JPS6223846B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an eyeglass frame using a titanium member made of titanium or a titanium alloy. Titanium or a titanium alloy is lightweight and has excellent corrosion resistance, so it is suitable as a component for eyeglass frames. For soldering these titanium parts to each other or to other metal materials, it is possible to use a brazing material such as silver, silver solder, nickel solder, titanium solder, etc.
External forces such as bending and twisting are applied to the soldered parts of eyeglass frames each time they are put on and taken off, so the soldered parts must have the strength to withstand these external forces. When using silver solder or nickel solder specified by JIS for soldering titanium parts, if the content ratio of copper or nickel contained in these is high, it may react with titanium during soldering heat and form fragile compounds. generate. When the external force is applied to this, the soldering surface tends to separate from the compound located between the titanium member and the brazing filler metal. Furthermore, since the titanium solder is an alloy of titanium, copper, nickel, etc., if the content ratio of these components is high, the above-mentioned fragile compounds are similarly formed, and the soldered surface is likely to peel off due to the above-mentioned external force. Therefore, among silver solder, nickel solder, and titanium solder, those with a high content of copper or nickel are not suitable as brazing materials for titanium members of eyeglass frames. When silver is used as a brazing material, the strength of the soldered joint is sufficient because no fragile compounds are produced. However, the soldered surfaces of titanium parts are activated, and titanium has a very low ionization tendency when it comes to activated titanium and silver. Therefore, if electrolyte such as sweat or seawater adheres, titanium will become silver. Corrosion progresses from the soldered surface between the titanium member and the silver exposed to the outside due to the local battery generated between the two, and the soldered surface eventually peels from there. Therefore, silver soldering cannot withstand use as it is. The present invention provides eyeglass frames having titanium members that maintain sufficient strength of the brazed parts even when external forces such as bending or twisting are applied, or when sweat, seawater, etc. adhere to them, thereby preventing practical problems. The purpose is to obtain something that does not arise. In order to achieve this object, the present invention performs soldering of the titanium members with a brazing material mainly composed of silver, and covers the soldering surface so as not to expose it, thereby avoiding contact with the electrolyte. , suppresses electrolytic corrosion and prevents peeling of the soldered surfaces. The present invention will be explained below with reference to the drawings. FIG. 1 is a sectional view of a test piece for examining the effects of the present invention. This is done by brazing commercially available pure titanium annealed 2 mm wires 1 and 1' using silver 2 as a brazing material by high-frequency heating in an argon gas atmosphere, and then connecting the soldered parts to pure titanium wires 1 and 1'. , and then apply acrylic/urethane resin 3, 3' to a thickness of about 50 μm so that the soldering surface between titanium wires 1, 1' and silver 2 is not exposed at the soldered part.
The coating was applied to a thickness of Using the same method, titanium wires are soldered to BAg3 (silver solder) and GAPASIL9 (titanium solder), which are specified by JIS.
(Ag-9Ga-9Pd) and covered with the above resin. Prepare a total of six titanium wires, two each with the soldering parts coated with the above three types of brazing filler metals (silver, BAg3, GAPASIL9). Furthermore, two titanium wires without coating are prepared, a total of six wires soldered with the three types of brazing materials described above. Then, a cast test was conducted for 16 hours using the method specified in JIS on only one coated set (one set for each of the three types of brazing filler metals) and one uncoated set. For the 12 brazed titanium wires prepared in the above steps,
Distance between supports according to JIS metal material bending test method: 50
A bending test was performed on the brazed joint using a push tool with a radius of 7.5 mm and the bending depth until peeling occurred on the soldered surface was measured. The results are shown in the table below.

[Table] For those not subjected to a surface test, silver soldering is the strongest, followed by GAPASIL9 and BAg3.
The order is as follows. There is no difference in strength between the soldered one and the resin coated one. A cassette test was conducted, and the one that was still soldered suffered the electrolytic corrosion described above, and the one that used BAg3 as a brazing material showed easy peeling. Also, the bending depth was reduced when GAPASIL9 was used as the brazing material. However, with resin-coated products, the electrolytic solution does not come into contact with the soldering surface between the titanium and the brazing metal, so electrolytic corrosion does not occur, and no deterioration in strength is observed, indicating that the effect of the resin coating is significant. . Next, the results of a strength test assuming practical use of eyeglass frames will be explained. FIG. 2 is a perspective view of an eyeglass frame made of a titanium member, and FIG. 3 is a partial view as viewed from arrow A in FIG.
FIG. 4 is a partial sectional view taken along arrow B in FIG. In each figure, the rims 4, 4' have butterfly feet 5, 5',
Bridge 6, and blow tips 7 and 7' (see Figure 4), and blow tips 7 and 7' with end pieces 8 and 8' (fourth
Prepare three hinges 10, 10' for the endpieces 8, 8' and temples 9, 9', respectively (see figure), soldered to the hinges 10, 10' using silver as a brazing material by electrical resistance heating in an argon gas atmosphere. . Then, each of the soldered parts of the first eyeglass frame is coated with acrylic urethane resin in the same manner as described above, and each of the soldered parts of the second eyeglass frame is coated with 10 μm of nickel using electroplating. Leave the frame uncovered. The three eyeglass frames were subjected to the Cath test described above for 16 hours. Then, attach the rim 4 to the butterfly legs 5 and 5' of each eyeglass frame.
As a result of repeated bending tests at 120 degrees centering on the soldered joint with 4', both the resin and nickel coated materials were able to withstand more than 5 bends. Also, when the temple is fully opened, the hinges 10 and 10'
As a result of 5,000 tests in which the distance between the temples 9 and 9' was further increased by 80 mm at a distance of 100 mm from 100 mm, there was no abnormality in the soldered parts of any of the coated items. In the case where the coating was not applied, peeling had already occurred on the soldered surface immediately after the cathode test, and the soldered part could not withstand any of the tests even once, and the soldered part came off. As mentioned above, those with silver soldering as they are cannot withstand use, but those with the soldered parts covered have sufficient strength for practical use. The coating resin should preferably have toughness, and the appropriate coating thickness is 10 to 100 μm. If it is less than that, the corrosion resistance effect will be low, and if it is more than that, there is a risk of cracking, which is not preferable. The entire surface of the eyeglass frame may be coated with the resin. In that case, it is effective to prevent copper contained in nickel silver parts such as hinges and brazing filler metals from corroding and causing patina. In the embodiment, nickel was coated by electroplating, but other metals may be used as long as the ionization tendency is between that of silver and titanium. For example, it may be an alloy of one or more of tin, copper, zinc, etc. Further, the coating method is not limited to electroplating, but may also be chemical plating, vacuum deposition, etc. The appropriate thickness of the metal coating is 5 to 20 μm. The brazing material used in the present invention is mainly composed of silver, and may contain other metals such as copper, nickel, and titanium as long as the brazing strength is within a range that can withstand practical use in eyeglass frames. As described above, according to the present invention, titanium members are brazed with a brazing material mainly composed of silver, and the soldering surface is coated so as not to be exposed, thereby preventing corrosion due to contact with electrolyte. As a result, an eyeglass frame having a titanium member with excellent strength in the soldered portion can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a cross section of a test piece proving the effects of the present invention, Fig. 2 is a perspective view showing an eyeglass frame according to an embodiment of the present invention, Fig. 3 is a partial view taken in the direction of arrow A in Fig. 2, and Fig. 4
The figure is a partial sectional view taken along arrow B in FIG.

Claims (1)

[Scope of Claims] 1. In an eyeglass frame having a titanium member made of titanium or a titanium alloy, the titanium members or the titanium member and another metal member are brazed with a brazing filler metal whose main component is silver. An eyeglass frame characterized in that the brazing surface between the titanium member and the silver is covered with a covering material so as not to be exposed. 2. The eyeglass frame according to claim 1, wherein the covering material is resin. 3. The eyeglass frame according to claim 1, wherein the covering material is a metal whose ionization tendency is intermediate between that of silver and titanium.