Patent EP-2511314-A1 (EP)
Inventor: JENNINGER WERNER DR
IPC: H01L41/193
Filed: 2011-04-12
Abstract: Electromechanical transducer comprises a dielectric elastomer contacted with a first electrode and a second electrode, where: the dielectric elastomer comprises a polyurethane polymer; the polyurethane polymer is obtained by reacting (A) polyisocyanate and/or isocyanate terminated prepolymer and (B) at least one isocyanate reactive compound; and the isocyanate terminated prepolymer is e.g. (A1) an isocyanate terminated prepolymer based on polyisoycanate and polyether polyol with a functionality of 2 and (B) is e.g. (B1) polyether polyol with a functionality of 2. Electromechanical transducer comprises a dielectric elastomer contacted with a first electrode and a second electrode, where: the dielectric elastomer comprises a polyurethane polymer; the polyurethane polymer is obtained by reacting (A) polyisocyanate and/or isocyanate terminated prepolymer and (B) at least one isocyanate reactive compound; the isocyanate terminated prepolymer is (A1) an isocyanate terminated prepolymer based on polyisoycanate and polyether polyol, where the polyether polyol exhibits a functionality of 2, a hydroxyl number of 3-150 mg potassium hydroxide/g and a polydispersity of greater than 1 to = 1.2 by gel permeation chromatography in tetrahydrofuran with polystyrene standards, (A2) an isocyanate terminated prepolymer based on polyisoycanate and polyether polyol, where the polyether polyol exhibits a functionality of greater than 2 to 8, a hydroxyl number of 3-150 mg potassium hydroxide/g and a polydispersity of greater than 1 to = 1.2 by gel permeation chromatography in tetrahydrofuran with polystyrene standards, (A3) an isocyanate terminated prepolymer with allophanate, biuret, isocyanurate, urethane and/or urea group based polyisoycanate and polyether polyol, where the polyether polyol exhibits a functionality of 2, a hydroxyl number of 3-150 mg potassium hydroxide/g and a polydispersity of greater than 1 to = 1.2 by gel permeation chromatography in tetrahydrofuran with polystyrene standards, or (A4) an isocyanate terminated prepolymer with allophanate, biuret, isocyanurate, urethane and/or urea group based polyisoycanate and polyether polyol, where the polyether polyol exhibits a functionality of greater than 2 to 8, a hydroxyl number of 3-150 mg potassium hydroxide/g and a polydispersity of greater than 1 to = 1.2 by gel permeation chromatography in tetrahydrofuran with polystyrene standards; (B) is (B1) polyether polyol with a functionality of 2, a hydroxyl number of 3-150 mg potassium hydroxide/g and a polydispersity of greater than 1 to = 1.2 by gel permeation chromatography in tetrahydrofuran with polystyrene standards, (B2) polyether polyol with a functionality of greater than 2 to 8, preferably 2-4, a hydroxyl number of 3-150 mg potassium hydroxide/g and a polydispersity of greater than 1 to = 1.2 by gel permeation chromatography in tetrahydrofuran with polystyrene standards or (B3) low molecular weight, monomeric di-, tri- and/or tetra-ol or di- and/or triamine; in the preparation of (A) no further isocyanate reactive compounds are used in addition to the polyether polyol; in the preparation of the polyurethane polymer no further isocyanate-reactive compounds are used in addition to (B); at least one of (A) and (B) exhibits a functionality of >= 3; (A1) and (A2) are not used in mixture with (A); (B1) and/or (B2) are not used in mixture with (B3); in case of the reacting (A3) with (B1) and/or (B2), the molecular weight of the polyether polyol in (A3) is equal to the molecular weight of (B1) and/or equivalent weight of (B2); in case of reacting (A4) with (B1) and/or (B2), the equivalent weight of the polyether polyol contained in (A4) is equal to the molecular weight of (B1) and/or equivalent weight of (B2); and in case of reacting a mixture of (A3) and (A4) with (B1) and/or (B2), the molecular weight of the polyether polyol in (A3) is equal to the equivalent weight of the polyether polyol in (A4), the molecular weight of (B1) and/or the equivalent weight of (B2). An independent claim is included for the preparation of the electromechanical transducer comprising providing the first electrode and second electrode, providing the dielectric elastomer and placing the dielectric elastomer between the first electrode and the second electrode.