Stretchable conductor sheet and paste for forming stretchable conductor sheet

Abstract

A first object of the present invention is to provide a stretchable conductor sheet that exhibits isotropic conductivity when stretched in a predetermined direction or in a direction perpendicular to the predetermined direction, and a paste for forming a stretchable conductor sheet, which is used for the stretchable conductor sheet. A second object of the present invention is to provide a stretchable conductor sheet having a small change in specific resistance even when repeatedly twisted, and a paste for forming a stretchable conductor sheet, which is used for the stretchable conductor sheet. A third object of the present invention is to provide a stretchable conductor sheet having a small change in specific resistance even when repeatedly washed, and a paste for forming a stretchable conductor sheet, which is used for the stretchable conductor sheet. The first object of the present invention can accomplish a stretchable conductor sheet having a thickness of 3 to 800 μm, the stretchable conductor sheet comprising at least conductive particles, inorganic particles surface-treated with a hydroxide and/or an oxide of one or both of Al and Si, and a flexible resin having a tensile elastic modulus of 1 MPa or more and 1000 MPa or less, wherein in each of two orthogonal directions, a specific resistance change ratio of the sheet at a time of elongation by 40% with respect to an original length is less than ±10% in an elongation direction.

1 - 11 . (canceled) 
     
     
         12 . A stretchable conductor sheet comprising
 at least conductive particles, and   a flexible resin having a tensile elastic modulus of 1 MPa or more and 1000 MPa or less,   the stretchable conductor sheet having a void ratio of 10% by volume or more and 50% by volume or less.   
     
     
         13 . The stretchable conductor sheet according to  claim 12 ,
 wherein the conductive particles are aggregated silver particles having an average particle diameter of 0.8 to 10 μm,   the stretchable conductor sheet further includes inorganic particles having an aspect ratio of less than 1.5, and an average particle diameter of 0.5 times or less the average particle diameter of the aggregated silver particles,   the stretchable conductor sheet has a thickness of 3 to 800 μm, and   a specific resistance after compression by 10% is repeated 100 times is 2.4 times or less an initial specific resistance.   
     
     
         14 . The stretchable conductor sheet according to  claim 12 ,
 wherein the inorganic particles are surface-treated with a hydroxide and/or an oxide of one or both of Al and Si.   
     
     
         15 . The stretchable conductor sheet according to  claim 12 ,
 wherein the inorganic particles are contained in an amount of 2.0 to 30% by mass based on 100% by mass of a total of the aggregated silver particles and the inorganic particles.   
     
     
         16 . The stretchable conductor sheet according to  claim 12 ,
 wherein the inorganic particles have an average particle diameter smaller than an average particle diameter of the aggregated silver particles.   
     
     
         17 . (canceled)