Patents Assigned to Denka Chemical Corporation
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Patent number: 4596878Abstract: The useful life of vanadium-phosphorus-oxygen (PVO) catalyst in fixed bed reactors can be substantially extended by treatment with a phosphorus compound followed by steam treatment. The PVO catalysts may be treated with steam after long periods (months) of only phosphorus compound treatment and the benefit of the present invention obtained or the phosphorus and steam treatments may be of only a few hours duration and sequential. In extending the useful life of the PVO catalyst according to the present invention, the temperature profile in the catalyst bed is restored to substantially the same profile as the fresh catalyst.Type: GrantFiled: August 29, 1984Date of Patent: June 24, 1986Assignee: Denka Chemical CorporationInventors: Gaylon T. Click, Bruno J. Barone
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Patent number: 4565880Abstract: It has been found that phosphoric acid alone and in admixture with phenothiazine and/or methyl-p-benzoquinone reduces residue formed during the fractionation of aqueous crude maleic compositions for the production of maleic anhydride, and in particular, reduces residue due to the presence of small amounts, i.e., less than 10 ppm alkali metal ion. When the alkali metal ion is present at least 9 equivalent acid groups of phosphoric acid per atomic equivalent of alkali metal ion are present.Type: GrantFiled: June 29, 1983Date of Patent: January 21, 1986Assignee: Denka Chemical CorporationInventors: Bruno J. Barone, William G. Bowman
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Patent number: 4515899Abstract: The useful life of vanadium-phosphorus-oxygen (PVO) catalyst in fixed bed reactors can be substantially extended by treatment with a phosphorus compound followed by steam treatment. The PVO catalysts may be treated with steam after long periods (months) of only phosphorus compound treatment and the benefit of the present invention obtained or the phosphorus and steam treatments may be of only a few hours duration and sequential. In extending the useful life of the PVO catalyst according to the present invention, the temperature profile in the catalyst bed is restored to substantially the same profile as the fresh catalyst.Type: GrantFiled: December 14, 1983Date of Patent: May 7, 1985Assignee: Denka Chemical CorporationInventors: Gaylon T. Click, Bruno J. Barone
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Patent number: 4481313Abstract: A process for instantaneous peptization of chloroprene-sulfur copolymer comprising contacting a latex of said copolymer with a peptization system comprising tetraethyl thiuram disulfide and mercaptobenzothiazole.Type: GrantFiled: December 6, 1982Date of Patent: November 6, 1984Assignee: Denka Chemical CorporationInventors: Edward M. Banta, Kenneth D. Fitzgerald
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Patent number: 4283510Abstract: Addition of alkylated diarylamines to improve polychloroprene produced without using the salts of the condensation product of naphthalene sulfonic acids and formaldehyde.Type: GrantFiled: May 6, 1975Date of Patent: August 11, 1981Assignee: Denka Chemical CorporationInventor: Nathan L. Turner
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Patent number: 4283307Abstract: Phosphorus-Vanadium oxidation catalyst prepared as tablets with a hole in the center produce higher yields of maleic anhydride from C.sub.4 's, particularly n-butane than the same catalyst without the hole.Type: GrantFiled: June 2, 1980Date of Patent: August 11, 1981Assignee: Denka Chemical CorporationInventors: Bruno J. Barone, Gaylon T. Click
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Patent number: 4251390Abstract: An improvement in the oxidation catalyst used for the partial oxidation of n-butane and containing vanadium and phosphorus mixed oxides which comprises adding a zinc compound in an amount of from about 0.15 to 0.001/l Zn/V to the catalyst during the digestion of the reduced vanadium component by concentrated phosphoric acid. The addition of zinc produces a catalyst which is more easily activated and which is very stable to heat upset of the reaction system. Small amounts of lithium and silicon compounds also have additional desirable catalytic effects without dimunition of the zinc compound benefit.Type: GrantFiled: June 11, 1979Date of Patent: February 17, 1981Assignee: Denka Chemical CorporationInventor: Bruno J. Barone
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Patent number: 4250083Abstract: Viscosity stable chloroprene-sulfur copolymers are prepared by polymerizing chloroprene and sulfur in the presence of styrenated diphenyl amine. The presence of this material in the polymerization causes no discernible detriment to or degradation in the other properties of the copolymers.Type: GrantFiled: February 5, 1979Date of Patent: February 10, 1981Assignee: Denka Chemical CorporationInventors: Gaylon T. Click, Nathan L. Turner, Edwin F. Hoff, Jr.
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Patent number: 4225682Abstract: Elemental sulfur modified polychloroprene rubbers having improved Mooney viscosity stability are prepared by blending a sol and a gel in a weight ratio of sol:gel of from 98:2 to 60:40 based on solids, wherein the gel contains 0.5 to 5 weight percent of a cross-linking agent comonomer, a trihydric ester of the general formula ##STR1## wherein x is 0 or an integer of from 1 to 4 and is preferably 0; y is 0 or an integer of from 1 to 4 and preferably 1; R.sub.1, R.sub.2 and R.sub.3 represent hydrogen or an alkyl radical with from 1 to 4 carbon atoms and is preferably CH.sub.3.Type: GrantFiled: May 22, 1978Date of Patent: September 30, 1980Assignee: Denka Chemical CorporationInventor: Hubert R. O'Neal
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Patent number: 4220574Abstract: Polychloroprene compounded with corn has generally similar properties to polychloroprene compounded with aromatic oils but with superior high and low temperature properties and superior ozone resistance.Type: GrantFiled: July 10, 1978Date of Patent: September 2, 1980Assignee: Denka Chemical CorporationInventor: Rosario J. Perrone
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Patent number: 4212780Abstract: Chloroprene polymer-phenolic resin-metal oxide-solvent adhesives, which are non-phasing and which contain from about 4 to 6 parts by weight based on polymer of a rosin which must contain less than 2.16 parts by weight based on polymer of dehydroabietic acid, a constituent of rosin.Type: GrantFiled: April 24, 1978Date of Patent: July 15, 1980Assignee: Denka Chemical CorporationInventor: Kenneth D. Fitzgerald
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Patent number: 4203905Abstract: Tetrahydrophthalic anhydride for the preparation of polyesters is conveniently prepared in a stable, liquid form for transportation and storage by adding molten anhydride to a 100.degree. to 120.degree. C., C.sub.2 to C.sub.9 glycol at rate to maintain this temperature range without raising the temperature of the mixture in increments of more than 5.degree. F., reacting the mixture for a sufficient time to reduce the acid number of the mixture to a number in the range below the theoretical acid number for the half ester of the glycol and anhydride and 165; thereafter cooling the mixture to 155.degree. C., adding glycol as necessary to provide a mole ratio of glycol to anhydride in the range of 1.2 to 2:1 and cooling the mixture to a temperature in the range of 40.degree. to 70.degree. C.Type: GrantFiled: August 17, 1978Date of Patent: May 20, 1980Assignee: Denka Chemical CorporationInventor: Marvin Z. Woskow
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Patent number: 4202826Abstract: A catalyst complex useful for the partial oxidation of alkanes to the corresponding anhydrides, e.g., converting normal C.sub.4 hydrocarbons to maleic anhydrides, e.g., converting normal C.sub.4 hydrocarbons to maleic anhydride in vapor phase, comprising as components vanadium, phosphorus, oxygen, Nb. Cu, Mo, Ni, Co and Cr. Preferred are those compositions containing in addition one or more of Ce, Nd, Ba, Hf, U, Ru, Re, Li or Mg.Type: GrantFiled: April 21, 1978Date of Patent: May 13, 1980Assignee: Denka Chemical CorporationInventor: Ralph O. Kerr
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Patent number: 4179404Abstract: The preparation of phosphorus-vanadium oxidation catalyst by the reduction of the valence of vanadium to less than +5 is obtained by employing less than the stoichiometric amount of reducing agent necessary to reduce the valence of the vanadium from +5 to +4, preferably 70 to 98% of the stoichiometric amount of reducing agent can be used.Type: GrantFiled: December 15, 1976Date of Patent: December 18, 1979Assignee: Denka Chemical CorporationInventor: Bruno J. Barone
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Patent number: 4172961Abstract: An improved process for the production of 1,4-butanediol is disclosed wherein a dialkyl alkoxy succinate-containing mixture is contacted with hydrogen at elevated temperature and pressure in the presence of a copper chromite hydrogenation catalyst to form a mixture comprising 1,4-butanediol and the corresponding alkanol. In a preferred embodiment, dibutyl butoxy succinate is converted to 1,4-butanediol and n-butanol at high selectivities.Type: GrantFiled: August 8, 1975Date of Patent: October 30, 1979Assignee: Denka Chemical CorporationInventors: James D. Henery, Robert P. Arganbright
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Patent number: 4167516Abstract: A catalyst complex useful for the partial oxidation of alkanes to the corresponding anhydrides, e.g., converting normal C.sub.4 hydrocarbons to maleic anhydride in vapor phase, comprising as components vanadium, phosphorus, oxygen, Nb, Cu, Mo, Ni, Co and Cr and one or more of Y, Sm, Tb or Eu. Preferred are those compositions containing in addition one or more of Ce, Nd, Ba, Hf, U, Ru, Re, Li or Mg.Type: GrantFiled: February 27, 1978Date of Patent: September 11, 1979Assignee: Denka Chemical CorporationInventor: Ralph O. Kerr
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Patent number: 4160079Abstract: Chloroprene is polymerized in the presence of compounds of the formula ##STR1## where X, Y and Z are selected from the group consisting of oxygen and sulfur, R.sub.1 is a hydrocarbon radical having from 1 to 8 carbon atoms, R.sub.2 is a hydrocarbon radical having from 1 to 8 carbon atoms or is a radical the same as ##STR2## R.sub.3 and R.sub.4 are selected from the group consisting of hydrocarbon radicals having from 1 to 8 carbon atoms or hydrogen with at least one of R.sub.3 and R.sub.4 not being hydrogen and n is 1 to 4.Type: GrantFiled: September 9, 1977Date of Patent: July 3, 1979Assignee: Denka Chemical CorporationInventor: Morris S. Edmondson
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Patent number: 4158671Abstract: A catalyst complex useful for the partial oxidation of alkanes to the corresponding anhydrides, e.g., converting normal C.sub.4 hydrocarbons to maleic anhydride in vapor phase, comprising as components vanadium, phosphorus, oxygen, Cu, Mo, Ni, Co, Cr, Nd, Ce, Ba, Y and Sm.Type: GrantFiled: February 24, 1978Date of Patent: June 19, 1979Assignee: Denka Chemical CorporationInventor: Bruno J. Barone
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Patent number: 4153577Abstract: A catalyst complex useful for the partial oxidation of alkanes to the corresponding anhydrides, e.g., converting normal C.sub.4 hydrocarbons to maleic anhydride in vapor phase, comprising as components vanadium, phosphorus, oxygen, Cu, Mo, Ni, Co, Cr, Nd, Ce, Ba, Y and Sm.Type: GrantFiled: May 4, 1977Date of Patent: May 8, 1979Assignee: Denka Chemical CorporationInventor: Bruno J. Barone
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Patent number: RE30430Abstract: Molybdenum - vanadium - oxygen oxidation catalyst for producing maleic anhydride from benzene is regenerated and stabilized by the addition of a compound of Mo, Ni, Co, Mn or U, preferably a volatile compound, to the catalyst, after a decline in activity.Type: GrantFiled: February 26, 1979Date of Patent: November 4, 1980Assignee: Denka Chemical CorporationInventor: Ralph O. Kerr