Solid anti-friction devices – materials therefor – lubricant or se – Lubricants or separants for moving solid surfaces and... – Azo compound
Reexamination Certificate
2000-06-07
2003-02-04
Howard, Jacqueline V. (Department: 1764)
Solid anti-friction devices, materials therefor, lubricant or se
Lubricants or separants for moving solid surfaces and...
Azo compound
C508S390000, C508S421000, C508S546000, C508S557000, C008S521000, C008S662000, C044S328000, C534S558000, C534S856000
Reexamination Certificate
active
06514917
ABSTRACT:
BACKGROUND OF THE INVENTION
In the present invention, novel chromogenic chemical substances are disclosed as molecular tags for organic solvent solutions, especially petroleum products. A method of synthesizing, detecting and quantifying these new substances is also disclosed. The detection methods provides a novel and improved technique for detecting and quantifying some known marker substances. With the present invention, color or fluorescence is developed in a single phase system containing the petroleum product, without need of a separate extraction step.
Proton accepting chemical substances, that at a solution concentration of below about 20 milligrams per litre, impart little or no significant color to organic solvents, have been proposed as markers, or taggants, especially for petroleum-derived fuels, on many occasions. The marker is dissolved in a liquid to be identified, then subsequently detected by performing a simple physical or chemical test on the marked liquid. Markers are sometimes employed by government agencies to ensure that the appropriate tax has been paid on particular grades of fuel. Oil companies also mark their products to help assist in identifying those who have diluted or altered their products. These companies often go to great expense to make sure their branded petroleum products meet certain specifications, for example, volatility and octane number, as well as to provide their petroleum products with effective additive packages containing detergents and other components. Consumers rely upon the product names and quality designations to assure that the product being purchased is the quality desired.
Traditionally, the presence of these substances is detected and optionally quantified by extracting the fuel with an immiscible aqueous or significantly aqueous solution of an acid substance, the precise nature of which can be varied according to the characteristics of the marker substance. The acid reacts with the basic compound to produce a readily visible, more or less intensely colored cation, that is dissolved in the aqueous acid phase. This technique is illustrated in the disclosure of U.S. Pat. No. 5,145,573.
The quantity of marker substance in the extract may also be measured, for instance, by visible light absorption spectrophotometry, the results of which are then compared with a reference standard to determine the original concentration of basic marker in the fuel. It is sometimes necessary to make repeated, typically two or three, extractions of the fuel to recover all the marker originally present in order for complete quantification. Consequently, it is also relatively simple to remove the marker from the marked fuel by this reaction. This is a shortcoming of these prior art basic marker substances; they are relatively easy to remove from fuels by unscrupulous parties who may wish to defraud tax authorities, or individual consumers. For instance, marked low octane gasoline may be laundered to remove the marker enabling fuel to be resold as unmarked, higher price premium fuel. Alternatively, marked #2 fuel oil, sold tax free as home heating oil or railroad or agricultural diesel fuel, may have the marker removed from it in order to resell it at the much higher price of taxed, on road, diesel engine fuel. The lawful tax collection agencies are thereby deprived of their revenues. In the United States, such revenues have increased by about 2 billion dollars since implementing a marker program in 1993.
Additionally, the extracted, separated phase is classifiable as a hazardous waste and presents problems of safe and lawful disposal, especially when examinations are made “in the field.” Furthermore, the fuel with which it was in contact may be water wet, making return to its original source undesirable and thus presenting an additional waste disposal problem. By using a developing agent of the present invention, especially hydrocarbon or alcoholic solutions of an organic phosphoric or sulfonic acid, the indicative color or fluorescence of the marker can be made plainly and instantly visible and can be quantified without extraction from the petroleum product.
The rapidity and certainty of the test procedure is very important in field testing to minimize delaying trucks and wrongful impoundment of vehicles. Isotopic labeling can also be useful as a secondary analytical procedure to confirm, independently, results already obtained by chromogenic analysis.
SUMMARY OF INVENTION
The present invention provides compositions comprising a petroleum product, which forms an organic phase, a marker substance dissolved in the petroleum product, and a non-aqueous acid combined with the marker substance in the organic phase to develop a detectable color. It also includes compositions comprising a petroleum product, which forms an organic phase, a marker substance dissolved in the petroleum product, and an acid combined with the marker substance and petroleum product to develop a detectable color or fluorescence in the organic phase.
Markers for petroleum products are also provided. They have the following structure:
where A, B, and C, independently of each other, are aromatic carbocyclic moeities, N is nitrogen and R is an alkyl group or hydrogen atom. Further, the present invention provides methods of identifying a petroleum product containing an acid reactable marker by first obtaining a sample of petroleum product containing an acid reactable marker, and then adding to that sample a developing agent comprising a non-aqueous acid or solution to form a single phase in which the acid and marker combine to develop a detectable color.
DESCRIPTION OF THE INVENTION
The present invention provides novel molecular taggants or markers and developing agents for use with them. The developing agents may also be used with preexisting markers that react with an acid. The markers are essentially invisible in liquid petroleum products at an effective level of use but provide a distinctive color and/or fluorescence when contacted by an appropriate developing agent of the present invention. The procedure of the present invention for developing color or fluorescence is simple to perform in the field and the reagents used to develop the color are easy to handle and recycle.
With the present invention, the procedure for detecting and quantifying acid reactive markers, for petroleum-derived compositions, can take place directly in the petroleum product without extraction of an aqueous phase. This reaction is accomplished preferably with a non-aqueous organic acid solution that is miscible with that petroleum product. This combination produces an instant visual or, if desired, instrumental indication of the presence of the marker substance. The marker concentration may be determined accurately by, for instance, standard spectrophotometric procedures. The procedure of the present invention is faster and more convenient than use of aqueous acid extractions to produce a quantitative result and an extended time period to yield complete phase separations. The new procedure also reduces potential environmental disposal problems since the developed, marked product may be returned to its origin; optionally, with neutralization of the acid developer, with, for instance, an aliphatic amine that is miscible with the said petroleum product. It also permits the use of acid reactable marker substances that do not readily extract from the petroleum product under aqueous acid conditions.
Developing reagents of the present invention are symbolized generally by R—OH where the OH group is part of an acid moeity with a pK
a
value of 3.5 or less and R is a mono alkyl or aryl sulfonic acid moeity or a mono alkyl or dialkyl phosphoric acid.
The preferred acids for marker development are those which are fully miscible with the petroleum product. In addition, for quantitative analysis the salt they develop, by reaction with the marker substance, should also be completely soluble in the fuel.
The final choice of acid can vary from one system to another according to solubility parameters. For instance
Desai Bharat
Frederico Justin J.
Smith Michael J.
Collier Shannon Scott PLLC
Coulby John N.
Howard Jacqueline V.
Larmann Jamie M.
United Color Manufacturing Inc.
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