JPS5927924A - Composite powder of spherical inorganic substance/resin and its production - Google Patents

Abstract

PURPOSE:A composite powder having a high functional property and capable of forming powder coatings, composite pigments, toners used in duplication, and moldings, prepared by uniformly coating the surfaces of spherical resin particles with fine inorganic powder. CONSTITUTION:The titled powder comprising spherical inorganic resin composite particles, prepared by uniformly coating the surfaces of spherical resin particles, particle diameter of 1-3,000mum, with inorganic fine powder, particle diameter of 0.02-10mum. A high-functional property powder can be obtained by using conductive fine powder, strongly dielectric fine powder, ferromagnetic fine powder, fine pigment powder or the like as the inorganic fine powder. 1-20pts.wt. said inorganic fine powder is dispersed in 100pts.wt. hydrophobic vinyl monomer containing water and a polymerization initiator to obtain an oil-in-water emulsion in which the inorganic fine powder is present in the interface between the monomer phase (oil phase) and the water phase, and this emulsion is suspension-polymerized to form the titled composite particles.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inorganic-resin composite powder comprising spherical inorganic-resin composite particles whose surfaces are uniformly coated with inorganic fine particles, and a method for producing the same.

In general, resins are lightweight and have excellent flexibility, making them easy to process, and have traditionally been processed or molded into solid shapes and used for various purposes.

In recent years, with the aim of expanding the uses of resin, resins have been made to have conductivity and
Attempts have been made to impart electrical and magnetic functions such as ferroelectricity and ferromagnetism, as well as functions such as pigment properties.

Examples of methods for imparting functions such as resin V, electrical, magnetic functions, and pigment properties include 1θ·l resin and inorganic fine particles such as conductive fine particles, ferromagnetic fine particles, ferroelectric fine particles, and pigment fine particles. There are known methods such as simply mixing or mixing with a powder, mixing and then pulverizing, and a method in which fine inorganic particles are present during the suspension polymerization reaction of a polymerizable monomer.

By simply mixing the resin and the inorganic fine particle powder, or by kneading and mixing and then pulverizing, it is difficult to disperse the inorganic fine particle powder in the resin, and the distribution tends to be uneven. The resulting resin particles have the disadvantage of exhibiting an irregular shape.

When +H fat particles mixed with such inorganic fine particle powder are used as they are or after being further processed and molded, functional properties such as conductivity, ferroelectricity, and ferromagnetism cannot be uniformly obtained. It's hard to get caught.

On the other hand, as a method for making inorganic fine particles present during the suspension polymerization reaction of polymerizable monomers, for example,
6-164503, JP-A-53-30680, JP-A-53-80598, JP-A: = a
-77'842"8... No. 5, JP-A-50-27
079 Publication, Japanese Patent Publication No. 51-46552, Japanese Patent Publication No. 51-24313, Japanese Patent Publication No. 60-33915, Japanese Patent Publication No. 49-30702, Japanese Patent Publication No. 46-93
There is a method described in Publication No. 47, but in any case,
The present invention relates to a method of containing inorganic fine particles inside resin particles.

In this way, when resin particles containing inorganic fine particles inside are used as they are or after being further processed and molded, the functional properties of the inorganic fine particles are hidden by the resin, so that high functional properties cannot be obtained. It has the disadvantage that it is difficult to obtain.

In view of the above, the present inventor has made extensive studies to obtain an inorganic-resin composite powder in which the distribution of inorganic fine particles is uniform and has high functional characteristics. is a mixture of water and a hydrophobic vinyl monomer containing a polymerization initiator or a mixture of a hydrophobic vinyl monomer and a copolymerizable monomer with a particle size of 0.02 to 10/
In the presence of j m inorganic → fine particle powder, the above-mentioned seven
or 1 inorganic fine particle powder per 100 parts by weight of the mixture
By dispersing and mixing at a ratio of ~20 parts by weight, an oil-in-water emulsion with inorganic fine particles present at the interface between the monomer phase (oil phase) and the aqueous phase is formed.
The present invention was completed based on the discovery that by carrying out a polymerization reaction, an inorganic-resin composite powder having a uniform distribution of inorganic fine particles and high functional properties can be obtained.

That is, the present invention provides spherical inorganic-resin composite particles in which the surface of spherical resin particles having a particle size of 1 to 3000 μm is uniformly coated with inorganic fine particle powder having a particle size of 0.02 to 10 μm. An inorganic material-resin composite powder, water, and a hydrophobic vinyl monomer containing a polymerization initiator or a mixture of a hydrophobic vinyl monomer and a copolymerizable monomer are mixed in the presence of an inorganic fine particle powder with a particle size of 0.02 to 10 μm. An oil-in-water mixture in which inorganic fine particles are present at the interface between the monomer phase (oil cake) and the water phase by dispersing and mixing 1 to 20 parts by weight of the above-mentioned inorganic fine particles per 100 parts of the monomer or mixture. By forming a mold emulsion bottle and then carrying out a suspension polymerization reaction, spherical inorganic-resin composite particles in which the surfaces of spherical resin particles are uniformly coated with the inorganic fine particle powder are produced. This is a method for producing a characteristic inorganic material-resin powder.

Next, the technical background that led to the completion of the present invention and the configuration of the present invention will be described.

In order to obtain inorganic-resin composite particles having a uniform distribution of inorganic fine particles and high functional properties, the present inventors believe that in order to obtain inorganic-resin composite particles that have a uniform distribution of inorganic fine particles and high functional characteristics, the inventors believe that instead of containing inorganic fine particles inside resin particles, spherical resin particles are used. It was considered important that the particles be inorganic-resin particles whose surfaces are uniformly coated with inorganic fine particle powder.

As a result of various studies on obtaining inorganic-resin composite particles in which the surface of spherical resin particles is coated with inorganic fine particle powder, the present inventor discovered that hydrophobic vinyl monomers containing water and a polymerization initiator Or a mixture of a hydrophobic vinyl monomer and a copolymerizable monomer in the presence of inorganic fine particles having a particle size of 0.02 to 10 μm, and 1 to 20 parts of the above inorganic fine particles per 100 parts by weight of the monomer or mixture. Water in which inorganic fine particles are present at the interface between an oil phase and an aqueous phase, which are composed of a hydrophobic vinyl monomer or a mixture of a hydrophobic vinyl monomer and a copolymerizable monomer by dispersing and mixing them in proportions of 1 part to 1. A novel invention in which it is possible to obtain spherical inorganic-resin composite particles in which the surfaces of spherical resin particles are uniformly coated with inorganic fine particles by forming an oil-type emulsion and then carrying out a suspension polymerization reaction. I gained a lot of knowledge.

Water and a hydrophobic vinyl monomer containing an initiator or a mixture of a hydrophobic vinyl monomer and a copolymerizable monomer are added to the monomer or mixture in the presence of inorganic fine particles having a particle size of 0.02 to 10 μm. By dispersing and mixing 1 to 20 parts by weight of the above inorganic fine particles per 100 parts by weight, an oil-in-water emulsion in which the inorganic fine particles are present at the interface between the oil phase and the aqueous phase is formed, and then suspended. Although the theoretical elucidation of the phenomenon in which spherical inorganic-resin composite particles are obtained in which the surface of spherical resin particles is uniformly coated with inorganic fine particle powder when a polymerization reaction is carried out is still unclear, The present inventor believes that this is because the inorganic fine particles gather at the interface between the aqueous phase and the oil phase and stably exist in an equilibrium state upon initiation of the suspension-combination reaction.

The phenomenon in which the inorganic fine particles of the present invention aggregate at the interface between the aqueous phase and the oil phase and stably exist in an equilibrium state will be described in detail below. In order for the inorganic fine particles to aggregate at the interface of the aqueous phase and the oil phase to stably exist in an equilibrium state, it is necessary to The balance of interfacial energy is maintained, the size of the inorganic fine particles is such that it does not settle, and the inorganic fine particles are in efficient contact with the oil phase and the water phase. We believe that it is important to satisfy conditions such as ensuring that the inorganic substances (particulate-absorbing powder) are dispersed as well as possible, and that the inorganic substances (particulate-absorbing powder) are collected at the interface between the aqueous phase and the oil phase, Al is formed, and an equilibrium state is achieved. Various studies have been conducted regarding the conditions for Vc to exist stably in
As a result, water and a hydrophobic vinyl monomer containing a polymerization initiator or a mixture of a hydrophobic vinyl monomer and a copolymerizable monomer are mixed in the presence of inorganic fine particles having a particle size of 0.02 to 10.11 m. and the monomer or mixture 10
When dispersed and mixed at a ratio of 1 to 20 parts by weight of the above-mentioned inorganic material [dead particles powder] to 0 parts by weight, the inorganic fine particles aggregate at the interface between the aqueous phase and the oil phase and stably exist in an equilibrium state. found.

Incidentally, in the present invention, a dispersion stabilizer, which is normally used in suspension polymerization reactions, is not required. This fact is based on the fact that in the case of the present invention, the balance of interfacial energy between the inorganic fine particle powder, the water phase and the oil phase is maintained as described above, so that the inorganic fine particle powder This is thought to be because it exists stably at the interface.

Next, various conditions for implementing the present invention will be described.

The types of inorganic fine particles used in the present invention are those that provide functional properties such as conductivity, ferroelectricity, and ferromagnetism, and include ruthenium oxide fine particles having high conductivity, At01
Zinc oxide fine particle powder containing ~20% by weight, Sb (-< means +1 titanium oxide fine particle powder or tin oxide fine particle powder containing 0.1 to 2.0% by weight of Nb, TI or Sn 0.5% by weight).
Ferric oxide fine particle powder containing 1 to 20 nitrides, LI of 2.
One or more types of nickel oxide fine particle powder or acid 1 hvanadium fine particle powder containing 0 City Jt%, A B 01 type oxide with ferroelectricity (However, for humans,
, "One or two or more selected from Mg, B is 'r + , one or two or more selected from Z r % Sn XN b]-), the above A containing a rare earth element
B One or more types of OL oxide, ferromagnetic iron fine particles, iron-based alloy fine particles, magnetite fine particles, magnetite fine particles, cobalt-modified spinel type iron oxide late particle powder, dioxide One or more types of chromium fine particle powder, one or more types of hematite fine particle powder with pigment properties, lead oxide fine particle powder, and titanium oxide fine particle powder can be used. Size of inorganic fine particle powder. It is necessary for the monomer droplets to be sufficiently protected from coalescence, and for the inorganic fine particles to aggregate at the interface between the aqueous phase and the oil phase without settling and exist stably in an equilibrium state. Inorganic fine particle powder of .02 to 10 μm can be used. Particle size is 0.02μ
When the temperature is less than m, the agglomeration of -order particles becomes stronger,
It becomes difficult to maintain a stable distribution state.

When the particle size is 10 μm or more, the particles may stably exist at the interface between the aqueous phase and the oil phase, but quickly settle due to gravity.

The amount of inorganic fine particles present in the present invention is 1 to 20 parts by weight based on 100 parts by weight of the hydrophobic vinyl monomer.

If it is less than 1 part by weight, it is not sufficient to coat the surface of the spherical resin particles, and if it is more than 20 parts by weight, some remains without being completely attached to the surface of the spherical resin particles. come.

The inorganic fine particles can be present either in the hydrophobic vinyl monomer containing the polymerization initiator or in the aqueous phase.

In this case, the inorganic fine particle powder can of course be present directly in the hydrophobic vinyl-based polymer containing the polymerization initiator or in the aqueous phase, but the inorganic fine particle powder can be prepared in advance by adding ethanol to the inorganic fine particle powder. Good dispersion can be achieved by adding water to the organic solvent to create an open phase.

The monomers used in the present invention include monomers or mixtures of monomers that can produce hydrophobic polymers by suspension polymerization, such as alkyl acrylates, alkyl methacrylates, styrene, vinyl chloride, vinylidene chloride, and vinyl acetate.

The polymerization initiator used in the present invention should be one that is soluble in the monomer, such as benzoyl peroxide, lauroyl peroxide, dihythyl peroxide, methyl ethyl peroxide, etc., which are commonly used. Acid north and south are used.

The amount of polymerization initiator used is 0.2 to 10 times the amount of monomer or monomer mixture.

If it is less than 02 Ichikichi, the polymerization rate will be extremely slow, making it unsuitable for practical polymerization reactions.

If it is 10 or more, the polymerization rate is high, but the degree of polymerization decreases, making it unsuitable for practical polymerization reactions.

In the present invention, the method of mixing and dispersing the inorganic fine particle powder in an aqueous phase or a monomer containing a polymerization initiator, and mixing and dispersing water and a monomer containing a polymerization initiator in the presence of the inorganic fine particle powder is usually carried out for cylinders. Mechanical methods such as those described above are sufficient, and are particularly effective when using a high-speed rotation homogenizer, ultrasonic waves, or the like.

The atmosphere for the suspension reaction in the present invention is N! to avoid the influence of oxygen in the air. , A", etc., but it can also be carried out in air.

#The turbidity reaction can be carried out at a temperature range of 20 to 900℃. If the temperature is below 20°C, a practical polymerization rate cannot be obtained, and if it is above 900°C, phenomena harmful to the polymerization reaction, such as f)h clouding of the reaction mixture, may occur. The spherical inorganic-resin composite particles, which are wax product particles, have a particle diameter of 1 to 3000.11 m.

The size of the product particles tends to increase as the amount of inorganic fine particles present relative to the monomer increases, and as the amount of monomer relative to the aqueous phase increases. Moreover, the larger the number of enemies of the polymerization initiator to the monomer and the faster the stirring speed during the suspension polymerization reaction, the smaller the ratio tends to be.

The size of the product particles is fit! Depending on the purpose of use,
All you have to do is select r.

The spherical inorganic-resin composite particles of the present invention explained above are as follows:
Since the surface of the spherical resin particles is uniformly covered with inorganic fine particles, the distribution of the particles after the cutting machine is even -C, and the particles have a high performance life.

The spherical inorganic-resin powder obtained in the present invention can be used as a paint for powder coating, a composite pigment, a toner for abdominal photography, and a carrier for photographing. The inorganic material-resin composite particles can be processed and J-molded to be used as a molded body.

Next, the present invention will be specifically explained using Examples and Comparative Examples.

Example 1 1 g of granular hematite particles having an average particle diameter of 0.2 μm was mixed and dispersed in 200 mL of water, and 1.0 g of benzoyl peroxide was added to the aqueous solution. After adding 20 g of methyl methacrylate containing Og, ultrasonic waves were irradiated for 10 seconds to prepare an oil-in-water emulsion.

The above emulsion was stirred using a high-speed rotating homogenizer at a temperature of 80'C under a Nt gas flow at a stirring speed of QOOr.
Suspension polymerization reaction was carried out at pm for 5 hours. After the suspension polymerization reaction was completed, the resulting polymer particles were washed with water, separated and dried. The resulting polymer particles were spherical particles with an average particle diameter of 70 μm, and the particle surfaces were uniformly coated with hematite particles.

Examples 2 to 12 The amount of water, type and amount of monomer, type of inorganic fine particle powder, average particle size and appetizer, type and amount of polymerization initiator, temperature and stirring speed of suspension polymerization reaction were varied. Polymer particles were obtained in the same manner as in Example 1 except for this.

The produced polymer particles obtained in Examples 2 to 12 were
As a result of mirror observation, the surface of each particle was uniformly coated with inorganic fine particle powder.

In Example 8, the acicular maghemite particles were dispersed and mixed in styrene containing lauroyl peroxide, and then the average particle diameter of the compound particles was as shown in Table 1.
After adding it to 400 mL of water, it was irradiated with ultrasonic waves for 10 seconds to prepare a dispersion suspension.

In Example 11, the acicular maghemite particles were once dispersed in denatured alcohol, and then dispersed in 380% water.
+n l was mixed and dispersed.

Comparative Example 1 Using 5.0g of granular hematite particles (monomer 10
This corresponds to a 25mm section compared to the 0 electric switch section. ) The suspension polymerization reaction was carried out in the same manner as in IJ 1 except that.

As a result of electron microscopic observation, it was found that a large amount of aggregated granular hematite was attached to the surface of the resulting polymer particles, and many aggregates of free hematite were also observed.

Example 13 3 g of resin particles with an average particle diameter of 6011 and whose surface was covered with ruthenium oxide obtained in Example 5 were charged into a mold with a heater and an inner diameter of 16 mm, and heated to 1°O while applying a pressure of 36 kg/Cm2. / m r n to soften and melt the resin, and while maintaining the above pressure, cooled to room temperature to obtain a tablet with a thickness of about 3 ffffl+ and a diameter of 101111 mm. Next, electrodes with lead wires soldered to 6ffn1 square silver plates were adhered to both sides of this tablet using conductive paste.
After drying, the electrical resistance was measured and showed a specific resistance of 1120 cm. A photomicrograph of the surface of this resin particle is shown in Figure 1, and a photomicrograph of the cut surface of the tab knot is shown in Figure 2. According to FIG. 2, it can be seen that the ruthenium oxide has a network structure and forms channels. The volume concentration of ruthenium oxide relative to the resin was measured by placing the resin particles on a thermobalance (VC) and found that the volume concentration of ruthenium oxide was 08%.

On the other hand, when the surface of a composite body made by dispersing and mixing 50 μm commercially available polystyrene beads and 1.7 g of ruthenium oxide fine powder in ethanol and then volatilizing the ethanol at 70°C was observed with an electron microscope, ruthenium oxide was observed. was observed to adhere to the polystyrene beads in a patchy manner, and aggregates of ruthenium oxide powders were also observed. The volume concentration of ruthenium oxide was measured by placing the resin particles on a thermobalance and found it to be 2.5 cm. Next, a tablet was molded using the above method and the electrical resistance was measured; the result was 21 x 10”Ω.
(It showed a resistivity of m.) When the cut surface of this tablet was observed with an electron microscope, the ruthenium oxide layer was uneven and the network structure was incomplete, and lumps of ruthenium oxide aggregated in places. was observed.

[Brief explanation of drawings]

FIG. 1 is a photograph substituted for a drawing of the surface of the produced polymer particles obtained by the present invention, and FIG. 2 is a photograph substituted for a drawing showing the cut surface of a molded product. 4f-iza+t”+t・youΔ1! (9daOimode 1b) Representative Patent Attorney Kunihiko Wakabayashi Figure 1'1 Figure 2

Claims (1)

[Claims] 1. The surface of the spherical resin particles having a particle size of 1 to 3000, (j m) has a particle size of 0.02 to 10, It m
A spherical inorganic-resin composite powder comprising spherical inorganic resin-resin composite particles uniformly coated with inorganic fine particle powder. 2. The spherical inorganic-resin composite powder according to claim 1, wherein the inorganic fine particles are conductive fine particles. 3. The conductive fine particle powder is ruthenium oxide fine particle powder,
Zinc oxide fine particle powder containing 01 to 2.0% by weight of At, S
b Strictly speaking, titanium oxide fine particles powder or tin oxide fine particle powder containing 0.1 to 2.0% by weight of Nb, Ti or 8n
Ferric oxide fine particle powder containing 0.1 to 2.0% by weight, L
One selected from nilaglu oxide fine particle powder or vanadium oxide fine particle powder containing 0.1 to 20% by weight of L, or -
4. The spherical inorganic substance-resin composite powder according to claim 1, wherein the inorganic substance and the fine particle powder are ferroelectric fine particle powders. Composite powder. 5. The ferroelectric fine particle powder is an ABO type oxide (where A is one or more selected from BaXpb, Od, 8r, and Mg, and B is one or more selected from Ti1Zr, 8n, and Nb). species), the above A B containing rare earth elements
The spherical inorganic-resin composite powder according to claim 4, which is one or more selected from Os-type oxides. 6. The spherical inorganic-resin composite powder according to claim 1, wherein the inorganic fine particles are ferromagnetic fine particles. 7. The ferromagnetic fine particles are one or more selected from iron fine particles, iron-based alloy fine particles, magnetite fine particles, magnetite fine particles, cobalt-modified spinel type iron oxide fine particles, and chromium dioxide fine particles. A spherical inorganic-resin composite powder according to claim 6. 8. The spherical inorganic-resin composite powder according to claim 1, wherein the inorganic fine particles are pigment fine particles. 9. The spherical inorganic-resin composite powder according to claim 8, wherein the pigment fine particles are one or more selected from hematite fine particles, lead oxide fine particles, and titanium oxide fine particles. 10. Water and a hydrophobic vinyl monomer containing a polymerization initiator, or a mixture of a hydrophobic vinyl monomer and a copolymerizable polymer, in the presence of inorganic fine particle powder with a particle size of 0.02 to 10 μm, as described above. An oil-in-water emulsion in which the inorganic fine particles are present at the interface between the monomer phase (oil phase) and the aqueous phase by dispersing and mixing 1 to 20 parts by weight of the above inorganic fine particles per 100 parts by weight of the monomer or mixture.
The method is characterized by forming spherical inorganic-resin composite particles in which the surface of the spherical resin particles is uniformly coated with the inorganic fine particle powder by forming a spherical resin particle and then carrying out a suspension-combination reaction. A method for producing a spherical inorganic-resin composite powder. 11. The method for producing a spherical inorganic-resin composite powder according to claim 10, wherein the inorganic fine particles are conductive fine particles. 12. The conductive fine particles are ruthenium oxide fine particles, oxidized lead fine powder containing 0.1 to 20% by weight of At, s
Titanium oxide fine particles or tin oxide fine particles containing 0.1 to 2.11% of Ti or Nb, ferric oxide fine particles containing 0.1 to 2.0% by weight of Ti or 8n, Li
The spherical inorganic substance-resin composite powder according to claim 11, which is one or more selected from nickel oxide fine particles or vanadium oxide fine particles, which has a weight gain of 0.1 to 2.0. manufacturing method. 13. The method for producing a spherical inorganic-resin composite powder according to claim 10, wherein the inorganic fine particles are ferroelectric fine particles. 14. Ferroelectric fine particle powder is A I30. type oxide (however, A is one or more selected from BaX pb od, Sr, Mg, B is one or more selected from Ti, Zr. 8n, Nb), rare earth element. 14. The method for producing a spherical inorganic-resin composite powder according to claim 13, wherein the powder is one or more selected from the above ABOs type oxides. 15. The method for producing a spherical inorganic-resin composite powder according to claim 10, wherein the inorganic fine particles are ferromagnetic fine particles. 16 The ferromagnetic fine particles are selected from iron fine particles, iron-based alloy fine particles, magnetite fine particles, magnetite fine particles, cobalt-modified spinel type iron oxide fine particles, and chromium dioxide fine particles. Special I that is more than a species? F. A method for producing silkworms using spherical inorganic-resin powder according to claim 15. 17. The method for producing a spherical inorganic-resin composite powder according to claim 10, wherein the inorganic fine particles are pigment fine particles. 1B. The method for producing a spherical inorganic-resin composite powder according to claim 17, wherein the pigment fine particles are one or more selected from hematite fine particles, lead oxide fine particles, and titanium oxide fine particles C. .