Lubricant composition, mechanical device including lubricant composition, and method of producing lubricant composition

Abstract

Provided is a lubricant composition comprising a lubricant base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D), and a secondary amine compound (E), and having a flash point of 172° C. or higher.

Claims

1. A lubricating oil composition, comprising: a lubricant base oil, a neutral phosphorus-based compound, an acidic phosphorus-based compound, a sulfur-based compound, and a secondary amine compound, wherein the lubricating oil composition has a flash point of 172° C. or higher, wherein the acidic phosphorus-based compound is an acidic phosphoric acid ester, and wherein the lubricating oil composition has an abrasion mark diameter of less than 0.48 mm as measured under test conditions of a rotation speed of 1800 rpm, a test temperature of 80° C., a load of 392N and a test time of 30 minutes in accordance with the method described in ASTM D4172.

2. The lubricating oil composition according to claim 1, wherein the secondary amine compound is a compound of formula (1): ##STR00005## wherein R.sup.1 and R.sup.2 each independently represent a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms.

3. The lubricating oil composition according to claim 2, wherein R.sup.1 and R.sup.2 each independently represent a group of formula (2):
—(CH.sub.2)n—OH  (2) wherein n represents an integer of 1 to 8.

4. The lubricating oil composition according to claim 1, wherein a content of the secondary amine compound is 0.01% by mass to 0.5% by mass based on a total amount of the lubricating oil composition.

5. The lubricating oil composition according to claim 1, wherein the lubricant base oil has a flash point of 172° C. or higher.

6. The lubricating oil composition according to claim 1, which is suitable for a mechanical device.

7. The lubricating oil composition according to claim 6, wherein the mechanical device is a hydraulic device, a stationary transmission, an automotive transmission or a motor/battery cooling device.

8. A mechanical device, comprising: the lubricating oil composition according to claim 1.

9. The mechanical device according to claim 8, which is a hydraulic device, a stationary transmission, an automotive transmission or a motor/battery cooling device.

10. A method for producing a lubricating oil composition having a flash point of 172° C. or higher, the method comprising: mixing a lubricant base oil, a neutral phosphorus-based compound, an acidic phosphorus-based compound, a sulfur-based compound and a secondary amine compound, wherein the acidic phosphorus-based compound is an acidic phosphoric acid ester, and wherein the lubricating oil composition has an abrasion mark diameter of less than 0.48 mm as measured under test conditions of a rotation speed of 1800 rpm, a test temperature of 80° C., a load of 392N and a test time of 30 minutes in accordance with the method described in ASTM D4172 .

11. The lubricating oil composition according to claim 1, which consists of the lubricant base oil, the neutral phosphorus-based compound, the acidic phosphorus-based compound, the sulfur-based compound, and the secondary amine compound.

12. The method according to claim 10, wherein the lubricating oil composition consists of the lubricant base oil, the neutral phosphorus-based compound, the acidic phosphorus-based compound, the sulfur-based compound, and the secondary' amine compound.

13. The lubricating oil composition according to claim 1, wherein the acidic phosphoric acid ester is an aliphatic acidic phosphoric acid ester.

14. The lubricating oil composition according to claim 1, wherein, based on a total amount of the composition: a content of the lubricant base oil is 65 to 97% by mass a content of the neutral phosphorus-based compound is 2.5% by mass or less, a content of the acidic phosphorus-based compound is 0.8% by mass or less, a content of the sulfur-based compound is 0.3% by mass or less, and a content of the secondary amine compound is 0.01% by mass to 0.5% by mass.

15. The lubricating oil composition according to claim 1, wherein the lubricating oil composition has an abrasion mark diameter of 0.43 mm to 0.45 mm as measured under test conditions of a rotation speed of 1800 rpm, a test temperature of 80° C., a load of 392N and a test time of 30 minutes in accordance with the method described in ASTM D4172.

16. The lubricating oil composition according to claim 1, wherein the acidic phosphoric acid ester is an aliphatic acidic phosphoric acid ester, wherein the lubricating oil composition has an abrasion mark diameter of 0.43 mm to 0.45 mm as measured under test conditions of a rotation speed of 1800 rpm, a test temperature of 80° C., a load of 392N and a test time of 30 minutes in accordance with the method described in ASTM D4172, and wherein, based on a total amount of the composition: a content of the lubricant base oil is 65 to 97% by mass a content of the neutral phosphorus-based compound is 2.5% by mass or less, a content of the acidic phosphorus-based compound is 0.8% by mass or less, a content of the sulfur-based compound is 0.3% by mass or less, and a content of the secondary amine compound is 0.01% by mass to 0.5% by mass.

17. The method according to claim 10, wherein the acidic phosphoric acid ester is an aliphatic acidic phosphoric acid ester.

18. The method according to claim 10, wherein, in the lubricating oil composition and based on a total amount of the composition: a content of the lubricant base oil is 65 to 97% by mass a content of the neutral phosphorus-based compound is 2.5% by mass or less, a content of the acidic phosphorus-based compound is 0.8% by mass or less, a content of the sulfur-based compound is 0.3% by mass or less, and a content of the secondary amine compound is 0.01% by mass to 0.5% by mass.

19. The method according to claim 10, wherein the lubricating oil composition has an abrasion mark diameter of 0.43 mm to 0.45 mm as measured under test conditions of a rotation speed of 1800 rpm, a test temperature of 80° C., a load of 392N and a test time of 30 minutes in accordance with the method described in ASTM D4172.

20. The method according to claim 10, wherein the acidic phosphoric acid ester is an aliphatic acidic phosphoric acid ester, wherein the lubricating oil composition has an abrasion mark diameter of 0.43 mm to 0.45 mm as measured under test conditions of a rotation speed of 1800 rpm, a test temperature of 80° C., a load of 392N and a test time of 30 minutes in accordance with the method described in ASTM D4172, and wherein, in the lubricating oil composition and based on a total amount of the composition: a content of the lubricant base oil is 65 to 97% by mass a content of the neutral phosphorus-based compound is 2.5% by mass or less, a content of the acidic phosphorus-based compound is 0.8% by mass or less, a content of the sulfur-based compound is 0.3% by mass or less, and a content of the secondary amine compound is 0.01% by mass to 0.5% by mass.

Description

EXAMPLES

(1) Hereinafter, the present invention will be more specifically described by way of examples. However, the present invention is not limited thereto.

(2) The characteristics and performances in the Examples and Comparative Examples were measured as described below.

(3) (1) Kinetic Viscosity

(4) The kinetic viscosity at 40° C. and the kinetic viscosity at 100° C. were measured using a glass capillary viscometer in accordance with JIS-K-2283:2000.

(5) (2) Viscosity Index

(6) The measurement was carried out by the method in accordance with JIS-K-2283:2000.

(7) (3) Flash Point

(8) The measurement was carried out by the C.O.C. method in accordance with HS-K-2265.

(9) (4) Abrasion Resistance

(10) The abrasion resistance was evaluated by the Shell 4-ball abrasion test. Specifically, the abrasion resistance between metals was evaluated by measuring an abrasion mark diameter under test conditions of a rotation speed of 1800 rpm, a test temperature of 80° C., a load of 392N and a test time of 30 minutes in accordance with the method described in ASTM D4172. The smaller the abrasion mark diameter is, the better the abrasion resistance between metals is.

(11) (5) Seizure Resistance

(12) The weld load (WL) (N) was measured under conditions of a rotation speed of 1800 rpm and room temperature in accordance with ASTM D2783-03 (2014). The larger this value is, the better the seizure resistance is.

(13) (6) Friction Properties

(14) The friction coefficient between metals was measured by the LFW-1 test in accordance with the JASO method (high load method) M358:2005. The smaller this value is, the better the seizure resistance is.

Examples 1-3 and Comparative Examples 1-6

(15) The lubricating oil composition was prepared using the lubricant base oil (A), the neutral phosphorus-based compound (B), the acidic phosphorus-based compound (C), the sulfur-based compound (D), the amine compound, etc. described below according to the composition shown in Table 1. The respective components constituting the lubricating oil composition described in Table 1 are as described below.

(16) [Lubricant Base Oil (A)]

(17) Mineral oil-1: a mineral oil having a kinetic viscosity at 100° C. of 2.4 mm.sup.2/s, a viscosity index of 110 and a flash point of 186° C.

(18) Mineral oil-2: a mineral oil having a kinetic viscosity at 100° C. of 2.4 mm.sup.2/s, a viscosity index of 105 and a flash point of 176° C.

(19) Mineral oil-3: a mineral oil having a kinetic viscosity at 100° C. of 2.4 mm.sup.2/s, a viscosity index of 100 and a flash point of 170° C.

(20) Synthetic oil-1: a synthetic oil having a kinetic viscosity at 100° C. of 2.4 mm.sup.2/s, a viscosity index of 110 and a flash point of 186° C.

(21) [Neutral Phosphorus-Based Compound (B)]

(22) Tricresyl phosphate (TCP)

(23) [Acidic Phosphorus-Based Compound (C)]

(24) Dioleyl acid phosphate

(25) [Sulfur-Based Compound (D)]

(26) 2,5-bis(1,1,3,3-tetramethylbutyldithio)-1,3,4-thiadiazole

(27) [Secondary Amine Compound (E)]

(28) Diethanolamine (R.sup.1 and R.sup.2 in formula (1) are a group of formula (2), and n in formula (2) is 2)

(29) [Primary Amine Compound]

(30) Phosphoric acid ester amine salt

(31) Further, the other additives (remaining portion) contained in the compositions of the Examples and Comparative Examples consist of a viscosity index improver, an antioxidant, a detergent dispersant, a pour point depressant, a defoaming agent, etc.

(32) TABLE-US-00001 TABLE 1 Compara- Compara- Compara- tive tive tive Exam- Exam- Exam- Exam- Exam- Exam- ple 1 ple 2 ple 3 ple 1 ple 2 ple 3 Compo- Lubricant Mineral oil-1 95.00 95.80 95.20 nent base oil (A) Mineral oil-2 95.00 compo- Mineral oi1-3 95.00 sition Synthetic oil-1 95.00 (% by Neutral phosphorus-based compound (B) 0.80 0.80 0.80 0.80 0.80 mass) Amount of phos- mass ppm 660 660 660 660 0 660 phorus derived from compo- nent (B) Acidic phosphorus-based compound (C) 0.20 0.20 0.20 0.20 0.20 Amount of phos- mass ppm 120 120 120 120 120 0 phorus derived from compo- nent (C) Sulfur-based compound (D) 0.10 0.10 0.10 0.10 0.10 0.10 Amount of sulfur mass ppm 300 300 300 300 300 300 derived from component (D) Secondary amine compound (E) 0.10 0.10 0.10 0.10 0.10 0.10 Primary amine compound Other additives Re- Re- Re- Re- Re- Re- main- main- main- main- main- main- ing ing ing ing ing ing amount amount amount amount amount amount Total 100 100 100 100 100 100 Charac- Kinetic viscos- mm.sup.2/s 10.80 10.82 10.79 10.81 10.60 10.70 teristics ity at 40° C. Kinetic viscos- mm.sup.2/s 2.85 2.83 2.85 2.82 2.81 2.82 ity at 100° C. Viscosity index 111 107 112 105 110 109 Flash point ° C. 186 176 188 170 186 188 Perfor- Abrasion mm 0.44 0.45 0.43 0.46 0.65 0.48 mance resistance Seizure N 618 618 618 618 618 490 resistance Friction 0.090 0.092 0.089 0.089 0.088 0.087 properties Compara- Compara- Compara- tive tive tive Exam- Exam- Exam- ple 4 ple 5 ple 6 Compo- Lubricant Mineral oil-1 95.10 95.10 95.00 nent base oil (A) Mineral oil-2 compo- Mineral oi1-3 sition Synthetic oil-1 (% by Neutral phosphorus-based compound (B) 0.80 0.80 0.80 mass) Amount of phos- mass ppm 660 660 660 phorus derived from compo- nent (B) Acidic phosphorus-based compound (C) 0.20 0.20 0.20 Amount of phos- mass ppm 120 120 120 phorus derived from compo- nent (C) Sulfur-based compound (D) 0.10 0.10 Amount of sulfur mass ppm 0 300 300 derived from component (D) Secondary amine compound (E) 0.10 Primary amine compound 0.10 Other additives Remain- Remain- Remain- ing ing ing amount amount amount Total 100 100 100 Charac- Kinetic viscos- mm.sup.2/s 10.72 10.74 10.73 teristics ity at 40° C. Kinetic viscos- mm.sup.2/s 2.82 2.82 2.82 ity at 100° C. Viscosity index 108 108 109 Flash point ° C. 186 186 186 Perfor- Abrasion mm 0.48 0.48 0.48 mance resistance Seizure N 490 618 618 resistance Friction 0.087 0.110 0.110 properties

(33) As shown in Table 1, when Examples 1-3 and Comparative Examples 2-6 were compared to each other, it was found that the lubricating oil composition containing all of the lubricant base oil (A), the neutral phosphorus-based compound (B), the acidic phosphorus-based compound (C), the sulfur-based compound (D) and the secondary amine compound (E) has superior performance with respect to all of abrasion resistance, seizure resistance and friction properties.

(34) Further, when Examples 1-3 and Comparative Examples 5-6 were compared to each other, it was found that when the secondary amine compound (E) is used, friction properties of the lubricating oil composition obtained are improved.

(35) When Examples 1-3 and Comparative Example 1 were compared to each other, it was found that when a base oil having a high flash point is used as the lubricant base oil, the lubricating oil composition obtained has a high flash point. Further, in Examples 1-3, when a base oil having a high flash point was used as the lubricant base oil (A), the flash point of the lubricating oil composition was high, and in particular, in Examples 1 and 3, since the lubricant base oil (A) had a flash point of 186° C. or higher, the flash point of the lubricating oil composition obtained was also high.