Sol-gel compositions with improved hardness and impact resistance

1. A composition for forming a hybrid sol-gel coating comprising:

at least one organoalkoxysilane monomer of the formula:

R x Si(OR′) 4−x

wherein:

R is one or more moieties chosen independently from linear, branched, or cyclic alkyl and aryl;

R′ is methyl, ethyl, propyl or alkyl; and

x is at least 0 and less than 4;

a catalyst;

colloidal silica;

water; and

at least one organic polymer in the form of polymer particles having a median diameter D50 between 1 and 50 microns, wherein the organic polymer is selected from the group consisting of: polyphenylene sulfide (PPS); polyethersulfone (PES), polyether ether ketone (PEEK); polyphenylsulfone (PPSU); polyamide-imide (PAI); polyetherimide (PEI), and combinations of the foregoing, and further comprises at least one of the following:

a melt point of 200° C. or greater as determined by differential scanning calorimetry (DSC);

a glass transition temperature of 200° C. or greater as determined by differential scanning calorimetry (DSC); and

a heat deflection/distortion of 200° C. or greater, as determined by ASTM D648; and

a filler material other than the colloidal silica;

wherein the at least one organoalkoxysilane monomer, the catalyst, the colloidal silica, the water, the at least one organic polymer, and the filler are in admixture.

2. The composition of claim 1 , wherein the organic polymer comprises 2 wt. % to 50 wt. % of the composition on a total dry weight basis.

3. The composition of claim 1 , wherein the organic polymer comprises polyphenylene sulfide (PPS).

4. The composition of claim 1 , wherein, based on the total amount of the composition on a wet basis:

the at least one organoalkoxysilane monomer is present in an amount of 20 to 40 wt. %; and

the at least one organic polymer is present in an amount of 1.75 to 15 wt. %.

5. The composition of claim 1 , wherein the organic polymer is polyphenylene sulfide (PPS) present in an amount of 1 wt. % to 25 wt. % based on the total weight of the composition.

6. The composition of claim 5 , wherein the filler material comprises silicon carbide present in an amount of 1 wt. % to 5 wt. % based on a total weight of the composition.

7. The composition of claim 1 , wherein the organic polymer is polyether ether ketone (PEEK) present in an amount of 1 wt. % to 25 wt. % based on the total weight of the composition.

8. The composition of claim 1 , wherein the colloidal silica is present in an amount of 1 wt. % to 50 wt. %, based on a total weight of the composition.

9. The composition of claim 1 , wherein the colloidal silica is present in an amount of 10 wt. % to 45 wt. %, based on a total weight of the composition.

10. A composition for forming a hybrid sol-gel coating comprising:

at least one organoalkoxysilane monomer of the formula:

R x Si(OR′) 4−x

wherein:

R is one or more moieties chosen independently from linear, branched, or cyclic alkyl and aryl;

R′ is methyl, ethyl, propyl or alkyl; and

x is at least 0 and less than 4;

a catalyst;

water; and

at least one organic polymer in the form of polymer particles having a median diameter D50 between 1 and 50 microns, wherein the organic polymer comprises polyphenylene sulfide (PPS) and further comprises at least one of the following:

a melt point of 200° C. or greater as determined by differential scanning calorimetry (DSC);

a glass transition temperature of 200° C. greater as determined by differential scanning calorimetry (DSC); and

a heat deflection/distortion temperature of 200° C. or greater, as determined by ASTM D648;

a filler material;

wherein the at least one organoalkoxysilane monomer, the catalyst, the water, the at least one organic polymer, and the filler are in admixture; and

wherein the filler material comprises silicon carbide present in an amount of 1 wt. % and to 5 wt. % based on a total weight of the composition.

11. A method of forming a coating comprising:

providing a mixture, wherein the mixture comprises at least one organoalkoxysilane monomer of the formula:

R x Si(OR′) 4−x

wherein:

R is one or more moieties chosen independently from linear, branched, or cyclic alkyl and aryl;

R′ is methyl, ethyl, propyl or alkyl; and

x is at least 0 and less than 4;

a catalyst;

colloidal silica;

water; and

an organic polymer in the form of polymer particles having a median diameter D50 between 1 and 50 microns, wherein the organic polymer is selected from the group consisting of: polyphenylene sulfide (PPS); polyethersulfone (PES), polyether ether ketone (PEEK); polyphenylsulfone (PPSU); polyamide-imide (PAI); polyetherimide (PEI), and combinations of the foregoing, and further comprises at least one of the following:

a melt point of 200° C. or greater as determined by differential scanning calorimetry (DSC);

a glass transition temperature of 200° C. or greater as determined by differential scanning calorimetry (DSC); and

a heat deflection/distortion temperature of 200° C. or greater, as determined by ASTM D648;

applying the mixture to a substrate; and

curing the mixture to produce a hybrid sol-gel coating, wherein the at least one organosiloxane monomer polymerizes around the organic polymer to form a siloxane matrix with an organic polymer filler phase present as a separate phase from the siloxane matrix, and wherein the organic polymer is present in discrete portions interspersed within, and throughout, the void spaces in the siloxane matrix.

12. The method of claim 11 , further comprising hydrolysing the at least one organoalkoxysilane monomer with the catalyst before applying the mixture to the substrate.

13. The method of claim 11 , wherein the organic polymer is polyphenylene sulfide (PPS) present in an amount of 1 wt. % to 25 wt. % based on the total weight of the mixture.

14. The method of claim 11 , wherein the organic polymer is polyether ether ketone (PEEK) present in an amount of 1 wt. % to 25 wt. % based on the total weight of the mixture.

15. The method of claim 11 , wherein the colloidal silica is present in an amount of 1 wt. % to 50 wt. %, based on a total weight of the mixture.

16. The method of claim 11 , wherein the colloidal silica is present in an amount of 10 wt % to 45 wt. %, based on a total weight of the mixture.

17. A method of forming a coating comprising:

providing a mixture, wherein the mixture comprises at least one organoalkoxysilane monomer of the formula:

R x Si(OR′) 4−x

wherein:

R is one or more moieties chosen independently from linear, branched, or cyclic alkyl and aryl;

R′ is methyl, ethyl, propyl or alkyl; and

x is at least 0 and less than 4;

a catalyst;

water; and

an organic polymer in the form of polymer particles having a median diameter D50 between 1 and 50 microns, wherein the organic polymer comprises polyphenylene sulfide (PPS) present in an amount of 1 wt. % to 25 wt. % based on the total weight of the mixture and further comprises at least one of the following:

a melt point of 200° C. or greater as determined by differential scanning calorimetry (DSC);

a glass transition temperature of 200° C. or greater as determined by differential scanning calorimetry (DSC); and

a heat deflection distortion temperature of 200° C. or greater, as determined by ASTM D648;

applying the mixture to a substrate; and

curing the mixture to produce a hybrid sol-gel coating, wherein the at least one organosiloxane monomer polymerizes around the organic polymer to form a siloxane matrix with an organic polymer filler phase present as a separate phase from the siloxane matrix, and wherein the organic polymer is present in discrete portions interspersed within, and throughout the void spaces in the siloxane matrix; and

further comprising a filler material in the form of silicon carbide present in an amount of 1 wt. % to 5 wt. % based on a total weight of the composition.

18. The composition of claim 1 , wherein x=0.

19. The composition of claim 1 , wherein x=1.

20. The composition of claim 10 , wherein x=0.

21. The composition of claim 10 , wherein x=1.

22. The method of claim 11 , wherein x=0.

23. The method of claim 11 , wherein x=1.

24. The method of claim 11 , wherein the substrate is an article of cookware.

25. The method of claim 17 , wherein x=0.

26. The method of claim 17 , wherein x=1.

27. The method of claim 17 , wherein the substrate is an article of cookware.