Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Nitrogen-containing reactant
Reexamination Certificate
1999-09-03
2001-01-30
Hampton-Hightower, P. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Nitrogen-containing reactant
C528S480000, C528S482000, C528S488000, C528S495000, C528S499000, C528S50200C, C528S50200C, C528S50200C, C525S328200, C525S359100, C525S359300, C525S359500, C525S366000, C526S310000
Reexamination Certificate
active
06180754
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to reduced salt polyallylamine polymer compositions, a process for producing a cross-linked polyallylamine polymer from a reduced salt, aqueous solution of a polyallylamine polymer and a multifunctional cross-linking agent and to cross-linked polyallylamine polymer compositions produced thereby.
BACKGROUND OF THE INVENTION
Cross-linked polyallylamine polymers have found many therapeutic applications. See for example, WO 98/57652, JP 07309766-A and U.S. Pat. Nos. 5,618,530, 5,679,717, 5,693,675 and 5,607,669 for reducing blood cholesterol levels by reducing reabsorption of bile acids, U.S. Pat. No. 5,702,696 for decreasing the absorption of dietary iron from the gastrointestinal track, and WO 96/21454 and U.S. Pat. No. 5,496,545 for removing phosphate from the gastrointestinal track. Further, JP 05244915 discloses the use of cross-linked polyamine polymers as a food preservative.
Methods to produce cross-linked polyamine polymers are known. See for example, the references cited hereinabove and U.S. Pat. No. 4,605,701, DE 4227019 A1 and EP 732352 A1. These references disclose cross-linking the polyallylamine polymer by reacting the polymer with a suitable cross-linking agent in aqueous caustic solution or an aqueous caustic solution and immiscible solvent mixture.
The existing methods to produce cross-linked polyamine polymers create difficult and costly handling and cleanup procedures, especially in an industrial production process. For example in U.S. Pat. Nos. 5,618,530, 5,679,717, 5,693,675, 5,702,696 and 5,607,669 the cross-linked polyallylamine forms a continuous mass within the reaction vessel after it congeals which is impractical on a large scale. Further, when the cross-linking reaction occurs in a basic aqueous solution the removal of undesirable impurities, such as salts, e.g., sodium chloride, as well as unreacted allylamine monomer, low molecular weight polyallylamine polymer, low molecular weight compounds from initiator degradation during and after the free-radical polymerization of the allylamine monomer, solvents, etc., is very complicated as it must be performed on the solid, insoluble, cross-linked polyallylamine polymer. Moreover, when using a basic aqueous solution and dispersion solvent mixture, such as disclosed in WO 98/57652, the solvent, e.g., acetonitrile, must be reclaimed or disposed of. The present invention addresses these problems and gives a more practical solution to them.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a process for producing a cross-linked polyallylamine polymer comprising the steps of reacting a reduced salt, aqueous solution of a polyallylamine polymer with a multifunctional cross-linking agent, preferably epichlorohydrin, to give a cross-linked polyallylamine polymer.
One embodiment of the present invention comprises the step of neutralizing an aqueous solution of a polyallylamine acid salt polymer, preferably polyallylamine hydrochloride polymer, by ion exchange or electrodeionization, to give a reduced salt, aqueous solution of polyallylamine polymer.
In a further embodiment, the present invention comprises the step of nanofiltering or ultrafiltering a neutralized, aqueous solution of a polyallylamine polymer to yield a reduced salt, aqueous solution of polyallylamine polymer.
In yet a further embodiment, the present invention involves the composition of a reduced salt, aqueous solution of polyallylamine polymer produced by the foregoing steps.
In yet a further embodiment, the present invention comprises the step of concentrating a reduced salt, aqueous solution of polyallylamine polymer prior to cross-linking.
In yet a further embodiment, the present invention comprises the step of washing the cross-linked polyallylamine polymer with an alcohol or alcohol/water solution.
In yet a further embodiment, the present invention comprises the step of drying the cross-linked polyallylamine polymer.
In yet a further embodiment, the present invention involves the use of a reactor designed for high viscosity processing, preferably a LIST reactor, in the cross-linking and/or drying steps.
In yet a further embodiment, the present invention involves compositions of cross-linked polyallylamine polymers produced by the foregoing process.
REFERENCES:
patent: 4528347 (1985-07-01), Harada et al.
patent: 4540760 (1985-09-01), Harada et al.
patent: 4605701 (1986-08-01), Harada et al.
patent: 4885247 (1989-12-01), Datta
patent: 5496545 (1996-03-01), Holmes-Farley et al.
patent: 5607669 (1997-03-01), Mandeville, III et al.
patent: 5618530 (1997-04-01), Mandeville, III et al.
patent: 5679717 (1997-10-01), Mandeville, III et al.
patent: 5693675 (1997-12-01), Mandeville, III et al.
patent: 5702696 (1997-12-01), Mandeville, III et al.
patent: 4227019 A1 (1994-02-01), None
patent: 732352 A1 (1996-09-01), None
patent: 05244915 (1993-09-01), None
patent: 07309766 (1995-11-01), None
patent: WO 96/21454 (1996-07-01), None
patent: WO 98/57652 (1998-12-01), None
Encyclopedia of Polymer Science and Engineering, 1988, vol. 8, pp. 341-393.
Chang, J. App. Electrochem, 9, 731-736 (1979).
J. D. McLean, V. A. Stenger, R. E. Reim, M. W. Long and T. A. Hiller, Anal. Chem., 50, 1309 (1978).
Encyclopedia of Polymer Science and Engineering, 1988, vol. 17, pp. 75-107.
Voss, J. Membrane Sci., 27, 165-171 (1986).
Hwang and Kammermeyer, Techniques of Chemistry, Wiley, vol. VII, 494 (1975).
Kiekhaefer Russ L.
Stutts Kenneth J.
Hampton-Hightower P.
The Dow Chemical Company
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