RESIN COMPOSITION, CURED PRODUCT, BLACK MATRIX, COLOR FILTER, LIQUID CRYSTAL DISPLAY DEVICE, ORGANIC ELECTROLUMINESCENT DISPLAY DEVICE, AND METHOD FOR PRODUCING RESIN COMPOSITION

Abstract

The present invention provides a resin composition having a high optical density and capable of providing a high-quality color filter excellent in long-term stability and insulation properties. The present invention also provides a cured product of the resin composition, a black matrix, a color filter, a liquid crystal display device, an organic electroluminescent display device, and a method for producing the resin composition. Provided is a resin composition including: amorphous carbon-containing black particles; and a curable compound, the black particles having a specific gravity of 1.75 or lower and an oil absorption as set forth in JIS K 51C1-13-1 of 30 ml/100 g or higher and 120 ml/100 g or lower.

Claims

1. A resin composition comprising: amorphous carbon-containing black particles; and a curable compound, the black particles having a specific gravity of 1.75 or lower and an oil absorption as set forth in JIS K 5101-13-1 of 30 ml/100 g or higher and 120 ml/100 g or lower.

2. The resin composition according to claim 1, wherein the black particles have a powder resistance at a load of 16 kN of 5.0×10.sup.−1 Ω.Math.cm or higher.

3. The resin composition according to claim 1, having an optical density per 1 μm in thickness of 0.6 or higher.

4. The resin composition according to claim 1, wherein the black particles have an average particle size of 5 nm or larger and 300 nm or smaller.

5. The resin composition according to claim 1, wherein the amorphous carbon is derived from carbon contained in an oxazine resin.

6. The resin composition according to claim 5, wherein the oxazine resin is a naphthoxazine resin.

7. A cured product obtained by curing the resin composition according to claim 1.

8. A black matrix formed from the resin composition according to claim 1.

9. A color filter comprising: a substrate; and the black matrix according to claim 8.

10. A liquid crystal display device comprising the color filter according to claim 9.

11. An organic electroluminescent display device comprising the color filter according to claim 9.

12. A method for producing the resin composition according to claim 1, the method comprising: preparing a mixed solution containing formaldehyde, an aliphatic amine, and dihydroxynaphthalene or a mixed solution containing triazine and dihydroxynaphthalene; reacting the mixed solution to form oxazine resin particles; and carbonizing the oxazine resin particles by heat treatment to obtain amorphous carbon-containing black particles.

Description

DESCRIPTION OF EMBODIMENTS

[0182] Embodiments of the present invention are more specifically described with reference to, but not limited to, examples below.

Example 1

[0183] In 1-butanol in an amount of 10 g were sequentially dissolved 1.0 g of 1,5-dihydroxynaphthalene (1,5-DHN, available from Tokyo Chemical Industry Co., Ltd.) and 0.8 g of 1,3,5-trimethylhexahydro-1,3,5-triazine (available from Tokyo Chemical Industry Co., Ltd.). Thus, a 1-butanol mixed solution was prepared.

[0184] Separately, 160 g of 1,4-dioxane and 10 g of ion exchange water were mixed to prepare an aqueous solution. The obtained aqueous solution was held at 40° C. with stirring, and the 1-butanol mixed solution was dropwise added thereto over six hours, followed by stirring for three hours. Thus, a particle dispersion was prepared.

[0185] To the particle dispersion were further added 180 g of ion exchange water and 180 g of 1-butanol, followed by removal of the solvent for recovery of the particles.

[0186] The infrared absorption spectrum of the particles was measured by Fourier transform infrared spectroscopy (FT-IR, NICOLET 6700). As a result, a peak (at 1334-1337 cm.sup.−1) derived from out-of-plane symmetric bending vibration (wagging mode) of CH.sub.2 in an oxazine ring and a peak (at 1232-1237 cm.sup.−1) derived from asymmetric stretching vibration (the asymmetric stretching mode) of —O—C in a naphthalene ring were simultaneously detected. This confirmed the presence of naphthoxazine in the particles.

[0187] The particles were subjected to heat treatment at 200° C. for two hours in a vacuum atmosphere. Thus, amorphous carbon particles as black particles were obtained.

[0188] The average particle size of the obtained amorphous carbon particles was measured by analysis of an FE-SEM image of the particles using image analysis software (WINROOF, available from Mitani Corporation). Also, the standard deviation was calculated to calculate the coefficient of variation (CV value) of the particle size from the obtained numerical value. Moreover, the sphericity was determined from the ratio between the minimum particle size and the maximum particle size to calculate the average sphericity. The average particle size was 90 nm, the CV value of the particle size was 15%, and the sphericity was 0.99. The specific surface area of the particles measured by a BET adsorption method was 20 m.sup.2/g.

[0189] The particles were analyzed using an X-ray diffractometer (SmartLab Multipurpose, available from Rigaku Corporation) under the conditions of X-ray wavelength: CuKα 1.54 A, measurement range: 2θ=10° to 70°, scanning rate: 4°/min, and step size: 0.02°. As a result, no peak was detected at the position of θ=26.4°.

[0190] The elemental composition of the amorphous carbon particles was determined by X-ray photoelectron spectroscopy (XPS) to detect nitrogen (N) in addition to carbon (C) and oxygen (O). The nitrogen content relative to the total of the three elements was 4.5 mol %.

[0191] The obtained particles were subjected to Raman measurement. The ratio between G band and D band was 0.8.

[0192] Whether the mass spectrum (around 77.12) derived from a benzene ring and the mass spectrum (around 127.27) derived from a naphthalene ring were present was determined by time-of-flight secondary ion mass spectrometry (TOF-SIMS) using a TOF.SIMS 5 (available from IONTOF GmbH). As a result, the mass spectrum derived from a benzene ring and the mass spectrum derived from a naphthalene ring were detected. The TOF-SIMS measurement was carried out under the following conditions. For minimizing contamination derived from a storage case or the air, a sample after production was stored in a clean case for storing silicon wafers.

<Measurement Condition>

Primary ion: 209Bi+1

[0193] Ion voltage: 25 kV
Ion current: 1 pA
Mass range: 1 to 300 mass
Analysis area: 500×500 μm
Charge prevention: electron irradiation neutralization
Random raster scan

[0194] As a result of the measurement of the diffuse reflectance spectrum of the amorphous carbon particles using a spectrophotometer equipped with an integrating sphere (V-760, available from Jasco Corp.), the average total light reflectance in the visible light region (wavelength of 400 to 800 nm) was 12%. Moreover, in that region, no absorption peak was observed.

[0195] Compounds shown in Table 1 were used as curable compounds and blended at the ratio shown in Table 1.

[0196] In addition, IRGACURE 907 (available from BASF SE) was used as a curing agent. Materials shown in Table 2 were blended at the ratio shown in Table 2 at room temperature. Thus, a resin composition was prepared.

Example 2

[0197] A particle dispersion was prepared as in Example 1, except that 0.8 g of 1,3,5-trimethylhexahydro-1,3,5-triazine was replaced with 0.968 g of methylamine having a concentration of 40% and 2.023 g of formaldehyde having a concentration of 37%.

[0198] As in Example 1, the presence of a naphthoxazine resin in the particles was confirmed.

[0199] Black particles were obtained as in Example 1, except that the obtained particles were subjected to heat treatment in a nitrogen atmosphere at 500° C. for two hours.

[0200] According to the measurement as in Example 1, the black particles had an average particle size of 50 nm, a specific surface area of 400 m.sup.2/g, a specific gravity of 1.7, a nitrogen content of 1.5 mol %, and an average total reflectance in the visible light region (wavelength of 400 to 800 nm) of 3%. No peak was detected at a position of θ=26.4°.

[0201] According to analysis of the obtained particles by Raman spectroscopy, the ratio between G band and D band was 2.1.

[0202] A resin composition was prepared as in Example 1, except that the obtained black particles were used.

Comparative Example 1

[0203] A resin composition was prepared as in Example 1, except that the amorphous carbon particles were replaced with titanium black (available from Mitsubishi Materials Corporation, average particle size: 90 nm).

Comparative Example 2

[0204] A resin composition was prepared as in Example 1, except that the amorphous carbon particles were replaced with carbon black (EC600JD, available from Lion Specialty Chemicals Co., Ltd., average particle size: 34 nm).

Comparative Example 3

[0205] A resin composition was prepared as in Example 1, except that the amorphous carbon particles were replaced with graphite particles (average particle size: 8 μm).

(Evaluation Method)

(1) Oil Absorption

[0206] Oil absorption was determined in conformity with JIS K 5101-13-1. A sample in an amount of 1 g from the amorphous carbon particles obtained in Example 1 was placed in the center of a measuring plate (3-mm-thick soda glass plate). To the center of the sample was gradually dripped refined linseed oil in a burette drop by drop. Each dripping was followed by sufficient kneading of the whole with a spatula.

[0207] The dripping of refined linseed oil and kneading were repeated. After the particles and oil were kneaded into a hard putty bulk, the dripping of refined linseed oil and kneading were further repeated. The end point of the operation was set just before sudden softening of the kneaded bulk by dripping of another drop of refined linseed oil. The operation was adjusted to set the operation time from start to the end point to about 10 minutes.

[0208] The amount of the refined linseed oil dripped from the burette till the end point was read and converted to the amount of the dripped oil per 100 g of the sample. The converted value was taken as the oil absorption value.

[0209] The measurement of the oil absorption was performed in the same manner for the amorphous carbon particles obtained in Example 2, titanium black used in Comparative Example 1, carbon black used in Comparative Example 2, and graphite particles used in Comparative Example 3.

(2) Specific Gravity

[0210] The specific gravity of the amorphous carbon particles obtained in Example 1 was measured using a dry automatic pycnometer (Accupyc II134, available from Shimadzu Corporation) (sample amount: 0.2 g).

[0211] The measurement of the specific gravity was performed in the same manner for the amorphous carbon particles obtained in Example 2, titanium black used in Comparative Example 1, carbon black used in Comparative Example 2, and graphite particles used in Comparative Example 3.

(3) Powder Resistance

[0212] The volume resistivity of the amorphous carbon particles obtained in Example 1 was measured using a powder resistivity measurement system (available from Mitsubishi Chemical Analytech Co., Ltd.) to obtain powder resistance at a load of 16 kN.

[0213] The measurement of the powder resistance was performed in the same manner for the amorphous carbon particles obtained in Example 2, titanium black used in Comparative Example 1, carbon black used in Comparative Example 2, and graphite particles used in Comparative Example 3.

(4) Optical Density of Coating Film (OD Value)

(Formation of Coating Film)

[0214] The resin compositions obtained in Examples 1 and 2 and Comparative Examples 1 to 3 were each applied with a knife coater to a glass slide preliminarily subjected to silane coupling agent treatment, followed by curing treatment under irradiation of UV light at a wavelength of 365 nm at an intensity of 6,000 mJ/cm.sup.2. Thus, a coating film was obtained.

(Measurement of Optical Density)

[0215] The optical density (OD value) of the obtained coating film was measured with a transmission densitometer (“Model 301”, available from X-Rite Inc.).

[0216] The resin composition of Comparative Example 2 had poor adhesion after curing, and powdery cured product fell off from the glass, failing to form a coating film. Accordingly, evaluation could not be performed.

[0217] The resin composition of Comparative Example 3 sedimented badly, failing to form an evaluable coating film. Accordingly, evaluation could not be performed.

(5) Shelf (Sedimentation) Stability

[0218] Each of the resin compositions obtained in Examples 1 and 2 and Comparative Examples 1 and 3 in an amount of 2 ml was put in a glass bottle (inner diameter of bottle mouth: 7.2 mm, body diameter: 16.5 mm, height: 40 mm), and allowed to stand still at 23° C. for 72 hours. The states of the amorphous carbon particles, titanium black, and carbon black were visually checked and evaluated based on the following criteria. No evaluation was performed on the resin composition of Comparative Example 2.

∘ (Good): No sedimentation was observed.
x (poor): Sedimentation was observed and a clear layer was observed at the upper part of the glass bottle.

TABLE-US-00001 TABLE 1 Weight Substance name Maker ratio Curable 2-Hydroxyethyl FUJIFILM Wako Pure 30 composition methacrylate (2HEMA) Chemical Corporation Diallyl phthalate FUJIFILM Wako Pure 10 Chemical Corporation Ditrimethylolpropane Shin-Nakamura Chemical 10 tetraacrylate Co., Ltd. Urethane acrylate Shin-Nakamura Chemical 10 (U-4HA) Co., Ltd.

TABLE-US-00002 TABLE 2 Resin composition Curable Curing Black particles Resin composition Black particles composition agent Average Powder OD value of Shelf Amount Amount Amount Oil absorption Specific particle size resistance coating film (sedimentation) Material (wt %) (wt %) (wt %) (ml/100 g) gravity (nm) Ω .Math. cm (per 1 μm) stability Example 1 Amorphous carbon 45 52.4 2.6 78 1.4 90 >10.sup.6 0.65 ∘ particles Example 2 Amorphous carbon 45 52.4 2.6 110 1.7 50 >10.sup.6 0.95 ∘ particles Comparative Titanium black 45 52.4 2.6 65 3.9 90 4.1 × 10.sup.−1 0.53 x Example 1 Comparative Carbon black 45 52.4 2.6 800 1.9 34 1.8 × 10.sup.−2 — — Example 2 Comparative Black lead 45 52.4 2.6 50 2.2 8000 1.5 × 10.sup.−3 — x Example 3 particles

INDUSTRIAL APPLICABILITY

[0219] The present invention can provide a resin composition having a high optical density and capable of providing a high-quality color filter excellent in long-term stability and insulation properties. The present invention can also provide a cured product of the resin composition, a black matrix, a color filter, a liquid crystal display device, an organic electroluminescent display device, and a method for producing the resin composition.