Curable flame retardant epoxy compositions
View Patent ↗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 micelle 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.
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 resin composition of claim 2 wherein the brominated epoxy is tetrabromobisphenol A diglycidyl ether.
4. The curable composition of claim 1 wherein the flame retardant epoxy resin is a phosphorous-containing epoxy resin.
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 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.
6. 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.
7. The curable composition of claim 1 wherein the block copolymer is a diblock copolymer.
8. The curable composition of claim 1 wherein the block copolymer is poly(ethylene oxide)-poly(ethylene-alt-propylene) (PEO-PEP).
9. 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).
10. The curable composition of claim 1 wherein the amount of block copolymer is from about 0.1 weight percent to about 30 weight percent.
11. The curable composition of claim 1 wherein the epoxy resin is dygliciyl ether of bisphenol A.
12. The curable composition of claim 1 wherein the curing agent is a phenol novolac.
13. The curable composition of claim 1 including a solvent.
14. 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.
15. The curable resin composition of claim 14 , wherein the catalyst is an imidazole.
16. A fiber reinforced composite article comprising a matrix including a curable epoxy resin composition according to claim 1 .
17. The fiber reinforced composite article of claim 16 , which is a laminate or a prepreg for an electric circuit.
18. An electric circuit component having an insulating coating of the epoxy resin composition according to claim 1 .
19. 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.
20. A prepreg comprising:
(a) a woven fabric, and
(b) a curable epoxy resin composition of claim 1 .
21. 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.
22. The laminate of claim 21 wherein the substrate further comprises a reinforcement of a woven glass fabric, wherein the epoxy resin composition is impregnated on the woven glass fabric.
23. A printed wiring board (PWB) made of the laminate of claim 22 .
24. 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.
25. A cured resin product comprising a flame retardant epoxy resin containing a block copolymer self-assembled into a worm-like micelle morphology.
26. 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.