Process for preparing an insulating material

Patent metadata

Field	Value
Publication number	US-9328508-B2
Application number	US-201113993968-A
Country	US
Kind code	B2
Filing date	Dec 7, 2011
Priority date	Dec 15, 2010
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

Process for manufacturing a thermally insulating material comprising the following steps:
a) preparing an aqueous mixture of a solid mineral substance in suspension having a specific surface area S of greater than 5 m 2 /g; b) adding to the mixture at least one pore-forming agent; c) stirring so as to obtain a homogeneous mixture; d) preforming a substrate from the homogeneous mixture; e) optionally drying the substrate at least partially; f) removing, at least partially, the pore-forming agent;

and such that said specific surface area S, expressed in m 2 /g and measured by BET, and the mean particle diameter Dpm of the pore-forming agents, expressed in micrometers and measured by dynamic light scattering, obey the relation:

1/ S <Dpm<50/ S.

First claim

The invention claimed is:

1. A process for manufacturing a thermally insulating material, the process comprising:
a) preparing an aqueous mixture of a solid mineral substance in suspension having a specific surface area S of greater than 5 m 2 /g;
b) adding at least one pore-forming agent comprising particles, to the aqueous mixture, to obtain an intermediate mixture;
c) stirring the intermediate mixture, to obtain a homogeneous mixture;
d) preforming a substrate from the homogeneous mixture;
e) optionally, drying the substrate at least partially;
f) removing, at least partially, the pore-forming agent;
wherein a specific surface area S, expressed in m 2 /g and measured by BET, and a mean particle diameter Dpm of the particles of the at least one pore-forming agent, expressed in micrometers and measured by dynamic light scattering, satisfy the relation:
1/ S <Dpm<50/ S.

2. The process of claim 1 , wherein the specific surface area S and the mean particle diameter Dpm of the pore-forming agents satisfy the relation:
3/ S <Dpm<30/ S.

3. The process of claim 1 , wherein the weight ratio of the mineral substance relative to the pore-forming agent is from 0.2 to 3.

4. The process of claim 1 , wherein the mineral substance is at least one selected from the group consisting of a silicate, an amorphous silica, a carbonate, and a clay.

5. The process of claim 1 , wherein the mineral substance is at least one selected from the group consisting of precipitated silica and pyrogenic silica.

6. The process of claim 1 , wherein the pore-forming agent is at least one synthetic latex particle.

7. The process of claim 1 , wherein the pore-forming agent is at least one water-dispersible acrylic copolymer having a glass transition temperature in a range from 50° C. to 200° C., wherein the acrylic copolymer is in emulsion in water at a weight fraction between 5% and 75% of the total weight of the pore-forming agent.

8. The process of claim 1 , wherein, during the preforming d), the substrate is preformed by molding, extrusion, or deposition on a conveyor.

9. The process of claim 1 , wherein the removing f) comprises at least one temperature rise in order to reach a temperature hold between 350° C. and 750° C., the temperature is maintained for, in particular, at least 4 hours and then left to return to room temperature.

10. The process of claim 1 , wherein the weight ratio of the mineral substance relative to the pore-forming agent is from 0.7 to 2.5.

11. The process of claim 1 , wherein the mineral substance is at least one selected from the group consisting of a precipitated silica, a pyrogenic silica, a fumed silica, a silica gel and a silica aerogel.

Assignees

• Louapre David
• Parneix Caroline
• Grigorova Veneta
• Gilles Jerome
• Saint Gobain Isover

Inventors

• Louapre David
• Parneix Caroline
• Grigorova Veneta
• Gilles Jerome

Classifications

• C04B38/067

  Macromolecular compounds (C04B38/062 takes precedence) · CPC title

• B29C44/02

  for articles of definite length, i.e. discrete articles · CPC title

• C04B24/2641

  Polyacrylates; Polymethacrylates · CPC title

• B28B1/00

  Producing shaped {prefabricated} articles from the material (using presses B28B3/00; shaping on moving conveyors B28B5/00; producing tubular articles B28B21/00 {; producing articles with embedded elements B28B23/00}) · CPC title

• E04B1/80 Primary

  slab-shaped · CPC title