Conductive compositions

Claim 2

A composition comprising an organic resin binder and electrically-conductive powder filler wherein said powder is a copper powder cleaned in a metal-complexing cleaning bath and thereupon plated with a silver coating in a plating solution and finally heat treated for a period of time effective to enhance its heat-aging stability when loaded into an organic polymer resin matrix.

Claim 3

A composition comprising a sufficient conductive metal powder that is in particle-to-particle contact with a resin matrix when said matrix is in, or converted into, a solid monolithic state and wherein said conductive powder is a powder of silver-plated copper which has been heat treated for a period of over 24 hours which time is effective to impart improved aging resistance to said composition in its said monolithic state, said powder having an average particle dimension of less than 0.025 inch.

Claim 4

A composition comprising a sufficient conductive metal powder that is in particle-to-particle contact with a resin matrix when said matrix is in, or converted into, a solid monolithic state and wherein said conductive powder is a powder of silver-plated copper which has been heat treated for a period of over 24 hours which time is effective to impart improved aging resistance to said composition in its said monolithic state, said powder having an average particle dimension of less than 0.025 inch.

Claim 5

A composition as defined in claims 1 or 2 wherein said resin is silicone.

Claim 6

A composition as defined in claims 1 or 2 wherein said powder is formed of a silver-plated, substantially-pure copper powder.

Claim 7

A composition as defined in claims 1 or 2 wherein said powder has been heat treated after being plated, at a temperature of from about 130° C. to 210° C. for a period of time greater than 24 hours and has an average particle size below 0.010 inch in average dimension.

Claim 8

A composition as described in claims 1 or 2 wherein said heat-aging stability of said composition is manifested by the characteristic of maintaining a volume resistivity of less than 2 ohm-cm after being subjected to an age test at 195° C. for 500 hours in the Standard Test.

Claim 9

A composition as defined in claim 6 wherein said volume resistivity is maintainable for 1000 hours in a Standard Test.

Claim 10

A composition as defined in claims 1 or 2 wherein said copper powder, after said plating, is aged at a temperature of at least 130° C. to about 210° C. for a period of time greater than 24 hours and wherein said composition has a volume resistivity of less than 2 ohm-cm after being subjected to an age test at 150° C. for a minimum of 500 hours in a Standard Test.

Claim 11

A composition as defined in claims 1 or 2 wherein said heat aging stability of said composition is manifested by an increase in volume resistivity of less than a factor of 100 in the first 100 hours at 195° C. in the Standard Test.

Claim 12

A composition as defined in claim 8 wherein said heat aging stability of said composition is characterized by an increase in volume resistivity of less than a factor of 100 in the first 100 hours at 195° C. in the Standard Test.

Claim 13

A composition as defined in claims 1 or 2 wherein said powder has a core and a silver coating derived from silver ion of a salt selected from cyanide and silver nitrate and wherein said composition has a resistivity increase of less than 2 ohm-cm after being subjected to an age test of 195° C. for 500 hours in said Standard Test.

Claim 14

A composition comprising (a) a conductive powder formed of a copper core with a continuous, thin, adherent silver coating thereover said powder being characterized by a heat-aging stability which is manifested by the characteristic of the Standard Test, whereby said powder in particle-to-particle contact, within test composition provides means to maintain a volume resistivity of less than 2 ohm-cm in said Test matrix after being subjected to an age test at 195° C. for 500 hours and (b) an organic resin matrix, said powder being present in a quantity effective to impart electroconductivity to said composition when said composition is in, or converted into, a solid monolithic state whereby said powder is in electroconductive particle-to-particle contact within a matrix formed of said organic resin.

Claim 15

A composition comprising (a) a conductive powder formed of a copper core with a continuous, thin, adherent silver coating thereover said powder being characterized by a heat-aging stability which is manifested by the characteristic of the Standard Test, whereby said powder in particle-to-particle contact, within test composition provides means to maintain a volume resistivity of less than 2 ohm-cm in said Test matrix after being subjected to an age test at 195° C. for 500 hours and (b) an organic resin matrix, said powder being present in a quantity effective to impart electroconductivity to said composition when said composition is in, or converted into, a solid monolithic state whereby said powder is in electroconductive particle-to-particle contact within a matrix formed of said organic resin.

Claim 16

A composition as defined in claim 12 wherein said volume resistivity can be maintained for 1000 hours at 195° C. in said Standard Test and comprising an organic resin matrix, said powder being present in a quantity effective to impart electroconductivity to said composition when said composition is in, or converted into, a solid monolithic state whereby said powder is in electroconductive particle-to-particle contact within a matrix formed of said organic resin.

Claim 17

A composition as defined in claim 12 wherein said copper core is substantially pure copper and said copper powder has an average particle diameter of below 0.025 inch and comprising an organic resin matrix said powder being present in a quantity effective to impart electroconductivity to said composition when said composition is in, or converted into, a solid monolithic state whereby said powder is in electroconductive particle-to-particle contact within a matrix formed of said organic resin.

Claim 18

A composition as defined in claim 12 wherein said conductive powder has an average particle diameter of 0.010 inch and comprising an organic resin matrix, said powder being present in a quantity effective to impart electroconductivity to said composition when said composition is in, or converted into, a solid monolithic state whereby said powder is in electroconductive particle-to-particle contact within a matrix formed of said organic resin.

Claim 19

A composition as defined in claim 12 wherein said conductive powder has heat-aging stability manifested by a characteristic of said powder maintaining a volume resistivity of less than 2 ohm-cm when loaded into the Standard Test in particle-to-particle contact and being subjected to an age test at 195° C. for 500 hours and comprising an organic resin matrix, said powder being present in a quantity effective to impart electroconductivity to said composition when said composition is in, or converted into, a solid monolithic state whereby said powder is in electroconductive particle-to-particle contact within a matrix formed of said organic resin.

Claim 20

A composition as defined in claim 12 wherein said conductive powder having a heat-aging stability when loaded in particle-to-particle contact and subjected to said Standard Test, manifested by an increase in volume resistivity of a factor of 100 times in 500 hours at 195° C. and an organic resin matrix, said powder being present in a quantity effective to impart electroconductivity to said composition when said composition is in, or converted into, a solid monolithic state whereby said powder is in electroconductive particle-to-particle contact within a matrix formed of said organic resin.

Claim 21

A composition as defined in claim 17 wherein said conductive powder having a heat-aging stability when loaded in particle-to-particle contact and subjected to said Standard Test, manifested by an increase in volume resistivity of less than 100% in 500 hours at 195° C. and an organic resin matrix, said powder being present in a quantity effective to impart electroconductivity to said composition when said composition is in, or converted into, a solid monolithic state whereby said powder is in electroconductive particle-to-particle contact within a matrix formed of said organic resin.

Claim 22

A composition as defined in claim 12 wherein said powder comprises from about 0.5 to at least 4 troy ounces of silver per pound of copper and an organic resin matrix, said powder being present in a quantity effective to impart electroconductivity to said composition when said composition is in, or converted into, a solid monolithic state whereby said powder is in electroconductive particle-to-particle contact within a matrix formed of said organic resin.

Claim 23

A composition as defined in claim 15 wherein said conductive powder comprises from about 0.5 to 4 troy ounces of silver per pound of copper and comprising an organic resin matrix, said powder being present in a quantity effective to impart electroconductivity to said composition when said composition is in, or converted into, a solid monolithic state whereby said powder is in electroconductive particle-to-particle contact within a matrix formed of said organic resin.

Claim 24

A composition as defined in claim 12 wherein said resin is an epoxy resin.

Claim 25

A composition as defined in claim 12 wherein said resin is a silicone resin.

Claim 26

A composition as defined in claim 12 wherein said resin comprises vinyl polymer.

Claim 27

A composition as defined in claim 12 wherein said resin comprises a pre-polymerized polyurethane.

Claim 28

A composition as defined in claim 12 wherein said resin comprises a vinyl polymer.

Claim 29

A composition as defined in claim 12 wherein said composition, when aged in solid monolithic form at 195° C. for 500 hours, maintains a volume resistivity of less than 2 ohm-cm.

Claim 30

A composition as defined in claim 12 wherein said composition, when itself is aged in solid monolithic form at 195° C. for 500 hours evidences an increase in volume resistivity of less than a factor of 10 times in 500 hours.

Claim 31

A composition as defined in claim 12 wherein said composition, when itself is aged in solid monolithic form at 195° C. for 500 hours evidences an increase in volume resistivity of less than 100% in 500 hours.

Claim 32

An electroconductive composition comprising a conductive powder of silver-coated non-noble metal and an organic-resin matrix in which said powder is present in particle-to-particle contact, said composition having the property of increasing in volume resistivity by less than 100 times to a value of less than 100 ohms when it is heated at 195° C. for 500 hours.

Claim 33

An electroconductive composition comprising a conductive powder of silver-coated non-noble metal and an organic-resin matrix in which said powder is present in particle-to-particle contact, said composition having the property of increasing in volume resistivity by less than 100 times to a value of less than 100 ohms when it is heated at 195° C. for 500 hours.

Claim 34

An electromagnetic-energy shielding gasket formed of the composition of claim 28 and having a definitive formstable shape, having a hardness value of less than 95 (Shore A).

Claim 35

A gasket made of a composition as defined in claim 29 wherein said matrix is a silicone resin matrix.

Claim 36

A gasket as defined in claim 30 wherein said matrix is a silicone resin matrix.

Claim 37

A composition as defined in claims 13, 16, 18 or 19 wherein said organic resin matrix is a silicone resin matrix.

Claim 38

A composition as defined in claims 12, 13, 16, 18, 19 or 22 wherein said conductive powder has been heat treated at a temperature of at least about 130° C. to enhance conductivity stability on aging.

Claim 39

A composition as in claim 29 wherein said non-noble metal is copper.

Claim 40

A gasket as defined in claim 31 wherein said powder is a silver-coated copper powder.

Claim 41

A composition as defined in claim 29 wherein said powder is silver-coated copper powder.