Regenerated Cellulose Patents (Class 536/57)
  • Patent number: 5484913
    Abstract: A calcium-modified oxidized cellulose hemostat provides faster hemostasis than does either unmodified or sodium- or potassium-modified oxidized cellulose. The percentage by weight of calcium in the modified oxidized cellulose must be in a range between about 0.5 and about 4, in order to enhance hemostasis, while not interfering excessively with bioabsorbability. In a second embodiment, an oxidized cellulose hemostat is modified with both calcium and either sodium or potassium. The second embodiment may be used to deliver acid-sensitive materials.
    Type: Grant
    Filed: March 24, 1995
    Date of Patent: January 16, 1996
    Assignee: Johnson & Johnson Medical, Inc.
    Inventors: Reginald L. Stilwell, Elaine J. Whitmore, Lowell G. Saferstein
  • Patent number: 5424417
    Abstract: The invention relates to the prehydrolysis of lignocellulose by passing an acidic or alkaline solution through solid lignocellulosic particles with removal of soluble components as they are formed. The technique permits a less severe combination of pH, temperature and time than conventional prehydrolysis. Furthermore, greater extraction of both hemicellulose and lignin occurs simultaneously in the same reactor and under the same conditions.
    Type: Grant
    Filed: September 24, 1993
    Date of Patent: June 13, 1995
    Assignee: Midwest Research Institute
    Inventors: Robert W. Torget, Kiran L. Kadam, Teh-An Hsu, George P. Philippidis, Charles E. Wyman
  • Patent number: 5410034
    Abstract: The present invention provides a cellulose solution prepared by dissolving a cellulose which has not previously been subject to explosive disruption at atmospheric pressures in an aqueous alkali solution which can be shaped into a fiber, film or other article or applied to the surface or treatment of other materials by coating, dipping, or other suitable methods.
    Type: Grant
    Filed: February 24, 1994
    Date of Patent: April 25, 1995
    Assignee: The United States of America as represented by the Secretary of Agriculture
    Inventors: Akira Isogai, Rajai H. Atalla
  • Patent number: 5403530
    Abstract: An elongate member of cellulosic material, such as fiber, having a reduced tendency to fibrillation is produced by a solvent-spinning process which includes the steps of: (i) dissolving cellulose in a solvent miscible with water to produce a dope; (ii) forcing the dope through at least one orifice to produce an elongate form; (iii) passing the elongate form through at least one water-containing bath to remove the solvent and produce the elongate member, and (iv) drying the elongate member to produce a dry elongate member, and is characterized in that the pH of each of the baths through which the elongate form and the elongate member pass during processing between production of the elongate form and the drying of the elongate member is maintained at a figure of 8.5 or less.
    Type: Grant
    Filed: July 20, 1993
    Date of Patent: April 4, 1995
    Assignee: Courtaulds PLC
    Inventor: James M. Taylor
  • Patent number: 5362867
    Abstract: An improved method of making cellulose yarn solution made up of solvents such as N-methylmorpholine-N-oxide and recovered caprolactam involves cutting a wood pulp sheet into small pieces, which are subsequently added into a kneading machine having therein water solution containing 63-67% of N-methylmorpholine-N-oxide and recovered caprolactam. The kneading machine is subjected to a three-stage heat treatment to produce the cellulose yarn solution at low cost and best qualities.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: November 8, 1994
    Assignee: Formosa Chemicals & Fibre Corporation
    Inventors: Hui-Ching Chin, Yuan-Tsung Chen, Guo-Jane Cheng
  • Patent number: 5352730
    Abstract: The present invention relates to a coating compound for sheets, films, or molded products composed of modified or unmodified polysaccharides.
    Type: Grant
    Filed: June 5, 1992
    Date of Patent: October 4, 1994
    Assignee: Wolff Walstrode AG
    Inventors: Erhard Luhmann, Burkhard Kressdorf, Lutz Hoppe, Klaus Szablikowski, Gunter Weber, Sebastian Meyer-Stork
  • Patent number: 5328603
    Abstract: Improved cellulosic beads for use as supports in bioaffinity chromatography are produced by dissolution of cellulose in a chaotropic cellulose solvent, formation of the dissolved cellulose into droplets, and immersion of the droplets into a non-solvent capable of solvent interchange with the cellulose solvent to form generally spherical porous cellulose beads of narrow particle size distribution. The beads formed are preferably made with cellulose having a degree of polymerization between 100 and 200, and the resulting beads when saturated with water without drying contain between 1% and 7% cellulose by weight and have a particle size of at least about 0.3 mm. The beads can be activated by a suitable activation method, and specific bioaffinity ligands are bound to the active sites in the beads. The beads reacted ligands, the beads then used in bioaffinity chromatography to isolate specific bioaffinity molecules having molecular weights between 5,000 and 500,000 from complex solutions.
    Type: Grant
    Filed: August 19, 1992
    Date of Patent: July 12, 1994
    Assignee: The Center for Innovative Technology
    Inventors: William H. Velander, Jeffrey A. Kaster, Wolfgang G. Glasser
  • Patent number: 5298615
    Abstract: An ultra-lightweight, open-pore foamed cellulose material with an increased surface area, having ion exchangeable functional groups introduced in it. The cellulose material presents a three-dimensional network structure which, upon swollen, has a particle diameter of 0.8 to 12.0 mm, a mean pore diameter of 0.1 to 1.7 mm, a specific surface area of 1.0 to 10.0 m.sup.2 /g, a true density of 1.4 to 1.6 g/cm.sup.3 and a porosity of 90% or greater. The ion exchangeable functional groups, for instance, may be cationic polyethyleneimine.
    Type: Grant
    Filed: April 5, 1991
    Date of Patent: March 29, 1994
    Assignees: Sakai Engineering Co., Ltd., Agro-Systems Corporation Limited
    Inventors: Tomomi Matsui, Kimiaki Yasuda, Michiyo Nojiri, Masanao Ohno
  • Patent number: 5244734
    Abstract: A process for producing fine cellulose particles, which comprises(1) mixing viscose with a water-soluble anionic polymeric compound or polyethylene glycol or its derivative to form a dispersion of fine particles of viscose,(2) (i) heating the dispersion or mixing it with a coagulating agent to thereby coagulate the viscose in the dispersion, and thereafter neutralizing it with an acid to form fine particles of cellulose, or (ii) coagulating and neutralizing the dispersion with an acid to form fine particles of cellulose, and(3) thereafter, separating the fine particles of cellulose from the mother liquor. The fine cellulose particles(a) are composed substantially of II-type cellulose,(b) have a crystallinity, of 5 to 35% by weight,(c) are composed substantially of particles of not more than 20 micrometers, and(d) have a sharp particle size distribution.
    Type: Grant
    Filed: January 15, 1988
    Date of Patent: September 14, 1993
    Assignees: Kanebo Ltd., Kanebo Rayon, Ltd.
    Inventors: Shigeru Okuma, Kanji Yamagishi, Masami Hara, Keizo Suzuki, Toshihiro Yamamoto
  • Patent number: 5245024
    Abstract: This invention relates to an improved cellulose chromatography support and, in particular, to substantially spherical, high density cellulose particles. This invention also relates to a method of making these spherical, high density cellulose particles and, in particular, to a method for forming spherical cellulose from a high molecular weight viscose in a stable emulsion of a liquid carrier and emulsifying agents.
    Type: Grant
    Filed: December 30, 1991
    Date of Patent: September 14, 1993
    Assignee: Loyola University of Chicago
    Inventors: Ioannis Scarpa, Anita Beavins
  • Patent number: 5236726
    Abstract: A method of processing cellulose sausage skins is disclosed in which sausage skins are filled with contents to make sausages, the cellulose sausage skins are removed from the sausages, the removed sausage skins are dissolved to form a recycled cellulose dope, and new sausage skins are formed from the recycled cellulose dope. Dissolving sausage skins under soda cellulose Q condition for subsequent reuse is specifically described. In addition, forming a dissolved cellulose feed stock for use in producing sausage skins employing cavitation and a solvent is disclosed.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: August 17, 1993
    Assignee: Weyerhaeuser Company
    Inventor: E. Peter Lancaster
  • Patent number: 5216144
    Abstract: Shaped cellulosic bodies and especially cellulosic fibers or filaments are produced by precipitating cellulose from a solution containing cellulose and NMMO. To allow elevated concentrations of NMMO in the precipitating bath without detriment to the properties of the fibers or filaments produced, the temperature of the precipitating bath is held at most at 0.degree. C.
    Type: Grant
    Filed: December 6, 1991
    Date of Patent: June 1, 1993
    Assignee: Lenzing Aktiengesellschaft
    Inventors: Dieter Eichinger, Raimund Jurkovic, Stephan Astegger, Heinrich Firgo, Peter Hinterholzer, Karin Weinzierl, Stefan Zikeli
  • Patent number: 5196527
    Abstract: This invention relates to ion-exchanged fine cellulose particles, porous fine cellulose particles which can be advantageously used as an affinity carrier, and methods of production thereof. These fine particles of the invention have the advantage that they possess excellent pressure-resistant strength and can treat treatment liquors under pressure at a high flowing velocity. Thus, they can be advantageously used industrially in various separation and purification processes.
    Type: Grant
    Filed: February 4, 1992
    Date of Patent: March 23, 1993
    Assignee: Kanebo Ltd.
    Inventors: Shigeru Ookuma, Kouei Igarashi, Masami Hara, Kazuhiro Aso, Hideo Yoshidome, Hiroshi Nakayama, Keizo Suzuki, Kazuhiko Nakajima
  • Patent number: 5189152
    Abstract: A solution of cellulose in water and N-methylmorpholine-N-oxide (NMMO) containing 2 to 44% by weight cellulose is stabilized at 0.01 to 1%, preferably 0.1% H.sub.2 O.sub.2 and 0.01 to 2%, preferably 0.1% of an H.sub.2 O.sub.2 stabilizer, preferably oxalic acid or a salt thereof during formation of the solution and during heating to prevent discoloration of the cellulose and reduce the composition of NMMO.
    Type: Grant
    Filed: July 16, 1991
    Date of Patent: February 23, 1993
    Assignee: Lenzing Aktiengesellschaft
    Inventors: Peter Hinterholzer, Stefan Zikeli, Heinrich Firgo, Bernd Wolschner, Dieter Eichinger, Johann Manner, Stephan Astegger, Karin Weinzierl
  • Patent number: 5187200
    Abstract: A process for selectively removing anions from an aqueous solution involves contacting the solution for an effective period of time with a specialized polymer in a porous format. The polymer has ligand sites capable of forming coordination or complexation bonds with multi-valent metal cations which serve to activate the polymer with respect to chemical interaction with anions. The polymer, saturated with the multivalent metal cations, contains between 2% and 20% of metal cation based upon the dry weight of the polymer.
    Type: Grant
    Filed: December 18, 1991
    Date of Patent: February 16, 1993
    Inventor: Norman B. Rainer
  • Patent number: 5152793
    Abstract: A biocompatible hydrophilic material is based on purified cellulose, from which material all or the majority of the water has been removed and which has a modulable potential for water recovery of up to an amount of water of approximately 60%. The material can be used for the production of fitting sheaths for articulated prostheses.
    Type: Grant
    Filed: January 9, 1992
    Date of Patent: October 6, 1992
    Assignee: La Cellulose Du Pin and Universite De Bordeaux II
    Inventors: Jean-Claude Pommier, Joel Poustis, Charles Baquey, Dominique Chauveaux
  • Patent number: 5108596
    Abstract: This invention relates to ion-exchanged fine cellulose particles, porous fine cellulose particles which can be advantageously used as an affinity carrier, and methods of production thereof. These fine particles of the invention have the advantage that they possess excellent pressure-resistant strength and can treat treatment liquors under pressure at a high flowing velocity. Thus, they can be advantageously used industrially in various separation and purification processes.
    Type: Grant
    Filed: December 4, 1989
    Date of Patent: April 28, 1992
    Assignee: Kanebo Ltd.
    Inventors: Shigeru Ookuma, Kouei Igarashi, Masami Hara, Kazuhiro Aso, Hideo Yoshidome, Hiroshi Nakayama, Keizo Suzuki, Kazuhiko Nakajima
  • Patent number: 5096946
    Abstract: A water-swellable polymer product which may be physically bound to an open celled cellulosic sponge is produced by thermally induced amide-forming insolubilization of polyethyleneimine (PEI). The polymer product has high affinity for the absorption of transition metal ions. A cellulosic sponge containing a high add-on of the polymer product is permeable to water and substantially unaffected by water-borne suspended matter.
    Type: Grant
    Filed: July 31, 1990
    Date of Patent: March 17, 1992
    Inventor: Norman B. Rainer
  • Patent number: 5064950
    Abstract: Fine crosslinked cellulose particles, wherein (1) said cellulose particles are composed substantially of a II-type cellulose crystalline phase and a non-crystalline cellulose phase, (2) said cellulose particles have a crystallinity, determined by X-ray diffractometry, of 5 to 35%, (3) said cellulose particles consist substantially of spherical to elongated spherical particles having an average particle diameter of not more than 300 .mu.m, and (4) said cellulose particles having an exclusion limit molecular weight by polyethylene glycol of not more than 4,000. The particles may have crosslinkage among the cellulose molecular chains in the non-crystalline phase.
    Type: Grant
    Filed: May 25, 1990
    Date of Patent: November 12, 1991
    Assignees: Kanebo, Ltd., Kanebo Rayon, Ltd.
    Inventors: Shigeru Okuma, Kanji Yamagishi, Masami Hara, Keizo Suzuki, Toshihiro Yamamoto, Hideo Yoshidome
  • Patent number: 4997488
    Abstract: A synergistic combination of high-shear mechanical disruption and alkali pretreatment in a high solids reaction mixture constitutes a significant improvement in the alkaline peroxide treatment of lignocellulosic materials. The simultaneous application of these conditions greatly reduces the amounts of reagents otherwise required, and also eliminates the waste stream of liquid byproducts. Suitable sources of substrate treatable by this process include nonwoody plant parts, crop residues, and agricultural byproducts. The products of this treatment are nontoxic and characterized by high cellulose availability. These products are thereby useful as carbohydrate sources in ruminant feeds, as microbial feedstocks, and as sources of dietary fiber for humans and other monogastrics.
    Type: Grant
    Filed: November 14, 1989
    Date of Patent: March 5, 1991
    Assignee: The United States of America as represented by the Secretary of Agriculture
    Inventors: John M. Gould, Brian K. Jasberg
  • Patent number: 4994285
    Abstract: An edible body composed of a cellulose having a crystal form of cellulose II, which is regenerated from an aqueous solution of an alkali metal hydroxide, and at least one guest component selected from polypeptides and edible polysaccharides. The cellulose II or a homogeneous mixture of the cellulose II and polysaccharide is present in the form of a sea component or a continuous phase in an amount of at least 10% based on the edible body.
    Type: Grant
    Filed: August 8, 1988
    Date of Patent: February 19, 1991
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Jinpei Hisano, Akihiro Goto, Kunihiko Okajima
  • Patent number: 4963664
    Abstract: New amines and amides of carboxylated polysaccharides having the nitrogen of the amido and amino groups directly attached to the polysaccharides and method of making same, based on reacting in solution a material having carboxyl-containing polysaccharides, such as carboxymethyl cellulose, with ammonium donors having the general formula >NH such as primary and secondary amine reagents and with or without a reducing agent to obtain amides or amines. These products may be used for instance in biological separations, for the immobilization of proteins, for the removal of metal ions, as thickeners, and as suspension agents.
    Type: Grant
    Filed: October 26, 1989
    Date of Patent: October 16, 1990
    Assignee: Domtar Inc.
    Inventors: Manssur Yalpani, Magdy M. Abdel-Malik
  • Patent number: 4946953
    Abstract: Fine crosslinked cellulose particles, wherein (1) said cellulose particles are composed substantially of a II-type cellulose crystalline phase and a non-crystalline cellulose phase, (2) said cellulose particles have a crystallinity, determined by X-ray diffractometry, of 5 to 35%, (3) said cellulose particles consist substantially of spherical to elongated spherical particles having an average particle diameter of not more than 300 .mu.m, and (4) said cellulose particles having an exclusion limit molecular weight by polyethylene glycol of not more than 4,000. The particles may have crosslinkage among the cellulose molecular chains in the non-crystalline phase.
    Type: Grant
    Filed: October 13, 1987
    Date of Patent: August 7, 1990
    Assignees: Kanebo, Ltd., Kanebo Rayon, Ltd.
    Inventors: Shigeru Okuma, Kanji Yamagishi, Masami Hara, Keizo Suzuki, Toshihiro Yamamoto, Hideo Yoshidome
  • Patent number: 4902792
    Abstract: A process for producing fine cellulose particles, which comprises(1) mixing viscose with a water-soluble anionic polymeric compound or polyethylene glycol or its derivative to form a dispersion of fine particles of viscose,(2) (i) heating the dispersion or mixing it with a coagulating agent to thereby coagulate the viscose in the dispersion, and thereafter neutralizing it with an acid to form fine particles of cellulose, or (ii) coagulating and neutralizing the dispersion with an acid to form fine particles of cellulose, and(3) thereafter, separating the fine particles of cellulose from the motor liquor. The fine cellulose particles(a) are composed substantially of II-type cellulose,(b) have a crystallinity, of 5 to 35% by weight,(c) are composed substantially of particles of not more than 20 micrometers, and(d) have a sharp particle size distribution.
    Type: Grant
    Filed: December 30, 1987
    Date of Patent: February 20, 1990
    Assignees: Kanebo Ltd., Kanebo Rayon, Ltd.
    Inventors: Shigeru Okuma, Kanji Yamagishi, Masami Hara, Keizo Suzuki, Toshihiro Yamamoto
  • Patent number: 4814440
    Abstract: The invention relates to a process for obtaining extractive-material-reduced cellulose with a low LAL reaction, wherein cotton linters or wood pulps, subsequent to the customary digesting treatment, are subjected for 1 to 10 hours to hydraulic washing with water, lye with a concentration of less than 5 g/l alkali content, or with a diluted acid containing less than 5 g/l acid at temperatures of 120.degree. to 180.degree. C. and under a pressure of 2 to 20 bar.The resulting cellulose is used for the manufacture of hemodialysis and/or hemofiltration membranes in the form of flat membranes, tubular membranes or hollow filaments by regeneration of a cellulose solution containing the extractive-material-reduced cellulose with a low LAL reaction.The regeneration may be effected from solutions of cellulose cuoxam, cellulose xanthate, or solutions of cellulose in tertiary amine oxide or in an LiCl-containing solvent.
    Type: Grant
    Filed: October 1, 1987
    Date of Patent: March 21, 1989
    Assignee: Akzo NV
    Inventors: Joachim Behnke, Helmut Schulze, Ernst Berg, Michael Pelger
  • Patent number: 4804695
    Abstract: Methods for producing spray cellulosic insulation and for wet spray open cavity installation of such material. Processed cellulosic fibers are moistened with an expansion agent, preferably comprising water with a wetting agent mixed therein. For installation, a composition preferably comprising an adhesive and a wetting agent in water is used to moisten the material as it is blown into place.
    Type: Grant
    Filed: September 3, 1987
    Date of Patent: February 14, 1989
    Assignee: Western Fibers, Inc.
    Inventor: Paul H. Horton
  • Patent number: 4784186
    Abstract: An improved non-reinforced cellulose film is disclosed. The film is useful as a sausage casing. When exposed to water the casing shrinks in the transverse or circumferential direction, so that the sausages look plump and crease-free and the casing can be peeled easily from the enclosed sausage meat. The film is made by moistening a non-reinforced cellulose film, drawing the film in the transverse direction, and drying the film in the stretched state.
    Type: Grant
    Filed: September 15, 1987
    Date of Patent: November 15, 1988
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Karl Stenger, Horst Faust
  • Patent number: 4708951
    Abstract: Anticoagulative high-molecular composition which comprises a cellulosic polyelectrolyte complex formed from a polycationic cellulose derivative such as a quaternary ammonium salt of hydroxyalkyl cellulose, and a polyanionic cellulose such as sodium cellulose glycolate, which is used in the field of medical instruments or devices.
    Type: Grant
    Filed: March 25, 1985
    Date of Patent: November 24, 1987
    Assignee: Daicel Chemical Industries Ltd.
    Inventors: Hiroshi Inagaki, Takeaki Miyamoto, Hiraku Ito, Tohru Shibata
  • Patent number: 4681935
    Abstract: The invention concerns a procedure for recovery of soluble carbohydrates present in wood, in connection with the alkaline cellulose digesting process. According to the invention, recovery of carbohydrates takes place at the initial phase of the cellulose digesting process, where the digesting solution contains dissolved polysaccharides in abundance, while the content of polymeric lignin in the solution is low. A situation like this exists at the stage when the digesting solution has not yet reached the temperature at which the digestion process mainly takes place. As taught by the invention, the carbohydrates are recovered by conducting digesting solution to an ultrafilter, which separates the carbohydrates therefrom, and by returning the filtered solution to the cellulose digestion. The carbohydrates that are obtained may be used e.g. in the manufacturing of sugar alcohols, or as raw materials for biotechnical processes.
    Type: Grant
    Filed: November 27, 1985
    Date of Patent: July 21, 1987
    Assignee: Enso-Gutzeit Oy
    Inventors: Kaj Forss, Matti Sten, Juhani Peltonen, Veikko Jokela
  • Patent number: 4610962
    Abstract: A carrier for immobilization of physiologically active substances is prepared by treating an assembly of regenerated cellulose fibers having a single fiber fineness of from 0.5 to 30 deniers and a length of at least 1 millimeter with a solution of a polymer having an acid anhydride group. This carrier is easy to handle and permits immobilization of a large amount of a physiologically active substance. Thus it can be used as a catalyst for chemical reactions, a specific absorbent for separation and purification, a material for clinical examination, or a medical material.
    Type: Grant
    Filed: June 1, 1984
    Date of Patent: September 9, 1986
    Assignee: Unitika Ltd.
    Inventors: Kunihiko Takagi, Masatsugu Mochizuki, Izumi Sakamoto, Hiroichi Teranishi
  • Patent number: 4556708
    Abstract: Disclosed is a smoke-permeable, nonreinforced film comprising regenerated cellulose, for manufacturing tubular sausage casings which have a seam extending in the direction of their longitudinal axis. The film has a wet tear strength of from about 18 to 30 N/mm.sup.2, both in the longitudinal and transverse directions, a degree of orientation in the range from about 1 to 1.2, and a number of alternate bends ranging from about 5,000 to 8,000 in the longitudinal direction, and from about 9,000 to 16,000, in the transverse direction.Also disclosed is a process for producing the film in which viscose is extruded in the form of a web, thereafter precipitated by treating it with a heated casting solution and then regenerated into cellulose hydrate gel. The casting solution used to precipitate the viscose comprises, per liter of solution, at least about 160 g of sulfuric acid and at least about 300 g of sodium sulfate and the molar ratio sulfuric acid/sodium sulfate is in the range from about 0.7 to 0.9.
    Type: Grant
    Filed: May 21, 1984
    Date of Patent: December 3, 1985
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Klaus Andrae, Max Bytzek, Elfried Hutschenreuter, Hans U. Lang
  • Patent number: 4536217
    Abstract: The invention pertains to the absorbing dressing for wounds, which consists of spherical particles of regenerated cellulose of the size 0.05-0.5 mm (preferably 0.05-0.3 mm) and a macroporous structure characterized by the cyclohexane regain of the dry material at least 0.2 ml/g. The dressing is prepared from the regenerated cellulose swollen with water by replacement with organic solvents and the subsequent drying of the product swollen with the said solvent. The porous structure of the dressing warrants that it can absorb excretions of the wound in the amount 1.5 to 5 g water per g of solids; the grainy macrostructure remains preserved during the absorption so that the material applied on the wound in the form of a powder in the layer 2-5 mm thick, in particular 2-3 mm thick, can be without difficulties and almost without pain rinsed away with water.
    Type: Grant
    Filed: September 28, 1983
    Date of Patent: August 20, 1985
    Assignees: Ceskoslovenska akademie ved of Praha, Akademie der Wissenschaften der DDR
    Inventors: Fritz Loth, Horst Dautzenberg, Jiri Stamberg, Jan Peska, Dieter Bertram, Herbert Lettau
  • Patent number: 4501886
    Abstract: High strength, high modulus cellulose triacetate fibers are produced by spinning a 30-42% by weight solution of cellulose triacetate having an acetyl content of at least 42.5% and an inherent viscosity of at least 5 from a solvent mixture comprising trifluoroacetic acid and another solvent having a molecular weight of less than 160 in a mol ratio of 0.3-3.0 through an air gap into a coagulating bath. The fibers are optionally heat treated under tension or saponified to provide high strength high modulus regenerated cellulose fibers.
    Type: Grant
    Filed: August 1, 1983
    Date of Patent: February 26, 1985
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: John P. O'Brien
  • Patent number: 4496456
    Abstract: A method is described for the production of regenerated cellulose membranes which method comprises the steps of:(a) dissolving a cellulose material to form a solution;(b) casting the cellulose solution into a film;(c) coagulating the cellulose solution film using an alkali alcoholic solution;(d) washing the coagulated cellulose film in an alcohol;(e) regenerating the cellulose film using acidic alcohol solution;(f) washing the regenerated cellulose membrane using an alcohol.The regenerated cellulose thus formed may be dried, if desired, preferably without a softener.The regenerated cellulose thus produced, when prepared in the form of a film or membrane, possesses higher flux and superior selectivity for organic liquid separation than regenerated cellulose membranes prepared employing aqueous solutions in steps b through e above and is most advantageously employed for the recovery of polar dewaxing solvents (e.g. ketones and mixed ketone/aromatic solvents) from dewaxed oil.
    Type: Grant
    Filed: June 3, 1983
    Date of Patent: January 29, 1985
    Assignee: Exxon Research & Engineering Co.
    Inventors: Mahmoud M. Hafez, Henry W. Pauls
  • Patent number: 4416698
    Abstract: A solution containing cellulose dissolved in a tertiary amine N-oxide solvent containing a nonsolvent for cellulose such as water is shaped by extrusion or other shaping process to form a shaped cellulose fiber, rod, plate, tubing or film. The extruded shaped article is stretched in air while still a solution to impart improved physical properties thereto and the cellulose is precipitated from the shaped solution to set the properties without additional drawing. The solution may be prepared by dissolving cellulose in the tertiary amine N-oxide solvent in the barrel of an extrusion apparatus, extending the solution, orienting by stretching the resulting product in air while still a solution and then precipitating the cellulose from the shaped article before significant degradation of the cellulose. The cellulose and tertiary amine N-oxide may be ground to substantially the same particle size before charging the extruder barrel.
    Type: Grant
    Filed: April 3, 1980
    Date of Patent: November 22, 1983
    Assignee: Akzona Incorporated
    Inventor: Clarence C. McCorsley, III
  • Patent number: 4409384
    Abstract: A process for the production of an acceptably filterable viscose from cellulose whereby cellulose is treated with an aqueous solution containing 13 to 16 weight percent NaOH, peroxide aged, xanthated and dissolved in dilute aqueous NaOH.
    Type: Grant
    Filed: November 12, 1981
    Date of Patent: October 11, 1983
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: William B. Lindsey
  • Patent number: 4384113
    Abstract: Improved basic polysaccharides are prepared by contacting a polysaccharide with a tetravalent onium salt such as tetramethylammonium chloride prior to contacting it with a strong base such as sodium hydroxide. Polysaccharide derivatives having a greater degree and uniformity of substitution are prepared from such improved basic polysaccharides.
    Type: Grant
    Filed: March 23, 1982
    Date of Patent: May 17, 1983
    Assignee: The Dow Chemical Company
    Inventor: William H. Daly
  • Patent number: 4381370
    Abstract: A method for producing fire-retarded blend fibers having a fire resistance LOl-value of at least 21% O.sub.2, made from cellulose and chlorine containing polymer. Chlorine containing polymer having a chlorine content of 30-75% by weight, is blended, either as such or dissolved in a solvent, with a DMSO/formaldehyde solution of cellulose so that the obtained blend has 10-70% by weight of chlorine containing polymers, based on the total amount of cellulose and said polymers. Fibers are produced of the obtained mixture by bringing it into contact with an aqueous or alcoholic solution.
    Type: Grant
    Filed: March 20, 1981
    Date of Patent: April 26, 1983
    Assignee: The Technical Research Centre of Finland
    Inventors: Olli Aaltonen, Martti Alkio, Eero Avela, Riitta-Maija Housh
  • Patent number: 4368323
    Abstract: The absorbent material is treated to increase its wettability in a substantive manner. This is accomplished by reacting a diepoxide compound with an absorbent material selected to have accessible hydroxyl groups and with a surfactant having functional end groups selected from the group consisting of primary amine or hydroxyl groups.
    Type: Grant
    Filed: September 21, 1981
    Date of Patent: January 11, 1983
    Assignee: Personal Products Company
    Inventor: Richard P. James
  • Patent number: 4363895
    Abstract: The present invention relates to new polymer solutions which make it possible to produce shaped articles, such as yarns and fibres, films, sheets and the like.These solutions consist of cellulose having a degree of polymerisation of at least 200, polyamide-imide, dimethyl sulphoxide and formaldehyde, with a weight ratio cellulose/polyamide-imide of 0.05 to 1, preferably 0.1 to 1, a ratio formaldehyde/cellulose of 0.2 to 2 and a total concentration of 6 to 25%, preferably 15 to 20%.These solutions are particularly suitable for the production of filaments which consist of fibrils substantially orientated along the axis of the fibre and closely intersecting, the cellulose macromolecules being partially involved in a crystal lattice characteristic of cellulose II. The filaments possess valuable properties for use in textiles.
    Type: Grant
    Filed: March 16, 1981
    Date of Patent: December 14, 1982
    Assignee: Rhone-Poulenc-Textile
    Inventors: Pierre Chion, Jacques Menault, Henry Rodier
  • Patent number: 4357468
    Abstract: The invention relates to new sorbents of cellulose basis capable of forming inclusion complexes, as well as to a process for the preparation thereof. The new sorbents according to the invention are cellulose derivatives containing structural units of the general formula (I), ##STR1## wherein Cell is a group derived by removing m hydroxy groups from the glucose unit of the cellulose chain,m is an integer of 1 to 3,CD is a group derived by removing one hydroxy group from the .alpha., .beta. or .gamma.-cyclodextrin molecule,n is an integer of 1 to 5, andp stands for 0 or 1, which may optionally vary even within a single chain.The cellulose derivatives according to the invention are substances of loose structure, with large specific surface area and good swelling properties, which can be applied for solving the most diverse adsorption tasks. Thus e.g.
    Type: Grant
    Filed: July 31, 1981
    Date of Patent: November 2, 1982
    Assignee: Chinoin Gyogyszer es Vegyeszeti Termekek Gyara Rt.
    Inventors: Jozsef Szejtli, Bela Zsadon, Eva Fenyvesi, nee Otta Horvath, Ferenc Tudos
  • Patent number: 4357467
    Abstract: Depolymerized cellulose powder having substantially an amorphous structure which is obtained by letting cellulose fibers dissolve in concentrated hydrochloric acid of about 40% and at a temperature of at least 38.degree. C. A homogeneous acid hydrolysis is carried out under well controlled conditions in order to depolymerize the dissolved cellulose and is stopped when the cellulose has achieved a mean degree of polymerization between 10 and 200. The depolymerized dissolved cellulose is then separated and processed in order to obtain the aforesaid powder of amorphous depolymerized cellulose.
    Type: Grant
    Filed: June 20, 1980
    Date of Patent: November 2, 1982
    Assignee: Battelle Memorial Institute
    Inventors: Jean-Pierre Sachetto, Jean-Pierre Michel, Sergio Cuccolo, Alain Regnault
  • Patent number: 4337095
    Abstract: A process for the preparation of high concentration solutions of cellulose erivatives in organic solvents comprises contacting with paraformaldehyde and the solvent a cellulose which has a polymerization degree lower than 300 and preferably not significantly higher than 200. The solvent is selected from among dimethylformamide, dimethylacetamide and N-methylpyrrolidone.
    Type: Grant
    Filed: May 30, 1980
    Date of Patent: June 29, 1982
    Assignee: SNIA Viscosa S.p.A. - Societa' Nazionale Industria Applicazioni Viscosa
    Inventors: Roberto Leoni, Alberto Baldini, Angelo Calloni, Gianfranco Angelini
  • Patent number: 4319023
    Abstract: A process for producing regenerated cellulosic articles from cellulose which has been dissolved in a mixture of dimethyl sulfoxide (DMSO) and formaldehyde, and for recovering the solvent chemicals. The DMSO/formaldehyde solution of cellulose is brought into contact with an aqueous solution, the pH of which is at least 9 and the adjustment of pH has been carried out by means of a base or an alkaline salt which does not react with formaldehyde and the content of which is at most 0.1% by weight, so that the product is coagulated and regenerated in the desired form, such as fibres, films or shaped articles. The coagulation solution is evaporated in one stage or plurality of stages so that the DMSO and formaldehyde of the cellulose solution remain in the evaporation residue. The evaporation residue is recycled for the production of cellulose solution, purified, if so required.
    Type: Grant
    Filed: March 18, 1981
    Date of Patent: March 9, 1982
    Assignee: Technical Research Centre of Finland
    Inventors: Olli Aaltonen, Martti Alkio
  • Patent number: 4268666
    Abstract: A process for the dissolution of cellulose in organic solvents such as dihylformamide, dimethylacetamide, and N-methylpyrrolidone is described which comprises contacting the cellulose with an excess of paraformaldehyde and with the solvent at elevated temperatures, preferably higher than 115.degree. C. The amount of paraformaldehyde used preferably corresponds to at least 13 CH.sub.2 O units per anhydroglucosidic unit of the cellulose. The solution obtained can be rendered stable at room temperature by heating it under stirring to lower the paraformaldehyde content, preferably to not less than 8 CH.sub.2 O units per anhydroglucosidic unit. Formed bodies of regenerated cellulose can be obtained from said solutions by coagulating them in an aqueous bath, which may be alkaline or may be a mixture of water and the solvent of the solution, or even by evaporating the solvent.
    Type: Grant
    Filed: March 29, 1979
    Date of Patent: May 19, 1981
    Assignee: SNIA VISCOSA Societa Nazionale Industria Applicazioni Viscosa S.p.A.
    Inventors: Alberto Baldini, Roberto Leoni, Angelo Calloni, Gianfranco Angelini
  • Patent number: 4256613
    Abstract: A composition and process are provided for making precipitated biconstituent nylon-cellulose shaped articles by dissolving a nylon having an amide group index of less than about 145, in a mixture of a tertiary amine oxide solvent and water, containing from about 0.5% to about 11% water based on the weight of the solution; separately forming a solution of cellulose in a tertiary amine oxide solvent containing from about 0.8 to about 29% water based on the weight of the solution and then interdispersing the two solutions to form a biconstituent dispersion. Shaped articles can be formed from the biconstituent dispersions of the invention.
    Type: Grant
    Filed: July 2, 1979
    Date of Patent: March 17, 1981
    Assignee: Akzona Incorporated
    Inventors: Neal E. Franks, Julianna K. Varga
  • Patent number: 4255300
    Abstract: A composition and process are provided for making precipitated biconstituent cellulose-polyvinyl alcohol shaped articles by dissolving polyvinyl alcohol and cellulose in a tertiary amine oxide solvent containing from about 0.8 to about 29% water to form a biconstituent dispersion wherein the cellulose and polyvinyl alcohol comprise distinct phases, preferably with the two solutions codispersed within each other. Shaped articles can be formed from the biconstituent dispersions of the invention.
    Type: Grant
    Filed: July 2, 1979
    Date of Patent: March 10, 1981
    Assignee: Akzona Incorporated
    Inventors: Neal E. Franks, Julianna K. Varga
  • Patent number: 4246221
    Abstract: A solution containing cellulose dissolved in a tertiary amine N-oxide solvent containing a nonsolvent for cellulose such as water is shaped by extrusion or other shaping process to form a shaped cellulose fiber, rod, plate, tubing or film. The extruded shaped article is stretched in air while still a solution to impart improved physical properties thereto and the cellulose is precipitated from the shaped solution to set the properties without additional drawing. The solution may be prepared by dissolving cellulose in the tertiary amine N-oxide solvent in the barrel of an extrusion apparatus, extruding the solution, orienting by stretching the resulting product in air while still a solution and then precipitating the cellulose from the shaped article before significant degradation of the cellulose. The cellulose and tertiary amine N-oxide may be ground to substantially the same particle size before charging the extruder barrel.
    Type: Grant
    Filed: March 2, 1979
    Date of Patent: January 20, 1981
    Assignee: Akzona Incorporated
    Inventor: Clarence C. McCorsley, III
  • Patent number: 4237274
    Abstract: A process for the preparation of solutions of cellulose derivatives from which formed bodies, such as fibres or films, of regenerated cellulose can be obtained by coagulation and regeneration, e.g. by wet spinning, is disclosed. The cellulose is transformed into a methylol derivative containing more than 2 units of formaldehyde per anydroglucosidic unit, which derivative is soluble in organic solvents of the class consisting of polar aprotic solvents constituted by N-substituted amides, pyridine and formamide. The methylol derivative is prepared by treating cellulose with paraformaldehyde and dimethylsulphoxide. The methylol derivative is then dissolved in one of the aforesaid solvents, preferably dimethylformamide or dimethylacetamide, to provide spinnable viscous solutions from which formed bodies can be obtained, e.g. by spinning in an aqueous alkaline bath.
    Type: Grant
    Filed: February 23, 1979
    Date of Patent: December 2, 1980
    Assignee: SNIA VISCOSA Societa' Nazionale Industria Applicazioni Viscosa S.p.A.
    Inventors: Roberto Leoni, Alberto Baldini, Gianfranco Angelini
  • Patent number: 4215212
    Abstract: Regenerated cellulose products containing formaldehyde cross linked sodium lignate or sodium lignosulfonate in an amount of from about 1% to about 40% by weight based on the weight of the cellulose in the product are prepared by mixing one of the cross linked lignin derivatives or a mixture thereof substantially uniformly in a viscose solution and extending the solution into a spin bath in which the extruded viscose streams coagulate into filaments containing the cross linked lignin derivative. The extended regenerated product may be used as a fiber in absorbent cellulose products such as diapers, sanitary napkins, tampons and the like.
    Type: Grant
    Filed: April 9, 1979
    Date of Patent: July 29, 1980
    Assignee: Akzona Incorporated
    Inventor: Neal E. Franks