Organic compounds -- part of the class 532-570 series – Organic compounds – Fatty compounds having an acid moiety which contains the...
Patent
1992-11-24
1995-01-17
Dees, Jose G.
Organic compounds -- part of the class 532-570 series
Organic compounds
Fatty compounds having an acid moiety which contains the...
554 85, 554 96, 554 97, C07C30332
Patent
active
053826779
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for the production of free-flowing pastes of .alpha.-sulfofatty acid alkyl ester alkali metal salts containing 60 to 70% by weight washing-active substance, in which acidic .alpha.-sulfofatty acid alkyl esters are neutralized with aqueous alkali metal hydroxide solutions under defined pH conditions. In the context of the present invention, washing-active substance (WAS) is understood to be the sum total of .alpha.-sulfofatty acid alkyl ester alkali metal salt and the .alpha.-sulfofatty acid dialkali metal salt--always present as a secondary product--in the neutralized .alpha.-sulfofatty acid ester.
2. Statement of Related Art
.alpha.-Sulfofatty acid alkyl ester alkali metal salts are acquiring increasing significance as surfactants for detergents and cleaning preparations based on renewable natural raw materials. In known processes, the .alpha.-sulfofatty acid alkyl ester alkali metal salts are obtained in the form of aqueous solutions or pastes by neutralization of .alpha.-sulfofatty acid alkyl esters which may be synthesized reaction of lower fatty acid alkyl esters with gaseous SO.sub.3. In the final analysis, the basis for the production of the .alpha.-sulfofatty acid alkyl ester alkali metal salts are fats and oils of natural origin from which the lower fatty acid alkyl esters are obtained by lipolysis and subsequent esterification of the free fatty acids with lower alkanols or by transesterification of the natural triglycerides with lower alkanols. In both reactions, methanol is preferably used as the lower alkanol. The lower fatty acid alkyl esters are mixtures in which C.sub.6-22 fatty acid residues occur, the chain length distribution being dependent on the origin of the natural fats or oils. In many cases, these fatty acid mixtures are not used for the synthesis as such, but rather in the form of certain fractions. Sulfonation of the fatty acid ester mixtures with gaseous SO.sub.3 gives acidic .alpha.-sulfofatty acid alkyl esters which are converted into aqueous pastes of .alpha.-sulfofatty acid alkyl ester alkali metal salts by neutralization to a pH value of 6 to 8. The crude .alpha.-sulfofatty acid alkyl esters and their alkali metal salts are more or less colored products which generally have to be treated with typical bleaches, such as hydrogen peroxide or alkali metal hypochlorite, before and/or after neutralization.
One particular difficulty involved in the production and handling of aqueous .alpha.-sulfofatty acid alkyl ester alkali metal salt pastes arises out of their viscosity behavior in dependence upon the solids concentration. In aqueous compositions, the .alpha.-sulfofatty acid alkyl ester alkali metal salts produced by conventional industrial processes (hereinafter also referred to in short as ester sulfonates) only form solutions or suspensions of such low viscosity that they flow sufficiently freely to guarantee uninterrupted completion of industrial processes at WAS contents of up to about 40% and then again beyond WAS contents of around 55%. In the intermediate concentration range, i.e. at WAS contents of around 40 to 55% by weight, the aqueous ester sulfonate compositions show extremely high viscosity values, assuming the form of more or less solid gels which can neither be stirred nor pumped. In addition, the lower and upper limits of the individual viscosity maxima can vary by .+-.5% by weigh solids content. As a result of this particular concentration/viscosity behavior, ester sulfonate pastes having WAS contents above 35 to 40% by weight cannot be obtained simply by neutralization of the acidic .alpha.-sulfofatty acid alkyl esters with the calculated quantity of aqueous alkali metal hydroxide solutions. After the lower limit to the viscosity maximum has been exceeded, the reacting mixture loses its stirrability and miscibility. The lack of stirrability and miscibility prevents adequate and rapid dissipation of the heat of neutralization. Local concentration and temperature peaks ini
REFERENCES:
patent: 3251868 (1966-05-01), Stein et al.
patent: 4102911 (1978-07-01), Majimu et al.
patent: 4668438 (1987-05-01), Pierr et al.
Colignon Dietmar
Dorra Erich
Panthel Guenter
Schmidt Wolfgang
Wrede Norbert
Carr D. D.
Dees Jos,e G.
Drach John E.
Henkel Kommanditgesellschaft auf Aktien
Jaeschke Wayne C.
LandOfFree
Process for the production of highly concentrated pastes of .alp does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the production of highly concentrated pastes of .alp, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the production of highly concentrated pastes of .alp will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-747768