JPWO2017187970A1 - Lubricant and lubrication method - Google Patents

Abstract

Provided is a lubricant that has excellent biodegradability and can reduce environmental impact. The lubricant of the present invention is represented by the following formula (1): wherein R 1 is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogen having 1 to 12 carbon atoms. And R2 is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a predetermined monovalent group. The compound represented by this is included as a base oil.

Description

  The present invention relates to a lubricant and a lubrication method. The present invention particularly relates to a lubricant that can be suitably used between a rotor and a housing of a liquid ring vacuum pump or between a stationary ring and a rotating ring of a mechanical seal, and a lubrication method using the lubricant. About.

  Lubricants are used in a wide range of objects such as industrial machines because they can reduce friction and wear between two sliding objects. And conventionally, as the lubricant, a lubricant containing mineral oil as the base oil has been frequently used.

  However, as the interest in global environmental problems has increased recently, lubricants are required to have a lower environmental load. Therefore, in recent years, various studies have been made on the composition of the lubricant.

  Specifically, for example, in Patent Document 1, for a base oil composed of poly α-olefin, at least one selected from a sarcosine acid derivative and an acidic phosphate amine salt, an amine-based antioxidant, A lubricating oil composition containing a benzotriazole-based compound is disclosed. And in patent document 1, the environmental load is reduced by reducing the quantity of the metal element, phosphorus element, sulfur element, and nitrogen element which are contained in the lubricating oil composition.

Japanese Patent Application Laid-Open No. 2015-189887

  However, the conventional lubricating oil composition described in Patent Document 1 has low biodegradability, and could not sufficiently reduce the load applied to the environment.

Then, an object of this invention is to provide the lubricant which has the outstanding biodegradability and can reduce environmental impact.
Another object of the present invention is to provide a lubrication method having a low environmental load.

  The present inventors have intensively studied for the purpose of solving the above problems. Then, the present inventors have found that a lubricant having excellent biodegradability can be obtained by using a predetermined compound as a base oil, and have completed the present invention.

〔式（１）中、Ｒ¹は、炭素数１以上１２以下のアルキル基、炭素数２以上１２以下のアルケニル基または炭素数１以上１２以下のハロゲン化アルキル基であり、Ｒ²は、水素原子、炭素数１以上８以下のアルキル基または下記式（２）〜（５）：

［式（２）〜（５）中、Ｒ³およびＲ⁴は、水素原子、炭素数１以上８以下のアルキル基または下記式（６）：

（式（６）中、Ｒ⁵は、炭素数１以上１２以下のアルキル基、炭素数２以上１２以下のアルケニル基または炭素数１以上１２以下のハロゲン化アルキル基である。）で表される一価の基であり、同一でも異なっていてもよく、「＊」は結合手であることを示す。］の何れかで表される一価の基である。〕で表される化合物を基油として含むことを特徴とする。基油として上記化合物を含む潤滑剤は、生分解性が高く、環境に与える負荷を低減することができる。That is, this invention aims to solve the above-mentioned problem advantageously, and the lubricant of the present invention has the following formula (1):

[In Formula (1), R ¹ is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogenated alkyl group having 1 to 12 carbon atoms, and R ² is hydrogen. An atom, an alkyl group having 1 to 8 carbon atoms, or the following formulas (2) to (5):

[In the formulas (2) to (5), R ³ and R ⁴ are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or the following formula (6):

(In formula (6), R ⁵ is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogenated alkyl group having 1 to 12 carbon atoms). It is a monovalent group, which may be the same or different, and “*” indicates a bond. ] Is a monovalent group represented by any one of It contains the compound represented by this as base oil. A lubricant containing the above compound as a base oil has high biodegradability and can reduce the load on the environment.

Here, in the lubricant of the present invention, the R ¹ is preferably an n-pentyl group or a 2-pentenyl group. This is because the compound in which R ¹ is the predetermined functional group is further excellent in biodegradability and safety.

In the lubricant of the present invention, R ² is preferably an alkyl group having 1 to 8 carbon atoms. This is because the compound in which R ² is the predetermined functional group is further excellent in biodegradability and safety.

  In the lubricant of the present invention, the compound is preferably methyl jasmonate or methyl dihydrojasmonate. This is because methyl jasmonate or methyl dihydrojasmonate is particularly excellent in biodegradability, as well as safety and fluidity.

  The lubricant of the present invention further contains an antioxidant, and the antioxidant is ascorbic acid, tocopherol, sodium erythorbate, propyl gallate, sodium sulfite, chlorogenic acid, catechin, rosemary extract, dibutyl It is preferably at least one selected from the group consisting of hydroxytoluene and butylhydroxyanisole. It is because it can suppress that the biodegradability of a lubricant falls if the component mentioned above is used as antioxidant.

  The lubricant of the present invention further contains a viscosity modifier, and the viscosity modifier is preferably at least one selected from the group consisting of polysaccharides, vegetable oils, animal oils, and thickening polysaccharides. It is because it can suppress that the biodegradability of a lubricant falls if the component of the kind mentioned above is used as a viscosity modifier.

  And it is preferable that the lubricant of this invention contains the said compound 80 mass% or more. This is because if the content ratio of the compound in the lubricant is not less than the above lower limit, the biodegradability can be sufficiently improved and the environmental load can be further reduced.

  Moreover, this invention aims at solving the said subject advantageously, The lubrication method of this invention uses one of the lubricants mentioned above, It is characterized by the above-mentioned. If the above-described lubricant is used, a desired lubricating effect can be obtained with a low environmental load.

  Here, in the lubrication method of the present invention, it is preferable to use the lubricant between the stationary ring and the rotating ring of the mechanical seal. This is because if the above-described lubricant is used at the predetermined location, a desired lubricating effect can be obtained with a low environmental load at the mechanical seal portion.

  In the lubricating method of the present invention, the lubricant is preferably used between the rotor and the housing of the liquid ring vacuum pump. This is because if the above-described lubricant is used at the predetermined location, a desired lubricating effect can be obtained with a low environmental load between the rotor and the housing of the liquid ring vacuum pump.

According to the present invention, it is possible to provide a lubricant that has excellent biodegradability and can reduce environmental load.
Further, according to the present invention, it is possible to provide a lubrication method having a low environmental load.

Hereinafter, embodiments of the present invention will be described in detail.
Here, the lubricant of the present invention can be used to lubricate between arbitrary portions of an arbitrary object and reduce friction and wear between the portions. The lubricant of the present invention is suitably used, for example, in the lubrication method of the present invention.

(lubricant)
The lubricant of the present invention contains a compound represented by the following formula (1) as a base oil and is excellent in biodegradability. The lubricant of the present invention may optionally further contain an additive.

<Compound>

[R ¹ ]
Here, in the above formula (1), R ¹ is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogenated alkyl group having 1 to 12 carbon atoms. In the present invention, the “halogenated alkyl group” refers to a group in which at least a part of hydrogen of an alkyl group is substituted with at least one selected from the group consisting of fluorine, chlorine, bromine and iodine. When R ¹ is an alkenyl group having 2 to 12 carbon atoms, the above compound contained in the lubricant may be a cis isomer or a trans isomer, A mixture thereof may also be used.

Among them, from the viewpoint of the safety of the lubricant, R ¹ is an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or a halogenated alkyl group having 1 to 8 carbon atoms. It is preferably an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or a fluorinated alkyl group having 1 to 8 carbon atoms. From the viewpoint of further improving the biodegradability of the lubricant, R ¹ is more preferably an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and an n-pentyl group ( and particularly preferably _{-CH 2 CH 2 CH 2 CH 2} CH 3) or a 2-pentenyl group _{(-CH 2 CH = CHCH 2 CH} 3). Furthermore, from the viewpoint of reducing the cost of the lubricant, R ¹ is preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an n-pentyl group.

［式（２）〜（５）中、Ｒ³は、水素原子、炭素数１以上８以下のアルキル基または下記式（６）：

（式（６）中、Ｒ⁵は、炭素数１以上１２以下のアルキル基、炭素数２以上１２以下のアルケニル基または炭素数１以上１２以下のハロゲン化アルキル基である。）で表される一価の基であり、式（５）中、Ｒ⁴は、水素原子、炭素数１以上８以下のアルキル基または下記式（６）：

（式（６）中、Ｒ⁵は、炭素数１以上１２以下のアルキル基、炭素数２以上１２以下のアルケニル基または炭素数１以上１２以下のハロゲン化アルキル基である。）で表される一価の基であり、式（５）においてＲ³およびＲ⁴は同一でも異なっていてもよく、「＊」は結合手であることを示す。］の何れかで表される一価の基である。[R ² ]
R ² represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or the following formulas (2) to (5):

[In the formulas (2) to (5), R ³ represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or the following formula (6):

(In formula (6), R ⁵ is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogenated alkyl group having 1 to 12 carbon atoms). In formula (5), R ⁴ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or the following formula (6):

(In formula (6), R ⁵ is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogenated alkyl group having 1 to 12 carbon atoms). It is a monovalent group, and in formula (5), R ³ and R ⁴ may be the same or different, and “*” represents a bond. ] Is a monovalent group represented by any one of

Here, from the viewpoint of obtaining a lubricant more easily, R ¹ in the above formula (1) and R ⁵ in the above formula (6) are preferably the same.

In addition, when R ² has an alkenyl group having 2 to 12 carbon atoms, the compound contained in the lubricant may be a cis isomer or a trans isomer, A mixture thereof may also be used.

Among these, from the viewpoint of biodegradability and safety of the lubricant, R ² is preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 4 carbon atoms. More preferably, it is a methyl group.

And as a compound mentioned above, jasmonic acid ester and dihydrojasmonic acid ester are preferable, and methyl jasmonate and methyl dihydrojasmonate are more preferable. This is because these compounds are not only excellent in biodegradability but also low in flammability and toxicity, and also in safety. In addition, the chemical stability is high and the fluidity is excellent. Among these, from the viewpoint of availability and cost, methyl dihydrojasmonate is particularly preferable as the compound.
In addition, the compound mentioned above may contain a small amount of impurities. When a compound contains an impurity, it is preferable that the content rate of the said impurity is 10 mass% or less with respect to 100 mass% of compounds.

[Content ratio]
Further, the content ratio of the above-mentioned compound is usually 50% by mass or more, preferably 80% by mass or more, more preferably 95% by mass or more, and 99% by mass with respect to 100% by mass of the lubricant. % Or more is more preferable, and may be 100% by mass. This is because if the content ratio of the compound is equal to or more than the above lower limit, the lubricant has further excellent biodegradability and can further reduce the environmental load.

<Additives>
The lubricant of the present invention can further contain one or more additives in addition to the above-described predetermined compound as the base oil. If an additive is used in combination, desired properties can be further imparted to the lubricant.
Here, the additive is not particularly limited, for example, an antioxidant, a viscosity modifier, a viscosity index improver, a surfactant, an extreme pressure agent, a friction reducing agent, a pour point depressant, a dispersant, Detergents, carrier fluids, dyes, markers, corrosion inhibitors, biocides, antistatic additives, drag-reducing agents, demulsifiers, emulsifiers, anti-fogging agents, anti-icing additives, anti-knock additives, anti-valve seat sessions Additives, lubricating additives, antiwear agents, antifoaming agents and the like can be mentioned.
In addition, from the viewpoint of ensuring high biodegradability of the lubricant and reducing environmental burden, an additive having good biodegradability is preferable as the additive.

  Here, the antioxidant having good biodegradability is not particularly limited. For example, vitamin C (ascorbic acid), vitamin E (tocopherol), sodium erythorbate, propyl gallate, sodium sulfite, coffee beans Examples include an extract (chlorogenic acid), a green tea extract (catechin), a rosemary extract, dibutylhydroxytoluene (BHT), and butylhydroxyanisole (BHA).

  Moreover, as a viscosity regulator with good biodegradability, it is not particularly limited, for example, polysaccharides such as cyclodextrin; salad oil, white squeezed oil, corn oil, soybean oil, sesame oil, rapeseed oil (canola oil), Rice oil, cocoon oil, cocoon oil, safflower oil (safflower oil), coconut oil (palm kernel oil), cottonseed oil, sunflower oil, sesame oil (pepper oil), flaxseed oil, olive oil, peanut oil, almond oil, avocado oil, Vegetable oil such as hazelnut oil, walnut oil, grape seed oil, cacao butter, peanut butter, palm oil, castor oil; animal oils such as lard, beef tallow, chicken oil, linseed oil, sheep fat, horse tallow; pectin, guar gum (guar gum) ), Xanthan gum, tamarind gum, carrageenan, propylene glycol, carboxymethylcellulose, etc. Polysaccharides; and the like.

  The viscosity index improver with good biodegradability is not particularly limited, and examples thereof include polymethacrylate, starch, cellulose, polyvinyl alcohol, polylactic acid, polycaprolactone, and polyglycolic acid.

  Furthermore, the biodegradable surfactant is not particularly limited, and examples thereof include glycerin fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, sucrose fatty acid ester, lecithin, saponin, sodium caseinate, and oxyethylene. Examples include fatty acid alcohol, sodium oleate and morpholine fatty acid salt, polyoxyethylene higher fatty acid alcohol, and the like.

  These additives may be used alone in any amount, or any two or more types may be used in combination in any amount.

[Combination ratio]
The blending ratio of the additive that can be included in the lubricant of the present application is preferably 20% by mass or less, more preferably 5% by mass or less, and more preferably 1% by mass or less with respect to 100% by mass of the lubricant. More preferably, it may be 0% by mass. This is because, if the blending ratio of the additive is not more than the above upper limit, it is possible to ensure excellent biodegradability and reduce environmental burden while imparting desired characteristics to the lubricant.

<Preparation method>
The lubricant of the present invention can be prepared by mixing and stirring the various components described above by any method.

(Lubrication method)
The lubricating method of the present invention is characterized by using the above-described lubricant. Specifically, in the lubricating method of the present invention, the lubricant can be used to lubricate, for example, a sliding surface between the rotating member and the fixed member.

Among these, in the lubrication method of the present invention, the mechanical seal stationary ring included in various devices such as a rotary pump, an oil diffusion pump, a turbo molecular pump (TMP), an ion pump, a compressor, a stirring thin film distiller, and a centrifugal thin film distiller Lubrication between the rotating ring and between the rotor of the liquid ring vacuum pump and the housing can be suitably lubricated.
When used in a liquid ring vacuum pump, the lubricant of the present invention also exhibits a function as a seal liquid.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.
And the abrasion resistance in the object location using a lubricant was confirmed by visual observation. Regarding the sealing performance, the level of liquid leakage was confirmed by reading the liquid level of the lubricant from the gauge.

Example 1
<Preparation of lubricant>
CLAIGEON (registered trademark, containing 98.0% by mass or more of methyl dihydrojasmonate) manufactured by Nippon Zeon Co., Ltd. was prepared as a lubricant.
The prepared lubricant had a biodegradability of 88% after 28 days, determined from the biochemical oxygen demand, and showed good biodegradability. Here, the degree of degradation is the measured value (BOD, mg) of the lubricant's biochemical oxygen demand relative to the theoretical oxygen demand (TOD, mg) required when the lubricant is completely oxidized. ) As a percentage (%).
<Applying lubricant>
Next, the lubricant prepared as described above was applied to a mechanical seal portion of a thin film distiller (manufactured by Hitachi, Ltd., product name “centrifugal thin film distiller”). Specifically, a lubricant was applied using a petroleum pump and a beaker to a mechanical seal portion composed of a rotating ring installed on the rotating shaft of the thin-film distillation apparatus and a stationary ring adjacent to the rotating ring. . Here, the condition for applying the lubricant was an environment at a temperature of 25 ° C.
Subsequently, a thin-film distiller having a mechanical seal portion to which the lubricant was applied was continuously operated for one year at a rotational speed of 225 rpm under reduced pressure while blowing steam into the jacket portion. Note that methyl dihydrojasmonate was introduced into the thin-film distiller in contact with the mechanical seal portion for thin-film distillation.
<Confirmation of wear resistance and sealability>
And the mechanical seal part was taken out from the thin film distiller operated as described above, and the part was visually observed. As a result, no wear was found on the sliding surface of the mechanical seal where the rotating ring and the stationary ring rub against each other, and it was confirmed that the lubricant had excellent wear resistance. Further, the degree of leakage of the lubricant from the mechanical seal portion was on the order of several ppm, and a good sealing property comparable to that of mineral oil generally used as a lubricant was confirmed.

(Example 2)
In applying the lubricant, a rotary pump (manufactured by Ebara Seisakusho, product name “Swirl Pump”) was used instead of the thin-film distiller. Further, a rotary pump having a mechanical seal portion provided with a lubricant was prepared in the same manner as in Example 1 except that the rotary pump was continuously operated for 1 year at a rotational speed of 1765 rpm under reduced pressure conditions. Granted.
The prepared lubricant showed good biodegradability as in Example 1. In addition, methyl dihydrojasmonate was introduced into the rotary pump in contact with the mechanical seal portion.
<Confirmation of wear resistance and sealability>
Then, the mechanical seal portion was visually observed in the same manner as in Example 1. As a result, no wear was found on the sliding surface of the mechanical seal, and it was confirmed that the lubricant had excellent wear resistance. Further, the degree of leakage of the lubricant from the mechanical seal portion was on the order of several ppm, and a good sealing property comparable to that of mineral oil generally used as a lubricant was confirmed.

According to the present invention, it is possible to provide a lubricant that has excellent biodegradability and can reduce environmental load.
Further, according to the present invention, it is possible to provide a lubrication method having a low environmental load.

Claims (10)

Following formula (1):

[In Formula (1), R ¹ is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogenated alkyl group having 1 to 12 carbon atoms, and R ² is hydrogen. An atom, an alkyl group having 1 to 8 carbon atoms, or the following formulas (2) to (5):

[In the formulas (2) to (5), R ³ and R ⁴ are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or the following formula (6):

(In formula (6), R ⁵ is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a halogenated alkyl group having 1 to 12 carbon atoms). It is a monovalent group, which may be the same or different, and “*” indicates a bond. ] Is a monovalent group represented by any one of ] The lubricant containing the compound represented by this as base oil. The lubricant according to claim 1, wherein R ¹ is an n-pentyl group or a 2-pentenyl group. The lubricant according to claim 1 or 2, wherein R ² is an alkyl group having 1 to 8 carbon atoms.   The lubricant according to any one of claims 1 to 3, wherein the compound is methyl jasmonate or methyl dihydrojasmonate. Further containing an antioxidant,
The antioxidant is at least one selected from the group consisting of ascorbic acid, tocopherol, sodium erythorbate, propyl gallate, sodium sulfite, chlorogenic acid, catechin, rosemary extract, dibutylhydroxytoluene, and butylhydroxyanisole. The lubricant according to any one of claims 1 to 4, wherein: Further containing a viscosity modifier,
The lubricant according to any one of claims 1 to 5, wherein the viscosity modifier is at least one selected from the group consisting of polysaccharides, vegetable oils, animal oils, and thickening polysaccharides.   The lubricant according to any one of claims 1 to 6, comprising 80% by mass or more of the compound.   A lubrication method using the lubricant according to any one of claims 1 to 7.   The lubrication method according to claim 8, wherein the lubricant is used between a stationary ring and a rotating ring of a mechanical seal.   The lubrication method according to claim 8, wherein the lubricant is used between a rotor and a housing of a liquid ring vacuum pump.