Claims
- 1. A heat resistant layered porous silica having a honeycomb porous structure comprising a plurality of waved or bent sheet layers of crystalline layered silicate, said sheet layers being superposed one after another in a manner that the spacing between the neighboring sheet layers is narrowed toward bent portions defining ridges thereof where the sheet layers are bonded by siloxane bonding and the spacings is expanded at parts between the bonded portions to form fine pores, wherein
- said layered porous silica contains alkali metal ions in an amount of 0.2% by weight or less and has a specific surface area of 1,000 m.sup.2 /g or more.
- 2. A heat resistant layered porous silica as claimed in claim 1, wherein the crystalline layered silicate is kanemite synthesized from amorphous sodium silicate containing Na.sub.2 O and SiO.sub.2 at an SiO.sub.2 /Na.sub.2 O ratio of nearly 2.
- 3. A heat resistant layered porous silica as claimed in claim 1, wherein the surface of the layered porous silica is hydrophobic.
- 4. A heat resistant layered porous silica as claimed in claim 1, wherein the diameter of the fine pores of the layered porous silica is distributed within a range of from 1 to 60.ANG..
- 5. A process for producing a heat resistant layered porous silica, which comprises:
- expanding the interlayer spacings of a crystalline layered silicate containing not less than 10% by weight of water, by exchanging interlayer alkali metal ions being present in said crystalline layered silicate for cations of an organic substance to thereby introduce said cations of the organic substance into the spacings between the layers of said crystalline layered silicate;
- rinsing the ion-exchanged crystalline layered silicate to remove free alkali metal ions which were released by the ion exchange step above; and
- calcining the ion-exchanged crystalline layered silicate to obtain layered porous silica by calcining said cations of the organic substance.
- 6. A process for producing a heat resistant layered porous silica as claimed in claim 5, wherein the layered porous silica is at least one selected from the group consisting of kanemite, sodium disilicate, makatite, ilerite, magadiite, and kenyaite.
- 7. A process for producing a heat resistant layered porous silica as claimed in claim 5, wherein the cation of the organic substance is at least one selected from group consisting of cations of an alkyltrimethylammonium, a dimethyldialkylammonium, an alkylammonium, and benzyltrimethylammonium.
- 8. A process for producing a heat resistant layered porous silica as claimed in claim 5, wherein the ion exchange step is conducted in the pH range of from 8 to 9, and is then followed by heating to a temperature range of from 30.degree. to 90.degree. C. before carrying out calcination.
- 9. A process for producing a heat layered porous silica as claimed in claim 5, wherein the rinsing step comprises repeating rinsing for at least twice.
- 10. A process for producing a heat resistant layered porous silica as claimed in claim 5, wherein the crystalline layered silicate is rendered porous by carrying out calcining in a temperature range of from 600.degree. to 1,200.degree. C.
- 11. A heat resistant layered porous silica as claimed in claim 1, wherein said neighboring sheet layers are partly bonded by siloxane bonds on portions of said neighboring sheet layers, without organic cations introduced therebetween.
- 12. A heat resistant layered porous silica as claimed in claim 1, wherein the specific surface area is over 1000 m.sup.2 /g after 6 hours' calcination at about 600.degree. to about 800.degree. C.
- 13. A heat resistant layered porous silica as claimed in claim 1, wherein the specific surface area is over 750 m.sup.2 /g after 6 hours' calcination at about 1000.degree. C.
- 14. A heat resistant layered porous silica as claimed in claim 1, wherein the adsorption capacity does not decline due to repetitive adsorptions and desorptions of organic molecules.
- 15. A heat resistant layered porous silica as claimed in claim 1, wherein the interlayer spacings of the crystalline layered silicate are substantially free of organic cations.
- 16. A heat resistant layered porous silica as claimed in claim 1, wherein the water content of the crystalline layered silicate is over 20 wt %.
- 17. A heat resistant layered porous silica as claimed in claim 1, wherein the water content of the crystalline layered silicate is over 50 wt %.
- 18. A process for producing a heat resistant layered porous silica as claimed in claim 5, wherein the water content said crystalline layered silicate is over 20 wt %.
- 19. A process for producing a heat resistant layered porous silica as claimed in claim 5, wherein the water content of said crystalline layered silicate is over 50 wt %.
- 20. The process for producing a heat resistant layered porous silica as claimed in claim 5, wherein a specific surface area of 1000 m.sup.2 /g or more is attained by calcination of the crystalline layered silicate at a temperature between about 600.degree. to about 800.degree. C.
- 21. The process for producing a heat resistant layered porous silica as claimed in claim 5, wherein a specific surface area of 750 m.sup.2 /g or more is attained by calcination of the crystalline layered silicate at a temperature of about 1000.degree. C.
Priority Claims (1)
Number |
Date |
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Kind |
4-200255 |
Jul 1992 |
JPX |
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Parent Case Info
This is a continuation-in-part application of application Ser. No. 07/937,032, filed Aug. 31, 1992 for FUEL-SORBING DEVICE USING LAYERED POROUS SILICA, which is a continuation-in-part of application Ser. No. 07/820,167, filed Jan. 13, 1992 for POROUS MATERIAL COMPOSED OF LAYERED SILICA AND METAL OXIDE AND A PROCESS FOR MANUFACTURING THE SAME.
US Referenced Citations (18)
Non-Patent Literature Citations (1)
Entry |
Tsuneo Yanagisawa, et al., "The Preparation of Alkyltrimethylammonium-Kanemite Complexes and Their Conversion to Microporous Materials"; The Chemical Society of Japan, vol. 63, No. 4, Apr., 1990, pp. 988-992. |
Continuation in Parts (2)
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Number |
Date |
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Parent |
937032 |
Aug 1992 |
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Parent |
820167 |
Jan 1992 |
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