: arranging a colorant by ejecting the ink according to claim 1 using an inkjet method, and then irradiating light or heating to cure the landed ink. 4. The method for manufacturing a color filter for liquid crystal according to claim 2, wherein the ink is an ink curable by heat treatment. 5. The method for producing a color filter for liquid crystal according to claim 2, wherein the curable ink is an ink curable by light irradiation. 6. The method for producing a color filter for liquid crystal according to claim 2, wherein a curable resin composition layer is formed on the cured ink. 7. The method for producing a color filter for liquid crystal according to claim 6, wherein the curable resin composition layer is a resin composition layer curable by light irradiation. 8. The method for producing a color filter for liquid crystal according to claim 6, wherein the curable resin composition layer is a resin composition layer curable by heat treatment. 9. A color filter for liquid crystal manufactured by the method according to claim 2.