PARYLENE KNOWLEDGE DISCOVERY/HISTORY

By 1947, Michael Mojzesz Szwarc had escaped the ravages of Eastern Europe and was launching an academic career in Physical Chemistry at the University of Manchester, England. His interest in the strength of individual chemical bonds had developed to the point of investigating a class of aliphatic carbon-hydrogen bonds in which the carbon was directly attached to a benzene ring. Experimentally, he heated the simplest compounds having these groups- toluene and the xylenes, ortho-, meta- and para-, as gases to very high temperatures and followed their degradation products and the rates at which they decomposed, both as a function of temperature.

In the para-xylene case only, downstream from the pyrolysis zone in the cooler reaches of the glass equipment, a tan colored deposit formed, which on disassembly of the apparatus could be removed as a thin, filmsy, tube-shaped mass, "the skin of a small snake". He correctly deduced that it had been formed by the polymerization of a specific reaction product of p-xlene, called p-xylyene. Taking his observations one step beyond the immediate requirements of his project (a model investigator), he noted the new polymer's exceptional physical and chemical inertness and wondered whether this "Szwarcite" might have some utility. Michael's snakeskin was the world's first vapor deposited poly (para-xylene) (PPX), which in purer colorless form we know today as Parylene N.

To the young and growing plastics industry of that day, better thermal stability as a cherished quality in prospective new polymers, and Michael's observations inspired vigorous research in many industrial laboratories, including I.C.I. in the U. K. and DuPont, Kellogg and Polaroid in the U.S. At Union Carbide, about five years later, William Franklin Gorman proposed using the very stable dimer of the reactive p-xylylene, di-p-xylylene (DPX), or [2.2] paracyclophane, as the feedstock for an industrial Vapor Deposition Polymerization (VDP) process to produce PPX. He demonstrated that the necessary reactive intermediate could be produced quantitatively in pure form from DPX under milder conditions than those required for its production from p-xylene. A further advantage of the Gorham proposal is the absence of gaseous byproducts, a feature of the production of p-xylylene by all other means presently known.

The trouble with the Gorham proposal was that DPX at the time was only a chemical curiosity. It had been isolated as an impurity in the Szwarc snakeskin, and only tiny amounts were available for its characterization in 1949. Its peculiar strained structure intrigued the academic community, and soon the problem of its synthesis by more conventional means was reported solved in 1951 at the U.C.L.A. Laboratory of Donald Cram (Nobel Laureate, 1988). However, much work remained to be done at Union Carbide before the Gorham proposal could be considered a commercially viable process. This preliminary work culminated in an announcement on February 17, 1965 of the availability of a new polymeric coating system, the Parylenes, consisting of both a new family of polymers plus a unique vacuum method for applying them. Truth be known, Union Carbide developed over 20 types of Parylene, but for numerous reasons, only 3 were deemed commercially viable.

The Commercialization of Parylene

Picture of one of the original pieces of SCS Parylene coating equipment.

In 1971, Nova Tran Corporation was established in Clear Lake, WI. Nova Tran purchased a license agreement from Union Carbide to be one of the world's first Parylene service providers.

Nova Tran's track record of success and experience developing the Parylene industry, drew much interest from Union Carbide. In 1984, Union Carbide purchased Nova Tran, to bring Parylene commercialization in house.

In 1991 Union Carbide transferred all information regarding the development of Parylene and all patents to the newly named Specialty Coating Systems.

In 1994, Cookson Electronics purchased Specialty Coating Systems from Union Carbide.

In 2005, Bunker Hill Capital, L.P. purchased SCS with the intention of supporting greater growth initiatives. Click here to see the announcement.

In 2008, Berwind Corporation, a fifth-generation, family-owned private investment management company, acquired SCS. Berwind’s diversified portfolio is comprised of highly successful manufacturing and service companies which are all leaders in their respective market niche. Click here to see the full news release.