Dominating patents

Ethylene oxide (qv) was once produced by the chlorohydrin process, but this process was slowly abandoned starting in 1937 when Union Carbide Corp. developed and commercialized the silver-catalyzed air oxidation of ethylene process patented in 1931 (67). Union Carbide Corp. is stiU. the world s largest ethylene oxide producer, but most other manufacturers Hcense either the Shell or Scientific Design process. Shell has the dominant patent position in ethylene oxide catalysts, which is the result of the development of highly effective methods of silver deposition on alumina (29), and the discovery of the importance of estabUshing precise parts per million levels of the higher alkaU metal elements on the catalyst surface (68). The most recent patents describe the addition of trace amounts of rhenium and various Group (VI) elements (69). 

Living radical polymerization currently dominates patents, publications and conferences on radical polymerization. The most popular systems, NMP, ATRP and RAFT, while offering unprecedented versatility are not without drawbacks and still have some limitations. Thus, while the progress in this field since the first edition of this book is substantial by any standard, there remains significant scope for new and improved processes. Further studies of the detailed kinetics and... 

A patent-sharing arrangement gave DuPont initial control over PET in the United States while ICI Chemicals dominated patents in the rest of the world (6-9). 

Dominating patents are those that are generally the first ones to issue and detail a novel technology. 

Nonreactive additive flame retardants dominate the flexible urethane foam field. However, auto seating appHcations exist, particularly in Europe, for a reactive polyol for flexible foams, Hoechst-Celanese ExoHt 413, a polyol mixture containing 13% P and 19.5% Cl. The patent beHeved to describe it (114) shows a reaction of ethylene oxide and a prereacted product of tris(2-chloroethyl) phosphate and polyphosphoric acid. An advantage of the reactive flame retardant is avoidance of windshield fogging, which can be caused by vapors from the more volatile additive flame retardants. 

Chemithon secured patents on a somewhat similar oleum-type continuous sulfonation and sulfation process (259,260). So-called dominant bath sulfonation processes function well because they appear to operate ia or near the homogeneous area of the phase diagram (1) and heat removal is readily controllable with relatively small iacremental reaction. 

Poly(dicyclopentadiene). The development of polydicyclopentadiene [25038-78-2] for reaction injection molding is an area which has generated much interest. The polyDCPD is obtained via metathesis polymerization of high purity (usually greater than 98%) DCPD. Excellent reviews (61—62) of the chemistry and properties of polyDCPD have been pubHshed. The patent Hterature of polyDCPD synthesis, catalysts, modifiers, and appHcations is dominated by Hercules (44 patents) and B. F. Goodrich (43 patents) in the U.S. Other participants are Orkem, SheU, Nippon Zeon, and Teijin. 

Polyamides are the second largest group of synthetic fibers after polyesters. However, they were the first synthetic fibers that appeared in the market in 1940. This was the result of the work of W. H. Carothers in USA who developed nylon 66. At about the same time nylon 6 was also developed in Germany by I. G. Farben. Both of these nylons still dominate the market for polyamides. However, due to patent restrictions and raw materials considerations, nylon 66 is most extensively produced in USA and nylon 6 is most extensively produced in Europe. 

Living radical polymerization using thiocarbonylthio RAFT agents (including dithioesters, trithiocarbonates and xanthates) was first described in a patent published in 1998.40S The first paper describing the process also appeared in 1998.1R Other patents and papers soon followed. Papers on this method, along with NMP and ATRP, now dominate the literature on radical polymerization. 

Corma, G.A., Eduardo Domine, M., Susarte, R.M., and Rey, G.F. (2002) MCM-41 type microporous materials containing titanium and their utilization as catalysts in a- pinene oxidation, Patent W00054880. 

The search for an effective non-peptide oxytocin antagonist has become a major goal of a number of pharmaceutical companies because of the poor pharmacokinetic properties and especially the lack of oral bioavailability associated with peptidic antagonists. Early research in this field was dominated by Merck, but in recent years significant research efforts at GlaxoSmithKline and Serono have been published. A number of other companies, notably Sanofi-Aventis, Yamanouchi and Wyeth, have had a major presence in vasopressin receptor research and oxytocin is frequently included in patent claims for the molecules. Occasionally, oxytocin-selective compounds have been reported, usually derived by adaptation of the vasopressin antagonist template. 

Motors support for a long-range scientific study of the poisonous gasoline additive, tetraethyl lead. Besides trouble-shooting for various Du Pont departments, Carothers published 60 papers and was listed as the inventor or coinventor of 69 U.S. patent applications during his nine years at Du Pont. Research and development were so new to American corporations that Carothers assistants drafted and he edited patent applications for Du Pont lawyers. You were supposed to be so on top of the literature that you knew whether this was something new or not.. . . Those patents are really classical scientific papers, Hill explained. Carothers considered himself unfit to be a clerk or inventor, but he dominated Du Pont s patent application process for almost a decade. 

Publications describing Btk inhibitors are scarce [39], but a recent upturn in patent activity points to intensifying medicinal chemistry efforts. The field is dominated by two classes irreversible inhibitors and reversible inhibitors which are based on an imidazopyrazine-amide scaffold (Figure 2). 

The dominant role of the batch operation over the continuous process throughout the pigment industry is somewhat in contrast to the patent literature, which includes numerous proposals for complete azo pigment manufacture by the continuous process as well as descriptions of the partial steps, such as the diazotization or the coupling reaction. 

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