Preparation of alkylated N- or amino, ammonium or spirobicyclic ammonium group-containing, crosslinked polymers
View Patent ↗Process for the preparation of alkylated N- or amino, ammonium or spirobicyclic ammonium group-containing, crosslinked polymer gels, which is characterized in that a) in the crosslinkage step an aqueous solution of a polymer obtained by polymerization of the corresponding monomer is adjusted to a pH of 7.5–14 at a temperature of 0 to 90° C., then the appropriate crosslinking agent is metered in and precrosslinkage is carried out with stirring and the precrosslinked polymer is transferred for complete curing to a curing container, whereupon b) the cured crude gel is cut into a defined shape, then c) washed with methanol batchwise in a static or stirred bed and directly following this d) in methanol, the alkylation is carried out, after which the alkylated gel e) is first washed batchwise by means of methanol/NaCl washes in a static or stirred bed or continuously, then f) batchwise by means of NaCl washes and final water washes with deionized water in a static or stirred bed or continuously and also a process for the preparation of the alkylators used in sted d).
1. A process for the preparation of alkylated N- or amino, ammonium or spirobicyclic or ammonium group-containing, crosslinked polymer gels, wherein
a) in the crosslinkage step an aqueous solution of a polymer provided by polymerization of the corresponding monomer is adjusted to a pH of 7.5–14 at a temperature of 0 to 90° C., then the appropriate crosslinking agent is metered in and precrosslinkage is carried out with stirring and the precrosslinked polymer is transferred for complete curing to a curing container, whereupon
b) the cured crude gel is cut into a defined shape, then
c) washed with methanol batchwise in a static or stirred bed and directly following this
d) in methanol, the alkylation is carried out by addition of one or more alkylators at a temperature from 5 to 90° C. and a pressure from 1 to 3 bar, addition of a base and optionally reprotonation, after which the alkylated gel
e) is first washed batchwise by means of methanol/NaCl washes in a static or stirred bed or continuously, then
f) batchwise by means of NaCl washes and final water washes with deionized water in a static or stirred bed or continuously.
2. The process as claimed in claim 1 , wherein in the crosslinkage in step a) the aqueous polymer solution is first adjusted to a pH of 9.5 to 10.6 in a mixing reactor at a temperature from 5 to 30° C., and then this reaction mixture is transferred to a gelling reactor and a crosslinking agent is added, whereupon the reaction mixture is precrosslinked for 10 to 120 minutes with stirring and then transfer red to a curing container for complete curing.
3. The process as claimed in claim 1 , wherein in the alkylation in step d) in each case the mixture is stirred only during and shortly after introduction of the reagents.
4. The process as claimed in claim 1 , wherein the crude gel washes in step c) and/or the methanol/sodium chloride washes in step e) are carried out in a stirring vessel or in a stirred suction filter, the solvent supply taking place from the bottom of the stirring vessel or the stirred suction filter or via the top in the stirring vessel or in the stirred suction filter and the aspiration of the used wash medium taking place via a dip tube.
5. The process as claimed in claim 1 , wherein the methanol/sodium chloride washes in step e) are carried out in a continuously operated wash column or in a wash tower or in a stirring vessel, the gel cake being present after filtration of the gel suspension as a static or stirred bed and the supply of methanol/sodium chloride solution taking place from the bottom and the aspiration taking place via a dip tube.
6. The process as claimed in claim 1 , wherein the sodium chloride washes and/or the water washes in step f) are carried out by spraying the gel bed with the washing solution or by suspension washes in a stirred suction filter or in a stirring vessel or in a continuously operated wash column.
7. The process as claimed in claim 1 , wherein in the alkylation in step d) haloalkylammonium salts are employed as alkylators, optionally in combination with bromodecane.
8. The process as claimed in claim 7 , wherein in step d) haloalkylammonium salts, prepared by reaction of trimethylamine and a dihalo-C 3 –C 24 -alkane in ethyl acetate at a temperature from −15 to 100° C. and at a pressure from 1 to 10 bar, subsequent cooling, filtration and drying, are employed as an alkylator, optionally in combination with bromodecane.
9. The process as claimed in claim 1 , wherein for the alkylation in step d) the alkylator employed is 6-bromohexyltrimethylammonium bromide, prepared by reacting trimethylamine and 1,6-dibromohexane in ethyl acetate at a temperature from −15 to 100° C. and at a pressure from 1 to 10 bar, whereupon the reaction mixture is cooled after 5 to 15 hours and filtered and the haloalkylammonium salt thus obtained is dried, and said alkylator employed optionally in combination with bromodecane.
10. A process for the preparation of alkylated N- or amino, ammonium or spirobicyclic or ammonium group-containing, crosslinked polymer gels, which comprises washing a gelled and cut crude gel provided by polymerization and crosslinkage
a) in a stirring vessel or in a stirred suction filter with methanol, the solvent supply taking place from the bottom of the stirring vessel or the stirred suction filter or via the top in the stirring vessel or in the stirred suction filter and the aspiration of the used wash medium taking place via a dip tube and
b) the crude gel washed in this way being alkylated with an alkylator following this, whereupon
c) a methanol/sodium chloride wash is carried out in a continuously operated wash column or in a wash tower or stirring vessel, the gel cake being present after filtration of the gel suspension as a static or stirred bed and the supply of methanol/sodium chloride solution taking place from the bottom and the aspiration taking place via a dip tube, and then
d) a sodium chloride wash and a water wash is carried out by spraying the gel bed with the washing solution or by suspension washes in a stirred suction filter or in a stirring vessel or in a continuously operated wash column.