Semiconductive shield composition
A wire or cable comprising an insulation layer and a semiconducting shield layer over and in contact with the insulation layer and strippable from the insulation layer, the second semiconducting shield layer made from the composition comprising: (A) 45-52% ethylene vinyl acetate (EVA) comprising 28-45% units derived from vinyl acetate (VA) based on the weight of the EVA; (B) 30-45% carbon black having (1) 80-1 15 milliliters per 100 grams (ml/100 g) DBP absorption value, (2) 30-60 milligrams per gram (mg/g) iodine absorption (I2NO), and (3) 0.3-0.6 grams/milliliter (g/ml) apparent density; (C) 5-20% acrylonitrile butadiene rubber (NBR) comprising 25-55% units derived from acrylonitrile (AN) based on the weight of the NBR; (D) 0.2-2% phenolic antioxidant; and (E) 0.5-2% organic peroxide.
1. A composition consisting of in weight percent based on the weight of the composition:
(A) 45-52% ethylene vinyl acetate (EVA) comprising 31% units derived from vinyl acetate (VA) based on the weight of the EVA;
(B) 34-41% carbon black having
(1) 80-115 milliliters per 100 grams (ml/100 g) DBP absorption value,
(2) 30-60 milligrams per gram (mg/g) iodine absorption (I2NO), and
(3) 0.3-0.6 grams/milliliter (g/ml) apparent density;
(C) 8-19% acrylonitrile butadiene rubber (NBR) comprising 30-50% units derived from acrylonitrile (AN) based on the weight of the NBR;
(D) 0.4-1% phenolic antioxidant of 2,2′-methylenebis(6-tert-butyl-4-methylphenol);
(E) 0.7-1.4% organic peroxide; and
(F) optionally wax.
2. The composition of claim 1 in which the organic peroxide is one or more of a dialkyl peroxide and a diperoxyketal.
3. The composition of claim 1 further comprising one or more filler or additive.
4. A wire or cable comprising an insulation layer and a semiconducting shield layer over and in contact with the insulation layer, the shield layer made from the composition of claim 1 .
5. A wire or cable comprising:
(A) a conductor;
(B) a first semiconducting shield layer over and in contact with the conductor;
(C) an insulation layer over and in contact with the first semiconducting shield layer;
(D) a second semiconducting shield layer over and in contact with the insulation layer, the second semiconducting shield layer made from the composition of claim 1 ;
(E) a wire shield over the second semiconducting shield layer; and
a protective jacket.
6. The wire or cable of claim 4 which the insulation layer comprises a crosslinked polyolefin.
7. The wire or cable of claim 4 which the insulation layer comprises a crosslinked ethylene-propylene-diene monomer rubber.
8. The wire or cable of claim 5 which the insulation layer comprises a crosslinked polyolefin.
9. The wire or cable of claim 5 which the insulation layer comprises a crosslinked ethylene-propylene-diene monomer rubber.
10. The composition of claim 9 wherein the composition has a moving die rheometer value from 5.71 inch-pound to 6.46 inch-pound as measured in accordance with ASTM D 5289 at 182° C. for 12 minutes.
11. The composition of claim 10 wherein the composition has a strip force from 13.8 pounds per half-inch to 19.5 pounds per half-inch.
12. A composition consisting of in weight percent based on the weight of the composition:
(A) 45-52% ethylene vinyl acetate (EVA) comprising 40% units derived from vinyl acetate (VA) based on the weight of the EVA;
(B) 34-41% carbon black having
(1) 80-115 milliliters per 100 grams (ml/100 g) DBP absorption value,
(2) 30-60 milligrams per gram (mg/g) iodine absorption (I2NO), and
(3) 0.3-0.6 grams/milliliter (g/ml) apparent density;
(C) 8-19% acrylonitrile butadiene rubber (NBR) comprising 30-50% units derived from acrylonitrile (AN) based on the weight of the NBR;
(D) 0.4-1% phenolic antioxidant of 2,2′-methylenebis(6-tert-butyl-4-methylphenol); and
(E) 0.7-1.4% organic peroxide; and
(F) optionally wax.
13. The composition of claim 12 wherein the composition has a moving die rheometer value from 4.64 inch-pound to 6.38 inch-pound as measured in accordance with ASTM D 5289 at 182° C. for 12 minutes.
14. The composition of claim 13 wherein the composition has a strip force from 5.4 pounds per half-inch to 6.9 pounds per half-inch.