New Olefinic TPEs for films, fibers, molding.

A new family of propylene-ethylene TP elastomers reportedly features a unique chain microstructure that provides films, fibers, and molded pads with an outstanding combination of clarity and heat-seal performance plus elasticity, softness, processability, and compatibility in blends with other polymers. "Versify" plastomers and elastomers were recently unveiled by Dow Plastics, Midland, Mich. Full commercialization is planned for the second half of 2004. Dow is targeting producers of flexible films and rigid packaging, as well as compounders of TPEs and TPOs.

These resins are the product of new Insight "post-metallocene" catalysts and Dow's solution process. The novel catalysts are said to produce resins different hum those made with Z-N or metallocene catalysts. Versify polymers have narrow molecular-weight distribution but broad composition and crystallinity distribution, which is said to result in improved heat resistance compared with metallocone-based products of comparable olefin content. Broad crystallinity distribution results in a broad melting range. A high melting shoulder is maintained even as the overall crystallinity of the polymer decreases.

Versify polymers also have outstanding acceptance of fillers. Adding 50% alumina trihydrate achieves UL 94V-0 with only a 5% to 10% increase in viscosity vs. more than 90% higher viscosity when ATH is added to other polyolefins.

Twelve initial grades have a density range of 0.858 to 0.888 g/cc, MFRs of 2 to 25, glass-transition temperatures of -15 to -35 C, and melting points of 50 to 135 C. Their flexural moduli range from 1000 to 40,000 psi and Shore A hardnesses are 50 to 75.

Versify resins reportedly produce blown and cost films with excellent clarity and sparkle. Their self-touch feel is dry and non-rubbery, and they have low-noise characteristics. For rigid packaging and consumer durables, they provide low heat-seal initiation temperature and a broad sealing window. The soft-touch feel is expected to generate interest for bottles and medical/hygiene products. Other potential uses are TPEs and TPOs for coated fabrics, artificial leather, grips, and flexible roofing membranes. Tel: [phone] www.dowersify.com