Organic compounds -- part of the class 532-570 series – Organic compounds – Fatty compounds having an acid moiety which contains the...
Reexamination Certificate
2002-01-08
2003-11-11
Raymond, Richard L. (Department: 1624)
Organic compounds -- part of the class 532-570 series
Organic compounds
Fatty compounds having an acid moiety which contains the...
C560S240000, C568S620000, C568S623000
Reexamination Certificate
active
06646145
ABSTRACT:
This invention relates to a process for the production of alkoxylated nonionic surtactants in which compounds containing active hydrogen atoms or carboxylic acid esters are reacted with alkylene oxides in the presence of optionally modified hydrotalcite as catalyst and optionally other selected co-catalysts and the reaction products obtained are aftertreated with acids.
An important group of nonionic surfactants are products of the addition of alkylene oxides, especially ethylene oxide and/or propylene oxide, onto compounds containing active hydrogen which are normally produced by homogeneous catalysis in the presence of alkali metal hydroxides or alkali metal alcoholates. Products with a broad homolog distribution are obtained by the homogeneously catalyzed process. Products with a narrow homolog distribution can be obtained by carrying out the reaction in the presence of optionally modified hydrotalcites, for example in accordance with DE-A-38 33 076. The alkoxylation of carboxylic acid esters also takes place with better results in the presence of hydrotalcites, the alkylene oxides being inserted into the carbonyl ester bond, for example in accordance with the two patents EP-B1-0 339 425 and EP-B1-0 523 089.
However, after the actual alkoxylation using optionally modified hydrotalcite, separation of the catalyst from the reaction product presents technical difficulties because the optionally modified hydrotalcite is generally so finely particulate that it can only be filtered through special filter candles. Unfortunately, the catalyst cannot be allowed to remain in the end reaction product either because otherwise clouding and sedimentation can occur.
Accordingly, the problem addressed by the present invention was to provide a process for the production of alkoxylated nonionic surfactants which would not have any of the disadvantages of the complex filtration or clouding and sedimentation of the end reaction product.
BRIEF SUMMARY OF THE INVENTION
Surprisingly, the problem stated above has been solved by decomposing the catalyst hydrotalcite and any co-catalysts present by addition of acids after the alkoxylation rather than removing them by filtration. The invention includes the observation that the acid aftertreatment decomposes the hydrotalcite and any co-catalysts present into products which can remain in the reaction mixture without any clouding or sedimentation subsequently occurring.
Accordingly, the present invention relates to a process for the production of alkoxylated nonionic surfactants by reaction of compounds containing active hydrogen atoms or carboxylic acid esters with alkylene oxides in the presence of optionally modified hydrotalcite as catalyst and optionally co-catalysts, characterized in that at least equimolar quantities—based on hydrotalcite and optionally co-catalysts—of acids are added after the alkoxylation.
DETAILED DESCRIPTION OF THE INVENTION
The compounds containing active hydrogen atoms may be selected, for example, from the following classes of compounds:
a1) alcohols containing 6 to 22 carbon atoms (so-called fatty alcohols) such as, for example, caproic alcohol, caprylic alcohol, capric alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, isostearyl, alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, linolyl alcohol, linolenyl alcohol, ricinolyl alcohol, elaeostearyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol and the technical mixtures thereof obtained, for example, in the hydrogenation of methyl ester fractions of native origin or aldehydes from Roelen's oxo synthesis. Fatty alcohols containing 12 to 18 carbon atoms, for example technical coconut or tallow fatty alcohol cuts, are preferred.
Another group of suitable fatty alcohols are the co-called Guerbet alcohols which are produced by the alkali-catalyzed condensation of 2 moles of fatty alcohol and which may contain 12 to 36 carbon atoms.
a2) Carboxylic acids containing 6 to 22 carbon atoms (so-called fatty acids) and hydroxyfatty acids such as, for example, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselic acid, linoleic acid, linolenic acid, ricinoleic acid, elaeostearic acid, arachic acid, gadoleic acid, behenic acid and erucic acid and the technical mixtures thereof obtained, for example, in the pressure hydrolysis of natural fats and oils. Fatty acids containing 12 to 18 carbon atoms, for example technical coconut oil or tallow fatty acids, are preferred.
a3) Alkyl phenols, polyglycols, fatty amines, vicinal hydroxy/alkoxy-substituted alkanes obtainable, for example, by ring opening of epoxide compounds with alcohols or carboxylic acids and secondary alcohols.
Within the group of compounds containing active hydrogen atoms, the alcohols or carboxylic acids containing 6 to 22 carbon atoms are preferred.
In another embodiment of the process according to the invention, carboxylic acid esters are used as starting materials. Basically, there are again two types of carboxylic acid esters, namely:
b1) carboxylic acid lower alkyl esters corresponding to formula (I):
R
1
CO—OR
2
(I)
in which R
1
CO is an aliphatic acyl group containing 6 to 22 carbon atoms and R
2
is a linear or branched alkyl group containing 1 to 4 carbon atoms. Typical examples are esters of caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselic acid, linoleic acid, linolenic acid, ricinoleic acid, elaeostearic acid, arachic acid, gadoleic acid, behenic acid and erucic acid and technical mixtures thereof with methanol, ethanol, propanol or butanol. Methyl esters of fatty acids containing 12 to 18 carbon atoms and, more particularly, technical coconut oil or tallow fatty acid methyl esters are preferably used.
b2) carboxylic acid glycerol esters corresponding to formula (II):
in which R
3
CO is an aliphatic acyl group containing 6 to 22 carbon atoms and R
4
and R
5
independently of one another represent hydrogen or likewise an aliphatic acyl group containing 6 to 22 carbon atoms.
Typical examples of such compounds are synthetic but preferably natural triglycerides, such as palm oil, palm kernel oil, coconut oil, rapeseed oil, olive oil, sunflower oil, cottonseed oil, peanut oil, linseed oil, lard oil, bovine tallow and lard. Castor oil or hydrogenated castor oil is preferably used.
In one preferred embodiment, the full esters are replaced by fatty acid partial glycerides, more particularly monoglycerides of fatty acids containing 12 to 18 carbon atoms. Technical coconut oil fatty acid monoglycerides are particularly preferred. Within the group of carboxylic acid esters, carboxylic acid lower alkyl esters, especially the methyl esters of carboxylic acids containing 6 to 22 carbon atoms, are preferred.
Optionally modified hydrotalcites are used as alkoxylation catalysts in the process according to the invention either on their own or in admixture with selected co-catalysts. In one embodiment of the present invention, optionally modified hydrotalcite is used on its own as catalyst. Calcined or hydrophobicized hydrotalcites, as known for example from German patent applications DE-A1 38 43 713 and DE-A1 40 10 606 (Henkel), are used as modified hydrotalcites. Calcined hydrotalcites are particularly preferred.
In another embodiment of the invention, optionally modified hydrotalcites and selected co-catalysts are used together as alkoxylation catalysts. Suitable co-catalysts are compounds from the group consisting of hydroxides, oxides and/or alkoxides of alkali metals and/or alkaline earth metals and of alkali metal and/or alkaline earth metal salts, tin salts and of mixed metal oxides.
Particularly suitable hydroxides of alkali metals and/or alkaline earth metals are lithium hydroxide and/or magnesium hydroxide.
Within the group of oxides of alkali metals and/or alkaline ear
Behler Ansgar
Folge Almud
Schares Horst-Dieter
Cognis Deutschland GmbH
Drach John E.
Ettelman Aaron E.
Raymond Richard L.
Tucker Zachary C.
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