Elemental Sulfur Or Inorganic Sulfur Compound Patents (Class 525/354)
-
Patent number: 4587306Abstract: Improvements in the preparation of polymers of hydroxamic functions that consist in heating a polyacrylamide aqueous solution with a hydroxylamine salt at temperatures of from about 50.degree. to 85.degree. C.The polymers obtained are used as adjuvants of soil drilling muds, especially in petroleum drilling.The invention concerns itself with improvements in the preparation of polymers of hydroxamic functions, the resulting novel polymers, and applications thereof. The invention provides for the obtention of such polymers having a desired number of hydroxamic groups without noticeable formation of objectionable secondary products; it makes possible, in addition, the preparation of derivatives wherein the chain of the polymer and/or the hydroxamic groups contain different substituents.Type: GrantFiled: August 24, 1983Date of Patent: May 6, 1986Assignee: Societe Nationale Elf AquitaineInventors: Lino Vio, Gilles Meunier
-
Patent number: 4575531Abstract: Sulfur vulcanizable partially hydrolyzed ethylene-vinyl acetate terpolymers and processes for producing these products are disclosed.Type: GrantFiled: November 7, 1984Date of Patent: March 11, 1986Assignee: National Distillers and Chemical CorporationInventors: John M. Hoyt, Steven D. Blazey
-
Patent number: 4563506Abstract: A process for the continuous bromination of butyl rubber polymer by contacting the polymer with a brominating agent in a continuous flow device in which means are provided for disengaging reaction by-products and unreacted halogenating agents from the reaction mixture, by deforming and disrupting the brominated polymer surface and injecting a neutralizing agent into the polymer immediately after reaction thereby neutralizing the polymer, comprising contacting a polymer substantially free of acid scavengers, with the brominating agent at elevated temperatures the bromination reaction being carried out in an acid atmosphere, thereby producing a polymer having a substantial fraction of the bromine in the primary allylic position.Type: GrantFiled: October 1, 1984Date of Patent: January 7, 1986Assignee: Exxon Research & Engineering Co.Inventors: Ronald C. Kowalski, William M. Davis, Neil F. Newman, Zisis A. Foroulis, Francis P. Baldwin
-
Patent number: 4554326Abstract: In a process for the continuous halogenation of polymers by contacting polymer and halogenating agent in a continuous flow device in which the polymer and halogenating agent are subjected to deformation during reaction and in which means are provided for disengaging reaction by-products and unreacted halogenating agent from the reaction mixture, a significant process improvement is realized by injecting an inert gas into the halogenated polymers immediately after reaction in order to neutralize the product. In a preferred embodiment the process is carried out in an extruder-reactor and an optional, supplementary inert gas scrubbing zone is included. The process is amenable to saturated and unsaturated polymers.Type: GrantFiled: April 1, 1983Date of Patent: November 19, 1985Assignee: Exxon Research & Engineering Co.Inventors: Ronald C. Kowalski, William M. Davis, Neil F. Newman, Z. Andrew Foroulis, Francis P. Baldwin
-
Patent number: 4548995Abstract: In a process for the continuous halogenation of polymers by contacting polymer and halogenating agent in a continuous flow device in which means are provided for disengaging reaction by-products and unreacted halogenating agent from the reaction mixture, by deforming and disrupting the halogenated polymer surface and injecting an inert gas into the halogenated polymers immediately after reaction thereby neutralizing the product. In a preferred embodiment the process is carried out in an extruder-reactor and an optional, supplementary inert gas scrubbing zone is included. The process is amenable to saturated and unsaturated polymers.Type: GrantFiled: September 17, 1984Date of Patent: October 22, 1985Assignee: Exxon Research & Engineering Co.Inventors: Ronald C. Kowalski, William M. Davis, Neil F. Newman, Z. Andrew Foroulis, Francis P. Baldwin
-
Patent number: 4542191Abstract: Tackifying agents for rubber comprising at least one chemically or physically treated guayule resin fraction are disclosed. Physical treatments include vacuum deoiling, steam stripping deoiling, hexane deoiling, while chemical treatments include formaldehyde reaction, phenol/formaldehyde reaction, urea formaldehyde reaction, acid reaction and sulphur reaction. Untreated guayule resin fractions can also be used. Vulcanized and unvulcanized rubber compositions containing guayule resin derived tackifying agents as well as articles made therefrom are also disclosed.Type: GrantFiled: October 19, 1981Date of Patent: September 17, 1985Assignee: The Firestone Tire & Rubber CompanyInventors: Edward L. Kay, Richard Gutierrez
-
Patent number: 4537922Abstract: The present invention is a sulfur stabilized composition. The composition comprises an oxidized polyolefin, preferably oxidized polyethylene or oxidized polypropylene, with oxidized polyethylene being most preferred. The composition of the present invention optionally contains a filler.Type: GrantFiled: November 14, 1983Date of Patent: August 27, 1985Assignee: Allied CorporationInventors: Irving B. Chang, Robert E. Beckwith, Jr.
-
Patent number: 4529766Abstract: A preferred carboxylated nitrile rubber is prepared by polymerizing a diene, a nitrile and a small amount of an acrylic acid, which rubber has distributed therethrough an amount of alkyl or alkenyl monocitrate to obtain improved scorch time and reduced cure time.Type: GrantFiled: June 8, 1984Date of Patent: July 16, 1985Assignee: The B. F. Goodrich CompanyInventor: Philip H. Starmer
-
Patent number: 4526935Abstract: Water soluble polyamines useful as flocculating agents are prepared by reaction of acrylonitrile polymers in solution with dialkylaminoalkylamines using ammonium polysulfide as catalyst.Type: GrantFiled: May 6, 1983Date of Patent: July 2, 1985Assignee: E. I. Du Pont de Nemours and CompanyInventor: William K. Wilkinson
-
Patent number: 4513116Abstract: Continuous halogenation of polymers is achieved by contacting polymer and halogenating agent in a continuous flow device in which the reactants are present as either co-continuous phases or wherein the halogenating agent is present as a continuous phase and the polymer is present as a discontinuous phase, the polymer is subjected to deformation during reaction and in which means are provided for disengaging reaction by-products and unreacted halogenating agent from the reaction mixture. In a preferred embodiment the polymer passes through three extruder-reactor zones under controlled conditions to achieve halogenation: feed, reaction (preferably vented), neutralization, and optionally a wash and exit zone. A continuous halogenating agent phase is achieved during reaction by avoiding complete filling of the reaction zone with polymer. Various halogenated polymers are produced, for example, halogenated linear low density polyethylene and halogenated butyl rubber.Type: GrantFiled: April 1, 1983Date of Patent: April 23, 1985Assignee: Exxon Research and Engineering Co.Inventors: Ronald C. Kowalski, William M. Davis, Neil F. Newman, Lewis Erwin
-
Patent number: 4463135Abstract: There is disclosed a process for the functionalization of polymeric resins, wherein a halo-methylated resin, with a crosslink density of at least 4 percent is reacted with an alkyllithium wherein the alkyl radical is 1 to 12 carbon atoms; followed by a reaction to produce a polymeric material having a desired pendant functionality. Materials produced from the process of this invention have utility as intermediates in the production of polymer-bound catalysts and exchange resins.Type: GrantFiled: October 25, 1982Date of Patent: July 31, 1984Assignee: The Goodyear Tire & Rubber CompanyInventor: Neil A. Maly
-
Patent number: 4394205Abstract: A method for bonding unvulcanized fluorinated elastomers to vulcanized non-fluorinated elastomers comprising exposing the vulcanized elastomer to a fluorinating agent; applying a conventional fluorinate elastomer adhesive to the treated vulcanized elastomer; contacting the adhesive-coated portion of the vulcanized elastomer with the unvulcanized fluorinated elastomer; and curing in situ the fluorinated elastomer. Sulfur tetrafluoride is a preferred fluorinating agent.Type: GrantFiled: March 15, 1982Date of Patent: July 19, 1983Assignee: Lord CorporationInventor: Donald R. Blenner
-
Patent number: 4383087Abstract: Organic polymer layered trichalcogenides, such as a cyclopentadienyl transition metal trichalcogenide-substituted styrene divinylbenzene copolymer, are useful as the cathode active material for lithium nonaqueous secondary batteries which operate on the principle of intercalation and elsewhere.Type: GrantFiled: February 4, 1982Date of Patent: May 10, 1983Assignee: Combustion Engineering, Inc.Inventor: David N. Palmer
-
Patent number: 4383088Abstract: Organic polymer layered dichalcogenides, such as a transition metal metallocene dichalcogenide-substituted styrene divinylbenzene copolymer, are useful as the cathode active material for lithium nonaqueous secondary batteries which operate on the principle of intercalation and elsewhere.Type: GrantFiled: February 4, 1982Date of Patent: May 10, 1983Assignee: Combustion Engineering, Inc.Inventor: David N. Palmer
-
Patent number: 4341672Abstract: Sulfur or peroxy cured compositions prepared from epoxidized diene rubbers.Type: GrantFiled: September 19, 1980Date of Patent: July 27, 1982Assignee: Phillips Petroleum CompanyInventors: Henry L. Hsieh, Kishore Udipi
-
Patent number: 4309318Abstract: A tread composition for low rolling resistance tires, comprising 100 parts by weight of styrene-butadiene rubber or a styrene-butadiene rubber-based rubber blend and 3.2-5.0 parts by weight of sulphur.Type: GrantFiled: November 16, 1979Date of Patent: January 5, 1982Assignee: Yokohama Rubber Co., Ltd.Inventors: Asahiro Ahagon, Makoto Misawa, Hiroshi Hirakawa, Kazuo Miyasaka
-
Patent number: 4303560Abstract: A rubbery polymer composition comprises a crosslinked copolymer comprising the following components.Type I15 to 40 wt. parts of a vinyl carboxylate having the formula (I); 60 to 85 wt. parts of an alkoxyalkyl acrylate having the formula (II); 0 to 15 wt. parts of ethylene; (100 wt. parts of a total of said three components); 0 to 5 wt. parts of the components having the formula (III), (IV) or (V):Type II15 to 55 wt. parts of a vinyl carboxylate having the formula (I); 5 to 20 wt. parts of ethylene; an alkyl acrylate having the formula (II'); an alkoxyalkyl acrylate having the formula (II) (100 wt. parts of a total of said four components and more than 0.8 of a ratio of the alkoxyalkyl acrylate (II) to the alkyl acrylate (II') by weight); 0 to 5 wt. parts of the components having the formula (III), (IV) or (V):(I): RCOO--CH.dbd.CH.sub.2wherein R represents a C.sub.1-4 alkyl group.(II): CH.sub.2 .dbd.CHCOO--R.sub.1 --O--R.sub.2wherein R.sub.1 represents a C.sub.1-4 alkylene group; and R.sub.2 represents a C.Type: GrantFiled: November 16, 1979Date of Patent: December 1, 1981Assignee: Denki Kagaku Kogyo Kabushiki KaishaInventors: Kohki Takahashi, Takeo Kondoh, Masao Koga, Kenichiro Nishiwaki
-
Patent number: 4294943Abstract: A process for preparing a fluorine-containing polymer having carboxyl groups, which comprises subjecting a fluorine-containing polymer having sulfonyl halide groups bonded to it to an oxidation reaction at a temperature of not more than 250.degree. C.; and a process for electrolysis, using as a diaphragm a member of the polymer obtained by the above process.Type: GrantFiled: November 28, 1979Date of Patent: October 13, 1981Assignee: Tokuyama Soda Kabushiki KaishaInventors: Yasuharu Onoue, Toshikatsu Sata, Akihiko Nakahara, Junichi Itoh
-
Patent number: 4284743Abstract: A process for the cross-linking of high density polyethylene in the solid state according to which the polyethylene is admixed with the agents normally used for the vulcanization of unsaturated rubber compounds, then processed into the desired article and thereafter cross-linked at a temperature lower than the melting point of the polyethylene, the process being carried out in polyethylene containing a certain number of unsaturated bonds along the polymer chain.Type: GrantFiled: December 17, 1979Date of Patent: August 18, 1981Assignee: Anic S.p.A.Inventors: Gian P. Giuliani, Roberto Paiella
-
Patent number: 4284742Abstract: A puncture-sealing tubeless pneumatic tire having an inner layer of soft, tacky, extensible sealant consisting of (1) at least one vinylidene-terminated liquid polymer and (2) at least one amine.Type: GrantFiled: January 21, 1980Date of Patent: August 18, 1981Assignee: The B. F. Goodrich CompanyInventors: Harold H. Bowerman, Jr., Robert W. Ireland
-
Patent number: 4277579Abstract: The molecular weight of chlorine containing elastomers are increased by adding sulphur compounds before or during the chlorination of elastomers.Type: GrantFiled: July 9, 1979Date of Patent: July 7, 1981Assignee: Bayer AktiengesellschaftInventors: Manfred Beck, Wilhelm Gobel
-
Patent number: 4265628Abstract: A process for the preparation of fire retardant formed bodies such as yarns and films of acrylic polymers is disclosed. The process comprises subjecting the polymer to sulphuration and subjecting the sulphurated polymer to a basic treatment by means of an alkali metal hydroxide, such as sodium hydroxide, whereby the polymer molecule acquires a cyclic structure.Type: GrantFiled: July 27, 1979Date of Patent: May 5, 1981Assignee: SNIA Viscosa Societa' Nazionale IndustriaInventors: Pier P. Rossi, Aldo Tempesti, Aldo Filippi
-
Patent number: 4263075Abstract: A puncture-sealing tubeless pneumatic tire having an inner layer of soft, tacky, extensible sealant consisting of (1) at least one vinylidene-terminated liquid polymer and (2) at least one amine.Type: GrantFiled: January 21, 1980Date of Patent: April 21, 1981Assignee: The B. F. Goodrich CompanyInventors: Harold H. Bowerman, Jr., Robert W. Ireland
-
Patent number: 4262098Abstract: A halogenated polyethylene, or a mixture of it with a sulfur-curable rubber and/or a vinyl chloride resin can be cured with a combination of sulfur and/or a sulfur donor, and at least one amino acid selected from the group consisting of lysine, ornithine, arginine and proline.Type: GrantFiled: July 10, 1978Date of Patent: April 14, 1981Assignee: Sanyo Trading Co., Ltd.Inventor: Masao Onizawa
-
Patent number: 4259403Abstract: An acid of the formula A--COOH).sub.x, or an anhydride thereof, wherein x is an integer of 1 or 2, wherein the acid groups are vicinal if x is 2, and A is phenyl, C.sub.2 -C.sub.10 alkylene, C.sub.2 -C.sub.10 alkenylene, C.sub.6 -C.sub.10 bridged or nonbridged cycloalkylene or cylcoalkenylene, with the proviso that A is C.sub.1 -C.sub.6 alkyl if x is 1, renders ethylene-propylene-nonconjugated diene elastomers more adherent to fibers that have been treated with a resorcinol-formaldehyde-latex dip when said elastomers are cured directly onto said fibers.Type: GrantFiled: January 16, 1979Date of Patent: March 31, 1981Assignee: Uniroyal, Inc.Inventor: Richard W. Tomlinson
-
Polymers of conjugated dienes which have terminal conjugated unsaturated alicyclic functional groups
Patent number: 4258162Abstract: Alicyclic organomonolithium compounds having delocalized conjugated unsaturation are effective initiators in the preparation of polymers of conjugated dienes. Polymers of conjugated dienes, prepared with or without the alicyclic organomonolithium compounds, are terminated with alicyclic compounds having conjugated unsaturation. Either or both approaches can be used to provide polymers containing alicylic conjugated unsaturated functional groups. Alternatively, polymers prepared from the alicyclic organomonolithium compounds can be coupled to produce linear or branched polymers. Polymers prepared from multichelic lithium compounds also can be terminated with alicyclic conjugated unsaturated compounds.Type: GrantFiled: July 10, 1979Date of Patent: March 24, 1981Assignee: Phillips Petroleum CompanyInventors: Carl A. Uraneck, John E. Burleigh -
Patent number: 4254250Abstract: Amine polymers are used to dewater suspensions of particulate matter in water. The polymers are synthesized by the reaction of a nitrile polymer such as polyacrylonitrile, an aminating agent, and a sulfur activator. The dewatering properties of these amine polymers can be beneficially employed to treat sewage sludge, silt laden water, industrial waste and the like.Type: GrantFiled: December 4, 1978Date of Patent: March 3, 1981Assignee: Pfizer Inc.Inventors: Raymond C. Glowaky, Steven R. Kurowsky, Robert J. Sysko
-
Patent number: 4252918Abstract: When an elastomeric copolymer of a C.sub.4 or C.sub.5 conjugated diene and an aromatic vinyl compound is brominated in latex while keeping the uniformity of the latex until the amount of bormine combined with the copolymer reaches 0.5-15% by weight, the resulting brominated conjugated diene-aromatic vinyl compound rubber contains 3-80% by weight of a toluene-insoluble fraction formed by the bromination and has a high green strength and a good processability. A vulcanized rubber obtained from said brominated rubber has a high modulus of elasticity and a high tensile strength. When an anionic surfactant is used as an emulsifier, the uniformity of the above-mentioned latex can be kept by adjusting the pH value of the bromination reaction system to 9 or highter, preferably 10 or higher, during the reaction or by auxiliarily adding a nonionic surfactant. When a cationic or nonionic surfactant is used as an emulsifier, regulation of pH is unnecessary.Type: GrantFiled: May 30, 1979Date of Patent: February 24, 1981Assignee: Japan Synthetic Rubber Co., Ltd.Inventors: Hiroharu Ikeda, Yasuyuki Shimozato, Kohei Goto
-
Patent number: 4248985Abstract: A sulfur-curable acrylic rubber composition is provided which comprises [I] 100 parts of an acrylic rubber resulting from the copolymerization in the presence of a radical initiator of (1) 30 to 89.5% by weight of at least one alkyl acrylate with the alkyl group containing 1 to 8 carbon atoms, (2) 0.5 to 10% by weight of at least one monomer of the general formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group, and R.sub.2 and R.sub.3, independently from each other, represent an alkyl group containing 1 to 3 carbon atoms, (3) 10 to 60% by weight of at least one alkoxyalkyl acrylate with the alkoxy group containing 1 to 4 carbon atoms and the alkylene group containing 1 to 4 carbon atoms, and 0 to 30% by weight of at least one of monovinyl and monovinylidene unsaturated compounds other than the said compounds; and [II] 1 to 5 parts by weight of a metal compound, and [III] 0.2 to 5 parts by weight, as sulfur, of at least one of sulfur and sulfur-containing organic compounds.Type: GrantFiled: March 27, 1979Date of Patent: February 3, 1981Assignee: Nippon Zeon Co., Ltd.Inventors: Tetsu Ohishi, Kohichi Handa, Haruo Ueno
-
Patent number: 4246370Abstract: Polymers of esters of acrylic acid having an average chain length of about 6 to about 30 mers are prepared by an anionic polymerization reaction, carried out in the presence of a catalytic amount of an alkoxide anion. These polymers, their hydrolysis products, and their derivatives have a wide variety of applications, including among others use as components in films, coatings, fibers, impregnants, adhesives, and binders, and use as modifiers, plasticizers, melt flow improvers, and leveling agents.Type: GrantFiled: March 5, 1979Date of Patent: January 20, 1981Assignee: Rohm and Haas CompanyInventors: Sheldon N. Lewis, Richard A. Haggard
-
Patent number: 4237258Abstract: Vulcanizable elastomers consisting of copolymers of acrylic esters are prepared by copolymerizing an alkyl acrylate with minor amounts of an ethylenically unsaturated monomer containing halogen, an ethylenically unsaturated monomer having an epoxy group, an ethylenically unsaturated carboxylic acid and, optionally, a polyene containing at least two non-conjugated double bonds. The new acrylic elastomers obtained have a high vulcanization rate and are useful in the manufacture of various shaped articles by processes involving a fast vulcanization cycle.Type: GrantFiled: April 13, 1979Date of Patent: December 2, 1980Assignee: Montedison S.p.A.Inventors: Giuseppe Cantalupo, Sergio De Servi, Agostino Lepori
-
Patent number: 4228257Abstract: A polymer comprising acrylamide units or anionic sulfonate units and a unit having the formula: ##STR1## wherein: R is H, halogen or alkyl;L is a linking group; andM is H, an ammonium cation or an alkali metal, can be metallized to form a metallized polymer. The metallized polymer is useful either as or with a mordant for dyes or dye formers that chelate metals.Type: GrantFiled: June 6, 1979Date of Patent: October 14, 1980Assignee: Eastman Kodak CompanyInventors: Gerald A. Campbell, Lewis R. Hamilton, David P. Brust
-
Patent number: 4216126Abstract: The vulcanization rate of rubber stock compounded for curing is increased by using in the stock for the cure an accelerator of certain amine-substituted esters of phosphorodithioic acid.Type: GrantFiled: September 28, 1978Date of Patent: August 5, 1980Assignee: The Firestone Tire & Rubber CompanyInventor: Edward L. Kay
-
Patent number: 4214619Abstract: A puncture-sealing tubeless pneumatic tire having an inner layer of soft, tacky, extensible sealant consisting of (1) at least one vinylidene-terminated liquid polymer and (2) at least one amine.Type: GrantFiled: April 28, 1977Date of Patent: July 29, 1980Assignee: The B. F. Goodrich CompanyInventors: Harold H. Bowerman, Jr., Robert W. Ireland
-
Patent number: 4214058Abstract: A vulcanizable rubber composition having an excellent adhesive property when vulcanized in contact with metals is obtained by compounding(a) 100 parts by weight of a raw rubber(b) from 0.5 to 10 parts by weight of a vulcanizing agent, and(c) from 0.01 to 1 part by weight (as metal content) of at least one metal compound selected from the class consisting of organic acid salts of titanium and molybdenum and organic complex compounds of titanium, molybdenum and cobalt.The vulcanizable rubber composition thus obtained is not susceptible to the oxidative deterioration in unvulcanized state during the storage.Type: GrantFiled: October 17, 1977Date of Patent: July 22, 1980Assignee: Bridgestone Tire CompanyInventors: Takaaki Imamura, Takahiro Kawagoe, Toshio Chikaraishi, Takashi Nyomura
-
Patent number: 4197220Abstract: Amine containing polymeric microspheres such as polyvinyl pyridine are complexed with metal salts or acids containing metals such as gold, platinum or iron. After reduction with sodium borohydride, the salt is reduced to finely divided free metal or metal oxides, useful as catalysts. Microspheres containing covalent bonding sites can be used for labeling or separating proteins.Type: GrantFiled: May 26, 1978Date of Patent: April 8, 1980Assignee: California Institute of TechnologyInventors: Alan Rembaum, Willi Volksen
-
Patent number: 4195143Abstract: Disclosed is a sulfur-cured rubber article that has high resistance to reversion and low compression set which is post-modified to improve its fatigue life. The method involves introducing additional elemental sulfur in solution into the low sulfur-cured rubber article subsequent to curing.Type: GrantFiled: February 27, 1978Date of Patent: March 25, 1980Assignee: The General Tire & Rubber CompanyInventor: John G. Sommer, Jr.
-
Patent number: 4195142Abstract: Polymers having a tertiary amide group, particularly homopolymers and copolymers of vinylpyrrolidone, are modified by treatment with reactive acid chlorides, the amide functions being converted into amide chlorides. These modified polymers are reactive intermediates and may be used to obtain a variety of new polymeric substances.Type: GrantFiled: June 24, 1977Date of Patent: March 25, 1980Assignee: GAF CorporationInventor: Kenneth W. Dixon
-
Patent number: 4181648Abstract: Chlorosulfonated polyethylene stabilized with nickel dibenzyldithiocarbamate is more resistant to scorch before curing than compositions with other heat stabilizers but has equal or better stability to degradation by heat after cure.Type: GrantFiled: December 6, 1978Date of Patent: January 1, 1980Assignee: E. I. Du Pont de Nemours and CompanyInventor: Wolfgang Honsberg
-
Patent number: 4180633Abstract: Insoluble cross-linked homopolymers of vinylpyrrolidone or copolymers of vinylpyrrolidone are prepared by reaction of the soluble homopolymer or copolymer with certain acid chlorides at a temperature between 75.degree. C. and about 140.degree. C., to obtain a precipitate. Alternately, the insoluble product may be prepared by heating a partial amide chloride of a homopolymer or copolymer of vinylpyrrolidone.Type: GrantFiled: August 23, 1978Date of Patent: December 25, 1979Assignee: GAF CorporationInventor: Kenneth W. Dixon
-
Patent number: 4169115Abstract: Block copolymers of AB or ABA configuration are prepared by anionically polymerizing one component, terminating the living polymer with sulfur or an episulfide and completing polymerization of the remaining block portion by free-radical polymerization.Type: GrantFiled: May 22, 1978Date of Patent: September 25, 1979Assignee: The Dow Chemical CompanyInventors: Lu H. Tung, Grace Y. Lo, Billy E. Burgert