Stabilized medium and high voltage cable insulation composition

• US 7,056,967 B2
• Filed: 04/05/2002
• Issued: 06/06/2006
• Est. Priority Date: 04/10/2001
• Status: Active Grant

• Current Assignee: CIBA Specialty Chemicals
• Original Assignee: CIBA Specialty Chemicals
• Inventors: Kenny, John, Voigt, Wolfgang
• Primary Examiner(s): WOODWARD, ANA LUCRECIA
• Application Number:
  US10/117,650
• Publication Number:
  US 20020198344A1
• Time in Patent Office: 1,523 Days
• Field of Search: 524/326, 524/331, 524/570
• US Class Current: 524/331
• CPC Class Codes: H01B 3/441 from alkenes

Abstract

The invention relates to a polyethylene composition for use as insulation for wire and cable that has improved scorch resistance comprising

• • (a) a polyethylene
  • (b) a scorch inhibitor having a melting point below 50° C. at atmospheric pressure, and
  • (c) an organic peroxide.

Claims

1. A polyethylene composition having improved scorch resistance consisting essentially of

(a) a polyethylene

(b) a scorch inhibitor having a melting point below 50°

C. at atmospheric pressure and is a compound of the formula I

2. A composition according to claim 1, wherein R¹ is C_1-20alkyl, and R² and R³ are identical and are C_1-20alkyl or C_1-20alky substituted by one or two hydroxyl.

3. A composition according to claim 1, wherein the scorch inhibitor of formula I is 2,4-bis(n-octylthiomethyl)-6-methylphenol or 2,4-bis(n-dodecylthiomethyl)-6-methylphenol.

4. A composition according to claim 1, wherein the amount of scorch inhibitor is in the range from 0.01 to 1 wt % and the amount of the peroxide is in the range from 0.5 to 5 wt %.

5. A polyethylene composition having improved scorch resistance comprising

(a) a polyethylene

(b) a scorch inhibitor having a melting point below 50°

C. at atmospheric pressure and is a compound of the formula I

6. A composition according to claim 5, wherein the amine is 4,4′

-di-tert-octyldiphenylamine or Amine (A) which is a mixture of;

3 wt % diphenylamine, 14 wt % 4-tert-butyldiphenylamine, 30 wt % (4-tert-octyldiphenylamine, 4,4′

-di-tert-butyldiphenylamine and 2,4,4′

-tris-tert-butyldiphenylamine), 29 wt % (4-tert.-butyl-4′

-tert-octyldiphenylamine, o,o′

, m,m′

or p,p′

-di-tert-octyldiphenylamine and 2,4-di-tert-butyl-4′

-tert-octyldiphenylamine), 18 wt % 4,4′

-di-tert-octyl-diphenylamine and 6 wt % 2,4-di-tert-octyl-4′

-tert-butyldiphenylamine.

7. A process for preparing a crosslinked polyethylene composition whereby a polyethylene/peroxide blend is introduced into an extruder and a scorch inhibitor having a melting point below 50°

C. at atmospheric pressure and which is a compound of the formula I