Elongated abrasive particles, method of making the same, and abrasive articles containing the same

Patent metadata

Field	Value
Publication number	US-11274237-B2
Application number	US-201816649031-A
Country	US
Kind code	B2
Filing date	Sep 14, 2018
Priority date	Oct 2, 2017
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

A method of making elongated abrasive particles includes five steps. Step 1) includes providing a mold having parallel linear grooves, partially interrupted at predetermined intervals by transverse obstructions. Step 2) includes filling the parallel linear grooves with a flowable abrasive particle precursor composition. Step 3) includes at least partially drying the flowable abrasive particle precursor composition to form an at least partially dried abrasive particle precursor composition. Step 4) includes separating that composition from the mold, thereby forming elongated precursor abrasive particles having a shape corresponding to portions of the parallel linear grooves disposed between the transverse obstructions. At least one of the first and second opposite ends of the elongated precursor abrasive particles comprises both a molded portion and a fractured portion. Step 5) converts the elongated precursor abrasive particles into elongated abrasive particles. Elongated abrasive particles preparable by the method and abrasive articles containing them are also disclosed.

First claim

What is claimed is:

1. A method of making elongated abrasive particles, the method comprising:
providing a mold having parallel linear grooves, wherein the parallel linear grooves are partially interrupted at predetermined intervals by transverse obstructions;
filling at least a portion of the parallel linear grooves with a flowable abrasive particle precursor composition, wherein the flowable abrasive particle precursor composition is confined within at least one of the parallel linear grooves;
at least partially drying the flowable abrasive particle precursor composition to form an at least partially dried abrasive particle precursor composition;
separating the at least partially dried abrasive particle precursor composition from the mold, thereby forming elongated precursor abrasive particles having a shape corresponding to portions of the parallel linear grooves disposed between the transverse obstructions, wherein the predetermined intervals correspond to lengths of the elongated precursor abrasive particles, and wherein at least one of the first and second opposite ends of the elongated precursor abrasive particles comprises both a molded portion and a fractured portion; and
converting the elongated precursor abrasive particles into the elongated abrasive particles.

2. The method of claim 1 , wherein the parallel linear grooves that are at least partially defined by at least two planar surfaces, and wherein the parallel linear grooves are partially interrupted at predetermined intervals by transverse obstructions extending from at least one of the at least two planar surfaces.

3. The method of claim 1 , wherein said converting comprises sintering.

4. The method of claim 1 , wherein said converting comprises calcining and sintering.

5. The method of claim 1 , wherein each of the parallel linear grooves is at least partially defined by two planar surfaces.

6. The method of claim 1 , wherein each of the parallel linear grooves is defined by two planar surfaces.

7. The method of claim 1 , wherein both of the first and second opposite ends of the elongated abrasive particles comprise both a molded portion and a fractured portion.

8. The method of claim 1 , wherein the fractured portions comprise projections.

9. The method of claim 1 , wherein the elongated abrasive particles comprise alpha alumina.

10. The method of claim 1 , wherein the flowable abrasive particle precursor composition comprises a boehmite dispersion.

11. The method of claim 1 , wherein the transverse obstructions are bifurcated.

12. Elongated abrasive particles comprising a ceramic body bounded by at least two longitudinally-oriented contiguous surfaces, and first and second ends separated by the at least two longitudinally-oriented surfaces, wherein at least one of the first and second ends comprises both a molded portion and a fractured portion.

13. The elongated abrasive particles of claim 12 , wherein the elongated abrasive particles comprise alpha alumina.

14. The elongated abrasive particles of claim 12 , wherein the at least two longitudinally-oriented contiguous surfaces comprise three or four longitudinally-oriented surfaces.

15. The elongated abrasive particles of claim 12 , wherein the elongated abrasive particles have a substantially triangular or trapezoidal transverse cross-section.

16. The elongated abrasive particles of claim 12 , wherein both of the first and second opposite ends of the elongated abrasive particles comprise both a molded portion and a fractured portion.

17. The elongated abrasive particles of claim 12 , wherein the fractured portions comprise projections.

18. The elongated abrasive particles of claim 12 , wherein elongated abrasive particles conform to an abrasives industry specified nominal grade.

Assignees

• 3M Innovative Properties Co

Inventors

• Erickson Dwight D
• Adefris Negus B

Classifications

• C09K3/1418 Primary

  obtained by division of a mass agglomerated by sintering · CPC title

• C09K3/1409 Primary

  Abrasive particles per se (preparation of diamond C01B32/25) · CPC title

• C09K3/1427 Primary

  obtained by division of a mass agglomerated by melting, at least partially, e.g. with a binder · CPC title