Patents Assigned to Polyphalt Inc.
  • Patent number: 6737443
    Abstract: Methods for making the stable dispersion of lignin components of black liquor in bitumen. Representative methods comprising converting an aqueous colloidal dispersion of lignin in spent pulping liquor to an anhydrous colloidal dispersion of lignin in a lubricating oil by mixing a lubricating oil with the spent pulping liquor, and dewatering the mixture so formed at an elevated temperature to form a cream-like paste compatible with bitumen, and mixing said anhydrous colloidal dispersion of lignin with bitumen.
    Type: Grant
    Filed: November 20, 2000
    Date of Patent: May 18, 2004
    Assignee: Polyphalt Inc.
    Inventor: Zhi-Zhong Liang
  • Patent number: 6579921
    Abstract: Roofing membranes are provided with both high stiffness at high temperature (greater than 110 ° C.) and good flexibility at low temperature (less than −20 ° C.). Bituminous compositions may be more effectively used in such membranes at lower elastomer concentration than currently practiced, using conventional cross-linking reagents to prepare the modified bituminous compositions with a range of viscosities that are readily processed as compared with conventional non-cross-linked systems.
    Type: Grant
    Filed: September 24, 2001
    Date of Patent: June 17, 2003
    Assignee: Polyphalt Inc.
    Inventors: Zhi Zhong Liang, Yan-Ping Zhang
  • Patent number: 6174939
    Abstract: Normally incompatible styrenic polymers are stably incorporated into bitumen by using an elastomeric triblock copolymer comprising polystyrene segments which is solubilized or compatibilized in the bituminous phase. The elastomeric triblock copolymer incorporated into the continuous bituminous phase provides polystyrene domains which are dispersed throughout the bitumen or a receiving unit which stabilize the particulate polystyrene against separation from the bitumen.
    Type: Grant
    Filed: May 7, 1999
    Date of Patent: January 16, 2001
    Assignee: Polyphalt Inc.
    Inventor: Zhi-Zhong Liang