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Additives in the environment: a challenge for the nineties.

Additives in the Environment

Major shifts in usage of plastics additives are predicted for the 1990s, and first ammong the driving forces of change is the increased environmental consciousness being forced on suppliers by nervous customers and the public. In the face of a regulatory outlook that is expected to become more severe than ever before, scores of technological developments are emerging from additives suppliers to meet demand for "environmentally safe" plastics. These challenges, plus processors' demands for cost-effective solutions to their problems, added technical difficulties posed by more demmanding applications, growing utilization of higher-temperature engineering polymers and the push to recycle, appear certain to significantly alter the repertoire of additives and where they're used.

After almost a decade of sluggish R&D activity, industry experts say innovation in the additives business is once again on the upswing. One example of the regained momentum can be found in the product line of Ampacet Corp., Tarrytown, N.Y. Of the 1400 different color and additive concentrates produced by the company inn 1989, almost 400 were new products. A year before,, Ampacet added approximately 250 new offerings to its line.

"I really think it's faster paced thann I've ever seen it," says Kenneth Bergman, director of marketing for Synthetic Products Co., Cleveland. "Ten years ago, I would've sworn we'd never replace cadmium in vinyl stabilizers. But now we have systems that are as effective as cadmium."

The replacement of cadmium and several other heavy metlas in pigments and vinyl stabilizers is just one factor responsible for the renewed emphasis on product development. Materials suppliers such as Quantum Chemical Corp.'s USI Div. in Cincinnati; Mobay Corp.'s Plastics and Rubber Div., Pittsburgh; and GE Plastics, Pittsfield, Mass., have announced their intentions to become cadmium-free this year (see PT, June '90, p. 138). Dozens of others have not yet sworn off heavy metals but are moving to either curtail their use or develop alternatives. Meanwhile, the frequenncy with which stabilizer manufacturers develop alternatives to cadmium is expected to increase dramatically.

Environmental issues are expected to affect other additive types as well. Flame retardannts are expected to move away from the use of halogens such as decobromodiphenyl oxide; and use of the workhorse phthalate plasticizer DOP (or DEHP), long suspected or promoting liver cancer, may be reduced as researchers seek suitable alternatives.

"The difference between now and 10 years ago is the number of regulations and restrictions you must meet," says James L. Dever, director of technology and commercial development for the Chemicals Group of Ferro Corp., Bedford, Ohio. Federal and state law-makers driven by public outcry to protect the environment are stepping up efforts to ennact legislation that additives suppliers feel will force them to alter many of their products' chemistries. The result of this mounting pressure, suppliers and processors agree, will be the development of many products that are not "new" inn the strictest definnition of the word, but fresh ideas based on existing products. Most industry experts say the trennd for the coming decade won't be the development of never-before-made molecules but new commbinations of existing ingredients, combining the best properties of several additives into one superior product.

Many of the new additives, suppliers say, will have to give better perofrmance than anything on the market today, since all agree the trend is toward plastic parts with much longer lives than ever before. Added to that is the rapidly increasing pace of America's race to recycle. The additives of the '90s, industry insiders say, will have to be better thann ever since they will be expected to perform more than once.

"What I envision as the value of a platic product will be based on its value on the second or third use," says William C. Jenkins, marketing manager for GE Specialty Chemicals, Parkersburg, W. Va. "The more value you get out of that second use, the more you can spend to create the product."

Not only will additives of the future be geared toward reuse, some suppliers say, but so will the packages they come in. Suppliers, such as Rohm & Haas Co., Philadelphia, and Synthetic Products, are developing "super bags" made of PVC or polyethylene that, once emptied, can be tossed right into the regrind hopper in the production stream.


Suppliers say that aside from meeting ever-tigtening environmental restrictions, perhaps the factor most responsible for the development of new additives will be developing closer working relationships with customers to better satisfy their needs. "The winners in the additives business in the next 10 years will be those who understand their customers' needs and meet those needs," says Charles Gruber, Rohm & Haas market manager for plastics additives. "You have to get all the people in the chain involved so they all understand what is needed to bring that product to market."

To meet those goals, many suppliers and processors have formed joint research and quality-control programs to share ideas and information--a trend, most say, that will contribute through the '90s and into the 21st century.

The result of this cooperation, suppliers and processors agree, is new products being introduced faster, additives of improved quality, and additives that perform the functions most wanted by customers. "Customers want lower costs," says David B. Fultz, president of the Plastics Additives Div. of Atochem North America, Philadelphia. "Their investment in new processing equipment is very high. If they can get 20% more product from a machine, great. New additives can do this for them."

As part of this cooperative spirit, an increasing number of suppliers are including statistical process and quality control (SPC/SQC) documentation with shipments. While some companies are only sending the quality certificates when asked by customers to do so, others hope to have total certification on all their products as early as next year. "We measure and q-c everything anyway," says Eric Reger, Ampacet Corp.'s technical service manager. "All we'll have to do now is document it."

PLASTICS TECHNOLOGY asked a broad cross-section of additives users and suppliers to help identify most likely, and/or most desirable, directions for future additives developments. While not everyone agrees on the direction the future will take, most are in concert that the 1990s will be a decade of change for plastics additives.


The biggest challenge facing plastics colorants in the '90s, suppliers and processors agree, is replacing the heavy metals everyone has come to rely on to provide the vivid hues so popular in today's marketplace. "We'd like to see less heavy metals; specifically, cadmium- and lead-based pigments." says William Alexander, a chemist with Bata Shoe Co. Inc., Belcamp, Md. "Increasing regulations on the federal level are making it harder to use these. Bata Shoe Co.'s plight is shared by processors and suppliers alike. All would like to see heavy metals out of the marketplace but few have a clear idea what will replace them. "To say you simply want to eliminate heavy metals is just not that easy," Ampacet's Reger told an audience of more than 300 at the recent SPE ANTEC in Dallas. "Comparable substitutes are just not available. The processor must be willing to compromise on color and performance and even cost."

Suppliers admit many of the existing heavy-metal substitutes--mixed-metal oxides, and various organics--are improving but still don't provide all the bright colors, opacity, weatherability and heat stability to which processors have become accustomed. There's hope, however. "We've got technology that looks really good now," says Jay Lindstrom, project manager for mechanical and packaging markets at the Reed Plastics R&D center in Albion, Mich. Reed is developing thermoplastic color concentrates without heavy metals, which "can replace them with little or no loss of properties," Lindstrom says.

Still, most sources say the negatives associated with heavy-metal replacements, coupled with evidence that some organics may not be much better for the environment than heavy metals, have led many to question where the future lies. Take the case of diarylide yellow organic pigments, one of the prime candidates for replacing heavy metals. Tests done by Ampacet on diarylide yellows show that at about 464 F, the pigments release dicholorobenzidine, a known carcinogen. In late April, three major colorant manufacturers--the Pigments Div. of Ciba-Geigy Corp., Hawthrone, N.Y.; Hoechst Celanese Corp., Chatham, N.J.; and ICI Americas, Wilmington, Del., warned their customers to avoid processing diarylide pigments at temperatures exceeding 392 F. "Where's it all going to end?" asks an exasperated Reger. "Will we revert to a black-and-white world?"

Or worse, suggests Benjamin Berkman, v.p. of PMS Consolidated, Coral Springs, Fla. "We could well end up seeing packagers choose to not color but instead opting for making clear containers with printed labels."

In order to address this growing concern, colorant manufacturers have adopted two distinct philosophies for the '90s. One camp, including Ampacet, Ferro, Quantum and dozens of other concentrate suppliers, have begun their quest to eliminate heavy metals by removing cadmium from their product lines. These same companies, along with others that have not yet phased out cadmium but hope to drastically curtail its use, are now exploring the possibilities of eliminating the use of other heavy metals. Many say they feel lead chromates may be the next to go.

On the other side are companies that continue to believe heavy metals such as cadmium are getting a bum rap and don't really pose the hazards claimed by environmentalists and health officials. These companies, including the Pigments and Additives Div. of Engelhard Corp., Menlo Park, N.J., have developed lines of low-dusting, heavy metal-containing pigments which reportedly give the same superior performance as earlier heavy-metal pigments without presenting what many perceive to be health risks.

"We believe there is a base market for lead chromate and cadmium pigments," says Carleton Johnson, business manager of Engelhard's color group. "Of course their use will decline, but we think there are ways we can approach the problem so they will not have to be completely banned."

Johnson and Subhash Lele, Engelhard's color group technical service manager, are among a handful of industry experts who feel the furor over exposure to cadmium and lead chromate pigments is being blown out of proportion. They dispute findings that the ash from waste incinerators that burn plastics colored with heavy-metal pigments is laden with toxics that can leach from landfills into groundwater supplies, increasing the public's chances of contracting cancer. (Cadmium pigments, in fact, are made by calcining at temperatures around 1200 F, which renders them almost totally insoluble.) They fear this misinformation may result in a ban on the use of the heavy metals.

As an alternative to conventional lead chromates, Engelhard, through its Harshaw Div., has introduced silica-encapsulated lead chromate pigments, which have proven to significantly lower the level of acid-soluble metals released upon burning or burial in a landfill. Though certainly not a new idea, (the technology was developed and patented more than 10 years ago) more than one supplier of silica-encapsulated lead chromates is news. Possession of the silica-encapsulated lead chromate patent (first by Du Pont, then heubach Inc., Newark, N.J. and finally Cookson Pigments, Newark, N.J.) has meant only one producer of the pigments. But now, that patent is about to expire, opening the door for other producers to enter the market.


Like colorants and pigments, reduced dependence on heavy metals, especially cadmium, will play a significant role in the future of PVC heat stabilizers. Processors are expressing considerable interest in switching from lead- and cadmium-containing stabilizers provided they can find alternatives with similar cost/performance. Barium/zinc substitutes for Ba/Cd stabilizers have been around for many years, but have so far elicited few takers. Lead stabilizers for wire and cable, however, have remained unchallenged by any credible alternative.

"One very big challenge to the industry will be the replacement of lead-containing stabilizers for wire and cable," says Victor R. Struber, director of marketing for Argus Div. of Witco Corp., N.Y.C. "Lead has been an outstanding insulator and has provided great electrical properties. There's been nothing found yet that provides properties that are as good."

One alternative to cadmium and lead has been tin. But even that seemingly innocuous metal, some feel, may find itself under the environmental gun in the coming years. "I think it will eventually become classified as a heavy metal," says Edward M. Freshman, Ferro's plastics additives business manager. "Some tin stabilizers in many countries are viewed as toxic." Ferro is developing a non-tin alternative that reportedly will provide equal cost/performance; its composition is still secret, but it's expected to be introduced later this year (PT, June '90, p. 14).

Others say Freshman's prediction of tin's demise may be premature. "If there are any stabilizers that have a history of never presenting health problems, certainly tin-based stabilizers are the ones," argues Witco's Struber.

While there's disagreement on the fate of tin, there's little argument over cadmium's future. "Cadmium is going to have a very rough time," Struber concedes, reiterating the concerns expressed by suppliers and processors across the country. A pending OSHA standard proposed in February would reduce exposure to cadmium in the workplace by 95-99%, going from the current 200 micrograms/cu meter to between 1 and 5 micrograms/cu meter (PT, March '90, p. 113). "This, plus the EPA, plus the state legislatures all adds up to an awful lot of pressure on cadmium and gives us direction on which way we have to go," Struber says.

Just this year, several suppliers, including Witco, Synthetic Products and Akzo Chemicals Inc., New Brunswick, N.J., introduced cadmium-free stabilizers--some of them involving allegedly brand-new chemistry--that they claim provide equal or better performance than their heavy-metal-containing counterparts (PT, March '90, p. 92).

"What we perceive is cadmium being phased out and barium/zinc taking that market over," says SynPro's Bergman. "When that will be no one can really tell, but I'd say within five years there will be a significant change in the cadmium market."

The '90s could see significant reduction in the use of halogen-based flame retardants, some experts say. Such a trend could spell doom for the world's second most popular flame retardant, decobromodiphenyl oxide, industry insiders feel. "We've already seen manufacturers in Germany, Holland, Switzerland, Denmark and most of Scandinavia say they will not use it any longer," says Frank A. Carragher, group v.p. of chemicals for Ferro Corp. "There's nothing to make me think the same thing won't happen over here. Therefore, we feel the non-halogen issue will be very important by the late '90s."

Right now though, it doesn't seem to be a high priority for processors, Unsatisfied with the current crop of non-halogen flame retardants because of poor performance and the extremely high loadings required to provide adequate results in most polymers, processors are reluctantly reverting to the use of halogenated flame retardants until the quality of the alternatives improves.

"None of the flame retardant alternatives meet our standards," says Kenneth L. Brenis, purchasing manager for the Dekoron Div. of Furon Co., Aurora, Ohio. "We want them to be able to pass a variety of burn and smoke-chamber tests, not just have a UL 94V-0 rating."

For others, the high loadings required when using non-halogens are troublesome. "Compared on an equal-weight basis with decabrom flame retardants, these alternatives do not work," says Thomas R. Pfeiffer, technical director of Ampacet Corp.'s R&D center in Terre Haute, Ind. "You need to use so much--say, up to 60% by weight of the total--that you cannot maintain the material's physical properties."

Pfeiffer says Ampacet is investigating the use of new alumina trihydrate-based flame retardants being developed by Solem Industries Div. of J.M. Huber Corp., Norcross, Ga., and Great Lakes Minerals Co., Royal Oak, Mich.

While suppliers like Solem and Great Lakes are working on more effective non-halogenated flame retardants, industry insiders say this is just one of the many problems with which they will have to grapple in the coming decade. "A key issue, as we see it," says John Avento, business development director for Atochem North America's Plastics Additives Div., "is trying to arrive at a situation where all the ingredients in a polymer are non-toxic during smoke generation."

His feelings are echoed by others who agree that reducing the amount of toxic gases given off when plastic burns and limiting the amount of smoke during a fire are the two key issues that flame retardant suppliers must address. "While toxics may be the topic of the late '90s, smoke evolution will be the topic of the early '90s," predicts Jacinthe L. Levesque, specialty magnesium chemicals product manager for the Ventron Specialty Chemicals Group of Morton International, Danvers, Mass. Magnesium carbonate and hydroxide have been the subjects of considerable research in the last few years and appear to be among the most promising new tools for achieving smoke reductions. (New versions of these inorganics were recently introduced by Morton--see New Products section.)

Phosphorus-based flame retardants are one major alternative to halogens; Akzo Chemicals in Chicago is one firm that's developing phosphorus-type non-halogen FR agents for PP, nylon and other engineering resins. Other more exotic compounds are also being explored. Inorganic tin chemicals were proposed recently by Alcan Chemicals, Cleveland, as an alternative to antimony oxide as a smoke-suppressant synergist for halogens (PT, April '89, p. 63). The National Institute of Standards and Technology (NIST) in Gaithersburg, Md., reports that copper or cupric oxide can reduce toxic-gas emission from burning urethane foam (PT, Dec. '89, p. 19). GE Silicones, Waterford, N.Y. has developed a successful non-halogenated flame retardant for polyolefins by combining magnesium stearate, ATH and EVA with its SFR-100 silicone resin (PT, March '90, p. 75). And ICI Americas Inc., Wilmington, Del., is even offering a powdered ceramic, called Cepree, which melts and forms a fire barrier similar to a char layer (PT, Feb. '90, p. 45).

Two trends that many see as important factors in the future are: 1) intumescent additives that foam up into a coating of inert char, which insulates the remaining polymer from heat and flame; and 2) reactive flame retardants, which bond chemically with the matrix polymer to prevent leaching, volatilization or blooming. However, both have limitations. Intumescents appear to have little applicability for engineering resins. "Most intumescent systems today don't have the capabilities to be used at the high processing temperatures of these thermoplastics," says Ferro's Dever. As for reactives, Dever echoes the opinions of many when he says, "In certain polymers and certain processes there's a need for reactives. But the development costs are high and each system has to be tailored for a specific polymer. Reactives will be developed, but it has to be on a case-by-case basis. You won't see a reactive that can be used on four or five products." Ferro has recently concentrated on high-molecular-weight polymeric flame retardants as another approach to making them permanent and non-migrating.

One strong advocate of reactives is Dead Sea Bromine Co. of Israel, represented here by AmeriBrom Inc., N.Y.C. Sources there consider monomeric reactive flame retardants to be the most versatile technology for future developments. Besides being permanent and not apt to leave mold deposits during processing, they reportedly provide better physical properties and functional efficiency. They can also serve useful ancillary functions: crosslinking, compatibilizing blends, or serving as processing aids or coupling agents (PT, April '90, p. 67).

"The technology of the '90s will go toward locking the flame retardant into the polymer backbone where it won't come out easily," agrees Charles Ludwig, sales and marketing manager for Great Lakes Chemical Corp., W. Lafayette, Ind. Great Lakes is exploring the use of dibromostyrene (also available from AmeriBrom), a liquid, bromine-containing reactive monomer. "We're looking at ways of attaching the dibromostyrene molecule to dissimilar polymers," says Ludwig. "It's really not that difficult." He expects that if this work proves successful, a product could be commercial by the mid-1990s.

To whatever extent compounders move away from halogens, they will also reduce their need for antimony oxide as a synergist. The question of antimony oxide's possible toxicity remains unresolved (PT, July '89, p. 99). Results of the Antimony Oxide Industry Association's two-year study of possible health risks and toxicity levels from inhalation of antimony oxide dust are expected to be released soon. At issue is whether the EPA was correct in labeling the material a suspected carcinogen. Whatever the Association finds, antimony oxide suppliers say they are working diligently to supply it in dustless pellet or wetted forms to minimize health risks to compounders. They predict that antimony oxide-based flame retardants will survive because the synergism between antimony oxide and halogen remains, in their eyes, the most cost-effective flame-retardant system for plastics.

Still, some suppliers don't want to take the risk. Earlier this year, Mobay Corp.'s Plastics and Rubber division launched the first of a new generation of flame-retardant polycarbonate/ABS resins that are completely free of chlorine, bromine and antimony oxide (PT, July '89, p. 99). Eliminating these FR additives helps avoid blooming and plateout, Mobay says, and antimony oxide in the presence of heat and moisture can catalyze or accelerate the degradation of certain polymers, such as PC.


There have been suspicions about possible adverse health effects from DOP/DEHP and other phthalates for two decades, and more specific allegations that these substances might promote liver cancer have circulated for the past five years. Processors and suppliers expect the issue to persist well into the '90s. DOP is already on the SARA 313 and California Proposition 65 list of chemicals whose use must be reported to regulatory agencies, yet it continues to be widely used. "The market still considers DOP the plasticizer of choice," says Jeffrey G. Guidette, director of marketing for BASF Corp., Parsippany, N.J. By Guidette's estimate, phthalates comprise about 70% of the platicizer market. This, producers and users say, is simply a matter of economics: no cost-effective alternative has been found.

"there are people in the industry who feel that were there a truly equally cost-effective alternative, then, yes, DOP would be banned," says Steven Hopper, marketing manager for the C.P. Hall Co., Chicago. "There are lots of readily available materials to replace it, but they are all 10% to 100% more expensive."

One product that suppliers see as a possible replacement is diisononyl phthalate (DINP)--although, as Hopper warns, it is also a phthalate and therefore not above suspicion. Another possible replacement, some say, is dioctyl adipat (DOA).

BASF and other DOP producers, including Aristech Chemical Corp., Pittsburgh, and Eastman Chemical Products, Inc., Kingsport, Tenn., say DOP can survive as long as suppliers continue to develop safe handling practices for those using the product.


New product development in peroxide intiators for unsaturated polyesters has been effectively stymied for more than four years, since an EPA ruling based on the Toxic Substances Control Act made it economically unattractive for suppliers to attempt to market a new molecule (PT, July '86, p. 105). However, the possibility of negotiations between the EPA and SPI's Organic Peroxide Producers Safety Div. has suppliers hopeful that some of the restrictions will be eased and R&D efforts that have been put on hold can be reactivated.

In the meantime, some suppliers have long maintained that FRP molders have yet to fully investigate or exploit some of the newer initiators developed during the late '70s and arly '80s. Thus, productivity advances and other benefits are potentially available for everything from open-mold spray-up to SMC compression molding with some less well known but available catalyst systems.

First among the wishes expressed by processors is for catalysts that do not have to be refrigerated. In the last few years, there has been considerable debate as to whether fine-particle-size BPO/water emulsions might present such an alternative to MEKP for spray-up. With strong opinions on both sides of the issue, the jury is still out as to how broadly applicable such BPO products will turn out to be in the spray-up field, or whether they indeed offer an overall increase in safety, despite their lack of refrigeration.


Suppliers see more need for weatherable impact modifiers for PVC siding and window profiles, two of the fastest-growing vinyl applications, and say new acrylic and chlorinated polyethylene (CPE) formulations are being developed. "We believe acrylics are the best," says Atochem's Avento. "For what we see on the horizon, we feel acrylics will still be the product of choice."

However, notes Karn McDonie, Rohm & Haas' marketing manager for plastics additives, "There's not just one issue in impact modifiers for the '90s. In packaging, it's going to be organoliptics and reducing taste and odor."

Reactive impact modifiers that chemically graft onto the matrix polymer are seen by suppliers as a promising field for the '90s. This approach is said to provide compatibility with engineering resins that are typically hard to modify. Examples are Rohm and Haas' Paraloid EXL-3386 butyl acrylate modifier for nylon, polycarbonate and PBT (PT, Feb. '88. p. 23). and the newly developed all-acrylic Paraloid EXL-3387 for nylons 6 and 6,6 (See New Products Section).

Shell Chemical Co., Houston, also has a reactive version of its Kraton styrenic block copolymer.

Another area where suppliers see room for development in the '90s is expanding the use of impact modifiers as compatibilizers for polymer allows--reactive types also have a role here. This is reportedly already being done with some success in engineering resins, and suppliers say they want to expand into compatibilizing recycled plastic mixtures.


Processors say they would like to see improved uv stabilizers for resin systems such as polyurethanes and polycarbonates in the '90s. Suppliers plan to approach this in part by blending existing uv stabilizers with each other and with antioxidants in packages better suited to non-olefin polymers.

Hindered amines (HALS), which have come to dominate the uv-stabilizer field, next will be used in increasing amounts as primary antioxidants in a variety of polymers during the '90s, industry insiders believe. This trend, they say, will be due to HALS' ability to overcome some of the problems, such as discoloration and gas fading, experienced with traditional hindered phenolic primary antioxidants.

Elyse M. Lewis, GE Specialty Chemicals' market manager for phosphite antioxidants, warns that though HALS "may solve some of the problems," they will cost five to six times as much as phenolics; so no one will use them unless absolutely necessary.

The goal, many say, is combining advantages of several additives into one hindered amine, making it more cost-effective. "We're looking to embody as many characteristics as we can in our products," says Joseph Puglisi, sales and marketing manager for the Plastics Additives Div. of Ciba-Geigy Corp., Hawthorne, N.Y. "What we'd like is one product that can provide good uv light stability, thermal stability and process stability." Ciba-Geigy and other producers say they are experimenting with new amines, trying to apply them to as broad a range of polymers as possible. "There's still a lot that has to be evaluated and tested," Puglisi concedes. "The jury's still out. There may be situations where it just doesn't work."

Still, he says, preliminary indications show a positive future for amines. For instance, Ciba-Geigy's tests have shown that polymeric HALS have strong long-term heat-aging properties when used in plastics processed below 275 F. "Ten years from now we could see these as the dominant antioxidants," Puglisi speculates.

Last year, the Organic Peroxide Div. of Atochem North America, Buffalo, N.Y., introduced technology that allows uv stabilizers and antioxidants to chemically react with polymers, giving the polymers permanent stabilization that won't be lost to volatilization, migration or extraction. The Atochem technology allows hydrazide and peroxide-functional benzophenone HALS to be incorporated into a wide array of polymers, including polystyrene, nylons, polyesters, polycarbonates and some polyolefins (PT, Aug. '89, p. 14).


Donald Putzig, a researcher in Du Pont Co.'s Chemicals & Pigments Dept., Wilmington, Del., sees great promise in combining silanes and titanates into coupling-agent systems. "A combination of organosilanes and organotitanates as an additive packag can give better processing and performance properties than either one by itself," he says.

Already, such mixtures have been successful in fiberglass/polyester thermoset composites, alumina trihydrate-filled methacrylate casting resins, electronic potting compounds, and heat-resistant engineering plastics, Putzig reports.

A whole new thrust for some organometallic coupling agents in the '90s will be as compatibilizers in polymer alloying, rather than their traditional role of coupling fillers and reinforcements to a polymer matrix," says Salvatore J. Monte, president of Kenrich Petrochemicals, Bayonne, N.J.


"I anticipate the need for specific particle-size distributions of calcium carbonate in order to increase loading levels and also to improve or maintain physical properties at higher loadings," says Gerald D. Turner, sales manager for the Specialty Products Div. of Franklin Limestone Co. (formerly TAC Industries Inc.), Dalton Ga. Many suppliers agree with Turner's assessment, but add that other mineral fillers will also receive new attention.

"I really don't see a new industrial mineral on the horizon that will have a significant impact on a broad range of polymers," says William Sevy, industry manager for Cyprus Industrial Minerals, Englewood, Colo. "Rather, I think there will be a reallocation of interest," adds Glenn Conger, manager of new product development for the Clay Div. of J.M. Huber Corp., Macon, Ga. "People will take another hard look at Wollastonite and mica."


Microbiocides appear poised to dramatically increase their range of applicability in rigid thermoplastics such as ABS, polycarbonate, HIPS, acrylic, and rigid PVC. The challenge up to now has been finding a way to promote continual and sufficiently rapid diffusion of the biocide additive to the surfac of the polymer where it can do its work in inhibiting bacterial and fungal growth. Now, Morton International claims to have solved that problem with a new product, Vinyzene RP-1000, which consists of 5% of its arsenic-based OBPA active ingredient in a proprietary water-soluble resin carrier. It is this special carrier that provides mobility of the active ingredient throughout hard, glassy polymers. As explained by Kimberly A. Mullin, technical marketing specialist, this resin carrier forms "strings" or "channels" through the matrix polymer that provide routes for diffusion of the biocide.

This reportedly opens up huge new potential for biocides in such applications as telephones, auto parts, paper-towel dispensers, and computer or business-machine housings.


During the 1980s, nucleating and clarifying agents carved out a newly important niche for themselves in high-clarity PP, LLDPE and HDPE (PT, Nov. '89, p. 65). Processors now want nucleants/ clarifiers that can withstand higher end-use temperatures for PP products. The first step in that direction came late last year when Witco's Argus Div. capped five years of research with the introduction of Mark 2180, an FDA-approved nucleating agent based on sodium di(4-5-butylphenyl) phosphate, which can reportedly withstand processing temperatures up to 650 F (PT, Nov. '89, p. 67). And just last month, ICI Specialty Chemicals, Wilmington, Del., introduced Clarifex 800, a similar product for polypropylene that has FDA retort approval and allows processing up to 550 F.

A challenge for the '90s, processors and suppliers agree, is to optimize nucleants for LLDPE and HDPE to the point of those used in PP. "I want a nucleator/clarifier for LLDPE, HDPE and VLDPE that is FDA-sanctioned and effective with butene, hexene and octene comonomers," says Van L. Canady, manager of applied technology for Rubbermaid Inc., Wooster, Ohio. "They don't have one that's as effective as we'd like."


Makers and users of processing aids agree that the greatest need for the 1990s will be developing products compatible with engineering resins. "I think we'll have to get away from the standard materials we're using now," says Donald R. Hall, product manager for the Struktol Co., Stow, Ohio. "Maybe into ester-based materials that can provide better heat stability." Struktol is a relative newcomer to plastics additives (PT, May '90, p. 12).

In more conventional lubricants, improved handling will continue to be a goal. Synthetic Products is working on a calcium stearate in micro-bead form that is non-dusting and more dense than existing products. The company expects the small-particle-size calcium stearate and a zinc stearate for use in crystal-clear polystyrene to be commercial by the middle of 1991.


The trend toward reactive products apparent in flame retardants and impact modifiers is also having an impact on development of reactive antistats. Still in their infancy, the current state of reactive antistats has processors yearning for better products. "I'd like to see nonmigratory antistats which could be coupled with the polymer surface or added to surface coatings and adhesives," says Timothy Parker, project engineer for Dennison Manufacturing Co., Framingham, Mass. "We frequently do printing and decoration and these things tend to bloom. They are just not heat stable."

Suppliers say Parker is asking for the best of both worlds and, while they too would like to see such an antistat, it will not emerge in the near future. "However, you never know that could happen by the end of the decade," says James Carmine, business manager of coating additives for Akzo Chemicals.
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Title Annotation:plastics additives; includes article on non-chlorofluorocarbon mold releases
Author:Monks, Richard
Publication:Plastics Technology
Date:Jul 1, 1990
Previous Article:New PP copolymers & TPO's herald '90s 'engineering' polyolefins.
Next Article:Blend trends: compounding machinery in the 90's.

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