Abrasive particles, abrasive articles, and methods of making and using the same

Patent metadata

Field	Value
Publication number	US-10155892-B2
Application number	US-201515121968-A
Country	US
Kind code	B2
Filing date	Feb 13, 2015
Priority date	Feb 27, 2014
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

Abrasive particles include: 0.50 to 5.00 weight percent of seed particles for alpha-alumina formation selected from the group consisting of alpha-Fe 2 O 3 seed particles, alpha-Al 2 O 3 seed particles, and combinations thereof; 0.50 to 5.00 weight percent of MgO; 0.02 to 0.40 weight percent of Li 2 O or a molar equivalent amount of at least one alkali metal oxide selected from the group consisting of: Na 2 O; K 2 O; combinations of Na 2 O and Li 2 O; combinations of K 2 O and Li 2 O; combinations of Na 2 O and K 2 O; and combinations of Li 2 O, Na 2 O, and K 2 O; and 91.08 to 99.48 weight percent of Al 2 O 3 . Methods of making the abrasive particles and abrasive articles incorporating them are also disclosed.

First claim

What is claimed is:

1. Abrasive particles, wherein the abrasive particles comprise the components:
a) 0.50 to 5.00 weight percent of seed particles for alpha-alumina formation selected from the group consisting of alpha-Fe 2 O 3 seed particles, alpha-Al 2 O 3 seed particles, and combinations thereof;
b) 0.50 to 5.00 weight percent of MgO;
c) 0.02 to 0.40 weight percent of Li 2 O or a molar equivalent amount of at least one alkali metal oxide selected from the group consisting of: Na 2 O; K 2 O; combinations of Na 2 O and Li 2 O; combinations of K 2 O and Li 2 O; combinations of Na 2 O and K 2 O; and combinations of Li 2 O, Na 2 O, and K 2 O; and
d) 91.08 to 99.48 weight percent of Al 2 O 3 ,

wherein component c) comprises 0.05 to 1.00 weight percent of K 2 O.

2. Abrasive particles according to claim 1 , wherein the abrasive particles consist of components a), b), c), and d).

3. Abrasive particles according to claim 1 , wherein the abrasive particles comprise an alpha-alumina crystalline phase and from 0.25 to 20 percent by weight of a beta-alumina crystalline phase.

4. Abrasive particles according to claim 1 , wherein the abrasive particles comprise less than 10 percent by weight of magnetoplumbite crystalline phases.

5. A method of abrading a workpiece, the method comprising:
frictionally contacting abrasive particles according to claim 1 with a surface of the workpiece, and
moving at least one of the abrasive particles and the surface of the workpiece relative to the other to abrade at least a portion of the surface of the workpiece.

6. An abrasive article comprising abrasive particles according to claim 1 retained in a binder material.

7. An abrasive article according to claim 6 , wherein the binder material is disposed on a substrate.

8. An abrasive article according to claim 7 , wherein the abrasive article comprises an abrasive layer comprising the abrasive particles and the binder material secured to a major surface of a backing, and wherein the abrasive layer comprises a make coat and a size coat.

9. An abrasive article according to claim 7 , wherein the abrasive article comprises an abrasive layer comprising the abrasive particles and the binder material secured to a major surface of a backing, and wherein the abrasive layer comprises a plurality of shaped abrasive composites.

10. An abrasive article according to claim 7 , wherein the substrate comprises a lofty open nonwoven fiber web.

11. An abrasive article according to claim 6 , wherein the abrasive article comprises a bonded abrasive article.

12. A method of making abrasive particles, the method comprising:
i) providing a dispersion comprising:
an alpha-alumina precursor;
alkali metal cations selected from the group consisting of Li + , Na + , K + , and combinations thereof;
magnesium oxide or a precursor thereof; and
seed particles selected from the group consisting of alpha-Fe 2 O 3 seed particles and alpha-Al 2 O 3 seed particles, or a precursor thereof, wherein the seed particles facilitate conversion of the alumina precursor material to alpha-alumina upon sintering;

ii) converting the dispersion to abrasive precursor particles; and
iii) sintering the abrasive precursor particles to provide the abrasive particles, wherein the abrasive particles comprise the components:
a) 0.50 to 5.00 weight percent of the seed particles;
b) 0.50 to 5.00 weight percent of MgO;
c) 0.02 to 0.40 weight percent of Li 2 O or a molar equivalent amount of at least one alkali metal oxide selected from the group consisting of: Na 2 O; K 2 O; combinations of Na 2 O and Li 2 O; combinations of K 2 O and Li 2 O; combinations of Na 2 O and K 2 O; and combinations of Li 2 O, Na 2 O, and K 2 O; and
d) 91.08 to 99.48 weight percent of Al 2 O 3 ,

wherein component c) comprises 0.05 to 1.00 weight percent of K 2 O.

13. A method according to claim 12 , wherein the abrasive particles consist of components a), b), c), and d).

14. A method according to claim 12 , wherein the abrasive particles comprise an alpha-alumina crystalline phase and from 0.25 to 20 percent by weight of a beta-alumina crystalline phase, based on the total weight of the alpha-alumina crystalline phase and the beta-alumina crystalline phase combined.

15. A method according to claim 12 , wherein each of the abrasive particles comprises less than 10 percent by weight of magnetoplumbite crystalline phases.

16. A method according to claim 12 , wherein said converting the dispersion to the abrasive precursor particles comprises a drying step followed by a calcining step.

Assignees

• 3M Innovative Properties Co

Inventors

• Monroe Larry D
• Greske Grant E

Classifications

• C04B35/1115

  Minute sintered entities, e.g. sintered abrasive grains or shaped particles such as platelets (abrasives C09K3/14) · CPC title

• C04B2235/3272

  Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite · CPC title

• B24D11/00

  Constructional features of flexible abrasive materials; Special features in the manufacture of such materials · CPC title

• C04B2235/3206

  Magnesium oxides or oxide-forming salts thereof · CPC title

• C04B2235/80

  Phases present in the sintered or melt-cast ceramic products other than the main phase · CPC title