JP6169855B2 - Coolant composition and method for operating internal combustion engine using the same - Google Patents

Description

  The present invention relates to a coolant composition capable of improving the fuel efficiency of an internal combustion engine and a method for operating an internal combustion engine using the same.

  Various coolants for cooling automobile engines and the like are known, and among them, water is preferable because it has the highest cooling performance as an engine coolant. However, fresh water freezes when it falls below 0 ° C. Under these circumstances, for the purpose of antifreezing, it is diluted with water so as to obtain a necessary freezing temperature based on glycols such as ethylene glycol, and if necessary, metals, rubbers, resins, etc. used for engines, radiators, etc. Coolant compositions containing various additives for protecting the deterioration of the liquid have been used.

  However, when glycols such as ethylene glycol are used, there is a problem that the viscosity of the cooling liquid composition is remarkably increased particularly at a low temperature. Therefore, in the conventional technique for improving viscosity characteristics, generally, viscosity reduction has been performed for improving fluidity at low temperatures (Patent Documents 1-3).

  However, when the viscosity is reduced, the boundary layer between the coolant and the bore wall becomes thinner and convection is likely to occur, so that the coolant tends to take heat away from the bore wall, resulting in increased cooling loss. However, a new problem has arisen that causes a deterioration in fuel consumption. On the other hand, if the viscosity of the coolant at low temperatures is increased by increasing the concentration of glycols such as ethylene glycol in order to reduce the heat dissipation and reduce the cooling loss, the cooling capacity becomes insufficient at high temperatures, leading to overheating. The problem that occurred.

  For example, Patent Documents 4-6 describe a technique for improving the viscosity characteristics of a lubricating oil by blending a viscosity index improver. However, the viscosity index improver described therein exhibits fluidity at low temperatures. It is formulated for the purpose of reducing the decrease in viscosity at high temperatures while maintaining it.Therefore, even when a liquid agent containing such a viscosity index improver is used as a cooling liquid, the cooling loss at low temperature is reduced, In addition, the cooling capacity at high temperatures cannot be maintained.

JP-A-8-183950 JP 2010-236064 A Japanese Patent Laid-Open No. 9-227859 JP 2011-137089 A JP 2011-132285 A JP 2011-121991 A

  It is an object of the present invention to provide a coolant composition that can improve the fuel efficiency of an internal combustion engine and a method for operating an internal combustion engine using the same. Specifically, an object of the present invention is to provide a cooling liquid composition that can reduce cooling loss at low temperatures and maintain cooling capacity at high temperatures, and an operating method of an internal combustion engine using the same.

  The inventors have added a specific cellulose derivative as a viscosity property improver to make the kinematic viscosity of the coolant composition within a specific range, thereby reducing cooling loss at low temperatures and cooling capability at high temperatures. It has been found that the fuel efficiency of the internal combustion engine is greatly improved.

［式中、
Ｒ_１、Ｒ_２及びＲ_３は、−(ＣＨ_２ＣＨ_２Ｏ)_ｎ−Ｈ、−ＣＨ_２ＣＯＯＸ、式(２)：

で表される基、式(３)：

で表される基及び水素原子からなる群から独立して選択され、ここで、ｎは１〜３の整数であり、Ｘはナトリウム又はカリウムであり、
ただし、Ｒ_１、Ｒ_２及びＲ_３のすべてが水素原子となることはない。]
で表される繰り返し単位からなる化合物であり、分子量が５万〜１６０万である、上記(１)に記載の冷却液組成物。
(３)セルロース誘導体を、組成物１００質量部に対して、０．０５〜１．２質量部含有する、上記(１)又は(２)に記載の冷却液組成物。
(４)上記(１)〜(３)のいずれかの冷却液組成物を内燃機関の冷却液として用いる、内燃機関の運転方法。 That is, the present invention includes the following inventions.
(1) Contains a cellulose derivative as a viscosity property improver and a base,
The cellulose derivative is water soluble and does not thermally gel at 100 ° C.
The base contains at least one alcohol selected from the group consisting of monohydric alcohols, dihydric alcohols, trihydric alcohols and glycol monoalkyl ethers and / or water;
A coolant composition having a kinematic viscosity of 8.5 mm ² / sec or more at 25 ° C. and 2.0 mm ² / sec or less at 100 ° C.
(2) The cellulose derivative has the formula (1):

[Where:
R ₁ , R ₂ and R ₃ are — (CH ₂ CH ₂ O) _n —H, —CH ₂ COOX, Formula (2):

A group represented by formula (3):

Independently selected from the group consisting of a group represented by: and a hydrogen atom, wherein n is an integer from 1 to 3, X is sodium or potassium,
However, not all of R ₁ , R ₂ and R ₃ are hydrogen atoms. ]
The coolant composition according to (1) above, which is a compound composed of a repeating unit represented by the formula (1) and has a molecular weight of 50,000 to 1,600,000.
(3) The coolant composition according to (1) or (2) above, containing 0.05 to 1.2 parts by mass of the cellulose derivative with respect to 100 parts by mass of the composition.
(4) A method for operating an internal combustion engine, wherein the coolant composition according to any one of (1) to (3) is used as a coolant for the internal combustion engine.

  According to the coolant composition of the present invention, the fuel efficiency effect of the internal combustion engine can be improved.

FIG. 1 is a schematic diagram of a warm-up performance and cooling performance evaluation apparatus used in the examples.

  Hereinafter, the present invention will be described in more detail.

  The coolant composition of the present invention contains a specific cellulose derivative as a viscosity property improver, and thereby has a specific kinematic viscosity at low temperatures and high temperatures. In the present invention, low temperature means 25 ° C., and high temperature means 100 ° C.

  The cellulose derivative used in the present invention is not particularly limited as long as it is water-soluble and does not gel at 100 ° C. Here, “water-soluble” means that when 0.1 g of a cellulose derivative is added to 100 ml of water, the mixture is heated to 80 ° C., then stirred for 60 minutes, and stirred and cooled to 25 ° C. It means having no insoluble matter. Further, “thermal gelation” refers to gelation by heating. Examples of the cellulose derivative used in the present invention include those having a property that linear molecules are entangled with each other by hydrogen bonds at a low temperature, and the hydrogen bonds are broken at a high temperature to disperse individual molecules.

［式中、
Ｒ_１、Ｒ_２及びＲ_３は、−(ＣＨ_２ＣＨ_２Ｏ)_ｎ−Ｈ、−ＣＨ_２ＣＯＯＸ、式(２)：

で表される基、式(３)：

で表される基及び水素原子からなる群から独立して選択され、ここで、ｎは１〜３の整数であり、Ｘはナトリウム又はカリウムであり、
ただし、Ｒ_１、Ｒ_２及びＲ_３のすべてが水素原子となることはない。]
で表される繰り返し単位からなる化合物であることが好ましい。 The cellulose derivative is represented by the following formula (1):

[Where:
R ₁ , R ₂ and R ₃ are — (CH ₂ CH ₂ O) _n —H, —CH ₂ COOX, Formula (2):

A group represented by formula (3):

Independently selected from the group consisting of a group represented by: and a hydrogen atom, wherein n is an integer from 1 to 3, X is sodium or potassium,
However, not all of R ₁ , R ₂ and R ₃ are hydrogen atoms. ]
It is preferable that it is a compound which consists of a repeating unit represented by these.

Specific examples of the cellulose derivative include at least one selected from hydroxyethyl cellulose, carboxymethyl cellulose salt and cationized cellulose. Among these, it is preferable to use hydroxyethyl cellulose from the viewpoint of availability. As hydroxyethyl cellulose, in particular, in formula (1), R ₁ , R ₂ and R ₃ are independently selected from — (CH ₂ CH ₂ O) _n —H and a hydrogen atom, where n is 1 to 1 Examples thereof include compounds in which R is an integer of ₃ , and all of R ₁ , R ₂ and R ₃ are not hydrogen atoms. Examples of the carboxymethyl cellulose salt include compounds in which, in formula (1), R ₁ and R ₂ are hydrogen atoms and R ₃ is —CH ₂ COOX, where X is sodium or potassium. As the cationized cellulose, in particular, in formula (1), R ₁ and R ₂ are hydrogen atoms, R ₃ is a group represented by formula (2), or a group represented by (3), Here, the compound whose n is an integer of 1-3 is mentioned.

  The molecular weight of the cellulose derivative is preferably from 50,000 to 1,600,000, particularly preferably from 500,000 to 1,560,000, from the viewpoint of obtaining a thickening effect and good solubility in the base.

  In the cooling liquid composition of the present invention, the blending amount of the cellulose derivative is not particularly limited as long as the kinematic viscosity of the cooling liquid composition at a low temperature and a high temperature can be within the predetermined range. It is preferable that it is 0.05-1.2 with respect to 100 mass parts, it is especially preferable that it is 0.07-1 mass part, and it is still more preferable that it is 0.08-0.5 mass part. Further, when a cellulose derivative having a relatively large molecular weight, for example, a molecular weight of 500,000 to 1,600,000 is used, the blending amount is 0.07 to 0.5 parts by mass with respect to 100 parts by mass of the composition. It is preferable that When the cellulose derivative having a relatively small molecular weight, for example, a molecular weight of 50,000 to 500,000 is used, the blending amount is 0.5 to 1.0 part by mass with respect to 100 parts by mass of the composition. It is preferable. In the coolant composition of the present invention, the above various viscosity characteristic improvers can be used in combination.

The coolant composition of the present invention has a kinematic viscosity of 8.5 mm ² / sec or more at 25 ° C. and 2.0 mm ² / sec or less at 100 ° C.

The coolant composition of the present invention has a kinematic viscosity at 25 ° C. of 8.5 mm ² / sec or more, preferably 8.5 to 3000 mm ² / sec, particularly preferably 10 to 2000 mm ² / sec, and particularly preferably 17. Since it is as high as 5 to 1000 mm ² / sec, the heat dissipation at low temperatures is low and the cooling loss is low. When the kinematic viscosity at 25 ° C. is 3000 mm ² / sec or less, the coolant composition of the present invention is preferable in that it can avoid a load on the water pump and prevent deterioration of fuel consumption of the internal combustion engine. Moreover, since the kinematic viscosity in 25 degreeC is 8.5 mm < ² > / sec or more, the cooling fluid composition of this invention has a kinematic viscosity higher than the conventional 80% ethylene glycol cooling fluid. The ethylene glycol coolant cannot be used as a coolant because the flash point is generated when the ethylene glycol concentration exceeds 80%.

The coolant composition of the present invention has a kinematic viscosity at 100 ° C. of 2.0 mm ² / sec or less, preferably 0.3 to 2.0 mm ² / sec, particularly preferably 0.3 to 1.5 mm ² / sec. Since it is low, the cooling capability at a high temperature is maintained, and overheating can be prevented. The cooling capacity of the cooling liquid composition can be evaluated, for example, by measuring the radiator heat transmittance. The kinematic viscosity at 100 ° C. of a 100% water coolant is 0.3 mm ² / sec.

  The coolant composition of the present invention preferably contains a base having antifreezing properties. The compounding amount of the base is preferably 86 to 99.99 parts by mass and particularly preferably 94.5 to 99.9 parts by mass with respect to 100 parts by mass of the composition.

  The base contains at least one alcohol selected from the group consisting of monohydric alcohols, dihydric alcohols, trihydric alcohols and glycol monoalkyl ethers and / or water. If antifreeze is not required, the base may be water alone.

  As monohydric alcohol, what consists of 1 type, or 2 or more types of mixtures chosen from methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol, for example can be mentioned.

  Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, and hexylene glycol. What consists of 1 type, or 2 or more types of mixtures chosen from among these can be mentioned.

  Examples of the trihydric alcohol include one or more selected from glycerin, trimethylolethane, trimethylolpropane, 5-methyl-1,2,4-heptanetriol, and 1,2,6-hexanetriol. The thing which consists of a mixture can be mentioned.

  Examples of the glycol monoalkyl ether include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol. Mention may be made of one or a mixture of two or more selected from monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether and tetraethylene glycol monobutyl ether.

  Among the above bases, ethylene glycol, propylene glycol, and 1,3-propanediol are preferable from the viewpoints of handleability, cost, and availability.

  The blending amount of the alcohols is preferably 8.9 to 98.83, particularly preferably 22.25 to 98.83 with respect to 100 parts by mass of the composition in consideration of antifreezing properties.

  As said water, ion-exchange water is preferable. 0.89-89.85 is preferable with respect to 100 mass parts of compositions, and 0.89-74.87 is especially preferable with respect to 100 mass parts of compositions.

  When the base contains water and alcohols, the mixing ratio of water and alcohols can be arbitrarily adjusted in consideration of antifreezing and flammability. The ratio of water and alcohol in the base is preferably 20:80 to 90:10, and particularly preferably 40:60 to 75:25, from the viewpoint of avoiding the flash point.

  In the cooling liquid composition of the present invention, other additives can be blended with the base as needed within the range not impairing the effects of the present invention, in addition to the viscosity property improving agent.

  For example, the cooling composition of the present invention includes at least one or more rust preventives in a range that does not affect kinematic viscosity in order to effectively suppress corrosion of the metal used in the engine coolant path. Can be made. Antirust agents include aliphatic carboxylic acids and / or salts thereof, phosphoric acid and / or salts thereof, aromatic carboxylic acids and / or salts thereof, triazoles, thiazoles, silicates, nitrates, nitrites, boron Any one or a mixture of two or more of acid salts, molybdates and amine salts can be mentioned.

  In addition, for example, a pH adjusting agent such as sodium hydroxide or potassium hydroxide, an antifoaming agent, a colorant, a dye, or a dispersing agent is appropriately added to the cooling composition of the present invention as long as it does not affect kinematic viscosity. be able to.

  The total amount of the other additives is usually 10 parts by mass or less, preferably 5 parts by mass or less, with respect to 100 parts by mass of the composition.

  The coolant composition of the present invention can be used as a coolant for an internal combustion engine.

The present invention also relates to a concentrated composition for obtaining the coolant composition. The concentrated composition of the present invention is a composition comprising the above-mentioned viscosity property improving agent and the above-mentioned base. The cooling liquid composition of the present invention can be obtained by adding the remaining base and optionally other additives to the concentrated composition of the present invention. The base contained in the concentrated composition of the present invention may be the same as or different from the base further added to obtain the coolant composition. The concentrated composition of the present invention preferably contains 0.1 to 99.9 parts by mass of the above-mentioned viscosity characteristic improving agent with respect to 100 parts by mass of the concentrated composition, and the above-mentioned base with respect to 100 parts by mass of the concentrated composition. It is preferable to contain 1-99.9 mass parts.
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to the range of an Example.

[Example 1]
47.93 parts by mass of ethylene glycol and 50 parts by mass of ion-exchanged water were mixed, and 2 parts by mass of disodium sebacate as a rust inhibitor was added and mixed. After adding 0.07 part by mass of hydroxyethyl cellulose (molecular weight: 1,560,000) as a viscosity property improver to the obtained mixture, the mixture was heated to 80 ° C., then stirred for 60 minutes, stirred and cooled. A coolant composition was obtained.

[Example 2]
The coolant was used in the same manner as in Example 1 except that ethylene glycol, ion-exchanged water, and a rust inhibitor were used in the amounts shown in Table 1, and 1 part by mass of hydroxyethyl cellulose (molecular weight: 50,000) was used as a viscosity property improver. A composition was obtained.

[Example 3]
Example 1 was used except that ethylene glycol, ion-exchanged water and a rust inhibitor were used in the amounts shown in Table 1, and 0.1 part by mass of a carboxymethyl cellulose salt (molecular weight 1,500,000) was used as a viscosity characteristic improver. As a result, a coolant composition was obtained.

[Example 4]
Example 1 was used except that ethylene glycol, ion-exchanged water and a rust inhibitor were used in the amounts shown in Table 1, and 0.6 parts by mass of a carboxymethyl cellulose salt (molecular weight 250,000) was used as a viscosity characteristic improver. As a result, a coolant composition was obtained.

[Example 5]
Example 1 was used except that ethylene glycol, ion-exchanged water, and a rust inhibitor were used in the amounts shown in Table 1, and 0.1 parts by mass of cationized cellulose (molecular weight 1,500,000) was used as a viscosity property improver. As a result, a coolant composition was obtained.

[Example 6]
Example 1 was used except that ethylene glycol, ion-exchanged water and a rust inhibitor were used in the amounts shown in Table 1, and 0.5 parts by mass of cationized cellulose (molecular weight: 600,000) was used as a viscosity property improver. As a result, a coolant composition was obtained.

[Comparative Example 1]
A coolant composition in the same manner as in Example 1 except that ethylene glycol, ion-exchanged water and an antirust agent were used in the amounts shown in Table 1, and 0.1 parts by mass of ethyl cellulose was used in place of the viscosity property improver. Got.

[Comparative Example 2]
The coolant was used in the same manner as in Example 1 except that ethylene glycol, ion-exchanged water, and a rust inhibitor were used in the amounts shown in Table 1, and 0.1 parts by mass of ethyl hydroxyethyl cellulose was used instead of the viscosity property improver. A composition was obtained.

[Comparative Example 3]
The coolant was used in the same manner as in Example 1 except that ethylene glycol, ion-exchanged water and an antirust agent were used in the amounts shown in Table 1, and 0.1 part by mass of carboxymethylethylcellulose was used instead of the viscosity property improver. A composition was obtained.

[Comparative Example 4]
The coolant was used in the same manner as in Example 1 except that ethylene glycol, ion-exchanged water, and a rust inhibitor were used in the amounts shown in Table 1, and 0.1 part by mass of hydroxypropylmethylcellulose was used instead of the viscosity property improver. A composition was obtained.

[Comparative Example 5]
A coolant composition in the same manner as in Example 1 except that ethylene glycol, ion-exchanged water and an antirust agent were used in the amounts shown in Table 1, and 0.1 parts by mass of methylcellulose was used in place of the viscosity property improver. Got.

[Comparative Example 6]
Coolant as in Example 1 except that ethylene glycol, ion-exchanged water, and a rust inhibitor are used in the amounts shown in Table 1, and 0.1 part by mass of hydroxypropylcellulose is used in place of the viscosity property improver. A composition was obtained.

[Comparative Example 7]
The coolant was used in the same manner as in Example 1 except that ethylene glycol, ion-exchanged water and an antirust agent were used in the amounts shown in Table 1, and 0.2 parts by mass of carboxyvinyl polymer was used instead of the viscosity property improver. A composition was obtained.

[Comparative Example 8]
A coolant composition was obtained in the same manner as in Example 1 except that ethylene glycol, ion-exchanged water, and a rust inhibitor were used in the amounts shown in Table 1, and no viscosity property improver was used. The coolant composition of Comparative Example 8 was used as a reference for warm-up performance and cooling performance.

[Comparative Example 9]
A coolant composition was obtained in the same manner as in Example 1 except that ion-exchanged water and an antirust agent were used in the amounts shown in Table 1 and ethylene glycol and a viscosity property improver were not used.

[Comparative Example 10]
Example 1 was used except that ethylene glycol, ion-exchanged water, and a rust inhibitor were used in the amounts shown in Table 1, and 0.005 parts by mass of hydroxyethyl cellulose (molecular weight: 1,560,000) as a viscosity property improver was used. Thus, a coolant composition was obtained.

[Comparative Example 11]
Example 1 was used except that ethylene glycol, ion-exchanged water, and a rust inhibitor were used in the amounts shown in Table 1, and 1.4 parts by mass of hydroxyethyl cellulose (molecular weight: 50,000) was used as a viscosity property improver. A coolant composition was obtained.

  The kinematic viscosities at 25 ° C. and 100 ° C. of the coolant compositions obtained in Example 1-6 and Comparative Example 1-11 were measured, and the thermal characteristics (warming-up performance and cooling performance) were evaluated.

<Measurement of kinematic viscosity>
The kinematic viscosity at 25 ° C. and 100 ° C. of the coolant composition is JIS K 2283 or ASTM D445. The measurement was performed according to a test method using a D446 glass capillary viscometer. Specifically, it measured by the following method.
(1) A Ubbelohde viscometer defined in JIS K 2283 was prepared, and a specified amount of the sample was filled while being tilted so that bubbles did not enter.
(2) The viscometer filled with the sample was conditioned in a constant temperature water bath for 15 minutes.
(3) The sample was sucked up to the upper time mark and then naturally dropped, and the time for the meniscus to pass from the upper part to the lower part of the time mark was measured.
(4) When the measurement time was less than 200 seconds, the viscometer was replaced and the operations (1) to (3) were performed.
(5) When the measurement is performed twice using a viscometer with a measurement time of 200 seconds or more, and the difference in the measurement time is within 0.2% of the average value, the average measurement time and the viscometer used The kinematic viscosity was calculated from the viscometer constant.

<Warm-up performance>
The warm-up performance was measured by using a simple thermal property evaluation test apparatus (see FIG. 1) at room temperature of 25 ° C., and measuring the time until the aluminum casting was heated from 25 ° C. to 60 ° C. The result of Comparative Example 8 (240 seconds) was set to a reference value of 1.0.

<Cooling performance>
The warm-up performance was measured using a simple thermal property evaluation test apparatus (see FIG. 1) at room temperature of 25 ° C., and the time until the aluminum casting was cooled from 90 ° C. to 80 ° C. was measured. The result of Comparative Example 8 (300 seconds) was taken as the reference value 1.0.

  Table 1 shows the measurement results of the kinematic viscosity, warm-up performance, and cooling performance of the coolant compositions obtained in Example 1-6 and Comparative Example 1-11. The solubility in Table 1 other than Comparative Examples 5 and 6 shows the results at 25 ° C.

  From Table 1, the coolant composition of Example 1-6 has a high kinematic viscosity at low temperatures and a sufficient decrease in kinematic viscosity at high temperatures. It can be seen that the warm-up performance is further improved and the cooling performance is maintained.

  It can be seen that Comparative Example 10 does not have an effect as a viscosity property improver because the content of the viscosity property improver is not sufficient.

  In Comparative Example 11, the content of the viscosity property improver is large, so the kinematic viscosity at low temperature is high and the warm-up performance is improved, but the decrease in kinematic viscosity at high temperature is small and the cooling performance is inferior. .

  The coolant composition of the present invention is suitable for cooling vehicles, vehicles such as automobiles, working vehicles (trucks, heavy machinery, etc.), ships, aircraft, generators, internal combustion engines (including hybrid systems) of air conditioning systems (including hybrid systems), batteries, and inverters. Used for.

Claims (5)

Containing a cellulose derivative as a viscosity property improver, and a base,
The cellulose derivative is water soluble and does not thermally gel at 100 ° C.
The base contains at least one alcohol selected from the group consisting of monohydric alcohols, dihydric alcohols, trihydric alcohols and glycol monoalkyl ethers and / or water;
The monohydric alcohol is one or a mixture of two or more selected from the group consisting of butanol, pentanol, hexanol, heptanol and octanol,
Kinematic viscosity, except 25 ° C. in it at 8.5 mm ² / sec or more and 2.0 mm ² / sec or less is coolant composition at 100 ° C. (provided that coolant compositions containing mosquitoes over carbon nanotubes ). Cellulose derivatives are:
Formula (1):

[Wherein R ₁ , R ₂ and R ₃ are independently selected from — (CH ₂ CH ₂ O) _n —H and a hydrogen atom, wherein n is an integer of 1 to 3, provided that R ₁ , R ₂ and R ₃ are not all hydrogen atoms. ]
Hydroxyethyl cellulose comprising repeating units represented by:
Formula (1) [wherein, R ₁ and R ₂ are hydrogen atoms, and R ₃ is —CH ₂ COOX, wherein X is sodium or potassium. And a carboxymethyl cellulose salt comprising a repeating unit represented by formula (1): wherein R ₁ and R ₂ are a hydrogen atom, and R ₃ is a formula (2):

Or a group represented by formula (3):

Where n is an integer of 1 to 3. At least one selected from cationic celluloses consisting of repeating units represented by
The coolant composition according to claim 1 , wherein the molecular weight is 50,000 to 1.6 million. The coolant composition according to claim 1 or 2 , wherein the molecular weight of the cellulose derivative is 500,000 to 1,560,000. The coolant composition according to any one of claims 1 to 3 , comprising 0.05 to 1.2 parts by mass of the cellulose derivative with respect to 100 parts by mass of the composition. The operating method of an internal combustion engine using the cooling fluid composition of any one of Claims 1-4 as a cooling fluid of an internal combustion engine.

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