Strippable semi-conductive insulation shield

1 . A polymeric resin composition which, when cross-linked, is effective to provide an insulation shield for power cable which has strip force of greater than 3 pounds per half inch at 23 degrees Celsius after being stored at 100 degrees Celsius for 2 weeks and an initial strip force of not greater than 24 pounds per half inch at 23 degrees Celsius, the polymeric resin composition comprising:

(a) a copolymer of ethylene and an unsaturated ester selected from the group consisting of vinyl esters, acrylic acid esters, methacrylic acid esters and mixtures thereof;

(b) nano-particles which have been contacted with a swelling agent; and

(c) carbon black

wherein the copolymer, the nano-particles and the carbon black being in amounts which will provide a cross-linked insulation shield with a strip tension of greater than 3 pounds per half inch at 23 degrees Celsius after being stored at 100 degrees Celsius for 2 weeks and an initial strip force of not greater than 24 pounds per half inch at 23 degrees Celsius.

2 . (canceled)

3 . The polymeric resin composition as recited in claim 1 wherein the swelling agent is an onium ion.

4 . (canceled)

5 . A polymeric resin composition which when cross-linked which is effective to provide an insulation shield for power cable which has strip tension of greater than 3 pounds per half inch at 23 degrees Celsius after being stored at 100 degrees Celsius for 2 weeks and an initial strip force of not greater than 24 pounds per half inch at 23 degrees Celsius., the polymeric resin composition comprising:

(a) from 15 to 40 weight percent of a comonomer of ethylene and an unsaturated ester selected from the group consisting of vinyl esters, acrylic acid esters, methacrylic acid esters and mixtures thereof;

(b) at least 1 weight percent of nano-particles which have been contacted with a swelling agent which includes an onium ion; and

(c) from 10 to 50 weight percent of carbon black,

wherein the nano-particles and the carbon black being in amounts which will provide the insulation shield composition when cross-linked with a strip tension of greater than 3 pounds per half inch at 23 degrees Celsius after being stored at 100 degrees Celsius for 2 weeks and an initial strip force of not greater than 24 pounds per half inch at 23 degrees Celsius.

6 . (canceled)

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10 . Power cable comprising:

(a) an electrical conductor;

(b) an insulation layer which surrounds the electrical conductor; and

(c) an insulation shield layer which surrounds and is contiguous with the insulation layer, the insulation shield layer comprising a cross-linked composition made from a blend which comprises

(i) a copolymer of ethylene and an unsaturated ester selected from the group consisting of vinyl esters, acrylic acid esters, methacrylic acid esters and mixtures thereof;

(ii) nano-particles which have been contacted with a swelling agent which includes an onium ion; and

(iii) carbon black,

wherein the copolymer, the nano-particles and the carbon black being in amounts which will provide the insulation shield with a strip tension of greater than 3 pounds per half inch at 23 degrees Celsius after being stored at 100 degrees Celsius for 2 weeks and an initial strip force of not greater than 24 pounds per half inch at 23 degrees Celsius.

11 . (canceled)

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13 . (canceled)

14 . Power cable comprising:

(a) an electrical conductor;

(b) an insulation layer which surrounds the electrical conductor; and

(c) an insulation shield layer which surrounds and is contiguous with the insulation layer, the insulation shield layer comprising a cross-linked composition made from a blend which comprises

(i) from 15 to 40 weight percent of a comonomer of ethylene and an unsaturated ester selected from the group consisting of vinyl esters, acrylic acid esters, methacrylic acid esters and mixtures thereof;

(ii) at least 1 weight percent of nano-particles which have been contacted with a swelling agent which includes an onium ion; and

(iii) from 10 to 50 weight percent of carbon black, wherein the nano-particles and the carbon black being in amounts which will provide the insulation shield with a strip tension of greater than 3 pounds per half inch at 23 degrees Celsius after being stored at 100 degrees Celsius for 2 weeks and an initial strip force of not greater than 24 pounds per half inch at 23 degrees Celsius.

15 . (canceled)

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18 . A polymeric resin composition which, when cross-linked, is effective to provide an insulation shield for power cable, the polymeric resin composition comprising:

(a) from 15 to 40 weight percent of a comonomer of ethylene and an unsaturated ester selected from the group consisting of vinyl esters, acrylic acid esters, methacrylic acid esters and mixtures thereof and less than 5 weight percent nitrile butadiene rubber;

(b) at least 1 weight percent of nano-particles which have been contacted with a swelling agent which includes an onium ion; and

(c) from 10 to 50 weight percent of carbon black.

19 . (canceled)

20 . The polymeric resin composition as recited in claims 1 , 3 , 5 , or 18 wherein the composition further includes a free radical cross-linker.

21 . (canceled)

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26 . Power cable comprising:

(a) an electrical conductor;

(b) an insulation layer which surrounds the electrical conductor; and

(c) an insulation shield layer which surrounds and is contiguous with the insulation layer, the insulation shield layer comprising a cross-linked composition made from a blend which comprises

(i) from 15 to 40 weight percent of a comonomer of ethylene and an unsaturated ester selected from the group consisting of vinyl esters, acrylic acid esters, methacrylic acid esters and mixtures thereof and less than 5 weight percent nitrile butadiene rubber;

(ii) at least 1 weight percent of nano-particles which have been contacted with a swelling agent which includes an onium ion; and

(iii) from 10 to 50 weight percent of carbon black,

wherein the nano-particles and the carbon black being in amounts which will provide the insulation shield with a strip tension of greater than 3 pounds per half inch at 23 degrees Celsius after being stored at 100 degrees Celsius for 2 weeks and an initial strip force of not greater than 24 pounds per half inch at 23 degrees Celsius.

27 . (canceled)

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31 . A method for making an insulation shield for power cable, which shield has strip force of greater than 3 pounds per half inch at 23 degrees Celsius after being stored at 100 degrees Celsius for 2 weeks and an initial strip force of not greater than 24 pounds per half inch at 23 degrees Celsius, the method comprising blending:

(a) a copolymer of ethylene and an unsaturated ester selected from the group consisting of vinyl esters, acrylic acid esters, methacrylic acid esters and mixtures thereof;

(b) nano-particles which have been contacted with a swelling agent; and

(c) carbon black,

wherein the blend having less than 5 weight percent nitrile butadiene rubber and less than 28 percent vinyl acetate and

wherein the comonomer, the nano-particles and the carbon black being in amounts which will provide a cross-linked insulation shield with a strip tension of greater than 3 pounds per half inch at 23 degrees Celsius after being stored at 100 degrees Celsius for 2 weeks and an initial strip force of not greater than 24 pounds per half inch at 23 degrees Celsius.

32 . (canceled)