JPS61276902A - Production of surface-treated powder - Google Patents

Abstract

PURPOSE:To carry out simultaneously and efficiently a grinding and surface treatment when surface-treated powder is produced, by grinding a starting material for powder with a grinder using jets of air in the presence of a surface treating agent. CONSTITUTION:When the surface of powder of a pigment, a dye, a polymer, a metal or the like is treated, such a starting material for powder is ground with a grinder in the presence of a surface treating agent so as to carry out simultaneously and efficiently the grinding and the surface treatment of the resulting powder. Silicone oil, a coupling agent, a surfactant, metallic soap, lecithin, fats and oils, paraffin or the like are used as the surface treating agent according to the purpose of the surface treatment. A ball mill, a roller mill or other grinder as well as a grinder using jets of air can be used as the grinder.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of surface-treated powder, and more specifically, in the production process of powder, the powder is pulverized in the presence of a surface treatment agent, and the surface of the powder is treated at the same time as the pulverization. It concerns the method of processing.

Various surface treatments have been carried out to improve the surface properties of powders.

For example, silicone oil, coupling agents, metal soaps, various surfactants, etc. can be coated or adsorbed onto the powder surface to improve dispersibility, make it lipophilic or hydrophilic, improve fluidity, and improve adhesion. , this technology is widely used in various fields.

However, these surface treatments require dispersion, mixing, reaction, separation,
There are many complicated steps such as heating, and there are problems such as deterioration and discoloration during this step.

Furthermore, there were also drawbacks such as granulation and agglomeration due to surface treatment agents.

The present inventors conducted research to develop a surface treatment method that does not involve these complicated steps and does not cause problems such as deterioration, and as a result, in the powder manufacturing process, a surface treatment agent was applied to the surface with high surface activity immediately after crushing. The present invention has been based on the discovery that it is easily adsorbed on this surface when it is attached.

This method eliminates the need for complicated processes like the conventional method.
The desired surface-treated powder can be obtained efficiently.

The powders used in the present invention are commonly used pigments,
It can be applied to most things that are used in powder form, such as extender pigments, dyes, natural and synthetic polymeric substances, and metal powders.

In addition, surface treatment agents include silicone oil, various coupling agents, surfactants, metal soaps, lecithin, oils and fats, waxes, paraffin, fatty acids, starches, celluloses, rosin, polyethylene, polypropylene, higher alcohols, glycols, and acrylics. The type of resin can be used depending on the purpose and application. These are added in advance by rough mixing or spraying.

Pulverizers used in the present invention include ball mills, roller mills, Erofol mills, cryomills, jet mills,
Mainly dry or semi-dry types such as turbo mills, atomizers, lab mills, pin mills, etc. can be used as long as they can be finely pulverized or finely pulverized, but jet stream type ones are particularly preferred.

To explain the present invention with an example, first, a surface treatment agent such as silicone oil is added to coarsely ground inorganic powder such as talc and mixed until uniform.

After that, it is crushed even more finely using a crusher. The surface treatment agent is uniformly adsorbed onto the surface of the powder thus obtained without being contaminated with other substances and before secondary aggregation occurs.

Compared to conventional surface-treated talc obtained by dissolving it in a solvent, adding it, mixing it, and drying it, it has the following advantages:

1. Uniform adhesion of processing agent and high adhesion strength.

2. The process is simple and costs can be reduced.

3. Highly safe as no solvent is used.

4. There is no agglomeration or granulation, resulting in a very smooth feel.

5. There is no heating process, so there are no problems such as unpleasant odors. 6. Grinding capacity is improved.

The powder thus obtained is used in a wide range of fields, including cosmetics, plastics, ink, pigments and fillers for paints, foods, metal materials, pharmaceuticals, electricity, magnetic materials, and ceramics. Compatibility with the base material,
It has effects such as improving dispersibility, fluidity, adhesion, and material strength.

Next, a more detailed explanation will be given with reference to examples.

Example-1 Talli Average particle size 15μ 10Kp silicone oil Shin-Etsu Chemical KF-99100,9 The above composition was mixed well with a Henshil mixer and pulverized with an atomizer manufactured by Fuji Paudal to obtain silicon-treated talc with an average particle size of 10μ. I got it.

The obtained powder was very smooth, had no grains, and had strong hydrophobicity.

Comparative Example-1 Titanium oxide Ishihara Sangyo A-100100,9 Kijiroll ioy silicone oil Shin-Etsu Chemical KF-992F silicone oil was dissolved in Kijiroll, added to 100 g of talc, and mixed for 5 minutes with a household mixer. This was air-dried to completely remove the pheasant roll, and then baked in a hot air dryer at 130°C for 3 hours to obtain silicon-treated titanium.

The obtained powder has good hydrophobicity, but powder agglomeration and
As a result of granulation, there were hard grains in the size of 1 to 3 fins, which gave a bad feel.

Example-2 Tart Average particle size 10μ IKP silicone oil Shin-Etsu Chemical KF-965g The above composition was mixed well with a Henshil mixer, and the mixture was heated using Jet Ohmizer Model 0202 manufactured by Seishin Enterprises (nozzle pressure 6.5Kp/cI).
1) to obtain silicon-treated talc with an average size of 1 μm.

The time required for crushing was 15 minutes. The obtained powder had a very high specific volume and was smooth. This powder also showed strong hydrophobicity.

Comparative Example-2 Talc (average particle size 10μ) IKp was heated using Jet Ohmizer 0202 model manufactured by Seishin Enterprises (nozzle pressure 6.5 K9/
Grinding was carried out using cd). The time required to obtain talc with an average particle size of 1- was approximately 40 minutes.

As is clear from the examples, the powder obtained by the production method of the present invention is extremely superior to conventional surface-treated powder, and the grinding capacity of the grinder is also improved. It has the major characteristics of

Patent applicant: Miyoshi Kasei Ltd. Asada Seifun Co., Ltd.

Claims (2)

[Claims] (1) A method for producing a surface-treated powder, which comprises pulverizing the powder in the presence of a surface treatment agent and treating the surface of the powder at the same time as the pulverization. (2) The method for producing surface-treated powder according to claim 1, wherein the pulverizer is a jet stream type.