By Matt Defosse
Published: June 24th, 2010
New grades of halogen-free flame-retardant polyamides (PA) and polybutylene terephthalates (PBT) are available in light natural colors—no red phosphorous here—so that processors of these can process electrical components in all color tones.
Plastics and additives supplier BASF introduced the new grades as part of is pre-K 2010 tradeshow press event this week in Frankenthal, Germany. The new grades will be part of new product lines called Ultramid FRee (polyamide-based) and Ultradur FRee (for the PBT-based compounds). FRee stands for Flame Retardant and Electrical/Electronic (E/E)
At the K show, which begins October 27 in Düsseldorf, Germany, BASF will introduce the first four new grades: Ultramid FRee A3U40 G5, a polyamide (PA) 66-based product that satisfies the requirements of IEC 60335-1, the newest version of the safety standard for household appliances, and Ultramid FRee B3U31 G4, a PA 6 compound tailored specifically to the requirement of circuit breakers.
The PBT line from BASF is being expanded with the addition of Ultradur FRee B4440 G5 and B4450 G5. Both products satisfy the requirements of UL94's flame retardant class V0, with the former earning the highest V0 rating according to UL 94 even at a wall thickness of just 0.4 millimeters. The latter of these is characterized by high tracking resistance, according to BASF, as measured by its Comparative Tracking Index (CTI). Its CTI of 600 makes it possible for component designers to reduce the spacing between contacts and thus shrink the housing and save material.
BASF officials would not give away how they realized improved levels of flame retardance with no halogens and also without reaching for red phosphorus, which is an outstanding halogen-free flame retardant but has a pronounced dark natural color that carries over into the flame retardant component, making it nigh on impossible to mold light-colored parts with this additive. Alternatives to red phosphorus such as organic nitrogen or phosphorus compounds are relatively expensive, but BASF officials said their new compounds combine high performance and relatively low cost.
BASF reckons demand for these new Free-brand plastics has considerable opportunities for growth. In 2009, about 280,000 tons of flame-retardant polyamides and polybutylene terephthalates were sold. Though almost half of the flame-retardant polyamides are halogen-free materials, less than five percent of PBTs are. At an estimated 6-10% per year, the demand growth rate for halogen-free flame-retardant engineering plastics is considerably higher than that of flame-retardant plastics overall, reported BASF. PBT, it says, is probably at the upper end of this range, since the demand for halogen-free products is especially high here.
In related news from the pre-K press conference, John Frijns, Sr. VP plastic additives Europe/EAWA at BASF, in an interview with MPW, said that the integration of Ciba's additives business into BASF went well, with both suppliers' portfolios merging well. Customers—resin suppliers, compounders and also some processors—will benefit from even swifter rates of innovation at the newly merged business, he predicted. The company holds industry-leading positions in light stabilizers, antioxidants and pigments, he said, with solid positions in halogen-free flame retardants and polymer modifiers. He said interest in non-halogenated flame retardants is high enough that the company is focusing further development efforts on these. —Matt Defosse