Microcrystalline Arkansas Novaculite
•
NOVAKUP®
• BUBBLEKUP®*•
CARBOKUP® • KLAKUP®
• MONYKUP®
•MULTIKUP®
• SILIKUP®
• TIEBRIGHT®
• TITANKUP®
• TRIKUP®
• WOLLASTOKUP®
Surface Modified Inorganics
Below the general heading above, you can see a list of various
trademarks which Malvern Minerals Company owns. This number for one
company gives support to the broad field of surface modified materials.
Today those of us in the plastics and coatings fields know what coupling
agents are and the theory behind their uses. Briefly, most coupling agents
are ambifunctional (ambi meaning on either end in this case). On one end
is a hydrolyzable group which reacts with the functional site on the
inorganic surface. In the case of silane coupling agents, R'Si (OR), are
characterized by dual functionality. R represents an organofunctional
group (such as amino, mercapto, vinyl, epoxy, or methacrylate) and OR
represents a hydrolyzable alkoxy group attached to silicon. R is usually
bonded to the silicon atom by a short alkyl chain. The alkoxy groups
hydrolyze (or otherwise condense) with the inorganic while at the other
end the functional group reacts with the polymeric matrix. Silanes
normally have one organofunctional group and three alkoxy groups.
Titanates, as compared basically with Silanes have one alkoxy group and
three functional groups. The theory behind Titanate technology is very
similar to Silanes.
Malvern began in 1968 to deal with the possibility of altering silica
surfaces to improve market acceptance of a common mineral such as
microcrystalline silica. After conducting many experiments over a period
of several years our commercial plant went on stream in 1973. Our first
patent was granted in this field in 1975 and the second and much broader
patent was issued in February 1979.
The axiom stating that substances made up of continuous three dimensional
atomic lattices must be terminated at a surface gave rise to the
proposition that almost all minerals and crystalline substances could be
subject to surface modification. Because of this we surface-modify
crystalline silicas other than NOVACITE®, diatomaceous earth, fused
silica, clay, calcium carbonate, wollastonite, Process Mineral Fibers,
glass micro balloons, titanium dioxide to name some.
We think it is unnecessary for us to go into diagrams and illustrations
of the chemistry and reactivities of mineral surfaces, coupling agents and
polymers. Information of this nature is covered very thoroughly by such
companies as Dow Corning Corporation, OSI, Kenrich Petrochemicals, Byk
Mallinckrodt and/or Kay Fries.
Converting a typical hydrophilic mineral or inorganic surface into an
organofunctional one is somewhat expensive. Because of the expense
surface-modified materials are used for performance - not economics.
Although economics can many times be determined by performance rather than
price.
Interfacial cross-linking between the inorganic particle and the resin
interface can be expected to generate several potential improvements. To
enumerate, e.g., better physical properties; better mechanical properties;
better electrical insulation properties; and, resistance to loss of
improved properties under prolonged moisture saturation.
Summary: Many of the abundant, inexpensive inorganic materials
(usually naturally occurring minerals) were not acceptable prior to
surface modified art as extender or fillers in polymers because of loss of
properties. This deleterious behavior has been somewhat overcome by
changing the hydrophilic surface Into an organofunctional one. Often, the
organofunctional surface can chemically bond to the resin matrix making
positive contributions rather than negative ones. This all seems quite
exciting and destined to be a hallmark of polymerization progress in the
new millennium.
* Licensed to P. A. Industries, Chattanooga, TN
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Novacite® -
Introduction and Applications
Novacite® Physical & Chemical Data
325 Novacite® ||
1250 Novacite® ||
L-207A Novacite®
About Surface Modified Inorganics
Malvern Trademarked Products
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