Patents by Inventor Lu H. Tung

Lu H. Tung 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: 5234999
    Abstract: Disclosed are bituminous blends having improved toughness and elasticity. The blends contain a bituminous binder and a tapered block copolymer formed from a monovinyl aromatic compound and a conjugated diene. Suitable tapered block copolymers include a tapered A-B-A type block copolymer of the A-t-B-t-A configuration, particularly those having an isolated monovinyl aromatic compound content of about 20 to about 90 weight percent, and tapered A-B-A type block copolymers of the A-B-t-A configuration having an isolated monovinyl aromatic compound content of about 20 to about 90 weight percent of the total monovinyl aromatic compound in the tapered block copolymer. Further disclosed is a method of making the blends. Further disclosed is a tapered A-B-A type block copolymer having an isolated monovinyl aromatic compound content of about 29 to about 75 weight percent.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: August 10, 1993
    Assignee: The Dow Chemical Company
    Inventors: Lu H. Tung, Ronald R. Pelletier, Ronald E. Snyder, William A. Gros
  • Patent number: 5166274
    Abstract: Novel diene/methacrylate ester block polymers, especially tertiary butyl methacrylate ester block polymers are uniquely prepared at near ambient temperatures and capable of being hydrolyzed and neutralized to yield the corresponding methacrylic acid and methacrylic acid salt (ionomer) derivatives. The compositions are usefully employed in the preparation of thermoplastic elastomers, adhesives and laminating films.
    Type: Grant
    Filed: July 30, 1990
    Date of Patent: November 24, 1992
    Assignee: The Dow Chemical Company
    Inventors: James E. McGrath, Timothy E. Long, Allan D. Broske, Lu H. Tung
  • Patent number: 5100939
    Abstract: Disclosed are bituminous blends having improved toughness and elasticity. The blends contain a bituminous binder and a tapered block copolymer formed from a monovinyl aromatic compound and a conjugated diene. Suitable tapered block copolymers include a tapered A-B-A type block copolymer of the A-t-B-t-A configuration, particularly those having an isolated monovinyl aromatic compound content of about 20 to about 90 weight percent, and tapered A-B-A type block copolymers of the A-B-t-A configuration having an isolated monovinyl aromatic compound content of about 20 to about 90 weight percent of the total monovinyl aromatic compound in the tapered block copolymer. Further disclosed is a method of making the blends. Further disclosed is a tapered A-B-A type block copolymer having an isolated monovinyl aromatic compound content of about 29 to about 75 weight percent.
    Type: Grant
    Filed: January 30, 1991
    Date of Patent: March 31, 1992
    Assignee: The Dow Chemical Company
    Inventors: John F. Vitkuske, Lu H. Tung, Ronald R. Pelletier, Ronald E. Snyder, William A. Gros
  • Patent number: 5100938
    Abstract: Disclosed are bituminous blends having improved toughness and elasticity. The blends contain an emulsion of a bituminous binder and an emulsion of a tapered block copolymer formed from a monovinyl aromatic compound and a conjugated diene. Suitable tapered block copolymers include a tapered A-B-A type block copolymer of the A-t-B-t-A configuration, particularly those having an isolated monovinyl aromatic compound content of about 20 to about 90 weight percent, and tapered A-B-A type block copolymers of the A-B-t-A configuration having an isolated styrene content of about 20 to about 90 weight percent of the total monovinyl aromatic compound in the tapered block copolymer. Also disclosed is a method of applying the blends to various surfaces.
    Type: Grant
    Filed: January 30, 1991
    Date of Patent: March 31, 1992
    Assignee: The Dow Chemical Company
    Inventors: John F. Vitkuske, Lu H. Tung, Ronald R. Pelletier, Ronald E. Snyder, William A. Gros
  • Patent number: 5057583
    Abstract: Narrow molecular weight telechelic and/or block copolymers are prepared by anionic polymerization using multifunctional lithium initiator in combination with a C.sub.2-16 lithium alkoxide.
    Type: Grant
    Filed: October 2, 1989
    Date of Patent: October 15, 1991
    Assignee: The Dow Chemical Company
    Inventors: Lu H. Tung, Jerald A. Griggs
  • Patent number: 5047484
    Abstract: Tapered block copolymers of monovinylidene aromatic monomers and conjugated diene monomers having an isolated polymerized monovinylidene atomatic content of from 30 to 75 percent, hydrogenated derivatives thereof and a process for their preparation.
    Type: Grant
    Filed: November 24, 1989
    Date of Patent: September 10, 1991
    Assignee: The Dow Chemical Company
    Inventor: Lu H. Tung
  • Patent number: 5013790
    Abstract: A thermoplastic blend useful for the preparation of molded articles comprising a thermoplastic polymer and a tapered triblock elastomer of a monovinylidene aromatic monomer and butadiene having a melt index (condition 200/5.0 ASTM method D1238-82) of 0.5 to 60 and an average molecular weight from 50,000 to 135,000.
    Type: Grant
    Filed: July 5, 1989
    Date of Patent: May 7, 1991
    Assignee: The Dow Chemical Company
    Inventors: Lu H. Tung, Joseph J. Randazzo
  • Patent number: 4873037
    Abstract: A method for preparing an asymmetric, semi-permeable membrane containing a uniform microporous structure for gas and liquid separation, including forming a dense separation on one major surface of a microporous support structure. The microporous support structure is initially formed as a solid unitary film, fiber or sheet by the simultaneous extrusion of at least two streams of heat-plastified polymeric materials including at least two differentially soluble polymeric materials. The separation layer can be formed on the support structure prior to or after the soluble polymeric material has been dissolved out of, as by leaching from the solid support structure to form the microporous support for the separation layer. Preparation in this manner greatly reduces the tendency to form undesiralbe pinholes in the membrane.
    Type: Grant
    Filed: October 5, 1988
    Date of Patent: October 10, 1989
    Assignee: The Dow Chemical Company
    Inventors: C. C. Chau, Jang-hi Im, Otto C. Raspor, Lu H. Tung
  • Patent number: 4775474
    Abstract: Asymmetric membranes are prepared by treating a major surface of a glassy polymer composition to render the surface resistant to solvent crazing and then contacting the glassy polymer composition with a crazing solvent. The crazing solvent permanently deforms the glassy polymer composition by forming a microporous structure on the untreated surface. The treated surface becomes the dense, discriminating layer of the membrane which achieves desirable permeation selectivity. The methods of treatment are (1) crosslinking, (2) providing an agent which renders the surface resistant to crazing, and (3) providing an agent which reacts with the surface. Additionally, the glassy polymer composition can be crosslinked before or after it is crazed to increase the mechanical strength of the membrane.
    Type: Grant
    Filed: December 1, 1986
    Date of Patent: October 4, 1988
    Assignee: The Dow Chemical Company
    Inventors: Chieh-Chun Chau, Charles E. Reineke, Lu H. Tung, Edward J. Kramer
  • Patent number: 4764320
    Abstract: Semipermeable membranes with improved permeation flux are prepared by contacting a glassy polymer in the form of a hollow fiber or film with a solvent in which the polymer swells at conditions which permit the swelling solvent to diffuse into the glassy polymer and then stretching the swollen polymer in an amount sufficient to cause visible stress whitening.
    Type: Grant
    Filed: June 12, 1987
    Date of Patent: August 16, 1988
    Assignee: The Dow Chemical Company
    Inventors: Chieh-Chun Chau, Lu H. Tung
  • Patent number: 4717749
    Abstract: A pressure sensitive adhesive composition is provided. The adhesive comprises an ABA block polymer wherein A represents a copolymer of styrene and alpha-methylstyrene and B represents blocks of diene polymer. The diene polymer can be butadiene, isoprene or a mixture thereof. The composition also contains a tackifying resin.
    Type: Grant
    Filed: August 22, 1985
    Date of Patent: January 5, 1988
    Assignee: The Dow Chemical Company
    Inventors: Raymond W. Tang, Lu H. Tung
  • Patent number: 4659784
    Abstract: ABA block copolymers containing N,N-disubstituted acrylamides in the A blocks and butadiene polymer in the B block provides thermoplastic elastomer adhesives or compatibilizing agents for polymer blends.
    Type: Grant
    Filed: June 27, 1986
    Date of Patent: April 21, 1987
    Assignee: The Dow Chemical Company
    Inventors: David Y. Chung, Lu H. Tung
  • Patent number: 4631314
    Abstract: Block copolymers having two or more blocks may be prepared from vinyl-substituted aromatic hydrocarbons and a mixed isomer mixture of 1,3-pentadiene. At least one block is polymerized from the cis and trans-isomer mixture of 1,3-pentadiene. The amount of the mixed isomer mixture of 1,3-pentadiene polymerized may be increased by including in the mixed isomer mixture a cis-isomer polymerization promoter.
    Type: Grant
    Filed: June 26, 1985
    Date of Patent: December 23, 1986
    Assignee: The Dow Chemical Company
    Inventors: Lu H. Tung, Jerald A. Griggs
  • Patent number: 4631313
    Abstract: An improved method for the polymerization of mixtures of mixed cis and trans-isomers of 1,3-pentadiene in the production of block copolymers. By continuously or incrementally adding a cis-isomer of 1,3-pentadiene polymerization promoter, using a hydrocarbon solvent with no aprotic solvents of a polar nature and not exceeding specified temperature ranges, the cis-isomer of 1,3-pentadiene is polymerized, resulting in a greater 1,3-pentadiene polymerization yield. The polymerization promoter is a vinyl-substituted aromatic monomer, for example styrene.
    Type: Grant
    Filed: June 26, 1985
    Date of Patent: December 23, 1986
    Assignee: The Dow Chemical Company
    Inventors: Lu H. Tung, Jerald A. Griggs
  • Patent number: 4595707
    Abstract: Membrane compositions useful in filtration and distillation applications are prepared by providing a glassy polymer composition (e.g., polystyrene) optionally having an amount of crosslinking and crazing the polymer composition in the presence of a monomer (e.g., methyl methacrylate) which can graft to said polymer composition. The membrane compositions so prepared comprise a microporous structure wherein the micropores can contain polymeric material. Alternatively, the surface region of the membrane composition and/or the surface region of the micropores has a polymeric material grafted thereto.
    Type: Grant
    Filed: February 11, 1985
    Date of Patent: June 17, 1986
    Assignee: The Dow Chemical Company
    Inventors: Kathleen M. McCreedy, Edward J. Kramer, Lu H. Tung
  • Patent number: 4585816
    Abstract: Block copolymers of the AB(BA).sub.n configuration are employed in the preparation of asphalt blend concentrates. Advantageously asphalt is blended with polymer solution from polymerization reactor and subsequently devolatilized.
    Type: Grant
    Filed: July 2, 1985
    Date of Patent: April 29, 1986
    Assignee: The Dow Chemical Company
    Inventors: John F. Vitkuske, Lu H. Tung
  • Patent number: 4525532
    Abstract: .alpha.-Methylstyrene-styrene copolymer is blended with an .alpha.-methylstyrene-styrene diene block copolymer or copolymers to provide impact resistant molding material.
    Type: Grant
    Filed: August 22, 1983
    Date of Patent: June 25, 1985
    Assignee: The Dow Chemical Company
    Inventors: Lu H. Tung, Grace Y. Lo, Jerald A. Griggs
  • Patent number: 4431777
    Abstract: Block copolymers are prepared having end blocks with random copolymer of styrene and/or alkyl substituted derivatives and alpha-methylstyrene ranges from 1:0.5 to 1:2.5, a central block of a polydiene polymer joins the terminal blocks. The block copolymers contain from 10 to 90 weight percent of polydiene, the remaining portion being of random (alkyl) styrene-alpha-methylstyrene copolymer. The polymers range from medium impact polystyrene type polymer of low polydiene content to thermoplastic elastomers of high polydiene content.
    Type: Grant
    Filed: November 17, 1982
    Date of Patent: February 14, 1984
    Assignee: The Dow Chemical Company
    Inventors: Lu H. Tung, Grace Y. Lo
  • Patent number: 4427837
    Abstract: Diene-styrene-.alpha.-methylstyrene block polymers are prepared by polymerization in excess .alpha.-methylstyrene with a lithium initiator wherein styrene-.alpha.-methylstyrene block is polymerized at a temperature from about 20.degree. centigrade to about 160.degree. centigrade with the ratio of styrene to .alpha.-methylstyrene being from about 50 to 1 to about 1 to 50.
    Type: Grant
    Filed: August 28, 1981
    Date of Patent: January 24, 1984
    Assignee: The Dow Chemical Company
    Inventors: Lu H. Tung, Grace Y-s. Lo
  • Patent number: 4409369
    Abstract: Styrene is polymerized employing a free radical initiator in the presence of a styrene-diene block copolymer of the AB or AB (BA).sub.n configuration to provide a polymer containing from about 15 to 30 weight percent diene units polymerized therein. The polymer contains polydiene domains in the form of rods and spheres having diameters of 50 nanometers or less.
    Type: Grant
    Filed: May 21, 1981
    Date of Patent: October 11, 1983
    Assignee: The Dow Chemical Company
    Inventors: Charles E. Lyons, Lu H. Tung