Process for chelating and inhibiting scale in aqueous systems
AssigneePetrolite Corporation
InventorPatrick M. Quinlan
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Abstract
Methylene phosphonates of polyalkylenepolyamines polymerized with chain extenders such as epoxyhalides, dihalides, etc., such as epihalohydrin, alkylenedihalide, alkenylenedihalide, alkynylenedihalide, xylylenedihalide, alkyleneetherdihalides, etc.; and to uses therefor, particularly as scale inhibitors, chelating agents, etc.
Claims12
A process of inhibiting scale in a commercial water system containing as scale forming compounds calcium, barium and magnesium carbonate, sulfate, silicate, oxalate, phosphate, hydroxide or fluoride which comprises adding to said system an effective amount of a methylene phosphonate polymer selected from the group consisting of soluble or dispersible polyalkylenepolyamine-epihalohydrin polymers and polyalkylenepolyamine-dihalide compound polymers, said dihalide compound being an alkylene ether dihalide compound or an unsaturated dihalide, said methylene phosphonate polymer having nitrogen-bonded methylene phosphonate units of the formula
- --CH.sub.2 PO(OM).sub.2
- where M is alkali metal, alkaline earth metal, hydrogen, alkyl ammonium or ammonium, the terminal nitrogen atoms of said methylene phosphonate polymers having no more than one methylene phosphonate group attached thereto, the remaining valence of the terminal nitrogen atom having attached thereto the group ##STR29## a divalent aliphatic ether radical, or a divalent unsaturated aliphatic radical.
A process of chelating metal cations, including ferrous cations, from aqueous systems which comprises adding to said aqueous system an effective amount of a methylene phosphonate polymer selected from the group consisting of soluble or dispersible polyalkyleneamine-epihalohydrin polymers and polyalkyleneamine-dihalide compound polymers, said dihalide compound being an alkylene ether dihalide compound or an unsaturated dihalide, said methylene phosphonate polymer having nitrogen-bonded methylene phosphonate units of the formula
- --CH.sub.2 PO(MO).sub.2
- where M is alkali metal, alkaline earth metal, hydrogen alkyl ammonium or ammonium, the terminal nitrogen atoms of said methylene phosphonate polymers having no more than one methylene phosphonate group attached thereto, the remaining valence of the terminal nitrogen atom having attached thereto the group ##STR32## a divalent aliphatic ether radical, or a divalent unsaturated aliphatic radical.
Dependencies are inferred from the claim text.