High magnesium surface concentration nanocalcite composites

Patent metadata

Field	Value
Publication number	US-10035909-B2
Application number	US-200913502836-A
Country	US
Kind code	B2
Filing date	Dec 17, 2009
Priority date	Dec 17, 2009
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

Compositions comprising surface-modified calcite nanoparticles dispersed in a curable resin and to coatings and fibrous composites incorporating such compositions are described. The nanocalcite particles have a high magnesium to calcium surface concentration ratio. The surface-modifying agents include a binding group ionically associated with the nanoparticles, and a compatiblizing segment compatible with the curable resin. The surface-modifying agent may also include a reactive group capable of reacting with the curable resin. Methods of preparing nanocalcite composites, and coatings and fibrous composites prepared from such nanocalcite composites are also described.

First claim

What is claimed is:

1. A composition comprising surface-modified nanoparticles dispersed in a curable resin which is a curable epoxy resin, wherein the surface-modified nanoparticles comprise calcite cores having a magnesium 24 isotope to calcium 44 isotope surface concentration ratio of greater than 1 as measured according to the TOF-SIMS Test Procedure, and a first surface-modifying agent according to the formula:
Compatiblizing Segment−Binding Group

or the formula:
Compatiblizing Segment−Linking Group−Binding Group

the first surface-modifying agent comprising a binding group ionically bonded to the nanoparticle and a compatiblizing segment compatible with the curable resin; wherein at least 70%, of the calcite cores have an average size of less than 400 nm as measured by the Calcite Particle Size Procedure.

2. The composition of claim 1 , wherein the magnesium 24 isotope to calcium 44 isotope surface concentration ratio is greater than 4 as measured according to the TOF-SIMS Test Procedure.

3. The composition of claim 2 , wherein the magnesium 24 isotope to calcium 44 isotope surface concentration ratio is greater than 10 as measured according to the TOF-SIMS Test Procedure.

4. The composition according claim 1 , wherein the difference between the solubility parameter of the curable resin and the solubility parameter of the compatiblizing group, as determined according to the Solubility Parameter Procedure, is no greater than 4 J 1/2 cm −3/2 .

5. The composition according to claim 1 , wherein the binding group has a binding energy of at least 1.0 electron volts to calcite as calculated using the Binding Energy Calculation Procedure assuming a stoichiometric surface.

6. The composition according to claim 1 , wherein at least 90%, of the calcite cores have an average size of less than 400 nm as measured by the Calcite Particle Size Procedure.

7. The composition according to claim 1 , wherein at least 70% the calcite cores have an aspect ratio of greater than 1.5.

8. The composition according to claim 1 , wherein the surface-modified nanoparticles further comprise a ligand-rich shell surrounding the calcite core.

9. The composition according to claim 1 , wherein the first surface-modifying agent further comprises a reactive group capable of reacting with the curable resin.

10. The composition according to claim 1 , further comprising a second surface-modifying agent bonded to the calcite, wherein the second surface-modifying agent comprises a binding group and a reactive group capable of reacting with the curable resin.

11. The composition according to claim 1 , wherein the composition comprises at least 10 wt. % nanoparticles based on the total weight of the nanoparticles and the curable resin.

12. The composition according to claim 1 , wherein the composition comprises no greater than 2 wt. % solvent.

13. A cured composition comprising the composition according to claim 1 , wherein the curable resin is cured.

14. A coated article comprising a substrate and the cured composition of claim 13 bonded to at least a portion of the substrate.

15. A fibrous composite comprising the composition according to claim 1 and reinforcing fibers, wherein the reinforcing fibers are impregnated with the composition.

16. The fibrous composite of claim 15 , wherein the curable resin is cured.

17. A method of making a composition comprising (i) selecting a calcite having a magnesium 24 isotope to calcium 44 isotope surface concentration ratio of greater than 4 as measured according to the TOF-SIMS Test Procedure, (ii) milling the calcite until greater than 90% of the calcite has an average size of less than 400 nm as measured by the Calcite Particle Size Procedure, (iii) ionically bonding a binding group of a first surface modifying agent according to the formula:
Compatiblizing Segment−Binding Group

or the formula:
Compatiblizing Segment−Linking Group−Binding Group

to the calcite, wherein the binding group has a binding energy of at least 1.0 electron volts to calcite as calculated using the Binding Energy Calculation Procedure assuming a stoichiometric surface; and (iv) dispersing the surface-modified calcite in a curable resin which is a curable epoxy resin to form a dispersion, wherein the difference between the solubility parameter of the curable resin and the solubility parameter of a compatiblizing group of the first surface modifying agent, as determined according to the Solubility Parameter Procedure, is no greater than 4 J 1/2 cm −3/2 .

18. The method of claim of claim 17 , further comprising (v) at least one of (a) impregnating fibers with the dispersion and (b) applying the dispersion to a substrate; and (vi) curing the curable resin.

19. The composition of claim 1 wherein the compatiblizing segment is selected from the group consisting of polyalkylene oxides, polyesters and polyether amines.

20. The composition of claim 1 wherein the compatiblizing segment is selected from the group consisting of polyalkylene oxides.

21. The composition of claim 1 wherein the binding group is a sulfonic acid group.

22. The composition of claim 19 wherein the binding group is a sulfonic acid group.

23. The composition of claim 20 wherein the binding group is a sulfonic acid group.

24. The method of claim 17 wherein the compatiblizing segment is selected from the group consisting of polyalkylene oxides, polyesters and polyether amines.

25. The method of claim 17 wherein the compatiblizing segment is selected from the group consisting of polyalkylene oxides.

26. The method of claim 17 wherein the binding group is a sulfonic acid group.

27. The method of claim 24 wherein the binding group is a sulfonic acid group.

28. The method of claim 25 wherein the binding group is a sulfonic acid group.

Assignees

• Schultz William J
• Buckett Mary I
• Condo Peter D
• Goetz Douglas P
• Haraldson Chad A
• Mccormick Mark
• Thompson Wendy L
• Pachuta Steven J
• 3M Innovative Properties Co

Inventors

• Schultz William J
• Buckett Mary I
• Condo Peter D
• Goetz Douglas P
• Haraldson Chad A
• Mccormick Mark
• Thompson Wendy L
• Pachuta Steven J

Classifications

• C08K2003/265

  Calcium, strontium or barium carbonate · CPC title

• C08K3/26 Primary

  Carbonates; Bicarbonates · CPC title

• C08K9/04

  Ingredients treated with organic substances {(treated with macromolecular compounds C08K9/08)} · CPC title

• C08L63/00 Primary

  Compositions of epoxy resins; Compositions of derivatives of epoxy resins · CPC title

• C08K5/42

  Sulfonic acids; Derivatives thereof · CPC title