Magnetizable abrasive particle and method of making the same

Patent metadata

Field	Value
Publication number	US-2020071584-A1
Application number	US-201716338756-A
Country	US
Kind code	A1
Filing date	Oct 24, 2017
Priority date	Oct 25, 2016
Publication date	Mar 5, 2020
Grant date	—

Abstract

Magnetizable abrasive particles are described comprising ceramic particles having outer surfaces comprising a coating of unsintered polyion and magnetic particles bonded to the polyion. In favored embodiments, the magnetic particles have a magnetic saturation of at least 10, 15, 20, 25, 30, 35, 40, 45 or 50 emu/gram. In another embodiment, an abrasive article is described comprising a plurality of magnetizable abrasive particles as described herein retained in a binder material. Also described are method of making magnetizable abrasive particles and methods of making an abrasive article comprising magnetizable abrasive particles.

First claim

1 . A method of making magnetizable abrasive particles, the method comprising steps:
a) providing ceramic particles, each ceramic particle having a respective outer surface; b) coating the outer surfaces of ceramic particles with an aqueous solution comprising a polyionic material thereby forming polyion-coated ceramic particles; and c) combining the polyion-coated ceramic particles with magnetic particles while dispersed in an aqueous solution thereby forming magnetic particle-coated ceramic particles; d) drying the magnetic particle-coated ceramic particles in the absence of sintering the polyion.

2 . The method of claim 1 wherein after drying the magnetic particle-coated ceramic particles have less than 25% agglomerated magnetic particle-coated ceramic particles.

3 . The method of claim 1 wherein the magnetic particles have a magnetic saturation of at least 10, 15, 20, 25, 30, 35, 40, 45 or 50 emu/gram.

4 . Magnetizable abrasive particles prepared according to claim 1 .

5 . The magnetizable abrasive particles of claim 4 , wherein the magnetizable abrasive particles conform to an abrasives industry specified nominal grade.

6 . Magnetizable abrasive particles comprising ceramic particles having outer surfaces comprising a coating of unsintered polyion and magnetic particles bonded to the polyion.

7 . Magnetizable abrasive particles of claim 6 , wherein the polyion is selected from silicate, phosphonate, or carboxylate.

8 . Magnetizable abrasive particles of claim 6 , wherein the metal oxide comprises alumina.

9 . Magnetizable abrasive particles of claim 6 , wherein the magnetic particles comprise at least one of iron or nickel an alloy of iron, silicon and nickel, or a ferrite.

10 . Magnetizable abrasive particles of claim 9 wherein the magnetic particles have a coercivity of less than 500 Oe.

11 . Magnetizable abrasive particles of claim 4 , wherein the magnetizable abrasive particles comprise less than 25% of agglomerated magnetic particle-coated ceramic particles.

12 . Magnetizable abrasive particles of claim 4 , wherein the magnetic particles have a magnetic saturation of at least 10, 15, 20, 25, 30, 35, 40, 45 or 50 emu/gram.

13 . An abrasive article comprising a plurality of magnetizable abrasive particles according to claim 4 retained in a binder material.

14 . An abrasive article comprising the magnetizable abrasive particles according to claim 4 retained in a binder material disposed on a backing.

15 . A method of making an abrasive article, the method comprising steps:
a) applying the magnetizable abrasive particles according to claim 4 to a binder precursor; b) applying a magnetic field to orient the magnetizable abrasive particles; and c) drying and/or curing the binder precursor sufficient to fix the respective orientations of the magnetizable abrasive particles.

16 . Magnetizable abrasive particles of claim 6 , wherein the magnetizable abrasive particles comprise less than 25% of agglomerated magnetic particle-coated ceramic particles.

17 . Magnetizable abrasive particles of claim 6 , wherein the magnetic particles have a magnetic saturation of at least 10, 15, 20, 25, 30, 35, 40, 45 or 50 emu/gram.

18 . An abrasive article comprising a plurality of magnetizable abrasive particles according to claim 6 retained in a binder material.

19 . An abrasive article comprising the magnetizable abrasive particles according to claim 6 retained in a binder material disposed on a backing.

20 . A method of making an abrasive article, the method comprising steps:
a) applying the magnetizable abrasive particles according to claim 6 to a binder precursor, b) applying a magnetic field to orient the magnetizable abrasive particles; and c) drying and/or curing the binder precursor sufficient to fix the respective orientations of the magnetizable abrasive particles.

Assignees

• 3M Innovative Properties Co

Inventors

• Miller Adam D
• Manuilov Sergei
• Jing Naiyong
• Skorina Taisiya
• Nienaber Aaron K
• Eckel Joseph B
• Anderson Thomas J
• Nelson Thomas J
• Lukowski Mark A
• Moren Louis S
• West Don V

Classifications

• C04B35/6316

  Binders based on silicon compounds · CPC title

• B24D3/14

  ceramic, i.e. vitrified bondings · CPC title

• H01F1/28

  dispersed or suspended in a bonding agent · CPC title

• C04B2235/3217

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

• C04B35/62842

  Metals · CPC title