Patents by Inventor Pak-Wing Steve Chum
Pak-Wing Steve 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).
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Patent number: 6849704Abstract: Substantially linear olefin polymers having a melt flow ratio, I10/I2,?5.63, a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn?(I10/I2)?4.63, and a critical shear stress at onset of gross melt fracture of greater than about 4×106 dyne/cm2 and their method of manufacture are disclosed. The substantially linear olefin polymers preferably have at least about 0.01 long chain branches/1000 carbons and a molecular weight distribution from about 1.5 to about 2.5. The new polymers have improved processability over conventional olefin polymers and are useful in producing fabricated articles such as fibers, films, and molded parts.Type: GrantFiled: December 4, 2003Date of Patent: February 1, 2005Assignee: Dow Global Technologies Inc.Inventors: Shih-Yaw Lai, George W. Knight, John R. Wilson, James C. Stevens, Pak-Wing Steve Chum
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Patent number: 6737484Abstract: Substantially linear olefin polymers having a melt flow ratio, I10/I2, ≧5.63, a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn≦(I10/I2)−4.63, and a critical shear stress at onset of gross melt fracture of greater than about 4×106 dyne/cm2 and their method of manufacture are disclosed. The substantially linear olefin polymers preferably have at least about 0.01 long chain branches/1000 carbons and a molecular weight distribution from about 1.5 to about 2.5. The new polymers have improved processability over conventional olefin polymers and are useful in producing fabricated articles such as fibers, films, and molded parts.Type: GrantFiled: October 11, 2002Date of Patent: May 18, 2004Assignee: Dow Global Technologies Inc.Inventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens, Pak-Wing Steve Chum
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Publication number: 20040082741Abstract: Substantially linear olefin polymers having a melt flow ratio, I10/I2, ≧5.63, a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn≦(I10/I2)−463, and a critical shear stress at onset of gross melt fracture of greater than about 4×106 dyne/cm2 and their method of manufacture are disclosed. The substantially linear olefin polymers preferably have at least about 0.01 long chain branches/1000 carbons and a molecular weight distribution from about 1.5 to about 2.5. The new polymers have improved processability over conventional olefin polymers and are useful in producing fabricated articles such as fibers, films, and molded parts.Type: ApplicationFiled: December 4, 2003Publication date: April 29, 2004Inventors: Shih-Yaw Lai, George W. Knight, John R. Wilson, James C. Stevens, Pak-Wing Steve Chum
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Patent number: 6689851Abstract: The subject invention is directed to a rheology-modified ethylene polymer having less than 0.5 weight percent gel, a composition distribution breadth index (CDBI) greater than 50 percent, and a molecular weight distribution (Mw/Mn) of less than 4.0, which is characterized as having improved rheological performance and/or melt strength attributes relative to the unmodified polymer. The subject invention is further directed to polymer blends which comprise the rheology-modified polymers, and to a process for preparing the rheology-modified polymers.Type: GrantFiled: July 11, 2000Date of Patent: February 10, 2004Assignee: Dow Global Technologies Inc.Inventors: Michael E. Rowland, Robert R. Turley, James J. Hill, Lawrence T. Kale, Kyle G. Kummer, Shih-Yaw Lai, Pak-Wing Steve Chum
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Publication number: 20030120004Abstract: Substantially linear olefin polymers having a melt flow ratio, I10/I2, ≧5.63, a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn≦(I10/I2)−4.63, and a critical shear stress at onset of gross melt fracture of greater than about 4×106 dyne/cm2 and their method of manufacture are disclosed. The substantially linear olefin polymers preferably have at least about 0.01 long chain branches/1000 carbons and a molecular weight distribution from about 1.5 to about 2.5. The new polymers have improved processability over conventional olefin polymers and are useful in producing fabricated articles such as fibers, films, and molded parts.Type: ApplicationFiled: October 11, 2002Publication date: June 26, 2003Inventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens, Pak-Wing Steve Chum
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Patent number: 6548611Abstract: Substantially linear olefin polymers having a melt flow ratio, I10/I2, ≧5.63, a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn≦(I10/I2)−4.63, and a critical shear stress at onset of gross melt fracture of greater than about 4×106 dyne/cm2 and their method of manufacture are disclosed. The substantially linear olefin polymers preferably have at least about 0.01 long chain branches/1000 carbons and a molecular weight distribution from about 1.5 to about 2.5. The new polymers have improved processability over conventional olefin polymers and are useful in producing fabricated articles such as fibers, films, and molded parts.Type: GrantFiled: June 19, 2001Date of Patent: April 15, 2003Assignee: Dow Global Technologies Inc.Inventors: Shih-Yaw Lai, George W. Knight, John R. Wilson, James C. Stevens, Pak-Wing Steve Chum
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Publication number: 20010041776Abstract: Substantially linear olefin polymers having a melt flow ratio, I10/I2, ≧5.63, a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn≦(I10/I2)−4.63, and a critical shear stress at onset of gross melt fracture of greater than about 4×106 dyne/cm2 and their method of manufacture are disclosed. The substantially linear olefin polymers preferably have at least about 0.01 long chain branches/1000 carbons and a molecular weight distribution from about 1.5 to about 2.5. The new polymers have improved processability over conventional olefin polymers and are useful in producing fabricated articles such as fibers, films, and molded parts.Type: ApplicationFiled: June 19, 2001Publication date: November 15, 2001Inventors: Shih-Yaw Lai, George W. Knight, John R. Wilson, James C. Stevens, Pak-Wing Steve Chum
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Patent number: 6316549Abstract: Fibers made from formulated ethylene polymer compositions are disclosed. The ethylene polymer compositions have at least one homogeneously branched linear ethylene/&agr;-olefin interpolymer and at least one heterogeneously branched ethylene polymer. The homogeneously branched linear ethylene/&agr;-olefin interpolymer has a density from about 0.905 to about 0.92 g/cm3 and a slope of strain hardening coefficient greater than or equal to about 1.3.Type: GrantFiled: November 26, 1997Date of Patent: November 13, 2001Assignee: The Dow Chemical CompanyInventors: Pak-Wing Steve Chum, Ronald P. Markovich, George W. Knight, Shih-Yaw Lai
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Patent number: 6140420Abstract: Melt processible thermoplastic compositions and method for making them are described, these compositions comprising a thermoplastic polymer resin matrix selected from the group consisting of thermoplastic polyurethanes, polyvinyl chlorides, styrenics, engineering thermoplastics, and polyolefins, at least about 25 percent (by weight based on the total composition) of an elastomeric impact modifier dispersed as discrete particles in the thermoplastic matrix (a); and at least about 10 percent (by weight based on the total composition) of at least one homogeneous linear or substantially linear ethylene polymer dispersed as discrete particles in at least the impact modifier (b), the ethylene polymer having a molecular weight distribution less than 3.5 and a density of at least 0.04 g/cm.sup.3 higher than the density of the impact modifier component (b), wherein the elastic modulus of the thermoplastic component (a) is at least 200 times greater than the elastic modulus of the impact modifier component (b).Type: GrantFiled: December 1, 1998Date of Patent: October 31, 2000Assignee: The Dow Chemical CompanyInventors: Kalyan Sehanobish, Larry A. Meiske, Shaofu Wu, Pak-Wing Steve Chum
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Patent number: 6114486Abstract: The subject invention is directed to a rheology-modified ethylene polymer having less than 0.5 weight percent gel, a composition distribution breadth index (CDBI) greater than 50 percent, and a molecular weight distribution (M.sub.w /M.sub.n) of less than 4.0, which is characterized as having improved rheological performance and/or melt strength attributes relative to the unmodified polymer. The subject invention is further directed to polymer blends which comprise the rheology-modified polymers, and to a process for preparing the rheology-modified polymers.Type: GrantFiled: February 28, 1997Date of Patent: September 5, 2000Assignee: The Dow Chemical CompanyInventors: Michael E. Rowland, Robert R. Turley, James J. Hill, Lawrence T. Kale, Kyle G. Kummer, Shih-Yaw Lai, Pak-Wing Steve Chum
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Patent number: 6111023Abstract: Fabricated articles made from formulated ethylene polymer compositions are disclosed. Films made from such formulated compositions have surprisingly good impact and tensile properties, and an especially good combination of modulus and toughness. The ethylene polymer compositions have at least one homogeneously branched substantially linear ethylene/.alpha.-olefin interpolymer and at least one heterogeneously branched ethylene polymer. The homogeneously branched substantially linear ethylene/.alpha.-olefin interpolymer has a density from about 0.89 to about 0.92 g/cm.sup.3 and a slope of strain hardening coefficient greater than or equal to about 1.3.Type: GrantFiled: August 27, 1997Date of Patent: August 29, 2000Assignee: The Dow Chemical CompanyInventors: Pak-Wing Steve Chum, George W. Knight, Ronald P. Markovich, Shih-Yaw Lai
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Patent number: 6060567Abstract: Interpolymers having long chain branches are claimed. These interpolymers are made by continuous polymerization processes, including a process comprising the steps of: (a) contacting ethylene and at least one C.sub.3 -C.sub.20 alpha-olefin with a catalyst composition in a polymerization reactor under continuous polymerization conditions in a polymerization reactor, wherein said catalyst composition is made from components comprising:(1) a metal coordination complex comprising a metal atom of groups 3-10 or the Lanthanide series of the Periodic Table of Elements and a cyclic, delocalized .pi.-bonded moiety and(2) an activating cocatalyst; and(b) removing the interpolymer having long chain branches via a reactor exit stream. The interpolymers comprise ethylene with at least one C.sub.3 -C.sub.20 alpha-olefin and have a variety of properties, including from 0.01 to 3 long chain branches per thousand carbons, a melt flow ratio I.sub.10 /I.sub.2 .gtoreq.5.63, and a molecular weight distribution, M.sub.w /M.sub.Type: GrantFiled: December 6, 1996Date of Patent: May 9, 2000Assignee: The Dow Chemical CompanyInventors: Shih-Yaw Lai, John R. Wilson, George W. Knight, James C. Stevens, Pak-Wing Steve Chum
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Patent number: 5861463Abstract: Melt processible thermoplastic compositions and method for making them are described, these compositions comprising a) a polypropylene matrix, b) at least about 25 percent (by weight based on the total composition) of an elastomeric impact modifier dispersed as discrete particles in the polypropylene matrix (a); and c) at least about 10 percent (by weight based on the total composition) of at least one homogeneous linear or substantially linear ethylene polymer dispersed as discrete particles in at least the impact modifier (b), the ethylene polymer having a molecular weight distribution less than 3.5 and a density of at least 0.04 g/cm.sup.3 higher than the density of the impact modifier component (b), wherein the elastic modulus of the polypropylene (a) is at least 200 times greater than the elastic modulus of the impact modifier component (b).These thermoplastic compositions have improved processability. Processes for fabricating articles from them are described.Type: GrantFiled: October 31, 1996Date of Patent: January 19, 1999Assignee: The Dow Chemical CompanyInventors: Kalyan Sehanobish, Shaofu Wu, Larry A. Meiske, Pak-Wing Steve Chum
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Patent number: 5852152Abstract: Biaxially oriented, heat-shrinkable film-making process and film with improved toughness and extrusion processibility are disclosed. The improved film comprises at least one layer of at least one substantially linear ethylene homopolymer or interpolymer, wherein the substantially linear ethylene polymer has an uniform branching distribution, and is also characterized as having essentially no linear polymer fraction, a single DSC melting peak, a density greater than about 0.85 g/cc, and a simple bubble film 1% secant modulus below 195,000 kPa. The biaxially oriented film is characterized as having a simple bubble shrinkage value of from about 18% to about 85% at 135.degree. C. and is useful in preparing heat-shrink bags for packaging food articles like poultry and fresh red meat.Type: GrantFiled: June 7, 1995Date of Patent: December 22, 1998Assignee: The Dow Chemical CompanyInventors: Kim L. Walton, Rajen M. Patel, Pak-Wing Steve Chum
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Patent number: 5847053Abstract: Fabricated articles made from formulated ethylene polymer compositions are disclosed. Films made from such formulated compositions have surprisingly good impact and tensile properties, and an especially good combination of modulus and toughness. The ethylene polymer compositions have at least one homogeneously branched substantially linear ethylene/.alpha.-olefin interpolymer and at least one heterogeneously branched ethylene polymer. The homogeneously branched substantially linear ethylene/.alpha.-olefin interpolymer has a density from about 0.89 to about 0.92 g/cm.sup.3 and a slope of strain hardening coefficient greater than or equal to about 1.3.Type: GrantFiled: April 11, 1997Date of Patent: December 8, 1998Assignee: The Dow Chemical CompanyInventors: Pak-Wing Steve Chum, Ronald P. Markovich, George W. Knight, Shih-Yaw Lai
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Patent number: 5685128Abstract: Food products, especially fresh food products such as retail-cut red meat, vegetables and fruits, are packaged with a film having at least one film layer comprising a substantially linear ethylene polymer, preferably a polymer comprising ethylene and at least one .alpha.-olefin comonomer, e.g. 1-octene. The ethylene polymers used in the construction of the film structures used in this invention are prepared by constrained geometry catalyst technology. The film structures can be either mono- or multilayered, oriented or nonoriented, oxygen permeable or impermeable, and prepared by any conventional technique. The food products can be packaged by any conventional method, e.g. stretch overwrap, shrink, vacuum skin, on vacuum forming.Type: GrantFiled: May 31, 1995Date of Patent: November 11, 1997Assignee: The Dow Chemical CompanyInventors: Pak-Wing Steve Chum, Nicole F. Whiteman
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Patent number: 5677383Abstract: Fabricated articles made from formulated ethylene polymer compositions are disclosed. Films made from such formulated compositions have surprisingly good impact and tensile properties, and an especially good combination of modulus and toughness. The ethylene polymer compositions have at least one homogeneously branched substantially linear ethylene/.alpha.-olefin interpolymer and at least one heterogeneously branched ethylene polymer. The homogeneously branched substantially linear ethylene/.alpha.-olefin interpolymer has a density from about 0.89 to about 0.92 g/cm.sup.3 and a slope of strain hardening coefficient greater than or equal to about 1.3.Type: GrantFiled: October 18, 1995Date of Patent: October 14, 1997Assignee: The Dow Chemical CompanyInventors: Pak-Wing Steve Chum, Ronald P. Markovich, George W. Knight, Shih-Yaw Lai