Patent ID: 6641828
Filing Date: 2003-11-04
Classification: A01N,C02F,Y02W

Abstract:
A method of providing microbiological control in an aqueous medium and/or eradication or reduction of biofilm on a surface in contact with such aqueous medium, which method comprises introducing into the aqueous medium a microbiocidally effective amount of at least one 1,3-dibromo-5,5-dialkylhydantoin in which one of the alkyl groups in the 5-position is a methyl group and in which the other alkyl group in the 5-position has in the range of 1 to 4 carbon atoms, wherein (i) the molar quantity of said at least one 1,3-dibromo-5,5-dialkylhydantoin introduced into said aqueous medium is less than the molar quantity of N,Nâ€²-bromochloro-5,5-dimethylhydantoin that would be required to effect the same degree of microbiological control in said medium, (ii) the quantity of said at least one 1,3-dibromo-5,5-dialkylhydantoin introduced into said aqueous medium releases an amount of â€œfree chlorineâ€  that is greater than the amount of â€œfree chlorineâ€  that would be released in said medium by an equimolar quantity of N,Nâ€²-bromochloro-5,5-dimethylhydantoin, and (iii) the amount of â€œfree chlorineâ€  released by the quantity of said at least one 1,3-dibromo-5,5-dialkylhydantoin introduced into said medium is greater than the amount of â€œfree chlorineâ€  that could be predicted to he released by that quantity of said at least one 1,3-dibromo-5,5-dialkylhydantoin on the basis of the amount of â€œfree chlorineâ€  that would be released in said medium by an equimolar quantity of N,Nâ€²-bromochloro-5,5-dimethylhydantoin.