Patents by Inventor Axel Walch

Axel Walch 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: 5137928
    Abstract: The invention relates to ultrasonic contrast agents composed of microparticles which contain a gas and polyamino-dicarboxylic acid-co-imide derivatives, to processes for their preparation and to their use as diagnostic and therapeutic agents.
    Type: Grant
    Filed: April 24, 1991
    Date of Patent: August 11, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Raimund Erbel, Rainer Zotz, Volker Krone, Michael Magerstadt, Axel Walch
  • Patent number: 5106740
    Abstract: A cofactor having an aromatic or benzylic amino group is converted into an isothiocyanate by reaction with a compound such as thiophosgene and the isothiocyanate of the cofactor is attached to a polymer which is preferably water-soluble. When the polymer has amino groups, a thiourea bridge is formed between the polymer and cofactor and a polymer having hydroxyl groups results in a thiocarbamate bridge. The polymer may be a copolymer of vinylamine or vinylmethylamine and vinylmethylacetamide, partially alkylamine-substituted .alpha., .beta.-poly-(2-hydroxyethyl)-D,L-aspartamide, polyethyleneimine or carbohydrate. The cofactor bound to a polymer and an enzyme are contained in microcapsules or in a membrane to form an enzyme reactor.
    Type: Grant
    Filed: December 6, 1990
    Date of Patent: April 21, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hubert Bader, Hans-Ullrich Hoppe, Michael Magerstadt, Merten Schlingmann, Dieter Ulschneider, Axel Walch
  • Patent number: 5100673
    Abstract: Polyelectrolyte membrane capsules are composed of a semi-permeable membrane and an active material enclosed by it, the membrane being formed of a biocompatible, non-toxic polyacid and a polybase; the polybase is composed of repeating monomer units of the formula (I) ##STR1## in which R.sup.1 and R.sup.2 have the indicated meanings.
    Type: Grant
    Filed: February 21, 1990
    Date of Patent: March 31, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hebert Bader, Karl-Heinz Keil, Diether Ruppel, Merten Schlingmann, Axel Walch
  • Patent number: 5041291
    Abstract: The invention relates to biodegradable poly((hydroxyalkyl)amino dicarboxylic acid) derivatives of the formula I ##STR1## in which n, m, x, y, z, R and R' have the indicated meanings, and to a process for their preparation and to the use thereof for depot formulations with controlled delivery of active ingredient.
    Type: Grant
    Filed: September 5, 1989
    Date of Patent: August 20, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hubert Bader, Diether Ruppel, Axel Walch
  • Patent number: 5009824
    Abstract: A process for preparing an asymmetrical macroporous membrane from a polymer solution comprised as the dissolved portion fraction a polymeric mixture comprised of about 5-70% by weight of polyvinylpyrrolidone having a molecular weight of .gtoreq.100,000 Dalton and about 95-30% by weight of a polymer selected from the group consisting of polysulfone, a polyether sulfone, and an aromatic or araliphatic polyamide, said weight being relative to the total weight of the dissolved polymeric fraction, by action of a coagulating liquid, wherein the coagulation is effected under conditions such that skin formation, asymmetrical port formation and retention of the polyvinylpyrrolidone are achieved, recovering the asymmetrical macroporous membrane comprising the polymeric mixture.
    Type: Grant
    Filed: October 23, 1989
    Date of Patent: April 23, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Axel Walch, Juergen Wildhardt, Dieter Beissel
  • Patent number: 4906473
    Abstract: The invention relates to biodegradable poly((hydroxyalkyl)amino dicarboxylic acid) derivatives of the formula I ##STR1## in which n, m, x, y, z, R and R' have the indicated meanings, and to a process for their preparation and to the use thereof for depot formulations with controlled delivery of active ingredient.
    Type: Grant
    Filed: December 31, 1987
    Date of Patent: March 6, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hubert Bader, Diether Ruppel, Axel Walch
  • Patent number: 4835248
    Abstract: Polyamides in which amino acids are incorporated in the polymer backbone via two amino or carboxyl groups and which carry in the .alpha.-position to the amide structure a functional group which is responsible for degradation and active compound release are highly suitable for the preparation of biologically degradable active compound depot preparations having controlled release of the active compound.
    Type: Grant
    Filed: May 13, 1987
    Date of Patent: May 30, 1989
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hubert Bader, Diether Ruppel, Axel Walch, Michael Magerstadt
  • Patent number: 4720343
    Abstract: Disclosed are asymmetrical macroporous membranes based on a synthetic polymer comprising a polymeric mixture of 5 to 70% by weight polyvinylpyrrolidone having a molecular weight .gtoreq.100,000 Dalton and 95 to 30% by weight of a polymer selected from a group consisting of a polysulfone, a polyether sulfone and an aromatic or araliphatic polyamide, each of the percentages by weight being relative to the total weight of the polymeric mixture. The membrane has a water absorbency of at least 11% by weight of water, relative to its total weight, at 100% relative humidity and 25.degree. C. Also disclosed is a process for preparation of the membranes.
    Type: Grant
    Filed: December 10, 1982
    Date of Patent: January 19, 1988
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Axel Walch, Juergen Wildhardt, Dieter Beissel
  • Patent number: 4557955
    Abstract: The invention relates to films and tubular structures which are selectively permeable to liquids and gases which are based on a copolymer composed of a copolymerized fluorinated olefin, copolymerized vinyl acetate and, optionally, a copolymerized olefin. It is possible for the acetate groups of the copolymer to have been saponified to form OH groups. The films or tubular structures have in each case an inherent, latent capacity for modifying their structure and are at the same time oleophobic and oleophilic. The invention also embraces processes for the preparation of the shaped articles described and processes for modifying their structure. The invention also relates to the use of shaped articles according to the invention.
    Type: Grant
    Filed: July 27, 1982
    Date of Patent: December 10, 1985
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Axel Walch, Walter Seifried, Wolfgang Michel, Jurgen Kuhls, Jurgen Wildhardt
  • Patent number: 4524155
    Abstract: The present invention relates to molded articles of an open-cell structure, containing a copolymer which is comprised of copolymerized, fluorinated olefin, copolymerized vinyl acetate and optionally copolymerized olefin, the acetate groups of the copolymer being optionally saponified into OH groups. The molded articles possess an inherent latent structural convertibility and have effective pores of a diameter in the range from 0.002 to 10 .mu.m. The invention further includes processes for the preparation of the specified molded articles and processes for converting their structure. The invention also relates to several uses of molded articles according to the invention.
    Type: Grant
    Filed: September 13, 1984
    Date of Patent: June 18, 1985
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Axel Walch, Walter Seifried, Wolfgang Michel, Jurgen Kuhls, Juergen Wildhardt
  • Patent number: 4499211
    Abstract: The present invention relates to molded articles of an open-cell structure, containing a copolymer which is comprised of copolymerized, fluorinated olefin, copolymerized vinyl acetate and optionally copolymerized olefin, the acetate groups of the copolymer being optionally saponified into OH groups. The molded articles possess an inherent latent structural convertibility and have effective pores of a diameter in the range from 0.002 to 10 .mu.m. The invention further includes processes for the preparation of the specified molded articles and processes for converting their structure. The invention also relates to several uses of molded articles according to the invention.
    Type: Grant
    Filed: July 27, 1982
    Date of Patent: February 12, 1985
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Axel Walch, Walter Seifried, Wolfgang Michel, Jurgen Kuhls, Jurgen Wildhardt
  • Patent number: 4354938
    Abstract: Disclosed is a viscose membrane suitable for hemodialysis, comprising a viscose membrane substantially equally oriented in the longitudinal and in the transverse directions, having in the dry state a birefringence in each direction of not more than about 6.times.10.sup.-3 and a phase difference of not more than about 150 nm, and wherein during transition from a dry into a wet state, the membrane undergoes a shrinkage of between about 0.5 and 10 percent both in the longitudinal and in the transverse directions. The membrane is produced by a process which is characterized in that the membrane is transversely stretched by 40 to 120% prior to drying.
    Type: Grant
    Filed: August 10, 1978
    Date of Patent: October 19, 1982
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Axel Walch, Max Bytzek, Jurgen Wildhardt, Klaus-Dieter Hammer
  • Patent number: 4229291
    Abstract: Disclosed is a specific polyamide membrane suitable for hemofiltration, comprising a permselective asymmetric membrane of heteroporous structure comprising a polyamide which comprises a plurality of recurring terephthaloyldiamine units. The membrane has an ultrafiltration capacity of from about 1.5.SM.10.sup.-3 to about 15.multidot.10.sup.-3 cm/s.multidot.bar, determined for water at 0.1 bar and 20.degree. C., a thickness of not more than about 100 microns, and a molecular weight exclusion limit of from about 20,000 to about 70,000 Dalton. The membrane is produced in a process which comprises introducing a solution of the polyamide in a water-miscible organic solvent into an aqueous precipitating liquid to obtain a coagulated membrane sheet, which is subsequently washed and dried.
    Type: Grant
    Filed: November 20, 1978
    Date of Patent: October 21, 1980
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Axel Walch, Jurgen Wildhardt, Dieter Beissel
  • Patent number: 4206050
    Abstract: A membrane unit and apparatus for removing toxic metabolites and metabolites normally present in urine from blood is disclosed. The unit comprises an arrangement of at least one permselective membrane and a fluid-absorbing and/or fluid-draining carrier containing at least one adsorbent. The apparatus comprises at least one membrane unit which is connected to inlet and outlet means for transporting blood to and from the unit.
    Type: Grant
    Filed: September 1, 1977
    Date of Patent: June 3, 1980
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Axel Walch, Wolfgang Michel, Ludwig Lammers
  • Patent number: 4183811
    Abstract: A membrane unit and apparatus for removing toxic metabolites and metabolites normally present in urine from blood is disclosed. The unit comprises a cavity through which the contaminated blood passes, said cavity comprising at least one permselective membrane and at least one adsorbent. The apparatus comprises at least one membrane unit which is connected to inlet and outlet means for transporting contaminated blood to the unit and decontaminated blood from the unit.
    Type: Grant
    Filed: September 1, 1977
    Date of Patent: January 15, 1980
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Axel Walch, Ludwig Lammers
  • Patent number: 4075093
    Abstract: The process of separating citric acid and/or isocitric acid and their salts from aqueous solutions containing said acids or their salts, and especially from fermentation solutions, consists in contacting said solutions under pressure with a permselective membrane. The material composing said membrane has introduced thereinto acid or basic groups so as to yield membranes of predetermined swelling power. Preferred membranes are those consisting of polyimide or polyamide polycondensation products which are modified by acid or basic groups, of polysulfones modified by acid groups, or of vinyl polymers modified by acid or basic groups. Adjustment of the starting solutions to a pH lower than 3.0 is advantageously effected by means of polyvinylsulfonic acid.
    Type: Grant
    Filed: October 23, 1975
    Date of Patent: February 21, 1978
    Assignee: Joh. A. Benckiser GmbH
    Inventors: Axel Walch, Albrecht Klimmek, Klaus Wollmann