Published March 2015
The major change that has taken place in the coatings industry during the last 40 years has been the adoption of new coating technologies. Until the early 1970s, most of the coatings were conventional low-solids, solvent-based formulations; waterborne (latex) paints, used in architectural applications, accounted for 30–35% of the total. In the late 1970s, however, impending government regulations on air pollution control focusing on industrial coating operations stimulated the development of low-solvent and solventless coatings that could reduce the emission of volatile organic compounds (VOCs). Energy conservation and rising solvent costs were also contributing factors. These new coating technologies include waterborne (thermosetting emulsion, colloidal dispersion, water-soluble) coatings, high-solids coatings, two-component systems, powder coatings, and radiation-curable coatings.
Coatings provide two primary functions—decoration and protection—that are of considerable economic importance. About 45% of the coatings produced worldwide are used to decorate and protect new construction as well as to maintain existing structures, including residential homes and apartments, public buildings, and plants and factories (referred to as architectural or decorative coatings or simply, “paints”). Another 40% of the coatings are used to decorate and/or protect industrial products (called “product finishes”). Without coatings, product lives might be shortened drastically and many products would not even be marketable. Most of the remaining coatings, called “special purpose,” are used for miscellaneous applications such as traffic paints, vehicle refinishing, high-performance coatings for industrial plants and equipment, and protection of marine structures and vessels. These are usually applied outdoors in ambient conditions.
The following pie chart shows world production of paints and coatings:
The paints and coatings industry in the United States, Western Europe, and Japan is mature and generally correlates with the health of the economy, especially housing, construction, and transportation. Overall demand from 2014 to 2019 will increase at average annual rates of 3% in the United States and 1.5–2.5% in Western Europe. In Japan, however, consumption of paints and coatings will experience relatively slow growth during this period (0.5%), as a result of no growth in major markets such as automotive OEM, machinery, and appliances.
In the emergent countries of the world, coatings are growing at a much faster rate. The best prospects for growth are in Asia Pacific (4–5% growth per year in the near future), Eastern Europe (6%), and Latin America (8%). Total global growth should be about 6% per year. Growth of coatings is expected to continue at 8% per year in China, 11% in India and 4–5% in Indonesia. Growth in value terms will be even higher because of the increased production of relatively higher-valued coatings. Most of the major multinational paint producers, including PPG, Akzo Nobel, Kansai Paint, Nippon Paint, BASF, Axalta (formerly DuPont), Chugoku Marine Paint, Valspar, Sherwin-Williams, and Hempel, have production in China. The multinational producers should gain even more presence in the developing world as living standards increase and per capita consumption of coatings rises.
One new area of interest is nanotechnology, with tens of thousands of patents issued already just for the coatings industry. Very small ceramic or metallic particles can be added to paint formulations to modify specific properties (e.g., scratch, mar, wear, corrosion, and UV resistance) in highly specialized applications. The average size of nano particles is 10–70 nanometers, consisting of less than 6.5 million atoms. At these sizes, the ratio of surface area to mass becomes significant, giving the particles unique properties. For example, at 2 nanometers, the conductivity of metal particles changes and at 20 nanometers, the transparency of ceramic particles changes. At 20 nanometers, particles of gold turn red and their plasticity disappears.
Some of the futuristic applications are nanotubes for electrically conductive coatings and to increase the speed of reaction of thermosetting resins; organosilane dendrimer coatings; buckyball coatings for machine parts; and metals for conductive coatings in inks. The technology is mainly limited to highly specialized applications because of the high cost per unit volume needed to reduce the size of particles and the need to add surface modifiers to keep the particles from agglomerating. Recent research efforts have been focused primarily on functionalizing the particle surface of the nano particles to make them more compatible with the coating resin systems, so that easy dispersion, low viscosity, and covalent bonding between the particles and resins are achieved.
Through the next five years, air pollution regulations will continue to be a driving force behind the adoption of new coating technologies. Despite the relatively slow growth in demand anticipated for coatings overall, waterborne and high-solids coatings, powders, UV curables, and two-component systems appear to have good growth prospects.
In general, environmental regulations are becoming more stringent in all regions to limit emissions of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs), not only in the industrialized world, but also in developing countries like China.