Patents Examined by Caixia Ru
  • Patent number: 6218497
    Abstract: An organohydridosiloxane polymer having a cage conformation, between approximately 0.1 to 40 mole percent carbon-containing substituent, and a dielectric constant of less than about 3.0 is disclosed. Each silicon atom of the cage polymer is bonded to at least three oxygen atoms and to either a hydrogen atom or an organic substituent. By providing such a caged structure having essentially no hydroxyl or alkoxy substituents, either on the polymer backbone or at terminal silicon atoms, essentially no chain lengthening polymerization can occur in solution. Such organohydridosiloxane resins having a molecular weight in the range from about 400 to about 200,000 atomic mass units were formed using a dual phase solvent system and either a solid phase or a phase transfer catalyst to assist the condensation of hydridotrihalosilane with at least one organotrihalosilane.
    Type: Grant
    Filed: March 20, 1998
    Date of Patent: April 17, 2001
    Assignee: AlliedSignal Inc.
    Inventors: Nigel P. Hacker, Scott Lefferts, Lisa Figge