Polycarbonate price cuts to broaden markets Commonly used metals are under renewed attack following Mobay Chemical's reduction of the price of two large-volume grades of polycarbonate resins. General Electric, the other U.S. producer of polycarbonates, says it will also lower prices on two high-volume grades to match Mobay. It will also lower prices on such premium grades as FDA-approved and high-mold release ones. Mobay's Merlon M-40 and M-50 are the grades affected. Natural and clear-tint resins were reduced 10 cents to a new price of 80 cents a pound. Colored resins were lowered 15 cents to a new price of 85 cents per pound based on a minimum quantity of 15,000 pounds for each color. Prices apply to bulk shipments in fiber drums. The Mobay move signifies a growing realization within the chemical industry that internecine competition between various synthetics is fruitless. That is, the industry agrees more and more that little is gained by replacing one plastic with another, or one synthetic fiber with another. The real market opportunities lie in competing with metals and natural materials. In applications where price per unit volume is the most important design criterion engineers are considering, polycarbonate resins can compete favorably with some metals. For example, Mobay's Merlon at 3.47 cents per cubic inch compares favorably with brass at 16.83 cents, zinc at 4.22 cents, and copper at 10 cents per cubic inch. Polycarbonates now compete more equally with nylon 66 at 3.6 cents per cubic inch and acrylic resins at 1.96 cents per cubic inch. Aluminum at 2.43 cents and magnesium at 1.96 cents per cubic inch continue to enjoy a price advantage, however.
Sales of polycarbonate resins (millions of pounds per year)
1962 1963 1964 1965 1966 1967 1970 Source:
14
6 8 10 14 19 22 35 C & E N estimates
C & E N J U L Y 31, 1967
In lowering prices to increase volume, Mobay is looking to markets now held by metals, such as doorknobs, handles, air conditioning housings, and electric and electronic uses such as power tool housings and conduit boxes. Appliances and lighting fixtures, optical equipment, and sporting goods are other major markets for the tough plastic. The encroachment of plastics isn't going unnoticed by the metals industry. The American Zinc Institute is tripling its budget to $1.2 million in a program to promote the use of die-cast zinc over injection-molded plastics (C&EN, July 24, page 19). Growth of polycarbonates has not matched expectations. In retrospect, the market predictions of the early 1960's seem downright euphoric in the cold light of performance. Introduced in 1960, polycarbonates will reach a production of about 22 million pounds this year, and they may reach 35 million pounds in 1970. Initially, a 1970 market of between 50 and 100 million pounds had been forecast. Combined annual capacity of GE and Mobay is about 25 million pounds. New uses such as window panes for store fronts and schools in neighborhoods where damage to glass from vandals is a serious problem could brighten production figures. Polycarbonate windows will withstand hurled rocks and even shotgun blasts. Foamed polycarbonate products are also expected to help increase sales.
Copper producers widen search for low-grade ore processes The push to find economic processes to recover copper from low-grade ores continues unabated. Clevite Corp., of Cleveland, Ohio, and Powdered Metals Corp., of Phoenix, Ariz., which have recently entered into a joint venture to mine and refine copper, are testing an electrochemical process for extracting the metal from its oxide. In Salt Lake City, Kennecott Copper engineers have been awarded patents on improvements that raise copper yield and cut processing time. These moves follow close on the heels of developments that other companies around the country now have in the works. Both Bagdad Copper and Duval Corp., for example, have installed copper recovery units based on General Mills' LIX-64 liquid ion exchange process (C&EN, April 17, page 62). An electrowinning system that uses a cell of novel design, developed by Continental Copper and Steel Industries, Inc., and the Colorado School of Mines Research Foundation, is now being pilot tested at Golden, Colo.
Kennecott's precipitation plant Record production but new methods sought
Prime cause for the push is that copper continues in short supply and no letup in the situation appears in sight despite record production levels. Output of recoverable copper from U.S. mines has been climbing steadily. Last year it reached an all-time high of more than 1.4 million tons, up 16% from the 1.2 million tons produced in 1962. But copper demand continues to outpace production. The slack has been taken up by release of the metal from the government stockpile and by imports. In 1966, some 665,000 tons of copper were brought into the country, compared with 578,000 tons in 1962. It isn't that the U.S. is short of copper ore. Domestic reserves now stand at nearly 75 million tons, an adjustment upward from the 25 million tons estimated in 1950. Copper sulfide makes up the bulk of the deposits, but copper oxides and sulfates also occur, mainly in the upper layers of the deposits. They stem from the gradual oxidation of the sulfide over millions of years. While copper sulfide continues to be the major source of the metal, because the mineral can be fairly easily separated from attendant gangue by flotation, copper producers are paying greater attention to the oxidized material and are working toward more efficient ways to get copper from it. Clevite and Powdered Metals expect to have commercial-sized electrowinning cells installed and operating within the next two years. Their total output will approach 10 million pounds of copper annually. Powdered Metals has the basic patents on the process. The venture will provide Clevite, a maker of copper products, with an additional source of the metal, alleviating to some extent problems that arise
because of price and availability fluctuations. Kennecott's Utah Copper division is now concentrating on extracting copper from waste d u m p material containing less than 0.4% copper. Modifications in the waste acid-leaching and concentrator steps are boosting recovery efficiency by 20 to 2 5 % . These involve changing the engineering process and making the leaching and precipitation more efficient.
General Motors joins Ford in using electrodeposition This fall, 1968 cars coming off the assembly lines at General Motors' South Gate, Calif., assembly plant will be prime-coated by an electrodeposition process. In addition, a GM facility at Kansas City, Mo., that uses the process to prime-coat auto bodies is being converted from experimental to production use. GM's electrodeposition process, called Elpo, is a further manifestation of industry efforts to comply with legislation such as the Los Angeles County Air Pollution Control District's Rule 66, which went into effect July 1, the San Francisco Bay Area's Rule 3, and other similar legislation in varying stages of preparation. These rules limit the permissible emission of certain organic solvents to the atmosphere. F e w in industry doubt that such legislation will be forthcoming from other states and possibly from the Federal Government as well. All electrodeposition systems in use
Electrodeposition by Ford One answer to Rules 3 and 66
today use water-based paints and emit no organic solvents. Thus, it is more than likely that the technique will spread rapidly as more controls are imposed. GM is not the first auto maker to use electrodeposition as a coating process. Ford Motor Co. has been using it since 1963 for prime-coating Lincoln and Thunderbird auto bodies at its assembly plant in Wixom, Mich. Since then the company has p u t in an electrocoating installation at its Monroe, Mich., assembly plant for coating wheels and possibly other small parts. Several appliance makers now use or are considering using electrodeposition for prime-coating or topcoat enamels. There is one inhibiting factor in growth of the electrodeposition process. It requires the use of large tanks, which take u p lots of floor space within the painting facility. Ford's Wixom installation uses a tank with a paint capacity of 50,000 gallons, for example. GM's South Gate plant has a 30,000-gallon tank. Accommodating the process in existing plants therefore usually requires extensive remodeling, a costly step. Both Ford and GM use the same basic system, although there are some minor differences in detail. Both systems operate with the part to be coated as the anode, and thus use anionic resin species. Both use aminesolubilized polycarboxylic acid derivatives. Finally, both use paint systems with a relatively low solids content (about 1 5 % ) . The choice of resins to be used in the electrocoating process is somewhat dictated by the topcoat to be used. A suitable primer for one topcoat may b e a poor base for another. GM uses acrylic lacquer topcoats and describes trie resins it uses in the Elpo process as "maleonized oil derivatives." The Forbes division of PPG Industries is supplying the water-based primer to GM. Ford uses acrylic enamels for topcoats, b u t does not divulge the composition of its electrocoating primers. It uses outside suppliers for this material now. Ford's Mt. Clemens, Mich., paint division has developed a promising new candidate for electrocoating and may some day produce its own electrocoating resin. Electrocoating is not the only answer to Rule 66-type legislation for the auto industry. The process can presently only be used for prime coats, since the coated prime layer electrically insulates the part from the coating bath. Thus, the acrylics used for topcoats must be applied in the conventional manner. Exempt solvents must be used for the topcoats or the emissions must be incinerated if nonexempt solvents must be used. Growth of the electrocoating process
will not depend solely on concern over pollution, however, as the process has other advantages: • I t is fast, easily automated, and wastes little paint. • It gives a uniform coating, even over sharp corners and edges. • In spite of a relatively high installation cost, direct operating costs are fairly low.
New Van de Graaffs to try to make element 126 An accelerator complex able to produce new elements far heavier than existing transuranium elements is being built by High Voltage Engineering Corp. Theoretically, it will be able to make elements through 184, the Burlington, Mass., firm says. The first experiments, however, will aim at producing element 126. To date, the heaviest element claimed to have been made is 104. The new complex will consist of two Tandem Van de Graaff accelerators. One will be a new 16 million volt (Mv.) unit and the other an existing 12-Mv. model. The new 16-Mv. unit, called T U (for transuranium), will cost the company $4 million. It should be working by 1970. The entire project was conceived by Dr. Robert Van de Graaff, cofounder of High Voltage Engineering who died last January. The system will be able to accelerate ions of all 92 naturally occurring elements to the energies needed for nuclear reactions. Present accelerators cannot attain such energies with ions heavier than argon (element 18) or possibly krypton (element 3 6 ) , High Voltage says. T h e company will invite groups of scientists to use the new accelerator when it is ready. The scientists will apply for grants from funding agencies to cover the $1 million a year operating expenses. High Voltage will also seek a $1 million grant to cover the equipment needed to couple the two accelerators. The company plans eventually to make and sell more TU's. The price will be about $6.5 million. High Voltage has made and sold about 500 accelerators so far, including eight of its 12-Mv. model. Fundamentally, each of the two Tandem Van de Graaff accelerators is a tube with a high voltage midway between its two ends. The two tubes will b e coupled end to end in a straight line with an area of zero potential in between. The voltage in the first accelerator will be positive; that in the second, negative. A negative ion entering the open end of the first tube accelerates toJULY 31, 1967 C&EN
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