Explanation of Hazardous Labels
Properties of platinum metal:
Appearance: "platinum" colored suspension
Atomic Number: 78
Atomic Weight: 195.078
The SPI Supplies Platinum Paint has been formulated for those applications
requiring high temperature performance as well as chemical inertness. The
product, when compared to silver, is roughly two orders of magnitude higher in cost, so it should be selected only after the
SPI Supplies Silver Paint
has been tried and found to not work under the conditions of the experiment,
or would be known to not work, just on the basis of first principles.
When applied on a surface, the thin layer, after firing, takes on the
bulk properties of platinum.
There are other applications where silver fails because of its sublimation
characteristics: In a vacuum at temperatures over ~ 550°C/1022°F, the sublimation
rate of silver becomes appreciable, and therefore, can be taken above that
temperature range only for short times, if at all, before running the risk
of vacuum system contamination. Those working in high temperature
superconductor (HTSC) applications encounter this problem presently; there
is the demand for ever higher temperatures, but those using
SPI Silver Paste Plus™
to adhere the wafer to the heater head, must stay below this temperature range.
% Pt solids: 75%
Particle Size of Pt colloid: 0.5 to 5 µm
Resin Content: About half that which is used in the silver paint.
Resistivity: 0.4 ohm/cm (about two or three orders of magnitude higher than silver)
Resin Type: Identical to the silver material (for proprietary reasons, its composition is not disclosed).
Viscosity: Not measured (to minimize material loss) but estimated to be similar to that of the SPI Silver Paint.
The raw ingredient list for the new SPI Platinum Paint is identical to that
of the SPI Silver Paint with the exception of the metal solids. We would
not expect the processing to be different from the silver product however
the sintering of the metal particles would obviously occur at far higher
temperatures than for the silver. And in terms of sublimation of the metal
in a vacuum, this too would be expected to not occur until far higher
temperatures than for silver.
The only real difference between a "paint" and a "paste" is the difference
in platinum solids (the paste being substantially higher in metal content
than the paint). But in the case of commercially available platinum pastes,
they almost all contain a glass frit and are not pure platinum
solids plus suspending medium.
These other products are referred to as "reactive bond" products, that is,
they contain a glass frit which is specifically intended to promote
adhesion to a zirconia substrate. SPI Conductive Platinum Paint contains no
frit. It provides better chemical purity and temperature resistance, but at
the risk of lower adhesion to many surfaces. The SPI-Chem™ platinum paint
contains a much more sophisticated binder system than any other platinum paint or paste of which we are aware.
The properties of platinum, other than its corrosion resistance and high
melting temperature, are not particularly good, and one cannot expect
platinum to have mechanical properties like steel at any temperature. Some
of our existing customers are known to be using this paint on substrates which
are known to pose adhesion problems, such as ceramics and stainless steel,
and they experience adequate adhesion, but this does not
necessarily mean that the paint will have adhesion which is adequate for all
situations when it is applied to other substrates. We can only remind the
reader that the use of this kind of product has to be considered "research"
in nature and in the end, it might be necessary to just "try" some and find
out whether it will or will not work in their particular situation.
We have received messages from prospective customers asking if we could have
made a mistake in the placing of the decimal point in the price. No, there
is no mistake. But the high price is dictated by the fact that a) the
market price per gram of Pt is about 100X that of silver and b) the density
of Pt is about double that of silver, so a given weight of Pt suspension has
the appearance of being about half as much present as for silver.
We have also sometimes been asked by customers whether we "shorted" them on the fill
of the material in the bottle because it just did not look like too much was there
(in comparison to a bottle of SPI Supplies® Brand silver paint). Well,
we will admit that when compared to silver paint, there is not very much in the bottle.
But there is enough to do what one wants to do with it (usually).
There is also a strong tendency for the platinum solids to settle out, probably because
of the density of platinum. However, if some of the thinner is added, it can be resuspended.
However, and again in comparison with silver paint, it will not suspend as easily. A few
quick shakes of the wrist won't do it. But a few minutes in an ultrasonic bath will resuspend it quite easily.
Storage Conditions: Room temperture
Hazardous from the stand point of shipping
Use this authentic thinner for the dilution of the SPI Platinum Paint; it
has the exact composition of the paint but without the metal solids. This
thinner can be used to not only replace evaporated suspending liquid, but
also to dilute the suspension in order to make a fixed amount of this
expensive product "go farther".
Storage conditions: Room temperature
Hazardous from the stand point of shipping