Alexander H. Tullo
C&EN Northeast News Bureau

Additives are often-ignored components of plastics. In discussions of  the market success of polyvinyl chloride or polypropylene, for instance, only the polymers are usually mentioned, and little credit is given to the chemistries that enable these products to be as useful as they are.

	[Cytec photo]

Sometimes there is good reason for this. Because certain types of additives haven't changed for decades, their growth often tracks the polymers that they are used with, and their presence is often forgotten. But in other cases, as when environmental and health concerns arise over their use, plastics additives take center stage until the industry finds a way either to replace the troublesome additives with newer varieties--often without government mandate--or, if possible, to prove its products are essentially harmless.

Plastics additives are big business for the specialty chemicals industry. According to Fred Gastrock, a consultant with BRG Townsend , a Mount Olive, N.J.-based chemical consultancy, the global market for plastics additives was $15.5 billion in 1999, representing nearly 18 billion lb of material. Included in these figures are data for plasticizers, impact modifiers, heat stabilizers, lubricants, biocides, antioxidants, antiblocking agents, slip agents, light stabilizers, clarifying agents, flame retardants, organic peroxides, blowing agents, antistatic agents, and coupling agents. Excluded are colors and fillers.

Gastrock says the entire sector is growing by about 4 to 5% annually, with North American and European markets climbing 3% per year, and Asia and the rest of the world growing at 6 to 8%.

Plasticizers are by far the largest class of plastics additives. Global volumes of plasticizers, according to Gastrock, were about 10 billion lb in 1999 and were valued at about $5 billion. Growth in this mature market is a modest 2 to 3% per year.

However, recent years have brought controversy to the plasticizer marketplace. Chemical and plastics industry organizations have lined up against environmental groups over plasticizers used in flexible PVC, such as diethylhexyl phthalate (DEHP) and diisononyl phthalate (DINP), because of potentially adverse effects on the human reproductive system. Because of the attention, some manufacturers have moved away from using vinyl-based products in toys that babies suck on, and others have introduced alternatives to vinyl-based medical devices.

Gastrock says losing the toy applications has had little impact on the phthalate plasticizer and PVC markets because less than 1% of phthalate plasticizers are used in toys. A ban on phthalate plasticizers in medical products would be more serious, he says, because that represents about 10% of the phthalate plasticizer market.

D'Lane Wisner, director of environmental solutions at plastics compounder PolyOne, says phthalates in vinyl medical products like IV bags and medical tubing have raised little concern until recently. "The use of phthalates in vinyl medical products has been around for 30 years," he points out. "The fact that the Food & Drug Administration has chosen not to take a position against them in all these years is a tremendous validation in and of itself."

Another strength of phthalate plasticizers, Gastrock says, is that they are hard to replace. "There are aliphatics, trimellitates, phosphorous materials, citrates, epoxies, and polymeric types, and they all have their little niches, but none of them has been able to take over or find broad use in most phthalate markets," he explains.

Flame retardants

Halogenated flame retardants are also coming under fire. Plastics containing certain brominated flame retardants are believed to release polybrominated dibenzo-p-dioxins and polybrominated dibenzofurans when incinerated. The fear is that workers in recycling and processing plants can be exposed to dangerous levels of the chemicals.

While there have been no bans, the World Health Organization has recommended against the use of brominated flame retardants when substitutes can be found. In addition, manufacturers of end-use products that do not use brominated flame retardants and other halogenated compounds are rewarded through qualification for various voluntary environmental labeling programs in Europe.

According to Gastrock, the global market for all varieties of flame retardants is $2.2 billion, with volumes at around 2.2 billion lb. But Gastrock points out that, despite the hullabaloo, brominated flame retardants are still growing by 5% per year.

Nonetheless, European governments have been closely scrutinizing brominated flame retardants; in particular, those based on diphenyl oxide, says John Nicols, Albemarle's global business director of flame retardants. "Over the last year and a half, there has been a fair amount of toxicological work," he says, noting that this could be good for the industry, if, as he believes, some classes of brominated flame retardants are given a clean bill of health and a consensus on their use is reached.

Although Europeans are keeping an eye on brominated flame retardants, they are becoming increasingly concerned with fire safety, says William Neagle, flame retardants business director of Great Lakes Chemical , a major producer of brominated flame retardants. "Debate over the use of flame retardants is surging back in favor of brominated flame retardants," he says.

Moreover, flame retardants are used because regulations put them in plastics in the first place, Gastrock notes. "No one is going to ban the things because you have a danger from something called fire," he says.

Neagle says European regulators are considering requiring more flame retardants in televisions and other products and that some furniture makers are voluntarily adding flame retardants to polyurethane cushioning for household use. The growing popularity of products containing flame retardants has boosted demand for flame retardants of all kinds, Albemarle's Nicols says. "The boom in electronic equipment has helped flame retardants broadly," he adds.

In addition, flame retardants have benefited from requirements in the U.K. and in California, among other states, mandating them in polyurethane cushioning for institutional furniture. Though this has increased demand for brominated flame retardants, it has also led to growing use of melamine crystal flame retardants.

Neagle admits, however, that despite high growth, brominated flame retardants are losing market share. "If you can have a nonhalogenated flame retardant that gives you the same performance, then customers will use it," he says. Brominated flame retardants are also losing ground because of the growing use of polycarbonate/acrylonitrile-butadiene-styrene blends--which can use either halogenated or phosphate ester flame retardants--over ABS, in which brominated flame retardants are used.

But it might be hard to find alternatives to brominated flame retardants in other applications, Gastrock says. "A lot of people are trying to make phosphorus work," he says. "There are also melamine and ATH [alumina trihydrate] materials. None of these is the answer; they all have problems one way or another. In ATH, for example, you have to put 50% loading in the plastic for it to work in some applications. This would have negative effects on the plastic's performance properties," he points out.

Some brominated flame-retardant makers are diversifying their portfolios to play it safe. Last year, Great Lakes purchased for $162 million FMC's process additives business, which, among other products, makes phosphate ester flame retardants and flame-retardant fluids. "We are not hedging our bets," Neagle says. "Great Lakes has realized that there's some shift in the market." In another move to strengthen its flame-retardant business, the company is consolidating all of its global manufacturing of antimony trioxide to Reynosa, Mexico.

Albemarle has also been developing nonbrominated flame retardants. The company formed an alliance with Borax Polymer Additives Group to develop zinc borate flame retardants and synergists. Albemarle will market the boron zinc flame retardants in Asia and will also sell any new flame retardants the collaboration develops. In addition, Albemarle has introduced its own line of phosphorus-based flame retardants, initially aimed at polycarbonate/ABS blends and other engineering polymer systems.

But Albemarle is also continuing to invest heavily in its bromine chemistry. It has established Jordan Bromine Co. with two partners in the Middle East. The partnership will establish a bromine and bromine derivatives plant, including a 50,000-metric-ton tetrabromobisphenol A plant in Safi, Jordan, in mid-2002.

Heat stabilizers

As with flame retardants and plasticizers, there are environmental issues for heat stabilizers, and, because of these issues, different additives are favored around the world.

The global heat stabilizer market is valued at about $1.8 billion, representing volumes of between 1.1 billion and 1.2 billion lb, according to Gastrock. The growth of heat stabilizers, at 4% per year, tracks the PVC market. Almost all heat stabilizers are used in either rigid or flexible PVC. The main kinds of heat stabilizers are organotins; lead; mixed metals such as barium/cadmium, barium/zinc, and calcium/zinc; and organic materials that companies are beginning to introduce.

In North America, lead is only found in wire and cable applications. Instead of lead, organotins are dominant in North America in rigid PVC applications, such as pipe. On the other hand, lead is used in all sorts of rigid applications in Europe, and some plastics converters and governments are phasing it out. Asian markets are somewhere in between North America and Europe in the predominance of lead.

In mixed metals, Ca/Zn has a better image than Ba/Zn or Ba/Cd, but it doesn't perform as well in many applications. "Ca/Zn will probably do better in the market than the others down the road," Gastrock says, adding that global growth in Ca/Zn and organotins will be more than 4% in the long run, while growth in lead and other mixed-metal classes will remain flat or decline. In North America, on the basis of volume, tin and mixed metals each accounts for about 40% of the heat stabilizer market and lead accounts for less than 20%, according to Gastrock's figures. In Europe, lead accounts for nearly 70% of the market, while mixed metals represent about 20%, and organotins, a mere 10%.

Polymer additives research at Ciba. [Ciba Specialty Chemicals photo]

Crompton Corp. , one of the largest players in heat stabilizers, exited cadmium- and lead-based heat stabilizers a decade ago, according to John Hamilton, market manager of vinyl additives for Crompton's Witco polymer additives group. The move was part of the company's push to convert these markets to Ba/Zn and Ca/Zn.

"A lot of the conversion took place several years ago, so today cadmium is pretty small," says Sally Lenhart, Ferro Corp.'s worldwide business director for polymer additives. "It is only used today when there are no alternatives."

As they phase out lead, Europeans will probably skip organotins altogether and opt for Ca/Zn instead, says William Hrubik, PolyOne's director of sourcing. "In Europe, all of the heavy metals have perception issues that are much greater than in the U.S. Rather than going to tin, they are trying to see if they can use Ca/Zn stabilizer technology in rigid applications," he adds.

Crompton's Hamilton agrees. "Throughout Europe, pipe is stabilized with lead, and they want to knock out heavy metals completely," he says. "In Europe, Ca/Zn is what they are going to. They look at organotin as an interim solution," he adds. Crompton has been developing a Ca/Zn replacement for lead in rigid applications for the European market and is currently working on getting approvals for drinking-water pipe and food contact uses.

Crompton is also working on a Ba/Zn stabilizer for wire and cable. Lead, Hamilton says, is difficult to replace in this market because it is perfect for the applications. Lead has been the only heat stabilizer good enough to allow electrical wiring to pass stringent standardization tests. "Lead is the best stabilizer you can possibly use," he says.

Ferro is working on the development of organic stabilizers, Lenhart says, noting that, in the long run, they could solve the lead problem in Europe. But it will take time for them to catch on, she admits. "Nobody is clamoring for organic stabilizers, but we have to be prepared," she adds.

Antioxidants

Antioxidants are used in every kind of plastic, but polyolefins account for about 60% of global demand. In all, antioxidants have a $1.3 billion market globally, and volumes of about 500 million lb, Gastrock says. Growth in the market is about 4%, tracking the entire polymers sector.

The major types of antioxidants are the primary antioxidants--butylated hydroxytoluenes (BHT) and other hindered phenols--and the secondary antioxidants--phosphites and thioesters. Primary and secondary antioxidants are used in combination, Gastrock says.

One of the greatest changes that has occurred in antioxidants during the past decade has been the effects of Ciba Specialty Chemicals' Irganox 1010 and 1076 coming off patent. This led to a number of producers, such as Great Lakes as well as some in Asia, entering the market with clones. When this happened, prices for the popular hindered phenols plummeted. "They used to sell for $5.00 to $6.00 per pound, and now prices can be as low as $2.00 to $2.50," Gastrock says. "Ciba had a nice run," he adds, noting that the company still has about half of the market, with Great Lakes as its closest competitor.

Felix Meyer, head of Ciba's global polymer additives business, says prices are stabilizing, and the company has found ways, such as value-added blends with other antioxidants and plastics additives, to hold on to market share. He notes also that some competitors have gone out of business. "For some of these competitors, manufacturing the products wasn't attractive anymore," he adds.

Great Lakes took advantage of this trend. It bought a foothold in the antioxidants business through three acquisitions in the early and mid-1990s to broaden its portfolio beyond flame retardants. Through these purchases, Great Lakes obtained hindered phenol and phosphite antioxidants as well as light stabilizers.

These companies were also making Irganox clones and soon found themselves in over their heads. Prices for hindered phenols plummeted, and the producers needed to consolidate, says Henri Steinmetz, vice president and general manager of Great Lakes' polymer stabilizers business. "We thought it was a very good move to be able to consolidate rapidly--to be in the situation to very quickly become a strong number two to Ciba," he adds.

Steinmetz says a key focus for Great Lakes in antioxidants is to keep costs down by building large and efficient capacity to produce common grades of antioxidants. He says this is what the company has been able to do at its plants in the U.S., South Korea, and Europe. The company is planning on repeating this in a new construction project under way in Al Jubail, Saudi Arabia.

The plant, which will be a joint venture between Great Lakes and Al-Zamil Group, will produce antioxidants and blends and is expected to start up during the third quarter of 2001. Steinmetz says the joint venture will sell directly to the large number of olefins producers building capacity in the region. These resin makers will add the antioxidants straight to their general-purpose grades of resin before they export to Asia and Europe. "The Middle East will emerge as one of the prime polyolefin-producing areas of the world," he says. "We wanted to be one of the first ones building greenfield manufacturing in this area."

Light stabilizers

Light stabilizers are among the most expensive plastics additives. The global market of $530 million represents only about 60 million to 65 million lb of material, Gastrock says. With annual market demand climbing 6 to 7%, they are among the fastest growing plastics additives. This is mostly because they ride the coattails of polypropylene, perhaps the fastest growing commodity polymer.

Resin pellets at a compounder. [Ciba Specialty Chemicals photo]

"Ultraviolet stabilizers are somewhat in fashion," Great Lakes' Steinmetz says. "In automotive uses, there is a big push to have UV-stabilized polypropylene. And then there's garden furniture, where people are looking for longer life and UV protection," he says, noting that polypropylene fiber is also a big outlet for UV stabilizers.

"There has been growth for polypropylene in exterior applications because of the versatility of the polymer itself," Ciba's Meyer says. "From a cost perspective, polypropylene is ideal. If you enhance it by giving it stability and some other properties, this is an even more attractive polymer." Ciba is a major global producer of hindered amine light stabilizers and is expanding global capacity by about 30% in various projects, including a new unit for high-molecular-weight hindered amines in Puebla, Mexico, in 2002.

Robert Gray, global marketing director of Cytec's polymer additives business, says hindered amine light stabilizers are among the fastest growing light stabilizers, even though they are already well established.

Cytec is also rejuvenating an old product: chelated nickel phenolate. Around for decades, nickel retreated out of the light stabilizers marketplace because of the emergence of effective hindered amines. "Nickel has become a niche product in areas where hindered amines do not work as well," Gray says, adding that it is incorporated in agricultural films used with roses, for example. Ag films are used for mulching and to cover greenhouses, among other uses. "Roses are one of the most difficult areas to use ag film in because sulfur is burned to fumigate them. That has a dramatic effect on other light stabilizers," he explains.

As in antioxidants, expired patents are also an issue in the light stabilizer market, Gray says. And Cytec and Ciba both are feeling the effects. Cytec's most popular light stabilizer--Cyasorb UV 3346--a high-molecular-weight hindered amine used in rotomolded polyethylene, agricultural films, and other polyolefin products, has about a year left on its patent. "I think it is possible and likely that we will have competition with the products, and that is something we will have to deal with," he says.

Antistatic agents

The antistatic agent market is about $130 million and 60 million lb globally, according to Gastrock, with growth between 4 and 5% per year. The biggest change in the market, he says, is that permanent antistatic agents are growing faster than migratory antistatic agents. Permanent antistatic growth is being driven by strong sales of document-handling office equipment and electronic equipment.

But temporary antistatic agents are growing robustly, too, says Dave Doles, associate director of marketing for performance chemicals for Lonza , a maker of fatty acid esters, which are temporary antistatics, for the plastics industry. They are growing at 6 to 7% per year because of their role as processing aids for polypropylene and PVC.

Crompton's Hamilton says the company is planning to expand its antistatic business because of the high growth for electronic equipment. Cytec, Gray says, is looking at its options for its antistatic additives business to enhance its portfolio. "These are a pretty small part of our product line," he says. "We are evaluating where we are, and are evaluating what our next step should be," he says. Among other options, the company is considering expanding its product line.

Antistatics are a small part of Lonza's business as well, and the company has no plans for major expansions in the segment. Instead, the company is focusing on its lubricant additives and is launching a product in polyethylene, a relatively new area for Lonza. "We haven't done a lot in polyethylene. We've focused on polypropylene and ABS," Doles says. Lonza claims the new product, Glycolube ML-2, when used in linear low-density blown film applications, can reduce the costs of melt fracture additives packages by 40%.

Deals and partnerships

Consolidation has also played a part in the plastics additives industry. The biggest deal in recent years, perhaps, has been the merger of Witco and Crompton & Knowles to form Crompton Corp. This transaction combined Witco's business in PVC additives with polyolefin additives such as antioxidants that came from Crompton's Uniroyal Chemical business.

Strategic alliances have also been popular in plastics additives. For example, the partners at PolymerAdditives.com think of their joint venture as more of a strategic partnership than just another e-commerce initiative. The site was founded by Cytec, Albemarle, and GE Specialty Chemicals to provide antioxidants, antistatic agents, curatives, flame retardants, impact modifiers, UV light stabilizers, and process aids to customers online.

Polyethylene-based greenhouse film often contains pesticide-resistant light stabilizers. [Cytec photo ]

"In the past few years, there has been consolidation--and analysts had been predicting more consolidation," Cytec's Gray says. "The problem with GE, Cytec, and so on is that no one wanted to sell its business. What you are seeing now is more partnerships and alliances.

"PolymerAdditives.com is e-commerce, but it is also more of a partnership," Gray continues. "We are taking pieces of companies where there is very little, if any, overlap and putting together something that gives us a very broad offering."

The company intends to sign on more suppliers, particularly in products it doesn't sell, such as clarifiers and additives used in PVC. "We have ongoing discussions with other polymer additives suppliers," says John McChesney, business director for PolymerAdditives.com. "Our ultimate goal is to have a complete range of polymer additives," he notes.

Ciba is using a combination of small acquisitions and strategic partnerships to improve its plastics additives portfolio. Meyer says Ciba has gradually been broadening its focus. "Traditionally, Ciba has been focusing on polymer stabilization," he says. "In recent years, we've gone more and more into enhancing the polymer product with special effects." Such additives, Meyer says, include flame retardants, oxygen scavengers, and clarifying, slip, and antistatic agents.

Ciba recently purchased the Amosorb 2000 inorganic oxygen scavenger line from BP and renamed it Shelfplus O2. The products are used as oxygen barriers in polyolefin packaging. "The benefit for the end user is extended shelf life, and we have other products that support this, such as products that protect food from light deterioration," Meyer adds.

Ciba is also expanding the cooperation it had with ICI subsidiary Uniqema in antistatic and antifog additives. This year, Ciba became Uniqema's exclusive distributor of erucamide, oleamide, and stearamide products used as antislip agents. "We did not have slip agents in our portfolio, and surface-active products are becoming a core competence of Ciba," Meyer says.

Blends

One plastics additives business that is taking off is blends, Great Lakes' Steinmetz says. Great Lakes and other additives suppliers are blending the products they make with a few they don't to give customers products in a single, easy-to-use package. Steinmetz says Great Lakes is packaging its antioxidants with antislips, antiblocks, acid scavengers, clarifiers, and other products. The advantages to customers are improved blending and lower capital costs. The business, he adds, is growing by 40 to 50% per year for Great Lakes. "We see a strong trend in the industry going to blends at the moment, rather than looking for new molecules," he adds.

But blends are not the focus for every company, says Cytec's Gray, who points out that most large customers of antioxidants are polymer suppliers. Cytec focuses more on UV stabilizers used by compounders and masterbatch suppliers that are in the business of formulating. For these customers, blends from additives makers do not accomplish much. "For us to provide light stabilizers and give them to customers in a package isn't a huge advantage for them because they are mixing multiple components together anyway," he says. "In fact, they can view it as a threat."

But PolyOne's Hrubik is not concerned by these developments. He says such products will be used by either the resin maker or the converter, with compounding companies keeping their niche in between. "There is no conflict or threat from various parties in the value chain," he says.

Lincoln Ying, general manager of plastics additives for Atofina , points out that ensuring that different additives work together has, for years, been a major service for plastics additives companies to provide. For example, he calls Atofina's portfolio of acrylic impact modifiers, stabilizers, and lubricants a "three-legged stool" for PVC compounders, on which Atofina has taken years to perfect formulation chemistry. "In this industry, discrete chemistry does not sell," he says.

Almost all plastics additives makers agree. Moreover, they believe that with stiffening environmental and product requirements, clones being made for goods that have come off patent, and other changes in the industry, their best defense is being able to provide value-added chemistry to their clients.

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Sixty years ago, Bakelite and other early resins made radios and telephones colorful and sleek, works of art that are still collected today. This sense of style was lost as a new generation of gadgets was developed, and off-white computers and black cellular phones were accepted as the norm.

But Apple Computer woke up equipment makers in 1998 when it introduced the translucent blue iMac. Its sales improved and other computer makers quickly knocked off brightly colored PCs of their own. They learned again that pretty colors on the outside of a machine can be an important difference when a number of competitors can offer the same basic technology inside.

GE Plastics , the resin maker behind a portfolio of special-effect materials that appear in the Iomega zip drive and the rainbow of Nokia cellular phones, is not only preparing for these changes, it is trying the best it can to facilitate them. The company has developed two new tools that it hopes will make it the resin company of choice with plastics parts designers.

One is its string of new design centers. The company recently opened one in Selkirk, N.Y. That facility contains a library of some 20,000 color chips, or standards, that customers can use to compare and match different colors to a number of effects, such as diffusion or pearlescent and metallic.

The facility can blend resins on-site and produce color chips with the new combinations. If a designer brings in a sample tool, the facility's on-site injection molding machines can even make prototype parts.

"At the end of the day here, a customer can leave with an exact color and effect standard for its new product, a first batch of resin, and actual parts with the custom-designed plastic," says Greg Quinn, director of GE Colorxpress Services, the organization GE has devoted to the coloring of plastics.

GE spent about $3 million on the new design center, and about $10 million on Colorxpress overall. A one- to two-day visit like Quinn described can cost a designer up to $20,000, and GE predicts that many clients will use the facility each week.

The firm has another center onstream in the Netherlands, and it is planning an Asian facility for 2001.

GE, which says its annualized rate of sales of plastics products on the Internet is approaching $1.5 billion to $2 billion, is using its e-business muscle to roll out similar capabilities online.

Users of GE's colorxpress.com website can select colors using Pantone and other color standard reference systems to select from among 20,000 colors and view diffusion effects. Because of a calibration system that installs itself as a cookie on the user's computer, resins matching the standard on-screen color or ones with special effects can be blended, and color chips can be fabricated and sent to customers within 48 hours after an order is registered. A color chip made using this service costs $350.

[GE Plastics photo ]

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