Rigid polyurethane marketing

J. S. Newman, "Smoke Characteri2ation of Rigid Polyurethane/Isocyanurate Foams," 34th SPl Annual Polyurethane Technical Marketing Conference, New Orleans, La., Oct. 21—24, 1992, pp. 307—311. 

Polyester Polyols. Initially polyester polyols were the preferred raw materials for polyurethanes, but in the 1990s the less expensive polyether polyols dominate the polyurethane market. Inexpensive aromatic polyester polyols have been introduced for rigid foam appHcations. These are obtained from residues of terephthaHc acid production or by transesterification of dimethyl terephthalate (DMT) or poly(ethylene terephthalate) (PET) scrap with glycols. 

The Effects of Regulatory Actions on the Marketing of Rigid Polyurethane Foam Insulation... 

It is estimated that 615 million pounds of rigid polyurethane foam were made during 1979.(1). The market for these foamed plastics has been growing at an annual 15 percent rate for the last few years. It is projected that similar growth may resume in future years. The construction market is the key to future growth, as the greatest share of rigid polyurethane foam is used in thermal insulation applications. 

Rigid polyurethane foams have a special problem when it comes to making a fair statement about their R-values. Essentially, all of these products are expanded with chlorofluorocarbon 11 (CFC-11), which is trichlorofluoromethane. At the time of formation, all of these materials have essentially the same R-value of about 7.5 to 8.0 per inch of thickness. At one time, that is how these products were marketed. The initial thermal resistance, however, changes with time. Where the foamed plastic is exposed to air, the air migrates into the cells, diluting the chlorofluorocarbon gas. The thermal resistance decreases when this takes place. This is a slow process and may go on for years. To the extent that the foam is sandwiched between air impervious skins, the process is all but halted. 

We have already been introduced to polyurethane chemistry in Chapter 10, Section 2, where we used toluene diisocyanate (TDI) reacting with a diol to give a polyurethane. Polyurethanes derived from MDI are more rigid than those from TDI. New applications for these rigid foams are in home insulation and exterior autobody parts. The intermediate MDA is now on the Reasonably Anticipated to Be Human Carcinogens list and the effect of this action on the market for MDI remains to be seen. The TLV-TWA values for MDA and MDI are some of the lowest of the chemicals we have discussed, being 0.1 and 0.005 ppm respectively. 

The isocyanates form the major part of the hard or rigid phase of the polyurethane. The three main isocyanates used in industry for castable materials are toluene diisocyanate (TDI), 4,4 diphenylmethane diisocyanate (MDI), and 1,5-naphthalene diisocyanate(NDI). Aliphatic diisocyanates form a small segment of the diisocyanate market. 

Polyurethane rigid foam insulation also can be applied as a spray system to a variety of surfaces. Retro-fitting commercial roofs as well as insulation of tanks and pipes has had increasing acceptance. The next decade will require even further conservation of energy in all manufacturing facilities, and provide an ideal market for sprayed rigid foam insulation. By the end of this decade, the demand for spray systems could readily double the current level. 

There is also interest in using polyurethane foam for the insulation of LNG tankers. These ships use high-density rigid foam (up to 100 kg/in ) and require significant quantities per tanker. Countries with well established ship building industries are vying for this market. 

The PRC markets for polyurethanes are centered in a range of applications from conventional flexible cushioning and rigid foam insulation to more sophisticated uses, such as shoe soles, synthetic leather and gymnasium playing surfaces. While statistics are not readily available, the PRC consumes about 10 million pounds of rigid foam and 8 million pounds flexible foam annually. Recent plans to build a 3 million in per year poromeric polyurethane synthetic leather plant should give impetus to polyurethane demand in 1982/83. 

Based on the numbers in Figures 1 and 2, by 1985 RIM and RRIM will require approximately 50 M lbs. of monomeric MDI, which is about one-third of the monomeric MDI supply in 1985 (Table IX based on 20-25% of 85% nameplate capacity, excluding ARCO capacity, = 137-171 M lbs. monomeric MDI). This will leave about 100 M lbs. of monomeric MDI for cast elastomers, thermoplastic polyurethanes, shoe soles, semi-rigid foams, and some adhesives and sealants, a monomeric MDI supply which should be more than sufficient for these applications. As RRIM grows, a need for capacity expansion can be seen in the late 1980 s. No effects on the market will be seen from PUR-SMC until after 1985, and at the present time meaningful projections are impossible. 

What kind of stakes are involved A 1979 "Outlook" annual market survey by the Upjohn Company indicates that the total United States market for polyurethanes would be 2,1+1+1+ million pounds including 1,1+50 million pounds for flexible foam, 615 million for rigid foam and 379 million for elastomers, coatings and adhesives. 

Thesecompounds, widely employed at the outset of the development of polyurethanes have been displaced from their market by polyether-polyols. For the production of rigid foams however, use is still made of aromatic polyols produced by the transesterification of dimethyl terephthalate by glycoL... 

A number of "crude" isocyanates (polymeric isocyanates), undistilled grades of MDI and TDI, are available in the market. Some of these products, such as various forms of crude MDI, have a functionality varying between 2 and 3. They have a lower reactivity and a lower vapor pressure than the corresponding pure isocyanate. They have found extensive use in one-shot rigid foams. However, they are also employed in coating, sealant, and adhesive applications. The Upjohn Chemical Division has published an excellent bulletin on the use and precautions in handling isocyanates, polyurethanes, and related materials (13A). 

Foams are available as rigid sheets or slabs (which are used in the majority of roofing systems), as beads and granules (used in cavity wall insulation), and also as spray and pour-in applications. The market is dominated by polyurethane (PU) foams, in particular polyisocyanurate products, expanded polystyrene (PS), and extruded polystyrene. 

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