Orthodontic articles comprising polymerized composition comprising at least two free-radical initiators

Patent metadata

Field	Value
Publication number	US-11904031-B2
Application number	US-201816754186-A
Country	US
Kind code	B2
Filing date	Nov 20, 2018
Priority date	Nov 22, 2017
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

An orthodontic article is described comprising the reaction product of a free-radically polymerizable resin; a first free-radical photoinitiator having sufficient absorbance at a first wavelength range; and a second free-radical initiator selected from a second photoinitiator having sufficient absorbance at a second wavelength range, wherein the second wavelength range is different than the first wavelength range, or a thermal free-radical initiator. In some embodiments, the first free-radical photoinitiator exhibits a maximum absorbance at a wavelength of the range of 370-380 nm or 320-330 nm and/or comprises photoinitiator groups selected from acyl phosphine oxide or alkyl amine acetophenone. Also described are photopolymerizable compositions and methods.

First claim

What is claimed is:

1. An orthodontic article comprising a cured composition comprising
a free-radically polymerizable resin comprising a urethane (meth)acrylate comprising polymerized units derived from a diol selected from polycarbonate diol or polyester diol;
a first free-radical photoinitiator having sufficient absorbance at a first wavelength range; and
a second free-radical initiator selected from a second photoinitiator having sufficient absorbance at a second wavelength range, wherein the second wavelength range is different than the first wavelength range, or a thermal free-radical initiator.

2. The orthodontic article of claim 1 wherein a 1 g/liter acetonitrile solution of the first free-radical photoinitiator, at a pathlength of 1 cm, has an absorbance of greater than 0.01 at a wavelength of 385 nm when measured with a spectrophotometer.

3. The orthodontic article of claim 1 wherein a 1 g/liter acetonitrile solution of the first free-radical photoinitiator, at a pathlength, of 1 cm has an absorbance of greater than 0.2 for a 1 g/liter solution of the first free-radical photoinitiator in acetonitrile at a wavelength of 385 nm when measured with a spectrophotometer.

4. The orthodontic article of claim 1 wherein the first free-radical photoinitiator has a maximum absorbance at a wavelength of the range of 370-380 nm or 320-330 nm.

5. The orthodontic article of claim 1 wherein the first free-radical photoinitiator comprises photoinitiator groups selected from acyl phosphine oxide or alkyl amine acetophenone.

6. The orthodontic article of claim 1 wherein the second free-radical initiator is a thermal initiator.

7. The orthodontic article of claim 1 wherein a 1 g/liter acetonitrile solution of the second photoinitiator, at a pathlength of 1 cm, has an absorbance of greater than 0.01 at a wavelength of 365 nm when measured with a spectrophotometer.

8. The orthodontic article of claim 1 wherein the second photoinitiator has a maximum absorbance at a wavelength of the range 325-330 nm.

9. The orthodontic article of claim 1 wherein the second photoinitiator comprises photoinitiator groups selected from benzil ketal or hydroxy-acetophenone.

10. The orthodontic article of claim 1 wherein a 1 g/liter acetonitrile solution of the second photoinitiator, at a pathlength of 1 cm, has an absorbance of less than 0.1 at a wavelength of 365 nm.

11. The orthodontic article of claim 1 wherein the composition comprises 0.1 to 5 wt. % of photoinitiators based on the total weight of the polymerizable composition.

12. The orthodontic article of claim 1 wherein the polymerizable composition further comprises an ultraviolet absorber.

13. The orthodontic article of claim 1 wherein the free-radically polymerizable resin comprises 25 to 70 wt. % of at least one monofunctional reactive diluent.

14. The orthodontic article of claim 13 wherein the monofunctional reactive diluent comprises at least one monofunctional reactive diluent having a T g of 25 degrees Celsius or greater.

15. The orthodontic article of claim 13 wherein the monofunctional reactive diluent comprises at least one monofunctional reactive diluent where a homopolymer thereof has a T g of 60 degrees Celsius or greater.

16. The orthodontic article of claim 13 wherein the monofunctional reactive diluent comprises at least one monofunctional reactive diluent having a log P value of greater than 1.5.

17. The orthodontic article of claim 13 wherein the orthodontic article comprises less than 0.1 wt.-% extractables in a solution of 5% ethanol in water.

18. The orthodontic article of claim 1 wherein the cured composition exhibits an elongation at break of 15% or greater and a tensile strength at yield of at least 10 MPa as determined according to ASTM D638-14 after conditioning in phosphate-buffered saline having a pH of 7.4 for 24 hours at a temperature of 37° C.

19. The orthodontic article of claim 1 wherein the cured composition polymerized composition exhibits a 3-point bend modulus of at least 100 MPa as determined according to dynamic mechanical analysis at 2% strain after conditioning in deionized water at 20-25° C. for 48 hours.

20. The orthodontic article of claim 1 wherein the orthodontic article is orthodontic tray aligner article.

Assignees

• 3M Innovative Properties Company

Inventors

• Chakraborty Saswata
• Macmurray Benjamin C
• Nelson Eric W
• Klun Thomas P
• Pokorny Richard J
• Mahoney Wayne S
• Amb Chad M
• Griesgraber George W
• Reed Dana R
• Abuelyaman Ahmed S
• Clough Robert S
• Hansen James D
• Skamser Daniel J
• Dailey Ian
• Riedesel John M

Classifications

• A61K6/62 Primary

  Photochemical radical initiators · CPC title

• A61C7/002

  Orthodontic computer assisted systems · CPC title

• A61C7/08

  Mouthpiece-type retainers {or positioners, e.g. for both the lower and upper arch (arch-shaped medicament applicators for teeth or gums A61C19/063; mouthguards for protecting the teeth of sportsmen A63B71/085)} · CPC title

• A61K6/893

  Polyurethanes · CPC title

• B29C64/124

  using layers of liquid which are selectively solidified · CPC title