摘要 |
<p>The object of the invention is the use of phosphonic acids of the formula (4), where R2 is H or C1-C500-alkyl, and R3 and R4 independently from each other are H or C1-C500-alkyl, with the proviso that not all groups R2, R3, R4 are hydrogen, and having a molecular weight from 250 to 10,000 units, in quantities from 0.5 to 10,000 ppm with respect to the oil, for the dispersion of asphaltenes in asphalt-containing crude oils or residual oils.</p> |