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Statistics in brief - Diisocyanates

Isocyanates are reactive substances. Diisocyanates have two reactive sites and react with alcohols to form polyurethanes. This reaction is called curing.

Polyurethane is a polymer used for flexible and rigid foams as upholstry in furniture, in automobile interiors and for insulating purposes.

When polyurethane is exposed to severe heating, e.g. when ironing or replacing car windows, the polyurethane is broken down to isocyanates which can be dangerous.

Turnover of diisocyanates in Sweden

Graph, Turnover of diisocyanates in Sweden.

Source: Products Register, Swedish Chemicals Agency.

The turnover of diisocyanates is around 9,000 tonnes. There are six different substances used in Sweden. The most common is toluene diisocyanate, TDI, and methylphenylmethane diisocyanate, MDI.

For occupational safety reasons prepolymerised MDI is used. Then the diisocyanate is partly polymerised before mixing and brought to final curing after application as binder in e.g. paint and adhesives. About 6,300 tonnes of prepolymerised MDI was used in 2010. 

Breakdown between different diisocyanates 2009

NameShort nameNumber of productsAmount, tonnes
Methylenediphenylene diisocyanate MDI 586 4,667
Toluene diisocyanate TDI 219 3,899
Isophorone diisocyanate IPDI 233 504
Hexamethylene diisocyanate HDI 351 4
Others   93 101

Source: Products Register, Swedish Chemicals Agency.

The use of diisocyanates in Sweden 2010

Graph, The use of diisocyanates in Sweden 2010.

Source: Products Register, Swedish Chemicals Agency.

The use of diisocyanates as raw material for production of polyurethane plastic articles account for about 90 per cent of all use. Five per cent is used as binder in adhesives. One per cent is used in different sealants and caulking products. Floor cover material is a clear polyurethane coating put on plastic carpets to enhance wearing qualities. It accounts for one per cent of use and so does insulating material.