JP2017020008A - Non-flame spread grease composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grease composition excellent in non-flame spread properties, exhibiting satisfactory lubricity and further capable of further reducing the risk of fire.SOLUTION: Provided is a grease composition containing base oil and a thickener, and non-flame spread properties. The base oil is made only of synthetic oil, and at least includes complex ester, and the content of the complex ester lies in the range of more than 5 mass% to below 55 mass%, where the base oil is preferably composed of a mixture of the complex ester and polyalphaolefin, e.g., whose 40°C kinematic viscosity is 400 mm/s. Further, as the complex ester composing the base oil, the one obtained by bringing neopentyl glycol, dimer acid and 2-ethylhexyl alcohol into ester reaction can be used. Further, as a solid lubricant, graphite or calcium carbonate can be incorporated therein.SELECTED DRAWING: None

Description

  The present invention relates to a grease composition having non-flammability.

  The grease composition is a mixture of a base oil and a metal soap such as lithium soap as a thickener, and is generally used widely.

  With recent advances in mechanical technology such as industrial machinery, electrical equipment, and automobiles, various equipment has been downsized, increased in output, and improved in durability such as heat resistance. Measures against high temperature during equipment operation, such as rising and operation of equipment in a high temperature atmosphere, are required.

  In connection with this, it is requested | required that the grease used for various apparatuses is more suitable by the use under high temperature.

  Among them, grease used for industrial machines in particular is required to be difficult to burn from the viewpoint of preventing fires when used at high temperatures, and is difficult to spread even if burned, that is, spread High safety is required.

  Until now, various grease compositions excellent in flame retardancy have been proposed (see, for example, Patent Documents 1 and 2). However, the usage environment of equipment is becoming more and more severe, and it is desired to have higher safety such as suppressing the occurrence of fire and the like and to obtain further lubricity.

JP 2004-67843 A JP 2011-105828 A

  The present invention has been proposed in view of the above-described circumstances, and provides a grease composition that exhibits excellent lubricity and that can further reduce the risk of fire and that is excellent in non-flammability. For the purpose.

  The inventors of the present invention have made extensive studies in order to solve the above-described problems. As a result, it was found that the grease composition was composed of only a synthetic oil and was composed of a base oil containing at least a complex ester, thereby achieving excellent non-flammability and completing the present invention. It came. That is, the present invention provides the following.

  (1) A first invention of the present invention is a grease containing a base oil and a thickener and having non-flammability, wherein the base oil consists only of synthetic oil and contains at least a complex ester. The complex ester content is in the range of more than 5% by mass and less than 55% by mass.

  (2) According to a second aspect of the present invention, in the first aspect, the base oil is composed of a mixture of the complex ester and a polyalphaolefin. It is.

(3) A third invention of the present invention is the non-fire-spreading grease composition according to the second invention, wherein the polyalphaolefin has a kinematic viscosity at 40 ° C. of 400 mm ² / s or more.

  (4) According to a fourth aspect of the present invention, in any one of the first to third aspects, the complex ester constituting the base oil is an ester of neopentyl glycol, dimer acid, and 2-ethylhexyl alcohol. A non-flammable grease composition characterized by being obtained by a chemical reaction.

  (5) A fifth invention of the present invention is characterized in that in any one of the first to fourth inventions, a solid lubricant is contained as an additive, and the solid lubricant is graphite or calcium carbonate. This is a non-flammable grease composition.

  (6) A sixth invention of the present invention is the non-flammable grease composition according to any one of the first to fifth inventions, which comprises a phenolic antioxidant as an additive.

  (7) A seventh invention of the present invention is the non-flammable grease composition according to any one of the first to sixth inventions, wherein the thickener is lithium composite soap.

  ADVANTAGE OF THE INVENTION According to this invention, while showing favorable lubricity, the grease composition excellent in the non-fire spread property which can reduce the risk of a fire more can be provided.

  Hereinafter, a specific embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, A various change is possible in the range which does not change the summary of this invention. In this specification, the notation “X to Y” (X and Y are arbitrary numerical values) means “X or more and Y or less”.

<< 1. Non-flammable grease composition >>
The grease composition according to the present embodiment includes a base oil and a thickener, and has a non-flammability grease composition (hereinafter referred to as “non-flammability grease composition” or simply “grease”). Also referred to as a “composition”. Here, “non-flammability” refers to a property that does not ignite or can suppress the spread of the flame even when ignited. Specifically, for non-flammability, the fire spread distance at the time of extinguishing the fire is brought into contact with a heated object such as a steel ball heated to a high temperature, as in the examples described later. It can be evaluated by measuring in the vertical direction and the horizontal direction.

  Specifically, the non-flammable grease composition according to the present embodiment includes only synthetic oil as a base oil, and the base oil includes at least a complex ester, and the content of the complex ester exceeds 5% by mass. It is characterized by being in a range of less than 55% by mass. Thus, it is composed of a base oil consisting only of synthetic oil, including at least a complex ester, and is a grease composition in which the content of the complex ester is within a specific range, while exhibiting good lubricating performance Excellent fire spreadability can be achieved. This will be specifically described below.

[Base oil]
The base oil is the main component of the grease composition. In the non-flammable grease composition according to the present embodiment, the base oil consists only of synthetic oil. That is, it does not contain mineral oil. Here, “synthetic oil” is a chemically synthesized oil, while “mineral oil” is an oil obtained by separation, distillation and purification from natural crude oil.

  The non-flammable grease composition is characterized in that it contains at least a complex ester as the base oil.

  In the non-fire-spreading grease composition, the base oil is more preferably composed of a mixture of a complex ester and a polyalphaolefin. Thus, by using a mixed base oil of complex ester and polyalphaolefin, a grease composition can be efficiently prepared, and excellent non-flammability can be exhibited.

(Complex ester)
The complex ester is an ester synthesized using, for example, a monohydric alcohol, a polyhydric alcohol, and a polybasic acid as raw materials. In the present embodiment, the complex ester is not particularly limited, but an aliphatic monohydric alcohol and an aliphatic polyhydric alcohol, a linear or branched aliphatic monocarboxylic acid, a linear or branched fat. A complex ester composed of an aromatic dibasic acid or aromatic dibasic acid, tribasic acid, or tetrabasic acid can be preferably used.

  Specifically, the monohydric alcohol is not particularly limited, but those having 1 to 24 carbon atoms, preferably those having 6 to 12 carbon atoms, and more preferably those having 8 to 10 carbon atoms are used. Such monohydric alcohols may be linear or branched, and may be saturated or unsaturated. Examples of the alcohol having 1 to 24 carbon atoms include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol. , Heptadecanol, octadecanol, nonadecanol, icosanol, heicosanol, tricosanol, tetracosanol, and mixtures thereof. Among these, a monohydric alcohol having a branch in 8 to 10 hydrocarbon groups is particularly preferable.

  Further, the polyhydric alcohol is not particularly limited, but those having 2 to 10 valences, preferably 2 to 6 valences are used. For example, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-propanediol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 2- Methyl-1,2-propanediol, 2-methyl-1,3-propanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, neopentyl Dihydric alcohols such as glycol; glycerin, polyglycerin (eg, diglycerin, triglycerin, tetraglycerin, etc.), trimethylol alkane (trimethylolethane, trimethylolpropane, trimethylolbutane, etc.), pentaerythritol 1,2,4-butanetriol, 1,3,5-pentanetriol, 1,2,6-hexanetriol, 1,2,3,4-butanetetrol, sorbitol, sorbitan, sorbitol glycerol condensate, Polyhydric alcohols such as adonitol, arabitol, xylitol, mannitol; sugars such as xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, and the like. Among these, neopentyl glycol, trimethylol ethane, trimethylol propane, pentaerythritol, and a mixture thereof are more preferable from the viewpoint of obtaining higher thermal stability.

  The polybasic acid is not particularly limited. For example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, dodecane-1,12-dicarboxylic acid, and plasylic acid And dibasic acids such as dimer acid, phthalic acid, isophthalic acid and terephthalic acid. Among them, dimer acid having 2 to 40 carbon atoms is preferable, and dimer acid having 36 carbon atoms is more preferable.

  In addition, as a polybasic acid, it is not restricted to the dibasic acid mentioned above, A tribasic acid, a tetrabasic acid, etc. may be sufficient. Further, the complex ester may include a monobasic acid, and for example, a fatty acid having 2 to 24 carbon atoms is used as the monobasic acid.

  As the esterification reaction using the above-described raw materials, for example, alcohol and polybasic acid may be reacted at a predetermined ratio.

  Further, it may be a complete ester in which all the hydroxyl groups or polybasic acid carboxyl groups in the polyhydric alcohol are esterified, or a partial ester in which a hydroxyl group or a part of the carboxyl group is not esterified and remains as a hydroxyl group or a carboxyl group. Good.

  The content of the complex ester is in the range of more than 5% by mass and less than 55% by mass with respect to the total amount of the grease composition. Moreover, Preferably it is the range of 10 to 50 mass%, More preferably, it is the range of about 15 to 45 mass%. When the content of the complex ester in the composition is 5% by mass or less, the effect of non-fire spread cannot be sufficiently obtained. On the other hand, if the content is 55% by mass or more, the effect of non-flammability is reduced, and the grease composition may not be produced efficiently.

  As will be described later, when a mixed base oil of a complex ester and a polyalphaolefin is used, the content of the base oil in the grease composition may be determined in consideration of the content of the polyalphaolefin. preferable.

(Polyalphaolefin)
As described above, the non-flammable grease composition according to the present embodiment includes at least a complex ester as a base oil, and the base oil includes, in particular, a mixed base oil of a complex ester and a polyalphaolefin. It is more preferable that

  Polyalphaolefin is a polymer of alpha olefin. The number of carbon atoms of the alpha olefin monomer is preferably about 6 to 20 carbon atoms, more preferably about 8 to 16 carbon atoms, more preferably about 10 to 14 carbon atoms from the viewpoint of viscosity index and evaporability. More preferred. Moreover, as a poly alpha olefin, the thing from the dimer-pentamer of alpha olefin is preferable from a viewpoint of low evaporation property and energy saving. The number of carbon atoms, the compounding ratio, and the degree of polymerization can be adjusted according to the intended properties.

As the polymerization catalyst for the alpha olefin, a metallocene catalyst, an AlCl ₃ catalyst, a Ziegler type catalyst, or the like can be used, and it is particularly preferable to polymerize with a metallocene catalyst. Polyalphaolefins polymerized using a metallocene catalyst are inexpensive and have a low molecular weight component and a narrow molecular weight distribution. Therefore, it is difficult to ignite.

  In addition, as a metallocene catalyst, the well-known thing which combined the metallocene complex can be used, for example. As the metallocene complex, for example, a complex having a conjugated carbon 5-membered ring containing titanium, zirconium, hafnium, or the like can be used.

The polyalphaolefin is not particularly limited, but preferably has a kinematic viscosity at 40 ° C. of 400 mm ² / s or more. Composing the base oil with polyalphaolefin having a kinematic viscosity at 40 ° C of 400 mm ² / s or more improves the flame retardancy of the non-flammable grease composition and effectively suppresses the spread of the flame even when ignited. As a result, good non-flammability is exhibited. By polymerizing using a metallocene catalyst to synthesize a polyalphaolefin, the kinematic viscosity at 40 ° C. can be more efficiently 400 mm ² / s or more. In addition, the 40 degreeC kinematic viscosity is less than 400 mm < ² > / s, and the effect of non-flammability may fall.

  The content of the polyalphaolefin constituting the mixed base oil is not particularly limited and may be determined in consideration of the content of the complex ester. For example, the content of the polyalphaolefin is 20% by mass to the total amount of the grease composition. The range may be about 50% by mass, and more preferably about 30% to 40% by mass. If the polyalphaolefin content is too small, there is a possibility that the grease composition cannot be produced efficiently. On the other hand, when the content is too large, the content of the complex ester is relatively small, and the effect of non-fire spread may not be sufficiently obtained.

(Mixing ratio of polyalphaolefin and complex ester)
As described above, when a mixed base oil of a complex ester and a polyalphaolefin is used as the base oil, the mixing ratio is not particularly limited, but complex ester: polyalphaolefin = 30: 70 to 70: by mass ratio. 30 is preferable, 40:60 to 60:40 is preferable, and 50:50 is more preferable.

  Regarding the mixing ratio, if the ratio of the complex ester is too small, the effect of non-flammability of the grease composition may not be sufficiently obtained. On the other hand, if the ratio of the complex ester is too large, the grease is prepared. It may react with the added water to cause hydrolysis, and the grease composition may not be obtained efficiently.

(Base oil content)
In addition, although it does not specifically limit as content of the base oil in a grease composition, It can be set as the ratio of about 60 mass%-95 mass% in a grease composition. The content of the base oil can be arbitrarily determined in consideration of the content of the thickener added to obtain a desired grease hardness.

[Thickener]
The thickener is a component that constitutes a grease base together with the above-described base oil and retains the oil, and those conventionally used in general can be used.

  Specifically, thickeners can be broadly classified into soap and non-soap systems. Examples of the soap system include lithium soap, lithium composite soap, calcium soap, calcium composite soap, aluminum soap, and aluminum composite soap. Moreover, as a non-soap system, a urea compound, an organic bentonite, a silica etc. are mentioned, for example. Among these, it is particularly preferable to use lithium composite soap. In addition, these thickeners can be used alone or in combination of two or more.

  The content of the thickener is not particularly limited, and may be blended so as to achieve a desired grease hardness together with the base oil, and can be arbitrarily determined in relation to the base oil. For example, the base oil ratio can be reduced to increase the grease hardness, while the base oil ratio can be increased to increase the grease hardness.

[Solid lubricant]
The non-flammable grease composition according to the present embodiment can contain a solid lubricant as an additive. Thus, by including a solid lubricant, it is possible to obtain a grease composition having non-flammability while exhibiting excellent lubricity such as load resistance.

  Although it does not specifically limit as a solid lubricant, A graphite or calcium carbonate is preferable at the point which is excellent in a flame retardance and self-digestibility. These solid lubricants may be used alone or in combination of two or more.

  As the solid lubricant, in addition to the above-mentioned graphite and calcium carbonate, it is possible to use molybdenum disulfide, PTFE (polytetrafluoroethylene), boron nitride, melamine cyanurate, tungsten disulfide, etc. For example, when molybdenum disulfide or the like is used, there is a possibility that the time from the ignition of the grease to the digestion becomes slightly longer. Therefore, when these solid lubricants are used, it is preferable to adjust the content in combination with a solid lubricant such as calcium carbonate or graphite.

  It does not specifically limit as content of a solid lubricant, It can be set as content according to the required lubricity. Specifically, it can be in the range of about 0.1% by mass to 10% by mass relative to the total amount of the grease composition, and more preferably in the range of about 1% by mass to 5% by mass. If the content of the solid lubricant is less than 0.1% by mass, the effect of improving the lubricity of the grease composition cannot be sufficiently obtained. On the other hand, if the content exceeds 10% by mass, the grease pumpability May be disturbed.

[Phenolic antioxidant]
Moreover, the non-flammable grease composition according to the present embodiment can contain a phenolic antioxidant as an additive. A phenolic antioxidant is a component having excellent flame retardancy. Although the mechanism is not clear, a more excellent non-flammability can be exhibited by adding a phenolic antioxidant.

  It does not specifically limit as a phenolic antioxidant, A well-known thing can be used. Specifically, for example, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxy) Phenyl) propionate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, ethylenebis (oxyethylene) bis [3- (5- tert-butyl-4-hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,6-di-tert-butyl- 4-methylphenol, 2,2'-methylenebis (4-methyl-6-tert-butylphenol) 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [2- (3- (3-tert-butyl-4-hydroxy-5-methylphenyl) -propionyloxy) -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro (5,5) undecane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) Examples include butane. Among these, hexamethylene bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] is particularly preferable.

  Although it does not specifically limit as content of a phenolic antioxidant, It is preferable to set it as the range of 0.1 mass%-5 mass% with respect to the grease composition whole quantity, and the range of 1 mass%-4 mass%. More preferably. When the content of the phenolic antioxidant is in the range of 0.1% by mass to 5% by mass, the effect of improving the non-flammability can be sufficiently exhibited.

[Other additives]
In the grease composition according to the present embodiment, in addition to the above-described components, various additives generally used in grease can be further blended within a range that does not hinder the non-flammability effect. Specifically, antioxidants other than phenolic antioxidants, rust inhibitors, oily agents, extreme pressure agents, antiwear agents, metal deactivators, polymers, metal detergents, non-metal detergents, coloring Agents, water repellents and the like.

  For example, examples of the antioxidant include p, p′-dioctyldiphenylamine, N-phenyl-α-naphthylamine, phenothiazine and the like. Examples of the rust inhibitor include oxidized paraffin, carboxylic acid metal salt, sulfonic acid metal salt, carboxylic acid ester, sulfonic acid ester, salicylic acid ester, succinic acid ester, sorbitan ester, and various amine salts. Oil-based agents, extreme pressure agents, and antiwear agents include zinc sulfide dialkyldithiophosphate, zinc sulfide diallyldithiophosphate, zinc sulfide dialkyldithiocarbamate, zinc sulfide diallyldithiocarbamate, sulfurized dialkyldithiophosphate molybdenum, sulfide diallyldithiophosphate molybdenum. , Sulfurized dialkyldithiocarbamate molybdate, diallyldithiocarbamate molybdate, organic molybdate complex, sulfurized olefin, triphenyl phosphate, triphenyl phosphorothioate, tricresin phosphate, other phosphate esters, sulfurized oils and fats, etc. .

  Examples of the metal deactivator include N, N′disalicylidene-1,2-diaminopropane, benzotriazole, benzimidazole, benzothiazole, thiadiazole and the like. Examples of the polymer include polybutene, polyisobutene, polyisobutylene, polyisoprene, and polymethacrylate. Examples of the metal detergent include metal sulfonate, metal salicylate, and metal finate. Moreover, a succinimide etc. are mentioned as a nonmetallic detergent.

  The content of these optional additives is not particularly limited, but can be contained at a ratio of about 0.1% by mass to 5% by mass with respect to the total amount of the grease composition.

≪2. Method for producing non-flammable grease composition >>
The non-fire-spreading grease composition according to the present embodiment contains a base oil composed only of synthetic oil and a thickener, and specifically includes at least a complex ester as the base oil.

  Although it does not specifically limit as a manufacturing method of such a grease composition, For example, complex ester as a base oil and a thickener are mixed in a copper kettle, and it is 1 hour at the temperature of about 100 to 300 degreeC. A grease composition can be obtained by stirring for 24 hours by heating and stirring, followed by further mixing and stirring with a solid lubricant, antioxidant, and other optional additives, followed by cooling. it can.

  When the base oil is a mixed base oil of complex ester and polyalphaolefin, firstly, the polyalphaolefin is subjected to primary and secondary saponification reactions using fatty acids and alkalis. The grease composition can be produced by mixing the complex ester with water removed, heating at a temperature of about 100 ° C. to 300 ° C. for 1 to 24 hours, and then cooling. Furthermore, other optional additives can be added and mixed thereafter.

  The stirring and kneading treatment can be performed using a known kneading treatment apparatus such as a three-roll mill, a universal stirrer, a homogenizer, or a colloid mill.

≪3. Examples >>
EXAMPLES Hereinafter, although the Example of this invention is shown and demonstrated in detail, this invention is not limited to a following example at all.

[Production of grease composition]
In Examples and Comparative Examples, grease compositions were produced so as to have the compositions shown in Table 1 below, and evaluated for non-flammability and the like.

  Specifically, each component raw material (unit: mass%) shown in Table 1 below is weighed and mixed, and then rotated and rotated at 1000 rpm × 1 minute using a rotating and revolving mixer (Nentaro Awatake), and revolved at 2000 rpm × 1. The mixture was stirred for 3 minutes, defoamed and then kneaded with a three-roll mill (2 passes).

Of the component raw materials of the grease composition, the following were used as the base grease, synthetic oil (base oil), and antioxidant.
<Base grease>
・ Lithium composite soap grease Grease containing metallocene PAO as base oil and lithium composite soap as thickener <Synthetic oil (base oil)>
Polyalphaolefin: metallocene PAO (40 ° C. kinematic viscosity: 400 mm ² / s)
Polymerized polyalphaolefin complex ester using metallocene catalyst:
A product obtained by esterification of neopentyl glycol, dimer acid and 2-ethylhexyl alcohol <Phenolic antioxidant>
Hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]

[Evaluation of non-flammability]
(Non-flammability test)
Evaluation of non-fire spreadability was made by 3/4 inch JIS ball bearing steel balls in which 10 g of the prepared grease composition was uniformly packed in a circular tin plate (depth 7 mm) of φ85 mm and heated to 900 ° C. in an electric furnace. Was put in the center and the fire spread distance at the time of extinguishing the fire was measured in the vertical direction and the horizontal direction, and the average value (mm) was obtained.

(Evaluation of non-flammability)
Based on the results of the non-fire spread test described above, in the evaluation column of Table 1 below, the case where the non-fire spreadability is excellent is indicated as “O”, and the case where there is no non-fire spreadability (not sufficient) is indicated as “X”. The grease compositions prepared in Examples and Comparative Examples were evaluated.

(Combustion test)
As in the non-flammability test, the combustion test was a 3/4 inch JIS ball bearing in which 20 g of the prepared grease composition was uniformly packed in a tin plate of φ67 mm × depth 11 mm and heated to 900 ° C. in an electric furnace. A steel ball was put in the center and the time (seconds) until extinguishing the fire was measured.

[Evaluation of lubricity]
As an evaluation of lubricity, a load resistance test was performed. As a load resistance test, a shell-type four-ball test was performed based on a method defined by ASTM D 2596, and a fusion load (WL, N) was measured. In the evaluation column of Table 1 below, from the measurement results of the fusion load, those with good load resistance were indicated as “◯”, and those with a slightly lower load resistance were indicated as “△”. . In this load resistance test, it can be said that the load resistance is particularly good practically when the fusion load is 2452 N or more. As shown in Table 1, all the grease compositions tested in this example (Examples and Comparative Examples) exhibited excellent lubricity.

  As shown in the results of Examples 1 to 6 in Table 1, the base oil consists only of synthetic oil, and is a grease composition containing a complex ester in a specific range ratio, so that excellent non-flammability is obtained. I understood that I played. Moreover, the result of the combustion test was also good, and it had flame retardancy. Furthermore, the lubricity was also good.

  In contrast, the grease compositions of Comparative Examples 1 and 2 had good lubricity, but did not contain complex ester, and therefore spread to the edge of the tin plate used in the test. It was confirmed that there was a tendency to expand. These grease compositions contain a trimellitic acid ester having flame retardancy, but the time until extinguishing after combustion became longer and resulted. Further, in the grease compositions of Comparative Examples 3 and 4, although the complex ester was contained at a predetermined ratio, the fire spread tended to expand, and the time until fire extinguishing after combustion also became longer.

  From these results, it is a grease composition which consists only of synthetic oil as a base oil and contains a complex ester as the synthetic oil, and the content of the complex ester is in the range of more than 5% by mass and less than 55% by mass. As a result, it has been found that the grease composition exhibits good lubricity, is excellent in non-flame spreadability, and can further reduce the risk of fire even in an environment exposed to high temperatures.

Claims (7)

A grease containing a base oil and a thickening agent and having non-fire spreadability,
The base oil consists only of synthetic oil and includes at least a complex ester,
The non-flammable grease composition, wherein the complex ester content is in the range of more than 5% by mass and less than 55% by mass. The non-flammable grease composition according to claim 1, wherein the base oil is composed of a mixture of the complex ester and polyalphaolefin. The non-fire-spreading grease composition according to claim 2, wherein the polyalphaolefin has a kinematic viscosity at 40 ° C. of 400 mm ² / s or more. The complex ester constituting the base oil is obtained by esterification of neopentyl glycol, dimer acid, and 2-ethylhexyl alcohol. 4. A non-flammable grease composition as described in the paragraph. Contains a solid lubricant as an additive,
The non-flammable grease composition according to any one of claims 1 to 4, wherein the solid lubricant is graphite or calcium carbonate. The non-flammable grease composition according to any one of claims 1 to 5, further comprising a phenol-based antioxidant as an additive. The non-flammable grease composition according to any one of claims 1 to 6, wherein the thickener is lithium composite soap.