Patents by Inventor Lars-Henrik Nyman

Lars-Henrik Nyman 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: 7569736
    Abstract: The invention relates to a process for producing monopentaerythritol of high purity and monopentaerythritol produced by the process. Formaldehyde is reacted with acetaldehyde in an aqueous solution in the presence of a strongly basic hydroxide in a conventional way. The obtained reaction mixture is evaporated to a dryness of 50-70% by weight and is thereafter cooled. Crystals of pentaerythritol thereby formed are separated off. The crystals are dissolved in water or in a water-containing mother liquor containing pentaerythritol to a dryness of 35-55% by weight. The solution is treated in a purification step whereupon monopentaerythritol of high purity is crystallized at a temperature of 40-90° C. and separated from the remaining mother liquor which is recirculated to the above mentioned step.
    Type: Grant
    Filed: February 5, 2007
    Date of Patent: August 4, 2009
    Assignee: Perstorp Specialty Chemicals AB
    Inventors: Hans-Ake Bengtsson, Lars-Henrik Nyman
  • Publication number: 20090062575
    Abstract: The invention relates to a process for producing monopentaerythritol of high purity and monopentaerythritol produced by the process. Formaldehyde is reacted with acetaldehyde in an aqueous solution in the presence of a strongly basic hydroxide in a conventional way. The obtained reaction mixture is evaporated to a dryness of 50-70% by weight and is thereafter cooled. Crystals of pentaerythritol thereby formed are separated off. The crystals are dissolved in water or in a water-containing mother liquor containing pentaerythritol to a dryness of 35-55% by weight. The solution is treated in a purification step whereupon monopentaerythritol of high purity is crystallized at a temperature of 40-90° C. and separated from the remaining mother liquor which is recirculated to the above mentioned step.
    Type: Application
    Filed: February 5, 2007
    Publication date: March 5, 2009
    Applicant: PERSTORP SPECIALTY CHEMICALS AB
    Inventors: Hans-Ake Bengtsson, Lars-Henrik Nyman