JPH024201A - Heat resistant colored paste for color filter - Google Patents

Abstract

PURPOSE:To improve heat resistance, transparency, pattern processability, and solvent resistance and to widen process latitude by polymerizing a polyimide precursor from >=1 kinds of diamine compds. selected from a specific group and incorporating 3,3'-(or 4,4'-)diaminodiphenyl sulfone therein at such a ratio as to occupy the specific concn. in the total diamine component. CONSTITUTION:The polyimide precursor is polymerized from 3,3',4,4'-biphenyl tetracarboxylic diahydride and >=1 kinds of the diamine compds. selected from the group consisting of the 3,3'-(or 4,4'-)diaminodiphenyl sulfone and 1,3-bis(3- aminophenoxy)benzene, 3,3'-diaminodiphenyl methane, etc.; in addition, the 3,3'-(or 4,4'-)diaminodiphenyl sulfone occupies 20-80mol% of the total diamine component. The filter which is free from cracking and has the particularly high transparency with the blue filter is produced in this way and since the solvent resistance is greatly improved, the process latitude in the production process is widened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat-resistant coloring paste for color filters used in liquid crystal displays, I2@ elements, and the like.

[Prior Art] Conventionally, as heat-resistant coloring pastes for color filters, 3, 3",
4.4-biphenyltetracarboxylic dianhydride and 3.
It has been proposed that a highly heat-resistant organic pigment is dispersed in a polyimide precursor varnish polymerized from 3"-(or 4.4'-)diaminodiphenylsulfone (Japanese Unexamined Patent Application Publication No. 6-113)
0-184202, JP-A-60-184203).

[Problem to be solved by the invention] 3.3=, 4°4'- used in the prior art
A polyimide precursor polymerized from biphenyltetracarboxylic dianhydride and 3゜3'-(or 4.4-1)diaminodiphenylsulfone has excellent heat resistance, transparency, and pattern processability, but has poor solvent resistance. Therefore, when manufacturing color filters using heat-resistant colored paste using this polyimide precursor, the manufacturing conditions such as color filter film thickness, photoresist coating solvent, pattern processing conditions, resist stripping agent, etc. are limited. However, the process tolerance is very narrow, and if this condition is even slightly exceeded, the color filter layer will crack and become cloudy, resulting in a significant decrease in transparency.

An object of the present invention is to eliminate the above-mentioned drawbacks and provide a heat-resistant colored paste that has excellent heat resistance, transparency, pattern workability, and solvent resistance, and has a wide process tolerance.

[Means for Solving the Problems] An object of the present invention is to provide a heat-resistant coloring paste for color filters comprising a polyimide precursor, a solvent, and a pigment, wherein the polyimide precursor is 3.3.4.4-biphenyl. Tetracarboxylic dianhydride and 3.3-- (or 4.
4--) diaminodiphenylsulfone and 1,3-bis(3-aminophenoxy)benzene, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, metaphenylene diamine, 3,3' diaminodiphenyl ether, Polymerized with one or more diamine compounds selected from the group consisting of 4,4-diaminodiphenyl ether, and the 3.3"-(or 4.4-)diaminodiphenyl sulfone is a total diamine This is achieved by a heat-resistant coloring paste for color filters characterized by a content of 20 mol % to 80 mol % in the components.

The polyimide precursor in the present invention refers to 3, 3.4.4
”-Biphenyltetracarboxylic dianhydride (hereinafter referred to as BPD)
A), 3.3-- (or 4.4"-) diaminodiphenylsulfone (hereinafter abbreviated as DDS) and 1,
3-bis(3-aminophenoxy)benzene, 3,3'
- One or more diamine compounds selected from the group consisting of diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, metaphenylenediamine, 3,3'-diaminodiphenyl ether, and 4,4-diaminodiphenyl ether (hereinafter referred to as the third component). It is polymerized from Here, the polyimide precursor is one that can be turned into a polyimide having an imide ring by heating or a suitable catalyst.

3,3--(or 4.4') which is an essential diamine component
-) The content of DDS is 20 mol% to 80 mol%, more preferably 30 mol% to 70 mol%, based on the total diamine components contained in the polyimide precursor.

3.3"-(or 4.4"->DDS content is 2
3.3-- (or 4.4"-) if it is less than 0 mol%
) It is not preferable because the transparency and pattern processability caused by the DDS component are extremely reduced, and if it exceeds 80 mol %, the solvent resistance will not be improved.

Furthermore, in order to improve adhesiveness, the polyimide precursor may be copolymerized with an aliphatic diamine having a siloxane structure within a range that does not reduce the heat resistance of the polyimide. Preferred specific examples include bis(3-aminopropyl)tetramethyldisiloxane. The aliphatic diamine copolymer m is preferably 1 to 5 mol % of the total diamine component from the viewpoint of heat resistance.

The diamine component introduced as the third component is
It may have a nuclear substituent such as an amino group, an amide group, a carboxyl group, a sulfonamide group, and a methyl group within a range that does not adversely affect the heat resistance of the polyimide.

When two or more kinds of third components are used, the blending ratio of each component is not particularly limited and can be arbitrarily selected within a range that satisfies the above-mentioned blending conditions.

Particularly preferable combinations of polyimide precursors in the present invention include BPDA and 3.3-- (or 4.4-->DDS,
3-bis(3-aminophenoxy)benzene and bis(3-aminopropyl)tetramethyldisiloxane, BPDA and 3.3--(or 4.4--)DDS and 3
．． 3--(or 4.4--)diaminodiphenylmethane and bis(3-aminopropyl)tetramethyldisiloxane, BPDA and 3.3'-(or 4.4--)DDS and 3
．． Examples include, but are not limited to, 3-- (or 4.4--) diaminodiphenyl ether and bis(3-aminopropyl)tetramethyldisiloxane.

The solvent used in the present invention is preferably a polar solvent from the viewpoint of solubility of the polyimide precursor.

As specific examples, dimethyl sulfoxide, dimethylformamide, N-methyl-2-pyrrolidone, dimethylacetamide, hexamethylphosphoramide, and the like are preferably used.

Further, in order to improve the dispersibility of the pigment and the coating properties of the heat-resistant coloring paste, a part of the polar solvent may be replaced with a solvent such as a hydrocarbon, ester, or higher alcohol.

As the pigment used in the present invention, an organic pigment is used, and one having high transparency and excellent light resistance, heat resistance, and chemical resistance is preferably used. The amount of pigment added to the polyimide precursor is 10 g to 300 g, preferably 20 g to 150 g, per 1 ooq of the polyimide precursor.
It is g. If the amount of pigment added is less than 10g, sufficient performance will not be obtained in the commonly used color filter film thickness of 0.5μm to 5.0μm, and if it is added in excess of 300C1, it will be difficult to uniformly disperse the pigment, and the film forming ability will be reduced. be damaged.

Typical examples of organic pigments that can be used in the present invention are shown by color index (C, 1,) numbers. Yellow pigments include C, 1, Pigmen 1 to Yellow 24, C,
1, Pigment Yellow 83, C, 1, Pigment Yellow 93, C, 1, Pigment 1 to Yellow 94, C, 1
, Pigment Yellow 147° orange pigment, C,
1, Pigment Orange 13, C,1, Pigment Orange 36, C0■, Pigment Orange 43, C,1,
Pigment Orange 61, C, R, Pigment Orange 64, C, 1, Pigment Orange 65° red pigments,
C,1, Pigment Red 48, C,1, Pigment Red 144, C,1, Pigment Red 166, C,1
, Pigment Red 177, C,! , Pigment Red 216, C0■, Pigment Red 224° Purple pigment: C,1, Pigment Violet 19, C
,1, Pigment Violet 23, C01, Pigment Violet 32, C,1, Pigment Violet 37゜Blue-faced, C, T, Pigment 1 to Blue 15, C,1
, Pigment Blue 15:3, C,1, Pigment Blue 15=4, C,1, Pigment Blue 15:3, C,
Examples of 1, Pigment Blue 60° green pigment include C,1, Pigment Green 7, C,1, Pigment Green 36° and black pigment such as C,1, Pigment Black 7.

In addition to the above components consisting of the polyimide precursor, solvent, and pigment, small amounts of surfactants, adhesion improvers, etc. may be added as necessary to the extent that the performance as a color filter and heat resistance are not significantly impaired. good. Examples of surfactants include “
Specific examples include "Florado" FC-430 (manufactured by 3M Company), and the adhesion improver 5H-430 (manufactured by Toshi Silicone Co., Ltd.).

Next, a method for manufacturing the heat-resistant paste for color filters of the present invention will be explained.

The entire amount of the diamine component is added and dissolved into a solvent (for example, dimethylacetamide) heated to about 50° C. while stirring. Next, BPDA is added and polymerized to synthesize a polyamic acid having a predetermined composition.

Next, an organic pigment is added to the obtained polyamic acid, and the pigment is dispersed using a three-roll mill, a sand grinder, or the like to obtain a desired heat-resistant coloring paste for color filters.

In addition, heat resistance in the colored paste for color filters of the present invention means that heat treatment at 300° C. for 20 minutes or more is possible.

[Effect] As explained above, <BPDA and 3.3-- (or 4.
4'->Colored pastes made from polyimide precursor varnishes containing DDS as the main component have excellent heat resistance, transparency, and pattern processability, but they have poor solvent resistance and are difficult to assemble in actual manufacturing processes. Tolerance was very narrow. On the other hand, according to the present invention, 3,
By replacing a specific amount of 3- (or 4.4=-) DDS with a specific diamine component that has excellent solvent resistance and transparency, heat resistance, transparency, pattern processability, and solvent resistance are balanced. It became possible to create a polyimide precursor with good properties.

[Effects of the Invention] By using the heat-resistant colored paste of the present invention, it has become possible to produce filters that do not generate cracks and have high transparency, especially blue filters. In addition, because the solvent resistance has been greatly improved, the process tolerance in the manufacturing process has become wider, and production efficiency has been significantly improved.

[Examples] Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

Example 1 N-Methyl-2-pyrrolidone (hereinafter abbreviated as NMP) solvent 1286.5C1 was weighed into a 30-meter three-meter flask, and 3.3--DDS 119.20 and 1,3-bis(3- Add aminophenoxy)benzene (hereinafter abbreviated as APB) 140.3C1 at 50°C while stirring the solvent,
Completely dissolved.

Next, BPDA 282. OQ was added little by little to react. BPDA (100 mol%), 3.3-DDS (50 mol%) and APB were reacted at 50°C for 5 hours.
A polyamic acid varnish consisting of (50 mol%) was obtained.

The viscosity at this time was measured using an E-type viscometer manufactured by Tokyo Keiki Co., Ltd., and found to be 206 poise/25°C.

Weigh 100g of this varnish into a 250CG beaker,
Phthalocyanine Blue (C, 1, Pigment Blue 15
:4) 10.5g of powder and dioquinazine violet (C
, 1, Pigment Violet 23) 4.5 g of powder was added and kneaded well with a triple roll. NMP 185G was further added to this colored varnish and stirred thoroughly to form a colored paste.

Example 2 NMP, 151,5CJ and 3.3--DD3119.
2CI and 4,4'-diaminodiphenylmethane (hereinafter 4
．． 4--Abbreviated as DAM>95.2g and BPDA 28
From 2.5 g, BPDA (10
0 mol%) and 3,3'DDS (50 mol%) and 4
．． A varnish consisting of 4--CAM (50 mol%) was obtained.

The viscosity at this time was 181 poise/25°C.

Weigh 100g of this varnish into a 250cc beaker,
Phthalocyanine Blue (C, 1, Pigment Blue 15
:4) 8.75g of powder and dioxazine violet (C
, 1, Pigment Violet 23) Powder 3.751 was added and kneaded well with a triple roll. NMP140q was roughly added to this colored varnish and stirred thoroughly to form a colored paste.

Example 3 NMP 1552.4g and 3.3--DDS 149.
0g and 4.4'-diaminodiphenyl ether (hereinafter 4
．． 4--DAE>80.10 and BPDA 28
From 8.34 g, BPDA (1
00 mol%), 3,3''-DDS (60 mol%) and 4.4-DA1 = (40 mol%).The viscosity at this time was 280 poise/25°C. .

Weigh this varnish 100Q into a 250cc beaker,
Phthalocyanine Blue (C, 1, Pigment Blue 15
:4) 8.75g of powder and dioxazine violet (C
, 1, Pigment Violet 23) 3.75 g of powder was added and kneaded well with a triple roll. NMP140Q was further added to this colored varnish and stirred thoroughly to form a colored paste.

Comparative Example NMP 1266g and 3.3--DDS 248.
31g and BPDA 288.34Q in the same manner as in Example 1, BPDA (100 mol%) and 3.3--D
A varnish consisting of DS (100 mol%) was obtained. The viscosity at this time was 188 poise/25°C.

Weigh out 100 CI of this varnish in a 2500 C beaker, and add phthalocyanine blue (C, 1, pigment blue 1).
5:4) 10.5q of powder and dioxazine violet (
4.5 g of C.1, Pigment Violet 23) powder was added and kneaded well with a triple roll. NMP 185'CI was further added to this colored varnish and stirred thoroughly to form a colored paste.

The following evaluation tests were conducted using the colored pastes obtained in Examples 1 to 3 and Comparative Examples.

(Transmittance measurement) The created colored paste is 50m x 50m, thickness, 1mm.
The barcode was placed on a Pyrex glass plate and heated at 150'C for 30 minutes and at 300''C for 30 minutes, resulting in a film thickness of 0 μm.
A colored film of ±0.2 μm was prepared and its spectral characteristics were measured using a spectrophotometer.

The results are shown in Table 1.

(Solvent resistance test) A sample was created in the same manner as above. However, the film thickness was 2.0 μm+0.2 μm. Each sample was incubated in NMP and acetone, respectively, for 60 min and 5% NaOH at room temperature.
After being immersed in the liquid for 10 minutes, the surface was observed using an optical microscope. The results are shown in Table 1.

(Heat resistance test) Using Lean Blue, which was used to measure transmittance, a test was performed at 250°C for 2 hours in air and nitrogen, and when the spectral transmittance was examined, the rate of change was within 5% in both cases. there were.

(Pattern workability) Pattern processing was performed using a positive photoresist according to a conventional method, and microscopic observation was performed. In the case of Example 2, which satisfies the present invention, the edges of all samples were sharply processed. was.

However, in all of the comparative examples, cranking occurred during the positive photoresist stripping process.

As is clear from Table 1, the colored paste of the present invention has excellent solvent resistance while maintaining good transmittance, heat resistance, and workability compared to the colored paste of the comparative example.

Claims (1)

[Claims] 1. A heat-resistant coloring paste for color filters comprising a polyimide precursor, a solvent, and a pigment, in which the polyimide precursor contains 3,3',4,4'-biphenyltetracarboxylic dianhydride and 3,3'-(or 4,4'-)diaminodiphenylsulfone and 1,3-bis(3-aminophenoxy)benzene, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, metaphenylenediamine, 3,3'-diaminodiphenyl ether , 4,4'-diaminodiphenyl ether, and 3,3'-(or 4,4'-)
Diaminodiphenylsulfone accounts for 20% of the total diamine components.
A heat-resistant coloring paste for color filters, characterized in that the content is from mol % to 80 mol %.