Nontransition Heavy Metal Compound Is Halogen-containing Patents (Class 526/122)
  • Patent number: 4298718
    Abstract: Catalysts useful in the polymerization of olefins, more particularly of ethylene and mixtures thereof with higher alpha-olefins and/or diolefins, are disclosed. The new catalysts are obtained by mixing a hydride or organometallic compound of a metal belonging to Groups I to III of the Mendelyeev Periodic System with the product obtained by contacting a titanium tetrahalide with a support comprising an anhydrous magnesium or zinc halide in an active form, under particular conditions.
    Type: Grant
    Filed: October 14, 1975
    Date of Patent: November 3, 1981
    Assignee: Montecatini Edison S.p.A.
    Inventors: Adolfo Mayr, Paolo Galli, Ermanno Susa, Giovanni Di Drusco, Ettore Giachetti
  • Patent number: 4297462
    Abstract: For the polymerization of ethylene, as such or with one or more alpha-olefines, a novel catalyst composition is suggested, which has a high yield of polymer per weight unit of catalyst. Such compositions are prepared from a titanium compound in which the valency of Ti is 3 or more, said compound being reacted with the vapors of one or more metals of the group consisting of Al, Cr, Mn, V, Ti, Zr, Mo, Zn and Ca in the presence of a halogen donor which is preferably an organic halide, certain inorganic halides being capable of being used provided that the halide metal has at least two degrees of valency. The composition is used in association with an aluminium hydrocarbyl halide. Yields as high as 30,000 grams of polymer per gram of elemental Ti can be obtained.
    Type: Grant
    Filed: September 25, 1979
    Date of Patent: October 27, 1981
    Assignees: Snamprogetti S.p.A, Anic S.p.A
    Inventors: Margherita Corbellini, Alberto Greco, Mirko Osellame
  • Patent number: 4296223
    Abstract: The present invention comprises a catalyst system, catalyst complex, and a process for the polymerization and copolymerization of alpha-olefins in which the process is carried out in the presence of a catalyst system comprising an organic compound of a metal of Group Ib, IIa, IIIb, or IVb of the Periodic Table and a solid catalyst complex prepared by reacting a divalent metal halide, an organic oxygen compound of a metal of Group IVa, Va, or VIa of the Periodic Table, and an aluminum halide.
    Type: Grant
    Filed: October 8, 1980
    Date of Patent: October 20, 1981
    Assignee: Solvay & Cie
    Inventor: Eugene Berger
  • Patent number: 4287091
    Abstract: Polymerization, catalysts, and preparation thereof comprising milling magnesium metal, an organic halide, and titanium tetrahalide or the milled product in the presence of at least one of magnesium oxide, a triaryl phosphite, a polymeric material, titanium tetrahalide, vanadium tetrahalide, silicon tetrahalide, and an aluminum trihalide. The milled catalyst component can be heat treated prior to activation. The milled titanium catalyst component is activated with an organoaluminum activator producing a catalyst for olefin polymerization.
    Type: Grant
    Filed: August 3, 1979
    Date of Patent: September 1, 1981
    Assignee: Phillips Petroleum Co.
    Inventor: Charles M. Selman
  • Patent number: 4287328
    Abstract: A method for producing .alpha.-olefin polymers is provided. According to this method, particularly the catalyst stability is improved, resulting in polymers having a higher crystallinity, a narrower range of molecular weight, improved shape of polymer particles with a higher yield per a solid product component and per a transition metal component of the catalyst. Said catalyst is obtained by reacting a trivalent metal halide with a hydroxide, an oxide, a carbonate of a divalent metal, a double compound containing any of these compounds or a hydrate of a compound containing a divalent metal to form a solid product (I); reacting said solid product with one or more electron donors and one or more electron acceptors separately or simultaneously each in one to 10 steps but using TiCl.sub.
    Type: Grant
    Filed: March 21, 1979
    Date of Patent: September 1, 1981
    Assignee: Chisso Corporation
    Inventors: Kazutsune Kikuta, Masami Tachibana, Akihiro Sato
  • Patent number: 4277589
    Abstract: There are disclosed new solid catalyst-forming components for use in preparing catalysts for the stereoregular polymerization of alpha-olefins containing at least 3 carbon atoms, mixtures of alpha-olefins with one another and/or with ethylene, said components being obtained by reacting(a) at least one hydrocarbon-soluble halogenated Ti compound;(b) a product comprising a Mg dihalide obtained by decomposition of an adduct of at least a Mg dihalide and an electron-donor compound present in the adduct in an amount of at least 0.5 mole per mole of Mg dihalide, the decomposition product being characterized in that, in its X-rays powder spectrum, instead of the diffraction line of maximum intensity which appears in the X-rays powder spectrum of the normal Mg dihalide, a halo appears whose intensity maximum is shifted with respect to said line, and(c) an electron-donor compound which does not contain active hydrogen atoms.
    Type: Grant
    Filed: December 21, 1979
    Date of Patent: July 7, 1981
    Assignees: Montedison S.p.A., Mitsui Petrochemical Industries, Ltd.
    Inventors: Umberto Giannini, Enrico Albizzati, Sandro Parodi
  • Patent number: 4260707
    Abstract: A catalyst comprising(a) a reaction mixture formed by reacting M(RCO.sub.2).sub.3 with AlR.sub.3.sup.1,(b) AlR.sub.3.sup.2 and/or HAlR.sub.2.sup.2 and(c) a Lewis acidwherein M denotes a trivalent rare earth element with an atomic number of 57 to 71, R denotes a saturated or unsaturated, straight chain or branched chain alkyl group having 1 to 20 C-atoms which may be substituted one or more times with cycloalkyl having 5 to 7-atoms and/or phenyl, the carboxyl group being attached to a primary, secondary or tertiary C-atom; a cycloalkyl group having 5 to 7 ring carbon atoms, which may be substituted one or more times with alkyl groups having from 1 to 5 C-atoms; or an aromatic group having from 6 to 10 ring carbon atoms, which may be substituted one or more times with alkyl groups having 1 to 5 C-atoms, and R.sup.1 and R.sup.2 are identical or different, straight chain or branched chain alkyl groups having from 1 to 10 C-atoms. Said catalyst may be used for polymerizing diene monomers in solution.
    Type: Grant
    Filed: February 1, 1980
    Date of Patent: April 7, 1981
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerd Sylvester, Josef Witte, Gunter Marwede
  • Patent number: 4250285
    Abstract: A process for preparing a polymer or copolymer of an olefin having at least 3 carbon atoms which comprises polymerizing or copolymerizing an olefin having at least 3 carbon atoms and containing 0 to 10 mole % of another olefin or diolefin in the presence of a catalyst composed of (i) a solid titanium catalyst component and (ii) an organoaluminum compound; wherein the solid titanium catalyst component is obtained by contacting(1) a magnesium containing copulverization product comprising (A) an aluminum or germanium compound selected from the group consisting of aluminum compounds of the formula AlR.sub.n X.sub.3-n wherein R is a hydrogen atom, or an alkyl, alkenyl, aryl, alkoxy, aryloxy or acyloxy group optionally having a substituent, X is a halogen atom, and O<n.ltoreq.3, and germanium compounds of the formula GeR.sub.m X.sub.4-m wherein R and X are as defined above, and 0.ltoreq.m.ltoreq.
    Type: Grant
    Filed: May 4, 1978
    Date of Patent: February 10, 1981
    Assignee: Mitsui Petrochemical Industries Ltd.
    Inventors: Syuji Minami, Akinori Toyota, Norio Kashiwa
  • Patent number: 4250284
    Abstract: Polymerization and copolymerization is carried out in the presence of an improved transition metal based catalyst. The catalyst is obtained by activating with an organometallic compound, the solid product which results from the reaction of a halogen containing transition metal compound with an alkoxy metal compound of the formula X.sub.m-n M(OR).sub.n wherein M is at least one metal selected from the elements of Groups Ia, IIa, IIb, IIIa and VIIb of the Periodic Table, X is a monovalent inorganic radical, R is a monovalent hydrocarbon radical, m is the valence of M and n is an integer such that 1 .ltoreq. n .ltoreq. m.
    Type: Grant
    Filed: February 24, 1975
    Date of Patent: February 10, 1981
    Assignee: Solvay & Cie
    Inventors: Andre Delbouille, Jean L. Derroitte
  • Patent number: 4243785
    Abstract: .alpha.-Olefins are polymerized by conducting the polymerization in the presence of a catalyst prepared by reacting tetravalent or trivalent titanium compounds such as a titanium tetralkoxide, an anhydrous nickel compound such as nickel chloride, an organomagnesium component such as a hydrocarbon soluble complex of dialkyl magnesium and an alkyl aluminum and a halide source such as a hydrogen halide or an alkyl aluminum halide. Polymerization processes employing this catalyst composition do not require conventional catalyst removal steps in order to provide polymers having suitable color and other physical characteristics and these catalysts produce polymers having broader molecular weight distributions than do corresponding catalysts without the anhydrous nickel compound.
    Type: Grant
    Filed: September 5, 1978
    Date of Patent: January 6, 1981
    Assignee: The Dow Chemical Company
    Inventors: Donald F. Birkelbach, George W. Knight
  • Patent number: 4238355
    Abstract: Compositions exhibiting high catalytic activity in the polymerization of .alpha.-olefins, particularly higher olefins, are prepared by reacting tetravalent or trivalent titanium compounds such as a titanium tetraalkoxide, an anhydrous zinc compound such as diethyl zinc, an organomagnesium component such as a hydrocarbon soluble complex of dialkyl magnesium and an alkyl aluminum and a halide source such as a hydrogen halide or an alkyl aluminum halide and an aluminum compound if the halide source of organomagnesium component does not contain sufficient quantities of aluminum. Polymerization processes employing this catalyst composition do not require conventional catalyst removal steps in order to provide polymers having suitable color and other physical characteristics and these catalysts produce polymers having broader molecular weight distributions than do corresponding catalysts without the anhydrous zinc compound.
    Type: Grant
    Filed: September 10, 1979
    Date of Patent: December 9, 1980
    Assignee: The Dow Chemical Company
    Inventors: Randall S. Shipley, Donald F. Birkelbach, Kirby Lowery, Jr.
  • Patent number: 4237254
    Abstract: A process for producing olefin polymers comprising contacting an ethylenically unsaturated monomer comprising at least one olefin monomer with a catalyst system comprising a combination of a catalyst component I and a catalyst component II as described hereunder:Catalyst component IA solid product obtained by contacting the following constituents (a), (b) and (c) or (a), (b), (c) and (d) together:(a) A solid reaction product of a magnesium compound containing a hydroxyl group attached to magnesium and an organoaluminum compound represented by the formula R.sub.n AlX.sub.3-n wherein R represents a hydrocarbon residue having from 1 to 20 carbon atoms, X represents a halogen atom and n represents a number of greater than zero but not greater than 1.5, i.e. 0<n.ltoreq.1.
    Type: Grant
    Filed: April 25, 1978
    Date of Patent: December 2, 1980
    Assignee: Mitsubishi Petrochemical Company Limited
    Inventors: Sadao Kitagawa, Isao Okada, Teruo Saito, Shoichi Masukawa, Yoshihisa Watanabe, Makoto Imanari
  • Patent number: 4232138
    Abstract: A high activity catalyst component, useful in polymerizing ethylene and mixtures of ethylene and terminal olefins having eight or fewer carbon atoms, is prepared by reacting a Group II metal hydroxide with antimony pentachloride followed by reactions with a Group IVB or VB transition metal compound and an aluminum halide.
    Type: Grant
    Filed: December 19, 1977
    Date of Patent: November 4, 1980
    Assignee: Standard Oil Company (Indiana)
    Inventor: David E. Boone
  • Patent number: 4225460
    Abstract: Microcapsules with liquid fills containing Lewis acid catalysts, catalyst concentrates comprising slurries of the microcapsules in liquid media and a method for preparing the microcapsules and concentrates.
    Type: Grant
    Filed: June 28, 1979
    Date of Patent: September 30, 1980
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Richard G. Newell
  • Patent number: 4223117
    Abstract: A process for the polymerization of olefins in the presence of a catalyst comprising a titanium compound and/or vanadium compound supported on a solid carrier and an organoaluminum compound, characterized in that said solid carrier comprises a solid product obtained by the reaction of an organomagnesium compound or a reaction mixture resulting from the organomagnesium compound and at least one compound selected from the group consisting of magnesium hydroxide, calcium hydroxide, zinc hydroxide and aluminum hydroxide, with an aluminum halogenide and/or silicon halogenide, whereby there are produced olefine polymers in an extremely large amount per unit weight of catalyst.
    Type: Grant
    Filed: April 10, 1978
    Date of Patent: September 16, 1980
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Takezo Sano, Akio Kobayashi, Yasuharu Yamada
  • Patent number: 4204981
    Abstract: Ziegler catalytic system for the polymerization of olefins, formed by the combination of an organo-metallic compound and a compound of a heavy metal supported on a carrier.The carrier is an active complex obtained by reacting one or more alloys of metals chosen from Mg, Fe, Al, Ni, Cr and Zn, gaseous hydrogen chloride and one or more alcohols in the liquid or gaseous state, at a temperature of from 60.degree. to 300.degree. C., the said active complex having a content of free alcoholic hydroxyl groups of from 1 to 20% by weight, a chlorine content of from 15 to 70% by weight, a metal content of from 5 to 35% by weight, a porosity of from 0.1 to 1 cc/g and a surface area of from 1 to 200 m.sup.2 /g.
    Type: Grant
    Filed: September 29, 1978
    Date of Patent: May 27, 1980
    Assignee: Euteco S.p.A.
    Inventors: Renzo Invernizzi, Ferdinando Ligorati, Maurizio Fontanesi
  • Patent number: 4196097
    Abstract: A Ziegler catalytic system comprising an organometallic compound of a metal of Groups I to III of the Periodic Table and a compound of a heavy metal of Groups IV to VI supported on a carrier, the latter being an activated amorphous alumina or alumino-silicate containing from 0.3 to 30% by weight of salts of metals of Groups IIb, IIIa, VIb and VIII with oxygenated inorganic anions, or of a mixture of the latter with salts of said metals of Groups IIb, IIIa, VIb and VIII with non-oxygenated inorganic anions, said salts being introduced into the carrier by contacting the latter with one or more solutions of said salts and the carrier being then activated by calcination at 250.degree.-700.degree. C.
    Type: Grant
    Filed: October 6, 1977
    Date of Patent: April 1, 1980
    Assignee: Euteco S.p.A.
    Inventors: Ferdinando Ligorati, Renzo Invernizzi, Carlo Collu, Maurizio Fontanesi
  • Patent number: 4174429
    Abstract: New catalysts for the polymerization and copolymerization of olefins are disclosed. The catalysts are prepared from (1) a new class of metal compounds containing at least one atom of Mg, Mn or Ca and at least one atom of Ti, V or Zr and (2) organometallic compounds of metals belonging to one of Groups I to III of the Mendelyeev Periodic Table.
    Type: Grant
    Filed: August 23, 1978
    Date of Patent: November 13, 1979
    Assignee: Montedison S.p.A.
    Inventors: Umberto Giannini, Enrico Albizzati, Sandro Parodi, Franco Pirinoli
  • Patent number: 4168361
    Abstract: A random copolymer consisting essentially of 40 to 90 mole% of propylene and 60 to 10 mole% of 1-butene, and having (A) a boiling n-heptane-insoluble content of not more than 5% by weight based on the weight of the copolymer, (B) a boiling methyl acetate-soluble content of not more than 2% by weight based on the weight of the copolymer, (C) a melting point, determined by differential thermal analysis, of 40 to 140.degree. C., (D) an intrinsic viscosity, determined in decalin at 135.degree. C., of 0.5 to 6 dl/g, (E) an elongation at break, measured by JIS K6301, of at least 300%, (F) a tensile strength at break, measured by JIS K6301, of at least 50 kg/cm.sup.2, and (G) a haze, measured by JIS K6714, of not more than 40%.
    Type: Grant
    Filed: December 19, 1977
    Date of Patent: September 18, 1979
    Assignee: Mitsui Petrochemical Industries, Ltd.
    Inventors: Hidekuni Oda, Yozo Yamamoto, Hirokazu Kajiura, Syuji Minami, Takao Ohno
  • Patent number: 4145497
    Abstract: Uranium-containing mixed catalysts containing uranium in the formal oxidation state +4 as uranium salts of carboxylic acids, a Lewis acid, and an organometallic aluminum compound are prepared and can be used for stereospecific polymerization of diolefins or mixtures of diolefins and monoolefins.
    Type: Grant
    Filed: May 31, 1977
    Date of Patent: March 20, 1979
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerd Sylvester, Josef Witte, Gunter Marwede
  • Patent number: 4144390
    Abstract: This invention relates to the polymerization of .alpha.-olefins and to catalysts and cocatalysts for that purpose wherein the polymerization is carried out in the presence of a catalyst comprising an organometallic compound of a metal of Groups Ia, IIa, IIb, IIIa, and IVa of the Periodic Table and a solid cocatalyst comprising the reaction product of a halogenating agent, an organic oxygenated compound of a divalent metal, and a derivative of a transition metal of Groups IVb, Vb, and VIb of the Periodic Table, the proportions of halogenating agent and organic oxygenated compound being that required to result in a reaction product thereof having an atomic ratio of halogen/divalent metal greater than 1. The invention also comprises the method of making the cocatalysts.
    Type: Grant
    Filed: October 1, 1971
    Date of Patent: March 13, 1979
    Assignee: Solvay & Cie
    Inventors: Jean-Louis Derroitte, Andre Delbouille
  • Patent number: 4127710
    Abstract: A 1,3-cyclodiene comonomer and a linear conjugated diene comonomer are copolymerized employing a catalyst formed from a mixture comprising a triorganoaluminum compound, a nickel (II) compound and a Friedel-Crafts type cocatalyst. Also, a catalyst and a method for the production thereof which is useful in the copolymerization is provided.
    Type: Grant
    Filed: October 2, 1974
    Date of Patent: November 28, 1978
    Assignee: Phillips Petroleum Company
    Inventor: Henry L. Hsieh
  • Patent number: 4098907
    Abstract: A method of preparing reformed titanium trichloride catalyst for .alpha.-olefin polymerization which comprises simultaneously pulverizing an organoaluminum compound and a crystalline titanium trichloride compound, the latter comprising titanium trichloride and aluminum trichloride, subsequently treating the pulverized mixture with a solvent selected from oxygen-containing organic compounds, and finally treating the thus treated titanium trichloride with a halide of a metal selected from the groups IV and V of the periodic table.
    Type: Grant
    Filed: December 9, 1976
    Date of Patent: July 4, 1978
    Assignee: Toyo Stauffer Chemical Co., Ltd.
    Inventors: Shoichi Tokunaga, Atsumi Kato, Yoshikazu Takahashi, Kiyoshi Yamane
  • Patent number: 4085276
    Abstract: Highly stereoregular polymers or copolymers of .alpha.-olefins containing at least 3 carbon atoms are prepared in high yields by polymerizing or copolymerizing the .alpha.-olefins in the presence of a catalyst composed of (a) an improved solid transition metal catalyst component prepared by reacting (1) a magnesium-containing reaction product derived from a member of the group consisting of (i) a magnesium halide, (ii) an active hydrogen-containing compound, (iii) an organic acid ester and (iv) a silicon or tin compound containing at least one halogen atom or hydrocarbon group bonded directly to silicon or tin with (2) a titanium compound, and (b) an organometallic compound of a metal selected from aluminum, magnesium and zinc.
    Type: Grant
    Filed: February 10, 1976
    Date of Patent: April 18, 1978
    Assignee: Mitsui Petrochemical Industries Ltd.
    Inventors: Akinori Toyota, Kiyoshi Odawara, Norio Kashiwa
  • Patent number: 4071672
    Abstract: In a process for polymerizing or copolymerizing olefins in the presence of a catalyst composed of (a) a transition metal catalyst component prepared by reacting a titanium or vanadium compound and a solid carrier of a magnesium compound and (b) an organometallic compound catalyst component of a metal of groups I to III of the periodic table; the improvement wherein said transition metal catalyst component is a reaction product of a solid carrier which is an adduct formed between a magnesium dihalide and an electron donor, a compound of Si or Sn selected from the group consisting of their halogen and organohalogen compounds and a titanium or vanadium compound.
    Type: Grant
    Filed: July 28, 1975
    Date of Patent: January 31, 1978
    Assignee: Mitsui Petrochemical Industries Ltd.
    Inventor: Norio Kashiwa
  • Patent number: 4057680
    Abstract: In the method of polymerizing .alpha.-olefins by contacting an .alpha.-olefin under polymerization conditions with a stereospecific catalyst comprising a titanium trichloride component and an organoaluminium compound, the improvement wherein said titanium trichloride component is ground during or after contact with a treating agent, said treating agent being selected from at least one ofA. an alkylene oxide, andB. a lactone.
    Type: Grant
    Filed: August 10, 1976
    Date of Patent: November 8, 1977
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Isamu Yamazaki, Yoichi Toyama, Kiwami Hirota, Hisashi Takeuchi
  • Patent number: 4004071
    Abstract: Polyethylene or copolymers of ethylene with another .alpha.-olefin can be produced by the use of a novel polymerization catalyst obtained by using, in combination, (A) a specified, hydrocarbon-insoluble solid component prepared by reacting (i) a specific, hydrocarbon-soluble organoaluminum-magnesium complex (Al.sub.n Mg.sub.m R.sub.n(3.sub.-.sub..alpha.).sup.1 -R.sub.2m.sup.2 H.sub.n, wherein R.sup.1 and R.sup.2 are hydrocarbon radicals) with (ii) a titanium or vanadium compound containing halogen atom(s), and (B) an organoaluminum compound. This catalyst exhibits a surprisingly high activity per the unit amount of the solid component.
    Type: Grant
    Filed: April 17, 1975
    Date of Patent: January 18, 1977
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Itsuho Aishima, Hisaya Sakurai, Yukichi Takashi, Hideo Morita, Tadashi Ikegami, Toshio Sato
  • Patent number: 3989878
    Abstract: A process for polymerizing ethylene or a mixture of ethylene and another olefin is proposed in which the polymerization can be carried out with an extremely high efficiency by using a catalyst prepared by reacting (A) a hydrocarbon-insoluble reaction product (obtained by reacting (i) a specified organomagnesium-containing hydrocarbon-soluble complex, or reaction product of (i), with (ii) a specified siloxane compound and with (iii) at least one kind of titanium or vanadium compound containing at least one halogen atom), with (B) a specified organoaluminum compound. Resultant polymers have a high molecular weight and a high rigidity and molecular weight and molecular weight distribution thereof can be easily controlled.
    Type: Grant
    Filed: May 21, 1975
    Date of Patent: November 2, 1976
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Itsuho Aishima, Hisaya Sakurai, Yukichi Takashi, Hideo Morita, Tadashi Ikegami, Toshio Sato
  • Patent number: 3987233
    Abstract: In a method for producing a polymer or a copolymer of ethylene carried out in the presence of a catalyst obtained by a combination of a solid product containing a transition metal of the fourth a or fifth a group and an organoaluminum compound, an improvement has been made to provide a catalyst having such an efficiency as being capable of omitting ash-removal step and providing a high production yield of polymer per unit volume of polymerization vessel per hour and a polymer having a high B.D. Said catalyst can be obtained by (1) reacting a halide of trivalent metal (A) with a divalent metal compound or its derivative (B) such as hydroxide, oxide or carbonate thereof, or hydrate of these, to produce a solid product (I); (2) reacting said solid product (I) with a chain or cyclic polysiloxane having a general formula of ##EQU1## WHEREIN R.sub.1 and R.sub.
    Type: Grant
    Filed: April 29, 1975
    Date of Patent: October 19, 1976
    Assignee: Chisso Corporation
    Inventors: Akihiro Sato, Hiroshi Shimizu, Atsuyuki Kachi
  • Patent number: 3954909
    Abstract: A method for producing solid polymers having a molecular weight greater than 50,000 from olefins wherein the olefin is polymerized in the absence of a liquid dispersion agent of a nature different from that of the olefin to be polymerized, and in contact with a prepolymer containing a small amount of transition metal of subgroups IV-b, V-b and VI-b having been produced by the polymerization of an olefin in a dispersion liquid containing a Ziegler-type catalyst.
    Type: Grant
    Filed: July 16, 1973
    Date of Patent: May 4, 1976
    Assignee: Naphtachimie
    Inventors: Lazlo J. Havas, Pierre M. Mangin