Esterquats preparation

Esterquats prepared from fatty acid methyldiethanolamine esters reacted with diethyl sulfate are useful as emulsifying and consistency-providing agents in cosmetic and/or pharmaceutical preparations [162]. 

Most often, the esterquats are prepared by reaction of a tertiary alkanolamine with a fatty acid, followed by reaction with an alkylating agent to the corresponding quaternary [6]. Other sources of the acyl chain include triglycerides, methyl esters, and acid chlorides. The reaction scheme for the preparation of the diester of bis-2-hydroxyethyldimethylammonium chloride from methyldiethanolamine and fatty acid is given in Fig. 3. 

Quaternization of the monoesteramines with a variety of alkylating agents proceeds well under mild conditions similar to the quaternization of the traditional dimethylalkylamines. In general, polar solvents like water, alcohols, and glycols are used to obtain liquid products at room temperature. Esterquats from other alkanolamines can be prepared by similar procedures. 

Esterquats with two different ester bonds, RC(0)0- and ROC(O)—, in the same molecule are reported by Nieuwenhuis (Fig. 7) [26], They are prepared by reacting dimethylethanolamine with fatty acid and subsequent quaterni-... 

A number of patent publications disclose alkanolamine-derived esterquats for use in cosmetic hair care and skin care preparations. Several trietha-... 

Esterquats with improved stability and biodegradability are prepared by quaternization of a fatty acid (partially hydrogenated tallow) alkanolamine ester with an alkylating agent (dimethyl sulfate) in the presence of nonionic emulsifiers [126] or cosmetic oils [159]. This procedure avoids problems associated with the use of lower alcohols as solvents in the reaction, such as low ignition point, poor emulsifying capacity for perfume oils, poor skin compatibility, and a defatting action on the skin. Formulations of a triethanolamine-based Coco esterquat, oil, and a Ci-Cg alcohol are useful in cosmetic and sunscreen formulations [160]. 

The use of cosmetic preparations containing esterquats (i.e., quaternized fatty acid triethanolamine ester salts) and sterols as skin care agents is claimed [161]. 

It has been shown recently in the patent appKcation Kterature that organo-clays based on specific types of esterquats can be effective for use in preparations of nanocomposites [184,185]. 

Another type of esterquats in the family of cleavable surfactants makes use of ortho-e ter linkages. It has been demonstrated recently in the literature that not only nonionic [193] but also cationic surfactants with ortho-e ter links can be prepared [194]. The ortho-e ter amine is prepared from a fatty alcohol, a short-chain ortho-e ter, and dimethylaminoethanol (Fig. 20). 

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