Water swellable semi-conductive tape
A water swellable semi-conductive material having a semi-conductive layer and a semi-conductive water swellable polymeric layer which is positioned on opposing surfaces of the semi-conductive layer is provided. The semi-conductive water swellable polymeric layer is composed of conductive particles dispersed within a crosslinked superabsorbent polymeric matrix.
1 . A water swellable semi-conductive material comprising:
a substrate;
first and second semi-conductive layers positioned on opposing surfaces of the substrate; and
a semi-conductive water swellable polymeric layer positioned on an outer surface of one of the first or second semi-conductive layers, the semi-conductive water swellable polymeric layer comprising conductive particles dispersed within a crosslinked superabsorbent polymeric matrix, wherein the conductive particles comprise carbon black particles having a particle mesh of about 0.06 mm to about 0.25 mm.
2 . The water swellable semi-conductive material according to claim 1 , wherein the crosslinked superabsorbent polymeric matrix comprises a cross-linked acrylate polymer.
3 . The water swellable semi-conductive material according to claim 1 , wherein the superabsorbent polymeric matrix comprises a cross-linked acrylate polymer matrix and wherein the carbon black particles are dispersed within the cross-linked acrylate polymer matrix to form a conductive pathway within the cross-linked acrylate polymer matrix.
4 . The water swellable semi-conductive material according to claim 1 , wherein the superabsorbent polymeric matrix is a coating positioned on top of the first or second semi-conductive layer.
5 . The water swellable semi-conductive material according to claim 1 , wherein the semi-conductive water swellable polymeric layer is formed from application of an aqueous composition comprising an acrylate polymer or acrylate pre-polymer and the conductive particles to the first or second semi-conductive layer, followed by drying the aqueous composition to form the superabsorbent polymeric matrix having conductive particles dispersed therein.
6 . The water swellable semi-conductive material according to claim 5 , wherein the conductive particles are present in the aqueous composition in an amount from 5 percent by weight to 50 percent by weight.
7 . The water swellable semi-conductive material according to claim 5 , wherein the conductive particles are present in the aqueous composition in an amount of about 25 percent by weight.
8 . The water swellable semi-conductive material according to claim 1 , wherein the first and second semi-conductive layers comprise carbon black particles.
9 . The water swellable semi-conductive material according to claim 1 , wherein the first and second semi-conductive layers comprise carbon black particles having a particle size of about 150 μm to about 400 μm.
10 . The water swellable semi-conductive material according to claim 1 , wherein the substrate is impregnated with super conductive particles to form the first and second semi-conductive layers positioned on opposing surfaces of the substrate.
11 . The water swellable semi-conductive material according to claim 1 , wherein the water swellable semi-conductive material is a multi-layer tape, the multi-layer tape comprising:
a first layer comprising the substrate and the first and second semi-conductive layers, wherein the substrate is an elongated material, the elongated material having first and second opposing surfaces, and the first and second semi-conductive layers are positioned on the first and second opposing surfaces of the substrate; and
a second layer comprising the semi-conductive water swellable polymeric layer, wherein the second layer is positioned on one of the first or second semi-conductive layers.
12 . The water swellable semi-conductive material according to claim 11 , wherein the elongated material is a woven fabric.
13 . The water swellable semi-conductive material according to claim 11 , wherein the elongated material is a polymeric material.
14 . The water swellable semi-conductive material of claim 1 , wherein a thickness of the water swellable semi-conductive material is less than about 0.40 mm.
15 . The water swellable semi-conductive material of claim 1 , wherein a thickness of the water swellable semi-conductive material is less than about 0.15 mm.
16 . A water-resistant cable, comprising:
a conductor; and
a water swellable semi-conductive material placed in connection with the conductor, the water swellable semi-conductive material comprising:
a substrate having first and second opposing faces;
first and second semi-conductive coatings positioned on opposing faces of the woven substrate; and
a semi-conductive water swellable polymeric layer positioned on an outer surface of one of the first or second semi-conductive coatings, the semi-conductive water swellable polymeric layer comprising conductive particles dispersed within a superabsorbent polymeric matrix, wherein the conductive particles comprise carbon black particles having a particle mesh of about 0.06 mm to about 0.25 mm.
17 . The water-resistant cable according to claim 16 , wherein the conductor is an electrical conductor.
18 . The water-resistant cable according to claim 16 , wherein the conductor is an electrical cable, and the water swellable semi-conductive material is in the form of a tape applied to the electrical cable.
19 . A method of making a water swellable semi-conductive material, the method comprising:
providing a substrate;
applying a semi-conductive coating to the substrate to form a semi-conductive substrate;
applying an aqueous composition comprising an acrylate polymer or acrylate pre-polymer and conductive particles to the semi-conductive substrate; and
drying the aqueous composition on the semi-conductive substrate and cross-linking the acrylate polymer or acrylate pre-polymer to form a semi-conductive water swellable polymeric layer positioned on the semi-conductive substrate, wherein the semi-conductive water swellable polymeric layer is comprised of a crosslinked superabsorbent polymer matrix having conductive particles dispersed therein, wherein the conductive particles comprise carbon black particles having a particle mesh of about 0.06 mm to about 0.25 mm.
20 . The method according to claim 19 , wherein the semi-conductive coating is applied to opposing surfaces of the substrate as a coating.
21 . The method according to claim 19 , wherein the semi-conductive coating is impregnated within the substrate.
22 . The method of claim 19 , wherein the aqueous composition is applied to one side of the substrate.
23 . The method of claim 19 , wherein the aqueous composition is applied to both sides of the substrate.
24 . The method of claim 19 , wherein the aqueous composition comprises separate components that are mixed together prior to application.