JP3315002B2 - Diesel engine oil composition for construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diesel engine oil composition for construction machinery, and more particularly to a high cleanability,
The present invention relates to a diesel engine oil composition for construction machinery that can prevent corrosion of an engine bearing metal while maintaining wear resistance.

[0002]

2. Description of the Related Art Diesel engines for construction machinery are operated at a high output, a high load and at a high speed. The temperature inside the engine becomes high, and the deterioration of the engine oil is easily promoted. As the engine oil deteriorates, the deteriorated product causes corrosion of the bearing metal, which leads to a decrease in engine output. Among the engine oil additives, metal-type detergents are considered to be the most effective in solving such problems, and the ability of metal-type detergents neutralizes oxidized degraded substances and prevents corrosion of bearing metals. The way has been taken. However, in recent years, diesel engine oil for construction machinery has been used for a long time at a high output, a high load, and a high speed. In particular, when used for a long period of time, even higher cleanliness and wear resistance are required, and together with these performances, it is necessary to provide bearing metal corrosion prevention performance. Come. Diesel engines for construction machinery are generally understood to be similar to diesel engines for automobiles, and the same type of diesel engine oil has been used. However, diesel engines for construction machinery are used at much higher loads and higher speeds during normal operation and idling than diesel engines for automobiles, and there is also contamination with dust. Specifically, the load on the engine during normal (work) operation is 70% of the rated output.
It is used with the above high load. Furthermore, the engine speed is high, and the engine speed also differs depending on the engine. For example, during normal (work) operation, 2,000 r.p.m. p. m.
It is used at the above high speed, and even when idling without load, it prepares for the next work at 2,300 r.p.m. p. m. It is operated at the above high rotation. For this reason, the temperature inside the engine becomes high, and blow-by gas increases due to wear of parts due to dust, and deterioration of engine oil is easily promoted. As the engine oil deteriorates, there is a problem that the deteriorated product causes corrosion of the bearing metal, leading to a decrease in engine output.

[0003]

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, the present invention provides a diesel engine oil composition for construction machinery capable of preventing corrosion of a bearing metal of an engine while maintaining high cleanliness and wear resistance. The purpose is to provide things.

[0004]

Conventionally, the degraded substances involved in the corrosion of the bearing metal are acidic substances, and the total acid value is generally used as an index. When this value increases, it is considered that the deterioration of the oil has progressed. It has been an issue how to suppress this value. It is said that the cause of the increase in the total acid value is the incorporation of combustion products and blow-by gas into the oil and the deterioration of the engine oil itself. The present inventors have focused on not only neutralizing performance of combustion products but also emphasis on prevention of decomposition and oxidation stability of engine oil itself, and conducted intensive studies to achieve the above object. As a result, in the presence of an ashless dispersant,
By blending a specific metal-type detergent, a specific antiwear agent (zinc dialkyldithiophosphate), and a specific antioxidant, it was found that corrosion of the bearing metal can be prevented without impairing cleanliness and wear resistance. The present invention has been completed.

That is, the present invention relates to a mineral oil-based lubricating oil, a synthetic lubricating oil, or a base oil of a mixture of both, wherein calcium salicylate is contained in an amount of 1 to 20% by weight;

[0006]

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(Wherein R ₁ , R ₂ , R ₃ and R ₄
Is a primary alkyl group having 1 to 20 carbon atoms) 0.5 to 5% by weight of zinc dialkyldithiophosphate, 0.1 to 5% by weight of a hindered phenolic antioxidant,
And alkenyl succinimide or a derivative thereof,
It is intended to provide a diesel engine oil composition for construction machinery characterized by being contained at a ratio of 0% by weight.

Hereinafter, the present invention will be described in detail. Calcium salicylate, one of the essential components in the present invention, is obtained by alkylating phenol with an α-olefin having 10 to 18 carbon atoms, and then introducing a carboxyl group by a Kolbe-Schmidt reaction, followed by metathesis or the like to form an alkaline earth metal salt. Is used (UK Patent No. 73
No. 4,598, British Patent No. 732,622). Overbased is preferred for use in diesel engine oil compositions, especially having a base number of 150 mg.
KOH / g or more is best. The mixing ratio of calcium salicylate in the diesel engine oil composition for construction machinery of the present invention is 1 to 20% by weight, preferably 4 to 12%.
%, The effect is small if the mixing ratio is too small, and if too large, the cost is increased and it is economically disadvantageous.

The zinc dialkyldithiophosphate, which is one of the essential components in the present invention, has the general formula:

[0010]

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Wherein R ₁ , R ₂ , R ₃ and R ₄ are primary alkyl groups having 1 to 20 carbon atoms;
It is preferably a primary alkyl group having 2 to 14 carbon atoms, and particularly preferably a primary alkyl group having 3 to 10 carbon atoms.
The mixing ratio of zinc dialkyldithiophosphate in the diesel engine oil composition of the present invention is 0.5 to 5% by weight,
Preferably, the content is 1 to 3% by weight. If the blending ratio is too small, the effect is reduced, and if it is too large, the cost is increased and it is economically disadvantageous.

The alkenyl succinimide or a derivative thereof, which is one of the essential components in the present invention, is not particularly limited, and various ones which can be used as ashless dispersants for lubricating oils can be used. Specific examples of the alkenyl succinimide or a derivative thereof include, for example, a polyolefin having a molecular weight of about 300 to 5,000 such as polybutene, which is reacted with maleic anhydride to obtain monoalkenyl succinic anhydride, and further ethylenediamine, diethylenetriamine, dipropylenetriamine, Various alkenyl succinimides such as monoimide, diimide and triimide which are imidized using a polyamine such as triethylenetetramine and tetraethylenepentamine, and JP-B-42-8013 and JP-B-42-801
No. 4, JP-A-51-52381, JP-A-51-52381
And alkenyl succinimides are reacted with aldehydes, ketones, carboxylic acids, sulfonic acids, alkylene oxides, sulfur and the like as described in JP-A-130408. And alkenyl succinimide derivatives. Preferred among these alkenyl succinimides or derivatives thereof are those having a polybutene molecular weight of 1500 to 2000,
It is an alkenyl succinic monoimide imidized with triethylenetetramine or tetraethylenepentamine. These alkenylsuccinimides or derivatives thereof may be used alone or in combination of two or more. The blending ratio of the alkenyl succinimide or a derivative thereof in the diesel engine oil composition of the present invention is 1 to 20% by weight, preferably 4 to 16%.
%, The effect is small if the mixing ratio is too small, and if too large, the cost is increased and it is economically disadvantageous.

The hindered phenolic antioxidant, which is one of the essential components in the present invention, is synthesized by a known method, and has a kinematic viscosity at 40 ° C. of 500 mm ² / sec or less in solubility. It is preferable to use The compounding ratio of the hindered phenolic antioxidant in the diesel engine oil composition of the present invention is 0.1 to
The content is 5% by weight, preferably 1 to 3% by weight. If the mixing ratio is too small, the effect is reduced.

In the diesel engine oil composition for construction machinery of the present invention, in addition to the above, it is preferable to use a polyoxyethylene nonionic surfactant having an alkyl group having 1 to 30 carbon atoms. Specific examples of the polyoxyethylene nonionic surfactant include polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, polyoxyethylene nonyl phenyl ether,
Polyoxyethylene octyl phenyl ether, polyoxyethylene octyl stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene glycol monooleate, and the like, preferably Polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene higher alcohol ether, and polyoxyethylene octyl phenyl ether. The compounding ratio of the polyoxyethylene nonionic surfactant in the diesel engine oil composition for construction machinery of the present invention is 0.01 to 3% by weight, preferably 0.5 to 2% by weight, and the compounding ratio is too small. And the effect becomes smaller,
On the other hand, if the amount is too large, the cost increases and the economy becomes disadvantageous.

The above calcium salicylate, having 1 carbon atom
Base oils containing zinc primary dialkyldithiophosphates having up to 20 primary alkyl groups, alkenyl succinimides or derivatives, hindered phenolic antioxidants and, if necessary, polyoxyethylene nonionic surfactants, ,
It is sufficient that the lubricant has a normal lubricating oil viscosity and a viscosity index of 85 to 140, and a mineral oil type, a synthetic type, or a mixed type thereof can be used. In the case of a mineral oil-based lubricating oil, a refined one obtained by appropriately combining solvent refining, hydrorefining, and the like may be used. As the synthetic lubricating oil, for example, carbon number 3 to
Α-olefin oligomer which is a polymer of 12 α-olefins, sebacate including dioctyl sebacate, azelate, dialkyl diesters having 4 to 12 carbon atoms such as adipate, 1-trimethylolpropane,
Polyol esters including esters obtained from pentaerythritol and a monobasic acid having 3 to 12 carbon atoms,
Examples thereof include alkylbenzenes having an alkyl group having 9 to 40 carbon atoms. The mineral oil-based lubricating oil and the synthetic lubricating oil can be used alone or in combination of two or more.

In the diesel engine oil composition for construction machinery of the present invention, in addition to the above-mentioned additives, various known additives may be used as required, for example, polymethacrylates, ethylene-propylene copolymers, styrene. Various viscosity index improvers such as isoprene copolymer, hydrogenated styrene / isoprene copolymer or polyisobutylene, sulfurized oil and fat, diphenyl sulfide, methyltrichlorostearate, chlorinated naphthalene, iodinated benzyl, fluoroalkylpolysiloxane, naphthene Various extreme pressure agents such as lead acid, carboxylic acids including stearic acid, dicarboxylic acids, metal soaps, carboxylic acid amine salts,
Rust inhibitors such as metal salts of heavy sulfonic acids, carboxylic acid partial esters of polyhydric alcohols and phosphate esters,
Various friction modifiers such as higher fatty acids, higher alcohols, amines and esters, and various defoamers such as silicone oil can be used alone or in combination of two or more. In addition to these, various additives can be appropriately compounded.

In the method for preparing a diesel engine oil composition for construction machinery of the present invention, the base oil, the above-mentioned essential components and various additives may be appropriately mixed, and the mixing order is not particularly limited. Instead, the essential components may be sequentially mixed with the base oil, or the essential components may be preliminarily mixed and then mixed with the base oil. Further, various additives may be added to the base oil in advance, or may be added to essential components.

[0018]

Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited at all by these examples. In Examples, essential components and various additives were mixed with a base oil to prepare a diesel engine oil composition for construction machinery, and the metal corrosion resistance, cleanliness, and wear prevention performance were evaluated. The base oils, essential components, types of additives, and each evaluation test used in the preparation of the diesel engine oil compositions for construction machines of the respective examples and comparative examples are as follows.

1. Base oil In each of Examples and Comparative Examples, a so-called 150 neutral oil 70 obtained from a lubricating oil manufacturing process common in petroleum refining.
% Neutral oil and 30% by weight of 500 neutral oil were used. The viscosity index of the base oil was 102. 2. Additive Metal type detergent Commercially available calcium salicylate A (TBN = 170)
(Carbon number of alkyl group: 16) Commercially available calcium salicylate B (TBN = 150)
(Carbon number of alkyl group: 12) Commercially available calcium phenate (TBN = 250) Commercially available calcium sulfonate (TBN = 320) TBN is the total base number. Alkenyl succinimide Alkenyl succinate monoimide zinc dialkyldithiophosphate imidized with triethylenetetramine having a polybutene molecular weight of 1700, (i) a commercially available primary dialkyldithioline having an alkyl group having 4, 8, or 12 carbon atoms Zinc acid (ii) Commercially available zinc secondary dialkyldithiophosphate having an alkyl group having 4 carbon atoms (iii) Commercially available zinc allyl type dialkyldithiophosphate having an alkyl group having 8 carbon atoms

Antioxidant Commercially available hindered phenolic antioxidant (kinematic viscosity at 40 ° C .: 150 mm ² / sec) Commercially available aromatic amine-based antioxidant Commercially available dibutylhydroxytoluene (BHT) -based antioxidant Polyoxyethylene nonionic surfactant Commercially available polyoxyethylene nonyl phenyl ether Other additives All commercial products such as viscosity index improvers and defoamers

3. Evaluation Test (1) Metal Corrosion Resistance Test A test piece (3 types of JIS H-5115 lead bronze castings) was put in 100 g of the test oil, and the test pieces were placed at 120 ° C and 140 ° C for 24 hours.
Soak for 0 hours. The test piece is taken out, and the degree of discoloration and the change in test piece weight are measured. The following is an estimate of the score for each evaluation item. A comprehensive evaluation of the metal corrosion resistance of the test oil was performed using the measured values of both. When the two scores were different, a comprehensive evaluation was scored in consideration of the color tone and the degree of weight change.

Degree of discoloration A: No discoloration B: Brown C: Gray to black D: Black and peeling Test piece weight change A: Less than ± 1 mg B: ± 1 to less than 10 mg C: ± 10 to less than 50 mg D: ± 50 mg that's all

(2) Evaluation Test of Cleanliness and Wear Prevention Performance An in-line 6 cylinder, 5 liter diesel engine for construction machinery was operated under the following operating conditions. Rotation speed 2300 rpm Oil temperature 120 ° C. Test time 200 hr, 400 hr The cleanliness and wear of each part of the engine were evaluated. The cleanliness was evaluated according to the evaluation method JPI-5S-15-85. The cleanliness and wear of each part of the engine are indicated by relative values with 10 points of commercially available oil. The value of 10 points or more of cleanliness is
Further, a value of 10 points or less in the amount of abrasion indicates that it is superior to a commercially available oil.

Examples 1 to 6 The additives shown in Table 1 were blended with the above base oils in the proportions (% by weight) shown in the upper part of Table 1 to prepare diesel engine oil compositions for construction machinery. The evaluation values of the obtained diesel engine oil composition for construction machinery are as shown in the lower part of Table 1. Table 4 shows the evaluation values of these diesel engine oil compositions for construction equipment in a deteriorated state, and Table 5 shows the results of evaluation tests using the diesel engine for construction equipment.

[0025]

[Table 1]

Comparative Examples 1 to 8 The additives shown in Tables 2 and 3 were added to the above base oils.
And a diesel engine oil composition was prepared by blending at the ratio (% by weight) shown in the upper part of the above. Tables 2 and 3 show the results of the evaluation test using the obtained diesel engine oil composition and a commercially available diesel engine oil. In addition, Table 4 shows the evaluation values of these diesel engine oil compositions in the deteriorated state, and Table 5 shows the results of the evaluation test using the diesel engine. The compositions in Examples and Comparative Examples, including commercially available products, have a viscosity of SAE15W40 (automotive lubricant viscosity number by the American Society of Automotive Engineers), and a Ca content of 0.40 to 0.48 for elements in oil. Wt%, Zn content 0.10-0.13 wt%, P content 0.09-0.1
It was 1% by weight. In Tables 1, 2 and 3, the balance of the blending ratio of the oil is indicated as being balanced so that the total amount of the various additives and the base oil is adjusted to 100% by weight. .

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

[Table 4] Metal corrosion resistance test results

[0030]

[Table 5] Evaluation test results of cleanliness and wear prevention performance

Table 4 shows Examples 1 and 2 and Comparative Example 1.
(Commercial oil) is slightly, moderately and severely degraded, and the metal corrosion resistance test results obtained by replacing the total acid value with a metal corrosion resistance test are listed. The evaluation test results are described. As shown in Tables 4 and 5, the metal corrosion resistance in the deteriorated state of the diesel engine oil composition and the evaluation using a diesel engine for construction machinery were performed.
And 3 showed better results than Comparative Example 1. In particular, Example 1 showed much better results than Comparative Example 1. In particular, in the evaluation by the engine test, even when the test time was doubled (400 hours), the performance was equal to or longer than the normal use time (200 hours) of the commercial oil (Comparative Example 1).

[0032]

According to the diesel engine oil composition for construction machinery of the present invention, a specific metal-type detergent, a specific antiwear agent (zinc dialkyldithiophosphate) and a specific By compounding antioxidants,
It is possible to achieve a high level of improvement in bearing metal corrosion prevention, cleanliness, and wear prevention in diesel engines for construction machinery. The diesel engine oil composition for construction machinery of the present invention is extremely useful in practice.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C10M 149: 02 C10M 149: 02 159: 20) 159: 20) C10N 10:04 C10N 10:04 30:04 30:04 30: 06 30:06 30:10 30:10 30:12 30:12 40:02 40:02 40:25 40:25 (72) Inventor Minoru Takei 1134-2 Gongendo, Satte City, Saitama Prefecture Cosmo Research Institute, Inc. Inside the R & D Center (72) Inventor Yoshihiro Matsudaira 1134-2 Gongendo, Satte-city, Saitama Cosmo Research Institute, Inc. (56) References JP-A-61-166892 (JP, A) JP-A-1 JP-A-58-38792 (JP, A) JP-A-5-230485 (JP, A) JP-A-5-163497 (JP, A) JP-A-62-181397 (JP, A) ) JP-A-6-184578 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C10M 167/00 C10M 129/10-129/14 C10M 133/16 C10M 133/56 C10M 137/10 C10M 149/02 C10M 149/06 C10M 159/20 C10N 10:04 C10N 30:04-30:06 C10N 30:10-30 : 12 C10N 40:02 C10N 40:25-40:28

Claims (1)

(57) [Claims] 1. A mineral oil-based lubricating oil, a synthetic lubricating oil, or a base oil of a mixture thereof, containing 1 to 20% by weight of calcium salicylate and a general formula of the following chemical formula 1. (Wherein R ₁ , R ₂ , R ₃ and R ₄ are primary alkyl groups having 1 to 20 carbon atoms), and 0.5 to 5% by weight of zinc dialkyldithiophosphate represented by the formula: A diesel engine oil composition for construction machinery comprising 0.1 to 5% by weight of an antioxidant and 1 to 20% by weight of an alkenyl succinimide or a derivative thereof.