Patent EP0247734A2 successfully refreshed from Google Patents.
EP0247734A2
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EP
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Piezoelectric composite materials and method of making
Assignee: Lockheed Martin Corp
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Filing: 1987-04-28
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Granted: —
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Expires: 2007-04-28
Abstract
Abstract A piezoelectric composite material having increased sensitivity and stability with time is described. The composite includes a volume fraction of from 20 to 60 percent of piezoelectric crystals having a size distribution of from 1 to 300 microns dispersed in a polymer matrix. The composite matrix is characterized by a shear modulus of at least 50 psi.
Inventors
- 👤 William P. Krug
- 👤 Meredith A. Aronson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 03:38
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; C08G18/28; C08G18/67; C08G18/69; H; H10; H10N; H10N30/00; H10N30/01; H10N30/09; H10N30/092; H10N30/80; H10N30/85; H10N30/852
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
50 words
A composite piezoelectric material comprising particles of a piezoelectric material dispersed in a polymer matrix; the piezoelectric particles having a volume fraction of at least 20 percent and particle size distribution in the range of 1-300 micron; and the polymer matrix having a Young's modulus of at least 150 psi.
Claim 2
Dependent Claim
50 words
A composite piezoelectric material comprising particles of a piezoelectric material dispersed in a polymer matrix; the piezoelectric particles having a volume fraction of at least 20 percent and particle size distribution in the range of 1-300 micron; and the polymer matrix having a Young's modulus of at least 150 psi.
Claim 3
Dependent Claim
18 words
The composite of claim 1 wherein said polymer matrix has a Young's modulus of at least 500 psi.
Claim 4
Dependent Claim
62 words
The composite of claim 1 wherein the piezoelectric crystal is selected from the group consisting of tartaric acid, mono- saccharides and di- saccharides and carboxylate salts that do not substantially change hydration level or crystal phase in the desired temperature range of application and which are members of the crystal class 1, 2, 3, 4, 6, m, 2mm, 4mm, 3m, and 6mm.
Claim 5
Dependent Claim
20 words
The composite of claim 3 wherein the polymer is selected from the group of medium to high molecular weight polyurethanes.
Claim 6
Dependent Claim
13 words
The composite of claim 3 wherein the polymer is a polybutadiene based polyurethane.
Claim 7
Dependent Claim
21 words
The composite of claim 1 wherein the volume percent of piezoelectric crystals is in the range of 20 to 60 percent.
Claim 8
Dependent Claim
16 words
The composite of claim 1 wherein the volume percent of piezoelectric crystals is approximately 50 percent.
Claim 9
Dependent Claim
17 words
The composite of claim 1 wherein said composite has a Young's modulus of at least 5,000 psi.
Claim 10
Dependent Claim
17 words
The composite of claim 1 wherein said composite has a Young's modulus of at least 15,000 psi.
Claim 11
Dependent Claim
17 words
The composite of claim 1 wherein said composite has a Young's modulus of at least 30,000 psi.
Claim 12
Independent Claim
48 words
A method of making a composite piezoelectric material comprising the steps of: a) dispersing a quantity of particles of a piezoelectric material in a prepolymer mixture containing a plasticizer to form a composite; b) poling the composite; c) curing the composite; d) removing the plasticizer from the composite;
Claim 13
Independent Claim
48 words
A method of making a composite piezoelectric material comprising the steps of: a) dispersing a quantity of particles of a piezoelectric material in a prepolymer mixture containing a plasticizer to form a composite; b) poling the composite; c) curing the composite; d) removing the plasticizer from the composite;
Claim 14
Dependent Claim
22 words
wherein the composite contains at least 20 volume percent of piezoelectric particles having a size distribution in the range of 1-300 microns.
Claim 15
Dependent Claim
22 words
wherein the composite contains at least 20 volume percent of piezoelectric particles having a size distribution in the range of 1-300 microns.
Claim 16
Dependent Claim
23 words
The method of claim 11 wherein the piezoelectric material is selected from the group consisting of tartaric acids, mono- saccharides and di- saccharides.
Claim 17
Dependent Claim
13 words
The method of claim 12 wherein the composite is degassed prior to poling.
Claim 18
Dependent Claim
19 words
The method of claim 13 wherein the plasticizer is removed from the composite by submersion in a silicone fluid.
Claim 19
Dependent Claim
17 words
Th method of claim 14 wherein the prepolymer mixture comprises a medium to high molecular weight polyurethane.
Claim 20
Dependent Claim
14 words
The method of claim 14 wherein the prepolymer mixture comprises a polybutadiene based polyurethane.
Claim 21
Dependent Claim
19 words
The method of claim 8 wherein the volume percent of piezoelectric crystals is in the range of 20-60 percent.
Claim 22
Dependent Claim
16 words
The method of claim 8 wherein the volume percent of piezoelectric crystals is approximately 50 percent.
References Cited (Backward Citations)
No citation records indexed.
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