Piezoelectric material filler, composite piezoelectric material, composite piezoelectric device, composite piezoelectric material filler, and method for producing alkali niobate compound

Patent metadata

Field	Value
Publication number	US-2019181330-A1
Application number	US-201716310988-A
Country	US
Kind code	A1
Filing date	Jun 19, 2017
Priority date	Jun 23, 2016
Publication date	Jun 13, 2019
Grant date	—

Abstract

Provided is a piezoelectric material filler including alkali niobate compound particles having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.460 to 0.495 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms. The present invention can provide a piezoelectric material filler having excellent piezoelectric properties, and a composite piezoelectric material including the piezoelectric material filler and a polymer matrix.

First claim

1 . A piezoelectric material filler comprising alkali niobate compound particles having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.460 to 0.495 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms.

2 . The piezoelectric material filler according to claim 1 , wherein the alkali niobate compound particles have an average particle size of 0.1 to 15 μm.

3 . The piezoelectric material filler according to claim 1 , wherein a ratio (Li/(Li+Na+K)) of the number of moles of lithium to the total number of moles of alkali metal elements in the alkali niobate compound particles is 0 or more and less than 0.10 in terms of atoms.

4 . A composite piezoelectric material comprising:
the piezoelectric material filler according to claim 1 ; and a polymer matrix.

5 . A composite piezoelectric device comprising:
the composite piezoelectric material according to claim 4 which has been polarized.

6 . A composite piezoelectric material comprising:
a polymer matrix; and a piezoelectric material filler dispersed in the polymer matrix, wherein the piezoelectric material filler comprises alkali niobate compound particles having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.460 to 0.495 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms.

7 . The composite piezoelectric material according to claim 6 , wherein
a content of the composite piezoelectric material filler is 20 to 80 vol % based on the entire composite piezoelectric material.

8 . The composite piezoelectric material according to claim 6 , wherein
a ratio (Li/(Li+Na+K)) of the number of moles of lithium to the total number of moles of alkali metal elements in the alkali niobate compound particles is 0 or more and less than 0.10 in terms of atoms.

9 . A composite piezoelectric device comprising:
the composite piezoelectric material according to claim 6 which has been polarized.

10 . A composite piezoelectric material comprising:
a polymer matrix; and a composite piezoelectric material filler dispersed in the polymer matrix, wherein the composite piezoelectric material filler comprises:
a small-particle size filler comprising an alkali niobate compound having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.40 to 0.60 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms; and
a large-particle size filler comprising an alkali niobate compound having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.40 to 0.60 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms,
a total content of the small-particle size filler and the large-particle size filler is 20 to 80 vol % based on the entire composite piezoelectric material, the small-particle size filler has an average particle size (D50) of 0.1 to 1.2 μm, the large-particle size filler has an average particle size (D50) of 1 to 15 μm, and a content ratio of the large-particle size filler to the small-particle size filler (large-particle size filler:small-particle size filler) is 10:90 to 90:10 by volume.

11 . The composite piezoelectric material according to claim 10 , wherein the small-particle size filler has a BET specific surface area of 2 to 15 m 2 /g, and the large-particle size filler has a BET specific surface area of 0.1 to 3 m 2 /g.

12 . The composite piezoelectric material according to claim 10 , wherein a ratio (large-particle size filler/small-particle size filler) of the average particle size (D50) of the large-particle size filler to the average particle size (D50) of the small-particle size filler is 2 to 150.

13 . The composite piezoelectric material according to claim 10 , wherein
a ratio (Li/(Li+Na+K)) of the number of moles of lithium to the total number of moles of alkali metal elements in the small-particle size filler is 0 or more and less than 0.10 in terms of atoms, and a ratio (Li/(Li+Na+K)) of the number of moles of lithium to the total number of moles of alkali metal elements in the large-particle size filler is 0 or more and less than 0.10 in terms of atoms.

14 . A composite piezoelectric device comprising:
the composite piezoelectric material according to claim 10 which has been polarized.

15 . A composite piezoelectric material comprising:
a polymer matrix; and a composite piezoelectric material filler dispersed in the polymer matrix, wherein the composite piezoelectric material filler comprises an alkali niobate compound having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.40 to 0.60 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms, a content of the alkali niobate compound is 20 to 80 vol % based on the entire composite piezoelectric material, and the alkali niobate compound exhibits a bimodal particle size distribution including a first peak having a peak top in a particle size range of 0.1 to 1.2 μm and a second peak having a peak top in a particle size range of 1 to 15 μm in a particle size distribution measurement, wherein a ratio (B/A) of a value (B) of a frequency (%) of a particle size at the peak top of the second peak to a value (A) of a frequency (%) of a particle size at the peak top of the first peak is 0.1 to 20.

16 . The composite piezoelectric material according to claim 15 , wherein a ratio (the particle size at the peak top of the second peak/the particle size at the peak top of the first peak) of the particle size at the peak top of the second peak to the particle size at the peak top of the first peak is 2 to 150.

17 . The composite piezoelectric material according to claim 15 , wherein a ratio (Li/(Li+Na+K)) of the number of moles of lithium to the total number of moles of alkali metal elements in the alkali niobate compound is 0 or more and less than 0.10 in terms of atoms.

18 . A composite piezoelectric device comprising:
the composite piezoelectric material according to claim 15 which has been polarized.

19 . A composite piezoelectric material filler comprising a mixture of:
a small-particle size filler comprising an alkali niobate compound having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.40 to 0.60 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms; and a large-particle size filler comprising an alkali niobate compound having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.40 to 0.60 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms, wherein the small-particle size filler has an avera

Assignees

• Nippon Chemical Ind

Inventors

• Tanabe Shinji
• Kunita Hajime
• Kikuchi Shunsuke

Classifications

• C01P2004/03

  obtained by SEM · CPC title

• C01P2004/51

  Particles with a specific particle size distribution · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• C01P2004/53

  bimodal size distribution · CPC title