JP5344833B2 - Lubricating oil additive composition - Google Patents

Description

  The present invention relates to an additive composition for lubricating oil containing a metal salt of a phosphorus-containing compound.

Metal salts of phosphorus-containing compounds such as thiophosphates or phosphates that are solid at room temperature are poor in handling during production and transportation, or cannot be dissolved in room temperature base oil in a short time, after being dissolved Therefore, a technique of dissolving in an amine compound or the like and liquefying it has been proposed (see Patent Document 1). However, when a metal salt of a phosphorus-containing compound dissolved in these compounds is added to the lubricating oil, there is a possibility of adverse effects such as swelling of the rubber seal, and thus there is a great limitation in use.
International Publication No. 2004/003118 Pamphlet

The present invention has no adverse effects, such as swelling the rubber seal, yet provide a storage excellent in stability, lubricating oil additive composition containing a metal salt of a phosphorus-containing compounds of the solid-phosphate ester such as at room temperature In addition, the present invention provides a method for producing an additive composition for lubricating oil in which the above compound is dissolved in a base oil in a short time at a relatively low temperature of 60 ° C. or lower.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have made it possible to shorten the metal salt of the phosphorus-containing compound at a high concentration and at a relatively low temperature of 60 ° C. or less by using a specific lubricating base oil. It has been found that it can be dissolved in time and the storage stability after dissolution is good, and the present invention has been completed.

（一般式（１）において、Ｘ^４、Ｘ^５、Ｘ^６及びＸ^７は、それぞれ酸素原子を示し、Ｒ^１、Ｒ^２及びＲ^３は、それぞれ個別に水素または炭素数３〜１８の炭化水素基を示し、Ｒ^１、Ｒ^２及びＲ^３のうちの少なくとも１個は水素ではない。） That is, the present invention provides lubrication kinematic viscosity of 100 ° C. consists 0.5~3mm ² / s,% _{C A} of 3 or less, and poly -α- olefin sulfur content is not more than 0.05 wt% The oil base oil contains 10 to 90% by mass of a metal salt of a phosphorus-containing compound composed of a mixture of a monoester and a diester of phosphoric acid represented by the general formula (1) based on the total amount of the composition. The present invention relates to an additive composition for lubricating oil.

(In General Formula (1), X ⁴ , X ⁵ , X ⁶ and X ⁷ each represents an oxygen atom, and R ¹ , R ² and R ³ are each independently hydrogen or a hydrocarbon having 3 to 18 carbon atoms. And at least one of R ¹ , R ² and R ³ is not hydrogen.)

The present invention also relates to the above-described additive composition for lubricating oil, wherein the mixing ratio of the monoester and the diester is 80:20 to 20:80 by mass ratio.

（一般式（１）において、Ｘ^４、Ｘ^５、Ｘ^６及びＸ^７は、それぞれ酸素原子を示し、Ｒ^１、Ｒ^２及びＲ^３は、それぞれ個別に水素または炭素数３〜１８の炭化水素基を示し、Ｒ^１、Ｒ^２及びＲ^３のうちの少なくとも１個は水素ではない。） Further, the present invention is lubricating the kinematic viscosity of 100 ° C. consists 0.5~3mm ² / s,% _{C A} of 3 or less, and poly -α- olefin sulfur content is not more than 0.05 wt% Lubrication characterized by dissolving 10 to 90% by mass of a metal salt of a phosphorus-containing compound comprising a mixture of a monoester and a diester of phosphoric acid represented by the general formula (1) in an oil base oil based on the total amount of the composition. The present invention relates to a method for producing an additive composition for oil.

(In General Formula (1), X ⁴ , X ⁵ , X ⁶ and X ⁷ each represents an oxygen atom, and R ¹ , R ² and R ³ are each independently hydrogen or a hydrocarbon having 3 to 18 carbon atoms. And at least one of R ¹ , R ² and R ³ is not hydrogen.)

  The additive composition for lubricating oil of the present invention can be produced in a short time at a relatively low temperature of 60 ° C. or less, has no adverse effect such as swelling of a rubber seal, and is excellent in storage stability.

Hereinafter, the present invention will be described in detail.
The base oil employed in the lubricating oil additive composition of the present invention, a kinematic viscosity of 100 ° C. is 0.5~3mm ² / s,% _{C A} of 3 or less, and sulfur content of 0.05 wt% The following poly-α-olefins and mixtures thereof can be used.

The poly -α- olefin, 1 - octene oligomer, poly -α- olefin emissions or a mixture of two or more thereof, such as 1-decene oligomer can be exemplified.

Kinematic viscosity at 100 ° C. of the lubricating base oil used in the present invention is required to be 0.5 to 3 mm ² / s, preferably 0.7~2.9mm ² / s, more preferably 1.0 It is -2.8mm < ² > / s, Most preferably, it is 1.2-2.7mm < ² > / s. When the kinematic viscosity at 100 ° C. of the lubricating base oil is less than 0.5 mm ² / s, it is not preferable in terms of evaporation loss. Further, when the kinematic viscosity at 100 ° C. exceeds 3 mm ² / s, it is not preferable because the dissolving power for the phosphorus-containing compound is insufficient.

% C _A of the lubricating base oil used in the present invention it is necessary that is 3 or less, preferably 2.5 or less, more preferably 2.0 or less, more preferably 1.5 or less. When% C _A of the lubricating base oil exceeds 3, there is a tendency that dissolving power for the phosphorus-containing compound is undesirably reduced. Incidentally,% C _A of the lubricating base oil used in the present invention may be zero.
In the present invention,% C _A means the percentage of the total number of aromatic carbon atoms determined by a method (ndM ring analysis) based on ASTM D 3238-85.

The sulfur content of the lubricating base oil used in the present invention needs to be 0.05% by mass or less, preferably 0.04% by mass or less, more preferably 0.03% by mass or less, particularly preferably. It is 0.02 mass% or less. When the sulfur content of the lubricating base oil exceeds 0.05% by mass, the dissolving power for the phosphorus-containing compound may decrease, which is not preferable. Usually, the sulfur content of the lubricating base oil depends on the sulfur content of the raw material. For example, when a raw material that does not substantially contain sulfur such as a synthetic wax component obtained by a Fischer-Tropsch reaction or the like is used, a lubricating base oil that does not substantially contain sulfur can be obtained. In addition, when using a raw material containing sulfur such as slack wax obtained in the refining process of the lubricating base oil and microwax obtained in the refining process, the sulfur content in the obtained lubricating base oil is usually 0.01. It becomes mass% or more. In the present invention, the sulfur content needs to be 0.05% by mass or less.
In addition, the sulfur content as used in the field of this invention means the sulfur content measured based on JISK2541-1996.

  The viscosity index of the lubricating base oil used in the present invention is not particularly limited, but the value is preferably 80 or more, more preferably 100 or more, and most preferably 120 or more so that excellent viscosity characteristics from low temperature to high temperature can be obtained. preferable. The upper limit of the viscosity index is not particularly limited, and normal paraffin, slack wax, GTL wax, or the like, or those of about 135 to 180 such as isoparaffin mineral oil obtained by isomerizing these can also be used. When the viscosity index of the base oil is less than 80, the dissolving power for the phosphorus-containing compound may be deteriorated.

The additive composition for lubricating oil according to the present invention is a metal salt of a phosphorus-containing compound comprising a mixture of a monoester and a diester of phosphoric acid represented by the following general formula (1), in the specific lubricating base oil described above. hereinafter simply referred to as metal salts of phosphorus-containing compound.) which contained 10 to 90 wt% of the total amount of the composition.

In the general formula (1), X ⁴ , X ⁵ , X ⁶ and X ⁷ each represents an oxygen atom, and R ¹ , R ² and R ³ each independently represent hydrogen or a carbon number of 3 to 18, preferably Represents 4 to 16, more preferably 4 to 14, and most preferably 4 to 12 hydrocarbon groups . When the number of carbon atoms of the hydrocarbon group is less than 3, the solubility may be inferior, whereas when it exceeds 18, the production may be difficult. Note that at least one of R ¹ , R ² and R ³ is not hydrogen.

Examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, an alkylcycloalkyl group, an aryl group, an alkylaryl group, and an arylalkyl group, and an alkyl group is particularly preferable.
Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group. Group, hexadecyl group, heptadecyl group, octadecyl group (these alkyl groups may be linear or branched), and the like.

Specific examples of the general formula (1), mono-hydrocarbyl phosphate esters, dihydrocarbyl Lil phosphoric acid esters, Oh Rui can mixtures thereof. More specifically, dibutyl phosphate, mono-2-ethylhexyl phosphate, di-2-ethylhexyl phosphate, mono-2-ethylbutyl phosphate, di-2-ethylbutyl phosphate, etc. Or mixtures thereof.
In the present invention, a mixture of a monoester and a diester is preferable, and in particular, a mixture of mono-2-ethylhexyl phosphate and di-2-ethylhexyl phosphate, mono-2-ethylbutyl phosphate, A di-2-ethylbutyl phosphate ester mixture is preferred. Although there is no limitation in particular about the mixing ratio of a monoester and a diester, 80: 20-20: 80 is preferable by mass ratio, and 60: 40-40: 60 is more preferable.

  The additive composition for lubricating oil of the present invention contains a metal salt of a phosphorus-containing compound represented by the general formula (1). Specific examples of the metal include zinc, copper, nickel, cobalt, calcium, magnesium and the like, and zinc is most preferable.

  The mixing ratio of the metal salt of the phosphorus-containing compound with respect to the lubricating base oil is 10 to 90% by mass, preferably 30 to 85% by mass, more preferably 35 to 80% by mass, and most preferably 40 to 40% by mass. 75% by mass. When the mixing ratio is less than 10% by mass, the blending amount at the time of producing the lubricating oil increases, and there is a possibility that the evaporability of the lubricating oil may increase. When the mixing ratio is more than 90% by mass, the additive during storage May cause separation.

The kinematic viscosity at 100 ° C. of the additive composition for lubricating oil of the present invention is preferably 0.5 to ³ mm ² / s, more preferably 1.0 to ³ mm ² / s, still more preferably 1.5. -2.5 mm < ² > / s.

  The additive composition for lubricating oil of the present invention is, for example, a metal salt of a phosphorus-containing compound finely crushed in a lubricating base oil heated to 30 to 60 ° C., and stirred at a rotational speed of about 300 rpm. Or by dissolving a metal salt of a phosphorus-containing compound in an organic solvent such as hexane, and then mixing with a lubricating base oil and distilling off the solvent.

  The additive composition for lubricating oil of the present invention thus obtained is used as an additive for various lubricating oils.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

[Examples 1 to 4 and Comparative Examples 1 to 16]
Lubricating oil additive compositions having the compositions shown in Tables 1 and 2 were prepared by blending the following base oils with metal salts of phosphorus-containing compounds (Examples 1 to 4 and Comparative Examples 1 to 16).

(1) Base oil Base oil 2: Poly-α-olefin (PAO) (kinematic viscosity at 100 ° C .: 2.0 mm ² / s,% C _A : 0, sulfur content: 0.00% by mass)
Base oil 3: paraffinic solvent refined mineral oil (kinematic viscosity at 100 ° C .: 2.1 mm ² / s,% C _A : 5, sulfur content: 0.08 mass%)
Base oil 4: paraffinic solvent refined mineral oil (kinematic viscosity at 100 ° C .: 4.4 mm ² / s,% C _A : 5, sulfur content: 0.09 mass%)
Base oil 5: hydrocracked mineral oil (kinematic viscosity at 100 ° C .: 4.0 mm ² / s,% C _A : 0, sulfur content: 0.00% by mass)
Base oil 6: poly-α-olefin (kinematic viscosity at 100 ° C .: 4.0 mm ² / s,% C _A : 0, sulfur content: 0.00% by mass)

(2) Metal salt of phosphorus-containing compound A-1: Mono and di-2-ethylbutyl phosphate zinc salt mixture (phosphorus content: 11.6% by mass, zinc content: 16.2% by mass)
A-2: Mono and di-2-ethylhexyl phosphate ester zinc salt mixture (phosphorus content: 10.2% by mass, zinc content: 15% by mass)

The additive compositions for lubricating oils of Examples 1 to 4 and Comparative Examples 1 to 16 were subjected to a storage test at room temperature, and whether or not insoluble analysis was performed after 1 week, 2 weeks, 3 weeks, and 4 weeks. Was observed. The obtained results are shown in Tables 1 and 2.

Claims (3)

_A lubricating base oil composed of a poly-α-olefin having a kinematic viscosity at 100 ° C. of 0.5 to 3 mm ² / s,% CA of 3 or less, and a sulfur content of 0.05% by mass or less, Lubricating oil additive comprising 10 to 90% by mass of a metal salt of a phosphorus-containing compound comprising a mixture of a monoester and a diester of phosphoric acid represented by formula (1) based on the total amount of the composition Composition.

(In General Formula (1), X ⁴ , X ⁵ , X ⁶ and X ⁷ each represents an oxygen atom, and R ¹ , R ² and R ³ are each independently hydrogen or a hydrocarbon having 3 to 18 carbon atoms. And at least one of R ¹ , R ² and R ³ is not hydrogen.)   The additive composition for lubricating oil according to claim 1, wherein the mixing ratio of the monoester and the diester is 80:20 to 20:80 by mass ratio. _A lubricating base oil composed of a poly-α-olefin having a kinematic viscosity at 100 ° C. of 0.5 to 3 mm ² / s,% CA of 3 or less, and a sulfur content of 0.05% by mass or less, An additive composition for lubricating oil, wherein a metal salt of a phosphorus-containing compound comprising a mixture of a monoester and a diester of phosphoric acid represented by formula (1) is dissolved in an amount of 10 to 90% by mass based on the total amount of the composition. Manufacturing method.

(In General Formula (1), X ⁴ , X ⁵ , X ⁶ and X ⁷ each represents an oxygen atom, and R ¹ , R ² and R ³ are each independently hydrogen or a hydrocarbon having 3 to 18 carbon atoms. And at least one of R ¹ , R ² and R ³ is not hydrogen.)