Colloid systems and wetting agents; subcombinations thereof; pro – Continuous liquid or supercritical phase: colloid systems;... – Having discontinuous gas or vapor phase – e.g. – foam:
Reexamination Certificate
1999-12-07
2003-05-13
Metzmaier, Daniel S. (Department: 1712)
Colloid systems and wetting agents; subcombinations thereof; pro
Continuous liquid or supercritical phase: colloid systems;...
Having discontinuous gas or vapor phase, e.g., foam:
C516S063000, C516S909000, C516S912000, C516S062000, C554S049000, C554S069000, C554S090000, C554S092000, C510S156000, C510S494000, C510S495000
Reexamination Certificate
active
06562874
ABSTRACT:
The present invention relates to anionic starting materials/surfactants, particularly those which are prepared from the direct esterification of fatty acids and isethionate (i.e., directly esterified fatty acyl isethionate or “DEFI”) and which may be used in personal wash compositions such as, for example, personal wash bars or personal wash shower gel compositions. Specifically, the invention relates to compositions comprising mixtures of DEFI and modified DEFI compounds. The modified DEFI compounds are compounds made in the same DEFI reactor where DEFI is made (from reaction of fatty acid and isethionate) except that the fatty acid is substituted and reacted with isethionate and/or the isethionate is substituted and reacted with fatty acid. As noted, the mixtures may also comprise compounds where the fatty acid substitute and isethionate substitute may react with each other.
BACKGROUND
In personal wash compositions (e.g., bars or liquids), one very common anionic surfactant which is used is acyl isethionate. This compound is milder than soap, yet retains characteristics which consumers associate with good cleaning (e.g., foaming). It would be greatly beneficial to find compounds which are still milder and/or less drying than fatty acid isethionates, while maintaining good foaming profiles. Further, when used in bar preparation, such compounds should be suitable for bar processing conditions.
The acyl isethionate surfactant is commonly produced by the direct esterification of a fatty acid (e.g., C
10
to C
16
fatty acid such as lauric fatty acid) and isethionate (e.g., OHCH
2
CH
2
SO
3
−
Na
+
) in a process commonly known as the “DEFI” process (process for making directly esterified fatty acid isethionate). The DEFI process is conducted in a single DEFI reactor.
Applicants have now discovered that, if either the fatty acid starting component is partially replaced (e.g., with silicone based carboxylic acids, fatty acids derived from Neem oil or castor oil of varying chain distribution, dicarboxylic acids, etc.); and/or the isethionate starting component is partially replaced (e.g., with glycerol, sorbitol, pentaerythritol, amines etc.), not only will the DEFI reactor form the expected directly esterified fatty acid isethionate (from the fatty acid and isethionate which are not partially replaced), but a portion of the final reaction component will also represent combinations of, for example, isethionates modified by the different types of fatty acids (when the standard fatty acid is partially replaced), or alcohol esters or amides (when the isethionate is partially replaced). The cosurfactants produced during the production of the main active (e.g., sodium lauroyl or sodium cocoyl isethionate) are mild and result in milder surfactant mixtures.
That is, the same DEFI reactor will produce mixtures of “standard” fatty acid isethionate and these “modified” DEFI compounds. Applicants are aware of no prior art which teaches or suggests that mixtures of standard and modified DEFI can be produced in the same reactor, let alone that at least some of these mixtures may provide enhanced mildness without sacrificing foaming. It should be noted that a small part of the mixture may also comprise compounds formed by fatty acid replacement reacting with isethionate replacement.
U.S. Pat. No. 5,300,666 to Imperante et al., teaches a process for condensing silicone carboxylates with sodium isethionate under conditions similar to the “DEFI” process (the reaction time of the reference is 5-15 hours versus 90 minutes for standard DEFI reaction; same temperatures of 220-240) to produce high foaming, mild surfactants. This reaction, however produces only a single “modified” DEFI compound. It does not produce mixtures of “standard” and modified DEFI in a single reactor. Further, it teaches only the replacement of standard (e.g., lauric) fatty acid with a silicone based carboxylic acid and fails to teach or suggest the many other possible fatty acid replacements of the subject invention. It also fails to teach that the isethionate portion may be replaced instead of or, in addition to the fatty acid portion. Finally, the process involves longer reaction times than those of the subject invention, 5 to 15 hours versus 90 minutes.
Other references also teach compounds which could be the “modified” DEFI component of the subject invention. U.S. Pat. No. 4,476,055 to Du Vernet, for example, teaches C
21
dicarboxylic acid isethionates as anionic surfactants; Schmidt et al., in “A Novel Dianionic Surfactant from the Reaction of C
14
-Alkenylsuccinic Anhydric with Sodium Isethionate”, JAOCS, 71 (7):695-703 (1994) teach an isethionate reacted with C
14
alkenyl succinic acid; and Bistline et al., in “Surface Active Agents from Isopropenyl Esters: Acylation of Isethionic Acid and N-Methyltaurine”, JAOCS 48 (11): 657-60 (1971) teach another isethionate based surfactant made using DEFI-like conditions (e.g. high temperature and acidic catalysts).
Other references teach isethionate-based surfactants made under high temperature and basic catalysts (see, e.g., DE 4,337,035 to Henkel (1995); DE 4,315,810 to Henkel (1994); DE 1,234,708 to General Aniline and Corp. (1967); U.S. Pat. No. 5,296,627 to Tang et al. (assigned to PPG Industries) or JP 04,360,863 to Tosoh Corp. (1992)).
Again, none of these references teach or suggest mixtures of standard DEFI with the modified DEFI produced in the same reactor by at least partially replacing the standard fatty acid and/or isethionate. Further, none of these references teach or suggest that such mixtures may be milder than DEFI alone while maintaining a strong foaming profile.
BRIEF DESCRIPTION OF THE INVENTION
Suddenly and unexpectedly, applicants have discovered new compositions wherein said compositions comprise mixtures of “standard” DEFI (made from reaction of isethionate with C8 to C22 straight chain substantially saturated (preferably greater than 85% saturated) monocarboxylic fatty acids (it should be noted that in mixtures such as “coco” fatty acid, there may be some small percentage of unsaturated fatty acid such as, for example, oleic fatty acid) and DEFIs which have been modified by partially replacing (1-80%, preferably 10-50%, most preferably 10-35%) the fatty acid and/or the isethionate in the reactor so that the replacing material reacts with the fatty acid or isethionate to produce the modified DEFI.
More specifically, the compositions comprise mixtures of:
(a) “standard” DEFI (Isethionate reacted with C
8
-C
22
, preferably C
10
-C
16
straight chain substantially saturated non-carboxylic acid); and
(b) a DEFI produced by either reacting C
8
-C
22
fatty acid with a replacement polyol (e.g., glycerol, sorbitol, pentaerythritol or almost any compound with available OH group), organic acid, or amine or mixtures thereof; or reacting isethionate with a replacement fatty acid (e.g., silicone based carboxylic acid, multicarboxylic fatty acid derived from Neem oil or castor oil of varying chain distribution, dicarboxylic acids).
In a second embodiment of the invention, the invention comprises a process for making a mixture of “standard” DEFI and “modified” DEFI in a single reactor which process comprises: mixing:
(i) about 20 to 50% by wt., preferably 25% to 40% by wt., alkali metal isethionate;
(ii) about 35% to 75% by wt., preferably 45% to 65% by wt. C
8
-C
22
straight chain fatty acid;
(iii) about 0 to 20% by wt., preferably 0.1 to 18% by wt. replacement for alkali metal isethionate; and
(iv) about 0% to 10% by wt., preferably 0.1 to 9% by wt. replacement for C
8
-C
22
straight chain fatty acid;
at a temperature of 180 to 240° C.
wherein an acid catalyst is used; (e.g., zinc oxide, zinc isethionate, or any Lewis acid);
wherein (i) and (ii) and at least one of (iii) or (iv) must be mixed in the reactor.
It should be noted that “replacement” reactants may be combined at the beginning of the reaction or that they may be used at some point after compounds (i) and (ii) have been reacting for awhile (e.g., 5 minutes to 60 minutes).
DETAILED DESCRIPTION O
Gallagher Lee Ann
Ilardi Leonora
Massaro Michael
Koatz Ronald A.
Metzmaier Daniel S.
Unilever Home & Personal Care USA , division of Conopco, Inc.
LandOfFree
Compositions comprising combination of DEFI and modified... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Compositions comprising combination of DEFI and modified..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Compositions comprising combination of DEFI and modified... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3073669