New flame-retardant resins out-perform conventional grades

Paul Boughton
Sabic Innovative Plastics is launching three new sustainable additions to its Valox ENH resin series that delivers advanced flame retardance (FR) together with outstanding mechanical and electrical performance to the electrical and electronics (E/E) industry. These innovative materials help customers comply with global environmental regulations, including the European Union (EU) Waste Electrical and Electronic Equipment (WEEE) directive that is now also being applied in Korea and China. The expansion of the Valox ENH resin family is the result of Sabic Innovative Plastics' ongoing focus to provide an ever-broadening portfolio of validated, sustainable materials to customers.
Jos Braat, global product market director for Sabic Innovative Plastics, comments: "Environmental regulations and guidelines regarding acceptable flame-retardant chemicals for the electrical and electronics industry are continuing to tighten. Our dynamic R&D program focused on sustainable solutions continues to yield technological breakthroughs. Our new Valox ENH grades are just the latest deliverables in a strategic effort to evolve our flame-retardant plastics portfolio to be in line with global regulations and voluntary eco-labels that are important to our customers' growth."
Reducing halogen content in flame-retardant polybutylene terepthalate (PBT) is a challenge because substituting a non-brominated, non-chlorinated FR chemistry usually degrades mechanical performance. But Sabic Innovative Plastics' highly experienced scientific and technical team say they have achieved this goal. The three new Valox ENH PBT resin grades, with different glass reinforcement levels, not only utilise non-brominated and non-chlorinated FR technology but are also claimed to provide a better balance of high-performance properties than competitive non-brominated FR PBT resins. They deliver excellent elongation, chemical resistance and impact strength, and offer better electrical and flammability performance than brominated FR grades. Overall, they are said to provide a better balance of properties than other non-brominated FR PBT resins.
The new Valox ENH resin grades are:
* Valox ENH 3500 PBT resin, unfilled
* Valox ENH 4530 PBT resin, 15 per cent glass fibre-reinforced
* Valox ENH 4560 PBT resin, 30 per cent glass fibre-reinforced
These resins meet the UL94 V0 standard at 0.8mm. With a comparative tracking index (CTI) of 500V for Valox ENH 4530 resin and a CTI of 600V for Valox ENH 3500 and Valox ENH 4560 resins, these grades far surpass the CTI performance of standard glass-filled brominated PBT, which is typically around 200V.
These unfilled and glass-filled grades have potential for use in electric cooling fans, relays, connectors, switches and fuser applications in printers. To make applications even more sustainable, Valox ENH resin grades can be enhanced by combining them with other Sabic Innovative Plastics PBT technologies, particularly Valox iQ resins. This iQ technology is referred to as 'upcycled technology' because it incorporates high levels of post-consumer polyethylene terephthalate (PET) bottles into PBT resin through a proprietary chemical process. Upcycling not only diverts waste from landfill but also reduces carbon dioxide (CO2) emissions and energy usage when producing PBT resin. Valox iQ NH 4550 is made from upcycled post-consumer PET and is currently in Sabic innovative Plastics' product portfolio.
The addition of the new materials increases the Valox ENH resin portfolio to five commercial grades that are applicable to many different E/E applications currently made of brominated FR PBT and/or PET. Sabic Innovative Plastics is also planning to launch PBT/PET alloys within the Valox ENH resin family by the end of 2010.
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