PROCESS FOR IMPROVING THE ADHESION OF CARBON FIBRES WITH REGARD TO AN ORGANIC MATRIX

• US 20100092695A1
• Filed: 12/10/2007
• Published: 04/15/2010
• Est. Priority Date: 12/11/2006
• Status: Active Grant

• Current Assignee: ArianeGroup SAS
• Original Assignee: Astrium Sas (Airbus SE)
• Inventors: Schultz, Jacques, Vautard, Frederic, Nardin, Michel, Roucoules, Vincent, Defoort, Brigitte
• Granted Patent: US 8,399,064 B2
• Time in Patent Office: Days
• US Class Current: 427/569
• CPC Class Codes: C08J 5/06 using pretreated fibrous materials
• CPC Class Codes: D06M 14/36 on to carbon fibres
• CPC Class Codes: D06M 15/273 of unsaturated carboxylic esters having epoxy groups
• CPC Class Codes: D06M 15/2735 of unsaturated carboxylic esters having mercapto groups
• CPC Class Codes: D06M 2101/40 Fibres of carbon

Abstract

The present invention relates to a process which makes it possible to improve the adhesion of carbon fibres with regard to an organic matrix forming, with these fibres, a composite material, this composite material being obtained by bringing the fibres into contact with a resin which can be cured by chain polymerization, followed by polymerization of the resin, which process consists in coating the surface of the carbon fibres, before these fibres are brought into contact with the resin, with a polymer film which comprises functional groups capable of acting as chain transfer agents during the polymerization of said resin.

Applications: aeronautical, aerospatial, shipbuilding, railway and motor vehicle industries, armaments industry, sports and leisure articles, and the like.

Claims

1-18. -18. (canceled)

19. A process for improving the adhesion of carbon fibres with regard to an organic matrix forming, with these fibres, a composite material, this composite material being obtained by bringing the fibres into contact with a resin which can be cured by chain polymerization, followed by polymerization of the resin, which process consists in coating the surface of the carbon fibres, before these fibres are brought into contact with the resin, with a polymer film which comprises functional groups capable of acting as chain transfer agents during the polymerization of said resin.

20. The process according to claim 19, in which the functional groups capable of acting as chain transfer agents are —

I, —

Br, —

Cl, —

F, —

SH, —

OH, —

NH—

, —

NH₂, —

PH, —

PH₂ or ═

S functional groups.

21. The process according to claim 20, in which the functional groups capable of acting as chain transfer agents are thiol functional groups.

22. The process according to claim 19, in which the surface of the carbon fibres is coated with said polymer film by polymerization on this surface of a polymerizable monomer comprising the functional groups capable of acting as chain transfer agent.

23. The process according to claim 19, in which the surface of the carbon fibres is coated with said polymer film by:

a) polymerization on this surface of a polymerizable monomer comprising a functional group which can be converted to a functional group capable of acting as chain transfer agent, then

b) conversion of the functional groups which the polymer film thus obtained comprises.

24. The process according to claim 19, in which the surface of the carbon fibres is coated with said polymer film by:

a) polymerization on this surface of a polymerizable monomer, then

b) grafting to the polymer film thus obtained of functional groups capable of acting as chain transfer agents.

25. The process according to claim 24, in which the grafting is carried out by reacting the functional groups present at the surface of the polymer film with an organic compound which, by ring opening, becomes covalently bonded to said functional groups and generates groups comprising a functional group capable of acting as chain transfer agent.

26. The process according to claim 25, in which the functional groups present at the surface of the polymer film are carboxyl functional groups and are reacted with an episulphide, which generates groups comprising a thiol functional group.

27. The process according to claim 26, in which the polymer film comprising carboxyl functional groups is obtained by polymerization of a polymerizable acid or of a polymerizable acid derivative.

28. The process according to claim 27, in which the polymerizable acid derivative is an acid anhydride.

29. The process according to claim 27, in which the episulphide is selected from the group consisting of propylene sulphide, ethylene sulphide, cyclohexene sulphide, epithiodecane, epithiododecane and 7-thiabicyclo[4.1.0]heptane.

30. The process according to claim 19, in which the polymer film exhibits a thickness ranging from 10 to 50 nm.

31. The process according to claim 19, in which the polymer film is obtained by Plasma Assisted Chemical Vapour Deposition (PACVD).

32. The process according to claim 31, in which the plasma is pulsed-mode radiofrequency-induced.

33. A process for the manufacture of a component made of composite material comprising carbon fibres and an organic matrix, which process comprises bringing the fibres into contact with a resin which can be cured by chain polymerization and polymerizing the resin and implementing the process according to claim 19, before the fibres are brought into contact with said resin.

34. The process according to claim 33, in which the resin is a resin which can be polymerized under radiation.

35. The process according to claim 34, in which the resin is chosen from epoxy acrylate resins, novolac acrylates, polyurethane acrylates, bismaleimide resins and epoxide resins.

36. The process according to claim 35, characterized in that the resin is an epoxy acrylate resin.

37. The process according to claim 27, in which the polymerizable acid derivative is maleic anhydride.

38. A process for making a composite material, comprising:

coating the surface of carbon fibers with a polymer film which comprises at least one functional group which can act as a chain transfer agent, to obtain coated carbon fibers;

contacting said coated carbon fibers with a resin curable by chain polymerization; and

curing the resin.