Occidental Chemical Corporation

Other

Jian S Qi

Garra C Lester

David E Albright, Jr

Chandrasekhar Krishnan

Vivek Jain

Joseph A Incavo

William L Reuter

Disclosed is a method of determining whether a solvent contains a tautomeric cyclic 1,2-dione. It is first determined whether the pH of the solvent is acidic (&lt;5), basic (&gt;9), or neutral (5 to 9). If the pH is neutral, an acid or a base is added to make the pH acidic or basic, respectively. The UV absorbance at a first wavelength between about 230 nm and about 270 nm and at a second wavelength between about 280 and about 320 nm is determined. If the pH is acid, it is changed to basic and, if it is basic, it is changed to acidic. The UV absorbance at the first and second wavelengths is again determined. The presence of a tautomeric cyclic 1,2-dione is indicated if the absorbance at the first wavelength was greater when the solvent was acidic and the absorbance at the second wavelength was greater when the solvent was basic. The concentration of the tautomeric cyclic 1,2-dione can be determined by multiplying the change in absorbance by a constant.

Method of detecting tautomeric cyclic 1,2-diones

Disclosed is a method of making a glycol ether acetate. Acetic acid is reacted with a glycol ether at a molar ratio of about 1.1 to about 2, in a mixture with a catalyst and an azeotropic agent which can be either butyl acetate or dibutyl ether. The mixture is heated to a temperature and pressure sufficient to vaporize an azeotrope of water and the azeotropic agent. In another embodiment of the invention, a glycol ether acetate is made by preparing a reaction mixture of acetic acid and a glycol ether in a molar ratio of about 1.1 to about 1.2, about 5 to about 25 wt % n-butanol, an additional amount of acetic acid stoichiometric with the amount of n-butanol, and a catalyst. The reaction mixture is heated to form a glycol ether acetate, water, and butyl acetate. The azeotrope, excess acetic acid, butyl acetate, and glycol ether are successively removed by distillation.

Process for making glycol ether acetates

Disclosed is a method of determining a diffusion coefficient for a diffusant in a particulate. An inert gas is passed through a particulate containing the diffusant. A parameter that is proportional to the concentration of the diffusant in the inert gas is measured over a period of time and the slope of the linear portion of that relationship is determined and is multiplied by a constant.

Determination of diffusion coefficient

Disclosed is a method of making a liquid ether acetate. After reacting acetic acid with the corresponding ether alcohol, the resulting mixture of ether acetate, water, acetic acid, and ether alcohol is, with no distillation, contacted with alumina. Particular ether acetates that can be treated include ethylene glycol monobutyl ether acetate and diethylene glycol monobutyl ether acetate. The treated acetates are more stable to hydrolysis after they have been passed over a bed of alumina.

Acetic acid removal from liquid ether acetates

Disclosed is a process for isolating and purifying 2,4,5-trifluorobenzoic acid from a solution in a decarboxylating solvent such as NMP. The solution is neutralized with a hydroxide. This results in the formation of a salt of the 2,4,5-trifluorobenzoic acid, which precipitates. The slurry is filtered to collect the precipitated salt and the precipitated salt is dissolved in water. The aqueous solution of the salt is then acidified which results in the reformation and precipitation of the 2,4,5-trifluorobenzoic acid.

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Amherst, NY, United States of America

Jian S Qi