Patents by Inventor Alwin Heller

Alwin Heller 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).

  • Process for the preparation of granular oxymethylene polymers having improved mechanical properties
    Patent number: 4195158
    Abstract: Oxymethylene polymers (POM) are obtained in a granular form, by cooling a POM solution or dispersion, whose temperature is above the sintering temperature of the POM, to a temperature slightly below the sintering temperature of the POM, and extracting from the suspension obtained only those POM particles which show a grain diameter of more than 70 .mu.m. As solvent or dispersing agent as well as precipitating and cooling agent there is used a mixture of methanol and water with a methanol content of at least 75% by weight. The POM obtained is suitable as engineering plastic material for the manufacture of shaped articles having improved mechanical properties.
    Type: Grant
    Filed: August 8, 1978
    Date of Patent: March 25, 1980
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Karlheinz Burg, Alwin Heller, Hans-Dieter Sabel, Helmut Schlaf, Gunter Sextro
  • Process for preparing oxymethylene polymers in a granular form
    Patent number: 4151346
    Abstract: Oxymethylene polymers are obtained in a granular form by cooling a solution or dispersion of an oxymethylene polymer, the temperature of which solution or dispersion is above the sintering temperature of the oxymethylene polymer, to a temperature just below the sintering temperature of the oxymethylene polymer. As dissolving or dispersing agent as well as precipitating and cooling agent there is used a mixture of methanol and water having a methanol content of at least 75% by weight. The oxymethylene polymer obtained is suitable as engineering plastic for preparing moulded articles.
    Type: Grant
    Filed: January 26, 1978
    Date of Patent: April 24, 1979
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Gunter Sextro, Karlheinz Burg, Helmut Schlaf, Hans J. Leugering, Alwin Heller
  • Process for the manufacture of coarse-granular oxymethylene polymers
    Patent number: 4111912
    Abstract: Granular oxymethylene polymers are prepared by cooling a solution or dispersion of an oxymethylene polymer, the temperature of the said solution or dispersion being above the sintering temperature of the oxymethylene polymer, to a temperature just below the said sintering temperature. As dissolving or dispersing agent there is used a mixture of methanol and water. The cooling of the said solution or dispersion is effected in two stages while using a liquid cooling agent or a cooling device. After precipitation the coarse-granular polymer is separated from the fine-granular portion. It is suitable as engineering plastic for preparing molded articles.
    Type: Grant
    Filed: May 4, 1977
    Date of Patent: September 5, 1978
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Gunter Sextro, Karlheinz Burg, Helmut Schlaf, Hans-Dieter Sabel, Alwin Heller
  • Process for the manufacture of granular oxymethylene polymers
    Patent number: 4046738
    Abstract: Oxymethylene polymers (POM) are obtained in granular form by cooling a POM solution or dispersion having a temperature above the sintering temperature of the POM in two stages to a temperature just below the said sintering temperature. The solvent or dispersion agent used is a mixture of methanol and water and the cooling agent is a methanol/water mixture which may contain POM suspended therein. The granular POM obtained is suitable as technical material for making shaped articles.
    Type: Grant
    Filed: November 5, 1975
    Date of Patent: September 6, 1977
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Gunter Sextro, Karlheinz Burg, Hans Joachim Leugering, Helmut Schlaf, Alwin Heller