Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2000-03-08
2001-04-10
Ogden, Necholus (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S155000, C510S156000, C510S447000
Reexamination Certificate
active
06214780
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to synthetic soap bar compositions comprising amphoteric surfactants (i.e., for enhanced mildness) which surprisingly can be readily processed, even at relatively high levels of amphoteric (i.e., above 1%). Processability is measured as enhanced throughput, measured as bars plod in pounds per minute. Specifically, the invention relates to bar compositions comprising anionic (e.g., acyl isethionate), amphoteric and fatty acid soap (introduced as a mixture of various chain length fatty acid soaps or as a single chain length soap) wherein amphoteric-containing bars (normally extremely difficult to extrude when used at levels above 1% by weight) are readily processed by using minimal levels of fatty acid soap and minimal ratios of saturated to unsaturated soap.
BACKGROUND
Traditionally, soap has been used as a skin cleanser. While soap is low in cost, easy to manufacture and lathers well, it is also very harsh on skin.
In order to alleviate the harshness of soap, synthetic bars have been used in which much of the soap is replaced with milder surfactants, e.g., acyl isethionates. Patents relating to the use of acyl isethionate and soap, therefore, are known (see U.S. Pat. No. 2.894,912 to Geitz).
It is also known to make bars which are even milder by replacing soap, isethionate or fatty acid (used primarily as structurant) with very mild surfactants such as amphoteric surfactants. Normally, however, it is extremely difficult to successfully and economically process bars containing both mild anionics and amphoterics (e.g., betaine).
U.S. Pat. No. 5,372,751 to Rys-Cicciari et al. does teach bar compositions comprising anionic (e.g., acyl isethionate) and betaine. The reference notes at several points that soap is preferably absent (column 6, lines 60-61; column 9, line 47) and this is confirmed by examples where soap is never used in amounts greater than 2%. While the reference suggests this is done for reasons of mildness, applicants have also previously never been able to process amounts of betaine above 1% at these low levels of soap.
Unexpectedly, applicants have found that when minimal levels of fatty acid soap (e.g., 3% and up) are used in bars comprising an anionic surfactant system, much greater levels of amphoteric (2% and up) can be readily processed than previous possible.
Applicants have further discovered that when the total content of saturated soap to unsaturated soap is greater than 1:1, process benefits (e.g., rate of plodding) are enhanced yet further. At the same time, the ability to successfully process more betaine allows introduction of much greater mildness benefit.
BRIEF SUMMARY OF THE INVENTION
In one embodiment of the invention, the invention relates to bar compositions comprising:
(a) 10% to 70% anionic surfactant (e.g., fatty acyl isethionate);
(b) 2% to 15%, preferably 2% to 10%, more preferably 3% to 8% amphoteric surfactant;
(c) 3% to 25%, preferably 5% to 15% of a fatty acid soap comprising a mixture of C
6
to C
24
fatty acids or a single C
6
to C
24
fatty acid soap;
wherein ratio of saturated fatty acid soap to unsaturated fatty acid soap is greater than 1:1, preferably greater than 2:1, preferably greater than 5:1 and more preferably greater than 10:1. Indeed, the fatty acid “mixture” of fatty acids may comprise 100% saturated fatty acids (i.e., no unsaturated fatty acids at all).
That is, by ensuring minimum levels of soap (3% and up) and minimum levels of saturated fatty acid, strong processing benefits (e.g., enhanced plodding rates) are achieved. Without minimum soap levels only very low levels of amphoteric (i.e., about 1% or less) can be efficiently processed and plodded. Minimum levels of saturation enhances plodding rates and zein rates even further.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to synthetic based (e.g., anionic based) soap bar compositions comprising amphoteric surfactants (and/or zwitterionic surfactants) wherein, based on minimum levels of soap (i.e., 3% and up), it has become unexpectedly possible to efficiently process much greater amounts of said amphoteric and/or zwitterionic surfactant than previously possible.
That is, although the benefit of using amphoteric/zwitterionic surfactant has been previously recognized (e.g., for enhanced mildness), these surfactants make the products soft and sticky. Thus, it has been difficult to process (i.e., stamp and extrude) synthetic bars containing such surfactants. Unexpectedly, applicants have discovered that one reason the processing may have been so difficult is because such amphoteric/zwitterionics have been previously used in synthetic bars substantially free of soap (i.e., having about 2% or less soap). Unexpectedly, however, applicants have found if the amphoteric/zwitterionic is used in a synthetic structured bar wherein the level of soap is about 3% and up (i.e., a 3% to 25% soap), the zwitterionic/amphoteric becomes much more readily processable. Thus, it now becomes possible to use much greater quantities of zwitterionic/amphoteric than previously possible while processing at efficient/economic rates (e.g., greater than 5 lbs./minute based on a pilot plant extruder).
In a second embodiment, applicants have found that increasing the level of saturated to unsaturated fatty acid increases processing even further. Specifically, where levels of saturates to unsaturates is greater than 1:1, enhanced processing is achieved.
Specific components of the invention are discussed in greater detail below.
Anionic
The bar compositions of the invention comprise 10% to 70% anionic surfactant or mixture of anionic surfactants.
Preferably, the bar compositions comprise about 10% to 70% by weight fatty acyl isethionate.
The acyl isethionate, if used, has the formula:
RCO
2
CH
2
CH
2
SO
3
M
wherein R is alkyl or alkenyl group of 6 to 21 carbons and M is a solubilizing cation such as sodium, potassium, ammonium or substituted ammonium.
These esters are generally prepared by the reaction between alkali metal isethionate and mixed aliphatic fatty acids having from, for example, 6 to 18 carbons and iodine value of less than 20.
The anionic surfactant may also be an ether sulphate of the formula
R
1
O(CH
2
CH
2
O)
y
SO
3
M
where R
1
is alkyl or alkenyl of 8 to 18 carbon atoms, especially 11 to 15 carbon atoms, y has an average value of at least 1.0 and M is a solubilizing cation such as sodium, potassium, ammonium or substituted ammonium. Preferably y has an average value of 2 or more.
Other anionic detergents may be used. Possibilities include alkyl glyceryl ether sulphates, sulphosuccinates, taurates, sarcosinates, sulphoacetates, alkyl phosphates and acyl lactates. Sulphosuccinates may be monoalkyl sulphosuccinates having the formula:
R
2
O
2
CCH
2
CH(SO
3
M)CO
2
M;
and amido-MEA sulphosuccinates of the formula:
R
2
CONHCH
2
CH
2
O
2
CCH
2
CH(SO
3
M)CO
2
M;
wherein R
2
ranges from C
8
-C
20
alkyl, preferably C
12
-C
15
alkyl and M is a solubilizing cation.
Sarcosinates are generally indicated by the formula
R
3
CON(CH
3
)CH
2
CO
2
M,
wherein R
3
ranges from C
8
-C
20
alkyl, preferably C
12
-C
15
alkyl and M is a solubilizing cation.
Taurates are generally identified by the formula R
5
CONR
6
CH
2
CH
2
SO
3
M, wherein R
5
ranges from C
8
-C
20
alkyl, preferably C
12
-C
15
alkyl, R
6
ranges from C
1
-C
4
alkyl, and M is a solubilizing cation.
Mildness Enhancing Surfactant
The second component of the bar composition of the invention is a mildness enhancing surfactant which may be a zwitterionic surfactant, amphoteric surfactant or mixtures thereof.
Zwitterionic surfactants are exemplified by those which can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radicals can be straight or branched chain, and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. A general formula for these compounds i
Corr James
Narath William
Ornoski Gregory
Koatz Ronald A.
Lever Brothers Company Division of Conopco, Inc.
Ogden Necholus
LandOfFree
Enhanced processing of synthetic bar compositions comprising... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Enhanced processing of synthetic bar compositions comprising..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Enhanced processing of synthetic bar compositions comprising... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2435164