Insulating material for telephone cords and telephone cords incorporating same

• US 4,656,091 A
• Filed: 01/27/1986
• Issued: 04/07/1987
• Est. Priority Date: 10/31/1984
• Status: Expired due to Term

• Current Assignee: AT&T Teleholdings Incorporated (AT&T, Inc.), Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: AT&T Teleholdings Incorporated (AT&T, Inc.), Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Inventors: Choi, Jae H., Vesperman, William C., Kanotz, William M.
• Primary Examiner(s): KENDELL, LORRAINE
• Application Number:
  US06/822,331
• Time in Patent Office: 435 Days
• Field of Search: 428/379, 428/383, 428/389, 428/390, 428/375, 428/394, 428/110 AR, 428/110 SR, 174/120 SR, 350/96.23, 350/96.30, 350/96.34, 524/474
• US Class Current: 428/383
• CPC Class Codes: H01B 3/44 vinyl resins; acrylic resins silicones H01B3/46
• CPC Class Codes: Y10T 428/294 including metal or compound thereof [excluding glass, ceramic and asbestos]
• CPC Class Codes: Y10T 428/2947 Synthetic resin or polymer in plural coatings, each of different type
• CPC Class Codes: Y10T 428/2958 Metal or metal compound in coating
• CPC Class Codes: Y10T 428/296 Rubber, cellulosic or silicic material in coating

Abstract

A telephone cord employs as an insulator for the conductors therein an extrudable blend of a styrene-ethylenebutylene-styrene copolymer with polypropylene.

Claims

1. A telephone cord comprising a plurality of insulated conductors and an insulating jacket thereover wherein the conductor insulation comprises an extruded blend of a styrene-ethylenebutylene-styrene copolymer with a mixture of low melt index and high melt index polypropylenes.

2. The telephone cord recited in claim 1, wherein the chainlength of the styrene portion of the copolymer exceeds the chainlength of the ethylenebutylene portion and wherein the copolymer comprises >

10 to <

20 weight parts of the blend.

3. The telephone cord recited in claim 2, wherein the low melt index polypropylene comprises from >

10 to <

20 weight parts of the blend and the high melt index polypropylene comprises from >

50 to <

80 weight parts of the blend.

4. The telephone cord recited in claim 3, wherein the melt indices of the polypropylene are 1 and 12.

5. The telephone cord recited in claim 1, wherein said insulation further compises color concentrate, peroxide decomposer, stabilizer and antioxidant.

6. The telephone cord recited in claim 3, wherein said insulation further comprises color concentrate, peroxide decomposer, stabilizer and antioxidant.

7. A telephone cord comprising conductors having an insulating covering thereover, said covering comprising an extruded blend of from >

10 to <

20 weight parts of a styrene-ethylenebutylene-styrene copolymer wherein the length of the styrene chain exceeds the length of the ethylenebutylene chain, >

10 to <

20 weight parts of a low melt index polypropylene and >

50 to <

80 weight parts of a high melt index polypropylene.

8. The telephone cord recited in claim 7, wherein the melt indices of the polypropylene are 1 and 12.

9. The telephone cord recited in claim 7, wherein the insulating material is extruded from a blend consisting essentially of:

11 to 14 weight parts of the copolymer;

12 to 16 weight parts melt index 1 polypropylene; and

65 to 75 weight parts melt index 12 polypropylene.

10. The telephone cord recited in claim 9, wherein:

2.5 to 4.5 weight parts polyethylene color concentrate;

0.1 to 0.15 weight parts epoxy resin;

0.01 to 0.06 weight parts antioxidant;

0.05 to 0.15 weight parts peroxide decomposer;

0.01 to 0.1 weight parts copper type inhibitor; and

0.3 to 0.5 weight parts naphthenic oil are present in said blend.