Flame and heat resistant electrical insulating tape

• US 4,425,397 A
• Filed: 01/19/1981
• Issued: 01/10/1984
• Est. Priority Date: 09/07/1979
• Status: Expired due to Fees

• Current Assignee: Label-Aire, Inc. (Cenveo Incorporated)
• Original Assignee: Subtex, Inc.
• Inventors: George, Stephen
• Primary Examiner(s): KENDELL, LORRAINE
• Application Number:
  US06/225,888
• Time in Patent Office: 1,086 Days
• Field of Search: 428/245, 428/242, 428/251, 428/253, 428/255, 428/285, 428/286, 428/289, 428/290, 428/343, 428/355, 428/377, 428/383, 428/389, 428/432, 428/426, 428/273, 428/292, 428/268, 174/121 SR, 174/121 A, 174/124 GC, 174/124 G, 174/122 C, 174/110 A, 174/118
• US Class Current: 442/68
• CPC Class Codes: C04B 26/06 Acrylates
• CPC Class Codes: C04B 28/24 containing alkyl, ammonium or metal silicates; containing silica sols reaction mixtures resulting in mineral polymers C04B28/006; polymeric reaction products of alkali metal silicates with isocyanates C08G18/3895
• CPC Class Codes: H01B 3/02 mainly consisting of inorganic substances
• CPC Class Codes: H01B 7/29 Protection against damage caused by extremes of temperature or by flame heat dissipation or conduction H01B7/42
• CPC Class Codes: Y10T 428/2936 Wound or wrapped core or coating [i.e., spiral or helical]
• 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 442/2074 At least one coating or impregnation contains particulate material
• CPC Class Codes: Y10T 442/2672 Phosphorus containing
• CPC Class Codes: Y10T 442/273 Coating or impregnation provides wear or abrasion resistance

Abstract

A flame resistant insulated electrical wire and/or cable construction formed by wrapping a wire or cable conductor with a heat resistant flexible refractory tape comprising a porous base fabric, preferably a knit fiberglass fabric that has been coated and impregnated with refractory materials. These refractory materials are bonded to both the surface and interstices of the base fabric by means of a bonding agent, such that the fabric remains flexible and retains its stretch properties. In the presence of relatively extreme temperature and heat (e.g., above 1750° F.), the bonding agent will decompose without flaming, while the refractory materials will fuse into the softened surface of the knit fiberglass base fabric forming a high temperature resistant structure with ceramic qualities and insulative properties.

Claims

1. A heat resistant, flexible, refractory, electrical insulating tape comprising:

(a) a porous base fabric of a knitted fiberglass, a woven fiberglass or a non-woven, porous web of fiberglass;

(b) a refractory coating comprising refractory materials and a bonding agent of acrylic latex resin or acrylic latex resin and colloidal silica, said refractory coating formed on the surface and interstices of said fabric by applying said refractory coating to both sides of said fabric, and said refractory materials being capable of fusing with the porous base fabric at elevated temperatures; and

(c) an abrasion resistant polymeric coating formed on the outside surface of said refractory coating.

2. A heat resistant, flexible, refractory electrical insulating tape as in claim 1 wherein the polymeric coating is formed on the outside surface of both of the refractory coatings.

3. A heat resistant, flexible refractory electrical insulating tape as in claim 1 wherein the refractory materials are alumina, zirconia, calcium silicate, silicon dioxide or mixtures thereof.

4. A heat resistant, flexible, refractory electrical insulating tape as in claim 1 wherein the bonding also comprises a thickening agent.