JP5429285B2 - Lubricating grease composition for reciprocating sliding and manufacturing method thereof - Google Patents

Description

  The present invention relates to a lubricating grease composition for reciprocating sliding and a method for producing the same. More specifically, the present invention relates to a lubricating grease composition for reciprocating sliding using a base oil mixture composed of a non-fluorine base oil and a fluorine base oil that are not compatible with each other, and a method for producing the same.

  Typical industrial small parts having a reciprocating sliding mechanism include a micro switch and an electromagnetically driven valve. For example, an encapsulated microswitch is a component that causes an external force applied to an actuator part to be transmitted to an internal spring mechanism to move a movable contact and open / close the switch. The external force applied to the actuator is replaced with a reciprocating movement of the plunger for opening and closing the switch. In this case, the sliding between the plunger and the enclosing case member is repeatedly performed in a reciprocating manner with a movable range of several mm.

  For this type of application, mineral oil and synthetic hydrocarbon oil [PAO] greases have been used in the past, but in recent years, encapsulated microswitches used under high temperature conditions of 120 to 150 ° C or higher, for example. However, there is a problem that the durability of the grease is insufficient.

  In terms of high temperature durability, fluorine-based grease has been used in the past, and it is used under severe conditions that require not only high temperature durability but also low temperature characteristics, oxidation stability, and chemical resistance. Yes. Fluorine grease is generally composed of perfluoropolyether oil as base oil and tetrafluoroethylene homopolymer [PTFE] or copolymer of tetrafluoroethylene and hexafluoropropene [HFP] as a thickener. Has been. However, these fluorinated greases have the disadvantage that they are not compatible with resins, rubbers, metals, etc., which are materials to be lubricated.

  When used in a rolling device such as a rolling bearing, the grease interposed between the ball and the transfer surface not only contributes to lubrication but also exists in the surrounding portion that does not contribute to sliding. Since the grease also moves in the bearing by the rotational motion and is supplied to the sliding portion, it can contribute to lubrication later, so that no problem is observed in this case.

  On the other hand, in the reciprocating motion that repeats sliding at regular intervals, the grease is easily scraped from the sliding portion, and the grease once scraped from the sliding portion is difficult to be supplied to the sliding portion again. In particular, in the case of fluorine-based grease, an oil film necessary for lubrication is not formed, and as a result, wear occurs and the friction coefficient increases, resulting in a problem that durability cannot be obtained.

  Patent Document 1 describes a grease comprising a hydrogenated mineral oil and / or a synthetic lubricating oil, a fluoropolyether and a thickener used at a specific mixing ratio, and an ester oil, 12-hydroxystearic acid. A grease composed of azelaic acid and lithium hydroxide with a perfluorinated oil and PTFE added is shown as Example 4, and its evaluation tests are for fixing temperature, weight loss due to evaporation, and oil separability. The bearing high temperature life has not been evaluated, and no specific description of its use has been found.

  The applicant himself has made several proposals for grease used in sliding parts such as electrical contacts.

  Patent Document 2 describes a lubricating grease composition containing a perfluoropolyether oil, a synthetic lubricating oil, and a thickener, and the evaluation thereof is low temperature torque, rotational life, wear scar diameter (shell wear test). Has been done about.

  Patent Document 3 describes a lubricating grease composition containing a fluorinated oil and a lithium-based composite soap thickener in a base oil composed of a synthetic hydrocarbon oil, an ester oil or an ether-based synthetic oil. Evaluation is conducted on a pin-on-disk wear test.

  Patent Document 4 is configured as a lubricating grease composition excellent in extreme pressure property and wear resistance in which a perfluoropolyether base oil is mixed with a fatty acid metal salt and a fluororesin as a thickener.

JP 7-268370 A JP 2003-096480 A JP 2006-182923 A JP 2007-154084 A

  An object of the present invention is a lubricating grease composition for reciprocating sliding in which a thickener and a fluororesin are contained in a base oil mixture composed of a non-fluorinated base oil and a fluorinated base oil. The object is to provide a product having special characteristics.

An object of the present invention is to provide a non-fluorine-based grease and a non-fluorine-based grease having a dropping point of 250 ° C. or higher, containing a composite metal soap thickener of an aliphatic dicarboxylic acid and a monoamide monocarboxylic acid in a non-fluorine base oil. According to the lubricating grease composition for reciprocating sliding used in the actuator part of a micro switch or electromagnetically driven valve consisting of two types of grease mixture of fluorine grease containing fluorine resin powder in fluorine base oil incompatible with base oil Achieved.

  This non-fluorine base oil consists of a mixture of two types of grease: non-fluorine grease containing a composite metal soap thickener in a non-fluorine base oil and fluorine grease containing a fluororesin powder in a fluorine base oil. By using a non-fluorine grease containing composite metal soap in the base, a drop point corresponding to the upper limit temperature established as a grease is 250 ° C or higher, resulting in low evaporation loss and oil separation, and SRV test ( A stable lubricating grease composition is obtained in which the fluctuation range of the friction coefficient in the reciprocating motion test is small and the fluctuation is small.

  In this way, even under conditions where the fluorinated grease is not sufficiently held and supplied to the sliding portion, the base oil mixture composed of the non-fluorinated base oil and the fluorinated base oil which are not compatible with each other is contained. Use a lubricating grease composition containing a metal composite soap thickener and fluororesin powder, and use a metal composite soap-containing non-fluorine base oil (non-fluorine grease) with a dropping point above a certain temperature. Thus, while maintaining the heat resistance and durability of the fluorinated grease, it is easy to hold the grease on the sliding portion, and the friction coefficient can be improved.

  A non-fluorine base oil and a fluorine base oil that are base oil mixtures used in the present invention are not compatible with each other. That they are not compatible with each other means that a homogeneous base oil mixture cannot be formed when they are simply mixed.

  Non-fluorinated base oils include, for example, poly-α-olefins, ethylene-α-olefin oligomers, polybutenes or their hydrides, synthetic hydrocarbon oils such as alkylbenzene and alkylnaphthalene, polyalkylene glycols, polyphenyl ethers, and alkyl-substituted Ether synthetic oils such as diphenyl ether, aromatic polyvalent carboxylic acid esters such as trimellitic acid ester and pyromellitic acid ester, polyol esters such as neopentyl glycol ester, trimethylolpropane ester, pentaerythritol ester, dipentaerythritol ester, Furthermore, at least a small amount of ester synthetic oils such as aliphatic dibasic acid esters, phosphoric acid esters, phosphite esters, and carbonic acid esters, paraffinic mineral oils, naphthenic mineral oils, or mineral oils obtained by refining them. One, preferably synthetic hydrocarbon oils or ether-based synthetic oil is used.

These non-fluorinated base oils generally have a kinematic viscosity at 40 ° C. (based on JIS K2283 corresponding to ASTM D445) of about 15 to 350 mm ² / sec, preferably about 20 to 300 mm ² / sec. If the kinematic viscosity is lower than this, the durability at high temperature is poor, that is, the amount of evaporation is increased.On the other hand, if the kinematic viscosity is higher than this, the permeability to the gap during sliding deteriorates and the grease is likely to run out. Become.

Fluorine base oils have a kinematic viscosity (according to JIS K2283) at 40 ° C. of about 15 to 350 mm ² / sec, preferably about 20 to 300 mm ² / sec for the same reason as for non-fluorine base oils. Commonly used, more specifically the general formula
RfO (CF ₂ O) _x (C ₂ F ₄ O) _y (C ₃ F ₆ O) _z Rf
Is used. Specifically, for example, those represented by the following general formulas (1) to (4) are used, and those represented by the following general formula (5) are also used. Rf is a perfluoro lower alkyl group having 1 to 5, preferably 1 to 3, carbon atoms such as a perfluoromethyl group, a perfluoroethyl group, and a perfluoropropyl group.
(1) RfO (CF ₂ CF ₂ O) _m (CF ₂ O) _n Rf
Here, m + n = 3 to 200, m: n = 10 to 90:90 to 10 and the CF ₂ CF ₂ O group and the CF ₂ O group are randomly bonded in the main chain. Yes, it can be obtained by completely fluorinating the precursor produced by photo-oxidative polymerization of tetrafluoroethylene.
(2) RfO [CF (CF ₃ ) CF ₂ O)] _m (CF ₂ O) _n Rf
Here, m + n = 3 to 200, m: n = 10 to 90:90 to 10 and the CF (CF ₃ ) CF ₂ O group and the CF ₂ O group are randomly bonded in the main chain. It is obtained by completely fluorinating a precursor produced by photo-oxidative polymerization of hexafluoropropylene.
(3) RfO [CF (CF ₃ ) CF ₂ O] _p (CF ₂ CF ₂ O) _q (CF ₂ O) _r Rf
Where p + q + r = 3 to 200 and q and r can be 0, (q + r) / p = 0 to 2 and also a CF (CF ₃ ) CF ₂ O group, CF ₂ CF _{The 2} O group and the CF ₂ O group are randomly bonded in the main chain, and can be obtained by completely fluorinating a precursor formed by photo-oxidative polymerization of hexafluoropropylene and tetrafluoroethylene.
(4) RfO [CF (CF ₃ ) CF ₂ O] _s (CF ₂ CF ₂ O) _t Rf
Here, s + t = 2 to 200, t can be 0, t / s = 0 to 2, and CF (CF ₃ ) CF ₂ O group and CF ₂ CF ₂ O group are in the main chain Randomly bonded, by completely fluorinating the precursor produced by photo-oxidation polymerization of hexafluoropropylene and tetrafluoroethylene, or in the presence of a cesium fluoride catalyst, It is obtained by anionic polymerization of fluoroethylene oxide and treating the resulting acid fluoride compound having a terminal —CF (CF ₃ ) COF group with fluorine gas.
(5) F (CF ₂ CF ₂ CF ₂ O) _{2 to 100} C ₂ F ₅
This is because 2,2,3,3-tetrafluorooxetane is anionically polymerized in the presence of a cesium fluoride catalyst, and the resulting fluorinated polyether (CH ₂ CF ₂ CF ₂ O) _n is subjected to about UV irradiation. It is obtained by treating with fluorine gas at 160 to 300 ° C.

  These non-fluorinated base oils and fluorinated base oils are generally 1 to 95% by weight, preferably 6 to 89% by weight of the former, and 99 to 5% by weight, preferably 94 to 11% by weight of the latter. Used in proportions. If the mixing ratio of the non-fluorinated base oil is less than this, the load resistance is improved, but the wear resistance, heat resistance, shear stability, etc. are inferior. On the other hand, if the mixing ratio is higher than this, the wear resistance is decreased. However, it is inferior in heat resistance, load resistance and shear stability.

Composite metal soap as a thickener is formed as a complex metal soap of aliphatic dicarboxylic acid and monoamide monocarboxylic acid. The formation of the composite metal soap is performed at the time of preparing the lubricating grease composition as described later.

  As the aliphatic dicarboxylic acid, a saturated or unsaturated dicarboxylic acid having 2 to 20 carbon atoms is used. Examples of the saturated dicarboxylic acid include oxalic acid, malonic acid, succinic acid, methyl succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonamethylene dicarboxylic acid, decamethylene dicarboxylic acid, undecane dicarboxylic acid , Dodecanedicarboxylic acid, tridecanedicarboxylic acid, tetradecanedicarboxylic acid, pentadecanedicarboxylic acid, hexadecanedicarboxylic acid, heptadecanedicarboxylic acid, octadecanedicarboxylic acid, etc., preferably adipic acid, pimelic acid, suberic acid, azelaic acid, sebacin Acid, nonamethylene dicarboxylic acid, decamethylene dicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tridecanedicarboxylic acid, tetradecanedicarboxylic acid, pentadecanedicarboxylic acid, hex Decanedicarboxylic acid, hepta-decane dicarboxylic acid, octadecane dicarboxylic acid, or the like is used. Examples of the unsaturated dicarboxylic acid include maleic acid, fumaric acid, alkenyl succinic acid such as 2-methylene succinic acid, 2-ethylene succinic acid, 2-methylene glutaric acid, and the like. These saturated or unsaturated dicarboxylic acids are used alone or in combination of two or more.

  The monoamide monocarboxylic acid is obtained by amidating the monocarboxyl group of the above dicarboxylic acid. Examples of amines to be amidated include butylamine, amylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, laurylamine. Aliphatic primary amines such as myristylamine, palmitylamine, stearylamine, behenylamine, dipropylamine, diisopropylamine, dibutylamine, diamylamine, dilaurylamine, monomethyllaurylamine, distearylamine, monomethylstearylamine, Aliphatic secondary amines such as dimyristylamine and dipalmitylamine, aliphatic unsaturated amines such as allylamine, diallylamine, oleylamine and dioleylamine, cyclopropylamine Cycloaliphatic amines such as cyclohexane, cyclobutylamine, cyclopentylamine, and cyclohexylamine, and aromatic amines such as aniline, methylaniline, ethylaniline, benzylamine, dibenzylamine, diphenylamine, and α-naphthylamine. Xylamine, heptylamine, octylamine, nonylamine, decylamine, laurylamine, myristylamine, palmitylamine, stearylamine, behenylamine, dibutylamine, diamylamine, monomethyllaurylamine, monomethylstearylamine, oleylamine and the like are used.

In these aliphatic dicarboxylic acids and monoamide monocarboxylic acids , the latter is used in a molar ratio of 0.1 to 10, preferably 0.5 to 5, with respect to the former. If it is used in a mixing ratio other than this, it is not preferable because the dropping point is lowered. Both of these are used by forming a composite metal soap with a metal compound such as lithium, sodium, potassium, calcium, barium, magnesium, copper, iron, cobalt, zinc, aluminum used in the form of hydroxide, oxide, etc. However, it is preferably used as composite barium soap or composite lithium soap. The metal compound used for the preparation of the composite metal soap is used in an amount equivalent to the theoretical amount necessary for the saponification reaction.

  Further, as the fluororesin powder, PTFE powder, HFP powder, perfluoroalkylene resin powder and the like are used. These fluororesin powders generally have an average primary particle size of about 500 μm or less, preferably about 0.1 to 30 μm.

  PTFE (polytetrafluoroethylene) is a process that produces polytetrafluoroethylene by methods such as emulsion polymerization, suspension polymerization, and solution polymerization of tetrafluoroethylene, followed by thermal decomposition, electron beam irradiation decomposition, and physical grinding. The number average molecular weight Mn is about 1000 to 100,000. In the case of HFP powder, the copolymerization reaction of tetrafluoroethylene and hexafluoropropene and the molecular weight reduction treatment are also performed in the same manner as in the case of polytetrafluoroethylene, and the number average molecular weight Mn is about 1000 to 600,000. The grade is used. The molecular weight can also be controlled by using a chain transfer agent during the copolymerization reaction.

  By mixing two types of grease, a grease that is a non-fluorine base oil containing composite metal soap thickener (non-fluorine grease) and a grease that is a fluorine base oil containing fluororesin powder (fluorine grease), The lubricating grease composition of the invention is prepared.

Formation of the composite metal soap and preparation of the lubricating grease composition are performed as follows.
(a-1) A non-fluorinated base oil, aliphatic dicarboxylic acid and monoamide monocarboxylic acid are added to a reaction kettle capable of being heated and stirred. The mixture is heated to about 80 to 180 ° C., which is a temperature that does not cause slag, and stirred, and a metal hydroxide or metal oxide is added thereto to form a composite metal soap in the non-fluorine base oil. After cooling, a predetermined amount of amine-based antioxidant, for example, is blended in a proportion that occupies about 0.1 to 5% by weight in the non-fluorinated base oil, and is kneaded with a three-roll mill or a high-pressure homogenizer. Prepare system grease. Prior to kneading, other non-fluorine base oils other than the first used non-fluorine base oil can be added and used.
(a-2) Fluorine base oil and fluororesin powder are mixed in a mixing kettle and then kneaded using a three-roll mill or a high-pressure homogenizer to prepare a fluorinated grease.
(a-3) These two types of grease are mixed in a mixing kettle and kneaded using a three-roll mill or a high-pressure homogenizer, preferably a three-roll mill, to prepare a lubricating grease composition. In addition, as a three-roll mill used for kneading, a hydraulic type is generally used.

  (b) Fluorine base oil and fluorine resin are added to the non-fluorine grease prepared as described above, mixed in a mixing kettle, and then kneaded with a three-roll mill or a high-pressure homogenizer. Lubricating grease compositions can also be prepared.

  At this time, a grease that is a non-fluorine base oil containing a composite metal soap thickener (non-fluorine grease) has a dropping point corresponding to an upper limit temperature that is established as a grease of 250 ° C. or higher. When a non-fluorine-based grease having a dropping point of less than 250 ° C. is used, there may be a problem that the product reliability is lowered when applied to a reciprocating sliding application at a temperature of 120 to 150 ° C. or higher. The dropping point is measured according to JIS K2220.8 corresponding to ISO 2176.

  In the lubricating grease composition comprising the above essential components, the non-fluorine base oil is used in a proportion of 1 to 90% by weight, preferably 5 to 80% by weight, and in a mixing ratio as described above with the non-fluorine base oil. Fluorine base oil is 5 to 80% by weight, preferably 10 to 80% by weight, composite metal soap is 0.5 to 30% by weight, preferably 1 to 25% by weight, and fluororesin powder is 0.1 to Each is used in a proportion of 20% by weight, preferably 1 to 15% by weight.

  By blending each component at such a ratio, in the case of a non-fluorinated base oil, it is possible to add a thickener that is incompatible or poorly compatible with the fluorinated base oil, thereby improving wear resistance. The friction coefficient can be reduced and the rust prevention and corrosion prevention effects can be improved. In the case of fluorinated base oil, the heat resistance can be improved. In the case of composite metal soap, the wear resistance can be improved. In addition, in the case of the fluororesin powder, the compatibility between the fluorinated base oil and the composite metal soap can be improved.

Additives used in conventional lubricants such as antioxidants, rust inhibitors, corrosion inhibitors, extreme pressure agents, oiliness agents, solid lubricants, etc., are added to the lubricating grease composition as necessary. be able to. Examples of the antioxidant include phenol-based antioxidants such as 2,6-ditert-butyl-4-methylphenol and 4,4′-methylenebis (2,6-ditert-butylphenol), C ₄ -C Amine-based antioxidants such as alkyldiphenylamines having ₂₀ alkyl groups, triphenylamines, phenyl-α-naphthylamines, alkylated phenyl-α-naphthylamines, phenothiazines, alkylated phenothiazines, phosphorous antioxidants, sulfur And system antioxidants.

  Examples of the rust preventive agent include fatty acids, fatty acid metal salts, fatty acid amines, alkyl sulfonic acid metal salts, alkyl sulfonic acid amine salts, oxidized paraffin, polyoxyethylene alkyl ether, and the like. Examples include triazole, benzimidazole, thiadiazole and the like.

  Examples of extreme pressure agents include phosphorous compounds such as phosphate esters, phosphite esters, phosphate ester amine salts, sulfur compounds such as sulfides and disulfides, dialkyldithiophosphate metal salts, and dialkyldithiocarbamic acid metal salts. And sulfur-based compound metal salts, chlorinated paraffin, chlorinated diphenyl and other chlorinated compounds.

  Examples of the oily agent include fatty acids or esters thereof, higher alcohols, polyhydric alcohols or esters thereof, aliphatic esters, aliphatic amines, fatty acid monoglycerides, montan waxes, and amide waxes. Examples of other solid lubricants include molybdenum disulfide, graphite, boron nitride, silane nitride, and melamine cyanurate. These other solid lubricants also have an average primary particle size of 30 μm or less, preferably 0.1 to 20 μm.

  In addition, other thickeners conventionally used as thickeners, such as silica, clay, graphite, zinc oxide, urea compounds, polyethylene, polypropylene, polyamide, organic pigments, metal soaps, etc., may be added as appropriate. It can also be used.

  Next, the present invention will be described with reference to examples.

Reference example 1
A barium composite soap of sebacic acid and sebacic acid monostearylamide occupying 30% by weight in a non-fluorinated grease as a thickener in a poly-α-olefin oil (40 ° C. viscosity: 30 mm ² / sec) as described above After synthesizing by the method (a-1), 2% by weight of an amine-based antioxidant (KING INDUSTRIES product NA-LUBE AO-120; alkyldiphenylamine) was added thereto, and then kneaded twice with a three-roll mill. Grease A was prepared. The dropping point of the obtained grease A was 283 ° C.

Reference example 2
25% by weight in non-fluorine grease as a thickener in poly-α-olefin oil (40 ° C viscosity: 30 mm ² / s and 400 mm ² / s mixed in a 1: 1 weight ratio) A barium complex soap of occupying azelaic acid and azelaic acid monooctylamide was synthesized by the method (a-1) as described above, and 2% by weight of an amine antioxidant (NA-LUBE AO-120) was added thereto. Thereafter, grease B was prepared by kneading twice with a three-roll mill. The dropping point of the obtained grease B was 277 ° C.

Reference example 3
A barium composite soap of azelaic acid and azelaic acid monooctylamide, which occupies 25% by weight in a non-fluorine-based grease as a thickener in an alkylnaphthalene (40 ° C. viscosity: 114 mm ² / sec) as described above (a- After synthesizing in 1), 2% by weight of an amine-based antioxidant (NA-LUBE AO-120) was added thereto, and then kneaded twice with a three-roll mill to prepare Grease C. The dropping point of the obtained grease C was 273 ° C.

Reference example 4
A barium composite soap of sebacic acid and sebacic acid monostearylamide occupying 15% by weight in a non-fluorine-based grease as a thickener in diphenyl ether oil (40 ° C. viscosity: 100 mm ² / sec) as described above (a- After synthesizing in 1), 2% by weight of an amine-based antioxidant (NA-LUBE AO-120) was added thereto, and then kneaded twice with a three-roll mill to prepare Grease D. The resulting grease D had a dropping point of 262 ° C.

Reference Example 5
A barium composite soap of sebacic acid and sebacic acid monostearylamide, which occupies 25% by weight in a non-fluorine-based grease as a thickener in diphenyl ether oil (40 ° C viscosity: 100 mm ² / sec) as described above (a- After synthesizing in 1), 2% by weight of an amine-based antioxidant (NA-LUBE AO-120) was added thereto, and then kneaded twice with a three-roll mill to prepare Grease E. The dropping point of the obtained grease E was 270 ° C.

Reference Example 6
A lithium composite soap of azelaic acid and 12-hydroxystearic acid in poly-α-olefin oil (40 ° C. viscosity: 46 mm ² / sec) and occupying 20% by weight in a non-fluorinated grease as a thickener The grease F was prepared by adding 2% by weight of an amine antioxidant (NA-LUBE AO-120) and then kneading twice with a three-roll mill. . The dropping point of the obtained grease F was 280 ° C.

Reference Example 7
A lithium composite soap of sebacic acid and 12-hydroxystearic acid occupying 20% by weight in a non-fluorine-based grease as a thickener in diphenyl ether oil (40 ° C. viscosity: 100 mm ² / sec) as described above (a- A grease G was prepared by adding 2% by weight of an amine antioxidant (NA-LUBE AO-120) and then kneading twice with a three-roll mill. The dropping point of the obtained grease G was 269 ° C.

Reference Example 8
In poly-α-olefin oil (40 ° C viscosity: 30 mm ² / sec), a lithium soap of 12-hydroxystearic acid, which occupies 10% by weight of the non-fluorinated grease as a thickener, was synthesized, and 2 wt. % Amine-based antioxidant (NA-LUBE AO-120) was added and then kneaded twice with a three-roll mill to prepare Grease H. The dropping point of the obtained grease H was 182 ° C.

Reference Example 9
PTFE powder (average particle size 0.3 μm) in an amount of 18% by weight in a fluorine-based grease in a base oil (40 ° C. viscosity: 230 mm ² / sec) having a molecular structure RfO [CF (CF ₃ ) CF ₂ O] _m Rf ) And kneaded twice with a three-roll mill to prepare Grease I. The resulting grease I had a dropping point of 300 ° C. or higher.

Reference Example 10
PTFE powder (average particle) in an amount of 27% by weight in a fluorine-based grease in a base oil (40 ° C viscosity: 85 mm ² / sec) having a molecular structure RfO (CF ₂ CF ₂ O) _m (CF ₂ O) _n Rf (Grease II) was prepared by kneading twice with a three-roll mill. The dropping point of the obtained grease II was 300 ° C. or higher.

Reference Example 11
PTFE powder in the amount of 15% by weight in PTFE powder (average particle) in base oil (40 ° C viscosity: 85mm ² / sec) with molecular structure RfO (CF ₂ CF ₂ O) _m (CF ₂ O) _n Rf (Grease III) was prepared by kneading twice with a three-roll mill. The dropping point of the obtained grease III was 300 ° C. or higher.

Reference Example 12
PTFE powder (average) occupying 31% by weight in fluorine-based grease in base oil (40 ° C viscosity: 65mm ² / sec) with molecular structure F (CF ₂ CF ₂ CF ₂ O) _2-100 C ₂ F ₅ A particle size of 0.3 μm) was mixed and kneaded twice with a three-roll mill to prepare Grease IV. The dropping point of the obtained grease IV was 300 ° C. or higher.

Examples 1 6 and Comparative Examples 1-7
After mixing one or two of the non-fluorine-based greases A to H and fluorine-based greases I to IV prepared in each of the above reference examples at a predetermined weight ratio, the mixture is sufficiently stirred and mixed in a mixing kettle. A lubricating grease composition was prepared by kneading twice with three rolls.

The prepared lubricating grease composition was measured for the following items.
Evaporation loss (heat resistance): Each sample on an aluminum dish with a diameter of 37 mm and a height of 5 mm
For example, when the specific gravity is 1, it corresponds to 0.3g.
Apply a sample of weight evenly and place it in a constant temperature bath at 150 ° C.
After standing for a period of time, remove from the thermostat and evaporate the sample.
Loss
(The smaller this value, the better)
Oil separation degree (heat resistance): JIS K2220.11 compliant
Measure oil separation after 24 hours at 180 ℃
(The smaller this value, the better)
SRV test (reciprocating test): ASTM D5707 compliant
Specimen 100CR6 cylinder / 100CR6 plate
Test conditions Temperature: Room temperature
Load: 50N
Sliding width: 4mm
Frequency: 10Hz
Test time: 1 hour
Under the above test conditions, the coefficient of friction after the test, during the test
Evaluation of friction coefficient behavior
Regarding the behavior of the coefficient of friction, the test starts 10-60 minutes
Friction coefficient (maximum value)-(minimum value) = fluctuation
Width, coefficient of friction is small and stable
○, the coefficient of friction is large and stable.
No case was rated as x

The measurement results are shown in the following Table 1 (Example) and Table 2 (Comparative Example).
Table 1
Example 1 2 3 4 5 6
[Non-fluorine grease]
A (wt%) 80 − − − − 30
B (wt%) − 50 − − − −
C (wt%) − − 60 − − −
D (wt%) − − − 50 − −
E (wt%) − − − − 10 −
F (wt%) − − − − − −
G (wt%) − − − − − −
H (wt%) − − − − − −
[Fluorine grease]
I (wt%) 20 − − 50 − −
II (wt%) − 50 − − − −
III (wt%) − − − − 90 70
IV (wt%) − − 40 − − −
〔Measurement item〕
Evaporation loss (wt%) 6.5 6.7 2.9 1.7 0.9 1.2
Oil separation (wt%) 1.1 0.9 1.0 1.5 2.0 1.7
SRV test
Friction coefficient after 1 hour 0.179 0.171 0.163 0.175 0.177 0.171
Fluctuation range 0.017 0.028 0.020 0.025 0.023 0.021
Coefficient of friction behavior ○ ○ ○ ○ ○ ○

Table 2
Comparative Example 1 2 3 4 5 6 7
[Non-fluorine grease]
A (wt%) − − 100 − − − −
B (wt%) − − − − − − −
C (wt%) − − − − − − −
D (wt%) − − − − − − −
E (wt%) − − − 3 − − −
F (wt%) 80 − − − − − −
G (wt%) − 70 − − − − −
H (wt%) − − − − 80 − −
[Fluorine grease]
I (wt%) 20 − − − 20 100 −
II (wt%) − − − − − − 100
III (wt%) − − − 97 − − −
IV (wt%) − 30 − − − − −
〔Measurement item〕
Evaporation loss (wt%) 3.2 1.9 14.0 0.6 13.9 1.8 0.4
Oil separation (wt%) 3.0 2.7 2.4 4.5 5.2 5.5 5.0
SRV test
Friction coefficient after 1 hour 0.176 0.165 0.170 0.240 0.130 0.279 0.232
Fluctuation range 0.019 0.017 0.015 0.155 0.025 0.076 0.204
Coefficient of friction behavior ○ ○ ○ × ○ × ×

  The lubricating grease composition according to the present invention is used as a reciprocating sliding lubricating grease, for example, in an actuator part such as a micro switch or an electromagnetically driven valve that is used under a high temperature condition of 120 to 150 ° C. or higher. In addition, it is suitably used for parts such as a guide rail, a slide rail, a piston, and a cam mechanism that act as lubrication grease for reciprocating sliding.

Claims (13)

  Incompatible with non-fluorinated greases and non-fluorinated base oils with a dropping point of 250 ° C or higher, containing a composite metal soap thickener of aliphatic dicarboxylic acid and monoamide monocarboxylic acid in non-fluorinated base oil A lubricating grease composition for reciprocating sliding used for a microswitch or an actuator part of an electromagnetically driven valve comprising a mixture of two types of grease of fluorine-based grease containing fluorine resin powder in a fluorine-based base oil.   The lubricating grease composition for reciprocating sliding according to claim 1, wherein the non-fluorine base oil is a synthetic hydrocarbon oil or an ether synthetic oil. ^{2. The} lubricating grease composition for reciprocating sliding according to claim 1, wherein a non-fluorine base oil and a fluorine base oil having a kinematic viscosity at 40 ° C. of 15 to 350 mm ² / sec are used. ^{2. The} lubricating grease composition for reciprocating sliding according to claim 1, wherein a non-fluorine base oil and a fluorine base oil having a kinematic viscosity at 40 ° C. of ²⁰ to 300 mm ² / sec are used.   The lubricating grease composition for reciprocating sliding according to claim 1, wherein the fluorine base oil is used in a ratio of 99 to 5% by weight with respect to 1 to 95% by weight of the non-fluorine base oil.   The lubricating grease composition for reciprocating sliding according to claim 1, wherein the fluorine base oil is used in a proportion of 94 to 11 wt% with respect to 6 to 89 wt% of the non-fluorine base oil.   It consists of 1 to 90% by weight of non-fluorine base oil, 5 to 80% by weight of fluorine base oil, 0.5 to 30% by weight of composite metal soap and 0.1 to 20% by weight of fluororesin powder, and the total of these is 100% by weight The lubricating grease composition for reciprocating sliding according to claim 5.   It consists of 5 to 80% by weight of non-fluorinated base oil, 10 to 80% by weight of fluorinated base oil, 1 to 25% by weight of composite metal soap and 1 to 15% by weight of fluororesin powder, and the total of these is 100% by weight The lubricating grease composition for reciprocating sliding according to claim 6.   2. The lubricating grease composition for reciprocating sliding according to claim 1, wherein the composite metal soap is barium composite soap or lithium composite soap. Non-fluorinated base oil, aliphatic dicarboxylic acid and monoamide monocarboxylic acid prepared by heating and stirring and adding metal hydroxide thereto to form composite metal soap in non-fluorinated base oil 2. The method for producing a lubricating grease composition for reciprocating sliding according to claim 1, wherein the grease is kneaded with a fluorine-based grease prepared from a fluorine-based base oil and a fluorine resin powder. The method for producing a lubricating grease composition for reciprocating sliding according to claim 10, wherein the non-fluorinated grease and the fluorinated grease are kneaded using a three-roll mill or a high-pressure homogenizer. The method for producing a lubricating grease composition for reciprocating sliding according to claim 10, wherein a synthetic hydrocarbon oil or an ether type synthetic oil is used as the non-fluorine base oil. The method for producing a lubricating grease composition for reciprocating sliding according to claim 10, wherein barium hydroxide or lithium hydroxide is used as the metal hydroxide.