Power cable compositions for strippable adhesion

Abstract

The present invention is a semiconductive power cable composition made from or containing (a) a mixture of a hightemperature polymer and a soft polymer, and (b) a conductive filler, wherein a semiconductive cable layer prepared from the composition strippably adheres to a second cable layer. The invention also includes a semiconductive cable layer prepared from the semiconductive power cable composition as well as a power cable construction prepared by applying the semiconductive cable layer over a wire or cable.

1 . A semiconductive power cable composition comprising: 
 a. a mixture of a high-temperature polymer and a soft polymer; and    b. a conductive filler,    wherein a semiconductive cable layer prepared from the composition strippably adheres to a second cable layer.    
     
     
         2 . The semiconductive power cable composition of  claim 1 , wherein the semiconductive cable layer having a heat resistance of less than 100% as measured by a Hot Creep test at a testing temperature of 150 degrees Centigrade.  
     
     
         3 . The semiconductive power cable composition of  claim 1  wherein the high-temperature polymer and the soft polymer have different heat resistance.  
     
     
         4 . The semiconductive power cable composition of  claim 1  wherein the high-temperature polymer is selected from the group consisting of polypropylenes, polyesters, nylons, polysulfones, and polyaramides and the soft polymer is selected from the group consisting of polyethylenes, polypropylenes, polyesters, and rubbers.  
     
     
         5 . The semiconductive power cable composition of  claim 4  wherein the high-temperature polymer is a polypropylene and the soft polymer is a polyethylene.  
     
     
         6 . The semiconductive power cable composition of  claim 5  wherein the polyethylene is a copolymer of a polar monomer and a nonpolar monomer.  
     
     
         7 . The semiconductive power cable composition of  claim 1  wherein the conductive filler is selected from the group consisting of carbon blacks, carbon fibers, carbon nanotubes, graphite particles, metals, and metal-coated particles.  
     
     
         8 . The semiconductive power cable composition of  claim 1  wherein the second cable layer being chemically-crosslinked.  
     
     
         9 . The semiconductive power cable composition of  claim 1 , further comprising a curing agent.  
     
     
         10 . The semiconductive power cable composition of  claim 1  further comprising a coupling agent.  
     
     
         11 . The semiconductive power cable composition of  claim 10  wherein the coupling agent reduces the amount of a curing agent required to impart heat resistance to the semiconductive cable layer.  
     
     
         12 . The semiconductive power cable composition of  claim 11  further comprising a curing agent.  
     
     
         13 . The semiconductive power cable composition of  claim 1  wherein the mixture further comprises a compatibilizing polymer.  
     
     
         14 . A semiconductive cable layer prepared from the semiconductive power cable composition of  claim 1 .  
     
     
         15 . A power cable construction prepared by applying the semiconductive cable layer of  claim 14  over a wire or cable.  
     
     
         16 . A process for preparing a semiconductive power cable composition comprising the step of: 
 blending a mixture of a high-temperature polymer, a soft polymer, and a conductive filler,    wherein a semiconductive cable layer prepared from the composition strippably adheres to a second cable layer.    
     
     
         17 . The process of  claim 16 , wherein the mixture further comprises a coupling agent.  
     
     
         18 . A process for preparing a semiconductive power cable composition comprising the steps of: 
 a. reactively-coupling a mixture of a high-temperature polymer, a soft polymer, and a coupling agent, in the presence of a conductive filler, wherein the coupling agent reduces the amount of a curing agent required to impart heat resistance to a semiconductive cable layer prepared from a mixture of the high-temperature polymer, the soft polymer, and the conductive filler in the absence of the coupling agent; and    b. admixing a curing agent,    wherein a semiconductive cable layer prepared from the composition strippably adheres to a second cable layer.    
     
     
         19 . A process for preparing a power cable comprising the steps of: 
 a. extruding a semiconductive power cable composition comprising a mixture of a high-temperature polymer, a soft polymer, and a conductive filler, over a metallic conductor to yield a semiconductive cable layer over the metallic conductor; and    b. extruding a polymer-dielectric insulation over the semiconductive cable layer.    
     
     
         20 . The process for preparing a power cable of  claim 19  further comprising the step of 
 c. extruding a second semiconductive power cable composition over the polymer-dielectric insulation to yield a second semiconductive cable layer.    
     
     
         21 . A process for preparing a power cable comprising the steps of: 
 a. extruding a power cable semiconductive composition comprising a mixture of a high-temperature polymer, a soft polymer, and a conductive filler, over a metallic conductor to yield a semiconductive cable layer over the metallic conductor;    b. extruding a chemically-crosslinkable insulation composition over the semiconductive cable layer;    c. extruding a second semiconductive power cable composition over the polymer-dielectric insulation to yield a second semiconductive cable layer; and    d. crosslinking the chemically-crosslinkable insulation composition to yield a crosslinked, polymer-dielectric insulation.