Electrically-conductive compositions
An electrically-conductive composition can be used with piezoelectric materials to enhance the piezoelectric effects. This composition essentially has (a) an electrically-conductive material; (b) particles having a Young's modulus that is different from the Young's modulus of the (a) electrically-conductive material by at least 10%, and which (b) particles have a d50 of at least 500 nm and up to and including 500 μm and a polydispersity coefficient that is less than or equal to 3; and (c) a non-electrically-conductive binder material. The weight ratio of the (b) particles to the (a) electrically-conductive material is at least 0.01:1 and up to and including 10:1. When the composition is coated and dried on an insulating substrate, a resulting dried composition exhibits a resistivity of less than 10,000 ohm-cm.
1. A composition consisting essentially of:
(a) an electrically-conductive material;
(b) particles having a Young's modulus that is different from the Young's modulus of the (a) electrically-conductive material by at least 10%, and which (b) particles have a d50 of at least 500 nm and up to and including 500 μm and a polydispersity coefficient that is less than or equal to 3; and
(c) a non-electrically-conductive binder material,
provided that:
the weight ratio of the (b) particles to the (a) electrically-conductive material is at least 0.01:1 and up to and including 10:1, and
when the composition is coated and dried on an insulating substrate, a resulting dried composition exhibits a resistivity of less than 10,000 ohm-cm, and
optionally, the composition further including a (d) solvent medium.
2. The composition of claim 1 , wherein the (a) electrically-conductive material exhibits an electrical conductivity of at least 2×10 4 S/m as measured by a Van der Pauw 4 probe method.
3. The composition of claim 1 , wherein the (a) electrically-conductive material comprises electrically-conductive metallic particles dispersed within the (d) solvent medium that is present, which electrically-conductive metallic particles have a median equivalent spherical volume diameter of at least 1 nm and up to and including 1000 μm and a polydispersity coefficient that is less than or equal to 2.
4. The composition of claim 1 , wherein the (a) electrically-conductive material comprises one or more of silver, gold, titanium, platinum, palladium, copper, nickel, and a form of electrically-conductive carbon.
5. The composition of claim 1 , wherein the (a) electrically-conductive material is an electrically-conductive organic polymer.
6. The composition of claim 1 , wherein the (a) electrically-conductive material is present in an amount of at least 5 weight % and up to and including 80 weight %, based on the total weight of the composition.
7. The composition of claim 1 , wherein the (b) particles are composed of one or more polymeric materials.
8. The composition of claim 1 , wherein the (b) particles comprise one or more elastomeric polymers.
9. The composition of claim 1 , wherein the (b) particles are core-shell particles having a core that is comprised of a material different from that of the material comprising the shell.
10. The composition of claim 1 , wherein the (b) particles are composed of an inorganic material.
11. The composition of claim 1 , wherein the (b) particles are present at greater than 0 volume % and up to and including 88 volume %, based on the total wet volume of the composition.
12. The composition of claim 1 , wherein the (b) particles are present in at least 8 volume % and up to and including 50 volume %, based on the total wet volume of the composition.
13. The composition of claim 1 , wherein the (d) solvent medium is present and comprises at least 70 weight % water, based on the total weight of the (d) solvent medium.
14. The composition of claim 1 , wherein the (d) solvent medium is present in an amount of at least 4 weight % and up to and including 90 weight %, based on the total weight of the composition.
15. The composition of claim 1 , wherein the (d) solvent medium is present in an amount of at least 4 weight % and up to and including 40 weight %, based on the total weight of the composition, and the (d) solvent medium comprises at least 90 weight % water based on the total weight of the (d) solvent medium.
16. The composition of claim 1 , wherein the (c) binder material comprises one or more preformed polymeric materials, each of which has a weight average molecular weight of at least 5,000.
17. The composition of claim 1 , wherein the (c) binder material comprises one or more polyurethanes, acrylate polymers, polyvinyl acetals, or polyacrylate precursors to an acrylate polymer.
18. The composition of claim 1 , wherein the (c) binder material is present in an amount of at least 0.05 weight % and up to and including 5 weight %, based on the total weight of the composition.
19. The composition of claim 1 , wherein the (b) particles have a polydispersity coefficient that is less than or equal to 1.5.
20. The composition of claim 1 , wherein the (b) particles have a polydispersity coefficient that is less than or equal to 1.25.