GREASE COMPOSITION

Abstract

An object of the present invention is to provide a grease composition which has little influence on the environment and has good rust prevention and water resistance against salt water such as sea water. The grease composition comprises a biodegradable base oil and a rust-preventive agent comprising a calcium sulfonate complex and a sorbitan fatty acid ester, wherein a total content of biodegradable organic substances in the grease composition is 75% by mass or more, and wherein a content of the rust-preventive agent is 2.5 to 30% by mass.

Claims

1. A grease composition comprising: a biodegradable base oil and a rust-preventive agent comprising a calcium sulfonate complex and a sorbitan fatty acid ester, wherein a total content of biodegradable organic substances in the grease composition is 75% by mass or more, and a content of the rust-preventive agent is 2.5 to 30% by mass.

2. The grease composition of claim 1, wherein a content of the calcium sulfonate complex with respect to the sorbitan fatty acid ester (a content of the calcium sulfonate complex/a content of the sorbitan fatty acid ester) is 0.5 to 5.0.

3. The grease composition of claim 1, comprising a biodegradable base oil, a thickener, and a rust-preventive agent comprising a calcium sulfonate complex and a sorbitan fatty acid ester, wherein a total content of biodegradable organic substances in the grease composition is 75% by mass or more, and a content of the rust-preventive agent is 2.5 to 30% by mass.

4. The grease composition of claim 3, wherein a content of the thickener is 2,0 to 20% by mass.

5. The grease composition of claim 3, wherein e thickener is one or more selected from the group consisting of a lithium soap, a lithium composite soap, and a urea-based compound.

6. The grease composition of claim 3, wherein a worked penetration of the grease composition is 265 to 295.

7. The grease composition of claim 1, comprising a biodegradable base oil, a biodegradable wax, a tackiness agent, and a rust-preventive agent comprising a calcium sulfonate complex and a sorbitan fatty acid ester, wherein a total content of biodegradable organic substances in the grease composition is 75% by mass or more, a content of the rust-preventive agent is 2.5 to 30% by mass, and a melting point of the grease composition is 50 C. to 100 C.

8. The grease composition of claim 10, wherein a content of the tackiness agent is 1.0 to 25% by mass.

9. The grease composition of claim 7, wherein a content of the biodegradable wax in a total amount of the biodegradable base oil and the biodegradable wax is 6.0 to 40% by mass.

10. The grease composition of claim 1, further comprising a tackiness agent.

11. The grease composition of claim 3, wherein the thickener is one or more selected from the group consisting of a lithium soap, a urea-based compound, a lithium composite soap, a calcium soap, a sodium soap. an aluminum soap. a sodium terephthalamate, a fluorine, an organized bentonite, and a silica gel.

12. The grease composition of claim 10, wherein the tackiness agent is one or more selected from the group consisting of a polyisobutene, a polyisobutylene, and an alpha-olefin copolymer.

Description

EXAMPLE

[0073] Hereinafter, the present invention will be described more specifically with reference to Examples. The present invention is in no way limited to these Examples.

[0074] Hereinafter, various materials used in Examples and Comparative examples are collectively shown.

[0075] Synthetic ester oil: Synative ES TMP 05/320 (trimethylol propane complex ester, kinematic viscosity (40 C.): 326 mm.sup.2/s) manufactured by BASF Japan Ltd.

[0076] Vegetable oil: Castor Oil No.1 (kinematic viscosity (40 C.): 240 mm.sup.2/s) manufactured by Hokoku Corporation

[0077] Wax: Paraffin Wax 155F manufactured by Nippon Seiro Co., Ltd.

[0078] Lithium soap: a lithium soap formed by reaction of hydroxystearic acid and 12-hydroxystearic acid with lithium hydroxide

[0079] Lithium complex soap: a lithium complex soap formed by reaction of a mixture of 12-hydroxystearic acid and azelaic acid with lithium hydroxide

[0080] Diurea compound: a diurea compound formed by reaction of a mixture of cyclohexylamine and stearylamine with 4,4-diphenylmethane diisocyanate

[0081] Tackiness agent: Idemitsu Polybutene 2000H manufactured by Idemitsu Kosari Co., Ltd.

[0082] Calcium sulfonate complex: Daphne Multilex WR manufactured by Idemitsu Kosan. Co., Ltd.

[0083] Sorbitan fatty acid ester 1: Emazol 0-10V sorbitan monooleate) manufactured by Kao Corporation

[0084] Sorbitan fatty acid ester 2: Emazol 0-30V (sorbitan trioleate) manufactured by Kao Corporation

Examples 1 to 10 and Comparative Examples 1 to 5

[0085] A grease composition was prepared according to the formulation shown in Table 1. The obtained grease composition was evaluated as follows. The evaluation results are shown in Table 1.

<Measurement of Worked Penetration>

[0086] A value of the worked penetration was determined by measuring a depth (mm) reached by dropping a cone attached to a penetration meter into a grease composition for testing and penetrating it therethrough for 5 seconds under the environment of 25 C. according to JIS K 2220 7 and multiplying the measured value by 10.

<Neutral Salt Water Spray Test>

[0087] A rust generation rate after storing a test piece coated with a grease composition for testing (the coating method conforms to JIS K 2220 21) in an apparatus sprayed with neutral salt water for a specified time under an environment of 35 C. was examined conforming to JIS K 2246 6.35. Table 1 shows spraying time of salt water where the rust generation rate was 0%. 120 hours or more shall be a performance target value.

<Water Washing Resistance Test>

[0088] A mass of grease washed out with water relative to the amount of grease of 100% by mass before testing was measured under environments of 38 C. and 79 C., conforming to JIS K 2220 16. The smaller the mass is, the better the water resistance is.

<Oil Separation Degree>

[0089] Oil separation degree when the grease composition was left to stand for 24 hours at 100 C. was measured conforming to JIS K 2220 11. The smaller the mass is, the better the storage stability is.

TABLE-US-00001 TABLE 1 Example 1 2 3 4 5 6 7 8 9 10 Synthetic ester oil 87 87 87 85.5 65 65 70 66.5 63 65 Vegetable oil 20.5 20.5 20.5 20.5 Lithium soap 10 10 10 10 10 10 15 8.0 Lithium composite soap 12 Diurea compound 10 Calcium sulfonate complex 1.5 1.5 2.0 3.0 3.0 3.0 10 17 3.0 3.0 Sorbitan fatty acid ester 1 1.5 1.0 1.5 1.5 5.0 8.5 1.5 1.5 Sorbitan fatty acid ester 2 1.5 1.5 Total 100 100 100 100 100 100 100 100 100 100 Content of biodegradable substance 88.5 88.5 88 87 87 87 75 75 85 87 Evaluation Worked penetration (25 C.) 275 275 275 280 280 280 240 285 280 290 Salt water spray test (h) 120 120 144 300 or 300 or 300 or 300 or 300 or 300 or 120 more more more more more more Water washing resistance 2 2 1 1 1 1 1 1 3 1 (38 C., 1 h) (% by mass) Water washing resistance 4 4 3 3 3 3 1 3 4 2 (79 C., 1 h) (% by mass) Oil separation degree 0.8 0.8 0.8 0.7 0.7 0.7 0.5 0.9 0.8 0.5 (100 C., 24 h) (% by mass) Comparative example 1 2 3 4 5 Synthetic ester oil 65.5 88 64 87 87 Vegetable oil Lithium soap 9.0 10 15 10 10 Lithium composite soap Diurea compound Calcium sulfonate complex 17 1.0 10.5 3.0 Sorbitan fatty acid ester 1 3.0 Sorbitan fatty acid ester 2 8.5 1.0 10.5 Total 100 100 100 100 100 Content of biodegradable substance 74 89 74.5 87 90 Evaluation Worked penetration (25 C.) 285 285 240 275 280 Salt water spray test (h) 300 or 72 120 or 72 48 more more Water washing resistance 1 1 1 1 3 (38 C., 1 h) (% by mass) Water washing resistance 3 4 2 4 6 (79 C., 1 h) (% by mass) Oil separation degree 0.9 0.9 0.5 0.6 0.8 (100 C., 24 h) (% by mass)

[0090] From the results shown in Table 1, it can be seen that the grease composition of the present invention has good rust prevention, water resistance, and storage stability against salt water.

Examples 11 to 17 and Comparative Examples 6 to 10

[0091] A grease composition was prepared according to the formulation shown in Table 2. The obtained grease composition was evaluated as follows. The evaluation results are shown in Table 2.

<Measurement of Melting Point>

[0092] A melting point of the grease composition was measured conforming to JIS K 2235.

<Neutral Salt Water Spray Test>

[0093] A rust generation rate after storing a test piece coated with a grease composition for testing (the coating method conforms to JIS K 2220 21) in an apparatus sprayed with neutral salt water for a specified time under an environment of 35 C. was examined conforming to JIS K 2246 6.35. Table 2 shows spraying time of salt water where the rust generation rate was 0%. 240 hours or more shall be a performance target value.

TABLE-US-00002 TABLE 2 Example Comparative example 11 12 13 14 15 16 17 6 7 8 9 10 Synthetic ester oil 77 77 75.5 67 62.5 67 81 82 61.5 56 78.5 78.5 Wax 10 10 10 10 10 20 6.0 5.0 10 10 10 10 Tackiness agent 10 10 10 20 5.0 10 15 10 25.5 10 10 10 Calcium sulfonate complex 1.5 1.5 3.0 1.5 1.5 1.5 1.5 1.5 1.5 16 3.0 Sorbitan fatty acid ester 1 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 8.0 3.0 Sorbitan fatty acid ester 2 1.5 Total 100 100 100 100 100 100 100 100 100 100 100 100 Content of 88.5 88.5 87 78.5 80 87 88.5 88.5 74.5 74 90 88.5 biodegradable substance Evaluation Melting Point 75 75 77 78 82 82 52 48 85 92 72 72 ( C.) Salt water 300 or 300 or 300 or 300 or 300 or 300 or 264 or 240 or 300 or 300 or 240 or 240 or spray test (h) more more more more more more more more more more more more

[0094] From the results shown in Table 2, it can be seen that the grease composition of the present invention has a good rust prevention against salt water.

INDUSTRIAL APPLICABILITY

[0095] The grease composition of the present invention has little influence on the environment and has good rust prevention and water resistance against salt water such as sea water, and thus it is useful particularly as a lubricant for a wire rope that comes into contact with water.