Chemicals & additives.

Among the new chemicals and additives introduced at NPE '94 were low-molecular-weight PEs for use as compatibilizers or lubricants, and a family of brominated epoxy oligomer flame retardants.

For use with a variety of foamed thermoplastics is a new group of endothermic blowing/nucleating agents. In colorants, new inorganic pigments and new grades of white pearlescents were among the introductions. Other news includes a compound designed to purge nylon and EVOH barrier resins and a line of CFC-free mold releases.

LOW-MW PEs

The Performance Additives unit of AlliedSignal Inc., Morristown, N.J., introduced Polyace 573 and 804, two value-added extensions to its A-C product line of low-molecular-weight PE polymer additives. Polyace 573 is maleated and contains reactive anhydride groups. Its uses include compatibilizing mixed virgin plastics--primarily PP with nylon for barrier packaging films and for some molding applications.

Polyace 573 is believed to be the first low-molecular-weight maleated PE sold in the U.S. (2000-3000 Mn vs. 8000-10,000 Mn for competitive products), says product manager Greg Borsinger. Use levels vary by application but typically are under 10%. The product lists for around $1.50/lb.

Polyace 804 is a preblend of PE and petroleum wax designed for use as a lubricant in extruded rigid and flexible PVC. It uses a paraffin wax not traditionally employed in PVC and is targeted to replace conventional paraffin wax lubricants, according to Borsinger. He says the key advantage of Polyace 804 over traditional paraffin wax lubricants is its consistent performance during processing. The product is also said to provide improved high-temperature properties, gloss, and anti-blocking characteristics over other paraffin wax types at similar levels (1 phr). It is priced competitively.

BROMINATED FLAME RETARDANTS

Shell Chemical Co., Houston, launched a new family of brominated epoxy oligomer flame retardants designed primarily for thermoplastics, particularly ABS, HIPS, PBT, and PET formulations. Intended as a replacement for octa- and decabro-modiphenyl oxide flame retardants, these products are said to offer a good balance of properties, including good moldability and flow, no plate-out, efficient flammability resistance and thermal stability, good overall mechanical performance, and resistance to discoloration.

Products in this family, sold under the trade name Epikote, range in average molecular weight from 800 to 5000 g/mol and have either epoxide end groups or are end-capped with tribromophenol. Currently, the company is offering five products that have epoxy end groups with bromine content of approx. 50%: Epikote 5050 and DX 5119 are general-purpose grades; DX-5114 is for use with ABS and HIPS; 5051 H is for use with ABS; and 5057 is for PBT and PET. There are four products that are tribromophenol end-capped with bromine content of about 60%: Epikote 5201 and 5201S are both designed for HIPS; 5203 and 5205 are for use in ABS.

NEW BLOWING AGENTS

The Henley Div. of B.I. Chemicals Inc., Montvale, N.J., announced seven new additions to its line of Hydrocerol endothermic blowing/nucleating agents. Typically used at levels of .5 to 2.0 phr, these products have various percentage levels of active content usually in a PE carrier or compatible polymer blend. They are sold as white cylindrical granules. The raw materials of the first three products--HK 40B, CT-1001, CF 60V--meet FDA regulations for food contact.

* HK 40B (40% active content) is designed for foaming PET sheet and is said to yield fine cells and significantly reduce foam weight with APET and PET regrind. Densities of 0.89 g/cc can be achieved with HK 40B, according to the company. It is priced at $4.50-5.50/lb.

* CT-1001 (55% active content) is designed for foaming polyolefins and other thermoplastics that process at low temperatures. It is priced at $3-3.80/lb.

* CF 60V (60% active content) is supplied in an EVA carrier and is designed for fine-celled foaming of thermoplastics in injection molding. It incorporates a mold-release agent for parts that are complicated and difficult to demold. It is priced at $4-6/lb.

* Two products, HP 20P and HP 40P (20% and 40% active content, respectively), are for fine-celled foaming of thermoplastics in both injection molding and extrusion. These are said to be particularly well suited for foaming PP ribbons, films, and sheet. HP 20P is priced at $3.70-4.05/lb, HP 40P at $4.40-5.50/lb.

* LC 40C (40% active content) is for polycarbonate and other thermoplastics that process at high temperatures. It is supplied in a PC-compatible, multifunctional polymer blend and comes as light grey-brown cylindrical granules.

* Finally, Henley's new CT 232 is an enexothermal blowing/nucleating agent--a blend of Hydrocerol endothermics and azodicarbonamide blowing agents for foaming PVC, TPEs, and other thermoplastics that process at low temperatures. The product is targeted toward applications where high gas yield and significant weight reduction are required. Supplied as a yellowish free-flowing powder, it is priced at $2.50-3/lb.

ARRAY OF PIGMENTS

Ferro Corp.'s Color Div., Cleveland, announced the latest additions to its Geode product line of complex inorganic color pigments. Included are new brown pigments with improved heat stability--V-10111, V-10112, V-10113, V-10114, and F-6111-2. Also new is an iron-free mahogany brown pigment, V-12100, for rigid PVC siding, windows, and other profiles. It boasts significantly higher tinting strength for lower use cost.

V-9238 is a new cobalt blue pigment from Ferro that's said to offer improved heat stability plus lightfastness, chemical resistance, and weatherability. A new black pigment, V-302-2, for use in most thermoplastic and thermoset resins is said to offer improved tinting strength.

The Mearl Corp., N.Y.C., introduced four new grades to its Mearlin Magna-Pearl series of white pearlescent luster pigments. Grades 3000 and 3100 are Ti[O.sub.2]-coated mica pigments with an ultra-fine particle size of 2-10 microns. MagnaPearl 3000 is the more economical anatase pigment, whereas the 3100 is a rutile grade said to offer increased luster, whiteness, and coverage.

While also an anatase grade, new MagnaPearl 4000 exhibits a pronounced silvery sparkle effect, complemented by a clean, bright appearance due to its larger particle sizes (15-150 microns). The fourth new grade, MagnaPearl 5000, with particle sizes of 14-95 microns, has a finer, silvery sparkle and is the more economical of the two larger-particle grades.

ReedSpectrum, Holden, Mass., announced the addition of a new line of 12 colors to its ReedLite High Performance Polymers series of color concentrates. The new line is designed specifically for use with DuPont's Zytel HTN nylon resin and was created to complement the material's combination of high-temperature performance, dimensional stability, low creep, and chemical resistance in automotive and electrical/electronics applications. These heavy-metal-free concentrates are said to be comparable to cadmium-based colors in terms of performance and unit cost.

PURGING COMPOUND

The first commercial purging compound from Quantum Chemical Co., Cincinnati, is for effective removal of nylon and EVOH barrier resins from all types of coextrusion equipment. Marketing manager Mike Weber says Plexar 909 is a spin-off of the company's Plexar anhydride-modified LDPE tie resins. In addition to its scrubbing action, Plexar 909 also bonds to nylon and EVOH, effectively encapsulating the resin residue and removing it from equipment components, he explains.

Purging film extruders with the new compound reportedly leads to a significant reduction in film gels. Moreover, Quantum says purge time of Plexar 909 vs. traditional purge methods is considerably reduced. In a blown film coex line with a 2-in. screw, a typical purge would take an hour using about 500 lb of material. Using Plexar 909, purge time is about two-thirds faster and the amount of compound required is one-third less (about 165 lb), according to the company. Optimum results are achieved when the extruder runs at low screw speeds and high temperatures. The product lists at 98[cents]/lb.

CARBON BLACKS COMING

The Special Blacks Div. of Cabot Corp., Billerica, Mass., is close to commercializing several of its developmental carbon blacks for improved conductivity, colorability, and uv stability. Included are grades for wire and cable applications--specifically, the insulation seal in underground cable, which is typically highly carbon-filled (30-40% use levels).

Also near commercialization by Cabot is a new family of super-conductive blacks for automotive exterior applications. These are said to provide higher efficiency at only 10% use levels to ensure retention of polymer properties. Work is also well under way on carbon blacks for pond liners (PE and PP geomembranes) that provide improved uv stability.

CFC-FREE MOLD RELEASES

Sprayon Products, Div. of Sherwin-Williams Co., Solon, Ohio, introduced its 800 Series of mold releases, which do not contain ozone-depleting substances. The new products replace the company's CFC/HCFC-containing 500 Series but are said to deliver similar performance characteristics, such as low to no odor and quick evaporation. Currently available are 811 Dry Film Vydax, 803 Food Grade Silicone, and 814 Paintable Lecithin mold releases.