Patents by Inventor Sajal Das

Sajal Das 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: 5194331
    Abstract: The present invention is a fiber comprising cyanato group containing phenolic resin comprising repeating units of the formula: ##STR1## wherein p is 0 or an integer of one or more, q is O or an integer of 1 or more, X is a radical selected from the group consisting of: --CH.sub.2 --, --CO--, --SO.sub.2 --, ##STR2## and R is the same or different and is selected from the group consisting of hydrogen and methyl radicals. The fiber of the present invention can be made a phenolic triazine derived from the cyanato group containing phenolic resin.
    Type: Grant
    Filed: September 16, 1991
    Date of Patent: March 16, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 5137989
    Abstract: The present invention is directed to a process of preparing a cyanato group containing phenolic resin by reacting the corresponding phenolic resin with a tertiary amine in a water immiscible, non-hydrogen bonding solvent at a temperature of preferably less than about 25.degree. C. to form the corresponding ammonium salt of the phenolic resin; and reacting the ammonium salt with a cyanogen halide at a temperature equal to or less than about 0.degree. C. in said solvent to form the cyanato containing phenolic resin.
    Type: Grant
    Filed: September 1, 1989
    Date of Patent: August 11, 1992
    Assignee: Allied-Signal Inc.
    Inventor: Sajal Das
  • Patent number: 5130385
    Abstract: The present invention is a cyanato group containing phenolic resin, and to phenolic triazine resins derived therefrom. The cyanato group containing phenolic resin of the present invention can be completely cured to form a phenolic triazine resin having a glass transition temperature equal to or greater than 250.degree. C.
    Type: Grant
    Filed: September 14, 1990
    Date of Patent: July 14, 1992
    Assignee: Allied-Signal Inc.
    Inventor: Sajal Das
  • Patent number: 5126412
    Abstract: The present invention is a cyanato group containing phenolic resin, and to phenolic triazine resins derived therefrom. The resin of the present invention is stable and has a long shelf life. This is indicated by the gel time of greater than 3 minutes and by a shelf life equal to or greater than 3 days.
    Type: Grant
    Filed: September 6, 1990
    Date of Patent: June 30, 1992
    Assignee: Allied-Signal Inc.
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 5109078
    Abstract: The present invention is a cyanato group containing phenolic resin of the formula: ##STR1## wherein n is 0 or an integer of one or more, and R is the same or different and is selected from the group consisting of hydrogen and methyl radicals. The advancement over the art is that the resin of the present invention is stable and has a long shelf life. This is indicated by the gel time of greater than 1 minute, preferably greater than 2 minutes, more preferably greater than 10 minutes, and most preferably greater than 20 minutes at 155.degree. C. Alternately, the improved resin of the present invention can be characterized as having a thermal stability indicated by thermal decomposition temperature of at least 400.degree. C. and preferably of at least 450.degree. C. as measured by Thermal Gravimetric Analysis (TGA).
    Type: Grant
    Filed: April 1, 1991
    Date of Patent: April 28, 1992
    Assignee: Allied-Signal Inc.
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 5043214
    Abstract: The present invention is flame resistant article and related method, made of phenolic triazine resin derived from a cyanato group containing phenolic resin of the formula: ##STR1## wherein: n is a positive whole number greater than or equal to 1;q and r are the same or different at each occurrence and are whole numbers from 0 to 3, with the proviso that the sum of q and r at each occurrence is equal to 3;Z is --CN, or hydrogen and --CN;o and p are the same or different at each occurrence and are whole numbers from 0 to 4 with the proviso that the sum of o and p at each occurrence is equal to 4;--X-- is a divalent organic radical; andR.sub.3 is the same or different at each occurrence and is a substituent other than hydrogen which is unreactive under conditions necessary to completely cure the copolymer.
    Type: Grant
    Filed: February 26, 1990
    Date of Patent: August 27, 1991
    Assignee: Allied-Signal Inc.
    Inventors: Sajal Das, Dusan C. Prevorsek, Raj Sharma, Bruce DeBona
  • Patent number: 5004788
    Abstract: The present invention is a cyanato group containing phenolic resin of the formula: ##STR1## wherein n is 0 or an integer of one or more, and R is the same or different and is selected from the group consisting of hydrogen and methyl radicals. The advancement over the art is that the resin of the present invention is stable and has a long shelf life. This is indicated by the gel time of greater than 1 minute, preferably greater than 2 minutes, more preferably greater than 10 minutes, and most preferably greater than 20 minutes at 155.degree. C. Alternately, the improved resin of the present invention can be characterized as having a thermal stability indicated by thermal decomposition temperature of at least 400.degree. C. and preferably of at least 450.degree. C. as measured by Thermal Gravimetric Analysis (TGA).
    Type: Grant
    Filed: March 1, 1989
    Date of Patent: April 2, 1991
    Assignee: Allied-Signal Inc.
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 4988780
    Abstract: The present invention is flame resistant article and related method, made of phenolic triazine resin derived from a cyanato group containing phenolic resin of the formula: ##STR1## wherein: n is a positive whole number greater than or equal to 1;q and r are the same or different at each occurrence and are whole numbers from 0 to 3, with the proviso that the sum of q and r at each occurrence is equal to 3;Z is --CN, or hydrogen and --CN;o and p are the same or different at each occurrence and are whole numbers from 0 to 4 with the proviso that the sum of o and p at each occurrence is equal to 4;--X-- is a divalent organic radical; andR.sub.3 is the same or different at each occurrence and is a substituent other than hydrogen which is unreactive under conditions necessary to completely cure the copolymer.
    Type: Grant
    Filed: August 15, 1988
    Date of Patent: January 29, 1991
    Assignee: Allied-Signal
    Inventors: Sajal Das, Dusan C. Prevorsek, Raj Sharma, Bruce DeBona
  • Patent number: 4978727
    Abstract: The present invention is a cyanato group containing phenolic resin, and method to prepare the resin. The resin of the present invention is stable and has a long shelf life. This is indicated by the gel time of greater than 1 minute, preferably greater than 2 minutes, more preferably greater than 10 minutes. The resin has substantially no smoke generation during gel time measurement at 155.degree. C.
    Type: Grant
    Filed: April 12, 1988
    Date of Patent: December 18, 1990
    Assignee: Allied-Signal
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 4970276
    Abstract: Phenolic cyanate/phenolic triazine copolymers and cured resins prepared therefrom.
    Type: Grant
    Filed: May 26, 1989
    Date of Patent: November 13, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 4920159
    Abstract: The present invention is a composition comprising a friction resistant filler and a cyanato group containing phenolic resin which has repeating units of the formula: ##STR1## wherein p is 0 or an integer of one or more, q is an integer of one or more, and X is a radical selected from the group consisting of: --CH.sub.2 --, --CO--, --SO.sub.2 --, ##STR2## with --CH.sub.2 -- preferred. R is the same or different and is selected from the group consisting of hydrogen and methyl radicals and composition based on phenolic triazine resins derived therefrom.
    Type: Grant
    Filed: January 11, 1989
    Date of Patent: April 24, 1990
    Assignee: Allies-Signal Inc.
    Inventors: Sajal Das, Dusan C. Prevorsek, Seong K. Rhee, William J. Bulger
  • Patent number: 4851279
    Abstract: The present invention is a fiber comprising cyanato group containing phenolic resin comprising repeating units of the formula: ##STR1## wherein p is 0 or an integer of one or more, q is 0 or an integer of 1 or more, X is a radical selected from the group consisting of: --CH.sub.2 --, --CO--, --SO.sub.2 --, ##STR2## and R is the same or different and is selected from the group consisting of hydrogen and methyl radicals. The fiber of the present invention can be made a phenolic triazine derived from the cyanato group containing phenolic resin.
    Type: Grant
    Filed: December 21, 1987
    Date of Patent: July 25, 1989
    Assignee: Allied-Signal Inc.
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 4831086
    Abstract: The present invention is a cyanato group containing phenolic resin of the formula: ##STR1## wherein n is 0 or an integer of one or more, and R is the same or different and is selected from the group consisting of hydrogen and methyl radicals. The advancement over the art is that the resin of the present invention is stable and has a long shelf life. This is indicated by the gel time of greater than 1 minute, preferably greater than 2 minutes, more preferably greater than 10 minutes, and most preferably greater than 20 minutes at 155.degree. C. Alternately, the improved phenolic triazine resin of the present invention can be characterized as having a thermal stability indicated by thermal decomposition temperature of at least 400.degree. C. and preferably of at least 450.degree. C. as measured by Thermal Gravimetric Analysis (TGA).
    Type: Grant
    Filed: October 5, 1987
    Date of Patent: May 16, 1989
    Assignee: Allied-Signal Inc.
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 4771113
    Abstract: Modified phenolic resins and cured resins prepared therefrom.
    Type: Grant
    Filed: June 15, 1987
    Date of Patent: September 13, 1988
    Assignee: Allied Corporation
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 4757118
    Abstract: Modified phenolic resins and cured resins prepared therefrom.
    Type: Grant
    Filed: January 23, 1986
    Date of Patent: July 12, 1988
    Assignee: Allied Corporation
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 4650838
    Abstract: Modified phenolic resins and cured resins prepared therefrom.
    Type: Grant
    Filed: January 23, 1986
    Date of Patent: March 17, 1987
    Assignee: Allied Corporation
    Inventors: Sajal Das, Dusan C. Prevorsek
  • Patent number: 4650839
    Abstract: Modified phenolic resins and cured resins prepared therefrom.
    Type: Grant
    Filed: January 23, 1986
    Date of Patent: March 17, 1987
    Assignee: Allied Corporation
    Inventors: Sajal Das, Dusan C. Prevorsek