Water blocking composites and their use in cable manufacture

• US 5,925,461 A
• Filed: 05/23/1995
• Issued: 07/20/1999
• Est. Priority Date: 06/02/1994
• Status: Expired due to Term

• Current Assignee: NEPTCO JV LLC (Chase Corporation)
• Original Assignee: NEPTCO, Inc. (Chase Corporation)
• Inventors: Fairgrieve, Stuart Paterson
• Primary Examiner(s): Krynski, William
• Assistant Examiner(s): GRAY, JILL M
• Application Number:
  US08/447,953
• Time in Patent Office: 1,519 Days
• Field of Search: 428/372, 428/375, 428/378, 428/379, 428/396, 428/373, 428/392, 428/394
• US Class Current: 428/372
• CPC Class Codes: G02B 6/4434 Central member to take up tensile loads
• CPC Class Codes: G02B 6/44384 the means comprising water blocking or hydrophobic materials G02B6/4439, G02B6/4479 take precedence
• CPC Class Codes: H01B 3/008 Other insulating material
• CPC Class Codes: H01B 7/288 using hygroscopic material or material swelling in the presence of liquid
• CPC Class Codes: Y10T 428/2927 including structurally defined particulate matter
• CPC Class Codes: Y10T 428/2933 Coated or with bond, impregnation or core
• CPC Class Codes: Y10T 428/2938 Coating on discrete and individual rods, strands or filaments
• CPC Class Codes: Y10T 428/2964 Artificial fiber or filament
• CPC Class Codes: Y10T 428/2967 Synthetic resin or polymer
• CPC Class Codes: Y10T 428/2971 Impregnation

Abstract

A water blocking composite for use in cables which includes an article selected from the group having one or more strengthening members and buffer tubes impregnated with or coated with a mixture of a thermoplastic resin and a water-swellable particulate material.

Claims

1. A water blocking composite for cables which comprises one or more strengthening members or buffer tubes impregnated with or coated with a formulation consisting of a hot melt adhesive having dispersed therein from 20 to 50 parts by weight of a water-swellable particulate material to 100 parts by weight of said hot melt adhesive.

2. A composite as claimed in claim 1 wherein the strengthening member is a central strengthening member, an intermediate strengthening member, a spacer, or an outer strengthening wrap.

3. A composite as claimed in claim 2 wherein the strengthening member is fabricated from a fibrous material comprising one of glass fiber and aramid fiber.

4. A composite as claimed in claim 1 wherein the hot melt adhesive is an ethylene vinylacetate based hot melt adhesive.

5. A composite as claimed in claim 1 wherein the water swellable particulate material comprises a superabsorbent polymer.

6. A composite as claimed in claim 5 wherein the superabsorbent polymer is a partially cross-linked acrylate polymer.

7. A composite as claimed in claim 1 wherein the formulation consists of 30 parts by weight of water-swellable particulate material to 100 parts by weight of an ethylene vinylacetate based hot melt adhesive.