News in colorants & additives at K'89.

News in Colorants & Additives At K'89

In the field of polymer additives, the K'89 show was a colorful one with the latest news in cadmium-substitute pigments and other colorants, while other exhibitors showed new flame retardants, uv stabilizers, PVC heat stabilizers and modifiers, new-generation nylon tougheners, one-pack "super concentrates," and polyurethane foam additives that help to reduce use of ozone-destroying CFC's.

AWAY FROM CADMIUM

Responding to growing pressure from environmentalists and government agencies over possible health risks associated with the use of cadmium-based pigments, several companies used K'89 to showcase their efforts to move away from a reliance on heavy metals.

For example, Bayer AG (parent of Mobay Corp., Pittsburgh) unveiled two new inorganic pigments, a chrome oxide green and a lightfast yellow, that when combined with organic coloring agents can act as a substitute for cadmium pigments. They contain no binder, suiting them for all plastics, and are also said to be free-flowing, low-dusting and easy to disperse.

Also new is Lightfast Yellow Trial Product PK 5359, a reddish, more saturated type of lightfast yellow 6 R, which is said to offer cost savings, since less of the expensive organic pigment or dyestuff is needed in combination with this pigment. Also, Bayer says it has increased the heat resistance of its yellowish-red Bayferrox 3950 zinc ferrite (formerly Bayferrox Trial Product PK 5086). Now it can be processed at up to 572 F, suiting it to uses in nylon and in ABS, where conventional zinc ferrites change color dramatically, according to Bayer. (CIRCLE 2)

Ciba-Geigy (U.S. offices in Hawthorne, N.Y.) unveiled a heavy-metal-free red pigment designed especially for PVC and polyolefins. Cromophtal DPP Red BP is based on new diketo-pyrrolo-pyrrol (DPP) chemistry. It reportedly has good processing properties as well as high opacity and brilliance, challenging the best cadmium reds. (CIRCLE 3)

Ferro Corp., Cleveland, introduced at the show a series of heavy-metal-free, low-plate-out fluorescent concentrates for use in polyolefin packaging. The new concentrates reportedly permit up to three times as many molding cycles as earlier fluorescent concentrates before mold cleaning is necessary. (CIRCLE 4)

GOING FOR THE GOLD

Both Mearl Corp., N.Y.C., and E. Merck and Co. of W. Germany (parent of EM Industries, Hawthorne, N.Y.) introduced new gold pigments, as well as a few other hues. Mearlin Majestic Gold is a lustrous yellow powder with particle sizes ranging from 6 to 48 microns. It consists of mica platelets coated with titanium dioxide and iron oxide, combining to form a bright gold with a slight reddish cast. (CIRCLE 5)

The other new pigment introduced at K'89 by Mearl, Exterior Mearlin Blue-Green, is the newest of the company's weather-resistant pigments. A free-flowing powder, Mearlin Blue-Green uses a mixture of titanium dioxide and chromium oxide, to give it a blue-green tint, which, company representatives say, was previously only obtainable by mixing. (CIRCLE 6)

Merck displayed four new lustre pigments, including two golds and a pair of silvers. They have an iridescent appearance, are reportedly light-resistant, nonflammable and heat stable up to 1472 F. (CIRCLE 7)

NEW FIRE STOPPERS

New flame retardants shown at K'89 included a fire-barrier filler from ICI Chemicals and Polymers Ltd. of England (parent company of ICI Americas Inc., Wilmington, Del.) and a brominated flame retardant from M&T Chemicals, Inc., Rahway, N.J., which just last month changed its name to Atochem North America Inc. (see PT, Jan. '90, p. 98).

M&T's Adine BBH 44, developed in France, contains 69% bromine and is aimed at engineering plastics. Reportedly it offers thermal stability up to 662 F and provides good uv stability and electrical properties. (CIRCLE 8)

ICI's new Cepree is a white ceramic powder developed by the company's UK-based Soda Ash Products group. Designed for use in a wide range of materials, including glass-reinforced thermosets and thermoplastics, Cepree reportedly creates a barrier in plastics to stop fire penetration at temperatures up to 2012 F. The additive is formulated to melt progressively at temperatures between 662 and 1652 F, encapsulating and protecting the host material from fire. Between 1652 and 2012 F, Cepree forms a strong, integral crystalline barrier within the composite, containing fumes, a company spokesman said. (CIRCLE 9)

ALL-IN-ONE MASTERBATCHES

ICI also showed off its Atmer 7000 "super-concentrates," billed as "one of the most important new products in polymer additives in recent years," because they reportedly enable all the additives required for processing polymers to be loaded in a single step. Developed at ICI's Polymer Additive Business Applications research laboratories in Belgium, Atmer 7000 concentrates are in granular form with 50% active ingredient. (CIRCLE 10)

UV STABILIZERS & ANTIOXIDANTS

Three new light stabilizers were displayed at the K'89 show by Ciba-Geigy. Tinuvin 571 is a liquid benzotriazole for TP urethanes, rigid and plasticized PVC, polycarbonate and nylon. Tinuvin 780 FF is a monomeric, low-molecular-weight stabilizer for PP, HDPE, HIPS, ABS, SAN and ASA. It can also be used in PVC and unsaturated polyester. Tinuvin 840 is a dimeric benzotriazole said to have low volatility and good compatibility with acrylics, PET PBT, polycarbonate, nylons and styrenics. Tinuvin 840 is also designed to prevent deposits on molds, chill rolls or calibrators. Thus, it reportedly can also allow direct two-layer coextrusion of sheets without the use of a neutral third (top) layer to prevent sublimation and/or deposits. (CIRCLE 11)

Ciba-Geigy also introduced a new antioxidant for thermoplastics and elastomers. Called Irganox 3052, it's a nonstaining, nondiscoloring, hindered phenolic that's reportedly stable to heat and light and has extremely low volatility. (CIRCLE 12)

NEW FOR PVC

Two new additives were shown by GE Specialty Chemicals, Parkersburg, W. Va. Blendex 424, is an ABS-based clear impact modifier for transparent PVC packaging, which reportedly also increases printability. Blendex 590 is a patented processing aid that GE says can be used in lower concentrations than conventional acrylic types and gives increased melt strength and better dimensional stability, especially in stretch-blow molding and thermoforming. The MMA/SAN-based processing aid is GE's first processing aid marketed in North America. (CIRCLE 13)

Also new for rigid PVC is a cadmium-free costabilizer from Rhone-Poulenc of France (and Monmouth Junction, N.J.). Rhodiastab 82 is a liquid version and Rhodiastab 83 a solid version of this beta-diketon-based stabilizer. It's aimed at outdoor products requiring uv resistance. (CIRCLE 14)

Elix 3610 from Monsanto Chemical Co., St. Louis, is a new SMA-based modifier for transparent PVC that reportedly provides a level of heat resistance never before considered attainable in the resin. Developed by Monsanto Europe, Brussels, Belgium, Elix 3610 at 20% use level can reportedly raise PVC's heat resistance by 54 [degree F.] Monsanto reportedly has tested injection molded transparent parts at up to 212 F without deformation. The modifier has received food-contact approval in Europe and is awaiting FDA approval. (CIRCLE 17)

TOUGHENER FOR NYLONS

Paraloid EXL 3387 is the first of a new generation of impact modifiers from Rohm and Haas Co., Philadelphia. Designed mainly for use with glass-filled engineering plastics such as nylons 6 and 66, items manufactured with the acrylic-based additive can withstand heat up to 284 F, a company spokesman said. Paraloid EXL 3387 can be processed at up to 572 F. Recommended use levels are 10-15% in glass-filled resins and 20-25% in unfilled materials (see graphs on p. 43). (CIRCLE 18)

URETHANE ADDITIVES CUT CFC 

An additive that enables manufacturing polyurethane foams with densities as low as 1.37 lb/cu ft with little or no auxiliary blowing agent was introduced at K'89 by Th. Goldschmidt AG of W. Germany (offices in Hopewell, Va.). A spokesman said that with the company's new Ortegol 300, the amount of auxiliary blowing agent can be significantly reduced, and the foam can even be blown just with water. The alternative blowing agent contains 50% water, the spokesman said, though he would not reveal the remainder of its formulation. Depending on the type of polyol used, adding 1 pph of Ortegol 300 can reduce the foam's hardness by as much as 30%, Goldschmidt data show. Between 6 and 8 pph of CFC-11 would have to be used to achieve the same result, the company says. (CIRCLE 19)

Goldschmidt also introduced Tego IMR 833, a water-based internal release agent for urethane foams. It eliminates the need for an external mold release and is designed to replace release agents that rely on CFC's or chlorohydrocarbons. (CIRCLE 20)

ROTOMOLDING BIOCIDE 

What's believed to be the first fungus- and bacteria-killing additive specifically for rotomolded plastics was introduced by Morton International's Specialty Chemicals Group (formerly Ventron), Danvers, Mass. Called Vinyzene SB-1 PS, the new antimicrobial additive is a powdered form of Morton's earlier pelletized biocide that goes by the same name. It is designed primarily for use with rotomolded polyethylene, although it is also said to be suitable for polystyrene. (CIRCLE 21)