LIQUID PREPARATION FOR THE REDUCTION OF FREE OXIGEN AND THE PRESERVATION OF WATER
A preparation including a) at least one N-formal and b) at least one dialkylhydroxylamine. The preparation is preferably formulated as a concentrate. The preparation can be used (in particular in the form of the concentrate) for the reduction of free oxygen and the preservation of water, and also correspondingly additivated water. The mixture of N-formals with dialkylhydroxylamine is not only outstandingly compatible, but considerably improves the activity of dialkylhydroxylamines as oxygen scavengers.
1 . Liquid preparation which comprises
a) at least one N-formal and
b) at least one dialkylhydroxylamine of the formula RR′NOH, wherein R and R′ independently are selected from linear, branched and cyclic C 1 to C 10 alkyl groups.
2 . Preparation according to claim 1 , characterized in that the N-formal is selected from N,N′-methylenebis(5-methyloxazolidine), α,α′,α″-trimethyl-1,3,5-triazine-1,3,5-(2H,4H,6H)triethanol, 4,4-dimethyloxazolidine, dimethylolurea, 5-ethyl-3,7-dioxa-1-azabicyclo[3.3.0]octane, 2-(hydroxymethylamino)ethanol, methylenebistetrahydro-1,3-bisoxazine, N-methylolchloroacetamide, bis(hydroxymethyl)-5,5-dimethylhydantoin, diazolidinylurea, sodium hydroxymethylglycinate, 3,4,4-trimethyloxazolidine, 2,2′,2″-(hexahydro-1,3,5-triazine-1,3,5-triyl)triethanol and tetrahydro-1,3,4,6-tetrakis(hydroxymethyl)imidazo[4,5-d]imidzole-2,5-(1H,3H)dione, wherein N,N′-methylenebis(5-methyloxazolidine) is preferred.
3 . Preparation according to claim 1 , characterized in that the dialkylhydroxylamine is diethylhydroxylamine.
4 . Preparation according to claim 1 , characterized in that it additionally comprises c) at least one antioxidant selected from sterically hindered phenols, amines, vitamin E and derivatives thereof, and alkyl esters of gallic acid, preferably 3-tert-butyl-4-hydroxyanisole (BHA), 2,6-di-tert-butyl-p-cresol (BHT), 2,6-di-tert-butylphenol, lauryl gallate and vitamin E, particularly 2,6-di-tert-butylphenol and BHT.
5 . Preparation according to claim 1 , characterized in that it additionally contains d) at least one alkalizing agent.
6 . Preparation according to claim 1 , characterized in that it additionally comprises e) at least one of stabilizers, activators, corrosion inhibitors, scale inhibitors, complexing agents, fungicides, algicides, antifoams, cold stabilizers, solvents and boosters.
7 . Preparation according to claim 1 , characterized in that the weight ratio of component a) to component b) is 30:1 to 1:5, preferably 25:1 to 1:1, in particular 20:1 to 3:1, for instance 9:1.
8 . Preparation according to claim 1 , characterized in that it is present as concentrate and the fraction of component a) is at least 30% by weight, preferably at least 35% by weight, in particular at least 40% by weight, such as at least 45% by weight, for example about 50% by weight.
9 . Preparation according to claim 8 , further comprising d) at least one alkalizing agent, and the amount of alkalizing agent d) is at least 20% by weight, preferably at least 30% by weight, in particular at least 40% by weight, such as at least 45% by weight, for example about 50% by weight.
10 . Preparation according to claim 1 , characterized in that it is present as concentrate and the fraction of component b) is at least 0.25% by weight, preferably at least 1% by weight, in particular at least 2% by weight, for instance 5% by weight.
11 . Preparation according to claim 8 , characterized in that the amount of water in the concentrate is at most 30% by weight, more preferably at most 20% by weight water, particularly preferably at most 12% by weight water, in particular at most 5% by weight water, such as, for example, less than 1.0% by weight water.
12 . A method for the reduction of free oxygen in water and preservation of water comprising adding the liquid preparation of claim 1 to water.
13 . The method according to claim 12 , wherein the liquid preparation is a concentrate, and the concentrate is added to the water in an amount of 100 to 2000 ppm.
14 . Additivated water which comprises the components a) and b), and also optionally c) and/or d), of the preparation according to claim 1 , wherein the additivated water preferably has a pH of at least 7.0, more preferably at least pH 8, in particular at least pH 9, for instance pH 10.