JPH11335689A - Grease and agent for preventing diffuse of base oil of grease - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject preventing agent for adding to grease containing a synthetic lubricating oil as base oil as base oil, having oil content diffusion- preventing performance higher than a conventional fluorine-based surfactant by using a specific fluorine-containing compound. SOLUTION: This preventing agent comprises a fluorine-containing compound of the formula: R<f> -Q-O-(A-O)n -R [R<f> is a 1-22C polyfluoroaliphatic hydrocarbon; Q is a 1-5C alkylene; (n) is 1-100; A is a 2-4C alkylene; R is H, a 1-18C acyl or the like]. The fluorine-containing compound is preferably obtained by subjecting a fluorine-containing hydroxy compound of the formula: R<f> -Q-OH to ring-opening addition reaction with a cyclic ether in the presence of an acid catalyst or a metal complex catalyst. The fluorine-containing hydroxy compound is obtained by a method, e.g. passing through a perfluoroalkanecarboxylic acid from a perfluoroalkyl iodine. An addition amount of the preventing agent to grease is preferably >=0.5 wt.% and <5 wt.% based on total amount of grease.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base oil diffusion inhibitor for preventing oil from diffusing or leaching in grease, and a grease containing the base oil diffusion inhibitor.

[0002]

2. Description of the Related Art In recent years, with the rapid increase in performance and miniaturization of precision instruments, there has been a demand for better properties and quality for grease used in mechanically rotating parts and sliding parts. It has come to be. For example, for grease used for various miniaturized mechanisms, motors, various bearings, switches, contacts, etc.,
High performance such as heat resistance, low temperature, and light torque are required. As a conventional grease, a grease in which a soap-based or urea-based thickener is dispersed in a base oil composed of a low-viscosity synthetic lubricating oil is used.

[0003]

However, in conventional greases using a synthetic lubricating oil as a base oil, the oil or oil additive in the grease diffuses or oozes out of the coated surface with the lapse of time after the application of the grease. was there. Particularly, when the viscosity of the base oil is low, when the consistency of the grease is soft, or when the temperature at the time of use or storage is high, there is a problem that this tendency becomes remarkable.

[0004] The cause of this problem is that grease is a semi-solid in which a solid thickener is mixed and dispersed in a liquid base oil, so that the liquid base oil separates from the grease over time and the oil content increases. It is thought that it is to spread as. The spread oil causes problems such as soiling equipment, causing a contact failure, and spreading on the surface of the material and adversely affecting the base material such as plastic.

As means for solving the above problem, Japanese Patent Publication No.
No. 46999 proposes a method in which a fluorine-based surfactant having a perfluorocarbon chain as a hydrophobic group in the molecule and having oxyethylene as a hydrophilic group is added to grease. However, the grease to which the fluorine-based surfactant is added has a problem that the compatibility with the base oil is low, bubbles are generated, and bubbles generated once are difficult to disappear, and the stability is insufficient. No prevention performance was obtained.

[0006]

Means for Solving the Problems The inventors of the present invention have studied to obtain a grease additive having a higher diffusion preventing performance than conventional fluorine-based surfactants. As a result, they have found that a specific fluorine-containing compound has an extremely high effect of preventing oil diffusion, and have led to the present invention. That is, the present invention provides a base oil diffusion inhibitor to be added to grease containing a synthetic lubricating oil as a base oil, which is characterized by comprising a fluorine-containing compound represented by the following formula 1.

R ^f -Q-O- (A-O) _n -R Formula 1 wherein the symbols in Formula 1 have the following meanings. R ^f : a polyfluoroaliphatic hydrocarbon group having 1 to 22 carbon atoms. Q: a linear or branched alkylene group having 1 to 5 carbon atoms. n: an integer from 1 to 100. A: an alkylene group having 2 to 4 carbon atoms, wherein a hydrogen atom of the alkylene group may be substituted with an aromatic hydrocarbon group, an alkoxy group, or a phenoxy group. n is 2 to 1
A in the formula when it is 00 may be the same or different. R: a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an acyl group having 1 to 18 carbon atoms.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The base oil diffusion inhibitor of the present invention comprises a specific fluorinated compound, which is a fluorinated compound represented by the formula 1. The “hydrocarbon group” in the present invention means a hydrocarbon group composed of only carbon atoms and hydrogen atoms in principle, and generically refers to both “aliphatic hydrocarbon group” and “aromatic hydrocarbon group”. As the aliphatic hydrocarbon group, an alkyl group and an alkenyl group are preferable. One or more hydrogen atoms of the aliphatic hydrocarbon group is
It may be substituted by an aromatic hydrocarbon group, for example, a benzyl group. As the aromatic hydrocarbon group, a phenyl group is preferable.

R ^f in Formula 1 is a polyfluoroaliphatic hydrocarbon group having 1 to 22 carbon atoms (hereinafter, the polyfluoroaliphatic hydrocarbon group will be referred to as R ^f group). The R ^f group is a group in which two or more hydrogen atoms in an aliphatic hydrocarbon group have been substituted with fluorine atoms. The carbon number of the R ^f group is preferably from 1 to 16, particularly preferably from 4 to 16, and particularly preferably from 6 to 14. The number of fluorine atoms in the R ^f group is expressed by (number of fluorine atoms ^the R ^f group) / (hydrogen atom in the aliphatic hydrocarbon group having the same carbon number corresponding to ^the R ^f group) × 100 (%) In this case, it is preferably at least 60%, particularly preferably at least 80%.
Further, the R ^f group preferably has a linear structure or a branched structure,
Particularly, a linear structure is preferable. In the case of a branched structure, it is preferable that the branched portion is a short chain having about 1 to 3 carbon atoms and exists at the terminal of the R ^f group.

The R ^f group is a perfluoroaliphatic hydrocarbon group (hereinafter referred to as an R ^F group), and preferably has a linear structure. The ^RF group is a group in which substantially all of the hydrogen atoms in the aliphatic hydrocarbon group have been replaced with fluorine atoms. The R ^F group preferably has 1 to 16 carbon atoms, and particularly preferably 6 to 14 carbon atoms.
R ^F group _{is, F (CF 2) m -} (m is 1-18 of integral) groups linear structure represented by are preferred. m is preferably from 4 to 16, and particularly preferably from 6 to 14.

The R ^F group having a linear structure is obtained by telomerization of C ₂ F ₅ I with tetrafluoroethylene.
The branched alkyl group can be obtained by oligomerizing a fluorine-containing monomer such as tetrafluoroethylene or hexafluoropropylene with a catalyst such as KF or CsF.

The fluorine-containing compound may be a mixture of two or more compounds having different carbon numbers in the R ^f group. In particular, R
^A mixture mainly containing a fluorine-containing compound having 6 to 14 carbon atoms in the ^f group and having an average carbon number of 8 to 10 in the R ^f group is preferable.

Q in the fluorine-containing compound has 1 to 1 carbon atoms.
5 linear or branched alkylene groups. The carbon number of Q is preferably 2, 3 or 4, and particularly preferably 3 or 4. Further, Q is preferably an alkylene group having 3 carbon atoms. When Q is an alkylene group having 3 carbon atoms, the fluorine-containing compound is a compound having excellent chemical stability and heat resistance.

Q is, for example, an ethylene group, a trimethylene group, a tetramethylene group, a propylene group [—CH ₂
CH (CH ₃₎ -], a butylene group [-CH (CH ₃₎ C
_{H 2 CH 2 -, - CH} 2 CH (CH 3) CH 2 -, - C
_{H (CH 3) CH (CH} 3) -] and the like.

In the fluorine-containing compound, n represents an integer of 1 to 100, preferably 2 to 50. The fluorine-containing compound of the present invention may be a mixture of two or more compounds in which n is different, and even in that case, the average value of n is preferably in the range of 1 to 50, and particularly preferably 2 to 30. It is preferably within the range.

A in the fluorine-containing compound has 2 to 2 carbon atoms.
4, wherein a hydrogen atom of the alkylene group may be substituted with an aromatic hydrocarbon or an alkoxy group. The A, an ethylene group, a tetramethylene group, a propylene _{group, -CH (C 6 H 5)} CH 2 -, - CH
(CH ₂ OR ¹ ) CH ₂ — and the like, and an ethylene group,
A propylene group or a tetramethylene group is preferred. However R ¹ represents an alkyl group having 1 to 10 carbon atoms, as R ¹ is a methyl group, a butyl group or a 2-ethylhexyl group, preferred.

When n is 2 to 100, A in the formula 1
May be the same or different. When they are different, A is preferably two or three, and more preferably two. One or two types of A in the fluorine-containing compound are preferably present, and in particular, two types of an ethylene group and a propylene group are preferably present.

The structure of the (A—O) _n moiety in Formula 1 is preferably a structure formed by a ring-opening addition reaction of a cyclic ether described later, and is preferably oxyethylene, oxypropylene, oxy (1,2). -Butylene), oxy (2,3-butylene), oxy (isobutylene), oxy (trimethylene), oxy (1 or 2-methyltrimethylene), oxy (1 or 2-phenoxymethylethylene), oxy (tetramethylene) , Oxy (1 or 2-oxyphenylethylene), oxy (1 or 2
-Alkoxyethylene), and a structure in which two or more of one or more selected from these are linked. Of these, a structural oxyalkylene group or a polyoxyalkylene group of the (A—O) _n portion in Formula 1 is preferable, a polyoxyalkylene group is particularly preferable, and a polyoxyethylene group and / or a polyoxypropylene group is particularly preferable. preferable. Further, the (A-O) _n part in the formula 1 is 1
It is preferable that at least one oxyethylene group and at least one oxypropylene group have a block-like or random-like structure.

The (A—O) _n moiety is preferably formed by a ring-opening addition reaction of a cyclic ether.
As the cyclic ether, a compound containing a 3- to 5-membered cyclic ether group having one oxygen atom in the ring is preferable,
Particularly, a compound (monoepoxide) having one three-membered cyclic ether group is preferable. Further, as the cyclic ether,
Alkylene oxides having 2, 3 or 4 carbon atoms are preferred.

Specific examples of the cyclic ether include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide, oxetane, methyloxetane, phenylglycidyl ether, tetrahydrofuran, styrene oxide,
And alkyl glycidyl ether. Examples of the alkyl glycidyl ether include methyl glycidyl ether, butyl glycidyl ether, (2-ethylhexyl) glycidyl ether, and the like.

Preferred cyclic ethers are ethylene oxide, propylene oxide, and tetrahydrofuran. A formed by ring opening of tetrahydrofuran is a tetramethylene group. One or more types of cyclic ethers can be used, and it is preferable to use two or more types. When two or more cyclic ethers are used, a mixture of two or more cyclic ethers may be used in the reaction at the same time, or two or more cyclic ethers may be used in the reaction sequentially.

R in the fluorine-containing compound is a hydrogen atom,
A hydrocarbon group having 1 to 18 carbon atoms or an acyl group having 1 to 18 carbon atoms is shown. When R is a hydrocarbon group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms is preferable,
Particularly, an alkyl group having 1 to 5 carbon atoms is preferable, and particularly, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and n
-A pentyl group is preferred. When R is an acyl group having 1 to 18 carbon atoms, the acyl group is preferably an acyl group having 1 to 10 carbon atoms, particularly preferably an acyl group having 1 to 6 carbon atoms. Among them, R is preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

As the fluorine-containing compound represented by the formula 1,
It is preferable that R is a hydrogen atom, n is 2 to 100, and A is an alkylene group having 2 to 4 carbon atoms. Further, as the fluorine-containing compound represented by the formula 1, the following formula 1
The compound represented by a is preferred.

[0024]

Embedded image R ^f -Q- (CH ₂ CH ₂ O) _k · [CH ₂ CH (CH ₃ ) O] _m -H Formula 1a

However, the symbols in the formula 1a have the following meanings: (CH ₂ CH ₂ O) and [CH ₂ CH (CH ₃ )
O] may be a block or a random pattern, and is preferably a block. R ^f and Q: the same meanings as in Formula 1. k and m: each independently represents an integer of 1 to 99, and k +
m is 2-100.

Further, the compound represented by the formula 1a is preferably a compound represented by the following formula 1b.

Specific examples of the fluorine-containing compound (Formula 1) include, but are not limited to, the following compounds.
However, in the following compounds, the portion corresponding to the R ^f group may have a linear structure or a branched structure, and a linear structure is preferable. When there is a polyoxyalkylene chain containing two or more oxyalkylene groups, the way of connection may be block or random. The (C ₃ H ₆ O) portion represents an oxypropylene group, and may be [CH (CH ₃ ) CH ₂ O] or [CH ₂ CH
(CH ₃ ) O]. Also (C ₄ H ₈ O)
The moiety is a ring-opened product of tetrahydrofuran (CH ₂ C
H ₂ CH ₂ CH ₂ O).

The fluorine-containing compounds in the present invention can be used alone or in combination of two or more. C ₈ F
₁₇ C ₂ H ₄ O (C ₃ H ₆ O) ₁₀ H, C ₈ F ₁₇ C ₂ H ₄ O (C ₃ H ₆ O) ₄・ (C ₂ H ₄ O) ₈ H, C
₈ F ₁₇ C ₂ H ₄ O (C ₂ H ₄ O) ₁₃ H, C ₈ F ₁₇ C ₂ H ₄ O (C ₄ H ₈ O) ₃・ (C ₂ H ₄ O) ₁₀ H
, C ₈ F ₁₇ C ₃ H ₆ O (C ₃ H ₆ O) ₁₀ H, C ₈ F ₁₇ C ₃ H ₆ O (C ₃ H ₆ O) ₄・ (C ₂ H
₄ O) ₈ H, C ₈ F ₁₇ C ₃ H ₆ O (C ₂ H ₄ O) ₁₃ H, C ₈ F ₁₇ C ₃ H ₆ O (C ₄ H ₈ O) ₃・ (C
₂ H ₄ O) ₁₀ H, C ₈ F ₁₇ C ₄ H ₈ O (C ₃ H ₆ O) ₁₀ H, C ₈ F ₁₇ C ₄ H ₈ O (C ₃ H ₆ O)
₄・ (C ₂ H ₄ O) ₈ H, C ₈ F ₁₇ C ₄ H ₈ O (C ₂ H ₄ O) ₁₃ H, C ₈ F ₁₇ C ₄ H ₈ O (C ₄ H ₈
O) ₃・ (C ₂ H ₄ O) ₁₀ H, C ₈ F ₁₇ C ₄ H ₈ O [CH (C ₆ H ₅ ) CH ₂ O] ₂・ [CH (CH ₂
OCH ₃ ) CH ₂ O] ₄ H, C ₈ F ₁₇ C ₄ H ₈ O (C ₃ H ₆ O) ₄・ (C ₂ H ₄ O) ₈ CH ₃ , C ₈ F
₁₇ C ₄ H ₈ O (C ₃ H ₆ O) _4. (C ₂ H ₄ O) ₈ COC ₁₈ H ₃₇ .

The fluorine-containing compound of the present invention is preferably synthesized by subjecting a fluorine-containing hydroxy compound represented by the following formula 2 to a ring-opening addition reaction of a cyclic ether. R ^f -Q-OH... Formula 2 where the symbols in Formula 2 have the same meanings as in Formula 1. For example, when R ^{f in} Formula 2 is an R ^F group and Q has 1 carbon atom, the fluorine-containing hydroxy compound (R
For ^F CH ₂ OH), and the telomerization perfluoroalkyl iodine obtained by telomerization (R ^F I) adding ethylene alkali treatment to perfluoroalkyl ethylene _{^{(R F CH = CH 2)}} , then par A method of oxidizing fluoroalkylethylene to perfluoroalkanecarboxylic acid (R ^F COOH), and further reducing perfluoroalkanecarboxylic acid with NaBH ₄ or the like may be mentioned.

When R ^{f in} Formula 2 is an R ^F group and Q has 2 carbon atoms, the fluorine-containing hydroxy compound [R ^F (C
In the case of H ₂ ) ₂ OH], there is a method in which ethylene is inserted into R ^F I to obtain R ^F (CH ₂ ) ₂ I, and then the terminal iodine atom is replaced with a hydroxyl group. When R ^f in the formula 2 is a R ^F group, the fluorine-containing hydroxy compound in the case the number of carbon atoms of Q is 3 _{^{[R F (CH 2) 3}} OH], the R ^F I
Allyl alcohol is added to R ^F CH ₂ CHICH ₂
After OH, a method of replacing an iodine atom with hydrogen by a reducing agent may be mentioned.

When R ^{f in} Formula 2 is an R ^F group and Q has 4 carbon atoms, the fluorine-containing hydroxy compound [R ^F (CH
₂ ) ₄ OH], 3-buten-1-ol is added to the above R ^f I to form [R ^F CH ₂ CHI (CH ₂ ) ₂ OH].
After that, there is a method in which the iodine atom is replaced with hydrogen by a reducing agent to obtain.

A method for synthesizing R ^f CH ₂ CH ₂ CH ₂ (OH) CH ₃ which is an isomer of the fluorine-containing hydroxy compound [R ^F (CH ₂ ) ₄ OH] when Q has 4 carbon atoms Is a method in which the above R ^F CH = CH ₂ is obtained by adding a predetermined radical initiator in a large amount of ethanol solvent, stirring while heating, and adding ethanol by a radical addition reaction. R ^F (CH ₂ ) ₅ OH having 5 carbon atoms of Q
The method of synthesis, after the added 4-penten-1-ol _{^{R F I [R F CH 2}} CHI (CH 2) 3 OH], a method of replacing a hydrogen iodine atom with a reducing agent is there.

Next, the cyclic ether is subjected to a ring-opening addition reaction to the fluorine-containing hydroxy compound (formula 2) obtained by the above method. When two or more cyclic ethers are subjected to a ring-opening addition reaction, they may be mixed and reacted, or may be sequentially reacted. When only one cyclic ether is used, 2
When using more than one species, they may be charged all at once or gradually added to the reaction system.

The amount of the fluorinated hydroxy compound (formula 2) varies depending on the amount of the cyclic ether compound added.
Considering the stirring conditions of the reactor, etc., 1/1 of the internal capacity of the reactor
It is preferable to charge 0 or more. In particular, considering the volumetric efficiency, 80-95% by volume after adding the cyclic ether.
It is desirable that it is.

The ring-opening addition reaction is preferably carried out in the presence of a catalyst. As the catalyst, an alkali metal catalyst, an acid catalyst, and a metal complex catalyst are preferable, and an acid catalyst and a metal complex catalyst are particularly preferable. Examples of the alkali metal catalyst include KOH,
Examples include a three-way catalyst composed of NaOH, CsOH, and NaBH ₄ / NaI / I _2. Examples of the acid catalyst include BF ₃ , and examples of the metal complex catalyst include a complex metal cyano compound complex.

When the ring-opening addition reaction is carried out under strong alkali conditions, a side reaction of elimination of HF at the R ^f portion may occur. Therefore, when an alkali metal catalyst is used, it is a mild alkali catalyst. It is preferable to use a three-way catalyst consisting of NaBH ₄ / NaI / I ₂ . Further, when an acid catalyst is used, if the acidity of the catalyst is too strong, HF is generated at the R ^f portion.
This may cause a side reaction of elimination of
In order to suppress the reaction, it is preferable to use a diluting solvent as needed. Examples of the diluting solvent include glyme, diglyme, triglyme, and ether solvents such as methyl-t-butyl ether.

The reaction temperature of the addition reaction of the cyclic ether is-
It is preferably from 20 to 180 ° C, particularly preferably from 0 to 130 ° C. In the case of using a diluting solvent, when the diluting solvent is a low boiling point diluting solvent, in consideration of an increase in internal pressure,
The reaction is preferably carried out at a temperature lower than (the boiling point of the solvent +20) ° C.

The compound obtained by subjecting the fluorinated hydroxy compound (formula 2) to a ring-opening addition reaction of a cyclic ether is a fluorinated compound (formula 1) in which the terminal is a hydroxyl group (R is a hydrogen atom), By modifying the terminal hydroxyl group (for example, esterification or alkylation), various properties can be adjusted.

The esterification is preferably carried out by reacting an organic carboxylic acid. As the organic carboxylic acid, acetic acid, propionic acid, butanoic acid, 2-ethylhexanoic acid (octylic acid), 3,5,5 Monovalent carboxylic acids such as 5-trimethylhexanoic acid (isononanoic acid), oleic acid, or stearic acid, esters of the monovalent carboxylic acids with low-boiling alcohols, acetic anhydride, propionic anhydride, butanoic anhydride, n-anhydride; Examples include monovalent carboxylic anhydrides such as butyric acid.

In the esterification, the above-mentioned organic carboxylic acid is
In addition to the fluorine-containing compound (formula 1) where the terminal is a hydroxyl group (R is a hydrogen atom), the mixture is stirred without heating or in the presence of a catalyst while heating, and then dehydration, dealcoholization, or removal of unreacted acid is performed. It is preferable to carry out the method.
As the catalyst, a trace acid catalyst such as paratoluenesulfonic acid and sulfuric acid, and an alkali catalyst such as potassium hydroxide and sodium hydroxide are preferable.

The alkylation includes a method of reacting with a monohaloalkyl under strong alkaline conditions and a method of using a dialkylsulfuric acid. The reaction using an alkylating agent such as an alkylsulfuric acid is preferred in that the elimination reaction of HF can be suppressed. preferable.

The fluorine-containing compound (formula 1) obtained by the above-mentioned various reactions may be subjected to an acid treatment using sulfuric acid, phosphoric acid or the like, or an adsorption treatment using synthetic magnesium silicate, activated clay, activated carbon or the like, if necessary. It is preferred to purify it by treatment or the like to have high purity.

The base oil diffusion inhibitor of the present invention comprises the above-mentioned fluorine-containing compound. The base oil diffusion inhibitor of the present invention is used by being added to grease containing a synthetic lubricating oil as a base oil.

Examples of the synthetic lubricating oil include poly (α-olefin) oil, cooligomer oil of ethylene unit and other α-olefin unit, silicone oil, ester oil composed of dialkyl ester of dicarboxylic acid, lower alcohol and propylene oxide. And polyglycol oil obtained by ring-opening polymerization of an alkylene oxide.

The grease is based on a synthetic lubricating oil, and it is usually preferable to include a thickener together with the synthetic lubricating oil. As the thickener, a soap type (metal soap type, composite soap type, etc.) or a urea type thickener is preferable.

The amount of base oil diffusion inhibitor added to grease is
0.01% by weight or more, preferably 0.1 to 15% by weight, particularly preferably 0.1 to 15% by weight, based on the total weight of the grease.
It is preferably at least 5 and less than 5.0% by weight. The effect of the fluorine-containing compound of the present invention is exhibited by adding a small amount, but if the amount is too small, a sufficient oil diffusion preventing effect may not be obtained. If the amount is too large, the effect is saturated, and it is economically disadvantageous.

The grease of the present invention to which the base oil diffusion inhibitor of the grease is added can be used for precision equipment such as a helicoid part of a camera, a diaphragm mechanism, a bearing mechanism of a timepiece, various bearings such as a rotating shaft of a micromotor, and electronic equipment. It can be used for applications such as mechanical parts and switches. The fluorine compound of the present invention,
Since it has better chemical resistance and heat resistance than conventional additives, it also has the effect of improving the quality of grease. Further, when the urea thickener is contained in the grease, there is also an effect that the affinity between the thickener and the synthetic lubricating oil is improved. further,
The base oil diffusion inhibitor of the present invention also has an advantage of exhibiting diffusion prevention performance even when the grease contains a fluorinated oil [eg, poly (trifluorochloroethylene), perfluoropolyether, etc.].

[0048]

The mechanism by which the base oil diffusion inhibitor of the present invention exerts an excellent effect on the conventional base oil diffusion inhibitor is not necessarily clear, but is presumed as follows.

The fluorine-containing compound in the present invention does not have an amide bond or an ester group such as a phosphate ester between a perfluoroalkyl group and an oxyethylene group, unlike the conventionally known fluorine-based surfactant. Therefore, it is a compound which is hardly foamed, has no stability problem such as formation of a strong acid perfluorocarboxylic acid or perfluorosulfonic acid by hydrolysis, and has excellent compatibility with synthetic lubricating oil. Further, since the compound contains an oxyalkylene group that is relatively more hydrophilic than the R ^f group, when added to a synthetic lubricating oil, a hydrophobic R ^f group is added to the surface of the lubricating oil to form an oxyalkylene group. This is considered to be excellent in the effect of regularly arranging them on the lubricating oil side. The effect of regularly covering ^Rf groups on the lubricating oil surface is superior to that of conventional fluorine-based surfactants.
It is assumed that a more excellent diffusion prevention effect is exhibited.

[0050]

EXAMPLES [Preparation of Grease A] Poly (α-olefin) (having a kinematic viscosity of 6 cSt at 100 ° C.) was used as a base oil, and lithium hydroxystearate was used as a thickener.
Grease A contained 0% by weight. The consistency number of grease A was 1, and the dropping point was 203 ° C. Note that the consistency number and the drop point are based on JIS-K
It was measured according to the method described in 2220.

[Preparation of Grease B] Grease B was prepared by using ethylhexyl sebacate as a base oil and containing a triurea compound as a thickener at 8% by weight. The consistency number of grease B was 1, and the dropping point was 260 ° C.

In the following, synthesis examples (Examples 1 to 6) and Examples (Example 7)
To 13) and Comparative Examples (Examples 14 to 22) to describe the present invention in detail. Example 1 Synthesis of Fluorine-Containing Compound 1 500 g of F (CF ₂ ) ₈ (CH
_{2) 3} OH was added as a powder, a zinc hexacyanocobaltate complex was added 0.25 g. The mixture was heated to 65 ° C and dissolved with stirring. The temperature was raised to 80 ° C, and 546 g of propylene oxide (hereinafter referred to as PO) was maintained at 80 ° C.
Was continuously introduced over 3 hours.

After completion of the reaction, unreacted PO was distilled off under reduced pressure to obtain a crude product. The chelating reagent was added to remove the heavy metals of the catalyst, and KW-1000 and KW-
600 parts (all manufactured by Kyowa Chemical Industry Co., Ltd.) were added in order of 1 part by weight to 100 parts by weight of the crude product, respectively, to adsorb the inorganic compound. Dehydration, filtration, and drying were performed to obtain a fluorine-containing compound 1. The hydroxyl value of fluorinated compound 1 was 57.4 mgKOH / g. NMR spectra of the product ( ¹ H-NMR, ¹⁹ F-NMR, and ¹³ C-NMR)
NMR), F (CF ₂ ) ₈ (CH ₂ ) ₃ O [CH
₂ CH (CH ₃ ) O] _n H (however, the average value of n is 8.
6. ) Generation was confirmed.

[Example 2: Synthesis of fluorinated compound 2] PO / ethylene oxide (hereinafter referred to as EO) instead of PO =
The reaction was carried out in the same manner as in Example 1 except that a 40/60 (weight ratio) mixture was used, to obtain a fluorine-containing compound 2. The hydroxyl value of fluorinated compound 2 was 56.8 mgKOH / g.
According to the NMR spectrum of the product, F (CF ₂ ) ₈ (C
H ₂ ) ₃ O [CH ₂ CH (CH ₃ ) O] _p (CH ₂ CH ₂
O) _q H (However, the sequence of PO and EO is random. The average value of p + q is 10, and p: q = 4: 6
It is. ) Generation was confirmed.

Example 3 Synthesis of Fluorine-Containing Compound 3 500 g of F (CF) was placed in a stainless steel pressure-resistant autoclave.
₂ ) ₈ (CH ₂ ) ₃ OH was added as powder, 0.5 g of BF ₃ etherate and 250 g of glyme as a diluent
Was added. Dissolve with stirring, raise the temperature to 30 ° C,
While maintaining 30 ° C., tetrahydrofuran (hereinafter referred to as THF)
) / EO = 60/40 mixture was continuously introduced over 3 hours.

After further aging for 5 hours, unreacted THF / EO and solvent glyme were distilled off under reduced pressure to obtain a crude product. After neutralizing the acid content by adding a 10% aqueous sodium hydroxide solution, 1 part by weight of KW-1000 and KW-600 (same as above), which are adsorbents, were sequentially added to 100 parts by weight of the crude product. To adsorb the inorganic compound. Dehydration, filtration, and then drying, the fluorine-containing compound 3
I got The hydroxyl value of the fluorine-containing compound 3 is 59.2 mgK
OH / g. According to the NMR spectrum of the product,
F (CF ₂ ) ₈ (CH ₂ ) ₃ O (CH ₂ CH ₂ CH ₂ C
H ₂ O) _p (CH ₂ CH ₂ O) _q H (However, the sequence of THF and EO is random. The average value of p + q is 7.7, and p: q = 6: 4.) Generation was confirmed.

[Example 4: Synthesis of fluorinated compound 5] THF
The reaction was carried out in the same manner as in Example 3 except that 546 g of EO was used instead of / EO to obtain a fluorine-containing compound 5. The hydroxyl value of fluorinated compound 4 was 56.3 mgKOH / g. According to the NMR spectrum of the product, F (CF ₂ )
₈ (CH ₂ ) ₃ O (CH ₂ CH ₂ O) _n H (where n
Is 11.8. ) Generation was confirmed.

Example 5 Synthesis of Fluorine-Containing Compound 6 Instead of F (CF ₂ ) ₈ (CH ₂ ) ₃ OH as an initiator, F
The reaction was carried out in the same manner as in Example 3 except that (CF ₂ ) ₈ CH ₂ CH ₂ CH (CH ₃ ) OH was used.
I got The hydroxyl value of the fluorine-containing compound 6 is 56.3 mgK
OH / g. According to the NMR spectrum of the product,
F (CF ₂ ) ₈ CH ₂ CH ₂ CH (CH ₃ ) O (CH ₂
The average value of the _{CH 2 CH 2 CH 2 O)} m (CH 2 CH 2 O) n H ( provided that m + n is 11.5, m: n = 6: 4
It is. ) Generation was confirmed.

[Evaluation Method of Oil Diffusion Prevention Effect] A test on the oil diffusion prevention effect of the base oil diffusion inhibitor according to the present invention was carried out by the following method. First, a test method will be described with reference to FIG. First, grease 1 was injected with a syringe into 0.05 cc.
Each sample was taken and applied to the rough surface side of a ground glass plate (10 cm × 10 cm) 2 in a circular chevron shape. A flat washer 3 having a thickness of 0.35 mm was placed on each of the four corners for clearance. Next,
A ground glass plate 4 of the same type was placed on top, and the grease 1 was pressed so as to have a 15 mm circular shape with the rough surfaces facing each other. And put in a thermostat (80 ° C)
It was left for 4 hours, and the diffusion width (mm) of the diffusion portion 5 where the rough surface of the ground glass plates 2 and 4 became translucent due to the diffusion or oozing out of the oil component was measured. Further, the diffusion width (%) was determined by applying the diffusion width to the following equation. Diffusion rate (%) = (Diffusion width−15) ÷ 15 × 100

Examples 1 to 10 Fluorine-containing compounds 1 to 5 synthesized in Synthesis Examples 1 to 5 were added to the above grease A or B.
Was added to evaluate the oil diffusion preventing effect. In this embodiment, 100 parts by weight of grease was added with 2 parts of a fluorine compound.
What was added by weight was used. Table 1 shows the type of grease used, the type of base oil diffusion inhibitor, and the evaluation results.

[Comparative Examples 1 and 2] The effect of preventing oil diffusion was confirmed in the same manner as in Example 1 except that the fluorine-containing compound 1 was not added to the grease. Table 1 shows the evaluation results.

[Comparative Examples 3 and 4] A compound represented by the following formula 7 (Japanese Patent Publication No. 4-469) instead of the base oil diffusion inhibitor of Example
99, wherein the average value of x in the formula is 1
0. ) Was added to the grease. 2 parts by weight of the compound represented by the following formula 7 was added to 100 parts by weight of grease. Table 1 shows the results of evaluating the oil diffusion preventing effect in the same manner as in Example 1.

[0063]

Embedded image C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) (CH ₂ CH ₂ O) _X H Formula 7

[0064]

[Table 1]

[0065]

The base oil diffusion inhibitor of the present invention has excellent performance for preventing grease diffusion. The diffusion preventing effect is remarkable as compared with conventional fluorine-based surfactants,
The effect can be exhibited with a smaller amount than the addition amount in a conventional nitrogen surfactant. Further, even if the type of grease is changed, the same effect is exerted, so that the grease is excellent in versatility and practicality.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an oil diffusion test method in an example.

[Explanation of symbols]

 1: Grease 2, 4: Ground glass plate 3: Flat washer 5: Diffusing part

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Naoyuki Okuno Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama, Kanagawa

Claims (6)

[Claims] 1. A base oil diffusion inhibitor added to grease containing a synthetic lubricating oil as a base oil, comprising a fluorine-containing compound represented by the following formula 1. R ^f -Q-O- (A-O) _n -R Formula 1 wherein the symbols in Formula 1 have the following meanings. R ^f : a polyfluoroaliphatic hydrocarbon group having 1 to 22 carbon atoms. Q: a linear or branched alkylene group having 1 to 5 carbon atoms. n: an integer from 1 to 100. A: an alkylene group having 2 to 4 carbon atoms, wherein a hydrogen atom of the alkylene group may be substituted with an aromatic hydrocarbon group, an alkoxy group, or a phenoxy group. n is 2 to 1
A in the formula when it is 00 may be the same or different. R: a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an acyl group having 1 to 18 carbon atoms. 2. The base oil diffusion inhibitor according to claim 1, wherein R is a hydrogen atom, n is 2 to 100, and A is an alkylene group having 2 to 4 carbon atoms. 3. The base oil diffusion inhibitor according to claim 1, wherein A is at least one group selected from an ethylene group, a propylene group, and a tetramethylene group. 4. The base oil diffusion inhibitor according to claim 1, wherein Q is a linear or branched alkylene group having 3 or 4 carbon atoms. 5. A grease containing the base oil diffusion inhibitor according to claim 1. 6. The grease according to claim 5, which contains the base oil diffusion inhibitor in an amount of 0.1% by weight or more and less than 5 parts by weight.