Method for making composite material with blend of thermoplastic particles

1. A method for making a pre-impregnated composite material for curing at a curing temperature, said method comprising the steps of:

A) providing a reinforcing fiber; and

B) impregnating said reinforcing fiber with a matrix wherein said matrix comprises:

a) a resin component comprising a difunctional epoxy resin, a trifunctional meta-glycidyl amine and a tetrafunctional para-glycidyl amine;

b) a thermoplastic particle component comprising high melting thermoplastic particles that have a melting point above said curing temperature and low melting thermoplastic particles that have a melting point at or below said curing temperature;

d) a thermoplastic toughening agent; and

e) a curing agent wherein said curing temperature is between 140° C. and 200° C.

2. A method for making a pre-impregnated composite material according to claim 1 wherein said high melting thermoplastic particles are selected from the group consisting of polyamide 6 and said low melting thermoplastic particles are selected from the group consisting of copolymers of polyamide 6 and polyamide 12.

3. A method for making a pre-impregnated composite material according to claim 1 wherein said reinforcing fibers are selected from the group consisting of glass, carbon and aramid.

4. A method for making a pre-impregnated composite material according to claim 1 wherein said difunctional epoxy resin is selected from the group consisting of diglycidyl ether of bisphenol F, diglycidyl ether of bisphenol A, diglycidyl dihydroxy naphthalene and combinations thereof.

5. A method for making a pre-impregnated composite material according to claim 1 wherein the amount of said high melting thermoplastic particles in said thermoplastic component is about equal to the amount of said low melting thermoplastic particles in said thermoplastic component.

6. A method for making a pre-impregnated composite material according to claim 1 wherein said toughening agent is selected from the group consisting of polyether sulfone, polyether ethersulfone, polyphenyl sulphone, polysulfone, polyimide, polyetherimide, aramid, polyamide, polyester, polyketone, polyetheretherketone, polyurethane, polyurea, polyarylether, polyarylsulphide, polycarbonate and polyphenylene oxide.

7. A method for making a pre-impregnated composite material according to claim 1 wherein said curing agent is an aromatic amine.

8. A method for making a pre-impregnated composite material according to claim 1 wherein said matrix comprises:

40 to 65 weight percent of said resin component;

3 to 10 weight percent of said high melting thermoplastic particles;

3 to 10 weight percent of said low melting thermoplastic particles;

10 to 20 weight percent of said thermoplastic toughening agent; and

15 to 25 weight percent of said curing agent.

9. A method for making a pre-impregnated composite material according to claim 8 wherein said difunctional epoxy resin is diglycidyl ether of bisphenol F.

10. A method for making a pre-impregnated composite material according to claim 8 wherein said high melting thermoplastic particles are selected from the group consisting of polyamide 6 and said low melting thermoplastic particles are selected from the group consisting of copolymers of polyamide 6 and polyamide 12.

11. A method for making a pre-impregnated composite material according to claim 8 wherein said thermoplastic toughening agent is polyether sulfone.

12. A method for making a pre-impregnated composite material according to claim 8 wherein said curing agent is 4,4-diaminodiphenylsulfone.

13. A method for making a pre-impregnated composite material according to claim 8 wherein the amount of said high melting thermoplastic particles in said thermoplastic component is about equal to the amount of and low melting thermoplastic particles in said thermoplastic component.

14. A method for making a pre-impregnated composite material according to claim 8 wherein said matrix comprises

15 to 20 weight percent of diglycidyl ether of bisphenol F;

20 to 30 weight percent of trifunctional meta-glycidyl amine;

5 to 15 weight percent of tetrafunctional para-glycidyl amine

3 to 10 weight percent of polyamide 6 particles;

3 to 10 weight percent of polyamide 6/12 copolymer particles;

10 to 20 weight percent of polyethersulfone; and

15 to 25 weight percent of 4,4-diaminodiphenylsulfone.

15. A method for making a pre-impregnated composite material according to claim 14 wherein the amount of said high melting thermoplastic particles in said thermoplastic component is about equal to the amount of and low melting thermoplastic particles in said thermoplastic component.

16. A method for making a composite part that comprises the method for making a pre-impregnated composite material according to claim 1 and the step of curing said pre-impregnated composite material at said curing temperature.

17. A method for making a composite part according to claim 16 wherein said high melting thermoplastic particles are selected from the group consisting of polyamide 6 and said low melting thermoplastic particles are selected from the group consisting of copolymers of polyamide 6 and polyamide 12.

18. A method for making a composite part according to claim 16 wherein said reinforcing fibers are selected from the group consisting of glass, carbon and aramid.

19. A method for making a composite part according to claim 16 wherein said difunctional epoxy resin is selected from the group consisting of diglycidyl ether of bisphenol F, diglycidyl ether of bisphenol A, diglycidyl dihydroxy naphthalene and combinations thereof.

20. A method for making a composite part according to claim 16 wherein said toughening agent is selected from the group consisting of polyether sulfone, polyether ethersulfone, polyphenyl sulphone, polysulfone, polyimide, polyetherimide, aramid, polyamide, polyester, polyketone, polyetheretherketone, polyurethane, polyurea, polyarylether, polyarylsulphide, polycarbonate and polyphenylene oxide.