Composite of non-polar organic polymer, polar organic polymer, and ultra-low-wettability carbon black
A semiconductive composite material comprising a non-polar organic polymer, a polar organic copolymer, and an electrical conducting effective amount of an ultra-low-wettability carbon black. Also a method of making the composite material; a crosslinked polyethylene product made by curing the composite material; manufactured articles comprising a shaped form of the inventive composite material or product; and methods of using the inventive composite material, product, or articles.
1. A semiconductive composite material comprising (A) a non-polar polyolefin polymer in a first phase, (AA) a polar ethylene-based copolymer in a second phase, which is at least partially immiscible in the first phase, and an electrical conducting effective amount of (B) a carbon black (CB), which has a Brunauer-Emmett-Teller (BET) nitrogen surface area of from 35 to 190 square meters per gram (m 2 /g), measured by BET Nitrogen Surface Area Test Method; and an oil absorption number (OAN) from 115 to 180 milliliters of oil per 100 grams (mL/100 g), measured by Oil Absorption Number Test Method; and a water uptake of from 400 to 2400 parts per million (ppm, weight), as measured by a Moisture Uptake Test Method performed by drying a carbon black sample in a vacuum oven at 100° C. overnight, measuring the weight of the dried carbon black sample, placing the dried carbon black sample inside a chamber with well-controlled 80% relative humidity (RH) and a temperature of 24° C. for 24 hours to give a humidified carbon black sample, weighing the humidified carbon black sample, and calculating the amount of moisture uptake in weight parts per million using the following equation: amount moisture uptake=(weight of humidified carbon black sample−weight of dried carbon black sample) divided by weight of dried carbon black sample.
2. The semiconductive composite material of claim 1 wherein the (B) CB is characterized by any one of limitations (i) to (iii): (i) the (B) CB has a BET nitrogen surface area from 40 to 63 m 2 /g, measured by the BET Nitrogen Surface Area Test Method; and an OAN from 120 to 150 mL/100 g, measured by the Oil Absorption Number Test Method; (ii) the (B) CB has a BET nitrogen surface area from 120 to 180 m 2 /g, measured by the BET Nitrogen Surface Area Test Method; and an OAN from 150 to 175 mL/100 g, measured by the Oil Absorption Number Test Method; and (iii) the (B) CB is a blend of the CBs of (i) and (ii).
3. A semiconductive composite material comprising (A) a non-polar polyolefin polymer in a first phase, (AA) a polar ethylene-based copolymer in a second phase, which is at least partially immiscible in the first phase, and an electrical conducting effective amount of (B) a carbon black (CB), which has a surface wettability profile characterized by wettability≤0.0101 at surface coverage of 0.02, and wettability≤0.0101 at surface coverage of 0.04, and wettability≤0.0099 at surface coverage of 0.06, and wettability≤0.0111 at surface coverage of 0.08, and wettability≤0.0113 at surface coverage of 0.10, measured by inverse gas chromatography (IGC) according to Wettability Test Method; and a water uptake of from 400 to 2400 parts per million (ppm, weight), as measured by a Moisture Uptake Test Method performed by drying a carbon black sample in a vacuum oven at 100° C. overnight, measuring the weight of the dried carbon black sample, placing the dried carbon black sample inside a chamber with well-controlled 80% relative humidity (RH) and a temperature of 24° C. for 24 hours to give a humidified carbon black sample, weighing the humidified carbon black sample, and calculating the amount of moisture uptake in weight parts per million using the following equation: amount moisture uptake=(weight of humidified carbon black sample-weight of dried carbon black sample) divided by weight of dried carbon black sample.
4. The semiconductive composite material of claim 1 wherein the (B) CB is characterized by any one of limitations (i) to (iii): (i) a BET nitrogen surface area from 40 to 180 m 2 /g, measured by the BET Nitrogen Surface Area Test Method; (ii) a surface wettability profile characterized by wettability≤0.0058 at surface coverage of 0.02, and wettability≤0.0070 at surface coverage of 0.04, and wettability≤0.0075 at surface coverage of 0.06, and wettability≤0.0086 at surface coverage of 0.08, and wettability≤0.0091 at surface coverage of 0.10, measured by IGC according to the Wettability Test Method; and (iii) both (i) and (ii).
5. The semiconductive composite material of claim 1 that is free of any carbon black other than the carbon black.
6. The semiconductive composite material of claim 1 characterized by any one of limitations (i) to (v): (i) comprising from 61.0 to 99.0 wt % of a combination of the (A) non-polar polyolefin polymer and the (AA) polar ethylene-based polymer; and from 39.0 to 1.0 wt % of the (B) CB, based on total weight of the semiconductive composite material; wherein the combination of (A) and (AA) has from 5 to 95 wt % of (A) and from 95 to 5 wt % of (AA) based on the combined weight of (A) and (AA); (ii) the (A) non-polar polyolefin polymer is a non-polar ethylene-based polymer; (iii) both (i) and (ii); (iv) the (A) non-polar polyolefin polymer is a non-polar propylene-based polymer; and (v) both (i) and (iv).
7. The semiconductive composite material of claim 1 , further comprising at least one additive chosen from: (C) a plastomer; (D) an antioxidant; (E) an organic peroxide; (F) a scorch retardant; (G) an alkenyl-functional coagent; (H) a nucleating agent; (I) a processing aid; (J) an extender oil; (K) a stabilizer.
8. The semiconductive composite material of claim 1 , characterized by a log (volume resistivity), measured by Volume Resistivity Test Method, of <3.0 log (Ohm-centimeter (Ohm-cm)) at an electrical conducting effective amount of 10.0 wt %, or <4.0 log (Ohm-cm) at an electrical conducting effective amount of 7 wt %, or <10.0 log (Ohm-cm) at an electrical conducting effective amount of 5 wt %, or <15.5 log (Ohm-cm) at the electrical conducting effective amount of 2.0 wt %, wherein electrical conducting effective amount of the (B) 64-W-CB is based on total weight of the semiconductive composite material.
9. The semiconductive composite material of claim 1 characterized by a log (volume resistivity) of ≤10 Log (Ohm-cm) at total BET N2 surface area of carbon black in composite of 5.0 to 10.0 m 2 /g; or ≤12 Log (Ohm-cm) at total BET N2 surface area of carbon black in composite of 2.0 to 5.0 m 2 /g; or ≤15 Log (Ohm-cm) at total BET N2 surface area of carbon black in composite of 0.5 to 2.0 m 2 /g.
10. A method of making the semiconductive composite material of claim 1 , the method comprising mixing the (B) carbon black (CB) into a melt of the (A) non-polar polyolefin polymer and (AA) polar ethylene-based copolymer to give the semiconductive composite material as a melt blend comprising constituents (A), (AA), and (B).
11. A crosslinked polyethylene product that is a product of curing the semiconductive composite material of claim 1 .
12. A manufactured article comprising a shaped form of the semiconductive composite material of claim 1 .
13. An electrical conductor device comprising a conductive core and a semiconductive layer at least partially covering the conductive core, wherein at least a portion of the semiconductive layer comprises the semiconductive composite material of claim 1 .
14. A method of conducting electricity, the method comprising applying a voltage across the conductive core of the electrical conductor device of claim 13 so as to generate a flow of electricity through the conductive core.
15. A thermally cycled semiconductive composite material made by subjecting the semiconductive composite material of claim 1 to a thermal cycle comprising heating the semiconductive composite material to from 170° to 190° C. for 1 to 5 minutes, and then cooling to 30° C. to give a cooled, thermally cycled semiconductive composite material.