JP6082710B2 - Lubricating oil composition - Google Patents

Description

  The present invention relates to a lubricating oil composition.

  Lubricating oils are prepared by blending additives with base oils such as mineral oils and synthetic oils according to required properties. For example, the following Patent Documents 1 to 3 disclose a lubricating oil in which a sarcosine acid derivative and an extreme pressure agent are blended with a base oil as a lubricating oil excellent in rust prevention characteristics and wear resistance.

JP 2002-129180 A JP 2009-144045 A JP 2012-007186 A

  By the way, generally, in order to obtain a desired effect by adding an additive, it is necessary to add an effective amount of the additive to the base oil.

  However, studies by the present inventors have revealed that precipitation can occur when an effective amount of a sarcosine acid derivative is added to a base oil. In particular, precipitation may occur during use of the lubricating oil, even if precipitation does not occur during the preparation of the lubricating oil.

  The present invention has been made in view of the above problems, and provides a lubricating oil composition capable of effectively obtaining the effect of adding a sarcosine acid derivative and sufficiently suppressing the occurrence of precipitation. The purpose is to do.

  The present invention comprises a hydrocarbon base oil, a sarcosine acid derivative, and an acidic phosphate ester amine salt, and the content of the sarcosine acid derivative is 0.005 to 0.1 based on the total amount of the lubricating oil composition. The content of the acidic phosphate amine salt is 0.01 to 0.5 mass%, the content of the sarcosine acid derivative (A) and the content of the acidic phosphate amine salt (B) A lubricating oil composition having a mass ratio (B / A) of 1 to 30 is provided.

  In the lubricating oil composition according to the present invention, the content of the sarcosine acid derivative and the acidic phosphate ester amine salt, and further the ratio between the content of the sarcosine acid derivative and the content of the acidic phosphate ester salt is within a predetermined range. By making it inside, the effect of adding a sarcosine acid derivative can be effectively obtained, and the occurrence of precipitation can be sufficiently suppressed. On the other hand, in a lubricating oil composition not having this configuration, for example, a lubricating oil composition containing a hydrocarbon base oil, 0.01 to 0.5% by mass of an acidic phosphate amine salt is not contained, or sarcosine When the ratio (B / A) of the content (A) of the acid derivative and the content (B) of the acidic phosphate ester salt is outside the range of 1 to 30 in terms of mass ratio, the use thereof The inventors have confirmed that precipitation can occur. From these facts, one of the reasons why the above-described effect is achieved by the present invention is that the content of the sarcosine acid derivative and the acidic phosphate ester amine salt in the combination with the hydrocarbon base oil, and the content of both It is inferred that the acid phosphate amine amine salt functions as a dissolution aid for the sarcosine acid derivative by satisfying the above-described ratio.

It is preferred that the% C _P of the hydrocarbon-based base oil is 50 or more, it is preferable that the content of the hydrocarbon-based base oil is at least 95 mass% in the total amount of the lubricating oil composition reference.

［式中、Ｒ^１は炭素数１０〜２０の直鎖アルケニル基を示す。］ The sarcosine acid derivative preferably contains a compound represented by the following general formula (1).

[Wherein, R ¹ represents a linear alkenyl group having 10 to 20 carbon atoms. ]

  ADVANTAGE OF THE INVENTION According to this invention, the lubricating oil composition which can acquire effectively the addition effect of a sarcosine acid derivative and can fully suppress generation | occurrence | production of precipitation can be provided.

  Hereinafter, preferred embodiments of the lubricating oil composition according to the present invention will be described in detail.

  The lubricating oil composition according to the present embodiment contains a hydrocarbon base oil, a sarcosine acid derivative, and an acidic phosphate amine salt. On the basis of the total amount of the lubricating oil composition, the content of the sarcosine acid derivative is 0.005 to 0.1% by mass, and the content of the acidic phosphate amine salt is 0.01 to 0.5% by mass. The ratio (B / A) between the content (A) of the sarcosine acid derivative and the content (B) of the acidic phosphate ester salt is 1 to 30 in terms of mass ratio.

  Examples of the hydrocarbon base oil include a mineral base oil, a synthetic base oil, or a mixed oil of two or more of these.

  Mineral oil base oils include, for example, kerosene fractions obtained by distillation of paraffinic or naphthenic crude oils; normal paraffins obtained by extraction operations from kerosene fractions; and obtained by distillation of paraffinic or naphthenic crude oils. The raw material is a synthetic oil such as Fischer-Tropsch wax, GTL wax, etc. obtained by a lubricating oil fraction obtained, or a wax such as slack wax obtained by a lubricating oil dewaxing process and / or a gas-to-liquid (GTL) process, etc. Paraffin purified by one or more appropriate combinations of solvent removal, solvent extraction, hydrocracking, hydroisomerization, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, clay treatment, etc. Mineral oil, naphthenic mineral oil, normal paraffin base oil, isoparaffin base oil . Among these, paraffinic mineral oil, normal paraffinic base oil and isoparaffinic base oil are preferably used.

  Synthetic base oils include, for example, poly α-olefins or hydrides thereof; olefin oligomers such as propylene oligomers, isobutylene oligomers, polybutenes, 1-octene oligomers, 1-decene oligomers, ethylene-propylene oligomers or hydrides thereof; alkylbenzenes An alkylnaphthalene. Among these, poly α-olefin or a hydride thereof is preferably used.

The% C _p of the hydrocarbon base oil is preferably 50 or more, more preferably 75 or more, and still more preferably 90 or more. % C _N of hydrocarbon-based base oil is preferably 40 or less, more preferably 22 or less, more preferably 16 or less. The% C _A of the hydrocarbon base oil is preferably 10 or less, more preferably 5 or less, and still more preferably 0.5 or less. % C P of the hydrocarbon-based base _oil,% when C _N and% C _A is within the above range, the stability is high against such oxidation of hydrocarbon-based base oil, even when exposed like under heating conditions Deterioration of quality is easily suppressed.

_{Incidentally,%} C P of the present invention, the% _{C N} and% _{C A} means a value determined by a method in accordance with ASTM D3238-85 (2010), respectively (n-d-M ring analysis).

The kinematic viscosity at 40 ° C. of the hydrocarbon base oil is preferably ² to 1000 mm ² / s, more preferably 5 to 680 mm ² / s, and still more preferably 32 to 680 mm ² / s. The kinematic viscosity at 100 ° C. of the hydrocarbon base oil is preferably ² to 50 mm ² / s, more preferably 3 to 45 mm ² / s, and still more preferably 5 to 40 mm ² / s. If the kinematic viscosity of the hydrocarbon base oil is within the above range, the appropriate viscosity of the hydrocarbon base oil can be secured, and a good oil film can be obtained in the actual operating temperature range, so the machine can be effectively protected. .

  The viscosity index of the hydrocarbon base oil is preferably 70 or more, more preferably 120 or more, and still more preferably 135 or more. When the viscosity index is within the above range, the stability of the viscosity with respect to the external temperature is secured, so that the oil film can be stably formed even with respect to the external temperature change during use.

  The kinematic viscosity and viscosity index at 40 ° C. and 100 ° C. in the present invention mean values measured in accordance with JIS K2283: 2000 “Crude oil and petroleum products—Kinematic viscosity test method and viscosity index calculation method”, respectively.

  The content of the hydrocarbon base oil is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 98% by mass or more based on the total amount of the lubricating oil composition.

  Although it does not restrict | limit especially as a sarcosine acid derivative, For example, the compound represented by following General formula (1) is used.

In the general formula (1), R ¹ represents an aryl group, alkyl group or alkenyl group having 6 to 24 carbon atoms, preferably a linear alkenyl group having 10 to 20 carbon atoms.

  The content of the sarcosine acid derivative is 0.005% by mass or more, preferably 0.01% by mass or more, more preferably 0.02% by mass or more, based on the total amount of the lubricating oil composition, from the viewpoint of rust prevention ability. It is. The content of the sarcosine acid derivative is 0.1% by mass or less, preferably 0.08, based on the total amount of the lubricating oil composition, from the viewpoint of suppressing the occurrence of precipitation accompanying deterioration during use of the lubricating oil composition. It is not more than mass%, more preferably not more than 0.05 mass%.

  Although it does not restrict | limit especially as acidic phosphate ester amine salt, For example, the salt of the acidic phosphate ester represented by following General formula (2) and the amine represented by following General formula (3) is used.

In general formula (2), each R ² independently represents an aryl group, alkyl group or alkenyl group having 6 to 24 carbon atoms, preferably an alkyl group or alkenyl group having 6 to 18 carbon atoms, more preferably. Represents a straight-chain alkyl group having 6 to 12 carbon atoms. m represents 1 or 2. The acidic phosphate ester represented by the general formula (2) is a mixture of an acidic phosphate ester in which m is 1 in the general formula (2) and an acidic phosphate ester in which m is 2 in the general formula (2). It is preferable that

In general formula (3), each R ³ independently represents an aryl group, alkyl group or alkenyl group having 6 to 24 carbon atoms, preferably a linear or branched alkyl group or alkenyl group having 6 to 18 carbon atoms. More preferably, it represents a linear alkyl group having 12 to 18 carbon atoms. n represents an integer of 0 to 3, preferably 2.

  The content of the acidic phosphoric acid ester amine salt is 0.01% by mass or more, preferably 0.02% by mass or more, more preferably, based on the total amount of the lubricating oil composition, from the viewpoint of imparting rust prevention and extreme pressure. Is 0.05 mass% or more. The content of the acidic phosphoric acid ester amine salt is 0.5% by mass or less based on the total amount of the lubricating oil composition from the viewpoint of suppressing the occurrence of precipitation associated with deterioration during use of the lubricating oil composition, preferably It is 0.4 mass% or less, More preferably, it is 0.3 mass% or less.

  The ratio (B / A) of the content (A) of the sarcosine acid derivative and the content (B) of the acidic phosphoric acid ester amine salt is a viewpoint that suppresses the occurrence of precipitation accompanying deterioration during use of the lubricating oil composition. From a mass ratio, it is 1-30, Preferably it is 2-25, More preferably, it is 3-20, More preferably, it is 4-10.

  The lubricating oil composition according to this embodiment may further contain other base oils and other additives in addition to the hydrocarbon base oil, the sarcosine acid derivative and the acidic phosphate ester amine salt.

  Examples of other base oils include esters, polyalkylene glycols, polyvinyl ethers, ketones, silicones, and perfluoroethers. Examples of other additives include phenol-based or amine-based antioxidants, extreme pressure agents, metal deactivators, antifoaming agents, corrosion inhibitors, wetting agents, film-forming agents, and surfactants. The content of other base oils and other additives is not particularly limited, but is preferably 10% by mass or less based on the total amount of the lubricating oil composition, for example.

  Among other additives, phenol-based or amine-based antioxidants and extreme pressure agents are preferably used. The phenol-based or amine-based antioxidant is not particularly limited, and examples thereof include 2,6-di-t-butyl-p-cresol, 4,4′-methylenebis (2,6-di-t-butylphenol), phenyl. Naphthylamine, diphenylamine and the like are used. Although it does not restrict | limit especially as an extreme pressure agent, For example, a triphenyl phosphorothionate etc. are used.

  The lubricating oil composition according to the present embodiment is suitably used as, for example, machine tool lubricating oil, engine oil, drive system lubricating oil, grease, wet brake oil, hydraulic hydraulic oil, turbine oil, compressor oil, and the like.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to an Example.

  Lubricating oil compositions having the compositions shown in Tables 1 to 4 were prepared using the base oils and additives shown below. In the table, B / A represents the ratio (mass ratio) between the content (A) of the sarcosine acid derivative and the content (B) of the acidic phosphate amine salt.

(Base oil)
Base oil 1: poly α-olefin (decene, dodecene derivative, 40 ° C. kinematic viscosity: 44.1 mm ² / s, 100 ° C. kinematic viscosity: 7.8 mm ² / s, viscosity index: 146,% C _p : 100)
Base oil 2: mineral oil (40 ° C. kinematic viscosity: 47.7 mm ² / s, 100 ° C. kinematic viscosity: 7.8 mm ² / s, viscosity index: 131,% C _p : 79.7,% C _N : 20.3 ,% C _A : 0.0)
Base oil 3: mineral oil (40 ° C. kinematic viscosity: 47.4 mm ² / s, 100 ° C. kinematic viscosity: 6.9 mm ² / s, viscosity index: 101,% C _p : 67.5,% C _N : 25.7 ,% C _A : 6.8)

(Additive)
Additive A1: N-oleoyl sarcosine additive B1: Acid phosphate ester amine salt (R ² in the general formula (2) is a linear alkyl group having 6 carbon atoms, m is a mixture of 1 and 2, R ³ in the general formula (3) is a linear or branched alkyl group having 10 to 14 carbon atoms, and n is 1 or 2.
Additive B2: Acid phosphate ester amine salt (R ² in the general formula (2) is a linear alkenyl group having 18 carbon atoms, m is a mixture of 1 and 2, and R ³ in the general formula (3) is carbon. A straight-chain alkyl group of formula 18, a compound wherein n is 2)
Additive b1: 2-ethylhexyl phosphate additive b2: tricresyl phosphate additive C1: Other additives (amine antioxidant, metal deactivator, antifoaming agent)

  Each lubricating oil composition was subjected to the following rust prevention evaluation test, extreme pressure performance evaluation test, and precipitation evaluation test. The results are shown in Tables 1-4.

(Rust prevention evaluation test)
In accordance with JIS K2510: 1998 "Lubricating oil-rust prevention performance test method", the presence or absence of rust was judged.

(Extreme pressure performance evaluation test)
Extreme pressure performance was evaluated in accordance with the Timken method described in JIS K2519 “Lubricating oil—load bearing capacity test method”. It can be said that the OK load is 5.44 kgf or more.

(Precipitation evaluation test)
In a 50 ml beaker, 45 g of sample oil and the iron and copper catalyst of the wire mold were put and placed in a constant temperature bath at 120 ° C. for 3 days. Thereafter, the appearance was observed to confirm the presence or absence of precipitation.

Claims (3)

A hydrocarbon base oil, a sarcosine acid derivative, and an acidic phosphate ester amine salt,
Based on the total amount of the lubricating oil composition, the content of the sarcosine acid derivative is 0.005 to 0.08 % by mass, and the content of the acidic phosphate amine salt is 0.01 to 0.4 % by mass. ,
Lubricating oil composition whose ratio (B / A) of content (A) of the said sarcosine acid derivative and content (B) of the said acidic phosphate amine salt is 1-30 by mass ratio. The% C _P of the hydrocarbon-based base oil is 50 or more, the content of the hydrocarbon-based base oil is at least 95 mass% of the lubricating oil composition the total amount, the lubricating oil composition according to claim 1 . The lubricating oil composition according to claim 1 or 2, wherein the sarcosine acid derivative contains a compound represented by the following general formula (1).

[Wherein, R ¹ represents a linear alkenyl group having 10 to 20 carbon atoms. ]