JPS5913076A - Surface treatment of personal ornament such as watchcase - Google Patents

Abstract

PURPOSE:To form a hard transparent protective film on the surface of each of personal ornaments such as a watchcase, by coating the surface with a mixed soln. contg. sodium silicate and silica sol and by drying the soln. CONSTITUTION:An aqueous soln. of sodium silicate contg. 10% Na2O and 30% SiO2 is mixed with silica sol as a colloidal soln. consisting of 30% SiO2 and water as a dispersant in 4-10 ratio of SiO2/Na2O. The surface of each of personal ornaments such as a watchcase, a watchband, a bracelet and a necklace is coated with the mixed soln., and the soln. is dried and solidified at 100-250 deg.C in air or a CO2 atmosphere to form a hard transparent protective film which provides scratch resistance to the surface of each of the personal ornaments.

Description

[Detailed description of the invention] The present invention relates to method C2 for surface treatment of accessories such as watch cases,
In particular, the purpose is to form a scratch-resistant transparent protective film on the surfaces of watch cases, bands, wrist rings, ornaments, etc. to prevent stains.

The surfaces of watch cases and the like are constantly exposed to environments where they are easily soiled, and great care must be taken to maintain the beauty of their appearance. For this reason, there are many proposals to form a protective film on the surface of a watch case, etc. to impart scratch resistance, but all of these methods have drawbacks in terms of transparency, scratch resistance, etc., and are still unsatisfactory. The current situation is that we cannot find anything.

In particular, watch cases made of stainless steel and titanium alloys,
For bands, honed surfaces (fingerprints and oil stains remain as stains that are difficult to remove, significantly lowering the product value and often causing discomfort to the wearer, but as a countermeasure, Teflon coating is applied). However, there are drawbacks such as poor appearance and lack of organic solvent resistance of the coating film itself, and a solution to these problems has been desired.

In view of this, as a result of intensive research, the present inventors succeeded in forming a hard protective film and were able to arrive at the present invention.

The problem is that the mixture of sodium silicate and ricazol
(812o/Na20=4-10) is applied to the surface, dried in air, and a hard transparent protective film is formed on the surface, which is easily solved by the method of the present invention.

To explain in detail the two Cs below, the sodium silicate (Na20.n 5in2) used in the method of the present invention is Na2O10%, 8102, which corresponds to JIB standard No. 3.
It is an aqueous solution consisting of 30% silica sol (NaO,
) is 30% Sin containing water as a dispersion medium and a trace amount of NaO (20.01%) as an impurity.
It is a colloidal solution of

In the present invention, these two are appropriately combined to 810. /Na2O
S j,t OL concentration 3 with a ratio of 4 to 10
A ~30% aqueous solution is applied to the surface of a watch case, etc. by spraying, ultrasonic blasting, or vacuum impregnation, and after drying, it is solidified at 100~250°C in air or in a 002 atmosphere.

The mixed liquid is 810. /Na2O ratio in the range of 4 to 10, a transparent hard glass film can be formed and a uniform transparent film with water resistance, weather resistance, and adhesion can be obtained, but outside this range, it is difficult to form a film. The expected 3- effect will no longer be expected.

Table 1 shows the relationship between the mixing ratio of sodium silicate and silica sol and the formed film.

Table 1 (wt%) ・ -4- The glassy film formed by applying only sodium silicate (water glass) is less effective because it collapses due to moisture such as sweat, and a transparent film cannot be obtained with silica sol alone. It is clear from Table 1 that 5ick2/Na of the present invention,
O ratio is important.

The thickness of the glassy protective film to be formed varies depending on the target member C2, but approximately 0.5 to 10μ is appropriate; as the film thickness increases, the hardness naturally increases, but the transparency deteriorates. Therefore, the film thickness should be determined appropriately depending on the product and intended use.

Next, examples of actual ownership of the present invention will be given.

Example 1 A watch case member made of titanium was prepared from #100 to #300.
After honing with glass beads and air spraying,
Various mixed solutions of sodium silicate and silica sol were ultrasonically sprayed onto the surface and dried at 150° C. for 10 to 30 minutes to form a hard glass film with a thickness of 3 to 4 μm.

Example 2 Watch case member Y made of titanium, 850°C in N2 gas
The surface of the member that had been hardened at 10°C for 20 hours was subjected to the same treatment as in Example 1 to form a hard glass film having a thickness of 1 to 2 μm.

Example 3 A watch back cover made of stainless steel (SU8304) was
The same surface treatment as in Example 1 was carried out to form a hard glass film having a thickness of 1 to 2 μm.

Example 4 A1□O, -Ti on stainless steel (SU8 304) member
O.

(60:40) to a thickness of 30 to 40μ, the watch band surface was impregnated with various solutions of sodium silicate and lycasol under reduced pressure, and dried by heating at 150°C for 10 to 30 minutes to a film thickness of 5. When a hard glass film of ~7 μm was formed, a magnificent color was obtained. Table 2C shows the results of testing various physical properties of the members obtained in each of the above examples.

Table-2 7- Note (1) Components of artificial sweat; Mail (9,9 Jil
/j), Na, 8(o, sy/z), (NH2)
ICo(1,7shij) OH,0H(OH)OOOH
(1,7 #/j), NH40H (0,2 mg/)) immersed at meat temperature for 48 hours (21 Qin is a comparative example.

As can be seen from the above examples, the method of the present invention uses a mixed solution of sodium silicate and silica sol in a molar ratio of 8102/Na, O in a range of 4 to 10, particularly (:5 to 7C) to a surface of an object. A scratch-resistant and transparent glassy film can be obtained by the treatment, and the invention is not limited to Example I and can be applied to a wide range of jewelry to obtain a stain-preventing effect.

Patent 1 axis person Shizuzun time! lt Umeshiki Company Patent Applicant
Techno Kogyo Co., Ltd.

Claims (1)

[Claims] 1. Mixed solution of sodium silicate and nerikasol (810
s+ /Nag O~4~10) on the surface and drying in air to form a hard transparent protective film on the surface.