GE’s New Lexan DMX Polycarbonate Resins Deliver Outstanding Scratch Resistance for Demanding Electronic Applications

Compared to standard PC, GE’s Lexan DMX resins provide improved surface hardness without the need for hard coating.

07/08/06 The keypads, housings, and other wear parts for mobile phones, computers, and digital cameras can take a real beating from constant handling. Although polycarbonate (PC) is a favorite choice for these components, until now it has been necessary to hard-coat the resin to prevent abrasion and maintain a good surface appearance. But secondary hard coating means extra cost, additional processing time, and potential environmental impact. To help solve this challenge, GE Plastics has developed a new family of Lexan* PC resins featuring outstanding scratch resistance. Compared to standard PC, GE’s Lexan DMX resins provide improved surface hardness without the need for hard coating. These materials are excellent candidates for transparent applications such as soft keys, infrared lenses, bezels, and screens.

“To keep their hardworking devices looking great without the added costs and cycle time needed for hard coating, electronics manufacturers wanted a better polycarbonate – and GE delivered,” said Harry Boot, general manager for Lexan resin, GE Plastics Pacific. “Our transparent Lexan DMX resin grades showcase GE’s innovation and responsiveness to customer needs. Compared to standard PC, they provide superior abrasion resistance without a coating. Plus, they are available in a wide range of colors for design creativity.”

Five-Times Higher Pencil Hardness than Standard PC

Featuring a special PC co-polymer, Lexan DMX resins provide significantly improved surface hardness. In independent laboratory tests using the pencil hardness (1 kgf) standard, these materials achieved an H rating compared to a much lower 2B rating for ordinary PC – equivalent to up to five times the hardness of the standard material. The GE resins even surpassed painted acrylonitrile butadiene styrene (ABS), PC/ABS, and other painted resins, which only achieved a mid-range F rating. Further, if the Lexan DMX resin grades are hard-coated with silicone or acrylic, their pencil hardness increases to 3H.

Eliminating the need for secondary coating operations can provide several important benefits to manufacturers:

- Lower costs by avoiding the purchase of coating materials and equipment
- Reduced cycle time by cutting out a secondary processing step and less environmental impact from volatile organic compounds (VOCs) released into the atmosphere from the coating process

GE’s Lexan DMX resins are available globally. They are currently manufactured in Bergen op Zoom, the Netherlands; Mount Vernon, Indiana, the United States; and Singapore. Production will expand to Moka City, Japan, in 2006.