Elastomeric pre-stretched tubes for providing electrical stress control

• US 4,363,842 A
• Filed: 03/02/1981
• Issued: 12/14/1982
• Est. Priority Date: 03/02/1981
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Nelson, Paul N.
• Primary Examiner(s): Thibodeau, Paul J.
• Application Number:
  US06/239,538
• Time in Patent Office: 652 Days
• Field of Search: 428/36, 428/222, 428/323, 428/324, 428/328, 428/913, 156/86, 174/DIG. 8, 174/68 A, 174/73 R, 138/115, 138/119, 138/DIG. 5
• US Class Current: 428/35.8
• CPC Class Codes: B29C 61/003 characterised by the choice of material
• CPC Class Codes: B29C 61/065 Preforms held in a stressed condition by means of a removable support; Supports therefor
• CPC Class Codes: B29C 70/882 partly or totally electrically conductive, e.g. for EMI shielding conductive floors or floor coverings H05F3/025; EMI shielding in general H05K9/00
• CPC Class Codes: B29K 2023/16 EPM, i.e. ethylene-propylene copolymers; EPDM, i.e. ethylene-propylene-diene copolymers; EPT, i.e. ethylene-propylene terpolymers
• CPC Class Codes: B29K 2995/0005 Conductive
• CPC Class Codes: B29K 2995/0049 Heat shrinkable
• CPC Class Codes: C08K 3/08 Metals
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H01B 1/24 the conductive material comprising carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H01B 3/441 from alkenes
• CPC Class Codes: H02G 15/068 connected to the cable shield only H02G15/072 takes precedence
• CPC Class Codes: H02G 15/103 with devices for relieving electrical stress
• CPC Class Codes: H02G 15/105 connected to the cable shield only H02G15/107 takes precedence
• CPC Class Codes: Y10S 138/05 Pre-stress
• CPC Class Codes: Y10S 174/08 Shrinkable tubes
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10T 428/1355 Elemental metal containing [e.g., substrate, foil, film, coating, etc.]
• CPC Class Codes: Y10T 428/1372 Randomly noninterengaged or randomly contacting fibers, filaments, particles, or flakes
• CPC Class Codes: Y10T 428/249922 Embodying intertwined or helical component[s]
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/251 : Mica
• CPC Class Codes: Y10T 428/256 : Heavy metal or aluminum or compound thereof

Abstract

An elastomeric pre-stretched tubular member comprising from about 2.5 to about 25 volume percent carbon black, from about 0.8 to about 3.0 volume percent of platelet-shaped conductive particles, and optionally high permittivity inorganic fillers and platelet-shaped inorganic dielectric fillers, with the balance being the compounded elastomeric component.

Claims

1. An article for use in the splicing and termination of electric power cables comprising an elastomeric tubular member supported in a stretched condition on an easily removable core, said tubular member comprising from about 2.5 to about 25 volume percent carbon black, from about 0.8 to about 3.0 volume percent of platelet-shaped conductive particles, up to about 8.0 volume percent of high permittivity inorganic fillers, up to about 12.0 volume percent of platelet-shaped inorganic dielectric fillers, the balance of said member comprising a compounded non-polar elastomer selected from the group consisting of EPDM and EPM.

2. The article of claim 1 wherein said carbon black is a coarse furnace grade having an average particle diameter of from about 40 to about 100 nanometers.

3. The article of claim 2 wherein said carbon black comprises from about 10 to about 20 volume percent thereof.

4. The article of claim 1 wherein said dielectric filler comprises less than about 5 volume percent thereof.

5. The article of claim 1 wherein said dielectric filler is mica.

6. The article of claim 1 wherein said conductive particles are aluminum.

7. The article of claim 6 wherein said aluminum particles have an average diameter of about 25 micrometers.

8. The article of claim 1 wherein conductive particles are present at from about 1.2 to about 1.8 volume percent thereof.

9. The article of claim 1 wherein said core is a one-piece rigid spiral core having interconnected adjacent coils in a closed helix configuration.

10. The article of claim 1 wherein said high permittivity inorganic fillers comprise barium titanate.