Nonwoven wipe impregnating composition

DETAILED DESCRIPTION OF THE INVENTION INCLUDING THE PREFERRED EMBODIMENTS The aqueous composition of the invention is employed as an impregnant for flexible absorbent nonwoven fabrics in the manufacture of moist wipes useful for cleaning and/or delivering active agents to animate or inanimate surfaces.
The aqueous composition is comprised of water having dissolved therein a preservative system specifically adapted to prevent microbial deterioration of the moist wipe, which is readily susceptible to microbial deterioration in the absence of a suitable preservative.
The preservative system is comprised of potassium sorbate, disodium ethylenediaminetetraacetate (disodium EDTA), a cationic biocide selected from two specific agents described more fully hereinbelow and citric acid.
The potassium sorbate is employed in the aqueous composition at a concentration of from about 0.
02 to about 0.
25 percent by weight of the aqueous composition.
The antimicrobial effect contributed by the sorbate is due primarily to sorbic acid to which the sorbate is converted in situ at the pH level employed in the aqueous composition as discussed hereinbelow.
The disodium ethylenediaminetetraacetate enhances the effect of the preservative system.
It is employed at a concentration of from about 0.
02 to about 0.
20 percent by weight of the composition.
The cationic biocide is selected from polyhexamethylene biguanide hydrochloride and poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichloride].
Polyhexamethylene biguanide hydrochloride is a known biocide with a wide spectrum of antimicrobial activity and is commercially available as a 20% w/w aqueous solution from ICI Americas Inc.
, Wilmington Del.
under the tradename COSMOCIL CQ.
It can be represented by the general formula: ##STR1## in which n has an average value such that the molecular weight is 1000-1400.
Poly[oxyethylene(dimethyliminio)ethylene(dimethyliminio)ethylene dichlorid e] is a known broad spectrum microbiocide and is commercially available as a 60% aqueous concentrate from Buckman Laboratories, Inc