W a n t e d : N e w Uses For N e w Silicones Silicones industry, entering third phase of development, must find novel applications for its new products
Dow Corning, a firm formed for the express purpose of making silicones, h a s just completed a $16 million building program at this plant a t Midland, Mich. This view looks toward the distillation columns of the 300-block section S I L I C O N E S TODAY stand at t h e t h r e s h -
old of a n o t h e r tremendous growth p e riod. This view is enthusiastically h e l d hy the three basic producers in the field—Dow Corning, General E l e c tric's Silicone Products D e p a r t m e n t , and Silicones Division of Union Carbide & Carbon. But to spark this growth effectively, n e w uses—big uses— must be developed. F o r a family of chemicals in c o m mercial production less than 15 years, silicones h a v e grown greatly. In this country alone they a m o u n t to a $ 4 0 million-per-year industry employing nearly 2 5 0 0 people. Because n o n e of t h e three silicones operations is a u t o n o mous, sales or production figures a r e n o t m a d e p u b l i c . This leaves e a c h rival wondering just where t h e other t w o stand. Their individual p i c t u r e s of the industry as a whole show considerable variation in detail. F o r example, their own estimates for total industry sales in 1956 range b e t w e e n $ 3 7 million a n d $50 million. All three are banking on rapid a n d continuing growth. Carbide is n o w on stream with a $14 million plant a t L o n g Reach, \V. Va.; GE's continually growing operation at Waterford, N . Y., is just starting another multimillion dollar expansion; D o w Corning has recently completed a $16 million building p r o g r a m in Midland, Mich. From 5-million p o u n d s in 1 9 5 1 , over-all production capacity has b o o m e d to t h e neighborhood of 30 mil-
Complexity of silicones production is reflected by this m a z e of pipe and tanks used a t t h e finishing stage of their manufacture at Dow Corning
This d o u g h mixer a t D o w Coming's Silastic building the p o l y m e r with filler in t h e production of silicone cones manufacturers—Dow Corning, GE, and Union that silicone r u b b e r is the b i g thing in t h e silicone
lion pounds t o d a y . Even assuming an average price as low as $2.00 a pound, there is evidently considerable unused capacity. All three companies are now trying to improve this situation.
Then at war's end it opened its Waterford plant, and Carbide began pilot plant work in Tonawanda, N. Y. T h e original development of silicones had s p r u n g from t h e need for a heatresistant dielectric resin to use widi glass-fiber tapes in electric motor insulation. But fluids were the first silicone materials produced commercially. Dimethyl silicone polymers could b e made in a wide range of viscosities which changed hardly a t all with temperature. At first, availability restricted these liquids to such uses as damping fluids for instruments and antifoam agents in petroleum oils. Fluids thickened with colloidal silica served as ignition sealers in aircraft engines. By 1944, D o w Corning and GE had both developed silicone rubbers. These methyl silicone elastomers were cheesy in character, but they resisted high temperatures and were strong enough to make gaskets for searchlights and aircraft superchargers. Military needs lessened a t the end of t h e w a r . But t h e value of silicone fluids as mold-release materials in the rubber industry kept the silicones business going during the readjustment period. Gradually lubricants and polishes were commercialized; resins were improved a n d developed into superior high-temperature coatings; a n d silicone elastomers were given better and better physical properties. Within a few vears it became evident that silicones
Birth of the Industry T h e development of polymer chemistry in the 1920's a n d the growth of plastics had led t o some interest in the possibility of hybrid polymers—mating organic polymers (plastics) a n d inorganic polymers (glasses). Corning Glass explored t h i s field systematically during the thirties a n d developed usable hybrids at a b o u t the time it began to market glass fibers. Stimulated b y Corning with the thought of silicone/glass insulation, GE embarked u p o n a long-range study of these materials. Concurrently, a Corning fellowship at Mellon Institute undertook similar work. By 1942, this Corning research had reached a point where commercial production could be planned. Considering the syntheticorganic nature of the operation, Corning joined forces with Dow Chemical in 1943, to organize Dow Corning. A plant was built in Midland, Mich., to supply the a r m e d forces with several silicone products. Meanwhile research was carried on elsewhere. G E developed its direct process for producing organochlorosilanes and w a s making resins and r u b b e r s for the military at its semiworks plant at Schenectady.
at Midland, Mich., mixes rubber. The three siliCarbide—seem to agree field at the present time
i n one form or another could b e used in. almost every industry. As peacetime uses outgrew earlier military needs, silicones entered their second phase. By 1951, Dow Corning w a s getting ready for a major expansion, G E was going full stream at Waterford, and U C C had just entered t h e market. There seems to b e little fear today among the three firms that small operators will move in. T h e engineering is just too tricky, a n d t h e necessary capital investment too great. Technical Service As in many cases where competitors must start out small, developing their own markets, t h e silicones people have h a d tough sledding. Stiff competition h a s made the three companies wary. While respecting one another's technical accomplishments, they often see commercial success based on marketing methods. As with other specialty products where price is secondary, silicones demand customer service. This means expensive technical services. As C . E. Reed, general manager of GE's silicone products department points out, "Technical expenses and costs a r e larger with us than with other parts of the chemical industry." Reed explains: "Applications have to b e discovered first. I n effect, an engineering service is offered—as in the chemical JAN.
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being called a. chemical company; it prefers to be known as a manufacturer of silicone-polymer products, although it is certainly not averse to selling any silicone-containing chemical in volume. While GE's and UCC's silicone operations procure their basic raw materials from outside or integrated corporate sources, D C makes its own electric-furnace silicon. It has recently gone on stream with a German process for production of "silica soot" used as a filler and reinforcing agent in silicone formulations. Properties of Silicones Generally speaking, there are half a dozen major characteristics upon w h i c ' silicones base their value:
This safety glass for jets, based on a special transparent silicone rubber, stays clear and shatterproof at 350° F . , where many interlayers melt industry generally, perhaps, b u t to a higher degree." Industry Philosophy Without a doubt, this search for new applications is expensive. It is also slow. Herein lies an interesting division in philosophy among t h e three producers: D o w Corning historically has developed new uses for its new products; GE follows a similar pattern over a somewhat less extensive range; b u t U C C , besides exploring new areas, often seeks deeper footholds in the industry b y producing improved products for going applications. U C C feels it can gain a major share of an existing market through planning and intensive campaigning. Another big difference shows u p in basic concept. The silicone activities of Carbide and GE are admittedly chemical efforts. Besides producing silicones as such, they develop and promote silane intermediates (C&EN, Oct. 15, 1956, page 5060 and Oct. 24, 1955, page 4512) as well as corollary chemicals—additives, fillers, and other siliconfree materials. In fact, president W. B. Humes of UCC's Silicones Division feels that "most important in the healthy rate of growth of today's market is t h e development of new organosilicon chemicals and monomers." On t h e other hand, D o w Corning—whose only interest is in silicones—shies at 18
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Dielectric properties Thermal stability Inertness Water repellency Defoaming ability Rubbery quality (of elastomers)
The first two "classic" properties are inherent in all silicones—it had been the search for a heat-resistant dielectric that triggered the commercial development of silicones. Silicone coatings allow t h e full advantage of glass-tape insulation to b e realized, since they do not deteriorate at elevated temperatures like conventional electrical varnishes. Class H (silicone) insulation permits design of electric motors to r u n at higher, more efficient temperatures, giving more horsepower per pound and prolonging fife expectancy 10 t o 100 times over class B insulation. Physical —as well as chemical—resistance t o heat is demonstrated by high viscosity index for silicone fluids, pastes, and elastomers. This has led to wide uses at extremes of temperature. The "antisocial" behavior of silicones provides good antiseize properties. This permits formulation of specialty release agents for metal-casting and rubber-forming molds, glassmaking equipment, plywood and plastics machinery, and even bread pans in bakeries. A specific antipathy toward water makes silicones particularly valuable as water repellents. Masonry and concrete can be treated with special emulsions or solutions to prevent deterioration from effects of water, and to minimize efflorescense; leather and textiles can be made "permanently" water resistant. One of the most familiar properties of silicones is the ability to cut foams.
This defoamer u s e has expanded from the first application of silicones in submarine-diosel fuels t o embrace even the food industry. By adding surfaceactive silica to appropriate silicones, products a r e made for treating aqueous as well a s nonaqueous systems. T h e nxbbery character of silicone elastomers has o p e n e d the door to perhaps the "biggest variety of applications. A wide ra.nge of products already exists —from t h e intriguing but almost entirely useless
