Granules

Patent metadata

Field	Value
Publication number	US-2024018042-A1
Application number	US-202318372022-A
Country	US
Kind code	A1
Filing date	Sep 22, 2023
Priority date	May 16, 2016
Publication date	Jan 18, 2024
Grant date	—

Abstract

A plurality of granules comprising ceramic particles bound together with an inorganic binder, the inorganic binder comprising reaction product of at least alkali silicate and hardener, wherein the ceramic particles are present as at least 50 percent by weight of each granule, based on the total weight of the respective granule, wherein each granule has a total porosity in a range from greater than 0 to 50 percent by volume, based on the total volume of the respective granule, and wherein the granule has a minimum Total Solar Reflectance of at least 0.7. The granules are useful, for example, as roofing granules.

First claim

What is claimed is:

1 . A method of making a plurality of granules comprising ceramic particles bound together with an inorganic binder, the inorganic binder comprising reaction product of at least alkali silicate and hardener, wherein the ceramic particles are present as at least 50 percent by weight of each granule, based on the total weight of the respective granule, wherein each granule has a total porosity in a range from greater than 0 to 50 percent by volume, based on the total volume of the respective granule, and wherein the granule has a minimum Total Solar Reflectance of at least 0.70. of any preceding claim, the method comprising one of:
curing an aqueous dispersion comprising ceramic particles, alkali silicate precursor, and hardener to provide cured material; and crushing the cured material to provide the granules.

2 . The method of claim 1 , wherein the curing is conducted at least in part at a temperature in a range from 40° C. to 500° C.

3 . The method of claim 2 , wherein the curing is conducted in two stages, a first curing stage at least in part at a temperature in a range from 20° C. to 100° C., and a second curing stage at least in part at a temperature in a range from 200° C. to 500° C.

4 . The method of claim 3 , wherein the heating rate for each stage is at one or more rates in a range from 5° C./min. to 50° C./min.

5 . The method of claim 1 , wherein water is present in the aqueous dispersion up to 75 percent by weight, based on the total weight of the aqueous dispersion.

6 . The method of claim 1 , wherein the hardener is amorphous aluminosilicate.

7 . The method of claim 1 , wherein the alkali silicate is sodium silicate.

8 . The method of claim 1 , wherein the ceramic particles are a metal or metalloid oxide.

9 . The method of making the plurality of granules comprising ceramic particles bound together with an inorganic binder, the inorganic binder comprising reaction product of at least alkali silicate and hardener, wherein the ceramic particles are present as at least 50 percent by weight of each granule, based on the total weight of the respective granule, wherein each granule has a total porosity in a range from greater than 0 to 50 percent by volume, based on the total volume of the respective granule, and wherein the granule has a minimum Total Solar Reflectance of at least 0.70, the method comprising one of:
mixing material comprising ceramic particles, alkali silicate precursor, and hardener to provide agglomerates comprising ceramic particles, alkali silicate precursor, and hardener; and curing the agglomerates to provide the granules.

10 . The method of claim 9 , wherein the material is an aqueous dispersion.

11 . The method of claim 9 , wherein water is added to the material during mixing.

12 . The method of claim 9 , wherein the curing is conducted at least in part at a temperature in a range from 40° C. to 500° C.

13 . The method of claim 12 , wherein the curing is conducted in two stages, a first curing stage at least in part at a temperature in a range from 20° C. to 100° C., and a second curing stage at least in part at a temperature in a range from 200° C. to 500° C.

14 . The method of claim 13 , wherein the heating rate for each stage is at one or more rates in a range from 5° C./min. to 50° C./min.

15 . The method of claim 14 , wherein water is present in the aqueous dispersion up to 75 percent by weight, based on the total weight of the aqueous dispersion.

16 . The method of making the plurality of granules comprising ceramic particles bound together with an inorganic binder, the inorganic binder comprising reaction product of at least alkali silicate and hardener, wherein the ceramic particles are present as at least 50 percent by weight of each granule, based on the total weight of the respective granule, wherein each granule has a total porosity in a range from greater than 0 to 50 percent by volume, based on the total volume of the respective granule, and wherein the granule has a minimum Total Solar Reflectance of at least 0.70, the method comprising one of:
spray drying an aqueous dispersion comprising ceramic particles, alkali silicate precursor, and hardener to provide agglomerates comprising ceramic particles, alkali silicate precursor, and hardener; and curing the agglomerates to provide the granules.

17 . The method of claim 16 , wherein the curing is conducted at least in part at a temperature in a range from 40° C. to 500° C.

18 . The method of claim 17 , wherein the curing is conducted in two stages, a first curing stage at least in part at a temperature in a range from 20° C. to 100° C., and a second curing stage at least in part at a temperature in a range from 200° C. to 500° C.

19 . The method of claim 18 , wherein the heating rate for each stage is at one or more rates in a range from 5° C./min. to 50° C./min.

20 . The method of claim 16 , wherein water is present in the aqueous dispersion up to 75 percent by weight, based on the total weight of the aqueous dispersion.

Assignees

• 3M Innovative Properties Company

Inventors

• Skorina Taisiya
• Rosenflanz Anatoly Z
• Tangeman Jean A
• Budd Kenton D

Classifications

• C04B28/26 Primary

  Silicates of the alkali metals · CPC title

• E04D2001/005

  the roofing elements having a granulated surface · CPC title

• E04D1/00

  Roof covering by making use of tiles, slates, shingles, or other small roofing elements (roofing supports {or underlayers} E04D12/00) · CPC title

• C04B14/305

  Titanium oxide, e.g. titanates · CPC title

• C04B14/303

  Alumina · CPC title