U.S. Pat. No. 5,310,508 (508) discloses ethoxylated alkyl glyceryl ether sulfonates for use in personal care compositions. Particularly useful molecules were those having alkyl groups of twelve to fifteen carbon atoms, inclusive and those molecules with an average number of ethoxies of 1, 2 or 3, "n number", most specifically an average value of n equal to 1. In 508, incorporated by reference herein, the general distribution of an ethoxylated alkyl glyceryl ether sulfonate with an average value of n is 1 is provided showing the various quantity of components having n as a value of zero, 1, 2, 3, 4, 5, 6 etc. There is no indication of the members of the distribution effect on activity, mildness, lathering, ease of preparation or any other function.
It has now been discovered that the quantity of the particular number of ethoxy groups has a marked effect in the value of ethoxylated alkyl glyceryl ether sulfonates as a surfactant. The particular distribution of the ethoxylated moieties making up a value equal to average value of 1 or 2, preferably 1, should maximize the value of n is one or 2 while minimizing the quantity of any material with an n value of over three. The component where n is zero remains a significant contributor to the performance of the overall composition since a low average n value, one or two preferably one, generally requires a significant amount of n is zero component. However, the negative contribution of the higher ethoxylated moieties, n greater than three, was unexpected and not predictable. Still further, the alkyl group is preferably straight chain as opposed to branched. The average number of ethoxyl groups as well as the number of ethoxyl groups having a value of four or more can have a clear bearing on lathering, as well as on the processability of the material into a shaped solid composition useful for personal care, such as a bar. This is particularly accentuated when a free fatty acid is also present. While using ordinary bar making equipment even ethoxy alkyl glyceryl ether sulfonates with an average value of 2 ethoxy groups encountered substantial difficulty being made into bars because of the inability to shape and/or release the bar at an acceptable rate from ordinary manufacturing equipment.
USPTO Backgrounds
USPTO Backgrounds