Gas-impermeable elastic membrane and hydropnematic accumulator equipped with this measure

• US 6,350,529 B1
• Filed: 02/17/1998
• Issued: 02/26/2002
• Est. Priority Date: 02/17/1997
• Status: Expired due to Fees

• Current Assignee: Elf Atochem S.A.
• Original Assignee: Elf Atochem S.A.
• Inventors: Beal, Jean-Luc, Le Roy, Christophe, Germain, Yves
• Primary Examiner(s): KILIMAN, LESZEK B
• Application Number:
  US09/024,313
• Time in Patent Office: 1,470 Days
• Field of Search: 428/36.8, 428/500, 428/475.8, 428/476.3, 427/384, 427/383.5, 427/377.2
• US Class Current: 428/476.3
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B60G 2206/4222 with a flexible separating wall; Membrane construction
• CPC Class Codes: F15B 1/10 with flexible separating means
• CPC Class Codes: F15B 2201/205 using gas
• CPC Class Codes: F15B 2201/3151 the flexible separating means being diaphragms or membranes
• CPC Class Codes: F15B 2201/3155 characterised by the material of the flexible separating means
• CPC Class Codes: F15B 2201/32 having multiple separating means, e.g. with an auxiliary piston sliding within a main piston, multiple membranes or combinations thereof
• CPC Class Codes: Y10T 428/12111 Separated by nonmetal matrix or binder [e.g., welding electrode, etc.]
• CPC Class Codes: Y10T 428/1386 Natural or synthetic rubber or rubber-like compound containing
• CPC Class Codes: Y10T 428/31743 Next to addition polymer from unsaturated monomer[s]
• CPC Class Codes: Y10T 428/3175 Next to addition polymer from unsaturated monomer[s]

Abstract

A gas-impermeable elastic membrane including a co-polymeric gas-impermeable film including OH groups, positioned between two layers of a co-polymer containing blocks of polyamides and of polyesters, with a rubber coating on at least one of the two layers, as well as a method of manufacturing the membrane.

Claims

1. A gas-impermeable elastic membrane, said membrane comprising at least:

(a) a co-polymeric gas-impermeable film including OH groups; and

(b) two layers of a supple and elastic material of a co-polymer containing blocks of polyamides and blocks of polyethers, said film being positioned between said layers.

2. The elastic impermeable membrane set forth in claim 1, wherein the film includes a co-polymer of ethylene and vinyl alcohol.

3. The elastic impermeable membrane set forth in claim 1, wherein the thickness of the film is between 25 and 100 μ

m.

4. The elastic impermeable membrane set forth in claim 1, wherein the thickness of the supple and elastic layers is between 200 and 600 μ

m.

5. The elastic impermeable membrane set forth in claim 1, further including a rubber coating positioned on at least one of said layers of elastic and supple material.

6. The elastic impermeable membrane set forth in claim 5, wherein the rubber coating is located on each of the layers.

7. The elastic impermeable membrane set forth in claim 5, wherein the rubber of the coating is a co-polymer of 1.3 butadiene, of acrylonitrile and acrylic acid.

8. A method for manufacturing a membrane comprising the steps of:

(a) preparing a formed film having two layers by coextrusion;

(b) thermal forming said film;

(c) molding said film with non-vulcanized rubber as a coating; and

(d) vulcanizing the rubber at a temperature sufficient to complete vulcanization but below a fusion temperature.