Plastic-based multilayer structure and tube having a multilayer structure

• US 20030008087A1
• Filed: 05/28/2002
• Published: 01/09/2003
• Est. Priority Date: 12/20/1996
• Status: Active Grant

• Current Assignee: Nicolangelo Peduto
• Original Assignee: Nicolangelo Peduto
• Inventors: Peduto, Nicolangelo
• Granted Patent: US 6,964,800 B2
• Time in Patent Office: Days
• US Class Current: 428/35.7
• CPC Class Codes: B32B 1/00 Layered products having a non-planar shape
• CPC Class Codes: B32B 1/08 Tubular products
• CPC Class Codes: B32B 2307/7242 Non-permeable
• CPC Class Codes: B32B 2307/7265 Non-permeable
• CPC Class Codes: B32B 2307/734 Dimensional stability
• CPC Class Codes: B32B 2597/00 Tubular articles, e.g. hoses, pipes
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/22 using plasticisers
• CPC Class Codes: B32B 27/30 comprising vinyl (co)polymers; comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/304 comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B60K 15/01 Arrangement of fuel conduits chassis frame forming fluid conduit means B62D21/17
• CPC Class Codes: F02M 37/0017 related to fuel pipes or their connections, e.g. joints or sealings F02M55/004 takes precedence
• CPC Class Codes: F16L 11/04 made of rubber or flexible plastics
• CPC Class Codes: F16L 2011/047 with a diffusion barrier layer
• CPC Class Codes: F16L 9/12 of plastics with or without reinforcement F16L9/16 - F16L9/22 take precedence
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1379 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/1393 Multilayer [continuous layer]
• CPC Class Codes: Y10T 428/3154 Of fluorinated addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31576 : Ester monomer type [polyvinylacetate, etc.]
• CPC Class Codes: Y10T 428/3158 : Halide monomer type [polyvinyl chloride, etc.]
• CPC Class Codes: Y10T 428/31743 : Next to addition polymer from unsaturated monomer[s]

Abstract

The invention concerns a plastic-based multilayer structure, in particular for making tubes or conduits for transporting liquid fluids such as alcohol, liquid fuels derived from petrol, fuels containing oxygen compounds such as, for instance alcohol. More particularly it concerns a multilayer structure with improved barrier properties, in particular with respect to the fluids mentioned above. Said structure comprises an external layer (A) formed from a polyamide based composition with and an internal adjacent layer (B) formed from a polyfluorovinylidene based composition. The adherence between these two layers is obtained either by adding a polyacrylate compound commercialised under the registered trade mark RESEDA in the polymer forming the layer (B) or by forming an intermediate layer between the adjacent layers (A) and (B) from a composition containing said RESEDA compound.

Claims

1. Multilayer structure comprising at least one layer (A) formed from a polyamide-based composition and at least one adjacent layer (B) formed from a polyvinylidene-fluoride-based composition, characterized in that the polyamide-based composition and/or the polyvinylidene-fluoride-based composition comprise a polyacrylate compound comprising the repeat units of the following formulae:

3. Structure according to one of the preceding claims, characterized in that it forms the walls of a hollow article, such as a tube, pipe or tank.

4. Structure according to one of the preceding claims, characterized in that the polyamide is chosen from aliphatic polyamides and copolyamides such as PA 4,6;

PA 6,6;

PA 6,12;

PA 6,10;

PA 6;

PA 11;

PA 12;

PA 6,36;

PA 6/6,36, and mixtures of these polyamides.

5. Structure according to one of the preceding claims, characterized in that the polyamide is a blend of a PA 6 and a PA 6/6,36 copolyamide.

6. Structure according to one of the preceding claims, characterized in that the expression F in the formula R₄-F represents an epoxy functional group.

7. Structure according to claim 6, characterized in that the radical R₂ is the glycidyl radical.

8. Structure according to one of the preceding claims, characterized in that the concentration of functional radical F in the polyacrylate compound is between 0.1 meq/g and 1 meq/g of polyacrylate compound.

9. Structure according to one of the preceding claims, characterized in that the polyacrylate compound comprises repeat units of formula (iii) in which R₅ is a polymethyl methacrylate chain.

10. Structure according to one of the preceding claims, characterized in that the polyacrylate compound is present in the polyvinylidene-fluoride-based composition in a concentration by weight of between 5% and 25% of the polyacrylate compound with respect to the weight of the composition.

11. Structure according to claim 10, characterized in that the concentration of polyacrylate compound is between 10 and 20%.

12. Structure according to one of claims 2 to 11, characterized in that the intermediate layer (C) comprises a polyvinylidene fluoride and/or a polyamide.

13. Structure according to one of claims 2 to 12, characterized in that the intermediate layer (C) has the following composition by weight:

5% -100% of acrylate compound

0% -95% of polyvinylidene fluoride

0% -90% of polyamide,

and when the polyamide is present in the layer C, the concentration by weight of polyvinylidene fluoride is greater than 5%, the sum of these concentrations being equal to 100%.

14. Structure according to one of claims 2 to 13, characterized in that the composition forming the layer (A) comprises a polyacrylate defined according to claim 1.

15. Structure according to one of the preceding claims, characterized in that the polyamide composition forming the layer (A) comprises a plasticizer.

16. Use of a multilayer structure according to one of claims 1 to 15, for the manufacture of pipes or tanks intended for containing fuels, preferably oxygenated fuels.

17. Use according to claim 16, characterized in that the pipes are fuel pipes for combustion engines.

18. Use of a multilayer structure according to one of claims 1 to 15 for the manufacture of hollow bodies by coextruding the layers of the said structure.

2. Multilayer structure comprising at least one layer (A) formed from a polyamide-based composition and at least one adjacent layer (B) formed from a polyvinylidene-fluoride-based composition, characterized in that it comprises an adhesive intermediate layer (C) placed between the layers (A) and (B), the said layer (C) being formed from a composition comprising at least one polyacrylate compound comprising repeat units of the following formulae: