Published May 2014
This report covers the two main types of styrene-butadiene latexes—SB latex and SBR latex (high-solids latexes)—which are classified based on styrene content. SB latexes have a high styrene content and thus are more like a plastic, while SBR latexes have a low styrene content and are more elastomeric. In industry, SB latexes are most widely used for coated/pigmented paper and paperboard coatings and carpet backcoatings and accounted for 85–90% of worldwide styrene-butadiene latex consumption in 2013. The remaining consumption (10–15%) is for SBR latexes, which are used mostly for molded foams and adhesives. Styrene-butadiene-vinylpyridine terpolymers, which are almost exclusively used for tire cord treatments, represent a minimal portion.
The production of SB/SBR latex in the world is highly fragmented. There are more than fifty producers globally, with two market leaders—BASF and Styron/Trinseo—together controlling nearly 35% of the market. Because of the fragmentation and low overall growth in the market, it is reasonable to expect a further rationalization of the supply structure, with more capacity rationalization (including unit closures).
The following pie chart shows world consumption of SB/SBR latex:
In 2013, the level of world consumption of SB/SBR latex represented an average annual decrease of 4.3% from the level of consumption in 2007. The major world consumers of SB/SBR latexes in 2013 were Western Europe, China and North America, accounting for 70% of world consumption.
The largest application for SB latex is paper coatings. Carboxylated SB latex is the dominant synthetic pigment binder for coated papers. SB latex–based coating systems offer a high coating speed, and enhanced pigment binding power that results in smoothness, higher gloss level, brightness, opacity and water resistance at lower cost than the alternatives. About 75–80% of SB latex binders are used on coated printing papers such as magazines, annual reports, label stock, advertising flyers and catalogues. The remaining 20–25% is used for coating paperboard products (commercially produced coated paperboard) such as folding cartons for food packaging uses. SB latex improves brightness uniformity as well as print performance. In addition, it optimizes glueability, stiffness and scoring, and enhances ink and varnish performance.
SB latexes are also used in paper saturation for the production of specialty papers and board to obtain resistance to grease or petroleum, or to improve strength at high temperatures. Saturated specialty papers and board are used for book covers, gaskets, containers, masking tape and various sandpapers.
The challenges in the coated paper industry include more conservation of trees as a fiber source, greater usage of non-paper-based (internet) advertising and promotional brochures, growth of on-demand printing, greater use of recycled and secondary fibers, improvement in the weight-to-stiffness ratio, the cost of butadiene, and more environmentally friendly and efficient paper-making processes. All these challenges will continue to demand innovation in the coating and finishing sector.
The second major outlet for SB latex is in backcoatings for tufted carpets. Latex backcoatings hold the tufts in place, anchoring the pile fibers, providing improved stability and resistance to fraying or tuft loss at the cut edges of the carpets. The latex functions as the laminating adhesive for a secondary backing (primarily polypropylene), but it can also function as the actual backing on some carpets (so-called unitary back carpets). The styrene content in SB latexes varies depending on the physical features desired in the final product. Over 90% of carpets produced in the United States are tufted, and most of the carpet industry is concentrated in the southeastern states, primarily in Georgia. Accordingly, several SB latex plants are located in that region. In Western Europe, Belgium is the center of the carpet industry and accounted for 40–45% of total tufted carpet production in 2013; the Netherlands, which is the second-largest producing country, accounted for 20–25%.
Global consumption for SB/SBR latexes is forecast to grow at about 1% per year during 2013–2018.