JPH0257597B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a lubricating oil composition containing a rust-inhibiting additive composition, and more particularly, an alkenyl succinic acid half ester and a bis-(alkenyl succinic acid).
The present invention relates to a lubricating oil composition containing a specific proportion of a rust-inhibiting additive composition blended with an ester in a specific proportion. Various anti-rust additives are generally added to so-called lubricating oils such as turbine oil, engine oil, gear oil, hydraulic oil, compressor oil, metal working oil or bearing oil to impart anti-rust properties. has been done. The main properties required of these anti-rust additives are adsorption to metals and solubility to oil. Furthermore, when these anti-rust additives are added to mineral oils and/or synthetic oils and used as lubricating oil compositions, these compositions must have excellent anti-rust properties. Traditionally, carboxylic acids,
its salts or esters, sulfonates, amines,
and phosphoric acid, its salts or esters are well known, and carboxylic acids, particularly alkenylsuccinic acids and their esters, are mainly used as lubricating oils because of their excellent rust-preventing properties. At present, various alkenylsuccinic acid-based rust-preventing additives are commercially available from various additive manufacturers. However, although these commercially available alkenylsuccinic acid-based rust-preventing additives have rust-preventing properties, their rust-preventing properties are still insufficient, and their demulsifying properties and It had the disadvantage of decreasing oxidation stability. Therefore, the present inventors conducted repeated research to overcome the drawbacks of the conventionally known alkenyl succinic acid-based rust preventive additives, and as a result, developed an alkenyl succinic acid half ester and a bis-alkenyl succinic acid half ester having a limited structure. (alkenylsuccinic acid) ester in a specific proportion has extremely excellent performance as a rust-preventing additive, and has completed the present invention. An object of the present invention is to provide a lubricating oil composition containing a rust-preventing additive composition that exhibits particularly excellent rust-preventing performance without reducing demulsibility or oxidative stability. That is, the present invention provides [] for mineral oils and/or synthetic oils having a kinematic viscosity of 10 to 10,000 cSt (40°C) and a viscosity index of 80 or more, [] general formula and/or For 100 parts by weight of alkenylsuccinic acid half ester represented by the general formula An additive composition for rust prevention containing 5 to 40 parts by weight of bis-(alkenylsuccinic acid) ester represented by
The present invention provides a lubricating oil composition characterized in that it contains 1.0% by weight. In addition, in the above formula
R ₁ and R ₃ may be the same or different, and each represents an alkenyl group having 8 to 20 carbon atoms. Further, R ₂ and R ₄ may be the same type, and each represents a hydrogen atom or an alkyl group having 1 to 7 carbon atoms, an alkenyl group, a phenyl group, and a tolyl group. Hereinafter, the lubricating oil composition containing the rust-inhibiting additive composition according to the present invention will be explained in more detail. The alkenyl succinic acid half ester as used in the present invention has the general formula: and/or It is a compound represented by the general formula, and bis-(alkenylsuccinic acid) ester is a compound represented by the general formula, This is a compound represented by In the above formula, R ₁ and R ₃ each have 8 to 8 carbon atoms.
20, preferably an alkenyl group having 9 to 18 carbon atoms. This alkenyl group may be linear or branched, and its double bond may be located anywhere. In a branched alkenyl group, a double bond may be present in the main chain, or a so-called vinylidene type double bond may be present in the branch. Preferred alkenyl groups include, for example, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl,
Examples include heptadecenyl and octadecenyl groups. Further, more preferred as this alkenyl group are alkenyl groups having 9 to 18 carbon atoms derived from propylene and butene oligomers, and specific examples of such alkenyl groups include tripropenyl groups (nonenyl groups). , a tetrapropenyl group, a tributenyl group (dodecenyl group), a pentapropenyl group (pentadecenyl group), a tetrabutenyl group (hexadecenyl group), and a hexapropenyl group (octadecenyl group). In the present invention, the alkenyl groups of R ₁ and R ₃ may be the same or different. Furthermore, in the above formula, R ₂ and R ₄ each represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 7 carbon atoms. The monovalent hydrocarbon group having 1 to 7 carbon atoms specifically refers to an alkyl group, alkenyl group, phenyl group, and tolyl group having 1 to 7 carbon atoms. Among these, preferred as R ₂ and R ₄ are a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, a phenyl group, and a tolyl group. Specific examples of the alkyl group having 1 to 7 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group and heptyl group.
Furthermore, more preferred as R ₂ and R ₄ are:
These are a hydrogen atom, a methyl group, an ethyl group, and a phenyl group. In the present invention, R ₂ and R ₄ may be the same or different. As the alkenylsuccinic acid half ester and bis-(alkenylsuccinic acid) ester in the present invention, a single compound may be used, but the groups defined above as R ₁ , R ₂ , R ₃ and R ₄ It is also possible to use mixtures of compounds as long as they have the following. Rust preventive additive composition of the present invention ([]component)
consists of an alkenylsuccinic acid half ester and a bis-(alkenylsuccinic acid) ester as defined above. The amount of the component in the additive composition is 5 to 40 parts by weight per 100 parts by weight of the component.
parts by weight, preferably 7 to 30 parts by weight. If the amount of the component exceeds 40 parts by weight based on 100 parts by weight of the component, it is not preferable because the rust-preventing performance deteriorates and the demulsibility and oxidation stability also decrease. On the other hand, if the amount of the component is less than 5 parts by weight per 100 parts by weight of the component, the corrosivity to non-ferrous metals, especially bearing alloys using lead, etc. increases, which is undesirable. Rust preventive additive composition of the present invention ([]component)
may be used as it is, or may be diluted with mineral oil and/or synthetic oil as necessary to facilitate handling, and used in the form of a concentrated additive composition solution. Mineral oil and/or
Alternatively, the synthetic oil can be of the same type as the mineral oil and/or synthetic oil that are the components [] described below, and any viscosity can be used, but it usually has a kinematic viscosity of 30 to 150 cSt (at 40°C). Preferably. In addition, the amount of mineral oil and/or synthetic oil for diluting the additive composition is also arbitrary, but generally when used diluted,
Diluting with 10 to 50% by weight of mineral oil and/or synthetic oil is most preferred from the viewpoint of ease of handling. The mineral oil and/or synthetic oil that is the component [] of the present invention has a kinematic viscosity of 10 to 10,000 cSt (40°C), preferably 20 to 1,000 cSt (40°C), a viscosity index of 80 or more,
Preferably, 90 or more are used. Mineral oils here include petroleum lubricating oil fractions refined by hydrorefining, clay refining, solvent refining, or a combination of these, and nuclear hydrides of highly aromatic fractions obtained by cracking petroleum. can give. In addition, synthetic oils include alkylated aromatic compounds such as alkylbenzenes substituted with linear and branched alkyl groups, alkylnaphthalenes, and poly-α-
Examples include olefin oil, ester oil, and polyglycol oil. More specifically, for example, n-
Approximately C ₉ to _{C 40} monoalkylbenzenes and dialkylbenzenes obtained from olefin and benzene, approximately C ₉ to _{C 40} alkylbenzenes obtained by alkylation of benzene with oligomers of propylene, α-olefins having 4 to 14 carbon atoms alone Poly-α-olefin oils obtained by polymerization or copolymerization, diester oils of dibasic acids and monohydric alcohols such as di-α-ethylhexyl sebacate, and polyhydric alcohols such as trimethylolpropane tricaprylate. Ester oil, polyalkylene glycol or its monoalkyl ether
Examples include dialkyl ethers, dialkyl ethers, and mixtures thereof. The lubricating oil composition of the present invention contains the above-mentioned [] mineral oil and/or synthetic oil as an essential component, and the above-mentioned [] rust-inhibiting additive composition is 0.01 to 1.0% by weight based on the total amount of the lubricating oil composition. %, preferably 0.03 to 0.50%.
[]If the content of the component is less than 0.01% by weight, the rust prevention performance will be insufficient, and if the content of the component is less than 0.01% by weight,
If the amount exceeds 20%, it will not be possible to obtain a rust-preventing performance commensurate with the amount of the rust-preventing additive composition used, and this will be economically disadvantageous. In addition, other commonly used lubricant additives such as antioxidants, detergent dispersants, pour point depressants, etc. may be added to the lubricant composition of the present invention as necessary.
Viscosity index improvers, oil agents, anti-wear agents, extreme pressure agents, corrosion inhibitors, metal deactivators, antifoaming agents, emulsifiers, demulsifiers, bactericidal agents, coloring agents, etc. can also be added. Details of these various additives are disclosed in, for example, Journal of the Japan Society of Lubrication, Vol. 15, No. 6, or "Petroleum Product Additives" edited by Toshio Sakurai (Saiwai Shobo). The lubricating oil composition of the present invention is suitable for lubricating oils that require anti-corrosion performance, such as automobile engine oils, agricultural engine oils, diesel engine oils, marine diesel engine oils, industrial multi-purpose lubricating oils, turbine oils, and hydraulic oils. , spindle oil, oil film bearing oil,
Can be used for refrigeration oil, gear oil, automatic transmission oil, cylinder oil, dynamo oil, machine oil, cutting oil, metal processing oil, etc. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples unless the gist thereof is changed. Examples and Comparative Examples (A) Synthesis of tetrapropenyl succinic acid ester mixture 1.0 mol of propylene glycol was added to 1.0 mol of tetrapropenyl succinic anhydride,
A tetrapropenyl succinate mixture was obtained by heating and stirring at a reaction temperature of 100° C. for 5 hours. This mixture was fractionated by gel permeation chromatography (GPC) and identified using a mass spectrometer. This mixture was found to contain propylene glycol tetrapropenyl succinate half ester and propylene glycol bis(tetrapropenyl succinate) ester. It was a mixture of main components, and the weight ratio was half ester:bisester=about 2:3. (B) Production of additive composition for rust prevention When the above tetrapropenyl succinate mixture was subjected to GPC under the following operating conditions,
It was found that bisesters flowed out after a retention time of about 23 minutes, and half esters flowed out after about 26 minutes.
Therefore, during separation distillation by GPC, the bisester fraction was appropriately cut, the solvent was removed from the obtained fraction, and the rust preventive additive composition (Examples 1 and 2) according to the present invention was prepared. Obtained. For comparison, products containing only a half ester component (Comparative Example 1) and products containing a large amount of bisester components (Comparative Examples 2 and 3) were also produced using the same method. Further, as Comparative Example 4, the tetrapropenyl succinate mixture itself obtained in (A) was used. In addition, the weight ratio of half ester and bis ester of the rust preventive additive compositions of Examples 1 and 2 and Comparative Examples 1 to 4 was determined by GPC.
The results are shown in Table 1. GPC operating conditions Column: 7.5 mmi.d. The compositions of Examples 1 and 2 and Comparative Examples 1 to 4 were added to refined mineral oil with a viscosity of 32 cSt (40°C) and a viscosity index of 100 in the amounts shown in Table 1, and 2,6-dimethylsiloxane was added as an antioxidant. -t-butyl-p-
A lubricating oil composition was obtained by adding 0.6% by weight of each cresol. These lubricating oil compositions were subjected to various tests shown below to evaluate their performance. The results are also listed in Table 1. 1 Rust prevention performance test Compliant with JIS-K-2510 "Lubricating oil rust prevention performance test". Test time: 24 hours Artificial seawater used 2 Demulsification test Compliant with JIS-K-2520.3.2 "Lubricating oil demulsification test". 3 Oxidation stability performance test Conforms to JIS-K-2514.3.3 "Turbine oil oxidation stability test". The time required to reach a certain total acid value is stated. 4 Corrosion resistance performance test Conforms to JIS-K-2246.4.26 "Rust preventive oil corrosion test". Test piece: Lead plate (JIS-H-4301) Note that the oxidation stability performance test in 3 and the corrosion resistance performance test in 4 were performed on lubricating oil compositions containing 0.05% by weight of the rust preventive additive composition of the present invention. I only followed things.

[Table] As is clear from Table 1, the lubricating oil composition containing the rust-inhibiting additive composition of the present invention has good rust-inhibiting performance, demulsibility, and oxidation stability.
It also has the excellent performance of being less corrosive to non-ferrous metals such as lead. On the other hand, the lubricating oil composition of Comparative Example 1, which does not contain bisester, has good rust prevention performance, demulsibility, and oxidation stability, but is extremely corrosive to lead. On the other hand, the lubricating oil compositions of Comparative Examples 2 to 4, which contain a large amount of bisester, have low corrosiveness against lead, but have poor rust prevention performance, demulsibility, and oxidation stability, and are therefore not desirable.

Claims (1)

[Claims] 1 [] Kinematic viscosity 10 to 10000 cSt (40°C), viscosity index
For mineral and/or synthetic oils with a 80 or higher [] general formula and/or For 100 parts by weight of alkenylsuccinic acid half ester represented by the general formula (In the formula, R ₁ and R ₃ may be the same or different, and each represents an alkenyl group having 8 to 20 carbon atoms. In addition, R ₂ and R ₄ may be the same or different, and each is a hydrogen atom or 1 carbon atom.
-7 alkyl groups, alkenyl groups, phenyl groups and tolyl groups. ) A rust-preventing additive composition containing 5 to 40 parts by weight of bis(alkenylsuccinic acid) ester represented by
A lubricating oil composition characterized by containing 1.0% by weight.