New additives & RRIM systems at SPI Polyurethanes Expo.

New catalysts, surfactants, blowing agents, mold releases, and colorants made their debuts at the recent SPI Polyurethanes Expo '98 in Dallas. New RRIM PUR elastomers also bowed in.

New surfactants and catalysts

Several new additives for rigid foams were introduced by Air Products and Chemicals, Inc., Allentown, Pa.

* Dabco DC5598 surfactant is a non-hydrolyzable silicone glycol copolymer for PUR and PIR rigid lamination, pour-in-place, and froth foams: It is said to produce fine, uniform cells and low K-factors in foams blown with hydrocarbons, HFC-134a, and HCFC-22. In particular, it reportedly solubilizes hydrocarbons better than other surfactants.

* Dabco DC5599 surfactant is a related product said to have higher efficiency than typical surfactants for PUR and PIR boardstock, as well as improved handling and pumping due to its low freezing point and viscosity. It is particularly suited to HCFC141b/22 co-blown systems.

* Polycat 48 is a proprietary amine trimerization catalyst with balanced blowing and gelling action. It can be used as the sole catalyst in rigid PUR foams. Said to offer improved dimensional stability at lower pack density than other catalysts, Polycat 48 is recommended for pour-in-place foams where K-factor is critical.

* Polycat 18 is an amine co-catalyst that reportedly delays initiation with minimal retardation of cure. It is said to improve flow of PIR boardstock, and high-density microcellular or integral-skin PUR foams. Reduced knit lines in laminated board are claimed.

News in blowing agents

Exxon Chemical Co., Houston, is now offering commercial quantities of its new Exxsol hydrocarbon blowing agents. They consist of high-purity cyclopentane and blends of cyclo- and iso-pentane. Exxon now imports the products from Europe but is building North American cyclopentane capacity to meet anticipated demand as HCFC-141b is phased out. Exxon is targeting foams in roofing, appliances, furniture, and car and airplane interiors.

AlliedSignal Inc., Morristown, N.J., and DuPont Co., Wilmington, Del., have been conducting lab tests with HCFC-124, a gaseous blowing agent for rigid insulation. It has an ODP (ozone-depletion potential) only one-fifth that of HCFC-141b. That could allow its use until 2010, while HCFC-141b will be outlawed Jan. 1, 2003. Both suppliers have applied for EPA approval of its use in construction and appliance foams, where the product could compete against higher-cost HFCs.

Smooth-surface RRIM

Bayer Corp. of Pittsburgh launched Bayflex 180 and 190 elastomeric PUR RRIM systems for vehicle fenders, door skins, and other vertical body panels. They are said to have excellent heat stability, low moisture absorption, low thermal expansion, and high impact resistance. Their excellent paintability reportedly yields DOI values comparable to painted steel. Part density is only 1.25 g/cc at a thickness of 3.0 to 3.5 mm. Bayer says Bayflex 180 with 20-24% filler has been used to mold rocker panels 1.5-2.5 mm thick.