JPH1020439A - Photosensitive electrically nonconductive carbonaceous powder and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate formation of a thin film and to attain formation of a pattern in high precision by forming a fundamental structure composed of a fine carbonaceous powder and photosensitive insulating sol particles. SOLUTION: At least a part of the surfaces of the carbonaceous powder is covered with at least a part of each photosensitive insulating sol particle, thus permitting the fine carbonaceous particles to retain their intrinsic covering power and moreover to acquire the performances of the photosensitive particles, and consequently, to facilitate photopatterning. At least a part of the surfaces of the carbonaceous powder is covered with at least a part of each photosensitive insulating sol particle by synthesizing the photosensitive sol particles in the carbonaceous powder dispersion solution, or only by mixing the carbonaceous powder and the photosensitive sol particles alone or in a solvent. An amount of this solvent to be used is <=30weight% of the total solids, preferably, <=10weight%, at the time of the reaction, and the reaction proceeds sufficiently at a temperature near room temperature of 10-30 deg.C, and stirring of 100-500rpm revolution speed is satisfactory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-conductive carbonaceous powder having photosensitivity to irradiation of energy rays such as ultraviolet rays, and more particularly, to high light-shielding properties, blackness and non-conductivity. Non-conductive carbonaceous powder used in various applications, which can provide a non-conductive layer to colored printed circuit boards, shadow masks for cathode ray tubes, black matrices for liquid crystal color filters, etc. About.

[0002]

2. Description of the Related Art Conventionally, in the production of shadow masks for cathode ray tubes, black matrices for liquid crystal color filters, etc., paints that provide a non-conductive black coating layer have been required.
As a black pigment used in these paints, an iron oxide-based black pigment or a black pigment obtained by compounding an organic pigment such as yellow, red, and blue has been used. When the non-conductive black coating layer is used as a black matrix, a pattern forming property is required according to the shape of the color filter, and thus the black pigment is dispersed in a polymerizable compound.
An attempt has been made to form a pattern by irradiating an energy ray after forming a coating film to cure a polymerizable compound by an active species (radical) from a polymerization initiator added at the same time.

[0003]

However, coating films formed using these pigments have the drawback that the degree of black hiding is insufficient and that the materials themselves are expensive. Carbonaceous powders such as carbon black have been widely used as pigments for paints for the above applications because of their excellent blackness and inexpensiveness.However, carbonaceous powders are inherently conductive and have sufficient conductivity. In order to obtain blackness, a large amount of carbonaceous powder must be dispersed in a coating film composed of a cured product of a polymerizable compound. Therefore, when non-conductivity is required, carbonaceous powder is used. It is difficult. Carbonaceous powder is
Also, because it is present as an aggregate, it is easy to take a strong aggregate structure as the particle size becomes smaller, it is extremely difficult to uniformly disperse a large amount in a polymerizable compound having viscosity, even if it can be dispersed. However, since the carbonaceous powders form aggregates with time in the polymerizable compound, a stable quality coating liquid cannot be obtained.

[0004] Regarding the pattern formability, when a large amount of carbonaceous powder is contained in a polymerizable compound in order to impart black hiding power, the carbonaceous powder is hardened when the polymerizable compound is cured. Since the energy rays are shielded, the coating film is not sufficiently cured, so that sufficient substrate adhesion and coating film strength cannot be obtained. Furthermore, since the carbonaceous powder has the ability to capture radicals generated from the polymerization initiator and the polymerizable compound in the coating film, it hinders the curing of the coating film, leaving an uncured portion in the coating film and high precision. It becomes difficult to form a pattern.

[0005] The polymerization initiator used for curing the polymerizable compound often has an unstable structure in order to improve the sensitivity of energy rays, and is used as a coating solution for forming a non-conductive layer using the polymerization initiator. In such cases, the coating solution gradually increases in viscosity and gels, and the stability with time is often poor. In order to obtain a sufficient black concealing property, a large amount of a carbonaceous powder is used, and at the same time, a large amount of a polymerizable compound is used. As a result, the nonconductive layer has an excessive thickness of about 10 μm. Excessive thickness of the non-conductive layer is not preferable in the production of the filter because the performance thereof is deteriorated.

Accordingly, it is an object of the present invention to achieve a thinner film easily and to achieve a high-precision pattern formation as compared with the case of combining with a conventional polymerizable compound without being hindered from curing by carbonaceous powder. It is an object of the present invention to provide a photosensitive non-conductive carbonaceous powder which can be used and a method for producing the same.

[0007]

The above object is achieved by the present invention described below. That is, the present invention is a photosensitive non-conductive carbonaceous powder characterized by being basically composed of carbonaceous powder and insulating sol particles having photosensitivity,
And its manufacturing method.

[0008]

Next, the present invention will be described in more detail with reference to preferred embodiments. The photosensitive non-conductive carbonaceous powder of the present invention is characterized in that it is basically composed of carbonaceous powder and photosensitive sol particles having photosensitivity. By coating at least a part of the surface with at least a part of the insulating sol particles having photosensitivity, the carbonaceous powder retains its original black concealing property, as if it had photosensitivity. Behavior, and thus patterning with light is easier.

The method for producing a photosensitive non-conductive carbonaceous powder according to the present invention comprises the steps of synthesizing photosensitive sol particles in a carbonaceous powder dispersion solution, or combining the carbonaceous powder with the photosensitive sol. At least part of the surface of the carbonaceous powder is coated with at least part of the photosensitive sol particles by mixing the particles as they are or in a solution. Although there is no problem in the properties of the carbonaceous powder obtained by any of the methods, a method of generating photosensitive sol particles in a carbonaceous powder dispersion is preferred because the operation is the simplest.

With respect to the amount of the solvent used in the reaction, the solid content concentration is 30% by weight or less, preferably 10% by weight or less. If the solid content is too high, the carbonaceous powder may aggregate or settle during the reaction and during use.
In use, the solid content must be 0.01% by weight or more. If the solid content is too low, it becomes difficult to exhibit the characteristics of the thin film formed.

Although the temperature conditions in the above-mentioned production cannot be specified unconditionally depending on the kind of the target sol, it is usually from 0 to 120 ° C., and it reacts sufficiently even at around room temperature (10 to 30 ° C.). The conditions are not particularly limited.
In addition, the stirring speed during the production may be a normal stirring speed,
For example, a range of 100 to 500 rpm is sufficient. The reaction temperature is not particularly limited, and the generation reaction is improved by heating, but at the same time, a part of the sol particles becomes large (uneven photosensitivity) due to decomposition and recombination of the sol.
Stir at around room temperature for 5 hours or more, preferably 8 hours or more.

In the present invention, the photosensitive insulating sol particles are dispersed without using a polymerizable compound having a viscosity that makes it difficult to disperse the carbonaceous powder as a dispersion medium for the carbonaceous powder,
In addition, in order to disperse the carbonaceous powder in a solution having a low viscosity, it is possible to arbitrarily adjust the amount of the carbonaceous powder in the dispersion of the carbonaceous powder. Examples of the carbonaceous powder used in the present invention include carbon black such as Ketjen Black, acetylene black, and furnace black, natural and artificial graphite, and other carbon whiskers, carbon fiber, graphite fiber, and carbon. Short fibers such as nanotubes can be used. These carbonaceous powders can be used alone or in combination of two or more.

The particle diameter of the carbonaceous powder used in the present invention is preferably 100 μm or less, and particularly preferably 10 μm or less. When the particle size exceeds 100 μm, it is difficult to obtain a light-sensitive insulating carbonaceous powder. The lower limit of the particle size of the carbonaceous powder used in the present invention is not particularly limited. Generally, the diameter of the photosensitive insulating sol particles is smaller than that of the carbonaceous powder, that is, 0.001 μm.
The diameter of the carbonaceous powder is equal to or smaller than that of the light-sensitive insulating sol particles, and there is no problem. Can be used as a body.

The photosensitive insulating sol particles used in the present invention are defined as inorganic particles dispersed in a solution as a colloid, containing a polar group such as a hydroxyl group or an amide group on the particle surface, and having a specific crystal structure. It is a general term for so-called amorphous ultrafine particles.

The type of the photosensitive insulating sol particles used in the present invention is not particularly limited, but an inorganic metal salt which is a precursor of various inorganic substances capable of coating at least a part of the above carbonaceous powder. , An organic acid salt, an organometallic compound, an organometallic complex and a derivative thereof, from a so-called metal compound and / or a hydrolyzate or partial hydrolyzate or polycondensate of the metal compound or a mixture of two or more kinds thereof. You can choose.

A preferred example of the photosensitive insulating sol particles is a sol-gel method for producing a metal oxide film at a low temperature.
Organometallic compounds such as metal alkoxides which are precursors of metal oxides used in the gel method, and hydrolysates or partial hydrolysates or polycondensates of organometallic complex salts obtained by modifying metal alkoxides with complexing agents Species or a mixture of two or more species, and these sol particles have photosensitivity to ultraviolet light of a specific wavelength due to the presence of the polar group, and are patterned by utilizing this photosensitivity. It is known that a metal oxide film can be obtained (Polymer, vol. 44, 1995).

As other preferable types of the photosensitive insulating sol particles used in the present invention, inorganic materials having an insulating property can be preferably used. For example, Si ₃ N ₄ , Al ₂
Sol particles such as O ₃ , SiO, SiO ₂ , TiO ₂ , and Ta ₂ O ₃ , acetyl and benzylacetonate salts of metals such as aluminum, zirconium, and titanium, or alkanolamine salts, and hydrolysates and partial hydrolysis thereof But the present invention is not limited to these.

The particle size of the photosensitive insulating sol particles used in the present invention is suitably in the range of 0.001 μm to 1 μm as described above. The sol particles are “reactive fine particles” having adhesiveness to a substrate, adhesion to a carbonaceous powder surface, coating and forming properties after application and heating in a solution, and a particle diameter of less than 0.001 μm. If it exceeds 1 μm, the reactivity is lost, which is not preferable. It is known that these photosensitive insulating sol particles have an absorption capacity (absorption band) in a specific wavelength region of ultraviolet light, and that the photosensitive insulating sol particles are irradiated with ultraviolet light of the specific wavelength. so,
The so-called sol-gel reaction of hydrolysis and polycondensation of the sol particles proceeds, and a corresponding metal compound film can be formed.

It is known that sol particles having these properties form a strong film when applied to a substrate and heated, and in a sol solution, the sol particles are dispersed and stabilized with respect to the carbonaceous powder. Acts as an agent, and when applied on a substrate, the above-mentioned sol particles easily react with the surface of the substrate, so that a film made of a simple substance powder is easily formed on the surface of the substrate via the sol particles. can do.

The amount of the sol particles added to the carbonaceous powder is sufficient to cover at least a part of the carbonaceous powder, and is smaller than that of a polymerizable compound which is a conventional dispersion medium of carbonaceous powder. The polymerizable compound is used even when the volume of the sol particles is 1/10 or less, sufficiently expressing its function (inhibiting the chain between carbonaceous powders and having both sufficient photosensitivity and substrate adhesion). Thin film (5 μm or less) which is difficult to realize in some cases
In addition, it is possible to easily produce a non-conductive layer having both black concealing properties and high insulating properties. Although the amount of the sol particles added to the carbonaceous powder cannot be particularly limited for the above reasons,
Preferably about 0.1 to 7 per 100 parts by weight of carbonaceous powder
The range is 0 parts by weight.

Further, when a film is formed using the non-conductive carbonaceous powder of the present invention, the film can be easily made thinner than when a polymerizable compound is used as a carbonaceous dispersion medium. Since the energy rays used for curing the coating film can be used efficiently, and the mechanism for curing the coating film does not utilize active species (radicals) from the polymerization initiator, the radical scavenging of the carbonaceous powder is The performance can be almost neglected, and as a result, it is possible to easily provide a coating solution having an extremely simple composition and excellent stability over time.

The photosensitive non-conductive carbonaceous powder obtained in the present invention is composed of the carbonaceous powder and the photosensitive insulating sol particles, and at least a part of the surface of the carbonaceous powder. By being coated with at least a part of the sol particles,
It is possible to impart sufficient photosensitivity to the carbonaceous powder itself, without using a polymerizable compound that degrades the properties of a conventional coating film, and to provide a thin film with sufficient pattern forming properties and light shielding properties.

[0023]

The present invention will be described more specifically with reference to the following examples. In addition, in an example, a part means a weight part. Example 1 (1) Photosensitive insulating sol particle dispersion solution Aluminum-sec-butoxide 5 parts Benzoylacetone 4 parts Isopropyl alcohol 91 parts A mixture consisting of 21 parts was stirred and mixed at 25 ° C for 12 hours, and aluminum-sec-butoxide butoxy was mixed. A part of the group was replaced with benzoylacetone to obtain a photosensitive insulating sol particle dispersion.

(2) Coating of Carbonaceous Powder with Photosensitive Insulating Sol Particles 95 parts of the photosensitive insulating sol particle dispersion of (1) above, MCF # 970 (Mitsubishi Chemical's carbon black pigment) 5 The mixture was stirred at 25 ° C. for 3 hours to perform a treatment for adsorbing sol particles on the surface of carbon black.

(3) Confirmation of Partial Coating of Carbon Black Surface with Photosensitive Insulating Sol Particles The dispersion obtained in (2) above was centrifuged to precipitate carbon black, and isopropyl alcohol was added again. After performing the steps of washing by ultrasonic irradiation and performing a centrifugal separation process, the carbon black after performing the process until the aluminum component eluted in the supernatant is no longer observed, and dried at 120 ° C. for 1 hour, and then subjected to pH 4 water To obtain a dispersion of carbon black partially coated with alumina.

Next, the untreated carbon black, the alumina obtained from the sol particles, and the 被覆 -potential of the alumina-coated carbon black of the present invention were measured, and the results were as follows. Ζ-potential of untreated carbon black: -18 mV Alumina: +16 mV ζ-potential of alumina-treated carbon black: +12 mV Based on the above data, the carbon black treated with aluminum zonal surface was sufficiently cleaned as described above. Suggests that alumina exists, and it can be seen that a part of the aluminum zone particles formed by the method of the above-mentioned example covered the surface of the carbon black particles.

(4) Coating film formation and pattern formation The photosensitive carbon black dispersion solution of the present invention obtained above is spin-coated on a glass substrate and dried at room temperature.
A μm coating was obtained. After covering a part of the dried coating film with an ultraviolet ray cut film, it was irradiated with ultraviolet rays having an intensity of about 150 mW / cm ² and immersed in an acidic aqueous solution having a pH of 3; The irradiated part remained on the substrate without being dissolved. By heating the coating film after immersion in the acidic aqueous solution at 120 ° C. for 1 hour, a patterned carbon black coating film firmly adhered to the glass substrate could be obtained.

(5) Measurement of Volume Resistance The volume resistance values of MCF # 970 alone and the carbonaceous powder in Examples are shown below. The volume resistance value is obtained by dispersing 50% by weight of carbonaceous powder in an epoxy resin, applying the dispersion on a glass substrate on which an ITO film has been formed, drying at 150 ° C. for 90 minutes, and measuring the resistance value in the thickness direction. The following results were obtained. # Even from 970 10 ⁵ [Omega] cm Example 1 10 ¹⁰ [Omega] cm or more data, the carbon black of Example 1, compared with # 970 alone film, the surface is coated with alumina, the insulating treatment is performed You can see that.

Example 2 MCF # 970 (Mitsubishi Chemical's carbon black pigment)
5 parts of aluminum-sec-butoxide and 4 parts of benzoylacetone were added to a dispersion obtained by dispersing 5 parts in 91 parts of isopropyl alcohol, and the mixture was stirred at 25 ° C. for 12 hours, and one of butoxy groups of aluminum-sec-butoxide was added. By replacing the part with benzoylacetone, the photosensitive insulating sol particles are generated, and at the same time, a part of the photosensitive insulating sol particles is adsorbed on the surface of the carbon black particles by electrostatic attraction during the generation process. A dispersion was obtained. Thereafter, the same results as in Example 1 were obtained in the same manner as in Example 1.

Example 3 The same as Example 1 except that 5 parts of zirconium-n-butoxide and 4 parts of acetylacetone were used instead of 5 parts of aluminum-sec-butoxide and 4 parts of benzoylacetone. Was obtained. Example 4 Instead of 5 parts of aluminum-sec-butoxide and 4 parts of benzoylacetone, titanium isopropoxide 5
And the same result as in Example 2 was obtained in the same manner as in Example 2 except that 4 parts by weight and 4 parts of benzoylacetone were used.

Example 5 A mixture consisting of 5 parts of aluminum-sec-butoxide, 4 parts of benzoylacetone and 91 parts of isopropyl alcohol was stirred at 25 ° C. for 12 hours.
By substituting a part of the butoxy group of c-butoxide with benzoylacetone, a photosensitive insulating sol particle dispersion was obtained. The obtained photosensitive insulating sol particle dispersion solution could be isolated as fine particles by drying under reduced pressure while maintaining the photosensitive property. These microparticles are transferred to MCF # 97
0 (Mitsubishi Chemical's carbon black pigment) and 0.1 to 7
By mixing with a powder mixer in the range of 0 parts, the photosensitive fine particles are adsorbed on the surface of the carbon black particles,
It was confirmed that the photosensitivity was imparted to the surface of the carbon black particles. Hereinafter, the same results as in Example 1 were obtained in the same manner as in Example 1. In addition, 5 parts of the above isolated fine particles were added to 9 parts.
Similar results were obtained when dispersed in 5 parts of isopropyl alcohol and then mixed with carbon black particles.

[0032]

As described above, according to the present invention, the carbonaceous powder itself is provided with photosensitivity by coating at least a part of the surface of the carbonaceous powder with the photosensitive insulating sol particles. It is possible to provide a light-sensitive non-conductive carbonaceous powder capable of forming a sufficient pattern-forming property and light-shielding property without using a polymerizable compound that deteriorates the properties of the coating film.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location // C01B 31/02 101 C01B 31/02 101B

Claims (10)

[Claims] 1. A photosensitive non-conductive carbonaceous powder, which is basically composed of carbonaceous powder and photosensitive sol particles having photosensitivity. 2. The photosensitive non-conductive carbonaceous powder according to claim 1, wherein at least a part of the surface of the carbonaceous powder is coated with at least a part of photosensitive sol particles having photosensitivity. 3. The photosensitive non-conductive carbonaceous powder according to claim 1, wherein the carbonaceous powder is one or a mixture of two or more kinds selected from graphite, carbon black and short fiber carbon fiber. body. 4. The photosensitive non-conductive carbonaceous powder according to claim 1, wherein the particle diameter of the carbonaceous powder is 100 μm or less. 5. The photosensitive non-conductive material according to claim 1, wherein the insulating sol particles having photosensitivity are a metal compound and / or a hydrolyzate or partial hydrolyzate or polycondensate of the metal compound. Carbonaceous powder. 6. The metal compound is an inorganic metal salt, an organic acid salt,
Organometallic compounds, organometallic complexes and their derivatives 1
6. The photosensitive non-conductive carbonaceous powder according to claim 5, which is a mixture of two or more species. 7. The photosensitive non-conductive carbonaceous powder according to claim 1, wherein the particle diameter of the photosensitive sol particles is 0.001 to 1 μm. 8. Photosensitive insulating sol particles are produced in a solvent in which the carbonaceous powder is dispersed, and the photoresponsive insulating sol particles are formed on at least a part of the surface of the carbonaceous powder. A method for producing a photosensitive non-conductive carbonaceous powder, comprising adsorbing at least a part of sol particles. 9. The carbonaceous powder and the insulating sol particles having photosensitivity are mixed as they are, and at least a part of the insulating sol particles having photosensitivity is coated on at least a part of the surface of the carbonaceous powder. A method for producing a photosensitive non-conductive carbonaceous powder, characterized by adsorbing. 10. A carbonaceous powder and insulating sol particles having photosensitivity are mixed in a liquid, and at least a part of the insulating sol particles having photosensitivity is coated on at least a part of the surface of the carbonaceous powder. A method for producing a photosensitive non-conductive carbonaceous powder, characterized by adsorbing.