Patents by Inventor Gerd Littmann

Gerd Littmann 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).

  • Distillative preparation of IPDA having a high cis/trans isomer ratio
    Patent number: 7497931
    Abstract: The invention relates to a process for recovering 3-aminomethyl-3,5,5-trim-ethylcyclohexylamine (isophoronediamine, IPDA) having a fractionally distilled cis/trans isomer ratio of at least 73/27. The process includes the following steps: a) providing IPDA in a cis/trans isomer ratio of <73/27; b) feeding IPDA into the middle region of a distillation column having internals and distilling the IPDA in this distillation column at a temperature of from 5 to 300.degree. C.
    Type: Grant
    Filed: August 8, 2003
    Date of Patent: March 3, 2009
    Assignee: BASF Aktiengesellschaft
    Inventors: Frank Funke, Thomas Hill, Jobst Rüdiger Von Watzdorf, Wolfgang Mattmann, Wolfgang Harder, Erhard Henkes, Gerd Littmann, Manfred Julius
  • Method for the production of isophorondiamine (ipda, 3-aminomethyl-3,5,5-trimethyl- cyclohexylamine) having a high cis/tran-isomer ratio
    Patent number: 7256313
    Abstract: The invention relates to processes for preparing 3-aminomethyl-3,5,5-trimethylcyclo-hexylamine (isophoronediamine, IPDA) having a high cis/trans isomer ratio. IPDA having a cis/trans isomer ratio in the range from 63/37 to 66/34 can be obtained in any desired cis/trans isomer ratio, irrespective of temperature, by reacting IPDA with H2 and NH3 in the presence of a hydrogenation catalyst. IPDA having a cis/trans isomer ratio of at least 73/27 which is an important starting material for the synthesis of polyurethanes and polyamides can be obtained by combining this isomerization process with distillative processes.
    Type: Grant
    Filed: August 6, 2003
    Date of Patent: August 14, 2007
    Assignee: BASF Aktiengesellschaft
    Inventors: Frank Funke, Thomas Hill, Jobst Rüdiger Von Watzdorf, Wolfgang Mattmann, Wolfgang Harder, Erhard Henkes, Gerd Littmann, Manfred Julius
  • Distillative preparation of ipda having a high cis-trans isomer ratio
    Publication number: 20050252761
    Abstract: The invention relates to a process for recovering 3-aminomethyl-3,5,5-trimethylcyclohexylamine(isophoronediamine, IPDA) having a cis/trans isomer ratio of at least 73/27 by fractional distillation, which comprises the following steps: a) providing IPDA in a cis/trans isomer ratio of <73/27; b) feeding IPDA into the middle region of a distillation column having internals and distilling the IPDA in this distillation column at a temperature of from 5 to 300° C.
    Type: Application
    Filed: August 8, 2003
    Publication date: November 17, 2005
    Applicant: Basf Aktiengesellschaft
    Inventors: Frank Funke, Thomas Hill, Jobst Watzdorf, Wolfgang Mattmann, Wolfgang Harder, Erhard Henkes, Gerd Littmann, Manfred Julius