Thermal insulation and method of producing the same

Patent metadata

Field	Value
Publication number	US-9982831-B2
Application number	US-201615192194-A
Country	US
Kind code	B2
Filing date	Jun 24, 2016
Priority date	Oct 16, 2009
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

Provided is a thermal insulation having both excellent thermal insulating performance and excellent strength, and a method of producing the same. A method of producing a thermal insulation according to the present invention includes curing (S 2 ) a dry-pressed compact, including silica fine particles each having an average particle diameter of 50 nm or less and a reinforcement fiber, at a relative humidity of 70% or more.

First claim

What is claimed is:

1. A method of producing a thermal insulation, comprising:
dry mixing a raw material for a thermal insulation and at least one of an alkaline-earth metal hydroxide and an alkali metal hydroxide, the raw material comprising silica fine particles each having an average particle diameter of 50 nm or less and reinforcement fibers;
subjecting the dry mixture to dry-press forming to obtain a dry-pressed compact, the dry-pressed compact being one formed body wherein the silica fine particles, the reinforcement fibers and the at least one of an alkaline-earth metal hydroxide and an alkali metal hydroxide being mixed, the at least one of an alkaline-earth metal hydroxide and an alkali metal hydroxide being 0.1 to 10 parts by weight with respect to 100 parts by weight of the raw material; and
curing the dry-pressed compact at a relative humidity of 70% or more.

2. The method of producing a thermal insulation according to claim 1 , wherein the dry-pressed compact comprises 50 to 98 mass % of the silica fine particles and 2 to 20 mass % of the reinforcement fiber.

3. The method of producing a thermal insulation according to claim 1 , wherein the thermal insulation has a bulk density of 190 to 600 kg/m 3 and has a compressive strength of 0.65 MPa or more.

4. The method of producing a thermal insulation according to claim 1 , wherein the thermal insulation has a thermal conductivity at 600° C. of 0.05 W/(m·K) or less.

5. The method of producing a thermal insulation according to claim 1 , wherein the dry-pressed compact comprises Ca(OH) 2 .

6. The method of producing a thermal insulation according to claim 5 , wherein the dry-pressed compact comprises the Ca(OH) 2 at 0.1 to 10 parts by weight with respect to 100 parts by weight of a raw material for the thermal insulation comprising the silica fine particles, and the reinforcement fiber.

7. The method of producing a thermal insulation according to claim 1 , wherein the dry-pressed compact is cured at a temperature of 40° C. to 95° C. and a duration of 2 hours or more.

8. The method of producing a thermal insulation according to claim 5 , wherein the dry-pressed compact comprises the Ca(OH) 2 at 1 to 10 parts by weight with respect to 100 parts by weight of a raw material for the thermal insulation comprising the silica fine particles, and the reinforcement fiber.

9. The method of producing a thermal insulation according to claim 1 , wherein the curing is conducted in an autoclave.

10. The method of producing a thermal insulation according to claim 1 , wherein the dry-pressed compact is cured at 40° C. to 200° C. for 2 hours or more under a pressurized condition.

11. The method of producing a thermal insulation according to claim 1 , wherein the method further comprises drying the cured dry-pressed compact.

12. The method of producing a thermal insulation according to claim 1 , wherein the dry-pressed compact further comprises a thermal radiation scattering material.

13. The method of producing a thermal insulation according to claim 12 , wherein the thermal radiation scattering material is at least one selected from the group consisting of silicon carbide, zirconia and titania.

14. The method of producing a thermal insulation according to claim 12 , wherein the dry-pressed compact comprises 50 to 93 mass % of the silica fine particles, 2 to 20 mass % of the reinforcement fiber, and 5 to 40 mass % of the thermal radiation scattering material.

15. The method of producing a thermal insulation according to claim 1 , wherein the dry-pressed compact comprises 1 to 7 parts by weight of the at least one of an alkaline-earth metal hydroxide and an alkali metal hydroxide with respect to 100 parts by weight of the raw material.

16. The method of producing a thermal insulation according to claim 1 , wherein the dry-pressed compact comprises 2 to 5 parts by weight of the at least one of an alkaline-earth metal hydroxide and an alkali metal hydroxide with respect to 100 parts by weight of the raw material.

17. The method of producing a thermal insulation according to claim 1 , wherein when the dry-pressed compact comprises 0.1 to 2 parts by weight of the at least one of an alkaline-earth metal hydroxide and an alkali metal hydroxide with respect to 100 parts by weight of the raw material, a curing time is 6 hours or more; and
when the dry-pressed compact comprises more than 2 parts by weight and 10 parts by weight or less of the at least one of an alkaline-earth metal hydroxide and an alkali metal hydroxide with respect to 100 parts by weight of the raw material, a curing time is 6 hours or less.

Assignees

• Nichias Corp

Inventors

• Ito Yasuo
• Goto Yoshihiko
• Abe Isami
• Nakama Shigeru
• Ohmura Takahiro

Classifications

• C04B40/0259

  Hardening promoted by a rise in pressure (C04B40/024 takes precedence) · CPC title

• E04B1/80

  slab-shaped · CPC title

• C04B14/062

  Microsilica, e.g. colloïdal silica (preparing microsilica slurries or suspensions C04B18/148) · CPC title

• C04B22/062

  of the alkali or alkaline-earth metals · CPC title

• F16L59/028 Primary

  Compositions for or methods of fixing a thermally insulating material · CPC title