Resin-soluble thermoplastic veil for composite materials

• US 20060252334A1
• Filed: 05/08/2006
• Published: 11/09/2006
• Est. Priority Date: 05/09/2005
• Status: Active Grant

• Current Assignee: Cytec Technology Corp. (Syensqo SA)
• Original Assignee: Cytec Technology Corp. (Syensqo SA)
• Inventors: LoFaro, Carmelo, Webb, William Erwin, Abusafieh, Abdel, Doyle, Marc
• Granted Patent: US 8,703,630 B2
• Time in Patent Office: Days
• US Class Current: 442/400
• CPC Class Codes: B32B 2250/20 All layers being fibrous or filamentary
• CPC Class Codes: B32B 2260/023 Two or more layers
• CPC Class Codes: B32B 2262/02 Synthetic macromolecular fibres
• CPC Class Codes: B32B 2262/0207 Elastomeric fibres
• CPC Class Codes: B32B 2262/0215 Thermoplastic elastomer fibers
• CPC Class Codes: B32B 2307/54 Yield strength; Tensile strength
• CPC Class Codes: B32B 2307/558 Impact strength, toughness
• CPC Class Codes: B32B 2307/718 Weight, e.g. weight per square meter
• CPC Class Codes: B32B 2307/7242 Non-permeable
• CPC Class Codes: B32B 2307/7265 Non-permeable
• CPC Class Codes: B32B 2605/18 Aircraft
• CPC Class Codes: B32B 5/022 Non-woven fabric
• CPC Class Codes: B32B 5/08 the fibres or filaments of a layer being of different substances , e.g. conjugate fibres, mixture of different fibres
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: B32B 7/10 at least one layer having inter-reactive properties
• CPC Class Codes: C08J 5/046 with synthetic macromolecular fibrous material
• CPC Class Codes: Y10T 428/249933 Fiber embedded in or on the surface of a natural or synthetic rubber matrix
• CPC Class Codes: Y10T 428/249934 Fibers are aligned substantially parallel
• CPC Class Codes: Y10T 428/249939 Two or more layers
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix
• CPC Class Codes: Y10T 428/249942 : Fibers are aligned substantially parallel
• CPC Class Codes: Y10T 428/249947 : Polymeric fiber
• CPC Class Codes: Y10T 428/249949 : Two or more chemically different fibers
• CPC Class Codes: Y10T 428/24995 : Two or more layers
• CPC Class Codes: Y10T 428/249952 : At least one thermosetting synthetic polymeric material layer
• CPC Class Codes: Y10T 442/198 : Coated or impregnated
• CPC Class Codes: Y10T 442/20 : Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
• CPC Class Codes: Y10T 442/2033 : Coating or impregnation formed in situ [e.g., by interfacial condensation, coagulation, precipitation, etc.]
• CPC Class Codes: Y10T 442/30 : Woven fabric [i.e., woven strand or strip material]
• CPC Class Codes: Y10T 442/3569 : Woven fabric layers impregnated with a thermosetting resin
• CPC Class Codes: Y10T 442/3707 : Woven fabric including a nonwoven fabric layer other than paper
• CPC Class Codes: Y10T 442/3715 : Nonwoven fabric layer comprises parallel arrays of strand material
• CPC Class Codes: Y10T 442/3789 : Plural nonwoven fabric layers
• CPC Class Codes: Y10T 442/637 : Including strand or fiber material which is a monofilament composed of two or more polymeric materials in physically distinct relationship [e.g., sheath-core, side-by-side, islands-in-sea, fibrils-in-matrix, etc.] or composed of physical blend of chemically different polymeric materials or a physical blend of a polymeric material and a filler material
• CPC Class Codes: Y10T 442/68 : Melt-blown nonwoven fabric

Abstract

A resin-soluble thermoplastic polymer veil toughening element for a curable composition wherein the polymer element is a non-woven veil in solid phase adapted to undergo at least partial phase transition to fluid phase on contact with a component of the curable resin matrix composition in which it is soluble at a temperature which is less than the temperature for substantial onset of gelling and/or curing of the curable composition and which temperature is less than the polymer elements melt temperature; a method for the preparation thereof, a preform support structure for a curable composition comprising the at least one thermoplastic veil element together with structural reinforcement fibers, methods for preparation thereof, a curable composition comprising the at least one thermoplastic veil element or the support structure and a curable resin matrix composition, a method for preparation and curing thereof, and a cured composite or resin body obtained thereby, and known and novel uses thereof.

Claims

1. A thermoplastic toughening element for composite manufacturing comprising a plurality of resin-soluble thermoplastic fibers.

2. The toughening element of claim 1 wherein the plurality of resin-soluble thermoplastic fibers are randomly adhered to one another into a veil.

3. The toughening element of claim 2 wherein the veil is characterized by an areal weight of about 5 to about 80 gsm.

4. The toughening element of claim 2 adapted for localized toughening.

5. The toughening element of claim 1 wherein the fibers comprise a first resin-soluble thermoplastic material and a second resin-soluble thermoplastic material.

6. The toughening element of claim 5 wherein the first resin-soluble thermoplastic material and the second resin-soluble thermoplastic material are the same.

7. The toughening element of claim 5 wherein the first material and the second material are different.

8. The toughening element of claim 1 wherein the resin-soluble thermoplastic is selected from the group consisting of cellulose derivatives, polyester, polyamide, polimide, polycarbonate, polyurethane, poly(methyl methacrylate), polystyrene, polyaromatics;

polyesteramide, polyamideimide, polyetherimide, polyaramide, polyarylate, polyacrylate, poly(ester) carbonate, poly(methyl methacrylate/butyl acrylate), polysulphone, polyethersulphone, polyetherethersulphone polyethersulphone-etherketone, and copolymers and combinations thereof.

9. The toughening element of claim 1 wherein the fibers solubilize in a curable resin matrix at a first temperature less than a second cure temperature of the curable resin matrix.

10. The toughening element of claim 9 wherein the solubilized fibers are capable of chain linking with the curable resin matrix at the second cure temperature of the curable resin matrix.

11. The toughening element of claim 1 wherein the resin-soluble thermoplastic fibers are adapted to be in a solid phase and to undergo at least partial phase transition to fluid phase on contact with a curable resin matrix in which the thermoplastic fibers are soluble, at a first temperature for substantial dissolution, which is less than a second temperature for substantial onset of curing of the curable resin matrix.

12. The toughening element of claim 1 wherein the fibers are adapted to carry modifiers.

13. A toughening element for a curable composition comprising a resin-soluble thermoplastic veil adapted to be interposed between layers of reinforcement fibers wherein the resin-soluble thermoplastic veil is in a solid phase and adapted to undergo at least partial phase transition to a fluid phase on contact with a curable composition in which it is soluble, at a first temperature for substantial dissolution, which is less than a second temperature for substantial onset of gelling and/or curing of the curable composition and which first temperature is less than a third temperature for substantial melting of the resin-soluble thermoplastic veil.

14. The toughening element of claim 13 wherein the layers of reinforcement fibers form a preform, and wherein the resin-soluble thermoplastic veil is capable of stabilizing the preform.

15. A method of manufacturing a toughening element comprising the steps of:

heat blow extruding a resin-soluble thermoplastic into a thread;

distributing the thread onto a mandrel;

heating the threads on the mandrel to form a veil;

cooling the veil.

16. The method of manufacturing of claim 15 wherein the thread is continuous.

17. The method of manufacturing of claim 15 wherein the thread is chopped into a plurality of chopped fibers.

18. A preform for composite manufacturing comprising:

a structural component comprising reinforcement fibers;

a toughening element comprising resin-soluble thermoplastic fibers;

wherein the toughening element is in the form of a non-woven veil in contact with the structural component.

19. The preform for composite manufacturing of claim 18 wherein the structural component is provided in the form of a plurality of adjacent reinforcement fiber layers and wherein the toughening element is provided in the form of a plurality of veils interposed between pairs of adjacent reinforcement fiber layers.

20. The preform for composite manufacturing of claim 18 adapted for resin infusion.

21. The preform for composite manufacturing of claim 18 wherein the preform is stabilized.

22. The preform for composite manufacturing of claim 18 wherein the toughening element is in a solid phase and adapted to substantially remain in a soluble phase when contacted with a curable resin matrix at a first temperature for resin infusion, which is less than a second temperature for substantial dissolution of the toughening element.

23. The preform for composite manufacturing of claim 18 wherein the toughening element is in a solid phase and adapted to undergo at least partial phase transition to fluid phase when contacted with a curable resin matrix in which it is soluble at a first temperature for dissolution, which first temperature is less than a second temperature for substantial onset of curing.

24. The preform for composite manufacturing of claim 23 wherein the toughening element substantially reacts with the curable resin matrix at the second temperature.