Patents by Inventor Ralf A. Lange

Ralf A. Lange 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: 5306803
    Abstract: A process for cleaning thermoplasts is described. The thermoplast to be cleaned is introduced between the discs of a plast compactor and substantially freed from unwanted residues from the polymerization process by the force and rise in temperature produced by the movement of rotation.
    Type: Grant
    Filed: May 17, 1991
    Date of Patent: April 26, 1994
    Assignee: Bayer Aktiengesellschaft
    Inventors: Wolfgang Arlt, Manfred Schmidt, Thomas Fischer, Ralf Lange
  • Patent number: 4735721
    Abstract: The present invention is directed to a process for the preparation of a segmented, aliphatic-aromatic polyether-copolycarbonate containing structural units conforming to ##STR1## wherein --D-- is a diphenolate radical and units conforming to ##STR2## wherein --O--Polyether--O-- is an aliphatic polyether-diolate radical, by the phase boundary process in which aliphatic polyether diol and a mixture of dihydroxy compounds are reacted with a carbonic acid halide which is employed in molar excess in relation to the dihydroxy compounds and in which the aqueous phase is kept at a pH value of at least 13 and where the polycondensation reaction is carried out in a reactor by addition of an amine catalyst.The invention is further directed to the polyether polycarbonate which is obtained by the process and to the preparation of membranes from said polyether copolycarbonate.
    Type: Grant
    Filed: March 17, 1986
    Date of Patent: April 5, 1988
    Assignee: Bayer Aktiengesellschaft
    Inventors: Manfred Schreckenberg, Rolf Dhein, Ralf Lange, Werner Waldenrath
  • Patent number: 4607070
    Abstract: The present invention is directed to a process for the preparation of a segmented, aliphatic-aromatic polyether-copolycarbonate containing structural units conforming to ##STR1## wherein --D-- is a diphenolate radical and units conforming to ##STR2## wherein --O--Polyether--O-- is an aliphatic polyether-diolate radical, by the phase boundary process in which aliphatic polyether diol and a mixture of dihydroxy compounds are reacted with a carbonic acid halide which is employed in molar excess in relation to the dihydroxy compounds and in which the aqueous phase is kept at a pH value of at least 13 and where the polycondensation reaction is carried out in a reactor by addition of an amine catalyst.The invention is further directed to the polyether polycarbonate which is obtained by the process and to the preparation of membranes from said polyether copolycarbonate.
    Type: Grant
    Filed: September 26, 1984
    Date of Patent: August 19, 1986
    Assignee: Bayer Aktiengesellschaft
    Inventors: Manfred Schreckenberg, Rolf Dhein, Ralf Lange, Werner Waldenrath
  • Patent number: 4563516
    Abstract: The present invention relates to a process for the preparation of polyether-polycarbonates, a process for stabilizing the polyether-polycarbonates thus prepared, a process for the production of membranes from the polyether-polycarbonates prepared according to the invention, stabilized membranes obtainable by the process according to the invention and the use of the polyether-polycarbonate membranes obtainable by the process according to the invention for dialysis, ultrafiltration and reverse osmosis.
    Type: Grant
    Filed: August 15, 1984
    Date of Patent: January 7, 1986
    Assignee: Bayer Aktiengesellschaft
    Inventors: Manfred Schreckenberg, Rolf Dhein, Ralf Lange, Werner Waldenrath
  • Patent number: 4098754
    Abstract: The present invention is concerned with a process for the production of high molecular weight thermoplastic ppolycarbonates having improved flame resistance and in conjunction with glass fibres, improved mechanical properties and the polycarbonates so produced. A solution polycarbonate is reacted with an alkali metal salt soluble in the melt of the polycarbonate until the Staudinger Index has increased by about 3 to 30 cm.sup.3 /g. This usually requires about 0.0001 to 0.1 wt. % of the salt, based on the weight of polycarbonate and a temperature of about 250.degree. to 400.degree. C for between about 1 and 30 minutes. In a preferred embodiment the reaction is conducted in a self-cleaning twin screw extruder.
    Type: Grant
    Filed: December 11, 1975
    Date of Patent: July 4, 1978
    Assignee: Bayer Aktiengesellschaft
    Inventors: Dieter Neuray, Hugo Vernaleken, Claus Wulff, Ralf Lange
  • Patent number: 3979454
    Abstract: Improved process for the production of alkyl sulphonic acid hydroxy alkyl amides by reacting alkyl sulphonic acid chlorides and hydroxy alkyl amines in the presence of acid binding agents wherein aqueous alkali hydroxide solution is used as acid-binding agent, the three components are applied in a substantially stoichiometric ratio, and the reaction is carried out by adding the alkyl sulphonic acid chloride to the hydroxy alkyl amine and adding to the mixture thus obtained the aqueous alkali hydroxide solutions at such a rate that the pH-value of the reaction mixture does not exceed pH 10.
    Type: Grant
    Filed: March 17, 1975
    Date of Patent: September 7, 1976
    Assignee: Bayer Aktiengesellschaft
    Inventors: Hermann Perrey, Harry Welz, Ralf Lange, Hans Rudolph, Hans Jurgen Rosenkranz