Patents by Inventor Hang Chang

Hang Chang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6222079
    Abstract: Disclosed is a method of increasing the percentage of certain isomers made when di or tri-substituted benzenes are chlorinated in the presence of a Friedel-Crafts catalyst. The use of about 0.001 to about 1 wt % a cocatalyst during chlorination alters the isomeric ratio of the product mixture. In particular, the percentage of the 2,5-isomer is increased when said substituted benzene is ortho or meta-substituted, the percentage of the 3,4-isomer is increased when said substituted benzene is para-substituted, and the percentage of the 2,4,5-isomer is increased when said substituted benzene is 2,4-disubstituted, 3,4-disubstituted, or 2,5-disubstituted.
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: April 24, 2001
    Assignee: Occidental Chemical Corporation
    Inventors: Dean R. Lagerwall, Pravin M. Khandare, Hang-Chang Bobby Chen, Mark F. Lechner
  • Patent number: 6196526
    Abstract: A mechanical wet air generator which is constructed by an inner container, an outer container, a fluid level controller and a multiplicity of Rashing rings filled in the inner container is provided. In the wet air generator, the inner container is formed of honeycomb panels such that large bubbles cannot go through and furthermore, the multiplicity of Rashing rings functions as bubble-breaking solid shapes further prevents large bubbles from exiting the wet air generator and insuring the proper functioning of the generator. The present invention novel mechanical wet air generator is provided with a fluid level controller which consists of a floater, a floating valve, and a linkage connecting thereinbetween. The novel fluid level controller effectively prevents any possibility of overflow of fluid, or water, into a slurry supply pipe to which the wet air generator supplies a wet air or wet N2 for transporting and for blanketing the slurry solution.
    Type: Grant
    Filed: August 3, 1999
    Date of Patent: March 6, 2001
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd
    Inventors: Hang-Chang Lee, Long Chun Tsai, Ming-Tzung Hsu
  • Patent number: 6156945
    Abstract: Disclosed is a method of making high purity 2,4- and 3,4-dichlorotoluene from parachlorotoluene that contains some metachlorotoluene. About 0.0001 to about 5 wt % of a Friedel-Crafts catalyst and about 0.5 to about 10 equivalents of a brominating agent are added to the parachlorotoluene. The metachlorotoluene is brominated, but most of the parachlorotoluene is not brominated. Without separating the brominated products from the unbrominated products, about 0.5 to about 1.5 equivalents of a chlorinating agent are added, whereby only the unbrominated products (i.e., the parachlorotoluene) are chlorinated. The resulting 2,4-dichlorotoluene and 3,4-dichlorotoluene can be separated by distillation.
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: December 5, 2000
    Assignee: Occidental Chemical Corporation
    Inventors: Viesturs Lesins, Arthur H. Morth, Frank P. Bermel, David Y. Tang, Mark E. Lindrose, William L. Rueter, Dean R. Lagerwall, Pravin M. Khandare, Hang-Chang Bobby Chen, Mark F. Lechner
  • Patent number: 6020299
    Abstract: Disclosed is a single phase mixture of about 1 to about 99 wt % of a compound having the general formula ##STR1## where "n" is 1 or 2 and about 0.1 to about 99 wt % of a liquid which can be a perfluoro aliphatic alkane from C.sub.5 to C.sub.8, a perfluoro cycloaliphatic alkane from C.sub.5 to C.sub.8, a perfluoro alkylcycloalkane having 5 to 8 carbon atoms in the ring and 1 or 2 branches of 1 to 3 carbon atoms each, a perfluoro-N-alkylmorpholine from C.sub.5 to C.sub.8, a perfluoro cycloether from C.sub.4 to C.sub.7, or a perfluoro polyether having an average molecular weight from about 400 to about 500.
    Type: Grant
    Filed: October 27, 1994
    Date of Patent: February 1, 2000
    Assignee: Occidental Chemical Corporation
    Inventors: Hang-Chang Bobby Chen, Mark E. Lindrose
  • Patent number: 6005139
    Abstract: Disclosed is an improved process for reacting a halogenated ester with an alkali metal alkoxide to form an alkoxy ester and a salt. A solvent is added to the halogenated ester prior to the addition of the alkali metal alkoxide. This results in a substantial increase in the particle size of the salt which greatly facilitates its separation from the solution of the alkoxy ester product.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: December 21, 1999
    Assignee: Occidental Chemical Corporation
    Inventors: Hang-Chang Bobby Chen, Dean R. Lagerwall, Lewis A. Bernstein
  • Patent number: 5851435
    Abstract: Disclosed is a cleaning composition of about 80 to about 99 wt % benzotrifluoride, about 1 to about 20 wt % monohydric alkanol from C.sub.1 to C.sub.4, and up to about 20 wt % of a fluorocarbon having the general formula C.sub.m H.sub.n F.sub.2m+2n, where m is 4 to 8 and n is 1 to m/2 if m is even and (m+1)/2 if m is odd. The composition is useful in cleaning greases, oils, solder fluxes, and other soils.
    Type: Grant
    Filed: May 10, 1996
    Date of Patent: December 22, 1998
    Assignee: Occidental Chemical Corporation
    Inventors: Hang-Chang Bobby Chen, Edward A. Rowe
  • Patent number: 5756002
    Abstract: A cleaning solvent comprising(A) about 3 to about 20 wt % of a fluorinated compound selected from the group consisting of(1) fluorocarbons having the general formulaC.sub.m H.sub.n F.sub.2m+2-nwhere m is 4 to 8, and n is 0 to m/2 if m is even and 0 to (m+1)/2 if m is odd;(2) C.sub.5 F.sub.11 NO;(3) alkyl perfluoroethers having the general formulaR.sub.1 OR.sub.2where R.sub.1 is C.sub.3 F.sub.7 or C.sub.4 F.sub.9 and R.sub.2 is CH.sub.3 or C.sub.2 H.sub.5 ; and(4) fluorochlorocarbons having the general formulaC.sub.p H.sub.q Cl.sub.r F.sub.2p+2-q-rwhere p is 3, 4, or 5, q is 1 to p-1, and r is 1 to p-1;(B) up to about 15 wt % of a C.sub.1 to C.sub.4 alkanol; and(C) the remainder benzotrifluoride.
    Type: Grant
    Filed: May 10, 1996
    Date of Patent: May 26, 1998
    Assignee: Occidental Chemical Corporation
    Inventors: Hang-Chang Bobby Chen, Edward A. Rowe
  • Patent number: 5744437
    Abstract: Disclosed is a single phase liquid composition comprising 0.5 to 30 wt % of a benzotrifluoride solvent, about 0.5 to about 50 wt % of a glycol ether cosolvent, up to about 50 wt % of an alkanol, up to about 10 wt % of a surfactant, and the remainder water. The composition is effective in cleaning hard surfaces, stripping paint, and as a carrier.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: April 28, 1998
    Assignee: Occidental Chemical Corporation
    Inventors: Edward A. Rowe, Hang-Chang Bobby Chen, Mark E. Lindrose
  • Patent number: 5705728
    Abstract: The present invention provides an efficient process for the production of ethylene or a mixture of ethylene and vinyl chloride, in which some 1,2-dichloroethane (EDC) may also be produced, by reacting chlorine with ethane. The process is characterized by a conversion of ethane per pass through the reactor of at least about 50%, and a combined molar yield of ethylene and vinyl chloride of at least about 80% based on the ethane consumed. In accordance with this invention, there is provided a process for preparing ethylene or a mixture of ethylene and vinyl chloride by the reaction of ethane and chlorine which comprises:(a) providing a stream of ethane feed gas and a stream of chlorine feed gas;(b) preheating either said ethane stream only or both said ethane and chlorine streams;(c) thoroughly mixing said ethane and chlorine feed gases within about one second and at a molar ratio of ethane to chlorine of at least about 0.9:1.
    Type: Grant
    Filed: February 10, 1995
    Date of Patent: January 6, 1998
    Assignee: Occidental Chemical Corporation
    Inventors: Krishnan Viswanathan, Hang-Chang Bobby Chen, Sidney W. Benson
  • Patent number: 5446232
    Abstract: Disclosed is a method and apparatus for removing oxygen from hydrogen, hydrocarbon, or halogenated hydrocarbon gas which contains about 0.01 to about 10 mole % oxygen. The oxygen removal is accomplished by contacting the gas with a Hopcalite catalyst at a temperature of about 100.degree. to about 300.degree. C. The invention can be part of a process for making 1,2-dichloroethane where, in a first reaction, ethane and chlorine are reacted to make ethylene and hydrogen chloride and, in a second reaction, the ethylene and hydrogen chloride are reacted with excess oxygen to make the 1,2-dichloroethane. The unreacted ethane can be recycled to the first step after the method of the invention is applied to remove the oxygen.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: August 29, 1995
    Assignee: Occidental Chemical Corporation
    Inventors: Hang-Chang B. Chen, Deborah J. Olsen
  • Patent number: 5113028
    Abstract: A process for mixing hot ethane with chlorine gas using a mixer consisting of a main pipe through which ethane is conducted, and four or more jets through which chlorine gas is introduced into the main pipe. The angle between the axis of each jet and the line from the center point to the point where the axis of each jet makes contact with the inside surface of the main pipe ranges between about 30.degree. to 45.degree..
    Type: Grant
    Filed: August 1, 1991
    Date of Patent: May 12, 1992
    Inventors: Hang-Chang B. Chen, Gerald F. Achee