Multilayer tube for transportation

Patent metadata

Field	Value
Publication number	US-9410645-B2
Application number	US-201013394394-A
Country	US
Kind code	B2
Filing date	Sep 3, 2010
Priority date	Sep 7, 2009
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

There is provided a multilayer tube for transporting a fuel, a chemical liquid or a gas, which is based on a thermoplastic resin, in particular a polyamide resin, wherein its inner layer comprises an electroconductive thermoplastic resin in which a fine carbon fiber has been blended as an agent imparting an electroconductivity, and it excels in a molding processability, a fuel oil resistance and an antistatic property. This multilayer tube comprises at least two layers of (a) an outer layer comprising a thermoplastic resin, and (b) an inner layer comprising an electroconductive thermoplastic resin so that a surface resistivity is not more than 10 8 Ω; the electroconductive thermoplastic resin comprising a fine carbon fiber, wherein a graphite-net plane consisting solely of carbon atoms forms a temple-bell-shaped structural unit comprising closed head-top part and body-part with open lower-end, 2 to 30 of the temple-bell-shaped structural units are stacked sharing a common central axis to form an aggregate, and the aggregates are connected in head-to-tail style with a distance to form the fiber.

First claim

The invention claimed is:

1. A multilayer tube for transporting a fuel, a chemical liquid or a gas, the multilayer tube comprising at least two layers of
(a) an outer layer comprising a thermoplastic resin, and
(b) an inner layer comprising an electroconductive thermoplastic resin so that a surface resistivity is not more than 10 8 Ω; the electroconductive thermoplastic resin comprising a fine carbon fiber, wherein a graphite-net plane consisting solely of carbon atoms forms a temple-bell-shaped structural unit comprising closed head-top part and body-part with open lower-end where an angle θ formed by a generatrix of the body-part and a fiber axis is less than 15°, 2 to 30 of the temple-bell-shaped structural units are stacked sharing a common central axis to form an aggregate having an aspect ratio L/D of 2 to 30 wherein D is an outer diameter the body-part and L is a length of the aggregate, and the aggregates are connected in head-to-tail style with a distance by van der Waals force to form the fiber.

2. The multilayer tube for transporting a fuel, a chemical liquid or a gas according to claim 1 , wherein the fine carbon fiber is produced by vapor phase growth using a catalyst containing an element selected from the group consisting of Fe, Co, Ni, Al, Mg and Si, and an ash content in the fine carbon fiber is 4% by weight or less.

3. The multilayer tube for transporting a fuel, a chemical liquid or a gas according to claim 1 , wherein the fine carbon fiber is a fine short carbon fiber in which 100 or less of the aggregates are connected.

4. The multilayer tube for transporting a fuel, a chemical liquid or a gas according to claim 1 , wherein the fine short carbon fibers are produced by fiber shortening by applying shear stress.

5. The multilayer tube for transporting a fuel, a chemical liquid or a gas according to any one of claim 1 , wherein the thermoplastic resin constituting the outer layer is a polyamide.

6. The multilayer tube for transporting a fuel, a chemical liquid or a gas according to any one of claim 1 , wherein the electroconductive thermoplastic resin constituting the inner layer is an electroconductive polyamide.

7. The multilayer tube for transporting a fuel, a chemical liquid or a gas according to claim 1 , wherein the electroconductive thermoplastic resin constituting the inner layer is an electroconductive polyamide resin comprising a polyamide obtained from a dicarboxylic acid component comprising oxalic acid and a diamine component comprising a diamine having 4 to 12 carbon atoms.

8. The multilayer tube for transporting a fuel, a chemical liquid or a gas according to claim 1 , wherein the electroconductive thermoplastic resin constituting the inner layer is a polyamide resin obtained by using a diamine component consisting substantively of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, in which a molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is from 1:99 to 99:1.

Assignees

• Nakamura Ken
• Kubo Tsuyoshi
• Ube Industries

Inventors

• Nakamura Ken
• Kubo Tsuyoshi

Classifications

• B32B2262/106

  Carbon fibres, e.g. graphite fibres · CPC title

• B32B27/34

  comprising polyamides · CPC title

• B32B1/08

  Tubular products · CPC title

• F16L11/18

  Articulated hoses, e.g. composed of a series of rings · CPC title

• B32B27/32

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title