Patents by Inventor Pak-Wing S. Chum

Pak-Wing S. Chum 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: 6777082
    Abstract: The present invention relates to a fiber produced form a composition comprising at least one hydrogenated block copolymer and, optionally, at least one other polymer selected from the group consisting of a reactive tailored liquid polyurethane, an elastomeric or sulfonated ethylene/vinyl aromatic interpolymer, an elastomeric ethylene/C3-C20 &agr;-olefin interpolymer, an C3-C20 &agr;-olefin/conjugated diene interpolymer, an elastic polypropylene polymer, an enhanced polypropylene polymer, an elastomeric thermoplastic polyurethane, an elastic copolyester, a partially hydrogenated block copolymer, an elastic polyamide, a hydroxyl functionalized polyether (or polyetheramine), a styrene/conjugated diene interpolymer, and an elastomeric metallocene-catalyzed synthetic polymer or a blend or formulated system thereof.
    Type: Grant
    Filed: December 6, 2001
    Date of Patent: August 17, 2004
    Assignee: The Dow Chemical Company
    Inventors: Rajen M. Patel, Pak-Wing S. Chum, Stephen F. Hahn, Leonie K. Walsh, Rexford A. Maugans, Selim Bensason, Thoi H. Ho, Calvin P. Esneault
  • 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: 20040082750
    Abstract: Films with excellent machine direction (MD) tear properties comprise at least one layer made from a polymer comprising:
    Type: Application
    Filed: August 15, 2003
    Publication date: April 29, 2004
    Inventors: Li-Min Tau, Pak-Wing S. Chum, Seema Karande, Clive Bosnyak
  • Patent number: 6723398
    Abstract: This invention is directed to an ethylene polymer blend comprising at least two diverse ethylene interpolymers wherein one interpolymer has a lower number of carbons than the at least one other interpolymer. The ethylene polymer blend preferably comprises at least one homogeneously branched ethylene/&agr;-olefin interpolymer blended with at least one heterogeneously branched ethylene/&agr;-olefin interpolymer and is characterized as having a density greater than or equal to 0.90 g/cm3 and in particularly preferred embodiments is further characterized as having an intrinsic tear value greater than or equal to 150 grams. The inventive ethylene polymer blend can be used to make various fabricated articles, especially extruded forms and most especially films such as high strength thin gauge packaging film, impact resistant shrink film and heat sealable packaging film.
    Type: Grant
    Filed: November 1, 1999
    Date of Patent: April 20, 2004
    Assignee: Dow Global Technologies Inc.
    Inventors: Pak-Wing S. Chum, Kurt W. Swogger, Thomas Oswald, Pradeep J. Jain
  • Publication number: 20030194575
    Abstract: Films with excellent machine direction (MD) tear properties comprise at least one layer made from a polymer comprising:
    Type: Application
    Filed: November 5, 2002
    Publication date: October 16, 2003
    Inventors: Li-Min Tau, Pak-Wing S. Chum, Seema Karande, Clive Bosnyak
  • Patent number: 6593005
    Abstract: The present invention includes a coextruded film having at least two layers. The first layer contains a coupled propylene polymer and the second layer contains an in-reactor blend of a linear low density polyethylene fraction and a substantially linear polyethylene fraction. Alternatively, the second layer may include a homogeneously branched linear polyethylene. Preferably, the first layer makes up about 50 weight percent or less of the overall coextruded film structure. The first layer may also contain a polyethylene, such as a linear low density polyethylene, a low density polyethylene, a high density polyethylene, substantially linear polyethylene, a homogeneously branched linear polyethylene, an in-reactor blend of linear low density polyethylene and a substantially linear polyethyelene, and blends thereof.
    Type: Grant
    Filed: January 24, 2001
    Date of Patent: July 15, 2003
    Assignee: Dow Global Technologies Inc.
    Inventors: Li-Min Tau, Lisa S. Madenjian, Johan A. Thoen, Wendy D. Hoenig, Pak-Wing S. Chum, John Kaarto, Daniel J. Falla
  • Publication number: 20030114595
    Abstract: This invention relates to cast films prepared from interpolymer compositions comprising;
    Type: Application
    Filed: July 22, 2002
    Publication date: June 19, 2003
    Inventors: Jozef J.I. Van Dun, Jacquelyn A. deGroot, Pradeep Jain, Kalyan Sehanobish, Pak-Wing S. Chum
  • Publication number: 20030088021
    Abstract: Blend compositions containing a novel homopolymer, the use of which allows the incorporation of more comonomer in the additional components of the blend (for the same overall density) resulting in increased tie molecule formation and improvement in properties such as ESCR, toughness and impact strength are disclosed. The homopolymers are important for applications where a high density is needed to ensure certain mechanical properties like abrasion resistance, indentation resistance, pressure resistance, topload resistance, modulus of elasticity, or morphology (for the chlorination of PE to CPE) and additional advantages such as melt processability. The blend can be obtained by dry or melt mixing the already produced components, or through in-situ production by in parallel and/or in series arranged reactors. These resins can be used in applications such as films, blow molded, injection molded, and rotomolded articles, fibres, and cable and wire coatings and jacketings and, various forms of pipe.
    Type: Application
    Filed: June 13, 2002
    Publication date: May 8, 2003
    Applicant: The Dow Chemical Company
    Inventors: Jozef J. Van Dun, Akira Miyamoto, Grant B. Jacobsen, Fumio Matsushita, Schouterden J. Patrick, Spencer Lee, Pak-Wing S. Chum, Larry A. Meiske, Wauteraerts L. Peter
  • Publication number: 20030060529
    Abstract: The present invention relates to a method for making a heat-resistant elastic article and a heat-resistant elastic article. The invention especially relates to a method of making elastic fibers and polymeric elastic fibers wherein the elastic fibers are capable of withstanding dyeing and heat-setting processes that typically are conducted at elevated temperatures (such as 110-230° C. and especially at greater than or equal to 130° C. for minutes). The inventive method comprises radiation crosslinking an article (or plurality of articles) under an inert or oxygen limited atmosphere (for example, in N2, argon, helium, carbon dioxide, xenon and/or a vacuum) wherein the article (or articles) comprises at least one amine stabilizer and preferably another optional stabilizer additive. More preferably, the radiation crosslinking is performed at a low temperature (−50 to 40° C.).
    Type: Application
    Filed: July 10, 2002
    Publication date: March 27, 2003
    Inventors: Thoi H. Ho, Selim Bensason, Rajen M. Patel, Kimberly S. Houchens, Rona L. Reid, Pak-Wing S. Chum, Leonie K. Walsh
  • Publication number: 20030055176
    Abstract: A process for the preparation of blends including an ethylene copolymer by copolymerizing ethylene and at least one comonomer selected from a compound represented by the formula H2C═CHR wherein R is an alkyl group or an aryl group, and a diene, in the presence of a solid catalyst system comprising a support, a transition metal compound and an activator capable of converting the transition metal compound.
    Type: Application
    Filed: June 7, 2002
    Publication date: March 20, 2003
    Inventors: Grant B. Jacobsen, Jozef J. Van Dun, Pak-Wing S. Chum, Larry A. Meiske, Fumio Matsushita, Akira Miyamoto
  • Publication number: 20020156193
    Abstract: The present invention includes a composition comprising (a) at least one propylene polymer coupled by reaction with a coupling amount of poly(sulfonyl azide) sufficient to increase the melt strength of the propylene polymer before coupling at least about 1.5 fold as compared with the resulting coupled propylene polymer; and (b) at least one ethylene polymer wherein the ethylene polymer is present in an amount sufficient to improve film mechanical properties of tear resistance in either the machine direction (MD) and cross direction (CD) as measured by the Elmendorf Tear method (ASTM D-1922) or dart impact strength as measured by the procedure of ASTM D-1709 or a modified method thereof in which the height from which the dart is dropped is decreased from 26″ to 10.5″ (0.66 m to 0.27 m) as compared with a film formed in the same manner using the coupled propylene polymer of (a) alone.
    Type: Application
    Filed: April 12, 2002
    Publication date: October 24, 2002
    Inventors: Li-Min Tau, Wendy D. Hoenig, Lisa S. Madenjian, Pak-Wing S. Chum, John Kaarto, Johan A. Thoen
  • Publication number: 20020147273
    Abstract: The present invention relates to a fiber produced form a composition comprising at least one hydrogenated block copolymer and, optionally, at least one other polymer selected from the group consisting of a reactive tailored liquid polyurethane, an elastomeric or sulfonated ethylene/vinyl aromatic interpolymer, an elastomeric ethylene/C3-C20 &agr;-olefin interpolymer, an C3-C20 &agr;-olefin/conjugated diene interpolymer, an elastic polypropylene polymer, an enhanced polypropylene polymer, an elastomeric thermoplastic polyurethane, an elastic copolyester, a partially hydrogenated block copolymer, an elastic polyamide, a hydroxyl functionalized polyether (or polyetheramine), a styrene/conjugated diene interpolymer, and an elastomeric metallocene-catalyzed synthetic polymer or a blend or formulated system thereof.
    Type: Application
    Filed: December 6, 2001
    Publication date: October 10, 2002
    Inventors: Rajen M. Patel, Pak-Wing S. Chum, Stephen F. Hahn, Leonie K. Walsh, Rexford A. Maugans, Selim Bensason, Thoi H. Ho, Calvin P. Esneault
  • Patent number: 6451916
    Abstract: The present invention pertains to a continuous process and polymerization system characterized by separate injection of catalyst and make-up feed, an ethylene interpolymer composition characterized as having broad molecular weight distribution (MWD) and optimized compositional uniformity, a process for making such a composition and a fabricated article made from such composition. The novel composition is characterized as having a melt flow ratio, I10/I2, from 8 to 30, a Mw/Mn of greater than 4 as determined by gel permeation chromatography, a melt index, I2, from 0.01 to 1000 grams/10 minutes, preferably greater that 0.1 to 10 grams/10 minutes, and a density less than 0.945 g/cm3. The novel composition exhibits good processibility and improved toughness properties, especially excellent film tear and impact resistance, and is particularly well-suited for use in applications such as high performance trash can liners and heavy duty shipping bags.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: September 17, 2002
    Assignee: The Dow Chemical Company Midland
    Inventors: Kenneth W. Anderson, Pak-Wing S. Chum, David A. Eversdyk, Lonnie G. Hazlitt, Pradeep Jain, Kalyan Sehanobish, Li-Min Tau
  • Patent number: 6437014
    Abstract: The present invention relates to a method for making a heat-resistant elastic article and a heat-resistant elastic article. The invention especially relates to a method of making elastic fibers and polymeric elastic fibers wherein the elastic fibers are capable of withstanding dyeing and heat-setting processes that typically are conducted at elevated temperatures (such as 110-230° C. and especially at greater than or equal to 130° C. for minutes). The inventive method comprises radiation crosslinking an article (or plurality of articles) under an inert or oxygen limited atmosphere (for example, in N2, argon, helium, carbon dioxide, xenon and/or a vacuum) wherein the article (or articles) comprises at least one amine stabilizer and preferably another optional stabilizer additive. More preferably, the radiation crosslinking is performed at a low temperature (−50 to 40° C.).
    Type: Grant
    Filed: July 28, 2000
    Date of Patent: August 20, 2002
    Assignee: The Dow Chemical Company
    Inventors: Thoi H. Ho, Selim Bensason, Rajen M. Patel, Kimberly S. Houchens, Rona L. Reid, Pak-Wing S. Chum, Leonie K. Walsh
  • Publication number: 20010046606
    Abstract: The present invention includes a coextruded film having at least two layers. The first layer contains a coupled propylene polymer and the second layer contains an in-reactor blend of a linear low density polyethylene fraction and a substantially linear polyethylene fraction. Alternatively, the second layer may include a homogeneously branched linear polyethylene. Preferably, the first layer makes up about 50 weight percent or less of the overall coextruded film structure. The first layer may also contain a polyethylene, such as a linear low density polyethylene, a low density polyethylene, a high density polyethylene, substantially linear polyethylene, a homogeneously branched linear polyethylene, an in-reactor blend of linear low density polyethylene and a substantially linear polyethyelene, and blends thereof.
    Type: Application
    Filed: January 24, 2001
    Publication date: November 29, 2001
    Inventors: Li-Min Tau, Lisa S. Madenjian, Johan A. Thoen, Wendy D. Hoenig, Pak-Wing S. Chum, John Kaarto, Daniel J. Falla
  • Patent number: 6319989
    Abstract: The present invention pertains to a continuous process and polymerization system characterized by separate injection of catalyst and make-up feed, an ethylene interpolymer composition characterized as having broad molecular weight distribution (MWD) and optimized compositional uniformity, a process for making such a compostion and a fabricated article made from such composition. The novel composition is characterized as having a melt flow ratio, I10/I2, from 8 to 30, a Mw/Mn of greater than 4 as determined by gel permeation chromatography, a melt index, I2, from 0.01 to 1000 grams/10 minutes, preferably greater that 0.1 to 10 grams/10 minutes, and a density less than 0.945 g/cm3. The novel composition exhibits good processibility and improved toughness properties, especially excellent film tear and impact resistance, and is particularly well-suited for use in applications such as high performance trash can liners and heavy duty shipping bags.
    Type: Grant
    Filed: January 20, 2000
    Date of Patent: November 20, 2001
    Assignee: The Dow Chemical Company
    Inventors: Kenneth W. Anderson, Pak-Wing S. Chum, David A. Eversdyk, Lonnie G. Hazlitt, Pradeep Jain, Kalyan Sehanobish, Li-Min Tau
  • Patent number: 6319577
    Abstract: A sheet, film, fiber, foam or latex prepared from a blend of polymeric materials comprising a plurality of substantially random interpolymers comprising vinyl aromatic and ethylene and/or alpha olefin monomers and wherein: a) the amount of polymer units derived from said vinyl aromatic monomer in any interpolymer component differs from that amount in another interpolymer component by at least 0.5 mole percent; b) the amount of polymer units derived from said vinyl aromatic monomer in the blend is greater than about 19 mole percent; and wherein c) the observed stress relaxation of the resulting blend is greater than the additive stress relaxation of the of the individual blend components.
    Type: Grant
    Filed: November 17, 2000
    Date of Patent: November 20, 2001
    Assignee: The Dow Chemical Company
    Inventors: Martin J. Guest, John J. Gathers, Yunwa W. Cheung, Pak-Wing S. Chum
  • Patent number: 6270891
    Abstract: The subject invention is directed to polymer compositions having improved bond performance, to a method for improving the bond performance of a polymer composition, and to fabricated articles, such as fibers and fabrics which exhibit an improved bond performance, and to other fabricated articles, including but not limited to rotationally molded articles, prepared from polymer compositions of the invention.
    Type: Grant
    Filed: January 25, 2000
    Date of Patent: August 7, 2001
    Assignee: The Dow Chemical Company
    Inventors: Rexford A. Maugans, Ed N. Knickerbocker, Rebecca J. Sawchuk, Alan R. Whetten, Ronald P. Markovich, Pak-Wing S. Chum
  • Patent number: 6172173
    Abstract: A polymer produced by a transition metal containing catalyst useful for the polymerization of &agr;-olefins is prepared by (A) forming in an inert atmosphere which excludes oxygen and moisture a slurry of (1) a porous inorganic oxide support material selected from the group consisting of silica, alumina, or a combination of silica and alumina, said support material containing not greater than about 5 millimoles of hydroxyl groups per gram of support material and a particle size not greater than about 10 microns and a surface area of from about 50 to about 800 m2/g in an inert organic liquid medium; (B) mixing said slurry with (2) an alkoxide and stirring the resultant mixture at a temperature of from about −20° C. to about 120° C.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: January 9, 2001
    Assignee: The Dow Chemical Company
    Inventors: Lee Spencer, Brian W. S. Kolthammer, Miriam P. Ripplinger, Jeffrey J. Wooster, Pak-Wing S. Chum, Jacquelyn A. deGroot
  • Patent number: 6166145
    Abstract: Blends of polymeric materials comprising a plurality of substantially random interpolymers each interpolymer comprising:(1) from about 1 to about 65 mole percent of polymer units derived from either(a) at least one vinyl aromatic monomer or(b) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or(c) a combination of at least one vinyl aromatic monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, and(2) from about 35 to about 99 mole percent of polymer units derived from ethylene and/or at least one aliphatic alpha olefin having from 3 to 20 carbon atoms; and wherein:the amount of polymer units derived from vinyl aromatic monomer and/or aliphatic or cycloaliphatic vinyl or vinylidene monomer in any interpolymer component differs from that amount in another interpolymer component by at least 0.5 mole percent.These blends of interpolymer components give enhanced properties or processability when compared to the individual polymers comprising the blend.
    Type: Grant
    Filed: July 23, 1998
    Date of Patent: December 26, 2000
    Assignee: The Dow Chemical Company
    Inventors: Martin J. Guest, Yunwa W. Cheung, John J. Gathers, Pak-Wing S. Chum