Shaped abrasive particles with low roundness factor

Patent metadata

Field	Value
Publication number	US-10137556-B2
Application number	US-57006709-A
Country	US
Kind code	B2
Filing date	Sep 30, 2009
Priority date	Jun 22, 2009
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

Shaped abrasive particles comprising alpha alumina and having a cross-sectional shape along a longitudinal axis of the shaped abrasive particles, the cross-sectional shape comprising a non-circular cross-sectional plane, and the shaped abrasive particles comprise an Average Roundness Factor of between about 15% to 0%.

First claim

What is claimed is:

1. Shaped abrasive particles comprising alpha alumina made from a dispersion of aluminum oxide monohydrate and having a cross-sectional shape along a longitudinal axis of the shaped abrasive particles, the cross-sectional shape comprising a noncircular cross-sectional plane, the shaped abrasive particles comprising an Average Roundness Factor of between about 15% to 0% for the transverse cut, C, of the cross-sectional shape along the longitudinal axis, the shaped abrasive particles comprising an average tip radius of a cross-section of a first and a second face separated by a thickness t ranging from about 25 μm to about 500 μm and the average tip radius is less than 75 microns, and wherein the shaped abrasive particles exhibit a better cut rate during grinding than corresponding shaped abrasive particles having a higher Average Roundness Factor.

2. The shaped abrasive particles of claim 1 comprising
the first face and the second face connected to each other by a sidewall; and
a draft angle a is defined between the second face and the sidewall.

3. The shaped abrasive particles of claim 2 wherein a perimeter of the first face and the second face comprises a substantially triangular shape.

4. The shaped abrasive particles of claim 1 , 2 , or 3 wherein the cross-sectional shape comprises a rectangle.

5. The shaped abrasive particles of claim 1 , 2 , or 3 wherein the cross-sectional shape comprises a trapezoid.

6. The shaped abrasive particles of claim 5 wherein the draft angle a is between about 95 degrees to about 130 degrees.

7. The shaped abrasive particles of claim 1 comprising a volumetric aspect ratio and the volumetric aspect ratio is greater than about 1.15.

8. The shaped abrasive particles of claim 1 , 2 , 3 , or 7 wherein the Average Roundness Factor is between about 12% to about 5%.

9. The shaped abrasive particles of claim 1 comprising a binder forming an abrasive article selected from the group consisting of bonded abrasive articles, coated abrasive articles, nonwoven abrasive articles, and abrasive brushes.

10. A coated abrasive article comprising the shaped abrasive particles of claim 1 , 2 , 3 , or 7 and a make coat on a first major surface of a backing and a majority of the shaped abrasive particles adhered to the make coat by the sidewall, the shaped abrasive particles forming an abrasive layer, the abrasive layer coated with a size coat, wherein the abrasive layer comprises at least 5 percent by weight of the shaped abrasive particles, and wherein the coated abrasive article exhibits a better cut rate during grinding than a corresponding coated abrasive article having shaped abrasive particles having a higher Average Roundness Factor greater than about 15%.

11. The coated abrasive article of claim 10 wherein a majority of the shaped abrasive particles are adhered to the make coat by the sidewall, and have an orientation angle β between about 50 degrees to about 85 degrees.

12. The coated abrasive article of claim 11 wherein the abrasive layer is an open coat abrasive layer and a percent open area in the abrasive layer is between about 40% to about 70%.

13. The coated abrasive article of claim 12 wherein the abrasive layer comprises 100% by weight of the shaped abrasive particles.

14. The coated abrasive article of claim 12 wherein the orientation angle β is between about 70 degrees to about 85 degrees.

15. A coated abrasive article comprising:
shaped abrasive particles comprising
alpha alumina made from a dispersion of aluminum oxide monohydrate and having a cross-sectional shape along a longitudinal axis of the shaped abrasive particles,
the cross-sectional shape comprising a noncircular cross-sectional plane,
the shaped abrasive particles comprising an Average Roundness Factor of between about 15% to 0% for the transverse cut, C, of the cross-sectional shape along the longitudinal axis,
the shaped abrasive particles comprising an average tip radius of a cross-section of the first or second face and the average tip radius of less than 75 microns and a thickness t ranging from about 25 μm to about 500 μm;
a make coat on a first major surface of a backing with a majority of the shaped abrasive particles adhered to the make coat by the sidewall, the shaped abrasive particles forming an abrasive layer, wherein the abrasive layer comprises at least 5 percent by weight of the shaped abrasive particles; and
a size coat coated on the abrasive layer;
wherein the coated abrasive article exhibits a better cut rate during grinding than a corresponding coated abrasive article having shaped abrasive particles having a higher Average Roundness Factor greater than about 15%.

16. The coated abrasive article of claim 15 , wherein the abrasive layer is an open coat abrasive layer and a percent open area in the abrasive layer is between about 40% to about 70%.

17. The coated abrasive article of claim 15 , wherein the abrasive layer comprises 100% by weight of the shaped abrasive particles.

18. The coated abrasive article of claim 15 , wherein a majority of the shaped abrasive particles are adhered to the make coat by the sidewall, and have an orientation angle β between about 50 degrees to about 85 degrees.

19. The coated abrasive article of claim 15 , wherein the make coat and the size coat independently comprise a binder.

20. The shaped abrasive particles of claim 2 , wherein the draft angle α is about 90 degrees.

Assignees

• Erickson Dwight D
• 3M Innovative Properties Co

Inventors

• Erickson Dwight D

Classifications

• C04B2235/3217

  Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina · CPC title

• C01P2004/02

  obtained by optical microscopy · CPC title

• Y10T428/2982

  Particulate matter [e.g., sphere, flake, etc.] · CPC title

• C01F7/02

  Aluminium oxide; Aluminium hydroxide; Aluminates · CPC title

• C04B35/1115

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