Intercept Shield is clearly the most effective of all those available
today.
Until
now, it has been virtually impossible to keep your valued coins out of harm's
way. Corrosive gases in the environment can be found anywhere, and everywhere.
They are produced not only by some of the most natural things on earth: such as
vegetation, ocean surfaces and wetlands. Even worse, the most common and most
potent of these gases - sulfur and chlorine are two of the major causes of
metal corrosion.
Before Intercept technology was developed, the three
available methods of corrosion protection were volatile corrosion inhibitors
(VCIs), activated charcoal and protective oils. However, they all had
inherent flaws that could, under certain conditions, lead to marring or
corrosion of the metal surfaces they were meant to protect.
The patented Intercept
Shield Technology uses a totally unique approach to protecting metals from
corrosion. Unlike volatile components or oils, it will not coat the metal's
surface. The way Intercept Shield works is by acting as a sacrificial corrosion
agent.
In other
words, when corrosive gases come in contact with the Intercept Shield material,
they are instantly neutralized. The Intercept Shield reacts with the gases in a
permanent and irreversible chemical reaction, thus actually cleaning the
environment around the coin. So ingenious is the technology, that it is
statistically improbable for any corrosive gas, including ammonia and ozone, to
migrate all the way through the Intercept Shield material without being
neutralized by an active corrosion reaction site.
The Proof
Lucent Technologies tested three different coin albums the results
of which, are shown below. This remarkable technology provides 10 years
of corrosion protection for each thousandth of an inch thickness, under
normally encountered corrosive conditions.
Subject: Performance analysis
of the corrosion protection of intercept technology licensed metal substrate
storage product
Intercept Technology is a Lucent Technologies patented and
licensed polymer process. The Technology has been licensed, manufactured,
distributed, and sold by our licensees since 1991. In order to ensure the
highest quality production, and manufacture of Intercept products are maintained,
samples of production materials are regularly retained and tested. These
checks, coupled with periodic inspections and updated improvements in formulations
create a technically advanced product. Periodically, final products are
laboratory tested for static and/or corrosion protection performance.
Coin storage systems are designed to protect copper, silver and their alloys
from tarnishing. These metals are commonplace in the electronic equipment
Lucent Technologies manufactures. Therefore, it is beneficial for Lucent
Technologies Bell Labs to test their performance of such systems so as to
expand our information base in the matter of the atmospheric corrosion protection
of electronic materials. This report describes such a test for corrosion
protection and its results.
Storage systems for coinage have been tested for corrosion protection from
atmospheric trace sulfur gases. Intercept Technology significantly outperformed
non-Intercept Technology systems.
Background
Copper, silver and their alloys have been degraded from atmospheric
gases from the moment they were purified and polished more than 5,000 years
ago. The most abundant corrosive gas is oxygen. Upon exposure to oxygen
copper forms an oxide film of Cu2O, which, is semitransparent, and self
limiting. This oxide grows to approximately 15Å in one hour to an
upper limit of approximately 2 NM at 20° C2. Typical copper degradation
occurs when sulfur and water vapor are deposited on the metal surfaces.
Liquid water, sufficient to form an acidic condensate slurry with sulfur,
occurs at relative humidity levels greater than 60%. This slurry penetrates
and breaks protective oxide interstitial grain boundary bonds. Eventually,
sulfur and copper ions form copper sulfide, which, mix into the oxide, and
form directly on the copper surfaces. In very thin layers an overall darkening
will occur at thicknesses as low as 10 nm3. Typically, experiments used
to mimic these natural occurring processes utilize water and a corrosive
gas. We have chosen this proven method to evaluate product performance.
The gas we wish to use as a catalyst for the test is hydrogen sulfide. It
is abundant in the atmosphere. It has a natural vapor pressure of 292 psi
at STP, is colorless, and it has an affinity for reacting with copper having
a chemical stoichiometry favoring a Cu reaction as does carbonyl sulfide
and three to four times more than So2.
Experimental
Five types of storage boxes were evaluated:
- Intercept
Album, multipage book with clear plastic covered slot and an outer cover
with Intercept Technology throughout the book.
- Sample
X Album, similar to 1, different vendor, no Intercept
- Sample
Y Album, similar to 1, different vendor, no Intercept
- Intercept
Tri Fold, open coin slots: cover folds onto itself. Intercept Technology
protected
- Sample
Z Tri Fold, open coin slots: cover folds onto itself. No Intercept
Technology
The populated
books were placed in the test chamber for a 150ppm hour exposure. Previous
work indicated this exposure is equivalent to average ambient H2S exposure
for 10 years.
Results
