Patents by Inventor Yunwa Wilson Cheung

Yunwa Wilson Cheung 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: 7579407
    Abstract: A unique thermoplastic olefin composition having: (a) at least 40 percent by weight of a propylene-alpha olefin copolymer based on the total weight of polymers in the composition, the propylene-alpha olefin copolymer having at least 60 percent by weight units derived from propylene, at least 6 percent by weight units derived from an alpha olefin, a molecular weight distribution less than 3.5, and a broad composition distribution; and (b) at least 20 percent by weight of a polypropylene based on the total weight of polymers in the composition, the polypropylene having at least 93 percent by weight units derived from propylene, a molecular weight distribution of greater than 3.5, a heat of fusion greater than the heat of fusion exhibited by the propylene-alpha olefin copolymer, and a melting point Tmax of at least 120° C.
    Type: Grant
    Filed: May 3, 2003
    Date of Patent: August 25, 2009
    Assignee: Dow Global Technologies Inc.
    Inventors: Li-Min Tau, Yunwa Wilson Cheung, Charles F. Diehl, Lonnie G. Hazlitt
  • Publication number: 20090123728
    Abstract: The present invention relates to compositions comprising blends of alkenyl aromatic polymers such as styrenic polymers (i.e. PS and HIPS) and bio-based or biodegradable polymers (i.e. PLA, PGA, PHA, PBS, PCL) compatibilized with styrene-based copolymers (i.e. styrene-ethylene-butylene-styrene (SEBS) block copolymers, maleated SEBS, styrene-maleic anhydride (SMA) copolymer, styrene-methyl methacrylate (SMMA) copolymer) or a mixture of two or more styrene-based copolymers such as SEBS and SMA. These novel compositions can be extruded and thermoformed to produce very low density food service and consumer foam articles such as plates, hinged lid containers, trays, bowls, and egg cartons with good mechanical properties.
    Type: Application
    Filed: February 2, 2009
    Publication date: May 14, 2009
    Applicant: PACTIV CORPORATION
    Inventors: Yunwa Wilson Cheung, David V. Dobreski, Richard Turner, Mark Wheeler, Y. Paul Handa
  • Publication number: 20090068427
    Abstract: The invention is an article comprising at least two layers, a low crystallinity layer and a high crystallinity layer. One or both layers is capable of being elongated so that a pre-stretched article is capable of being formed.
    Type: Application
    Filed: October 25, 2006
    Publication date: March 12, 2009
    Applicant: Dow Global Technologies Inc.
    Inventors: Rajen M. Patel, Andy C. Chang, Hong Peng, Seema V. Karande, Benjamin C. Poon, Yunwa Wilson Cheung
  • Patent number: 7498282
    Abstract: The invention is an article comprising at least two layers, a low crystallinity layer and a high crystallinity layer. One or both layers is capable of being elongated so that a pre-stretched article is capable of being formed.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: March 3, 2009
    Assignee: Dow Global Technology Inc.
    Inventors: Rajen M. Patel, Andy C. Chang, Hong Peng, Seema V. Karande, Benjamin C. Poon, Yunwa Wilson Cheung
  • Patent number: 7459500
    Abstract: A unique thermoplastic olefin composition having: (a) at least 40 percent by weight of a propylene-alpha olefin copolymer based on the total weight of polymers in the composition, the propylene-alpha olefin copolymer having at least 60 percent by weight units derived from propylene, at least 6 percent by weight units derived from an alpha olefin, a molecular weight distribution less than 3.5, and a broad composition distribution; and (b) at least 20 percent by weight of a polypropylene based on the total weight of polymers in the composition, the polypropylene having at least 93 percent by weight units derived from propylene, a molecular weight distribution of greater than 3.5, a heat of fusion greater than the heat of fusion exhibited by the propylene-alpha olefin copolymer, and a melting point Tmax of at least 120° C.
    Type: Grant
    Filed: May 5, 2003
    Date of Patent: December 2, 2008
    Assignee: Dow Global Technologies Inc.
    Inventors: Li-Min Tau, Yunwa Wilson Cheung, Charles F. Diehl, Lonnie G. Hazlitt
  • Publication number: 20070219334
    Abstract: Embodiments of the invention provide a class of propylene/?-olefin block interpolymers. The propylene/?-olefin interpolymers are characterized by an average block index, ABI, which is greater than zero and up to about 1.0 and a molecular weight distribution, Mw/Mn, greater than about 1.3. Preferably, the block index is from about 0.2 to about 1. In addition or alternatively, the block propylene/?-olefin interpolymer is characterized by having at least one fraction obtained by Temperature Rising Elution Fractionation (“TREF”), wherein the fraction has a block index greater than about 0.3 and up to about 1.0 and the propylene/?-olefin interpolymer has a molecular weight distribution, Mw/Mn, greater than about 1.3.
    Type: Application
    Filed: March 15, 2007
    Publication date: September 20, 2007
    Applicant: Dow Global Technologies Inc.
    Inventors: Colin Li Pi Shan, Lonnie G. Hazlitt, Yunwa Wilson Cheung, Benjamin C. Poon, Phillip D. Hustad, Roger L. Kuhlman, Edmund M. Carnahan, XiaoHua Qiu, Angela N. Taha
  • Publication number: 20040242784
    Abstract: A unique thermoplastic olefin composition having: (a) at least 40 percent by weight of a propylene-alpha olefin copolymer based on the total weight of polymers in the composition, the propylene-alpha olefin copolymer having at least 60 percent by weight units derived from propylene, at least 6 percent by weight units derived from an alpha olefin, a molecular weight distribution less than 3.5, and a broad composition distribution; and (b) at least 20 percent by weight of a polypropylene based on the total weight of polymers in the composition, the polypropylene having at least 93 percent by weight units derived from propylene, a molecular weight distribution of greater than 3.5, a heat of fusion greater than the heat of fusion exhibited by the propylene-alpha olefin copolymer, and a melting point Tmax of at least 120° C.
    Type: Application
    Filed: May 3, 2003
    Publication date: December 2, 2004
    Inventors: Lin-Min Tau, Yunwa Wilson Cheung, Charles F. Diehl, Lonnie G. Hazlitt
  • Publication number: 20040106739
    Abstract: The present invention pertains to immiscible blends of two or more &agr;-olefin/vinyl aromatic monomer interpolymers, the blend having at least one interpolymer component which comprises 2 to 7 mole percent vinyl aromatic monomer content, and uses for such blends. The blend components are selected to provide superior processability and/or performance, such as upper use temperature, in the blend compositions and in their end use applications.
    Type: Application
    Filed: September 5, 2003
    Publication date: June 3, 2004
    Inventors: Yunwa Wilson Cheung, Samuel Ethiopia, Martin James Guest, Pak-Wing S. Chum
  • Publication number: 20040087751
    Abstract: A unique thermoplastic olefin composition having: (a) at least 40 percent by weight of a propylene-alpha olefin copolymer based on the total weight of polymers in the composition, the propylene-alpha olefin copolymer having at least 60 percent by weight units derived from propylene, at least 6 percent by weight units derived from an alpha olefin, a moleculare weight distribution less than 3.5, and a broad composition distribution; and (b) at least 20 percent by weight of a polypropylene based on the total weight of polymers in the composition, the polypropylene having at least 93 percent by weight units derived from propylene, a molecular weight distribution of greater than 3.5, a heat of fusion greater than the heat of fusion exhibited by the propylene-alpha olefin copolymer, and a melting point Tmax of at least 120° C.
    Type: Application
    Filed: May 5, 2003
    Publication date: May 6, 2004
    Inventors: Li-Min Tau, Yunwa Wilson Cheung, Charles F. Diehl, Lonnie G. Hazlitt
  • Patent number: 6476141
    Abstract: A blend composition (and fabricated articles therefrom) comprising; (A) one or more alkenyl aromatic polymers; (B) one or more substantially random interpolymers comprising (1) polymer units derived from; (a) at least one vinyl or vinylidene aromatic monomer, or (b) at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, or (c) a combination of at least one aromatic vinyl or vinylidene monomer and at least one hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, and (2) polymer units derived from at least one of ethylene and/or a C3-20 &agr;-olefin; and (3) polymer units derived from one or more of ethylenically unsaturated polymerizable monomers other than those derived from (1) and (2); and, (C) one or more compatibilizers; and wherein said blend has; a) a tensile strength greater than 1500 psi; b) a pull force test (⅛″ diameter) greater than 15 lb; c) a Shore A Hardness greater than 79; d) a cycle time in injection molding of less than 30 sec.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: November 5, 2002
    Assignee: Dow Global Technologies Inc.
    Inventors: Dane Chang, Yunwa Wilson Cheung, Charles F. Diehl, Martin J. Guest, Bharat I. Chaudhary, Andre J. Uzee
  • Publication number: 20020161125
    Abstract: A blend composition (and fabricated articles therefrom) comprising;
    Type: Application
    Filed: September 27, 2001
    Publication date: October 31, 2002
    Inventors: Dane Chang, Yunwa Wilson Cheung, Charles F. Diehl, Martin J. Guest, Bharat I. Chaudhary, Andre J. Uzee
  • Patent number: 6103803
    Abstract: A filled polymer composition which comprisesA) from about 5 to about 90 percent of one or more thermoplastic substantially random interpolymers prepared by polymerizing one or more a-olefin monomers with one or more vinylidene aromatic monomers and/or one or more hindered aliphatic or cycloaliphatic vinylidene monomers, and optionally with other polymerizable ethylenically unsaturated monomer(s), and(B) from about 10 to about 95 percent of one or more inorganic fillers,the amounts of (A) and (B) being based on the total weight of (A) and (B).Fabricated articles made from the filled polymer compositions are useful as sound insulating or energy absorbing films or sheets or as floor, wall or ceiling coverings.
    Type: Grant
    Filed: June 8, 1999
    Date of Patent: August 15, 2000
    Assignee: The Dow Chemical Company
    Inventors: Yunwa Wilson Cheung, John O. Bieser, Martin James Guest, Johan A. Thoen, John Joseph Gathers
  • Patent number: 5973049
    Abstract: A filled polymer composition which comprises(A) from about 5 to about 90 percent of one or more thermoplastic substantially random interpolymers prepared by polymerizing one or more .alpha.-olefin monomers with one or more vinylidene aromatic monomers and/or one or more hindered aliphatic or cycloaliphatic vinylidene monomers, and optionally with other polymerizable ethylenically unsaturated monomer(s), and(B) from about 10 to about 95 percent of one or more inorganic fillers,the amounts of (A) and (B) being based on the total weight of (A) and (B).Fabricated articles made from the filled polymer compositions are useful as sound insulating or energy absorbing films or sheets or as floor, wall or ceiling coverings.
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: October 26, 1999
    Assignee: The Dow Chemical Company
    Inventors: John O. Bieser, Yunwa Wilson Cheung, Martin James Guest, Johan A. Thoen, John Joseph Gathers