US 4,536,338 AGranted

Process for manufacture of fatty acid esters of hydroxy sulfonates

AssigneeLever Brothers Company

InventorsWarren J. Urban, Joseph Barillo, Jerry J. Krupa

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Abstract

A method is disclosed for preparing fatty acid isethionate soaps through direct esterification wherein the catalyst is quenched by an alkaline compound at the end of the esterification. Quenching inhibits transesterification between isethionate and later added stearic acids. Transesterification is undesirable impairing lather and bar soap firmness. The traditional stripping of lower molecular weight fatty acids is no longer necessary where low ratios of fatty acids to isethionates are utilized. Alternatively, stripping can be avoided with traditional molar ratios provided water co-distillate fatty acid is not recycled. Finally, it has been shown that zinc catalyzed reactions provide optimum yield and low corrosion at pH about 2.0 to 2.5.

Claims11

Dependent claims

A method is disclosed of preparing a compound of the formula RCOOR'SO.sub.3 M, wherein R is a C.sub.5 -C.sub.18 alkyl group, R' is selected from the group consisting of divalent C.sub.2 -C.sub.4 alkylene, C.sub.6 -C.sub.8 aryl and C.sub.7 -C.sub.8 alkylaryl radicals and M is an alkali metal cation, the process comprising:

(a) heating at 200.degree. to 260.degree. C. a first mixture of C.sub.5 -C.sub.16 monocarboxylic acid with a hydroxy sulfonate of the formula HOR'SO.sub.3 M, in a mole ratio of 1.01:1 to 2:1, in the presence of a catalyst;
(b) removing liberated water of esterification from the reaction mass and when the desired conversion to RCOOR'SO.sub.3 M is achieved;
(c) quenching the catalyst with an effective amount to neutralize the catalyst of an alkaline compound;
and
(d) adding a higher molecular weight C.sub.15 -C.sub.24 fatty acid to the reaction mixture subsequent or simultaneous with addition of alkaline catalyst quencher.

2 more elements

Dependencies are inferred from the claim text.