Patents by Inventor Walter Mahler

Walter Mahler 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: 5053155
    Abstract: A blend of from 10% to 100% 1,1,2,2-tetrafluoroethane with at least one of 1,1,1,2-tetrafluoroethane and pentafluoroethane as refrigerant mixed with a mono- or di-functional polyalkylene glycol based on at least 80% propylene oxide having an SUS viscosity at 100.degree. F. of 100 to 1200 is disclosed for use in compression refrigeration.
    Type: Grant
    Filed: December 19, 1989
    Date of Patent: October 1, 1991
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Walter Mahler
  • Patent number: 4908197
    Abstract: Methods are described for preparing aluminum nitride of controllable morphology for ceramic and heat conduction applications. The methods comprise forming spherical particles or flakes of an intermediate, RA1NH, followed by heating the spheres or flakes of RA1NH at elevated temperatures to produce high purity aluminum nitride of corresponding morphology. Spheres of RA1NH are formed by (i) freezing a suspension of RA1NH in a liquid medium and thawing, by (ii) aging the suspension, or by (iii) dissolving RA1NH in a liquid medium and precipitating it. Flakes are formed by freezing a suspension of RAINH in a liquid medium and removing frozen medium from the frozen suspension.
    Type: Grant
    Filed: April 7, 1989
    Date of Patent: March 13, 1990
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John D. Bolt, Walter Mahler, Frederick N. Tebbe, Robert J. Young, Jr.
  • Patent number: 4738798
    Abstract: A composition of matter comprising particles of semiconductor material in a copolymer matrix is disclosed.
    Type: Grant
    Filed: January 8, 1987
    Date of Patent: April 19, 1988
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Walter Mahler
  • Patent number: 4304685
    Abstract: In a process for polymerizing a 1-olefin with a catalyst system comprising a reaction product of a porous alumina and an organometallic compound of the formula (RCH.sub.2).sub.4 M wherein M is Ti, Zr, or Hf and R is a group which is such that there is no hydrogen atom attached to an atom which is in the .beta.-position to M, and more specifically, R is aryl, aralkyl, tertiary alkyl, for example, trialkylmethyl, or trialkylsilyl, the improvement characterized in that the alumina has an average pore diameter of at least about 150 A and/or at least about 10% of the total pore volume of the alumina is provided by pores having diameters greater than about 200 A.
    Type: Grant
    Filed: July 31, 1980
    Date of Patent: December 8, 1981
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Edward G. Howard, Jr., Walter Mahler
  • Patent number: 4230679
    Abstract: Particulate, porous, water-insoluble amorphous poly(silicic acid) which is characterized by an average pore diameter of at least 100 A and a surface area of 500 to 850 m.sup.2 /g, by an average pore diameter of 50 A to about 300 A and a surface area of greater than 850 m.sup.2 /g, or by a pore volume of 1.5 ml/g to about 8.5 ml/g and a surface area of greater than 850 m.sup.2 /g; process for preparing particulate, porous, water-insoluble, amorphous poly(silicic acid) by acidifying an appropriate aqueous silicate solution, allowing the silicic acid thus formed to polymerize to poly(silicic acid), freezing the acidified solution, and thereafter thawing the acidified solution and isolating therefrom, washing, drying and recovering particulate poly(silicic acid), said process further characterized in that:(a) the amount of silicate in the aqueous silicate solution is such that the SiO.sub.
    Type: Grant
    Filed: December 22, 1978
    Date of Patent: October 28, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Walter Mahler, William O. Forshey, Jr.
  • Patent number: 4213949
    Abstract: In a process for preparing particulate, porous, water-insoluble amorphous poly(alumino-silicate) having a Si/Al gram-atomic ratio of about 1:1 to 10:1, a pore volume of greater than 0.5 ml/g, an average pore diameter of 50 to 200 A and a surface area of 200 to 600 m.sup.2 /g by mixing an aqueous solution of an appropriate aluminate and an aqueous solution of an appropriate silicate, allowing the aluminate and silicate in the resultant mixture to polymerize to poly(alumino-silicate), freezing the mixture and thereafter isolating, washing, drying and recovering particulate poly(alumino-silicate) therefrom, said process characterized in that:(a) the amounts, respectively, of aluminate and silicate, calculated as Al.sub.2 O.sub.3 and SiO.sub.
    Type: Grant
    Filed: December 22, 1978
    Date of Patent: July 22, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Walter Mahler, William O. Forshey, Jr.
  • Patent number: 4213950
    Abstract: Process for preparing particulate, porous, amorphous water-insoluble poly(alumino-silicate) having a Si/Al ratio of 2:1 to 100:1, of high surface area, and in high yield, by mixing an aqueous solution of an alkali metal aluminate and an aqueous solution of silicic acid, allowing the aluminate and silicic acid in the resultant reaction mixture to polymerize to poly(alumino-silicate), and thereafter removing sufficient water from the reaction mixture to permit recovery of the particulate poly(alumino-silicate) therefrom; and particulate poly(alumino-silicate) prepared thereby.
    Type: Grant
    Filed: December 22, 1978
    Date of Patent: July 22, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Walter Mahler
  • Patent number: 4122041
    Abstract: Siliceous fibers characterized by being strong, water-insoluble, and porous, and having a five to seven-sided polygonal cross section are prepared by directionally freezing a quiescent body of aqueous polysilicic acid by subjecting it to a temperature of -5.degree. to -200.degree. C.
    Type: Grant
    Filed: July 1, 1977
    Date of Patent: October 24, 1978
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Walter Mahler
  • Patent number: 4068706
    Abstract: Chlorobenzenes with 2 to 5 chlorine substituents particularly trichlorobenzenes, can be used in a heat transfer method, particularly when contained in steel or aluminum vessels and at temperatures in the range of 260-450.degree. C, by contact with a thermal stabilizing amount of a solid acid acceptor selected fromA. a carbonate, phosphate, borate, or molybdate of an alkali metal or an alkaline earth metal orB. an oxide of zinc, cadmium or an alkaline earth metal.
    Type: Grant
    Filed: April 15, 1976
    Date of Patent: January 17, 1978
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Walter Mahler
  • Patent number: 3944494
    Abstract: Trichlorodifluorobenzene is thermally stabilized particularly in the presence of engineering metals by contacting it, especially when at temperatures greater than about 200.degree.C, with solid alkaline earth carbonates or with alkali or alkaline earth borates in a sufficient amount. The method is particularly useful in Rankine-cycle engines using trichlorodifluorobenzene as the working fluid, when the stabilizer is contained in the boiler.
    Type: Grant
    Filed: May 16, 1974
    Date of Patent: March 16, 1976
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Walter Mahler