SU654902A1 - Method of determining dispersion properties of engine oils - Google Patents

Description

The present invention relates to laboratory methods for determining the dispersing properties of motor oils and additives thereto.

Methods are known for determining the dispersing properties of oils by paper chromatography: in so doing, substances such as soot, bitumen, asphaltenes, or precipitates separated from waste oils 1, 2 are used as dispersing agents for additives, called oil polluters.

Thus, there is a known method for evaluating the dispersing properties of motor oils, which consists in the following: bitumen or sludge separated from waste oil in an amount of 1-5% is introduced into the test oil with intensive mechanical movement followed by sonication 2.

Then a drop of oil with a contaminant is applied to the chromatographic paper. Dispersing properties of motor oils are estimated by the size of the core and the diffusion zone of the oil spot obtained on chromatographic paper and their ratio. It is usually considered that the larger the size of the diffusion zone, the higher the dispersing properties of the oil.

Quantitative values of the dispersing properties of an oil can be found by using the following equation:

DC () - 100,

where DS is the dispersing ability of the oil at a given temperature, in%;

. 3. - outer diameter of the diffusion zone of the oil spot;

dn is the diameter of the oil spot core. In the study of the dispersing properties of motor oils by the above method, it was noted that contaminants such as sediments extracted from used oils, or oil asphaltenes replacing these sediments, or oxidized oil bitumen, are not effectively dispersed in the oil, as indicated by visible to the naked eye) particles of coagulation in the dre of the oil spot. The presence of undispersed contaminant particles in the oil to a certain extent influences the size and intensity of the color of the core and the diffusion zone of the oil spot, thereby looking for test results.

The purpose of the present invention is to increase the convergence of the results and the reliability of the determination of the dispersing properties of motor oils.

The goal is achieved by the fact that in a known method of assessing the dispersing properties of scavenging oils by introducing bitumen into the oil, asphaltenes or shrinkage from waste oil, followed by a drop of the resulting dispersion on the chromatographic paper and further determining the dimensions of the core and the diffusion zone of the resulting spot. the ratio of which is judged on the dispersing properties of oils, the contaminant is pre-dissolved in a hydrocarbon or halohydrocarbon solvent, which units in oil are removed. Benzene, toluene, xylene, amethylnaphthalene, carbon tetrachloride, etc. are used as solvents.

Example. A portion of the oil bitumen (grade BN-IV) in an amount of 1.5 g is dissolved in 30 ml of benzene at a temperature of 60-70 ° C. The resulting solution is poured into 30 g of the studied samples of oils A, B, B, G. The solvent is distilled off under vacuum at a temperature of 70-80 ° C, the oil is allowed to cool to room temperature, and then a drop of the studied oil is applied to the chromatographic paper to obtain a spot .

Next, the dimensions of the zones forming the spot are measured and the DS index is calculated. In tab. Table 1 shows the results of these determinations: the sizes of the zones of the forming spot and the values of the dispersing ability of the samples of oils A, B, C, G. In the table. Table 1 also shows the results of determining the dispersing properties of the same oil samples in a known manner (the contaminant is petroleum bitumen).

Comparison of the data obtained shows that the dimensions of the core and the diffusion zone when tested in a known manner and with the method according to the invention are different; The values of the DS index are also different.

Moreover, in the method according to the invention, the core color intensity is almost no different from the color of the diffusion zone, in the well-known core it is colored dark brown, many solid particles are visible on the bottom, the diffusion zone is colored light brown. To confirm the convergence of the results, assess the reliability of the method according to the invention and compare its objectivity with the known samples of motor oils tested on the ELV stands. The results of these tests are shown in Table. 1, it is shown that the method according to the invention provides better convergence of results and greater reliability, since it is characterized by better correlation with tests for ELVs.

Table 1

Thus, oils A and B, measured by detergent properties on the ELP stand of 2 points, are very different in dispersing ability determined by a known method, and when tested using the method according to the invention, indicators of dispersing properties that are similar in value are found (DS 83 and 88 respectively).

A similar picture is also observed when comparing the results of testing samples of oils C and D (see Table 1).

In the case of using carbon tetrachloride as a solvent, the method

According to the invention gives a much better convergence of results than the known (see Table 2).

When using sediment as a contaminant, isolated after testing the oil M-8G (TU 38-101-415-73) on the Petter AV1 stand and containing 20% asphaltenes, 27% tar and 9.5% asphaltogenic acids, the method using benzene gives better convergence than the known (without solvent), which is confirmed by testing at the ELV stand (see Table 2).

T a b. L II c and 2

Oil contaminant bit} m

Method according to the invention: carbon tetrachloride solvent

Oil B1538153I

Oil G17381251

The known method: Oil In Oil G

The contaminant sediment recovered after testing the oil. M-8G (TU-33-101-415-73) on the Petter A V I stand (in the sediment contains: asphaltene 20%, 27% tar,

asphaltogenic acids 9.5%)

Method according to the invention: solvent benzene

Oil A Oil B Oil G

The known method: Oil A Oil B Oil G

Soot contaminant

Oil A

15 Oil G

13

These comparative data show that the method according to the invention makes it possible to better differentiate oils by detergent-dispersing properties than is known. It should also be noted that the results obtained in a known manner using carbon black (Table 2) cannot be improved by using a solvent, since carbon black does not dissolve in any of the known solvents.

26 26.5

73 105

The use of the method according to the invention will reduce the cost of determining the detergent-dispersing properties of the engine oil compositions being developed by reducing the cost of: a costly motor test.

Claims (2)

Invention Formula The method of determining the dispersing properties of motor oils by dispersing in oil the contaminant - bitumen, asphaltenes or sediment from the oil of the south oil, followed by applying a drop of obtained dispersion on the chromatographic paper and determining the size of the core and the diffusion zone of the resulting spot, according to the ratio of which T about dispersing properties of oils, characterized in that, in order to increase the convergence of the results of validity of the determination, the contaminant is pre-dissolved in hydrocarbon 8 or halogen tlevodorodnom solvent which iosle administration in the oil was removed, information sources, the received note in the examination 1. F. Francois, A. Korveze. Laboratory and bench testing of engine oils, “Chemistry and fuel and oil technologies, 1971, No. 5, p. 39 2. Reports of the Pth International Symposium. “Investigation of the mechanism of action of additives. Halle, GDR, 1976, p. 13-14 (prototype).