Process for preparing silicate porous product

• US 6,811,602 B2
• Filed: 03/27/2002
• Issued: 11/02/2004
• Est. Priority Date: 03/28/2001
• Status: Expired due to Fees

• Current Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Original Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Inventors: Beppu, Yoshihisa, Kondoh, Shinji
• Primary Examiner(s): Marcantoni, Paul
• Application Number:
  US10/106,370
• Publication Number:
  US 20020183193A1
• Time in Patent Office: 951 Days
• Field of Search: 106/600, 106/602, 501/80, 501/85, 501/141, 501/145, 501/146, 501/149, 264/44, 423/333, 423/334, 252/62
• US Class Current: 106/600
• CPC Class Codes: B01D 2253/106 Silica or silicates
• CPC Class Codes: B01D 39/2093 Ceramic foam
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01J 20/10 comprising silica or silicate
• CPC Class Codes: B01J 20/12 Naturally occurring clays or bleaching earth
• CPC Class Codes: B01J 21/16 Clays or other mineral silicates
• CPC Class Codes: B01J 37/32 Freeze drying, i.e. lyophilisation
• CPC Class Codes: B28B 1/007 by freezing the material
• CPC Class Codes: B28B 1/50 specially adapted for producing articles of expanded material, e.g. cellular concrete chemical aspects or making expanded aggregate C04B
• CPC Class Codes: C04B 33/00 Clay-wares monolithic refractories or refractory mortars C04B35/66; porous products C04B38/00
• CPC Class Codes: C04B 35/16 based on silicates other than clay zircon C04B35/48
• CPC Class Codes: C04B 38/00 Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof treating slag with gases or gas generating material C04B5/06 ; expanded graphite C04B35/536
• CPC Class Codes: C04B 38/0074 expressed as porosity percentage
• CPC Class Codes: C04B 38/0605 by sublimating
• CPC Class Codes: C04B 40/0021 Sonic or ultrasonic waves, e.g. to initiate sonochemical reactions
• CPC Class Codes: C04B 40/0089 making use of vacuum or reduced pressure
• CPC Class Codes: C04B 40/0683 inhibiting by freezing or cooling
• CPC Class Codes: F01N 2330/00 Structure of catalyst support or particle filter
• CPC Class Codes: F01N 2330/10 Fibrous material, e.g. mineral or metallic wool

Abstract

A process for preparing a silicate porous product, which comprises a step of forming a clay mineral into a dispersion by means of a dispersant, a step of removing gases dissolved in the dispersion, a step of freezing the dispersion and drying it in its frozen state under reduced pressure, and a step of firing the dried product obtained by the drying.

Claims

1. A process for preparing a silicate porous product, which comprises a step of forming a clay mineral into a dispersion by means of a dispersant, a step of removing gases dissolved in the dispersion, a step of freezing the dispersion and drying it in its frozen state under reduced pressure, and a step of firing the dried product obtained by the drying.

2. The process for preparing a silicate porous product according to claim 1, wherein the clay mineral is sheet silicate, amorphous silicate or quasi-crystalline silicate, or a mixture thereof.

3. The process for preparing a silicate porous product according to claim 1, wherein the clay mineral is dispersed in an amount of from 1 to 20 mass % in the dispersion.

4. The process for preparing a silicate porous product according to claim 1, wherein the dispersant is a mixture comprising water and an alcohol.

5. The process for preparing a silicate porous product according to claim 4, wherein the content of the alcohol is from 10 to 50 vol %.

6. The process for preparing a silicate porous product according to claim 1, wherein the reduced pressure is not more than 1,000 Pa.

7. The process for preparing a silicate porous product according to claim 1, wherein in the step of removing gases, the gases are removed by degassing under reduced pressure or degassing under ultrasonic irradiation, or by employing both.

8. The process for preparing a silicate porous product according to claim 1, wherein in the firing step, heating is carried out at a temperature of at least 800°

C.

9. The process for preparing a silicate porous product according to claim 1, wherein in the firing step, heating is carried out at a temperature of from 850°

C. to 1,200°

C.

10. The process for preparing a silicate porous product according to claim 1, wherein in the firing step, heating is carried out at a temperature of from 1,000°

C. to 1,100°

C.

11. The process for preparing a silicate porous product according to claim 1, wherein the silicate porous product has a porosity of at least 90%.