Power or communications cable with flame retardant polymer layer

1. A wire consisting of an inner conductor core surrounded by a flame retardant layer made of a polymer composition in a continuous process which composition comprises

(A) a polar olefin copolymer,

(B) a silicone-group containing compound, and

(C) an inorganic filler which is neither a hydroxide nor a hydrated compound,

wherein the ratio of the MFR 2 measured under a load of 2.16 kg and at a temperature of 190° C. of component (A) to the MFR 2 measured under a load of 2.16 kg and at a temperature of 190° C. of the composition is higher than 3.5, and the wire has a length of at least 100 m.

2. A wire according to claim 1 wherein the flame retardant layer has a thickness of 0.1 to 4 mm.

3. A wire according to claim 1 which further has an outer skin layer with a maximum thickness of 0.4 mm.

4. A wire according to claim 1 wherein the conductor core area is from 0.1 to 400 mm 2 .

5. A power or communications cable or wire comprising a flame retardant layer made of a polymer composition comprising

(A) a polar olefin copolymer,

(B) a silicone-group containing compound, and

(C) an inorganic filler which is neither a hydroxide nor a hydrated compound,

wherein the ratio of the MFR 2 measured under a load of 2.16 kg and at a temperature of 190° C. of component (A) to the MFR 2 measured under a load of 2.16 kg and at a temperature of 190° C. of the composition is higher than 3.5, the cable or wire further comprising at least one further layer.

6. A power or communications cable or wire according to claim 5 wherein the flame retardant layer is produced in a continuous process and the cable or wire has a length of at least 100 m.

7. A power or communications cable or wire according to claim 5 wherein component (A) is a copolymer or a mixture of copolymers of an olefin with one or more comonomers selected from the group of non-substituted or substituted acrylic acids according to formula (I):

H 2 C═CR—COOH  (I)

wherein R is H or an organic substituent.

8. A power or communications cable or wire according to claim 7 wherein the type of comonomer of component (A) is selected from acrylic acid and methacrylic acid.

9. A power or communications cable or wire according to claim 5 wherein the polymer composition passes the single wire burning test according to EN 60332-1.

10. A power or communications cable or wire according to claim 5 wherein the polymer composition has a maximum processing temperature of 200° C. or below.

11. A power or communications cable or wire according to claim 5 wherein the flame retardant layer has an abrasion resistance of at least 100.

12. A power or communications cable or wire according to claim 5 wherein the thickness of the flame retardant layer is from 0.1 to 4 mm.

13. A power or communications cable or wire according to claim 5 which has been produced by extruding the flame retardant layer with a line speed of at least 20 m/min.

14. A power or communications cable or wire according to claim 5 which has been produced by extruding the flame retardant layer onto with a pressure of 50 to 500 bar.

15. A power or communications cable or wire according to claim 5 wherein the amount of inorganic filler (C) is from 20 to 60 wt.-% of the total polymer composition.

16. A power or communications cable or wire according to claim 5 wherein component (B) is present in the composition in such an amount that the total amount of silicone groups in the composition is from 1 to 20 wt-%.

17. A power or communications cable or wire according to claim 5 wherein silicone-group containing compounds (B) is a silicone fluid and/or a gum and/or an olefin copolymer comprising a silicone-group containing monomer.

18. A power or communications cable or wire according to claim 5 wherein component (A) is present in the polymer composition in an amount of 30 to 70 wt.-%.

19. Process for the production of a power or communications cable or wire comprising the extrusion of a polymer composition which comprises

(A) a polar olefin copolymer,

(B) a silicone-group containing compound, and

(C) an inorganic filler which is neither a hydroxide nor a hydrated compound,

wherein the ratio of the MFR 2 measured under a load of 2.16 kg and at a temperature of 190° C. of component (A) to the MFR 2 measured under a load of 2.16 kg and at a temperature of 190° C. of the composition is higher than 3.5, as a flame retardant layer of the cable or wire, wherein the extrusion is performed at a line speed of at least of 20 m/min.

20. Process according to claim 19 wherein the extrusion is performed with a pressure of 50 to 500 bar.

21. Process according to claim 19 wherein the cable or wire is a conduit or automotive wire consisting of a conductor core and the flame retardant layer, optionally further comprising a skin layer with a maximum thickness of 0.4 mm.

22. Method of producing a polymer composition comprising

(A) a polar olefin copolymer,

(B) a silicone-group containing compound, and

(C) an inorganic filler which is neither a hydroxide nor a hydrated compound,

wherein the ratio of the MFR 2 measured under a load of 2.16 kg and at a temperature of 190° C. of component (A) to the MFR 2 measured under a load of 2.16 kg and at a temperature of 190° C. of the composition is higher than 3.5, for the production of a flame retardant layer of a power or communication cable or wire by extrusion, wherein the extrusion is performed at a line speed of at least of 20 m/min.

23. A method according to claim 22 wherein the extrusion is performed with a pressure of 50 to 500 bar.

24. A method according to claim 22 wherein the cable or wire is a conduit or automotive wire consisting of an conductor core and the flame retardant layer, optionally further comprising a skin layer with a maximum thickness of 0.4 mm.