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AssigneeKao Corporation
InventorsTakeshi Shirasawa, Yasuo Amishige, Kaoru Omae, Akira Matsunaga, Akira Sakaguchi
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The present invention provides a method for producing polyoxyalkylene alkyl ether carboxylic acid and a salt thereof, including supplying polyoxyalkylene alkyl ether, oxygen, and water to a continuous stirred tank reactor containing a noble metal catalyst to oxidize the polyoxyalkylene alkyl ether with oxygen, in which the molar ratio of the salt of polyoxyalkylene alkyl ether carboxylic acid to the polyoxyalkylene alkyl ether in the continuous stirred tank reactor is controlled to 0.33 to 49.
A method for producing a polyoxyalkylene alkyl ether carboxylic acid and a salt thereof, comprising continuously supplying polyoxyalkylene alkyl ether, oxygen, and water to a continuous stirred tank reactor in the presence of a noble metal catalyst in a reaction system that conducts both continuous supply of the materials into the stirred tank and continuous extraction of a product from the stirred tank to control the reaction in order to have the molar ratio of the salt of polyoxyalkylene alkyl ether carboxylic acid to the polyoxyalkylene alkyl ether in the reactor within the range of 0.33 to 49.
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Arsenic, antimony or bismuth: bismuth
Of oxygen-containing groups to carboxyl groups: of —CHO groups or primary alcohol groups
Chemical or physical processes
Acyclic or carbocyclic compounds
About 5 years of term left · ends 14 Oct 2031 (estimated)
The present invention relates to a method for producing polyoxyalkylene alkyl ether carboxylic acid and a salt thereof.
Salts of polyoxyalkylene alkyl ether carboxylic acid are compounds produced by substituting polyoxyalkylene alkyl ether with carboxylic acid at the terminal end of the ether, and are known as a useful surfactant used in cosmetics, emulsifiers, solubilizers, dispersants, gelling agents, and detergent bases, and the like. The salts can be modified in properties by changing pH. These salts have good stability against hard water. Aqueous solutions thereof are stable to various polyvalent metal ions such as an aluminum ion, gentle to the skin, and have small inhibitory effects on enzymes. The salts are thus expected to have various applications.
There have been various known methods for producing a salt of polyoxyalkylene alkyl ether carboxylic acid. One of the methods in which polyoxyalkylene alkyl ether is oxidized with oxygen in the presence of a noble metal catalyst is known (JP-A 56-169644, JP-A 62-198641, and JP-A 62-269746). JP-A 01-146840 describes addition of an ether carboxylic acid to a polyalkoxy alcohol or a fatty alcohol alkoxylate in oxidation of the polyalkoxy alcohol or the fatty alcohol alkoxylate to produce the ether carboxylic acid.
Oxidation of polyoxyalkylene alkyl ether with oxygen in the presence of a noble metal catalyst generally takes a relatively long time to achieve a certain reaction rate (e.g., about 60%). JP-A 01-146840 describes a method capable of reducing the reaction time, but does not fully refer to specific conditions and the like for efficient production of polyoxyalkylene alkyl ether carboxylic acid having high quality in color and the like for a short time. In particular, there is no special suggestion about efficient means for production of polyoxyalkylene alkyl ether carboxylic acid having a good color, using an industrially practical apparatus for continuous production of ether carboxylic acid, such as a continuous stirred tank reactor.
The present invention provides a method for efficiently producing polyoxyalkylene alkyl ether carboxylic acid and a salt thereof having high quality using a continuous stirred tank reactor.
The present invention provides a method that can efficiently produce polyoxyalkylene alkyl ether carboxylic acid and a salt thereof having a high quality in color and the like, using a continuous stirred tank reactor.