Soft conductive materials
AssigneeMinnesota Mining and Manufacturing Company
InventorRichard W. Oehmke
Life of this patent
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Abstract
A soft, conformable, conductive composition comprises a polymeric binder system; a purality of insoluble, soft, spherical, deformable, generally nonreactive domains dispersed in the system interjacent the domains, held in the matrix thereof, such that at least one electrically conductive pathway is formed through said composition. The conformable, conductive composition has many applications where a moldable, pliable, adherent conductive juncture or interface is desired.
Claims12
A soft, conformable, electrically conductive composition comprising:
- (a) a soft polymeric binder forming a coherent matrix and having a Shore A hardness of less than about 40,
- (b) a plurality of insoluble, deformable, generally non-reactive and non-conductive, tacky, spherical domains having Shore A hardness less than about 40 consisting of elastic copolymer of at least one monomer selected from the group consisting of substantially oil-insoluble, water-soluble ionic monomers and maleic anhydride and at least one alkyl acrylate monomer which, as a homopolymer, has T.sub.g below about -20.degree. C. dispersed in said binder in an amount of from about 15 to 60 percent by volume of said composition;
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- (c) an electrically conductive filler dispersed in said binder interjacent said domains in an amount effective to provide at least one electrically conductive pathway through said composition.
A soft, conformable, conductive, pressure-sensitive adhesive composition comprising:
- (a) a soft polymeric pressure-sensitive adhesive binder forming a coherent matrix, said binder selected from the group consisting of acrylate copolymer, tackified polybutylene, tackified rubber resin and vinyl ester;
- (b) from about 15 to 60 percent, based on the volume of the total composition, being insoluble, deformable, generally non-reactive, and non-conductive, tacky spherical domains having Shore A hardness less than about 40 and a diameter from about 6 to 80 microns randomly dispersed in said adhesive binder, said domains consisting of about 90-99.5 percent by weight of at least one alkyl acrylate ester which as a homopolymer has T.sub.g below about -20.degree. C. and about 10 to about 0.5 percent by weight of at least one monomer of the group consisting of substantially oil-insoluble, water-soluble ionic monomers and maleic anhydride;
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- (c) from about 1 to 60 percent of the total composition by volume being electrically conductive particles having particle size less than 100 microns and less than the diameter of said domains dispersed in said adhesive binder interjacent said domains;
- wherein said particles form electrically conductive pathways through said composition, said domains imparting conformability to said composition.
Dependencies are inferred from the claim text.