Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2000-04-10
2002-09-10
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...
C510S424000, C510S426000, C510S428000, C568S458000, C560S076000
Reexamination Certificate
active
06448213
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to mixed surfactant systems useful in laundry and cleaning compositions, especially granular and liquid detergent compositions, comprising mid-chain branched primary alkyl sulfate surfactants, alkyl benzene sulfonate surfactants and cationic surfactants within select relative proportions.
BACKGROUND OF THE INVENTION
Conventional detersive surfactants comprise molecules having a water-solubilizing substituent (hydrophilic group) and an oleophilic substituent (hydrophobic group). Such surfactants typically comprise hydrophilic groups such as carboxylate, sulfate, sulfonate, amine oxide, polyoxyethylene, and the like, attached to an alkyl, alkenyl or alkaryl hydrophobe usually containing from about 10 to about 20 carbon atoms. Accordingly, the manufacturer of such surfactants must have access to a source of hydrophobe groups to which the desired hydrophile can be attached by chemical means. The earliest source of hydrophobe groups comprised the natural fats and oils, which were converted into soaps (i.e., carboxylate hydrophile) by saponification with base. Coconut oil and palm oil are still used to manufacture soap, as well as to manufacture the alkyl sulfate (“AS”) class of surfactants. Other hydrophobes are available from petrochemicals, including alkylated benzene which is used to manufacture alkyl benzene sulfonate surfactants (“LAS”).
More recently, it has been discovered that certain relatively long-chain alkyl sulfate compositions containing mid-chain branching are preferred for use in laundry products, especially under cool or cold water washing conditions (e.g., 20° C.-5° C.). These mid-chain branched primary alkyl sulfate surfactants, which provide a surfactant mixture that is higher in surfactancy and has better low temperature water solubility than linear alkyl sulfate, can be suitably combined with one or more other traditional detergent surfactants (e.g., other primary alkyl sulfates; linear alkyl benzene sulfonates; alkyl ethoxylated sulfates; nonionic surfactants; etc.) to provide improved surfactant systems. However, it has been determined that such surfactant systems containing higher levels of linear alkyl benzene sulfonates (higher than about 20% by weight of the mixture of alkyl benzene sulfonate and mid-chain branched alkyl sulfate) are not optimized in cleaning performance.
It has been surprisingly determined that cleaning performance of surfactant systems comprising these mid-chain branched primary alkyl sulfate surfactants having greater than 14.5 carbon atoms in combination with higher levels of linear alkyl benzene sulfonate surfactant can be further improved by including low levels of cationic surfactant in these surfactant systems.
BACKGROUND ART
U.S. Pat. No. 3,480,556 to deWitt, et al., Nov. 25, 1969, EP 439,316, published by Jul. 31, 1991, and EP 684,300, published Nov. 29, 1995, EP 439,316, and U.S. Pat. Nos. 5,245,072, 5,284,989, 5,026,933, 3,480,556 and 4,870,038. R. G. Laughlin in “The Aqueous Phase Behavior of Surfactants”. Academic Press, N.Y. (1994) p. 347. See also Finger et al., “Detergent alcohols—the effect of alcohol structure and molecular weight on surfactant properties”, J. Amer. Oil Chemists' Society, Vol. 44, p. 525 (1967) and Technical Bulletin, Shell Chemical Co., SC: 364-80, EP 342,917 A, Unilever, published Nov. 23, 1989 U.S. Pat. No. 4,102,823 and GB 1,399,966, G.B. Patent 1,299,966, Matheson et al., published Jul. 2, 1975, EP 401,462 A, assigned to Henkel, published Dec. 12, 1990. See also K. R. Wormuth and S. Zushma, Langmuir, Vol. 7, (1991), pp 2048-2053, R. Varadaraj et al., J. Phys. Chem., Vol. 95, (1991), pp 1671, Varadaraj et al., J. Colloid and Interface Sci., Vol. 140, (1990), pp 31-34, and Varadaraj et al., Langmuir, Vol. 6 (1990), pp 1376-1378.
“Linear Guerbet” alcohols are available from Henkel, e.g., EUTANOL G-16.
See also: Surfactant Science Series, Marcel Dekker, N.Y. (various volumes include those entitled “Anionic Surfactants” and “Surfactant Biodegradation”, the latter by R. D. Swisher, Second Edition, publ. 1987 as Vol. 18; see especially p.20-24 “Hydrophobic groups and their sources”; pp 28-29 “Alcohols”, pp 34-35 “Primary Alkyl Sulfates” and pp 35-36 “Secondary Alkyl Sulfates”); and CEH Marketing Research Report “Detergent Alcohols” by R. F. Modler et al., Chemical Economics Handbook, 1993, 609.5000-609.5002; Kirk Othmer's Encyclopedia of Chemical Technology, 4th Edition, Wiley, N.Y., 1991, “Alcohols, Higher Aliphatic” in Vol. 1, pp 865-913 and references therein.
SUMMARY OF THE INVENTION
The present invention relates to cleaning compositions comprising surfactant systems which comprise:
(a) from about 80% to about 99% (preferably from about 85% to about 99%, more preferably from about 90% to about 99%, and most preferably from about 92% to about 98%) by weight of an anionic cosurfactant mixture of mid-chain branched primary alkyl sulfates and linear alkyl benzene sulfonates, wherein said mixture comprises:
(i) from about 35% to about 80%, by weight of this anionic cosurfactant mixture, of mid-chain branched primary alkyl sulfates having the formula:
wherein the total number of carbon atoms in the branched primary alkyl moiety of this formula (including the R, R
1
, and R
2
branching) is from 14 to 20, and wherein further for this surfactant mixture the average total number of carbon atoms in the branched primary alkyl moieties having the above formula is within the range of greater than 14.5 to about 18 (preferably greater than 14.5 to about 17.5. more preferably from about 15 to about 17); R, R
1
, and R
2
are each independently selected from hydrogen and C
1
-C
3
alkyl (preferably methyl), provided R, R
1
, and R
2
are not all hydrogen and, when z is 1, at least R or R
1
is not hydrogen; M is one or more cations; w is an integer from 0 to 13; x is an integer from 0 to 13; y is an integer from 0 to 13; z is an integer of at least 1; and w+x+y+z is from 8 to 14 (preferably less than about 80% of the alkyl sulfates have a total of 18 carbon atoms in the alkyl chain); and
(ii) from about 20% to about 65%, by weight of this anionic cosurfactant mixture, of C
10
-C
16
linear alkyl benzene sulfonate; and
(b) from about 1% to about 20% (preferably from about 1% to about 15%, more preferably from about 1% to about 10%, and most preferably from about 2% to about 8%) of one or more cationic cosurfactants, preferably C
8
-C
14
cationic cosurfactants.
These cleaning compositions preferably comprise from about 0.1% to about 99.9% (preferably from about 1% to about 50%) by weight of the surfactant system and from about 0.1% to about 99.9% (preferably from about 1% to about 50%) by weight of one or more cleaning composition adjunct ingredients.
Preferably, these cleaning compositions comprise a mixture of mid-chain branched primary alkyl sulfate surfactants, wherein said mixture comprises at least about 5% by weight of two or more mid-chain branched alkyl sulfates having the formula:
or mixtures thereof; wherein M represents one or more cations; a, b, d, and e are integers, a+b is from 10 to 16, d+e is from 8 to 14 and wherein further
when a+b=10, a is an integer from 2 to 9 and b is an integer from 1 to 8;
when a+b=11, a is an integer from 2 to 10 and b is an integer from 1 to 9;
when a+b=12, a is an integer from 2 to 11 and b is an integer from 1 to 10;
when a+b=13, a is an integer from 2 to 12 and b is an integer from 1 to 11;
when a+b=14, a is an integer from 2 to 13 and b is an integer from 1 to 12;
when a+b=15, a is an integer from 2 to 14 and b is an integer from 1 to 13;
when a+b=16, a is an integer from 2 to 15 and b is an integer from 1 to 14;
when d+e=8, d is an integer from 2 to 7 and b is an integer from 1 to 6;
when d+e=9, d is an integer from 2 to 8 and b is an integer from 1 to 7;
when d+e=10, d is an integer from 2 to 9 and b is an integer from 1 to 8;
when d+e=11, d is an in
Cook C. Brant
Ogden Necholus
Procter & Gamble Company
Taffy Frank
Zerby Kim W.
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