Methods for characterizing expandable perlite, articles containing expandable perlite and methods for making same

Patent metadata

Field	Value
Publication number	US-2025059088-A1
Application number	US-202418807089-A
Country	US
Kind code	A1
Filing date	Aug 16, 2024
Priority date	Aug 18, 2023
Publication date	Feb 20, 2025
Grant date	—

Abstract

The present disclosure relates generally to methods for characterizing unexpanded perlite, e.g., with respect to its expandability as well as articles containing expandable perlite, such as gypsum materials, fire-resistant building boards and other fire-resistant materials, and methods for making the same. The present inventors have determined thermogravimetric methods for characterizing unexpanded perlite with high predictive power for the selection of highly-expandable perlites. The disclosure also relates to materials including unexpanded perlites that meet certain threshold values with respect to these characterization methods.

First claim

1 . A fire-resistant set gypsum material comprising
a set body of calcium sulfate dihydrate; and dispersed in the set body of calcium sulfate dihydrate, an unexpanded perlite, the unexpanded perlite having one or more of
(a) a first mass loss of at least a first threshold value, the first threshold value being at least 0.7 wt %, the first mass loss being determined by subjecting the unexpanded perlite to thermogravimetric analysis (TGA) at a first heating rate of 20° C./minute over a first temperature range from a first lower limit of 700° C. to a first upper limit of 900° C. and determining as the first mass loss the mass lost over the first temperature range;
(b) a second mass loss of at least a second threshold value, the second threshold value being at least 0.04 wt %, the second mass loss being determined by subjecting the unexpanded perlite to TGA at a heating rate of 30° C./minute over a second temperature range from a second lower limit of 600° C. to a second upper limit of 800° C. and determining as the second mass loss an excess mass loss over the second temperature range, the excess mass loss being defined as a mass loss in excess of a mass loss represented by a line interpolated on a graph of mass loss vs. temperature from the second lower limit to the second upper limit; and
(c)
(i) a third mass loss of at least a third threshold value, the third threshold value being at least 0.45 wt %, the third mass loss being a difference between a stabilized mass of the unexpanded perlite at a third lower temperature of 500° C. and a stabilized mass of the sample at a third upper temperature that is 1000° C.; and
(ii) a D50 particle size of at least a fourth threshold value, the fourth threshold value being 400 microns.

2 . The fire-resistant set gypsum material according to claim 1 , wherein the unexpanded perlite has (a) a first mass loss of at least a first threshold value, the first threshold value being at least 0.7 wt %, the first mass loss being determined by subjecting the unexpanded perlite to thermogravimetric analysis (TGA) at a first heating rate of 20° C./minute over a first temperature range from a first lower limit of 700° C. to a first upper limit of 900° C. and determining as the first mass loss the mass lost over the first temperature range.

3 . The fire-resistant set gypsum material according to claim 1 , wherein the first threshold value is at least 0.75 wt %.

4 . The fire-resistant set gypsum material according to claim 1 , wherein the unexpanded perlite has (b) a second mass loss of at least a second threshold value, the second threshold value being at least 0.04 wt %, the second mass loss being determined by subjecting the unexpanded perlite to TGA at a heating rate of 30° C./minute over a second temperature range from a second lower limit of 600° C. to a second upper limit of 800° C. and determining as the second mass loss an excess mass loss over the second temperature range, the excess mass loss being defined as a mass loss in excess of a mass loss represented by a line interpolated on a graph of mass loss vs. temperature from the second lower limit to the second upper limit.

5 . The fire-resistant set gypsum material according to claim 1 , wherein the second threshold value is at least 0.07 wt %.

6 . The fire-resistant set gypsum material according to claim 1 , wherein the unexpanded perlite has (c) (i) a third mass loss of at least a third threshold value, the third threshold value being at least 0.45 wt %, the third mass loss being a difference between a stabilized mass of the unexpanded perlite at a third lower temperature of 500° C. and a stabilized mass of the sample at a third upper temperature that is 1000° C.; and (ii) a D50 particle size of at least a fourth threshold value, the fourth threshold value being 400 microns.

7 . The fire-resistant set gypsum material according to claim 1 , wherein the third threshold value is at least 0.5 wt %.

8 . The fire-resistant set gypsum material according to claim 1 , wherein the fourth threshold value is at least 500 microns.

9 . The fire-resistant set gypsum material according to claim 1 , wherein the unexpanded perlite has one or both of:
(b) a second mass loss of at least a second threshold value, the second threshold value being at least 0.04 wt %, the second mass loss being determined by subjecting the unexpanded perlite to TGA at a heating rate of 30° C./minute over a second temperature range from a second lower limit of 600° C. to a second upper limit of 800° C. and determining as the second mass loss an excess mass loss over the second temperature range, the excess mass loss being defined as a mass loss in excess of a mass loss represented by a line interpolated on a graph of mass loss vs. temperature from the second lower limit to the second upper limit; and (c) (i) a third mass loss of at least a third threshold value, the third threshold value being at least 0.45 wt %, the third mass loss being a difference between a stabilized mass of the unexpanded perlite at a third lower temperature of 500° C. and a stabilized mass of the sample at a third upper temperature that is 1000° C.; and (ii) a D50 particle size of at least a fourth threshold value, the fourth threshold value being 400 microns.

10 . The fire-resistant set gypsum material according to claim 9 , wherein the unexpanded perlite further has (a) a first mass loss of at least a first threshold value, the first threshold value being at least 0.7 wt %, the first mass loss being determined by subjecting the unexpanded perlite to thermogravimetric analysis (TGA) at a first heating rate of 20° C./minute over a first temperature range from a first lower limit of 600° C. to a first upper limit of 800° C. and determining as the first mass loss the mass lost over the first temperature range.

11 . The fire-resistant set gypsum material according to claim 1 , wherein the unexpanded perlite has a D50 particle size of at least 100 microns.

12 . The fire-resistant set gypsum material according to claim 1 , wherein the unexpanded perlite is present in an amount of at least 0.5 wt %, based on the weight of the set gypsum material.

13 . A method of making a fire-resistant set gypsum material according to claim 1 , the method comprising:
providing a moist composition comprising stucco, water, and unexpanded perlite; allowing the moist composition to set to from a wet gypsum material; and drying the wet gypsum material at a temperature in the range of 50-350° C. to provide the set gypsum material.

14 . A fire-resistant building board comprising a set gypsum core having a first major surface and a second, opposing major surface, wherein the set gypsum core comprises a fire-resistant set gypsum material according to claim 1 .

15 . A method of forming a fire-resistant building board as defined in claim 14 , comprising:
providing a slurry comprising stucco, water, and unexpanded perlite; allowing the slurry to set to form a wet gypsum core; and drying the wet gypsum core at a temperature in the range of 50-350° C. to provide the set gypsum core.

16 . A method for characterizing a sample of unexpanded perlite with respect to thermal expansion performance, the method comprising performing one or more of the following:
(a)
subjecting the unexpanded perlite to thermogravimetric analysis (TGA) at a first heating rate of at least 10° C./minute over a first temperature range from a first lower limit of no more than 700° C. to a first upper limit of at least 800° C.;
determining a first mass loss over the first temperature range; and
characterizing the unexpand

Assignees

• Saint Gobain Placo

Inventors

• Lespiat Remi
• Baradari Hiva
• Beaugnon Florian
• Grange Marion
• Godefroid Julie
• Arzakantsyan Mikayel

Classifications

• G01N25/00

  Investigating or analyzing materials by the use of thermal means (G01N3/00 - G01N23/00 take precedence) · CPC title

• G01N5/04

  by removing a component, e.g. by evaporation, and weighing the remainder · CPC title

• C04B2111/285

  Intumescent materials · CPC title

• C04B2111/0062

  Gypsum-paper board like materials · CPC title

• C04B2103/63

  Flame-proofing agents · CPC title