Document e1k6pdk412x52NXnzMG5gyjKp

UNIROYAL UNIROYAL, Inc. World Headquarters Middlebury, Connecticut 06749 June 12, 1984 Dr. Carol R.- Stack C.M.A. 2501 M Street, N.W. Washington, D. C. 20037 Dear Dr. Stack: After considerable deliberations I have decided to retire on August 31, so must regretfully resign from the vinyl chloride panel as of that date. I will always cherish the association with the members of this committee over the years. The hectic days of 1974 will stand out in my memory. Please extend my.' best wishes to Maurie Johnson and members of the panel. I'll be interested in the epidemiological update. Sincerely, jm/ cc: J. D. Dee fed Walter D. Harris Corporate Industrial Toxicologist URL 15222 you need Union Camp. With the development of UNIFLEX 312, a polymeric with low temperature flexibility, Union Camp has made significant im provement in plasticizer performance. UNI FLEX 312 is ideal for electrical insulation tapes used outdoors and for other prod ucts with low temperature applications. Polymeric plasticizers are generally well-known for their inherent low volatility, solvent resistance and low migration properties which give vinyl an almost per manent flexibility. These same character istics minimize crazing of polystyrene parts that come in contact with plasticized vinyl. Polymeries also provide greater oil resis tance and less rub-off which are especially important in vinyl upholstery for trucks and buses. To all of these properties, UNIFLEX 312 now offers the added advantage of low temperature flexibility. Our technical service specialists can help you find the right combination of plas ticizer properties to fit your product re quirements. We can also help you attain the most efficient bal ance of costs and properties. For more information about our UNIFLEX 312 and Union [amp other polymeric pias- MBR ticizers, write today. Where the chemistry is fight for success. Chemical Products Division Union Camp Corporation Wayne, N.J. 07470 (201) 628-2340 CIRCLE 42 ON READER SERVICE CARO Plastics Additives Report URL 15224 A history of polyvinyl chloride 1835; Justus von Liebig at the Univer sity of Giessen discovers that reaction of the,:`;oH of.the Dutch chemists" fothyteoe dtahtoride) with alcoholic pot* ash produces a cftkrinecontalnirig gas. Uebig assigns confirmation of the work to Ms student, Victor Regnautt, and lets Regnautt publish as sole author. As a result, Uebig Is forgotten as the discoverer of vinyl chloride. 1872, E. Baumann finds ttiat expo, sure of vinyl chloride to sunlight In a sealed tube produces a white solid ftatreslsts attack by potasshan hy droxide or water and melts- wMh de* composition above 130 C. 1912. Chemlsche Fabric Grlesheim* Electron gives chemist Fritz Klatte the task of finding uses for acetylene, and he develops commercial synthesis of vinyl chloride by addition of hydrogen chloride. 1915. Kiatte finds that organic perox ides initiate polymerization to polyvi nyl chloride. 1926. After years of effort to develop rigid PVC as a replacement far cefcioid, German workers have toiled to build machinery that wHI process the resin and have not overcome the problem of thermal Instability. GrieshelmElectron stops paying the toes that maintain Its patents. Meanwhile in the US., UWon Carbide, locking for uses for the ethylene dichloride by-product of chlorohydrln production, converts it to vinyl chloride with sodium hydroxide. PVC also interests Waldo L. Semon at B. F. Goodrich, who Is looking for an adhesive to bond rubber to metal. Semon observes that boiling PVC in such liquids as tricresyl phosphate or dibutyl phthalate renders it highly elastic, thus discovering plasticizers. In addition to mokflng parts from plasti cized PVC, Semon goes on to coat wire, cloth, and metal parts with solu tions of PVC in ptoirtlcizer or plasti mors ta rafe U.$. production of PVC cized PVC In organic solvents, thereby, 't0gs4bllll6hib..- w Ui inventing plastisol and organdeot pro- cessing techniques. He uses whits lead _ and sodium sweats as heat stabjHzem, 197& Cesare Maltooi, wo^kigi'lbr.''6; group pf European firms at ths jristitut* c* Oncology In Bologna, Haty, ftocto 1928. Union Carbide and Du Pont each that Inhalation of vinyl chloride vapors' find that copolymers of vinyl chloride causes rare angiosarcoma liver can with vinyl acetate have Improved cer in rats. The Manufacturing Chem processiblllty; ists Association Is allowed to see his 1934. Frazier Groff of Union Carbide discovers that afcaline earth soaps sta bilize PVC to heat. 'r-' work, buit only under a confidentiality agreement Forbidden to communicate Moftoni's findings, MCA commissions its own studies of. rats and worker 1936, Union Carbide's PVC hOmopoty- exposures. Late In the year, physician mer plant comes on stream at 4 mU- John L. Creech links deaths of two B. Ikm lb per year. Chemists there find F. Goodrich workers from angfaearcomo that dialkyttin soaps are also heat- to vinyl chloride exposure in Louisville, stabilizers. At B. F. Goodrich, T. L. Ky. Eventually, angiosarcoma deaths Gesham tests thousands of compounds before settling on <fl-2-ethytiexyl phthnl ate as the best plasticizer. 1941. During World War II, PVC is commandeered for military use, with the Navy in particular using large amounts of phosphate-plasticized, fireretardant wire Insulation developed by General Electric. of three dozen people worldwide are tied to vinyl chloride exposure. 1974. Goodrich teds the National Insti tute of Occupational Safety & Health ot thecancer link. The Occupational Safety & Health Administration reduoes permissible vinyl chloride exposure to 5Q ppm from 500 p^rri arid proposes a "zero; detectable limit." Industry 1947. One or more workers now un known hit upon synergistic combina tions of barium, cadmium, calcium, and zinc soaps as heat stabilizers. 1952. Elliott Weinberg at Metal & Ther mit Corp. invents the dibutyltin dimercaptlde with 2-ethyihexyl thfogly coiate as a heat stabilizer far rigid PVC, and at the same time Invents the antimony trlmercaptide tow-cost stabi lizer for pipe, which will be commer cialized 30 years later as tin prices spokesmen say that wtif force them to shut down. OSHA agrees to a phased reduction to, 1 ppm. PVC makers an nounce that they can meet thte and poalter their,plants to So. Later, activ ists tar Industry tar saying f^st that,the OSHA ttrhlt would shut them down and then affnsihQ that they can meat ft. 1980. The National Cancer -fcistitute finds evidence that (fi-2-ethyihexyl phthalate plasticizer causes cancer In rats and mice;* skyrocket. 1962. Stung by inroads of PVC Into 1980. U.3. production of PVC tops 1 pfc>e, metaLplpe makers couicerattack billion lb. with a campaign to.warn public authori ties of toxicity of gases emitted by 1970. Pier Luigi Viola art Regina Elena PVC In fires: - Institute for Cancer Research in Rome finds that exposure to very high levels 1884. A recovering U.S. economy car of vinyl chloride vapor causes ear tu ries PVC use to a record 6.3 billion lb. most used then are benzophenones and benzotriazoles. Also used are such acrylates as 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, which are also called acrylonitriles. According to Joseph Stretanski, who is technical manager for plas tics additives for American Cyan- amid, benzophenones such as 2-hydroxy-4-methoxy- or 2-hydroxy-4octoxybenzophenone usually are used in conjunction with bariumcadmium stabilizers, and such ben zotriazoles as 2-(2-hydroxy-5-ferfoctylphenyl)benzotriazole are used with tins. Benzophenones are yel low and contribute color to a clear vinyl compound. In applications such as it dear vinyl coating for a richly colored flooring tile, the slight yellowing may not matter. Benzotri azoles perform better than benzo phenones and yield clear vinyl prod ucts that are water-white. So some 36 June 18, 1984 CAEN