COMPOSITE PIEZOELECTRIC MATERIAL AND METHOD OF ITS PRODUCTION Russian patent published in 2019 - IPC C04B35/493 C04B35/634 B32B27/06 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to composite piezoelectric materials (CPM) and can be used for making hydroacoustic receivers, medical ultrasonic diagnostics sensors, emission control, flaw detectors and other volumetric-sensitive piezoelectric transducers, as well as to the technology of making said materials. Composite piezoelectric material includes porous ceramic films of ferroelectric lead zirconate/titanate, or lead methanobate, or lead titanate, or solid solutions based thereon, connected to porous polymer films based on a silicone compound with electric resistance of not less than 10¹⁰ Ohm·cm. Ceramic film is obtained from a slurry composition, wt%: ultrafine powder of lead zirconate/titanate, or lead methanobate, or lead titanate, or solid solutions based thereon (active phase) 45.50-62.20, pore-forming agent: benzoic acid powder 2.95–12.40 or ammonium oxalate 3.20–13.8, distilled water 12.40–18.55, binder (50–65 % aqueous dispersion of ethyl acrylate, methyl acrylate copolymer and dibasic unsaturated carboxylic acid) 8.05–12.40, plasticizer (ethylene glycol or hexylene glycol) 1.10–4.20, dispersant (7–12 % aqueous solution of a copolymer of vinyl acetate and maleic acid, in which 0.8–1.5 equivalent carboxyl groups is neutralized with ammonia) 0.36–0.95, nonionic SAS1 (monoalkyl ethers of polyethylene glycol with molecular weight of 560–1,000) 0.07–0.15, nonionic SAS 2 (oxyethylated isononylphenol) 0.10–0.25, thickener (42–50 % aqueous dispersion of a copolymer of vinyl acetate, butyl acrylate and methacrylic acid or polyvinyl alcohol) 0.16–0.52, an antifoaming agent (alcohols propoxylate of fraction C₇-C₁₂) 0.03–0.33. Porous polymer film is obtained from mixture of composition, vol%: silicone compound with electric resistance of not less than 10¹⁰ Ohm·cm 70–80, foam stabilizer 0.001–0.005, white spirit and cresol – the rest at ratio of white spirit: cresol from 2:1 to 3:1 and 9:1. Method of proposed CPM manufacturing includes production of ceramic films (plates with thickness of up to 0.12–0.18 mm) from ultrafine powders of lead-containing ferroelectric phases with subsequent stepwise annealing, depositing electrodes on the lower and upper surfaces of the films, making porous polymer films based on the silicone compound, assembling the CPM by connecting the ceramic films with the partially polymerized polymer films, formation of two single parallel electrodes and terminal conductors connecting upper electrodes of separate active elements (AE) and lower electrodes of separate AE, followed by polarization of CPM AE and external sealing of CPM.

EFFECT: improving its elastic flexibility and reducing dielectric permittivity while simplifying its production method.

19 cl, 1 dwg, 1 tbl, 1 ex