JPH05301967A - Production of composite spherical substance powder composed of inorganic substance particle and organic substance - Google Patents

Abstract

PURPOSE:To obtain a composite spherical substance powder, excellent in fluidity, composed of an inorganic substance particles and an organic substance and having >1 to <=1000mum number-average particle diameter. CONSTITUTION:The objective composite spherical substance powder excellent in fluidity is obtained by granulating a composite spherical substance, composed of inorganic substance particles and an organic substance and having >1 to <=1000mum number-average particle diameter, then treating the resultant spherical substance with steam under 0.6-3.5kg/cm<2> saturated steam pressure in a filter of a pressurized filtration method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite spherical powder consisting of inorganic particles and organic materials,
The present invention relates to a method for producing a composite spherical powder comprising inorganic particles and organic materials having improved surface smoothness and excellent fluidity.

[0002]

2. Description of the Related Art In recent years, composite materials between different materials have been actively used as materials having high performance and novel functions, and as a part thereof, a composite spherical material powder composed of inorganic particles and organic materials (hereinafter , Composite spherical powder) has been variously researched and developed and put into practical use.

When magnetic particles are used as the inorganic particles in the composite spherical powder, colored pigment particles are used as the inorganic particles, mainly as a material powder for an electrostatic latent image developer such as a magnetic carrier and a magnetic toner. In this case, it is mainly used as a coloring agent and a matting agent for rubber / plastics, paints, paints and adhesives.

In all of the above-mentioned fields, the most important characteristic among the various properties required for the composite spherical powder is that it has excellent fluidity. The surface of each spherical particle of the body needs to be smooth. Liquidity is a major factor in determining the quality of a product.

Regarding the fluidity of the composite spherical powder,
As a conventional magnetic toner, Japanese Patent Application Laid-Open No. 55-28032 discloses that "a magnetic toner having generally poor fluidity is likely to cause aggregation and solidification, which causes aggregation and solidification on a toner carrier support or in a toner supply tank. However, as described above, there is a demand for a magnetic toner having excellent fluidity.

Further, in Japanese Patent Laid-Open No. 53-94932, "Generally, high-resistance magnetic toner for PPC is used as a fluidity modifier such as silica, carbon black, titanium oxide, zinc stearate ... However, in this method, the fluidity modifier generally does not have magnetic susceptibility, so that the toner image is scattered by the centrifugal force accompanying the rotation of the magnetic roll for development. Then, the image becomes dirty, or the fluidity modifiers become aggregated particles in the process of rotating together with the magnetic brush on the magnetic roll, which causes uneven development. " As described above, a method of dry-mixing an ultrafine powder fluidity modifier to improve the fluidity of the magnetic toner has been proposed, but on the other hand, various drawbacks have been pointed out.

By the way, the organic substances used in the composite powder are roughly classified into thermoplastic resins such as vinyl-based, styrene-based, and acrylic acid-based resins and phenol-based, melamine-based,
There are thermosetting resins such as epoxy resins, and thermoplastic resins that are easy to granulate are generally used as resins for producing composite powder consisting of spherical particles, but durability and impact resistance Thermosetting resins are used as organic substances when excellent properties and heat resistance are required.

Conventionally, as a method of granulating a composite spherical powder, a suspension weight for suspending and polymerizing a polymerizable composition containing a polymerizable monomer, a polymerization initiator and inorganic particles in an aqueous medium is used. Legal (Japanese Patent Publication No. 46-9347, Japanese Patent Publication No. 49-
No. 30702, JP-B-62-28178, JP-A-56-164503), a method in which inorganic particles, a phenolic resin, a curing agent and the like are kneaded and then cooled and ground,
A method in which phenol and formaldehyde are polymerized in the presence of inorganic particles with the aid of a protective colloid (Japanese Patent Laid-Open Publication No. Sho 5)
No. 4-88995), a method of allowing water-insoluble inorganic salts to exist in the polymerization of phenol and formaldehyde in the presence of inorganic particles (JP-A-62-2).
7455), a method of pulverizing a composite of inorganic particles and an epoxy resin and a phenol resin acting as a curing agent (JP-A-58-122705), in the presence of inorganic or organic particles with the aid of an emulsifier. A method of preparing a cured epoxy emulsion and curing it with a water-soluble amine compound curing agent (JP-A-60-1884).
No. 19, etc.) are known.

[0009]

SUMMARY OF THE INVENTION Composite spherical powder having excellent smoothness and spherical particles having a smooth surface and high surface gloss is currently most demanded. In the case of the method, such a composite spherical material powder has not been obtained.

That is, according to the above-mentioned conventional method, even if the shape of the obtained particles is indefinite or the curved surface is increased as compared with the indefinite shape, it cannot be said to be spherical. It was Further, even if spherical particles are obtained, fine particles are attached to the surface thereof, and moreover, there are many irregularities on the surface, and there is no glossy feeling with poor surface smoothness,
As a result, the liquidity was poor.

A technique in a technical field different from that of the present invention is used as a prior art for subjecting an object to be treated with steam for the purpose of washing solids having impurities attached thereto or removing monomers contained in a resin slurry. However, in the field of separating the filtrate raw material into a filter residue and a filtrate, a technique of cleaning and separating with a liquid vapor has been proposed in order to simultaneously increase the purity of the filter residue and the recovery rate of the filtrate. Cage (for example,
JP-A-48-58456) and a technique of steam-treating the vinyl chloride resin slurry when removing the vinyl chloride monomer in the vinyl chloride resin slurry have been proposed (JP-A-56-22305). In the former case, a vacuum filtration type filter is used, and in the latter case, a steam treatment is performed to prevent the monomer from clogging with pores, and at the same time, a special device is used. is necessary.

[0012] Therefore, it is a technical object of the present invention to obtain a composite spherical material powder in which the surface of spherical particles is smooth, the surface has a high glossy feeling, and is excellent in fluidity.

[0013]

The above technical problems can be achieved by the present invention as follows. That is, according to the present invention, the number average particle diameter of the inorganic particles and the organic particles exceeds 1 μm
After granulating the composite spheres having a diameter of 000 μm or less, the spheres are 0.6 to 3.5 kg / in a pressure filtration type filter.
A method for producing a composite spherical powder is characterized in that steam treatment is performed at a saturated vapor pressure of cm ² .

Next, various conditions for carrying out the present invention will be described. The inorganic particles in the present invention are selected from water-insoluble iron oxide, titanium oxide, metal oxides such as zinc oxide, iron hydroxide, metal hydroxides such as aluminum hydroxide and other sulfides, carbides and the like. One kind or two or more kinds can be used.

The inorganic particles in the present invention can be subjected to a lipophilic treatment using a coupling agent such as a silane coupling agent or a titanate coupling agent or a surfactant in advance.

As the organic material in the present invention, a thermoplastic resin such as a vinyl-based resin, a styrene-based resin, an acrylic acid-based resin, or a thermosetting resin such as a phenol-based resin, a melamine-based resin, or an epoxy-based resin can be used.

The composite spherical particles in the present invention are spherical particles having a number average particle size of more than 1 μm and 1000 μm or less.
Further, the content of the inorganic particles is not particularly limited, considering the properties of the inorganic particles and to obtain a composite spherical object capable of sufficiently exhibiting various functions and binding of the inorganic particles by the resin, The content of the inorganic particles is preferably 80 to 99% by weight.

The method for granulating the composite spherical particles in the present invention is, for example, an emulsion polymerization method in which, in the presence of inorganic particles, a monomer and an aqueous solution of a surfactant are mixed and a polymerization initiator is added to carry out polymerization. A suspension polymerization method in which a dispersant such as Poval or a water-insoluble inorganic salt is added to an aqueous or non-aqueous solution and a monomer and a polymerization initiator are added to perform polymerization, and a monomer and a polymerization initiator include a water-soluble polymer. It is possible to use a dispersion polymerization method or the like in which the above is dissolved in an aqueous solution to carry out polymerization, or a method in which inorganic particles are dispersed in a resin solution in which a resin is dissolved in a solvent and then sprayed.

The composite spherical material powder having excellent fluidity according to the present invention has a number average particle diameter of more than 1 μm and 1000 μm or less, and the mixed spherical material is put into a filter of a pressure filtration system, and the powder having a number of 0. It can be obtained by steaming at a saturated vapor pressure in the range of 6 to 3.5 kg / cm ² .

As the filter, a pressure filtration type filter is used. Specifically, a batch type pressure filter such as a pressure filter or a pressure leaf filter, or a cylindrical or disk type continuous pressure filter can be used.

The saturated vapor pressure in the steam treatment must be in the range of 0.6 to 3.5 kg / cm ² . If it is less than 0.6 kg / cm ² , the surface smoothness of the object to be treated is poor and the surface gloss is insufficient, so that a composite spherical powder having excellent fluidity cannot be obtained.
When it exceeds 3.5 kg / cm ² , the sphericity of the object to be treated becomes poor, the surface has many irregularities, and
It is not preferable because the object to be treated may be destroyed.

The composite spheres may be used by suspending the once dried powder in water, but the composite spheres obtained by reacting the inorganic particles and the organic matter in an aqueous medium are dispersed in water. The medium liquid may be used as it is.

[0023]

In the present invention, the reason why the composite spherical powder having excellent fluidity is obtained is that the present inventor does not use a pressure filtration type filter as shown in Examples and Comparative Examples described later. If the saturated vapor pressure is less than 0.6 kg / cm ^{2 or more} than 3.5 kg / cm ² , even if it is simply treated with a vacuum filtration type filter, or even if a pressure filtration type filter is used. In addition, since spherical spherical particles have a smooth surface, high surface glossiness, and a composite spherical powder having excellent fluidity cannot be obtained, use of a pressure filtration type filter and saturation vapor pressure This is considered to be due to the synergistic effect of specifying the range to 0.6 to 3.5 kg / cm ² .

[0024]

The present invention will be described below with reference to Examples and Comparative Examples. The number average particle diameters in the following Examples and Comparative Examples are shown by values measured by a laser diffraction type particle size distribution meter (manufactured by Horiba, Ltd.), and the particle morphology of the composite spherical material powder is scanned. Electron microscope S-800
(Made by Hitachi, Ltd.).

As for fluidity, 50 g of the composite spherical material powder was transferred to a glass funnel (opening 75φ height 75 mm, conical portion inner diameter 6φ).
(30 mm length straight pipe part), the powder drop time (second) when constant vibration was applied was calculated, and the weight of the composite spherical powder particles was divided by the powder drop time to obtain the flow velocity. Shown by value.

The degree of surface smoothness is determined by the scanning electron microscope S-.
800 (manufactured by Hitachi, Ltd.) under the condition that the whole of the composite spherical powder particles can be observed larger,
The presence or absence of surface irregularities or the presence of fine particles was observed and evaluated according to the following criteria. There are no irregularities and there are few fine particles. : A fine particles are present. : B There are many irregularities and many fine particles are present. : C

The degree of surface gloss was observed by observing the surface of the composite spherical powder with a stereoscopic microscope or a metallographic microscope utilizing light reflection, and the glossiness of the surface was evaluated according to the following criteria. Very glossy. : A A little less glossy. : B Almost no gloss. : C

Example 1 400 g of spherical magnetite particles having an average particle size of 0.24 μm were charged in a Henschel mixer and stirred well, and then a titanate coupling agent (Plenact TTS: manufactured by Ajinomoto Co., Inc.)-Hereinafter referred to as "TTS"- 2.0 g was added, the temperature was raised to about 100 ° C., and the mixture was thoroughly mixed and stirred for 30 minutes to obtain spherical magnetite particles coated with TTS.

Separately, in a 1-liter four-necked flask, 40 g of phenol, 60 g of 37% formalin, 400 g of lipophilized magnetite, 10 g of 28% ammonia water,
A number consisting of magnetite particles coated with TTS and a cured phenolic resin, which was heated to 85 ° C. for 40 minutes while stirring 50 g of water at a blade speed of 2 m / sec, and reacted and cured at the same temperature for 180 minutes. An aqueous medium liquid containing a composite sphere having an average particle diameter of 52 μm was prepared.

1 l of an aqueous medium liquid (slurry concentration 50% by weight) containing the above-mentioned composite spheres was put into a pressure filtration type filter equipped with a filter medium, and subsequently the pressure was 2 kg / cm.
Air of ² was blown in to separate the composite spheres and water. Then, instead of air, steam having a saturated vapor pressure of 1 kg / cm ² was blown for 10 minutes, and then air was blown again to cool to room temperature. The surface of each particle of the composite spherical powder obtained here is as shown in the scanning electron micrograph (× 1000) of FIG.
The presence of fine particles is not recognized, the surface is smooth, and
The surface gloss was high and the fluidity was excellent. The evaluation results of the powder are shown in Table 1.

Example 2 γ-having an average particle size of 0.30 μm was placed in a Henschel mixer.
After charging 400 g of Fe ₂ O ₃ particles and stirring well, TT
S2.0 g was added, the temperature was raised to about 100 ° C., and well mixed and stirred for 30 minutes to obtain spherical maghemite particles coated with TTS.

Separately, in a 1-liter four-necked flask, 40 g of phenol, 60 g of 37% formalin, 400 g of maghemite subjected to lipophilic treatment, 10 g of 28% ammonia water,
A number consisting of maghemite particles coated with TTS and cured phenolic resin, which was heated to 85 ° C. in 40 minutes while stirring 40 g of water at a blade peripheral speed of 2 m / sec and reacted and cured at the same temperature for 180 minutes. An aqueous medium liquid containing a composite sphere having an average particle diameter of 46 μm was prepared.

The aqueous medium solution containing the above composite spheres was steamed in the same manner as in Example 1 to obtain composite sphere powder. Table 1 shows the main manufacturing conditions and the evaluation results of the powder at this time.

Example 3 In a 500 ml four-necked flask, 65 ml of water, 5.50 g of sodium hydroxide, 20 g of bisphenol A, 10 g of epichlorohydrin, 2.0 g of phthalic anhydride and a silane coupling agent having a particle surface of 0.5% by weight. KBM602
200 g of magnetite particles (average particle diameter 0.24 μm) coated with (manufactured by Shin-Etsu Chemical Co., Ltd.) were added and stirred. After the temperature was raised to 80 ° C. at a rate of 1.0 to 1.5 ° C./minute, the mixture was reacted and cured at the same temperature for 90 minutes, and the magnetite particles coated with the silane coupling agent and the cured epoxy resin were used. An aqueous medium liquid containing a composite spherical material having a number average particle diameter of 10 μm was prepared.

The aqueous medium solution containing the above composite spheres was steamed in the same manner as in Example 1 to obtain composite sphere powder. Table 1 shows the main manufacturing conditions and the evaluation results of the powder at this time.

Example 4 400 g of spherical magnetite particles having an average particle size of 0.24 μm were charged in a Henschel mixer and stirred well.
2.0 g of TS was added, the temperature was raised to about 100 ° C., and well mixed and stirred for 30 minutes to obtain spherical magnetite particles coated with TTS.

Separately, in a 1-liter four-necked flask, 40 g of phenol, 60 g of 37% formalin, 400 g of lipophilically treated magnetite, 10 g of 28% ammonia water,
A number consisting of magnetite particles coated with TTS and a cured phenolic resin, which was heated to 85 ° C. for 40 minutes while stirring 50 g of water at a blade speed of 2 m / sec, and reacted and cured at the same temperature for 180 minutes. An aqueous medium liquid containing a composite sphere having an average particle diameter of 52 μm was prepared.

1 l of an aqueous medium liquid (slurry concentration 50% by weight) containing the above-mentioned composite spheres was put into a pressure filtration type filter equipped with a filter medium, and subsequently the pressure was 2 kg / cm.
Air of ² was blown in to separate the composite spheres and water. Then, instead of air, water vapor having a saturated vapor pressure of 3 kg / cm ² was blown for 7 minutes, and then air was blown again to cool to room temperature. The surface of each particle of the composite spherical powder obtained here was observed by scanning electron micrograph and the presence of fine particles was not observed, the surface was smooth, and the surface gloss was high, and the fluidity was high. Was excellent. Table 1 shows the main manufacturing conditions and the evaluation results of the powder at this time.

Comparative Example 1 0.5 l of water was added to an aqueous medium solution containing a composite sphere having a number average particle diameter of 52 μm, which was composed of magnetite particles prepared in the same manner as in Example 1 and a cured phenol resin. , The supernatant liquid was removed, and this was then decompressed (5 mm
(Hg or less) at 100 to 150 ° C. to obtain a composite spherical powder. A scanning electron micrograph (× 1000) of the obtained composite spherical material powder is shown in FIG. 2, and the evaluation results are shown in Table 1.

Comparative Examples 2 to 3 Composite spherical powders were obtained in the same manner as in Example 1 except that the saturated vapor pressure was changed variously. Table 1 shows the main manufacturing conditions and the evaluation results of the powder at this time.

[0041]

[Table 1]

[0042]

EFFECTS OF THE INVENTION According to the present invention having the constitution as described above, the presence of fine particles on the surface of the particles is not recognized, the surface is smooth, and the inorganic particles and the organic material having high surface gloss and excellent fluidity are provided. Since it is possible to obtain a composite spherical powder consisting of, powders of electrostatic latent image developers such as magnetic carriers and magnetic toners, coloring agents and glosses for rubber / plastics, paints, paints and adhesives, etc. It can be expected to be used in many fields, such as an eraser.

[Brief description of drawings]

FIG. 1 is a scanning electron micrograph (× 1000) showing the particle structure of the composite spherical material powder obtained in Example 1.

FIG. 2 is a scanning electron micrograph (× 1000) showing the particle structure of the composite spherical material powder obtained in Comparative Example 1.

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Claims (2)

[Claims] 1. After granulating a composite sphere consisting of inorganic particles and organic matter having a number average particle size of more than 1 μm and less than 1000 μm, the sphere is 0.6 to 3.5 kg in a pressure filtration type filter. A method for producing a composite spherical powder comprising inorganic particles and an organic material, which comprises performing steam treatment at a saturated vapor pressure of / cm ² . 2. The method for producing a composite spherical powder comprising inorganic particles and organic material according to claim 1, wherein the organic material is a thermosetting resin.