Granular pumice and method for producing granular pumice

Patent metadata

Field	Value
Publication number	US-9388075-B2
Application number	US-201414477348-A
Country	US
Kind code	B2
Filing date	Sep 4, 2014
Priority date	May 26, 2010
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

The invention relates to granular pumice, wherein the surface is covered with a hydrophobic coating.

First claim

The invention claimed is:

1. A granular pumice comprising:
a surface coated with a hydrophobic coating;
wherein the coating comprises a silane or a siloxane;
wherein the silane is:
A1) a silane of the general formula:
R 3 —Si—(OR 2 ) 3 ;

where:
R 2 is a methyl or ethyl radical; and
R 3 is:
an alkyl radical having from 3 to 12 carbon atoms; or
an aminoalkyl radical having from 1 to 6 carbon atoms; or
a radical of the general formula
H 2 N—(CH 2 ) x R 4 —(CH 2 ) y —, where:

R 4 is an oxygen, sulfur, —NH—, or
—NH—CH 2 —CH 2 —NH— radical;
x≧2; and
y≧2; or

a radical of the general formula:
(R 2 O) 3 Si—(CH 2 ) x —NH—(CH 2 ) x —;

where R 2 and x
are as defined above;

where n is an integer from 1 to 5,
wherein the siloxane is:
A2) a siloxanol of the general formula:

where:
R 5 is a methyl or phenyl radical, with at least 90% of the radicals R 5 being methyl radicals; and
m=20 to 250.

2. The granular pumice as claimed in claim 1 ;
wherein the coating additionally comprises at least one compound selected from organic fatty acids and salts of organic fatty acids.

3. The granular pumice as claimed in claim 1 ;
wherein the coating additionally comprises a mineral oil or a mineral oil emulsion.

4. The granular pumice as claimed in claim 1 :
wherein the coating additionally comprises at least one alkane.

5. The granular pumice as claimed in claim 1 ;
wherein the coating additionally comprises bitumen or a bituminous emulsion.

6. A process for producing the granular pumice as claimed in claim 1 , comprising:
wetting the surface of the granular pumice with an emulsion containing at least one hydrophobicizing agent which is distributed in an outer phase of the emulsion, and which forms the inner phase of the emulsion; and
subsequently drying the granular pumice, so that the hydrophobicizing agent forms the hydrophobic coating on the surface of the granular pumice.

7. The process as claimed in claim 6 ;
wherein the emulsion is sprayed on.

8. The process as claimed in claim 6 ;
wherein the granular pumice is mixed during and after addition of the emulsion.

9. The process as claimed in claim 8 ;
wherein the mixing time is 1 min to 25 min.

10. The process as claimed in claim 6 ;
wherein the wetted granular pumice is dried at a temperature of 0°−200° C.

11. The process as claimed in claim 6 ;
wherein the hydrophobicizing agent additionally comprises at least one compound selected from organic fatty acids and salts of organic fatty acids.

12. The process as claimed in claim 6 ;
wherein the hydrophobicizing agent additionally comprises mineral oil.

13. The process as claimed in claim 6 ;
wherein the hydrophobicizing agent additionally comprises an alkane.

14. The process as claimed in claim 6 ;
wherein the hydrophobicizing agent additionally comprises bitumen.

15. The process as claimed in claim 6 ;
wherein the outer phase of the emulsion comprises water.

16. The process as claimed in claim 6 ;
wherein a content in grams of the hydrophobicizing agent in the wetted granular pumice is 0.1% to 2.5% of an amount in grams of granular pumice which is wetted.

17. The process as claimed in claim 6 ;
wherein an amount in grams of the outer phase of the emulsion is ⅕ to ⅓ of an amount in grams of granular pumice which is wetted.

Assignees

• Evonik Degussa Gmbh
• Rotec Rohstoff Technik Gmbh & Co Kg

Inventors

• Roos Markus
• Runkel Guido

Classifications

• C08J7/0427

  with only one layer of a composition containing a polymer binder (with more layers C08J7/042) · CPC title

• Y10T428/2996

  Glass particles or spheres · CPC title

• Y10T428/2998

  including synthetic resin or polymer · CPC title

• C09D4/00

  Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond {; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16} · CPC title

• Y10T428/2991

  Coated · CPC title