Lubricant composition

Abstract

A lubricant composition containing a base oil, an alkyl benzene sulfonate metal salt, and an alkyl naphthalene sulfonate metal salt, wherein a total content of the alkyl benzene sulfonate metal salt and the alkyl naphthalene sulfonate metal salt is 1 to 2.2% by mass, and a mass fraction of the alkyl benzene sulfonate metal salt to a total mass of the alkyl benzene sulfonate metal salt and the alkyl naphthalene sulfonate metal salt is 0.3 or more.

Claims

1. A lubricant composition comprising: a base oil; a thickener; a neutral C.sub.9-C.sub.36 alkyl benzene sulfonate metal salt which has 1 or 2 alkyl groups; and a neutral C.sub.9 alkyl naphthalene sulfonate metal salt which has 2 alkyl groups, wherein a content of the alkyl benzene sulfonate metal salt in the lubricant composition is 0.8 to 1.7% by mass, a content of the alkyl naphthalene sulfonate metal salt in the lubricant composition is 0.1 to 1.2% by mass, a total content of the alkyl benzene sulfonate metal salt and the alkyl naphthalene sulfonate metal salt in the lubricant composition is 1 to 2.2% by mass, and a mass fraction of the alkyl benzene sulfonate metal salt to a total mass of the alkyl benzene sulfonate metal salt and the alkyl naphthalene sulfonate metal salt is 0.4 to 0.92.

2. The lubricant composition according to claim 1, wherein the alkyl benzene sulfonate metal salt is an alkyl benzene sulfonate calcium salt, and the alkyl naphthalene sulfonate metal salt is an alkyl naphthalene sulfonate barium salt.

3. The lubricant composition according to claim 1, wherein the alkyl benzene sulfonate metal salt has 2 alkyl groups.

4. The lubricant composition according to claim 1, which is an aluminum rust-preventive agent.

Description

EXAMPLES

(1) Hereinafter, preferable embodiments of the present disclosure will be specifically described with reference to Examples and Comparative Examples; however, the present disclosure is not limited to these Examples.

Examples 1 to 7 and Comparative Examples 1 to 13

(2) The lubricant compositions were prepared by blending each material with a compounding ratio shown in the following Tables 1 and 2. Next, 2 aluminum alloy plates were prepared. The aluminum alloy plates used had the following material and dimensions.

(3) Material: ADC12, 2.37% by mass of Cu, 10.55% by mass of Si, 0.01% by mass of Zn, 0.12% by mass of Fe, 0.01% by mass of Ni, and 86.94% by mass of Al.

(4) Dimensions: 20 mm20 mm in length and 5 mm in thickness.

(5) Surface Roughness Ra: 0.5 m.

(6) Between the 2 plates of the above aluminum alloy plates, 0.5 ml of the lubricant composition prepared in each example was applied to make a test piece, and the test piece was fixed by test piece jigs. The test piece jigs were arranged to catch the test piece between a pair of the jigs opposed each other, and fixed by tightening screws at four corners of the pair of the jigs at 2 Nm of tightening torque. After this, the test piece was subjected to a salt water immersion test. Specifically, in the salt water immersion test, the test jigs to which the test piece was fixed was immersed in the salt water having a concentration of 3% by mass at 80 C. filled in an isothermal tank, to leave to stand for 100 hours. Next, the test piece was taken out of the salt water, to be dried under room temperature for 24 hours. With respect to the aluminum alloy plates after drying, a growth distance of rust from an end face was visually observed. Then, it was evaluated as follows: one in which the rust was not observed on surfaces of the aluminum alloy plates and the growth distance of the rust was 0 mm was Good as excellent in rust-prevention; one in which the growth distances of the rust from the end faces of surfaces of the aluminum alloy plates was more than 0 mm and less than 1 mm was Fair as within acceptable in rust-prevention; and one in which the growth distances of the rust from the end faces of surfaces of the aluminum alloy plates was 1 mm or more was Poor as inferior in rust-prevention. The evaluation results are shown in Tables 1 and 2.

(7) TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Base Oil 90.4 90.4 90.4 90.4 90.4 90.4 90.4 (parts by mass) Thickener 9.6 9.6 9.6 9.6 9.6 9.6 9.6 (parts by mass) Alkyl naphthalene 0.3 1.0 0.3 0.3 1.2 0.1 sulfonate metal salt 1 (parts by mass) Alkyl naphthalene 0.3 sulfonate metal salt 2 (parts by mass) Alkyl benzene 1.1 1.7 sulfonate metal salt 1 (parts by mass) Alkyl benzene 1.7 1.7 1.0 0.8 1.1 sulfonate metal salt 2 (parts by mass) Total content 2.0 2.0 2.0 1.4 2.0 2.0 1.2 (% by mass) Content Ratio 0.85 0.85 0.50 0.79 0.85 0.40 0.92 () Growth Distance 0 0 0 0.68 0.81 0.58 0.35 of Rust (mm) Evaluation Good Good Good Fair Fair Fair Fair

(8) TABLE-US-00002 TABLE 2 Comparative Comparative Comparative Comparative Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Base Oil 90.4 90.4 90.4 90.4 90.4 90.4 90.4 (parts by mass) Thickener 9.6 9.6 9.6 9.6 9.6 9.6 9.6 (parts by mass) Alkyl naphthalene 0.3 0.1 1.7 1.9 sulfonate metal salt 1 (parts by mass) Alkyl naphthalene sulfonate metal salt 2 (parts by mass) Alkyl benzene 0.2 sulfonate metal salt 1 (parts by mass) Alkyl benzene 2.1 0.7 0.3 1.7 1.7 sulfonate metal salt 2 (parts by mass) Extreme-Pressure Agent (parts by mass) Total content 2.4 0.8 2.0 0.0 1.7 1.9 1.9 (% by mass) Content Ratio 0.88 0.88 0.15 0.00 1.00 1.00 0.00 () Growth Distance 4.76 2.31 4.08 3.27 12.11 8.71 1.9 of Rust (mm) Evaluation Poor Poor Poor Poor Poor Poor Poor Comparative Comparative Comparative Comparative Comparative Comparative Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Base Oil 90.4 90.4 90.4 90.4 90.4 90.4 (parts by mass) Thickener 9.6 9.6 9.6 9.6 9.6 9.6 (parts by mass) Alkyl naphthalene 0.3 1.6 sulfonate metal salt 1 (parts by mass) Alkyl naphthalene 1.5 1.5 sulfonate metal salt 2 (parts by mass) Alkyl benzene sulfonate metal salt 1 (parts by mass) Alkyl benzene 0.3 2 0.4 sulfonate metal salt 2 (parts by mass) Extreme-Pressure 3.0 Agent (parts by mass) Total content 1.8 0.0 1.5 0.3 2.0 2.0 (% by mass) Content Ratio 0.00 0.00 0.00 1.00 1.00 0.20 () Growth Distance 3.54 4.08 1.36 4.76 1.09 4.13 of Rust (mm) Evaluation Poor Poor Poor Poor Poor Poor

(9) A numerical value of each material forming the lubricant compositions in Tables 1 and 2 represents parts by mass. Further, in Tables 1 and 2, Total Content represents the total content (% by mass) of the alkyl benzene sulfonate metal salt and the alkyl naphthalene sulfonate metal salt in the lubricant compositions; and Content Ratio represents the mass fraction () of the alkyl benzene sulfonate metal salt to the total mass of the alkyl benzene sulfonate metal salt and the alkyl naphthalene sulfonate metal salt.

(10) Further, the name of each material in Tables 1 and 2 is as follows.

(11) Base oil: Trimex N-08 (product name), produced by Kao Corporation, tri(normal C.sub.8-C.sub.10 alkyl) trimellitate;

(12) Thickener: A diurea compound (a reactant of 4,4-diphenylmethane diisocyanate and n-octylamine);

(13) Alkyl naphthalene sulfonate metal salt 1: NA-SUL BSN (product name), produced by Kusumoto Chemicals, Ltd., a dinonylnaphthalene sulfonate barium salt;

(14) Alkyl naphthalene sulfonate metal salt 2: NA-SUL Ca-1089 (product name), produced by Kusumoto Chemicals, Ltd., a dinonylnaphthalene sulfonate calcium salt;

(15) Alkyl benzene sulfonate metal salt 1: ADDITIN RC 4103 (product name), produced by Rhein Chemie Rheinau GmbH, a mono C.sub.15-C.sub.36 branched alkyl benzene sulfonate barium salt;

(16) Alkyl benzene sulfonate metal salt 2: ADDITIN RC 4220 (product name), produced by Rhein Chemie Rheinau GmbH, a di C.sub.10-C.sub.18 alkyl benzene sulfonate calcium salt; and

(17) Extreme-pressure additive: ADEKA-KIKU LUBE Z112, produced by ADEKA Corporation, ZnDTP (zinc dithiophosphate).

(18) From the results of Table 1, the evaluation results of the salt water immersion tests using the lubricant compositions of the present disclosure were Good or Fair, showing excellent rust-prevention in the case of application onto the aluminum alloy plate. In contrast, from the results of Table 2, the evaluation results of the salt water immersion tests not using the lubricant composition of the present disclosure were Poor, proving to be inferior in rust-prevention in the case of application onto the aluminum alloy plate.