JPS63223094A - Lubricant base oils and compositions for internal combustion engines - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to lubricating base oils and compositions for internal combustion engines, and more specifically, lubricating base oils and compositions for internal combustion engines that do not deteriorate and function stably even in a nitrogen oxide (NoX) gas atmosphere. The present invention relates to lubricating base oils and compositions containing the base oils.

[Prior Art and Problems to be Solved by the Invention] Generally, part of the combustion gas in an internal combustion engine leaks into the crankcase as blow-by gas from between the piston and the cylinder. The combustion gas q contains NOx gas at a considerable concentration, and there is a problem in that this deteriorates the crankcase oil (internal combustion engine oil).

Incidentally, recently, an increasing number of automobiles are equipped with reduction catalysts such as three-way catalysts in order to comply with exhaust gas regulations, and it has become permissible to operate internal combustion engines more harshly (high speed, high output).

As a result, NO of combustion gas leaks into the crankcase.
The x gas concentration tends to increase. Furthermore, with the aim of improving fuel efficiency from the perspective of energy conservation, the weight of automobile bodies is being promoted, and crankcases are also becoming smaller, and with this, crankcase oil (internal combustion engine oil)
The amount of is also decreasing.

For these reasons, the concentration of NOx gas in crankcase oil has increased significantly in recent years, and its influence is extremely large. Abnormal deterioration such as black sludge occurs in internal combustion engine oil in a short period of time, and improvement of this problem is desired.

[Means for solving problems]

Therefore, the inventor of the present invention has conducted extensive research in order to solve the problems of conventional internal combustion engine oils as described above and to develop an internal combustion engine oil that is stable against NO and gas. As a result, it was discovered that a lubricating base oil with specific properties and a product containing a phenolic antioxidant and an organic molybdenum compound could achieve the desired purpose, leading to the completion of the present invention. .

That is, the present invention has a viscosity of 2 to 5 Qc at 100°C.
Provided is a lubricating base oil (first invention) for internal combustion engines, characterized in that it is St and has an aromatic content of 2% or less, and the base oil (A) and (B) are phenolic oxidized. Lubricating oil composition for internal combustion engines containing an inhibitor (second invention)
', a lubricating oil composition for internal combustion engines (third invention) containing this base oil (A) and (C) an organomolybdenum compound, further comprising this base oil (A), (B) a phenolic antioxidant, and ( C) A lubricating oil composition for internal combustion engines containing an organic molybdenum compound (fourth invention) is also provided.

The lubricating base oil of the present invention is commonly used in all of the first to fourth inventions, and its properties include a viscosity of 2 to 5 QcSt at 100°C, preferably 3 ~20 cSt. If the viscosity is less than 2 cSt, there is a disadvantage that there is a large amount of evaporated Ml, and if it exceeds 50 cSt, the power loss due to viscous resistance is too large, which is not preferable.

Furthermore, the lubricating base oil of the present invention has an aromatic content (% Ca
) is 2% or less, preferably 1% or less. Here, if the aromatic content exceeds 2%, there is a disadvantage that deterioration is significant in an NO or gas atmosphere. The other properties of this lubricating base oil are those required for conventional lubricating oils for internal combustion engines, such as: ■Appropriate viscosity characteristics, ■Good oxidation stability, ■Good cleaning and dispersion properties, and ■Good It is preferable to have anti-rust/corrosion properties, (1) good low-temperature fluidity, etc., specifically, a viscosity index of 80 or more and a pour point of -10°C or less, especially -20°C.
Hereinafter, a more preferable condition is that the total acid value is 0.1 KOI (7 g or less).

As the lubricating base oil of the present invention, various oils including mineral oils and synthetic oils can be used as long as they have the above-mentioned properties, and there are no particular limitations.

Specific examples of mineral oils that can be used as the lubricant base oil of the present invention include distillates obtained by atmospheric distillation of paraffinic crude oils and intermediate base crude oils, or distillation of residual oils from atmospheric distillation under reduced pressure. Examples include refined oil obtained by refining oil according to a conventional method, and deeply dewaxed oil obtained by further deep dewaxing treatment after refining. There are no particular restrictions on the purification method at this time, and various methods can be considered. Usually (a) hydrogenation treatment, (b) dewaxing treatment (solvent dewaxing or hydrogen dewaxing).

(c) Solvent extraction treatment, (d) alkaline distillation or sulfuric acid washing treatment, and (e) clay treatment are carried out singly or in combination in an appropriate order. It is also effective to repeat the same process in multiple stages. For example, ■ a method in which distillate oil is hydrotreated or hydrotreated and then subjected to alkaline distillation or sulfuric acid washing treatment; ■ a method in which distillate oil is hydrotreated and then dewaxed; ■ distillation A method in which oil is subjected to solvent extraction and then hydrogenated, ■ A method in which distillate oil is subjected to two or three stages of hydrogenation treatment, or a method in which the distillate is subsequently subjected to alkaline distillation or sulfuric acid washing treatment; After the treatment as in (2), there is a method of dewaxing the oil again to obtain a deeply dewaxed oil.

Whichever method is used, the properties of the lubricating base oil obtained may be adjusted to have the above-mentioned viscosity and %CA.

In particular, mineral oil obtained by deep dewaxing treatment is suitable as the lubricating oil base oil in the present invention. This deep dewaxing treatment is performed by a solvent membrane waxing method under severe conditions, a catalytic hydrogenation dewaxing method using a zeolite catalyst, or the like.

In addition to the above-mentioned mineral oils, the lubricating base oil of the present invention may be synthetic oils such as alkylbenzene, polybutene, or poly(α-olefin), or may be a mixture thereof.

In the first invention, the above-mentioned lubricating oil base oil is used alone as a lubricating oil for internal combustion engines, and this lubricating oil alone exhibits sufficient stability against NO and gas. A lubricating oil composition is prepared by adding (B) a phenolic antioxidant to a base oil (A).

Here, as the phenolic antioxidant (B), various kinds can be used, and there are no particular limitations.

Specifically, 4,4′-methylenebis(2,6-ditertiary-butylphenol); 4+4”-bis(2,6
-ditert-butylphenol); 4,4'-bis(2-methyl-6-tert-butylphenol);
2,2'-methylenebis(4-ethyl-6-tert-butylphenol);2,2'-methylenebis(4-
Methyl-6-tert-butylphenol); 4+4
'-Butylidenebis(3-methyl-6-tert-butylphenol)? 4.4”-isopropylidene bis(
2,6-ditertiary-butylphenol); 2゜2'
-methylenebis(4-methyl-6-tunylphenol)
? 2.2”-isobutylidene bis(4゜6-dimethylphenol); 2,2”-methylenebis(4-methyl-6
-cyclohexylphenol)2,6-ditertiary-
Butyl-4-methylphenol; 2,6-ditertiary-butyl-4-ethylphenol; 2,4-dimethyl-
6-tert-butylphenol; 2,6-ditertiary-α-dimethylamino-p-cresol; 2,6-
Ditert-butyl-4 (N,N”-dimethylaminomethylphenol); 4,4'-thiobis(2-methyl-6-tert-butylphenol);4°4'-thiobis(3-methyl-6-tert-butylphenol);butylphenol);2,2”-thiobis(4-methyl-6-tert-butylphenol); bis(3-methyl-4-hydroxy-5-tert-butylbenzyl) sulfide; bis(3,5-ditertiary-butyl- Examples include 4-hydroxybenzyl) sulfide.

The amount of the phenolic antioxidant (B) in the second invention varies depending on the properties of the above-mentioned lubricant base oil that is the component (A), the type of the phenolic antioxidant itself, etc.
Although not uniquely defined; usually (A) base oil 100
(B) phenolic antioxidant is added in an amount of 0.0% based on the weight part.
05-2. (Ratio of l placement part, preferably 0.1 to 1.0
Percentage of parts by weight.

Next, in the third invention, an organic molybdenum compound (C) is added to this lubricating base oil (A) to obtain a lubricating oil composition.

Here, various organic molybdenum compounds can be used as the organic molybdenum compound (C), and there are no particular limitations.

Specifically, Mo, which has been conventionally used as an extreme pressure agent,
-dithiocarbamate (MoDTC) and M.

-dithiophosphate (MoDTP) and the like.

The amount of the organic molybdenum compound (C) in the third invention varies depending on the properties of the above-mentioned lubricating base oil that is the component (A), the type of the organic molybdenum compound itself, etc., and cannot be unambiguously determined. Usually, (A) 100 parts of base oil is mixed with 0.05 to 2 parts of (C) organic molybdenum compound.
．． The proportion is 0 parts by weight, preferably 0.1 to 1.0 parts by weight.

Furthermore, in the fourth invention, the above (B) is added to this lubricating base oil (A).
) A phenolic antioxidant and (C) an organic molybdenum compound are both added to form a lubricating oil composition, and this composition exhibits particularly excellent stability against NOx gas. Here, the blending amounts of (B) phenolic antioxidant and (C) organic molybdenum compound are both (A) base oil 100%
The ratio may be 0.05 to 2.0 parts by weight, preferably 0.1 to 1.0 parts by weight, based on the weight part.

In the first invention, it is also effective to add appropriate amounts of various additives such as Zn-DTP, detergent-dispersing agents, polymers, etc. to (A) the lubricating base oil, if desired. Moreover, these various additives can also be added to the lubricating oil compositions of the second to fourth inventions.

〔Example〕 Next, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 5 and Comparative Examples 1 to 4 Sample oils were prepared by adding various additives to the base oils shown in Table 1, and NOx deterioration tests on the sample oils were conducted in the following manner. That is, 50 ml of the above sample oil was mixed with iron and copper catalysts (oxidation test JI
Nitric oxide (NO) gas with a concentration of 1% was blown at a rate of 61/hr and humidified air was blown at a rate of 101/hr in the presence of a test piece of SK-2514. The temperature of the sample oil was maintained at 135'C, and the time at which abnormal deterioration (sudden increase in acid value) began was measured.

*1 Phenolic antioxidant (4,4'-methylenebis(2,6-di-tertiary-butylphenol)) *22 Contains n-DTP, metal detergent, ashless dispersant, polymer, etc. *3 Solvent-refined oil (% CA 8): Distillate oil from intermediate base crude oil subjected to solvent extraction treatment and hydrogenation treatment *4 Solvent refined oil (%CA 4): Distillate oil from intermediate base crude oil subjected to solvent extraction treatment and hydrogenation treatment Treated *5 Two-stage hydrogenated oil (% CA O, 2 or less): Distillate oil from intermediate base crude oil subjected to two-stage hydrogenation treatment, -1+j++ [Effects of the Invention] As described above, the lubrication of the present invention The oil base oil or lubricating oil composition is stable against NO8 gas, and therefore is effectively used as a lubricating oil for internal combustion engines with a high concentration of NOx gas.

Procedural amendment (voluntary) April 10, 1986

Claims (7)

[Claims] (1) The viscosity at 100°C is 2 to 50 cSt,
A lubricating base oil for internal combustion engines, characterized in that the aromatic content is 2% or less. (2) (A) A base oil having a viscosity at 100°C of 2 to 50 cSt and an aromatic content of 2% or less;
B) Lubricating oil composition for internal combustion engines, characterized by containing a phenolic antioxidant (3) The internal combustion according to claim 2, which contains (B) a phenolic antioxidant in a ratio of 0.05 to 2.0 parts by weight based on 100 parts by weight of (A) the base oil. Engine lubricating oil composition (4) (A) A base oil having a viscosity at 100°C of 2 to 50 cSt and an aromatic content of 2% or less;
C) A lubricating oil composition for internal combustion engines containing an organic molybdenum compound (5) For an internal combustion engine according to claim 4, the organic molybdenum compound (C) is contained in a ratio of 0.05 to 2.0 parts by weight based on 100 parts by weight of (A) base oil. lubricating oil composition (6) (A) A base oil having a viscosity of 2 to 50 cSt at 100°C and an aromatic content of 2% or less, (B) a phenolic antioxidant, and (C) an organic molybdenum compound. Characteristic lubricating oil composition for internal combustion engines (7) 0.05 to 2.0 parts by weight of (B) phenolic antioxidant and (C
) A lubricating oil composition for an internal combustion engine according to claim 6, which contains an organic molybdenum compound in a proportion of 0.005 to 2.0 parts by weight.