Toughened epoxy thermosets containing core shell rubbers and polyols

1. A curable epoxy resin composition comprising:

a. at least one liquid epoxy resin;

b. at least one epoxy novolac resin;

c. at least one cycloaliphatic epoxy resin;

d. at least one divinylarene dioxide;

e. at least one anhydride hardener;

f. at least one aliphatic polyol

g. a core shell rubber; and

h. at least one catalyst;

wherein the weight ratio of the core shell rubber to the polyol ranges from about 0.1:1 to 15:1;

wherein the at least one liquid epoxy resin comprises bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, or resorcinol diglycidyl ether; and

wherein components a., b., c., and d. are each different.

2. The curable resin composition of claim 1 wherein the epoxy resins (a., b., c., and d.) are present in an amount in the range of from 10 weight percent to 90 weight percent, the at least one anhydride hardener is present in an amount in the range of from 10 weight percent to 90 weight percent, the at least one aliphatic polyol is present in an amount in the range of from 1 weight percent to 30 weight percent, the core shell rubber is present in an amount in the range of from 1 weight percent to 25 weight percent, and the at least one catalyst is present in an amount in the range of from 0.1 weight percent to 10 weight percent, based on the total weight of the curable resin composition.

3. The curable resin composition of claim 1 , wherein the at least one anhydride hardener is selected from the group consisting of aromatic anhydrides, and cycloaliphatic anhydrides.

4. The curable resin composition of claim 1 , wherein the at least one anhydride hardener is nadic-methyl-anhydride or methyl-tetrahydrophthalic anhydride.

5. The curable resin composition of claim 1 , wherein the at least one aliphatic polyol is selected from the group consisting of aliphatic polyether polyols, aliphatic polyester polyols, and aliphatic polycarbonate polyols.

6. The curable resin composition in accordance with claim 5 , wherein the at least one aliphatic polyol is selected from the group consisting of a polyether polyol derived from ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran or mixtures thereof, a polyester polyol derived from succinic acid, glutaric acid, adipic acid, or mixtures thereof copolymerized with ethylene glycol, 1,2-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, glycerol, trimethylolpropane, or mixtures thereof, a polyester polyol derived from caprolactone, a polycarbonate polyol derived from ethylene glycol, 1,2-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, glycerol, trimethylolpropane, or mixtures thereof copolymerized with a carbonate precursor.

7. The curable resin composition of claim 1 wherein the at least one aliphatic polyol component comprises an aliphatic polyol with a number average molecular weight of from 2000 to 12000 and an average functionality of 1.5 to 5.0.

8. The curable resin of claim 1 , wherein the shell of the core shell rubber has limited swellability.

9. The curable resin of claim 1 , wherein the coreshell rubber has a rubber particle core and a shell layer wherein said core shell rubber has a particle size of from 0.01 μm to 0.5 μm.

10. The curable resin composition of claim 1 , wherein the at least one catalyst is selected from the group consisting of imidazoles, substituted imidazoles, quaternary ammonium salts, and chromium compounds.

11. A process for preparing a curable resin composition, the process comprises admixing:

a. at least one liquid epoxy resin;

b. at least one epoxy novolac resin;

c. at least one cycloaliphatic epoxy resin;

d. at least one divinylarene dioxide;

e. at least one anhydride hardener;

f. at least one aliphatic polyol

g. a core shell rubber; and

h. at least one catalyst;

wherein the weight ratio of the core shell rubber to the at least one aliphatic polyol ranges from about 0.1:1 to 15:1;

wherein the at least one liquid epoxy resin comprises bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, or resorcinol diglycidyl ether;

wherein components a., b., c., and d. are each different; and

wherein the above composition is mixed using a high speed mixer.

12. A cured resin composition comprising:

a. at least one liquid epoxy resin;

b. at least one epoxy novolac resin;

c. at least one cycloaliphatic epoxy resin;

d. at least one divinylarene dioxide;

e. at least one anhydride hardener;

f. at least one aliphatic polyol

g. a core shell rubber; and

h. at least one catalyst;

wherein the weight ratio of the core shell rubber to the at least one aliphatic polyol ranges from about 0.1:1 to 15:1;

wherein the at least one liquid epoxy resin comprises bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, or resorcinol diglycidyl ether; and

wherein components a., b., c., and d. are each different.

13. An article made from the cured resin composition of claim 12 , wherein the article is selected from the group consisting of a composite, a coating, a film, a laminate, and an adhesive.