Patents, early

Many other agglomeration techniques for ores and minerals were patented early in the 20th century, but, excluding sintering (Section 6.8.3), the Grbndal process was the only success until pelletization was developed and found worldwide application with an unprecedented pace (Section 6.8.1). 

The first instrument based on such a technique was patented early... 

Bird Machine applied for a patent early in 1946 on kaolin production [6]. in which decanters were included merely as items in a flowsheet, as processing tools not otherwise described, while a patent granted in 1947. but which had been filed in 1940 [7], showed a similar use in the cement industry, for classification by size. A December 1949 application by Milliken and Topping (also for Bird Machine) shows a three-section bowl, ready for solid washing on... 

The first nitration to be reported was that of beri2ene itself. Mitscher-lich in 1834 prepared nitrobenzene by treating benzene with fuming nitric acid. Not long afterwards the important method of effecting nitration with a mixture of nitric and sulphuric acids ( mixed acid ) was introduced, evidently in a patent by Mansfield the poor quality of early nitric acid was probably the reason why the method was developed. Since these beginnings, nitration has been the subject of continuous study. 

Insulation Boa.rd. The panel products known as insulation board were the earliest commodity products made from fibers or particles in the composite panel area. These are fiber-base products with a density less than 500 kg/m. Early U.S. patents were obtained in 1915 and production began soon thereafter. The initial production used wood fiber as a raw material, but later products were made of recycled paper, bagasse (sugar cane residue), and straw. Schematics of the two major processes still ia use are shown ia Figure 4. 

Phosphonium Salt—Urea Precondensate. A combination approach for producing flame-retardant cotton-synthetic blends has been developed based on the use of a phosphonium salt—urea precondensate (145). The precondensate is appUed to the blend fabric from aqueous solution. The fabric is dried, cured with ammonia gas, and then oxidized. This forms a flame-resistant polymer on and in the cotton fibers of the component. The synthetic component is then treated with either a cycUc phosphonate ester such as Antiblaze 19/ 19T, or hexabromocyclododecane. The result is a blended textile with good flame resistance. Another patent has appeared in which various modifications of the original process have been claimed (146). Although a few finishers have begun to use this process on blended textiles, it is too early to judge its impact on the industry. 

Direct Fluorination. This is a more recently developed method for the synthesis of perfluorinated compounds. In this process, fluorine gas is passed through a solution or suspension of the reactant in a nonreactive solvent such as trichlorotrifluoroethane (CFC-113). Sodium fluoride may also be present in the reaction medium to remove the coproduct hydrogen fluoride. There has been enormous interest in this area since the early 1980s resulting in numerous journal pubHcations and patents (7—9) (see Fluorine compounds, organic-direct fluorination). Direct fluorination is especially useful for the preparation of perfluoroethers. 

The first cellular synthetic plastic was an unwanted cellular phenol—formaldehyde resin produced by early workers in this field. The elimination of cell formation in these resins, as given by Baekeland in his 1909 heat and pressure patent (2), is generally considered the birth of the plastics industry. The first commercial cellular polymer was sponge mbber, introduced between 1910 and 1920 (3). 

Although lead acetate [301-04-2] is the only metallic dye used ia the early 1990s, salts or silver, copper, nickel, cobalt, bismuth, and iron have been utilized ia the past. A patent (39) refers to the use of bismuth citrate ia a solution made alkaline with triisopropan ol amine. 

Early patents indicated that because water inhibits the aldol condensation mechanism, it was necessary to dry recycle acetone to less than 1% water (139—142). More recent reports demonstrate DAA production from waste acetone containing 10—50% water (143), and enhanced DAA production over anion-exchange resins using acetone feeds that contain 3—10% water (144,145). 

Enkephalins and Endorphins. Morphine (142), an alkaloid found in opium, was first isolated in the early nineteenth century and widely used in patent medicines of that eta. It is pharmacologically potent and includes analgesic and mood altering effects. Endogenous opiates, the enkephalins, endorphins, and dynotphins were identified in the mid-1970s (3,51) (see Opioids, endogenous). Enkephalins and endorphins ate Hsted in Table 9. 

Patent laws provide for several stages in the life of an application for a patent on an invention. The pattern followed by patent laws in effect in most industrialized countries during the nineteenth and early twentieth centuries, and still in effect in the United States in 1995, calls for the examination of all patent appHcations to certify that the claimed invention meets the national standards for novelty, usehilness, and inventiveness. The owner of the technology to be patented files appHcation papers that include a specification containing a description of the invention to be patented (called the disclosure) and claims defining the limits of the invention to be protected by the patent, a formal request for the issuance of a patent, and fees. Drawings of devices and apparatuses, electrical circuits, flow charts, etc, are an important part of the disclosures of most nonchemical and many chemical patents. 

Apphcation for discovery and product patents must be made early in the process. Appropriate labels ate designed and the product is submitted to the FDA for approval to begin human testing in the form of an Investigational New Dmg Apphcation (INDA). When such approval is granted, the clinical evaluation is developed as follows. 

U.S. Laws and Regulations Related to Drug Product Development and Manufacture. Until early in the twentieth century, dmg products were made and sold in the United States having virtually no imposed control. QuaUty was generally poor. Many products were patent medicines of dubious value. Some were harmful and addicting. 

Polymerization by Transimidization Reaction. Exchange polymerization via equihbrium reactions is commonly practiced for the preparation of polyesters and polycarbonates. The two-step transimidization polymerization of polyimides was described in an early patent (65). The reaction of pyromellitic diimide with diamines in dipolar solvents resulted in poly(amic amide)s that were thermally converted to the polyimides. High molecular weight polyimides were obtained by employing a more reactive bisimide system (66). The intermediate poly(amic ethylcarboamide) was converted to the polyimide at 240°C. 

Dow Chemical Company purchased the rights to MacaHum s patents (14), initiated a detailed study of the process and other improved syntheses of PPS in the 1950s and early 1960s, and pubUshed the results of their investigation (9,15,16). Clearly, alternative routes to PPS were desirable and the most promising of these involved the nucleophilic self-condensation of cuprous -bromothiophenoxide, carried out at 200—250°C in the soHd state or in the presence of pyridine (16) ... 

Bayer marketed PPS compounds in the United States under the trade name Tedur, but the company has exited the PPS business. PPS is also marketed in the United States by GE Plastics, whose source of neat resin is Tosoh Corporation of Japan. GE Plastics markets PPS under the trade name Supec PPS. Patent activity by Tennessee Eastman describes an alternative process for the production of poly(phenylene sulfide/disulfide), although samples of such product have not appeared as of early 1996. Both Phillips and Hoechst Celanese have aimounced plans to debotdeneck their existing U.S. faciUties in order to meet anticipated market growth. 

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