POWDER FOR FORMING BLACK LIGHT-SHIELDING FILM AND METHOD FOR MANUFACTURING SAME

Abstract

The present invention provides a powder for forming a black light-shielding film having a specific surface area of 20 to 90 m.sup.2/g, which is measured by the BET method, comprising zirconium nitride as a main component, and containing magnesium and/or aluminum. If containing the magnesium, the content of the magnesium is 0.01 to 1.0% by mass relative to 100% by mass of the powder for forming a black light-shielding film, and if containing the aluminum, the content of the aluminum is 0.01 to 1.0% by mass relative to 100% by mass of the powder for forming the black light-shielding film.

Claims

1. A powder for forming a black light-shielding film having a specific surface area of 20 to 90 m.sup.2/g, which is measured by the BET method, comprising a zirconium nitride powder as a main component, and containing magnesium and/or aluminum, characterized in that: if containing the magnesium, the content of the magnesium is 0.01 to 1.0% by mass relative to 100% by mass of the powder for forming a black light-shielding film, and if containing the aluminum, the content of the aluminum is 0.01 to 1.0% by mass relative to 100% by mass of the powder for forming the black light-shielding film.

2. A method for manufacturing powder for forming a black light-shielding film by mixing zirconium dioxide powder, metallic magnesium powder, magnesium oxide powder or magnesium nitride, and aluminum oxide powder or aluminum nitride powder so that the metallic magnesium is 25 to 150% by mass relative to 100% by mass of the zirconium dioxide, the magnesium oxide is 15 to 500% by mass relative to 100% by mass of the zirconium dioxide, and the aluminum oxide or the aluminum nitride is 0.02 to 5.0% by mass relative to 100% by mass of the zirconium dioxide, firing the obtained mixed power under an atmosphere of a sole nitrogen gas, under an atmosphere of a mixed gas of a nitrogen gas and a hydrogen gas, under an atmosphere of a mixed gas of a nitrogen gas and an ammonium gas, or under an atmosphere of a mixed gas of a nitrogen gas and an inert gas at a temperature of 650 to 900 C. to reduce the mixed powder.

3. A black photosensitive composition which contains the powder for forming the black light-shielding film according to claim 1 as a black pigment.

4. A method for forming a black light-shielding film using the black photosensitive composition according to claim 3.

5. A black photosensitive composition which contains the powder for forming a black light-shielding film manufactured by the method according to claim 2 as a black pigment.

6. A method for forming a black light-shielding film using the black photosensitive composition according to claim 5.

Description

EXAMPLES

[0042] Next, Examples of the present invention will be explained in detail together with Comparative Examples.

Example 1

[0043] To 7.4 g of a monoclinic zirconium dioxide powder having an average primary particle diameter calculated from the specific surface area measured by the BET method of 50 nm were added 7.3 g of metallic magnesium powder having an average primary particle diameter of 100 m and 3.6 g of magnesium oxide powder having an average primary particle diameter of 20 nm, further 0.04 g of aluminum oxide having an average primary particle diameter of 20 nm is added, and uniformly mixed by a reaction apparatus in which a graphite boat has been internally mounted in a glass tube made of quartz. At this time, an amount of the metallic magnesium added was 98% by mass relative to 100% by mass of the zirconium dioxide, an amount of the magnesium oxide added was 49% by mass relative to 100% by mass of the zirconium dioxide, and an amount of the aluminum oxide added was 0.5% by mass relative to 100% by mass of the zirconium dioxide. The above-mentioned mixture was fired under an atmosphere of the nitrogen gas at a temperature of 700 C. for 60 minutes, thereby practicing a nitrogen reaction of zirconium oxide to obtain a fired product. This fired product was dispersed in 1 liter of water, 17.5% hydrochloric acid was gradually added thereto to carry out washing at a pH of 1 or more while maintaining a temperature to 100 C. or lower followed by adjusting a pH to 7 to 8 with 25% aqueous ammonia, and the mixture was filtered. The filtered solid content was redispersed in water with 400 g/liter, and subjected to acid washing, pH adjustment with aqueous ammonia and filtered once again in the same manner as mentioned above. Thus, after repeating acid washing-pH adjustment by aqueous ammonia twice, the filtrate was dispersed in ion exchange water with 500 g/liter in terms of the solid content, and after subjecting to stirring under heating at 60 C. and adjustment of a pH to 7, the mixture was filtered by a suction filtration apparatus, further washed with an equal amount of ion exchange water, and dried in a hot air dryer at a set temperature of 120 C. to obtain a powder for forming a black light-shielding film comprising zirconium nitride as a main component.

Example 2

[0044] 0.06 g of aluminum nitride powder having an average primary particle diameter of 100 nm was used instead of aluminum oxide powder. At this time, the addition amount of aluminum nitride was 0.8% by mass relative to 100% by mass of zirconium dioxide. A powder for forming a black light-shielding film comprising zirconium nitride as a main component was obtained in the same manner as in Example 1 except for this.

Comparative Example 1

[0045] To 7.4 g of a monoclinic zirconium dioxide powder having an average primary particle diameter calculated from the specific surface area measured by the BET method of 50 nm were added 7.3 g of metallic magnesium powder having an average primary particle diameter of 100 m and 0.7 g of a magnesium oxide powder having an average primary particle diameter of 20 nm, further 0.04 g of oxide aluminum having an average primary particle diameter of 20 nm is added, and uniformly mixed by a reaction apparatus in which a graphite boat has been internally mounted in a glass tube made of quartz. At this time, an amount of the metallic magnesium added was 98% by mass relative to 100% by mass of the zirconium dioxide, an amount of the magnesium oxide to be added was 10% by mass relative to 100% by mass of the zirconium dioxide, and an amount of the aluminum oxide added was 0.5% by mass relative to 100% by mass of the zirconium dioxide. The above-mentioned mixture was fired under an atmosphere of the nitrogen gas at a temperature of 700 C. for 60 minutes, thereby practicing a nitrogen reaction of zirconium dioxide to obtain a fired product. This fired product was dispersed in 1 liter of water, 17.5% hydrochloric acid was gradually added thereto to carry out washing at a pH of 0.5 or more while maintaining a temperature to 100 C. or lower followed by adjusting a pH to 7 to 8 with 25% aqueous ammonia, and the mixture was filtered. The filtered solid content was redispersed in water with 400 g/liter, and subjected to acid washing, pH adjustment with aqueous ammonia and filtered three times again in the same manner as mentioned above. Thus, after repeating acid washing-pH adjustment by aqueous ammonia twice, the filtrate was dispersed in ion exchange water with 500 g/liter in terms of the solid content, and after subjecting to stirring under heating at 60 C. and adjustment of a pH to 7, the mixture was filtered by a suction filtration apparatus, further washed with an equal amount of ion exchange water, and dried in a hot air dryer at a set temperature of 120 C. to obtain a powder for forming a black light-shielding film of Comparative Example 1 comprising zirconium nitride as a main element.

Examples 3 to 6 and Comparative Examples 2 to 6

[0046] With respect to Examples 3 to 6 and Comparative Examples 3 to 6, in the same manner as Example 1, an addition ratio (% by mass) of metallic magnesium powder, magnesium oxide power, aluminum oxide powder and aluminum nitride powder relative to zirconium dioxide, types of reaction gases which are atmospheric gases, a ratio thereof in terms of % by volume, a firing temperature, and a firing time are respectively set, and powders for forming a black light-shielding film were manufactured as shown in Table 1.

TABLE-US-00001 TABLE 1 Production conditions of powder for forming black light-shielding film Metallic Mg/ Al.sub.2O.sub.3/ Firing Mg/ZrO.sub.2 ZrO.sub.2 ZrO.sub.2 AlN/ZrO.sub.2 Reaction gas temper- Firirng (% by (% by (% by (% by atmosphere ature time mass) mass) mass) mass) (vol % ratio) ( C.) (min) Exam- 98 49 0.5 N.sub.2 = 100% 700 60 ple 1 Exam- 98 49 0.8 N.sub.2 = 100% 700 60 ple 2 Exam- 98 15 0.02 N.sub.2 = 100% 650 30 ple 3 Exam- 50 500 5.0 N.sub.2 + H.sub.2 = 90%:10% 650 30 ple 4 Exam- 150 50 0.3 N.sub.2 = 100% 900 60 ple 5 Exam 25 15 1.5 N.sub.2 = 100% 700 60 ple 6 Com- 98 10 0.5 N.sub.2 = 100% 700 60 para- tive Exam- ple 1 Com- 98 15 0.01 N.sub.2 = 100% 700 60 para- tive Exam- ple 2 Com- 98 15 6.0 N.sub.2 + H.sub.2 = 90%:10% 700 60 para- tive Exam- ple 3 Com- 98 g 550 1.0 N.sub.2 = 100% 700 60 para- tive Exam- ple 4 Com- 160 g 35 0.4 N.sub.2 = 100% 950 60 para- tive Exam- ple 5 Com- 20 49 2.2 N.sub.2 + H.sub.2 = 90%:10% 650 30 para- tive Exam- ple 6

<Comparative Test and Evaluation 1>

[0047] The powders for forming a black light-shielding film of the final products obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were each used as a sample, and by the methods mentioned in detail hereinbelow, (1) a specific surface area, (2) contents by amount of magnesium and/or aluminum, (3) light transmittance in a dispersion at a powder concentration of 50 ppm, and (4) OD values when kept at a room temperature after being manufactured, (5) OD values when kept for 500 hours under an atmosphere of a high temperature and a high humidity of 85 C. and a relative humidity of 85% after being manufactured. The respective measurement results are shown in Table 2.

(1) Specific surface area: With regard to all the samples, by using a specific surface area measurement apparatus (SA-1100, manufactured by SIBATA SCIENTIFIC TECHNOLOGIES, LTD.), a specific surface area value was measured according to the single point BET method by nitrogen adsorption.
(2) Contents by amount of magnesium and/or aluminum: Contents by amount of magnesium and aluminum were measured by ICP light emission spectrometry measurement (Optima 4300DV manufacture by PerkinElmer Co., Ltd.).
(3) Spectral curve of dispersion with powder concentration of 50 ppm: With respect to each of the samples of Examples 1 to 6 and Comparative Examples 1 to 6, these samples were separately placed in a circulating horizontal type bead mill (media: zirconia), and an amine-based dispersing agent was added to carry out dispersing treatment in a propylene glycol monomethyl ether acetate (PGM-AC) solvent. The obtained eleven kinds of the dispersions were diluted 100,000-fold and a powder concentration was adjusted to 50 ppm. The light transmittance of each sample of the diluted dispersion was measured in the wavelength range from 240 nm to 1,300 nm using Hitachi High-Tech Fielding Corporation (UH-4150), and each of the light transmittance (%) at the wavelength of 370 nm near the i-line (365 nm) and at the wavelength of 550 nm was measured.

TABLE-US-00002 TABLE 2 Light transmittance OD value at OD value under with powder room high temperature Composition concentration temperature and high humidity Final analysis of 50 ppm Visible Near Visible Near product of final Light Light light infrared light infrared Specific product transmit- transmit- transmit- light transmit- light surface Mg Al tance tance tance shielding tance shielding area (% by (% by (370 (550 (560 ability (560 ability (m.sup.2/g) mass) mass) nm) nm) nm) (650 nm) nm) (650 nm) Exam- 40 0.65 0.25 22.0 4.0 3.8 3.3 3.8 3.3 ple 1 Exam- 50 0.15 0.55 23.4 4.3 3.6 3.4 3.6 3.4 ple 2 Exam- 25 0.01 0.01 16.5 3.4 4.0 3.8 3.9 3.8 ple 3 Exam- 90 1.00 1.00 29.6 6.7 3.1 3.0 3.1 3.0 ple 4 Exam- 20 0.02 0.15 10.1 3.0 3.9 3.8 3.9 3.8 ple 5 Exam- 70 0.01 0.60 24.0 6.8 3.0 3.0 3.0 3.0 ple 6 Compar- 35 0.001 0.25 21.7 3.6 3.7 3.5 3.5 3.2 ative Exam- ple 1 Compar- 30 0.02 0.002 21.9 3.5 4.1 3.6 3.6 3.1 ative Exam- ple 2 Compar- 65 0.02 1.50 19.4 7.0 2.9 2.7 2.9 2.7 ative Exam- ple 3 Compar- 75 1.50 0.50 30.5 8.5 2.8 2.5 2.8 2.5 ative Exam- ple 4 Compar- 19 0.40 0.20 9.0 3.1 4.2 3.8 3.8 3.5 ative Exam- ple 5 Compar- 92 0.70 1.00 31.0 7.0 2.8 2.4 2.8 2.4 ative Exam- ple 6

<Comparative Test and Evaluation 2>

[0048] An acrylic resin was added to the dispersion used for the measurement of the light transmittance of the samples obtained in Examples 1 to 6 and Comparative Examples 1 to 6 with a ratio of the black pigment:the resin=6:4 in a mass ratio, and mixed to prepare black photosensitive compositions. The composition was spin-coated onto a glass substrate so that the film thickness after firing became 1 m, and fired at a temperature of 250 C. for 60 minutes to form a film. The film was kept at a room temperature, and the OD values of visible light (center wavelength: 560 nm and center wavelength: 650 nm) of the film were measured using a densitometer (densitometer) having the product name of X-Rite 361T(V) manufactured by Macbeth Co., based on the above-mentioned equation (2). The OD values of the same film, which was kept for 500 hours under an atmosphere of a high temperature and a high humidity at 85 C. and a relative humidity of 85%, were measured in the same manner. The results are shown in Table 2.

[0049] As is apparent from Table 2, in Comparative Example 1, pH when washing a fired object was made to be 0.5 which was low, a content of magnesium in a powder for forming a black light-shielding film of the final product was extremely little. As a result, OD values under a high temperature and a high humidity were lowered by 0.2 and 0.3 respectively in central wavelengths of 560 nm and 650 nm compared with values at a room temperature, and the final product was inferior in resistance to weather.

[0050] In Comparative Example 2, a content of aluminum in a powder for forming a black light-shielding film of the final product was 0.002% by mass which was too little, so OD values under a high temperature and a high humidity compared with values at a room temperature were lowered by 0.5 in central wavelengths of 560 nm and 650 nm, and the final product was inferior in resistance to weather

[0051] In Comparative Example 3, a content of aluminum in a powder for forming a black light-shielding film of the final product was 1.50% by mass which was too much, so OD values at a room temperature and OD values under a high temperature and a high humidity were both 2.9 or less, and the final product was inferior in the light-shielding property.

[0052] In Comparative Example 4, a content of magnesium in a powder for forming a black light-shielding film of the final product was 1.5% by mass which was too much, so OD values at a room temperature and OD values under a high temperature and a high humidity were both 2.8 or less, and the final product was inferior in the light-shielding property.

[0053] In Comparative Example 5, a specific surface area of a powder for forming a black light-shielding film of the final product was 19 m.sup.2/g which was too small, so light transmittance at a wavelength of 370 nm in a dispersion with a powder concentration of 50 ppm was 9.0% which was low, and was inferior in light transmittance of an ultraviolet ray.

[0054] In Comparative Example 6, a specific surface area of a powder for forming a black light-shielding film of the final product was 92 m.sup.2/g which was too large, so light transmittance at a wavelength of 550 nm in a dispersion with a powder concentration of 50 ppm was 7.0% which was high, and was inferior in light transmittance of visible light.

[0055] To the contrary, in Examples 1 to 6, specific surface areas of powders for forming a black light-shielding film in the final product were 20 to 90 m.sup.2/g, so respective light transmittances at a wavelength of 370 nm and at a wavelength of 550 nm in a dispersion with a powder concentration of 50 ppm were 10.1 to 29.6% and 3.0 to 6.8%, and OD values at a room temperature and OD values under a high temperature and a high humidity were 3.0 or more and the OD values under a high temperature and a high humidity did not change compared with the OD values at a room temperature. From the above results, it was found that the powders for forming a black light-shielding film of the final products of Examples 1 to 6 are advantageous in transmittance of ultraviolet rays, transmittance of a visible light, a light shielding performance, and resistance to weather.

UTILIZABILITY IN INDUSTRY

[0056] The powder for forming a black light-shielding film comprising zirconium nitride as a main element of the present invention can be utilized for a high precision liquid crystal, a black matrix material for organic EL, a light shielding material for an image sensor, a light shielding material for an optical element, a light shielding filter, an IR cut filter, and the like.