Piezoelectric composite material

Claim 2

A piezoelectric composite material comprising a mixture of one or more polymers and ferroelectric ceramic microcrystals, which contain 90% or more grains in a particle size range of about 1 to 400μ, at a ceramic microcrystals: one or more polymers mixing ratio of about 1:9 to 9:1 by volume, said ferroelectric ceramic microcrystals having virtually single domains.

Claim 3

A composite material as in claim 1, wherein said ferroelectric ceramic microcrystals contain as a basic composition a member selected from the group consisting of the following individual ferroelectric ceramics; I. Perovskite structures selected from (1) to (5): (1) barium titanate and solid solutions containing as the main component barium titanate; (2) lead titanate and solid solutions containing as the main component lead titanate; (3) lead titanate zirconate an solid solutions containing this salt as the main component; and (4) three-component ceramics consisting of solid solutions containing lead titanate zirconate and as a third component a salt of lead oxide and other metal oxides belonging to one of the following groups (a) to (f): (a) oxides represented by the formula: A.sup.2+ (B.sub.1/3.sup.2+. B.sub.2/3.sup.5+)O.sub.3 where A 2+ is Pb, Sr or Ba; B 2+ is Zn, Cd, Mg, Ni or Co and B 5+ is Nb or Ta; (b) oxides represented by the formula: A.sup.2+ (B.sub.1/2.sup.2+. B.sub.1/2.sup.6+) O.sub.3 where A 2+ is Pb; B 2+ is Cd, Mn, Zn, Mg, Co or Ni and B 6+ is W or Te; (c) oxides represented by the formula: A.sup.2+ (B.sub.1/2.sup.3+. B.sub.1/2.sup.5+)O.sub.3 where A 2+ is Pb, Ba or Ca; B 3+ is Fe, Sc, Cr, Yb, Lu or In and B 5+ is Nb or Ta; (d) oxides represented by the formula: A.sup.2+ (B.sub.2/3.sup.3+. B.sub.1/3.sup.6+)O.sub.3 where A 2+ is Pb; B 3+ is Fe and B 6 + is W; (e) oxides represented by the formula: A.sup.3+ (B.sub.1/2.sup.2+. B.sub.1/2.sup.4+)O.sub.3 where A 3+ is La or Nd; B 2+ is Mg and B 4+ is Ti; (f) oxides represented by the formula: (A.sub.1/2.sup.1+. A.sub.1/2.sup.3+)BO.sub.3 where A 1+ is Na or K; A 3+ is La, Ce, Nd or B is Ti; and (5) solid solutions containing NaNbO 3 ; II. tungsten bronze structures; III. bismuth layer structures; IV. LiNbO 3 or LiTaO 3; ceramics which contain as a basic composition one of the above PbTiO 3 containing ferroelectric ceramics, wherein a part of the Pb is replaced by an alkaline earth metal(s); ceramics which contain as a basic composition one of the above PbTiO 3 containing ferroelectric ceramics and further contain, as a supplemental component, one or more oxides selected from the following group I, II or III for the purpose of modification: I. Nb 2 O 5 , Ta 2 O 5 , La 2 O 3 , Sb 2 O 5 , Sb 2 O 3 , Bi 2 O 3 and WO 3 ; II. MgO, Fe 2 O 3 , Sc 2 O 3 and K 2 O; and III. Cr 2 O 3 , U 2 O 3 and MnO 2 ; and ceramics which contain as a basic composition one of the above Pb containing ferroelectric ceramics, wherein the Pb component is present in excess of the stoichiometric amount.

Claim 4

The composite material of claim 1, wherein said ferroelectric ceramic microcrystals are prepared by a solid phase reaction of appropriate mixed starting powders or salts under applied heat.

Claim 5

The composite material of claim 3, wherein said ferroelectric ceramic microcrystals are further subject to chemical etching.

Claim 6

The composite material of claim 1, wherein said polymer is a natural or synthetic rubber or resin selected from the group consisting of fluorine-containing rubber, chloroprene, polyvinylidine fluoride, acrylonitrile-butadiene-styrene copolymer, polyvinyl chloride and polyvinyl fluoride.

Claim 7

The composite material of claim 1, wherein said ferroelectric ceramic microcrystals are prepared by temporarily molding the appropriate mixed starting powders by a wet or dry molding, heating the resulting shaped product to cause a solid phase reaction or sintering, and rapidly cooling the reaction or sintering product to thereby pulverize it.

Claim 8

The composite material of claim 6, wherein said ferroelectric ceramic microcrystals are further subject to chemical etching.

Claim 9

The composite material of claim 1, wherein said ferroelectric ceramic microcrystals are prepared by heating the appropriate mixed starting powders to cause a solid phase reaction, pulverizing the resulting reaction product, temporarily shaping the resulting pulverized product, sintering the resulting temporarily shaped product and rapidly cooling the sintered temporarily shaped product to thereby pulverize it.

Claim 10

The composite material of claim 8, wherein said ferroelectric ceramic microcrystals are further subject to chemical etching.

Claim 11

The composite material of claim 1, wherein said ferroelectric ceramic microcrystals are prepared by thermally decomposing a coprecipitate of the appropriate mixed starting salts.

Claim 12

The composite material of claim 10, wherein said ferroelectric ceramic microcrystals are further subject to chemical etching.

Claim 13

The composite material of claim 1, wherein said ferroelectric ceramic microcrystals are prepared by heating the appropriate mixed starting powders to cause a solid phase reaction, shaping the resulting powdery product into a temporary form by dry or wet molding, sintering the resulting temporarily shaped product and further rapidly cooling the sintered temporarily shaped product to thereby pulverize it.

Claim 14

The composite material of claim 12, wherein said ferroelectric ceramic microcrystals are further subject to chemical etching.

Claim 15

The composite material of claim 1, wherein said ferroelectric ceramic microcrystals are prepared by temporarily molding the appropriate mixed starting powders and heating the temporary molding to cause a solid phase reaction, rapidly cooling the resulting reaction product to pulverize it, temporarily shaping the resulting pulverized product, repeating the solid phase reaction of the resulting temporarily shaped product and further rapidly cooling the reacted temporarily shaped product to thereby pulverize it.

Claim 16

The composite material of claim 14, wherein said ferroelectric ceramic microcrystals are further subject to chemical etching.

Claim 17

The composite material of claim 1, wherein said ferroelectric ceramic microcrystals are prepared by temporarily molding the appropriate mixed starting powders and heating the temporary molding to cause a sintering and rapidly cooling the resulting sintered product to pulverize it, temporarily shaping the resulting pulverized product, resintering the resulting temporarily shaped product and rapidly cooling the sintered temporarily shaped product to thereby pulverize it.

Claim 18

The composite material of claim 16, wherein said ferroelectric ceramic microcrystals are further subject to chemical etching.