Dual cure resin for the production of moisture-resistant articles by additive manufacturing

1. A dual cure resin useful for the production of objects by stereolithography, said dual cure resin comprising a mixture of:

(a) a light-polymerizable component; and

(b) a heat-polymerizable component, said heat-polymerizable component comprising:

(i) a dicyclopentadiene-containing polyepoxide resin;

(ii) a cyanate ester resin;

(iii) an epoxy-reactive toughening agent, wherein the epoxy-reactive toughening agent comprises a compound of Formula I:

wherein

m is 1 or 2;

n is 2 to 6;

R 0 is an n-valent radical of an elastomeric prepolymer, the elastomeric prepolymer being soluble or dispersible in epoxy resign;

X and Y independent of one another are —O— or —NR 3 —, at least one X or Y being —NR 3 —;

R 2 is an m+1-valent radical of polyphenol or aminophenol after the removal of the phenolic hydroxyl group(s) and optionally of the amino group; and

R 3 is hydrogen, C 1 -C 6 alkyl, phenyl or phenol; and

(iv) a core shell rubber toughener.

2. The dual cure resin of claim 1 , wherein said core shell rubber toughener comprises a polybutadiene core.

3. The dual cure resin of claim 1 , wherein said cyanate ester resin comprises a bisphenol cyanate ester.

4. The dual cure resin of claim 1 , wherein said light- polymerizable component comprises:

(i) a light polymerizable monomer; and

(ii) a photoinitiator.

5. The dual cure resin of claim 4 , wherein the light polymerizable monomer comprises an acrylate or a methacrylate.

6. The dual cure resin of claim 1 , wherein said dual cure resin is homogeneous.

7. The dual cure resin of claim 1 , wherein said dual cure resin is nonaqueous.

8. A method of making a three-dimensional object, comprising:

(a) producing an intermediate three-dimensional object from the dual care resin of claim 1 by light polymerization of said dual cure resin by stereolithography;

(b) optionally cleaning said intermediate three-dimensional object; and then

(c) heating and/or microwave irradiating said intermediate three-dimensional object to produce a three-dimensional object.

9. The method of claim 8 , wherein said stereolithography is bottom-up stereolithography.

10. The method of claim 8 , wherein said stereolithography is continuous liquid interface production.

11. The method of claim 8 , said three-dimensional object having a heat deflection temperature of from 150° C to 300° C.

12. The method of claim 8 , said three-dimensional object having a Notched Izod Impact Strength of at least 40 J/m to 100 J/m.

13. The method of claim 8 , said three-dimensional object absorbing not more than 8 percent by weight of water after being immersed in deionized water at atmospheric pressure and a temperature of 85° C. for a time of eight days.

14. A three-dimensional object produced by the process of claim 8 .

15. The dual cure resin of claim 1 , wherein said cyanate ester resin comprises a bisphenol E or bisphenol A cyanate ester.

16. The dual cure resin of claim 1 , wherein R° is an n-valent radical of an elastomeric prepolymer after the removal of terminal isocyanate, amino or hydroxyl groups.

17. The dual cure resin of claim 4 , wherein the light polymerizable monomer comprises a urethane acrylate or methacrylate.