Materials (August 01, 2003)

Low-phenol stabilizers improve vinyl for indoor uses

More environmentally friendly vinyl wall and floor coverings are possible using a new line of mixed-metal stabilizers from Crompton. Mark low-phenol series stabilizers eliminate or significantly lower the phenol content of vinyl products, and contribute to better indoor air quality by reducing phenol emissions from vinyl wall and floor coverings.

The new stabilizers are based on either Ba/Zn or Ca/Zn chemistry. One grade, Mark 9306, is designed for clear and lightly filled calendered, molded or extruded compounds.

Crompton Corp. 800-268-5760

Modifier helps TPE imitate leather

Often used to modify thermoplastics for automotive interiors, Sunigum modifiers have found a new use in blends with SEBS thermoplastic elastomers. A Sunigum/SEBS blend is used on the gear lever knob of a new European automobile. In this application the material offers a luxury feel with leather-like softness and matte appearance; excellent weatherability; and good grip and skin fat resistance. In addition, the new material costs less than the previous solution.

Eliokem 330-734-1100

Hybrid thermoset extends properties by crosslinking with thermoplastic

A new high-end thermoset resin is the result of development work by GE Plastics and Bulk Molding Compounds Inc. The material, called Noryl ETX, offers enhanced toughness and strength, low moisture absorption and high dielectric strength. Initial target markets include automotive under-the-hood components and electrical power distribution applications.

The new thermoset has thermoplastic PPO resin characteristics built into its cross-linked backbone, extending material properties beyond regular thermosets such as unsaturated polyesters or epoxy vinyl esters. The PPO component can be varied to fine tune certain properties.

Other Noryl ETX properties are: enhanced ductility, strength and modulus at high temperature, high heat resistance, low shrinkage and inherent FR performance.

GE Polymerland Canada Inc. 888-752-7842

Ultra-soft TPE feels like gel

The ultra-soft injection moldable and extrudable Versaflex CL2003 series of TPEs from GLS is one of the softest injection moldable TPEs in the industry. It has hardness of 30 Shore 00 (the Shore 00 scale can be used to measure materials when their values approach zero Shore A).

With its non-oily, non-tacky feel, the material is suitable for applications requiring a gel-like feel, such as gel inserts for bicycle saddles, shoe sole inserts, furniture arm rests, or handles and grips for personal care items.

According to GLS, very soft TPEs have been around for years, but they traditionally have a yellowish tint, are oily to the touch and are prone to surface defects. The new GLS compound is formulated to achieve water clear color and to minimize surface defects, especially at the gate.

GLS Corp. 815-385-8500

Polycarbonate combines high heat and impact resistance

Bayer’s Makrolon DP1-1848 copolycarbonate is designed for use in applications that are exposed to both high and low temperature extremes.

Compared with bisphenol A polycarbonate, Makrolon DP1-1848 has much higher notched Izod impact strength (50 kJ/m2 even at -60 C), and after heat aging, higher Vicat softening temperature and improved chemical and hot water resistance.

“The outstanding impact strength of Bayer’s Makrolon DP1-1848 combined with high heat resistance is unique,” says Dr. James Mason, technology manager of Makrolon polycarbonate at Bayer Polymers. “This unique balance of properties is achieved by copolymerizing BPA with a proprietary bisphenol rather than using an elastomeric system as impact modifier, which reduces stiffness and heat resistance.”

Potential low-temperature applications include containers for cold storage, ski boot buckles and tops, security glazing, military face shields and goggles, and snowmobile windows. In high-temperature applications, Makrolon DP1-1848 is designed for lamp and lighting components. It provides good dimensional stability and accuracy even at temperatures well above 100 C.

Bayer Polymers 800-668-2554

Metallocene PP suggested for injection-stretch blow molded bottles

Basell has lanched a metallocene polypropylene resin called Metocene that is suitable for liquid packaging via injection-stretch blow molding, and for injection molded labware.

When used for bottles, the material achieves clarity approaching that of PET, and is well positioned for hot-fill and low barrier applications, says Seetha Coleman-Kammula, senior vice-president, Basell North America. Low barrier applications include water, flavored water, dairy beverages and sports drinks.

Bottles blown on a standard ISBM machine show less haze and improved gloss compared with standard polypropylene, and better top load strength.

For injection molding applications, Metocene resins offer dimensional stability, low migration of extractables and the ability to be autoclaved. The materials are FDA and USP Class VI compliant.

Basell Canada 800-387-7870

Weatherable resin has much better color and gloss retention

A new weatherable resin that withstands the punishing effects of UV exposure better than traditional ASAs is now available from GE Plastics. Geloy XTW is said to offer three to five times the color and gloss retention. This extends the perfomance of Geloy for applications such as large thermoforming sheet, building and construction, and automotive.

The material is highly compatible with ABS and PVC as capping stock. Gloss levels can be tailored from 20% to 90%.

The injection molding grades balance impact and flow properties, plus aesthetic appeal.

“You need much more than just additives to get a step-change in weathering, color shift and aesthetic performance over time,” explains Dean Ditmar, global Geloy resin product manager. “Geloy XTW represents a signficant breathrough in ASA weatherability technology.”

Customers are currently validating siding applications for Geloy XTW, including those in blues, earth tones and other darker colors. As well, the resin is expected to be offered for fencing, decking and window applications.

For automotive applications, the material is being suggested for mirror shell housings, appliques and other exterior components.

GE Polymerland Canada Inc. 888-752-7842

Rubber-modified PPS can be molded, extruded

Breakthroughs in alloy research and development have permitted Chevron Phillips Chemical (CPChem) to launch two new grades of rubber-modified polyphenylene sulfide (PPS) alloys that exhibit outstanding flexibility and impact strength without the typical loss in heat resistance.

Xtel XE3035 is designed for injection molding; unfilled Xtel XE3200 is suitable for extrusion processes.

Possible applications range from coating wire and molding under-the-hood components, to lining pipe for hot crude oil extraction. Another possibility is the production of industrial fibres for high-temperature resistant fabrics.

CPChem 877-798-6666

Nanocomposite concentrates anyone can use

PolyOne’s Nanoblend concentrates are designed to replace traditional mineral or glass reinforcements and flame retardant additives in a variety of olefin-based resins, according to David Jarus, PolyOne R&D manager, nanotechnology.

“One reason we launched this product was to take away the hype that surrounds nanocomposite technology,” Jarus said during the recent NPE. “The formulations are readily dispersible and anyone can use the concentrates to develop olefin-based materials for a variety of plastic processes.”

Jarus says the nanocomposite concentrates can deliver higher performance, for example increased modulus, at a lower fill levels than traditional mineral or glass-reinforced additives. The new product family is the result of a strategic alliance announced in January 2003 between PolyOne and Nanocor Inc., the Arlington Heights, IL-based supplier of nanoclays.

PolyOne Corp. 770-243-7000