Patents Represented by Attorney James F. Tao
  • Patent number: 4997638
    Abstract: Disclosed is a method of making hexametaphosphates by reacting sodium tripolyphosphate, tetrasodium pyrophosphate, or trisodium phosphate with phosphoric acid, forming a molten glass of said mixture, and chilling said molten glass to form a solid.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: March 5, 1991
    Assignee: Occidental Chemical Corporation
    Inventor: Harry E. Buckholtz
  • Patent number: 4996278
    Abstract: Substantially fully imidized polyimidesiloxanes which are based on a selected pyridine compound are soluble in diglyme which gives them particular utility in the micro-electronics industry. The polymers are prepared from the dianhydride, a difunctional siloxane monomer and an organic diamine that has the formula ##STR1## wherein X is hydrogen, halogen, phenyl or combinations thereof,Z=--O--, --S--, ##STR2## >C(CX.sub.3).sub.2, --or --Y--Ar--Y--, Ar' is an aromatic radical of 6 to 10 carbon atoms, ##STR3## Y=--O--, --S--, ##STR4## >C(CX.sub.3).sub.2, or --. n=0 or 1.
    Type: Grant
    Filed: February 7, 1989
    Date of Patent: February 26, 1991
    Assignee: Occidental Chemical Corporation
    Inventor: Chung J. Lee
  • Patent number: 4994248
    Abstract: Disclosed is an improved process for purifying phosphoric acid where a calcium sulfate hemihydrate slurry is first filtered to produce a first filtrate and a filter cake which comprises calcium sulfate hemihydrate, the calcium sulfate hemihydrate filter cake is slurried to produce a slurry containing less than 2% by weight free sulfate ion, which is hydrated in a hydration tank to produce a calcium sulfate dihydrate slurry, and the calcium sulfate dihydrate slurry is filtered on a second filter to produce a second filtrate and a gypsum filter cake. The improvement comprises recycling the second filtrate to the second filter in an amount (1) sufficient to reduce the flow rate of the calcium dihydrate slurry from the hydration tank to the second filter so that the residence time of the slurry in the hydration tank is at least two hours and (2) at least sufficient to maintain liquid on the second filter. Also disclosed is an apparatus for performing this process.
    Type: Grant
    Filed: June 5, 1989
    Date of Patent: February 19, 1991
    Assignee: Occidental Chemical Corporation
    Inventors: S. W. Slater, S. R. Hylkema, L. J. Klein
  • Patent number: 4994606
    Abstract: 4,5-Difluoroanthranilic acid may be prepared by decarboxylating 4,5-difluorophthalic anhydride or 4,5-difluorophthalic acid by heating in dimethyl acetamide, N-methyl-2-pyrrolidone or quinoline, optionally by reaction with copper, copper oxide, copper salts, or halides and salts of Zn, Cd, Ag and Ni as a catalyst, whereby 3,4-difluorobenzoic acid is formed; nitrating said 3,4-difluorobenzoic acid in a mixture of nitric and sulfuric acids to form 2-nitro-4,5-difluorobenzoic acid, and reducing said 2-nitro-4,5-difluorobenzoic acid to form 4,5-difluoroanthranilic acid.
    Type: Grant
    Filed: June 4, 1990
    Date of Patent: February 19, 1991
    Assignee: Occidental Chemical Corporation
    Inventors: Lawrence B. Fertel, Henry C. Lin
  • Patent number: 4990674
    Abstract: Disclosed is a method of making an aliphatic aromatic phosphine oxide by reacting an aliphatic aromatic phosphinic acid with a halogenating agent to produce a phosphoryl halide, reducing the phosphoryl halide to a phosphinous halide, hydrolyzing the phosphinous halide with water to produce a mixture of a phosphine and a phosphine oxide, determining how much phosphine is present in said mixture, and adding sufficient oxidizing agent to oxidize the phosphine in the mixture to the corresponding phosphine oxide. Octylphenyl phosphine oxide is preferred. The phosphine oxides are useful in making extractants for extracting actimides and lanthanides.
    Type: Grant
    Filed: June 14, 1989
    Date of Patent: February 5, 1991
    Assignee: Occidental Chemical Corporation
    Inventor: Mohan S. Saran
  • Patent number: 4990670
    Abstract: Disclosed is a method of making 1,1'-oxybis (3-nitro-5-trifluoromethyl)-benzene by heating a nitro benzofluoride compound having the formula ##STR1## where "X" is selected from the group consisting of NO.sub.2, Cl, and F, with an alkali metal fluoride selected from the group consisting of potassium fluoride, cesium fluoride, and mixtures thereof, in an organic solvent in the presence of water. The corresponding diamine, 5,5'-oxybis (3-trifluoromethyl)-benzamine, can be prepared by reducing the benzene compound.
    Type: Grant
    Filed: August 17, 1989
    Date of Patent: February 5, 1991
    Assignee: Occidental Chemical Corporation
    Inventors: Jeffrey S. Stults, Henry C. Lin
  • Patent number: 4981999
    Abstract: Disclosed is a method of selectively removing chlorine atoms in the order of fifth position first, fourth position second, and third position third from a chlorophthalic compound having at least two ring chlorine atoms such as a chlorophthalic acid or a chlorophthalic anhydride. The chlorophthalic compound is reacted in solution with a hydrodechlorinating metal in the presence of a base.
    Type: Grant
    Filed: November 20, 1989
    Date of Patent: January 1, 1991
    Assignee: Occidental Chemical Corporation
    Inventors: Neil J. O'Reilly, William S. Derwin, Henry C. Lin
  • Patent number: 4978798
    Abstract: Disclosed is a method of making a bisphenyl dihalomethane by reacting a trihalomethylbenzene with a halobenzene and a Lewis acid. The bisphenyl dihalomethane can than be reacted with water to form a halobenzophenone. In an optical third step ring chlorines that are present can be replaced with fluorines and, in a final step, any remaining chlorines can be removed to leave a fluorobenzophenone. The process is particularly useful in making 4,4'-difluorobenzophenone, which is in turn useful in making polyetheretherketones.
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: December 18, 1990
    Assignee: Occidental Chemical Corporation
    Inventor: Jeffrey S. Stults
  • Patent number: 4978760
    Abstract: A process for the preparation of halogen substituted phthalic anhydrides of the formula: ##STR1## wherein x is a halogen, by the reaction of a halogen substituted tetrahydrophthalic phthalic anhydride of the formula ##STR2## or a geminal dihalogen substituted hexahydrophthalic anhydride of the formula ##STR3## in a vapor or liquid phase while mixed with an air flow and an activated carbon catalyst at an elevated temperature.
    Type: Grant
    Filed: February 24, 1988
    Date of Patent: December 18, 1990
    Assignee: Occidental Chemical Corporation
    Inventor: Ronald F. Spohn
  • Patent number: 4975323
    Abstract: The conductivity of ground ferrophosphorus particles is increased by contacting the particles with an aqueous solution of hypophosphorus acid, preferably at a temperature between room temperature and about 50.degree.C. The particles are then washed and dried and can be mixed with resinous binders to formulate coating compositions. The coating compositions are particularly useful for coating galvanized steel that is to be welded.
    Type: Grant
    Filed: August 28, 1989
    Date of Patent: December 4, 1990
    Assignee: Occidental Chemical Corporation
    Inventor: Donald H. Campbell
  • Patent number: 4973645
    Abstract: Fully imidized polyimidisiloxanes which are based on oxydiphthalic anhydride are soluble in diglyme which gives them particular utility in the micro-electronics industry. The polymers are prepared from oxydiphthalic anhydride, a difunctional siloxane monomer and an organic diamine that provides an assymetrical structure in the polyimidesiloxane polymer chain. The polyimide-siloxane can be prepared with functional groups which render them directly curable. The polyimidesiloxanes can also be prepared with functional groups which when reacted with an unsaturated compound renders the polymers curable. The products of the invention can be used in the form of solutions in the micro-electronic industry. The polymers can also be used in wire and cable coating and to prepare films, fibers, and molded and extruded articles.
    Type: Grant
    Filed: September 1, 1988
    Date of Patent: November 27, 1990
    Assignee: Occidental Chemical Corporation
    Inventor: Chung J. Lee
  • Patent number: 4968830
    Abstract: Halogen substituted aromatic compounds of the formula ##STR1## wherein Y is selected from the group CO.sub.2 H, COF, COCl, COBr, CF.sub.3, CN, NCO, or F, and X and X' are independently hydrogen or a halogen selected from the group F-, Cl- and Br-, at least one of X and X' being halogen; may be prepared by the liquid phase reaction of a brominating agent, at temperatures below about 190.degree. Celsius, with a correspondingly substituted cyclohexene or cyclohexadiene.
    Type: Grant
    Filed: September 11, 1989
    Date of Patent: November 6, 1990
    Assignee: Occidental Chemical Corporation
    Inventor: David Y. Tang
  • Patent number: 4967838
    Abstract: Disclosed is a method of preventing fluids in the ground from rising around an oil well pipe by filling the space around the pipe with an oil well completion fluid comprising water, about 50 to about 65% by weight, based on total fluid weight, of dipotassium phosphate, and at least about 10 ppm hexavalent chromium. The fluid can be prepared by neutralizing wet process phosphoric acid with potassium hydroxide to a pH of less than 12 and filtering off any solids. Also disclosed is an oil well employing the completion fluid.
    Type: Grant
    Filed: September 14, 1989
    Date of Patent: November 6, 1990
    Assignee: Occidental Chemical Corporation
    Inventor: Harry E. Buckholtz
  • Patent number: 4962206
    Abstract: A process for the production of 4-bromophthalic anhydride which comprises the reaction of 4-chlorotetrahydrophthalic anhydride with elemental bromine, in the presence of a catalytically effective amount of iron or an iron salt is disclosed.
    Type: Grant
    Filed: November 20, 1989
    Date of Patent: October 9, 1990
    Assignee: Occidental Chemical Corporation
    Inventors: Mary K. Cocoman, Willis T. Schwartz
  • Patent number: 4960885
    Abstract: A composition having the formula ##STR1## wherein n has an average value of one to about five, is disclosed for use in reducing or eliminating the formation of reactor scale during the polymerization of vinyl chloride and comonomers. The composition is prepared by reacting phenothiazine with formaldehyde in the presence of a liquid diluent that is a solvent for the phenothiazine, but a non-solvent for the dimer of phenothiazine and formaldehyde. The process of the invention is preferably conducted in the presence of a strong acid catalyst. The formaldehyde is preferably added slowly to the reaction mixture over the course of the reaction. The product can be filtered and dried.
    Type: Grant
    Filed: February 16, 1989
    Date of Patent: October 2, 1990
    Assignee: Occidental Chemical Corporation
    Inventors: Raymond C. DeWald, Paul O. Hong
  • Patent number: 4960905
    Abstract: Phenoxy phthalic anhydrides are prepared by the reaction of a fluorophthalic anhydride with a phenol compound in the presence of potassium fluoride and a polar, aprotic solvent.
    Type: Grant
    Filed: December 15, 1988
    Date of Patent: October 2, 1990
    Assignee: Occidental Chemical Corporation
    Inventor: Willis T. Schwartz
  • Patent number: 4960938
    Abstract: 2-Chlorobenzylamine is prepared from 2-chlorobenzylchloride in a two-step process. In the first step, 2-chlorobenzylchloride is reacted with alkali metal phthalimide, preferably formed in situ from potassium carbonate and phthalimide, to form the novel intermediate 2-chlorobenzylphthalimide. In the second step, the phthalimide ring of the 2-chlorobenzylphthalimide is cleaved to form 2-chlorobenzylamine. The first step is preferably carried out in an unreactive solvent at 60.degree. C. to reflux temperature, for example, for 1 to 10 hours. The solvent is very preferably dimethylformamide which is advantageously recovered and used again as solvent in the conversion of 2-chlorobenzylchloride to 2-chlorobenzylphthalimide. The second step consists essentially, for example, of hydrazinolysis or hydrolysis.
    Type: Grant
    Filed: November 2, 1988
    Date of Patent: October 2, 1990
    Assignee: Occidental Chemical Corporation
    Inventors: Neil J. O'Reilly, Stanley A. Sojka, Henry C. Lin
  • Patent number: 4957993
    Abstract: Substantially fully imidized polyimidesiloxanes which are based on a selected pyridine compound are soluble in diglyme which gives them particular utility in the micro-electronics industry. The polymers are prepared from the dianhydride, a difunctional siloxane monomer and an organic diamine that has the formula ##STR1## wherein X is hydrogen, halide, phenyl or combinations thereof, Z=--O--, --S--, ##STR2## >C(CX.sub.3).sub.2, --, or --Y--Ar--Y--. Ar= ##STR3## Y=--O--, --S--, ##STR4## >C(CX.sub.3).sub.2, or --. n=0 or 1.The preferred diamine has the formula ##STR5## Other diamines can be used to provide an asymmetrical structure in the polyimidesiloxane polymer chain. The polyimidesiloxane can be prepared with functional groups which render them directly curable. The polyimidesiloxanes can also be prepared with functional groups which when reacted with an unsaturated compound renders the polymers curable.
    Type: Grant
    Filed: November 14, 1988
    Date of Patent: September 18, 1990
    Assignee: Occidental Chemical Corporation
    Inventor: Chung J. Lee
  • Patent number: 4956437
    Abstract: Substantially fully imidized polyimidesiloxanes which are based on a sulfurdiphthalic anhydride are soluble in diglyme which gives them particular utility in the micro-electronics industry. The polymers are prepared from the dianhydride, a difunctional siloxane monomer and an organic diamine. Diamines can be used to provide an asymmetrical structure in the polyimidesiloxane polymer chain. The polyimidesiloxane can be prepared with functional groups which render them directly curable. The polyimidesiloxanes can also be prepared with functional groups which when reacted with an unsaturated compound renders the polymers curable. The products of the invention can be used in the form of solutions in the micro-electronic industry. The polymers can also be used in wire and cable coating and to prepare films, fibers, and molded and extruded articles.
    Type: Grant
    Filed: June 10, 1988
    Date of Patent: September 11, 1990
    Assignee: Occidental Chemical Corporation
    Inventor: Chung J. Lee
  • Patent number: 4956423
    Abstract: Improved hot melt adhesives comprise a blend of a polyamide and a polyetheramide. The polyamides have the following general structure ##STR1## wherein A is a linear, branched or cyclic aliphatic hydrocarbon radical, which can be substituted with a halogen such as chlorine or bromine, when fire retardant products are desired, and wherein B is a linear or branched, saturated or unsaturated, aliphatic hydrocarbon radical, which can be substituted with halogen such as chlorine or bromine when fire retardant products are desired. The polyamides can also contain a residue of a saturated aliphatic hydrocarbon dicarboxylic acid. The value of x of the polymer formula is generally in the range of 5 to about 500, more usually in the range of about 20 to about 100. The polyetheramides have the following general structure:(PA--Y--PE).sub.
    Type: Grant
    Filed: October 29, 1985
    Date of Patent: September 11, 1990
    Assignee: Occidental Chemical Corporation
    Inventor: Chung J. Lee