Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Liquid composition
Reexamination Certificate
2000-06-29
2001-11-06
Ogden, Necholus (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Liquid composition
C510S424000, C510S426000, C510S428000
Reexamination Certificate
active
06313085
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention is in the field of cosmetics and relates to novel anionic surfactant concentrates having defined amounts of alkyl ether sulfates and alkyl sulfates, to a method for the preparation thereof, and to the use thereof in cosmetics.
Alkyl ether sulfates are notable for excellent foaming properties. As well as a high base foam, advantageous foam kinetics are also found, i.e. even in the presence of fats and water hardness a creamy foam is obtained which persists for a long period and does not collapse. Since alkyl ether sulfates are also extremely well tolerated by the skin and have good cleansing properties, they are often used for the preparation of hair and skin cleansing compositions, such as, for example, hair shampoos, shower preparations and the like. A disadvantage, however, is that alkyl ether sulfates do not favor the incorporation of some oily substances, in particular of silicone oils. The formulations are often cloudy and undergo separation, particularly under thermal stress, meaning that further, generally nonionic, emulsifiers have to be co-used. In addition to these application problems, alkyl ether sulfates have the disadvantage that, in high-concentration form, they are virtually cut-resistant pastes which become pumpable only as a result of dilution or warming, which hinders handling.
Accordingly, the object of the present invention was; firstly to provide additives for alkyl ether sulfates so that the miktures are flowable, pumpable and sprayable even in high-concentration form, without the need for the co-use of polyols and consequently without adversely affecting the application properties. Quite the opposite, these novel mixtures should allow the stable incorporation of silicone oils into shampoo formulations.
DESCRIPTION OF THE INVENTION
The invention provides high-concentration flowable aqueous anionic surfactant mixtures having a solids content in the range from 50 to 80% by weight, comprising—based on the surfactant content
(a) 60 to 90% by weight of alkyl ether sulfates of the formula (I),
R
1
O(CH
2
CH
2
O)
n
SO
3
X
1
(I)
in which R
1
is a linear or branched alkyl radical having 12 to 22 carbon atoms, n is a number from 1 to 10, and X
1
is alkali metal, alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium, and
(b) 10 to 40% of weight of alkyl sulfates of the formula (II),
R
2
OSO
3
X
2
(II)
in which R
2
is a linear or branched alkyl radical having 12 to 22 carbon atoms, and X
2
is alkali metal, alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium,
with the proviso, that the amounts, optionally with further surfactants, total 100% by weight.
Surprisingly, we have found that the anionic surfactant mixtures according to the invention, despite the high solids content and also without the co-use of polyols, display a viscosity minimum within the given composition as a result of mixed micelle formation, making the compositions flowable, pumpable and, in particular, also sprayable at ambient temperature. The invention encompasses the knowledge that the preparations in particular also permit the stable and nonturbid incorporation of silicone oils which are otherwise difficult to formulate into shampoos, without the foaming and cleansing ability, and the skin cosmetic compatibility being adversely affected.
Anionic Surfactant Mixtures
In a preferred embodiment, the anionic surfactant mixtures have a solids content in the range from 65 to 75% by weight and in particular 70 to 72% by weight, preferably comprising—in each case based on the surfactant content −75 to 85% by weight of alkyl ether sulfates and 15 to 25% by weight of alkyl sulfates. Typical examples of suitable alkyl ether sulfates are sulfates based on the addition products of, on average, 1 to 10 mol of ethylene oxide to lauryl alcohol, isotridecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, arachidyl alcohol and behenyl alcohol, and the technical-grade mixtures thereof, such as, for example, cocoa alcohol, palm alcohol, palm kernel alcohol or tallow alcohol in the form of their sodium, magnesium and/or alkanolamine salts. The mixtures preferably comprise alkyl ether sulfates of the formula (I), in which R
1
is an alkyl radical having 12 to 18 carbon atoms and n is a number from 2 to 5. Typical examples of suitable alkyl sulfates are the sulfates of the abovementioned alcohols, likewise again in the form of their sodium, magnesium and/or alkanolamine salts. The mixtures here preferably comprise alkyl sulfates of the formula (II) in which R
2
is an alkyl radical having 16 to 18 carbon atoms (cetearyl alcohol sulfate). For the person skilled in the art, the term “high-concentration flowable” means a Brookfield viscosity, measured in an RVT viscometer at a temperature of 20° C., a shear rate of 10 rpm and with a spindle of type 1, of less than 50,000 mPas, preferably less than 30,000 and in particular less than 10,000 mPas.
Preparation Method
In principle, the surfactant mixtures according to the invention can be prepared by mixing the individual substances. However, it preferably takes place by cosulfation of the alcohols. The invention therefore further provides a method for the preparation of anionic surfactant mixtures, in which method mixtures of
(a) 60 to 90% by weight of alcohol polyglycol ethers of the formula (III),
R
3
O (CH
2
CH
2
O)
n
H (III)
in which R
3
is a linear or branched alkyl radical having 12 to 22 carbon atoms, and n is a number from 1 to 10, and
(b) 10 to 40% by weight of alcohols of the formula (IV),
R
4
OH (IV)
in which R
4
is a linear or branched alkyl radical having 12 to 22 carbon atoms, are jointly sulfated and neutralized, and in the course of the process the solids content is adjusted to a value in the range from 50 to 80% by weight. The formulae (III) and (IV) correspond here to the formulae (I) and (II), making it unnecessary to again discuss the examples of suitable feed material. The reaction of the starting materials with gaseous sulfur trioxide can be carried out in the manner known for fatty acid lower alkyl esters [J. Falbe (ed.), “Surfactants in consumer products”; Springer Verlag, Berlin-Heidelberg, 1987, p. 61], reactors which operate according to the falling-film principle being preferred. In the process, the sulfur trioxide is diluted with an inert gas, preferably air or nitrogen, and used in the form of a gas mixture which comprises the sulfonating agent in a concentration of from 1 to 8% by volume, in particular 2 to 5% by volume. The molar feed ratio of starting mixture to sulfur trioxide is 1:0.95 to 1:1.8, but preferably 1:1.0 to 1:1.6 and in particular 1:1.3 to 1:1.5. As well as using gaseous sulfur trioxide, another suitable sulfonating agent is chlorosulfonic acid. The joint sulfation is carried out at temperatures of from 15 to 50° C., preferably 25 to 40° C. The sulfuric monoesters which form during the reaction are stirred into aqueous bases, neutralized and adjusted to a pH of from 7.5 to 8.5. Neutralization is carried out using bases chosen from the group formed from alkali metal hydroxides, such as sodium, potassium and lithium hydroxide, alkaline earth metal oxides and hydroxides, such as magnesium oxide, magnesium hydroxide, calcium oxide and calcium hydroxide, ammonia, mono-, di- and tri-C
2-4
-alkanolamines, for example mono-, di- and triethanolamine, and primary, secondary or tertiary C
1-4
-alkylamines. The neutralization bases are preferably used here in the form of 35 to 55% strength by weight aqueous solution. The sulfates obtainable by the method according to the invention are, following neutralization, in the form of aqueous solutions having an active substance content of from 50 to 80% by weight, preferably 65 to 75% by weight. The sulfation products can, following neutralization, be bleached in a manner known per se by adding hydrogen peroxide or sodium hypochlorite solution in order to achieve further color lightening desired for. many ap
Cognis Deutschland GmbH
Drach John E.
Ogden Necholus
Trzaska Steven J.
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