Chemistry of inorganic compounds – Silicon or compound thereof – Oxygen containing
Reexamination Certificate
2001-01-04
2002-10-22
Silverman, Stanley S. (Department: 1754)
Chemistry of inorganic compounds
Silicon or compound thereof
Oxygen containing
C423S330100
Reexamination Certificate
active
06468492
ABSTRACT:
FIELD OF THE INVENTION
This invention concerns a method to prepare an aluminosilicate polymer, and the use of the polymer obtained by said method in the treatment of photographic processing effluents.
BACKGROUND OF THE INVENTION
Aluminosilicate polymers are known. A filamentous tubular crystallized aluminosilicate designated imogolite occurs naturally in volcanic ash. U.S. Pat. Nos. 4,152,404 and 4,252,779 describe the synthetic preparation of substances related to imogolites. U.S. Pat. No. 5,888,711 describes a method to obtain directly a fibrous aluminosilicate polymer of high purity of formula Al
x
Si
y
O
z
, where x:y is 1 to 3 and z is from 1 to 10. A variant of this method that affords a morphological variety of this aluminosilicate polymer is described in French Patent application 2 767 128.
SUMMARY OF THE INVENTION
The object of this invention is an improvement of the synthesis of aluminosilicate polymers as described in U.S. Pat. No. 5,888,711 or French Patent 2 767 128, whereby these polymers are obtained faster, more simply, and at lower cost.
The method of the invention, to prepare an imogolite-type aluminosilicate polymer, comprises the following steps:
(a) A mixed aluminium-silicon alkoxide, or a precursor of a mixed aluminium-silicon compound is treated with an aqueous alkali at a pH of between 4.5 to 6.5, keeping the molar concentration of aluminium between 5×10
−4
and 10
−2
and the Al/Si molar ratio between 1 and 3.
(b) The mixture obtained in step (a) is heated at a temperature lower than 100° C. for sufficient time for the reaction to go to completion.
(c) The residual ions are removed from the mixture obtained in step (b).
This method is characterized in that step (a) is carried out in the presence of silanol groups, and in that after step (a) and before step (b) ripening step at ambient temperature is included.
REFERENCES:
patent: 4152404 (1979-05-01), Farmer
patent: 4252779 (1981-02-01), Farmer
patent: 5888711 (1999-03-01), Poncelet et al.
patent: 5972831 (1999-10-01), Poncelet et al.
patent: 0 895 965 (1999-02-01), None
patent: 2 385 646 (1978-10-01), None
patent: 2 740 466 (1997-04-01), None
patent: 2 767 128 (1999-02-01), None
patent: 2 025 384 (1980-01-01), None
patent: 96 13459 (1996-05-01), None
S. M. Barrett et al., “The Synthesis and Characterization of Imogolite”, 1991, vol. 27, No. 7, pp. 609-612.
S. I. Wada et al., “Synthetic Allophane and Imogolite”, 1979, abstract.
Eastman Kodak Company
Ildebrando Christina
Konkol Chris P.
Silverman Stanley S.
LandOfFree
Method to prepare an aluminosilicate polymer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method to prepare an aluminosilicate polymer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method to prepare an aluminosilicate polymer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2991351