JPH1020438A - Photosensitive fine particle dispersion and method for producing the same - Google Patents

Abstract

(57) Abstract: Provided is a photosensitive fine particle dispersion in which formation of a functional film which is difficult to produce by a sol-gel method and pattern formation thereof can be easily performed at a low temperature. SOLUTION: A photosensitive fine particle dispersion solution which is basically composed of fine particles and photosensitive sol particles, and a method for producing the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a photosensitivity to irradiation of energy rays such as ultraviolet rays, and when a coating film is formed, at least a part of the surface of the fine particles is coated with the irradiated parts and the non-irradiated parts. The present invention relates to a photosensitive fine particle dispersion solution capable of directly providing a patterned fine particle film without requiring a photoresist because the solubility of the photosensitive sol particles changes, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, fine particles having electrical properties (such as conductivity), magnetic properties (such as magnetism), and optical properties (such as polarizing property) have been dispersed in a polymerizable compound. Attempts have been made to form a pattern of a fine particle-dispersed film by utilizing the fact that a polymerizable compound is cured by irradiating an energy ray after forming a coating film.

[0003] In the above-mentioned trials, in order to impart certain characteristics, particularly electric characteristics, to the fine particle dispersed film by the fine particles dispersed in the coating film, the fine particles are uniformly dispersed in the film while contacting each other. It is necessary to do the binder
However, there is a problem that a polymer from a polymerizable compound used as a material hinders contact between the fine particles and it is difficult to obtain the original characteristics of the fine particles. Therefore, it is necessary to mix a large amount of the fine particles into the film uniformly. Further, when forming a fine particle dispersion film, since the precision of patterning mainly depends on the particle diameter of the fine particles, when a fine and high precision pattern is required, the particle diameter of the fine particles is reduced. There is a need.

[0004]

Generally, fine particles are present as agglomerates, and the smaller the particle size, the easier it is to adopt a strong agglomerated structure. Therefore, a large amount of fine particles are generally dispersed in a polymerizable compound having a high viscosity. It is extremely difficult, even if it can be dispersed, because the fine particles form aggregates over time in the polymerizable compound after dispersion,
A stable quality coating liquid cannot be obtained.

When the particle size of the fine particles is relatively large, the fine particles shield the energy rays when the polymerizable compound is cured, so that the coating film is not sufficiently cured and the polymerizable compound remains in the coating film. In addition, the film quality deteriorates with the decrease of the coating film strength. Furthermore, some metal oxide fine particles used as fine particles have the ability to absorb energy rays and the ability to scavenge radicals generated from the polymerizable compound, and thus hinder the curing of the coating film. It is difficult to form a highly accurate pattern. In addition, a part of the metal oxide fine particles having an energy ray absorbing ability, by absorbing energy rays, also has an action of promoting the deterioration of the polymer as a binder, thereby reducing the temporal stability of the coating film. There's a problem.

In order to solve the above problems, organometallic compounds such as metal alkoxides, which are precursors of metal oxides, are used in a sol-gel method which is a method of forming a metal oxide film at a low temperature. A part of the hydrolyzate or partial hydrolyzate of an organometallic complex salt obtained by modifying a metal alkoxide with a complexing agent has photosensitivity to ultraviolet light of a specific wavelength, and using this photosensitivity, Attempts have been made to obtain patterned metal oxide films (polymer, 44 vol.
1995). However, the types of metal oxides that can be manufactured by this method are significantly limited, and firing at high temperatures is required to form a metal oxide film having a sufficient function, so that the base material is thermally damaged. It is not possible to use a plastic film or the like which is easily affected by heat, and furthermore, the volume of the plastic film or the like shrinks significantly due to heating, so that it is very difficult to form a pattern with high precision.

Accordingly, an object of the present invention is to provide fine particles having various functions and sol particles having the same characteristics as the fine particles and having photosensitivity in order to realize high-precision pattern formation at a low temperature. By preparing a fine particle dispersion solution comprising, further, by coating at least a part of the surface of the fine particles with at least a part of the sol particles, imparts photosensitivity to the fine particles themselves, and reduces the properties of a conventional coating film By providing a photosensitive fine particle dispersion solution and a method for producing a functional film which does not use a polymerizable compound and which is difficult to produce by a sol-gel method, and whose pattern formation can be easily performed at a low temperature. is there.

[0008]

The above object is achieved by the present invention described below. That is, the present invention is a photosensitive fine particle dispersion solution which is basically composed of fine particles and photosensitive sol particles, and a method for producing the same. In the above, the fine particles can have various functions, and at least a part of the surface of the fine particles can be coated with at least a part of the photosensitive sol particles.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in more detail with reference to preferred embodiments. The photosensitive fine particle dispersion solution of the present invention is composed of fine particles having various functions and sol particles having photosensitivity, preferably at least a part of the surface of the fine particles is at least a part of the photosensitive sol particles. This is a photosensitive fine particle dispersion solution that is coated and contains composite fine particles that behave as if they have light sensitivity while maintaining the original properties of the fine particles.

The method for producing a photosensitive fine particle dispersion solution according to the present invention comprises synthesizing photosensitive sol particles in the fine particle dispersion solution, or mixing the fine particles and the photosensitive sol particles as they are or in a solution. And coating at least a part of the surface of the fine particles with at least a part of the photosensitive sol particles. Although there is no problem in the characteristics of the fine particles obtained by any of the methods, a method of producing photosensitive sol particles in a fine particle dispersion is preferred because the operation is the simplest. Regarding the amount of the solvent used in this reaction, the solid content concentration is 30% by weight or less, preferably 10% by weight or less. If the solid concentration is too high, there is a possibility that agglomeration or sedimentation of fine particles may occur 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, a polymerizable compound having a high viscosity, in which fine particles are difficult to disperse, is not used as a dispersion medium for fine particles,
Since the fine particles are dispersed in a sol particle solution in which photosensitive sol particles are dispersed and the viscosity is not high, the fine particles are easily dispersed regardless of the amount of the fine particles. It is possible to arbitrarily adjust the addition amount of the fine particles from the amount obtained to a small amount expected to have a slight effect.

As the fine particles used in the present invention, inorganic materials such as Au, Al, Cu, Cr, Ti, Pt, Mo, and
W, Al / Si, Pt / Si, Mo / Si, Ti / S
i, Ta / Si, etc., and as a resistive film application, for example, Cr, Ta, Re, TaN, TiN, NiCr, S
iCr, TiCr, SnO ₂ , In ₂ O _{3 and the} like. Examples of the dielectric film application include AlN, BN, and Si.
_{3 N 4, Al 2 O 3} , BeO, SiO, SiO 2, Ti
O ₂ , Ta ₂ O ₅ , HfO ₂ , PbO, MgO, Nb ₂
O ₅ , Y ₂ O ₃ , ZrO ₂ , BaTiO ₃ , LiNbO
₃ , PbTiO ₃ , PLZT, ZnS and the like.

As an insulating film application, for example, Si ₃ N ₄ ,
Al ₂ O ₃ , SiO, SiO ₂ , TiO ₂ , Ta ₂ O ₅
And magnetic film applications such as Fe, C
o, Ni, Ni-Fe, Te-Fe, Gd, Co, and the like. For superconducting film applications, for example, Nb, NbN,
Nb ₃ Sn, Nb ₃ Ge, Nb ₃ Si and the like can be mentioned, and as a semiconductor film application, for example, Ge, Si, Se, Te,
SiC, ZnO, ZnSe, CdSe, CdTe, Cd
S, PbS, PbO ₂ , GaAs, GaP, GaN, M
n / Co / Ni / O and the like.
For example, Si ₃ N ₄ , SiO, SiO _{2 and the} like can be mentioned.

As a selective absorption film application, for example, SiO /
Cr, ZrO ₂ / Al, Cr / Cr ₂ O _{3, and the} like. Examples of sensor material applications include SiC, Se, and G.
e, for example, ZnS, I
_{TO, Cr-Cu, SnO 2} , Al 2 O 3, Si 3 N,
Examples of the optical recording material include Al and Au.
Te-C, Te-Se, TeOx-Ge-Sn, and the like. For magneto-optical recording, for example, Gd-Fe, T
bFe, GdTbFe, TbDyFe, and the like. Examples of the optical industrial member include SiO ₂ , TiO ₂ , and Sn.
O ₂ , In ₂ O ₃ , ZrO _{2 and the} like can be mentioned. The fine particles described above are typical examples used in the present invention, but the present invention is not limited to these.

On the other hand, examples of the organic substance among the fine particles used in the present invention include synthetic polymer fine particles and organic dyes, but the present invention is not limited to these. The particle diameter of the fine particles used in the present invention is 100
μm or less, and more preferably 10 μm or less. When the particle size exceeds 100 μm, it is difficult to form a photosensitive fine particle dispersion film.

The lower limit of the particle size of the fine particles used in the present invention is not particularly limited. Generally, the particle size of the photosensitive sol particles is small relative to the fine particles, and those having a range of 0.001 μm to 1 μm are used. However, even when the particle size of the fine particles is equal to or smaller than the particle size of the photosensitive sol particles. No problem,
It can be used as a photosensitive fine particle dispersion.

The photosensitive sol particles used in the present invention include:
It is a general term for so-called amorphous ultrafine particles that can be dispersed as a colloid in a solution, have a polar group such as a hydroxyl group or an amide group on the particle surface, and do not have a specific crystal structure.

It is known that sol particles having these characteristics form a strong film when applied to a substrate and heated, and act as a dispersion stabilizer for added fine particles in a liquid. When applied on a substrate, the sol particles readily react with the surface of the substrate, and thus have an effect of easily forming a film composed of fine particles on the surface of the substrate via the sol particles. At this time, by selecting the photosensitive sol particles having the same characteristics (electrical, magnetic, photochemical characteristics, etc.) as the fine particles, there is almost no deterioration in the characteristics of the coating film due to the use of the polymerizable compound. In some cases, the characteristics can be improved as compared with a film consisting of fine particles alone.

As the photosensitive sol particles, various ones can be selected as needed. For example, when the photosensitive sol particles are used for an optical member, the photosensitive sol particles have a refractive index different from that of the fine particles. By using the conductive sol particles, it is possible to arbitrarily change the optical properties of the obtained coating film.

Further, by coating a part of the surface of the fine particles with the light-sensitive sol particles, the fine particles themselves can be given photosensitivity, and the sol particles covering the surface of the fine particles serve as a binder for the fine particles. Because it also acts, when the binder is expensive, or when it is difficult to synthesize a large amount, furthermore the application where the amount of the binder is extremely limited, for example, when using a plurality of particles, a monodispersed thin film of fine particles, or conversely It can be used without problems in applications such as stacking several layers of fine particles regularly to form a functional film, or in applications where energy rays need to efficiently reach the inside of a thick film of fine particles with high opacity to energy rays. It becomes possible.

The amount of the sol particles added to the fine particles is
An amount that covers at least a part of the fine particles is sufficient, and is 1 / (1) of that of a polymerizable compound which is a conventional dispersion medium of fine particles.
Even when the volume of sol particles is 10 or less, the function is sufficiently exhibited, and a thin film (5 μm or less), which is difficult to realize when a polymerizable compound is used, can be easily produced. The amount of the sol particles added to the fine particles is not particularly limited for the above-mentioned reason, but is preferably in the range of about 0.1 to 70 parts by weight per 100 parts by weight of the fine particles.

The particle size of the photosensitive sol particles 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 base material, adhesion to fine particle surfaces, coating and forming properties after application and heating in a solution, and a particle diameter of less than 0.001 μm or 1 μm. It is not preferable to exceed the value because the reactivity is lost.

The type of the photosensitive sol particles used in the present invention is not particularly limited, but an inorganic metal salt, an organic acid salt, an organic acid salt, which is a precursor of various inorganic substances which can be used for dispersing the above-mentioned fine particles. It can be selected from metal compounds, so-called metal compounds which are organometallic complexes and their derivatives, and / or one or more mixtures of hydrolysates or partial hydrolysates or polycondensates of the metal compounds. . Specific examples of the sol particles include acetyl and benzylacetonate salts of metals such as aluminum, zirconium, and titanium, or alkanolamine salts, and their hydrolysates and partial hydrolysates.

It is known that these photosensitive sol particles have an absorption capacity (absorption band) in a specific wavelength range of ultraviolet light, and by irradiating the photosensitive sol particles with ultraviolet light of the specific wavelength. Then, a so-called sol-gel reaction such as hydrolysis or polycondensation of sol particles proceeds, and a corresponding metal compound film is formed.

The photosensitive fine particle dispersion of the present invention comprises fine particles and photosensitive sol particles as described above. Preferably, at least a part of the surface of the fine particles is coated with at least a part of the sol particles. By providing photosensitivity to the fine particles themselves, without using a polymerizable compound that reduces the properties of conventional coating films, and the production of a functional film that is difficult to produce by the sol-gel method, and This is a fine particle dispersion liquid that can easily form patterns at low temperatures.

[0027]

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

(2) Coating Treatment of Magnesium Oxide Fine Particle Powder with Photosensitive Sol Particles 95 parts of the photosensitive sol particle dispersion solution of the above (1) Magnesium oxide fine particle powder (MgO fine particles, 100A, manufactured by Ube Industries) 5 The mixture was stirred at 25 ° C. for 3 hours to perform a treatment for adsorbing sol particles on the surface of the magnesium oxide fine particles.

(3) Confirmation of Partial Coating of the Surface of Magnesium Oxide Fine Particles with Photosensitive Sol Particles The dispersion obtained in the above (2) is centrifuged to precipitate the magnesium oxide fine particles, and isopropyl alcohol is added again. After performing the steps of washing by ultrasonic irradiation and performing a centrifugal separation process, the magnesium oxide fine particles obtained after performing the process until aluminum components eluted in the supernatant are no longer observed, dried at 120 ° C. for 1 hour, and then adjusted to pH 8 It was dispersed in water to obtain a dispersion of magnesium oxide fine particles partially coated with alumina.

Next, the untreated magnesium oxide fine particles,
The ζ-potential of the alumina obtained from the sol particles and the alumina-coated magnesium oxide fine particles of the present invention was measured, and the results were as follows. Ζ-potential of untreated magnesium oxide fine particles: +23 mV Alumina: -12 mV ζ-potential of alumina-treated magnesium oxide fine particles: −8 mV Based on the above data, magnesium oxide fine particles treated with aluminum zone were thoroughly washed as described above. This suggests that alumina is present on the surface, and it can be seen that a part of the aluminumzonal particles formed by the method of the above-mentioned example covered the surface of the magnesium oxide fine particles.

(4) Formation of Coating Film and Pattern Formation The dispersion of the photosensitive magnesium oxide fine particles of the present invention obtained above was spin-coated on a glass substrate and dried at room temperature to obtain a coating film of 1 μm. After covering a part of the dried coating film with an ultraviolet cut film, the strength is about 150 mW / cm ^2.
Irradiated with an ultraviolet ray and immersed in an acidic aqueous solution of pH = 3, the non-irradiated portion was completely dissolved, and the irradiated portion remained on the substrate without being dissolved. The coating film after immersion in an acidic aqueous solution
By heating for a time, a coated film of patterned magnesium oxide fine particles firmly adhered to the glass substrate could be obtained.

Example 2 Magnesium oxide fine particles (manufactured by Ube Industries, MgO fine particles,
100A) 5 parts of aluminum-sec-butoxide and 4 parts of benzoylacetone were added to a dispersion obtained by dispersing 5 parts of 91 parts of isopropyl alcohol,
By stirring for 2 hours and substituting a part of the butoxy group of aluminum-sec-butoxide with benzoylacetone, the photosensitive insulating sol particles are generated, and at the same time, some of the photosensitive insulating sol particles are In the process of formation, a dispersion was obtained which was adsorbed on the surface of magnesium oxide fine particles by electrostatic attraction. Thereafter, the same results as in Example 1 were obtained in the same manner as in Example 1.

Example 3 The procedure of Example 1 was repeated 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, and zirconium oxide fine particles were used as fine particles. Similarly, the same result as in Example 1 was obtained. Example 4 Instead of 5 parts of aluminum-sec-butoxide and 4 parts of benzoylacetone, titanium isopropoxide 5
And 4 parts of benzoylacetone, and the same result as in Example 2 was obtained in the same manner as in Example 2, except that titanium oxide fine particles were used as fine particles.

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, and the mixture 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. By mixing these fine particles with magnesium oxide fine particles (Ube Industries, Ltd., MgO fine particles, 100A) in a range of 0.1 to 70 parts by a powder mixer, the photosensitive fine particles are adsorbed on the surfaces of the magnesium oxide fine particles. It was confirmed that photosensitivity was imparted to the surface of the magnesium oxide fine particles. Hereinafter, the same results as in Example 1 were obtained in the same manner as in Example 1. Similar results were obtained by dispersing 5 parts of the above isolated fine particles in 95 parts of isopropyl alcohol, and then mixing them with magnesium oxide fine particles.

[0035]

As described above, according to the present invention, at least a part of the surface of the fine particles having a certain function is coated with the light-sensitive sol particles, thereby imparting the light sensitivity to the fine particles themselves. To provide a photosensitive fine particle dispersion in which a functional film which does not use a polymerizable compound for deteriorating properties and which is difficult to produce by a sol-gel method, and whose pattern can be easily formed at a low temperature. Becomes possible.

Claims (10)

[Claims] 1. A photosensitive fine particle dispersion solution, which is basically composed of fine particles and photosensitive sol particles. 2. The method according to claim 1, wherein at least a part of the surface of the fine particles is coated with at least a part of the photosensitive sol particles.
The photosensitive fine particle dispersion according to the above. 3. The fine particles are composed of one or more metals, inorganic substances such as oxides, nitrides, sulfides, fluorides and carbides thereof and / or organic substances such as synthetic polymers, natural polymers and organic dyes. 3. The photosensitive fine particle dispersion according to claim 1, which is one or a mixture of two or more kinds selected from the group consisting of: 4. The photosensitive fine particle dispersion according to claim 1, wherein the fine particles have a particle diameter of 100 μm or less. 5. The method according to claim 1, wherein the photosensitive sol particles comprise a metal compound and / or
3. The photosensitive fine particle dispersion according to claim 1, which is a hydrolyzate, a partial hydrolyzate or a polycondensate of a metal compound. 6. The metal compound is an inorganic metal salt, an organic acid salt,
Organometallic compounds, organometallic complexes and their derivatives 1
6. The photosensitive fine particle dispersion according to claim 5, which is a mixture of two or more species. 7. The photosensitive sol particles having a particle diameter of 0.0
The photosensitive fine particle dispersion according to claim 1, 2 or 5, having a diameter of from 01 µm to 1 µm. 8. Photosensitive sol particles are generated in a solvent in which fine particles are dispersed, and at least a part of the surface of the fine particles is
A method for producing a photosensitive fine particle dispersed solution, comprising adsorbing at least a part of the generated photosensitive sol particles. 9. A dispersion of a photosensitive fine particle dispersion solution, wherein the fine particles and the photosensitive sol particles are mixed as they are, and at least a part of the photosensitive sol particles is adsorbed on at least a part of the surface of the fine particles. Production method. 10. A photosensitive fine particle dispersion solution comprising: mixing fine particles and photosensitive sol particles in a liquid; and adsorbing at least a part of the photosensitive sol particles to at least a part of the surface of the fine particles. Manufacturing method.