First patents

Although acrylonitrile manufacture from propylene and ammonia was first patented in 1949 (30), it was not until 1959, when Sohio developed a catalyst capable of producing acrylonitrile with high selectivity, that commercial manufacture from propylene became economically viable (1). Production improvements over the past 30 years have stemmed largely from development of several generations of increasingly more efficient catalysts. These catalysts are multicomponent mixed metal oxides mostly based on bismuth—molybdenum oxide. Other types of catalysts that have been used commercially are based on iron—antimony oxide, uranium—antimony oxide, and tellurium-molybdenum oxide. 

Tire Ya.rns, A method to iacrease the strength of viscose yam from the 0.2 N /tex (2.2 gf/den) standard to levels needed ia tires was first patented by Courtaulds ia 1935 (18). By raising the ziac concentration ia the spia bath to 4% the thread could be stretched more by immersing it ia a hot dilute acid bath duting extension. Filament strengths iacreased to about 0.3 N/tex (3.3 gf/den), and the cross section became rounder, with a thicker skin than regular viscose. Pairs of these yams were capable of beiag twisted iato tire cords which outperformed traditional cotton cords. 

The next significant strength improvement followed the 1950 Du Pont (19) discovery of monoamine and quaternary ammonium modifiers, which, when added to the viscose, prolonged the life of the ziac cellulose xanthate gel, and enabled even higher stretch levels to be used. Modifiers have proliferated siace they were first patented and the Hst now iacludes many poly(alkylene oxide) derivatives (20), polyhydroxypolyamines (21—23), and dithiocarbamates (24). 

Oxidation of methanol to formaldehyde with vanadium pentoxide catalyst was first patented in 1921 (90), followed in 1933 by a patent for an iron oxide—molybdenum oxide catalyst (91), which is stiU the choice in the 1990s. Catalysts are improved by modification with small amounts of other metal oxides (92), support on inert carriers (93), and methods of preparation (94,95) and activation (96). In 1952, the first commercial plant using an iron—molybdenum oxide catalyst was put into operation (97). It is estimated that 70% of the new formaldehyde installed capacity is the metal oxide process (98). 

Fluorescent Pigments. The first patents for daylight fluorescent products were issued in 1947 (9,10), describing fluorescent dyed cellulose acetate fabrics with several barrier coats to improve long-term stability. These fabrics were brilliantly fluorescent and were widely used during World War II as signal panels. 

Another market appHcation for naphthenic acid is the tire industry, where cobalt naphthenate is used as an adhesion promoter (see Adhesives Tire cords). Cobalt naphthenate improves the bonding of brass-plated steel cords to mbber, presumably by suppressing the de-zincification of brass (50). Its first reported use was in 1970 and the first patent for its use was issued in 1975 (51). About 900 t of cobalt naphthenate is used worldwide as an adhesion promoter, half of it in North America. The unit value fluctuates between 8.75—13.25 /kg because of the volatility of cobalt prices. Although it is the industry standard, the use of cobalt naphthenate is declining with the advent of more economical high metal-containing substitutes. 

The interference proceeding is declared by the patent examiner and occurs in the U.S. PTO. Once an interference is declared, a deterrnination is made as to the exact subject matter constituting the invention of the interference and who filed the first patent appHcation on that invention. The first appHcant becomes the senior party to the interference. The junior party has the burden of proving that it was prior in time as to its date of invention. 

The induction furnace was first patented in Italy in 1877 as a low frequency furnace. It was first commercially appHed, installed, and operated in Sweden. The first installation in the United States was made in 1914 by the American Iron and Steel Company in Lebanon, Pennsylvania however, it was not successhil. Other low frequency furnaces have been operated successhiUy, especially for stainless steel. 

In 1875, a paper by Winkler awakened interest in the contact process, first patented in 1831. Winkler claimed that successfiil conversion of SO2 to SO could only be achieved with stoichiometric, undiluted ratios of SO2 and O2. Although erroneous, this beUef was widely accepted for more than 20 years and was employed by a number of firms. Meanwhile, other German firms expended a tremendous amount of time and money on research. This culminated in 1901 with Knietsch s lecture before the German Chemical Society (3) revealing some of the investigations carried out by the Badische Anilin-iind-Soda-Fahrik. This revealed the abandonment of Winkler s theory and further described principles necessary for successfiil appHcation of the contact process. 

Bismaleimides are best defined as low molecular weight, at least diftinctional monomers or prepolymers, or mixtures thereof, that carry maleimide terminations (Eig. 3). Such maleimide end groups can undergo homopolymerization and a wide range of copolymerizations to form a highly cross-linked network. These cure reactions can be effected by the appHcation of heat and, if required, ia the presence of a suitable catalyst. The first patent for cross-linked resias obtained through the homopolymerization or copolymerization of BMI was granted to Rhc ne Poulenc, Erance, ia 1968 (13). Shordy after, a series of patents was issued on poly(amino bismaleimides) (14), which are synthesized from bismaleimide and aromatic diamines. 

Modem electroless plating began in 1944 with the rediscovery that hypophosphite could bring about nickel deposition (7,8). Subsequent work led to the first patents on commercially usable electroless nickel solutions. Although these solutions were very useful for coating metals, they could not be used on most plastics because the operating temperature was 90—100°C. The first electroless nickel solution capable of wide use on plastics was introduced in 1966 (9). This solution was usable at room temperature and was extremely stable (see Nickel and nickel alloys). 

Early records also indicate that cast mouldings were prepared from shellac by the ancient Indians. In Europe the use of sealing wax based on shellac can be traced back to the Middle Ages. The first patents for shellac mouldings were taken out in 1868. 

The first patent on the chlorination of polyethylene was taken out by ICI in 1938. In the 1940s scientists of that company carried out extensive studies on the chlorination process. The introduction of chlorine atoms onto the polyethylene backbone reduces the ability of the polymer to crystallise and the material becomes rubbery at a chlorine level of about 20%, providing the distribution of the chlorine is random. An increase in the chlorine level beyond this point, and indeed from zero chlorination, causes an increase in the Tg so that at a chlorine level of about 45% the polymer becomes stiff at room temperature. With a further increase still, the polymer becomes brittle. 

The high thermal stability of the carbon-fluorine bond has led to considerable interest in fluorine-containing polymers as heat-resistant plastics and rubbers. The first patents, taken out by IG Farben in 1934, related to polychlorotri-fluoroethylene (PCTFE) (Figure 13.1 (a)), these materials being subsequently manufactured in Germany and the United States. PCTFE has been of limited application and it was the discovery of polytetrafluoroethylene (PTFE) (Figure... 

Biphasic catalysis is not a new concept for oligomerization chemistry. On the contrary, the oligomerization of ethylene was the first commercialized example of a biphasic, catalytic reaction. The process is known under the name Shell Higher Olefins Process (SHOP) , and the first patents originate from as early as the late 1%0 s. 

The zinc chloride cell, which was first patented in 1899, IS actually an adaptation of the Leclanche cell. The major innovation was the development of plastic seals that permitted the replacement of animoliitim chloride in the electrolyte. 

Diesel began work on an economical engine as early as 1880. The following year he took out his first patents—for machines to make clear ice. Throughout the remainder of the decade he worked on an ammonia vapor engine and (less rigorously) on a solar-powered engine. In 1889 he moved to Berlin to work as Linde s representative there. In... 

Air conditioning has been another revolutionary application of electricity. The technique was first patented by William Carrier in 1902 but widespread adoption came only after I960, opciiing up first the American Sunbelt to mass migration from northern states, then increasing the appeal of subtropical and... 

Sperry applied for his first patent—a dynamo-electric machine— when he was twenty. His final patent application—for a variable pitch propeller— was submitted in 1930, shortly after his death. In total, 355 of his over 400 patent applications matured as actual granted patents. 

In 1873, an American, C. G. Cross, was issued the first patent related to a downhole turbine motor for rotating the drill bit at the bottom of a drillstring with hydraulic power [78]. This drilling concept was conceived nearly 30 years before rotary drilling was introduced in oil well drilling. Thus the concept of using a downhole motor to rotate or otherwise drive a drill bit at the bottom of a fluid conveying conduit in a deep borehole is not new. 

Two-pack epoxies These were first patented in 1938 but were not in general production until 1947. They have been very widely used over the last decade. Produced from the by-products of the petroleum industry, the basic epoxy resins may be in the form of relatively low-viscosity liquid resins or they may be solid resins of increasing hardness. Both solid and liquid resins can then be reacted with a number of different curing agents. This means that almost any type of film and with any required properties can be made. 

Many types of PAs have been studied, and in one of the first patents on PAs, filed by of Carothers of DuPont in 1937, 31 were described.1 Of these 31 polyamides,... 

The first patent of Edwards and Robinson147 claims the condensations of pyromel-litic acid and aliphatic diamine salt to prepare polyimide. Recently, that approach has been revisited, and biphenyl tetracarboxylic and pyromellitic acids give a salt monomer by reaction with 1 mol of an aliphatic diamine (octamethylene diamine and dodecamethylene diamine). The salts were polymerized under 250 MPa at 250°C for 5 h in closed reaction vessels (Fig. 5.32) giving crystalline polymers.148 By reaction of pyromellitic tetraacid with oxydianiline, it has been possible to isolate a monomeric salt. It was polymerized under 30 MPa giving a PMDA-ODA polyimide with water elimination. 

---