Cellulose Diacetate Patents (Class 210/500.31)
  • Publication number: 20140091032
    Abstract: This invention relates to heterogenous pore polymer nanotube membranes useful in filtration, such as reverse osmosis desalination, nanofiltration, ultrafiltration and gas separation.
    Type: Application
    Filed: December 4, 2013
    Publication date: April 3, 2014
    Applicant: Nagare Membranes, LLC
    Inventors: Timothy V. Ratto, Jason K. Holt, Alan W. Szmodis
  • Patent number: 8511482
    Abstract: A method of producing a porous membrane, the method comprising: casting a polymer solution, in which a polymer is dissolved in a mixture of a good solvent, a poor solvent and a non-solvent, over a support, so as to form a casted polymer solution; drying the casted polymer solution, so as to form a cast film; and subjecting the cast film to a phase separation, wherein the porous membrane is produced under a condition where a temperature of a casted surface is lower than a temperature of the polymer solution, and each of a temperature change of the polymer solution and a temperature change of the casted surface is kept within ±3.0° C.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: August 20, 2013
    Assignee: Kurashiki Boseki Kabushiki Kaisha
    Inventors: Hideaki Tanaka, Yoshihiko Makino
  • Patent number: 7850858
    Abstract: This invention relates to a granulocyte adsorbent comprising a polymer compound having an unsubstituted hydroxyl group and a hydroxyl group in which H has been substituted with at least one substituent R, a method for producing such adsorbent, a device for adsorbing granulocytes and a system for removing granulocytes using such adsorbent, and body fluid or a cell suspension from which granulocytes have been removed using such adsorbent.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: December 14, 2010
    Assignee: Kaneka Corporation
    Inventors: Akira Kobayashi, Shinya Yoshida, Hideo Niwa
  • Publication number: 20090277837
    Abstract: The present invention discloses fluoropolymer coated membranes and methods for making and using these membranes. The fluoropolymer coated membranes described in the current invention are prepared by coating a porous asymmetric membrane layer with a thin layer of fluoropolymer coating. The porous asymmetric membrane layer comprises an asymmetric cellulosic membrane, an asymmetric polymer membrane, or an asymmetric molecular sieve/polymer mixed matrix membrane with a low selectivity and high permeance. The fluoropolymer coating improves the selectivity of the porous asymmetric membrane layer and maintains the membrane performance with time.
    Type: Application
    Filed: May 6, 2008
    Publication date: November 12, 2009
    Inventors: Chunqing Liu, Man-Wing Tang
  • Patent number: 7422686
    Abstract: There is disclosed a process for the production of cellulose hydrate ultrafiltration membranes having improved filtration performance and the ultrafiltration membranes produced by the process.
    Type: Grant
    Filed: November 1, 2005
    Date of Patent: September 9, 2008
    Assignee: Sartorius Stedim Biotech GmbH
    Inventors: Dietmar Nussbaumer, Hans-Heinrich Hörl
  • Patent number: 7381330
    Abstract: There is disclosed a cellulosic microporous filtration membrane with upper and lower porous protective layers with a porous sponge-type intermediate layer between the two protective layers, wherein the sponge-type structure consists of two isotropic regions having different pore sizes.
    Type: Grant
    Filed: June 8, 2004
    Date of Patent: June 3, 2008
    Assignee: Sartorius Stedim Biotech GmbH
    Inventors: Rebecca Petersen, Markus Hollas, Hans Beer, Manfred Bobbert
  • Patent number: 7153426
    Abstract: The invention relates to charged filtration membranes and their use for separation of a protein from solvent, low molecular weight solutes or a mixture of proteins. Modification of the membranes to generate charge includes modification of membrane pores to alter charge within a pore and alter the size of a pore. Consequently, the protein is separated from other solutes in a mixture based on size as well as net protein charge and membrane charge.
    Type: Grant
    Filed: September 29, 2005
    Date of Patent: December 26, 2006
    Assignee: Genentech, Inc.
    Inventor: Robert D. van Reis
  • Patent number: 6632366
    Abstract: The present invention relates to a cellulose compound hollow fiber membrane having high mechanical strength and is hardly degraded by microorganisms, wherein a cellulose compound is comprised as a membrane material, the thickness of the membrane is 50 to 500 &mgr;m, a dense membrane surface having an average pore diameter of 0.001 to 0.05 &mgr;m exists on the internal and/or external surface thereof, the inside of the membrane is composed of a three-dimensional network-like porous structure having voids with an average pore diameter of 0.05 to 2 &mgr;m, and 70% by weight or more of the membrane material is cellulose acetate propionate or cellulose acetate butyrate.
    Type: Grant
    Filed: May 12, 2000
    Date of Patent: October 14, 2003
    Assignee: Daicel Chemical Industries, Ltd.
    Inventors: Shuji Nakatsuka, Sachiko Matsuoka
  • Patent number: 6558546
    Abstract: A pore plugging material, for pH dependent membrane diffusion, in which cyclic olefins having phosphazene-functional moieties provide predictable erosion properties when used to plug pores in separation barriers and other porous membranes. Specific properties of the polymers are dependent on several factors, including molecular weight and identity of side groups attached to the phosphazene moiety. However, as a class, phosphazene-functional cyclic olefins provide both predictable erodibility and uniformly benign hydrolysis products and are, therefore, uniquely suitable as pore plugging polymers for separation barriers and membranes of all kinds. The invention, therefore, embraces the provision of a pH-sensitive erodible pore plugging material for pores in separation barriers and membranes of all kinds.
    Type: Grant
    Filed: November 1, 2001
    Date of Patent: May 6, 2003
    Assignee: The Penn State Research Foundation
    Inventors: Harry R. Allcock, Jared Bender, Roy H. Hammerstedt, Stephen Schwartz, Walter Laredo
  • Patent number: 6372136
    Abstract: To provide a cellulose acetate semipermeable membrane having a high filtration rate and high mechanical strength and which is hardly degraded by microorganisms, the present invention provides a cellulose acetate semipermeable membrane containing a cellulose acetate having an &agr;-cellulose content of not less than 99% by weight, a 6 wt/vol % viscosity of 20 to 220 mPa·s at 25±1° C. and an acetylation degree of 58 to 62%. The cellulose acetate semipermeable membrane is suitable particularly as a hollow fiber membrane.
    Type: Grant
    Filed: April 5, 2000
    Date of Patent: April 16, 2002
    Assignee: Daicel Chemical Industries, Ltd.
    Inventor: Shuji Nakatsuka
  • Patent number: 6358754
    Abstract: Novel solid phase reaction supports are disclosed. The solid phase reaction supports include (a) a solid phase carrier having a multiplicity of NH2 functional groups; (b) a coupling compound covalently bonded to an NH2 group of the solid phase carrier; and (c) a receptor compound coupled to the solid phase carrier through the coupling compound. The coupling compound is preferably ascorbic acid, dehydroascorbic acid or a diketo compound structurally similar to ascorbic acid or dehydroascorbic acid. The solid phase carrier is preferably made of cellulose.
    Type: Grant
    Filed: July 10, 1998
    Date of Patent: March 19, 2002
    Assignee: Forschungszentrum Julich GmbH
    Inventors: Peter Berlin, Jörg Tiller, Dieter Klemm
  • Patent number: 6350621
    Abstract: Novel solid phase reaction supports are disclosed. The solid phase reaction supports include (a) a solid phase carrier having a multiplicity of NH2 functional groups of the Formula (I): in which R1 and R2 are each H, or R1 is H and R2 is an alkyl or acyl substituent with a degree of substitution ≦1 or R1 is an alkyl or acyl substituent with a degree of substitution ≦1, and R2 is H, or R1 and R2 are each a substituent with a degree of substitution ≦2 and R3 is an aromatic substituent containing at least one free amino group having a substitution degree ≦1; (b) a coupling compound covalently bonded to an NH2 group of the solid phase carrier; and (c) a receptor compound coupled to the solid phase carrier through the coupling compound.
    Type: Grant
    Filed: April 25, 2000
    Date of Patent: February 26, 2002
    Assignee: Forshungszentrum Mulich GmbH
    Inventors: Peter Berlin, Jörg Tiller, Dieter Klemm