JPS5917958B2 - Writing surface treatment method for sintered cemented carbide metal compound pen nib - Google Patents

Description

[Detailed Description of the Invention] The present invention aims to eliminate the rough writing feel of a writing instrument pen nib made of a sintered cemented carbide metal compound with high hardness and excellent wear resistance without impeding the wettability with ink. The present invention relates to a writing surface treatment method.

If the ball of a ballpoint pen or the thin tube of a needle pen is made of sintered cemented carbide metal compound powder such as ceramic, tungsten carbide, titanium nitride, or titanium carbide, it is itself very hard, so it cannot be used as a writing instrument nib. It has excellent abrasion resistance, and even when used for a long time, even if the writing line is extremely thin, it shows no change, giving good results.

However, when looking at the surface of such a sintered product under a microscope, it is found that
It can be seen that numerous holes of about 20 μm are irregularly distributed over the entire surface.

If this entire surface were to be made smooth by appropriate means, the wettability with ink would be poor.

On the other hand, if the countless holes mentioned above remain as they are, it will give a rough and unpleasant feeling when writing, which is a serious problem when used in practical use.

The present inventors have discovered that the present inventors can
We have been conducting extensive research to find a relatively simple surface treatment method that can eliminate the unpleasant feeling of roughness when writing.

As a result, we learned that among the countless holes mentioned above, holes of about 1 to 3 microns should be left in place to maintain good wettability with ink; It was found that the large holes mentioned above should be actively filled to avoid giving the writing a rough feel.

It has been found that it is more preferable for this filler to be made of a hard material so as not to deteriorate the above-mentioned characteristics of the writing instrument nib made of a sintered cemented carbide metal compound.

Therefore, in the present invention, in addition to glass and metal, epoxy resin,
By mixing a hard fine powder such as phenol resin whose particle size is adjusted to be in the range of 3 to 5 μm with polyethylene wax having a molecular weight of about 2000, a synthetic resin paste containing the hard fine powder can be formed. The paste is then applied to the writing surface of a sintered cemented carbide metal compound writing nib.

If the hard fine powder is a solvent-soluble epoxy resin, for example, it can be mixed with an organic solvent such as ethyl alcohol to form a synthetic resin paste containing the hard fine powder.

The paste is applied by filling it into the numerous holes on the writing surface, and any excess that adheres to the writing surface is removed later by wiping it off with water, washing with water, or the like.

This removal, coupled with the fact that the particle size of the hard fine powder is 3 to 5 μm, allows for clean removal of holes of approximately 1 to 3 μm that should be left in order to maintain good wettability with ink. On the other hand, since it gives a rough feel, in the case of holes larger than 3 μm that are to be filled, the paste will still remain filled even after removal.

After applying and removing the paste described above, the hard fine powder is appropriately fused.

This method may be performed, for example, by heating immediately or by heating after immersing the material in a hardening agent.

Particularly when the hard fine powder is glass, it is advantageous to heat it to a temperature close to the softening point of the glass so that the filling area can have a smooth glass surface.

The present invention is extremely superior in that it can achieve the intended purpose with such simple processing.

Example 1 A paste obtained by mixing and stirring fine glass powder whose particle size is adjusted to 3 to 5μ and polyethylene wax at a volume ratio of 2:1 was applied to the surface of the pen nib, which is a sintered product made of ceramic (alumina). After coating with a brush and wiping off any excess, the glass was heated for 20 minutes at 600°C, which is close to the softening point of glass.

When the surface of the pen nib obtained in this way was examined under a microscope, it was found that the alumina surface with holes of about 1 to 3 μm remained intact, and the areas with larger holes showed a smooth glass surface, with holes in the surface. It had been crushed.

This pen tip did not have a rough feel when writing, and had good wettability with ink.

Example 2 A paste obtained by mixing and stirring epoxy resin fine powder whose particle size is adjusted to 3μ and ethyl alcohol at a volume ratio of 2:1 was applied with a brush to the surface of the pen nib, which is a sintered product made of tungsten carbide. Then, after wiping off any excess material, it was left at 150°C for 10 minutes to evaporate the solvent, then immersed in a room-temperature curing agent, and then heated at 150°C for 30 minutes to fuse the epoxy resin. .

Similar to Example 1, this pen tip also did not have a rough feel when writing, and had good wettability with the ink.

Claims (1)

[Claims] A synthetic resin paste containing hard fine powder whose particle size can be adjusted to 13 to 5μ is applied to the writing surface of a sintered cemented carbide metal compound nib, and after removing excess adhesion. A method for treating a writing surface of a pen nib made of a sintered cemented carbide metal compound, which comprises suitably fusing the hard fine powder. 2. The method for treating a writing surface of a sintered cemented carbide metal compound pen nib according to claim 1, wherein the synthetic resin paste is a mixture of fine glass powder and polyethylene wax in a volume ratio of 2:1. 3. The method for treating the writing surface of a sintered cemented carbide metal compound pen nib according to claim 1, wherein the synthetic resin paste is a mixture of epoxy resin fine powder and ethyl alcohol in a volume ratio of 2:1.