CURABLE FLAME RETARDANT EPOXY RESIN COMPOSITIONS

• US 20040247881A1
• Filed: 06/06/2003
• Published: 12/09/2004
• Est. Priority Date: 06/06/2003
• Status: Active Grant

• Current Assignee: Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Regents of The University of Minnesota (University of Minnesota)
• Inventors: Vergese, Nikhil E., Bates, Frank S., Pham, Ha Q., Dean, Jennifer M.
• Granted Patent: US 6,887,574 B2
• Time in Patent Office: Days
• US Class Current: 428/413
• CPC Class Codes: C08G 2650/58 Ethylene oxide or propylene oxide copolymers, e.g. pluronics
• CPC Class Codes: C08L 2666/22 Macromolecular compounds not provided for in C08L2666/16 - C08L2666/20
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 33/068 containing glycidyl groups
• CPC Class Codes: C08L 33/10 Homopolymers or copolymers of methacrylic acid esters
• CPC Class Codes: C08L 59/00 Compositions of polyacetals; Compositions of derivatives of polyacetals of polyvinyl acetals C08L29/14
• CPC Class Codes: C08L 63/00 Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• CPC Class Codes: C08L 71/02 Polyalkylene oxides
• CPC Class Codes: H05K 1/0326 containing O
• CPC Class Codes: H05K 1/0373 containing additives, e.g. fillers H05K1/036 takes precedence
• CPC Class Codes: H05K 2201/0212 Resin particles
• CPC Class Codes: Y10S 428/901 Printed circuit
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix
• CPC Class Codes: Y10T 428/2971 Impregnation
• CPC Class Codes: Y10T 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 428/31515 As intermediate layer
• CPC Class Codes: Y10T 428/31522 Next to metal
• CPC Class Codes: Y10T 428/31529 Next to metal

Abstract

A curable flame retardant epoxy resin composition including (a) at least one flame retardant epoxy resin; (b) at least one amphiphilic block copolymer; and (c) a curing agent. Such components are present in the curable composition in the appropriate amounts and ratios such that, upon curing, the block copolymer self-assembles into a nano structure morphology, such as a worm-like miscelle morphology. The resulting cured product made from the composition of the present invention has a remarkably increased high fracture resistance; and allows the use of flame retardant epoxies in applications where fracture resistance is an issue.

Claims

1. A curable flame retardant epoxy resin composition with increased toughness comprising:

(a) at least one curable flame retardant epoxy resin;

(b) an amphiphilic block copolymer in an amount such that said amphiphilic block copolymer self assembles into micellar morphologies and such that the fracture resistance of the resulting cured product increases; and

(c) a curing agent.

2. The curable composition of claim 1 wherein the flame retardant epoxy resin is a brominated epoxy resin.

3. The curable composition of claim 1 wherein the flame retardant epoxy resin is a phosphorous-containing epoxy resin.

4. The curable composition of claim 1 wherein the block copolymer is present in an amount such that, upon mixing in the un-cured state, the block copolymer self-assembles into a worm-like micelle morphology;

such that the morphology persists through the curing of the composition; and

such that the fracture resistance of the resulting cured product increases.

5. The curable composition of claim 1 wherein the block copolymer is present in an amount such that, upon mixing in the un-cured state, the block copolymer self-assembles into a spherical micelle morphology;

such that the morphology persists through the curing of the composition; and

such that the fracture resistance of the resulting cured product increases.

6. The curable composition of claim 1 wherein the block copolymer is a diblock copolymer.

7. The curable composition of claim 1 wherein the block copolymer is poly(ethylene oxide)-poly(ethylene-alt-propylene) (PEO-PEP).

8. The curable composition of claim 1 wherein the block copolymer is poly(methyl methacrylate-ran-glycidyl methacrylate)-poly(2-ethylhexyl methacrylate) (P(MMA-ran-GMA)-PEHMA).

9. The curable composition of claim 1 wherein the amount of block copolymer is from about 0.1 weight percent to about 30 weight percent.

10. The curable composition of claim 1 wherein the epoxy resin is dygliciyl ether of bisphenol A.

11. The curable composition of claim 1 wherein the curing agent is a phenol novolac.

12. The curable composition of claim 1 including a solvent.

16. The curable resin composition of claim 1 including a catalytic amount of a catalyst for accelerating the reaction of the flame retardant epoxy resin with the curing agent.

17. The curable resin composition of claim 16, wherein the catalyst is an imidazole.

18. The curable resin composition of claim 2 wherein the brominated epoxy is tetrabromobisphenol A diglycidyl ether.

19. A fiber reinforced composite article comprising a matrix including a curable epoxy resin composition according to claim 1.

20. The fiber reinforced composite article of claim 19, which is a laminate or a prepreg for an electric circuit.

21. An electric circuit component having an insulating coating of the epoxy resin composition according to claim 1.

22. A process of producing a coated article, comprising coating an article with a curable epoxy resin according to claim 1, and heating the coated article to cure the epoxy resin.

23. A prepreg comprising:

(a) a woven fabric, and

(b) a curable epoxy resin composition of claim 1.

24. A laminate comprising:

(a) a substrate including a resin composition of an epoxy resin of claim 1;

and

(b) a layer of metal disposed on at least one surface of said substrate.

25. The laminate of claim 24 wherein the substrate further comprises a reinforcement of a woven glass fabric, wherein the epoxy resin composition is impregnated on the woven glass fabric.

26. A printed wiring board (PWB) made of the laminate of claim 25.

13. A process for preparing a curable resin composition comprising mixing:

(a) at least one curable flame retardant epoxy resin;

(b) an amphiphilic block copolymer in an amount such that said amphiphilic block copolymer self assembles into micellar morphologies and such that the fracture resistance of the resulting cured product increases; and

(c) a curing agent.

14. A cured resin product comprising a flame retardant epoxy resin containing a block copolymer self-assembled into a worm-like micelle morphology.

15. A process for preparing a cured resin product comprising heating a mixture of:

(a) at least one curable flame retardant epoxy resin;

(b) an amphiphilic block copolymer in an amount such that said amphiphilic block copolymer self assembles into micellar morphologies and such that the fracture resistance of the resulting cured product increases; and

(c) a curing agent.