Patent interests

The patent interest in this field " reflects the potential that industry feels for this field. By the use of physical bonds, some degree of flow potential is maintained in the materials, although some compositions boecome truly thermoset in a last curing reaction. 

Two British publications of industrial patent interest are Lapis (Kenneth Mason Publications, 167 Victoria St., London S.W.l), a monthly journal which lists products and processes for manufacture under licence, and Patex (68 Vicarage Lane, Ilford, Essex) a monthly survey of expired British chemical patents now open for use by industry. 

The applications of TPEs in the medical, surgical, and pharmaceutical activities are rapidly developing. Many references are patents, interesting... 

Once we have the measures, we have to apply them to chemical objects. Objects of interest to a chemist include molecules, reactions, mbrtures, spectra, patents, journal articles, atoms, functional groups, and complex chemical systems. Most frequently, the objects studied for similarity/dissimilarity are molecular structures. 

Recently, however, new interest has developed due to their chemotherapeutic and bacteriostatic usefulness in animal husbandry. They also have been patented as herbicides and plant-growth-regulating agents. 

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 single-step -duoroaruline [31-40-4] process based on duorodeoxygenation of nitrobenzene (via in situ generation of /V-phenylhydroxyl amine) in anhydrous hydrogen duoride (94—96) has not been commercialized primarily due to concurrent formation of aniline, as well as limited catalyst life. The potential attractiveness of this approach is evidenced by numerous patents (97—101). Concurrent interest has been shown in the two-step process based on /V-phenylhydroxylamine (HF-Bamberger reaction) (102—104). 

There is growing commercial importance and escalating scientific interest in PVDF. The World Patent database, including the United States, Hsts 678 patents that cite the term poly(vinyHdene fluoride) for the period 1963—1980 and 2052 patents for the period 1981—1992 Chemical Abstracts files covering the years 1967—1992 contain 5282 references for the same term. Thirty years ago there was only one commercial producer of PVDF in the world now there are two in the United States, two in Japan, and three in Europe. 

In the United States there was Httie interest in solvent processing of coals. A method to reduce the sulfur content of coal extracts by beating with sodium hydroxide and zinc oxide was, however, patented in 1940 (116). In the 1960s the technical feasibiHty of a coal deashing process was studied (117),... 

The use of alkaU metals for anionic polymerization of diene monomers is primarily of historical interest. A patent disclosure issued in 1911 (16) detailed the use of metallic sodium to polymerize isoprene and other dienes. Independentiy and simultaneously, the use of sodium metal to polymerize butadiene, isoprene, and 2,3-dimethyl-l,3-butadiene was described (17). Interest in alkaU metal-initiated polymerization of 1,3-dienes culminated in the discovery (18) at Firestone Tire and Rubber Co. that polymerization of neat isoprene with lithium dispersion produced high i7j -l,4-polyisoprene, similar in stmcture and properties to Hevea natural mbber (see ELASTOLffiRS,SYNTHETic-POLYisoPRENE Rubber, natural). 

The Calcimatic is a patented kiln of Canadian origin that is radically different from other kiln types. It consists of a circular traveling hearth of variable speed, supported on two concentric tiers of rollers. Kiln feed of 12.7 mm is fed onto the hearth in a 2.5—10 cm bed from a preheater chamber. The kiln is usually fired with natural gas or fuel oil, although the option of using pulverized coal has also been developed. After great interest, resulting in sales of many units throughout the world, the popularity of the Calcimatic has ebbed because of disappointment in the unit s mediocre thermal efficiency. 

The interest in 2,6-dialkylnaphthalenes such as dimethyl, diethyl, diisopropyl, dihexyl, etc, is shown by the increasing number of patents relevant to thek preparation, isomeri2ation, and separation (109—111). No method for selectively preparing 2,6-dialkylnaphthalene has to date been discovered. The efforts that have been made have each failed, not only with conventional Fridel-Crafts catalysts (106,112,113), but also with other catalysts such as... 

Once the patent appHcation is complete and the inventor has made a formal declaration of inventorship, the appHcation is filed with the U.S. PTO. In the U.S. PTO, the appHcation is the subject of a thorough, formal, and substantive examination by a patent examiner. Once the patent examiner is convinced that the patent appHcation satisfies the statutory requirements provided for under the laws of the United States, the patent appHcation will be allowed to issue as a patent. Issuance takes the form of a pubHcation provided by the U.S. Government. The pubHcation of patents occurs only on Tuesdays that ate not federal hoHdays. At the time of issuance, the patent is assigned a number and made pubHc in a form which allows all interested patties to obtain access to it. 

A new initiative introduced by Derwent during 1995 is the Patents Citation Index, an on-line database of patent citations that includes both examiners citations and patentees citations to prior art from patent specifications. When given a known invention of interest, as represented by a patent family, the database can identify any patent against which it has been cited, as well as eadier patents cited by any member of that family. Limited citation... 

Traditional paging through patent office gazettes and printed abstract bulletins stiU serves a usefiil purpose in patent alerting. It can be difficult to frame a query for a computer search on all the subject matter that might be of interest to an organization. The human mind can spot unanticipated material and relate it to interests, something presendy beyond the power of the computer. 

Most new patent cases of interest are pubHshed by at least one of the U.S., European, or Japanese patent offices, and WIPO (PCT). Japan presents problems for those not able to read Japanese, but the U.S. Official Ga tte (with representative claims) and PCT Ga tte (with English-language abstracts) can be in one s hands within a week of patent pubHcation. Similar timing is available for the European Patent Office bulletin which contains trilingual tides and the on-line EPAT file and various CD-ROM products. A highly effective alerting program can be developed from a combination of these methods. 

In 1991, Alusuisse Italia announced the constmction of a 20 x 10 t/yi" trimellitic anhydride unit at Bergamo, Italy (109) and commenced production in late 1994. A European patent appHcation (110) assigned to Alusuisse suggests that the process used is very similar to that of Amoco, that is, pseudocumene is air oxidized in the Hquid phase using heavy-metal catalysts and bromine. A number of other companies have shown interest in the production of trimellitic anhydride (111—113). 

Plasticizers for acryhcs include all common phthalates and adipates. There has been interest in the development of acryUc plastisols similar to those encountered with PVC. Clearly the same aspects of both plastisol viscosity and viscosity stabiUty are important. Patents appear in the Hterature (32) indicating that the number of available plasticizers that show both good compatibiHty with acryHc resins and satisfactory long-term plastisol stabiHty may be fewer than those showing equivalent properties with emulsion PVC resins. 

Polycarbonates are prepared commercially by two processes Schotten-Baumaim reaction of phosgene (qv) and an aromatic diol in an amine-cataly2ed interfacial condensation reaction or via base-cataly2ed transesterification of a bisphenol with a monomeric carbonate. Important products are also based on polycarbonate in blends with other materials, copolymers, branched resins, flame-retardant compositions, foams (qv), and other materials (see Flame retardants). Polycarbonate is produced globally by several companies. Total manufacture is over 1 million tons aimuaHy. Polycarbonate is also the object of academic research studies, owing to its widespread utiUty and unusual properties. Interest in polycarbonates has steadily increased since 1984. Over 4500 pubflcations and over 9000 patents have appeared on polycarbonate. Japan has issued 5654 polycarbonate patents since 1984 Europe, 1348 United States, 777 Germany, 623 France, 30 and other countries, 231. 

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