Patents by Inventor Larry Y. Yen
Larry Y. Yen 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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Publication number: 20140339722Abstract: A multilayer porous membrane formed of an extrudable polymer is provided. The membrane is formed by co-extruding at least two compositions, each of which comprises a heated porogen and polymer while in contact with each other under conditions to minimize or prevent unstable interfacial flow between extruded layers. In a preferred embodiment, the two compositions are different such that the layers have a different average pore size.Type: ApplicationFiled: May 12, 2014Publication date: November 20, 2014Applicant: Entegris, Inc.Inventors: Larry Y. Yen, Rajnikant B. Patel
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Patent number: 7347937Abstract: A filtration cartridge having a housing with an inlet and an outlet and a filtration membrane contained within the housing and located between the inlet and the outlet is described. The membrane is sealed in such a manner that all fluid must flow through the membrane between entering the inlet and leaving the outlet of the housing. The entire cartridge, housing, membrane and any other components are all formed of one or more perfluorinated thermoplastic resins. These resins preferably are PFA, MFA, FEP and blends thereof. The membrane may be in the form of hollow fibers, wound fibers such as in a depth filter, or a flat sheet which may be formed into various configurations such as spiral filters, pleated filters, spiral pleated filters, disks and the like. These cartridges provide an inert, high temperature and acid/oxidative chemical resistant filter having properties similar to that of PTFE resins.Type: GrantFiled: January 28, 2000Date of Patent: March 25, 2008Assignee: Entegris, Inc.Inventors: Kwok-Shun Cheng, Cha P. Doh, Larry Y. Yen, Rajnikant B. Patel, T. Dean Gates
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Patent number: 6977043Abstract: Hollow fiber membranes having a skinned surface on one diameter, and a porous surface on the opposite diameter are produced from perfluorinated thermoplastic polymers by extruding a heated solution of the polymer having a low critical solution temperature directly into a cooling bath to form the porous membrane by liquid-liquid phase separation. Extrusion can be conducted either vertically or horizontally. The hollow fiber membranes are useful as ultrafiltration membranes and as membrane contactors.Type: GrantFiled: March 17, 2004Date of Patent: December 20, 2005Assignee: Mykrolis CorporationInventors: Kwok-Shun Cheng, T. Dean Gates, Larry Y. Yen, Rajnikant B. Patel
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Patent number: 6921482Abstract: Hollow fiber membranes having a skinned surface on one diameter, and a porous surface on the opposite diameter arm produced from perfluorinated thermoplastic polymers by extruding a heated solution of the polymer having a lower critical solution temperature directly into a cooling bath to form the porous membrane by liquid-liquid phase separation. Extrusion can be conducted either vertically or horizontally. The hollow fiber membranes are useful as ultrafiltration membranes and as membrane contactors.Type: GrantFiled: January 27, 2000Date of Patent: July 26, 2005Assignee: Mykrolis CorporationInventors: Kwok-Shun Cheng, T. Dean Gates, Larry Y. Yen, Rajnikant B. Patel
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Publication number: 20040154986Abstract: Hollow fiber membranes having a skinned surface on one diameter, and a porous surface on the opposite diameter are produced from perfluorinated thermoplastic polymers by extruding a heated solution of the polymer having a low critical solution temperature directly into a cooling bath to form the porous membrane by liquid-liquid phase separation. Extrusion can be conducted either vertically or horizontally. The hollow fiber membranes are useful as ultrafiltration membranes and as membrane contactors.Type: ApplicationFiled: March 17, 2004Publication date: August 12, 2004Inventors: Kwok-Shun Cheng, T. Dean Gates, Larry Y. Yen, Rajnikant B. Patel
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Patent number: 5531899Abstract: A composite ultrahigh molecular weight polyethylene microporous membrane is provided having cation exchange capacity. The membrane is useful for removing metal ions from acidic aqueous solutions.Type: GrantFiled: June 6, 1995Date of Patent: July 2, 1996Assignee: Millipore Investment Holdings LimitedInventors: Larry Y. Yen, Ven Anantharaman, Bipin Parekh
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Patent number: 5032274Abstract: Microporous or open ultrafiltration poly (tetrafluoroethylene-co-perfluoro-(alkyl vinyl ether)) (PFA) or poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) film membrane or hollow fibers having open pores are formed from a melt blend of 10 to 35 weight percent of the PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and one or more surfaces of the shaped melt blend are coated with the solvent prior to phase separation of the melt blend. Coating the membrane with solvent during shaping results in membrane having larger pores on that membrane surface as compared to membranes not coated with solvent. The shaped melt blend is cooled to effect phase separation and crystallization of the PFA or FEP from the blend. The solvent is separated from the PFA or FEP by extraction and the porous PFA or FEP is heat set under restraint to prevent shrinkage.Type: GrantFiled: August 17, 1990Date of Patent: July 16, 1991Assignee: Millipore CorporationInventors: Larry Y. Yen, George Lopatin, Howard Malarkey, David Soane
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Patent number: 4990294Abstract: Microporous or open ultrafiltration poly (tetrafluoroethylene-co-perfluoro-(alkyl vinyl ether)) (PFA) or poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) film membrane or hollow fibers having open pores are formed from a melt blend of 10 to 35 weight percent of the PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and one or more surfaces of the shaped melt blend are coated with the solvent prior to phase separation of the melt blend. Coating the membrane with solvent during shaping results in membrane having larger pores on that membrane surface as compared to membranes not coated with solvent. The shaped melt blend is cooled to effect phase separation and crystallization of the PFA or FEP from the blend. The solvent is separated from the PFA or FEP by extraction and the porous PFA or FEP is heat set under restraint to prevent shrinkage.Type: GrantFiled: September 26, 1989Date of Patent: February 5, 1991Assignee: Millipore CorporationInventors: Larry Y. Yen, George Lopatin, Howard Malarkey, David Soane
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Patent number: 4906377Abstract: Microporous poly (tetrafluoroethylene-co-perfluoro (alkyl vinyl ether)) (PFA) or poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) membrane or hollow fibers are formed from a melt blend of 10 to 35 weight percent of PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and cooled to effect phase separation of the PFA or FEP from the blend. The solvent is removed from the PFA or FEP by extraction and the porous PFA or FEP is dried under restraint to prevent shrinkage.Type: GrantFiled: May 3, 1989Date of Patent: March 6, 1990Assignee: Millipore CorporationInventors: Larry Y. Yen, George Lopatin
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Patent number: 4902456Abstract: Microporous poly (tetrafluoroethylene-co-perfluoro (alkyl vinyl ether)) (PFA) or poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) membrane or hollow fibers are formed from a melt blend of 10 to 35 weight percent of PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and cooled to effect phase separation of the PFA or FEP from the blend. The solvent is removed from the PFA or FEP by extraction and the porous PFA or FEP is dried under restraint to prevent shrinkage.Type: GrantFiled: May 4, 1988Date of Patent: February 20, 1990Assignee: Millipore CorporationInventors: Larry Y. Yen, George Lopatin
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Patent number: 4874567Abstract: Microporous polypropylene membrane or hollow fibers is formed from a melt blend of 5 to 20 weight percent polypropylene and a solvent. The melt blend is shaped and cooled to effect solid phase separation of the polypropylene from the blend. The solvent is separated from the polypropylene by extraction and the porous polypropylene is dried under restraint to prevent shrinkage.Type: GrantFiled: April 24, 1987Date of Patent: October 17, 1989Assignee: Millipore CorporationInventors: George Lopatin, Larry Y. Yen, Randall R. Rogers
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Patent number: 4828772Abstract: Microporous membranes and methods for producing such membranes from ultrahigh molecular weight polyethylene are described. The method employs extrusion of a solution of UHMW-PE and porogen through a forming die followed by thermal phase separation of polymer and porogen. Microporous structures are created by removing porogen. Microporous membranes produced include membranes with good permeability to air and water making them particularly useful as filtration media and water-resistance breathable membranes.Type: GrantFiled: May 9, 1988Date of Patent: May 9, 1989Assignee: Millipore CorporationInventors: George Lopatin, Larry Y. Yen
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Patent number: 4778601Abstract: Microporous membranes and methods for producing such membranes from ultrahigh molecular weight polyethylene are described. The method employs extrusion of a solution of UHMW-PE and porogen through a forming die followed by thermal phase separation of polymer and porogen. Microporous structures are created by removing porogen. Microporous membranes produced include membranes with good permeability to air and water making them particularly useful as filtration media and water-resistant breathable membranes.Type: GrantFiled: October 9, 1984Date of Patent: October 18, 1988Assignee: Millipore CorporationInventors: George Lopatin, Larry Y. Yen