Process for producing electroconductive films

Claim 2

A process for producing an electroconductive film having a volume resistivity in a fiber oriented direction of not more than 1×10 8 ohm cm which comprises the steps of forming a wet web by papermaking, with a papermaking machine, from a paper stock obtained by mixing from 94.5% to 40% by volume of a thermoplastic synthetic pulp of a single thermoplastic synthetic resin with from 5% to 30% by volume of thermoplastic composite fibers comprising a first component having a lower melting point than that of said thermoplastic synthetic pulp and a second component having a higher melting point than that of said thermoplastic synthetic pulp, and from 0.5% to 30% by volume of electroconductive fibers; then heating and drying said wet web at a temperature of not less than the melting point of said first component and below the melting point of said thermoplastic synthetic pulp to melt the first component, thereby forming a base paper wherein the paper stock components are adhered to each other; and thereafter heating said base paper under pressure at a temperature of not less than the melting point of said thermoplastic synthetic pulp and below the melting point of said second component to melt the thermoplastic synthetic pulp, thereby forming a film having dispersed said second component and said electroconductive fibers therein.

Claim 3

The process according to claim 1 wherein the film having dispersed the second component and the electroconductive fibers therein has an opacity of not more than 30%.

Claim 4

The process according to claim 1 wherein the basis weight of the film having dispersed the second component and the electroconductive fibers therein is not more than 70 grams per square meter.

Claim 5

The process according to claim 1 wherein the electroconductive fibers are carbon fibers.

Claim 6

The process according to claim 1 wherein the electroconductive fibers are metallic fibers.

Claim 7

The process according to claim 1 wherein the electroconductive fibers are metal-coated fibers.

Claim 8

The process according to claim 5 wherein the metallic fibers are stainless steel fibers.

Claim 9

The process according to claim 6 wherein the metal-coated fibers are nickel-coated carbon fibers.

Claim 10

The process according to claim 1 wherein the thermoplastic composite fibers are composite fibers having a concentric structure wherein the second component is a core and the first component is a clad.

Claim 11

The process according to claim 1 wherein the themoplastic composite fibers are composite fibers having an eccentric structure wherein the second component is a core and the first component is a clad.

Claim 12

The process according to claim 1 wherein a paper pulp is incorporated into the paper stock.

Claim 13

An electroconductive film having a volume resistivity of fiber oriented direction of not more than 1×10 8 ohm cm, wherein electroconductive fibers and a non-melted second component of thermoplastic composite fibers are dispersed in a thermoplastic synthetic resin matrix formed from a thermoplastic synthetic pulp, and wherein said electroconductive fibers and said second component of thermoplastic composite fibers are adhered to each other by a first component of said thermoplastic composite fibers, produced by the process comprising the steps of forming a wet web by papermaking, with a papermaking machine, from a paper stock obtained by mixing from 94.5% to 40% by volume of a thermoplastic synthetic pulp of a single thermoplastic synthetic resin with from 5% to 30% by volume of thermoplastic composite fibers comprising a first component having a lower melting point than that of said thermoplastic synthetic pulp and a second component having a higher melting point than that of said thermoplastic synthetic pulp, and from 0.5% to 30% by volume of electroconductive fibers; then heating and drying said wet web at a temperature of not less than the melting point of said first component and below the melting point of said thermoplastic synthetic pulp to melt the first component, thereby forming a base paper wherein the paper stock components are adhered to each other; and thereafter heating said base paper under pressure at a temperature of not less than the melting point of said thermoplastic synthetic pulp and below the melting point of said second component to melt the thermoplastic synthetic pulp, thereby forming a film having dispersed said second component and said electroconductive fibers therein.

Claim 14

An electroconductive film having a volume resistivity of fiber oriented direction of not more than 1×10 8 ohm cm, wherein electroconductive fibers and a non-melted second component of thermoplastic composite fibers are dispersed in a thermoplastic synthetic resin matrix formed from a thermoplastic synthetic pulp, and wherein said electroconductive fibers and said second component of thermoplastic composite fibers are adhered to each other by a first component of said thermoplastic composite fibers, produced by the process comprising the steps of forming a wet web by papermaking, with a papermaking machine, from a paper stock obtained by mixing from 94.5% to 40% by volume of a thermoplastic synthetic pulp of a single thermoplastic synthetic resin with from 5% to 30% by volume of thermoplastic composite fibers comprising a first component having a lower melting point than that of said thermoplastic synthetic pulp and a second component having a higher melting point than that of said thermoplastic synthetic pulp, and from 0.5% to 30% by volume of electroconductive fibers; then heating and drying said wet web at a temperature of not less than the melting point of said first component and below the melting point of said thermoplastic synthetic pulp to melt the first component, thereby forming a base paper wherein the paper stock components are adhered to each other; and thereafter heating said base paper under pressure at a temperature of not less than the melting point of said thermoplastic synthetic pulp and below the melting point of said second component to melt the thermoplastic synthetic pulp, thereby forming a film having dispersed said second component and said electroconductive fibers therein.