Patents Assigned to Denka Chemical Corporation
  • Patent number: 4596878
    Abstract: 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: Grant
    Filed: August 29, 1984
    Date of Patent: June 24, 1986
    Assignee: Denka Chemical Corporation
    Inventors: Gaylon T. Click, Bruno J. Barone
  • Patent number: 4565880
    Abstract: 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: Grant
    Filed: June 29, 1983
    Date of Patent: January 21, 1986
    Assignee: Denka Chemical Corporation
    Inventors: Bruno J. Barone, William G. Bowman
  • Patent number: 4515899
    Abstract: 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: Grant
    Filed: December 14, 1983
    Date of Patent: May 7, 1985
    Assignee: Denka Chemical Corporation
    Inventors: Gaylon T. Click, Bruno J. Barone
  • Patent number: 4481313
    Abstract: 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: Grant
    Filed: December 6, 1982
    Date of Patent: November 6, 1984
    Assignee: Denka Chemical Corporation
    Inventors: Edward M. Banta, Kenneth D. Fitzgerald
  • Patent number: 4283510
    Abstract: Addition of alkylated diarylamines to improve polychloroprene produced without using the salts of the condensation product of naphthalene sulfonic acids and formaldehyde.
    Type: Grant
    Filed: May 6, 1975
    Date of Patent: August 11, 1981
    Assignee: Denka Chemical Corporation
    Inventor: Nathan L. Turner
  • Patent number: 4283307
    Abstract: 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: Grant
    Filed: June 2, 1980
    Date of Patent: August 11, 1981
    Assignee: Denka Chemical Corporation
    Inventors: Bruno J. Barone, Gaylon T. Click
  • Patent number: 4251390
    Abstract: 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: Grant
    Filed: June 11, 1979
    Date of Patent: February 17, 1981
    Assignee: Denka Chemical Corporation
    Inventor: Bruno J. Barone
  • Patent number: 4250083
    Abstract: 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: Grant
    Filed: February 5, 1979
    Date of Patent: February 10, 1981
    Assignee: Denka Chemical Corporation
    Inventors: Gaylon T. Click, Nathan L. Turner, Edwin F. Hoff, Jr.
  • Patent number: 4225682
    Abstract: 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: Grant
    Filed: May 22, 1978
    Date of Patent: September 30, 1980
    Assignee: Denka Chemical Corporation
    Inventor: Hubert R. O'Neal
  • Patent number: 4220574
    Abstract: 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: Grant
    Filed: July 10, 1978
    Date of Patent: September 2, 1980
    Assignee: Denka Chemical Corporation
    Inventor: Rosario J. Perrone
  • Patent number: 4212780
    Abstract: 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: Grant
    Filed: April 24, 1978
    Date of Patent: July 15, 1980
    Assignee: Denka Chemical Corporation
    Inventor: Kenneth D. Fitzgerald
  • Patent number: 4203905
    Abstract: 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: Grant
    Filed: August 17, 1978
    Date of Patent: May 20, 1980
    Assignee: Denka Chemical Corporation
    Inventor: Marvin Z. Woskow
  • Patent number: 4202826
    Abstract: 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: Grant
    Filed: April 21, 1978
    Date of Patent: May 13, 1980
    Assignee: Denka Chemical Corporation
    Inventor: Ralph O. Kerr
  • Patent number: 4179404
    Abstract: 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: Grant
    Filed: December 15, 1976
    Date of Patent: December 18, 1979
    Assignee: Denka Chemical Corporation
    Inventor: Bruno J. Barone
  • Patent number: 4172961
    Abstract: 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: Grant
    Filed: August 8, 1975
    Date of Patent: October 30, 1979
    Assignee: Denka Chemical Corporation
    Inventors: James D. Henery, Robert P. Arganbright
  • Patent number: 4167516
    Abstract: 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: Grant
    Filed: February 27, 1978
    Date of Patent: September 11, 1979
    Assignee: Denka Chemical Corporation
    Inventor: Ralph O. Kerr
  • Patent number: 4160079
    Abstract: 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: Grant
    Filed: September 9, 1977
    Date of Patent: July 3, 1979
    Assignee: Denka Chemical Corporation
    Inventor: Morris S. Edmondson
  • Patent number: 4158671
    Abstract: 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: Grant
    Filed: February 24, 1978
    Date of Patent: June 19, 1979
    Assignee: Denka Chemical Corporation
    Inventor: Bruno J. Barone
  • Patent number: 4153577
    Abstract: 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: Grant
    Filed: May 4, 1977
    Date of Patent: May 8, 1979
    Assignee: Denka Chemical Corporation
    Inventor: Bruno J. Barone
  • Patent number: RE30430
    Abstract: 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: Grant
    Filed: February 26, 1979
    Date of Patent: November 4, 1980
    Assignee: Denka Chemical Corporation
    Inventor: Ralph O. Kerr