Filled cables

• US 4,870,117 A
• Filed: 03/03/1988
• Issued: 09/26/1989
• Est. Priority Date: 09/12/1986
• Status: Expired due to Term

• Current Assignee: Fitel USA Corporation
• Original Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Inventors: Levy, Alvin C.
• Primary Examiner(s): Schofer, Joseph L.
• Assistant Examiner(s): Mulcahy, Peter D.
• Application Number:
  US07/166,793
• Time in Patent Office: 572 Days
• Field of Search: 174/23 R, 174/23 C, 523/173
• US Class Current: 523/173
• CPC Class Codes: H01B 3/44 vinyl resins; acrylic resins silicones H01B3/46
• CPC Class Codes: H01B 7/285 by completely or partially filling interstices in the cable
• CPC Class Codes: Y02A 30/14 Extreme weather resilient electric power supply systems, e.g. strengthening power lines or underground power cables

Abstract

A waterproof cable having a filling material for filling voids in the cable which comprises a styrene-rubber diblock copolymer, a styrene-rubber-styrene triblock copolymer a paraffinic oil, a polybutene oil and a polyethylene wax. The cable is suitable for aerial use as well as underground use.

Claims

1. A cable comprising a plurality of conductors contained within a sheath leaving voids between the conductors and/or between the conductors and the sheath and a filling material filling said voids, the invention characterized in that said filing material comprises a mixture of a styrene-rubber diblock copolymer, wherein the styrene block comprises a styrene homopolymer, wherein the rubber block comprises a saturated olefin copolymer and wherein said styrene-rubber diblock copolymer has a styrene/rubber ratio of from about 0.2 to 0.5, a compatible oil and polyethylene in proportions to give a cable filling material having a viscosity which facilitates ease in cable filling and being such that the cable has a mutual capacitance stability of no greater than 5% increase in capacitance.

4. The cable recited in claim 1, wherein said styrene-rubber diblock copolymer is a styrene-ethylene butylene diblock copolymer.

12. The cable of claim 1, wherein said mixture includes at least one additive selection from the group consisting of a styrene-rubber styrene triblock copolymer having a styrene/rubber ratio of about 0.2 to 0.5 and a polybutene oil having an average molecular weight of from about 300 to 2,000.

13. The cable of claim 1, wherein said filling material also includes a styrene-rubber-styrene triblock copolymer such that the ratio by weight percent of the diblock copolymer to the triblock copolymer is in the range from about 0.5 to about 5.

14. The cable of claim 13, wherein said filling material also includes from about 4-12% polyethylene having a softening point to from 105°

C. to 130°

C. and wherein said oil is a mixture comprising a polybutene oil and a paraffinic based processing oil type 104B per ASTM D 2226.

15. The cable of claim 14, wherein said paraffinic oil of said mixture has a SUS viscosity at 210°

F. to 40, and the cable filling material has a minimum flow temperature of about 80°

C.

2. A cable comprising a plurality of conductors contained within a sheath leaving voids between the conductors and/or between the conductors and the sheath and a filling material filling said voids, the invention characterized in that said filling material comprises a mixture of a styrene-rubber diblock copolymer, a compatible oil and polyethylene in proportions to provide a cable filling material having a viscosity which facilitates ease in cable filling and being such that the cable has a mutual capacitance stability of no greater then 5% increase in capacitance, and wherein the styrene-rubber diblock copolymer has a styrene-rubber ratio of from about 0.2 to 0. 5 and the oil is at least one oil selected from those oils falling within ASTM D2226, types 103, 104A and 104B.

3. The cable recited in claim 2, wherein said oil is selected from the group consisting of naphthenic oils, paraffinic oils and mixtures thereof and wherein the cable filling material has a minimum flow temperature of about 80°

C.

5. The cable recited in claim 5, wherein:

said oil has a minimum specific gravity of about 0.85, a minimum SUS viscosity of 210°

F. of about 40, and a maximum pour point of about 20°

F.; and

said polyethylene has a softening point of from 105°

C. to 130°

C.

6. A cable comprising a plurality of insulated strands contained within a sheath leaving voids between said strands and/or between said strands and said sheath and a filling material filling said voids, the invention characterized in that said filling material comprises a mixture of:

a styrene-rubber diblock copolymer having a styrene/rubber ratio of from about 0.2 to 0.5 wherein the styrene block of said diblock copolymer comprises a styrene homopolymer and wherein the rubber block of said diblock copolymer comprises a saturated olefin copolymer;

a styrene-rubber-styrene triblock copolymer having a styrene/rubber ratio of from about 0.2 to 0.5 wherein the ratio by weight percent of the diblock copolymer to the triblock copolymer is in the range of from about 0.5 to about 5;

a compatible oil; and

from about 4-12% polyethylene having a softening point of from 105°

C. to 130°

C., said cable filling material having a flow temperature of at least 80°

C., and said cable having a mutual capacitance stabiltiy of no more than 5% increase in capacitance and wherein the filling material is of a viscosity of less than about 60 centipoises at the filling tempeture.

7. The cable recited in claim 6, and having a composition within the ranges as set forth within the boundaries A, B, C, and D of the FIGURE.

8. The cable recited in claim 6, wherein the diblock copolymer is a styrene-ethylene butylene copolymer.

9. The cable recited in claim 7, wherein the rubber block of the said block copolymers is an ethylene butylene block.

10. The cable recited in claim 9, having a composition which falls within the boundaries of A, B, C and D of the FIGURE.

16. The cable of claim 7, wherein said oil of said filling material is a mixture comprising a polybutene oil and a paraffinic oil type 104B per ASTM D 2226 having a SUS viscosity at 210°

F. of 40.

11. A cable comprising a plurality of insulated strands contained within a sheath leaving voids between said strands and/or between said strands and said sheath and a filling material filling said voids, the invention characterized in that said filling material comprises a mixture of:

a styrene-rubber diblock copolymer having a styrene-rubber ration of from about 0.2 to about 0.5 wherein he styrene block of said diblock copolymer comprises a styrene homopolymer and the rubber block of said diblock copolymer comprises a saturated olefin copolymer;

a paraffinic oil falling within the class defined by ASTM D2226 type 104B and having an SUS viscosity at 210°

F. of 40,;

from about 4-12% polyethylene having a softening point of from 105°

C. to 130°

C.;

a styrene-rubber-styrene triblock copolymer having a styrene/rubber ratio of from about 0.2 to 0.5, the ratio by weight of diblock copolymer to triblock copolymer being in the range of about 0.05 to about 0.05 to about 5; and

a polybutene oil having an average molecular weight of from about 300, to 2,000, said cable having a mutual capacitance stability of no more than 5% increase in capacitance and wherein the filling material is of a viscosity of less than about 60 centipoise at the filling temperature.