Patents by Inventor Aaron Quoc Khieu

Aaron Quoc Khieu 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: 5880304
    Abstract: Organosilicon aldehydes and ketones are prepared by a method in which an organosilicon compound containing ozonide functionality is first formed by exposing an organosilicon compound containing unsaturation to ozone. The organosilicon compound containing ozonide functionality is then reduced to the corresponding organosilicon aldehyde or ketone with a reducing agent. One preferred reducing agent is a combination of zinc and acetic acid. Complete conversion of the ozonide to the carbonyl (.dbd.C.dbd.O) compound is obtained when the ozonide containing the reducing agent is heated briefly to about 30.degree. C.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: March 9, 1999
    Assignee: Dow Corning Corporation
    Inventors: Daniel Graiver, Aaron Quoc Khieu, Binh Thanh Nguyen
  • Patent number: 5789516
    Abstract: A method of manufacturing block copolymers containing a polyorganosiloxane segment, by dual polymerization involving (i) polycondensation of a silicone block followed by (ii) the free radical polymerization of a monomer that can be polymerized by free radical polymerization, such as a vinyl containing organic monomer. Initiation of free radical polymerization in step (ii) is carried out with a carbonyl functional group attached to the silicone polymer block. The carbonyl functional silicone polymer, preferably an aldehyde functional silicone polymer, is included as one component of a copper-based Redox initiating system. The method ensures no free homopolymerization, complete reactivity, and various polymer architectures are possible, including for example, polymeric structures such as AB, ABA, (AB).sub.n, brush, and radiant types. The method is fast, effective, convenient, and easier to control than typical ionic polymerization techniques.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: August 4, 1998
    Assignee: Dow Corning Corporation
    Inventors: Daniel Graiver, Aaron Quoc Khieu, Binh Thanh Nguyen
  • Patent number: 5789503
    Abstract: A method in which radical polymerization of a vinyl monomer is initiated by an ozonide group attached to a silane or a siloxane polymer. The method is particularly useful for preparing organic polymers having a silicone chain end, or for preparing wide ranges of silicone/organic polymers and copolymers with varied architecture, i.e., ABA block copolymers, comb polymers, star polymers, and hyper-branched polymers. In one embodiment, the method is carried out by simply heating a vinyl monomer in the presence of a silane containing ozonide functionality. The ozonide silane is obtained by exposing silanes or siloxanes having an alkyl group containing a double bond to ozone. Surprisingly, an ozonide attached to an organosilicon compound was found to be stable, and capable of initiating vinyl polymerization upon heating to moderate temperatures, i.e., about 70.degree. C.
    Type: Grant
    Filed: July 7, 1997
    Date of Patent: August 4, 1998
    Assignee: Dow Corning Corporation
    Inventors: Daniel Graiver, Aaron Quoc Khieu, Binh Thanh Nguyen
  • Patent number: 5739246
    Abstract: Polysiloxanes having pendant and/or telechelic carbonyl functionality, i.e., aldehyde functionality .tbd.Si--R--CH.dbd.O or ketone functionality .tbd.Si--R--CR.dbd.O, are manufactured in high yield by ozonolysis of polydiorganosiloxanes containing alkenyl groups, followed by treatment with a reducing agent such as zinc and acetic acid. The process is relatively fast and economical using readily available starting materials such as hexenyl-functional polymers. In particular, aldehyde functionality on the polymer can be used as a polymeric crosslinking agent.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: April 14, 1998
    Assignee: Dow Corning Corporation
    Inventors: Daniel Graiver, Aaron Quoc Khieu, Binh Thanh Nguyen
  • Patent number: 5708115
    Abstract: A method in which radical polymerization of a vinyl monomer is initiated by an ozonide group attached to a silane or a siloxane polymer. The method is particularly useful for preparing organic polymers having a silicone chain end, or for preparing wide ranges of silicone/organic polymers and copolymers with varied architecture, i.e., ABA block copolymers, comb polymers, star polymers, and hyper-branched polymers. In one embodiment, the method is carried out by simply heating a vinyl monomer in the presence of a silane containing ozonide functionality. The ozonide silane is obtained by exposing silanes or siloxanes having an alkyl group containing a double bond to ozone. Surprisingly, an ozonide attached to an organosilicon compound was found to be stable, and capable of initiating vinyl polymerization upon heating to moderate temperatures, i.e., about 70.degree. C.
    Type: Grant
    Filed: February 11, 1997
    Date of Patent: January 13, 1998
    Assignee: Dow Corning Corporation
    Inventors: Daniel Graiver, Aaron Quoc Khieu, Binh Thanh Nguyen