Bayer polyurethane production

Among the earliest of the polyurethane products were elastomers and fibers. One fiber marketed as PERLOK was manufactured by Bayer and was the product of 1,4-butanediol and hexamethylene diisocyanate... 

Bayer AG s Bayer Material Science division (Leverkusen, Germany www.bayer.com) is building a 230 000 tpa plant in Caojing, to produce diphenyl methane diisocyanate, a raw material for polyurethane production. The plant is due on line by 2008. 

The polyurethane industry is dominated by the multinational isocyanate producers. Several of the principal isocyanate producers, including BASF, Bayer, Dow, ICI, and Olin, also manufacture polyols, the other significant building block for polyurethanes. Annual production capacities of the global aromatic isocyanate producers are Hsted in Table 11. Polyols, mainly used for flexible foam production, account for 65 wt % in a flexible foam formulation, 35% in rigid polyurethane foams, and even less in PUIR foams. 

Example 2. Two-Shot Cast Elastomer (Prepolymer Method). Synthesis of polyurethane elastomers via the prepolymer method is challenging and requires especial attention to details and techniques. This example is a relatively easy one, using a low-viscosity, 9.6% NCO MDI-based poly(tetramethylene ether) glycol prepolymer. It is adapted from the Bayer Product Information Bulletin for Baytec ME-090 prepolymer. 

Figure 22. Target product polyurethanes - All rounder among plastics. Source 3rd Carbon Dioxide Utilisation Summit. Courtesy Bayer.

The first important commercial development was a result of the work of Professor Otto Bayer in 1937, who discovered how to make a polymer using diisocyanates employing an additional polymerization technique when working on a polymer fiber to compete with nylon. Initially, the development was considered impracticable. In 1938, Rinke and associates succeeded in producing a low-viscosity melt that could be formed into fibers. This led to the production of many different types of polyurethanes. 

Polyurethanes. Polyurethanes were discovered in the thirties by Otto Bayer and have proved to be very versatile. It is possible by modifying the chemistry of the precursors to make products ranging from flexible expanded materials to hard, rigid resins—and similar scope is available also in designing polyurethanes for adhesives. 

Among the contrarians, Bayer has had for historical reasons a different approach to the problem of remaining a well-rounded producer of chemicals. It has always been a leader in such specialty chemicals as plastics and rubber additives and supplies master batches through its subsidiary Rhein Chemie. Its polymers are mainly centered on synthetic elastomers and specialty plastics like polyurethanes and polycarbonates that Bayer itself develops. These are not subjected to the cutthroat competition that commodity thermoplastics are. Bayer has remained involved in aroma chemicals with a well-known subsidiary, Haarmann Reimer. In pharmaceuticals the company occupies an honorable rank, although in the future its management may want to separate that branch from the rest of its activities in preparation for further alliances. Like BASF, Bayer considers its agrochemical line as a core business. However, unlike BASF, it is less interested in integrating upstream production to oil raw... 

The industrial production of hexamethylenediamine became important with the discovery of the use of polyamides as synthetic fibres, the most important being Nylon-6,6. This polymer, prepared from adipic acid and hexamethylenediamine, was commercialized by DuPont in 1938 and it was virtually the only consumer of the entire production of this diamine until the development of light-stable polyurethanes. Those polymers, e.g. Desmodur N (Bayer) used in paints, are based on aliphatic diisocyanates prepared from the corresponding aliphatic diamine. 

During the 1950s, a new use for aniline was in the production of the thermoplastic polyurethanes. These relied on derivatives made from either aniline or nitrotoluenes, the latter reduced to toluidines such as 106, to yield diisocyanates, typically 107 (Schemes 34 and 35). Otto Bayer at I.G. Farben had worked on polyurethane foams during World War II and details of the processes were obtained by the Allied commissions120. 

Drawing on the Allied technical reports, ICI in England began the manufacture of diisocyanates. Production of polyurethanes in the US started in 1954, and by the following year they were available on a commercial scale as adhesives, coatings, foams and elastomers. The main American manufacturers of the intermediate isocyanates were DuPont, Mobay (a joint venture of Mobil and Bayer) and National Aniline. 

A number of aliphatic isocyanates find a variety of market niches in polyurethane resin and coating components. The largest volume aliphatic isocyanate is probably hexamethylene diisocyanate (HDI 1,6-diisocyanatohexane ex. Bayer), used as an intermediate in the production of, for example, polyurethane coatings for automobile refinishing, where it is particularly favoured for its resistance to chipping. 

Bayer consolidated its American holdings at about the same time as BASF. But, given its history, it focused on a somewhat different set of product lines, especially pharmaceuticals. In 1977, partly from antitrust pressure, Bayer acquired Monsanto s 50 percent in Mobay, the joint venture that had expanded its line to polyurethane and agricultural chemicals. Bayer s primary drive, however, continued to be in pharmaceuticals. In the same year, it also purchased Cutter Laboratories, makers of nutrients and ethical drugs. Soon thereafter. Cutter recorded its first profit. Bayer s success in turning around... 

Organic isocynate [8,85,91] compounds have been known for a long time, but first became commercially interesting in the last decades based on the development work by Bayer. The reaction of di- and polyisocyanates with di- and polyols forms polyurethanes (PUR) with many uses. The preferred use of PUR in the automobile industry, in construction, and in refrigeration technology led to a considerable increase in the production capacity for feedstock diisocyanates. 

DMC catalysts are considered to be the ones that perform best at this time for PO polymerisation initiated by hydroxyl groups. Bayer developed the first continuous process, with a very high productivity, for the synthesis of polyether polyols with DMC catalysts (IMPACT Catalyst Technology). In a short and simple production cycle, a large variety of polyether diols of very low unsaturation for elastomers, sealants, coatings and low monol content polyether triols destined for flexible polyurethane foams are obtained. This is one of the best developments in the last few years in the field of polyether polyol synthesis [2],... 

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