Methods and compositions to stabilize a nanogel and dental compositions therefrom

Patent metadata

Field	Value
Publication number	US-11110037-B2
Application number	US-201916554695-A
Country	US
Kind code	B2
Filing date	Aug 29, 2019
Priority date	Aug 29, 2018
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

The present disclosure relates to methods and compositions to stabilize a nanogel and use of such nanogel as additives in dental compositions.

First claim

The invention claimed is:

1. A dental composition comprising a nanogel formed by a process comprising the steps of:
(a) polymerizing by a thermal polymerization a mixture comprising
(i) at least one comonomer having one ethylenically unsaturated group,
(ii) at least one of a comonomer having two ethylenically unsaturated group and at least one comonomer having at least three ethylenically unsaturated groups,
(iii) at least one chain transfer agent, and
(iv) an initiator;
at a reaction temperature to obtain a nanogel solution; and

(b) terminating the polymerization by lowering the reaction temperature and quenching the nanogel solution with a radical scavenger; wherein the radical scavenger is present at a concentration such that nanogel solution has a thermal stability at storage for 7 days at 25° C.

2. The dental composition according to claim 1 , wherein the mixture further comprises a solvent.

3. The dental composition according to claim 1 , wherein radical scavenger is present in at least 0.1% wt/wt based on total weight of comonomers in the mixture.

4. The dental composition according to claim 1 , wherein the radical scavenger in step (b) is TEMPO, substituted TEMPO, polychlorinated triphenylmethyl radicals, phenalenyls, cyclopentadienyls, other carbon centered radicals, a nitroxide radical, di-tert-alkyliminoxyls, delocalized radicals containing a hydrazyl unit, metal-coordinated phenoxy radicals, stable radicals containing a thiazyl unit or stable radicals of a heavy p-block elements.

5. The dental composition according to claim 4 , wherein the radical scavenger is TEMPO.

6. The dental composition according to claim 1 , wherein the comonomer having one ethylenically unsaturated group is selected from the group consisting of C 1 -C 12 alkyl(meth)acrylates, a hydroxyl alkyl(meth)acrylates, allyl ethers, an aromatic (meth)acrylates, vinylether, vinylester, vinylamine, acrylamide, methacrylamide, hydroxyl alkyl acrylamide and hydroxyl alkyl methacrylamide.

7. The dental composition according to claim 1 , wherein the comonomer having two ethylenically unsaturated group comprises a compound of Formula I
X—R—Y  Formula I

wherein,
X is (meth)acryl or (meth)acrylamide moiety;
Y is (meth)acryl, methacrylamide, allyl, vinyl ether, vinyl ester, or vinyl amine moiety;
R is direct bond or an organic moiety;
wherein the organic moiety is an unsubstituted or substituted C 1 -C 18 alkylene, unsubstituted or substituted C 3 -C 8 cycloalkylene, unsubstituted or substituted aralkylene, unsubstituted or substituted C 1 -C 8 cycloalkylalkylene, unsubstituted or substituted C 5 -C 18 arylene or unsubstituted or substituted C 3 -C 18 heteroarylene; wherein each unsubstituted or substituted organic moiety may contain at least one of C 1 -C 4 alkylene, 1-4 urethane groups (—NH—(C═O)—O— or —O—(C═O)—NH—), 1-8 oxygen atoms or nitrogen atoms; wherein each substituted organic moiety is substituted with one or more substituent(s) selected from the group consisting of a alkyl, hydroxyl, a thiol group, —COOM, —PO 3 M, —O—PO 3 M 2 or —SO 3 M*; wherein M and M* are independent of each other and are hydrogen atom or metal.

8. The dental composition according to claim 1 , wherein the comonomer having at least three ethylenically unsaturated groups is selected from the group consisting of trimethylolpropane tri(meth)acrylate, pentaerythritol triacrylate, and pentaerythritol tetra-acrylate, dipentaerythritol hexaacrylate and N,N′-Bisacryloyl-N,N′-bisallyl-1,4-but-2-endiamine.

9. The dental composition according to claim 1 , wherein the comonomer includes at least one having at least three ethylenically unsaturated groups is present in a range of from 1 to 30 mole percent based on total moles of comonomers in the mixture.

10. The dental composition according to claim 1 , wherein the comonomer having one ethylenically unsaturated group is present in a range of from 50 to 95 mole percent based on total moles of comonomers in the mixture.

11. The dental composition according to claim 1 , wherein the comonomer having two ethylenically unsaturated group is present in a range of from 5 to 50 mole percent based on total moles of comonomers in the mixture.

12. The dental composition according to claim 1 , wherein the at least one chain transfer agent is RSH, wherein R is a linear or branched alkyl having from 3 to 20 carbon atoms.

13. The dental composition according to claim 1 , wherein the at least one chain transfer agent is present in a concentration of from 5 to 50% mol/mol based on total moles of comonomers in the mixture.

14. The dental composition according to claim 1 , wherein the initiator is selected from at least one of organic peroxides and azo compounds.

15. The dental composition according to claim 14 , wherein the initiator is selected from the group consisting of benzoyl peroxide, 2,2-azobis-(2-methylpropionitrile) and 2,2-azobis-(2-methylbutyronitrile).

16. The dental composition according to claim 1 , wherein the initiator is present in a concentration of from 0.5 to 5.0% wt/wt based on total based on total weight of comonomers in the mixture.

17. The dental composition according to claim 1 , wherein the nanogel is soluble in at least one solvent selected from the group consisting of methyl ethyl ketone, acetone and toluene.

18. The dental composition according to claim 1 , wherein the nanogel is present in concentration of from 5 to 40% wt/wt based on the total weight of the composition.

19. The dental composition according to claim 18 , further comprising
(i) at least one filler in a concentration of from 5 to 95% wt/wt based on the total weight of the composition,
(ii) at least one polymerization initiator in a concentration of from 0.05 to 5% wt/wt based on the total weight of the composition.

20. A nanogel formed by a process comprising the steps of:
(a) polymerizing by a thermal polymerization a mixture comprising:
(i) at least one comonomer having one ethylenically unsaturated group
(ii) at least one of a comonomer having two ethylenically unsaturated group and at least one comonomer having at least three ethylenically unsaturated groups
(iii) at least one chain transfer agent, and
(iv) an initiator;
at a reaction temperature to obtain a nanogel solution; and

(b) terminating the polymerization by lowering the reaction temperature and quenching the nanogel solution with a radical scavenger; wherein the radical scavenger is present at concentration such that nanogel solution has a thermal stability at storage for 7 days at 25° C.;
wherein the nanogel is essentially free of macrogel.

21. The nanogel according to claim 20 , wherein the nanogel has a hydrodynamic radius of from 2 nm to 20 nm.

22. A method of using the nanogel as defined in claim 20 , to prepare a dental composition, wherein the dental composition is a dental composite, dental adhesive, dental cements, resin-modified glass ionomers, vanish, sealant, denture materials, composite blocks, and composite inks for dental 3D printing.

23. A method of forming a nanogel, said method comprising:
(a) polymerizing by a thermal polymerization a mixture comprising:
(i) at least one comonomer having one ethylenically unsaturated group
(ii) at least one of a comonomer having two ethylenically unsaturated group and at least one comonomer having at least three ethylenically unsaturated groups
(iii) at least one chain transfer agent,
(iv) an initiator;
at a reaction temperature to obtai

Assignees

• Dentsply Sirona Inc

Inventors

• Jin Xiaoming
• Usta Bassam
• Scheufler Christian
• Klee Joachim E
• Tigges Thomas
• Neuhaus Kira
• Brenneisen Jörg
• Lu Hui

Classifications

• A61K6/887 Primary

  Compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• C08L33/14

  of esters containing halogen, nitrogen, sulfur, or oxygen atoms in addition to the carboxy oxygen · CPC title

• A61K6/17 Primary

  Particle size · CPC title

• A61K6/64

  Thermal radical initiators · CPC title