Mica-coated electrically insulating and fire-proofing adhesive tape especially suitable for electrical or optical fiber cable

• US 4,769,276 A
• Filed: 12/15/1986
• Issued: 09/06/1988
• Est. Priority Date: 12/13/1985
• Status: Expired due to Fees

• Current Assignee: Societe Anonyme DBA
• Original Assignee: Alstom Incorporated (Alstom SA)
• Inventors: Gruss, William, Boulaigre, Rene
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Zirker, D. R.
• Application Number:
  US06/941,396
• Time in Patent Office: 631 Days
• Field of Search: 428/324, 428/447, 428/480, 428/343, 428/251, 428/454, 174/122 B, 174/120 C
• US Class Current: 442/296
• CPC Class Codes: H01B 17/60 Composite insulating bodies
• CPC Class Codes: Y10T 428/251 Mica
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 442/3935 Mica paper layer
• CPC Class Codes: Y10T 442/56 From synthetic organic fiber

Abstract

The mica-coated adhesive tape comprises at least one sheet of mica paper and at least one backing sheet bonded to the mica paper sheet by means of a binder, the face of the mica paper sheet away from the backing sheet being coated with an adhesive. The adhesive includes an outer coating of a silicone resin.

Claims

1. An electrically insulating and fire-proof adhesive tape especially for use with electrical cable and optical fiber cable, the tape comprising:

a first layer having an inner side and an outer side, the first layer including at least one sheet of mica paper;

a backing layer disposed on the outer side of the first layer, the backing layer including at least one reinforcing sheet;

a binder bonding the backing layer to the outer side of the first layer, the binder comprising a polysiloxane resin containing a hardening catalyst additive; and

an adhesive layer bonded to the inner side of the first layer, the adhesive layer comprising an exposed pressure-sensitive adhesive coating of a hardenable silicone resin without a hardening additive, such that the coating is capable of retaining pressure-sensitive adhesivity over a long time.

2. An adhesive tape according to claim 1 wherein said silicone resin is a polysiloxane resin.

3. An adhesive tape according to claim 2 wherein said polysiloxane resin is a methylpolysiloxane resin.

4. An adhesive tape according to claim 1 or 2 or 3 wherein the reinforcing sheet comprises a glass cloth having a density of between 15 and 90 gsm.

5. An adhesive tape according to claim 1 or 2 or 3 wherein the reinforcing sheet comprises a warp of 5 to 12 strands per centimeter and of E.C. 5-5.5 to E.C. 9-68 count.

6. An adhesive tape according to claim 1 or 2 or 3 wherein the reinforcing sheet is a synthetic polymer sheet selected from the group consisting of a film, a fabric, and a felt.

7. An adhesive tape according to claim 6 wherein the synthetic polymer is selected from the group consisting of a polyester, a polyimide, and a polycarbonate.

8. An adhesive tape according to claim 1 or 2 or 3 wherein said mica paper sheet is selected from the group consisting of phlogopite and muscovite mica.

9. An adhesive tape according to claim 8 wherein said mica paper sheet has a density of 45 gsm to 200 gsm.

10. An adhesive tape according to claim 1 or 2 or 3 wherein said adhesive layer further comprises a glass cloth having a density of 15 to 90 gsm disposed on the first layer side of said coating and a binder bonding the glass cloth to the inner side of the first layer.

11. An adhesive tape according to claim 1 or 2 or 3 wherein said adhesive layer further comprises a warp of 5 to 12 strands per centimeter of E.C. 5-5.5 to E.C. 9-68 count glass yarns disposed on the first layer side of said coating and a binder bonding the warp to the inner side of the first layer.

12. An adhesive tape according to claim 1 or 2 or 3 wherein said adhesive layer further comprises a synthetic polymer sheet selected from the group consisting of a film, a fabric, and a felt disposed on the first layer side of said coating and a binder bonding the synthetic polymer sheet to the inner side of the first layer.