Agglomerate abrasive grain comprising incorporated hollow microspheres

Patent metadata

Field	Value
Publication number	US-10323165-B2
Application number	US-201314369892-A
Country	US
Kind code	B2
Filing date	Sep 11, 2013
Priority date	Sep 12, 2012
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

An agglomerate abrasive grain includes a mixture of individual abrasive grains and hollow bodies, wherein the abrasive grains and the hollow bodies are held together via a binding matrix of aluminosilicate and alkali silicate, and the agglomerate abrasive grain has an open porosity and a closed porosity in each case ranging from 5% by volume to 40% by volume, wherein the total porosity of the agglomerate abrasive grain is less than 50% by volume.

First claim

The invention claimed is:

1. An agglomerate abrasive grain comprising a plurality of individual abrasive grains incorporated into a binding matrix, wherein:
the abrasive grains are selected from the group consisting of corundum, fused corundum, sintered corundum, alumina zirconia, silicon carbide, boron carbide, cubic boron nitride, diamond, and mixtures thereof;
the binding matrix is obtained from a mixture of an aluminosilicate, an alkali sodium silicate, and water;
the aluminosilicate and the alkali sodium silicate having a molar ratio of Al 2 O 3 to SiO 2 ranging from 1:2 to 1:20;

the binding matrix is hardened at temperatures below 500° C.;
the agglomerate abrasive grain has an open porosity ranging from 5% by volume to 25% by volume,
the agglomerate abrasive grain further comprising hollow bodies that are incorporated into the binding matrix and that provide the agglomerate abrasive grain with a closed porosity, wherein
the hollow bodies are 5% to 40% by volume of the agglomerate abrasive grain, and
the sum of closed and open porosity is less than 50% by volume of the agglomerate abrasive grain;
further wherein the abrasive grains and the hollow bodies have an average particle diameter ranging from 5 μm to 250 μm, and wherein the ratio of the average particle diameter of the abrasive grains to the average particle diameter of the hollow bodies ranges from 2:1 to 1:2.

2. The agglomerate abrasive grain according to claim 1 , characterized in that the percentage by volume of the abrasive grains to the percentage by volume of the hollow bodies has a ratio ranging from 9:1 to 1.5:1.

3. The agglomerate abrasive grain according to claim 2 , characterized in that the percentage by volume of the abrasive grains to the percentage by volume of the hollow bodies has a ratio ranging from 6:1 to 2:1.

4. The agglomerate abrasive grain according to claim 1 , characterized in that the agglomerate abrasive grain comprises from 10% by volume to 80% by volume of abrasive grains, from 5% by volume to 40% by volume of hollow bodies, from 5% by volume to 40% by volume of binding matrix, and from 5% by volume to 25% by volume of open pores.

5. The agglomerate abrasive grain according to claim 1 , characterized in that the hollow bodies are selected from the group consisting of hollow bodies on the basis of aluminum oxide, silicon oxide, zirconium oxide, titanium oxide, cerium oxide, and/or mixtures thereof.

6. The agglomerate abrasive grain according to claim 5 , characterized in that the hollow bodies are hollow spheres made of glass.

7. The agglomerate abrasive grain according to claim 1 , characterized in that the agglomerate abrasive grain comprises from 5% by weight to 30% by weight of binding matrix, from 60% by weight to 95% by weight of abrasive grains, and from 0.3% by weight to 20% by weight of hollow bodies.

8. A method for producing agglomerate abrasive grains according to claim 1 , wherein a mixture of individual abrasive grains and hollow bodies are incorporated into a binding matrix of aluminosilicate and alkali sodium silicate having a molar ratio of Al 2 O 3 to SiO 2 ranging from 1:2 to 1:20, the method comprising:
mixing the abrasive grains and hollow bodies with the binding agent of aluminosilicate, alkali sodium silicate, and water,
drying the agglomerate abrasive grain green bodies obtained in this manner at a temperature ranging from 80° to 150° C.;
classifying the dried agglomerate abrasive grain green bodies to a defined abrasive grit size; and
hardening the dried and classified agglomerate abrasive grains at a temperature below 500° C.

Assignees

• Imertech Sas

Inventors

• Gebhardt Knuth
• Zylka Georg Paul

Classifications

• C04B28/26

  Silicates of the alkali metals · CPC title

• C09K3/1436 Primary

  Composite particles, e.g. coated particles · CPC title

• C09G1/02

  containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} · CPC title

• C04B28/006

  containing mineral polymers, e.g. geopolymers of the Davidovits type · CPC title

• C04B2111/00215

  Mortar or concrete mixtures defined by their oxide composition · CPC title