Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Patent
1995-11-20
1998-05-26
Kight, John
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
536 41, 536 186, C07G 300, C07H 1500, C07H 1700
Patent
active
057566941
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for the production of light-colored alkyl and/or alkenyl oligoglycosides in which neutralization of the acidic catalysts is carried out in the presence of reducing agents.
2. Statement of Related Art
Alkyl oligoglycosides and, in particular, alkyl oligoglucosides are nonionic surfactants which are acquiring increasing significance by virtue of their excellent detergent properties and their high ecotoxicological compatibility. They are produced from sugars and starch degradation products which are normally acetalized in the presence of acidic catalysts. For reasons associated with the law of mass action, it is advisable to remove the water of condensation continuously from the reaction equilibrium and to use one component, usually the relatively inexpensive fatty alcohol, in an adequate excess. On completion of the reaction, the acidic catalyst is neutralized, for example with sodium hydroxide and/or magnesium oxide, and the excess fatty alcohol is distilled off to a residual content of <1% by weight.
The alkyl oligoglycosides obtained after distillation are heavily discolored and are unsuitable for marketing on aesthetic grounds. Accordingly, to produce light-colored products, the alkyl oligoglycosides have to be bleached after distillation. It is obvious in this connection that there is a considerable demand for processes which, even if they do not prevent it, at least limit the discoloration of the crude reaction products during their production. Accordingly, the problem is to produce lighter-colored products for the same quantity of bleaching agents or to obtain products of satisfactory color with, comparatively, a smaller quantity of bleaching agents.
Another problem affecting the production of alkyl oligoglycosides is the quality of the fatty alcohol which is recovered during the distillation step and returned to the process. In continuous operation, the distillate alcohol undergoes uncreasing discoloration accompanied by the accumulation of carbonyl compounds which necessitate separate working up. Here, too, it is desirable to carry out the process for the production of alkyl oligoglycosides in such a way that any deteriorations in quality can at least be limited if not completely avoided.
DESCRIPTION OF THE INVENTION
The present invention relates to a process for the production of alkyl and/or alkenyl oligoglycosides corresponding to formula (I) carbon atoms, G is a sugar unit containing 5 or 6 carbon atoms and p is a number of 1 to 10, by acid-catalyzed acetalization of sugars with primary alcohols, in which the reaction mixture is neutralized in the presence of reducing agents and then bleached in known manner.
It has surprisingly been found that the addition of reducing agents in the neutralization of the crude acetalization products after bleaching leads to products significantly improved in color. At the same time, the color and carbonyl value of the fatty alcohols recovered after distillation are improved to such an extent that there is no longer any need for separate working up, even after a large number of cycles.
Alkyl and/or alkenyl oligoglycosides
Alkyl and alkenyl oligoglycosides are known compounds which may be obtained by the relevant methods of preparative organic chemistry. EP-A1-0 301 298 and WO 90/3977 are cited as representative of the extensive literature available on the subject.
The alkyl and/or alkenyl oligoglycosides may be derived from aldoses or ketoses containing 5 or 6 carbon atoms, preferably from glucose. Accordingly, the preferred alkyl and/or alkenyl oligoglycosides are alkyl and/or alkenyl oligoglucosides.
The index p in general formula (I) indicates the degree of oligomerization (DP degree), i.e. the distribution of mono- and oligoglycosides, and is a number of 1 to 10. Whereas p in a given compound must always be an integer and, above all, may assume a value of 1 to 6, the value p for a certain alkyl oligoglycoside is an analytically determined calculated quantity which
REFERENCES:
patent: 3452064 (1969-06-01), Stein et al.
patent: 4465828 (1984-08-01), Rau et al.
patent: 4483979 (1984-11-01), Mao
patent: 4557729 (1985-12-01), McDaniel, Jr. et al.
patent: 4762918 (1988-08-01), McDaniel, Jr. et al.
patent: 4898934 (1990-02-01), Lueders et al.
patent: 4904774 (1990-02-01), McDaniel, Jr. et al.
patent: 4990605 (1991-02-01), Lueders
patent: 5003057 (1991-03-01), McCurry et al.
patent: 5079350 (1992-01-01), Fujita et al.
patent: 5104981 (1992-04-01), Yamamuro et al.
patent: 5374716 (1994-12-01), Biermann et al.
patent: 5538669 (1996-07-01), Schulz et al.
patent: 5554742 (1996-09-01), Wolf et al.
patent: 5576425 (1996-11-01), Hill et al.
patent: 5612467 (1997-03-01), Weuthen et al.
Drach John E.
Henkel Kommanditgesellschaft auf Aktien
Jaeschke Wayne C.
Jones Dameron
Kight John
LandOfFree
Process for the production of light-colored alkyl and/or alkenyl 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 light-colored alkyl and/or alkenyl, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the production of light-colored alkyl and/or alkenyl will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1961846