Sealing 691 and 692 from Umicore Preserve Metal Brightness Indefinitely, Minimize Precious Metal Use

These organic nanotechnology processes have short dwell times

Manufacturers of leather goods, jewelry, hardware and other consumer goods seek long-term protection for precious metal components: a treatment that is invisible, yet prevents oxidation and discoloration over a long service life.

They also seek to limit the consumption of precious metals. With both objectives, the challenge is to do so without detracting from product appearance, feel and overall value perception.

Sealing 691 and 692 offer moderate, and long-term protection, respectively, for yellow and rose gold, silver, copper and tin. Their proprietary organic molecule has a unique affinity for electrodeposition – and unrivaled process flexibility. Both processes have a short dwell time – as little as 4 seconds, compared to competitive products at 30 seconds or longer.

Sealing 691 and 692 permanently preserve metal brightness and luster on high-end jewelry, handles, rivets and other decorative metal components. They also seal thin gold's inherent porosity more effectively than alternatives.

Engineered nanopolymers absorb on the metal surface, crosslinking to form an invisible, undetectable layer. By penetrating the grain structure, it prevents oxidation of the underlying nickel or copper, so when gold is applied, plated parts exhibit high levels of corrosion resistance.

And while a layer of protection a few nanometers thick is what’s most often specified, the use of current allows the building of a layer many molecules thick where desirable.

Global consumer goods manufacturers find that gold alone often fails to meet a high corrosion specification; Sealing 691 and 692 allow products to easily meet these standards.

Other features include:

  • aqueous formula
  • chrome-free
  • RoHS compliant
  • hypoallergenic
  • stain repellent
  • preserves solderability and bonding capacity
  • low contact resistance

Sealing 691 preserves metal's inherent lubricity and leaves technical characteristics unaffected, so it has substantial advantages for electronic applications such as plug connectors. It can be used in rack or barrel equipment, and is particularly well-suited to reel-to-reel equipment.

Sealing 691 and 692 were developed by Umicore Galvanotechnik as improved versions of their popular Antitarnish 616 PLUS. They are available throughout North America exclusively from Uyemura.

Also available: Sealing 691 EL (electrolytic process)

Sealing 691 EL protects technical precious metal surfaces, including electrical contacts. Advantages include reduced coefficient of friction, improved sliding performance for connectors, and long-term protection of the functional layer, even under high mechanical stress. In addition, electrical characteristics, solderability and contact resistance are all unaffected.

Silver surfaces treated with Sealing 691 EL as a final layer produce outstanding results in K2S tests. Sealing 691 EL was developed for electrolytic application in continuous lines and has a very short contact time.

For more details, or to arrange test processing, contact your Uyemura representative.