Patents by Inventor Alessandro Stopponi

Alessandro Stopponi 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).

  • Hollow fibres of modified poly-(2,6-dimethyl-p-oxy-phenylene)
    Patent number: 5175196
    Abstract: A hollow fiber of amorphous, hydroxy-ethylated poly-(2,6-dimethyl-p-oxyphenylene) (PPO-OH) with a glass transition temperature (Tg) of from 180.degree. to 200.degree. C. is disclosed, which is formed by a high-density, microporous layer on a macroporous backing, and having an outer diameter comprised within the range of from 450 to 550 .mu.m and an inner diameter comprised within the range of from 250 to 400 .mu.m.The process for preparing the hollow fibre and the use of said fibre in the processes of separation of gas mixtures are disclosed as well.
    Type: Grant
    Filed: June 12, 1992
    Date of Patent: December 29, 1992
    Assignee: Eniricerche S.p.A.
    Inventors: Alessandro Stopponi, Claudio Demofonti, Claudio Valentini, Raffaello Sisto, Ugo Pedretti
  • Modified poly(2,6-dimethyl-p-oxyphenylene), a process for its preparation and its use in gas mixture separation membranes
    Patent number: 5171794
    Abstract: An amorphous modified poly(2,6-dimethyl-p-oxyphenylene) (PPO) is described with a glass transition temperature (Tg) within the range of 170.degree.-220.degree. C., of which the macromolecules contain units having trialkylsilyl groups bonded to the nucleus and/or to the methyl: ##STR1## together with units having hydroxyethyl groups bonded to the nucleus and/or to the methyl: ##STR2## This modified PPO is prepared by metalating PPO with a metalating agent and reacting the formed metalated PPO with a trialkylsilyl halide and with ehtylene oxide in succession.The use of the thus modified PPO for the preparation of flat, including asymmetric, membranes useful in gas mixture separation processes is described.
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: December 15, 1992
    Assignees: Eniricerche S.p.A., Snam S.p.A., Agip Petroli S.p.A.
    Inventors: Amalia Assogna, Alberto Gandini, Arnaldo Roggero, Raffaello Sisto, Alessandro Stopponi, Claudio Valentini
  • Process for preparing modified poly-(2,6-dimethyl-p-oxyphenylene)
    Patent number: 5169416
    Abstract: A process for preparing a modified, amorphous poly-(2,6-dimethyl-p-oxyphenylene) (PPO) comprises:(a) metalating PPO with a metalating agent, and(b) functionalizing such a metalated PPO by reacting the PPO with a trialkylsilyl halide and/or ethylene oxide; and is characterized in that the reaction of metalation is carried out in an inert liquid vehicle which contains PPO in an at least partially suspended solid form, by operating under metalating conditions of gradually adding metalating agent to such a suspension, either continuously or as discrete portions. Depending on the functionalizing agents used, and on the sequence of addition thereof, the process makes it possible to obtain PPO polymers which are modified with trialkyl-silyl, hydroxyethylene and/or ethyleneoxytrialkyl-silyl functional groups. The modified PPO polymers are particularly suitable for preparing flat membranes, including asymmetrical membranes, for the separation of gas mixtures.
    Type: Grant
    Filed: December 6, 1990
    Date of Patent: December 8, 1992
    Assignees: Snam S.p.A., Eniricerche S.p.A., Agip Petroli S.p.A.
    Inventors: Ugo Pedretti, Alberto Gandini, Arnaldo Roggero, Raffaello Sisto, Claudio Valentini, Amalia Assogna, Alessandro Stopponi