SIC 2816
INORGANIC PIGMENTS



This industry classification is comprised of establishments engaged in manufacturing inorganic color pigments, white pigments, and black pigments, including animal black and bone black. Carbon black is classified in SIC 2895: Carbon Black. Organic color pigments are classified in SIC 2865: Cyclic Organic Crudes and Intermediates, and Organic Dyes and Pigments.

NAICS Code(s)

325131 (Inorganic Dye and Pigment Manufacturing)

325182 (Carbon Black Manufacturing)

Industry Snapshot

Inorganic pigments serve the purpose of imparting color to various compounds. They also add properties such as rust inhibition, rigidity, and abrasion resistance. Pigments are insoluble substances that can be incorporated into a material to selectively absorb or scatter light. Depending on the specific pigment used, different visual effects are produced. Inorganic pigments may be obtained from a variety of naturally occurring or synthetically produced mineral sources. The counterpart, organic pigments, are carbon compounds derived from petroleum sources.

In comparison with organic pigments, inorganic pigments are generally better able to withstand the affects of sunlight and chemical exposure. They provide superior opacity, which means they can render a substance or object opaque by prohibiting light from passing through it. Inorganic colors, however, tend to be less bright, pure, and rich than their organic counterparts. Because inorganic pigments possess less tinting strength, more pigment is needed to produce the desired effect. This generally makes them more durable. Almost all inorganic pigments are completely insoluble. Consequently they do not bleed or leach out of coatings, inks, or plastics. In addition, inorganic pigments are usually less expensive than similar organic colors.

Pigments differ from dyes as a result of their distinctive chemical natures. Dyes are soluble, and to impart color they are dissolved in a carrier and applied by a process that involves chemical changes. Pigments however, remain unchanged physically and chemically. They function without altering their crystalline, particulate, or metabolic structures.

Inorganic pigments are classified as single-metal oxides, mixed-metal oxides, and earth colors. Single-metal oxides include pigments made from titanium, zinc, cobalt, and chromium. Mixed-metal oxides include pigments such as cobalt aluminate blue, which is used in ceramic glazes, and nickel antimony titanate, manganese antimony titanate, and chromium antimony titanate, which are used for outdoor coatings and plastic siding. Earth colors, including siennas, ochers, and umbers, are generally made from iron oxides and lead chromates. A method of high-temperature firing called calcination is used to produce pigments with improved heat resistance.

Pigment manufacturers supply inorganic colors in a variety of forms such as powders, pastes, granules, slurries, and suspensions. Pigment users include manufacturers of paints and stains, printing inks, plastics, synthetic textiles, paper, cosmetics, contact lenses, soaps and detergents, wax, modeling clay, chalks, crayons, artists' colors, concrete and masonry products, and ceramics.

Within the inorganic pigments classification, the largest selling individual pigment is titanium dioxide (TiO2), a white pigment with opacifying characteristics. Titanium dioxide is by far the most widely used white pigment in the world. It is a solid that melts at over 1800 degrees Celsius. It has a higher refractive index than everything except diamonds. It is polymorphous and exists in three crystal structures: rutile, anatase, and brookite. To utilize titanium dioxide's special properties, it must be developed to an ideal particle size. Most often, the particle size is one half the wavelength of visible light or about 0.3 microns.

Industry shipments declined in the late 1990s from $3.74 billion in 1997 to $3.42 billion in 1999, before rebounding slightly to $3.55 billion in 2000. The number of employees in the industry totaled 8,311 in 2000; roughly 5,600 were production workers.

Background and Development

The use and exploitation of color dates back to the prehistoric era. Pigments were made by grinding naturally colored materials into minute particles and then mixing them into a binder material. Some of the substances used to produce paintings on cave walls were still used during the twentieth century. For example, the reds used to produce the drawings in the Lascaux caves of southern France were made from red iron oxide.

During the early part of the twentieth century, the pigments industry relied heavily on lead-based ingredients. One ingredient, lead carbonate (white lead) was known to be toxic as early as the late nineteenth century, and although some countries began imposing restrictions on its use in the 1920s, the United States was not among them. The toxicity of lead carbonate, especially to children who ate paint chips, received increasing publicity. By the mid-1960s paint manufacturers were required to begin phasing out its use.

According to industry researchers, lead carbonate caused lead poisoning because of its solubility. The solubility enabled it to interfere with the human body's biochemical system. Investigators claimed that other lead pigments suffered from non-specific adverse publicity resulting in regulations that failed to differentiate between soluble and insoluble lead compounds. A reduction in the use of lead chromate pigments during the 1970s resulted in increased costs of more than $1 billion because available replacements were inferior. Into the late 1990s, this problem still existed and lead carbonate was still in use to some degree; advancements in the industry continued to make substitutes that were economically feasible and comparable in color strength.

To address issues such as environmental matters, tariffs, toxicity, and worker health, the Dry Color Manufacturers Association (DCMA) was formed. Originally organized in 1925 and headquartered in New York City, the trade association moved to New Jersey and then to Washington, D.C. In 1993, the organization changed its name to the Color Pigments Manufacturers Association, Inc. (CPMA) and as of 1997, it was located in Alexandria, Virginia.

Growth in production and demand for titanium dioxide increased rapidly through the 1980s. By 1989, production was 67 percent above the 1982 level. Although demand declined in 1990, industry analysts predicted annual domestic growth within the titanium dioxide market of about 2 percent through the decade. Globally, demand was expected to increase about 3 percent per year. Paint and coatings manufacturers used almost half of the titanium dioxide produced in the United States. Other users included the plastics, rubber, printing inks, floor coverings, ceramics, textiles, cosmetics, and paper industries.

Manufacturers used two basic processes to make titanium dioxide. The sulfate process, which produced slightly less than half of the world's supply of titanium dioxide, was the older method. It used sulfuric acid to dissolve the titanium dioxide. Further refinement was required to produce different grades of the finished product.

The newer method, called the chloride process, centered around the use of chlorine and accounted for 51 percent of the world's titanium dioxide capacity. By this method, chlorine was reacted with titanium-containing minerals to produce titanium tetrachloride. The titanium tetrachloride was reacted with oxygen to form titanium dioxide and recyclable chlorine. Advantages of the chloride process included its ability to create higher grades of titanium dioxide without additional handling, its use of less labor and equipment, and its ability to produce in a continuous, as opposed to a batch, process.

The chloride process also produced a smaller volume of waste by-products. Up to 12 tons of waste material were generated when the sulfate process was used in making one ton of titanium dioxide from ilmenite. The chloride process generated four to five tons of waste in producing the same amount of titanium dioxide. A large part of the wastes generated by the chloride process, however, consisted of iron chloride. Disposal of iron chloride created controversy because of its acidic properties and hazardous nature. To reduce the amount of iron chloride waste, manufacturers were forced to rely on higher priced rutile or other purified forms of titanium-containing raw materials. High grade rutile generated only about 70 pounds of iron chloride to yield one ton of titanium dioxide.

New and existing grades of titanium dioxide were made more similar to each other as paint formulas became more standardized around the world. Slight regional differences, such as particle size or degree of opacity, were being phased out by the industry. Leaders in this trend as of 1996 were DuPont's R-706 multi purpose pigment for coating applications and SCM's RCL535. Kronos and Kerr-McGee were also working on similar products.

Titanium dioxide was also being used to create synthetic pearlescent pigments. Pearlescent pigments, a twentieth century innovation, were developed in an attempt to create the visual sense of depth associated with natural pearls. Initial pearlescent pigments were made from crystals obtained from fish scales. Rosary bead manufacturers were among the first users of these products.

Researchers identified two chemical compounds with similar light reflective properties. One of these, carbonate white lead, was withdrawn because of its toxicity. The other bismuth oxychloride found wide use in applications such as cast polyester buttons, automotive paints, fingernail enamels, cosmetics, wall papers, and plastics.

Synthetic pearlescent pigments, however, failed to exactly duplicate those of fish scales. The search for other synthetic pearlescent pigment compounds led to the use of such minerals as mica. Mica, when coated with titanium dioxide, was judged to reflect light in a manner suitable for use in pearlescent pigments.

The second largest family of pigments was iron oxides. Although iron oxides produced pigments in a wide range of colors, reds accounted for almost half the consumption. By the early 1990s, synthetic iron oxides had captured two-thirds of the market. Industry forecasters expected increased interest in synthetic iron oxide pigments because they offered improved color strength over naturally occurring ores. The primary users of iron oxide pigments were paint and coatings manufacturers.

Lead chromates represented the third largest family of pigments. In the early 1990s, approximately 42 million pounds of these pigments were still being sold annually. Traffic paint manufacturers used nearly 18 million pounds of these pigments. Despite their popularity, lead chromates were being subjected to increasing congressional scrutiny because of concerns about lead toxicity and environmental integrity.

Silica encapsulation involved encasing pigment particles or crystals within a shell of silica (a glass like substance). Researchers claimed that encapsulated lead chromate pigments were protected from chemical, photo-chemical, and thermal degradation. The encapsulation process also reduced their toxicity by making them less soluble in the body. Researchers also claimed that silica encapsulation improved the brightness and intensity of the pigments, making them better suited for use in high-temperature applications such as plastic manufacturing.

Environmental Impacts. Questions about environmental degradation and the toxicity of heavy metals challenged the inorganic pigment industry throughout the 1980s and early 1990s. Heavy metals such as lead, cadmium, chromium, and mercury were associated with ailments including cancer and liver disease. Both the Congress and the Environmental Protection Agency (EPA) considered legislative and regulatory initiatives to control, limit, and in some cases ban, the use of several of the industry's essential raw materials. Some manufacturers responded by backing away from heavy-metal pigments. Others defended their formulations and offered evidence that if raw materials were banned, certain colors would become unavailable.

In addition to struggling with direct toxicity problems, pigment manufacturers faced charges claiming that their disposal of heavy-metals used in pigments were threatening the nation's water supplies. Products under-going incineration or degradation in landfill sites created a potential hazard as heavy metals were released into the environment. As a result of this growing environmental concern, the Conference of North East Governors (representing nine northern states) and the legislatures in several other states, began working toward bans on heavy metals in packaging materials. During the early 1990s, industry watchers expected the number of environmental regulations regarding the use of heavy metals in pigments to increase.

An often cited example of the difficulties faced by industries forced to switch away from heavy metal inorganic pigments was the problem of the Pennzoil oil bottle. The Pennzoil oil bottle, fabricated from an identifying bright yellow plastic, depended on yellow lead chromate. During the early 1990s yellow lead chromate cost between $1.00 and $1.50 per pound, but as legislation was likely to continue to limit the use of lead chromate, the company was forced to look for substitutes for the ingredient. One commonly used substitute cost between $6.00 and $7.00 per pound and other organic yellows cost up to $30.00 per pound. Facing a similar situation, Caterpillar (a manufacturer of heavy equipment) switched from its traditional color to a less bright yellow.

Current Conditions

According to figures released by the U.S. Census Bureau, shipments of inorganic pigments totaled $3.5 billion in 2000, a marked decrease from the $3.7 billion shipped in 1997. The largest end user was the paint and coatings industry.

In 2000 the industry's 74 establishments employed 8,311 people, 5,602 of whom were production workers. These production workers earned an average hourly wage of $21.52, far above the manufacturing industry's average.

Industry Leaders

The largest U.S. corporation producing inorganic pigments in 1999 was Millennium Chemicals, Inc. of Iselin, New Jersey. With sales of $1.6 billion, Millenium has approximately 5,300 employees and is the second largest producer of titanium dioxide. Ferro Corp. of Cleveland, Ohio had 1999 sales of $1.3 billion and 6,900 employees. Ferro began operating in 1919 as a frit manufacturer. Frit is a special glass material used to produce porcelain enamel and ceramic glaze. Color pigments for the ceramics and coatings industries were added to the company's product line in 1939. The company began supplying pigments to the plastics industry in 1947. By 1993, Ferro operated 12 color production facilities and sold its products in more than 100 countries.

Ferro's line of inorganic mixed metal oxide pigments are used primarily to color vinyl siding, window profiles, appliance housings, garden tools, and automotive components. The company's ultramarine blue and violet pigments are manufactured in Spain from sodium aluminum sulfosilicate complexes. They find use in thermoplastic resins, rubber compounds, paints, printing inks, artists' colors, and roofing granules. A third line of colors, called complex inorganic color pigments, are man-made minerals that are heat-stable, light-stable, and weather resistant. According to the manufacturer, they are the most chemically resistant pigments known to exist. They are recommended for use in exterior building applications and engineering plastics.

Other large inorganic pigment companies in the United States in 1999 were NL Industries Inc. of Houston, Texas; Kronos Div. of Houston, Texas; and Engel-hard, Inc. of Iselin, New Jersey.

America and the World

In 1990, estimates suggested that titanium dioxide accounted for about 30 percent of global pigment sales, and demand for the white pigment was expected to grow at approximately 3 percent per year. Industry forecasters expected new global production capacity that would add 850,000 tons between 1990 and 1995, resulting in a slight over-supply that would stabilize prices.

Western Europe however, was expected to see reduced production. Approximately 73 percent of the region's existing capacity was based on the sulfate process, which was subject to increasing criticism from environmental groups. A European Union directive to stop ocean dumping of wastes, slated to take effect at the end of 1993, was expected to increase operating expenses by about 15 percent and force older plants out of the global market.

Heavy metal pigment manufacturers were also facing difficulty in some parts of the world. In Japan, cadmium was replaced in 1980. European manufacturers began phasing it out several years later. An estimated 50 to 60 percent of European cadmium production had been eliminated by 1990. Some industry observers suggested that the banning of heavy metal pigments resulted in an increased reliance on duller colors.

Rare-earth-based red and orange pigments were scheduled for production in the 3rd quarter of 1997 when Rhone-Poulenc SA planned to start its 500 metric ton per year operation at La Rochelle, Les Roches-Roussillon and Clamecy. This inorganic pigment, trade-named Neolor, would be an environmentally friendly alternative to cadmium and lead-based paint types.

An advance in the making of complex inorganic color pigments by Englehard Corp. brought about the reddest pigment of it kind for use in PVC, nylon and other engineering plastics in 1996. Meteor Plus 9384 had 70-80 percent greater color strength than the next closest complex inorganic color pigment with a red value.

Further Reading

Alperowicz, Natasha, and Ian Young. "DuPont to Raise Prises; SCM Plans to follow Suit." Chemical Week 11 December 1996.

Darnay, Arsen J., ed. Manufacturing USA. 6th ed. Detroit: The Gale Group, 1999.

Dry Color Manufacturers' Association. "Pigments—A Primer." American Ink Maker, June 1989. Reprinted by Color Pigments Manufacturers Association, Inc. (formerly DCMA).

——. "Inorganic Mixed Metal Oxide Pigments." Cleveland, OH: Ferro, nd.

"Inorganic Pigments." Standard & Poor's Industry Surveys. New York: Standard & Poor's Corporation, 1997.

MacDonald, Cindy. "New Technologies Boost Performance." Canadian Plastics, February 1996.

Parkingson, Gerald. "Rhone-Poulenc Will Commercialize 'Friendly' Pigments." Chemical Engineering, October 1996.

"Production By the U.S. Chemical Industry: Production Growth Sputtered in Most Sectors." Chemical and Engineering News, 24 June 1996.

SCM Chemicals. Titanium Dioxide in Today's Environment: A Responsive and Responsible Industry. Baltimore, MD: SCM, nd.

"SCM to Reduce TiO2 Capacity, Hike Prices." Modern Paint and Coatings, September 1996.

Shearer, Brent. "Pigments Fade." Chemical Marketing Reporter, 21 October 1996.

——. "Ultramarine Pigments." Cleveland, OH: Ferro, nd.

United States Census Bureau. "Statistics for Industries and Industry Groups: 2000." Annual Survey of Manufacturers. February 2002. Available from http://www.census.gov .



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