BUSINESS
BABIES ON BOARD
EASTMAN
that Eastman contacted wanted improved dishwasher durability. That was odd, because the glass transition temperature of polycarbonate is 150 °C, well above the The BISPHENOL A controversy gives Eastman’s new temperature in dishwashers. Porter then recalled that polycarbonate polymer an edge in the infant care market locks in residual stresses in the molding process because of its rapid vitrification. EASTMAN CHEMICAL may have hit upon the temperature performance of polyesIn the hot, wet, and alkaline dishwashing the right polymer at the right time. The ters: 2,2,4,4-tetramethyl-1,3-cyclobutaneenvironment, these stresses start to crack. company had been upgrading its polyester diol (TMCD). This monomer, CHDM, and This is why old polycarbonate cups develop copolymers to give them an advantage over DMT form the polymer backbone of Tritan. crazing on the bottom. Tritan, he says, polycarbonate. No sooner had it launched But starting the business wasn’t simply doesn’t have those residual stresses or senTritan, the result of those efforts, when a matter of copolymerizing the monomers sitivity to the dishwashing environment. the controversy over polycarbonate’s raw and marketing the stuff, Porter says. The Frederick L. Colhoun, market developmaterial, bisphenol A (BPA), moved into company had to make sure there was a ment manager for durables at Eastman, consumer revolt. Baby product makers market for the new polymer says the company started scrambled to find replacements, and Eastand a route to make TMCD capturing housewares market man had one. economically. share soon after it launched Tritan is the latest step in the evolution Porter won’t disclose how the polymer toward the end HO OH of Eastman’s specialty polymers business, Eastman makes the monoof 2007. Then, in early 2008, which is focused on polyester copolymers. mer—only that it is made of concerns started mounting Business began more than 30 years ago, raw materials “in Eastman’s over the effects of BPA on 2,2,4,4-Tetramethylwhen it looked to improve upon the properstreams.” In the course of infant and child develop1,3-cyclobutanediol ties of polyethylene terephthalate (PET), researching an upcoming ment. Retailers such as Walwhich is made by polymerizing ethylene glyreport on plastics for baby Mart banned BPA in infant col and either terephthalic acid or dimethyl bottles, Jeffrey S. Plotkin, director of Nexcare products, and manufacturers of baby terephthalate (DMT). tant’s process evaluation and research planbottles sought replacements. PET is fine for bottle applications, but ning program, and Marisabel Dolan, senior According to Nexant, materials being it lacks the toughness necessary for some analyst at the consulting firm Nexant, put substituted for polycarbonate in baby botdurable goods and higher-end packagtogether a possible reaction scheme based tles include Tritan, polyethylene, clarified ing. Thus, the company developed a range on patents Eastman and others have filed. polypropylene, polyethylene naphthalate, of polyesters that Plotkin and Dolan say the probable route and polyethersulfone. Tritan is found in substitute 1,4-cycloto TMCD is a six-step process beginning bottles made by Evenflo, Playtex, and Weil BOTTLED UP Weil hexanedimethanol with propylene. The first three intermeBaby. Plotkin says they have a good, clear Baby has launched (CHDM) for some of diates are isobutyraldehyde, isobutyric appearance and a nice feel. “If you look at a line of bisphenol the ethylene glycol. acid, and isobutyric anhydride, molecules baby bottles made with Tritan, they really A-free bottles “It is one of the few that Eastman already sells as specialty are very attractive,” he says. made of Tritan. monomers we know chemicals. Dimethyl of that toughens ketene, 2,2,4,4-tetraTRITAN COSTS about the same to manuPET,” says David S. methylcyclobutanefacture as polycarbonate, Plotkin estiPorter, a group leader dione, and finally mates. Its priciest component is the novel at Eastman. TMCD, are made in monomer, which costs about $1.30 per lb to Depending on the subsequent steps. make, he figures. However, Tritan is cheapproportion of CHDM As Eastman was er than polyethersulfone, he notes. to ethylene glycol, the working on the Colhoun says Eastman is agnostic on the copolymers have varimonomer technolhealth effects of BPA, but he notes that if ous degrees of chemiogy, it was also samcompanies are looking for alternatives to cal resistance, toughpling the polymer polycarbonate, his company sells one. ness, and stiffness, with customers that Eastman will complete an expansion Porter says. But their use polycarbonate from market development to commercialpoor temperature and styrene acryloscale manufacturing of Tritan later this resistance kept them nitrile resins to make year. But Colhoun is reluctant to acknowlout of dishwasherhousewares such edge the BPA issue as a boon. “It certainly safe housewares. as cutlery, containhelped to have people looking for alternaThere was another ers, and blenders. tive materials,” he says. “I would characterdiol with a long name Porter found it strikize it as a tail wind that aided the adoption that Eastman sciening that all of the of Tritan. But if there was no BPA issue, we tists had known since companies working could still stand on the strengths of the mathe 1960s could boost with polycarbonate terial itself.”—ALEX TULLO WWW.CEN-ONLINE.ORG
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AUGUST 31, 2009
